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Sample records for autonomous helicopter slung

  1. Adaptive Control System for Autonomous Helicopter Slung Load Operations

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; Bendtsen, Jan Dimon

    2010-01-01

    This paper presents design and verification of an estimation and control system for a helicopter slung load system. The estimator provides position and velocity estimates of the slung load and is designed to augment existing navigation in autonomous helicopters. Sensor input is provided by a vision...

  2. Modeling, Estimation, and Control of Helicopter Slung Load System

    OpenAIRE

    Bisgaard, Morten

    2008-01-01

    Denne afhandling omhandler autonom flyvning med helicopter slung load systemer og præsenterer en metodik der beskriver system udvikling fra modellering og system analyse, over sensor fusion og tilstands estimering, til kontroller design. To forskellige udviklingsgrene præsenteres: Flyvning med generisk slung load og landmine detektion med helikopter slung load system.Et hoved bidrag for denne afhandling er udviklingen af en komplet helikopter og slung load model. Den generiske slung load mode...

  3. Swing Damping for Helicopter Slung Load Systems using Delayed Feedback

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; Bendtsen, Jan Dimon

    2009-01-01

    This paper presents the design and verification of a swing reducing controller for helicopter slung load systems using intentional delayed feedback. It is intended for augmenting a trajectory tracking helicopter controller and thereby improving the slung load handing capabilities for autonomous h...

  4. Modeling, Estimation, and Control of Helicopter Slung Load System

    DEFF Research Database (Denmark)

    Bisgaard, Morten

    . To enable slung load flight capabilities for general cargo transport, an integrated estimation and control system is developed for use on already autonomous helicopters. The estimator uses vision based updates only and needs little prior knowledge of the slung load system as it estimates the length......This thesis treats the subject of autonomous helicopter slung load flight and presents the reader with a methodology describing the development path from modeling and system analysis over sensor fusion and state estimation to controller synthesis. The focus is directed along two different...

  5. Input Shaping for Helicopter Slung Load Swing Reduction

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; Bendtsen, Jan Dimon

    2008-01-01

    This chapter presents a feedforward swing reducing control system for augmenting already existing helicopter controllers and enables slung load flight with autonomous helicopters general cargo transport. The feedforward controller is designed to avoid excitation of the lightly damped modes...... of the system by shaping the reference trajectory using robust input shaping. It is developed as part of an integrated adaptive control system consisting of state estimator, feedforward, and feedback controller capable of simultaneously preventing swing in the slung load from helicopter motion and actively...

  6. Vision Aided State Estimation for Helicopter Slung Load System

    DEFF Research Database (Denmark)

    Bisgaard, Morten; Bendtsen, Jan Dimon; la Cour-Harbo, Anders;

    2007-01-01

    This paper presents the design and verification of a state estimator for a helicopter based slung load system. The estimator is designed to augment the IMU driven estimator found in many helicopter UAV s and uses vision based updates only. The process model used for the estimator is a simple 4...... state acceleration driven pendulum. Sensor input for the filter is provided by a vision based system that measures the position of the slung load. The estimator needs no prior knowledge of the system as it estimates the length of the suspension system together with the system states. Finally...

  7. Full State Estimation for Helicopter Slung Load System

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; Bendtsen, Jan Dimon

    This paper presents the design of a state estimator system for a generic helicopter based slung load system. The estimator is designed to deliver full rigid body state information for both helicopter and load and is based on the unscented Kalman filter. Two different approaches are investigated....... A simple and effective virtual sensor method is developed to maintain the constraints imposed by the wires in the system. The full model based approach uses a complex aerodynamical model to describe the helicopter together with a generic rigid body model. This rigid body model is based on a redundant...... coordinate formulation and can be used to model all body to body slung load suspension systems. Both estimators include bias estimation for the accelerometers and gyros and the model based estimator furthermore includes estimation of external wind disturbances. A vision system is used to measure the motion...

  8. Autonomous vertical autorotation for unmanned helicopters

    Science.gov (United States)

    Dalamagkidis, Konstantinos

    Small Unmanned Aircraft Systems (UAS) are considered the stepping stone for the integration of civil unmanned vehicles in the National Airspace System (NAS) because of their low cost and risk. Such systems are aimed at a variety of applications including search and rescue, surveillance, communications, traffic monitoring and inspection of buildings, power lines and bridges. Amidst these systems, small helicopters play an important role because of their capability to hold a position, to maneuver in tight spaces and to take off and land from virtually anywhere. Nevertheless civil adoption of such systems is minimal, mostly because of regulatory problems that in turn are due to safety concerns. This dissertation examines the risk to safety imposed by UAS in general and small helicopters in particular, focusing on accidents resulting in a ground impact. To improve the performance of small helicopters in this area, the use of autonomous autorotation is proposed. This research goes beyond previous work in the area of autonomous autorotation by developing an on-line, model-based, real-time controller that is capable of handling constraints and different cost functions. The approach selected is based on a non-linear model-predictive controller, that is augmented by a neural network to improve the speed of the non-linear optimization. The immediate benefit of this controller is that a class of failures that would otherwise result in an uncontrolled crash and possible injuries or fatalities can now be accommodated. Furthermore besides simply landing the helicopter, the controller is also capable of minimizing the risk of serious injury to people in the area. This is accomplished by minimizing the kinetic energy during the last phase of the descent. The presented research is designed to benefit the entire UAS community as well as the public, by allowing for safer UAS operations, which in turn also allow faster and less expensive integration of UAS in the NAS.

  9. Nonlinear Feedforward Control for Wind Disturbance Rejection on Autonomous Helicopter

    DEFF Research Database (Denmark)

    Bisgaard, Morten; la Cour-Harbo, Anders; A. Danapalasingam, Kumeresan

    This paper presents the design and verification of a model based nonlinear feedforward controller for wind disturbance rejection on autonomous helicopters. The feedforward control is based on a helicopter model that is derived using a number of carefully chosen simplifications to make it suitable...

  10. Square tracking sensor for autonomous helicopter hover stabilization

    Science.gov (United States)

    Oertel, Carl-Henrik

    1995-06-01

    Sensors for synthetic vision are needed to extend the mission profiles of helicopters. A special task for various applications is the autonomous position hold of a helicopter above a ground fixed or moving target. As a proof of concept for a general synthetic vision solution a restricted machine vision system, which is capable of locating and tracking a special target, was developed by the Institute of Flight Mechanics of Deutsche Forschungsanstalt fur Luft- und Raumfahrt e.V. (i.e., German Aerospace Research Establishment). This sensor, which is specialized to detect and track a square, was integrated in the fly-by-wire helicopter ATTHeS (i.e., Advanced Technology Testing Helicopter System). An existing model following controller for the forward flight condition was adapted for the hover and low speed requirements of the flight vehicle. The special target, a black square with a length of one meter, was mounted on top of a car. Flight tests demonstrated the automatic stabilization of the helicopter above the moving car by synthetic vision.

  11. Underslung Payload Tension Control from an Autonomous Unmanned Helicopter

    OpenAIRE

    McCabe, Brian John

    2012-01-01

    A tension control algorithm for the deployment of a unmanned ground vehicle from an autonomous helicopter is designed and tested in this thesis. The physical hardware which the controller will run on is detailed. The plant model and underlying controllers are derived and modeled. The tension controller algorithm is selected, derived, and modeled. The parameters of the tension controller are chosen and simulations are run with the chosen parameters. The tension control algorithm...

  12. Merged Vision and GPS Control of a Semi-Autonomous, Small Helicopter

    Science.gov (United States)

    Rock, Stephen M.

    1999-01-01

    This final report documents the activities performed during the research period from April 1, 1996 to September 30, 1997. It contains three papers: Carrier Phase GPS and Computer Vision for Control of an Autonomous Helicopter; A Contestant in the 1997 International Aerospace Robotics Laboratory Stanford University; and Combined CDGPS and Vision-Based Control of a Small Autonomous Helicopter.

  13. Autonomous formation flight of helicopters: Model predictive control approach

    Science.gov (United States)

    Chung, Hoam

    Formation flight is the primary movement technique for teams of helicopters. However, the potential for accidents is greatly increased when helicopter teams are required to fly in tight formations and under harsh conditions. This dissertation proposes that the automation of helicopter formations is a realistic solution capable of alleviating risks. Helicopter formation flight operations in battlefield situations are highly dynamic and dangerous, and, therefore, we maintain that both a high-level formation management system and a distributed coordinated control algorithm should be implemented to help ensure safe formations. The starting point for safe autonomous formation flights is to design a distributed control law attenuating external disturbances coming into a formation, so that each vehicle can safely maintain sufficient clearance between it and all other vehicles. While conventional methods are limited to homogeneous formations, our decentralized model predictive control (MPC) approach allows for heterogeneity in a formation. In order to avoid the conservative nature inherent in distributed MPC algorithms, we begin by designing a stable MPC for individual vehicles, and then introducing carefully designed inter-agent coupling terms in a performance index. Thus the proposed algorithm works in a decentralized manner, and can be applied to the problem of helicopter formations comprised of heterogenous vehicles. Individual vehicles in a team may be confronted by various emerging situations that will require the capability for in-flight reconfiguration. We propose the concept of a formation manager to manage separation, join, and synchronization of flight course changes. The formation manager accepts an operator's commands, information from neighboring vehicles, and its own vehicle states. Inside the formation manager, there are multiple modes and complex mode switchings represented as a finite state machine (FSM). Based on the current mode and collected

  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. Helicopter Rotor Blade Monitoring using Autonomous Wireless Sensor Network

    OpenAIRE

    Sanchez Ramirez, Andrea; Loendersloot, Richard; Tinga, Tiedo; Basu, B

    2013-01-01

    The advancement on Wireless Sensor Networks for vibration monitoring presents important possibilities for helicopter rotor health and usage monitoring. While main rotor blades account for the main source of lift for helicopters, rotor induced vibration establishes an important source for understanding the rotor performance and blade condition. A discussion on the dual character of blades as rotating structures results in two different interrogation strategies for external and internal dynamic...

  16. Development of an Autonomous Flight Control System for Small Size Unmanned Helicopter Based on Dynamical Model

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    It is devoted to the development of an autonomous flight control system for small size unmanned helicopter based on dynamical model. At first, the mathematical model of a small size helicopter is described. After that simple but effective MTCV control algorithm was proposed. The whole flight control algorithm is composed of two parts:orientation controller based on the model for rotation dynamics and a robust position controller for a double integrator. The MTCV block is also used to achieve translation velocity control. To demonstrate the performance of the presented algorithm, simulation results and results achieved in real flight experiments were presented.

  17. AUTONOMOUS UNMANNED HELICOPTER SYSTEM FOR REMOTE SENSING MISSIONS IN UNKNOWN ENVIRONMENTS

    Directory of Open Access Journals (Sweden)

    T. Merz

    2012-09-01

    Full Text Available This paper presents the design of an autonomous unmanned helicopter system for low-altitude remote sensing. The proposed concepts and methods are generic and not limited to a specific helicopter. The development was driven by the need for a dependable, modular, and affordable system with sufficient payload capacity suitable for both research and real-world deployment. The helicopter can be safely operated without a backup pilot in a contained area beyond visual range. This enables data collection in inaccessible or dangerous areas. Thanks to its terrain following and obstacle avoidance capability, the system does not require a priori information about terrain elevation and obstacles. Missions are specified in state diagrams and flight plans. We present performance characteristics of our system and show results of its deployment in real-world scenarios. We have successfully completed several dozen infrastructure inspection missions and crop monitoring missions facilitating plant phenomics studies.

  18. 3D Vision Based Landing Control of a Small Scale Autonomous Helicopter

    Directory of Open Access Journals (Sweden)

    Zhenyu Yu

    2008-11-01

    Full Text Available Autonomous landing is a challenging but important task for Unmanned Aerial Vehicles (UAV to achieve high level of autonomy. The fundamental requirement for landing is the knowledge of the height above the ground, and a properly designed controller to govern the process. This paper presents our research results in the study of landing an autonomous helicopter. The abovetheground height sensing is based on a 3D vision system. We have designed a simple planefitting method for estimating the height over the ground. The method enables vibration free measurement with the camera rigidly attached on the helicopter without using complicated gimbal or active vision mechanism. The estimated height is used by the landing control loop. Considering the ground effect during landing, we have proposed a twostage landing procedure. Two controllers are designed for the two landing stages respectively. The sensing approach and control strategy has been verified in field flight test and has demonstrated satisfactory performance.

  19. Real-time path planning and autonomous control for helicopter autorotation

    Science.gov (United States)

    Yomchinda, Thanan

    Autorotation is a descending maneuver that can be used to recover helicopters in the event of total loss of engine power; however it is an extremely difficult and complex maneuver. The objective of this work is to develop a real-time system which provides full autonomous control for autorotation landing of helicopters. The work includes the development of an autorotation path planning method and integration of the path planner with a primary flight control system. The trajectory is divided into three parts: entry, descent and flare. Three different optimization algorithms are used to generate trajectories for each of these segments. The primary flight control is designed using a linear dynamic inversion control scheme, and a path following control law is developed to track the autorotation trajectories. Details of the path planning algorithm, trajectory following control law, and autonomous autorotation system implementation are presented. The integrated system is demonstrated in real-time high fidelity simulations. Results indicate feasibility of the capability of the algorithms to operate in real-time and of the integrated systems ability to provide safe autorotation landings. Preliminary simulations of autonomous autorotation on a small UAV are presented which will lead to a final hardware demonstration of the algorithms.

  20. Terrain and Radiation Mapping in Post-Disaster Environments Using an Autonomous Helicopter

    Directory of Open Access Journals (Sweden)

    Kevin Kochersberger

    2012-07-01

    Full Text Available Recent events have highlighted the need for unmanned remote sensing in dangerous areas, particularly where structures have collapsed or explosions have occurred, to limit hazards to first responders and increase their efficiency in planning response operations. In the case of the Fukushima nuclear reactor explosion, an unmanned helicopter capable of obtaining overhead images, gathering radiation measurements, and mapping both the structural and radiation content of the environment would have given the response team invaluable data early in the disaster, thereby allowing them to understand the extent of the damage and areas where dangers to personnel existed. With this motivation, the Unmanned Systems Lab at Virginia Tech has developed a remote sensing system for radiation detection and aerial imaging using a 90 kg autonomous helicopter and sensing payloads for the radiation detection and imaging operations. The radiation payload, which is the sensor of focus in this paper, consists of a scintillating type detector with associated software and novel search algorithms to rapidly and effectively map and locate sources of high radiation intensity. By incorporating this sensing technology into an unmanned aerial vehicle system, crucial situational awareness can be gathered about a post-disaster environment and response efforts can be expedited. This paper details the radiation mapping and localization capabilities of this system as well as the testing of the various search algorithms using simulated radiation data. The various components of the system have been flight tested over a several-year period and a new production flight platform has been built to enhance reliability and maintainability. The new system is based on the Aeroscout B1-100 helicopter platform, which has a one-hour flight endurance and uses a COFDM radio system that gives the helicopter an effective range of 7 km.

  1. Aeromagnetic survey using an unmanned autonomous helicopter over Tarumae Volcano, northern Japan

    Science.gov (United States)

    Hashimoto, Takeshi; Koyama, Takao; Kaneko, Takayuki; Ohminato, Takao; Yanagisawa, Takatoshi; Yoshimoto, Mitsuhiro; Suzuki, Eiichi

    2014-09-01

    Unmanned aerial vehicles (UAVs) have recently received attention in various research fields for their ability to perform measurements, surveillance, and operations in hazardous areas. Our application is volcano surveillance, in which we used an unmanned autonomous helicopter to conduct a dense low-altitude aeromagnetic survey over Tarumae Volcano, northern Japan. In autonomous flight, we demonstrated positioning control with an accuracy of ~10 m, which would be difficult for an ordinary crewed vehicle. In contrast to ground-based magnetic measurement, which is highly susceptible to local anomalies, the field gradient in the air with a terrain clearance of 100 to 300 m was fairly small at 1 nT/m. This result suggests that detection of temporal changes of an order of 10 nT may be feasible through a direct comparison of magnetic data between separate surveys by means of such a system, rather than that obtained by upward continuation to a common reduction surface. We assessed the temporal magnetic changes in the air, assuming the same remagnetising source within the volcano that was recently determined through ground surveys. We conclude that these expected temporal changes would reach a detection level in several years through a future survey in the air with the same autonomous vehicle.

  2. A remote radiation monitoring system using an autonomous unmanned helicopter for nuclear emergencies

    International Nuclear Information System (INIS)

    A feasibility study of a remote radiation monitoring system using a autonomous unmanned helicopter, mounted with a radiation detector and three CCD cameras, was carried out for surveying the dose-rate distribution of environmental radiation. This system can fly to destinations and return under automatic operation, measure radiation data during flight, and immediately transmit the data, including images, to a monitoring station on the ground. It is also possible to monitor the data on a map on a computer display in real time. Flight tests confirmed that the system can measure fluctuations of dose-rate distribution on the ground, and could be used for radiation monitoring in case of a nuclear emergency. (author)

  3. The Effectiveness of Pole Placement Method in Control System Design for an Autonomous Helicopter Model in Hovering Flight

    Directory of Open Access Journals (Sweden)

    Abas Ab. Wahab

    2009-12-01

    Full Text Available This paper presents the results of attitude, velocity, heave and yaw controller design for an autonomous model scaled helicopter using identified model of vehicle dynamic from parameterized state-space model with quasi-steady attitude dynamic approximation (6 Degree of Freedom model. Multivariable state-space control methodology such as pole placement was used to design the linear state-space feedback for the stabilization of helicopter because of its simple controller architecture. The design specification for controller design was selected according to Military Handling Qualities Specification ADS-33C. Results indicate that acceptable controller can be designed using pole placement method with quasi-steady attitude approximation and it has been shown that the controller design was compliance with design criteria of hover requirement in ADS-33C.

  4. Helicopter Field Testing of NASA's Autonomous Landing and Hazard Avoidance Technology (ALHAT) System fully Integrated with the Morpheus Vertical Test Bed Avionics

    Science.gov (United States)

    Epp, Chirold D.; Robertson, Edward A.; Ruthishauser, David K.

    2013-01-01

    The Autonomous Landing and Hazard Avoidance Technology (ALHAT) Project was chartered to develop and mature to a Technology Readiness Level (TRL) of six an autonomous system combining guidance, navigation and control with real-time terrain sensing and recognition functions for crewed, cargo, and robotic planetary landing vehicles. The ALHAT System must be capable of identifying and avoiding surface hazards to enable a safe and accurate landing to within tens of meters of designated and certified landing sites anywhere on a planetary surface under any lighting conditions. This is accomplished with the core sensing functions of the ALHAT system: Terrain Relative Navigation (TRN), Hazard Detection and Avoidance (HDA), and Hazard Relative Navigation (HRN). The NASA plan for the ALHAT technology is to perform the TRL6 closed loop demonstration on the Morpheus Vertical Test Bed (VTB). The first Morpheus vehicle was lost in August of 2012 during free-flight testing at Kennedy Space Center (KSC), so the decision was made to perform a helicopter test of the integrated ALHAT System with the Morpheus avionics over the ALHAT planetary hazard field at KSC. The KSC helicopter tests included flight profiles approximating planetary approaches, with the entire ALHAT system interfaced with all appropriate Morpheus subsystems and operated in real-time. During these helicopter flights, the ALHAT system imaged the simulated lunar terrain constructed in FY2012 to support ALHAT/Morpheus testing at KSC. To the best of our knowledge, this represents the highest fidelity testing of a system of this kind to date. During this helicopter testing, two new Morpheus landers were under construction at the Johnson Space Center to support the objective of an integrated ALHAT/Morpheus free-flight demonstration. This paper provides an overview of this helicopter flight test activity, including results and lessons learned, and also provides an overview of recent integrated testing of ALHAT on the second

  5. Helicopter flight test of 3D imaging flash LIDAR technology for safe, autonomous, and precise planetary landing

    Science.gov (United States)

    Roback, Vincent; Bulyshev, Alexander; Amzajerdian, Farzin; Reisse, Robert

    2013-05-01

    Two flash lidars, integrated from a number of cutting-edge components from industry and NASA, are lab characterized and flight tested for determination of maximum operational range under the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project (in its fourth development and field test cycle) which is seeking to develop a guidance, navigation, and control (GNC) and sensing system based on lidar technology capable of enabling safe, precise crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The flash lidars incorporate pioneering 3-D imaging cameras based on Indium-Gallium-Arsenide Avalanche Photo Diode (InGaAs APD) and novel micro-electronic technology for a 128 x 128 pixel array operating at 30 Hz, high pulse-energy 1.06 μm Nd:YAG lasers, and high performance transmitter and receiver fixed and zoom optics. The two flash lidars are characterized on the NASA-Langley Research Center (LaRC) Sensor Test Range, integrated with other portions of the ALHAT GNC system from partner organizations into an instrument pod at NASA-JPL, integrated onto an Erickson Aircrane Helicopter at NASA-Dryden, and flight tested at the Edwards AFB Rogers dry lakebed over a field of humanmade geometric hazards during the summer of 2010. Results show that the maximum operational range goal of 1 km is met and exceeded up to a value of 1.2 km. In addition, calibrated 3-D images of several hazards are acquired in realtime for later reconstruction into Digital Elevation Maps (DEM's).

  6. Helicopter Flight Test of 3-D Imaging Flash LIDAR Technology for Safe, Autonomous, and Precise Planetary Landing

    Science.gov (United States)

    Roback, Vincent; Bulyshev, Alexander; Amzajerdian, Farzin; Reisse, Robert

    2013-01-01

    Two flash lidars, integrated from a number of cutting-edge components from industry and NASA, are lab characterized and flight tested for determination of maximum operational range under the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project (in its fourth development and field test cycle) which is seeking to develop a guidance, navigation, and control (GN&C) and sensing system based on lidar technology capable of enabling safe, precise crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The flash lidars incorporate pioneering 3-D imaging cameras based on Indium-Gallium-Arsenide Avalanche Photo Diode (InGaAs APD) and novel micro-electronic technology for a 128 x 128 pixel array operating at 30 Hz, high pulse-energy 1.06 micrometer Nd:YAG lasers, and high performance transmitter and receiver fixed and zoom optics. The two flash lidars are characterized on the NASA-Langley Research Center (LaRC) Sensor Test Range, integrated with other portions of the ALHAT GN&C system from partner organizations into an instrument pod at NASA-JPL, integrated onto an Erickson Aircrane Helicopter at NASA-Dryden, and flight tested at the Edwards AFB Rogers dry lakebed over a field of human-made geometric hazards during the summer of 2010. Results show that the maximum operational range goal of 1 km is met and exceeded up to a value of 1.2 km. In addition, calibrated 3-D images of several hazards are acquired in real-time for later reconstruction into Digital Elevation Maps (DEM's).

  7. Robotic Helicopter Surveying (MAS 13)

    OpenAIRE

    Srikanth Saripalli; Jonathan Kelly; Sukhatme, Gaurav S.

    2006-01-01

    We present a method for highly accurate surveying using an autonomous helicopter equipped with a downward looking camera. Given a location that needs to be mapped the helicopter creates accurate aerial maps by combining visual data with inertial and GPS data. We present initial results that show maps of Lake Fulmor using the helicopter. These maps were created manually but they demonstrate the method used.

  8. Pheno-Copter: A Low-Altitude, Autonomous Remote-Sensing Robotic Helicopter for High-Throughput Field-Based Phenotyping

    Directory of Open Access Journals (Sweden)

    Scott C. Chapman

    2014-06-01

    Full Text Available Plant breeding trials are extensive (100s to 1000s of plots and are difficult and expensive to monitor by conventional means, especially where measurements are time-sensitive. For example, in a land-based measure of canopy temperature (hand-held infrared thermometer at two to 10 plots per minute, the atmospheric conditions may change greatly during the time of measurement. Such sensors measure small spot samples (2 to 50 cm2, whereas image-based methods allow the sampling of entire plots (2 to 30 m2. A higher aerial position allows the rapid measurement of large numbers of plots if the altitude is low (10 to 40 m and the flight control is sufficiently precise to collect high-resolution images. This paper outlines the implementation of a customized robotic helicopter (gas-powered, 1.78-m rotor diameter with autonomous flight control and software to plan flights over experiments that were 0.5 to 3 ha in area and, then, to extract, straighten and characterize multiple experimental field plots from images taken by three cameras. With a capacity to carry 1.5 kg for 30 min or 1.1 kg for 60 min, the system successfully completed >150 flights for a total duration of 40 h. Example applications presented here are estimations of the variation in: ground cover in sorghum (early season; canopy temperature in sugarcane (mid-season; and three-dimensional measures of crop lodging in wheat (late season. Together with this hardware platform, improved software to automate the production of ortho-mosaics and digital elevation models and to extract plot data would further benefit the development of high-throughput field-based phenotyping systems.

  9. Helicopter-borne laser autonomous positioning of buried pipeline%机载激光对埋地管道的自主定位

    Institute of Scientific and Technical Information of China (English)

    刘海芳; 王瑞; 钟诗胜; 刘克强

    2011-01-01

    为实现用机载激光对埋地天然气管道泄漏进行遥感检测,提出了机载激光自主定位管道的定位测量方法,利用机载GPS和惯性姿态测量系统得到载机的位置和姿态,结合已知的埋地管道地理位置信息,采用解析几何中的点法式求出激光对管道的自主定位点;然后利用坐标转换求出激光束在载机坐标系中的方位角和俯仰角,通过机械机构驱动激光完成对管道的引导定位.利用自行研制的激光夹持对准机构进行了地面定点实验,结果显示,地面定位最大误差为8.4m,平均定位误差<6.9 m;若进一步提高载机姿态、位置传感器精度及执行机构精度,激光对管道的引导定位误差会更小.结果表明本文所阐述的激光对埋地管道自主定位算法可用于机载激光对埋地天然气管道的遥感检测.%To realize the remote detection of the leak of a buried natural gas pipeline by an airborne laser, a helicopter-borne laser autonomous positioning method for the buried natural gas pipeline was presented. Based on the position and attitude of the carrier aircraft obtained by an airborne GPS and an inertial attitude measurement system, the laser autonomous positioning point of the pipeline was obtained based on the known location information and by the space vector method. Furthermore,the azimuth and pitch angles of the airborne laser were solved through the coordinate transformation. Finally, driven by the mechanism, the laser-guiding positioning of the pipeline was fulfilled. With application of the laser clamping alignment mechanism independently developed by ourselves, the ground point-fixed experiment proves that the proposed algorithm can offer the accuracy of the ground positioning by 6. 9 m,and it will be more accurate when the precision of the carrier aircraft attitude and the position sensor is further improved. Experiments demonstrate that the algorithm is suitable for the remote detection of the

  10. MMW radar enhanced vision systems: the Helicopter Autonomous Landing System (HALS) and Radar-Enhanced Vision System (REVS) are rotary and fixed wing enhanced flight vision systems that enable safe flight operations in degraded visual environments

    Science.gov (United States)

    Cross, Jack; Schneider, John; Cariani, Pete

    2013-05-01

    Sierra Nevada Corporation (SNC) has developed rotary and fixed wing millimeter wave radar enhanced vision systems. The Helicopter Autonomous Landing System (HALS) is a rotary-wing enhanced vision system that enables multi-ship landing, takeoff, and enroute flight in Degraded Visual Environments (DVE). HALS has been successfully flight tested in a variety of scenarios, from brown-out DVE landings, to enroute flight over mountainous terrain, to wire/cable detection during low-level flight. The Radar Enhanced Vision Systems (REVS) is a fixed-wing Enhanced Flight Vision System (EFVS) undergoing prototype development testing. Both systems are based on a fast-scanning, threedimensional 94 GHz radar that produces real-time terrain and obstacle imagery. The radar imagery is fused with synthetic imagery of the surrounding terrain to form a long-range, wide field-of-view display. A symbology overlay is added to provide aircraft state information and, for HALS, approach and landing command guidance cuing. The combination of see-through imagery and symbology provides the key information a pilot needs to perform safe flight operations in DVE conditions. This paper discusses the HALS and REVS systems and technology, presents imagery, and summarizes the recent flight test results.

  11. Skycrane Helicopter

    Science.gov (United States)

    1972-01-01

    The Sikorsky S-64 Skycrane helicopter, which saw service with the U.S.Army as the CH-54 Tarhe, flew at Langley in its later version, the CH-54B. The 'Crane' was used in studies into the handling of large helicopters, and as such sported various loads attached to the airframe. The Army retired its Skycranes in the 1970s and they were completely removed from military service in the 1980s. Ex-military Skycranes entered commercial service, where they are used in various heavy-lift roles, including the lumber industry. The U.S. military preferred a heavy-lift aircraft that also had a cabin capable of carrying cargo and troops.

  12. Evaluating SLAM algorithms for Autonomous Helicopters

    OpenAIRE

    Skoglund, Martin

    2008-01-01

    Navigation with unmanned aerial vehicles (UAVs) requires good knowledge of the current position and other states. A UAV navigation system often uses GPS and inertial sensors in a state estimation solution. If the GPS signal is lost or corrupted state estimation must still be possible and this is where simultaneous localization and mapping (SLAM) provides a solution. SLAM considers the problem of incrementally building a consistent map of a previously unknown environment and simultaneously loc...

  13. Small Business Innovations (Helicopters)

    Science.gov (United States)

    1992-01-01

    The amount of engine power required for a helicopter to hover is an important, but difficult, consideration in helicopter design. The EHPIC program model produces converged, freely distorted wake geometries that generate accurate analysis of wake-induced downwash, allowing good predictions of rotor thrust and power requirements. Continuum Dynamics, Inc., the Small Business Innovation Research (SBIR) company that developed EHPIC, also produces RotorCRAFT, a program for analysis of aerodynamic loading of helicopter blades in forward flight. Both helicopter codes have been licensed to commercial manufacturers.

  14. Model Reference Sliding Mode Control of Small Helicopter X.R.B based on Vision

    OpenAIRE

    Wei Wang; Kenzo Nonami; Yuta Ohira

    2008-01-01

    This paper presents autonomous control for indoor small helicopter X.R.B. In case of natural disaster like earthquake, a MAV (Micro Air Vehicle) which can fly autonomously will be very effective for surveying the site and environment in dangerous area or narrow space, where human cannot access safely. In addition, it will be helpful to prevent secondary disaster. This paper describes vision based autonomous hovering control, guidance control for X.R.B by model reference sliding mode control.

  15. 78 FR 9793 - Airworthiness Directives; Bell Helicopter Textron Helicopters

    Science.gov (United States)

    2013-02-12

    ... Model 204B, 205A, 205A-1, 205B and 210 helicopters with certain part-numbered main rotor hub inboard... a main rotor blade, and subsequent loss of helicopter control. DATES: This AD becomes effective... helicopters, are susceptible to the same type of cracking because they are of similar design and...

  16. Power Efficient Video Communication for Mini Helicopter

    OpenAIRE

    Ingvaldsen, Ola Naalsund

    2010-01-01

    In this thesis, a video communication system for use in a mini helicopter is reviewed. The transmitter is located in a small battery powered mini helicopter, weighing about 15 grams, and the receiver is the helicopter's remote control. The operator controls the helicopter only based on the video feed sent from the helicopter, hence it is critical that the delay is kept to a minimum. Due to the helicopter's small size, the energy available is very limited, and both coding and transmission shou...

  17. Advanced Airfoils Boost Helicopter Performance

    Science.gov (United States)

    2007-01-01

    Carson Helicopters Inc. licensed the Langley RC4 series of airfoils in 1993 to develop a replacement main rotor blade for their Sikorsky S-61 helicopters. The company's fleet of S-61 helicopters has been rebuilt to include Langley's patented airfoil design, and the helicopters are now able to carry heavier loads and fly faster and farther, and the main rotor blades have twice the previous service life. In aerial firefighting, the performance-boosting airfoils have helped the U.S. Department of Agriculture's Forest Service control the spread of wildfires. In 2003, Carson Helicopters signed a contract with Ducommun AeroStructures Inc., to manufacture the composite blades for Carson Helicopters to sell

  18. Development of helicopter attitude axes controlled hover flight without pilot assistance and vehicle crashes

    Science.gov (United States)

    Simon, Miguel

    testing any one or combination of the following attitude axes controlled flight: (1) pitch, (2) roll and (3) yaw. The subsequent development of a novel method to decouple, stabilize and teach the helicopter hover flight is a primary contribution of this thesis. The novel method included the development of a non-linear modeling technique for linearizing the RPM state equation dynamics so that a simple but accurate transfer function is derivable between the "available torque of the engine" and RPM. Specifically, the main rotor and tail rotor torques are modeled accurately with a bias term plus a nonlinear term involving the product of RPM squared times the main rotor blade pitch angle raised to the three-halves power. Application of this non-linear modeling technique resulted in a simple, representative and accurate transfer function model of the open-loop plant for the entire helicopter system so that all the feedback control laws for autonomous flight purposes could be derived easily using classical control theory. This is one of the contributions of this dissertation work. After discussing the integration of hardware and software elements of our helicopter research test bed system, we perform a number of experiments and tests using the two specially built test stands. Feedback gains are derived for controlling the following: (1) engine throttle to maintain prescribed main rotor angular speed, (2) main rotor collective pitch to maintain constant elevation, (3) longitudinal cyclic pitch to maintain prescribed pitch angle, (4) lateral cyclic pitch to maintain prescribed roll angle, and (5) yaw axis to maintain prescribed compass direction. (Abstract shortened by UMI.)

  19. Agent, autonomous

    OpenAIRE

    Luciani, Annie

    2007-01-01

    The expression autonomous agents, widely used in virtual reality, computer graphics, artificial intelligence and artificial life, corresponds to the simulation of autonomous creatures, virtual (i.e. totally computed by a program), or embodied in a physical envelope, as done in autonomous robots.

  20. 78 FR 35773 - Airworthiness Directives; MD Helicopters, Inc. (MDHI), Helicopters

    Science.gov (United States)

    2013-06-14

    ... the MDHI Model MD900 helicopters with certain main rotor blade (MRB) retention bolts (bolts) installed... MD 900 helicopters with a main rotor blade retention bolt (bolt), part number (P/N) 900R3100001-103... exist or develop on other products of the same type design. Related Service Information We have...

  1. Identification, control and visually-guided behavior for a model helicopter

    Science.gov (United States)

    Saripalli, Srikanth

    Research on unmanned aerial vehicles is motivated by applications where human intervention is impossible, risky or expensive e.g. hazardous material recovery, traffic monitoring, disaster relief support, military operations etc. Due to its vertical take-off, landing and hover capabilities, a helicopter is an attractive platform for such applications. There are significant challenges to building an autonomous robotic helicopter - these span the areas of system identification, low-level control, state estimation, and planning. Towards the goal of fully-autonomous helicopters this thesis makes the following contributions. A continuous-discrete extended Kalman filter has been developed that combines inertial data with GPS and compass data to provide estimates of the 6DOF state of the helicopter. Using this filter a model for the helicopter has been identified based on frequency response techniques. The model has been validated in flight tests on a small helicopter testbed (1.6 m rotor diameter) at speeds upto 5 m/s. Based on evidence from this model a decoupled low-level controller has been developed which is embedded in a control architecture suitable for visually-guided navigation. As a novel application, we show how such a controller can be used to perform trajectory following on the helicopter where the desired trajectories are typical spacecraft landing trajectories, and the only controls available are thrusters. This in effect, produces a low-cost testbed for testing spacecraft landing and hazard avoidance on a planetary surface. Finally, we develop and extensively experimentally characterize algorithms for vision-based autonomous landing, object tracking, and sensor deployment.

  2. A Primer on Autonomous Aerial Vehicle Design

    Science.gov (United States)

    Coppejans, Hugo H. G.; Myburgh, Herman C.

    2015-01-01

    There is a large amount of research currently being done on autonomous micro-aerial vehicles (MAV), such as quadrotor helicopters or quadcopters. The ability to create a working autonomous MAV depends mainly on integrating a simultaneous localization and mapping (SLAM) solution with the rest of the system. This paper provides an introduction for creating an autonomous MAV for enclosed environments, aimed at students and professionals alike. The standard autonomous system and MAV automation are discussed, while we focus on the core concepts of SLAM systems and trajectory planning algorithms. The advantages and disadvantages of using remote processing are evaluated, and recommendations are made regarding the viability of on-board processing. Recommendations are made regarding best practices to serve as a guideline for aspirant MAV designers. PMID:26633410

  3. A Primer on Autonomous Aerial Vehicle Design

    Directory of Open Access Journals (Sweden)

    Hugo H. G. Coppejans

    2015-12-01

    Full Text Available There is a large amount of research currently being done on autonomous micro-aerial vehicles (MAV, such as quadrotor helicopters or quadcopters. The ability to create a working autonomous MAV depends mainly on integrating a simultaneous localization and mapping (SLAM solution with the rest of the system. This paper provides an introduction for creating an autonomous MAV for enclosed environments, aimed at students and professionals alike. The standard autonomous system and MAV automation are discussed, while we focus on the core concepts of SLAM systems and trajectory planning algorithms. The advantages and disadvantages of using remote processing are evaluated, and recommendations are made regarding the viability of on-board processing. Recommendations are made regarding best practices to serve as a guideline for aspirant MAV designers.

  4. A Primer on Autonomous Aerial Vehicle Design.

    Science.gov (United States)

    Coppejans, Hugo H G; Myburgh, Herman C

    2015-01-01

    There is a large amount of research currently being done on autonomous micro-aerial vehicles (MAV), such as quadrotor helicopters or quadcopters. The ability to create a working autonomous MAV depends mainly on integrating a simultaneous localization and mapping (SLAM) solution with the rest of the system. This paper provides an introduction for creating an autonomous MAV for enclosed environments, aimed at students and professionals alike. The standard autonomous system and MAV automation are discussed, while we focus on the core concepts of SLAM systems and trajectory planning algorithms. The advantages and disadvantages of using remote processing are evaluated, and recommendations are made regarding the viability of on-board processing. Recommendations are made regarding best practices to serve as a guideline for aspirant MAV designers. PMID:26633410

  5. Helicopter Rotor Antenna

    Science.gov (United States)

    Pogorzelski, Ronald J.; Cable, Vaughn P.

    2001-01-01

    This effort was directed toward demonstration of the efficacy of a concept for mitigation of the rotor blade modulation problem in helicopter communications. An antenna is envisioned with radiating elements mounted on the rotor and rotating with it. The rf signals are coupled to the radio stationary with respect to the airframe via a coupler of unique design. The coupler has an rf cavity within which a mode is established and the field distribution of this mode is sampled by probes rotating with the radiating elements. In this manner the radiated pattern is "despun" with respect to the rotor. Theoretical analysis has indicated that this arrangement will be less susceptible to rotor blade modulation that would be a conventional fixed mounted antenna. A small coupler operating at S-band was designed, fabricated, and mounted on a mockup representative of a helicopter body. A small electric motor was installed to rotate the rotor portion of the coupler along with a set of radiating elements during testing. This test article was be evaluated using the JPL Mesa Antenna Measurement Facility to establish its ability to mitigate rotor blade modulation. It was found that indeed such a coupler will result in a despun pattern and that such a pattern can be effective in mitigation of rotor blade modulation.

  6. Modeling, Control and Coordination of Helicopter Systems

    CERN Document Server

    Ren, Beibei; Chen, Chang; Fua, Cheng-Heng; Lee, Tong Heng

    2012-01-01

    Modeling, Control and Coordination of Helicopter Systems provides a comprehensive treatment of helicopter systems, ranging from related nonlinear flight dynamic modeling and stability analysis to advanced control design for single helicopter systems, and also covers issues related to the coordination and formation control of multiple helicopter systems to achieve high performance tasks. Ensuring stability in helicopter flight is a challenging problem for nonlinear control design and development. This book is a valuable reference on modeling, control and coordination of helicopter systems,providing readers with practical solutions for the problems that still plague helicopter system design and implementation. Readers will gain a complete picture of helicopters at the systems level, as well as a better understanding of the technical intricacies involved. This book also: Presents a complete picture of modeling, control and coordination for helicopter systems Provides a modeling platform for a general class of ro...

  7. Vertebral pain in helicopter pilots

    Science.gov (United States)

    Auffret, R.; Delahaye, R. P.; Metges, P. J.; VICENS

    1980-01-01

    Pathological forms of spinal pain engendered by piloting helicopters were clinically studied. Lumbalgia and pathology of the dorsal and cervical spine are discussed along with their clinical and radiological signs and origins.

  8. Sandia Helicopter Acoustic Detector (SHAD)

    Science.gov (United States)

    Arlowe, H. D.

    1982-05-01

    The Sandia Helicopter Acoustic Detector was developed to provide a low cost alternative to radar for countering the helicopter threat at new DOE facilities. The main buildings of these new designs are generally hardened to provide significant delay to a helicopter borne adversary team. Under these circumstances the sensor is only required to detect helicopters that are in their final landing phase and at close range (less than 75 m). This short detection range allows the use of a fairly simple acoustic detection algorithm without making the system overly sensitive to wind noise, motor vehicles, and ventilation/heat exchange blowers. This work was sponsored by the Department of Energy/Office of Safeguards and Security as part of the overall Sandia Fixed Facility Physical Protection Program.

  9. Helicopter accident survivability.

    Science.gov (United States)

    Vyrnwy-Jones, P; Thornton, R

    1984-10-01

    Army Air Corps accident and fatality rates have now reached levels which compare favourably with data from other civilian and military sources. This improvement is the result of enhanced helicopter design and parallel progress in aircrew training. The introduction of new generations of turbine powered rotor craft has largely eliminated mechanical failure as the cause of accident. As a result 75% of Army Air Corps accidents are due to pilot error. This contribution is likely to increase in the future as the pilot's task is made more difficult by the incumberance of personal equipment. Methods whereby occupant protection and aircraft crashworthiness can be improved are reviewed and it is concluded that it would make sound economic sense to implement some of these well proven design features. PMID:6527344

  10. The evolution of helicopters

    Science.gov (United States)

    Chen, R.; Wen, C. Y.; Lorente, S.; Bejan, A.

    2016-07-01

    Here, we show that during their half-century history, helicopters have been evolving into geometrically similar architectures with surprisingly sharp correlations between dimensions, performance, and body size. For example, proportionalities emerge between body size, engine size, and the fuel load. Furthermore, the engine efficiency increases with the engine size, and the propeller radius is roughly the same as the length scale of the whole body. These trends are in accord with the constructal law, which accounts for the engine efficiency trend and the proportionality between "motor" size and body size in animals and vehicles. These body-size effects are qualitatively the same as those uncovered earlier for the evolution of aircraft. The present study adds to this theoretical body of research the evolutionary design of all technologies [A. Bejan, The Physics of Life: The Evolution of Everything (St. Martin's Press, New York, 2016)].

  11. Human-Vehicle Interface for Semi-Autonomous Operation of Uninhabited Aero Vehicles

    Science.gov (United States)

    Jones, Henry L.; Frew, Eric W.; Woodley, Bruce R.; Rock, Stephen M.

    2001-01-01

    The robustness of autonomous robotic systems to unanticipated circumstances is typically insufficient for use in the field. The many skills of human user often fill this gap in robotic capability. To incorporate the human into the system, a useful interaction between man and machine must exist. This interaction should enable useful communication to be exchanged in a natural way between human and robot on a variety of levels. This report describes the current human-robot interaction for the Stanford HUMMINGBIRD autonomous helicopter. In particular, the report discusses the elements of the system that enable multiple levels of communication. An intelligent system agent manages the different inputs given to the helicopter. An advanced user interface gives the user and helicopter a method for exchanging useful information. Using this human-robot interaction, the HUMMINGBIRD has carried out various autonomous search, tracking, and retrieval missions.

  12. Variable-Tilt Helicopter Rotor Mast

    Science.gov (United States)

    Kelley, Henry L.

    1995-01-01

    Variable-tilt helicopter rotor mast proposed to improve helicopter performance and reduce vibration, especially at upper end of forward-speed range of helicopters. Achieved by use of universal coupling in main rotor mast or by tilting entire engine-and-transmission platform. Performance, energy efficiency, and safety enhanced.

  13. 46 CFR 108.653 - Helicopter facilities.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Helicopter facilities. 108.653 Section 108.653 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Equipment Markings and Instructions § 108.653 Helicopter facilities. (a) Each helicopter...

  14. 46 CFR 108.486 - Helicopter decks.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Helicopter decks. 108.486 Section 108.486 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems Fire Protection for Helicopter Facilities § 108.486 Helicopter decks....

  15. Investigating Flight with a Toy Helicopter

    Science.gov (United States)

    Liebl, Michael

    2010-01-01

    Flight fascinates people of all ages. Recent advances in battery technology have extended the capabilities of model airplanes and toy helicopters. For those who have never outgrown a childhood enthusiasm for the wonders of flight, it is possible to buy inexpensive, remotely controlled planes and helicopters. A toy helicopter offers an opportunity…

  16. Wavelet analysis of helicopter noise signal

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qiang; WANG Huaming; HU Zhangwei

    2002-01-01

    Helicopter noise features under typical flight condition were investigated based on wavelet transform. The contribution of blade-vortex interaction (BVI) to helicopter noise and low frequency oscillations beat was shown clearly from the detail of wavelet decomposition for helicopter noise signal.

  17. [Importance of helicopter rescue].

    Science.gov (United States)

    Hofer, G; Voelckel, W G

    2014-03-01

    Helicopter emergency medical service (HEMS) have become a main part of prehospital emergency medical services over the last 40 years. Recently, an ongoing discussion about financial shortage and personal shortcomings question the role of cost-intensive air rescue. Thus, the value of HEMS must be examined and discussed appropriately. Since the number of physician-staffed ground ambulances may decrease due to the limited availability of qualified physicians, HEMS may fill the gap. In addition patient transfer to specialized hospitals will require an increasing number of air transports in order to minimize prehospital time. The higher risk ratio for HEMS missions when compared with ground rescue requires a rigorous quality management system. When it comes to missions in remote and exposed areas, the scope of medical treatment must be adjusted to the individual situation. Medical competence is key in order to balance guideline compliant or maximal care versus optimal care characterized as a mission-specific, individualized emergency care concept. Although, medical decision making and treatment is typically based on the best scientific evidence, personal skills, competence, and the mission scenario will determine the scope of interventions suitable to improve outcome. Thus, the profile of requirements for the HEMS medical crew is high. PMID:24618925

  18. 77 FR 35306 - Airworthiness Directives; Bell Helicopter Textron, Inc. Helicopters

    Science.gov (United States)

    2012-06-13

    ... visibility, and subsequent loss of structural integrity and helicopter control. FAA's Determination We are... Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not affect intrastate aviation in Alaska... the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations...

  19. Helicopter Toy and Lift Estimation

    Science.gov (United States)

    Shakerin, Said

    2013-01-01

    A $1 plastic helicopter toy (called a Wacky Whirler) can be used to demonstrate lift. Students can make basic measurements of the toy, use reasonable assumptions and, with the lift formula, estimate the lift, and verify that it is sufficient to overcome the toy's weight. (Contains 1 figure.)

  20. Military display market segment: helicopters

    Science.gov (United States)

    Desjardins, Daniel D.; Hopper, Darrel G.

    2004-09-01

    The military display market is analyzed in terms of one of its segments: helicopter displays. Parameters requiring special consideration, to include luminance ranges, contrast ratio, viewing angles, and chromaticity coordinates, are examined. Performance requirements for rotary-wing displays relative to several premier applications are summarized. Display sizes having aggregate defense applications of 5,000 units or greater and having DoD applications across 10 or more platforms, are tabulated. The issue of size commonality is addressed where distribution of active area sizes across helicopter platforms, individually, in groups of two through nine, and ten or greater, is illustrated. Rotary-wing displays are also analyzed by technology, where total quantities of such displays are broken out into CRT, LCD, AMLCD, EM, LED, Incandescent, Plasma and TFEL percentages. Custom, versus Rugged commercial, versus commercial off-the-shelf designs are contrasted. High and low information content designs are identified. Displays for several high-profile military helicopter programs are discussed, to include both technical specifications and program history. The military display market study is summarized with breakouts for the helicopter market segment. Our defense-wide study as of March 2004 has documented 1,015,494 direct view and virtual image displays distributed across 1,181 display sizes and 503 weapon systems. Helicopter displays account for 67,472 displays (just 6.6% of DoD total) and comprise 83 sizes (7.0% of total DoD) in 76 platforms (15.1% of total DoD). Some 47.6% of these rotary-wing applications involve low information content displays comprising just a few characters in one color; however, as per fixed-wing aircraft, the predominant instantiation involves higher information content units capable of showing changeable graphics, color and video.

  1. Portable-Beacon Landing System for Helicopters

    Science.gov (United States)

    Davis, Thomas J.; Clary, George R.; Chisholm, John P.; Macdonald, Stanley L.

