Neuro-fuzzy controller to navigate an unmanned vehicle.

Science.gov (United States)

Selma, Boumediene; Chouraqui, Samira

2013-12-01

A Neuro-fuzzy control method for an Unmanned Vehicle (UV) simulation is described. The objective is guiding an autonomous vehicle to a desired destination along a desired path in an environment characterized by a terrain and a set of distinct objects, such as obstacles like donkey traffic lights and cars circulating in the trajectory. The autonomous navigate ability and road following precision are mainly influenced by its control strategy and real-time control performance. Fuzzy Logic Controller can very well describe the desired system behavior with simple "if-then" relations owing the designer to derive "if-then" rules manually by trial and error. On the other hand, Neural Networks perform function approximation of a system but cannot interpret the solution obtained neither check if its solution is plausible. The two approaches are complementary. Combining them, Neural Networks will allow learning capability while Fuzzy-Logic will bring knowledge representation (Neuro-Fuzzy). In this paper, an artificial neural network fuzzy inference system (ANFIS) controller is described and implemented to navigate the autonomous vehicle. Results show several improvements in the control system adjusted by neuro-fuzzy techniques in comparison to the previous methods like Artificial Neural Network (ANN).

Fiber optic gyroscopes for vehicle navigation systems

Science.gov (United States)

Kumagai, Tatsuya; Soekawa, Hirokazu; Yuhara, Toshiya; Kajioka, Hiroshi; Oho, Shigeru; Sonobe, Hisao

1994-03-01

Fiber optic gyroscopes (FOGs) have been developed for vehicle navigation systems and are used in Toyota Motor Corporation models Mark II, Chaser and Cresta in Japan. Use of FOGs in these systems requires high reliability under a wide range of conditions, especially in a temperature range between -40 and 85 degree(s)C. In addition, a high cost-performance ratio is needed. We have developed optical and electrical systems that are inexpensive and can perform well. They are ready to be mass-produced. FOGs have already been installed in luxury automobiles, and will soon be included in more basic vehicles. We have developed more inexpensive FOGs for this purpose.

Vehicle health management for guidance, navigation and control systems

Science.gov (United States)

Radke, Kathleen; Frazzini, Ron; Bursch, Paul; Wald, Jerry; Brown, Don

1993-01-01

The objective of the program was to architect a vehicle health management (VHM) system for space systems avionics that assures system readiness for launch vehicles and for space-based dormant vehicles. The platforms which were studied and considered for application of VHM for guidance, navigation and control (GN&C) included the Advanced Manned Launch System (AMLS), the Horizontal Landing-20/Personnel Launch System (HL-20/PLS), the Assured Crew Return Vehicle (ACRV) and the Extended Duration Orbiter (EDO). This set was selected because dormancy and/or availability requirements are driving the designs of these future systems.

Navigation of the autonomous vehicle reverse movement

Science.gov (United States)

Rachkov, M.; Petukhov, S.

2018-02-01

The paper presents a mathematical formulation of the vehicle reverse motion along a multi-link polygonal trajectory consisting of rectilinear segments interconnected by nodal points. Relevance of the problem is caused by the need to solve a number of tasks: to save the vehicle in the event of а communication break by returning along the trajectory already passed, to avoid a turn on the ground in constrained obstacles or dangerous conditions, or a partial return stroke for the subsequent bypass of the obstacle and continuation of the forward movement. The method of navigation with direct movement assumes that the reverse path is elaborated by using landmarks. To measure landmarks on board, a block of cameras is placed on a vehicle controlled by the operator through the radio channel. Errors in estimating deviation from the nominal trajectory of motion are determined using the multidimensional correlation analysis apparatus based on the dynamics of a lateral deviation error and a vehicle speed error. The result of the experiment showed a relatively high accuracy in determining the state vector that provides the vehicle reverse motion relative to the reference trajectory with a practically acceptable error while returning to the start point.

Autonomous Navigation for Autonomous Underwater Vehicles Based on Information Filters and Active Sensing

Directory of Open Access Journals (Sweden)

Tianhong Yan

2011-11-01

Full Text Available This paper addresses an autonomous navigation method for the autonomous underwater vehicle (AUV C-Ranger applying information-filter-based simultaneous localization and mapping (SLAM, and its sea trial experiments in Tuandao Bay (Shangdong Province, P.R. China. Weak links in the information matrix in an extended information filter (EIF can be pruned to achieve an efficient approach-sparse EIF algorithm (SEIF-SLAM. All the basic update formulae can be implemented in constant time irrespective of the size of the map; hence the computational complexity is significantly reduced. The mechanical scanning imaging sonar is chosen as the active sensing device for the underwater vehicle, and a compensation method based on feedback of the AUV pose is presented to overcome distortion of the acoustic images due to the vehicle motion. In order to verify the feasibility of the navigation methods proposed for the C-Ranger, a sea trial was conducted in Tuandao Bay. Experimental results and analysis show that the proposed navigation approach based on SEIF-SLAM improves the accuracy of the navigation compared with conventional method; moreover the algorithm has a low computational cost when compared with EKF-SLAM.

Autonomous navigation for autonomous underwater vehicles based on information filters and active sensing.

Science.gov (United States)

He, Bo; Zhang, Hongjin; Li, Chao; Zhang, Shujing; Liang, Yan; Yan, Tianhong

2011-01-01

This paper addresses an autonomous navigation method for the autonomous underwater vehicle (AUV) C-Ranger applying information-filter-based simultaneous localization and mapping (SLAM), and its sea trial experiments in Tuandao Bay (Shangdong Province, P.R. China). Weak links in the information matrix in an extended information filter (EIF) can be pruned to achieve an efficient approach-sparse EIF algorithm (SEIF-SLAM). All the basic update formulae can be implemented in constant time irrespective of the size of the map; hence the computational complexity is significantly reduced. The mechanical scanning imaging sonar is chosen as the active sensing device for the underwater vehicle, and a compensation method based on feedback of the AUV pose is presented to overcome distortion of the acoustic images due to the vehicle motion. In order to verify the feasibility of the navigation methods proposed for the C-Ranger, a sea trial was conducted in Tuandao Bay. Experimental results and analysis show that the proposed navigation approach based on SEIF-SLAM improves the accuracy of the navigation compared with conventional method; moreover the algorithm has a low computational cost when compared with EKF-SLAM.

Navigation simulator for the Space Tug vehicle

Science.gov (United States)

Colburn, B. K.; Boland, J. S., III; Peters, E. G.

1977-01-01

A general simulation program (GSP) for state estimation of a nonlinear space vehicle flight navigation system is developed and used as a basis for evaluating the performance of a Space Tug navigation system. An explanation of the iterative guidance mode (IGM) guidance law, derivation of the dynamics, coordinate frames and state estimation routines are given in order to clarify the assumptions and approximations made. A number of simulation and analytical studies are used to demonstrate the operation of the Tug system. Included in the simulation studies are (1) initial offset vector parameter study; (2) propagation time vs accuracy; (3) measurement noise parametric study and (4) reduction in computational burden of an on-board implementable scheme. From the results of these studies, conclusions and recommendations concerning future areas of practical and theoretical work are presented.

Autonomous Navigation Apparatus With Neural Network for a Mobile Vehicle

Science.gov (United States)

Quraishi, Naveed (Inventor)

1996-01-01

An autonomous navigation system for a mobile vehicle arranged to move within an environment includes a plurality of sensors arranged on the vehicle and at least one neural network including an input layer coupled to the sensors, a hidden layer coupled to the input layer, and an output layer coupled to the hidden layer. The neural network produces output signals representing respective positions of the vehicle, such as the X coordinate, the Y coordinate, and the angular orientation of the vehicle. A plurality of patch locations within the environment are used to train the neural networks to produce the correct outputs in response to the distances sensed.

Feature and Pose Constrained Visual Aided Inertial Navigation for Computationally Constrained Aerial Vehicles

Science.gov (United States)

Williams, Brian; Hudson, Nicolas; Tweddle, Brent; Brockers, Roland; Matthies, Larry

2011-01-01

A Feature and Pose Constrained Extended Kalman Filter (FPC-EKF) is developed for highly dynamic computationally constrained micro aerial vehicles. Vehicle localization is achieved using only a low performance inertial measurement unit and a single camera. The FPC-EKF framework augments the vehicle's state with both previous vehicle poses and critical environmental features, including vertical edges. This filter framework efficiently incorporates measurements from hundreds of opportunistic visual features to constrain the motion estimate, while allowing navigating and sustained tracking with respect to a few persistent features. In addition, vertical features in the environment are opportunistically used to provide global attitude references. Accurate pose estimation is demonstrated on a sequence including fast traversing, where visual features enter and exit the field-of-view quickly, as well as hover and ingress maneuvers where drift free navigation is achieved with respect to the environment.

Navigation of autonomous vehicles for oil spill cleaning in dynamic and uncertain environments

Science.gov (United States)

Jin, Xin; Ray, Asok

2014-04-01

In the context of oil spill cleaning by autonomous vehicles in dynamic and uncertain environments, this paper presents a multi-resolution algorithm that seamlessly integrates the concepts of local navigation and global navigation based on the sensory information; the objective here is to enable adaptive decision making and online replanning of vehicle paths. The proposed algorithm provides a complete coverage of the search area for clean-up of the oil spills and does not suffer from the problem of having local minima, which is commonly encountered in potential-field-based methods. The efficacy of the algorithm is tested on a high-fidelity player/stage simulator for oil spill cleaning in a harbour, where the underlying oil weathering process is modelled as 2D random-walk particle tracking. A preliminary version of this paper was presented by X. Jin and A. Ray as 'Coverage Control of Autonomous Vehicles for Oil Spill Cleaning in Dynamic and Uncertain Environments', Proceedings of the American Control Conference, Washington, DC, June 2013, pp. 2600-2605.

GPS navigation algorithms for Autonomous Airborne Refueling of Unmanned Air Vehicles

Science.gov (United States)

Khanafseh, Samer Mahmoud

Unmanned Air Vehicles (UAVs) have recently generated great interest because of their potential to perform hazardous missions without risking loss of life. If autonomous airborne refueling is possible for UAVs, mission range and endurance will be greatly enhanced. However, concerns about UAV-tanker proximity, dynamic mobility and safety demand that the relative navigation system meets stringent requirements on accuracy, integrity, and continuity. In response, this research focuses on developing high-performance GPS-based navigation architectures for Autonomous Airborne Refueling (AAR) of UAVs. The AAR mission is unique because of the potentially severe sky blockage introduced by the tanker. To address this issue, a high-fidelity dynamic sky blockage model was developed and experimentally validated. In addition, robust carrier phase differential GPS navigation algorithms were derived, including a new method for high-integrity reacquisition of carrier cycle ambiguities for recently-blocked satellites. In order to evaluate navigation performance, world-wide global availability and sensitivity covariance analyses were conducted. The new navigation algorithms were shown to be sufficient for turn-free scenarios, but improvement in performance was necessary to meet the difficult requirements for a general refueling mission with banked turns. Therefore, several innovative methods were pursued to enhance navigation performance. First, a new theoretical approach was developed to quantify the position-domain integrity risk in cycle ambiguity resolution problems. A mechanism to implement this method with partially-fixed cycle ambiguity vectors was derived, and it was used to define tight upper bounds on AAR navigation integrity risk. A second method, where a new algorithm for optimal fusion of measurements from multiple antennas was developed, was used to improve satellite coverage in poor visibility environments such as in AAR. Finally, methods for using data-link extracted

Improved Line Tracking System for Autonomous Navigation of High-Speed Vehicle

Directory of Open Access Journals (Sweden)

Yahya Zare Khafri

2012-07-01

Full Text Available Line tracking navigation is one of the most widely techniques used in the robot navigation. In this paper, a customized line tracking system is proposed for autonomous navigation of high speed vehicles. In the presented system, auxiliary information -in addition to the road path- is added to the tracking lines such as locations of turn and intersections in the real roads. Moreover, the geometric position of line sensors is re-designed enables the high rate sensing with higher reliability. Finally, a light-weight navigation algorithm is proposed allow the high-speed movement using a reasonable processing power. This system is implemented on a MIPS-based embedded processor and experimental results with this embedded system show more than 98% accuracy at 200km/h with a 1GHz processor is viable.

Intelligence Level Performance Standards Research for Autonomous Vehicles.

Science.gov (United States)

Bostelman, Roger B; Hong, Tsai H; Messina, Elena

2015-01-01

United States and European safety standards have evolved to protect workers near Automatic Guided Vehicles (AGV's). However, performance standards for AGV's and mobile robots have only recently begun development. Lessons can be learned from research and standards efforts for mobile robots applied to emergency response and military applications. Research challenges, tests and evaluations, and programs to develop higher intelligence levels for vehicles can also used to guide industrial AGV developments towards more adaptable and intelligent systems. These other efforts also provide useful standards development criteria for AGV performance test methods. Current standards areas being considered for AGVs are for docking, navigation, obstacle avoidance, and the ground truth systems that measure performance. This paper provides a look to the future with standards developments in both the performance of vehicles and the dynamic perception systems that measure intelligent vehicle performance.

A Feedforward Control Approach to the Local Navigation Problem for Autonomous Vehicles

Science.gov (United States)

1994-05-02

AD-A282 787 " A Feedforward Control Approach to the Local Navigation Problem for Autonomous Vehicles Alonzo Kelly CMU-RI-TR-94-17 The Robotics...follow, or a direction to prefer, it cannot generate its own strategic goals. Therefore, it solves the local planning problem for autonomous vehicles . The... autonomous vehicles . It is intelligent because it uses range images that are generated from either a laser rangefinder or a stereo triangulation

Vibrotactile in-vehicle navigation system

NARCIS (Netherlands)

Erp, J.B.F. van; Veen, H.J. van

2004-01-01

A vibrotactile display, consisting ofeight vibrating elements or tactors mounted in a driver's seat, was tested in a driving simulator. Participants drove with visual, tactile and multimodal navigation displays through a built-up area. Workload and the reaction time to navigation messages were

Polar Cooperative Navigation Algorithm for Multi-Unmanned Underwater Vehicles Considering Communication Delays

Directory of Open Access Journals (Sweden)

Zheping Yan

2018-03-01

Full Text Available To solve the navigation accuracy problems of multi-Unmanned Underwater Vehicles (multi-UUVs in the polar region, a polar cooperative navigation algorithm for multi-UUVs considering communication delays is proposed in this paper. UUVs are important pieces of equipment in ocean engineering for marine development. For UUVs to complete missions, precise navigation is necessary. It is difficult for UUVs to establish true headings because of the rapid convergence of Earth meridians and the severe polar environment. Based on the polar grid navigation algorithm, UUV navigation in the polar region can be accomplished with the Strapdown Inertial Navigation System (SINS in the grid frame. To save costs, a leader-follower type of system is introduced in this paper. The leader UUV helps the follower UUVs to achieve high navigation accuracy. Follower UUVs correct their own states based on the information sent by the leader UUV and the relative position measured by ultra-short baseline (USBL acoustic positioning. The underwater acoustic communication delay is quantized by the model. In this paper, considering underwater acoustic communication delay, the conventional adaptive Kalman filter (AKF is modified to adapt to polar cooperative navigation. The results demonstrate that the polar cooperative navigation algorithm for multi-UUVs that considers communication delays can effectively navigate the sailing of multi-UUVs in the polar region.

Vehicle navigation in populated areas using predictive control with environmental uncertainty handling

Directory of Open Access Journals (Sweden)

Skrzypczyk Krzysztof

2017-06-01

Full Text Available This paper addresses the problem of navigating an autonomous vehicle using environmental dynamics prediction. The usefulness of the Game Against Nature formalism adapted to modelling environmental prediction uncertainty is discussed. The possibility of the control law synthesis on the basis of strategies against Nature is presented. The properties and effectiveness of the approach presented are verified by simulations carried out in MATLAB.

Intelligence algorithms for autonomous navigation in a ground vehicle

Science.gov (United States)

Petkovsek, Steve; Shakya, Rahul; Shin, Young Ho; Gautam, Prasanna; Norton, Adam; Ahlgren, David J.

2012-01-01

This paper will discuss the approach to autonomous navigation used by "Q," an unmanned ground vehicle designed by the Trinity College Robot Study Team to participate in the Intelligent Ground Vehicle Competition (IGVC). For the 2011 competition, Q's intelligence was upgraded in several different areas, resulting in a more robust decision-making process and a more reliable system. In 2010-2011, the software of Q was modified to operate in a modular parallel manner, with all subtasks (including motor control, data acquisition from sensors, image processing, and intelligence) running simultaneously in separate software processes using the National Instruments (NI) LabVIEW programming language. This eliminated processor bottlenecks and increased flexibility in the software architecture. Though overall throughput was increased, the long runtime of the image processing process (150 ms) reduced the precision of Q's realtime decisions. Q had slow reaction times to obstacles detected only by its cameras, such as white lines, and was limited to slow speeds on the course. To address this issue, the image processing software was simplified and also pipelined to increase the image processing throughput and minimize the robot's reaction times. The vision software was also modified to detect differences in the texture of the ground, so that specific surfaces (such as ramps and sand pits) could be identified. While previous iterations of Q failed to detect white lines that were not on a grassy surface, this new software allowed Q to dynamically alter its image processing state so that appropriate thresholds could be applied to detect white lines in changing conditions. In order to maintain an acceptable target heading, a path history algorithm was used to deal with local obstacle fields and GPS waypoints were added to provide a global target heading. These modifications resulted in Q placing 5th in the autonomous challenge and 4th in the navigation challenge at IGVC.

SINS/CNS Nonlinear Integrated Navigation Algorithm for Hypersonic Vehicle

Directory of Open Access Journals (Sweden)

Yong-jun Yu

2015-01-01

Full Text Available Celestial Navigation System (CNS has characteristics of accurate orientation and strong autonomy and has been widely used in Hypersonic Vehicle. Since the CNS location and orientation mainly depend upon the inertial reference that contains errors caused by gyro drifts and other error factors, traditional Strap-down Inertial Navigation System (SINS/CNS positioning algorithm setting the position error between SINS and CNS as measurement is not effective. The model of altitude azimuth, platform error angles, and horizontal position is designed, and the SINS/CNS tightly integrated algorithm is designed, in which CNS altitude azimuth is set as measurement information. GPF (Gaussian particle filter is introduced to solve the problem of nonlinear filtering. The results of simulation show that the precision of SINS/CNS algorithm which reaches 130 m using three stars is improved effectively.

FlyAR: augmented reality supported micro aerial vehicle navigation.

Science.gov (United States)

Zollmann, Stefanie; Hoppe, Christof; Langlotz, Tobias; Reitmayr, Gerhard

2014-04-01

Micro aerial vehicles equipped with high-resolution cameras can be used to create aerial reconstructions of an area of interest. In that context automatic flight path planning and autonomous flying is often applied but so far cannot fully replace the human in the loop, supervising the flight on-site to assure that there are no collisions with obstacles. Unfortunately, this workflow yields several issues, such as the need to mentally transfer the aerial vehicle’s position between 2D map positions and the physical environment, and the complicated depth perception of objects flying in the distance. Augmented Reality can address these issues by bringing the flight planning process on-site and visualizing the spatial relationship between the planned or current positions of the vehicle and the physical environment. In this paper, we present Augmented Reality supported navigation and flight planning of micro aerial vehicles by augmenting the user’s view with relevant information for flight planning and live feedback for flight supervision. Furthermore, we introduce additional depth hints supporting the user in understanding the spatial relationship of virtual waypoints in the physical world and investigate the effect of these visualization techniques on the spatial understanding.

Geomagnetic Navigation of Autonomous Underwater Vehicle Based on Multi-objective Evolutionary Algorithm.

Science.gov (United States)

Li, Hong; Liu, Mingyong; Zhang, Feihu

2017-01-01

This paper presents a multi-objective evolutionary algorithm of bio-inspired geomagnetic navigation for Autonomous Underwater Vehicle (AUV). Inspired by the biological navigation behavior, the solution was proposed without using a priori information, simply by magnetotaxis searching. However, the existence of the geomagnetic anomalies has significant influence on the geomagnetic navigation system, which often disrupts the distribution of the geomagnetic field. An extreme value region may easily appear in abnormal regions, which makes AUV lost in the navigation phase. This paper proposes an improved bio-inspired algorithm with behavior constraints, for sake of making AUV escape from the abnormal region. First, the navigation problem is considered as the optimization problem. Second, the environmental monitoring operator is introduced, to determine whether the algorithm falls into the geomagnetic anomaly region. Then, the behavior constraint operator is employed to get out of the abnormal region. Finally, the termination condition is triggered. Compared to the state-of- the-art, the proposed approach effectively overcomes the disturbance of the geomagnetic abnormal. The simulation result demonstrates the reliability and feasibility of the proposed approach in complex environments.

Demonstration of a Moving-Map System for Improved Lane Navigation of Amphibious Vehicles

National Research Council Canada - National Science Library

Clohrenz, Maura

2003-01-01

The Naval Research Laboratory (NRL) is testing and demonstrating a prototype moving-map system on amphibious vehicles and landing craft to aid the location neutralization and navigation around mines and obstacles in the surf and beach zone...

An intelligent navigation system for an unmanned surface vehicle

OpenAIRE

Xu , Tao

2007-01-01

Merged with duplicate record 10026.1/2768 on 27.03.2017 by CS (TIS) A multi-disciplinary research project has been carried out at the University of Plymouth to design and develop an Unmanned Surface Vehicle (USV) named ýpringer. The work presented herein relates to formulation of a robust, reliable, accurate and adaptable navigation system to enable opringei to undertake various environmental monitoring tasks. Synergistically, sensor mathematical modelling, fuzzy logic, Multi-S...

Fuzzy Behavior Modulation with Threshold Activation for Autonomous Vehicle Navigation

Science.gov (United States)

Tunstel, Edward

2000-01-01

This paper describes fuzzy logic techniques used in a hierarchical behavior-based architecture for robot navigation. An architectural feature for threshold activation of fuzzy-behaviors is emphasized, which is potentially useful for tuning navigation performance in real world applications. The target application is autonomous local navigation of a small planetary rover. Threshold activation of low-level navigation behaviors is the primary focus. A preliminary assessment of its impact on local navigation performance is provided based on computer simulations.

Navigation API Route Fuel Saving Opportunity Assessment on Large-Scale Real-World Travel Data for Conventional Vehicles and Hybrid Electric Vehicles: Preprint

Energy Technology Data Exchange (ETDEWEB)

Zhu, Lei [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Holden, Jacob [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gonder, Jeffrey D [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-12-06

The green routing strategy instructing a vehicle to select a fuel-efficient route benefits the current transportation system with fuel-saving opportunities. This paper introduces a navigation API route fuel-saving evaluation framework for estimating fuel advantages of alternative API routes based on large-scale, real-world travel data for conventional vehicles (CVs) and hybrid electric vehicles (HEVs). The navigation APIs, such Google Directions API, integrate traffic conditions and provide feasible alternative routes for origin-destination pairs. This paper develops two link-based fuel-consumption models stratified by link-level speed, road grade, and functional class (local/non-local), one for CVs and the other for HEVs. The link-based fuel-consumption models are built by assigning travel from a large number of GPS driving traces to the links in TomTom MultiNet as the underlying road network layer and road grade data from a U.S. Geological Survey elevation data set. Fuel consumption on a link is calculated by the proposed fuel consumption model. This paper envisions two kinds of applications: 1) identifying alternate routes that save fuel, and 2) quantifying the potential fuel savings for large amounts of travel. An experiment based on a large-scale California Household Travel Survey GPS trajectory data set is conducted. The fuel consumption and savings of CVs and HEVs are investigated. At the same time, the trade-off between fuel saving and time saving for choosing different routes is also examined for both powertrains.

Autonomous self-navigating drug-delivery vehicles: from science fiction to reality.

Science.gov (United States)

Petrenko, Valery A

2017-12-01

Low efficacy of targeted nanomedicines in biological experiments enforced us to challenge the traditional concept of drug targeting and suggest a paradigm of 'addressed self-navigating drug-delivery vehicles,' in which affinity selection of targeting peptides and vasculature-directed in vivo phage screening is replaced by the migration selection, which explores ability of 'promiscuous' phages and their proteins to migrate through the tumor-surrounding cellular barriers, using a 'hub and spoke' delivery strategy, and penetrate into the tumor affecting the diverse tumor cell population. The 'self-navigating' drug-delivery paradigm can be used as a theoretical and technical platform in design of a novel generation of molecular medications and imaging probes for precise and personal medicine. [Formula: see text].

Investigation of Matlab® as platform in navigation and control of an Automatic Guided Vehicle utilising an omnivision sensor.

Science.gov (United States)

Kotze, Ben; Jordaan, Gerrit

2014-08-25

Automatic Guided Vehicles (AGVs) are navigated utilising multiple types of sensors for detecting the environment. In this investigation such sensors are replaced and/or minimized by the use of a single omnidirectional camera picture stream. An area of interest is extracted, and by using image processing the vehicle is navigated on a set path. Reconfigurability is added to the route layout by signs incorporated in the navigation process. The result is the possible manipulation of a number of AGVs, each on its own designated colour-signed path. This route is reconfigurable by the operator with no programming alteration or intervention. A low resolution camera and a Matlab® software development platform are utilised. The use of Matlab® lends itself to speedy evaluation and implementation of image processing options on the AGV, but its functioning in such an environment needs to be assessed.

Investigation of Matlab® as Platform in Navigation and Control of an Automatic Guided Vehicle Utilising an Omnivision Sensor

Directory of Open Access Journals (Sweden)

Ben Kotze

2014-08-01

Full Text Available Automatic Guided Vehicles (AGVs are navigated utilising multiple types of sensors for detecting the environment. In this investigation such sensors are replaced and/or minimized by the use of a single omnidirectional camera picture stream. An area of interest is extracted, and by using image processing the vehicle is navigated on a set path. Reconfigurability is added to the route layout by signs incorporated in the navigation process. The result is the possible manipulation of a number of AGVs, each on its own designated colour-signed path. This route is reconfigurable by the operator with no programming alteration or intervention. A low resolution camera and a Matlab® software development platform are utilised. The use of Matlab® lends itself to speedy evaluation and implementation of image processing options on the AGV, but its functioning in such an environment needs to be assessed.

Autonomous vehicle navigation utilizing fuzzy controls concepts for a next generation wheelchair.

Science.gov (United States)

Hansen, J D; Barrett, S F; Wright, C H G; Wilcox, M

2008-01-01

Three different positioning techniques were investigated to create an autonomous vehicle that could accurately navigate towards a goal: Global Positioning System (GPS), compass dead reckoning, and Ackerman steering. Each technique utilized a fuzzy logic controller that maneuvered a four-wheel car towards a target. The reliability and the accuracy of the navigation methods were investigated by modeling the algorithms in software and implementing them in hardware. To implement the techniques in hardware, positioning sensors were interfaced to a remote control car and a microprocessor. The microprocessor utilized the sensor measurements to orient the car with respect to the target. Next, a fuzzy logic control algorithm adjusted the front wheel steering angle to minimize the difference between the heading and bearing. After minimizing the heading error, the car maintained a straight steering angle along its path to the final destination. The results of this research can be used to develop applications that require precise navigation. The design techniques can also be implemented on alternate platforms such as a wheelchair to assist with autonomous navigation.

Inertial Navigation System for India's Reusable Launch Vehicle-Technology Demonstrator (RLV-TD HEX) Mission

Science.gov (United States)

Umadevi, P.; Navas, A.; Karuturi, Kesavabrahmaji; Shukkoor, A. Abdul; Kumar, J. Krishna; Sreekumar, Sreejith; Basim, A. Mohammed

2017-12-01

This work presents the configuration of Inertial Navigation System (INS) used in India's Reusable Launch Vehicle-Technology Demonstrator (RLV-TD) Program. In view of the specific features and requirements of the RLV-TD, specific improvements and modifications were required in the INS. A new system was designed, realised and qualified meeting the mission requirements of RLV-TD, at the same time taking advantage of the flight heritage attained in INS through various Launch vehicle Missions of the country. The new system has additional redundancy in acceleration channel, in-built inclinometer based bias update scheme for acceleration channels and sign conventions as employed in an aircraft. Data acquisition in micro cycle periodicity (10 ms) was incorporated which was required to provide rate and attitude information at higher sampling rate for ascent phase control. Provision was incorporated for acquisition of rate and acceleration data with high resolution for aerodynamic characterisation and parameter estimation. GPS aided navigation scheme was incorporated to meet the stringent accuracy requirements of the mission. Navigation system configuration for RLV-TD, specific features incorporated to meet the mission requirements, various tests carried out and performance during RLV-TD flight are highlighted.

Model-base visual navigation of a mobile robot

International Nuclear Information System (INIS)

Roening, J.

1992-08-01

The thesis considers the problems of visual guidance of a mobile robot. A visual navigation system is formalized consisting of four basic components: world modelling, navigation sensing, navigation and action. According to this formalization an experimental system is designed and realized enabling real-world navigation experiments. A priori knowledge of the world is used for global path finding, aiding scene analysis and providing feedback information to the close the control loop between planned and actual movements. Two world models were developed. The first approach was a map-based model especially designed for low-level description of indoor environments. The other was a higher level and more symbolic representation of the surroundings utilizing the spatial graph concept. Two passive vision approaches were developed to extract navigation information. With passive three- camera stereovision a sparse depth map of the scene was produced. Another approach employed a fish-eye lens to map the entire scene of the surroundings without camera scanning. The local path planning of the system is supported by three-dimensional scene interpreter providing a partial understanding of scene contents. The interpreter consists of data-driven low-level stages and a model-driven high-level stage. Experiments were carried out in a simulator and test vehicle constructed in the laboratory. The test vehicle successfully navigated indoors

The Integration of GPS Navigator Device with Vehicles Tracking System for Rental Cars Firms

OpenAIRE

Omarah O. Alharaki; Fahad S. Alaieri; Akram M. Zeki

2010-01-01

The aim of this research is to integrate the GPS tracking system (tracking device and web-based application) with GPS navigator for rental cars, allowing the company to use various applications to monitor and manage the cars. This is enable the firms and customers to communicate with each other via the GPS navigator. The system should be developed by applying new features in GPS tracking application devices in vehicles. This paper also proposes new features that can be applied to the GPS Navi...

Neural-Network-Based Fuzzy Logic Navigation Control for Intelligent Vehicles

Directory of Open Access Journals (Sweden)

Ahcene Farah

2002-06-01

Full Text Available This paper proposes a Neural-Network-Based Fuzzy logic system for navigation control of intelligent vehicles. First, the use of Neural Networks and Fuzzy Logic to provide intelligent vehicles  with more autonomy and intelligence is discussed. Second, the system  for the obstacle avoidance behavior is developed. Fuzzy Logic improves Neural Networks (NN obstacle avoidance approach by handling imprecision and rule-based approximate reasoning. This system must make the vehicle able, after supervised learning, to achieve two tasks: 1- to make one’s way towards its target by a NN, and 2- to avoid static or dynamic obstacles by a Fuzzy NN capturing the behavior of a human expert. Afterwards, two association phases between each task and the appropriate actions are carried out by Trial and Error learning and their coordination allows to decide the appropriate action. Finally, the simulation results display the generalization and adaptation abilities of the system by testing it in new unexplored environments.

Spatial filtering velocimeter for vehicle navigation with extended measurement range

Science.gov (United States)

He, Xin; Zhou, Jian; Nie, Xiaoming; Long, Xingwu

2015-05-01

The idea of using spatial filtering velocimeter is proposed to provide accurate velocity information for vehicle autonomous navigation system. The presented spatial filtering velocimeter is based on a CMOS linear image sensor. The limited frame rate restricts high speed measurement of the vehicle. To extend measurement range of the velocimeter, a method of frequency shifting is put forward. Theoretical analysis shows that the frequency of output signal can be reduced and the measurement range can be doubled by this method when the shifting direction is set the same with that of image velocity. The approach of fast Fourier transform (FFT) is employed to obtain the power spectra of the spatially filtered signals. Because of limited frequency resolution of FFT, a frequency spectrum correction algorithm, called energy centrobaric correction, is used to improve the frequency resolution. The correction accuracy energy centrobaric correction is analyzed. Experiments are carried out to measure the moving surface of a conveyor belt. The experimental results show that the maximum measurable velocity is about 800deg/s without frequency shifting, 1600deg/s with frequency shifting, when the frame rate of the image is about 8117 Hz. Therefore, the measurement range is doubled by the method of frequency shifting. Furthermore, experiments were carried out to measure the vehicle velocity simultaneously using both the designed SFV and a laser Doppler velocimeter (LDV). The measurement results of the presented SFV are coincident with that of the LDV, but with bigger fluctuation. Therefore, it has the potential of application to vehicular autonomous navigation.

Development of field navigation system; Field navigation system no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Ibara, S; Minode, M; Nishioka, K [Daihatsu Motor Co. Ltd., Osaka (Japan)

1995-04-20

This paper describes the following matters on a field navigation system developed for the purpose of covering a field of several kilometer square. This system consists of a center system and a vehicle system, and the center system comprises a map information computer and a communication data controlling computer; since the accuracy for a vehicle position detected by a GPS is not sufficient, an attempt of increasing the accuracy of vehicle position detection is made by means of a hybrid system; the hybrid system uses a satellite navigation method of differential system in which the error components in the GPS are transmitted from the center, and also uses a self-contained navigation method which performs an auxiliary function when the accuracy in the GPS has dropped; corrected GPS values, emergency messages to all of the vehicles and data of each vehicle position are communicated by wireless transmission in two ways between the center and vehicles; and accommodation of the map data adopted a system that can respond quickly to any change in roads and facilities. 3 refs., 13 figs., 1 tab.

Statistical methods for launch vehicle guidance, navigation, and control (GN&C) system design and analysis

Science.gov (United States)

Rose, Michael Benjamin

A novel trajectory and attitude control and navigation analysis tool for powered ascent is developed. The tool is capable of rapid trade-space analysis and is designed to ultimately reduce turnaround time for launch vehicle design, mission planning, and redesign work. It is streamlined to quickly determine trajectory and attitude control dispersions, propellant dispersions, orbit insertion dispersions, and navigation errors and their sensitivities to sensor errors, actuator execution uncertainties, and random disturbances. The tool is developed by applying both Monte Carlo and linear covariance analysis techniques to a closed-loop, launch vehicle guidance, navigation, and control (GN&C) system. The nonlinear dynamics and flight GN&C software models of a closed-loop, six-degree-of-freedom (6-DOF), Monte Carlo simulation are formulated and developed. The nominal reference trajectory (NRT) for the proposed lunar ascent trajectory is defined and generated. The Monte Carlo truth models and GN&C algorithms are linearized about the NRT, the linear covariance equations are formulated, and the linear covariance simulation is developed. The performance of the launch vehicle GN&C system is evaluated using both Monte Carlo and linear covariance techniques and their trajectory and attitude control dispersion, propellant dispersion, orbit insertion dispersion, and navigation error results are validated and compared. Statistical results from linear covariance analysis are generally within 10% of Monte Carlo results, and in most cases the differences are less than 5%. This is an excellent result given the many complex nonlinearities that are embedded in the ascent GN&C problem. Moreover, the real value of this tool lies in its speed, where the linear covariance simulation is 1036.62 times faster than the Monte Carlo simulation. Although the application and results presented are for a lunar, single-stage-to-orbit (SSTO), ascent vehicle, the tools, techniques, and mathematical

Inertial navigation without accelerometers

Science.gov (United States)

Boehm, M.

The Kennedy-Thorndike (1932) experiment points to the feasibility of fiber-optic inertial velocimeters, to which state-of-the-art technology could furnish substantial sensitivity and accuracy improvements. Velocimeters of this type would obviate the use of both gyros and accelerometers, and allow inertial navigation to be conducted together with vehicle attitude control, through the derivation of rotation rates from the ratios of the three possible velocimeter pairs. An inertial navigator and reference system based on this approach would probably have both fewer components and simpler algorithms, due to the obviation of the first level of integration in classic inertial navigators.

The Study of Intelligent Vehicle Navigation Path Based on Behavior Coordination of Particle Swarm.

Science.gov (United States)

Han, Gaining; Fu, Weiping; Wang, Wen

2016-01-01

In the behavior dynamics model, behavior competition leads to the shock problem of the intelligent vehicle navigation path, because of the simultaneous occurrence of the time-variant target behavior and obstacle avoidance behavior. Considering the safety and real-time of intelligent vehicle, the particle swarm optimization (PSO) algorithm is proposed to solve these problems for the optimization of weight coefficients of the heading angle and the path velocity. Firstly, according to the behavior dynamics model, the fitness function is defined concerning the intelligent vehicle driving characteristics, the distance between intelligent vehicle and obstacle, and distance of intelligent vehicle and target. Secondly, behavior coordination parameters that minimize the fitness function are obtained by particle swarm optimization algorithms. Finally, the simulation results show that the optimization method and its fitness function can improve the perturbations of the vehicle planning path and real-time and reliability.

Navigation Aiding by a Hybrid Laser-Camera Motion Estimator for Micro Aerial Vehicles

Directory of Open Access Journals (Sweden)

Jamal Atman

2016-09-01

Full Text Available Micro Air Vehicles (MAVs equipped with various sensors are able to carry out autonomous flights. However, the self-localization of autonomous agents is mostly dependent on Global Navigation Satellite Systems (GNSS. In order to provide an accurate navigation solution in absence of GNSS signals, this article presents a hybrid sensor. The hybrid sensor is a deep integration of a monocular camera and a 2D laser rangefinder so that the motion of the MAV is estimated. This realization is expected to be more flexible in terms of environments compared to laser-scan-matching approaches. The estimated ego-motion is then integrated in the MAV’s navigation system. However, first, the knowledge about the pose between both sensors is obtained by proposing an improved calibration method. For both calibration and ego-motion estimation, 3D-to-2D correspondences are used and the Perspective-3-Point (P3P problem is solved. Moreover, the covariance estimation of the relative motion is presented. The experiments show very accurate calibration and navigation results.

Navigation Aiding by a Hybrid Laser-Camera Motion Estimator for Micro Aerial Vehicles.

Science.gov (United States)

Atman, Jamal; Popp, Manuel; Ruppelt, Jan; Trommer, Gert F

2016-09-16

Micro Air Vehicles (MAVs) equipped with various sensors are able to carry out autonomous flights. However, the self-localization of autonomous agents is mostly dependent on Global Navigation Satellite Systems (GNSS). In order to provide an accurate navigation solution in absence of GNSS signals, this article presents a hybrid sensor. The hybrid sensor is a deep integration of a monocular camera and a 2D laser rangefinder so that the motion of the MAV is estimated. This realization is expected to be more flexible in terms of environments compared to laser-scan-matching approaches. The estimated ego-motion is then integrated in the MAV's navigation system. However, first, the knowledge about the pose between both sensors is obtained by proposing an improved calibration method. For both calibration and ego-motion estimation, 3D-to-2D correspondences are used and the Perspective-3-Point (P3P) problem is solved. Moreover, the covariance estimation of the relative motion is presented. The experiments show very accurate calibration and navigation results.

Quantum imaging for underwater arctic navigation

Science.gov (United States)

Lanzagorta, Marco

2017-05-01

The precise navigation of underwater vehicles is a difficult task due to the challenges imposed by the variable oceanic environment. It is particularly difficult if the underwater vehicle is trying to navigate under the Arctic ice shelf. Indeed, in this scenario traditional navigation devices such as GPS, compasses and gyrocompasses are unavailable or unreliable. In addition, the shape and thickness of the ice shelf is variable throughout the year. Current Arctic underwater navigation systems include sonar arrays to detect the proximity to the ice. However, these systems are undesirable in a wartime environment, as the sound gives away the position of the underwater vehicle. In this paper we briefly describe the theoretical design of a quantum imaging system that could allow the safe and stealthy navigation of underwater Arctic vehicles.

Sensing and control for autonomous vehicles applications to land, water and air vehicles

CERN Document Server

Pettersen, Kristin; Nijmeijer, Henk

2017-01-01

This edited volume includes thoroughly collected on sensing and control for autonomous vehicles. Guidance, navigation and motion control systems for autonomous vehicles are increasingly important in land-based, marine and aerial operations. Autonomous underwater vehicles may be used for pipeline inspection, light intervention work, underwater survey and collection of oceanographic/biological data. Autonomous unmanned aerial systems can be used in a large number of applications such as inspection, monitoring, data collection, surveillance, etc. At present, vehicles operate with limited autonomy and a minimum of intelligence. There is a growing interest for cooperative and coordinated multi-vehicle systems, real-time re-planning, robust autonomous navigation systems and robust autonomous control of vehicles. Unmanned vehicles with high levels of autonomy may be used for safe and efficient collection of environmental data, for assimilation of climate and environmental models and to complement global satellite sy...

A High-Rate Virtual Instrument of Marine Vehicle Motions for Underwater Navigation and Ocean Remote Sensing

CERN Document Server

Gelin, Chrystel

2013-01-01

Dead-Reckoning aided with Doppler velocity measurement has been the most common method for underwater navigation for small vehicles. Unfortunately DR requires frequent position recalibrations and underwater vehicle navigation systems are limited to periodic position update when they surface. Finally standard Global Positioning System (GPS) receivers are unable to provide the rate or precision required when used on a small vessel. To overcome this, a low cost high rate motion measurement system for an Unmanned Surface Vehicle (USV) with underwater and oceanographic purposes is proposed. The proposed onboard system for the USV consists of an Inertial Measurement Unit (IMU) with accelerometers and rate gyros, a GPS receiver, a flux-gate compass, a roll and tilt sensor and an ADCP. Interfacing all the sensors proved rather challenging because of their different characteristics. The proposed data fusion technique integrates the sensors and develops an embeddable software package, using real time data fusion method...

The Role of Guidance, Navigation, and Control in Hypersonic Vehicle Multidisciplinary Design and Optimization

Science.gov (United States)

Ouzts, Peter J.; Soloway, Donald I.; Moerder, Daniel D.; Wolpert, David H.; Benavides, Jose Victor

2009-01-01

Airbreathing hypersonic systems offer distinct performance advantages over rocket-based systems for space access vehicles. However, these performance advantages are dependent upon advances in current state-of-the-art technologies in many areas such as ram/scramjet propulsion integration, high temperature materials, aero-elastic structures, thermal protection systems, transition to hypersonics and hypersonic control elements within the framework of complex physics and new design methods. The complex interactions between elements of an airbreathing hypersonic vehicle represent a new paradigm in vehicle design to achieve the optimal performance necessary to meet space access mission objectives. In the past, guidance, navigation, and control (GNC) analysis often follows completion of the vehicle conceptual design process. Individual component groups design subsystems which are then integrated into a vehicle configuration. GNC is presented the task of developing control approaches to meet vehicle performance objectives given that configuration. This approach may be sufficient for vehicles where significant performance margins exist. However, for higher performance vehicles engaging the GNC discipline too late in the design cycle has been costly. For example, the X-29 experimental flight vehicle was built as a technology demonstrator. One of the many technologies to be demonstrated was the use of light-weight material composites for structural components. The use of light-weight materials increased the flexibility of the X- 29 beyond that of conventional metal alloy constructed aircraft. This effect was not considered when the vehicle control system was designed and built. The impact of this is that the control system did not have enough control authority to compensate for the effects of the first fundamental structural mode of the vehicle. As a result, the resulting pitch rate response of the vehicle was below specification and no post-design changes could recover the

SLS Model Based Design: A Navigation Perspective

Science.gov (United States)

Oliver, T. Emerson; Anzalone, Evan; Park, Thomas; Geohagan, Kevin

2018-01-01

The SLS Program has implemented a Model-based Design (MBD) and Model-based Requirements approach for managing component design information and system requirements. This approach differs from previous large-scale design efforts at Marshall Space Flight Center where design documentation alone conveyed information required for vehicle design and analysis and where extensive requirements sets were used to scope and constrain the design. The SLS Navigation Team is responsible for the Program-controlled Design Math Models (DMMs) which describe and represent the performance of the Inertial Navigation System (INS) and the Rate Gyro Assemblies (RGAs) used by Guidance, Navigation, and Controls (GN&C). The SLS Navigation Team is also responsible for navigation algorithms. The navigation algorithms are delivered for implementation on the flight hardware as a DMM. For the SLS Block 1B design, the additional GPS Receiver hardware model is managed as a DMM at the vehicle design level. This paper describes the models, and discusses the processes and methods used to engineer, design, and coordinate engineering trades and performance assessments using SLS practices as applied to the GN&C system, with a particular focus on the navigation components.

