被动跟踪测量系统轴系误差补偿研究

Passive Laser Tracking Measurement Method and Error Compensation Technology

为了满足工业机器人空间精度的测量,提出了一种新型被动跟踪测量系统。分别对其轴系静态位置误差和方位转台中竖直轴的倾斜角度误差进行测量,然后通过与坐标测量机(CMM)进行比对实验,得到补偿前后被动跟踪测量系统测量精度的变化。首先,在对被动跟踪测量系统各轴系静态误差进行测量的同时,采用光电自准直仪对竖直轴的倾斜原始误差进行测量,并通过对原数据处理,去掉一次谐波分离出倾斜误差;然后,基于HTM方法建立从竖轴到末端标准球的误差补偿模型;最后,由坐标测量机带动被动跟踪测量系统进行空间点阵运动。实验表明,补偿前被动激光跟踪仪的测量精度为600 μm;经轴系静态误差模型补偿后测量精度为138.1 μm;加竖直轴倾斜误差补偿后测量精度为119.4 μm。由此证实,经补偿后的被动跟踪测量系统的测量精度有明显提高。

In order to measure the spatial accuracy of industrial robots, a new passive tracking measurement system is proposed. The static position error of the shaft system and the tilt Angle error of the vertical axis in the azimuth turntable were measured, and then the measurement accuracy changes of the passive tracking measurement system before and after compensation were obtained by comparing with the coordinate measuring machine (CMM). Firstly, when the static errors of passive tracking measurement system are measured, the original tilt errors of vertical axis are measured by photoelectric autocollimator, and the first harmonic is removed by processing the original data to separate the tilt errors. Then, an error compensation model from the vertical axis to the end standard sphere is established based on HTM method. Finally, the passive tracking measurement system is driven by the coordinate measuring machine to move the space lattice. Experimental results show that the measurement accuracy of the passive laser tracker before compensation is 600 μm. The measurement accuracy is 138.1 μm after compensating the static error model of warp shafting. The measurement accuracy is 119.4 μm after vertical axis tilt error compensation. It is proved that the measurement accuracy of the passive tracking measurement system is improved obviously after error compensation.