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LMI Approach (lmi + approach)
Selected AbstractsAN ITERATIVE LMI APPROACH TO RFDF FOR LINEAR SYSTEM WITH TIME-VARYING DELAYSASIAN JOURNAL OF CONTROL, Issue 1 2006Maiying Zhong ABSTRACT This paper deals with robust fault detection filter (RFDF) problem for a class of linear uncertain systems with time-varying delays and model uncertainties. The RFDF design problem is formulated as an optimization problem by using L2 -induced norm to represent the robustness of residual to unknown inputs and modelling errors, and the sensitivity to faults. A sufficient condition to the solvability of formulated problem is established in terms of certain matrix inequalities, which can be solved with the aid of an iterative linear matrix inequality (ILMI) algorithm. Finally, a numerical example is given to illustrate the effectiveness of the proposed method. [source] LMI APPROACH TO ROBUST FILTERING FOR DISCRETE TIME-DELAY SYSTEMS WITH NONLINEAR DISTURBANCESASIAN JOURNAL OF CONTROL, Issue 2 2005Huijun Gao ABSTRACT This paper investigates the problem of robust filtering for a class of uncertain nonlinear discrete-time systems with multiple state delays. It is assumed that the parameter uncertainties appearing in all the system matrices reside in a polytope, and that the nonlinearities entering into both the state and measurement equations satisfy global Lipschitz conditions. Attention is focused on the design of robust full-order and reduced-order filters guaranteeing a prescribed noise attenuation level in an H, or l2 - l, sense with respect to all energy-bounded noise disturbances for all admissible uncertainties and time delays. Both delay-dependent and independent approaches are developed by using linear matrix inequality (LMI) techniques, which are applicable to systems either with or without a priori information on the size of delays. [source] Gain Scheduled LPV H, Control Based on LMI Approach for a Robotic ManipulatorJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 12 2002Zhongwei Yu A new approach to the design of a gain scheduled linear parameter-varying (LPV) H, controller, which places the closed-loop poles in the region that satisfies the specified dynamic response, for an n -joint rigid robotic manipulator, is presented. The nonlinear time-varying robotic manipulator is modeled to be a LPV system with a convex polytopic structure with the use of the LPV convex decomposition technique in a filter introduced. State feedback controllers, which satisfy the H, performance and the closed-loop pole-placement requirements, for each vertex of the convex polyhedron parameter space, are designed with the use of the linear matrix inequality (LMI) approach. Based on these designed feedback controllers for each vertex, a LPV controller with a smaller on-line computation load and a convex polytopic structure is synthesized. Simulation and experiment results verify that the robotic manipulator with the LPV controller always has a good dynamic performance along with the variations of the joint positions. © 2002 Wiley Periodicals, Inc. [source] LMI Approach to Guaranteed Cost Control for Networked Control SystemsASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 3-4 2005Shanbin Li This paper addresses the time-varying but bounded delay issue of networked control systems (NCS) within the framework of a discrete-time linear state-delayed system with norm-bounded uncertainty. A delay-dependent sufficient condition for the existence of a guaranteed cost controller for NCS is presented by a new Lyapunov-Krasovskii functional. The condition is formulated as a set linear matrix inequalities (LMIs). The resulting controller can not only asymptotically stabilize the system but also guarantee an adequate level of performance. Theoretical analysis and simulation results show that the control strategy presented in this paper is effective and feasible. [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] A robust fault detection and isolation filter design under sensitivity constraint: An LMI approachINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 15 2008Saverio Armeni Abstract This paper deals with the design of a residual generator (RG) for linear time-invariant systems subject to simultaneous different faults, disturbances and measurement noises. The objective is to design an RG filter that maximizes the transmission from a potential fault to a related residual, while minimizing the ones from nuisances (disturbances, measurement noises and other faults). The isolation of each fault is carried out by designing a bank of RG filters, each one insensitive, as much as possible, to nuisances and capable of detecting the occurrence of its related fault. The design is carried out through ,, filtering techniques under an eigenstructure assignment constraint. Under mild assumptions, the RG filter can be obtained by solving a ,-parameterized linear matrix inequality optimization problem. A comparison with existing fault detection and isolation (FDI) methods is considered in order to exhibit the relative merits of the proposed method. Copyright © 2008 John Wiley & Sons, Ltd. [source] Delay-dependent fault estimation for uncertain time-delay nonlinear systems: an LMI approachINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 18 2006Sing Kiong Nguang Abstract This paper deals with the problem of robust fault estimation for uncertain time-delay Takagi,Sugeno (TS) fuzzy models. The aim of this study is to design a delay-dependent fault estimator ensuring a prescribed ,, performance level for the fault estimation error, irrespective of the uncertainties and the time delays. Sufficient conditions for the existence of a robust fault estimator are given in terms of linear matrix inequalities (LMIs). Membership functions' (MFs) characteristics are incorporated into the fault estimator design to reduce the conservativeness of neglecting these characteristics. Finally, a numerical example is given to illustrate the effectiveness of the proposed design techniques. Copyright © 2006 John Wiley & Sons, Ltd. [source] Stability analysis and guaranteed domain of attraction for a class of hybrid systems: an LMI approachINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 5 2003S. Palomino Bean Abstract This paper presents sufficient conditions for the regional stability problem for switched piecewise affine systems, a special class of Hybrid Systems. This class of systems are described by an affine differential equation of the type x,=A(,)x+b(,), where x denotes the continuous state vector and , is a vector of logical variables that modifies the local model of the system in accordance with the continuous dynamics. Using a Lyapunov function of the type v(x)=x,P(x)x, we present LMI conditions that, when feasible, guarantee local stability of the origin of the switched system. Examples of switched affine systems are used to illustrate the results. Copyright © 2003 John Wiley & Sons, Ltd. [source] A new method for mixed H2/H, control with regional pole constraintsOPTIMAL CONTROL APPLICATIONS AND METHODS, Issue 3 2003Jenq-Lang Wu Abstract In this paper, the problem of state feedback mixed H2/H, control with regional pole constraints is studied. The constraint region is represented by several algebraic inequalities. This constrained optimization problem cannot be solved via the LMI approach. Based on the barrier method, we instead solve an auxiliary minimization problem to get an approximate solution. We shall show that the obtained minimal solution of the auxiliary minimization problem can be arbitrarily close to the infimal solution of the original problem. An example is provided to illustrate the benefits of the approach. Copyright © 2003 John Wiley & Sons, Ltd. [source] An LMI approach to design observer for unknown inputs Takagi-Sugeno fuzzy modelsASIAN JOURNAL OF CONTROL, Issue 4 2010M. Chadli Abstract This paper considers the design of an observer for a Takagi-Sugeno (T-S) fuzzy model subject to unknown inputs affecting states and outputs of the system simultaneously. Uncertainties affecting state matrices are also considered. Based on the Lyapunov method, sufficient conditions in Linear Matrix Inequalities (LMI) terms are proposed to design the given unknown input T-S observer. In order to improve the performances of the proposed T-S observer, the pole placement in an LMI region is also considered. An numerical example is given to illustrate the validity of the derived results. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source] | ||||||||||