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Evaluation of Three Dynamic Ship Positioning Controllers: from Calm to Extreme Conditions

IFAC Proceedings Volumes 2012年第5期45卷 158-163页

作者： Vahid Hassani Asgeir J. Sørensen António M. Pascoal Laboratory of Robotics and Systems in Engineering and Science (LARSyS) Instituto Superior Técnico (IST) Tech. Univ. Lisbon Portugal Centre for Ships and Ocean Structures (CeSOS) and Dept. of Marine Technology Norwegian Univ. of Science and Technology Trondheim Norway

Using Monte-Carlo simulations and experimental model tests, the performance of three controllers designed for dynamic positioning (DP) of marine vessels and offshore rigs subjected to the influence of sea waves, currents, and wind loads is compared for different sea conditions: calm, moderate, high, and extreme seas. The first controller is a nonlinear multivariable PID with a passive observer. The second controller is of the Linear Quadratic Gaussian (LQG) type and the third controller builds on ℋ ∞ control techniques using the mixed-μ synthesis methodology. We further examine the performance of wave filtering of the controllers operating in different sea conditions. The Monte-Carlo simulations highlight the strength of each method as well as its shortcomings and drawbacks.

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Robust Dynamic Positioning of Offshore Vessels using Mixed-μ Synthesis Part I: A Control System Design Methodology

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IFAC Proceedings Volumes 2012年第8期45卷 177-182页

作者： Vahid Hassani Asgeir J. Sørensen António M. Pascoal Laboratory of Robotics and Systems in Engineering and Science (LARSyS) Instituto Superior Téecnico (IST) Tech. Univ. Lisbon Portugal Centre for Ships and Ocean Structures (CeSOS) and Dept. of Marine Technology Norwegian Univ. of Science and Technology Trondheim Norway

This paper describes a procedure to design robust controllers for Dynamic Positioning (DP) of ships and offshore rigs subjected to the influence of sea waves, currents, and wind loads using ℋ ∞ and mixed-μ techniques. To this effect, practical assumptions are exploited in order to obtain a linear design model with parametric uncertainties describing the dynamics of the vessel. Appropriate frequency weighting functions are selected to capture the required performance specifications at the controller design phase. The proposed model and weighting functions are then used to design robust controllers. The problem of wave filtering is also addressed during the process of modeling and controller design. The key contribution of the paper is twofold: i) it affords system designers a new method to efficiently obtain linearized design models that fit naturally in the framework of ℋ ∞ control theory, and ii) it describes, in a systematic manner, the different steps involved in the controller design process. Part II in a companion paper contains the details of simulations and results of experimental model tests in a towing tank equipped with a hydraulic wave maker.

关键词： Robust Control Dynamic Positioning Wave Filtering

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Development of Prosthesis Grasp Control systems on a Robotic Testbed

Development of Prosthesis Grasp Control Systems on a Robotic...

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IEEE RAS & EMBS International Conference on Biomedical robotics and Biomechatronics

作者： Bart Peerdeman Ugo Fabrizi Gianluca Palli Claudio Melchiorri Stefano Stramigioli Sarthak Misra MIRA - Institute for Biomedical Technology and Technical Medicine (Control Engineering Group) University of Twente LAR DEIS - Laboratory of Automation and Robotics Department of Electronics Computer Science and Systems University of Bologna

ISBN: (纸本)9781457711992

Modern myoelectric hand prostheses continue to increase in functionality, while their control is constrained by the limits of myoelectric input. This paper covers the development and testing of grasp control systems for multifunctional myoelectric prosthetic hands. The functionality of modern hand prostheses is often focused on the task of grasping, which can be divided into high-level grasp planning and low-level finger control. Initially, models can used to test these control systems, but for proper evaluation actual implementation on a physical system is required. The University of Bologna (UB) Hand IV prototype is an anthropomorphic, tendon-driven robotic hand, which makes it well-suited to represent the structure of modern prostheses. One of the main control systems tested in this paper is based on the intrinsically passive controller (IPC), the structure of which offers guaranteed passivity and stability. After several grasping tests, the systems are evaluated on compliant behavior, grasping ability, and dynamic appearance. IPC proves to be a powerful approach to interaction control, without the associated sensor requirements which could be difficult to meet in modern hand prostheses.

