振镜激光扫描测量系统误差分析与补偿

Error Analysis and Compensation of Galvanometer Laser Scanning Measurement System

振镜扫描系统因其具有高速和高精度等优点被广泛应用于激光快速成型、激光精密打标和激光扫描测量等诸多领域,但因振镜系统的引入而存在系统测量误差。鉴于此,首先搭建线激光一维振镜扫描系统并采用双棋盘格标定板的标定方法对系统进行标定,然后建立系统的误差模型并对扫描过程中的测量误差进行理论分析,最后针对振镜转角误差提出一种基于查表法的补偿方法。实验结果表明,当测量工作距离为250 mm左右时,误差补偿后,中心距离的方均根误差从0.733 mm降低至0.061 mm,标准差从0.200 mm降低至0.060 mm,说明该方法能够显著提高系统的测量精度和鲁棒性。

Galvanometer scanning systems are widely used in various fields such as laser rapid prototyping, laser precision marking, and laser scanning measurement for their high speed and precision. However, system measurement errors are induced because of the introduction of a galvanometer system. In view of this, firstly, a linear laser one-dimensional galvanometer scanning system is built and calibrated by the double-checkerboard calibration method. Then, the error model of the system is established and the measurement error in the scanning process is theoretically analyzed. Finally, a compensation method based on the table look-up method is proposed for the galvanometer rotation error. The experimental results show that when the measuring working distance is about 250 mm, after the error compensation, the square root error of center distance decreases from 0.733 mm to 0.061 mm and the standard deviation from 0.200 mm to 0.060 mm. It follows that this method can significantly improve the measurement accuracy and robustness of the system.