被测表面特征对激光测头特性的影响

STUDY ON INFLUENCE OF SURFACE PROPERTIES ON CHARACTERISTICS OF LASER TRIANGULATION PROBE

提出了基于坐标测量机、激光三角法测头、测头回转体的自由曲面非接触扫描测量方法 ,其中激光测头的输出值受被测表面的粗糙度、曲率以及颜色等特征的影响 ,存在相应的误差 .为了减小这些误差 ,对其影响规律进行了实验研究 .结果表明 ,表面粗糙度值太低 ,测头不能完成测量 ,原因是表面存在较强的镜面反射光 ;曲率越大 ,测量误差越大 ,因为光斑区域内的表面平均高度变化加大 ;颜色越深 ,测量误差越大 ,因为漫反射光信号过弱所致 .

Based on a coordinate measuring machine,a laser triangulation probe and a probe head,a method for non contact measuring free form surfaces is proposed.The readings of the laser probe may be influenced by properties of the surface,such as roughness,curvature and colors.It is hard to measure the high reflecting surface because of specular light.The reading errors increase with the increase of the curvature for average effect,it is also true with the darkening of the colors as the diffused light is too weak.