Computer Vision Testing System For The Gauge With Pointer

As one of the measurement instruments, the gauge with pointer is generally used in the manufacturing process at present. There are many kinks of gauge with pointer including pressure gauge, dial gauge, micrometer gauge, automobile gauge and so on. Because they are convenient for use and have low costs, they are popularly used by people. But they also had to be tested after being made or used for a long time so that to insure they are eligible. Traditionally, the gauges are tested by human eyes. However, some of the subjective factors such as: observation angle, observation distance and fatigue may have effects on the value. This method will lead to not only gross error and small reliability but also low efficiency and body fatigue.In this paper, aimed to this laggard condition, the author used the method based on computer vision technology to test the gauges, analyzed the gauges' characters and designed the blue print to pick-up the pointer. The pointer was droved by step motor witch was been controlled though PC parallel port and the images were captured by a CMOS camera. The program was wrote by visual C++ and the testing was realized finally.The computer vision and image processing technology being used in the exact measurement is a new method, and it has many good points such as: high precision and efficiency. This method will be widely used in the future.