FEEDBACK STABILIZATION OF NONHOLONOMIC CONTROL SYSTEMS WITH DRIFT

This paper presents a differential geometric approach for feedback stabilization of nonholonomic control systems with drift and its applicability is tested on two different systems possessing different algebraic structures: a system with six state variables and three controls, and a knife edge example. The approach is universal in the sense that it is independent of the vector fields determining the motion of the system, or of the choice of a Lyapunov function. The proposed feedback law is as a composition of a standard stabilizing feedback control for a Lie bracket extension of the original system and a periodic continuation of a specific solution to an open loop control problem stated for an abstract equation on a Lie group, an equation which describes the evolution of flows of both the original and extended systems. The open loop problem is solved as a trajectory interception problem in logarithmic coordinates of flows.     

控制受限的一类非完整动力学系统的镇定问题

考虑了控制受限的一类非完整动力学系统的镇定问题.在一定条件下经典非完整约束下的Lagrange方程可化为扩展的链式系统.利用滑动模态的思想和多步控制策略,设计了不连续反馈镇定律,该镇定律一方面满足控制受限条件,另一方面使得闭环系统的状态收敛到预先给定的原点的任意小的ε邻域中.最后对移动机器人进行了仿真,验证了该方法的有效性.     

一类非完整约束动力学系统的人工场导向控制

对于一类具有轮式移动机构的非完整动力学系统,本文通过建立人工场的方法来实 现其位姿镇定、轨迹跟踪和路径跟踪等控制问题.人工场用于导向和控制方向角,而通过辅助 的线速度控制以获取最佳收敛路径. 控制器设计中同时兼顾动力学扰动及实际系统速度和输 出力矩的饱和限制,所得控制器对于跟踪问题仅需知道期望位姿,而且结构简单、鲁棒性强、 便于实现.     

任意切换下不确定线性切换系统的鲁棒镇定

1引言 切换系统是一类重要的混合系统,它的稳定性是研究最为集中的问题之一.目前已引起国内学者的广泛关注[1,2].     

REDUCED‐ORDER MODELS FOR FEEDBACK STABILIZATION OF LINEAR SYSTEMS WITH A SINGULAR PERTURBATION MODEL

The problem of output feedback stabilization of linear systems based on a reduced‐order model is addressed in this paper. New reduced‐order models are proposed for the output feedback design of linear systems with a singular perturbation model. An output feedback controller with a zero steady‐state gain matrix is proposed for stabilizing this kind of system. It is shown that with the proposed controller the reduced‐order model based feedback design can guarantee the actual closed‐loop stability for the sufficiently small perturbation parameter. This approach can overcome the difficulties in the existing design method using the so‐called zeroth‐order approximation model, whose validity is highly dependent on the value of the perturbation parameter.     

非完整约束轮式移动机器人人工场导向控制研究

导向控制在非完整约束轮式移动机器人的运动控制中具有重要作用.该文通过建立人工场的方法来引导和控制方向角,通过辅助的线速度控制前进或后退,以获取最佳收敛路径.同时考虑到实际系统速度饱和限制,从而设计出一种新的非连续位姿镇定律.并将该结果扩展,使得平面内任意点-点镇定、轨迹跟踪和路径跟踪问题均可得以实现,且对于跟踪问题仅需知道期望位姿,所得控制器不仅设计简单、鲁棒性强、收敛速度快,还具有一定的普遍性.     

一类不确定非完整动力学系统的鲁棒镇定及其在移动机器人中的应用

本文讨论了一类带有未知惯性参数、动静态摩擦及外界干扰的非完整动力学系统的控制问题．基于变结构控制的思想，给出了该系统的镇定方法，使得Ｐｏｍｅｔ［３］关于非完整运动学系统的时变光滑镇定律可推广到相应的带有参数不确定和干扰的动力学系统上．最后，将所得结果应用于一类移动机器人的镇定控制，仿真结果验证了该方法的有效性．     

非线性仿射控制系统的高阶滑模控制

研究非线性仿射系统的高阶滑模控制问题.通过适当的输入及非线性状态变换将系统分解为一个关于切换变量及其高阶导数的低阶线性子系统和一个关于滑模的低阶非线性子系统,进而给出了其高阶滑模控制器的设计方法.最后,对两轮驱动的非完整移动机器人进行了数值仿真,结果表明高阶滑模控制在抖振减弱方面确实具有一定的作用.     

非线性交叉严格反馈系统的一种构造性设计方法

讨论非线性交叉严格反馈(cross strict feeback)系统的镇定问题,针对这类系统首次提出交叉回退(cross backsteping)设计方法,证明了整个控制系统的全局稳定性,并用仿真算例验证了方法的正确性.其结果大大拓宽了backstepping方法的适用范围.     

