基于速度反馈的直流电动机复合控制方法

Composite control method of DC motor based on speed feedback

针对传统的直流电动机控制系统存在响应速度慢、抗干扰能力差的问题,提出了一种基于干扰观测器和速度观测器的直流电动机复合双环控制方法。该方法在直流电动机PID控制中加入前馈控制、干扰观测器和速度观测器。前馈控制用于提高系统的响应速度和跟踪特性;干扰观测器将外部力矩干扰及电动机模型参数变化造成的实际对象与名义模型的输出差异,等效到控制输入端,即观测出等效干扰,在控制中引入等效补偿,实现对干扰的完全抑制;速度观测器是将系统的转矩指令和实际速度作为输入,利用观测和滤波功能,得到一个不包含高频成分且不滞后于实际电动机速度的观测速度来代替实际速度,作为速度反馈信号。仿真结果表明,该方法具有很好的鲁棒性,降低了因测量噪声带来的电动机振动现象及速度和位置跟踪误差。

In view of problems of slow response speed and bad anti-disturbance ability existed in traditional control system of DC motor, the paper proposed a composite double-loop control method of DC motor based on disturbance observer and speed observer. The method adds feed-forward control, disturbance observer and speed observer in PID control of DC motor. The feed-forward control is used to improve response speed and tracking performance of the system. The disturbance observer makes external torque disturbance and output difference between practical object and nominal model caused by parameters change of motor model to be equivalent to control input end, namely observes equivalent disturbance and equivalent compensation is introduced in control, so as to realize complete inhibition for disturbance. The speed observer takes torque command and practical speed of the system as inputs, deploys observing and filtering functions to get observing speed without high-frequency components and lagging behind practical speed of the motor to replace the practical speed, the observing speed is used as feedback signal of speed. Simulation result shows that the method has good robust and reduces vibration phenomena and tracking error of speed and position of the motor caused by measuring noises.