    1987-01-01

    Prototype beacon landing system (BLS) allows helicopters to make precise landings in all weather. BLS easily added to existing helicopter avionic equipment and readily deployed at remote sites. Small and light, system employs X-band radar and digital processing. Variety of beams pulsed sequentially by ground station after initial interrogation by weather radar of approaching helicopter. Airborne microprocessor processes pulses to determine glide slope, course deviation, and range.

  2. Poster presentation Sandia helicopter acoustic detector

    International Nuclear Information System (INIS)

    In reviewing the safeguards plans for several proposed fuel cycle facilities, the advantages of a short-range helicopter detector became apparent. The main buildings of these new designs are generally hardened so as to provide significant delay to a helicopter-borne adversary team. Under these circumstances the sensor is only required to detect helicopters which are in their final landing phase and at close range (less than 75 meters). This paper describes the Sandia detector, which is designed to only look at spectral lines between 20 and 40 Hz, and depends upon the harmonic content of the rotor pulses for detecting the lower rotor speed helicopters. 1 ref

  3. Control of helicopter rotorblade aerodynamics

    Science.gov (United States)

    Fabunmi, James A.

    1991-01-01

    The results of a feasibility study of a method for controlling the aerodynamics of helicopter rotorblades using stacks of piezoelectric ceramic plates are presented. A resonant mechanism is proposed for the amplification of the displacements produced by the stack. This motion is then converted into linear displacement for the actuation of the servoflap of the blades. A design which emulates the actuation of the servoflap on the Kaman SH-2F is used to demonstrate the fact that such a system can be designed to produce the necessary forces and velocities needed to control the aerodynamics of the rotorblades of such a helicopter. Estimates of the electrical power requirements are also presented. A Small Business Innovation Research (SBIR) Phase 2 Program is suggested, whereby a bench-top prototype of the device can be built and tested. A collaborative effort between AEDAR Corporation and Kaman Aerospace Corporation is anticipated for future effort on this project.

  4. Autonomous Search

    CERN Document Server

    Hamadi, Youssef; Saubion, Frédéric

    2012-01-01

    Decades of innovations in combinatorial problem solving have produced better and more complex algorithms. These new methods are better since they can solve larger problems and address new application domains. They are also more complex which means that they are hard to reproduce and often harder to fine-tune to the peculiarities of a given problem. This last point has created a paradox where efficient tools are out of reach of practitioners. Autonomous search (AS) represents a new research field defined to precisely address the above challenge. Its major strength and originality consist in the

  5. Pure Autonomic Failure

    Science.gov (United States)

    ... Drugs GARD Information Navigator FAQs About Rare Diseases Pure autonomic failure Title Other Names: Bradbury Eggleston syndrome; ... Categories: Nervous System Diseases ; RDCRN Summary Summary Listen Pure autonomic failure is characterized by generalized autonomic failure ...

  6. Degloving injury from a helicopter rotor strike.

    Science.gov (United States)

    Nelson, J M; Sawyer, M A

    1995-12-01

    The incidence of helicopter accidents has decreased, but lethality remains considerable. Rotor strikes are deadlier than crash-related injuries. We describe a degloving injury caused by a helicopter tail rotor strike managed with rapid resuscitation and early split-thickness skin grafting. PMID:8775394

  7. A study of helicopter interior noise reduction

    Science.gov (United States)

    Howlett, J. T.; Clevenson, S. A.

    1975-01-01

    The interior noise levels of existing helicopters are discussed along with an ongoing experimental program directed towards reducing these levels. Results of several noise and vibration measurements on Langley Research Center's Civil Helicopter Research Aircraft are presented, including measurements taken before and after installation of an acoustically-treated cabin. The predominant noise source in this helicopter is the first stage planetary gear-clash in the main gear box, both before and after installation of the acoustically treated cabin. Noise reductions of up to 20 db in some octave bands may be required in order to obtain interior noise levels comparable to commercial jet transports.

  8. Helicopter attempts tow of Liberty Bell 7

    Science.gov (United States)

    1961-01-01

    Marine helicopter appears to have Liberty Bell 7 in tow after Virgil I. Grissom's successful flight of 305 miles down the Atlantic Missile Range. Minutes after 'Gus' Grissom got out of the spacecraft, it sank.

  9. Tail Rotor Airfoils Stabilize Helicopters, Reduce Noise

    Science.gov (United States)

    2010-01-01

    Founded by former Ames Research Center engineer Jim Van Horn, Van Horn Aviation of Tempe, Arizona, built upon a Langley Research Center airfoil design to create a high performance aftermarket tail rotor for the popular Bell 206 helicopter. The highly durable rotor has a lifetime twice that of the original equipment manufacturer blade, reduces noise by 40 percent, and displays enhanced performance at high altitudes. These improvements benefit helicopter performance for law enforcement, military training, wildfire and pipeline patrols, and emergency medical services.

  10. An ambulance helicopter for emergency calls.

    OpenAIRE

    Sellwood, N

    1992-01-01

    The use of a helicopter as a primary response vehicle for the Cornwall Ambulance Service is presented. A brief analysis of the activities of the First Air Ambulance is described and an appraisal of its effects on the overall performance of the Service is given. Emphasis is given to patient acceptability and also to the flexibility of the helicopter in terms of its response to different situations. In conclusion, The Air Ambulance, as part of an integrated ambulance service, is an effective pr...

  11. 75 FR 69862 - Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters

    Science.gov (United States)

    2010-11-16

    ... exist or develop on other helicopters of the same type design. Therefore, this AD requires, within 4...-AD. Applicability: Model MD900 helicopters, with lower main rotor hub (hub), part number 900R2101008... the main rotor hub (hub) for a crack. If a crack is found, this AD requires, before further...

  12. 76 FR 41662 - Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters

    Science.gov (United States)

    2011-07-15

    ... helicopters of this same type design. AD Requirements This AD requires a visual inspection, and if necessary...) Inspect the main rotor lower hub assembly for a crack by following the specified portions of MD Helicopter... rotor lower hub assembly (lower hub) for a crack, and if you find a crack, before further...

  13. 77 FR 23388 - Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters

    Science.gov (United States)

    2012-04-19

    ... helicopters with certain main rotor blades installed to reduce the life limit of those blades. This AD is... main rotor blade and subsequent loss of control of the helicopter. DATES: This AD becomes effective May... blade failure and has reduced the life limit on all affected blades from 3,600 hours...

  14. Autonomic Nervous System Disorders

    Science.gov (United States)

    Your autonomic nervous system is the part of your nervous system that controls involuntary actions, such as the beating of your heart ... breathing and swallowing Erectile dysfunction in men Autonomic nervous system disorders can occur alone or as the result ...

  15. Autoimmune Autonomic Ganglionopathy

    Science.gov (United States)

    ... Accessed 9/2/2015. Autoimmune Autonomic Ganglionopathy Summary. Dysautonomia International . http://www.dysautonomiainternational.org/page.php?ID= ... page Basic Information In Depth Information Basic Information Dysautonomia International offers an information page on Autoimmune autonomic ...

  16. US Helicopter Expands Service to Newark Liberty International Airport

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ US Helicopter Corporation ("US Helicopter") (OTC Bulletin Board: USHP) and Continental Airlines (NYSE: CAL)announced a partnership to provide eight-minute shuttle service between Manhattan and Newark Liberty International Airport beginning Dec.18, 2006.

  17. 77 FR 39911 - The New York North Shore Helicopter Route

    Science.gov (United States)

    2012-07-06

    ... operations offshore. The FAA published the route on the Helicopter Route Chart for New York, effective May 8...'' (75 FR 29471). The FAA proposed requiring civil helicopters operating along Long Island, New York's... helicopter flights over communities along the north shore of Long Island by moving those flights offshore...

  18. 46 CFR 132.320 - Helicopter-landing decks.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Helicopter-landing decks. 132.320 Section 132.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS FIRE-PROTECTION EQUIPMENT Miscellaneous § 132.320 Helicopter-landing decks. Each vessel with a helicopter-landing deck...

  19. 78 FR 17593 - Airworthiness Directives; Bell Helicopter Textron, Inc.

    Science.gov (United States)

    2013-03-22

    ... lead to the loss of main rotor (M/R) blade pitch control and subsequent loss of helicopter control..., which could lead to the loss of M/R blade pitch control and subsequent loss of helicopter control... helicopters. This AD requires establishing a lower life limit on certain swashplate outer ring...

  20. Toward Visual Autonomous Ship Board Landing of a VTOL UAV

    OpenAIRE

    Sánchez López, José Luis; Saripalli, Srikanth; Campoy Cervera, Pascual; Pestana Puerta, Jesús; Fu, Changhong

    2013-01-01

    In this paper we tackle the problem of landing a helicopter autonomously on a ship deck, using as the main sensor, an on-board colour camera. To create a test-bed, we first adequately simulate the movement of a ship landing platform on the Sea, for different Sea States, for different ships, randomly and realistically enough. We use a commercial parallel robot to get this movement. Once we had this, we developed an accurate and robust computer vision system to measure the pose of the helipad w...

  1. Computer-vision-based autonomous control for quadrocopter

    OpenAIRE

    Lukežič, Alan

    2012-01-01

    The main goal of the thesis is presenting the implementation of the mobile platform Parrot AR.Drone for object tracking. Parrot is a quadrocopter – an aerial vehicle similar to a helicopter, but with four propellers. As there is a camera attached to it and there is the possibility of wireless connection via laptop, the system belongs to the computer vision and robotics field. We created a system which is capable of autonomous tracking a manually selected object. For tracking we used two exist...

  2. Evolution of civil aeromedical helicopter aviation.

    Science.gov (United States)

    Meier, D R; Samper, E R

    1989-07-01

    The rapid increase in the use of helicopters for hospital transport during the 1980s is the culmination of several hundred years of military medical innovation. Mass battefield casualties spurred both technologic and medical changes necessary for today's sophisticated helicopter systems in use worldwide, particularly in the United States. The Napoleonic Era and the American Civil War provided the framework for the evolution of today's state-of-the-art emergency medical techniques. The use of airplanes to evacuate the wounded eventually led to using helicopters for rescue missions in World War II. The combat experiences of the United States in Korea, the British in Malaya, and the French in Indochina proved that rotary-wing aircraft were invaluable in reducing battlefield death rates. Any skepticism about the efficacy of helicopter medical evacuation was erased during the Vietnam conflict. As an integral part of the modern battlefield, these specialized aircraft became a necessity. The observations and experience of American servicemen and medical personnel in Vietnam established the foundation for the acceptance of helicopter transport in modern hospital systems. PMID:2665130

  3. Helicopter stability during aggressive maneuvers

    Science.gov (United States)

    Mohan, Ranjith

    The dissertation investigates helicopter trim and stability during level bank-angle and diving bank-angle turns. The level turn is moderate in that sufficient power is available to maintain level maneuver, and the diving turn is severe where the power deficit is overcome by the kinetic energy of descent. The investigation basically represents design conditions where the peak loading goes well beyond the steady thrust limit and the rotor experiences appreciable stall. The major objectives are: (1) to assess the sensitivity of the trim and stability predictions to the approximations in modeling stall, (2) to correlate the trim predictions with the UH-60A flight test data, and (3) to demonstrate the feasibility of routinely using the exact fast-Floquet periodic eigenvector method for mode identification in the stability analysis. The UH-60A modeling and analysis are performed using the comprehensive code RCAS (Army's Rotorcraft Comprehensive Analysis System). The trim and damping predictions are based on quasisteady stall, ONERA-Edlin (Equations Differentielles Lineaires) and Leishman-Beddoes dynamic stall models. From the correlation with the test data, the strengths and weaknesses of the trim predictions are presented.

  4. A New Hybrid Control Architecture to Attenuate Large Horizontal Wind Disturbance for a Small-Scale Unmanned Helicopter

    Directory of Open Access Journals (Sweden)

    Xiaorui Zhu

    2012-07-01

    Full Text Available This paper presents a novel method to attenuate large horizontal wind disturbance for a small‐scale unmanned autonomous helicopter combining wind tunnel‐based experimental data and a backstepping algorithm. Large horizontal wind disturbance is harmful to autonomous helicopters, especially to small ones because of their low inertia and the high cross‐coupling effects among the multiple inputs. In order to achieve more accurate and faster attenuation of large wind disturbance, a new hybrid control architecture is proposed to take advantage of the direct force/moment compensation based on the wind tunnel experimental data. In this architecture, large horizontal wind disturbance is treated as an additional input to the control system instead of a small perturbation around the equilibrium state. A backstepping algorithm is then designed to guarantee the stable convergence of the helicopter to the desired position. The proposed technique is finally evaluated in simulation on the platform, HIROBO Eagle, compared with a traditional wind velocity compensation method.

  5. Simulation of Flow around Isolated Helicopter Fuselage

    Directory of Open Access Journals (Sweden)

    Garipov A.O.

    2013-04-01

    Full Text Available Low fuselage drag has always been a key target of helicopter manufacturers. Therefore, this paper focuses on CFD predictions of the drag of several components of a typical helicopter fuselage. In the first section of the paper, validation of the obtained CFD predictions is carried out using wind tunnel measurements. The measurements were carried out at the Kazan National Research Technical University n.a. A. Tupolev. The second section of the paper is devoted to the analysis of drag contributions of several components of the ANSAT helicopter prototype fuselage using the RANS approach. For this purpose, several configurations of fuselages are considered with different levels of complexity including exhausts and skids. Depending on the complexity of the considered configuration and CFD mesh both the multi-block structured HMB solver and the unstructured commercial tool Fluent are used. Finally, the effect of an actuator disk on the predicted drag is addressed.

  6. Autonomous Aerial Sensors for Wind Power Meteorology - A Pre-Project

    DEFF Research Database (Denmark)

    Giebel, Gregor; Schmidt Paulsen, Uwe; Bange, Jens;

    Autonomous Aerial Sensors, i.e. meteorological sensors mounted on Unmanned Aerial Systems UAS, can characterise the atmospheric flow in and around wind farms. We instrumented three planes, a helicopter and a lighter-than-air LTA system to fly one week together in a well-instrumented wind farm...... a wind farm in Lolland and on an atmospheric campaign in France. Planning of an offshore campaign using the developed techniques is underway....

  7. Depth Image Processing for Obstacle Avoidance of an Autonomous VTOL UAV

    OpenAIRE

    Andert, Franz; Strickert, Gordon; Thielecke, Frank

    2006-01-01

    We describe a new approach for stereo-based obstacle avoidance. This method analyzes the images of a stereo camera in realtime and searches for a safe target point that can be reached without collision. The obstacle avoidance system is used by our unmanned helicopter ARTIS (Autonomous Rotorcraft Testbed for Intelligent Systems) and its simulation environment. It is optimized for this UAV, but not limited to aircraft systems.

  8. Sources of helicopter rotor hub inplane shears

    Science.gov (United States)

    Kottapalli, Sesi

    1993-01-01

    Sources of helicopter rotor hub inplane shears are identified using simplified equations and the full aeroelastic analysis code, CAMRAD/JA (Johnson, 1988). Analytical results are obtained for an articulated rotor operating at moderate thrust and high airspeed. It is found that the blade chordwise inplane shear, which includes the aerodynamic component, the Coriolis contribution, and the inertial component, and the hub inplane shears are strongly dependent on the out-of-plane response. The sources of helicopter rotor hub inplane shears lie not only in the inplane response but depend on the flap and elastic flatwise responses/modes.

  9. Helicopter trajectory planning using optimal control theory

    Science.gov (United States)

    Menon, P. K. A.; Cheng, V. H. L.; Kim, E.

    1988-01-01

    A methodology for optimal trajectory planning, useful in the nap-of-the-earth guidance of helicopters, is presented. This approach uses an adjoint-control transformation along with a one-dimensional search scheme for generating the optimal trajectories. In addition to being useful for helicopter nap-of-the-earth guidance, the trajectory planning solution is of interest in several other contexts, such as robotic vehicle guidance and terrain-following guidance for cruise missiles and aircraft. A distinguishing feature of the present research is that the terrain constraint and the threat envelopes are incorporated in the equations of motion. Second-order necessary conditions are examined.

  10. Development of a Cost-efficient Autonomous MAV for an Unstructured Indoor Environment

    CERN Document Server

    Kernbach, Serge

    2011-01-01

    Performing rescuing and surveillance operations with autonomous ground and aerial vehicles become more and more apparent task. Involving unmanned robot systems allows making these operations more efficient, safe and reliable especially in hazardous areas. This work is devoted to the development of a cost-efficient micro aerial vehicle in a quadrocopter shape for developmental purposes within indoor scenarios. It has been constructed with off-the-shelf components available for mini helicopters. Additional sensors and electronics are incorporated into this aerial vehicle to stabilize its flight behavior and to provide a capability of an autonomous navigation in a partially unstructured indoor environment.

  11. Flight validated high-order models of UAV helicopter dynamics in hover and forward flight using analytical and parameter identification techniques

    Science.gov (United States)

    Bhandari, Subodh

    There has been a significant growth in the use of UAV helicopters for a multitude of military and civilian applications over the last few years. Due to these numerous applications, from crop dusting to remote sensing, UAV helicopters are now a major topic of interest within the aerospace community. The main research focus is on the development of automatic flight control systems (AFCS). The design of AFCS for these vehicles requires a mathematical model representing the dynamics of the vehicle. The mathematical model is developed either from first-principles, using the equations of motion of the vehicle, or from the flight data, using parameter identification techniques. The traditional six-degrees-of-freedom (6-DoF) dynamics model is not suitable for high-bandwidth control system design. Such models are valid only within the low- to mid-frequency range. The agility and high maneuverability of small-scale helicopters require a high-bandwidth control system for full authority autonomous performance. The design of a high-bandwidth control system in turn requires a high-fidelity simulation model that is able to capture the key dynamics of the helicopter. These dynamics include the rotor dynamics. This dissertation presents the development of a 14-degrees-of-freedom (14-DoF) state-space linear model for the KU Thunder Tiger Raptor 50 UAV helicopter from first-principles and from flight test data using a parameter identification technique for the hovering and forward flight conditions. The model includes rigid body, rotor regressive, rotor inflow, stabilizer bar, and rotor coning dynamics. The model is implemented within The MathWork's MATLAB/Simulink environment. The simulation results show that the high-order model is able to predict the helicopter's dynamics up to the frequency of 30 rad/sec. The main contributions of this dissertation are the development of a high-order simulation model for a small UAV helicopter from first-principles and the identification of a

  12. Laser Velocimeter For Use On Helicopter Rotor

    Science.gov (United States)

    Dunagan, Stephen E.

    1995-01-01

    Laser velocimeter developed to measure flow of air in vicinity of one of blades of helicopter rotor. Image-rotating optic transforms laser beams to rotating reference frame. Transformed beams stationary with respect to rotor blade; enabling continuous monitoring of velocity of flow at some point in reference frame attached to blade, provided that blade did not vibrate.

  13. 46 CFR 109.577 - Helicopter fueling.

    Science.gov (United States)

    2010-10-01

    ... subparts 98.30 and 98.33 of this chapter and the provisions of 49 CFR parts 171 through 179 that apply to... 46 Shipping 4 2010-10-01 2010-10-01 false Helicopter fueling. 109.577 Section 109.577 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS...

  14. Fuzzy logic mode switching in helicopters

    Science.gov (United States)

    Sherman, Porter D.; Warburton, Frank W.

    1993-01-01

    The application of fuzzy logic to a wide range of control problems has been gaining momentum internationally, fueled by a concentrated Japanese effort. Advanced Research & Development within the Engineering Department at Sikorsky Aircraft undertook a fuzzy logic research effort designed to evaluate how effective fuzzy logic control might be in relation to helicopter operations. The mode switching module in the advanced flight control portion of Sikorsky's motion based simulator was identified as a good candidate problem because it was simple to understand and contained imprecise (fuzzy) decision criteria. The purpose of the switching module is to aid a helicopter pilot in entering and leaving coordinated turns while in flight. The criteria that determine the transitions between modes are imprecise and depend on the varied ranges of three flight conditions (i.e., simulated parameters): Commanded Rate, Duration, and Roll Attitude. The parameters were given fuzzy ranges and used as input variables to a fuzzy rulebase containing the knowledge of mode switching. The fuzzy control program was integrated into a real time interactive helicopter simulation tool. Optimization of the heading hold and turn coordination was accomplished by interactive pilot simulation testing of the handling quality performance of the helicopter dynamic model. The fuzzy logic code satisfied all the requirements of this candidate control problem.

  15. Trigeminal autonomic cephalgias

    OpenAIRE

    Benoliel, Rafael

    2012-01-01

    1. Trigeminal autonomic cephalgias (TACs) are headaches/facial pains classified together based on:a suspected common pathophysiology involving the trigeminovascular system, the trigeminoparasympathetic reflex and centres controlling circadian rhythms;a similar clinical presentation of trigeminal pain, and autonomic activation.

  16. Testing for autonomic neuropathy

    DEFF Research Database (Denmark)

    Hilsted, J

    1984-01-01

    disease, and may be nonspecific. A number of recently developed quantifiable and reproducible autonomic nerve function tests are reviewed, with emphasis on the physiological basis of the tests and on practical applicability. Finally, diagnostic criteria, based on autonomic nerve function tests, are...

  17. Finite difference time domain grid generation from AMC helicopter models

    Science.gov (United States)

    Cravey, Robin L.

    1992-01-01

    A simple technique is presented which forms a cubic grid model of a helicopter from an Aircraft Modeling Code (AMC) input file. The AMC input file defines the helicopter fuselage as a series of polygonal cross sections. The cubic grid model is used as an input to a Finite Difference Time Domain (FDTD) code to obtain predictions of antenna performance on a generic helicopter model. The predictions compare reasonably well with measured data.

  18. Helicopter Emergency Medical Services: effects, costs and benefits

    OpenAIRE

    Ringburg, Akkie

    2009-01-01

    textabstractAdvanced prehospital medical care with air transport was introduced in the Netherlands in May 1995. The fi rst helicopter Mobile Medical Team, also called Helicopter Emergency Medical Service (HEMS) was a joint venture initiative of the VU Medical Center in Amsterdam and the Algemene Nederlandse WielrijdersBond (ANWB). The medical team consisted of a trauma surgeon or anaesthesiologist and a specialised trauma nurse, whereas, the ANWB Medical Air Assistance (MAA) helicopter compan...

  19. Helicopter mission optimization study. [portable computer technology for flight optimization

    Science.gov (United States)

    Olson, J. R.

    1978-01-01

    The feasibility of using low-cost, portable computer technology to help a helicopter pilot optimize flight parameters to minimize fuel consumption and takeoff and landing noise was demonstrated. Eight separate computer programs were developed for use in the helicopter cockpit using a hand-held computer. The programs provide the helicopter pilot with the ability to calculate power required, minimum fuel consumption for both range and endurance, maximum speed and a minimum noise profile for both takeoff and landing. Each program is defined by a maximum of two magnetic cards. The helicopter pilot is required to key in the proper input parameter such as gross weight, outside air temperature or pressure altitude.

  20. Autonomous linear lossless systems

    OpenAIRE

    Rao, Shodhan; Rapisarda, Paolo

    2008-01-01

    We define a lossless autonomous system as one having a quadratic differential form associated with it called an energy function, which is positive and which is conserved. We define an oscillatory system as one which has all its trajectories bounded on the entire time axis. In this paper, we show that an autonomous system is lossless if and only if it is oscillatory. Next we discuss a few properties of energy functions of autonomous lossless systems and a suitable way of splitting a given ener...

  1. Autonomous surveillance for biosecurity.

    Science.gov (United States)

    Jurdak, Raja; Elfes, Alberto; Kusy, Branislav; Tews, Ashley; Hu, Wen; Hernandez, Emili; Kottege, Navinda; Sikka, Pavan

    2015-04-01

    The global movement of people and goods has increased the risk of biosecurity threats and their potential to incur large economic, social, and environmental costs. Conventional manual biosecurity surveillance methods are limited by their scalability in space and time. This article focuses on autonomous surveillance systems, comprising sensor networks, robots, and intelligent algorithms, and their applicability to biosecurity threats. We discuss the spatial and temporal attributes of autonomous surveillance technologies and map them to three broad categories of biosecurity threat: (i) vector-borne diseases; (ii) plant pests; and (iii) aquatic pests. Our discussion reveals a broad range of opportunities to serve biosecurity needs through autonomous surveillance. PMID:25744760

  2. Noise reduction experience at Hughes Helicopter, Inc.

    Science.gov (United States)

    Janakiram, D. S.

    1982-01-01

    Noise reduction is mostly limited to light helicopters whose noise signature is dominated by their tail rotors. It is primarily hardware oriented. Well known noise reduction techniques such as reduction of rotor speeds with an accompanying increase in solidity to maintain performance, engine noise reduction with the use of exhaust mufflers, and acoustic blanketing of transmission and engine compartment are used. The concept of blade phasing as a means of reducing tail rotor noise is also used. Engine noise (exhaust noise), power train noise and airframe noise becomes important at low rotor tip speeds and means must be found to reduce these noise sources if further noise reductions are desired. The use of a special test rig aids in isolating the various noise sources and arriving at the penalties (performance or payload) involved in quieting them. Significant noise reduction are achieved for the light helicopter with minimum performance or weight penalties because of the dominance of a single noise source (the tail rotor).

  3. Vehicle for civil helicopter ride quality research

    Science.gov (United States)

    Snyder, W. J.; Schlegel, R. G.

    1975-01-01

    A research aircraft for investigating the factors involved in civil helicopter operations was developed for NASA Langley Research Center. The aircraft is a reconfigured 17000 kg (36000 lb) military transport helicopter. The basic aircraft was reconfigured with advanced acoustic treatment, air-conditioning, and a 16-seat airline cabin. During the spring of 1975, the aircraft was flight tested to measure interior environment characteristics - noise and vibration - and was flown on 60 subjective flight missions with over 600 different subjects. Data flights established noise levels somewhat higher than expected, with a pure tone at 1400 Hz and vertical vibration levels between 0.07g and 0.17g. The noise and vibration levels were documented during subjective flight evaluations as being the primary source of discomfort. The aircraft will be utilized to document in detail the impact of various noise and vibration levels on passenger comfort during typical short-haul missions.

  4. Optimal short range trajectories for helicopters

    Science.gov (United States)

    Slater, G. L.; Erzberger, H.

    1983-01-01

    An optimal flight path algorithm using a simplified altitude state model and an apriori climb-cruise-descent flight profile has been developed and applied to determine minimum fuel and minimum cost trajectories for a helicopter flying a fixed range trajectory. The performance model is based on standard flight manual data and is such that on-line trajectory optimization is feasible with a relatively small computer. The results show that the optimal flight path and optimal cruise altitude can represent a 10 percent fuel saving on a minimum fuel trajectory. The optimal trajectories show considerable variability due to helicopter weight, ambient winds and the relative cost trade-off between time and fuel. In general, 'reasonable' variations from the optimal velocities and cruise altitudes do not significantly degrade the optimal cost.

  5. Model helicopter rotor low frequency broadband noise

    Science.gov (United States)

    Humbad, N. G.; Harris, W. L.

    1982-01-01

    The results of an experimental investigation of low frequency broadband noise (LFBN) radiated from model helicopter rotors are presented. The results up to tip Mach number of 0.50 suggest that the peak sound pressure level (SPL) of LFBN appears to follow tip Mach number to a fourth power law and rms velocity of turbulence to a second power law. The experimental results on the effect of tip speed and advance ratio on the peak SPL of LFBN can be explained on the basis of a simple scaling law. However, the experimental results on the effect of blade loading on the peak SPL of LFBN is still not clearly understood. A simple peak SPL scaling law for noise from a helicopter in forward flight encountering a sinusoidal gust is also developed. The trends predicted by the scaling law with the experimental results are found satisfactory for the cases of variation of the peak SPL of LFBN with tip speed and advance ratio.

  6. Learning Basic Mechatronics through Helicopter Workshop

    OpenAIRE

    Adzly Anuar; Maryam Huda Ahmad Phesal; Azrul Abidin Zakaria; Goh Chin Hock; Sivadass Thiruchelvam; Dickson Neoh Tze How; Muhammad Fahmi Abdul Ghani; Khairul Salleh Mohamed Sahari

    2014-01-01

    In recent years, technologies related to mechatronics and robotics is available even to elementary level students. It is now common to see schools in Malaysia using Lego Mindstorm as a tool for active learning on mechatronics and robotics. A new yet interesting way of learning mechatronics and robotics is introduced by Dr. Dan Barry, a former astronaut and his son Andrew Barry during their visit to Malaysia. The kits used are based on a 4-channel RC helicopter, Arduino Uno microcontroller, IR...

  7. Helicopter Airborne Laser Positioning System (HALPS)

    Science.gov (United States)

    Eppel, Joseph C.; Christiansen, Howard; Cross, Jeffrey; Totah, Joseph

    1990-01-01

    The theory of operation, configuration, laboratory, and ground test results obtained with a helicopter airborne laser positioning system developed by Princeton University is presented. Unfortunately, due to time constraints, flight data could not be completed for presentation at this time. The system measures the relative position between two aircraft in three dimensions using two orthogonal fan-shaped laser beams sweeping across an array of four detectors. Specifically, the system calculates the relative range, elevation, and azimuth between an observation aircraft and a test helicopter with a high degree of accuracy. The detector array provides a wide field of view in the presence of solar interference due to compound parabolic concentrators and spectral filtering of the detector pulses. The detected pulses and their associated time delays are processed by the electronics and are sent as position errors to the helicopter pilot who repositions the aircraft as part of the closed loop system. Accuracies obtained in the laboratory at a range of 80 ft in the absence of sunlight were + or - 1 deg in elevation; +0.5 to -1.5 deg in azimuth; +0.5 to -1.0 ft in range; while elevation varied from 0 to +28 deg and the azimuth varied from 0 to + or - 45 deg. Accuracies in sunlight were approximately 40 deg (+ or - 20 deg) in direct sunlight.

  8. AUTONOMOUS DRIVEN CAR

    OpenAIRE

    Meeshika Arora

    2013-01-01

    In order to achieve autonomous operation of a vehiclein urban situations with unpredictable traffic, several real timesystems must interoperate, including environment perceptionplanning and control. In addition a robust vehicle platform withappropriate sensors, computational hardware, networking andsoftware infrastructure is essential.

  9. Highly Autonomous Systems Workshop

    Science.gov (United States)

    Doyle, R.; Rasmussen, R.; Man, G.; Patel, K.

    1998-01-01

    It is our aim by launching a series of workshops on the topic of highly autonomous systems to reach out to the larger community interested in technology development for remotely deployed systems, particularly those for exploration.

  10. Engineering Autonomous Driving Software

    OpenAIRE

    Berger, Christian; Rumpe, Bernhard

    2014-01-01

    A larger number of people with heterogeneous knowledge and skills running a project together needs an adaptable, target, and skill-specific engineering process. This especially holds for a project to develop a highly innovative, autonomously driving vehicle to participate in the 2007 DARPA Urban Challenge. In this contribution, we present essential elements of a software and systems engineering process to develop a so-called artificial intelligence capable of driving autonomously in complex u...

  11. Autonomous Star Tracker Algorithms

    DEFF Research Database (Denmark)

    Betto, Maurizio; Jørgensen, John Leif; Kilsgaard, Søren;

    1998-01-01

    Proposal, in response to an ESA R.f.P., to design algorithms for autonomous star tracker operations.The proposal also included the development of a star tracker breadboard to test the algorithms performances.......Proposal, in response to an ESA R.f.P., to design algorithms for autonomous star tracker operations.The proposal also included the development of a star tracker breadboard to test the algorithms performances....

  12. Radiation Monitoring using an Unmanned Helicopter in the Evacuation Zone Set up by the Fukushima Daiichi NPP Accident.

    Science.gov (United States)

    Torii, Tatsuo; Sanada, Yukihisa; Nishizawa, Yukiyasu; Kondo, Atsuya; Shoji, Yasunori; ikeda, Kazutaka

    2013-04-01

    By the nuclear accident of the Fukushima Daiichi Nuclear Power Plant (NPP) caused by the East Japan earthquake and the following tsunami occurred on March 11, 2011, a large amount of radioactive materials was released from the NPP. In recent years, technologies for an unmanned helicopter have been developed and applied to natural disasters. In expectation of the application of the unmanned helicopter to airborne radiation monitoring, we had developed a radiation monitoring system using an autonomous unmanned helicopter (AUH). Then, we measured the ambient dose-rate at the height of 1-m above the ground and the soil deposition of radioactive cesium (Cs-134, Cs-137) by using the AUH system in the evacuation zone of residents around the NPP. Here, we report on the measurement technique and the result. As a result measured around a river at 10-km away from the NPP, high contaminated areas compared with the circumstance are detected along the dry riverbed. It was seemed that it had flowed along the river from highly contaminated areas in the upper stream.

  13. On the capability of helicopter gravimetry.

    Science.gov (United States)

    Bielenberg, Olaf; Meyer, Uwe; Götze, Hans-Jürgen; Choi, Sungchan

    2010-05-01

    Affordable, high performance inertial navigation systems, their integration with GPS, and modern high performance airborne vertical sensors make helicopter gravimetry an attractive alternative to other methods for obtaining gravity data. As part of the Dead Sea Integrated Research Project (DESIRE) in late spring 2007 a helicopter borne gravimetry survey was conducted over the Dead Sea Basin along and across the rift between Aquaba and the Dead Sea. A German Sikorsky S-76B helicopter system was used to carry a GT-1A gravity meter system supplied by Canadian Micro Gravity. The GT-1A is an airborne, single vertical sensor, GPS-INS scalar gravity meter with a Schuler-tuned three-axis gyro-stabilized inertial platform, that uses intelligent platform control to maintain platform verticality during turbulent motion. Low speed and terrain following helicopter gravity flights were performed to acquire the best possible data quality and high resolution, considering extreme elevation differences associated with the Dead Sea Basin. The Dead Sea Valley lies more than 400 m below sea level, while the shoulders are more than 1500 m high. The resulting initial airborne gravity data were merged with existent ground based data for enhanced mapping and modelling providing a seamless gravity map of the area. During terrain following flights the vertical accelerations effecting the helicopter and also the vertical sensor of the gravity meter are logically much higher compared to straight level flights. To investigate the effects of this two different flight performances on the gravity measurements, a test flight over flat terrain at a constant altitude with very small vertical accelerations was performed. The acceleration data occurred during this simulated airborne survey flight were recorded using an inertial measurement unit iVRU-FC constructed by iMAR-Navigation, which was also part of the equipment used during the gravimetry survey flights of DESIRE. This means that the

  14. 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.

  15. Detection of Sensor Faults in Small Helicopter UAVs Using Observer/Kalman Filter Identification

    Directory of Open Access Journals (Sweden)

    Guillermo Heredia

    2011-01-01

    Full Text Available Reliability is a critical issue in navigation of unmanned aerial vehicles (UAVs since there is no human pilot that can react to any abnormal situation. Due to size and cost limitations, redundant sensor schemes and aeronautical-grade navigation sensors used in large aircrafts cannot be installed in small UAVs. Therefore, other approaches like analytical redundancy should be used to detect faults in navigation sensors and increase reliability. This paper presents a sensor fault detection and diagnosis system for small autonomous helicopters based on analytical redundancy. Fault detection is accomplished by evaluating any significant change in the behaviour of the vehicle with respect to the fault-free behaviour, which is estimated by using an observer. The observer is obtained from input-output experimental data with the Observer/Kalman Filter Identification (OKID method. The OKID method is able to identify the system and an observer with properties similar to a Kalman filter, directly from input-output experimental data. Results are similar to the Kalman filter, but, with the proposed method, there is no need to estimate neither system matrices nor sensor and process noise covariance matrices. The system has been tested with real helicopter flight data, and the results compared with other methods.

  16. Optical Detection Of Ice On A Helicopter Rotor

    Science.gov (United States)

    Cornwell, Donald M., Jr.; Spadin, Paul L.

    1992-01-01

    Ice forming on helicopter rotor blades under adverse weather conditions detected via effect on polarization of reflected light, according to proposal. Ice-detection system based on this principal alerts helicopter pilot to need for corrective action, and/or turns on deicing equipment automatically.

  17. 77 FR 42971 - Airworthiness Directives; Various Restricted Category Helicopters

    Science.gov (United States)

    2012-07-23

    ... helicopters to require inspecting the main rotor mast (mast) for a crack. This AD is prompted by two reported... condition described previously is likely to exist or develop in other helicopters of the same type design... because they have the same mast design and are operated similarly to the AFE fleet. This AD does...

  18. 77 FR 64706 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-10-23

    ... result in failure of the main rotor transmission and subsequent loss of control of the helicopter. To... exists and is likely to exist or develop on other helicopters of the same type design. Related Service... result in the chip-detector system failing to detect deterioration of the main rotor mast lift...

  19. The Helicopter Parent (Part 2): International Arrivals and Departures

    Science.gov (United States)

    Somers, Patricia; Settle, Jim

    2010-01-01

    The phenomenon of helicopter parenting has been widely reported, yet the research literature is anemic on the topic. Based on interviews and focus groups involving 190 academic and student services professionals, this article continues by discussing the social, psychological, economic, and cultural factors that influence helicoptering; exploring…

  20. 78 FR 58256 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-09-23

    ... (78 FR 24041) for Eurocopter Model AS350B3 helicopters with MOD 07 5601 installed. AD 2012-25-04... requirements of AD 2012-25-04, Amendment 39-17285 (78 FR 24041, April 24, 2013). Additionally, this proposed AD... FR 24041, April 24, 2013). Modifying the helicopter would be terminating action for the...

  1. 78 FR 24041 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-04-24

    ... Procedures (44 FR 11034, February 26, 1979); 3. Will not affect intrastate aviation in Alaska to the extent... France Helicopters AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT... directive (EAD) for Eurocopter France (Eurocopter) Model AS350B3 helicopters with certain...

  2. 46 CFR 108.489 - Helicopter fueling facilities.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Helicopter fueling facilities. 108.489 Section 108.489 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems Fire Protection for Helicopter Facilities §...

  3. 46 CFR 108.487 - Helicopter deck fueling operations.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Helicopter deck fueling operations. 108.487 Section 108.487 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems Fire Protection for Helicopter Facilities §...

  4. 29 CFR 1926.958 - External load helicopters.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false External load helicopters. 1926.958 Section 1926.958 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... External load helicopters. In all operations performed using a rotorcraft for moving or placing...

  5. 77 FR 57524 - Stage 3 Helicopter Noise Certification Standards

    Science.gov (United States)

    2012-09-18

    ... * * * (a) Limits. For compliance with this appendix, the applicant must show by flight test that the... Privacy Act Statement can be found in the Federal Register published on April 11, 2000 (65 FR 19477-19478... lowering of noise limits for new helicopter types while using the same helicopter noise certification...

  6. Model Tests on the Economy and Effectiveness of Helicopter Propellers

    Science.gov (United States)

    Munk, Max M

    1925-01-01

    The average velocity of helicopter blades relative to the air is greater than that of airplane wings. The helicopter may turn out to be more economical than the airplane wing for extreme velocities of horizontal flight, the airplane then requiring a very great speed range.

  7. Helicopter Emergency Medical Services: effects, costs and benefits

    NARCIS (Netherlands)

    A.N. Ringburg (Akkie)

    2009-01-01

    textabstractAdvanced prehospital medical care with air transport was introduced in the Netherlands in May 1995. The fi rst helicopter Mobile Medical Team, also called Helicopter Emergency Medical Service (HEMS) was a joint venture initiative of the VU Medical Center in Amsterdam and the Algemene Ned

  8. 78 FR 37152 - Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

    Science.gov (United States)

    2013-06-20

    ... reducing the life limit of the blade if the spar spacer is oversized. This proposed AD is prompted by the... life limits of those main rotor blades. The proposed actions are intended to prevent failure of a M/R blade and subsequent loss of control of the helicopter. DATES: We must receive comments on this...

  9. 75 FR 52912 - Airworthiness Directives; Bell Helicopter Textron Canada Limited Model 427 Helicopters

    Science.gov (United States)

    2010-08-30

    ... 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034... 427 helicopters, all serial numbers (SNs), certificated in any category. Subject (d) Air Transport... already done, do the following actions: (1) Applicable to SNs 56001 through 56073, and 56077: Within...

  10. 76 FR 2607 - Airworthiness Directives; MD Helicopters, Inc. (MDHI) Model MD900 Helicopters

    Science.gov (United States)

    2011-01-14

    ... position. (ii) Pull the following AP circuit breakers located on the A601 Essential Bus Circuit Breaker... YSAS switches instead of pulling the circuit breakers and installing placards that limit airspeed to... the helicopter to its normal configuration by returning the switches and circuit breakers to...

  11. 75 FR 62639 - Air Ambulance and Commercial Helicopter Operations, Part 91 Helicopter Operations, and Part 135...

    Science.gov (United States)

    2010-10-12

    ... in the Federal Register published on April 11, 2000 (65 FR 19477-78) or you may visit http://Dockets.... Helicopter air medical transportation was first used prominently during the Korean War to move injured... safety culture, and aeronautical decisionmaking skills. The following provides a summary of many of...

  12. 77 FR 64439 - Airworthiness Directives; Bell Helicopter Textron Canada (Bell) Model Helicopters

    Science.gov (United States)

    2012-10-22

    ... and copilot airspeed indicators; (ii) Leak test the pilot pitot static system; and (iii) Operationally test the overspeed warning system. (2) For helicopters with a Single or Dual Automatic Flight Control... Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not affect intrastate aviation in...

  13. Neck and shoulder muscle activity and posture among helicopter pilots and crew-members during military helicopter flight

    DEFF Research Database (Denmark)

    Murray, Mike; Lange, Britt; Chreiteh, Shadi Samir;

    2016-01-01

    Neck pain among helicopter pilots and crew-members is common. This study quantified the physical workload on neck and shoulder muscles using electromyography (EMG) measures during helicopter flight. Nine standardized sorties were performed, encompassing: cruising from location A to location B (AB...

  14. Effects of exhaust temperature on helicopter infrared signature

    International Nuclear Information System (INIS)

    The effects of exhaust temperature on infrared signature (in 3–5 μm band) for a helicopter equipped with integrative infrared suppressor were numerically investigated. The internal flow of exhaust gas and the external downwash flow, as well as the mixing between exhaust gas and downwash were simulated by CFD software to determine the temperature distributions on the helicopter skin and in the exhaust plume. Based on the skin and plume temperature distributions, a forward–backward ray-tracing method was used to calculate the infrared radiation intensity from the helicopter with a narrow-band model. The results show that for a helicopter with its integrative infrared suppressor embedded inside its rear airframe, the exhaust temperature has significant influence on the plume radiation characteristics, while the helicopter skin radiation intensity has little impact. When the exhaust temperature is raised from 900 K to 1200 K, the plume radiation intensity in 3–5 μm band is increased by about 100%, while the skin radiation intensity is increased by only about 5%. In general, the effects of exhaust temperature on helicopter infrared radiation intensity are mainly concentrated on plume, especially obvious for a lower skin emissivity case. -- Highlights: ► The effect of exhaust temperature on infrared signature for a helicopter is numerically investigated. ► The impact of exhaust temperature on helicopter skin temperature is revealed. ► The impact of exhaust temperature on plume radiation characteristics is revealed. ► The impact of exhaust temperature on helicopter skin radiation is revealed. ► The impact of exhaust temperature on helicopter's total infrared radiation intensity is revealed

  15. Novel approaches to helicopter obstacle warning

    Science.gov (United States)

    Seidel, Christian; Samuelis, Christian; Wegner, Matthias; Münsterer, Thomas; Rumpf, Thomas; Schwartz, Ingo

    2006-05-01

    EADS Germany is the world market leader in commercial Helicopter Laser Radar (HELLAS) Obstacle Warning Systems. The HELLAS-Warning System has been introduced into the market in 2000, is in service at German Border Control (Bundespolizei) and Royal Thai Airforce and is successfully evaluated by the Foreign Comparative Test Program (FCT) of the USSOCOM. Currently the successor system HELLAS-Awareness is in development. It will have extended sensor performance, enhanced realtime data processing capabilities and advanced HMI features. We will give an outline of the new sensor unit concerning detection technology and helicopter integration aspects. The system provides a widespread field of view with additional dynamic line of sight steering and a large detection range in combination with a high frame rate of 3Hz. The workflow of the data processing will be presented with focus on novel filter techniques and obstacle classification methods. As commonly known the former are indispensable due to unavoidable statistical measuring errors and solarisation. The amount of information in the filtered raw data is further reduced by ground segmentation. The remaining raised objects are extracted and classified in several stages into different obstacle classes. We will show the prioritization function which orders the obstacles concerning to their threat potential to the helicopter taking into account the actual flight dynamics. The priority of an object determines the display and provision of warnings to the pilot. Possible HMI representation includes video or FLIR overlay on multifunction displays, audio warnings and visualization of information on helmet mounted displays and digital maps. Different concepts will be presented.

  16. Composite curved frames for helicopter fuselage structure

    Science.gov (United States)

    Rich, M. J.; Lowry, D. W.

    1984-01-01

    This paper presents the results of analysis and testing of composite curved frames. A major frame was selected from the UH-60 Black Hawk helicopter and designed as a composite structure. The curved beam effects were expected to increase flange axial stresses and induce transverse bending. A NASTRAN finite element analysis was conducted and the results were used in the design of composite curved frame specimens. Three specimens were fabricated and five static tests were conducted. The NASTRAN analysis and test results are compared for axial, transverse, and Web strains. Results show the curved beam effects are closely predicted by a NASTRAN analysis and the effects increase with loading on the composite frames.

  17. Architecture of autonomous systems

    Science.gov (United States)

    Dikshit, Piyush; Guimaraes, Katia; Ramamurthy, Maya; Agrawala, Ashok; Larsen, Ronald L.

    1989-01-01

    Automation of Space Station functions and activities, particularly those involving robotic capabilities with interactive or supervisory human control, is a complex, multi-disciplinary systems design problem. A wide variety of applications using autonomous control can be found in the literature, but none of them seem to address the problem in general. All of them are designed with a specific application in mind. In this report, an abstract model is described which unifies the key concepts underlying the design of automated systems such as those studied by the aerospace contractors. The model has been kept as general as possible. The attempt is to capture all the key components of autonomous systems. With a little effort, it should be possible to map the functions of any specific autonomous system application to the model presented here.

  18. Exercise and autonomic function.

    Science.gov (United States)

    Goldsmith, R L; Bloomfield, D M; Rosenwinkel, E T

    2000-03-01

    The complex interplay between the dichotomous subdivisions of the autonomic nervous system establishes and maintains a delicately tuned homeostasis in spite of an ever-changing environment. Aerobic exercise training can increase activity of the parasympathetic nervous system and decrease sympathetic activity. Conversely, it is well-documented that cardiac disease is often characterized by attenuated parasympathetic activity and heightened sympathetic tone. A correlation between autonomic disequilibrium and disease has led to the hypothesis that exercise training, as a therapy that restores the autonomic nervous system towards normal function, may be associated with, and possibly responsible for, outcome improvements in various populations. This is merely one of the many benefits that is conferred by chronic exercise training and reviewed in this issue. PMID:10758814

  19. Overview of the Autonomic Nervous System

    Science.gov (United States)

    ... reversible or progressive. Anatomy of the autonomic nervous system The autonomic nervous system is the part of ... they connect with. Function of the autonomic nervous system The autonomic nervous system controls internal body processes ...

  20. Image based augmentation of an autonomous VTOL-MAV

    Science.gov (United States)

    Frietsch, N.; Maier, A.; Kessler, C.; Meister, O.; Seibold, J.; Trommer, G. F.

    2009-09-01

    In this paper, the development of a vision based system for a small-scale VTOL-MAV is presented. The on-board GPS/INS navigation system is augmented by further sensors in order to allow for an autonomous waypoint mode. Especially in urban environments the GPSsignal quality is disturbed by shading and multipath propagation. The investigated vision system based on algorithms analyzing the optical flow is essential to enable the helicopter to reliably hover even in these scenarios. Due to the integration of the vision based navigation information into the navigation filter, GPSsignal outages can be bridged. The necessary height above ground information is estimated from the relative altitude change given by the barometric altimeter and the optical flow.

  1. Experimental Autonomous Vehicle Systems

    DEFF Research Database (Denmark)

    Ravn, Ole; Andersen, Nils Axel

    1998-01-01

    The paper describes the requirements for and a prototype configuration of a software architecture for control of an experimental autonomous vehicle. The test bed nature of the system is emphasised in the choice of architecture making re-configurability, data logging and extendability simple. The...

  2. ADAM: ADaptive Autonomous Machine

    NARCIS (Netherlands)

    Oosten, van Daan C.; Nijenhuis, Lucas F.J.; Bakkers, André W.P.; Vervoort, Wiek A.

