针对存在参数摄动和外部扰动力矩的PMSM伺服系统位置跟踪控制问题,提出一种基于扰动观测和补偿的滑模控制方法。采用扰动观测器估计系统参数摄动以及负载力矩,并在此基础上对等效扰动进行补偿,减小了模型不确定性对系统控制性能影响,系统的位置跟踪误差由O.85rad减小到O.35rad;在保证系统稳定性的前提下,去除了常规滑模控制中的不连续控制项,有效地减小了抖振。实验结果表明,与工程上常用的PID算法相比,基于扰动观测和补偿的滑模控制算法不仅能够显著提高PMSM伺服系统的位置跟踪精度,而且能有效地削弱抖振。
A disturbance observation and compensation based sliding mode control scheme was proposed for the position tracking control of PMSM servo system with parameters perturbation and external disturb- ance torque. A disturbance observer was investigated to estimate the parameter perturbation and the dis- turbance torque, and the equivalent external disturbance torque was compensated according to the output of the disturbance observer, then the influence of the model uncertainty to the system control performance was reduced,and the position tracking error of the system was reduced from 0.85 rad to 0.35 rad. The discontinuous control term in traditional sliding mode control was chopped off while the stability of the closed system was guaranteed, the chattering phenomena was remedied effectively. Experimental results show that, compared with the traditional PID control scheme commonly used in practical engineering, the disturbance observation and compensation based sliding mode control scheme not only has higher tracking accuracy, hut also eliminates the chattering phenomena effectively.