高精度贴片机多吸嘴位姿误差分析与标定算法

Position Error Analysis and Calibration of Nozzles in High-precisionchip Mounter

高精度贴片机吸嘴部件由于机械加工装配会产生位姿误差,由此对吸嘴的位姿误差进行理论建模与分析,提出了一种多吸嘴位姿误差标定算法。机器视觉采集图像计算及坐标变换得出吸嘴各个自转角度下的基坐标,利用最小二乘法计算出吸嘴的自转圆心和半径。通过实验,对吸嘴旋转目标位置进行坐标计算,与转动之后实际位置坐标进行比较,其误差小于±50μm,表明标定方法满足元件贴装精度要求。

The nozzle of precision SMT can't be perpendicular to the mounting plane due to manufacturing and assembly errors,this paper present a auto calibration method of nozzle position error. First,make a theoretical model of nozzle's pose to analyze the nozzle's position error,using machine vision to acquire images and calculate nozzle's image coordinates,then get nozzle's physical coordinates by coordinate transformation during the process of nozzle calibration. Fitout center position and radius of nozzle self rotation circle. The paper did experiments on above theory,predicting nozzle's real physical coordinates after self rotate a certain angle. The experiment result out an accuracy less than ± 50μm,which satisfy the component placement's requirements.