滚珠丝杠传动机构的微动特性及轨迹跟踪控制

滚珠丝杠传动的机床进给机构在微观运动条件下的各种非线性因素和进给系统较高的机械增益是影响机床运动的控制精度进一步提高的主要因素.本文研究了滚珠丝杠进给机构的微动特性,结果表明库仑摩擦和微弹性现象是滚珠丝杠在微动条件下的主要运动特性.针对这一特性,提出了一种基于误差的增益自适应控制器,该控制器能够有效地提高系统的稳定性,并能保证足够的控制精度.对幅值为1μm的正弦输入,其跟踪控制误差小于0.04μm.对幅值为1mm的正弦输入,其跟踪控制误差为0.5μm.

Ultra-precision positioning and tracking using ballscrew

Ultra-precision machining requires high motion resolution. The nonlinear factors and stability are two ma- jor factors to be faced in designing ultra - precision controllers. The design of the machine motion controller is very important in ultra-precision machining. A ballscrew driving stage with resolution of 5 nm and the micro movement characteristics of this mechanism have been researched, respectively. The mechanism is a nonlinear system in micro movement condition. A controller named gain self-turning controller based on motion error (GSTCBE) is also pro- posed, which has been proved to be more stable than traditional PID controller. The controller is charaterized by higher tracking accuracy in micro and macro motion scope.