Stability analysis and stabilization for discrete-time singular delay systems

Stability analysis and stabilization for discrete-time singular delay systems are addressed,respectively.Firstly,a sufficient condition for regularity,causality and stability for discrete-time singular delay systems is derived.Then,by applying the skill of matrix theory,the state feedback controller is designed to guarantee the closed-loop discrete-time singular delay systems to be regular,casual and stable.Finally,numerical examples are given to demonstrate the effectiveness of the proposed method.

Design of a bilinear fault detection observer for singular bilinear systems

A bilinear fault detection observer is proposed for a class of continuous time singular bilinear systems subject to unknown input disturbance and fault. By singular value decomposition on the original system, a bilinear fault detection observer is proposed for the decomposed system via an algebraic Riccati equation, and the domain of attraction of the state estimation error is estimated. A design procedure is presented to determine the fault detection threshold. A model of flexible joint robot is used to demonstrate the effectiveness of the proposed method.

Design of switched controllers for discrete singular bilinear systems

In this paper, switched controllers are designed for a class of nonlinear discrete singular systems and a class of discrete singular bilinear systems. An invariant principle is presented for such switched nonlinear singular systems. The invariant principle and the switched controllers are used to globally stabilize a class of singular bilinear systems that are not open-loop stable.

Implementation of Legendre Neural Network to Solve Time-Varying Singular Bilinear Systems

Bilinear singular systems can be used in the investigation of different types of engineering systems.In the past decade,considerable attention has been paid to analyzing and synthesizing singular bilinear systems.Their importance lies in their real world application such as economic,ecological,and socioeconomic processes.They are also applied in several biological processes,such as population dynamics of biological species,water balance,temperature regulation in the human body,carbon dioxide control in lungs,blood pressure,immune system,cardiac regulation,etc.Bilinear singular systems naturally represent different physical processes such as the fundamental law of mass action,the DC motor,the induction motor drives,the mechanical brake systems,aerial combat between two aircraft,the missile intercept problem,modeling and control of small furnaces and hydraulic rotary multimotor systems.The current research work discusses the Legendre Neural Network’s implementation to evaluate time-varying singular bilinear systems for finding the exact solution.The results were obtained from two methods namely the RK-Butcher algorithm and the Runge Kutta Arithmetic Mean(RKAM)method.Compared with the results attained from Legendre Neural Network Method for time-varying singular bilinear systems,the output proved to be accurate.As such,this research article established that the proposed Legendre Neural Network could be easily implemented in MATLAB.One can obtain the solution for any length of time from this method in time-varying singular bilinear systems.

Design of bilinear observer for singular bilinear systems

A bilinear observer is proposed for a class of singular bilinear system subject to unknown input disturbance. Based on singular value decomposition technique, the existence of the solution to the decomposed system is presented. Then a bilinear observer is proposed for the decomposed system based on an algebraic Riccati equation, and the domain of attraction of the state estimation error is derived. Finally, a detailed design procedure is given to design a bilinear observer for a model of flexible joint robot, which demonstrates the effectiveness of the proposed method.

Observer-based H_∞ Filtering of 2-D Singular System Described by Roesser Models

This paper discusses the problem of the H∞ filtering for discrete time 2-D singular Roesser models (2-D SRM). The purpose is to design an observer-based 2-D singular filter such that the error system is acceptable, jump modes free and stable, and satisfies a pre-specified H∞ performance level. By general Riccati inequality and bilinear matrix inequalities (BMI), a sufficient condition for the solvability of the observer-based H∞ filtering problem for 2-D SRM is given. A numerical example is provided to demonstrate the applicability of the proposed approach.

A New Admissibility Condition of Discrete-time Singular Systems with Time-varying Delays

This paper gives a novel delay-dependent admissibility condition of discrete-time singular systems with time-varying delays. For convenience, the time-varying delay is assumed to be the sum of delay lower bound and the integral multiples of a constant delay. Specially, if the constant delay is of unit length, the delay is an interval-like time-varying delay. The proposed admissibility condition is presented and expressed in terms of linear matrix inequality (LMI) by Lyapunov approach. Generally, the uncertainty of time-varying delay would lead to conservatism. In this paper, this critical issue is tackled by accurately estimating the time-varying delay. Consequently, the proposed admissibility condition is less conservative than the existing results, which is demonstrated 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.

Positive-Controllability,Positive-Near-Controllability,and Canonical Forms of Driftless Discrete-Time Bilinear Systems

Controllable canonical forms play important roles in the analysis and design of control systems.In this paper,a fundamental class of discrete-time bilinear systems are considered.Such systems are of interest since,on one hand,they have the most complete controllability theory.On the other hand,they can be nearly-controllable even if controllability fails.Firstly,controllability of the systems with positive control inputs is studied and necessary and sufficient algebraic criteria for positive-controllability and positive-near-controllability are derived.Then,controllable canonical forms and nearly-controllable canonical forms of the systems are presented,respectively,where the corresponding transformation matrices are also explicitly constructed.Examples are given to demonstrate the effectiveness of the derived controllability criteria and controllable canonical forms.

