WorldWideScience

Sample records for autonomous underwater vehicles

  1. Autonomous Underwater Vehicle control

    OpenAIRE

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

    2005-01-01

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

  2. Design of Autonomous Underwater Vehicle

    OpenAIRE

    Tadahiro Hyakudome

    2011-01-01

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

  3. Design of Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Tadahiro Hyakudome

    2011-03-01

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

  4. Insurance for autonomous underwater vehicles

    OpenAIRE

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

    2007-01-01

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

  5. Control of the MARES Autonomous Underwater Vehicle

    OpenAIRE

    Bruno Ferreira; Miguel Pinto; Anibal Matos; Nuno Cruz

    2009-01-01

    This paper focuses the control problem of a nonholonomic autonomous underwater vehicle, moving in the tridimensional space. The dynamic of a body in submarine environments is strongly nonlinear. This implies that classical linear controllers are often inadequate whereby Lyapunov theory is here considered. Methods based in this theory are promising tools to design controllers and are applied to the case of MARES, a small-sized autonomous underwater vehicle. Several controllers based only on Ly...

  6. Modelling tunnel thrusters for autonomous underwater vehicles

    OpenAIRE

    Palmer, A.; Hearn, G.E.; Stevenson, P

    2008-01-01

    With 900 Autonomous Underwater Vehicles (AUVs) required over the next decade (Newman et al., 2007) existing survey-style AUVs need improved utilization factors. Additional control devices to extend operational capability need consideration together with the interchange between AUV control approaches. This paper considers supplementary through-body tunnel thruster control during the transition from survey operation to low-speed manoeuvring. Modified manoeuvring equations permit investigation o...

  7. Autonomous Underwater Vehicle „ABYSS“

    OpenAIRE

    Linke, Peter; Lackschewitz, Klas

    2016-01-01

    The Autonomous Underwater Vehicle (AUV) „ABYSS“ is a modular AUV designed to survey the ocean combining geophysical studies of the seafloor with oceanographic investigations of the overlying water column. The basic mission of ABYSS is deep-sea exploration, specifically in volcanically and tectonically active parts, such as mid-ocean ridges. With a maximum mission depth of 6000 meters, the AUV uses several technologies to map the seafloor accurately and determine its geological ...

  8. Autonomous Underwater Vehicle „ABYSS“

    OpenAIRE

    Linke, Peter; Lackschewitz, Klas

    2016-01-01

    The Autonomous Underwater Vehicle (AUV) „ABYSS“ is a modular AUV designed to survey the ocean combining geophysical studies of the seafloor with oceanographic investigations of the overlying water column. The basic mission of ABYSS is deep-sea exploration, specifically in volcanically and tectonically active parts, such as mid-ocean ridges. With a maximum mission depth of 6000 meters, the AUV uses several technologies to map the seafloor accurately and determine its geological structure with ...

  9. Navigation of autonomous underwater vehicle using extended kalman filter

    Digital Repository Service at National Institute of Oceanography (India)

    Ranjan, T.N.; Nherakkol, A.; Navelkar, G.S.

    To navigate the Autonomous Underwater Vehicle (AUV) accurately is one of the most important aspects in its application. A truly autonomous vehicle must determine its position which requires the optimal integration of all available attitude...

  10. Development of a control system for an autonomous underwater vehicle

    OpenAIRE

    Masmitjà Rusiñol, Ivan; Masmitja Rusinyol, Gerard; González Agudelo, Julián; Shariat Panahi, Shahram; Gomáriz Castro, Spartacus

    2010-01-01

    This work proposes the development of a control system for an autonomous underwater vehicle dedicated to the observation of the oceans. The vehicle, a hybrid between Autonomous Underwater Vehicles (AUVs) and Autonomous Surface Vehicles (ASV), moves on the surface of the sea and makes vertical immersions to obtain profiles of a water column, according to a pre-established plan. The displacement of the vehicle on the surface allows the navigation through GPS and telemetr...

  11. Fault Diagnosis of Autonomous Underwater Vehicles

    Directory of Open Access Journals (Sweden)

    Xiao Liang

    2013-04-01

    Full Text Available In this study, we propose the least disturbance algorithm adding scale factor and shift factor. The dynamic learning ratio can be calculated to minimize the scale factor and shift factor of wavelet function and the variation of net weights and the algorithm improve the stability and the convergence of wavelet neural network. It was applied to build the dynamical model of autonomous underwater vehicles and the residuals are generated by comparing the outputs of the dynamical model with the real state values in the condition of thruster fault. Fault detection rules are distilled by residual analysis to execute thruster fault diagnosis. The results of simulation prove the effectiveness.

  12. Integrated Simulation for Rapid Development of Autonomous Underwater Vehicles

    OpenAIRE

    Brutzman, Donald P.; Kanayama, Yutaka; Zyda, Michael J.

    1992-01-01

    The article of record may be found at http://dx.doi.org/10.1109/AUV.1992.225199 Autonomous Underwater Vehicle Technology, 1992. AUV '92., Proceedings of the 1992 Symposium on The autonomous underwater vehicle (AUV) integrated simulator has been designed to support complete scientific visualization of AUV vehicle performance. High-resolution 3D graphics workstations can provide real-time representations of vehicle dynamics, control system behavior, mission execution, sonar processing and...

  13. Dynamic formation control for autonomous underwater vehicles

    Institute of Scientific and Technical Information of China (English)

    燕雪峰; 古锋; 宋琛; 胡晓琳; 潘毅

    2014-01-01

    Path planning and formation structure forming are two of the most important problems for autonomous underwater vehicles (AUVs) to collaborate with each other. In this work, a dynamic formation model was proposed, in which several algorithms were developed for the complex underwater environment. Dimension changeable particle swarm algorithm was used to find an optimized path by dynamically adjusting the number and the distribution of the path nodes. Position relationship based obstacle avoidance algorithm was designed to detour along the edges of obstacles. Virtual potential point based formation-keeping algorithm was employed by incorporating dynamic strategies which were decided by the current states of the formation. The virtual potential point was used to keep the formation structure when the AUV or the formation was deviated. Simulation results show that an optimal path can be dynamically planned with fewer path nodes and smaller fitness, even with a concave obstacle. It has been also proven that different formation-keeping strategies can be adaptively selected and the formation can change its structure in a narrow area and restore back after passing the obstacle.

  14. Coordinated operation of autonomous underwater and surface vehicles

    OpenAIRE

    Anibal Matos; Nuno Cruz

    2007-01-01

    This work addresses the coordinated operation of an autonomous underwater vehicle and an autonomous surface vessel and its main goal is the development of an infrastructure that allows the surface vessel to dynamically position itself above the underwater vehicle while the later one is collecting data and navigating in long baseline mode using a set of beacons installed in the operation area. Besides a formal statement of the coordination problem, we present results both from real experiments...

  15. A Dynamic Manipulation Strategy for an Intervention Autonomous Underwater Vehicle

    OpenAIRE

    Ridolfi, Alessandro; Conti, Roberto; Costanzi, Riccardo; Fanelli, Francesco; Meli, Enrico

    2015-01-01

    This paper presents the modelling and the control architecture of an Autonomous Underwater Vehicle for Intervention (I-AUV). Autonomous underwater manipulation with free-floating base is still an open topic of research, far from reaching an industrial product. Dynamic manipulation tasks, where relevant vehicle velocities are required during manipulation, over an additional challenge. In this paper, the accurate modelling of an I-AUV is described, not neglecting the interaction wit...

  16. AUTONOMOUS UNDERWATER HYBRID VEHICLE FOR OCEAN SURVEILLANCE

    Directory of Open Access Journals (Sweden)

    KIRUBAKARAN.S,

    2011-05-01

    Full Text Available Coastal areas are among the most vulnerable of all regions to global climate change. Projected impacts from global warming include rising sea levels, intensification of tropical cyclones, larger storm surges, increasing sea-surface temperatures, and – as the oceans absorb more of the carbon dioxide human activities emit to theatmosphere – growing acidification of surface waters. With an estimated 50 per cent of the world’s population now living within 60km of the coast and 60 per cent of cities with population over 5 million located within 100 km of the coast, the Potential impacts of climate change on coastal development and infrastructure is considerable. On-going development has manifested in the form of urban centers, tourist resorts, ports and Industrial areas. The rising sea levels and larger storm surges caused by climate change Threaten to compound such risks. In order to understand the Ocean systems, continuous time series Observation is essential and development of innovative Autonomous Underwater Vehicle (AUV with suite of sensors would be very useful.

  17. Autonomous underwater vehicle control using reinforcement learning policy search methods

    OpenAIRE

    El-Fakdi Sencianes, Andrés; Carreras Pérez, Marc; Palomeras Rovira, Narcís; Ridao Rodríguez, Pere

    2005-01-01

    Autonomous underwater vehicles (AUV) represent a challenging control problem with complex, noisy, dynamics. Nowadays, not only the continuous scientific advances in underwater robotics but the increasing number of subsea missions and its complexity ask for an automatization of submarine processes. This paper proposes a high-level control system for solving the action selection problem of an autonomous robot. The system is characterized by the use of reinforcement learning direct policy search...

  18. Autonomous underwater vehicles modeling, control design and simulation

    CERN Document Server

    Wadoo, Sabiha

    2010-01-01

    Underwater vehicles present some difficult and very particular control system design problems. These are often the result of nonlinear dynamics and uncertain models, as well as the presence of sometimes unforeseeable environmental disturbances that are difficult to measure or estimate. Autonomous Underwater Vehicles: Modeling, Control Design, and Simulation outlines a novel approach to help readers develop models to simulate feedback controllers for motion planning and design. The book combines useful information on both kinematic and dynamic nonlinear feedback control models, providing simula

  19. Navigation of an underwater industrial autonomous vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Korotchentsev, V.I.; Rozenbaum, A.N.; Deshner, A.I. [Rossijskaya Akademiya Nauk, Vladivostok (Russian Federation). Inst. Avtomatiki i Protsessov Upravleniya

    2000-07-01

    This paper suggests a new approach to solving the problem of navigation of an underwater vehicle using arbitrary seafloor relief data. The known methods of building seafloor acoustic maps are not effective for correction of coordinates in areas of smooth relief and in shallow water. The suggested algorithm allows making maps using acoustic sectional view of the seafloor layers. The sectional view is of various forms in different areas of the smooth relief. (orig.)

  20. Coordinated control of networked vehicles: An autonomous underwater system

    OpenAIRE

    Pereira, FL; de Sousa, JB

    2004-01-01

    The specification and design of coordinated control strategies for networked vehicle systems are discussed. The discussion is illustrated with an example of the coordinated operation of two teams of autonomous underwater vehicles collecting data to find the local minimum of a given oceanographic scalar field.

  1. A real time autonomous underwater vehicle Dynamic Simulator

    OpenAIRE

    Jurewicz, Thomas A.

    1990-01-01

    The NPS Autonomous Underwater Vehicle Simulator is a joint project between the Naval Postgraduate School's Mechanical Engineering and Computer Science Departments. In order to test mission planning and execution software, an accurate vehicle dynamic model is required. Using dynamics based upon the Navy's Swimmer Delivery Vehicle (SDV), there is a need to continually update the hydrodynamic coefficients based upon actual vehicle-in-water testing. The NPS AUV Dynamic Simulator contains a full s...

  2. Aquatic flight inspired propulsion for autonomous underwater vehicles

    OpenAIRE

    Man, S.

    2015-01-01

    Modern Autonomous Underwater Vehicle (AUV) technology has a number of limitations and one of these is vehicle manoeuvrability. Conventional flight style AUVs generally have turning circle diameters of five or more vehicle lengths, but most marine animals can turn in under one body length. This shows there is merit in looking at marine animals for inspiration to improve the manoeuvrability of AUVs. Aquatic flight propulsion is one marine animal propulsion strategy that was identified early in ...

  3. Autonomous Underwater Vehicle (AUV) Propulsion System Analysis and Optimization

    OpenAIRE

    Schultz, James Allen

    2009-01-01

    One of the largest design considerations for autonomous underwater vehicles (AUVâ s) that have specific mission scenarios is the propulsive efficiency. The propulsive efficiency affects the amount of power storage required to achieve a specific mission. As the efficiency increases the volume of energy being stored decreases. The decrease in volume allows for a smaller vehicle, which results in a vehicle that requires less thrust to attain a specific speed. The process of selecting an eff...

  4. A highly versatile autonomous underwater vehicle with biomechanical propulsion

    NARCIS (Netherlands)

    Simons, D.G.; Bergers, M.M.C.; Henrion, S.; Hulzenga, J.I.J.; Jutte, R.W.; Pas, W.M.G.; Van Schravendijk, M.; Vercruyssen, T.G.A.; Wilken, A.P.

    2009-01-01

    An autonomous underwater vehicle with a biomechanical propulsion system is a possible answer to the demand for small, silent sensor platforms in many fields. The design of Galatea, a bio-mimetic AUV, involves four aspects: hydrodynamic shape, the propulsion, the motion control systems and payload. T

  5. Navigation of an Autonomous Underwater Vehicle in a Mobile Network

    OpenAIRE

    Nuno Santos; Anibal Matos; Nuno Cruz

    2008-01-01

    This work addresses the implementation of the navigation, guidance and control of autonomous underwater vehicles on mobile acoustic networks. After a theoretical discussion of the algorithms required for such operation, we present results from simulation and real experiments that validate the proposed solutions.

  6. Autonomous underwater vehicles group control in the maritime search operations implementation

    OpenAIRE

    Блінцов, Сергій Володимирович; Тхи, Доан Фук

    2013-01-01

    The applied scientific problem of automated control of group motion of autonomous unmanned underwater vehicles during maritime search operations was considered in the paper. General principles of building the systems of automation control of a group of self-propelled autonomous underwater vehicles under the uncertainty of environment characteristics and non-stationarity of underwater vehicles parameters were given. The features of organization of autonomous underwater vehicles group operation...

  7. Simulation platform of navigation system for autonomous underwater vehicle

    Institute of Scientific and Technical Information of China (English)

    QIN Zheng; BIAN Xin-qian

    2006-01-01

    In view of the characteristics of underwater navigation, the simulation platform of navigation system for autonomous underwater vehicle has been developed based on Windows platform. The system architecture, net communication and the information flow are discussed. The methods of software realization and some key techniques of the Vehicle Computer and the Navigation Equipment Computer are introduced in particular. The software design of Terrain Matching Computer is introduced also. The simulation platform is verified and analyzed through simulation. The results show that the architecture of the platform is reasonable and reliable, and the mathematic models and simulation algorithms of sub-systems are also valid and practicable.

  8. An Autonomous Navigation System for Unmanned Underwater Vehicle

    OpenAIRE

    Kim, Seong-Gon; Kim, Yong-Gi

    2009-01-01

    This paper designed a RVC intelligent system model that can be applied to various unmanned vehicles and the underwater vehicle's intelligent autonomous navigation system was designed consisting of a collision avoidance system, a navigation system and a collision risk computation based on a Virtual world system. During the development of the Virtual world system, several points such as the fusion of different techniques, preservation of system consistency, real time system processing etc. were...

  9. The control system of an autonomous underwater vehicle

    OpenAIRE

    Bjørn Jalving; Nils Størkersen

    1995-01-01

    This paper presents the flight control system of an Autonomous Underwater Vehicle (AUV) developed at the Norwegian Defence Research Establishment. A mathematical model of the vehicle is derived and discussed. The system is separated into lightly interacting subsystems and three autopilots are designed for steering, diving and speed control. The design of the separate controllers is based on PID techniques. Results from sea trials show robust performance and stability for the autopilot.

  10. Contour tracking control for the REMUS autonomous underwater vehicle

    OpenAIRE

    Van Reet, Alan R.

    2005-01-01

    In the interest of enhancing the capabilities of autonomous underwater vehicles US Naval Operations, controlling vehicle position to follow depth contours presents exciting potential for navigation. Use of a contour tracking control algorithm in lieu of preprogrammed waypoint navigation offers distinct advantages within new challenges. The difficult nature of this problem lies in the non-trivial connection between the necessary corrective action and the feedback error used in traditional co...

  11. The control system of an autonomous underwater vehicle

    Directory of Open Access Journals (Sweden)

    Bjørn Jalving

    1995-04-01

    Full Text Available This paper presents the flight control system of an Autonomous Underwater Vehicle (AUV developed at the Norwegian Defence Research Establishment. A mathematical model of the vehicle is derived and discussed. The system is separated into lightly interacting subsystems and three autopilots are designed for steering, diving and speed control. The design of the separate controllers is based on PID techniques. Results from sea trials show robust performance and stability for the autopilot.

  12. Unified Trajectory Planning Algorithms for Autonomous Underwater Vehicle Navigation

    OpenAIRE

    Gal, Oren

    2013-01-01

    This paper presents two efficient methods for obstacle avoidance and path planning for Autonomous Underwater Vehicle (AUV). These methods take into account the dynamic constraints of the vehicle using advanced simulator of AUV considering low level control and stability effects. We present modified visibility graph local avoidance method and a spiral algorithm for obstacle avoidance. The algorithms were tested in challenged scenarios demonstrating safe trajectory planning.

  13. Fish telemetry and positioning from an autonomous underwater vehicle (AUV)

    OpenAIRE

    Thomas M. Grothues; Dobarro, Joseph A.

    2010-01-01

    We explored telemetry of transmitter tagged fishes from an autonomous underwater vehicle with a hydrophone/ datalogger processing code-division-multiple- access acoustic signals. Geolocation estimates used synthetic aperture and relative sound strength mapping. Signal reception patterns from tagged Atlantic sturgeon were similar to that of moored reference tags but those from tagged winter flounder were reduced in range due to burying behavior. Peer Reviewed

  14. Acoustic underwater navigation of the Phoenix Autonomous Underwater Vehicle using the DiveTracker system

    OpenAIRE

    Scrivener, Arthur W.

    1996-01-01

    Autonomous Underwater Vehicles (AUVs) require a navigation system in order to conduct useful functions. This research was an experimental investigation of the commercial DiveTracker underwater acoustic navigation system used onboard the NPS Phoenix AUV. Tests conducted with the DiveTracker system proved that the system could be used successfully in AUV navigation while submerged and revealed that more precise positioning could be obtained through postconditioning of the DiveTracker output ran...

  15. Coverage path planning for autonomous underwater vehicles

    OpenAIRE

    Galceran Yebenes, Enric

    2014-01-01

    This thesis proposes new methods to find collision-free paths allowing an AUV to cover an area of the ocean floor with its sensors, which is known as coverage path planning. First, we propose a coverage path planning method to plan 2D, safe-altitude surveys which provides a principled way to account for obstacles in AUV survey planning. Its main advantage is that it minimizes redundant coverage when the vehicle navigates at constant depth, leading to shorter paths. Second, we provide a method...

  16. Control of Open Contour Formations of Autonomous Underwater Vehicles

    OpenAIRE

    Uwe Zimmer; Shahab Kalantar

    2008-01-01

    In this paper, we propose a distributed elastic behaviour for a deformable chain-like formation of small autonomous underwater vehicles with the task of forming special shapes which have been explicitly defined or are defined by some iso-contour of an environmental concentration field. In the latter case, the formation has to move in such a way as to meet certain formation parameters as well as adapt to the iso-line. We base our controller on our previous models (for manually controlled end p...

  17. Control of Open Contour Formations of Autonomous Underwater Vehicles

    Directory of Open Access Journals (Sweden)

    Uwe Zimmer

    2008-11-01

    Full Text Available In this paper, we propose a distributed elastic behaviour for a deformable chain-like formation of small autonomous underwater vehicles with the task of forming special shapes which have been explicitly defined or are defined by some iso-contour of an environmental concentration field. In the latter case, the formation has to move in such a way as to meet certain formation parameters as well as adapt to the iso-line. We base our controller on our previous models (for manually controlled end points using general curve evolution theory but will also propose appropriate motions for the end robots of an open chain.

  18. 3D Track-keeping Method for Autonomous Underwater Vehicle

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; Bian Xin-Qian; Chang Zong-Hu

    2002-01-01

    In this paper, 3D track-keeping control method for autonomous underwater vehicle (AUV) with and without the influence of ocean current is investigated. Because the system to be controlled is highly nonlinear and strong coupled, an approach is used to divide it into two subsystems. One is to control the heading and the track error on the horizontal plane. The other is to control the pitch and the track error on the vertical plane. The results of computer simulation show that the autopilot works properly, it can capture the current waypoint and turns to track the next path automatically.

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

    OpenAIRE

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

    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 irrespec...

  20. SotonAUV: the design and development of a small, manoeuvrable autonomous underwater vehicle

    OpenAIRE

    Akhtman, J.; Furlong, M.; Palmer, A.; Phillips, A.; Sharkh, S.M.; Turnock, S.R.

    2008-01-01

    The University of Southampton's entry into the Student Autonomous Underwater Challenge-Europe (SAUC-E) 2007 was a custom designed and built autonomous underwater vehicle (AUV) named 'SotonAUV'. Originally developed for SAUC-E 2006, the vehicle was significantly upgraded for the 2007 competition. The mechanical design of the vehicle is described, and an overview of the autonomy and control approaches employed is provided. The updated vehicle successfully competed in SAUC-E 2007, winning first ...

  1. Reactor Power for Large Displacement Autonomous Underwater Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    McClure, Patrick Ray [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reid, Robert Stowers [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Poston, David Irvin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dasari, Venkateswara Rao [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-24

    This is a PentaChart on reactor power for large displacement autonomous underwater vehicles. Currently AUVs use batteries or combinations of batteries and fuel cells for power. Battery/fuel cell technology is limited by duration. Batteries and cell fuels are a good match for some missions, but other missions could benefit greatly by a longer duration. The goal is the following: to design nuclear systems to powr an AUV and meet design constraints including non-proliferation issues, power level, size constraints, and power conversion limitations. The action plan is to continue development of a range of systems for terrestrial systems and focus on a system for TItan Moon as alternative to Pu-238 for NASA.

  2. Stability Analysis on Speed Control System of Autonomous Underwater Vehicle

    Institute of Scientific and Technical Information of China (English)

    LI Ye; PANG Yong-jie; WAN Lei; WANG Fang; LIAO Yu-lei

    2009-01-01

    The stability of the motion control system is one of the decisive factors of the control quality for Autonomous Underwater Vehicle (AUV).The divergence of control,which the unstable system may be brought about,is fatal to the operation of AUV.The stability analysis of the PD and S-surface speed controllers based on the Lyapunov' s direct method is proposed in this paper.After decoupling the six degree-of-freedom (DOF) motions of the AUV,the axial dynamic behavior is discussed and the condition is deduced,in which the parameters selection within stability domain can guarantee the system asymptotically stable.The experimental results in a tank and on the sea have successfully verified the algorithm reliability,which can be served as a good reference for analyzing other AUV nonlinear control systems.

  3. Fuzzy Adaptive Control for Trajectory Tracking of Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Saeed Nakhkoob

    2014-01-01

    Full Text Available In this paper, the problem of the position and attitude tracking of an autonomous underwater vehicle (AUV in the horizontal plane, under the presence of ocean current disturbances is discussed. The effect of the gradual variation of the parameters is taken into account. The effectiveness of the adaptive controller is compared with a feedback linearization method and fuzzy gain control approach. The proposed strategy has been tested through simulations. Also, the performance of the propos-ed method is compared with other strategies given in some other studies. The boundedness and asymptotic converge-nce properties of the control algorithm and its semi-global stability are analytically proven using Lyapunov stability theory and Barbalat’s lemma.

  4. Expert S-surface control for autonomous underwater vehicles

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lei; PANG Yong-jie; SU Yu-min; ZHAO Fu-long; QIN Zai-bai

    2008-01-01

    S-surface control has proven to be an effective means for motion control of underwater autonomous vehicles (AUV). However there are still problems maintaining steady precision of course due to the constant need to adjust parameters,especially where there are disturbing currents. Thus an intelligent integral was introduced to improve precision. An expert S-surface control was developed to tune the parameters on-line,based on the expert system,it provides S-surface control according to practical experience and control knowledge. To prevent control output over-compensation,a fuzzy neural network was included to adjust the production rules to the knowledge base. Experiments were conducted on an AUV simulation platform,and the results show that the expert S-surface controller performs better than an S-surface controller in environments with currents,producing good steady precision of course in a robust way.

  5. 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.

  6. Visual Odometry and Mapping for Underwater Autonomous Vehicles

    OpenAIRE

    Botelho, Silvia; Oliveira, Gabriel; Drews, Paulo; Figueiredo, Monica; Haffele, Celina

    2010-01-01

    This work proposed a new approach to visual odometry and mapping of a underwater robot using only online visual information. This system can be used either in autonomous inspection tasks or in control assistance of robot closed-loop, in case of a human remote operator. A set of tests were performed under different underwater conditions. The effectiveness of our proposal was evaluated inside a set of real scenario, with different levels of turbidity, snow marine, non-uniform illumination and n...

  7. Heading Lock Maneuver Testing of Autonomous Underwater Vehicle

    CERN Document Server

    Muljowidodo, K

    2008-01-01

    In recent years, Autonomous Underwater Vehicle (UAV) research and development at Bandung Institute of Technology in Indonesia has achieved the testing stage in the field. This testing was still being classified as the early testing, since some of the preliminary tests were carried out in the scale of the laboratory. The paper would discuss the laboratory test and several tests that were done in the field. Discussions were stressed in the procedure and the aim that will be achieved, along with several early results. The testing was carried out in the lake with the area around 8300 Ha and the maximum depth of 50 meters. The location of the testing was chosen with consideration of minimizing the effect of the current and the wave, as well as the location that was not too far from the Laboratory. The type of testing that will be discussed in paper was Heading Lock Maneuver Testing. The vehicle was tested to move with a certain cruising speed, afterwards it was commanded by an arbitrarily selected heading directio...

  8. Risk analysis for autonomous underwater vehicle operations in extreme environments.

    Science.gov (United States)

    Brito, Mario Paulo; Griffiths, Gwyn; Challenor, Peter

    2010-12-01

    Autonomous underwater vehicles (AUVs) are used increasingly to explore hazardous marine environments. Risk assessment for such complex systems is based on subjective judgment and expert knowledge as much as on hard statistics. Here, we describe the use of a risk management process tailored to AUV operations, the implementation of which requires the elicitation of expert judgment. We conducted a formal judgment elicitation process where eight world experts in AUV design and operation were asked to assign a probability of AUV loss given the emergence of each fault or incident from the vehicle's life history of 63 faults and incidents. After discussing methods of aggregation and analysis, we show how the aggregated risk estimates obtained from the expert judgments were used to create a risk model. To estimate AUV survival with mission distance, we adopted a statistical survival function based on the nonparametric Kaplan-Meier estimator. We present theoretical formulations for the estimator, its variance, and confidence limits. We also present a numerical example where the approach is applied to estimate the probability that the Autosub3 AUV would survive a set of missions under Pine Island Glacier, Antarctica in January-March 2009. PMID:20731790

  9. An autonomous underwater vehicle "Maya", for monitoring coastal waters, estuaries, rivers and dams

    Digital Repository Service at National Institute of Oceanography (India)

    Mascarenhas, A.A.M.Q.; Navelkar, G.S.; Madhan, R.; Dabholkar, N.A.; Prabhudesai, S.P.; Maurya, P.K.; Desa, E.; Afzulpurkar, S.; Suresh, T.; Matondkar, S.G.P.; Mahalunkar, A.

    This article demonstrates the use of Maya, Autonomous Underwater Vehicle (AUV) for monitoring coastal waters, estuaries, rivers and dams. Maya is a mono hull structure with detachable nose and tail cones. The nose cone is mission specific...

  10. An Autonomous Underwater Vehicle Simulation Using Linear Quadratic Servo Based on Open Control Platform

    OpenAIRE

    Nanang Syahroni; Jae Weon Choi

    2012-01-01

    This paper presents an optimal regulator for depth control simulation of an autonomous underwater vehicle (AUV) using a new approach of decentralized system environment called open control platform (OCP). Simulation results are presented to demonstrate performance of the proposed method.

  11. AFSC/ABL: Autonomous underwater vehicle for tracking acoustically-tagged fish 2010

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Autonomous underwater vehicles (AUVs) are increasingly being used to collect physical, chemical, and biological information in the marine environment. Recent...

  12. Coordinated Formation Control of Multiple Autonomous Underwater Vehicles for Pipeline Inspection

    OpenAIRE

    Xianbo Xiang; Bruno Jouvencel; Olivier Parodi

    2010-01-01

    International audience This paper addresses the control problem of inspecting underwater pipeline on the seabed, with coordinated multiple autonomous underwater vehicles in a formation. Based on the leader-follower strategy, the dedicated nonlinear path following controller is rigorously built on Lyapunov-based design, driving a fleet of vehicles onto assigned parallel paths elevated and offset from the underwater pipeline, while keeping a triangle formation to capture complete 3D images f...

  13. Classification of underwater targets from autonomous underwater vehicle sampled bistatic acoustic scattered fields.

    Science.gov (United States)

    Fischell, Erin M; Schmidt, Henrik

    2015-12-01

    One of the long term goals of autonomous underwater vehicle (AUV) minehunting is to have multiple inexpensive AUVs in a harbor autonomously classify hazards. Existing acoustic methods for target classification using AUV-based sensing, such as sidescan and synthetic aperture sonar, require an expensive payload on each outfitted vehicle and post-processing and/or image interpretation. A vehicle payload and machine learning classification methodology using bistatic angle dependence of target scattering amplitudes between a fixed acoustic source and target has been developed for onboard, fully autonomous classification with lower cost-per-vehicle. To achieve the high-quality, densely sampled three-dimensional (3D) bistatic scattering data required by this research, vehicle sampling behaviors and an acoustic payload for precision timed data acquisition with a 16 element nose array were demonstrated. 3D bistatic scattered field data were collected by an AUV around spherical and cylindrical targets insonified by a 7-9 kHz fixed source. The collected data were compared to simulated scattering models. Classification and confidence estimation were shown for the sphere versus cylinder case on the resulting real and simulated bistatic amplitude data. The final models were used for classification of simulated targets in real time in the LAMSS MOOS-IvP simulation package [M. Benjamin, H. Schmidt, P. Newman, and J. Leonard, J. Field Rob. 27, 834-875 (2010)]. PMID:26723332

  14. New approach for a Reconfigurable Autonomous Underwater Vehicle for Intervention

    OpenAIRE

    Novi, G; Melchiorri, Claudio; García Sánchez, Juan Carlos; Sanz Valero, Pedro José; Ridao, Pere; Oliver, Gabriel

    2010-01-01

    This shows an on-going project named RAUVI (i.e., Reconfigurable AUV for Intervention). This project aims to design and develop an Underwater Autonomous Robot, able to perceive the environment by means of acoustic and optic sensors, and equipped with a robotic arm in order to autonomously perform simple intervention tasks. A complete simulation environment, including this new concept of robot, has been developed and is presented as a preliminary result.

  15. Active Disturbance Rejection Fuzzy Controller for Roll Stabilization of Autonomous Underwater Vehicle under Wave Disturbance

    OpenAIRE

    Lin-Lin Wang; Hong-Jian Wang; Li-Xin Pan; Jun-Xi Guo

    2015-01-01

    Considering the case of autonomous underwater vehicle navigating with low speed near water surface, a new method for designing of roll motion controller is proposed in order to restrain wave disturbance effectively and improve roll stabilizing performance under different sea conditions. Active disturbance rejection fuzzy control is applied, which is based on nonlinear motion model of autonomous underwater vehicle and the principle of zero-speed fin stabilizer. Extended state observer is used...

  16. Design of and Decentralized Path Planning for Platoons of Miniature Autonomous Underwater Vehicles

    OpenAIRE

    Sylvester, Caleb Allen

    2004-01-01

    Many successful control schemes for land-based or air-based groups, or platoons, of autonomous vehicles cannot be implemented in underwater applications because of their dependence upon high-bandwidth communication. In current strategies for controlling groups of autonomous underwater vehicles (AUVs), platoon size remains limited by communication bandwidth requirements. So, there is great need for advances in low-bandwidth control techniques for arbitrarily large platoons of AUVs. This t...

  17. Analysis and innovation of key technologies for autonomous underwater vehicles

    Institute of Scientific and Technical Information of China (English)

    高富东; 韩艳艳; 王海东; 徐男

    2015-01-01

    As the mission needs of the autonomous underwater vehicles (AUV) have become increasingly varied and complex,the AUVs are developing in the direction of systematism, multifunction, and clustering technology, which promotes the progress of key technologies and proposes a series of technical problems. Therefore, it is necessary to make systemic analysis and in-depth study for the progress of AUV’s key technologies and innovative applications. The multi-functional mission needs and its key technologies involved in complex sea conditions are pointed out through analyzing the domestic and foreign technical programs, functional characteristics and future development plans. Furthermore, the overall design of a multi-moving state AUV is proposed. Then, technical innovations of the key technologies, such as thrust vector, propeller design, kinematics and dynamics, navigation control, and ambient flow field characteristics, are made, combining with the structural characteristics and motion characteristics of the new multi-moving state AUV. The results verify the good performance of the multi-moving state AUV and provide a theoretical guidance and technical support for the design of new AUV in real complex sea conditions.

  18. Ocean outfall plume characterization using an Autonomous Underwater Vehicle.

    Science.gov (United States)

    Rogowski, Peter; Terrill, Eric; Otero, Mark; Hazard, Lisa; Middleton, William

    2013-01-01

    A monitoring mission to map and characterize the Point Loma Ocean Outfall (PLOO) wastewater plume using an Autonomous Underwater Vehicle (AUV) was performed on 3 March 2011. The mobility of an AUV provides a significant advantage in surveying discharge plumes over traditional cast-based methods, and when combined with optical and oceanographic sensors, provides a capability for both detecting plumes and assessing their mixing in the near and far-fields. Unique to this study is the measurement of Colored Dissolved Organic Matter (CDOM) in the discharge plume and its application for quantitative estimates of the plume's dilution. AUV mission planning methodologies for discharge plume sampling, plume characterization using onboard optical sensors, and comparison of observational data to model results are presented. The results suggest that even under variable oceanic conditions, properly planned missions for AUVs equipped with an optical CDOM sensor in addition to traditional oceanographic sensors, can accurately characterize and track ocean outfall plumes at higher resolutions than cast-based techniques. PMID:23306274

  19. Sewage outfall plume dispersion observations with an autonomous underwater vehicle.

    Science.gov (United States)

    Ramos, P; Cunha, S R; Neves, M V; Pereira, F L; Quintaneiro, I

    2005-01-01

    This work represents one of the first successful applications of Autonomous Underwater Vehicles (AUVs) for interdisciplinary coastal research. A monitoring mission to study the shape and estimate the initial dilution of the S. Jacinto sewage outfall plume using an AUV was performed on July 2002. An efficient sampling strategy enabling greater improvements in spatial and temporal range of detection demonstrated that the sewage effluent plume can be clearly traced using naturally occurring tracers in the wastewater. The outfall plume was found at the surface highly influenced by the weak stratification and low currents. Dilution varying with distance downstream was estimated from the plume rise over the outfall diffuser until a nearly constant value of 130:1, 60 m from the diffuser, indicating the near field end. Our results demonstrate that AUVs can provide high-quality measurements of physical properties of effluent plumes in a very effective manner and valuable considerations about the initial mixing processes under real oceanic conditions can be further investigated. PMID:16477997

  20. Terrain aided navigation for autonomous underwater vehicles with coarse maps

    Science.gov (United States)

    Zhou, Ling; Cheng, Xianghong; Zhu, Yixian

    2016-09-01

    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.

  1. Task Allocation and Path Planning for Collaborative Autonomous Underwater Vehicles Operating through an Underwater Acoustic Network

    Directory of Open Access Journals (Sweden)

    Yueyue Deng

    2013-01-01

    Full Text Available Dynamic and unstructured multiple cooperative autonomous underwater vehicle (AUV missions are highly complex operations, and task allocation and path planning are made significantly more challenging under realistic underwater acoustic communication constraints. This paper presents a solution for the task allocation and path planning for multiple AUVs under marginal acoustic communication conditions: a location-aided task allocation framework (LAAF algorithm for multitarget task assignment and the grid-based multiobjective optimal programming (GMOOP mathematical model for finding an optimal vehicle command decision given a set of objectives and constraints. Both the LAAF and GMOOP algorithms are well suited in poor acoustic network condition and dynamic environment. Our research is based on an existing mobile ad hoc network underwater acoustic simulator and blind flooding routing protocol. Simulation results demonstrate that the location-aided auction strategy performs significantly better than the well-accepted auction algorithm developed by Bertsekas in terms of task-allocation time and network bandwidth consumption. We also demonstrate that the GMOOP path-planning technique provides an efficient method for executing multiobjective tasks by cooperative agents with limited communication capabilities. This is in contrast to existing multiobjective action selection methods that are limited to networks where constant, reliable communication is assumed to be available.

  2. Real Time SLAM Using Compressed Occupancy Grids For a Low Cost Autonomous Underwater Vehicle

    OpenAIRE

    Cain, Christopher Hawthorn

    2014-01-01

    The research presented in this dissertation pertains to the development of a real time SLAM solution that can be performed by a low cost autonomous underwater vehicle equipped with low cost and memory constrained computing resources. The design of a custom rangefinder for underwater applications is presented. The rangefinder makes use of two laser line generators and a camera to measure the unknown distance to objects in an underwater environment. A visual odometry algorithm is...

  3. 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.

  4. 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. PMID:22346682

  5. 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. PMID:22346682

  6. Delphin2: an over actuated autonomous underwater vehicle for manoeuvring research

    OpenAIRE

    Philips, A.B.; Steenson, L.V.; Rogers, E.; Turnock, S.R.; Harris, C A; Furlong, M.

    2013-01-01

    Delphin2 is a hover capable torpedo style Autonomous Underwater Vehicle (AUV), developed at the University of Southampton to provide a test bed for research in marine robotics, primarily to enhance the manoeuvring capability of AUVs. This paper describes the mechanical design of the vehicle and its software architecture. The performance of the vehicle is presented as well as preliminary findings from the vehicle’s first fully autonomous video survey issions in Lough Erne, Northern Ireland. I...

  7. Development of a Power System and Analysis of Inertial System Calibration for a Small Autonomous Underwater Vehicle

    OpenAIRE

    Seely, William Forrester

    2004-01-01

    Compared to large vehicles acting individually, platoons of small, inexpensive autonomous underwater vehicles have the potential to perform some missions that are commonly conducted by larger vehicles faster, more efficiently, and at a reduced operational cost. This thesis describes the power system of a small, inexpensive autonomous underwater vehicle developed by the Autonomous Systems Controls Laboratory at Virginia Tech. Reduction in vehicle size and cost reduces the accuracy of navi...

  8. Pipeline tracking for fully-actuated autonomous underwater vehicle using visual servo control

    OpenAIRE

    Krupinsky, Szymon; Allibert, Guillaume; Hua, Minh Duc; Hamel, Tarek

    2012-01-01

    International audience This paper describes a nonlinear image-based visual servo control algorithm for the pipeline tracking problem of a fully-actuated underwater vehicle. The dynamic model of a generic autonomous underwater vehicle (AUV), incorporating all significant forces and torques is developed and a generic velocity control strategy is proposed. The desired velocities in the plane orthogonal to the direction of the pipeline along with the yaw velocity are derived from the image seq...

  9. Design of Neural Network Control System for Controlling Trajectory of Autonomous Underwater Vehicles

    OpenAIRE

    İkbal Eski; Şahin Yıldırım

    2014-01-01

    A neural network based robust control system design for the trajectory of Autonomous Underwater Vehicles (AUVs) is presented in this paper. Two types of control structure were used to control prescribed trajectories of an AUV. The vehicle was tested with random disturbances while taxiing under water. The results of the simulation showed that the proposed neural network based robust control system has superior performance in adapting to large random disturbances such as underwater flow. It is ...

  10. Active Disturbance Rejection Fuzzy Controller for Roll Stabilization of Autonomous Underwater Vehicle under Wave Disturbance

    Directory of Open Access Journals (Sweden)

    Lin-Lin Wang

    2015-01-01

    Full Text Available Considering the case of autonomous underwater vehicle navigating with low speed near water surface, a new method for designing of roll motion controller is proposed in order to restrain wave disturbance effectively and improve roll stabilizing performance under different sea conditions. Active disturbance rejection fuzzy control is applied, which is based on nonlinear motion model of autonomous underwater vehicle and the principle of zero-speed fin stabilizer. Extended state observer is used for estimation of roll motion state and unknown wave disturbance. Wave moment is counteracted by introducing compensation term into the roll control law which is founded on nonlinear feedback. Fuzzy reasoning is used for parameter adjustment of the controller online. Simulation experiments on roll motion are conducted under different sea conditions, and the results show better robustness improved by active disturbance rejection fuzzy controller of autonomous underwater vehicle navigating near water surface.

  11. Online Detection of Mixed Layer Depth for Autonomous Underwater Vehicles

    Science.gov (United States)

    Chu, S.; Estlin, T.; Castano, R.; Woodward, G.; Gierach, M. M.; Thompson, A. F.; Schaffer, S.

    2015-12-01

    The accurate determination of the mixed layer depth (MLD) plays a crucial role in studying ocean dynamics and climate change. Various methods to estimate MLD have been proposed [1, 2]. However there is no current consensus on the best model, which leads to large uncertainty in the estimation. The variability, coupled with the complexity of physical, chemical and biological processes involved and the uncertainty and instabilities of the upper ocean surface, makes estimating MLD a challenging task. MLD varies significantly, even across a small spatial area (autonomous underwater vehicle (AUV). Using an online method permits a more adaptive approach to estimating MLD. Our proposed algorithm is based on an ensemble approach, which includes data mining techniques for real-time peak and change detection, learned seasonal variability profile, combined with MLD estimation criteria in [1]. In this study, we analyze measurements using glider data collected from the OSMOSIS (Ocean Surface Mixing, Ocean Submesoscale Interaction Study) project, concatenated into a year-long time series [3]. The glider data consists of nine full-depth moorings, which were deployed in a 15 km by 15 km box at the Porcupine Abyssal Plain in the northeast Atlantic, centered at 16.2°W, 48.7°N. Our algorithm utilizes direct measurements of salinity, temperature, depth and time and the design is based on the spatial and temporal variability of MLD learned. We will present our initial work on tracking the MLD based on real-time simulations using the OSMOSIS glider data and discussed for the case of deploying on a single AUV. Using an online algorithm for estimating MLD in-situ enables the system to rapidly adapt to the variability in a real-world environment and also allows for the intelligent operation of the limited sampling resources available on an AUV. We will discuss the autonomy architecture and algorithm design for implementing this methodology and present results from our initial

  12. Online Detection of Mixed Layer Depth for Autonomous Underwater Vehicles

    Science.gov (United States)

    Chu, S.; Estlin, T.; Castano, R.; Woodward, G.; Gierach, M. M.; Thompson, A. F.; Schaffer, S.

    2015-12-01

    The accurate determination of the mixed layer depth (MLD) plays a crucial role in studying ocean dynamics and climate change. Various methods to estimate MLD have been proposed [1, 2]. However there is no current consensus on the best model, which leads to large uncertainty in the estimation. The variability, coupled with the complexity of physical, chemical and biological processes involved and the uncertainty and instabilities of the upper ocean surface, makes estimating MLD a challenging task. MLD varies significantly, even across a small spatial area (online algorithm for detecting mixed layer depth that would operate onboard an autonomous underwater vehicle (AUV). Using an online method permits a more adaptive approach to estimating MLD. Our proposed algorithm is based on an ensemble approach, which includes data mining techniques for real-time peak and change detection, learned seasonal variability profile, combined with MLD estimation criteria in [1]. In this study, we analyze measurements using glider data collected from the OSMOSIS (Ocean Surface Mixing, Ocean Submesoscale Interaction Study) project, concatenated into a year-long time series [3]. The glider data consists of nine full-depth moorings, which were deployed in a 15 km by 15 km box at the Porcupine Abyssal Plain in the northeast Atlantic, centered at 16.2°W, 48.7°N. Our algorithm utilizes direct measurements of salinity, temperature, depth and time and the design is based on the spatial and temporal variability of MLD learned. We will present our initial work on tracking the MLD based on real-time simulations using the OSMOSIS glider data and discussed for the case of deploying on a single AUV. Using an online algorithm for estimating MLD in-situ enables the system to rapidly adapt to the variability in a real-world environment and also allows for the intelligent operation of the limited sampling resources available on an AUV. We will discuss the autonomy architecture and algorithm design for

  13. Mechanical Design of a Trawl-Resistant Self-Mooring Autonomous Underwater Vehicle

    OpenAIRE

    Wilson, Taylor Boyde

    2016-01-01

    The Virginia Tech Trawl-Resistant Self-Mooring Autonomous Underwater Vehicle (TRSMAUV) is designed to reside on the seafloor for extended periods of time. The TRSMAUV shape allows for deployment in areas where trawl fisheries are conducted. TRSMAUV is a two stage vehicle. The ingress vehicle is the delivery device, and it is constructed from two symmetric halves. The top half contains the ingress vehicle propulsion system and control surfaces. The bottom half is the trawl-resistant moori...

  14. Cross body thruster control and modeling of a body of revolution Autonomous Underwater Vehicle

    OpenAIRE

    Doherty, Sean Michael.

    2011-01-01

    Approved for public release; distribution is unlimited. Cross body thrusters permit a body of revolution Autonomous Underwater Vehicle to retain the energy efficiency of forward travel while increasing the ability to maneuver in confined areas such as harbors and piers. This maneuverability also permits more deliberate underwater surveys using a fixed, mounted forward and downward looking sonar. This work develops the necessary hydrodynamic coefficients, using methods applied to earlier ve...

  15. Model Predictive Control of a Hybrid Autonomous Underwater Vehicle with Experimental Verification

    OpenAIRE

    Steenson, L.V.; Turnock, S.R.; Phillips, A.B.; Harris, C.; Furlong, M.E.; Rogers, E.; Wang, L.; Bodles, K.; Evans, D. W.

    2014-01-01

    In this work model predictive control is used to provide transit and hover capabilities for an autonomous underwater vehicle where the description of the system dynamics used include terms measured experimentally. The resulting controller manoeuvres the vehicle in the presence of constraints on the actuators and results obtained from the deployment of the vehicle in an inland lake for the study of the Zebra mussel, an invasive species, are also given.

  16. Design, Simulation and Experimental Results of Taipan 300, a New Autonomous Underwater Vehicle Prototype

    OpenAIRE

    Creuze, Vincent; Parodi, Olivier; Xiang, Xianbo

    2009-01-01

    International audience In this paper we present a new small Autonomous Underwater Vehicle (AUV) called Taipan 300. First, we detail its technical features. Then, we explain how the particular hardware design of this vehicle makes its recovery easier in case of software or hardware failure. In fact this prototype offers enhanced safety measures in order to detect computer failure and to facilitate vehicle localization after it has resurfaced. In a third part, we describe the sliding control...

  17. Visual inspection of sea bottom structures by an autonomous underwater vehicle.

    Science.gov (United States)

    Foresti, G L

    2001-01-01

    This paper describes a vision-based system for inspections of underwater structures, e.g., pipelines, cables, etc., by an autonomous underwater vehicle (AUV). Usually underwater inspections are performed by remote operated vehicles (ROVs) driven by human operators placed in a support vessel. However, this task is often challenging, especially in conditions of poor visibility or in presence of strong currents. The system proposed allows the AUV to accomplish the task in autonomy. Moreover, the use of a three-dimensional (3-D) model of the environment and of an extended Kalman filter (EKF) allows the guidance and the control of the vehicle in real time. Experiments done on real underwater images have demonstrated the validity of the proposed method and its efficiency in the case of critical and complex situations. PMID:18244834

  18. An Autonomous Underwater Vehicle Simulation Using Linear Quadratic Servo Based on Open Control Platform

    Directory of Open Access Journals (Sweden)

    Nanang Syahroni

    2012-01-01

    Full Text Available This paper presents an optimal regulator for depth control simulation of an autonomous underwater vehicle (AUV using a new approach of decentralized system environment called open control platform (OCP. Simulation results are presented to demonstrate performance of the proposed method.

  19. Autonomous underwater vehicle pursuit of biological specimens in the open ocean

    OpenAIRE

    Blanco, Max; Wilson, P.A.

    2010-01-01

    The pursuit equations in two-dimensional space are examined, and then parametrised in terms of relative velocity and initial range. Several inferences about the behaviour of these equations are drawn. The burst speed of several fish species are tabulated, along with several types of Autonomous Underwater Vehicle. An example pursuit calculation is described.

  20. Acoustic inversion with self noise of an autonomous underwater vehicle to measure sound speed in marine sediments

    NARCIS (Netherlands)

    A.V. van Leijen; L.J.M. Rothkranz; F.C.A. Groen

    2009-01-01

    This work reports on an experiment from the Maritime Rapid Environmental Assessment sea trials in 2007, where autonomous underwater vehicles were deployed for environmental assessment. Even though these underwater vehicles are very quiet platforms, this work investigates the potential of vehicle sel

  1. Development of an Underwater Gravity Measurement System Using Autonomous Underwater Vehicle

    Science.gov (United States)

    Shinohara, M.; Ishihara, T.; Yamada, T.; Araya, A.; Kanazawa, T.; Fujimoto, H.; Tsukioka, S.; Omika, S.; Uehira, K.; Iizasa, K.

    2015-12-01

    Gravity survey is one of powerful methods to obtain density structure in crust, especially for exploration of underground deposits. Recent technology of autonomous underwater vehicle (AUV) enables us measure gravity in underwater environment. Measurement of both gravity and gravity gradient is useful to estimate structure. From a model calculation, resolution of 0.1 mGal for gravity and 10 Etoves (E) for gradient measurement is needed for detection of seafloor deposits. From these objectives and specification, we have developed an underwater gravity measurement system for exploration below a seafloor using an AUV. For the gravimeter system, a gravimeter is mounted on a levelling mechanism to keep vertical. Depth rating of the system is 4,200 m. We confirmed that our gravity measurement system has an accuracy of less than 0.04 mGal on a land experiment. The gradiometer has two identical gravimeter aligned vertically 44 cm apart. Difference between two gravimeters is calculated for gravity gradient and a levelling system is also used to keep vertical. We estimate accuracy of 10 E from background noise spectra. We chose AUV Urashima belonging to JAMSTEC, because stable navigation is possible. All the power is supplied from the Urashima and acoustic communication system enables real-time monitoring of the system. The first observation was carried out in September 2012 in Sagami-Bay, Japan. The Urashima made round trip along a single profile. We succeeded in obtaining gravity data and other data for compensation. Information to measure gravity gradient is also obtained. After the data processing, our gravity system is estimated to have accuracy of 0.1 mGal. In August 2014, we carried out the second gravity survey using our system in Izena caldera, the middle Okinawa Trough, where seafloor deposits had been found. The Urashima was navigated on 15 profiles in the survey area at constant speed and depth. We obtained the data from both the gravimeter and gradiometer with

  2. Coordinated Formation Control of Multiple Autonomous Underwater Vehicles for Pipeline Inspection

    Directory of Open Access Journals (Sweden)

    Xianbo Xiang

    2010-02-01

    Full Text Available This paper addresses the control problem of inspecting underwater pipeline on the seabed, with coordinated multiple autonomous underwater vehicles in a formation. Based on the leader-follower strategy, the dedicated nonlinear path following controller is rigorously built on Lyapunov-based design, driving a fleet of vehicles onto assigned parallel paths elevated and offset from the underwater pipeline, while keeping a triangle formation to capture complete 3D images for inspection. Due to the spatial-temporal decoupling characteristics of individual path following controller, the velocities of the followers can be adapted in the coordinated control level, only relying on the information of generalized along-path length from the leader, in order to build the desired formation. Thus, the communication variable broadcast from the leader is kept to a minimum, which is feasible under the severely constraints of acoustic communication bandwidth. Simulation results illustrate the efficiency of coordinated formation controller proposed for underwater pipeline inspection.

