振镜式激光扫描误差分析及几何校正算法

针对如何提高振镜式激光扫描的扫描精度,特别是当扫描区域较大时的精度问题,文中展开了对振镜式激光扫描时图形畸变原因的分析,并对每一种误差产生的原因提出了校正补偿的办法.综合各种误差补偿办法,建立了一个基于平面坐标变换几何校正算法原理的图形畸变校正模型.此模型校正算法采用VC 6.0编程,应用于快速成形粉末烧结系统,结合激光扫描边长为300cm正方形时的试验数据和畸变特性,对畸变关系式作了进一步的改进.由于此公式反映的是理想点和畸变点的地址映射关系,所以,当激光扫描时,X方向和Y方向上的扫描数据经过此校正模型后都会动态的发生变化,从而保证激光的扫描精度.

Error analysis of laser galvanometer scan system and its geometrical correction arithmetic

In order to improve scan precision of the laser galvanometer scan system,especially when scan area is large,the reasons of graphic distortion are analyzed in this paper when the laser galvanometer scan system is running,and the whole bag of compensating tricks are put forward for every reason of corresponding graphic distortion. As a result,considering all kinds of methods of error compensation,a kind of calibration model of graphic distortion is established based on geometrical correction arithmetic of plane coordinate transformation. The calibration model is programmed by VC 6.0 and is applied to select laser sintering system of rapid prototyping. The model combines with the distortion characteristic and scan data of scanning 300cm square in width. Because the address mapping of ideal points and distorted points is reflected in the calibration model,the scanning datas in the direction of X axis and Y axis are dynamically varied to ensure the scan precision of the laser galvanometer scanning system.