基于光斑形状光束快速自动准直算法

The Fast Algorithm of Auto-lalignment Based on Spot Shape

为满足高功率激光装置光路自动准直系统的高精度要求,提出一种光束非垂直过孔状态下椭圆光斑的光斑差值快速调节法,并引入局部自适应阈值二值化算法提高准直图像的定位精度.当椭圆光斑长短轴差值较大时,利用基于最小二乘法的椭圆拟合改进算法,求出椭圆光斑长短轴的轴长,通过远场反射镜调节长短轴轴长差值以调节光斑形状,直到获得规则的圆形光斑.分析了圆光斑中心与基准位置的偏差值,将差值转为闭环控制的步进电机调整步数,实现了高功率激光装置光束的快速自准直.该算法应用在某高功率激光装置光路自动准直系统中,结果表明,远场指向精度优于0.033″,优于目前高功率激光准直系统准直效果,提高了激光光束的指向性精度.

To meet the accuracy of the high power lasers auto-alignment system, a new method of elliptic light spot differential quick adjustment in the state of non-vertical was put forward, introducing the local adaptive threshold and binarization algorithm which improve the auto-alignment system positioning accuracy of the image .When the axle differential is big the ellipse fitting based on least square method is improved to calculate the length of ellipse light spot major axis and minor axis, and to adjust the far field reflector to shape the light spot to get the regular circular spot, and then to calculate the deviation of circular light spot center and the reference center, which is transformed to the steps of closed-loop control stepping motor , achieving high power lasers beam auto-alignment, the algorithm is used in a high power laser facility auto-alignment system, the results show that the far field pointing accuracy is better than 0.033＂, which is better than the original system.