  3. Modeling and Non-Linear Self-Tuning Robust Trajectory Control of an Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Thor Inge Fossen

    1988-10-01

    Full Text Available A non-linear self-tuning algorithm is demonstrated for an autonomous underwater vehicle. Tighter control is achieved by a non-linear parameter identification algorithm which reduces the parameter uncertainty bounds. Expensive hydrodynamic tests for parameter determination can thus be avoided. Excellent tracking performance and robustness to parameter uncertainty are guaranteed through a robust control strategy based on the estimated parameters. The nonlinear control law is highly robust for imprecise models and the neglected dynamics. The non-linear self-tuning control strategy is simulated for the horizontal positioning of an underwater vehicle.

  4. Design of Neural Network Control System for Controlling Trajectory of Autonomous Underwater Vehicles

    Directory of Open Access Journals (Sweden)

    İkbal Eski

    2014-01-01

    Full Text Available A neural network based robust control system design for the trajectory of Autonomous Underwater Vehicles (AUVs is presented in this paper. Two types of control structure were used to control prescribed trajectories of an AUV. The vehicle was tested with random disturbances while taxiing under water. The results of the simulation showed that the proposed neural network based robust control system has superior performance in adapting to large random disturbances such as underwater flow. It is proved that this kind of neural predictor could be used in real-time AUV applications.

  5. EFFECT OF HYDROPLANE PROFILE ON HYDRODYNAMIC COEFFICIENTS OF AN AUTONOMOUS UNDERWATER VEHICLE

    OpenAIRE

    Ahmad Hajivand; S. Hossein Mousavizadegan; Mohsen Sadeghian; Manochehr Fadavi

    2016-01-01

    AUVs are the most suitable tool for conduction survey concerning with global environmental problems. AUVs maneuverability should be carefully checked so as to improve energy efficiency of the vehicle and avoid unexpected motion. Oblique towing test (OTT) is simulated virtually in a computational fluid dynamic (CFD) environment to obtain hydrodynamic damping coefficients of a full-scale autonomous underwater vehicle. Simulations are performed for bare hull and hull equipped with four different...

  6. Robust Design of Docking Hoop for Recovery of Autonomous Underwater Vehicle with Experimental Results

    OpenAIRE

    Wei Peng Lin; Cheng Siong Chin; Leonard Chin Wai Looi; Jun Jie Lim; Elvin Min Ee Teh

    2015-01-01

    Control systems prototyping is usually constrained by model complexity, embedded system configurations, and interface testing. The proposed control system prototyping of a remotely-operated vehicle (ROV) with a docking hoop (DH) to recover an autonomous underwater vehicle (AUV) named AUVDH using a combination of software tools allows the prototyping process to be unified. This process provides systematic design from mechanical, hydrodynamics, dynamics modelling, control system design, and sim...

  7. Environmental Tracking and Formation Control for an Autonomous Underwater Vehicle Platoon with Limited Communication

    OpenAIRE

    Roberson, David Gray

    2008-01-01

    A platoon of autonomous underwater vehicles provides a compelling platform for studying many challenging issues in multi-agent cooperative control. These challenges include developing cooperative algorithms suitable to practical multi-vehicle applications. They also include addressing intervehicle communication issues, such as sharing information via limited bandwidth channels and selecting network architecture to facilitate control design. This work addresses problems in each of these areas....

  8. Planning the Minimum Time and Optimal Survey Trajectory for Autonomous Underwater Vehicles in Uncertain Current

    OpenAIRE

    Michael A. Hurni; Kiriakos Kiriakidis

    2015-01-01

    The authors develop an approach to a “best” time path for Autonomous Underwater Vehicles conducting oceanographic measurements under uncertain current flows. The numerical optimization tool DIDO is used to compute hybrid minimum time and optimal survey paths for a sample of currents between ebb and flow. A simulated meta-experiment is performed where the vehicle traverses the resulting paths under different current strengths per run. The fastest elapsed time emerges from a payoff table. A mul...

  9. EFFECT OF HYDROPLANE PROFILE ON HYDRODYNAMIC COEFFICIENTS OF AN AUTONOMOUS UNDERWATER VEHICLE

    Directory of Open Access Journals (Sweden)

    Ahmad Hajivand

    2016-03-01

    Full Text Available AUVs are the most suitable tool for conduction survey concerning with global environmental problems. AUVs maneuverability should be carefully checked so as to improve energy efficiency of the vehicle and avoid unexpected motion. Oblique towing test (OTT is simulated virtually in a computational fluid dynamic (CFD environment to obtain hydrodynamic damping coefficients of a full-scale autonomous underwater vehicle. Simulations are performed for bare hull and hull equipped with four different hydroplanes. The hydrodynamic forces and moment are obtained to calculate hydrodynamic coefficients. Nonlinear damping coefficients are also obtained by using suitable curve fitting. Experiments of resistance and OTT are carried out in specific condition, for validation purpose. Following the extracting numerical results a mathematical model is developed to calculate hydrodynamic force for different sail type in order to predict autonomous underwater vehicle (AUV maneuverability. The results shows good agreement between theory and experiment.

  10. Control of Oscillating Foil for Propulsion of Biorobotic Autonomous Underwater Vehicle (AUV

    Directory of Open Access Journals (Sweden)

    S. N. Singh

    2005-01-01

    Full Text Available The paper treats the question of control of a laterally and rotationally oscillating hydrofoil for the propulsion of biologically inspired robotic (biorobotic autonomous underwater vehicles (BAUVs. Sinusoidal oscillations of foils produce maneuvering and propulsive forces. The design is based on the internal model principle. Two springs are used to transmit forces from the actuators to the foil. Oscillating fins produce periodic forces, which can be used for fish-like propulsion and control of autonomous underwater vehicles (AUVs. The equations of motion of the foil include hydrodynamic lift and moment based on linear, unsteady, aerodynamic theory. A control law is derived for the lateral and rotational sinusoidal oscillation of the foil. In the closed-loop system, the lateral displacement and the rotational angle of the foil asymptotically follow sinusoidal trajectories of distinct frequencies and amplitudes independently. Simulation results are presented to show the trajectory tracking performance of the foil for different freestream velocities and sinusoidal command trajectories.

  11. Measurements beneath an Antarctic ice shelf using an autonomous underwater vehicle

    OpenAIRE

    Nicholls, K.W.; Abrahamsen, E.P.; Buck, J.J.H.; P. A. Dodd; Goldblatt, C.; Griffiths, G; K. J. Heywood; Hughes, N.E.; Kaletzky, A.; Lane-Serff, G.F.; McPhail, S.D.; Millard, N. W.; Oliver, K. I. C.; Perrett, J; Price, M. R.

    2006-01-01

    The cavities beneath Antarctic ice shelves are among the least studied regions of the World Ocean, yet they are sites of globally important water mass transformations. Here we report results from a mission beneath Fimbul Ice Shelf of an autonomous underwater vehicle. The data reveal a spatially complex oceanographic environment, an ice base with widely varying roughness, and a cavity periodically exposed to water with a temperature significantly above the surface freezing point. The result...

  12. Surveillance of Marine Resources by use of Stationary Platforms and Autonomous Underwater Vehicle (AUVS)

    OpenAIRE

    Patel, Ruben

    2007-01-01

    In this thesis I investigate, describe and demonstrate new platform technology and its application in fisheries research. The first task was to prepare an Autonomous Underwater Vehicle (AUV) for payload integration (Paper 1). The instrument to be integrated into the AUV was a SIMRAD EK60 scientific echo sounder. Space limitations of the AUV demanded physical modifications. The EK60 software was designed for manual operation. To overcome the associated problem for remote control in accordance ...

  13. Development of linear parameter varying control system for autonomous underwater vehicle

    OpenAIRE

    Sutarto, Herman; Budiyono, Agus

    2011-01-01

    The development and application of Linear Parameter Varying (LPV) control system for robust longitudinal control system on an Autonomous Underwater Vehicle (AUV) are presented. The LPV system is represented as Linear Fractional Transformation (LFT) on its parameter set. The LPV control system combines LPV theory based upon Linear Matrix Inequalities (LMIs) and - synthesis to form a robust LPV control system. The LPV control design is applied for a pitch control of the AUV to fulfill control...

  14. A Behavioral probabilistic risk assessment framework for managing autonomous underwater vehicle deployments

    OpenAIRE

    Brito, Mario; Griffiths, Gwyn; Ferguson, James; Hopkin, David; Mills, Richard; Pederson, Richard; MacNeil, Erin

    2012-01-01

    The deployment of a deep-diving long-range autonomous underwater vehicle (AUV) is a complex operation that requires the use of a risk informed decision-making process. Operational risk assessment is heavily dependent on expert subjective judgment. Expert judgments can be elicited either mathematically or behaviorally. During mathematical elicitation experts are kept separate and provide their assessment individually. These are then mathematically combined to create a judgment that represents ...

  15. Depth Control for Micro-autonomous Underwater Vehicles (μAUVs): Simulation and Experimentation

    OpenAIRE

    Watson, Simon A.; Green, Peter N.

    2014-01-01

    Swarms of micro-autonomous underwater vehicles (μAUVs) are an attractive solution to the problem of nuclear storage pond monitoring. Independent movement in the horizontal and vertical planes is necessary to maximize manoeuvrability. This paper presents a comparison of different control strategies for independent depth control using both simulations and real experimental results. PID, sliding mode and a simplification of sliding mode (called 'bounded PD') are simulated using a MATLAB/SIMULINK...

  16. High resolution study of the spatial distributions of abyssal fishes by autonomous underwater vehicle

    OpenAIRE

    Milligan, R. J.; Morris, K. J.; Bett, B. J.; Durden, J. M.; Jones, D. O. B.; Robert, K; Ruhl, H. A.; Bailey, D. M.

    2016-01-01

    On abyssal plains, demersal fish are believed to play an important role in transferring energy across the seafloor and between the pelagic and benthic realms. However, little is known about their spatial distributions, making it difficult to quantify their ecological significance. To address this, we employed an autonomous underwater vehicle to conduct an exceptionally large photographic survey of fish distributions on the Porcupine Abyssal Plain (NE Atlantic, 4850 m water depth) encompassing...

  17. High resolution study of the spatial distributions of abyssal fishes by autonomous underwater vehicle

    OpenAIRE

    Milligan, R. J.; Morris, K. J.; Bett, B. J.; Durden, J. M.; Jones, D. O. B.; Robert, K; Ruhl, H. A.; Bailey, D. M.

    2016-01-01

    On abyssal plains, demersal fish are believed to play an important role in transferring energy across the seafloor and between the pelagic and benthic realms. However, little is known about their spatial distributions, making it difficult to quantify their ecological significance. To address this, we employed an autonomous underwater vehicle to conduct an exceptionally large photographic survey of fish distributions on the Porcupine Abyssal Plain (NE Atlantic, 4850?m water depth) encompassing...

  18. Oscillatory Adaptive Yaw-Plane Control of Biorobotic Autonomous Underwater Vehicles Using Pectoral-Like Fins

    OpenAIRE

    Mugdha S. Naik; Sahjendra N. Singh

    2007-01-01

    This article considers the control of a biorobotic autonomous underwater vehicle (BAUV) in the yaw plane using biologically inspired oscillatory pectoral-like fins of marine animals. The fins are assumed to be oscillating harmonically with a combined linear (sway) and angular (yaw) motion producing unsteady forces, which are used for fish-like control of BAUVs. Manoeuvring of the BAUV in the yaw plane is accomplished by altering the bias (mean) angle of the angular motion of the fin. For the ...

  19. Control of Oscillating Foil for Propulsion of Biorobotic Autonomous Underwater Vehicle (AUV)

    OpenAIRE

    Singh, S. N.; Mani, S.

    2005-01-01

    The paper treats the question of control of a laterally and rotationally oscillating hydrofoil for the propulsion of biologically inspired robotic (biorobotic) autonomous underwater vehicles (BAUVs). Sinusoidal oscillations of foils produce maneuvering and propulsive forces. The design is based on the internal model principle. Two springs are used to transmit forces from the actuators to the foil. Oscillating fins produce periodic forces, which can be used for fish-like propulsion and control...

  20. Geostatistical Prediction of Ocean Outfall Plume Characteristics Based on an Autonomous Underwater Vehicle

    OpenAIRE

    Patrícia Alexandra Gregório Ramos

    2013-01-01

    Geostatistics has been successfully used to analyze and characterize the spatial variability of environmental properties. Besides giving estimated values at unsampled locations, it provides a measure of the accuracy of the estimate, which is a significant advantage over traditional methods used to assess pollution. In this work universal block kriging is novelty used to model and map the spatial distribution of salinity measurements gathered by an Autonomous Underwater Vehicle in a sea outfal...

  1. Precision control and maneuvering of the Phoenix autonomous underwater vehicle for entering a recovery tube

    OpenAIRE

    Davis, Duane T.

    1996-01-01

    Because of range limitations imposed by speed and power supplies, covert launch and recovery of Autonomous Underwater Vehicles (AUVs) near the operating area will be required for their use in many military applications. This thesis documents the implementation of precision control and planning facilities on the Phoenix AUV that will be required to support recovery in a small tube and provides a preliminary study of issues involved with AUV recovery by submarines. Implementation involves the d...

  2. Real-time scheduling and synchronization for the NPS Autonomous Underwater Vehicle

    OpenAIRE

    Makris, Dionysios

    1991-01-01

    The work described in this thesis is part of a multi-year research project to develop an Autonomous Underwater Vehicle (AUV-II), which is an intelligent robot submarine, carried out by the Departments of Mechanical Engineering, Computer Science, and Electrical and Computer Engineering of the Naval Postgraduate School. The AUV-II on-board computer must perform several different tasks such as navigation, autopilot, guidance, sonar processing and collision avoidance, etc., under strict timing c...

  3. An optimal consensus tracking control algorithm for autonomous underwater vehicles with disturbances

    OpenAIRE

    Zhang, Jian Yuan Wen-Xia; Zhou, Zhou-Hai

    2012-01-01

    The optimal disturbance rejection control problem is considered for consensus tracking systems affected by external persistent disturbances and noise. Optimal estimated values of system states are obtained by recursive filtering for the multiple autonomous underwater vehicles modeled to multi-agent systems with Kalman filter. Then the feedforward-feedback optimal control law is deduced by solving the Riccati equations and matrix equations. The existence and uniqueness condition of feedforward...

  4. Towards efficient benthic survey design with the use of Autonomous Underwater Vehicles

    OpenAIRE

    Singh, Warsha, 1978-

    2015-01-01

    This research work contributes towards improvement of stock assessment techniques for macrobenthic organisms in Icelandic waters with the use of an autonomous underwater vehicle (AUV) as a survey tool for population assessments, and through considering ways in which designs of such surveys can be made more efficient. The Iceland scallop Chlamys islandica (O.F. Muller) population in West Iceland was used as an instructive example to develop the use of a Gavia AUV for benthic research purposes ...

  5. A new method for ecological surveying of the abyss using autonomous underwater vehicle photography

    OpenAIRE

    Morris, Kirsty J.; Bett, Brian J.; Durden, Jennifer M.; Huvenne, Veerle A. I.; Milligan, Rosanna; Jones, Daniel O.B.; McPhail, Stephen; Robert, Katleen; Bailey, David M.; Ruhl, Henry A.

    2014-01-01

    The extent and speed of marine environmental mapping is increasing quickly with technological advances, particularly with optical imaging from autonomous underwater vehicles (AUVs). This contribution describes a new deep-sea digital still camera system that takes high-frequency (>1 Hz) color photographs of the seafloor, suitable for detailed biological and habitat assessment, and the means of efficient processing of this mass imagery, to allow assessment across a wide range of spatial scales ...

  6. A behavior-based scheme using reinforcement learning for autonomous underwater vehicles

    OpenAIRE

    Carreras Pérez, Marc; Yuh, Junku; Batlle i Grabulosa, Joan; Ridao Rodríguez, Pere

    2005-01-01

    This paper presents a hybrid behavior-based scheme using reinforcement learning for high-level control of autonomous underwater vehicles (AUVs). Two main features of the presented approach are hybrid behavior coordination and semi on-line neural-Q_learning (SONQL). Hybrid behavior coordination takes advantages of robustness and modularity in the competitive approach as well as efficient trajectories in the cooperative approach. SONQL, a new continuous approach of the Q_learning algorithm with...

  7. Design of a Low Reynolds Number Propulsion System for an Autonomous Underwater Vehicle

    OpenAIRE

    Portner, Stephen Michael

    2014-01-01

    A methodology for the design of small autonomous underwater vehicle propulsion systems has been developed and applied to the Virginia Tech 690 AUV. The methodology is novel in that it incorporates fast design level codes capable of predicting the viscous effects of low Reynolds number flow that is experienced by small, slow turning propellers. The methodology consists of determining the minimum induced loss lift distribution for the propeller via lifting line theory, efficient airfoil section...

  8. Coordination of Multiple Biomimetic Autonomous Underwater Vehicles Using Strategies Based on the Schooling Behaviour of Fish

    Directory of Open Access Journals (Sweden)

    Jonathan McColgan

    2016-01-01

    Full Text Available Biomimetic Autonomous Underwater Vehicles (BAUVs are Autonomous Underwater Vehicles (AUVs that employ similar propulsion and steering principles as real fish. While the real life applicability of these vehicles has yet to be fully investigated, laboratory investigations have demonstrated that at low speeds, the propulsive mechanism of these vehicles is more efficient when compared with propeller based AUVs. Furthermore, these vehicles have also demonstrated superior manoeuvrability characteristics when compared with conventional AUVs and Underwater Glider Systems (UGSs. Further performance benefits can be achieved through coordination of multiple BAUVs swimming in formation. In this study, the coordination strategy is based on the schooling behaviour of fish, which is a decentralized approach that allows multiple AUVs to be self-organizing. Such a strategy can be effectively utilized for large spatiotemporal data collection for oceanic monitoring and surveillance purposes. A validated mathematical model of the BAUV developed at the University of Glasgow, RoboSalmon, is used to represent the agents within a school formation. The performance of the coordination algorithm is assessed through simulation where system identification techniques are employed to improve simulation run time while ensuring accuracy is maintained. The simulation results demonstrate the effectiveness of implementing coordination algorithms based on the behavioural mechanisms of fish to allow a group of BAUVs to be considered self-organizing.

  9. Onboard assessment of XRF spectra using genetic algorithms for decision making on an autonomous underwater vehicle

    International Nuclear Information System (INIS)

    In order to optimise use of the limited resources (time, power) of an autonomous underwater vehicle (AUV) with a miniaturised X-ray fluorescence (XRF) spectrometer on board to carry out in situ autonomous chemical mapping of the surface of sediments with desired resolution, a genetic algorithm for rapid curve fitting is reported in this paper. This method quickly converges and provides an accurate in situ assessment of metals present, which helps the control system of the AUV to decide on future sampling locations. More thorough analysis of the available data could be performed once the AUV has returned to the base (laboratory).

  10. Onboard assessment of XRF spectra using genetic algorithms for decision making on an autonomous underwater vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Breen, Jeremy [Tasmanian Information and Communication Technologies Centre, Commonwealth Scientific and Industrial Research Organisation, GPO Box 1538, Hobart, TAS (Australia); School of Computing and Information Systems, University of Tasmania, Hobart, TAS (Australia); Souza, P. de, E-mail: paulo.desouza@csiro.au [Tasmanian Information and Communication Technologies Centre, Commonwealth Scientific and Industrial Research Organisation, GPO Box 1538, Hobart, TAS (Australia); Timms, G.P. [Tasmanian Information and Communication Technologies Centre, Commonwealth Scientific and Industrial Research Organisation, GPO Box 1538, Hobart, TAS (Australia); Ollington, R. [School of Computing and Information Systems, University of Tasmania, Hobart, TAS (Australia)

    2011-06-15

    In order to optimise use of the limited resources (time, power) of an autonomous underwater vehicle (AUV) with a miniaturised X-ray fluorescence (XRF) spectrometer on board to carry out in situ autonomous chemical mapping of the surface of sediments with desired resolution, a genetic algorithm for rapid curve fitting is reported in this paper. This method quickly converges and provides an accurate in situ assessment of metals present, which helps the control system of the AUV to decide on future sampling locations. More thorough analysis of the available data could be performed once the AUV has returned to the base (laboratory).

  11. Design and evaluation of a hierarchical control architecture for an autonomous underwater vehicle

    Institute of Scientific and Technical Information of China (English)

    BIAN Xin-qian; QIN Zheng; YAN Zhe-ping

    2008-01-01

    This paper researches on a kind of control architecture for autonomous underwater vehicle (AUV). After describing the hybrid property of the AUV control system, we present the hierarchical AUV control architecture. The architecture is organized in three layers: mission layer, task layer and execution layer. State supervisor and task coordinator are two key modules handling discrete events, so we describe these two modules in detail. Finally, we carried out a series of tests to verify this architecture. The test results show that the AUV can perform autonomous missions effectively and safely. We can conclude the control architecture is valid and practical.

  12. Planning the Minimum Time and Optimal Survey Trajectory for Autonomous Underwater Vehicles in Uncertain Current

    Directory of Open Access Journals (Sweden)

    Michael A. Hurni

    2015-12-01

    Full Text Available The authors develop an approach to a “best” time path for Autonomous Underwater Vehicles conducting oceanographic measurements under uncertain current flows. The numerical optimization tool DIDO is used to compute hybrid minimum time and optimal survey paths for a sample of currents between ebb and flow. A simulated meta-experiment is performed where the vehicle traverses the resulting paths under different current strengths per run. The fastest elapsed time emerges from a payoff table. A multi-objective function is then used to weigh the time to complete a mission versus measurement inaccuracy due to deviation from the desired survey path.

  13. Autonomous Planning and Replanning for Mine-Sweeping Unmanned Underwater Vehicles

    Science.gov (United States)

    Gaines, Daniel M.

    2010-01-01

    This software generates high-quality plans for carrying out mine-sweeping activities under resource constraints. The autonomous planning and replanning system for unmanned underwater vehicles (UUVs) takes as input a set of prioritized mine-sweep regions, and a specification of available UUV resources including available battery energy, data storage, and time available for accomplishing the mission. Mine-sweep areas vary in location, size of area to be swept, and importance of the region. The planner also works with a model of the UUV, as well as a model of the power consumption of the vehicle when idle and when moving.

  14. Computing energy-optimal trajectories for an autonomous underwater vehicle using direct shooting

    Directory of Open Access Journals (Sweden)

    Inge Spangelo

    1992-07-01

    Full Text Available Energy-optimal trajectories for an autonomous underwater vehicle can be computed using a numerical solution of the optimal control problem. The vehicle is modeled with the six dimensional nonlinear and coupled equations of motion, controlled with DC-motors in all degrees of freedom. The actuators are modeled and controlled with velocity loops. The dissipated energy is expressed in terms of the control variables as a nonquadratic function. Direct shooting methods, including control vector parameterization (CVP arc used in this study. Numerical calculations are performed and good results are achieved.

  15. On-line identification of the speed, steering and diving response parameters of an autonomous underwater vehicle from experimental data

    OpenAIRE

    Bahrke, Fredric G.

    1992-01-01

    Approved for public release; distribution is unlimited. The experimental response data from autonomous maneuvering using the NPS AUV II vehicle has been analyzed with a view to defining Kalman filters to provide on-line estimates of system parameters and their variability. Kalman filters, designed for parameter estimation are expected to be the first step in the development of autonomous fault detection systems for underwater vehicles. Secondly, extraction of vehicle hydrodynamic coefficie...

  16. Synthesis of a PID-controller of a trim robust control system of an autonomous underwater vehicle

    Science.gov (United States)

    Khozhaev, I. V.; Gayvoronskiy, S. A.

    2016-04-01

    Autonomous underwater vehicles are often used for performing scientific, emergency or other types of missions under harsh conditions and environments, which can have non-stable, variable parameters. So, the problem of developing autonomous underwater vehicle motion control systems, capable of operating properly in random environments, is highly relevant. The paper is dedicated to the synthesis of a PID-controller of a trim robust control system, capable of keeping an underwater vehicle stable during a translation at different angles of attack. In order to synthesize the PID-controller, two problems were solved: a new method of synthesizing a robust controller was developed and a mathematical model of an underwater vehicle motion process was derived. The newly developed mathematical model structure is simpler than others due to acceptance of some of the system parameters as interval ones. The synthesis method is based on a system poles allocation approach and allows providing the necessary transient process quality in a considered system.

  17. High spatial resolution mapping of water quality and bathymetry with an autonomous underwater vehicle

    Science.gov (United States)

    Pampalone, Vincenzo; Milici, Barbara

    2015-12-01

    The drone Ecomapper AUV (Autonomous Underwater Vehicle) is a rare example of highly technological instrument in the environmental coastal monitoring field. The YSI EcoMapper is a one-man deployable, Autonomous Underwater Vehicle (AUV) designed to collect bathymetry and water quality data. The submarine-like vehicle follows a programmed course and employs sensors mounted in the nose to record pertinent information. Once the vehicle has started its mission, it operates independently of the user and utilizes GPS waypoints navigation to complete its programmed course. Throughout the course, the vehicle constantly steers toward the line drawn in the mission planning software (VectorMap), essentially following a more accurate road of coordinates instead of transversing waypoint-to-waypoint. It has been equipped with a Doppler Velocity Log (DVL) to increase its underwater navigation accuracy. Potential EcoMapper applications include baseline environmental mapping in freshwater, estuarine or near-coastal environments, bathymetric mapping, dissolved oxygen studies, event monitoring (algal blooms, storm impacts, low dissolved oxygen), non-point source studies, point-source dispersion mapping, security, search & rescue, inspection, shallow water mapping, thermal dissipation mapping of cooling outfalls, trace-dye studies. The AUV is used in the coastal area of the Augusta Bay (Italy), located in the eastern part of Sicily. Due to the heavy contamination generated by the several chemical and petrochemical industries active in the zone, the harbour was declared a Contaminated Site of National Interest. The ecomapper allows for a simultaneous data collection of water quality and bathymetric data providing a complete environmental mapping system of the Harbour.

  18. 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. PMID:23145694

  19. TWIST SPRINGBACK MEASUREMENT OF AUTONOMOUS UNDERWATER VEHICLE PROPELLER BLADE BASED ON PROFILE DEVIATION

    Directory of Open Access Journals (Sweden)

    Ahmad Baharuddin Abdullah

    2013-01-01

    Full Text Available Geometrical defects that are attributable to springback are among the major defects induced by the sheet metal forming process. Such defects are critical for sections with varying thickness, such as Autonomous Underwater Vehicle (AUV propeller blades. In this study, the springback in the twist-bending of an AA6061 propeller blade was quantified by comparing the targeted and manufactured profiles obtained using the commercial three-dimensional surface measurement technique. The results show that the twist springback becomes larger as the twist angle increases. Similarly, the twist springback increases with increasing deformation ratio.

  20. An optimal consensus tracking control algorithm for autonomous underwater vehicles with disturbances

    CERN Document Server

    Zhang, Jian Yuan Wen-Xia

    2012-01-01

    The optimal disturbance rejection control problem is considered for consensus tracking systems affected by external persistent disturbances and noise. Optimal estimated values of system states are obtained by recursive filtering for the multiple autonomous underwater vehicles modeled to multi-agent systems with Kalman filter. Then the feedforward-feedback optimal control law is deduced by solving the Riccati equations and matrix equations. The existence and uniqueness condition of feedforward-feedback optimal control law is proposed and the optimal control law algorithm is carried out. Lastly, simulations show the result is effectiveness with respect to external persistent disturbances and noise.

  1. Containment control of networked autonomous underwater vehicles: A predictor-based neural DSC design.

    Science.gov (United States)

    Peng, Zhouhua; Wang, Dan; Wang, Wei; Liu, Lu

    2015-11-01

    This paper investigates the containment control problem of networked autonomous underwater vehicles in the presence of model uncertainty and unknown ocean disturbances. A predictor-based neural dynamic surface control design method is presented to develop the distributed adaptive containment controllers, under which the trajectories of follower vehicles nearly converge to the dynamic convex hull spanned by multiple reference trajectories over a directed network. Prediction errors, rather than tracking errors, are used to update the neural adaptation laws, which are independent of the tracking error dynamics, resulting in two time-scales to govern the entire system. The stability property of the closed-loop network is established via Lyapunov analysis, and transient property is quantified in terms of L2 norms of the derivatives of neural weights, which are shown to be smaller than the classical neural dynamic surface control approach. Comparative studies are given to show the substantial improvements of the proposed new method. PMID:26506019

  2. Robust Design of Docking Hoop for Recovery of Autonomous Underwater Vehicle with Experimental Results

    Directory of Open Access Journals (Sweden)

    Wei Peng Lin

    2015-12-01

    Full Text Available Control systems prototyping is usually constrained by model complexity, embedded system configurations, and interface testing. The proposed control system prototyping of a remotely-operated vehicle (ROV with a docking hoop (DH to recover an autonomous underwater vehicle (AUV named AUVDH using a combination of software tools allows the prototyping process to be unified. This process provides systematic design from mechanical, hydrodynamics, dynamics modelling, control system design, and simulation to testing in water. As shown in a three-dimensional simulation of an AUVDH model using MATLAB™/Simulink™ during the launch and recovery process, the control simulation of a sliding mode controller is able to control the positions and velocities under the external wave, current, and tether forces. In the water test using the proposed Python-based GUI platform, it shows that the AUVDH is capable to perform station-keeping under the external disturbances.

  3. Current State of Technology of Fuel Cell Power Systems for Autonomous Underwater Vehicles

    Directory of Open Access Journals (Sweden)

    Alejandro Mendez

    2014-07-01

    Full Text Available Autonomous Underwater Vehicles (AUVs are vehicles that are primarily used to accomplish oceanographic research data collection and auxiliary offshore tasks. At the present time, they are usually powered by lithium-ion secondary batteries, which have insufficient specific energies. In order for this technology to achieve a mature state, increased endurance is required. Fuel cell power systems have been identified as an effective means to achieve this endurance but no implementation in a commercial device has yet been realized. This paper summarizes the current state of development of the technology in this field of research. First, the most adequate type of fuel cell for this application is discussed. The prototypes and design concepts of AUVs powered by fuel cells which have been developed in the last few years are described. Possible commercial and experimental fuel cell stack options are analyzed, examining solutions adopted in the analogous aerial vehicle applications, as well as the underwater ones, to see if integration in an AUV is feasible. Current solutions in oxygen and hydrogen storage systems are overviewed and energy density is objectively compared between battery power systems and fuel cell power systems for AUVs. A couple of system configuration solutions are described including the necessary lithium-ion battery hybrid system. Finally, some closing remarks on the future of this technology are given.

  4. Design and analysis of an underwater inductive coupling power transfer system for autonomous underwater vehicle docking applications

    Institute of Scientific and Technical Information of China (English)

    Jian-guang SHI; De-jun LI; Can-jun YANG

    2014-01-01

    We develop a new kind of underwater inductive coupling power transfer (ICPT) system to evaluate wireless power transfer in autonomous underwater vehicle (AUV) docking applications. Parameters that determine the performance of the system are systematically analyzed through mathematical methods. A circuit simulation model and a finite element analysis (FEA) sim-ulation model are developed to study the power losses of the system, including copper loss in coils, semiconductor loss in circuits, and eddy current loss in transmission media. The characteristics of the power losses can provide guidelines to improve the effi-ciency of ICPT systems. Calculation results and simulation results are validated by relevant experiments of the prototype system. The output power of the prototype system is up to 45 W and the efficiency is up to 0.84. The preliminary results indicate that the efficiency will increase as the transmission power is raised by increasing the input voltage. When the output power reaches 500 W, the efficiency is expected to exceed 0.94. The efficiency can be further improved by choosing proper semiconductors and coils. The analysis methods prove effective in predicting the performance of similar ICPT systems and should be useful in designing new systems.

  5. Integration of a Strapdown Gravimeter System in AN Autonomous Underwater Vehicle

    Science.gov (United States)

    Roussel, C.; Verdun, J.; Cali, J.; Maia, M.; d'EU, J. F.

    2015-04-01

    We present a new mobile instrument for measuring dynamically the gravity vector and its gradients in underwater environment, named GRAVIMOB. Our instrument is a strapdown sensor, consisted of electrostatic accelerometers installed in a waterproof sphere. It is designed to be embedded in an Autonomous Underwater Vehicle (AUV). Since the positioning of an AUV is approximate in underwater environment, the key issue raised here is to estimate the uncertainty in the gravity field resulting from the use of such position data. This paper focuses on the assessment of the system performances. The latter have been studied by simulation with reference data calculated from actual submarine geological structures, on which different noise models have been added. Results show that spatial evolutions of the gravity field and statistical properties of stochastic processes affecting the measurements have to be considered carefully in order the minimize the error. The Unscented Kalman Filter (UKF) has been favored to the Extended Kalman Filter (EKF) by its ease of implementation and its better robustness to non-linearities.

  6. A conceptual design study of a hovering system controller for an Autonomous Underwater Vehicle

    OpenAIRE

    Thompson, Chris A.

    1987-01-01

    Approved for public release; distribution is unlimited. Hovering, Stationkeeping, Underwater Vehicles, Control Systems, Configurations, Control, Horsepower, Oceans, Position (Location), Redundancy, Scenarios, Theses, Thrusters, Transitions Hovering, Stationkeeping, Underwater Vehicles, Control Systems, Configurations, Control, Horsepower, Oceans, Position (Location), Redundancy, Scenarios, Theses, Thrusters, Transitions http://archive.org/details/conceptualdesign00thom Lieutenant Com...

  7. Sonar-based iceberg-relative navigation for autonomous underwater vehicles

    Science.gov (United States)

    Kimball, Peter; Rock, Stephen

    2011-06-01

    Iceberg-relative navigation for autonomous underwater vehicles (AUVs) will enable a new mode of data collection for studies of free-floating icebergs. Compared to current data collection methods, autonomous underwater vehicles offer substantially expanded coverage area and continuous sampling. However, because icebergs translate and rotate through inertial space, standard vehicle navigation methods which rely on inertial sensors are unable to provide iceberg-relative position estimates. Presented here is a new iceberg-relative vehicle navigation technique which is an extension of existing work in terrain-relative navigation. The technique comprises a mapping step and localization step, each of which is modified here to account for the translation and the rotation of free-floating icebergs. In the mapping step, the AUV circumnavigates the iceberg at a sequence of constant depths, collecting multibeam sonar imagery of the iceberg's submerged surface. A map is then generated in post-processing by projecting these sonar data from their corresponding vehicle positions (accounting for iceberg motion) in a frame that is fixed to the iceberg. Overlapping sonar data from the beginning and end of a circumnavigation provide the information necessary to enforce self-consistency of the iceberg map. In the localization step, the AUV uses the previously generated map to determine its position and orientation with respect to the iceberg by correlating incoming sonar ranges with the map. The estimator works by maintaining explicit estimates not only of the vehicle position and orientation, but also of the iceberg translation and rotation rates through inertial space. Results from a proof-of-concept field demonstration of this new iceberg-relative AUV navigation technique prove the feasibility of both generating a self-consistent three-dimensional map of a moving iceberg and localizing a vehicle's position with respect to that iceberg. The data for the experiment were collected

  8. PARAMETRIC IDENTIFICATION AND SENSITIVITY ANALYSIS FOR AUTONOMOUS UNDERWATER VEHICLES IN DIVING PLANE

    Institute of Scientific and Technical Information of China (English)

    XU Feng; ZOU Zao-jian; YIN Jian-chuan; CAO Jian

    2012-01-01

    The inherent strongly nonlinear and coupling performance of the Autonomous Underwater Vehicles (AUV),maneuvering motion in the diving plane determines its difficulty in parametric identification.The motion parameters in diving plane are obtained by executing the Zigzag-like motion based on a mathematical model of maneuvering motion.A separate identification method is put forward for parametric identification by investigating the motion equations.Support vector machine is proposed to estimate the hydrodynamic derivatives by analyzing the data of surge,heave and pitch motions.Compared with the standard coefficients,the identified parameters show the validation of the proposed identification method.Sensitivity analysis based on numerical simulation demonstrates that poor sensitive derivative gives bad estimation results.Finally the motion simulation is implemented based on the dominant sensitive derivatives to verify the reconstructed model.

  9. Robust Control Based on Feedback Linearization for Roll Stabilizing of Autonomous Underwater Vehicle Under Wave Disturbances

    Institute of Scientific and Technical Information of China (English)

    PAN Li-xin; JIN Hong-zhang; WANG Lin-lin

    2011-01-01

    In the case of Autonomous Underwater Vehicle (AUV) navigating with low speed near water surface, a new method for design of roll motion controller is proposed in order to restrain wave disturbance effectively and improve roll stabilizing performance. Robust control is applied, which is based on uncertain nonlinear horizontal motion model of AUV and the principle of zero speed fin stabilizer. Feedback linearization approach is used to transform the complex nonlinear system into a comparatively simple linear system. For parameter uncertainty of motion model, the controller is designed with mixed-sensitivity method based on H-infinity robust control theory. Simulation results show better robustness improved by this control method for roll stabilizing of AUV navigating near water surface.

  10. Geostatistical Prediction of Ocean Outfall Plume Characteristics Based on an Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Patrícia Alexandra Gregório Ramos

    2013-07-01

    Full Text Available Geostatistics has been successfully used to analyse and characterize the spatial variability of environmental properties. Besides providing estimated values at unsampled locations, geostatistics measures the accuracy of the estimate, which is a significant advantage over traditional methods used to assess pollution. This work uses universal block kriging to model and map the spatial distribution of salinity measurements gathered by an Autonomous Underwater Vehicle in a sea outfall monitoring campaign. The aim is to distinguish the effluent plume from the receiving waters, characterizing its spatial variability in the vicinity of the discharge and estimating dilution. The results demonstrate that geostatistical methodology can provide good estimates of the dispersion of effluents, which are valuable in assessing the environmental impact and managing sea outfalls. Moreover, since accurate measurements of the plume’s dilution are rare, these studies may be very helpful in the future to validate dispersion models.

  11. Linking glacially modified waters to catchment-scale subglacial discharge using autonomous underwater vehicle observations

    Science.gov (United States)

    Stevens, Laura A.; Straneo, Fiamma; Das, Sarah B.; Plueddemann, Albert J.; Kukulya, Amy L.; Morlighem, Mathieu

    2016-02-01

    Measurements of near-ice (autonomous underwater vehicle as close as 150 m from the ice-ocean interface of the Saqqarliup sermia-Sarqardleq Fjord system, West Greenland, with modeled and observed subglacial discharge locations and magnitudes. We find evidence of two main types of subsurface glacially modified water (GMW) with distinct properties and locations. The two GMW locations also align with modeled runoff discharged at separate locations along the grounded margin corresponding with two prominent subcatchments beneath Saqqarliup sermia. Thus, near-ice observations and subglacial discharge routing indicate that runoff from this glacier occurs primarily at two discrete locations and gives rise to two distinct glacially modified waters. Furthermore, we show that the location with the largest subglacial discharge is associated with the lighter, fresher glacially modified water mass. This is qualitatively consistent with results from an idealized plume model.

  12. Modifications of Control Loop to Improve the Depth Response of Autonomous Underwater Vehicles

    Directory of Open Access Journals (Sweden)

    Sheng-Ping Hsu

    2014-01-01

    Full Text Available During a constant depth maneuver of an autonomous underwater vehicle (AUV, its pitch attitude and stern plane deflections create forces and moments to achieve equilibrium in the vertical plane. If an AUV has a proportional controller only in its depth control loop, then different weights or centers of gravity will cause different steady-state depth errors at trimmed conditions. In general, a steady-state depth error can be eliminated by adding an integral controller in the depth control loop. However, an improper integrator may lead to a bad transient response, even though the steady-state depth error can finally be eliminated. To remove the steady-state depth error, this study proposes methods that adjust the depth command and add a switching integral controller in the depth control loop. Simulation results demonstrate that the steady-state depth error can be eliminated and the transient response can be improved.

  13. Implementation of Sliding Mode Observer Based Reconfiguration in an Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    A. J. Mitchell

    2005-01-01

    Full Text Available This paper looks at the implementation of a Sliding Mode Observer (SMO based Reconfiguration algorithm to deal with sensor faults within the context of navigation controllers for Autonomous Underwater Vehicle (AUV. In this paper the reconfigurability aspects are considered for the heading controller. Simulation responses are used to illustrate that the Sliding Mode Observer is able to give state information to the controller when there is a fault in the AUV’s sensor package. Comparisons are made between the Sliding Mode Controller with and without reconfigurability for a number of different sensor failures, e.g. bias errors in or the complete loss of the heading data, and the robustness of the Sliding Mode Observer is investigated through the introduction of disturbances into the system. 

  14. Subsea Cable Tracking by Autonomous Underwater Vehicle with Magnetic Sensing Guidance.

    Science.gov (United States)

    Xiang, Xianbo; Yu, Caoyang; Niu, Zemin; Zhang, Qin

    2016-01-01

    The changes of the seabed environment caused by a natural disaster or human activities dramatically affect the life span of the subsea buried cable. It is essential to track the cable route in order to inspect the condition of the buried cable and protect its surviving seabed environment. The magnetic sensor is instrumental in guiding the remotely-operated vehicle (ROV) to track and inspect the buried cable underseas. In this paper, a novel framework integrating the underwater cable localization method with the magnetic guidance and control algorithm is proposed, in order to enable the automatic cable tracking by a three-degrees-of-freedom (3-DOF) under-actuated autonomous underwater vehicle (AUV) without human beings in the loop. The work relies on the passive magnetic sensing method to localize the subsea cable by using two tri-axial magnetometers, and a new analytic formulation is presented to compute the heading deviation, horizontal offset and buried depth of the cable. With the magnetic localization, the cable tracking and inspection mission is elaborately constructed as a straight-line path following control problem in the horizontal plane. A dedicated magnetic line-of-sight (LOS) guidance is built based on the relative geometric relationship between the vehicle and the cable, and the feedback linearizing technique is adopted to design a simplified cable tracking controller considering the side-slip effects, such that the under-actuated vehicle is able to move towards the subsea cable and then inspect its buried environment, which further guides the environmental protection of the cable by setting prohibited fishing/anchoring zones and increasing the buried depth. Finally, numerical simulation results show the effectiveness of the proposed magnetic guidance and control algorithm on the envisioned subsea cable tracking and the potential protection of the seabed environment along the cable route. PMID:27556465

  15. Exploration of Teisi Knoll by Autonomous Underwater Vehicle "R-One Robot"

    Science.gov (United States)

    Ura, Tamaki; Obara, Takashi; Nagahashi, Kenji; Nakane, Kenji; Sakai, Shoji; Oyabu, Yuji; Sakamaki, Takashi; Takagawa, Shinichi; Kawano, Hiroshi; Gamo, Toshitaka; Takano, Michiaki; Doi, Takashi

    This paper outlines the exploration of Teisi Knoll by the autonomous underwater vehicle the R-One Robot, as carried out October 19-22, 2000, and presents images taken by the sidescan SONAR fitted to the bottom of the vehicle. The R-One Robot was launched from the R/V Kaiyo, started diving near the support ship, followed predetermined tracklines which were defined by waypoints, and finally came back to the destination where it was recovered by the support vessel. In order to minimize positioning error, which is determined by the inertial navigation system and Doppler SONAR, the robot ascended to the surface several times to ascertain its precise position using the global positioning system, the antenna of which is fitted on the vertical fin. Taking advantage of this positioning system, the robot followed the predetermined tracklines with an error of less than 40 meters in 30 minutes of continuous submerging. Disturbance to the robot is small enough compared to towed vehicles that its movement can be regarded as stable. This stability resulted in clear side scanning images of the knoll and surrounding sea floor. The robot stopped at the center of the knoll, and descended vertically into the crater. When the vehicle was in the crater, anomalous manganese ion concentrations were detected by the in situ trace metal micro-analyzer GAMOS, which was loaded in the payload bay at the front of the robot.

  16. 3D Photo Mosaicing of Tagiri Shallow Vent Field by an Autonomous Underwater Vehicle

    Science.gov (United States)

    Maki, Toshihiro; Kondo, Hayato; Ura, Tamaki; Sakamaki, Takashi; Mizushima, Hayato; Yanagisawa, Masao

    Although underwater visual observation is an ideal method for detailed survey of seafloors, it is currently a costly process that requires the use of Remotely Operated Vehicles (ROVs) or Human Occupied Vehicles (HOVs), and can cover only a limited area. This paper proposes an innovative method to navigate an autonomous underwater vehicle (AUV) to create both 2D and 3D photo mosaics of seafloors with high positioning accuracy without using any vision-based matching. The vehicle finds vertical pole-like acoustic reflectors to use as positioning landmarks using a profiling sonar based on a SLAM (Simultaneous Localization And Mapping) technique. These reflectors can be either artificial or natural objects, and so the method can be applied to shallow vent fields where conventional acoustic positioning is difficult, since bubble plumes can also be used as landmarks as well as artificial reflectors. Path-planning is performed in real-time based on the positions and types of landmarks so as to navigate safely and stably using landmarks of different types (artificial reflector or bubble plume) found at arbitrary times and locations. Terrain tracker switches control reference between depth and altitude from the seafloor based on a local map of hazardous area created in real-time using onboard perceptual sensors, in order to follow rugged terrains at an altitude of 1 to 2 meters, as this range is ideal for visual observation. The method was implemented in the AUV Tri-Dog 1 and experiments were carried out at Tagiri vent field, Kagoshima Bay in Japan. The AUV succeeded in fully autonomous observation for more than 160 minutes to create a photo mosaic with an area larger than 600 square meters, which revealed the spatial distribution of detailed features such as tube-worm colonies, bubble plumes and bacteria mats. A fine bathymetry of the same area was also created using a light-section ranging system mounted on the vehicle. Finally a 3 D representation of the environment was

  17. Using Autonomous Underwater Vehicles as Sensor Platforms for Ice-Monitoring

    Directory of Open Access Journals (Sweden)

    Petter Norgren

    2014-10-01

    Full Text Available Due to the receding sea-ice extent in the Arctic, and the potentially large undiscovered petroleum resources present north of the Arctic circle, offshore activities in ice-infested waters are increasing. Due to the presence of drifting sea-ice and icebergs, ice management (IM becomes an important part of the offshore operation, and an important part of an IM system is the ability to reliably monitor the ice conditions. An autonomous underwater vehicle (AUV has a unique capability of high underwater spatial and temporal coverage, making it suitable for monitoring applications. Since the first Arctic AUV deployment in 1972, AUV technology has matured and has been used in complex under-ice operations. This paper motivates the use of AUVs as an ice-monitoring sensor platform. It discusses relevant sensor capabilities and challenges related to communication and navigation. This paper also presents experiences from a field campaign that took place in Ny-Aalesund at Svalbard in January 2014, where a REMUS 100 AUV was used for sea-floor mapping and collection of oceanographic parameters. Based on this, we discuss the experiences related to using AUVs for ice-monitoring. We conclude that AUVs are highly applicable for ice-monitoring, but further research is needed.

  18. Three-Dimensional Passive Source Localisation using the Flank Array of an Autonomous Underwater Vehicle in Shallow Water

    Directory of Open Access Journals (Sweden)

    Dexin Zhao

    2013-05-01

    Full Text Available Researchers have become interested in autonomous underwater vehicles equipped with various kinds of sonar systems that can perform many of underwater tasks, which is encouraged by the potential benefits of cost reduction and flexible deployment. This paper proposes an approach to three-dimensional passive source localisation with the flank array of an autonomous underwater vehicle in shallow water. The approach is developed based on matched-field processing for the likelihood of passive source localisation in the shallow water environment. Inter-position processing is also used for the improved localisation performance and the enhanced stability of the estimation process against the lack of spatial gain due to the small physical size of the flank array. The proposed approach is presented and validated through simulation and experimental data. The results illustrate the localisation performance at different signal-to-noise ratios and demonstrate the build up over time of the positional parameters of the estimated source as the autonomous underwater vehicle cruises at a low speed along a straight line at a constant depth.

  19. Three-Dimensional Passive Source Localisation using the Flank Array of an Autonomous Underwater Vehicle in Shallow Water

    Directory of Open Access Journals (Sweden)

    Dexin Zhao

    2013-05-01

    Full Text Available Researchers have become interested in autonomous underwater vehicles equipped with various kinds of sonar systems that can perform many of underwater tasks, which is encouraged by the potential benefits of cost reduction and flexible deployment. This paper proposes an approach to three-dimensional passive source localisation with the flank array of an autonomous underwater vehicle in shallow water. The approach is developed based on matched-field processing for the likelihood of passive source localisation in the shallow water environment. Inter-position processing is also used for the improved localisation performance and the enhanced stability of the estimation process against the lack of spatial gain due to the small physical size of the flank array. The proposed approach is presented and validated through simulation and experimental data. The results illustrate the localisation performance at different signal-to-noise ratios and demonstrate the build up over time of the positional parameters of the estimated source as the autonomous underwater vehicle cruises at a low speed along a straight line at a constant depth.Defence Science Journal, 2013, 63(3, pp.323-330, DOI:http://dx.doi.org/10.14429/dsj.63.3011

  20. Three-Dimensional Path Planning Method for Autonomous Underwater Vehicle Based on Modified Firefly Algorithm

    Directory of Open Access Journals (Sweden)

    Chang Liu

    2015-01-01

    Full Text Available Path planning is a classic optimization problem which can be solved by many optimization algorithms. The complexity of three-dimensional (3D path planning for autonomous underwater vehicles (AUVs requires the optimization algorithm to have a quick convergence speed. This work provides a new 3D path planning method for AUV using a modified firefly algorithm. In order to solve the problem of slow convergence of the basic firefly algorithm, an improved method was proposed. In the modified firefly algorithm, the parameters of the algorithm and the random movement steps can be adjusted according to the operating process. At the same time, an autonomous flight strategy is introduced to avoid instances of invalid flight. An excluding operator was used to improve the effect of obstacle avoidance, and a contracting operator was used to enhance the convergence speed and the smoothness of the path. The performance of the modified firefly algorithm and the effectiveness of the 3D path planning method were proved through a varied set of experiments.