Control and navigation system for a fixed-wing unmanned aerial vehicle

Directory of Open Access Journals (Sweden)

Ruiyong Zhai

2014-02-01

Full Text Available This paper presents a flight control and navigation system for a fixed-wing unmanned aerial vehicle (UAV with low-cost micro-electro-mechanical system (MEMS sensors. The system is designed under the inner loop and outer loop strategy. The trajectory tracking navigation loop is the outer loop of the attitude loop, while the attitude control loop is the outer loop of the stabilization loop. The proportional-integral-derivative (PID control was adopted for stabilization and attitude control. The three-dimensional (3D trajectory tracking control of a UAV could be approximately divided into lateral control and longitudinal control. The longitudinal control employs traditional linear PID feedback to achieve the desired altitude of the UAV, while the lateral control uses a non-linear control method to complete the desired trajectory. The non-linear controller can automatically adapt to ground velocity change, which is usually caused by gust disturbance, thus the UAV has good wind resistance characteristics. Flight tests and survey missions were carried out with our self-developed delta fixed-wing UAV and MEMS-based autopilot to confirm the effectiveness and practicality of the proposed navigation method.

BOREAS Level-0 ER-2 Navigation Data

Science.gov (United States)

Strub, Richard; Dominguez, Roseanne; Newcomer, Jeffrey A.; Hall, Forrest G. (Editor)

2000-01-01

The BOREAS Staff Science effort covered those activities that were BOREAS community-level activities or required uniform data collection procedures across sites and time. These activities included the acquisition, processing, and archiving of aircraft navigation/attitude data to complement the digital image data. The level-0 ER-2 navigation data files contain aircraft attitude and position information acquired during the digital image and photographic data collection missions. Temporally, the data were acquired from April to September 1994. Data were recorded at intervals of 5 seconds. The data are stored in tabular ASCII files.

Measuring water level in rivers and lakes from lightweight Unmanned Aerial Vehicles

DEFF Research Database (Denmark)

Bandini, Filippo; Jakobsen, Jakob; Olesen, Daniel Haugård

2017-01-01

The assessment of hydrologic dynamics in rivers, lakes, reservoirs and wetlands requires measurements of water level, its temporal and spatial derivatives, and the extent and dynamics of open water surfaces. Motivated by the declining number of ground-based measurement stations, research efforts...... complex water dynamics. Unmanned Aerial Vehicles (UAVs) can fill the gap between spaceborne and ground-based observations, and provide high spatial resolution and dense temporal coverage data, in quick turn-around time, using flexible payload design. This study focused on categorizing and testing sensors......, which comply with the weight constraint of small UAVs (around 1.5 kg), capable of measuring the range to water surface. Subtracting the measured range from the vertical position retrieved by the onboard Global Navigation Satellite System (GNSS) receiver, we can determine the water level (orthometric...

High–Level Control System for Biomimetic Autonomous Under-water Vehicle

Directory of Open Access Journals (Sweden)

Praczyk Tomasz

2017-01-01

Full Text Available Usually, a rough software architecture designed for a robot can be can be shortly presented in the form of layers. The lowest layer is responsible for direct control of the hardware, i.e. engines, energy system, sensors, navigation devices, etc. A next layer is a low–level control which knows how to use the hardware in order to achieve a desired state of the robot, e.g. to stay on a desired course. And the last layer, the layer which is the nearest to the human–operator, is a high–level control which decides how to use the low–level control and sometimes also individual pieces of the hardware to achieve predefined objectives. The paper describes architecture, tasks and operation of the high–level control system (HLCS designed for Biomimetic Autonomous Underwater Vehicle (BAUV.

Satellite Imagery Assisted Road-Based Visual Navigation System

Science.gov (United States)

Volkova, A.; Gibbens, P. W.

2016-06-01

There is a growing demand for unmanned aerial systems as autonomous surveillance, exploration and remote sensing solutions. Among the key concerns for robust operation of these systems is the need to reliably navigate the environment without reliance on global navigation satellite system (GNSS). This is of particular concern in Defence circles, but is also a major safety issue for commercial operations. In these circumstances, the aircraft needs to navigate relying only on information from on-board passive sensors such as digital cameras. An autonomous feature-based visual system presented in this work offers a novel integral approach to the modelling and registration of visual features that responds to the specific needs of the navigation system. It detects visual features from Google Earth* build a feature database. The same algorithm then detects features in an on-board cameras video stream. On one level this serves to localise the vehicle relative to the environment using Simultaneous Localisation and Mapping (SLAM). On a second level it correlates them with the database to localise the vehicle with respect to the inertial frame. The performance of the presented visual navigation system was compared using the satellite imagery from different years. Based on comparison results, an analysis of the effects of seasonal, structural and qualitative changes of the imagery source on the performance of the navigation algorithm is presented. * The algorithm is independent of the source of satellite imagery and another provider can be used

Navigational efficiency of nocturnal Myrmecia ants suffers at low light levels.

Directory of Open Access Journals (Sweden)

Ajay Narendra

Full Text Available Insects face the challenge of navigating to specific goals in both bright sun-lit and dim-lit environments. Both diurnal and nocturnal insects use quite similar navigation strategies. This is despite the signal-to-noise ratio of the navigational cues being poor at low light conditions. To better understand the evolution of nocturnal life, we investigated the navigational efficiency of a nocturnal ant, Myrmecia pyriformis, at different light levels. Workers of M. pyriformis leave the nest individually in a narrow light-window in the evening twilight to forage on nest-specific Eucalyptus trees. The majority of foragers return to the nest in the morning twilight, while few attempt to return to the nest throughout the night. We found that as light levels dropped, ants paused for longer, walked more slowly, the success in finding the nest reduced and their paths became less straight. We found that in both bright and dark conditions ants relied predominantly on visual landmark information for navigation and that landmark guidance became less reliable at low light conditions. It is perhaps due to the poor navigational efficiency at low light levels that the majority of foragers restrict navigational tasks to the twilight periods, where sufficient navigational information is still available.

Autonomous GPS/INS navigation experiment for Space Transfer Vehicle

Science.gov (United States)

Upadhyay, Triveni N.; Cotterill, Stephen; Deaton, A. W.

1993-01-01

An experiment to validate the concept of developing an autonomous integrated spacecraft navigation system using on board Global Positioning System (GPS) and Inertial Navigation System (INS) measurements is described. The feasibility of integrating GPS measurements with INS measurements to provide a total improvement in spacecraft navigation performance, i.e. improvement in position, velocity and attitude information, was previously demonstrated. An important aspect of this research is the automatic real time reconfiguration capability of the system designed to respond to changes in a spacecraft mission under the control of an expert system.

Lunar Navigation Architecture Design Considerations

Science.gov (United States)

D'Souza, Christopher; Getchius, Joel; Holt, Greg; Moreau, Michael

2009-01-01

The NASA Constellation Program is aiming to establish a long-term presence on the lunar surface. The Constellation elements (Orion, Altair, Earth Departure Stage, and Ares launch vehicles) will require a lunar navigation architecture for navigation state updates during lunar-class missions. Orion in particular has baselined earth-based ground direct tracking as the primary source for much of its absolute navigation needs. However, due to the uncertainty in the lunar navigation architecture, the Orion program has had to make certain assumptions on the capabilities of such architectures in order to adequately scale the vehicle design trade space. The following paper outlines lunar navigation requirements, the Orion program assumptions, and the impacts of these assumptions to the lunar navigation architecture design. The selection of potential sites was based upon geometric baselines, logistical feasibility, redundancy, and abort support capability. Simulated navigation covariances mapped to entry interface flightpath- angle uncertainties were used to evaluate knowledge errors. A minimum ground station architecture was identified consisting of Goldstone, Madrid, Canberra, Santiago, Hartebeeshoek, Dongora, Hawaii, Guam, and Ascension Island (or the geometric equivalent).

Space Launch Systems Block 1B Preliminary Navigation System Design

Science.gov (United States)

Oliver, T. Emerson; Park, Thomas; Anzalone, Evan; Smith, Austin; Strickland, Dennis; Patrick, Sean

2018-01-01

NASA is currently building the Space Launch Systems (SLS) Block 1 launch vehicle for the Exploration Mission 1 (EM-1) test flight. In parallel, NASA is also designing the Block 1B launch vehicle. The Block 1B vehicle is an evolution of the Block 1 vehicle and extends the capability of the NASA launch vehicle. This evolution replaces the Interim Cryogenic Propulsive Stage (ICPS) with the Exploration Upper Stage (EUS). As the vehicle evolves to provide greater lift capability, increased robustness for manned missions, and the capability to execute more demanding missions so must the SLS Integrated Navigation System evolved to support those missions. This paper describes the preliminary navigation systems design for the SLS Block 1B vehicle. The evolution of the navigation hard-ware and algorithms from an inertial-only navigation system for Block 1 ascent flight to a tightly coupled GPS-aided inertial navigation system for Block 1B is described. The Block 1 GN&C system has been designed to meet a LEO insertion target with a specified accuracy. The Block 1B vehicle navigation system is de-signed to support the Block 1 LEO target accuracy as well as trans-lunar or trans-planetary injection accuracy. Additionally, the Block 1B vehicle is designed to support human exploration and thus is designed to minimize the probability of Loss of Crew (LOC) through high-quality inertial instruments and robust algorithm design, including Fault Detection, Isolation, and Recovery (FDIR) logic.

Target Trailing With Safe Navigation With Colregs for Maritime Autonomous Surface Vehicles

Science.gov (United States)

Kuwata, Yoshiaki (Inventor); Wolf, Michael T. (Inventor); Zarzhitsky, Dimitri V. (Inventor); Aghazarian, Hrand (Inventor); Huntsberger, Terrance L. (Inventor); Howard, Andrew B. (Inventor)

2014-01-01

Systems and methods for operating autonomous waterborne vessels in a safe manner. The systems include hardware for identifying the locations and motions of other vessels, as well as the locations of stationary objects that represent navigation hazards. By applying a computational method that uses a maritime navigation algorithm for avoiding hazards and obeying COLREGS using Velocity Obstacles to the data obtained, the autonomous vessel computes a safe and effective path to be followed in order to accomplish a desired navigational end result, while operating in a manner so as to avoid hazards and to maintain compliance with standard navigational procedures defined by international agreement. The systems and methods have been successfully demonstrated on water with radar and stereo cameras as the perception sensors, and integrated with a higher level planner for trailing a maneuvering target.

Tightly-Coupled GNSS/Vision Using a Sky-Pointing Camera for Vehicle Navigation in Urban Areas.

Science.gov (United States)

Gakne, Paul Verlaine; O'Keefe, Kyle

2018-04-17

This paper presents a method of fusing the ego-motion of a robot or a land vehicle estimated from an upward-facing camera with Global Navigation Satellite System (GNSS) signals for navigation purposes in urban environments. A sky-pointing camera is mounted on the top of a car and synchronized with a GNSS receiver. The advantages of this configuration are two-fold: firstly, for the GNSS signals, the upward-facing camera will be used to classify the acquired images into sky and non-sky (also known as segmentation). A satellite falling into the non-sky areas (e.g., buildings, trees) will be rejected and not considered for the final position solution computation. Secondly, the sky-pointing camera (with a field of view of about 90 degrees) is helpful for urban area ego-motion estimation in the sense that it does not see most of the moving objects (e.g., pedestrians, cars) and thus is able to estimate the ego-motion with fewer outliers than is typical with a forward-facing camera. The GNSS and visual information systems are tightly-coupled in a Kalman filter for the final position solution. Experimental results demonstrate the ability of the system to provide satisfactory navigation solutions and better accuracy than the GNSS-only and the loosely-coupled GNSS/vision, 20 percent and 82 percent (in the worst case) respectively, in a deep urban canyon, even in conditions with fewer than four GNSS satellites.

Ego-motion based on EM for bionic navigation

Science.gov (United States)

Yue, Xiaofeng; Wang, L. J.; Liu, J. G.

2015-12-01

Researches have proved that flying insects such as bees can achieve efficient and robust flight control, and biologists have explored some biomimetic principles regarding how they control flight. Based on those basic studies and principles acquired from the flying insects, this paper proposes a different solution of recovering ego-motion for low level navigation. Firstly, a new type of entropy flow is provided to calculate the motion parameters. Secondly, EKF, which has been used for navigation for some years to correct accumulated error, and estimation-Maximization, which is always used to estimate parameters, are put together to determine the ego-motion estimation of aerial vehicles. Numerical simulation on MATLAB has proved that this navigation system provides more accurate position and smaller mean absolute error than pure optical flow navigation. This paper has done pioneering work in bionic mechanism to space navigation.

Integrating GPS, GYRO, vehicle speed sensor, and digital map to provide accurate and real-time position in an intelligent navigation system

Science.gov (United States)

Li, Qingquan; Fang, Zhixiang; Li, Hanwu; Xiao, Hui

2005-10-01

The global positioning system (GPS) has become the most extensively used positioning and navigation tool in the world. Applications of GPS abound in surveying, mapping, transportation, agriculture, military planning, GIS, and the geosciences. However, the positional and elevation accuracy of any given GPS location is prone to error, due to a number of factors. The applications of Global Positioning System (GPS) positioning is more and more popular, especially the intelligent navigation system which relies on GPS and Dead Reckoning technology is developing quickly for future huge market in China. In this paper a practical combined positioning model of GPS/DR/MM is put forward, which integrates GPS, Gyro, Vehicle Speed Sensor (VSS) and digital navigation maps to provide accurate and real-time position for intelligent navigation system. This model is designed for automotive navigation system making use of Kalman filter to improve position and map matching veracity by means of filtering raw GPS and DR signals, and then map-matching technology is used to provide map coordinates for map displaying. In practical examples, for illustrating the validity of the model, several experiments and their results of integrated GPS/DR positioning in intelligent navigation system will be shown for the conclusion that Kalman Filter based GPS/DR integrating position approach is necessary, feasible and efficient for intelligent navigation application. Certainly, this combined positioning model, similar to other model, can not resolve all situation issues. Finally, some suggestions are given for further improving integrated GPS/DR/MM application.

Surface navigation on Mars with a Navigation Satellite

Science.gov (United States)

Vijayaraghavan, A.; Thurman, Sam W.; Kahn, Robert D.; Hastrup, Rolf C.

Radiometric navigation data from the Deep Space Network (DSN) stations on the earth to transponders and other surface elements such as rovers and landers on Mars, can determine their positions to only within a kilometer in inertial space. The positional error is mostly in the z-component of the surface element parallel to the Martian spin-axis. However, with Doppler and differenced-Doppler data from a Navigation Satellite in orbit around Mars to two or more of such transponders on the planetary surface, their positions can be determined to within 15 meters (or 20 meters for one-way Doppler beacons on Mars) in inertial space. In this case, the transponders (or other vehicles) on Mars need not even be capable of directly communicating to the earth. When the Navigation Satellite data is complemented by radiometric observations from the DSN stations also, directly to the surface elements on Mars, their positions can be determined to within 3 meters in inertial space. The relative positions of such surface elements on Mars (relative to one another) in Mars-fixed coordinates, however, can be determined to within 5 meters from simply range and Doppler data from the DSN stations to the surface elements. These results are obtained from covariance studies assuming X-band data noise levels and data-arcs not exceeding 10 days. They are significant in the planning and deployment of a Mars-based navigation network necessary to support real-time operations during critical phases of manned exploration of Mars.

Bilateral human-robot control for semi-autonomous UAV navigation

NARCIS (Netherlands)

Wopereis, Han Willem; Fumagalli, Matteo; Stramigioli, Stefano; Carloni, Raffaella

2015-01-01

This paper proposes a semi-autonomous bilateral control architecture for unmanned aerial vehicles. During autonomous navigation, a human operator is allowed to assist the autonomous controller of the vehicle by actively changing its navigation parameters to assist it in critical situations, such as

An IMM-Aided ZUPT Methodology for an INS/DVL Integrated Navigation System.

Science.gov (United States)

Yao, Yiqing; Xu, Xiaosu; Xu, Xiang

2017-09-05

Inertial navigation system (INS)/Doppler velocity log (DVL) integration is the most common navigation solution for underwater vehicles. Due to the complex underwater environment, the velocity information provided by DVL always contains some errors. To improve navigation accuracy, zero velocity update (ZUPT) technology is considered, which is an effective algorithm for land vehicles to mitigate the navigation error during the pure INS mode. However, in contrast to ground vehicles, the ZUPT solution cannot be used directly for underwater vehicles because of the existence of the water current. In order to leverage the strengths of the ZUPT method and the INS/DVL solution, an interactive multiple model (IMM)-aided ZUPT methodology for the INS/DVL-integrated underwater navigation system is proposed. Both the INS/DVL and INS/ZUPT models are constructed and operated in parallel, with weights calculated according to their innovations and innovation covariance matrices. Simulations are conducted to evaluate the proposed algorithm. The results indicate that the IMM-aided ZUPT solution outperforms both the INS/DVL solution and the INS/ZUPT solution in the underwater environment, which can properly distinguish between the ZUPT and non-ZUPT conditions. In addition, during DVL outage, the effectiveness of the proposed algorithm is also verified.

Mars rover local navigation and hazard avoidance

Science.gov (United States)

Wilcox, B. H.; Gennery, D. B.; Mishkin, A. H.

1989-01-01

A Mars rover sample return mission has been proposed for the late 1990's. Due to the long speed-of-light delays between earth and Mars, some autonomy on the rover is highly desirable. JPL has been conducting research in two possible modes of rover operation, Computer-Aided Remote Driving and Semiautonomous Navigation. A recently-completed research program used a half-scale testbed vehicle to explore several of the concepts in semiautonomous navigation. A new, full-scale vehicle with all computational and power resources on-board will be used in the coming year to demonstrate relatively fast semiautonomous navigation. The computational and power requirements for Mars rover local navigation and hazard avoidance are discussed.

Autonomous GPS/INS navigation experiment for Space Transfer Vehicle (STV)

Science.gov (United States)

Upadhyay, Triveni N.; Cotterill, Stephen; Deaton, A. Wayne

1991-01-01

An experiment to validate the concept of developing an autonomous integrated spacecraft navigation system using on board Global Positioning System (GPS) and Inertial Navigation System (INS) measurements is described. The feasibility of integrating GPS measurements with INS measurements to provide a total improvement in spacecraft navigation performance, i.e. improvement in position, velocity and attitude information, was previously demonstrated. An important aspect of this research is the automatic real time reconfiguration capability of the system designed to respond to changes in a spacecraft mission under the control of an expert system.

New Navigation Post-Processing Tools for Oceanographic Submersibles

Science.gov (United States)

Kinsey, J. C.; Whitcomb, L. L.; Yoerger, D. R.; Howland, J. C.; Ferrini, V. L.; Hegrenas, O.

2006-12-01

We report the development of Navproc, a new set of software tools for post-processing oceanographic submersible navigation data that exploits previously reported improvements in navigation sensing and estimation (e.g. Eos Trans. AGU, 84(46), Fall Meet. Suppl., Abstract OS32A- 0225, 2003). The development of these tools is motivated by the need to have post-processing software that allows users to compensate for errors in vehicle navigation, recompute the vehicle position, and then save the results for use with quantitative science data (e.g. bathymetric sonar data) obtained during the mission. Navproc does not provide real-time navigation or display of data nor is it capable of high-resolution, three dimensional (3D) data display. Navproc supports the ASCII data formats employed by the vehicles of the National Deep Submergence Facility (NDSF) operated by the Woods Hole Oceanographic Institution (WHOI). Post-processing of navigation data with Navproc is comprised of three tasks. First, data is converted from the logged ASCII file to a binary Matlab file. When loaded into Matlab, each sensor has a data structure containing the time stamped data sampled at the native update rate of the sensor. An additional structure contains the real-time vehicle navigation data. Second, the data can be displayed using a Graphical User Interface (GUI), allowing users to visually inspect the quality of the data and graphically extract portions of the data. Third, users can compensate for errors in the real-time vehicle navigation. Corrections include: (i) manual filtering and median filtering of long baseline (LBL) ranges; (ii) estimation of the Doppler/gyro alignment using previously reported methodologies; and (iii) sound velocity, tide, and LBL transponder corrections. Using these corrections, the Doppler and LBL positions can be recomputed to provide improved estimates of the vehicle position compared to those computed in real-time. The data can be saved in either binary or ASCII

Lane-Level Vehicle Trajectory Reckoning for Cooperative Vehicle-Infrastructure System

Directory of Open Access Journals (Sweden)

Yinsong Wang

2012-01-01

Full Text Available This paper presents a lane-level positioning method by trajectory reckoning without Global Positioning System (GPS equipment in the environment of Cooperative Vehicle-Infrastructure System (CVIS. Firstly, the accuracy requirements of vehicle position in CVIS applications and the applicability of GPS positioning methods were analyzed. Then, a trajectory reckoning method based on speed and steering data from vehicle’s Control Area Network (CAN and roadside calibration facilities was proposed, which consists of three critical models, including real-time estimation of steering angle and vehicle direction, vehicle movement reckoning, and wireless calibration. Finally, the proposed method was validated through simulation and field tests under a variety of traffic conditions. Results show that the accuracy of the reckoned vehicle position can reach the lane level and match the requirements of common CVIS applications.

SLS Block 1-B and Exploration Upper Stage Navigation System Design

Science.gov (United States)

Oliver, T. Emerson; Park, Thomas B.; Smith, Austin; Anzalone, Evan; Bernard, Bill; Strickland, Dennis; Geohagan, Kevin; Green, Melissa; Leggett, Jarred

2018-01-01

The SLS Block 1B vehicle is planned to extend NASA's heavy lift capability beyond the initial SLS Block 1 vehicle. The most noticeable change for this vehicle from SLS Block 1 is the swapping of the upper stage from the Interim Cryogenic Propulsion stage (ICPS), a modified Delta IV upper stage, to the more capable Exploration Upper Stage (EUS). As the vehicle evolves to provide greater lift capability and execute more demanding missions so must the SLS Integrated Navigation System to support those missions. The SLS Block 1 vehicle carries two independent navigation systems. The responsibility of the two systems is delineated between ascent and upper stage flight. The Block 1 navigation system is responsible for the phase of flight between the launch pad and insertion into Low-Earth Orbit (LEO). The upper stage system assumes the mission from LEO to payload separation. For the Block 1B vehicle, the two functions are combined into a single system intended to navigate from ground to payload insertion. Both are responsible for self-disposal once payload delivery is achieved. The evolution of the navigation hardware and algorithms from an inertial-only navigation system for Block 1 ascent flight to a tightly coupled GPS-aided inertial navigation system for Block 1-B is described. The Block 1 GN&C system has been designed to meet a LEO insertion target with a specified accuracy. The Block 1-B vehicle navigation system is designed to support the Block 1 LEO target accuracy as well as trans-lunar or trans-planetary injection accuracy. This is measured in terms of payload impact and stage disposal requirements. Additionally, the Block 1-B vehicle is designed to support human exploration and thus is designed to minimize the probability of Loss of Crew (LOC) through high-quality inertial instruments and Fault Detection, Isolation, and Recovery (FDIR) logic. The preliminary Block 1B integrated navigation system design is presented along with the challenges associated with

33 CFR 127.1311 - Motor vehicles.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Motor vehicles. 127.1311 Section... Waterfront Facilities Handling Liquefied Hazardous Gas Operations § 127.1311 Motor vehicles. (a) When LHG is... operator shall ensure that no person— (1) Stops or parks a motor vehicle in a space other than a designated...

Fuzzy adaptive integration scheme for low-cost SINS/GPS navigation system

Science.gov (United States)

Nourmohammadi, Hossein; Keighobadi, Jafar

2018-01-01

Due to weak stand-alone accuracy as well as poor run-to-run stability of micro-electro mechanical system (MEMS)-based inertial sensors, special approaches are required to integrate low-cost strap-down inertial navigation system (SINS) with global positioning system (GPS), particularly in long-term applications. This paper aims to enhance long-term performance of conventional SINS/GPS navigation systems using a fuzzy adaptive integration scheme. The main concept behind the proposed adaptive integration is the good performance of attitude-heading reference system (AHRS) in low-accelerated motions and its degradation in maneuvered or accelerated motions. Depending on vehicle maneuvers, gravity-based attitude angles can be intelligently utilized to improve orientation estimation in the SINS. Knowledge-based fuzzy inference system is developed for decision-making between the AHRS and the SINS according to vehicle maneuvering conditions. Inertial measurements are the main input data of the fuzzy system to determine the maneuvering level during the vehicle motions. Accordingly, appropriate weighting coefficients are produced to combine the SINS/GPS and the AHRS, efficiently. The assessment of the proposed integrated navigation system is conducted via real data in airborne tests.

Magnetic navigation and tracking of underwater vehicles

Digital Repository Service at National Institute of Oceanography (India)

Teixeira, F.C.; Pascoal, A.M.

for the navigation of AUVs has been proposed many years ago but the concept still requires practical demonstration. Implementation issues One of the advantages of mag- netic navigation consists in being passive and economical in terms of energy. Magnetic sensors do... like the present one, that require magnetic measurements with very high precision. A typical solution to this problem consists in the placement of magnetic sensors as far away as possible from the sources of noise but this may not be practical...

Robotics Vision-based Heuristic Reasoning for Underwater Target Tracking and Navigation

OpenAIRE

Kia, Chua; Arshad, Mohd Rizal

2006-01-01

This paper presents a robotics vision-based heuristic reasoning system for underwater target tracking and navigation. This system is introduced to improve the level of automation of underwater Remote Operated Vehicles (ROVs) operations. A prototype which combines computer vision with an underwater robotics system is successfully designed and developed to perform target tracking and intelligent navigation. This study focuses on developing image processing algorithms and fuzzy inference system ...

Development of a new automotive navigation system; Shingata navigation system no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Sone, M; Nakano, H; Nakayama, O; Tanemura, E; Yoshitsugu, N; Watanabe, M [Nissan Motor Co. Ltd., Tokyo (Japan)

1996-01-31

An automotive navigation system was outlined. Features of this system are described below: map display called `Bird View` extending up to the horizon was commercialized; accuracy of determining the vehicle`s present position was realized using new algorithm; and automatic route selection was adopted. Human machine interface of this system also was completely reviewed. `Bird View` was realized by reading plane map data out from CD-ROM and converting them onto the coordinate on the virtual screen in front of the view point. Automatic selection which depends mostly on self-contained navigation adopts the certain way in comparison of the computation position in GPS. To assume vehicle advancing direction, employed were optical fiber gyroscope, geomagnetic sensor, and Karman filter making a good use of advantages of GPS, for the improvement of accuracy. For the automatic distance correction, a function of correcting pulse-distance conversion coefficient was employed, and the free maintenance was realized. 5 figs.

Mars Atmospheric Entry Integrated Navigation with Partial Intermittent Measurements

Directory of Open Access Journals (Sweden)

Tai-shan Lou

2017-01-01

Full Text Available Signal degradation suffered by the vehicle is a combination brownout and blackout during Mars atmospheric entry. The communications brownout means that signal fades and blackout means that the signal is lost completely. The communications brownout and blackout periods are analyzed and predicted with an altitude and velocity profiles. In the brownout period, the range measurements between the vehicle and the orbiters are modeled as intermittent measurements with the radio signal arrival probabilities, which are distributed as a Rayleigh distribution of the electron number density around the entry vehicle. A new integrated navigation strategy during the Mars atmospheric entry phase is proposed to consider the probabilities of the radio measurements in the communications brownout and blackout periods under the IMU/beacon scenario based on the information filter with intermittent measurements. Numerical navigation simulations are designed to show the performance of the proposed navigation strategy under the integrated navigation scenario.

Development of Fast Error Compensation Algorithm for Integrated Inertial-Satellite Navigation System of Small-size Unmanned Aerial Vehicles in Complex Environment

Directory of Open Access Journals (Sweden)

A. V. Fomichev

2015-01-01

Full Text Available In accordance with the structural features of small-size unmanned aerial vehicle (UAV, and considering the feasibility of this project, the article studies an integrated inertial-satellite navigation system (INS. The INS algorithm development is based on the method of indirect filtration and principle of loosely coupled combination of output data on UAV positions and velocity. Data on position and velocity are provided from the strapdown inertial navigation system (SINS and satellite navigation system (GPS. A difference between the output flows of measuring data on position and velocity provided from the SINS and GPS is used to evaluate SINS errors by means of the basic algorithm of Kalman filtering. Then the outputs of SINS are revised. The INS possesses the following advantages: a simpler mathematical model of Kalman filtering, high reliability, two independently operating navigation systems, and high redundancy of available navigation information.But in case of loosely coupled scheme, INS can meet the challenge of high precision and reliability of navigation only when the SINS and GPS operating conditions are normal all the time. The proposed INS is used with UAV moving in complex environment due to obstacles available, severe natural climatic conditions, etc. This case expects that it is impossible for UAV to receive successful GPS-signals frequently. In order to solve this problem, was developed an algorithm for rapid compensation for errors of INS information, which could effectively solve the problem of failure of the navigation system in case there are no GPS-signals .Since it is almost impossible to obtain the data of the real trajectory in practice, in the course of simulation in accordance with the kinematic model of the UAV and the complex environment of the terrain, the flight path generator is used to produce the flight path. The errors of positions and velocities are considered as an indicator of the INS effectiveness. The results

Using Genetic Algorithms for Navigation Planning in Dynamic Environments

Directory of Open Access Journals (Sweden)

Ferhat Uçan

2012-01-01

Full Text Available Navigation planning can be considered as a combination of searching and executing the most convenient flight path from an initial waypoint to a destination waypoint. Generally the aim is to follow the flight path, which provides minimum fuel consumption for the air vehicle. For dynamic environments, constraints change dynamically during flight. This is a special case of dynamic path planning. As the main concern of this paper is flight planning, the conditions and objectives that are most probable to be used in navigation problem are considered. In this paper, the genetic algorithm solution of the dynamic flight planning problem is explained. The evolutionary dynamic navigation planning algorithm is developed for compensating the existing deficiencies of the other approaches. The existing fully dynamic algorithms process unit changes to topology one modification at a time, but when there are several such operations occurring in the environment simultaneously, the algorithms are quite inefficient. The proposed algorithm may respond to the concurrent constraint updates in a shorter time for dynamic environment. The most secure navigation of the air vehicle is planned and executed so that the fuel consumption is minimum.

Golf cart prototype development and navigation simulation using ROS and Gazebo

Directory of Open Access Journals (Sweden)

Shimchik Ilya

2016-01-01

Full Text Available This paper presents our approach to development of an autonomous golf cart, which will navigate in inaccessible by regular vehicles private areas. For this purpose, we have built a virtual golf course terrain and golf cart model in Gazebo, selected and modernized ROS-based packages in order to use them with Ackermann steering vehicle simulation. To verify our simulation and algorithms, we navigated the golf cart model from one golf hole to another within a virtual 3D golf course. For the real world algorithms’ verification, we developed a small-size vehicle prototype based on Traxxas radio-controlled car model, which is equipped with an on-board controller and sensors. The autonomous navigation of Traxxas-based vehicle prototype has been tested in indoor environment, where it utilized sensory data about environment and vehicle states, and performed localization, optimal trajectory computation and dynamic obstacles’ recognition with adjusting the route in real time.

Overcoming urban GPS navigation challenges through the use of MEMS inertial sensors and proper verification of navigation system performance

Science.gov (United States)

Vinande, Eric T.

This research proposes several means to overcome challenges in the urban environment to ground vehicle global positioning system (GPS) receiver navigation performance through the integration of external sensor information. The effects of narrowband radio frequency interference and signal attenuation, both common in the urban environment, are examined with respect to receiver signal tracking processes. Low-cost microelectromechanical systems (MEMS) inertial sensors, suitable for the consumer market, are the focus of receiver augmentation as they provide an independent measure of motion and are independent of vehicle systems. A method for estimating the mounting angles of an inertial sensor cluster utilizing typical urban driving maneuvers is developed and is able to provide angular measurements within two degrees of truth. The integration of GPS and MEMS inertial sensors is developed utilizing a full state navigation filter. Appropriate statistical methods are developed to evaluate the urban environment navigation improvement due to the addition of MEMS inertial sensors. A receiver evaluation metric that combines accuracy, availability, and maximum error measurements is presented and evaluated over several drive tests. Following a description of proper drive test techniques, record and playback systems are evaluated as the optimal way of testing multiple receivers and/or integrated navigation systems in the urban environment as they simplify vehicle testing requirements.

Extrinsic Parameter Calibration for Line Scanning Cameras on Ground Vehicles with Navigation Systems Using a Calibration Pattern

Directory of Open Access Journals (Sweden)

Alexander Wendel

2017-10-01

Full Text Available Line scanning cameras, which capture only a single line of pixels, have been increasingly used in ground based mobile or robotic platforms. In applications where it is advantageous to directly georeference the camera data to world coordinates, an accurate estimate of the camera’s 6D pose is required. This paper focuses on the common case where a mobile platform is equipped with a rigidly mounted line scanning camera, whose pose is unknown, and a navigation system providing vehicle body pose estimates. We propose a novel method that estimates the camera’s pose relative to the navigation system. The approach involves imaging and manually labelling a calibration pattern with distinctly identifiable points, triangulating these points from camera and navigation system data and reprojecting them in order to compute a likelihood, which is maximised to estimate the 6D camera pose. Additionally, a Markov Chain Monte Carlo (MCMC algorithm is used to estimate the uncertainty of the offset. Tested on two different platforms, the method was able to estimate the pose to within 0.06 m/1.05 ∘ and 0.18 m/2.39 ∘ . We also propose several approaches to displaying and interpreting the 6D results in a human readable way.

How important is vehicle safety in the new vehicle purchase process?

Science.gov (United States)

Koppel, Sjaanie; Charlton, Judith; Fildes, Brian; Fitzharris, Michael

2008-05-01

Whilst there has been a significant increase in the amount of consumer interest in the safety performance of privately owned vehicles, the role that it plays in consumers' purchase decisions is poorly understood. The aims of the current study were to determine: how important vehicle safety is in the new vehicle purchase process; what importance consumers place on safety options/features relative to other convenience and comfort features, and how consumers conceptualise vehicle safety. In addition, the study aimed to investigate the key parameters associated with ranking 'vehicle safety' as the most important consideration in the new vehicle purchase. Participants recruited in Sweden and Spain completed a questionnaire about their new vehicle purchase. The findings from the questionnaire indicated that participants ranked safety-related factors (e.g., EuroNCAP (or other) safety ratings) as more important in the new vehicle purchase process than other vehicle factors (e.g., price, reliability etc.). Similarly, participants ranked safety-related features (e.g., advanced braking systems, front passenger airbags etc.) as more important than non-safety-related features (e.g., route navigation systems, air-conditioning etc.). Consistent with previous research, most participants equated vehicle safety with the presence of specific vehicle safety features or technologies rather than vehicle crash safety/test results or crashworthiness. The key parameters associated with ranking 'vehicle safety' as the most important consideration in the new vehicle purchase were: use of EuroNCAP, gender and education level, age, drivers' concern about crash involvement, first vehicle purchase, annual driving distance, person for whom the vehicle was purchased, and traffic infringement history. The findings from this study are important for policy makers, manufacturers and other stakeholders to assist in setting priorities with regard to the promotion and publicity of vehicle safety features

Electric vehicle data acquisition system

DEFF Research Database (Denmark)

Svendsen, Mathias; Winther-Jensen, Mads; Pedersen, Anders Bro

2014-01-01

and industrial applications, e.g. research in electric vehicle driving patterns, vehicle substitutability analysis and fleet management. The platform is based on a embedded computer running Linux, and features a high level of modularity and flexibility. The system operates independently of the make of the car......, by using the On-board Diagnostic port to identify car model and adapt its software accordingly. By utilizing on-board Global Navigation Satellite System, General Packet Radio Service, accelerometer, gyroscope and magnetometer, the system not only provides valuable data for research in the field of electric......A data acquisition system for electric vehicles is presented. The system connects to the On-board Diagnostic port of newer vehicles, and utilizes the in-vehicle sensor network, as well as auxiliary sensors, to gather data. Data is transmitted continuously to a central database for academic...

Demonstration of coherent Doppler lidar for navigation in GPS-denied environments

Science.gov (United States)

Amzajerdian, Farzin; Hines, Glenn D.; Pierrottet, Diego F.; Barnes, Bruce W.; Petway, Larry B.; Carson, John M.

2017-05-01

A coherent Doppler lidar has been developed to address NASA's need for a high-performance, compact, and cost-effective velocity and altitude sensor onboard its landing vehicles. Future robotic and manned missions to solar system bodies require precise ground-relative velocity vector and altitude data to execute complex descent maneuvers and safe, soft landing at a pre-designated site. This lidar sensor, referred to as a Navigation Doppler Lidar (NDL), meets the required performance of the landing missions while complying with vehicle size, mass, and power constraints. Operating from up to four kilometers altitude, the NDL obtains velocity and range precision measurements reaching 2 cm/sec and 2 meters, respectively, dominated by the vehicle motion. Terrestrial aerial vehicles will also benefit from NDL data products as enhancement or replacement to GPS systems when GPS is unavailable or redundancy is needed. The NDL offers a viable option to aircraft navigation in areas where the GPS signal can be blocked or jammed by intentional or unintentional interference. The NDL transmits three laser beams at different pointing angles toward the ground to measure range and velocity along each beam using a frequency modulated continuous wave (FMCW) technique. The three line-of-sight measurements are then combined in order to determine the three components of the vehicle velocity vector and its altitude relative to the ground. This paper describes the performance and capabilities that the NDL demonstrated through extensive ground tests, helicopter flight tests, and onboard an autonomous rocket-powered test vehicle while operating in closedloop with a guidance, navigation, and control (GN and C) system.

Autonomous Collision-Free Navigation of Microvehicles in Complex and Dynamically Changing Environments.

Science.gov (United States)

Li, Tianlong; Chang, Xiaocong; Wu, Zhiguang; Li, Jinxing; Shao, Guangbin; Deng, Xinghong; Qiu, Jianbin; Guo, Bin; Zhang, Guangyu; He, Qiang; Li, Longqiu; Wang, Joseph

2017-09-26

Self-propelled micro- and nanoscale robots represent a rapidly emerging and fascinating robotics research area. However, designing autonomous and adaptive control systems for operating micro/nanorobotics in complex and dynamically changing environments, which is a highly demanding feature, is still an unmet challenge. Here we describe a smart microvehicle for precise autonomous navigation in complicated environments and traffic scenarios. The fully autonomous navigation system of the smart microvehicle is composed of a microscope-coupled CCD camera, an artificial intelligence planner, and a magnetic field generator. The microscope-coupled CCD camera provides real-time localization of the chemically powered Janus microsphere vehicle and environmental detection for path planning to generate optimal collision-free routes, while the moving direction of the microrobot toward a reference position is determined by the external electromagnetic torque. Real-time object detection offers adaptive path planning in response to dynamically changing environments. We demonstrate that the autonomous navigation system can guide the vehicle movement in complex patterns, in the presence of dynamically changing obstacles, and in complex biological environments. Such a navigation system for micro/nanoscale vehicles, relying on vision-based close-loop control and path planning, is highly promising for their autonomous operation in complex dynamic settings and unpredictable scenarios expected in a variety of realistic nanoscale scenarios.

SLS Navigation Model-Based Design Approach

Science.gov (United States)

Oliver, T. Emerson; Anzalone, Evan; Geohagan, Kevin; Bernard, Bill; Park, Thomas

2018-01-01

The SLS Program chose to implement a Model-based Design and Model-based Requirements approach for managing component design information and system requirements. This approach differs from previous large-scale design efforts at Marshall Space Flight Center where design documentation alone conveyed information required for vehicle design and analysis and where extensive requirements sets were used to scope and constrain the design. The SLS Navigation Team has been responsible for the Program-controlled Design Math Models (DMMs) which describe and represent the performance of the Inertial Navigation System (INS) and the Rate Gyro Assemblies (RGAs) used by Guidance, Navigation, and Controls (GN&C). The SLS Navigation Team is also responsible for the navigation algorithms. The navigation algorithms are delivered for implementation on the flight hardware as a DMM. For the SLS Block 1-B design, the additional GPS Receiver hardware is managed as a DMM at the vehicle design level. This paper provides a discussion of the processes and methods used to engineer, design, and coordinate engineering trades and performance assessments using SLS practices as applied to the GN&C system, with a particular focus on the Navigation components. These include composing system requirements, requirements verification, model development, model verification and validation, and modeling and analysis approaches. The Model-based Design and Requirements approach does not reduce the effort associated with the design process versus previous processes used at Marshall Space Flight Center. Instead, the approach takes advantage of overlap between the requirements development and management process, and the design and analysis process by efficiently combining the control (i.e. the requirement) and the design mechanisms. The design mechanism is the representation of the component behavior and performance in design and analysis tools. The focus in the early design process shifts from the development and

Vehicle logo recognition using multi-level fusion model

Science.gov (United States)

Ming, Wei; Xiao, Jianli

2018-04-01

Vehicle logo recognition plays an important role in manufacturer identification and vehicle recognition. This paper proposes a new vehicle logo recognition algorithm. It has a hierarchical framework, which consists of two fusion levels. At the first level, a feature fusion model is employed to map the original features to a higher dimension feature space. In this space, the vehicle logos become more recognizable. At the second level, a weighted voting strategy is proposed to promote the accuracy and the robustness of the recognition results. To evaluate the performance of the proposed algorithm, extensive experiments are performed, which demonstrate that the proposed algorithm can achieve high recognition accuracy and work robustly.

