基于连续滑模控制的电液伺服系统轨迹追踪控制

Trajectory Tracking Control of Electro⁃hydraulic Servo System Based on Continuous Sliding Mode Control

为改善电液伺服系统的轨迹追踪精度,设计一种连续滑模控制器,用于对电液伺服系统进行轨迹追踪控制。在电液伺服系统的建模过程中,以控制阀阀芯位移为依据,得到了电磁线圈上的电压及电流方程。在液压流体的作用下,建立气缸内液压流体的流量方程。根据系统的轨迹误差,构造滑动面模型。在开环传递函数状态空间模型的基础上,建立控制律的连续方程,进而得出连续滑模控制器,以克服电液伺服系统的不确定性和扰动性,控制其对标定轨迹进行精确追踪。与干扰观测器对标定轨迹的追踪结果相比,该方法在追踪弧形及方波标定轨迹时,追踪精度分别提高了31.23%和39.98%。该方法能有效改善电液伺服系统的轨迹追踪精度。

In order to improve the trajectory tracking accuracy of electro⁃hydraulic servo system,a continuous sliding mode con⁃troller was designed for trajectory tracking control of electro⁃hydraulic servo system.In the modeling process of the electro⁃hydraulic ser⁃vo system,the voltage and current equations of the solenoid coil were obtained based on the displacement of the control valve core.Un⁃der the action of the hydraulic fluid,the flow equation of the hydraulic fluid in the cylinder was established.According to the trajectory error of the system,the sliding surface model was constructed.Based on the open⁃loop transfer function state space model,the continu⁃ous equation of the control law was established,and then the continuous sliding mode controller was obtained to overcome the uncertain⁃ty and disturbance of the electro⁃hydraulic servo system,so that the calibration trajectory could be accurately tracked.Compared with the tracking results of the disturbance observer,when using this method to tracking arc and square wave calibration trajectory,the tracking accuracy is improved by 31.23%and 39.98%respectively.This method can effectively improve the trajectory tracking accuracy of the electro⁃hydraulic servo system.