  1. Second Order Sliding Mode Control Scheme for an Autonomous Underwater Vehicle with Dynamic Region Concept

    Directory of Open Access Journals (Sweden)

    Zool H. Ismail

    2015-01-01

    Full Text Available The main goal in developing closed loop control system for an Autonomous Underwater Vehicle (AUV is to make a robust vehicle from natural and exogenous perturbations such as wind, wave, and ocean currents. However a well-known robust control, for instance, Sliding Mode Controller (SMC, gives a chattering effect and it influences the stability of an AUV. Furthermore, some researchers combined other controls to get better result but it tends to present long computational time and causes large energy consumption. Thus, this paper proposed a Super Twisting Sliding Mode Controller (STSMC with dynamic region concept for an AUV. STSMC or a second order SMC is adopted as a robust controller which is free from chattering effect. Meanwhile, the implementation of dynamic region is useful to reduce the energy usage. As a result, the proposed controller obtains global asymptotic stability which is validated by using Lyapunov-like function. Moreover, some simulations present the efficiency of proposed controller. In conclusion, STSMC with region based control is effective to be applied for the robust tracking of an AUV. It contributes to give a fast response when handling the perturbations, short computational time, and low energy demand.

  2. Mapping and initial dilution estimation of an ocean outfall plume using an autonomous underwater vehicle

    Science.gov (United States)

    Ramos, P. A.; Neves, M. V.; Pereira, F. L.

    2007-03-01

    A monitoring mission to study the shape and estimate initial dilution of the S. Jacinto outfall plume using an autonomous underwater vehicle (AUV) was performed on July 30, 2002. In order to reduce the uncertainty about plume location and to concentrate the vehicle mission only in the hydrodynamic mixing zone, outputs of a near-field prediction model, based on effective real-time in situ measurements of current speed and direction and density stratification, were opportunistically used to specify in real time the mission transects. The surface characteristics of the outfall plume were found to be influenced strongly by the relatively weak stratification and low current velocities. Dilution was estimated using a temperature-salinity ( TS-) diagram with initial mixing lines between wastewater and ambient waters. Effluent dilutions were at least 30:1 in this study. In order to efficiently map the plume dispersion we applied the least-squares collocation method technique. Our results demonstrate that AUVs can provide high-quality measurements of physical properties of effluent plumes in a quite effective manner and valuable considerations about the initial mixing processes under real oceanic conditions can be further investigated.

  3. Vision-Based Autonomous Underwater Vehicle Navigation in Poor Visibility Conditions Using a Model-Free Robust Control

    Directory of Open Access Journals (Sweden)

    Ricardo Pérez-Alcocer

    2016-01-01

    Full Text Available This paper presents a vision-based navigation system for an autonomous underwater vehicle in semistructured environments with poor visibility. In terrestrial and aerial applications, the use of visual systems mounted in robotic platforms as a control sensor feedback is commonplace. However, robotic vision-based tasks for underwater applications are still not widely considered as the images captured in this type of environments tend to be blurred and/or color depleted. To tackle this problem, we have adapted the lαβ color space to identify features of interest in underwater images even in extreme visibility conditions. To guarantee the stability of the vehicle at all times, a model-free robust control is used. We have validated the performance of our visual navigation system in real environments showing the feasibility of our approach.

  4. IEEE AUV 96 / Oceanic Engineering Society Institute of Electrical and Electronics Engineers Symposium on Autonomous Underwater Vehicle (AUV) Technology / June 2 -6, 1996 in Monterey, California

    OpenAIRE

    1996-01-01

    Oceanic Engineering Society Institute of Electrical and Electronics Engineers (IEEE) Symposium On Autonomous Underwater Vehicle (AUV) Technology June 2-6, 1996 Advance Program Hosted by the Naval Postgraduate School at the Hyatt Regency Hotel, Monterey California USA General Information, registration information, conference proceedings, accomodations, etc. on the IEEE AUV 96 Symposium on Autonomous Underwater Vehicle (AUV) Technology, June 2 - 6, 1996 Hosted by the Nav...

  5. Design of the simulator of the motion of the unmanned autonomous underwater vehicle as a component of the simulation complex

    OpenAIRE

    Sirivchuk, Andriy S.

    2015-01-01

    The study of the automatic control system for the autonomous underwater vehicle is a complex and expensive process. Conducting experiments in test pools and open water may cause damage to expensive equipment. Therefore, the use of simulation complexes is a more efficient approach. The article aim is to describe the structure of the simulation complex designed for the study of the quality of the automatic control system. The main component of this complex is the simulator of the motion of the ...

  6. Design and Implementation of a Biomimetic Turtle Hydrofoil for an Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Jordi Palacin

    2011-11-01

    Full Text Available This paper presents the design and implementation of a turtle hydrofoil for an Autonomous Underwater Vehicle (AUV. The final design of the AUV must have navigation performance like a turtle, which has also been the biomimetic inspiration for the design of the hydrofoil and propulsion system. The hydrofoil design is based on a National Advisory Committee for Aeronautics (NACA 0014 hydrodynamic profile. During the design stage, four different propulsion systems were compared in terms of propulsion path, compactness, sealing and required power. The final implementation is based on a ball-and-socket mechanism because it is very compact and provides three degrees of freedom (DoF to the hydrofoil with very few restrictions on the propulsion path. The propulsion obtained with the final implementation of the hydrofoil has been empirically evaluated in a water channel comparing different motion strategies. The results obtained have confirmed that the proposed turtle hydrofoil controlled with a mechanism with three DoF generates can be used in the future implementation of the planned AUV.

  7. High resolution study of the spatial distributions of abyssal fishes by autonomous underwater vehicle.

    Science.gov (United States)

    Milligan, R J; Morris, K J; Bett, B J; Durden, J M; Jones, D O B; Robert, K; Ruhl, H A; Bailey, D M

    2016-01-01

    On abyssal plains, demersal fish are believed to play an important role in transferring energy across the seafloor and between the pelagic and benthic realms. However, little is known about their spatial distributions, making it difficult to quantify their ecological significance. To address this, we employed an autonomous underwater vehicle to conduct an exceptionally large photographic survey of fish distributions on the Porcupine Abyssal Plain (NE Atlantic, 4850 m water depth) encompassing two spatial scales (1-10 km(2)) on and adjacent to a small abyssal hill (240 m elevation). The spatial distributions of the total fish fauna and that of the two dominant morphotypes (Coryphaenoides sp. 1 and C. profundicolus) appeared to be random, a result contrary to common expectation but consistent with previous predictions for these fishes. We estimated total fish density on the abyssal plain to be 723 individuals km(-2) (95% CI: 601-844). This estimate is higher, and likely more precise, than prior estimates from trawl catch and baited camera techniques (152 and 188 individuals km(-2) respectively). We detected no significant difference in fish density between abyssal hill and plain, nor did we detect any evidence for the existence of fish aggregations at any spatial scale assessed. PMID:27180728

  8. Analysis of Parameter Sensitivity Using Robust Design Techniques for a Flatfish Type Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    M. Santhakumar

    2009-01-01

    Full Text Available Hydrodynamic parameters play a major role in the dynamics and control of Autonomous Underwater Vehicles (AUVs. The performance of an AUV is dependent on the parameter variations and a proper understanding of these parametric influences is essential for the design, modeling, and control of high-performance AUVs. In this paper, the sensitivity of hydrodynamic parameters on the control of a flatfish type AUV is analyzed using robust design techniques such as Taguchi's design method and statistical analysis tools such as Pareto-ANOVA. Since the pitch angle of an AUV is one of the crucial variables in the control applications, the sensitivity analysis of pitch angle variation is studied here. Eight prominent hydrodynamic coefficients are considered in the analysis. The results show that there are two critical hydrodynamic parameters, that is, hydrodynamic force and hydrodynamic pitching moment in the heave direction that influence the performance of a flatfish type AUV. A near-optimal combination of the parameters was identified and the simulation results have shown the effectiveness of the method in reducing the pitch error. These findings are significant for the design modifications as well as controller design of AUVs.

  9. An apparatus to estimate the hydrodynamic coefficients of autonomous underwater vehicles using water tunnel testing

    Science.gov (United States)

    Nouri, N. M.; Mostafapour, K.; Bahadori, R.

    2016-06-01

    Hydrodynamic coefficients or hydrodynamic derivatives of autonomous underwater vehicles (AUVs) play an important role in their development and maneuverability. The most popular way of estimating their coefficients is to implement captive model tests such as straight line tests and planar motion mechanism (PMM) tests in the towing tanks. This paper aims to develop an apparatus based on planar experiments of water tunnel in order to estimate hydrodynamic derivatives due to AUVs' acceleration and velocity. The capability of implementing straight line tests and PMM ones using mechanical oscillators located in the downstream flow of the model is considered in the design procedure of the system. The hydrodynamic derivatives that resulted from the acceleration and velocity of the AUV model were estimated using the apparatus that we developed. Static and dynamics test results were compared for the similar derivatives. The findings showed that the system provided the basis for conducting static tests, i.e., straight-line and dynamic tests that included pure pitch and pure heave. By conducting such tests in a water tunnel, we were able to eliminate errors related to the time limitation of the tests and the effects of surface waves in the towing tank on AUVs with applications in the deep sea.

  10. High resolution study of the spatial distributions of abyssal fishes by autonomous underwater vehicle

    Science.gov (United States)

    Milligan, R. J.; Morris, K. J.; Bett, B. J.; Durden, J. M.; Jones, D. O. B.; Robert, K.; Ruhl, H. A.; Bailey, D. M.

    2016-05-01

    On abyssal plains, demersal fish are believed to play an important role in transferring energy across the seafloor and between the pelagic and benthic realms. However, little is known about their spatial distributions, making it difficult to quantify their ecological significance. To address this, we employed an autonomous underwater vehicle to conduct an exceptionally large photographic survey of fish distributions on the Porcupine Abyssal Plain (NE Atlantic, 4850 m water depth) encompassing two spatial scales (1–10 km2) on and adjacent to a small abyssal hill (240 m elevation). The spatial distributions of the total fish fauna and that of the two dominant morphotypes (Coryphaenoides sp. 1 and C. profundicolus) appeared to be random, a result contrary to common expectation but consistent with previous predictions for these fishes. We estimated total fish density on the abyssal plain to be 723 individuals km‑2 (95% CI: 601–844). This estimate is higher, and likely more precise, than prior estimates from trawl catch and baited camera techniques (152 and 188 individuals km‑2 respectively). We detected no significant difference in fish density between abyssal hill and plain, nor did we detect any evidence for the existence of fish aggregations at any spatial scale assessed.

  11. Design and implementation of a biomimetic turtle hydrofoil for an autonomous underwater vehicle.

    Science.gov (United States)

    Font, Davinia; Tresanchez, Marcel; Siegentahler, Cedric; Pallejà, Tomàs; Teixidó, Mercè; Pradalier, Cedric; Palacin, Jordi

    2011-01-01

    This paper presents the design and implementation of a turtle hydrofoil for an Autonomous Underwater Vehicle (AUV). The final design of the AUV must have navigation performance like a turtle, which has also been the biomimetic inspiration for the design of the hydrofoil and propulsion system. The hydrofoil design is based on a National Advisory Committee for Aeronautics (NACA) 0014 hydrodynamic profile. During the design stage, four different propulsion systems were compared in terms of propulsion path, compactness, sealing and required power. The final implementation is based on a ball-and-socket mechanism because it is very compact and provides three degrees of freedom (DoF) to the hydrofoil with very few restrictions on the propulsion path. The propulsion obtained with the final implementation of the hydrofoil has been empirically evaluated in a water channel comparing different motion strategies. The results obtained have confirmed that the proposed turtle hydrofoil controlled with a mechanism with three DoF generates can be used in the future implementation of the planned AUV. PMID:22247660

  12. Oscillatory Adaptive Yaw-Plane Control of Biorobotic Autonomous Underwater Vehicles Using Pectoral-Like Fins

    Directory of Open Access Journals (Sweden)

    Mugdha S. Naik

    2007-01-01

    Full Text Available This article considers the control of a biorobotic autonomous underwater vehicle (BAUV in the yaw plane using biologically inspired oscillatory pectoral-like fins of marine animals. The fins are assumed to be oscillating harmonically with a combined linear (sway and angular (yaw motion producing unsteady forces, which are used for fish-like control of BAUVs. Manoeuvring of the BAUV in the yaw plane is accomplished by altering the bias (mean angle of the angular motion of the fin. For the derivation of the adaptive control system, it is assumed that the physical parameters, the hydrodynamic coefficients, and the fin force and moment are not known. A direct adaptive sampled-data control system for the trajectory control of the yaw-angle using only yaw-angle measurement is derived. The parameter adaptation law is based on the normalised gradient scheme. Simulation results for the set point control, sinusoidal trajectory tracking and turning manoeuvres are presented, which show that the control system accomplishes precise trajectory control in spite of the parameter uncertainties.

  13. Infrastructure for thulium-170 isotope power systems for autonomous underwater vehicle fleets

    International Nuclear Information System (INIS)

    The radioisotope thulium-170 is a safe and environmentally benign heat source for providing the high endurance and energy densities needed by advanced power systems for autonomous underwater vehicles (AUV). Thulium Isotope Power (TIP) systems have an endurance of ∼3000 h, and gravimetric and volumetric energy densities of 3 x 104 Wh/kg and 3 x 108 Wh/m3, respectively. These energy densities are more than 200 times higher than those currently provided by Ag-Zn battery technology. In order to capitalize on these performance levels with about one hundred AUVs in continuous use, it will be necessary to establish an infrastructure for isotope production and heat-source refurbishment. The infrastructure cost is not trivial, and studies are needed to determine its optimum configuration. The major component of the projected infrastructure is the nuclear reactor used to produce Tm- 170 by neutron absorption in Tm-169. The reactor design should ideally be optimized for TM-170 production. Using the byproduct ''waste'' heat beneficially would help defray the cost of isotope production. However, generating electric power with the reactor would compromise both the cost of electricity and the isotope production capacity. A coastal location for the reactor would be most convenient from end-use considerations, and the ''waste'' heat could be used to desalinate seawater in water-thirsty states. 13 refs., 6 figs., 2 tabs

  14. Localization and Tracking of Submerged Phytoplankton Bloom Patches by an Autonomous Underwater Vehicle

    Science.gov (United States)

    Godin, M. A.; Ryan, J. P.; Zhang, Y.; Bellingham, J. G.

    2012-12-01

    Observing plankton in their drifting frame of reference permits effective studies of marine ecology from the perspective of microscopic life itself. By minimizing variation caused simply by advection, observations in a plankton-tracking frame of reference focus measurement capabilities on the processes that influence the life history of populations. Further, the patchy nature of plankton populations motivates use of sensor data in real-time to resolve patch boundaries and adapt observing resources accordingly. We have developed capabilities for population-centric plankton observation and sampling by autonomous underwater vehicles (AUVs). Our focus has been on phytoplankton populations, both because of their ecological significance - as the core of the oceanic food web and yet potentially harmful under certain bloom conditions, as well as the accessibility of their signal to simple optical sensing. During the first field deployment of these capabilities in 2010, we tracked a phytoplankton patch containing toxigenic diatoms and found that their toxicity correlated with exposure to resuspended sediments. However, this first deployment was labor intensive as the AUV drove in a pre-programmed pattern centered around a patch-marking drifter; it required a boat deployment of the patch-marking drifter and required full-time operators to periodically estimate of the position of the patch with respect to the drifter and adjust the AUV path accordingly. In subsequent field experiments during 2011 and 2012, the Tethys-class long-range AUVs ran fully autonomous patch tracking algorithms which detected phytoplankton patches and continually updated estimates of each patch center by driving adaptive patterns through the patch. Iterations of the algorithm were generated to overcome the challenges of tracking advecting and evolving patches while minimizing human involvement in vehicle control. Such fully autonomous monitoring will be necessary to perform long-term in

  15. Optimization of S-surface controller for autonomous underwater vehicle with immune-genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    LI Ye; ZHANG Lei; WAN Lei; LIANG Xiao

    2008-01-01

    To deduce error and fussy work of manual adjustment of parameters for an S-surface controller in underwater vehicle motion control, the immune-genetic optimization of S-surface controller of an underwater vehicle was proposed. The ability of producing various antibodies for the immune algorithm, the self-adjustment of antibody density, and the antigen immune memory were used to realize the rapid convergence of S-surface controller parameters. It avoided loitering near the local peak value. Deduction of the S-surface controller was given. General process of the immune-genetic algorithm was described and immune-genetic optimization of S-surface controller parameters was discussed. Definitive results were obtained from many simulation experiments and lake experiments, which indicate that the algorithm can get good effect in optimizing the nonlinear motion controller parameters of an underwater vehicle.

  16. Integral sliding mode controller for precise manoeuvring of autonomous underwater vehicle in the presence of unknown environmental disturbances

    Science.gov (United States)

    Kim, Minsung; Joe, Hangil; Kim, Jinwhan; Yu, Son-cheol

    2015-10-01

    We propose an integral sliding mode controller (ISMC) to stabilse an autonomous underwater vehicle (AUV) which is subject to modelling errors and often suffers from unknown environmental disturbances. The ISMC is effective in compensating for the uncertainties in the hydrodynamic and hydrostatic parameters of the vehicle and rejecting the unpredictable disturbance effects due to ocean waves, tides and currents. The ISMC is comprised of an equivalent controller and a switching controller to suppress the parameter uncertainties and external disturbances, and its closed-loop system is exponentially stable. Numerical simulations were performed to validate the proposed control approach, and experimental tests using Cyclops AUV were carried out to demonstrate its practical feasibility.

  17. TRIDENT: A Framework for Autonomous Underwater Intervention

    OpenAIRE

    Sanz Valero, Pedro José; Ridao, Pere; Oliver, Gabriel; Melchiorri, Claudio; Casalino, Giuseppe; Silvestre, Carlos; Petillot, Yvan; Turetta, Alessio

    2011-01-01

    TRIDENT is a STREP project recently approved by the European Commission whose proposal was submitted to the ICT call 4 of the 7th Framework Program. The project proposes a new methodology for multipurpose underwater intervention tasks. To that end, a cooperative team formed with an Autonomous Surface Craft and an Intervention Autonomous Underwater Vehicle will be used. The proposed methodology splits the mission in two stages mainly devoted to survey and intervention tasks, res...

  18. The Sentry Autonomous Underwater Vehicle: Field Trial Results and Future Capabilities

    Science.gov (United States)

    Yoerger, D. R.; Bradley, A. M.; Martin, S. C.; Whitcomb, L. L.

    2006-12-01

    The Sentry autonomous underwater vehicle combines an efficient long range survey capability with the ability to maneuver at low speeds. These attributes will permit Sentry to perform a variety of conventional and unconventional surveys including long range sonar surveys, hydrothermal plume surveys and near-bottom photo surveys. Sentry's streamlined body and fore and aft tilting planes, each possessing an independently controlled thruster, enable efficient operation in both near-bottom and cruising operations. Sentry is capable of being configured in two modes: hover mode, which commands Sentry's control surfaces to be aligned vertically, and forward flight mode, which allows Sentry's control surfaces to actuate between plus or minus 45 degrees. Sentry is equipped for full 6-Degrees of freedom position measurement. Vehicle heading, roll, and pitch are instrumented with a TCM2 PNI heading and attitude sensor. A Systron Donner yaw rate sensor instrumented heading rate. Depth is instrumented by a Paroscientific depth sensor. A 300kHz RD Instruments Doppler Sonar provides altitude and XYZ velocity measurements. In April 2006, we conducted our first deep water field trials of Sentry in Bermuda. These trials enabled us to examine a variety of issues, including the control software, vehicle safety systems, launch and recovery procedures, operation at depth, heading and depth controllers over a range of speeds, and power consumption. Sentry employ's a control system based upon the Jason 2 control system for low-level control, which has proven effective and reliable over several hundred deep-water dives. The Jason 2 control system, developed jointly at Johns Hopkins University and Woods Hole Oceanographic Institution, was augmented to manage Sentry-specific devices (sensors, actuators, and power storage) and to employ a high-level mission controller that supported autonomous mission scripting and error detection and response. This control suite will also support the Nereus

  19. Autonomous underwater pipeline monitoring navigation system

    Science.gov (United States)

    Mitchell, Byrel; Mahmoudian, Nina; Meadows, Guy

    2014-06-01

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

  20. Subsurface observations of white shark Carcharodon carcharias predatory behaviour using an autonomous underwater vehicle.

    Science.gov (United States)

    Skomal, G B; Hoyos-Padilla, E M; Kukulya, A; Stokey, R

    2015-12-01

    In this study, an autonomous underwater vehicle (AUV) was used to test this technology as a viable tool for directly observing the behaviour of marine animals and to investigate the behaviour, habitat use and feeding ecology of white sharks Carcharodon carcharias near Guadalupe Island off the coast of Mexico. During the period 31 October to 7 November 2013, six AUV missions were conducted to track one male and three female C. carcharias, ranging in estimated total length (LT ) from 3·9 to 5·7 m, off the north-east coast of Guadalupe Island. In doing so, the AUV generated over 13 h of behavioural data for C. carcharias at depths down to 90 m. The sharks remained in the area for the duration of each mission and moved through broad depth and temperature ranges from the surface to 163·8 m depth (mean ± S.D. = 112·5 ± 40·3 m) and 7·9-27·1° C (mean ± S.D. = 12·7 ± 2·9° C), respectively. Video footage and AUV sensor data revealed that two of the C. carcharias being tracked and eight other C. carcharias in the area approached (n = 17), bumped (n = 4) and bit (n = 9) the AUV during these tracks. This study demonstrated that an AUV can be used to effectively track and observe the behaviour of a large pelagic animal, C. carcharias. In doing so, the first observations of subsurface predatory behaviour were generated for this species. At its current state of development, this technology clearly offers a new and innovative tool for tracking the fine-scale behaviour of marine animals. PMID:26709209

  1. Autonomous underwater riser inspection tool

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  2. Lightweight Autonomous Underwater Vehicles (AUVs) performing coastal survey operations in REP 10A

    Science.gov (United States)

    Incze, Michael L.

    2011-11-01

    Lightweight Autonomous Underwater Vehicles (AUVs) were developed for Naval Special Warfare (NSW) Group 4 search and survey missions from a commercial AUV baseline (Iver 2) through integration of commercial off-the-shelf (COTS) hardware components, and through software development for enhanced on-board Command and Control functions. The development period was 1 year under a project sponsored by the Office of Naval Research TechSolutions Program Office. Hardware integration was completed by the commercial AUV vendor, OceanServer Technology, Inc., and software development was conducted by the Naval Undersea Warfare Center, Naval Oceanographic Office, and U MASS Dartmouth, with support from hardware and software application providers (YSI, Inc., Imagenex Technology Corp., and CARIS). At the conclusion of the integration and development period, an at-sea performance evaluation was scheduled for the Lightweight NSW AUVs with NSWG-4 personnel. The venue for this evaluation was the NATO exercise Recognized Environmental Picture 10A (REP 10A), hosted by Marinha Portuguesa, and coordinated by the Faculdade de Engenharia-Universidade do Porto. REP 10A offered an opportunity to evaluate the performance of the new AUVs and to explore the Concept of Operations (CONOPS) for employing them in military survey operations in shallow coastal waters. Shore- and ship-launched scenarios with launch/recovery by a single operator in a one-to-many coordinated survey, on-scene data product generation and visualization, data push to Reach Back Cells for product integration and enhancement, and survey optimization to streamline survey effort and timelines were included in the CONOPS review. Opportunities to explore employment of hybrid AUV fleets in Combined Force scenarios were also utilized. The Naval Undersea Warfare Center, Marinha Portuguesa, the Faculdade de Engenharia-Universidade do Porto, and OceanServer Technology, Inc., were the primary participants bringing in-water resources to

  3. AUV自主导航航位推算算法的研究%Dead Reckoning Method for Autonomous Navigation of Autonomous Underwater Vehicles

    Institute of Scientific and Technical Information of China (English)

    冯子龙; 刘健; 刘开周

    2005-01-01

    对AUV (Autonomous Underwater Vehicle)自主导航的航位推算算法做了进一步研究并加以改进,以提高其自主导航精度.然后,利用AUV湖试所获得的数据,对本文提出的修正算法进行了验证.结果表明, AUV的自主导航精度得到很大提高,可以用于修正原来的自主导航算法.

  4. Dynamics modeling of a semi-submersible autonomous underwater vehicle with a towfish towed by a cable

    Directory of Open Access Journals (Sweden)

    Park Jinmo

    2015-06-01

    Full Text Available In this paper, we employ a dynamics modeling method for investigating a multi-body dynamics system of semi-submersible autonomous underwater vehicles consisting of a towing vehicle operated near the water surface, a tow cable, and a towfish. The towfish, which is towed by a marine cable for the purposes of exploration or mine hunting, is modeled with a Six-Degree-of-Freedom (6-DOF equation of motion that reflects its hydrodynamics characteristics. The towing cable, which can experience large displacements and deformations, is modeled using an absolute nodal coordinate formulation. To reflect the hydrodynamic characteristics of the cable during motion, the hydrodynamic force due to added mass and the drag force are imposed. To verify the completeness of the modeling, a few simple numerical simulations were conducted, and the results confirm the physical plausibility of the model.

  5. Dynamics modeling of a semi-submersible autonomous underwater vehicle with a towfish towed by a cable

    Science.gov (United States)

    Park, Jinmo; Kim, Nakwan

    2015-06-01

    In this paper, we employ a dynamics modeling method for investigating a multi-body dynamics system of semi-submersible autonomous underwater vehicles consisting of a towing vehicle operated near the water surface, a tow cable, and a towfish. The towfish, which is towed by a marine cable for the purposes of exploration or mine hunting, is modeled with a Six-Degree-of-Freedom (6-DOF) equation of motion that reflects its hydrodynamics characteristics. The towing cable, which can experience large displacements and deformations, is modeled using an absolute nodal coordinate formulation. To reflect the hydrodynamic characteristics of the cable during motion, the hydrodynamic force due to added mass and the drag force are imposed. To verify the completeness of the modeling, a few simple numerical simulations were conducted, and the results confirm the physical plausibility of the model.

  6. Application of GA, PSO, and ACO Algorithms to Path Planning of Autonomous Underwater Vehicles

    Institute of Scientific and Technical Information of China (English)

    Mohammad Pourmahmood Aghababa; Mohammad Hossein Amrollahi; Mehdi Borjkhani

    2012-01-01

    In this paper,an underwater vehicle was modeled with six dimensional nonlinear equations of motion,controlled by DC motors in all degrees of freedom.Near-optimal trajectories in an energetic environment for underwater vehicles were computed using a numerical solution of a nonlinear optimal control problem (NOCP).An energy performance index as a cost function,which should be minimized,was defined.The resulting problem was a two-point boundary value problem (TPBVP).A genetic algorithm (GA),particle swarm optimization (PSO),and ant colony optimization (ACO) algorithms were applied to solve the resulting TPBVP.Applying an Euler-Lagrange equation to the NOCE a conjugate gradient penalty method was also adopted to solve the TPBVP.The problem of energetic environments,involving some energy sources,was discussed.Some near-optimal paths were found using a GA,PSO,and ACO algorithms.Finally,the problem of collision avoidance in an energetic environment was also taken into account.

  7. Parallel Neural Network-Based Motion Controller for Autonomous Underwater Vehicles

    Institute of Scientific and Technical Information of China (English)

    GAN Yong; WANG Li-rong; WAN Lei; XU Yu-ru

    2005-01-01

    A parallel neural network-based controller (PNNC) is presented for the motion control of underwater vehicles in this paper. It consists of a real-time part, a self-learning part and a desired-state programmer, and it is different from normal adaptive neural network controller in structure. Owing to the introduction of the self-learning part, on-line learning can be performed without sample data in several sample periods, resulting in high learning speed of the controller and good control performance. The desired-state programmer is utilized to obtain better learning samples of the neural network to keep the stability of the controller. The developed controller is applied to the 4-degree of freedom control of the AUV "IUV-IV" and is successful on the simulation platform. The control performance is also compared with that of neural network controller with different structures such as normal adaptive neural network and different learning methods. Current effects and surge velocity control are also included to demonstrate the controller's performance. It is shown that the PNNC has a great possibility to solve the problems in the control system design of underwater vehicles.

  8. An Obstacle Recognizing Mechanism for Autonomous Underwater Vehicles Powered by Fuzzy Domain Ontology and Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Zhen-Shu Mi

    2014-01-01

    Full Text Available The autonomous underwater vehicle (AUV and the problems associated with its safe navigation have been studied for the last two decades. The real-time underwater obstacle recognition procedure still has many complications associated with it and the issue becomes worse with vague sensor data. These problems can be coped with the merger of a robust classification mechanism and a domain knowledge acquisition technique. In this paper, we introduce a hybrid mechanism to recognize underwater obstacles for AUV based on fuzzy domain ontology and support vector machine (SVM. SVM is an efficient algorithm that was developed for recognizing 3D object in recent years and is a new generation learning system based on recent advances in statistical learning theory. The amalgamation of fuzzy domain ontology with SVM boosts the performance of the obstacle recognition module by providing the timely semantic domain information of the surrounding circumstances. Also the reasoning ability of the fuzzy domain ontology can expedite the obstacle avoidance process. In order to evaluate the performance of the system, we developed a prototype simulator based on OpenGL and VC++. We compared the outcomes of our proposed technique with backpropagation algorithm and classic SVM based techniques.

  9. Fish and chips: implementation of a neural network model into computer chips to maximize swimming efficiency in autonomous underwater vehicles.

    Science.gov (United States)

    Blake, R W; Ng, H; Chan, K H S; Li, J

    2008-09-01

    Recent developments in the design and propulsion of biomimetic autonomous underwater vehicles (AUVs) have focused on boxfish as models (e.g. Deng and Avadhanula 2005 Biomimetic micro underwater vehicle with oscillating fin propulsion: system design and force measurement Proc. 2005 IEEE Int. Conf. Robot. Auto. (Barcelona, Spain) pp 3312-7). Whilst such vehicles have many potential advantages in operating in complex environments (e.g. high manoeuvrability and stability), limited battery life and payload capacity are likely functional disadvantages. Boxfish employ undulatory median and paired fins during routine swimming which are characterized by high hydromechanical Froude efficiencies (approximately 0.9) at low forward speeds. Current boxfish-inspired vehicles are propelled by a low aspect ratio, 'plate-like' caudal fin (ostraciiform tail) which can be shown to operate at a relatively low maximum Froude efficiency (approximately 0.5) and is mainly employed as a rudder for steering and in rapid swimming bouts (e.g. escape responses). Given this and the fact that bioinspired engineering designs are not obligated to wholly duplicate a biological model, computer chips were developed using a multilayer perception neural network model of undulatory fin propulsion in the knifefish Xenomystus nigri that would potentially allow an AUV to achieve high optimum values of propulsive efficiency at any given forward velocity, giving a minimum energy drain on the battery. We envisage that externally monitored information on flow velocity (sensory system) would be conveyed to the chips residing in the vehicle's control unit, which in turn would signal the locomotor unit to adopt kinematics (e.g. fin frequency, amplitude) associated with optimal propulsion efficiency. Power savings could protract vehicle operational life and/or provide more power to other functions (e.g. communications). PMID:18626130

  10. Coordinate control of initiative mating device for autonomous underwater vehicle based on TDES

    Institute of Scientific and Technical Information of China (English)

    YAN Zhe-ping; HOU Shu-ping

    2005-01-01

    A novel initiative mating device, which has four 2-degree manipulators around the mating skirt, is proposed to mate between a skirt of AUV (autonomons underwater vehicle) and a disabled submarine. The primary function of the device is to keep exact mating between skirt and disabled submarine in a badly sub sea environment. According to the characteristic of rescue, an automaton model is brought forward to describe the mating proceed between AUV and manipulators. The coordinated control is implemented by the TDES(time discrete event system).After taking into account the time problem, it is a useful method to control mating by simulation testing. The result shows that it reduces about 70 seconds after using intelligent co-ordinate control based on TDES through the whole mating procedure.

  11. H2-O2 fuel cell and advanced battery power systems for autonomous underwater vehicles: performance envelope comparisons

    International Nuclear Information System (INIS)

    Autonomous underwater vehicles have traditionally been powered by low energy density lead-acid batteries. Recently, advanced battery technologies and H2-O2 fuel cells have become available, offering significant improvements in performance. This paper compares the solid polymer fuel cell to the lithium-thionyl chloride primary battery, sodium-sulfur battery, and lead acid battery for a variety of missions. The power system performance is simulated using computer modelling techniques. Performance envelopes are constructed, indicating domains of preference for competing power system technologies. For most mission scenarios, the solid polymer fuel cell using liquid reactant storage is the preferred system. Nevertheless, the advanced battery systems are competitive with the fuel cell systems using gaseous hydrogen storage, and they illustrate preferred performance for missions requiring high power density. 11 figs., 4 tabs., 15 refs

  12. Robust Huber-based iterated divided difference filtering with application to cooperative localization of autonomous underwater vehicles.

    Science.gov (United States)

    Gao, Wei; Liu, Yalong; Xu, Bo

    2014-01-01

    A new algorithm called Huber-based iterated divided difference filtering (HIDDF) is derived and applied to cooperative localization of autonomous underwater vehicles (AUVs) supported by a single surface leader. The position states are estimated using acoustic range measurements relative to the leader, in which some disadvantages such as weak observability, large initial error and contaminated measurements with outliers are inherent. By integrating both merits of iterated divided difference filtering (IDDF) and Huber's M-estimation methodology, the new filtering method could not only achieve more accurate estimation and faster convergence contrast to standard divided difference filtering (DDF) in conditions of weak observability and large initial error, but also exhibit robustness with respect to outlier measurements, for which the standard IDDF would exhibit severe degradation in estimation accuracy. The correctness as well as validity of the algorithm is demonstrated through experiment results. PMID:25536004

  13. A Self-Tuning Proportional-Integral-Derivative Controller for an Autonomous Underwater Vehicle, Based On Taguchi Method

    Directory of Open Access Journals (Sweden)

    M, Santhakumar

    2010-01-01

    Full Text Available Problem statement: Conventional Proportional-Integral-Derivative (PID controllers exhibit moderately good performance once the PID gains are properly tuned. However, when the dynamic characteristics of the system are time dependent or the operating conditions of the system vary, it is necessary to retune the gains to obtain desired performance. This situation has renewed the interest of researchers and practitioners in PID control. Self-tuning of PID controllers has emerged as a new and active area of research with the advent and easy availability of algorithms and computers. This study discusses self-tuning (auto-tuning algorithm for control of autonomous underwater vehicles. Approach: Self-tuning mechanism will avoid time consuming manual tuning of controllers and promises better results by providing optimal PID controller settings as the system dynamics or operating points change. Most of the self-tuning methods available in the literature were based on frequency response characteristics and search methods. In this study, we proposed a method based on Taguchi’s robust design method for self-tuning of an autonomous underwater vehicle controller. The algorithm, based on this method, tuned the controller gains optimally and robustly in real time with less computation effort by using desired and actual state variables. It can be used for the Single-Input Single-Output (SISO systems as well as Multi-Input Multi-Output (MIMO systems without mathematical models of plants. Results: A simulation study of the AUV control on the horizontal plane (yaw plane control was used to demonstrate and validate the performance and effectiveness of the proposed scheme. Simulation results of the proposed self-tuning scheme are compared with the conventional PID controllers which are tuned by Ziegler-Nichols (ZN and Taguchi’s tuning methods. These results showed that the Integral Square Error (ISE is significantly reduced from the conventional

  14. Development of A Three-Dimensional Guidance System for Long-Range Maneuvering of A Miniature Autonomous Underwater Vehicle

    Institute of Scientific and Technical Information of China (English)

    Mansour ATAEI; Aghil YOUSEFI-KOMA

    2014-01-01

    The present paper introduces a three-dimensional guidance system developed for a miniature Autonomous Underwater Vehicle (AUV). The guidance system determines the best trajectory for the vehicle based on target behavior and vehicle capabilities. The dynamic model of this novel AUV is derived based on its special characteristics such as the horizontal posture and the independent diving mechanism. To design the guidance strategy, the main idea is to select the desired depth, presumed proportional to the horizontal distance of the AUV and the target. By connecting the two with a straight line, this strategy helps the AUV move in a trajectory sufficiently close to this line. The adjacency of the trajectory to the line leads to reasonably short travelling distances and avoids unsafe areas. Autopilots are designed using sliding mode controller. Two different engagement geometries are considered to evaluate the strategy’s performance:stationary target and moving target. The simulation results show that the strategy can provide sufficiently fast and smooth trajectories in both target situations.

  15. A Data Link Layer in Support of Swarming of Autonomous Underwater Vehicles

    Science.gov (United States)

    Jabba Molinares, Daladier

    2009-01-01

    Communication underwater is challenging because of the inherent characteristics of the media. First, common radio frequency (RF) signals utilized in wireless communications cannot be used under water. RF signals are attenuated in such as way that RF communication underwater is restricted to very few meters. As a result, acoustic-based…

  16. 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.

  17. Survivability design for a hybrid underwater vehicle

    International Nuclear Information System (INIS)

    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

  18. Deep‐sea, high‐resolution, hydrography and current measurements using an autonomous underwater vehicle: The overflow from the Strait of Sicily

    OpenAIRE

    Stansfield, Kate; Smeed, David A; Gasparini, Gian Pietro; McPhail, Stephen; Millard, Nick; Stevenson, Peter; Webb, Andy; Vetrano, Anna; Rabe, Benjamin

    2001-01-01

    AUTOSUB‐2, an autonomous underwater vehicle (AUV) developed by the Southampton Oceanography Centre, was used for high resolution hydrographic surveys in the Sicily Strait. A combination of “seasoar” type profiling and terrain following missions were undertaken and velocity and hydrographic measurements taken from AUTOSUB‐2 were compared with concurrent shipboard hydrographic and velocity profiles. Even though shipboard stations were separated by just 5 to 8 km along the mission path, data fro...

  19. Dynamic Sliding Mode Control Based on Multi-model Switching Laws for the Depth Control of an Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Huanyin Zhou

    2015-07-01

    Full Text Available This manuscript presents an improved control algorithm, called Dynamic Sliding Mode Control based on Multiple Models Switching Laws (DSMC-MMSL, for the control of the depth of the studied Autonomous Underwater Vehicle (AUV system, the diving plane controller of which faces disturbances arising from the coupled states. The diving plane model is strongly coupled with the state variables, such as surge speeds and course angles. To achieve the desired dynamic performance, the proposed algorithm consists of two parts: the diving plane control part and the pitch control part, which is used to avoid large pitch angles. Some direct switching control laws are used for the two parts to avoid some impulse phenomena on the control executions. The error-states exponential decay is recommended to eliminate the chattering on the sliding surface. The DSMC-MMSL controller was successfully implemented and experimentally validated with the studied AUV system designed and built by Shenyang Institute of Automation. The results of some lake trials demonstrated that the depth control performances of the AUV system were as desired, and that the AUV system was robust enough for the coupled state variables under the DSMCMMSL algorithm control.

  20. Hydrodynamic Modeling for Autonomous Underwater Vehicles Using Computational and Semi-Empirical Methods

    OpenAIRE

    Geisbert, Jesse Stuart

    2007-01-01

    Buoyancy driven underwater gliders, which locomote by modulating their buoyancy and their attitude with moving mass actuators and inflatable bladders, are proving their worth as efficient long-distance, long-duration ocean sampling platforms. Gliders have the capability to travel thousands of kilometers without a need to stop or recharge. There is a need for the development of methods for hydrodynamic modeling. This thesis aims to determine the hydrodynamic parameters for the governing equat...

  1. A Feature Based Navigation System for an Autonomous Underwater Robot

    OpenAIRE

    Folkesson, John; Leederkerken, Jacques; Williams, Rob; Patrikalakis, Andrew; Leonard, John,

    2008-01-01

    International audience We present a system for autonomous underwater navigation as implemented on a Nekton Ranger autonomous underwater vehicle, AUV. This is one of the first implementations of a practical application for simultaneous localization and mapping on an AUV. Besides being an application of real-time SLAM, the implemtation demonstrates a novel data fusion solution where data from 7 sources are fused at different time scales in 5 separate estimators. By modularizing the data fusi...

  2. Integrated synoptic surveys using an autonomous underwater vehicle and manned boats

    Science.gov (United States)

    Jackson, P. Ryan

    2013-01-01

    Traditional surface-water surveys are being combined with autonomous technology to produce integrated surveys of bathymetry, water quality, and velocity in inland lakes and reservoirs. This new technology provides valuable, high-resolution, integrated data that allow a systems-based approach to understanding common environmental problems. This fact sheet presents several example applications of integrated surveys within inland lakes and coastal Lake Michigan and Lake Erie.

  3. Altered niche of an ecologically significant urchin species, Centrostephanus rodgersii, in its extended range revealed using an Autonomous Underwater Vehicle

    Science.gov (United States)

    Perkins, Nicholas R.; Hill, Nicole A.; Foster, Scott D.; Barrett, Neville S.

    2015-03-01

    Poleward range shifts of species as a result of global climate change are being increasingly documented. As species extend into new ranges their ecological impacts and the niches that they occupy may be unpredictable. We use benthic imagery obtained from the broad-scale deployment of an Autonomous Underwater Vehicle (AUV) to quantify the depth distribution of barrens habitat formed by a recent range extension of the sea urchin species, Centrostephanus rodgersii, a known ecosystem engineer. AUV transects covering similar depths from both the historical range of New South Wales, Australia, and from the range extension area of the east coast of Tasmania were examined for the presence of barrens. We find that C. rodgersii occupies a different realised niche in its extended range, with barrens habitat occurring significantly deeper in Tasmanian waters (16-58 m) compared to NSW waters (7-27 m). The expansion of barrens habitat has devastating impacts on biodiversity, with flow-on effects to ecosystem services and local fisheries, and in Tasmania this threat extends to deeper, invertebrate-dominated habitats. This finding has important management implications, in particular the need to incorporate deeper reef systems into planning, with increased barrens expected under future climate change predictions. One conservation management approach is the use of no-take Marine Protected Areas (MPAs) to prevent barren establishment in representative habitats by rebuilding viable populations of urchin predators. We also examine the correlation between MPA status and the occurrence of barrens within a small, no-take Tasmanian reserve and adjacent control sites. We find that there is suggestive, but inconclusive, evidence for fewer barrens in the MPA (p = 0.07). Our study highlights the utility of a novel technology for conducting large-scale benthic surveys and monitoring the impacts of range extending species.

  4. Postcaldera volcanism and hydrothermal activity revealed by autonomous underwater vehicle surveys in Myojin Knoll caldera, Izu-Ogasawara arc

    Science.gov (United States)

    Honsho, Chie; Ura, Tamaki; Kim, Kangsoo; Asada, Akira

    2016-06-01

    Myojin Knoll caldera, one of the submarine silicic calderas lying on the volcanic front of the northern Izu-Ogasawara arc, has attracted increasing attention since the discovery of a large hydrothermal field called the Sunrise deposit. Although numerous submersible surveys have been conducted in Myojin Knoll caldera, they have not sufficiently explored areas to produce a complete picture of the caldera and understand the origin of the Sunrise deposit. We conducted comprehensive deep-sea surveys using an autonomous underwater vehicle and obtained high-resolution bathymetric and magnetic data and sonar images from ~70% of the caldera. The detailed bathymetric map revealed that faulting and magma eruptions, possibly associated with an inflation-deflation cycle of the magma reservoir during postcaldera volcanism, had generally occurred in the caldera wall. The main dome of the central cone was covered with lava flows and exhibits exogenous growth, which is unusual for rhyolitic domes. The magnetization distribution in the central cone indicates preferential magma intrusion along a NW-SE direction. It is presumed that magma migrated along this direction and formed a rhyolite dome at the foot of the southeastern caldera wall, where the Sunrise deposit occurs. The Sunrise deposit is composed mainly of three ridges extending in slope directions and covers ~400 × ~400 m. Magnetization reduction in the deposit area is small, indicating that the alteration zone beneath the Sunrise deposit is slanting rather than vertical. It is presumed that several slanting and near-vertical volcanic vents serve as pathways of hydrothermal fluid in Myojin Knoll caldera.

  5. Model-aided Navigation with Sea Current Estimation for an Autonomous Underwater Vehicle

    OpenAIRE

    Alain Martinez; Luis Hernandez; Hichem Sahli; Yunier Valeriano-Medina; Maykel Orozco-Monteagudo; Delvis Garcia-Garcia

    2015-01-01

    This paper presents a strategy to improve the navigation solution of the HRC-AUV by deploying a model-aided inertial navigation system (MA-INS). Based on a simpler three-DOF linear dynamic model (DM) of the vehicle, and implemented through a Kalman filter (KF), the performance of the proposed MA-INS is compared to state-of-the-art solutions based on non-linear models. The model allows the online estimation of the sea current parameters before and during the navigation mission. Qualitative and...

  6. Potential of autonomous underwater vehicles as new generation ocean data platforms

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.; Madhan, R.; Maurya, P.

    depths of 3000 m. The HUGIN f amily of AUVs from Norway has been used extensively in bathymetric su r veys, the MIT Odyssey vehicle in surveys of coastal fronts in the Hero Strait, British Colombia in 1996, and the laying of the 175 km long fibre... . The mea s- ured d rag c o efficient is ~0.310 at 1.5 m/s. Other features on the MAYA AUV include a communications stub co n- taining the GPS and RF antenna mounted near the stern plane region, and a Doppler V e locity Log (DVL) that is used...

  7. Fusion of Redundant Aided-inertial Sensors with Decentralised Kalman Filter for Autonomous Underwater Vehicle Navigation

    Directory of Open Access Journals (Sweden)

    Vaibhav Awale

    2015-11-01

    Full Text Available Most submarines carry more than one set of inertial navigation system (INS for redundancy and reliability. Apart from INS systems, the submarine carries other sensors that provide different navigation information. A major challenge is to combine these sensors and INS estimates in an optimal and robust manner for navigation. This issue has been addressed by Farrell1. The same approach is used in this paper to combine different sensor measurements along with INS system. However, since more than one INS system is available onboard, it would be better to use multiple INS systems at the same time to obtain a better estimate of states and to provide autonomy in the event of failure of one INS system. This would require us to combine the estimates obtained from local filters (one set of INS system integrated with external sensors, in some optimal way to provide a global estimate. Individual sensor and IMU measurements cannot be accessed in this scenario. Also, autonomous operation requires no sharing of information among local filters. Hence a decentralised Kalman filter approach is considered for combining the estimates of local filters to give a global estimate. This estimate would not be optimal, however. A better optimal estimate can be obtained by accessing individual measurements and augmenting the state vector in Kalman filter, but in that case, corruption of one INS system will lead to failure of the whole filter. Hence to ensure satisfactory performance of the filter even in the event of failure of some INS system, a decentralised Kalman filtering approach is considered.

  8. Model-aided Navigation with Sea Current Estimation for an Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Alain Martinez

    2015-07-01

    Full Text Available This paper presents a strategy to improve the navigation solution of the HRC-AUV by deploying a model-aided inertial navigation system (MA-INS. Based on a simpler three-DOF linear dynamic model (DM of the vehicle, and implemented through a Kalman filter (KF, the performance of the proposed MA-INS is compared to state-of-the-art solutions based on non-linear models. The model allows the online estimation of the sea current parameters before and during the navigation mission. Qualitative and quantitative evaluations as well as a statistical significance test are performed using both simulated and real data, demonstrating the usefulness of the proposed model-aided navigation.

  9. Tracking Control of Autonomous Underwater Vehicles with Internal Moving Mass%自主水下航行器的变质心跟踪控制

    Institute of Scientific and Technical Information of China (English)

    李家旺; 宋保维; 邵成

    2008-01-01

    The trajectory-tracking control problem is inves-tigated for an autonomous underwater vehicle (AUV) moving in the vertical plane using an internal point mass and a rear thruster as actuators. Combined with the dynamics of the point mass, the AUV is modeled as an underactuated system. A Lyapunov-based tracking controller is proposed by using back-stepping approach to stabilize the error dynamics and forcc the position errors to a small neighborhood of thc origin. Simulation results validate the proposcd tracking approach.

  10. Autonomous vehicle development for vertical submarine observation

    OpenAIRE

    Gomáriz Castro, Spartacus; Prat Tasias, Jordi; Arbós, Alejandro; Viñolo Monzoncillo, Carlos; Pallares, Oriol

    2009-01-01

    This work proposes the development of an ocean observation vehicle. This vehicle, a hybrid between Autonomous Underwater Vehicles (AUV) and Autonomous Surface Vehicles (ASV) moves on the surface of the sea and makes vertical immersions to obtain the profiles of a water column according to a pre-established plan. Its design provides lower production cost and higher efficiency. GPS navigation allows the platform to move along the surface of the water while a radio-modem provid...

  11. Navigating Autonomous Underwater Vehicles

    OpenAIRE

    Bingham, Brian

    2009-01-01

    The Deep Submergence Lab at Woods Hole Oceanographic provided the data and images used in developing the illustrations in Fig. 2 and Fig. 3. Also, Joel Gendron illustrated Fig. 4. The publication of this chapter was supported by the Franklin W. Olin College of Engineering in Needham, Massachusetts.

  12. Intelligent Navigation for a Solar Powered Unmanned Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Francisco García-Córdova

    2013-04-01

    Full Text Available In this paper, an intelligent navigation system for an unmanned underwater vehicle powered by renewable energy and designed for shadow water inspection in missions of a long duration is proposed. The system is composed of an underwater vehicle, which tows a surface vehicle. The surface vehicle is a small boat with photovoltaic panels, a methanol fuel cell and communication equipment, which provides energy and communication to the underwater vehicle. The underwater vehicle has sensors to monitor the underwater environment such as sidescan sonar and a video camera in a flexible configuration and sensors to measure the physical and chemical parameters of water quality on predefined paths for long distances. The underwater vehicle implements a biologically inspired neural architecture for autonomous intelligent navigation. Navigation is carried out by integrating a kinematic adaptive neuro‐controller for trajectory tracking and an obstacle avoidance adaptive neuro‐controller. The autonomous underwater vehicle is capable of operating during long periods of observation and monitoring. This autonomous vehicle is a good tool for observing large areas of sea, since it operates for long periods of time due to the contribution of renewable energy. It correlates all sensor data for time and geodetic position. This vehicle has been used for monitoring the Mar Menor lagoon.

  13. On Ocean Environment Monitoring System the Autonomous Underwater Vehicle%自主式水下潜器海洋环境监测系统技术概念

    Institute of Scientific and Technical Information of China (English)

    边信黔; 陈伟; 施小成

    2000-01-01

    介绍了被誉为未来海洋卫星的自主式水下潜器AUV(Autonomous Underwater Vehicles )的国外发展新动态、自主式海洋采样网络AOSN (Autonomous Ocean Sampling Network)和海洋中的"卫星”技术概念和应用前景.

  14. Linking catchment-scale subglacial discharge to subsurface glacially modified waters near the front of a marine terminating outlet glacier using an autonomous underwater vehicle

    Science.gov (United States)

    Stevens, L. A.; Straneo, F.; Das, S. B.; Plueddemann, A. J.; Kukulya, A. L.; Morlighem, M.

