直线伺服系统时滞参数辨识与补偿研究

Research on Identification and Compensation of Linear Servo System Time Delay Parameter

为解决直线伺服固有时滞特性对轨迹跟踪性能的影响,以典型的前馈加反馈二自由度控制结构为基础,分析直线伺服时滞特性对其轨迹跟踪精度的影响。在此基础上设计了前馈环节上的时滞控制器,之后针对时滞控制器位于前馈通道时作为一个超前环节控制上无法实现的问题,将时滞参数分为两部分,分别调节理想轨迹指令按照整数倍伺服周期延时及前馈控制信号滤波延时以达到时滞补偿的目的,引入牛顿迭代寻优进行最优时滞参数辨识。仿真与试验结果表明,在前馈加反馈二自由度控制的基础上加入时滞控制器可以有效减小直线伺服系统的闭环位置跟踪误差,特别是显著减小非零加加速度段的闭环位置跟踪误差,提高轨迹跟踪性能。

To eliminate the negative influence of intrinsic linear servo system time delay on the trajectory tracking performance, the reason behind the negative influence of linear servo system time delay on the tracking accuracy designed based on a typical two-degree-of-freedom controller structure with feedforward-feedback controller is theoretically analyzed. And then a time delay controller is designed to compensate the delay effect based on analysis. To conquer the non-realization of delay controller located in the feedforward path as a lead link the time delay is divided into two parts, one is a integrally multiple of servo cycle for adjusting the ideal trajectory command delay and located in the path of ideal trajectory command, another acts as a time parameter of feedforward control signal filter. And then the Newton iteration method is introduced to identify the optimal time delay control parameter. Simulation and experimental results show that the position tracking error of closed loop linear servo system can be reduced by adding the time-delay controller to the two degree of freedom controllers. Particularly the tracking error of nonzero jerk phases in trajectory is significantly reduced and finally the tracking performance is improved.