基于自抗扰控制的伺服系统输出间隙补偿研究

Compensation of Output Backlash in Servo Systems Based on Auto-Disturbance-Rejection Control

间隙非线性具有多值性和方向性,普遍存在于伺服系统中,可严重影响伺服系统的控制性能。为此,本文采用自抗扰控制器对伺服系统的输出间隙进行补偿,以抑制间隙非线性对系统性能的影响。自抗扰控制器由跟踪微分器、扩张状态观测器、非线性反馈控制律三部分组成,其中扩张状态观测器可对间隙引起的输出扰动进行估计,非线性反馈控制律则对估计出的扰动进行补偿。与相关研究相比,自抗扰控制器形式简单,易于工程实现,且具有较高的间隙补偿精度。仿真结果表明,上述方法是可行的。

Backlash is a non-smooth nonlinearity which can make the control performance of servo systems degraded severely by causing delays,oscillations, and inaccuracy. In order to eliminate the influences of the backlash characteristics, an Auto-Disturbance-Rejection Control （AD- RC） method is proposed for the servo systems. This method adopts an Extended State Observer （ESO） to estimate the disturbances resulted from the backlash of servo systems at first. Then, a feedback controller is adopted to compensate the disturbances derived from ESO. Compared with the previous studies, ADRC can improve the compensation accuracy a lot and can be implemented easily in engineering. Simulation results indicate that the method presented above is feasible.