Wheel Inclination Detection is the Key of Front-wheel Orientation. The high precision and efficiency are required in this detection, but it's impossible by manual way. This article develops an Inclination Detection System which avoids the defects of manual detection and achieves the goal of the Inclination Detection by using the digital image processing technology. From the application perspective, we can get a special rectangular template, which has four circles on it, then put it on the wheel vertically. Collect a picture with a CCD which parallels the horizontal line. After a picture pretreatment, Trapezoid Distortion Correction Method (which also known as Two Steps Projection Method) is used to correct the picture in inclination range. Then extract characters and check the figure in the picture by Hough Round Check. If the figure is a circle, it can be sure the inclination is found.
