Stability Analysis And Synthesis Of Several Types Of Switching Systems Under Input Saturation Constraints

Input saturation,that is actuator saturation,is a phenomena often encountered in practical engineering.It is due to the consideration of the physical properties,safety factors and technolog-ical constraints of the system in the operation process,which makes the magnitude of the signal that an actuator can deliver cannot be unlimited.Input saturation constraint is a kind of non-linear constraint that is very common in practical engineering.When studying the analysis and synthesis of control systems with input saturation constraints,if this constraint is not considered,the per-formance of the controlled system would be degraded,and even the stability of the closed-loop system would be lost.In addition,as a typical hybrid system,the switched system can effectively describe a variety of practical engineering systems,such as power systems,manipulator systems,flight control systems,etc.They are composed of limited subsystems and there is a switching logic to coordinate the switching between these subsystems.The comprehensive problem of switched system performance analysis and control is not a simple superposition between subsystems.There-fore,when studying the entire control problem of switched system,we must both design a good-performance controller and take into account the selection of control strategies.It is worth noting that there are still many open questions about the control problem of switched systems under input saturation constraints.The main work of this paper is as follows:1. The problem of switching neutral time-delay systems with actuator saturation is inves-tigated.The method of auxiliary time-delay feedback is introduced and used.A state feedback controller is designed to estimate the disturbance,and the closed-loop system is studied by select-ing an augmented Lyapunov-Krasovskii functional.The sufficient conditions for the asymptotic stability of closed-loop systems are obtained and expressed by linear matrix inequalities.Finally,a simulation example is presented to show the effectiveness of our proposed technique.2. The problem of anti-windup control for a class of continuous-time semi-Markov jump systems?S-MJSs?is studied.The admissible uncertainties in both the state and input matrices of the underlying system are considered.To eliminate the influences from input saturation,a class of anti-windup compensators are added into a pre-designed dynamic output feedback controller for stabilizing the S-MJSs without regard to saturation.First,the criterion of locally stochastic stabi-lization is established by deriving the infinitesimal generator for stochastic Lyapunov functional of the system under the compensated controllers,and the estimation of the domain of attraction of the closed-loop system is depicted.Next,sufficient design conditions for the anti-windup com-pensation gains are derived based on the lower and upper bounds of the transition rates.Finally,a numerical example is presented to show the effectiveness of the proposed theoretical results.3. The problem of disturbance attenuation and rejection for a class of switched nonlinear systems subject to input and sensor saturations is investigated,in which exosystem generated dis-turbances and₂-norm bounded disturbances are considered.The full-order and reduced-order observers are designed according to whether the system states are available or not.Based on the estimating values of the system states and exosystem generated disturbances,the design schemes for the composite controllers are put forward based on the full-order and reduced-order observers,respectively.For a switched system,the input and sensor saturations would influence the effec-tive synthesis of observer and controller.By sector nonlinearity technology,the stability of the augmented closed-loop systems under the proposed composite controllers are analyzed,and the conditions of synthesis of the observers and controllers are further presented to ensure the aug-mented systems to be robustly asymptotically stable with a weighted_?performance level.An example is given to guarantee the effectiveness of the proposed control schemes.