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Closed-loop Dynamics (closed-loop + dynamics)

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Selected Abstracts

Controlled Lagrangians and the stabilization of Euler,Poincaré mechanical systems

INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 3 2001
Anthony M. Bloch
Abstract In this paper we develop a constructive approach to the determination of stabilizing control laws for a class of Lagrangian mechanical systems with symmetry , systems whose underlying dynamics are governed by the Euler,Poincaré equations. This work extends our previous work on the stabilization of mechanical control systems using the method of controlled Lagrangians. The guiding principle behind our methodology is to develop a class of stabilizing feedback control laws which yield closed-loop dynamics that remain in Lagrangian form. Using the methodology for Euler,Poincaré systems, we analyse stabilization of a satellite and an underwater vehicle controlled with momentum wheels. Copyright © 2001 John Wiley & Sons, Ltd. [source]

A natural redundancy-resolution for 3-D multi-joint reaching under the gravity effect

JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 11 2005
Masahiro Sekimoto
A simple control method for 3-dimensional multi-joint reaching movements under redundancy of degrees of freedom (DOF) is proposed, which need neither introduce any performance index to solve inverse kinematics uniquely nor calculate pseudo-inverse of the Jacobian matrix of task coordinates with respect to joint coordinates. The proposed control signal is composed of linear superposition of three terms: (1) angular-velocity feedback for damping shaping, (2) task-space position error feedback with a single stiffness parameter, and (3) compensation for gravity force on the basis of estimates for uncertain parameters of the potential energy without calculation any inverse joint position to the target in task space. Through a theoretical analysis of the closed-loop dynamics and a variety of computer simulations by using a whole arm model with five DOFs, the importance of synergistic adjustments of damping factors as well as its relation to selection of the stiffness parameter is pointed out. It is shown that if damping factors are chosen synergistically corresponding to the inertia matrix at the initial time and the stiffness parameter then the endpoint converges asymptotically to the target position and reaches it smoothly without incurring any self-motion. © 2005 Wiley Periodicals, Inc. [source]

A novel adaptive bilateral control scheme using similar closed-loop dynamic characteristics of master/slave manipulators

JOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 9 2001
Jee-Hwan Ryu
This article presents a novel adaptive bilateral control scheme for obtaining ideal responses for teleoperation systems with uncertainties. A condition that is equivalent to getting an ideal response in teleoperation has been found to be making the closed-loop dynamics of master and slave manipulators a similar form. An adaptive approach is applied to achieve similarity for the uncertain master and slave manipulators. Using the similar closed-loop dynamic characteristics of master/slave teleoperation systems, excellent position and force tracking performance has been obtained without estimating the impedance of human and environment. The validity of the theoretical results is verified by experiments. © 2001 John Wiley & Sons, Inc. [source]

Optimal guaranteed cost for singular linear systems with random abrupt changes

OPTIMAL CONTROL APPLICATIONS AND METHODS, Issue 4 2010
El-Kébir Boukas
Abstract This paper considers the class of continuous-time singular linear Markovian jump systems with totally and partially known transition jump rates. The guaranteed cost control problem of this class of systems is tackled. New sufficient conditions for optimal guaranteed cost are developed. A design procedure for the guaranteed cost controller, which guarantees that the closed-loop dynamics will be piecewise regular, impulse-free and stochastically stable is proposed. It is shown that the addressed problem can be solved if the corresponding developed linear matrix inequalities (LMIs) with some constraints are feasible. A numerical example is employed to show the usefulness of the proposed results. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Singular linear systems with delay: ,, stabilization

OPTIMAL CONTROL APPLICATIONS AND METHODS, Issue 4 2007
E. K. BoukasArticle first published online: 12 MAR 200
Abstract This paper deals with the class of continuous-time singular linear systems with time-delay in the state vector. The stabilization problem of this class of systems using a state feedback controller is tackled. New delay-dependent sufficient conditions on ,, stabilization are developed. A design algorithm for a memoryless state feedback controller which guarantees that the closed-loop dynamics will be regular, impulse-free and stable with ,-disturbance rejection is proposed. It is shown that the addressed problem can be solved if the corresponding developed linear matrix inequalities (LMIs) with some constraints are feasible. A numerical example is employed to show the usefulness of the proposed results. Copyright © 2007 John Wiley & Sons, Ltd. [source]