高精度工作台速度反向时摩擦补偿研究

The Research of Friction Compensation of High Precision Table at Velocity Reversal

在消除了丝杠导程、间隙等误差之后,进给系统中存在的摩擦是影响工作台运动控制精度的主要因素。由于摩擦的影响,导致工作台速度反向时产生爬行现象,从而使得误差突然增大。文章对摩擦误差产生机理和补偿方法进行了研究,从瞬态响应的视角揭示了摩擦误差产生的机理,通过数学推导精确计算出爬行现象的持续时间,以及由此导致的最大跟随误差。提出了一种零速对称式摩擦补偿方法,该方法在工作台的爬行时间内进行补偿,使工作台尽快脱离爬行状态,仿真结果表明该方法能够显著的减小爬行时间。

After eliminating the leadscrew lead and backlash, existing in the feeding system of friction is the main factor that affected the accuracy of motion control of table. Due to the influence of friction, the table gets crawl phenomenon when it＇ s at velocity reversal, so as to make the error increases suddenly. This article studies the mechanism of friction error and compensation methods, revealing the mechanism of friction error by the Angle of transient response and through mathematical derivation accurate calculate the duration of the crawling phenomenon, and the resulting in the largest follow error. A symmetric zero velocity friction compensation method is proposed, used at the crawling time of table to get table out of crawl state as soon as possible, and the simulation results show that this method can significantly reduce the crawl time.