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Resulting Closed-loop System (resulting + closed-loop_system)
Selected AbstractsAdaptive tracking control for electrically-driven robots without overparametrizationINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 2 2002Yeong-Chan Chang Abstract This paper addresses the motion tracking control of robot systems actuated by brushed direct current motors in the presence of parametric uncertainties and external disturbances. By using the integrator backstepping technique, two kinds of adaptive control schemes are developed: one requires the measurements of link position, link velocity and armature current for feedback and the other requires only the measurements of link position and armature current for feedback. The developed adaptive controllers guarantee that the resulting closed-loop system is locally stable, all the states and signals are bounded, and the tracking error can be made as small as possible. The attraction region can be not only arbitrarily preassigned but also explicitly constructed. The main novelty of the developed adaptive control laws is that the number of parameter estimates is exactly equal to the number of unknown parameters throughout the entire electromechanical system. Consequently, the phenomenon of overparametrization, a significant drawback of employing the integrator backstepping technique to treat the control of electrically driven robots in the previous literature, is eliminated in this study. Finally, simulation examples are given to illustrate the tracking performance of electrically driven robot manipulators with the developed adaptive control schemes. Copyright © 2002 John Wiley & Sons, Ltd. [source] LMI approach to reliable guaranteed cost control with multiple criteria constraints: The actuator faults caseINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 8 2009Dengfeng Zhang Abstract Based on the multi-objective optimization strategy and linear matrix inequality approach, the problem of reliable guaranteed cost control with multiple criteria constraints is investigated for a class of uncertain discrete-time systems subject to actuator faults. A fault model in actuators, which considers outage or partial degradation in independent actuators, is adopted. The quadratic stability is proved to be independent of the disturbance and the upper bound of a quadratic cost index is improved. The reliable feedback controller is designed to minimize the upper bound of the quadratic cost index, place all the closed-loop poles in a specified disk, constrain the H, norm level of the disturbance attenuation into a given range and guarantee the magnitudes of control inputs less than the given bound, as well. Thus, the resulting closed-loop system can provide satisfactory stability, transient behavior, disturbance rejection level and optimized upper bound of the quadratic cost performance despite possible actuator faults. Copyright © 2008 John Wiley & Sons, Ltd. [source] Robust stabilization for uncertain discrete singular systems with state delayINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 16 2008Zhengguang Wu Abstract The robust stabilization problem for uncertain discrete singular time-delay systems is addressed in this paper. In terms of strict linear matrix inequality and a finite sum inequality, a delay-dependent criterion for the nominal systems to be admissible is obtained. Based on the criterion, a state feedback controller, which guarantees that, for all admissible uncertainties, the resulting closed-loop system is regular, causal and stable, is constructed. An explicit expression for the desired controller is also given. The obtained results include both delay-independent and delay-dependent cases. Some numerical examples are introduced to show the effectiveness of the given results. Copyright © 2008 John Wiley & Sons, Ltd. [source] A new finite sum inequality approach to delay-dependent H, control of discrete-time systems with time-varying delayINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 6 2008Xian-Ming Zhang Abstract This paper deals with delay-dependent H, control for discrete-time systems with time-varying delay. A new finite sum inequality is first established to derive a delay-dependent condition, under which the resulting closed-loop system via a state feedback is asymptotically stable with a prescribed H, noise attenuation level. Then, an iterative algorithm involving convex optimization is proposed to obtain a suboptimal H, controller. Finally, two numerical examples are given to show the effectiveness of the proposed method. Copyright © 2007 John Wiley & Sons, Ltd. [source] Omega-limit sets of a class of nonlinear systems that are semiglobally practically stabilizedINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 7 2005Christopher I. Byrnes Abstract In nonlinear control theory, the equilibrium of a system is semiglobally practically stabilizable if, given two balls centred at the equilibrium, one of arbitrarily large radius and one of arbitrarily