激光标刻系统几何失真的校正方法

Geometric distortion correction for laser marking system

激光标刻系统的复合几何畸变并非其固有缺陷,畸变产生的原因在于简化的、近似的系统控制策略。依据扫描振镜的扫描几何公式,采用最速下降法解算了扫描振镜偏转角度的数值解,实现了目标标刻坐标到扫描振镜偏转角度的精确映射。在扫描振镜偏转角度数值解的基础上,利用扫描振镜复合几何畸变的对称特性性,通过在第1象限建立适当规模的误差校正表并采用插值算法进行失真校正。仿真实验结果表明,该方法能够在4象限实现满足精度要求的失真校正。通过将目标标刻坐标转换为归一化坐标,使得该校正方法对于不同焦距的扫描振镜具有广泛的适用性。

Geometric distortion is not the inherent defects of the laser marking system.The reason of is that the distortion is produced by a simplified or approximated system control strategy.Based on Geometric formulas of scanning galvanometer,the steepest descent method is used to solve the numerical solution of the scanning galvanometer deflection angle.The precise mapping is achieved from the target marking coordinates to the scanning galvanometer deflection angle.Based on the numerical solution of the scanning galvanometer deflection angle and the symmetry properties of the complex geometric distortion of the scanning galvanometer,the appropriate scale error correction table is established in the first quadrant,the interpolation algorithm is used to correct the distortion.The simulation results show that this method can be implemented in four quadrants to meet the accuracy requirements of the distortion correction.By converting the target marking coordinates into the normalized coordinates,this correction method is applied broadly to the scanning galvanometer with different focal length.