点光源测头光束方向的标定

Calibration of Light Beam's Direction of Point Light Source Probe

指出在采用点光源测头测量物面测点坐标时 ,因光束方向相对于机床坐标系的安装偏角而引起的测量误差问题。提出了一种标定光束方向的方法。设计 V形块做标定的靶标平面 ,通过在 V形块随各坐标轴做等距移动时采样 ,实现了点光源测头光束方向的标定。给出了标定光束方向后的测点坐标计算方法。并设计了仿真程序验证了该方法的可行性。仿真结果表明 ,当测头精度为 0 .0 1m m,光栅尺对机床位移的检测精度为 0 .0 0 2 mm时 ,光束方向的标定误差可以控制在 0 .

When point light source probe is used to digitize tilted surface, measurement error occurs for there is assembly angular error between beam's direction and machine tool's coordinate system. A method is presented to calibrate the beam's direction. With this method, the beam's direction can be calibrated out with data collected while moving a V-block along each of the x, y and z axis of machine tool step by step. A method is presented to calculate the inspected points' coordinates with the calibrated beam's direction. The applicability of this calibration scheme is verified by simulation. The simulation results show that the calibration error is within 0.1mrad when the probe's accuracy is 0.01mm and the optical sensor's accuracy for detecting axis displacement is 0.002mm.