关键词： Grasp control systems Prosthetic hand Prosthesis robotic hand

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Towards improving mission execution for autonomous gliders with an ocean model and kalman filter

Towards improving mission execution for autonomous gliders w...

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IEEE International Conference on robotics and Automation (ICRA)

作者： Ryan N. Smith Jonathan Kelly Gaurav S. Sukhatme School of Engineering Systems Queensland University of Technology Brisbane QLD Australia Robust Robotics Group Computer Science and Artificial Intelligence Laboratory Massachusetts Institute of Technology Cambridge MA USA Robotic Embedded Systems Laboratory Department of Computer Science University of Southern California Los Angeles CA USA

Effective execution of a planned path by an underwater vehicle is important for proper analysis of the gathered science data, as well as to ensure the safety of the vehicle during the mission. Here, we propose the use of an unscented Kalman filter to aid in determining how the planned mission is executed. Given a set of waypoints that define a planned path and a dicretization of the ocean currents from a regional ocean model, we present an approach to determine the time interval at which the glider should surface to maintain a prescribed tracking error, while also limiting its time on the ocean surface. We assume practical mission parameters provided from previous field trials for the problem set up, and provide the simulated results of the Kalman filter mission planning approach. The results are initially compared to data from prior field experiments in which an autonomous glider executed the same path without pre-planning. Then, the results are validated through field trials with multiple autonomous gliders implementing different surfacing intervals simultaneously while following the same path.

关键词： Navigation Vehicles Sea surface Trajectory Kalman filters Uncertainty

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Complementary terrain/single beacon-based AUV navigation

Complementary terrain/single beacon-based AUV navigation

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3rd IFAC Workshop on Navigation, Guidance and Control of Underwater Vehicles, NGCUV 2012

作者： Maurya, Pramod Teixeira, Francisco Curado Pascoal, António Laboratory for Robotics and Systems in Engineering and Science Instituto Superior Técnico Av. Rovisco Pais 1 1049-001 Lisboa Portugal National Institute of Oceanography Marine Instrumentation Division Dona Paula Goa - 403004 India Center for Environmental and Marine Studies Dept. GeoSciences University of Aveiro Campus Universitário de Santiago 3810-193 Aveiro Portugal

ISBN: (纸本)9783902823199

This paper describes work done towards the development of advanced geophysical-based navigation systems for autonomous underwater vehicles (AUVs). The specific problem that we tackle is that of combining terrain-aided navigation (TAN) with single-beacon navigation (SBN) techniques. The resulting complementary TAN/SBN system has the potential to overcome some of the problems that arise with TAN navigation only, when an AUV undergoes motions that lead it temporarily across areas where the terrain below is not sufficiently "rich" in terms of topographic features. The key contribution of this paper is a formal analysis of the benefits of using complementary filtering, in opposition to TAN navigation only. To this effect, we exploit key tools of estimation theory, and in particular the Cramér-Rao lower bound inequality to obtain a lower bound on the minimum covariance of the estimation error that can be obtained with any unbiased estimator. For a real terrain profile we compute and compare the Cramér-Rao lower bounds for TAN only and TA/SB-based navigation. The increase in the expected performance that can be achieved with the second solution is clearly visible. The efficacy of the new solution proposed is illustrated with the help of computer simulations.

关键词： Monte Carlo methods

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Multiple Model Adaptive Dynamic Positioning

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IFAC Proceedings Volumes 2012年第27期45卷 55-60页

作者： Vahid Hassani Asgeir J. Sørensen António M. Pascoal Nguyen Trong Dong Laboratory of Robotics and Systems in Engineering and Science (LARSyS) Instituto Superior Técnico (IST) Tech. Univ. Lisbon Portugal Centre for Ships and Ocean Structures (CeSOS) and Dept. of Marine Technology Norwegian Univ. of Science and Technology Trondheim Norway Marine Cybernetics Trondheim Norway

This paper describes a procedure to design multiple model adaptive controllers for Dynamic Positioning (DP) of ships and offshore rigs subjected to the influence of sea waves, currents, and wind loads. To this effect, a linear design model is obtained, based on practical assumptions, describing the dynamics of the vessel. Four Linear Quadratic Gaussian (LQG) DP controllers (with the same structure) are designed, covering the different sea conditions from calm to extreme seas. Tools from multiple model adaptive control (MMAC) theory are used to exploit the information provided by the different observers (models) in order to select the appropriate controller. Numerical simulations carried out using a high fidelity nonlinear DP simulator illustrate the efficiency of the MMAC techniques proposed. To bridge the gap between theory and practice, the results of the simulations were experimentally verified by model testing with a DP operated ship, the Cybership III, under different simulated sea conditions in a towing tank equipped with a hydraulic wave maker.

