A New Method Based on Position Sensitive Detectors to Measure Four-Degree-of-Freedom Geometric Errors of Linear Guide Rails

摘要

A novel method adopting position sensitive detector (PSD) and laser collimation technique to measure four-degree-of-freedom of linear guide rails is presented in this paper. The yaw and pitch errors can be obtained based on the relationship between output coordinates of horizontal PSD and angle of the mirror. Meanwhile, the horizontal and vertical straightness errors can be calculated by the relationship between output coordinates of vertical PSD and position of sampling points. Besides, BP neural network algorithm is used to correct the nonlinearity between actual and ideal output of PSD. The method is analysed theoretically in detail. The experimental results show that the four-degree-of-freedom of linear guide rails can be measured with high accuracy.