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Sample records for hummingbird quadrotor uav

  1. Geometric Tracking Control of a Quadrotor UAV on SE(3)

    CERN Document Server

    Lee, Taeyoung; McClamroch, N Harris

    2010-01-01

    This paper provides new results for the tracking control of a quadrotor unmanned aerial vehicle (UAV). The UAV has four input degrees of freedom, namely the magnitudes of the four rotor thrusts, that are used to control the six translational and rotational degrees of freedom, and to achieve asymptotic tracking of four outputs, namely, three position variables for the vehicle center of mass and the direction of one vehicle body-fixed axis. A globally defined model of the quadrotor UAV rigid body dynamics is introduced as a basis for the analysis. A nonlinear tracking controller is developed on the special Euclidean group SE(3) and it is shown to have desirable closed loop properties that are almost global. Several numerical examples, including an example in which the quadrotor recovers from being initially upside down, illustrate the versatility of the controller.

  2. Autonomous Control of a Quadrotor UAV Using Fuzzy Logic

    Science.gov (United States)

    Sureshkumar, Vijaykumar

    UAVs are being increasingly used today than ever before in both military and civil applications. They are heavily preferred in "dull, dirty or dangerous" mission scenarios. Increasingly, UAVs of all kinds are being used in policing, fire-fighting, inspection of structures, pipelines etc. Recently, the FAA gave its permission for UAVs to be used on film sets for motion capture and high definition video recording. The rapid development in MEMS and actuator technology has made possible a plethora of UAVs that are suited for commercial applications in an increasingly cost effective manner. An emerging popular rotary wing UAV platform is the Quadrotor A Quadrotor is a helicopter with four rotors, that make it more stable; but more complex to model and control. Characteristics that provide a clear advantage over other fixed wing UAVs are VTOL and hovering capabilities as well as a greater maneuverability. It is also simple in construction and design compared to a scaled single rotorcraft. Flying such UAVs using a traditional radio Transmitter-Receiver setup can be a daunting task especially in high stress situations. In order to make such platforms widely applicable, a certain level of autonomy is imperative to the future of such UAVs. This thesis paper presents a methodology for the autonomous control of a Quadrotor UAV using Fuzzy Logic. Fuzzy logic control has been chosen over conventional control methods as it can deal effectively with highly nonlinear systems, allows for imprecise data and is extremely modular. Modularity and adaptability are the key cornerstones of FLC. The objective of this thesis is to present the steps of designing, building and simulating an intelligent flight control module for a Quadrotor UAV. In the course of this research effort, a Quadrotor UAV is indigenously developed utilizing the resources of an online open source project called Aeroquad. System design is comprehensively dealt with. A math model for the Quadrotor is developed and a

  3. Output feedback control of a quadrotor UAV using neural networks.

    Science.gov (United States)

    Dierks, Travis; Jagannathan, Sarangapani

    2010-01-01

    In this paper, a new nonlinear controller for a quadrotor unmanned aerial vehicle (UAV) is proposed using neural networks (NNs) and output feedback. The assumption on the availability of UAV dynamics is not always practical, especially in an outdoor environment. Therefore, in this work, an NN is introduced to learn the complete dynamics of the UAV online, including uncertain nonlinear terms like aerodynamic friction and blade flapping. Although a quadrotor UAV is underactuated, a novel NN virtual control input scheme is proposed which allows all six degrees of freedom (DOF) of the UAV to be controlled using only four control inputs. Furthermore, an NN observer is introduced to estimate the translational and angular velocities of the UAV, and an output feedback control law is developed in which only the position and the attitude of the UAV are considered measurable. It is shown using Lyapunov theory that the position, orientation, and velocity tracking errors, the virtual control and observer estimation errors, and the NN weight estimation errors for each NN are all semiglobally uniformly ultimately bounded (SGUUB) in the presence of bounded disturbances and NN functional reconstruction errors while simultaneously relaxing the separation principle. The effectiveness of proposed output feedback control scheme is then demonstrated in the presence of unknown nonlinear dynamics and disturbances, and simulation results are included to demonstrate the theoretical conjecture.

  4. Visual Servoing for a Quadrotor UAV in Target Tracking Applications

    Science.gov (United States)

    Popova, Marinela Georgieva

    This research study investigates the design and implementation of position-based and image-based visual servoing techniques for controlling the motion of quadrotor unmanned aerial vehicles (UAVs). The primary applications considered are tracking stationary and moving targets. A novel position-based tracking law is developed and integrated with inner loop proportional-integral-derivative control algorithm. A theoretical proof for the stability of the proposed method is provided and numerical simulations are performed to validate the performance of the closed-loop system. A classical image-based visual servoing technique is also implemented and a modification of the classical method is suggested to reduce the undesirable effects due to the underactuated quadrotor system. Finally, the case when the quadrotor loses sight of the target is investigated and several solutions are proposed to help maintain the view of the target.

  5. Robust guaranteed cost tracking control of quadrotor UAV with uncertainties.

    Science.gov (United States)

    Xu, Zhiwei; Nian, Xiaohong; Wang, Haibo; Chen, Yinsheng

    2017-07-01

    In this paper, a robust guaranteed cost controller (RGCC) is proposed for quadrotor UAV system with uncertainties to address set-point tracking problem. A sufficient condition of the existence for RGCC is derived by Lyapunov stability theorem. The designed RGCC not only guarantees the whole closed-loop system asymptotically stable but also makes the quadratic performance level built for the closed-loop system have an upper bound irrespective to all admissible parameter uncertainties. Then, an optimal robust guaranteed cost controller is developed to minimize the upper bound of performance level. Simulation results verify the presented control algorithms possess small overshoot and short setting time, with which the quadrotor has ability to perform set-point tracking task well. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  6. Second order sliding mode control for a quadrotor UAV.

    Science.gov (United States)

    Zheng, En-Hui; Xiong, Jing-Jing; Luo, Ji-Liang

    2014-07-01

    A method based on second order sliding mode control (2-SMC) is proposed to design controllers for a small quadrotor UAV. For the switching sliding manifold design, the selection of the coefficients of the switching sliding manifold is in general a sophisticated issue because the coefficients are nonlinear. In this work, in order to perform the position and attitude tracking control of the quadrotor perfectly, the dynamical model of the quadrotor is divided into two subsystems, i.e., a fully actuated subsystem and an underactuated subsystem. For the former, a sliding manifold is defined by combining the position and velocity tracking errors of one state variable, i.e., the sliding manifold has two coefficients. For the latter, a sliding manifold is constructed via a linear combination of position and velocity tracking errors of two state variables, i.e., the sliding manifold has four coefficients. In order to further obtain the nonlinear coefficients of the sliding manifold, Hurwitz stability analysis is used to the solving process. In addition, the flight controllers are derived by using Lyapunov theory, which guarantees that all system state trajectories reach and stay on the sliding surfaces. Extensive simulation results are given to illustrate the effectiveness of the proposed control method.

  7. Position and attitude tracking control for a quadrotor UAV.

    Science.gov (United States)

    Xiong, Jing-Jing; Zheng, En-Hui

    2014-05-01

    A synthesis control method is proposed to perform the position and attitude tracking control of the dynamical model of a small quadrotor unmanned aerial vehicle (UAV), where the dynamical model is underactuated, highly-coupled and nonlinear. Firstly, the dynamical model is divided into a fully actuated subsystem and an underactuated subsystem. Secondly, a controller of the fully actuated subsystem is designed through a novel robust terminal sliding mode control (TSMC) algorithm, which is utilized to guarantee all state variables converge to their desired values in short time, the convergence time is so small that the state variables are acted as time invariants in the underactuated subsystem, and, a controller of the underactuated subsystem is designed via sliding mode control (SMC), in addition, the stabilities of the subsystems are demonstrated by Lyapunov theory, respectively. Lastly, in order to demonstrate the robustness of the proposed control method, the aerodynamic forces and moments and air drag taken as external disturbances are taken into account, the obtained simulation results show that the synthesis control method has good performance in terms of position and attitude tracking when faced with external disturbances.

  8. Nonlinear Robust Tracking Control of a Quadrotor UAV on SE(3)

    CERN Document Server

    Lee, Taeyoung; McClamroch, N Harris

    2011-01-01

    This paper provides nonlinear tracking control systems for a quadrotor unmanned aerial vehicle (UAV) that are robust to bounded uncertainties. A mathematical model of a quadrotor UAV is defined on the special Euclidean group, and nonlinear output-tracking controllers are developed to follow (1) an attitude command, and (2) a position command for the vehicle center of mass. The controlled system has the desirable properties that the tracking errors are uniformly ultimately bounded, and the size of the ultimate bound can be arbitrarily reduced by control system parameters. Numerical examples illustrating complex maneuvers are provided.

  9. Colour-based Object Detection and Tracking for Autonomous Quadrotor UAV

    Science.gov (United States)

    Kadouf, Hani Hunud A.; Mohd Mustafah, Yasir

    2013-12-01

    With robotics becoming a fundamental aspect of modern society, further research and consequent application is ever increasing. Aerial robotics, in particular, covers applications such as surveillance in hostile military zones or search and rescue operations in disaster stricken areas, where ground navigation is impossible. The increased visual capacity of UAV's (Unmanned Air Vehicles) is also applicable in the support of ground vehicles to provide supplies for emergency assistance, for scouting purposes or to extend communication beyond insurmountable land or water barriers. The Quadrotor, which is a small UAV has its lift generated by four rotors and can be controlled by altering the speeds of its motors relative to each other. The four rotors allow for a higher payload than single or dual rotor UAVs, which makes it safer and more suitable to carry camera and transmitter equipment. An onboard camera is used to capture and transmit images of the Quadrotor's First Person View (FPV) while in flight, in real time, wirelessly to a base station. The aim of this research is to develop an autonomous quadrotor platform capable of transmitting real time video signals to a base station for processing. The result from the image analysis will be used as a feedback in the quadrotor positioning control. To validate the system, the algorithm should have the capacity to make the quadrotor identify, track or hover above stationary or moving objects.

  10. Coordination and Control for Multi-Quadrotor UAV Missions

    Science.gov (United States)

    2012-03-01

    Disadvantages .......................4 C. RELATED WORK .......................................4 1. General .......................................4 2...force, reducing the potential for damage to occur in the event of a collision. 2. Quadrotor Disadvantages Although quadrotors have many advantages...by Parrot, a company better known for electronics such as car stereos. Parrot’s AR.Drone uses a Wi-Fi signal that links to an iphone, iPod Touch

  11. Global fast dynamic terminal sliding mode control for a quadrotor UAV.

    Science.gov (United States)

    Xiong, Jing-Jing; Zhang, Guo-Bao

    2017-01-01

    A control method based on global fast dynamic terminal sliding mode control (TSMC) technique is proposed to design the flight controller for performing the finite-time position and attitude tracking control of a small quadrotor UAV. Firstly, the dynamic model of the quadrotor is divided into two subsystems, i.e., a fully actuated subsystem and an underactuated subsystem. Secondly, the dynamic flight controllers of the quadrotor are formulated based on global fast dynamic TSMC, which is able to guarantee that the position and velocity tracking errors of all system state variables converge to zero in finite-time. Moreover, the global fast dynamic TSMC is also able to eliminate the chattering phenomenon caused by the switching control action and realize the high precision performance. In addition, the stabilities of two subsystems are demonstrated by Lyapunov theory, respectively. Lastly, the simulation results are given to illustrate the effectiveness and robustness of the proposed control method in the presence of external disturbances.

  12. Systematic Fault Tolerant Control Based on Adaptive Thau Observer Estimation for Quadrotor Uavs

    Directory of Open Access Journals (Sweden)

    Cen Zhaohui

    2015-03-01

    Full Text Available A systematic fault tolerant control (FTC scheme based on fault estimation for a quadrotor actuator, which integrates normal control, active and passive FTC and fault parking is proposed in this paper. Firstly, an adaptive Thau observer (ATO is presented to estimate the quadrotor rotor fault magnitudes, and then faults with different magnitudes and time-varying natures are rated into corresponding fault severity levels based on the pre-defined fault-tolerant boundaries. Secondly, a systematic FTC strategy which can coordinate various FTC methods is designed to compensate for failures depending on the fault types and severity levels. Unlike former stand-alone passive FTC or active FTC, our proposed FTC scheme can compensate for faults in a way of condition-based maintenance (CBM, and especially consider the fatal failures that traditional FTC techniques cannot accommodate to avoid the crashing of UAVs. Finally, various simulations are carried out to show the performance and effectiveness of the proposed method.

  13. Path Planning Using Concatenated Analytically-Defined Trajectories for Quadrotor UAVs

    Directory of Open Access Journals (Sweden)

    Jonathan Jamieson

    2015-04-01

    Full Text Available This paper presents a semi-analytical trajectory planning method for quadrotor UAVs. These trajectories are analytically defined, are constant in speed and sub-optimal with respect to a weighted quadratic cost function of the translational and angular velocities. A technique for concatenating the trajectories into multi-segment paths is demonstrated. These paths are smooth to the first derivative of the translational position and pass through defined waypoints. A method for detecting potential collisions by discretizing the path into a coarse mesh before using a numerical optimiser to determine the point of the path closest to the obstacle is presented. This hybrid method reduces the computation time when compared to discretizing the trajectory into a fine mesh and calculating the minimum distance. A tracking controller is defined and used to show that the paths are dynamically feasible and the typical magnitudes of the controller inputs required to fly them.

  14. Attitude Stabilization Control of a Quadrotor UAV by Using Backstepping Approach

    Directory of Open Access Journals (Sweden)

    Xing Huo

    2014-01-01

    Full Text Available The modeling and attitude stabilization control problems of a four-rotor vertical takeoff and landing unmanned air vehicle (UAV known as the quadrotor are investigated. The quadrotor’s attitude is represented by the unit quaternion rather than Euler angles to avoid singularity problem. Taking dynamical behavior of motors into consideration and ignoring aerodynamic effect, a nonlinear controller is developed to stabilize the attitude. The control design is accomplished by using backstepping control technique. The proposed control law is based on the compensation for the Coriolis and gyroscope torques. Applying Lyapunov stability analysis proves that the closed-loop attitude system is asymptotic stable. Moreover, the controller can guarantee that all the states of the system are uniformly ultimately bounded in the presence of external disturbance torque. The effectiveness of the proposed control approach is analytically authenticated and also validated via simulation study.

  15. Assembly of an Experimental Quad-Rotor Type UAV for Testing a Novel Autonomous Flight Control Strategy

    Directory of Open Access Journals (Sweden)

    Shahida Khatoon

    2013-12-01

    Full Text Available In this research a prototype experimental Quad-rotor type UAV have been assembled using low cost components easily available in the Indian market. The quad-copter is used for testing a novel autonomous flight control strategy developed using embedded system. In order to enable a mini-UAV to perform target acquisition, localization and continuous surveillance in real world environment one must develop a technology which may be a combination of aircraft engineering, control systems, and wireless communication. The major limiting factors in developing the capabilities of small low cost UAVs are connectivity, computational processing power and lack of resource integration. To overcome these limitations in this research we have tried to assemble an experimental quad-rotor prototype UAV capable of being remotely controlled in the range of 20 meter, which is specifically designed as an economical, moderately functional, small airborne platform intended to meet the requirement for fast-response to time-critical events in many small private sectors or government agencies. The experimental prototype quad-copter has been successfully implemented and tested for 15 minutes smooth flight time.

  16. Robust Adaptive Geometric Tracking Controls on SO(3) with an Application to the Attitude Dynamics of a Quadrotor UAV

    CERN Document Server

    Lee, Taeyoung

    2011-01-01

    This paper provides new results for a robust adaptive tracking control of the attitude dynamics of a rigid body. Both of the attitude dynamics and the proposed control system are globally expressed on the special orthogonal group, to avoid complexities and ambiguities associated with other attitude representations such as Euler angles or quaternions. By designing an adaptive law for the inertia matrix of a rigid body, the proposed control system can asymptotically follow an attitude command without the knowledge of the inertia matrix, and it is extended to guarantee boundedness of tracking errors in the presence of unstructured disturbances. These are illustrated by numerical examples and experiments for the attitude dynamics of a quadrotor UAV.

  17. Optimal Stabilization of A Quadrotor UAV by a Constrained Fuzzy Control and PSO

    Directory of Open Access Journals (Sweden)

    Boubertakh Hamid

    2017-01-01

    Full Text Available This work aims to design an optimal fuzzy PD (FPD control for the attitude and altitude stabilization of a quadrotor. The control design is done by mean of the particle swarm optimization (PSO under the constraints of the controller interpretability and the saturation of the actuators. Concretely, a decentralized control structure is adopted where four FPD controllers are used to stabilize the quadrotor angles (roll, pitch and yaw and height. A PSO-based algorithm is used to simultaneously tune the four constrained controllers regarding a cost function quantifying the whole system performances. The simulation results are presented to show the efficiency of the proposed approach.

  18. 四旋翼无人机的多模型故障诊断%Multiple model fault diagnosis method for quadrotor UAV

    Institute of Scientific and Technical Information of China (English)

    徐雪松

    2016-01-01

    Quadrotor Unmanned Air Vehicle(UAV)is a close-coupled and strong nonlinear object. It is very important to find out faults precisely and regulate the controller quickly for maintaining safety of the quadrotor UAV. In this paper, an online fault diagnosis method based on multiple model algorithm is presented for actuator fault detection of the quadrotor UAV. In this method, a fault model set is built according to different fault modes. The operating mode is online monitored by parallel operation of the model set. Simulation results show with this method the parameters of fault model can be esti-mated quickly and precisely for partial loss of effectiveness faults of singular actuator.%四旋翼无人机是一个强耦合非线性被控对象,准确地判断故障情况,并及时调整控制器参数对无人机的安全飞行具有重要的意义。针对四旋翼无人机的执行器部分失效故障,提出了一种多模型在线故障诊断方法。该方法根据不同故障模式建立故障模型集,通过模型集的并联运行对无人机工作模式进行在线监测。仿真结果表明,对于单旋翼执行器部分失效故障,该方法能够快速准确地获得故障模型参数。

  19. Long Term Quadrotor Stabilization

    Science.gov (United States)

    2011-03-01

    solutions since they offer greater mobility in these environments than fixed wing UAVs or unmanned ground vehicles. Quadrotors were selected over more...Technology ANT Advanced Navigation Techonology BEC Battery Eliminator Circuit DCM Direction Cosine Matrix ESC Electronic Speed Controller FPGA Field...degree of mobility . As a result, hovering unmanned air vehicles (UAVs) have been selected as the vehicles of choice in these environments. It is also

  20. Trajectory optimization of multiple quad-rotor UAVs in collaborative assembling task

    Directory of Open Access Journals (Sweden)

    Chen Yongbo

    2016-02-01

    Full Text Available A hierarchic optimization strategy based on the offline path planning process and online trajectory planning process is presented to solve the trajectory optimization problem of multiple quad-rotor unmanned aerial vehicles in the collaborative assembling task. Firstly, the path planning process is solved by a novel parallel intelligent optimization algorithm, the central force optimization-genetic algorithm (CFO-GA, which combines the central force optimization (CFO algorithm with the genetic algorithm (GA. Because of the immaturity of the CFO, the convergence analysis of the CFO is completed by the stability theory of the linear time-variant discrete-time systems. The results show that the parallel CFO-GA algorithm converges faster than the parallel CFO and the central force optimization-sequential quadratic programming (CFO-SQP algorithm. Then, the trajectory planning problem is established based on the path planning results. In order to limit the range of the attitude angle and guarantee the flight stability, the optimized object is changed from the ordinary six-degree-of-freedom rigid-body dynamic model to the dynamic model with an inner-loop attitude controller. The results show that the trajectory planning process can be solved by the mature SQP algorithm easily. Finally, the discussion and analysis of the real-time performance of the hierarchic optimization strategy are presented around the group number of the waypoints and the equal interval time.

  1. Trajectory optimization of multiple quad-rotor UAVs in collaborative assembling task

    Institute of Scientific and Technical Information of China (English)

    Chen Yongbo; Yu Jianqiao; Mei Yuesong; Zhang Siyu; Ai Xiaolin; Jia Zhenyue

    2016-01-01

    A hierarchic optimization strategy based on the offline path planning process and online trajectory planning process is presented to solve the trajectory optimization problem of multiple quad-rotor unmanned aerial vehicles in the collaborative assembling task. Firstly, the path planning process is solved by a novel parallel intelligent optimization algorithm, the central force optimization-genetic algorithm (CFO-GA), which combines the central force optimization (CFO) algorithm with the genetic algorithm (GA). Because of the immaturity of the CFO, the convergence analysis of the CFO is completed by the stability theory of the linear time-variant discrete-time sys-tems. The results show that the parallel CFO-GA algorithm converges faster than the parallel CFO and the central force optimization-sequential quadratic programming (CFO-SQP) algorithm. Then, the trajectory planning problem is established based on the path planning results. In order to limit the range of the attitude angle and guarantee the flight stability, the optimized object is changed from the ordinary six-degree-of-freedom rigid-body dynamic model to the dynamic model with an inner-loop attitude controller. The results show that the trajectory planning process can be solved by the mature SQP algorithm easily. Finally, the discussion and analysis of the real-time per-formance of the hierarchic optimization strategy are presented around the group number of the waypoints and the equal interval time.

  2. Consensus Based Distributed Formation Control of Quadrotor UAVs%基于一致性理论的四旋翼无人机分布式编队控制方法

    Institute of Scientific and Technical Information of China (English)

    李磊; 李小民; 郑忠贵; 张国荣

    2015-01-01

    A distributed control method for formation of quadrotor UAVs is presented with introductions on the fundamental knowledge of graph theory and consensus of swarm system. The quadrotor UAV is described as a second-order integrator dynamic system, and the relative position is used to describe the UAV formation shape. The quadrotor UAV formation is modeled based on the communication topology relationship of quadrotors. The strategy of follower-leader method integrated with graph-based method is explored. A second-order consensus algorithm is presented, with which the fleet can complete formation gathering and formation maneuvering. Finally, the effectiveness of this algorithm is shown through the simulation results.%介绍了图论和群体系统一致性的相关理论,提出一种分布式四旋翼无人机编队控制方法,将四旋翼无人机描述为二阶积分器动力系统,采用相对位置偏差描述编队队形;根据四旋翼无人机之间通信拓扑关系将四旋翼无人机编队建模为图,探索了领航跟随法和基于图论法的融合策略,给出一种有领航者的二阶一致性算法。在该算法下,编队可以完成编队集结和编队机动等行为,最后通过仿真实验验证了该方法的有效性。

  3. 基于手势识别的四旋翼控制系统%The Quadrotor UAV ContorI System Based on Gesture Recognition

    Institute of Scientific and Technical Information of China (English)

    李辉; 芦利斌; 金国栋

    2015-01-01

    针对传统无人机(UAV)控制系统复杂度高、专业性强的问题,提出一种手势动作控制无人机的系统。利用Kinect传感器获取用户骨骼节点数据,通过一个人机交互界面(HCI),识别用户的手势动作并生成相应的四旋翼飞行控制指令,进而实现对四旋翼无人机的飞行控制。设计完整的手势控制系统和相关的手势识别及控制算法,实验结果表明提出的方法简单直观、效果良好。%Aiming at the problems of complicated operation and high professional in traditional UAV remote control system, proposes a gesture-based control system. The location data of the operator's body postures are collected by Kinect sensor. Through a Human Machine Inter-face, the operator's gestures are recognized and then converted into control commands for quadrotor UAV, which realizes the flight con-trol. Designs a completed gesture control system, the associated gesture recognition and control algorithm. Experimental result shows that the proposed method is intuitive, simple and effective.

  4. Electromagnetic Environment Monitor and Analysis System Based on Quad-rotor UAV Platform%基于四旋翼无人机的电磁环境监测分析系统

    Institute of Scientific and Technical Information of China (English)

    贾语扬; 张凯; 卢小祝; 尚晓凡; 苏东林

    2016-01-01

    提出一套基于四旋翼无人机平台的电磁环境监测分析系统,通过将电磁环境监测硬件集成到四旋翼无人机平台上,使用自行开发的测量管理软件和电磁干扰源定位算法,可以实现对空间电磁环境的自动测量及测量数据实时分析处理.详细介绍测量管理软件的组成和基于电磁干扰源定位算法开发的电磁环境可视化软件.实验结果表明,基于四旋翼无人机平台的电磁环境监测分析系统自动化程度高,测量精度高,且显示直观.%An electromagnetic environment (EME) monitor and analysis system based on quad-rotor UAV platform is proposed. By integrating the EME monitoring hardware into quad-rotor UAV platform and utilizing self-developed measurement management software and electromagnetic interference source localization algorithm, the automatic measurement of space electromagnetic environment and real-time analysis of measurement data can be realized. The composition of measurement management software and the EME visualization software developed on the basis of electromagnetic interference source localization algorithm are introduced in detail. The experiment results show that this electromagnetic environment monitor and analysis system based on quad-rotor UAV platform has high degree of automation, high accuracy of measurement and visual display.

  5. Automatic Registration of Quad-Rotor UAV Imagery based on SIFT and TPS Algorithm%基于SIFT和TPS算法的四旋翼无人机图像自动配准

    Institute of Scientific and Technical Information of China (English)

    陈本清; 杨燕明; 郑凌虹; 文洪涛

    2013-01-01

    As an important complementarity of remote sensing technique,Unmanned Aerial Vehicle (UAV) is attractive to various applications such as target searching,island management,disaster monitoring and low-altitude photogrammetry.The quad-rotor UAV,Compared to fixed-wing UAV,has the advantages of Vertical-Taking-of-Landing (VTOL) and low-altitude flexible flight.However,the quad-rotor UAV has small-volume and lightweight and is more easily influenced by the wind,the acquired imagery maybe have bigger tile angle and more obvious geometry distortion will would result in more difficulty on the image feature matching and image mosaic.For this question,we apply the Scale Invariant Feature Transformation (SIFT) to image feature matching and Thin Plate Spline (TPS) transformation to automatic registration of the micro quad-rotor UAV imageries in this paper.The registration imagery based on TPS transformation is then compared to that based on the affine transformation and the polynomial transformation by evaluating the visual effect of the mosaic imagery and Root Mean Square (RMS) statistic,which shows that after precise SIFT feature matching,the registration RMS accuracy and the visual effect of mosaic imagery of TPS transformation are best,and satisfies the demand of rapid registration and mosaic of micro quad-rotor UVA imagery,since TPS transformation considered both rigid transformation and partial nonlinear distortion of the micro quad-rotor UAV imagery.%针对四旋翼无人机图像姿态倾角大、图像变形明显等特点,采用尺度不变特征变换(SIFT)算法和薄板样条模型(TPS)对四旋翼无人机图像进行特征点匹配和配准实验研究,从拼接图像的目视效果和配准均方差方面比较分析了TPS模型与常用的仿射变换及多项式变换模型的图像配准效果.结果表明:在SIFT算法精确的同名点匹配下,TPS变换模型能够兼顾四旋翼无人机图像的整体刚性变形及局部的非刚性变形,无论是目

  6. Optimization of a neural network based direct inverse control for controlling a quadrotor unmanned aerial vehicle

    Directory of Open Access Journals (Sweden)

    Heryanto M Ary

    2015-01-01

    Full Text Available UAVs are mostly used for surveillance, inspection and data acquisition. We have developed a Quadrotor UAV that is constructed based on a four motors with a lift-generating propeller at each motors. In this paper, we discuss the development of a quadrotor and its neural networks direct inverse control model using the actual flight data. To obtain a better performance of the control system of the UAV, we proposed an Optimized Direct Inverse controller based on re-training the neural networks with the new data generated from optimal maneuvers of the quadrotor. Through simulation of the quadrotor using the developed DIC and Optimized DIC model, results show that both models have the ability to stabilize the quadrotor with a good tracking performance. The optimized DIC model, however, has shown a better performance, especially in the settling time parameter.

  7. A Quadrotor Sensor Platform

    Science.gov (United States)

    2008-08-01

    17] Paul Pounds, Robert Mahoney, Joel Gresham, Peter Corke , and Jonathan Roberts. “Towards Dynamically-Favourable Quad-Rotor Aerial Robots”. In Nick...Paul Pounds, Robert Mahoney, and Peter Corke . “Modelling and Control of a Quad-Rotor Robot”. In Bruce MacDonald, editor, Proceedings of the Australasian

  8. Somatosensory control of quadrotor UAV based on Kinect%基于Kinect的四旋翼无人机体感控制

    Institute of Scientific and Technical Information of China (English)

    李辉; 芦利斌; 金国栋

    2015-01-01

    Aiming at problems of complicated operation and high professional in UAV remote control,a Kinect-based somatosensory control method is proposed and verified. The node data of the operator’s body postures are collected by Kinect sensor;body postures are designed and recognized,then are converted into control commands for UAV. The commands are sent to UAV platform by wireless data transmission module for remote control. Experimental result shows that the identification algorithm can recognize body posture accurately and control the UAV in real-time,and somatosensory control mode is intuitive,simple and effective.%针对无人机( UAV)远程控制中操作复杂、专业性高的问题,基于Kinect传感器提出了一种无人机体感控制方案,并进行了验证。利用Kinect传感器提取操作者身体的骨骼节点数据,设计并识别操作者体势动作,进而生成对应的四旋翼飞行控制指令,通过无线数传模块传输控制指令,对无人机进行远程控制。实验结果表明:设计的识别算法可以准确地识别体势动作,对无人机进行实时的控制,控制方式直观简单、效果良好。

  9. Hooked on Hummingbirds.

    Science.gov (United States)

    Bailey, Kim

    2002-01-01

    Describes several hummingbird adaptations and suggests ways of attracting hummingbirds to schoolyards and including them in the curriculum. Provides hummingbird feeder tips along with a list of ideas for designing inquiry-based activities related to hummingbird behavior. Also provides a hummingbird quiz, two instructional games, and a listing of…

  10. Visual-based quadrotor control by means of fuzzy cognitive maps.

    Science.gov (United States)

    Amirkhani, Abdollah; Shirzadeh, Masoud; Papageorgiou, Elpiniki I; Mosavi, Mohammad R

    2016-01-01

    By applying an image-based visual servoing (IBVS) method, the intelligent image-based controlling of a quadrotor type unmanned aerial vehicle (UAV) tracking a moving target is studied in this paper. A fuzzy cognitive map (FCM) is a soft computing method which is classified as a fuzzy neural system and exploits the main aspects of fuzzy logic and neural network systems; so it seems to be a suitable choice for implementing a vision-based intelligent technique. An FCM has been employed in implementing an IBVS scheme on a quadrotor UAV, so that the UAV can track a moving target on the ground. For this purpose, by properly combining the perspective image moments, some features with the desired characteristics for controlling the translational and yaw motions of a UAV have been presented. In designing a vision-based control method for a UAV quadrotor, there are some challenges, including the target mobility and not knowing the height of UAV above the target. Also, no sensor has been installed on the moving object and the changes of its yaw angle are not available. Despite all the stated challenges, the proposed method, which uses an FCM in controlling the translational motion and the yaw rotation of a UAV, adequately enables the quadrotor to follow the moving target. The simulation results for different paths show the satisfactory performance of the designed controller. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  11. An Autonomous Vision-based Localization and Control System for Quadrotor UAV%基于视觉的四旋翼无人机自主定位与控制系统

    Institute of Scientific and Technical Information of China (English)

    曹美会; 鲜斌; 张旭; 文曦

    2015-01-01

    more accurate and faster states estimation,a state-of-the-art EKF algorithm is utilized to fuse the position information within the onboard IMU readings.Based on the fused localization information,a PID and nonlinear robust RISE controller is designed to increase the robustness of the flight controller.The proposed localization and control algorithms are implemented on a self-built quadrotor UAV testbed.To avoid time delays and signal interference from the wireless transmission process,the motion states are estimated through an onboard embedded computer.Outdoor flight experimental results demonstrate that the proposed strategies achieve good autonomous control performance.

  12. Quad-rotor flight path energy optimization

    Science.gov (United States)

    Kemper, Edward

    Quad-Rotor unmanned areal vehicles (UAVs) have been a popular area of research and development in the last decade, especially with the advent of affordable microcontrollers like the MSP 430 and the Raspberry Pi. Path-Energy Optimization is an area that is well developed for linear systems. In this thesis, this idea of path-energy optimization is extended to the nonlinear model of the Quad-rotor UAV. The classical optimization technique is adapted to the nonlinear model that is derived for the problem at hand, coming up with a set of partial differential equations and boundary value conditions to solve these equations. Then, different techniques to implement energy optimization algorithms are tested using simulations in Python. First, a purely nonlinear approach is used. This method is shown to be computationally intensive, with no practical solution available in a reasonable amount of time. Second, heuristic techniques to minimize the energy of the flight path are tested, using Ziegler-Nichols' proportional integral derivative (PID) controller tuning technique. Finally, a brute force look-up table based PID controller is used. Simulation results of the heuristic method show that both reliable control of the system and path-energy optimization are achieved in a reasonable amount of time.

  13. STABILIZED CONTROLLER DESIGN FOR ATTITUDE AND ALTITUDE CONTROLLING OF QUAD-ROTOR UNDER DISTURBANCE AND NOISY CONDITIONS

    Directory of Open Access Journals (Sweden)

    M. Hassan Tanveer

    2013-01-01

    Full Text Available This article presents a control approach to obtain the better stabilization in attitude and altitude of quad-rotor under different disturbance conditions. In the standard Quad-rotor rotor type UAV, controlling of attitude and altitude is one of the most critical tasks and appropriate controller for stabilization of UAV is essential and necessary. These two controls under various conditions of disturbances was a field of research stimulating for the researchers. The controller proposed is contingent on the PID feedback structure with Extended Kalman Filter (EKF. From Lyapunov Stability Theorem, it is proved that quad-rotor proposed altitude control system is asymptotic as well exponentially stability. Extended Kalman Filter (EKF is used to filter out the sensors and system noises. Finally, the simulations carried out on MATLAB and the result proved the effectiveness of proposed recommended method for stabilization of attitude and altitude of quad-rotor.

  14. RECONNAISSANCE MICRO UAV SYSTEM

    Directory of Open Access Journals (Sweden)

    Petr Gabrlik

    2015-12-01

    Full Text Available This paper describes the design and implementation of the Uranus UAV. This quad-rotor flying robot was created to extend the abilities of the hitherto developed with airborne missions. The first part deals with the mathematical model of the robot. Next, the control system is designed, and the proposed hardware as well as the implemented software solution are presented. For integration into the robotic system, a new communication protocol was created and is described here too.

  15. Stabilization and control of quad-rotor helicopter using a smartphone device

    Science.gov (United States)

    Desai, Alok; Lee, Dah-Jye; Moore, Jason; Chang, Yung-Ping

    2013-01-01

    In recent years, autonomous, micro-unmanned aerial vehicles (micro-UAVs), or more specifically hovering micro- UAVs, have proven suitable for many promising applications such as unknown environment exploration and search and rescue operations. The early versions of UAVs had no on-board control capabilities, and were difficult for manual control from a ground station. Many UAVs now are equipped with on-board control systems that reduce the amount of control required from the ground-station operator. However, the limitations on payload, power consumption and control without human interference remain the biggest challenges. This paper proposes to use a smartphone as the sole computational device to stabilize and control a quad-rotor. The goal is to use the readily available sensors in a smartphone such as the GPS, the accelerometer, the rate-gyros, and the camera to support vision-related tasks such as flight stabilization, estimation of the height above ground, target tracking, obstacle detection, and surveillance. We use a quad-rotor platform that has been built in the Robotic Vision Lab at Brigham Young University for our development and experiments. An Android smartphone is connected through the USB port to an external hardware that has a microprocessor and circuitries to generate pulse-width modulation signals to control the brushless servomotors on the quad-rotor. The high-resolution camera on the smartphone is used to detect and track features to maintain a desired altitude level. The vision algorithms implemented include template matching, Harris feature detector, RANSAC similarity-constrained homography, and color segmentation. Other sensors are used to control yaw, pitch, and roll of the quad-rotor. This smartphone-based system is able to stabilize and control micro-UAVs and is ideal for micro-UAVs that have size, weight, and power limitations.

  16. A quadrotor application

    Directory of Open Access Journals (Sweden)

    Chabir Karim

    2014-12-01

    Full Text Available This paper considers the problem of attitude sensor fault diagnosis in a quadrotor helicopter. The proposed approach is composed of two stages. The first one is the modelling of the system attitude dynamics taking into account the induced communication constraints. Then a robust fault detection and evaluation scheme is proposed using a post-filter designed under a particular design objective. This approach is compared with previous results based on the standard Kalman filter and gives better results for sensor fault diagnosis.

  17. An indirect adaptive neural control of a visual-based quadrotor robot for pursuing a moving target.

    Science.gov (United States)

    Shirzadeh, Masoud; Amirkhani, Abdollah; Jalali, Aliakbar; Mosavi, Mohammad R

    2015-11-01

    This paper aims to use a visual-based control mechanism to control a quadrotor type aerial robot which is in pursuit of a moving target. The nonlinear nature of a quadrotor, on the one hand, and the difficulty of obtaining an exact model for it, on the other hand, constitute two serious challenges in designing a controller for this UAV. A potential solution for such problems is the use of intelligent control methods such as those that rely on artificial neural networks and other similar approaches. In addition to the two mentioned problems, another problem that emerges due to the moving nature of a target is the uncertainty that exists in the target image. By employing an artificial neural network with a Radial Basis Function (RBF) an indirect adaptive neural controller has been designed for a quadrotor robot in search of a moving target. The results of the simulation for different paths show that the quadrotor has efficiently tracked the moving target.

  18. Estabilización Visual de un Quadrotor

    OpenAIRE

    2015-01-01

    International audience; El presente documento trata sobre la estabilización basada en la imagen de un vehículo aéreo no tripulado UAVs tipo quadrotor (AR-Drone 2.0 de Parrot) que obtiene información mediante su cámara frontal. Se aplica la Técnica de Control Visual Basada en Imagen (IBVS, por sus siglas en ingles), y se hace uso del meta sistema operativo ROS mediante el lenguaje C++, algunas librerias de ViSP y una configuración del tipo ojo-en-mano (eye-in-hand) para procesar los datos obte...

  19. PID self tuning control based on Mamdani fuzzy logic control for quadrotor stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Priyambodo, Tri Kuntoro, E-mail: mastri@ugm.ac.id; Putra, Agfianto Eko [Aerospace and Aeronautics Electronics Research Group, Universitas Gadjah Mada, Yogyakarta (Indonesia); Department of Computer Science and Electronics, Universitas Gadjah Mada, Yogyakarta (Indonesia); Dharmawan, Andi, E-mail: andi-dharmawan@ugm.ac.id [Department of Computer Science and Electronics, Universitas Gadjah Mada, Yogyakarta (Indonesia)

    2016-02-01

    Quadrotor as one type of UAV have the ability to perform Vertical Take Off and Landing (VTOL). It allows the Quadrotor to be stationary hovering in the air. PID (Proportional Integral Derivative) control system is one of the control methods that are commonly used. It is usually used to optimize the Quadrotor stabilization at least based on the three Eulerian angles (roll, pitch, and yaw) as input parameters for the control system. The three constants of PID can be obtained in various methods. The simplest method is tuning manually. This method has several weaknesses. For example if the three constants are not exact, the resulting response will deviate from the desired result. By combining the methods of PID with fuzzy logic systems where human expertise is implemented into the machine language is expected to further optimize the control system.

  20. Hummingbird Citizen Science

    Science.gov (United States)

    Givot, Rima; O'Connell, Kari; Hadley, Adam S.; Betts, Matthew G.

    2015-01-01

    The decline in hummingbird populations and shifts in their movements may adversely affect their role as pollinators and, in turn, plant biodiversity (Allen-Wardell et al. 1998). For example, Hadley et al. (2014) discovered that larger fragments of forest correlated with larger hummingbird populations and more seeds of "H. tortuosa" being…

  1. Adaptive formation control of quadrotor unmanned aerial vehicles with bounded control thrust

    Directory of Open Access Journals (Sweden)

    Rui Wang

    2017-04-01

    Full Text Available In this paper, the flight formation control problem of a group of quadrotor unmanned aerial vehicles (UAVs with parametric uncertainties and external disturbances is studied. Unit-quaternions are used to represent the attitudes of the quadrotor UAVs. Separating the model into a translational subsystem and a rotational subsystem, an intermediary control input is introduced to track a desired velocity and extract desired orientations. Then considering the internal parametric uncertainties and external disturbances of the quadrotor UAVs, the priori-bounded intermediary adaptive control input is designed for velocity tracking and formation keeping, by which the bounded control thrust and the desired orientation can be extracted. Thereafter, an adaptive control torque input is designed for the rotational subsystem to track the desired orientation. With the proposed control scheme, the desired velocity is tracked and a desired formation shape is built up. Global stability of the closed-loop system is proven via Lyapunov-based stability analysis. Numerical simulation results are presented to illustrate the effectiveness of the proposed control scheme.

  2. Nonlinear Control of an Autonomous Quadrotor Unmanned Aerial Vehicle using Backstepping Controller Optimized by Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Mohd Ariffanan Mohd Basri

    2015-09-01

    Full Text Available Quadrotor unmanned aerial vehicle (UAV is an unstable nonlinear control system. Therefore, the development of a high performance controller for such a multi-input and multi-output (MIMO system is important. The backstepping controller (BC has been successfully applied to control a variety of nonlinear systems. Conventionally, control parameters of a BC are usually chosen arbitrarily. The problems in this method are the adjustment is time demanding and a designer can never tell exactly what are the optimal control parameters should be selected. In this paper, the contribution is focused on an optimal control design for stabilization and trajectory tracking of a quadrotor UAV. Firstly, a dynamic model of the aerial vehicle is mathematically formulated. Then, an optimal backstepping controller (OBC is proposed. The particle swarm optimization (PSO algorithm is used to compute control parameters of the OBC. Finally, simulation results of a highly nonlinear quadrotor system are presented to demonstrate the effectiveness of the proposed control method. From the simulation results it is observed that the OBC tuned by PSO provides a high control performance of an autonomous quadrotor UAV.

  3. Quaternion-based nonlinear trajectory tracking control of a quadrotor unmanned aerial vehicle

    Science.gov (United States)

    Zha, Changliu; Ding, Xilun; Yu, Yushu; Wang, Xueqiang

    2017-01-01

    At present, most controllers of quadrotor unmanned aerial vehicles(UAVs) use Euler angles to express attitude. These controllers suffer a singularity problem when the pitch angle is near 90°C, which limits the maneuverability of the UAV. To overcome this problem, based on the quaternion attitude representation, a 6 degree of freedom(DOF) nonlinear controller of a quadrotor UAV is designed using the trajectory linearization control(TLC) method. The overall controller contains a position sub-controller and an attitude sub-controller. The two controllers regulate the translational and rotational motion of the UAV, respectively. The controller is improved by using the commanded value instead of the nominal value as the input of the inner control loop. The performance of controller is tested by simulation before and after the improvement, the results show that the improved controller is better. The proposed controller is also tested via numerical simulation and real flights and is compared with the traditional controller based on Euler angles. The test results confirm the feasibility and the robustness of the proposed nonlinear controller. The proposed controller can successfully solve the singularity problem that usually occurs in the current attitude control of UAV and it is easy to be realized.

  4. An experimental stationary quadrotor with variable DOF

    Indian Academy of Sciences (India)

    Vasfi Emre Ömürlü; Utku Büyükşahin; Remzi Artar; Ahmet Kirli; M Nurullah Turgut

    2013-04-01

    Unmanned air vehicles (UAV) and especially quadrotors have drawn great attention in recent years because of their maneuverability, ease of design and control. Most of the works concentrate mostly on control; yet, design and communication are also some sub-topics. In this research, a stationary, four rotor air vehicle with limited/controlled degree of freedom is constructed so that various control algorithms and their changing effects with varying vehicle dynamics can be studied on the ground for safety purposes. Ascending/descending, pitch/yaw/roll motions can be limited/controlled by setting the vehicle’s degree of freedom mechanically, resulting better net observability of the control algorithms on the vehicle’s dynamic performance. Design, in terms of mechanics, mechatronics and software is presented and the usability of the system is shown. Parallel self tuning fuzzy PD + PD control is applied to the system for preliminary studies and results are discussed. Inspite of the sensor noise, satisfactory pitch/roll/yaw control is achieved.

  5. Adaptive Navigation Control for Quadrotor Unmanned Aerial Vehicles%四旋翼无人机自适应导航控制

    Institute of Scientific and Technical Information of China (English)

    潘海珠

    2012-01-01

    Navigation control problem of Quadrotor Unmanned Aerial Vehicles was studied. Conventional Quadro-tor UAVs navigation control methods have the problems such as target positon error and poor real-time. In the paper, a Quadrotor UAVs navigation control method was proposed based on CLOS. CLOS was adapted for systematic naviga-tion control system design which enables the maneuver Quadrotor UAVs to accomplish the task of navigating and land-ing on an onboard mobile helipad autonomously. In this paper, the research has been very detailed in both control system design and simulation. Simulation results show the performance and effectiveness of the navigation control sys-tem. It can be applied to the real-time navigation of Quadrotor UAVs.%研究四旋翼(Quadrotor)无人机导航控制问题.针对传统的四旋翼无人机导航控制方法的目标定位误差和实时性差问题,提出了基于CLOS技术的导航控制方法.采用CLOS技术所开发的导航控制系统使得四旋翼无人机能够在移动停机坪完成自主导航和着陆的任务,并详细研究了导航控制系统的设计和仿真.仿真结果显示了所设计的导航控制系统的性能和有效性,可应用于四旋翼无人机的实时导航.

  6. 应用于四旋翼无人机角速度估计的几何滑模观测器设计%Geometric sliding mode observer design with application to angular velocity estimation of quadrotor UAV

    Institute of Scientific and Technical Information of China (English)

    安宏雷; 李杰; 王剑; 王建文; 马宏绪

    2013-01-01

    Traditional quaternion-based sliding mode observer for angular velocity estimating has to introduce the process of mandatory rescaling which affects the tracking performance of the observer algorithm.In this work,a sliding mode observer design framework is proposed, based on the Lie group method of numerical integration on manifolds for angular velocity estimation of quadrotor attitude.The algorithm constructs sliding mode feedback in the space of equivalent Lie algebra of homogeneous manifolds on the basis of equivariant mapping ideological.It avoids the complexity of constructing sliding mode feedback in homogeneous space directly,and eliminates the process of mandatory rescaling which is required by the traditional methods in each integration step.The simulation results show that the algorithm of geometric sliding mode observer is effective.%对四旋翼无人机的角速度进行估计时,传统的基于单位四元数的滑模观测器需要引入强制比例重调,因而影响了跟踪精度。提出一种基于数值积分的李群方法的滑模观测器设计框架。该算法基于等变映射思想,在齐性流形空间的等价李代数空间中设计滑模反馈,从而避免了直接在流形空间中设计反馈的复杂性,并消除了传统方法在每个积分步骤中强制加入的比例重调,提高了观测器的跟踪性能。仿真结果表明,几何滑模观测器算法可以有效地对四旋翼无人机的角速度进行估计。

  7. Optimal Path Planning and Control of Quadrotor Unmanned Aerial Vehicle for Area Coverage

    Science.gov (United States)

    Fan, Jiankun

    An Unmanned Aerial Vehicle (UAV) is an aircraft without a human pilot on board. Its flight is controlled either autonomously by computers onboard the vehicle, or remotely by a pilot on the ground, or by another vehicle. In recent years, UAVs have been used more commonly than prior years. The example includes areo-camera where a high speed camera was attached to a UAV which can be used as an airborne camera to obtain aerial video. It also could be used for detecting events on ground for tasks such as surveillance and monitoring which is a common task during wars. Similarly UAVs can be used for relaying communication signal during scenarios when regular communication infrastructure is destroyed. The objective of this thesis is motivated from such civilian operations such as search and rescue or wildfire detection and monitoring. One scenario is that of search and rescue where UAV's objective is to geo-locate a person in a given area. The task is carried out with the help of a camera whose live feed is provided to search and rescue personnel. For this objective, the UAV needs to carry out scanning of the entire area in the shortest time. The aim of this thesis to develop algorithms to enable a UAV to scan an area in optimal time, a problem referred to as "Coverage Control" in literature. The thesis focuses on a special kind of UAVs called "quadrotor" that is propelled with the help of four rotors. The overall objective of this thesis is achieved via solving two problems. The first problem is to develop a dynamic control model of quadrtor. In this thesis, a proportional-integral-derivative controller (PID) based feedback control system is developed and implemented on MATLAB's Simulink. The PID controller helps track any given trajectory. The second problem is to design a trajectory that will fulfill the mission. The planed trajectory should make sure the quadrotor will scan the whole area without missing any part to make sure that the quadrotor will find the lost

  8. Comparative Results on 3D Navigation of Quadrotor using two Nonlinear Model based Controllers

    Science.gov (United States)

    Bouzid, Y.; Siguerdidjane, H.; Bestaoui, Y.

    2017-01-01

    Recently the quadrotors are being increasingly employed in both military and civilian areas where a broad range of nonlinear flight control techniques are successfully implemented. With this advancement, it has become necessary to investigate the efficiency of these flight controllers by studying theirs features and compare their performance. In this paper, the control of Unmanned Aerial Vehicle (UAV) quadrotor, using two different approaches, is presented. The first controller is Nonlinear PID (NLPID) whilst the second one is Nonlinear Internal Model Control (NLIMC) that are used for the stabilization as well as for the 3D trajectory tracking. The numerical simulations have shown satisfactory results using nominal system model or disturbed model for both of them. The obtained results are analyzed with respect to several criteria for the sake of comparison.

  9. Leader-Follower Formation Control for Quadrotors

    Science.gov (United States)

    Wu, Falin; Chen, Jiemin; Liang, Yuan

    2017-03-01

    Quadrotors are gaining an increasing interest in public and extensively explored in recent years. In many situations, a team of quadrotors is desired to operate in a certain shape, which is also called formation. In this paper, a linear PID controller is used to control each single quadrotor and a slide mode controller is adopted to solve the formation flying problem which employs the leader-follower structure. The formation simulations are run in the Matlab/Simulink environment to evaluate the performance of control laws.

  10. Aerodynamics of Rotor Blades for Quadrotors

    CERN Document Server

    Bangura, Moses; Naldi, Roberto; Mahony, Robert

    2016-01-01

    In this report, we present the theory on aerodynamics of quadrotors using the well established momentum and blade element theories. From a robotics perspective, the theoretical development of the models for thrust and horizontal forces and torque (therefore power) are carried out in the body fixed frame of the quadrotor. Using momentum theory, we propose and model the existence of a horizontal force along with its associated power. Given the limitations associated with momentum theory and the inadequacy of the theory to account for the different powers represented in a proposed bond graph lead to the use of blade element theory. Using this theory, models are then developed for the different quadrotor rotor geometries and aerodynamic properties including the optimum hovering rotor used on the majority of quadrotors. Though this rotor is proven to be the most optimum rotor, we show that geometric variations are necessary for manufacturing of the blades. The geometric variations are also dictated by a desired th...

  11. Asymptotic Vision-Based Tracking Control of the Quadrotor Aerial Vehicle

    Directory of Open Access Journals (Sweden)

    Hamed Jabbari Asl

    2015-01-01

    Full Text Available This paper proposes an image-based visual servo (IBVS controller for the 3D translational motion of the quadrotor unmanned aerial vehicles (UAV. The main purpose of this paper is to provide asymptotic stability for vision-based tracking control of the quadrotor in the presence of uncertainty in the dynamic model of the system. The aim of the paper also includes the use of flow of image features as the velocity information to compensate for the unreliable linear velocity data measured by accelerometers. For this purpose, the mathematical model of the quadrotor is presented based on the optic flow of image features which provides the possibility of designing a velocity-free IBVS controller with considering the dynamics of the robot. The image features are defined from a suitable combination of perspective image moments without using the model of the object. This property allows the application of the proposed controller in unknown places. The controller is robust with respect to the uncertainties in the translational dynamics of the system associated with the target motion, image depth, and external disturbances. Simulation results and a comparison study are presented which demonstrate the effectiveness of the proposed approach.

  12. Swing-attenuation for a quadrotor transporting a cable-suspended payload.

    Science.gov (United States)

    Guerrero-Sánchez, M Eusebia; Mercado-Ravell, D Alberto; Lozano, Rogelio; García-Beltrán, C Daniel

    2017-02-13

    This paper presents the problem of safe and fast transportation of packages by an Unmanned Aerial Vehicle (UAV) kind quadrotor. A mathematical model and a control strategy for a special class of underactuated mechanical systems, composed of a quadrotor transporting a cable-suspended payload, are proposed. The Euler-Lagrange formulation is used to obtain the dynamic model of the system, where the integrated dynamics of the quadrotor, cable and payload are considered. An Interconnection and Damping Assignment-Passivity Based Control (IDA-PBC) is chosen because of its inherent robustness against parametric uncertainty and unmodeled dynamics. Two cases are considered to obtain two different control laws, in the first case, the designed control law depends on the swing angle of the payload, in the second case the control law does not depend on it. The control objective is to transport the payload from point to point, with swing reduction along trajectory. Experimental results using monocular vision based navigation are shown to evaluate the proposed control law.

  13. Design of passive fault-tolerant controllers of a quadrotor based on sliding mode theory

    Directory of Open Access Journals (Sweden)

    Merheb Abdel-Razzak

    2015-09-01

    Full Text Available Abstract In this paper, sliding mode control is used to develop two passive fault tolerant controllers for an AscTec Pelican UAV quadrotor. In the first approach, a regular sliding mode controller (SMC augmented with an integrator uses the robustness property of variable structure control to tolerate partial actuator faults. The second approach is a cascaded sliding mode controller with an inner and outer SMC loops. In this configuration, faults are tolerated in the fast inner loop controlling the velocity system. Tuning the controllers to find the optimal values of the sliding mode controller gains is made using the ecological systems algorithm (ESA, a biologically inspired stochastic search algorithm based on the natural equilibrium of animal species. The controllers are tested using SIMULINK in the presence of two different types of actuator faults, partial loss of motor power affecting all the motors at once, and partial loss of motor speed. Results of the quadrotor following a continuous path demonstrated the effectiveness of the controllers, which are able to tolerate a significant number of actuator faults despite the lack of hardware redundancy in the quadrotor system. Tuning the controller using a faulty system improves further its ability to afford more severe faults. Simulation results show that passive schemes reserve their important role in fault tolerant control and are complementary to active techniques

  14. Modeling and Decentralized Control for the Multiple UAVs Formation based on Lyapunov design and redesign

    OpenAIRE

    Hou, Zhicheng; Fantoni, Isabelle; Zavala-Río, Arturo

    2013-01-01

    International audience; This paper concerns the leader-follower multiple agent formation with nonlinear and coupled individual dynamics. We address the problem of multi-agent formation control by proposing a decentralized control strategy. The agents in the formation are quad-rotors UAVs. By attributing the high-order nonlinear and unmodelled dynamics as uncertainties, we propose a switching singular system model to represent the formation of the multiple UAVs system with switching topology. ...

  15. Comparison of gradient methods for gain tuning of a PD controller applied on a quadrotor system

    Science.gov (United States)

    Kim, Jinho; Wilkerson, Stephen A.; Gadsden, S. Andrew

    2016-05-01

    Many mechanical and electrical systems have utilized the proportional-integral-derivative (PID) control strategy. The concept of PID control is a classical approach but it is easy to implement and yields a very good tracking performance. Unmanned aerial vehicles (UAVs) are currently experiencing a significant growth in popularity. Due to the advantages of PID controllers, UAVs are implementing PID controllers for improved stability and performance. An important consideration for the system is the selection of PID gain values in order to achieve a safe flight and successful mission. There are a number of different algorithms that can be used for real-time tuning of gains. This paper presents two algorithms for gain tuning, and are based on the method of steepest descent and Newton's minimization of an objective function. This paper compares the results of applying these two gain tuning algorithms in conjunction with a PD controller on a quadrotor system.

  16. Floral arrangements and hummingbird feeding.

    Science.gov (United States)

    Hainsworth, F Reed; Mercier, Theresa; Wolf, Larry L

    1983-05-01

    The influence of simulated inflorescence design on feeding behavior of 3 male Eugenes fulgens (Rivoli's hummingbird) and one female Lampornis clemenciae (Bluethroated hummingbird) was studied in the laboratory using artificial flowers. Five two-dimensional and three three-dimensional arrangements provided constant rewards per artificial flower. Visits to two-dimensional arrangements had more flower visits per feeding bout, proportionally more flower revisits, and shorter time between flowers than visits to three-dimensional arrangements. This suggests inflorescence design may influence pollen movement by hummingbirds.

  17. Extending Quad-Rotor UAV Autonomy with Onboard Image Processing

    Science.gov (United States)

    2015-03-01

    model is provided from Quanser and uses for Matlab 2011a and Simulink , which are produced by The Mathworks. Additionally, Quanser provides the Quanser...30 Figure 17. Joystick Controller Simulink model, which is separate from the main control model...Real-Time Control (QuaRC) toolbox, which adds specialized features and an additional Simulink block set, allowing the user to rapidly test different

  18. System and mathematical modeling of quadrotor dynamics

    Science.gov (United States)

    Goodman, Jacob M.; Kim, Jinho; Gadsden, S. Andrew; Wilkerson, Stephen A.

    2015-05-01

    Unmanned aerial systems (UAS) are becoming increasingly visible in our daily lives; and range in operation from search and rescue, monitoring hazardous environments, and to the delivery of goods. One of the most popular UAS are based on a quad-rotor design. These are typically small devices that rely on four propellers for lift and movement. Quad-rotors are inherently unstable, and rely on advanced control methodologies to keep them operating safely and behaving in a predictable and desirable manner. The control of these devices can be enhanced and improved by making use of an accurate dynamic model. In this paper, we examine a simple quadrotor model, and note some of the additional dynamic considerations that were left out. We then compare simulation results of the simple model with that of another comprehensive model.

  19. Large-scale stabilization control of input-constrained quadrotor

    Directory of Open Access Journals (Sweden)

    Jun Jiang

    2016-10-01

    Full Text Available The quadrotor has been the most popular aircraft in the last decade due to its excellent dynamics and continues to attract ever-increasing research interest. Delivering a quadrotor from a large fixed-wing aircraft is a promising application of quadrotors. In such an application, the quadrotor needs to switch from a highly unstable status, featured as large initial states, to a safe and stable flight status. This is the so-called large-scale stability control problem. In such an extreme scenario, the quadrotor is at risk of actuator saturation. This can cause the controller to update incorrectly and lead the quadrotor to spiral and crash. In this article, to safely control the quadrotor in such scenarios, the control input constraint is analyzed. The key states of a quadrotor dynamic model are selected, and a two-dimensional dynamic model is extracted based on a symmetrical body configuration. A generalized point-wise min-norm nonlinear control method is proposed based on the Lyapunov function, and large-scale stability control is hence achieved. An enhanced point-wise, min-norm control is further provided to improve the attitude control performance, with altitude performance degenerating slightly. Simulation results showed that the proposed control methods can stabilize the input-constrained quadrotor and the enhanced method can improve the performance of the quadrotor in critical states.

  20. Actuator Fault Detection and Diagnosis for Quadrotors

    NARCIS (Netherlands)

    Lu, P.; Van Kampen, E.-J.; Yu, B.

    2014-01-01

    This paper presents a method for fault detection and diagnosis of actuator loss of effectiveness for a quadrotor helicopter. This paper not only considers the detection of the actuator loss of effectiveness faults, but also addresses the diagnosis of the faults. The detection and estimation of the f

  1. Towards a Low-Cost Quadrotor Research Platform

    Science.gov (United States)

    2010-03-01

    FIGURES Figure 1. Quadrotor schematic showing rotor direction of rotation (From [2])................3 Figure 2. Toy quadrotor: Walkera UFO (from...Some examples are the Walkera UFO #5, Walkera UFO #8, Dragonfly, and Alien Air Jump Jet. Figure 2. Toy quadrotor: Walkera UFO (from Walkera...the X- UFO made by Silverlit Electronics used small mechanical gyros. These were relatively cheap due to low-cost labor, but suffered from mechanical

  2. Intelligent Controller Design for Quad-Rotor Stabilization in Presence of Parameter Variations

    Directory of Open Access Journals (Sweden)

    Oualid Doukhi

    2017-01-01

    Full Text Available The paper presents the mathematical model of a quadrotor unmanned aerial vehicle (UAV and the design of robust Self-Tuning PID controller based on fuzzy logic, which offers several advantages over certain types of conventional control methods, specifically in dealing with highly nonlinear systems and parameter uncertainty. The proposed controller is applied to the inner and outer loop for heading and position trajectory tracking control to handle the external disturbances caused by the variation in the payload weight during the flight period. The results of the numerical simulation using gazebo physics engine simulator and real-time experiment using AR drone 2.0 test bed demonstrate the effectiveness of this intelligent control strategy which can improve the robustness of the whole system and achieve accurate trajectory tracking control, comparing it with the conventional proportional integral derivative (PID.

  3. Sampled-Data Backstepping Control of a Quadrotor Unmanned Aerial Vehicle

    Directory of Open Access Journals (Sweden)

    Abdul Jabbar

    2014-12-01

    Full Text Available Sampled-data backstepping control of a quadrotor UAV is presented in this paper. The discrete time controllers have been designed on the basis of a continuous time system model and an approximate discrete time equivalent system model (Euler Approximate model obtained using the Euler method. The performance of the controllers obtained using the two sampled-data approaches has been compared in the presence of wing gusts and modeling uncertainties. Simulations have revealed that the backstepping controller designed on the basis of an approximate discrete time model has better performance in the presence of wind gusts and modeling uncertainties. In addition, the closed loop system has a larger region of attraction.

  4. Mini-UAV based sensory system for measuring environmental variables in greenhouses.

    Science.gov (United States)

    Roldán, Juan Jesús; Joossen, Guillaume; Sanz, David; del Cerro, Jaime; Barrientos, Antonio

    2015-02-02

    This paper describes the design, construction and validation of a mobile sensory platform for greenhouse monitoring. The complete system consists of a sensory system on board a small quadrotor (i.e., a four rotor mini-UAV). The goals of this system include taking measures of temperature, humidity, luminosity and CO2 concentration and plotting maps of these variables. These features could potentially allow for climate control, crop monitoring or failure detection (e.g., a break in a plastic cover). The sensors have been selected by considering the climate and plant growth models and the requirements for their integration onboard the quadrotor. The sensors layout and placement have been determined through a study of quadrotor aerodynamics and the influence of the airflows from its rotors. All components of the system have been developed, integrated and tested through a set of field experiments in a real greenhouse. The primary contributions of this paper are the validation of the quadrotor as a platform for measuring environmental variables and the determination of the optimal location of sensors on a quadrotor.