    1996-01-01

    This paper describes a part of the development of an adaptive autonomous machine that is able to move in an unknown world extract knowledge out of the perceived data, has the possibility to reason, and finally has the capability to exchange experiences and knowledge with other agents. The agent is n

  3. Autonomous Security Patrol System

    OpenAIRE

    Erramouspe, Jake

    2010-01-01

    This project provides an efficient and cost-effective solution to building security and active monitoring. The security is monitored and controlled by autonomous patrol robots. Any indication of a security breach will result in an immediate alarm and activation of the robot group to subdue and tranquilize the intruder.

  4. Software Architecture for Autonomous Spacecraft

    Science.gov (United States)

    Shih, Jimmy S.

    1997-01-01

    The thesis objective is to design an autonomous spacecraft architecture to perform both deliberative and reactive behaviors. The Autonomous Small Planet In-Situ Reaction to Events (ASPIRE) project uses the architecture to integrate several autonomous technologies for a comet orbiter mission.

  5. Importance of engine as a source of helicopter external noise

    Science.gov (United States)

    Janakiram, R. D.; Smith, M. J.; Tadghighi, H.

    1989-01-01

    A turboshaft engine's importance as a source of helicopter external noise is presently evaluated experimentally and analytically on the basis of test data from an MD500E helicopter, with and without engine muffler, during level flyovers and climbing flight. A strong engine noise component is noted for helicopter positions nearly overhead and beyond observed position, especially in the 200-1000 Hz range; its strong rearward directivity suggests the noise source to be the broadband exhaust or combustion noise radiated from the exhaust duct. The engine muffler furnished estimated perceived noise level reductions of 2-3 dB for the centerline.

  6. Optical Shaft-Angle Encoder For Helicopter Rotor

    Science.gov (United States)

    Golub, Robert A.; Fitzpatrick, Fred; Dennis, Dale V.; Taylor, Bryant D.

    1993-01-01

    Angular position of helicopter rotor blade determined precisely. Accomplished by use of optical shaft-angle encoder called "256 Ring" on rotor swashplate. Each 360 degree rotation of helicopter main rotor broken down into 256 reflective segments. As rotor rotates, beam of light reflected in turn from each segment into optoelectronic system. One of 256 segments reflects larger pulse than others do. Position of rotor determined by counting number of pulses after this reference pulse. While swashplate mounting requirements unique to each type of helicopter, concept applicable to all types of rotorcraft.

  7. Study of the helicopter blade running elevation measurement system

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Helicopter blade running elevation measurement is an important measure target in helicopter blade dynamic balance experimentation. The elevation influences the helicopter's security and other performance capabilities. In testing, however, it has been difficult to measure the elevation when the rotor reaches high speeds. To get a simple, fast and highly accurate measurement system, photo electricity technology was applied to measuring the blade running elevation. Discussed is the measurement principle of blade running elevation, the design of the measurement system and analysis of the measurement precision.

  8. Simulating effectiveness of helicopter evasive manoeuvres to RPG attack

    Science.gov (United States)

    Anderson, D.; Thomson, D. G.

    2010-04-01

    The survivability of helicopters under attack by ground troops using rocket propelled grenades has been amply illustrated over the past decade. Given that an RPG is unguided and it is infeasible to cover helicopters in thick armour, existing optical countermeasures are ineffective - the solution is to compute an evasive manoeuvre. In this paper, an RPG/helicopter engagement model is presented. Manoeuvre profiles are defined in the missile approach warning sensor camera image plane using a local maximum acceleration vector. Required control inputs are then computed using inverse simulation techniques. Assessments of platform survivability to several engagement scenarios are presented.

  9. Operators end helicopter flights ferrying crews over rough seas

    Energy Technology Data Exchange (ETDEWEB)

    Roche, Pat

    2011-04-15

    New criteria for offshore helicopter flight safety have been established by oil and gas operators in Newfoundland and Labrador following a 2009 crash investigation. Choppers will no longer fly personnel over rough seas when they exceed the capability of the flotation equipment. Seventeen people died when a Sikorsky S-92A helicopter crashed into the sea. Offshore oil and gas operators in Newfoundland presently contract five large helicopters; the three that are used regularly for passengers are enhanced with flotation equipment that can stand six metre waves and the other two have the standard manufacturer's equipment to survive four metre waves.

  10. Task and Motion Planning for Selective Weed Conrol using a Team of Autonomous Vehicles

    DEFF Research Database (Denmark)

    Hameed, Ibrahim; la Cour-Harbo, Anders; Hansen, Karl Damkjær

    2014-01-01

    with the right amount. In this article, a task and motion planning for a team of autonomous vehicles to reduce chemicals in farming is presented. Field data are collected by small unmanned helicopters equipped with a range of sensors, including multispectral and thermal cameras. Data collected are transmitted...... to a ground station to be analyzed and triggers aerial and ground-based vehicles to start close inspection and/or plant/weed treatment in specified areas. A complete trajectory is generated to enable ground-based vehicle to visit infested areas and start chemical/mechanical weed treatment....

  11. A Computational Tool for Helicopter Rotor Noise Prediction Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project proposes to develop a computational tool for helicopter rotor noise prediction based on hybrid Cartesian grid/gridless approach. The uniqueness of...

  12. Flight tests of IFR landing approach systems for helicopters

    Science.gov (United States)

    Bull, J. S.; Hegarty, D. M.; Peach, L. L.; Phillips, J. D.; Anderson, D. J.; Dugan, D. C.; Ross, V. L.

    1981-01-01

    Joint NASA/FAA helicopter flight tests were conducted to investigate airborne radar approaches (ARA) and microwave landing system (MLS) approaches. Flight-test results were utilized to prove NASA with a data base to be used as a performance measure for advanced guidance and navigation concepts, and to provide FAA with data for establishment of TERPS criteria. The first flight-test investigation consisted of helicopter IFR approaches to offshore oil rigs in the Gulf of Mexico, using weather/mapping radar, operational pilots, and a Bell 212 helicopter. The second flight-test investigation consisted of IFR MLS approaches at Crows Landing (near Ames Research Center), with a Bell UH-1H helicopter, using NASA, FAA, and operational industry pilots. Tests are described and results discussed.

  13. AN EXPERIMENTAL EVALUATION OF 3D TERRAIN MAPPING WITH AN AUTONOMOUS HELICOPTER

    Directory of Open Access Journals (Sweden)

    B. P. Hudzietz

    2012-09-01

    Full Text Available We demonstrate a method for unmanned aerial vehicle based structure from motion mapping and show it to be a viable option for large scale, high resolution terrain modeling. Current methods of large scale terrain modeling can be cost and time prohibitive. We present a method for integrating low cost cameras and unmanned aerial vehicles for the purpose of 3D terrain mapping. Using structure from motion, aerial images taken of the landscape can be reconstructed into 3D models of the terrain. This process is well suited for use on unmanned aerial vehicles due to the light weight and low cost of equipment. We discuss issues of flight path planning and propose an algorithm to assist in the generation of these paths. The structure from motion mapping process is experimentally evaluated in three distinct environments: ground based testing on man-made environments, ground based testing on natural environments, and airborne testing on natural environments. Ground based testing on natural environments was shown to be extremely useful for camera calibration, and the resulting models were found to have a maximum error of 4.26 cm and standard deviation of 1.50 cm. During airborne testing, several areas of approximately 30,000 m2 were mapped. These areas were mapped with acceptable accuracy and a resolution of 1.24 cm.

  14. 78 FR 23692 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-04-22

    ... AS350B, BA, B1, B2, B3, and D, and Model AS355E, F, F1, F2, and N helicopters with certain tail rotor (T..., F1, F2, and N helicopters with a tail rotor (T/R) blade, part number (P/N) 355A12-0040-00, 355A-12... ] exist or develop on other products of the same type design. Related Service Information We...

  15. Vertical-plane pendulum absorbers for minimizing helicopter vibratory loads

    Science.gov (United States)

    Amer, K. B.; Neff, J. R.

    1974-01-01

    The use of pendulum dynamic absorbers mounted on the blade root and operating in the vertical plane to minimize helicopter vibratory loads was discussed. A qualitative description was given of the concept of the dynamic absorbers and some results of analytical studies showing the degree of reduction in vibratory loads attainable are presented. Operational experience of vertical plane dynamic absorbers on the OH-6A helicopter is also discussed.

  16. Advanced Modelling of Helicopter Nonlinear Dynamics and Aerodynamics

    OpenAIRE

    Castillo-Rivera, Salvador

    2014-01-01

    The work presented here provides a comprehensive dynamic and aerodynamic helicopter model. The possible applications of this work are wide including, control systems applications, reference and trajectory tracking methods implementation amongst others. The model configuration corresponds to a Sikorsky helicopter; a main rotor in perpendicular combination with a tail rotor. Also, a particular model of unmanned aerial vehicle has been modelled as part of collaboration with the La Laguna Univers...

  17. A Simplified Mobile Ad Hoc Network Structure for Helicopter Communication

    OpenAIRE

    Abdelgader, Abdeldime Mohamed Salih; Wu, Lenan; Nasr, Mohammed Mohsen Mohammed

    2016-01-01

    There are a number of volunteer and statutory organizations who are capable of conducting an emergency response using helicopters. Rescue operations require a rapidly deployable high bandwidth network to coordinate necessary relief efforts between rescue teams on the ground and helicopters. Due to massive destruction and loss of services, ordinary communication infrastructures may collapse in these situations. Consequently, information exchange becomes one of the major challenges in these cir...

  18. Helicopter Rotor Blade With Free Tip

    Science.gov (United States)

    Stroub, Robert H.; Young, Larry; Cawthorne, Matthew; Keys, Charles

    1992-01-01

    Free-tip rotor blades improve fuel efficiency and performance characteristics of helicopters. Outermost portion of blade pivots independently with respect to inboard portion about pitch axis parallel to blade axis, located forward of aerodynamic center. Centrifugal force acts on tension/torsion strap and biases tip nose-up. Airstream turns tip nose-down, other torques cause tip to "weathervane" to intermediate angular position resulting in net lift. Reduces fluctuations in lift, with two effects: flapwise vibratory loads on blade and vibratory loads on pitch-control mechanism reduced; negative lift produced by advancing fixed tip eliminated, reducing power required to achieve same overall lift. Applies to tilt rotors and tail rotors as well.

  19. On helicopter rotor low frequency broadband noise

    Science.gov (United States)

    Williams, Morgan; Harris, Wesley L.

    1985-01-01

    The effect of shear-layer-type inflow turbulence on the low-frequency broadband noise of a model helicopter rotor is experimentally studied. The measurements and the one-dimensional energy spectral density indicate that the upstream airfoil wake turbulence is nonisotropic, but approaches isotropy at high wavenumbers. Turbulence measurements also indicate that the wake turbulence is weak. The effect of the inflow turbulence intensity on the peak sound pressure level follows an intensity-velocity squared scaling law. A number of length scales and turbulence intensities exist which can be measured in the airfoil wake depending on the position at which the measurements are taken. Comparison of experimental and theoretical sound pressure power spectral densities indicates that the initial anisotropy of the inflow turbulence does not invalidate the isotropic turbulence assumption made in noise prediction models as long as measured turbulence intensities and length scales are used.

  20. Mobile Autonomous Humanoid Assistant

    Science.gov (United States)

    Diftler, M. A.; Ambrose, R. O.; Tyree, K. S.; Goza, S. M.; Huber, E. L.

    2004-01-01

    A mobile autonomous humanoid robot is assisting human co-workers at the Johnson Space Center with tool handling tasks. This robot combines the upper body of the National Aeronautics and Space Administration (NASA)/Defense Advanced Research Projects Agency (DARPA) Robonaut system with a Segway(TradeMark) Robotic Mobility Platform yielding a dexterous, maneuverable humanoid perfect for aiding human co-workers in a range of environments. This system uses stereo vision to locate human team mates and tools and a navigation system that uses laser range and vision data to follow humans while avoiding obstacles. Tactile sensors provide information to grasping algorithms for efficient tool exchanges. The autonomous architecture utilizes these pre-programmed skills to form human assistant behaviors. The initial behavior demonstrates a robust capability to assist a human by acquiring a tool from a remotely located individual and then following the human in a cluttered environment with the tool for future use.

  1. Autonomous single camera exploration

    OpenAIRE

    Vidal-Calleja, Teresa A.; Sanfeliu, Alberto; Andrade-Cetto, J.

    2006-01-01

    In this paper we present an active exploration strategy for a mobile robot navigating in 3D. The aim is to control a moving robot that autonomously builds a visual feature map while at the same time optimises its localisation in this map. The technique chooses the most appropriate commands maximising the information gain between prior states and measurements, while performing 6DOF bearing only SLAM at video rate. Maximising the mutual information helps the vehicle avoid ill-conditioned measur...

  2. Autonomous Underwater Vehicle control

    OpenAIRE

    Vidal Morató, Jordi; Gomáriz Castro, Spartacus; Manuel Lázaro, Antonio

    2005-01-01

    In this paper the system control design stages for an autonomous underwater vehicle are presented. The vehicle must be able to sail on sea surface, following a path without losing its route and once a position is reached, a dive following a perpendicular path to the surface is carried out. A two level system control are proposed. The primary level will control the navigation of the vehicle where a linear controllers are proposed. Whereas in secondary level guidance system, collision system, s...

  3. The autonomous acoustic buoy

    OpenAIRE

    Pellicer, Francisco; Reitsma, Robert; Agüera, Joaquín; Marinas, Alexandra

    2013-01-01

    The Acoustic Buoy is a project between the Laboratory of Applied Bioacoustics (LAB) and the Universitat Politècnica de Catalunya (UPC). In areas that the human activities produce high noise levels, such as oil exploration or construction, there is a need to monitor the environment for the presence of cetaceans. Another need is for fishing, to prevent endangered species from being killed. This can be done with an Autonomous Acoustic Buoy (AAB). Mooring or anchoring at to the seaflo...

  4. Mobile Intelligent Autonomous Systems

    OpenAIRE

    Jitendra R. Raol; Ajith Gopal

    2010-01-01

    Mobile intelligent autonomous systems (MIAS) is a fast emerging research area. Although it can be regarded as a general R&D area, it is mainly directed towards robotics. Several important subtopics within MIAS research are:(i) perception and reasoning, (ii) mobility and navigation,(iii) haptics and teleoperation, (iv) image fusion/computervision, (v) modelling of manipulators, (vi) hardware/software architectures for planning and behaviour learning leadingto robotic architecture, (vii) ve...

  5. Nature's Autonomous Oscillators

    Science.gov (United States)

    Mayr, H. G.; Yee, J.-H.; Mayr, M.; Schnetzler, R.

    2012-01-01

    Nonlinearity is required to produce autonomous oscillations without external time dependent source, and an example is the pendulum clock. The escapement mechanism of the clock imparts an impulse for each swing direction, which keeps the pendulum oscillating at the resonance frequency. Among nature's observed autonomous oscillators, examples are the quasi-biennial oscillation and bimonthly oscillation of the Earth atmosphere, and the 22-year solar oscillation. The oscillations have been simulated in numerical models without external time dependent source, and in Section 2 we summarize the results. Specifically, we shall discuss the nonlinearities that are involved in generating the oscillations, and the processes that produce the periodicities. In biology, insects have flight muscles, which function autonomously with wing frequencies that far exceed the animals' neural capacity; Stretch-activation of muscle contraction is the mechanism that produces the high frequency oscillation of insect flight, discussed in Section 3. The same mechanism is also invoked to explain the functioning of the cardiac muscle. In Section 4, we present a tutorial review of the cardio-vascular system, heart anatomy, and muscle cell physiology, leading up to Starling's Law of the Heart, which supports our notion that the human heart is also a nonlinear oscillator. In Section 5, we offer a broad perspective of the tenuous links between the fluid dynamical oscillators and the human heart physiology.

  6. Trigeminal autonomic cephalalgias.

    Science.gov (United States)

    Eller, M; Goadsby, P J

    2016-01-01

    The trigeminal autonomic cephalalgias (TACs) are a group of primary headache disorders characterised by lateralized symptoms: prominent headache and ipsilateral cranial autonomic features, such as conjunctival injection, lacrimation and rhinorrhea. The TACs are: cluster headache (CH), paroxysmal hemicrania (PH), short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT)/short-lasting neuralgiform headache attacks with cranial autonomic features (SUNA) and hemicrania continua (HC). Their diagnostic criteria are outlined in the International Classification of Headache Disorders, third edition-beta (ICHD-IIIb). These conditions are distinguished by their attack duration and frequency, as well as response to treatment. HC is continuous and by definition responsive to indomethacin. The main differential when considering this headache is chronic migraine. Other TACs are remarkable for their short duration and must be distinguished from other short-lasting painful conditions, such as trigeminal neuralgia and primary stabbing headache. Cluster headache is characterised by exquisitely painful attacks that occur in discrete episodes lasting 15-180 min a few times a day. In comparison, PH occurs more frequently and is of shorter duration, and like HC is responsive to indomethacin. SUNCT/SUNA is the shortest duration and highest frequency TAC; attacks can occur over a hundred times every day. PMID:24888770

  7. Jam avoidance with autonomous systems

    OpenAIRE

    Tordeux, Antoine; Lassarre, Sylvain

    2015-01-01

    Many car-following models are developed for jam avoidance in highways. Two mechanisms are used to improve the stability: feedback control with autonomous models and increasing of the interaction within cooperative ones. In this paper, we compare the linear autonomous and collective optimal velocity (OV) models. We observe that the stability is significantly increased by adding predecessors in interaction with collective models. Yet autonomous and collective approaches are close when the speed...

  8. Chemical Specification of Autonomic Systems

    OpenAIRE

    Banâtre, Jean-Pierre; Fradet, Pascal; Radenac, Yann

    2004-01-01

    Autonomic computing provides a vision of information systems allowing self-management of many predefined properties. Such systems take care of their own behavior and of their interactions with other components without any external intervention. One of the major challenges concerns the expression of properties and constraints of autonomic systems. We believe that the {\\em chemical programming paradigm} (represented here by the Gamma formalism) is well-suited to the specification of autonomic s...

  9. Catecholamines and diabetic autonomic neuropathy

    DEFF Research Database (Denmark)

    Hilsted, J

    1995-01-01

    plasma catecholamine measurements is not due to changes in the clearance of catecholamines in diabetic autonomic neuropathy. The physiological responses to infused adrenaline and to noradrenaline are enhanced, for noradrenaline mainly cardiovascular responses. Adrenoceptors (alpha and beta adrenoceptors......In diabetic patients with autonomic neuropathy plasma noradrenaline concentration, used as an index of sympathetic nervous activity, is low. This decrease is, however, only found in patients with a long duration of diabetes with clinically severe autonomic neuropathy. This apparent insensitivity of...

  10. Robotics and Autonomous Systems Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides an environment for developing and evaluating intelligent software for both actual and simulated autonomous vehicles. Laboratory computers provide...

  11. Jam avoidance with autonomous systems

    CERN Document Server

    Tordeux, Antoine

    2016-01-01

    Many car-following models are developed for jam avoidance in highways. Two mechanisms are used to improve the stability: feedback control with autonomous models and increasing of the interaction within cooperative ones. In this paper, we compare the linear autonomous and collective optimal velocity (OV) models. We observe that the stability is significantly increased by adding predecessors in interaction with collective models. Yet autonomous and collective approaches are close when the speed difference term is taking into account. Within the linear OV models tested, the autonomous models including speed difference are sufficient to maximise the stability.

  12. Collaborating with Autonomous Agents

    Science.gov (United States)

    Trujillo, Anna C.; Cross, Charles D.; Fan, Henry; Hempley, Lucas E.; Motter, Mark A.; Neilan, James H.; Qualls, Garry D.; Rothhaar, Paul M.; Tran, Loc D.; Allen, B. Danette

    2015-01-01

    With the anticipated increase of small unmanned aircraft systems (sUAS) entering into the National Airspace System, it is highly likely that vehicle operators will be teaming with fleets of small autonomous vehicles. The small vehicles may consist of sUAS, which are 55 pounds or less that typically will y at altitudes 400 feet and below, and small ground vehicles typically operating in buildings or defined small campuses. Typically, the vehicle operators are not concerned with manual control of the vehicle; instead they are concerned with the overall mission. In order for this vision of high-level mission operators working with fleets of vehicles to come to fruition, many human factors related challenges must be investigated and solved. First, the interface between the human operator and the autonomous agent must be at a level that the operator needs and the agents can understand. This paper details the natural language human factors e orts that NASA Langley's Autonomy Incubator is focusing on. In particular these e orts focus on allowing the operator to interact with the system using speech and gestures rather than a mouse and keyboard. With this ability of the system to understand both speech and gestures, operators not familiar with the vehicle dynamics will be able to easily plan, initiate, and change missions using a language familiar to them rather than having to learn and converse in the vehicle's language. This will foster better teaming between the operator and the autonomous agent which will help lower workload, increase situation awareness, and improve performance of the system as a whole.

  13. Autonomous packaging robot

    OpenAIRE

    Vo, Van Thanh

    2010-01-01

    The objective of the autonomous packaging robot application is to replace manual product packaging in food industry with a fully automatic robot. The objective is achieved by using the combination of machine vision, central computer, sensors, microcontroller and a typical ABB robot. The method is to equip the robot with different sensors: camera as “eyes” of robot, distance sensor and microcontroller as “sense of touch” of the robot, central computer as “brain” of the robot. Because the ro...

  14. Autonomous component carrier selection

    DEFF Research Database (Denmark)

    Garcia, Luis Guilherme Uzeda; Pedersen, Klaus; Mogensen, Preben

    2009-01-01

    in local areas, basing our study case on LTE-Advanced. We present extensive network simulation results to demonstrate that a simple and robust interference management scheme, called autonomous component carrier selection allows each cell to select the most attractive frequency configuration; improving...... management and efficient system operation. Due to the expected large number of user-deployed cells, centralized network planning becomes unpractical and new scalable alternatives must be sought. In this article, we propose a fully distributed and scalable solution to the interference management problem...

  15. Autonomous mobile robot teams

    Science.gov (United States)

    Agah, Arvin; Bekey, George A.

    1994-01-01

    This paper describes autonomous mobile robot teams performing tasks in unstructured environments. The behavior and the intelligence of the group is distributed, and the system does not include a central command base or leader. The novel concept of the Tropism-Based Cognitive Architecture is introduced, which is used by the robots in order to produce behavior transforming their sensory information to proper action. The results of a number of simulation experiments are presented. These experiments include worlds where the robot teams must locate, decompose, and gather objects, and defend themselves against hostile predators, while navigating around stationary and mobile obstacles.

  16. 75 FR 22510 - Airworthiness Directives; Eurocopter France (ECF) Model EC120B Helicopters

    Science.gov (United States)

    2010-04-29

    ... a main rotor blade, and subsequent loss of control of the helicopter. EASA, the airworthiness... helicopters of the same type design, the FAA issued EAD 2010-05-51. The AD requires, at specified intervals... affect the controllability and structural integrity of the helicopter. Therefore, inspecting the...

  17. 77 FR 20518 - Airworthiness Directives; Agusta S.p.A. Helicopters

    Science.gov (United States)

    2012-04-05

    ... helicopters, the possibility exists, due to part number commonality between the rotor blade type designs, that....A. (Agusta) Model AB412 helicopters with certain tail rotor blades (blades) installed. This AD... advises that Rotor Blades Inc. (RBI) informed Bell Helicopter Textron Inc. (BHTI) about four incidents...

  18. 76 FR 66209 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Model S-92A Helicopters

    Science.gov (United States)

    2011-10-26

    ... the Sikorsky Model S-92A helicopters. This proposal would require inspecting each tail rotor blade... develop on other helicopters of the same type design. Therefore, the proposed AD would require inspecting... helicopters, tail rotor blade assembly (blade), part numbers (P/N) 92170-11000-044, -045, and - 046, with...

  19. 75 FR 69858 - Airworthiness Directives; Eurocopter France (Eurocopter) Model AS332L2 Helicopters

    Science.gov (United States)

    2010-11-16

    ... power to the main rotor system, and subsequent loss of control of the helicopter. DATES: This AD becomes... or develop on other Model AS332L2 helicopters of the same type design. There are no products of this... costs of compliance since there are no helicopters of this type design on the U.S. Registry....

  20. Helicopter Parenting: The Effect of an Overbearing Caregiving Style on Peer Attachment and Self-Efficacy

    Science.gov (United States)

    van Ingen, Daniel J.; Freiheit, Stacy R.; Steinfeldt, Jesse A.; Moore, Linda L.; Wimer, David J.; Knutt, Adelle D.; Scapinello, Samantha; Roberts, Amber

    2015-01-01

    Helicopter parenting, an observed phenomenon on college campuses, may adversely affect college students. The authors examined how helicopter parenting is related to self-efficacy and peer relationships among 190 undergraduate students ages 16 to 28 years. Helicopter parenting was associated with low self-efficacy, alienation from peers, and a lack…

  1. Application of Computational Fluid Dynamics in the problems of determining the aerodynamic characteristics of the helicopter

    OpenAIRE

    Andrei Batrakov; Lyaisan Garipova; Aleksandr Kysumov; George Barakos

    2014-01-01

    In this article, computational Fluid Dynamics is used to study the complex interactions between the rotor and fuselage of the helicopter. Helicopter flows have been under investigation using isolated fuselage models, actuator disks as well as complete rotor-fuselage configurations. The paper highlights the flow detail that can be available to modern helicopter engineers equipped with modern software and computer clusters.

  2. Towards autonomous vehicular clouds

    Directory of Open Access Journals (Sweden)

    Stephan Olariu

    2011-09-01

    Full Text Available The dawn of the 21st century has seen a growing interest in vehicular networking and its myriad potential applications. The initial view of practitioners and researchers was that radio-equipped vehicles could keep the drivers informed about potential safety risks and increase their awareness of road conditions. The view then expanded to include access to the Internet and associated services. This position paper proposes and promotes a novel and more comprehensive vision namely, that advances in vehicular networks, embedded devices and cloud computing will enable the formation of autonomous clouds of vehicular computing, communication, sensing, power and physical resources. Hence, we coin the term, autonomous vehicular clouds (AVCs. A key feature distinguishing AVCs from conventional cloud computing is that mobile AVC resources can be pooled dynamically to serve authorized users and to enable autonomy in real-time service sharing and management on terrestrial, aerial, or aquatic pathways or theaters of operations. In addition to general-purpose AVCs, we also envision the emergence of specialized AVCs such as mobile analytics laboratories. Furthermore, we envision that the integration of AVCs with ubiquitous smart infrastructures including intelligent transportation systems, smart cities and smart electric power grids will have an enormous societal impact enabling ubiquitous utility cyber-physical services at the right place, right time and with right-sized resources.

  3. Nemesis Autonomous Test System

    Science.gov (United States)

    Barltrop, Kevin J.; Lee, Cin-Young; Horvath, Gregory A,; Clement, Bradley J.

    2012-01-01

    A generalized framework has been developed for systems validation that can be applied to both traditional and autonomous systems. The framework consists of an automated test case generation and execution system called Nemesis that rapidly and thoroughly identifies flaws or vulnerabilities within a system. By applying genetic optimization and goal-seeking algorithms on the test equipment side, a "war game" is conducted between a system and its complementary nemesis. The end result of the war games is a collection of scenarios that reveals any undesirable behaviors of the system under test. The software provides a reusable framework to evolve test scenarios using genetic algorithms using an operation model of the system under test. It can automatically generate and execute test cases that reveal flaws in behaviorally complex systems. Genetic algorithms focus the exploration of tests on the set of test cases that most effectively reveals the flaws and vulnerabilities of the system under test. It leverages advances in state- and model-based engineering, which are essential in defining the behavior of autonomous systems. It also uses goal networks to describe test scenarios.

  4. Learning for Autonomous Navigation

    Science.gov (United States)

    Angelova, Anelia; Howard, Andrew; Matthies, Larry; Tang, Benyang; Turmon, Michael; Mjolsness, Eric

    2005-01-01

    Robotic ground vehicles for outdoor applications have achieved some remarkable successes, notably in autonomous highway following (Dickmanns, 1987), planetary exploration (1), and off-road navigation on Earth (1). Nevertheless, major challenges remain to enable reliable, high-speed, autonomous navigation in a wide variety of complex, off-road terrain. 3-D perception of terrain geometry with imaging range sensors is the mainstay of off-road driving systems. However, the stopping distance at high speed exceeds the effective lookahead distance of existing range sensors. Prospects for extending the range of 3-D sensors is strongly limited by sensor physics, eye safety of lasers, and related issues. Range sensor limitations also allow vehicles to enter large cul-de-sacs even at low speed, leading to long detours. Moreover, sensing only terrain geometry fails to reveal mechanical properties of terrain that are critical to assessing its traversability, such as potential for slippage, sinkage, and the degree of compliance of potential obstacles. Rovers in the Mars Exploration Rover (MER) mission have got stuck in sand dunes and experienced significant downhill slippage in the vicinity of large rock hazards. Earth-based off-road robots today have very limited ability to discriminate traversable vegetation from non-traversable vegetation or rough ground. It is impossible today to preprogram a system with knowledge of these properties for all types of terrain and weather conditions that might be encountered.

  5. Terfenol-D driven flaps for helicopter vibration reduction

    Science.gov (United States)

    Fenn, Ralph C.; Downer, James R.; Bushko, Dariusz A.; Gondhalekar, Vijay; Ham, Norman D.

    1996-02-01

    The utility of helicopter aviation is limited by the high vibration levels caused by the interaction of each rotor blade with the wake of preceding blades. Existing full-blade actuation using a swashplate has various problems such as insufficient bandwidth, limitations in the number of harmonics controlled, high maintenance, and lack of spanwise lift variation. These problems are avoided by the proposed flap operated, individual blade control system, which uses magnetostrictive actuation technology. Terfenol-D actuation has many advantages over competing technologies such as hydraulic systems, electric motors, and piezoelectric elements. These benefits include all-electric operation, simplicity and reliability, low mass, low voltage, and insensitivity to centripetal acceleration. A blade mounted Terfenol-D actuator was developed for the high-weight-penalty helicopter application. The optimum coil to Terfenol-D volume ratio was derived that gives the highest mechanical power output for a small actuator envelope and mass. A fixed ability to dissipate coil resistive losses is assumed. The magnetostrictive actuation system will weigh less than 1% of gross vehicle weight, and use only 0.7% of cruise power. Other required subsystems of the vibration reduction system are available from commercial sources or are described in the literature. Helicopter vibration reduction greater than 90% is predicted because of superior actuator performance and individual blade control. This magnetostrictive actuator technology will also produce future helicopter systems having lower noise and higher performance. Such advances will significantly improve the utility and competitiveness of helicopters for civilian and military transportation.

  6. A Newly Adopted Helicopter Platform for Geophysical and Remote Sensing

    Science.gov (United States)

    Meyer, Uwe

    2014-05-01

    The Federal Institute for Geosciences and Natural Resources in Hannover owns a Sikorsky S-76B helicopter for geophysical and remote sensing airborne surveys. This platform has been completely refurbished and in parts newly designed to be fit for easy installations of complex geophysical instruments underneath, upon and within the helicopter. The airborne platform is equipped with a modern basic navigation equipment consisting of several GNSS antennae, state of the art inertial navigation systems, laser altimeter and video camera systems. Different other modules can be added to the helicopter as a state of the art gamma spectrometer, a laser scanner, airborne gravity meters etc. within the cabin. Moreover, external sensing systems as a photogrammetric camera, infraread camera or optional mulitspectral systems can be installed on the outer skin of the cabin. Different kinds of bird systems towed underneath the helicopter can be hooked up using standard cabling, glas fibres or wireless LAN. Available birds are equipped for frequency domain electromagnetics or gradient magnetics (IPHT Jena & Supracon, Jena). Besides, large georadar systems can be installed as well. The helicopter is able as well to carry TEM-gear or system in development. Main survey targets are groundwater systems, mineral deposits and natural hazards.

  7. A VORTEX MODEL OF A HELICOPTER ROTOR

    Directory of Open Access Journals (Sweden)

    Valentin BUTOESCU

    2009-06-01

    Full Text Available A vortex model of a helicopter rotor is presented. Each blade of the rotor has three degrees of freedom: flapping, lagging and feathering. The motions after each degree of freedom are also known for all blades. The blade is modelled as a thin vortex surface. The wakes are free fluid surfaces. A system of five equations are obtained: the first one is the integral equation of the lifting surface (rotor, the next three describe the wakes motion, and the last one relates the vortex strength on the wakes and the variation of vorticity on the rotor. A numerical solution of this system is presented. To avoid the singularities that can occur due to the complexity of vortex system, a desingularized model of the vortex core was adopted. A Mathcad worksheet containing the method has been written.The original contribution of the work. The calculation method of the motion of the wakes free vortex system, the development of the vortex cores in time and a new method to approximate the aerodynamic influence of remoted wake regions.

  8. Modeling Aerodynamically Generated Sound of Helicopter Rotors

    Science.gov (United States)

    Brentner, Kenneth S.; Farassat, F.

    2002-01-01

    A great deal of progress has been made in the modeling of aerodynamically generated sound of rotors over the past decade. Although the modeling effort has focused on helicopter main rotors, the theory is generally valid for a wide range of rotor configurations. The Ffowcs Williams Hawkings (FW-H) equation has been the foundation for much of the development. The monopole and dipole source terms of the FW-H equation account for the thickness and loading noise, respectively. Bladevortex-interaction noise and broadband noise are important types of loading noise, hence much research has been directed toward the accurate modeling of these noise mechanisms. Both subsonic and supersonic quadrupole noise formulations have been developed for the prediction of high-speed impulsive noise. In an effort to eliminate the need to compute the quadrupole contribution, the FW-H equation has also been utilized on permeable surfaces surrounding all physical noise sources. Comparisons of the Kirchhoff formulation for moving surfaces with the FW-H equation have shown that the Kirchhoff formulation for moving surfaces can give erroneous results for aeroacoustic problems. Finally, significant progress has been made incorporating the rotor noise models into full vehicle noise prediction tools.

  9. Yaw Motion Cues in Helicopter Simulation

    Science.gov (United States)

    Schroeder, Jeffrey A.; Johnson, Walter W.

    1996-01-01

    A piloted simulation that examined the effects of yaw motion cues on pilot-vehicle performance, pilot workload, and pilot motion perception was conducted on the NASA Ames Vertical Motion Simulator. The vehicle model that was used represented an AH-64 helicopter. Three tasks were performed in which only combinations of vehicle yaw and vertical displacement were allowed. The commands issued to the motion platform were modified to present the following four motion configurations for a pilot located forward of the center of rotation: (1) only the linear translations, (2) only the angular rotation, (3) both the linear translations and the angular rotation, and (4) no motion. The objective data indicated that pilot-vehicle performance was reduced and the necessary control activity increased when linear motion was removed; however, the lack of angular rotation did not result in a measured degradation for almost all cases. Also, pilots provided subjective assessments of their compensation required, the motion fidelity, and their judgment of whether or not linear or rotational cockpit motion was present. Ratings of compensation and fidelity were affected only by linear acceleration, and the rotational motion had no significant impact. Also, when only linear motion was present, pilots typically reported the presence of rotation. Thus, linear acceleration cues, not yaw rotational cues, appear necessary to simulate hovering flight.

  10. Condition Monitoring for Helicopter Data. Appendix A

    Science.gov (United States)

    Wen, Fang; Willett, Peter; Deb, Somnath

    2000-01-01

    In this paper the classical "Westland" set of empirical accelerometer helicopter data is analyzed with the aim of condition monitoring for diagnostic purposes. The goal is to determine features for failure events from these data, via a proprietary signal processing toolbox, and to weigh these according to a variety of classification algorithms. As regards signal processing, it appears that the autoregressive (AR) coefficients from a simple linear model encapsulate a great deal of information in a relatively few measurements; it has also been found that augmentation of these by harmonic and other parameters can improve classification significantly. As regards classification, several techniques have been explored, among these restricted Coulomb energy (RCE) networks, learning vector quantization (LVQ), Gaussian mixture classifiers and decision trees. A problem with these approaches, and in common with many classification paradigms, is that augmentation of the feature dimension can degrade classification ability. Thus, we also introduce the Bayesian data reduction algorithm (BDRA), which imposes a Dirichlet prior on training data and is thus able to quantify probability of error in an exact manner, such that features may be discarded or coarsened appropriately.

  11. Helicopter EMS: Research Endpoints and Potential Benefits

    Directory of Open Access Journals (Sweden)

    Stephen H. Thomas

    2012-01-01

    Full Text Available Patients, EMS systems, and healthcare regions benefit from Helicopter EMS (HEMS utilization. This article discusses these benefits in terms of specific endpoints utilized in research projects. The endpoint of interest, be it primary, secondary, or surrogate, is important to understand in the deployment of HEMS resources or in planning further HEMS outcomes research. The most important outcomes are those which show potential benefits to the patients, such as functional survival, pain relief, and earlier ALS care. Case reports are also important “outcomes” publications. The benefits of HEMS in the rural setting is the ability to provide timely access to Level I or Level II trauma centers and in nontrauma, interfacility transport of cardiac, stroke, and even sepsis patients. Many HEMS crews have pharmacologic and procedural capabilities that bring a different level of care to a trauma scene or small referring hospital, especially in the rural setting. Regional healthcare and EMS system's benefit from HEMS by their capability to extend the advanced level of care throughout a region, provide a “backup” for areas with limited ALS coverage, minimize transport times, make available direct transport to specialized centers, and offer flexibility of transport in overloaded hospital systems.

  12. Expanded Perspectives on Autonomous Learners

    Science.gov (United States)

    Oxford, Rebecca L.

    2015-01-01

    This paper explores two general perspectives on autonomous learners: psychological and sociocultural. These perspectives introduce a range of theoretically grounded facets of autonomous learners, facets such as the self-regulated learner, the emotionally intelligent learner, the self-determined learner, the mediated learner, the socioculturally…

  13. Application of smart materials to helicopter rotor active control

    Science.gov (United States)

    Straub, Friedrich K.; Ealey, Mark A.; Schetky, Lawrence M.

    1997-05-01

    Helicopter design is limited by the compromise inherent in meeting hover and forward flight requirements, and the unsteady environment encountered in forward flight. Active control of helicopter rotors using smart material, in-blade actuation can overcome these barriers and provide substantial reductions in noise and vibrations and improved performance. The present study covers the blade/actuator integration and actuator development for a full scale system to demonstrate active control of noise and vibrations as well as inflight blade tracking on the MD Explorer helicopter. A piezoelectric multilayer stack actuator, driving a trailing edge flap, is used for active control. A shape memory alloy torsion actuator, driving a trailing edge trim tab, is used for inflight tracking. Overall, this DARPA sponsored program entails the design, development, and fabrication of the full scale active control rotor system. If successful, an entry in the NASA Ames 40 X 80 foot wind tunnel and flight tests are planned for a follow on program.

  14. Aerodynamic analysis of a helicopter fuselage with rotating rotor head

    Science.gov (United States)

    Reß, R.; Grawunder, M.; Breitsamter, Ch.

    2015-06-01

    The present paper describes results of wind tunnel experiments obtained during a research programme aimed at drag reduction of the fuselage of a twin engine light helicopter configuration. A 1 : 5 scale model of a helicopter fuselage including a rotating rotor head and landing gear was investigated in the low-speed wind tunnel A of Technische Universität a München (TUM). The modelled parts of the helicopter induce approxiu mately 80% of the total parasite drag thus forming a major potential for shape optimizations. The present paper compares results of force and moment measurements of a baseline configuration and modified variants with an emphasis on the aerodynamic drag, lift, and yawing moment coefficients.

  15. Flap motion of helicopter rotors with novel, dynamic stall model

    Directory of Open Access Journals (Sweden)

    Han Wei

    2016-07-01

    Full Text Available In this paper, a nonlinear flapping equation for large inflow angles and flap angles is established by analyzing the aerodynamics of helicopter blade elements. In order to obtain a generalized flap equation, the Snel stall model was first applied to determine the lift coefficient of the helicopter rotor. A simulation experiment for specific airfoils was then conducted to verify the effectiveness of the Snel stall model as it applies to helicopters. Results show that the model requires no extraneous parameters compared to the traditional stall model and is highly accurate and practically applicable. Based on the model, the relationship between the flapping angle and the angle of attack was analyzed, as well as the advance ratio under the dynamic stall state.

  16. Evaluation of ride quality prediction methods for operational military helicopters

    Science.gov (United States)

    Leatherwood, J. D.; Clevenson, S. A.; Hollenbaugh, D. D.

    1984-01-01

    The results of a simulator study conducted to compare and validate various ride quality prediction methods for use in assessing passenger/crew ride comfort within helicopters are presented. Included are results quantifying 35 helicopter pilots' discomfort responses to helicopter interior noise and vibration typical of routine flights, assessment of various ride quality metrics including the NASA ride comfort model, and examination of possible criteria approaches. Results of the study indicated that crew discomfort results from a complex interaction between vibration and interior noise. Overall measures such as weighted or unweighted root-mean-square acceleration level and A-weighted noise level were not good predictors of discomfort. Accurate prediction required a metric incorporating the interactive effects of both noise and vibration. The best metric for predicting crew comfort to the combined noise and vibration environment was the NASA discomfort index.

  17. Cognitive perspectives on map displays for helicopter flight

    Science.gov (United States)

    Harwood, Kelly

    1989-01-01

    Currently accessible technologies are providing entirely new display concepts for enhancing helicopter navigation. Yet the effectiveness of such displays depends on the extent to which they are configured according to principles from research on human performance. Computer generated map displays in the present study were configured according to previous research on maps, navigational problem solving, and spatial cognition in large scale environments. Interest centered on the representation of different spatial relationships that would best support helicopter navigational problem solving. One map display emphasized the global relationships between objects in the environment. The other map showed the pilot's relationship to objects as he traveled through the environment. Twenty skilled pilots used the maps to complete several navigational tasks that occurred within a realistic simulation program tailored for helicopter navigation. Findings indicate that the type of task and mode of flight (low level or Nap of the Earth (NOE)) are important determinants of map display effectiveness.

  18. Evolutionary Autonomous Health Monitoring System (EAHMS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For supporting NASA's Robotics, Tele-Robotics and Autonomous Systems Roadmap, we are proposing the "Evolutionary Autonomous Health Monitoring System" (EAHMS) for...

  19. Autonomous Gaussian Decomposition

    CERN Document Server

    Lindner, Robert R; Murray, Claire E; Stanimirović, Snežana; Babler, Brian L; Heiles, Carl; Hennebelle, Patrick; Goss, W M; Dickey, John

    2014-01-01

    We present a new algorithm, named Autonomous Gaussian Decomposition (AGD), for automatically decomposing spectra into Gaussian components. AGD uses derivative spectroscopy and machine learning to provide optimized guesses for the number of Gaussian components in the data, and also their locations, widths, and amplitudes. We test AGD and find that it produces results comparable to human-derived solutions on 21cm absorption spectra from the 21cm SPectral line Observations of Neutral Gas with the EVLA (21-SPONGE) survey. We use AGD with Monte Carlo methods to derive the HI line completeness as a function of peak optical depth and velocity width for the 21-SPONGE data, and also show that the results of AGD are stable against varying observational noise intensity. The autonomy and computational efficiency of the method over traditional manual Gaussian fits allow for truly unbiased comparisons between observations and simulations, and for the ability to scale up and interpret the very large data volumes from the up...

  20. Autonomous Flying Controls Testbed

    Science.gov (United States)

    Motter, Mark A.

    2005-01-01

    The Flying Controls Testbed (FLiC) is a relatively small and inexpensive unmanned aerial vehicle developed specifically to test highly experimental flight control approaches. The most recent version of the FLiC is configured with 16 independent aileron segments, supports the implementation of C-coded experimental controllers, and is capable of fully autonomous flight from takeoff roll to landing, including flight test maneuvers. The test vehicle is basically a modified Army target drone, AN/FQM-117B, developed as part of a collaboration between the Aviation Applied Technology Directorate (AATD) at Fort Eustis,Virginia and NASA Langley Research Center. Several vehicles have been constructed and collectively have flown over 600 successful test flights.

  1. Mobile Intelligent Autonomous Systems

    Directory of Open Access Journals (Sweden)

    Jitendra R. Raol

    2010-01-01

    Full Text Available Mobile intelligent autonomous systems (MIAS is a fast emerging research area. Although it can be regarded as a general R&D area, it is mainly directed towards robotics. Several important subtopics within MIAS research are:(i perception and reasoning, (ii mobility and navigation,(iii haptics and teleoperation, (iv image fusion/computervision, (v modelling of manipulators, (vi hardware/software architectures for planning and behaviour learning leadingto robotic architecture, (vii vehicle-robot path and motionplanning/control, (viii human-machine interfaces for interaction between humans and robots, and (ix application of artificial neural networks (ANNs, fuzzy logic/systems (FLS,probabilistic/approximate reasoning (PAR, Bayesian networks(BN and genetic algorithms (GA to the above-mentioned problems. Also, multi-sensor data fusion (MSDF playsvery crucial role at many levels of the data fusion process:(i kinematic fusion (position/bearing tracking, (ii imagefusion (for scene recognition, (iii information fusion (forbuilding world models, and (iv decision fusion (for tracking,control actions. The MIAS as a technology is useful for automation of complex tasks, surveillance in a hazardousand hostile environment, human-assistance in very difficultmanual works, medical robotics, hospital systems, autodiagnosticsystems, and many other related civil and military systems. Also, other important research areas for MIAScomprise sensor/actuator modelling, failure management/reconfiguration, scene understanding, knowledge representation, learning and decision-making. Examples ofdynamic systems considered within the MIAS would be:autonomous systems (unmanned ground vehicles, unmannedaerial vehicles, micro/mini air vehicles, and autonomousunder water vehicles, mobile/fixed robotic systems, dexterousmanipulator robots, mining robots, surveillance systems,and networked/multi-robot systems, to name a few.Defence Science Journal, 2010, 60(1, pp.3-4,

  2. Wavy-Planform Helicopter Blades Make Less Noise

    Science.gov (United States)

    Brooks, Thomas F.

    2004-01-01

    Wavy-planform rotor blades for helicopters have been investigated for the first time in an effort to reduce noise. Two of the main sources of helicopter noise are blade/vortex interaction (BVI) and volume displacement. (The noise contributed by volume displacement is termed thickness noise.) The reduction in noise generated by a wavyplanform blade, relative to that generated by an otherwise equivalent straight-planform blade, affects both main sources: (1) the BVI noise is reduced through smoothing and defocusing of the aerodynamic loading on the blade and (2) the thickness noise is reduced by reducing gradients of thickness with respect to listeners on the ground.

  3. Interior noise reduction in a large civil helicopter

    Science.gov (United States)

    Howlett, J. T.; Clevenson, S. A.; Rypf, J. A.; Snyder, W. J.

    1977-01-01

    The results of an evaluation of the effectiveness of current noise reduction technology in attaining acceptable levels of interior noise in a large (about 20,000 kg) passenger-carrying helicopter are presented. The helicopter studied is a modified CH-53A with a specially designed, acoustically treated passenger cabin. The acoustic treatment reduced the average A-weighted interior noise levels from 115 db to 87 db. The study suggests selected improvements in the acoustic treatment which could result in additional reduction in cabin noise levels. The resulting levels would be only slightly greater than the interior noise levels of current narrow-body jet transports.

  4. Important Scaling Parameters for Testing Model-Scale Helicopter Rotors

    Science.gov (United States)

    Singleton, Jeffrey D.; Yeager, William T., Jr.

    1998-01-01

    An investigation into the effects of aerodynamic and aeroelastic scaling parameters on model scale helicopter rotors has been conducted in the NASA Langley Transonic Dynamics Tunnel. The effect of varying Reynolds number, blade Lock number, and structural elasticity on rotor performance has been studied and the performance results are discussed herein for two different rotor blade sets at two rotor advance ratios. One set of rotor blades were rigid and the other set of blades were dynamically scaled to be representative of a main rotor design for a utility class helicopter. The investigation was con-densities permits the acquisition of data for several Reynolds and Lock number combinations.

  5. Digital flight control design for a tandem-rotor helicopter

    Science.gov (United States)

    Stengel, R. F.; Broussard, J. R.; Berry, P. W.

    1977-01-01

    Methods and results in the continuing development of a digital flight control system (DFCS) for the CH-47B helicopter are examined. The helicopter is the research vehicle for the NASA VTOL Approach and Landing Technology (VALT) Program. It is equipped with comprehensive equipment for the investigation of navigation, guidance, and control requirements for future VTOL aircraft. Two control modes (attitude-command and velocity-command) are implemented, and each mode provides 'Type 1' response to guidance commands. DFCS design is based upon optimal estimation and control methods, which are found to provide flexible and efficient means for defining practical digital control systems.