PERFORMANCE CHARACTERISTIC MEMS-BASED IMUs FOR UAVs NAVIGATION

Directory of Open Access Journals (Sweden)

H. A. Mohamed

2015-08-01

Full Text Available Accurate 3D reconstruction has become essential for non-traditional mapping applications such as urban planning, mining industry, environmental monitoring, navigation, surveillance, pipeline inspection, infrastructure monitoring, landslide hazard analysis, indoor localization, and military simulation. The needs of these applications cannot be satisfied by traditional mapping, which is based on dedicated data acquisition systems designed for mapping purposes. Recent advances in hardware and software development have made it possible to conduct accurate 3D mapping without using costly and high-end data acquisition systems. Low-cost digital cameras, laser scanners, and navigation systems can provide accurate mapping if they are properly integrated at the hardware and software levels. Unmanned Aerial Vehicles (UAVs are emerging as a mobile mapping platform that can provide additional economical and practical advantages. However, such economical and practical requirements need navigation systems that can provide uninterrupted navigation solution. Hence, testing the performance characteristics of Micro-Electro-Mechanical Systems (MEMS or low cost navigation sensors for various UAV applications is important research. This work focuses on studying the performance characteristics under different manoeuvres using inertial measurements integrated with single point positioning, Real-Time-Kinematic (RTK, and additional navigational aiding sensors. Furthermore, the performance of the inertial sensors is tested during Global Positioning System (GPS signal outage.

Performance Characteristic Mems-Based IMUs for UAVs Navigation

Science.gov (United States)

Mohamed, H. A.; Hansen, J. M.; Elhabiby, M. M.; El-Sheimy, N.; Sesay, A. B.

2015-08-01

Accurate 3D reconstruction has become essential for non-traditional mapping applications such as urban planning, mining industry, environmental monitoring, navigation, surveillance, pipeline inspection, infrastructure monitoring, landslide hazard analysis, indoor localization, and military simulation. The needs of these applications cannot be satisfied by traditional mapping, which is based on dedicated data acquisition systems designed for mapping purposes. Recent advances in hardware and software development have made it possible to conduct accurate 3D mapping without using costly and high-end data acquisition systems. Low-cost digital cameras, laser scanners, and navigation systems can provide accurate mapping if they are properly integrated at the hardware and software levels. Unmanned Aerial Vehicles (UAVs) are emerging as a mobile mapping platform that can provide additional economical and practical advantages. However, such economical and practical requirements need navigation systems that can provide uninterrupted navigation solution. Hence, testing the performance characteristics of Micro-Electro-Mechanical Systems (MEMS) or low cost navigation sensors for various UAV applications is important research. This work focuses on studying the performance characteristics under different manoeuvres using inertial measurements integrated with single point positioning, Real-Time-Kinematic (RTK), and additional navigational aiding sensors. Furthermore, the performance of the inertial sensors is tested during Global Positioning System (GPS) signal outage.

Survivability design for a hybrid underwater vehicle

Energy Technology Data Exchange (ETDEWEB)

Wang, Biao; Wu, Chao; Li, Xiang; Zhao, Qingkai; Ge, Tong [State Key Lab of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

2015-03-10

A novel hybrid underwater robotic vehicle (HROV) capable of working to the full ocean depth has been developed. The battery powered vehicle operates in two modes: operate as an untethered autonomous vehicle in autonomous underwater vehicle (AUV) mode and operate under remote control connected to the surface vessel by a lightweight, fiber optic tether in remotely operated vehicle (ROV) mode. Considering the hazardous underwater environment at the limiting depth and the hybrid operating modes, survivability has been placed on an equal level with the other design attributes of the HROV since the beginning of the project. This paper reports the survivability design elements for the HROV including basic vehicle design of integrated navigation and integrated communication, emergency recovery strategy, distributed architecture, redundant bus, dual battery package, emergency jettison system and self-repairing control system.

Survivability design for a hybrid underwater vehicle

International Nuclear Information System (INIS)

Wang, Biao; Wu, Chao; Li, Xiang; Zhao, Qingkai; Ge, Tong

2015-01-01

A novel hybrid underwater robotic vehicle (HROV) capable of working to the full ocean depth has been developed. The battery powered vehicle operates in two modes: operate as an untethered autonomous vehicle in autonomous underwater vehicle (AUV) mode and operate under remote control connected to the surface vessel by a lightweight, fiber optic tether in remotely operated vehicle (ROV) mode. Considering the hazardous underwater environment at the limiting depth and the hybrid operating modes, survivability has been placed on an equal level with the other design attributes of the HROV since the beginning of the project. This paper reports the survivability design elements for the HROV including basic vehicle design of integrated navigation and integrated communication, emergency recovery strategy, distributed architecture, redundant bus, dual battery package, emergency jettison system and self-repairing control system

An interactive physics-based unmanned ground vehicle simulator leveraging open source gaming technology: progress in the development and application of the virtual autonomous navigation environment (VANE) desktop

Science.gov (United States)

Rohde, Mitchell M.; Crawford, Justin; Toschlog, Matthew; Iagnemma, Karl D.; Kewlani, Guarav; Cummins, Christopher L.; Jones, Randolph A.; Horner, David A.

2009-05-01

It is widely recognized that simulation is pivotal to vehicle development, whether manned or unmanned. There are few dedicated choices, however, for those wishing to perform realistic, end-to-end simulations of unmanned ground vehicles (UGVs). The Virtual Autonomous Navigation Environment (VANE), under development by US Army Engineer Research and Development Center (ERDC), provides such capabilities but utilizes a High Performance Computing (HPC) Computational Testbed (CTB) and is not intended for on-line, real-time performance. A product of the VANE HPC research is a real-time desktop simulation application under development by the authors that provides a portal into the HPC environment as well as interaction with wider-scope semi-automated force simulations (e.g. OneSAF). This VANE desktop application, dubbed the Autonomous Navigation Virtual Environment Laboratory (ANVEL), enables analysis and testing of autonomous vehicle dynamics and terrain/obstacle interaction in real-time with the capability to interact within the HPC constructive geo-environmental CTB for high fidelity sensor evaluations. ANVEL leverages rigorous physics-based vehicle and vehicle-terrain interaction models in conjunction with high-quality, multimedia visualization techniques to form an intuitive, accurate engineering tool. The system provides an adaptable and customizable simulation platform that allows developers a controlled, repeatable testbed for advanced simulations. ANVEL leverages several key technologies not common to traditional engineering simulators, including techniques from the commercial video-game industry. These enable ANVEL to run on inexpensive commercial, off-the-shelf (COTS) hardware. In this paper, the authors describe key aspects of ANVEL and its development, as well as several initial applications of the system.

Autonomy Level Specification for Intelligent Autonomous Vehicles

Science.gov (United States)

2003-09-01

Autonomy Level Specification for Intelligent Autonomous Vehicles : Interim Progress Report Hui-Min Huang, Elena Messina, James Albus...Level Specification for Intelligent Autonomous Vehicles : Interim Progress Report 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

Experiments in teleoperator and autonomous control of space robotic vehicles

Science.gov (United States)

Alexander, Harold L.

1991-01-01

A program of research embracing teleoperator and automatic navigational control of freely flying satellite robots is presented. Current research goals include: (1) developing visual operator interfaces for improved vehicle teleoperation; (2) determining the effects of different visual interface system designs on operator performance; and (3) achieving autonomous vision-based vehicle navigation and control. This research program combines virtual-environment teleoperation studies and neutral-buoyancy experiments using a space-robot simulator vehicle currently under development. Visual-interface design options under investigation include monoscopic versus stereoscopic displays and cameras, helmet-mounted versus panel-mounted display monitors, head-tracking versus fixed or manually steerable remote cameras, and the provision of vehicle-fixed visual cues, or markers, in the remote scene for improved sensing of vehicle position, orientation, and motion.

The impact of navigation systems on traffic safety

NARCIS (Netherlands)

Rooijen, T. van; Vonk, T.

2007-01-01

This paper studies the impact of navigation systems on traffic safety in the Netherlands. This study consists of four analyses: a literature survey, a database analysis, a user survey and an instrumented vehicle study. The results of the four sections show that navigation systems have a positive

The impact of navigation systems on traffic safety

NARCIS (Netherlands)

Rooijen, T. van; Vonk, T.

2008-01-01

This paper studies the impact of navigation systems on traffic safety in the Netherlands. This study consists of four analyses: a literature survey, a database analysis, a user survey and an instrumented vehicle study. The results of the four sections show that navigation systems have a positive

Trajectory planning and tracking for autonomous vehicles navigation

OpenAIRE

Chebly , Alia

2017-01-01

In this thesis, the trajectory planning and the control of autonomous vehicles are addressed. As a first step, a multi-body modeling technique is used to develop a four wheeled vehicle planar model. This technique considers the vehicle as a robot consisting of articulated bodies. The geometric description of the vehicle system is derived using the modified Denavit Hartenberg parameterization and then the dynamic model of the vehicle is computed by applying a recursive method used in robotics,...

LiDAR Scan Matching Aided Inertial Navigation System in GNSS-Denied Environments.

Science.gov (United States)

Tang, Jian; Chen, Yuwei; Niu, Xiaoji; Wang, Li; Chen, Liang; Liu, Jingbin; Shi, Chuang; Hyyppä, Juha

2015-07-10

A new scan that matches an aided Inertial Navigation System (INS) with a low-cost LiDAR is proposed as an alternative to GNSS-based navigation systems in GNSS-degraded or -denied environments such as indoor areas, dense forests, or urban canyons. In these areas, INS-based Dead Reckoning (DR) and Simultaneous Localization and Mapping (SLAM) technologies are normally used to estimate positions as separate tools. However, there are critical implementation problems with each standalone system. The drift errors of velocity, position, and heading angles in an INS will accumulate over time, and on-line calibration is a must for sustaining positioning accuracy. SLAM performance is poor in featureless environments where the matching errors can significantly increase. Each standalone positioning method cannot offer a sustainable navigation solution with acceptable accuracy. This paper integrates two complementary technologies-INS and LiDAR SLAM-into one navigation frame with a loosely coupled Extended Kalman Filter (EKF) to use the advantages and overcome the drawbacks of each system to establish a stable long-term navigation process. Static and dynamic field tests were carried out with a self-developed Unmanned Ground Vehicle (UGV) platform-NAVIS. The results prove that the proposed approach can provide positioning accuracy at the centimetre level for long-term operations, even in a featureless indoor environment.

Multitarget Approaches to Robust Navigation

Data.gov (United States)

National Aeronautics and Space Administration — The performance, stability, and statistical consistency of a vehicle's navigation algorithm are vitally important to the success and safety of its mission....

Survey on In-vehicle Technology Use: Results and Findings

Directory of Open Access Journals (Sweden)

Raj K. Kamalanathsharma

2015-06-01

Full Text Available The use of advanced technology in automobiles has increased dramatically in the past couple of years. Driver-assisting gadgets such as navigation systems, advanced cruise control, collision avoidance systems, and other safety systems have moved down the ladder from luxury to more basic vehicles. Concurrently, auto manufacturers are also designing and testing driving algorithms that can assist with basic driving tasks, many of which are being continuously scrutinized by traffic safety agencies to ensure that these systems do not pose a safety hazard. The research presented in this paper brings a third perspective to in-vehicle technology by conducting a two-stage survey to collect public opinion on advanced in-vehicle technology. Approximately 64 percent of the respondents used a smartphone application to assist with their travel. The top-used applications were navigation and real-time traffic information systems. Among those who used smartphones during their commutes, the top-used applications were navigation and entertainment.

Ultra-Wideband Tracking System Design for Relative Navigation

Science.gov (United States)

Ni, Jianjun David; Arndt, Dickey; Bgo, Phong; Dekome, Kent; Dusl, John

2011-01-01

This presentation briefly discusses a design effort for a prototype ultra-wideband (UWB) time-difference-of-arrival (TDOA) tracking system that is currently under development at NASA Johnson Space Center (JSC). The system is being designed for use in localization and navigation of a rover in a GPS deprived environment for surface missions. In one application enabled by the UWB tracking, a robotic vehicle carrying equipments can autonomously follow a crewed rover from work site to work site such that resources can be carried from one landing mission to the next thereby saving up-mass. The UWB Systems Group at JSC has developed a UWB TDOA High Resolution Proximity Tracking System which can achieve sub-inch tracking accuracy of a target within the radius of the tracking baseline [1]. By extending the tracking capability beyond the radius of the tracking baseline, a tracking system is being designed to enable relative navigation between two vehicles for surface missions. A prototype UWB TDOA tracking system has been designed, implemented, tested, and proven feasible for relative navigation of robotic vehicles. Future work includes testing the system with the application code to increase the tracking update rate and evaluating the linear tracking baseline to improve the flexibility of antenna mounting on the following vehicle.

Improving Multisensor Positioning of Land Vehicles with Integrated Visual Odometry for Next-Generation Self-Driving Cars

Directory of Open Access Journals (Sweden)

Muhammed Tahsin Rahman

2018-01-01

Full Text Available For their complete realization, autonomous vehicles (AVs fundamentally rely on the Global Navigation Satellite System (GNSS to provide positioning and navigation information. However, in area such as urban cores, parking lots, and under dense foliage, which are all commonly frequented by AVs, GNSS signals suffer from blockage, interference, and multipath. These effects cause high levels of errors and long durations of service discontinuity that mar the performance of current systems. The prevalence of vision and low-cost inertial sensors provides an attractive opportunity to further increase the positioning and navigation accuracy in such GNSS-challenged environments. This paper presents enhancements to existing multisensor integration systems utilizing the inertial navigation system (INS to aid in Visual Odometry (VO outlier feature rejection. A scheme called Aided Visual Odometry (AVO is developed and integrated with a high performance mechanization architecture utilizing vehicle motion and orientation sensors. The resulting solution exhibits improved state covariance convergence and navigation accuracy, while reducing computational complexity. Experimental verification of the proposed solution is illustrated through three real road trajectories, over two different land vehicles, and using two low-cost inertial measurement units (IMUs.

Deep sea AUV navigation using multiple acoustic beacons

Science.gov (United States)

Ji, Da-xiong; Song, Wei; Zhao, Hong-yu; Liu, Jian

2016-04-01

Navigation is a critical requirement for the operation of Autonomous Underwater Vehicles (AUVs). To estimate the vehicle position, we present an algorithm using an extended Kalman filter (EKF) to integrate dead-reckoning position with acoustic ranges from multiple beacons pre-deployed in the operating environment. Owing to high latency, variable sound speed multipath transmissions and unreliability in acoustic measurements, outlier recognition techniques are proposed as well. The navigation algorithm has been tested by the recorded data of deep sea AUV during field operations in a variety of environments. Our results show the improved performance over prior techniques based on position computation.

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

Directory of Open Access Journals (Sweden)

Amedeo Rodi Vetrella

2016-12-01

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

Acoustic Communications and Navigation for Mobile Under-Ice Sensors

Science.gov (United States)

2017-02-04

contact below the ice. 15. SUBJECT TERMS Arctic Ocean , Undersea Workstations & Vehicles, Signal Processing, Navigation , Underwater Acoustics 16...Partan, Peter Koski, and Sandipa Singh, "Long Range Acoustic Communications and Navigation in the Arctic", Proc. IEEE/MTS Oceans Conf., Washington, DC...Oct. 2015. Freitag, L., P. Koski, A. Morozov, S. Singh, J. Partan, "Acoustic Communications and Navigation Under Arctic Ice", OCEANS , 2012

Remarks on the observability of single beacon underwater navigation

DEFF Research Database (Denmark)

Jouffroy, Jerome; Ross, Andrew

This paper contributes a simple and intuitive result in the analysis of underwater navigation using a single ranging beacon. This analysis should help with the design of small and lightweight underwater vehicles by reducing the amount of instrumentation required for accurate navigation. The concept...

Vehicle Detection for RCTA/ANS (Autonomous Navigation System)

Science.gov (United States)

Brennan, Shane; Bajracharya, Max; Matthies, Larry H.; Howard, Andrew B.

2012-01-01

Using a stereo camera pair, imagery is acquired and processed through the JPLV stereo processing pipeline. From this stereo data, large 3D blobs are found. These blobs are then described and classified by their shape to determine which are vehicles and which are not. Prior vehicle detection algorithms are either targeted to specific domains, such as following lead cars, or are intensity- based methods that involve learning typical vehicle appearances from a large corpus of training data. In order to detect vehicles, the JPL Vehicle Detection (JVD) algorithm goes through the following steps: 1. Take as input a left disparity image and left rectified image from JPLV stereo. 2. Project the disparity data onto a two-dimensional Cartesian map. 3. Perform some post-processing of the map built in the previous step in order to clean it up. 4. Take the processed map and find peaks. For each peak, grow it out into a map blob. These map blobs represent large, roughly vehicle-sized objects in the scene. 5. Take these map blobs and reject those that do not meet certain criteria. Build descriptors for the ones that remain. Pass these descriptors onto a classifier, which determines if the blob is a vehicle or not. The probability of detection is the probability that if a vehicle is present in the image, is visible, and un-occluded, then it will be detected by the JVD algorithm. In order to estimate this probability, eight sequences were ground-truthed from the RCTA (Robotics Collaborative Technology Alliances) program, totaling over 4,000 frames with 15 unique vehicles. Since these vehicles were observed at varying ranges, one is able to find the probability of detection as a function of range. At the time of this reporting, the JVD algorithm was tuned to perform best at cars seen from the front, rear, or either side, and perform poorly on vehicles seen from oblique angles.

Fully self-contained vision-aided navigation and landing of a micro air vehicle independent from external sensor inputs

Science.gov (United States)

Brockers, Roland; Susca, Sara; Zhu, David; Matthies, Larry

2012-06-01

Direct-lift micro air vehicles have important applications in reconnaissance. In order to conduct persistent surveillance in urban environments, it is essential that these systems can perform autonomous landing maneuvers on elevated surfaces that provide high vantage points without the help of any external sensor and with a fully contained on-board software solution. In this paper, we present a micro air vehicle that uses vision feedback from a single down looking camera to navigate autonomously and detect an elevated landing platform as a surrogate for a roof top. Our method requires no special preparation (labels or markers) of the landing location. Rather, leveraging the planar character of urban structure, the landing platform detection system uses a planar homography decomposition to detect landing targets and produce approach waypoints for autonomous landing. The vehicle control algorithm uses a Kalman filter based approach for pose estimation to fuse visual SLAM (PTAM) position estimates with IMU data to correct for high latency SLAM inputs and to increase the position estimate update rate in order to improve control stability. Scale recovery is achieved using inputs from a sonar altimeter. In experimental runs, we demonstrate a real-time implementation running on-board a micro aerial vehicle that is fully self-contained and independent from any external sensor information. With this method, the vehicle is able to search autonomously for a landing location and perform precision landing maneuvers on the detected targets.

Inertial navigation sensor integrated motion analysis for autonomous vehicle navigation

Science.gov (United States)

Roberts, Barry; Bhanu, Bir

1992-01-01

Recent work on INS integrated motion analysis is described. Results were obtained with a maximally passive system of obstacle detection (OD) for ground-based vehicles and rotorcraft. The OD approach involves motion analysis of imagery acquired by a passive sensor in the course of vehicle travel to generate range measurements to world points within the sensor FOV. INS data and scene analysis results are used to enhance interest point selection, the matching of the interest points, and the subsequent motion-based computations, tracking, and OD. The most important lesson learned from the research described here is that the incorporation of inertial data into the motion analysis program greatly improves the analysis and makes the process more robust.

LiDAR Scan Matching Aided Inertial Navigation System in GNSS-Denied Environments

Directory of Open Access Journals (Sweden)

Jian Tang

2015-07-01

Full Text Available A new scan that matches an aided Inertial Navigation System (INS with a low-cost LiDAR is proposed as an alternative to GNSS-based navigation systems in GNSS-degraded or -denied environments such as indoor areas, dense forests, or urban canyons. In these areas, INS-based Dead Reckoning (DR and Simultaneous Localization and Mapping (SLAM technologies are normally used to estimate positions as separate tools. However, there are critical implementation problems with each standalone system. The drift errors of velocity, position, and heading angles in an INS will accumulate over time, and on-line calibration is a must for sustaining positioning accuracy. SLAM performance is poor in featureless environments where the matching errors can significantly increase. Each standalone positioning method cannot offer a sustainable navigation solution with acceptable accuracy. This paper integrates two complementary technologies—INS and LiDAR SLAM—into one navigation frame with a loosely coupled Extended Kalman Filter (EKF to use the advantages and overcome the drawbacks of each system to establish a stable long-term navigation process. Static and dynamic field tests were carried out with a self-developed Unmanned Ground Vehicle (UGV platform—NAVIS. The results prove that the proposed approach can provide positioning accuracy at the centimetre level for long-term operations, even in a featureless indoor environment.

Electric Vehicle Interaction at the Electrical Circuit Level

Science.gov (United States)

2018-01-01

The objective of the Electric Vehicle Interaction at the Electrical Circuit Level project was to investigate electric vehicle (EV) charging as a means of mitigating transient over-voltages (TOVs) on the circuit level electric utility distribution gri...

A Novel 3D Multilateration Sensor Using Distributed Ultrasonic Beacons for Indoor Navigation

Directory of Open Access Journals (Sweden)

Rohan Kapoor

2016-10-01

Full Text Available Navigation and guidance systems are a critical part of any autonomous vehicle. In this paper, a novel sensor grid using 40 KHz ultrasonic transmitters is presented for adoption in indoor 3D positioning applications. In the proposed technique, a vehicle measures the arrival time of incoming ultrasonic signals and calculates the position without broadcasting to the grid. This system allows for conducting silent or covert operations and can also be used for the simultaneous navigation of a large number of vehicles. The transmitters and receivers employed are first described. Transmission lobe patterns and receiver directionality determine the geometry of transmitter clusters. Range and accuracy of measurements dictate the number of sensors required to navigate in a given volume. Laboratory experiments were performed in which a small array of transmitters was set up and the sensor system was tested for position accuracy. The prototype system is shown to have a 1-sigma position error of about 16 cm, with errors between 7 and 11 cm in the local horizontal coordinates. This research work provides foundations for the future development of ultrasonic navigation sensors for a variety of autonomous vehicle applications.

Establishment of high-precision navigation system in the Republic of Armenia

Directory of Open Access Journals (Sweden)

Manukyan Larisa Vladimirovna

2015-04-01

Full Text Available Medium-Earth orbit satellite systems make it possible to provide services on time coordination and navigation support for a wide range of consumers. At present, there are global navigation satellite systems GLONASS (Russia and GPS (USA. Users of these systems have an opportunity to determine their location accurately with the given characteristics of their navigation devices. In all developed countries the progress of geodesy and cartography is closely related to the implementation of advanced new technologies in both scientific and industrial areas. The introduction of new technologies and equipment in production is essential for the development of geodesy and cartography, bringing the existing geodetic networks and cartographic materials to modern condition. In the Republic of Armenia there are also plans on introduction of the systems for monitoring and management of vehicles for various purposes, as well as it is proposed to establish and implement an effective satellite navigation system to monitor and control traffic on the basis of advanced satellite technology. The article describes the basic steps to create the network of reference stations, GPS, aerial photography of much of the territory of Armenia, the creation of digital terrain model and the new maps by orthophotoplans. The analysis of the materials were carried out, on the basis of which in the Republic in 2015 a high-precision navigation system will be created. Due to the hard work of surveyors, cartographers and topographers the Republic was brought to European states level.

Vision-Based Leader Vehicle Trajectory Tracking for Multiple Agricultural Vehicles.

Science.gov (United States)

Zhang, Linhuan; Ahamed, Tofael; Zhang, Yan; Gao, Pengbo; Takigawa, Tomohiro

2016-04-22

The aim of this study was to design a navigation system composed of a human-controlled leader vehicle and a follower vehicle. The follower vehicle automatically tracks the leader vehicle. With such a system, a human driver can control two vehicles efficiently in agricultural operations. The tracking system was developed for the leader and the follower vehicle, and control of the follower was performed using a camera vision system. A stable and accurate monocular vision-based sensing system was designed, consisting of a camera and rectangular markers. Noise in the data acquisition was reduced by using the least-squares method. A feedback control algorithm was used to allow the follower vehicle to track the trajectory of the leader vehicle. A proportional-integral-derivative (PID) controller was introduced to maintain the required distance between the leader and the follower vehicle. Field experiments were conducted to evaluate the sensing and tracking performances of the leader-follower system while the leader vehicle was driven at an average speed of 0.3 m/s. In the case of linear trajectory tracking, the RMS errors were 6.5 cm, 8.9 cm and 16.4 cm for straight, turning and zigzag paths, respectively. Again, for parallel trajectory tracking, the root mean square (RMS) errors were found to be 7.1 cm, 14.6 cm and 14.0 cm for straight, turning and zigzag paths, respectively. The navigation performances indicated that the autonomous follower vehicle was able to follow the leader vehicle, and the tracking accuracy was found to be satisfactory. Therefore, the developed leader-follower system can be implemented for the harvesting of grains, using a combine as the leader and an unloader as the autonomous follower vehicle.

Hybrid extended particle filter (HEPF) for integrated inertial navigation and global positioning systems

International Nuclear Information System (INIS)

Aggarwal, Priyanka; Syed, Zainab; El-Sheimy, Naser

2009-01-01

Navigation includes the integration of methodologies and systems for estimating time-varying position, velocity and attitude of moving objects. Navigation incorporating the integrated inertial navigation system (INS) and global positioning system (GPS) generally requires extensive evaluations of nonlinear equations involving double integration. Currently, integrated navigation systems are commonly implemented using the extended Kalman filter (EKF). The EKF assumes a linearized process, measurement models and Gaussian noise distributions. These assumptions are unrealistic for highly nonlinear systems like land vehicle navigation and may cause filter divergence. A particle filter (PF) is developed to enhance integrated INS/GPS system performance as it can easily deal with nonlinearity and non-Gaussian noises. In this paper, a hybrid extended particle filter (HEPF) is developed as an alternative to the well-known EKF to achieve better navigation data accuracy for low-cost microelectromechanical system sensors. The results show that the HEPF performs better than the EKF during GPS outages, especially when simulated outages are located in periods with high vehicle dynamics

Terrain aided navigation for autonomous underwater vehicles with coarse maps

International Nuclear Information System (INIS)

Zhou, Ling; Cheng, Xianghong; Zhu, Yixian

2016-01-01

Terrain aided navigation (TAN) is a form of geophysical localization technique for autonomous underwater vehicles (AUVs) operating in GPS-denied environments. TAN performance on sensor-rich AUVs has been evaluated in sea trials. However, many challenges remain before TAN can be successfully implemented on sensor-limited AUVs, especially with coarse maps. To improve TAN performance over coarse maps, a Gaussian process (GP) is proposed for the modeling of bathymetric terrain and integrated into the particle filter (GP-PF). GP is applied to provide not only the bathymetric value prediction through learning a set of bathymetric data from coarse maps but also the variance of the prediction. As a measurement update, calculated on bathymetric deviation is performed through the PF to obtain absolute and bounded positioning accuracy. Through the analysis of TAN performance on experimental data for two different terrains with map resolutions of 10–50 m, both the ability of the proposed model to represent the actual bathymetric terrain with accuracy and the effect of the GP-PF for TAN on sensor-limited systems in suited terrain are demonstrated. The experiment results further verify that there is an inverse relationship between the coarseness of the map and the overall TAN accuracy in rough terrains, but there is hardly any relationship between them in relatively flat terrains. (paper)

A fuzzy logic based navigation for mobile robot

International Nuclear Information System (INIS)

Adel Ali S Al-Jumaily; Shamsudin M Amin; Mohamed Khalil

1998-01-01

The main issue of intelligent robot is how to reach its goal safely in real time when it moves in unknown environment. The navigational planning is becoming the central issue in development of real-time autonomous mobile robots. Behaviour based robots have been successful in reacting with dynamic environment but still there are some complexity and challenging problems. Fuzzy based behaviours present as powerful method to solve the real time reactive navigation problems in unknown environment. We shall classify the navigation generation methods, five some characteristics of these methods, explain why fuzzy logic is suitable for the navigation of mobile robot and automated guided vehicle, and describe a reactive navigation that is flexible to react through their behaviours to the change of the environment. Some simulation results will be presented to show the navigation of the robot. (Author)

Investigating impact of motor oil quality on vehicles engine induced noise level

Directory of Open Access Journals (Sweden)

I. Arefian

2015-09-01

Full Text Available Introduction: Vehicle engine id one of the main sources of noise which its level is influenced by various parameters. The aim of this study was to investigate the impact of motor oils quality before and after oil change on the variability of vehicle engine induced noise level. In this study it is tried to follow-up the efficacy of motor oil quality on engines sound level. Material and Method: First, engine noise of 94 vehicles were recorded for 30 seconds before and after oil change and all the vehicles technical information including mileage, type of motor oil, and type of vehicle were registered. Following, the recorded noises were calibrated in semi-anechoic chamber and the sound pressure levels were measured with A and C-weighting network and main octav bands, using a sound level meters. The obtained results analyzed using SPSS software version 17. Results: The effects of motor oil quality on different noise levels of engines were determined and a significant reduction in noise level of vehicles engine was observed. Investigation of the relationship between mileage and motor oil quality on various engines sound level manifested that vehicles with mileage ranged 100000-150000 miles had significant reduction in their sound pressure levels in comparison with other vehicles. Conclusion: The results revealed that engine oil is among factors reducing the vehicle engine induced noise level. Moreover, the engine oil type and the vehicle mileage are key variables which determine the impact of engine oil quality on reduction of the sound level of vehicles engine.

Fully autonomous navigation for the NASA cargo transfer vehicle

Science.gov (United States)

Wertz, James R.; Skulsky, E. David

1991-01-01

A great deal of attention has been paid to navigation during the close approach (less than or equal to 1 km) phase of spacecraft rendezvous. However, most spacecraft also require a navigation system which provides the necessary accuracy for placing both satellites within the range of the docking sensors. The Microcosm Autonomous Navigation System (MANS) is an on-board system which uses Earth-referenced attitude sensing hardware to provide precision orbit and attitude determination. The system is capable of functioning from LEO to GEO and beyond. Performance depends on the number of available sensors as well as mission geometry; however, extensive simulations have shown that MANS will provide 100 m to 400 m (3(sigma)) position accuracy and 0.03 to 0.07 deg (3(sigma)) attitude accuracy in low Earth orbit. The system is independent of any external source, including GPS. MANS is expected to have a significant impact on ground operations costs, mission definition and design, survivability, and the potential development of very low-cost, fully autonomous spacecraft.

Maneuverability Strategy for Assistive Vehicles Navigating within Confined Spaces

Directory of Open Access Journals (Sweden)

Fernando Auat Cheein

2011-08-01

Full Text Available In this work, a path planning strategy for both a car-like and a unicycle type assistive vehicles is presented. The assistive vehicles are confined to restricted environments. The path planning strategy uses the environment information to generate a kinematically plausible path to be followed by the vehicle. The environment information is provided by a SLAM (Simultaneous Localization and Mapping algorithm implemented on the vehicles. The map generated by the SLAM algorithm compensates the lack of sensor at the back of the vehicles' chassis. A Monte Carlo-based technique is used to find the optimum path given the SLAM information. A visual and user-friendly interface enhances the user-vehicle communication allowing him/her to select a desired position and orientation (pose that the vehicle should reach within the mapped environment. A trajectory controller drives the vehicle until it reaches a neighborhood of the desired pose. Several real-time experimental results within real environments are also shown herein.

GPS Navigation and Tracking Device

Directory of Open Access Journals (Sweden)

Yahya Salameh Khraisat

2011-10-01

Full Text Available Since the introduction of GPS Navigation systems in the marketplace, consumers and businesses have been coming up with innovative ways to use the technology in their everyday life. GPS Navigation and Tracking systems keep us from getting lost when we are in strange locations, they monitor children when they are away from home, keep track of business vehicles and can even let us know where a philandering partner is at all times. Because of this we attend to build a GPS tracking device to solve the mentioned problems. Our work consists of the GPS module that collects data from satellites and calculates the position information before transmitting them to the user’s PC (of Navigation system or observers (of Tracking System using wireless technology (GSM.

Development of an Autonomous Navigation Technology Test Vehicle

National Research Council Canada - National Science Library

Tobler, Chad K

2004-01-01

.... In order to continue these research activities at CIMAR, a new Kawasaki Mule All-Terrain Vehicle was chosen to be automated as a test-bed for the purpose of developing and testing autonomous vehicle technologies...

Metric Tracking of Launch Vehicles, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — NASA needs reliable, accurate navigation for launch vehicles and other missions. GPS is the best world-wide navigation system, but operates at low power making it...

Inertial Navigation System/Doppler Velocity Log (INS/DVL Fusion with Partial DVL Measurements

Directory of Open Access Journals (Sweden)

Asaf Tal

2017-02-01

Full Text Available The Technion autonomous underwater vehicle (TAUV is an ongoing project aiming to develop and produce a small AUV to carry on research missions, including payload dropping, and to demonstrate acoustic communication. Its navigation system is based on an inertial navigation system (INS aided by a Doppler velocity log (DVL, magnetometer, and pressure sensor (PS. In many INSs, such as the one used in TAUV, only the velocity vector (provided by the DVL can be used for aiding the INS, i.e., enabling only a loosely coupled integration approach. In cases of partial DVL measurements, such as failure to maintain bottom lock, the DVL cannot estimate the vehicle velocity. Thus, in partial DVL situations no velocity data can be integrated into the TAUV INS, and as a result its navigation solution will drift in time. To circumvent that problem, we propose a DVL-based vehicle velocity solution using the measured partial raw data of the DVL and additional information, thereby deriving an extended loosely coupled (ELC approach. The implementation of the ELC approach requires only software modification. In addition, we present the TAUV six degrees of freedom (6DOF simulation that includes all functional subsystems. Using this simulation, the proposed approach is evaluated and the benefit of using it is shown.

A mission executor for an autonomous underwater vehicle

Science.gov (United States)

Lee, Yuh-Jeng; Wilkinson, Paul

1991-01-01

The Naval Postgraduate School has been conducting research into the design and testing of an Autonomous Underwater Vehicle (AUV). One facet of this research is to incrementally design a software architecture and implement it in an advanced testbed, the AUV II. As part of the high level architecture, a Mission Executor is being constructed using CLIPS (C Language Integrated Production System) version 5.0. The Mission Executor is an expert system designed to oversee progress from the AUV launch point to a goal area and back to the origin. It is expected that the executor will make informed decisions about the mission, taking into account the navigational path, the vehicle subsystem health, and the sea environment, as well as the specific mission profile which is downloaded from an offboard mission planner. Heuristics for maneuvering, avoidance of uncharted obstacles, waypoint navigation, and reaction to emergencies (essentially the expert knowledge of a submarine captain) are required. Many of the vehicle subsystems are modeled as objects using the CLIPS Object Oriented Language (COOL) embedded in CLIPS 5.0. Also, truth maintenance is applied to the knowledge base to keep configurations updated.

Real-Time and High-Fidelity Simulation Environment for Autonomous Ground Vehicle Dynamics

Science.gov (United States)

Cameron, Jonathan; Myint, Steven; Kuo, Calvin; Jain, Abhi; Grip, Havard; Jayakumar, Paramsothy; Overholt, Jim

2013-01-01

This paper reports on a collaborative project between U.S. Army TARDEC and Jet Propulsion Laboratory (JPL) to develop a unmanned ground vehicle (UGV) simulation model using the ROAMS vehicle modeling framework. Besides modeling the physical suspension of the vehicle, the sensing and navigation of the HMMWV vehicle are simulated. Using models of urban and off-road environments, the HMMWV simulation was tested in several ways, including navigation in an urban environment with obstacle avoidance and the performance of a lane change maneuver.

International Symposium on Unmanned Aerial Vehicles

CERN Document Server

Oh, Paul; Piegl, Les

2009-01-01

Unmanned Aircraft Systems (UAS) have seen unprecedented levels of growth during the last decade in both military and civilian domains. It is anticipated that civilian applications will be dominant in the future, although there are still barriers to be overcome and technical challenges to be met. Integrating UAS into, for example, civilian space, navigation, autonomy, see-detect-and-avoid systems, smart designs, system integration, vision-based navigation and training, to name but a few areas, will be of prime importance in the near future. This special volume is the outcome of research presented at the International Symposium on Unmanned Aerial Vehicles, held in Orlando, Florida, USA, from June 23-25, 2008, and presents state-of-the-art findings on topics such as: UAS operations and integration into the national airspace system; UAS navigation and control; micro-, mini-, small UAVs; UAS simulation testbeds and frameworks; UAS research platforms and applications; UAS applications. This book aims at serving as ...

A Secure and Privacy-Preserving Navigation Scheme Using Spatial Crowdsourcing in Fog-Based VANETs

Science.gov (United States)

Wang, Lingling; Liu, Guozhu; Sun, Lijun

2017-01-01

Fog-based VANETs (Vehicular ad hoc networks) is a new paradigm of vehicular ad hoc networks with the advantages of both vehicular cloud and fog computing. Real-time navigation schemes based on fog-based VANETs can promote the scheme performance efficiently. In this paper, we propose a secure and privacy-preserving navigation scheme by using vehicular spatial crowdsourcing based on fog-based VANETs. Fog nodes are used to generate and release the crowdsourcing tasks, and cooperatively find the optimal route according to the real-time traffic information collected by vehicles in their coverage areas. Meanwhile, the vehicle performing the crowdsourcing task can get a reasonable reward. The querying vehicle can retrieve the navigation results from each fog node successively when entering its coverage area, and follow the optimal route to the next fog node until it reaches the desired destination. Our scheme fulfills the security and privacy requirements of authentication, confidentiality and conditional privacy preservation. Some cryptographic primitives, including the Elgamal encryption algorithm, AES, randomized anonymous credentials and group signatures, are adopted to achieve this goal. Finally, we analyze the security and the efficiency of the proposed scheme. PMID:28338620

A Secure and Privacy-Preserving Navigation Scheme Using Spatial Crowdsourcing in Fog-Based VANETs.

Science.gov (United States)

Wang, Lingling; Liu, Guozhu; Sun, Lijun

2017-03-24

Fog-based VANETs (Vehicular ad hoc networks) is a new paradigm of vehicular ad hoc networks with the advantages of both vehicular cloud and fog computing. Real-time navigation schemes based on fog-based VANETs can promote the scheme performance efficiently. In this paper, we propose a secure and privacy-preserving navigation scheme by using vehicular spatial crowdsourcing based on fog-based VANETs. Fog nodes are used to generate and release the crowdsourcing tasks, and cooperatively find the optimal route according to the real-time traffic information collected by vehicles in their coverage areas. Meanwhile, the vehicle performing the crowdsourcing task can get a reasonable reward. The querying vehicle can retrieve the navigation results from each fog node successively when entering its coverage area, and follow the optimal route to the next fog node until it reaches the desired destination. Our scheme fulfills the security and privacy requirements of authentication, confidentiality and conditional privacy preservation. Some cryptographic primitives, including the Elgamal encryption algorithm, AES, randomized anonymous credentials and group signatures, are adopted to achieve this goal. Finally, we analyze the security and the efficiency of the proposed scheme.

Online Aerial Terrain Mapping for Ground Robot Navigation

Directory of Open Access Journals (Sweden)

John Peterson

2018-02-01

Full Text Available This work presents a collaborative unmanned aerial and ground vehicle system which utilizes the aerial vehicle’s overhead view to inform the ground vehicle’s path planning in real time. The aerial vehicle acquires imagery which is assembled into a orthomosaic and then classified. These terrain classes are used to estimate relative navigation costs for the ground vehicle so energy-efficient paths may be generated and then executed. The two vehicles are registered in a common coordinate frame using a real-time kinematic global positioning system (RTK GPS and all image processing is performed onboard the unmanned aerial vehicle, which minimizes the data exchanged between the vehicles. This paper describes the architecture of the system and quantifies the registration errors between the vehicles.

Vision Based Navigation for Autonomous Cooperative Docking of CubeSats

Science.gov (United States)

Pirat, Camille; Ankersen, Finn; Walker, Roger; Gass, Volker

2018-05-01

A realistic rendezvous and docking navigation solution applicable to CubeSats is investigated. The scalability analysis of the ESA Autonomous Transfer Vehicle Guidance, Navigation & Control (GNC) performances and the Russian docking system, shows that the docking of two CubeSats would require a lateral control performance of the order of 1 cm. Line of sight constraints and multipath effects affecting Global Navigation Satellite System (GNSS) measurements in close proximity prevent the use of this sensor for the final approach. This consideration and the high control accuracy requirement led to the use of vision sensors for the final 10 m of the rendezvous and docking sequence. A single monocular camera on the chaser satellite and various sets of Light-Emitting Diodes (LEDs) on the target vehicle ensure the observability of the system throughout the approach trajectory. The simple and novel formulation of the measurement equations allows differentiating unambiguously rotations from translations between the target and chaser docking port and allows a navigation performance better than 1 mm at docking. Furthermore, the non-linear measurement equations can be solved in order to provide an analytic navigation solution. This solution can be used to monitor the navigation filter solution and ensure its stability, adding an extra layer of robustness for autonomous rendezvous and docking. The navigation filter initialization is addressed in detail. The proposed method is able to differentiate LEDs signals from Sun reflections as demonstrated by experimental data. The navigation filter uses a comprehensive linearised coupled rotation/translation dynamics, describing the chaser to target docking port motion. The handover, between GNSS and vision sensor measurements, is assessed. The performances of the navigation function along the approach trajectory is discussed.

In-vehicle information system functions

Energy Technology Data Exchange (ETDEWEB)

Tufano, D.R.; Spelt, P.F.; Knee, H.E.

1997-04-01

This paper describes the functional requirement for an In-Vehicle Information System (IVIS), which will manage and display all driving-related information from many sources. There are numerous information systems currently being fielded or developed (e.g., routing and navigation, collision avoidance). However, without a logical integration of all of the possible on-board information, there is a potential for overwhelming the driver. The system described in this paper will filter and prioritize information across all sources, and present it to the driver in a timely manner, within a unified interface. To do this, IVIS will perform three general functions: (1) interact with other, on-board information subsystems and the vehicle; (2) manage the information by filtering, prioritizing, and integrating it; and (3) interact with the driver, both in terms of displaying information to the driver and allowing the driver to input requests, goals and preferences. The functional requirements described in this paper have either been derived from these three high-level functions or are directly mandated by the overriding requirements for modularity and flexibility. IVIS will have to be able to accommodate different types of information subsystems, of varying level of sophistication. The system will also have to meet the diverse needs of different types of drivers (private, commercial, transit), who may have very different levels of expertise in using information systems.

Passivity-based model predictive control for mobile vehicle motion planning

CERN Document Server

Tahirovic, Adnan

2013-01-01

Passivity-based Model Predictive Control for Mobile Vehicle Navigation represents a complete theoretical approach to the adoption of passivity-based model predictive control (MPC) for autonomous vehicle navigation in both indoor and outdoor environments. The brief also introduces analysis of the worst-case scenario that might occur during the task execution. Some of the questions answered in the text include: • how to use an MPC optimization framework for the mobile vehicle navigation approach; • how to guarantee safe task completion even in complex environments including obstacle avoidance and sideslip and rollover avoidance; and  • what to expect in the worst-case scenario in which the roughness of the terrain leads the algorithm to generate the longest possible path to the goal. The passivity-based MPC approach provides a framework in which a wide range of complex vehicles can be accommodated to obtain a safer and more realizable tool during the path-planning stage. During task execution, the optimi...

Contour Tracking Control for the REMUS Autonomous Underwater Vehicle

National Research Council Canada - National Science Library

Van Reet, Alan R

2005-01-01

In the interest of enhancing the capabilities of autonomous underwater vehicles used in US Naval Operations, controlling vehicle position to follow depth contours presents exciting potential for navigation...