    2015-09-01

    Measurements of near-ice (Autonomous Underwater Vehicle as close as 150 m from the ice/ocean interface of the Sarqardliup sermia/Sarqardleq Fjord system, West Greenland, with modeled and observed subglacial discharge locations and magnitudes. We find evidence of two main types of subsurface glacially modified water localized in space and with distinct properties that are consistent with runoff discharged at two locations along the grounded margin. These locations, in turn, correspond with two prominent subglacial subcatchments beneath Sarqardliup sermia. Thus, near-ice observations and subglacial discharge routing indicate that subglacial discharge from this glacier occurs at only two primary locations and gives rise to two distinct glacially modified waters. Furthermore, we show that the location with the largest discharge flux is associated with the lighter, fresher glacially modified watermass. This is qualitatively consistent with results from an idealized plume model.

  15. Algorithms and analysis for underwater vehicle plume tracing.

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, Raymond Harry; Savage, Elizabeth L. (Texas A& M University, College Station, TX); Hurtado, John Edward (Texas A& M University, College Station, TX); Eskridge, Steven E.

    2003-07-01

    The goal of this research was to develop and demonstrate cooperative 3-D plume tracing algorithms for miniature autonomous underwater vehicles. Applications for this technology include Lost Asset and Survivor Location Systems (L-SALS) and Ship-in-Port Patrol and Protection (SP3). This research was a joint effort that included Nekton Research, LLC, Sandia National Laboratories, and Texas A&M University. Nekton Research developed the miniature autonomous underwater vehicles while Sandia and Texas A&M developed the 3-D plume tracing algorithms. This report describes the plume tracing algorithm and presents test results from successful underwater testing with pseudo-plume sources.

  16. Dead reckoning method for autonomous underwater vehicles based on EKF%基于EKF的无人潜航器航位推算算法

    Institute of Scientific and Technical Information of China (English)

    边信黔; 周佳加; 严浙平; 赵大威

    2011-01-01

    为了解决传感器的安装角偏离误差以及量测误差导致的无人潜航器(AUV)在水下自主航行时不能满足长时间导航定位的要求,对航位推算算法进行了研究.针对AUV在高纬度、长时间航行中曲率半径的变化,采用地球参考椭球体作为地球几何形状的数学描述;针对数据滤波实时性的要求,基于扩展卡尔曼滤波(EKF)对卫星导航系统(GPS)数据进行滤波,并利用AUV湖试数据对传感器的安装偏离误差进行了校正.对提出的导航算法进行了试验验证,结果表明AUV的自主导航定位精度为0.75%,满足设计要求,并优于改进前的航位推算算法.%Owing to the installation angle's deviation error of sensors and the measurement error, the autonomous underwater vehicle (AUV) could not meet the time requirements of navigation and posi tioning when it undertakes underwater autonomous navigation. For the navigation of the vehicle at a high latitude or long time, the earth reference ellipsoid was adopted to descript earth's geometry to adapt to the change of radius curvature. Thus, a dead reckoning method for unmanned underwater vehicle was studied based on extended Kalman filtering (EKF). And the installation angle's deviation error was corrected by the data from the lake experiment of AUV. Finally, the proposed navigation method was tested by lake experiment, resulting with a navigation accuracy of 0.75% which satisfied the design requirements. The experiment demonstrates that the dead reckoning method is more preferable than normal ones.

  17. Investigation into the Dynamics and Control of an Underwater Vehicle-Manipulator System

    OpenAIRE

    Mohan Santhakumar

    2013-01-01

    This study addresses the detailed modeling and simulation of the dynamic coupling between an underwater vehicle and manipulator system. The dynamic coupling effects due to damping, restoring, and inertial effects of an underwater manipulator mounted on an autonomous underwater vehicle (AUV) are analyzed by considering the actuator and sensor characteristics. A model reference control (MRC) scheme is proposed for the underwater vehicle-manipulator system (UVMS). The effectiveness of the propos...

  18. Integrated Positioning System of Autonomous Underwater Robot and Its Application in High Latitudes of Arctic Zone

    OpenAIRE

    Inzartsev, Alexander; Kamorniy, Alexander; Kiselyov, Lev; Matviyenko, Yury; Rylov, Nicolay; Rylov, Roman; Vaulin, Yury

    2010-01-01

    1. An autonomous unmanned underwater vehicle for scientific research was used for the first time in the world history under ice in the Arctic polar latitudes. The possibility of its use for bottom characteristics research was practically proved.

  19. Interception and Rendezvous Between Autonomous Vehicles

    OpenAIRE

    Crispin, Yechiel J.

    2008-01-01

    The interception and rendezvous problems between two autonomous vehicles moving in an underwater environment has been treated using an optimal control formulation with terminal constraints. The vehicles have a constant thrust propulsion system and use the direction of the thrust vector for steering and control. We use a genetic algorithm to determine directly the control history of the vehicle by evolving populations of possible solutions of initial value problems. In order to fulfill the fin...

  20. Relocating Underwater Features Autonomously Using Sonar-Based SLAM

    OpenAIRE

    Fallon, M.F.; Folkesson, J.; McClelland, H; Leonard, J.J.

    2013-01-01

    This paper describes a system for reacquiring features of interest in a shallow-water ocean environment, using autonomous underwater vehicles (AUVs) equipped with low-cost sonar and navigation sensors. In performing mine countermeasures, it is critical to enable AUVs to navigate accurately to previously mapped objects of interest in the water column or on the seabed, for further assessment or remediation. An important aspect of the overall system design is to keep the size and cost of the rea...

  1. Fitting primitive shapes in point clouds: a practical approach to improve autonomous underwater grasp specification of unknown objects

    OpenAIRE

    Fornas Garcia, David; Sales Gil, Jorge; Peñalver Monfort, Antonio; Pérez Soler, Javier; Fernández Fresneda, José Javier; Marín Prades, Raúl; Sanz Valero, Pedro José

    2015-01-01

    This article presents research on the subject of autonomous underwater robot manipulation. Ongoing research in underwater robotics intends to increase the autonomy of intervention operations that require physical interaction in order to achieve social benefits in fields such as archaeology or biology that cannot afford the expenses of costly underwater operations using remote operated vehicles. Autonomous grasping is still a very challenging skill, especially in underwater environments, with ...

  2. Visual feedback navigation for cable tracking by autonomous underwater vehicles; Jiritsugata kaichu robot no gazo shori ni motozuku cable jido tsuiju

    Energy Technology Data Exchange (ETDEWEB)

    Takai, M.; Ura, T. [The University of Tokyo, Tokyo (Japan). Institute of Industrial Science; Balasuriya, B.; Lam, W. [The University of Tokyo, Tokyo (Japan); Kuroda, Y. [Meiji Univ., Tokyo (Japan)

    1997-08-01

    A vision processing unit was introduced into autonomous underwater vehicles (AUV) to judge the visual situation and to construct an environmental observation platform that can collect wide-range and high-precision measurement data. The cable optionally installed at the bottom of the sea was recognized by vision processing to propose automatic tracking technique. An estimator that compensates for the hough conversion or time delay and a PSA controller that is used as a target value set mechanism or lower-level controller were introduced as the factor technology required for automatic tracking. The feature of the automatic tracking is that a general-purpose platform which can observe the prescribed range environmentally in high precision and density can be constructed because the observation range required by the observer can be prescribed near the sea-bottom surface using a cable. The verification result off Omi Hachiman at Lake Biwa showed that AUV can be used for the high-precision environmental survey in the range prescribed near the sea-bottom surface using a cable. 8 refs., 8 figs., 1 tab.

  3. Design and simulation of ex-range gliding wing of high altitude air-launched autonomous underwater vehicles based on SIMULINK

    Institute of Scientific and Technical Information of China (English)

    Pan Changjun; Guo Yingqing

    2013-01-01

    High altitude air-launched autonomous underwater vehicle (AL-AUV) is a new anti-submarine field,which is designed on the Lockheed Martin's high altitude anti-submarine warfare weapons concept (HAAWC) and conducts the basic aerodynamic feasibility in a series of wind tunnel trials.The AL-AUV is composed of a traditional torpedo-like AUV,an additional ex-range gliding wings unit and a descending parachute unit.In order to accurately and conveniently investigate the dynamic and static characteristic of high altitude AL-AUV,a simulation platform is established based on MATLAB/SIMULINK and an AUV 6DOF (Degree of Freedom) dynamic model.Executing the simulation platform for different wing's parameters and initial fixing angle,a set of AUV gliding data is generated.Analyzing the recorded simulation result,the velocity and pitch characteristics of AL-AUV deployed at varying wing areas and initial setting angle,the optimal wing area is selected for specific AUV model.Then the comparative simulations of AL-AUV with the selected wings are completed,which simulate the AUV gliding through idealized windless air environment and gliding with Dryden wind influence.The result indicates that the method of wing design and simulation with the simulation platform based on SIMULINK is accurately effective and suitable to be widely employed.

  4. Autonomous Underwater Navigation and Optical Mapping in Unknown Natural Environments

    Directory of Open Access Journals (Sweden)

    Juan David Hernández

    2016-07-01

    Full Text Available We present an approach for navigating in unknown environments while, simultaneously, gathering information for inspecting underwater structures using an autonomous underwater vehicle (AUV. To accomplish this, we first use our pipeline for mapping and planning collision-free paths online, which endows an AUV with the capability to autonomously acquire optical data in close proximity. With that information, we then propose a reconstruction pipeline to create a photo-realistic textured 3D model of the inspected area. These 3D models are also of particular interest to other fields of study in marine sciences, since they can serve as base maps for environmental monitoring, thus allowing change detection of biological communities and their environment over time. Finally, we evaluate our approach using the Sparus II, a torpedo-shaped AUV, conducting inspection missions in a challenging, real-world and natural scenario.

  5. Autonomous Underwater Navigation and Optical Mapping in Unknown Natural Environments.

    Science.gov (United States)

    Hernández, Juan David; Istenič, Klemen; Gracias, Nuno; Palomeras, Narcís; Campos, Ricard; Vidal, Eduard; García, Rafael; Carreras, Marc

    2016-01-01

    We present an approach for navigating in unknown environments while, simultaneously, gathering information for inspecting underwater structures using an autonomous underwater vehicle (AUV). To accomplish this, we first use our pipeline for mapping and planning collision-free paths online, which endows an AUV with the capability to autonomously acquire optical data in close proximity. With that information, we then propose a reconstruction pipeline to create a photo-realistic textured 3D model of the inspected area. These 3D models are also of particular interest to other fields of study in marine sciences, since they can serve as base maps for environmental monitoring, thus allowing change detection of biological communities and their environment over time. Finally, we evaluate our approach using the Sparus II, a torpedo-shaped AUV, conducting inspection missions in a challenging, real-world and natural scenario. PMID:27472337

  6. Close-range tracking of underwater vehicles using light beacons

    OpenAIRE

    Bosch Alay, Josep; Grácias, Nuno Ricardo Estrela; Ridao Rodríguez, Pere; Istenič, Klemen; Ribas Romagós, David

    2016-01-01

    This paper presents a new tracking system for autonomous underwater vehicles (AUVs) navigating in a close formation, based on computer vision and the use of active light markers. While acoustic localization can be very effective from medium to long distances, it is not so advantageous in short distances when the safety of the vehicles requires higher accuracy and update rates. The proposed system allows the estimation of the pose of a target vehicle at short ranges, with high accuracy and exe...

  7. Close-Range Tracking of Underwater Vehicles Using Light Beacons

    OpenAIRE

    Bosch, Josep; Gracias, Nuno; Ridao, Pere; Istenič, Klemen; Ribas, David

    2016-01-01

    This paper presents a new tracking system for autonomous underwater vehicles (AUVs) navigating in a close formation, based on computer vision and the use of active light markers. While acoustic localization can be very effective from medium to long distances, it is not so advantageous in short distances when the safety of the vehicles requires higher accuracy and update rates. The proposed system allows the estimation of the pose of a target vehicle at short ranges, with high accuracy and exe...

  8. SEATURTLE: Sustained Engagement Autonomous Tracking of Underwater RepTiLEs

    OpenAIRE

    Budd, Johnathan

    2015-01-01

    While oceans cover the majority of our planet, these vast expanses remain relatively unexplored. Among the most interesting parts of the ocean are the shallow reef systems, which contain a huge amount of the planet’s biodiversity. The Sustained Engagement Autonomous Tracking of Underwater RepTiLEs or SEATURTLE is a low cost Autonomous Underwater Vehicle designed to carry out missions in these shallow environments. Its small displacement and precise movement make it ideal for navigating tight ...

  9. USE OF A LONG ENDURANCE SOLAR POWERED AUTONOMOUS UNDERWATER VEHICLE (SAUV II) TO MEASURE DISSOLVED OXYGEN CONCENTRATIONS IN GREENWICH BAY, RHODE ISLAND, USA

    Science.gov (United States)

    As hypoxic water masses increase worldwide in duration and extent due to coastal eutrophication, advanced technology water quality monitoring by autonomous vehicles can increase our capability to document and respond to these environmental perturbations. We evaluated the use of a...

  10. Evaluation of an Efficient Approach for Target Tracking from Acoustic Imagery for the Perception System of an Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Sebastián A. Villar

    2014-02-01

    Current techniques for acoustic data processing are time and computationally intensive. Hence, it was decided to process data coming from a SSS using a technique that is used for radars, due to its efficiency and its amenability to on-line processing. The engineering problem to solve in this case was underwater pipeline tracking for routine inspections in the off-shore industry. Then, an automatic oil pipeline detection system was developed borrowing techniques from the processing of radar measurements. The radar technique is known as Cell Average – Constant False Alarm Rate (CA – CFAR. With a slight variation of the algorithms underlying this radar technique, which consisted of the previous accumulation of partial sums, a great improvement in computing time and effort was achieved. Finally, a comparison with previous approaches over images acquired with a SSS from a vessel in the Salvador de Bahia bay in Brazil showed the feasibility of using this on-board technique for AUV perception.

  11. Integrated synoptic surveys of the hydrodynamics and water-quality distributions in two Lake Michigan rivermouth mixing zones using an autonomous underwater vehicle and a manned boat

    Science.gov (United States)

    Jackson, P. Ryan; Reneau, Paul C.

    2014-01-01

    The U.S. Geological Survey (USGS), in cooperation with the National Monitoring Network for U.S. Coastal Waters and Tributaries, launched a pilot project in 2010 to determine the value of integrated synoptic surveys of rivermouths using autonomous underwater vehicle technology in response to a call for rivermouth research, which includes study domains that envelop both the fluvial and lacustrine boundaries of the rivermouth mixing zone. The pilot project was implemented at two Lake Michigan rivermouths with largely different scales, hydrodynamics, and settings, but employing primarily the same survey techniques and methods. The Milwaukee River Estuary Area of Concern (AOC) survey included measurements in the lower 2 to 3 miles of the Milwaukee, Menomonee, and Kinnickinnic Rivers and inner and outer Milwaukee Harbor. This estuary is situated in downtown Milwaukee, Wisconsin, and is the most populated basin that flows directly into Lake Michigan. In contrast, the Manitowoc rivermouth has a relatively small harbor separating the rivermouth from Lake Michigan, and the Manitowoc River Watershed is primarily agricultural. Both the Milwaukee and Manitowoc rivermouths are unregulated and allow free exchange of water with Lake Michigan. This pilot study of the Milwaukee River Estuary and Manitowoc rivermouth using an autonomous underwater vehicle (AUV) paired with a manned survey boat resulted in high spatial and temporal resolution datasets of basic water-quality parameter distributions and hydrodynamics. The AUV performed well in these environments and was found primarily well-suited for harbor and nearshore surveys of three-dimensional water-quality distributions. Both case studies revealed that the use of a manned boat equipped with an acoustic Doppler current profiler (ADCP) and multiparameter sonde (and an optional flow-through water-quality sampling system) was the best option for riverine surveys. To ensure that the most accurate and highest resolution velocity data

  12. Experimental Autonomous Vehicle Systems

    DEFF Research Database (Denmark)

    Ravn, Ole; Andersen, Nils Axel

    1998-01-01

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

  13. Spatially complex distribution of dissolved manganese in a fjord as revealed by high-resolution in situ sensing using the autonomous underwater vehicle Autosub.

    Science.gov (United States)

    Statham, P J; Connelly, D P; German, C R; Brand, T; Overnell, J O; Bulukin, E; Millard, N; McPhail, S; Pebody, M; Perrett, J; Squire, M; Stevenson, P; Webb, A

    2005-12-15

    Loch Etive is a fjordic system on the west coast of Scotland. The deep waters of the upper basin are periodically isolated, and during these periods oxygen is lost through benthic respiration and concentrations of dissolved manganese increase. In April 2000 the autonomous underwater vehicle (AUV) Autosub was fitted with an in situ dissolved manganese analyzer and was used to study the spatial variability of this element together with oxygen, salinity, and temperature throughout the basin. Six along-loch transects were completed at either constant height above the seafloor or at constant depth below the surface. The ca. 4000 in situ 10-s-average dissolved Mn (Mnd) data points obtained provide a new quasi-synoptic and highly detailed view of the distribution of manganese in this fjordic environment not possible using conventional (water bottle) sampling. There is substantial variability in concentrations (600 nM) and distributions of Mnd. Surface waters are characteristically low in Mnd reflecting mixing of riverine and marine end-member waters, both of which are low in Mnd. The deeper waters are enriched in Mnd, and as the water column always contains some oxygen, this must reflect primarily benthic inputs of reduced dissolved Mn. However, this enrichment of Mnd is spatially very variable, presumably as a result of variability in release of Mn coupled with mixing of water in the loch and removal processes. This work demonstrates how AUVs coupled with chemical sensors can reveal substantial small-scale variability of distributions of chemical species in coastal environments that would not be resolved by conventional sampling approaches. Such information is essential if we are to improve our understanding of the nature and significance of the underlying processes leading to this variability. PMID:16475319

  14. Modeling and Simulation of A Novel Autonomous Underwater Vehicle with Glider and Flapping-Foil Propulsion Capabilities

    Institute of Scientific and Technical Information of China (English)

    TIAN Wen-long; SONG Bao-wei; DU Xiao-xu; MAO Zhao-yong; DING Hao

    2012-01-01

    HAISHEN is a long-ranged and highly maneuverable AUV which has two operating modes:glider mode and flapping-foil propulsion mode.As part of the vehicle development,a three-dimensional mathematical model of the conceptual vehicle was developed on the assumption that HAISHEN has a rigid body with two independently controlled oscillating hydrofoils.A flapping-foil model was developed based on the work done by Georgiades et al.(2009).Effect of controllable hydrofoils on the vehicle stable motion performance was studied theoretically.Finally,a dynamics simulation of the vehicle in both operating modes is created in this paper.The simulation demonstrates that:(1) in the glider mode,owing to the independent control of the pitch angle of each hydrofoil,HAISHEN travels faster and more efficiently and has a smaller turning radius than conventional fix-winged gliders; (2) in the flapping-foil propulsion mode,HAISHEN has a high maneuverability with a turning radius smaller than 15 m and a forward motion velocity about 1.8 m/s; (3) the vehicle is stable under all expected operating conditions.

  15. Design, Development and Testing of Underwater Vehicles: ITB Experience

    CERN Document Server

    Muljowidodo, Said D; Budiyono, Agus; Nugroho, Sapto A

    2008-01-01

    The last decade has witnessed increasing worldwide interest in the research of underwater robotics with particular focus on the area of autonomous underwater vehicles (AUVs). The underwater robotics technology has enabled human to access the depth of the ocean to conduct environmental surveys, resources mapping as well as scientific and military missions. This capability is especially valuable for countries with major water or oceanic resources. As an archipelagic nation with more than 13,000 islands, Indonesia has one of the most abundant living and non-organic oceanic resources. The needs for the mapping, exploration, and environmental preservation of the vast marine resources are therefore imperative. The challenge of the deep water exploration has been the complex issues associated with hazardous and unstructured undersea and sea-bed environments. The paper reports the design, development and testing efforts of underwater vehicle that have been conducted at Institut Teknologi Bandung. Key technology areas...

  16. Jellyfish inspired underwater unmanned vehicle

    Science.gov (United States)

    Villanueva, Alex; Bresser, Scott; Chung, Sanghun; Tadesse, Yonas; Priya, Shashank

    2009-03-01

    An unmanned underwater vehicle (UUV) was designed inspired by the form and functionality of a Jellyfish. These natural organisms were chosen as bio-inspiration for a multitude of reasons including: efficiency of locomotion, lack of natural predators, proper form and shape to incorporate payload, and varying range of sizes. The structure consists of a hub body surrounded by bell segments and microcontroller based drive system. The locomotion of UUV was achieved by shape memory alloy "Biometal Fiber" actuation which possesses large strain and blocking force with adequate response time. The main criterion in design of UUV was the use of low-profile shape memory alloy actuators which act as artificial muscles. In this manuscript, we discuss the design of two Jellyfish prototypes and present experimental results illustrating the performance and power consumption.

  17. Navigation System Fault Diagnosis for Underwater Vehicle

    DEFF Research Database (Denmark)

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

    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...

  18. Forces and moments due to unsteady motion of an underwater vehicle

    OpenAIRE

    Oller, Erik D.

    2003-01-01

    CIVINS This research examines the effect of unsteady motion on the forces and moments experienced by an underwater vehicle in shallow water. The test platform is the REMUS Autonomous Underwater Vehicle developed by the Woods Hole Oceanographic Institution, although the results are made non-dimensional to be applicable to a wide range of similar shaped vehicles. The experimental model was moved in sinusoidal motion at various submergences, speeds, frequencies of oscillation, and amplitudes ...

  19. SOLON: An autonomous vehicle mission planner

    Science.gov (United States)

    Dudziak, M. J.

    1987-01-01

    The State-Operator Logic Machine (SOLON) Planner provides an architecture for effective real-time planning and replanning for an autonomous vehicle. The highlights of the system, which distinguish it from other AI-based planners that have been designed previously, are its hybrid application of state-driven control architecture and the use of both schematic representations and logic programming for the management of its knowledge base. SOLON is designed to provide multiple levels of planning for a single autonomous vehicle which is supplied with a skeletal, partially-specified mission plan at the outset of the vehicle's operations. This mission plan consists of a set of objectives, each of which will be decomposable by the planner into tasks. These tasks are themselves comparatively complex sets of actions which are executable by a conventional real-time control system which does not perform planning but which is capable of making adjustments or modifications to the provided tasks according to constraints and tolerances provided by the Planner. The current implementation of the SOLON is in the form of a real-time simulation of the Planner module of an Intelligent Vehicle Controller (IVC) on-board an autonomous underwater vehicle (AUV). The simulation is embedded within a larger simulator environment known as ICDS (Intelligent Controller Development System) operating on a Symbolics 3645/75 computer.

  20. Robotics Vision-Based System of Autonomous Underwater Vehicle for an Underwater Pipeline Tracker%自主式水下机器人的光视觉管道探测跟踪系统

    Institute of Scientific and Technical Information of China (English)

    曾文静; 徐玉如; 万磊; 张铁栋

    2012-01-01

    The detection and tracking of underwater pipeline based on monocular vision system of AUV(autonomous underwater vehicle) were addressed.An integrated vision system including software and hardware structure was designed.The feature of underwater pipeline image was analyzed and according to that,corresponding pre-processing method was proposed.An improved Hough transforming was advanced to obtain pipeline contour.Pipeline reference zone was estimated to increase the accuracy and decrease the time cost of pipeline tracking.Finally,the system was validated to be effective and feasible through the tank experiments.%研究了自主式水下机器人(AUV)利用单目光视觉系统对水下管道的检测跟踪问题,对实现该方法的各个过程从硬件组成和软件体系结构两方面进行了阐述,从而完成了一整套水下光视觉系统的软、硬件设计.分析了水下管道图像的特点,结合该特点阐述了图像预处理过程,提出了一种改进的Hough变换方法,改善了管道边界的提取效果.同时采用管道参考区域预测方法,提高了管道的检测率以及实时性,并利用水池试验对系统的可行性和有效性进行了验证.

  1. A Spatial Reference Grid for Real-Time Autonomous Underwater Modeling using 3-D Sonar

    Energy Technology Data Exchange (ETDEWEB)

    Auran, P.G.

    1996-12-31

    The offshore industry has recognized the need for intelligent underwater robotic vehicles. This doctoral thesis deals with autonomous underwater vehicles (AUVs) and concentrates on a data representation for real-time image formation and analysis. Its main objective is to develop a 3-D image representation suitable for autonomous perception objectives underwater, assuming active sonar as the main sensor for perception. The main contributions are: (1) A dynamical image representation for 3-D range data, (2) A basic electronic circuit and software system for 3-D sonar sampling and amplitude thresholding, (3) A model for target reliability, (4) An efficient connected components algorithm for 3-D segmentation, (5) A method for extracting general 3-D geometrical representations from segmented echo clusters, (6) Experimental results of planar and curved target modeling. 142 refs., 120 figs., 10 tabs.

  2. Intelligent Navigation for a Solar Powered Unmanned Underwater Vehicle

    OpenAIRE

    Francisco García-Córdova; Antonio Guerrero-González

    2013-01-01

    In this paper, an intelligent navigation system for an unmanned underwater vehicle powered by renewable energy and designed for shadow water inspection in missions of a long duration is proposed. The system is composed of an underwater vehicle, which tows a surface vehicle. The surface vehicle is a small boat with photovoltaic panels, a methanol fuel cell and communication equipment, which provides energy and communication to the underwater vehicle. The underwater v...

  3. Autopilot Control Synthesis for Path Tracking Maneuvers of Underwater Vehicles

    Institute of Scientific and Technical Information of China (English)

    Sam-Sang YOU; Hyeung-Sik CHOI; Hwan-Seong KIM; Han-Il PARK

    2011-01-01

    This paper is concerned with the robust control synthesis of autonomous underwater vehicle (AUV) for general path following maneuvers. First, we present maneuvering kinematics and vehicle dynamics in a unified framework. Based on H loop-shaping procedure, the 2-DOF autopilot controller has been presented to enhance stability and path tracking.By use of model reduction, the high-order control system is reduced to one with reasonable order, and further the scaled low-order controller has been analyzed in both the frequency and the time domains. Finally, it is shown that the autopilot control system provides robust performance and stability against prescribed levels of uncertainty.

  4. Autonomous Vehicles Navigation with Visual Target Tracking: Technical Approaches

    Directory of Open Access Journals (Sweden)

    Zhen Jia

    2008-12-01

    Full Text Available This paper surveys the developments of last 10 years in the area of vision based target tracking for autonomous vehicles navigation. First, the motivations and applications of using vision based target tracking for autonomous vehicles navigation are presented in the introduction section. It can be concluded that it is very necessary to develop robust visual target tracking based navigation algorithms for the broad applications of autonomous vehicles. Then this paper reviews the recent techniques in three different categories: vision based target tracking for the applications of land, underwater and aerial vehicles navigation. Next, the increasing trends of using data fusion for visual target tracking based autonomous vehicles navigation are discussed. Through data fusion the tracking performance is improved and becomes more robust. Based on the review, the remaining research challenges are summarized and future research directions are investigated.

  5. Prototype design for autonomous vehicle

    OpenAIRE

    Lehander, Jacob; Persson, Joel

    2015-01-01

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

  6. Close-Range Tracking of Underwater Vehicles Using Light Beacons

    Science.gov (United States)

    Bosch, Josep; Gracias, Nuno; Ridao, Pere; Istenič, Klemen; Ribas, David

    2016-01-01

    This paper presents a new tracking system for autonomous underwater vehicles (AUVs) navigating in a close formation, based on computer vision and the use of active light markers. While acoustic localization can be very effective from medium to long distances, it is not so advantageous in short distances when the safety of the vehicles requires higher accuracy and update rates. The proposed system allows the estimation of the pose of a target vehicle at short ranges, with high accuracy and execution speed. To extend the field of view, an omnidirectional camera is used. This camera provides a full coverage of the lower hemisphere and enables the concurrent tracking of multiple vehicles in different positions. The system was evaluated in real sea conditions by tracking vehicles in mapping missions, where it demonstrated robust operation during extended periods of time. PMID:27023547

  7. Close-Range Tracking of Underwater Vehicles Using Light Beacons.

    Science.gov (United States)

    Bosch, Josep; Gracias, Nuno; Ridao, Pere; Istenič, Klemen; Ribas, David

    2016-01-01

    This paper presents a new tracking system for autonomous underwater vehicles (AUVs) navigating in a close formation, based on computer vision and the use of active light markers. While acoustic localization can be very effective from medium to long distances, it is not so advantageous in short distances when the safety of the vehicles requires higher accuracy and update rates. The proposed system allows the estimation of the pose of a target vehicle at short ranges, with high accuracy and execution speed. To extend the field of view, an omnidirectional camera is used. This camera provides a full coverage of the lower hemisphere and enables the concurrent tracking of multiple vehicles in different positions. The system was evaluated in real sea conditions by tracking vehicles in mapping missions, where it demonstrated robust operation during extended periods of time. PMID:27023547

  8. Insights into High-Resolution Physico-Biogeochemical Processes in Nearshore Environments of Lake Erie Using an Autonomous Underwater Vehicle (AUV)

    Science.gov (United States)

    Roehm, C. L.; Vermette, S.; Perrelli, M.; Bauer, K.; Jerla, B.

    2012-12-01

    The goal of this project is to gain a better understanding of the physico-chemical-biological dynamics in nearshore areas of Lake Erie as a function of environmental and climate change. Nearshore processes in the Great Lakes are complex and drive many efforts in remediating areas of concern (AoCs). Long term studies of the processes and the dynamics of these environments are necessary to determine the success of management strategies and the application of policies. A network of monitoring buoys can provide an insight into long term temporal changes in the system, however, the spatial resolution is rather coarse. As part of a nearshore buoy observations study on the long-term impacts of climate and environmental change on Lake Erie the deployment of an automated underwater vehicle (AUV) compliments and augments the data obtained by the buoys by providing direct high spatial resolution observations. The high resolution data will be used to improve parameter estimates of water circulation and water quality parameters for models (FVCOM) that often cannot accurately predict nearshore surface and subsurface dynamics. An AUV equipped with water quality instrumentation as well as an acoustic doppler current profiler and side scan sonar was deployed in a gridded pattern at multiple locations along the shoreline of Lake Erie throughout the summer of 2012. The data presented here describe and capture at, high spatial resolution, the nearshore-offshore characteristics and inter-relationships of lake bottom morphology, water quality and current patterns and provide an insight into the complex processes and dynamics of these regions. These data will provide a better understanding of nearshore lake processes that can be used to improve current model parameters and inform both science at large and management strategies.

  9. A small-scale comparison of Iceland scallop size distributions obtained from a camera based autonomous underwater vehicle and dredge survey.

    Science.gov (United States)

    Singh, Warsha; Örnólfsdóttir, Erla B; Stefansson, Gunnar

    2014-01-01

    An approach is developed to estimate size of Iceland scallop shells from AUV photos. A small-scale camera based AUV survey of Iceland scallops was conducted at a defined site off West Iceland. Prior to height estimation of the identified shells, the distortions introduced by the vehicle orientation and the camera lens were corrected. The average AUV pitch and roll was 1.3 and 2.3 deg that resulted in underwater, representing the inherent lens distortion. The predicted shell heights were scaled for the distance from the bottom at which the photos were taken. This approach was validated by height estimation of scallops of known sizes. An underestimation of approximately 0.5 cm was seen, which could be attributed to pixel error, where each pixel represented 0.24 x 0.27 cm. After correcting for this difference the estimated heights ranged from 3.8-9.3 cm. A comparison of the height-distribution from a small-scale dredge survey carried out in the vicinity showed non-overlapping peaks in size distribution, with scallops of a broader size range visible in the AUV survey. Further investigations are necessary to evaluate any underlying bias and to validate how representative these surveys are of the true population. The low resolution images made identification of smaller scallops difficult. Overall, the observations of very few small scallops in both surveys could be attributed to low recruitment levels in the recent years due to the known scallop parasite outbreak in the region. PMID:25303243

  10. A small-scale comparison of Iceland scallop size distributions obtained from a camera based autonomous underwater vehicle and dredge survey.

    Directory of Open Access Journals (Sweden)

    Warsha Singh

    Full Text Available An approach is developed to estimate size of Iceland scallop shells from AUV photos. A small-scale camera based AUV survey of Iceland scallops was conducted at a defined site off West Iceland. Prior to height estimation of the identified shells, the distortions introduced by the vehicle orientation and the camera lens were corrected. The average AUV pitch and roll was 1.3 and 2.3 deg that resulted in <2% error in ground distance rendering these effects negligible. A quadratic polynomial model was identified for lens distortion correction. This model successfully predicted a theoretical grid from a frame photographed underwater, representing the inherent lens distortion. The predicted shell heights were scaled for the distance from the bottom at which the photos were taken. This approach was validated by height estimation of scallops of known sizes. An underestimation of approximately 0.5 cm was seen, which could be attributed to pixel error, where each pixel represented 0.24 x 0.27 cm. After correcting for this difference the estimated heights ranged from 3.8-9.3 cm. A comparison of the height-distribution from a small-scale dredge survey carried out in the vicinity showed non-overlapping peaks in size distribution, with scallops of a broader size range visible in the AUV survey. Further investigations are necessary to evaluate any underlying bias and to validate how representative these surveys are of the true population. The low resolution images made identification of smaller scallops difficult. Overall, the observations of very few small scallops in both surveys could be attributed to low recruitment levels in the recent years due to the known scallop parasite outbreak in the region.

  11. QFD-based conceptual design of an autonomous underwater robot

    Directory of Open Access Journals (Sweden)

    Thip Pasawang

    2015-12-01

    Full Text Available Autonomous underwater robots in the past few years have been designed according to the individual concepts and experiences of the researchers. To design a robot, which meets all the requirements of potential users, is an advanced work. Hence, a systematic design method that could include users’ preferences and requirements is needed. This paper presents the quality function deployment (QFD technique to design an autonomous underwater robot focusing on the Thai Navy military mission. Important user requirements extracted from the QFD method are the ability to record videos, operating at depth up to 10 meters, the ability to operate remotely with cable and safety concerns related to water leakages. Less important user requirements include beauty, using renewable energy, operating remotely with radio and ability to work during night time. The important design parameters derived from the user requirements are a low cost-controller, an autonomous control algorithm, a compass sensor and vertical gyroscope, and a depth sensor. Of low-importance ranked design parameters include the module design, use clean energy, a low noise electric motor, remote surveillance design, a pressure hull, and a beautiful hull form design. The study results show the feasibility of using QFD techniques to systematically design the autonomous underwater robot to meet user requirements. Mapping between the design and expected parameters and a conceptual drafting design of an autonomous underwater robot are also presented.

  12. DESIGN OPTIMISATION OF AN UNMANNED UNDERWATER VEHICLE

    Directory of Open Access Journals (Sweden)

    FIRDAUS ABDULLAH

    2007-08-01

    Full Text Available The results of fluid flow simulation around an unmanned underwater vehicle (UUV are presented in this paper. The UUV represents a small submarine for underwater search and rescue operation, which suits the local river conditions. The flow simulation was performed with a commercially available computational fluid dynamics package, Star-CD. The effects of the UUV geometry on the velocity and pressure distributions on the UUV surface were discussed for Re=500,000 and 3,000,000. The discussion led to an improved design of the UUV with a smoother velocity profile around the UUV body.

  13. Depth Level Control System using Peripheral Interface Controller for Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Muhamad Fadli Ghani

    2013-01-01

    Full Text Available This research explained on a design and development of an Automatic Depth Control System for underwater vehicle. Definition of underwater vehicle is a robotic sub-sea that is a part of the emerging field of autonomous and unmanned vehicles. This project shows the implementation’s development of an Automatic Depth Control System on a test prototyping vehicle especially involved small-scale and low cost sub-sea robots. The Automatic Depth Control System assembled with mechanical system and module of electronic system for development of a controller.

  14. 多自主水下航行器的有限时间无碰撞协调控制方法%Finite-time collision-free coordination control approach for autonomous underwater vehicles

    Institute of Scientific and Technical Information of China (English)

    袁健; 张文霞; 周忠海

    2012-01-01

    This paper addresses the finite-time cooperative control for autonomous underwater vehicles (AUVs). We present a multi-agent control based finite-time consensus tracking control law. A virtual force is given to achieve the collision-free coordination control among many AUVs by vector composition with the law. Simulation results demonstrate the effectiveness of the proposed control scheme.%研究了多自主水下航行器有限时间协调控制问题,提出一种基于多智能体控制思想的有限时间跟踪一致性控制律。为实现多AUV系统间的避碰,引入一种虚拟力,并且与所设计的有限时间一致性跟踪控制律进行向量合成,构成总的控制律来实现对多AUV系统无碰撞的协调控制。仿真验证了所提出控制策略的有效性。

  15. Magnetic navigation and tracking of underwater vehicles

    Digital Repository Service at National Institute of Oceanography (India)

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

    interference devices (SQUID) and spin exchange relaxation-free (SERF) magnetometers. These ultra-high sensitivity devices open the possibility of exploring in practice some concepts that could not be tested with the technologies previously available. A few... Fluxgate sensor noise intensity σ2 f (1nT)2 SQUIDs sensor noise intensity σ2s (0.1pT) 2 Altitude of the vehicles z 5m Num. of Monte Carlo simulations M 100 Num. of particles in PF N 600 Velocity of underwater vehicles V 1ms−1 Table 2. Methods, sensors...

  16. 子母型自治水下航行器回收控制视景仿真%Visual Simulation for the Recovery Control of Parent-child Autonomous Underwater Vehicles

    Institute of Scientific and Technical Information of China (English)

    吴泽伟; 吴晓锋

    2014-01-01

    基于Visual C++,Vega Prime,Multigen Creator和Matlab对子母型自治水下航行器(Autonomous Underwater Vehicle,AUV)回收控制视景仿真系统进行了开发研究。通过建立子/母AUV的动力学方程,给出了一种基于主-从运动状态同步思想的母AUV自主回收子AUV的控制方案。依据该方案,利用Multigen Creator创建了子/母AUV的实体模型,并由Vega Prime导入模型进行场景配置,以Matlab作为后台对子/母AUV的动力学方程进行实时计算,然后,采用Visual C++平台进行综合集成,得到子母型AUV回收控制视景仿真系统,并通过实例演示进行了验证。%The visual simulation system for the recovery control of parent-child autonomous underwater vehicles (AUV)is studied based on visual C++,vega prime,multigen creator and matlab. First,the dynamical equation of both the parent AUV and the child AUV are given,and then a control scheme for the parent AUV recovering the child AUV is established with the idea of master-slave motional states synchronization. Based on this scheme,the physical models of both parent AUV and child AUV are built and read by Vega Prime such that the simulation scene is deployed,the matlab is used as a back calculator for the dynamical equations of parent AUV and child AUV,then,the vega prime and matlab are integrated by visual C++ such that the whole visual simulation system for the recovery control of parent-child AUV is obtained. The validity of the simulation system is verified by example demonstration.

  17. Secure Cooperation of Autonomous Mobile Sensors Using an Underwater Acoustic Network

    Directory of Open Access Journals (Sweden)

    Gianluca Dini

    2012-02-01

    Full Text Available Methodologies and algorithms are presented for the secure cooperation of a team of autonomous mobile underwater sensors, connected through an acoustic communication network, within surveillance and patrolling applications. In particular, the work proposes a cooperative algorithm in which the mobile underwater sensors (installed on Autonomous Underwater Vehicles—AUVs respond to simple local rules based on the available information to perform the mission and maintain the communication link with the network (behavioral approach. The algorithm is intrinsically robust: with loss of communication among the vehicles the coverage performance (i.e., the mission goal is degraded but not lost. The ensuing form of graceful degradation provides also a reactive measure against Denial of Service. The cooperative algorithm relies on the fact that the available information from the other sensors, though not necessarily complete, is trustworthy. To ensure trustworthiness, a security suite has been designed, specifically oriented to the underwater scenario, and in particular with the goal of reducing the communication overhead introduced by security in terms of number and size of messages. The paper gives implementation details on the integration between the security suite and the cooperative algorithm and provides statistics on the performance of the system as collected during the UAN project sea trial held in Trondheim, Norway, in May 2011.

  18. Some Issues on the Design of a Low-Cost Autonomous Underwater Vehicle with an Intelligent Dynamic Mission Planner for Pipeline and Cable Tracking

    OpenAIRE

    Acosta, Gerardo Gabriel; Curti, Hugo; Ib&#;ñez, Oscar Calvo; Rossi, Silvano

    2009-01-01

    The key aspects of the software and hardware elements design for an AUV prototype have been presented, as a low purchasing and operation cost adaptation of other vehicles over which authors have been working in other projects. In particular, the dynamic mission planner based on an artificial intelligence paradigm showed to be very suitable to be reused in different robots with different inspection missions. This mission planner showed that this approach is able to re-plan the vehicle trajecto...

  19. 自主水下机器人深海热液羽流追踪仿真环境%A Simulation Environment for Deep-Sea Hydrothermal Plume Tracing with Autonomous Underwater Vehicles

    Institute of Scientific and Technical Information of China (English)

    田宇; 李伟; 张艾群

    2012-01-01

    提出用自主水下机器人(autonomous underwater vehicle,AUV)基于仿生行为追踪深海热液羽流,进而快速、精确定位海底热液喷口;并针对AUV追踪深海热液羽流的仿生控制策略研究需要,设计、实现了一个计算机仿真环境.首先介绍了基于AUV的深海热液羽流追踪和该仿真环境的模块化构成,然后给出了仿真环境中的流场和羽流仿真模块所采用的仿真模型及其高效的数值求解算法,和为便于蒙特卡洛仿真而设置的一组随机初始条件和边界条件,以及介绍了控制系统仿真模块采用的一种基于行为的模块化的AUV控制系统体系结构.该仿真环境体现了AUV追踪热液羽流的仿生控制策略研究的问题复杂性因素,包括流场非均匀和非定常,羽流分布不规则、不连续、空间尺度大,羽流轴线弯曲,以及羽流含有浮力上升部分和包含非守恒示踪物质,并且具有较好的可视化效果.同时,该仿真环境具有较高的计算效率,适合于实时仿真和蒙特卡洛仿真研究.分析和演示表明,该仿真环境满足研究需要,为AUV追踪深海热液羽流的仿生控制策略研究提供了有力的支持.%Abstract: For using an autonomous underwater vehicle (AUV) to localize seafloor hydrothermal vents fast and accurately, a biomimetic approach to hydrothermal plume tracing is proposed. And to support the investigation of AUV's biologically-inspired control strategies, a graphical simulation environment is designed and developed. In this paper, hydrothermal plume tracing with AUVs and the modular architecture of the simulation environment are firstly introduced and described. Then, the modules of hydrothermal plume and flow field in simulation environment are modeled, and the efficient numerical solution algorithms are given. To facilitate Monte Carlo simulation, a set of stochastic initial and boundary conditions are set. And the modular behavior-based AUV control system

  20. Visual SLAM for 3D large-scale seabed acquisition employing underwater vehicles

    OpenAIRE

    Salvi, Joaquim; Petillot, Yvan R.; Batlle, Elisabet

    2008-01-01

    This paper presents a novel technique to align partial 3D reconstructions of the seabed acquired by a stereo camera mounted on an autonomous underwater vehicle. Vehicle localization and seabed mapping is performed simultaneously by means of an Extended Kalman Filter. Passive landmarks are detected on the images and characterized considering 2D and 3D features. Landmarks are re-observed while the robot is navigating and data association becomes easier but robust. Once the survey is completed, ...

  1. Large-scale formation control for autonomous underwater vehicles based on Kalman filtering%基于卡尔曼滤波的自主式水下航行器大尺度编队控制

    Institute of Scientific and Technical Information of China (English)

    袁健; 周忠海; 金光虎; 徐娟; 李俊晓

    2013-01-01

    针对网络环境下环境噪声对自主式水下航行器编队控制的影响,提出一种利用卡尔曼滤波实时估计AUV最优运动状态的编队控制方法。将空间间隔较远的多AUV系统建模为多智能体系统,从大尺度上研究其编队控制问题。为了得到每个AUV速度状态的最优估计值,每个AUV都嵌入一个全局卡尔曼滤波器,利用该全局滤波器进行最优估计从而计算出噪声环境下其自身的最优位置。仿真结果验证了所给出的控制策略的有效性。%Aiming at investigating the influence of environmental noise on autonomous underwater vehicles( AUV) formation control, a formation control for estimating AUV optimal motion states in real time is proposed. We mod-eled multiple AUVs with larger interval in space as a multi-agent system in order to investigate the large-scale for-mation control. Each AUV is embedded with one global Kalman filter to obtain the optimal estimation of each AUV speed states. And thus the optimal position of AUV in a noisy environment can be calculated by the optimal estima-tion with the global filter. Finally, some simulations were demonstrated to show the effectiveness of the proposed for-mation control scheme.

  2. Test and Evaluation of Autonomous Ground Vehicles

    OpenAIRE

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

    2014-01-01

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

  3. Autonomous vehicle control systems for safe crossroads

    OpenAIRE

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

    2011-01-01

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

  4. Underwater robots

    CERN Document Server

    Antonelli, Gianluca

    2014-01-01

    This book, now at the third edition, addresses the main control aspects in underwater manipulation tasks. The mathematical model with significant impact on the control strategy is discussed. The problem of controlling a 6-degrees-of-freedoms autonomous underwater vehicle is deeply investigated and a survey of fault detection/tolerant strategies for unmanned underwater vehicles is provided. Inverse kinematics, dynamic and interaction control for underwater vehicle-manipulator systems are then discussed. The code used to generate most of the numerical simulations is made available and briefly discussed.       

  5. Trajectory Simulation for Underwater Vehicle with Power-Lunched

    Institute of Scientific and Technical Information of China (English)

    Chaoqian Chen; Wei Cao; Cong Wang∗and Yingjie Wei

    2016-01-01

    The motion of combustion gas bubble produced by underwater ignition was developed based on Rayleigh⁃Plesset equation. Combining the bubble motion equation with the underwater launched vehicle motion equation in the longitudinal plane, a trajectory simulation model with power⁃launched was established. The hydrodynamic characteristics of underwater ignition at different depths and the trajectory analysis of the underwater vehicle with power⁃launched were given by simulation. The simulation results have a good agreement with experimental results, and show that the thrust peak caused by underwater ignition and the stable thrust both decrease slightly with the increase of the water depth, and the thrust peak will decline obviously by enlarging the initial radius of gas bubble; the thrust peak generated at the instant of ignition and the low⁃frequency oscillation of the stable thrust have no significant influence on the trajectory of underwater vehicle.

  6. A Small-Scale Comparison of Iceland Scallop Size Distributions Obtained from a Camera Based Autonomous Underwater Vehicle and Dredge Survey

    OpenAIRE

    Singh, Warsha, 1978-; Örnólfsdóttir, Erla B.; Stefansson, Gunnar

    2014-01-01

    An approach is developed to estimate size of Iceland scallop shells from AUV photos. A small-scale camera based AUV survey of Iceland scallops was conducted at a defined site off West Iceland. Prior to height estimation of the identified shells, the distortions introduced by the vehicle orientation and the camera lens were corrected. The average AUV pitch and roll was and deg that resulted in error in ground distance rendering these effects negligible. A quadratic polynomial model was identif...

  7. Decentralized Coordination of Autonomous Vehicles at intersections

    OpenAIRE

    Makarem, Laleh; Gillet, Denis

    2011-01-01

    In this paper, the decentralized coordination of point-mass autonomous vehicles at intersections using navigation functions is considered. As main contribution, the inertia of the vehicles is taken into account to enable on-board energy optimization for crossing. In such a way, heavier vehicles that need more energy and time for acceleration or breaking are given an indirect priority at intersections. The proposed decentralized coordination scheme of autonomous vehicles at intersection is com...

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

    International Nuclear Information System (INIS)

    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)

  9. 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)

  10. Using unmanned underwater vehicles as research platforms in coastal ocean studies

    Science.gov (United States)

    Weilin, Hou; Carder, Kendall L.; Costello, David K.; Keping, Du; Zhishen, Liu

    2003-10-01

    The advantages of using unmanned underwater vehicles in coastal ocean studies are emphasized. Two types of representative vehicles, remotely operated vehicle (ROV) and autonomous underwater vehicle (AUV) from University of South Florida, are discussed. Two individual modular sensor packages designed and tested for these platforms and field measurement results are also presented. The bottom classification and albedo package, BCAP, provides fast and accurate estimates of bottom albedos, along with other parameters such as in-water remotes sensing reflectance. The real-time ocean bottom optical topographer, ROBOT, reveals high-resolution 3-dimentional bottom topography for target identification. Field data and results from recent Coastal Benthic Optical Properties field campaign, 1999 and 2000, are presented. Advantages and limitations of these vehicles and applications of modular sensor packages are compared and discussed.

  11. Using Unmanned Underwater Vehicles as Research Platforms in Coastal Ocean Studies

    Institute of Scientific and Technical Information of China (English)

    HOU Weilin; Kendall L. Carder; David K. Costello; DU Keping; LIU Zhishen

    2003-01-01

    The advantages of using unmanned underwater vehicles in coastal ocean studies are emphasized. Two types of representative vehicles, remotely operated vehicle (ROV) and autonomous underwater vehicle (AUV) from University of South Florida, are discussed. Two individual modular sensor packages designed and tested for these platforms and field measurement results are also presented. The bottom classification and albedo package, BCAP, provides fast and accurate estimates of bottom albedos, along with other parameters such as in-water remote sensing reflectance. The real-time ocean bottom optical topographer, ROBOT, reveals high-resolution 3-dimentional bottom topography for target identification. Field data and results from recent Coastal Benthic Optical Properties field campaign, 1999 and 2000, are presented. Advantages and limitations of these vehicles and applications of modular sensor packages are compared and discussed.

  12. Underwater vehicle sonar self-noise prediction based on genetic algorithms and neural network

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-guang; SHI Zhong-kun

    2006-01-01

    The factors that influence underwater vehicle sonar self-noise are analyzed, and genetic algorithms and a back propagation (BP) neural network are combined to predict underwater vehicle sonar self-noise. The experimental results demonstrate that underwater vehicle sonar self-noise can be predicted accurately by a GA-BP neural network that is based on actual underwater vehicle sonar data.

