点激光测头激光束方向标定

为了使点激光测头能在任意方向上实现测量功能,提出一种逆向工程中标定激光束方向的方法,设计了一种标定面方向可调的标定块配合标定。标定过程中,让激光测头在标定面上分别沿X、Y、Z3个轴方向做等间距运动,根据进给步长与激光束长度变化量之间的关系确定激光束的方向。以三坐标测量机为平台,给出了以任意方向安置点激光测头时,测量值从传感器坐标系到基准坐标系的转换过程,并对标定算法及整个标定过程进行了详细描述。最后,通过与接触式测量进行对比实验,验证标定后点激光测头的测量效果。实验结果表明,用该方法标定的点激光测头在3σ范围内沿任意方向的测量误差为(0.0452±0.0168)mm,满足逆向工程的测量要求。

Calibration of laser beam-direction for point laser sensors

A new calibration method of laser beam-direction was presented to implement any-orientation measurement for point laser sensors in reverse engineering. A calibration block whose calibration surface could be adjusted was designed to co-operate the calibration approach. During the calibration, the point laser sensor steped in an equal distance along X、Y、Z axes in the calibration surface, then the laser beam-direction could be confirmed according to the relationship between the stepping size and the length change of laser beam. Based on the CMM platform, the coordinate transformation process from the sensor coordinate system to the reference coordinate system was deduced when the point laser sensor was set in any-orientation, and the calibrating process was introduced in details. Finally, a comparison experiment on contact measurement and point laser measurement was carried out to verify the proposed method. Experimental results indicate that the error of the point laser sensor calibrated by the proposed method is (0.045 2±0.016 8) mm, which can satisfy the requirements of sampling accuracy in reverse engineering.