Absolute Navigation Performance of the Orion Exploration Fight Test 1

Science.gov (United States)

Zanetti, Renato; Holt, Greg; Gay, Robert; D'Souza, Christopher; Sud, Jastesh

2016-01-01

Launched in December 2014 atop a Delta IV Heavy from the Kennedy Space Center, the Orion vehicle's Exploration Flight Test-1 (EFT-1) successfully completed the objective to stress the system by placing the un-crewed vehicle on a high-energy parabolic trajectory replicating conditions similar to those that would be experienced when returning from an asteroid or a lunar mission. Unique challenges associated with designing the navigation system for EFT-1 are presented with an emphasis on how redundancy and robustness influenced the architecture. Two Inertial Measurement Units (IMUs), one GPS receiver and three barometric altimeters (BALTs) comprise the navigation sensor suite. The sensor data is multiplexed using conventional integration techniques and the state estimate is refined by the GPS pseudorange and deltarange measurements in an Extended Kalman Filter (EKF) that employs UDU factorization. The performance of the navigation system during flight is presented to substantiate the design.

Fast reconstruction of an unmanned engineering vehicle and its application to carrying rocket

Directory of Open Access Journals (Sweden)

Jun Qian

2014-04-01

Full Text Available Engineering vehicle is widely used as a huge moving platform for transporting heavy goods. However, traditional human operations have a great influence on the steady movement of the vehicle. In this Letter, a fast reconstruction process of an unmanned engineering vehicle is carried out. By adding a higher-level controller and two two-dimensional laser scanners on the moving platform, the vehicle could perceive the surrounding environment and locate its pose according to extended Kalman filter. Then, a closed-loop control system is formed by communicating with the on-board lower-level controller. To verify the performance of automatic control system, the unmanned vehicle is automatically navigated when carrying a rocket towards a launcher in a launch site. The experimental results show that the vehicle could align with the launcher smoothly and safely within a small lateral deviation of 1 cm. This fast reconstruction presents an efficient way of rebuilding low-cost unmanned special vehicles and other automatic moving platforms.

Expected Navigation Flight Performance for the Magnetospheric Multiscale (MMS) Mission

Science.gov (United States)

Olson, Corwin; Wright, Cinnamon; Long, Anne

2012-01-01

The Magnetospheric Multiscale (MMS) mission consists of four formation-flying spacecraft placed in highly eccentric elliptical orbits about the Earth. The primary scientific mission objective is to study magnetic reconnection within the Earth s magnetosphere. The baseline navigation concept is the independent estimation of each spacecraft state using GPS pseudorange measurements (referenced to an onboard Ultra Stable Oscillator) and accelerometer measurements during maneuvers. State estimation for the MMS spacecraft is performed onboard each vehicle using the Goddard Enhanced Onboard Navigation System, which is embedded in the Navigator GPS receiver. This paper describes the latest efforts to characterize expected navigation flight performance using upgraded simulation models derived from recent analyses.

Doppler lidar sensor for precision navigation in GPS-deprived environment

Science.gov (United States)

Amzajerdian, F.; Pierrottet, D. F.; Hines, G. D.; Petway, L. B.; Barnes, B. W.

2013-05-01

Landing mission concepts that are being developed for exploration of solar system bodies are increasingly ambitious in their implementations and objectives. Most of these missions require accurate position and velocity data during their descent phase in order to ensure safe, soft landing at the pre-designated sites. Data from the vehicle's Inertial Measurement Unit will not be sufficient due to significant drift error after extended travel time in space. Therefore, an onboard sensor is required to provide the necessary data for landing in the GPS-deprived environment of space. For this reason, NASA Langley Research Center has been developing an advanced Doppler lidar sensor capable of providing accurate and reliable data suitable for operation in the highly constrained environment of space. The Doppler lidar transmits three laser beams in different directions toward the ground. The signal from each beam provides the platform velocity and range to the ground along the laser line-of-sight (LOS). The six LOS measurements are then combined in order to determine the three components of the vehicle velocity vector, and to accurately measure altitude and attitude angles relative to the local ground. These measurements are used by an autonomous Guidance, Navigation, and Control system to accurately navigate the vehicle from a few kilometers above the ground to the designated location and to execute a gentle touchdown. A prototype version of our lidar sensor has been completed for a closed-loop demonstration onboard a rocket-powered terrestrial free-flyer vehicle.

Navigation and Alignment Aids Concept of Operations and Supplemental Design Information. Revision A

Science.gov (United States)

Kelly, Sean M.; Cryan, Scott P.

2016-01-01

The IDSS Navigation and Alignment Aids Concept of Operations and Supplemental Design Information document provides supplemental information to the IDSS IDD. The guide provides insight into the navigation and alignment aids design, and how those aids can be utilized by incoming vehicles for proximity operations and docking. The navigation aids are paramount to successful docking.

An SINS/GNSS Ground Vehicle Gravimetry Test Based on SGA-WZ02

Directory of Open Access Journals (Sweden)

Ruihang Yu

2015-09-01

Full Text Available In March 2015, a ground vehicle gravimetry test was implemented in eastern Changsha to assess the repeatability and accuracy of ground vehicle SINS/GNSS gravimeter—SGA-WZ02. The gravity system developed by NUDT consisted of a Strapdown Inertial Navigation System (SINS, a Global Navigation Satellite System (GNSS remote station on test vehicle, a GNSS static master station on the ground, and a data logging subsystem. A south-north profile of 35 km along the highway in eastern Changsha was chosen and four repeated available measure lines were obtained. The average speed of a vehicle is 40 km/h. To assess the external ground gravity disturbances, precise ground gravity data was built by CG-5 precise gravimeter as the reference. Under relative smooth conditions, internal accuracy among repeated lines shows an average agreement at the level of 1.86 mGal for half wavelengths about 1.1 km, and 1.22 mGal for 1.7 km. The root-mean-square (RMS of difference between calculated gravity data and reference data is about 2.27 mGal/1.1 km, and 1.74 mGal/1.7 km. Not all of the noises caused by vehicle itself and experiments environments were eliminated in the primary results. By means of selecting reasonable filters and improving the GNSS observation conditions, further developments in ground vehicle gravimetry are promising.

IMPROVING CAR NAVIGATION WITH A VISION-BASED SYSTEM

Directory of Open Access Journals (Sweden)

H. Kim

2015-08-01

Full Text Available The real-time acquisition of the accurate positions is very important for the proper operations of driver assistance systems or autonomous vehicles. Since the current systems mostly depend on a GPS and map-matching technique, they show poor and unreliable performance in blockage and weak areas of GPS signals. In this study, we propose a vision oriented car navigation method based on sensor fusion with a GPS and in-vehicle sensors. We employed a single photo resection process to derive the position and attitude of the camera and thus those of the car. This image georeferencing results are combined with other sensory data under the sensor fusion framework for more accurate estimation of the positions using an extended Kalman filter. The proposed system estimated the positions with an accuracy of 15 m although GPS signals are not available at all during the entire test drive of 15 minutes. The proposed vision based system can be effectively utilized for the low-cost but high-accurate and reliable navigation systems required for intelligent or autonomous vehicles.

Improving Car Navigation with a Vision-Based System

Science.gov (United States)

Kim, H.; Choi, K.; Lee, I.

2015-08-01

The real-time acquisition of the accurate positions is very important for the proper operations of driver assistance systems or autonomous vehicles. Since the current systems mostly depend on a GPS and map-matching technique, they show poor and unreliable performance in blockage and weak areas of GPS signals. In this study, we propose a vision oriented car navigation method based on sensor fusion with a GPS and in-vehicle sensors. We employed a single photo resection process to derive the position and attitude of the camera and thus those of the car. This image georeferencing results are combined with other sensory data under the sensor fusion framework for more accurate estimation of the positions using an extended Kalman filter. The proposed system estimated the positions with an accuracy of 15 m although GPS signals are not available at all during the entire test drive of 15 minutes. The proposed vision based system can be effectively utilized for the low-cost but high-accurate and reliable navigation systems required for intelligent or autonomous vehicles.

Vegetation Versus Man-Made Object Detection from Imagery for Unmanned Vehicles in Off-Road Environments

Science.gov (United States)

2013-05-01

saliency, natural scene statistics 1. INTRODUCTION Research into the area of autonomous navigation for unmanned ground vehicles (UGV) has accelerated in...recent years. This is partly due to the success of programs such as the DARPA Grand Challenge1 and the dream of driverless cars ,2 but is also due to the...NOTES 14. ABSTRACT There have been several major advances in autonomous navigation for unmanned ground vehicles in controlled urban environments in

Autonomous vehicles: from paradigms to technology

Science.gov (United States)

Ionita, Silviu

2017-10-01

Mobility is a basic necessity of contemporary society and it is a key factor in global economic development. The basic requirements for the transport of people and goods are: safety and duration of travel, but also a number of additional criteria are very important: energy saving, pollution, passenger comfort. Due to advances in hardware and software, automation has penetrated massively in transport systems both on infrastructure and on vehicles, but man is still the key element in vehicle driving. However, the classic concept of ‘human-in-the-loop’ in terms of ‘hands on’ in driving the cars is competing aside from the self-driving startups working towards so-called ‘Level 4 autonomy’, which is defined as “a self-driving system that does not requires human intervention in most scenarios”. In this paper, a conceptual synthesis of the autonomous vehicle issue is made in connection with the artificial intelligence paradigm. It presents a classification of the tasks that take place during the driving of the vehicle and its modeling from the perspective of traditional control engineering and artificial intelligence. The issue of autonomous vehicle management is addressed on three levels: navigation, movement in traffic, respectively effective maneuver and vehicle dynamics control. Each level is then described in terms of specific tasks, such as: route selection, planning and reconfiguration, recognition of traffic signs and reaction to signaling and traffic events, as well as control of effective speed, distance and direction. The approach will lead to a better understanding of the way technology is moving when talking about autonomous cars, smart/intelligent cars or intelligent transport systems. Keywords: self-driving vehicle, artificial intelligence, deep learning, intelligent transport systems.

Autonomous intelligent vehicles theory, algorithms, and implementation

CERN Document Server

Cheng, Hong

2011-01-01

Here is the latest on intelligent vehicles, covering object and obstacle detection and recognition and vehicle motion control. Includes a navigation approach using global views; introduces algorithms for lateral and longitudinal motion control and more.

Experimental Semiautonomous Vehicle

Science.gov (United States)

Wilcox, Brian H.; Mishkin, Andrew H.; Litwin, Todd E.; Matthies, Larry H.; Cooper, Brian K.; Nguyen, Tam T.; Gat, Erann; Gennery, Donald B.; Firby, Robert J.; Miller, David P.;

A Novel Online Data-Driven Algorithm for Detecting UAV Navigation Sensor Faults

OpenAIRE

Rui Sun; Qi Cheng; Guanyu Wang; Washington Yotto Ochieng

2017-01-01

The use of Unmanned Aerial Vehicles (UAVs) has increased significantly in recent years. On-board integrated navigation sensors are a key component of UAVs’ flight control systems and are essential for flight safety. In order to ensure flight safety, timely and effective navigation sensor fault detection capability is required. In this paper, a novel data-driven Adaptive Neuron Fuzzy Inference System (ANFIS)-based approach is presented for the detection of on-board navigation sensor faults in ...

Low computation vision-based navigation for a Martian rover

Science.gov (United States)

Gavin, Andrew S.; Brooks, Rodney A.

1994-01-01

Construction and design details of the Mobot Vision System, a small, self-contained, mobile vision system, are presented. This system uses the view from the top of a small, roving, robotic vehicle to supply data that is processed in real-time to safely navigate the surface of Mars. A simple, low-computation algorithm for constructing a 3-D navigational map of the Martian environment to be used by the rover is discussed.

Indoor Semantic Modelling for Routing: The Two-Level Routing Approach for Indoor Navigation

Directory of Open Access Journals (Sweden)

Liu Liu

2017-11-01

Full Text Available Humans perform many activities indoors and they show a growing need for indoor navigation, especially in unfamiliar buildings such as airports, museums and hospitals. Complexity of such buildings poses many challenges for building managers and visitors. Indoor navigation services play an important role in supporting these indoor activities. Indoor navigation covers extensive topics such as: 1 indoor positioning and localization; 2 indoor space representation for navigation model generation; 3 indoor routing computation; 4 human wayfinding behaviours; and 5 indoor guidance (e.g., textual directories. So far, a large number of studies of pedestrian indoor navigation have presented diverse navigation models and routing algorithms/methods. However, the major challenge is rarely referred to: how to represent the complex indoor environment for pedestrians and conduct routing according to the different roles and sizes of users. Such complex buildings contain irregular shapes, large open spaces, complicated obstacles and different types of passages. A navigation model can be very complicated if the indoors are accurately represented. Although most research demonstrates feasible indoor navigation models and related routing methods in regular buildings, the focus is still on a general navigation model for pedestrians who are simplified as circles. In fact, pedestrians represent different sizes, motion abilities and preferences (e.g., described in user profiles, which should be reflected in navigation models and be considered for indoor routing (e.g., relevant Spaces of Interest and Points of Interest. In order to address this challenge, this thesis proposes an innovative indoor modelling and routing approach – two-level routing. It specially targets the case of routing in complex buildings for distinct users. The conceptual (first level uses general free indoor spaces: this is represented by the logical network whose nodes represent the spaces and edges

A GPS inspired Terrain Referenced Navigation algorithm

NARCIS (Netherlands)

Vaman, D.

2014-01-01

Terrain Referenced Navigation (TRN) refers to a form of localization in which measurements of distances to the terrain surface are matched with a digital elevation map allowing a vehicle to estimate its own position within the map. The main goal of this dissertation is to improve TRN performance

Obstacle detection system for underground mining vehicles

Energy Technology Data Exchange (ETDEWEB)

Cohen, P.; Polotski, V.; Piotte, M.; Melamed, F. [Ecole Polytechnique de Montreal, Montreal, PQ (Canada)

1998-01-01

A device for detecting obstacles by autonomous vehicles navigating in mine drifts is described. The device is based upon structured lighting and the extraction of relevant features from images of obstacles. The system uses image profile changes, ground and wall irregularities, disturbances of the vehicle`s trajectory, and impaired visibility to detect obstacles, rather than explicit three-dimensional scene reconstruction. 7 refs., 5 figs.

Effects of Mid-Level Ethanol Blends on Conventional Vehicle Emissions

Energy Technology Data Exchange (ETDEWEB)

Knoll, K.; West, B.; Huff, S.; Thomas, J.; Orban, J.; Cooper, C.

2010-06-01

Tests were conducted in 2008 on 16 late-model conventional vehicles (1999-2007) to determine short-term effects of mid-level ethanol blends on performance and emissions. Vehicle odometer readings ranged from 10,000 to 100,000 miles, and all vehicles conformed to federal emissions requirements for their federal certification level. The LA92 drive cycle, also known as the Unified Cycle, was used for testing because it more accurately represents real-world acceleration rates and speeds than the Federal Test Procedure. Test fuels were splash-blends of up to 20 volume percent ethanol with federal certification gasoline. Both regulated and unregulated air-toxic emissions were measured. For the 16-vehicle fleet, increasing ethanol content resulted in reductions in average composite emissions of both nonmethane hydrocarbons and carbon monoxide and increases in average emissions of ethanol and aldehydes.

Vision enhanced navigation for unmanned systems

Science.gov (United States)

Wampler, Brandon Loy

A vision based simultaneous localization and mapping (SLAM) algorithm is evaluated for use on unmanned systems. SLAM is a technique used by a vehicle to build a map of an environment while concurrently keeping track of its location within the map, without a priori knowledge. The work in this thesis is focused on using SLAM as a navigation solution when global positioning system (GPS) service is degraded or temporarily unavailable. Previous work on unmanned systems that lead up to the determination that a better navigation solution than GPS alone is first presented. This previous work includes control of unmanned systems, simulation, and unmanned vehicle hardware testing. The proposed SLAM algorithm follows the work originally developed by Davidson et al. in which they dub their algorithm MonoSLAM [1--4]. A new approach using the Pyramidal Lucas-Kanade feature tracking algorithm from Intel's OpenCV (open computer vision) library is presented as a means of keeping correct landmark correspondences as the vehicle moves through the scene. Though this landmark tracking method is unusable for long term SLAM due to its inability to recognize revisited landmarks, as opposed to the Scale Invariant Feature Transform (SIFT) and Speeded Up Robust Features (SURF), its computational efficiency makes it a good candidate for short term navigation between GPS position updates. Additional sensor information is then considered by fusing INS and GPS information into the SLAM filter. The SLAM system, in its vision only and vision/IMU form, is tested on a table top, in an open room, and finally in an outdoor environment. For the outdoor environment, a form of the slam algorithm that fuses vision, IMU, and GPS information is tested. The proposed SLAM algorithm, and its several forms, are implemented in C++ using an Extended Kalman Filter (EKF). Experiments utilizing a live video feed from a webcam are performed. The different forms of the filter are compared and conclusions are made on

Monocular Vision SLAM for Indoor Aerial Vehicles

Directory of Open Access Journals (Sweden)

Koray Çelik

2013-01-01

Full Text Available This paper presents a novel indoor navigation and ranging strategy via monocular camera. By exploiting the architectural orthogonality of the indoor environments, we introduce a new method to estimate range and vehicle states from a monocular camera for vision-based SLAM. The navigation strategy assumes an indoor or indoor-like manmade environment whose layout is previously unknown, GPS-denied, representable via energy based feature points, and straight architectural lines. We experimentally validate the proposed algorithms on a fully self-contained microaerial vehicle (MAV with sophisticated on-board image processing and SLAM capabilities. Building and enabling such a small aerial vehicle to fly in tight corridors is a significant technological challenge, especially in the absence of GPS signals and with limited sensing options. Experimental results show that the system is only limited by the capabilities of the camera and environmental entropy.

Visual Odometry and Place Recognition Fusion for Vehicle Position Tracking in Urban Environments.

Science.gov (United States)

Ouerghi, Safa; Boutteau, Rémi; Savatier, Xavier; Tlili, Fethi

2018-03-22

In this paper, we address the problem of vehicle localization in urban environments. We rely on visual odometry, calculating the incremental motion, to track the position of the vehicle and on place recognition to correct the accumulated drift of visual odometry, whenever a location is recognized. The algorithm used as a place recognition module is SeqSLAM, addressing challenging environments and achieving quite remarkable results. Specifically, we perform the long-term navigation of a vehicle based on the fusion of visual odometry and SeqSLAM. The template library for this latter is created online using navigation information from the visual odometry module. That is, when a location is recognized, the corresponding information is used as an observation of the filter. The fusion is done using the EKF and the UKF, the well-known nonlinear state estimation methods, to assess the superior alternative. The algorithm is evaluated using the KITTI dataset and the results show the reduction of the navigation errors by loop-closure detection. The overall position error of visual odometery with SeqSLAM is 0.22% of the trajectory, which is much smaller than the navigation errors of visual odometery alone 0.45%. In addition, despite the superiority of the UKF in a variety of estimation problems, our results indicate that the UKF performs as efficiently as the EKF at the expense of an additional computational overhead. This leads to the conclusion that the EKF is a better choice for fusing visual odometry and SeqSlam in a long-term navigation context.

Vehicle systems and payload requirements evaluation. [computer programs for identifying launch vehicle system requirements

Science.gov (United States)

Rea, F. G.; Pittenger, J. L.; Conlon, R. J.; Allen, J. D.

1975-01-01

Techniques developed for identifying launch vehicle system requirements for NASA automated space missions are discussed. Emphasis is placed on development of computer programs and investigation of astrionics for OSS missions and Scout. The Earth Orbit Mission Program - 1 which performs linear error analysis of launch vehicle dispersions for both vehicle and navigation system factors is described along with the Interactive Graphic Orbit Selection program which allows the user to select orbits which satisfy mission requirements and to evaluate the necessary injection accuracy.

Usability engineering of "In Vehicle Information Systems" with multi-tasking GOMS

OpenAIRE

Urbas, L.; Leuchter, S.

2008-01-01

The developments in vehicle electronics and new services are supposed to promise more convenience in driving. The offers and ideas range from vehicle-related installations, such as accident alert, petrol station assistance, dynamic navigation and travel guide, to communication and entertainment services. There is one central design problem that is essential for achieving the main objective "safe motor vehicle driving", i.e. the use of the new service must not unduly distract the driver. In th...

Cascading a systolic array and a feedforward neural network for navigation and obstacle avoidance using potential fields

Science.gov (United States)

Plumer, Edward S.

1991-01-01

A technique is developed for vehicle navigation and control in the presence of obstacles. A potential function was devised that peaks at the surface of obstacles and has its minimum at the proper vehicle destination. This function is computed using a systolic array and is guaranteed not to have local minima. A feedfoward neural network is then used to control the steering of the vehicle using local potential field information. In this case, the vehicle is a trailer truck backing up. Previous work has demonstrated the capability of a neural network to control steering of such a trailer truck backing to a loading platform, but without obstacles. Now, the neural network was able to learn to navigate a trailer truck around obstacles while backing toward its destination. The network is trained in an obstacle free space to follow the negative gradient of the field, after which the network is able to control and navigate the truck to its target destination in a space of obstacles which may be stationary or movable.

Context-Aided Sensor Fusion for Enhanced Urban Navigation

Science.gov (United States)

Martí, Enrique David; Martín, David; García, Jesús; de la Escalera, Arturo; Molina, José Manuel; Armingol, José María

2012-01-01

The deployment of Intelligent Vehicles in urban environments requires reliable estimation of positioning for urban navigation. The inherent complexity of this kind of environments fosters the development of novel systems which should provide reliable and precise solutions to the vehicle. This article details an advanced GNSS/IMU fusion system based on a context-aided Unscented Kalman filter for navigation in urban conditions. The constrained non-linear filter is here conditioned by a contextual knowledge module which reasons about sensor quality and driving context in order to adapt it to the situation, while at the same time it carries out a continuous estimation and correction of INS drift errors. An exhaustive analysis has been carried out with available data in order to characterize the behavior of available sensors and take it into account in the developed solution. The performance is then analyzed with an extensive dataset containing representative situations. The proposed solution suits the use of fusion algorithms for deploying Intelligent Transport Systems in urban environments. PMID:23223080

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.

Enabling Persistent Autonomy for Underwater Gliders with Ocean Model Predictions and Terrain Based Navigation

Directory of Open Access Journals (Sweden)

Andrew eStuntz

2016-04-01

Full Text Available Effective study of ocean processes requires sampling over the duration of long (weeks to months oscillation patterns. Such sampling requires persistent, autonomous underwater vehicles, that have a similarly long deployment duration. The spatiotemporal dynamics of the ocean environment, coupled with limited communication capabilities, make navigation and localization difficult, especially in coastal regions where the majority of interesting phenomena occur. In this paper, we consider the combination of two methods for reducing navigation and localization error; a predictive approach based on ocean model predictions and a prior information approach derived from terrain-based navigation. The motivation for this work is not only for real-time state estimation, but also for accurately reconstructing the actual path that the vehicle traversed to contextualize the gathered data, with respect to the science question at hand. We present an application for the practical use of priors and predictions for large-scale ocean sampling. This combined approach builds upon previous works by the authors, and accurately localizes the traversed path of an underwater glider over long-duration, ocean deployments. The proposed method takes advantage of the reliable, short-term predictions of an ocean model, and the utility of priors used in terrain-based navigation over areas of significant bathymetric relief to bound uncertainty error in dead-reckoning navigation. This method improves upon our previously published works by 1 demonstrating the utility of our terrain-based navigation method with multiple field trials, and 2 presenting a hybrid algorithm that combines both approaches to bound navigational error and uncertainty for long-term deployments of underwater vehicles. We demonstrate the approach by examining data from actual field trials with autonomous underwater gliders, and demonstrate an ability to estimate geographical location of an underwater glider to 2

A Navigation/Positioning Service Based on Pseudolites Installed on Stratospheric Airships

OpenAIRE

辻井, 利昭; TSUJII, Toshiaki; 張替, 正敏; HARIGAE, Masatoshi

2002-01-01

Transmitters of GPS-like signals, called pseudolites (PL) or "pseudo-satellites" have been widely investigated as an additional ranging source for performance enhancement of GPS. Ground-based GPS augmentation systems using pseudolites have been investigated for several applications such as vehicle navigation in downtown urban canyons, positioning in deep open-cut pits and mines and precision landing of aircraft. The concept of an innovative GPS navigation/ positioning system augmented by airs...

Natural Environment Modeling and Fault-Diagnosis for Automated Agricultural Vehicle

DEFF Research Database (Denmark)

Blas, Morten Rufus; Blanke, Mogens

2008-01-01

This paper presents results for an automatic navigation system for agricultural vehicles. The system uses stereo-vision, inertial sensors and GPS. Special emphasis has been placed on modeling the natural environment in conjunction with a fault-tolerant navigation system. The results are exemplified...... by an agricultural vehicle following cut grass (swath). It is demonstrated how faults in the system can be detected and diagnosed using state of the art techniques from fault-tolerant literature. Results in performing fault-diagnosis and fault accomodation are presented using real data....

Autonomous aerial vehicles : guidance, control, signal and image processing platform

International Nuclear Information System (INIS)

Al-Jarrah, M.; Adiansyah, S.; Marji, Z. M.; Chowdhury, M. S.

2011-01-01

The use of unmanned systems is gaining momentum in civil applications after successful use by the armed forces around the globe. Autonomous aerial vehicles are important for providing assistance in monitoring highways, power grid lines, borders, and surveillance of critical infrastructures. It is envisioned that cargo shipping will be completely handled by UAVs by the 2025. Civil use of unmanned autonomous systems brings serious challenges. The need for cost effectiveness, reliability, operation simplicity, safety, and cooperation with human and with other agents are among these challenges. Aerial vehicles operating in the civilian aerospace is the ultimate goal which requires these systems to achieve the reliability of manned aircraft while maintaining their cost effectiveness. In this presentation the development of an autonomous fixed and rotary wing aerial vehicle will be discussed. The architecture of the system from the mission requirements to low level auto pilot control laws will be discussed. Trajectory tracking and path following guidance and control algorithms commonly used and their implementation using of the shelf low cost components will be presented. Autonomous takeo? landing is a key feature that was implemented onboard the vehicle to complete its degree of autonomy. This is implemented based on accurate air-data system designed and fused with sonar measurements, INS/GPS measurements, and vector field method guidance laws. The outcomes of the proposed research is that the AUS-UAV platform named MAZARI is capable of autonomous takeoff and landing based on a pre scheduled flight path using way point navigation and sensor fusion of the inertial navigation system (INS) and global positioning system (GPS). Several technologies need to be mastered when developing a UAV. The navigation task and the need to fuse sensory information to estimate the location of the vehicle is critical to successful autonomous vehicle. Currently extended Kalman filtering is

An adaptive deep-coupled GNSS/INS navigation system with hybrid pre-filter processing

Science.gov (United States)

Wu, Mouyan; Ding, Jicheng; Zhao, Lin; Kang, Yingyao; Luo, Zhibin

2018-02-01

The deep-coupling of a global navigation satellite system (GNSS) with an inertial navigation system (INS) can provide accurate and reliable navigation information. There are several kinds of deeply-coupled structures. These can be divided mainly into coherent and non-coherent pre-filter based structures, which have their own strong advantages and disadvantages, especially in accuracy and robustness. In this paper, the existing pre-filters of the deeply-coupled structures are analyzed and modified to improve them firstly. Then, an adaptive GNSS/INS deeply-coupled algorithm with hybrid pre-filters processing is proposed to combine the advantages of coherent and non-coherent structures. An adaptive hysteresis controller is designed to implement the hybrid pre-filters processing strategy. The simulation and vehicle test results show that the adaptive deeply-coupled algorithm with hybrid pre-filters processing can effectively improve navigation accuracy and robustness, especially in a GNSS-challenged environment.

Indoor wayfinding and navigation

CERN Document Server

2015-01-01

Due to the widespread use of navigation systems for wayfinding and navigation in the outdoors, researchers have devoted their efforts in recent years to designing navigation systems that can be used indoors. This book is a comprehensive guide to designing and building indoor wayfinding and navigation systems. It covers all types of feasible sensors (for example, Wi-Fi, A-GPS), discussing the level of accuracy, the types of map data needed, the data sources, and the techniques for providing routes and directions within structures.

Orion Optical Navigation Progress Toward Exploration: Mission 1

Science.gov (United States)

Holt, Greg N.; D'Souza, Christopher N.; Saley, David

2018-01-01

Optical navigation of human spacecraft was proposed on Gemini and implemented successfully on Apollo as a means of autonomously operating the vehicle in the event of lost communication with controllers on Earth. It shares a history with the "method of lunar distances" that was used in the 18th century and gained some notoriety after its use by Captain James Cook during his 1768 Pacific voyage of the HMS Endeavor. The Orion emergency return system utilizing optical navigation has matured in design over the last several years, and is currently undergoing the final implementation and test phase in preparation for Exploration Mission 1 (EM-1) in 2019. The software development is being worked as a Government Furnished Equipment (GFE) project delivered as an application within the Core Flight Software of the Orion camera controller module. The mathematical formulation behind the initial ellipse fit in the image processing is detailed in Christian. The non-linear least squares refinement then follows the technique of Mortari as an estimation process of the planetary limb using the sigmoid function. The Orion optical navigation system uses a body fixed camera, a decision that was driven by mass and mechanism constraints. The general concept of operations involves a 2-hour pass once every 24 hours, with passes specifically placed before all maneuvers to supply accurate navigation information to guidance and targeting. The pass lengths are limited by thermal constraints on the vehicle since the OpNav attitude generally deviates from the thermally stable tail-to-sun attitude maintained during the rest of the orbit coast phase. Calibration is scheduled prior to every pass due to the unknown nature of thermal effects on the lens distortion and the mounting platform deformations between the camera and star trackers. The calibration technique is described in detail by Christian, et al. and simultaneously estimates the Brown-Conrady coefficients and the Star Tracker

INFORMATION AS AN ELEMENT OF THE NAVIGATION DECISIONMAKING PROCESS

Directory of Open Access Journals (Sweden)

Andrzej BANACHOWICZ

2016-09-01

Full Text Available The operation of vehicles (watercraft, aircraft, land-based, spacecraft, unmanned requires the use of navigation systems for their control. These systems can be characterized by varying degrees of complexity and technological advancement. However, each system has sources of information about the state (position of the navigating object, state of the environment in which the object is moving and the task to be accomplished. These components are integrated by the decision-maker (human or automated, who/which makes and implements decisions adjusted to current conditions

Particle Filter Based Fault-tolerant ROV Navigation using Hydro-acoustic Position and Doppler Velocity Measurements

DEFF Research Database (Denmark)

Zhao, Bo; Blanke, Mogens; Skjetne, Roger

2012-01-01

This paper presents a fault tolerant navigation system for a remotely operated vehicle (ROV). The navigation system uses hydro-acoustic position reference (HPR) and Doppler velocity log (DVL) measurements to achieve an integrated navigation. The fault tolerant functionality is based on a modied...... particle lter. This particle lter is able to run in an asynchronous manner to accommodate the measurement drop out problem, and it overcomes the measurement outliers by switching observation models. Simulations with experimental data show that this fault tolerant navigation system can accurately estimate...

Squeezeposenet: Image Based Pose Regression with Small Convolutional Neural Networks for Real Time Uas Navigation

Science.gov (United States)

Müller, M. S.; Urban, S.; Jutzi, B.

2017-08-01

The number of unmanned aerial vehicles (UAVs) is increasing since low-cost airborne systems are available for a wide range of users. The outdoor navigation of such vehicles is mostly based on global navigation satellite system (GNSS) methods to gain the vehicles trajectory. The drawback of satellite-based navigation are failures caused by occlusions and multi-path interferences. Beside this, local image-based solutions like Simultaneous Localization and Mapping (SLAM) and Visual Odometry (VO) can e.g. be used to support the GNSS solution by closing trajectory gaps but are computationally expensive. However, if the trajectory estimation is interrupted or not available a re-localization is mandatory. In this paper we will provide a novel method for a GNSS-free and fast image-based pose regression in a known area by utilizing a small convolutional neural network (CNN). With on-board processing in mind, we employ a lightweight CNN called SqueezeNet and use transfer learning to adapt the network to pose regression. Our experiments show promising results for GNSS-free and fast localization.

Application of a distributed systems architecture for increased speed in image processing on an autonomous ground vehicle

Science.gov (United States)

Wright, Adam A.; Momin, Orko; Shin, Young Ho; Shakya, Rahul; Nepal, Kumud; Ahlgren, David J.

2010-01-01

This paper presents the application of a distributed systems architecture to an autonomous ground vehicle, Q, that participates in both the autonomous and navigation challenges of the Intelligent Ground Vehicle Competition. In the autonomous challenge the vehicle is required to follow a course, while avoiding obstacles and staying within the course boundaries, which are marked by white lines. For the navigation challenge, the vehicle is required to reach a set of target destinations, known as way points, with given GPS coordinates and avoid obstacles that it encounters in the process. Previously the vehicle utilized a single laptop to execute all processing activities including image processing, sensor interfacing and data processing, path planning and navigation algorithms and motor control. National Instruments' (NI) LabVIEW served as the programming language for software implementation. As an upgrade to last year's design, a NI compact Reconfigurable Input/Output system (cRIO) was incorporated to the system architecture. The cRIO is NI's solution for rapid prototyping that is equipped with a real time processor, an FPGA and modular input/output. Under the current system, the real time processor handles the path planning and navigation algorithms, the FPGA gathers and processes sensor data. This setup leaves the laptop to focus on running the image processing algorithm. Image processing as previously presented by Nepal et. al. is a multi-step line extraction algorithm and constitutes the largest processor load. This distributed approach results in a faster image processing algorithm which was previously Q's bottleneck. Additionally, the path planning and navigation algorithms are executed more reliably on the real time processor due to the deterministic nature of operation. The implementation of this architecture required exploration of various inter-system communication techniques. Data transfer between the laptop and the real time processor using UDP packets

Robotics Vision-based Heuristic Reasoning for Underwater Target Tracking and Navigation

Directory of Open Access Journals (Sweden)

Chua Kia

2005-09-01

Full Text Available This paper presents a robotics vision-based heuristic reasoning system for underwater target tracking and navigation. This system is introduced to improve the level of automation of underwater Remote Operated Vehicles (ROVs operations. A prototype which combines computer vision with an underwater robotics system is successfully designed and developed to perform target tracking and intelligent navigation. This study focuses on developing image processing algorithms and fuzzy inference system for the analysis of the terrain. The vision system developed is capable of interpreting underwater scene by extracting subjective uncertainties of the object of interest. Subjective uncertainties are further processed as multiple inputs of a fuzzy inference system that is capable of making crisp decisions concerning where to navigate. The important part of the image analysis is morphological filtering. The applications focus on binary images with the extension of gray-level concepts. An open-loop fuzzy control system is developed for classifying the traverse of terrain. The great achievement is the system's capability to recognize and perform target tracking of the object of interest (pipeline in perspective view based on perceived condition. The effectiveness of this approach is demonstrated by computer and prototype simulations. This work is originated from the desire to develop robotics vision system with the ability to mimic the human expert's judgement and reasoning when maneuvering ROV in the traverse of the underwater terrain.

Robotics Vision-based Heuristic Reasoning for Underwater Target Tracking and Navigation

Directory of Open Access Journals (Sweden)

Chua Kia

2008-11-01

Full Text Available This paper presents a robotics vision-based heuristic reasoning system for underwater target tracking and navigation. This system is introduced to improve the level of automation of underwater Remote Operated Vehicles (ROVs operations. A prototype which combines computer vision with an underwater robotics system is successfully designed and developed to perform target tracking and intelligent navigation. This study focuses on developing image processing algorithms and fuzzy inference system for the analysis of the terrain. The vision system developed is capable of interpreting underwater scene by extracting subjective uncertainties of the object of interest. Subjective uncertainties are further processed as multiple inputs of a fuzzy inference system that is capable of making crisp decisions concerning where to navigate. The important part of the image analysis is morphological filtering. The applications focus on binary images with the extension of gray-level concepts. An open-loop fuzzy control system is developed for classifying the traverse of terrain. The great achievement is the system's capability to recognize and perform target tracking of the object of interest (pipeline in perspective view based on perceived condition. The effectiveness of this approach is demonstrated by computer and prototype simulations. This work is originated from the desire to develop robotics vision system with the ability to mimic the human expert's judgement and reasoning when maneuvering ROV in the traverse of the underwater terrain.

Life Cycle Assessment of Connected and Automated Vehicles: Sensing and Computing Subsystem and Vehicle Level Effects.

Science.gov (United States)

Gawron, James H; Keoleian, Gregory A; De Kleine, Robert D; Wallington, Timothy J; Kim, Hyung Chul

2018-03-06

Although recent studies of connected and automated vehicles (CAVs) have begun to explore the potential energy and greenhouse gas (GHG) emission impacts from an operational perspective, little is known about how the full life cycle of the vehicle will be impacted. We report the results of a life cycle assessment (LCA) of Level 4 CAV sensing and computing subsystems integrated into internal combustion engine vehicle (ICEV) and battery electric vehicle (BEV) platforms. The results indicate that CAV subsystems could increase vehicle primary energy use and GHG emissions by 3-20% due to increases in power consumption, weight, drag, and data transmission. However, when potential operational effects of CAVs are included (e.g., eco-driving, platooning, and intersection connectivity), the net result is up to a 9% reduction in energy and GHG emissions in the base case. Overall, this study highlights opportunities where CAVs can improve net energy and environmental performance.

Applying Required Navigation Performance Concept for Traffic Management of Small Unmanned Aircraft Systems

Science.gov (United States)

Jung, Jaewoo; D'Souza, Sarah N.; Johnson, Marcus A.; Ishihara, Abraham K.; Modi, Hemil C.; Nikaido, Ben; Hasseeb, Hashmatullah

2016-01-01

In anticipation of a rapid increase in the number of civil Unmanned Aircraft System(UAS) operations, NASA is researching prototype technologies for a UAS Traffic Management (UTM) system that will investigate airspace integration requirements for enabling safe, efficient low-altitude operations. One aspect a UTM system must consider is the correlation between UAS operations (such as vehicles, operation areas and durations), UAS performance requirements, and the risk to people and property in the operational area. This paper investigates the potential application of the International Civil Aviation Organizations (ICAO) Required Navigation Performance (RNP) concept to relate operational risk with trajectory conformance requirements. The approach is to first define a method to quantify operational risk and then define the RNP level requirement as a function of the operational risk. Greater operational risk corresponds to more accurate RNP level, or smaller tolerable Total System Error (TSE). Data from 19 small UAS flights are used to develop and validate a formula that defines this relationship. An approach to assessing UAS-RNP conformance capability using vehicle modeling and wind field simulation is developed to investigate how this formula may be applied in a future UTM system. The results indicate the modeled vehicles flight path is robust to the simulated wind variation, and it can meet RNP level requirements calculated by the formula. The results also indicate how vehicle-modeling fidelity may be improved to adequately verify assessed RNP level.

Development of offroad unmanned dump truck navigation system. Dump truck mujin soko system no kaihatsu ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Horii, Z [Nittetsu Mining Co. Ltd., Tokyo (Japan)

1992-08-25

A large offroad unmanned dump truck navigation system has been developed, and is in practical operation mounted on dump trucks at Torigatayama Limestone Quarry of Nittetsu Mining Company. The system functions in a manual dump truck navigation mode, wireless navigation mode, and unmanned control mode. The unmanned control mode further includes a mode to navigate the truck on a predetermined course with its data having been input in a computer and a mode that when the truck was moved on a course under a wireless control, the computer learns the course and drives the truck autonomously thereafter. The safety measures are divided into the hardware safety function to detect abnormalities in brakes and other vehicle parts, and the software safety functions of data communications, sensor action check, and prevention of collision of trucks with each other. The system has resulted in a productivity of average one-way travel distance of 345 m, and average unmanned navigation cycle time of 9 minutes and 26 seconds for a transportation efficiency of 541 t/hour/truck, having reached at least the manned operation level. 4 figs., 1 tab.

Construction Method of the Topographical Features Model for Underwater Terrain Navigation

Directory of Open Access Journals (Sweden)

Wang Lihui

2015-09-01

Full Text Available Terrain database is the reference basic for autonomous underwater vehicle (AUV to implement underwater terrain navigation (UTN functions, and is the important part of building topographical features model for UTN. To investigate the feasibility and correlation of a variety of terrain parameters as terrain navigation information metrics, this paper described and analyzed the underwater terrain features and topography parameters calculation method. Proposing a comprehensive evaluation method for terrain navigation information, and constructing an underwater navigation information analysis model, which is associated with topographic features. Simulation results show that the underwater terrain features, are associated with UTN information directly or indirectly, also affect the terrain matching capture probability and the positioning accuracy directly.

GPS Navigation for the Magnetospheric Multi-Scale Mission

Science.gov (United States)

Bamford, William; Mitchell, Jason; Southward, Michael; Baldwin, Philip; Winternitz, Luke; Heckler, Gregory; Kurichh, Rishi; Sirotzky, Steve

2009-01-01

In 2014. NASA is scheduled to launch the Magnetospheric Multiscale Mission (MMS), a four-satellite formation designed to monitor fluctuations in the Earth's magnetosphere. This mission has two planned phases with different orbits (1? x 12Re and 1.2 x 25Re) to allow for varying science regions of interest. To minimize ground resources and to mitigate the probability of collisions between formation members, an on-board orbit determination system consisting of a Global Positioning System (GPS) receiver and crosslink transceiver was desired. Candidate sensors would be required to acquire GPS signals both below and above the constellation while spinning at three revolutions-per-minute (RPM) and exchanging state and science information among the constellation. The Intersatellite Ranging and Alarm System (IRAS), developed by Goddard Space Flight Center (GSFC) was selected to meet this challenge. IRAS leverages the eight years of development GSFC has invested in the Navigator GPS receiver and its spacecraft communication expertise, culminating in a sensor capable of absolute and relative navigation as well as intersatellite communication. The Navigator is a state-of-the-art receiver designed to acquire and track weak GPS signals down to -147dBm. This innovation allows the receiver to track both the main lobe and the much weaker side lobe signals. The Navigator's four antenna inputs and 24 tracking channels, together with customized hardware and software, allow it to seamlessly maintain visibility while rotating. Additionally, an extended Kalman filter provides autonomous, near real-time, absolute state and time estimates. The Navigator made its maiden voyage on the Space Shuttle during the Hubble Servicing Mission, and is scheduled to fly on MMS as well as the Global Precipitation Measurement Mission (GPM). Additionally, Navigator's acquisition engine will be featured in the receiver being developed for the Orion vehicle. The crosslink transceiver is a 1/4 Watt transmitter

Radioactive contamination level of vehicles resulted from transporting fine rare-earth minerals by rail

International Nuclear Information System (INIS)

Han Kaichun; Yu Boyong; Gao Shengwei

1997-01-01

This paper presents monitoring results of radioactive contamination level of steel open wagon surface resulted from transporting fine rare-earth minerals. Under promising transport conditions (the packaging consists of two layers of plastic bags and two layers of plastic net sacks, each package contains 50 kg of minerals, each vehicle carries 60 t), the surface radioactivity (total α and total β) of 16 vehicles on two lines from Baotou to Wujiachuan (924 km) and from Baotou to Sankeshu (2236 km) was measured before loading, after unloading and washing, using α and β surface contamination detector. The results showed that the radioactive contamination level of the vehicle surface after unloading appeared significantly different. The contamination level of vehicle bases was higher than that of both sides, long distance vehicles was higher than that of short distance vehicles. The radioactive contamination level of vehicles surface after washing was below the standard limits, these vehicles can be used for ordinary goods transport

Electric vehicle charging algorithms for coordination of the grid and distribution transformer levels

International Nuclear Information System (INIS)

Ramos Muñoz, Edgar; Razeghi, Ghazal; Zhang, Li; Jabbari, Faryar

2016-01-01

The need to reduce greenhouse gas emissions and fossil fuel consumption has increased the popularity of plug-in electric vehicles. However, a large penetration of plug-in electric vehicles can pose challenges at the grid and local distribution levels. Various charging strategies have been proposed to address such challenges, often separately. In this paper, it is shown that, with uncoordinated charging, distribution transformers and the grid can operate under highly undesirable conditions. Next, several strategies that require modest communication efforts are proposed to mitigate the burden created by high concentrations of plug-in electric vehicles, at the grid and local levels. Existing transformer and battery electric vehicle characteristics are used along with the National Household Travel Survey to simulate various charging strategies. It is shown through the analysis of hot spot temperature and equivalent aging factor that the coordinated strategies proposed here reduce the chances of transformer failure with the addition of plug-in electric vehicle loads, even for an under-designed transformer while uncontrolled and uncoordinated plug-in electric vehicle charging results in increased risk of transformer failure. - Highlights: • Charging algorithm for battery electric vehicles, for high penetration levels. • Algorithm reduces transformer overloading, for grid level valley filling. • Computation and communication requirements are minimal. • The distributed algorithm is implemented without large scale iterations. • Hot spot temperature and loss of life for transformers are evaluated.

