Fuzzy controller design for switched fuzzy systems via output feedback technique

For quasi-linear parameter varying (quasi-LPV) systems with bounded disturbance, a synthesis approach of dynamic output feedback robust model predictive control (OFRMPC) with the consideration of input saturation is investigated. The saturated dynamic output feedback controller is represented by a convex hull involving the actual dynamic output controller and an introduced auxiliary controller. By taking both the actual output feedback controller and the auxiliary controller with a parameter-dependent form, the main optimization problem can be formulated as convex optimization. The consideration of input saturation in the main optimization problem reduces the conservatism of dynamic output feedback controller design. The estimation error set and bounded disturbance are represented by zonotopes and refreshed by zonotopic set-membership estimation. Compared with the previous results, the proposed algorithm can not only guarantee the recursive feasibility of the optimization problem, but also improve the control performance at the cost of higher computational burden. A nonlinear continuous stirred tank reactor (CSTR) example is given to illustrate the effectiveness of the approach.

This paper is devoted to the problems of non-fragile H∞ and L2–L∞ control for a class of linear systems with time-varying state delay. The purpose is to design a dynamic output feedback controller with additive gain variations such that the closed-loop system is asymptotically stable while satisfying a prescribed H∞ (or L2–L∞) performance level. By using linear matrix inequality approach, a delay-dependent stability criterion is obtained by introducing a new type of Lyapunov–Krasovskii functional. Based on the obtained criterion, sufficient conditions for the existence of desired controllers are derived, and the corresponding stabilisation dynamic output feedback controller design algorithm is proposed. Numerical examples are included to illustrate the benefit and effectiveness of the proposed method.

This paper is concerned with analyzing a novel model transformation of discrete-time Takagi-Sugeno (T-S) fuzzy systems with time-varying delays and applying it to dynamic output feedback (DOF) controller design. A new auxiliary model is proposed by employing a new approximation for time-varying delay state, and then delay partitioning method is used to analyze the scaled small gain of this auxiliary model. A sufficient condition on discrete-time T-S fuzzy systems with time-varying delays, which guarantees the corresponding closed-loop system to be asymptotically stable and has an induced l 2 disturbance attenuation performance, is derived by employing the scaled small gain theorem. Then the solvability condition for the induced l 2 DOF control is also established, by which the DOF controller can be found by solving a set of linear matrix inequalities (LMIs).

In this paper, the event-triggered dynamic output feedback controller design problem is addressed for a class of discrete-time nonlinear systems in network environment. An augmented closed-loop system is constructed and the sufficient conditions to ensure the mean-square asymptotically stability of the closed-loop system with a Hankel-norm performance by considering the event-triggered condition and using the reciprocally convex technique. It is shown that the solution of the fuzzyrule-dependent dynamic output feedback controller parameters can be obtained by variable substitution method. An example is provided to demonstrate the effectiveness of the proposed design method.

Dynamic output feedback controller design for affine T–S fuzzy systems with quantized measurements

In this paper, the $\boldsymbol{L}_{\infty}$ control synthesis problem for linear systems subject to actuator saturation and persistent bounded disturbance is studied. An $\boldsymbol{L}_{\infty}$ dynamic output feedback controller, an anti-windup compensator and an event generator are simultaneously designed. First, by using the quadratic Lyapunov function technique, a sufficient condition on the existence of the $\boldsymbol{L}_{\infty}$ dynamic output feedback controller, an anti-windup compensator and an event generator is established via linear matrix inequalities (LMIs). Such an integrated controller is able to guarantee the regional stabilization and the $\boldsymbol{L}_{\infty}$ performance of linear systems with actuator saturation and external persistent bounded disturbance. Second, novel algorithms are developed to optimize the upper bound on the $\boldsymbol{L}_{\infty}$ performance, the event-triggered threshold and the domain of attraction. Moreover, an output-based event-triggered mechanism applying to the anti-windup dynamic output feedback control design is provided, which reduces the number of control actuation updates and information transmission with respect to the traditional time-triggered control scheme.

This paper focuses on multiple delay-dependent noise-to-state stability (NSS) for a class of switched random nonlinear systems against uncertainty terms and intermittent sensor and actuator faults. External disturbances, nonlinear functions, as well as measurement noise, are also taken into account. This is the first attempt to achieve dynamic output feedback controller design for uncertain switched random nonlinear systems subject to intermittent sensor and actuator faults. First, a controller is established to perform passive fault-tolerant control (FTC). Random systems are more common than Ito stochastic systems. Thus, compared with the previous works, the proposed controller has a wider application scope and is more feasible. Next, an augmented closed-loop system is exhibited to realize NSS. Moreover, a piecewise Lyapunov function is utilized with less conservatism than common Lyapunov function. The delay dependent stability conditions are gathered via linear matrix inequalities (LMIs) and controller matrices are earned. At last, the novelty and validity of the approach suggested in this paper are demonstrated through two simulation examples.

