激光跟踪仪测角误差标定及补偿

Calibration and compensation of angular error in laser tracker

激光跟踪仪采用单站极坐标测量原理,将高精度激光测距技术和经纬仪精密测角技术相结合,实现大尺寸(50 m)空间三维坐标点的高精度测量.激光跟踪仪采用的增量式测角圆光栅是一种集光、机、电为一体的非接触式数字测角系统,具有结构简单、测角精度高、响应速度快等特点,已被广泛应用在精密角位置的测量设备中.通过分析增量圆光栅的制造误差、电子学细分误差、轴系旋转误差,码盘安装偏心误差对编码器测角精度的影响,在测角误差标定的基础上,通过傅里叶分析建立测角误差补偿模型,通过误差补偿使得单头读数测角均方误差由10″提高至0.8″以内,并与双头对径读数测量结果进行比较,测量精度略低于双头对径读数优于0.3″测角误差.

Following polar cordinate mesuring method with single apparatus,and combining precise laser ranging technology and high-accuracy angular measure technology,Laser tracker have excellent ability in large-scale metrology.Angular mesure system adopt with rotory grating,which is a non-contacat digtal measure system integyal with opical,mechanical and electronic tcehnology.Accompanied with simple structure,high precision and fast measure speed,rotory grating have widespread used in epuipment of precision angular measurement.According to analysis all type error of rotary grating such as dividing error in manufacture,subdivision error in electroncis,wobbling of shaft and eccentricity of grating in mounting,a error compensation model were established through Fourier analysis method,adopted this compensation,the angular error reduced form 10 arc-second to 0.8 arc-second measured by one grating readhead,this measuring accuracy correspondent to diametrical measurement by two grating readhead,which characteristic ultra-high accuracy of 0.3 arc-second.