Spoofing Detection Using GNSS/INS/Odometer Coupling for Vehicular Navigation.

Science.gov (United States)

Broumandan, Ali; Lachapelle, Gérard

2018-04-24

Location information is one of the most vital information required to achieve intelligent and context-aware capability for various applications such as driverless cars. However, related security and privacy threats are a major holdback. With increasing focus on using Global Navigation Satellite Systems (GNSS) for autonomous navigation and related applications, it is important to provide robust navigation solutions, yet signal spoofing for illegal or covert transportation and misleading receiver timing is increasing and now frequent. Hence, detection and mitigation of spoofing attacks has become an important topic. Several contributions on spoofing detection have been made, focusing on different layers of a GNSS receiver. This paper focuses on spoofing detection utilizing self-contained sensors, namely inertial measurement units (IMUs) and vehicle odometer outputs. A spoofing detection approach based on a consistency check between GNSS and IMU/odometer mechanization is proposed. To detect a spoofing attack, the method analyses GNSS and IMU/odometer measurements independently during a pre-selected observation window and cross checks the solutions provided by GNSS and inertial navigation solution (INS)/odometer mechanization. The performance of the proposed method is verified in real vehicular environments. Mean spoofing detection time and detection performance in terms of receiver operation characteristics (ROC) in sub-urban and dense urban environments are evaluated.

Spoofing Detection Using GNSS/INS/Odometer Coupling for Vehicular Navigation

Directory of Open Access Journals (Sweden)

Ali Broumandan

2018-04-01

Full Text Available Location information is one of the most vital information required to achieve intelligent and context-aware capability for various applications such as driverless cars. However, related security and privacy threats are a major holdback. With increasing focus on using Global Navigation Satellite Systems (GNSS for autonomous navigation and related applications, it is important to provide robust navigation solutions, yet signal spoofing for illegal or covert transportation and misleading receiver timing is increasing and now frequent. Hence, detection and mitigation of spoofing attacks has become an important topic. Several contributions on spoofing detection have been made, focusing on different layers of a GNSS receiver. This paper focuses on spoofing detection utilizing self-contained sensors, namely inertial measurement units (IMUs and vehicle odometer outputs. A spoofing detection approach based on a consistency check between GNSS and IMU/odometer mechanization is proposed. To detect a spoofing attack, the method analyses GNSS and IMU/odometer measurements independently during a pre-selected observation window and cross checks the solutions provided by GNSS and inertial navigation solution (INS/odometer mechanization. The performance of the proposed method is verified in real vehicular environments. Mean spoofing detection time and detection performance in terms of receiver operation characteristics (ROC in sub-urban and dense urban environments are evaluated.

DESIGN OF ROBUST NAVIGATION AND STABILIZATION LOOPS OF PRECISION ATTITUDE AND HEADING REFERENCE SYSTEM

Directory of Open Access Journals (Sweden)

Olha Sushchenko

2017-11-01

Full Text Available Purpose: The paper focuses on problems of design of robust precision attitude and heading reference systems, which can be applied in navigation of marine vehicles. The main goal is to create the optimization procedures for design of navigation and stabilization loops of the multimode gimballed system. The optimization procedure of the navigation loop design is based on the parametric robust H2/H∞-optimization. The optimization procedure of the stabilization loop design is based on the robust structural H∞-synthesis. Methods: To solve the given problem the methods of the robust control system theory and optimization methods are used. Results: The kinematical scheme of the precision gimballed attitude and heading reference system is represented. The parametrical optimization algorithm taking into consideration features of the researched system is given. Method of the mixed sensitivity relative to the researched system design is analyzed. Coefficients of the control laws of navigation loops are obtained based on optimization procedure providing compromise between accuracy and robustness. The robust controller of the stabilization loop was developed based on robust structural synthesis using method of the mixed sensitivity. Simulation of navigation and stabilization processes is carried out. Conclusions: The represented results prove efficiency of the proposed procedures, which can be useful for design of precision navigation systems of the moving vehicles.

Context-Aided Sensor Fusion for Enhanced Urban Navigation

Directory of Open Access Journals (Sweden)

Enrique David Martí

2012-12-01

Full Text Available  The deployment of Intelligent Vehicles in urban environments requires reliable estimation of positioning for urban navigation. The inherent complexity of this kind of environments fosters the development of novel systems which should provide reliable and precise solutions to the vehicle. This article details an advanced GNSS/IMU fusion system based on a context-aided Unscented Kalman filter for navigation in urban conditions. The constrained non-linear filter is here conditioned by a contextual knowledge module which reasons about sensor quality and driving context in order to adapt it to the situation, while at the same time it carries out a continuous estimation and correction of INS drift errors. An exhaustive analysis has been carried out with available data in order to characterize the behavior of available sensors and take it into account in the developed solution. The performance is then analyzed with an extensive dataset containing representative situations. The proposed solution suits the use of fusion algorithms for deploying Intelligent Transport Systems in urban environments.

ANALYSIS OF FREE ROUTE AIRSPACE AND PERFORMANCE BASED NAVIGATION IMPLEMENTATION IN THE EUROPEAN AIR NAVIGATION SYSTEM

Directory of Open Access Journals (Sweden)

Svetlana Pavlova

2014-12-01

Full Text Available European Air Traffic Management system requires continuous improvements as air traffic is increasingday by day. For this purpose it was developed by international organizations Free Route Airspace and PerformanceBased Navigation concepts that allow to offer a required level of safety, capacity, environmental performance alongwith cost-effectiveness. The aim of the article is to provide detailed analysis of Free Route Airspace and PerformanceBased Navigation implementation status within European region including Ukrainian air navigation system.

THE ROLE OF NAVIGATIONAL AIDS IN FLIGHT SAFETY MANAGEMENT WITHIN ICAO GLOBAL AIR NAVIGATION PLAN

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Vadim V. Vurobyov

2017-01-01

Full Text Available The development of the global civil aviation is provided on the basis of the ICAO Communication and Surveillance/Air Traffic Management Concept, which has determined the basic strategy for further commercial flight management effectiveness improvement. On the basis of this concept a Global Air Navigation Plan has been developed by ICAO recently. The core strategies of CNS/ATM concept were specified and combined into so-called blocks. Thus the term Global Aviation System block upgrade has been introduced. At the same time, GANP states that the introduction of new procedures and flight management systems will inevitably affect flight safety. Accordingly, there is a task of flight safety management level maintaining, or even increasing within the Global Air Navigation Plan implementation. Various air navigational aids play a significant role in the process as they are directly associated with the new systems and structures introduction.This breeds the new global challenge of flight safety management level change assessment during the introduction of new procedures and systems connected with the use of both navigational aids and instruments. Some aspects of this problem solution are covered in the article.

Tasking and control of a squad of robotic vehicles

Science.gov (United States)

Lewis, Christopher L.; Feddema, John T.; Klarer, Paul

2001-09-01

Sandia National Laboratories have developed a squad of robotic vehicles as a test-bed for investigating cooperative control strategies. The squad consists of eight RATLER vehicles and a command station. The RATLERs are medium-sized all-electric vehicles containing a PC104 stack for computation, control, and sensing. Three separate RF channels are used for communications; one for video, one for command and control, and one for differential GPS corrections. Using DGPS and IR proximity sensors, the vehicles are capable of autonomously traversing fairly rough terrain. The control station is a PC running Windows NT. A GUI has been developed that allows a single operator to task and monitor all eight vehicles. To date, the following mission capabilities have been demonstrated: 1. Way-Point Navigation, 2. Formation Following, 3. Perimeter Surveillance, 4. Surround and Diversion, and 5. DGPS Leap Frog. This paper describes the system and briefly outlines each mission capability. The DGPS Leap Frog capability is discussed in more detail. This capability is unique in that it demonstrates how cooperation allows the vehicles to accurately navigate beyond the RF communication range. One vehicle stops and uses its corrected GPS position to re-initialize its receiver to become the DGPS correction station for the other vehicles. Error in position accumulates each time a new vehicle takes over the DGPS duties. The accumulation in error is accurately modeled as a random walk phenomenon. This paper demonstrates how useful accuracy can be maintained beyond the vehicle's range.

A Conceptual Framework for Design of Embedded Systems and Data Communication for Autonomous Vehicles

DEFF Research Database (Denmark)

Nielsen, Jens Frederik Dalsgaard; Bendtsen, Jan Dimon; Nielsen, Kirsten Mølgaard

2005-01-01

systems in a set of time rings each demanding actions equal in time magnitude. The safety analysis can in an equal way structure the system in safety rings, each demanding fault and failure handling at the same level. The concept deals with the widely differing time demands at different control levels on......This paper describes a conceptual framework for the development of a hierarchal control architecture for an autonomous vehicle. The concept is based on time/frequency and safety analysis on board the vehicle. The time/frequency analysis is used to structure the guidance, navigation and control......-board the vehicle, the integration of sensors and actuators using different communication protocols, integration of wireless communication to a base and payload data handling as well as control, reliability and safety issues. The system is implemented on an autonomous platform mapping spatial density of weed...

The GNC Measurement System for the Automated Transfer Vehicle

Science.gov (United States)

Roux, Y.; da Cunha, P.

The Automated Transfer Vehicle (ATV) is a European Space Agency (ESA) funded spacecraft developed by EADS Space Transportation as prime contractor for the space segment together with major European industrial partners, in the frame of the International Space Station (ISS). Its mission objective is threefold : to supply the station with fret and propellant, to reboost ISS to a higher orbit and to dispose of waste from the station. The ATV first flight, called Jules Verne and planned on 2005, will be the first European Vehicle to perform an orbital rendezvous. The GNC Measurement System (GMS) is the ATV on board function in charge of the measurement data collection and preconditioning for the navigation, guidance and control (GNC) algorithms. The GMS is made up of hardware which are the navigation sensors (with a certain level of hardware redundancy for each of them), and of an on-board software that manages, monitors and performs consistency checks to detect and isolate potential sensor failures. The GMS relies on six kinds of navigation sensors, used during various phases of the mission : the gyrometers assembly (GYRA), the accelerometers assembly (ACCA), the star trackers (STR), the GPS receivers, the telegoniometers (TGM) and the videometers (VDM), the last two being used for the final rendezvous phase. The GMS function is developed by EADS Space Transportation together with other industrial partners: EADS Astrium, EADS Sodern, Laben and Dasa Jena Optronik.

Review of Optimization Strategies for System-Level Design in Hybrid Electric Vehicles

NARCIS (Netherlands)

Silvas, E.; Hofman, T.; Murgovski, N.; Etman, L.F.P.; Steinbuch, M.

2017-01-01

The optimal design of a hybrid electric vehicle (HEV) can be formulated as a multiobjective optimization problem that spreads over multiple levels (technology, topology, size, and control). In the last decade, studies have shown that by integrating these optimization levels, fuel benefits are

'Outsmarting Traffic, Together': Driving as Social Navigation

Directory of Open Access Journals (Sweden)

Sam Hind

2014-04-01

Full Text Available The automotive world is evolving. Ten years ago Nigel Thrift (2004: 41 made the claim that the experience of driving was slipping into our 'technological unconscious'. Only recently the New York Times suggested that with the rise of automated driving, standalone navigation tools as we know them would cease to exist, instead being 'fully absorbed into the machine' (Fisher, 2013. But in order to bridge the gap between past and future driving worlds, another technological evolution is emerging. This short, critical piece charts the rise of what has been called 'social navigation' in the industry; the development of digital mapping platforms designed to foster automotive sociality. It makes two provisional points. Firstly, that 'ludic' conceptualisations can shed light on the ongoing reconfiguration of drivers, vehicles, roads and technological aids such as touch-screen satellite navigation platforms. And secondly, that as a result of this, there is a coming-into-being of a new kind of driving politics; a 'casual politicking' centred on an engagement with digital interfaces. We explicate both by turning our attention towards Waze; a social navigation application that encourages users to interact with various driving dynamics.

Review of optimization strategies for system-level design in hybrid electric vehicles

NARCIS (Netherlands)

Silvas, E.; Hofman, T.; Murgovski, N.; Etman, P.; Steinbuch, M.

2017-01-01

The optimal design of a hybrid electric vehicle can be formulated as a multi-objective optimization problem that spreads over multiple levels (technology, topology, size and control). In the last decade, studies have shown that, by integrating these optimization levels fuel benefits are obtained,

Robotic security vehicle for exterior environments

International Nuclear Information System (INIS)

Klarer, P.R.; Workhoven, R.M.

1988-01-01

This paper describes a current effort at Sandia National Labs to develop an outdoor robotic vehicle capable of performing limited security functions autonomously in a structured environment. The present stage of development entails application of algorithms originally developed for the SIR vehicle to a testbed vehicle more appropriate to an outdoor environment. The current effort will culminate in a full scale demonstration of autonomous navigation capabilities on routine patrol and teleoperation by a human operator for alarm assessment and response. Various schemes for implementation of the robot system are discussed, as are plans for further development of the system

Launch vehicle design and GNC sizing with ASTOS

Science.gov (United States)

Cremaschi, Francesco; Winter, Sebastian; Rossi, Valerio; Wiegand, Andreas

2018-03-01

The European Space Agency (ESA) is currently involved in several activities related to launch vehicle designs (Future Launcher Preparatory Program, Ariane 6, VEGA evolutions, etc.). Within these activities, ESA has identified the importance of developing a simulation infrastructure capable of supporting the multi-disciplinary design and preliminary guidance navigation and control (GNC) design of different launch vehicle configurations. Astos Solutions has developed the multi-disciplinary optimization and launcher GNC simulation and sizing tool (LGSST) under ESA contract. The functionality is integrated in the Analysis, Simulation and Trajectory Optimization Software for space applications (ASTOS) and is intended to be used from the early design phases up to phase B1 activities. ASTOS shall enable the user to perform detailed vehicle design tasks and assessment of GNC systems, covering all aspects of rapid configuration and scenario management, sizing of stages, trajectory-dependent estimation of structural masses, rigid and flexible body dynamics, navigation, guidance and control, worst case analysis, launch safety analysis, performance analysis, and reporting.

Underwater Multi-Vehicle Trajectory Alignment and Mapping Using Acoustic and Optical Constraints

Directory of Open Access Journals (Sweden)

Ricard Campos

2016-03-01

Full Text Available Multi-robot formations are an important advance in recent robotic developments, as they allow a group of robots to merge their capacities and perform surveys in a more convenient way. With the aim of keeping the costs and acoustic communications to a minimum, cooperative navigation of multiple underwater vehicles is usually performed at the control level. In order to maintain the desired formation, individual robots just react to simple control directives extracted from range measurements or ultra-short baseline (USBL systems. Thus, the robots are unaware of their global positioning, which presents a problem for the further processing of the collected data. The aim of this paper is two-fold. First, we present a global alignment method to correct the dead reckoning trajectories of multiple vehicles to resemble the paths followed during the mission using the acoustic messages passed between vehicles. Second, we focus on the optical mapping application of these types of formations and extend the optimization framework to allow for multi-vehicle geo-referenced optical 3D mapping using monocular cameras. The inclusion of optical constraints is not performed using the common bundle adjustment techniques, but in a form improving the computational efficiency of the resulting optimization problem and presenting a generic process to fuse optical reconstructions with navigation data. We show the performance of the proposed method on real datasets collected within the Morph EU-FP7 project.

Design and Implementation of Vehicle Navigation System in Urban Environments using Internet of Things (Iot)

Science.gov (United States)

Godavarthi, Bhavana; Nalajala, Paparao; Ganapuram, Vasavi

2017-08-01

Advanced vehicle monitoring and tracking system based on embedded Linux board and android application is designed and implemented for monitoring the school vehicle from any location A to location B at real time. The present system would make good use of new technology that based on embedded Linux namely Raspberry Pi and Smartphone android application. This system works on GPS/GPRS/GSM SIM900A. GPS finds the current location of the vehicle, GPRS sends the tracking information to the server and the GSM is used for sending alert message to vehicle’s owner mobile. This system is placed inside the vehicle whose position is to be determined on the web page and monitored at real time. There is a comparison between the current vehicle path already specified paths into the file system. Inside the raspberry pi’s file system taken from vehicle owners through android phone using android application. Means the selection of path from location A to B takes place from vehicle owner’s android application which gives more safety and secures traveling to the traveler. Hence the driver drives the vehicle only on the vehicle owner’s specified path. The driver drives the vehicle only on the vehicle owner’s specified path but if the driver drives in wrong path the message alert will be sent from this system to the vehicle owners mobile and also sent speakers alert to driver through audio jack. If the vehicles speed goes beyond the specified value of the speed, then warning message will be sent to owner mobile. This system also takes care of the traveler’s safety by using Gas leakage and Temperature sensors

Orion Exploration Flight Test-l (EFT -1) Absolute Navigation Design

Science.gov (United States)

Sud, Jastesh; Gay, Robert; Holt, Greg; Zanetti, Renato

2014-01-01

Scheduled to launch in September 2014 atop a Delta IV Heavy from the Kennedy Space Center, the Orion Multi-Purpose-Crew-Vehicle (MPCV's) maiden flight dubbed "Exploration Flight Test -1" (EFT-1) intends to stress the system by placing the uncrewed vehicle on a high-energy parabolic trajectory replicating conditions similar to those that would be experienced when returning from an asteroid or a lunar mission. Unique challenges associated with designing the navigation system for EFT-1 are presented in the narrative with an emphasis on how redundancy and robustness influenced the architecture. Two Inertial Measurement Units (IMUs), one GPS receiver and three barometric altimeters (BALTs) comprise the navigation sensor suite. The sensor data is multiplexed using conventional integration techniques and the state estimate is refined by the GPS pseudorange and deltarange measurements in an Extended Kalman Filter (EKF) that employs the UDUT decomposition approach. The design is substantiated by simulation results to show the expected performance.

A model-based eco-routing strategy for electric vehicles in large urban networks

OpenAIRE

De Nunzio , Giovanni; Thibault , Laurent; Sciarretta , Antonio

2016-01-01

International audience; A novel eco-routing navigation strategy and energy consumption modeling approach for electric vehicles are presented in this work. Speed fluctuations and road network infrastructure have a large impact on vehicular energy consumption. Neglecting these effects may lead to large errors in eco-routing navigation, which could trivially select the route with the lowest average speed. We propose an energy consumption model that considers both accelerations and impact of the ...

Modeling take-over performance in level 3 conditionally automated vehicles.

Science.gov (United States)

Gold, Christian; Happee, Riender; Bengler, Klaus

2017-11-28

Taking over vehicle control from a Level 3 conditionally automated vehicle can be a demanding task for a driver. The take-over determines the controllability of automated vehicle functions and thereby also traffic safety. This paper presents models predicting the main take-over performance variables take-over time, minimum time-to-collision, brake application and crash probability. These variables are considered in relation to the situational and driver-related factors time-budget, traffic density, non-driving-related task, repetition, the current lane and driver's age. Regression models were developed using 753 take-over situations recorded in a series of driving simulator experiments. The models were validated with data from five other driving simulator experiments of mostly unrelated authors with another 729 take-over situations. The models accurately captured take-over time, time-to-collision and crash probability, and moderately predicted the brake application. Especially the time-budget, traffic density and the repetition strongly influenced the take-over performance, while the non-driving-related tasks, the lane and drivers' age explained a minor portion of the variance in the take-over performances. Copyright © 2017 Elsevier Ltd. All rights reserved.

Demonstration of a Concurrently Programmed Tactical Level Control Software for Autonomous Vehicles and the Interface to the Execution Level Code

National Research Council Canada - National Science Library

Carroll, William

2000-01-01

.... One of the greatest challenges to the successful development of truly autonomous vehicles is the ability to link logically based high-level mission planning with low-level vehicle control software...

Systems and Methods for Determining Inertial Navigation System Faults

Science.gov (United States)

Bharadwaj, Raj Mohan (Inventor); Bageshwar, Vibhor L. (Inventor); Kim, Kyusung (Inventor)

2017-01-01

An inertial navigation system (INS) includes a primary inertial navigation system (INS) unit configured to receive accelerometer measurements from an accelerometer and angular velocity measurements from a gyroscope. The primary INS unit is further configured to receive global navigation satellite system (GNSS) signals from a GNSS sensor and to determine a first set of kinematic state vectors based on the accelerometer measurements, the angular velocity measurements, and the GNSS signals. The INS further includes a secondary INS unit configured to receive the accelerometer measurements and the angular velocity measurements and to determine a second set of kinematic state vectors of the vehicle based on the accelerometer measurements and the angular velocity measurements. A health management system is configured to compare the first set of kinematic state vectors and the second set of kinematic state vectors to determine faults associated with the accelerometer or the gyroscope based on the comparison.

Landmark-based robust navigation for tactical UGV control in GPS-denied communication-degraded environments

Science.gov (United States)

Endo, Yoichiro; Balloch, Jonathan C.; Grushin, Alexander; Lee, Mun Wai; Handelman, David

2016-05-01

Control of current tactical unmanned ground vehicles (UGVs) is typically accomplished through two alternative modes of operation, namely, low-level manual control using joysticks and high-level planning-based autonomous control. Each mode has its own merits as well as inherent mission-critical disadvantages. Low-level joystick control is vulnerable to communication delay and degradation, and high-level navigation often depends on uninterrupted GPS signals and/or energy-emissive (non-stealth) range sensors such as LIDAR for localization and mapping. To address these problems, we have developed a mid-level control technique where the operator semi-autonomously drives the robot relative to visible landmarks that are commonly recognizable by both humans and machines such as closed contours and structured lines. Our novel solution relies solely on optical and non-optical passive sensors and can be operated under GPS-denied, communication-degraded environments. To control the robot using these landmarks, we developed an interactive graphical user interface (GUI) that allows the operator to select landmarks in the robot's view and direct the robot relative to one or more of the landmarks. The integrated UGV control system was evaluated based on its ability to robustly navigate through indoor environments. The system was successfully field tested with QinetiQ North America's TALON UGV and Tactical Robot Controller (TRC), a ruggedized operator control unit (OCU). We found that the proposed system is indeed robust against communication delay and degradation, and provides the operator with steady and reliable control of the UGV in realistic tactical scenarios.

AN AUTONOMOUS GPS-DENIED UNMANNED VEHICLE PLATFORM BASED ON BINOCULAR VISION FOR PLANETARY EXPLORATION

Directory of Open Access Journals (Sweden)

M. Qin

2018-04-01

Full Text Available Vision-based navigation has become an attractive solution for autonomous navigation for planetary exploration. This paper presents our work of designing and building an autonomous vision-based GPS-denied unmanned vehicle and developing an ARFM (Adaptive Robust Feature Matching based VO (Visual Odometry software for its autonomous navigation. The hardware system is mainly composed of binocular stereo camera, a pan-and tilt, a master machine, a tracked chassis. And the ARFM-based VO software system contains four modules: camera calibration, ARFM-based 3D reconstruction, position and attitude calculation, BA (Bundle Adjustment modules. Two VO experiments were carried out using both outdoor images from open dataset and indoor images captured by our vehicle, the results demonstrate that our vision-based unmanned vehicle is able to achieve autonomous localization and has the potential for future planetary exploration.

An Autonomous Gps-Denied Unmanned Vehicle Platform Based on Binocular Vision for Planetary Exploration

Science.gov (United States)

Qin, M.; Wan, X.; Shao, Y. Y.; Li, S. Y.

2018-04-01

Vision-based navigation has become an attractive solution for autonomous navigation for planetary exploration. This paper presents our work of designing and building an autonomous vision-based GPS-denied unmanned vehicle and developing an ARFM (Adaptive Robust Feature Matching) based VO (Visual Odometry) software for its autonomous navigation. The hardware system is mainly composed of binocular stereo camera, a pan-and tilt, a master machine, a tracked chassis. And the ARFM-based VO software system contains four modules: camera calibration, ARFM-based 3D reconstruction, position and attitude calculation, BA (Bundle Adjustment) modules. Two VO experiments were carried out using both outdoor images from open dataset and indoor images captured by our vehicle, the results demonstrate that our vision-based unmanned vehicle is able to achieve autonomous localization and has the potential for future planetary exploration.

Flight Test Result for the Ground-Based Radio Navigation System Sensor with an Unmanned Air Vehicle.

Science.gov (United States)

Jang, Jaegyu; Ahn, Woo-Guen; Seo, Seungwoo; Lee, Jang Yong; Park, Jun-Pyo

2015-11-11

The Ground-based Radio Navigation System (GRNS) is an alternative/backup navigation system based on time synchronized pseudolites. It has been studied for some years due to the potential vulnerability issue of satellite navigation systems (e.g., GPS or Galileo). In the framework of our study, a periodic pulsed sequence was used instead of the randomized pulse sequence recommended as the RTCM (radio technical commission for maritime services) SC (special committee)-104 pseudolite signal, as a randomized pulse sequence with a long dwell time is not suitable for applications requiring high dynamics. This paper introduces a mathematical model of the post-correlation output in a navigation sensor, showing that the aliasing caused by the additional frequency term of a periodic pulsed signal leads to a false lock (i.e., Doppler frequency bias) during the signal acquisition process or in the carrier tracking loop of the navigation sensor. We suggest algorithms to resolve the frequency false lock issue in this paper, relying on the use of a multi-correlator. A flight test with an unmanned helicopter was conducted to verify the implemented navigation sensor. The results of this analysis show that there were no false locks during the flight test and that outliers stem from bad dilution of precision (DOP) or fluctuations in the received signal quality.

A Robust Vehicle Localization Approach Based on GNSS/IMU/DMI/LiDAR Sensor Fusion for Autonomous Vehicles

Directory of Open Access Journals (Sweden)

Xiaoli Meng

2017-09-01

Full Text Available Precise and robust localization in a large-scale outdoor environment is essential for an autonomous vehicle. In order to improve the performance of the fusion of GNSS (Global Navigation Satellite System/IMU (Inertial Measurement Unit/DMI (Distance-Measuring Instruments, a multi-constraint fault detection approach is proposed to smooth the vehicle locations in spite of GNSS jumps. Furthermore, the lateral localization error is compensated by the point cloud-based lateral localization method proposed in this paper. Experiment results have verified the algorithms proposed in this paper, which shows that the algorithms proposed in this paper are capable of providing precise and robust vehicle localization.

A Robust Vehicle Localization Approach Based on GNSS/IMU/DMI/LiDAR Sensor Fusion for Autonomous Vehicles.

Science.gov (United States)

Meng, Xiaoli; Wang, Heng; Liu, Bingbing

2017-09-18

Precise and robust localization in a large-scale outdoor environment is essential for an autonomous vehicle. In order to improve the performance of the fusion of GNSS (Global Navigation Satellite System)/IMU (Inertial Measurement Unit)/DMI (Distance-Measuring Instruments), a multi-constraint fault detection approach is proposed to smooth the vehicle locations in spite of GNSS jumps. Furthermore, the lateral localization error is compensated by the point cloud-based lateral localization method proposed in this paper. Experiment results have verified the algorithms proposed in this paper, which shows that the algorithms proposed in this paper are capable of providing precise and robust vehicle localization.

Developments in Acoustic Navigation and Communication for High-Latitude Ocean Research

Science.gov (United States)

Gobat, J.; Lee, C.

2006-12-01

Developments in autonomous platforms (profiling floats, drifters, long-range gliders and propeller-driven vehicles) offer the possibility of unprecedented access to logistically difficult polar regions that challenge conventional techniques. Currently, however, navigation and telemetry for these platforms rely on satellite positioning and communications poorly suited for high-latitude applications where ice cover restricts access to the sea surface. A similar infrastructure offering basin-wide acoustic geolocation and telemetry would allow the community to employ autonomous platforms to address previously intractable problems in Arctic oceanography. Two recent efforts toward the development of such an infrastructure are reported here. As part of an observational array monitoring fluxes through Davis Strait, development of real-time RAFOS acoustic navigation for gliders has been ongoing since autumn 2004. To date, test deployments have been conducted in a 260 Hz field in the Pacific and 780 Hz fields off Norway and in Davis Strait. Real-time navigation accuracy of ~1~km is achievable. Autonomously navigating gliders will operate under ice cover beginning in autumn 2006. In addition to glider navigation development, the Davis Strait array moorings carry fixed RAFOS recorders to study propagation over a range of distances under seasonally varying ice cover. Results from the under-ice propagation and glider navigation experiments are presented. Motivated by the need to coordinate these types of development efforts, an international group of acousticians, autonomous platform developers, high-latitude oceanographers and marine mammal researchers gathered in Seattle, U.S.A. from 27 February -- 1 March 2006 for an NSF Office of Polar Programs sponsored Acoustic Navigation and Communication for High-latitude Ocean Research (ANCHOR) workshop. Workshop participants focused on summarizing the current state of knowledge concerning Arctic acoustics, navigation and communications

Memristive device based learning for navigation in robots.

Science.gov (United States)

Sarim, Mohammad; Kumar, Manish; Jha, Rashmi; Minai, Ali A

2017-11-08

Biomimetic robots have gained attention recently for various applications ranging from resource hunting to search and rescue operations during disasters. Biological species are known to intuitively learn from the environment, gather and process data, and make appropriate decisions. Such sophisticated computing capabilities in robots are difficult to achieve, especially if done in real-time with ultra-low energy consumption. Here, we present a novel memristive device based learning architecture for robots. Two terminal memristive devices with resistive switching of oxide layer are modeled in a crossbar array to develop a neuromorphic platform that can impart active real-time learning capabilities in a robot. This approach is validated by navigating a robot vehicle in an unknown environment with randomly placed obstacles. Further, the proposed scheme is compared with reinforcement learning based algorithms using local and global knowledge of the environment. The simulation as well as experimental results corroborate the validity and potential of the proposed learning scheme for robots. The results also show that our learning scheme approaches an optimal solution for some environment layouts in robot navigation.

Multi-modal assessment of on-road demand of voice and manual phone calling and voice navigation entry across two embedded vehicle systems

Science.gov (United States)

Mehler, Bruce; Kidd, David; Reimer, Bryan; Reagan, Ian; Dobres, Jonathan; McCartt, Anne

2016-01-01

Abstract One purpose of integrating voice interfaces into embedded vehicle systems is to reduce drivers’ visual and manual distractions with ‘infotainment’ technologies. However, there is scant research on actual benefits in production vehicles or how different interface designs affect attentional demands. Driving performance, visual engagement, and indices of workload (heart rate, skin conductance, subjective ratings) were assessed in 80 drivers randomly assigned to drive a 2013 Chevrolet Equinox or Volvo XC60. The Chevrolet MyLink system allowed completing tasks with one voice command, while the Volvo Sensus required multiple commands to navigate the menu structure. When calling a phone contact, both voice systems reduced visual demand relative to the visual–manual interfaces, with reductions for drivers in the Equinox being greater. The Equinox ‘one-shot’ voice command showed advantages during contact calling but had significantly higher error rates than Sensus during destination address entry. For both secondary tasks, neither voice interface entirely eliminated visual demand. Practitioner Summary: The findings reinforce the observation that most, if not all, automotive auditory–vocal interfaces are multi-modal interfaces in which the full range of potential demands (auditory, vocal, visual, manipulative, cognitive, tactile, etc.) need to be considered in developing optimal implementations and evaluating drivers’ interaction with the systems. Social Media: In-vehicle voice-interfaces can reduce visual demand but do not eliminate it and all types of demand need to be taken into account in a comprehensive evaluation. PMID:26269281

Multi-modal assessment of on-road demand of voice and manual phone calling and voice navigation entry across two embedded vehicle systems.

Science.gov (United States)

Mehler, Bruce; Kidd, David; Reimer, Bryan; Reagan, Ian; Dobres, Jonathan; McCartt, Anne

2016-03-01

One purpose of integrating voice interfaces into embedded vehicle systems is to reduce drivers' visual and manual distractions with 'infotainment' technologies. However, there is scant research on actual benefits in production vehicles or how different interface designs affect attentional demands. Driving performance, visual engagement, and indices of workload (heart rate, skin conductance, subjective ratings) were assessed in 80 drivers randomly assigned to drive a 2013 Chevrolet Equinox or Volvo XC60. The Chevrolet MyLink system allowed completing tasks with one voice command, while the Volvo Sensus required multiple commands to navigate the menu structure. When calling a phone contact, both voice systems reduced visual demand relative to the visual-manual interfaces, with reductions for drivers in the Equinox being greater. The Equinox 'one-shot' voice command showed advantages during contact calling but had significantly higher error rates than Sensus during destination address entry. For both secondary tasks, neither voice interface entirely eliminated visual demand. Practitioner Summary: The findings reinforce the observation that most, if not all, automotive auditory-vocal interfaces are multi-modal interfaces in which the full range of potential demands (auditory, vocal, visual, manipulative, cognitive, tactile, etc.) need to be considered in developing optimal implementations and evaluating drivers' interaction with the systems. Social Media: In-vehicle voice-interfaces can reduce visual demand but do not eliminate it and all types of demand need to be taken into account in a comprehensive evaluation.

Autonomous Navigation and Obstacle Avoidance of a Micro-Bus

Directory of Open Access Journals (Sweden)

Carlos Fernández

2013-04-01

Full Text Available At present, the topic of automated vehicles is one of the most promising research areas in the field of Intelligent Transportation Systems (ITS. The use of automated vehicles for public transportation also contributes to reductions in congestion levels and to improvements in traffic flow. Moreover, electrical public autonomous vehicles are environmentally friendly, provide better air quality and contribute to energy conservation. The driverless public transportation systems, which are at present operating in some airports and train stations, are restricted to dedicated roads and exhibit serious trouble dynamically avoiding obstacles in the trajectory. In this paper, an electric autonomous mini-bus is presented. All datasets used in this article were collected during the experiments carried out in the demonstration event of the 2012 IEEE Intelligent Vehicles Symposium that took place in Alcalá de Henares (Spain. The demonstration consisted of a route 725 metres long containing a list of latitude-longitude points (waypoints. The mini-bus was capable of driving autonomously from one waypoint to another using a GPS sensor. Furthermore, the vehicle is provided with a multi-beam Laser Imaging Detection and Ranging (LIDAR sensor for surrounding reconstruction and obstacle detection. When an obstacle is detected in the planned path, the planned route is modified in order to avoid the obstacle and continue its way to the end of the mission. On the demonstration day, a total of 196 attendees had the opportunity to get a ride on the vehicles. A total of 28 laps were successfully completed in full autonomous mode in a private circuit located in the National Institute for Aerospace Research (INTA, Spain. In other words, the system completed 20.3 km of driverless navigation and obstacle avoidance.

An innovative information fusion method with adaptive Kalman filter for integrated INS/GPS navigation of autonomous vehicles

Science.gov (United States)

Liu, Yahui; Fan, Xiaoqian; Lv, Chen; Wu, Jian; Li, Liang; Ding, Dawei

2018-02-01

Information fusion method of INS/GPS navigation system based on filtering technology is a research focus at present. In order to improve the precision of navigation information, a navigation technology based on Adaptive Kalman Filter with attenuation factor is proposed to restrain noise in this paper. The algorithm continuously updates the measurement noise variance and processes noise variance of the system by collecting the estimated and measured values, and this method can suppress white noise. Because a measured value closer to the current time would more accurately reflect the characteristics of the noise, an attenuation factor is introduced to increase the weight of the current value, in order to deal with the noise variance caused by environment disturbance. To validate the effectiveness of the proposed algorithm, a series of road tests are carried out in urban environment. The GPS and IMU data of the experiments were collected and processed by dSPACE and MATLAB/Simulink. Based on the test results, the accuracy of the proposed algorithm is 20% higher than that of a traditional Adaptive Kalman Filter. It also shows that the precision of the integrated navigation can be improved due to the reduction of the influence of environment noise.

Navigation System Fault Diagnosis for Underwater Vehicle

DEFF Research Database (Denmark)

Falkenberg, Thomas; Gregersen, Rene Tavs; Blanke, Mogens

2014-01-01

This paper demonstrates fault diagnosis on unmanned underwater vehicles (UUV) based on analysis of structure of the nonlinear dynamics. Residuals are generated using dierent approaches in structural analysis followed by statistical change detection. Hypothesis testing thresholds are made signal...... based to cope with non-ideal properties seen in real data. Detection of both sensor and thruster failures are demonstrated. Isolation is performed using the residual signature of detected faults and the change detection algorithm is used to assess severity of faults by estimating their magnitude...

A Common Communications, Navigation and Surveillance Infrastructure for Accommodating Space Vehicles in the Next Generation Air Transportation System

Science.gov (United States)

VanSuetendael, RIchard; Hayes, Alan; Birr, Richard

2008-01-01

Suborbital space flight and space tourism are new potential markets that could significantly impact the National Airspace System (NAS). Numerous private companies are developing space flight capabilities to capture a piece of an emerging commercial space transportation market. These entrepreneurs share a common vision that sees commercial space flight as a profitable venture. Additionally, U.S. space exploration policy and national defense will impose significant additional demands on the NAS. Air traffic service providers must allow all users fair access to limited airspace, while ensuring that the highest levels of safety, security, and efficiency are maintained. The FAA's Next Generation Air Transportation System (NextGen) will need to accommodate spacecraft transitioning to and from space through the NAS. To accomplish this, space and air traffic operations will need to be seamlessly integrated under some common communications, navigation and surveillance (CNS) infrastructure. As part of NextGen, the FAA has been developing the Automatic Dependent Surveillance Broadcast (ADS-B) which utilizes the Global Positioning System (GPS) to track and separate aircraft. Another key component of NextGen, System-Wide Information Management/ Network Enabled Operations (SWIM/NEO), is an open architecture network that will provide NAS data to various customers, system tools and applications. NASA and DoD are currently developing a space-based range (SBR) concept that also utilizes GPS, communications satellites and other CNS assets. The future SBR will have very similar utility for space operations as ADS-B and SWIM has for air traffic. Perhaps the FAA, NASA, and DoD should consider developing a common space-based CNS infrastructure to support both aviation and space transportation operations. This paper suggests specific areas of research for developing a CNS infrastructure that can accommodate spacecraft and other new types of vehicles as an integrated part of NextGen.

Maneuverability Strategy for Assistive Maneuverability Strategy for Assistive Vehicles Navigating within Confined Space

Directory of Open Access Journals (Sweden)

Fernando Auat Cheein

2011-08-01

Full Text Available In this work, a path planning strategy for both a car-like and a unicycle type assistive vehicles is presented. The assistive vehicles are confined to restricted environments. The path planning strategy uses the environment information to generate a kinematically plausible path to be followed by the vehicle. The environment information is provided by a SLAM (Simultaneous Localization and Mapping algorithm implemented on the vehicles. The map generated by the SLAM algorithm compensates the lack of sensor at the back of the vehicles' chassis. A Monte Carlo-based technique is used to find the optimum path given the SLAM information. A visual and user-friendly interface enhances the user-vehicle communication allowing him/her to select a desired position and orientation (pose that the vehicle should reach within the mapped environment. A trajectory controller drives the vehicle until it reaches a neighborhood of the desired pose. Several real-time experimental results within real environments are also shown herein.

Development and application of underwater robot vehicle for close inspection of spent fuels

Energy Technology Data Exchange (ETDEWEB)

Yun, J. S.; Park, B. S.; Song, T. G.; Kim, S. H.; Cho, M. W.; Ahn, S. H.; Lee, J. Y.; Oh, S. C.; Oh, W. J.; Shin, K. W.; Woo, D. H.; Kim, H. G.; Park, J. S

1999-12-01

The research and development efforts of the underwater robotic vehicle for inspection of spent fuels are focused on the development of an robotic vehicle which inspects spent fuels in the storage pool through remotely controlled actuation. For this purpose, a self balanced vehicle actuated by propellers is designed and fabricated, which consists of a radiation resistance camera, two illuminators, a pressure transducer and a manipulator. the algorithm for autonomous navigation is developed and its performance is tested at the swimming pool. The results of the underwater vehicle shows that the vehicle can easily navigate into the arbitrary directions while maintaining its balanced position. The camera provides a clear view of working environment by using the macro and zoom functions. The camera tilt device provides a wide field of view which is enough for monitoring the operation of manipulator. Also, the manipulator can pick up the dropped objects up to 4 kgf of weight. (author)

Design and Implementation of a Fully Autonomous UAV's Navigator Based on Omni-directional Vision System

Directory of Open Access Journals (Sweden)

Seyed Mohammadreza Kasaei

2011-12-01

Full Text Available Unmanned Aerial Vehicles (UAVs are the subject of an increasing interest in many applications . UAVs are seeing more widespread use in military, scenic, and civilian sectors in recent years. Autonomy is one of the major advantages of these vehicles. It is then necessary to develop particular sensor in order to provide efficient navigation functions. The helicopter has been stabilized with visual information through the control loop. Omni directional vision can be a useful sensor for this propose. It can be used as the only sensor or as complementary sensor. In this paper , we propose a novel method for path planning on an UAV based on electrical potential .We are using an omni directional vision system for navigating and path planning.

State-of-the-Art System Solutions for Unmanned Underwater Vehicles

Directory of Open Access Journals (Sweden)

A. E. Yilmaz

2009-12-01

Full Text Available Unmanned Underwater Vehicles (UUVs have gained popularity for the last decades, especially for the purpose of not risking human life in dangerous operations. On the other hand, underwater environment introduces numerous challenges in navigation, control and communication of such vehicles. Certainly, this fact makes the development of these vehicles more interesting and engineering-wise more attractive. In this paper, we first revisit the existing technology and methodology for the solution of aforementioned problems, then we try to come up with a system solution of a generic unmanned underwater vehicles.

