基于机器视觉的变速箱拨叉轴孔尺寸检测方法

Method of Shaft Hole Size of Gearbox Shift Fork Based on Machine Vision

为实现变速箱拨叉轴孔尺寸检测,提出一种基于单目机器视觉的在线检测方法,实现拨叉轴孔内外径、同心度、轴孔空间相贯性检测。该方法首先对轴孔图像进行滤波、图像增强、边缘检测,提取感兴趣区域内轴孔轮廓和侧壁孔轮廓,拟合顶圆和底圆轮廓,使用标定数据计算轴孔尺寸,通过单目相机小孔成像原理检测轴孔和侧壁孔的空间相贯尺寸。经实验,该方法能够检测变速箱拨叉轴孔的实际空间尺寸;内外径的偏差为0.049 mm;同心度的偏差为0.0485 mm;空间相贯尺寸的投影偏差为0.0428 pixels,能够达到生产厂商的检测标准要求。

An on-line detection method based on monocular machine vision is proposed to detect the size of the shaft hole of the shifting fork in the gearbox,which can detect the inner and outer diameter,concentricity and spatial intersectionality of the shaft hole.This method firstly filters,enhances and detects the shaft hole image,extracts the shaft hole contour and the sidewall hole contour in the region of interest,fits the top and bottom circle contour,calculates the shaft hole size using calibration data,and detects the spatial intersecting size of the shaft hole and sidewall hole through the keyhole imaging principle of the monocular camera.The experiment shows that the method can detect the actual space size of the shaft hole of the gearbox fork.The deviation of inner and outer diameter is 0.049 mm;The deviation of concentricity is 0.485 mm;The projection deviation of space intersecting size is0.0428 pixels,which meets the requirements of the manufacturer’s detection standard.