ON NEARLY-CONTROLLABLE SUBSPACES OF A CLASS OF DISCRETE-TIME BILINEAR SYSTEMS

If a linear time-invariant system is uncontrollable,then the state space can be decomposed as a direct sum of a controllable subspace and an uncontrollable subspace.In this paper,for a class of discrete-time bilinear systems which are uncontrollable but can be nearly controllable,by studying the nearly-controllable subspaces and defining the near-controllability index,the controllability properties of the systems are fully characterized.Examples are provided to illustrate the conceptions and results of the paper.

不确定广义双线性系统的鲁棒镇定

针对带有不确定参数的广义双线性系统的鲁棒镇定问题进行研究,其中不确定参数是时变且范数有界的.本文的目的是设计状态反馈控制器,使得对所有满足条件的不确定参数闭环系统都是渐近稳定的.通过引入广义二次稳定的概念、采用Lyapunov方法,分别给出了不确定广义双线性系统在两种不同情形下可镇定的充分条件;此外,两个数值例子分别说明了两种设计方法的有效性和合理性.

广义双线性系统的变结构控制

利用广义Lyapunov函数方法研究广义双线性系统的变结构控制问题。首先,考虑确定的广义双线性系统,通过引进滑动模动态补偿器来选取切换面,进而设计变结构控制器以保证闭环系统的渐近稳定性。其次,用类似的方法给出了不确定广义双线性系统的变结构控制设计,有效地解决了不确定广义双线性系统的变结构控制问题。最后,通过数值算例说明了设计方法的合理性和有效性。

双线性广义系统稳定性控制分析

利用所构造的两种广义Lyapunov函数,在广义系统容许的条件下,分别设计了双线性广义系统的稳定控制,且上面存在的2种控制具有不同的表现形式.同时,考查了控制受上下界约束时,选择适当的控制,使闭环系统全局一致渐近稳定.对单输入的双线性广义系统,探讨出闭环系统在原点附近的一个稳定域.最后,给出了一个实例说明所得到结论的正确性.

不确定时滞广义双线性系统的鲁棒镇定

针对不确定参数是时变但满足匹配条件的时滞广义双线性系统的鲁棒控制问题进行了研究,设计状态反馈鲁棒控制器,使得所有满足条件的不确定时滞广义双线性系统鲁棒稳定。基于Lyapunov稳定性理论,采用线性矩阵不等式方法,提出了不确定时滞广义双线性系统鲁棒镇定的充分条件,并给出了使得闭环系统鲁棒镇定的状态反馈控制器设计方法。定理解决了介于非线性和线性之间的不确定时滞广义双线性系统的有关理论。仿真实例说明了定理的有效性和合理性。

离散广义双线性系统的稳定控制分析

讨论了离散广义双线性系统稳定控制问题。研究了离散广义双线性系统稳定控制存在的条件,并给出了相应的控制方案。所采用的方法是利用广义系统分解,运用Lyapunov方法证明线性状态控制可以使闭环系统在原点附近渐近稳定。同时研究了不分解系统,通过构造广义李雅普诺夫函数的方法,给出了使闭环系统稳定的条件。对于离散广义双线性系统有关理论的证明,可以看作是正常离散双线性系统的拓广。

基于输出反馈的广义双线性时滞系统H_∞容错控制

讨论了基于广义双线性系统H∞容错控制的概念,给出广义双线性时滞系统H∞容错控制的输出反馈控制器的存在条件和设计方法.所设计的反馈控制器在正常情况下或有执行器发生故障时,都能使闭环系统渐进稳定,且闭环输入输出信号满足H∞性能指标.

基于输出反馈的广义双线性系统H_∞容错控制

基于非线性系统H∞容错控制的概念,给出了实现广义双线性系统H∞容错控制的输出反馈控制器的存在条件和设计方法,保证设计的反馈控制器在正常情况下和存在执行器故障的情况下,都能使闭环系统渐近稳定,且闭环输入输出信号满足H∞性能指标。最后的仿真结果证明了结论的正确性。

一类双线性生态系统的无源控制

研究了一类广义双线性系统的无源控制问题,利用广义Lyapunov 函数和线性矩阵不等式,给出了广义双线性系统无源且零解渐近稳定的充分条件,并在一定条件下得到存在状态反馈控制器,使得闭环系统无源且零解渐近稳定的充分条件,同时给出相应的控制器构造方法.

离散广义双线性系统的稳定控制

针对离散广义双线性系统,研究了稳定控制存在的条件,给出了相应的控制方案。所采用的方法是利用广义系统分解,选择适当的控制,运用Lyapunov方法证明线性状态控制可以使闭环系统在原点附近渐近稳定。对于这一类离散广义双线性系统有关理论的证明,可以看作是正常离散广义双线性系统的拓广。给出了一个可行性的应用算例,同时仿真结果也说明了该方法的有效性。所得稳定性的判据对于选择合适的控制方案具有实际指导意义。

线性奇异摄动系统的矩阵不等式方法H_∞控制

本文将双线性矩阵不等式(BLMI)方法应用于奇异摄动系统的H∞控制,结合奇异系统的有界实引理,将含有小参数的Riccati不等式转化为与小参数无关的等价的两个不等式问题,得到奇异摄动系统H∞控制的充要条件。由于不需要对奇异摄动系统进行快慢分解,本文提出的方法对非标准奇异摄动系统均适用。在此证明了矩阵不等式与摄动参数无关,有效地避免了奇异摄动系统的病态数值问题。仿真结果验证了该方法是简单和有效的。