  6. The Effect of Helicopter Rotors on GPS Signal Reception

    Science.gov (United States)

    Brodin, Gary; Cooper, John; Walsh, David; Stevens, Jeff

    2005-09-01

    This paper presents the results of an experiment to investigate the impact of helicopter rotor blades on GPS signal reception. An offshore transport helicopter was equipped with a measurement system including a TSO-C129 compliant receiver and a custom research receiver. GPS signals passing through rotor discs of this aircraft were found to suffer a reduction in received signal strength, leading to potential navigation and RAIM availability concerns. The phenomenon will vary between installations and receiver types. Test procedures to identify the occurrence of the phenomenon in operational GPS installations are presented, together with possible in-service monitoring programs to assess the impact on the navigation function.

  7. Helicopter rotor dynamics and aeroelasticity - Some key ideas and insights

    Science.gov (United States)

    Friedmann, Peretz P.

    1990-01-01

    Four important current topics in helicopter rotor dynamics and aeroelasticity are discussed: (1) the role of geometric nonlinearities in rotary-wing aeroelasticity; (2) structural modeling, free vibration, and aeroelastic analysis of composite rotor blades; (3) modeling of coupled rotor/fuselage areomechanical problems and their active control; and (4) use of higher-harmonic control for vibration reduction in helicopter rotors in forward flight. The discussion attempts to provide an improved fundamental understanding of the current state of the art. In this way, future research can be focused on problems which remain to be solved instead of producing marginal improvements on problems which are already understood.

  8. Identification of Helicopter Rigid Body Dynamics from Flight Data.

    Directory of Open Access Journals (Sweden)

    Jatinder Singh

    1998-01-01

    Full Text Available This paper discusses helicopter modelling and identification related aspects. By applying thesystem identification methodology, longitudinal and lateral-directional rigid body helicopter dynamics are identified from flight data. Aerodynamic parameters from single input excitation as wellas multimanoeuver evaluation are estimated utilising output-error approach. The formulatedmathematical models yield adequate fit to measured time histories. Results obtained from the proof-of-match for model validation indicate that the identified derivatives can satisfactorily predictlongitudinal dynamics to a given arbitrary input. It is further demonstrated for the present study thatlateral body dynamics can be adequately predicted by including cross-coupling terms in the estimation model.

  9. Civil helicopter noise assessment study Boeing-Vertol model 347. [recommendations for reduction of helicopter noise levels

    Science.gov (United States)

    Hinterkeuser, E. G.; Sternfeld, H., Jr.

    1974-01-01

    A study was conducted to forecast the noise restrictions which may be imposed on civil transport helicopters in the 1975-1985 time period. Certification and community acceptance criteria were predicted. A 50 passenger tandem rotor helicopter based on the Boeing-Vertol Model 347 was studied to determine the noise reductions required, and the means of achieving them. Some of the important study recommendations are: (1) certification limits should be equivalent to 95 EPNdb at data points located at 500 feet to each side of the touchdown/takeoff point, and 1000 feet from this point directly under the approach and departure flight path. (2) community acceptance should be measured as Equivalent Noise Level (Leq), based on dBA, with separate limits for day and night operations, and (3) in order to comply with the above guidelines, the Model 347 helicopter will require studies and tests leading to several modifications.

  10. Bell Helicopter Advanced Rotocraft Transmission (ART) program

    Science.gov (United States)

    Henry, Zachary S.

    1995-06-01

    Future rotorcraft transmissions require key emerging material and component technologies using advanced and innovative design practices in order to meet the requirements for a reduced weight to power ratio, a decreased noise level, and a substantially increased reliability. The specific goals for the future rotorcraft transmission when compared with a current state-of-the-art transmission (SOAT) are: (1) a 25 percent weight reduction; (2) a 10 dB reduction in the transmitted noise level; and (3) a system reliability of 5000 hours mean-time-between-removal (MTBR) for the transmission. This report summarizes the work conducted by Bell Helicopter Textron, Inc. to achieve these goals under the Advanced Rotorcraft Transmission (ART) program from 1988 to 1995. The reference aircraft selected by BHTI for the ART program was the Tactical Tiltrotor which is a 17,000 lb gross weight aircraft. A tradeoff study was conducted comparing the ART with a Selected SOAT. The results showed the ART to be 29 percent lighter and up to 13 dB quieter with a calculated MTBR in excess of 5000 hours. The results of the following high risk component and material tests are also presented: (1) sequential meshing high contact ratio planetary with cantilevered support posts; (2) thin dense chrome plated M50 NiL double row spherical roller planetary bearings; (3) reduced kinematic error and increased bending strength spiral bevel gears; (4) high temperature WE43 magnesium housing evaluation and coupon corrosion tests; (5) flexure fatigue tests of precision forged coupons simulating precision forged gear teeth; and (6) flexure fatigue tests of plasma carburized coupons simulating plasma carburized gear teeth.

  11. Stroboscope Controller for Imaging Helicopter Rotors

    Science.gov (United States)

    Jensen, Scott; Marmie, John; Mai, Nghia

    2004-01-01

    A versatile electronic timing-and-control unit, denoted a rotorcraft strobe controller, has been developed for use in controlling stroboscopes, lasers, video cameras, and other instruments for capturing still images of rotating machine parts especially helicopter rotors. This unit is designed to be compatible with a variety of sources of input shaftangle or timing signals and to be capable of generating a variety of output signals suitable for triggering instruments characterized by different input-signal specifications. It is also designed to be flexible and reconfigurable in that it can be modified and updated through changes in its control software, without need to change its hardware. Figure 1 is a block diagram of the rotorcraft strobe controller. The control processor is a high-density complementary metal oxide semiconductor, singlechip 8-bit microcontroller. It is connected to a 32K x 8 nonvolatile static random-access memory (RAM) module. Also connected to the control processor is a 32K 8 electrically programmable read-only-memory (EPROM) module, which is used to store the control software. Digital logic support circuitry is implemented in a field-programmable gate array (FPGA). A 240 x 128-dot, 40- character 16-line liquid-crystal display (LCD) module serves as a graphical user interface; the user provides input through a 16-key keypad mounted next to the LCD. A 12-bit digital-to-analog converter (DAC) generates a 0-to-10-V ramp output signal used as part of a rotor-blade monitoring system, while the control processor generates all the appropriate strobing signals. Optocouplers are used to isolate all input and output digital signals, and optoisolators are used to isolate all analog signals. The unit is designed to fit inside a 19-in. (.48-cm) rack-mount enclosure. Electronic components are mounted on a custom printed-circuit board (see Figure 2). Two power-conversion modules on the printedcircuit board convert AC power to +5 VDC and 15 VDC, respectively.

  12. Cybersecurity for aerospace autonomous systems

    Science.gov (United States)

    Straub, Jeremy

    2015-05-01

    High profile breaches have occurred across numerous information systems. One area where attacks are particularly problematic is autonomous control systems. This paper considers the aerospace information system, focusing on elements that interact with autonomous control systems (e.g., onboard UAVs). It discusses the trust placed in the autonomous systems and supporting systems (e.g., navigational aids) and how this trust can be validated. Approaches to remotely detect the UAV compromise, without relying on the onboard software (on a potentially compromised system) as part of the process are discussed. How different levels of autonomy (task-based, goal-based, mission-based) impact this remote characterization is considered.

  13. Revolutionary Concepts for Helicopter Noise Reduction: SILENT Program

    Science.gov (United States)

    Edwards, Bryan; Cox, Charles; Booth, Earl R., Jr. (Technical Monitor)

    2002-01-01

    As part of a NASA initiative to reduce helicopter main rotor noise, a Phase 1 study has been performed of candidate noise reduction concepts. Both conventional and novel design technologies have been analyzed that reduce the community impact of helicopter operations. In this study the noise reduction potential and design implications are assessed for conventional means of noise reduction, e.g., tip speed reduction, tip shapes and airfoil tailoring, and for two innovative design concepts: modulated blade spacing and x-force control. Main rotor designs that incorporate modulated blade spacing are shown to have reduced peak noise levels in most flight operations. X-force control alters the helicopter's force balance whereby the miss distance between main rotor blades and shed vortices can be controlled. This control provides a high potential to mitigate BVI noise radiation. Each concept is evaluated using best practice design and analysis methods, achieving the study's aim to significantly reduce noise with minimal performance degradation and no vibration increase. It is concluded that a SILENT main rotor design, incorporating the modulated blade spacing concept, offers significantly reduced noise levels and the potential of a breakthrough in how a helicopter's sound is perceived and judged. The SILENT rotor represents a definite advancement in the state-of-the-art and is selected as the design concept for demonstration in Phase 2. A Phase 2 Implementation Plan is developed for whirl cage and wind tunnel evaluations of a scaled model SILENT rotor.

  14. A designer's viewpoint: Requirements for reducing helicopter noise

    Science.gov (United States)

    Cohen, E. E.

    1982-01-01

    Functional requirements of helicopter noise reduction are discussed from the work environment point by view, i.e., what conditions must exist before the designer can take aim, without too many restraints, at reducing noise, community demand for noise reduction, regulatory requirements, competition, and penalties are among the topics discussed.

  15. Helicopter Rotor Noise Prediction: Background, Current Status, and Future Direction

    Science.gov (United States)

    Brentner, Kenneth S.

    1997-01-01

    Helicopter noise prediction is increasingly important. The purpose of this viewgraph presentation is to: 1) Put into perspective the recent progress; 2) Outline current prediction capabilities; 3) Forecast direction of future prediction research; 4) Identify rotorcraft noise prediction needs. The presentation includes an historical perspective, a description of governing equations, and the current status of source noise prediction.

  16. Design of helicopter rotor blades for optimum dynamic characteristics

    Science.gov (United States)

    Peters, D. A.; Ko, T.; Korn, A.; Rossow, M. P.

    1985-01-01

    The mass and stiffness distributions for helicopter rotor blades are tailored in such a way to give a predetermined placement of blade natural frequencies. The optimal design is pursued with respect of minimum weight, sufficient inertia, and reasonable dynamic characteristics. Finite element techniques are used as a tool. Rotor types include hingeless, articulated, and teetering.

  17. 78 FR 44043 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-07-23

    ...) Applicability This AD applies to Eurocopter Model EC225LP helicopters with a main rotor hub (MRH) assembly with... discovery of corrosion on the swashplates when the main rotor hub (MRH) assemblies were reconditioned. The... unsafe condition is likely to exist or develop on other products of the same type design. Related...

  18. New design of hingeless helicopter rotor improves stability

    Science.gov (United States)

    Ormiston, R. A.; Bousman, W. G.; Hodges, D. H.; Peters, D. A.

    1975-01-01

    Cantilever blades are attached directly to rotor hub, thereby substantially reducing cost and complexity and increasing reliability of helicopter rotor. Combination of structural flap-lag coupling and pitch-lag coupling provides damping of 6 to 10%, depending on magnitude of coupling parameters.

  19. 78 FR 44045 - Airworthiness Directives; Sikorsky Aircraft Corporation (Sikorsky) Helicopters

    Science.gov (United States)

    2013-07-23

    ... unsafe condition exists and is likely to exist or develop on other helicopters of this same type design... 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034... (P/N) 38023-10374- 041; (2) Main Rotor Hub, P/N 70070-10046-055 and -056; (3) Main Rotor Spindle...

  20. 78 FR 51127 - Airworthiness Directives; Various Restricted Category Helicopters

    Science.gov (United States)

    2013-08-20

    ... unsafe condition exists and is likely to exist or develop on other helicopters of the same type design... Southwest Florida Aviation, Inc. This proposed AD would require inspecting the tail rotor (T/R) cable.... Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034,...

  1. Investigation of Current Methods to Identify Helicopter Gear Health

    Science.gov (United States)

    Dempsey, Paula J.; Lewicki, David G.; Le, Dy D.

    2007-01-01

    This paper provides an overview of current vibration methods used to identify the health of helicopter transmission gears. The gears are critical to the transmission system that provides propulsion, lift and maneuvering of the helicopter. This paper reviews techniques used to process vibration data to calculate conditions indicators (CI's), guidelines used by the government aviation authorities in developing and certifying the Health and Usage Monitoring System (HUMS), condition and health indicators used in commercial HUMS, and different methods used to set thresholds to detect damage. Initial assessment of a method to set thresholds for vibration based condition indicators applied to flight and test rig data by evaluating differences in distributions between comparable transmissions are also discussed. Gear condition indicator FM4 values are compared on an OH58 helicopter during 14 maneuvers and an OH58 transmission test stand during crack propagation tests. Preliminary results show the distributions between healthy helicopter and rig data are comparable and distributions between healthy and damaged gears show significant differences.

  2. 78 FR 22213 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-04-15

    ... Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not affect intrastate aviation in Alaska... France Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for Eurocopter...

  3. 77 FR 36220 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-06-18

    ... ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will... C3 helicopters with a MGB, all part numbers, that was delivered before December 5, 2007, installed on.... (g) Subject Joint Aircraft Service Component (JASC) Code: 6320: Main Rotor Gearbox. Issued in...

  4. 78 FR 63853 - Airworthiness Directives; Eurocopter France (Eurocopter) Helicopters

    Science.gov (United States)

    2013-10-25

    ... Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); ] 3. Will not affect intrastate aviation....00.49 is for non-FAA type certificated military Models AS550A2, C2, C3, and U2 helicopters. EASB No... in Docket No. FAA-2013-0878. (i) Subject Joint Aircraft Service Component (JASC) Code: 6400...

  5. The Computational Electromagnetic Modelling of the CH-146 Griffon Helicopter

    Science.gov (United States)

    Rogers, Sarah Alicia

    Selecting the optimal location for a new antenna on an aircraft is a difficult task. Given the limited space that is available on the fuselage, there maybe only a few available locations from which to choose. The performance of a new antenna is often hindered by nearby structures on the aircraft, which may block or diffract the antenna's desired radiation. In addition, given that there are many other antennas and electronic systems onboard aircraft, potential interference produced by the new antenna must also be considered. The choice of the best antenna location must therefore be based on the careful study of the electromagnetic performance of the antenna at each location. Given that it is unlikely that a new antenna can be physically tested in various locations on an operational aircraft, recourse must be made to computer simulation. In this work, the selection of an appropriate location for a new satellite communication antenna is considered for the CH-146 Griffon helicopter. To this end, a new computer electromagnetic model of the CH-146 Griffon helicopter was created, validated, and used to characterize the helicopter's electromagnetic environment. A commercial computational software called FEKO was subsequently used to calculate the radiation patterns, near-fields, and surface current distribution generated on the helicopter model by a broad-patterned antenna installed at three different locations on the aircraft. A subsequent analysis of the calculated results was then used to determine the best of the three possible placements of the proposed satellite communications antenna.

  6. 78 FR 40956 - Airworthiness Directives; Eurocopter Deutschland (Eurocopter) Helicopters

    Science.gov (United States)

    2013-07-09

    .... The air conditioning compressor is driven by a pulley attached to the rotor brake disc. We received a report of a recent incident where the fasteners attaching the air conditioning compressor pulley to the... helicopters with a Metro Aviation (Metro) vapor-cycle air conditioning kit installed in accordance...

  7. Robust Helicopter Stabilization in the Face of Wind Disturbance

    DEFF Research Database (Denmark)

    A. Danapalasingam, Kumeresan; Leth, John-Josef; la Cour-Harbo, Anders;

    2010-01-01

    helicopter model affected by a wind disturbance is addressed. The wind disturbance is assumed to be a sum of a fixed number of sinusoids with unknown amplitudes, frequencies and phases. An estimate of the disturbance is introduced to be adapted using state measurements for control purposes. A nonlinear...... handling parameter and model uncertainties....

  8. 78 FR 40072 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-07-03

    ...'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not affect... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Eurocopter France... France (Eurocopter) Model AS332C1 and AS332L1 helicopters. This proposed AD would require replacing...

  9. 78 FR 57047 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-09-17

    ... On February 11, 2013, at 78 FR 9634, the Federal Register published our notice of proposed rulemaking... FR 9634, February 11, 2013). FAA's Determination These helicopters have been approved by the aviation... changes are consistent with the intent of the proposals in the NPRM (78 FR 9634, February 11, 2013)...

  10. 77 FR 44118 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-07-27

    ... Order 12866; 2. Is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034...-056-AD; Amendment 39-17133; AD 2012-15-04] RIN 2120-AA64 Airworthiness Directives; Eurocopter France... France (Eurocopter) Model EC155B1 helicopters with a certain automated flight control system...

  11. 78 FR 65871 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2013-11-04

    ..., at 78 FR 33764, the Federal Register published our notice of proposed rulemaking (NPRM), which... NPRM (78 FR 33764, June 5, 2013). FAA's Determination These helicopters have been approved by the... Executive Order 12866; (2) Is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44...

  12. Synthetic vision helicopter flights using high resolution LIDAR terrain data

    Science.gov (United States)

    Sindlinger, A.; Meuter, M.; Barraci, N.; Güttler, M.; Klingauf, U.; Schiefele, J.; Howland, D.

    2006-05-01

    Helicopters are widely used for operations close to terrain such as rescue missions; therefore all-weather capabilities are highly desired. To minimize or even avoid the risk of collision with terrain and obstacles, Synthetic Vision Systems (SVS) could be used to increase situational awareness. In order to demonstrate this, helicopter flights have been performed in the area of Zurich, Switzerland A major component of an SVS is the three-dimensional (3D) depiction of terrain data, usually presented on the primary flight display (PFD). The degree of usability in low level flight applications is a function of the terrain data quality. Today's most precise, large scale terrain data are derived from airborne laser scanning technologies such as LIDAR (light detection and ranging). A LIDAR dataset provided by Swissphoto AG, Zurich with a resolution of 1m was used. The depiction of high resolution terrain data consisting of 1 million elevation posts per square kilometer on a laptop in an appropriate area around the helicopter is challenging. To facilitate the depiction of the high resolution terrain data, it was triangulated applying a 1.5m error margin making it possible to depict an area of 5x5 square kilometer around the helicopter. To position the camera correctly in the virtual scene the SVS had to be supplied with accurate navigation data. Highly flexible and portable measurement equipment which easily could be used in most aircrafts was designed. Demonstration flights were successfully executed in September, October 2005 in the Swiss Alps departing from Zurich.

  13. 77 FR 36216 - Airworthiness Directives; Eurocopter France Helicopters

    Science.gov (United States)

    2012-06-18

    ... ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will... AS355NP helicopters with certain Aerazur emergency flotation gear attachment brackets (brackets) installed. This proposed AD would require an initial and recurring inspection of the brackets for a crack, and...

  14. Aeromechanical Analysis of a Smart Helicopter Rotor in Forward Flight

    Directory of Open Access Journals (Sweden)

    Jacopo Serafini

    2015-02-01

    Full Text Available This paper deals with a smart system integrated into a helicopter blade aimed at giving an anhedral shape to the blade tip region to alleviate the blade-vortex interaction phenomenon that may cause reduced helicopter performance in terms of noise and vibrations. The blade tip morphing is obtained through the joint action of a magneto-rheological fluid (MRF device, a shape-memory alloy ribbons- based (SMA device and a set of concentrated masses properly distributed spanwise. The presence of this smart actuator (particularly the concentrated masses inside the blades modifies the aeromechanical behaviour of the rotor and may be detrimental in terms of hub vibratory loads, pitch control effectiveness and aeroelastic stability. Following a previous literature work concerning with the effectiveness of the smart actuated rotor in hovering conditions, the present paper focuses on the aeromechanical effects due to the inclusion of the smart device in a four-bladed helicopter rotor in forward flight where blade morphing is not needed. Aim of this work is to investigate on the compatibility of the smart system with the required aeromechanical performance of the rotor, highlighting the feasibility of its application on helicopters.

  15. Using Paper Helicopters to Teach Statistical Process Control

    Science.gov (United States)

    Johnson, Danny J.

    2011-01-01

    This hands-on project uses a paper helicopter to teach students how to distinguish between common and special causes of variability when developing and using statistical process control charts. It allows the student to experience a process that is out-of-control due to imprecise or incomplete product design specifications and to discover how the…

  16. 77 FR 63285 - Airworthiness Directives; Brantly International, Inc. Helicopters

    Science.gov (United States)

    2012-10-16

    ... using a 10X power magnifying glass and conducting a tap ] test every 25 hours TIS and a visual... Policies and Procedures (44 FR 11034, February 26, 1979); 3. Will not affect intrastate aviation in Alaska... helicopter during flight. Laboratory analysis concluded that the M/R blade failure was caused by...

  17. Acoustic Helicopter and FW Aircraft Detection and Classification

    NARCIS (Netherlands)

    Koersel, A.C. van

    2001-01-01

    The possibility to detect the passage of aircraft (either propeller or jet) with one or more mechanical wave sensors (acoustic or seismic) is investigated. An existing algorithm-sensor demonstator can detect and classify helicopter targets. In its current form it is developed to reject other targets

  18. Flight Test Guide (Part 61 Revised): Instrument Pilot: Helicopter.

    Science.gov (United States)

    Federal Aviation Administration (DOT), Washington, DC. Flight Standards Service.

    The guide provides an outline of the skills required to pass the flight test for an Instrument Pilot Helicopter Rating under Part 61 (revised) of Federal Aviation Regulations. General procedures for flight tests are described and the following pilot operations outlined: maneuvering by reference to instruments, IFR navigation, instrument…

  19. At Issue: Helicopter Parents and Millennial Students, an Annotated Bibliography

    Science.gov (United States)

    Pricer, Wayne F.

    2008-01-01

    Technological advances have made it easy for parents and children--many of them students--to communicate instantaneously. Devices and technologies such as cell phones, laptops, texting, and e-mail all enable various forms of instant communication. "Helicopter parents" are regarded as very overprotective and overly involved in the affairs of their…

  20. From Self-Flying Helicopters to Classrooms of the Future

    Science.gov (United States)

    Young, Jeffrey R.

    2012-01-01

    On a summer day four years ago, a Stanford University computer-science professor named Andrew Ng held an unusual air show on a field near the campus. His fleet of small helicopter drones flew under computer control, piloted by artificial-intelligence software that could teach itself to fly after watching a human operator. By the end of the day,…

  1. Autonomic Dysregulation in Multiple Sclerosis.

    Science.gov (United States)

    Pintér, Alexandra; Cseh, Domonkos; Sárközi, Adrienn; Illigens, Ben M; Siepmann, Timo

    2015-01-01

    Multiple sclerosis (MS) is a chronic, progressive central neurological disease characterized by inflammation and demyelination. In patients with MS, dysregulation of the autonomic nervous system may present with various clinical symptoms including sweating abnormalities, urinary dysfunction, orthostatic dysregulation, gastrointestinal symptoms, and sexual dysfunction. These autonomic disturbances reduce the quality of life of affected patients and constitute a clinical challenge to the physician due to variability of clinical presentation and inconsistent data on diagnosis and treatment. Early diagnosis and initiation of individualized interdisciplinary and multimodal strategies is beneficial in the management of autonomic dysfunction in MS. This review summarizes the current literature on the most prevalent aspects of autonomic dysfunction in MS and provides reference to underlying pathophysiological mechanisms as well as means of diagnosis and treatment. PMID:26213927

  2. Framework for Autonomous Optimization Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Phoenix Integration and MIT propose to create a novel autonomous optimization tool and application programming interface (API). The API will demonstrate the ability...

  3. Future Autonomous and Automated Systems Testbed Project

    Data.gov (United States)

    National Aeronautics and Space Administration — FAAST is an R/C helicopter platform that is being developed by the Aeroscience and Flight Mechanics Division (EG) as a low-cost, low-risk, hands-on way for...

  4. Autonomous Mission Operations Roadmap

    Science.gov (United States)

    Frank, Jeremy David

    2014-01-01

    As light time delays increase, the number of such situations in which crew autonomy is the best way to conduct the mission is expected to increase. However, there are significant open questions regarding which functions to allocate to ground and crew as the time delays increase. In situations where the ideal solution is to allocate responsibility to the crew and the vehicle, a second question arises: should the activity be the responsibility of the crew or an automated vehicle function? More specifically, we must answer the following questions: What aspects of mission operation responsibilities (Plan, Train, Fly) should be allocated to ground based or vehicle based planning, monitoring, and control in the presence of significant light-time delay between the vehicle and the Earth?How should the allocated ground based planning, monitoring, and control be distributed across the flight control team and ground system automation? How should the allocated vehicle based planning, monitoring, and control be distributed between the flight crew and onboard system automation?When during the mission should responsibility shift from flight control team to crew or from crew to vehicle, and what should the process of shifting responsibility be as the mission progresses? NASA is developing a roadmap of capabilities for Autonomous Mission Operations for human spaceflight. This presentation will describe the current state of development of this roadmap, with specific attention to in-space inspection tasks that crews might perform with minimum assistance from the ground.

  5. Autonomous Gaussian Decomposition

    Science.gov (United States)

    Lindner, Robert R.; Vera-Ciro, Carlos; Murray, Claire E.; Stanimirović, Snežana; Babler, Brian; Heiles, Carl; Hennebelle, Patrick; Goss, W. M.; Dickey, John

    2015-04-01

    We present a new algorithm, named Autonomous Gaussian Decomposition (AGD), for automatically decomposing spectra into Gaussian components. AGD uses derivative spectroscopy and machine learning to provide optimized guesses for the number of Gaussian components in the data, and also their locations, widths, and amplitudes. We test AGD and find that it produces results comparable to human-derived solutions on 21 cm absorption spectra from the 21 cm SPectral line Observations of Neutral Gas with the EVLA (21-SPONGE) survey. We use AGD with Monte Carlo methods to derive the H i line completeness as a function of peak optical depth and velocity width for the 21-SPONGE data, and also show that the results of AGD are stable against varying observational noise intensity. The autonomy and computational efficiency of the method over traditional manual Gaussian fits allow for truly unbiased comparisons between observations and simulations, and for the ability to scale up and interpret the very large data volumes from the upcoming Square Kilometer Array and pathfinder telescopes.

  6. Semantic Web Meets Autonomic Ubicomp

    OpenAIRE

    Belecheanu, R A; Jawaheer, G; Hoskins, A.; McCann, J; Payne, T.

    2004-01-01

    The placement of autonomic systems’ management functionality into a ubiquitous computing environment is a difficult task due to the lack of systems’ resources and the need for ‘intelligence’ to ensure that the system is selfhealing/ organising or configuring. For such systems to adapt to changes to their current environment they need to be able to (re) configure the workflow of their services. In this paper, we propose the ANS, an autonomic middleware for ubicomp devices. We briefly describe ...

  7. Design of Autonomous Gel Actuators

    OpenAIRE

    Shuji Hashimoto; Shingo Maeda; Yusuke Hara; Satoshi Nakamaru

    2011-01-01

    In this paper, we introduce autonomous gel actuators driven by chemical energy. The polymer gels prepared here have cyclic chemical reaction networks. With a cyclic reaction, the polymer gels generate periodical motion. The periodic motion of the gel is produced by the chemical energy of the oscillatory Belouzov-Zhabotinsky (BZ) reaction. We have succeeded in making synthetic polymer gel move autonomously like a living organism. This experimental fact represents the great possibility of the c...

  8. Design of Autonomous Gel Actuators

    Directory of Open Access Journals (Sweden)

    Shuji Hashimoto

    2011-01-01

    Full Text Available In this paper, we introduce autonomous gel actuators driven by chemical energy. The polymer gels prepared here have cyclic chemical reaction networks. With a cyclic reaction, the polymer gels generate periodical motion. The periodic motion of the gel is produced by the chemical energy of the oscillatory Belouzov-Zhabotinsky (BZ reaction. We have succeeded in making synthetic polymer gel move autonomously like a living organism. This experimental fact represents the great possibility of the chemical robot.

  9. Build Autonomic Agents with ABLE

    Institute of Scientific and Technical Information of China (English)

    吴吉义

    2007-01-01

    The IBM Agent Building and Learning Environment(ABLE) provides a lightweight Java~(TM) agent frame- work,a comprehensive JavaBeansTM library of intelligent software components,a set of development and test tools, and an agent platform.After the introduction to ABLE,classes and interfaces in the ABLE agent framework were put forward.At last an autonomic agent that is an ABLE-based architecture for incrementally building autonomic systems was discussed.

  10. Autonomous vertical profiler data management

    Digital Repository Service at National Institute of Oceanography (India)

    Afzulpurkar, S.; Navelkar, G.S.; Desa, E.S.; Madhan, R.; Dabholkar, N.; Prabhudesai, S.P.; Mascarenhas, A.A.M.Q.

    and reduced data �� Ease in operation and one man deployable 2 Fig.1. Autonomous Vertical Profiler Table 1. Autonomous Vertical Profiler Specifications 2. Communication Communication with the AVP is through the satellite modem... Aluminum alloy, Acetal nose & tail cones Propulsion Single DC thruster Electronics 8051 and ARM7 microcontroller based Communication Radio modem (2.4 GHz) & Satellite Transmission (Iridium) GUI Labview based Energy Source Lithium Ion Polymer batteries...

  11. 76 FR 12274 - Special Conditions: Bell Helicopter Textron Canada Limited Model 206B and 206L Series Helicopters...

    Science.gov (United States)

    2011-03-07

    ... 206L series helicopters with the noise certification requirements of 14 CFR part 36. The FAA issues... would include, for example, a slight reduction in safety margins or functional capabilities, a slight..., a significant reduction in safety margins or functional capabilities, a significant increase in...

  12. Results of the flight noise measurement program using a standard and modified SH-3A helicopter

    Science.gov (United States)

    Pegg, R. J.; Henderson, H. R.; Hilton, D. A.

    1973-01-01

    A field noise measurement program has been conducted using both a standard SH-3A helicopter and an SH-3A helicopter modified to reduce external noise levels. Modifications included reducing rotor speed, increasing the number of rotor blades, modifying the blade-tip shapes, and acoustically treating the engine air intakes and exhaust. The purpose of this study was to document the noise characteristics recorded on the ground of each helicopter during flyby, hover, landing, and take-off operations. Based on an analysis of the measured results, the average of the overhead, overall, ontrack noise levels was approximately 4 db lower for the modified helicopter than for the standard helicopter. The improved in-flight noise characteristics, and associated small footprint areas and time durations, were judged to be mainly due to tail-rotor noise reductions. The noise reductions were obtained at the expense of required power increases at airspeeds greater than 70 knots for the modified helicopter.

  13. Extracting radar micro-Doppler signatures of helicopter rotating rotor blades using K-band radars

    Science.gov (United States)

    Chen, Rachel; Liu, Baokun

    2014-06-01

    Helicopter identification has been an attractive topic. In this paper, we applied radar micro-Doppler signatures to identify helicopter. For identifying the type of a helicopter, besides its shape and size, the number of blades, the length of the blade, and the rotation rate of the rotor are important features, which can be estimated from radar micro-Doppler signatures of the helicopter's rotating rotor blades. In our study, K-band CW/FMCW radars are used for collecting returned signals from helicopters. By analyzing radar micro-Doppler signatures, we can estimate the number of blades, the length of the blade, the angular rotation rate of the rotating blade, and other necessary parameters for identifying the type of a helicopter.

  14. Integrated Motion Planning and Autonomous Control Technology for Autonomous ISR Project

    Data.gov (United States)

    National Aeronautics and Space Administration — SSCI and MIT propose to design, implement and test a comprehensive Integrated Mission Planning & Autonomous Control Technology (IMPACT) for Autonomous ISR...

  15. 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

  16. Contributions to the dynamics of helicopters with active rotor controls

    Science.gov (United States)

    Malpica, Carlos A.

    This dissertation presents an aeromechanical closed loop stability and response analysis of a hingeless rotor helicopter with a Higher Harmonic Control (HHC) system for vibration reduction. The analysis includes the rigid body dynamics of the helicopter and blade flexibility. The gain matrix is assumed to be fixed and computed off-line. The discrete elements of the HHC control loop are rigorously modeled, including the presence of two different time scales in the loop. By also formulating the coupled rotor-fuselage dynamics in discrete form, the entire coupled helicopter-HHC system could be rigorously modeled as a discrete system. The effect of the periodicity of the equations of motion is rigorously taken into account by converting the system into an equivalent system with constant coefficients and identical stability properties using a time lifting technique. The most important conclusion of the present study is that the discrete elements in the HHC loop must be modeled in any HHC analysis. Not doing so is unconservative. For the helicopter configuration and HHC structure used in this study, an approximate continuous modeling of the HHC system indicates that the closed loop, coupled helicopter-HHC system remains stable for optimal feedback control configurations which the more rigorous discrete analysis shows can result in closed loop instabilities. The HHC gains must be reduced to account for the loss of gain margin brought about by the discrete elements. Other conclusions of the study are: (i) the HHC is effective in quickly reducing vibrations, at least at its design condition, although the time constants associated with the closed loop transient response indicate closed loop bandwidth to be 1 rad/sec on average, thus overlapping with FCS or pilot bandwidths, and raising the issue of potential interactions; (ii) a linearized model of helicopter dynamics is adequate for HHC design, as long as the periodicity of the system is correctly taken into account, i

  17. Autonomic control of the eye

    Science.gov (United States)

    McDougal, David H.; Gamlin, Paul D.

    2016-01-01

    The autonomic nervous system influences numerous ocular functions. It does this by way of parasympathetic innervation from postganglionic fibers that originate from neurons in the ciliary and pterygopalatine ganglia, and by way of sympathetic innervation from postganglionic fibers that originate from neurons in the superior cervical ganglion. Ciliary ganglion neurons project to the ciliary body and the sphincter pupillae muscle of the iris to control ocular accommodation and pupil constriction, respectively. Superior cervical ganglion neurons project to the dilator pupillae muscle of the iris to control pupil dilation. Ocular blood flow is controlled both via direct autonomic influences on the vasculature of the optic nerve, choroid, ciliary body, and iris, as well as via indirect influences on retinal blood flow. In mammals, this vasculature is innervated by vasodilatory fibers from the pterygopalatine ganglion, and by vasoconstrictive fibers from the superior cervical ganglion. Intraocular pressure is regulated primarily through the balance of aqueous humor formation and outflow. Autonomic regulation of ciliary body blood vessels and the ciliary epithelium is an important determinant of aqueous humor formation; autonomic regulation of the trabecular meshwork and episcleral blood vessels is an important determinant of aqueous humor outflow. These tissues are all innervated by fibers from the pterygopalatine and superior cervical ganglia. In addition to these classical autonomic pathways, trigeminal sensory fibers exert local, intrinsic influences on many of these regions of the eye, as well as on some neurons within the ciliary and pterygopalatine ganglia. PMID:25589275

  18. Autonomous Landing on Moving Platforms

    KAUST Repository

    Mendoza Chavez, Gilberto

    2016-08-01

    This thesis investigates autonomous landing of a micro air vehicle (MAV) on a nonstationary ground platform. Unmanned aerial vehicles (UAVs) and micro air vehicles (MAVs) are becoming every day more ubiquitous. Nonetheless, many applications still require specialized human pilots or supervisors. Current research is focusing on augmenting the scope of tasks that these vehicles are able to accomplish autonomously. Precise autonomous landing on moving platforms is essential for self-deployment and recovery of MAVs, but it remains a challenging task for both autonomous and piloted vehicles. Model Predictive Control (MPC) is a widely used and effective scheme to control constrained systems. One of its variants, output-feedback tube-based MPC, ensures robust stability for systems with bounded disturbances under system state reconstruction. This thesis proposes a MAV control strategy based on this variant of MPC to perform rapid and precise autonomous landing on moving targets whose nominal (uncommitted) trajectory and velocity are slowly varying. The proposed approach is demonstrated on an experimental setup.

  19. Lidar Sensors for Autonomous Landing and Hazard Avoidance

    Science.gov (United States)

    Amzajerdian, Farzin; Petway, Larry B.; Hines, Glenn D.; Roback, Vincent E.; Reisse, Robert A.; Pierrottet, Diego F.

    2013-01-01

    Lidar technology will play an important role in enabling highly ambitious missions being envisioned for exploration of solar system bodies. Currently, NASA is developing a set of advanced lidar sensors, under the Autonomous Landing and Hazard Avoidance (ALHAT) project, aimed at safe landing of robotic and manned vehicles at designated sites with a high degree of precision. These lidar sensors are an Imaging Flash Lidar capable of generating high resolution three-dimensional elevation maps of the terrain, a Doppler Lidar for providing precision vehicle velocity and altitude, and a Laser Altimeter for measuring distance to the ground and ground contours from high altitudes. The capabilities of these lidar sensors have been demonstrated through four helicopter and one fixed-wing aircraft flight test campaigns conducted from 2008 through 2012 during different phases of their development. Recently, prototype versions of these landing lidars have been completed for integration into a rocket-powered terrestrial free-flyer vehicle (Morpheus) being built by NASA Johnson Space Center. Operating in closed-loop with other ALHAT avionics, the viability of the lidars for future landing missions will be demonstrated. This paper describes the ALHAT lidar sensors and assesses their capabilities and impacts on future landing missions.

  20. Optimal autorotational descent of a helicopter with control and state inequality constraints

    Science.gov (United States)

    Lee, Allan Y.

    1990-01-01

    A point-mass model of the OH-58A helicopter has been used to ascertain the autorotation profiles which minimize helicopter impact velocity while remaining within the bounds of the main rotor's collective pitch and angular speed. The optimal control strategies are comparable to those employed by pilots in autorotational landings. It is noted that a possibility exists for the reduction of the height-sink rate restriction zone of OH-58A helicopters, using optimal energy-management techniques.

  1. ROTOR TURBULENCE INFLUENCE ON HELICOPTER FLIGHTS IN HIGH URBAN BUILT-UP AREA

    Directory of Open Access Journals (Sweden)

    Tomasz Łusiak

    2013-03-01

    Full Text Available The paper provides a discussion of the influence of turbulence in the areaa of high urban buildings or in vicinity of fire on safety of helicopter flights. The analysis was conducted using Ansys Fluent software. All the threats considering helicopter flight, landing and hovering in such an environment were shown. As objects of this research helicopter types: W3-A Sokół, W3-A Głuszec and Robinson R-44 were used.

  2. Application of Computational Fluid Dynamics in the problems of determining the aerodynamic characteristics of the helicopter

    Directory of Open Access Journals (Sweden)

    Andrei Batrakov

    2014-04-01

    Full Text Available In this article, computational Fluid Dynamics is used to study the complex interactions between the rotor and fuselage of the helicopter. Helicopter flows have been under investigation using isolated fuselage models, actuator disks as well as complete rotor-fuselage configurations. The paper highlights the flow detail that can be available to modern helicopter engineers equipped with modern software and computer clusters.

  3. Autonomous underwater riser inspection tool

    Energy Technology Data Exchange (ETDEWEB)

    Camerini, Claudio; Marnet, Robson [Petrobras SA, (Brazil); Freitas, Miguel; Von der Weid, Jean Pierre [CPTI/PUC-Rio, Rio de Janeiro, (Brazil); Artigas Lander, Ricardo [EngeMOVI, Curitiba, (Brazil)

    2010-07-01

    The detection of damage on the riser is a serious concern for pipeline companies. Visual examinations by remotely operated vehicle (ROV) are presently carried out to detect the defects but this process has limitations and is expensive. This paper presents the development of a new tool to ensure autonomous underwater riser inspection (AURI) that uses the riser itself for guidance. The AURI, which is autonomous in terms of control and power supply, is equipped with several cameras that perform a complete visual inspection of the riser with 100 % coverage of the external surface of the riser. The paper presents the detailed characteristics of the first AURI prototype, describes its launching procedure and provides the preliminary test results from pool testing. The results showed that the AURI is a viable system for autonomous riser inspection. Offshore tests on riser pipelines are scheduled to be performed shortly.

  4. Autonomic Function in Neurodegenerative Diseases

    DEFF Research Database (Denmark)

    Sørensen, Gertrud Laura; Jennum, Poul Jørgen

    2013-01-01

    involving brain stem areas, which is consistent with the Braak hypothesis. In the narcolepsy patients, it was shown that a reduced HRR to arousals was primarily predicted by hypocretin deficiency in both rapid-eye-movement (REM) and non-REM sleep, independent of cataplexy and other factors. The results......, which includes the cardiac centre and controls autonomic functions, and therefore autonomic dysfunction may be experienced early in the disease course. Sleep disturbances are also common non-motor complications of PD, and therefore PD patients undergo polysomnography at the Danish Center for Sleep...... narcolepsy patients on autonomic function and on the sleep transition rate. The results showed an attenuated heart rate response (HRR) in PD patients compared to controls and early PD (iRBD patients). Also iRBD patients had an attenuated HRR compared to control subjects, and the method to measure the HRR may...

  5. Design of an Optimal Fuzzy Controller for Hover mode of Finite Degree of Freedom Unmanned Helicopter

    Directory of Open Access Journals (Sweden)

    Sina Ameli

    2012-01-01

    Full Text Available A helicopter has nonlinear dynamics and it’s a multivariable system. A helicopter is an unstable plant with high level of interaction between some of its variables. Therefore, controlling a helicopter is very difficult and to control it we must use special strategies. A fuzzy controller is a kind of nonlinear controller. It can control a plant without a mathematical model or a poor model. In this paper, we designed a fuzzy controller for an unmanned helicopter with finite degree of freedom. The fuzzy controller is designed based on optimal controller strategies. The proposed method has a better performance than state feedback optimal controller.

  6. Reynolds Number Effects on Helicopter Rotor Hub Flow

    Science.gov (United States)

    Reich, David; Willits, Steve; Schmitz, Sven

    2015-11-01

    The 12 inch diameter water tunnel at the Pennsylvania State University Applied Research Laboratory was used with the objective of quantifying effects of Reynolds number scaling on drag and shed wake of model helicopter rotor hub flows. Hub diameter-based Reynolds numbers ranged from 1.06 million to 2.62 million. Measurements included steady and unsteady hub drag, as well as Particle Image Velocimetry. Results include time-averaged, phase-averaged, and spectral analysis of the drag and wake flow-field. A strong dependence of steady and unsteady drag on Reynolds number was noted, alluding to the importance of adequate Reynolds scaling for model helicopter rotor hubs that exhibit interaction between various bluff bodies.

  7. Feasibility study of a superconducting motor for electrical helicopter propulsion

    Science.gov (United States)

    Simons, C. A. B. A. E.; Sanabria-Walter, C.; Polinder, H.

    2014-05-01

    During the past decades, superconducting electrical machines have become more suitable to replace conventional iron based designs, because of their lower weight and higher torque density. These properties make them good candidates for use in More Electric Aircraft (MEA). Especially helicopter propulsion systems could benefit from the increased performance. This paper describes the feasibility study of a superconducting motor to be used for helicopter propulsion as part of a More Electric Aircraft (MEA). For this, the armature, field windings and cryostat are designed, aiming at meeting the difficult specifications. Since superconductors have virtually no electrical resistance when cooled down below a certain critical temperature, they can be used to build high field and low weight coils for electrical machines. Especially the possibility to not use iron can make the superconducting motor lighter with a higher power density compared with conventional Permanent Magnet (PM) motors.

  8. Lift capability prediction for helicopter rotor blade-numerical evaluation

    Science.gov (United States)

    Rotaru, Constantin; Cîrciu, Ionicǎ; Luculescu, Doru

    2016-06-01

    The main objective of this paper is to describe the key physical features for modelling the unsteady aerodynamic effects found on helicopter rotor blade operating under nominally attached flow conditions away from stall. The unsteady effects were considered as phase differences between the forcing function and the aerodynamic response, being functions of the reduced frequency, the Mach number and the mode forcing. For a helicopter rotor, the reduced frequency at any blade element can't be exactly calculated but a first order approximation for the reduced frequency gives useful information about the degree of unsteadiness. The sources of unsteady effects were decomposed into perturbations to the local angle of attack and velocity field. The numerical calculus and graphics were made in FLUENT and MAPLE soft environments. This mathematical model is applicable for aerodynamic design of wind turbine rotor blades, hybrid energy systems optimization and aeroelastic analysis.

  9. Simulation and Analysis of Crashworthiness of Fuel Tank for Helicopters

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Crashworthiness requirement of fuel tanks is one of the important requirements in helicopter designs. The relations among the protection frame, textile layer and rubber layer of the fuel tank are introduced. Two appropriate FE models are established, one is for an uncovered helicopter fuel tank without protection frame, and the other is for fuel tank with protection frame. The dynamic responses of the two types of fuel tanks impinging on the ground with velocities of 17.3 m/s are numerically simulated for the purpose of analyzing energy-absorbing capabilities of the textile layer and protection frame. The feasibility of the current crashworthiness design of the fuel tank is examined though comparing the dynamic response behaviors of the two fuel tanks.

  10. Application of differential GPS to civil helicopter terminal guidance

    Science.gov (United States)

    Denaro, R. P.

    1984-01-01

    NASA is conducting a research program to evaluate differential Global Positioning System (GPS) concepts for civil helicopter navigation. It is pointed out that the civil helicopter community will probably be an early user of GPS because of the unique mission operations in areas where precise navigation aids are not available. Applications with very demanding accuracy requirements are related to remote area search and rescue, offshore oil platform approach, remote area precision landing, and other precise navigation operations. Differential GPS appears to provide a solution for meeting the accuracy requirements involved in the considered operations. The present investigation is concerned with results obtained in three areas studied in connection with the conducted research program. Attention is given to mission-tailored satellite selection, a satellite selection algorithm concept, satellite selection algorithm simulation results, and differential GPS ground station design.

  11. A new approach to helicopter rotor blade research instrumentation

    Science.gov (United States)

    Knight, V. H., Jr.

    1978-01-01

    A rotor-blade-mounted telemetry instrumentation system developed and used in flight tests by the NASA/Langley Research Center is described. The system uses high-speed digital techniques to acquire research data from miniature pressure transducers on advanced rotor airfoils which are flight tested using an AH-1G helicopter. The system employs microelectronic PCM multiplexer-digitizer stations located remotely on the blade and in a hub-mounted metal canister. The electronics contained in the canister digitizes up to 16 sensors, formats this data with serial PCM data from the remote stations, and transmits the data from the canister which is above the plane of the rotor. Data is transmitted over an RF link to the ground for real-time monitoring and to the helicopter fuselage for tape recording.

  12. Experimental studies in system identification of helicopter rotor dynamics

    Science.gov (United States)

    Mckillip, Robert, Jr.

    1988-01-01

    Recent experiments investigating the system identification of helicopter rotor dynamics are described. The identification makes use of a two-pass procedure that estimates the rotor dynamic states prior to estimation of the dynamic equation parameters. Estimation of the rotor states is made possible through use of the predictive information contained in blade-mounted accelerometers combined with a specialized processing scheme utilizing these signals. Descriptions of the experimental hardware and the system identification technique are given, as well as implementation issues for using the procedure on other similarly instrumented rotor blades. Finally, comparisons with other identification techniques using the same data are presented. It is demonstrated that the approach is an attractive one for measurement of a helicopter rotor's dynamic behavior.

  13. Feasibility study of a superconducting motor for electrical helicopter propulsion

    International Nuclear Information System (INIS)

    During the past decades, superconducting electrical machines have become more suitable to replace conventional iron based designs, because of their lower weight and higher torque density. These properties make them good candidates for use in More Electric Aircraft (MEA). Especially helicopter propulsion systems could benefit from the increased performance. This paper describes the feasibility study of a superconducting motor to be used for helicopter propulsion as part of a More Electric Aircraft (MEA). For this, the armature, field windings and cryostat are designed, aiming at meeting the difficult specifications. Since superconductors have virtually no electrical resistance when cooled down below a certain critical temperature, they can be used to build high field and low weight coils for electrical machines. Especially the possibility to not use iron can make the superconducting motor lighter with a higher power density compared with conventional Permanent Magnet (PM) motors.

  14. Sliding mode tracking control for miniature unmanned helicopters

    Directory of Open Access Journals (Sweden)

    Xian Bin

    2015-02-01

    Full Text Available A sliding mode control design for a miniature unmanned helicopter is presented. The control objective is to let the helicopter track some predefined velocity and yaw trajectories. A new sliding mode control design method is developed based on a linearized dynamic model. In order to facilitate the control design, the helicopter’s dynamic model is divided into two subsystems, such as the longitudinal-lateral and the heading-heave subsystem. The proposed controller employs sliding mode control technique to compensate for the immeasurable flapping angles’ dynamic effects and external disturbances. The global asymptotic stability (GAS of the closed-loop system is proved by the Lyapunov based stability analysis. Numerical simulations demonstrate that the proposed controller can achieve superior tracking performance compared with the proportional-integral-derivative (PID and linear-quadratic regulator (LQR cascaded controller in the presence of wind gust disturbances.

  15. Fluid mechanics mechanisms in the stall process of helicopters

    Science.gov (United States)

    Young, W. H., Jr.