  5. Mini-UAV Based Sensory System for Measuring Environmental Variables in Greenhouses

    Science.gov (United States)

    Roldán, Juan Jesús; Joossen, Guillaume; Sanz, David; del Cerro, Jaime; Barrientos, Antonio

    2015-01-01

    This paper describes the design, construction and validation of a mobile sensory platform for greenhouse monitoring. The complete system consists of a sensory system on board a small quadrotor (i.e., a four rotor mini-UAV). The goals of this system include taking measures of temperature, humidity, luminosity and CO2 concentration and plotting maps of these variables. These features could potentially allow for climate control, crop monitoring or failure detection (e.g., a break in a plastic cover). The sensors have been selected by considering the climate and plant growth models and the requirements for their integration onboard the quadrotor. The sensors layout and placement have been determined through a study of quadrotor aerodynamics and the influence of the airflows from its rotors. All components of the system have been developed, integrated and tested through a set of field experiments in a real greenhouse. The primary contributions of this paper are the validation of the quadrotor as a platform for measuring environmental variables and the determination of the optimal location of sensors on a quadrotor. PMID:25648713

  6. Mini-UAV Based Sensory System for Measuring Environmental Variables in Greenhouses

    Directory of Open Access Journals (Sweden)

    Juan Jesús Roldán

    2015-02-01

    Full Text Available This paper describes the design, construction and validation of a mobile sensory platform for greenhouse monitoring. The complete system consists of a sensory system on board a small quadrotor (i.e., a four rotor mini-UAV. The goals of this system include taking measures of temperature, humidity, luminosity and CO2 concentration and plotting maps of these variables. These features could potentially allow for climate control, crop monitoring or failure detection (e.g., a break in a plastic cover. The sensors have been selected by considering the climate and plant growth models and the requirements for their integration onboard the quadrotor. The sensors layout and placement have been determined through a study of quadrotor aerodynamics and the influence of the airflows from its rotors. All components of the system have been developed, integrated and tested through a set of field experiments in a real greenhouse. The primary contributions of this paper are the validation of the quadrotor as a platform for measuring environmental variables and the determination of the optimal location of sensors on a quadrotor.

  7. An RFID Based Smart Feeder for Hummingbirds.

    Science.gov (United States)

    Ibarra, Vicente; Araya-Salas, Marcelo; Tang, Yu-ping; Park, Charlie; Hyde, Anthony; Wright, Timothy F; Tang, Wei

    2015-12-16

    We present an interdisciplinary effort to record feeding behaviors and control the diet of a hummingbird species (Phaethornis longirostris, the long-billed hermit or LBH) by developing a Radio Frequency Identification (RFID) based smart feeder. The system contains an RFID reader, a microcontroller, and a servo-controlled hummingbird feeder opener; the system is presented as a tool for studying the cognitive ability of the LBH species. When equipped with glass capsule RFID tags (which are mounted on the hummingbird), the smart feeder can provide specific diets for predetermined sets of hummingbirds at the discretion of biologists. This is done by reading the unique RFID tag on the hummingbirds and comparing the ID number with the pre-programmed ID numbers stored in the smart feeder. The smart feeder records the time and ID of each hummingbird visit. The system data is stored in a readily available SD card and is powered by two 9 V batteries. The detection range of the system is approximately 9-11 cm. Using this system, biologists can assign the wild hummingbirds to different experimental groups and monitor their diets to determine if they develop a preference to any of the available nectars. During field testing, the smart feeder system has demonstrated consistent detection (when compared to detections observed by video-recordings) of RFID tags on hummingbirds and provides pre-designed nectars varying water and sugar concentrations to target individuals. The smart feeder can be applied to other biological and environmental studies in the future.

  8. Molecular phylogenetics and the diversification of hummingbirds.

    Science.gov (United States)

    McGuire, Jimmy A; Witt, Christopher C; Remsen, J V; Corl, Ammon; Rabosky, Daniel L; Altshuler, Douglas L; Dudley, Robert

    2014-04-14

    The tempo of species diversification in large clades can reveal fundamental evolutionary mechanisms that operate on large temporal and spatial scales. Hummingbirds have radiated into a diverse assemblage of specialized nectarivores comprising 338 species, but their evolutionary history has not, until now, been comprehensively explored. We studied hummingbird diversification by estimating a time-calibrated phylogeny for 284 hummingbird species, demonstrating that hummingbirds invaded South America by ∼22 million years ago, and subsequently diversified into nine principal clades (see [5-7]). Using ancestral state reconstruction and diversification analyses, we (1) estimate the age of the crown-group hummingbird assemblage, (2) investigate the timing and patterns of lineage accumulation for hummingbirds overall and regionally, and (3) evaluate the role of Andean uplift in hummingbird speciation. Detailed analyses reveal disparate clade-specific processes that allowed for ongoing species diversification. One factor was significant variation among clades in diversification rates. For example, the nine principal clades of hummingbirds exhibit ∼15-fold variation in net diversification rates, with evidence for accelerated speciation of a clade that includes the Bee, Emerald, and Mountain Gem groups of hummingbirds. A second factor was colonization of key geographic regions, which opened up new ecological niches. For example, some clades diversified in the context of the uplift of the Andes Mountains, whereas others were affected by the formation of the Panamanian land bridge. Finally, although species accumulation is slowing in all groups of hummingbirds, several major clades maintain rapid rates of diversification on par with classical examples of rapid adaptive radiation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. A Survey of Modelling and Identification of Quadrotor Robot

    Directory of Open Access Journals (Sweden)

    Xiaodong Zhang

    2014-01-01

    Full Text Available A quadrotor is a rotorcraft capable of hover, forward flight, and VTOL and is emerging as a fundamental research and application platform at present with flexibility, adaptability, and ease of construction. Since a quadrotor is basically considered an unstable system with the characteristics of dynamics such as being intensively nonlinear, multivariable, strongly coupled, and underactuated, a precise and practical model is critical to control the vehicle which seems to be simple to operate. As a rotorcraft, the dynamics of a quadrotor is mainly dominated by the complicated aerodynamic effects of the rotors. This paper gives a tutorial of the platform configuration, methodology of modeling, comprehensive nonlinear model, the aerodynamic effects, and model identification for a quadrotor.

  10. Design of a quadrotor flight test stand for system identification

    CSIR Research Space (South Africa)

    Beharie, MM

    2015-01-01

    Full Text Available the mathematical model was used to simulate. Each phase in the mission profile excited different modes of the quadrotor dynamics creating an ideal simulation environment in which changes can be implemented and studied....

  11. Development and Testing of a Two-UAV Communication Relay System.

    Science.gov (United States)

    Li, Boyang; Jiang, Yifan; Sun, Jingxuan; Cai, Lingfeng; Wen, Chih-Yung

    2016-10-13

    In the development of beyond-line-of-sight (BLOS) Unmanned Aerial Vehicle (UAV) systems, communication between the UAVs and the ground control station (GCS) is of critical importance. The commonly used economical wireless modules are restricted by the short communication range and are easily blocked by obstacles. The use of a communication relay system provides a practical way to solve these problems, improving the performance of UAV communication in BLOS and cross-obstacle operations. In this study, a communication relay system, in which a quadrotor was used to relay radio communication for another quadrotor was developed and tested. First, the UAVs used as the airborne platform were constructed, and the hardware for the communication relay system was selected and built up. Second, a set of software programs and protocol for autonomous mission control, communication relay control, and ground control were developed. Finally, the system was fully integrated into the airborne platform and tested both indoor and in-flight. The Received Signal Strength Indication (RSSI) and noise value in two typical application scenarios were recorded. The test results demonstrated the ability of this system to extend the communication range and build communication over obstacles. This system also shows the feasibility to coordinate multiple UAVs' communication with the same relay structure.

  12. Amphibious UAV

    Data.gov (United States)

    National Aeronautics and Space Administration — This Amphibious UAV, less than 10 meters in length is a perfect scout for Naval Reconnaissance. It can be greatly effective for detecting incoming enemy subs or...

  13. Mercury contamination in Anna’s hummingbirds

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Heavy metal contamination (n=17 metals) of feather and tissue samples from live and deceased Anna's hummingbirds (Calypte anna) was evaluated. Feathers taken from...

  14. An RFID Based Smart Feeder for Hummingbirds

    Directory of Open Access Journals (Sweden)

    Vicente Ibarra

    2015-12-01

    Full Text Available We present an interdisciplinary effort to record feeding behaviors and control the diet of a hummingbird species (Phaethornis longirostris, the long-billed hermit or LBH by developing a Radio Frequency Identification (RFID based smart feeder. The system contains an RFID reader, a microcontroller, and a servo-controlled hummingbird feeder opener; the system is presented as a tool for studying the cognitive ability of the LBH species. When equipped with glass capsule RFID tags (which are mounted on the hummingbird, the smart feeder can provide specific diets for predetermined sets of hummingbirds at the discretion of biologists. This is done by reading the unique RFID tag on the hummingbirds and comparing the ID number with the pre-programmed ID numbers stored in the smart feeder. The smart feeder records the time and ID of each hummingbird visit. The system data is stored in a readily available SD card and is powered by two 9 V batteries. The detection range of the system is approximately 9–11 cm. Using this system, biologists can assign the wild hummingbirds to different experimental groups and monitor their diets to determine if they develop a preference to any of the available nectars. During field testing, the smart feeder system has demonstrated consistent detection (when compared to detections observed by video-recordings of RFID tags on hummingbirds and provides pre-designed nectars varying water and sugar concentrations to target individuals. The smart feeder can be applied to other biological and environmental studies in the future.

  15. 四旋翼飞行器建模及位置跟踪控制%Modelling and position tracking control for quadrotor vehicle

    Institute of Scientific and Technical Information of China (English)

    王红雨; 赵健康; 郁文贤; 田蔚风

    2012-01-01

    相对其他无人飞行器平台,四旋翼飞行器有其独特的优势,因而受到广泛的关注.位置跟踪控制对四旋翼飞行器的应用非常重要.在阐述四旋翼飞行器的飞行原理和操控机制的基础上,研究了其动力学模型,并提出了一种简化的数学模型.四旋翼飞行器是欠驱动耦合系统,为了实现系统解耦并得到清晰的控制回路,设计了多回路PID控制方案,其控制目标是位置和偏航角,而姿态角和横滚角由位置误差调节.最后,通过仿真验证了控制方法的有效性.%Quadrotor vehicles have attracted more and more interests for their distinct advantages over other unmanned air vehicles(UAVs).Position tracking control is very important for the application of the quadrotor vehicle.In this paper,the flight theory and manipulative mechanism of the quadrotor vehicle were described.The dynamic model was studied,and a simplified mathematical model was obtained.The quadrotor is a coupled under-actuated rotorcraft.In order to decouple the dynamic system and achieve clear control loops,a multi-loop PID control scheme was employed.The control goal is to make the position and yaw angle stabilized at the reference values,while the pitch and roll angles were regulated by the position errors.At last,a simulation was carried out which verified the effectiveness of the control strategy.

  16. Hummingbirds see near ultraviolet light.

    Science.gov (United States)

    Goldsmith, T H

    1980-02-15

    Three species of hummingbird (Archilochus alexandri, Lampornis clemenciae, and Eugenes fulgens) were trained to make visual discriminations between lights of different spectral content. On the basis of initial choices of feeders following a period of conditioning, birds of all three species were able to distinguish near ultraviolet (370 nanometers, 20-nanometer half bandwidth) from darkness (unilluminated viewing screen) or from the small amount of far red light that leaked through the ultraviolet-transmitting glass filter. A human observer was unable to make either discrimination. The birds were also able to distinguish white lights lacking wavelengths shorter than 400 nanometers from the full spectrum of the quartz-halogen bulbs. One can infer that the cone oil droplets, which have been lost from the retinas of most mammals, provide a potentially more flexible system for restricting the short wavelength end of the visible spectrum than does the filtering action of lens and macula that serves this function in the human eye.

  17. The Quadrotor Dynamic Modeling and Indoor Target Tracking Control Method

    Directory of Open Access Journals (Sweden)

    Dewei Zhang

    2014-01-01

    Full Text Available A reliable nonlinear dynamic model of the quadrotor is presented. The nonlinear dynamic model includes actuator dynamic and aerodynamic effect. Since the rotors run near a constant hovering speed, the dynamic model is simplified at hovering operating point. Based on the simplified nonlinear dynamic model, the PID controllers with feedback linearization and feedforward control are proposed using the backstepping method. These controllers are used to control both the attitude and position of the quadrotor. A fully custom quadrotor is developed to verify the correctness of the dynamic model and control algorithms. The attitude of the quadrotor is measured by inertia measurement unit (IMU. The position of the quadrotor in a GPS-denied environment, especially indoor environment, is estimated from the downward camera and ultrasonic sensor measurements. The validity and effectiveness of the proposed dynamic model and control algorithms are demonstrated by experimental results. It is shown that the vehicle achieves robust vision-based hovering and moving target tracking control.

  18. 四旋翼无人直升机鲁棒飞行控制%Robust Flight Control of Quadrotor Unmanned Air Vehicles

    Institute of Scientific and Technical Information of China (English)

    白永强; 刘昊; 石宗英; 钟宜生

    2012-01-01

    For quadrotor unmanned air vehicles (UAVs) flight control problem, a robust controller design approach is presented. The controller consists of two parts: an inner-loop attitude controller and an outer-loop position controller. The attitude controller is designed with robust control based on signal compensation. The position controller is realized with classical PD method. It is applied to a quadrotor UAV developed in our laboratory to realize indoor hovering. Experimental results demonstrate the effectiveness of this control approach.%讨论了四旋翼无人直升机的飞行控制问题,提出了一种鲁棒控制器设计方法.该控制器由内环姿态控制器和外环位置控制器两部分组成,姿态控制器采用基于信号补偿的鲁棒控制方法,位置控制器由经典的PD控制实现.将该控制器用于实验室自主研制的四旋翼无人直升机系统,实现了室内悬停飞行.实验结果验证了该控制方法的有效性.

  19. Development and Testing of a Two-UAV Communication Relay System

    Directory of Open Access Journals (Sweden)

    Boyang Li

    2016-10-01

    Full Text Available In the development of beyond-line-of-sight (BLOS Unmanned Aerial Vehicle (UAV systems, communication between the UAVs and the ground control station (GCS is of critical importance. The commonly used economical wireless modules are restricted by the short communication range and are easily blocked by obstacles. The use of a communication relay system provides a practical way to solve these problems, improving the performance of UAV communication in BLOS and cross-obstacle operations. In this study, a communication relay system, in which a quadrotor was used to relay radio communication for another quadrotor was developed and tested. First, the UAVs used as the airborne platform were constructed, and the hardware for the communication relay system was selected and built up. Second, a set of software programs and protocol for autonomous mission control, communication relay control, and ground control were developed. Finally, the system was fully integrated into the airborne platform and tested both indoor and in-flight. The Received Signal Strength Indication (RSSI and noise value in two typical application scenarios were recorded. The test results demonstrated the ability of this system to extend the communication range and build communication over obstacles. This system also shows the feasibility to coordinate multiple UAVs’ communication with the same relay structure.

  20. Three-dimensional kinematics of hummingbird flight.

    Science.gov (United States)

    Tobalske, Bret W; Warrick, Douglas R; Clark, Christopher J; Powers, Donald R; Hedrick, Tyson L; Hyder, Gabriel A; Biewener, Andrew A

    2007-07-01

    Hummingbirds are specialized for hovering flight, and substantial research has explored this behavior. Forward flight is also important to hummingbirds, but the manner in which they perform forward flight is not well documented. Previous research suggests that hummingbirds increase flight velocity by simultaneously tilting their body angle and stroke-plane angle of the wings, without varying wingbeat frequency and upstroke: downstroke span ratio. We hypothesized that other wing kinematics besides stroke-plane angle would vary in hummingbirds. To test this, we used synchronized high-speed (500 Hz) video cameras and measured the three-dimensional wing and body kinematics of rufous hummingbirds (Selasphorus rufus, 3 g, N=5) as they flew at velocities of 0-12 m s(-1) in a wind tunnel. Consistent with earlier research, the angles of the body and the stroke plane changed with velocity, and the effect of velocity on wingbeat frequency was not significant. However, hummingbirds significantly altered other wing kinematics including chord angle, angle of attack, anatomical stroke-plane angle relative to their body, percent of wingbeat in downstroke, wingbeat amplitude, angular velocity of the wing, wingspan at mid-downstroke, and span ratio of the wingtips and wrists. This variation in bird-centered kinematics led to significant effects of flight velocity on the angle of attack of the wing and the area and angles of the global stroke planes during downstroke and upstroke. We provide new evidence that the paths of the wingtips and wrists change gradually but consistently with velocity, as in other bird species that possess pointed wings. Although hummingbirds flex their wings slightly at the wrist during upstroke, their average wingtip-span ratio of 93% revealed that they have kinematically ;rigid' wings compared with other avian species.

  1. Visual Flight Control of a Quadrotor Using Bioinspired Motion Detector

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2012-01-01

    Full Text Available Motion detection in the fly is extremely fast with low computational requirements. Inspired from the fly's vision system, we focus on a real-time flight control on a miniquadrotor with fast visual feedback. In this work, an elaborated elementary motion detector (EMD is utilized to detect local optical flow. Combined with novel receptive field templates, the yaw rate of the quadrotor is estimated through a lookup table established with this bioinspired visual sensor. A closed-loop control system with the feedback of yaw rate estimated by EMD is designed. With the motion of the other degrees of freedom stabilized by a camera tracking system, the yaw-rate of the quadrotor during hovering is controlled based on EMD feedback under real-world scenario. The control performance of the proposed approach is compared with that of conventional approach. The experimental results demonstrate the effectiveness of utilizing EMD for quadrotor control.

  2. Generalized Proportional Integral Control for an Unmanned Quadrotor System

    Directory of Open Access Journals (Sweden)

    Antonio Fernández-Caballero

    2015-07-01

    Full Text Available In this article, a generalized proportional integral (GPI control approach is presented for regulation and trajectory tracking problems in a nonlinear, multivariable quadrotor system model. In the feedback control law, no asymptotic observers or time discretizations are needed in the feedback loop. The GPI controller guarantees the asymptotically and exponentially stable behaviour of the controlled quadrotor position and orientation, as well as the possibilities of carrying out trajectory tracking tasks. The simulation results presented in the paper show that the proposed method exhibits very good stabilization and tracking performance in the presence of atmospheric disturbances and noise measurements.

  3. A Framework for Collaborative Quadrotor - Ground Robot Missions

    Science.gov (United States)

    2011-12-01

    quadrotor. The Qbot is accessible through three different block sets: the Roomba block set to drive the 35 vehicle, the HIL block set to read from...1) The Roomba Initialize block located in the Simulink Library Browser, under QuaRC Targets / Devices / Third-Party / iRobot / Roomba

  4. Outperforming hummingbirds' load-lifting capability with a lightweight hummingbird-like flapping-wing mechanism.

    Science.gov (United States)

    Leys, Frederik; Reynaerts, Dominiek; Vandepitte, Dirk

    2016-08-15

    The stroke-cam flapping mechanism presented in this paper closely mimics the wing motion of a hovering Rufous hummingbird. It is the only lightweight hummingbird-sized flapping mechanism which generates a harmonic wing stroke with both a high flapping frequency and a large stroke amplitude. Experiments on a lightweight prototype of this stroke-cam mechanism on a 50 mm-long wing demonstrate that a harmonic stroke motion is generated with a peak-to-peak stroke amplitude of 175° at a flapping frequency of 40 Hz. It generated a mass lifting capability of 5.1 g, which is largely sufficient to lift the prototype's mass of 3.39 g and larger than the mass-lifting capability of a Rufous hummingbird. The motor mass of a hummingbird-like robot which drives the stroke-cam mechanism is considerably larger (about five times) than the muscle mass of a hummingbird with comparable load-lifting capability. This paper presents a flapping wing nano aerial vehicle which is designed to possess the same lift- and thrust-generating principles of the Rufous hummingbird. The application is indoor flight. We give an overview of the wing kinematics and some specifications which should be met to develop an artificial wing, and also describe the applications of these in the mechanism which has been developed in this work. © 2016. Published by The Company of Biologists Ltd.

  5. Attitude Control of Quad-rotor by Improving the Reliability of Multi-Sensor System

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Dong Hyeon; Chong, Kil To [Chon-bok National University, Jeonju (Korea, Republic of); Park, Jong Ho [Seonam University, Namwon (Korea, Republic of); Ryu, Ji Hyoung [ETRI, Daejeon (Korea, Republic of)

    2015-05-15

    This paper presents the results of study for improving the reliability of quadrotor attitude control by applying a multi-sensor along with a data fusion algorithm. First, a mathematical model of the quadrotor dynamics was developed. Then, using the quadrotor mathematical model, simulations were performed using the improved reliability multi-sensor data as the inputs. From the simulation results, we designed a Gimbal-equipped quadrotor system. With the quadrotor in a hover state, we performed experiments according to the angle change of the user's specifications . We then calculated the attitude control data from the actual experimental data. Furthermore, with additional simulations, we verified the performance of the designed quadrotor attitude control system with multiple sensors.

  6. UAV Antarctica

    OpenAIRE

    Dahl, David; Stetler, Fredrik

    2014-01-01

    One of the biggest problems of our time is the global warming. A direct result of this phenomena is the melting of ice of the glaciers on the north and the south pole. As this continues, the melted ice will contribute to an increase of the sea level, and may cause enormous natural disasters. To be able to prevent this, it’s important to study its affects. This reports contains a concept study of a Unmanned Aerial Vehicle, a UAV, set on the coast of Antarctica by the Australian owned base Davi...

  7. Study on High Accuracy Topographic Mapping via UAV-based Images

    Science.gov (United States)

    Chi, Yun-Yao; Lee, Ya-Fen; Tsai, Shang-En

    2016-10-01

    Unmanned aerial vehicle (UAV) provides a promising tool for the acquisition of such multi-temporal aerial stereo photos and high-resolution digital surface models. Recently, the flight of UAVs operates with high degrees of autonomy by the global position system and onboard digit camera and computer. The UAV-based mapping can be obtained faster and cheaper, but its accuracy is anxious. This paper aims to identify the integration ability of high accuracy topographic map via the image of quad-rotors UAV and ground control points (GCPs). The living survey data is collected in the Errn river basins area in Tainan, Taiwan. The high accuracy UAV-based topographic in the study area is calibrated by the local coordinate of GCPs using the total station with the accuracy less than 1/2000. The comparison results show the accuracy of UAV-based topographic is accepted by overlapping. The results can be a reference for the practice works of mapping survey in earth.

  8. Direct Self-Repairing Control for Quadrotor Helicopter Attitude Systems

    Directory of Open Access Journals (Sweden)

    Huiliao Yang

    2014-01-01

    Full Text Available A quadrotor helicopter with uncertain actuator faults, such as loss of effectiveness and lock-in-place, is studied in this paper. An adaptive fuzzy sliding mode controller based on direct self-repairing control is designed for such nonlinear system to track the desired output signal, when any actuator of this quadrotor helicopter is loss of effectiveness or stuck at some place. Moreover, using the Lyapunov stability theory, the stability of the whole system and the convergence of the tracking error can be guaranteed. Finally, the availability of the proposed method is verified by simulation on 3-DOF hover to ensure that the system performance under faulty conditions can be quickly recovered to its normal level. And this proposed method is also proved to be better than that of LQR through simulation.

  9. FUZZY-GENETIC CONTROL OF QUADROTOR UNMANNED AERIAL VEHICLES

    Directory of Open Access Journals (Sweden)

    Attila Nemes

    2016-03-01

    Full Text Available This article presents a novel fuzzy identification method for dynamic modelling of quadrotor unmanned aerial vehicles. The method is based on a special parameterization of the antecedent part of fuzzy systems that results in fuzzy-partitions for antecedents. This antecedent parameter representation method of fuzzy rules ensures upholding of predefined linguistic value ordering and ensures that fuzzy-partitions remain intact throughout an unconstrained hybrid evolutionary and gradient descent based optimization process. In the equations of motion the first order derivative component is calculated based on Christoffel symbols, the derivatives of fuzzy systems are used for modelling the Coriolis effects, gyroscopic and centrifugal terms. The non-linear parameters are subjected to an initial global evolutionary optimization scheme and fine tuning with gradient descent based local search. Simulation results of the proposed new quadrotor dynamic model identification method are promising.

  10. Adaptation in a plant-hummingbird association.

    Science.gov (United States)

    Temeles, Ethan J; Kress, W John

    2003-04-25

    Sexual dimorphism in bill morphology and body size of the Caribbean purple-throated carib hummingbird is associated with a reversal in floral dimorphism of its Heliconia food plants. This hummingbird is the sole pollinator of H. caribaea and H. bihai, with flowers of the former corresponding to the short, straight bills of males, the larger sex, and flowers of the latter corresponding to the long, curved bills of females. On St. Lucia, H. bihai compensates for the rarity of H. caribaea by evolving a second color morph with flowers that match the bills of males, whereas on Dominica, H. caribaea evolves a second color morph with flowers that match the bills of females. The nectar rewards of all Heliconia morphs are consistent with each sex's choice of the morph that corresponds to its bill morphology and energy requirements, supporting the hypothesis that feeding preferences have driven their coadaptation.

  11. Quadrotor helicopter for surface hydrological measurements

    Science.gov (United States)

    Pagano, C.; Tauro, F.; Porfiri, M.; Grimaldi, S.

    2013-12-01

    Surface hydrological measurements are typically performed through user-assisted and intrusive field methodologies which can be inadequate to monitor remote and extended areas. In this poster, we present the design and development of a quadrotor helicopter equipped with digital acquisition system and image calibration units for surface flow measurements. This custom-built aerial vehicle is engineered to be lightweight, low-cost, highly customizable, and stable to guarantee optimal image quality. Quadricopter stability guarantees minimal vibrations during image acquisition and, therefore, improved accuracy in flow velocity estimation through large scale particle image velocimetry algorithms or particle tracking procedures. Stability during the vehicle pitching and rolling is achieved by adopting large arm span and high-wing configurations. Further, the vehicle framework is composed of lightweight aluminum and durable carbon fiber for optimal resilience. The open source Ardupilot microcontroller is used for remote control of the quadricopter. The microcontroller includes an inertial measurement unit (IMU) equipped with accelerometers and gyroscopes for stable flight through feedback control. The vehicle is powered by a 3 cell (11.1V) 3000 mAh Lithium-polymer battery. Electronic equipment and wiring are hosted into the hollow arms and on several carbon fiber platforms in the waterproof fuselage. Four 35A high-torque motors are supported at the far end of each arm with 10 × 4.7 inch propellers. Energy dissipation during landing is accomplished by four pivoting legs that, through the use of shock absorbers, prevent the impact energy from affecting the frame thus causing significant damage. The data capturing system consists of a GoPro Hero3 camera and in-house built camera gimbal and shock absorber damping device. The camera gimbal, hosted below the vehicle fuselage, is engineered to maintain the orthogonality of the camera axis with respect to the water surface by

  12. Stabilization of a Quadrotor With Uncertain Suspended Load Using Sliding Mode Control

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xu; Liu, Rui; Zhang, Jiucai; Zhang, Xiaoli

    2016-08-21

    The stability and trajectory control of a quadrotor carrying a suspended load with a fixed known mass has been extensively studied in recent years. However, the load mass is not always known beforehand in practical applications. This mass uncertainty brings uncertain disturbances to the quadrotor system, causing existing controllers to have a worse performance or to be collapsed. To improve the quadrotor's stability in this situation, we investigate the impacts of the uncertain load mass on the quadrotor. By comparing the simulation results of two controllers -- the proportional-derivative (PD) controller and the sliding mode controller (SMC) driven by a sliding mode disturbance of observer (SMDO), the quadrotor's performance is verified to be worse as the uncertainty increases. The simulation results also show a controller with stronger robustness against disturbances is better for practical applications.

  13. Backstepping Controller with Intelligent Parameters Selection for Stabilization of Quadrotor Helicopter

    Directory of Open Access Journals (Sweden)

    Mohd Ariffanan Mohd Basri

    2016-07-01

    Full Text Available In this paper, the dynamic model of quadrotor helicopter has been mathematically formulated. Then, an intelligent backstepping controller (IBC is designed for the quadrotor altitude and attitude stabilization in the existence of external disturbances and measurement noise. The designed controller consists of a backstepping controller which can automatically select its parameters on-line by a fuzzy supervisory mechanism. The stability criterion for the stabilization of the quadrotor is proven by the Lyapunov theorem. Several numerical simulations using the dynamic model of a four degree of freedom (DOF quadrotor helicopter show the effectiveness of the approach. Besides, the simulation results indicate that the proposed design techniques can stabilize the quadrotor helicopter with better performance than established linear design techniques.

  14. Quad-Rotor Helicopter Autonomous Navigation Based on Vanishing Point Algorithm

    Directory of Open Access Journals (Sweden)

    Jialiang Wang

    2014-01-01

    Full Text Available Quad-rotor helicopter is becoming popular increasingly as they can well implement many flight missions in more challenging environments, with lower risk of damaging itself and its surroundings. They are employed in many applications, from military operations to civilian tasks. Quad-rotor helicopter autonomous navigation based on the vanishing point fast estimation (VPFE algorithm using clustering principle is implemented in this paper. For images collected by the camera of quad-rotor helicopter, the system executes the process of preprocessing of image, deleting noise interference, edge extracting using Canny operator, and extracting straight lines by randomized hough transformation (RHT method. Then system obtains the position of vanishing point and regards it as destination point and finally controls the autonomous navigation of the quad-rotor helicopter by continuous modification according to the calculated navigation error. The experimental results show that the quad-rotor helicopter can implement the destination navigation well in the indoor environment.

  15. Plant-hummingbird interactions in the West Indies: floral specialisation gradients associated with environment and hummingbird size.

    Science.gov (United States)

    Dalsgaard, Bo; Martín González, Ana M; Olesen, Jens M; Ollerton, Jeff; Timmermann, Allan; Andersen, Laila H; Tossas, Adrianne G

    2009-04-01

    Floral phenotype and pollination system of a plant may be influenced by the abiotic environment and the local pollinator assemblage. This was investigated in seven plant-hummingbird assemblages on the West Indian islands of Grenada, Dominica and Puerto Rico. We report all hummingbird and insect pollinators of 49 hummingbird-pollinated plant species, as well as six quantitative and semi-quantitative floral characters that determine visitor restriction, attraction and reward. Using nonmetric multidimensional scaling analysis, we show that hummingbird-pollinated plants in the West Indies separate in floral phenotypic space into two gradients-one associated with the abiotic environment and another with hummingbird size. Plants pollinated by large, long-billed hummingbirds had flowers with long corolla tube, large amounts of nectar and showy orange-red colouration. These attracted few or no insect species, whereas plants pollinated by small, short-billed hummingbirds were frequently pollinated by insects, particularly lepidopterans. The separation of plants related to environmental factors showed that species in the wet and cold highlands produced large amounts of dilute nectar, possessed no or a weak odour, and were associated with few insects, particularly few hymenopterans, compared to plants in the dry and warm lowlands. The most specialised hummingbird-pollinated plants are found in the West Indian highlands where they are pollinated by mainly large, long-billed hummingbirds. At the other extreme, highly generalised plants growing in the dry and warm lowlands are pollinated by small, short-billed hummingbirds and numerous insect species. This illustrates that, even within the hummingbird-pollinated flora, pollination syndrome and the degree of specialisation may vary tremendously depending on pollinator morphology and environment.

  16. Development and Validation of a Controlled Virtual Environment for Guidance, Navigation and Control of Quadrotor UAV

    Science.gov (United States)

    2013-09-01

    solving optimal control problems , a...approach for solving optimal control problems was that of indirect methods. However, the disadvantage associated with indirect methods is that the boundary...the adjoint equations, control equations and all the transversality conditions explicitly. Thus, solving optimal control problems using

  17. Integration of Control Algorithms for Quadrotor UAV’s Using an Indoor Sensor Environment

    Science.gov (United States)

    2011-09-01

    technology is its ability to penetrate through obstacles and propagate across long distances. In contrast, an optical localization system, such as...both the azimuth and elevation angles of the incoming UWB pulse from an energized tag and uses simple trigonometry to find a fix. The TDoA method is...ranges to an unknown object could then be used to calculate a projected path of the obstacle and a resulting collision avoidance maneuver. Figure

  18. 某四旋翼无人飞行器的力学仿真分析%Mechanical Simulation Analysis of a Quad-rotor Unmanned Aerial Vehicle

    Institute of Scientific and Technical Information of China (English)

    吴文志; 吴斌; 周星; 张平; 程林

    2016-01-01

    旋翼无人飞行器具有垂直起降/着陆、可悬停、机动性好及结构简单等多种优点,无论是在军事领域还是民用领域,都有非常广泛的应用价值。文中采用Abaqus建立了某四旋翼无人飞行器的力学仿真模型。基于所建立的力学仿真模型,分析了该无人飞行器在旋翼升力、风载荷和降落冲击等工况下结构的强度和刚度响应,得到了相应的变形和应力云图。计算结果表明,该旋翼飞行器的结构设计满足总体设计要求。%Rotor unmanned aerial vehicle ( UAV) has wide applications in military and civil fields due to its merits such as vertical taking off and landing, hovering ability, good maneuverability and simplified structure . In this paper the mechanical simulation model of a quad-rotor UAV is established .Based on the model , the strength and stiffness responses of the UAV structure under the conditions of rotor lift , wind load and landing impact are analyzed and the corresponding contours of deformation and stress are obtained .The results show that the structure design of this UAV satisfies the requirements of system design .

  19. Nonlinear control for an underactuated quadrotor unmanned aerial vehicle with parametric uncertainties%具有参数不确定性的欠驱动四旋翼无人飞行器的非线性控制器设计

    Institute of Scientific and Technical Information of China (English)

    刁琛; 鲜斌; 古训; 赵勃; 郭建川

    2012-01-01

    A new nonlinear tracking controller is presented for an underactuated quadrotor unmanned aerial vehicle(UAV)subjected to parametric uncertainties.A continuous nonlinear robust control design is combined with an on-line parameter estimation scheme to develop the control law.A Lyapunov based stability analysis is used to prove that asymptotic tracking of the quadrotor UAV's position and regulation of yaw orientation are achieved under parametric uncertainties.Compared with the sliding mode based control approaches,the proposed control design is free of chattering.Numerical simulation results of a 6 DOF quadrotor UAV model show that the proposed control strategy has good tracking performance.%针对具有参数不确定性的欠驱动四旋翼无人飞行器,设计了一种非线性飞行控制器.该控制器主要采用非线性鲁棒以及在线参数估计算法.利用基于李亚普诺夫稳定性分析方法,证明了这种控制器可以使四旋翼无人飞行器的x,y,z方向的位移跟踪参考轨迹,偏航角ψ稳定到任意点,并且达到全局最终稳定的控制效果.同时相对于一般的滑模控制算法,本文提出的控制器消除了颤振现象.数值仿真结果表明,本文提出的控制设计具有良好的控制效果.

  20. Force production of a hovering hummingbird

    Science.gov (United States)

    Luo, Haoxiang; Song, Jialei; Hedrick, Tyson

    2013-11-01

    A three-dimensional numerical study is performed for a hovering Ruby-throated hummingbird (Archilochus colubris) based on an immersed-boundary method. To accurately model the unsteady aerodynamics, realistic 3D wing kinematics is reconstructed from high-speed images of the wing motion filmed at 1000 frames per second, resulting in 25 frames per flapping cycle. A high-resolution grid is employed to resolve the vortices shed from the wing. The results are validated by comparing the spanwise vorticity and circulation with the previous PIV data and also by calculating the average lift. The force production shows significant asymmetry with the downstroke producing lift 2.6 times as high as the upstroke, despite a nearly horizontal stroke plane. The total power consumption is around 55 W/kg, which is twice of previous estimate. In this presentation, we will discuss several mechanisms that lead to the force asymmetry, including the drag-based lift and the leading-edge vortex behavior. We will also address the role of wing-wake interaction, which appears to be different for the hummingbird than some of the insects such as fruit flies. Supported by NSF (No. CBET-0954381).

  1. Modeling and Backstepping-based Nonlinear Control Strategy for a 6 DOF Quadrotor Helicopter

    Institute of Scientific and Technical Information of China (English)

    Ashfaq Ahmad Mian; Wang Daobo

    2008-01-01

    In this article,a nonlinear model of an underactuated six degrees of freedom (6 DOF) quadrotor helicopter is derived on the basis of the Newton-Euler formalism.The derivation comprises determining equations of the motion of the quadrotor in three dimensions andapproximating the actuation forces through the modeling of aerodynamic coefficients and electric motor dynamics.The derived modelcomposed of translatioual and rotational subsystems is dynamically unstable,so a sequential nonlinear control strategy is used.The con-trol strategy includes feedback linearization coupled with a PD controller for the translational subsystem and a backstepping-based PID nonlinear controller for the rotational subsystem of the quadrotor.The performances of the nonlinear control method are evaluated by nonlinear simulation and the results demonstrate the effectiveness of the proposed control strategy for the quadrotor helicopter inquasi-stationary flights.

  2. UAV path planning using artificial potential field method updated by optimal control theory

    Science.gov (United States)

    Chen, Yong-bo; Luo, Guan-chen; Mei, Yue-song; Yu, Jian-qiao; Su, Xiao-long

    2016-04-01

    The unmanned aerial vehicle (UAV) path planning problem is an important assignment in the UAV mission planning. Based on the artificial potential field (APF) UAV path planning method, it is reconstructed into the constrained optimisation problem by introducing an additional control force. The constrained optimisation problem is translated into the unconstrained optimisation problem with the help of slack variables in this paper. The functional optimisation method is applied to reform this problem into an optimal control problem. The whole transformation process is deduced in detail, based on a discrete UAV dynamic model. Then, the path planning problem is solved with the help of the optimal control method. The path following process based on the six degrees of freedom simulation model of the quadrotor helicopters is introduced to verify the practicability of this method. Finally, the simulation results show that the improved method is more effective in planning path. In the planning space, the length of the calculated path is shorter and smoother than that using traditional APF method. In addition, the improved method can solve the dead point problem effectively.

  3. Mini-quadrotor Attitude Control based on Hybrid Backstepping & Frenet-Serret Theory

    OpenAIRE

    Colorado Montaño, Julián; Barrientos Cruz, Antonio; Martínez Álvarez, Alexander; Lafaverges, B.; Pereira Valente, Joao Ricardo

    2010-01-01

    This paper is about modeling and control of miniature quadrotors, with a special emphasis on attitude control. Mathematical models for simulation and nonlinear control approaches are introduced and subsequently applied to commercial aircraft: the DraganFlyer quadrotor, which has been hardware-modified in order to perform experimental autonomous flying. Hybrid Backstepping control and the Frenet-Serret theory is used for attitude stabilization, introducing a desired attitude angle acceleration...

  4. Aerial monitoring in active mud volcano by UAV technique

    Science.gov (United States)

    Pisciotta, Antonino; Capasso, Giorgio; Madonia, Paolo

    2016-04-01

    UAV photogrammetry opens various new applications in the close range domain, combining aerial and terrestrial photogrammetry, but also introduces low-cost alternatives to the classical manned aerial photogrammetry. Between 2014 and 2015 tree aerial surveys have been carried out. Using a quadrotor drone, equipped with a compact camera, it was possible to generate high resolution elevation models and orthoimages of The "Salinelle", an active mud volcanoes area, located in territory of Paternò (South Italy). The main risks are related to the damages produced by paroxysmal events. Mud volcanoes show different cyclic phases of activity, including catastrophic events and periods of relative quiescence characterized by moderate activity. Ejected materials often are a mud slurry of fine solids suspended in liquids which may include water and hydrocarbon fluids, the bulk of released gases are carbon dioxide, with some methane and nitrogen, usually pond-shaped of variable dimension (from centimeters to meters in diameter). The scope of the presented work is the performance evaluation of a UAV system that was built to rapidly and autonomously acquire mobile three-dimensional (3D) mapping data in a volcanic monitoring scenario.

  5. Flight Performance and Competitive Displacement of Hummingbirds across Elevational Gradients

    OpenAIRE

    Altshuler, Douglas L.

    2006-01-01

    Hummingbirds, with their impressive flight ability and competitive aerial contests, make ideal candidates for applying a mechanistic approach to studying community structure. Because flight costs are influenced by abiotic factors that change systematically with altitude, elevational gradients provide natural experiments for hummingbird flight ecology. Prior attempts relied on wing disc loading (WDL) as a morphological surrogate for flight performance, but recent analyses indicate this variabl...

  6. Development of a Quadrotor Test Bed — Modelling, Parameter Identification, Controller Design and Trajectory Generation

    Directory of Open Access Journals (Sweden)

    Wei Dong

    2015-02-01

    Full Text Available In this paper, a quadrotor test bed is developed. The technical approach for this test bed is firstly proposed by utilizing a commercial quadrotor, a Vicon motion capture system and a ground station. Then, the mathematical model of the quadrotor is formulated considering aerodynamic effects, and the parameter identification approaches for this model are provided accordingly. Based on the developed model and identified parameters, a simulation environment that is consistent with the real system is developed. Subsequently, a flight control strategy and a trajectory generation method, both of which are conceptually and computationally lightweight, are developed and tested in the simulation environment. The developed algorithms are then directly transplanted to the real system, and the experimental results show that their responses in the real-time flights match well with those from the simulations. This indicates that the control algorithms developed for the quadrotor can be preliminarily verified and refined though simulations, and then directly implemented to the real system, which could significantly reduce the experimental risks and costs. Meanwhile, real-time experiments show that the developed flight controller can efficiently stabilize the quadrotor when external disturbances exist, and the trajectory generation approach can provide safe guidance for the quadrotor to fly smoothly through cluttered environments with obstacle rings. All of these features are valuable for real applications, thus demonstrating the feasibility of further development.

  7. Development of a Quadrotor Test Bed — Modelling, Parameter Identification, Controller Design and Trajectory Generation

    Directory of Open Access Journals (Sweden)

    Wei Dong

    2015-02-01

    Full Text Available In this paper, a quadrotor test bed is developed. The technical approach for this test bed is firstly proposed by utilizing a commercial quadrotor, a Vicon motion capture system and a ground station. Then, the mathematical model of the quadrotor is formulated considering aerodynamic effects, and the parameter identification approaches for this model are provided accordingly. Based on the developed model and identified parameters, a simulation environment that is consistent with the real system is developed. Subsequently, a flight control strategy and a trajectory generation method, both of which are conceptually and computationally lightweight, are developed and tested in the simulation environment. The developed algorithms are then directly transplanted to the real system, and the experimental results show that their responses in the real-time flights match well with those from the simulations. This indicates that the control algorithms developed for the quadrotor can be preliminarily verified and refined though simulations, and then directly implemented to the real system, which could significantly reduce the experimental risks and costs. Meanwhile, real-time experiments show that the developed flight controller can efficiently stabilize the quadrotor when external disturbances exist, and the trajectory generation approach can provide safe guidance for the quadrotor to fly smoothly through cluttered environments with obstacle rings. All of these features are valuable for real applications, thus demonstrating the feasibility of further development.

  8. Robust UAV Mission Planning

    NARCIS (Netherlands)

    Evers, L.; Dollevoet, T; Barros, A.I.; Monsuur, H.

    2011-01-01

    Unmanned Aerial Vehicles (UAVs) can provide significant contributions to information gathering in military missions. UAVs can be used to capture both full motion video and still imagery of specific target locations within the area of interest. In order to improve the effectiveness of a reconnaissanc

  9. Robust UAV mission planning

    NARCIS (Netherlands)

    Evers, L.; Dollevoet, T.; Barros, A.I.; Monsuur, H.

    2011-01-01

    Unmanned Areal Vehicles (UAVs) can provide significant contributions to information gathering in military missions. UAVs can be used to capture both full motion video and still imagery of specific target locations within the area of interest. In order to improve the effectiveness of a reconnaissance

  10. Robust UAV Mission Planning

    NARCIS (Netherlands)

    L. Evers (Lanah); T.A.B. Dollevoet (Twan); A.I. Barros (Ana); H. Monsuur (Herman)

    2011-01-01

    textabstractUnmanned Areal Vehicles (UAVs) can provide significant contributions to information gathering in military missions. UAVs can be used to capture both full motion video and still imagery of specific target locations within the area of interest. In order to improve the effectiveness of a re

  11. Robust UAV Mission Planning

    NARCIS (Netherlands)

    Evers, L.; Dollevoet, T.; Barros, A.I.; Monsuur, H.

    2014-01-01

    Unmanned Aerial Vehicles (UAVs) can provide significant contributions to information gathering in military missions. UAVs can be used to capture both full motion video and still imagery of specific target locations within the area of interest. In order to improve the effectiveness of a reconnaissanc

  12. Phylogenetic structure in tropical hummingbird communities

    DEFF Research Database (Denmark)

    Graham, Catherine H; Parra, Juan L; Rahbek, Carsten;

    2009-01-01

    composition of 189 hummingbird communities in Ecuador. We assessed how species and phylogenetic composition changed along environmental gradients and across biogeographic barriers. We show that humid, low-elevation communities are phylogenetically overdispersed (coexistence of distant relatives), a pattern...... an expensive means of locomotion at high elevations. We found that communities in the lowlands on opposite sides of the Andes tend to be phylogenetically similar despite their large differences in species composition, a pattern implicating the Andes as an important dispersal barrier. In contrast, along...... the steep environmental gradient between the lowlands and the Andes we found evidence that species turnover is comprised of relatively distantly related species. The integration of local and regional patterns of diversity across environmental gradients and biogeographic barriers provides insight...

  13. Molecular phylogenetics of the hummingbird genus Coeligena.

    Science.gov (United States)

    Parra, Juan Luis; Remsen, J V; Alvarez-Rebolledo, Mauricio; McGuire, Jimmy A

    2009-11-01

    Advances in the understanding of biological radiations along tropical mountains depend on the knowledge of phylogenetic relationships among species. Here we present a species-level molecular phylogeny based on a multilocus dataset for the Andean hummingbird genus Coeligena. We compare this phylogeny to previous hypotheses of evolutionary relationships and use it as a framework to understand patterns in the evolution of sexual dichromatism and in the biogeography of speciation within the Andes. Previous phylogenetic hypotheses based mostly on similarities in coloration conflicted with our molecular phylogeny, emphasizing the unreliability of color characters for phylogenetic inference. Two major clades, one monochromatic and the other dichromatic, were found in Coeligena. Closely related species were either allopatric or parapatric on opposite mountain slopes. No sister lineages replaced each other along an elevational gradient. Our results indicate the importance of geographic isolation for speciation in this group and the potential interaction between isolation and sexual selection to promote diversification.

  14. Hummingbird conservation: discovering diversity patterns in southwest U.S.A.

    Science.gov (United States)

    Susan M. Wethington; George C. West; Barbara A. Carlson

    2005-01-01

    Using data obtained in 2002 and 2003 from sites in the Hummingbird Monitoring Network, we investigated the effect of geographic factors—latitude, longitude, and elevation—and year on hummingbird diversity patterns in Southwestern U.S.A. In California, none of these factors affected hummingbird richness but elevation significantly affected abundance. In southeastern...

  15. Field Flight Dynamics of Hummingbirds during Territory Encroachment and Defense.

    Science.gov (United States)

    Sholtis, Katherine M; Shelton, Ryan M; Hedrick, Tyson L

    2015-01-01

    Hummingbirds are known to defend food resources such as nectar sources from encroachment by competitors (including conspecifics). These competitive intraspecific interactions provide an opportunity to quantify the biomechanics of hummingbird flight performance during ecologically relevant natural behavior. We recorded the three-dimensional flight trajectories of Ruby-throated Hummingbirds defending, being chased from and freely departing from a feeder. These trajectories allowed us to compare natural flight performance to earlier laboratory measurements of maximum flight speed, aerodynamic force generation and power estimates. During field observation, hummingbirds rarely approached the maximal flight speeds previously reported from wind tunnel tests and never did so during level flight. However, the accelerations and rates of change in kinetic and potential energy we recorded indicate that these hummingbirds likely operated near the maximum of their flight force and metabolic power capabilities during these competitive interactions. Furthermore, although birds departing from the feeder while chased did so faster than freely-departing birds, these speed gains were accomplished by modulating kinetic and potential energy gains (or losses) rather than increasing overall power output, essentially trading altitude for speed during their evasive maneuver. Finally, the trajectories of defending birds were directed toward the position of the encroaching bird rather than the feeder.

  16. Into rude air: hummingbird flight performance in variable aerial environments.

    Science.gov (United States)

    Ortega-Jimenez, V M; Badger, M; Wang, H; Dudley, R

    2016-09-26

    Hummingbirds are well known for their ability to sustain hovering flight, but many other remarkable features of manoeuvrability characterize the more than 330 species of trochilid. Most research on hummingbird flight has been focused on either forward flight or hovering in otherwise non-perturbed air. In nature, however, hummingbirds fly through and must compensate for substantial environmental perturbation, including heavy rain, unpredictable updraughts and turbulent eddies. Here, we review recent studies on hummingbirds flying within challenging aerial environments, and discuss both the direct and indirect effects of unsteady environmental flows such as rain and von Kármán vortex streets. Both perturbation intensity and the spatio-temporal scale of disturbance (expressed with respect to characteristic body size) will influence mechanical responses of volant taxa. Most features of hummingbird manoeuvrability remain undescribed, as do evolutionary patterns of flight-related adaptation within the lineage. Trochilid flight performance under natural conditions far exceeds that of microair vehicles at similar scales, and the group as a whole presents many research opportunities for understanding aerial manoeuvrability.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'.

  17. Field Flight Dynamics of Hummingbirds during Territory Encroachment and Defense.

    Directory of Open Access Journals (Sweden)

    Katherine M Sholtis

    Full Text Available Hummingbirds are known to defend food resources such as nectar sources from encroachment by competitors (including conspecifics. These competitive intraspecific interactions provide an opportunity to quantify the biomechanics of hummingbird flight performance during ecologically relevant natural behavior. We recorded the three-dimensional flight trajectories of Ruby-throated Hummingbirds defending, being chased from and freely departing from a feeder. These trajectories allowed us to compare natural flight performance to earlier laboratory measurements of maximum flight speed, aerodynamic force generation and power estimates. During field observation, hummingbirds rarely approached the maximal flight speeds previously reported from wind tunnel tests and never did so during level flight. However, the accelerations and rates of change in kinetic and potential energy we recorded indicate that these hummingbirds likely operated near the maximum of their flight force and metabolic power capabilities during these competitive interactions. Furthermore, although birds departing from the feeder while chased did so faster than freely-departing birds, these speed gains were accomplished by modulating kinetic and potential energy gains (or losses rather than increasing overall power output, essentially trading altitude for speed during their evasive maneuver. Finally, the trajectories of defending birds were directed toward the position of the encroaching bird rather than the feeder.

  18. Stabilization and trajectory tracking control for underactuated quadrotor helicopter subject to wind-gust disturbance

    Indian Academy of Sciences (India)

    Mohd Ariffanan Mohd Basri; Abdul Rashid Husain; Kumeresan A Danapalasingam

    2015-08-01

    The control of quadrotor helicopter has been a great challenge for control engineers and researchers since quadrotor is an underactuated and a highly unstable nonlinear system. In this paper, the dynamic model of quadrotor has been derived and a so-called robust optimal backstepping control (ROBC) is designed to address its stabilization and trajectory tracking problem in the existence of external disturbances. The robust controller is achieved by incorporating a prior designed optimal backstepping control (OBC) with a switching function. The control law design utilizes the switching function in order to attenuate the effects caused by external disturbances. In order to eliminate the chattering phenomenon, the sign function is replaced by the saturation function. A new heuristic algorithm namely Gravitational Search Algorithm (GSA) has been employed in designing the OBC. The proposed method is evaluated on a quadrotor simulation environment to demonstrate the effectiveness and merits of the theoretical development. Simulation results show that the proposed ROBC scheme can achieve favorable control performances compared to the OBC for autonomous quadrotor helicopter in the presence of external disturbances.

  19. Development of a bio-inspired UAV perching system

    Science.gov (United States)

    Xie, Pu

    autonomous perching system, the following objectives were included for this project. The statics model was derived through both quasi-static and analytical method. The grasping stable condition and grasping target of the mechanical gripper were studied through the static analysis. Furthermore, the contact behavior between each foot and the perched object was modeled and evaluated on SimMechanics based on the contact force model derived through virtual principle. The kinematics modeling of UAV perching system was governed with Euler angles and quaternions. Also the propulsion model of the brushless motors was introduced and calibrated. In addition, the flight dynamics model of the UAV system was developed for simulation-based analysis prior to developing a hardware prototype and flight experiment. A special inertial measurement unit (IMU) was designed which has the capability of indirectly calculating the angular acceleration from the angular velocity and the linear acceleration readings. Moreover, a commercial-of-the-shelf (COTS) autopilot-APM 2.6 was selected for the autonomous flight control of the quadrotor. The APM 2.6 is a complete open source autopilot system, which allows the user to turn any fixed, rotary wing or multi-rotor vehicle into a fully autonomous vehicle and capable of performing programmed GPS missions with pre-programed waypoints. In addition, algorithms for inverted pendulum control and autonomous perching control was introduced. The proportion-integrate-differential (PID) controller was used for the simplified UAV perching with inverted pendulum model for horizontal balance. The performance of the controller was verified through both simulation and experiment. In addition, for the purpose of achieving the autonomous perching, guidance and control algorithms were developed the UAV perching system. For guidance, the desired flight trajectory was developed based on a bio-behavioral tau theory which was established from studying the natural motion patterns

  20. Sugar Metabolism in Hummingbirds and Nectar Bats

    Directory of Open Access Journals (Sweden)

    Raul K. Suarez

    2017-07-01

    Full Text Available Hummingbirds and nectar bats coevolved with the plants they visit to feed on floral nectars rich in sugars. The extremely high metabolic costs imposed by small size and hovering flight in combination with reliance upon sugars as their main source of dietary calories resulted in convergent evolution of a suite of structural and functional traits. These allow high rates of aerobic energy metabolism in the flight muscles, fueled almost entirely by the oxidation of dietary sugars, during flight. High intestinal sucrase activities enable high rates of sucrose hydrolysis. Intestinal absorption of glucose and fructose occurs mainly through a paracellular pathway. In the fasted state, energy metabolism during flight relies on the oxidation of fat synthesized from previously-ingested sugar. During repeated bouts of hover-feeding, the enhanced digestive capacities, in combination with high capacities for sugar transport and oxidation in the flight muscles, allow the operation of the “sugar oxidation cascade”, the pathway by which dietary sugars are directly oxidized by flight muscles during exercise. It is suggested that the potentially harmful effects of nectar diets are prevented by locomotory exercise, just as in human hunter-gatherers who consume large quantities of honey.

  1. Simple adaptive control system design for a quadrotor with an internal PFC

    Energy Technology Data Exchange (ETDEWEB)

    Mizumoto, Ikuro; Nakamura, Takuto; Kumon, Makoto; Takagi, Taro [Dept. of Mechanical Systems Engineering, Kumamoto University 2-39-1 Kurokami, Kumamoto, 860-8555 (Japan)

    2014-12-10

    The paper deals with an adaptive control system design problem for a four rotor helicopter or quadrotor. A simple adaptive control design scheme with a parallel feedforward compensator (PFC) in the internal loop of the considered quadrotor will be proposed based on the backstepping strategy. As is well known, the backstepping control strategy is one of the advanced control strategy for nonlinear systems. However, the control algorithm will become complex if the system has higher order relative degrees. We will show that one can skip some design steps of the backstepping method by introducing a PFC in the inner loop of the considered quadrotor, so that the structure of the obtained controller will be simplified and a high gain based adaptive feedback control system will be designed. The effectiveness of the proposed method will be confirmed through numerical simulations.

  2. Design and implementation of a vision-based hovering and feature tracking algorithm for a quadrotor

    Science.gov (United States)

    Lee, Y. H.; Chahl, J. S.

    2016-10-01

    This paper demonstrates an approach to the vision-based control of the unmanned quadrotors for hover and object tracking. The algorithms used the Speed Up Robust Features (SURF) algorithm to detect objects. The pose of the object in the image was then calculated in order to pass the pose information to the flight controller. Finally, the flight controller steered the quadrotor to approach the object based on the calculated pose data. The above processes was run using standard onboard resources found in the 3DR Solo quadrotor in an embedded computing environment. The obtained results showed that the algorithm behaved well during its missions, tracking and hovering, although there were significant latencies due to low CPU performance of the onboard image processing system.

  3. Simulation of UAV Systems

    Directory of Open Access Journals (Sweden)

    P. Kaňovský

    2005-01-01

    Full Text Available The study described in this paper deals with the issue of a design tool for the autopilot of an Unmanned Aerial Vehicle (UAV and the selection of the airdata and inertial system sensors. This project was processed in cooperation with VTUL a PVO o.z. [1]. The feature that distinguishes the autopilot requirements of a UAV (Figs. 1, 7, 8 from the flight systems of conventional manned aircraft is the paradox of controlling a high bandwidth dynamical system using sensors that are in harmony with the low cost low weight objectives that UAV designs are often expected to achieve. The principal function of the autopilot is flight stability, which establishes the UAV as a stable airborne platform that can operate at a precisely defined height. The main sensor for providing this height information is a barometric altimeter. The solution to the UAV autopilot design was realised with simulations using the facilities of Matlab® and in particular Simulink®[2]. 

  4. Flight mechanics and control of escape manoeuvres in hummingbirds. I. Flight kinematics.

    Science.gov (United States)

    Cheng, Bo; Tobalske, Bret W; Powers, Donald R; Hedrick, Tyson L; Wethington, Susan M; Chiu, George T C; Deng, Xinyan

    2016-11-15

    Hummingbirds are nature's masters of aerobatic manoeuvres. Previous research shows that hummingbirds and insects converged evolutionarily upon similar aerodynamic mechanisms and kinematics in hovering. Herein, we use three-dimensional kinematic data to begin to test for similar convergence of kinematics used for escape flight and to explore the effects of body size upon manoeuvring. We studied four hummingbird species in North America including two large species (magnificent hummingbird, Eugenes fulgens, 7.8 g, and blue-throated hummingbird, Lampornis clemenciae, 8.0 g) and two smaller species (broad-billed hummingbird, Cynanthus latirostris, 3.4 g, and black-chinned hummingbirds Archilochus alexandri, 3.1 g). Starting from a steady hover, hummingbirds consistently manoeuvred away from perceived threats using a drastic escape response that featured body pitch and roll rotations coupled with a large linear acceleration. Hummingbirds changed their flapping frequency and wing trajectory in all three degrees of freedom on a stroke-by-stroke basis, likely causing rapid and significant alteration of the magnitude and direction of aerodynamic forces. Thus it appears that the flight control of hummingbirds does not obey the 'helicopter model' that is valid for similar escape manoeuvres in fruit flies. Except for broad-billed hummingbirds, the hummingbirds had faster reaction times than those reported for visual feedback control in insects. The two larger hummingbird species performed pitch rotations and global-yaw turns with considerably larger magnitude than the smaller species, but roll rates and cumulative roll angles were similar among the four species. © 2016. Published by The Company of Biologists Ltd.

  5. Premigratory fat metabolism in hummingbirds: A rumsfeldian approach

    Directory of Open Access Journals (Sweden)

    Raul K. SUAREZ

    2013-06-01

    Full Text Available Hummingbird migration is a remarkable feat, given the small body sizes of migratory species, their high metabolic rates during flight and the long distances traveled using fat to fuel the effort. Equally remarkable is the ability of premigratory hummingbirds in the wild to accumulate fat, synthesized from sugar, at rates as high as 10% of body mass per day. This paper summarizes, using Rumsfeldian terminology, “known knowns” concerning the energetics of hummingbird migration and premigratory fattening. Energy metabolism during hover-feeding on floral nectar is fueled directly by dietary sugar through the pathway recently named the “sugar oxidation cascade”. However, flight without feeding for more than a few minutes requires shifting to fat as a fuel. It is proposed that behavior and metabolic fuel choice are coadapted to maximize the rate of fat deposition during premigratory fattening. The hummingbird liver appears to possess extraordinarily high capacities for fatty acid synthesis. The analysis of “known knowns” leads to identification of “known unknowns”, e.g., the fates of dietary glucose and fructose, the regulation of fat metabolism and metabolic interactions between liver and adipose tissue. The history of science behooves recognition of “unknown unknowns” that, when discovered serendipitously, might shed new light on fundamental mechanisms as well as human pathological conditions [Current Zoology 59 (3: 371–380, 2013].

  6. The macroecology of phylogenetically structured hummingbird-plant networks

    DEFF Research Database (Denmark)

    Gonzalez, Ana M. Martin; Dalsgaard, Bo; Nogues, David Bravo

    2015-01-01

    ° N–32° S), ranging from sea level to c. 3700 m a.s.l., located on the mainland and on islands and covering a wide range of climate regimes. Methods We measured the level of specialization and modularity in mutualistic plant–hummingbird interaction networks. Using an ordinary least squares multimodel...

  7. Premigratory fat metabolism in hummingbirds:A Rumsfeldian approach

    Institute of Scientific and Technical Information of China (English)

    Raul K.SUAREZ

    2013-01-01

    Hummingbird migration is a remarkable feat,given the small body sizes of migratory species,their high metabolic rates during flight and the long distances traveled using fat to fuel the effort.Equally remarkable is the ability of premigratory hummingbirds in the wild to accumulate fat,synthesized from sugar,at rates as high as 10% of body mass per day.This paper summarizes,using Rumsfeldian terminology,“known knowns” concerning the energetics of hummingbird migration and premigratory fattening.Energy metabolism during hover-feeding on floral nectar is fueled directly by dietary sugar through the path-way recently named the “sugar oxidation cascade”.However,flight without feeding for more than a few minutes requires shifting to fat as a fuel.It is proposed that behavior and metabolic fuel choice are coadapted to maximize the rate of fat deposition during premigratory fattening.The hummingbird liver appears to possess extraordinarily high capacities for fatty acid synthesis.The analysis of “known knowns” leads to identification of “known unknowns”,e.g.,the fates of dietary glucose and fructose,the regulation of fat metabolism and metabolic interactions between liver and adipose tissue.The history of science behooves recognition of“unknown unknowns” that,when discovered serendipitously,might shed new light on fundamental mechanisms as well as human pathological conditions.

  8. Hummingbird: Ultra-Lightweight Cryptography for Resource-Constrained Devices

    Science.gov (United States)

    Engels, Daniel; Fan, Xinxin; Gong, Guang; Hu, Honggang; Smith, Eric M.

    Due to the tight cost and constrained resources of high-volume consumer devices such as RFID tags, smart cards and wireless sensor nodes, it is desirable to employ lightweight and specialized cryptographic primitives for many security applications. Motivated by the design of the well-known Enigma machine, we present a novel ultra-lightweight cryptographic algorithm, referred to as Hummingbird, for resource-constrained devices in this paper. Hummingbird can provide the designed security with small block size and is resistant to the most common attacks such as linear and differential cryptanalysis. Furthermore, we also present efficient software implementation of Hummingbird on the 8-bit microcontroller ATmega128L from Atmel and the 16-bit microcontroller MSP430 from Texas Instruments, respectively. Our experimental results show that after a system initialization phase Hummingbird can achieve up to 147 and 4.7 times faster throughput for a size-optimized and a speed-optimized implementations, respectively, when compared to the state-of-the-art ultra-lightweight block cipher PRESENT[10] on the similar platforms.

