Vision Sensor based on Simultaneous Imaging from Two Directions for Inspection of Painted Automotive Body Dimensions

In dimension inspection of painted automotive body, the conventional method using slit light cannot detect the shape of edges of adjacent body parts. Thus the conventional method is not able to measure accurately the gap of between body parts. A new vision sensor based on simultaneous imaging from two directions has been developed. The sensor has a imaging unit. The imaging unit is consisted of a slit light source, a TV-camera, two triangular mirrors and four plane mirrors. The two edge of facing body parts are observed respectively from upper left and upper right directions by the imaging unit. Thus the TV-camera of the imaging unit is able to take simultaneously two edge images. At this time, in the TV-camera image, the overlapping of the two edge images occurs. We analyzed the characteristic of the overlapping of the images and showed the design index to get the clear edge images. The sensor used the imaging unit measures the gap and flushness with accuracy of within ±0.1mm without the influence of the shape of body edge.