直接驱动XY平台位置域轮廓跟踪控制

Contour tracking control in position domain of direct drive XY table

针对直接驱动XY平台轮廓误差近似模型建立困难的问题,提出一种提高轮廓跟踪性能的位置域轮廓跟踪控制方法.通过将双轴运动系统等效为主-从运动方式,主动轴(X轴)以位置量作为自变量,将从动轴(Y轴)的运动描述为不同轮廓跟踪要求的X的函数.通过从时域到位置域的一一映射,得到双轴运动系统的位置域动态模型.提出了位置域PD控制策略,主动轴运动以自身为参考产生的位置跟踪误差为零,仅有从动轴的运动跟踪误差影响到了最后的轮廓误差.仿真结果表明,位置域轮廓控制相比时域轮廓控制能够获得更好的跟踪精度.

In order to solve the problem that the contour error approximation model for the direct drive XY table is hard to be established, a position domain contour tracking control method was proposed for improving the contour tracking performance. Through making a biaxial motion system equivalent to a drive-dirven motion mode, the position was used as an independent variable in the drive axis （X axis）, while the dirven motion （ Y axis） was expressed as the function of X according to different contour tracking requirements. Through the one to one mapping from time to position domains, a dynamic model for the position domain in the biaxial motion system was obtained. The position domain PD control strategy was proposed, the position tracking error for the drive axis motion is zero when X axis was used as the reference axis, and only the driven motion tracking error would affect the final contour error. The simulated results show that the position domain contour control has better tracking accuracy than the time domain contour control.