基于被动柔顺装置的改进PID控制方法

Improved PID control method based on passive compliance device

为了解决机器人铣削过程中存在力波动的问题,设计了一种被动柔顺装置并提出了一种基于被动柔顺装置的改进PID控制方法。柔顺装置安装于机器人末端,通过仿形轮、导轨和滑块的相对运动来达到沿着表面铣削的效果。改进的PID控制方法在参考信号之后引入二阶设定点滤波器,并设置合理的参数,首先在MATLAB/Simulink环境搭建模型,然后通过对比仿真实验证明该方法可以减少超调量的同时提高响应速度,并减少系统误差。随后,在Adams软件导入模型进行仿真实验,初步证明了该方法可以减少接触力的波动。同时,铣削实验进一步证明了该方法可以在铣削不同位置的表面的情况下均可减少仿形轮压力Fz的波动,压力极差减少0.5 N~0.6 N,方差减少15%~20%,并且铣削后的工件表面质量较好,证明了提出的方法的可行性。

In order to address the issue of force fluctuation in robotic milling processes,a passive compliance device is designed,and an improved PID control method based on the passive compliance device is proposed.The compliance device is installed at the end effector of the robot and achieves milling along the surface through the relative motion of a contour wheel,guide rail,and slider.The improved PID control method introduces a second-order set point filter after the reference signal,sets reasonable parameters,builds a model in MATLAB/Simulink environment,and then proves through comparative simulation experiments that this method can reduce the overshoot,improve the response speed,and reduce the system error.Then,simulation experiments are carried out in Adams,and it is preliminarily proved that this method can reduce the fluctuation of contact force.At the same time,the milling experiment proves that the method can reduce the fluctuation of the pressure F z of the contour wheel under the condition of milling the surface at different positions,the pressure range is reduced by 0.5~0.6N,the variance is reduced by 15%~20%,and the surface quality of the workpiece after milling is better,which proves the feasibility of the proposed method.