  13. An Observability Metric for Underwater Vehicle Localization Using Range Measurements

    Directory of Open Access Journals (Sweden)

    Filippo Arrichiello

    2013-11-01

    Full Text Available The paper addresses observability issues related to the general problem of single and multiple Autonomous Underwater Vehicle (AUV localization using only range measurements. While an AUV is submerged, localization devices, such as Global Navigation Satellite Systems, are ineffective, due to the attenuation of electromagnetic waves. AUV localization based on dead reckoning techniques and the use of affordable motion sensor units is also not practical, due to divergence caused by sensor bias and drift. For these reasons, localization systems often build on trilateration algorithms that rely on the measurements of the ranges between an AUV and a set of fixed transponders using acoustic devices. Still, such solutions are often expensive, require cumbersome calibration procedures and only allow for AUV localization in an area that is defined by the geometrical arrangement of the transponders. A viable alternative for AUV localization that has recently come to the fore exploits the use of complementary information on the distance from the AUV to a single transponder, together with information provided by on-board resident motion sensors, such as, for example, depth, velocity and acceleration measurements. This concept can be extended to address the problem of relative localization between two AUVs equipped with acoustic sensors for inter-vehicle range measurements. Motivated by these developments, in this paper, we show that both the problems of absolute localization of a single vehicle and the relative localization of multiple vehicles can be treated using the same mathematical framework, and tailoring concepts of observability derived for nonlinear systems, we analyze how the performance in localization depends on the types of motion imparted to the AUVs. For this effect, we propose a well-defined observability metric and validate its usefulness, both in simulation and by carrying out experimental tests with a real marine vehicle during which the

  14. Design and Implementation of Autonomous Sonar Based Vehicle Robot

    Directory of Open Access Journals (Sweden)

    Muhammad Adil Ansari

    2011-07-01

    Full Text Available Autonomous robots are intelligent machines that are capable of performing desired tasks by themselves, without explicit human control. This paper presents design and implementation of the ASVR (Autonomous Sonar Based Vehicle Robot. ASVR is a microcontroller based, programmable mobile robot that can sense and react to its environment and can work in partially known and unpredictable environments. A novel algorithm based on ultrasonic sensors and simple calculations for real-time obstacle detection and avoidance that is intended for mobile robots is also outlined. Also a novel technique is proposed and implemented for steering referencing of vehicle. The design is implemented in air using ultrasonic sensors but can be adapted using sonar to underwater environments where it has important applications such as deep sea maintenance and reconnaissance tasks. The paper also presents performance results of a prototype developed to prove the design concept.

  15. Morphing hull implementation for unmanned underwater vehicles

    International Nuclear Information System (INIS)

    There has been much interest and work in the area of morphing aircraft since the 1980s. Morphing could also potentially benefit unmanned underwater vehicles (UUVs). The current paper envisions a UUV with an interior pressure hull and a variable diameter outer flexible hull with fuel stored in the annulus between, and presents a mechanism to realize diameter change of the outer hull. The outer hull diameter of UUVs designed for very long endurance/range could be progressively reduced as fuel was consumed, thereby reducing drag and further increasing endurance and range capability. Diameter morphing could also be advantageous for compact storage of UUVs. A prototype is fabricated to represent an axial section of such a morphing diameter UUV. Diameter change is achieved using eight morphing trusses arranged equidistant around the circumference of the representative interior rigid hull. Each morphing truss has a lower rail (attached to the rigid hull) and an upper rail with V-linkages between, at either ends of the rail. Horizontal motion of the feet of the V-linkages (sliding in the lower rail) results in vertical motion of the upper rail which in turn produces diameter change of the outer hull. For the prototype built and tested, a 63% increase in outer diameter from 12.75″ to 20.75″ was achieved. The introduction of a stretched latex representative flexible skin around the outer rails increased actuation force requirement and led to a propensity for the wheel-in-track sliders in the morphing truss to bind. It is anticipated that this could be overcome with higher precision manufacturing. In addition to symmetric actuation of the morphing trusses resulting in diameter change, the paper also shows that with asymmetric actuation the hull cross-section shape can be changed (for example, from a circular section for underwater operation to a V-section for surface operations). (paper)

  16. Morphing hull implementation for unmanned underwater vehicles

    Science.gov (United States)

    Miller, Timothy F.; Gandhi, Farhan; Rufino, Russell J.

    2013-11-01

    There has been much interest and work in the area of morphing aircraft since the 1980s. Morphing could also potentially benefit unmanned underwater vehicles (UUVs). The current paper envisions a UUV with an interior pressure hull and a variable diameter outer flexible hull with fuel stored in the annulus between, and presents a mechanism to realize diameter change of the outer hull. The outer hull diameter of UUVs designed for very long endurance/range could be progressively reduced as fuel was consumed, thereby reducing drag and further increasing endurance and range capability. Diameter morphing could also be advantageous for compact storage of UUVs. A prototype is fabricated to represent an axial section of such a morphing diameter UUV. Diameter change is achieved using eight morphing trusses arranged equidistant around the circumference of the representative interior rigid hull. Each morphing truss has a lower rail (attached to the rigid hull) and an upper rail with V-linkages between, at either ends of the rail. Horizontal motion of the feet of the V-linkages (sliding in the lower rail) results in vertical motion of the upper rail which in turn produces diameter change of the outer hull. For the prototype built and tested, a 63% increase in outer diameter from 12.75″ to 20.75″ was achieved. The introduction of a stretched latex representative flexible skin around the outer rails increased actuation force requirement and led to a propensity for the wheel-in-track sliders in the morphing truss to bind. It is anticipated that this could be overcome with higher precision manufacturing. In addition to symmetric actuation of the morphing trusses resulting in diameter change, the paper also shows that with asymmetric actuation the hull cross-section shape can be changed (for example, from a circular section for underwater operation to a V-section for surface operations).

  17. Strong tracking adaptive Kalman filters for underwater vehicle dead reckoning

    Institute of Scientific and Technical Information of China (English)

    XIAO Kun; FANG Shao-ji; PANG Yong-jie

    2007-01-01

    To improve underwater vehicle dead reckoning, a developed strong tracking adaptive kalman filter is proposed. The filter is improved with an additional adaptive factor and an estimator of measurement noise covariance. Since the magnitude of fading factor is changed adaptively, the tracking ability of the filter is still enhanced in low velocity condition of underwater vehicles. The results of simulation tests prove the presented filter effective.

  18. Current challenges in autonomous vehicle development

    Science.gov (United States)

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

    2006-05-01

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

  19. Semi-Autonomous Vehicle Project

    Science.gov (United States)

    Stewart, Christopher

    2016-01-01

    The primary objective this summer is "evaluating standards for wireless architecture for the internet of things". The Internet of Things is the network of physical objects or "things" embedded with electronics, software, sensors and network connectivity which enables these objects to collect and exchange data and make decisions based on said data. This was accomplished by creating a semi-autonomous vehicle that takes advantage of multiple sensors, cameras, and onboard computers and combined them with a mesh network which enabled communication across large distances with little to no interruption. The mesh network took advantage of what is known as DTN - Disruption Tolerant Networking which according to NASA is the new communications protocol that is "the first step towards interplanetary internet." The use of DTN comes from the fact that it will store information if an interruption in communications is detected and even forward that information via other relays within range so that the data is not lost. This translates well into the project because as the car moves further away from whatever is sending it commands (in this case a joystick), the information can still be forwarded to the car with little to no loss of information thanks to the mesh nodes around the driving area.

  20. Omnidirectional Stereo Vision for Autonomous Vehicles

    OpenAIRE

    Schönbein, Miriam

    2014-01-01

    Environment perception with cameras is an important requirement for many applications for autonomous vehicles and robots. This work presents a stereoscopic omnidirectional camera system for autonomous vehicles which resolves the problem of a limited field of view and provides a 360° panoramic view of the environment. We present a new projection model for these cameras and show that the camera setup overcomes major drawbacks of traditional perspective cameras in many applications.

  1. Visual navigation for an autonomous mobile vehicle

    OpenAIRE

    Peterson, Kevin Robert

    1992-01-01

    Approved for public release; distribution is unlimited Image understanding for a mobile robotic vehicle is an important and complex task for ensuring safe navigation and extended autonomous operations. The goal of this work is to implement a working vision-based navigation control mechanism within a known environment onboard the autonomous mobile vehicle Yamabico-II. Although installing a working hardware system was not accomplished, the image processing, model description, pattern match...

  2. A High Accuracy Hybrid Navigation System for Unmanned Underwater Vehicle

    Science.gov (United States)

    Kumagai, Hideo; Numajima, Toru; Sugimoto, Sueo

    The development of small, light weight, low power navigation system for guidance of both tethered and autonomous Unmanned Underwater Vehicle (UUV) is required in applications such as deep salvage, oil and gas well head and pipe line laying and maintenance, etc. All have stringent position requirements in order to define target locations followings the initial find, minimize search time for return missions, as well as support of autopilot functions. In these applications mainly an accurate Sonar Doppler Velocity Log (DVL) was used for Inertial Navigation System (INS) error corrections. But the settlement of DVL is not affordable to various UUV so that not convenient to low cost and small UUV. In this paper we propose a new algorithm for combining the low cost but highly accurate INS with Water Screw Speed (WSS) of the UUV efficiently. In order to evaluate our algorithm we produced the data acquisition system and after several experimental run, we simulated this algorithm searching the error correlation time and noise variance of these estimations.

  3. Feasible Path Planning for Autonomous Vehicles

    Directory of Open Access Journals (Sweden)

    Vu Trieu Minh

    2014-01-01

    Full Text Available The objective of this paper is to find feasible path planning algorithms for nonholonomic vehicles including flatness, polynomial, and symmetric polynomial trajectories subject to the real vehicle dynamical constraints. Performances of these path planning methods are simulated and compared to evaluate the more realistic and smoother generated trajectories. Results show that the symmetric polynomial algorithm provides the smoothest trajectory. Therefore, this algorithm is recommended for the development of an automatic control for autonomous vehicles.

  4. Depth-Trim Mapping Control of Underwater Vehicle with Fins

    Institute of Scientific and Technical Information of China (English)

    LI Ye; PANG Yong-jie; HUANG Shu-ling; WAN Lei

    2011-01-01

    Underwater vehicle plays an important role in ocean engineering.Depth control by fin is one of the difficulties for underwater vehicle in motion control.Depth control is indirect due to the freedom coupling between trim and axial motion.It includes the method of dynamic analysis and lift-resistance-coefficient experiment and theory algorithm.By considering the current speed and depth deviation,comprehensive interpretation is used in object-planning instruction.Expected depth is transformed into expected trim.Dynamic output fluctuation can be avoided,which is caused by linear mapping of deviation.It is steady and accurate for the motion of controlled underwater vehicles.The feasibility and efficiency of the control method are testified in the pool and natural area for experiments.

  5. Tethered operation of autonomous aerial vehicles to provide extended field of view for autonomous ground vehicles

    OpenAIRE

    Phang, Nyit Sin

    2006-01-01

    This thesis was part of the ongoing research conducted at the Naval Postgraduate School to achieve greater collaboration between heterogeneous autonomous vehicles. The research addresses optimal control issues in the collaboration between an Unmanned Aerial Vehicle (UAV) and Autonomous Ground Vehicles (AGV). The scenario revolves around using the camera onboard the UAV to extend the effective field of view of the AGV. For military operations, this could be helpful in improving security for co...

  6. Collective Modular Underwater Robotic System for Long-Term Autonomous Operation

    DEFF Research Database (Denmark)

    Christensen, David Johan; Andersen, Jens Christian; Blanke, Mogens;

    tools and robots, and recharge their batteries while underwater. These properties will provide the system, when fully developed, with unique capabilities such as ability to adapt robotic morphology and function to the current task and tolerate failures leading to long-term autonomous operations.......This paper provides a brief overview of an underwater robotic system for autonomous inspection in confined offshore underwater structures. The system, which is currently in development, consist of heterogeneous modular robots able to physically dock and communicate with other robots, transport...

  7. Advanced control architecture for autonomous vehicles

    Science.gov (United States)

    Maurer, Markus; Dickmanns, Ernst D.

    1997-06-01

    An advanced control architecture for autonomous vehicles is presented. The hierarchical architecture consists of four levels: a vehicle level, a control level, a rule-based level and a knowledge-based level. A special focus is on forms of internal representation, which have to be chosen adequately for each level. The control scheme is applied to VaMP, a Mercedes passenger car which autonomously performs missions on German freeways. VaMP perceives the environment with its sense of vision and conventional sensors. It controls its actuators for locomotion and attention focusing. Modules for perception, cognition and action are discussed.

  8. Navigation and control of an autonomous vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Simon, A.; Soehnitz, I.; Becker, J.C.; Schumacher, W. [Technical Univ. Braunschweig (Germany). Inst. of Control Engineering

    2000-07-01

    This paper describes the fusion of sensor data for the navigation of an autonomous vehicle as well as two lateral control concepts to track the vehicle along a desired path. The fusion of navigation data is based on information provided by multiple object-detecting sensors. The object data is fused to increase the accuracy and to obtain the vehicle's state from the relative movement w.r.t. the objects. The presented lateral control methods are an LQG/H{sub 2}-design and an input-output linearizing algorithm. These control schemes were both implemented on a test vehicle. (orig.)

  9. Vehicle following controller design for autonomous intelligent vehicles

    Science.gov (United States)

    Chien, C. C.; Lai, M. C.; Mayr, R.

    1994-01-01

    A new vehicle following controller is proposed for autonomous intelligent vehicles. The proposed vehicle following controller not only provides smooth transient maneuvers for unavoidable nonzero initial conditions but also guarantees the asymptotic platoon stability without the availability of feedforward information. Furthermore, the achieved asymptotic platoon stability is shown to be robust to sensor delays and an upper bound for the allowable sensor delays is also provided in this paper.

  10. Simultaneous Mapping and Localisation for Small Military Unmanned Underwater Vehicle

    OpenAIRE

    Arom Hwang; Woojae Seong

    2012-01-01

    Paper proposes a simultaneous localisation and mapping (SLAM) scheme which is applicable to small military unmanned underwater vehicles (UUVs). The SLAM is a process which enables concurrent estimation of the position of UUV and landmarks in the environment through which the vehicle is passing. An unscented Kalman filter (UKF) is utilised to develop a SLAM suitable to nonlinear motion of UUV. A range sonar is used as a sensor to collect the relative position information of the landmark in the...

  11. CFD and FEM Model of an Underwater Vehicle Propeller

    OpenAIRE

    Chruściel Tadeusz; Ciba Ewelina; Dopke Julita

    2014-01-01

    Within the framework of the project for design and optimization of the Remotely Operated Vehicle (ROV), research on its propulsion has been carried out. Te entire project was supported by CFD and FEM calculations taking into account the characteristics of the underwater vehicle. One of the tasks was to optimize the semi-open duct for horizontal propellers, which provided propulsion and controllability in horizontal plane. In order to create a measurable model of this task it was necessary to ...

  12. A Primer on Autonomous Aerial Vehicle Design

    Science.gov (United States)

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

    2015-01-01

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

  13. A Primer on Autonomous Aerial Vehicle Design

    Directory of Open Access Journals (Sweden)

    Hugo H. G. Coppejans

    2015-12-01

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

  14. A Primer on Autonomous Aerial Vehicle Design.

    Science.gov (United States)

    Coppejans, Hugo H G; Myburgh, Herman C

    2015-01-01

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

  15. Study on the long-distance target apperception techniques for underwater vehicles

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The limited physical size for autonomous underwater vehicles (AUV)or unmanned underwater vehicles (UUV)makes it difficult to acquire enough space gain for localizing long-distance targets.A new technique about long-distance target apperception with passive synthetic aperture array for underwater vehicles is presented.First,a synthetic aperture-processing algorithm based on the FFT transform in the beam space(BSSAP)is introduced.Then,the study on the flank array passive long-distance apperception techniques in the frequency scope of 11-18 kHz is implemented from the view of improving array gains,detection probability and augmenting detected range under a certain sea environment.The results show that the BSSAP algorithm can extend the aperture effectively and improve detection probability.Because of the augment of the transmission loss,the detected range has the trend of decline with the increase of frequency under the same target source level.The synthesized array could improve the space gain by nearly 7 dB and SNR is increased by about 5 dB.The detected range is enhanced to nearly 2 km under the condition of 108-118 dB of the target source level for AUV system in measurement interval of nearly 1 s.

  16. AUV Control and Communication using Underwater Acoustic Networks

    OpenAIRE

    Marques, Eduardo R.B.; Pinto, Marques; Kragelund, Sean; Dias, Paulo S.; Madureira, Luis; Sousa, Alexandre; Correia, Marcio; Ferreira, Hugo; Goncalves, Rui; Martins, Richardo; Horner, Douglas P.; Healey, Anthony J.; Goncalves, Gil M.; Sousa, Joao B.

    2007-01-01

    Underwater acoustic networks can be quite effective to establish communication links between autonomous underwater vehicles (AUVs) and other vehicles or control units, enabling complex vehicle applications and control scenarios. A communications and control framework to support the use of underwater acoustic networks and sample application scenarios are described for single and multi-AUV operation.

  17. Development of Algorithms for Approaching and Docking Underwater Vehicle with Underwater Station

    Directory of Open Access Journals (Sweden)

    Gurenko B.V.

    2015-01-01

    Full Text Available Underwater vehicles (UV are widely spread nowadays. Their efficient application requires accompanying base ships or net of stations for technical servicing. Fast and energy-efficient docking is one of the key requirements for trouble-free operation. In this paper authors describe the research and development of algorithms for UV control system that allows docking with underwater station. The process is divided in two steps: moving to docking zone and vehicle positioning of station. First task includes development of path regulator. The proposed one features separation of control channels for simple adjustment and gives best results when multicoupling influence is low. Second task was solved on the basis of UV mathematical model. Developed control values were tested in simulation and proved themselves to be efficient. Authors give results of coordinate changes, control force modifications and deviation of velocity and orientation angles from the required values.

  18. Developments and challenges for autonomous unmanned vehicles

    CERN Document Server

    Finn, Anthony

    2010-01-01

    It is widely anticipated that autonomous vehicles will have a transformational impact on military forces and will play a key role in many future force structures. As a result, many tasks have already been identified that unmanned systems could undertake more readily than humans. However, for this to occur, such systems will need to be agile, versatile, persistent, reliable, survivable and lethal. This will require many of the vehicles 'cognitive' or higher order functions to be more fully developed, whereas to date only the 'component' or physical functions have been successfully automated and

  19. Model Predictive Control of Autonomous Vehicles

    OpenAIRE

    Zanon, Mario; Frasch, Janick V.; Vukov, Milan; Sager, Sebastian; Diehl, Moritz

    2014-01-01

    International audience The control of autonomous vehicles is a challenging task that requires advanced control schemes. Nonlinear Model Predictive Control (NMPC) and Moving Horizon Estimation (MHE) are optimization-based control and estimation techniques that are able to deal with highly nonlinear, constrained, unstable and fast dynamic systems. In this chapter, these techniques are detailed, a descriptive nonlinear model is derived and the performance of the proposed control scheme is dem...

  20. Impact of autonomous vehicles on urban mobility

    OpenAIRE

    Azmat, Muhammad

    2015-01-01

    The urban population is growing at an exponential rate throughout the world leading to the problems related to swift and speedy mobility or issues caused by convectional mobility options. This study illustrates and explores the new ways to transport people specially taking into account the self-driving cars concept and discusses the concept of mobility 4.0 (smart / intelligent mobility) and briefly highlights the technological aspects of autonomous vehicles, adaptation advantages and progress...

  1. Simultaneous Mapping and Localisation for Small Military Unmanned Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Arom Hwang

    2012-07-01

    Full Text Available Paper proposes a simultaneous localisation and mapping (SLAM scheme which is applicable to small military unmanned underwater vehicles (UUVs. The SLAM is a process which enables concurrent estimation of the position of UUV and landmarks in the environment through which the vehicle is passing. An unscented Kalman filter (UKF is utilised to develop a SLAM suitable to nonlinear motion of UUV. A range sonar is used as a sensor to collect the relative position information of the landmark in the environment in which the UUV is navigating. The proposed SLAM scheme was validated through towing tank experiments about two degrees of freedom motion with UUV motion simulator and real range sonar system for small UUV. The results of these experiments showed that proposed SLAM scheme is capable of estimating the position of the UUV and the surrounding objects under real underwater environment.

  2. Sharing the road: the economics of autonomous vehicles

    OpenAIRE

    Lamotte, Raphaël; De Palma, André; GEROLIMINIS, Nikolas

    2016-01-01

    Automated cars are likely to change mobility substantially in the coming years. Much research is developed in engineering, about legal and behavioral issues, but the economics of autonomous vehicle remains an open area. In this paper, we consider a single-bottleneck situation, in which the capacity of the freeway is divided between conventional and autonomous vehicles. Users of conventional vehicles freely choose their departure time from home, while users of autonomous vehicles collaborate w...

  3. Integrating Multiple Autonomous Underwater Vessels, Surface Vessels and Aircraft into Oceanographic Research Vessel Operations

    Science.gov (United States)

    McGillivary, P. A.; Borges de Sousa, J.; Martins, R.; Rajan, K.

    2012-12-01

    Autonomous platforms are increasingly used as components of Integrated Ocean Observing Systems and oceanographic research cruises. Systems deployed can include gliders or propeller-driven autonomous underwater vessels (AUVs), autonomous surface vessels (ASVs), and unmanned aircraft systems (UAS). Prior field campaigns have demonstrated successful communication, sensor data fusion and visualization for studies using gliders and AUVs. However, additional requirements exist for incorporating ASVs and UASs into ship operations. For these systems to be optimally integrated into research vessel data management and operational planning systems involves addressing three key issues: real-time field data availability, platform coordination, and data archiving for later analysis. A fleet of AUVs, ASVs and UAS deployed from a research vessel is best operated as a system integrated with the ship, provided communications among them can be sustained. For this purpose, Disruptive Tolerant Networking (DTN) software protocols for operation in communication-challenged environments help ensure reliable high-bandwidth communications. Additionally, system components need to have considerable onboard autonomy, namely adaptive sampling capabilities using their own onboard sensor data stream analysis. We discuss Oceanographic Decision Support System (ODSS) software currently used for situational awareness and planning onshore, and in the near future event detection and response will be coordinated among multiple vehicles. Results from recent field studies from oceanographic research vessels using AUVs, ASVs and UAS, including the Rapid Environmental Picture (REP-12) cruise, are presented describing methods and results for use of multi-vehicle communication and deliberative control networks, adaptive sampling with single and multiple platforms, issues relating to data management and archiving, and finally challenges that remain in addressing these technological issues. Significantly, the

  4. Kinodynamic Motion Planning for Autonomous Vehicles

    Directory of Open Access Journals (Sweden)

    Jiwung Choi

    2014-06-01

    Full Text Available This article proposes a computationally effective motion planning algorithm for autonomous ground vehicles operating in a semi-structured environment with a mission specified by waypoints, corridor widths and obstacles. The algorithm switches between two kinds of planners, (i static planners and (ii moving obstacle avoidance manoeuvre planners, depending on the mobility of any detected obstacles. While the first is broken down into a path planner and a controller, the second generates a sequence of controls without global path planning. Each subsystem is implemented as follows. The path planner produces an optimal piecewise linear path by applying a variant of cell decomposition and dynamic programming. The piecewise linear path is smoothed by Bézier curves such that the maximum curvatures of the curves are minimized. The controller calculates the highest allowable velocity profile along the path, consistent with the limits on both tangential and radial acceleration and the steering command for the vehicle to track the trajectory using a pure pursuit method. The moving obstacle avoidance manoeuvre produces a sequence of time-optimal local velocities, by minimizing the cost as determined by the safety of the current velocity against obstacles in the velocity obstacle paradigm and the deviation of the current velocity relative to the desired velocity, to satisfy the waypoint constraint. The algorithms are shown to be robust and computationally efficient, and to demonstrate a viable methodology for autonomous vehicle control in the presence of unknown obstacles.

  5. Visual measurement estimation for autonomous vehicle navigation

    Science.gov (United States)

    Campos, Mario F.; Chaimowicz, Luiz

    1999-07-01

    The autonomous navigation of a mobile vehicle can be described as the task it undertakes to move itself in the environment through a series of positions based on information based on information gathered by its sensors. In order to accomplish this task, the vehicle has to cope with two main subtasks namely obstacle avoidance and self localization. The latter implies in the ability to determine its position and orientation with respect to the environment. This work describes a simple but efficient method that performs pose estimation for a mobile vehicle based on visual information from artificial landmarks using a sequence of frames from an uncalibrated camera. The landmark is segmented from image sequences and the vehicle's localization is computed using landmark geometric properties and vehicle's motion vector. This methodology can be easily extended to be used by different types of mobile agents. One of the key advantages is that it is computationally, efficient making it suitable for real time navigation. Experiments conducted with a Nomad 200 mobile robot equipped with a color camera systems have shown the method to be repeatable and very robust to noise. Visual measurements were compared with readings for other on-board sensors such as ultrasound with excellent consistency.

  6. Research of Algorithms for Approaching and Docking Underwater Vehicle with Underwater Station

    Directory of Open Access Journals (Sweden)

    Pshikhopov Vyacheslav

    2015-01-01

    Full Text Available Authors consider problem of maintenance and service of underwater vehicles. Usually, underwater station or accompanying ship is required for such operations. Docking is one of the most difficult tasks on the vehicle path from the outer space to the servicing bay. Algorithms allowing docking were presented in the earlier paper, and in this paper authors prove their stability. Movement control is based upon the path regulator. The stability of the closed-loop system according to Liapunov with the given control and limitations is proven. Equations, showing that vehicle will complete the positioning task with account to given limitations and staying stable are given. The criterion for switching movement and “positioning to point” algorithms is proposed. Achievement of the developed criterion was researched theoretically and in computer simulation. Experiments provide deviation of actual coordinates and velocity from the required ones and proved that achieving of criterion is enough to claim that system will be stable while performing algorithms with limitations for controls.

  7. CFD and FEM Model of an Underwater Vehicle Propeller

    Directory of Open Access Journals (Sweden)

    Chruściel Tadeusz

    2014-10-01

    Full Text Available Within the framework of the project for design and optimization of the Remotely Operated Vehicle (ROV, research on its propulsion has been carried out. Te entire project was supported by CFD and FEM calculations taking into account the characteristics of the underwater vehicle. One of the tasks was to optimize the semi-open duct for horizontal propellers, which provided propulsion and controllability in horizontal plane. In order to create a measurable model of this task it was necessary to analyze numerical methodology of propeller design, along with the structure of a propellers with nozzles and contra-rotating propellers. It was confronted with theoretical solutions which included running of the analyzed propeller near an underwater vehicle. Also preliminary qualitative analyses of a simplified system with contra-rotating propellers and a semi-open duct were carried out. Te obtained results enabled to make a decision about the ROVs duct form. Te rapid prototyping SLS (Selective Laser Sintering method was used to fabricate a physical model of the propeller. As a consequence of this, it was necessary to verify the FEM model of the propeller, which based on the load obtained from the CFD model. Te article contains characteristics of the examined ROV, a theoretical basis of propeller design for the analyzed cases, and the results of CFD and FEM simulations.

  8. Communications and Control for Enhanced Autonomy in Underwater Vehicles for Deep Oceanographic Research

    Science.gov (United States)

    Jakuba, M.; Kinsey, J. C.; Yoerger, D. R.; Whitcomb, L. L.; Camilli, R.; Murphy, C.; Bowen, A.; German, C. R.

    2010-12-01

    NASA’s Astrobiology Science and Technology for Exploring Planets (ASTEP) program is a science-driven program to produce advances in scientific and technological capabilities for planetary exploration. Oceanographic robotic vehicles and planetary exploration robots have proven to be highly effective scientific tools for performing scientific research in remote, extreme, and hostile environments that preclude direct human presence. In both domains, the planets and the world’s oceans, human oversight of remote robotic exploration can dramatically enhance scientific return in comparison to purely pre-planned missions by combining the perception, intelligence, and domain knowledge of the human operators with the super-human physical and sensory capabilities of robots. The degree of human oversight, however, is restricted in sea and space by physical limits on the bandwidth and time delay of communications between human operators and remote robotic platforms. Enhanced robotic autonomy can alleviate this obstacle. We present a communications and control architecture for underwater oceanographic robot vehicles that has permitted us to introduce elements of enhanced autonomy into operations with the Woods Hole Oceanographic Institution's Autonomous Underwater Vehicles (AUVs) Nereus and Sentry. Our architecture is designed to facilitate: (1) autonomous distillation of scientific data and transmission of salient synopses from the remote vehicle to its human operators; (2) high-level near real-time human supervision and control of mission programming; (3) semi-supervised learning of environmental models for enhanced survey and search mission effectiveness. Specific capabilities our group has demonstrated include selective data delivery via acoustic link; near real-time reprogramming of vehicle mission programs during otherwise preplanned dives; and validation of autonomous decision-making processes with human-supervision. These elements have been recently demonstrated

  9. An Autonomous Underwater Recorder Based on a Single Board Computer.

    Directory of Open Access Journals (Sweden)

    Manuel Caldas-Morgan

    Full Text Available As industrial activities continue to grow on the Brazilian coast, underwater sound measurements are becoming of great scientific importance as they are essential to evaluate the impact of these activities on local ecosystems. In this context, the use of commercial underwater recorders is not always the most feasible alternative, due to their high cost and lack of flexibility. Design and construction of more affordable alternatives from scratch can become complex because it requires profound knowledge in areas such as electronics and low-level programming. With the aim of providing a solution; a well succeeded model of a highly flexible, low-cost alternative to commercial recorders was built based on a Raspberry Pi single board computer. A properly working prototype was assembled and it demonstrated adequate performance levels in all tested situations. The prototype was equipped with a power management module which was thoroughly evaluated. It is estimated that it will allow for great battery savings on long-term scheduled recordings. The underwater recording device was successfully deployed at selected locations along the Brazilian coast, where it adequately recorded animal and manmade acoustic events, among others. Although power consumption may not be as efficient as that of commercial and/or micro-processed solutions, the advantage offered by the proposed device is its high customizability, lower development time and inherently, its cost.

  10. An Autonomous Underwater Recorder Based on a Single Board Computer.

    Science.gov (United States)

    Caldas-Morgan, Manuel; Alvarez-Rosario, Alexander; Rodrigues Padovese, Linilson

    2015-01-01

    As industrial activities continue to grow on the Brazilian coast, underwater sound measurements are becoming of great scientific importance as they are essential to evaluate the impact of these activities on local ecosystems. In this context, the use of commercial underwater recorders is not always the most feasible alternative, due to their high cost and lack of flexibility. Design and construction of more affordable alternatives from scratch can become complex because it requires profound knowledge in areas such as electronics and low-level programming. With the aim of providing a solution; a well succeeded model of a highly flexible, low-cost alternative to commercial recorders was built based on a Raspberry Pi single board computer. A properly working prototype was assembled and it demonstrated adequate performance levels in all tested situations. The prototype was equipped with a power management module which was thoroughly evaluated. It is estimated that it will allow for great battery savings on long-term scheduled recordings. The underwater recording device was successfully deployed at selected locations along the Brazilian coast, where it adequately recorded animal and manmade acoustic events, among others. Although power consumption may not be as efficient as that of commercial and/or micro-processed solutions, the advantage offered by the proposed device is its high customizability, lower development time and inherently, its cost. PMID:26076479

  11. Path planning strategies for autonomous ground vehicles

    Science.gov (United States)

    Gifford, Kevin Kent

    Several key issues involved with the planning and executing of optimally generated paths for autonomous vehicles are addressed. Two new path planning algorithms are developed, and examined, which effectively minimize replanning as unmapped hazards are encountered. The individual algorithms are compared via extensive simulation. The search strategy results are implemented and tested using the University of Colorado's autonomous vehicle test-bed, RoboCar, and results show the advantages of solving the single-destination all-paths problem for autonomous vehicle path planning. Both path planners implement a graph search methodology incorporating dynamic programming that solves the single-destination shortest-paths problem. Algorithm 1, termed DP for dynamic programming, searches a state space where each state represents a potential vehicle location in a breadth-first fashion expanding from the goal to all potential start locations in the state space. Algorithm 2, termed DP*, couples the heuristic search power of the well-known A* search procedure (Nilsson-80) with the dynamic programming principle applied to graph searching to efficiently make use of overlapping subproblems. DP* is the primary research contribution of the work contained within this thesis. The advantage of solving the single-destination shortest-paths problem is that the entire terrain map is solved in terms of reaching a specified goal. Therefore, if the robot is diverted from the pre-planned path, an alternative path is already computed. The search algorithms are extended to include a probabilistic approach using empirical loss functions to incorporate terrain map uncertainties into the path considering terrain planning process. The results show the importance of considering terrain uncertainty. If the map representation ignores uncertainty by marking any area with less than perfect confidence as unpassable or assigns it the worst case rating, then the paths are longer than intuitively necessary. A

  12. A Proposed Standardized Testing Procedure for Autonomous Ground Vehicles

    OpenAIRE

    Alberi, Thomas James

    2008-01-01

    Development of unmanned vehicles will increase as the need to save lives rises. In both military and civilian applications, humans can be taken out of the loop through the implementation of safe and intelligent autonomous vehicles. Although hardware and software development continue to play a large role in the autonomous vehicle industry, validation of these systems will always be necessary. The ability to test these vehicles thoroughly and efficiently will ensure their proper and flawless...

  13. Simultaneous Mapping and Localisation for Small Military Unmanned Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Arom Hwang

    2012-07-01

    Full Text Available Paper proposes a simultaneous localisation and mapping (SLAM scheme which is applicable to small military unmanned underwater vehicles (UUVs. The SLAM is a process which enables concurrent estimation of the position of UUV and landmarks in the environment through which the vehicle is passing. An unscented Kalman filter (UKF is utilised to develop a SLAM suitable to nonlinear motion of UUV. A range sonar is used as a sensor to collect the relative position information of the landmark in the environment in which the UUV is navigating. The proposed SLAM scheme was validated through towing tank experiments about two degrees of freedom motion with UUV motion simulator and real range sonar system for small UUV. The results of these experiments showed that proposed SLAM scheme is capable of estimating the position of the UUV and the surrounding objects under real underwater environment.Defence Science Journal, 2012, 62(4, pp.223-227, DOI:http://dx.doi.org/10.14429/dsj.62.1002

  14. Robust adaptive control of underwater vehicles: A comparative study

    Directory of Open Access Journals (Sweden)

    Thor I. Fossen

    1996-01-01

    Full Text Available Robust adaptive control of underwater vehicles in 6 DOF is analysed in the context of measurement noise. The performance of the adaptive control laws of Sadegh and Harowitz (1990 and Slotine and Benedetto (1990 are compared. Both these schemes require that all states are measured, that is the velocities and positions in surge, sway, heave, roll, pitch and yaw. However, for underwater vehicles it is difficult to measure the linear velocities whereas angular velocity measurements can be obtained by using a 3 axes angular rate sensor. This problem is addressed by designing a nonlinear observer for linear velocity state estimation. The proposed observer requires that the position and the attitude are measured, e.g. by using a hydroacoustic positioning system for linear positions, two gyros for roll and pitch and a compass for yaw. In addition angular rate measurements will be assumed available from a 3-axes rate sensor or a state estimator. It is also assumed that the measurement rate is limited to 2 Hz for all the sensors. Simulation studies with a 3 DOF AUV model are used to demonstrate the convergence and robustness of the adaptive control laws and the velocity state observer.

  15. Autonomous control of a locomotion vehicle

    International Nuclear Information System (INIS)

    A path planner and an execution system are proposed for autonomous vehicle control. The planner creates a near shortest path avoiding obstacles that are represented by combinations of circles and line segments on a two dimensional map. For realizing real time execution, path search procedures employ a heuristic pruning strategies in selecting a node to expand and in generating successor nodes. Nodes are selected for expansion in order, according to a cost assigned to each node. The cost is mainly evaluated by approximating a path length from the initial node to the goal node. In order to expand a node and to generate successor nodes, a specific search procedure is activated that finds positions avoiding obstacles in the direction of the goal, and creates successor nodes corresponding to the positions. The execution system, utilizing an ultrasonic range finder equipped to the vehicle performs a plan repair against unknown obstacles when echoes from the obstacles are observed. The plan repair is conducted by a map edition and replanning in such a way that new circles representing the echoes are added to the map. Obstacle avoidance tests with a vehicle controlled by microprocessors demonstrate the utility of heuristics just outlined. (author)

  16. General outstanding considerations on legal issues applied to autonomous vehicles

    OpenAIRE

    Martinesco, Andrea; Etgens, Victor H.

    2015-01-01

    International audience Even if there are many differences between the autonomous vehicles and aviation, we have tried to show that the long history of automation in airplanes can be a source of inspiration to understand some legal aspects necessary to allow autonomous cars on the streets. Independent on the technological evolution, the premise of this work is to ask the questions that must be faced if a fatal accident involving an autonomous vehicle occurs. In this sense, criminal issues w...

  17. Nonlinear H∞ Optimal Control Scheme for an Underwater Vehicle with Regional Function Formulation

    Directory of Open Access Journals (Sweden)

    Zool H. Ismail

    2013-01-01

    Full Text Available A conventional region control technique cannot meet the demands for an accurate tracking performance in view of its inability to accommodate highly nonlinear system dynamics, imprecise hydrodynamic coefficients, and external disturbances. In this paper, a robust technique is presented for an Autonomous Underwater Vehicle (AUV with region tracking function. Within this control scheme, nonlinear H∞ and region based control schemes are used. A Lyapunov-like function is presented for stability analysis of the proposed control law. Numerical simulations are presented to demonstrate the performance of the proposed tracking control of the AUV. It is shown that the proposed control law is robust against parameter uncertainties, external disturbances, and nonlinearities and it leads to uniform ultimate boundedness of the region tracking error.

  18. The social dilemma of autonomous vehicles.

    Science.gov (United States)

    Bonnefon, Jean-François; Shariff, Azim; Rahwan, Iyad

    2016-06-24

    Autonomous vehicles (AVs) should reduce traffic accidents, but they will sometimes have to choose between two evils, such as running over pedestrians or sacrificing themselves and their passenger to save the pedestrians. Defining the algorithms that will help AVs make these moral decisions is a formidable challenge. We found that participants in six Amazon Mechanical Turk studies approved of utilitarian AVs (that is, AVs that sacrifice their passengers for the greater good) and would like others to buy them, but they would themselves prefer to ride in AVs that protect their passengers at all costs. The study participants disapprove of enforcing utilitarian regulations for AVs and would be less willing to buy such an AV. Accordingly, regulating for utilitarian algorithms may paradoxically increase casualties by postponing the adoption of a safer technology. PMID:27339987

  19. TRIGA-III research reactor pool inspection using an underwater vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Song, T. K.; Lee, J. R.; Kim, S. H.; Yoon, J. S.; Lee, B. J. [KAERI, Taejon (Korea, Republic of)

    1999-10-01

    For the inspection of radioactivity at the nuclear reactor and spent fuel storage pool, an underwater vehicle system has been developed. This underwater vehicle is navigated freely by five thruster which are controlled by developed control system and has a faculty of radiation detection at the inner wall and special point in pool using the radiation detector which is attached to the bottom of the vehicle. In this paper, the developed underwater vehicle and its components are described in detail. Also, the field test result in TRIGA-III research reactor pool is described.

  20. 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.

  1. Simultaneous Localization and Mapping with Iterative Sparse Extended Information Filter for Autonomous Vehicles

    Directory of Open Access Journals (Sweden)

    Bo He

    2015-08-01

    Full Text Available In this paper, a novel iterative sparse extended information filter (ISEIF was proposed to solve the simultaneous localization and mapping problem (SLAM, which is very crucial for autonomous vehicles. The proposed algorithm solves the measurement update equations with iterative methods adaptively to reduce linearization errors. With the scalability advantage being kept, the consistency and accuracy of SEIF is improved. Simulations and practical experiments were carried out with both a land car benchmark and an autonomous underwater vehicle. Comparisons between iterative SEIF (ISEIF, standard EKF and SEIF are presented. All of the results convincingly show that ISEIF yields more consistent and accurate estimates compared to SEIF and preserves the scalability advantage over EKF, as well.

  2. Simultaneous Localization and Mapping with Iterative Sparse Extended Information Filter for Autonomous Vehicles.

    Science.gov (United States)

    He, Bo; Liu, Yang; Dong, Diya; Shen, Yue; Yan, Tianhong; Nian, Rui

    2015-01-01

    In this paper, a novel iterative sparse extended information filter (ISEIF) was proposed to solve the simultaneous localization and mapping problem (SLAM), which is very crucial for autonomous vehicles. The proposed algorithm solves the measurement update equations with iterative methods adaptively to reduce linearization errors. With the scalability advantage being kept, the consistency and accuracy of SEIF is improved. Simulations and practical experiments were carried out with both a land car benchmark and an autonomous underwater vehicle. Comparisons between iterative SEIF (ISEIF), standard EKF and SEIF are presented. All of the results convincingly show that ISEIF yields more consistent and accurate estimates compared to SEIF and preserves the scalability advantage over EKF, as well. PMID:26287194

  3. Cartography For Cooperative Manoeuvres With Autonomous Land Vehicles

    OpenAIRE

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

    2011-01-01

    International audience This article presents a cartographic system to facilitate cooperative manoeuvres among autonomous vehicles in a well-known environment. The main objective is to design an extended cartographic system to help in the navigation of autonomous vehicles. This system has to allow the vehicles not only to access the reference points needed for navigation, but also noticeable information such as the location and type of traffic signals, the proximity to a crossing, the stree...

  4. Path Following of Autonomous Vehicle in 2D Space Using Multivariable Sliding Mode Control

    Directory of Open Access Journals (Sweden)

    Daxiong Ji

    2014-01-01

    Full Text Available A solution to the path following problem for underactuated autonomous vehicles in the presence of possibly large modeling parametric uncertainty is proposed. For a general class of vehicles moving in 2D space, we demonstrated a path following control law based on multiple variable sliding mode that yields global boundedness and convergence of the position tracking error to a small neighborhood and robustness to parametric modeling uncertainty. An error integration element is added into the “tanh” function of the traditional sliding mode control. We illustrated our results in the context of the vehicle control applications that an underwater vehicle moves along with the desired paths in 2D space. Simulations show that the control objectives were accomplished.

  5. Perancangan Sistem Pengaturan Kestabilan Autonomous Underwater (AUV untuk Gerak Lateral Menggunakan Sliding Mode Control (SMC

    Directory of Open Access Journals (Sweden)

    Septian Ainur Rofiq

    2014-03-01

    Full Text Available Autonomous Underwater Vehicle  (AUV merupakan kendaraan bawah air yang dapat bergerak tanpa kendali manusia dan  bermanuver  sesuai  dengan  perintah  yang  diberikan.  AUV memiliki  kemampuan  manuver  yang  dinamis  untuk  melacak lintasan.  Kemampuan  AUV  mencakup  untuk  beroperasi  di daerah  yang  memiliki  dinamika  nonlinear  dan  belum  dapat diprediksi.  Sehingga  dibutuhkan  model  kontrol  berbasis nonlinear  untuk  meningkatkan  kemampuan  dan  misi  AUV. Gerak lateral merupakan salah satu bentuk pergerakan AUV di dalam  air.  AUV  dijaga  agar  tetap  stabil  pada  lintasan  dan kedalaman  yang  dikehendaki.  Pengaturan  kestabilan  AUV  di dalam air pada gerak lateral menggunakan metode Sliding Mode Control  (SMC  diharapkan  agar  respon  yang  diperoleh menyerupai  input  referensi    sistem  linear  orde  satu  dan  tetap stabil  pada  koordinat  lintasan  yang  telah  ditentukan.  Hasil simulasi  menunjukkan  bahwa  SMC  dapat  mempertahankan kestabilan AUV tetap pada lintasan yang telah ditentukan pada 0 radian dengan osilasi maksimal pada lintasan persegi, segitiga dan jajaran genjang sebesar 0,19 radian atau sekitar 10,89 derajat.

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

    OpenAIRE

    YILMAZ, A. E.; B. Gokalp; O. Yildiz

    2009-01-01

    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 o...

  7. An acoustically controlled tetherless underwater vehicle for installation and maintenance of neutrino detectors in the deep ocean

    International Nuclear Information System (INIS)

    The task of installing and servicing high energy neutrino detectors in the deep ocean from a surface support vessel is problematic using conventional tethered systems. An array of multiple detector strings rising 500 m from the ocean floor, and forming a grid with 50 m spacing between the strings, presents a substantial entanglement hazard for equipment cables deployed from the surface. Such tasks may be accomplished with fewer risks using a tetherless underwater remotely operated vehicle that has a local acoustic telemetry link to send control commands and sensor data between the vehicle and a stationary hydrophone suspended above or just outside the perimeter of the work site. The Phase I effort involves the development of an underwater acoustic telemetry link for vehicle control and sensor feedback, the evaluation of video compression methods for real-time acoustic transmission of video through the water, and the defining of local control routines on board the vehicle to allow it to perform certain basic maneuvering tasks autonomously, or to initiate a self-rescue if the acoustic control link should be lost. In Phase II, a prototype tetherless vehicle system will be designed and constructed to demonstrate the ability to install cable interconnections within a detector array at 4 km depth. The same control technology could be used with a larger more powerful vehicle to maneuver the detector strings into desired positions as they are being lowered to the ocean floor

  8. An acoustically controlled tetherless underwater vehicle for installation and maintenance of neutrino detectors in the deep ocean

    Energy Technology Data Exchange (ETDEWEB)

    Ballou, Philip J.

    1997-02-01

    The task of installing and servicing high energy neutrino detectors in the deep ocean from a surface support vessel is problematic using conventional tethered systems. An array of multiple detector strings rising 500 m from the ocean floor, and forming a grid with 50 m spacing between the strings, presents a substantial entanglement hazard for equipment cables deployed from the surface. Such tasks may be accomplished with fewer risks using a tetherless underwater remotely operated vehicle that has a local acoustic telemetry link to send control commands and sensor data between the vehicle and a stationary hydrophone suspended above or just outside the perimeter of the work site. The Phase I effort involves the development of an underwater acoustic telemetry link for vehicle control and sensor feedback, the evaluation of video compression methods for real-time acoustic transmission of video through the water, and the defining of local control routines on board the vehicle to allow it to perform certain basic maneuvering tasks autonomously, or to initiate a self-rescue if the acoustic control link should be lost. In Phase II, a prototype tetherless vehicle system will be designed and constructed to demonstrate the ability to install cable interconnections within a detector array at 4 km depth. The same control technology could be used with a larger more powerful vehicle to maneuver the detector strings into desired positions as they are being lowered to the ocean floor.

  9. An improved self-organizing map method for multiple autonomous underwater vehicle teams in dynamic task assignment and path planning%多个水下机器人动态任务分配和路径规划的信度自组织算法

    Institute of Scientific and Technical Information of China (English)

    朱大奇; 曹翔

    2015-01-01

    针对多个水下机器人(autonomous underwater vehicles,AUVs)动态任务分配和路径规划速度跳变问题,引入栅格信度函数概念,给出一种改进的栅格信度自组织(belief function self-organizing map,BFSOM)算法.目的是控制一组AUV有效地到达所有指定的目标位置,同时保证AUV能够自动的避开障碍物.首先,自组织神经网络(self-organizing map,SOM)算法对多AUV系统进行任务分配,使得每个目标位置都有一个AUV去访问.整个分配过程包括定义SOM神经网络的初始权值、获胜者选择、邻域函数的计算3个步骤;其次,根据栅格信度函数和环境信息更新SOM获胜神经元的权值,使得每个AUV在访问对应目标的过程中能够自动避障并且克服速度跳变,实现AUV自动有效路径规划.最后,通过仿真实验证明了本文提及算法的有效性.

  10. An Integrated Model of Motion, Steering, Positioning and Stabilization of an Unmanned Autonomous Maritime Vehicle

    Directory of Open Access Journals (Sweden)

    Miroslaw Gerigk

    2015-12-01

    Full Text Available In the paper the aim of an interdisciplinary research is presented. The research method is introduced. An object the unmanned autonomous maritime vehicle is briefly described. The key research problem concerns a combined model of the vehicle motion including the loads of lift and hydrodynamic nature. The model takes into account the gravity and displacement forces, resistance and thrust forces, lift and other hydrodynamic forces. One of the major research tasks is to precisely predict the position of the vehicle. To do that an integrated model of acquiring, analyzing and processing the signals is necessary. The processed signals may then be used for the precise steering of the vehicle. The vehicle should be equipped with a stabilization system. Some information on an integrated steering, positioning and stabilization system of the vehicle is briefly presented in the paper. Such the system enables to obtain a fully autonomous vehicle. Some information on the propulsion and underwater energy supply systems are presented in the paper, too.

  11. Thruster Modelling for Underwater Vehicle Using System Identification Method

    Directory of Open Access Journals (Sweden)

    Mohd Shahrieel Mohd Aras

    2013-05-01

    Full Text Available This paper describes a study of thruster modelling for a remotely operated underwater vehicle (ROV by system identification using Microbox 2000/2000C. Microbox 2000/2000C is an XPC target machine device to interface between an ROV thruster with the MATLAB 2009 software. In this project, a model of the thruster will be developed first so that the system identification toolbox in MATLAB can be used. This project also presents a comparison of mathematical and empirical modelling. The experiments were carried out by using a mini compressor as a dummy depth pressure applied to a pressure sensor. The thruster model will thrust and submerge until it reaches a set point and maintain the set point depth. The depth was based on pressure sensor measurement. A conventional proportional controller was used in this project and the results gathered justified its selection.

  12. Numerical Simulation for Ventilated Supercavitation High Speed Underwater Vehicle

    Institute of Scientific and Technical Information of China (English)

    YANG Wu-gang; YANG Zhen-cai; CHU Yan; DENG Qiu-xia; LI Ya-rong; ZHANG Yu-wen

    2009-01-01

    Supercavitation is a revolutionary technique to achieve high drag reduction for underwater vehicle. It can help us to break through the conventional speed barrier. This article presents a numerical algorithm for ventilated supercavitation flow field based on mixture multiphase flow model, briefs the calculation results and compares them with that tested in high-speed water tunnel and towing tank. The mathematical model, its numerical calculation method, computational region and boundary conditions are discussed in detail. Some pertinent nondimensional parameters about the ventilated supercavitation, such as geometrical configuration of supercavity, drag coefficient and ventilation rate are investigated. Reynolds number is selected to predict gas ventilation rate instead of Froude number. Finally, based on the test and simulation results, a semi-empirical formula of the ventilation rate estimation suitable for different conical angle caritators is proposed.

  13. Application of visual servoing to the dynamic positioning of an underwater vehicle

    OpenAIRE

    Lots, Jean-François

    2002-01-01

    Conventional underwater sensors are not well suited to the task of aiding unmanned underwater vehicles to hover. These sensors suffer from several drawbacks such as low sampling rates, low resolution, complexity of operations, drift and cost. Underwatervideo cameras, however, can provide local measurements of position with respect to a local object. Underwater vision presents several challenges: it suffers from a limited range and poor visibility conditions. Besides, recovering motion fromima...

  14. A study of autonomous docking with an AUV using intelligent controls

    OpenAIRE

    Jantapremjit, Pakpong; Wilson, P.A.; Murphy, Alan J.

    2006-01-01

    Autonomous docking using underwater vehicles will play an important role in long-term underwater explorations and surveys. The autonomous docking mission for an autonomous underwater vehicle at a stationary platform involves a vehicle and a platform matching both position, orientation and velocity. The docking missions therefore require intelligent control systems for precise and soft operations. A study of the sliding mode control and the fuzzy logic controller is pro...

