高功率激光器自动准直系统图像处理的可信度评估

Evaluation of reliability for image processing of high power laser's automatic alignment

自动准直系统是将采集的图像进行特定算法处理获取光束的位置信息,驱动电机调整光斑到指定的位置,其中图像质量对光束定位的精确性影响很大,为尽量避免受严重噪音和光束畸变影响的图像进入图像处理流程而产生准直结果的错误判断,保证自动准直系统图像处理结果的精确性,试图提供一种较为简单的判断依据,采用基于Monte-Carlo模拟方法,建立了远场准直过程中三种主要噪音的干扰评估模型,以测量不确定度作为定量判断处理图像与否的特征参数,将该结果做成统计图表作为判断依据。结果表明,在设定合理测量不确定度阈值的情况下,该特征参数能够较好地排除不良图像,从而提高准直结果的可信度。

The automatic alignment system is a large system that obtains the beam position by processing the images with particular image processing algoritbm, and the position information ix used to drive the motors and adiust the beam to the speci- fied position, however, the image quality has a great influence on the accuracy of beam positioning. To avoid the images seriously affected by the noise and beam distortion entering into the automatic alignment process which could generate the misjudgement of alignment results, and to ensure the accuracy of image processing rcsults, this paper tries to describe a simple method to recognize these images, and three main far field noise evaluation models are established based on the Monte-Carlo simulation. The uncer- tainty of measurement is regarded as the characteristic parameter to determine whether the image should be processed, and we plot the parameter results to a statistical chart as judgement condition. The experimental results show that, in the case of setting a reasonable threshold, the automatic alignment systems can reject most of the not-good images, and greatly improve the reliabili- ty of the alignment system.