具有多滞后非线性定常关联控制系统的镇定性研究

建立了多组多滞后定常非线性控制系统的结构 概念,采用李雅普诺夫函数分解等价法,由 Riccati矩阵微分方程的对称正定解矩阵构造正 定二次型Ｖ函数,给出了无滞后无扰动参数线性定常控制孤立子系统的镇定性,蕴含具有滞 后控制向量函数的扰动结构参数的多组多滞后区间系数定常非线性关联控制系统的关联鲁棒 镇定的一个充分条件,同时给出了扰动参数与滞后非线性项界线的估计公式．     

一类非线性时变系统基于观测器的反馈稳定化

1　引言目前,有关非线性系统的状态反馈控制已取得了许多引人注目的研究结果,其中状态可测是此控制方法中的一个必不可少的假设.在实际中,许多系统的状态是部分可测或不完全可测,故构造观测器,并用估计状态实现反馈控制是一个非常有意义的研究工作.本文研究了一类仿射非线性时变系统基于状态观测器的输出反馈稳定控制问题.首先设计了系统的状态观测器,然后综合控制器和观测器得到了非线性输出反馈控制器,并证明了反馈后闭环系统的指数稳定性.研究结果表明,系统的控制器与观测器可以分离独立进行设计.2　系统的描述及预备知识考虑下列非线性…     

动态非完整控制系统的指数镇定及其在一类车式机器人中的应用

本文研究了用动力学方程表示的双输入链式非完整系统的镇定问题，设计出了非连续的指数镇定律，并将其用于一类移动机器人的位姿镇定中．仿真结果表明了该控制律的有效性．     

ITERATIVE LEARNING CONTROL IN FEEDBACK SYSTEMS BASED ON AN OBJECTIVE FUNCTION

An objective function is proposed and an iterative learning control algorithm is derived based on this. The objective function is a quadratic form consisting of the output error and the input. By adjusting the weights in the objective function, the control objective of good command following at smaller input energy can be realized. The weight on the input energy in the objective function is shown to be directly related to the forgetting factor for robust iterative learning control. The convergence of the control algorithm has been proven and its characteristics are shown in the simulation examples.     

GLOBAL ROBUST SERVOMECHANISM OF A CLASS OF NONLINEAR SYSTEMS USING OUTPUT FEEDBACK

The robust servomechanism problem (alternatively, output regulation problem) of the class of nonlinear systems in lower triangular form has been extensively studied in recent years. The semi‐global solution was first given by either state feedback or output feedback. The global solution by state feedback was given very recently. However, the global solution by output feedback has long been an open problem. In this paper, we present a set of solvability conditions of the global robust servomechanism problem for this class of nonlinear systems by output feedback.     

不确定相似组合系统的分散自适应输出反馈控制

本文讨论了不确定组合大系统的分散自适应输 出反馈控制问题,不确定项满足通常的匹配条件．针对不确定项界未知的情形,通过设计自 适应输出反馈控制器,使系统渐近稳定．仿真结果表明本文的设计方法是有效的．     

一类非线性组合大系统的分散输出反馈鲁棒镇定

研究了不确定非线性子系统经不确定非线性互联而成的组合大系统,给出了其可分散输出反馈鲁棒镇定的充分条件,说明了所得结论的广泛适用性以及相似结构与全息特性的密切相关性.     

一类非线性切换系统鲁棒H∞可靠控制

为了克服扰动与执行器故障对控制系统的影响，使系统具有抗干扰性和可靠性，针对一类不确定非线性切换系统，研究了在任意切换规则下鲁棒H∞可靠控制问题．首先，系统所有矩阵同时含有参数不确定性，并且系统也存在未知非线性扰动．当执行器存在故障时，基于线性矩阵不等式技术以及公共李亚普诺夫函数方法得到鲁棒H∞可靠控制器，使切换系统在任意切换律下全局二次稳定并且满足H∞性能指标．最后，通过求解凸优化问题得到了鲁棒H∞最优可靠控制器．仿真结果表明控制器在任意切换规则下是可行和有效的．     

STABILIZATION OF A CLASS OF NONLINEAR NON‐MINIMUM PHASE SYSTEMS

This paper tackles the problem of stabilization of a class of non‐minimum phase nonlinear systems which have zero dynamics with an eigenvalue zero of multiplicity 2. By adding some new terms, called cross terms, we are able to generalize the concept of the Lyapunov function with a homogeneous derivative along the trajectory, which was introduced in [4], to produce a suitable Lyapunov function. The Lyapunov function assures that the stability of an approximate system, which consists of some lower order terms of a nonlinear system with an eigenvalue zero of multiplicity 2, implies the stability of the whole system. Applying these to non‐minimum phase zero dynamics of nonlinear systems with such a center, a sufficient condition and a design method of state feedback control are obtained for stabilizing the systems.     

ADAPTIVE SLIDING MODE BACKSTEPPING CONTROL OF NONLINEAR SYSTEMS WITH UNMATCHED UNCERTAINTY

This paper considers an adaptive backstepping algorithm for designing the control for a class of nonlinear continuous uncertain processes with disturbances that can be converted to a parametric semi‐strict feedback form. Sliding mode control using a combined adaptive backstepping sliding mode control (SMC) algorithm, is also studied. The algorithm follows a systematic procedure for the design of adaptive control laws for the output tracking of nonlinear systems with matched and unmatched uncertainty.     

一类非最小相位非线性系统的神经网络自适应控制策略

针对一类非最小相位非线性系统，基于线性化和前馈补偿的思想，提出了神经自适应控制算法。得到了前馈控制律的闭环稳定性分析，并给出仿真结果。