对带有线性动力学性能和非线性动力学性能及带有系统内部不确定因素和外界扰动因素的单输入单输出系统,本文给出了终端滑模跟踪控制方法。由于该系统状态难以测量,本文将系统内部未知的复杂非线性动力学因素及系统外界扰动因素统称为"总扰动",并视其为系统模型的增广状态。该增广状态及系统状态可以通过一个线性扩展状态观测器同步评估出来。本方法的特点是设计这样一个观测器以保证近似误差一致最终有界于一个半径为设计参数的函数的球内,该球半径可以通过优化设计参数达到任意小的程度。基于所设计的线性扩展状态观测器的输出,文中给出了保证系统输出密切跟踪所需信号的终端滑模控制器,数值模拟的结果表明所给出的控制器是有效的。
In this paper,the terminal sliding mode tracking control is proposed for the single-input and single-output systems with known linear dynamics,unknown nonlinear dynamics as well as internal model uncertainties and external disturbance. And the system states are unavailable for measurement. The terms including unknown complicated nonlinear dynamics,internal and external disturbances are defined as total disturbance,and it is considered as an augmented state of model plant. Then this augmented state and the system states can be estimated simultaneously through a linear extended state observer. This method is to design an observer which can guarantee the approximation error to be uniformly ultimately bounded with respect to a ball whose radius is a function of design parameters. So this ball radius can be arbitrarily as small as desired by tuning design parameters. Based on the outputs of the designed linear extended state observer,the terminal sliding mode controller has been proposed,which can guarantee the system output to closely track the desired signal. Numerical simulation results are given to illustrate the effectiveness of the proposed controller.