  9. Flight performance and competitive displacement of hummingbirds across elevational gradients.

    Science.gov (United States)

    Altshuler, Douglas L

    2006-02-01

    Hummingbirds, with their impressive flight ability and competitive aerial contests, make ideal candidates for applying a mechanistic approach to studying community structure. Because flight costs are influenced by abiotic factors that change systematically with altitude, elevational gradients provide natural experiments for hummingbird flight ecology. Prior attempts relied on wing disc loading (WDL) as a morphological surrogate for flight performance, but recent analyses indicate this variable does not influence either territorial behavior or competitive ability. Aerodynamic power, by contrast, can be derived from direct measurements of performance and, like WDL, declines across elevations. Here, I demonstrate for a diverse community of Andean hummingbirds that burst aerodynamic power is associated with territorial behavior. Along a second elevational gradient in Colorado, I tested for correlated changes in aerodynamic power and competitive ability in two territorial hummingbirds. This behavioral analysis revealed that short-winged Selasphorus rufus males are dominant over long-winged Selasphorus platycercus males at low elevations but that the roles are reversed at higher elevations. Several lines of evidence support the hypothesis that the burst rather than sustained aerodynamic performance mediates competitive ability at high elevation. A minimum value for burst power may be required for successful competition, but other maneuverability features gain importance when all competitors have sufficient muscle power, as occurs at low elevations.

  10. Introduction to UAV systems

    CERN Document Server

    Fahlstrom, Paul

    2012-01-01

    Unmanned aerial vehicles (UAVs) have been widely adopted in the military world over the last decade and the success of these military applications is increasingly driving efforts to establish unmanned aircraft in non-military roles. Introduction to UAV Systems, 4th edition provides a comprehensive introduction to all of the elements of a complete Unmanned Aircraft System (UAS). It addresses the air vehicle, mission planning and control, several types of mission payloads, data links and how they interact with mission performance, and launch and recovery concepts. This

  11. Relating form to function in the hummingbird feeding apparatus

    Directory of Open Access Journals (Sweden)

    Alejandro Rico-Guevara

    2017-06-01

    Full Text Available A complete understanding of the feeding structures is fundamental in order to study how animals survive. Some birds use long and protrusible tongues as the main tool to collect their central caloric source (e.g., woodpeckers and nectarivores. Hummingbirds are the oldest and most diverse clade of nectarivorous vertebrates, being a perfect subject to study tongue specializations. Their tongue functions to intraorally transport arthropods through their long bills and enables them to exploit the nectarivorous niche by collecting small amounts of liquid, therefore it is of vital importance to study its anatomy and structure at various scales. I focused on the portions of the hummingbird tongue that have been shown to be key for understanding their feeding mechanisms. I used histology, transmission and scanning electron microscopy, microCT, and ex-vivo experiments in order to advance the comprehension of the morphology and functioning of the hummingbird feeding apparatus. I found that hummingbird tongues are composed mainly of thin cornified epithelium, lack papillae, and completely fill the internal cast of the rostral oropharyngeal cavity. Understanding this puzzle-piece match between bill and tongue will be essential for the study of intraoral transport of nectar. Likewise, I found that the structural composition and tissue architecture of the tongue groove walls provide the rostral portion of the tongue with elastic properties that are central to the study of tongue-nectar interactions during the feeding process. Detailed studies on hummingbirds set the basis for comparisons with other nectar-feeding birds and contribute to comprehend the natural solutions to collecting liquids in the most efficient way possible.

  12. The effects of atmospheric turbulence on a quadrotor heavy lift airship

    Science.gov (United States)

    Tischler, M. B.; Jex, H. R.

    1982-01-01

    The response of a quadrotor heavy lift airship to atmospheric turbulence is evaluated using a four-point input model. Results show interaction between gust inputs and the characteristic modes of the vehicle's response. Example loop closures demonstrate tradeoffs between response regulation and structural loads. Vehicle responses to a tuned discrete wave front compare favorably with the linear results and illustrate characteristic HLA motion.

  13. Path planning of decentralized multi-quadrotor based on fuzzy-cell decomposition algorithm

    Science.gov (United States)

    Iswanto, Wahyunggoro, Oyas; Cahyadi, Adha Imam

    2017-04-01

    The paper aims to present a design algorithm for multi quadrotor lanes in order to move towards the goal quickly and avoid obstacles in an area with obstacles. There are several problems in path planning including how to get to the goal position quickly and avoid static and dynamic obstacles. To overcome the problem, therefore, the paper presents fuzzy logic algorithm and fuzzy cell decomposition algorithm. Fuzzy logic algorithm is one of the artificial intelligence algorithms which can be applied to robot path planning that is able to detect static and dynamic obstacles. Cell decomposition algorithm is an algorithm of graph theory used to make a robot path map. By using the two algorithms the robot is able to get to the goal position and avoid obstacles but it takes a considerable time because they are able to find the shortest path. Therefore, this paper describes a modification of the algorithms by adding a potential field algorithm used to provide weight values on the map applied for each quadrotor by using decentralized controlled, so that the quadrotor is able to move to the goal position quickly by finding the shortest path. The simulations conducted have shown that multi-quadrotor can avoid various obstacles and find the shortest path by using the proposed algorithms.

  14. Decentralized PID neural network control for a quadrotor helicopter subjected to wind disturbance

    Institute of Scientific and Technical Information of China (English)

    陈彦民; 何勇灵; 周岷峰

    2015-01-01

    A decentralized PID neural network (PIDNN) control scheme was proposed to a quadrotor helicopter subjected to wind disturbance. First, the dynamic model that considered the effect of wind disturbance was established via Newton−Euler formalism. For quadrotor helicopter flying at low altitude in actual situation, it was more susceptible to be influenced by the turbulent wind field. Therefore, the turbulent wind field was generated according to Dryden model and taken into consideration as the disturbance source of quadrotor helicopter. Then, a nested loop control approach was proposed for the stabilization and navigation problems of the quadrotor subjected to wind disturbance. A decentralized PIDNN controller was designed for the inner loop to stabilize the attitude angle. A conventional PID controller was used for the outer loop in order to generate the reference path to inner loop. Moreover, the connective weights of the PIDNN were trained on-line by error back-propagation method. Furthermore, the initial connective weights were identified according to the principle of PID control theory and the appropriate learning rate was selected by discrete Lyapunov theory in order to ensure the stability. Finally, the simulation results demonstrate that the controller can effectively resist external wind disturbances, and presents good stability, maneuverability and robustness.

  15. Miniature UAVs : An overview

    NARCIS (Netherlands)

    Weimar, P.W.L.; Kerkkamp, J.S.F.; Wiel, R.A.N.; Meiller, P.P.; Bos, J.G.H.

    2014-01-01

    With this book TNO provides an overview of topics related to Miniature Unmanned Aerial Vehicles (MUAVs). Both novices and experts may find this publication valuable. The Netherlands Organisation for Applied Scientific Research TNO conducts research on UAVs and MUAVs, see for example [1], on the basi

  16. Online UAV Mission Planning

    NARCIS (Netherlands)

    Evers, L.; Barros, A.I.; Monsuur, H.; Wagelmans, A.P.M.

    2014-01-01

    Unmanned Aerial Vehicles (UAVs) have become an essential asset for military and law enforcement operations. In particular their use for surveillance and reconnaissance tasks has been growing due to the quick developments in the areal systems themselves, sensor technology, and image processing techni

  17. Online UAV Mission Planning

    NARCIS (Netherlands)

    Evers, L.; Barros, A.I.; Monsuur, H.; Wagelmans, A.P.M.

    2014-01-01

    Unmanned Aerial Vehicles (UAVs) have become an essential asset for military and law enforcement operations. In particular their use for surveillance and reconnaissance tasks has been growing due to the quick developments in the areal systems themselves, sensor technology, and image processing

  18. Online UAV Mission Planning

    NARCIS (Netherlands)

    Evers, L.; Barros, A.I.; Monsuur, H.; Wagelmans, A.P.M.

    2014-01-01

    Unmanned Aerial Vehicles (UAVs) have become an essential asset for military and law enforcement operations. In particular their use for surveillance and reconnaissance tasks has been growing due to the quick developments in the areal systems themselves, sensor technology, and image processing techni

  19. Adipose energy stores, physical work, and the metabolic syndrome: lessons from hummingbirds

    OpenAIRE

    Hargrove James L

    2005-01-01

    Abstract Hummingbirds and other nectar-feeding, migratory birds possess unusual adaptive traits that offer important lessons concerning obesity, diabetes and the metabolic syndrome. Hummingbirds consume a high sugar diet and have fasting glucose levels that would be severely hyperglycemic in humans, yet these nectar-fed birds recover most glucose that is filtered into the urine. Hummingbirds accumulate over 40% body fat shortly before migrations in the spring and autumn. Despite hyperglycemia...

  20. Pollination syndromes ignored: importance of non-ornithophilous flowers to Neotropical savanna hummingbirds

    Science.gov (United States)

    Maruyama, Pietro K.; Oliveira, Genilda M.; Ferreira, Carolina; Dalsgaard, Bo; Oliveira, Paulo E.

    2013-11-01

    Generalization prevails in flower-animal interactions, and although animal visitors are not equally effective pollinators, most interactions likely represent an important energy intake for the animal visitor. Hummingbirds are nectar-feeding specialists, and many tropical plants are specialized toward hummingbird-pollination. In spite of this, especially in dry and seasonal tropical habitats, hummingbirds may often rely on non-ornithophilous plants to meet their energy requirements. However, quantitative studies evaluating the relative importance of ornithophilous vs. non-ornithophilous plants for hummingbirds in these areas are scarce. We here studied the availability and use of floral resources by hummingbirds in two different areas of the Cerrado, the seasonal savannas in Central Brazil. Roughly half the hummingbird visited plant species were non-ornithophilous, and these contributed greatly to increase the overall nectar availability. We showed that mean nectar offer, at the transect scale, was the only parameter related to hummingbird visitation frequency, more so than nectar offer at single flowers and at the plant scale, or pollination syndrome. Centrality indices, calculated using hummingbird-plant networks, showed that ornithophilous and non-ornithophilous plants have similar importance for network cohesion. How this foraging behaviour affects reproduction of non-ornithophilous plants remains largely unexplored and is probably case specific, however, we suggest that the additional energy provided by non-ornithophilous plants may facilitate reproduction of truly ornithophilous flowers by attracting and maintaining hummingbirds in the area. This may promote asymmetric hummingbird-plant associations, i.e., pollination depends on floral traits adapted to hummingbird morphology, but hummingbird visitation is determined more by the energetic "reward" than by pollination syndromes.

  1. The hummingbird community and their floral resources in an urban forest remnant in Brazil

    Directory of Open Access Journals (Sweden)

    LC. Rodrigues

    Full Text Available The temporal and spatial resource use among hummingbirds was studied over 13 months in an urban forest remnant (Prosa State Park: PSP in Campo Grande, Mato Grosso do Sul, Brazil. Hummingbird visitation was recorded at three ornithophilous and eleven non-ornithophilous species. Flower density was roughly constant during the study period, with the density of non-ornithophilous flowers being higher than that of ornithophilous ones. Mean values of nectar volume and concentration were similar between ornithophilous and non-ornithophilous species. Eight hummingbird species were observed at PSP: Amazilia fimbriata, Anthracothorax nigricollis, Chlorostilbon lucidus, Eupetomena macroura, Hylocharis chrysura, Florisuga fusca, Thalurania furcata and an unidentified species. Hummingbird visit frequencies to ornithophilous and non-ornithophilous flowers were similar. However, some non-ornithophilous species received a higher number of visits, which seems to be related to their large number of open flowers per plant per day. The number of feedings bouts of hummingbirds increased with the total number of flowers observed per focal plant. All recorded species of hummingbirds visited non-ornithophilous flowers, predominantly melittophilous and generalised entomophilous flowers. Hummingbird species recorded at PSP may be viewed as generalists, visiting a large number of non-ornithophilous species. Despite being an urban forest, PSP is relatively rich in hummingbird species, suggesting that it provides important shelter and foraging sites for hummingbirds in such an environment.

  2. Evidence for ecological causation of sexual dimorphism in a hummingbird.

    Science.gov (United States)

    Temeles, E J; Pan, I L; Brennan, J L; Horwitt, J N

    2000-07-21

    Unambiguous examples of ecological causes of animal sexual dimorphism are rare. Here we present evidence for ecological causation of sexual dimorphism in the bill morphology of a hummingbird, the purple-throated carib. This hummingbird is the sole pollinator of two Heliconia species whose flowers correspond to the bills of either males or females. Each sex feeds most quickly at the flower species approximating its bill dimensions, which supports the hypothesis that floral specialization has driven the evolution of bill dimorphism. Further evidence for ecological causation of sexual dimorphism was provided by a geographic replacement of one Heliconia species by the other and the subsequent development of a floral dimorphism, with one floral morph matching the bills of males and the other of females.

  3. Optic flow stabilizes flight in ruby-throated hummingbirds.

    Science.gov (United States)

    Ros, Ivo G; Biewener, Andrew A

    2016-08-15

    Flying birds rely on visual cues for retinal image stabilization by negating rotation-induced optic flow, the motion of the visual panorama across the retina, through corrective eye and head movements. In combination with vestibular and proprioceptive feedback, birds may also use visual cues to stabilize their body during flight. Here, we test whether artificially induced wide-field motion generated through projected visual patterns elicits maneuvers in body orientation and flight position, in addition to stabilizing vision. To test this hypothesis, we present hummingbirds flying freely within a 1.2 m cylindrical visual arena with a virtual surround rotated at different speeds about its vertical axis. The birds responded robustly to these visual perturbations by rotating their heads and bodies with the moving visual surround, and by adjusting their flight trajectories, following the surround. Thus, similar to insects, hummingbirds appear to use optic flow cues to control flight maneuvers as well as to stabilize their visual inputs.

  4. Hummingbirds at artificial flowers made to resemble ornithophiles versus melittophiles

    Directory of Open Access Journals (Sweden)

    Wyndee A. Guzman

    2012-06-01

    Full Text Available Certain floral characteristics are associated with specific pollinators. Hummingbird-pollinated flowers are usually red, lack a landing platform, lack nectar guides, and contain a high amount of dilute sucrose-rich nectar. Here we test hypotheses concerning the reasons for these characters to the extent that they involve hummingbird responses. An array was set up of 16 artificial plants, each with five artificial flowers. (1 Flowers made to differ only in colour elicited a slight preference for red. (2 When colour was associated with nectar offerings, and birds generally learned to visit flowers that provided much more nectar but did not associatively learn differences as little as 2 µL. (3 Birds were offered 8 µL of 12% sucrose versus 2 µL of 48% hexose, and they did not prefer the dilute nectar; they showed no evidence of discerning sucrose from hexose; however, they preferred 48% over 12% sucrose when both were offered in the same quantity. (4 Birds preferred flowers that lacked landing platforms over those with landing platforms. (5 Birds were offered flowers with nectar guides, associated with differing nectar volumes, and they did not associate the higher nectar reward with either flower type. In summary, the feedback from hummingbirds reflects some of the differences between bird- and bee-adapted flowers, but nectar seemed less predictive than expected. Factors other than the behavioural proclivities of hummingbirds, such as adaptation to discourage bees, are discussed as additional causes for the differences between the syndromes. We also discuss significance testing for field experiments involving one unreplicated array.

  5. Into Turbulent Air: Hummingbird Aerodynamic Control in Unsteady Circumstances

    Science.gov (United States)

    2016-06-24

    of this study, we also completed analysis of hummingbird kinematic responses to transient vertical gusts and to flight in sheared flows , and have...Distribution A - Approved for Public Release 13. SUPPLEMENTARY NOTES 14. ABSTRACT We have completed and published experimental results and analysis pertaining...enough to interact with both wings elicited the greatest changes in roll, pitch, and yaw fluctuations, and also induced major increases in metabolic

  6. Heat dissipation during hovering and forward flight in hummingbirds.

    Science.gov (United States)

    Powers, Donald R; Tobalske, Bret W; Wilson, J Keaton; Woods, H Arthur; Corder, Keely R

    2015-12-01

    Flying animals generate large amounts of heat, which must be dissipated to avoid overheating. In birds, heat dissipation is complicated by feathers, which cover most body surfaces and retard heat loss. To understand how birds manage heat budgets during flight, it is critical to know how heat moves from the skin to the external environment. Hummingbirds are instructive because they fly at speeds from 0 to more than 12 m s(-1), during which they transit from radiative to convective heat loss. We used infrared thermography and particle image velocimetry to test the effects of flight speed on heat loss from specific body regions in flying calliope hummingbirds (Selasphorus calliope). We measured heat flux in a carcass with and without plumage to test the effectiveness of the insulation layer. In flying hummingbirds, the highest thermal gradients occurred in key heat dissipation areas (HDAs) around the eyes, axial region and feet. Eye and axial surface temperatures were 8°C or more above air temperature, and remained relatively constant across speeds suggesting physiological regulation of skin surface temperature. During hovering, birds dangled their feet, which enhanced radiative heat loss. In addition, during hovering, near-body induced airflows from the wings were low except around the feet (approx. 2.5 m s(-1)), which probably enhanced convective heat loss. Axial HDA and maximum surface temperature exhibited a shallow U-shaped pattern across speeds, revealing a localized relationship with power production in flight in the HDA closest to the primary flight muscles. We conclude that hummingbirds actively alter routes of heat dissipation as a function of flight speed.

  7. Vision and Control for UAVs: A Survey of General Methods and of Inexpensive Platforms for Infrastructure Inspection

    Science.gov (United States)

    Máthé, Koppány; Buşoniu, Lucian

    2015-01-01

    Unmanned aerial vehicles (UAVs) have gained significant attention in recent years. Low-cost platforms using inexpensive sensor payloads have been shown to provide satisfactory flight and navigation capabilities. In this report, we survey vision and control methods that can be applied to low-cost UAVs, and we list some popular inexpensive platforms and application fields where they are useful. We also highlight the sensor suites used where this information is available. We overview, among others, feature detection and tracking, optical flow and visual servoing, low-level stabilization and high-level planning methods. We then list popular low-cost UAVs, selecting mainly quadrotors. We discuss applications, restricting our focus to the field of infrastructure inspection. Finally, as an example, we formulate two use-cases for railway inspection, a less explored application field, and illustrate the usage of the vision and control techniques reviewed by selecting appropriate ones to tackle these use-cases. To select vision methods, we run a thorough set of experimental evaluations. PMID:26121608

  8. Evapotranspiration from UAV Images

    DEFF Research Database (Denmark)

    Nielsen, Helene Hoffmann Munk

    Current research on evapotranspiration (ET) is motivated by the growing world population and its demand for food and hence an intensified irrigation of cultivated lands, along with the need to better understand climate changes. ET links the land surface processes to the atmospheric processes...... and is thus of importance in both hydrological, agricultural and atmospheric sciences. Still today, accurate measurements of ET are not achieved easily. The state-of the-art method to measure ET, the eddy covariance method, is associated with uncertainties and its footprint, though at the order of around 1...... of measurements and thus new understandings of ET and its inferred parameters such as crop water stress and heat fluxes in the surface energy balance. However, UAV data collection is a new measuring method and the lightweight sensors are novel instrumentations. Workflows for processing UAV data, and the data...

  9. Toxic metals and associated sporulated bacteria on Andean hummingbird feathers.

    Science.gov (United States)

    Góngora, Esteban; Cadena, Carlos Daniel; Dussán, Jenny

    2016-11-01

    Human activities in the Sabana de Bogotá, Colombia, release toxic metals such as lead (Pb) and chromium (Cr) into the environment polluting the air, water, and soil. Because birds are in contact with these pollutants and their sources, they may serve as bioindicator organisms. We evaluated the use of hummingbird feathers obtained from individuals captured in three sites of the Sabana de Bogotá as bioindicators of toxic metal pollution using spectrophotometric and spectroscopic methods based on single-feather samples. We also characterized the bacterial microbiota associated with hummingbird feathers by molecular identification using the 16S rRNA with a special focus on sporulated bacteria. Finally, we described the interactions which naturally occur among the feathers, their associated bacteria, and pollutants. We found differences in Pb and Cr concentrations between sampling sites, which ranged from 2.11 to 4.69 ppm and 0.38 to 3.00 ppm, respectively. This may reflect the impact of the activities held in those sites which release pollutants to the environment. Bacterial assemblages mainly consisted of sporulated bacilli in the Bacillaceae family (65.7 % of the identified morphotypes). We conclude that the feathers of wild tropical birds, including hummingbirds, can be used as lead and chromium bioindicators and that bacteria growing on feathers may in fact interact with these two toxic metals.

  10. Towards a Biosynthetic UAV

    Science.gov (United States)

    Block, Eli; Byemerwa, Jovita; Dispenza, Ross; Doughty, Benjamin; Gillyard, KaNesha; Godbole, Poorwa; Gonzales-Wright, Jeanette; Hull, Ian; Kannappan, Jotthe; Levine, Alexander; Nelakanti, Raman; Ruffner, Lydia; Shumate, Alaina; Sorayya, Aryo; Ugwu, Kyla

    2014-01-01

    We are currently working on a series of projects towards the construction of a fully biological unmanned aerial vehicle (UAV) for use in scientific and humanitarian missions. The prospect of a biologically-produced UAV presents numerous advantages over the current manufacturing paradigm. First, a foundational architecture built by cells allows for construction or repair in locations where it would be difficult to bring traditional tools of production. Second, a major limitation of current research with UAVs is the size and high power consumption of analytical instruments, which require bulky electrical components and large fuselages to support their weight. By moving these functions into cells with biosensing capabilities - for example, a series of cells engineered to report GFP, green fluorescent protein, when conditions exceed a certain threshold concentration of a compound of interest, enabling their detection post-flight - these problems of scale can be avoided. To this end, we are working to engineer cells to synthesize cellulose acetate as a novel bioplastic, characterize biological methods of waterproofing the material, and program this material's systemic biodegradation. In addition, we aim to use an "amberless" system to prevent horizontal gene transfer from live cells on the material to microorganisms in the flight environment.

  11. Development of collision avoidance system for useful UAV applications using image sensors with laser transmitter

    Science.gov (United States)

    Cheong, M. K.; Bahiki, M. R.; Azrad, S.

    2016-10-01

    The main goal of this study is to demonstrate the approach of achieving collision avoidance on Quadrotor Unmanned Aerial Vehicle (QUAV) using image sensors with colour- based tracking method. A pair of high definition (HD) stereo cameras were chosen as the stereo vision sensor to obtain depth data from flat object surfaces. Laser transmitter was utilized to project high contrast tracking spot for depth calculation using common triangulation. Stereo vision algorithm was developed to acquire the distance from tracked point to QUAV and the control algorithm was designed to manipulate QUAV's response based on depth calculated. Attitude and position controller were designed using the non-linear model with the help of Optitrack motion tracking system. A number of collision avoidance flight tests were carried out to validate the performance of the stereo vision and control algorithm based on image sensors. In the results, the UAV was able to hover with fairly good accuracy in both static and dynamic collision avoidance for short range collision avoidance. Collision avoidance performance of the UAV was better with obstacle of dull surfaces in comparison to shiny surfaces. The minimum collision avoidance distance achievable was 0.4 m. The approach was suitable to be applied in short range collision avoidance.

  12. Nonlinear Adaptive Regulation Control of A Quadrotor Unmanned Aerial Vehicle%四旋翼无人飞行器的非线性自适应镇定控制器设计

    Institute of Scientific and Technical Information of China (English)

    曾伟; 鲜斌; 刁琛; 殷强; 李浩涛; 杨云高

    2011-01-01

    本文采用在线参数辨识与反馈控制相结合的方法,针对具有欠驱动特性的四旋翼无人飞行器,设计了一种非线性自适应镇定控制器,并且在进行控制器设计时,考虑到了飞行器转动惯量,空气阻尼,以及其他系统参数的不确定性。利用Lyapunov稳定性分析方法理论证明了四旋翼无人飞行器的镇定误差最终趋于零。仿真结果进一步验证了文中所提出的控制器具有良好的镇定效果。%In this paper, a nonlinear adaptive regulation controller is presented for a class of underactuated quadrotor unmanned aerial vehicle (UAV). The vehicle’s dynamics is sub ject to modeling impression associated with the inertia matrix, aerodynamic damping coefficients, and some other system parameters. The on-line parameter estimation scheme is combined with feedback control to develop the adaptive control laws. Lyapunov based approaches are utilized to prove that the quadrotor UAV’s position and yaw angle regulation errors are ultimately driven to zero under parametric uncertainties. Simulation results are included to demonstrate the performance of the control strategy.

  13. Hummingbird pollination and the diversification of angiosperms: an old and successful association in Gesneriaceae.

    Science.gov (United States)

    Serrano-Serrano, Martha Liliana; Rolland, Jonathan; Clark, John L; Salamin, Nicolas; Perret, Mathieu

    2017-04-12

    The effects of specific functional groups of pollinators in the diversification of angiosperms are still to be elucidated. We investigated whether the pollination shifts or the specific association with hummingbirds affected the diversification of a highly diverse angiosperm lineage in the Neotropics. We reconstructed a phylogeny of 583 species from the Gesneriaceae family and detected diversification shifts through time, inferred the timing and amount of transitions among pollinator functional groups, and tested the association between hummingbird pollination and speciation and extinction rates. We identified a high frequency of pollinator transitions, including reversals to insect pollination. Diversification rates of the group increased through time since 25 Ma, coinciding with the evolution of hummingbird-adapted flowers and the arrival of hummingbirds in South America. We showed that plants pollinated by hummingbirds have a twofold higher speciation rate compared with plants pollinated by insects, and that transitions among functional groups of pollinators had little impact on the diversification process. We demonstrated that floral specialization on hummingbirds for pollination has triggered rapid diversification in the Gesneriaceae family since the Early Miocene, and that it represents one of the oldest identified plant-hummingbird associations. Biotic drivers of plant diversification in the Neotropics could be more related to this specific type of pollinator (hummingbirds) than to shifts among different functional groups of pollinators. © 2017 The Author(s).

  14. Hummingbird wing efficacy depends on aspect ratio and compares with helicopter rotors

    NARCIS (Netherlands)

    Kruyt, J.W.; Quicazan Rubio, E.M.; Heijst, van G.J.F.; Altshuler, D.L.; Lentink, D.

    2014-01-01

    Hummingbirds are the only birds that can sustain hovering. This unique flight behaviour comes, however, at high energetic cost. Based on helicopter and aeroplane design theory, we expect that hummingbird wing aspect ratio (AR), which ranges from about 3.0 to 4.5, determines aerodynamic efficacy. Pre

  15. Generalist bees pollinate red-flowered Penstemon eatonii: Duality in the hummingbird pollination syndrome

    Science.gov (United States)

    James H. Cane; Rick. Dunne

    2014-01-01

    The red tubular flowers of Penstemon eatonii (Plantaginaceae) typify the classic pollination syndrome for hummingbirds. Bees are thought to diminish its seed siring potential, but we found that foraging female generalist bees (Apis, Anthophora) deposited substantial amounts of conspecific pollen on P. eatonii stigmas. In the absence of hummingbirds, bee pollination of...

  16. [Hummingbird abundance and flowers use in a template forest from Southeast Mexico].

    Science.gov (United States)

    Partida Lara, Ruth; Enríquez, Paula L; Rangel-Salazar, José Luis; Lara, Carlos; Martínez Ico, Miguel

    2012-12-01

    Hummingbird abundance varies with plant bloom phenology used for feeding. However, the information on hummingbird-flower interaction is limited for tropical mountain environments. We evaluated hummingbird abundance using mist nest and estimated monthly flowering phenology visited by hummingbirds in three different habitats (oak forest, cloud forest and bush) from January to August 2010 in Huitepec Ecological Reserve. We recorded four hummingbird species (Hylocharis leucotis, Lampornis amethystinus, Lamprolaima rhami and Eugenes fulgens), and their abundance varied among habitats (H3.8=14.8, p=0.001). Seven plant species were visited for hummingbirds and showed the highest number of flower species during dry season. Bush had the highest blossom. Fuchsia paniculata had the highest blossom period but only was visited by H. leucotis. Passiflora membranacea was the only species visited for all hummingbird species. The only positive association was E. fulgens abundance with P.a membranacea bloom (r(S)=0.93, p=0.02). Hummingbird abundance fluctuations in this study are determined for interactions with floral resources and their habitat distribution.

  17. Control of a Quadrotor Using a Smart Self-Tuning Fuzzy PID Controller

    Directory of Open Access Journals (Sweden)

    Deepak Gautam

    2013-11-01

    Full Text Available This paper deals with the modelling, simulation-based controller design and path planning of a four rotor helicopter known as a quadrotor. All the drags, aerodynamic, coriolis and gyroscopic effect are neglected. A Newton-Euler formulation is used to derive the mathematical model. A smart self-tuning fuzzy PID controller based on an EKF algorithm is proposed for the attitude and position control of the quadrotor. The PID gains are tuned using a self-tuning fuzzy algorithm. The self-tuning of fuzzy parameters is achieved based on an EKF algorithm. A smart selection technique and exclusive tuning of active fuzzy parameters is proposed to reduce the computational time. Dijkstra’s algorithm is used for path planning in a closed and known environment filled with obstacles and/or boundaries. The Dijkstra algorithm helps avoid obstacle and find the shortest route from a given initial position to the final position.

  18. Passification based simple adaptive control of quadrotor attitude: Algorithms and testbed results

    Science.gov (United States)

    Tomashevich, Stanislav; Belyavskyi, Andrey; Andrievsky, Boris

    2017-01-01

    In the paper, the results of the Passification Method with the Implicit Reference Model (IRM) approach are applied for designing the simple adaptive controller for quadrotor attitude. The IRM design technique makes it possible to relax the matching condition, known for habitual MRAC systems, and leads to simple adaptive controllers, ensuring fast tuning the controller gains, high robustness with respect to nonlinearities in the control loop, to the external disturbances and the unmodeled plant dynamics. For experimental evaluation of the adaptive systems performance, the 2DOF laboratory setup has been created. The testbed allows to safely test new control algorithms in the laboratory area with a small space and promptly make changes in cases of failure. The testing results of simple adaptive control of quadrotor attitude are presented, demonstrating efficacy of the applied simple adaptive control method. The experiments demonstrate good performance quality and high adaptation rate of the simple adaptive control system.

  19. Displays for future intermediate UAV

    Science.gov (United States)

    Desjardins, Daniel; Metzler, James; Blakesley, David; Rister, Courtney; Nuhu, Abdul-Razak

    2008-04-01

    The Dedicated Autonomous Extended Duration Airborne Long-range Utility System (DAEDALUS) is a prototype Unmanned Aerial Vehicle (UAV) that won the 2007 AFRL Commander's Challenge. The purpose of the Commander's Challenge was to find an innovative solution to urgent warfighter needs by designing a UAV with increased persistence for tactical employment of sensors and communication systems. DAEDALUS was chosen as a winning prototype by AFRL, AFMC and SECAF. Follow-on units are intended to fill an intermediate role between currently fielded Tier I and Tier II UAV's. The UAV design discussed in this paper, including sensors and displays, will enter Phase II for Rapid Prototype Development with the intent of developing the design for eventual production. This paper will discuss the DAEDALUS UAV prototype system, with particular focus on its communications, to include the infrared sensor and electro-optical camera, but also displays, specifically man-portable.

  20. Event-triggered nonlinear control for attitude stabilization of a quadrotor

    OpenAIRE

    Guerrero Castellanos, Fermi; Téllez-Guzmán, J. J.; Durand, Sylvain; Marchand, Nicolas; Álvarez-Muñoz, J. U.

    2013-01-01

    International audience; Event-triggered control is a ressource-aware sampling strategy that updates the control value only when a certain condition is satisfied, which denotes event instants. Such a technique allows to reduce the control computational cost and communications. In this paper, a quaternion-based feedback is developed for event-triggered attitude stabilization of a quadrotor mini-helicopter. The feedback is derived from the universal formula for event-triggered stabilization of g...

  1. Safe Certificate-Based Maneuvers for Teams of Quadrotors Using Differential Flatness

    OpenAIRE

    Wang, Li; Ames, Aaron D.; Egerstedt, Magnus

    2017-01-01

    Safety Barrier Certificates that ensure collision-free maneuvers for teams of differential flatness-based quadrotors are presented in this paper. Synthesized with control barrier functions, the certificates are used to modify the nominal trajectory in a minimally invasive way to avoid collisions. The proposed collision avoidance strategy complements existing flight control and planning algorithms by providing trajectory modifications with provable safety guarantees. The effectiveness of this ...

  2. Control and Optimization of a Variable-Pitch Quadrotor with Minimum Power Consumption

    Directory of Open Access Journals (Sweden)

    Shouzhao Sheng

    2016-03-01

    Full Text Available Recently, there has been a rapid growth of interest in quadrotors with electric variable-pitch propellers. The control and optimization of such propellers are important factors for improving the flight performance of the vehicles. Therefore, the steady-state identification method to estimate the parameters of the mathematical model of the electric variable-pitch propeller is developed. The steady-state control and optimization scheme with minimum power consumption and the adaptive compensation scheme for the variable-pitch propeller are then proposed, based on which the response performance of the lift force produced by the variable-pitch propeller can be greatly improved by using a cascade compensation scheme. Furthermore, the direct lift-based flight control strategy is presented, which can significantly contribute to the improvement of the flight performance, precisely because the roll, pitch, yaw and vertical channels of the variable-pitch quadrotor are approximately linearized and completely decoupled from each other in this case. The experimental results demonstrate that both the endurance performance and the positioning accuracy of the variable-pitch quadrotor are improved simultaneously by using the proposed method with minimum power consumption.

  3. DIRECT GEOREFERENCING OF UAVS

    Directory of Open Access Journals (Sweden)

    M. Bláha

    2012-09-01

    Full Text Available UAV systems have become an attractive data acquisition platform in emerging applications. As measuring instrument they extend the lineup of possible surveying methods in the field of geomatics. However, most of UAVs are equipped with low-cost navigation sensors such as GPS or INS, allowing a positioning accuracy of 3 to 5 m. As a result the acquired position- and orientation data fea- tures a low accuracy which implicates that it cannot be used in applications that require high precision data on cm-level (e.g. direct georeferencing. In this paper we will analyze the potential of differential post-processing of GPS data from UAV in order to im- prove the positioning accuracy for applications basing on direct georeferencing. Subsequently, the obtained results are compared and verified with a track of the octocopter carried out with a total station simultaneously to the GPS data acquisition. The results show that the differential post-processing essentially improved the accuracy of the Falcon position data. Thereby the average offset be- tween the data sets (GPS data, track and the corresponding standard deviation is 0.82 m and 0.45 m, respectively. However, under ideal conditions it is even possible to improve this positioning accuracy to the cm-range. Furthermore, there are still several sources of error such as the offset between the GPS antenna of the Falcon 8 and the prism which is used for the track. Considering this fact there is further room for improvement regarding the here discussed positioning method.

  4. Eye Morphology and Retinal Topography in Hummingbirds (Trochilidae: Aves).

    Science.gov (United States)

    Lisney, Thomas J; Wylie, Douglas R; Kolominsky, Jeffrey; Iwaniuk, Andrew N

    2015-01-01

    Hummingbirds are a group of small, highly specialized birds that display a range of adaptations to their nectarivorous lifestyle. Vision plays a key role in hummingbird feeding and hovering behaviours, yet very little is known about the visual systems of these birds. In this study, we measured eye morphology in 5 hummingbird species. For 2 of these species, we used stereology and retinal whole mounts to study the topographic distribution of neurons in the ganglion cell layer. Eye morphology (expressed as the ratio of corneal diameter to eye transverse diameter) was similar among all 5 species and was within the range previously documented for diurnal birds. Retinal topography was similar in Amazilia tzacatl and Calypte anna. Both species had 2 specialized retinal regions of high neuron density: a central region located slightly dorso-nasal to the superior pole of the pecten, where densities reached ∼ 45,000 cells · mm(-2), and a temporal area with lower densities (38,000-39,000 cells · mm(-2)). A weak visual streak bridged the two high-density areas. A retina from Phaethornis superciliosus also had a central high-density area with a similar peak neuron density. Estimates of spatial resolving power for all 3 species were similar, at approximately 5-6 cycles · degree(-1). Retinal cross sections confirmed that the central high-density region in C. anna contains a fovea, but not the temporal area. We found no evidence of a second, less well-developed fovea located close to the temporal retina margin. The central and temporal areas of high neuron density allow for increased spatial resolution in the lateral and frontal visual fields, respectively. Increased resolution in the frontal field in particular may be important for mediating feeding behaviors such as aerial docking with flowers and catching small insects.

  5. Convergence beyond flower morphology? Reproductive biology of hummingbird-pollinated plants in the Brazilian Cerrado.

    Science.gov (United States)

    Ferreira, C; Maruyama, P K; Oliveira, P E

    2016-03-01

    Convergent reproductive traits in non-related plants may be the result of similar environmental conditions and/or specialised interactions with pollinators. Here, we documented the pollination and reproductive biology of Bionia coriacea (Fabaceae), Esterhazya splendida (Orobanchaceae) and Ananas ananassoides (Bromeliaceae) as case studies in the context of hummingbird pollination in Cerrado, the Neotropical savanna of Central South America. We combined our results with a survey of hummingbird pollination studies in the region to investigate the recently suggested association of hummingbird pollination and self-compatibility. Plant species studied here differed in their specialisation for ornithophily, from more generalist A. ananassoides to somewhat specialist B. coriacea and E. splendida. This continuum of specialisation in floral traits also translated into floral visitor composition. Amazilia fimbriata was the most frequent pollinator for all species, and the differences in floral display and nectar energy availability among plant species affect hummingbirds' behaviour. Most of the hummingbird-pollinated Cerrado plants (60.0%, n = 20), including those studied here, were self-incompatible, in contrast to other biomes in the Neotropics. Association to more generalist, often territorial, hummingbirds, and resulting reduced pollen flow in open savanna areas may explain predominance of self-incompatibility. But it is possible that mating system is more associated with the predominance of woody hummingbird plants in the Cerrado plant assemblage than to the pollination system itself.

  6. The community of hummingbirds (Aves: Trochilidae) and the assemblage of flowers in a Caatinga vegetation.

    Science.gov (United States)

    Las-Casas, F M G; Azevedo Júnior, S M; Dias Filho, M M

    2012-02-01

    We studied hummingbirds and their food plants in an area of caatinga vegetation. We specifically examined their seasonal use of this habitat, migratory and non-migratory status, their foraging strategies and community roles The study was conducted in an area of arboreal-shrub caatinga, located in the Serra do Pará, municipality of Santa Cruz do Capibaribe, state of Pernambuco in northeastern Brazil. Field work was undertaken during 12 expeditions on a monthly basis between June, 2007 and May, 2008. Five species of hummingbirds were recorded visiting flowers in the community studied. Three were considered residents: Chlorostilbon lucidus (Shaw, 1812), Eupetomena macroura (Gmelin, 1788), and Heliomaster squamosus (Temminck, 1823). Hummingbirds visited 31 species of plants, of which only five presented attributes related to ornithophily. C. lucidus visited 29 plant species, including all ornithophilous species, and it was the most aggressive, defending territories. Among hummingbirds, C. lucidus may be considered the principal pollinator. Hummingbirds may also be acting as pollen vectors for some of the plant species not identified as ornithophilous. The hummingbird guilds varied among the plant species used as floral resources, as well as in their frequency of visits. Differences in plant species abundance, hummingbird preference, competitive exclusion or flowering seasonality are factors likely to influence those variations.

  7. Temporal-spatial segregation among hummingbirds foraging on honeydew in a temperate forest in Mexico

    Institute of Scientific and Technical Information of China (English)

    Carlos LARA; Vanessa MART(I)NEZ-GARC(I)A; Raúl ORTIZ-PULIDO; Jessica BRAVO-CADENA; Salvador LORANCA; Alex C(O)RDOBA-AGUILAR

    2011-01-01

    Spatial and temporal variation in interactions between hummingbirds and plants have often been examined, and hummingbirds and insects are known to indirectly interact in networks of nectar plants. In a highland temperate forest in Hidalgo,Mexico some oak trees were heavily infested by honeydew-producing insects (family Margarodidae, tribe Xylococcini, genus Strignacoccus) and the honeydew was consumed by hummingbirds. Here using survival analysis we investigate how the honeydew produced by dense populations of these margarodids is temporally and spatially partitioned by hummingbirds. We also measured the availability and quality of honeydew exudates, and then we recorded the time until a bird visited and used such re sources. Four hummingbird species consumed this resource (Atthis eloisa, Hylocharis leucotis, Colibri thalassinus and Eugenes fulgens). Data from 294 hours of observation on seven focal trees suggested temporal and spatial segregation among visiting birds according to body size and territorial behavior during the most honeydew-limited time. Hummingbird species differed in the daily times they foraged, as well as in the location where honeydew-producing insects were visited on the trees. Temporal and spatial segregation among hummingbird species is interpreted as an adaptation to reduce the risk of aggressive encounters. This may facilitate multispecies coexistence and allow these birds to exploit honeydew more effectively.

  8. Temporal-spatial segregation among hummingbirds foraging on honeydew in a temperate forest in Mexico

    Directory of Open Access Journals (Sweden)

    Carlos LARA, Vanessa MARTÍNEZ-GARCÍA, Raúl ORTIZ-PULIDO, Jessica BRAVO-CADENA, Salvador LORANCA, Alex CÓRDOBA-AGUILAR

    2011-02-01

    Full Text Available Spatial and temporal variation in interactions between hummingbirds and plants have often been examined, and hummingbirds and insects are known to indirectly interact in networks of nectar plants. In a highland temperate forest in Hidalgo, Mexico some oak trees were heavily infested by honeydew-producing insects (family Margarodidae, tribe Xylococcini, genus Strigmacoccus and the honeydew was consumed by hummingbirds. Here using survival analysis we investigate how the honeydew produced by dense populations of these margarodids is temporally and spatially partitioned by hummingbirds. We also measured the availability and quality of honeydew exudates, and then we recorded the time until a bird visited and used such resources. Four hummingbird species consumed this resource (Atthis eloisa, Hylocharis leucotis, Colibri thalassinus and Eugenes fulgens. Data from 294 hours of observation on seven focal trees suggested temporal and spatial segregation among visiting birds according to body size and territorial behavior during the most honeydew-limited time. Hummingbird species differed in the daily times they foraged, as well as in the location where honeydew-producing insects were visited on the trees. Temporal and spatial segregation among hummingbird species is interpreted as an adaptation to reduce the risk of aggressive encounters. This may facilitate multispecies coexistence and allow these birds to exploit honeydew more effectively [Current Zoology 57 (1: 56–62, 2011].

  9. UAV Cooperation Architectures for Persistent Sensing

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, R S; Kent, C A; Jones, E D

    2003-03-20

    With the number of small, inexpensive Unmanned Air Vehicles (UAVs) increasing, it is feasible to build multi-UAV sensing networks. In particular, by using UAVs in conjunction with unattended ground sensors, a degree of persistent sensing can be achieved. With proper UAV cooperation algorithms, sensing is maintained even though exceptional events, e.g., the loss of a UAV, have occurred. In this paper a cooperation technique that allows multiple UAVs to perform coordinated, persistent sensing with unattended ground sensors over a wide area is described. The technique automatically adapts the UAV paths so that on the average, the amount of time that any sensor has to wait for a UAV revisit is minimized. We also describe the Simulation, Tactical Operations and Mission Planning (STOMP) software architecture. This architecture is designed to help simulate and operate distributed sensor networks where multiple UAVs are used to collect data.

  10. Wake patterns of the wings and tail of hovering hummingbirds

    Science.gov (United States)

    Altshuler, Douglas L.; Princevac, Marko; Pan, Hansheng; Lozano, Jesse

    The flow fields of slowly flying bats and fasterflying birds differ in that bats produce two vortex loops during each stroke, one per wing, and birds produce a single vortex loop per stroke. In addition, the circulation at stroke transition approaches zero in bats but remains strong in birds. It is unknown if these difference derive from fundamental differences in wing morphology or are a consequence of flight speed. Here, we present an analysis of the horizontal flow field underneath hovering Anna's hummingbirds (Calypte anna) to describe the wake of a bird flying at zero forward velocity. We also consider how the hummingbird tail interacts with the wake generated by the wings. High-speed image recording and analysis from three orthogonal perspectives revealed that the wing tips reach peak velocities in the middle of each stroke and approach zero velocity at stroke transition. Hummingbirds use complex tail kinematic patterns ranging from in phase to antiphase cycling with respect to the wings, covering several phase shifted patterns. We employed particle image velocimetry to attain detailed horizontal flow measurements at three levels with respect to the tail: in the tail, at the tail tip, and just below the tail. The velocity patterns underneath the wings indicate that flow oscillates along the ventral-dorsal axis in response to the down- and up-strokes and that the sideways flows with respect to the bird are consistently from the lateral to medial. The region around the tail is dominated by axial flows in dorsal to ventral direction. We propose that these flows are generated by interaction between the wakes of the two wings at the end of the upstroke, and that the tail actively defects flows to generate moments that contribute to pitch stability. The flow fields images also revealed distinct vortex loops underneath each wing, which were generated during each stroke. From these data, we propose a model for the primary flow structures of hummingbirds that more

  11. Speciose opportunistic nectar-feeding avifauna in Cuba and its association to hummingbird island biogeography

    DEFF Research Database (Denmark)

    Dalsgaard, Bo; Baquero, Andrea C.; Rahbek, Carsten

    2016-01-01

    Island organisms often have wider feeding niches than mainland organisms, and migratory birds breeding on continents often widen their niches when overwintering on islands. Cuba's low hummingbird richness has puzzled ornithologists for decades. Here, we show that the Cuban hummingbird fauna is less...... rich than expected based on Cuba's elevation, when compared to the rest of the West Indian islands. Thereafter, we report nectar-feeding behaviour by 26 non-Trochilidae bird species in Cuba, encompassing pigeons/doves, woodpeckers and passerines, and endemic, resident and migratory species. We discuss...... if Cuba's speciose non-Trochilidae nectar-feeding avifauna may be associated with its depauperate hummingbird fauna....

  12. Optical and acoustical UAV detection

    Science.gov (United States)

    Christnacher, Frank; Hengy, Sébastien; Laurenzis, Martin; Matwyschuk, Alexis; Naz, Pierre; Schertzer, Stéphane; Schmitt, Gwenael

    2016-10-01

    Recent world events have highlighted that the proliferation of UAVs is bringing with it a new and rapidly increasing threat for national defense and security agencies. Whilst many of the reported UAV incidents seem to indicate that there was no terrorist intent behind them, it is not unreasonable to assume that it may not be long before UAV platforms are regularly employed by terrorists or other criminal organizations. The flight characteristics of many of these mini- and micro-platforms present challenges for current systems which have been optimized over time to defend against the traditional air-breathing airborne platforms. A lot of programs to identify cost-effective measures for the detection, classification, tracking and neutralization have begun in the recent past. In this paper, lSL shows how the performance of a UAV detection and tracking concept based on acousto-optical technology can be powerfully increased through active imaging.

  13. Location predicting methods for UAVs

    Science.gov (United States)

    Peng, Xiaodong; Zhang, Yu

    2017-08-01

    Location prediction of unmanned aerial vehicle (UAV) is important for fighting with its enemy and ensuring its normal operation. This paper presents the motion model of UAVs and reduces the state space into 7 dimensions. The Bayesian Network, Markov Chain, Curve Fitting and Neural Network are introduced for designing predicting methods. Then Curve Fitting Predicting method, Markov Chain Predicting method, Bayesian Network Predicting method and Neural Network Predicting method are designed for UAVs. The simulation result shows that 1) Neural Network Predicting method has highest predicting accuracy; 2) Markov Chain Predicting method and Bayesian Network Predicting method methods have similar performance and both are better than Bayesian Network Predicting method methods; 3) Neural Network Predicting method is the first choice when predicting the locations of UAVs.

  14. Flowers visited by hummingbirds in the open habitats of the southeastern brazilian mountaintops: species composition and seasonality

    Directory of Open Access Journals (Sweden)

    LC Rodrigues

    Full Text Available The hummingbird-visited plant community located on the open-habitat mountaintop of the Espinhaço Range was studied for two years (from August 2007 to July 2009 in Serra do Cipó National Park, Southeastern Brazil (19° 15′ S and 43° 31′ W. The floral characteristics and flowering period of the hummingbird-visited plants was monthly recorded along trails located in three vegetation types: (1 typical campos rupestres (TCR, (2 open fields (OPF, and (3 capões de mata(CAM. Hummingbird visitation was observed in 51 plant species, 22 ornithophilous and 29 non-ornithophilous species. The TCR showed the greatest number of species visited (N = 38, followed by the OPF (N = 18 and CAM (N = 17. Six species of hummingbirds were recorded visiting flowers: Augastes scutatus, Campylopterus largipennis, Colibri serrirostris, Chlorostilbon lucidus, Eupetomena macroura and Phaethornis pretrei. This study demonstrates that the species richness and the number of ornithophilous species visited by the hummingbirds at the study site are more similar to hummingbird-plant communities of the Atlantic Forest than to those of the Cerrado communities and other Brazilian highland open-habitat communities. The plant families most visited by hummingbirds were Bromeliaceae and Asteraceae. Although the Asteraceae family is rarely used as a food resource for hummingbirds in other high and lowland communities, in the study site this family is used mainly by the endemic hummingbird Augastes scutatus. We found a large overlap of flowering throughout the year among the species visited by the hummingbirds. Thus, the nectar availability supports these resident hummingbirds. The present study also showed that the studied hummingbird-plant community is composed of many species endemic to the campos rupestres of the Espinhaço Range, some of which are considered to be in danger of extinction, thus constituting a unique and threatened community. Thus, understanding hummingbird

  15. Flowers visited by hummingbirds in the open habitats of the southeastern Brazilian mountaintops: species composition and seasonality.

    Science.gov (United States)

    Rodrigues, L C; Rodrigues, M

    2014-08-01

    The hummingbird-visited plant community located on the open-habitat mountaintop of the Espinhaço Range was studied for two years (from August 2007 to July 2009) in Serra do Cipó National Park, Southeastern Brazil (19° 15' S and 43° 31' W). The floral characteristics and flowering period of the hummingbird-visited plants was monthly recorded along trails located in three vegetation types: (1) typical campos rupestres (TCR), (2) open fields (OPF), and (3) capões de mata (CAM). Hummingbird visitation was observed in 51 plant species, 22 ornithophilous and 29 non-ornithophilous species. The TCR showed the greatest number of species visited (N = 38), followed by the OPF (N = 18) and CAM (N = 17). Six species of hummingbirds were recorded visiting flowers: Augastes scutatus, Campylopterus largipennis, Colibri serrirostris, Chlorostilbon lucidus, Eupetomena macroura and Phaethornis pretrei. This study demonstrates that the species richness and the number of ornithophilous species visited by the hummingbirds at the study site are more similar to hummingbird-plant communities of the Atlantic Forest than to those of the Cerrado communities and other Brazilian highland open-habitat communities. The plant families most visited by hummingbirds were Bromeliaceae and Asteraceae. Although the Asteraceae family is rarely used as a food resource for hummingbirds in other high and lowland communities, in the study site this family is used mainly by the endemic hummingbird Augastes scutatus. We found a large overlap of flowering throughout the year among the species visited by the hummingbirds. Thus, the nectar availability supports these resident hummingbirds. The present study also showed that the studied hummingbird-plant community is composed of many species endemic to the campos rupestres of the Espinhaço Range, some of which are considered to be in danger of extinction, thus constituting a unique and threatened community. Thus, understanding hummingbird-plant pollination

  16. Roving UAV IED Interdiction System

    Science.gov (United States)

    2011-03-01

    protect both the troops and innocent civilian population from this insidious threat. UAVs may provide a fast , flexible platform for extending C-IED...considered to be 7,000 foot candles . Using the preceding data, the luminance of the UAV was estimated as the product of the illumination on the scene and...fuel. By looking at velocity over time, it was possible to see at what point level flight became possible as fuel burned off. Loiter velocity was

  17. Olfactory bulb size, odor discrimination and magnetic insensitivity in hummingbirds.

    Science.gov (United States)

    Ioalé, P; Papi, F

    1989-05-01

    Relative olfactory bulb size with respect to telencephalic hemispheres (olfactory ratio) was measured in five species of hummingbirds. Trochiliformes were found to be next to last among 25 avian orders with respect to olfactory bulb development. One hummingbird species, the White-vented Violetear (Colibri serrirostris), was trained in a successive go/no-go discrimination task, and learned to feed or not to feed from a container dependent on the olfactory stimuli associated with it. Test birds learned to discriminate amyl acetate vs. turpentine essence, jasmine essence vs. lavender essence, eucalyptus essence vs. no odor, beta-ionone vs. no odor, carvone vs. eucalyptol. In contrast, 1-phenylethanol vs. beta-ionone discrimination, two odorants which appear similar to humans, was unsuccessful. Using a similar procedure, attempts were made to condition a White-vented Violetear and a Versicolored Emerald (Amazilia versicolor) to magnetic stimuli. The birds were unable to discriminate between a normal field and an oscillating field (square wave, 1 Hz, amplitude +/- 0.40 G).

  18. Evapotranspiration from UAV Images

    DEFF Research Database (Denmark)

    Nielsen, Helene Hoffmann Munk

    resolutions not previously seen. Additionally, Paper 1 established that the good quality TIR measurements obtained during overcast weather situations can be combined with advanced algorithms originally developed for satellite images and clear sky conditions. Further, the fact that a relatively cheap UAV...... and is thus of importance in both hydrological, agricultural and atmospheric sciences. Still today, accurate measurements of ET are not achieved easily. The state-of the-art method to measure ET, the eddy covariance method, is associated with uncertainties and its footprint, though at the order of around 1...... hectare, varies much with the atmospheric stability and wind conditions. Indirect measurements of ET are obtained with satellite imagery, as a residual of the surface energy balance. Satellite images provide spatially distributed measurements, however high resolution satellite products provide footprints...

  19. Generalist bees pollinate red-flowered Penstemon eatonii: refining the hummingbird pollination syndrome

    Science.gov (United States)

    The red tubular flowers of Penstemon eatonii (Plantaginaceae, formerly Scrophulariaceae) conform to the classic pollination syndrome for hummingbirds. This could be problematic when farming this wildflower for rangeland restoration seed. By some models and experiments with nectaring bumblebees at ...

  20. Rangeland monitoring with unmanned aerial vehicles (UAVs)

    Science.gov (United States)

    Unmanned aerial vehicles (UAVs) have great potential for rangeland management applications, such as monitoring vegetation change, developing grazing strategies, determining rangeland health, and assessing remediation treatment effectiveness. UAVs have several advantages: they can be deployed quickly...

  1. UAV PHOTGRAMMETRIC WORKFLOWS: A BEST PRACTICE GUIDELINE

    National Research Council Canada - National Science Library

    A. Federman; M. Santana Quintero; S. Kretz; J. Gregg; M. Lengies; C. Ouimet; J. Laliberte

    2017-01-01

    The increasing commercialization of unmanned aerial vehicles (UAVs) has opened the possibility of performing low-cost aerial image acquisition for the documentation of cultural heritage sites through UAV photogrammetry...

  2. Flight and size constraints: hovering performance of large hummingbirds under maximal loading.

    Science.gov (United States)

    Chai, P; Millard, D

    1997-11-01

    As the smallest birds, hummingbirds are the only birds capable of prolonged hovering. This suggests that hovering locomotion scales unfavourably with size. Is the hovering performance of larger hummingbird species more constrained by size than that of smaller ones? Maximal load-lifting capacities of the two largest species of hummingbirds found in the United States, the blue-throated (Lampornis clemenciae, 8.4 g) and magnificent (Eugenes fulgens, 7.4 g) hummingbird, as well as the two other local small species, the black-chinned (Archilochus alexandri, 3.0 g) and rufus (Selasphorus rufus, 3.3 g) hummingbird, were determined under conditions of short-burst performance. The power reserves of hummingbirds are substantial relative to normal hovering performance. The two large species lifted maximal loads close to twice their body mass for a very brief duration of over 0.4 s. The small species lifted maximal loads approximately equal to their own mass with a longer duration of over 0.6 s. For the two large species under maximal loading, estimates of burst muscle mass-specific mechanical power output assuming perfect elastic energy storage averaged 309 W kg-1, compared with 75 W kg-1 during free hovering without loading. For the two small species, these values were 228 W kg-1 and 88 W kg-1, respectively. The differences in aerodynamic force production and power output between the large and small size classes occur despite their similar wing stroke velocity. This indicates that, during burst performance in these hummingbirds, the larger ones had a higher load-lifting capacity and generated more muscle power. In spite of the twofold difference in body mass, both large and small hummingbirds have evolved to become potent aerial competitors in order to exploit their common food resource, nectar. Both size classes have evolved to cope with the multi-dimensional effects of size constraining their aerodynamics, muscle mechanics, metabolism and ecology.

  3. Of hummingbirds and helicopters: Hovering costs, competitive ability, and foraging strategies

    OpenAIRE

    Altshuler, Douglas L.; Stiles, F. Gary; Dudley, Robert

    2004-01-01

    Wing morphology and flight kinematics profoundly influence foraging costs and the overall behavioral ecology of hummingbirds. By analogy with helicopters, previous energetic studies have applied the momentum theory of aircraft propellers to estimate hovering costs from wing disc loading (WDL), a parameter incorporating wingspan (or length) and body mass. Variation in WDL has been used to elucidate differences either among hummingbird species in nectar-foraging strategies (e.g., territoriality...

  4. Fault Estimation for a Quad-Rotor MAV Using a Polynomial Observer

    OpenAIRE

    Aguilar-Sierra, Hipolito; Flores Colunga, Gerardo Ramon; Salazar, Sergio; Lozano, Rogelio

    2013-01-01

    International audience; This work addresses the problem of fault detection and diagnosis (FDD) for a quad-rotor mini air vehicle (MAV). Actuator faults are considered on this paper. The basic idea behind the proposed method is to estimate the faults signals using the extended state observers theory. To estimate the faults, a polynomial observer (Aguilar et al. 2011; Mata-Machuca et al., Commun Nonlinear Sci Numer Simul 15(12):4114-4130, 2010, BioSystems 100(1):65-69, 2010) is presented by usi...

  5. Differential GNSS and Vision-Based Tracking to Improve Navigation Performance in Cooperative Multi-UAV Systems.

    Science.gov (United States)

    Vetrella, Amedeo Rodi; Fasano, Giancarmine; Accardo, Domenico; Moccia, Antonio

    2016-12-17

    Autonomous navigation of micro-UAVs is typically based on the integration of low cost Global Navigation Satellite System (GNSS) receivers and Micro-Electro-Mechanical Systems (MEMS)-based inertial and magnetic sensors to stabilize and control the flight. The resulting navigation performance in terms of position and attitude accuracy may not suffice for other mission needs, such as the ones relevant to fine sensor pointing. In this framework, this paper presents a cooperative UAV navigation algorithm that allows a chief vehicle, equipped with inertial and magnetic sensors, a Global Positioning System (GPS) receiver, and a vision system, to improve its navigation performance (in real time or in the post processing phase) exploiting formation flying deputy vehicles equipped with GPS receivers. The focus is set on outdoor environments and the key concept is to exploit differential GPS among vehicles and vision-based tracking (DGPS/Vision) to build a virtual additional navigation sensor whose information is then integrated in a sensor fusion algorithm based on an Extended Kalman Filter. The developed concept and processing architecture are described, with a focus on DGPS/Vision attitude determination algorithm. Performance assessment is carried out on the basis of both numerical simulations and flight tests. In the latter ones, navigation estimates derived from the DGPS/Vision approach are compared with those provided by the onboard autopilot system of a customized quadrotor. The analysis shows the potential of the developed approach, mainly deriving from the possibility to exploit magnetic- and inertial-independent accurate attitude information.

  6. Remote sensing from UAVs for hydrological monitoring

    DEFF Research Database (Denmark)

    Bandini, Filippo; Garcia, Monica; Bauer-Gottwein, Peter

    The potential of Unmanned Aerial Vehicles (UAVs) has significantly increased over the last five years due to cost reductions and improved sensors. In addition, advanced real time kinematic GPS techniques have enabled cm-accuracy navigation and flight control for UAVs. UAVs have numerous advantages...

  7. Developing Operator Models for UAV Search Scheduling

    NARCIS (Netherlands)

    Bertuccelli, L.F.; Beckers, N.W.M.; Cummings, M.L.

    2010-01-01

    With the increased use of Unmanned Aerial Vehicles (UAVs), it is envisioned that UAV operators will become high level mission supervisors, responsible for information management and task planning. In the context of search missions, operators supervising a large number of UAVs can become overwhelmed

  8. Adipose energy stores, physical work, and the metabolic syndrome: lessons from hummingbirds

    Directory of Open Access Journals (Sweden)

    Hargrove James L

    2005-12-01

    Full Text Available Abstract Hummingbirds and other nectar-feeding, migratory birds possess unusual adaptive traits that offer important lessons concerning obesity, diabetes and the metabolic syndrome. Hummingbirds consume a high sugar diet and have fasting glucose levels that would be severely hyperglycemic in humans, yet these nectar-fed birds recover most glucose that is filtered into the urine. Hummingbirds accumulate over 40% body fat shortly before migrations in the spring and autumn. Despite hyperglycemia and seasonally elevated body fat, the birds are not known to become diabetic in the sense of developing polyuria (glucosuria, polydipsia and polyphagia. The tiny (3–4 g Ruby-throated hummingbird has among the highest mass-specific metabolic rates known, and loses most of its stored fat in 20 h by flying up to 600 miles across the Gulf of Mexico. During the breeding season, it becomes lean and maintains an extremely accurate energy balance. In addition, hummingbirds can quickly enter torpor and reduce resting metabolic rates by 10-fold. Thus, hummingbirds are wonderful examples of the adaptive nature of fat tissue, and may offer lessons concerning prevention of metabolic syndrome in humans.

  9. Outperforming hummingbirds’ load-lifting capability with a lightweight hummingbird-like flapping-wing mechanism

    Directory of Open Access Journals (Sweden)

    Frederik Leys

    2016-08-01

    Full Text Available The stroke-cam flapping mechanism presented in this paper closely mimics the wing motion of a hovering Rufous hummingbird. It is the only lightweight hummingbird-sized flapping mechanism which generates a harmonic wing stroke with both a high flapping frequency and a large stroke amplitude. Experiments on a lightweight prototype of this stroke-cam mechanism on a 50 mm-long wing demonstrate that a harmonic stroke motion is generated with a peak-to-peak stroke amplitude of 175° at a flapping frequency of 40 Hz. It generated a mass lifting capability of 5.1 g, which is largely sufficient to lift the prototype's mass of 3.39 g and larger than the mass-lifting capability of a Rufous hummingbird. The motor mass of a hummingbird-like robot which drives the stroke-cam mechanism is considerably larger (about five times than the muscle mass of a hummingbird with comparable load-lifting capability. This paper presents a flapping wing nano aerial vehicle which is designed to possess the same lift- and thrust-generating principles of the Rufous hummingbird. The application is indoor flight. We give an overview of the wing kinematics and some specifications which should be met to develop an artificial wing, and also describe the applications of these in the mechanism which has been developed in this work.