An optimal control-based algorithm for hybrid electric vehicle using preview route information

NARCIS (Netherlands)

Ngo, D.V.; Hofman, T.; Steinbuch, M.; Serrarens, A.F.A.

2010-01-01

Control strategies for Hybrid Electric Vehicles (HEVs) are generally aimed at optimally choosing the power distribution between the internal combustion engine and the electric motor in order to minimize the fuel consumption and/or emissions. Using vehicle navigation systems in combination with

GPS/DR Error Estimation for Autonomous Vehicle Localization.

Science.gov (United States)

Lee, Byung-Hyun; Song, Jong-Hwa; Im, Jun-Hyuck; Im, Sung-Hyuck; Heo, Moon-Beom; Jee, Gyu-In

2015-08-21

Autonomous vehicles require highly reliable navigation capabilities. For example, a lane-following method cannot be applied in an intersection without lanes, and since typical lane detection is performed using a straight-line model, errors can occur when the lateral distance is estimated in curved sections due to a model mismatch. Therefore, this paper proposes a localization method that uses GPS/DR error estimation based on a lane detection method with curved lane models, stop line detection, and curve matching in order to improve the performance during waypoint following procedures. The advantage of using the proposed method is that position information can be provided for autonomous driving through intersections, in sections with sharp curves, and in curved sections following a straight section. The proposed method was applied in autonomous vehicles at an experimental site to evaluate its performance, and the results indicate that the positioning achieved accuracy at the sub-meter level.

Vehicle state estimation using GPS/IMU integration

NARCIS (Netherlands)

Wang, Y.; Mangnus, J.; Kostić, D.; Nijmeijer, H.; Jansen, S.T.H.

2011-01-01

New driver support systems require knowledge of the vehicle position with great accuracy and reliability. Satellite navigation (GNSS) is generally insufficiently accurate for positioning and as an alternative to using a ground station, combinations with high quality motion sensors are used in

DVL Velocity Aiding in the HUGIN 1000 Integrated Inertial Navigation System

Directory of Open Access Journals (Sweden)

Bjørn Jalving

2004-10-01

Full Text Available The RDI WHN-600 Doppler Velocity Log (DVL is a key navigation sensor for the HUG1N 1000 Autonomous Underwater Vehicle (AUV. HUGIN 1000 is designed for autonomous submerged operation for long periods of time. This is facilitated by a low drift velocity aided Inertial Navigation System (INS. Major factors determining the position error growth are the IMU and DVL error characteristics and the mission plan pattern_ For instance, low frequency DVL errors cause an approximately linear drift in a straight-line trajectory, while these errors tend to be cancelled out by a lawn mower pattern_ The paper focuses on the accuracy offered by the DVL. HUGIN 1000 is a permanent organic mine countermeasure (MCM capacity on the Royal Norwegian Navy MCM vessel KNM Karmoy. HUGIN 1000 will be part of the NATO force MCMFORNORTH in fall 2004.

Architectural Design for a Mars Communications and Navigation Orbital Infrastructure

Science.gov (United States)

Ceasrone R. J.; Hastrup, R. C.; Bell, D. J.; Roncoli, R. B.; Nelson, K.

1999-01-01

The planet Mars has become the focus of an intensive series of missions that span decades of time, a wide array of international agencies and an evolution from robotics to humans. The number of missions to Mars at any one time, and over a period of time, is unprecedented in the annals of space exploration. To meet the operational needs of this exploratory fleet will require the implementation of new architectural concepts for communications and navigation. To this end, NASA's Jet Propulsion Laboratory has begun to define and develop a Mars communications and navigation orbital infrastructure. This architecture will make extensive use of assets at Mars, as well as use of traditional Earth-based assets, such as the Deep Space Network, DSN. Indeed, the total system can be thought of as an extension of DSN nodes and services to the Mars in-situ region. The concept has been likened to the beginnings of an interplanetary Internet that will bring the exploration of Mars right into our living rooms. The paper will begin with a high-level overview of the concept for the Mars communications and navigation infrastructure. Next, the mission requirements will be presented. These will include the relatively near-term needs of robotic landers, rovers, ascent vehicles, balloons, airplanes, and possibly orbiting, arriving and departing spacecraft. Requirements envisioned for the human exploration of Mars will also be described. The important Mars orbit design trades on telecommunications and navigation capabilities will be summarized, and the baseline infrastructure will be described. A roadmap of NASA's plan to evolve this infrastructure over time will be shown. Finally, launch considerations and delivery to Mars will be briefly treated.

Determination of UAV position using high accuracy navigation platform

Directory of Open Access Journals (Sweden)

Ireneusz Kubicki

2016-07-01

Full Text Available The choice of navigation system for mini UAV is very important because of its application and exploitation, particularly when the installed on it a synthetic aperture radar requires highly precise information about an object’s position. The presented exemplary solution of such a system draws attention to the possible problems associated with the use of appropriate technology, sensors, and devices or with a complete navigation system. The position and spatial orientation errors of the measurement platform influence on the obtained SAR imaging. Both, turbulences and maneuvers performed during flight cause the changes in the position of the airborne object resulting in deterioration or lack of images from SAR. Consequently, it is necessary to perform operations for reducing or eliminating the impact of the sensors’ errors on the UAV position accuracy. You need to look for compromise solutions between newer better technologies and in the field of software. Keywords: navigation systems, unmanned aerial vehicles, sensors integration

Enabling UAV Navigation with Sensor and Environmental Uncertainty in Cluttered and GPS-Denied Environments

Directory of Open Access Journals (Sweden)

Fernando Vanegas

2016-05-01

Full Text Available Unmanned Aerial Vehicles (UAV can navigate with low risk in obstacle-free environments using ground control stations that plan a series of GPS waypoints as a path to follow. This GPS waypoint navigation does however become dangerous in environments where the GPS signal is faulty or is only present in some places and when the airspace is filled with obstacles. UAV navigation then becomes challenging because the UAV uses other sensors, which in turn generate uncertainty about its localisation and motion systems, especially if the UAV is a low cost platform. Additional uncertainty affects the mission when the UAV goal location is only partially known and can only be discovered by exploring and detecting a target. This navigation problem is established in this research as a Partially-Observable Markov Decision Process (POMDP, so as to produce a policy that maps a set of motion commands to belief states and observations. The policy is calculated and updated on-line while flying with a newly-developed system for UAV Uncertainty-Based Navigation (UBNAV, to navigate in cluttered and GPS-denied environments using observations and executing motion commands instead of waypoints. Experimental results in both simulation and real flight tests show that the UAV finds a path on-line to a region where it can explore and detect a target without colliding with obstacles. UBNAV provides a new method and an enabling technology for scientists to implement and test UAV navigation missions with uncertainty where targets must be detected using on-line POMDP in real flight scenarios.

Enabling UAV Navigation with Sensor and Environmental Uncertainty in Cluttered and GPS-Denied Environments.

Science.gov (United States)

Vanegas, Fernando; Gonzalez, Felipe

2016-05-10

Unmanned Aerial Vehicles (UAV) can navigate with low risk in obstacle-free environments using ground control stations that plan a series of GPS waypoints as a path to follow. This GPS waypoint navigation does however become dangerous in environments where the GPS signal is faulty or is only present in some places and when the airspace is filled with obstacles. UAV navigation then becomes challenging because the UAV uses other sensors, which in turn generate uncertainty about its localisation and motion systems, especially if the UAV is a low cost platform. Additional uncertainty affects the mission when the UAV goal location is only partially known and can only be discovered by exploring and detecting a target. This navigation problem is established in this research as a Partially-Observable Markov Decision Process (POMDP), so as to produce a policy that maps a set of motion commands to belief states and observations. The policy is calculated and updated on-line while flying with a newly-developed system for UAV Uncertainty-Based Navigation (UBNAV), to navigate in cluttered and GPS-denied environments using observations and executing motion commands instead of waypoints. Experimental results in both simulation and real flight tests show that the UAV finds a path on-line to a region where it can explore and detect a target without colliding with obstacles. UBNAV provides a new method and an enabling technology for scientists to implement and test UAV navigation missions with uncertainty where targets must be detected using on-line POMDP in real flight scenarios.

Optimization of an Intelligent Controller for an Unmanned Underwater Vehicle

Directory of Open Access Journals (Sweden)

M. Fauzi Nor Shah

2011-08-01

Full Text Available Underwater environment poses a difficult challenge for autonomous underwater navigation. A standard problem of underwater vehicles is to maintain it position at a certain depth in order to perform desired operations. An effective controller is required for this purpose and hence the design of a depth controller for an unmanned underwater vehicle is described in this paper. The control algorithm is simulated by using the marine guidance navigation and control simulator. The project shows a radial basis function metamodel can be used to tune the scaling factors of a fuzzy logic controller. By using offline optimization approach, a comparison between genetic algorithm and metamodeling has been done to minimize the integral square error between the set point and the measured depth of the underwater vehicle. The results showed that it is possible to obtain a reasonably good error using metamodeling approach in much a shorter time compared to the genetic algorithm approach.

Sensor Architecture and Task Classification for Agricultural Vehicles and Environments

Directory of Open Access Journals (Sweden)

Francisco Rovira-Más

2010-12-01

Full Text Available The long time wish of endowing agricultural vehicles with an increasing degree of autonomy is becoming a reality thanks to two crucial facts: the broad diffusion of global positioning satellite systems and the inexorable progress of computers and electronics. Agricultural vehicles are currently the only self-propelled ground machines commonly integrating commercial automatic navigation systems. Farm equipment manufacturers and satellite-based navigation system providers, in a joint effort, have pushed this technology to unprecedented heights; yet there are many unresolved issues and an unlimited potential still to uncover. The complexity inherent to intelligent vehicles is rooted in the selection and coordination of the optimum sensors, the computer reasoning techniques to process the acquired data, and the resulting control strategies for automatic actuators. The advantageous design of the network of onboard sensors is necessary for the future deployment of advanced agricultural vehicles. This article analyzes a variety of typical environments and situations encountered in agricultural fields, and proposes a sensor architecture especially adapted to cope with them. The strategy proposed groups sensors into four specific subsystems: global localization, feedback control and vehicle pose, non-visual monitoring, and local perception. The designed architecture responds to vital vehicle tasks classified within three layers devoted to safety, operative information, and automatic actuation. The success of this architecture, implemented and tested in various agricultural vehicles over the last decade, rests on its capacity to integrate redundancy and incorporate new technologies in a practical way.

Easy 3D Mapping for Indoor Navigation of Micro UAVs

DEFF Research Database (Denmark)

Schiøler, Henrik; Totu, Luminita Cristiana; La Cour-Harbo, Anders

2017-01-01

Indoor operation of micro air vehicles (UAS or UAV) is significantly simplified with the availability of some means for indoor localization as well as a sufficiently precise 3D map of the facility. Creation of 3D maps based on the available architectural information should on the one hand provide...... a map of sufficient precision and on the other limit complexity to a manageable level. This paper presents a box based approach for easy generation 3D maps to serve as the basis for indoor navigation of UAS. The basic building block employed is a 3D axis parallel box (APB). Unions of APBs constitute...... with arguments for pivotal design choices and a selection of examples....

Design and Flight Performance of the Orion Pre-Launch Navigation System

Science.gov (United States)

Zanetti, Renato

2016-01-01

Launched in December 2014 atop a Delta IV Heavy from the Kennedy Space Center, the Orion vehicle's Exploration Flight Test-1 (EFT-1) successfully completed the objective to test the prelaunch and entry components of the system. Orion's pre-launch absolute navigation design is presented, together with its EFT-1 performance.

AI technology and automobile. ; Toward vehicle autonomy. AI gijutsu to jidosha. ; Sharyo no jiritsuka ni mukatte

Energy Technology Data Exchange (ETDEWEB)

Okuno, A. (Mazda Motor Corp., Hiroshima (Japan))

1991-01-01

This report describes the vehicle autonomy by using artificial intelligence (AI) technology. Owing to a remarkable progress of AI technology, it is forecasted that driving support system will be introduced into the market till 2000, and higher autonomous navigation system will be introduced since about 2010. Autonomous vehicles have capacities of recognizing the outside world and of navigating roads by themselves, and with their enfanced environment adaptability the road transportation in the future is expected to be much more safer than in the present. The autonomous vehicle can warn its driver of potential dangers and correct operational errors of the driver. In order to realize such autonomous vehicles, extensive researches on perception systems, decision making systems and driving support systems are needed. 9 refs., 10 figs., 1 tab.

A Cockpit Comfort Level of the Descent Capsule-Shaped Vehicles

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V. E. Minenko

2017-01-01

Full Text Available The article formulates the task of selecting a design-layout pattern for a transport spacecraft, in terms of reaching a proper comfort level for the crew to have appropriate functioning. Using the example of a domestic spacecraft and an American one, it has been shown that the type of launch vehicle, the launch specifics, the operational overloads, and the overall mass restrictions have a dramatic impact on the choice of the design-layout pattern of the spacecraft. The free volume of the pressure cockpit per each member of the crew is considered as the main characteristic to show a level of the spacecraft comfort. Using the average statistical data on the layout density of different equipment, the article estimates the possible increase of this characteristic for the cutting-edge descent vehicles. Using the example of the descent vehicles of Soyuz and Apollo class, the article shows a dependence of the raising weight of a descent vehicle on the free volume of its pressure cockpit. Attention is drawn to the fact that the limit of increasing free space of the spacecraft compartments to achieve maximum comfort should correspond to a set of functions that the crew performs in the compartments considered. Otherwise, the increase in the spacecraft mass will prove to be unjustified. The results stated in the article can be useful to developers of manned spacecraft, as well as to teachers and students. In the long term it is worthwhile adding the article material with the mass and volume indicators, as well as with the estimate results of the comfort level of modern manned spacecrafts being under design in Russia and USA, such as PTK NP (“Federation”, “Orion”, “Dragon V2”.

Concept of intellectual charging system for electrical and plug-in hybrid vehicles in Russian Federation

Science.gov (United States)

Kolbasov, A.; Karpukhin, K.; Terenchenko, A.; Kavalchuk, I.

2018-02-01

Electric vehicles have become the most common solution to improve sustainability of the transportation systems all around the world. Despite all benefits, wide adaptation of electric vehicles requires major changes in the infrastructure, including grid adaptation to the rapidly increased power demand and development of the Connected Car concept. This paper discusses the approaches to improve usability of electric vehicles, by creating suitable web-services, with possible connections vehicle-to-vehicle, vehicle-to-infrastructure, and vehicle-to-grid. Developed concept combines information about electrical loads on the grid in specific direction, navigation information from the on-board system, existing and empty charging slots and power availability. In addition, this paper presents the universal concept of the photovoltaic integrated charging stations, which are connected to the developed information systems. It helps to achieve rapid adaptation of the overall infrastructure to the needs of the electric vehicles users with minor changes in the existing grid and loads.

Aspect-dependent radiated noise analysis of an underway autonomous underwater vehicle.

Science.gov (United States)

Gebbie, John; Siderius, Martin; Allen, John S

2012-11-01

This paper presents an analysis of the acoustic emissions emitted by an underway REMUS-100 autonomous underwater vehicle (AUV) that were obtained near Honolulu Harbor, HI using a fixed, bottom-mounted horizontal line array (HLA). Spectral analysis, beamforming, and cross-correlation facilitate identification of independent sources of noise originating from the AUV. Fusion of navigational records from the AUV with acoustic data from the HLA allows for an aspect-dependent presentation of calculated source levels of the strongest propulsion tone.

Performance Enhancement of Land Vehicle Positioning Using Multiple GPS Receivers in an Urban Area

OpenAIRE

Song, Jong-Hwa; Jee, Gyu-In

2016-01-01

The Global Positioning System (GPS) is the most widely used navigation system in land vehicle applications. In urban areas, the GPS suffers from insufficient signal strength, multipath propagation and non-line-of-sight (NLOS) errors, so it thus becomes difficult to obtain accurate and reliable position information. In this paper, an integration algorithm for multiple receivers is proposed to enhance the positioning performance of GPS for land vehicles in urban areas. The pseudoranges of multi...

GPS/DR Error Estimation for Autonomous Vehicle Localization

Directory of Open Access Journals (Sweden)

Byung-Hyun Lee

2015-08-01

Full Text Available Autonomous vehicles require highly reliable navigation capabilities. For example, a lane-following method cannot be applied in an intersection without lanes, and since typical lane detection is performed using a straight-line model, errors can occur when the lateral distance is estimated in curved sections due to a model mismatch. Therefore, this paper proposes a localization method that uses GPS/DR error estimation based on a lane detection method with curved lane models, stop line detection, and curve matching in order to improve the performance during waypoint following procedures. The advantage of using the proposed method is that position information can be provided for autonomous driving through intersections, in sections with sharp curves, and in curved sections following a straight section. The proposed method was applied in autonomous vehicles at an experimental site to evaluate its performance, and the results indicate that the positioning achieved accuracy at the sub-meter level.

The effect of industrial vehicles on the road’s level of service of industrial area in Malang City

Science.gov (United States)

Agustin, I. W.; Sumantri, Y.

2017-06-01

Malang was a great city that has the characteristics of diverse industries and it was spread in each district. Industry was one of the activities that have the characteristics of the movement with the goal of shipping and distribution. The vehicles used are large vehicles such as trucks and trailers. Problems related to the road’s performance that is the emergence of several points of delay and congestion due to the movement and the volume of vehicles as well as the limited capacity of existing roads. It encourages researchers to do research related to the effect of the industrial vehicle movements on the performance of existing roads in the city of Malang. The main purpose of the research is to analyze the effect of industrial vehicles movement on the road’s level of service of industrial area and to find out alternative solutions to improve the road’s level of service of industrial area. The research used multiple linear regression and do something analysis. The results showed that the types of industry in the city of Malang are ILMETTA, IATT, Agrokim, Sentra and Large Industries. Determining the location of the main observation based on the distribution of industry, have a major impact directly on the street, and the class of the national road are located in Sunandar Priyo Sudarmo Street. Existing land use in Sunandar Priyo Sudarmo Street are industrial, healthcare, office and it dominated by trade and services. Related to the variables that affect the movement of industrial vehicles are the number of employees (X3) and the delivery frequency (X6). The road’s level of service of Sunandar Priyo Sudarmo Street are D and E. While the effect of industrial vehicles movement on the road’s level of service which ranged from 13.77 per cent to 22.13 per cent of the total volume of vehicles on the road. Some referrals will be used to handle the problems that the road widening and the selection of alternative routes for the industrial vehicles.

Fundamentals of Inertial Navigation, Satellite-based Positioning and their Integration

CERN Document Server

Noureldin, Aboelmagd; Georgy, Jacques

2013-01-01

Fundamentals of Inertial Navigation, Satellite-based Positioning and their Integration is an introduction to the field of Integrated Navigation Systems. It serves as an excellent reference for working engineers as well as textbook for beginners and students new to the area. The book is easy to read and understand with minimum background knowledge. The authors explain the derivations in great detail. The intermediate steps are thoroughly explained so that a beginner can easily follow the material. The book shows a step-by-step implementation of navigation algorithms and provides all the necessary details. It provides detailed illustrations for an easy comprehension. The book also demonstrates real field experiments and in-vehicle road test results with professional discussions and analysis. This work is unique in discussing the different INS/GPS integration schemes in an easy to understand and straightforward way. Those schemes include loosely vs tightly coupled, open loop vs closed loop, and many more.

3D photo mosaicing of Tagiri shallow vent field by an autonomous underwater vehicle (3rd report) - Mosaicing method based on navigation data and visual features -

Science.gov (United States)

Maki, Toshihiro; Ura, Tamaki; Singh, Hanumant; Sakamaki, Takashi

Large-area seafloor imaging will bring significant benefits to various fields such as academics, resource survey, marine development, security, and search-and-rescue. The authors have proposed a navigation method of an autonomous underwater vehicle for seafloor imaging, and verified its performance through mapping tubeworm colonies with the area of 3,000 square meters using the AUV Tri-Dog 1 at Tagiri vent field, Kagoshima bay in Japan (Maki et al., 2008, 2009). This paper proposes a post-processing method to build a natural photo mosaic from a number of pictures taken by an underwater platform. The method firstly removes lens distortion, invariances of color and lighting from each image, and then ortho-rectification is performed based on camera pose and seafloor estimated by navigation data. The image alignment is based on both navigation data and visual characteristics, implemented as an expansion of the image based method (Pizarro et al., 2003). Using the two types of information realizes an image alignment that is consistent both globally and locally, as well as making the method applicable to data sets with little visual keys. The method was evaluated using a data set obtained by the AUV Tri-Dog 1 at the vent field in Sep. 2009. A seamless, uniformly illuminated photo mosaic covering the area of around 500 square meters was created from 391 pictures, which covers unique features of the field such as bacteria mats and tubeworm colonies.

The UAV take-off and landing system used for small areas of mobile vehicles

Science.gov (United States)

Ren, Tian-Yu; Duanmu, Qing-Duo; Wu, Bo-Qi

2018-03-01

In order to realize an UAV formation cluster system based on the current GPS and the fault and insufficiency of Beidou integrated navigation system in strong jamming environment. Due to the impact of the compass on the plane crash, navigation system error caused by the mobile area to help reduce the need for large landing sites and not in the small fast moving area to achieve the reality of the landing. By using Strapdown inertial and all-optical system to form Composite UAV flight control system, the photoelectric composite strapdown inertial coupling is realized, and through the laser and microwave telemetry link compound communication mechanism, using all-optical strapdown inertial and visual navigation system to solve the deviation of take-off and landing caused by electromagnetic interference, all-optical bidirectional data link realizes two-way position correction of landing site and aircraft, thus achieves the accurate recovery of UAV formation cluster in the mobile narrow area which the traditional navigation system can't realize. This system is a set of efficient unmanned aerial vehicle Group Take-off/descending system, which is suitable for many tasks, and not only realizes the reliable continuous navigation under the complex electromagnetic interference environment, moreover, the intelligent flight and Take-off and landing of unmanned aerial vehicles relative to the fast moving and small recovery sites in complex electromagnetic interference environment can not only improve the safe operation rate of unmanned aerial vehicle, but also guarantee the operation safety of the aircraft, and the more has important social value for the application foreground of the aircraft.

The use of x-ray pulsar-based navigation method for interplanetary flight

Science.gov (United States)

Yang, Bo; Guo, Xingcan; Yang, Yong

2009-07-01

As interplanetary missions are increasingly complex, the existing unique mature interplanetary navigation method mainly based on radiometric tracking techniques of Deep Space Network can not meet the rising demands of autonomous real-time navigation. This paper studied the applications for interplanetary flights of a new navigation technology under rapid development-the X-ray pulsar-based navigation for spacecraft (XPNAV), and valued its performance with a computer simulation. The XPNAV is an excellent autonomous real-time navigation method, and can provide comprehensive navigation information, including position, velocity, attitude, attitude rate and time. In the paper the fundamental principles and time transformation of the XPNAV were analyzed, and then the Delta-correction XPNAV blending the vehicles' trajectory dynamics with the pulse time-of-arrival differences at nominal and estimated spacecraft locations within an Unscented Kalman Filter (UKF) was discussed with a background mission of Mars Pathfinder during the heliocentric transferring orbit. The XPNAV has an intractable problem of integer pulse phase cycle ambiguities similar to the GPS carrier phase navigation. This article innovatively proposed the non-ambiguity assumption approach based on an analysis of the search space array method to resolve pulse phase cycle ambiguities between the nominal position and estimated position of the spacecraft. The simulation results show that the search space array method are computationally intensive and require long processing time when the position errors are large, and the non-ambiguity assumption method can solve ambiguity problem quickly and reliably. It is deemed that autonomous real-time integrated navigation system of the XPNAV blending with DSN, celestial navigation, inertial navigation and so on will be the development direction of interplanetary flight navigation system in the future.

Towards Safe Navigation by Formalizing Navigation Rules

Directory of Open Access Journals (Sweden)

Arne Kreutzmann

2013-06-01

Full Text Available One crucial aspect of safe navigation is to obey all navigation regulations applicable, in particular the collision regulations issued by the International Maritime Organization (IMO Colregs. Therefore, decision support systems for navigation need to respect Colregs and this feature should be verifiably correct. We tackle compliancy of navigation regulations from a perspective of software verification. One common approach is to use formal logic, but it requires to bridge a wide gap between navigation concepts and simple logic. We introduce a novel domain specification language based on a spatio-temporal logic that allows us to overcome this gap. We are able to capture complex navigation concepts in an easily comprehensible representation that can direcly be utilized by various bridge systems and that allows for software verification.

A Global Navigation Management Architecture Applied to Autonomous Robots in Urban Environments

OpenAIRE

Kenmogne , Ide-Flore; Alves De Lima , Danilo; Corrêa Victorino , Alessandro

2015-01-01

International audience; This paper presents a global behavioral architecture used as a coordinator for the global navigation of an autonomous vehicle in an urban context including traffic laws and other features. As an extension to our previous work, the approach presented here focuses on how this manager uses perceived information (from low cost cameras and laser scanners) combined with digital road-map data to take decisions. This decision consists in retrieving the car's state regarding th...

Assessing risk of navigational hazard from sea-level-related datum in the South West of Java Sea, Indonesia

Science.gov (United States)

Poerbandono

2017-07-01

This paper assesses the presence of navigational hazards due to underestimation of charted depths originated from an establishment of a sea-level-related reference plane, i.e. datum. The study domain is situated in one of Indonesia's densest marine traffic, SW Java Sea, Indonesia. The assessment is based on the comparison of the authorized Chart Datum (CD), being uniformly located at 0.6 m below Mean Sea Level (MSL), and a spatially varying Lowest Astronomical Tide (LAT) generated for the purpose of this research. Hazards are considered here as the deviation of LAT from CD and quantified as the ratio of LAT -CD deviation with respect to the allowable Total Vertical Uncertainty (TVU), i.e. the international standard for accuracy of depth information on nautical charts. Underestimation of charted depth is expected for the case that LAT falls below CD. Such a risk magnifies with decreasing depths, as well as the increasing volume of traffic and draught of the vessel. It is found that most of the domain is in the interior of risk-free zone from using uniform CD. As much as 0.08 and 0.19 parts of the area are in zones where the uncertainty of CD contributes respectively to 50% and 30% of Total Vertical Uncertainty. These are zones where the hazard of navigation is expected to increase due to underestimated lowest tidal level.

A Novel Vehicle Stationary Detection Utilizing Map Matching and IMU Sensors

Directory of Open Access Journals (Sweden)

Md. Syedul Amin

2014-01-01

Full Text Available Precise navigation is a vital need for many modern vehicular applications. The global positioning system (GPS cannot provide continuous navigation information in urban areas. The widely used inertial navigation system (INS can provide full vehicle state at high rates. However, the accuracy diverges quickly in low cost microelectromechanical systems (MEMS based INS due to bias, drift, noise, and other errors. These errors can be corrected in a stationary state. But detecting stationary state is a challenging task. A novel stationary state detection technique from the variation of acceleration, heading, and pitch and roll of an attitude heading reference system (AHRS built from the inertial measurement unit (IMU sensors is proposed. Besides, the map matching (MM algorithm detects the intersections where the vehicle is likely to stop. Combining these two results, the stationary state is detected with a smaller timing window of 3 s. A longer timing window of 5 s is used when the stationary state is detected only from the AHRS. The experimental results show that the stationary state is correctly identified and the position error is reduced to 90% and outperforms previously reported work. The proposed algorithm would help to reduce INS errors and enhance the performance of the navigation system.

Relative navigation and attitude determination using a GPS/INS integrated system near the International Space Station

Science.gov (United States)

Um, Jaeyong

2001-08-01

The Space Integrated GPS/INS (SIGI) sensor is the primary navigation and attitude determination source for the International Space Station (ISS). The SIGI was successfully demonstrated on-orbit for the first time in the SIGI Orbital Attitude Readiness (SOAR) demonstration on the Space Shuttle Atlantis in May 2000. Numerous proximity operations near the ISS have been and will be performed over the lifetime of the Station. The development of an autonomous relative navigation system is needed to improve the safety and efficiency of vehicle operations near the ISS. A hardware simulation study was performed for the GPS-based relative navigation using the state vector difference approach and the interferometric approach in the absence of multipath. The interferometric approach, where the relative states are estimated directly, showed comparable results for a 1 km baseline. One of the most pressing current technical issues is the design of an autonomous relative navigation system in the proximity of the ISS, where GPS signals are blocked and maneuvers happen frequently. An integrated GPS/INS system is investigated for the possibility of a fully autonomous relative navigation system. Another application of GPS measurements is determination of the vehicle's orientation in space. This study used the SOAR experiment data to characterize the SICI's on-orbit performance for attitude determination. A cold start initialization algorithm was developed for integer ambiguity resolution in any initial orientation. The original algorithm that was used in the SIGI had an operational limitation in the integer ambiguity resolution, which was developed for terrestrial applications, and limited its effectiveness in space. The new algorithm was tested using the SOAR data and has been incorporated in the current SIGI flight software. The attitude estimation performance was examined using two different GPS/INS integration algorithms. The GPS/INS attitude solution using the SOAR data was as

Cooperative control of a squad of mobile vehicles

International Nuclear Information System (INIS)

Lewis, C.; Feddema, J.; Klarer, P.

1998-01-01

Tasks such as the localization of chemical sources, demining, perimeter control, surveillance and search and rescue missions are usually performed by teams of people. At least conceptually, large groups of relatively cheap mobile vehicles outfitted with sensors should be able to automatically accomplish some of these tasks. Sandia National Labs is currently developing a swarm of semi-autonomous all terrain vehicles for remote cooperative sensing applications. This paper will describe the capabilities of this system and outline some of its possible applications. Cooperative control and sensing strategies will also be described. Eight Roving All Terrain Lunar Explorer Rovers (RATLERs) have been built at Sandia as a test platform for cooperative control and sensing applications. This paper will first describe the hardware capabilities of the RATLER system. Then it will describe the basic control algorithm for GPS based navigation and obstacle avoidance. A higher level cooperative control task will then be described

Navigation Problems in Blind-to-Blind Pedestrians Tele-assistance Navigation

OpenAIRE

Balata , Jan; Mikovec , Zdenek; Maly , Ivo

2015-01-01

International audience; We raise a question whether it is possible to build a large-scale navigation system for blind pedestrians where a blind person navigates another blind person remotely by mobile phone. We have conducted an experiment, in which we observed blind people navigating each other in a city center in 19 sessions. We focused on problems in the navigator’s attempts to direct the traveler to the destination. We observed 96 problems in total, classified them on the basis of the typ...

Mapping and navigating transitions - The multi-level perspective compared with arenas of development

DEFF Research Database (Denmark)

Jørgensen, Ulrik

2012-01-01

actors to navigate. The second concern builds on the observation that actors engage at all levels in society including visions, institutions, and innovations. The third concern addresses the role of academic theories and advice regarding governance of transition processes in which they function......Transitions of socio-technical systems imply the reconfiguration of institutions and politics making made evident the need to understand and intervene in existing patterns of growth and socio-technical practices in more sustainable directions. In recent decades, theories of transitions have been...... introduced, which include the multi-level approach indicating ways to govern transitions through understanding the interactions between niches, regimes and landscapes. An alternative approach is suggested, which takes its outset in arenas of development and increased awareness of actors and their way...

Powertrain Component Inspection from Mid-Level Blends Vehicle Aging Study

Energy Technology Data Exchange (ETDEWEB)

Shoffner, Brent [Southwest Research Institute, San Antonio; Johnson, Ryan [Southwest Research Institute, San Antonio; Heimrich, Martin J. [Southwest Research Institute, San Antonio; Lochte, Michael [Southwest Research Institute, San Antonio

2010-11-01

The Energy Independence and Security Act of 2007 calls on the nation to significantly increase its use of renewable fuels to meet its transportation energy needs. The law expands the renewable fuel standard to require use of 36 billion gallons of renewable fuel by 2022. Given that ethanol is the most widely used renewable fuel in the U.S. market, ethanol will likely make up a significant portion of the 36-billion-gallon requirement. The vast majority of ethanol used in the United States is blended with gasoline to create E10-gasoline with up to 10% ethanol. The remaining ethanol is sold in the form of E85 - a gasoline blend with as much as 85% ethanol that can only be used in flexible-fuel vehicles (FFVs). Consumption of E85 is at present limited by both the size of the FFV fleet and the number of E85 fueling stations. Gasoline consumption in the United States is currently about 140 billion gallons per year; thus the maximum use of ethanol as E10 is only about 14 billion gallons. While the U.S. Department of Energy (DOE) remains committed to expanding the E85 infrastructure, that market represented less than 1% of the ethanol consumed in 2010 and will not be able to absorb projected volumes of ethanol in the near term. Because of these factors, DOE and others have been assessing the viability of using mid-level ethanol blends (E15 or E20) as a way to accommodate growing volumes of ethanol. The DOE Mid-Level Ethanol Blends Test Program has been under way since 2007, supported jointly by the Office of the Biomass Program and the Vehicle Technologies Program. One of the larger projects, the Catalyst Durability Study, or Vehicle Aging Study, will be completed early in calendar year 2011. The following report describes a subproject of the Vehicle Aging Study in which powertrain components from 18 of the vehicles were examined at Southwest Research Institute under contract to Oak Ridge National Laboratory (ORNL).

Group-level variations in motor representation areas of thenar and anterior tibial muscles: Navigated Transcranial Magnetic Stimulation Study.

Science.gov (United States)

Niskanen, Eini; Julkunen, Petro; Säisänen, Laura; Vanninen, Ritva; Karjalainen, Pasi; Könönen, Mervi

2010-08-01

Navigated transcranial magnetic stimulation (TMS) can be used to stimulate functional cortical areas at precise anatomical location to induce measurable responses. The stimulation has commonly been focused on anatomically predefined motor areas: TMS of that area elicits a measurable muscle response, the motor evoked potential. In clinical pathologies, however, the well-known homunculus somatotopy theory may not be straightforward, and the representation area of the muscle is not fixed. Traditionally, the anatomical locations of TMS stimulations have not been reported at the group level in standard space. This study describes a methodology for group-level analysis by investigating the normal representation areas of thenar and anterior tibial muscle in the primary motor cortex. The optimal representation area for these muscles was mapped in 59 healthy right-handed subjects using navigated TMS. The coordinates of the optimal stimulation sites were then normalized into standard space to determine the representation areas of these muscles at the group-level in healthy subjects. Furthermore, 95% confidence interval ellipsoids were fitted into the optimal stimulation site clusters to define the variation between subjects in optimal stimulation sites. The variation was found to be highest in the anteroposterior direction along the superior margin of the precentral gyrus. These results provide important normative information for clinical studies assessing changes in the functional cortical areas because of plasticity of the brain. Furthermore, it is proposed that the presented methodology to study TMS locations at the group level on standard space will be a suitable tool for research purposes in population studies. 2010 Wiley-Liss, Inc.

Bio-inspired computation in unmanned aerial vehicles

CERN Document Server

Duan, Haibin

2014-01-01

Bio-inspired Computation in Unmanned Aerial Vehicles focuses on the aspects of path planning, formation control, heterogeneous cooperative control and vision-based surveillance and navigation in Unmanned Aerial Vehicles (UAVs) from the perspective of bio-inspired computation. It helps readers to gain a comprehensive understanding of control-related problems in UAVs, presenting the latest advances in bio-inspired computation. By combining bio-inspired computation and UAV control problems, key questions are explored in depth, and each piece is content-rich while remaining accessible. With abundant illustrations of simulation work, this book links theory, algorithms and implementation procedures, demonstrating the simulation results with graphics that are intuitive without sacrificing academic rigor. Further, it pays due attention to both the conceptual framework and the implementation procedures. The book offers a valuable resource for scientists, researchers and graduate students in the field of Control, Aeros...

Vision/INS Integrated Navigation System for Poor Vision Navigation Environments

Directory of Open Access Journals (Sweden)

Youngsun Kim

2016-10-01

Full Text Available In order to improve the performance of an inertial navigation system, many aiding sensors can be used. Among these aiding sensors, a vision sensor is of particular note due to its benefits in terms of weight, cost, and power consumption. This paper proposes an inertial and vision integrated navigation method for poor vision navigation environments. The proposed method uses focal plane measurements of landmarks in order to provide position, velocity and attitude outputs even when the number of landmarks on the focal plane is not enough for navigation. In order to verify the proposed method, computer simulations and van tests are carried out. The results show that the proposed method gives accurate and reliable position, velocity and attitude outputs when the number of landmarks is insufficient.

Design of a Control System for an Autonomous Vehicle Based on Adaptive-PID

Directory of Open Access Journals (Sweden)

Pan Zhao

2012-07-01

Full Text Available The autonomous vehicle is a mobile robot integrating multi-sensor navigation and positioning, intelligent decision making and control technology. This paper presents the control system architecture of the autonomous vehicle, called “Intelligent Pioneer”, and the path tracking and stability of motion to effectively navigate in unknown environments is discussed. In this approach, a two degree-of-freedom dynamic model is developed to formulate the path-tracking problem in state space format. For controlling the instantaneous path error, traditional controllers have difficulty in guaranteeing performance and stability over a wide range of parameter changes and disturbances. Therefore, a newly developed adaptive-PID controller will be used. By using this approach the flexibility of the vehicle control system will be increased and achieving great advantages. Throughout, we provide examples and results from Intelligent Pioneer and the autonomous vehicle using this approach competed in the 2010 and 2011 Future Challenge of China. Intelligent Pioneer finished all of the competition programmes and won first position in 2010 and third position in 2011.

Traffic control and intelligent vehicle highway systems: a survey

NARCIS (Netherlands)

Baskar, L.D.; Schutter, B. de; Hellendoorn, J.; Papp, Z.

2011-01-01

Traffic congestion in highway networks is one of the main issues to be addressed by today's traffic management schemes. Automation combined with the increasing market penetration of on-line communication, navigation and advanced driver assistance systems will ultimately result in intelligent vehicle

Vision-Aided Autonomous Landing and Ingress of Micro Aerial Vehicles

Science.gov (United States)

Brockers, Roland; Ma, Jeremy C.; Matthies, Larry H.; Bouffard, Patrick

2012-01-01

Micro aerial vehicles have limited sensor suites and computational power. For reconnaissance tasks and to conserve energy, these systems need the ability to autonomously land at vantage points or enter buildings (ingress). But for autonomous navigation, information is needed to identify and guide the vehicle to the target. Vision algorithms can provide egomotion estimation and target detection using input from cameras that are easy to include in miniature systems.

The Design of a Navigator for a Testbed Autonomous Underwater Vehicle

Science.gov (United States)

1989-12-01

AD-A231 733 NAVAL POSTGRADUATE SCHOOL Monterey, California DTC C ’S B’- i I A VDI ELECTE 1i EB 0 6 991| D THESIS E THE DESIGN OF A NAVIGATOR FOR A...255,255,0); /* yellow (512-1023) * for (i= 1024; i< 2048 ; ++i) mapcolor(i,255 ,0,255); 1* magenta (1024-2047 )*/ color(BLACK); clearo; swapbufferso; 1

46 CFR 122.340 - Vessels carrying vehicles.

Science.gov (United States)

2010-10-01

... vehicles freely in the event of fire or other disaster. The decks, where necessary, must be distinctly... their emergency brakes set when the vessel is underway, and that the motors are not started until the... loading ramp must have its wheels securely blocked, while the vessel is being navigated. (c) The master...

Probe data from consumer GPS navigation devices for the analysis of controlled intersections

NARCIS (Netherlands)

Van Arem, B.; Salomons, A.M.; Krootjes, P.; Cohn, N.; Meijer, A.

2012-01-01

Probe data from consumer GPS navigation devices provides a network-wide and costefficient data source for measuring vehicle movements, whereas experimental studies have been confined to small datasets. Data collection from road-side sensors can provide similar information but is expensive and

Robust localisation of automated guided vehicles for computer-integrated manufacturing environments

Directory of Open Access Journals (Sweden)

Dixon, R. C.

2013-05-01

Full Text Available As industry moves toward an era of complete automation and mass customisation, automated guided vehicles (AGVs are used as material handling systems. However, the current techniques that provide navigation, control, and manoeuvrability of automated guided vehicles threaten to create bottlenecks and inefficiencies in manufacturing environments that strive towards the optimisation of part production. This paper proposes a decentralised localisation technique for an automated guided vehicle without any non-holonomic constraints. Incorporation of these vehicles into the material handling system of a computer-integrated manufacturing environment would increase the characteristics of robustness, efficiency, flexibility, and advanced manoeuvrability.

Sensor fusion for mobile robot navigation

International Nuclear Information System (INIS)

Kam, M.; Zhu, X.; Kalata, P.

1997-01-01

The authors review techniques for sensor fusion in robot navigation, emphasizing algorithms for self-location. These find use when the sensor suite of a mobile robot comprises several different sensors, some complementary and some redundant. Integrating the sensor readings, the robot seeks to accomplish tasks such as constructing a map of its environment, locating itself in that map, and recognizing objects that should be avoided or sought. The review describes integration techniques in two categories: low-level fusion is used for direct integration of sensory data, resulting in parameter and state estimates; high-level fusion is used for indirect integration of sensory data in hierarchical architectures, through command arbitration and integration of control signals suggested by different modules. The review provides an arsenal of tools for addressing this (rather ill-posed) problem in machine intelligence, including Kalman filtering, rule-based techniques, behavior based algorithms and approaches that borrow from information theory, Dempster-Shafer reasoning, fuzzy logic and neural networks. It points to several further-research needs, including: robustness of decision rules; simultaneous consideration of self-location, motion planning, motion control and vehicle dynamics; the effect of sensor placement and attention focusing on sensor fusion; and adaptation of techniques from biological sensor fusion

EXPERIENCES WITH ACQUIRING HIGHLY REDUNDANT SPATIAL DATA TO SUPPORT DRIVERLESS VEHICLE TECHNOLOGIES

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Z. Koppanyi

2018-05-01

Full Text Available As vehicle technology is moving towards higher autonomy, the demand for highly accurate geospatial data is rapidly increasing, as accurate maps have a huge potential of increasing safety. In particular, high definition 3D maps, including road topography and infrastructure, as well as city models along the transportation corridors represent the necessary support for driverless vehicles. In this effort, a vehicle equipped with high-, medium- and low-resolution active and passive cameras acquired data in a typical traffic environment, represented here by the OSU campus, where GPS/GNSS data are available along with other navigation sensor data streams. The data streams can be used for two purposes. First, high-definition 3D maps can be created by integrating all the sensory data, and Data Analytics/Big Data methods can be tested for automatic object space reconstruction. Second, the data streams can support algorithmic research for driverless vehicle technologies, including object avoidance, navigation/positioning, detecting pedestrians and bicyclists, etc. Crucial cross-performance analyses on map database resolution and accuracy with respect to sensor performance metrics to achieve economic solution for accurate driverless vehicle positioning can be derived. These, in turn, could provide essential information on optimizing the choice of geospatial map databases and sensors’ quality to support driverless vehicle technologies. The paper reviews the data acquisition and primary data processing challenges and performance results.

