【摘要】 介绍了一种采用叠栅信号实现超精密定位的定位方法,首先建立了衍射叠栅信号和相对位移关系的数学模型,并在MATLAB仿真软件的辅助下完成了对其定位特性的研究.探讨了光栅倾斜对定位精度的影响,倾斜角越大,定位点的偏移越大,为确保高的定位精度,光栅的倾斜角度必须控制在一定范围之内.研究发现激光束束径和莫尔信号之间存在一定关系,当激光束直径为光栅常数的11倍及以上时,激光莫尔信号几乎不受外界干扰的影响,此时能够达到更高的定位精度.同时,分析了不同光栅常数对定位精度、定位行程的影响,并进而提出了粗光栅与细光栅相结合的两段式复合定位技术,可使定位装置在较大的行程范围内实现高精度定位.实验表明,采用衍射叠栅信号的超精密定位可获得±10 nm的定位精度.更多还原

【Abstract】 A measure to realize ultra-precision position based on Moiré signal is introduced. Firstly a mathematical model is established with respect to the diffraction double gratings and the relative displacement. And then study is conducted about the characteristics of position by using simulation software. Also the impact about position precision made by grating tilted is discussed. The result indicates that the larger tilt angle is the more anchor point offsets. So tilt angle of grating must be controlled in a certain range so that the higher positioning accuracy can be ensured. The relationship between Moiré signals and the laser beam diameter is studied,and it shows that when the laser beam diameter is 11 times more than the grating constant,the signal of laser stacked gate signals is difficult to be interrupted by interference noise. In this case,higher positioning precision is likely to be easily reached. Addition,the influence that different grating constant made on position accuracy and orientation schedule is analyzed,and then a technology of two-stages compound positioning of coarse and fine grating is raised up,which can make the positioning device realize higher position precision in a larger range. The experimental result shows that the fold grating signal can perform positioning accuracy of ±10 nm.更多还原