测试设备位姿失调对自准直仪法测量圆分度误差的影响

Influence of test equipment pose error on dividing error measurement based on autocollimator

为了提高圆分度仪器分度误差的测量精度,介绍了用多面棱体自准直仪测量分度误差的原理和方法,对影响测量结果的误差源进行了分析。根据测量原理建立了多面棱体和自准直仪坐标系,利用坐标变换分别建立了多面棱体工作面与受检仪器轴线的平行差、自准直仪光轴与多面棱体工作面不垂直度误差、自准直仪电十字竖线与受检仪器轴线的平行差对分度误差影响的精确模型。在实验室内,以单轴位置转台的定位精度为测试对象,设计了以上三种位姿失调误差模型的验证实验,实验结果与理论模型仿真结果具有很好的一致性,三种位姿失调引入的误差实测值与理论值的最大偏差小于0.9″,验证了位姿失调量引入测量误差模型的正确性,该模型及仿真结果可以准确指导圆分度误差测试。

In order to improve the measurement accuracy of dividing error of encoders,the principle and method to measure dividing error by using angular polygon and autocollimator were introduced,and the error sources were analyzed.According to the measurement principle,coordinate systems of angular polygon and autocollimator were established. Utilizing the method of coordinate transformation,precise mathematical models were deduced for indicating the relationships between dividing error and misalignment errors,such as parallelism error between the angular polygon working surface and the axis of the tested unit,perpendicularity error between autocollimator optical axis and the working surface of angular polygon,parallelism error between vertical wire of theautocollimator and the axis of the tested unit.In order to verify the error models of misadjustment,three experiments were performed in the laboratory,taking the positioning error of a single-axis position turntable as test object.The experimental and theoretical results have good consistency and the maximum deviation was less than 0.9″,which indicate that the error models of misadjustment are applicable to guide dividing error measurement.