平面反射式二维光栅测量系统研究

Research on Reflective Two-Dimensional Grating Measurement System

针对超精密运动台的二维亚微米级精度同步测量需求,提出并建立了平面反射式二维光栅测量系统,研究了平面反射式二维光栅的平面位移同步测量方法,分析了平面反射式二维光栅测量系统的误差传递模型。通过Vold-Kalman滤波算法,对光栅信号中存在的高次谐波误差、幅值/相位误差进行实时修正和滤除。采用反正切细分算法和周期测量法对光栅正交脉冲的频率进行测量,实现对被测目标的高分辨率测量和实时运动速度测量。同时,构建了亚微米级测量精度的平面反射式二维光栅测量系统,测量范围为500 mm×500 mm,x、y方向的定位精度为±0.3μm,测量分辨率为0.005μm。

Aiming at the requirement of twodimensional submicron precision synchronous measurement for ultraprecision motion stage,a reflective twodimensional grating measurement system is proposed and established.The synchronous measurement method of plane displacement of reflective twodimensional grating is investigated,and an error transfer model of reflective twodimensional grating measurement system is established.Through VoldKalman filtering algorithm,the highorder harmonic error and amplitude/phase error in the grating signal are corrected and filtered in real time.An arctangent subdivision algorithm and period measurement method are used to measure the frequency of the orthogonal pulse of the grating to realize the highresolution measurement and realtime speed measurement.A reflective twodimensional grating measurement system with submicron measurement accuracy is constructed,in the measurement range of 500 mm×500 mm,the positioning accuracy of the xdirection and ydirection is±0.3μm and the resolution is 0.005μm.