  10. Different foraging preferences of hummingbirds on artificial and natural flowers reveal mechanisms structuring plant–pollinator interactions

    National Research Council Canada - National Science Library

    Maglianesi, María A; Böhning‐Gaese, Katrin; Schleuning, Matthias; Ings, Thomas

    2015-01-01

    ... pollinator communities. In this study, we tested whether morphological floral traits were associated with foraging preferences of hummingbirds for artificial and natural flower types in Costa Rica...

  11. A Simple Attitude Control of Quadrotor Helicopter Based on Ziegler-Nichols Rules for Tuning PD Parameters

    Directory of Open Access Journals (Sweden)

    ZeFang He

    2014-01-01

    Full Text Available An attitude control strategy based on Ziegler-Nichols rules for tuning PD (proportional-derivative parameters of quadrotor helicopters is presented to solve the problem that quadrotor tends to be instable. This problem is caused by the narrow definition domain of attitude angles of quadrotor helicopters. The proposed controller is nonlinear and consists of a linear part and a nonlinear part. The linear part is a PD controller with PD parameters tuned by Ziegler-Nichols rules and acts on the quadrotor decoupled linear system after feedback linearization; the nonlinear part is a feedback linearization item which converts a nonlinear system into a linear system. It can be seen from the simulation results that the attitude controller proposed in this paper is highly robust, and its control effect is better than the other two nonlinear controllers. The nonlinear parts of the other two nonlinear controllers are the same as the attitude controller proposed in this paper. The linear part involves a PID (proportional-integral-derivative controller with the PID controller parameters tuned by Ziegler-Nichols rules and a PD controller with the PD controller parameters tuned by GA (genetic algorithms. Moreover, this attitude controller is simple and easy to implement.

  12. A simple attitude control of quadrotor helicopter based on Ziegler-Nichols rules for tuning PD parameters.

    Science.gov (United States)

    He, ZeFang; Zhao, Long

    2014-01-01

    An attitude control strategy based on Ziegler-Nichols rules for tuning PD (proportional-derivative) parameters of quadrotor helicopters is presented to solve the problem that quadrotor tends to be instable. This problem is caused by the narrow definition domain of attitude angles of quadrotor helicopters. The proposed controller is nonlinear and consists of a linear part and a nonlinear part. The linear part is a PD controller with PD parameters tuned by Ziegler-Nichols rules and acts on the quadrotor decoupled linear system after feedback linearization; the nonlinear part is a feedback linearization item which converts a nonlinear system into a linear system. It can be seen from the simulation results that the attitude controller proposed in this paper is highly robust, and its control effect is better than the other two nonlinear controllers. The nonlinear parts of the other two nonlinear controllers are the same as the attitude controller proposed in this paper. The linear part involves a PID (proportional-integral-derivative) controller with the PID controller parameters tuned by Ziegler-Nichols rules and a PD controller with the PD controller parameters tuned by GA (genetic algorithms). Moreover, this attitude controller is simple and easy to implement.

  13. Piattaforme UAV per applicazioni geomatiche

    Directory of Open Access Journals (Sweden)

    Fabio Remondino

    2012-04-01

    Full Text Available Un’alternativa efficiente, veloce e low-cost al tradizionale rilievo aereo, ma ancora senza una regolamentazione chiara e con alcuni problemi di stabilità e payload. UAV platforms for geomaticsUAV platforms are nowadays a valuable source of data for inspection, surveillance, mapping and 3D modeling issues. New applications  in  the  short-  and  close-range  domain  are  intro-duced, being the UAVs a low-cost alternatives to the classical manned  aerial  photogrammetry.  Rotary  or  fixed  wing  UAVs, capable  of  performing  the  photogrammetric  data  acquisition  with  amateur  or  SLR  digital  cameras,  can  fly  in  manual, semi-automated and autonomous modes. With a typical photogrammetric  pipeline,  3D  results  like  DSM/DTM,  contour lines, textured 3D models, vector data, etc. can be produced, in a reasonable automated way. The article reports the latest developments of UAV image processing methods for photogrammetric applications with also some insight on regulation and system certifications.

  14. Autonomous unmanned air vehicles (UAV) techniques

    Science.gov (United States)

    Hsu, Ming-Kai; Lee, Ting N.

    2007-04-01

    The UAVs (Unmanned Air Vehicles) have great potentials in different civilian applications, such as oil pipeline surveillance, precision farming, forest fire fighting (yearly), search and rescue, boarder patrol, etc. The related industries of UAVs can create billions of dollars for each year. However, the road block of adopting UAVs is that it is against FAA (Federal Aviation Administration) and ATC (Air Traffic Control) regulations. In this paper, we have reviewed the latest technologies and researches on UAV navigation and obstacle avoidance. We have purposed a system design of Jittering Mosaic Image Processing (JMIP) with stereo vision and optical flow to fulfill the functionalities of autonomous UAVs.

  15. A Shape-Adjusted Tridimensional Reconstruction of Cultural Heritage Artifacts Using a Miniature Quadrotor

    Directory of Open Access Journals (Sweden)

    Théo Louiset

    2016-10-01

    Full Text Available The innovative automated 3D modeling procedure presented here was used to reconstruct a Cultural Heritage (CH object by means of an unmanned aerial vehicle. Using a motion capture system, a small low-cost quadrotor equipped with a miniature low-resolution Raspberry Pi camera module was accurately controlled in the closed loop mode and made to follow a trajectory around the artifact. A two-stage process ensured the accuracy of the 3D reconstruction process. The images taken during the first circular trajectory were used to draw the artifact’s shape. The second trajectory was smartly and autonomously adjusted to match the artifact’s shape, then it provides new pictures taken close to the artifact and, thus, greatly improves the final 3D reconstruction in terms of the completeness, accuracy and quickness, in particular where the artifact’s shape is complex. The results obtained here using close-range photogrammetric methods show that the process of automated 3D model reconstruction based on a robotized quadrotor using a motion capture system is a realistic approach, which could provide a suitable new digital conservation tool in the cultural heritage field.

  16. INTEGRATING UAV INTO GEOMATICS CURRICULUM

    Directory of Open Access Journals (Sweden)

    R. Al-Tahir

    2015-08-01

    Full Text Available Unmanned aerial vehicles (UAV have gained tremendous interest as a platform for surveying and mapping over the last few years, and have opened up a new realm of opportunities for surveying, orthophoto production, 3D modelling and feature extraction. UAVs provide a viable and affordable alternative for the airborne and space borne sensors for the medium/large scale mapping. This paper argues that universities should expand their education and training programs to include UAV-based geomatics operations and application development. Based on the author’s own experience as well other cases, details are developed and presented in this paper with respect to the likely syllabi and practical assignments. Alternatives for hardware and software support will be briefly discussed.

  17. Development of Micro UAV Swarms

    Science.gov (United States)

    Bürkle, Axel; Leuchter, Sandro

    Some complex application scenarios for micro UAVs (Unmanned Aerial Vehicles) call for the formation of swarms of multiple drones. In this paper a platform for the creation of such swarms is presented. It consists of modified commercial quadrocopters and a self-made ground control station software architecture. Autonomy of individual drones is generated through a micro controller equipped video camera. Currently it is possible to fly basic maneuvers autonomously, such as take-off, fly to position, and landing. In the future the camera's image processing capabilities will be used to generate additional control information. Different co-operation strategies for teams of UAVs are currently evaluated with an agent based simulation tool. Finally complex application scenarios for multiple micro UAVs are presented.

  18. The Vacuum-Compacted Regolith Gripping Mechanism and Unmanned Flights via Quad-Rotors

    Science.gov (United States)

    Scott, Rollin L.

    2014-01-01

    position, energy is being saved because the vacuum created the same resistance the running servos did without using power. The Unmanned Flights via Quad-rotors are built because multi-rotor dynamics are an important starting point and fair analog for space craft control systems and they make good terrestrial development platforms for various aspects of control for space crafts. The project is being conducted to see what the thrust response is going to be when a pulse width modulation command is sent to the control system since the quad-rotors are PWM controlled. A simulation environment in constructed so that one can quickly iterate and test different designs such as control systems, PID control vs. LDR control, and state estimation. Using two DIY Quad Kits, APM 2.6, testing apparatus (called a data acquisition system) to test the quad-rotors, and a simulation program such as Simulink, two quad-rotors are built and controlled via a simulation program, which is designed to be as realistic as possible and not idealistic. Due to the quad-rotors not being completely built nor ready for testing, there are no results or conclusions to report.

  19. UAV Swarm Behavior Modeling for Early Exposure of Failure Modes

    Science.gov (United States)

    2016-09-01

    is present. If that is not feasible, the UAV should immediately reduce altitude and land. The landing method is a mission driven behavior that does...new operation to allow the nearest UAV to relieve the bingo fueled UAV. Once the new UAV arrives, the UAV experiencing the bingo fuel failure mode

  20. Towards FAA Certification of UAVs

    Science.gov (United States)

    Nelson, Stacy

    2003-01-01

    As of June 30, 2003, all Unmanned Aerial Vehicles (UAV), no matter how small, must adhere to the same FAA regulations as human-piloted aircraft. These regulations include certification for flying in controlled airspace and certification of flight software based on RTCA DO-178B. This paper provides an overview of the steps necessary to obtain certification, as well as a discussion about the challenges UAV's face when trying to meet these requirements. It is divided into two parts: 1) Certifications for Flying in Controlled Airspace; 2) Certification of Flight Software per RTCA DO-178B.

  1. Swarming UAVs mission design strategy

    Science.gov (United States)

    Lin, Kuo-Chi

    2007-04-01

    This paper uses a behavioral hierarchy approach to reduce the mission solution space and make the mission design easier. A UAV behavioral hierarchy is suggested, which is derived from three levels of behaviors: basic, individual and group. The individual UAV behavior is a combination of basic, lower level swarming behaviors with priorities. Mission design can be simplified by picking the right combination of individual swarming behaviors, which will emerge the needed group behaviors. Genetic Algorithm is used in both lower-level basic behavior design and mission design.

  2. 小型四旋翼无人机建模与控制仿真%Modeling and Simulation of Microquadrotor UAV

    Institute of Scientific and Technical Information of China (English)

    孟佳东; 赵志刚

    2013-01-01

    Microquadrotor UAV is a underactuated system with six degrees of freedom and four drivers and strong coupling system with four rotors distributing in cruciform structure symmetrically and uniformly. The flight attitude can be controlled by the variant rotor speeds of changing the lift forces. On the basis of the unique mechanical structure and flight principle of the microquadrotor UAV, Newton-Euler equation is used to establish the nonlinear dynamic equation in order to improve its flight performance and control stability. A decoupling PID four-channel control system is designed according to the model, and it is simulated by Matlab/Simulink software. The result indicates that the flight attitude of quadrotor UAV can be controlled by changing the rotor speed and the model and PID control system can lay a good foundation for the study of quadrotor UAV later.%小型四旋翼无人机是一种具有六个自由度和四个输入的欠驱动强耦合飞行器,四只旋翼对称均匀分布在十字架结构的四个端点上,仅通过改变四只旋翼的转速即可改变飞行姿态.基于微型四旋翼无人机特有的机械结构和飞行原理,为提高其飞行性能和控制的稳定性,利用牛顿—欧拉方程,建立小型四旋翼飞行器的非线性动力学方程,并针对该模型设计一解耦PID四通道控制系统,且在Matlab/Simulink仿真平台上,对该PID控制系统进行仿真.仿真结果表明:通过改变旋翼的转速可实现四旋翼飞行器姿态的控制,同时该非线性模型和PID控制系统为其后续的四旋翼无人机的控制研究奠定了一定的基础.

  3. DNA hybridization evidence for the principal lineages of hummingbirds (Aves:Trochilidae).

    Science.gov (United States)

    Bleiweiss, R; Kirsch, J A; Matheus, J C

    1997-03-01

    The spectacular evolutionary radiation of hummingbirds (Trochilidae) has served as a model system for many biological studies. To begin to provide a historical context for these investigations, we generated a complete matrix of DNA hybridization distances among 26 hummingbirds and an outgroup swift (Chaetura pelagica) to determine the principal hummingbird lineages. FITCH topologies estimated from symmetrized delta TmH-C values and subjected to various validation methods (bootstrapping, weighted jackknifing, branch length significance) indicated a fundamental split between hermit (Eutoxeres aquila, Threnetes ruckeri; Phaethornithinae) and nonhermit (Trochilinae) hummingbirds, and provided strong support for six principal nonhermit clades with the following branching order: (1) a predominantly lowland group comprising caribs (Eulampis holosericeus) and relatives (Androdon aequatorialis and Heliothryx barroti) with violet-ears (Colibri coruscans) and relatives (Doryfera ludovicae); (2) an Andean-associated clade of highly polytypic taxa (Eriocnemis, Heliodoxa, and Coeligena); (3) a second endemic Andean clade (Oreotrochilus chimborazo, Aglaiocercus coelestis, and Lesbia victoriae) paired with thorntails (Popelairia conversii); (4) emeralds and relatives (Chlorostilbon mellisugus, Amazilia tzacatl, Thalurania colombica, Orthorhyncus cristatus and Campylopterus villaviscensio); (5) mountain-gems (Lampornis clemenciae and Eugenes fulgens); and (6) tiny bee-like forms (Archilochus colubris, Myrtis fanny, Acestrura mulsant, and Philodice mitchellii). Corresponding analyses on a matrix of unsymmetrized delta values gave similar support for these relationships except that the branching order of the two Andean clades (2, 3 above) was unresolved. In general, subsidiary relationships were consistent and well supported by both matrices, sometimes revealing surprising associations between forms that differ dramatically in plumage and bill morphology. Our results also reveal some

  4. VOCALIZATIONS AND ASSOCIATED BEHAVIORS OF THE SOMBRE HUMMINGBIRD (APHANTOCHROA CIRRHOCHLORIS) AND THE RUFOUS-BREASTED HERMIT (GLAUCIS HIRSUTUS)

    Science.gov (United States)

    Ferreira, Adriana R. J.; Smulders, Tom V.; Sameshima, Koichi; Mello, Claudio V.; Jarvis, Erich D.

    2008-01-01

    Vocal behavior in tropical hummingbirds is a new area of study. Here, we present findings on the vocalizations and associated behaviors of two species: Sombre Hummingbird (Aphantochroa cirrhochloris) and Rufous-breasted Hermit (Glaucis hirsutus). These are the only hummingbirds in which the brain areas activated by singing have been demonstrated. They are also among the basal species of their respective subfamilies, Trochilinae and Phaethornithinae and, thus, represent early stages in the evolution of hummingbird vocal communication. We found that the two species exhibit distinctive vocalizations and behaviors. Sombre Hummingbird calls had more modulation and were often used during agonistic interactions, whereas Rufous-breasted Hermit calls had higher pitch and purer tones and were produced in less aggressive interactions. Sombre Hummingbird song was highly stereotyped in syllable structure and syntax, whereas Rufous-breasted Hermit song was highly variable. Comparative analysis points to consistent similarities in use of vocalizations by the Sombre Hummingbird and other trochilines, and by the Rufous-breasted Hermit and other phaethornithines. We hypothesize that differences in vocal behavior between hummingbird lineages arise as adaptations to their foraging strategies. PMID:18802498

  5. Haptic Interface for UAV Teleoperation

    NARCIS (Netherlands)

    Lam, T.M.

    2009-01-01

    In the teleoperation of an uninhabited aerial vehicle (UAV), the human operator is physically separated from the vehicle and lacks various multiple-sensory information such as sound, motions, and vibrations of the airframe. The operator is usually only provided with visual information, e.g., from ca

  6. Haptic Interface for UAV Teleoperation

    NARCIS (Netherlands)

    Lam, T.M.

    2009-01-01

    In the teleoperation of an uninhabited aerial vehicle (UAV), the human operator is physically separated from the vehicle and lacks various multiple-sensory information such as sound, motions, and vibrations of the airframe. The operator is usually only provided with visual information, e.g., from ca

  7. Do hummingbirds use a different mechanism than insects to flip and twist their wings?

    Science.gov (United States)

    Song, Jialei; Luo, Haoxiang; Hedrick, Tyson

    2014-11-01

    Hovering hummingbirds flap their wings in an almost horizontal stroke plane and flip the wings to invert the angle of attack after stroke reversal, a strategy also utilized by many hovering insects such as fruit flies. However, unlike insects whose wing actuation mechanism is only located at the base, hummingbirds have a vertebrate musculoskeletal system and their wings contain bones and muscles and thus, they may be capable of both actively flipping and twisting their wings. To investigate this issue, we constructed a hummingbird wing model and study its pitching dynamics. The wing kinematics are reconstructed from high-speed imaging data, and the inertial torques are calculated in a rotating frame of reference using mass distribution data measured from dissections of hummingbird wings. Pressure data from a previous CFD study of the same wing kinematics are used to calculate the aerodynamic torque. The results show that like insect wings, the hummingbird wing pitching is driven by its own inertia during reversal, and the aerodynamic torque is responsible for wing twist during mid-stroke. In conclusion, our study suggests that their wing dynamics are very similar even though their actuation systems are entirely different. This research was supported by the NSF.

  8. Wild, free-living rufous hummingbirds do not use geometric cues in a spatial task.

    Science.gov (United States)

    Hornsby, Mark A W; Hurly, T Andrew; Hamilton, Caitlin E; Pritchard, David J; Healy, Susan D

    2014-10-01

    In the laboratory, many species orient themselves using the geometric properties of an enclosure or array and geometric information is often preferred over visual cues. Whether animals use geometric cues when relocating rewarded locations in the wild, however, has rarely been investigated. We presented free-living rufous hummingbirds with a rectangular array of four artificial flowers to investigate learning of rewarded locations using geometric cues. In one treatment, we rewarded two of four flowers at diagonally opposite corners. In a second treatment, we provided a visual cue to the rewarded flower by connecting the flowers with "walls" consisting of four dowels (three white, one blue) laid on the ground connecting each of the flowers. Neither treatment elicited classical geometry results; instead, hummingbirds typically chose one particular flower over all others. When we exchanged that flower with another, hummingbirds tended to visit the original flower. These results suggest that (1) hummingbirds did not use geometric cues, but instead may have used a visually derived cue on the flowers themselves, and (2) using geometric cues may have been more difficult than using visual characteristics. Although hummingbirds typically prefer spatial over visual information, we hypothesize that they will not use geometric cues over stable visual features but that they make use of small, flower-specific visual cues. Such cues may play a more important role in foraging decisions than previously thought. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Structure of the vortex wake in hovering Anna's hummingbirds (Calypte anna).

    Science.gov (United States)

    Wolf, M; Ortega-Jimenez, V M; Dudley, R

    2013-12-22

    Hummingbirds are specialized hoverers for which the vortex wake has been described as a series of single vortex rings shed primarily during the downstroke. Recent findings in bats and birds, as well as in a recent study on Anna's hummingbirds, suggest that each wing may shed a discrete vortex ring, yielding a bilaterally paired wake. Here, we describe the presence of two discrete rings in the wake of hovering Anna's hummingbirds, and also infer force production through a wingbeat with contributions to weight support. Using flow visualization, we found separate vortices at the tip and root of each wing, with 15% stronger circulation at the wingtip than at the root during the downstroke. The upstroke wake is more complex, with near-continuous shedding of vorticity, and circulation of approximately equal magnitude at tip and root. Force estimates suggest that the downstroke contributes 66% of required weight support, whereas the upstroke generates 35%. We also identified a secondary vortex structure yielding 8-26% of weight support. Lift production in Anna's hummingbirds is more evenly distributed between the stroke phases than previously estimated for Rufous hummingbirds, in accordance with the generally symmetric down- and upstrokes that characterize hovering in these birds.

  10. High proportion of smaller ranged hummingbird species coincides with ecological specialization across the Americas

    Science.gov (United States)

    Martín González, Ana M.; Maruyama, Pietro K.; Sandel, Brody; Vizentin-Bugoni, Jeferson; Schleuning, Matthias; Abrahamczyk, Stefan; Alarcón, Ruben; Araujo, Andréa C.; Araújo, Francielle P.; Mendes de Azevedo, Severino; Baquero, Andrea C.; Cotton, Peter A.; Ingversen, Tanja Toftemark; Kohler, Glauco; Lara, Carlos; Guedes Las-Casas, Flor Maria; Machado, Adriana O.; Machado, Caio Graco; Maglianesi, María Alejandra; Moura, Alan Cerqueira; Nogués-Bravo, David; Oliveira, Genilda M.; Oliveira, Paulo E.; Ornelas, Juan Francisco; Rodrigues, Licléia da Cruz; Rosero-Lasprilla, Liliana; Rui, Ana Maria; Sazima, Marlies; Timmermann, Allan; Varassin, Isabela Galarda; Wang, Zhiheng; Watts, Stella; Fjeldså, Jon; Svenning, Jens-Christian; Rahbek, Carsten; Dalsgaard, Bo

    2016-01-01

    Ecological communities that experience stable climate conditions have been speculated to preserve more specialized interspecific associations and have higher proportions of smaller ranged species (SRS). Thus, areas with disproportionally large numbers of SRS are expected to coincide geographically with a high degree of community-level ecological specialization, but this suggestion remains poorly supported with empirical evidence. Here, we analysed data for hummingbird resource specialization, range size, contemporary climate, and Late Quaternary climate stability for 46 hummingbird–plant mutualistic networks distributed across the Americas, representing 130 hummingbird species (ca 40% of all hummingbird species). We demonstrate a positive relationship between the proportion of SRS of hummingbirds and community-level specialization, i.e. the division of the floral niche among coexisting hummingbird species. This relationship remained strong even when accounting for climate, furthermore, the effect of SRS on specialization was far stronger than the effect of specialization on SRS, suggesting that climate largely influences specialization through species' range-size dynamics. Irrespective of the exact mechanism involved, our results indicate that communities consisting of higher proportions of SRS may be vulnerable to disturbance not only because of their small geographical ranges, but also because of their high degree of specialization. PMID:26842573

  11. Of hummingbirds and helicopters: hovering costs, competitive ability, and foraging strategies.

    Science.gov (United States)

    Altshuler, Douglas L

    2004-01-01

    Wing morphology and flight kinematics profoundly influence foraging costs and the overall behavioral ecology of hummingbirds. By analogy with helicopters, previous energetic studies have applied the momentum theory of aircraft propellers to estimate hovering costs from wing disc loading (WDL), a parameter incorporating wingspan (or length) and body mass. Variation in WDL has been used to elucidate differences either among hummingbird species in nectar-foraging strategies (e.g., territoriality, traplining) and dominance relations or among gender-age categories within species. We first demonstrate that WDL, as typically calculated, is an unreliable predictor of hovering (induced power) costs; predictive power is increased when calculations use wing length instead of wingspan and when actual wing stroke amplitudes are incorporated. We next evaluate the hypotheses that foraging strategy and competitive ability are functions of WDL, using our data in combination with those of published sources. Variation in hummingbird behavior cannot be easily classified using WDL and instead is correlated with a diversity of morphological and physiological traits. Evaluating selection pressures on hummingbird wings will require moving beyond wing and body mass measurements to include the assessment of the aerodynamic forces, power requirements, and power reserves of hovering, forward flight, and maneuvering. However, the WDL-helicopter dynamics model has been instrumental in calling attention to the importance of comparative wing morphology and related aerodynamics for understanding the behavioral ecology of hummingbirds.

  12. Effect of artificial feeders on pollen loads of the hummingbirds of Cerro de la Muerte, Costa Rica.

    Science.gov (United States)

    Avalos, Gerardo; Soto, Alejandra; Alfaro, Willy

    2012-03-01

    Although sugar-water feeders are commonly used by enthusiasts to attract hummingbirds, little is known about how they affect hummingbird behavior and flower use. We studied the highland hummingbird assemblage of Cerro de La Muerte, Costa Rica, both at a site with permanent feeders (La Georgina Restaurant) and further from it. We examined how feeder use and monopolization affected seasonal changes in pollen loads during four sampling periods, including dry and wet seasons, from 2003-2005. We expected that species monopolizing the feeders would carry little or no pollen whatsoever, and would have pollen loads characterized by low floral diversity, in contrast with species less dependent on feeders. We obtained pollen samples from 183 individuals of four hummingbird species captured around the feeders using mist nets, which were compared with a pollen reference collection of plants with a pollination syndrome by hummingbirds. The same methods were implemented at a site 3km away from the feeders. Feeder usage was quantified by counting the number of times hummingbirds drank from the feeders in periods of 4min separated by 1min. The effects of hummingbird species and season on pollen load categories were assessed using a nominal logistic regression. The alpha species at the site, the Fiery-throated Hummingbird (Panterpe insignis), dominated the feeders during the dry season. Meanwhile, in the wet season, feeder usage was more evenly distributed across species, with the exception of the Volcano Hummingbird, Selasphorus flammula, which occupies the last place in the dominance hierarchy. Pollen loads of hummingbirds captured near feeders were low in abundance (more than 50% of captured individuals had zero or low pollen loads), and low in species richness (96% of the hummingbirds with pollen from only one plant genus, Centropogon). Overall pollen loads increased during the dry season coinciding with peaks in flower availability, although the majority of captured

  13. The cubature smooth variable structure filter estimation strategy applied to a quadrotor controller

    Science.gov (United States)

    Al-Shabi, M.; Gadsden, S. A.; Wilkerson, S. A.

    2015-05-01

    Unmanned aerial systems (UAS) are becoming increasingly popular in industry, military, and social environments. An UAS that provides good operating performance and robustness to disturbances is often quite expensive and prohibitive to the general public. To improve UAS performance without affecting the overall cost, an estimation strategy can be implemented on the internal controller. The use of an estimation strategy or filter reduces the number of required sensors and power requirement, and improves the controller performance. UAS devices are highly nonlinear, and implementation of filters can be quite challenging. This paper presents the implementation of the relatively new cubature smooth variable structure filter (CSVSF) on a quadrotor controller. The results are compared with other state and parameter estimation strategies.

  14. Global Tracking Control of Quadrotor VTOL Aircraft in Three-Dimensional Space

    Directory of Open Access Journals (Sweden)

    Duc Khac Do

    2014-07-01

    Full Text Available This paper presents a method to design controllers that force a quadrotor vertical take-off and landing (VTOL aircraft to globally asymptotically track a reference trajectory in three-dimensional space. Motivated by the vehicle's steering practice, the roll and pitch angles are considered as immediate controls plus the total thrust force  provided by the aircraft's four rotors to control the position and yaw angle of the aircraft. The control design is based on the newly introduced one-step ahead backstepping, the standard backstepping and Lyapunov's direct methods. A combination of Euler angles and unit-quaternion for the attitude representation of the aircraft is used to obtain global tracking control results. The paper also includes a design of observers that exponentially estimate the aircraft's linear velocity vector and disturbances. Simulations illustrate the results.

  15. Coordination control of quadrotor VTOL aircraft in three-dimensional space

    Science.gov (United States)

    Do, K. D.

    2015-03-01

    This paper presents a constructive design of distributed coordination controllers for a group of N quadrotor vertical take-off and landing (VTOL) aircraft in three-dimensional space. A combination of Euler angles and unit-quaternion for the attitude representation of the aircraft is used to result in an effective control design, and to reduce singularities in the aircraft's dynamics. The coordination control design is based on a new bounded control design technique for second-order systems and new pairwise collision avoidance functions. The pairwise collision functions are functions of both relative positions and relative velocities between the aircraft instead of only their relative positions as in the literature. To overcome the inherent underactuation of the aircraft, the roll and pitch angles of the aircraft are considered as immediate controls. Simulations illustrate the results.

  16. Swarm intelligence for autonomous UAV control

    OpenAIRE

    Frantz, Natalie R.

    2005-01-01

    Unmanned Aerial Vehicles (UAVs) are becoming vital warfare platforms because they significantly reduce the risk of human life while accomplishing important missions. A UAV can be used for example, as stand-in sensor for the detection of mobile, low-probability-of-intercept battlefield surveillance and fire control emitters. With many UAVs acting together as a swarm, the location and frequency characteristics of each emitter can be accurately determined to continuously provide complete batt...

  17. Local origin and diversification among Lampornis hummingbirds: a Mesoamerican taxon.

    Science.gov (United States)

    García-Moreno, Jaime; Cortés, Nandadeví; García-Deras, Gabriela M; Hernández-Baños, Blanca E

    2006-02-01

    The huge biodiversity found in Mesoamerica is often explained by its geographic situation as a natural bridge between two large biogeographic regions. Often overlooked, however, are the high levels of speciation and diversification in the area. Here we assess the phylogenetic relationships within a Mesoamerican group of hummingbirds (Lampornis). We sequenced both mtDNA (1,143 bp of cyt b and 727 bp of ND5) and nuclear genes (505 bp of AK-5 intron and 567 bp of c-mos) for each of the seven recognised species and outgroups. We find two or three clades of similar age within this genus: L. clemenciae and L. amethystinus (singly or as each other's sister taxa) and a Central American clade. This Central-American clade presents a clear bipartition between northern (L. viridipallens and L. sybillae) and southern Mesoamerica, which is shared with many other Mesoamerican organisms. Our analyses suggest that L. hemileucus does not belong in the genus Lampornis. While we refrain to apply a time-scale to our data because of the lack of an appropriate calibration, our results indicate that the genus Lampornis predates the uprising of the Panama land-bridge, and that diversification among the isthmian species (L. castaneoventris and L. calolaema) is a very recent event. Our results strongly suggest a local Mesoamerican origin for this genus.

  18. Onboard pattern recognition for autonomous UAV landing

    Science.gov (United States)

    Sung, Chen-Ko; Segor, Florian

    2012-10-01

    The civil security and supervision system AMFIS was developed at the Fraunhofer IOSB as a mobile support system using multiple UAVs for rescue forces in accidents or disasters. To gain a higher level of autonomy for these UAVs, different onboard process chains of image exploitation for tracking landmarks and of control technologies for UAV navigation were implemented and examined to achieve a redundant and reliable UAV precision landing. First experiments have allowed to validate the process chains and to develop a demonstration system for the tracking of landmarks in order to prevent and to minimize any confusion on landing.

  19. Fault Estimation and Control for a Quad-Rotor MAV Using a Polynomial Observer. Part I: Fault Detection

    OpenAIRE

    Flores Colunga, Gerardo Ramon; Aguilar-Sierra, Hipolito; Lozano, Rogelio; Salazar, Sergio

    2014-01-01

    International audience; This work addresses the problem of fault detection and diagnosis (FDD) for a quad-rotor mini aerial vehicle (MAV). Actuator faults are considered on this paper. The basic idea behind the proposed method is to estimate the faults signals using the extended state observers theory. To estimate the faults, a polynomial observer is presented by using the available measurements and know inputs of the system. In order to investigate the observability and diagnosability proper...

  20. Least square based sliding mode control for a quad-rotor helicopter and energy saving by chattering reduction

    Science.gov (United States)

    Sumantri, Bambang; Uchiyama, Naoki; Sano, Shigenori

    2016-01-01

    In this paper, a new control structure for a quad-rotor helicopter that employs the least squares method is introduced. This proposed algorithm solves the overdetermined problem of the control input for the translational motion of a quad-rotor helicopter. The algorithm allows all six degrees of freedom to be considered to calculate the control input. The sliding mode controller is applied to achieve robust tracking and stabilization. A saturation function is designed around a boundary layer to reduce the chattering phenomenon that is a common problem in sliding mode control. In order to improve the tracking performance, an integral sliding surface is designed. An energy saving effect because of chattering reduction is also evaluated. First, the dynamics of the quad-rotor helicopter is derived by the Newton-Euler formulation for a rigid body. Second, a constant plus proportional reaching law is introduced to increase the reaching rate of the sliding mode controller. Global stability of the proposed control strategy is guaranteed based on the Lyapunov's stability theory. Finally, the robustness and effectiveness of the proposed control system are demonstrated experimentally under wind gusts, and are compared with a regular sliding mode controller, a proportional-differential controller, and a proportional-integral-differential controller.

  1. GNSS Software Receiver for UAVs

    DEFF Research Database (Denmark)

    Olesen, Daniel Madelung; Jakobsen, Jakob; von Benzon, Hans-Henrik

    2016-01-01

    This paper describes the current activities of GPS/GNSS Software receiver development at DTU Space. GNSS Software receivers have received a great deal of attention in the last two decades and numerous implementations have already been presented. DTU Space has just recently started development of ...... of our own GNSS software-receiver targeted for mini UAV applications, and we will in in this paper present our current progress and briefly discuss the benefits of Software Receivers in relation to our research interests....

  2. A Real-Time Method to Detect and Track Moving Objects (DATMO from Unmanned Aerial Vehicles (UAVs Using a Single Camera

    Directory of Open Access Journals (Sweden)

    Bruce MacDonald

    2012-04-01

    Full Text Available We develop a real-time method to detect and track moving objects (DATMO from unmanned aerial vehicles (UAVs using a single camera. To address the challenging characteristics of these vehicles, such as continuous unrestricted pose variation and low-frequency vibrations, new approaches must be developed. The main concept proposed in this work is to create an artificial optical flow field by estimating the camera motion between two subsequent video frames. The core of the methodology consists of comparing this artificial flow with the real optical flow directly calculated from the video feed. The motion of the UAV between frames is estimated with available parallel tracking and mapping techniques that identify good static features in the images and follow them between frames. By comparing the two optical flows, a list of dynamic pixels is obtained and then grouped into dynamic objects. Tracking these dynamic objects through time and space provides a filtering procedure to eliminate spurious events and misdetections. The algorithms have been tested with a quadrotor platform using a commercial camera.

  3. Robotic hummingbird: Design of a control mechanism for a hovering flapping wing micro air vehicle

    OpenAIRE

    Karasek, Matej

    2014-01-01

    The use of drones, also called unmanned aerial vehicles (UAVs), is increasing every day. These aircraft are piloted either remotely by a human pilot or completely autonomously by an on-board computer. UAVs are typically equipped with a video camera providing a live video feed to the operator. While they were originally developed mainly for military purposes, many civil applications start to emerge as they become more affordable.Micro air vehicles are a subgroup of UAVs with a size and weight ...

  4. Weed detection by UAV with camera guided landing sequence

    DEFF Research Database (Denmark)

    Dyrmann, Mads

    the built-in GPS, allows for the UAV to be navigated within the field of view of a camera, which is mounted on the landing platform. The camera on the platform determines the UAVs position and orientation from markers printed on the UAV, whereby it can be guided in its landing. The UAV has a camera mounted...

  5. Mini UAV as an improvised air threat

    NARCIS (Netherlands)

    Kraker, K.J. de; Wiel, R.A.N. van de

    2013-01-01

    The use of UAVs for military and law enforcement purposes is increasing dramatically. Simultaneously, possible opponents are also developing UAV capabilities that they may deploy for their purposes. For example, a terrorist may deploy a commercially available model airplane or multicopter with an

  6. Landing spot selection for UAV emergency landing

    NARCIS (Netherlands)

    Eendebak, P.T.; Eekeren, A.W.M. van; Hollander, R.J.M. den

    2013-01-01

    We present a robust method for landing zone selection using obstacle detection to be used for UAV emergency landings. The method is simple enough to allow real-time implementation on a UAV system. The method is able to detect objects in the presence of camera movement and motion parallax. Using the

  7. Landing spot selection for UAV emergency landing

    NARCIS (Netherlands)

    Eendebak, P.T.; Eekeren, A.W.M. van; Hollander, R.J.M. den

    2013-01-01

    We present a robust method for landing zone selection using obstacle detection to be used for UAV emergency landings. The method is simple enough to allow real-time implementation on a UAV system. The method is able to detect objects in the presence of camera movement and motion parallax. Using the

  8. Mini UAV as an improvised air threat

    NARCIS (Netherlands)

    Kraker, K.J. de; Wiel, R.A.N. van de

    2013-01-01

    The use of UAVs for military and law enforcement purposes is increasing dramatically. Simultaneously, possible opponents are also developing UAV capabilities that they may deploy for their purposes. For example, a terrorist may deploy a commercially available model airplane or multicopter with an Im

  9. Persistent Aerial Tracking system for UAVs

    KAUST Repository

    Mueller, Matthias

    2016-12-19

    In this paper, we propose a persistent, robust and autonomous object tracking system for unmanned aerial vehicles (UAVs) called Persistent Aerial Tracking (PAT). A computer vision and control strategy is applied to a diverse set of moving objects (e.g. humans, animals, cars, boats, etc.) integrating multiple UAVs with a stabilized RGB camera. A novel strategy is employed to successfully track objects over a long period, by ‘handing over the camera’ from one UAV to another. We evaluate several state-of-the-art trackers on the VIVID aerial video dataset and additional sequences that are specifically tailored to low altitude UAV target tracking. Based on the evaluation, we select the leading tracker and improve upon it by optimizing for both speed and performance, integrate the complete system into an off-the-shelf UAV, and obtain promising results showing the robustness of our solution in real-world aerial scenarios.

  10. UAV Path Planning using MILP with Experiments

    Directory of Open Access Journals (Sweden)

    Anders Albert

    2017-01-01

    Full Text Available In this paper, we look at the problem of tracking icebergs using multiple Unmanned Aerial Vehicles (UAVs. Our solutions use combinatorial optimization for UAV path planning by formulating a mixed integer linear programing (MILP optimization problem. To demonstrate the approach, we present both a simulation and a practical experiment. The simulation demonstrates the possibilities of the MILP algorithm by constructing a case where three UAVs help a boat make a safe passage through an area with icebergs. Furthermore, we compare the performance of three against a single UAV. In the practical experiment, we take the first step towards full-scale experiments. We run the algorithm on a ground station and use it to set the path for a UAV tracking five simulated icebergs.

  11. Uav Photgrammetric Workflows: a best Practice Guideline

    Science.gov (United States)

    Federman, A.; Santana Quintero, M.; Kretz, S.; Gregg, J.; Lengies, M.; Ouimet, C.; Laliberte, J.

    2017-08-01

    The increasing commercialization of unmanned aerial vehicles (UAVs) has opened the possibility of performing low-cost aerial image acquisition for the documentation of cultural heritage sites through UAV photogrammetry. The flying of UAVs in Canada is regulated through Transport Canada and requires a Special Flight Operations Certificate (SFOC) in order to fly. Various image acquisition techniques have been explored in this review, as well as well software used to register the data. A general workflow procedure has been formulated based off of the literature reviewed. A case study example of using UAV photogrammetry at Prince of Wales Fort is discussed, specifically in relation to the data acquisition and processing. Some gaps in the literature reviewed highlight the need for streamlining the SFOC application process, and incorporating UAVs into cultural heritage documentation courses.

  12. Spatial segregation of the endemic versus non-endemic hummingbird on Robinson Crusoe Island, Chile

    DEFF Research Database (Denmark)

    Vizentin-Bugoni, Jeferson; Sonne, Jesper; Hodum, Peter

    2017-01-01

    Competitive pressure from invasive species tends to have a particularly strong impact on remote islands, and knowledge of such phenomena can be crucial to the conservation of endemic biodiversity. Of the two hummingbird species inhabiting Robinson Crusoe Island, Juan Fernández Archipelago, Chile...

  13. Memory for location and visual cues in white-eared hummingbirds Hylocharis leucotis

    Directory of Open Access Journals (Sweden)

    Guillermo PÉREZ, Carlos LARA, José VICCON-PALE, Martha SIGNORET-POILLON

    2011-08-01

    Full Text Available In nature hummingbirds face floral resources whose availability, quality and quantity can vary spatially and temporally. Thus, they must constantly make foraging decisions about which patches, plants and flowers to visit, partly as a function of the nectar reward. The uncertainty of these decisions would possibly be reduced if an individual could remember locations or use visual cues to avoid revisiting recently depleted flowers. In the present study, we carried out field experiments with white-eared hummingbirds Hylocharis leucotis, to evaluate their use of locations or visual cues when foraging on natural flowers Penstemon roseus. We evaluated the use of spatial memory by observing birds while they were foraging between two plants and within a single plant. Our results showed that hummingbirds prefer to use location when foraging in two plants, but they also use visual cues to efficiently locate unvisited rewarded flowers when they feed on a single plant. However, in absence of visual cues, in both experiments birds mainly used the location of previously visited flowers to make subsequent visits. Our data suggest that hummingbirds are capable of learning and employing this flexibility depending on the faced environmental conditions and the information acquired in previous visits [Current Zoology 57 (4: 468–476, 2011].

  14. Residency in white-eared hummingbirds (Hylocharis leucotis and its effect in territorial contest resolution

    Directory of Open Access Journals (Sweden)

    Verónica Mendiola-Islas

    2016-10-01

    Full Text Available Background Territory owners usually defeat intruders. One explanation for this observation is the uncorrelated asymmetry hypothesis which argues that contests might be settled by an arbitrary convention such as “owners win.” We studied the effect of territorial residency on contest asymmetries in the white-eared hummingbird (Hylocharis leucotis in a fir forest from central Mexico. Methods Twenty white-eared male adult hummingbird territories were monitored during a winter season, recording the territorial behavior of the resident against intruding hummingbirds. The size and quality of the territory were related to the probability that the resident would allow the use of flowers by the intruder. Various generalized models (logistical models were generated to describe the probabilities of victory for each individual resident depending on the different combinations of three predictor variables (territory size, territory quality, and intruder identity. Results In general, small and low quality territory owners tend to prevent conspecific intruders from foraging at a higher rate, while they frequently fail to exclude heterospecific intruders such as the magnificent hummingbird (Eugenes fulgens or the green violetear hummingbird (Colibri thalassinus on any territory size. Our results showed that the identity of the intruder and the size and quality of the territory determined the result of the contests, but not the intensity of defense. Discussion Initially, the rule that “the resident always wins” was supported, since no resident was expelled from its territory during the study. Nevertheless, the resident-intruder asymmetries during the course of a day depended on different factors, such as the size and quality of the territory and, mainly, the identity of the intruders. Our results showed that flexibility observed in contest tactics suggests that these tactics are not fixed but are socially plastic instead and they can be adjusted to

  15. Differential GNSS and Vision-Based Tracking to Improve Navigation Performance in Cooperative Multi-UAV Systems

    Directory of Open Access Journals (Sweden)

    Amedeo Rodi Vetrella

    2016-12-01

    Full Text Available Autonomous navigation of micro-UAVs is typically based on the integration of low cost Global Navigation Satellite System (GNSS receivers and Micro-Electro-Mechanical Systems (MEMS-based inertial and magnetic sensors to stabilize and control the flight. The resulting navigation performance in terms of position and attitude accuracy may not suffice for other mission needs, such as the ones relevant to fine sensor pointing. In this framework, this paper presents a cooperative UAV navigation algorithm that allows a chief vehicle, equipped with inertial and magnetic sensors, a Global Positioning System (GPS receiver, and a vision system, to improve its navigation performance (in real time or in the post processing phase exploiting formation flying deputy vehicles equipped with GPS receivers. The focus is set on outdoor environments and the key concept is to exploit differential GPS among vehicles and vision-based tracking (DGPS/Vision to build a virtual additional navigation sensor whose information is then integrated in a sensor fusion algorithm based on an Extended Kalman Filter. The developed concept and processing architecture are described, with a focus on DGPS/Vision attitude determination algorithm. Performance assessment is carried out on the basis of both numerical simulations and flight tests. In the latter ones, navigation estimates derived from the DGPS/Vision approach are compared with those provided by the onboard autopilot system of a customized quadrotor. The analysis shows the potential of the developed approach, mainly deriving from the possibility to exploit magnetic- and inertial-independent accurate attitude information.

  16. Differential GNSS and Vision-Based Tracking to Improve Navigation Performance in Cooperative Multi-UAV Systems

    Science.gov (United States)

    Vetrella, Amedeo Rodi; Fasano, Giancarmine; Accardo, Domenico; Moccia, Antonio

    2016-01-01

    Autonomous navigation of micro-UAVs is typically based on the integration of low cost Global Navigation Satellite System (GNSS) receivers and Micro-Electro-Mechanical Systems (MEMS)-based inertial and magnetic sensors to stabilize and control the flight. The resulting navigation performance in terms of position and attitude accuracy may not suffice for other mission needs, such as the ones relevant to fine sensor pointing. In this framework, this paper presents a cooperative UAV navigation algorithm that allows a chief vehicle, equipped with inertial and magnetic sensors, a Global Positioning System (GPS) receiver, and a vision system, to improve its navigation performance (in real time or in the post processing phase) exploiting formation flying deputy vehicles equipped with GPS receivers. The focus is set on outdoor environments and the key concept is to exploit differential GPS among vehicles and vision-based tracking (DGPS/Vision) to build a virtual additional navigation sensor whose information is then integrated in a sensor fusion algorithm based on an Extended Kalman Filter. The developed concept and processing architecture are described, with a focus on DGPS/Vision attitude determination algorithm. Performance assessment is carried out on the basis of both numerical simulations and flight tests. In the latter ones, navigation estimates derived from the DGPS/Vision approach are compared with those provided by the onboard autopilot system of a customized quadrotor. The analysis shows the potential of the developed approach, mainly deriving from the possibility to exploit magnetic- and inertial-independent accurate attitude information. PMID:27999318

  17. Influence of normal daytime fat deposition on laboratory measurements of torpor use in territorial versus nonterritorial hummingbirds.

    Science.gov (United States)

    Powers, Donald R; Brown, Alison R; Van Hook, Jessamyn A

    2003-01-01

    Fat deposition and torpor use in hummingbirds exhibiting distinct foraging styles should vary. We predicted that dominant territorial hummingbirds will use torpor less than subordinate nonterritorial species because unrestricted access to energy by territory owners allows for fat storage. Entry into torpor was monitored using open-flow respirometry on hummingbirds allowed to accumulate fat normally during the day. Fat accumulation was measured by solvent fat extraction. Territorial blue-throated hummingbirds (Lampornis clemenciae) had the highest fat accumulation and used torpor only 17% of the time. Fat storage by L. clemenciae averaged 26% of lean dry mass (LDM) in 1995 and 18% in 1996, similar to that measured for other nonmigratory birds. Fat storage by magnificent hummingbirds (Eugenes fulgens; trapliner) and black-chinned hummingbirds (Archilochus alexandri; nectar robber) averaged 19% and 16% of LDM, respectively, and they used torpor frequently (64% and 92% of the time, respectively). All species initiated torpor if total body fat dropped below 10% of LDM, indicating the existence of a torpor threshold. The ability of L. clemenciae to store enough fat to support nighttime metabolism is likely an important benefit of territoriality. Likewise, frequent torpor use by subordinates suggests that natural restrictions to energy intake can impact their energy budget, necessitating energy conservation by use of torpor.

  18. Experimental floral and inflorescence trait manipulations affect pollinator preference and function in a hummingbird-pollinated plant.

    Science.gov (United States)

    Dudash, Michele R; Hassler, Cynthia; Stevens, Peter M; Fenster, Charles B

    2011-02-01

    Controversy is ongoing regarding the importance of pollinator-mediated selection as a source of observed patterns of floral diversity. Although increasing evidence exists of pollinator-mediated selection acting on female reproductive success, there is still limited understanding of pollinator-mediated selection on floral traits via male reproductive success. Here we quantify potential selection by the ruby-throated hummingbird, Archilochus colubris, on four floral traits of hermaphroditic Silene exerted through male floral function. In single trait manipulative experiments we quantified hummingbird visitation preference and/or fluorescent dye (a pollen analog) donation as a function of number of flowers displayed (inflorescence size), height of the floral display (inflorescence height), floral color, and corolla tube length. Hummingbirds preferred to visit larger floral displays and floral displays at greater height, likely representing a general pollinator preference for larger, more visible signals and/or greater rewards. In addition, hummingbirds preferred to visit red flowers, and male function was greater in flowers manipulated to have longer corolla tubes. Selection pressures exerted by hummingbirds on S. virginica floral and inflorescence design through male reproductive success are consistent with the contemporary expression of floral traits of S. virginica relative to related Silene species with different pollinators, and they are consistent with the hummingbird syndrome of traits expressed by S. virginica.

  19. Quantifying hummingbird preference for floral trait combinations: The role of selection on trait interactions in the evolution of pollination syndromes.

    Science.gov (United States)

    Fenster, Charles B; Reynolds, Richard J; Williams, Christopher W; Makowsky, Robert; Dudash, Michele R

    2015-05-01

    Darwin recognized the flower's importance for the study of adaptation and emphasized that the flower's functionality reflects the coordinated action of multiple traits. Here we use a multitrait manipulative approach to quantify the potential role of selection acting on floral trait combinations underlying the divergence and maintenance of three related North American species of Silene (Caryophyllaceae). We artificially generated 48 plant phenotypes corresponding to all combinations of key attractive traits differing among the three Silene species (color, height, inflorescence architecture, flower orientation, and corolla-tube width). We quantified main and interaction effects of trait manipulation on hummingbird visitation preference using experimental arrays. The main effects of floral display height and floral orientation strongly influenced hummingbird visitation, with hummingbirds preferring flowers held high above the ground and vertically to the sky. Hummingbirds also prefer traits in a nonadditive manner as multiple two-way and higher order interaction effects were important predictors of hummingbird visitation. Contemporary trait combinations found in hummingbird pollinated S. virginica are mostly preferred. Our study demonstrates the likelihood of pollination syndromes evolving due to selection on trait combinations and highlights the importance of trait interactions in understanding the evolution of complex adaptations. © 2015 The Author(s).

  20. Commercial UAV operations in civil airspace

    Science.gov (United States)

    Newcome, Laurence R.

    2000-11-01

    The Federal Aviation Administration is often portrayed as the major impediment to unmanned aerial vehicle expansion into civil government and commercial markets. This paper describes one company's record for successfully negotiating the FAA regulations and obtaining authorizations for several types of UAVs to fly commercial reconnaissance missions in civil airspace. The process and criteria for obtaining such authorizations are described. The mishap records of the Pioneer, Predator and Hunter UAVs are examined in regard to their impact on FAA rule making. The paper concludes with a discussion of the true impediments to UAV penetration of commercial markets to date.

  1. Control of a Quadrotor Equipped with a Fixed-wing by Tilting Some of Four Rotors

    Directory of Open Access Journals (Sweden)

    Yoshikazu Nakamura

    2017-03-01

    Full Text Available Abstract—Unmanned aerial vehicles (UAVs are beingexpected to be used for the vegetational observation and theinformation collection of disaster sites. Especially, rotorcraftstypified by helicopters are attractive, because they are able tohover and achieve vertical take-off and landing (VTOL.However, rotorcrafts have a disadvantage that it cannot have along-distance flight, because they fly by the thrust of upwarddirection. Aircrafts with tilt rotors are developed in order toovercome such disadvantages. Such aircrafts can be hovering andtake a VTOL and also a long-distance flight by changing theangle of the rotor. In this research, it is aimed at proposing aVTOL-type UAV with a fixed-wing and four tiltable rotors andcontrolling it.

  2. Diagnoses of hybrid hummingbirds (Aves: Trochilidae). 17. Documentation of the intrageneric hybrid (Archilochus colubris × Archilochus alexandri)

    DEFF Research Database (Denmark)

    Graves, Gary R.; Dittmann, Donna L.; Cardiff, Steven W.

    2016-01-01

    Although the breeding ranges of Archilochus alexandri (Black-chinned Hummingbird) and Archilochus colubris (Ruby throated Hummingbird) are narrowly parapatric in central Texas and central and southern Oklahoma, there have been few reports of hybridization in the literature and no well-documented ......Although the breeding ranges of Archilochus alexandri (Black-chinned Hummingbird) and Archilochus colubris (Ruby throated Hummingbird) are narrowly parapatric in central Texas and central and southern Oklahoma, there have been few reports of hybridization in the literature and no well...

  3. Real time UAV autonomy through offline calculations

    Science.gov (United States)

    Jung, Sunghun

    Two or three dimensional mission plans for a single or a group of hover or fixed wing UAVs are generated. The mission plans can largely be separated into seven main parts. Firstly, the Region Growing algorithm is used to generate a map from 2D or 3D images. Secondly, the map is analyzed to separate each blocks using vertices of blocks and seven filtering steps. Thirdly, the Trapezoidal map algorithm is used to convert the map into a traversability graph. Fourthly, this process also filters out paths that are not traversable. That is, nodes located inside the blocks and too closely located nodes are filtered out. Fifthly, the Dijkstra algorithm is used to calculate the shortest path from a starting point to a goal point. Sixthly, the 1D Optimal Control algorithm is applied to manipulate the velocity and acceleration of the UAVs efficiently. Basically, the UAVs accelerates at one graph node and maintains a constant velocity and decelerates before reaching the next graph node. Lastly, Traveling Salesman Problem Method (TSP) algorithm is used to calculate the shortest path to search the whole region. After this discretization of space and time, it becomes possible to solve several autonomous mission planning problems. We focus on one of the most difficult problems: coordinated search. This is a multiple Traveling Salesman Problem (mTSP). We solve it by decomposing the search region and solving TSPs for each vehicle searching a sub-region. The mTSP is generally used when there are more than one salesman is used. In addition to the four main parts, there are three minor parts which support the main parts. Firstly, Target Detection algorithm is generated to detect a target located near the UAVs' path. A picture of the desired target is inserted into the algorithm before UAVs launch. Using the Scale-Invariant Transform Feature (SIFT) algorithm, a target with a specific shape can be detected. Secondly, Tracking algorithm is generated to manipulate UAVs to follow targets

  4. Indoor Localization of a Quadrotor Based on WSN: A Real-Time Application

    Directory of Open Access Journals (Sweden)

    Jose L. Rullan-Lara

    2013-01-01

    Full Text Available A real‐time localization algorithm is presented in this paper. The algorithm presented here uses an extended Kalman filter and is based on Time Difference Of Arrivals (TDOA measurements of radio signal. The position and velocity of an Unmanned Aerial Vehicle (UAV are successfully estimated in closed‐loop in real‐ time, both in hover and path following flights. Relatively small position errors obtained from the experiments prove the good performance of the proposed algorithm.

  5. Indoor Localization of a Quadrotor Based on WSN: A Real-Time Application

    OpenAIRE

    Jose L. Rullan-Lara; Guillaume Sanahuja; Rogelio Lozano; Sergio Salazar; Ramon Garcia-Hernandez; Ruz-Hernandez, Jose A.

    2013-01-01

    A real‐time localization algorithm is presented in this paper. The algorithm presented here uses an extended Kalman filter and is based on Time Difference Of Arrivals (TDOA) measurements of radio signal. The position and velocity of an Unmanned Aerial Vehicle (UAV) are successfully estimated in closed‐loop in real‐ time, both in hover and path following flights. Relatively small position errors obtained from the experiments prove the good performance of the proposed algorithm.

  6. Indoor Localization of a Quadrotor Based on WSN: A Real-Time Application

    Directory of Open Access Journals (Sweden)

    Jose L. Rullan-Lara

    2013-01-01

    Full Text Available A real-time localization algorithm is presented in this paper. The algorithm presented here uses an extended Kalman filter and is based on Time Difference Of Arrivals (TDOA measurements of radio signal. The position and velocity of an Unmanned Aerial Vehicle (UAV are successfully estimated in closed-loop in real-time, both in hover and path following flights. Relatively small position errors obtained from the experiments prove the good performance of the proposed algorithm.

  7. UAV payload and mission control hardware/software architecture

    OpenAIRE

    Pastor Llorens, Enric; López Rubio, Juan; Royo Chic, Pablo

    2007-01-01

    This paper presents an embedded hardware/software architecture specially designed to be applied on mini/micro Unmanned Aerial Vehicles (UAV). An UAV is low-cost non-piloted airplane designed to operate in D-cube (Dangerous-Dirty-Dull) situations [8]. Many types of UAVs exist today; however with the advent of UAV's civil applications, the class of mini/micro UAVs is emerging as a valid option in a commercial scenario. This type of UAV shares limitations with most computer embedded systems: lim...

  8. Distributed Flight Controls for UAVs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Two novel flight control actuation concepts for UAV applications are proposed for research and development, both of which incorporate shape memory alloy (SMA) wires...

  9. Distributed Flight Controls for UAVs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Two novel flight control actuation concepts for UAV applications are proposed for prototype development, both of which incorporate shape memory alloy (SMA) wires as...

  10. Magnetometer for Balloons and UAVs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I SBIR project will investigate a new, low-cost approach to atomic magnetometry that is suited for operation from UAVs and research balloons. Atomic...

  11. UAV Mission Planning: From Robust to Agile

    NARCIS (Netherlands)

    Evers, L.; Barros, A.I.; Monsuur, H.; Wagelmans, A.

    2015-01-01

    Unmanned Aerial Vehicles (UAVs) are important assets for information gathering in Intelligence Surveillance and Reconnaissance (ISR) missions. Depending on the uncertainty in the planning parameters, the complexity of the mission and its constraints and requirements, different planning methods might

  12. Long Endurance Flight Schemes for UAVs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A method for providing endurance enhancement for unmanned aerial vehicles based on atmospheric phenomena is presented. The proposed method allows the UAV to sense...

  13. Battery Health Management System for Electric UAVs

    Data.gov (United States)

    National Aeronautics and Space Administration — In summary, this paper lays out a novel battery health management technique for application onboard an electric UAV. This technique is also applicable to other...

  14. Light UAV Support Ship (ASW) (LUSSA)

    Science.gov (United States)

    2011-08-01

    IR - Infrared ISR - Intelligence, Surveillance, and Reconnaissance JHU - Johns Hopkins University KB4 - Killer Bee 4, Swift Engineering UAV...Innovation in Ship Design (CISD) used the Northrop Grumman Bat UAV (formally known as the Swift Engineering Killer Bee KB4) to model launch, recovery, and... originally derived from the accuracy and confidence of the pilots. Today, autonomous landing is beginning to become a reliable alternative. Based

  15. UAV Swarm Operational Risk Assessment system

    OpenAIRE

    Marfo, Sariyu; Ehler, Shane; Fields, Ryan; Negron, Jamaries Benitez; Skopak, Shane; Junek, John; Zarzaca, Justin; Perrotta, Robert; Team CQ Alpha; Cohort 311-141A

    2015-01-01

    Approved for public release; distribution is unlimited This paper examines the need for a UAV Swarm Risk Assessment Tool and how it can assist the Navy’s decision makers in assessing risk of UAV swarm threats in littoral environments, near potentially hostile countries, based on the latest intelligence. Human-centered design principles help determine the needs of experienced battle commanders. These needs form the basis of requirements and functional analysis. The system design concept con...

  16. Uav Onboard GPS in Positioning Determination

    Science.gov (United States)

    Tahar, K. N.; Kamarudin, S. S.

    2016-06-01

    The establishment of ground control points is a critical issue in mapping field, especially for large scale mapping. The fast and rapid technique for ground control point's establishment is very important for small budget projects. UAV onboard GPS has the ability to determine the point positioning. The objective of this research is to assess the accuracy of unmanned aerial vehicle onboard global positioning system in positioning determination. Therefore, this research used UAV onboard GPS as an alternative to determine the point positioning at the selected area. UAV is one of the powerful tools for data acquisition and it is used in many applications all over the world. This research concentrates on the error contributed from the UAV onboard GPS during observation. There are several points that have been used to study the pattern of positioning error. All errors were analyzed in world geodetic system 84- coordinate system, which is the basic coordinate system used by the global positioning system. Based on this research, the result of UAV onboard GPS positioning could be used in ground control point establishment with the specific error. In conclusion, accurate GCP establishment could be achieved using UAV onboard GPS by applying a specific correction based on this research.

  17. A Benchmark and Simulator for UAV Tracking

    KAUST Repository

    Mueller, Matthias

    2016-09-16

    In this paper, we propose a new aerial video dataset and benchmark for low altitude UAV target tracking, as well as, a photorealistic UAV simulator that can be coupled with tracking methods. Our benchmark provides the first evaluation of many state-of-the-art and popular trackers on 123 new and fully annotated HD video sequences captured from a low-altitude aerial perspective. Among the compared trackers, we determine which ones are the most suitable for UAV tracking both in terms of tracking accuracy and run-time. The simulator can be used to evaluate tracking algorithms in real-time scenarios before they are deployed on a UAV “in the field”, as well as, generate synthetic but photo-realistic tracking datasets with automatic ground truth annotations to easily extend existing real-world datasets. Both the benchmark and simulator are made publicly available to the vision community on our website to further research in the area of object tracking from UAVs. (https://ivul.kaust.edu.sa/Pages/pub-benchmark-simulator-uav.aspx.). © Springer International Publishing AG 2016.

  18. Electronic Control of Unguided Airborne Vehicle (UAV

    Directory of Open Access Journals (Sweden)

    Mohammed Ahmed Mohammed

    2015-02-01

    Full Text Available The paper deals with building an electronic remote control circuit for Unguided Airborne Vehicle (UAV based on implementing Dual Tone Multiple Frequency decoder ( DTMF .A microcontroller is used in the design to analyze and execute the commands arriving to the UAV . A Liquid Crystal Display (LCD is implemented to show the results during the circuit development and test phase. The control of the UAV is done from the ground using a mobile or a personnel computer (PC supplied with a modem. The DTMF decoder output is connected to the microcontroller which analyzes the commands and accordingly execute them on the control parts in the UAV . The microcontroller issues orders and display the operations on the LCD . The circuit design assumes the presence of an operating GSM network for the transmission of the control commands .The airborne platform model is a small aircraft carrying the electronic circuit on board. Three stepper motors are used as a means of control to the wings, elevators and rudders in the UAV. .The electronic circuit on board the UAV is well protected to ensue safety of the hardware and perfect performance.

  19. Cooperative maneuver enabled UAV relative localization

    Science.gov (United States)

    Strader, Jared

    The ability to localize itself in an environment is essential for any autonomous vehicle. In applications involving multiple Unmanned Aerial Vehicles (UAVs) such as formation flight, surveillance, and mapping, the relative pose of each UAV provides vital information for multiple vehicles to coordinate effectively. The majority of cooperative localization tasks involving multiple UAVs assume the transformation between reference frames, but this information is not always provided in the absence of landmarks or a Global Positioning System (GPS). This thesis presents a method for estimating the relative pose of a pair of UAVs using range-only measurements. In this method, there is no prior information assumed about the relative pose of each UAV. Instead, the trajectories are constrained in order to leverage the circumstances in which the range-only measurements are obtained during flight. To augment this limited information, motion is used to construct a graph of the UAV trajectories using only distance measurements. Using the constructed graph, four potential solutions are derived for the relative pose, and a batch estimate is performed to obtain numerical estimates of each of the four solutions. Using the batch estimate, a cooperative maneuver can be performed in order to obtain a unique solution. The sensitivity to the trajectory and measurement noise are analyzed through a Monte Carlo analysis.