  15. Depth perception camera for autonomous vehicle applications

    Science.gov (United States)

    Kornreich, Philipp

    2013-05-01

    An imager that can measure the distance from each pixel to the point on the object that is in focus at the pixel is described. Since it provides numeric information of the distance from the camera to all points in its field of view it is ideally suited for autonomous vehicle navigation and robotic vision. This eliminates the LIDAR conventionally used for range measurements. The light arriving at a pixel through a convex lens adds constructively only if it comes from the object point in focus at this pixel. The light from all other object points cancels. Thus, the lens selects the point on the object who's range is to be determined. The range measurement is accomplished by short light guides at each pixel. The light guides contain a p - n junction and a pair of contacts along its length. They, too, contain light sensing elements along the length. The device uses ambient light that is only coherent in spherical shell shaped light packets of thickness of one coherence length. Each of the frequency components of the broad band light arriving at a pixel has a phase proportional to the distance from an object point to its image pixel.

  16. Latest Sea-Operations in the Macaronesian region with Unmanned Autonomous Marine Gliding Vehicles

    Science.gov (United States)

    Barrera, Carlos; Lorenzo, Alvaro; Viera, Josue; Morales, Tania; Vega, Daura; Rueda, Maria Jose; Llinas, Octavio

    2013-04-01

    Current advances on key marine technology fields provide nowadays a broad range of autonomous unmanned platforms addressed for an efficient and cost-effective ocean observation, with a suitable level of success in terms of endurance, reliability and useful gathered information. In this context, a multidisciplinary family of unmanned autonomous vehicles addressed to monitor both coastal and open-ocean areas plays a relevant role. During the last month, some of the newest unmanned gliding vehicle technologies have been tested within the context of the Oceanic Platform of the Canary Islands (PLOCAN) in varied operational scenarios aiming different technical and scientific purposes, all of them joined in direct partnership with the company provider and other R&D institutions in some cases. Among others, representative examples in this way are the missions under the name Challenger One, Vulcano and SB02 through surface and underwater gliding vehicles, performed mostly in the surrounding subtropical waters of the ESTOC site observatory in the Canary Islands archipelago. The main gathered operational and scientific results from these missions are presented in this work as a sign of new ocean observing technologies within the framework of the Macaronesian Marine and Maritime Observation Strategy (R3M) and linked with the current European rules programs and projects in this field. Keywords: autonomous vehicle, gliders, R3M, ocean observatory, monitoring, marine robotics, ESTOC,

  17. Underwater robots to safeguard Olympic Games in 2008

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ A small-sized autonomous underwater vehicle(AUV) independently developed and built by CAS researchers has been designated as an underwater guard for the forthcoming Olympic Game in 2008 in Beijing. It has recently been approved by the Olympic Sub-committee of Sailing to be a component of the "underwater safety alert system" of the competition.

  18. Sensor Fault Detection and Diagnosis for autonomous vehicles

    OpenAIRE

    Realpe Miguel; Vintimilla Boris; Vlacic Ljubo

    2015-01-01

    In recent years testing autonomous vehicles on public roads has become a reality. However, before having autonomous vehicles completely accepted on the roads, they have to demonstrate safe operation and reliable interaction with other traffic participants. Furthermore, in real situations and long term operation, there is always the possibility that diverse components may fail. This paper deals with possible sensor faults by defining a federated sensor data fusion architecture. The proposed ar...

  19. Broadband sonar considerations for small underwater vehicle applications

    Science.gov (United States)

    Benjamin, Kim C.

    2003-10-01

    As underwater vehicles become more prevalent, so too does the design and integration of compact broadband sonar arrays. Rather than rely on conventional tonpilz technology, where the bandwidth is governed by the width of the transducer's mechanical resonance, designers must consider other transducer technologies that are better suited to small vehicle packaging constraints. These constraints include operational ruggedness, light weight, conformability, and low cost. This talk advocates the use of 1-3 piezocomposite and discusses the rationale behind such a selection. In going to a wideband material such as a 1-3 piezocomposite, with typical mechanical quality factors (Qm) around 2, the selection of where to place the resonance frequency differs from that of its tonpilz counterpart. For the tonpilz array, the sonar operational bandwidth is totally governed by the resonance response of the array element and is typically limited to approximately its 3-dB or half power points. Relaxor-based ferroelectric materials such as single crystal PMN-PT, which exhibit extremely large electromechanical coupling coefficients, cannot attain 3-dB bandwidths of a decade or more when configured in a tonpilz design. This presentation will discuss a 1-3 piezocomposite-based approach that places mechanical resonance near the upper band edge of an operational bandwidth of 1 decade (10-100 kHz).

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

    Science.gov (United States)

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

    1994-01-01

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

  1. Maneuvering hydrodynamics of fish and small underwater vehicles.

    Science.gov (United States)

    Bandyopadhyay, Promode R

    2002-02-01

    The understanding of fish maneuvering and its application to underwater rigid bodies are considered. The goal is to gain insight into stealth. The recent progress made in NUWC is reviewed. Fish morphology suggests that control fins for maneuverability have unique scalar relationships irrespective of their speed type. Maneuvering experiments are carried out with fish that are fast yet maneuverable. The gap in maneuverability between fish and small underwater vehicles is quantified. The hydrodynamics of a dorsal fin based brisk maneuvering device and a dual flapping foil device, as applied to rigid cylindrical bodies, are described. The role of pectoral wings in maneuvering and station keeping near surface waves is discussed. A pendulum model of dolphin swimming is presented to show that body length and tail flapping frequency are related. For nearly neutrally buoyant bodies, Froude number and maneuverability are related. Analysis of measurements indicates that the Strouhal number of dolphins is a constant. The mechanism of discrete and deterministic vortex shedding from oscillating control surfaces has the property of large amplitude unsteady forcing and an exquisite phase dependence, which makes it inherently amenable to active control for precision maneuvering. Theoretical control studies are carried out to demonstrate the feasibility of maneuverability of biologically inspired bodies under surface waves. The application of fish hydrodynamics to the silencing of propulsors is considered. Two strategies for the reduction of radiated noise are developed. The effects of a reduction of rotational rate are modeled. The active cambering of blades made of digitally programmable artificial muscles, and their thrust enhancement, are demonstrated. Next, wake momentum filling is carried out by artificial muscles at the trailing edge of a stator blade of an upstream stator propulsor, and articulating them like a fish tail. A reduction of radiated noise, called blade tonals

  2. Resource-Optimal Planning For An Autonomous Planetary Vehicle

    CERN Document Server

    Della Penna, Giuseppe; Magazzeni, Daniele; Mercorio, Fabio; 10.5121/ijaia.2010.1302

    2010-01-01

    Autonomous planetary vehicles, also known as rovers, are small autonomous vehicles equipped with a variety of sensors used to perform exploration and experiments on a planet's surface. Rovers work in a partially unknown environment, with narrow energy/time/movement constraints and, typically, small computational resources that limit the complexity of on-line planning and scheduling, thus they represent a great challenge in the field of autonomous vehicles. Indeed, formal models for such vehicles usually involve hybrid systems with nonlinear dynamics, which are difficult to handle by most of the current planning algorithms and tools. Therefore, when offline planning of the vehicle activities is required, for example for rovers that operate without a continuous Earth supervision, such planning is often performed on simplified models that are not completely realistic. In this paper we show how the UPMurphi model checking based planning tool can be used to generate resource-optimal plans to control the engine of ...

  3. Operator Informational Needs for Multiple Autonomous Small Vehicles

    Science.gov (United States)

    Trujillo, Anna C.; Fan, Henry; Hempley, Lucas E.; Cichella, Venanzio; Puig-Navarro, Javier; Mehdi, Syed Bilal; Cross, Charles D.

    2015-01-01

    With the anticipated explosion of small unmanned aerial vehicles, it is highly likely that operators will be controlling fleets of autonomous vehicles. To fulfill the promise of autonomy, vehicle operators will not be concerned with manual control of the vehicle; instead, they will deal with the overall mission. Furthermore, the one operator to many vehicles is becoming a constant meme with various industries including package delivery, search and rescue, and utility companies. In order for an operator to concurrently control several vehicles, his station must look and behave very differently than the current ground control station instantiations. Furthermore, the vehicle will have to be much more autonomous, especially during non-normal operations, in order to accommodate the knowledge deficit or the information overload of the operator in charge of several vehicles. The expected usage increase of small drones requires presenting the operational information generated by a fleet of heterogeneous autonomous agents to an operator. NASA Langley Research Center's Autonomy Incubator has brought together researchers in various disciplines including controls, trajectory planning, systems engineering, and human factors to develop an integrated system to study autonomy issues. The initial human factors effort is focusing on mission displays that would give an operator the overall status of all autonomous agents involved in the current mission. This paper will discuss the specifics of the mission displays for operators controlling several vehicles.

  4. Propulsive efficiency of a biomorphic pulsed-jet underwater vehicle

    International Nuclear Information System (INIS)

    The effect of the velocity program and duty cycle (StL) on the propulsive efficiency of pulsed-jet propulsion was studied experimentally on a self-propelled, pulsed-jet underwater vehicle, dubbed Robosquid due to the similarity of essential elements of its propulsion system with squid jet propulsion. Robosquid was tested for jet slug length-to-diameter ratios (L/D) in the range 2-6 and StL in the range 0.2-0.6 with jet velocity programs commanded to be triangular or trapezoidal. Digital particle image velocimetry was used for measuring the impulse and energy of jet pulses to calculate the pulsed-jet propulsive efficiency and compare it with an equivalent steady jet system. Robosquid's Reynolds number (Re) based on average vehicle velocity and vehicle diameter ranged between 1300 and 2700 for the conditions tested. The results indicated better propulsive efficiency of the trapezoidal velocity program (up to 20% higher) compared to the triangular velocity program. Also, an increase in the ratio of the pulsed-jet propulsive efficiency to the equivalent steady jet propulsive efficiency (ηP/ηP,ss) was observed as StL increased and L/D decreased. For cases of short L/D and high StL, ηP/ηP,ss was found to be as high as 1.2, indicating better performance of pulsed jets. This result demonstrates a case where propulsion using essential elements of a biological locomotion system can outperform the traditional mechanical system equivalent in terms of efficiency. It was also found that changes in StL had a proportionately larger effect on propulsive efficiency compared to changes in L/D. A simple model is presented to explain the results in terms of the contribution of over-pressure at the nozzle exit plane associated with the formation of vortex rings with each jet pulse.

  5. Thrust producing mechanisms in ray-inspired underwater vehicle propulsion

    Directory of Open Access Journals (Sweden)

    Geng Liu

    2015-01-01

    Full Text Available This paper describes a computational study of the hydrodynamics of a ray-inspired underwater vehicle conducted concurrently with experimental measurements. High-resolution stereo-videos of the vehicle’s fin motions during steady swimming are obtained and used as a foundation for developing a high fidelity geometrical model of the oscillatory fin. A Cartesian grid based immersed boundary solver is used to examine the flow fields produced due to these complex artificial pectoral fin kinematics. Simulations are carried out at a smaller Reynolds number in order to examine the hydrodynamic performance and understand the resultant wake topology. Results show that the vehicle’s fins experience large spanwise inflexion of the distal part as well as moderate chordwise pitching during the oscillatory motion. Most thrust force is generated by the distal part of the fin, and it is highly correlated with the spanwise inflexion. Two sets of inter-connected vortex rings are observed in the wake right behind each fin. Those vortex rings induce strong backward flow jets which are mainly responsible for the fin thrust generation.

  6. An Adaptive UKF Based SLAM Method for Unmanned Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Hongjian Wang

    2013-01-01

    Full Text Available This work proposes an improved unscented Kalman filter (UKF-based simultaneous localization and mapping (SLAM algorithm based on an adaptive unscented Kalman filter (AUKF with a noise statistic estimator. The algorithm solves the issue that conventional UKF-SLAM algorithms have declining accuracy, with divergence occurring when the prior noise statistic is unknown and time-varying. The new SLAM algorithm performs an online estimation of the statistical parameters of unknown system noise by introducing a modified Sage-Husa noise statistic estimator. The algorithm also judges whether the filter is divergent and restrains potential filtering divergence using a covariance matching method. This approach reduces state estimation error, effectively improving navigation accuracy of the SLAM system. A line feature extraction is implemented through a Hough transform based on the ranging sonar model. Test results based on unmanned underwater vehicle (UUV sea trial data indicate that the proposed AUKF-SLAM algorithm is valid and feasible and provides better accuracy than the standard UKF-SLAM system.

  7. Selective submap joining SLAM for autonomous vehicles

    OpenAIRE

    Aulinas Masó, Josep M.

    2011-01-01

    Simultaneous Localization and Mapping (SLAM) do not result in consistent maps of large areas because of gradual increase of the uncertainty for long term missions. In addition, as the size of the map grows the computational cost increases, making SLAM solutions unsuitable for on-line applications. This thesis surveys SLAM approaches paying special attention to those approaches aimed to work on large scenarios. Special focus is given to existing underwater SLAM applications. A tech...

  8. Advancing Autonomous Operations for Deep Space Vehicles

    Science.gov (United States)

    Haddock, Angie T.; Stetson, Howard K.

    2014-01-01

    Starting in Jan 2012, the Advanced Exploration Systems (AES) Autonomous Mission Operations (AMO) Project began to investigate the ability to create and execute "single button" crew initiated autonomous activities [1]. NASA Marshall Space Flight Center (MSFC) designed and built a fluid transfer hardware test-bed to use as a sub-system target for the investigations of intelligent procedures that would command and control a fluid transfer test-bed, would perform self-monitoring during fluid transfers, detect anomalies and faults, isolate the fault and recover the procedures function that was being executed, all without operator intervention. In addition to the development of intelligent procedures, the team is also exploring various methods for autonomous activity execution where a planned timeline of activities are executed autonomously and also the initial analysis of crew procedure development. This paper will detail the development of intelligent procedures for the NASA MSFC Autonomous Fluid Transfer System (AFTS) as well as the autonomous plan execution capabilities being investigated. Manned deep space missions, with extreme communication delays with Earth based assets, presents significant challenges for what the on-board procedure content will encompass as well as the planned execution of the procedures.

  9. An Autonomous Vehicle for Farming Using GPS

    Directory of Open Access Journals (Sweden)

    Neelam Rup Prakash

    2012-06-01

    Full Text Available This paper presents the automatic steering control of farming vehicle using GPS receiver. Automatic steering devices for farming vehicles like tractors, seeding vehicle, weed control vehicle, spraying machine vehicle etc. have the task to relieve the driver from the physical and mental stress of monotonous steering work. Simultaneously, they are intended to help him to exploit machines and farming vehicle closer to their full performance and improve the quality of work. Vehicles frequently have to be steered in and exact straight line and along rows in the farm land.GPS receiver fetches the information of positions (latitude and longitude of the farm land which needs to be cultivated. With the help of GPS and microcontroller (Arm9 we calculate the boundary of farm land, slope of straight line and angle of movement with the help of slope changes. The microcontroller generates the control signals to stepper motor for steering of vehicle.

  10. 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.

  11. Different Control Algorithms for a Platoon of Autonomous Vehicles

    Directory of Open Access Journals (Sweden)

    Zoran Gacovski

    2014-05-01

    Full Text Available This paper presents a concept of platoon movement of autonomous vehicles (smart cars. These vehicles have Adaptive or Advanced cruise control (ACC system also called Intelligent cruise control (ICC or Adaptive Intelligent cruise control (AICC system. The vehicles are suitable to follow other vehicles on desired distance and to be organized in platoons. To perform a research on the control and stability of an AGV (Automated Guided Vehicles string, we have developed a car-following model. To do this, first a single vehicle is modeled and since all cars in the platoon have the same dynamics, the single vehicle model is copied ten times to form model of platoon (string with ten vehicles. To control this string, we have applied equal PID controllers to all vehicles, except the leading vehicle. These controllers try to keep the headway distance as constant as possible and the velocity error between subsequent vehicles - small. For control of vehicle with nonlinear dynamics combi­nation of feedforward control and feedback control approach is used. Feedforward control is based on the inverse model of nominal dynamics of the vehicle, and feedback PID control is designed based on the linearized model of the vehicle. For simulation and analysis of vehicle and platoon of vehicles – we have developed Matlab/Simulink models. Simulation results, discussions and conclusions are given at the end of the paper.

  12. Resource-Optimal Planning For An Autonomous Planetary Vehicle

    Directory of Open Access Journals (Sweden)

    Giuseppe Della Penna

    2010-07-01

    Full Text Available Autonomous planetary vehicles, also known as rovers, are small autonomous vehicles equipped with a variety of sensors used to perform exploration and experiments on a planet’s surface. Rovers work in a partially unknown environment, with narrow energy/time/movement constraints and, typically, small computational resources that limit the complexity of on-line planning and scheduling, thus they represent a great challenge in the field of autonomous vehicles. Indeed, formal models for such vehicles usually involve hybrid systems with nonlinear dynamics, which are difficult to handle by most of the current planning algorithms and tools. Therefore, when offline planning of the vehicle activities is required, for example for rovers that operate without a continuous Earth supervision, such planning is often performed on simplified models that are not completely realistic. In this paper we show how the UPMurphi model checking based planning tool can be used to generate resource-optimal plans to control the engine of an autonomous planetary vehicle, working directly on its hybrid model and taking into account several safety constraints, thus achieving very accurate results.

  13. Vision for Autonomous Vehicles and Probes (Dagstuhl Seminar 15461)

    OpenAIRE

    Bruhn, André; Imiya, Atsushi; Leonardis, Ales; Pajdla, Tomas

    2016-01-01

    The vision-based autonomous driving and navigation of vehicles has a long history. In 2013, Daimler succeeded autonomous driving on a public drive way. Today, the Curiosity mars rover is sending video views from Mars to Earth. Computer vision plays a key role in advanced driver assistance systems (ADAS) as well as in exploratory and service robotics. Continuing topics of interest in computer vision are scene and environmental understanding using single- and multiple-camera systems, which are ...

  14. Autonomous Vehicle Path Planning with Remote Sensing Data

    OpenAIRE

    Dalton, Aaron James

    2008-01-01

    Long range path planning for an autonomous ground vehicle with minimal a-priori data is still very much an open problem. Previous research has demonstrated that least cost paths generated from aerial LIDAR and GIS data could play a role in automatically determining suitable routes over otherwise unknown terrain. However, most of this research has been theoretical. Consequently, there is very little literature the effectiveness of these techniques in plotting paths of an actual autonomous v...

  15. Responsibility for Crashes of Autonomous Vehicles: An Ethical Analysis

    OpenAIRE

    Hevelke, Alexander; Nida-Rümelin, Julian

    2014-01-01

    A number of companies including Google and BMW are currently working on the development of autonomous cars. But if fully autonomous cars are going to drive on our roads, it must be decided who is to be held responsible in case of accidents. This involves not only legal questions, but also moral ones. The first question discussed is whether we should try to design the tort liability for car manufacturers in a way that will help along the development and improvement of autonomous vehicles. In p...

  16. Inertial Navigation and Mapping for Autonomous Vehicles

    OpenAIRE

    Skoglund, Martin

    2014-01-01

    Navigation and mapping in unknown environments is an important building block for increased autonomy of unmanned vehicles, since external positioning systems can be susceptible to interference or simply being inaccessible. Navigation and mapping require signal processing of vehicle sensor data to estimate motion relative to the surrounding environment and to simultaneously estimate various properties of the surrounding environment. Physical models of sensors, vehicle motion and external influ...

  17. 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.

  18. Underwater wireless communication system

    International Nuclear Information System (INIS)

    Underwater communication has a range of applications including remotely operated vehicle (ROV) and autonomous underwater vehicle (AUV) communication and docking in the offshore industry. Current underwater transmission techniques is primarily utilise sound waves for large distance at lower frequencies and the velocity of sound in water is approximately 1500m/s the resultant communications have problems with multi-path propagation and low bandwidth problems. The use of electromagnetic (EM) techniques underwater has largely been overlooked because of the attenuation due to the conductivity of seawater. However, for short range applications, the higher frequencies and much higher velocity can prove advantageous. This paper will outline a project which will utilise recent investigations that demonstrate EM wave propagation up to the MHz frequency range is possible in seawater.

  19. Underwater wireless communication system

    Energy Technology Data Exchange (ETDEWEB)

    Goh, J H; Shaw, A; Al-Shamma' a, A I, E-mail: j.h.goh@2006.ljmu.ac.u [Liverpool John Moores University, General Engineering Research Institute (GERI), RF and Microwave Group, Byrom Street, Liverpool, L3 3AF (United Kingdom)

    2009-07-01

    Underwater communication has a range of applications including remotely operated vehicle (ROV) and autonomous underwater vehicle (AUV) communication and docking in the offshore industry. Current underwater transmission techniques is primarily utilise sound waves for large distance at lower frequencies and the velocity of sound in water is approximately 1500m/s the resultant communications have problems with multi-path propagation and low bandwidth problems. The use of electromagnetic (EM) techniques underwater has largely been overlooked because of the attenuation due to the conductivity of seawater. However, for short range applications, the higher frequencies and much higher velocity can prove advantageous. This paper will outline a project which will utilise recent investigations that demonstrate EM wave propagation up to the MHz frequency range is possible in seawater.

  20. Analysis of movement for unmanned underwater vehicle using a low cost integrated sensor

    Science.gov (United States)

    Aras, Mohd Shahrieel Mohd; Abdullah, Shahrum Shah; Rahman, Ahmad Fadzli Nizam Abdul; Basar, Mohd Farriz; Kassim, Anuar Mohamed; Jaafar, Hazriq Izzuan

    2015-05-01

    This paper presents the development of low cost integrated Smart Sensor for Unmanned Underwater Vehicle (UUV) namely as underwater Remotely Operated Vehicle (ROV). In the underwater industries, the most crucial issues are the sensors that are needed for the underwater task. The sensors that are utilized in this area are quite expensive and sensitive. Every sensors used in the underwater vehicle are not in the form of integrated sensors and most of them based on case to case basis. However, nowadays, a lot of industries are involved in the development of the integrated sensor in order to reduce the production cost as well as to increase accuracies, efficiencies and productivities. Therefore, this research proposes an integrated sensor to be applied in the underwater operations. The integrated sensor is designed based on three goal performances which are; the accuracies; the sensitivities and the cost efficiencies. This integrated sensor is the combination of pressure sensor, inertial measurement unit (IMU), digital compass and temperature sensor that are placed in a waterproof casing. This integrated sensor is targeted to be used to control the movement of ROV to maintain its position called station keeping. The purpose of the station keeping is to ensure the ROV to remain stationary at the desired depth by utilizing the pressure sensor. The experimental studies have been carried out in order to see the responses of each sensor.

  1. A Novel INS and Doppler Sensors Calibration Method for Long Range Underwater Vehicle Navigation

    Directory of Open Access Journals (Sweden)

    Wenqi Wu

    2013-10-01

    Full Text Available Since the drifts of Inertial Navigation System (INS solutions are inevitable and also grow over time, a Doppler Velocity Log (DVL is used to aid the INS to restrain its error growth. Therefore, INS/DVL integration is a common approach for Autonomous Underwater Vehicle (AUV navigation. The parameters including the scale factor of DVL and misalignments between INS and DVL are key factors which limit the accuracy of the INS/DVL integration. In this paper, a novel parameter calibration method is proposed. An iterative implementation of the method is designed to reduce the error caused by INS initial alignment. Furthermore, a simplified INS/DVL integration scheme is employed. The proposed method is evaluated with both river trial and sea trial data sets. Using 0.03°/h(1σ ring laser gyroscopes, 5 × 10−5 g(1σ quartz accelerometers and DVL with accuracy 0.5% V ± 0.5 cm/s, INS/DVL integrated navigation can reach an accuracy of about 1‰ of distance travelled (CEP in a river trial and 2‰ of distance travelled (CEP in a sea trial.

  2. Development of an Autonomous Vehicle for Weed and Crop Registration

    DEFF Research Database (Denmark)

    Pedersen, Tom Søndergaard; Nielsen, Kirsten Mølgaard; Andersen, Palle;

    The extension of information technology and computers on farming tools results in new possibilities for crop/weed handling. In this paper a system using an autonomous field robot (vehicle) able to make images in the field is described. In the recent farming has come to rely on intensive use of...... degree of autonomy. The vehicle is part of an autonomous information system for crop and weed registration in fields which is developed at Aalborg University and The Danish Institute of Agricultural Science. The system consists of the vehicle and a stationary base station as well as a wireless...... solution but at present the image analysis technology does not have the capability for online analysis. An alternative way is to construct a weed map prior to the spraying. In order to avoid damage to the soil a light weight vehicle carrying a camera is an obvious choice. To minimize damage to the crop the...

  3. 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.

  4. Autonomous Vehicle Transportation Using Wireless Technology

    Directory of Open Access Journals (Sweden)

    M.Ragul

    2013-04-01

    Full Text Available This paper illustrates the use of a vehicle in several industries and is capable of reducing extra strenuous and/or time consuming activities of humans. The main concentration of this work was onvehicle navigation, tracking, obstacle detection, weight overload, battery power measuring and also be able to locate the respective service station goods. Vehicle navigation employs RFID technology. TheRFID reader is installed in the vehicle and reads the tags which are placed along its route. Whenever a vehicle reaches a service station it sends a message to the workers. Upon receiving a message, the workers can collect the respective service station goods using RFID. If the wrong goods are taken out of the vehicle, the buzzer gets activated. The obstacle detection can be done by ultrasonic sensors. If any obstacle in the route is detected, the message is sent to the control station of the industry using the GSM module. The load cell is used to indicate the weight overload to the workers. Two batteries have been together utilized to measure the required power by this developed vehicle. As soon as Battery1 becomes dry, the battery2 is made the main source of power and a message is sent to the control station through GSM. The control station having a GSM module receives the message and the result will be displayed in hyper terminal window on the PC (personal computer. The vehicle transportation uses PICmicrocontroller, sensors and wireless technology.

  5. Reactive Planning of Autonomous Vehicles for Traffic Scenarios

    OpenAIRE

    Rahul Kala; Kevin Warwick

    2015-01-01

    Autonomous vehicles operate in real time traffic scenarios and aim to reach their destination from their source in the most efficient manner possible. Research in mobile robotics provides a variety of sophisticated means with which to plan the path of these vehicles. Conversely professional human drivers usually drive using instinctive means, which enables them to reach their goal almost optimally whilst still obeying all traffic laws. In this paper we propose the use of fuzzy logic for novel...

  6. Cooperative Control for Multiple Autonomous Vehicles Using Descriptor Functions

    OpenAIRE

    Marta Niccolini; Lorenzo Pollini; Mario Innocenti

    2014-01-01

    The paper presents a novel methodology for the control management of a swarm of autonomous vehicles. The vehicles, or agents, may have different skills, and be employed for different missions. The methodology is based on the definition of descriptor functions that model the capabilities of the single agent and each task or mission. The swarm motion is controlled by minimizing a suitable norm of the error between agents’ descriptor functions and other descriptor functions which models the enti...

  7. An Investigation of the Clothoid Steering Model for Autonomous Vehicles

    OpenAIRE

    Meidenbauer, Kennneth Richard

    2007-01-01

    The clothoid, also known as the Cornu spiral, is a curve generated by linearly increasing or decreasing curvature as a function of arc length. The clothoid has been widely accepted as a logical curve for transitioning from straight segments to circle arcs in roads and railways, because a vehicle following the curve at constant speed will have a constant change of centripetal acceleration. Clothoids have also been widely adopted in planning potential paths for autonomous vehicle navigation...

  8. Underwater target positioning with a single acoustic sensor

    Digital Repository Service at National Institute of Oceanography (India)

    David, M-S; Pascoal, A.M.; Joaquin, A.

    The availability of reliable underwater positioning systems to localize one or more vehicles simultaneously based on information received on-board a support ship or an autonomous surface vessel is key to the operation of some classes of AUVs...

  9. Observer based output feedback tuning for underwater remotely operated vehicle based on linear quadratic performance

    Science.gov (United States)

    Aras, Mohd Shahrieel Mohd; Abdullah, Shahrum Shah; Kamarudin, Muhammad Nizam; Rahman, Ahmad Fadzli Nizam Abdul; Azis, Fadilah Abd; Jaafar, Hazriq Izzuan

    2015-05-01

    This paper describes the effectiveness of observer-based output feedback for Unmanned Underwater Vehicle (UUV) with Linear Quadratic Regulation (LQR) performance. Tuning of observer parameters is crucial for tracking purpose. Prior to tuning facility, the ranges of observer and LQR parameters are obtained via system output cum error. The validation of this technique using unmanned underwater vehicles called Remotely Operated Vehicle (ROV) modelling helps to improve steady state performance of system response. The ROV modeling is focused for depth control using ROV 1 developed by the Underwater Technology Research Group (UTeRG). The results are showing that this technique improves steady state performances in term of overshoot and settling time of the system response.

  10. Tracking Controller Design for Diving Behavior of an Unmanned Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Yi-Hsiang Tseng

    2013-01-01

    Full Text Available The study has investigated the almost disturbance decoupling problem of nonlinear uncertain control systems via the fuzzy feedback linearization approach. The significant dedication of this paper is to organize a control algorithm such that the closed-loop system is active for given initial condition and bounded tracking trajectory with the input-to-state stability and almost disturbance decoupling performance. This study presents a feedback linearization controller for diving control of an unmanned underwater vehicle. Unmanned underwater vehicle proposes difficult control subject due to its nonlinear dynamics, uncertain models, and the existence of disturbances that are difficult to measure. In general, while investigating the diving dynamics of an unmanned underwater vehicle, the pitch angle is always assumed to be small. This assumption is a strong restricting constraint in many interesting practical applications and will be relaxed in this study.

  11. A design approach for small vision-based autonomous vehicles

    Science.gov (United States)

    Edwards, Barrett B.; Fife, Wade S.; Archibald, James K.; Lee, Dah-Jye; Wilde, Doran K.

    2006-10-01

    This paper describes the design of a small autonomous vehicle based on the Helios computing platform, a custom FPGA-based board capable of supporting on-board vision. Target applications for the Helios computing platform are those that require lightweight equipment and low power consumption. To demonstrate the capabilities of FPGAs in real-time control of autonomous vehicles, a 16 inch long R/C monster truck was outfitted with a Helios board. The platform provided by such a small vehicle is ideal for testing and development. The proof of concept application for this autonomous vehicle was a timed race through an environment with obstacles. Given the size restrictions of the vehicle and its operating environment, the only feasible on-board sensor is a small CMOS camera. The single video feed is therefore the only source of information from the surrounding environment. The image is then segmented and processed by custom logic in the FPGA that also controls direction and speed of the vehicle based on visual input.

  12. Feasible Path Planning for Autonomous Vehicles

    OpenAIRE

    Vu Trieu Minh; John Pumwa

    2014-01-01

    The objective of this paper is to find feasible path planning algorithms for nonholonomic vehicles including flatness, polynomial, and symmetric polynomial trajectories subject to the real vehicle dynamical constraints. Performances of these path planning methods are simulated and compared to evaluate the more realistic and smoother generated trajectories. Results show that the symmetric polynomial algorithm provides the smoothest trajectory. Therefore, this algorithm is recommended for the d...

  13. 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

    2015-01-01

    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. PMID:26307997

  14. Sensor Fault Detection and Diagnosis for autonomous vehicles

    Directory of Open Access Journals (Sweden)

    Realpe Miguel

    2015-01-01

    Full Text Available In recent years testing autonomous vehicles on public roads has become a reality. However, before having autonomous vehicles completely accepted on the roads, they have to demonstrate safe operation and reliable interaction with other traffic participants. Furthermore, in real situations and long term operation, there is always the possibility that diverse components may fail. This paper deals with possible sensor faults by defining a federated sensor data fusion architecture. The proposed architecture is designed to detect obstacles in an autonomous vehicle’s environment while detecting a faulty sensor using SVM models for fault detection and diagnosis. Experimental results using sensor information from the KITTI dataset confirm the feasibility of the proposed architecture to detect soft and hard faults from a particular sensor.

  15. 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.

  16. Three Anecdotes from the DARPA Autonomous Land Vehicle Project

    OpenAIRE

    Shapiro, Daniel G.; Institute for the Study of Learning and Expertise

    2008-01-01

    The DARPA Autonomous Land Vehicle was a 12’ tall, 8-wheeled robot with multiple sensors, tasked to go from point A to point B without human intervention in the hills outside of Denver in c. 1985. This was a large applied research effort that presented many opportunities for unusual experiences.

  17. Development of an Autonomous Vehicle for Weed and Crop Registration

    DEFF Research Database (Denmark)

    Pedersen, Tom Søndergaard; Nielsen, Kirsten Mølgaard; Andersen, Palle;

    free height of the vehicle being developed in this work has been set to 0.5 m. The size and weight of the vehicle implies a power consumption of max 1.5 kW making electrical motors suitable for propulsion and steering. To make the operation affordable the vehicle should be unmanned requiring a high...... degree of autonomy. The vehicle is part of an autonomous information system for crop and weed registration in fields which is developed at Aalborg University and The Danish Institute of Agricultural Science. The system consists of the vehicle and a stationary base station as well as a wireless...... responsible for the construction of the electronic part and the guidance system of the vehicle and the Agricultural Institute is responsible for the mechanical part, the image processing and the route planning. This paper focuses on the control, guidance and navigation system. A prototype platform with the...

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

    International Nuclear Information System (INIS)

    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

  19. Dynamic Curvature Steering Control for Autonomous Vehicle: Performance Analysis

    Science.gov (United States)

    Aizzat Zakaria, Muhammad; Zamzuri, Hairi; Amri Mazlan, Saiful

    2016-02-01

    This paper discusses the design of dynamic curvature steering control for autonomous vehicle. The lateral control and longitudinal control are discussed in this paper. The controller is designed based on the dynamic curvature calculation to estimate the path condition and modify the vehicle speed and steering wheel angle accordingly. In this paper, the simulation results are presented to show the capability of the controller to track the reference path. The controller is able to predict the path and modify the vehicle speed to suit the path condition. The effectiveness of the controller is shown in this paper whereby identical performance is achieved with the benchmark but with extra curvature adaptation capabilites.

  20. Networking Multiple Autonomous Air and Ocean Vehicles for Oceanographic Research and Monitoring

    Science.gov (United States)

    McGillivary, P. A.; Borges de Sousa, J.; Rajan, K.

    2013-12-01

    Autonomous underwater and surface vessels (AUVs and ASVs) are coming into wider use as components of oceanographic research, including ocean observing systems. Unmanned airborne vehicles (UAVs) are now available at modest cost, allowing multiple UAVs to be deployed with multiple AUVs and ASVs. For optimal use good communication and coordination among vehicles is essential. We report on the use of multiple AUVs networked in communication with multiple UAVs. The UAVs are augmented by inferential reasoning software developed at MBARI that allows UAVs to recognize oceanographic fronts and change their navigation and control. This in turn allows UAVs to automatically to map frontal features, as well as to direct AUVs and ASVs to proceed to such features and conduct sampling via onboard sensors to provide validation for airborne mapping. ASVs can also act as data nodes for communication between UAVs and AUVs, as well as collecting data from onboard sensors, while AUVs can sample the water column vertically. This allows more accurate estimation of phytoplankton biomass and productivity, and can be used in conjunction with UAV sampling to determine air-sea flux of gases (e.g. CO2, CH4, DMS) affecting carbon budgets and atmospheric composition. In particular we describe tests in July 2013 conducted off Sesimbra, Portugal in conjunction with the Portuguese Navy by the University of Porto and MBARI with the goal of tracking large fish in the upper water column with coordinated air/surface/underwater measurements. A thermal gradient was observed in the infrared by a low flying UAV, which was used to dispatch an AUV to obtain ground truth to demonstrate the event-response capabilities using such autonomous platforms. Additional field studies in the future will facilitate integration of multiple unmanned systems into research vessel operations. The strength of hardware and software tools described in this study is to permit fundamental oceanographic measurements of both ocean

  1. The study of stereo vision technique for the autonomous vehicle

    Science.gov (United States)

    Li, Pei; Wang, Xi; Wang, Jiang-feng

    2015-08-01

    The stereo vision technology by two or more cameras could recovery 3D information of the field of view. This technology can effectively help the autonomous navigation system of unmanned vehicle to judge the pavement conditions within the field of view, and to measure the obstacles on the road. In this paper, the stereo vision technology in measuring the avoidance of the autonomous vehicle is studied and the key techniques are analyzed and discussed. The system hardware of the system is built and the software is debugged, and finally the measurement effect is explained by the measured data. Experiments show that the 3D reconstruction, within the field of view, can be rebuilt by the stereo vision technology effectively, and provide the basis for pavement condition judgment. Compared with unmanned vehicle navigation radar used in measuring system, the stereo vision system has the advantages of low cost, distance and so on, it has a good application prospect.

  2. 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.

  3. Design, implementation and testing of a common data model supporting autonomous vehicle compatibility and interoperability

    OpenAIRE

    Davis, Duane T.

    2006-01-01

    Current autonomous vehicle interoperability is limited by vehicle-specific data formats and support systems. Until a standardized approach to autonomous vehicle command and control is adopted, true interoperability will remain elusive. This work explores the applicability of a data model supporting arbitrary vehicles using the Extensible Markup Language (XML). An exemplar, the Autonomous Vehicle Command Language (AVCL), encapsulates behavior-scripted mission definition, goalbased mission de...

  4. Broadband vehicle-to-vehicle communication using an extended autonomous cruise control sensor

    OpenAIRE

    Heddebaut, M.; Rioult, J.; GHYS, JP; GRANSART, C; AMBELLOUIS, S

    2005-01-01

    For several years road vehicle autonomous cruise control (ACC) systems as well as anti-collision radar have been developed. Several manufacturers currently sell this equipment. The current generation of ACC sensors only track the first preceding vehicle to deduce its speed and position. These data are then used to compute, manage and optimize a safety distance between vehicles, thus providing some assistance to car drivers. However, in real conditions, to elaborate and update a real time driv...

  5. A relaxed criterion for contraction theory: application to an underwater vehicle observer

    DEFF Research Database (Denmark)

    Jouffroy, Jerome

    conclude when the Jacobian is not uniformly negative definite but fulfils some weaker conditions. Intended as an illustrative example, a nonlinear underwater vehicle observer, which Jacobian is not uniformly negative definite, is presented and proven to be exponentially convergent using the new criterion....

  6. A Priori User Acceptance and the Perceived Driving Pleasure in Semi-autonomous and Autonomous Vehicles

    DEFF Research Database (Denmark)

    Bjørner, Thomas

    concerns about trust, user interactions and legislation, as well as the use of technology when driving on highways. Future studies should use a more substantial theoretical framework and real-life tests for a better understanding of user acceptance of driving automation.......The aim of this minor pilot study is, from a sociological user perspective, to explore a priori user acceptance and the perceived driving pleasure in semi- autonomous and autonomous vehicles. The methods used were 13 in-depth interviews while having participants watch video examples within four...

  7. Ant Colony Based Path Planning Algorithm for Autonomous Robotic Vehicles

    Directory of Open Access Journals (Sweden)

    Yogita Gigras

    2012-11-01

    Full Text Available The requirement of an autonomous robotic vehicles demand highly efficient algorithm as well as software. Today’s advanced computer hardware technology does not provide these types of extensive processing capabilities, so there is still a major space and time limitation for the technologies that are available for autonomous robotic applications. Now days, small to miniature mobile robots are required for investigation, surveillance and hazardous material detection for military and industrial applications. But these small sized robots have limited power capacity as well as memory and processing resources. A number of algorithms exist for producing optimal path for dynamically cost. This paper presents a new ant colony based approach which is helpful in solving path planning problem for autonomous robotic application. The experiment of simulation verified its validity of algorithm in terms of time.

  8. An efficient phased mission reliability analysis for autonomous vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Remenyte-Prescott, R., E-mail: R.Remenyte-Prescott@nottingham.ac.u [Nottingham Transportation Engineering Centre, Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Andrews, J.D. [Nottingham Transportation Engineering Centre, Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Chung, P.W.H. [Department of Computer Science, Loughborough University, Loughborough LE11 3TU (United Kingdom)

    2010-03-15

    Autonomous systems are becoming more commonly used, especially in hazardous situations. Such systems are expected to make their own decisions about future actions when some capabilities degrade due to failures of their subsystems. Such decisions are made without human input, therefore they need to be well-informed in a short time when the situation is analysed and future consequences of the failure are estimated. The future planning of the mission should take account of the likelihood of mission failure. The reliability analysis for autonomous systems can be performed using the methodologies developed for phased mission analysis, where the causes of failure for each phase in the mission can be expressed by fault trees. Unmanned autonomous vehicles (UAVs) are of a particular interest in the aeronautical industry, where it is a long term ambition to operate them routinely in civil airspace. Safety is the main requirement for the UAV operation and the calculation of failure probability of each phase and the overall mission is the topic of this paper. When components or subsystems fail or environmental conditions throughout the mission change, these changes can affect the future mission. The new proposed methodology takes into account the available diagnostics data and is used to predict future capabilities of the UAV in real time. Since this methodology is based on the efficient BDD method, the quickly provided advice can be used in making decisions. When failures occur appropriate actions are required in order to preserve safety of the autonomous vehicle. The overall decision making strategy for autonomous vehicles is explained in this paper. Some limitations of the methodology are discussed and further improvements are presented based on experimental results.

  9. An efficient phased mission reliability analysis for autonomous vehicles

    International Nuclear Information System (INIS)

    Autonomous systems are becoming more commonly used, especially in hazardous situations. Such systems are expected to make their own decisions about future actions when some capabilities degrade due to failures of their subsystems. Such decisions are made without human input, therefore they need to be well-informed in a short time when the situation is analysed and future consequences of the failure are estimated. The future planning of the mission should take account of the likelihood of mission failure. The reliability analysis for autonomous systems can be performed using the methodologies developed for phased mission analysis, where the causes of failure for each phase in the mission can be expressed by fault trees. Unmanned autonomous vehicles (UAVs) are of a particular interest in the aeronautical industry, where it is a long term ambition to operate them routinely in civil airspace. Safety is the main requirement for the UAV operation and the calculation of failure probability of each phase and the overall mission is the topic of this paper. When components or subsystems fail or environmental conditions throughout the mission change, these changes can affect the future mission. The new proposed methodology takes into account the available diagnostics data and is used to predict future capabilities of the UAV in real time. Since this methodology is based on the efficient BDD method, the quickly provided advice can be used in making decisions. When failures occur appropriate actions are required in order to preserve safety of the autonomous vehicle. The overall decision making strategy for autonomous vehicles is explained in this paper. Some limitations of the methodology are discussed and further improvements are presented based on experimental results.

  10. Design of an autonomous lunar construction utility vehicle

    Science.gov (United States)

    1990-01-01

    In order to prepare a site for a lunar base, an autonomously operated construction vehicle is necessary. Discussed here is a Lunar Construction Utility Vehicle (LCUV), which uses interchangeable construction implements. Design of an elastic loop track system has advanced to the testing stage. A standard coupling device has been designed to insure a proper connection between the different construction tools and the LCUV. Autonomous control of the track drive motors was simulated successfully through the use of a joystick and a computer interface. A study of hydrogen-oxygen fuel cells produced estimates of reactant and product requirements and identified multilayer insulation needs. Research on the 100-kW heat rejection system determined that it is necessary to transport the radiator panel on a utility trailer. Extensive logistical support for the 720 hour use cycle requires further study.

  11. Evolution-based path planning and management for autonomous vehicles

    Science.gov (United States)

    Capozzi, Brian Joseph

    2001-07-01

    This dissertation describes an approach to adaptive path planning based on the problem solving capabilities witnessed in nature---namely the influence of natural selection in uncovering solutions to the characteristics of the environment. The competition for survival forces organisms to either respond to changes or risk being evolved out of the population. We demonstrate the applicability of this process to the problem of finding paths for an autonomous vehicle through a number of different static and dynamic environments. In doing so, we develop a number of different ways in which these paths can be modeled for the purposes of evolution. Through analysis and experimentation, we develop and reinforce a set of principles and conditions which must hold for the search process to be successful. Having demonstrated the viability of evolution as a guide for path planning, we discuss implications for on-line, real-time planning for autonomous vehicles.

  12. Nonlinear dynamics of autonomous vehicles with limits on acceleration

    Science.gov (United States)

    Davis, L. C.

    2014-07-01

    The stability of autonomous vehicle platoons with limits on acceleration and deceleration is determined. If the leading-vehicle acceleration remains within the limits, all vehicles in the platoon remain within the limits when the relative-velocity feedback coefficient is equal to the headway time constant [k=1/h]. Furthermore, if the sensitivity α>1/h, no collisions occur. String stability for small perturbations is assumed and the initial condition is taken as the equilibrium state. Other values of k and α that give stability with no collisions are found from simulations. For vehicles with non-negligible mechanical response, simulations indicate that the acceleration-feedback-control gain might have to be dynamically adjusted to obtain optimal performance as the response time changes with engine speed. Stability is demonstrated for some perturbations that cause initial acceleration or deceleration greater than the limits, yet do not cause collisions.

  13. INS integrated motion analysis for autonomous vehicle navigation

    Science.gov (United States)

    Roberts, Barry; Bazakos, Mike

    1991-01-01

    The use of inertial navigation system (INS) measurements to enhance the quality and robustness of motion analysis techniques used for obstacle detection is discussed with particular reference to autonomous vehicle navigation. The approach to obstacle detection used here employs motion analysis of imagery generated by a passive sensor. Motion analysis of imagery obtained during vehicle travel is used to generate range measurements to points within the field of view of the sensor, which can then be used to provide obstacle detection. Results obtained with an INS integrated motion analysis approach are reviewed.

  14. JUSTINA: A platform for autonomous land vehicle research and development

    Science.gov (United States)

    Juhala, Matti

    A platform for autonomous land vehicle research and development was developed. The platform makes it possible to conduct tests in natural surroundings. The platform is based on a small car, which was modified and equipped for computer control. The car is equipped with a controller area network, which makes it possible to use parallel processing. The computer system and the modifications made are described. Programs for basic image processing were written and they are tested in a simple line following application. The programs allow different image processing tasks to be done on a desktop computer using either a recorded video signal or digitized images from natural scenes. Special attention was paid to the camera calibration procedure. A simple vehicle model was created for hardware in the loop testing of image processing and vehicle control algorithms. The model uses artificially produced road images. The vehicle is equipped with a differential Global Positioning System (GPS) navigation system, which was tested on an open field application. This platform is modular and can be easily adapted for different research purposes in autonomous land vehicle development.

  15. On-line trajectory planning for autonomous spraying vehicles

    OpenAIRE

    Urcola, Pablo; Duckett, Tom; Cielniak, Grzegorz

    2014-01-01

    In this paper, we present a new application of on-line trajectory planning for autonomous sprayers. The current generation of these vehicles use automatic controllers to maintain the height of the spraying booms above the crop. However, such systems are typically based on ultrasonic sensors mounted directly on the booms, which limits the response of the controller to changes in the terrain, resulting in a suboptimal spraying process. To overcome these limitations, we propose to use 3D maps...

  16. Target representation on an autonomous vehicle with low level sensors

    OpenAIRE

    Bicho, E.; Mallet, Pierre; Schöner, Gregor

    2000-01-01

    How can low-level autonomous robots with only very simple sensor systems be endowed with cognitive capabilities? Specifically, we consider a system that uses seven infrared sensors and five microphones to avoid obstacles and acquire sound targets. The cognitive abilities of the vehicle consist of representing the direction in which a sound source lies. This representation supports target detection, estimation of target direction, selection of one out of multiple-detected targets, storage of t...

  17. Caroline: An Autonomously Driving Vehicle for Urban Environments

    OpenAIRE

    Rauskolb, Fred W.; Berger, Kai; Lipski, Christian; Magnor, Marcus; Cornelsen, Karsten; Effertz, Jan; Form, Thomas; Graefe, Fabian; Ohl, Sebastian; Schumacher, Walter; Wille, Jörn Marten; Hecker, Peter; Nothdurft, Tobias; Doering, Michael; Homeier, Kai

    2014-01-01

    The 2007 DARPA Urban Challenge afforded the golden opportunity for the Technische Universit\\"at Braunschweig to demonstrate its abilities to develop an autonomously driving vehicle to compete with the world's best competitors. After several stages of qualification, our team CarOLO qualified early for the DARPA Urban Challenge Final Event and was among only eleven teams from initially 89 competitors to compete in the final. We had the ability to work together in a large group of experts, each ...

  18. Robotic reactions: delay-induced patterns in autonomous vehicle systems.

    Science.gov (United States)

    Orosz, Gábor; Moehlis, Jeff; Bullo, Francesco

    2010-02-01

    Fundamental design principles are presented for vehicle systems governed by autonomous cruise control devices. By analyzing the corresponding delay differential equations, it is shown that for any car-following model short-wavelength oscillations can appear due to robotic reaction times, and that there are tradeoffs between the time delay and the control gains. The analytical findings are demonstrated on an optimal velocity model using numerical continuation and numerical simulation. PMID:20365620

  19. An Approach to Simulate Autonomous Vehicles in Urban Traffic Scenarios

    OpenAIRE

    figueiredo, mc; rossetti, rjf; braga, ram; reis, lp

    2009-01-01

    The most common cause of traffic accidents is arguably the driver error due to lack of attention. And it is very unlikely this is going to change soon thanks to increasingly cell-phone usage, in-car entertainment systems, and naturally the more frequent traffic jams in highly populated areas. Autonomous vehicles, such as driverless cars, are a promising approach to decrease traffic accidents, as well as congestions. To test this approach, simulations are a safer, more efficient, and cheaper w...

  20. Autonomous guided vehicles applied to industrial engineering and management studies

    OpenAIRE

    Dias, André; Dias, Nuno; Campos, Daniela; Ferreira, Hugo

    2010-01-01

    This article presents a framework to an Industrial Engineering and Management Science course from School of Management and Industrial Studies using Autonomous Ground Vehicles (AGV) to supply materials to a production line as an experimental setup for the students to acquire knowledge in the production robotics area. The students must be capable to understand and put into good use several concepts that will be of utmost importance in their professional life such as critical decisions regard...

  1. Coordinating Hundreds of Cooperative, Autonomous Vehicles in Warehouses

    OpenAIRE

    Wurman, Peter R.; North Carolina State University; D'Andrea, Raffaello; ETH Zurich; Mountz, Mick; Kiva Systems

    2008-01-01

    The Kiva warehouse-management system creates a new paradigm for pick-pack-and-ship warehouses that significantly improves worker productivity. The Kiva system uses movable storage shelves that can be lifted by small, autonomous robots. By bringing the product to the worker, productivity is increased by a factor of two or more, while simultaneously improving accountability and flexibility. A Kiva installation for a large distribution center may require 500 or more vehicles. As such, the Kiva s...

  2. Robotic reactions: Delay-induced patterns in autonomous vehicle systems

    Science.gov (United States)

    Orosz, Gábor; Moehlis, Jeff; Bullo, Francesco

    2010-02-01

    Fundamental design principles are presented for vehicle systems governed by autonomous cruise control devices. By analyzing the corresponding delay differential equations, it is shown that for any car-following model short-wavelength oscillations can appear due to robotic reaction times, and that there are tradeoffs between the time delay and the control gains. The analytical findings are demonstrated on an optimal velocity model using numerical continuation and numerical simulation.