关键词： Adaptive Dynamic Positioning Multiple Model Adaptive Control LQG Dynamic Positioning Controllers

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A novel swarm intelligence algorithm and its application in solving wireless sensor networks coverage problems

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Journal of Networks 2012年第12期7卷 2037-2043页

作者： Mo, Yuanbin Liu, Jizhong Wang, Baolei Jonathan Wu, Q.M. College of Mathematics and Computer Science Guangxi University for Nationalities Nanning 530006 China School of Mechanical and Electrical Engineering Institute of Robotics of Nanchang University Nanchang University Nanchang 330031 China Department of Electrical and Computer Engineering Computer Vision and Sensing Systems Laboratory University of Windsor Windsor N9B3P4 Canada

Wireless sensor networks (WSNs) have attracted a great deal of research due to their wide-range of potential applications. Sensor deployment and coverage problems are their important issues. This article briefly introduces the principle of swarm intelligence (SI). A novel SI algorithm based on information sharing of Particle Swarm Optimization (PSO) and diversity maintenance mechanism of Artificial Immune System (AIS) is designed and the model of coverage problems is given. Its applications in solving different deterministic and random coverage problems are given. The algorithm used in obtaining maximum coverage probability with given number of sensor nodes and minimum number of sensor nodes with required coverage probability of WSNs deterministic coverage, and determining the selected sensor nodes with coverage probability and connectivity requirement of WSNs random coverage, are analyzed in detail. The simulation results show the algorithm is practical. The applications of SI on K- coverage and connectivity problems in the future are also projected in the article. © 2012 ACADEMY PUBLISHER.

关键词： Swarm intelligence

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Overcoming Occlusions in Eye-in-Hand Visual Search

Overcoming Occlusions in Eye-in-Hand Visual Search

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American Control Conference

作者： Sina Radmard David Meger Elizabeth A. Croft James J. Little Collaborative Advanced Robotics and Intelligent Systems Laboratory Mechanical Engineering Department University of British Columbia V6T1Z4 Canada Laboratory for Computational Intelligence Department of Computer Science University of British Columbia V6T1Z4 Canada

ISBN: (纸本)9781457710957

In this paper we propose a method for handling persistent visual occlusions that disrupt visual tracking for eye-in-hand systems. This approach provides an efficient strategy for the robot to "look behind" the occlusion while respecting the robot's physical constraints. Specifically, we propose a decoupled search strategy combining a naive pan tilt search with a sensor placement approach, to reduce the strategy's computational cost. We proceed by mapping limited environmental data into the robot configuration space and then planning within a constrained region. We use a particle filter to continuously estimate the target location, while our configuration-based cost function plans a goal location for the camera frame, taking into account robot singularity, self-collision and joint limit constraints. To validate our algorithm, we implemented it on an eye-in-hand robot system. Experimental results for various situations support the feasibility of our approach for quickly recovering fully occluded moving targets. Finally we discuss the implications of this approach to mobile robot platforms.

关键词： Joints Cameras Robot vision systems Target tracking Planning

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Triangular formation control using range measurements: An application to marine robotic vehicles

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IFAC Proceedings Volumes 2012年第5期45卷 112-117页

作者： Jorge M. Soares A. Pedro Aguiar António M. Pascoal Marco Gallieri Laboratory of Robotics and Systems in Engineering and Science Instituto Superior Técnico Technical University of Lisbon Av. Rovisco Pais 1049-001 Lisboa Portugal School of Architecture Civil and Environmental Engineering École Polytechnique Fédérale de Lausanne (EPFL) CH-1015 Lausanne Switzerland Control Group Engineering Department Sidney Sussex College University of Cambridge CB21PZ Cambridge UK

