The Experts below are selected from a list of 47469 Experts worldwide ranked by ideXlab platform
Tarek Hamel - One of the best experts on this subject based on the ideXlab platform.
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A nonlinear control approach for trajectory tracking of slender-body axisymmetric underactuated Underwater Vehicles
2019 18th European Control Conference (ECC), 2019Co-Authors: Lam-hung Nguyen, Tarek HamelAbstract:This paper develops a novel nonlinear control approach for slender-body underactuated Underwater Vehicles with a body shape symmetric with respect to the longitudinal axis. Compared to aerial Vehicles, added-mass effects are much more preponderant and complex for Underwater Vehicles, especially for slender bodies. By considering an axisymmetric body, these added-mass effects along with dissipative hydrodynamic force are carefully taken into account via various adaptations and decompositions, resulting in a modified “apparent” force independent of the vehicle's orientation and subsequently a nonlinear system with a triangular control structure. The proposed controller is then complemented with an integral correction term so as to enhance its robustness with respect to model uncertainties and external disturbances. Comparative simulation results conducted on a realistic model of a quasi-axisymmetric Underwater vehicle illustrate the performance and robustness of the proposed control approach.
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Pipeline following by visual servoing for Autonomous Underwater Vehicles
Control Engineering Practice, 2019Co-Authors: Guillaume Allibert, Minh-duc Hua, Szymon Krupínski, Tarek HamelAbstract:A nonlinear image-based visual servo control approach for pipeline following of fully-actuated Autonomous Underwater Vehicles (AUV) is proposed. It makes use of the binormalized Plücker coordinates of the pipeline borders detected in the image plane as feedback information while the system dynamics are exploited in a cascade manner in the control design. Unlike conventional solutions that consider only the system kinematics, the proposed control scheme accounts for the full system dynamics in order to obtain an enlarged provable stability domain. Control robustness with respect to model uncertainties and external disturbances is reinforced using integral corrections. Robustness and efficiency of the proposed approach are illustrated via both realistic simulations and experimental results on a real AUV.
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Homography-based Visual Servoing for Autonomous Underwater Vehicles
2014Co-Authors: Minh-duc Hua, Guillaume Allibert, Szymon Krupínski, Tarek HamelAbstract:A nonlinear visual servoing approach is proposed for the stabilisation of fully-actuated autonomous Underwater Vehicles (AUVs) by exploiting the homography matrix between the two images of a planar scene. In a cascade manner, an outer-loop control defines a reference setpoint based on the homography matrix, and an inner-loop control ensures the stabilisation of the setpoint by assigning thrust and torque controls. In contrast with conventional kinematic solution, the proposed controller deals with the high nonlinearity and coupling of the system dynamics and ensures almost-global asymptotical stability. In addition, the interactions of the AUV with the surrounding fluid (e.g., added mass and drag effects) are often difficult to model precisely whereas they may significantly perturb its motion. The proposed controller –augmented with an effective integral action– allows for the compensation of model uncertainties and for robust performance against such perturbations. Simulation results illustrating these properties on a realistic AUV model subject to sea current are reported.
Aníbal C. Matos - One of the best experts on this subject based on the ideXlab platform.
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Tracking multiple Autonomous Underwater Vehicles
Autonomous Robots, 2019Co-Authors: Jose Melo, Aníbal C. MatosAbstract:In this paper we present a novel method for the acoustic tracking of multiple Autonomous Underwater Vehicles. While the problem of tracking a single moving vehicle has been addressed in the literature, tracking multiple Vehicles is a problem that has been overlooked, mostly due to the inherent difficulties on data association with traditional acoustic localization networks. The proposed approach is based on a Probability Hypothesis Density Filter, thus overcoming the data association problem. Our tracker is able not only to successfully estimate the positions of the Vehicles, but also their velocities. Moreover, the tracker estimates are labelled, thus providing a way to establish track continuity of the targets. Using real word data, our method is experimentally validated and the performance of the tracker is evaluated.
M Grund - One of the best experts on this subject based on the ideXlab platform.