  3. 3D Road Scene Interpretation for Autonomous Vehicle Driving

    OpenAIRE

    Foresti, Gian Luca; Regazzoni, Carlo

    1999-01-01

    In this paper, the problem of 3D road scene interpretation for autonomous vehicle driving is addressed. In particular, the problems of road detection and obstacle avoidance in outdoor environments are investigated. A set of descriptive primitives (straight and circular line segments) is selected to describe 3D objects which commonly occur in road scenes, e.g., people, cars, trucks, houses, etc. First, these primitives are extracted directly from the input image of the scene, and then are grou...

  4. Automated Search-Based Robustness Testing for Autonomous Vehicle Software

    Directory of Open Access Journals (Sweden)

    Kevin M. Betts

    2016-01-01

    Full Text Available Autonomous systems must successfully operate in complex time-varying spatial environments even when dealing with system faults that may occur during a mission. Consequently, evaluating the robustness, or ability to operate correctly under unexpected conditions, of autonomous vehicle control software is an increasingly important issue in software testing. New methods to automatically generate test cases for robustness testing of autonomous vehicle control software in closed-loop simulation are needed. Search-based testing techniques were used to automatically generate test cases, consisting of initial conditions and fault sequences, intended to challenge the control software more than test cases generated using current methods. Two different search-based testing methods, genetic algorithms and surrogate-based optimization, were used to generate test cases for a simulated unmanned aerial vehicle attempting to fly through an entryway. The effectiveness of the search-based methods in generating challenging test cases was compared to both a truth reference (full combinatorial testing and the method most commonly used today (Monte Carlo testing. The search-based testing techniques demonstrated better performance than Monte Carlo testing for both of the test case generation performance metrics: (1 finding the single most challenging test case and (2 finding the set of fifty test cases with the highest mean degree of challenge.

  5. Experience of the ARGO autonomous vehicle

    Science.gov (United States)

    Bertozzi, Massimo; Broggi, Alberto; Conte, Gianni; Fascioli, Alessandra

    1998-07-01

    This paper presents and discusses the first results obtained by the GOLD (Generic Obstacle and Lane Detection) system as an automatic driver of ARGO. ARGO is a Lancia Thema passenger car equipped with a vision-based system that allows to extract road and environmental information from the acquired scene. By means of stereo vision, obstacles on the road are detected and localized, while the processing of a single monocular image allows to extract the road geometry in front of the vehicle. The generality of the underlying approach allows to detect generic obstacles (without constraints on shape, color, or symmetry) and to detect lane markings even in dark and in strong shadow conditions. The hardware system consists of a PC Pentium 200 Mhz with MMX technology and a frame-grabber board able to acquire 3 b/w images simultaneously; the result of the processing (position of obstacles and geometry of the road) is used to drive an actuator on the steering wheel, while debug information are presented to the user on an on-board monitor and a led-based control panel.

  6. Active-imaging-based underwater navigation

    Science.gov (United States)

    Monnin, David; Schmitt, Gwenaël.; Fischer, Colin; Laurenzis, Martin; Christnacher, Frank

    2015-10-01

    Global navigation satellite systems (GNSS) are widely used for the localization and the navigation of unmanned and remotely operated vehicles (ROV). In contrast to ground or aerial vehicles, GNSS cannot be employed for autonomous underwater vehicles (AUV) without the use of a communication link to the water surface, since satellite signals cannot be received underwater. However, underwater autonomous navigation is still possible using self-localization methods which determines the relative location of an AUV with respect to a reference location using inertial measurement units (IMU), depth sensors and even sometimes radar or sonar imaging. As an alternative or a complementary solution to common underwater reckoning techniques, we present the first results of a feasibility study of an active-imaging-based localization method which uses a range-gated active-imaging system and can yield radiometric and odometric information even in turbid water.

  7. Design and Research on the Two-Joint Mating System of Underwater Vehicle

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhong-lin; WANG Li-quan

    2013-01-01

    In the 21st century,people have come to the era of ocean science and ocean economy.With the development of ocean science and technology and the thorough research on the ocean,underwater mating technique has been widely used in such fields as sunk ship salvage,deep ocean workstation,submarine lifesaving aid and military affairs.In this paper,researches are made home and abroad on mating technology.Two-joint mating system of underwater vehicle is designed including plane system,three-dimensional assembly system and control system in order to increase the capacity of adapting platform obliquity and adopting rotational skirt scheme.It is clear that the system fits the working space of underwater vehicle passageway and there is no interference phenomenon in assembly design.The finite element model of the system shell and the pressurization of the joint are established.The results of the finite element computing and the pressing test are accordant,and thus it can testify that the shell material meet the need of intension and joint pressurization is reliable.Modeling of the control system is accomplished,and simulation and analysis are made,which can provide directions for the controller design of mating system of underwater vehicles.

  8. An algorithm for combining autonomous vehicles and controlled events in driving simulator experiments

    OpenAIRE

    Olstam, Johan; Espié, Stéphane; Mårdh, Selina; Jansson, Jonas; Lundgren, Jan

    2011-01-01

    Autonomous vehicles can be used to create realistic simulations of surrounding vehicles in driving simulators. However, the use of autonomous vehicles makes it difficult to ensure reproducibility between subjects. In this paper, an effort is made to solve the problem by combining autonomous vehicles and controlled events, denoted plays. The aim is to achieve the same initial play conditions for each subject, since the traffic situation around the subject will be dependant upon each subject's ...

  9. Introducing autonomous vehicles in logistics: a review from a broad perspective

    OpenAIRE

    Van Meldert, Bram; De Boeck, Liesje

    2016-01-01

    Vehicle automation technologies are rapidly developing and will be available soon. Businesses in the logistics industry can develop a competitive advantage when effectively adopting this new technology. However, only limited research exists about the impact of autonomous vehicles on the logistics industry. The aim of this paper is to provide a broad introduction to autonomous vehicles, after which the usage and potential consequences of autonomous vehicles in logistics is discusse...

  10. Motion Planning of Autonomous Vehicles on a Dual Carriageway without Speed Lanes

    OpenAIRE

    Rahul Kala; Kevin Warwick

    2015-01-01

    The problem of motion planning of an autonomous vehicle amidst other vehicles on a straight road is considered. Traffic in a number of countries is unorganized, where the vehicles do not move within predefined speed lanes. In this paper, we formulate a mechanism wherein an autonomous vehicle may travel on the “wrong” side in order to overtake a vehicle. Challenges include assessing a possible overtaking opportunity, cooperating with other vehicles, partial driving on the “wrong” side of the r...

  11. Global and local obstacle avoidance technique for an autonomous vehicle

    Science.gov (United States)

    Gray, Keith W.; Saunders, Kevin S.

    1999-07-01

    The Center for Self-Organizing and Intelligent Systems (CSOIS) is engaged in developing autonomous ground vehicles. A significant problem for such vehicles is obstacle detection and avoidance. After studying various methods of detection, a scanning laser system was chosen that can detect objects at a distance of up to thirty feet while traveling between five and ten miles per hour. Once an object is detected, the vehicle must avoid it. The project employs a mission-level path planner that predetermines the path of a vehicle. One avoidance scheme is to inform the path planner of the obstacle and then let it re-plan the path. This is the global approach to the problem, which allows the use of existing software for maneuvering the vehicle. However, replanning is time consuming and lacks knowledge of the entire obstacle. An alternative approach is to use local avoidance, whereby a vehicle determines how to get by an obstacle without help from the path planner. This approach offers faster response without requiring the computing resource of the path planner. The disadvantage is that during local avoidance the vehicle ignores the global map of known obstacles and does not know to turn control back to the path planner if mission efficiency is adversely affected. This paper will describe a method for combining the current global path planner with a local obstacle avoidance technique to efficiently complete required tasks in a partially unknown environment.

  12. Responsibility for crashes of autonomous vehicles: an ethical analysis.

    Science.gov (United States)

    Hevelke, Alexander; Nida-Rümelin, Julian

    2015-06-01

    A number of companies including Google and BMW are currently working on the development of autonomous cars. But if fully autonomous cars are going to drive on our roads, it must be decided who is to be held responsible in case of accidents. This involves not only legal questions, but also moral ones. The first question discussed is whether we should try to design the tort liability for car manufacturers in a way that will help along the development and improvement of autonomous vehicles. In particular, Patrick Lin's concern that any security gain derived from the introduction of autonomous cars would constitute a trade-off in human lives will be addressed. The second question is whether it would be morally permissible to impose liability on the user based on a duty to pay attention to the road and traffic and to intervene when necessary to avoid accidents. Doubts about the moral legitimacy of such a scheme are based on the notion that it is a form of defamation if a person is held to blame for causing the death of another by his inattention if he never had a real chance to intervene. Therefore, the legitimacy of such an approach would depend on the user having an actual chance to do so. The last option discussed in this paper is a system in which a person using an autonomous vehicle has no duty (and possibly no way) of interfering, but is still held (financially, not criminally) responsible for possible accidents. Two ways of doing so are discussed, but only one is judged morally feasible. PMID:25027859

  13. Space imaging infrared optical guidance for autonomous ground vehicle

    Science.gov (United States)

    Akiyama, Akira; Kobayashi, Nobuaki; Mutoh, Eiichiro; Kumagai, Hideo; Yamada, Hirofumi; Ishii, Hiromitsu

    2008-08-01

    We have developed the Space Imaging Infrared Optical Guidance for Autonomous Ground Vehicle based on the uncooled infrared camera and focusing technique to detect the objects to be evaded and to set the drive path. For this purpose we made servomotor drive system to control the focus function of the infrared camera lens. To determine the best focus position we use the auto focus image processing of Daubechies wavelet transform technique with 4 terms. From the determined best focus position we transformed it to the distance of the object. We made the aluminum frame ground vehicle to mount the auto focus infrared unit. Its size is 900mm long and 800mm wide. This vehicle mounted Ackerman front steering system and the rear motor drive system. To confirm the guidance ability of the Space Imaging Infrared Optical Guidance for Autonomous Ground Vehicle we had the experiments for the detection ability of the infrared auto focus unit to the actual car on the road and the roadside wall. As a result the auto focus image processing based on the Daubechies wavelet transform technique detects the best focus image clearly and give the depth of the object from the infrared camera unit.

  14. Sensor-driven area coverage for an autonomous fixed-wing unmanned aerial vehicle.

    Science.gov (United States)

    Paull, Liam; Thibault, Carl; Nagaty, Amr; Seto, Mae; Li, Howard

    2014-09-01

    Area coverage with an onboard sensor is an important task for an unmanned aerial vehicle (UAV) with many applications. Autonomous fixed-wing UAVs are more appropriate for larger scale area surveying since they can cover ground more quickly. However, their non-holonomic dynamics and susceptibility to disturbances make sensor coverage a challenging task. Most previous approaches to area coverage planning are offline and assume that the UAV can follow the planned trajectory exactly. In this paper, this restriction is removed as the aircraft maintains a coverage map based on its actual pose trajectory and makes control decisions based on that map. The aircraft is able to plan paths in situ based on sensor data and an accurate model of the on-board camera used for coverage. An information theoretic approach is used that selects desired headings that maximize the expected information gain over the coverage map. In addition, the branch entropy concept previously developed for autonomous underwater vehicles is extended to UAVs and ensures that the vehicle is able to achieve its global coverage mission. The coverage map over the workspace uses the projective camera model and compares the expected area of the target on the ground and the actual area covered on the ground by each pixel in the image. The camera is mounted on a two-axis gimbal and can either be stabilized or optimized for maximal coverage. Hardware-in-the-loop simulation results and real hardware implementation on a fixed-wing UAV show the effectiveness of the approach. By including the already developed automatic takeoff and landing capabilities, we now have a fully automated and robust platform for performing aerial imagery surveys. PMID:25137689

  15. Autonomous Navigation of Small Uavs Based on Vehicle Dynamic Model

    Science.gov (United States)

    Khaghani, M.; Skaloud, J.

    2016-03-01

    This paper presents a novel approach to autonomous navigation for small UAVs, in which the vehicle dynamic model (VDM) serves as the main process model within the navigation filter. The proposed method significantly increases the accuracy and reliability of autonomous navigation, especially for small UAVs with low-cost IMUs on-board. This is achieved with no extra sensor added to the conventional INS/GNSS setup. This improvement is of special interest in case of GNSS outages, where inertial coasting drifts very quickly. In the proposed architecture, the solution to VDM equations provides the estimate of position, velocity, and attitude, which is updated within the navigation filter based on available observations, such as IMU data or GNSS measurements. The VDM is also fed with the control input to the UAV, which is available within the control/autopilot system. The filter is capable of estimating wind velocity and dynamic model parameters, in addition to navigation states and IMU sensor errors. Monte Carlo simulations reveal major improvements in navigation accuracy compared to conventional INS/GNSS navigation system during the autonomous phase, when satellite signals are not available due to physical obstruction or electromagnetic interference for example. In case of GNSS outages of a few minutes, position and attitude accuracy experiences improvements of orders of magnitude compared to inertial coasting. It means that during such scenario, the position-velocity-attitude (PVA) determination is sufficiently accurate to navigate the UAV to a home position without any signal that depends on vehicle environment.

  16. Distributed flow estimation and closed-loop control of an underwater vehicle with a multi-modal artificial lateral line.

    Science.gov (United States)

    DeVries, Levi; Lagor, Francis D; Lei, Hong; Tan, Xiaobo; Paley, Derek A

    2015-04-01

    Bio-inspired sensing modalities enhance the ability of autonomous vehicles to characterize and respond to their environment. This paper concerns the lateral line of cartilaginous and bony fish, which is sensitive to fluid motion and allows fish to sense oncoming flow and the presence of walls or obstacles. The lateral line consists of two types of sensing modalities: canal neuromasts measure approximate pressure gradients, whereas superficial neuromasts measure local flow velocities. By employing an artificial lateral line, the performance of underwater sensing and navigation strategies is improved in dark, cluttered, or murky environments where traditional sensing modalities may be hindered. This paper presents estimation and control strategies enabling an airfoil-shaped unmanned underwater vehicle to assimilate measurements from a bio-inspired, multi-modal artificial lateral line and estimate flow properties for feedback control. We utilize potential flow theory to model the fluid flow past a foil in a uniform flow and in the presence of an upstream obstacle. We derive theoretically justified nonlinear estimation strategies to estimate the free stream flowspeed, angle of attack, and the relative position of an upstream obstacle. The feedback control strategy uses the estimated flow properties to execute bio-inspired behaviors including rheotaxis (the tendency of fish to orient upstream) and station-holding (the tendency of fish to position behind an upstream obstacle). A robotic prototype outfitted with a multi-modal artificial lateral line composed of ionic polymer metal composite and embedded pressure sensors experimentally demonstrates the distributed flow sensing and closed-loop control strategies. PMID:25807584

  17. Interaction of perception and gaze control in autonomous vehicles

    Science.gov (United States)

    Pellkofer, Martin; Luetzeler, Michael; Dickmanns, Ernst D.

    2001-10-01

    For robust and secure behavior in natural environment an autonomous vehicle needs an elaborate vision sensor as main source of information. The vision sensor must be adaptable to the external situation, the mission, the capabilities of the vehicle and the knowledge about the external world accumulated up to the present time. In the EMS-Vision system, this vision sensor consists of four cameras with different focal lengths mounted on a highly dynamic pan-tilt camera head. Image processing, gaze control and behavior decision interact with each other in a closed loop. The image processing experts specify so-called regions of attention (RoAs) for each object in 3D object coordinates. These RoAs should be visible with a resolution as required by the measurement techniques applied. The behavior decision module specifies the relevance of obstacles like road segments, crossings or landmarks in the situation context. The gaze control unit takes all this information in order to plan, optimize and perform a sequence of smooth pursuits, interrupted by saccades. The sequence with the best information gain is performed. The information gain depends on the relevance of objects or object parts, the duration of smooth pursuit maneuvers, the quality of perception and the number of saccades. The functioning of the EMS-Vision system is demonstrated in a complex and scalable autonomous mission with the UBM test vehicle VAMORS.

  18. Modeling and control of an unmanned underwater vehicle using a mass moving system

    Science.gov (United States)

    Byun, Seung-Woo; Kim, Donghee; Choi, Hyeung-Sik; Kim, Joon-Young

    2015-03-01

    This paper describes the mathematical modeling and control algorithms of an unmanned underwater vehicle (UUV) named Minekiller. This UUV has two longitudinal thrusters, one vertical thruster, and an internal mass moving system, which can control the pitch rate. The UUV is equipped with a movable mass for pitch control. It is different from other common UUVs, in that it can maintain a static pitch angle. The UUV's 6-DOF (Degrees of Freedom) dynamics model is derived from the hydrodynamic forces and moments acting on it. We applied these hydrodynamic coefficients to dynamic modeling for numerical simulations by MATLAB/SIMULINK©. To compare the performance in various cases, we used a PID controller for depth and heading control. Also, the navigation controller can analyze the way-point tracking performance. These simulation results show the performance of the control algorithms and maneuvering performance of the underwater vehicle.

  19. Properties of sound attenuation around a two-dimensional underwater vehicle with a large cavitation number

    Science.gov (United States)

    Ye, Peng-Cheng; Pan, Guang

    2015-06-01

    Due to the high speed of underwater vehicles, cavitation is generated inevitably along with the sound attenuation when the sound signal traverses through the cavity region around the underwater vehicle. The linear wave propagation is studied to obtain the influence of bubbly liquid on the acoustic wave propagation in the cavity region. The sound attenuation coefficient and the sound speed formula of the bubbly liquid are presented. Based on the sound attenuation coefficients with various vapor volume fractions, the attenuation of sound intensity is calculated under large cavitation number conditions. The result shows that the sound intensity attenuation is fairly small in a certain condition. Consequently, the intensity attenuation can be neglected in engineering. Project supported by the National Natural Science Foundation of China (Grant Nos. 51279165 and 51479170) and the National Defense Basic Scientific Research Program of China (Grant No. B2720133014).

  20. Reactive Planning of Autonomous Vehicles for Traffic Scenarios

    Directory of Open Access Journals (Sweden)

    Rahul Kala

    2015-10-01

    Full Text Available Autonomous vehicles operate in real time traffic scenarios and aim to reach their destination from their source in the most efficient manner possible. Research in mobile robotics provides a variety of sophisticated means with which to plan the path of these vehicles. Conversely professional human drivers usually drive using instinctive means, which enables them to reach their goal almost optimally whilst still obeying all traffic laws. In this paper we propose the use of fuzzy logic for novel motion planning. The planner is generated using an evolutionary algorithm which resembles the learning stage of professional drivers. Whether to overtake or not, is a decision which affects one’s driving and the decision is made using some deliberation. We further extend the approach to perform decision making regarding overtaking for all vehicles. Further we coordinate the motion of the vehicles at a traffic crossing to avoid any potential jam or collision. Experimental results prove that by using this approach we have been able to make the vehicles move in an optimal manner in a variety of scenarios.

  1. Guidance of Autonomous Amphibious Vehicles for Flood Rescue Support

    OpenAIRE

    Shankarachary Ragi; ChingSeong Tan; Chong, Edwin K. P.

    2013-01-01

    We develop a path-planning algorithm to guide autonomous amphibious vehicles (AAVs) for flood rescue support missions. Specifically, we develop an algorithm to control multiple AAVs to reach/rescue multiple victims (also called targets) in a flood scenario in 2D, where the flood water flows across the scene and the targets move (drifted by the flood water) along the flood stream. A target is said to be rescued if an AAV lies within a circular region of a certain radius around the target. The ...

  2. An autonomous vehicle approach for quantifying bioluminescence in ports and harbors

    Science.gov (United States)

    Moline, Mark; Bissett, Paul; Blackwell, Shelley; Mueller, James; Sevadjian, Jeff; Trees, Charles; Zaneveld, Ron

    2005-05-01

    Bioluminescence emitted from marine organisms upon mechanical stimulation is an obvious military interest, as it provides a low-tech method of identifying surface and subsurface vehicles and swimmer tracks. Clearly, the development of a passive method of identifying hostile ships, submarines, and swimmers, as well as the development of strategies to reduce the risk of detection by hostile forces is relevant to Naval operations and homeland security. The measurement of bioluminescence in coastal waters has only recently received attention as the platforms and sensors were not scaled for the inherent small-scale nature of nearshore environments. In addition to marine forcing, many ports and harbors are influenced by freshwater inputs, differential density layering and higher turbidity. The spatial and temporal fluctuations of these optical water types overlaid on changes in the bioluminescence potential make these areas uniquely complex. The development of an autonomous underwater vehicle with a bioluminescence capability allows measurements on sub-centimeter horizontal and vertical scales in shallow waters and provides the means to map the potential for detection of moving surface or subsurface objects. A deployment in San Diego Bay shows the influence of tides on the distribution of optical water types and the distribution of bioluminescent organisms. Here, these data are combined to comment on the potential for threat reduction in ports and harbors.

  3. Radar system on a large autonomous vehicle for personnel avoidance

    Science.gov (United States)

    Silvious, Jerry; Wellman, Ron; Tahmoush, Dave; Clark, John

    2010-04-01

    The US Army Research Laboratory designed, developed and tested a novel switched beam radar system operating at 76 GHz for use in a large autonomous vehicle to detect and identify roadway obstructions including slowly-moving personnel. This paper discusses the performance requirements for the system to operate in an early collision avoidance mode to a range of 150 meters and at speeds of over 20 m/s. We report the measured capabilities of the system to operate in these modes under various conditions, such as rural and urban environments, and on various terrains, such as asphalt and grass. Finally, we discuss the range-Doppler map processing capabilities that were developed to correct for platform motion and identify roadway vehicles and personnel moving at 1 m/s or more along the path of the system.

  4. A Neural Auto-depth Controller for an Unmanned Underwater Vehicle

    Science.gov (United States)

    Sutton, R.; Johnson, C.; Roberts, G. N.

    Artificial neural networks offer an alternative strategy for the nonlinear control of unmanned underwater vehicles (UUVS). This paper investigates the use of a multi-layered perceptron (MLP) network in controlling an UUV over a sea-bed profile and compares the use of applying chemotaxis learning to that of the more commonly employed back propagation algorithm. The results show that, for differing sized MLPs, the chemotaxis algorithm produces a successful controller over the sea-bed profile in an improved training time. Also it will be shown that, in the presence of noise and change in vehicle mass, the neural controller out-performed a classical proportional-integral-derivative controller.

  5. GROVER: An autonomous vehicle for ice sheet research

    Science.gov (United States)

    Trisca, G. O.; Robertson, M. E.; Marshall, H.; Koenig, L.; Comberiate, M. A.

    2013-12-01

    The Goddard Remotely Operated Vehicle for Exploration and Research or Greenland Rover (GROVER) is a science enabling autonomous robot specifically designed to carry a low-power, large bandwidth radar for snow accumulation mapping over the Greenland Ice Sheet. This new and evolving technology enables reduced cost and increased safety for polar research. GROVER was field tested at Summit, Greenland in May 2013. The robot traveled over 30 km and was controlled both by line of sight wireless and completely autonomously with commands and telemetry via the Iridium Satellite Network, from Summit as well as remotely from Boise, Idaho. Here we describe GROVER's unique abilities and design. The software stack features a modular design that can be adapted for any application that requires autonomous behavior, reliable communications using different technologies and low level control of peripherals. The modules are built to communicate using the publisher-subscriber design pattern to maximize data-reuse and allow for graceful failures at the software level, along with the ability to be loaded or unloaded on-the-fly, enabling the software to adopt different behaviors based on power constraints or specific processing needs. These modules can also be loaded or unloaded remotely for servicing and telemetry can be configured to contain any kind of information being generated by the sensors or scientific instruments. The hardware design protects the electronic components and the control system can change functional parameters based on sensor input. Power failure modes built into the hardware prevent the vehicle from running out of energy permanently by monitoring voltage levels and triggering software reboots when the levels match pre-established conditions. This guarantees that the control software will be operational as soon as there is enough charge to sustain it, giving the vehicle increased longevity in case of a temporary power loss. GROVER demonstrates that autonomous rovers

  6. Computer vision techniques for underwater navigation

    OpenAIRE

    Barngrover, Christopher M.

    2010-01-01

    In the world of autonomous underwater vehicles (AUV) the prominent form of sensing has been sonar due to cloudy water conditions and dispersion of light. Although underwater conditions are highly suitable for sonar, this does not mean that vision techniques should be completely ignored. There are situations where visibility is high, such is in calm waters, and where light dispersion is not an issue, such as shallow water or near the surface. In addition, even when visibility is low, once a ce...

  7. Computer vision applied to underwater robotics

    OpenAIRE

    Pazzaglia, Fabio

    2016-01-01

    Ocean and seafloors are today probably the less known and unexplored places on earth.Nowadays, the continuous technological improvements on underwater inspection offer new challenges and possibilities. Beside the lassic acoustic sensors, modern cameras are playing an ever increasing role in autonomous underwater navigation. In particular, The capability to perform a context-driven navigation, based on what the vehicle is actually seeing on the seafloor, is of great interest in many research f...

  8. Application of parallelized software architecture to an autonomous ground vehicle

    Science.gov (United States)

    Shakya, Rahul; Wright, Adam; Shin, Young Ho; Momin, Orko; Petkovsek, Steven; Wortman, Paul; Gautam, Prasanna; Norton, Adam

    2011-01-01

    This paper presents improvements made to Q, an autonomous ground vehicle designed to participate in the Intelligent Ground Vehicle Competition (IGVC). For the 2010 IGVC, Q was upgraded with a new parallelized software architecture and a new vision processor. Improvements were made to the power system reducing the number of batteries required for operation from six to one. In previous years, a single state machine was used to execute the bulk of processing activities including sensor interfacing, data processing, path planning, navigation algorithms and motor control. This inefficient approach led to poor software performance and made it difficult to maintain or modify. For IGVC 2010, the team implemented a modular parallel architecture using the National Instruments (NI) LabVIEW programming language. The new architecture divides all the necessary tasks - motor control, navigation, sensor data collection, etc. into well-organized components that execute in parallel, providing considerable flexibility and facilitating efficient use of processing power. Computer vision is used to detect white lines on the ground and determine their location relative to the robot. With the new vision processor and some optimization of the image processing algorithm used last year, two frames can be acquired and processed in 70ms. With all these improvements, Q placed 2nd in the autonomous challenge.

  9. PRIMUS: autonomous navigation in open terrain with a tracked vehicle

    Science.gov (United States)

    Schaub, Guenter W.; Pfaendner, Alfred H.; Schaefer, Christoph

    2004-09-01

    The German experimental robotics program PRIMUS (PRogram for Intelligent Mobile Unmanned Systems) is focused on solutions for autonomous driving in unknown open terrain, over several project phases under specific realization aspects for more than 12 years. The main task of the program is to develop algorithms for a high degree of autonomous navigation skills with off-the-shelf available hardware/sensor technology and to integrate this into military vehicles. For obstacle detection a Dornier-3D-LADAR is integrated on a tracked vehicle "Digitized WIESEL 2". For road-following a digital video camera and a visual perception module from the Universitaet der Bundeswehr Munchen (UBM) has been integrated. This paper gives an overview of the PRIMUS program with a focus on the last program phase D (2001 - 2003). This includes the system architecture, the description of the modes of operation and the technology development with the focus on obstacle avoidance and obstacle classification using a 3-D LADAR. A collection of experimental results and a short look at the next steps in the German robotics program will conclude the paper.

  10. Nonlinear output feedback control of underwater vehicle propellers using feedback form estimated axial flow velocity

    DEFF Research Database (Denmark)

    Fossen, T.I.; Blanke, M.

    2000-01-01

    Accurate propeller shaft speed controllers can be designed by using nonlinear control theory and feedback from the axial water velocity in the propeller disc. In this paper, an output feedback controller is derived, reconstructing the axial flow velocity from vehicle speed measurements, using a...... three-state model of propeller shaft speed, forward (surge) speed of the vehicle, and the axial flow velocity. Lyapunov stability theory is used to prove that a nonlinear observer combined with an output feedback integral controller provide exponential stability. The output feedback controller...... compensates for variations in thrust due to time variations in advance speed. This is a major problem when applying conventional vehicle-propeller control systems, The proposed controller is simulated for an underwater vehicle equipped with a single propeller. The simulations demonstrate that the axial water...

  11. Nonlinear Output Feedback Control of Underwater Vehicle Propellers using Advance Speed Feedback

    DEFF Research Database (Denmark)

    Fossen, T.I.; Blanke, M.

    1999-01-01

    More accurate propeller shaft speed controllers can be designed by using nonlinear control theory. In this paper, an output feedback controller reconstructing the advance speed (speed of water going into the propeller) from vehicle speed measurements is derived. For this purpose a three-state model...... of propeller shaft speed, forward (surge) speed of the vehicle and axial inlet flow of the propeller is applied. A nonlinear observer in combination with an output feedback integral controller are derived by applying Lyapunov stability theory and exponential stability is proven. The output feedback...... controller minimizes thruster losses due to variations in propeller axial inlet flow which is a major problem when applying conventional vehicle-propeller control systems. The proposed controller is simulated for an underwater vehicle equipped with a single propeller. From the simulations it can be concluded...

  12. Motion Planning of Autonomous Vehicles on a Dual Carriageway without Speed Lanes

    Directory of Open Access Journals (Sweden)

    Rahul Kala

    2015-01-01

    Full Text Available The problem of motion planning of an autonomous vehicle amidst other vehicles on a straight road is considered. Traffic in a number of countries is unorganized, where the vehicles do not move within predefined speed lanes. In this paper, we formulate a mechanism wherein an autonomous vehicle may travel on the “wrong” side in order to overtake a vehicle. Challenges include assessing a possible overtaking opportunity, cooperating with other vehicles, partial driving on the “wrong” side of the road and safely going to and returning from the “wrong” side. The experimental results presented show vehicles cooperating to accomplish overtaking manoeuvres.

  13. Research on Underwater Vehicle Based on Multiphase Flow Control

    Directory of Open Access Journals (Sweden)

    Zhang Xiaoshi

    2015-01-01

    Full Text Available The commercial software ANSYS CFX is used for modeling the hydrodynamic characteristics of submarine-launched vehicle. In the numerical simulations, the SST (Shear Stress Transport turbulence model is employed to describe the turbulence phenomenon occurring in the continuous fluid. The Rayleigh-Plesset equations are applied to analyze the cavitation phenomenon. Three-dimensional numerical simulation was carried out to study the cavity shape, the surface pressure distribution and the drag force with different flow control. The result shows that the gas and the number of ventilation holes control to show any significant impact on the cavity shape and the surface pressure are effective measures to decrease resistance.

  14. Broadband vehicle-to-vehicle communication using an extended autonomous cruise control sensor

    Science.gov (United States)

    Heddebaut, M.; Rioult, J.; Ghys, J. P.; Gransart, Ch; Ambellouis, S.

    2005-06-01

    For several years road vehicle autonomous cruise control (ACC) systems as well as anti-collision radar have been developed. Several manufacturers currently sell this equipment. The current generation of ACC sensors only track the first preceding vehicle to deduce its speed and position. These data are then used to compute, manage and optimize a safety distance between vehicles, thus providing some assistance to car drivers. However, in real conditions, to elaborate and update a real time driving solution, car drivers use information about speed and position of preceding and following vehicles. This information is essentially perceived using the driver's eyes, binocular stereoscopic vision performed through the windscreens and rear-view mirrors. Furthermore, within a line of vehicles, the frontal road perception of the first vehicle is very particular and highly significant. Currently, all these available data remain strictly on-board the vehicle that has captured the perception information and performed these measurements. To get the maximum effectiveness of all these approaches, we propose that this information be shared in real time with the following vehicles, within the convoy. On the basis of these considerations, this paper technically explores a cost-effective solution to extend the basic ACC sensor function in order to simultaneously provide a vehicle-to-vehicle radio link. This millimetre wave radio link transmits relevant broadband perception data (video, localization...) to following vehicles, along the line of vehicles. The propagation path between the vehicles uses essentially grazing angles of incidence of signals over the road surface including millimetre wave paths beneath the cars.

  15. Sensing, Control, and System Integration for Autonomous Vehicles: A Series of Challenges

    Science.gov (United States)

    Özgüner, Ümit; Redmill, Keith

    One of the important examples of mechatronic systems can be found in autonomous ground vehicles. Autonomous ground vehicles provide a series of challenges in sensing, control and system integration. In this paper we consider off-road autonomous vehicles, automated highway systems and urban autonomous driving and indicate the unifying aspects. We specifically consider our own experience during the last twelve years in various demonstrations and challenges in attempting to identify unifying themes. Such unifying themes can be observed in basic hierarchies, hybrid system control approaches and sensor fusion techniques.

  16. Environmental modeling and recognition for an autonomous land vehicle

    Science.gov (United States)

    Lawton, D. T.; Levitt, T. S.; Mcconnell, C. C.; Nelson, P. C.

    1987-01-01

    An architecture for object modeling and recognition for an autonomous land vehicle is presented. Examples of objects of interest include terrain features, fields, roads, horizon features, trees, etc. The architecture is organized around a set of data bases for generic object models and perceptual structures, temporary memory for the instantiation of object and relational hypotheses, and a long term memory for storing stable hypotheses that are affixed to the terrain representation. Multiple inference processes operate over these databases. Researchers describe these particular components: the perceptual structure database, the grouping processes that operate over this, schemas, and the long term terrain database. A processing example that matches predictions from the long term terrain model to imagery, extracts significant perceptual structures for consideration as potential landmarks, and extracts a relational structure to update the long term terrain database is given.

  17. Human vs autonomous control of planetary roving vehicles

    Science.gov (United States)

    Whitney, W. M.

    1974-01-01

    Supervisory or semiautonomous control has some compelling advantages over step-by-step human command and verification for the operation of roving vehicles on remote planetary surfaces. There are also disadvantages in relation to the complex system that must be mobilized and the chain of events that must be enacted to conduct a mission. Which of the two control methods is better on technical grounds may not be the deciding factor in its acceptance or rejection. Some of the issues that affect changes in spacecraft design and operation are summarized. To accelerate the movement toward more autonomous machines, it will be necessary to understand and to address the problems that such autonomy will create for other elements of the control system and for the control process.

  18. NONLINEAR ESTIMATION METHODS FOR AUTONOMOUS TRACKED VEHICLE WITH SLIP

    Institute of Scientific and Technical Information of China (English)

    ZHOU Bo; HAN Jianda

    2007-01-01

    In order to achieve precise, robust autonomous guidance and control of a tracked vehicle, a kinematic model with longitudinal and lateral slip is established. Four different nonlinear filters are used to estimate both state vector and time-varying parameter vector of the created model jointly. The first filter is the well-known extended Kalman filter. The second filter is an unscented version of the Kalman filter. The third one is a particle filter using the unscented Kalman filter to generate the importance proposal distribution. The last one is a novel and guaranteed filter that uses a linear set-membership estimator and can give an ellipsoid set in which the true state lies. The four different approaches have different complexities, behavior and advantages that are surveyed and compared.

  19. Autonomous guided vehicles methods and models for optimal path planning

    CERN Document Server

    Fazlollahtabar, Hamed

    2015-01-01

      This book provides readers with extensive information on path planning optimization for both single and multiple Autonomous Guided Vehicles (AGVs), and discusses practical issues involved in advanced industrial applications of AGVs. After discussing previously published research in the field and highlighting the current gaps, it introduces new models developed by the authors with the goal of reducing costs and increasing productivity and effectiveness in the manufacturing industry. The new models address the increasing complexity of manufacturing networks, due for example to the adoption of flexible manufacturing systems that involve automated material handling systems, robots, numerically controlled machine tools, and automated inspection stations, while also considering the uncertainty and stochastic nature of automated equipment such as AGVs. The book discusses and provides solutions to important issues concerning the use of AGVs in the manufacturing industry, including material flow optimization with A...

  20. 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.

  1. Active control of passive acoustic fields: passive synthetic aperture/Doppler beamforming with data from an autonomous vehicle.

    Science.gov (United States)

    D'Spain, Gerald L; Terrill, Eric; Chadwell, C David; Smith, Jerome A; Lynch, Stephen D

    2006-12-01

    The maneuverability of autonomous underwater vehicles (AUVs) equipped with hull-mounted arrays provides the opportunity to actively modify received acoustic fields to optimize extraction of information. This paper uses ocean acoustic data collected by an AUV-mounted two-dimensional hydrophone array, with overall dimension one-tenth wavelength at 200-500 Hz, to demonstrate aspects of this control through vehicle motion. Source localization is performed using Doppler shifts measured at a set of receiver velocities by both single elements and a physical array. Results show that a source in the presence of a 10-dB higher-level interferer having exactly the same frequency content (as measured by a stationary receiver) is properly localized and that white-noise-constrained adaptive beamforming applied to the physical aperture data in combination with Doppler beamforming provides greater spatial resolution than physical-aperture-alone beamforming and significantly lower sidelobes than single element Doppler beamforming. A new broadband beamformer that adjusts for variations in vehicle velocity on a sample by sample basis is demonstrated with data collected during a high-acceleration maneuver. The importance of including the cost of energy expenditure in determining optimal vehicle motion is demonstrated through simulation, further illustrating how the vehicle characteristics are an integral part of the signal/array processing structure. PMID:17225392

  2. 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.

  3. Characterization of optical communication in a leader-follower unmanned underwater vehicle formation

    Science.gov (United States)

    Eren, Firat; Pe'eri, Shachak; Thein, May-Win

    2013-06-01

    As part of the research to development an optical communication design of a leader-follower formation between unmanned underwater vehicles (UUVs), this paper presents light field characterization and design configuration of the hardware required to allow the use of distance detection between UUVs. The study specifically is targeting communication between remotely operated vehicles (ROVs). As an initial step in this study, the light field produced from a light source mounted on the leader UUV was empirically characterized and modeled. Based on the light field measurements, a photo-detector array for the follower UUV was designed. Evaluation of the communication algorithms to monitor the UUV's motion was conducted through underwater experiments in the Ocean Engineering Laboratory at the University of New Hampshire. The optimal spectral range was determined based on the calculation of the diffuse attenuation coefficients by using two different light sources and a spectrometer. The range between the leader and the follower vehicles for a specific water type was determined. In addition, the array design and the communication algorithms were modified according to the results from the light field.

  4. Towards on-line underwater vehicle trajectory estimation using diffusion-based observers

    DEFF Research Database (Denmark)

    Jouffroy, Jerome; Nguyen, Tu Duc

    This work extends previous work (Jouffroy and Opderbecke, 2004) on the estimation of underwater vehicle trajectories using Gyro-Doppler (body-fixed velocities) and acoustic signals (earth-fixed positions). The approach consists of diffusion-based observers processing a whole trajectory segment at a...... time, allowing the consideration of important practical problems such as different information update rates, outages, and outliers in a very simple framework. We detail issues related to real-time applications, such as implementation and convergence. A theorem guaranteeing stability of the observer and...

  5. Pilot Study of Systems to Drive Autonomous Vehicles on Test Tracks

    OpenAIRE

    Agardt, Erik; Löfgren, Markus

    2008-01-01

    This Master’s thesis is a pilot study that investigates different systems to drive autonomous and non-autonomous vehicles simultaneously on test tracks. The thesis includes studies of communication, positioning, collision avoidance, and techniques for surveillance of vehicles which are suitable for implementation. The investigation results in a suggested system outline. Differential GPS combined with laser scanner vision is used for vehicle state estimation (position, heading, velocity, etc.)...

  6. 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...

  7. The alkaline aluminium/hydrogen peroxide power source in the Hugin II unmanned underwater vehicle

    Science.gov (United States)

    Hasvold, Øistein; Johansen, Kjell Håvard; Mollestad, Ole; Forseth, Sissel; Størkersen, Nils

    In 1993, The Norwegian Defence Research Establishment (FFI) demonstrated AUV-Demo, an unmanned (untethered) underwater vehicle (UUV), powered by a magnesium/dissolved oxygen seawater battery (SWB). This technology showed that an underwater range of at least 1000 nautical miles at a speed of 4 knots was possible, but also that the maximum hotel load this battery system could support was very limited. Most applications for UUV technology need more power over a shorter period of time. Seabed mapping using a multibeam echo sounder mounted on an UUV was identified as a viable application and the Hugin project was started in 1995 in cooperation with Norwegian industry. For this application, an endurance of 36 h at 4 knots was required. Development of the UUV hull and electronics system resulted in the UUV Hugin I. It carries a Ni/Cd battery of 3 kW h, allowing up to 6 h under-water endurance. In parallel, we developed a battery based on a combination of alkaline Al/air and SWB technology, using a circulating alkaline electrolyte, aluminium anodes and maintaining the oxidant concentration in the electrolyte by continuously adding hydrogen peroxide (HP) to the electrolyte. This concept resulted in a safe battery, working at ambient pressure (balanced) and with sufficient power and energy density to allow the UUV Hugin II to make a number of successive dives, each of up to 36 h duration and with only 1 h deck time between dives for HP refill and electrolyte exchange. After 100 h, an exchange of anodes takes place. The power source consists of a four-cell Al/HP battery, a DC/DC converter delivering 600 W at 30 V, circulation and dosing pumps and a battery control unit. Hugin II is now in routine use by the Norwegian Underwater Intervention AS (NUI) which operates the UUV for high-precision seabed mapping down to a water depth of 600 m.

  8. Short-Range Sensor for Underwater Robot Navigation using Line-lasers and Vision

    DEFF Research Database (Denmark)

    Hansen, Peter Nicholas; Nielsen, Mikkel Cornelius; Christensen, David Johan;

    2015-01-01

    This paper investigates a minimalistic laser-based range sensor, used for underwater inspection by Autonomous Underwater Vehicles (AUV). This range detection system system comprise two lasers projecting vertical lines, parallel to a camera’s viewing axis, into the environment. Using both lasers...

  9. Power Sources for Micro-Autonomous Vehicles- Challenges and Prospects

    Science.gov (United States)

    Narayan, S. R.; Kisor, A.; Valdez, T. I.; Manohara, H.

    2009-01-01

    Micro-autonomous vehicle systems are expected to have expanded role in military missions by providing full spectrum intelligence, surveillance and reconnaissance support on the battlefield, suppression of enemy defenses, and enabling co-operative (swarm-like) configurations. Of the numerous demanding requirements of autonomy, sensing, navigation, mobility, etc., meeting the requirement of mission duration or endurance is a very challenging one. This requirement is demanding because of the constraints of mass and volume that limit the quantity of energy that can be stored on-board. Energy is required for mobility, payload operation, information processing, and communication. Mobility requirements typically place an extraordinary demand on the specific energy (Wh/kg) and specific power (W/kg) of the power source; the actual distribution of the energy between mobility and other system functions could vary substantially with the mission type. The power requirements for continuous mobility can vary from 100-1000 W/kg depending on the terrain, ground speed and flight speed. Even with the power source accounting for 30% of the mass of the vehicle, the best of rechargeable batteries can provide only up to 1-2 hours of run-time for a continuous power demand at 100W/kg. In the case of micro-aerial vehicles with flight speed requirements in the range of 5-15 m s-1, the mission times rarely exceed 20 minutes [2]. Further, the power required during take-off and hover can be twice or thrice that needed for steady level flight, and thus the number and sequence of such events is also limited by the mass and size of the power source. For operations such as "perch and stare" or "silent watch" the power demand is often only a tenth of that required during continuous flight. Thus, variation in power demand during various phases of the mission importantly affects the power source selection.

  10. Design of a Hybrid Controller for Autonomous Vehicles Driving on Automated Highways

    OpenAIRE

    Girault, Alain

    2001-01-01

    In this paper we address the problem of the hybrid control of autonomous vehicles driving on automated highways. Vehicles are autonomous, so they do not communicate with each other nor with the infrastructure. Two problems have to be dealt with: A vehicle driving in a single-lane highway must never collide with its leading vehicle; and a vehicle entering the highway at a designated entry junction mustb e able to merge from the merging lane to the main lane, again without any collision. To sol...

  11. Target location by self-organizing autonomous air vehicles

    Science.gov (United States)

    Brown, Kim; Bowyer, Richard S.; Koks, Don

    2002-08-01

    Target location is a problem where the application of multiple sensors that are geographically distributed can determine or improve the location estimate of a target. If these sensors are capable of cooperative behaviour then the information from each sensor can be autonomously fused to provide an estimate of the target position. The individual sensors may be quite unsophisticated, yet the observation system that is created through cooperation and adaptive networking of these sensors provides sufficient process gain to achieve target location accuracies similar to those of expensive centralized sensor systems. The accuracy of target location estimates depends heavily on the separation distance between the sensors. Large baseline geometry takes advantage of many seemingly unsophisticated bearing measurements that are organised into a coordinated observation system to locate a target. Team formation is one method to address coordination of distributed sensors, data fusion, sensor resource and energy management, and communication link control based on the concept of cooperating machines1,2,3. We apply an algorithm for agent team formation4 inspired by the self-organising behaviour observed in colonies of ants, to the problem of integrating the sensors of a group of networked mini-Autonomous Air Vehicles (AAVs). The mini-AAVs are tasked to locate targets within a region of interest. The challenge we address is to make the location estimation system adaptive to a dynamic environment and robust to failure. Simulation results are presented which address issues in distributed data fusion, sensor resource and energy management, and communication link control, for a group of mini-AAVs.

  12. A Low Speed Maneuvering Technology for Docking of Unmanned Underwater Vehicles

    Science.gov (United States)

    Mohseni, K.

    2006-12-01

    Reliable docking mechanisms are essential for operation of AUV networks in harsh environment such as under ice in polar region. Hydrodynamic design of AUVs are often driven on a few competing fronts: (i) Rapid and efficient deployment to the work-zone and (ii) low speed maneuvering during the docking procedure and for operations at the work-zone. Rapid deployment necessitates a streamlined body of revolution (eg. Torpedo- shape design) for fast cruising with minimal energy. However, since the trajectory of this type of vehicles is adjusted using control surfaces, the magnitude of the available control force is proportional to the vehicle's speed. Consequently, these vehicles are difficult to maneuver at low speeds and in tight spaces. Therefore, they are particularly difficult to dock. Such vehicles also cannot opportunistically enter a precise loitering or hovering mode. As a result much current effort is devoted to the development of docking mechanisms, but this is just a solution for the symptoms, and does not really address the problem of the vehicle's actual maneuvering capabilities. On the other hand, low speed maneuvering and better control are often achieved by the so-called box-design where the low drag body-of-revolution design is sacrificed by adding multiple thrusters at different locations and directions. In this case, precise maneuvering can be achieved at the cost of increased drag and the need for an alternate technique to transport the vehicle from the offshore base or an escort ship to the work-zone. In an effort to resolve this trade-off, we have recently proposed to use compact synthetic jets for low speed maneuvering or locomotion of small unmanned underwater vehicles (UUVs). Inspired by the propulsion of cephalopod, we have designed and implemented compact vortex generators for low speed maneuvering, station keeping, and docking of small underwater vehicles. Design, fabrication, thrust optimization, and implementation of such compact actuators

  13. Introduction to autonomous manipulation case study with an underwater robot, SAUVIM

    CERN Document Server

    Marani, Giacomo

    2014-01-01

    Autonomous manipulation” is a challenge in robotic technologies. It refers to the capability of a mobile robot system with one or more manipulators that performs intervention tasks requiring physical contacts in unstructured environments and without continuous human supervision. Achieving autonomous manipulation capability is a quantum leap in robotic technologies as it is currently beyond the state of the art in robotics. This book addresses issues with the complexity of the problems encountered in autonomous manipulation including representation and modeling of robotic structures, kinematic and dynamic robotic control, kinematic and algorithmic singularity avoidance, dynamic task priority, workspace optimization and environment perception. Further development in autonomous manipulation should be able to provide robust improvements of the solutions for all of the above issues. The book provides an extensive tract on sensory-based autonomous manipulation for intervention tasks in unstructured environment...

  14. Visible Light Inter-Vehicle Communication for Platooning of Autonomous Vehicles

    OpenAIRE

    Abualhoul, Mohammad; Shagdar, Oyunchimeg; Nashashibi, Fawzi

    2016-01-01

    — In this paper, we study a use of Visible Light Communication (VLC) technology for a platoon of autonomous vehicles. We present a low-cost, low-latency and simple outdoor VLC prototype, which can be installed as a vehicular tail-lighting system. The architecture of our VLC system is introduced , followed by performance evaluation with an especial attention on the VLC link resilience to ambient noise and communication range. Through the experiments, we observe that a use of proper optical fil...

  15. Feasibility of Turing-Style Tests for Autonomous Aerial Vehicle "Intelligence"

    Science.gov (United States)

    Young, Larry A.

    2007-01-01

    A new approach is suggested to define and evaluate key metrics as to autonomous aerial vehicle performance. This approach entails the conceptual definition of a "Turing Test" for UAVs. Such a "UAV Turing test" would be conducted by means of mission simulations and/or tailored flight demonstrations of vehicles under the guidance of their autonomous system software. These autonomous vehicle mission simulations and flight demonstrations would also have to be benchmarked against missions "flown" with pilots/human-operators in the loop. In turn, scoring criteria for such testing could be based upon both quantitative mission success metrics (unique to each mission) and by turning to analog "handling quality" metrics similar to the well-known Cooper-Harper pilot ratings used for manned aircraft. Autonomous aerial vehicles would be considered to have successfully passed this "UAV Turing Test" if the aggregate mission success metrics and handling qualities for the autonomous aerial vehicle matched or exceeded the equivalent metrics for missions conducted with pilots/human-operators in the loop. Alternatively, an independent, knowledgeable observer could provide the "UAV Turing Test" ratings of whether a vehicle is autonomous or "piloted." This observer ideally would, in the more sophisticated mission simulations, also have the enhanced capability of being able to override the scripted mission scenario and instigate failure modes and change of flight profile/plans. If a majority of mission tasks are rated as "piloted" by the observer, when in reality the vehicle/simulation is fully- or semi- autonomously controlled, then the vehicle/simulation "passes" the "UAV Turing Test." In this regards, this second "UAV Turing Test" approach is more consistent with Turing s original "imitation game" proposal. The overall feasibility, and important considerations and limitations, of such an approach for judging/evaluating autonomous aerial vehicle "intelligence" will be discussed from a

  16. Search and Classification Using Multiple Autonomous Vehicles Decision-Making and Sensor Management

    CERN Document Server

    Wang, Yue

    2012-01-01

    Search and Classification Using Multiple Autonomous Vehicles provides a comprehensive study of decision-making strategies for domain search and object classification using multiple autonomous vehicles (MAV) under both deterministic and probabilistic frameworks. It serves as a first discussion of the problem of effective resource allocation using MAV with sensing limitations, i.e., for search and classification missions over large-scale domains, or when there are far more objects to be found and classified than there are autonomous vehicles available. Under such scenarios, search and classification compete for limited sensing resources. This is because search requires vehicle mobility while classification restricts the vehicles to the vicinity of any objects found. The authors develop decision-making strategies to choose between these competing tasks and vehicle-motion-control laws to achieve the proposed management scheme. Deterministic Lyapunov-based, probabilistic Bayesian-based, and risk-based decision-mak...

