数控机床优化精度控制系统中,XY平台伺服系统存在扰动、系统参数不确定性、机械延迟以及两轴驱动系统参数不匹配等原因,影响了平台的定位精度。为此对轮廓误差分配模型的交叉耦合控制方法进行了改进,对于设定值前向补偿的交叉耦合控制,估算出两轴间的轮廓误差,直接反馈予各轴的设定值输入,进行补偿。上述方法具有预先修正偏差的能力,及时修正了偏差,加快了误差修正速度,有效提高了系统的控制精度。仿真结果表明,所提出的两轴运动平台直线电机控制方法有效地减小了平台的轮廓误差和位置误差,提高了平台的定位精度。
For the existing problems that influence the precision of positioning in direct drive XY table servo system such as disturbances, uncertainty of the system parameters, electric-machine delay and parameters unmatched of the double-axes drive system, the cross-coupled controller based on the contour error distribution model was improved in this paper. The novel cross-coupled controller based on setting forward compensation was used to estimate the contour error between two axes. It directly feeds the contour error back to the set point of each axis to modify the deviation in advance and accelerate the speed of error correction, thus effectively improve the control precision of the system. The simulation results show that the contour error as well as position errors is effectively reduced, and the positioning accuracy is greatly improved by using the proposed method.