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experimental results in synchronous clock one way travel time acoustic navigation for autonomous Underwater Vehicles
International Conference on Robotics and Automation, 2007Co-Authors: Ryan M Eustice, Hanumant Singh, Louis L Whitcomb, M GrundAbstract:This paper reports recent experimental results in the development and deployment of a synchronous-clock acoustic navigation system suitable for the simultaneous navigation of multiple Underwater Vehicles. The goal of this work is to enable the task of navigating multiple autonomous Underwater Vehicles (AUVs) over length scales of O(100 km), while maintaining error tolerances commensurate with conventional long-baseline transponder-based navigation systems (i.e., O(1 m)), but without the requisite need for deploying, calibrating, and recovering seafloor anchored acoustic transponders. Our navigation system is comprised of an acoustic modem-based communication/navigation system that allows for onboard navigational data to be broadcast as a data packet by a source node, and for all passively receiving nodes to be able to decode the data packet to obtain a one-way travel time pseudo-range measurement and ephemeris data. We present results for two different field experiments using a two-node configuration consisting of a global positioning system (GPS) equipped surface ship acting as a global navigation aid to a Doppler-aided AUV. In each experiment, vehicle position was independently corroborated by other standard navigation means. Initial results for a maximum-likelihood sensor fusion framework are reported.
Georgios A. Demetriou - One of the best experts on this subject based on the ideXlab platform.
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Control architectures for autonomous Underwater Vehicles
Control Systems …, 1997Co-Authors: Kimon P. Valavanis, Ramesh Kolluru, Maja Matijasevic, Denis Gracanin, Georgios A. DemetriouAbstract:Autonomous Underwater Vehicles (AUVs) share common control problems with other air, land, and water unmanned Vehicles. In addition to requiring high-dimensional and computationally intensive sensory data for real-time mission execution, power and communication limitations in an Underwater environment make it more difficult to develop a control architecture for an AUV. In this article, the four types of control architectures being used for AUVs (hierarchical, heterarchical, subsumption, and hybrid architecture) are reviewed. A summary of 25 existing AUVs and a review of 11 AUV control architecture systems present a flavor of the state of the art in AUV technology. A new sensor-based embedded AUV control system architecture is also described and its implementation is discussed
Jose Melo - One of the best experts on this subject based on the ideXlab platform.
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Tracking multiple Autonomous Underwater Vehicles
Autonomous Robots, 2019Co-Authors: Jose Melo, Aníbal C. MatosAbstract:In this paper we present a novel method for the acoustic tracking of multiple Autonomous Underwater Vehicles. While the problem of tracking a single moving vehicle has been addressed in the literature, tracking multiple Vehicles is a problem that has been overlooked, mostly due to the inherent difficulties on data association with traditional acoustic localization networks. The proposed approach is based on a Probability Hypothesis Density Filter, thus overcoming the data association problem. Our tracker is able not only to successfully estimate the positions of the Vehicles, but also their velocities. Moreover, the tracker estimates are labelled, thus providing a way to establish track continuity of the targets. Using real word data, our method is experimentally validated and the performance of the tracker is evaluated.
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Survey on advances on terrain based navigation for autonomous Underwater Vehicles
Ocean Engineering, 2017Co-Authors: Jose Melo, Anibal MatosAbstract:The autonomy of robotic Underwater Vehicles is dependent on the ability to perform long-term and long-range missions without need of human intervention. While current state-of-the-art Underwater navigation techniques are able to provide sufficient levels of precision in positioning, they require the use of support vessels or acoustic beacons. This can pose limitations on the size of the survey area, but also on the whole cost of the operations. Terrain Based Navigation is a sensor-based navigation technique that bounds the error growth of dead-reckoning using a map with terrain information, provided that there is enough terrain variability. An obvious advantage of Terrain Based Navigation is the fact that no external aiding signals or devices are required. Because of this unique feature, terrain navigation has the potential to dramatically improve the autonomy of Autonomous Underwater Vehicles (AUVs). This paper consists on a comprehensive survey on the recent developments for Terrain Based Navigation methods proposed for AUVs. The survey includes a brief introduction to the original Terrain Based Navigation formulations, as well as a description of the algorithms, and a list of the different implementation alternatives found in the literature. Additionally, and due to the relevance, Bathymetric SLAM techniques will also be discussed.