  17. Cooperative energy harvesting for long-endurance autonomous vehicle teams

    Science.gov (United States)

    Page, S. F.; Rogers, J. D.; May, K.; Myatt, D. R.; Hickman, D.; Smith, M. I.

    2010-04-01

    This paper considers the exploitation of energy harvesting technologies for teams of Autonomous Vehicles (AVs). Traditionally, the optimisation of information gathering tasks such as searching for and tracking new objects, and platform level power management, are only integrated at a mission-management level. In order to truly exploit new energy harvesting technologies which are emerging in both the commercial and military domains (for example the 'EATR' robot and next-generation solar panels), the sensor management and power management processes must be directly coupled. This paper presents a novel non-myopic sensor management framework which addresses this issue through the use of a predictive platform energy model. Energy harvesting opportunities are modelled using a dynamic spatial-temporal energy map and sensor and platform actions are optimised according to global team utility. The framework allows the assessment of a variety of different energy harvesting technologies and perceptive tasks. In this paper, two representative scenarios are used to parameterise the model with specific efficiency and energy abundance figures. Simulation results indicate that the integration of intelligent power management with traditional sensor management processes can significantly increase operational endurance and, in some cases, simultaneously improve surveillance or tracking performance. Furthermore, the framework is used to assess the potential impact of energy harvesting technologies at various efficiency levels. This provides important insight into the potential benefits that intelligent power management can offer in relation to improving system performance and reducing the dependency on fossil fuels and logistical support.

  18. Clothoid-based Planning and Control in Intelligent Vehicles (Autonomous and Manual-Assisted Driving)

    OpenAIRE

    Girbés Juan, Vicent

    2016-01-01

    [EN] Nowadays, there are many electronic products that incorporate elements and features coming from the research in the field of mobile robotics. For instance, the well-known vacuum cleaning robot Roomba by iRobot, which belongs to the field of service robotics, one of the most active within the sector. There are also numerous autonomous robotic systems in industrial warehouses and plants. It is the case of Autonomous Guided Vehicles (AGVs), which are able to drive completely autonomously in...

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

    Science.gov (United States)

    Campos, Ricard; Gracias, Nuno; Ridao, Pere

    2016-01-01

    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. PMID:26999144

  20. 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.

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

    Science.gov (United States)

    Campos, Ricard; Gracias, Nuno; Ridao, Pere

    2016-01-01

    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. PMID:26999144

  2. Editorial for special issue on Perception and Navigation for Autonomous Vehicles

    OpenAIRE

    Laugier, Christian; Philippe, Martinet; Urbano, Nunes

    2014-01-01

    International audience This Special Issue of the IEEE Robotics and Automation Magazine has been prepared in the scope of the activities of the Technical Committee on "Autonomous Ground Vehicle and Intelligent Transportation System" (AGV-ITS) (http://www.ieee-ras.org/autonomous-groundvehicles- and-intelligent-transportation-systems) of the IEEE Robotics and Automation Society (IEEE RAS).

  3. An acoustically controlled tetherless underwater vehicle for installation and maintenance of neutrino detectors in the deep ocean

    CERN Document Server

    Ballou, P J

    1997-01-01

    The task of installing and servicing high energy neutrino detectors in the deep ocean from a surface support vessel is problematic using conventional tethered systems. An array of multiple detector strings rising 500 m from the ocean floor, and forming a grid with 50 m spacing between the strings, presents a substantial entanglement hazard for equipment cables deployed from the surface. Such tasks may be accomplished with fewer risks using a tetherless underwater remotely operated vehicle that has a local acoustic telemetry link to send control commands and sensor data between the vehicle and a stationary hydrophone suspended above or just outside the perimeter of the work site. The Phase I effort involves the development of an underwater acoustic telemetry link for vehicle control and sensor feedback, the evaluation of video compression methods for real-time acoustic transmission of video through the water, and the defining of local control routines on board the vehicle to allow it to perform certain basic m...

  4. Control of an Autonomous Vehicle for Registration of Weed and Crop in Precision Agriculture

    DEFF Research Database (Denmark)

    Nielsen, Kirsten Mølgaard; Andersen, Palle; Pedersen, Tom Søndergaard;

    2002-01-01

    The paper describes the development of an autonomous electrical vehicle to be used for weed mapping in precision agriculture with special focus on the conceptual framework of the control system. The lowest layer of the control system is the propulsion and steering control, the second layer...... coordinates the movements of the wheel units, the third layer is path execution and perception and the upper layer performs planning and reasoning. The control system is implemented on an autonomous vehicle. The vehicle has been tested for path following and position accuracy. Based on the results a new...... vehicle is under construction....

  5. Low-cost multi-terrain autonomous vehicle for hostile environments

    Energy Technology Data Exchange (ETDEWEB)

    Perez, M. L., LLNL

    1996-12-03

    This paper describes an innovative and unique autonomous vehicle being developed at the Lawrence Livermore National Laboratory (LLNL) for versatile use in hostile environments. Conventional vehicles used in decommissioning and decontaminating, police activity, and unmanned military operations typically are designed with four-wheels or track in contact with the environment. Although four-wheel and track vehicles work well, they are limited in negotiating saturated terrain, steep hills and soft soils. The Spiral Track Autonomous Robot (STAR) is a versatile and maneuverable multi-terrain mobile vehicle that uses the latest available computer technology and two Archimedes screws, in contact with the local environment to intelligently negotiate a hostile environment.

  6. 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.

  7. InfoRank: Information-Centric Autonomous Identification of Popular Smart Vehicles

    OpenAIRE

    Khan, Junaid Ahmed; Ghamri-Doudane, Yacine; Botvich, Dmitri

    2015-01-01

    International audience —Modern cars are transforming towards autonomous cars capable to make intelligent decisions to facilitate our travel comfort and safety. Such " Smart Vehicles " are equipped with various sensor platforms and cameras to collect, store and share tremendous amount of heterogeneous data from urban streets. This paper addresses the efficient collection and distribution of such massive data by allowing a popular Smart Vehicle to autonomously decide its user relevant import...

  8. Application of Icelandic Tort Law to Autonomous Vehicles: Analysis of Legal Challenges and Practical Problems under the current regulatory framework

    OpenAIRE

    Rúnarsson, Bjarni Freyr

    2015-01-01

    In recent years, autonomous vehicles have attracted much attention. While such vehicles will have an immense potential in increasing traffic safety, they will be involved in traffic accidents. In Chapter 2, the term autonomous vehicle is defined, positively and negatively. Further, it is sought to shed light on the social impact of autonomous vehicles. Also, some challenges that they will pose are discussed, particularly some profound legal problems in various areas of the law. In Chapter 3...

  9. Scan matching SLAM in underwater environments

    OpenAIRE

    Mallios, Angelos; Ridao Rodríguez, Pere; Ribas Romagós, David; Hernàndez Bes, Emili

    2014-01-01

    This paper proposes a pose-based algorithm to solve the full simultaneous localization and mapping problem for autonomous underwater vehicle (AUV) navigating in unknown and possibly unstructured environments. The proposed method first estimates the local path traveled by the robot while forming the acoustic image (scan) with range data coming from a mono-beam rotating sonar head, providing position estimates for correcting the distortions that the vehicle motion produces in the scans. Then, c...

  10. Autonomy through SLAM for an Underwater Robot

    OpenAIRE

    Folkesson, John; Leonard, John,

    2011-01-01

    An autonomous underwater vehicle (AUV) is achieved that integrates state of the art simultaneous localization and mapping (SLAM) into the decision processes. This autonomy is used to carry out undersea target reacquisition missions that would otherwise be impossible with a low-cost platform. The AUV requires only simple sensors and operates without navigation equipment such as Doppler Velocity Log, inertial navigation or acoustic beacons. Demonstrations of the capability show that the vehicle...

  11. Design and testing of a shape memory alloy buoyancy engine for unmanned underwater vehicles

    Science.gov (United States)

    Angilella, Alex J.; Gandhi, Farhan S.; Miller, Timothy F.

    2015-11-01

    The US Navy’s 2004 Unmanned Underwater Vehicle (UUV) Master Plan outlines the Navy’s aim to expand the role of UUVs, and one of the key areas of interest is the increase in UUV range and endurance. A class of UUVs known as underwater gliders achieves this objective by cyclically modifying its buoyancy and covering horizontal distance with a climb/dive pattern. The present study proposes the use of shape memory alloys (SMAs) in a buoyancy heat engine where the oceanic thermocline would be exploited to produce martensite-austenite phase transformations that in turn change the buoyancy of a piston-cylinder prototype. The working principle of the device involves transitioning between the following two states. At low temperature (at depth) the SMA wires are tensioned into a detwinned martensitic state by a parallel compressed spring. This moves the piston within the cylinder to increase the chamber dry volume and device buoyancy. At higher temperatures (near the surface) the SMA wires undergo a martensite-to-austenite phase transformation, recover part of the applied strain, and reduce the volume and buoyancy of the piston-cylinder. This paper presents the analysis, design, fabrication, and testing of a prototype device. The prototype was immersed in a water bath, and it was demonstrated that its volume would change, as expected, with change in temperature of the water bath. Simulation results showed good correlation with test data.

  12. New Concepts and Perspectives on Micro-Rotorcraft and Small Autonomous Rotary-Wing Vehicles

    Science.gov (United States)

    Young, Larry A.; Aiken, E. W.; Johnson, J. L.; Demblewski, R.; Andrews, J.; Aiken, Irwin W. (Technical Monitor)

    2001-01-01

    A key part of the strategic vision for rotorcraft research as identified by senior technologists within the Army/NASA Rotorcraft Division at NASA Ames Research Center is the development and use of small autonomous rotorcraft. Small autonomous rotorcraft are defined for the purposes of this paper to be a class of vehicles that range in size from rotary-wing micro air vehicles (MAVs) to larger, more conventionally sized, rotorcraft uninhabited aerial vehicles (UAVs) - i.e. vehicle gross weights ranging from hundreds of grams to thousands of kilograms. The development of small autonomous rotorcraft represents both a technology challenge and a potential new vehicle class that will have substantial societal impact for: national security, personal transport, planetary science, and public service.

  13. A Framework for Analysing Driver Interactions with Semi-Autonomous Vehicles

    Directory of Open Access Journals (Sweden)

    Siraj Shaikh

    2012-12-01

    Full Text Available Semi-autonomous vehicles are increasingly serving critical functions in various settings from mining to logistics to defence. A key characteristic of such systems is the presence of the human (drivers in the control loop. To ensure safety, both the driver needs to be aware of the autonomous aspects of the vehicle and the automated features of the vehicle built to enable safer control. In this paper we propose a framework to combine empirical models describing human behaviour with the environment and system models. We then analyse, via model checking, interaction between the models for desired safety properties. The aim is to analyse the design for safe vehicle-driver interaction. We demonstrate the applicability of our approach using a case study involving semi-autonomous vehicles where the driver fatigue are factors critical to a safe journey.

  14. The use of autonomous unmanned vehicles for measuring the mean flow field in riverine environments

    Science.gov (United States)

    Tuggle, C.; Macmahan, J. H.; Brown, J.; Reniers, A. J.

    2010-12-01

    Autonomous unmanned vehicles (AUVs) are commonly used in oceanic, estuarine and, more recently, riverine environments because they are small, versatile, moving platforms equipped with a suite of instruments for measuring environmental conditions. However, moving vessel observations, particularly those associated acoustic Doppler current profiler (ADCP) observations, can be problematic owing to instrument noise, flow fluctuations, and spatial variability. As part of a riverine field experiment conducted in the Kootenai River, ID in August 2010, a spatial map of the mean horizontal and vertical velocity fields in a 200m wide, 8 m deep, and 0.5m/s meandering reach was obtained using two different AUV platforms: SeaRobotics unmanned surface vehicle (USV) and YSI/OceanServer Technology IVER-II unmanned underwater vehicle (UUV). The USV has dual-propellers navigating with GPS and was able to station-keep to within 1 m for 10 minutes at various locations within the reach in order to obtain the 3-D velocity field. Obtaining a statistically confident estimate of the mean velocity profile requires an appropriate time-interval to average instrument noise and environmental fluctuations. It has been previously proposed that 10 minutes is an adequate time interval when using an ADCP in a river. Preliminary results show that a shorter time interval is adequate, which would allow for increased spatial coverage. The UUV has a station-keeping capability when at the surface, but owing to its single propeller, it operates best by performing slow (0.2-0.35m/s) moving transects. Since the UUV is moving in a system that is spatially non-homogenous, additional errors in the mean velocity profile can be introduced due to spatial variability. An evaluation of the velocity profile quality, current measuring performance and minimum averaging time interval requirements are discussed for each platform, including the appropriate mission planning considerations for riverine observations. In

  15. Design and Fabrication of Nereid-UI: A Remotely Operated Underwater Vehicle for Oceanographic Access Under Ice

    Science.gov (United States)

    Whitcomb, L. L.; Bowen, A. D.; Yoerger, D.; German, C. R.; Kinsey, J. C.; Mayer, L. A.; Jakuba, M. V.; Gomez-Ibanez, D.; Taylor, C. L.; Machado, C.; Howland, J. C.; Kaiser, C. L.; Heintz, M.; Pontbriand, C.; Suman, S.; O'hara, L.

    2013-12-01

    The Woods Hole Oceanographic Institution and collaborators from the Johns Hopkins University and the University of New Hampshire are developing for the Polar Science Community a remotely-controlled underwater robotic vehicle capable of being tele-operated under ice under remote real-time human supervision. The Nereid Under-Ice (Nereid-UI) vehicle will enable exploration and detailed examination of biological and physical environments at glacial ice-tongues and ice-shelf margins, delivering high-definition video in addition to survey data from on board acoustic, chemical, and biological sensors. Preliminary propulsion system testing indicates the vehicle will be able to attain standoff distances of up to 20 km from an ice-edge boundary, as dictated by the current maximum tether length. The goal of the Nereid-UI system is to provide scientific access to under-ice and ice-margin environments that is presently impractical or infeasible. FIBER-OPTIC TETHER: The heart of the Nereid-UI system is its expendable fiber optic telemetry system. The telemetry system utilizes many of the same components pioneered for the full-ocean depth capable HROV Nereus vehicle, with the addition of continuous fiber status monitoring, and new float-pack and depressor designs that enable single-body deployment. POWER SYSTEM: Nereid-UI is powered by a pressure-tolerant lithium-ion battery system composed of 30 Ah prismatic pouch cells, arranged on a 90 volt bus and capable of delivering 15 kW. The cells are contained in modules of 8 cells, and groups of 9 modules are housed together in oil-filled plastic boxes. The power distribution system uses pressure tolerant components extensively, each of which have been individually qualified to 10 kpsi and operation between -20 C and 40 C. THRUSTERS: Nereid-UI will employ eight identical WHOI-designed thrusters, each with a frameless motor, oil-filled and individually compensated, and designed for low-speed (500 rpm max) direct drive. We expect an end

  16. Intelligent Autonomous Aerial Vehicles in the National Airspace Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Unmanned aerial systems (UAS) and, in particular, intelligent, autonomous aircraft operating in the National Airspace (NAS) have the potential to significantly...

  17. Analysis of hydrodynamic characteristics of unmanned underwater vehicle moving close to the sea bottom

    Directory of Open Access Journals (Sweden)

    Xiao-xu Du

    2014-03-01

    Full Text Available The accurate research on the hydrodynamics of unmanned underwater vehicle (UUV, which moves close to the sea bottom, has a great significance for its maneuverability. The structured grid of the computational models with different distances to the sea bottom and attack angles is generated by Ansys ICEM, and the flow field near the sea bottom is simulated using CFX. The characteristics of the drag, lift, pitching moment influenced by the distance to sea bottom and the attack angle are studied. The result shows that the drag coefficient increases with the decrease of distance, while it increases with the increase of attack angle. There exists attraction force when UUV moves close to the sea bottom, and the attraction force increases with the decrease in distance. The lift coefficient increases with the increase in attack angle. The absolute value of the pitching moment coefficient increases with the decrease in distance and the increase in attack angle.

  18. An electronic interface for a fiber optic tethered unmanned underwater vehicle

    Science.gov (United States)

    Sheakoski, J. R.

    1994-04-01

    As the sophistication of acoustic sensor and communication systems related to unmanned underwater vehicles (UUV) has increased, the requirement for greater volume and higher speed data transfers has emerged. Fiber optic technology provides an effective means for high bandwidth communications with a UUV while minimizing weight and space criteria aboard the UUV. Increase in data transmission speed has permitted real time processing of data on the launch platform when using large high powered computing systems. Maximum system reliability at advanced performance levels can also be realized. By designing and developing a full scale system comprised of the UUV, remote control and command platform, and data handling and routing electronics, fiber optic tethered UUV technology was demonstrated in lab field tests. This three year venture culminated in a series of successful in-water tests that proved the feasibility of fiber optic tethered UUV's and warranted the continuation of research on remotely operated UUV's.

  19. Fault-tolerant Control of Unmanned Underwater Vehicles with Continuous Faults: Simulations and Experiments

    Directory of Open Access Journals (Sweden)

    Qian Liu

    2010-02-01

    Full Text Available A novel thruster fault diagnosis and accommodation method for open-frame underwater vehicles is presented in the paper. The proposed system consists of two units: a fault diagnosis unit and a fault accommodation unit. In the fault diagnosis unit an ICMAC (Improved Credit Assignment Cerebellar Model Articulation Controllers neural network information fusion model is used to realize the fault identification of the thruster. The fault accommodation unit is based on direct calculations of moment and the result of fault identification is used to find the solution of the control allocation problem. The approach resolves the continuous faulty identification of the UV. Results from the experiment are provided to illustrate the performance of the proposed method in uncertain continuous faulty situation.

  20. Tracking Object Existence From an Autonomous Patrol Vehicle

    Science.gov (United States)

    Wolf, Michael; Scharenbroich, Lucas

    2011-01-01

    An autonomous vehicle patrols a large region, during which an algorithm receives measurements of detected potential objects within its sensor range. The goal of the algorithm is to track all objects in the region over time. This problem differs from traditional multi-target tracking scenarios because the region of interest is much larger than the sensor range and relies on the movement of the sensor through this region for coverage. The goal is to know whether anything has changed between visits to the same location. In particular, two kinds of alert conditions must be detected: (1) a previously detected object has disappeared and (2) a new object has appeared in a location already checked. For the time an object is within sensor range, the object can be assumed to remain stationary, changing position only between visits. The problem is difficult because the upstream object detection processing is likely to make many errors, resulting in heavy clutter (false positives) and missed detections (false negatives), and because only noisy, bearings-only measurements are available. This work has three main goals: (1) Associate incoming measurements with known objects or mark them as new objects or false positives, as appropriate. For this, a multiple hypothesis tracker was adapted to this scenario. (2) Localize the objects using multiple bearings-only measurements to provide estimates of global position (e.g., latitude and longitude). A nonlinear Kalman filter extension provides these 2D position estimates using the 1D measurements. (3) Calculate the probability that a suspected object truly exists (in the estimated position), and determine whether alert conditions have been triggered (for new objects or disappeared objects). The concept of a probability of existence was created, and a new Bayesian method for updating this probability at each time step was developed. A probabilistic multiple hypothesis approach is chosen because of its superiority in handling the

  1. RAO-II: an AUV for underwater inspection

    OpenAIRE

    Oliver, G.; Ortiz, A.; Bonin, F.

    2008-01-01

    AIRSUB is a research project funded by the Spanish Ministry of Science and Technology whose aim is to explore the industrial applications of underwater robots. The Systems, Robotics and Vision Group (SRV) from the University of the Balearic Islands (UIB) is responsible for the subproject of cable/pipeline inspection [1]. To this purpose, an Autonomous Underwater Vehicle (AUV) is under development as a platform to test the vision algorithms, control strategies and software ar...

  2. A high speed telemetry data link for an autonomous roving vehicle

    Science.gov (United States)

    Cipolle, D. J.

    1980-01-01

    A data link system used on a prototype autonomous roving vehicle is described. This system provides a means of acquiring, formatting, and transmitting information on board the vehicle to a controlling computer. Included is a statement of requirements and the design philosophy. Additionally, interfacing with the rover systems is discussed, along with the overall performance of the telemetry link.

  3. Design of Embedded System and Data Communication for an Agricultural Autonomous Vehicle

    DEFF Research Database (Denmark)

    Nielsen, Jens F. Dalsgaard; Nielsen, Kirsten Mølgaard; Bendtsen, Jan Dimon

    2005-01-01

    This paper describes an implemented design of an autonomous vehicle used in precision agriculture for weed and crop map construction with special focus on the onboard controlsystem, the embedded system and the datacommunication system. The vehicle is four wheel driven and four wheel steered (eight...

  4. Priority-based coordination of autonomous and legacy vehicles at intersection

    OpenAIRE

    Qian, Xiangjun; Gregoire, Jean; Moutarde, Fabien; De La Fortelle, Arnaud

    2014-01-01

    International audience Recently, researchers have proposed various intersection management techniques that enable autonomous vehicles to cross the intersection without traffic lights or stop signs. In particular, a priority-based coordination system with provable collision-free and deadlock-free features has been presented. In this paper, we extend the priority-based approach to support legacy vehicles without compromising above-mentioned features. We make the hypothesis that legacy vehicl...

  5. Identification of barriers and least cost paths for autonomous vehicle navigation using airborne LIDAR data

    OpenAIRE

    Poudel, Om Prakash

    2007-01-01

    In the past several years, the Defense Advanced Research Projects Agency (DARPA) has sponsored two Grand Challenges, races among autonomous ground vehicles in rural environments. These vehicles must follow a course delineated by Global Positioning System waypoints using no human guidance. Airborne LIDAR data and GIS can play a significant role in identifying barriers and least cost paths for such vehicles. Least cost paths minimize the sum of impedance across a surface. Impedance can be mea...

  6. Trajectory-Based Visual Localization in Underwater Surveying Missions

    OpenAIRE

    Antoni Burguera; Francisco Bonin-Font; Gabriel Oliver

    2015-01-01

    We present a new vision-based localization system applied to an autonomous underwater vehicle (AUV) with limited sensing and computation capabilities. The traditional EKF-SLAM approaches are usually expensive in terms of execution time; the approach presented in this paper strengthens this method by adopting a trajectory-based schema that reduces the computational requirements. The pose of the vehicle is estimated using an extended Kalman filter (EKF), which predicts the vehicle motion by mea...

  7. A Fault-tolerable Control Scheme for an Open-frame Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Huang Hai

    2014-05-01

    Full Text Available Open-frame is one of the major types of structures of Remote Operated Vehicles (ROV because it is easy to place sensors and operations equipment on- board. Firstly, this paper designed a petri-based recurrent neural network (PRFNN to improve the robustness with response to nonlinear characteristics and strong disturbance of an open-frame underwater vehicle. A threshold has been set in the third layer to reduce the amount of calculations and regulate the training process. The whole network convergence is guaranteed with the selection of learning rate parameters. Secondly, a fault tolerance control (FTC scheme is established with the optimal allocation of thrust. Infinity-norm optimization has been combined with 2-norm optimization to construct a bi-criteria primal-dual neural network FTC scheme. In the experiments and simulation, PRFNN outperformed fuzzy neural networks in motion control, while bi-criteria optimization outperformed 2-norm optimization in FTC, which demonstrates that the FTC controller can improve computational efficiency, reduce control errors, and implement fault tolerable thrust allocation.

  8. Detection of Water Hazards for Autonomous Robotic Vehicles

    Science.gov (United States)

    Matthes, Larry; Belluta, Paolo; McHenry, Michael

    2006-01-01

    Four methods of detection of bodies of water are under development as means to enable autonomous robotic ground vehicles to avoid water hazards when traversing off-road terrain. The methods involve processing of digitized outputs of optoelectronic sensors aboard the vehicles. It is planned to implement these methods in hardware and software that would operate in conjunction with the hardware and software for navigation and for avoidance of solid terrain obstacles and hazards. The first method, intended for use during the day, is based on the observation that, under most off-road conditions, reflections of sky from water are easily discriminated from the adjacent terrain by their color and brightness, regardless of the weather and of the state of surface waves on the water. Accordingly, this method involves collection of color imagery by a video camera and processing of the image data by an algorithm that classifies each pixel as soil, water, or vegetation according to its color and brightness values (see figure). Among the issues that arise is the fact that in the presence of reflections of objects on the opposite shore, it is difficult to distinguish water by color and brightness alone. Another issue is that once a body of water has been identified by means of color and brightness, its boundary must be mapped for use in navigation. Techniques for addressing these issues are under investigation. The second method, which is not limited by time of day, is based on the observation that ladar returns from bodies of water are usually too weak to be detected. In this method, ladar scans of the terrain are analyzed for returns and the absence thereof. In appropriate regions, the presence of water can be inferred from the absence of returns. Under some conditions in which reflections from the bottom are detectable, ladar returns could, in principle, be used to determine depth. The third method involves the recognition of bodies of water as dark areas in short

  9. Application of A* Algorithm for Real-time Path Re-planning of an Unmanned Surface Vehicle Avoiding Underwater Obstacles

    Institute of Scientific and Technical Information of China (English)

    Thanapong Phanthong; Toshihiro Maki; Tamaki Ura; Takashi Sakamaki; Pattara Aiyarak

    2014-01-01

    This paper describes path re-planning techniques and underwater obstacle avoidance for unmanned surface vehicle (USV) based on multi-beam forward looking sonar (FLS). Near-optimal paths in static and dynamic environments with underwater obstacles are computed using a numerical solution procedure based on an A*algorithm. The USV is modeled with a circular shape in 2 degrees of freedom (surge and yaw). In this paper, two-dimensional (2-D) underwater obstacle avoidance and the robust real-time path re-planning technique for actual USV using multi-beam FLS are developed. Our real-time path re-planning algorithm has been tested to regenerate the optimal path for several updated frames in the field of view of the sonar with a proper update frequency of the FLS. The performance of the proposed method was verified through simulations, and sea experiments. For simulations, the USV model can avoid both a single stationary obstacle, multiple stationary obstacles and moving obstacles with the near-optimal trajectory that are performed both in the vehicle and the world reference frame. For sea experiments, the proposed method for an underwater obstacle avoidance system is implemented with a USV test platform. The actual USV is automatically controlled and succeeded in its real-time avoidance against the stationary undersea obstacle in the field of view of the FLS together with the Global Positioning System (GPS) of the USV.

  10. Development of Nereid-UI: A Remotely Operated Underwater Vehicle for Oceanographic Access Under Ice

    Science.gov (United States)

    Whitcomb, L. L.; Bowen, A.; Yoerger, D. R.; German, C. R.; Kinsey, J. C.; Mayer, L. A.; Jakuba, M.; Gomez-Ibanez, D.; Taylor, C. L.; Machado, C.; Howland, J. C.; Kaiser, C. L.; Heintz, M.

    2012-12-01

    The Woods Hole Oceanographic Institution and collaborators from the Johns Hopkins University and the University of New Hampshire are developing a remotely-controlled underwater robotic vehicle to provide the Polar Research Community with a capability to be tele-operated under ice under direct real-time human supervision. The Nereid Under-Ice (Nereid-UI) vehicle, Figure 1, will enable exploration and detailed examination of biological and physical environments at glacial ice-tongues and ice-shelf margins through the use of HD video in addition to acoustic, chemical, and biological sensors, Table 1. We anticipate propulsion system optimization that will enable us to attain distances up to 20 km from an ice-edge boundary, as dictated by the current maximum tether length. The goal of the Nereid-UI system is to provide scientific access to under-ice and ice-margin environments that is presently impractical or infeasible. The project design phase is underway, with incremental field testing planned in 2014. We welcome input from the Polar Science Community on how best to serve your scientific objectives. The Nereid-UI vehicle will employ technology developed during the Nereus HROV project including lightweight expendable tethers and tolerance of communications failures. Performance goals include: 1. Extreme horizontal and vertical mobility - access to under-ice crevasses and glacier grounding- lines, close inspection and mapping. 2. Real-time exploration under direct human control. 3. Response to features of interest by altering sensing modality and trajectory as desired 4. Access to the calving front 5. Access to the under-ice boundary layer 6. Future manipulation, sample retrieval, and instrument emplacement capability Supported by NSF OPP under ANT-1126311, James Family Foundation, George Frederick Jewett Foundation East, and the Woods Hole Oceanographic Institution Fig. 1: Nereid-UI Concept of Operations. Table 1: Nereid-UI Specifications;

  11. Adaptive Surveying and Early Treatment of Crops with a Team of Autonomous Vehicles

    DEFF Research Database (Denmark)

    Kazmi, Wajahat; Bisgaard, Morten; Garcia-Ruiz, Francisco;

    2011-01-01

    The ASETA project (acronym for Adaptive Surveying and Early treatment of crops with a Team of Autonomous vehicles) is a multi-disciplinary project combining cooperating airborne and ground-based vehicles with advanced sensors and automated analysis to implement a smart treatment of weeds in agric......The ASETA project (acronym for Adaptive Surveying and Early treatment of crops with a Team of Autonomous vehicles) is a multi-disciplinary project combining cooperating airborne and ground-based vehicles with advanced sensors and automated analysis to implement a smart treatment of weeds...... system (UAS) and unmanned ground vehicles (UGV) with advanced vision sensors for 3D and multispectral imaging. This paper presents the scientific and technological challenges in the project, which include multivehicle estimation and guidance, heterogeneous multi-agent systems, task generation...... and allocation, remote sensing and 3D computer vision....

  12. Evaluation of the added mass for a spheroid-type unmanned underwater vehicle by vertical planar motion mechanism test

    Science.gov (United States)

    Lee, Seong-Keon; Joung, Tae-Hwan; Cheon, Se-Jong; Jang, Taek-Soo; Lee, Jeong-Hee

    2011-09-01

    This paper shows added mass and inertia can be acquired from the pure heaving motion and pure pitching motion respectively. A Vertical Planar Motion Mechanism (VPMM) test for the spheroid-type Unmanned Underwater Vehicle (UUV) was compared with a theoretical calculation and Computational Fluid Dynamics (CFD) analysis in this paper. The VPMM test has been carried out at a towing tank with specially manufactured equipment. The linear equations of motion on the vertical plane were considered for theoretical calculation, and CFD results were obtained by commercial CFD package. The VPMM test results show good agreement with theoretical calculations and the CFD results, so that the applicability of the VPMM equipment for an underwater vehicle can be verified with a sufficient accuracy.

  13. Motion planning for autonomous vehicle based on radial basis function neural network in unstructured environment.

    Science.gov (United States)

    Chen, Jiajia; Zhao, Pan; Liang, Huawei; Mei, Tao

    2014-01-01

    The autonomous vehicle is an automated system equipped with features like environment perception, decision-making, motion planning, and control and execution technology. Navigating in an unstructured and complex environment is a huge challenge for autonomous vehicles, due to the irregular shape of road, the requirement of real-time planning, and the nonholonomic constraints of vehicle. This paper presents a motion planning method, based on the Radial Basis Function (RBF) neural network, to guide the autonomous vehicle in unstructured environments. The proposed algorithm extracts the drivable region from the perception grid map based on the global path, which is available in the road network. The sample points are randomly selected in the drivable region, and a gradient descent method is used to train the RBF network. The parameters of the motion-planning algorithm are verified through the simulation and experiment. It is observed that the proposed approach produces a flexible, smooth, and safe path that can fit any road shape. The method is implemented on autonomous vehicle and verified against many outdoor scenes; furthermore, a comparison of proposed method with the existing well-known Rapidly-exploring Random Tree (RRT) method is presented. The experimental results show that the proposed method is highly effective in planning the vehicle path and offers better motion quality. PMID:25237902

  14. Motion Planning for Autonomous Vehicle Based on Radial Basis Function Neural Network in Unstructured Environment

    Directory of Open Access Journals (Sweden)

    Jiajia Chen

    2014-09-01

    Full Text Available The autonomous vehicle is an automated system equipped with features like environment perception, decision-making, motion planning, and control and execution technology. Navigating in an unstructured and complex environment is a huge challenge for autonomous vehicles, due to the irregular shape of road, the requirement of real-time planning, and the nonholonomic constraints of vehicle. This paper presents a motion planning method, based on the Radial Basis Function (RBF neural network, to guide the autonomous vehicle in unstructured environments. The proposed algorithm extracts the drivable region from the perception grid map based on the global path, which is available in the road network. The sample points are randomly selected in the drivable region, and a gradient descent method is used to train the RBF network. The parameters of the motion-planning algorithm are verified through the simulation and experiment. It is observed that the proposed approach produces a flexible, smooth, and safe path that can fit any road shape. The method is implemented on autonomous vehicle and verified against many outdoor scenes; furthermore, a comparison of proposed method with the existing well-known Rapidly-exploring Random Tree (RRT method is presented. The experimental results show that the proposed method is highly effective in planning the vehicle path and offers better motion quality.

  15. Online learning-based robust visual tracking for autonomous landing of Unmanned Aerial Vehicles

    OpenAIRE

    Fu, Changhong; Carrio Fernández, Adrián; Olivares Méndez, Miguel Ángel; Campoy Cervera, Pascual

    2014-01-01

    Autonomous landing is a challenging and important technology for both military and civilian applications of Unmanned Aerial Vehicles (UAVs). In this paper, we present a novel online adaptive visual tracking algorithm for UAVs to land on an arbitrary field (that can be used as the helipad) autonomously at real-time frame rates of more than twenty frames per second. The integration of low-dimensional subspace representation method, online incremental learning approach and hierarchical tracking ...

  16. Underwater Environment SDAP Method Using Multi Single-Beam Sonars

    Directory of Open Access Journals (Sweden)

    Zheping Yan

    2013-01-01

    Full Text Available A new autopilot system for unmanned underwater vehicle (UUV using multi-single-beam sonars is proposed for environmental exploration. The proposed autopilot system is known as simultaneous detection and patrolling (SDAP, which addresses two fundamental challenges: autonomous guidance and control. Autonomous guidance, autonomous path planning, and target tracking are based on the desired reference path which is reconstructed from the sonar data collected from the environmental contour with the predefined safety distance. The reference path is first estimated by using a support vector clustering inertia method and then refined by Bézier curves in order to satisfy the inertia property of the UUV. Differential geometry feedback linearization method is used to guide the vehicle entering into the predefined path while finite predictive stable inversion control algorithm is employed for autonomous target approaching. The experimental results from sea trials have demonstrated that the proposed system can provide satisfactory performance implying its great potential for future underwater exploration tasks.

  17. Transverse oscillations of an underwater beam-cable system

    OpenAIRE

    Blanco, Max; Wilson, P.A.

    2010-01-01

    An Autonomous Underwater Vehicle refuel station is proposed. The power source is located on board a surface vessel, while the AUV is serviced at depth. The structure which connects the two craft is modelled as a cable-beam. Transverse oscillations of this cable-beam system are investigated through a fourth-order differential equation.

  18. Underwater terrain positioning method based on least squares estimation for AUV

    Science.gov (United States)

    Chen, Peng-yun; Li, Ye; Su, Yu-min; Chen, Xiao-long; Jiang, Yan-qing

    2015-12-01

    To achieve accurate positioning of autonomous underwater vehicles, an appropriate underwater terrain database storage format for underwater terrain-matching positioning is established using multi-beam data as underwater terrainmatching data. An underwater terrain interpolation error compensation method based on fractional Brownian motion is proposed for defects of normal terrain interpolation, and an underwater terrain-matching positioning method based on least squares estimation (LSE) is proposed for correlation analysis of topographic features. The Fisher method is introduced as a secondary criterion for pseudo localization appearing in a topographic features flat area, effectively reducing the impact of pseudo positioning points on matching accuracy and improving the positioning accuracy of terrain flat areas. Simulation experiments based on electronic chart and multi-beam sea trial data show that drift errors of an inertial navigation system can be corrected effectively using the proposed method. The positioning accuracy and practicality are high, satisfying the requirement of underwater accurate positioning.

  19. Parametric geometric model and shape optimization of an underwater glider with blended-wing-body

    OpenAIRE

    Sun Chunya; Song Baowei; Wang Peng

    2015-01-01

    Underwater glider, as a new kind of autonomous underwater vehicles, has many merits such as long-range, extended-duration and low costs. The shape of underwater glider is an important factor in determining the hydrodynamic efficiency. In this paper, a high lift to drag ratio configuration, the Blended-Wing-Body (BWB), is used to design a small civilian under water glider. In the parametric geometric model of the BWB underwater glider, the planform is defined with Bezier curve and linear line,...

  20. Inter-Vehicle Communication System Utilizing Autonomous Distributed Transmit Power Control

    Science.gov (United States)

    Hamada, Yuji; Sawa, Yoshitsugu; Goto, Yukio; Kumazawa, Hiroyuki

    In ad-hoc network such as inter-vehicle communication (IVC) system, safety applications that vehicles broadcast the information such as car velocity, position and so on periodically are considered. In these applications, if there are many vehicles broadcast data in a communication area, congestion incurs a problem decreasing communication reliability. We propose autonomous distributed transmit power control method to keep high communication reliability. In this method, each vehicle controls its transmit power using feed back control. Furthermore, we design a communication protocol to realize the proposed method, and we evaluate the effectiveness of proposed method using computer simulation.

  1. 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.

  2. Insect-Based Vision for Autonomous Vehicles: A Feasibility Study

    Science.gov (United States)

    Srinivasan, Mandyam V.

    1999-01-01

    The aims of the project were to use a high-speed digital video camera to pursue two questions: (1) To explore the influence of temporal imaging constraints on the performance of vision systems for autonomous mobile robots; (2) To study the fine structure of insect flight trajectories in order to better understand the characteristics of flight control, orientation and navigation.

  3. Diagnosis for Control and Decision Support for Autonomous Vehicles

    DEFF Research Database (Denmark)

    Blanke, Mogens; Hansen, Søren; Rufus Blas, Morten

    2016-01-01

    are reliable in practise. Yet they are also affordable due to the use of fault-tolerant philosophies and tools that make engineering efforts minimal for their implementation. The chapter includes examples for an autonomous aircraft and a baling system for agriculture to illustrate the generic design...

  4. Autonomous taxis could greatly reduce greenhouse-gas emissions of US light-duty vehicles

    Science.gov (United States)

    Greenblatt, Jeffery B.; Saxena, Samveg

    2015-09-01

    Autonomous vehicles (AVs) are conveyances to move passengers or freight without human intervention. AVs are potentially disruptive both technologically and socially, with claimed benefits including increased safety, road utilization, driver productivity and energy savings. Here we estimate 2014 and 2030 greenhouse-gas (GHG) emissions and costs of autonomous taxis (ATs), a class of fully autonomous shared AVs likely to gain rapid early market share, through three synergistic effects: (1) future decreases in electricity GHG emissions intensity, (2) smaller vehicle sizes resulting from trip-specific AT deployment, and (3) higher annual vehicle-miles travelled (VMT), increasing high-efficiency (especially battery-electric) vehicle cost-effectiveness. Combined, these factors could result in decreased US per-mile GHG emissions in 2030 per AT deployed of 87-94% below current conventionally driven vehicles (CDVs), and 63-82% below projected 2030 hybrid vehicles, without including other energy-saving benefits of AVs. With these substantial GHG savings, ATs could enable GHG reductions even if total VMT, average speed and vehicle size increased substantially. Oil consumption would also be reduced by nearly 100%.

  5. Development of a polymer electrolyte membrane fuel cell stack for an underwater vehicle

    Science.gov (United States)

    Han, In-Su; Kho, Back-Kyun; Cho, Sungbaek

    2016-02-01

    This paper presents a polymer electrolyte membrane (PEM) fuel cell stack that is specifically designed for the propulsion of an underwater vehicle (UV). The stack for a UV must be continuously operated in a closed space using hydrogen and pure oxygen; it should meet various performance requirements such as high hydrogen and oxygen utilizations, low hydrogen and oxygen consumptions, a high ramp-up rate, and a long lifetime. To this end, a cascade-type stack design is employed and the cell components, including the membrane electrode assembly and bipolar plate, are evaluated using long-term performance tests. The feasibility of a fabricated 4-kW-class stack was confirmed through various performance evaluations. The proposed cascade-type stack exhibited a high efficiency of 65% and high hydrogen and oxygen utilizations of 99.89% and 99.68%, respectively, resulting in significantly lesser purge-gas emissions to the outside of the stack. The load-following test was successfully performed at a high ramp-up rate. The lifetime of the stack was confirmed by a 3500-h performance test, from which the degradation rate of the cell voltage was obtained. The advantages of the cascade-type stack were also confirmed by comparing its performance with that of a single-stage stack operating in dead-end mode.

  6. Numerical Analysis of the High Skew Propeller of an Underwater Vehicle

    Institute of Scientific and Technical Information of China (English)

    Hassan Ghasseni; Parviz Ghadimi

    2011-01-01

    A numerical analysis based on the boundary element method (BEM) was presented for the hydrodynamic performance of a high skew propeller (HSP) which is employed by an underwater vehicle (UV).Since UVs operate at two different working conditions (surface and submerged conditions),the design of such a propeller is a cumbersome task.This is primarily due to the fact that the resistance forces as well as the vessel efficiency under these conditions are significantly different.Therefore,some factors are necessary for the design of the optimum propeller to utilize the power at the mentioned conditions.The design objectives of the optimum propeller are to obtain the highest possible thrust,minimum torque,and efficiency.In the current study,a 5-bladed HSP was chosen for running the UV.This propeller operated at the stem of the UV hull where the inflow velocity to the propeller was non-uniform.Some parameters of the propeller were predicted based on the UV geometrical hull and operating conditions.The computed results include the pressure distribution and the hydrodynamic characteristics of the HSP in open water conditions,and comparison of these results with those of the experimental data indicates good agreement.The propeller efficiency for both submerged and surface conditions was found to be 67% and 64%,respectively,which compared to conventional propellers is a significantly higher efficiency.

  7. Autonomous Navigation with Constrained Consistency for C-Ranger

    OpenAIRE

    Shujing Zhang; Bo He; Lulu Ying; Minghui Li; Guang Yuan

    2014-01-01

    Autonomous underwater vehicles (AUVs) have become the most widely used tools for undertaking complex exploration tasks in marine environments. Their synthetic ability to carry out localization autonomously and build an environmental map concurrently, in other words, simultaneous localization and mapping (SLAM), are considered to be pivotal requirements for AUVs to have truly autonomous navigation. However, the consistency problem of the SLAM system has been greatly ignored during the past dec...

  8. Investigating the Mobility of Light Autonomous Tracked Vehicles using a High Performance Computing Simulation Capability

    Science.gov (United States)

    Negrut, Dan; Mazhar, Hammad; Melanz, Daniel; Lamb, David; Jayakumar, Paramsothy; Letherwood, Michael; Jain, Abhinandan; Quadrelli, Marco

    2012-01-01

    This paper is concerned with the physics-based simulation of light tracked vehicles operating on rough deformable terrain. The focus is on small autonomous vehicles, which weigh less than 100 lb and move on deformable and rough terrain that is feature rich and no longer representable using a continuum approach. A scenario of interest is, for instance, the simulation of a reconnaissance mission for a high mobility lightweight robot where objects such as a boulder or a ditch that could otherwise be considered small for a truck or tank, become major obstacles that can impede the mobility of the light autonomous vehicle and negatively impact the success of its mission. Analyzing and gauging the mobility and performance of these light vehicles is accomplished through a modeling and simulation capability called Chrono::Engine. Chrono::Engine relies on parallel execution on Graphics Processing Unit (GPU) cards.

  9. Visual Control of Autonomous Vehicle by Neural Networks Using Fuzzy-Supervised Learning

    Energy Technology Data Exchange (ETDEWEB)

    Ryoo, Young Jae [Kumho Information and Telecommunications Laboratory, Kwangju (Korea, Republic of); Lim, Young Cheol [Cheonnam National University, Kwangju (Korea, Republic of)

    1997-04-01

    This paper describes a control scheme for an autonomous vehicle with visual sensors, which uses visual information to guide itself along roadways. The control system integrates visual data into the steering servo process directly, instead of subdividing the process by geometric reasoning for a vehicle-centered representation of the road from two-dimensional visual image data. A neural network using fuzzy-supervised learning is used for determining the steering angle required to move the vanishing point and vanishing line of the road to the desired position in the camera image. The validity and the effectiveness of the proposed control scheme are confirmed by a computer simulation of the autonomous vehicle`s driving performance. (author). 12 refs., 8 figs., 4 tabs.

  10. A Localization Solution for an Autonomous Vehicle in an Urban Environment

    OpenAIRE

    Webster, Jonathan Michael

    2007-01-01

    Localization is an essential part of any autonomous vehicle. In a simple setting, the localization problem is almost trivial, and can be solved sufficiently using simple dead reckoning or an off-the-shelf GPS with differential corrections. However, as the surroundings become more complex, so does the localization problem. The urban environment is a prime example of a situation in which a vehicle's surroundings complicate the problem of position estimation. The urban setting is marked by t...

  11. An image based dynamic window approach for local navigation of an autonomous vehicle in urban environments

    OpenAIRE

    Alves De Lima, Danilo; Corrêa Victorino, Alessandro

    2014-01-01

    This paper presents a local navigation strategy for autonomous vehicles in urban environments with an Image Based Dynamic Window Approach (IDWA). Differently from the global navigation techniques, which requires the vehicle localization to perform its movement, the focus here was to solve the navigation problem in local navigation steps. For that, the environment features will be used, performing the road lane following e.g. The DWA performs a reactive obstacle avoidance while trying to reach...

  12. A Path Tracking Algorithm Using Future Prediction Control with Spike Detection for an Autonomous Vehicle Robot

    Directory of Open Access Journals (Sweden)

    Muhammad Aizzat Zakaria

    2013-08-01

    Full Text Available Trajectory tracking is an important aspect of autonomous vehicles. The idea behind trajectory tracking is the ability of the vehicle to follow a predefined path with zero steady state error. The difficulty arises due to the nonlinearity of vehicle dynamics. Therefore, this paper proposes a stable tracking control for an autonomous vehicle. An approach that consists of steering wheel control and lateral control is introduced. This control algorithm is used for a non-holonomic navigation problem, namely tracking a reference trajectory in a closed loop form. A proposed future prediction point control algorithm is used to calculate the vehicle’s lateral error in order to improve the performance of the trajectory tracking. A feedback sensor signal from the steering wheel angle and yaw rate sensor is used as feedback information for the controller. The controller consists of a relationship between the future point lateral error, the linear velocity, the heading error and the reference yaw rate. This paper also introduces a spike detection algorithm to track the spike error that occurs during GPS reading. The proposed idea is to take the advantage of the derivative of the steering rate. This paper aims to tackle the lateral error problem by applying the steering control law to the vehicle, and proposes a new path tracking control method by considering the future coordinate of the vehicle and the future estimated lateral error. The effectiveness of the proposed controller is demonstrated by a simulation and a GPS experiment with noisy data. The approach used in this paper is not limited to autonomous vehicles alone since the concept of autonomous vehicle tracking can be used in mobile robot platforms, as the kinematic model of these two platforms is similar.

  13. Routing Autonomous Vehicles in Congested Transportation Networks: Structural Properties and Coordination Algorithms

    OpenAIRE

    Zhang, Rick; Rossi, Federico; Pavone, Marco

    2016-01-01

    This paper considers the problem of routing and rebalancing a shared fleet of autonomous (i.e., self-driving) vehicles providing on-demand mobility within a capacitated transportation network, where congestion might disrupt throughput. We model the problem within a network flow framework and show that under relatively mild assumptions the rebalancing vehicles, if properly coordinated, do not lead to an increase in congestion (in stark contrast to common belief). From an algorithmic standpoint...

  14. Path Following of Autonomous Vehicle in 2D Space Using Multivariable Sliding Mode Control

    OpenAIRE

    Daxiong Ji; Jian Liu; Hongyu Zhao; Yiqun Wang

    2014-01-01

    A solution to the path following problem for underactuated autonomous vehicles in the presence of possibly large modeling parametric uncertainty is proposed. For a general class of vehicles moving in 2D space, we demonstrated a path following control law based on multiple variable sliding mode that yields global boundedness and convergence of the position tracking error to a small neighborhood and robustness to parametric modeling uncertainty. An error integration element is added into the “t...

  15. DESIGN AND OPTIMIZATION OF BACKSTEPPING CONTROLLER FOR AN UNDERACTUATED AUTONOMOUS QUADROTOR UNMANNED AERIAL VEHICLE

    OpenAIRE

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

    2014-01-01

    The development of a high performance controller for a quadrotor unmanned aerial vehicle (UAV) is a challenging issue since a quadrotor is an underactuated and a highly unstable nonlinear system. In this paper, the contribution is focused on the design and optimization of a controller for an autonomous quadrotor UAV. Firstly, the dynamic model of the aerial vehicle is mathematically formulated. Then, an optimal backstepping controller (OBC) is proposed. Conventionally, control parameters of a...

  16. GRank -An Information-Centric Autonomous and Distributed Ranking of Popular Smart Vehicles

    OpenAIRE

    Khan, Junaid Ahmed; Ghamri-Doudane, Yacine; Botvich, Dmitri

    2015-01-01

    International audience Modern cars are transforming towards autonomous cars capable to make intelligent decisions to facilitate our travel comfort and safety. Such " Smart Vehicles " are equipped with various sensor platforms and cameras that are capable to constantly sense tremendous amount of heterogeneous data from urban streets. This paper aims to identify the appropriate vehicles, important to be selected as information hubs for the efficient collection, storage and distribution of su...

  17. Study of a Shared Autonomous Vehicles Based Mobility Solution in Stockholm

    OpenAIRE

    Rigole, Pierre-Jean

    2014-01-01

    The aim of this report is to provide an analysis of potential benefits of a fleet of Shared Autonomous Vehicles (SAV) providing a taxi service to replace private car commuter trips in a metropolitan area. We develop a framework for dynamic allocation of SAVs to passenger trips, empty-vehicle routing and multi-criteria evaluation with regard to passenger waiting time, trip time and fleet size. Using a representation of current private trip demand for the Stockholm metropolitan area and a detai...

  18. 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.

  19. Integrating Perception and Planning for Autonomous Navigation of Urban Vehicles

    OpenAIRE

    Benenson, Rodrigo; Petti, Stéphane; Parent, Michel,; Fraichard, Thierry

    2006-01-01

    The paper addresses the problem of autonomous navigation of a car-like robot evolving in an urban environment. Such an environment exhibits an heterogeneous geometry and is cluttered with moving obstacles. Furthermore, in this context, motion safety is a critical issue. The proposed approach to the problem lies in the coupling of two crucial robotic capabilities, namely perception and planning. The main contributions of this work are the development and integration of these modules into one s...

  20. Model Reference Adaptive Backstepping Control of an Autonomous Ground Vehicle

    OpenAIRE

    Quaiyum, Labiba

    2016-01-01

    With an increased push for commercial autonomous cars, the demand of high speed systems capable of performing in unstructured driving environments is growing. In this thesis, the behavior of a bio-inspired predator prey model is considered to stimulate a more organic response to obstacles and a moving target than existing algorithms. However, the current predator prey model has a disconnect between the desired velocities commanded and the torque signals provided to the motors due the dynamics...