基于激光位移传感器的自由曲面精密测量方法

Precision measurement method of free-form curved surfaces based on laser displacement sensor

针对数据采集误差严重影响激光位移传感器(LDS)测量精度的问题,基于激光三角法测量原理,分析了激光束和会聚光斑质心对系统测量精度的影响,建立了定量计算LDS物面倾角误差和感光元件倾角误差的数学模型。采用该模型,可对LDS采集数据进行实时补偿。实验结果表明,引入两个补偿模型对测量结果进行修正后,不仅大幅提高了LDS的数据采集精度,使其测量误差控制在0.008 mm以内,而且提升了LDS在自由曲面中的测量精度。

This paper concentrates on the problem that data acquisition errors seriously affects the laser displacement sensor(LDS) measurement accuracy. Based on laser triangulation measurement principle, the impact of laser beams and convergent spot centroid on the system measurement accuracy is analyzed, and the mathematical models for quantitatively calculating LDS object plane inclination errors and image sensor inclination errors are established. Further, these models can be used to compensate for the data collected by the LDS in real time. The experimental results show that after introducing these two compensation models to correct measurement results, the data acquisition accuracy of LDS is greatly improved, the measurement error is controlled within 0.008 mm, and the LDS measurement accuracy on free-form curved surfaces is effectively boosted.