  20. Complete mitochondrial genome of the versicoloured emerald hummingbird Amazilia versicolor, a polymorphic species.

    Science.gov (United States)

    Prosdocimi, Francisco; Souto, Helena Magarinos; Ruschi, Piero Angeli; Furtado, Carolina; Jennings, W Bryan

    2016-09-01

    The genome of the versicoloured emerald hummingbird (Amazilia versicolor) was partially sequenced in one-sixth of an Illumina HiSeq lane. The mitochondrial genome was assembled using MIRA and MITObim software, yielding a circular molecule of 16,861 bp in length and deposited in GenBank under the accession number KF624601. The mitogenome contained 13 protein-coding genes, 22 transfer tRNAs, 2 ribosomal RNAs and 1 non-coding control region. The molecule was assembled using 21,927 sequencing reads of 100 bp each, resulting in ∼130 × coverage of uniformly distributed reads along the genome. This is the forth mitochondrial genome described for this highly diverse family of birds and may benefit further phylogenetic, phylogeographic, population genetic and species delimitation studies of hummingbirds.

  1. Low Dimensional Analysis of Wing Surface Morphology in Hummingbird Free Flight

    Science.gov (United States)

    Shallcross, Gregory; Ren, Yan; Liu, Geng; Dong, Haibo; Tobalske, Bret

    2015-11-01

    Surface morphing in flapping wings is a hallmark of bird flight. In current work, the role of dynamic wing morphing of a free flying hummingbird is studied in detail. A 3D image-based surface reconstruction method is used to obtain the kinematics and deformation of hummingbird wings from high-quality high-speed videos. The observed wing surface morphing is highly complex and a number of modeling methods including singular value decomposition (SVD) are used to obtain the fundamental kinematical modes with distinct motion features. Their aerodynamic roles are investigated by conducting immersed-boundary-method based flow simulations. The results show that the chord-wise deformation modes play key roles in the attachment of leading-edge vortex, thus improve the performance of the flapping wings. This work is supported by NSF CBET-1313217 and AFOSR FA9550-12-1-0071.

  2. Development of Cloud-Based UAV Monitoring and Management System.

    Science.gov (United States)

    Itkin, Mason; Kim, Mihui; Park, Younghee

    2016-11-15

    Unmanned aerial vehicles (UAVs) are an emerging technology with the potential to revolutionize commercial industries and the public domain outside of the military. UAVs would be able to speed up rescue and recovery operations from natural disasters and can be used for autonomous delivery systems (e.g., Amazon Prime Air). An increase in the number of active UAV systems in dense urban areas is attributed to an influx of UAV hobbyists and commercial multi-UAV systems. As airspace for UAV flight becomes more limited, it is important to monitor and manage many UAV systems using modern collision avoidance techniques. In this paper, we propose a cloud-based web application that provides real-time flight monitoring and management for UAVs. For each connected UAV, detailed UAV sensor readings from the accelerometer, GPS sensor, ultrasonic sensor and visual position cameras are provided along with status reports from the smaller internal components of UAVs (i.e., motor and battery). The dynamic map overlay visualizes active flight paths and current UAV locations, allowing the user to monitor all aircrafts easily. Our system detects and prevents potential collisions by automatically adjusting UAV flight paths and then alerting users to the change. We develop our proposed system and demonstrate its feasibility and performances through simulation.

  3. 四旋翼飞行器逃逸算法的实现%Implementation of escape behavior algorithm for quadrotor aircraft

    Institute of Scientific and Technical Information of China (English)

    张金学; 掌明

    2013-01-01

    提出了四旋翼飞行器的逃逸行为算法。逃逸行为算法可以降低无人直升机与动态障碍物碰撞的可能性。通过在算法中实现群粒子的相对定位给出了四转子的移动和约束模型。为四转子的实际模型设计了控制器,该控制器根据规定的轨迹计算出每个螺旋桨转子的速度。通过仿真和对真实的派诺特 AR.Drone飞行器的测试验证了该算法的功能。%An escape behavior algorithm for quadrotor aircraft is proposed,which can decrease the possibility of collision of unmanned helicopters with dynamic obstacles. The models of the quadrotor movement and the constraints are given by relative localization of swarm particles. The controller for the real model of the quadrotor is designed and it calculates the speed of each propeller of quadrotors according to a prescribed trajectory. The functionality of this algorithm is testified by using simulations and testing on a flying vehicle platform-Parrot AR.Drone.

  4. The power of feeder-mask respirometry as a method for examining hummingbird energetics.

    Science.gov (United States)

    Welch, Kenneth C

    2011-03-01

    Many birds spend important portions of their time and energy flying. For this reason, quantification of metabolic rates during flight is of crucial importance to understanding avian energy balance. Measurement of organismal gas exchange rates using a mask enclosing the whole head or respiratory orifices has served as an important tool for studying animal energetics because it can free the rest of the body, permitting movement. Application of so-called "mask respirometry" to the study of avian forward flight energetics presents unique challenges because birds must be tethered to gas analysis equipment thus typically necessitating use of a wind tunnel. Resulting potential alterations to a study organism's behaviour, physiology, and aerodynamics have made interpretation of such studies contentious. In contrast, the study of hovering flight energetics in hummingbirds using a specialized form of mask respirometry is comparatively easy and can be done without a wind tunnel. Small size, hovering flight, and a nectarivorous diet are characteristics shared by all hummingbird species that make these birds ideally suited for this approach. Specifically, nectar feeders are modified to function as respirometry masks hummingbirds voluntarily respire into when hover-feeding. Feeder-mask based respirometry has revealed some of the highest vertebrate metabolic rates in hovering hummingbirds. In this review I discuss techniques for the successful measurement of metabolic rate using feeder-mask respirometry. I also emphasize how this technique has been used to address fundamental questions regarding avian flight energetics such as capacities for fuel use and mechanisms by which ecology, behaviour and energy balance are linked. Copyright © 2010 Elsevier Inc. All rights reserved.

  5. Myosin heavy-chain isoforms in the flight and leg muscles of hummingbirds and zebra finches.

    Science.gov (United States)

    Velten, Brandy P; Welch, Kenneth C

    2014-06-01

    Myosin heavy chain (MHC) isoform complement is intimately related to a muscle's contractile properties, yet relatively little is known about avian MHC isoforms or how they may vary with fiber type and/or the contractile properties of a muscle. The rapid shortening of muscles necessary to power flight at the high wingbeat frequencies of ruby-throated hummingbirds and zebra finches (25-60 Hz), along with the varied morphology and use of the hummingbird hindlimb, provides a unique opportunity to understand how contractile and morphological properties of avian muscle may be reflected in MHC expression. Isoforms of the hummingbird and zebra finch flight and hindlimb muscles were electrophoretically separated and compared with those of other avian species representing different contractile properties and fiber types. The flight muscles of the study species operate at drastically different contraction rates and are composed of different histochemically defined fiber types, yet each exhibited the same, single MHC isoform corresponding to the chicken adult fast isoform. Thus, despite quantitative differences in the contractile demands of flight muscles across species, this isoform appears necessary for meeting the performance demands of avian powered flight. Variation in flight muscle contractile performance across species may be due to differences in the structural composition of this conserved isoform and/or variation within other mechanically linked proteins. The leg muscles were more varied in their MHC isoform composition across both muscles and species. The disparity in hindlimb MHC expression between hummingbirds and the other species highlights previously observed differences in fiber type composition and thrust production during take-off. Copyright © 2014 the American Physiological Society.

  6. Are hummingbirds facultatively ammonotelic? Nitrogen excretion and requirements as a function of body size.

    Science.gov (United States)

    McWhorter, Todd J; Powers, Donald R; Martínez Del Rio, Carlos

    2003-01-01

    Most birds are uricotelic. An exception to this rule may be nectar-feeding birds, which excrete significant amounts of ammonia under certain conditions. Although ammonia is toxic, because it is highly water soluble its excretion may be facilitated in animals that ingest and excrete large amounts of water. Bird-pollinated plants secrete carbohydrate- and water-rich floral nectars that contain exceedingly little protein. Thus, nectar-feeding birds are faced with the dual challenge of meeting nitrogen requirements while disposing of large amounts of water. The peculiar diet of nectar-feeding birds suggests two hypotheses: (1) these birds must have low protein requirements, and (2) when they ingest large quantities of water their primary nitrogen excretion product may be ammonia. To test these hypotheses, we measured maintenance nitrogen requirements (MNR) and total endogenous nitrogen losses (TENL) in three hummingbird species (Archilochus alexandri, Eugenes fulgens, and Lampornis clemenciae) fed on diets with varying sugar, protein, and water content. We also quantified the form in which the by-products of nitrogen metabolism were excreted. The MNR and TENL of the hummingbirds examined were exceptionally low. However, no birds excreted more than 50% of nitrogen as ammonia or more nitrogen as ammonia than urates. Furthermore, ammonia excretion was not influenced by either water or protein intake. The smallest species (A. alexandri) excreted a significantly greater proportion (>25%) of their nitrogenous wastes as ammonia than the larger hummingbirds ( approximately 4%). Our results support the hypothesis that nectar-feeding birds have low protein requirements but cast doubt on the notion that they are facultatively ammonotelic. Our data also hint at a possible size-dependent dichotomy in hummingbirds, with higher ammonia excretion in smaller species. Differences in proportionate water loads and/or postrenal modification of urine may explain this dichotomy.

  7. Phylogeography and population genetics of the Amethyst-throated Hummingbird (Lampornis amethystinus).

    Science.gov (United States)

    Cortés-Rodríguez, Nandadevi; Hernández-Baños, Blanca E; Navarro-Sigüenza, Adolfo G; Townsend Peterson, A; García-Moreno, Jaime

    2008-07-01

    We analyzed mitochondrial DNA sequence variation across 69 Amethyst-throated Hummingbirds (Lampornis amethystinus), comparing with samples of related taxa. Although this group shows discrete phenotypic variation in throat color among populations in Oaxaca and Guerrero (Mexico), the only phylogeographic structure observed was between phenotypically similar populations north and south of the Isthmus of Tehuantepec. As such, it appears that throat color variation is of recent origin and likely based only on minor genetic differences.

  8. Hummingbirds as vectors of fungal spores in Moussonia deppeana (Gesneriaceae): taking advantage of a mutualism?

    Science.gov (United States)

    Lara, Carlos; Ornelas, Juan Francisco

    2003-02-01

    Hummingbirds act as vectors of Fusarium moniliforme spores on protandrous flowers of Moussonia deppeana. The resulting interactions between the pathogen and plant-pollinator interactions were investigated in a 4-yr study to determine the pathogen's impact on host flowering phenology, flower longevity, nectar production, and fruit and seed production. We also evaluated hummingbird behavior on healthy and diseased plants and its effectiveness on spore transmission. Individual plants expressed the disease from year to year, and new infected individuals were detected every year. A fraction of the flowers in a plant expressed the disease, and this varied among and within years. Diseased plants produced more inflorescences, buds, and open healthy flowers than did healthy plants. Further, diseased plants bore proportionally fewer pistillate flowers than did healthy plants when considering only healthy flowers. Neither nectar nor fruit production differed between healthy and diseased plants, but healthy plants produced more seeds. Infected flowers were retained longer than uninfected ones, producing an additional 2 mg · μL(-1) · flower(-1) of nectar sugar. Hummingbirds visited more flowers on diseased plants than they did on healthy plants, regardless of number and sexual phase. Most pollen and spores were deposited within plants. These behavioral outcomes may promote geitonogamy and limit fungal spore mixing.

  9. Hummingbird with modern feathering: an exceptionally well-preserved Oligocene fossil from southern France

    Science.gov (United States)

    Louchart, Antoine; Tourment, Nicolas; Carrier, Julie; Roux, Thierry; Mourer-Chauviré, Cécile

    2008-02-01

    Hummingbirds (Trochilidae) today have an exclusively New World distribution, but their pre-Pleistocene fossil record comes from Europe only. In this study, we describe an exceptionally preserved fossil hummingbird from the early Oligocene of southeastern France. The specimen is articulated, with a completely preserved beak and feathering. Osteological characters allow to identify it as Eurotrochilus sp. This genus is a stem group representative of Trochilidae and was recently described from the early Oligocene of southern Germany. The new fossil reveals that these European Trochilidae were remarkably modern in size, skeletal proportions and the shape of the wing, tail and beak and hyoid bones. These features confirm the early acquisition of the abilities of hovering and nectarivory in hummingbirds, probably before the Oligocene. In several morphological characteristics, they resemble members of the ‘true hummingbirds’ (subfamily Trochilinae) and differ from hermits (Phaethornithinae). These features, which include a short and square tail and a moderately long, almost straight beak, appear to be primitive within the family Trochilidae.

  10. The Rufous Hummingbird in hovering flight -- full-body 3D immersed boundary simulation

    Science.gov (United States)

    Ferreira de Sousa, Paulo; Luo, Haoxiang; Bocanegra Evans, Humberto

    2009-11-01

    Hummingbirds are an interesting case study for the development of micro-air vehicles since they combine the high flight stability of insects with the low metabolic power per unit of body mass of bats, during hovering flight. In this study, simulations of a full-body hummingbird in hovering flight were performed at a Reynolds number around 3600. The simulations employ a versatile sharp-interface immersed boundary method recently enhanced at our lab that can treat thin membranes and solid bodies alike. Implemented on a Cartesian mesh, the numerical method allows us to capture the vortex dynamics of the wake accurately and efficiently. The whole-body simulation will allow us to clearly identify the three general patterns of flow velocity around the body of the hummingbird referred in Altshuler et al. (Exp Fluids 46 (5), 2009). One focus of the current study is to understand the interaction between the wakes of the two wings at the end of the upstroke, and how the tail actively defects the flow to contribute to pitch stability. Another focus of the study will be to identify the pair of unconnected loops underneath each wing.

  11. Hummingbirds control turning velocity using body orientation and turning radius using asymmetrical wingbeat kinematics.

    Science.gov (United States)

    Read, Tyson J G; Segre, Paolo S; Middleton, Kevin M; Altshuler, Douglas L

    2016-03-01

    Turning in flight requires reorientation of force, which birds, bats and insects accomplish either by shifting body position and total force in concert or by using left-right asymmetries in wingbeat kinematics. Although both mechanisms have been observed in multiple species, it is currently unknown how each is used to control changes in trajectory. We addressed this problem by measuring body and wingbeat kinematics as hummingbirds tracked a revolving feeder, and estimating aerodynamic forces using a quasi-steady model. During arcing turns, hummingbirds symmetrically banked the stroke plane of both wings, and the body, into turns, supporting a body-dependent mechanism. However, several wingbeat asymmetries were present during turning, including a higher and flatter outer wingtip path and a lower more deviated inner wingtip path. A quasi-steady analysis of arcing turns performed with different trajectories revealed that changes in radius were associated with asymmetrical kinematics and forces, and changes in velocity were associated with symmetrical kinematics and forces. Collectively, our results indicate that both body-dependent and -independent force orientation mechanisms are available to hummingbirds, and that these kinematic strategies are used to meet the separate aerodynamic challenges posed by changes in velocity and turning radius.

  12. Network Centric Transponders for Airspace Integration of UAVs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The need for a small, lightweight, remotely-operable transponder for UAVs is identified. This would allow integration of UAVs into the national airspace while...

  13. Review of the current state of UAV regulations

    NARCIS (Netherlands)

    Stöcker, Elvira Claudia; Bennett, Rohan; Nex, Francesco; Gerke, Markus; Zevenbergen, Jaap

    2017-01-01

    UAVs-unmanned aerial vehicles-facilitate data acquisition at temporal and spatial scales that still remain unachievable for traditional remote sensing platforms. However, current legal frameworks that regulate UAVs present significant barriers to research and development. To highlight the

  14. UAV's als vliegend knooppunt in het militaire C2 netwerk

    NARCIS (Netherlands)

    Veen, E.M. van der

    2003-01-01

    Gedurende de laatste jaren zijn UAVs doorgebroken in toepassing, media en wetenschap. Deze doorbraak is vooral tot stand gebracht door de breed uitgemeten inzet van militaire UAVs in recente militaire operaties. Hierbij betrof het zowel de inzet van UAVs voor verkenning, als de incidentele inzet van

  15. Diverse Planning for UAV Control and Remote Sensing.

    Science.gov (United States)

    Tožička, Jan; Komenda, Antonín

    2016-12-21

    Unmanned aerial vehicles (UAVs) are suited to various remote sensing missions, such as measuring air quality. The conventional method of UAV control is by human operators. Such an approach is limited by the ability of cooperation among the operators controlling larger fleets of UAVs in a shared area. The remedy for this is to increase autonomy of the UAVs in planning their trajectories by considering other UAVs and their plans. To provide such improvement in autonomy, we need better algorithms for generating alternative trajectory variants that the UAV coordination algorithms can utilize. In this article, we define a novel family of multi-UAV sensing problems, solving task allocation of huge number of tasks (tens of thousands) to a group of configurable UAVs with non-zero weight of equipped sensors (comprising the air quality measurement as well) together with two base-line solvers. To solve the problem efficiently, we use an algorithm for diverse trajectory generation and integrate it with a solver for the multi-UAV coordination problem. Finally, we experimentally evaluate the multi-UAV sensing problem solver. The evaluation is done on synthetic and real-world-inspired benchmarks in a multi-UAV simulator. Results show that diverse planning is a valuable method for remote sensing applications containing multiple UAVs.

  16. Diverse Planning for UAV Control and Remote Sensing

    Directory of Open Access Journals (Sweden)

    Jan Tožička

    2016-12-01

    Full Text Available Unmanned aerial vehicles (UAVs are suited to various remote sensing missions, such as measuring air quality. The conventional method of UAV control is by human operators. Such an approach is limited by the ability of cooperation among the operators controlling larger fleets of UAVs in a shared area. The remedy for this is to increase autonomy of the UAVs in planning their trajectories by considering other UAVs and their plans. To provide such improvement in autonomy, we need better algorithms for generating alternative trajectory variants that the UAV coordination algorithms can utilize. In this article, we define a novel family of multi-UAV sensing problems, solving task allocation of huge number of tasks (tens of thousands to a group of configurable UAVs with non-zero weight of equipped sensors (comprising the air quality measurement as well together with two base-line solvers. To solve the problem efficiently, we use an algorithm for diverse trajectory generation and integrate it with a solver for the multi-UAV coordination problem. Finally, we experimentally evaluate the multi-UAV sensing problem solver. The evaluation is done on synthetic and real-world-inspired benchmarks in a multi-UAV simulator. Results show that diverse planning is a valuable method for remote sensing applications containing multiple UAVs.

  17. Development of Open source-based automatic shooting and processing UAV imagery for Orthoimage Using Smart Camera UAV

    OpenAIRE

    Park, J. W.; H. H. Jeong; Kim, J. S.; Choi, C U

    2016-01-01

    Recently, aerial photography with unmanned aerial vehicle (UAV) system uses UAV and remote controls through connections of ground control system using bandwidth of about 430 MHz radio Frequency (RF) modem. However, as mentioned earlier, existing method of using RF modem has limitations in long distance communication. The Smart Camera equipments’s LTE (long-term evolution), Bluetooth, and Wi-Fi to implement UAV that uses developed UAV communication module system carried out the close aerial ph...

  18. A comprehensive analysis of a Light-UAVS design

    OpenAIRE

    Olivart Llop, Josep Miquel

    2008-01-01

    The actual situation of the UAVS market is analyzed, putting special attention in the Light- UAVS segment. It is also reviewed the actual regulation of UAVS (or the lack of it) in the United States and in Europe. The MH2000, a Light-UAVS created by MAVTech s.r.l. under the directions of the Politecnico di Torino is actually being used by the non-profit association ITHACA for photogrammetric purposes. This model has been taken as an example of the Light-UAVS segment and it ha...

  19. UAVs for Glacier Mapping: Lessons Learned

    Science.gov (United States)

    McKinnon, T.; McKinnon, K. A.; Anderson, B.

    2014-12-01

    Using two different unmanned aerial vehicles (UAVs) mounted with cameras, we created a digital elevation model (DEM) of the lower 12 km^2 of Tasman Glacier, South Island, New Zealand in March 2014. The project served primarily as a proof-of-concept, and here we discuss the lessons learned, emphasizing the practical, logistical, and flight issues. We tested two different fixed-wing airframes -- a twin-boom tradition and flying wing; two different camera types, both consumer-grade RGB; and various combinations of RC and telemetry radios. We used both commercial and open-source photogrammetry software to create the mosaic and DEM imagery. Some of the most critical UAV-specific issues are: access to a launch/landing site, adequate landing zones, range, airspace contention with manned aircraft, and hardware reliability. While UAVs provide a lower-cost method for photogrammetry access, it also comes with a unique set of challenges.

  20. DESIGN AND FABRICATION OF TWINROTOR UAV

    Directory of Open Access Journals (Sweden)

    Shlok Agarwal

    2013-11-01

    Full Text Available There have been many advancements in the field of aerospace and avionics. Scientists have increasingly started to focus on VTOL (vertical take - off and landing aircrafts. We have built a miniature VTOL twinrotor UAV. UAVs have begun to grab a lot of attention these days due to its numerous applications such as surveillance and relief. Twinrotor is a kind of a helicopter having two main propellers instead of one and no tail fin. All three important motion of the aircraft i.e. roll, pitch, yaw are controlled by thrust vectoring using servo motors and changing the magnitude of thrust using electronics speed controllers. The paper deals with the design of a basic UAV based on application and the construction keeping in mind the different concepts that govern its motion.

  1. Attitude Estimation for Quad-Rotor Aircraft%四旋翼飞行器姿态估计方法

    Institute of Scientific and Technical Information of China (English)

    饶康麒; 刘小明; 陈万春

    2015-01-01

    To the measurement error caused by sensor due to rotor vibration in attitude estimation for quad-rotor aircraft,the data measured by accelerometer and gyroscope are fused through a Kalman filter method,to improve the accuracy of attitude estimation,reduce the noise caused by carrier vibration and solve the gyro drift problem.First,the error types of inertial devices were analyzed,and then a three-DOF ( degree of freedom) system model was established,simulation analysis was also made through Matlab.Finally,the feasibility of this method was verified by using an experimental bench with propellers.Experimental results showed that the attitude estimation error was within 2 °and was not accumulated over time,basically meeting the requirements of attitude estimation for quad-rotor aircraft,such as real-time performance,low cost and high precision.This method could be successfully applied to the attitude control for quad-rotor aircraft,which can suppress the noise interference,and create a good condition for stable autonomous flight.%针对四旋翼飞行器姿态估计中传感器由于旋翼振动带来的测量误差,通过卡尔曼滤波方法融合加速度计和陀螺仪的测量数据来提高姿态估计精度,减少因载体振动带来的噪声并解决陀螺漂移问题。先分析了惯性器件误差类型,然后建立了三自由度的系统模型并用Matlab进行仿真分析,再利用带有螺旋桨的实验台验证方法的可行性。实验结果表明,姿态估计误差在2°以内且没有随时间的增长而增大,基本满足四旋翼飞行器姿态估计的实时性、廉价性、高精度等要求,该方法可以成功应用于四旋翼飞行器的姿态控制,抑制噪声干扰,为稳定的自主飞行创造条件。

  2. Preferential nectar robbing of flowers with long corollas: experimental studies of two hummingbird species visiting three plant species.

    Science.gov (United States)

    Lara, Carlos; Ornelas, Juan

    2001-07-01

    Long flower tubes have been traditionally viewed as the result of coevolution between plants and specialized, legitimate, long billed-pollinators. However, nectar robbers may have played a role in selection acting on corolla length. This study evaluated whether hummingbirds are more likely to rob flowers with longer corollas from which they cannot efficiently extract nectar with legitimate visits. We compared two hummingbird species with similar bill lengths (Lampornis amethystinus and Colibri thalassinus) visiting floral arrays of artificial flowers with exaggerated corolla lengths, and also evaluated how the birds extract nectar rewards from medium to long corollas of three hummingbird-pollinated plants (Salvia mexicana, S. iodantha and Ipomoea hederifolia). The consequences of foraging for plant fitness were evaluated in terms of seed production per flower. Variation in seed production after legitimate visits of hummingbird-pollinated plants was mostly explained by differences in pollinator effectiveness. Seed production did not increase with the number of legitimate visits to a flower, except in I. hederifolia. We found that birds were more likely to rob both artificial and natural flowers with long corolla tubes. Nectar robbing was not observed on short-corolla flowers of Salvia spp., but robbing negatively affected seed production of long-tubed flowers of I. hederifolia. Significant differences between hummingbird species in the use of this behavior were observed, but males and females behaved alike. We suggest that short-billed hummingbirds with enlarged bill serrations (the edge of both tomia finely toothed) may have an advantage in illegitimately feeding at long-corolla flowers. This raises the possibility of counter-selection on increasing corolla length by nectar robbers.

  3. A system of UAV application in indoor environment

    Directory of Open Access Journals (Sweden)

    Yohanes Khosiawan

    2016-01-01

    Full Text Available In recent years, there has been an increased demand in the use of multiple unmanned aerial vehicles (UAVs in indoor environments such as material handling task in a manufacturing environment and plant/environment monitoring task in a greenhouse. However, there is a lack of work reported on this topic. This paper presents a detailed study on several UAV systems and UAV scheduling systems. It is followed by a proposed system of UAV application in indoor environment, which comprises components of UAV system addressed in detail; focused on scheduler as the heart of operations. Consequently, system architecture of UAV scheduling system is presented and the framework of scheduler component is included. Scheduler component works in a phased manner to provide a systematic abstraction and achieve an efficient computation time. This study serves as a reference guide for UAV application in indoor environment.

  4. The ARM unpiloted aerospace vehicle (UAV) program

    Energy Technology Data Exchange (ETDEWEB)

    Sowle, D. [Mission Research Corporation, Santa Barbara, CA (United States)

    1995-09-01

    Unmanned aerospace vehicles (UAVs) are an important complement to the DOE`s Atmospheric Radiation Measurement (ARM) Program. ARM is primarily a ground-based program designed to extensively quantify the radiometric and meteorological properties of an atmospheric column. There is a need for airborne measurements of radiative profiles, especially flux at the tropopause, cloud properties, and upper troposphere water vapor. There is also a need for multi-day measurements at the tropopause; for example, in the tropics, at 20 km for over 24 hours. UAVs offer the greatest potential for long endurance at high altitudes and may be less expensive than piloted flights. 2 figs.

  5. Common Operating Picture: UAV Security Study

    Science.gov (United States)

    2004-01-01

    This initial communication security study is a top-level assessment of basic security issues related to the operation of Unmanned Aerial Vehicles (UAVs) in the National Airspace System (NAS). Security considerations will include information relating to the use of International Civil Aviation Organization (ICAO) Aeronautical Telecommunications Network (ATN) protocols and applications identifying their maturity, as well as the use of IPV4 and a version of mobile IPV6. The purpose of this assessment is to provide an initial analysis of the security implications of introducing UAVs into the NAS.

  6. CLASSICAL PHOTOGRAMMETRY AND UAV – SELECTED ASCPECTS

    Directory of Open Access Journals (Sweden)

    S. Mikrut

    2016-06-01

    Full Text Available The UAV technology seems to be highly future-oriented due to its low costs as compared to traditional aerial images taken from classical photogrammetry aircrafts. The AGH University of Science and Technology in Cracow - Department of Geoinformation, Photogrammetry and Environmental Remote Sensing focuses mainly on geometry and radiometry of recorded images. Various scientific research centres all over the world have been conducting the relevant research for years. The paper presents selected aspects of processing digital images made with the UAV technology. It provides on a practical example a comparison between a digital image taken from an airborne (classical height, and the one made from an UAV level. In his research the author of the paper is trying to find an answer to the question: to what extent does the UAV technology diverge today from classical photogrammetry, and what are the advantages and disadvantages of both methods? The flight plan was made over the Tokarnia Village Museum (more than 0.5 km2 for two separate flights: the first was made by an UAV - System FT-03A built by FlyTech Solution Ltd. The second was made with the use of a classical photogrammetric Cesna aircraft furnished with an airborne photogrammetric camera (Ultra Cam Eagle. Both sets of photographs were taken with pixel size of about 3 cm, in order to have reliable data allowing for both systems to be compared. The project has made aerotriangulation independently for the two flights. The DTM was generated automatically, and the last step was the generation of an orthophoto. The geometry of images was checked under the process of aerotriangulation. To compare the accuracy of these two flights, control and check points were used. RMSE were calculated. The radiometry was checked by a visual method and using the author's own algorithm for feature extraction (to define edges with subpixel accuracy. After initial pre-processing of data, the images were put together, and

  7. Classical Photogrammetry and Uav - Selected Ascpects

    Science.gov (United States)

    Mikrut, S.

    2016-06-01

    The UAV technology seems to be highly future-oriented due to its low costs as compared to traditional aerial images taken from classical photogrammetry aircrafts. The AGH University of Science and Technology in Cracow - Department of Geoinformation, Photogrammetry and Environmental Remote Sensing focuses mainly on geometry and radiometry of recorded images. Various scientific research centres all over the world have been conducting the relevant research for years. The paper presents selected aspects of processing digital images made with the UAV technology. It provides on a practical example a comparison between a digital image taken from an airborne (classical) height, and the one made from an UAV level. In his research the author of the paper is trying to find an answer to the question: to what extent does the UAV technology diverge today from classical photogrammetry, and what are the advantages and disadvantages of both methods? The flight plan was made over the Tokarnia Village Museum (more than 0.5 km2) for two separate flights: the first was made by an UAV - System FT-03A built by FlyTech Solution Ltd. The second was made with the use of a classical photogrammetric Cesna aircraft furnished with an airborne photogrammetric camera (Ultra Cam Eagle). Both sets of photographs were taken with pixel size of about 3 cm, in order to have reliable data allowing for both systems to be compared. The project has made aerotriangulation independently for the two flights. The DTM was generated automatically, and the last step was the generation of an orthophoto. The geometry of images was checked under the process of aerotriangulation. To compare the accuracy of these two flights, control and check points were used. RMSE were calculated. The radiometry was checked by a visual method and using the author's own algorithm for feature extraction (to define edges with subpixel accuracy). After initial pre-processing of data, the images were put together, and shown side by side

  8. Design and Development of a Class of Rotorcraft-based UAV

    OpenAIRE

    Gyou Beom Kim; Trung Kien Nguyen; Agus Budiyono; Jung Keun Park; Kwang Joon Yoon; Jinok Shin

    2013-01-01

    We discuss the development of a mini‐quadrotor system and coaxial quadrotor system for indoor and outdoor applications. The attitude control system consists of a stability augmentation system and a modern control approach. To perform an experimental flight test, a PID controller is used to validate our aerodynamic modelling and basic electronics hardware is developed in a simple configuration. We use a low‐cost 100 Hz AHRS for inertial sensing, infrared (IR) sensors for horizontal ranging, an...

  9. Design/Development of Mini/Micro Air Vehicles through Modelling and Simulation: Case of an Autonomous Quadrotor

    Directory of Open Access Journals (Sweden)

    Nitin K. Gupta

    2011-07-01

    Full Text Available Normal 0 MicrosoftInternetExplorer4 Design and development of an autonomous quadrotor micro aerial vehicle is undertaken following a systematic approach. A fairly detailed model was constructed and simulations were then carried out with the purpose of refining the baseline design, building a controller, and testing the flying qualities of the vehicle on a ground-based flight simulator. Following this, a smooth transition to rig and flight testing has been enabled in a cost- and time-effective manner, meeting all the design requirements.Defence Science Journal, 2011, 61(4, pp.337-345, DOI:http://dx.doi.org/10.14429/dsj.61.1086

  10. A New Optimal Control Algorithm for Quad-rotor Helicopter with State Constraints via Sliding-mode Control

    Directory of Open Access Journals (Sweden)

    Zhao Jing

    2015-01-01

    Full Text Available This paper proposes a strategy of a new optimal sliding-mode control for flight control system with state constraints so that the system guarantees the optimal performance index. Besides, the strategy ensures strong robustness to the internal parametric uncertainty and the external disturbances. In order to have fast transient response speed as well as good tracking accuracy, the integral of the time multiplied by the absolute displacement tracking error is introduced as the performance index. By analyzing the state constraints which are specifically the velocity tracking error constraint and the acceleration tracking error constraint, and the performance index, the parameters of sliding-mode surface and control law are obtained. Finally, the authors conduct the semi physical simulation on Qball-X4 quad-rotor helicopter, showing the effectiveness of the proposed strategy.

  11. Pollination ecology of two species of Elleanthus (Orchidaceae): novel mechanisms and underlying adaptations to hummingbird pollination.

    Science.gov (United States)

    Nunes, C E P; Amorim, F W; Mayer, J L S; Sazima, M

    2016-01-01

    Relationships among floral biology, floral micromorphology and pollinator behaviour in bird-pollinated orchids are important issues to understand the evolution of the huge flower diversity within Orchidaceae. We aimed to investigate floral mechanisms underlying the interaction with pollinators in two hummingbird-pollinated orchids occurring in the Atlantic forest. We assessed floral biology, nectar traits, nectary and column micromorphologies, breeding systems and pollinators. In both species, nectar is secreted by lip calli through spaces between the medial lamellar surfaces of epidermal cells. Such a form of floral nectar secretion has not been previously described. Both species present functional protandry and are self-compatible yet pollinator-dependent. Fruit set in hand-pollination experiments was more than twice that under natural conditions, evidencing pollen limitation. The absence of fruit set in interspecific crosses suggests the existence of post-pollination barriers between these sympatric co-flowering species. In Elleanthus brasiliensis, fruits resulting from cross-pollination and natural conditions were heavier than those resulting from self-pollination, suggesting advantages to cross-pollination. Hummingbirds pollinated both species, which share at least one pollinator species. Species differences in floral morphologies led to distinct pollination mechanisms. In E. brasiliensis, attachment of pollinarium to the hummingbird bill occurs through a lever apparatus formed by an appendage in the column, another novelty to our knowledge of orchid pollination. In E. crinipes, pollinarium attachment occurs by simple contact with the bill during insertion into the flower tube, which fits tightly around it. The novelties described here illustrate the overlooked richness in ecology and morphophysiology in Orchidaceae. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  12. Contrasting patterns of phylogenetic assemblage structure along the elevational gradient for major hummingbird clades

    DEFF Research Database (Denmark)

    Parra, Juan L.; Rahbek, Carsten; McGuire, Jimmy A.

    2011-01-01

    a variety of published and non-published sources. For the entire family and each of the major hummingbird clades (hermits, emeralds, mangoes, coquettes and brilliants) we quantified the phylogenetic structure of each assemblage using the net relatedness index (NRI). This index calculates the standardized...... relatives away from the elevation of origin at the family level and for assemblages of mangoes and brilliants. The opposite pattern was found for assemblages of coquettes and emeralds. For the hermits, variation in phylogenetic structure was not explained by elevation. Clades with high levels of feeding...

  13. Trace element contamination in feather and tissue samples from Anna’s hummingbirds

    Science.gov (United States)

    Mikoni, Nicole A.; Poppenga, Robert H.; Ackerman, Joshua T.; Foley, Janet E.; Hazlehurst, Jenny; Purdin, Güthrum; Aston, Linda; Hargrave, Sabine; Jelks, Karen; Tell, Lisa A.

    2017-01-01

    Trace element contamination (17 elements; Be, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Hg, Tl, and Pb) of live (feather samples only) and deceased (feather and tissue samples) Anna's hummingbirds (Calypte anna) was evaluated. Samples were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS; 17 elements) and atomic absorption spectrophotometry (Hg only). Mean plus one standard deviation (SD) was considered the benchmark, and concentrations above the mean + 1 SD were considered elevated above normal. Contour feathers were sampled from live birds of varying age, sex, and California locations. In order to reduce thermal impacts, minimal feathers were taken from live birds, therefore a novel method was developed for preparation of low mass feather samples for ICP-MS analysis. The study found that the novel feather preparation method enabled small mass feather samples to be analyzed for trace elements using ICP-MS. For feather samples from live birds, all trace elements, with the exception of beryllium, had concentrations above the mean + 1 SD. Important risk factors for elevated trace element concentrations in feathers of live birds were age for iron, zinc, and arsenic, and location for iron, manganese, zinc, and selenium. For samples from deceased birds, ICP-MS results from body and tail feathers were correlated for Fe, Zn, and Pb, and feather concentrations were correlated with renal (Fe, Zn, Pb) or hepatic (Hg) tissue concentrations. Results for AA spectrophotometry analyzed samples from deceased birds further supported the ICP-MS findings where a strong correlation between mercury concentrations in feather and tissue (pectoral muscle) samples was found. These study results support that sampling feathers from live free-ranging hummingbirds might be a useful, non-lethal sampling method for evaluating trace element exposure and provides a sampling alternative since their small body size limits traditional sampling of blood and tissues. The

  14. Computational analysis of unmanned aerial vehicle (UAV)

    Science.gov (United States)

    Abudarag, Sakhr; Yagoub, Rashid; Elfatih, Hassan; Filipovic, Zoran

    2017-01-01

    A computational analysis has been performed to verify the aerodynamics properties of Unmanned Aerial Vehicle (UAV). The UAV-SUST has been designed and fabricated at the Department of Aeronautical Engineering at Sudan University of Science and Technology in order to meet the specifications required for surveillance and reconnaissance mission. It is classified as a medium range and medium endurance UAV. A commercial CFD solver is used to simulate steady and unsteady aerodynamics characteristics of the entire UAV. In addition to Lift Coefficient (CL), Drag Coefficient (CD), Pitching Moment Coefficient (CM) and Yawing Moment Coefficient (CN), the pressure and velocity contours are illustrated. The aerodynamics parameters are represented a very good agreement with the design consideration at angle of attack ranging from zero to 26 degrees. Moreover, the visualization of the velocity field and static pressure contours is indicated a satisfactory agreement with the proposed design. The turbulence is predicted by enhancing K-ω SST turbulence model within the computational fluid dynamics code.

  15. UAV for landslide mapping and deformation analysis

    Science.gov (United States)

    Shi, Beiqi; Liu, Chun

    2015-12-01

    Unmanned aerial vehicle (UAV) can be a flexible, cost-effective, and accurate method to monitor landslides with high resolution aerial images. Images acquired on 05 May 2013 and 13 December 2014 of the Xishan landslide, China, have been used to produce a high-resolution ortho-mosaic of the entire landslide and digital elevation model (DEM). The UAV capability for imaging detection and displacements on the landslide surface has been evaluated, and the subsequent image processing approaches for suitably georectifying the data have been assessed. Objects derived from the segmentation of a multispectral image were used as classifying units for landslide object-oriented analysis. Spectral information together with various morphometric characteristics was applied for recognizing landslides from false positives. Digital image correlation technique was evaluated to quantify and map terrain displacements. The magnitude and direction of the displacement vectors derived from correlating two temporal UAV images corresponded to a visual interpretation of landslide change. Therefore, the UAV can demonstrate its capability for producing valuable landslide mapping data and deformation information.

  16. Adaptive pattern for autonomous UAV guidance

    Science.gov (United States)

    Sung, Chen-Ko; Segor, Florian

    2013-09-01

    The research done at the Fraunhofer IOSB in Karlsruhe within the AMFIS project is focusing on a mobile system to support rescue forces in accidents or disasters. The system consists of a ground control station which has the capability to communicate with a large number of heterogeneous sensors and sensor carriers and provides several open interfaces to allow easy integration of additional sensors into the system. Within this research we focus mainly on UAV such as VTOL (Vertical takeoff and Landing) systems because of their ease of use and their high maneuverability. To increase the positioning capability of the UAV, different onboard processing chains of image exploitation for real time detection of patterns on the ground and the interfacing technology for controlling the UAV from the payload during flight were examined. The earlier proposed static ground pattern was extended by an adaptive component which admits an additional visual communication channel to the aircraft. For this purpose different components were conceived to transfer additive information using changeable patterns on the ground. The adaptive ground pattern and their application suitability had to be tested under external influence. Beside the adaptive ground pattern, the onboard process chains and the adaptations to the demands of changing patterns are introduced in this paper. The tracking of the guiding points, the UAV navigation and the conversion of the guiding point positions from the images to real world co-ordinates in video sequences, as well as use limits and the possibilities of an adaptable pattern are examined.

  17. UAV visual signature suppression via adaptive materials

    NARCIS (Netherlands)

    Barrett, R.; Melkert, J.

    2005-01-01

    Visual signature suppression (VSS) methods for several classes of aircraft from WWII on are examined and historically summarized. This study shows that for some classes of uninhabited aerial vehicles (UAVs), primary mission threats do not stem from infrared or radar signatures, but from the amount t

  18. UAV imagery analysis: challenges and opportunities

    Science.gov (United States)

    Grant, Barbara G.

    2017-05-01

    As UAV imaging continues to expand, so too do the opportunities for improvements in data analysis. These opportunities, in turn, present their own challenges including the need for real time radiometric and spectral calibration; the continued development of quality metrics facilitating exploitation of strategic and tactical imagery; and the need to correct for sensor and platform-induced artifacts in image data.

  19. Toward Real Time Uavs' Image Mosaicking

    Science.gov (United States)

    Mehrdad, S.; Satari, M.; Safdary, M.; Moallem, P.

    2016-06-01

    Anyone knows that sudden catastrophes can instantly do great damage. Fast and accurate acquisition of catastrophe information is an essential task for minimize life and property damage. Compared with other ways of catastrophe data acquisition, UAV based platforms can optimize time, cost and accuracy of the data acquisition, as a result UAVs' data has become the first choice in such condition. In this paper, a novel and fast strategy is proposed for registering and mosaicking of UAVs' image data. Firstly, imprecise image positions are used to find adjoining frames. Then matching process is done by a novel matching method. With keeping Sift in mind, this fast matching method is introduced, which uses images exposure time geometry, SIFT point detector and rBRIEF descriptor vector in order to match points efficiency, and by efficiency we mean not only time efficiency but also elimination of mismatch points. This method uses each image sequence imprecise attitude in order to use Epipolar geometry to both restricting search space of matching and eliminating mismatch points. In consideration of reaching to images imprecise attitude and positions we calibrated the UAV's sensors. After matching process, RANSAC is used to eliminate mismatched tie points. In order to obtain final mosaic, image histograms are equalized and a weighted average method is used to image composition in overlapping areas. The total RMSE over all matching points is 1.72 m.

  20. Critical infrastructure monitoring using UAV imagery

    Science.gov (United States)

    Maltezos, Evangelos; Skitsas, Michael; Charalambous, Elisavet; Koutras, Nikolaos; Bliziotis, Dimitris; Themistocleous, Kyriacos

    2016-08-01

    The constant technological evolution in Computer Vision enabled the development of new techniques which in conjunction with the use of Unmanned Aerial Vehicles (UAVs) may extract high quality photogrammetric products for several applications. Dense Image Matching (DIM) is a Computer Vision technique that can generate a dense 3D point cloud of an area or object. The use of UAV systems and DIM techniques is not only a flexible and attractive solution to produce accurate and high qualitative photogrammetric results but also is a major contribution to cost effectiveness. In this context, this study aims to highlight the benefits of the use of the UAVs in critical infrastructure monitoring applying DIM. A Multi-View Stereo (MVS) approach using multiple images (RGB digital aerial and oblique images), to fully cover the area of interest, is implemented. The application area is an Olympic venue in Attica, Greece, at an area of 400 acres. The results of our study indicate that the UAV+DIM approach respond very well to the increasingly greater demands for accurate and cost effective applications when provided with, a 3D point cloud and orthomosaic.

  1. TU students sweep UAV design competition

    NARCIS (Netherlands)

    Klein, R.; Brust, S.; Brown, M.; Vos, R.

    2013-01-01

    To design a high-altitude long-endurance UAV to fly a twenty-hour reconnaissance mission at an altitude of 80,000ft, was the assignment for this year’s undergraduate design competition. The competition was organized by the American Institute of Aeronautics and Astronautics (AIAA). Three students fro

  2. UAV Robust Strategy Control Based on MAS

    Directory of Open Access Journals (Sweden)

    Jian Han

    2014-01-01

    Full Text Available A novel multiagent system (MAS has been proposed to integrate individual UAV (unmanned aerial vehicle to form a UAV team which can accomplish complex missions with better efficiency and effect. The MAS based UAV team control is more able to conquer dynamic situations and enhance the performance of any single UAV. In this paper, the MAS proposed and established combines the reacting and thinking abilities to be an initiative and autonomous hybrid system which can solve missions involving coordinated flight and cooperative operation. The MAS uses BDI model to support its logical perception and to classify the different missions; then the missions will be allocated by utilizing auction mechanism after analyzing dynamic parameters. Prim potential algorithm, particle swarm algorithm, and reallocation mechanism are proposed to realize the rational decomposing and optimal allocation in order to reach the maximum profit. After simulation, the MAS has been proved to be able to promote the success ratio and raise the robustness, while realizing feasibility of coordinated flight and optimality of cooperative mission.

  3. Low complexity video encoding for UAV inspection

    DEFF Research Database (Denmark)

    Søgaard, Jacob; Zhang, Ruo; Forchhammer, Søren

    2016-01-01

    In this work we present several methods for fast integer motion estimation of videos recorded aboard an Unmanned Aerial Vehicle (UAV). Different from related work, the field depth is not considered to be consistent. The novel methods designed for low complexity MV prediction in H.264/AVC...

  4. An optimization model of UAV route planning for road segment surveillance

    Institute of Scientific and Technical Information of China (English)

    刘晓锋; 关志伟; 宋裕庆; 陈大山

    2014-01-01

    Unmanned aerial vehicle (UAV) was introduced to take road segment traffic surveillance. Considering the limited UAV maximum flight distance, UAV route planning problem was studied. First, a multi-objective optimization model of planning UAV route for road segment surveillance was proposed, which aimed to minimize UAV cruise distance and minimize the number of UAVs used. Then, an evolutionary algorithm based on Pareto optimality technique was proposed to solve multi-objective UAV route planning problem. At last, a UAV flight experiment was conducted to test UAV route planning effect, and a case with three scenarios was studied to analyze the impact of different road segment lengths on UAV route planning. The case results show that the optimized cruise distance and the number of UAVs used decrease by an average of 38.43% and 33.33%, respectively. Additionally, shortening or extending the length of road segments has different impacts on UAV route planning.

  5. Adaptive information interactive mechanism for multi-UAV visual navigation

    Science.gov (United States)

    Liu, Hui; Dai, Qionghai

    2012-06-01

    Multi-unmanned aerial vehicle (UAV) cooperative communication for visual navigation has recently generated significant concern. It has large amounts of visual information to be transmitted and processed among UAVs with realtime requirements. And the UAV clusters have self-organized, time-varying and high dynamic characteristics. Considering the above conditions, we propose an adaptive information interactive mechanism (AIIM) for multi-UAV visual navigation. In the mechanism, the function modules for UAV inter-communication interface are designed, the mobility-based link lifetime is established and the information interactive protocol is presented. Thus we combine the mobility of UAVs with the corresponding communication requirements to make effective information interaction for UAVs. Task-oriented distributed control is adopted to improve the collaboration flexibility in the multi-UAV visual navigation system. In order to timely obtain the necessary visual information, each UAV can cooperate with other relevant UAVs which meet some certain terms such as situation, task or environmental conditions. Simulation results are presented to show the validity of the proposed mechanism in terms of end-to-end delay and links stability.

  6. Spurious RF signals emitted by mini-UAVs

    Science.gov (United States)

    Schleijpen, Ric (H. M. A.); Voogt, Vincent; Zwamborn, Peter; van den Oever, Jaap

    2016-10-01

    This paper presents experimental work on the detection of spurious RF emissions of mini Unmanned Aerial Vehicles (mini-UAV). Many recent events have shown that mini-UAVs can be considered as a potential threat for civil security. For this reason the detection of mini-UAVs has become of interest to the sensor community. The detection, classification and identification chain can take advantage of different sensor technologies. Apart from the signatures used by radar and electro-optical sensor systems, the UAV also emits RF signals. These RF signatures can be split in intentional signals for communication with the operator and un-intentional RF signals emitted by the UAV. These unintentional or spurious RF emissions are very weak but could be used to discriminate potential UAV detections from false alarms. The goal of this research was to assess the potential of exploiting spurious emissions in the classification and identification chain of mini-UAVs. It was already known that spurious signals are very weak, but the focus was on the question whether the emission pattern could be correlated to the behaviour of the UAV. In this paper experimental examples of spurious RF emission for different types of mini-UAVs and their correlation with the electronic circuits in the UAVs will be shown

  7. 基于UIO的四旋翼飞行器故障检测与隔离%Fault detection and isolation for a quadrotor via unknown input observer

    Institute of Scientific and Technical Information of China (English)

    白慧; 王红雨; 邵世煌

    2013-01-01

      故障检测与隔离(FDI)对于增强四旋翼飞行器的安全性和鲁棒性具有重要作用。提出了一种四旋翼飞行器执行器故障的FDI方法。首先建立了四旋翼飞行器的简化线性模型。然后研究了基于未知输入观测器(UIO)的故障检测与隔离方案。针对四个执行器,分别设计了四个UIO以产生通用结构化残差组,对执行器故障进行检测与隔离。仿真实验证实了该FDI方案的可行性。%The fault detection and isolation(FDI) places an important role in enhancing the safety and robustness of a quadrotor. In this paper, a simplified linear dynamic model of the quadrotor rotorcraft was introduced. An FDI scheme based on unknown input observer(UIO) for actuator faults of the quadrotor was proposed. A generalized structure residual set was designed via four UIOs to detect and isolate faults of the four actuators. Simulation results show the effectiveness of the proposed FDI scheme.

  8. Toward understanding the mechanics of hovering in insects, hummingbirds and bats

    Science.gov (United States)

    Vejdani, Hamid; Boerma, David; Swartz, Sharon; Breuer, Kenneth

    2016-11-01

    We present results on the dynamical characteristics of two different mechanisms of hovering, corresponding to the behavior of hummingbirds and bats. Using a Lagrangian formulation, we have developed a dynamical model of a body (trunk) and two rectangular wings. The trunk has 3 degrees of freedom (x, z and pitch angle) and each wing has 3 modes of actuation: flapping, pronation/supination, and wingspan extension/flexion (only present for bats). Wings can be effectively massless (hummingbird and insect wings) or relatively massive (important in the case of bats). The aerodynamic drag and lift forces are calculated using a quasi-steady blade-element model. The regions of state space in which hovering is possible are computed by over an exhaustive range of parameters. The effect of wing mass is to shrink the phase space available for viable hovering and, in general, to require higher wingbeat frequency. Moreover, by exploring hovering energy requirements, we find that the pronation angle of the wings also plays a critical role. For bats, who have relatively heavy wings, we show wing extension and flexion is critical in order to maintain a plausible hovering posture with reasonable power requirements. Comparisons with biological data show good agreement with our model predictions.

  9. Bimodal pollination system of the bromeliad Aechmea nudicaulis involving hummingbirds and bees.

    Science.gov (United States)

    Schmid, S; Schmid, V S; Zillikens, A; Harter-Marques, B; Steiner, J

    2011-01-01

    In order to compare the effectiveness of birds and insects as pollinators, we studied the floral biology of the bromeliad Aechmea nudicaulis (L.) Grisebach in the biome of the Atlantic rain forest, southern Brazil. On Santa Catarina Island, flowering extends from mid-September to the end of December, with diurnal anthesis. The reproductive system is obligatory xenogamy, thus pollinator-dependent. Flowers secrete 31.84 μl of nectar per day, with a mean sugar concentration of 23.2%. Highest nectar volume and sugar concentration occur at the beginning of anthesis. Most floral traits are characteristic for ornithophily, and nectar production appears to be adapted to the energy demand of hummingbirds. Continued secretion of the sucrose-dominated nectar attracts and binds visitors to inflorescences, strengthening trapline foraging behaviour. Experiments assessing seed set after single flower visits were performed with the most frequent visitors, revealing the hummingbird Thalurania glaucopis as the most effective pollen vector. In addition, bees are also functional pollinators, as substantiated by their high visitation frequency. We conclude that this pollination system is bimodal. Thus, there is redundancy in the pollination service provided by birds and bees, granting a high probability of successful reproduction in Ae. nudicaulis.

  10. Fragmentation of CagA Reduces Hummingbird Phenotype Induction by Helicobactor pylori.

    Directory of Open Access Journals (Sweden)

    Chih-Chi Chang

    Full Text Available Infection with Helicobacter pylori (H. pylori has been linked to various gastro-intestinal diseases; nevertheless it remains to be clarified why only a minority of infected individuals develop illness. Studies from the West have indicated that the cagA gene and the associated EPIYA genotype of H. pylori is closely linked to the development of severe gastritis and gastric carcinoma; however, as yet no consistent correlation has been found among the bacteria from East Asia. In addition to genotype variation, the CagA protein undergoes fragmentation; however, the functional significance of fragmentation with respect to H. pylori infection remains unknown. In this study, we isolated 594 H. pylori colonies from 99 patients and examined the fragmentation patterns of CagA protein using immunoblotting. By analyzing the ability of the isolates to induce the host cell morphological transition to the highly invasive hummingbird phenotype, we demonstrated that H. pylori colonies with substantial CagA fragmentation are less potent in terms of causing this morphological transition. Our results uncovered a functional role for CagA fragmentation with respect to H. pylori-induced hummingbird phenotype formation and these findings suggest the possibility that the post-translational processing of CagA may be involved in H. pylori infection pathogenesis.

  11. Wing, tail, and vocal contributions to the complex acoustic signals of courting Calliope hummingbirds

    Directory of Open Access Journals (Sweden)

    Christopher James CLARK

    2011-04-01

    Full Text Available Multi-component signals contain multiple signal parts expressed in the same physical modality. One way to identify individual components is if they are produced by different physical mechanisms. Here, I studied the mechanisms generating acoustic signals in the courtship displays of the Calliope hummingbird Stellula calliope. Display dives consisted of three synchronized sound elements, a high-frequency tone (hft, a low frequency tone (lft, and atonal sound pulses (asp, which were then followed by a frequency-modulated fall. Manipulating any of the rectrices (tail-feathers of wild males impaired production of the lft and asp but not the hft or fall, which are apparently vocal. I tested the sound production capabilities of the rectrices in a wind tunnel. Single rectrices could generate the lft but not the asp, whereas multiple rectrices tested together produced sounds similar to the asp when they fluttered and collided with their neighbors percussively, representing a previously unknown mechanism of sound production. During the shuttle display, a trill is generated by the wings during pulses in which the wingbeat frequency is elevated to 95 Hz, 40% higher than the typical hovering wingbeat frequency. The Calliope hummingbird courtship displays include sounds produced by three independent mechanisms, and thus include a minimum of three acoustic signal components. These acoustic mechanisms have different constraints and thus potentially contain different messages. Producing multiple acoustic signals via multiple mechanisms may be a way to escape the constraints present in any single mechanism [Current Zoology 57 (2: 187–196, 2011].

  12. The Hummingbird GC-IMS: In Situ Analysis of a Cometary Nucleus

    Science.gov (United States)

    Kojiro, Daniel R.; Carle, Glenn C.; Cohen, Martin J.; Wernlund, Roger F.; Stimac, Robert M.; Takeuchi, Norishige; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Comets are of enormous scientific interest for many reasons. They are primitive bodies that date back to the earliest stages of solar system formation and, because of their small size and because they have been stored in the outer reaches of the solar system, their pristine nature has been preserved better than for any other class of body. They are extremely rich in highly volatile elements, many in the form of ices, and are richer in organic matter than any other known solar system body. It is strongly suspected that in addition to their content of primordial solar nebular material, they also incorporate unprocessed matter from the interstellar medium. Impacts by comets occur onto all the planets and satellites, often with major consequences (e.g., the dinosaur extinction event at the KIT boundary), or sometimes just providing a spectacular cosmic event (e.g., the collision of comet Shoemaker-Levy 9 with Jupiter). A mission to analyze a cometary nucleus must be capable of detecting and identifying over 30 molecular species among several different chemical groups. The Hummingbird Mission will rendezvous with, orbit, characterize, and make multiple descents to the nucleus of a comet. Hummingbird will employ a Gas Chromatograph - Ion Mobility Spectrometer (GC-IMS) as part-of a suite of sophisticated instruments for a comprehensive in situ elemental, molecular, and isotopic analysis of the comet.

  13. Different foraging preferences of hummingbirds on artificial and natural flowers reveal mechanisms structuring plant-pollinator interactions.

    Science.gov (United States)

    Maglianesi, María A; Böhning-Gaese, Katrin; Schleuning, Matthias

    2015-05-01

    In plant-pollinator networks, the floral morphology of food plants is an important determinant of the interaction niche of pollinators. Studies on foraging preferences of pollinators combining experimental and observational approaches may help to understand the mechanisms behind patterns of interactions and niche partitioning within pollinator communities. In this study, we tested whether morphological floral traits were associated with foraging preferences of hummingbirds for artificial and natural flower types in Costa Rica. We performed field experiments with artificial feeders, differing in length and curvature of flower types, to quantify the hummingbirds' interaction niche under unlimited nectar resources. To quantify the interaction niche under real-world conditions of limited nectar resources, we measured foraging preferences of hummingbirds for a total of 34 plant species. Artificial feeders were visited by Eupherusa nigriventris and Phaethornis guy in the pre-montane forest, and Lampornis calolaemus in the lower montane forest. Under experimental conditions, all three hummingbird species overlapped their interaction niches and showed a preference for the short artificial flower type over the long-straight and the long-curved flower types. Under natural conditions, the two co-occurring hummingbird species preferred to feed on plant species with floral traits corresponding to their bill morphology. The short-billed hummingbird E. nigriventris preferred to feed on short and straight flowers, whereas the long- and curved-billed P. guy preferred long and curved natural flowers. The medium-size billed species L. calolaemus preferred to feed on flowers of medium length and did not show preferences for plant species with specific corolla curvature. Our results show that floral morphological traits constrain access by short-billed hummingbird species to nectar resources. Morphological constraints, therefore, represent one important mechanism structuring trophic

  14. Cooperative Search and Task Allocation Among Heterogeneous Teams of UAVs

    Institute of Scientific and Technical Information of China (English)

    SHEN Yan-hang; ZHOU Zhou

    2008-01-01

    A cooperative control method of multi-class UAV (unmanned air vehicle) team is investigated. During the mission, the UAVs perform search, classification, attack and battle damage assessment (BDA) tasks at various locations, which involves a combination of the team intelligence type of decision making combined with control, estimate and real-time trajectory optimization. The search-theoretic approach based on rate of return (ROR) maps is developed to get the cooperative search strategy. Templates are developed and views are combined to maximize the probability of correct target identification over various aspect angles. Monte Carle simulation runs for the scenario to evaluate the performance of the approach with various decision parameters, UAVs distributions and UAV team characteristics. Simulation results show that the cooperative behavior can significantly improve the operational effectiveness of UAV team, and the cooperative control allows for near optimal solution of the correlative behavior of a group of UAVs in battlefield.

  15. A unified cooperative control architecture for UAV missions

    Science.gov (United States)

    Tian, Xin; Bar-Shalom, Yaakov; Chen, Genshe; Blasch, Erik; Pham, Khanh

    2012-06-01

    In this paper, we propose a unified cooperative control architecture (UCCA) that supports effective cooperation of Unmanned Aerial Vehicles (UAVs) and learning capabilities for UAV missions. Main features of the proposed UCCA include: i) it has a modular structure; each function module focuses on a particular type of task and provide services to other function modules through well defined interfaces; ii) it allows the efficient sharing of UAV control and onboard resources by the function modules and is able to effectively handle simultaneously multiple objectives in the UAV operation; iii) it facilitates the cooperation among different function modules; iv) it supports effective cooperation among multiple UAVs on a mission's tasks, v) an objective driven learning approach is also supported, which allows UAVs to systematically explore uncertain mission environments to increase the level of situation awareness for the achievement of their mission/task objectives.

  16. Hummingbird responses to gender-biased nectar production: are nectar biases maintained by natural or sexual selection?

    Science.gov (United States)

    Carlson, Jane E

    2008-01-01

    Pollinators mediate the evolution of secondary floral traits through both natural and sexual selection. Gender-biased nectar, for example, could be maintained by one or both, depending on the interactions between plants and pollinators. Here, I investigate pollinator responses to gender-biased nectar using the dichogamous herb Chrysothemis friedrichsthaliana (Gesneriaceae) which produces more nectar during the male floral phase. Previous research showed that the hummingbird pollinator Phaethornis striigularis visited male-phase flowers more often than female-phase flowers, and multiple visits benefited male more than female fecundity. If sexual selection maintains male-biased rewards, hummingbirds should prefer more-rewarding flowers independent of floral gender. If, however, differential rewards are partially maintained through natural selection, hummingbirds should respond to asymmetry with visits that reduce geitonogamy, i.e. selfing and pollen discounting. In plants with male biases, these visit types include single-flower visits and movements from low to high rewards. To test these predictions, I manipulated nectar asymmetry between pairs of real or artificial flowers on plants and recorded foraging behaviour. I also assessed maternal costs of selfing using hand pollinations. For plants with real flowers, hummingbirds preferred more-rewarding flowers and male-phase morphology, the latter possibly owing to previous experience. At artificial arrays, hummingbirds responded to extreme reward asymmetry with increased single-flower visits; however, they moved from high to low rewards more often than low to high. Finally, selfed flowers did not produce inferior seeds. In summary, sexual selection, more so than geitonogamy avoidance, maintains nectar biases in C. friedrichsthaliana, in one of the clearest examples of sexual selection in plants, to date. PMID:18460431

  17. UAV anti-icing system based on conductive coating

    OpenAIRE

    Helland, Andreas Strand

    2014-01-01

    Icing on leading edge surfaces such as wings and propeller blades presents a major risk for UAVs operating in a cold and humid environment. Reducing or loss of manoeuvrability, loss of lift, increase in drag, reducing performance through increased weight and in worst case crashing, are phenomena that can occur in case of ice formation on a UAV surface. The use of UAVs has increased significantly the last years through surveillance and reconnaissance operations and they are able to perform ope...

  18. Cell size and basal metabolic rate in hummingbirds Tamaño celular y tasa metabólica basal en picaflores

    National Research Council Canada - National Science Library

    Juan C. Opazo; Mauricio Soto-Gamboa; Maria José Fernández

    2005-01-01

    .... Knowing that cell size is proportional to C-value, in this study we tested for a relationship between mean corpuscular volume of red blood cells and BMR in four species of hummingbirds ranging from 4 to 20 g...

  19. Autonomous search, tracking and classification by multiple cooperative UAVs

    Science.gov (United States)

    Sinha, A.; Kirubarajan, T.; Bar-Shalom, Y.

