利用补偿提高精密定位平台的定位精度

Improvement of positioning precision for precise stage with compensation

运用反相补偿法原理,从误差曲线中分离出系统误差并与其反相曲线叠加以消除系统误差的影响。给出了对精密定位平台宏动工作台和微动工作台进行补偿的具体实例,补偿后定位误差分别从17.4μm改善到1.3μm和从137.6nm改善到22.2 nm。理论分析和实验结果表明,反相补偿法对于降低系统误差十分有效,但对于随机误差效果不佳。

To improve the positioning precision for precise stage,the error curve of a precise stage was measured and the system error was separated from the error curve to match negatively the reverse curve to remove the system error effect. A compensation example was given. The positioning stage described has a 2-layer structure, the lower one is a macro-stage and the upper one is a micro-stage. The macro-stage is driven by a precision ball lead-screw and positioned by an optical grating, and the micro-stage is driven by PZT and positioned by an inductance sensor. After compensation,the positioning precision of the macro-stage is improved from 17.4μm to 1.3 μm and the precision of micro-stage is improved from 137.6 nm to 22.2 nm, which accomplishes nano-scale positioning successfully. The experimental results show that the reverse compensation method is effective to remore the system errors, and on the other hand, it shows that the method is not very good at removing the random errors because it is impossible to find the reverse curve to match it.