三轴运动平台改进型交叉耦合轮廓控制

Improved cross-coupled contour control for three axis motion table

为了削弱负载扰动及复杂轮廓误差模型对轮廓精度的影响,在单轴中采用比例控制作为位置环控制器,采用PDFF控制作为速度环控制器,以保证单轴跟踪精度.三轴间采用一种轮廓误差估算法来建立轮廓误差模型,运算更为简单.通过改进的交叉耦合控制结构进行轮廓控制器的设计,将轮廓误差的补偿量置于位置控制器前,能够实现跟踪误差与轮廓误差同时减小,以满足三轴运动平台的高精度加工要求.结果表明,改进后的三轴运动平台控制系统具有较高的轮廓精度和较强的抗扰性.

In order to weaken the influence of load disturbance and complicated contour error model on the contour accuracy, the proportional control was taken as the position loop controller and the PDFF control was taken as the speed loop controller in the single axis so as to ensure the tracking precision of single axis. A contour error estimation method was used to establish the contour error model among three axes, and thus the operation was simpler. The improved cross-coupled control （CCC） structure was adopted to design the contour controller, and the compensation amount of contour error was placed in the front of position controller. Therefore, the tracking error and contour error could be simultaneously decreased, and the highly precise machining requirements could be met for three axis motion table. The results show that the improved control system for three axis motion table has higher contour accuracy and stronger anti-disturbance ability.