    2006-05-01

    In this paper we propose a cooperative control algorithm for a group of UAVs carrying out surveillance --- search, tracking and classification --- over a large region which includes a number of targets. The goal is to track and classify detected targets as well as search for new targets. The UAVs are assumed to be equipped with Ground Moving Target Indicator (GMTI) radars, which measure the locations of moving ground targets as well as their radial velocities (Doppler). In addition, a classification sensor is mounted on each UAV that can obtain target class information. The surveillance region is divided into a number of sectors and it is assumed that the GMTI sensor on each UAV scans a fixed number of such sectors in each period of its operation. The sensor responsible for class information can scan only a small circular region around the predicted position of a target. In this paper, a decentralized cooperative control algorithm is proposed, according to which each UAV transmits the current scan information (either kinematic or class information) and detection information (including "negative information") to the other UAVs. Each UAV makes its scan decision and path decision separately, based on information-based objective functions, which incorporate target state information as well as target detection probability and survival probability due to possible hostile fire by targets and collision with other UAVs. The proposed algorithm requires limited communication and modest computation and it can handle failure in communication and loss of UAVs.

  20. Vision based systems for UAV applications

    CERN Document Server

    Kuś, Zygmunt

    2013-01-01

    This monograph is motivated by a significant number of vision based algorithms for Unmanned Aerial Vehicles (UAV) that were developed during research and development projects. Vision information is utilized in various applications like visual surveillance, aim systems, recognition systems, collision-avoidance systems and navigation. This book presents practical applications, examples and recent challenges in these mentioned application fields. The aim of the book is to create a valuable source of information for researchers and constructors of solutions utilizing vision from UAV. Scientists, researchers and graduate students involved in computer vision, image processing, data fusion, control algorithms, mechanics, data mining, navigation and IC can find many valuable, useful and practical suggestions and solutions. The latest challenges for vision based systems are also presented.

  1. Neuro-optimal control of helicopter UAVs

    Science.gov (United States)

    Nodland, David; Ghosh, Arpita; Zargarzadeh, H.; Jagannathan, S.

    2011-05-01

    Helicopter UAVs can be extensively used for military missions as well as in civil operations, ranging from multirole combat support and search and rescue, to border surveillance and forest fire monitoring. Helicopter UAVs are underactuated nonlinear mechanical systems with correspondingly challenging controller designs. This paper presents an optimal controller design for the regulation and vertical tracking of an underactuated helicopter using an adaptive critic neural network framework. The online approximator-based controller learns the infinite-horizon continuous-time Hamilton-Jacobi-Bellman (HJB) equation and then calculates the corresponding optimal control input that minimizes the HJB equation forward-in-time. In the proposed technique, optimal regulation and vertical tracking is accomplished by a single neural network (NN) with a second NN necessary for the virtual controller. Both of the NNs are tuned online using novel weight update laws. Simulation results are included to demonstrate the effectiveness of the proposed control design in hovering applications.

  2. Nearshore Measurements From a Small UAV.

    Science.gov (United States)

    Holman, R. A.; Brodie, K. L.; Spore, N.

    2016-02-01

    Traditional measurements of nearshore hydrodynamics and evolving bathymetry are expensive and dangerous and must be frequently repeated to track the rapid changes of typical ocean beaches. However, extensive research into remote sensing methods using cameras or radars mounted on fixed towers has resulted in increasingly mature algorithms for estimating bathymetry, currents and wave characteristics. This naturally raises questions about how easily and effectively these algorithms can be applied to optical data from low-cost, easily-available UAV platforms. This paper will address the characteristics and quality of data taken from a small, low-cost UAV, the DJI Phantom. In particular, we will study the stability of imagery from a vehicle `parked' at 300 feet altitude, methods to stabilize remaining wander, and the quality of nearshore bathymetry estimates from the resulting image time series, computed using the cBathy algorithm. Estimates will be compared to ground truth surveys collected at the Field Research Facility at Duck, NC.

  3. Technologies Advance UAVs for Science, Military

    Science.gov (United States)

    2010-01-01

    A Space Act Agreement with Goddard Space Flight Center and West Virginia University enabled Aurora Flight Sciences Corporation, of Manassas, Virginia, to develop cost-effective composite manufacturing capabilities and open a facility in West Virginia. The company now employs 160 workers at the plant, tasked with crafting airframe components for the Global Hawk unmanned aerial vehicle (UAV) program. While one third of the company's workforce focuses on Global Hawk production, the rest of the company develops advanced UAV technologies that are redefining traditional approaches to unmanned aviation. Since the company's founding, Aurora s cutting-edge work has been supported with funding from NASA's Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) programs.

  4. A proposed UAV for indoor patient care.

    Science.gov (United States)

    Todd, Catherine; Watfa, Mohamed; El Mouden, Yassine; Sahir, Sana; Ali, Afrah; Niavarani, Ali; Lutfi, Aoun; Copiaco, Abigail; Agarwal, Vaibhavi; Afsari, Kiyan; Johnathon, Chris; Okafor, Onyeka; Ayad, Marina

    2015-09-10

    Indoor flight, obstacle avoidance and client-server communication of an Unmanned Aerial Vehicle (UAV) raises several unique research challenges. This paper examines current methods and associated technologies adapted within the literature toward autonomous UAV flight, for consideration in a proposed system for indoor healthcare administration with a quadcopter. We introduce Healthbuddy, a unique research initiative towards overcoming challenges associated with indoor navigation, collision detection and avoidance, stability, wireless drone-server communications and automated decision support for patient care in a GPS-denied environment. To address the identified research deficits, a drone-based solution is presented. The solution is preliminary as we develop and refine the suggested algorithms and hardware system to achieve the research objectives.

  5. Structurally Integrated Antenna Concepts for HALE UAVs

    Science.gov (United States)

    Cravey, Robin L.; Vedeler, Erik; Goins, Larry; Young, W. Robert; Lawrence, Roland W.

    2006-01-01

    This technical memorandum describes work done in support of the Multifunctional Structures and Materials Team under the Vehicle Systems Program's ITAS (Integrated Tailored Aero Structures) Project during FY 2005. The Electromagnetics and Sensors Branch (ESB) developed three ultra lightweight antenna concepts compatible with HALE UAVs (High Altitude Long Endurance Unmanned Aerial Vehicles). ESB also developed antenna elements that minimize the interaction between elements and the vehicle to minimize the impact of wing flexure on the EM (electromagnetic) performance of the integrated array. In addition, computer models were developed to perform phase correction for antenna arrays whose elements are moving relative to each other due to wing deformations expected in HALE vehicle concepts. Development of lightweight, conformal or structurally integrated antenna elements and compensating for the impact of a lightweight, flexible structure on a large antenna array are important steps in the realization of HALE UAVs for microwave applications such as passive remote sensing and communications.

  6. CFD Analysis of UAV Flying Wing

    Directory of Open Access Journals (Sweden)

    Vasile PRISACARIU

    2016-09-01

    Full Text Available Numerical methods for solving equations describing the evolution of 3D fluid experienced a significant development closely related to the progress of information systems. Today, especially in the field of fluid mechanics, numerical simulations allow the study of gas-thermodynamic confirmed by experimental techniques in wind tunnel conditions and actual flight tests for modeling complex aircraft. The article shows a case of numerical analysis of the lifting surface on the UAV type flying wing.

  7. Baseline and Multimodal UAV GCS Interface Design

    Science.gov (United States)

    2013-07-01

    necessary. Our situational awareness questionnaire which was implemented during the experimental session had a number of questions that were confusing...during the training phase, one where the participant is required to abort the landing and one where the UAV can land safely. The additional practice...scenario was added to remove the bias of experiencing only an abort scenario during the training phase. A new visual indicator of engine

  8. CLASSICAL PHOTOGRAMMETRY AND UAV – SELECTED ASCPECTS

    OpenAIRE

    S. Mikrut

    2016-01-01

    The UAV technology seems to be highly future-oriented due to its low costs as compared to traditional aerial images taken from classical photogrammetry aircrafts. The AGH University of Science and Technology in Cracow - Department of Geoinformation, Photogrammetry and Environmental Remote Sensing focuses mainly on geometry and radiometry of recorded images. Various scientific research centres all over the world have been conducting the relevant research for years. The paper presents selected ...

  9. Effect of artificial feeders on pollen loads of the hummingbirds of Cerro de La Muerte, Costa Rica

    Directory of Open Access Journals (Sweden)

    Gerardo Avalos

    2012-03-01

    Full Text Available Although sugar-water feeders are commonly used by enthusiasts to attract hummingbirds, little is known about how they affect hummingbird behavior and flower use. We studied the highland hummingbird assemblage of Cerro de La Muerte, Costa Rica, both at a site with permanent feeders (La Georgina Restaurant and further from it. We examined how feeder use and monopolization affected seasonal changes in pollen loads during four sampling periods, including dry and wet seasons, from 2003-2005. We expected that species monopolizing the feeders would carry little or no pollen whatsoever, and would have pollen loads characterized by low floral diversity, in contrast with species less dependent on feeders. We obtained pollen samples from 183 individuals of four hummingbird species captured around the feeders using mist nets, which were compared with a pollen reference collection of plants with a pollination syndrome by hummingbirds. The same methods were implemented at a site 3km away from the feeders. Feeder usage was quantified by counting the number of times hummingbirds drank from the feeders in periods of 4min separated by 1min. The effects of hummingbird species and season on pollen load categories were assessed using a nominal logistic regression. The alpha species at the site, the Fiery-throated Hummingbird (Panterpe insignis, dominated the feeders during the dry season. Meanwhile, in the wet season, feeder usage was more evenly distributed across species, with the exception of the Volcano Hummingbird, Selasphorus flammula, which occupies the last place in the dominance hierarchy. Pollen loads of hummingbirds captured near feeders were low in abundance (more than 50% of captured individuals had zero or low pollen loads, and low in species richness (96% of the hummingbirds with pollen from only one plant genus, Centropogon. Overall pollen loads increased during the dry season coinciding with peaks in flower availability, although the majority of

  10. UAV magnetometry in mineral exploration and infrastructure detection

    Science.gov (United States)

    Braun, A.; Parvar, K.; Burns, M.

    2015-12-01

    Magnetic surveys are critical tools in mineral exploration and UAVs have the potential to carry magnetometers. UAV surveys can offer higher spatial resolution than traditional airborne surveys, and higher coverage than terrestrial surveys. However, the main advantage is their ability to sense the magnetic field in 3-D, while most airborne or terrestrial surveys are restricted to 2-D acquisition. This study compares UAV magnetic data from two different UAVs (JIB drone, DJI Phantom 2) and three different magnetometers (GEM GSPM35, Honeywell HMR2300, GEM GST-19). The first UAV survey was conducted using a JIB UAV with a GSPM35 flying at 10-15 m above ground. The survey's goal was to detect intrusive Rhyolite bodies for primary mineral exploration. The survey resulted in a better understanding of the validity/resolution of UAV data and led to improved knowledge about the geological structures in the area. The results further drove the design of a following terrestrial survey. Comparing the UAV data with an available airborne survey (upward continued to 250 m) reveals that the UAV data has superior spatial resolution, but exhibits a higher noise level. The magnetic anomalies related to the Rhyolite intrusions is about 109 nT and translates into an estimated depth of approximately 110 meters. The second survey was conducted using an in-house developed UAV magnetometer system equipped with a DJI Phantom 2 and a Honeywell HMR2300 fluxgate magnetometer. By flying the sensor in different altitudes, the vertical and horizontal gradients can be derived leading to full 3-D magnetic data volumes which can provide improved constraints for source depth/geometry characterization. We demonstrate that a buried steam pipeline was detectable with the UAV magnetometer system and compare the resulting data with a terrestrial survey using a GEM GST-19 Proton Precession Magnetometer.

  11. Prognostics Applied to Electric Propulsion UAV

    Science.gov (United States)

    Goebel, Kai; Saha, Bhaskar

    2013-01-01

    Health management plays an important role in operations of UAV. If there is equipment malfunction on critical components, safe operation of the UAV might possibly be compromised. A technology with particular promise in this arena is equipment prognostics. This technology provides a state assessment of the health of components of interest and, if a degraded state has been found, it estimates how long it will take before the equipment will reach a failure threshold, conditional on assumptions about future operating conditions and future environmental conditions. This chapter explores the technical underpinnings of how to perform prognostics and shows an implementation on the propulsion of an electric UAV. A particle filter is shown as the method of choice in performing state assessment and predicting future degradation. The method is then applied to the batteries that provide power to the propeller motors. An accurate run-time battery life prediction algorithm is of critical importance to ensure the safe operation of the vehicle if one wants to maximize in-air time. Current reliability based techniques turn out to be insufficient to manage the use of such batteries where loads vary frequently in uncertain environments.

  12. GPS Remote Sensing Measurements Using Aerosonde UAV

    Science.gov (United States)

    Grant, Michael S.; Katzberg, Stephen J.; Lawrence, R. W.

    2005-01-01

    In February 2004, a NASA-Langley GPS Remote Sensor (GPSRS) unit was flown on an Aerosonde unmanned aerial vehicle (UAV) from the Wallops Flight Facility (WFF) in Virginia. Using direct and surface-reflected 1.575 GHz coarse acquisition (C/A) coded GPS signals, remote sensing measurements were obtained over land and portions of open water. The strength of the surface-reflected GPS signal is proportional to the amount of moisture in the surface, and is also influenced by surface roughness. Amplitude and other characteristics of the reflected signal allow an estimate of wind speed over open water. In this paper we provide a synopsis of the instrument accommodation requirements, installation procedures, and preliminary results from what is likely the first-ever flight of a GPS remote sensing instrument on a UAV. The correct operation of the GPSRS unit on this flight indicates that Aerosonde-like UAV's can serve as platforms for future GPS remote sensing science missions.

  13. Tls Models Generation Assisted by Uav Survey

    Science.gov (United States)

    Chiabrando, F.; Di Pietra, V.; Lingua, A.; Maschio, P.; Noardo, F.; Sammartano, G.; Spanò, A.

    2016-06-01

    (TLS, Terrestrial Laser Scanning), and large scale mapping derived by UAV (Unmanned Aerial Vehicle) survey. This paper refers an example of 3D survey and reality based modelling applied on landscape and architectural assets. The choice of methods for documentation, in terms of survey techniques, depends primarily on issues and features of the area. The achieved experience, allow to consider that the easy handling of TLS has enabled the use in limited spaces among buildings and collapsed roofs, but the topographic measure of GCPs (Ground Control Points), neither by total station nor by GPS/RTK technique, was easily feasible. Even more than proving the ability of the integration of TLS and UAV photogrammetry to achieve a multi-source and multi-scale whole model of a village, the experience has been a test to experiment the registration of terrestrial clouds with the support of control points derived by UAV survey and finally, a comparison among different strategies of clouds registration is reported. Analysing for each approach a number of parameters (number of clouds registration, number of needed points, processing time, overall accuracy) the further comparisons have been achieved. The test revealed that it is possible to decrease the large number of terrestrial control points when their determination by topographical measures is difficult, and it is possible to combine the techniques not only for the integration of the final 3Dmodel, but also to solve and make the initial stage of the drafting process more effective.

  14. TLS MODELS GENERATION ASSISTED BY UAV SURVEY

    Directory of Open Access Journals (Sweden)

    F. Chiabrando

    2016-06-01

    Full Text Available (TLS, Terrestrial Laser Scanning, and large scale mapping derived by UAV (Unmanned Aerial Vehicle survey. This paper refers an example of 3D survey and reality based modelling applied on landscape and architectural assets. The choice of methods for documentation, in terms of survey techniques, depends primarily on issues and features of the area. The achieved experience, allow to consider that the easy handling of TLS has enabled the use in limited spaces among buildings and collapsed roofs, but the topographic measure of GCPs (Ground Control Points, neither by total station nor by GPS/RTK technique, was easily feasible. Even more than proving the ability of the integration of TLS and UAV photogrammetry to achieve a multi-source and multi-scale whole model of a village, the experience has been a test to experiment the registration of terrestrial clouds with the support of control points derived by UAV survey and finally, a comparison among different strategies of clouds registration is reported. Analysing for each approach a number of parameters (number of clouds registration, number of needed points, processing time, overall accuracy the further comparisons have been achieved. The test revealed that it is possible to decrease the large number of terrestrial control points when their determination by topographical measures is difficult, and it is possible to combine the techniques not only for the integration of the final 3Dmodel, but also to solve and make the initial stage of the drafting process more effective.

  15. ENGAGING ELEMENTARY AND MIDDLE SCHOOL STUDENTS IN ROBOTICS THROUGH HUMMINGBIRD KIT WITH SNAP! VISUAL PROGRAMMING LANGUAGE

    Directory of Open Access Journals (Sweden)

    Anna Newley

    2016-07-01

    Full Text Available The purpose of this paper is to describe how Hummingbird robotics kit with Snap! programing language was used to introduce basics of robotics to elementary and middle school students. Each student in the robotics program built a robot. The robot building process was open ended. Any specific robotics challenge was not provided to the students. Students’ knowledge about robots and programming language were measured through pre, post, and delayed posttests. Results indicated that students improved their knowledge about robotics and programing language at the end of the robotics program. Delayed posttest results indicated that the students were able to sustain their improved knowledge two months after the posttest. Formal data about student motivation and interest in STEM learning were not collected; however, it was observed that students expressed interest to participate in more advanced robotics programs in the future.

  16. Study on Guidance Law of UAV Net Recovery System

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yi; ZHAO Shao-song; WANG Yong-sheng; ZHANG Yu-zhuo

    2007-01-01

    The design and realization of a net recovery system is introduced, which can recover UAV (unmanned aerial vehicle) reliably and safely. The mathematical model is built, and the horizontal and vertical guidance law is studied based on the aerodynamic parameters and actual flying trial data of a certain UAV. The simulation result shows that this system can realize the recovery safely, stably and accurately.

  17. Multi‐angular observations of vegetation indices from UAV cameras

    DEFF Research Database (Denmark)

    Sobejano-Paz, Veronica; Wang, Sheng; Jakobsen, Jakob

    Unmanned aerial vehicles (UAVs) are found as an alternative to the classical manned aerial photogrammetry, which can be used to obtain environmental data or as a complementary solution to other methods (Nex and Remondino, 2014). Although UAVs have coverage limitations, they have better resolution...

  18. Guidance and control for an autonomous soaring UAV

    Science.gov (United States)

    Allen, Michael J. (Inventor)

    2008-01-01

    The present invention provides a practical method for UAVs to take advantage of thermals in a manner similar to piloted aircrafts and soaring birds. In general, the invention is a method for a UAV to autonomously locate a thermal and be guided to the thermal to greatly improve range and endurance of the aircraft.

  19. UAV Photogrammetry Implementation to Enhance Land Surveying, Comparisons and Possibilities

    Science.gov (United States)

    El Meouche, R.; Hijazi, I.; Poncet, P. A.; Abunemeh, M.; Rezoug, M.

    2016-10-01

    The use of Unmanned Aerial Vehicles (UAVs) for surveying is now widespread and operational for several applications - quarry monitoring, archeological site surveys, forest management and 3D modeling for buildings, for instance. UAV is increasingly used by land surveyors especially for those kinds of projects. It is still ambiguous whether UAV can be applicable for smaller sites and property division. Therefore, the objective of this research is to extract a vectorized plan utilizing a UAV for a small site and investigate the possibility of an official land surveyor exploiting and certificating it. To do that, two plans were created, one using a UAV and another utilizing classical land surveyor instruments (Total Station). A comparison was conducted between the two plans to evaluate the accuracy of the UAV technique compared to the classical one. Moreover, other parameters were also considered such as execution time and the surface covered. The main problems associated with using a UAV are the level of precision and the visualization of the whole area. The results indicated that the precision is quite satisfactory with a maximum error of 1.0 cm on ground control points, and 4 cm for the rest of the model. On the other hand, the results showed that it is not possible to represent the whole area of interest utilizing a UAV, due to vegetation.

  20. Formation Flight of Multiple UAVs via Onboard Sensor Information Sharing

    Directory of Open Access Journals (Sweden)

    Chulwoo Park

    2015-07-01

    Full Text Available To monitor large areas or simultaneously measure multiple points, multiple unmanned aerial vehicles (UAVs must be flown in formation. To perform such flights, sensor information generated by each UAV should be shared via communications. Although a variety of studies have focused on the algorithms for formation flight, these studies have mainly demonstrated the performance of formation flight using numerical simulations or ground robots, which do not reflect the dynamic characteristics of UAVs. In this study, an onboard sensor information sharing system and formation flight algorithms for multiple UAVs are proposed. The communication delays of radiofrequency (RF telemetry are analyzed to enable the implementation of the onboard sensor information sharing system. Using the sensor information sharing, the formation guidance law for multiple UAVs, which includes both a circular and close formation, is designed. The hardware system, which includes avionics and an airframe, is constructed for the proposed multi-UAV platform. A numerical simulation is performed to demonstrate the performance of the formation flight guidance and control system for multiple UAVs. Finally, a flight test is conducted to verify the proposed algorithm for the multi-UAV system.

  1. Formation Flight of Multiple UAVs via Onboard Sensor Information Sharing.

    Science.gov (United States)

    Park, Chulwoo; Cho, Namhoon; Lee, Kyunghyun; Kim, Youdan

    2015-07-17

    To monitor large areas or simultaneously measure multiple points, multiple unmanned aerial vehicles (UAVs) must be flown in formation. To perform such flights, sensor information generated by each UAV should be shared via communications. Although a variety of studies have focused on the algorithms for formation flight, these studies have mainly demonstrated the performance of formation flight using numerical simulations or ground robots, which do not reflect the dynamic characteristics of UAVs. In this study, an onboard sensor information sharing system and formation flight algorithms for multiple UAVs are proposed. The communication delays of radiofrequency (RF) telemetry are analyzed to enable the implementation of the onboard sensor information sharing system. Using the sensor information sharing, the formation guidance law for multiple UAVs, which includes both a circular and close formation, is designed. The hardware system, which includes avionics and an airframe, is constructed for the proposed multi-UAV platform. A numerical simulation is performed to demonstrate the performance of the formation flight guidance and control system for multiple UAVs. Finally, a flight test is conducted to verify the proposed algorithm for the multi-UAV system.

  2. Three-dimensional velocity obstacle method for UAV deconflicting maneuvers

    NARCIS (Netherlands)

    Jenie, Y.I.; Van Kampen, E.J.; De Visser, C.C.; Ellerbroek, J.; Hoekstra, J.M.

    2015-01-01

    Autonomous systems are required in order to enable UAVs to conduct self-separation and collision avoidance, especially for flights within the civil airspace system. A method called the Velocity Obstacle Method can provide the necessary situational awareness for UAVs in a dynamic environment, and can

  3. Review of the current state of UAV regulations

    NARCIS (Netherlands)

    Stöcker, Elvira Claudia; Bennett, Rohan; Nex, Francesco; Gerke, Markus; Zevenbergen, Jaap

    2017-01-01

    UAVs-unmanned aerial vehicles-facilitate data acquisition at temporal and spatial scales that still remain unachievable for traditional remote sensing platforms. However, current legal frameworks that regulate UAVs present significant barriers to research and development. To highlight the importance

  4. Vision-IMU based collaborative control of a blind UAV

    NARCIS (Netherlands)

    Hoogervorst, R.; Stramigioli, Stefano; Wopereis, Han Willem; Fumagalli, Matteo

    2015-01-01

    Position estimation of UAVs is usually done using onboard sensors such as GPS and camera. However, in certain practical situations, the measurements of both the GPS and the onboard camera of the UAV might not always be available or reliable. This paper investigates the possibility to overcome

  5. UAV PHOTOGRAMMETRY IMPLEMENTATION TO ENHANCE LAND SURVEYING, COMPARISONS AND POSSIBILITIES

    Directory of Open Access Journals (Sweden)

    R. El Meouche

    2016-10-01

    Full Text Available The use of Unmanned Aerial Vehicles (UAVs for surveying is now widespread and operational for several applications – quarry monitoring, archeological site surveys, forest management and 3D modeling for buildings, for instance. UAV is increasingly used by land surveyors especially for those kinds of projects. It is still ambiguous whether UAV can be applicable for smaller sites and property division. Therefore, the objective of this research is to extract a vectorized plan utilizing a UAV for a small site and investigate the possibility of an official land surveyor exploiting and certificating it. To do that, two plans were created, one using a UAV and another utilizing classical land surveyor instruments (Total Station. A comparison was conducted between the two plans to evaluate the accuracy of the UAV technique compared to the classical one. Moreover, other parameters were also considered such as execution time and the surface covered. The main problems associated with using a UAV are the level of precision and the visualization of the whole area. The results indicated that the precision is quite satisfactory with a maximum error of 1.0 cm on ground control points, and 4 cm for the rest of the model. On the other hand, the results showed that it is not possible to represent the whole area of interest utilizing a UAV, due to vegetation.

  6. Small UAV-Acquired, High-resolution, Georeferenced Still Imagery

    Energy Technology Data Exchange (ETDEWEB)

    Ryan Hruska

    2005-09-01

    Currently, small Unmanned Aerial Vehicles (UAVs) are primarily used for capturing and down-linking real-time video. To date, their role as a low-cost airborne platform for capturing high-resolution, georeferenced still imagery has not been fully utilized. On-going work within the Unmanned Vehicle Systems Program at the Idaho National Laboratory (INL) is attempting to exploit this small UAV-acquired, still imagery potential. Initially, a UAV-based still imagery work flow model was developed that includes initial UAV mission planning, sensor selection, UAV/sensor integration, and imagery collection, processing, and analysis. Components to support each stage of the work flow are also being developed. Critical to use of acquired still imagery is the ability to detect changes between images of the same area over time. To enhance the analysts’ change detection ability, a UAV-specific, GIS-based change detection system called SADI or System for Analyzing Differences in Imagery is under development. This paper will discuss the associated challenges and approaches to collecting still imagery with small UAVs. Additionally, specific components of the developed work flow system will be described and graphically illustrated using varied examples of small UAV-acquired still imagery.

  7. Development of a UAV rangeland remote sensing capability

    Science.gov (United States)

    Starting in 2000, experiments have been conducted at the Jornada Experimental Range near Las Cruces, NM to evaluate the utility of Unmanned Aerial Vehicles (UAVs) for applications on arid rangelands. When compared to all types of remote sensing research ongoing at Jornada and other locations, UAVs h...

  8. Pathloss Measurements and Modeling for UAVs Connected to Cellular Networks

    DEFF Research Database (Denmark)

    Amorim, Rafhael Medeiros de; Kovács, István; Sørensen, Troels Bundgaard

    2017-01-01

    This paper assess field measurements, as part of the investigation of the suitability of cellular networks for providing connectivity to UAVs (unmanned aerial vehicles). Evaluation is done by means of field measurements obtained in a rural environment in Denmark with an airbone UAV...

  9. Concept of Indoor 3D-Route UAV Scheduling System

    DEFF Research Database (Denmark)

    Khosiawan, Yohanes; Nielsen, Izabela Ewa; Do, Ngoc Ang Dung

    2016-01-01

    The objective of the proposed concept is to develop a methodology to support Unmanned Aerial Vehicles (UAVs) operation with a path planning and scheduling system in 3D environments. The proposed 3D path-planning and scheduling allows the system to schedule UAVs routing to perform tasks in 3D indoor...

  10. An Ecological Approach to the Supervisory Control of UAV Swarms

    NARCIS (Netherlands)

    Fuchs, C.; Borst, C.; De Croon, G.C.H.E.; Van Paassen, M.M.; Mulder, M.

    2014-01-01

    This research employs ecological interface design to improve the human machine interface of an existing ground control station for the supervisory control of UAV swarms. As a case study, a general ground surveillance mission with four UAVs is envisioned. An analysis of the swarming work domain is pe

  11. Vision-IMU based collaborative control of a blind UAV

    NARCIS (Netherlands)

    Hoogervorst, R.; Stramigioli, S.; Wopereis, H.W.; Fumagalli, M.

    2015-01-01

    Position estimation of UAVs is usually done using onboard sensors such as GPS and camera. However, in certain practical situations, the measurements of both the GPS and the onboard camera of the UAV might not always be available or reliable. This paper investigates the possibility to overcome situat

  12. Wing,tail,and vocal contributions to the complex acoustic signals of courting Calliope hummingbirds

    Institute of Scientific and Technical Information of China (English)

    Christopher James CLARK

    2011-01-01

    Multi-component signals contain multiple signal parts expressed in the same physical modality.One way to identify individual components is if they are produced by different physical mechanisms.Here,I studied the mechanisms generating acoustic signais in the courtship displays of the Calliope hummingbird Stellula calliope.Display dives consisted of three synchronized sound elements,a high-frequency tone(hft),a low frequency tone(lft),and atonal sound pulses(asp),which were then followed by a frequency-modulaled fall.Manipulating any of the rectrices(tail-feathers)of wild males impaired production of the lft and asp,but not the hft or fall,which are apparently vocal.I tested the sound production capabilities of the rectrices in a wind tuunel.Single rectrices could generate the lft but not the asp,whereas multiple rectrices tested together produced sounds similar to the asp when they fluttered and collided with their neighbors percussively,representing a previously unknown mechanism of sound production.During the shuttle display,a trill is generated by the wings during pulses in which the wingbeat frequency is elevated to 95 Hz,40% higher than the typical hovering wingbeat frequency.Tbe Caillope hummingbird courtship displays include sounds produced by three independent mechauisms,and thus include a minimum of three acoustic signal components.These acoustic mechanisms have different constraints and thus potentially contain different messages.Producing multiple acoustic signals via multiple mechanisms may be a way to escape the constraints present in any single mechanism.

  13. Design and Development of a Class of Rotorcraft-based UAV

    Directory of Open Access Journals (Sweden)

    Gyou Beom Kim

    2013-02-01

    Full Text Available We discuss the development of a mini‐quadrotor system and coaxial quadrotor system for indoor and outdoor applications. The attitude control system consists of a stability augmentation system and a modern control approach. To perform an experimental flight test, a PID controller is used to validate our aerodynamic modelling and basic electronics hardware is developed in a simple configuration. We use a low‐cost 100 Hz AHRS for inertial sensing, infrared (IR sensors for horizontal ranging, an ultrasonic sensor for ground ranging and an AVR microcontroller for the flight control computer. A ground control system is developed for the monitoring and gathering of flight data. Based on the modelling and simulation data of the mini‐quadrotor system, a flight test is performed and automatic hovering ability is implemented. A collision detection system is one of the important parts of an indoor and outdoor flight test. To overcome the payload limitation of the mini‐quadrotor system, we design a coaxial quadrotor system and we use a Kinect sensor as the collision detect sensor. Kinect sensors give 3D depth information and the collision detection system uses that information.

  14. Millimeter-wave micro-Doppler measurements of small UAVs

    Science.gov (United States)

    Rahman, Samiur; Robertson, Duncan A.

    2017-05-01

    This paper discusses the micro-Doppler signatures of small UAVs obtained from a millimeter-wave radar system. At first, simulation results are shown to demonstrate the theoretical concept. It is illustrated that whilst the propeller rotation rate of the small UAVs is quite high, millimeter-wave radar systems are capable of capturing the full micro-Doppler spread. Measurements of small UAVs have been performed with both CW and FMCW radars operating at 94 GHz. The CW radar was used for obtaining micro-Doppler signatures of individual propellers. The field test data of a flying small UAV was collected with the FMCW radar and was processed to extract micro-Doppler signatures. The high fidelity results clearly reveal features such as blade flashes and propeller rotation modulation lines which can be used to classify targets. This work confirms that millimeter-wave radar is suitable for the detection and classification of small UAVs at usefully long ranges.

  15. Biomimetic-Based Output Feedback for Attitude Stabilization of Rigid Bodies: Real-Time Experimentation on a Quadrotor

    Directory of Open Access Journals (Sweden)

    José Fermi Guerrero-Castellanos

    2015-08-01

    Full Text Available The present paper deals with the development of bounded feedback control laws mimicking the strategy adopted by flapping flyers to stabilize the attitude of systems falling within the framework of rigid bodies. Flapping flyers are able to orient their trajectory without any knowledge of their current attitude and without any attitude computation. They rely on the measurements of some sensitive organs: halteres, leg sensilla and magnetic sense, which give information about their angular velocity and the orientation of gravity and magnetic field vectors. Therefore, the proposed feedback laws are computed using direct inertial sensors measurements, that is vector observations with/without angular velocity measurements. Hence, the attitude is not explicitly required. This biomimetic approach is very simple, requires little computational power and is suitable for embedded applications on small control units. The boundedness of the control signal is taken into consideration through the design of the control laws by saturation of the actuators’ input. The asymptotic stability of the closed loop system is proven by Lyapunov analysis. Real-time experiments are carried out on a quadrotor using MEMS inertial sensors in order to emphasize the efficiency of this biomimetic strategy by showing the convergence of the body’s states in hovering mode, as well as the robustness with respect to external disturbances.

  16. Unmanned Aerial Vehicles (UAVs) on the Future Tactical Battlefield - Are UAVs and Essential Joint Force Multiplier?

    Science.gov (United States)

    1992-08-12

    MONOGRAPH APPROVAL Major Roald L. MOgoniale Title of Monograph: Untanned Aerial Vj!ji.UAVs) on the Future Tactical Battlefield - Are UAVa an Essential...New York: Hill and Wang , 1984. Lambeth, Benjamin S. Moscow’s Lessons Learned from the 1982 Lebanon Air War. Santa Monica, CA.: Rand Corporation, 1984

  17. A Networked Swarm Model for UAV Deployment in the Assessment of Forest Environments

    OpenAIRE

    Brust, Matthias R.; Strimbu, Bogdan M.

    2016-01-01

    Autonomous Unmanned Aerial Vehicles (UAVs) have gained popularity due to their many potential application fields. Alongside sophisticated sensors, UAVs can be equipped with communication adaptors aimed for inter-UAV communication. Inter-communication of UAVs to form a UAV swarm raises questions on how to manage its communication structure and mobility. In this paper, we consider therefore the problem of establishing an efficient swarm movement model and a network topology between a collection...

  18. Five new feather mites of the subfamily Pterodectinae (Acariformes: Astigmata: Proctophyllodidae) from passerines and hummingbirds (Aves) of Brazil.

    Science.gov (United States)

    Hernandes, Fabio Akashi; Pedroso, Luiz Gustavo A; Oniki-Willis, Yoshika

    2016-09-06

    Five new species of feather mites (Proctophyllodidae: Pterodectinae) are described from passerines and hummingbirds of Brazil: Amerodectes longifuscus sp. nov. from Poospiza lateralis (Nordmann, 1835) (Passeriformes: Emberizidae), A. vireonis sp. nov. from Vireo olivaceus (Linnaeus, 1766) (Passeriformes: Vireonidae), Tyrannidectes synallaxis sp. nov. from Synallaxis ruficapilla Vieillot, 1819 (Passeriformes: Furnariidae), Trochilodectes willisi sp. nov. from Phaethornis eurynome (Lesson, 1832) (Apodiformes: Trochilidae), and Xynonodectes phaethornis sp. nov. from Ph. pretrei (Lesson & Delattre, 1839) (Apodiformes: Trochilidae).

  19. Harmonic hopping, and both punctuated and gradual evolution of acoustic characters in Selasphorus hummingbird tail-feathers.

    Directory of Open Access Journals (Sweden)

    Christopher James Clark

    Full Text Available Models of character evolution often assume a single mode of evolutionary change, such as continuous, or discrete. Here I provide an example in which a character exhibits both types of change. Hummingbirds in the genus Selasphorus produce sound with fluttering tail-feathers during courtship. The ancestral character state within Selasphorus is production of sound with an inner tail-feather, R2, in which the sound usually evolves gradually. Calliope and Allen's Hummingbirds have evolved autapomorphic acoustic mechanisms that involve feather-feather interactions. I develop a source-filter model of these interactions. The 'source' comprises feather(s that are both necessary and sufficient for sound production, and are aerodynamically coupled to neighboring feathers, which act as filters. Filters are unnecessary or insufficient for sound production, but may evolve to become sources. Allen's Hummingbird has evolved to produce sound with two sources, one with feather R3, another frequency-modulated sound with R4, and their interaction frequencies. Allen's R2 retains the ancestral character state, a ∼1 kHz "ghost" fundamental frequency masked by R3, which is revealed when R3 is experimentally removed. In the ancestor to Allen's Hummingbird, the dominant frequency has 'hopped' to the second harmonic without passing through intermediate frequencies. This demonstrates that although the fundamental frequency of a communication sound may usually evolve gradually, occasional jumps from one character state to another can occur in a discrete fashion. Accordingly, mapping acoustic characters on a phylogeny may produce misleading results if the physical mechanism of production is not known.

  20. Reproductive biology and nectar production of the Mexican endemic Psittacanthus auriculatus (Loranthaceae), a hummingbird-pollinated mistletoe.

    Science.gov (United States)

    Pérez-Crespo, M J; Ornelas, J F; Martén-Rodríguez, S; González-Rodríguez, A; Lara, C

    2016-01-01

    Many mistletoe species produce 'bird'-pollinated flowers; however, the reproductive biology of the majority of these species has not been studied. Psittacanthus auriculatus is a Mexican endemic mistletoe, most common in open, dry mesquite grassland. Knowledge of the reproductive biology of P. auriculatus is essential for understanding species formation and diversification of Psittacanthus mistletoes, but it is currently poorly understood. Thus, we studied floral biology and phenology, nectar production and breeding system and pollination of this species. The hermaphroditic red-pink flowers open from the middle to the tip and petals are curly, but remain partially fused forming a floral tube of ca. 20-mm long. Flowers are partially protandrous, produce large amounts of nectar, last 2 days, and stigma receptivity is highest during the second day. We recorded hummingbirds (Cynanthus latirostris, Hylocharis leucotis, Amazilia beryllina, A. violiceps, Calothorax lucifer, Archilochus colubris) and less commonly butterflies (Agraulis vanillae, Anteos clorinde, Papilio multicaudatus, Phocides urania, Phoebis sennae) as floral visitors. P. auriculatus flowers are self-compatible. However, this mistletoe is an obligate animal-pollinated species, as the sensitive stigma avoids self-pollination. Under natural conditions, reproductive success was higher than in manually selfed or cross-pollinated flowers, likely due to the traplining foraging behaviour of hummingbirds. We suggest that the apparent efficient foraging behaviour of hummingbirds maintains gene flow among P. auriculatus, promoting outcrossing.

  1. Implications of inflorescence clustering for the visitation rate by hummingbirds and fruit production by Heliconia bihai (L. L. (Heliconiaceae

    Directory of Open Access Journals (Sweden)

    Caio César Corrêa Missagia

    2015-09-01

    Full Text Available Plant spatial distribution can influence the activity of floral visitors. Flower clustering in patches may be more attractive to visitors and it supposedly influences the fruit production. This study aimed to test the hypothesis that in Heliconia bihai (L. L. (Heliconiaceae the inflorescence clustering size positively influences the visitation rate and fruit production by the species. The study was conducted at a stretch of Atlantic Forest, in Rio de Janeiro city, Brazil. Five hummingbird species were registered as floral visitors. The average visitation rate (± standard deviation of hummingbirds was 2 (± 0.56 visits per hour per clustering. The amount of inflorescences per clustering positively influenced the visitation rate of hummingbirds, but it negatively influenced the amount of fruits produced per inflorescence. According to the results obtained, we suggest that the density of inflorescences in a clustering may negatively influence the number of flowers visited per inflorescence, due to an increased amount of inflorescences included in the foraging routes.

  2. Genetic architecture of pollination syndrome transition between hummingbird-specialist and generalist species in the genus Rhytidophyllum (Gesneriaceae

    Directory of Open Access Journals (Sweden)

    Hermine Alexandre

    2015-06-01

    Full Text Available Adaptation to pollinators is a key factor of diversification in angiosperms. The Caribbean sister genera Rhytidophyllum and Gesneria present an important diversification of floral characters. Most of their species can be divided in two major pollination syndromes. Large-open flowers with pale colours and great amount of nectar represent the generalist syndrome, while the hummingbird-specialist syndrome corresponds to red tubular flowers with a less important nectar volume. Repeated convergent evolution toward the generalist syndrome in this group suggests that such transitions rely on few genes of moderate to large effect. To test this hypothesis, we built a linkage map and performed a QTL detection for divergent pollination syndrome traits by crossing one specimen of the generalist species Rhytidophyllum auriculatum with one specimen of the hummingbird pollinated R. rupincola. Using geometric morphometrics and univariate traits measurements, we found that floral shape among the second-generation hybrids is correlated with morphological variation observed between generalist and hummingbird-specialist species at the genus level. The QTL analysis showed that colour and nectar volume variation between syndromes involve each one major QTL while floral shape has a more complex genetic basis and rely on few genes of moderate effect. Finally, we did not detect any genetic linkage between the QTLs underlying those traits. This genetic independence of traits could have facilitated evolution toward optimal syndromes.

  3. Specialization in plant-hummingbird networks is associated with species richness, contemporary precipitation and quaternary climate-change velocity.

    Directory of Open Access Journals (Sweden)

    Bo Dalsgaard

    Full Text Available Large-scale geographical patterns of biotic specialization and the underlying drivers are poorly understood, but it is widely believed that climate plays an important role in determining specialization. As climate-driven range dynamics should diminish local adaptations and favor generalization, one hypothesis is that contemporary biotic specialization is determined by the degree of past climatic instability, primarily Quaternary climate-change velocity. Other prominent hypotheses predict that either contemporary climate or species richness affect biotic specialization. To gain insight into geographical patterns of contemporary biotic specialization and its drivers, we use network analysis to determine the degree of specialization in plant-hummingbird mutualistic networks sampled at 31 localities, spanning a wide range of climate regimes across the Americas. We found greater biotic specialization at lower latitudes, with latitude explaining 20-22% of the spatial variation in plant-hummingbird specialization. Potential drivers of specialization--contemporary climate, Quaternary climate-change velocity, and species richness--had superior explanatory power, together explaining 53-64% of the variation in specialization. Notably, our data provides empirical evidence for the hypothesized roles of species richness, contemporary precipitation and Quaternary climate-change velocity as key predictors of biotic specialization, whereas contemporary temperature and seasonality seem unimportant in determining specialization. These results suggest that both ecological and evolutionary processes at Quaternary time scales can be important in driving large-scale geographical patterns of contemporary biotic specialization, at least for co-evolved systems such as plant-hummingbird networks.

  4. Fossil evidence of wing shape in a stem relative of swifts and hummingbirds (Aves, Pan-Apodiformes).

    Science.gov (United States)

    Ksepka, Daniel T; Clarke, Julia A; Nesbitt, Sterling J; Kulp, Felicia B; Grande, Lance

    2013-06-22

    A feathered specimen of a new species of Eocypselus from the Early Eocene Green River Formation of Wyoming provides insight into the wing morphology and ecology in an early part of the lineage leading to extant swifts and hummingbirds. Combined phylogenetic analysis of morphological and molecular data supports placement of Eocypselus outside the crown radiation of Apodiformes. The new specimen is the first described fossil of Pan-Apodiformes from the pre-Pleistocene of North America and the only reported stem taxon with informative feather preservation. Wing morphology of Eocypselus rowei sp. nov. is intermediate between the short wings of hummingbirds and the hyper-elongated wings of extant swifts, and shows neither modifications for the continuous gliding used by swifts nor modifications for the hovering flight style used by hummingbirds. Elongate hindlimb elements, particularly the pedal phalanges, also support stronger perching capabilities than are present in Apodiformes. The new species is the smallest bird yet described from the Green River Formation, and supports the hypothesis that a decrease in body size preceded flight specializations in Pan-Apodiformes. The specimen also provides the first instance of melanosome morphology preserved in association with skeletal remains from the Green River Formation.

  5. Specialization in Plant-Hummingbird Networks Is Associated with Species Richness, Contemporary Precipitation and Quaternary Climate-Change Velocity

    Science.gov (United States)

    Dalsgaard, Bo; Magård, Else; Fjeldså, Jon; Martín González, Ana M.; Rahbek, Carsten; Olesen, Jens M.; Ollerton, Jeff; Alarcón, Ruben; Cardoso Araujo, Andrea; Cotton, Peter A.; Lara, Carlos; Machado, Caio Graco; Sazima, Ivan; Sazima, Marlies; Timmermann, Allan; Watts, Stella; Sandel, Brody; Sutherland, William J.; Svenning, Jens-Christian

    2011-01-01

    Large-scale geographical patterns of biotic specialization and the underlying drivers are poorly understood, but it is widely believed that climate plays an important role in determining specialization. As climate-driven range dynamics should diminish local adaptations and favor generalization, one hypothesis is that contemporary biotic specialization is determined by the degree of past climatic instability, primarily Quaternary climate-change velocity. Other prominent hypotheses predict that either contemporary climate or species richness affect biotic specialization. To gain insight into geographical patterns of contemporary biotic specialization and its drivers, we use network analysis to determine the degree of specialization in plant-hummingbird mutualistic networks sampled at 31 localities, spanning a wide range of climate regimes across the Americas. We found greater biotic specialization at lower latitudes, with latitude explaining 20–22% of the spatial variation in plant-hummingbird specialization. Potential drivers of specialization - contemporary climate, Quaternary climate-change velocity, and species richness - had superior explanatory power, together explaining 53–64% of the variation in specialization. Notably, our data provides empirical evidence for the hypothesized roles of species richness, contemporary precipitation and Quaternary climate-change velocity as key predictors of biotic specialization, whereas contemporary temperature and seasonality seem unimportant in determining specialization. These results suggest that both ecological and evolutionary processes at Quaternary time scales can be important in driving large-scale geographical patterns of contemporary biotic specialization, at least for co-evolved systems such as plant-hummingbird networks. PMID:21998716

  6. Genetic architecture of pollination syndrome transition between hummingbird-specialist and generalist species in the genus Rhytidophyllum (Gesneriaceae).

    Science.gov (United States)

    Alexandre, Hermine; Vrignaud, Justine; Mangin, Brigitte; Joly, Simon

    2015-01-01

    Adaptation to pollinators is a key factor of diversification in angiosperms. The Caribbean sister genera Rhytidophyllum and Gesneria present an important diversification of floral characters. Most of their species can be divided in two major pollination syndromes. Large-open flowers with pale colours and great amount of nectar represent the generalist syndrome, while the hummingbird-specialist syndrome corresponds to red tubular flowers with a less important nectar volume. Repeated convergent evolution toward the generalist syndrome in this group suggests that such transitions rely on few genes of moderate to large effect. To test this hypothesis, we built a linkage map and performed a QTL detection for divergent pollination syndrome traits by crossing one specimen of the generalist species Rhytidophyllum auriculatum with one specimen of the hummingbird pollinated R. rupincola. Using geometric morphometrics and univariate traits measurements, we found that floral shape among the second-generation hybrids is correlated with morphological variation observed between generalist and hummingbird-specialist species at the genus level. The QTL analysis showed that colour and nectar volume variation between syndromes involve each one major QTL while floral shape has a more complex genetic basis and rely on few genes of moderate effect. Finally, we did not detect any genetic linkage between the QTLs underlying those traits. This genetic independence of traits could have facilitated evolution toward optimal syndromes.

  7. Exploring the boundary between pollination syndromes: bats and hummingbirds as pollinators of Burmeistera cyclostigmata and B. tenuiflora (Campanulaceae).

    Science.gov (United States)

    Muchhala, Nathan

    2003-02-01

    In this study I documented the degree of specialization in the pollination systems of Burmeistera cyclostigmata and B. tenuiflora (Campanulaceae) to explore the potential role of floral isolation in the diversification of the genus. I asked which floral characteristics are important in specializing on either bat or hummingbird pollination, and whether overlap between these floral syndromes can exist. I examined nocturnal and diurnal pollen deposition, pollinator visitation rates, and single visit effectiveness and related them to intra- and interspecific variation in Burmeistera floral characteristics at Monteverde, Costa Rica. Bats and hummingbirds visited both Burmeistera species, and bats pollinated both species. Owing to differences in floral morphology, however, hummingbirds effectively pollinated only B. tenuiflora. The generalized pollination system of B. tenuiflora demonstrates that there can be overlap in the boundary between ornithophily and chiropterophily, and that nectar production and timing of anthesis do not serve as barriers between these syndromes. The high intraspecific variation in floral color from green to red or purple did not correlate with either nocturnal or diurnal pollen deposition. Degree of flower accessibility did affect pollination; nocturnal pollen deposition significantly decreased as flowers become more obstructed. In Burmeistera, floral morphology and accessibility appear to be the most important floral characteristics for specialization at the boundary between ornithophily and chiropterophily.

  8. Specialization in plant-hummingbird networks is associated with species richness, contemporary precipitation and quaternary climate-change velocity.

    Science.gov (United States)

    Dalsgaard, Bo; Magård, Else; Fjeldså, Jon; Martín González, Ana M; Rahbek, Carsten; Olesen, Jens M; Ollerton, Jeff; Alarcón, Ruben; Cardoso Araujo, Andrea; Cotton, Peter A; Lara, Carlos; Machado, Caio Graco; Sazima, Ivan; Sazima, Marlies; Timmermann, Allan; Watts, Stella; Sandel, Brody; Sutherland, William J; Svenning, Jens-Christian

    2011-01-01

    Large-scale geographical patterns of biotic specialization and the underlying drivers are poorly understood, but it is widely believed that climate plays an important role in determining specialization. As climate-driven range dynamics should diminish local adaptations and favor generalization, one hypothesis is that contemporary biotic specialization is determined by the degree of past climatic instability, primarily Quaternary climate-change velocity. Other prominent hypotheses predict that either contemporary climate or species richness affect biotic specialization. To gain insight into geographical patterns of contemporary biotic specialization and its drivers, we use network analysis to determine the degree of specialization in plant-hummingbird mutualistic networks sampled at 31 localities, spanning a wide range of climate regimes across the Americas. We found greater biotic specialization at lower latitudes, with latitude explaining 20-22% of the spatial variation in plant-hummingbird specialization. Potential drivers of specialization--contemporary climate, Quaternary climate-change velocity, and species richness--had superior explanatory power, together explaining 53-64% of the variation in specialization. Notably, our data provides empirical evidence for the hypothesized roles of species richness, contemporary precipitation and Quaternary climate-change velocity as key predictors of biotic specialization, whereas contemporary temperature and seasonality seem unimportant in determining specialization. These results suggest that both ecological and evolutionary processes at Quaternary time scales can be important in driving large-scale geographical patterns of contemporary biotic specialization, at least for co-evolved systems such as plant-hummingbird networks.

  9. Attitude Optimal Backstepping Controller Based Quaternion for a UAV

    Directory of Open Access Journals (Sweden)

    Kaddouri Djamel

    2016-01-01

    Full Text Available A hierarchical controller design based on nonlinear H∞ theory and backstepping technique is developed for a nonlinear and coupled dynamic attitude system using conventional quaternion based method. The derived controller combines the attractive features of H∞ optimal controller and the advantages of the backstepping technique leading to a control law which avoids winding phenomena. Performance issues of the controller are illustrated in a simulation study made for a four-rotor vertical take-off and landing (VTOL aerial robot prototype known as the quadrotor aircraft.

  10. The Parrot UAV Controlled by PID Controllers

    Directory of Open Access Journals (Sweden)

    Koszewnik Andrzej

    2014-08-01

    Full Text Available The paper presents the process of modeling and designing control laws for four-rotor type of the Parrot UAV. The state space model is obtained by using several phenomena like gyroscopic effects for rigid bodies, propellers and rotors. The obtained model has been used to design PID control laws for roll, pitch, yaw angle and altitude, respectively. The numerical simulations of the closed loop model are shown that system in satisfy way stabilize flight of the quadro-rotor in all considered directions.

  11. Upwind dynamic soaring of albatrosses and UAVs

    Science.gov (United States)

    Richardson, Philip L.

    2015-01-01

    Albatrosses have been observed to soar in an upwind direction using what is called here an upwind mode of dynamic soaring. The upwind mode was modeled using the dynamics of a two-layer Rayleigh cycle in which the lower layer has zero velocity and the upper layer has a uniform wind speed of W. The upwind mode consists of a climb across the wind-shear layer headed upwind, a 90° turn and descent across the wind-shear layer perpendicular to the wind, followed by a 90° turn into the wind. The increase of airspeed gained from crossing the wind-shear layer headed upwind was balanced by the decrease of airspeed caused by drag. Results show that a wandering albatross can soar over the ocean in an upwind direction at a mean speed of 8.4 m/s in a 3.6 m/s wind, which is the minimum wind speed necessary for sustained dynamic soaring. A main result is that albatrosses can soar upwind much faster than the wind speed. Furthermore, albatrosses were found to be able to increase upwind speeds in winds greater than 3.6 m/s, reaching an upwind speed of 12.1 m/s in a wind speed of 7 m/s (for example). The upwind dynamic soaring mode of a possible robotic albatross UAV (Unmanned Aerial Vehicle) was modeled using a Rayleigh cycle and characteristics of a high-performance glider. Maximum possible airspeeds are equal to approximately 9.5 times the wind speed of the upper layer. In a wind of 10 m/s, the maximum possible upwind (56 m/s) and across-wind (61 m/s) components of UAV velocity over the ocean result in a diagonal upwind velocity of 83 m/s. In sufficient wind, a UAV could, in principle, use fast diagonal speeds to rapidly survey large areas of the ocean surface and the marine boundary layer. In practice, the maximum speeds of a UAV soaring over the ocean could be significantly less than these predictions. Some limitations to achieving fast travel velocities over the ocean are discussed and suggestions are made for further studies to test the concept of a robotic albatross.

  12. Swarms of UAVs and fighter aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Trahan, M.W.; Wagner, J.S.; Stantz, K.M.; Gray, P.C.; Robinett, R.

    1998-11-01

    This paper describes a method of modeling swarms of UAVs and/or fighter aircraft using particle simulation concepts. Recent investigations into the use of genetic algorithms to design neural networks for the control of autonomous vehicles (i.e., robots) led to the examination of methods of simulating large collections of robots. This paper describes the successful implementation of a model of swarm dynamics using particle simulation concepts. Several examples of the complex behaviors achieved in a target/interceptor scenario are presented.

  13. Coordinating UAV information for executing national security-oriented collaboration

    Science.gov (United States)

    Isenor, Anthony W.; Allard, Yannick; Lapinski, Anna-Liesa S.; Demers, Hugues; Radulescu, Dan

    2014-10-01

    Unmanned Aerial Vehicles (UAVs) are being used by numerous nations for defence-related missions. In some cases, the UAV is considered a cost-effective means to acquire data such as imagery over a location or object. Considering Canada's geographic expanse, UAVs are also being suggested as a potential platform for use in surveillance of remote areas, such as northern Canada. However, such activities are typically associated with security as opposed to defence. The use of a defence platform for security activities introduces the issue of information exchange between the defence and security communities and their software applications. This paper explores the flow of information from the system used by the UAVs employed by the Royal Canadian Navy. Multiple computers are setup, each with the information system used by the UAVs, including appropriate communication between the systems. Simulated data that may be expected from a typical maritime UAV mission is then fed into the information system. The information structures common to the Canadian security community are then used to store and transfer the simulated data. The resulting data flow from the defence-oriented UAV system to the security-oriented information structure is then displayed using an open source geospatial application. Use of the information structures and applications relevant to the security community avoids the distribution restrictions often associated with defence-specific applications.

  14. Vision Based Obstacle Detection mechanism of a Fixed Wing UAV

    Directory of Open Access Journals (Sweden)

    S.N. Omkar

    2014-03-01

    Full Text Available In this paper we have developed a vision based navigation and obstacle detection mechanism for unmanned aerial vehicles (UAVs which can be used effectively in GPS denied regions as well as in regions where remote controlled UAV navigation is impossible thus making the UAV more versatile and fully autonomous. We used a fixed single onboard video camera on the UAV that extracts images of the environment of a UAV. These images are then processed and detect an obstacle in the path if any. This method is effective in detecting dark as well as light coloured obstacles in the vicinity of the UAV. We developed two algorithms. The first one is to detect the horizon and land in the images extracted from the camera and to detect an obstacle in its path. The second one is specifically to detect a light coloured obstacle in the environment thus making our method more precise. The time taken for processing of the images and generating a result is very small thus this algorithm is also fit to be used in real time applications. These Algorithms are more effective than previously developed in this field because this algorithm does the detection of any obstacle without knowing the size of it beforehand. This algorithm is also capable of detecting light coloured obstacles in the sky which otherwise might be missed by an UAV or even a human pilot sometimes. Thus it makes the navigation more precise.

  15. Flight safety measurements of UAVs in congested airspace

    Institute of Scientific and Technical Information of China (English)

    Xiang Jinwu; Liu Yang; Luo Zhangping

    2016-01-01

    Describing spatial safety status is crucial for high-density air traffic involving multiple unmanned aerial vehicles (UAVs) in a complex environment. A probabilistic approach is proposed to measure safety situation in congested airspace. The occupancy distribution of the airspace is represented with conflict probability between spatial positions and UAV. The concept of a safety envelope related to flight performance and response time is presented first instead of the conventional fixed-size protected zones around aircraft. Consequently, the conflict probability is performance-dependent, and effects of various UAVs on safety can be distinguished. The uncer-tainty of a UAV future position is explicitly accounted for as Brownian motion. An analytic approximate algorithm for the conflict probability is developed to decrease the computational consumption. The relationship between safety and flight performance are discussed for different response times and prediction intervals. To illustrate the applications of the approach, an experi-ment of three UAVs in formation flight is performed. In addition, an example of trajectory planning is simulated for one UAV flying over airspace where five UAVs exist. The validation of the approach shows its potential in guaranteeing flight safety in highly dynamic environment.

  16. Experiences of Uav Surveys Applied to Environmental Risk Management

    Science.gov (United States)

    Caprioli, M.; Trizzino, R.; Mazzone, F.; Scarano, M.

    2016-06-01

    In this paper the results of some surveys carried out in an area of Apulian territory affected by serious environmental hazard are presented. Unmanned Aerial Vehicles (UAV) are emerging as a key engineering tool for future environmental survey tasks. UAVs are increasingly seen as an attractive low-cost alternative or supplement to aerial and terrestrial photogrammetry due to their low cost, flexibility, availability and readiness for duty. In addition, UAVs can be operated in hazardous or temporarily inaccessible locations, that makes them very suitable for the assessment and management of environmental risk conditions. In order to verify the reliability of these technologies an UAV survey and A LIDAR survey have been carried outalong about 1 km of coast in the Salento peninsula, near the towns of San Foca, Torre dellOrso and SantAndrea( Lecce, Southern Italy). This area is affected by serious environmental risks due to the presence of dangerous rocky cliffs named falesie. The UAV platform was equipped with a photogrammetric measurement system that allowed us to obtain a mobile mapping of the fractured fronts of dangerous rocky cliffs. UAV-images data have been processed using dedicated software (AgisoftPhotoscan). The point clouds obtained from both the UAV and LIDAR surveys have been processed using Cloud Compare software, with the aim of testing the UAV results with respect to the LIDAR ones. The total error obtained was of centimeter-order that is a very satisfactory result. The environmental information has been arranged in an ArcGIS platform in order to assess the risk levels. The possibility to repeat the survey at time intervals more or less close together depending on the measured levels of risk and to compare the output allows following the trend of the dangerous phenomena. In conclusion, for inaccessible locations of dangerous rocky bodies the UAV survey coupled with GIS methodology proved to be a key engineering tool for the management of environmental

  17. Velocity control of mini-UAV using a helmet system

    OpenAIRE

    Téllez-Guzmán, J. J.; Gomez-Balderas, Jose-Ernesto; Marchand, Nicolas; Castillo, Pedro; Colmenares Vazquez, J; Álvarez-Muñoz, J. U.; Dumon, Jonathan

    2015-01-01

    International audience; The usage of a helmet to command a mini-unmanned aerial vehicle (mini-UAV), is a telepresence system that connects the operator to the vehicle. This paper proposes a system which remotely allows the connection of a pilot's head motion and the 3D movements of a mini-UAVs. Two velocity control algorithms have been tested in order to manipulate the system. Results demonstrate that these movements can be used as reference inputs of the controller of the mini-UAV.

  18. Current development of UAV sense and avoid system

    Science.gov (United States)

    Zhahir, A.; Razali, A.; Mohd Ajir, M. R.

    2016-10-01

    As unmanned aerial vehicles (UAVs) are now gaining high interests from civil and commercialised market, the automatic sense and avoid (SAA) system is currently one of the essential features in research spotlight of UAV. Several sensor types employed in current SAA research and technology of sensor fusion that offers a great opportunity in improving detection and tracking system are presented here. The purpose of this paper is to provide an overview of SAA system development in general, as well as the current challenges facing UAV researchers and designers.

  19. Concept of Indoor 3D-Route UAV Scheduling System

    DEFF Research Database (Denmark)

    Khosiawan, Yohanes; Nielsen, Izabela Ewa; Do, Ngoc Ang Dung;

    2016-01-01

    environment. On top of that, the multi-source productive best-first-search concept also supports efficient real-time scheduling in response to uncertain events. Without human intervention, the proposed work provides an automatic scheduling system for UAV routing problem in 3D indoor environment.......The objective of the proposed concept is to develop a methodology to support Unmanned Aerial Vehicles (UAVs) operation with a path planning and scheduling system in 3D environments. The proposed 3D path-planning and scheduling allows the system to schedule UAVs routing to perform tasks in 3D indoor...

  20. Flower morphology, nectar features, and hummingbird visitation to Palicourea crocea (Rubiaceae in the Upper Paraná River floodplain, Brazil

    Directory of Open Access Journals (Sweden)

    Luciana B. Mendonça

    2006-03-01

    Full Text Available We investigated flower morphology, nectar features, and hummingbird visitation to Palicourea crocea (Rubiaceae, a common ornithophilous shrub found in the riparian forest understory in the Upper Paraná River floodplain, Brazil. Flowers are distylous and the style-stamen dimorphism is accompanied by other intermorph dimorphisms in corolla length, anther length, and stigma lobe length and form. We did not observe strict reciprocity in the positioning of stigma and anthers between floral morphs. Flowering occurred during the rainy season, October to December. Nectar standing crop per flowerwas relatively constant throughout the day, which apparently resulted in hummingbirds visiting the plant throughout the day. Energetic content of the nectar in each flower (66.5J and that required daily by hummingbird visitors (up to 30kJ would oblige visits to hundreds of flowers each day, and thus movements between plants that should result in pollen flow. Three hummingbird species visited the flowers: the Gilded Sapphire (Hylocharis chrysura, the Black-throated Mango (Anthracothorax nigricollis, and the Glittering-bellied Emerald (Chlorostilbon aureoventris. The frequency of hummingbird visitation, nectar features, and the scarcity of other hummingbird-visited flowers in the study area, indicate that P. crocea is an important nectar resource for short-billed hummingbirds in the study site.Investigamos a morfologia floral, as características do néctar e a visita de beija-flores a Palicourea crocea (Rubiaceae, uma espécie ornitófila arbustiva comumente encontrada no sub-bosque da vegetação ripária na planície de inundação do Alto Rio Paraná, Brasil. As flores são distílicas, sendo o dimorfismo estilete-estames acompanhado por outras variações morfológicas no comprimento da corola, altura das anteras, comprimento das anteras e comprimento e forma das papilas estigmáticas. Não foi observada reciprocidade estrita na posição dos estigmas e

  1. Connectivity Maintenance Based on Multiple Relay UAVs Selection Scheme in Cooperative Surveillance

    Directory of Open Access Journals (Sweden)

    Qian Zhu

    2016-12-01

    Full Text Available For the purpose of remote command and situation awareness, multiple unmanned aerial vehicles (UAVs cooperative surveillance with a ground station via multihop communications is presented in this paper. Considering limited communication capacities, a reliable UAV-to-UAV communication relay chain is dynamically established for connectivity maintenance and real-time surveillance information transmission. Firstly, a multiple UAVs cooperative surveillance framework is constructed with history detection information and surveillance payoff estimation. Secondly, four attributes are proposed to characterize differences among UAV alternatives in communication network containing a ground station, and a novel multiple relay UAVs selection scheme based on fuzzy optimum selection is developed to achieve tradeoff between surveillance mission and connectivity maintenance. Furthermore, satisfied with collision avoidance, limited communication and UAV kinematic constraints, the optimal UAV motion plan is obtained by decentralized receding horizon control, which is solved by particle swarm optimization with elite mechanism. Simulations demonstrate the effectiveness of the proposed methods in multi UAVs cooperative surveillance.