    1981-01-01

    Recent experimental results from airfoils in the Mach number, Reynolds number, or reduced frequency ranges typical of helicopter rotor blades have identified the most influential flow mechanisms in the dynamic stall process. The importance of secondary shed vortices, downstream wake action, and the flow in the separated region is generally acknowledged but poorly understood. By means of surface pressure cross-correlations and flow field measurements in static stall, several new hypotheses have been generated. It is proposed that vortex shedding may be caused by acoustic disturbances propagating forward in the lower (pressure) surface boundary layer, that wake closure is a misnomer, and that the shed vortex leaves a trail of vorticity that forms a turbulent free shear layer. The known dynamic stall flow mechanisms are reviewed and the potential importance of recently proposed and hypothetical flow phenomena with respect to helicopter blade aeroelastic response are assessed.

  16. Helicopter optimal descent and landing after power loss

    Science.gov (United States)

    Johnson, W.

    1977-01-01

    An optimal control solution is obtained for the descent and landing of a helicopter after the loss of power in level flight. The model considers the helicopter vertical velocity, horizontal velocity, and rotor speed; and it includes representations of ground effect, rotor inflow time lag, pilot reaction time, rotor stall, and the induced velocity curve in the vortex ring state. The control (rotor thrust magnitude and direction) required to minimize the vertical and horizontal velocity at contact with the ground is obtained using nonlinear optimal control theory. It is found that the optimal descent after power loss in hover is a purely vertical flight path. Good correlation, even quantitatively, is found between the calculations and (non-optimal) flight test results.

  17. A helicopter-borne 8-channel FFT scatterometer

    Science.gov (United States)

    Hallikainen, Martti; Hyyppa, Juha; Tares, Teemu; Ahola, Pekka; Toikka, Martti

    A helicopter-borne dual-frequency FM-CW scatterometer and related methods for target identification and analysis are described. The scatterometer can measure the backscatter from a target with a range resolution of one meter. This is accomplished by performing the fast Fourier transform (FFT) to the received time-domain signal. The measurement is made simultaneously at eight channels (VV, HH, HV, and VH modes of polarization at 5.4 GHz and 9.8 GHz). The scatterometer measures the radar return spectrum for eight channels in 16.6 ms, which corresponds to an along-track distance of 0.33 m for the helicopter speed of 20 m/s.

  18. Helicopter derivative identification from analytic models and flight test data

    Science.gov (United States)

    Molusis, J. H.; Briczinski, S.

    1974-01-01

    Recent results of stability derivative identification from helicopter analytic models and flight test data are presented. Six and nine degree-of-freedom (DOF) linear models are identified from an analytic nonlinear helicopter simulation using a least square technique. The identified models are compared with the convectional partial differentiation method for obtaining derivatives to form the basis for interpretation of derivatives identified from flight data. Six degree-of-freedom models are identified from CH-53A and CH-54B flight data, using an extended Kalman filter modified to process several maneuvers simultaneously. The a priori derivative estimate is obtained by optimal filtering of the data and then using a least square method. The results demonstrate that a six DOF identified model is sufficient to determine the low frequency modes of motion, but a nine DOF rotor/body model is necessary for proper representation of short-term response.

  19. Identification and stochastic control of helicopter dynamic modes

    Science.gov (United States)

    Molusis, J. A.; Bar-Shalom, Y.

    1983-01-01

    A general treatment of parameter identification and stochastic control for use on helicopter dynamic systems is presented. Rotor dynamic models, including specific applications to rotor blade flapping and the helicopter ground resonance problem are emphasized. Dynamic systems which are governed by periodic coefficients as well as constant coefficient models are addressed. The dynamic systems are modeled by linear state variable equations which are used in the identification and stochastic control formulation. The pure identification problem as well as the stochastic control problem which includes combined identification and control for dynamic systems is addressed. The stochastic control problem includes the effect of parameter uncertainty on the solution and the concept of learning and how this is affected by the control's duel effect. The identification formulation requires algorithms suitable for on line use and thus recursive identification algorithms are considered. The applications presented use the recursive extended kalman filter for parameter identification which has excellent convergence for systems without process noise.

  20. Discerning non-autonomous dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Clemson, Philip T.; Stefanovska, Aneta, E-mail: aneta@lancaster.ac.uk

    2014-09-30

    Structure and function go hand in hand. However, while a complex structure can be relatively safely broken down into the minutest parts, and technology is now delving into nanoscales, the function of complex systems requires a completely different approach. Here the complexity clearly arises from nonlinear interactions, which prevents us from obtaining a realistic description of a system by dissecting it into its structural component parts. At best, the result of such investigations does not substantially add to our understanding or at worst it can even be misleading. Not surprisingly, the dynamics of complex systems, facilitated by increasing computational efficiency, is now readily tackled in the case of measured time series. Moreover, time series can now be collected in practically every branch of science and in any structural scale—from protein dynamics in a living cell to data collected in astrophysics or even via social networks. In searching for deterministic patterns in such data we are limited by the fact that no complex system in the real world is autonomous. Hence, as an alternative to the stochastic approach that is predominantly applied to data from inherently non-autonomous complex systems, theory and methods specifically tailored to non-autonomous systems are needed. Indeed, in the last decade we have faced a huge advance in mathematical methods, including the introduction of pullback attractors, as well as time series methods that cope with the most important characteristic of non-autonomous systems—their time-dependent behaviour. Here we review current methods for the analysis of non-autonomous dynamics including those for extracting properties of interactions and the direction of couplings. We illustrate each method by applying it to three sets of systems typical for chaotic, stochastic and non-autonomous behaviour. For the chaotic class we select the Lorenz system, for the stochastic the noise-forced Duffing system and for the non-autonomous

  1. Autonomous Home Automated Hexapod Robot

    Directory of Open Access Journals (Sweden)

    Addanki Purna Ramesh,

    2010-12-01

    Full Text Available This paper focuses on design and implementation of six legged robot that is capable of monitoring and performing house hold works independently. The Autonomous Home Automated Hexapod is developed with three AT89C52 microcontrollers which functions as brain of the robot to which all operating functions of each module are chronologically programmed in it. The legs of the robot were developed with 2 servo motors to provide two degree for each leg. Several additional sensors like TSOP1738 (IR, RF transmitter andreceiver, DS1307 (Real Time Clock have been embedded into robot in modular form to make it work autonomously.

  2. Progress towards autonomous, intelligent systems

    Science.gov (United States)

    Lum, Henry; Heer, Ewald

    1987-01-01

    An aggressive program has been initiated to develop, integrate, and implement autonomous systems technologies starting with today's expert systems and evolving to autonomous, intelligent systems by the end of the 1990s. This program includes core technology developments and demonstration projects for technology evaluation and validation. This paper discusses key operational frameworks in the content of systems autonomy applications and then identifies major technological challenges, primarily in artificial intelligence areas. Program content and progress made towards critical technologies and demonstrations that have been initiated to achieve the required future capabilities in the year 2000 era are discussed.

  3. Discerning non-autonomous dynamics

    International Nuclear Information System (INIS)

    Structure and function go hand in hand. However, while a complex structure can be relatively safely broken down into the minutest parts, and technology is now delving into nanoscales, the function of complex systems requires a completely different approach. Here the complexity clearly arises from nonlinear interactions, which prevents us from obtaining a realistic description of a system by dissecting it into its structural component parts. At best, the result of such investigations does not substantially add to our understanding or at worst it can even be misleading. Not surprisingly, the dynamics of complex systems, facilitated by increasing computational efficiency, is now readily tackled in the case of measured time series. Moreover, time series can now be collected in practically every branch of science and in any structural scale—from protein dynamics in a living cell to data collected in astrophysics or even via social networks. In searching for deterministic patterns in such data we are limited by the fact that no complex system in the real world is autonomous. Hence, as an alternative to the stochastic approach that is predominantly applied to data from inherently non-autonomous complex systems, theory and methods specifically tailored to non-autonomous systems are needed. Indeed, in the last decade we have faced a huge advance in mathematical methods, including the introduction of pullback attractors, as well as time series methods that cope with the most important characteristic of non-autonomous systems—their time-dependent behaviour. Here we review current methods for the analysis of non-autonomous dynamics including those for extracting properties of interactions and the direction of couplings. We illustrate each method by applying it to three sets of systems typical for chaotic, stochastic and non-autonomous behaviour. For the chaotic class we select the Lorenz system, for the stochastic the noise-forced Duffing system and for the non-autonomous

  4. Gas House Autonomous System Monitoring

    Science.gov (United States)

    Miller, Luke; Edsall, Ashley

    2015-01-01

    Gas House Autonomous System Monitoring (GHASM) will employ Integrated System Health Monitoring (ISHM) of cryogenic fluids in the High Pressure Gas Facility at Stennis Space Center. The preliminary focus of development incorporates the passive monitoring and eventual commanding of the Nitrogen System. ISHM offers generic system awareness, adept at using concepts rather than specific error cases. As an enabler for autonomy, ISHM provides capabilities inclusive of anomaly detection, diagnosis, and abnormality prediction. Advancing ISHM and Autonomous Operation functional capabilities enhances quality of data, optimizes safety, improves cost effectiveness, and has direct benefits to a wide spectrum of aerospace applications.

  5. Intelligent, autonomous systems in space

    Science.gov (United States)

    Lum, H.; Heer, E.

    1988-01-01

    The Space Station is expected to be equipped with intelligent, autonomous capabilities; to achieve and incorporate these capabilities, the required technologies need to be identitifed, developed and validated within realistic application scenarios. The critical technologies for the development of intelligent, autonomous systems are discussed in the context of a generalized functional architecture. The present state of this technology implies that it be introduced and applied in an evolutionary process which must start during the Space Station design phase. An approach is proposed to accomplish design information acquisition and management for knowledge-base development.

  6. Contingency Software in Autonomous Systems

    Science.gov (United States)

    Lutz, Robyn; Patterson-Hine, Ann

    2006-01-01

    This viewgraph presentation reviews the development of contingency software for autonomous systems. Autonomous vehicles currently have a limited capacity to diagnose and mitigate failures. There is a need to be able to handle a broader range of contingencies. The goals of the project are: 1. Speed up diagnosis and mitigation of anomalous situations.2.Automatically handle contingencies, not just failures.3.Enable projects to select a degree of autonomy consistent with their needs and to incrementally introduce more autonomy.4.Augment on-board fault protection with verified contingency scripts

  7. Helicopter engine exhaust rotor downwash effects on laser beams

    Science.gov (United States)

    Henriksson, Markus; Sjöqvist, Lars; Seiffer, Dirk

    2015-10-01

    The hot exhaust gases from engines on helicopters are pushed down by the rotor in a turbulent flow. When the optical path of a laser beam or optical sensor passes through this region severe aberrations of the optical field may result. These perturbations will lead to beam wander and beam distortions that can limit the performance of optical countermeasure systems. To quantify these effects the Italian Air Force Flight Test Centre hosted a trial for the "Airborne platform effects on lasers and warning sensors" (ALWS) EDA-project. Laser beams were propagated from the airport control tower to a target screen in a slant path with the helicopter hovering over this path. Collimated laser beams at 1.55-, 2- and 4.6-μm wavelength were imaged with high speed cameras. Large increases in beam wander and beam divergence were found, with beam wander up to 200 μrad root-mean-square and increases in beam divergence up to 1 mrad. To allow scaling to other laser beam parameters and geometries formulas for propagation in atmospheric turbulence were used even though the turbulence may not follow Kolmogorov statistics. By assuming that the plume is short compared to the total propagation distance the integrated structure parameter through the plume could be calculated. Values in the range 10-10 to 10-8 m1/3 were found when the laser beams passed through the exhaust gases below the helicopter tail. The integrated structure parameter values calculated from beam wander were consistently lower than those calculated from long term spot size, indicating that the method is not perfect but provides information about order of magnitudes. The measured results show that the engine exhaust for worst case beam directions will dominate over atmospheric turbulence even for kilometer path lengths from a helicopter at low altitude. How severe the effect is on system performance will depend on beam and target parameters.

  8. Exploration of Configuration Options for a Large Civil Compound Helicopter

    Science.gov (United States)

    Russell, Carl; Johnson, Wayne

    2013-01-01

    Multiple compound helicopter configurations are designed using a combination of rotorcraft sizing and comprehensive analysis codes. Results from both the conceptual design phase and rotor comprehensive analysis are presented. The designs are evaluated for their suitability to a short-to-medium-haul civil transport mission carrying a payload of 90 passengers. Multiple metrics are used to determine the best configuration, with heavy emphasis placed on minimizing fuel burn.

  9. A study of helicopter rotor dynamics and modeling methods

    OpenAIRE

    Hiatt, Daniel S.

    1995-01-01

    The rotor system is the primary source of vibratory forces on a helicopter. Vibratory forces result from the rotor system response to dynamic and aerodynamic loading. This thesis discusses sources of excitation, and investigates rotor system modeling methods. Computer models based on finite element and Mykiestad methods are developed and compared for the free and forced vibration cases of a nniform rotor blade. The modeling assumptions and the effects of non-iniform physical parameters are di...

  10. GENERATION OF AN ADVANCED HELICOPTER EXPERIMENTAL AERODYNAMIC DATABASE

    OpenAIRE

    Raffel, Markus; de Gegorio, Fabrizio; Sheng, W; GIBERTINI G.; Seraudie, A.; Groot, Klaus de; van der Wall, Berend G.

    2009-01-01

    The GOAHEAD-consortium was created in the frame of an EU-project in order to create an experimental database for the validation of 3D-CFD and comprehensive aeromechanics methods for the prediction of unsteady viscous flows including rotor dynamics for complete helicopter configurations, i.e. main rotor – fuselage – tail rotor configurations with emphasis on viscous phenomena like flow separation and transition from laminar to turbulent flow. The wind tunnel experiments have been p...

  11. Do Army Helicopter Training Simulators Need Motion Bases?

    OpenAIRE

    McCauley, Michael E.

    2006-01-01

    United States Army Research Institute for the Behavioral and Social Sciences This report reviews the arguments and the evidence regarding the need for simulator motion bases in training helicopter pilots. It discusses flight simulators, perceptual fidelity, history of motion bases, disturbance versus maneuver motion, human motion sensation, and reviews the empirical evidence for the training effectiveness of motion bases. The section on training effectiveness reviews research f...

  12. Intelligent Control of Quadrotor Unmanned Helicopter in Hovering Mode

    OpenAIRE

    Neda Shamshiri; Abbas Chatraei

    2015-01-01

    A Quadrotor helicopter is an unmanned aerial vehicle (UAV). This vehicle has attracted lots of researchers’ attention because of its unique abilities such as being an under-actuated system, vertical take-off and landing, spot movement, more degree of freedom (DOF) and military and non- military functions. Because of nonlinear and complex dynamic, modeling and controlling this vehicle is one of the most challenging areas in control engineering. In this paper modeling of a Quadrotor will be des...

  13. Parametrically excited helicopter ground resonance dynamics with high blade asymmetries

    OpenAIRE

    Sanches, Leonardo; Michon, Guilhem; Berlioz, Alain; Alazard, Daniel

    2012-01-01

    The present work is aimed at verifying the influence of high asymmetries in the variation of in-plane lead-lag stiffness of one blade on the ground resonance phenomenon in helicopters. The periodical equations of motions are analyzed by using Floquet's Theory (FM) and the boundaries of instabilities predicted. The stability chart obtained as a function of asymmetry parameters and rotor speed reveals a complex evolution of critical zones and the existence of bifurcation points at low rotor spe...

  14. A review of helicopter rotor blade tip shapes

    Science.gov (United States)

    Brocklehurst, A.; Barakos, G. N.

    2013-01-01

    A review of helicopter rotor blade tip design technology has been carried out with a view to undertaking subsequent computations to evaluate the performance of new tip designs. The review starts by briefly looking at (fixed) wing tip design concepts and the underlying fluid mechanics on which they are based in order to see if there is any carry-over of ideas on which improved tip design concepts might be based. Then, rotor blade tip shapes that have been used, or suggested for use, on past and present rotorcraft are examined to obtain a better understanding of the helicopter tip design problem. In parallel, the review traces the development of analysis tools to evaluate the performance of the rotor and blade tip design. It is clear that in the past, the designer relied heavily on classical aerodynamic knowledge, supplemented by experience and intuition, supported by wind tunnel and model rotor testing, and relatively low-order aerodynamic calculations. New rotor designs were, and still are the subject of intensive flight test verification. However, recent development of Computational Fluid Dynamics (CFD) now offers an opportunity to accurately predict the viscous, compressible flow-field in the tip region, and thus predict the performance of new rotor and tip designs, provided that the solver has adequate resolution, is able to handle all aspects of the helicopter problem, and sufficient computational resources are available to complete the design in a practical time-scale.

  15. Dynamic Analysis of a Helicopter Rotor by Dymore Program

    Science.gov (United States)

    Doğan, Vedat; Kırca, Mesut

    The dynamic behavior of hingeless and bearingless blades of a light commercial helicopter which has been under design process at ITU (İstanbul Technical University, Rotorcraft Research and Development Centre) is investigated. Since the helicopter rotor consists of several parts connected to each other by joints and hinges; rotors in general can be considered as an assembly of the rigid and elastic parts. Dynamics of rotor system in rotation is complicated due to coupling of elastic forces (bending, torsion and tension), inertial forces, control and aerodynamic forces on the rotor blades. In this study, the dynamic behavior of the rotor for a real helicopter design project is analyzed by using DYMORE. Blades are modeled as elastic beams, hub as a rigid body, torque tubes as rigid bodies, control links as rigid bodies plus springs and several joints. Geometric and material cross-sectional properties of blades (Stiffness-Matrix and Mass-Matrix) are calculated by using VABS programs on a CATIA model. Natural frequencies and natural modes of the rotating (and non-rotating) blades are obtained by using DYMORE. Fan-Plots which show the variation of the natural frequencies for different modes (Lead-Lag, Flapping, Feathering, etc.) vs. rotor RPM are presented.

  16. Measurement and Characterization of Helicopter Noise at Different Altitudes

    Science.gov (United States)

    Watts, Michael E.; Greenwood, Eric; Stephenson, James

    2016-01-01

    This paper presents an overview of a flight test campaign performed at different test sites whose altitudes ranged from 0 to 7000 feet above mean sea level (AMSL) between September 2014 and February 2015. The purposes of this campaign were to: investigate the effects of altitude variation on noise generation, investigate the effects of gross weight variation on noise generation, establish the statistical variability in acoustic flight testing of helicopters, and characterize the effects of transient maneuvers on radiated noise for a medium-lift utility helicopter. In addition to describing the test campaign, results of the acoustic effects of altitude variation for the AS350 SD1 and EH-60L aircraft are presented. Large changes in acoustic amplitudes were observed in response to changes in ambient conditions when the helicopter was flown at constant indicated airspeed and gross weight at the three test sites. However, acoustic amplitudes were found to scale with ambient pressure when flight conditions were defined in terms of the non-dimensional parameters, such as the weight coefficient and effective hover tip Mach number.

  17. Advanced automatic target recognition for police helicopter missions

    Science.gov (United States)

    Stahl, Christoph; Schoppmann, Paul

    2000-08-01

    The results of a case study about the application of an advanced method for automatic target recognition to infrared imagery taken from police helicopter missions are presented. The method consists of the following steps: preprocessing, classification, fusion, postprocessing and tracking, and combines the three paradigms image pyramids, neural networks and bayesian nets. The technology has been developed using a variety of different scenes typical for military aircraft missions. Infrared cameras have been in use for several years at the Bavarian police helicopter forces and are highly valuable for night missions. Several object classes like 'persons' or 'vehicles' are tested and the possible discrimination between persons and animals is shown. The analysis of complex scenes with hidden objects and clutter shows the potentials and limitations of automatic target recognition for real-world tasks. Several display concepts illustrate the achievable improvement of the situation awareness. The similarities and differences between various mission types concerning object variability, time constraints, consequences of false alarms, etc. are discussed. Typical police actions like searching for missing persons or runaway criminals illustrate the advantages of automatic target recognition. The results demonstrate the possible operational benefits for the helicopter crew. Future work will include performance evaluation issues and a system integration concept for the target platform.

  18. Development of a helicopter rotor/propulsion system dynamics analysis

    Science.gov (United States)

    Warmbrodt, W.; Hull, R.

    1982-01-01

    A time-domain analysis of coupled engine/drive train/rotor dynamics of a twin-engine, single main rotor helicopter model has been performed. The analysis incorporates an existing helicopter model with nonlinear simulations of a helicopter turboshaft engine and its fuel controller. System dynamic behavior is studied using the resulting simulation which included representations for the two engines and their fuel controllers, drive system, main rotor, tail rotor, and aircraft rigid body motions. Time histories of engine and rotor RPM response to pilot control inputs are studied for a baseline rotor and propulsion system model. Sensitivity of rotor RPM droop to fuel controller gain changes and collective input feed-forward gain changes are studied. Torque-load-sharing between the two engines is investigated by making changes in the fuel controller feedback paths. A linear engine model is derived from the nonlinear engine simulation and used in the coupled system analysis. This four-state linear engine model is then reduced to a three-state model. The effect of this simplification on coupled system behavior is shown.

  19. Selected Problems Of Transmission Wear Of The Mi-24 Helicopter

    Directory of Open Access Journals (Sweden)

    Gębura Andrzej

    2015-12-01

    Full Text Available The hypothesis of mutual, destructive impact of the worn upper bearing of the WR-24 transmission on the Mi-24 helicopter's gearbox was stated. The Mi-24 is the only helicopter operated in Poland, in which the gearbox is mounted outside the main transmission – in the centre of the transmission shaft, between the main gearbox and the tail rotor. Damage to the gears in the gearbox of power generators is equivalent to termination of the tail rotor's drive. Such a termination immediately causes rotation of the body in the direction opposite to the direction of rotation of the main rotor. It is associated with the loss of lift and steering. It may lead to a disaster. Such an incident occurred in January 2011 in Afghanistan – both authors participated in its investigation. The authors, taking into account very good, almost legendary combat properties of the Mi-24, and their research of the specifics of wear and tear of the transmission elements, they think that, first, funds for development and implementation of the drive unit monitoring system should be made available specially for this helicopter. For this purpose, the authors propose to use the FAM-C method. It is characterised with significant ergonomics. Thank to this, multiple kinematic pairs can be observed simultaneously, and, therefore, the relationships between them as well.

  20. Helicopter rotor noise due to ingestion of atmospheric turbulence

    Science.gov (United States)

    Simonich, J. C.; Amiet, R. K.; Schlinker, R. H.; Greitzer, E. M.

    1986-05-01

    A theoretical study was conducted to develop an analytical prediction method for helicopter main rotor noise due to the ingestion of atmospheric turbulence. This study incorporates an atmospheric turbulence model, a rotor mean flow contraction model and a rapid distortion turbulence model which together determine the statistics of the non-isotropic turbulence at the rotor plane. Inputs to the combined mean inflow and turbulence models are controlled by atmospheric wind characteristics and helicopter operating conditions. A generalized acoustic source model was used to predict the far field noise generated by the non-isotropic flow incident on the rotor. Absolute levels for acoustic spectra and directivity patterns were calculated for full scale helicopters, without the use of empirical or adjustable constants. Comparisons between isotropic and non-isotropic turbulence at the rotor face demonstrated pronounced differences in acoustic spectra. Turning and contraction of the flow for hover and low speed vertical ascent cases result in a 3 dB increase in the acoustic spectrum energy and a 10 dB increase in tone levels. Compared to trailing edge noise, turbulence ingestion noise is the dominant noise mechanism below approximately 30 rotor harmonics, while above 100 harmonics, trailing edge noise levels exceed turbulence ingestion noise by 25 dB.

  1. Principal Components Analysis of Triaxial Vibration Data From Helicopter Transmissions

    Science.gov (United States)

    Tumer, Irem Y.; Huff, Edward M.

    2001-01-01

    Research on the nature of the vibration data collected from helicopter transmissions during flight experiments has led to several crucial observations believed to be responsible for the high rates of false alarms and missed detections in aircraft vibration monitoring systems. This work focuses on one such finding, namely, the need to consider additional sources of information about system vibrations. In this light, helicopter transmission vibration data, collected using triaxial accelerometers, were explored in three different directions, analyzed for content, and then combined using Principal Components Analysis (PCA) to analyze changes in directionality. In this paper, the PCA transformation is applied to 176 test conditions/data sets collected from an OH58C helicopter to derive the overall experiment-wide covariance matrix and its principal eigenvectors. The experiment-wide eigenvectors. are then projected onto the individual test conditions to evaluate changes and similarities in their directionality based on the various experimental factors. The paper will present the foundations of the proposed approach, addressing the question of whether experiment-wide eigenvectors accurately model the vibration modes in individual test conditions. The results will further determine the value of using directionality and triaxial accelerometers for vibration monitoring and anomaly detection.

  2. A Robust Compositional Architecture for Autonomous Systems

    Science.gov (United States)

    Brat, Guillaume; Deney, Ewen; Farrell, Kimberley; Giannakopoulos, Dimitra; Jonsson, Ari; Frank, Jeremy; Bobby, Mark; Carpenter, Todd; Estlin, Tara

    2006-01-01

    Space exploration applications can benefit greatly from autonomous systems. Great distances, limited communications and high costs make direct operations impossible while mandating operations reliability and efficiency beyond what traditional commanding can provide. Autonomous systems can improve reliability and enhance spacecraft capability significantly. However, there is reluctance to utilizing autonomous systems. In part this is due to general hesitation about new technologies, but a more tangible concern is that of reliability of predictability of autonomous software. In this paper, we describe ongoing work aimed at increasing robustness and predictability of autonomous software, with the ultimate goal of building trust in such systems. The work combines state-of-the-art technologies and capabilities in autonomous systems with advanced validation and synthesis techniques. The focus of this paper is on the autonomous system architecture that has been defined, and on how it enables the application of validation techniques for resulting autonomous systems.

  3. Development of Lidar Sensor Systems for Autonomous Safe Landing on Planetary Bodies

    Science.gov (United States)

    Amzajerdian, Farzin; Pierottet, Diego F.; Petway, Larry B.; Vanek, Michael D.

    2010-01-01

    Lidar has been identified by NASA as a key technology for enabling autonomous safe landing of future robotic and crewed lunar landing vehicles. NASA LaRC has been developing three laser/lidar sensor systems under the ALHAT project. The capabilities of these Lidar sensor systems were evaluated through a series of static tests using a calibrated target and through dynamic tests aboard helicopters and a fixed wing aircraft. The airborne tests were performed over Moon-like terrain in the California and Nevada deserts. These tests provided the necessary data for the development of signal processing software, and algorithms for hazard detection and navigation. The tests helped identify technology areas needing improvement and will also help guide future technology advancement activities.

  4. Autonomous aerial sensors for wind power meteorology - A pre-project

    Energy Technology Data Exchange (ETDEWEB)

    Giebel, G. (ed.); Schmidt Paulsen, U.; Bange, J.; la Cour-Harbo, A.; Reuder, J.; Mayer, S.; van der Kroonenberg, A.; Moelgaard, J.

    2012-01-15

    Autonomous Aerial Sensors, i.e. meteorological sensors mounted on Unmanned Aerial Systems UAS, can characterise the atmospheric flow in and around wind farms. We instrumented three planes, a helicopter and a lighter-than-air LTA system to fly one week together in a well-instrumented wind farm, partly with nano-synchronised sensors (time stamped with about 100 ns global accuracy). Between bankruptcy of a partner, denied overflight rights at the main test location, denied Civil Aviation Authorities permits at the alternative location, stolen planes, and crashed UAS we managed to collect data at a wind farm in Lolland and on an atmospheric campaign in France. Planning of an offshore campaign using the developed techniques is underway. (Author)

  5. Development of autonomous magnetometer rotorcraft for wide area assessment

    Energy Technology Data Exchange (ETDEWEB)

    Roelof Versteeg; Matt Anderson; Les Beard; Eric Corban; Darryl Curley; Jeff Gamey; Ross Johnson; Dwight Junkin; Mark McKay; Jared Salzmann; Mikhail Tchernychev; Suraj Unnikrishnan; Scott Vinson

    2010-04-01

    Large areas across the United States are potentially contaminated with UXO, with some ranges encompassing tens to hundreds of thousands of acres. Technologies are needed which will allow for cost effective wide area scanning with 1) near 100 % coverage and 2) near 100 % detection of subsurface ordnance or features indicative of subsurface ordnance. The current approach to wide area assessment is a multi-level one, in which medium - altitude fixed wing optical imaging is used for an initial site assessment. This assessment is followed with low altitude manned helicopter based magnetometry. Subsequent to this wide area assessment targeted surface investigations are performed using either towed geophysical sensor arrays or man portable sensors. In order to be an effective tool for small UXO detection, the sensing altitude for magnetic site investigations needs to be on the order of 1 – 3 meters. These altitude requirements mean that manned helicopter surveys will generally only be feasible in large, open and relatively flat terrains. While such surveys are effective in mapping large areas relatively fast there are substantial mobilization/demobilization, staffing and equipment costs associated with these surveys (resulting in costs of approximately $100-$150/acre). In addition, due to the low altitude there are substantial risks to pilots and equipment. Surface towed arrays provide high resolution maps but have other limitations, e.g. in their ability to navigate rough terrain effectively. There is thus a need for other systems which can be used for effective data collection. An UAV (Unmanned Aerial Vehicle) magnetometer platform is an obvious alternative. The motivation behind such a system is that it reduces risk to operators, is lower in initial and Operational and Maintenance (O&M) costs (and can thus potentially be applied to smaller sites) and has the potential of being more effective in terms of detection and possibly characterization (through the use of

  6. Hazard Map for Autonomous Navigation

    DEFF Research Database (Denmark)

    Riis, Troels

    This dissertation describes the work performed in the area of using image analysis in the process of landing a spacecraft autonomously and safely on the surface of the Moon. This is suggested to be done using a Hazard Map. The correspondence problem between several Hazard Maps are investigated...

  7. The Bering Autonomous Target Detection

    DEFF Research Database (Denmark)

    Jørgensen, John Leif; Denver, Troelz; Betto, Maurizio;

    2003-01-01

    telescopes. The method has proven robust in operation and is well suited for use onboard spacecraft. As development target for the method and the associated instrumentation the asteroid research mission Bering has been used. Onboard a spacecraft, the autonomous detection is centered around the fully...

  8. Computing architecture for autonomous microgrids

    Science.gov (United States)

    Goldsmith, Steven Y.

    2015-09-29

    A computing architecture that facilitates autonomously controlling operations of a microgrid is described herein. A microgrid network includes numerous computing devices that execute intelligent agents, each of which is assigned to a particular entity (load, source, storage device, or switch) in the microgrid. The intelligent agents can execute in accordance with predefined protocols to collectively perform computations that facilitate uninterrupted control of the .

  9. Autonomous systems for plant protection

    DEFF Research Database (Denmark)

    Griepentrog, Hans W.; Ruckelshausen, Arno; Jørgensen, Rasmus Nyholm;

    2010-01-01

    autonomous operations related to crop protection probably commercially available in the near future. Scouting and monitoring together with the efficient application of chemicals or mechanical treatments are operations which can be successful automated. Drawbacks are that current systems are lacking robust...

  10. Implementation of a Helicopter Flight Simulator with Individual Blade Control

    Science.gov (United States)

    Zinchiak, Andrew G.

    2011-12-01

    Nearly all modern helicopters are designed with a swashplate-based system for control of the main rotor blades. However, the swashplate-based approach does not provide the level of redundancy necessary to cope with abnormal actuator conditions. For example, if an actuator fails (becomes locked) on the main rotor, the cyclic inputs are consequently fixed and the helicopter may become stuck in a flight maneuver. This can obviously be seen as a catastrophic failure, and would likely lead to a crash. These types of failures can be overcome with the application of individual blade control (IBC). IBC is achieved using the blade pitch control method, which provides complete authority of the aerodynamic characteristics of each rotor blade at any given time by replacing the normally rigid pitch links between the swashplate and the pitch horn of the blade with hydraulic or electronic actuators. Thus, IBC can provide the redundancy necessary for subsystem failure accommodation. In this research effort, a simulation environment is developed to investigate the potential of the IBC main rotor configuration for fault-tolerant control. To examine the applications of IBC to failure scenarios and fault-tolerant controls, a conventional, swashplate-based linear model is first developed for hover and forward flight scenarios based on the UH-60 Black Hawk helicopter. The linear modeling techniques for the swashplate-based helicopter are then adapted and expanded to include IBC. Using these modified techniques, an IBC based mathematical model of the UH-60 helicopter is developed for the purposes of simulation and analysis. The methodology can be used to model and implement a different aircraft if geometric, gravimetric, and general aerodynamic data are available. Without the kinetic restrictions of the swashplate, the IBC model effectively decouples the cyclic control inputs between different blades. Simulations of the IBC model prove that the primary control functions can be manually

  11. Autonomous Duffing-Holmes Type Chaotic Oscillator

    DEFF Research Database (Denmark)

    Tamaševičius, A.; Bumelienė, S.; Kirvaitis, R.; Mykolaitis, G.; Tamaševičiūtė, E.; Lindberg, Erik

    2009-01-01

    We have designed and built a novel Duffing type autonomous 3rd-order chaotic oscillator. In comparison with the common non-autonomous DuffingHolmes type oscillator the autonomous circuit has an internal positive feedback loop instead of an external periodic drive source. In addition, it is...

  12. Indoor Autonomous Airship Control and Navigation System

    OpenAIRE

    Fedorenko Roman; Krukhmalev Victor

    2016-01-01

    The paper presents an automatic control system for autonomous airship. The system is designed to organize autonomous flight of the mini-airship performing flight mission defined from ground control station. Structure, hardware and software implementation of indoor autonomous airship and its navigation and control system as well as experiment results are described.

  13. Indoor Autonomous Airship Control and Navigation System

    Directory of Open Access Journals (Sweden)

    Fedorenko Roman

    2016-01-01

    Full Text Available The paper presents an automatic control system for autonomous airship. The system is designed to organize autonomous flight of the mini-airship performing flight mission defined from ground control station. Structure, hardware and software implementation of indoor autonomous airship and its navigation and control system as well as experiment results are described.

  14. 76 FR 53312 - Airworthiness Directives; Agusta S.p.A. Model A109A and A109AII Helicopters

    Science.gov (United States)

    2011-08-26

    ... Agusta S.p.A. (Agusta) helicopters with a certain tail rotor special hub plug (hub plug) installed. This... to tail rotor failure and subsequent loss of control of the helicopter. DATES: Effective September 12... likely to exist or develop on other helicopters of the same type design. Differences Between This AD...

  15. 75 FR 53857 - Airworthiness Directives; Eurocopter France Model SA330J Helicopters

    Science.gov (United States)

    2010-09-02

    ... likely to exist or develop on other Eurocopter Model SA330J helicopters of the same type design, we... SA330J helicopters, certificated in any category. Compliance: Required as indicated. To prevent rotor... (fan) rotor blade and the upper section of the guide vane bearing housing. This inspection must...

  16. 46 CFR 131.950 - Placard on lifesaving signals and helicopter recovery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Placard on lifesaving signals and helicopter recovery. 131.950 Section 131.950 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Miscellaneous § 131.950 Placard on lifesaving signals and helicopter...

  17. 46 CFR 109.575 - Accumulation of liquids on helicopter decks.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Accumulation of liquids on helicopter decks. 109.575 Section 109.575 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.575 Accumulation of liquids on helicopter decks. The...

  18. Exercise training as treatment of neck pain among military helicopter pilots and crew members

    DEFF Research Database (Denmark)

    Murray, Mike; Lange, Britt; Nørnberg, Bo Riebeling;

    Introduction: Neck pain is frequent among helicopter pilots and crew (1). The aim of this study was to investigate if an exercise intervention could reduce the prevalence of neck-pain among helicopter pilots and crew. Methods: Thirty-one pilots and thirty-eight crew members were randomized to an...

  19. Neck Strength, Position Sense, and Motion in Military Helicopter Crew With and Without Neck Pain

    NARCIS (Netherlands)

    M.H.A.H. van den Oord; V. de Loose; J.K. Sluiter; M.H.W. Frings-Dresen

    2010-01-01

    Introduction: Neck pain in military helicopter pilots and rear aircrew is an occupational health problem that may interfere with flying performance. The aim of the present study was to investigate possible differences in the physical abilities of the cervical spines of helicopter pilots and rear air

  20. 77 FR 38744 - Airworthiness Directives; Sikorsky Aircraft-Manufactured Model S-64F Helicopters

    Science.gov (United States)

    2012-06-29

    ..., which could lead to failure of the MGB and subsequent loss of control of the helicopter. Actions Since... establish life limits for certain components, remove various parts from service, and require consistency in..., failure from static overload, and subsequent loss of control of the helicopter. DATES: We must...

  1. FlyTact : A tactile display improves a helicopter pilot's landing performance in degraded visual environments

    NARCIS (Netherlands)

    Jansen, C.; Wennemers, A.S.; Vos, W.K.; Groen, E.L.

    2008-01-01

    Helicopter landings are more challenging in 'brownout' conditions, in which sand and dust is stirred up by the rotary wing aircraft, obscuring visibility. Safe brownout landings require new sensor and display technologies to provide the pilot with information on helicopter motion. In this respect ta

  2. 36 CFR 222.24 - Use of helicopters, fixed-wing aircraft and motor vehicles.

    Science.gov (United States)

    2010-07-01

    ... stress shall be removed so as to allow recovery. Helicopters may be used in round-ups or other capture... helicopters in capture operations and/or using motor vehicles for the purpose of transporting captured animals, a public meeting will be held in the proximity of the territory where the capture operation...

  3. World’s smallest helicopter to fly in da Vinci birthplace

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The world’s smallest one-man helicopter will soon take flight in the birthplace of Leonardo da Vinci, who is credited with having first thought of a vertical-flight machine, its developer said.The 75-kilogram helicopter will make a demonstration flight in the city of Vinci, near Florence, on May 25, according to

  4. Autonomic computing enabled cooperative networked design

    CERN Document Server

    Wodczak, Michal

    2014-01-01

    This book introduces the concept of autonomic computing driven cooperative networked system design from an architectural perspective. As such it leverages and capitalises on the relevant advancements in both the realms of autonomic computing and networking by welding them closely together. In particular, a multi-faceted Autonomic Cooperative System Architectural Model is defined which incorporates the notion of Autonomic Cooperative Behaviour being orchestrated by the Autonomic Cooperative Networking Protocol of a cross-layer nature. The overall proposed solution not only advocates for the inc

  5. Autonomous Cryogenics Loading Operations Simulation Software: Knowledgebase Autonomous Test Engineer

    Science.gov (United States)

    Wehner, Walter S., Jr.

    2013-01-01

    Working on the ACLO (Autonomous Cryogenics Loading Operations) project I have had the opportunity to add functionality to the physics simulation software known as KATE (Knowledgebase Autonomous Test Engineer), create a new application allowing WYSIWYG (what-you-see-is-what-you-get) creation of KATE schematic files and begin a preliminary design and implementation of a new subsystem that will provide vision services on the IHM (Integrated Health Management) bus. The functionality I added to KATE over the past few months includes a dynamic visual representation of the fluid height in a pipe based on number of gallons of fluid in the pipe and implementing the IHM bus connection within KATE. I also fixed a broken feature in the system called the Browser Display, implemented many bug fixes and made changes to the GUI (Graphical User Interface).

  6. Helicopter Landing Sites, FCC registered helicopter landing pads (hospitals)., Published in 2008, 1:600 (1in=50ft) scale, Waupaca County Land Information.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Helicopter Landing Sites dataset, published at 1:600 (1in=50ft) scale, was produced all or in part from Orthoimagery information as of 2008. It is described as...

  7. Effects of rotor downwash on exhaust plume flow and helicopter infrared signature

    International Nuclear Information System (INIS)

    The effects of rotor downwash and exhaust direction on plume flow field, rear-fuselage temperature distribution and helicopter infrared signature were numerically investigated. The internal flow inside IR suppressor originated from engine exhaust nozzle and the external flow around helicopter airframe originated from rotor downwash were computed in a coupled mode to determine the temperature distributions on the helicopter skin and in the exhaust plume. Based on the skin and plume temperature distributions, a forward–backward ray-tracing method was used to calculate the infrared radiation intensity from the helicopter with a narrow-band model. The results show that the exhaust plume takes on strong downwards deflection to the rear-fuselage, as well as to the rotor rotational direction under the action of rotor downwash. The rotor downwash has a complicated influence on the infrared radiation distribution of helicopter. It is benefit for reducing the infrared radiation intensity when the exhaust is ejected in oblique-turned or lateral-turned mode. While for the up-turned exhaust mode, the exhaust plume could heating the helicopter rear-fuselage and the infrared radiation intensity may be enhanced under the action of downwash. - Highlights: •Illustrate effects of rotor downwash and exhaust direction on plume flow field. •Modeling helicopter infrared signature taking into consideration of rotor downwash action. •Assessing different orientation of exhaust plume on helicopter infrared intensity. •Oblique-turned exhaust mode is reasonable for helicopter infrared suppressor. •Rotor downwash has a complicated influence on helicopter infrared radiation distribution

  8. Development of autonomous operation system

    International Nuclear Information System (INIS)

    To enhance operation reliability of nuclear plants by removing human factors, study on an autonomous operation system has been carried out to substitute artificial intelligence (AI) for plant operators and, in addition, traditional controllers used in existing plants. For construction of the AI system, structurization of knowledge on the basis of the principles such as physical laws, function and structure of relevant objects and generalization of problem solving process are intended. A hierarchical distributed cooperative system configuration in employed because it is superior from the viewpoint of dynamical reorganization of system functions. This configuration is realized by an object-oriented multi-agent system. Construction of a prototype system was planned and the conceptual design was made for FBR plant in order to evaluate applicability of AI to the autonomous operation and to have a prospect for the realization of the system. The prototype system executes diagnosis, state evaluation, operation and control for the main plant subsystems. (author)

  9. An Autonomously Reciprocating Transmembrane Nanoactuator.

    Science.gov (United States)

    Watson, Matthew A; Cockroft, Scott L

    2016-01-22

    Biological molecular machines operate far from equilibrium by coupling chemical potential to repeated cycles of dissipative nanomechanical motion. This principle has been exploited in supramolecular systems that exhibit true machine behavior in solution and on surfaces. However, designed membrane-spanning assemblies developed to date have been limited to simple switches or stochastic shuttles, and true machine behavior has remained elusive. Herein, we present a transmembrane nanoactuator that turns over chemical fuel to drive autonomous reciprocating (back-and-forth) nanomechanical motion. Ratcheted reciprocating motion of a DNA/PEG copolymer threaded through a single α-hemolysin pore was induced by a combination of DNA strand displacement processes and enzyme-catalyzed reactions. Ion-current recordings revealed saw-tooth patterns, indicating that the assemblies operated in autonomous, asymmetric cycles of conformational change at rates of up to one cycle per minute. PMID:26661295

  10. Cardiovascular autonomic neuropathy in diabetes

    DEFF Research Database (Denmark)

    Spallone, Vincenza; Ziegler, Dan; Freeman, Roy;

    2011-01-01

    Cardiovascular Autonomic Neuropathy (CAN) Subcommittee of Toronto Consensus Panel on Diabetic Neuropathy worked to update CAN guidelines, with regard to epidemiology, clinical impact, diagnosis, usefulness of CAN testing, and management. CAN is the impairment of cardiovascular autonomic control...... in the setting of diabetes after exclusion of other causes. The prevalence of confirmed CAN is around 20%, and increases up to 65% with age and diabetes duration. Established risk factors for CAN are glycaemic control in type 1 and a combination of hypertension, dyslipidemia, obesity and glycaemic control...... in type 2 diabetes. CAN is a risk marker of mortality and cardiovascular morbidity, and possibly a progression promoter of diabetic nephropathy. Criteria for CAN diagnosis and staging are: 1. one abnormal cardio-vagal test identifies possible or early CAN; 2. at least two abnormal cardio-vagal tests...

  11. Treatment of gastrointestinal autonomic neuropathy.

    Science.gov (United States)

    Törnblom, Hans

    2016-03-01

    The symptoms caused by gastrointestinal autonomic neuropathy in diabetes mellitus is important to highlight since it affects a large proportion of people with diabetes, regardless of whether this is type 1 or type 2. Gastroparesis and general signs of bowel dysfunction, such as constipation, diarrhoea and abdominal pain are most often encountered and involve both pharmacological and non-pharmacological treatment options. This mini-review summarises a presentation given at the 'Diagnosis and treatment of autonomic diabetic neuropathy in the gut' symposium at the 2015 annual meeting of the EASD. It is accompanied by another mini-review on a topic from this symposium (by Azpiroz and Malagelada, DOI: 10.1007/s00125-015-3831-1 ) and a commentary by the Session Chair, Péter Kempler (DOI: 10.1007/s00125-015-3826-y ). PMID:26634570

  12. Advancing Autonomous Structural Health Monitoring

    OpenAIRE

    Grisso, Benjamin Luke

    2007-01-01

    The focus of this dissertation is aimed at advancing autonomous structural health monitoring. All the research is based on developing the impedance method for monitoring structural health. The impedance technique utilizes piezoelectric patches to interrogate structures of interested with high frequency excitations. These patches are bonded directly to the structure, so information about the health of the structure can be seen in the electrical impedance of the piezoelectric patch. However, tr...

  13. Insurance for autonomous underwater vehicles

    OpenAIRE

    Griffiths, G; N Bose; Ferguson, J.; Blidberg, D.R.

    2007-01-01

    The background and practice of insurance for autonomous underwater vehicles (AUVs) are examined. Key topics include: relationships between clients, brokers and underwriters; contract wording to provide appropriate coverage; and actions to take when an incident occurs. Factors that affect cost of insurance are discussed, including level of autonomy, team experience and operating environment. Four case studies from industry and academia illustrate how AUV insurance has worked in practice. The p...

  14. Autonomous gliding entry guidance with

    OpenAIRE

    Guo Jie; Wu Xuzhong; Tang Shengjing

    2015-01-01

    This paper presents a novel three-dimensional autonomous entry guidance for relatively high lift-to-drag ratio vehicles satisfying geographic constraints and other path constraints. The guidance is composed of onboard trajectory planning and robust trajectory tracking. For trajectory planning, a longitudinal sub-planner is introduced to generate a feasible drag-versus-energy profile by using the interpolation between upper boundary and lower boundary of entry corridor to get the desired traje...

  15. Robotic perception for autonomous navigation

    OpenAIRE

    Furlan,

    2014-01-01

    This thesis presents the research work the author carried on during his PhD on the topic of robotic perception for autonomous navigation. In particular, the efforts focus on the Self-Localization, Scene Understanding and Object Detection and Tracking problems, proposing for each of these three topics one or more approaches that present an improvement over the state-of-the-art. In some cases the proposed approaches mutually exploit the generated information to improve the quality of the final ...

  16. Prototype design for autonomous vehicle

    OpenAIRE

    Lehander, Jacob; Persson, Joel

    2015-01-01

    This thesis describes the mechanical design of a prototype vehicle developed for a company located in California. The project was based on an earlier vehicle located at KTH, Transport Labs, and investigated if the existing concept for the vehicle would work as a concept for an autonomous prototype, with focus on component layout and increased forces. The design of the vehicle is based on a concept with a carbon fiber bottom plate, two separate suspension modules with electric hub motors and s...

  17. Design of Autonomous Underwater Vehicle

    OpenAIRE

    Tadahiro Hyakudome

    2011-01-01

    There are concerns about the impact that global warming will have on our environment, and which will inevitably result in expanding deserts and rising water levels. While a lot of underwater vehicles are utilized, AUVs (Autonomous Underwater Vehicle) were considered and chosen, as the most suitable tool for conduction survey concerning these global environmental problems. AUVs can comprehensive survey because the vehicle does not have to be connected to the support vessel by tether cable. Whe...