small radius, it is possible to design a feedback so that the resulting closed-loop system has the following property: all the trajectories originating in the large ball enter into the small ball and stay inside thereafter. In this work, given certain classes of nonlinear systems that are semiglobally practically stabilized, we focus on the problem of characterizing the structure of the omega-limit set that attracts the trajectories that start inside the large ball. Copyright © 2005 John Wiley & Sons, Ltd. [source] Robust H, control for uncertain singular systems with state delayINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 13 2003Shengyuan Xu Abstract This paper addresses the problem of robust H, control for uncertain continuous singular systems with state delay. The singular system under consideration involves state time delay and time-invariant norm-bounded uncertainty. Based on the linear matrix inequality (LMI) approach, we design a memoryless state feedback controller law, which guarantees that, for all admissible uncertainties, the resulting closed-loop system is not only regular, impulse free and stable, but also meets an H, -norm bound constraint on disturbance attenuation. A numerical example is provided to demonstrate the applicability of the proposed method. Copyright © 2003 John Wiley & Sons, Ltd. [source] Output feedback stabilization for a class of stochastic non-linear systems with delays in input,ASIAN JOURNAL OF CONTROL, Issue 1 2010Jun-e Feng Abstract In this paper, constructive techniques are developed for a class of stochastic non-linear systems with delays in input. Non-linear terms considered in this paper are more general than those satisfying linear growth conditions. The purpose is to design an output feedback controller such that the resulting closed-loop system is globally asymptotically stable in probability. The desired output feedback controller is explicitly constructed using the Lyapunov method. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source] Delay-dependent robust stabilization for uncertain stochastic switching systems with distributed delays,ASIAN JOURNAL OF CONTROL, Issue 5 2009Hao Shen Abstract This paper deals with the problem of robust stabilization for a class of uncertain stochastic switching systems with distributed delays. The purpose is to design a memory controller, which guarantees that the resulting closed-loop system is mean-square asymptotically stable. In terms of a set of linear matrix inequalities, a delay-dependent condition is proposed and a robust memory controller is designed. Two numerical examples are provided to illustrate the effectiveness of the proposed method. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source] ROBUST STABILITY AND STABILIZATION OF A CLASS OF SINGULAR SYSTEMS WITH MULTIPLE TIME-VARYING DELAYSASIAN JOURNAL OF CONTROL, Issue 1 2006S. M. Saadni ABSTRACT This paper deals with the problem of robust stability and robust stabilization for uncertain continuous singular systems with multiple time-varying delays. The parametric uncertainty is assumed to be norm bounded. The purpose of the robust stability problem is to give conditions such that the uncertain singular system is regular, impulse free, and stable for all admissible uncertainties. The purpose of the robust stabilization problem is to design a feedback control law such that the resulting closed-loop system is robustly stable. This problem is solved via generalized quadratic stability approach. A strict linear matrix inequality (LMI) design approach is developed. Finally, a numerical example is provided to demonstrate the application of the proposed method. [source] Adaptive backstepping control for a class of time delay systems with nonlinear perturbationsINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 3 2008Chang-Chun Hua Abstract The sliding mode control method has been extensively employed to stabilize time delay systems with nonlinear perturbations. Although the resulting closed-loop systems have good transient and steady-state performances, the designed controllers are dependent on the time delays. But one knows that it is difficult to obtain the precise delay time in practical systems, especially when it is time varying. In this paper, we revisit the problem and use the backstepping method to construct the state feedback controller. First, a coordinate transformation is used to obtain a cascade time delay system. Then, a linear virtual control law is designed for the first subsystem. The memoryless controller is further constructed based on adaptive method for the second subsystem with the uncertainties bounded by linear function. By choosing new Lyapunov,Krasovskii functional, we show that the system state converges to zero asymptotically. Via the proposed approach, we also discuss the case that the uncertainties are bounded by nonlinear functions. Finally, simulations are done to verify the effectiveness of the main results obtained. Copyright © 2007 John Wiley & Sons, Ltd. [source] | ||||||||||