在激光扫描投影校准过程中,激光投影的光斑大小直接影响校准精度,进而影响投影系统的投影精度。为达到激光投影扫描系统对精度的要求,提出了一种能提高激光扫描投影精度的方法,即采用固定倍率准直扩束镜组和动态聚焦镜组相结合的方式,在减小激光束发散角和激光投影光斑的同时,使投影系统在投影工作距离上具有足够的焦深,以获得较大的激光能量密度,进而实现平场聚焦。利用ZEMAX光学设计软件进行了仿真并通过实验进行了验证,在4~5 m的工作距离上,激光束经过固定倍率准直扩束镜组及动态聚焦镜组后,有效减小了激光束发散角及投影光斑大小,提高了目标定位点上投影光斑的能量密度,最终使激光扫描投影系统满足了对投影精度的要求。

In the progress of laser scanning projection calibration, the accuracy of the calibration is directly affected by the light spot size of the laser projection, and then affects the projection accuracy of the projection system. In order to meet the requirements of the laser projection scanning system for accuracy, a method of improving the accuracy of the laser scanning projection is proposed. That is, the method of combining the fixed magnification collimation beam expander lens group and the dynamic focusing lens group reduces the laser beam divergence angle and laser projection spot at the same time, and the projection system in the projection of the working distance has sufficient depth of focus. Which can obtain a larger laser energy density, and then achieve the field of focus. The theoretical results are simulated and verified by using the ZEMAX optical design software through the experiment. In 4-5 m working distance, after the laser beam passes through a fixed radio collimating beam expander and the dynamic focusing lens group, it effectively reduces the laser beam divergence angle and projection light spot size, then improves the energy density of projection spot on the target locating point. Finally, the laser scanning projection system meets the requirements of the projection accuracy.