This paper addresses the problem of maintaining an autonomous robotic vehicle in a moving triangular formation by regulating its position with respect to two leader vehicles. The robotic vehicle has no a priori knowledge of the path described by the leaders and its goal is to follow them by constantly regulating the inter-vehicle distances to a desired fixed value, using range-only measurements. To solve this station keeping problem, we propose a control strategy that estimates the formation speed and heading from the ranges obtained to the two leading vehicles, and uses simple feedback laws for speed and heading commands to drive suitably defined common and differential errors to zero. For straight-line motion, we provide guaranteed conditions under which the proposed control strategy achieves local convergence of the distance errors to zero. We also indicate how our design procedure can be extended to full dynamic models of marine robotic vehicles equipped with inner loops for yaw and speed control. Simulation results using realistic models are described and discussed.

关键词： Autonomous Vehicles Marine systems Control Laws Lyapunov Stability Formation Control Station Keeping Triangular Formations

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Reports of the AAAI 2011 conference workshops

Reports of the AAAI 2011 conference workshops

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作者： Agmon, Noa Agrawal, Vikas Aha, David W. Aloimonos, Yiannis Buckley, Donagh Doshi, Prashant Geib, Christopher Grasso, Floriana Green, Nancy Johnston, Benjamin Kaliski, Burt Kiekintveld, Christopher Law, Edith Lieberman, Henry Mengshoel, Ole J. Metzler, Ted Modayil, Joseph Oard, Douglas W. Onder, Nilufer O'Sullivan, Barry Pastra, Katerina Precup, Doina Ramachandran, Sowmya Reed, Chris Sariel-Talay, Sanem Selker, Ted Shastri, Lokendra Singh, Satinder Smith, Stephen F. Srivastava, Siddharth Sukthankar, Gita Uthus, David C. Williams, Mary-Anne Department of Computer Science University of Texas at Austin United States Center for Knowledge Driven Information Systems Infosys Labs India Adaptive Systems Section Naval Research Laboratory Washington DC United States Department of Computer Science University of Maryland College Park United States EMC's Center of Excellence in Ireland Research Europe at EMC Ireland Department of Computer Science University of Georgia United States School of Informatics University of Edinburgh United Kingdom Department of Computer Science University of Liverpool United Kingdom Department of Computer Science University of North Carolina Greensboro United States Faculty of Engineering and Information Technology University of Technology Sydney Australia VeriSign Inc. United States Department of Computer Science University of Texas at El Paso United States Machine Learning Department Carnegie Mellon University United States Massachusetts Institute of Technology Media Laboratory United States Carnegie Mellon University's Silicon Valley Campus United States Darrell W. Hughes Program for Religion and Science Dialogue Oklahoma City University United States Department of Computing Science University of Alberta Canada College of Information Studies Institute for Advanced Computer Studies University of Maryland College Park United States Department of Computer Science Michigan Technological University United States Department of Computer Science University College Cork Ireland Cognitive Systems Research Insitute Athens Greece School of Computer Science McGill University Canada Stottler Henke Inc. United States School of Computing University of Dundee United Kingdom Department of Computer Engineering Istanbul Technical University Turkey Convergence Lab Infosys Technologies Ltd. United States Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor United States Robotics Institute Carnegie Mellon University United States University of Wisconsin

The AAAI-11 workshop program was held Sunday and Monday, August 7-18, 2011, at the Hyatt Regency San Francisco in San Francisco, California USA. The AAAI-11 workshop program included 15 workshops covering a wide range of topics in artificial intelligence. The titles of the workshops were Activity Context Representation: Techniques and Languages;Analyzing Microtext;Applied Adversarial Reasoning and Risk Modeling;Artificial Intelligence and Smarter Living: The Conquest of Complexity;Artifiicial Intelligence for Data Center Management and Cloud Computing;Automated Action Planning for Autonomous Mobile Robots;Computational Models of Natural Argument;Generalized Planning;Human Computation;Human-Robot Interaction in Elder Care;Interactive Decision Theory and Game Theory, 2010;Language-Action Tools for Cognitive Artificial Agents: Integrating Vision, Action, and Language;Lifelong Learning from Sensorimotor Experience;Plan, Activity, and Intent Recognition;and Scalable Integration of Analytics and Visualization. This article presents short summaries of those events. Copyright © 2012, Association for the Advancement of Artificial Intelligence. All rights reserved.

关键词： Human robot interaction

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