  18. Autonomous Behavior of Computational Agents

    Czech Academy of Sciences Publication Activity Database

    Vaculín, Roman; Neruda, Roman

    Wien : Springer-Verlag, 2005 - (Ribiero, B.; Albrecht, R.; Dobnikar, A.; Pearson, D.; Steele, N.), s. 514-517 ISBN 3-211-24934-6. [ICANNGA'2005 /7./. Coimbra (PT), 21.03.2005-23.03.2005] R&D Projects: GA AV ČR 1ET100300419 Institutional research plan: CEZ:AV0Z10300504 Keywords : computational agents * autonomous behavior * reasoning Subject RIV: BA - General Mathematics

  19. Nonlinear State Estimation and Modeling of a Helicopter UAV

    Science.gov (United States)

    Barczyk, Martin

    Experimentally-validated nonlinear flight control of a helicopter UAV has two necessary conditions: an estimate of the vehicle’s states from noisy multirate output measurements, and a nonlinear dynamics model with minimum complexity, physically controllable inputs and experimentally identified parameter values. This thesis addresses both these objectives for the Applied Nonlinear Controls Lab (ANCL)'s helicopter UAV project. A magnetometer-plus-GPS aided Inertial Navigation System (INS) for outdoor flight as well as an Attitude and Heading Reference System (AHRS) for indoor testing are designed, implemented and experimentally validated employing an Extended Kalman Filter (EKF), using a novel calibration technique for the magnetometer aiding sensor added to remove the limitations of an earlier GPS-only aiding design. Next the recently-developed nonlinear observer design methodology of invariant observers is adapted to the aided INS and AHRS examples, employing a rotation matrix representation for the state manifold to obtain designs amenable to global stability analysis, obtaining a direct nonlinear design for gains of the AHRS observer, modifying the previously-proposed Invariant EKF systematic method for computing gains, and culminating in simulation and experimental validation of the observers. Lastly a nonlinear control-oriented model of the helicopter UAV is derived from first principles, using a rigid-body dynamics formulation augmented with models of the on-board subsystems: main rotor forces and blade flapping dynamics, the Bell-Hiller system and flybar flapping dynamics, tail rotor forces, tail gyro unit, engine and rotor speed, servo operation, fuselage drag, and tail stabilizer forces. The parameter values in the resulting models are identified experimentally. Using these the model is further simplified to be tractable for model-based control design.

  20. Neural control of helicopter blade-vortex interaction noise

    Science.gov (United States)

    Glaessel, Holger; Kloeppel, Valentin; Rudolph, Stephan

    2001-06-01

    Significant reduction of helicopter blade-vortex interaction (BVI) noise is currently one of the most advanced research topics in the helicopter industry. This is due to the complex flow, the close aerodynamic and structural coupling, and the interaction of the blades with the trailing edge vortices. Analytical and numerical modeling techniques are therefore currently still far from a sufficient degree of accuracy to obtain satisfactory results using classical model based control concepts. Neural networks with a proven potential to learn nonlinear relationships implicitly encoded in a training data set are therefore an appropriate and complementary technique for the alternative design of a nonlinear controller for BVI noise reduction. For nonlinear and adaptive control different neural control strategies have been proposed. Two possible approaches, a direct and an indirect neural controller are described. In indirect neural control, the plant has to be identified first by training a network with measured data. The plant network is then used to train the controller network. On the other hand the direct control approach does not rely on an explicit plant model, instead a specific training algorithm (like reinforcement learning) uses the information gathered from interactions with the environment. In the investigation of the BVI noise phenomena, helicopter developers have undertaken substantial efforts in full scale flight tests and wind tunnel experiments. Data obtained in these experiments have been adequately preprocessed using wavelet analysis and filtering techniques and are then used in the design of a neural controller. Neural open-loop control and neural closed-loop control concepts for the BVI noise reduction problem are conceived, simulated and compared against each other in this work in the above mentioned framework.

  1. System and Method for Finite Element Simulation of Helicopter Turbulence

    Science.gov (United States)

    McFarland, R. E. (Inventor); Dulsenberg, Ken (Inventor)

    1999-01-01

    The present invention provides a turbulence model that has been developed for blade-element helicopter simulation. This model uses an innovative temporal and geometrical distribution algorithm that preserves the statistical characteristics of the turbulence spectra over the rotor disc, while providing velocity components in real time to each of five blade-element stations along each of four blades. for a total of twenty blade-element stations. The simulator system includes a software implementation of flight dynamics that adheres to the guidelines for turbulence set forth in military specifications. One of the features of the present simulator system is that it applies simulated turbulence to the rotor blades of the helicopter, rather than to its center of gravity. The simulator system accurately models the rotor penetration into a gust field. It includes time correlation between the front and rear of the main rotor, as well as between the side forces felt at the center of gravity and at the tail rotor. It also includes features for added realism, such as patchy turbulence and vertical gusts in to which the rotor disc penetrates. These features are realized by a unique real time implementation of the turbulence filters. The new simulator system uses two arrays one on either side of the main rotor to record the turbulence field and to produce time-correlation from the front to the rear of the rotor disc. The use of Gaussian Interpolation between the two arrays maintains the statistical properties of the turbulence across the rotor disc. The present simulator system and method may be used in future and existing real-time helicopter simulations with minimal increase in computational workload.

  2. Autonomic neuropathy in diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Alberto eVerrotti

    2014-12-01

    Full Text Available Diabetic autonomic neuropathy (DAN is a serious and common complication of diabetes, often overlooked and misdiagnosed. It is a systemic-wide disorder that may be asymptomatic in the early stages. The most studied and clinically important form of DAN is cardiovascular autonomic neuropathy (CAN defined as the impairment of autonomic control of the cardiovascular system in patients with diabetes after exclusion of other causes. The reported prevalence of DAN varies widely depending on inconsistent definition, different diagnostic method, different patient cohorts studied. The pathogenesis is still unclear and probably multifactorial. Once DAN becomes clinically evident, no form of therapy has been identified which can effectively stop or reverse it. Prevention strategies are based on strict glycemic control with intensive insulin treatment, multifactorial intervention and lifestyle modification including control of hypertension, dyslipidemia, stop smoking, weight loss and adequate physical exercise. The present review summarizes the latest knowledge regarding clinical presentation, epidemiology, pathogenesis and management of DAN, with some mention to childhood and adolescent population.

  3. Semi autonomous mine detection system

    Energy Technology Data Exchange (ETDEWEB)

    Douglas Few; Roelof Versteeg; Herman Herman

    2010-04-01

    CMMAD is a risk reduction effort for the AMDS program. As part of CMMAD, multiple instances of semi autonomous robotic mine detection systems were created. Each instance consists of a robotic vehicle equipped with sensors required for navigation and marking, a countermine sensors and a number of integrated software packages which provide for real time processing of the countermine sensor data as well as integrated control of the robotic vehicle, the sensor actuator and the sensor. These systems were used to investigate critical interest functions (CIF) related to countermine robotic systems. To address the autonomy CIF, the INL developed RIK was extended to allow for interaction with a mine sensor processing code (MSPC). In limited field testing this system performed well in detecting, marking and avoiding both AT and AP mines. Based on the results of the CMMAD investigation we conclude that autonomous robotic mine detection is feasible. In addition, CMMAD contributed critical technical advances with regard to sensing, data processing and sensor manipulation, which will advance the performance of future fieldable systems. As a result, no substantial technical barriers exist which preclude – from an autonomous robotic perspective – the rapid development and deployment of fieldable systems.

  4. Aerodynamic Interaction Effects of a Helicopter Rotor and Fuselage

    Science.gov (United States)

    Boyd, David D., Jr.

    1999-01-01

    A three year Cooperative Research Agreements made in each of the three years between the Subsonic Aerodynamics Branch of the NASA Langley Research Center and the Virginia Polytechnic Institute and State University (Va. Tech) has been completed. This document presents results from this three year endeavor. The goal of creating an efficient method to compute unsteady interactional effects between a helicopter rotor and fuselage has been accomplished. This paper also includes appendices to support these findings. The topics are: 1) Rotor-Fuselage Interactions Aerodynamics: An Unsteady Rotor Model; and 2) Rotor/Fuselage Unsteady Interactional Aerodynamics: A New Computational Model.

  5. Validation of Comprehensive Helicopter Aeroelastic Analysis with Experimental Data

    Directory of Open Access Journals (Sweden)

    Shrinivas R. Bhat

    2004-10-01

    Full Text Available The experimental data for a Cbladed soft-inplane hingeless main rotor is used to validate a comprehensive aeroelastic analysis. A finite element model has been developed for the rotorblade which predicts rotating frequencies quite well, across a range of rotation speeds. The helicopter is trimmed and the predicted trim-control angles are found to be In the range ofmeasured values for a variety of flight speeds. Power predictions over a range of forward speeds also compare well. Finally, the aeroelastlc analysis is used to study the Importance ofaerodynamic models on the vibration predict~onU. nsteady aerodynamics and free-wake models have been investigated.

  6. Multilevel Analysis of Continuous AE from Helicopter Gearbox

    Czech Academy of Sciences Publication Activity Database

    Chlada, Milan; Převorovský, Zdeněk; Heřmánek, Jan; Krofta, Josef

    2014-01-01

    Roč. 19, č. 12 (2014). ISSN 1435-4934. [European Conference on Non-Destructive Testing (ECNDT 2014) /11./. Praha, 06.10.2014-10.10.2014] R&D Projects: GA MPO FR-TI3/755 Institutional support : RVO:61388998 Keywords : structural health monitoring (SHM) * signal processing * acoustic emission (AE) * diagnostics of helicopter gearbox * wavelet analysis * continuous acoustic emission Subject RIV: JU - Aeronautics, Aerodynamics, Aircrafts http://www.ndt.net/events/ECNDT2014/app/ content /Paper/630_Chlada_Rev1.pdf

  7. A procedure for establishing an approximate helicopter performance model

    OpenAIRE

    Sethson, Magnus

    2011-01-01

    The main performance characteristics of a heli- copter is its fuel consumption. This paper re- ports the current state in an ongoing project seeking a fast and approximative implementa- tion of mathematical models for helicopter per- formance predictions, primarily in terms of fuel consumption. The model is limited to a subset of the normal operation modes, only including hover, climb and forward. Also, the focus is on smaller rotors, i.e. sub-scale rotors in the range of 1.5m to 4.0m in diam...

  8. Panoramic dynamic data acquisition system based on unmanned helicopter

    Science.gov (United States)

    Yao, Yigang; Zhao, Shuguang; Lin, Zhaorong; Wen, Gaojin; Zhang, Qian; Zhang, Weiwei

    2012-10-01

    In recent years, the archaeological tourism has rapidly been developed all over the world, and it has become more and more popular. However, the scope of the human activities has been restricted by complicated geographical terrain, and the popularization of archaeological tourism has been hampered. For the purpose of solving the above problem, the archaeological tourism system of the panoramic dynamic data acquisition system based on unmanned helicopter is designed, and we got the image of the Chinese Ming Dynasty Great Wall realtime 360˚ panoramic dynamic monitor. The applying of this system will increase the scope of the archaeological tourism activities.

  9. The simple analytics of Helicopter money: Why it works - always

    OpenAIRE

    Willem H. Buiter

    2014-01-01

    This paper aims to provide a rigorous analysis of Milton Friedman’s famous parable of the ‘helicopter’ drop of money. A helicopter drop of money is a permanent/irreversible increase in the nominal stock of fiat base money with a zero nominal interest rate, which respects the intertemporal budget constraint of the consolidated Central Bank and fiscal authority/Treasury – the State. An example would be a temporary fiscal stimulus (say a one-off transfer payment to households, as in Friedman’s e...

  10. Trimmed CFD Simulation of a Complete Helicopter Configuration

    OpenAIRE

    Khier, Walid; Dietz, Markus; Schwarz, Thorsten; Wagner, Siegfried

    2007-01-01

    An investigation was carried out using the flight mechanics tool HOST weakly coupled to the RANS solver FLOWer to simulate the flow around helicopter configuration under different flight conditions. The configuration considered was a wind tunnel model with powered 4.2 meter four-bladed main rotor, and 0.73 meter two bladed tail rotor. Two forward flight conditions at Mach number equal to 0.059 and 0.204 were considered at 5o and -2o angle of attack, respectively. The objective was to asses th...

  11. Autonomous Cryogenic Load Operations: KSC Autonomous Test Engineer

    Science.gov (United States)

    Shrading, Nicholas J.

    2012-01-01

    The KSC Autonomous Test Engineer (KATE) program has a long history at KSC. Now a part of the Autonomous Cryogenic Load Operations (ACLO) mission, this software system has been sporadically developed over the past 20+ years. Originally designed to provide health and status monitoring for a simple water-based fluid system, it was proven to be a capable autonomous test engineer for determining sources of failure in. the system, As part.of a new goal to provide this same anomaly-detection capability for a complicated cryogenic fluid system, software engineers, physicists, interns and KATE experts are working to upgrade the software capabilities and graphical user interface. Much progress was made during this effort to improve KATE. A display ofthe entire cryogenic system's graph, with nodes for components and edges for their connections, was added to the KATE software. A searching functionality was added to the new graph display, so that users could easily center their screen on specific components. The GUI was also modified so that it displayed information relevant to the new project goals. In addition, work began on adding new pneumatic and electronic subsystems into the KATE knowledgebase, so that it could provide health and status monitoring for those systems. Finally, many fixes for bugs, memory leaks, and memory errors were implemented and the system was moved into a state in which it could be presented to stakeholders. Overall, the KATE system was improved and necessary additional features were added so that a presentation of the program and its functionality in the next few months would be a success.

  12. Autonomous Cryogenic Load Operations: Knowledge-Based Autonomous Test Engineer

    Science.gov (United States)

    Schrading, J. Nicolas

    2013-01-01

    The Knowledge-Based Autonomous Test Engineer (KATE) program has a long history at KSC. Now a part of the Autonomous Cryogenic Load Operations (ACLO) mission, this software system has been sporadically developed over the past 20 years. Originally designed to provide health and status monitoring for a simple water-based fluid system, it was proven to be a capable autonomous test engineer for determining sources of failure in the system. As part of a new goal to provide this same anomaly-detection capability for a complicated cryogenic fluid system, software engineers, physicists, interns and KATE experts are working to upgrade the software capabilities and graphical user interface. Much progress was made during this effort to improve KATE. A display of the entire cryogenic system's graph, with nodes for components and edges for their connections, was added to the KATE software. A searching functionality was added to the new graph display, so that users could easily center their screen on specific components. The GUI was also modified so that it displayed information relevant to the new project goals. In addition, work began on adding new pneumatic and electronic subsystems into the KATE knowledge base, so that it could provide health and status monitoring for those systems. Finally, many fixes for bugs, memory leaks, and memory errors were implemented and the system was moved into a state in which it could be presented to stakeholders. Overall, the KATE system was improved and necessary additional features were added so that a presentation of the program and its functionality in the next few months would be a success.

  13. Reliability model for helicopter main gearbox lubrication system using influence diagrams

    International Nuclear Information System (INIS)

    The loss of oil from a helicopter main gearbox (MGB) leads to increased friction between components, a rise in component surface temperatures, and subsequent mechanical failure of gearbox components. A number of significant helicopter accidents have been caused due to such loss of lubrication. This paper presents a model to assess the reliability of helicopter MGB lubricating systems. Safety risk modeling was conducted for MGB oil system related accidents in order to analyse key failure mechanisms and the contributory factors. Thus, the dominant failure modes for lubrication systems and key contributing components were identified. The Influence Diagram (ID) approach was then employed to investigate reliability issues of the MGB lubrication systems at the level of primary causal factors, thus systematically investigating a complex context of events, conditions, and influences that are direct triggers of the helicopter MGB lubrication system failures. The interrelationships between MGB lubrication system failure types were thus identified, and the influence of each of these factors on the overall MGB lubrication system reliability was assessed. This paper highlights parts of the HELMGOP project, sponsored by the European Aviation Safety Agency to improve helicopter main gearbox reliability. - Highlights: • We investigated methods to optimize helicopter MGB oil system run-dry capability. • Used Influence Diagram to assess design and maintenance factors of MGB oil system. • Factors influencing overall MGB lubrication system reliability were identified. • This globally influences current and future helicopter MGB designs

  14. Correlation of airloads on a two-bladed helicopter rotor

    Science.gov (United States)

    Fernandez, Francisco J.; Johnson, Wayne

    1993-01-01

    Airloads measured on a two-bladed helicopter rotor in flight during the Ames' Tip Aerodynamic and Acoustic Test are compared with calculations from a comprehensive helicopter analysis (CAMRAD/JA), and the pressures compared with calculations from a full-potential rotor code (FPR). The flight-test results cover an advance ratio range of 0.19 to 0.38. The lowest-speed case is characterized by the presence of significant blade-vortex interactions. Good correlation of peak-to-peak vortex-induced loads and the corresponding pressures is obtained. Results of the correlation for this two-bladed rotor are substantially similar to those for three- and four-bladed rotors, including the tip-vortex core size for best correlation, calculation of the peak-to-peak loads on the retreating side, and calculation of vortex iduced loads on inboard radial stations. The higher-speed cases are characterized by the presence of transonic flow on the outboard sections of the blade. Comparison of calculated and measured airloads on the advancing side is not considered appropriate because the presence of shocks makes chordwise integration of the measured data difficult. However, good correlation of the corresponding pressures is obtained.

  15. Differential Degradation Assessment of Helicopter Engines Operated in Marine Environment

    Directory of Open Access Journals (Sweden)

    Mathews P. Samuel

    2014-07-01

    Full Text Available The helicopters used for marine operations encounter harsh environment laden with salt mist, sand and dust which could accelerate the deterioration of components. Assessment of the effect of operational environment on component degradation of such helicopter engines is crucial in scheduling their maintenance and ensuring flight safety. The objective of this study is to understand and assess the differential degradation pattern of aeroengines operated in marine environment in comparison to their counterparts operated in non-marine environment. In this study, a sample of 257 ex-service aeroengines of same type and make, operated in marine and non-marine environment were randomly selected and their degradation pattern observed. After obtaining the data on component degradation, further statistical analysis was carried out and the statistical significance of the observations were computed. Out of the ten major components considered in this study, five of them were found to have statistically significant differential degradation due to operation in marine environment. For the remaining components adequate evidence was not available to substantiate differential degradation due to operation in marine environment. These findings serve as valuable input for maintenance inventory planning as well as component improvement programme.Defence Science Journal, Vol. 64, No. 4, July 2014, pp. 371-377, DOI:http://dx.doi.org/10.14429/dsj.64.4007 

  16. Numerical Simulation of Helicopter Cockpit Seat subjected to Crash Impact

    Directory of Open Access Journals (Sweden)

    M.N. Sulaiman

    2013-01-01

    Full Text Available Sikorsky S-61 or better known as “Nuri” had served the Malaysian aviation sector for the past four decades. It is mainly used for transportation, combat search and rescue purposes. However, there were Nuri helicopter crashes or accident cases reported during its operation period which involved loss of its occupants. The pilot survivability rate can be improved provided that the vertical impact loading on the helicopter is reduced during the crash accident. Utilization of an energy absorbing pilot seat or cockpit structure maybe one of the approaches to minimize the impact shock exerted to the occupants. However, the shock or maximum acceleration of the cockpit/pilot seat has to be first determined before a thorough design scheme can be undertaken. In this study, a vertical crash event of the Nuri pilot seat from 500 feet altitude was simulated and the maximum acceleration rate was determined using MSC PATRAN/LSDYNA. The pilot survivability was determined by comparing the result with human tolerance criteria data available in other published works. From the result, it was found that the maximum acceleration of the Nuri pilot seat was 584.4g at 19. 63 milliseconds, thus it can be concluded that the survivability aspect of the pilot is fatal when compared to other published works.

  17. Generic Helicopter-Based Testbed for Surface Terrain Imaging Sensors

    Science.gov (United States)

    Alexander, James; Goldberg, Hannah; Montgomery, James; Spiers, Gary; Liebe, Carl; Johnson, Andrew; Gromov, Konstantin; Konefat, Edward; Lam, Raymond; Meras, Patrick

    2008-01-01

    To be certain that a candidate sensor system will perform as expected during missions, we have developed a field test system and have executed test flights with a helicopter-mounted sensor platform over desert terrains, which simulate Lunar features. A key advantage to this approach is that different sensors can be tested and characterized in an environment relevant to the flight needs prior to flight. Testing the various sensors required the development of a field test system, including an instrument to validate the truth of the sensor system under test. The field test system was designed to be flexible enough to cover the test needs of many sensors (lidar, radar, cameras) that require an aerial test platform, including helicopters, airplanes, unmanned aerial vehicles (UAV), or balloons. To validate the performance of the sensor under test, the dynamics of the test platform must be known with sufficient accuracy to provide accurate models for input into algorithm development. The test system provides support equipment to measure the dynamics of the field test sensor platform, and allow computation of the truth position, velocity, attitude, and time.

  18. Sensor supported pilot assistance for helicopter flight in DVE

    Science.gov (United States)

    Waanders, Tim; Münsterer, T.; Kress, M.

    2013-05-01

    Helicopter operations at low altitude are to this day only performed under VFR conditions in which safe piloting of the aircraft relies on the pilot's visual perception of the outside environment. However, there are situations in which a deterioration of visibility conditions may cause the pilot to lose important visual cues thereby increasing workload and compromising flight safety and mission effectiveness. This paper reports on a pilot assistance system for all phases of flight which is intended to: • Provide navigational support and mission management • Support landings/take-offs in unknown environment and in DVE • Enhance situational awareness in DVE • Provide obstacle and terrain surface detection and warning • Provide upload, sensor based update and download of database information for debriefing and later missions. The system comprises a digital terrain and obstacle database, tactical information, flight plan management combined with an active 3D sensor enabling the above mentioned functionalities. To support pilots during operations in DVE, an intuitive 3D/2D cueing through both head-up and head-down means is proposed to retain situational awareness. This paper further describes the system concept and will elaborate on results of simulator trials in which the functionality was evaluated by operational pilots in realistic and demanding scenarios such as a SAR mission to be performed in mountainous area under different visual conditions. The objective of the simulator trials was to evaluate the functional integration and HMI definition for the NH90 Tactical Transport Helicopter.

  19. Autonomic Management for Multi-agent Systems

    OpenAIRE

    Nadir kamal Salih; G. K. Viju; Mohamed, Abdelmotalib A.

    2011-01-01

    Autonomic computing is a computing system that can manage itself by self-configuration, self-healing, self-optimizing and self-protection. Researchers have been emphasizing the strong role that multi agent systems can play progressively towards the design and implementation of complex autonomic systems. The important of autonomic computing is to create computing systems capable of managing themselves to a far greater extent than they do today. With the nature of autonomy, reactivity, socialit...

  20. Gastrointestinal autonomic nerve tumor of the stomach

    OpenAIRE

    Meshikhes, Abdul-Wahed N.; Al-Garni, Ayed A.; Sami A Al-Momen; Al-Nahawi, Mamdouh; Abu Subaih, Jawad

    2014-01-01

    Patient: Female, 32 Final Diagnosis: Gastrintestinal Autonomic Nerve Tumor (GANT) Symptoms: anemia • anorexia • fatigue • fever • hearburn • nausea • weight loss Medication: — Clinical Procedure: — Specialty: Gastroenterology and Hepatology Objective: Rare disease Background: Gastrointestinal autonomic nerve tumors (GANT) are extremely rare tumors that are related to gastrointestinal autonomic nervous plexuses. They are distinguished from stromal tumors by their unique ultrastructural feature...

  1. Test and Evaluation of Autonomous Ground Vehicles

    OpenAIRE

    Yang Sun; Guangming Xiong; Weilong Song; Jianwei Gong; Huiyan Chen

    2014-01-01

    A preestablished test and evaluation system will benefit the development of autonomous ground vehicles. This paper proposes a design method for a scientific and comprehensive test and evaluation system for autonomous ground vehicles competitions. It can better guide and regulate the development of China’s autonomous ground vehicles. The test and evaluation system includes the test contents, the test environment, the test methods, and the evaluation methods. Using a hierarchical design approac...

  2. Obstacle Detection and Avoidance Autonomous Car

    OpenAIRE

    K.Vasavi; M.V.S.Praveen

    2014-01-01

    Driving models are needed by many researchers to improve traffic safety and to advance autonomous vehicle design. To be most useful, a driving model must state specifically what information is needed and how it is processed. So we developed an “Obstacle Avoidance and Detection Autonomous Car” based on sensor application. The essential part of this autonomous car is that it drives taking the energy from solar panel. This paper explains the method of interfacing the solar panel, relay circuit b...

  3. Tele/Autonomous Robot For Nuclear Facilities

    Science.gov (United States)

    Backes, Paul G.; Tso, Kam S.

    1994-01-01

    Fail-safe tele/autonomous robotic system makes it unnecessary for human technicians to enter nuclear-fuel-reprocessing facilities and other high-radiation or otherwise hazardous industrial environments. Used to carry out experiments as exchanging equipment modules, turning bolts, cleaning surfaces, and grappling turning objects by use of mixture of autonomous actions and teleoperation with either single arm or two cooperating arms. System capable of fully autonomous operation, teleoperation or shared control.

  4. Self-Adapting Reactive Autonomous Agents

    Science.gov (United States)

    Andrecut, M.; Ali, M. K.

    This paper describes a new self-adapting control algorithm for reactive autonomous agents. The architecture of the autonomous agents integrates the reactive behavior with reinforcement learning. We show how these components perform on-line adaptation of the autonomous agents to various complex navigation situations by constructing an internal model of the environment. Also, a discussion on cooperation and coordination of teams of agents is presented.

  5. Autonomous vehicle control systems for safe crossroads

    OpenAIRE

    Alonso Ruiz, Javier; Milanés Montero, Vicente; Pérez, Joshué; Onieva Caracuel, Enrique; González Fernández-Vallejo, Carlos; Pedro Lucio, María Teresa de

    2011-01-01

    This article presents a cooperative manoeuvre among three dual mode cars – vehicles equipped with sensors and actuators, and that can be driven either manually or autonomously. One vehicle is driven autonomously and the other two are driven manually. The main objective is to test two decision algorithms for priority conflict resolution at intersections so that a vehicle autonomously driven can take their own decision about crossing an intersection mingling with manually driven cars without th...

  6. The applicability of a helicopter patrol procedure to diverse areas: A cost-benefit evaluation

    OpenAIRE

    Kirchner, Robert E.; Schnelle, John F.; Domash, Michele; Larson, Lynn; Carr, Adam; McNees, M. Patrick

    1980-01-01

    The residential burglary deterrent effects of a helicopter patrol procedure were investigated in four separate areas with a multiple baseline technology. The helicopter was flown during an 8:00 a.m. to 4:00 p.m. period in two high density population areas of approximately 9.82 and 14.71 square miles and two low density population areas of 117.49 and 89.97 square miles. The helicopter patrol reduced residential burglaries without crime displacement in the two high density areas but had no dete...

  7. Sensitivity analysis of helicopter IMC decelerating steep approach and landing performance to navigation system parameters

    Science.gov (United States)

    Karmali, M. S.; Phatak, A. V.

    1982-01-01

    Results of a study to investigate, by means of a computer simulation, the performance sensitivity of helicopter IMC DSAL operations as a function of navigation system parameters are presented. A mathematical model representing generically a navigation system is formulated. The scenario simulated consists of a straight in helicopter approach to landing along a 6 deg glideslope. The deceleration magnitude chosen is 03g. The navigation model parameters are varied and the statistics of the total system errors (TSE) computed. These statistics are used to determine the critical navigation system parameters that affect the performance of the closed-loop navigation, guidance and control system of a UH-1H helicopter.

  8. Information for Successful Interaction with Autonomous Systems

    Science.gov (United States)

    Malin, Jane T.; Johnson, Kathy A.

    2003-01-01

    Interaction in heterogeneous mission operations teams is not well matched to classical models of coordination with autonomous systems. We describe methods of loose coordination and information management in mission operations. We describe an information agent and information management tool suite for managing information from many sources, including autonomous agents. We present an integrated model of levels of complexity of agent and human behavior, which shows types of information processing and points of potential error in agent activities. We discuss the types of information needed for diagnosing problems and planning interactions with an autonomous system. We discuss types of coordination for which designs are needed for autonomous system functions.

  9. Autonomic dysfunction in primary sleep disorders.

    Science.gov (United States)

    Miglis, Mitchell G

    2016-03-01

    The autonomic nervous system plays an important role in the coordination of many important physiologic functions during sleep. Many patients with untreated sleep disorders will describe symptoms of autonomic impairment, and a majority of patients with autonomic impairment have some form of sleep disorder. This article will explore possible explanations for this connection, as well as review the current literature on autonomic impairment in common primary sleep disorders including obstructive sleep apnea, insomnia, restless legs syndrome, periodic limb movement disorder, narcolepsy, and rapid eye movement sleep behavior disorder. PMID:27198946

  10. Design of a Miniature Autonomous Surveillance Robot

    Institute of Scientific and Technical Information of China (English)

    ZHENG Chang-e; HUANG Qiang; HUANG Yuan-can

    2009-01-01

    The small size of miniature robots poses great challenges for the mechanical and deetrieal design and the implementation of autonomous capabilities.In this paper,the mechanical and electrical design for a twowheeled cylindrical miniature autonomous robot ("BMS-1",BIT MicroScout-1) is presented and some autonomous capabilities are implemented by multiple sensors and some arithmetic models.Several experimental results show that BMS-1 is useful for surveillance in confined spaces and suitable for large-scale surveillance due to some autonomous capabilities.

  11. A necessary and sufficient condition for transforming autonomous systems into linear autonomous Birkhoffian systems

    International Nuclear Information System (INIS)

    The problem of transforming autonomous systems into Birkhoffian systems is studied. A reasonable form of linear autonomous Birkhoff equations is given. By combining them with the undetermined tensor method, a necessary and sufficient condition for an autonomous system to have a representation in terms of linear autonomous Birkhoff equations is obtained. The methods of constructing Birkhoffian dynamical functions are given. Two examples are given to illustrate the application of the results. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  12. Autonomic Function in Neurodegenerative Diseases

    DEFF Research Database (Denmark)

    Sørensen, Gertrud Laura; Jennum, Poul Jørgen

    2013-01-01

    and REM sleep control, indicating that the disorder may serve as a human model for the sleep-wake and REM sleep flip-flop switches. The increased frequency of transitions may cause increased sympathetic activity during sleep and thereby increased heart rate, or the increased heart rate could be caused...... confirm that hypocretin deficiency affects the autonomic nervous system of patients with narcolepsy and that the hypocretin system is important for proper heart rate modulation at rest.Furthermore, it was shown that hypocretin deficiency and cataplexy are associated with signs of destabilized sleep-wake...

  13. Autonomous sensor manager agents (ASMA)

    Science.gov (United States)

    Osadciw, Lisa A.

    2004-04-01

    Autonomous sensor manager agents are presented as an algorithm to perform sensor management within a multisensor fusion network. The design of the hybrid ant system/particle swarm agents is described in detail with some insight into their performance. Although the algorithm is designed for the general sensor management problem, a simulation example involving 2 radar systems is presented. Algorithmic parameters are determined by the size of the region covered by the sensor network, the number of sensors, and the number of parameters to be selected. With straight forward modifications, this algorithm can be adapted for most sensor management problems.

  14. Konstruktion av en autonom vindstation

    OpenAIRE

    Larsson, Joel; Starck, Patrik

    2015-01-01

    Construction of an autonomous wind station was a project with the goal of creating a product that could collect wind data from a sensor and then transfer this data to a server wirelessly over the GSM network. The device would be powered by batteries and solar cells and function fully without requiring external power supply. This required that a small computer was constructed and programmed to store and send data at predetermined cycle times and programming of a server that received the sent d...

  15. BART: The Czech Autonomous Observatory

    Czech Academy of Sciences Publication Activity Database

    Nekola, Martin; Hudec, René; Jelínek, M.; Kubánek, P.; Štrobl, Jan; Polášek, Cyril

    2010-01-01

    Roč. 2010, Spec. Is. (2010), 103986/1-103986/5. ISSN 1687-7969. [Workshop on Robotic Autonomous Observatories. Málaga, 18.05.2009-21.05.2009] R&D Projects: GA ČR GA205/08/1207 Grant ostatní: ESA(XE) ESA-PECS project No. 98023; Spanish Ministry of Education and Science(ES) AP2003-1407 Institutional research plan: CEZ:AV0Z10030501 Keywords : robotic telescope * BART * gamma ray bursts Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics http://www.hindawi.com/journals/aa/2010/103986.html

  16. Knowledge acquisition for autonomous systems

    Science.gov (United States)

    Lum, Henry; Heer, Ewald

    1988-01-01

    Knowledge-based capabilities for autonomous aerospace systems, such as the NASA Space Station, must encompass conflict-resolution functions comparable to those of human operators, with all elements of the system working toward system goals in a concurrent, asynchronous-but-coordinated fashion. Knowledge extracted from a design database will support robotic systems by furnishing geometric, structural, and causal descriptions required for repair, disassembly, and assembly. The factual knowledge for these databases will be obtained from a master database through a technical management information system, and it will in many cases have to be augmented by domain-specific heuristic knowledge acquired from domain experts.

  17. Topological entropy of autonomous flows

    Energy Technology Data Exchange (ETDEWEB)

    Badii, R. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    When studying fluid dynamics, especially in a turbulent regime, it is crucial to estimate the number of active degrees of freedom or of localized structures in the system. The topological entropy quantifies the exponential growth of the number of `distinct` orbits in a dynamical system as a function of their length, in the infinite spatial resolution limit. Here, I illustrate a novel method for its evaluation, which extends beyond maps and is applicable to any system, including autonomous flows: these are characterized by lack of a definite absolute time scale for the orbit lengths. (author) 8 refs.

  18. The Autonomous Pathogen Detection System

    Energy Technology Data Exchange (ETDEWEB)

    Dzenitis, J M; Makarewicz, A J

    2009-01-13

    We developed, tested, and now operate a civilian biological defense capability that continuously monitors the air for biological threat agents. The Autonomous Pathogen Detection System (APDS) collects, prepares, reads, analyzes, and reports results of multiplexed immunoassays and multiplexed PCR assays using Luminex{copyright} xMAP technology and flow cytometer. The mission we conduct is particularly demanding: continuous monitoring, multiple threat agents, high sensitivity, challenging environments, and ultimately extremely low false positive rates. Here, we introduce the mission requirements and metrics, show the system engineering and analysis framework, and describe the progress to date including early development and current status.

  19. Autonomous Real Time Requirements Tracing

    Science.gov (United States)

    Plattsmier, George; Stetson, Howard

    2014-01-01

    One of the more challenging aspects of software development is the ability to verify and validate the functional software requirements dictated by the Software Requirements Specification (SRS) and the Software Detail Design (SDD). Insuring the software has achieved the intended requirements is the responsibility of the Software Quality team and the Software Test team. The utilization of Timeliner-TLX(sup TM) Auto- Procedures for relocating ground operations positions to ISS automated on-board operations has begun the transition that would be required for manned deep space missions with minimal crew requirements. This transition also moves the auto-procedures from the procedure realm into the flight software arena and as such the operational requirements and testing will be more structured and rigorous. The autoprocedures would be required to meet NASA software standards as specified in the Software Safety Standard (NASASTD- 8719), the Software Engineering Requirements (NPR 7150), the Software Assurance Standard (NASA-STD-8739) and also the Human Rating Requirements (NPR-8705). The Autonomous Fluid Transfer System (AFTS) test-bed utilizes the Timeliner-TLX(sup TM) Language for development of autonomous command and control software. The Timeliner-TLX(sup TM) system has the unique feature of providing the current line of the statement in execution during real-time execution of the software. The feature of execution line number internal reporting unlocks the capability of monitoring the execution autonomously by use of a companion Timeliner-TLX(sup TM) sequence as the line number reporting is embedded inside the Timeliner-TLX(sup TM) execution engine. This negates I/O processing of this type data as the line number status of executing sequences is built-in as a function reference. This paper will outline the design and capabilities of the AFTS Autonomous Requirements Tracker, which traces and logs SRS requirements as they are being met during real-time execution of the

  20. Fuzzy control of autonomous robot

    International Nuclear Information System (INIS)

    An autonomous robot which can move and find its own route to a destination by means of fuzzy control is under development. An AI technique is utilized to determine the route to a destination from geographical information gathered through an ITV camera mounted on the robot. Information on robot location is also gained through an ITV camera, and, by applying fuzzy inference operation, the robot's movement is controlled. This paper describes the methods that are used for finding a route and controlling movement. Effectiveness of the proposed methods has been confirmed through actual robot movement tests and through computer simulations. (author)

  1. Autonomous Dome for Robotic Telescope

    CERN Document Server

    Kumar, Akash; Ganesh, Shashikiran

    2016-01-01

    Physical Research Laboratory operates a 50cm robotic observatory at Mount Abu. This Automated Telescope for Variability Studies (ATVS) makes use of Remote Telescope System 2 (RTS2) for autonomous operations. The observatory uses a 3.5m dome from Sirius Observatories. We have developed electronics using Arduino electronic circuit boards with home grown logic and software to control the dome operations. We are in the process of completing the drivers to link our Arduino based dome controller with RTS2. This document is a short description of the various phases of the development and their integration to achieve the required objective.

  2. Plant Watering Autonomous Mobile Robot

    Directory of Open Access Journals (Sweden)

    Hema Nagaraja

    2012-07-01

    Full Text Available Now days, due to busy routine life, people forget to water their plants. In this paper, we present a completely autonomous and a cost-effective system for watering indoor potted plants placed on an even surface. The system comprises of a mobile robot and a temperature-humidity sensing module. The system is fully adaptive to any environment and takes into account the watering needs of the plants using the temperature-humidity sensing module. The paper describes the hardware architecture of the fully automated watering system, which uses wireless communication to communicate between the mobile robot and the sensing module. This gardening robot is completely portable and is equipped with a Radio Frequency Identification (RFID module, a microcontroller, an on-board water reservoir and an attached water pump. It is capable of sensing the watering needs of the plants, locating them and finally watering them autonomously without any human intervention. Mobilization of the robot to the potted plant is achieved by using a predefined path. For identification, an RFID tag is attached to each potted plant. The paper also discusses the detailed implementation of the system supported with complete circuitry. Finally, the paper concludes with system performance including the analysis of the water carrying capacity and time requirements to water a set of plants.

  3. Multi-agent autonomous system

    Science.gov (United States)

    Fink, Wolfgang (Inventor); Dohm, James (Inventor); Tarbell, Mark A. (Inventor)

    2010-01-01

    A multi-agent autonomous system for exploration of hazardous or inaccessible locations. The multi-agent autonomous system includes simple surface-based agents or craft controlled by an airborne tracking and command system. The airborne tracking and command system includes an instrument suite used to image an operational area and any craft deployed within the operational area. The image data is used to identify the craft, targets for exploration, and obstacles in the operational area. The tracking and command system determines paths for the surface-based craft using the identified targets and obstacles and commands the craft using simple movement commands to move through the operational area to the targets while avoiding the obstacles. Each craft includes its own instrument suite to collect information about the operational area that is transmitted back to the tracking and command system. The tracking and command system may be further coupled to a satellite system to provide additional image information about the operational area and provide operational and location commands to the tracking and command system.

  4. Autonomous Robotic Inspection in Tunnels

    Science.gov (United States)

    Protopapadakis, E.; Stentoumis, C.; Doulamis, N.; Doulamis, A.; Loupos, K.; Makantasis, K.; Kopsiaftis, G.; Amditis, A.

    2016-06-01

    In this paper, an automatic robotic inspector for tunnel assessment is presented. The proposed platform is able to autonomously navigate within the civil infrastructures, grab stereo images and process/analyse them, in order to identify defect types. At first, there is the crack detection via deep learning approaches. Then, a detailed 3D model of the cracked area is created, utilizing photogrammetric methods. Finally, a laser profiling of the tunnel's lining, for a narrow region close to detected crack is performed; allowing for the deduction of potential deformations. The robotic platform consists of an autonomous mobile vehicle; a crane arm, guided by the computer vision-based crack detector, carrying ultrasound sensors, the stereo cameras and the laser scanner. Visual inspection is based on convolutional neural networks, which support the creation of high-level discriminative features for complex non-linear pattern classification. Then, real-time 3D information is accurately calculated and the crack position and orientation is passed to the robotic platform. The entire system has been evaluated in railway and road tunnels, i.e. in Egnatia Highway and London underground infrastructure.

  5. Structured control for autonomous robots

    International Nuclear Information System (INIS)

    To operate in rich, dynamic environments, autonomous robots must be able to effectively utilize and coordinate their limited physical and occupational resources. As complexity increases, it becomes necessary to impose explicit constraints on the control of planning, perception, and action to ensure that unwanted interactions between behaviors do not occur. This paper advocates developing complex robot systems by layering reactive behaviors onto deliberative components. In this structured control approach, the deliberative components handle normal situations and the reactive behaviors, which are explicitly constrained as to when and how they are activated, handle exceptional situations. The Task Control Architecture (TCA) has been developed to support this approach. TCA provides an integrated set of control constructs useful for implementing deliberative and reactive behaviors. The control constructs facilitate modular and evolutionary system development: they are used to integrate and coordinate planning, perception, and execution, and to incrementally improve the efficiency and robustness of the robot systems. To date, TCA has been used in implementing a half-dozen mobile robot systems, including an autonomous six-legged rover and indoor mobile manipulator

  6. Helicopter Flight Test of a Compact, Real-Time 3-D Flash Lidar for Imaging Hazardous Terrain During Planetary Landing

    Science.gov (United States)

    Roback, VIncent E.; Amzajerdian, Farzin; Brewster, Paul F.; Barnes, Bruce W.; Kempton, Kevin S.; Reisse, Robert A.; Bulyshev, Alexander E.

    2013-01-01

    A second generation, compact, real-time, air-cooled 3-D imaging Flash Lidar sensor system, developed from a number of cutting-edge components from industry and NASA, is lab characterized and helicopter flight tested under the Autonomous Precision Landing and Hazard Detection and Avoidance Technology (ALHAT) project. The ALHAT project is seeking to develop a guidance, navigation, and control (GN&C) and sensing system based on lidar technology capable of enabling safe, precise crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The Flash Lidar incorporates a 3-D imaging video camera based on Indium-Gallium-Arsenide Avalanche Photo Diode and novel micro-electronic technology for a 128 x 128 pixel array operating at a video rate of 20 Hz, a high pulse-energy 1.06 µm Neodymium-doped: Yttrium Aluminum Garnet (Nd:YAG) laser, a remote laser safety termination system, high performance transmitter and receiver optics with one and five degrees field-of-view (FOV), enhanced onboard thermal control, as well as a compact and self-contained suite of support electronics housed in a single box and built around a PC-104 architecture to enable autonomous operations. The Flash Lidar was developed and then characterized at two NASA-Langley Research Center (LaRC) outdoor laser test range facilities both statically and dynamically, integrated with other ALHAT GN&C subsystems from partner organizations, and installed onto a Bell UH-1H Iroquois "Huey" helicopter at LaRC. The integrated system was flight tested at the NASA-Kennedy Space Center (KSC) on simulated lunar approach to a custom hazard field consisting of rocks, craters, hazardous slopes, and safe-sites near the Shuttle Landing Facility runway starting at slant ranges of 750 m. In order to evaluate different methods of achieving hazard detection, the lidar, in conjunction with the ALHAT hazard detection and GN&C system, operates in both a narrow 1deg FOV raster

  7. Maximizing commonality between military and general aviation fly-by-light helicopter system designs

    Science.gov (United States)

    Enns, Russell; Mossman, David C.

    1995-05-01

    In the face of shrinking defense budgets, survival of the United States rotorcraft industry is becoming increasingly dependent on increased sales in a highly competitive civil helicopter market. As a result, only the most competitive rotorcraft manufacturers are likely to survive. A key ingredient in improving our competitive position is the ability to produce more versatile, high performance, high quality, and low cost of ownership helicopters. Fiber optic technology offers a path of achieving these objectives. Also, adopting common components and architectures for different helicopter models (while maintaining each models' uniqueness) will further decrease design and production costs. Funds saved (or generated) by exploiting this commonality can be applied to R&D used to further improve the product. In this paper, we define a fiber optics based avionics architecture which provides the pilot a fly-by-light / digital flight control system which can be implemented in both civilian and military helicopters. We then discuss the advantages of such an architecture.

  8. Direct CFD Predictions of Low Frequency Sounds Generated by Helicopter Main Rotors

    Science.gov (United States)

    Sim, Ben W.; Potsdam, Mark; Conner, Dave; Watts, Michael E.

    2010-01-01

    This proposed paper will highlight the application of a CSD/CFD methodology currently inuse by the US Army Aerfolightdynamics Directorate (AFDD) to assess the feasibility and fidelity of directly predicting low frequency sounds of helicopter rotors.

  9. A Hybrid Flight Control for a Simulated Raptor-30 V2 Helicopter

    Directory of Open Access Journals (Sweden)

    Arbab Nighat Khizer

    2015-04-01

    Full Text Available This paper presents a hybrid flight control system for a single rotor simulated Raptor-30 V2 helicopter. Hybrid intelligent control system, combination of the conventional and intelligent control methodologies, is applied to small model helicopter. The proposed hybrid control used PID as a traditional control and fuzzy as an intelligent control so as to take the maximum advantage of advanced control theory. The helicopter?s model used; comes from X-Plane flight simulator and their hybrid flight control system was simulated using MATLAB/SIMULINK in a simulation platform. X-Plane is also used to visualize the performance of this proposed autopilot design. Through a series of numerous experiments, the operation of hybrid control system was investigated. Results verified that the proposed hybrid control has an excellent performance at hovering flight mode.

  10. 14 CFR Appendix B to Part 29 - Airworthiness Criteria for Helicopter Instrument Flight

    Science.gov (United States)

    2010-01-01

    ... lateral control motion or force. Longitudinal cyclic movement with sideslip must not be excessive. VI..., and the steepest IFR precision approach gradient for which the helicopter is approved; (b)...

  11. Accuracies of Positioning and Geodata Using Helicopters for Geodetic and Geophysical Surveys

    Science.gov (United States)

    Bielenberg, O.; Meyer, U.; Vasterling, M.

    2010-12-01

    : Helicopters are frequently used for airborne surveys in geodesy and geophysics. The range of accuracies needed for proper data reconstruction is wide spread from some meters for airborne magnetics to centimeters for laser scanner measurements. This study lists up to date methods of online and offline positioning, discusses their accuracies that may be achieved and relates them to different geodetic as geophysical surveys in different types of terrain. The goal is to match helicopter positioning methods with the given survey task to optimize results and work efficiency. Some fundamental studies have been conducted on helicopter work during the DESIRE (Dead Sea Integrated Research) project in Israel and Jordan which have been continued in Germany. These studies include the impact of vibrations on INS, IMU and gravity meter systems as well as the choice of antenna locations on the shell of the helicopter.

  12. Time domain system identification of longitudinal dynamics of single rotor model helicopter using sidpac

    International Nuclear Information System (INIS)

    This paper presents a time-domain approach for identification of longitudinal dynamics of single rotor model helicopter. A frequency sweep excitation input signal is applied for hover flying mode widely used for space state linearized model. A fully automated programmed flight test method provides high quality flight data for system identification using the computer controlled flight simulator X-plane. The flight test data were recorded, analyzed and reduced using the SIDPAC (System Identification Programs for Air Craft) toolbox for MATLAB, resulting in an aerodynamic model of single rotor helicopter. Finally, the identified model of single rotor helicopter is validated on Raptor 30-class model helicopter at hover showing the reliability of proposed approach. (author)

  13. Ultra-heavy vertical lift system: The Heli-Stat. [helicopter - airship combination for materials handling

    Science.gov (United States)

    Piasecki, F. N.

    1975-01-01

    A hybrid VTOL airship which is combined with helicopters is evaluated. The static lift of the airship supports approximately the full empty weight of the entire assembly. The helicopter rotors furnish the lift to support the payload as well as the propulsion and control about all axes. Thus existing helicopters, with no new technology required, can be made to lift payloads of ten times the capacity of each one alone, and considerably more than that of any airship built so far. A vehicle is described which has a 75-ton payload, based on four existing CH-53D helicopters and an airship of 3,600,000 cu. ft. The method of interconnection is described along with discussion of control, instrumentation, drive system and critical design conditions. The vertical lift and positioning capabilities of this vehicle far exceed any other means available today, yet can be built with a minimum of risk, development cost and time.

  14. Time domain System Identification of Longitudinal Dynamics of Single Rotor Model Helicopter using SIDPAC

    Directory of Open Access Journals (Sweden)

    Arbab Nighat Khizer

    2015-01-01

    Full Text Available This paper presents a time-domain approach for identification of longitudinal dynamics of single rotor model helicopter. A frequency sweep excitation input signal is applied for hover flying mode widely used for space state linearized model. A fully automated programmed flight test method provides high quality flight data for system identification using the computer controlled flight simulator X-plane©. The flight test data were recorded, analyzed and reduced using the SIDPAC (System Identification Programs for Air Craft toolbox for MATLAB, resulting in an aerodynamic model of single rotor helicopter. Finally, the identified model of single rotor helicopter is validated on Raptor 30-class model helicopter at hover showing the reliability of proposed approach

  15. [An ambulance helicopter in Jamtland. A survival necessity in a county of tourism].

