精密平面定位技术

Research on precision plane positioning

针对精密平面定位影响因素多、控制复杂及定位困难等问题,提出了一种新的精密平面定位方法,该方法采用激光莫尔技术,以上下2组100μm的衍射光栅作为定位标记,通过微机闭环控制,可实现XYθ三自由度的全自动精密平面定位.2组光栅相位相差180°,构成差动光栅技术,可有效提高位置检测信号灵敏度及定位精度.系统在软、硬件方面采取的一系列抗干扰措施,确保了较高的定位精度及工作可靠性.实验结果表明,基于激光莫尔信号的精密定位装置可获得亚微米级的平面定位精度,对精密加工工程等领域具有重要的实用价值.

Moire´ technique is adopted and alignment marks are used in the form of 100 μm pitch gratings. Based on these, the automatic precision plane alignment in X-Y-θ can be achieved using computer controlled Moire´ technique. Two sets of diffractive gratings with a phase difference of 180° form a differential grating and greatly improve the sensitivity of position signals and positioning precision. A series of anti-interference step in the hardware and software of the device effectively improve positioning accuracy and reliability of the device. The experimental results show that the apparatus based on Moire´ signal can achieve plane positioning accuracy of the order of sub-micron. The method is of high value for the advancement of precision manufacturing technology.