This note investigates the problem of output feedback H∞ control for linear discrete-time systems. Three types of H∞ controllers are considered, namely, static output feedback controllers, dynamic output feedback controllers, and observer-based output feedback controllers. New design conditions for the three type of output feedback controllers are introduced in terms of unified linear matrix inequality (LMI) representations, which guarantee the prescribed H∞ performances of the closed-loop systems. In contrast to the existing LMI conditions for designing the output feedback H∞ controllers, the improvement of the proposed results over the existing ones is shown by theoretical proof and numerical example.

In this paper, a new stabilization condition of switched fuzzy systems is proposed. The dynamic output feedback control problem is addressed for a class of switched fuzzy Systems. The dynamic output feedback with sufficient conditions and the design method of controller is given using multiple Lyapunov function method and switching law. The closed-loop system asymptotically stable is given by the designed controller. Adopting the dynamic output feedback control law, the order of the closed-loop system is reduced, which is helpful to improve the reliability of the system. Finally, simulation results verify the effectiveness of the conclusion.

This paper considers the design problem of dynamic output feedback control for fractional-order (FO) Takagi-Sugeno fuzzy systems with uncertain parameters. Via the application of FO system stability theory, robust control method and the linear matrix inequality techniques, sufficient conditions are given for the stability analysis and the existence of the dynamic fuzzy output feedback controllers. The dynamic output feedback controller designed here guarantees the robust stability of the closed-loop system. Finally, a fractional order chaotic system simulation example is given to illustrate the effectiveness of the design approach here.

The problem of dynamic output feedback control stabilization is considered for a class of multi-time delays uncertain nonlinear systems. Based on LMI and proper Lyapunov functions, a sufficient condition for the existence of robust output feedback controller is proposed, which ensures that the closed-loop system is robust stable. The dynamic output feedback controller is designed by the feasible solution of the matrix inequality with constraint. At last, by using matrix orthogonal complement, the parameters solving methods of output feedback controller is also provided.

In this paper, we address a synthesis problem of the parameter-dependent output feedback H∞ control for linear parameter-varying systems with time-delay. The scheme adopts the parameter-dependent past state information to construct the dynamic output feedback controller. In this case, on basis of the quadratic Lyapunov functional with parameter-dependence, we analyze the parameter-dependent H∞ stability conditions for the closed-loop time-delayed linear parameter-varying system in terms of linear matrix inequalities. However, this stability condition is of an infinite-dimension. To derive computationally tractable criteria for the dynamic output feedback controller, several slack variables and a convex relaxation technique are employed to have the infinite-dimensional condition of linear matrix inequalities cast into a finite dimensional convex optimization problem. By solving the convex optimization problem, we harvest the dynamic output feedback controller with memory for the time-delayed linear parameter-varying system. Finally, two examples are included to illustrate the effectiveness of the proposed approach.

This work presents a convex parametrization of H ∞ output feedback controllers for positively dominated systems. The objective is to design static and dynamic output feedback controllers such that the closed-loop system is positively dominated, asymptotically stable and the H ∞ norm from the exogenous input to the regulated output is minimized. By utilizing Youla parametrization, the stabilizing controllers which give rise to a positively dominated system is parameterized by Q-parameters and extended to design static and dynamic H ∞ output feedback controllers through semi-definite programming (SDP). Due to the versatility of the presented framework for positively dominate systems, the design is extended to robust performance scenarios with structured and unstructured norm-bounded uncertainties.

Output feedback [formula omitted] finite-time control of switched positive delayed systems with MDADT

A passivity-based dynamic output feedback controller design is considered for a finite collection of non-square linear systems. Design of a single controller for a set of plants i.e. simultaneous stabilization is an important issue in the area of robust control design. We first determine a squaring gain matrix and an additional dynamics that is connected to the systems in a feedforward way, then a static passivating control law is designed. Consequently, the actual feedback controller will be the static control law combined with the feedforward dynamics. A necessary and sufficient condition for the existence of the parallel feedforward compensator is given by the static output feedback formulation. In contrast to the previous result [1], a technical condition for constructing the parallel feedforward compensator is removed by proposing a new type of the parallel compensator.