  2. Research on UAV Intelligent Obstacle Avoidance Technology During Inspection of Transmission Line

    Science.gov (United States)

    Wei, Chuanhu; Zhang, Fei; Yin, Chaoyuan; Liu, Yue; Liu, Liang; Li, Zongyu; Wang, Wanguo

    Autonomous obstacle avoidance of unmanned aerial vehicle (hereinafter referred to as UAV) in electric power line inspection process has important significance for operation safety and economy for UAV intelligent inspection system of transmission line as main content of UAV intelligent inspection system on transmission line. In the paper, principles of UAV inspection obstacle avoidance technology of transmission line are introduced. UAV inspection obstacle avoidance technology based on particle swarm global optimization algorithm is proposed after common obstacle avoidance technologies are studied. Stimulation comparison is implemented with traditional UAV inspection obstacle avoidance technology which adopts artificial potential field method. Results show that UAV inspection strategy of particle swarm optimization algorithm, adopted in the paper, is prominently better than UAV inspection strategy of artificial potential field method in the aspects of obstacle avoidance effect and the ability of returning to preset inspection track after passing through the obstacle. An effective method is provided for UAV inspection obstacle avoidance of transmission line.

  3. Unmanned aerial vehicles (UAVs) in pest management: Progress in the development of a UAV-deployed mating disruption system for Wisconsin cranberries

    Science.gov (United States)

    Unmanned aerial vehicles (UAVs) represent a powerful new tool for agriculture. Currently, UAVs are used almost exclusively as crop reconnaissance devices (“eyes in the sky”), not as pest control delivery systems. Research in Wisconsin cranberries is taking UAVs in a new direction. The Steffan and Lu...

  4. UAV-MAPPING – A USER REPORT

    Directory of Open Access Journals (Sweden)

    W. Mayr

    2012-09-01

    Full Text Available This paper reports on first hand experiences in operating an unmanned airborne system (UAS for mapping purposes in the environment of a mapping company. Recently, a multitude of activities in UAVs is visible, and there is growing interest in the commercial, industrial, and academic mapping user communities and not only in those. As an introduction, the major components of an UAS are identified. The paper focuses on a 1.1kg UAV which is integrated and gets applied on a day-to-day basis as part of an UAS in standard aerial imaging tasks for more than two years already. We present the unmanned airborne vehicle in some detail as well as the overall system components such as autopilot, ground station, flight mission planning and control, and first level image processing. The paper continues with reporting on experiences gained in setting up constraints such a system needs to fulfill. Further on, operational aspects with emphasis on unattended flight mission mode are presented. Various examples show the applicability of UAS in geospatial tasks, proofing that UAS are capable delivering reliably e.g. orthomosaics, digital surface models and more. Some remarks on achieved accuracies give an idea on obtainable qualities. A discussion about safety features puts some light on important matters when entering unmanned flying activities and rounds up this paper. Conclusions summarize the state of the art of an operational UAS from the point of the view of the author.

  5. Structured Robust Control for Small UAV

    Directory of Open Access Journals (Sweden)

    Elfatih G. HAMDI

    2015-06-01

    Full Text Available The performance and dynamic stability issues of flight control systems are still considered one of the most challenging design problems even though all of significant advances that have been happened in UAVs in the two last decades. This paper is devoted to design a flight control system to stabilize the attitude of small UAV against additive uncertainties. Toward this objective, structured robust control framework is considered. The design procedure is performed using two control configurations: The single degree of freedom (SDOF controller is considered and then followed by the two degree of freedom (TDOF controller to achieve some advantages. In SDOF configuration the entire set of all stabilizing controllers are, graphically, computed and then the controller parameter are, arbitrary, selected. A trade-off between designs requirements in SDOF controller determines the use of the TDOF controller. Therefore, the obtained parameters from SDOF controller are taken as initial guess and tuned using TDOF decentralized control to achieve the pre-determined performance specifications, while guarantee pre-determined robust stability. The obtained results clarify the ability of the designed controller to achieve an adequate level of stability and performance properties.

  6. Volcanic Plume Measurements with UAV (Invited)

    Science.gov (United States)

    Shinohara, H.; Kaneko, T.; Ohminato, T.

    2013-12-01

    Volatiles in magmas are the driving force of volcanic eruptions and quantification of volcanic gas flux and composition is important for the volcano monitoring. Recently we developed a portable gas sensor system (Multi-GAS) to quantify the volcanic gas composition by measuring volcanic plumes and obtained volcanic gas compositions of actively degassing volcanoes. As the Multi-GAS measures variation of volcanic gas component concentrations in the pumped air (volcanic plume), we need to bring the apparatus into the volcanic plume. Commonly the observer brings the apparatus to the summit crater by himself but such measurements are not possible under conditions of high risk of volcanic eruption or difficulty to approach the summit due to topography etc. In order to overcome these difficulties, volcanic plume measurements were performed by using manned and unmanned aerial vehicles. The volcanic plume measurements by manned aerial vehicles, however, are also not possible under high risk of eruption. The strict regulation against the modification of the aircraft, such as installing sampling pipes, also causes difficulty due to the high cost. Application of the UAVs for the volcanic plume measurements has a big advantage to avoid these problems. The Multi-GAS consists of IR-CO2 and H2O gas analyzer, SO2-H2O chemical sensors and H2 semiconductor sensor and the total weight ranges 3-6 kg including batteries. The necessary conditions of the UAV for the volcanic plumes measurements with the Multi-GAS are the payloads larger than 3 kg, maximum altitude larger than the plume height and installation of the sampling pipe without contamination of the exhaust gases, as the exhaust gases contain high concentrations of H2, SO2 and CO2. Up to now, three different types of UAVs were applied for the measurements; Kite-plane (Sky Remote) at Miyakejima operated by JMA, Unmanned airplane (Air Photo Service) at Shinomoedake, Kirishima volcano, and Unmanned helicopter (Yamaha) at Sakurajima

  7. Historical and current introgression in a Mesoamerican hummingbird species complex: a biogeographic perspective

    Directory of Open Access Journals (Sweden)

    Rosa Alicia Jiménez

    2016-01-01

    Full Text Available The influence of geologic and Pleistocene glacial cycles might result in morphological and genetic complex scenarios in the biota of the Mesoamerican region. We tested whether berylline, blue-tailed and steely-blue hummingbirds, Amazilia beryllina, Amazilia cyanura and Amazilia saucerottei, show evidence of historical or current introgression as their plumage colour variation might suggest. We also analysed the role of past and present climatic events in promoting genetic introgression and species diversification. We collected mitochondrial DNA (mtDNA sequence data and microsatellite loci scores for populations throughout the range of the three Amazilia species, as well as morphological and ecological data. Haplotype network, Bayesian phylogenetic and divergence time inference, historical demography, palaeodistribution modelling, and niche divergence tests were used to reconstruct the evolutionary history of this Amazilia species complex. An isolation-with-migration coalescent model and Bayesian assignment analysis were assessed to determine historical introgression and current genetic admixture. mtDNA haplotypes were geographically unstructured, with haplotypes from disparate areas interdispersed on a shallow tree and an unresolved haplotype network. Assignment analysis of the nuclear genome (nuDNA supported three genetic groups with signs of genetic admixture, corresponding to: (1 A. beryllina populations located west of the Isthmus of Tehuantepec; (2 A. cyanura populations between the Isthmus of Tehuantepec and the Nicaraguan Depression (Nuclear Central America; and (3 A. saucerottei populations southeast of the Nicaraguan Depression. Gene flow and divergence time estimates, and demographic and palaeodistribution patterns suggest an evolutionary history of introgression mediated by Quaternary climatic fluctuations. High levels of gene flow were indicated by mtDNA and asymmetrical isolation-with-migration, whereas the microsatellite analyses

  8. A hardware/software architecture for UAV payload and mission control

    OpenAIRE

    Pastor Llorens, Enric; López Rubio, Juan; Royo Chic, Pablo

    2006-01-01

    This paper presents an embedded hardware/software architecture specially designed to be applied on mini/micro Unmanned Aerial Vehicles (UAV). An UAV is low-cost non-piloted airplane designed to operate in D-cube (Dangerous- Dirty-Dull) situations [8]. Many types of UAVs exist today; however with the advent of UAV's civil applications, the class of mini/micro UAVs is emerging as a valid option in a commercial scenario. This type of UAV shares limitations with most...

  9. Application of Unmanned Air Vehicles (UAV) in monitoring of terrestrial habitats

    DEFF Research Database (Denmark)

    Sørensen, Peter Borgen; Strandberg, Beate; Bak, Jesper Leth

    2015-01-01

    I the last years there have been high focus on UAVs (drones) for many civil purposes and UAVs are also increasingly used for ecological data gathering. This presentation will first make an appetizer to show the new possibilities of using UAVs. The traditional concept of separating “data” that are......I the last years there have been high focus on UAVs (drones) for many civil purposes and UAVs are also increasingly used for ecological data gathering. This presentation will first make an appetizer to show the new possibilities of using UAVs. The traditional concept of separating “data...

  10. Performance Evaluation of 3d Modeling Software for Uav Photogrammetry

    Science.gov (United States)

    Yanagi, H.; Chikatsu, H.

    2016-06-01

    UAV (Unmanned Aerial Vehicle) photogrammetry, which combines UAV and freely available internet-based 3D modeling software, is widely used as a low-cost and user-friendly photogrammetry technique in the fields such as remote sensing and geosciences. In UAV photogrammetry, only the platform used in conventional aerial photogrammetry is changed. Consequently, 3D modeling software contributes significantly to its expansion. However, the algorithms of the 3D modelling software are black box algorithms. As a result, only a few studies have been able to evaluate their accuracy using 3D coordinate check points. With this motive, Smart3DCapture and Pix4Dmapper were downloaded from the Internet and commercial software PhotoScan was also employed; investigations were performed in this paper using check points and images obtained from UAV.

  11. Design of UAV high resolution image transmission system

    Science.gov (United States)

    Gao, Qiang; Ji, Ming; Pang, Lan; Jiang, Wen-tao; Fan, Pengcheng; Zhang, Xingcheng

    2017-02-01

    In order to solve the problem of the bandwidth limitation of the image transmission system on UAV, a scheme with image compression technology for mini UAV is proposed, based on the requirements of High-definition image transmission system of UAV. The video codec standard H.264 coding module and key technology was analyzed and studied for UAV area video communication. Based on the research of high-resolution image encoding and decoding technique and wireless transmit method, The high-resolution image transmission system was designed on architecture of Android and video codec chip; the constructed system was confirmed by experimentation in laboratory, the bit-rate could be controlled easily, QoS is stable, the low latency could meets most applied requirement not only for military use but also for industrial applications.

  12. HIL Tuning of UAV for Exploration of Risky Environments

    Directory of Open Access Journals (Sweden)

    C. D. Melita

    2008-11-01

    Full Text Available In this paper the latest results of an HIL architecture, optimized to develop and test UAV platforms are presented. This architecture has been used to realize the different devices involved in the navigation and stability control of the Volcan UAV, a plane designed to operate in volcanic environments. The proposed architecture is strongly modular and flexible and allows the development of avionic hardware and software, testing and tuning the involved algorithms with non-destructive trials. A flight simulator (X-Plane with a suitable plane model and plug-in, has been adopted to simulate the UAV dynamics. The flight simulator, interfaced with the real electronic boards, allows an easy tuning of all the control parameters and data collecting for test and validation. The effectiveness of adopted methodology was confirmed by several flight tests performed subsequently by using the designed avionic modules on the real UAV.

  13. Small VTOL UAV Acoustics Measurement and Prediction Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Interest in civilian use of small Unmanned Aerial Vehicles (UAVs) with Vertical Takeoff and Landing (VTOL) capability has increased greatly in recent years, and is...

  14. UAV Based Imaging for Crop, Weed and Disease Monitoring

    DEFF Research Database (Denmark)

    Garcia Ruiz, Francisco Jose

    Summary Unmanned aerial vehicles (UAV) equipped with cameras have become a powerful technology to collect high resolution remote sensing data from agricultural crops. When equipped with multispectral cameras, light invisible for the human eye may be captured and used to characterize...... with UAV-based remote sensing for practical use in agriculture and to contribute to the incipient research on UAV based remote sensing for agricultural applications. Three case studies were performed to (1) Characterize the spectral signatures of sugar beet (Beta vulgaris L.) and creeping thistle (Cirsium...... arvensis L.) and to investigate the possibilities of spectral based discrimination of the species. (2) To perform image based classification of crop-weed in sugar beet crops and health status in orange tree orchards and (3) to describe crop cover heterogeneity from images acquired with UAV. This thesis...

  15. Ultra Compact Cloud Physics Lidar for UAV Platforms Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We have designed a compact two-color, polarization-sensitive instrument to measure cloud characteristics from a high altitude UAV and can also be widely deployed as...

  16. Next Generation, UAV-Class Ozone Photometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Physical Sciences Inc. proposes to develop a compact, rugged, rapid-response, autonomous sensor for in-situ monitoring of ambient O3 from UAVs. Our innovation is to...

  17. Network Centric Transponders for Airspace Integration of UAVs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A method and device for situational awareness for unmanned air vehicles is presented. This enables integration of UAVs into the national airspace in a safe manner,...

  18. Ultra Compact Cloud Physics Lidar for UAV Platforms Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a compact two color, polarization sensitive instrument to measure cloud characteristics from high altitude UAV and can also be widely deployed as...

  19. Lidar-equipped uav for building information modelling

    Science.gov (United States)

    Roca, D.; Armesto, J.; Lagüela, S.; Díaz-Vilariño, L.

    2014-06-01

    The trend to minimize electronic devices in the last decades accounts for Unmanned Airborne Vehicles (UAVs) as well as for sensor technologies and imaging devices, resulting in a strong revolution in the surveying and mapping industries. However, only within the last few years the LIDAR sensor technology has achieved sufficiently reduction in terms of size and weight to be considered for UAV platforms. This paper presents an innovative solution to capture point cloud data from a Lidar-equipped UAV and further perform the 3D modelling of the whole envelope of buildings in BIM format. A mini-UAV platform is used (weigh less than 5 kg and up to 1.5 kg of sensor payload), and data from two different acquisition methodologies is processed and compared with the aim at finding the optimal configuration for the generation of 3D models of buildings for energy studies

  20. Estimation of UAV Position with Use of Smoothing Algorithms

    Directory of Open Access Journals (Sweden)

    Kaniewski Piotr

    2017-03-01

    Full Text Available The paper presents methods of on-line and off-line estimation of UAV position on the basis of measurements from its integrated navigation system. The navigation system installed on board UAV contains an INS and a GNSS receiver. The UAV position, as well as its velocity and orientation are estimated with the use of smoothing algorithms. For off-line estimation, a fixed-interval smoothing algorithm has been applied. On-line estimation has been accomplished with the use of a fixed-lag smoothing algorithm. The paper includes chosen results of simulations demonstrating improvements of accuracy of UAV position estimation with the use of smoothing algorithms in comparison with the use of a Kalman filter.

  1. Fuzzy Logic Based Resource Manager for a Team of UAVs

    Science.gov (United States)

    2006-06-01

    mine new optimal trajectories in real-time subject to changingfuz i e algoriths o c o conditions. Also, the control algorithm on the UAVs will al...9] J.F. Smith III; " Genetic Program Based Data Mining for to make meteorological measurements have been developed. Fuzzy Decision Trees ", in...for Fuzzy Decision three types of automatic cooperation between UAVs. Meth- Tree Structure with a Genetic Program," in Proceedings ofthe ods of

  2. Detection of small UAV helicopters using micro-Doppler

    Science.gov (United States)

    Tahmoush, David

    2014-05-01

    The detection of small unmanned aerial vehicles (UAVs) using radar can be challenging due to the small radar cross section and the presence of false targets such as birds. We present the initial results of micro-Doppler radar data collected on a small helicopter at G-band and compare the results to previously measured birds. The resulting signature differences can be used to help discriminate small UAVs from naturally occurring moving clutter such as birds.

  3. Genetic, ecological and morphological divergence between populations of the endangered Mexican Sheartail hummingbird (Doricha eliza).

    Science.gov (United States)

    Licona-Vera, Yuyini; Ornelas, Juan Francisco

    2014-01-01

    The Mexican Sheartail (Doricha eliza), an endangered hummingbird, is endemic to Mexico where two populations have a disjunct distribution. One population is distributed along the northern tip of the Yucatan Peninsula whereas the other is mostly restricted to central Veracruz. Despite their disjunct distribution, previous work has failed to detect morphological or behavioral differences between these populations. Here we use variation in morphology, mtDNA and nuDNA sequences to determine the degree of morphological and molecular divergence between populations, their divergence time, and historical demography. We use species distribution modeling and niche divergence tests to infer the relative roles of vicariance and dispersal in driving divergence in the genus. Our Bayesian and maximum likelihood phylogenetic analyses revealed that Doricha eliza populations form a monophyletic clade and support their sister relationship with D. enicura. We found marked genetic differentiation, with reciprocal monophyly of haplotypes and highly restricted gene flow, supporting a history of isolation over the last 120,000 years. Genetic divergence between populations is consistent with the lack of overlap in environmental space and slight morphological differences between males. Our findings indicate that the divergence of the Veracruz and Yucatan populations is best explained by a combination of a short period of isolation exacerbated by subsequent divergence in climate conditions, and that rather than vicariance, the two isolated ranges of D. eliza are the product of recent colonization and divergence in isolation.

  4. Pollinator-mediated selection in a specialized hummingbird-Heliconia system in the Eastern Caribbean.

    Science.gov (United States)

    Temeles, E J; Rah, Y J; Andicoechea, J; Byanova, K L; Giller, G S J; Stolk, S B; Kress, W J

    2013-02-01

    Phenotypic matches between plants and their pollinators often are interpreted as examples of reciprocal selection and adaptation. For the two co-occurring plant species, Heliconia bihai and H. caribaea in the Eastern Caribbean, we evaluated for five populations over 2 years the strength and direction of natural selection on corolla length and number of bracts per inflorescence. These plant traits correspond closely to the bill lengths and body masses of their primary pollinators, female or male purple-throated carib hummingbirds (Eulampis jugularis). In H. bihai, directional selection for longer corollas was always significant with the exception of one population in 1 year, whereas selection on bract numbers was rare and found only in one population in 1 year. In contrast, significant directional selection for more bracts per inflorescence occurred in all three populations of the yellow morph and in two populations of the red morph of H. caribaea, whereas significant directional selection on corolla length occurred in only one population of the red morph and one population of the yellow morph. Selection for longer corollas in H. bihai may result from better mechanical fit, and hence pollination, by the long bills of female E. jugularis, their sole pollinator. In contrast, competition between males of E. jugularis for territories may drive selection for more bracts in H. caribaea. Competitive exclusion of female E. jugularis by territorial males also implicates pollinator competition as a possible ecological mechanism for trait diversification in these plants.

  5. Cognitive Ecology in Hummingbirds: The Role of Sexual Dimorphism and Its Anatomical Correlates on Memory

    Science.gov (United States)

    González-Gómez, Paulina L.; Madrid-Lopez, Natalia; Salazar, Juan E.; Suárez, Rodrigo; Razeto-Barry, Pablo; Mpodozis, Jorge; Bozinovic, Francisco; Vásquez, Rodrigo A.

    2014-01-01

    In scatter-hoarding species, several behavioral and neuroanatomical adaptations allow them to store and retrieve thousands of food items per year. Nectarivorous animals face a similar scenario having to remember quality, location and replenishment schedules of several nectar sources. In the green-backed firecrown hummingbird (Sephanoides sephanoides), males are territorial and have the ability to accurately keep track of nectar characteristics of their defended food sources. In contrast, females display an opportunistic strategy, performing rapid intrusions into males territories. In response, males behave aggressively during the non-reproductive season. In addition, females have higher energetic demands due to higher thermoregulatory costs and travel times. The natural scenario of this species led us to compared cognitive abilities and hippocampal size between males and females. Males were able to remember nectar location and renewal rates significantly better than females. However, the hippocampal formation was significantly larger in females than males. We discuss these findings in terms of sexually dimorphic use of spatial resources and variable patterns of brain dimorphisms in birds. PMID:24599049

  6. Genetic, ecological and morphological divergence between populations of the endangered Mexican Sheartail hummingbird (Doricha eliza.

    Directory of Open Access Journals (Sweden)

    Yuyini Licona-Vera

    Full Text Available The Mexican Sheartail (Doricha eliza, an endangered hummingbird, is endemic to Mexico where two populations have a disjunct distribution. One population is distributed along the northern tip of the Yucatan Peninsula whereas the other is mostly restricted to central Veracruz. Despite their disjunct distribution, previous work has failed to detect morphological or behavioral differences between these populations. Here we use variation in morphology, mtDNA and nuDNA sequences to determine the degree of morphological and molecular divergence between populations, their divergence time, and historical demography. We use species distribution modeling and niche divergence tests to infer the relative roles of vicariance and dispersal in driving divergence in the genus. Our Bayesian and maximum likelihood phylogenetic analyses revealed that Doricha eliza populations form a monophyletic clade and support their sister relationship with D. enicura. We found marked genetic differentiation, with reciprocal monophyly of haplotypes and highly restricted gene flow, supporting a history of isolation over the last 120,000 years. Genetic divergence between populations is consistent with the lack of overlap in environmental space and slight morphological differences between males. Our findings indicate that the divergence of the Veracruz and Yucatan populations is best explained by a combination of a short period of isolation exacerbated by subsequent divergence in climate conditions, and that rather than vicariance, the two isolated ranges of D. eliza are the product of recent colonization and divergence in isolation.

  7. Three-dimensional flow and lift characteristics of a hovering ruby-throated hummingbird.

    Science.gov (United States)

    Song, Jialei; Luo, Haoxiang; Hedrick, Tyson L

    2014-09-06

    A three-dimensional computational fluid dynamics simulation is performed for a ruby-throated hummingbird (Archilochus colubris) in hovering flight. Realistic wing kinematics are adopted in the numerical model by reconstructing the wing motion from high-speed imaging data of the bird. Lift history and the three-dimensional flow pattern around the wing in full stroke cycles are captured in the simulation. Significant asymmetry is observed for lift production within a stroke cycle. In particular, the downstroke generates about 2.5 times as much vertical force as the upstroke, a result that confirms the estimate based on the measurement of the circulation in a previous experimental study. Associated with lift production is the similar power imbalance between the two half strokes. Further analysis shows that in addition to the angle of attack, wing velocity and surface area, drag-based force and wing-wake interaction also contribute significantly to the lift asymmetry. Though the wing-wake interaction could be beneficial for lift enhancement, the isolated stroke simulation shows that this benefit is buried by other opposing effects, e.g. presence of downwash. The leading-edge vortex is stable during the downstroke but may shed during the upstroke. Finally, the full-body simulation result shows that the effects of wing-wing interaction and wing-body interaction are small.

  8. Geomorphological mapping of shallow landslides using UAVs

    Science.gov (United States)

    Fiorucci, Federica; Giordan, Daniele; Dutto, Furio; Rossi, Mauro; Guzzetti, Fausto

    2015-04-01

    The mapping of event shallow landslides is a critical activity, due to the large number of phenomena, mostly with small dimension, affecting extensive areas. This is commonly done through aerial photo-interpretation or through field surveys. Nowadays, landslide maps can be realized exploiting other methods/technologies: (i) airborne LiDARs, (ii) stereoscopic satellite images, and (iii) unmanned aerial vehicles (UAVs). In addition to the landslide maps, these methods/technologies allow the generation of updated Digital Terrain Models (DTM). In December 2013, in the Collazzone area (Umbria, Central Italy), an intense rainfall event triggered a large number of shallow landslides. To map the landslides occurred in the area, we exploited data and images obtained through (A) an airborne LiDAR survey, (B) a remote controlled optocopter (equipped with a Canon EOS M) survey, and (C) a stereoscopic satellite WorldView II MS. To evaluate the mapping accuracy of these methods, we select two landslides and we mapped them using a GPS RTK instrumentation. We consider the GPS survey as the benchmark being the most accurate system. The results of the comparison allow to highlight pros and cons of the methods/technologies used. LiDAR can be considered the most accurate system and in addition it allows the extraction and the classification of the digital surface models from the surveyed point cloud. Conversely, LiDAR requires additional time for the flight planning, and specific data analysis user capabilities. The analysis of the satellite WorldView II MS images facilitates the landslide mapping over large areas, but at the expenses of a minor resolution to detect the smaller landslides and their boundaries. UAVs can be considered the cheapest and fastest solution for the acquisition of high resolution ortho-photographs on limited areas, and the best solution for a multi-temporal analysis of specific landslide phenomena. Limitations are due to (i) the needs of optimal climatic

  9. Two-Step Camera Calibration Method Developed for Micro UAV'S

    Science.gov (United States)

    Gašparović, M.; Gajski, D.

    2016-06-01

    The development of unmanned aerial vehicles (UAVs) and continuous price reduction of unmanned systems attracted us to this research. Professional measuring systems are dozens of times more expensive and often heavier than "amateur", non-metric UAVs. For this reason, we tested the DJI Phantom 2 Vision Plus UAV. Phantom's smaller mass and velocity can develop less kinetic energy in relation to the professional measurement platforms, which makes it potentially less dangerous for use in populated areas. In this research, we wanted to investigate the ability of such non-metric UAV and find the procedures under which this kind of UAV may be used for the photogrammetric survey. It is important to emphasize that UAV is equipped with an ultra wide-angle camera with 14MP sensor. Calibration of such cameras is a complex process. In the research, a new two-step process is presented and developed, and the results are compared with standard one-step camera calibration procedure. Two-step process involves initially removed distortion on all images, and then uses these images in the phototriangulation with self-calibration. The paper presents statistical indicators which proved that the proposed two-step process is better and more accurate procedure for calibrating those types of cameras than standard one-step calibration. Also, we suggest two-step calibration process as the standard for ultra-wideangle cameras for unmanned aircraft.

  10. Camera Calibration Accuracy at Different Uav Flying Heights

    Science.gov (United States)

    Yusoff, A. R.; Ariff, M. F. M.; Idris, K. M.; Majid, Z.; Chong, A. K.

    2017-02-01

    Unmanned Aerial Vehicles (UAVs) can be used to acquire highly accurate data in deformation survey, whereby low-cost digital cameras are commonly used in the UAV mapping. Thus, camera calibration is considered important in obtaining high-accuracy UAV mapping using low-cost digital cameras. The main focus of this study was to calibrate the UAV camera at different camera distances and check the measurement accuracy. The scope of this study included camera calibration in the laboratory and on the field, and the UAV image mapping accuracy assessment used calibration parameters of different camera distances. The camera distances used for the image calibration acquisition and mapping accuracy assessment were 1.5 metres in the laboratory, and 15 and 25 metres on the field using a Sony NEX6 digital camera. A large calibration field and a portable calibration frame were used as the tools for the camera calibration and for checking the accuracy of the measurement at different camera distances. Bundle adjustment concept was applied in Australis software to perform the camera calibration and accuracy assessment. The results showed that the camera distance at 25 metres is the optimum object distance as this is the best accuracy obtained from the laboratory as well as outdoor mapping. In conclusion, the camera calibration at several camera distances should be applied to acquire better accuracy in mapping and the best camera parameter for the UAV image mapping should be selected for highly accurate mapping measurement.

  11. A Natural Interaction Interface for UAVs Using Intuitive Gesture Recognition

    Science.gov (United States)

    Chandarana, Meghan; Trujillo, Anna; Shimada, Kenji; Allen, Danette

    2016-01-01

    The popularity of unmanned aerial vehicles (UAVs) is increasing as technological advancements boost their favorability for a broad range of applications. One application is science data collection. In fields like Earth and atmospheric science, researchers are seeking to use UAVs to augment their current portfolio of platforms and increase their accessibility to geographic areas of interest. By increasing the number of data collection platforms UAVs will significantly improve system robustness and allow for more sophisticated studies. Scientists would like be able to deploy an available fleet of UAVs to fly a desired flight path and collect sensor data without needing to understand the complex low-level controls required to describe and coordinate such a mission. A natural interaction interface for a Ground Control System (GCS) using gesture recognition is developed to allow non-expert users (e.g., scientists) to define a complex flight path for a UAV using intuitive hand gesture inputs from the constructed gesture library. The GCS calculates the combined trajectory on-line, verifies the trajectory with the user, and sends it to the UAV controller to be flown.

  12. A mini-UAV VTOL Platform for Surveying Applications

    Directory of Open Access Journals (Sweden)

    Kuldeep Rawat

    2014-05-01

    Full Text Available In this paper we discuss implementation of a mini-Unmanned Aerial Vehicle (UAV vertical take-off and landing (VTOL platform for surveying activities related to highway construction. Recent advances in sensor and communication technologies have allowed scaling sizes of unmanned aerial platforms, and explore them for tasks that are economical and safe over populated or inhabited areas. In highway construction the capability of mini-UAVs to survey in hostile and/or hardly accessible areas can greatly reduce human risks. The project focused on developing a cost effective, remotely controlled, fuel powered mini-UAV VTOL (helicopter platform with certain payload capacity and configuration and demonstrated its use in surveying and monitoring activities required for highway planning and construction. With an on-board flight recorder global positioning system (GPS device, memory storage card, telemetry, inertial navigation sensors, and a video camera the mini-UAV can record flying coordinates and relay live video images to a remote ground receiver and surveyor. After all necessary integration and flight tests were done the mini-UAV helicopter was tested to operate and relay video from the areas where construction was underway. The mini-UAV can provide a platform for a range of sensors and instruments that directly support the operational requirements of transportation sector.

  13. Rancang Bangun Prototype Unmanned Aerial Vehicle (UAV dengan Tiga Rotor

    Directory of Open Access Journals (Sweden)

    Darmawan Rasyid Hadi Saputra

    2013-03-01

    Full Text Available Unmanned Aerial Vehicle atau yang biasa dikenal dengan istilah UAV  merupakan sebuah sistem penerbangan/ pesawat tanpa pilot yang berada di dalam pesawat tersebut. UAV dapat dikendalikan dengan menggunakan remote dari jarak jauh, diprogram dengan perintah tertentu, atau bahkan dengan sistem pengendalian otomatis yang lebih kompleks. Aplikasi dari teknologi UAV pun beragam mulai dari tugas militer hingga pengamatan udara. Dalam penelitian ini, sebuah UAV akan dikembangkan dengan tiga buah rotor dan satu buah motor servo di bagian belakang UAV. Perancangan model menggunakan software CATIA dengan batasan dimensi (panjang × lebar maksimum 75 × 75 cm dan massa < 2 kg. Analisis struktur rangka dilakukan untuk menguji kekuatan rangka ketika terbang dan membawa beban, dengan menggunakan metode elemen hingga dan kriteria kegagalan Von-Misses. Dalam proses pengerjaan, rancangan dari CATIA dan analisis yang telah dilakukan dalam perancangan tersebut akan digunakan. Hasil yang didapat berupa UAV yang memiliki struktur rangka dengan defleksi maksimum 3,67 mm pada rangka tengah yang berbahan acrylic. Dalam pengujian di lapangan, UAV dapat melakukan gerak roll, pitch, dan yaw yang dikendalikan melalui remote control. Waktu operasi maksimum yang dapat dilakukan adalah selama 7 menit 43 detik.

  14. Experiences with Light Weight Fixed Wing Aerial Mapping UAVs

    Directory of Open Access Journals (Sweden)

    W. Mayr

    2014-11-01

    Full Text Available UAVs seem to be the next "cloud" like topic, not only in geomatics. Unmanned Airborne Vehicles are not a wonder-tool, but a complementary approach to resolve some tasks more efficiently than before or at all. Since 2006 we commercially apply fixed wing, light weight UAVs for aerial mapping purposes. In this paper we like to share our experiences with UAVs of less than 5 kg and illuminate some limitations as well as potentials. Whereas multicopters seem to be in use everywhere, fixed wing UAVs more frequently seem to be applied in specific and geospatially oriented applications. Having processed several hundred UAV aerial mapping projects there forms a stable picture of this technology. Our impressions on durability, handling, and reliability of fixed wing UAVs get presented. We report on our day-to-day experiences and point to often simple hurdles to overcome. Various cameras were flown, different approaches of handling their geometries with different software packages were undertaken. Remarks to achieved geometric accuracies as well as the consequences of using dual frequency GPS instead of simple yet great single frequency GPS are discussed. All of this packed into the subsequent paper.

  15. UAV based distributed ATR under realistic simulated environmental effects

    Science.gov (United States)

    Chen, Xiaohan; Gong, Shanshan; Schmid, Natalia A.; Valenti, Matthew C.

    2007-04-01

    Over the past several years, the military has grown increasingly reliant upon the use of unattended aerial vehicles (UAVs) for surveillance missions. There is an increasing trend towards fielding swarms of UAVs operating as large-scale sensor networks in the air. Such systems tend to be used primarily for the purpose of acquiring sensory data with the goal of automatic detection, identification, and tracking objects of interest. These trends have been paralleled by advances in both distributed detection, image/signal processing and data fusion techniques. Furthermore, swarmed UAV systems must operate under severe constraints on environmental conditions and sensor limitations. In this work, we investigate the effects of environmental conditions on target detection and recognition performance in a UAV network. We assume that each UAV is equipped with an optical camera, and use a realistic computer simulation to generate synthetic images. The detection algorithm relies on Haar-based features while the automatic target recognition (ATR) algorithm relies on Bessel K features. The performance of both algorithms is evaluated using simulated images that closely mimic data acquired in a UAV network under realistic environmental conditions. We design several fusion techniques and analyze both the case of a single observation and the case of multiple observations of the same target.

  16. Autonomous Chemical Vapour Detection by Micro UAV

    Directory of Open Access Journals (Sweden)

    Kent Rosser

    2015-12-01

    Full Text Available The ability to remotely detect and map chemical vapour clouds in open air environments is a topic of significant interest to both defence and civilian communities. In this study, we integrate a prototype miniature colorimetric chemical sensor developed for methyl salicylate (MeS, as a model chemical vapour, into a micro unmanned aerial vehicle (UAV, and perform flights through a raised MeS vapour cloud. Our results show that that the system is capable of detecting MeS vapours at low ppm concentration in real-time flight and rapidly sending this information to users by on-board telemetry. Further, the results also indicate that the sensor is capable of distinguishing “clean” air from “dirty”, multiple times per flight, allowing us to look towards autonomous cloud mapping and source localization applications. Further development will focus on a broader range of integrated sensors, increased autonomy of detection and improved engineering of the system.

  17. Triangle and GA Methods for UAVs Jamming

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2014-01-01

    Full Text Available We focus on how to jam UAVs network efficiently. The system model is described and the problem is formulated. Based on two properties and a theorem which helps to decide good location for a jammer, we present the Triangle method to find good locations for jammers. The Triangle method is easy to understand and has overall computational complexity of ON2. We also present a genetic algorithm- (GA- based jamming method, which has computational complex of OLMN2. New chromosome, mutation, and crossover operations are redefined for the GA method. The simulation shows that Triangle and GA methods perform better than Random method. If the ratio of jammers’ number to UAVs’ number is low (lower than 1/5 in this paper, GA method does better than Triangle method. Otherwise, Triangle method performs better.

  18. Development of Open source-based automatic shooting and processing UAV imagery for Orthoimage Using Smart Camera UAV

    Science.gov (United States)

    Park, J. W.; Jeong, H. H.; Kim, J. S.; Choi, C. U.

    2016-06-01

    Recently, aerial photography with unmanned aerial vehicle (UAV) system uses UAV and remote controls through connections of ground control system using bandwidth of about 430 MHz radio Frequency (RF) modem. However, as mentioned earlier, existing method of using RF modem has limitations in long distance communication. The Smart Camera equipments's LTE (long-term evolution), Bluetooth, and Wi-Fi to implement UAV that uses developed UAV communication module system carried out the close aerial photogrammetry with the automatic shooting. Automatic shooting system is an image capturing device for the drones in the area's that needs image capturing and software for loading a smart camera and managing it. This system is composed of automatic shooting using the sensor of smart camera and shooting catalog management which manages filmed images and information. Processing UAV imagery module used Open Drone Map. This study examined the feasibility of using the Smart Camera as the payload for a photogrammetric UAV system. The open soure tools used for generating Android, OpenCV (Open Computer Vision), RTKLIB, Open Drone Map.

  19. Development of Open source-based automatic shooting and processing UAV imagery for Orthoimage Using Smart Camera UAV

    Directory of Open Access Journals (Sweden)

    J. W. Park

    2016-06-01

    Full Text Available Recently, aerial photography with unmanned aerial vehicle (UAV system uses UAV and remote controls through connections of ground control system using bandwidth of about 430 MHz radio Frequency (RF modem. However, as mentioned earlier, existing method of using RF modem has limitations in long distance communication. The Smart Camera equipments’s LTE (long-term evolution, Bluetooth, and Wi-Fi to implement UAV that uses developed UAV communication module system carried out the close aerial photogrammetry with the automatic shooting. Automatic shooting system is an image capturing device for the drones in the area’s that needs image capturing and software for loading a smart camera and managing it. This system is composed of automatic shooting using the sensor of smart camera and shooting catalog management which manages filmed images and information. Processing UAV imagery module used Open Drone Map. This study examined the feasibility of using the Smart Camera as the payload for a photogrammetric UAV system. The open soure tools used for generating Android, OpenCV (Open Computer Vision, RTKLIB, Open Drone Map.

  20. UAV formation control design with obstacle avoidance in dynamic three-dimensional environment.

    Science.gov (United States)

    Chang, Kai; Xia, Yuanqing; Huang, Kaoli

    2016-01-01

    This paper considers the artificial potential field method combined with rotational vectors for a general problem of multi-unmanned aerial vehicle (UAV) systems tracking a moving target in dynamic three-dimensional environment. An attractive potential field is generated between the leader and the target. It drives the leader to track the target based on the relative position of them. The other UAVs in the formation are controlled to follow the leader by the attractive control force. The repulsive force affects among the UAVs to avoid collisions and distribute the UAVs evenly on the spherical surface whose center is the leader-UAV. Specific orders or positions of the UAVs are not required. The trajectories of avoidance obstacle can be obtained through two kinds of potential field with rotation vectors. Every UAV can choose the optimal trajectory to avoid the obstacle and reconfigure the formation after passing the obstacle. Simulations study on UAV are presented to demonstrate the effectiveness of proposed method.

  1. 微型四轴飞行器的设计与实现%Design and implementation of mini quad-rotors aircraft

    Institute of Scientific and Technical Information of China (English)

    薛鹏; 任鹏飞; 曹学儒; 马壮

    2016-01-01

    The quad-rotor mini rotorcraft is an under actuated system,which is powered by adjusting the speed of the motors. In order to discuss the problem of quad-rotor aircraft control,the preliminary design of the control system was proposed. The hardware of flight control system was designed based on single chip microcontroller STM32 and sensor MPU6050. The key points include driven cir-cuit,sensors and communication module. Based on PID control scheme,the software was fulfilled. As its core part,quaternion num-bers and Kalman filtering were adopted to obtain exact values of the attitude angles. Simulation and indoor tests results shown that the designed hardware system is reliable and can meet requirements. Some meaningful experiences to the design of quad-rotor aircraft are introduced.%四轴飞行器是通过调节电机转速来控制运动姿态的典型欠驱动系统,为研究飞行器的姿态控制问题,对飞行控制系统进行了初步设计。硬件部分以STM32单片机为主控芯片,采用MPU6050陀螺仪传感器完成飞行控制系统的选型设计,重点讨论了驱动电路、传感器和通信模块的选型设计。软件部分以PID控制为基础,重点介绍了姿态角检测过程中的四元数变换和卡尔曼滤波环节,这两个步骤保障了所得姿态角的准确性。仿真分析和室内测试显示,该硬件设计性能可靠,其姿态角控制达到了预期效果,对四轴飞行器的设计有借鉴意义。

  2. 基于anti-windup技术的四旋翼模糊PID控制%Fuzzy PID Control of Quad-Rotor Aircraft Based on Anti-windup Technology

    Institute of Scientific and Technical Information of China (English)

    耿玉豪; 肖文生; 崔俊国; 王鸿雁

    2016-01-01

    When quad-rotor aircraft is trapped in the great disturbance of wind, windup phenomenon may appear for simple PID controller, under the combined action of integration element and saturation limit element. Thus may lead to deterioration of system’s dynamic responses, and big overshoot or imbalance of quad-rotor. A dynamics simulation model is established for the quad-rotor aircraft, and the causes of windup phenomenon are analyzed. An anti-windup PID controller with fuzzy variable parameters is designed to alleviate the windup phenomenon. Contrastive analysis is made to the controller with the existing fuzzy PID controller and the anti-windup PID controller with constant parameters. The results of simulation indicate that, the fuzzy PID controller based on anti-windup technology can effectively restrain the windup phenomenon, and speed up the attitude adjustment process of quad-rotor.%四旋翼飞行器在受到风力等大扰动的情况下,单纯的PID控制受到积分环节和饱和限幅环节的共同作用,容易产生windup现象,系统动态响应变差,造成飞行器大超调甚至失调。通过建立四旋翼飞行器的动力学仿真模型,分析了windup现象产生的原因,设计了参数模糊可变的anti-windup PID控制器,用于缓解windup现象。对比分析了该控制器与现有的模糊PID控制器、参数为定值的anti-windup PID控制器的性能,仿真结果表明,基于anti-windup技术的模糊PID控制器,能够更加有效地抑制windup现象,加快飞行器的姿态调节过程。

  3. Multiple Event Localization in a Sparse Acoustic Sensor Network Using UAVs as Data Mules

    Science.gov (United States)

    2012-12-01

    a Microhard radio to forward the ToAs to the mule-UAV. Two Procerus Unicorn UAVs were used with different payloads. The imaging- UAV was equipped...particularly useful when the regions overlap. We present results from a field test in Section IV and conclude in Section V. II. MULTIPLE EVENT LOCALIZATION...Path taken by mule-UAV during tests . The desired path was sent to autopilot via square waypoints. The sensors and communication regions are

  4. Collaborative mission planning for UAV cluster to optimize relay distance

    Science.gov (United States)

    Tanil, Cagatay; Warty, Chirag; Obiedat, Esam

    Unmanned Aerial Vehicles (UAVs) coordinated path planning and intercommunication for visual exploration of a geographical region has recently become crucial. Multiple UAVs cover larger area than a single UAV and eliminate blind spots. To improve the surveillance, survivability and quality of the communication, we propose two algorithms for the route planning of UAV cluster operated in obstacle rich environment: (i) Multiple Population Genetic Algorithm (MPGA) (ii) Relay Selection Criteria (RSC). The main objective of MPGA is to minimize the total mission time while maintaining an optimal distance for communication between the neighboring nodes. MPGA utilizes evolutionary speciation techniques with a novel Feasible Population Creation Method (FPCM) and enhanced Inter-species Crossover Mechanism (ISCM) to obtain diversified routes in remarkably short time. In obtaining collision-free optimum paths, UAVs are subjected to constraints such as limited communication range, maximum maneuverability and fuel capacity. In addition to the path planning, RSC is developed for selection of UAVs relay nodes that is based on the location of the relay relative to source and destination. It is crucial since the Bit Error Rate (BER) performance of the link significantly depends on the location of the selected relay. In this paper, path planning and relay allocation algorithms are combined to have a seamless high quality monitoring of the region and to provide superior Quality of Service (QoS) for audio-video applications. Also, simulations in different operation zones with a cluster of up to six UAVs are performed to verify the feasibility of the proposed algorithms both in optimality and computation time.

  5. UAV Research, Operations, and Flight Test at the NASA Dryden Flight Research Center

    Science.gov (United States)

    Cosentino, Gary B.

    2009-01-01

    This slide presentation reviews some of the projects that have extended NASA Dryden's capabilities in designing, testing, and using Unmanned Aerial Vehicles (UAV's). Some of the UAV's have been for Science and experimental applications, some have been for flight research and demonstration purposes, and some have been small UAV's for other customers.

  6. Pollination efficiency and effectiveness or bumble bees and hummingbirds visiting Delphinium nelsonii

    Directory of Open Access Journals (Sweden)

    Waser, Nicholas M.

    1990-12-01

    Full Text Available Delphinium nelsonii Greene is a spring-flowering perennial of the Rocky Mountains of North America. Its blue flowers conform to a classical «bee pollination syndrome», but in western Colorado they are visited by hummingbirds (mostly in the first half of the flowering season as well as bumble bee queens (mostly in the second half of the season. Experiments with potted plants showed that a bee deposits about 10 times as much pollen while visiting a flower as does a bird, and causes about la times as many seeds to be set. In contrast, bees and birds appear similar in the «quality» of pollen they deliver, e. g., in its outcrossing distance. At the level of entire pollinator populations, hummingbird visitation rates may be over 10 times as great as those or bumble bees, in part because birds visit flowers more quickly. Thus the two visitor classes should deliver similar pollen quantities overall, which is confirmed by similar pollen loads of flowers early and late in the season, and should contribute about equally to seed set, which is confirmed by several experiments and observations. Exact relative contributions probably depend on pollinator population sizes, which in the case of hummingbirds appear to have varied 2.5 fold across 14 years. The similar contributions or birds and bees lo seed set shows that individual pollination efficiency must be distinguished from population-level effectiveness. and that the «pollination syndrome» of a flower may not indicate present-day effectiveness of its visitors.

    [ca] Delphinium nelsonii Greene és una planta perenne de floració primaveral que creix a les Muntanyes Rocoses de Nordamèrica. Les seves flors blaves s'acorden a la clàssica (síndrome de pol-linització per abellots», però, a l'oest de Colorado, són visitades per colibrís (durant la primera meitat del període de floració així com per reines d'abellots (principalment durant la segona meitat del període. Els

  7. AirGuardian - UAV Hardware and Software System for Small Size UAVs

    Directory of Open Access Journals (Sweden)

    Dániel Stojcsics

    2012-11-01

    Full Text Available AirGuardian is a complex of an Unmanned Aerial Vehicle and ground station UAV hardware and software systems which has been developed at Obuda University. The hardware and software of the autopilot (AERObot, the antenna tracker station and the ground control station were simultaneously created resulting in the optimal cooperation of the modules. The aim of the research on AERObot ‐ the special autopilot ‐ was to create a generic autopilot which is capable of controlling different designs, weights and structures of airframes without any complex mathematical model recalculation.

  8. Flight muscle enzymes and metabolic flux rates during hovering flight of the nectar bat, Glossophaga soricina: further evidence of convergence with hummingbirds.

    Science.gov (United States)

    Suarez, R K; Welch, K C; Hanna, S K; Herrera M, L G

    2009-06-01

    Given their high metabolic rates, nectarivorous diet, and ability to directly fuel their energetically-expensive flight using recently-ingested sugar, we tested the hypothesis that Pallas long tongued nectar bats (Glossophaga soricina) possess flight muscles similar to those of hummingbirds with respect to enzymatic flux capacities in bioenergetic pathways. In addition, we compared these biochemical capacities with flux rates achieved in vivo during hovering flight. Rates of oxygen consumption (V(O(2))) were measured during hover-feeding and used to estimate rates of ATP turnover, glucose and long-chain fatty acid oxidation per unit mass of flight muscle. Enzyme V(max) values at key steps in glucose and fatty acid oxidation obtained in vitro from pectoralis muscle samples exceed those found in the locomotory muscles of other species of small mammals and resemble data obtained from hummingbird flight muscles. The ability of nectar bats and hummingbirds to hover in fed and fasted states, fueled almost exclusively by carbohydrate or fat, respectively, allowed the estimation of fractional velocities (v/V(max)) at both the hexokinase and carnitine palmitoyltransferase-2 steps in glucose and fatty acid oxidation, respectively. The results further support the hypothesis of convergent evolution in biochemical and physiological traits in nectar bats and hummingbirds.

  9. Design and Analysis of Delta Wing Tilt Rotor UAV

    Directory of Open Access Journals (Sweden)

    S.Ravikanth

    2015-07-01

    Full Text Available A tilt rotor is an aircraft of a special kind, which possesses the characteristics of a helicopter and a fixed-wing airplane. However, there are a great number of important technical problems waiting for settlements. Of them, the flight control system might be a critical one. A tiltrotor aircraft comprising a pair of contra-rotating co-axial tiltable rotors on the longitudinal center line of the aircraft. The rotors may be tiltable sequentially and independently. They may be moveable between a lift position and a flight position in front of or behind the fuselage.In this paper we present a project aimed for the designing of a small scale Unmanned Aerial Vehicle (UAV with Tiltrotor configuration (that uses two rotating rotors. he current paper describes the adopted design methodology, the mathematical and computational models created to represent the UAV, the physical components that constitute the UAV, and the results obtained so far. An unmanned aerial vehicle (UAV, also known as a remotely piloted aircraft (RPA or unmanned aircraft, is a machine which functions either by the remote control of a navigator or pilot or autonomously. A UAV is defined as a powered, aerial vehicle that does not carry a human operator, uses aerodynamic forces to provide vehicle lift, can fly autonomously or be piloted remotely, can be expendable or recoverable, and can carry payload.India‘s requirement of these unmanned aerial vehicles (UAV has become prior need for fighting in the northeast, against threat of terrorism, tension along the Pakistan border and its emerging role as a regional naval power and subsequent need for surveillance. The military wants to acquire at least 1,500 unmanned systems in the next 3-4 years, ranging from man-portable drones to high-altitude, long-endurance (HALE vehicles.Indian military is using Israeli-built UAVs such as the Heron, Searcher Mk II and Harop from Israel Aerospace Industries (IAI. Till date India has mostly deployed

  10. Reproducibility of UAV-based photogrammetric surface models

    Science.gov (United States)

    Anders, Niels; Smith, Mike; Cammeraat, Erik; Keesstra, Saskia

    2016-04-01

    Soil erosion, rapid geomorphological change and vegetation degradation are major threats to the human and natural environment in many regions. Unmanned Aerial Vehicles (UAVs) and Structure-from-Motion (SfM) photogrammetry are invaluable tools for the collection of highly detailed aerial imagery and subsequent low cost production of 3D landscapes for an assessment of landscape change. Despite the widespread use of UAVs for image acquisition in monitoring applications, the reproducibility of UAV data products has not been explored in detail. This paper investigates this reproducibility by comparing the surface models and orthophotos derived from different UAV flights that vary in flight direction and altitude. The study area is located near Lorca, Murcia, SE Spain, which is a semi-arid medium-relief locale. The area is comprised of terraced agricultural fields that have been abandoned for about 40 years and have suffered subsequent damage through piping and gully erosion. In this work we focused upon variation in cell size, vertical and horizontal accuracy, and horizontal positioning of recognizable landscape features. The results suggest that flight altitude has a significant impact on reconstructed point density and related cell size, whilst flight direction affects the spatial distribution of vertical accuracy. The horizontal positioning of landscape features is relatively consistent between the different flights. We conclude that UAV data products are suitable for monitoring campaigns for land cover purposes or geomorphological mapping, but special care is required when used for monitoring changes in elevation.

  11. Application of agricultural subsidy inspection using UAV image

    Science.gov (United States)

    Park, Jin-Ki; Das, Amrita; Park, Jong-Hwa

    2016-10-01

    The most important parameters, should be considered during application of remote sensing techniques in agricultural sector, is to acquire image data in appropriate moment in accordance with the growth of the crop. Unmanned Aerial Vehicles (UAVs) have several advantages over conventional remote sensing techniques. They can acquire high-resolution images quickly and repeatedly with a comparatively lower flight altitude i.e. 80 400m nullifying the effect of extreme weather and cloud. This study discussed the use of low cost-effective UAV based remote sensing application in inspection of agricultural subsidy. The study area includes 129.1km2 of Miwon town. UAV images acquired 41 times from July 17 to August 10, 2015 for 7 days. The UAV images identify a significant amount of incorrect applications for agricultural subsidy, almost 29.6% (559 of 1,889). Surveying with UAV for agricultural payment instead of field stuff can reduce the time as much as 76.7 % and increase the effectiveness of inspection methods.

  12. A novel fast target tracking method for UAV aerial image

    Directory of Open Access Journals (Sweden)

    Jianfang Liu

    2017-06-01

    Full Text Available Unmanned aerial vehicles (UAV are able to achieve autonomous flight without drivers, and UAV has been a key tool to extract space data. Therefore, how to detect the trajectories of targets from UAV aerial image sequences is of great importance. Because local features are suitable to detect target tracking, we exploit scaleinvariant feature transform (SIFT features to describe the interesting keypoints of targets. The main innovation of this paper is to utilize Multiple hypothesis tracking (MHT algorithm to track an object (target in a series of image sequences. Particularly, we develop a MHT framework based on a multidimensional assignment formulation and a sliding time window policy. To obtain target tracking from UAV aerial image sequences, three steps should be done, that is, 1 Breaking each track set into tracklet at a specific time, 2 Estimating the association cost of each track set, 3 Merging trajectory fragments to a longer one iteratively. Finally, we collect several UAV aerial image sequences with different target density to construct a dataset, and experimental results demonstrate the effectiveness of the proposed algorithm.

  13. UAV field demonstration of social media enabled tactical data link

    Science.gov (United States)

    Olson, Christopher C.; Xu, Da; Martin, Sean R.; Castelli, Jonathan C.; Newman, Andrew J.

    2015-05-01

    This paper addresses the problem of enabling Command and Control (C2) and data exfiltration functions for missions using small, unmanned, airborne surveillance and reconnaissance platforms. The authors demonstrated the feasibility of using existing commercial wireless networks as the data transmission infrastructure to support Unmanned Aerial Vehicle (UAV) autonomy functions such as transmission of commands, imagery, metadata, and multi-vehicle coordination messages. The authors developed and integrated a C2 Android application for ground users with a common smart phone, a C2 and data exfiltration Android application deployed on-board the UAVs, and a web server with database to disseminate the collected data to distributed users using standard web browsers. The authors performed a mission-relevant field test and demonstration in which operators commanded a UAV from an Android device to search and loiter; and remote users viewed imagery, video, and metadata via web server to identify and track a vehicle on the ground. Social media served as the tactical data link for all command messages, images, videos, and metadata during the field demonstration. Imagery, video, and metadata were transmitted from the UAV to the web server via multiple Twitter, Flickr, Facebook, YouTube, and similar media accounts. The web server reassembled images and video with corresponding metadata for distributed users. The UAV autopilot communicated with the on-board Android device via on-board Bluetooth network.

  14. 'Fly Like This': Natural Language Interface for UAV Mission Planning

    Science.gov (United States)

    Chandarana, Meghan; Meszaros, Erica L.; Trujillo, Anna; Allen, B. Danette

    2017-01-01

    With the increasing presence of unmanned aerial vehicles (UAVs) in everyday environments, the user base of these powerful and potentially intelligent machines is expanding beyond exclusively highly trained vehicle operators to include non-expert system users. Scientists seeking to augment costly and often inflexible methods of data collection historically used are turning towards lower cost and reconfigurable UAVs. These new users require more intuitive and natural methods for UAV mission planning. This paper explores two natural language interfaces - gesture and speech - for UAV flight path generation through individual user studies. Subjects who participated in the user studies also used a mouse-based interface for a baseline comparison. Each interface allowed the user to build flight paths from a library of twelve individual trajectory segments. Individual user studies evaluated performance, efficacy, and ease-of-use of each interface using background surveys, subjective questionnaires, and observations on time and correctness. Analysis indicates that natural language interfaces are promising alternatives to traditional interfaces. The user study data collected on the efficacy and potential of each interface will be used to inform future intuitive UAV interface design for non-expert users.

  15. A novel fast target tracking method for UAV aerial image

    Science.gov (United States)

    Jianfang, Liu; Hao, Zheng; Jingli, Gao

    2017-06-01

    Unmanned aerial vehicles (UAV) are able to achieve autonomous flight without drivers, and UAV has been a key tool to extract space data. Therefore, how to detect the trajectories of targets from UAV aerial image sequences is of great importance. Because local features are suitable to detect target tracking, we exploit scaleinvariant feature transform (SIFT) features to describe the interesting keypoints of targets. The main innovation of this paper is to utilize Multiple hypothesis tracking (MHT) algorithm to track an object (target) in a series of image sequences. Particularly, we develop a MHT framework based on a multidimensional assignment formulation and a sliding time window policy. To obtain target tracking from UAV aerial image sequences, three steps should be done, that is, 1) Breaking each track set into tracklet at a specific time, 2) Estimating the association cost of each track set, 3) Merging trajectory fragments to a longer one iteratively. Finally, we collect several UAV aerial image sequences with different target density to construct a dataset, and experimental results demonstrate the effectiveness of the proposed algorithm.

  16. Sense and avoid technology for Global Hawk and Predator UAVs

    Science.gov (United States)

    McCalmont, John F.; Utt, James; Deschenes, Michael; Taylor, Michael J.

    2005-05-01

    The Sensors Directorate at the Air Force Research Laboratory (AFRL) along with Defense Research Associates, Inc. (DRA) conducted a flight demonstration of technology that could potentially satisfy the Federal Aviation Administration's (FAA) requirement for Unmanned Aerial Vehicles (UAVs) to sense and avoid local air traffic sufficient to provide an "...equivalent level of safety, comparable to see-and-avoid requirements for manned aircraft". This FAA requirement must be satisfied for autonomous UAV operation within the national airspace. The real-time on-board system passively detects approaching aircraft, both cooperative and non-cooperative, using imaging sensors operating in the visible/near infrared band and a passive moving target indicator algorithm. Detection range requirements for RQ-4 and MQ-9 UAVs were determined based on analysis of flight geometries, avoidance maneuver timelines, system latencies and human pilot performance. Flight data and UAV operating parameters were provided by the system program offices, prime contractors, and flight-test personnel. Flight demonstrations were conducted using a surrogate UAV (Aero Commander) and an intruder aircraft (Beech Bonanza). The system demonstrated target detection ranges out to 3 nautical miles in nose-to-nose scenarios and marginal visual meteorological conditions. (VMC) This paper will describe the sense and avoid requirements definition process and the system concept (sensors, algorithms, processor, and flight rest results) that has demonstrated the potential to satisfy the FAA sense and avoid requirements.

  17. Potential Autonomous Selfing in Gesneria citrina (Gesneriaceae), a Specialized Hummingbird Pollinated Species with Variable Expression of Herkogamy

    Institute of Scientific and Technical Information of China (English)

    Xin-Sheng Chen; Silvana Martén-Rodriguez; Qing-Jun Li; Charles B.Fenster

    2009-01-01

    Species with mixed mating systems often demonstrate vadable expression of breeding system characteristics and thus represent the opportunity to understand the factors and mechanisms that promote both outcrossed and selfed seed production. Here, we investigate variation In levels of herkogamy (variation in stigma-anther separation distance) In a Puerto Rican population of hummingbird pollinated Gesneria citrina Urban. There is significant variation in herkogamy levels among individuals of this species and stigma-anther separation is negatively associated with the ability to set fruits and seeds in the absence of pollinators. The variation in levels of herkogamy may represent a mechanism to ensure the production of some self-fertilized progeny in the absence of hummingbird pollinators. We also describe a novel breeding system in G. citrina, where stamens elongate over time to reach stigma height, but stamen elongation is accelerated by pollination. These results suggest that once the flowers are pollinated, stamen elongation may favor increased pollen removal and siring success, while the reduction in stigma-anther distance no longer imposes the risk of interference between male and female functions. We discuss our findings of breeding system variation in the context of pollination system evolution in an island setting (Antillean islands).

  18. Potential autonomous selfing in Gesneria citrina (Gesneriaceae), a specialized hummingbird pollinated species with variable expression of herkogamy.

    Science.gov (United States)

    Chen, Xin-Sheng; Martén-Rodríguez, Silvana; Li, Qing-Jun; Fenster, Charles B

    2009-10-01

    Species with mixed mating systems often demonstrate variable expression of breeding system characteristics and thus represent the opportunity to understand the factors and mechanisms that promote both outcrossed and selfed seed production. Here, we investigate variation in levels of herkogamy (variation in stigma-anther separation distance) in a Puerto Rican population of hummingbird pollinated Gesneria citrina Urban. There is significant variation in herkogamy levels among individuals of this species and stigma-anther separation is negatively associated with the ability to set fruits and seeds in the absence of pollinators. The variation in levels of herkogamy may represent a mechanism to ensure the production of some self-fertilized progeny in the absence of hummingbird pollinators. We also describe a novel breeding system in G. citrina, where stamens elongate over time to reach stigma height, but stamen elongation is accelerated by pollination. These results suggest that once the flowers are pollinated, stamen elongation may favor increased pollen removal and siring success, while the reduction in stigma-anther distance no longer imposes the risk of interference between male and female functions. We discuss our findings of breeding system variation in the context of pollination system evolution in an island setting (Antillean islands).

  19. Effects of indiscriminate foraging by tropical hummingbirds on pollination and plant reproductive success: experiments with two tropical treelets (Rubiaceae).

    Science.gov (United States)

    Feinsinger, Peter; Busby, William H; Tiebout, Hary M

    1988-08-01

    In cloud forest at Monteverde, Costa Rica, two common treelets (Palicourea lasiorrachis and Cephaelis elata, both Rubiaceae) depend simultaneously on one hummingbird population (Lampornis calolaema) for pollination. Both species are distylous and self-incompatible. In laboratory experiments, we examined possible effects of indiscriminate foraging by hummingbirds among flowers of both species, as observed in the field, on pollination of Palicourea. In each of 35 trials, captive L. calolaema probed 2 flowers from pin plants of Palicourea followed by 20 thrum flowers of the same species, with either 0, 2, or 10 Cephaelis flowers intervening. We assessed pollen transfer by staining and counting pin pollen tubes growing in thrum styles; counts of 0, 1, or ≥2 pollen tubes relate directly to seed output (0, 1, or 2 seeds per fruit, respectively). Intervening Cephaelis flowers sharply reduced pollen receipt by thrum flowers of Palicourea and reduced some aspects of pollen dispersal from pins as well, thereby curtailing maternal and paternal reproductive potential of Palicourea. Such effects of interspecific pollen loss on reproductive output may lead to strong competition among some, though not all, combinations of plant species pollinated by L. calolaema or of other plant combinations that share animal pollinators.

