Machine vision inspection system for automobile gauge panel

A machine vision inspection system is designed and built for automatic inspection at the end of automobile gauge panel production line. The inspection items on the gauge panel are pointing errors on all scales of 5 indicators and possible damage or missing assembled warning lights and light bulbs for indicators. Image acquisition camera is set to have a small field of view, a CNC system is established to drive the camera focusing on any target on the gauge panel. The position of the camera is close-loop controlled by a image character feedback control strategy. Automatic calibration is performed by using a stochastic adaptive control scheme. A two-CPU computer system is established to assure real time image processing and CNC control as well as test signal source management working in parallel way. Precision test signal source for speedometer, petrol gauge, oil pressure indicator, water-thermometer and rheometer are designed and made integrated under computer management and control. Each scale and pointer on the gauge panel has a set of image processing parameters, therefore a learning sequence method is designed to reduce programming load and increase flexibility which allows quick adaptation to various products inspection.