基于加减速控制的自适应加速度反向间隙补偿

Backlash Compensation of Adaptive Acceleration Based on Acceleration and Deceleration Control

针对数控机床滚珠丝杆进给系统中反向间隙的存在严重影响数控机床定位精度的问题,提出基于加减速控制的自适应加速度反向间隙补偿方法。基于该方法建立反向间隙传动模型,计算补偿过程的加速时间,在加速时间不等于伺服周期整数倍时,反推补偿过程中的加速度值,从而准确补偿反向间隙,避免出现过补偿或欠补偿现象。通过仿真验证该补偿方法的有效性,数控平台实验结果是该补偿方法可将X轴目标点正、负向平均偏差减小在-2μm^3μm之间波动,表明所提出的方法可以有效降低因反向间隙造成的定位误差,提高了数控机床的定位精度。

In view of the serious impact of the backlash inside ball screw feeding system of CNC machine tool has on its positioning accuracy, a backlash compensation method of adaptive acceleration based on ac-celeration and deceleration control is proposed to solve this problem. On the basis of the proposed method, a backlash transmission model is established to calculate the acceleration time for the compensation process. When the acceleration time is not an integral multiple of servo period, the acceleration value is reversely de-rived for accurate backlash compensation to avoid over compensation or under compensation. Simulations are conducted to verify the effectiveness of the compensation method. Furthermore, results of the CNC plat-form experiment show that this compensation method can reduce the deviations of positive and negative aver-age of X - axis, which fluctuates in the range of - 2 ？3pm. The results reveal that the proposed methodcan decrease positioning errors which caused by backlash effectually, and then it can improve the positioning accuracy of CNC machine tool.