    Science.gov (United States)

    Ek, B; Zetterström, H

    2000-03-22

    The county of Jämtland is a sparsely populated area in which an ambulance-helicopter has been in use since the middle of the 1970's. A prospective study was undertaken during a six month period with the aim of evaluating the benefits of the helicopter as compared with the use of road-ambulance transport alone. Total number of patients involved was n = 249. Both flight nurses and receiving doctors found that in most cases, patients transported by helicopter manned with a flight nurse were given higher quality care. A follow-up study by specialists from the receiving departments confirmed that for 3% (n = 8), transport by ambulance-helicopter resulted in "probably better prognosis", and that for 2% (n = 6) the result was "lifesaving". PMID:10765625

  16. Autonomous Control of Space Reactor Systems

    Energy Technology Data Exchange (ETDEWEB)

    Belle R. Upadhyaya; K. Zhao; S.R.P. Perillo; Xiaojia Xu; M.G. Na

    2007-11-30

    Autonomous and semi-autonomous control is a key element of space reactor design in order to meet the mission requirements of safety, reliability, survivability, and life expectancy. Interrestrial nuclear power plants, human operators are avilable to perform intelligent control functions that are necessary for both normal and abnormal operational conditions.

  17. Intelligent autonomous systems 12. Vol. 2. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sukhan [Sungkyunkwan Univ., Gyeonggi-Do (Korea, Republic of). College of Information and Communication Engineering; Yoon, Kwang-Joon [Konkuk Univ., Seoul (Korea, Republic of); Cho, Hyungsuck [Daegu Gyeongbuk Institute of Science and Technology, Daegu (Korea, Republic of); Lee, Jangmyung (eds.) [Pusan National Univ. (Korea, Republic of). Dept. of Electronics Engineering

    2013-02-01

    Recent research in Intelligent and Autonomous Systems. Volume 2 of the proceedings of the 12th International Conference IAS-12, held June 26-29, 2012, jeju Island, Korea. Written by leading experts in the field. Intelligent autonomous systems are emerged as a key enabler for the creation of a new paradigm of services to humankind, as seen by the recent advancement of autonomous cars licensed for driving in our streets, of unmanned aerial and underwater vehicles carrying out hazardous tasks on-site, and of space robots engaged in scientific as well as operational missions, to list only a few. This book aims at serving the researchers and practitioners in related fields with a timely dissemination of the recent progress on intelligent autonomous systems, based on a collection of papers presented at the 12th International Conference on Intelligent Autonomous Systems, held in Jeju, Korea, June 26-29, 2012. With the theme of ''Intelligence and Autonomy for the Service to Humankind, the conference has covered such diverse areas as autonomous ground, aerial, and underwater vehicles, intelligent transportation systems, personal/domestic service robots, professional service robots for surgery/rehabilitation, rescue/security and space applications, and intelligent autonomous systems for manufacturing and healthcare. This volume 2 includes contributions devoted to Service Robotics and Human-Robot Interaction and Autonomous Multi-Agent Systems and Life Engineering.

  18. Autonomic Nervous System and Immune System Interactions

    OpenAIRE

    Kenney, MJ; Ganta, CK

    2014-01-01

    The present review assesses the current state of literature defining integrative autonomic-immune physiological processing, focusing on studies that have employed electrophysiological, pharmacological, molecular biological and central nervous system experimental approaches. Central autonomic neural networks are informed of peripheral immune status via numerous communicating pathways, including neural and non-neural. Cytokines and other immune factors affect the level of activity and responsiv...

  19. Autonomous Control of Space Reactor Systems

    International Nuclear Information System (INIS)

    Autonomous and semi-autonomous control is a key element of space reactor design in order to meet the mission requirements of safety, reliability, survivability, and life expectancy. Interrestrial nuclear power plants, human operators are available to perform intelligent control functions that are necessary for both normal and abnormal operational conditions

  20. A Practical Approach to Autonomic Dysfunction in Patients with Headache.

    Science.gov (United States)

    Ailani, Jessica

    2016-05-01

    The presence of autonomic symptoms can make the diagnosis of headache challenging. While commonly seen with the trigeminal autonomic cephalalgias, autonomic dysfunction can also be present in patients with migraine, or with a variety of secondary headaches. The pathophysiology of cranial autonomic symptoms in headache is based between the trigeminal system and the hypothalamus. This article will review the pathophysiology and presence of autonomic dysfunction in headache and will provide techniques to help in headache diagnosis in patients with autonomic dysfunction. PMID:27021770

  1. The Effects of Ambient Conditions on Helicopter Rotor Source Noise Modeling

    Science.gov (United States)

    Schmitz, Frederic H.; Greenwood, Eric

    2011-01-01

    A new physics-based method called Fundamental Rotorcraft Acoustic Modeling from Experiments (FRAME) is used to demonstrate the change in rotor harmonic noise of a helicopter operating at different ambient conditions. FRAME is based upon a non-dimensional representation of the governing acoustic and performance equations of a single rotor helicopter. Measured external noise is used together with parameter identification techniques to develop a model of helicopter external noise that is a hybrid between theory and experiment. The FRAME method is used to evaluate the main rotor harmonic noise of a Bell 206B3 helicopter operating at different altitudes. The variation with altitude of Blade-Vortex Interaction (BVI) noise, known to be a strong function of the helicopter s advance ratio, is dependent upon which definition of airspeed is flown by the pilot. If normal flight procedures are followed and indicated airspeed (IAS) is held constant, the true airspeed (TAS) of the helicopter increases with altitude. This causes an increase in advance ratio and a decrease in the speed of sound which results in large changes to BVI noise levels. Results also show that thickness noise on this helicopter becomes more intense at high altitudes where advancing tip Mach number increases because the speed of sound is decreasing and advance ratio increasing for the same indicated airspeed. These results suggest that existing measurement-based empirically derived helicopter rotor noise source models may give incorrect noise estimates when they are used at conditions where data were not measured and may need to be corrected for mission land-use planning purposes.

  2. Failure analysis of a bearing in a helicopter turbine engine due to electrical discharge damage

    OpenAIRE

    Michael K. Budinski

    2014-01-01

    This article documents the metallurgical evaluation of a rolling element bearing that failed due to electrical discharge damage. This rolling element bearing was used in a helicopter turbine engine that failed in-flight, resulting in a hard landing of the helicopter. Optical and electron microscopy as well as energy dispersive spectroscopy were used to evaluate the bearing. Pitting and material transfer on the external bearing races bearing and mating surfaces revealed that the electrical dis...

  3. Helicopter passenger survival suit standards in the UK offshore oil industry.

    Science.gov (United States)

    Leese, W L; Norman, J N

    1979-02-01

    Special protective clothing for helicopter passengers in transit to and from installations in the U.K. offshore oil industry is considered essential. Such clothing is required to increase the survival chances in the unlikely event of a helicopter ditching. This paper discusses the nature of the threat to life in such an event and proposes standards for the specific protective clothing required to meet it. Test criteria are also outlined, to ensure that standards set are maintained. PMID:444170

  4. Low Cost Helicopter Training Simulator : A Software Case Study from the Brazilian Military Police

    OpenAIRE

    Mendes, Joice B.; Brandao-Ramos, Alexandre Carlos; Mora-Camino, Félix

    2014-01-01

    International audience This work describes a computer based training system to assist the crew members to learn the ground school of helicopter AS350-B2, manufactured by HELIBRAS, a Brazilian helicopter company and widely used by the Armed Forces, Civil and Military Policies and by companies of executive transportation and load lifting. The training system consists of a 1:1 scale aircraft cabin simulator, a system software and a MS Flight Simulator interface. The project is in advanced pha...

  5. AirDyn: an instrumented model-scale helicopter for measuring unsteady aerodynamic loading in airwakes

    Science.gov (United States)

    Wang, Y.; Curran, J.; Padfield, G. D.; Owen, I.

    2011-04-01

    This paper describes the design, calibration and application of an instrument that measures the effects of unsteady air flow (airwake) on a helicopter in flight. The instrument is a 1/54th-scale model helicopter that is mounted on a six-component dynamic force balance to measure the forces and moments that an airwake imposes onto the helicopter; it is therefore an 'Airwake Dynamometer' to which we have given the name AirDyn. The AirDyn has been designed, in particular, to measure the effect of a ship airwake on a helicopter translating over the ship's landing deck. The AirDyn, which has been implemented in a water tunnel, in preference to a wind tunnel, senses the integrated effect of a turbulent airwake on the helicopter, and the resulting unsteady forces and moments are an indication of the workload the pilot would need to exert to counteract these effects in a real helicopter. Binocular sensing elements and semiconductor strain gauges have been adopted to achieve high sensitivity and relatively high stiffness. The compact strain gauge balance is fitted into the helicopter fuselage, and protective coatings and a flexible bellows are used to seal the balance and protect it from the water. The coefficient matrix of the AirDyn has been obtained by static calibrations, while impulse excitation tests have confirmed that its frequency response is suitable for the measurements of unsteady loads. The application of the instrument is illustrated by using it to quantify the effect that a bulky ship mast has on the airwake and thus on a helicopter as it lands onto a simplified ship in a scaled 50 knot headwind.

  6. Takagi-Sugeno Fuzzy Model Identification for Small Scale Unmanned Helicopter

    OpenAIRE

    Arbab Nighat; Dai Yaping; Syed Amjad Ali; Xu Xiang Yang

    2013-01-01

    This paper presents system identification method for small unmanned helicopter based on Takagi Sugeno fuzzy models under hover. Firstly,the nonlinear discrete model of small unmanned helicopter with unknown parametersis determined by Takagi Sugeno system. Secondly, derivative based gradientmethod is used to identify unknown parameters of TS fuzzy model because in gradientadaptation, fuzzy system is not supposed to be linear in the parameters, so allfuzzy sets for input and output could be adj...

  7. System identification and optimal control of a small-scale unmanned helicopter / Marthinus Christoffel Terblanche

    OpenAIRE

    Terblanche, Marthinus Christoffel

    2014-01-01

    The use of rotary winged unmanned aerial vehicles in military and civilian applications is rapidly increasing. The primary objective of this study is to develop an automatic flight control system for a radio controlled (RC) helicopter. There is a need for a simple, easy to use methodology to develop automatic flight controllers for first-flight. In order to make the work accessible to new research groups without physical helicopter platforms, a simulation environment is created fo...

  8. Autonomic Management for Multi-agent Systems

    Directory of Open Access Journals (Sweden)

    Nadir kamal Salih

    2011-09-01

    Full Text Available Autonomic computing is a computing system that can manage itself by self-configuration, self-healing, self-optimizing and self-protection. Researchers have been emphasizing the strong role that multi agent systems can play progressively towards the design and implementation of complex autonomic systems. The important of autonomic computing is to create computing systems capable of managing themselves to a far greater extent than they do today. With the nature of autonomy, reactivity, sociality and pro-activity, software agents are promising to make autonomic computing system a reality. This paper mixed multi-agent system with autonomic feature that completely hides its complexity from users/services. Mentioned Java Application Development Framework (JADE as platform example of this environment, could applied to web services as front end to users. With multi agent support it also provides adaptability, intelligence, collaboration, goal oriented interactions, flexibility, mobility and persistence in software systems.

  9. Autonomic Management for Multi-agent Systems

    CERN Document Server

    Salih, Nadir K; Viju, PG K; Mohamed, Abdelmotalib A

    2011-01-01

    Autonomic computing is a computing system that can manage itself by self-configuration, self-healing, self-optimizing and self-protection. Researchers have been emphasizing the strong role that multi agent systems can play progressively towards the design and implementation of complex autonomic systems. The important of autonomic computing is to create computing systems capable of managing themselves to a far greater extent than they do today. With the nature of autonomy, reactivity, sociality and pro-activity, software agents are promising to make autonomic computing system a reality. This paper mixed multi-agent system with autonomic feature that completely hides its complexity from users/services. Mentioned Java Application Development Framework as platform example of this environment, could applied to web services as front end to users. With multi agent support it also provides adaptability, intelligence, collaboration, goal oriented interactions, flexibility, mobility and persistence in software systems

  10. Cardiovascular autonomic neuropathy in the diabetic patients.

    Directory of Open Access Journals (Sweden)

    Maria Eugenia Niño Mantilla

    2007-11-01

    Full Text Available the dysfunction of the autonomic nervous system is a serious problem in diabetic patients. The cardiovacular autonomic neuropathy is the most important autonomic dysfuntion for it´s implication in the increasesof the mortality rate in diabetis patients. tis ethiopatogenesis is the result of a multifactorial process caused by chronic hyperglycemia, ending up in damage of the autonomic fibers thet innervate the heart and blood vessels, leading to dysfuntional hearth rate control and abnormal vascular dynamics. the associated clinical manifestations include orthotatic hypotension, excecise intolerance, intraoperative cardiovascular liability and silent myocardial ischemia. Being important its recognition, quantitative test to evaluate the cardiovascular funtion, to value its evolution and the effects of the treatment ahould be done, being the most used, the hearth rate response to standing test, and teh valsalva maneuver. the handling of this entity is done improving control of glucose blood levels its the most effective way to prevent the cardiovascular autonomic neuropathy in the diabetic patients.

  11. Comparison of three controllers applied to helicopter vibration

    Science.gov (United States)

    Leyland, Jane A.

    1992-01-01

    A comparison was made of the applicability and suitability of the deterministic controller, the cautious controller, and the dual controller for the reduction of helicopter vibration by using higher harmonic blade pitch control. A randomly generated linear plant model was assumed and the performance index was defined to be a quadratic output metric of this linear plant. A computer code, designed to check out and evaluate these controllers, was implemented and used to accomplish this comparison. The effects of random measurement noise, the initial estimate of the plant matrix, and the plant matrix propagation rate were determined for each of the controllers. With few exceptions, the deterministic controller yielded the greatest vibration reduction (as characterized by the quadratic output metric) and operated with the greatest reliability. Theoretical limitations of these controllers were defined and appropriate candidate alternative methods, including one method particularly suitable to the cockpit, were identified.

  12. Durability of commercial aircraft and helicopter composite structures

    International Nuclear Information System (INIS)

    The development of advanced composite technology during the past decade is discussed. Both secondary and primary components fabricated with boron, graphite, and Kevlar composites are evaluated. Included are spoilers, rudders, and fairings on commercial transports, boron/epoxy reinforced wing structure on C-130 military transports, and doors, fairings, tail rotors, vertical fins, and horizontal stabilizers on commercial helicopters. The development of composite structures resulted in advances in design and manufacturing technology for secondary and primary composite structures for commercial transports. Design concepts and inspection and maintenance results for the components in service are reported. The flight, outdoor ground, and controlled laboratory environmental effects on composites were also determined. Effects of moisture absorption, ultraviolet radiation, aircraft fuels and fluids, and sustained tensile stress are included. Critical parameters affecting the long term durability of composite materials are identified

  13. Computation of helicopter rotor acoustics in forward flight

    Science.gov (United States)

    Strawn, Roger; Biswas, Rupak

    1994-01-01

    This paper presents a new method for computing acoustic signals from helicopter rotors in forward flight. The aerodynamic and acoustic solutions in the near field are computed with a finite-difference solver for the Euler equations. A nonrotating cylindrical Kirchhoff surface is then placed around the entire rotor system. This Kirchhoff surface moves subsonically with the rotor in forward flight. The finite-difference solution is interpolated onto this cylindrical surface at each time step and a Kirchhoff integration is used to carry the acoustic signal to the far field. Computed values for high-speed impulsive noise show excellent agreement with model-rotor and flight-test experimental data. Results from the new method offer high accuracy with reasonable computer resource requirements.

  14. Nondestructive evaluation of helicopter rotor blades using guided Lamb modes.

    Science.gov (United States)

    Chakrapani, Sunil Kishore; Barnard, Daniel; Dayal, Vinay

    2014-03-01

    This paper presents an application for turning and direct modes in a complex composite laminate structure. The propagation and interaction of turning modes and fundamental Lamb modes are investigated in the skin, spar and web sections of a helicopter rotor blade. Finite element models were used to understand the various mode conversions at geometric discontinuities such as web-spar joints. Experimental investigation was carried out with the help of air coupled ultrasonic transducers. The turning and direct modes were confirmed with the help of particle displacements and velocities. Experimental B-Scans were performed on damaged and undamaged samples for qualitative and quantitative assessment of the structure. A strong correlation between the numerical and experimental results was observed and reported. PMID:24210414

  15. Influence of Helicopter Rotor Wake Modeling on Blade Airload Predictions

    Directory of Open Access Journals (Sweden)

    Christos K. Zioutis

    2010-01-01

    Full Text Available In the present paper a computational investigation is made about the efficiency ofrecently developed mathematical models for specific aerodynamic phenomena ofthe complicated helicopter rotor flowfield. A developed computational procedureis used, based on a Lagrangian type, Vortex Element Method. The free vorticalwake geometry and rotor airloads are computed. The efficiency of special modelsconcerning vortex core structure, vorticity diffusion and vortex straining regardingrotor airloads prediction is tested. Investigations have also been performed inorder to assess a realistic value for empirical factors included in vorticity diffusionmodels. The benefit of using multiple vortex line to simulate trailing wake vorticitybehind blade span instead of isolated lines or vortex sheets, despite theircomputational cost, is demonstrated with the developed wake relaxation method.The computational results are compared with experimental data from wind tunneltests, performed during joined European research programs.

  16. Aeroelastic optimization of an advanced geometry helicopter rotor

    Science.gov (United States)

    Ganguli, Ranjan; Chopra, Inderjit

    1992-01-01

    Sensitivity derivatives of blade loads and aeroelastic stability of a helicopter rotor in forward flight are calculated as an integral part of a basic aeroelastic analysis using a direct analytical approach. Design variables include nonstructural mass and its placement, chordwise offset of blade center of gravity and aerodynamic center from the elastic axis, blade bending stiffnesses (flap, lag, torsion), and tip geometry (sweep, anhedral, pretwist and planform taper). By means of a sensitivity study, the importance of different design variables on oscillatory hub loads and damping of blade modes is examined. Aeroelastic and sensitivity analyses of the rotor based on a finite element method in space and time are linked with automated optimization algorithms to perform optimization studies of rotor blades. Optimum design solutions, calculated for a four-bladed, soft-inplane hingeless rotor achieved a reduction of 25-60 percent of all 4/rev loads.

  17. Stability Analysis of the Slowed-Rotor Compound Helicopter Configuration

    Science.gov (United States)

    Floros, Matthew W.; Johnson, Wayne

    2007-01-01

    The stability and control of rotors at high advance ratio are considered. Teetering, articulated, gimbaled, and rigid hub types are considered for a compound helicopter (rotor and fixed wing). Stability predictions obtained using an analytical rigid flapping blade analysis, a rigid blade CAMRAD II model, and an elastic blade CAMRAD II model are compared. For the flapping blade analysis, the teetering rotor is the most stable, showing no instabilities up to an advance ratio of 3 and a Lock number of 18. A notional elastic blade model of a teetering rotor is unstable at an advance ratio of 1.5, independent of pitch frequency. Analysis of the trim controls and blade flapping shows that for small positive collective pitch, trim can be maintained without excessive control input or flapping angles.

  18. Application of optimization methods to helicopter rotor blade design

    Science.gov (United States)

    Chattopadhyay, A.; Walsh, J. L.

    1990-01-01

    A procedure for the minimum weight design of helicopter rotor blades with constraints on multiple coupled flap-lag natural frequencies, autorotational inertia, and centrifugal stress is presented. Optimum designs are obtained for blades with both rectangular and tapered planforms and are compared within a reference blade. The effects of higher-frequency constraints and stress constraints on the optimum blade designs are assessed. The results indicate that there is an increase in blade weight and a significant change in the design variable distributions with an increase in the number of frequency constraints. The inclusion of stress constraints has different effects on the wall thickness distributions of rectangular and tapered blades, but tends to increase the magnitude of the nonstructural segment weight distributions for both blade types.

  19. Optimization of helicopter rotor blade design for minimum vibration

    Science.gov (United States)

    Davis, M. W.

    1984-01-01

    The optimization approach discussed is part of an ongoing effort to develop a general automated procedure for rotor blade design. This procedure can be used to determine the necessary geometric, structural, and material properties of a rotor system to achieve desired objectives relating to vibration, stress, and aerodynamic performance. The approach used for helicopter vibration is emphasized. Based on analytical studies performed at the United Technologies Research Center (UTRC), a simplified vibration analysis was developed to be used in conjunction with a forced response analysis in the optimization process. This simplified analysis improves the efficiency of the design process significantly. Results of applying this approach to the design of an existing rotor blade model are presented.

  20. Distribution of Acoustic Power Spectra for an Isolated Helicopter Fuselage

    Directory of Open Access Journals (Sweden)

    Kusyumov A.N.

    2016-01-01

    Full Text Available The broadband aerodynamic noise can be studied, assuming isotropic flow, turbulence and decay. Proudman’s approach allows practical calculations of noise based on CFD solutions of RANS or URANS equations at the stage of post processing and analysis of the solution. Another aspect is the broadband acoustic spectrum and the distribution of acoustic power over a range of frequencies. The acoustic energy spectrum distribution in isotropic turbulence is non monotonic and has a maximum at a certain value of Strouhal number. In the present work the value of acoustic power peak frequency is determined using a prescribed form of acoustic energy spectrum distribution presented in papers by S. Sarkar and M. Y. Hussaini and by G. M. Lilley. CFD modelling of the flow around isolated helicopter fuselage model was considered using the HMB CFD code and the RANS equations.

  1. Data acquisition and processing - helicopter radiometric survey, Krageroe, 1998

    International Nuclear Information System (INIS)

    On 07 October 1998 a helicopter radiometric survey was flown in the vicinity of Krageroe municipality. The purpose of the survey was to provide radiometric information to help assess radon hazard from radioactive rocks in the area. A total of 60 line-kilometres of radiometric data were acquired in a single flight, covering an area of approximately 3 square km with a 50-m line spacing. The data were collected by Geological Survey of Norway (NGU) personnel and processed at NGU. Radiometric data were reduced using the three-channel procedure recommended by the International Atomic Energy Association. All data were gridded using square cells with 30-m sides and geophysical maps were produced at a scale of 1:5000. This report covers aspects of data acquisition and processing (Author)

  2. Alerting prefixes for speech warning messages. [in helicopters

    Science.gov (United States)

    Bucher, N. M.; Voorhees, J. W.; Karl, R. L.; Werner, E.

    1984-01-01

    A major question posed by the design of an integrated voice information display/warning system for next-generation helicopter cockpits is whether an alerting prefix should precede voice warning messages; if so, the characteristics desirable in such a cue must also be addressed. Attention is presently given to the results of a study which ascertained pilot response time and response accuracy to messages preceded by either neutral cues or the cognitively appropriate semantic cues. Both verbal cues and messages were spoken in direct, phoneme-synthesized speech, and a training manipulation was included to determine the extent to which previous exposure to speech thus produced facilitates these messages' comprehension. Results are discussed in terms of the importance of human factors research in cockpit display design.

  3. Gulf of Mexico Helicopter Offshore System Technologies Recommended Development Path

    Science.gov (United States)

    Koenke, Edmund J.; Williams, Larry; Calafa, Caesar

    1999-01-01

    The National Aeronautics and Space Administration (NASA) Advanced Air Transportation Technologies (AATT) project in cooperation with the Department of Transportation (DOT) Volpe National Transportation Systems Center (VNTSC) contracted with the System Resources Corporation (SRC) for the evaluation of the existing environment and the identification of user and service provider needs in the Gulf of Mexico low-altitude Offshore Sector. The results of this contractor activity are reported in the Gulf of Mexico Helicopter Offshore System Technologies Engineering Needs Assessment. A recommended system design and transition strategy was then developed to satisfy the identified needs within the constraints of the environment. This work, also performed under contract to NASA, is the subject of this report.

  4. The inclusion of rotor dynamics in controller design for helicopters.

    Science.gov (United States)

    Hall, W. E., Jr.; Bryson, A. E., Jr.

    1972-01-01

    State-feedback-controllers and state-estimators (filters) are designed for the roll-pitch-horizontal motions of a helicopter near hover, using a new quadratic synthesis technique. One model (tenth order) uses a dynamic model of the rotor, whereas the other model (sixth order) assumes the rotor can be tilted instantaneously. It is shown that, for tight control, neglecting the rotor dynamics in designing the autopilot can produce unstable closed-loop response on the model that includes rotor dynamics. Two filters are designed to use only fuselage sensors and two are designed to use both fuselage and rotor sensors. It is shown that rotor states can be estimated with sufficient accuracy using only fuselage sensors so that it does not seem worthwhile to use rotor sensors. The mean square response of the vehicle to a gusty, random wind, using several different filter/state-feedback compensators, is shown to be satisfactory.

  5. Helicopter Surveys for Locating Wells and Leaking Oilfield Infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Hammack, R.W.; Veloski, G.A.; Hodges, G. (Fugro Airborne Surveys)

    2006-10-01

    Prior to the injection of CO2 into geological formations, either for enhanced oil recovery or for CO2 sequestration, it is necessary to locate wells that perforate the target formation and are within the radius of influence for planned injection wells. Locating and plugging wells is necessary because improperly plugged well bores provide the most rapid route for CO2 escape to the surface. This paper describes the implementation and evaluation of helicopter and ground-based well detection strategies at a 100+ year old oilfield in Wyoming where a CO2 flood is planned. This project was jointly funded by the U.S. Department of Energy’s National Energy Technology Laboratory and Fugro Airborne Surveys

  6. Pipes's distribution by helicopter in Amazonian forest

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Gilberto R.; Machado, Otto L.M.; Gomes, Antonio E. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2009-12-19

    The innumerable logistical problems encountered during the implementation of the gas pipeline Urucu - Coari - Manaus, located in the Amazon forest, connecting the Base Operations Geologist Pedro de Moura in Urucu to the refinery Isaac Sabba - Reman, in the city of Manaus, contributed considerably for PETROBRAS to seek non conventional solutions in the construction and assembly of pipelines in our country. Among these solutions, there is the technique of distributing pipes through cargo helicopters. The need for the usage of this technique, innovative in Brazil, comes from the lack and/or insufficiency of land access from Solimoes River to the gas pipeline main route, and the large quantities of flooded areas and/or flood plain, and also the type of soil, that together with the high index of rainfall in the region, makes the soil fully inappropriate to the traffic of heavy equipment. (author)

  7. Smart helicopter rotors optimization and piezoelectric vibration control

    CERN Document Server

    Ganguli, Ranjan; Viswamurthy, Sathyamangalam Ramanarayanan

    2016-01-01

    Exploiting the properties of piezoelectric materials to minimize vibration in rotor-blade actuators, this book demonstrates the potential of smart helicopter rotors to achieve the smoothness of ride associated with jet-engined, fixed-wing aircraft. Vibration control is effected using the concepts of trailing-edge flaps and active-twist. The authors’ optimization-based approach shows the advantage of multiple trailing-edge flaps and algorithms for full-authority control of dual trailing-edge-flap actuators are presented. Hysteresis nonlinearity in piezoelectric stack actuators is highlighted and compensated by use of another algorithm. The idea of response surfaces provides for optimal placement of trailing-edge flaps. The concept of active twist involves the employment of piezoelectrically induced shear actuation in rotating beams. Shear is then demonstrated for a thin-walled aerofoil-section rotor blade under feedback-control vibration minimization. Active twist is shown to be significant in reducing vibra...

  8. Durability of commercial aircraft and helicopter composite structures

    Science.gov (United States)

    Dexter, H. B.

    1982-01-01

    The development of advanced composite technology during the past decade is discussed. Both secondary and primary components fabricated with boron, graphite, and Kevlar composites are evaluated. Included are spoilers, rudders, and fairings on commercial transports, boron/epoxy reinforced wing structure on C-130 military transports, and doors, fairings, tail rotors, vertical fins, and horizontal stabilizers on commercial helicopters. The development of composite structures resulted in advances in design and manufacturing technology for secondary and primary composite structures for commercial transports. Design concepts and inspection and maintenance results for the components in service are reported. The flight, outdoor ground, and controlled laboratory environmental effects on composites were also determined. Effects of moisture absorption, ultraviolet radiation, aircraft fuels and fluids, and sustained tensile stress are included. Critical parameters affecting the long term durability of composite materials are identified.

  9. Analysis of helicopter blade vortex structure by laser velocimetry

    Science.gov (United States)

    Boutier, A.; Lefèvre, J.; Micheli, F.

    1996-05-01

    In descent flight, helicopter external noise is mainly generated by the Blade Vortex Interaction (BVI). To under-stand the dynamics of this phenomenon, the vortex must be characterized before its interaction with the blade, which means that its viscous core radius, its strength and its distance to the blade have to be determined by non-intrusive measurement techniques. As part of the HART program (Higher Harmonic Control Aeroacoustic Rotor Test, jointly conducted by US Army, NASA, DLR, DNW and ONERA), a series of tests have been made in the German Dutch Wind Tunnel (DNW) on a helicopter rotor with 2 m long blades, rotating at 1040 rpm; several flight configurations, with an advance ratio of 0.15 and a shaft angle of 5.3°, have been studied with different higher harmonic blade pitch angles superposed on the conventional one (corresponding to the baseline case). The flow on the retreating side has been analyzed with an especially designed 3D laser velocimeter, and, simultaneously, the blade tip attitude has been determined in order to get the blade-vortex miss distance, which is a crucial parameter in the noise reduction. A 3D laser velocimeter, in backscatter mode with a working distance of 5 m, was installed on a platform 9 m high, and flow seeding with submicron incense smoke was achieved in the settling chamber using a remotely controlled displacement device. Acquisition of instantaneous velocity vectors by an IFA 750 yielded mean velocity and turbulence maps across the vortex as well as the vortex position, intensity and viscous radius. The blade tip attitude (altitude, jitter, angle of incidence) was recorded by the TART method (Target Attitude in Real Time) which makes use of a CCD camera on which is formed the image of two retroreflecting targets attached to the blade tip and lighted by a flash lamp. In addition to the mean values of the aforementioned quantities, spectra of their fluctuations have been established up to 8 Hz.

  10. Helicopter flights with night-vision goggles: Human factors aspects

    Science.gov (United States)

    Brickner, Michael S.

    1989-01-01

    Night-vision goggles (NVGs) and, in particular, the advanced, helmet-mounted Aviators Night-Vision-Imaging System (ANVIS) allows helicopter pilots to perform low-level flight at night. It consists of light intensifier tubes which amplify low-intensity ambient illumination (star and moon light) and an optical system which together produce a bright image of the scene. However, these NVGs do not turn night into day, and, while they may often provide significant advantages over unaided night flight, they may also result in visual fatigue, high workload, and safety hazards. These problems reflect both system limitations and human-factors issues. A brief description of the technical characteristics of NVGs and of human night-vision capabilities is followed by a description and analysis of specific perceptual problems which occur with the use of NVGs in flight. Some of the issues addressed include: limitations imposed by a restricted field of view; problems related to binocular rivalry; the consequences of inappropriate focusing of the eye; the effects of ambient illumination levels and of various types of terrain on image quality; difficulties in distance and slope estimation; effects of dazzling; and visual fatigue and superimposed symbology. These issues are described and analyzed in terms of their possible consequences on helicopter pilot performance. The additional influence of individual differences among pilots is emphasized. Thermal imaging systems (forward looking infrared (FLIR)) are described briefly and compared to light intensifier systems (NVGs). Many of the phenomena which are described are not readily understood. More research is required to better understand the human-factors problems created by the use of NVGs and other night-vision aids, to enhance system design, and to improve training methods and simulation techniques.

  11. Rapid determination of soil contamination by helicopter gamma ray spectroscopy

    International Nuclear Information System (INIS)

    Specific aerial nuclide measurements of surface soil contamination were performed after the Chernobyl accident in the southern part of Germany. A helicopter equipped with a gamma ray spectroscopic system including a HPGe detector (50% relative efficiency) and 3 NaI(Tl)-detectors (volume 12 l) was used. A detailed description is given of the complete measuring system which can also be used for detection of gamma sources, e.g. radioactive fragments of nuclear powered satellites. At an altitude of 100 m, a soil contamination of several kBq/m2 for 134Cs and 137Cs can be measured for 60 s at a helicopter speed of 100 km/h. For detection of point gamma sources, the NaI(Tl)-detector was used. Assuming a line spacing of 300 m and a speed of 100 km/h, an area of about 30 km2 can be surveyed per hour. Thus 60Co-sources of some GBq activity can be detected. The system was practically applied for the first time for measuring the man-made radionuclides. The chosen distance between the routes was 10 km, and measuring time - 60 s for each spectrum corresponding to a flight path distance of about 2.2 km over which the average soil contamination was determined. The measured 137Cs values of up to 25 kBq/m2 are in good agreement with the results obtained by other methods (in-situ-spectrometry, measurements of soil samples). The aerial measuring system was also tested in the former USSR, in a region north of Chernobyl, with nuclide deposition values of up to 2 MBq/m2. 7 figs., 2 refs. (orig.)

  12. Results of the noise measurement program on a standard and modified OH-6A helicopter

    Science.gov (United States)

    Henderson, H. R.; Peegg, R. J.; Hilton, D. A.

    1973-01-01

    A field noise measurement program has been conducted on a standard OH-6A helicopter and one that had been modified by reducing the rotor speed, altering rotor tip shape, and treating the engine exhaust and inlet to reduce the external noise levels. The modifications consisted of extensive aircraft design changes resulting in substantial noise reductions following state-of-art noise reduction techniques. The purpose of this study was to document the ground noise characteristics of each helicopter during flyover, hover, landing, and take-off operations. Based on an analysis of the measured results, the average of the overall on-track noise levels of the final modified helicopter was approximately 14 db lower than that for the standard helicopter. Narrow-band-spectra data of the hovering helicopter show a reduction in the overall noise due to the reductions achieved for the lifting main and antitorque tail rotor, engine exhaust, and gear box noise for the modified helicopter. The noise results of the test program are found to correlate generally with noise measurements made previously on this type of aircraft.

  13. Stable Hovering Flight for a Small Unmanned Helicopter Using Fuzzy Control

    Directory of Open Access Journals (Sweden)

    Arbab Nighat Khizer

    2014-01-01

    Full Text Available Stable hover flight control for small unmanned helicopter under light air turbulent environment is presented. Intelligent fuzzy logic is chosen because it is a nonlinear control technique based on expert knowledge and is capable of handling sensor created noise and contradictory inputs commonly encountered in flight control. The fuzzy nonlinear control utilizes these distinct qualities for attitude, height, and position control. These multiple controls are developed using two-loop control structure by first designing an inner-loop controller for attitude angles and height and then by establishing outer-loop controller for helicopter position. The nonlinear small unmanned helicopter model used comes from X-Plane simulator. A simulation platform consisting of MATLAB/Simulink and X-Plane© flight simulator was introduced to implement the proposed controls. The main objective of this research is to design computationally intelligent control laws for hovering and to test and analyze this autopilot for small unmanned helicopter model on X-Plane under ideal and mild turbulent condition. Proposed fuzzy flight controls are validated using an X-Plane helicopter model before being embedded on actual helicopter. To show the effectiveness of the proposed fuzzy control method and its ability to cope with the external uncertainties, results are compared with a classical PD controller. Simulated results show that two-loop fuzzy controllers have a good ability to establish stable hovering for a class of unmanned rotorcraft in the presence of light turbulent environment.

  14. Autonomous navigation system and method

    Science.gov (United States)

    Bruemmer, David J. [Idaho Falls, ID; Few, Douglas A. [Idaho Falls, ID

    2009-09-08

    A robot platform includes perceptors, locomotors, and a system controller, which executes instructions for autonomously navigating a robot. The instructions repeat, on each iteration through an event timing loop, the acts of defining an event horizon based on the robot's current velocity, detecting a range to obstacles around the robot, testing for an event horizon intrusion by determining if any range to the obstacles is within the event horizon, and adjusting rotational and translational velocity of the robot accordingly. If the event horizon intrusion occurs, rotational velocity is modified by a proportion of the current rotational velocity reduced by a proportion of the range to the nearest obstacle and translational velocity is modified by a proportion of the range to the nearest obstacle. If no event horizon intrusion occurs, translational velocity is set as a ratio of a speed factor relative to a maximum speed.

  15. Autonomous Spacecraft Navigation With Pulsars

    CERN Document Server

    Becker, Werner; Jessner, Axel

    2013-01-01

    An external reference system suitable for deep space navigation can be defined by fast spinning and strongly magnetized neutron stars, called pulsars. Their beamed periodic signals have timing stabilities comparable to atomic clocks and provide characteristic temporal signatures that can be used as natural navigation beacons, quite similar to the use of GPS satellites for navigation on Earth. By comparing pulse arrival times measured on-board a spacecraft with predicted pulse arrivals at a reference location, the spacecraft position can be determined autonomously and with high accuracy everywhere in the solar system and beyond. The unique properties of pulsars make clear already today that such a navigation system will have its application in future astronautics. In this paper we describe the basic principle of spacecraft navigation using pulsars and report on the current development status of this novel technology.

  16. Sleep in trigeminal autonomic cephalagias

    DEFF Research Database (Denmark)

    Barløse, Mads; Lund, Nunu; Jensen, Rigmor Højland

    2014-01-01

    PURPOSE OF REVIEW: Sleep and cluster headache (CH) are believed to be interconnected but the precise relation to the other trigeminal autonomic cephalalgias (TACs) is uncertain and complex. A better understanding of these relations may eventually lead to a clarification of the underlying mechanisms...... and eventually to more effective therapeutic regimens. This review aims to evaluate the existing literature on the subject of TACs and sleep. An association between episodic CH and distinct macrostructural sleep phases, especially the relation to rapid eye movement (REM) sleep, has been described in...... some older studies but could not be confirmed in other, more recent studies. Investigations into the microstructure of sleep in these patients are lacking. Only a few case reports exist on the relation between sleep and other TACs. SUMMARY: Recent studies do not find an association between CH and REM...

  17. Digital autonomous terminal access communications

    Science.gov (United States)

    Novacki, S.

    1987-01-01

    A significant problem for the Bus Monitor Unit is to identify the source of a given transmission. This problem arises from the fact that the label which identifies the source of the transmission as it is put into the bus is intercepted by the Digital Autonomous Terminal Access Communications (DATAC) terminal and removed from the transmission. Thus, a given subsystem will see only data associated with a label and never the identifying label itself. The Bus Monitor must identify the source of the transmission so as to be able to provide some type of error identification/location in the event that some problem with the data transmission occurs. Steps taken to alleviate this problem by modifications to the DATAC terminal are discussed.

  18. An Autonomous Flight Safety System

    Science.gov (United States)

    Bull, James B.; Lanzi, Raymond J.

    2007-01-01

    The Autonomous Flight Safety System (AFSS) being developed by NASA s Goddard Space Flight Center s Wallops Flight Facility and Kennedy Space Center has completed two successful developmental flights and is preparing for a third. AFSS has been demonstrated to be a viable architecture for implementation of a completely vehicle based system capable of protecting life and property in event of an errant vehicle by terminating the flight or initiating other actions. It is capable of replacing current human-in-the-loop systems or acting in parallel with them. AFSS is configured prior to flight in accordance with a specific rule set agreed upon by the range safety authority and the user to protect the public and assure mission success. This paper discusses the motivation for the project, describes the method of development, and presents an overview of the evolving architecture and the current status.

  19. Testbed for an autonomous system

    Science.gov (United States)

    Dikshit, Piyush; Guimaraes, Katia; Ramamurthy, Maya; Agrawala, Ashok K.; Larsen, Ronald L.

    1989-01-01

    In previous works we have defined a general architectural model for autonomous systems, which can easily be mapped to describe the functions of any automated system (SDAG-86-01), and we illustrated that model by applying it to the thermal management system of a space station (SDAG-87-01). In this note, we will further develop that application and design the detail of the implementation of such a model. First we present the environment of our application by describing the thermal management problem and an abstraction, which was called TESTBED, that includes a specific function for each module in the architecture, and the nature of the interfaces between each pair of blocks.

  20. Autonomous Infrastructure for Observatory Operations

    Science.gov (United States)

    Seaman, R.

    This is an era of rapid change from ancient human-mediated modes of astronomical practice to a vision of ever larger time domain surveys, ever bigger "big data", to increasing numbers of robotic telescopes and astronomical automation on every mountaintop. Over the past decades, facets of a new autonomous astronomical toolkit have been prototyped and deployed in support of numerous space missions. Remote and queue observing modes have gained significant market share on the ground. Archives and data-mining are becoming ubiquitous; astroinformatic techniques and virtual observatory standards and protocols are areas of active development. Astronomers and engineers, planetary and solar scientists, and researchers from communities as diverse as particle physics and exobiology are collaborating on a vast range of "multi-messenger" science. What then is missing?

  1. Design of Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Tadahiro Hyakudome

    2011-03-01

    Full Text Available There are concerns about the impact that global warming will have on our environment, and which will inevitably result in expanding deserts and rising water levels. While a lot of underwater vehicles are utilized, AUVs (Autonomous Underwater Vehicle were considered and chosen, as the most suitable tool for conduction survey concerning these global environmental problems. AUVs can comprehensive survey because the vehicle does not have to be connected to the support vessel by tether cable. When such underwater vehicles are made, it is necessary to consider about the following things. 1 Seawater and Water Pressure Environment, 2 Sink, 3 There are no Gas or Battery Charge Stations, 4 Global Positioning System cannot use, 5 Radio waves cannot use. In the paper, outline of above and how deal about it are explained.

  2. Autonomous Industrial Mobile Manipulation (AIMM)

    DEFF Research Database (Denmark)

    Hvilshøj, Mads; Bøgh, Simon; Nielsen, Oluf Skov;

    2012-01-01

    ; sustainability, configuration, adaptation, autonomy, positioning, manipulation and grasping, robot-robot interaction, human-robot interaction, process quality, dependability, and physical properties. Findings - The concise yet comprehensive review provides both researchers (academia) and practitioners (industry......Purpose - The purpose of this paper is to provide a review of the interdisciplinary research field Autonomous Industrial Mobile Manipulation (AIMM), with an emphasis on physical implementations and applications. Design/methodology/approach - Following an introduction to AIMM, this paper...... investigates the missing links and gaps between the research and developments efforts and the real-world application requirements, in order to bring the AIMM technology from laboratories to manufacturing environments. The investigation is based on 12 general application requirements for robotics...

  3. APDS: Autonomous Pathogen Detection System

    Energy Technology Data Exchange (ETDEWEB)

    Langlois, R G; Brown, S; Burris, L; Colston, B; Jones, L; Makarewicz, T; Mariella, R; Masquelier, D; McBride, M; Milanovich, F; Masarabadi, S; Venkateswaran, K; Marshall, G; Olson, D; Wolcott, D

    2002-02-14

    An early warning system to counter bioterrorism, the Autonomous Pathogen Detection System (APDS) continuously monitors the environment for the presence of biological pathogens (e.g., anthrax) and once detected, it sounds an alarm much like a smoke detector warns of a fire. Long before September 11, 2001, this system was being developed to protect domestic venues and events including performing arts centers, mass transit systems, major sporting and entertainment events, and other high profile situations in which the public is at risk of becoming a target of bioterrorist attacks. Customizing off-the-shelf components and developing new components, a multidisciplinary team developed APDS, a stand-alone system for rapid, continuous monitoring of multiple airborne biological threat agents in the environment. The completely automated APDS samples the air, prepares fluid samples in-line, and performs two orthogonal tests: immunoassay and nucleic acid detection. When compared to competing technologies, APDS is unprecedented in terms of flexibility and system performance.

  4. Wireless autonomous device data transmission

    Science.gov (United States)

    Sammel, Jr., David W. (Inventor); Cain, James T. (Inventor); Mickle, Marlin H. (Inventor); Mi, Minhong (Inventor)

    2013-01-01

    A method of communicating information from a wireless autonomous device (WAD) to a base station. The WAD has a data element having a predetermined profile having a total number of sequenced possible data element combinations. The method includes receiving at the WAD an RF profile transmitted by the base station that includes a triggering portion having a number of pulses, wherein the number is at least equal to the total number of possible data element combinations. The method further includes keeping a count of received pulses and wirelessly transmitting a piece of data, preferably one bit, to the base station when the count reaches a value equal to the stored data element's particular number in the sequence. Finally, the method includes receiving the piece of data at the base station and using the receipt thereof to determine which of the possible data element combinations the stored data element is.

  5. Mission-based guidance system design for autonomous UAVs

    Science.gov (United States)

    Moon, Jongki

    The advantages of UAVs in the aviation arena have led to extensive research activities on autonomous technology of UAVs to achieve specific mission objectives. This thesis mainly focuses on the development of a mission-based guidance system. Among various missions expected for future needs, autonomous formation flight (AFF) and obstacle avoidance within safe operation limits are investigated. In the design of an adaptive guidance system for AFF, the leader information except position is assumed to be unknown to a follower. Thus, the only measured information related to the leader is the line-of-sight (LOS) range and angle. Adding an adaptive element with neural networks into the guidance system provides a capability to effectively handle leader's velocity changes. Therefore, this method can be applied to the AFF control systems that use a passive sensing method. In this thesis, an adaptive velocity command guidance system and an adaptive acceleration command guidance system are developed and presented. Since relative degrees of the LOS range and angle are different depending on the outputs from the guidance system, the architecture of the guidance system changes accordingly. Simulations and flight tests are performed using the Georgia Tech UAV helicopter, the GTMax, to evaluate the proposed guidance systems. The simulation results show that the neural network (NN) based adaptive element can improve the tracking performance by effectively compensating for the effect of unknown dynamics. It has also been shown that the combination of an adaptive velocity command guidance system and the existing GTMax autopilot controller performs better than the combination of an adaptive acceleration command guidance system and the GTMax autopilot controller. The successful flight evaluation using an adaptive velocity command guidance system clearly shows that the adaptive guidance control system is a promising solution for autonomous formation flight of UAVs. In addition, an

  6. Current challenges in autonomous vehicle development

    Science.gov (United States)

    Connelly, J.; Hong, W. S.; Mahoney, R. B., Jr.; Sparrow, D. A.

    2006-05-01

    The field of autonomous vehicles is a rapidly growing one, with significant interest from both government and industry sectors. Autonomous vehicles represent the intersection of artificial intelligence (AI) and robotics, combining decision-making with real-time control. Autonomous vehicles are desired for use in search and rescue, urban reconnaissance, mine detonation, supply convoys, and more. The general adage is to use robots for anything dull, dirty, dangerous or dumb. While a great deal of research has been done on autonomous systems, there are only a handful of fielded examples incorporating machine autonomy beyond the level of teleoperation, especially in outdoor/complex environments. In an attempt to assess and understand the current state of the art in autonomous vehicle development, a few areas where unsolved problems remain became clear. This paper outlines those areas and provides suggestions for the focus of science and technology research. The first step in evaluating the current state of autonomous vehicle development was to develop a definition of autonomy. A number of autonomy level classification systems were reviewed. The resulting working definitions and classification schemes used by the authors are summarized in the opening sections of the paper. The remainder of the report discusses current approaches and challenges in decision-making and real-time control for autonomous vehicles. Suggested research focus areas for near-, mid-, and long-term development are also presented.

  7. Cardiovascular autonomic dysfunctions and sleep disorders.

    Science.gov (United States)

    Calandra-Buonaura, Giovanna; Provini, Federica; Guaraldi, Pietro; Plazzi, Giuseppe; Cortelli, Pietro

    2016-04-01

    Animal and human studies have shown that disorders of the autonomic nervous system may influence sleep physiology. Conversely, sleep disorders may be associated with autonomic dysfunctions. The current review describes the clinical presentation, supposed pathogenetic mechanisms and the diagnostic and prognostic implications of impaired cardiovascular autonomic control in sleep disorders. This dysfunction may result from a common pathogenetic mechanism affecting both autonomic cardiovascular control and sleep, as in fatal familial insomnia, or it may be mainly caused by the sleep disorder, as observed in obstructive sleep apnoea. For other sleep disorders, like primary insomnia, restless legs syndrome, narcolepsy type 1 and rapid eye movement sleep behaviour disorder, the causal link with the autonomic dysfunction and its possible impact on health remains unsettled. Given its clinical implications, most of the data available suggest that a systematic assessment of the association between sleep disorders and impaired autonomic control of the cardiovascular system is warranted. Understanding the mechanism of this association may also yield insights into the interaction between the autonomic nervous system and sleep. PMID:26146026

  8. 基于2点RANSAC的无人直升机单目视觉SLAM%Monocular Visual SLAM of Unmanned Helicopter Based on 2-point RANSAC

    Institute of Scientific and Technical Information of China (English)

    徐伟杰; 李平; 韩波

    2012-01-01

    1点随机抽样一致性(RANSAC)算法是一种准确度高、计算量小的数据关联算法,但是其在摄像机多个轴上的角速度都快速变化时会失效,用在以无人直升机为载体的单目视觉同步定位与地图构建(SLAM)上存在滤波发散的风险.针对该问题,提出2点RANSAC算法,结合EKF运动模型的先验信息,用只抽样2个匹配点的RANSAC去除野点.在微小型无人直升机平台上进行了基于2点RANSAC算法的单目视觉SLAM实验,实验结果表明2点RANSAC算法工作可靠,SLAM的位姿估计精度可以达到自主飞行需要.%The 1-point random sample consensus (RANSAC) algorithm is a data association algorithm with high accuracy and low compaction cost. However, it fails when angular velocities around multiple axes of the camera change quickly, and causes the risk of filter divergence when applied to the monocular visual simultaneous localization and mapping (SLAM) of unmanned helicopter. For this problem, 2-point RANSAC algorithm is proposed, which incorporates a priori information from the EKF (extended Kalman filter) motion model, and uses RANSAC, in which only 2 matched points are used for sampling, to remove the outliers. Monocular visual SLAM based on 2-point RANSAC algorithm is performed on a mini unmanned helicopter (MUH) platform. The field-experiment results show that 2-point RANSAC algorithm works reliably, and the SLAM's pose estimation is precise enough for autonomous flight.

