基于降阶扩张状态观测器的重复控制系统设计

A method of designing a reduced-order-extended-observer-based repetitive-control system

针对一类含有非匹配状态相关不确定性和外界干扰的伺服系统,提出一种基于降阶扩张状态观测器的重复控制方法,通过对不确定性和扰动进行实时估计和主动补偿,实现对周期性参考输入信号的高精度跟踪.首先,利用系统可测输出和控制输入信号设计降阶扩张状态观测器,对系统的不可测状态以及包含不确定性和外界干扰的总扰动进行估计;其次,通过选择合适的扰动补偿增益,构造基于扰动动态补偿的复合重复控制规律,消除总扰动对系统输出的影响,保证系统输出对周期性参考信号的准确跟踪;然后,基于小增益定理推导出系统稳定性条件和控制器参数设计算法;最后,通过数值仿真实例和实验验证所提方法的有效性和优越性.

This paper presents a reduced-order-extended-state-observer(RESO)based repetitive control(RC)method for a class of servo systems with mismatched state-dependent uncertainties and external disturbances.It aims to achieve high-accuracy tracking for periodic reference input by on-line estimating and compensating the effects of the state-dependent uncertatinties and disturbances.Firstly,using the measurable output and control input of the plant,an RESO is constructed to estimate the unmeasurable states and the total disturbance including uncertainties and external disturbances.Based on the estimates,a composite RC law is devised that dynamically compensates for the influence on the output of the total disturbance and ensure the precise tracking for the periodic reference signal.Then,based on the small gain theorem,both the stability criterion and design procedure of the closed-loop system are provided.Finally,simulational and experimental results demonstrate the effectiveness and superiority of the proposed method.