小型精密谐波转台角度定位精度标定与补偿

Calibration and compensation of small precision harmonic turntable

为了解决应用于关节型三维激光传感器的小型谐波转台角度定位精度标定的问题,提出了一种基于Renishaw双频激光干涉仪的单自由度小型谐波转台旋转角度测量和补偿方法。首先依据干涉仪角度测量原理和光路调节方法,建立了测量光路系统,分析了回转台装配误差对角度测量精度的影响并进行了有效调整,而后提出了小型谐波转台360°范围角度标定的实验方案,最后通过曲线拟合的方法分析了转台转角误差的测量数据,总结转台转角误差随位置改变的变化规律,并将误差补偿函数嵌入控制器中,对转台的每次运动进行实时有效补偿。实验结果表明使用该标定补偿方法能够将小型谐波转台的定位精度提高85%以上,补偿后的定位误差小于10″。采用该方法能够对小型谐波转台进行小间隔360°标定,标定后转台满足激光传感器空间精确定位的要求。

To solve the problem of angel positioning accuracy calibration of a small harmonic turntable used in a joint-type laser sensor, a method for measuring and compensating the rotation angle of a single-degree-of-freedom small harmonic turntable using a Renishaw dual-frequency laser interferometer was proposed. First, based on the interferometer angle measurement principle and optical path adjustment method, a measurement optical path system was established. Next, the influence of the assembly error of the rotary table on angle measurement accuracy was analyzed, and the rotary table was adjusted effectively. Then, a 360° range angle calibration experimental scheme for a small harmonic turntable was proposed. Finally, the curve fitting method was used to analyze the measurement data of the turning angle error, and the variation law of the turning angle error with the position of the turntable was summarized. The error compensation function was embedded in the controller to compensate the real motion of the turntable in real time. Experimental results show that the positioning error improved the positioning accuracy of the small harmonic turntable by more than 85%, and the positioning error after compensation is less than 10″. This method can be used to calibrate a small harmonic turntable with a small interval of 360°. The rear turntable meets the requirements of the laser sensor for accurately locating targets in space.