带有迟滞非线性的气动运动模拟平台自抗扰轨迹跟踪控制

Active Disturbance Rejection Trajectory Tracking Control for Pneumatic Motion Simulation Platform with Hysteresis Nonlinearity

针对带有迟滞非线性的气动运动模拟平台的轨迹跟踪提出了带有切换扩张状态观测器的自抗扰控制方法。气动运动模拟平台的迟滞非线性特性主要指气动人工肌肉在正向充气反向放气时长度和拉力曲线的差异。针对此特性设计了切换扩张状态观测器来估计和补偿模型非线性,分别对于气动人工肌肉正反向充放气的不同模型采用不同的观测器增益,以提高状态估计效果,减小跟踪误差。进一步,设计了状态误差反馈控制器,得到了基于切换扩张状态观测器的二阶非线性动态系统全局有界稳定的充分条件。最后实验结果证实了所设计的切换扩张状态观测器的实际效果。

An active disturbance rejection control method with switched extend state observers is proposed for the pneumatic motion simulation platform with hysteresis nonlinearity to track trajectory.The hysteresis nonlinearity of the pneumatic motion simulation platform mainly refers to the difference between the length and tension curves of the pneumatic artificial muscle during positive inflation and negative deflation.According to this characteristic,a switched extend state observer is designed to estimate and compensate the nonlinearity of the model.Different observer gains are adopted for different models of the pneumatic artificial muscle during positive inflation and negative deflation,so as to improve the effect of estimation and reduce tracking errors.Furthermore,the state error feedback controller is designed,and the sufficient conditions for the global bounded stability of the second-order nonlinear dynamic system based on the switched extend state observer are obtained.Finally,the experimental results confirm the practical effect of the switched extended state observer.