Experiences with Acquiring Highly Redundant Spatial Data to Support Driverless Vehicle Technologies

Science.gov (United States)

Koppanyi, Z.; Toth, C. K.

2018-05-01

As vehicle technology is moving towards higher autonomy, the demand for highly accurate geospatial data is rapidly increasing, as accurate maps have a huge potential of increasing safety. In particular, high definition 3D maps, including road topography and infrastructure, as well as city models along the transportation corridors represent the necessary support for driverless vehicles. In this effort, a vehicle equipped with high-, medium- and low-resolution active and passive cameras acquired data in a typical traffic environment, represented here by the OSU campus, where GPS/GNSS data are available along with other navigation sensor data streams. The data streams can be used for two purposes. First, high-definition 3D maps can be created by integrating all the sensory data, and Data Analytics/Big Data methods can be tested for automatic object space reconstruction. Second, the data streams can support algorithmic research for driverless vehicle technologies, including object avoidance, navigation/positioning, detecting pedestrians and bicyclists, etc. Crucial cross-performance analyses on map database resolution and accuracy with respect to sensor performance metrics to achieve economic solution for accurate driverless vehicle positioning can be derived. These, in turn, could provide essential information on optimizing the choice of geospatial map databases and sensors' quality to support driverless vehicle technologies. The paper reviews the data acquisition and primary data processing challenges and performance results.

Target Trailing With Safe Navigation for Maritime Autonomous Surface Vehicles

Science.gov (United States)

Wolf, Michael; Kuwata, Yoshiaki; Zarzhitsky, Dimitri V.

2013-01-01

This software implements a motion-planning module for a maritime autonomous surface vehicle (ASV). The module trails a given target while also avoiding static and dynamic surface hazards. When surface hazards are other moving boats, the motion planner must apply International Regulations for Avoiding Collisions at Sea (COLREGS). A key subset of these rules has been implemented in the software. In case contact with the target is lost, the software can receive and follow a "reacquisition route," provided by a complementary system, until the target is reacquired. The programmatic intention is that the trailed target is a submarine, although any mobile naval platform could serve as the target. The algorithmic approach to combining motion with a (possibly moving) goal location, while avoiding local hazards, may be applicable to robotic rovers, automated landing systems, and autonomous airships. The software operates in JPL s CARACaS (Control Architecture for Robotic Agent Command and Sensing) software architecture and relies on other modules for environmental perception data and information on the predicted detectability of the target, as well as the low-level interface to the boat controls.

Comparative field evaluation of vehicle cruise speed and acceleration level impacts on hot stabilized emissions

International Nuclear Information System (INIS)

El-Shawarby, Ihab; Ahn, Kyoungho; Rakha, Hesham

2005-01-01

The main objectives of this paper are two fold. First, the paper evaluates the impact of vehicle cruise speed and acceleration levels on vehicle fuel-consumption and emission rates using field data gathered under real-world driving conditions. Second, it validates the VT-Micro model for the modeling of real-world conditions. Specifically, an on-board emission-measurement device was used to collect emissions of oxides of nitrogen, hydrocarbons, carbon monoxide, and carbon dioxide using a light-duty test vehicle. The analysis demonstrates that vehicle fuel-consumption and emission rates per-unit distance are optimum in the range of 60-90 km/h, with considerable increase outside this optimum range. The study demonstrates that as the level of aggressiveness for acceleration maneuvers increases, the fuel-consumption and emission rates per maneuver decrease because the vehicle spends less time accelerating. However, when emissions are gathered over a sufficiently long fixed distance, fuel-consumption and mobile-source emission rates per-unit distance increase as the level of acceleration increases because of the history effects that accompany rich-mode engine operations. In addition, the paper demonstrates the validity of the VT-Micro framework for modeling steady-state vehicle fuel-consumption and emission behavior. Finally, the research demonstrates that the VT-Micro framework requires further refinement to capture non-steady-state history behavior when the engine operates in rich mode. (Author)

Pilot perception and confidence of location during a simulated helicopter navigation task.

Science.gov (United States)

Yang, Ji Hyun; Cowden, Bradley T; Kennedy, Quinn; Schramm, Harrison; Sullivan, Joseph

2013-09-01

This paper aims to provide insights into human perception, navigation performance, and confidence in helicopter overland navigation. Helicopter overland navigation is a challenging mission area because it is a complex cognitive task, and failing to recognize when the aircraft is off-course can lead to operational failures and mishaps. A human-in-the-loop experiment to investigate pilot perception during simulated overland navigation by analyzing actual navigation trajectory, pilots' perceived location, and corresponding confidence levels was designed. There were 15 military officers with prior overland navigation experience who completed 4 simulated low-level navigation routes, 2 of which entailed auto-navigation. This route was paused roughly every 30 s for the subject to mark their perceived location on the map and their confidence level using a customized program. Analysis shows that there is no correlation between perceived and actual location of the aircraft, nor between confidence level and actual location. There is, however, some evidence that there is a correlation (rho = -0.60 to approximately 0.65) between perceived location and intended route of flight, suggesting that there is a bias toward believing one is on the intended flight route. If aviation personnel can proactively identify the circumstances in which usual misperceptions occur in navigation, they may reduce mission failure and accident rate. Fleet squadrons and instructional commands can benefit from this study to improve operations that require low-level flight while also improving crew resource management.

Spatial environmental analysis on the effects of a new navigation system for freight transport

NARCIS (Netherlands)

Feng, T.; Arentze, T.A.; Timmermans, H.J.P.

2012-01-01

Considerable attention has been paid to traffic pollution modeling for commercial vehicles due to their high amount of nitrogen compounds, particulate matter and greenhouse gas emissions. Conventional navigation systems for passenger cars enable the route choice process. However, commercial route

Spatial filtering self-velocimeter for vehicle application using a CMOS linear image sensor

Science.gov (United States)

He, Xin; Zhou, Jian; Nie, Xiaoming; Long, Xingwu

2015-03-01

The idea of using a spatial filtering velocimeter (SFV) to measure the velocity of a vehicle for an inertial navigation system is put forward. The presented SFV is based on a CMOS linear image sensor with a high-speed data rate, large pixel size, and built-in timing generator. These advantages make the image sensor suitable to measure vehicle velocity. The power spectrum of the output signal is obtained by fast Fourier transform and is corrected by a frequency spectrum correction algorithm. This velocimeter was used to measure the velocity of a conveyor belt driven by a rotary table and the measurement uncertainty is ˜0.54%. Furthermore, it was also installed on a vehicle together with a laser Doppler velocimeter (LDV) to measure self-velocity. The measurement result of the designed SFV is compared with that of the LDV. It is shown that the measurement result of the SFV is coincident with that of the LDV. Therefore, the designed SFV is suitable for a vehicle self-contained inertial navigation system.

MULTI-GNSS RECEIVER FOR AEROSPACE NAVIGATION AND POSITIONING APPLICATIONS

Directory of Open Access Journals (Sweden)

T. R. Peres

2014-03-01

Full Text Available The upcoming Galileo system opens a wide range of new opportunities in the Global Navigation Satellite System (GNSS market. However, the characteristics of the future GNSS signals require the development of new GNSS receivers. In the frame of the REAGE project, DEIMOS and ISEL have developed a GNSS receiver targeted for aerospace applications, supporting current and future GPS L1 and Galileo E1 signals, based on commercial (or, in the furthest extent, industrial grade components. Although the REAGE project aimed at space applications, the REAGE receiver is also applicable to many terrestrial applications (ground or airborne, such as Georeferencing and Unmanned Aerial Vehicle (UAV navigation. This paper presents the architecture and features of the REAGE receiver, as well as some results of the validation campaign with GPS L1 and Galileo E1 signals.

Unified Simulation and Analysis Framework for Deep Space Navigation Design

Science.gov (United States)

Anzalone, Evan; Chuang, Jason; Olsen, Carrie

2013-01-01

As the technology that enables advanced deep space autonomous navigation continues to develop and the requirements for such capability continues to grow, there is a clear need for a modular expandable simulation framework. This tool's purpose is to address multiple measurement and information sources in order to capture system capability. This is needed to analyze the capability of competing navigation systems as well as to develop system requirements, in order to determine its effect on the sizing of the integrated vehicle. The development for such a framework is built upon Model-Based Systems Engineering techniques to capture the architecture of the navigation system and possible state measurements and observations to feed into the simulation implementation structure. These models also allow a common environment for the capture of an increasingly complex operational architecture, involving multiple spacecraft, ground stations, and communication networks. In order to address these architectural developments, a framework of agent-based modules is implemented to capture the independent operations of individual spacecraft as well as the network interactions amongst spacecraft. This paper describes the development of this framework, and the modeling processes used to capture a deep space navigation system. Additionally, a sample implementation describing a concept of network-based navigation utilizing digitally transmitted data packets is described in detail. This developed package shows the capability of the modeling framework, including its modularity, analysis capabilities, and its unification back to the overall system requirements and definition.

Group navigation and the "many-wrongs principle" in models of animal movement.

Science.gov (United States)

Codling, E A; Pitchford, J W; Simpson, S D

2007-07-01

Traditional studies of animal navigation over both long and short distances have usually considered the orientation ability of the individual only, without reference to the implications of group membership. However, recent work has suggested that being in a group can significantly improve the ability of an individual to align toward and reach a target direction or point, even when all group members have limited navigational ability and there are no leaders. This effect is known as the "many-wrongs principle" since the large number of individual navigational errors across the group are suppressed by interactions and group cohesion. In this paper, we simulate the many-wrongs principle using a simple individual-based model of movement based on a biased random walk that includes group interactions. We study the ability of the group as a whole to reach a target given different levels of individual navigation error, group size, interaction radius, and environmental turbulence. In scenarios with low levels of environmental turbulence, simulation results demonstrate a navigational benefit from group membership, particularly for small group sizes. In contrast, when movement takes place in a highly turbulent environment, simulation results suggest that the best strategy is to navigate as individuals rather than as a group.

Fuzzy Adaptive Cubature Kalman Filter for Integrated Navigation Systems.

Science.gov (United States)

Tseng, Chien-Hao; Lin, Sheng-Fuu; Jwo, Dah-Jing

2016-07-26

This paper presents a sensor fusion method based on the combination of cubature Kalman filter (CKF) and fuzzy logic adaptive system (FLAS) for the integrated navigation systems, such as the GPS/INS (Global Positioning System/inertial navigation system) integration. The third-degree spherical-radial cubature rule applied in the CKF has been employed to avoid the numerically instability in the system model. In processing navigation integration, the performance of nonlinear filter based estimation of the position and velocity states may severely degrade caused by modeling errors due to dynamics uncertainties of the vehicle. In order to resolve the shortcoming for selecting the process noise covariance through personal experience or numerical simulation, a scheme called the fuzzy adaptive cubature Kalman filter (FACKF) is presented by introducing the FLAS to adjust the weighting factor of the process noise covariance matrix. The FLAS is incorporated into the CKF framework as a mechanism for timely implementing the tuning of process noise covariance matrix based on the information of degree of divergence (DOD) parameter. The proposed FACKF algorithm shows promising accuracy improvement as compared to the extended Kalman filter (EKF), unscented Kalman filter (UKF), and CKF approaches.

Fuzzy Adaptive Cubature Kalman Filter for Integrated Navigation Systems

Directory of Open Access Journals (Sweden)

Chien-Hao Tseng

2016-07-01

Full Text Available This paper presents a sensor fusion method based on the combination of cubature Kalman filter (CKF and fuzzy logic adaptive system (FLAS for the integrated navigation systems, such as the GPS/INS (Global Positioning System/inertial navigation system integration. The third-degree spherical-radial cubature rule applied in the CKF has been employed to avoid the numerically instability in the system model. In processing navigation integration, the performance of nonlinear filter based estimation of the position and velocity states may severely degrade caused by modeling errors due to dynamics uncertainties of the vehicle. In order to resolve the shortcoming for selecting the process noise covariance through personal experience or numerical simulation, a scheme called the fuzzy adaptive cubature Kalman filter (FACKF is presented by introducing the FLAS to adjust the weighting factor of the process noise covariance matrix. The FLAS is incorporated into the CKF framework as a mechanism for timely implementing the tuning of process noise covariance matrix based on the information of degree of divergence (DOD parameter. The proposed FACKF algorithm shows promising accuracy improvement as compared to the extended Kalman filter (EKF, unscented Kalman filter (UKF, and CKF approaches.

Autonomous terrain characterization and modelling for dynamic control of unmanned vehicles

Science.gov (United States)

Talukder, A.; Manduchi, R.; Castano, R.; Owens, K.; Matthies, L.; Castano, A.; Hogg, R.

2002-01-01

This end-to-end obstacle negotiation system is envisioned to be useful in optimized path planning and vehicle navigation in terrain conditions cluttered with vegetation, bushes, rocks, etc. Results on natural terrain with various natural materials are presented.

On approximate reasoning and minimal models for the development of robust outdoor vehicle navigation schemes

International Nuclear Information System (INIS)

Pin, F.G.

1993-01-01

Outdoor sensor-based operation of autonomous robots has revealed to be an extremely challenging problem, mainly because of the difficulties encountered when attempting to represent the many uncertainties which are always present in the real world. These uncertainties are primarily due to sensor imprecisions and unpredictability of the environment, i.e., lack of full knowledge of the environment characteristics and dynamics. Two basic principles, or philosophies, and their associated methodologies are proposed in an attempt to remedy some of these difficulties. The first principle is based on the concept of ''minimal model'' for accomplishing given tasks and proposes to utilize only the minimum level of information and precision necessary to accomplish elemental functions of complex tasks. This approach diverges completely from the direction taken by most artificial vision studies which conventionally call for crisp and detailed analysis of every available component in the perception data. The paper will first review the basic concepts of this approach and will discuss its pragmatic feasibility when embodied in a behaviorist framework. The second principle which is proposed deals with implicit representation of uncertainties using Fuzzy Set Theory-based approximations and approximate reasoning, rather than explicit (crisp) representation through calculation and conventional propagation techniques. A framework which merges these principles and approaches is presented, and its application to the problem of sensor-based outdoor navigation of a mobile robot is discussed. Results of navigation experiments with a real car in actual outdoor environments are also discussed to illustrate the feasibility of the overall concept

On approximate reasoning and minimal models for the development of robust outdoor vehicle navigation schemes

Energy Technology Data Exchange (ETDEWEB)

Pin, F.G.

1993-11-01

Outdoor sensor-based operation of autonomous robots has revealed to be an extremely challenging problem, mainly because of the difficulties encountered when attempting to represent the many uncertainties which are always present in the real world. These uncertainties are primarily due to sensor imprecisions and unpredictability of the environment, i.e., lack of full knowledge of the environment characteristics and dynamics. Two basic principles, or philosophies, and their associated methodologies are proposed in an attempt to remedy some of these difficulties. The first principle is based on the concept of ``minimal model`` for accomplishing given tasks and proposes to utilize only the minimum level of information and precision necessary to accomplish elemental functions of complex tasks. This approach diverges completely from the direction taken by most artificial vision studies which conventionally call for crisp and detailed analysis of every available component in the perception data. The paper will first review the basic concepts of this approach and will discuss its pragmatic feasibility when embodied in a behaviorist framework. The second principle which is proposed deals with implicit representation of uncertainties using Fuzzy Set Theory-based approximations and approximate reasoning, rather than explicit (crisp) representation through calculation and conventional propagation techniques. A framework which merges these principles and approaches is presented, and its application to the problem of sensor-based outdoor navigation of a mobile robot is discussed. Results of navigation experiments with a real car in actual outdoor environments are also discussed to illustrate the feasibility of the overall concept.

A Short Tutorial on Inertial Navigation System and Global Positioning System Integration

Science.gov (United States)

Smalling, Kyle M.; Eure, Kenneth W.

2015-01-01

The purpose of this document is to describe a simple method of integrating Inertial Navigation System (INS) information with Global Positioning System (GPS) information for an improved estimate of vehicle attitude and position. A simple two dimensional (2D) case is considered. The attitude estimates are derived from sensor data and used in the estimation of vehicle position and velocity through dead reckoning within the INS. The INS estimates are updated with GPS estimates using a Kalman filter. This tutorial is intended for the novice user with a focus on bringing the reader from raw sensor measurements to an integrated position and attitude estimate. An application is given using a remotely controlled ground vehicle operating in assumed 2D environment. The theory is developed first followed by an illustrative example.

A Visual-Aided Inertial Navigation and Mapping System

Directory of Open Access Journals (Sweden)

Rodrigo Munguía

2016-05-01

Full Text Available State estimation is a fundamental necessity for any application involving autonomous robots. This paper describes a visual-aided inertial navigation and mapping system for application to autonomous robots. The system, which relies on Kalman filtering, is designed to fuse the measurements obtained from a monocular camera, an inertial measurement unit (IMU and a position sensor (GPS. The estimated state consists of the full state of the vehicle: the position, orientation, their first derivatives and the parameter errors of the inertial sensors (i.e., the bias of gyroscopes and accelerometers. The system also provides the spatial locations of the visual features observed by the camera. The proposed scheme was designed by considering the limited resources commonly available in small mobile robots, while it is intended to be applied to cluttered environments in order to perform fully vision-based navigation in periods where the position sensor is not available. Moreover, the estimated map of visual features would be suitable for multiple tasks: i terrain analysis; ii three-dimensional (3D scene reconstruction; iii localization, detection or perception of obstacles and generating trajectories to navigate around these obstacles; and iv autonomous exploration. In this work, simulations and experiments with real data are presented in order to validate and demonstrate the performance of the proposal.

Feasibility of Using Synthetic Aperture Radar to Aid UAV Navigation.

Science.gov (United States)

Nitti, Davide O; Bovenga, Fabio; Chiaradia, Maria T; Greco, Mario; Pinelli, Gianpaolo

2015-07-28

This study explores the potential of Synthetic Aperture Radar (SAR) to aid Unmanned Aerial Vehicle (UAV) navigation when Inertial Navigation System (INS) measurements are not accurate enough to eliminate drifts from a planned trajectory. This problem can affect medium-altitude long-endurance (MALE) UAV class, which permits heavy and wide payloads (as required by SAR) and flights for thousands of kilometres accumulating large drifts. The basic idea is to infer position and attitude of an aerial platform by inspecting both amplitude and phase of SAR images acquired onboard. For the amplitude-based approach, the system navigation corrections are obtained by matching the actual coordinates of ground landmarks with those automatically extracted from the SAR image. When the use of SAR amplitude is unfeasible, the phase content can be exploited through SAR interferometry by using a reference Digital Terrain Model (DTM). A feasibility analysis was carried out to derive system requirements by exploring both radiometric and geometric parameters of the acquisition setting. We showed that MALE UAV, specific commercial navigation sensors and SAR systems, typical landmark position accuracy and classes, and available DTMs lead to estimated UAV coordinates with errors bounded within ±12 m, thus making feasible the proposed SAR-based backup system.

Feasibility of Using Synthetic Aperture Radar to Aid UAV Navigation

Directory of Open Access Journals (Sweden)

Davide O. Nitti

2015-07-01

Full Text Available This study explores the potential of Synthetic Aperture Radar (SAR to aid Unmanned Aerial Vehicle (UAV navigation when Inertial Navigation System (INS measurements are not accurate enough to eliminate drifts from a planned trajectory. This problem can affect medium-altitude long-endurance (MALE UAV class, which permits heavy and wide payloads (as required by SAR and flights for thousands of kilometres accumulating large drifts. The basic idea is to infer position and attitude of an aerial platform by inspecting both amplitude and phase of SAR images acquired onboard. For the amplitude-based approach, the system navigation corrections are obtained by matching the actual coordinates of ground landmarks with those automatically extracted from the SAR image. When the use of SAR amplitude is unfeasible, the phase content can be exploited through SAR interferometry by using a reference Digital Terrain Model (DTM. A feasibility analysis was carried out to derive system requirements by exploring both radiometric and geometric parameters of the acquisition setting. We showed that MALE UAV, specific commercial navigation sensors and SAR systems, typical landmark position accuracy and classes, and available DTMs lead to estimated UAV coordinates with errors bounded within ±12 m, thus making feasible the proposed SAR-based backup system.

Evaluation of navigation interfaces in virtual environments

Science.gov (United States)

Mestre, Daniel R.

2014-02-01

When users are immersed in cave-like virtual reality systems, navigational interfaces have to be used when the size of the virtual environment becomes larger than the physical extent of the cave floor. However, using navigation interfaces, physically static users experience self-motion (visually-induced vection). As a consequence, sensorial incoherence between vision (indicating self-motion) and other proprioceptive inputs (indicating immobility) can make them feel dizzy and disoriented. We tested, in two experimental studies, different locomotion interfaces. The objective was twofold: testing spatial learning and cybersickness. In a first experiment, using first-person navigation with a flystick ®, we tested the effect of sensorial aids, a spatialized sound or guiding arrows on the ground, attracting the user toward the goal of the navigation task. Results revealed that sensorial aids tended to impact negatively spatial learning. Moreover, subjects reported significant levels of cybersickness. In a second experiment, we tested whether such negative effects could be due to poorly controlled rotational motion during simulated self-motion. Subjects used a gamepad, in which rotational and translational displacements were independently controlled by two joysticks. Furthermore, we tested first- versus third-person navigation. No significant difference was observed between these two conditions. Overall, cybersickness tended to be lower, as compared to experiment 1, but the difference was not significant. Future research should evaluate further the hypothesis of the role of passively perceived optical flow in cybersickness, but manipulating the virtual environment'sperrot structure. It also seems that video-gaming experience might be involved in the user's sensitivity to cybersickness.

A self-calibration method in single-axis rotational inertial navigation system with rotating mechanism

Science.gov (United States)

Chen, Yuanpei; Wang, Lingcao; Li, Kui

2017-10-01

Rotary inertial navigation modulation mechanism can greatly improve the inertial navigation system (INS) accuracy through the rotation. Based on the single-axis rotational inertial navigation system (RINS), a self-calibration method is put forward. The whole system is applied with the rotation modulation technique so that whole inertial measurement unit (IMU) of system can rotate around the motor shaft without any external input. In the process of modulation, some important errors can be decoupled. Coupled with the initial position information and attitude information of the system as the reference, the velocity errors and attitude errors in the rotation are used as measurement to perform Kalman filtering to estimate part of important errors of the system after which the errors can be compensated into the system. The simulation results show that the method can complete the self-calibration of the single-axis RINS in 15 minutes and estimate gyro drifts of three-axis, the installation error angle of the IMU and the scale factor error of the gyro on z-axis. The calibration accuracy of optic gyro drifts could be about 0.003°/h (1σ) as well as the scale factor error could be about 1 parts per million (1σ). The errors estimate reaches the system requirements which can effectively improve the longtime navigation accuracy of the vehicle or the boat.

Computer Navigation-aided Resection of Sacral Chordomas

Directory of Open Access Journals (Sweden)

Yong-Kun Yang

2016-01-01

Full Text Available Background: Resection of sacral chordomas is challenging. The anatomy is complex, and there are often no bony landmarks to guide the resection. Achieving adequate surgical margins is, therefore, difficult, and the recurrence rate is high. Use of computer navigation may allow optimal preoperative planning and improve precision in tumor resection. The purpose of this study was to evaluate the safety and feasibility of computer navigation-aided resection of sacral chordomas. Methods: Between 2007 and 2013, a total of 26 patients with sacral chordoma underwent computer navigation-aided surgery were included and followed for a minimum of 18 months. There were 21 primary cases and 5 recurrent cases, with a mean age of 55.8 years old (range: 35-84 years old. Tumors were located above the level of the S3 neural foramen in 23 patients and below the level of the S3 neural foramen in 3 patients. Three-dimensional images were reconstructed with a computed tomography-based navigation system combined with the magnetic resonance images using the navigation software. Tumors were resected via a posterior approach assisted by the computer navigation. Mean follow-up was 38.6 months (range: 18-84 months. Results: Mean operative time was 307 min. Mean intraoperative blood loss was 3065 ml. For computer navigation, the mean registration deviation during surgery was 1.7 mm. There were 18 wide resections, 4 marginal resections, and 4 intralesional resections. All patients were alive at the final follow-up, with 2 (7.7% exhibiting tumor recurrence. The other 24 patients were tumor-free. The mean Musculoskeletal Tumor Society Score was 27.3 (range: 19-30. Conclusions: Computer-assisted navigation can be safely applied to the resection of the sacral chordomas, allowing execution of preoperative plans, and achieving good oncological outcomes. Nevertheless, this needs to be accomplished by surgeons with adequate experience and skill.

Data Fusion Modeling for an RT3102 and Dewetron System Application in Hybrid Vehicle Stability Testing

Directory of Open Access Journals (Sweden)

Zhibin Miao

2015-08-01

Full Text Available More and more hybrid electric vehicles are driven since they offer such advantages as energy savings and better active safety performance. Hybrid vehicles have two or more power driving systems and frequently switch working condition, so controlling stability is very important. In this work, a two-stage Kalman algorithm method is used to fuse data in hybrid vehicle stability testing. First, the RT3102 navigation system and Dewetron system are introduced. Second, a modeling of data fusion is proposed based on the Kalman filter. Then, this modeling is simulated and tested on a sample vehicle, using Carsim and Simulink software to test the results. The results showed the merits of this modeling.

ROBERT autonomous navigation robot with artificial vision

International Nuclear Information System (INIS)

Cipollini, A.; Meo, G.B.; Nanni, V.; Rossi, L.; Taraglio, S.; Ferjancic, C.

1993-01-01

This work, a joint research between ENEA (the Italian National Agency for Energy, New Technologies and the Environment) and DIGlTAL, presents the layout of the ROBERT project, ROBot with Environmental Recognizing Tools, under development in ENEA laboratories. This project aims at the development of an autonomous mobile vehicle able to navigate in a known indoor environment through the use of artificial vision. The general architecture of the robot is shown together with the data and control flow among the various subsystems. Also the inner structure of the latter complete with the functionalities are given in detail

Automated Announcements of Approaching Emergency Vehicles

Science.gov (United States)

Bachelder, Aaron; Foster, Conrad

2006-01-01

Street intersections that are equipped with traffic lights would also be equipped with means for generating audible announcements of approaching emergency vehicles, according to a proposal. The means to generate the announcements would be implemented in the intersection- based subsystems of emergency traffic-light-preemption systems like those described in the two immediately preceding articles and in "Systems Would Preempt Traffic Lights for Emergency Vehicles" (NPO-30573), NASA Tech Briefs, Vol. 28, No. 10 (October 2004), page 36. Preempting traffic lights is not, by itself, sufficient to warn pedestrians at affected intersections that emergency vehicles are approaching. Automated visual displays that warn of approaching emergency vehicles can be helpful as a supplement to preemption of traffic lights, but experience teaches that for a variety of reasons, pedestrians often do not see such displays. Moreover, in noisy and crowded urban settings, the lights and sirens on emergency vehicles are often not noticed until a few seconds before the vehicles arrive. According to the proposal, the traffic-light preemption subsystem at each intersection would generate an audible announcement for example, emergency vehicle approaching, please clear intersection whenever a preemption was triggered. The subsystem would estimate the time of arrival of an approaching emergency vehicle by use of vehicle identity, position, and time data from one or more sources that could include units connected to traffic loops and/or transponders connected to diagnostic and navigation systems in participating emergency vehicles. The intersection-based subsystem would then start the announcement far enough in advance to enable pedestrians to leave the roadway before any emergency vehicles arrive.

PROPOSED GUIDELINES ON DEVELOPING THE OPTIMISATION MODEL FOR PASSAGE PLANNING IN INLAND WATERWAYS NAVIGATION

OpenAIRE

Ivančić, Paško; Kasum, Joško; Pavić, Ivica

2013-01-01

Road transport networks are overloaded by the increasing number of vehicles [1]. This has resulted in the redirection and the increasing intensity of navigation on rivers, canals and lakes. Transportation by inland waterways of the European Union (EU) represents a reliable, economical and environmentally friendly mode of transport. The latter has been recognized as a key form of transport in the European intermodal transport system. Inland waterways as part of the transport system play an imp...

Unmanned Ground Vehicle Perception Using Thermal Infrared Cameras

Science.gov (United States)

Rankin, Arturo; Huertas, Andres; Matthies, Larry; Bajracharya, Max; Assad, Christopher; Brennan, Shane; Bellut, Paolo; Sherwin, Gary

2011-01-01

TIR cameras can be used for day/night Unmanned Ground Vehicle (UGV) autonomous navigation when stealth is required. The quality of uncooled TIR cameras has significantly improved over the last decade, making them a viable option at low speed Limiting factors for stereo ranging with uncooled LWIR cameras are image blur and low texture scenes TIR perception capabilities JPL has explored includes: (1) single and dual band TIR terrain classification (2) obstacle detection (pedestrian, vehicle, tree trunks, ditches, and water) (3) perception thru obscurants

LATENCY DETERMINATION AND COMPENSATION IN REAL-TIME GNSS/INS INTEGRATED NAVIGATION SYSTEMS

Directory of Open Access Journals (Sweden)

P. D. Solomon

2012-09-01

Full Text Available Unmanned Aerial Vehicle (UAV technology is now commonplace in many defence and civilian environments. However, the high cost of owning and operating a sophisticated UAV has slowed their adoption in many commercial markets. Universities and research groups are actively experimenting with UAVs to further develop the technology, particularly for automated flying operations. The two main UAV platforms used are fixed-wing and helicopter. Helicopter-based UAVs offer many attractive features over fixed-wing UAVs, including vertical take-off, the ability to loiter, and highly dynamic flight. However the control and navigation of helicopters are significantly more demanding than those of fixed-wing UAVs and as such require a high bandwidth real-time Position, Velocity, Attitude (PVA navigation system. In practical Real-Time Navigation Systems (RTNS there are delays in the processing of the GNSS data prior to the fusion of the GNSS data with the INS measurements. This latency must be compensated for otherwise it degrades the solution of the navigation filter. This paper investigates the effect of latency in the arrival time of the GNSS data in a RTNS. Several test drives and flights were conducted with a low-cost RTNS, and compared with a high quality GNSS/INS solution. A technique for the real-time, automated and accurate estimation of the GNSS latency in low-cost systems was developed and tested. The latency estimates were then verified through cross-correlation with the time-stamped measurements from the reference system. A delayed measurement Extended Kalman Filter was then used to allow for the real-time fusing of the delayed measurements, and then a final system developed for on-the-fly measurement and compensation of GNSS latency in a RTNS.

Latency Determination and Compensation in Real-Time Gnss/ins Integrated Navigation Systems

Science.gov (United States)

Solomon, P. D.; Wang, J.; Rizos, C.

2011-09-01

Unmanned Aerial Vehicle (UAV) technology is now commonplace in many defence and civilian environments. However, the high cost of owning and operating a sophisticated UAV has slowed their adoption in many commercial markets. Universities and research groups are actively experimenting with UAVs to further develop the technology, particularly for automated flying operations. The two main UAV platforms used are fixed-wing and helicopter. Helicopter-based UAVs offer many attractive features over fixed-wing UAVs, including vertical take-off, the ability to loiter, and highly dynamic flight. However the control and navigation of helicopters are significantly more demanding than those of fixed-wing UAVs and as such require a high bandwidth real-time Position, Velocity, Attitude (PVA) navigation system. In practical Real-Time Navigation Systems (RTNS) there are delays in the processing of the GNSS data prior to the fusion of the GNSS data with the INS measurements. This latency must be compensated for otherwise it degrades the solution of the navigation filter. This paper investigates the effect of latency in the arrival time of the GNSS data in a RTNS. Several test drives and flights were conducted with a low-cost RTNS, and compared with a high quality GNSS/INS solution. A technique for the real-time, automated and accurate estimation of the GNSS latency in low-cost systems was developed and tested. The latency estimates were then verified through cross-correlation with the time-stamped measurements from the reference system. A delayed measurement Extended Kalman Filter was then used to allow for the real-time fusing of the delayed measurements, and then a final system developed for on-the-fly measurement and compensation of GNSS latency in a RTNS.

Intelligent Autonomy for Unmanned Surface and Underwater Vehicles

Science.gov (United States)

Huntsberger, Terry; Woodward, Gail

2011-01-01

As the Autonomous Underwater Vehicle (AUV) and Autonomous Surface Vehicle (ASV) platforms mature in endurance and reliability, a natural evolution will occur towards longer, more remote autonomous missions. This evolution will require the development of key capabilities that allow these robotic systems to perform a high level of on-board decisionmaking, which would otherwise be performed by humanoperators. With more decision making capabilities, less a priori knowledge of the area of operations would be required, as these systems would be able to sense and adapt to changing environmental conditions, such as unknown topography, currents, obstructions, bays, harbors, islands, and river channels. Existing vehicle sensors would be dual-use; that is they would be utilized for the primary mission, which may be mapping or hydrographic reconnaissance; as well as for autonomous hazard avoidance, route planning, and bathymetric-based navigation. This paper describes a tightly integrated instantiation of an autonomous agent called CARACaS (Control Architecture for Robotic Agent Command and Sensing) developed at JPL (Jet Propulsion Laboratory) that was designed to address many of the issues for survivable ASV/AUV control and to provide adaptive mission capabilities. The results of some on-water tests with US Navy technology test platforms are also presented.

Development and Flight Test of a Robust Optical-Inertial Navigation System Using Low-Cost Sensors

Science.gov (United States)

2008-03-01

for this test. Though, marketed as a GPS/INS, it was in fact used simply as an IMU for this test. The raw inertial measurement data (from the...Performance Evaluation of Low Cost MEMS-Based IMU Integrated With GPS for Land Vehicle Navigation Application. MS Thesis, UCGE Reports Number

Accelerating navigation in the VecGeom geometry modeller

Science.gov (United States)

Wenzel, Sandro; Zhang, Yang; pre="for the"> VecGeom Developers,

2017-10-01

The VecGeom geometry library is a relatively recent effort aiming to provide a modern and high performance geometry service for particle detector simulation in hierarchical detector geometries common to HEP experiments. One of its principal targets is the efficient use of vector SIMD hardware instructions to accelerate geometry calculations for single track as well as multi-track queries. Previously, excellent performance improvements compared to Geant4/ROOT could be reported for elementary geometry algorithms at the level of single shape queries. In this contribution, we will focus on the higher level navigation algorithms in VecGeom, which are the most important components as seen from the simulation engines. We will first report on our R&D effort and developments to implement SIMD enhanced data structures to speed up the well-known “voxelised” navigation algorithms, ubiquitously used for particle tracing in complex detector modules consisting of many daughter parts. Second, we will discuss complementary new approaches to improve navigation algorithms in HEP. These ideas are based on a systematic exploitation of static properties of the detector layout as well as automatic code generation and specialisation of the C++ navigator classes. Such specialisations reduce the overhead of generic- or virtual function based algorithms and enhance the effectiveness of the SIMD vector units. These novel approaches go well beyond the existing solutions available in Geant4 or TGeo/ROOT, achieve a significantly superior performance, and might be of interest for a wide range of simulation backends (GeantV, Geant4). We exemplify this with concrete benchmarks for the CMS and ALICE detectors.

Continuous monitoring the vehicle dynamics and driver behavior using navigation systems

Science.gov (United States)

Ene, George

2017-10-01

In all fields cost is very important and the increasing amount of data that are needed for active safety systems, like ADAS, lead to implementation of some complex and powerful unit for processing raw data. In this manner is necessary a cost-effective method to estimate the maximum available tire road friction during acceleration and braking by continuous monitoring the vehicle dynamics and driver behavior. The method is based on the hypothesis that short acceleration and braking periods can indicate vehicle dynamics, and thus the available tire road friction coefficient, and also human behavior and his limits. Support for this hypothesis is found in the literature and is supported by the result of experiments conducted under different conditions and seasons.

A Lane-Level LBS System for Vehicle Network with High-Precision BDS/GPS Positioning

Science.gov (United States)

Guo, Chi; Guo, Wenfei; Cao, Guangyi; Dong, Hongbo

2015-01-01

In recent years, research on vehicle network location service has begun to focus on its intelligence and precision. The accuracy of space-time information has become a core factor for vehicle network systems in a mobile environment. However, difficulties persist in vehicle satellite positioning since deficiencies in the provision of high-quality space-time references greatly limit the development and application of vehicle networks. In this paper, we propose a high-precision-based vehicle network location service to solve this problem. The major components of this study include the following: (1) application of wide-area precise positioning technology to the vehicle network system. An adaptive correction message broadcast protocol is designed to satisfy the requirements for large-scale target precise positioning in the mobile Internet environment; (2) development of a concurrence service system with a flexible virtual expansion architecture to guarantee reliable data interaction between vehicles and the background; (3) verification of the positioning precision and service quality in the urban environment. Based on this high-precision positioning service platform, a lane-level location service is designed to solve a typical traffic safety problem. PMID:25755665

Autonomous vehicles:challenges, opportunities, and future implications for transportation policies

Institute of Scientific and Technical Information of China (English)

Saeed Asadi Bagloee; Madjid Tavana; Mohsen Asadi; Tracey Oliver

2016-01-01

This study investigates the challenges and opportunities pertaining to transportation policies that may arise as a result of emerging autonomous vehicle (AV) technologies. AV technologies can decrease the trans-portation cost and increase accessibility to low-income households and persons with mobility issues. This emerg-ing technology also has far-reaching applications and implications beyond all current expectations. This paper provides a comprehensive review of the relevant literature and explores a broad spectrum of issues from safety to machine ethics. An indispensable part of a prospective AV development is communication over cars and infrastructure (connected vehicles). A major knowledge gap exists in AV technology with respect to routing behaviors. Connected-vehicle technology provides a great opportunity to imple-ment an efficient and intelligent routing system. To this end, we propose a conceptual navigation model based on a fleet of AVs that are centrally dispatched over a network seeking system optimization. This study contributes to the literature on two fronts: (i) it attempts to shed light on future opportunities as well as possible hurdles associated with AV technology;and (ii) it conceptualizes a navigation model for the AV which leads to highly efficient traffic circulations.

Improving Canada's Marine Navigation System through e-Navigation

Directory of Open Access Journals (Sweden)

Daniel Breton

2016-06-01

The conclusion proposed is that on-going work with key partners and stakeholders can be used as the primary mechanism to identify e-Navigation related innovation and needs, and to prioritize next steps. Moving forward in Canada, implementation of new e-navigation services will continue to be stakeholder driven, and used to drive improvements to Canada's marine navigation system.

Trajectory generation for an on-road autonomous vehicle

Science.gov (United States)

Horst, John; Barbera, Anthony

2006-05-01

We describe an algorithm that generates a smooth trajectory (position, velocity, and acceleration at uniformly sampled instants of time) for a car-like vehicle autonomously navigating within the constraints of lanes in a road. The technique models both vehicle paths and lane segments as straight line segments and circular arcs for mathematical simplicity and elegance, which we contrast with cubic spline approaches. We develop the path in an idealized space, warp the path into real space and compute path length, generate a one-dimensional trajectory along the path length that achieves target speeds and positions, and finally, warp, translate, and rotate the one-dimensional trajectory points onto the path in real space. The algorithm moves a vehicle in lane safely and efficiently within speed and acceleration maximums. The algorithm functions in the context of other autonomous driving functions within a carefully designed vehicle control hierarchy.

TP-Space RRT – Kinematic Path Planning of Non-Holonomic Any-Shape Vehicles

Directory of Open Access Journals (Sweden)

Jose Luis Blanco

2015-05-01

Full Text Available The autonomous navigation of vehicles typically combines two kinds of methods: a path is first planned, and then the robot is driven by a local obstacle-avoidance controller. The present work, which focuses on path planning, proposes an extension to the well-known rapidly-exploring random tree (RRT algorithm to allow its integration with a trajectory parameter-space (TP-space as an efficient method to detect collision-free, kinematically-feasible paths for arbitrarily-shaped vehicles. In contrast to original RRT, this proposal generates navigation trees, with poses as nodes, whose edges are all kinematically-feasible paths, suitable to being accurately followed by vehicles driven by pure reactive algorithms. Initial experiments demonstrate the suitability of the method with an Ackermann-steering vehicle model whose severe kinematic constraints cannot be obviated. An important result that sets this work apart from previous research is the finding that employing several families of potential trajectories to expand the tree, which can be done efficiently under the TP-space formalism, improves the optimality of the planned trajectories. A reference C++ implementation has been released as open-source.

Multi-level Bayesian analyses for single- and multi-vehicle freeway crashes.

Science.gov (United States)

Yu, Rongjie; Abdel-Aty, Mohamed

2013-09-01

This study presents multi-level analyses for single- and multi-vehicle crashes on a mountainous freeway. Data from a 15-mile mountainous freeway section on I-70 were investigated. Both aggregate and disaggregate models for the two crash conditions were developed. Five years of crash data were used in the aggregate investigation, while the disaggregate models utilized one year of crash data along with real-time traffic and weather data. For the aggregate analyses, safety performance functions were developed for the purpose of revealing the contributing factors for each crash type. Two methodologies, a Bayesian bivariate Poisson-lognormal model and a Bayesian hierarchical Poisson model with correlated random effects, were estimated to simultaneously analyze the two crash conditions with consideration of possible correlations. Except for the factors related to geometric characteristics, two exposure parameters (annual average daily traffic and segment length) were included. Two different sets of significant explanatory and exposure variables were identified for the single-vehicle (SV) and multi-vehicle (MV) crashes. It was found that the Bayesian bivariate Poisson-lognormal model is superior to the Bayesian hierarchical Poisson model, the former with a substantially lower DIC and more significant variables. In addition to the aggregate analyses, microscopic real-time crash risk evaluation models were developed for the two crash conditions. Multi-level Bayesian logistic regression models were estimated with the random parameters accounting for seasonal variations, crash-unit-level diversity and segment-level random effects capturing unobserved heterogeneity caused by the geometric characteristics. The model results indicate that the effects of the selected variables on crash occurrence vary across seasons and crash units; and that geometric characteristic variables contribute to the segment variations: the more unobserved heterogeneity have been accounted, the better

Control of Multiple Robotic Sentry Vehicles

Energy Technology Data Exchange (ETDEWEB)

Feddema, J.; Klarer, P.; Lewis, C.

1999-04-01

As part of a project for the Defense Advanced Research Projects Agency, Sandia National Laboratories is developing and testing the feasibility of using of a cooperative team of robotic sentry vehicles to guard a perimeter and to perform surround and diversion tasks. This paper describes on-going activities in the development of these robotic sentry vehicles. To date, we have developed a robotic perimeter detection system which consists of eight ''Roving All Terrain Lunar Explorer Rover'' (RATLER{trademark}) vehicles, a laptop-based base-station, and several Miniature Intrusion Detection Sensors (MIDS). A radio frequency receiver on each of the RATLER vehicles alerts the sentry vehicles of alarms from the hidden MIDS. When an alarm is received, each vehicle decides whether it should investigate the alarm based on the proximity of itself and the other vehicles to the alarm. As one vehicle attends an alarm, the other vehicles adjust their position around the perimeter to better prepare for another alarm. We have also demonstrated the ability to drive multiple vehicles in formation via tele-operation or by waypoint GPS navigation. This is currently being extended to include mission planning capabilities. At the base-station, the operator can draw on an aerial map the goal regions to be surrounded and the repulsive regions to be avoided. A potential field path planner automatically generates a path from the vehicles' current position to the goal regions while avoiding the repulsive regions and the other vehicles. This path is previewed to the operator before the regions are downloaded to the vehicles. The same potential field path planner resides on the vehicle, except additional repulsive forces from on-board proximity sensors guide the vehicle away from unplanned obstacles.