  20. Multiyear study of multivariate linear and nonlinear phenotypic selection on floral traits of hummingbird-pollinated Silene virginica.

    Science.gov (United States)

    Reynolds, Richard J; Dudash, Michele R; Fenster, Charles B

    2010-02-01

    Pollination syndromes suggest that convergent evolution of floral traits and trait combinations reflects similar selection pressures. Accordingly, a pattern of selection on floral traits is expected to be consistent with increasing the attraction and pollen transfer of the important pollinator. We measured individual variation in six floral traits and yearly and lifetime total plant seed and fruit production of 758 plants across nine years of study in natural populations of Ruby-Throated Hummingbird-pollinated Silene virginica. The type, strength, and direction of selection gradients were observed by year, and for two cohorts selection was estimated through lifetime maternal fitness. Positive directional selection was detected on floral display height in all years of study and stigma exsertion in all years but one. Significant quadratic and correlational selection gradients were rare. However, a canonical analysis of the gamma matrix indicated nonlinear selection was common; if significant curvature was detected it was convex with one exception. Our analyses demonstrated selection favored trait combinations and the integration of floral features of attraction and pollen transfer efficiency that were consistent with the hummingbird pollination syndrome.

  1. An UAV scheduling and planning method for post-disaster survey

    Science.gov (United States)

    Li, G. Q.; Zhou, X. G.; Yin, J.; Xiao, Q. Y.

    2014-11-01

    Annually, the extreme climate and special geological environments lead to frequent natural disasters, e.g., earthquakes, floods, etc. The disasters often bring serious casualties and enormous economic losses. Post-disaster surveying is very important for disaster relief and assessment. As the Unmanned Aerial Vehicle (UAV) remote sensing with the advantage of high efficiency, high precision, high flexibility, and low cost, it is widely used in emergency surveying in recent years. As the UAVs used in emergency surveying cannot stop and wait for the happening of the disaster, when the disaster happens the UAVs usually are working at everywhere. In order to improve the emergency surveying efficiency, it is needed to track the UAVs and assign the emergency surveying task for each selected UAV. Therefore, a UAV tracking and scheduling method for post-disaster survey is presented in this paper. In this method, Global Positioning System (GPS), and GSM network are used to track the UAVs; an emergency tracking UAV information database is built in advance by registration, the database at least includes the following information, e.g., the ID of the UAVs, the communication number of the UAVs; when catastrophe happens, the real time location of all UAVs in the database will be gotten using emergency tracking method at first, then the traffic cost time for all UAVs to the disaster region will be calculated based on the UAVs' the real time location and the road network using the nearest services analysis algorithm; the disaster region is subdivided to several emergency surveying regions based on DEM, area, and the population distribution map; the emergency surveying regions are assigned to the appropriated UAV according to shortest cost time rule. The UAVs tracking and scheduling prototype is implemented using SQLServer2008, ArcEnginge 10.1 SDK, Visual Studio 2010 C#, Android, SMS Modem, and Google Maps API.

  2. What's a Nice Hummingbird Like You Doing at an AGU Meeting Like This? (or, Operation RubyThroat Meets The GLOBE Program)

    Science.gov (United States)

    Hilton, B.

    2003-12-01

    "Operation RubyThroat: The Hummingbird Project" is an international cross-disciplinary initiative that uses Ruby-throated Hummingbirds (Archilochus colubris) as a hook to excite K-12 students (and adults) about science learning. In 2002, Operation RubyThroat affiliated with The GLOBE Program as the first GLOBE protocol that involves animal behavior. Through Operation RubyThroat, students make observations about hummingbird phenology, behavior, and ecology and correlate their data against traditional GLOBE observations of atmosphere, climate, land cover, soils, hydrology, and phenology. Although Ruby-throated Hummingbirds (RTHUs) breed throughout the eastern half of the United States and southern Canada and may be the most common and most widely distributed of all 338 hummingbird species, little is known about how abiotic environmental factors affect their migration, nesting activities, and everyday behavior. Operation RubyThroat participants in the U.S. and Canada log early arrival dates of RTHUs during spring migration, note their presence throughout the breeding season, and report the last date RTHUs are seen in autumn. Conversely, participants in Mexico and all seven Central American countries (the region in which RTHUs spend their non-breeding months) watch for early arrivals in fall and late departures in spring. Participants also attempt to estimate numbers of RTHUs in local populations by counting the number of visits hummingbirds make to feeders and/or flowers in a 45-minute time block. Optional activities include observations of RTHU nesting behaviors and determining RTHU preferences for various species of native and exotic nectar sources. Participating schools are encouraged to establish Schoolyard Hummingbird Habitats in which to make their observations, but data may be collected in backyards or at local parks, nature centers, botanical gardens, and other sites where RTHUs occur. Adults not affiliated with K-12 schools are invited to become certified in

  3. Phylogenetic systematics and biogeography of hummingbirds: Bayesian and maximum likelihood analyses of partitioned data and selection of an appropriate partitioning strategy.

    Science.gov (United States)

    McGuire, Jimmy A; Witt, Christopher C; Altshuler, Douglas L; Remsen, J V

    2007-10-01

    Hummingbirds are an important model system in avian biology, but to date the group has been the subject of remarkably few phylogenetic investigations. Here we present partitioned Bayesian and maximum likelihood phylogenetic analyses for 151 of approximately 330 species of hummingbirds and 12 outgroup taxa based on two protein-coding mitochondrial genes (ND2 and ND4), flanking tRNAs, and two nuclear introns (AK1 and BFib). We analyzed these data under several partitioning strategies ranging between unpartitioned and a maximum of nine partitions. In order to select a statistically justified partitioning strategy following partitioned Bayesian analysis, we considered four alternative criteria including Bayes factors, modified versions of the Akaike information criterion for small sample sizes (AIC(c)), Bayesian information criterion (BIC), and a decision-theoretic methodology (DT). Following partitioned maximum likelihood analyses, we selected a best-fitting strategy using hierarchical likelihood ratio tests (hLRTS), the conventional AICc, BIC, and DT, concluding that the most stringent criterion, the performance-based DT, was the most appropriate methodology for selecting amongst partitioning strategies. In the context of our well-resolved and well-supported phylogenetic estimate, we consider the historical biogeography of hummingbirds using ancestral state reconstructions of (1) primary geographic region of occurrence (i.e., South America, Central America, North America, Greater Antilles, Lesser Antilles), (2) Andean or non-Andean geographic distribution, and (3) minimum elevational occurrence. These analyses indicate that the basal hummingbird assemblages originated in the lowlands of South America, that most of the principle clades of hummingbirds (all but Mountain Gems and possibly Bees) originated on this continent, and that there have been many (at least 30) independent invasions of other primary landmasses, especially Central America.

  4. Research on performance requirements of turbofan engine used on carrier-based UAV

    Science.gov (United States)

    Zhao, Shufan; Li, Benwei; Zhang, Wenlong; Wu, Heng; Feng, Tang

    2017-05-01

    According to the mission requirements of the carrier-based unmanned aerial vehicle (UAV), a mode level flight was established to calculate the thrust requirements from altitude 9 km to 13 km. Then, the estimation method of flight profile was used to calculate the weight of UAV in each stage to get the specific fuel consumption requirements of the UAV in standby stage. The turbofan engine of carrier-based UAV should meet the thrust and specific fuel consumption requirements. Finally, the GSP software was used to verify the simulation of a small high-bypass turbofan engine. The conclusion is useful for the turbofan engine selection of carrier-based UAV.

  5. Applied Integrated Design in Composite UAV Development

    Science.gov (United States)

    Vasić, Zoran; Maksimović, Stevan; Georgijević, Dragutin

    2017-06-01

    This paper presents a modern approach to integrated development of Unmanned Aerial Vehicle made of laminated composite materials from conceptual design, through detail design, strength and stiffness analyses, definition and management of design and production data, detailed tests results and other activities related to development of laminated composite structures with main of its particularities in comparison to metal structures. Special attention in this work is focused to management processes of product data during life cycle of an UAV and experimental tests of its composite wing. Experience shows that the automation management processes of product data during life cycle, as well as processes of manufacturing, are inevitable if a company wants to get cheaper and quality composite aircraft structures. One of the most effective ways of successful management of product data today is Product Life cycle Management (PLM). In terms of the PLM, a spectrum of special measures and provisions has to be implemented when defining fiber-reinforced composite material structures in comparison to designing with metals which is elaborated in the paper.

  6. A Turbine-powered UAV Controls Testbed

    Science.gov (United States)

    Motter, Mark A.; High, James W.; Guerreiro, Nelson M.; Chambers, Ryan S.; Howard, Keith D.

    2007-01-01

    The latest version of the NASA Flying Controls Testbed (FLiC) integrates commercial-off-the-shelf components including airframe, autopilot, and a small turbine engine to provide a low cost experimental flight controls testbed capable of sustained speeds up to 200 mph. The series of flight tests leading up to the demonstrated performance of the vehicle in sustained, autopiloted 200 mph flight at NASA Wallops Flight Facility's UAV runway in August 2006 will be described. Earlier versions of the FLiC were based on a modified Army target drone, AN/FQM-117B, developed as part of a collaboration between the Aviation Applied Technology Directorate at Fort Eustis, Virginia and NASA Langley Research Center. The newer turbine powered platform (J-FLiC) builds on the successes using the relatively smaller, slower and less expensive unmanned aerial vehicle developed specifically to test highly experimental flight control approaches with the implementation of C-coded experimental controllers. Tracking video was taken during the test flights at Wallops and will be available for presentation at the conference. Analysis of flight data from both remotely piloted and autopiloted flights will be presented. Candidate experimental controllers for implementation will be discussed. It is anticipated that flight testing will resume in Spring 2007 and those results will be included, if possible.

  7. Detection of Citrus Trees from Uav Dsms

    Science.gov (United States)

    Ok, A. O.; Ozdarici-Ok, A.

    2017-05-01

    This paper presents an automated approach to detect citrus trees from digitals surface models (DSMs) as a single source. The DSMs in this study are generated from Unmanned Aerial Vehicles (UAVs), and the proposed approach first considers the symmetric nature of the citrus trees, and it computes the orientation-based radial symmetry in an efficient way. The approach also takes into account the local maxima (LM) information to verify the output of the radial symmetry. Our contributions in this study are twofold: (i) Such an integrated approach (symmetry + LM) has not been tested to detect (citrus) trees (in orchards), and (ii) the validity of such an integrated approach has not been experienced for an input, e.g. a single DSM. Experiments are performed on five test patches. The results reveal that our approach is capable of counting most of the citrus trees without manual intervention. Comparison to the state-of-the-art reveals that the proposed approach provides notable detection performance by providing the best balance between precision and recall measures.

  8. PERFORMANCE TEST ON UAV-BASED PHOTOGRAMMETRIC DATA COLLECTION

    Directory of Open Access Journals (Sweden)

    N. Haala

    2012-09-01

    Full Text Available UAVs are becoming standard platforms for applications aiming at photogrammetric data capture. Since these systems can be completely built-up at very reasonable prices, their use can be very cost effective. This is especially true while aiming at large scale aerial mapping of areas at limited extent. Within the paper the capability of UAV-based data collection will be evaluated. These investigations will be based on flights performed at a photogrammetric test site which was already flown during extensive tests of digital photogrammetric camera systems. Thus, a comparison to conventional aerial survey with state-of-the-art digital airborne camera systems is feasible. Due to this reason the efficiency and quality of generating standard mapping products like DSM and ortho images from UAV flights in photogrammetric block configuration will be discussed.

  9. Trajectory tracking of an underactuated fixed-wing UAV

    Science.gov (United States)

    Oland, Espen; Kristiansen, Raymond

    2014-12-01

    This paper presents a solution to the problem of trajectory tracking for a fixed-wing UAV. With its inherent actuator constraints, a fixed-wing UAV is not able to track an arbitrary trajectory, such that a guidance scheme is required in order to solve the trajectory tracking problem. In this paper, this is solved by first designing a virtual saturated control law that makes the position and velocity errors go to zero. Then the outputs from the virtual control law are mapped onto actuated variables that can be tracked using the available actuators. To that end, a model-based proportional speed controller and a quaternion-based sliding surface controller are presented, making all the errors go to zero. The solution is proved using Lyapunov theory and is validated through simulations where a fixed-wing UAV tracks a circular trajectory.

  10. WORKFLOW FOR BUILDING A HYPERSPECTRAL UAV: CHALLENGES AND OPPORTUNITIES

    Directory of Open Access Journals (Sweden)

    C. Proctor

    2015-08-01

    Full Text Available Owing to the limited payload capacities of most UAV platforms within an academic research budget, many UAV systems utilize commercial RGB cameras or modified sensors with some capacity for sensing in the NIR. However, many applications require higher spectral fidelity that only hyperspectral sensors can offer. For instance, the Photochemical Reflectance Index relies upon the narrow band absorbance of xanthophyll pigments at 531 and 570nm to quantify photosynthetic light use efficiency which are important indicators of productivity and stress in agricultural and forest ecosystems. Thus, our research group has been working on building a research paradigm around a commercial off-the-shelf hyperspectral sensor and UAV. This paper discusses some of the key decisions made regarding selection of equipment and navigating the regulatory and logistical landmines. The imagery collected to date and the options available to process and utilize hyperspectral data are discussed at the end.

  11. UAV Based Imaging for Crop, Weed and Disease Monitoring

    DEFF Research Database (Denmark)

    Garcia Ruiz, Francisco Jose

    the physiological status of the vegetation. UAV imagery may be divided into three steps (1) spectral characterization of the targets of interest, (2) flight and image acquisition and (3) image processing and interpretation. The overall aims of this study were to improve knowledge in all three steps associated...... arvensis L.) and to investigate the possibilities of spectral based discrimination of the species. (2) To perform image based classification of crop-weed in sugar beet crops and health status in orange tree orchards and (3) to describe crop cover heterogeneity from images acquired with UAV. This thesis...... spectroradiometer and raised the feasibility of discriminating the two types of plants with a reasonably high success rate using multispectral images centered on four to six narrow bands. Moreover, UAV remote sensing arises as a potential tool for HLB virus monitoring in citrus trees, although further work...

  12. UAV Observations of an Antarctic Polynya During Winter

    Science.gov (United States)

    Cassano, J.; Maslanik, J. A.; Knuth, S.

    2009-12-01

    Aerosonde unmanned aerial vehicles (UAVs) will be used during September 2009 to observe the atmosphere and ocean / sea ice surface state in the vicinity of the Terra Nova Bay polynya, Antarctica. The flights will take place at the end of the Antarctic winter, in an environment characterized by strong katabatic winds and strong air-sea fluxes. Flights of up to 20 hours duration are planned. This mission will be the second deployment of UAVs in the Antarctic, and the first deployment funded by the United States National Science Foundation. Results from this UAV deployment and lessons learned during the deployment will be presented. Visible satellite image of Terra Nova Bay polynya (6 Oct 2007).

  13. UAV FOR GEODATA ACQUISITION IN AGRICULTUREAL AND FORESTAL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    P. Reidelstürz

    2012-09-01

    The airframe´s wingspan is about 3,45m weighting 4.2 kg, ready to fly. The hand launchable UAV can start from any place in agricultural regions. The wing is configured with flaps, allowing steep approaches and short landings using a „butterfly“ brake configuration. In spite of the lightweight configuration the UAV yet proves its worth under windy baltic wether situations by collecting regular sharp images of fields under wind speed up to 15m/s (Beaufort 6 –7. In further projects the development of further payload modules and a user friendly flight planning tool is scheduled considering different payload – and airframe requirements for different precision farming purposes and forest applications. Data processing and workflow will be optimized. Cooperation with further partners to establish UAV systems in agricultural, forest and geodata aquisition is desired.

  14. Uav for Geodata Acquisition in Agricultureal and Forestal Applications

    Science.gov (United States)

    Reidelstürz, P.; Schrenk, L.; Littmann, W.

    2011-09-01

    In the field of precision-farming research, solutions are worked out to combine ecological and economical requirements in a harmonic way. Integrating hightech in agricultural machinery, natural differences in the fields (biodiversity) can be detected and considered to economize agricultural resources and to give respect to natural ecological variability at the same time. Using precision farming resources, machining - and labour time can be economized, productivness can be improved, environmental burden can be discharged and documentation of production processes can be improved. To realize precision farming it is essential to make contemporary large scale data of the biodiversity in the field available. In the last years effectual traktor based equipment for real time precision farming applications was developed. Using remote sensing, biomass diversity of the field can be considered while applicating operating ressources economicly. Because these large scale data aquisition depends on expensive tractor based inspections, capable Unmanned Aerial Vehicles (UAVs) could complement or in special situations even replace such tractor based data aquisition needed for the realization of precision farming strategies. The specific advantages and application slots of UAVs seems to be ideal for the usage in the field of precision farming. For example the size of even large agricultural fields in germany can be managed even by smaller UAVs. Data can be captured spontaneously, promptly, in large scale, with less respect of weather conditions. In agricultural regions UAV flights can be arranged in visual range as actually the legislator requires in germany, especially because the use of autopilotsystems in fact is nessecary to assure regular area-wide data without gaps but not to fly in non-visible regions. Also a minimized risk of hazard is given, flying UAVs over deserted agricultural areas. In a first stage CIS GmbH cooperated with "Institute For Flightsystems" of the University

  15. Demonstration of UAV deployment and control of mobile wireless sensing networks for modal analysis of structures

    Science.gov (United States)

    Zhou, Hao; Hirose, Mitsuhito; Greenwood, William; Xiao, Yong; Lynch, Jerome; Zekkos, Dimitrios; Kamat, Vineet

    2016-04-01

    Unmanned aerial vehicles (UAVs) can serve as a powerful mobile sensing platform for assessing the health of civil infrastructure systems. To date, the majority of their uses have been dedicated to vision and laser-based spatial imaging using on-board cameras and LiDAR units, respectively. Comparatively less work has focused on integration of other sensing modalities relevant to structural monitoring applications. The overarching goal of this study is to explore the ability for UAVs to deploy a network of wireless sensors on structures for controlled vibration testing. The study develops a UAV platform with an integrated robotic gripper that can be used to install wireless sensors in structures, drop a heavy weight for the introduction of impact loads, and to uninstall wireless sensors for reinstallation elsewhere. A pose estimation algorithm is embedded in the UAV to estimate the location of the UAV during sensor placement and impact load introduction. The Martlet wireless sensor network architecture is integrated with the UAV to provide the UAV a mobile sensing capability. The UAV is programmed to command field deployed Martlets, aggregate and temporarily store data from the wireless sensor network, and to communicate data to a fixed base station on site. This study demonstrates the integrated UAV system using a simply supported beam in the lab with Martlet wireless sensors placed by the UAV and impact load testing performed. The study verifies the feasibility of the integrated UAV-wireless monitoring system architecture with accurate modal characteristics of the beam estimated by modal analysis.

  16. Design of a hybrid rocket / inflatable wing UAV

    Science.gov (United States)

    Sudduth, Cory

    This paper discusses the design challenges and development of a UAV that transitions from a rocket, which allows the aircraft to reach a target altitude rapidly, and then deploys an inflatable wing from an enclosed shell in midflight to allow for loitering and surveillance. The wing deployment and transition is tested in static and dynamic environments, while the performance and stability of both the aircraft mode and rocket mode are examined analytically. An in-depth discussion of key components, including the design, analysis and testing, is also included. Designing an UAV that transitions from a high velocity rocket, to a slow velocity UAV provides many difficult and unique design challenges. For example, the incorporation of deployable wing technology into a full UAV system results in many design constraints. In this particular design inflatable wings are used to generate lift during aircraft mode, and the stabilizing fins for the main wing also acted as the fins for the vehicle during its rocket phase. This required the balancing of the two different vehicle configurations to ensure that the aircraft would be able to fly stably in both modes, and transition between them without catastrophic failure. Significant research, and testing went into the finding the best method of storing the inflatable wing, as well as finding the required inflation rate to minimize unsteady aerodynamic affects. Design work was also invested in the development of an inflation system, as it had to be highly reliable, and yet very light weight for use in this small UAV. This paper discusses how these design challenges were overcome, the development and testing of individual sub-components and how they are incorporated into the overall vehicle. The analysis that went into this UAV, as well as methods used to optimize the design in order to minimize weight and maximize the aircraft performance and loitering time is also discussed.

  17. Characteristic analysis on UAV-MIMO channel based on normalized correlation matrix.

    Science.gov (United States)

    Gao, Xi jun; Chen, Zi li; Hu, Yong Jiang

    2014-01-01

    Based on the three-dimensional GBSBCM (geometrically based double bounce cylinder model) channel model of MIMO for unmanned aerial vehicle (UAV), the simple form of UAV space-time-frequency channel correlation function which includes the LOS, SPE, and DIF components is presented. By the methods of channel matrix decomposition and coefficient normalization, the analytic formula of UAV-MIMO normalized correlation matrix is deduced. This formula can be used directly to analyze the condition number of UAV-MIMO channel matrix, the channel capacity, and other characteristic parameters. The simulation results show that this channel correlation matrix can be applied to describe the changes of UAV-MIMO channel characteristics under different parameter settings comprehensively. This analysis method provides a theoretical basis for improving the transmission performance of UAV-MIMO channel. The development of MIMO technology shows practical application value in the field of UAV communication.

  18. Detection of mini-UAVs in the presence of strong topographic relief: a multisensor perspective

    Science.gov (United States)

    Böniger, Urs; Ott, Beat; Wellig, Peter; Aulenbacher, Uwe; Klare, Jens; Nussbaumer, Thomas; Leblebici, Yusuf

    2016-10-01

    Based on the steadily growing use of mini-UAVs for numerous civilian and military applications, mini-UAVs have been recognized as an increasing potential threat. Therefore, counter-UAV solutions addressing the peculiarities of this class of UAVs have recently received a significant amount of attention. Reliable detection, localization, identification and tracking represents a fundamental prerequisite for such counter-UAV systems. In this paper, we focus on the assessment of different sensor technologies and their ability to detect mini-UAVs in a representative rural Swiss environment. We conducted a field trial in August 2015, using different, primarily short range, experimental sensor systems from armasuisse and selected research partners. After an introduction into the challenges for UAV detection in regions with strong topographic relief, we will introduce the experimental setup and describe the key results from this joint experiment.

  19. Energy-Efficient Systems Eliminate Icing Danger for UAVs

    Science.gov (United States)

    2010-01-01

    Ames Research Center engineer Leonard Haslim invented an anti-icing t echnology called an electroexpulsive separation system, which uses m echanical force to shatter potentially dangerous ice buildup on an ai rcraft surface. Temecula, California-based Ice Management Systems (no w known as IMS-ESS) licensed the technology from Ames and has discov ered a niche market for the lightweight, energy-efficient technology: unmanned aerial vehicles (UAVs). IMS-ESS systems now prevent damagi ng ice accumulation on military UAVs, allowing the vehicles to carry out crucial missions year round.

  20. Ortofotomappa del sito archeologico di Ur da UAV

    Directory of Open Access Journals (Sweden)

    Renzo Carlucci

    2014-09-01

    Full Text Available Ortofotomappa realizzata con oltre 100 fotogrammi ripresi con voloaerofotogrammetrico operato con UAV (Unmanned Aerial Vehicle sul sito archeologico di UR Riprese effettuate con UAV FlyGEO della FlyTop di Roma, con apertura alare di 195 cm e lunghezza 75 cm, peso al decollo di 1.8 kg con motore elettrico 550 Watt alimentato da batteria ai polimeri di litio 11,1V - 4000mAh con autonomia massima di 45 minuti lanciato a mano.

  1. Autonomous and cooperative multi-UAV guidance in adversarial environment

    Science.gov (United States)

    Zengin, Ugur

    The research presented in this dissertation is aimed at developing rule-based autonomous and cooperative guidance strategies for UAVs to perform missions such as path planning, target tracking and rendezvous while reducing their risk/threat exposure level, and avoiding threats and/or obstacles by utilizing measurement information provided by sensors. First, a mathematical formulation is developed to represent the area of operation that contains various types of threats, obstacles, and restricted areas, in a single framework. Once constructed, there will be no need to distinguish between threats, obstacles and restricted areas as the framework already contains the information on what needs to be avoided and the level of penalty for a given position in the area. This framework provides the mathematical foundation for the guidance strategies to make intelligent decisions during the execution of the mission and also provides scalar metrics to assess the performance of a guidance strategy in a given mission. The autonomous guidance strategies are developed by using a rule-based expert system approach with the requirements of completing assigned mission or task, avoiding obstacle/restricted-areas, minimizing threat exposure level, considering the dynamic and communication constraints of the UAVs and avoiding collision. All these requirements and objectives are quantified and prioritized to facilitate the development of guidance algorithms that can be executed in real-time. The strategies consist of a set of "decision states", which contain rules to determine how the host UAV should move by generating heading and speed signals. Cooperation of multiple UAVs is modeled by minimizing a cost function, which is constructed based on the level of threat exposure for each UAV and distance of each UAV relative to the target. This improves the performance of the system in the terms of increasing the total area of coverage of the sensors onboard the UAVs, increasing the flexibility

  2. Modelling and Verification of Multiple UAV Mission Using SMV

    CERN Document Server

    Sirigineedi, Gopinadh; White, Brian A; Zbikowski, Rafal

    2010-01-01

    Model checking has been used to verify the correctness of digital circuits, security protocols, communication protocols, as they can be modelled by means of finite state transition model. However, modelling the behaviour of hybrid systems like UAVs in a Kripke model is challenging. This work is aimed at capturing the behaviour of an UAV performing cooperative search mission into a Kripke model, so as to verify it against the temporal properties expressed in Computation Tree Logic (CTL). SMV model checker is used for the purpose of model checking.

  3. Modelling and Verification of Multiple UAV Mission Using SMV

    Directory of Open Access Journals (Sweden)

    Gopinadh Sirigineedi

    2010-03-01

    Full Text Available Model checking has been used to verify the correctness of digital circuits, security protocols, communication protocols, as they can be modelled by means of finite state transition model. However, modelling the behaviour of hybrid systems like UAVs in a Kripke model is challenging. This work is aimed at capturing the behaviour of an UAV performing cooperative search mission into a Kripke model, so as to verify it against the temporal properties expressed in Computational Tree Logic (CTL. SMV model checker is used for the purpose of model checking.

  4. OBJECT-BASED CHANGE DETECTION USING GEOREFERENCED UAV IMAGES

    Directory of Open Access Journals (Sweden)

    J. Shi

    2012-09-01

    Full Text Available Unmanned aerial vehicles (UAV have been widely used to capture and down-link real-time videos/images. However, their role as a low-cost airborne platform for capturing high-resolution, geo-referenced still imagery has not been fully utilized. The images obtained from UAV are advantageous over remote sensing images as they can be obtained at a low cost and potentially no risk to human life. However, these images are distorted due to the noise generated by the rotary wings which limits the usefulness of such images. One potential application of such images is to detect changes between the images of the same area which are collected over time. Change detection is of widespread interest due to a large number of applications, including surveillance and civil infrastructure. Although UAVs can provide images with high resolution in a portable and easy way, such images only cover small parts of the entire field of interest and are often with high deformation. Until now, there is not much application of change detection for UAV images. Also the traditional pixel-based change detection method does not give satisfactory results for such images. In this paper, we have proposed a novel object-based method for change detection using UAV images which can overcome the effect of deformation and can fully utilize the high resolution capability of UAV images. The developed method can be divided into five main blocks: pre-processing, image matching, image segmentation and feature extraction, change detection and accuracy evaluation. The pre-processing step is further divided into two sub-steps: the first sub-step is to geometrically correct the bi-temporal image based on the geo-reference information (GPS/INS installed on the UAV system, and the second sub-step is the radiometric normalization using a histogram method. The image matching block uses the well-known scale-invariant feature transform (SIFT algorithm to match the same areas in the images and then

  5. Swarm UAV Attack: How to Protect Sensitive Data?

    OpenAIRE

    Erra, Robert; GUYOT, Vincent; Avanthey, Loïca; Gademer, Antoine; Beaudoin, Laurent

    2012-01-01

    International audience; We consider the following scenario: a swarm of UAVs has a mission and a UAV from it has been captured: is it possible to secure (in a broad sense) the sensitive data and software in such a way as to avoid any information leak in this situation. In this article we study a possible solution using in a complementary way: an embedded secure token (a smartcard); Shamir's secret sharing algorithm associated to k-ary goodware. Either of these tools can bring a very high level...

  6. Métodos reactivos basados en campos potenciales para UAVs

    OpenAIRE

    Mera Prieto, Carmen

    2015-01-01

    Este trabajo presenta un método reactivo para evitar colisiones de vehículos aéreos no tripulados (Unmanned Aerial Vehicles, UAVs, en inglés) mofificando la trayectoria. El método reactivo implementado está basado en campos potenciales. El objetivo es que cualquier vehículo aéreo no tripulado (UAV) alcance las posiciones deseadas desde una posición de inicio y siguiendo un plan de vuelo, evitando las posibles colisiones con el entorno que se detecten durante el vuelo. Se ha rea...

  7. "Hummingbird" floral traits interact synergistically to discourage visitation by bumble bee foragers.

    Science.gov (United States)

    Gegear, Robert J; Burns, Rebecca; Swoboda-Bhattarai, Katharine A

    2017-02-01

    Pollination syndromes are suites of floral traits presumed to reflect adaptations to attract and utilize a "primary" type of animal pollinator. However, syndrome traits may also function to deter "secondary" flower visitors that reduce plant fitness through their foraging activities. Here we use the hummingbird-pollinated plant species Mimulus cardinalis as a model to investigate the potential deterrent effects of classic bird syndrome traits on bumble bee foragers. To establish that M. cardinalis flowers elicit an avoidance response in bees, we assessed the choice behavior of individual foragers on a mixed experimental array of M. cardinalis and its bee-pollinated sister species M. lewisii. As expected, bees showed a strong preference against M. cardinalis flowers (only 22% of total bee visits were to M. cardinalis), but surprisingly also showed a high degree of individual specialization (95.2% of total plant transitions were between conspecifics). To determine M. cardinalis floral traits that discourage bee visitation, we then assessed foraging responses of individuals to M. cardinalis-like and M. lewisii-like floral models differing in color, orientation, reward, and combinations thereof. Across experiments, M. cardinalis-like trait combinations consistently produced a higher degree of flower avoidance behavior and individual specialization than expected based on bee responses to each trait in isolation. We then conducted a series of flower discrimination experiments to assess the ability of bees to utilize traits and trait combinations associated with each species. Relative to M. lewisii-like alternatives, M. cardinalis-like traits alone had a minimal effect on bee foraging proficiency but together increased the time bees spent searching for rewarding flowers from 1.49 to 2.65 s per visit. Collectively, our results show that M. cardinalis flowers impose foraging costs on bumble bees sufficient to discourage visitation and remarkably, generate such

  8. Radar sensing via a Micro-UAV-borne system

    Science.gov (United States)

    Catapano, Ilaria; Ludeno, Giovanni; Gennarelli, Gianluca; Soldovieri, Francesco; Rodi Vetrella, Amedeo; Fasano, Giancarmine

    2017-04-01

    In recent years, the miniaturization of flight control systems and payloads has contributed to a fast and widespread diffusion of micro-UAV (Unmanned Aircraft Vehicle). While micro-UAV can be a powerful tool in several civil applications such as environmental monitoring and surveillance, unleashing their full potential for societal benefits requires augmenting their sensing capability beyond the realm of active/passive optical sensors [1]. In this frame, radar systems are drawing attention since they allow performing missions in all-weather and day/night conditions and, thanks to the microwave ability to penetrate opaque media, they enable the detection and localization not only of surface objects but also of sub-surface/hidden targets. However, micro-UAV-borne radar imaging represents still a new frontier, since it is much more than a matter of technology miniaturization or payload installation, which can take advantage of the newly developed ultralight systems. Indeed, micro-UAV-borne radar imaging entails scientific challenges in terms of electromagnetic modeling and knowledge of flight dynamics and control. As a consequence, despite Synthetic Aperture Radar (SAR) imaging is a traditional remote sensing tool, its adaptation to micro-UAV is an open issue and so far only few case studies concerning the integration of SAR and UAV technologies have been reported worldwide [2]. In addition, only early results concerning subsurface imaging by means of an UAV-mounted radar are available [3]. As a contribution to radar imaging via autonomous micro-UAV, this communication presents a proof-of-concept experiment. This experiment represents the first step towards the development of a general methodological approach that exploits expertise about (sub-)surface imaging and aerospace systems with the aim to provide high-resolution images of the surveyed scene. In details, at the conference, we will present the results of a flight campaign carried out by using a single radar

  9. Unmanned Aerial Vehicles (UAVs): a new tool in counterterrorism operations?

    Science.gov (United States)

    Dörtbudak, Mehmet F.

    2015-05-01

    Terrorism is not a new phenomenon to the world, yet it remains difficult to define and counter. Countering terrorism requires several measures that must be taken simultaneously; however, counterterrorism strategies of many countries mostly depend on military measures. In the aftermath of the 2001 terrorist attack on the Twin Towers of the World Trade Center, the United States (U.S.) has started and led the campaign of Global War on Terrorism. They have invaded Afghanistan and Iraq and have encountered insurgencies run by terrorist organizations, such as al-Qaeda and its affiliates. The U.S. made the utilization of Air and Space Power very intensively during these operations. In order to implement operations; Intelligence, Surveillance, and Reconnaissance (ISR) assets were used to collect the necessary information. Before the successful insertion of a small number of U.S. Special Operation Force (SOF) teams into Afghanistan, the U.S. Air Force attacked al-Qaeda and Taliban's targets such as infrastructure, airfields, ground forces, command-control facilities etc. As soon as the U.S. troops got on the ground and started to marshal to Kabul, the Air Force supported them by attacking jointly determined targets. The Air Force continued to carry out the missions and played a significant role to achieve the objective of operation during all the time. This is not the only example of utilization of Air and Space Power in counterterrorism and counterinsurgency operations. All around the world, many countries have also made the utilization of Air Power in different missions ranging from ISR to attacking. Thinking that terrorism has a psychological dimension and losing a pilot during operations may result in decreasing the population support to operations, Unmanned Aerial Vehicles (UAVs) started to be used by practitioners and took priority over other assets. Although UAVs have been on the theatre for a long time used for ISR mission in conventional conflicts, with the advent

  10. Effect of flower shape and size on foraging performance and trade-offs in a tropical hummingbird.

    Science.gov (United States)

    Temeles, Ethan J; Koulouris, Carolyn R; Sander, Sarah E; Kress, W John

    2009-05-01

    Matches between the bills of hummingbirds and the flowers they visit have been interpreted as examples of coadaptation and feeding specialization. Observations of birds feeding at flowers longer or shorter than their bills combined with a lack of experimental evidence for foraging trade-offs, however, fail to support these interpretations. We addressed these inconsistencies by considering a seldom-studied dimension of hummingbird-flower relationships, the shape of bills and flowers, through experiments on the Purple-throated Carib, Eulampis jugularis, and its major food plant, Heliconia, in the eastern Caribbean. Bills of male E. jugularis are considerably shorter and straighter than bills of females. We examined foraging performances and trade-offs during visits to natural heliconias and 34 artificial flowers of differing length and curvature. Supporting predictions based on matches between bill and flower morphology, handling times of females were significantly shorter than those of males at the long, curved flowers of a green morph of H. bihai. Contrary to predictions, handling times of males were not significantly shorter than handling times of females at the short flowers of H. caribaea. At artificial flowers, maximum extraction depths of females were significantly longer than maximum extraction depths of males at all curved flowers, but not at straight flowers. Handling times of females were significantly shorter than handling times of males at the longest artificial flowers for all curvatures, whereas handling times of males were significantly shorter at short, straight, artificial flowers, but only while hover-feeding without a perch. Within each sex, handling times were inversely related to bill length at long flowers for all shapes. Taken together, these performance trade-offs suggest that the long, curved bills of females are adapted for feeding from long, curved flowers, whereas the short bills of males are adapted for hover-feeding from short

  11. Advances in flash flood monitoring using UAVs

    Science.gov (United States)

    Perks, Matthew; Russell, Andrew; Large, Andrew

    2016-04-01

    UAVs have the potential to capture information about the earth's surface in dangerous and previously inaccessible locations. Through image acquisition of flash flood events and subsequent object-based analysis, highly dynamic and oft-immeasurable hydraulic phenomenon may be quantified at previously unattainable spatial and temporal resolutions. The potential for this approach to provide valuable information about the hydraulic conditions present during dynamic, high-energy flash floods has until now not been explored. In this paper we adopt a novel approach, utilising the Kande-Lucas-Tomasi (KLT) algorithm to track features present on the water surface which are related to the free-surface velocity. Following the successful tracking of features, a method analogous to the vector correction method has enabled accurate geometric rectification of velocity vectors. Uncertainties associated with the rectification process induced by unsteady camera movements are subsequently explored. Geo-registration errors are relatively stable and occur as a result of persistent residual distortion effects following image correction. The apparent ground movement of immobile control points between measurement intervals ranges from 0.05 - 0.13m. The application of this approach to assess the hydraulic conditions present in Alyth Burn, Scotland during a 1:200 year flash flood resulted in the generation of an average 4.2 measurements/m2 at a rate of 508 measurements/s. Analysis of these vectors provide a rare insight into the complexity of channel-overbank interactions during flash floods. The uncertainty attached to the calculated velocities is relatively low with a spatial average across the area of ± 0.15m/s. Little difference is observed in the uncertainty attached to out-of-bank velocities (± 0.15m/s), and within-channel velocities (± 0.16m/s), illustrating the consistency of the approach.

  12. Sistema sensorial embarcado en un mini-UAV para la medida de las variables ambientales de un invernadero

    OpenAIRE

    Roldán Gómez, Juan Jesús

    2014-01-01

    Este trabajo desarrolla un sistema sensorial a bordo de un quadrotor para medir las variables ambientales de un invernadero. El trabajo tiene dos vertientes: por un lado, la selección de los sensores de temperatura, humedad, luminosidad y concentración de CO2 y su integración en el robot aéreo y, por el otro, el desarrollo de algoritmos para el guiado, la navegación y el control del quadrotor en el invernadero.

  13. A system of UAV application in indoor environment

    DEFF Research Database (Denmark)

    Khosiawan, Yohanes; Nielsen, Izabela Ewa

    2016-01-01

    In recent years, there has been an increased demand in the use of multiple unmanned aerial vehicles (UAVs) in indoor environments such as material handling task in a manufacturing environment and plant/environment monitoring task in a greenhouse. However, there is a lack of work reported...

  14. Feasibility of Using Synthetic Aperture Radar to Aid UAV Navigation.

    Science.gov (United States)

    Nitti, Davide O; Bovenga, Fabio; Chiaradia, Maria T; Greco, Mario; Pinelli, Gianpaolo

    2015-07-28

    This study explores the potential of Synthetic Aperture Radar (SAR) to aid Unmanned Aerial Vehicle (UAV) navigation when Inertial Navigation System (INS) measurements are not accurate enough to eliminate drifts from a planned trajectory. This problem can affect medium-altitude long-endurance (MALE) UAV class, which permits heavy and wide payloads (as required by SAR) and flights for thousands of kilometres accumulating large drifts. The basic idea is to infer position and attitude of an aerial platform by inspecting both amplitude and phase of SAR images acquired onboard. For the amplitude-based approach, the system navigation corrections are obtained by matching the actual coordinates of ground landmarks with those automatically extracted from the SAR image. When the use of SAR amplitude is unfeasible, the phase content can be exploited through SAR interferometry by using a reference Digital Terrain Model (DTM). A feasibility analysis was carried out to derive system requirements by exploring both radiometric and geometric parameters of the acquisition setting. We showed that MALE UAV, specific commercial navigation sensors and SAR systems, typical landmark position accuracy and classes, and available DTMs lead to estimated UAV coordinates with errors bounded within ±12 m, thus making feasible the proposed SAR-based backup system.

  15. UAV Flight Control using Distributed Actuation and Sensing

    Science.gov (United States)

    Barnwell, William G.; Heinzen, Stearns N.; Hall, Charles E., Jr.; Chokani, Ndaona; Raney, David L. (Technical Monitor)

    2003-01-01

    An array of effectors and sensors has been designed, tested and implemented on a Blended Wing Body Uninhabited Aerial Vehicle (UAV). This UAV is modified to serve as a flying, controls research, testbed. This effectorhensor array provides for the dynamic vehicle testing of controller designs and the study of decentralized control techniques. Each wing of the UAV is equipped with 12 distributed effectors that comprise a segmented array of independently actuated, contoured control surfaces. A single pressure sensor is installed near the base of each effector to provide a measure of deflections of the effectors. The UAV wings were tested in the North Carolina State University Subsonic Wind Tunnel and the pressure distribution that result from the deflections of the effectors are characterized. The results of the experiments are used to develop a simple, but accurate, prediction method, such that for any arrangement of the effector array the corresponding pressure distribution can be determined. Numerical analysis using the panel code CMARC verifies this prediction method.

  16. The future of structural fieldwork - UAV assisted aerial photogrammetry

    Science.gov (United States)

    Vollgger, Stefan; Cruden, Alexander

    2015-04-01

    Unmanned aerial vehicles (UAVs), commonly referred to as drones, are opening new and low cost possibilities to acquire high-resolution aerial images and digital surface models (DSM) for applications in structural geology. UAVs can be programmed to fly autonomously along a user defined grid to systematically capture high-resolution photographs, even in difficult to access areas. The photographs are subsequently processed using software that employ SIFT (scale invariant feature transform) and SFM (structure from motion) algorithms. These photogrammetric routines allow the extraction of spatial information (3D point clouds, digital elevation models, 3D meshes, orthophotos) from 2D images. Depending on flight altitude and camera setup, sub-centimeter spatial resolutions can be achieved. By "digitally mapping" georeferenced 3D models and images, orientation data can be extracted directly and used to analyse the structural framework of the mapped object or area. We present UAV assisted aerial mapping results from a coastal platform near Cape Liptrap (Victoria, Australia), where deformed metasediments of the Palaeozoic Lachlan Fold Belt are exposed. We also show how orientation and spatial information of brittle and ductile structures extracted from the photogrammetric model can be linked to the progressive development of folds and faults in the region. Even though there are both technical and legislative limitations, which might prohibit the use of UAVs without prior commercial licensing and training, the benefits that arise from the resulting high-resolution, photorealistic models can substantially contribute to the collection of new data and insights for applications in structural geology.

  17. UAV Monitoring for Enviromental Management in Galapagos Islands

    Science.gov (United States)

    Ballari, D.; Orellana, D.; Acosta, E.; Espinoza, A.; Morocho, V.

    2016-06-01

    In the Galapagos Islands, where 97% of the territory is protected and ecosystem dynamics are highly vulnerable, timely and accurate information is key for decision making. An appropriate monitoring system must meet two key features: on one hand, being able to capture information in a systematic and regular basis, and on the other hand, to quickly gather information on demand for specific purposes. The lack of such a system for geographic information limits the ability of Galapagos Islands' institutions to evaluate and act upon environmental threats such as invasive species spread and vegetation degradation. In this context, the use of UAVs (unmanned aerial vehicles) for capturing georeferenced images is a promising technology for environmental monitoring and management. This paper explores the potential of UAV images for monitoring degradation of littoral vegetation in Puerto Villamil (Isabela Island, Galapagos, Ecuador). Imagery was captured using two camera types: Red Green Blue (RGB) and Infrarred Red Green (NIR). First, vegetation presence was identified through NDVI. Second, object-based classification was carried out for characterization of vegetation vigor. Results demonstrates the feasibility of UAV technology for base-line studies and monitoring on the amount and vigorousness of littoral vegetation in the Galapagos Islands. It is also showed that UAV images are not only useful for visual interpretation and object delineation, but also to timely produce useful thematic information for environmental management.

  18. Focus-of-attention for human activity recognition from UAVs

    NARCIS (Netherlands)

    Burghouts, G.J.; Eekeren, A.W.M. van; Dijk, J.

    2014-01-01

    This paper presents a system to extract metadata about human activities from full-motion video recorded from a UAV. The pipeline consists of these components: tracking, motion features, representation of the tracks in terms of their motion features, and classification of each track as one of the hum

  19. Fuzzy adaptive PID control for six rotor eppo UAV

    Directory of Open Access Journals (Sweden)

    Yongwei LI

    2017-02-01

    Full Text Available Six rotor eppo drones's load change itself in the job process will reduce the aircraft flight control performance and make the resistance to environmental disturbance being poor. In order to improve the six rotor eppo unmanned aerial vehicle (UAV control performance, the UAV in the process of spraying pesticide is analyzed and the model is constructed, then the eppo UAV time-varying dynamics mathematical model is deduced, and a fuzzy adaptive PID control algorithm is proposed. Fuzzy adaptive PID algorithm has good adaptability and the parameter setting is simple, which improves the system dynamic response and steady state performance, realizing the stability of the six rotor eppo UAV flight. With measured parameters of each sensor input in to the fuzzy adaptive PID algorithm, the corresponding control quality is obtained, and the stable operation of aircraft is realized. Through using Matlab to simulate the flight system and combining the practical experiments, it shows that the dynamic performance and stability of the system is improved effetively.

  20. Center Overview and UAV Highlights at NASA Ames Research Center

    Science.gov (United States)

    Feng, Deborah; Yan, Jerry Chi Yiu

    2017-01-01

    The PowerPoint presentation gives an overview of NASA Ames Research Center and its core competencies, as well as some of the highlights of Unmanned Aerial Vehicle (UAV) and Unmanned Aircraft Systems (UAS) accomplishments and innovations by researchers at Ames.

  1. UAV Digital Tracking Array Design, Development and Testing

    Science.gov (United States)

    2009-12-01

    Voltage-Controlled Oscillator ( VCO ).................................... 57 b. Low-Power Amplifier (LPA...Receive TWS Track While Scan UAV Unmanned Aerial Vehicle USAF United States Air Force VCO Voltage Controlled Oscillator VI Virtual...Loop (PLL) Quadrature Detector A PLL consists of three main components: phase comparator, low pass filter (LPF) and voltage controlled oscillator ( VCO

  2. Autonomous UAV persistent surveillance using bio-inspired strategies

    Science.gov (United States)

    Burman, Jerry; Hespanha, Joao; Madhow, Upamanyu; Isaacs, Jason; Venkateswaran, Sriram; Pham, Tien

    2012-06-01

    A team consisting of Teledyne Scientific Company, the University of California at Santa Barbara, the Army Research Laboratory, the Engineer Research and Development Center, and IBM UK is developing technologies in support of automated data exfiltration from heterogeneous battlefield sensor networks to enhance situational awareness for dismounts and command echelons. Unmanned aerial vehicles (UAV) provide an effective means to autonomously collect data from a sparse network of unattended ground sensors (UGSs) that cannot communicate with each other. UAVs are used to reduce the system reaction time by generating autonomous collection routes that are data-driven. Bioinspired techniques for autonomous search provide a novel strategy to detect, capture and fuse data from heterogeneous sensor networks. The bio-inspired algorithm is based on chemotaxis or the motion of bacteria seeking nutrients in their environment. Field tests of a bio-inspired system that routed UAVs were conducted in June 2011 at Camp Roberts, CA. The field test results showed that such a system can autonomously detect and locate the source of terrestrial events with very high accuracy and visually verify the event. In June 2011, field tests of the system were completed and include the use of multiple autonomously controlled UAVs, detection and disambiguation of multiple acoustic events occurring in short time frames, optimal sensor placement based on local phenomenology and the use of the International Technology Alliance (ITA) Sensor Network Fabric. The system demonstrated TRL 6 performance in the field at Camp Roberts.

  3. Supervising UAVs : improving operator performance by optimizing the human factor

    NARCIS (Netherlands)

    Breda, L. van; Jansen, C.; Veltman, J.A.

    2005-01-01

    Tele-operated unmanned aerial vehicles (UAVs) have no operators on board and therefore enable extension of the present sensing and communication capabilities in civil and military missions, without unnecessarily endangering personnel or deploying expensive material. One should also realize that tele

  4. Focus-of-attention for human activity recognition from UAVs

    NARCIS (Netherlands)

    Burghouts, G.J.; Eekeren, A.W.M. van; Dijk, J.

    2014-01-01

    This paper presents a system to extract metadata about human activities from full-motion video recorded from a UAV. The pipeline consists of these components: tracking, motion features, representation of the tracks in terms of their motion features, and classification of each track as one of the hum

  5. Autonomous Navigation of Small Uavs Based on Vehicle Dynamic Model

    Science.gov (United States)

    Khaghani, M.; Skaloud, J.

    2016-03-01

    This paper presents a novel approach to autonomous navigation for small UAVs, in which the vehicle dynamic model (VDM) serves as the main process model within the navigation filter. The proposed method significantly increases the accuracy and reliability of autonomous navigation, especially for small UAVs with low-cost IMUs on-board. This is achieved with no extra sensor added to the conventional INS/GNSS setup. This improvement is of special interest in case of GNSS outages, where inertial coasting drifts very quickly. In the proposed architecture, the solution to VDM equations provides the estimate of position, velocity, and attitude, which is updated within the navigation filter based on available observations, such as IMU data or GNSS measurements. The VDM is also fed with the control input to the UAV, which is available within the control/autopilot system. The filter is capable of estimating wind velocity and dynamic model parameters, in addition to navigation states and IMU sensor errors. Monte Carlo simulations reveal major improvements in navigation accuracy compared to conventional INS/GNSS navigation system during the autonomous phase, when satellite signals are not available due to physical obstruction or electromagnetic interference for example. In case of GNSS outages of a few minutes, position and attitude accuracy experiences improvements of orders of magnitude compared to inertial coasting. It means that during such scenario, the position-velocity-attitude (PVA) determination is sufficiently accurate to navigate the UAV to a home position without any signal that depends on vehicle environment.

  6. Feasibility of Using Synthetic Aperture Radar to Aid UAV Navigation

    Directory of Open Access Journals (Sweden)

    Davide O. Nitti

    2015-07-01

    Full Text Available This study explores the potential of Synthetic Aperture Radar (SAR to aid Unmanned Aerial Vehicle (UAV navigation when Inertial Navigation System (INS measurements are not accurate enough to eliminate drifts from a planned trajectory. This problem can affect medium-altitude long-endurance (MALE UAV class, which permits heavy and wide payloads (as required by SAR and flights for thousands of kilometres accumulating large drifts. The basic idea is to infer position and attitude of an aerial platform by inspecting both amplitude and phase of SAR images acquired onboard. For the amplitude-based approach, the system navigation corrections are obtained by matching the actual coordinates of ground landmarks with those automatically extracted from the SAR image. When the use of SAR amplitude is unfeasible, the phase content can be exploited through SAR interferometry by using a reference Digital Terrain Model (DTM. A feasibility analysis was carried out to derive system requirements by exploring both radiometric and geometric parameters of the acquisition setting. We showed that MALE UAV, specific commercial navigation sensors and SAR systems, typical landmark position accuracy and classes, and available DTMs lead to estimated UAV coordinates with errors bounded within ±12 m, thus making feasible the proposed SAR-based backup system.

  7. Fuzzy control of attitude of four - rotor UAV

    Science.gov (United States)

    Zhang, Zexiang; Hu, Shengbin

    2017-08-01

    The four - rotor unmanned aerial vehicle (UAV) is the object of study, in this paper. In order to solve the problem of poor robustness and low control precision of the four-rotor unmanned aerial vehicle (UAV) control system, and realized the stability control problem of the four-rotor UAV attitude. First, the dynamic model of the four-rotor unmanned aerial vehicle is established. And on this basis, a fuzzy controller is designed, and used to control the channel. Then, the simulation platform is built by Matlab / Simulink simulation software, and the performance of the designed fuzzy controller is analyzed comprehensively. It is also determined whether the algorithm can control the attitude of the four rotor unmanned aerial vehicle. The simulation results fully verify the accuracy of the model, and proved fuzzy controller has better dynamic performance and robustness under appropriate parameters so that UAVs can fly stable. The algorithm can improve the anti-jamming performance and control accuracy of the system, it has a certain significance for the actual four-rotor aircraft attitude control.

  8. a Light-Weight Laser Scanner for Uav Applications

    Science.gov (United States)

    Tommaselli, A. M. G.; Torres, F. M.

    2016-06-01

    Unmanned Aerial Vehicles (UAV) have been recognized as a tool for geospatial data acquisition due to their flexibility and favourable cost benefit ratio. The practical use of laser scanning devices on-board UAVs is also developing with new experimental and commercial systems. This paper describes a light-weight laser scanning system composed of an IbeoLux scanner, an Inertial Navigation System Span-IGM-S1, from Novatel, a Raspberry PI portable computer, which records data from both systems and an octopter UAV. The performance of this light-weight system was assessed both for accuracy and with respect to point density, using Ground Control Points (GCP) as reference. Two flights were performed with the UAV octopter carrying the equipment. In the first trial, the flight height was 100 m with six strips over a parking area. The second trial was carried out over an urban park with some buildings and artificial targets serving as reference Ground Control Points. In this experiment a flight height of 70 m was chosen to improve target response. Accuracy was assessed based on control points the coordinates of which were measured in the field. Results showed that vertical accuracy with this prototype is around 30 cm, which is acceptable for forest applications but this accuracy can be improved using further refinements in direct georeferencing and in the system calibration.

  9. A LIGHT-WEIGHT LASER SCANNER FOR UAV APPLICATIONS

    Directory of Open Access Journals (Sweden)

    A. M. G. Tommaselli

    2016-06-01

    Full Text Available Unmanned Aerial Vehicles (UAV have been recognized as a tool for geospatial data acquisition due to their flexibility and favourable cost benefit ratio. The practical use of laser scanning devices on-board UAVs is also developing with new experimental and commercial systems. This paper describes a light-weight laser scanning system composed of an IbeoLux scanner, an Inertial Navigation System Span-IGM-S1, from Novatel, a Raspberry PI portable computer, which records data from both systems and an octopter UAV. The performance of this light-weight system was assessed both for accuracy and with respect to point density, using Ground Control Points (GCP as reference. Two flights were performed with the UAV octopter carrying the equipment. In the first trial, the flight height was 100 m with six strips over a parking area. The second trial was carried out over an urban park with some buildings and artificial targets serving as reference Ground Control Points. In this experiment a flight height of 70 m was chosen to improve target response. Accuracy was assessed based on control points the coordinates of which were measured in the field. Results showed that vertical accuracy with this prototype is around 30 cm, which is acceptable for forest applications but this accuracy can be improved using further refinements in direct georeferencing and in the system calibration.

  10. Detecting animals in African Savanna with UAVs and the crowds

    NARCIS (Netherlands)

    Rey, Nicolas; Volpi, Michele; Joost, Stéphane; Tuia, Devis

    2017-01-01

    Unmanned aerial vehicles (UAVs) offer new opportunities for wildlife monitoring, with several advantages over traditional field-based methods. They have readily been used to count birds, marine mammals and large herbivores in different environments, tasks which are routinely performed through manual

  11. Supervising UAVs : improving operator performance by optimizing the human factor

    NARCIS (Netherlands)

    Breda, L. van; Jansen, C.; Veltman, J.A.

    2005-01-01

    Tele-operated unmanned aerial vehicles (UAVs) have no operators on board and therefore enable extension of the present sensing and communication capabilities in civil and military missions, without unnecessarily endangering personnel or deploying expensive material. One should also realize that tele

  12. Radio Channel Modelling for UAV Communication over Cellular Networks

    DEFF Research Database (Denmark)

    Amorim, Rafhael Medeiros de; Nguyen, Huan Cong; Mogensen, Preben Elgaard

    2017-01-01

    The main goal of this paper is to obtain models for path loss exponents and shadowing for the radio channel between airborne Unmanned Aerial Vehicles (UAVs) and cellular networks. In this pursuit, field measurements were conducted in live LTE networks at the 800 MHz frequency band, using...

  13. A system of UAV application in indoor environment

    DEFF Research Database (Denmark)

    Khosiawan, Yohanes; Nielsen, Izabela Ewa

    2016-01-01

    In recent years, there has been an increased demand in the use of multiple unmanned aerial vehicles (UAVs) in indoor environments such as material handling task in a manufacturing environment and plant/environment monitoring task in a greenhouse. However, there is a lack of work reported...

  14. Using perspective guidance overlay to improve UAV manual control performance

    NARCIS (Netherlands)

    Tadema, J.; Theunissen, E.; Koeners, J.

    2007-01-01

    The guidance information that is available to the UAV operator typically suffers from limitations of data update rate and system latency. Even when using a flight director command display, the manual control task is considerably more difficult compared to piloting a manned aircraft. Results from ear

  15. Using perspective guidance overlay to improve UAV manual control performance

    NARCIS (Netherlands)

    Tadema, J.; Theunissen, E.; Koeners, J.

    2007-01-01

    The guidance information that is available to the UAV operator typically suffers from limitations of data update rate and system latency. Even when using a flight director command display, the manual control task is considerably more difficult compared to piloting a manned aircraft. Results from ear

  16. INS/GPS Integrated Navigation Technology for Hypersonic UAV

    Directory of Open Access Journals (Sweden)

    Nana Meng

    2013-07-01

    Full Text Available INS/GPS integrated navigation system is studied in this paper for the hypersonic UAV in order to satisfy the precise guidance requirements of hypersonic UAV and in response to the defects while the inertial navigation system (INS and the global positioning system (GPS are being applied separately. The information of UAV including position, velocity and attitude can be obtained by using INS and GPS respectively after generating a reference trajectory. The corresponding errors of two navigation systems can be obtained through comparing the navigation information of the above two guidance systems. Kalman filter is designed to estimate the navigation errors and then the navigation information of INS are corrected. The non-equivalence relationship between the platform misalignment angle and attitude error angle are considered so that the navigation accuracy is further improved. The Simulink simulation results show that INS/GPS integrated navigation system can help to achieve higher accuracy and better anti-interference ability than INS navigation system and this system can also satisfy the navigation accuracy requirements of hypersonic UAV.  

  17. Stochastic control of light UAV at landing with the aid of bearing-only observations

    Science.gov (United States)

    Miller, Alexander; Miller, Boris

    2015-12-01

    This work considers the tracking of the UAV (unmanned aviation vehicle) at landing on unprepared field. Despite the advantages in UAV guidance the autonomous landing remains to be one of most serious problems. The principal difficulties are the absence of the precise UAV position measurements with respect to the landing field and the action of external atmospheric perturbations (turbulence and wind). So the control problem for UAV landing is the nonlinear stochastic one with incomplete information. The aim of the article is the development of stochastic control algorithms based on pseudomeasurement Kalman filter in the problem of the UAV autonomous landing with the aid of ground-based optical/radio radars in the case of strong wind and large initial error of the UAV entrance into the area covered by radars. The novelty of the article is the joint control-observation algorithm based on unbiased pseudomeasurement Kalman filter which provides the quadratic characteristics of the estimation errors. The later property is highly important for the UAV control based on the data fusion from INS (inertial navigation system) and the bearing observations obtained from external terrain based locators. The principal difficulty in the UAV landing control is the absence of the direct control tools at the terrain end, so the possible control can be based on the angular-range data obtained by terrain locators which must be transmitted from terrain location station to the UAV control unit. Thus the stochastic approach looks very effective in this challenging problem of the UAV landing.

  18. Illumination-invariant image matching for autonomous UAV localisation based on optical sensing

    Science.gov (United States)

    Wan, Xue; Liu, Jianguo; Yan, Hongshi; Morgan, Gareth L. K.

    2016-09-01

    This paper presents an UAV (Unmanned Aerial Vehicle) localisation algorithm for its autonomous navigation based on matching between on-board UAV image sequences to a pre-installed reference satellite image. As the UAV images and the reference image are not necessarily taken under the same illumination condition, illumination-invariant image matching is essential. Based on the investigation of illumination-invariant property of Phase Correlation (PC) via mathematical derivation and experiments, we propose a PC based fast and robust illumination-invariant localisation algorithm for UAV navigation. The algorithm accurately determines the current UAV position as well as the next UAV position even the illumination condition of UAV on-board images is different from the reference satellite image. A Dirac delta function based registration quality assessment together with a risk alarming criterion is introduced to enable the UAV to perform self-correction in case the UAV deviates from the planned route. UAV navigation experiments using simulated terrain shading images and remote sensing images have demonstrated a robust high performance of the proposed PC based localisation algorithm under very different illumination conditions resulted from solar motion. The superiority of the algorithm, in comparison with two other widely used image matching algorithms, MI (Mutual Information) and NCC (Normalised Correlation Coefficient), is significant for its high matching accuracy and fast processing speed.

  19. Specialization in Plant-Hummingbird Networks Is Associated with Species Richness, Contemporary Precipitation and Quaternary Climate-Change Velocity

    DEFF Research Database (Denmark)

    Dalsgaard, Bo; Magård, Else; Fjeldså, Jon

    2011-01-01

    hypothesis is that contemporary biotic specialization is determined by the degree of past climatic instability, primarily Quaternary climate-change velocity. Other prominent hypotheses predict that either contemporary climate or species richness affect biotic specialization. To gain insight into geographical...... latitudes, with latitude explaining 20-22% of the spatial variation in plant-hummingbird specialization. Potential drivers of specialization--contemporary climate, Quaternary climate-change velocity, and species richness--had superior explanatory power, together explaining 53-64% of the variation...... in specialization. Notably, our data provides empirical evidence for the hypothesized roles of species richness, contemporary precipitation and Quaternary climate-change velocity as key predictors of biotic specialization, whereas contemporary temperature and seasonality seem unimportant in determining...

  20. Using crowd sourcing to combat potentially illegal or dangerous UAV operations

    Science.gov (United States)

    Tapsall, Brooke T.

    2016-10-01

    The UAV (Unmanned Aerial Vehicles) industry is growing exponentially at a pace that policy makers, individual countries and law enforcement agencies are finding difficult to keep up. The UAV market is large, as such the amount of UAVs being operated in potentially dangerous situations is prevalent and rapidly increasing. Media is continually reporting `near-miss' incidents between UAVs and commercial aircraft, UAV breaching security in sensitive areas or invading public privacy. One major challenge for law enforcement agencies is gaining tangible evidence against potentially dangerous or illegal UAV operators due to the rapidity with which UAV operators are able to enter, fly and exit a scene before authorities can arrive or before they can be located. DroneALERT, an application available via the Airport-UAV.com website, allows users to capture potentially dangerous or illegal UAV activity using their mobile device as it the incident is occurring. A short online DroneALERT Incident Report (DIR) is produced, emailed to the user and the Airport-UAV.com custodians. The DIR can be used to aid authorities in their investigations. The DIR contains details such as images and videos, location, time, date of the incident, drone model, its distance and height. By analysing information from the DIR, photos or video, there is a high potential for law enforcement authorities to use this evidence to identify the type of UAV used, triangulate the location of the potential dangerous UAV and operator, create a timeline of events, potential areas of operator exit and to determine the legalities breached. All provides crucial evidence for identifying and prosecuting a UAV operator.