Research On Disk Cam Profile Detection Method Based On Image Processing Technology

Due to the irregular contour, high dependence on the number of measuring points, uncertainty of the starting point, the contour detection efficiency of the cam is low for a long time, which greatly restricts the production and application of the cam. Based on image processing technology, the cam profile detection system is designed. Processing methods of the cam image, acquisition and calculation methods of main parameters, are explored. Finally, the software platform of the detection system is developed and tested.According to the experimental analysis of the treatment effect of various denoising methods, the combination of median filtering and bilateral filtering is selected to achieve the optimal combination of the edge preservation and noise removing of the cam image. The characteristic region of the cam is extracted, using connected region detection method. Through the experimental analysis of edge detection methods, an improved Canny edge detection method is proposed, to optimize the edge extraction effect of the cam.Generally, the cam profile measurement includes the determination of the measurement datum and the calculation of the lift error. The parameters that need to be obtained for the cam profile detection are the cam profile and phase information. A new method is proposed to obtain the cam phase, that initial adjust according to the overall posture of center hole's contour for the first step, fine adjust based on precise linear fitting result of keyway contour points for the second step, then determine whether or not the calculation has been completed. The rotation center coordinate is calculated, and the contour point information is extracted, too. The lift error is calculated, by using chordal deviation method to select data, using two times Lagrange interpolation method to resample.On the basis of the existing image detection system, the cam profile image detection system is designed, according to the cam contour detection tasks and requirements. With the development platform and tools such as Microsoft Visual Studio, Open CV, Access, the software of cam profile image detection system is developed. Using simulated detection images, the software is tested to evaluate the accuracy of the software objectively. The test results show that the maximum contour detection error is less than one pixel.