Robust reliable guaranteed cost control for nonlinear singular stochastic systems with time delay

To study the design problem of robust reliable guaranteed cost controller for nonlinear singular stochastic systems, the Takagi-Sugeno （T-S） fuzzy model is used to represent a nonlinear singular stochastic system with norm-bounded parameter uncertainties and time delay. Based on the linear matrix inequality （LMI） techniques and stability theory of stochastic differential equations, a stochastic Lyapunov function method is adopted to design a state feedback fuzzy controller. The resulting closed-loop fuzzy system is robustly reliable stochastically stable, and the corresponding quadratic cost function is guaranteed to be no more than a certain upper bound for all admissible uncertainties, as well as different actuator fault cases. A sufficient condition of existence and design method of robust reliable guaranteed cost controller is presented. Finally, a numerical simulation is given to illustrate the effectiveness of the proposed method.

Robust H-infinity fuzzy control for uncertain Markovian jump nonlinear singular systems with wiener process

This paper deals with the problems of robust stochastic stabilization and H-infinity control for Markovian jump nonlinear singular systems with Wiener process via a fuzzy-control approach. The Takagi-Sugeno (T-S) fuzzy model is employed to represent a nonlinear singular system. The purpose of the robust stochastic stabilization problem is to design a state feedback fuzzy controller such that the closed-loop fuzzy system is robustly stochastically stable for all admissible uncertainties. In the robust H-infinity control problem, in addition to the stochastic stability requirement, a prescribed performance is required to be achieved. Linear matrix inequality (LMI) sufficient conditions are developed to solve these problems, respectively. The expressions of desired state feedback fuzzy controllers are given. Finally, a numerical simulation is given to illustrate the effectiveness of the proposed method.

随机奇异T-S模糊系统的有限时间鲁棒H_∞控制

讨论了一类具有伊藤类型随机奇异T-S模糊系统有限时间鲁棒H∞控制问题.首先,针对含有界干扰的随机奇异系统,采用T-S模糊模型进行系统描述,同时给出了随机奇异T-S模糊系统有限时间随机稳定和有限时间鲁棒H∞控制问题的定义;然后,根据有限时间稳定性理论,构造Lyapunov-Krasovskii函数,通过对状态反馈系统的分析,利用线性矩阵不等式方法给出该系统的有限时间鲁棒H∞控制器有解的充分条件;最后,数值算例说明了该设计方法的有效性.

Robust Control for Interval Type-2 T-S Fuzzy Discrete Systems with Input Delays and Cyber Attacks

This paper focuses on the robust control issue for interval type-2 Takagi-Sugeno(IT2 T-S)fuzzy discrete systems with input delays and cyber attacks.The lower and upper membership functions are first utilized to IT2 fuzzy discrete systems to capture parameter uncertainties.By considering the influences of input delays and stochastic cyber attacks,a newly fuzzy robust controller is established.Afterward,the asymptotic stability sufficient conditions in form of LMIs for the IT2 closed-loop systems are given via establishing a Lyapunov-Krasovskii functional.Afterward,a solving algorithm for obtaining the controller gains is given.Finally,the effectiveness of the developed IT2 fuzzy method is verified by a numerical example.

Robust Control for Discrete-Time T-S Fuzzy Singular Systems

This paper deals with the robust admissibility and state feedback stabilization problems for discrete-time T-S fuzzy singular systems with norm-bounded uncertainties.By introducing a new approximation technique,the initial membership functions are conveniently expressed in piecewiselinear functions with the consideration of the approximation errors.By utilizing the piecewise-linear membership functions,the fuzzy weighting-based Lyapunov function and the use of auxiliary matrices,the admissibility of the systems is determined by examining the conditions at some sample points.The conditions can be reduced into the normal parallel distributed compensation ones by choosing special values of some slack matrices.Furthermore,the authors design the robust state feedback controller to guarantee the closed-loop system to be admissible.Two examples are provided to illustrate the advantage and effectiveness of the proposed method.

Stabilization of a class of fuzzy stochastic jump systems with partial information on jump and sojourn parameters

This paper addresses the problem of the design of controller for fuzzy semi-Markov jump systems with hidden modes against the incomplete information on probability density functions of sojourn time. Two ubiquitous circumstances in practice are taken into account, which are often ignored in other related work:(1) the phenomenon that system modes cannot be accessed entirely is considered proactively;(2) finitely accessible information on probability density functions is studied in this paper. By virtue of hidden semi-Markov chain, the underlying systems are modeled as hidden semi-Markov jump systems, which are more general than semi-Markov jump systems. Sufficient conditions on the existence of desired accessible-mode-dependent fuzzy controller are derived such that the fuzzy hidden semi-Markov jump systems is mean square stable. Based on the emission probability matrix, the presented control policy overcomes the possible mode-mismatch between the system mode and the accessible mode.Finally, an example is provided to demonstrate the effectiveness of the proposed control method.

Multi-objective PID control for non-Gaussian stochastic distribution system based on two-step intelligent models

A new method for controlling the shape of the conditional output probability density function （PDF） for general nonlinear dynamic stochastic systems is proposed based on B-spline neural network （NN） model and T-S fuzzy model. Applying NN approximation to the measured PDFs, we transform the concerned problem into the tracking of given weights. Meanwhile, the complex multi-delay T-S fuzzy model with exogenous disturbances, parametric uncertainties and state constraints is used to represent the nonlinear weight dynamics. Moreover, instead of the non-convex design algorithms and PI control, the improved convex linear matrix inequality （LMI） algorithms and the generalized PID controller are proposed such that the multiple control objectives including stability, robustness, tracking performance and state constraint can be guaranteed simultaneously. Simulations are performed to demonstrate the efficiency of the proposed approach.

非齐次Markovian跳变模糊系统的H_(∞)控制

研究连续时间上的一类不确定非齐次Markovian跳变随机奇异区间二型模糊系统的随机稳定问题。假设状态项、输入项、扰动项和耗散项中出现的不确定矩阵是有界的。首先,根据Lyapunov稳定性定理并结合矩阵不等式原理研究带有Markovian跳变的区间二型模糊系统的性能指标;其次,运用矩阵不等式放缩方法给出系统随机容许的充分条件,并设计一种满足H∞性能指标的状态反馈控制器;最后,通过数值仿真验证了设计方法的可行性。