Navigation skill impairment: Another dimension of the driving difficulties in minimal hepatic encephalopathy.

Science.gov (United States)

Bajaj, Jasmohan S; Hafeezullah, Muhammad; Hoffmann, Raymond G; Varma, Rajiv R; Franco, Jose; Binion, David G; Hammeke, Thomas A; Saeian, Kia

2008-02-01

Patients with minimal hepatic encephalopathy (MHE) have attention, response inhibition, and working memory difficulties that are associated with driving impairment and high motor vehicle accident risk. Navigation is a complex system needed for safe driving that requires functioning working memory and other domains adversely affected by MHE. The aim of this study was to determine the effect of MHE on navigation skills and correlate them with psychometric impairment. Forty-nine nonalcoholic patients with cirrhosis (34 MHE+, 15 MHE-; divided on the basis of a battery of block design, digit symbol, and number connection test A) and 48 age/education-matched controls were included. All patients underwent the psychometric battery and inhibitory control test (ICT) (a test of response inhibition) and driving simulation. Driving simulation consisted of 4 parts: (1) training; (2) driving (outcome being accidents); (3) divided attention (outcome being missed tasks); and (4) navigation, driving along a marked path on a map in a "virtual city" (outcome being illegal turns). Illegal turns were significantly higher in MHE+ (median 1; P = 0.007) compared with MHE-/controls (median 0). Patients who were MHE+ missed more divided attention tasks compared with others (median MHE+ 1, MHE-/controls 0; P = 0.001). Similarly, accidents were higher in patients who were MHE+ (median 2.5; P = 0.004) compared with MHE- (median 1) or controls (median 2). Accidents and illegal turns were significantly correlated (P = 0.001, r = 0.51). ICT impairment was the test most correlated with illegal turns (r = 0.6) and accidents (r = 0.44), although impairment on the other tests were also correlated with illegal turns. Patients positive for MHE have impaired navigation skills on a driving simulator, which is correlated with impairment in response inhibition (ICT) and attention. This navigation difficulty may pose additional driving problems, compounding the pre-existing deleterious effect of attention

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

Science.gov (United States)

2013-09-01

Width Modulation QuarC Quanser Real-time Control RC Remote Controlled RPV Remotely Piloted Vehicles SLAM Simultaneous Localization and Mapping UAV...development of the following systems: 1. Navigation (GPS, Lidar , etc.) 2. Communication (Datalink) 3. Ground Control Station (GUI, software programming

Pembangunan Sistem Penentuan Posisi dan Navigasi Berbasiskan Sistem Unmanned Surface Vehicle (USV) untuk Survei Batimetri

OpenAIRE

Ratih C, Ni Made Rai; Suwardhi, Deni

2014-01-01

Unmanned Surface Vehicle (USV) refers to any vehicle that operates on the surface of the water without a crew. Nowadays, not only for military purpose, many of civilian purposes was also taken in considerations Operating the ordinary hydrographic vessel need the wider horizontal and vertical space. USV is more capable for charting the very shallow and narrow waters. This research is intended to build the positioning and navigation system based on Unmanned Surface Vehicle System as the startin...

Theoretical Limits of Lunar Vision Aided Navigation with Inertial Navigation System

Science.gov (United States)

2015-03-26

THEORETICAL LIMITS OF LUNAR VISION AIDED NAVIGATION WITH INERTIAL NAVIGATION SYSTEM THESIS David W. Jones, Capt, USAF AFIT-ENG-MS-15-M-020 DEPARTMENT...Government and is not subject to copyright protection in the United States. AFIT-ENG-MS-15-M-020 THEORETICAL LIMITS OF LUNAR VISION AIDED NAVIGATION WITH...DISTRIBUTION UNLIMITED. AFIT-ENG-MS-15-M-020 THEORETICAL LIMITS OF LUNAR VISION AIDED NAVIGATION WITH INERTIAL NAVIGATION SYSTEM THESIS David W. Jones

Bioinspired polarization navigation sensor for autonomous munitions systems

Science.gov (United States)

Giakos, G. C.; Quang, T.; Farrahi, T.; Deshpande, A.; Narayan, C.; Shrestha, S.; Li, Y.; Agarwal, M.

2013-05-01

Small unmanned aerial vehicles UAVs (SUAVs), micro air vehicles (MAVs), Automated Target Recognition (ATR), and munitions guidance, require extreme operational agility and robustness which can be partially offset by efficient bioinspired imaging sensor designs capable to provide enhanced guidance, navigation and control capabilities (GNC). Bioinspired-based imaging technology can be proved useful either for long-distance surveillance of targets in a cluttered environment, or at close distances limited by space surroundings and obstructions. The purpose of this study is to explore the phenomenology of image formation by different insect eye architectures, which would directly benefit the areas of defense and security, on the following four distinct areas: a) fabrication of the bioinspired sensor b) optical architecture, c) topology, and d) artificial intelligence. The outcome of this study indicates that bioinspired imaging can impact the areas of defense and security significantly by dedicated designs fitting into different combat scenarios and applications.

Battery control system for hybrid vehicle and method for controlling a hybrid vehicle battery

Science.gov (United States)

Bockelmann, Thomas R [Battle Creek, MI; Beaty, Kevin D [Kalamazoo, MI; Zou, Zhanijang [Battle Creek, MI; Kang, Xiaosong [Battle Creek, MI

2009-07-21

A battery control system for controlling a state of charge of a hybrid vehicle battery includes a detecting arrangement for determining a vehicle operating state or an intended vehicle operating state and a controller for setting a target state of charge level of the battery based on the vehicle operating state or the intended vehicle operating state. The controller is operable to set a target state of charge level at a first level during a mobile vehicle operating state and at a second level during a stationary vehicle operating state or in anticipation of the vehicle operating in the stationary vehicle operating state. The invention further includes a method for controlling a state of charge of a hybrid vehicle battery.

A nonlinear model predictive control formulation for obstacle avoidance in high-speed autonomous ground vehicles in unstructured environments

Science.gov (United States)

Liu, Jiechao; Jayakumar, Paramsothy; Stein, Jeffrey L.; Ersal, Tulga

2018-06-01

This paper presents a nonlinear model predictive control (MPC) formulation for obstacle avoidance in high-speed, large-size autono-mous ground vehicles (AGVs) with high centre of gravity (CoG) that operate in unstructured environments, such as military vehicles. The term 'unstructured' in this context denotes that there are no lanes or traffic rules to follow. Existing MPC formulations for passenger vehicles in structured environments do not readily apply to this context. Thus, a new nonlinear MPC formulation is developed to navigate an AGV from its initial position to a target position at high-speed safely. First, a new cost function formulation is used that aims to find the shortest path to the target position, since no reference trajectory exists in unstructured environments. Second, a region partitioning approach is used in conjunction with a multi-phase optimal control formulation to accommodate the complicated forms the obstacle-free region can assume due to the presence of multiple obstacles in the prediction horizon in an unstructured environment. Third, the no-wheel-lift-off condition, which is the major dynamical safety concern for high-speed, high-CoG AGVs, is ensured by limiting the steering angle within a range obtained offline using a 14 degrees-of-freedom vehicle dynamics model. Thus, a safe, high-speed navigation is enabled in an unstructured environment. Simulations of an AGV approaching multiple obstacles are provided to demonstrate the effectiveness of the algorithm.

Equivalent noise level response to number of vehicles: a comparison between a high traffic flow and low traffic flow highway in Klang Valley, Malaysia

OpenAIRE

Halim, Herni; Abdullah, Ramdzani

2014-01-01

HIGHLIGHTS Highway traffic noise is a serious problem in Malaysia Heavy traffic flow highway recorded higher noise level compared to low traffic flow Noise level stabilized at certain number of vehicles on the road i.e above 500 vehicles. Although much research on road traffic noise has found that noise level increase are influenced by driver behavior and source-receiver distance, little attention has been paid to the relationship between noise level and total number of vehicles...

Navigational efficiency in a biased and correlated random walk model of individual animal movement.

Science.gov (United States)

Bailey, Joseph D; Wallis, Jamie; Codling, Edward A

2018-01-01

Understanding how an individual animal is able to navigate through its environment is a key question in movement ecology that can give insight into observed movement patterns and the mechanisms behind them. Efficiency of navigation is important for behavioral processes at a range of different spatio-temporal scales, including foraging and migration. Random walk models provide a standard framework for modeling individual animal movement and navigation. Here we consider a vector-weighted biased and correlated random walk (BCRW) model for directed movement (taxis), where external navigation cues are balanced with forward persistence. We derive a mathematical approximation of the expected navigational efficiency for any BCRW of this form and confirm the model predictions using simulations. We demonstrate how the navigational efficiency is related to the weighting given to forward persistence and external navigation cues, and highlight the counter-intuitive result that for low (but realistic) levels of error on forward persistence, a higher navigational efficiency is achieved by giving more weighting to this indirect navigation cue rather than direct navigational cues. We discuss and interpret the relevance of these results for understanding animal movement and navigation strategies. © 2017 by the Ecological Society of America.

Using a sand wave model for optimal monitoring of navigation depth

NARCIS (Netherlands)

Knaapen, Michiel; Hulscher, Suzanne J.M.H.; Tiessen, Meinard C.H.; van den Berg, J.; Parker, G.; García, M.H.

2005-01-01

In the Euro Channel to Rotterdam Harbor, sand waves reduce the navigable depth to an unacceptable level. To avoid the risk of grounding, the navigation depth is monitored and sand waves that reduce the navigation depth unacceptably are dredged. After the dredging, the sand waves slowly regain their

A Novel Online Data-Driven Algorithm for Detecting UAV Navigation Sensor Faults.

Science.gov (United States)

Sun, Rui; Cheng, Qi; Wang, Guanyu; Ochieng, Washington Yotto

2017-09-29

The use of Unmanned Aerial Vehicles (UAVs) has increased significantly in recent years. On-board integrated navigation sensors are a key component of UAVs' flight control systems and are essential for flight safety. In order to ensure flight safety, timely and effective navigation sensor fault detection capability is required. In this paper, a novel data-driven Adaptive Neuron Fuzzy Inference System (ANFIS)-based approach is presented for the detection of on-board navigation sensor faults in UAVs. Contrary to the classic UAV sensor fault detection algorithms, based on predefined or modelled faults, the proposed algorithm combines an online data training mechanism with the ANFIS-based decision system. The main advantages of this algorithm are that it allows real-time model-free residual analysis from Kalman Filter (KF) estimates and the ANFIS to build a reliable fault detection system. In addition, it allows fast and accurate detection of faults, which makes it suitable for real-time applications. Experimental results have demonstrated the effectiveness of the proposed fault detection method in terms of accuracy and misdetection rate.

A Novel Online Data-Driven Algorithm for Detecting UAV Navigation Sensor Faults

Directory of Open Access Journals (Sweden)

Rui Sun

2017-09-01

Full Text Available The use of Unmanned Aerial Vehicles (UAVs has increased significantly in recent years. On-board integrated navigation sensors are a key component of UAVs’ flight control systems and are essential for flight safety. In order to ensure flight safety, timely and effective navigation sensor fault detection capability is required. In this paper, a novel data-driven Adaptive Neuron Fuzzy Inference System (ANFIS-based approach is presented for the detection of on-board navigation sensor faults in UAVs. Contrary to the classic UAV sensor fault detection algorithms, based on predefined or modelled faults, the proposed algorithm combines an online data training mechanism with the ANFIS-based decision system. The main advantages of this algorithm are that it allows real-time model-free residual analysis from Kalman Filter (KF estimates and the ANFIS to build a reliable fault detection system. In addition, it allows fast and accurate detection of faults, which makes it suitable for real-time applications. Experimental results have demonstrated the effectiveness of the proposed fault detection method in terms of accuracy and misdetection rate.

Efficient Multivariable Generalized Predictive Control for Autonomous Underwater Vehicle in Vertical Plane

OpenAIRE

Yao, Xuliang; Yang, Guangyi

2016-01-01

This paper presents the design and simulation validation of a multivariable GPC (generalized predictive control) for AUV (autonomous underwater vehicle) in vertical plane. This control approach has been designed in the case of AUV navigating with low speed near water surface, in order to restrain wave disturbance effectively and improve pitch and heave motion stability. The proposed controller guarantees compliance with rudder manipulation, AUV output constraints, and driving energy consumpti...

Infrared stereo calibration for unmanned ground vehicle navigation

Science.gov (United States)

Harguess, Josh; Strange, Shawn

2014-06-01

The problem of calibrating two color cameras as a stereo pair has been heavily researched and many off-the-shelf software packages, such as Robot Operating System and OpenCV, include calibration routines that work in most cases. However, the problem of calibrating two infrared (IR) cameras for the purposes of sensor fusion and point could generation is relatively new and many challenges exist. We present a comparison of color camera and IR camera stereo calibration using data from an unmanned ground vehicle. There are two main challenges in IR stereo calibration; the calibration board (material, design, etc.) and the accuracy of calibration pattern detection. We present our analysis of these challenges along with our IR stereo calibration methodology. Finally, we present our results both visually and analytically with computed reprojection errors.

Error Analysis of Inertial Navigation Systems Using Test Algorithms

OpenAIRE

Vaispacher, Tomáš; Bréda, Róbert; Adamčík, František

2015-01-01

Content of this contribution is an issue of inertial sensors errors, specification of inertial measurement units and generating of test signals for Inertial Navigation System (INS). Given the different levels of navigation tasks, part of this contribution is comparison of the actual types of Inertial Measurement Units. Considering this comparison, there is proposed the way of solving inertial sensors errors and their modelling for low – cost inertial navigation applications. The last part is ...

Sex differences in navigation strategy and efficiency.

Science.gov (United States)

Boone, Alexander P; Gong, Xinyi; Hegarty, Mary

2018-05-22

Research on human navigation has indicated that males and females differ in self-reported navigation strategy as well as objective measures of navigation efficiency. In two experiments, we investigated sex differences in navigation strategy and efficiency using an objective measure of strategy, the dual-solution paradigm (DSP; Marchette, Bakker, & Shelton, 2011). Although navigation by shortcuts and learned routes were the primary strategies used in both experiments, as in previous research on the DSP, individuals also utilized route reversals and sometimes found the goal location as a result of wandering. Importantly, sex differences were found in measures of both route selection and navigation efficiency. In particular, males were more likely to take shortcuts and reached their goal location faster than females, while females were more likely to follow learned routes and wander. Self-report measures of strategy were only weakly correlated with objective measures of strategy, casting doubt on their usefulness. This research indicates that the sex difference in navigation efficiency is large, and only partially related to an individual's navigation strategy as measured by the dual-solution paradigm.

An Improved Strong Tracking Cubature Kalman Filter for GPS/INS Integrated Navigation Systems.

Science.gov (United States)

Feng, Kaiqiang; Li, Jie; Zhang, Xi; Zhang, Xiaoming; Shen, Chong; Cao, Huiliang; Yang, Yanyu; Liu, Jun

2018-06-12

The cubature Kalman filter (CKF) is widely used in the application of GPS/INS integrated navigation systems. However, its performance may decline in accuracy and even diverge in the presence of process uncertainties. To solve the problem, a new algorithm named improved strong tracking seventh-degree spherical simplex-radial cubature Kalman filter (IST-7thSSRCKF) is proposed in this paper. In the proposed algorithm, the effect of process uncertainty is mitigated by using the improved strong tracking Kalman filter technique, in which the hypothesis testing method is adopted to identify the process uncertainty and the prior state estimate covariance in the CKF is further modified online according to the change in vehicle dynamics. In addition, a new seventh-degree spherical simplex-radial rule is employed to further improve the estimation accuracy of the strong tracking cubature Kalman filter. In this way, the proposed comprehensive algorithm integrates the advantage of 7thSSRCKF’s high accuracy and strong tracking filter’s strong robustness against process uncertainties. The GPS/INS integrated navigation problem with significant dynamic model errors is utilized to validate the performance of proposed IST-7thSSRCKF. Results demonstrate that the improved strong tracking cubature Kalman filter can achieve higher accuracy than the existing CKF and ST-CKF, and is more robust for the GPS/INS integrated navigation system.

Navigating on handheld displays: Dynamic versus Static Keyhole Navigation

NARCIS (Netherlands)

Mehra, S.; Werkhoven, P.; Worring, M.

2006-01-01

Handheld displays leave little space for the visualization and navigation of spatial layouts representing rich information spaces. The most common navigation method for handheld displays is static peephole navigation: The peephole is static and we move the spatial layout behind it (scrolling). A

Model-based software engineering for an optical navigation system for spacecraft

Science.gov (United States)

Franz, T.; Lüdtke, D.; Maibaum, O.; Gerndt, A.

2018-06-01

The project Autonomous Terrain-based Optical Navigation (ATON) at the German Aerospace Center (DLR) is developing an optical navigation system for future landing missions on celestial bodies such as the moon or asteroids. Image data obtained by optical sensors can be used for autonomous determination of the spacecraft's position and attitude. Camera-in-the-loop experiments in the Testbed for Robotic Optical Navigation (TRON) laboratory and flight campaigns with unmanned aerial vehicle (UAV) are performed to gather flight data for further development and to test the system in a closed-loop scenario. The software modules are executed in the C++ Tasking Framework that provides the means to concurrently run the modules in separated tasks, send messages between tasks, and schedule task execution based on events. Since the project is developed in collaboration with several institutes in different domains at DLR, clearly defined and well-documented interfaces are necessary. Preventing misconceptions caused by differences between various development philosophies and standards turned out to be challenging. After the first development cycles with manual Interface Control Documents (ICD) and manual implementation of the complex interactions between modules, we switched to a model-based approach. The ATON model covers a graphical description of the modules, their parameters and communication patterns. Type and consistency checks on this formal level help to reduce errors in the system. The model enables the generation of interfaces and unified data types as well as their documentation. Furthermore, the C++ code for the exchange of data between the modules and the scheduling of the software tasks is created automatically. With this approach, changing the data flow in the system or adding additional components (e.g., a second camera) have become trivial.

Model-based software engineering for an optical navigation system for spacecraft

Science.gov (United States)

Franz, T.; Lüdtke, D.; Maibaum, O.; Gerndt, A.

2017-09-01

The project Autonomous Terrain-based Optical Navigation (ATON) at the German Aerospace Center (DLR) is developing an optical navigation system for future landing missions on celestial bodies such as the moon or asteroids. Image data obtained by optical sensors can be used for autonomous determination of the spacecraft's position and attitude. Camera-in-the-loop experiments in the Testbed for Robotic Optical Navigation (TRON) laboratory and flight campaigns with unmanned aerial vehicle (UAV) are performed to gather flight data for further development and to test the system in a closed-loop scenario. The software modules are executed in the C++ Tasking Framework that provides the means to concurrently run the modules in separated tasks, send messages between tasks, and schedule task execution based on events. Since the project is developed in collaboration with several institutes in different domains at DLR, clearly defined and well-documented interfaces are necessary. Preventing misconceptions caused by differences between various development philosophies and standards turned out to be challenging. After the first development cycles with manual Interface Control Documents (ICD) and manual implementation of the complex interactions between modules, we switched to a model-based approach. The ATON model covers a graphical description of the modules, their parameters and communication patterns. Type and consistency checks on this formal level help to reduce errors in the system. The model enables the generation of interfaces and unified data types as well as their documentation. Furthermore, the C++ code for the exchange of data between the modules and the scheduling of the software tasks is created automatically. With this approach, changing the data flow in the system or adding additional components (e.g., a second camera) have become trivial.

Deformation measurements at the vehicle tunnel overpass using a hydrostatic level system

International Nuclear Information System (INIS)

Friedsam, H.; Penicka, J.; Error, J.

1996-04-01

Long-term storage ring and experiment hall floor settlements are being monitored on a regular bases in six-month intervals utilizing common geometric leveling techniques. One area of concern requiring special attention in terms of settlements is the vehicle tunnel that undercuts the experiment hall an storage ring at the south side of the APS. Five user beamlines crossing over the vehicle tunnel could be affected by deformations in this area. Assuming the most severe temperature fluctuations would occur during the winter time, a monitoring system was installed at the beginning of 1996. The length of the experiment was dictated by the installation schedule of the user enclosures at the overpass

Celestial Navigation in the USA, Fiji, and Tunisia

Science.gov (United States)

Holbrook, Jarita C.

2015-05-01

Today there are many coastal communities that are home to navigators who use stars for position finding at night; I was, however, unaware of this fact when I began researching celestial navigation practices in 1997. My project focused on three communities: the Moce Islanders of Fiji, the Kerkennah Islanders in Tunisia, and the U.S. Navy officers and students at the United States Naval Academy, Annapolis, Maryland. My goal was to answer the question of why people continue to navigate by the stars, but also to understand the role of technology in their navigation practices. Using anthropology techniques of ethnography including participant observation, formal and informal interviews, audio and videotaping, I gathered data over five years at the three communities. I began by learning the details of how they use the stars for navigation. Next, I learned about who did the navigation and where they learned to navigate. I gathered opinions on various navigation aids and instruments, and opinions about the future of using the stars for navigation. I listened to the stories that they told about navigating. In the United States I worked in English, in Fiji, in Fijian and English, and in Tunisia, French and English. For the formal interviews I worked with translators. The navigators use stars for navigating today but the future of their techniques is not certain. Though practiced today, these celestial navigation traditions have undergone and continue to undergo changes. New navigational technologies are part of the stimulation for change, thus 'a meeting of different worlds' is symbolized by peoples encounters with these technologies.

Interfacing Space Communications and Navigation Network Simulation with Distributed System Integration Laboratories (DSIL)

Science.gov (United States)

Jennings, Esther H.; Nguyen, Sam P.; Wang, Shin-Ywan; Woo, Simon S.

2008-01-01

NASA's planned Lunar missions will involve multiple NASA centers where each participating center has a specific role and specialization. In this vision, the Constellation program (CxP)'s Distributed System Integration Laboratories (DSIL) architecture consist of multiple System Integration Labs (SILs), with simulators, emulators, testlabs and control centers interacting with each other over a broadband network to perform test and verification for mission scenarios. To support the end-to-end simulation and emulation effort of NASA' exploration initiatives, different NASA centers are interconnected to participate in distributed simulations. Currently, DSIL has interconnections among the following NASA centers: Johnson Space Center (JSC), Kennedy Space Center (KSC), Marshall Space Flight Center (MSFC) and Jet Propulsion Laboratory (JPL). Through interconnections and interactions among different NASA centers, critical resources and data can be shared, while independent simulations can be performed simultaneously at different NASA locations, to effectively utilize the simulation and emulation capabilities at each center. Furthermore, the development of DSIL can maximally leverage the existing project simulation and testing plans. In this work, we describe the specific role and development activities at JPL for Space Communications and Navigation Network (SCaN) simulator using the Multi-mission Advanced Communications Hybrid Environment for Test and Evaluation (MACHETE) tool to simulate communications effects among mission assets. Using MACHETE, different space network configurations among spacecrafts and ground systems of various parameter sets can be simulated. Data that is necessary for tracking, navigation, and guidance of spacecrafts such as Crew Exploration Vehicle (CEV), Crew Launch Vehicle (CLV), and Lunar Relay Satellite (LRS) and orbit calculation data are disseminated to different NASA centers and updated periodically using the High Level Architecture (HLA). In

Navigating oceans and cultures: Polynesian and European navigation systems in the late eighteenth century

Science.gov (United States)

Walker, M.

2012-05-01

Significant differences in the rotation of the celestial dome between the tropical and temperate zones did not stop the peoples of either the tropical Pacific or temperate Europe from using geocentric astronomy to guide exploration of the oceans. Although the differences in the night sky contributed to differences between the Pacific Island and European systems for navigation at sea, the two navigation systems exhibit substantial similarities. Both systems define positions on the surface of the Earth using two coordinates that vary at right angles to each other and use stars, and to a lesser extent the sun, to determine directions. This essay explores similarities and differences in the use of geocentric astronomy for navigation at sea by the peoples of Polynesia and Europe in the late eighteenth century. Captain Cook's orders to discover the unknown southern continent after observing the transit of Venus combined with differences in language and culture to obscure the deeper similarities between the navigation systems used by Cook and the Polynesians. Although it was a further 200 years before anthropologists studied Pacific navigation, collaborations in voyaging with communities in Oceania demonstrated the effectiveness of Pacific navigation systems, revived interest in traditional voyaging in island communities around the Pacific, and potentially open the way for further collaborations in other areas.

Navigation system for a mobile robot with a visual sensor using a fish-eye lens

Science.gov (United States)

Kurata, Junichi; Grattan, Kenneth T. V.; Uchiyama, Hironobu

1998-02-01

Various position sensing and navigation systems have been proposed for the autonomous control of mobile robots. Some of these systems have been installed with an omnidirectional visual sensor system that proved very useful in obtaining information on the environment around the mobile robot for position reckoning. In this article, this type of navigation system is discussed. The sensor is composed of one TV camera with a fish-eye lens, using a reference target on a ceiling and hybrid image processing circuits. The position of the robot, with respect to the floor, is calculated by integrating the information obtained from a visual sensor and a gyroscope mounted in the mobile robot, and the use of a simple algorithm based on PTP control for guidance is discussed. An experimental trial showed that the proposed system was both valid and useful for the navigation of an indoor vehicle.

Map matching and heuristic elimination of gyro drift for personal navigation systems in GPS-denied conditions

International Nuclear Information System (INIS)

Aggarwal, Priyanka; Thomas, David; Ojeda, Lauro; Borenstein, Johann

2011-01-01

This paper introduces a method for the substantial reduction of heading errors in inertial navigation systems used under GPS-denied conditions. Presumably, the method is applicable for both vehicle-based and personal navigation systems, but experiments were performed only with a personal navigation system called 'personal dead reckoning' (PDR). In order to work under GPS-denied conditions, the PDR system uses a foot-mounted inertial measurement unit (IMU). However, gyro drift in this IMU can cause large heading errors after just a few minutes of walking. To reduce these errors, the map-matched heuristic drift elimination (MAPHDE) method was developed, which estimates gyro drift errors by comparing IMU-derived heading to the direction of the nearest street segment in a database of street maps. A heuristic component in this method provides tolerance to short deviations from walking along the street, such as when crossing streets or intersections. MAPHDE keeps heading errors almost at zero, and, as a result, position errors are dramatically reduced. In this paper, MAPHDE was used in a variety of outdoor walks, without any use of GPS. This paper explains the MAPHDE method in detail and presents experimental results

RFID-based vehicle positioning and its applications in connected vehicles.

Science.gov (United States)

Wang, Jianqiang; Ni, Daiheng; Li, Keqiang

2014-03-04

This paper proposed an RFID-based vehicle positioning approach to facilitate connected vehicles applications. When a vehicle passes over an RFID tag, the vehicle position is given by the accurate position stored in the tag. At locations without RFID coverage, the vehicle position is estimated from the most recent tag location using a kinematics integration algorithm till updates from the next tag. The accuracy of RFID positioning is verified empirically in two independent ways with one using radar and the other a photoelectric switch. The former is designed to verify whether the dynamic position obtained from RFID tags matches the position measured by radar that is regarded as accurate. The latter aims to verify whether the position estimated from the kinematics integration matches the position obtained from RFID tags. Both means supports the accuracy of RFID-based positioning. As a supplement to GPS which suffers from issues such as inaccuracy and loss of signal, RFID positioning is promising in facilitating connected vehicles applications. Two conceptual applications are provided here with one in vehicle operational control and the other in Level IV intersection control.

Power electronics and electric machinery challenges and opportunities in electric and hybrid vehicles

Energy Technology Data Exchange (ETDEWEB)

Adams, D.J.; Hsu, J.S.; Young, R.W. [Oak Ridge National Lab., TN (United States); Peng, F.Z. [Univ. of Tennessee, Knoxville, TN (United States)

1997-06-01

The development of power electronics and electric machinery presents significant challenges to the advancement of electric and hybrid vehicles. Electronic components and systems development for vehicle applications have progressed from the replacement of mechanical systems to the availability of features that can only be realized through interacting electronic controls and devices. Near-term applications of power electronics in vehicles will enable integrated powertrain controls, integrated chassis system controls, and navigation and communications systems. Future applications of optimized electric machinery will enable highly efficient and lightweight systems. This paper will explore the areas where research and development is required to ensure the continued development of power electronics and electric machines to meet the rigorous demands of automotive applications. Additionally, recent advances in automotive related power electronics and electric machinery at Oak Ridge National Laboratory will be explained. 3 refs., 5 figs.

Cooperative Path-Planning for Multi-Vehicle Systems

Directory of Open Access Journals (Sweden)

Qichen Wang

2014-11-01

Full Text Available In this paper, we propose a collision avoidance algorithm for multi-vehicle systems, which is a common problem in many areas, including navigation and robotics. In dynamic environments, vehicles may become involved in potential collisions with each other, particularly when the vehicle density is high and the direction of travel is unrestricted. Cooperatively planning vehicle movement can effectively reduce and fairly distribute the detour inconvenience before subsequently returning vehicles to their intended paths. We present a novel method of cooperative path planning for multi-vehicle systems based on reinforcement learning to address this problem as a decision process. A dynamic system is described as a multi-dimensional space formed by vectors as states to represent all participating vehicles’ position and orientation, whilst considering the kinematic constraints of the vehicles. Actions are defined for the system to transit from one state to another. In order to select appropriate actions whilst satisfying the constraints of path smoothness, constant speed and complying with a minimum distance between vehicles, an approximate value function is iteratively developed to indicate the desirability of every state-action pair from the continuous state space and action space. The proposed scheme comprises two phases. The convergence of the value function takes place in the former learning phase, and it is then used as a path planning guideline in the subsequent action phase. This paper summarizes the concept and methodologies used to implement this online cooperative collision avoidance algorithm and presents results and analysis regarding how this cooperative scheme improves upon two baseline schemes where vehicles make movement decisions independently.

Enhancing Allocentric Spatial Recall in Pre-schoolers through Navigational Training Programme

Directory of Open Access Journals (Sweden)

Maddalena Boccia

2017-10-01

Full Text Available Unlike for other abilities, children do not receive systematic spatial orientation training at school, even though navigational training during adulthood improves spatial skills. We investigated whether navigational training programme (NTP improved spatial orientation skills in pre-schoolers. We administered 12-week NTP to seventeen 4- to 5-year-old children (training group, TG. The TG children and 17 age-matched children (control group, CG who underwent standard didactics were tested twice before (T0 and after (T1 the NTP using tasks that tap into landmark, route and survey representations. We determined that the TG participants significantly improved their performances in the most demanding navigational task, which is the task that taps into survey representation. This improvement was significantly higher than that observed in the CG, suggesting that NTP fostered the acquisition of survey representation. Such representation is typically achieved by age seven. This finding suggests that NTP improves performance on higher-level navigational tasks in pre-schoolers.

An alternative ionospheric correction model for global navigation satellite systems

Science.gov (United States)

Hoque, M. M.; Jakowski, N.

2015-04-01

The ionosphere is recognized as a major error source for single-frequency operations of global navigation satellite systems (GNSS). To enhance single-frequency operations the global positioning system (GPS) uses an ionospheric correction algorithm (ICA) driven by 8 coefficients broadcasted in the navigation message every 24 h. Similarly, the global navigation satellite system Galileo uses the electron density NeQuick model for ionospheric correction. The Galileo satellite vehicles (SVs) transmit 3 ionospheric correction coefficients as driver parameters of the NeQuick model. In the present work, we propose an alternative ionospheric correction algorithm called Neustrelitz TEC broadcast model NTCM-BC that is also applicable for global satellite navigation systems. Like the GPS ICA or Galileo NeQuick, the NTCM-BC can be optimized on a daily basis by utilizing GNSS data obtained at the previous day at monitor stations. To drive the NTCM-BC, 9 ionospheric correction coefficients need to be uploaded to the SVs for broadcasting in the navigation message. Our investigation using GPS data of about 200 worldwide ground stations shows that the 24-h-ahead prediction performance of the NTCM-BC is better than the GPS ICA and comparable to the Galileo NeQuick model. We have found that the 95 percentiles of the prediction error are about 16.1, 16.1 and 13.4 TECU for the GPS ICA, Galileo NeQuick and NTCM-BC, respectively, during a selected quiet ionospheric period, whereas the corresponding numbers are found about 40.5, 28.2 and 26.5 TECU during a selected geomagnetic perturbed period. However, in terms of complexity the NTCM-BC is easier to handle than the Galileo NeQuick and in this respect comparable to the GPS ICA.

Real-time Risk Assessment for Aids to Navigation Using Fuzzy-FSA on Three-Dimensional Simulation System

OpenAIRE

Jinbiao Chen; Chaojian Shi; Dongxing Jia

2014-01-01

The risk level of the Aids to Navigation (AtoNs) can reflect the ship navigation safety level in the channel to some extent. In order to appreciate the risk level of the aids to navigation (AtoNs) in a navigation channel and to provide some decision-making suggestions for the AtoNs Maintenance and Management Department, the risk assessment index system of the AtoNs was built considering the advanced experience of IALA. Under the Formal Safety Assessment frame, taking the advantages of the fuz...

Performance enhancement of low-cost, high-accuracy, state estimation for vehicle collision prevention system using ANFIS

Science.gov (United States)

Saadeddin, Kamal; Abdel-Hafez, Mamoun F.; Jaradat, Mohammad A.; Jarrah, Mohammad Amin

2013-12-01

In this paper, a low-cost navigation system that fuses the measurements of the inertial navigation system (INS) and the global positioning system (GPS) receiver is developed. First, the system's dynamics are obtained based on a vehicle's kinematic model. Second, the INS and GPS measurements are fused using an extended Kalman filter (EKF) approach. Subsequently, an artificial intelligence based approach for the fusion of INS/GPS measurements is developed based on an Input-Delayed Adaptive Neuro-Fuzzy Inference System (IDANFIS). Experimental tests are conducted to demonstrate the performance of the two sensor fusion approaches. It is found that the use of the proposed IDANFIS approach achieves a reduction in the integration development time and an improvement in the estimation accuracy of the vehicle's position and velocity compared to the EKF based approach.

Launch Vehicle Abort Analysis for Failures Leading to Loss of Control

Science.gov (United States)

Hanson, John M.; Hill, Ashley D.; Beard, Bernard B.

2013-01-01

Launch vehicle ascent is a time of high risk for an onboard crew. There is a large fraction of possible failures for which time is of the essence and a successful abort is possible if the detection and action happens quickly enough. This paper focuses on abort determination based on data already available from the Guidance, Navigation, and Control system. This work is the result of failure analysis efforts performed during the Ares I launch vehicle development program. The two primary areas of focus are the derivation of abort triggers to ensure that abort occurs as quickly as possible when needed, but that false aborts are avoided, and evaluation of success in aborting off the failing launch vehicle.

Concept of navigation and automatic steering of the measuring dolphin

Energy Technology Data Exchange (ETDEWEB)

Majohr, J.; Buch, T.; Korte, C. [Rostock Univ. (Germany). Inst. fuer Automatisierungstechnik

2000-07-01

The Catamaran - Measuring Dolphin (MESSIN) is an unmanned and independently operated craft having been designed for carrying out multiple measuring tasks in the field of marine research and water monitoring especially in shallow waters. An introduction to the navigation, steering and safety systems is given. Furthermore the main components of the track control system and the electronic chart system used here are shown. Results of manoeuvring tests of the MESSIN are represented. This paper gives a contribution to the field of research ''autonomous and full automated vehicle''. (orig.)

Modeling speed and width parameters of vehicle tires for prediction of the reduction in vehicle noise pollution

Directory of Open Access Journals (Sweden)

Amir Esmael Forouhid

2016-06-01

Full Text Available Introduction: Safe driving requires the ability of the driver to receive the messages and complying with them. The most significant consequences of noise pollution are on the human auditory system. Disorders in the auditory system can have harmful side effects for human health. By reducing this kind of pollution in large cities, the quality of life, which is one of the biggest goals of the governments, can be considerably increased. Hence, in the present research, some parameters of vehicle tires were examined as a source of noise pollution, and the results can be taken into consideration in noise pollution reduction. Material and Method: Several vehicles with different tire width were selected for measuring sound level. The sound levels were measured for moving vehicles with the use of the Statistical Pass By Method (SPB, ISO 11819-1. Following sound level measurements for moving vehicles and by considering tire width, mathematical model of noise level was predicted on the basis of the obtained information and by usage of SPSS program and considering vehicle tire parameters. Result: The result of this study showed that the vehicle speed and tire width can affect different sound levels emitted by moving tire on road surface. The average speed of vehicles can play an important role in the noise pollution. By increasing speed, rotation of the the tires on the asphalt is increased, as it is a known factors for noise pollution. Moreover, changing the speed of vehicles is accompanied with abnormal sounds of vehicle engine. According to regression model analysis, the obtained value of R2 for the model is 0.8367 which represents the coefficient of determination. Conclusion: The results suggest the main role of the vehicle speed and tire width in increasing the noise reaches to the drivers and consequent noise pollution, which demonstrates the necessity for noise control measures. According to the obtained model, it is understood that changes in noise

Project Freebird: An orbital transfer vehicle

Science.gov (United States)

Aneses, Carlos A.; Blanchette, Ryan L.; Brann, David M.; Campos, Mario J.; Cohen, Lisa E.; Corcoran, Daniel J., III; Cox, James F.; Curtis, Trevor J.; Douglass, Deborah A.; Downard, Catherine L.

1994-08-01

Freebird is a space-based orbital transfer vehicle designed to repair and deorbit orbital assets. Freebird is based at International Space Station Alpha (ISSA) at an inclination of 51.6 deg and is capable of three types of missions: crewed and teleoperated LEO missions, and extended robotic missions. In a crewed local configuration, the vehicle can visit inclinations between 30.8 deg and 72.4 deg at altitudes close to 390 km. Adding extra fuel tanks extends this range of inclination up to 84.9 deg and down to 18.3 deg. Furthermore, removing the crew module, using the vehicle in a teleoperated manner, and operating with extra fuel tanks allows missions to polar and geosynchronous orbits. To allow for mission flexibility, the vehicle was designed in a semimodular configuration. The major system components include a crew module, a 'smart box' (which contains command, communications, guidance, and navigation equipment), a propulsion pack, extra fuel tanks, and a vehicle storage facility (VSF) for storage purposes. To minimize risk as well as development time and cost, the vehicle was designed using only proven technology or technology which is expected to be flight-qualified in time for the intended launch date of 2002. And, because Freebird carries crew and operates near the space station, it must meet or exceed the NASA reliability standard of 0.994, as well as other standard requirements for such vehicles. The Freebird program was conceived and designed as a way to provide important and currently unavailable satellite repair and replacement services of a value equal to or exceeding operational costs.

RFID-Based Vehicle Positioning and Its Applications in Connected Vehicles

Science.gov (United States)

Wang, Jianqiang; Ni, Daiheng; Li, Keqiang

2014-01-01

This paper proposed an RFID-based vehicle positioning approach to facilitate connected vehicles applications. When a vehicle passes over an RFID tag, the vehicle position is given by the accurate position stored in the tag. At locations without RFID coverage, the vehicle position is estimated from the most recent tag location using a kinematics integration algorithm till updates from the next tag. The accuracy of RFID positioning is verified empirically in two independent ways with one using radar and the other a photoelectric switch. The former is designed to verify whether the dynamic position obtained from RFID tags matches the position measured by radar that is regarded as accurate. The latter aims to verify whether the position estimated from the kinematics integration matches the position obtained from RFID tags. Both means supports the accuracy of RFID-based positioning. As a supplement to GPS which suffers from issues such as inaccuracy and loss of signal, RFID positioning is promising in facilitating connected vehicles applications. Two conceptual applications are provided here with one in vehicle operational control and the other in Level IV intersection control. PMID:24599188

RFID-Based Vehicle Positioning and Its Applications in Connected Vehicles

Directory of Open Access Journals (Sweden)

Jianqiang Wang

2014-03-01

Full Text Available This paper proposed an RFID-based vehicle positioning approach to facilitate connected vehicles applications. When a vehicle passes over an RFID tag, the vehicle position is given by the accurate position stored in the tag. At locations without RFID coverage, the vehicle position is estimated from the most recent tag location using a kinematics integration algorithm till updates from the next tag. The accuracy of RFID positioning is verified empirically in two independent ways with one using radar and the other a photoelectric switch. The former is designed to verify whether the dynamic position obtained from RFID tags matches the position measured by radar that is regarded as accurate. The latter aims to verify whether the position estimated from the kinematics integration matches the position obtained from RFID tags. Both means supports the accuracy of RFID-based positioning. As a supplement to GPS which suffers from issues such as inaccuracy and loss of signal, RFID positioning is promising in facilitating connected vehicles applications. Two conceptual applications are provided here with one in vehicle operational control and the other in Level IV intersection control.

Use and Protection of GPS Sidelobe Signals for Enhanced Navigation Performance in High Earth Orbit

Science.gov (United States)

Parker, Joel J. K.; Valdez, Jennifer E.; Bauer, Frank H.; Moreau, Michael C.

2016-01-01

GPS (Global Positioning System) Space Service Volume (SSV) signal environment is from 3,000-36,000 kilometers altitude. Current SSV specifications only capture performance provided by signals transmitted within 23.5(L1) or 26(L2-L5) off-nadir angle. Recent on-orbit data lessons learned show significant PNT (Positioning, Navigation and Timing) performance improvements when the full aggregate signal is used. Numerous military civil operational missions in High Geosynchronous Earth Orbit (HEOGEO) utilize the full signal to enhance vehicle PNT performance

Reconfigurable On-Board Vision Processing for Small Autonomous Vehicles

Directory of Open Access Journals (Sweden)

James K. Archibald

2006-12-01

Full Text Available This paper addresses the challenge of supporting real-time vision processing on-board small autonomous vehicles. Local vision gives increased autonomous capability, but it requires substantial computing power that is difficult to provide given the severe constraints of small size and battery-powered operation. We describe a custom FPGA-based circuit board designed to support research in the development of algorithms for image-directed navigation and control. We show that the FPGA approach supports real-time vision algorithms by describing the implementation of an algorithm to construct a three-dimensional (3D map of the environment surrounding a small mobile robot. We show that FPGAs are well suited for systems that must be flexible and deliver high levels of performance, especially in embedded settings where space and power are significant concerns.

Reconfigurable On-Board Vision Processing for Small Autonomous Vehicles

Directory of Open Access Journals (Sweden)

Fife WadeS

2007-01-01

Full Text Available This paper addresses the challenge of supporting real-time vision processing on-board small autonomous vehicles. Local vision gives increased autonomous capability, but it requires substantial computing power that is difficult to provide given the severe constraints of small size and battery-powered operation. We describe a custom FPGA-based circuit board designed to support research in the development of algorithms for image-directed navigation and control. We show that the FPGA approach supports real-time vision algorithms by describing the implementation of an algorithm to construct a three-dimensional (3D map of the environment surrounding a small mobile robot. We show that FPGAs are well suited for systems that must be flexible and deliver high levels of performance, especially in embedded settings where space and power are significant concerns.