  9. Autonomous underwater pipeline monitoring navigation system

    Science.gov (United States)

    Mitchell, Byrel; Mahmoudian, Nina; Meadows, Guy

    2014-06-01

    This paper details the development of an autonomous motion-control and navigation algorithm for an underwater autonomous vehicle, the Ocean Server IVER3, to track long linear features such as underwater pipelines. As part of this work, the Nonlinear and Autonomous Systems Laboratory (NAS Lab) developed an algorithm that utilizes inputs from the vehicles state of the art sensor package, which includes digital imaging, digital 3-D Sidescan Sonar, and Acoustic Doppler Current Profilers. The resulting algorithms should tolerate real-world waterway with episodic strong currents, low visibility, high sediment content, and a variety of small and large vessel traffic.

  10. Autonomous Demand Response for Primary Frequency Regulation

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, Matt; Trudnowski, Daniel J.; Mattix, S.; Dagle, Jeffery E.

    2012-02-28

    The research documented within this report examines the use of autonomous demand response to provide primary frequency response in an interconnected power grid. The work builds on previous studies in several key areas: it uses a large realistic model (i.e., the interconnection of the western United States and Canada); it establishes a set of metrics that can be used to assess the effectiveness of autonomous demand response; and it independently adjusts various parameters associated with using autonomous demand response to assess effectiveness and to examine possible threats or vulnerabilities associated with the technology.

  11. Autonomous Bicycle: The First Self Balanced Ride

    OpenAIRE

    Ånnestad, Dag Christian

    2011-01-01

    The idea of an autonomous bicycle originates from Jens G. Balchen who wanted to make an unmanned autonomous bicycle. The idea was picked up by Amund Skavhaug who extended the idea with the concept of using an inverted pendulum to simulate a leaning rider. The previous attempts to develop a bicycle capable of performing an autonomous ride has so far all ended in failure. The main reason for the Department of Engineering Cybernetics is to develop such a bicycle is for use in recruitment and mot...

  12. Development of a Commercially Viable, Modular Autonomous Robotic Systems for Converting any Vehicle to Autonomous Control

    Science.gov (United States)

    Parish, David W.; Grabbe, Robert D.; Marzwell, Neville I.

    1994-01-01

    A Modular Autonomous Robotic System (MARS), consisting of a modular autonomous vehicle control system that can be retrofit on to any vehicle to convert it to autonomous control and support a modular payload for multiple applications is being developed. The MARS design is scalable, reconfigurable, and cost effective due to the use of modern open system architecture design methodologies, including serial control bus technology to simplify system wiring and enhance scalability. The design is augmented with modular, object oriented (C++) software implementing a hierarchy of five levels of control including teleoperated, continuous guidepath following, periodic guidepath following, absolute position autonomous navigation, and relative position autonomous navigation. The present effort is focused on producing a system that is commercially viable for routine autonomous patrolling of known, semistructured environments, like environmental monitoring of chemical and petroleum refineries, exterior physical security and surveillance, perimeter patrolling, and intrafacility transport applications.

  13. Flight test results of the fuzzy logic adaptive controller-helicopter (FLAC-H)

    Science.gov (United States)

    Wade, Robert L.; Walker, Gregory W.

    1996-05-01

    The fuzzy logic adaptive controller for helicopters (FLAC-H) demonstration is a cooperative effort between the US Army Simulation, Training, and Instrumentation Command (STRICOM), the US Army Aviation and Troop Command, and the US Army Missile Command to demonstrate a low-cost drone control system for both full-scale and sub-scale helicopters. FLAC-H was demonstrated on one of STRICOM's fleet of full-scale rotary-winged target drones. FLAC-H exploits fuzzy logic in its flight control system to provide a robust solution to the control of the helicopter's dynamic, nonlinear system. Straight forward, common sense fuzzy rules governing helicopter flight are processed instead of complex mathematical models. This has resulted in a simplified solution to the complexities of helicopter flight. Incorporation of fuzzy logic reduced the cost of development and should also reduce the cost of maintenance of the system. An adaptive algorithm allows the FLAC-H to 'learn' how to fly the helicopter, enabling the control system to adjust to varying helicopter configurations. The adaptive algorithm, based on genetic algorithms, alters the fuzzy rules and their related sets to improve the performance characteristics of the system. This learning allows FLAC-H to automatically be integrated into a new airframe, reducing the development costs associated with altering a control system for a new or heavily modified aircraft. Successful flight tests of the FLAC-H on a UH-1H target drone were completed in September 1994 at the White Sands Missile Range in New Mexico. This paper discuses the objective of the system, its design, and performance.

  14. Feasibility Study for an Autonomous UAV -Magnetometer System -- Final Report on SERDP SEED 1509:2206

    Energy Technology Data Exchange (ETDEWEB)

    Roelof Versteeg; Mark McKay; Matt Anderson; Ross Johnson; Bob Selfridge; Jay Bennett

    2007-09-01

    Large areas across the United States are potentially contaminated with UXO, with some ranges encompassing tens to hundreds of thousands of acres. Technologies are needed which will allow for cost effective wide area scanning with 1) near 100 % coverage and 2) near 100 % detection of subsurface ordnance or features indicative of subsurface ordnance. The current approach to wide area scanning is a multi-level one, in which medium altitude fixed wing optical imaging is used for an initial site assessment. This assessment is followed with low altitude manned helicopter based magnetometry followed by surface investigations using either towed geophysical sensor arrays or man portable sensors. In order to be effective for small UXO detection, the sensing altitude for magnetic site investigations needs to be on the order of 1 – 3 meters. These altitude requirements means that manned helicopter surveys will generally only be feasible in large, open and relatively flat terrains. While such surveys are effective in mapping large areas relatively fast there are substantial mobilization/demobilization, staffing and equipment costs associated with these surveys (resulting in costs of approximately $100-$150/acre). Surface towed arrays provide high resolution maps but have other limitations, e.g. in their ability to navigate rough terrain effectively. Thus, other systems are needed allowing for effective data collection. An UAV (Unmanned Aerial Vehicle) magnetometer platform is an obvious alternative. The motivation behind such a system is that it would be safer for the operators, cheaper in initial and O&M costs, and more effective in terms of site characterization. However, while UAV data acquisition from fixed wing platforms for large (> 200 feet) stand off distances is relatively straight forward, a host of challenges exist for low stand-off distance (~ 6 feet) UAV geophysical data acquisition. The objective of SERDP SEED 1509:2006 was to identify the primary challenges

  15. Autonomic Dysfunction in Patients with Mild to Moderate Alzheimer's Disease

    DEFF Research Database (Denmark)

    Jensen-Dahm, Christina; Waldemar, Gunhild; Staehelin Jensen, Troels;

    2015-01-01

    BACKGROUND: Autonomic function has received little attention in Alzheimer's disease (AD). AD pathology has an impact on brain regions which are important for central autonomic control, but it is unclear if AD is associated with disturbance of autonomic function. OBJECTIVE: To investigate autonomic...

  16. The noise environment of a school classroom due to the operation of utility helicopters. [acoustic measurements of helicopter noise during flight over building

    Science.gov (United States)

    Hilton, D. A.; Pegg, R. J.

    1974-01-01

    Noise measurements under controlled conditions have been made inside and outside of a school building during flyover operations of four different helicopters. The helicopters were operated at a condition considered typical for a police patrol mission. Flyovers were made at an altitude of 500 ft and an airspeed of 45 miles per hour. During these operations acoustic measurements were made inside and outside of the school building with the windows closed and then open. The outside noise measurements during helicopter flyovers indicate that the outside db(A) levels were approximately the same for all test helicopters. For the windows closed case, significant reductions for the inside measured db(A) values were noted for all overflights. These reductions were approximately 20 db(A); similar reductions were noted in other subjective measuring units. The measured internal db(A) levels with the windows open exceeded published classroom noise criteria values; however, for the windows-closed case they are in general agreement with the criteria values.

  17. Autonomic html interface generator for web applications

    CERN Document Server

    Bassil, Youssef; 10.5121/ijwest.2012.3104

    2012-01-01

    Recent advances in computing systems have led to a new digital era in which every area of life is nearly interrelated with information technology. However, with the trend towards large-scale IT systems, a new challenge has emerged. The complexity of IT systems is becoming an obstacle that hampers the manageability, operability, and maintainability of modern computing infrastructures. Autonomic computing popped up to provide an answer to these ever-growing pitfalls. Fundamentally, autonomic systems are self-configuring, self-healing, self-optimizing, and self-protecting; hence, they can automate all complex IT processes without human intervention. This paper proposes an autonomic HTML web-interface generator based on XML Schema and Style Sheet specifications for self-configuring graphical user interfaces of web applications. The goal of this autonomic generator is to automate the process of customizing GUI web-interfaces according to the ever-changing business rules, policies, and operating environment with th...

  18. An introduction to autonomous control systems

    Science.gov (United States)

    Antsaklis, Panos J.; Passino, Kevin M.; Wang, S. J.

    1991-01-01

    The functions, characteristics, and benefits of autonomous control are outlined. An autonomous control functional architecture for future space vehicles that incorporates the concepts and characteristics described is presented. The controller is hierarchical, with an execution level (the lowest level), coordination level (middle level), and management and organization level (highest level). The general characteristics of the overall architecture, including those of the three levels, are explained, and an example to illustrate their functions is given. Mathematical models for autonomous systems, including 'logical' discrete event system models, are discussed. An approach to the quantitative, systematic modeling, analysis, and design of autonomous controllers is also discussed. It is a hybrid approach since it uses conventional analysis techniques based on difference and differential equations and new techniques for the analysis of the systems described with a symbolic formalism such as finite automata. Some recent results from the areas of planning and expert systems, machine learning, artificial neural networks, and the area restructurable controls are briefly outlined.

  19. AGATE: Autonomous Go and Touch Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation (AGATE, for Autonomous Go And Touch Exploration) will enable single-sol "go and touch" instrument placement from distances of up to five meters for...

  20. Autonomic symptoms in idiopathic REM behavior disorder

    DEFF Research Database (Denmark)

    Ferini-Strambi, Luigi; Oertel, Wolfgang; Dauvilliers, Yves;

    2014-01-01

    Patients with idiopathic REM sleep behavior disorder (iRBD) are at very high risk of developing neurodegenerative synucleinopathies, which are disorders with prominent autonomic dysfunction. Several studies have documented autonomic dysfunction in iRBD, but large-scale assessment of autonomic...... symptoms has never been systematically performed. Patients with polysomnography-confirmed iRBD (318 cases) and controls (137 healthy volunteers and 181 sleep center controls with sleep diagnoses other than RBD) were recruited from 13 neurological centers in 10 countries from 2008 to 2011. A validated scale...... to study the disorders of the autonomic nervous system in Parkinson's disease (PD) patients, the SCOPA-AUT, was administered to all the patients and controls. The SCOPA-AUT consists of 25 items assessing the following domains: gastrointestinal, urinary, cardiovascular, thermoregulatory, pupillomotor...

  1. Autonomic Closure for Large Eddy Simulation

    Science.gov (United States)

    King, Ryan; Hamlington, Peter; Dahm, Werner J. A.

    2015-11-01

    A new autonomic subgrid-scale closure has been developed for large eddy simulation (LES). The approach poses a supervised learning problem that captures nonlinear, nonlocal, and nonequilibrium turbulence effects without specifying a predefined turbulence model. By solving a regularized optimization problem on test filter scale quantities, the autonomic approach identifies a nonparametric function that represents the best local relation between subgrid stresses and resolved state variables. The optimized function is then applied at the grid scale to determine unknown LES subgrid stresses by invoking scale similarity in the inertial range. A priori tests of the autonomic approach on homogeneous isotropic turbulence show that the new approach is amenable to powerful optimization and machine learning methods and is successful for a wide range of filter scales in the inertial range. In these a priori tests, the autonomic closure substantially improves upon the dynamic Smagorinsky model in capturing the instantaneous, statistical, and energy transfer properties of the subgrid stress field.

  2. LEO AUTONOMOUS NAVIGATION BASED ON IMAGE MOTION

    Institute of Scientific and Technical Information of China (English)

    DUANFang; LIUJian-ye; YUFeng

    2005-01-01

    A method of LEO autonomous navigation is presented based on the nonlinear satellite velocity relative to the earth. The velocity is detected by a high-speed camera, with the attitude information detected by a star sensor. Compared with traditional autonomous navigation by landmark identification, the satellite velocity relarive to the earth is obtained by correlativity analysis of images. It does not need to recognize ground objects or views. Since it is not necessary to pre-store the database of ground marks, lots of memory space can be saved.The state and observation equations are constructed, and the filtering is processed by the Kalman filter. Simulation results show that the system has high autonomous navigation precision in LEO autonomous navigation.

  3. Rover: Autonomous concepts for Mars exploration

    Science.gov (United States)

    Baiget, A.; Castets, B.; Chochon, H.; Hayard, M.; Lamarre, H.; Lamothe, A.

    1993-01-01

    The development of a mobile, autonomous vehicle that will be launched towards an unknown planet is considered. The rover significant constraints are: Ariane 5 compatibility, Earth/Mars transfer capability, 1000 km autonomous moving in Mars environment, on board localization, and maximum science capability. Two different types of subsystem were considered: classical subsystems (mechanical and mechanisms, thermal, telecommunications, power, onboard data processing) and robotics subsystem, (perception/navigation, autonomous displacement generation, autonomous localization). The needs of each subsystem were studied in terms of energy and data handling capability, in order to choose an on board architecture which best use the available capability, by means of specialized parts. A compromise must always be done between every subsystem in order to obtain the real need with respect to the goal, for example: between perception/navigation and the motion capability. A compromise must also be found between mechanical assembly and calibration need, which is a real problem.

  4. Integral Twist Actuation of Helicopter Rotor Blades for Vibration Reduction

    Science.gov (United States)

    Shin, SangJoon; Cesnik, Carlos E. S.

    2001-01-01

    Active integral twist control for vibration reduction of helicopter rotors during forward flight is investigated. The twist deformation is obtained using embedded anisotropic piezocomposite actuators. An analytical framework is developed to examine integrally-twisted blades and their aeroelastic response during different flight conditions: frequency domain analysis for hover, and time domain analysis for forward flight. Both stem from the same three-dimensional electroelastic beam formulation with geometrical-exactness, and axe coupled with a finite-state dynamic inflow aerodynamics model. A prototype Active Twist Rotor blade was designed with this framework using Active Fiber Composites as the actuator. The ATR prototype blade was successfully tested under non-rotating conditions. Hover testing was conducted to evaluate structural integrity and dynamic response. In both conditions, a very good correlation was obtained against the analysis. Finally, a four-bladed ATR system is built and tested to demonstrate its concept in forward flight. This experiment was conducted at NASA Langley Tansonic Dynamics Tunnel and represents the first-of-a-kind Mach-scaled fully-active-twist rotor system to undergo forward flight test. In parallel, the impact upon the fixed- and rotating-system loads is estimated by the analysis. While discrepancies are found in the amplitude of the loads under actuation, the predicted trend of load variation with respect to its control phase correlates well. It was also shown, both experimentally and numerically, that the ATR blade design has the potential for hub vibratory load reduction of up to 90% using individual blade control actuation. Using the numerical framework, system identification is performed to estimate the harmonic transfer functions. The linear time-periodic system can be represented by a linear time-invariant system under the three modes of blade actuation: collective, longitudinal cyclic, and lateral cyclic. A vibration

  5. Autonomous intelligent cruise control system

    Science.gov (United States)

    Baret, Marc; Bomer, Thierry T.; Calesse, C.; Dudych, L.; L'Hoist, P.

    1995-01-01

    Autonomous intelligent cruise control (AICC) systems are not only controlling vehicles' speed but acting on the throttle and eventually on the brakes they could automatically maintain the relative speed and distance between two vehicles in the same lane. And more than just for comfort it appears that these new systems should improve the safety on highways. By applying a technique issued from the space research carried out by MATRA, a sensor based on a charge coupled device (CCD) was designed to acquire the reflected light on standard-mounted car reflectors of pulsed laser diodes emission. The CCD is working in a unique mode called flash during transfer (FDT) which allows identification of target patterns in severe optical environments. It provides high accuracy for distance and angular position of targets. The absence of moving mechanical parts ensures high reliability for this sensor. The large field of view and the high measurement rate give a global situation assessment and a short reaction time. Then, tracking and filtering algorithms have been developed in order to select the target, on which the equipped vehicle determines its safety distance and speed, taking into account its maneuvering and the behaviors of other vehicles.

  6. Autonomic Findings in Takotsubo Cardiomyopathy.

    Science.gov (United States)

    Norcliffe-Kaufmann, Lucy; Kaufmann, Horacio; Martinez, Jose; Katz, Stuart D; Tully, Lisa; Reynolds, Harmony R

    2016-01-15

    Takotsubo cardiomyopathy (TC) often occurs after emotional or physical stress. Norepinephrine levels are unusually high in the acute phase, suggesting a hyperadrenergic mechanism. Comparatively little is known about parasympathetic function in patients with TC. We sought to characterize autonomic function at rest and in response to physical and emotional stimuli in 10 women with a confirmed history of TC and 10 age-matched healthy women. Sympathetic and parasympathetic activity was assessed at rest and during baroreflex stimulation (Valsalva maneuver and tilt testing), cognitive stimulation (Stroop test), and emotional stimulation (event recall, patients). Ambulatory blood pressure monitoring and measurement of brachial artery flow-mediated vasodilation were also performed. TC women (tested an average of 37 months after the event) had excessive pressor responses to cognitive stress (Stroop test: p emotional arousal (recall of TC event: p = 0.03 vs baseline). Pressor responses to hemodynamic stimuli were also amplified (Valsalva overshoot: p <0.05) and prolonged (duration: p <0.01) in the TC women compared with controls. Plasma catecholamine levels did not differ between TC women and controls. Indexes of parasympathetic (vagal) modulation of heart rate induced by respiration and cardiovagal baroreflex gain were significantly decreased in the TC women versus controls. In conclusion, even long after the initial episode, women with previous episode of TC have excessive sympathetic responsiveness and reduced parasympathetic modulation of heart rate. Impaired baroreflex control may therefore play a role in TC. PMID:26743349

  7. Mechanical Autonomous Stochastic Heat Engine

    Science.gov (United States)

    Serra-Garcia, Marc; Foehr, André; Molerón, Miguel; Lydon, Joseph; Chong, Christopher; Daraio, Chiara

    2016-07-01

    Stochastic heat engines are devices that generate work from random thermal motion using a small number of highly fluctuating degrees of freedom. Proposals for such devices have existed for more than a century and include the Maxwell demon and the Feynman ratchet. Only recently have they been demonstrated experimentally, using, e.g., thermal cycles implemented in optical traps. However, recent experimental demonstrations of classical stochastic heat engines are nonautonomous, since they require an external control system that prescribes a heating and cooling cycle and consume more energy than they produce. We present a heat engine consisting of three coupled mechanical resonators (two ribbons and a cantilever) subject to a stochastic drive. The engine uses geometric nonlinearities in the resonating ribbons to autonomously convert a random excitation into a low-entropy, nonpassive oscillation of the cantilever. The engine presents the anomalous heat transport property of negative thermal conductivity, consisting in the ability to passively transfer energy from a cold reservoir to a hot reservoir.

  8. Semi-Autonomous Vehicle Project

    Science.gov (United States)

    Stewart, Christopher

    2016-01-01

    The primary objective this summer is "evaluating standards for wireless architecture for the internet of things". The Internet of Things is the network of physical objects or "things" embedded with electronics, software, sensors and network connectivity which enables these objects to collect and exchange data and make decisions based on said data. This was accomplished by creating a semi-autonomous vehicle that takes advantage of multiple sensors, cameras, and onboard computers and combined them with a mesh network which enabled communication across large distances with little to no interruption. The mesh network took advantage of what is known as DTN - Disruption Tolerant Networking which according to NASA is the new communications protocol that is "the first step towards interplanetary internet." The use of DTN comes from the fact that it will store information if an interruption in communications is detected and even forward that information via other relays within range so that the data is not lost. This translates well into the project because as the car moves further away from whatever is sending it commands (in this case a joystick), the information can still be forwarded to the car with little to no loss of information thanks to the mesh nodes around the driving area.

  9. Autonomous gliding entry guidance with

    Directory of Open Access Journals (Sweden)

    Guo Jie

    2015-10-01

    Full Text Available This paper presents a novel three-dimensional autonomous entry guidance for relatively high lift-to-drag ratio vehicles satisfying geographic constraints and other path constraints. The guidance is composed of onboard trajectory planning and robust trajectory tracking. For trajectory planning, a longitudinal sub-planner is introduced to generate a feasible drag-versus-energy profile by using the interpolation between upper boundary and lower boundary of entry corridor to get the desired trajectory length. The associated magnitude of the bank angle can be specified by drag profile, while the sign of bank angle is determined by lateral sub-planner. Two-reverse mode is utilized to satisfy waypoint constraints and dynamic heading error corridor is utilized to satisfy no-fly zone constraints. The longitudinal and lateral sub-planners are iteratively employed until all of the path constraints are satisfied. For trajectory tracking, a novel tracking law based on the active disturbance rejection control is introduced. Finally, adaptability tests and Monte Carlo simulations of the entry guidance approach are performed. Results show that the proposed entry guidance approach can adapt to different entry missions and is able to make the vehicle reach the prescribed target point precisely in spite of geographic constraints.

  10. Autonomic dysregulation in headache patients.

    Science.gov (United States)

    Gass, Jason J; Glaros, Alan G

    2013-12-01

    To analyze autonomic nervous system activity in headache subjects, measurements of heart rate variability (HRV), skin temperature, skin conductance, and respiration were compared to a matched control group. HRV data were recorded in time and frequency domains. Subjects also completed self-report questionnaires assessing psychological distress, fatigue, and sleep dysfunction. Twenty-one headache and nineteen control subjects participated. In the time domain, the number of consecutive R-to-R intervals that varied by more than 50 ms and the standard deviation of the normalized R-to-R intervals, both indices of parasympathetic nervous system activity, were significantly lower in the headache group than the control group. Groups did not differ statistically on HRV measures in the frequency domain. Self-report measures showed significantly increased somatization, hostility, anxiety, symptom distress, fatigue, and sleep problems in the headache group. The results suggest headache subjects have increased sympathetic nervous system activity and decreased parasympathetic activity compared to non-headache control subjects. Headaches subjects also showed greater emotional distress, fatigue, and sleep problems. The results indicate an association between headaches and cardiovascular functioning suggestive of sympathetic nervous system activation in this sample of mixed migraine and tension-type headache sufferers. PMID:23912525

  11. Autonomous Systems Developments and Trends

    CERN Document Server

    Kyamaky, Kyandoghere; Kacprzyk, Janusz

    2012-01-01

    The Workshops on Autonomous Systems emanated from a gathering with the doctoral students of just three chairs at Fernuniversität in Hagen, which we organise twice per year for a number of years now. Their purpose is to discuss on-going research and to create a community spirit. Furthermore, they serve as a means of structuring the students' research processes. The workshop has grown and matured in several respects. The doctoral students presenting their work do not come from a single university anymore, but from three. Besides them and their supervisors, also other scientists became interested in the event and contribute to its programme. Following the model of Advanced Study Institutes, they are available on the premises for relaxed, informal discussions outside the formal sessions. Finally, with the co-sponsorship of Gesellschaft für Informatik, the German Computer Society, and this surprisingly comprehensive volume of contributions published by Springer-Verlag the workshop turned into a visible scientifi...

  12. Environmental data collection using autonomous Wave Gliders

    OpenAIRE

    Hermsdorfer, Kathryn M.

    2014-01-01

    Approved for public release; distribution is unlimited The Sensor Hosting Autonomous Remote Craft (SHARC), also known as Wave Glider, is an autonomous ocean vehicle powered by wave motion. This slow-moving platform makes long-term deployments and environmental data collection feasible, especially in data sparse regions or hazardous environments. The standard SHARC hosts a meteorological station (Airmar PB200) that samples air pressure, temperature, wind speed and wind direction at 1.12 m. ...

  13. A middleware architecture for autonomic software deployment

    OpenAIRE

    Matougui, Mohamed El Amine; LERICHE, Sébastien

    2012-01-01

    International audience Autonomic software deployment in open networked environments such as mobile and ad hoc networks is an open issue. Some solutions to software deployment exist; but, they are usable only within static topologies of devices. We propose a middleware architecture providing a constraint-based language guiding the deployment process at a high level and an autonomous agent-based system for establishing and maintaining a software deployment according to a deployment plan. Con...

  14. Tele-robotic/autonomous control using controlshell

    Energy Technology Data Exchange (ETDEWEB)

    Wilhelmsen, K.C.; Hurd, R.L.; Couture, S.

    1996-12-10

    A tele-robotic and autonomous controller architecture for waste handling and sorting has been developed which uses tele-robotics, autonomous grasping and image processing. As a starting point, prior work from LLNL and ORNL was restructured and ported to a special real-time development environment. Significant improvements in collision avoidance, force compliance, and shared control aspects were then developed. Several orders of magnitude improvement were made in some areas to meet the speed and robustness requirements of the application.

  15. Decentralized Coordination of Autonomous Vehicles at intersections

    OpenAIRE

    Makarem, Laleh; Gillet, Denis

    2011-01-01

    In this paper, the decentralized coordination of point-mass autonomous vehicles at intersections using navigation functions is considered. As main contribution, the inertia of the vehicles is taken into account to enable on-board energy optimization for crossing. In such a way, heavier vehicles that need more energy and time for acceleration or breaking are given an indirect priority at intersections. The proposed decentralized coordination scheme of autonomous vehicles at intersection is com...

  16. Omnidirectional Stereo Vision for Autonomous Vehicles

    OpenAIRE

    Schönbein, Miriam

    2014-01-01

    Environment perception with cameras is an important requirement for many applications for autonomous vehicles and robots. This work presents a stereoscopic omnidirectional camera system for autonomous vehicles which resolves the problem of a limited field of view and provides a 360° panoramic view of the environment. We present a new projection model for these cameras and show that the camera setup overcomes major drawbacks of traditional perspective cameras in many applications.

  17. Autonomous navigation and sign detector learning

    OpenAIRE

    Ellis, Liam; Pugeault, Nicolas; Öfjäll, Kristoffer; Hedborg, Johan; Bowden, Richard; Felsberg, Michael

    2013-01-01

    This paper presents an autonomous robotic system that incorporates novel Computer Vision, Machine Learning and Data Mining algorithms in order to learn to navigate and discover important visual entities. This is achieved within a Learning from Demonstration (LfD) framework, where policies are derived from example state-to-action mappings. For autonomous navigation, a mapping is learnt from holistic image features (GIST) onto control parameters using Random Forest regression. Additionally, vis...

  18. Autonomous Path Following Using Convolutional Networks

    OpenAIRE

    Schmiterlöw, Maria

    2012-01-01

    Autonomous vehicles have many application possibilities within many different fields like rescue missions, exploring foreign environments or unmanned vehicles etc. For such system to navigate in a safe manner, high requirements of reliability and security must be fulfilled. This master's thesis explores the possibility to use the machine learning algorithm convolutional network on a robotic platform for autonomous path following. The only input to predict the steering signal is a monochromati...

  19. Visual navigation for an autonomous mobile vehicle

    OpenAIRE

    Peterson, Kevin Robert

    1992-01-01

    Approved for public release; distribution is unlimited Image understanding for a mobile robotic vehicle is an important and complex task for ensuring safe navigation and extended autonomous operations. The goal of this work is to implement a working vision-based navigation control mechanism within a known environment onboard the autonomous mobile vehicle Yamabico-II. Although installing a working hardware system was not accomplished, the image processing, model description, pattern match...

  20. Control of the MARES Autonomous Underwater Vehicle

    OpenAIRE

    Bruno Ferreira; Miguel Pinto; Anibal Matos; Nuno Cruz

    2009-01-01

    This paper focuses the control problem of a nonholonomic autonomous underwater vehicle, moving in the tridimensional space. The dynamic of a body in submarine environments is strongly nonlinear. This implies that classical linear controllers are often inadequate whereby Lyapunov theory is here considered. Methods based in this theory are promising tools to design controllers and are applied to the case of MARES, a small-sized autonomous underwater vehicle. Several controllers based only on Ly...

  1. Autonomous vehicle development for vertical submarine observation

    OpenAIRE

    Gomáriz Castro, Spartacus; Prat Tasias, Jordi; Arbós, Alejandro; Viñolo Monzoncillo, Carlos; Pallares, Oriol

    2009-01-01

    This work proposes the development of an ocean observation vehicle. This vehicle, a hybrid between Autonomous Underwater Vehicles (AUV) and Autonomous Surface Vehicles (ASV) moves on the surface of the sea and makes vertical immersions to obtain the profiles of a water column according to a pre-established plan. Its design provides lower production cost and higher efficiency. GPS navigation allows the platform to move along the surface of the water while a radio-modem provid...

  2. Operations on Rigid Formations of Autonomous Agents

    OpenAIRE

    Eren, Tolga; Anderson, Brian D. O.; Morse, A. Stephen; Whiteley, Walter; Belhumeur, Peter N.

    2003-01-01

    This paper is concerned with the maintenance of rigid formations of mobile autonomous agents. A key element in all future multi-agent systems will be the role of sensor and communication networks as an integral part of coordination. Network topologies are critically important for autonomous systems involving mobile underwater, ground and air vehicles and for sensor networks. This paper focuses on developing techniques and strategies for the analysis and design of sensor a...

  3. TRIDENT: A Framework for Autonomous Underwater Intervention

    OpenAIRE

    Sanz Valero, Pedro José; Ridao, Pere; Oliver, Gabriel; Melchiorri, Claudio; Casalino, Giuseppe; Silvestre, Carlos; Petillot, Yvan; Turetta, Alessio

    2011-01-01

    TRIDENT is a STREP project recently approved by the European Commission whose proposal was submitted to the ICT call 4 of the 7th Framework Program. The project proposes a new methodology for multipurpose underwater intervention tasks. To that end, a cooperative team formed with an Autonomous Surface Craft and an Intervention Autonomous Underwater Vehicle will be used. The proposed methodology splits the mission in two stages mainly devoted to survey and intervention tasks, res...

  4. Advancing Autonomous Operations for Deep Space Vehicles

    Science.gov (United States)

    Haddock, Angie T.; Stetson, Howard K.

    2014-01-01

    Starting in Jan 2012, the Advanced Exploration Systems (AES) Autonomous Mission Operations (AMO) Project began to investigate the ability to create and execute "single button" crew initiated autonomous activities [1]. NASA Marshall Space Flight Center (MSFC) designed and built a fluid transfer hardware test-bed to use as a sub-system target for the investigations of intelligent procedures that would command and control a fluid transfer test-bed, would perform self-monitoring during fluid transfers, detect anomalies and faults, isolate the fault and recover the procedures function that was being executed, all without operator intervention. In addition to the development of intelligent procedures, the team is also exploring various methods for autonomous activity execution where a planned timeline of activities are executed autonomously and also the initial analysis of crew procedure development. This paper will detail the development of intelligent procedures for the NASA MSFC Autonomous Fluid Transfer System (AFTS) as well as the autonomous plan execution capabilities being investigated. Manned deep space missions, with extreme communication delays with Earth based assets, presents significant challenges for what the on-board procedure content will encompass as well as the planned execution of the procedures.

  5. Autonomous control systems - Architecture and fundamental issues

    Science.gov (United States)

    Antsaklis, P. J.; Passino, K. M.; Wang, S. J.

    1988-01-01

    A hierarchical functional autonomous controller architecture is introduced. In particular, the architecture for the control of future space vehicles is described in detail; it is designed to ensure the autonomous operation of the control system and it allows interaction with the pilot and crew/ground station, and the systems on board the autonomous vehicle. The fundamental issues in autonomous control system modeling and analysis are discussed. It is proposed to utilize a hybrid approach to modeling and analysis of autonomous systems. This will incorporate conventional control methods based on differential equations and techniques for the analysis of systems described with a symbolic formalism. In this way, the theory of conventional control can be fully utilized. It is stressed that autonomy is the design requirement and intelligent control methods appear at present, to offer some of the necessary tools to achieve autonomy. A conventional approach may evolve and replace some or all of the `intelligent' functions. It is shown that in addition to conventional controllers, the autonomous control system incorporates planning, learning, and FDI (fault detection and identification).

  6. Dynamics Control Approaches to Improve Vibratory Environment of the Helicopter Aircrew

    Science.gov (United States)

    Wickramasinghe, Viresh Kanchana

    Although helicopter has become a versatile mode of aerial transportation, high vibration levels leads to poor ride quality for its passengers and aircrew. Undesired vibration transmitted through the helicopter seats have been known to cause fatigue and discomfort to the aircrew in the short-term as well as neck strain and back pain injuries due to long-term exposure. This research study investigated the use of novel active as well as passive methodologies integrated in helicopter seats to mitigate the aircrew exposure to high vibration levels. Due to significantly less certification effort required to modify the helicopter seat structure, application of novel technologies to the seat is more practical compared to flight critical components such as the main rotor to reduce aircrew vibration. In particular, this research effort developed a novel adaptive seat mount approach based on active vibration control technology. This novel design that incorporated two stacked piezoelectric actuators as active struts increases the bending stiffness to avoid the low frequency resonance while generating forces to counteract higher harmonic vibration peaks. A real-time controller implemented using a feed-forward algorithm based on adaptive notches counteracted the forced vibration peaks while a robust feedback control algorithm suppressed the resonance modes. The effectiveness of the adaptive seat mount system was demonstrated through extensive closed-loop control tests on a full-scale helicopter seat using representative helicopter floor vibration profiles. Test results concluded that the proposed adaptive seat mount approach based on active control technology is a viable solution for the helicopter seat vibration control application. In addition, a unique flight test using a Bell-412 helicopter demonstrated that the aircrew is exposed to high levels of vibration during flight and that the whole body vibration spectrum varied substantially depending on operating conditions as

  7. A review of Army Air Corps helicopter accidents, 1971-1982.

    Science.gov (United States)

    Vyrnwy-Jones, P

    1985-05-01

    A comprehensive review of helicopter accident data from ACC sources is presented for the period 1971-1982. Accident and fatality rates have declined from the high values quoted in earlier studies in the 1960's and are now similar to those of fixed wing aircraft equipped with ejection seats. This improvement is related to the replacement of older reciprocating engined helicopters by turbine powered units and parallel progress in helicopter design, aircraft servicing, and pilot training. AAC accident rates now compare extremely favourably with information from civilian sources, though fatality rates are similar. Pilot error remains the main cause of accidents (75%). Particular attention is paid to subsidiary aetiologies such as tail rotor strikes, disorientation, and ground accidents. Helicopter accidents involving fatalities on Operation Corporate are mentioned briefly. Methods whereby occupant protection and aircraft crashworthiness can be improved are covered and it is concluded that assisted escape, although an ideal solution, is by no means an urgent requirement for helicopters, in view of the dramatic reduction in accident and fatality rates. PMID:4004673

  8. The Effects of Ambient Conditions on Helicopter Harmonic Noise Radiation: Theory and Experiment

    Science.gov (United States)

    Greenwood, Eric; Sim, Ben W.; Boyd, D. Douglas, Jr.

    2016-01-01

    The effects of ambient atmospheric conditions, air temperature and density, on rotor harmonic noise radiation are characterized using theoretical models and experimental measurements of helicopter noise collected at three different test sites at elevations ranging from sea level to 7000 ft above sea level. Significant changes in the thickness, loading, and blade-vortex interaction noise levels and radiation directions are observed across the different test sites for an AS350 helicopter flying at the same indicated airspeed and gross weight. However, the radiated noise is shown to scale with ambient pressure when the flight condition of the helicopter is defined in nondimensional terms. Although the effective tip Mach number is identified as the primary governing parameter for thickness noise, the nondimensional weight coefficient also impacts lower harmonic loading noise levels, which contribute strongly to low frequency harmonic noise radiation both in and out of the plane of the horizon. Strategies for maintaining the same nondimensional rotor operating condition under different ambient conditions are developed using an analytical model of single main rotor helicopter trim and confirmed using a CAMRAD II model of the AS350 helicopter. The ability of the Fundamental Rotorcraft Acoustics Modeling from Experiments (FRAME) technique to generalize noise measurements made under one set of ambient conditions to make accurate noise predictions under other ambient conditions is also validated.

  9. Correlate Life Predictions and Condition Indicators in Helicopter Tail Gearbox Bearings

    Science.gov (United States)

    Dempsey, Paula J.; Bolander, Nathan; Haynes, Chris; Branning, Jeremy; Wade, Daniel R.

    2010-01-01

    Research to correlate bearing remaining useful life (RUL) predictions with Helicopter Health Usage Monitoring Systems (HUMS) condition indicators (CI) to indicate the damage state of a transmission component has been developed. Condition indicators were monitored and recorded on UH-60M (Black Hawk) tail gearbox output shaft thrust bearings, which had been removed from helicopters and installed in a bearing spall propagation test rig. Condition indicators monitoring the tail gearbox output shaft thrust bearings in UH-60M helicopters were also recorded from an on-board HUMS. The spal-lpropagation data collected in the test rig was used to generate condition indicators for bearing fault detection. A damage progression model was also developed from this data. Determining the RUL of this component in a helicopter requires the CI response to be mapped to the damage state. The data from helicopters and a test rig were analyzed to determine if bearing remaining useful life predictions could be correlated with HUMS condition indicators (CI). Results indicate data fusion analysis techniques can be used to map the CI response to the damage levels.

  10. Hypertensive intracerebral hemorrhage in isolated islands in Nagasaki prefecture. A remote teleradiology and helicopter transportation system

    International Nuclear Information System (INIS)

    Hypertensive intracerebral hemorrhage (HICH) causes significant morbidity and mortality. The time required to transport the patients to a specialized hospital can influence the prognosis. In the isolated islands in Nagasaki prefecture, there is no medical institution which can offer emergent neurosurgical intervention. We reviewed the cases of HICH in this region from January 2006 to September 2010, who were transferred to Nagasaki Medical Center by a helicopter after consultation via teleradiology. Eighty four cases (23%) were transferred via helicopter to our institution from isolated islands. In three of them (4%), re-hemorrhage was demonstrated on computed tomography after helicopter transportation, and one of three had been administered an anti-coagulant agent. Only one case (1%) has deteriorated during helicopter transportation because of acute obstructive hydrocephalus. The outcome at discharge was as follows: modified Rankin Scale (mRS) I: 3 cases (4%), II: 5 cases (6%), III: 3 cases (4%), IV: 30 cases (36%), V: 31 cases (37%), VI: 12 cases (14%), 43 cases (51%) showed poor outcome (mRS V, VI). For medical management in isolated islands, a remote teleradiology system is indispensable to decide a strategy of treatment rapidly, and a helicopter transportation system is very useful in cases requiring emergent neurosurgical intervention, particular in cases of impending cerebral herniation or acute hydrocephalus. However, we may need to expand logistical supporting hospitals or secure other transportation facilities because many of the patients with poor outcome can not return to their home islands. (author)

  11. Final assessment of vibro-acoustic source strength descriptors of helicopter gearboxes

    DEFF Research Database (Denmark)

    Ohlrich, Mogens; Rasmussen, Ulrik Møller

    1996-01-01

    Two novel measurement techniques have been developed for quantifying the vibro-aqcoustic source strength of lightweight helicopter gearboxes. The accuracy, robustness and implementation of these methods have been examined by a comprehensive investigation, including theoretical studies of simple m...... results of this work are essential as input for any prediction code of the internal noise in a helicopter cabin, because the prediction requires knowledge of the major sources, that is, the rotors, engines and gearboxes.......Two novel measurement techniques have been developed for quantifying the vibro-aqcoustic source strength of lightweight helicopter gearboxes. The accuracy, robustness and implementation of these methods have been examined by a comprehensive investigation, including theoretical studies of simple...... multi-modal beam systems and extensive experiments with more realistic small scale models and with large, detailed 3/4-scale test structures of a medium-size helicopter. In addition, partial verification tests have been conducted with the Eurocopter BK 117 helicopter and its main rotor gearbox. The...

  12. 76 FR 68301 - Airworthiness Directives; Bell Helicopter Textron, Inc. (Bell), Model 205A-1, 205B, 210, and 212...

    Science.gov (United States)

    2011-11-04

    ... same type designs, this AD supersedes AD 2010-03-03 (75 FR 5681, February 4, 2010), retaining the same... airworthiness directive (AD) for Bell Model 205B and 212 helicopters with certain main rotor blade (blade... of the helicopter. Since issuing AD 2010-03-03 (75 FR 5681, February 4, 2010), we have...

  13. 75 FR 79312 - Special Conditions: Eurocopter France (ECF) Model EC225LP Helicopter, Installation of a Search...

    Science.gov (United States)

    2010-12-20

    .... Special conditions No. 29-022-SC, published in the Federal Register on November 6, 2008 (73 FR 65968... operations conducted over water in offshore areas clear of obstructions. The SAR modes enable the helicopter... model EC225LP helicopters was published in the Federal Register on November 6, 2008 (73 FR 65968),...

  14. Black Hawk Down?: Establishing Helicopter Parenting as a Distinct Construct from Other Forms of Parental Control during Emerging Adulthood

    Science.gov (United States)

    Padilla-Walker, Laura M.; Nelson, Larry J.

    2012-01-01

    The purpose of the current study was to establish a measure of helicopter parenting that was distinct from other forms of parental control, and to examine parental and behavioral correlates of helicopter parenting. Participants included 438 undergraduate students from four universities in the United States (M[subscript age] = 19.65, SD = 2.00,…

  15. Design and Evaluation of a Low-Noise Helicopter Blade

    Science.gov (United States)

    Kondo, Natsuki; Tsujiuchi, Tomoka; Murashige, Atsushi; Nishimura, Hiroki; Aoki, Makoto; Tsuchihashi, Akihiko; Yamakawa, Eiichi; Aoyama, Takashi; Saito, Shigeru

    A low-noise helicopter blade, AT1, was designed with the concept of reducing noise without the drop of rotor performance. In the concept, High-Speed Impulsive (HSI) noise is reduced by applying a thin airfoil in the tip region and a dog-tooth like extension in the leading-edge of the tip region. Blade-Vortex Interaction (BVI) noise is reduced by applying the extension and a strong taper near the tip end. The stall angle of the blade is increased by the effect of the vortex generated from the leading-edge extension. As a result, the drop of rotor performance caused by the thin airfoil and the reduction of rotor rotational speed is recovered. The low-noise characteristics and the performance of AT1 were evaluated by a model rotor test conducted at Deutsch Niederländischer Windkanal (DNW). It is shown that AT1 reduces HSI noise and BVI noise and has good performance in forward flight conditions. However, the improvement of performance in high-lift conditions still remains as a future problem.

  16. Sound Directivity Generated by Helicopter Rotors Using Wave Tracing Concepts

    Science.gov (United States)

    Leishman, J. G.

    1999-04-01

    Results are presented from a study of directivity and sound focusing effects generated by helicopter rotors encountering parallel and oblique blade vortex interactions (BVI). The primary analysis is performed by using wave tracing to determine ray cones and acoustic lines from source points on the rotor with supersonic trace (phase) velocities. The results are compared and contrasted to predictions made from a numerical solution of the Ffowcs-Williams Hawkins equation. Sample problems considered include parallel and oblique BVI with an isolated line vortex, and interactions with self-generated epicycloidal vortices in forward flight. It is confirmed that the BVI process can produce strong directivity and clusters of focused sound waves in the far field. The trace velocity and wave tracing technique is shown to have potential applications for studies in noise reduction and/or noise directivity modifications using passive devices such as blade tip sweep. It is also shown that the numerically efficient nature of determining the primary acoustic lines with the trace velocity method can allow regions with strong directivity to be efficiently mapped out using redistributive observer point techniques.

  17. Flow Structures within a Helicopter Rotor Hub Wake

    Science.gov (United States)

    Elbing, Brian; Reich, David; Schmitz, Sven

    2015-11-01

    A scaled model of a notional helicopter rotor hub was tested in the 48'' Garfield Thomas Water Tunnel at the Applied Research Laboratory Penn State. The measurement suite included total hub drag and wake velocity measurements (LDV, PIV, stereo-PIV) at three downstream locations. The main objective was to understand the spatiotemporal evolution of the unsteady wake between the rotor hub and the nominal location of the empennage (tail). Initial analysis of the data revealed prominent two- and four-per-revolution fluid structures linked to geometric hub features persisting into the wake far-field. In addition, a six-per-revolution fluid structure was observed in the far-field, which is unexpected due to the lack of any hub feature with the corresponding symmetry. This suggests a nonlinear interaction is occurring within the wake to generate these structures. This presentation will provide an overview of the experimental data and analysis with particular emphasis on these six-per-revolution structures.

  18. Experimental Investigation of a Helicopter Rotor Hub Wake

    Science.gov (United States)

    Reich, David; Elbing, Brian; Schmitz, Sven

    2013-11-01

    A scaled model of a notional helicopter rotor hub was tested in the 48'' Garfield Thomas Water Tunnel at the Applied Research Laboratory Penn State. The main objectives of the experiment were to understand the spatial- and temporal content of the unsteady wake downstream of a rotor hub up to a distance corresponding to the empennage. Primary measurements were the total hub drag and velocity measurements at three nominal downstream locations. Various flow structures were identified and linked to geometric features of the hub model. The most prominent structures were two-per-revolution (hub component: scissors) and four-per-revolution (hub component: main hub arms) vortices shed by the hub. Both the two-per-revolution and four-per-revolution structures persisted far downstream of the hub, but the rate of dissipation was greater for the four-per-rev structures. This work provides a dataset for enhanced understanding of the fundamental physics underlying rotor hub flows and serves as validation data for future CFD analyses.

  19. Minimum weight design of helicopter rotor blades with frequency constraints

    Science.gov (United States)

    Chattopadhyay, Aditi; Walsh, Joanne L.

    1989-01-01

    The minimum weight design of helicopter rotor blades subject to constraints on fundamental coupled flap-lag natural frequencies has been studied in this paper. A constraint has also been imposed on the minimum value of the blade autorotational inertia to ensure that the blade has sufficient inertia to autorotate in case of an engine failure. The program CAMRAD has been used for the blade modal analysis and the program CONMIN has been used for the optimization. In addition, a linear approximation analysis involving Taylor series expansion has been used to reduce the analysis effort. The procedure contains a sensitivity analysis which consists of analytical derivatives of the objective function and the autorotational inertia constraint and central finite difference derivatives of the frequency constraints. Optimum designs have been obtained for blades in vacuum with both rectangular and tapered box beam structures. Design variables include taper ratio, nonstructural segment weights and box beam dimensions. The paper shows that even when starting with an acceptable baseline design, a significant amount of weight reduction is possible while satisfying all the constraints for blades with rectangular and tapered box beams.

  20. Training Presentation for NASA Civil Helicopter Safety Website

    Science.gov (United States)

    Iseler, Laura

    2002-01-01

    NASA civil helicopter safety News & Updates include the following: Mar. 2002. The Air Medical Operations Survey has been completed! Check it out! Also accessible via the Mission pages under Air Medical Mission. Air Medical and Law Enforcement Mission pages have been added. They are accessible via the Mission pages. The Public Use, Personal, Offshore, Law Enforcement, External Load, Business and Gyro accident pages (accessable via the Mission page) have been updated. Feb. 2002. A Words of Wisdom section has been added. You can access it by clicking the Library button. A link to a Corporate Accident Response Plan has been added to the Accident page. The AMs, Aerial Application and Instruction accident pages (accessable via the Mission page) have been updated. Jan. 2002. A new searchable safety article database has been added. You can access it by clicking the Library button. The 2001 accident summaries have been updated and the statistics have been compiled - check it out by clicking the accident tab to the left. Dec. 2001. Please read the FAA Administrator's memo regarding the latest FBI warning. 3ee the FAA column - Fall 2001 Read it now!