Study On Principle And Technology Of Measurement Of Grinding Wheel Envelope Profile Based On Image Processing

It is used the ideal grinding wheel profile to calculate grinding wheel path in the routine method, and the manufacturing errors of grinding wheel and wear is a greater impact on machining precision. Moreover, there are high demands on the precision of grinding wheel dressing. To solve the problem, the CNC machining technology of complex surface based on grinding wheel envelope profile is studied. By the technology of tool path calculation based on grinding wheel envelope profile, the shape error of the wheel has little effect on the machining accuracy, and the grinding accuracy is improved. For measuring the grinding wheel envelope profile has become a core technology, the method based on digital image processing is presented.The grinding wheel envelope profile is the shape leaved on the templet, which is hypothetical no thickness, when the grinding wheel are rotating around its own axis on the machine. It covers the dimension and shape error of the grinding wheel and grinder spindle error, and it is the effectiveness shape during the grinding. The grinding wheel envelope profile is re-mapped to the templet, and the measurement of the grinding wheel envelope profile is changed into the flat shape—measurement of the templet.The grinding wheel envelope profile measurement system is designed according to actual needs. The working principle of this system is that an image of grinding wheel envelope profile shot by CCD camera is transported into the computer, then the image is treated by Matlab, finally the geometrical parameters of the grinding wheel envelope profile is outputted. Software module is an important part of the whole measurement system for it is the key factor that influences the measurement precision. Several image processing algorithms are mainly studied, including image segmentation, edge detection and subpixel edge location. The pixel is subdivided by bilinear interpolation, and the edge of the image is estimated by the Canny algorithm after comprehensive comparison of the various edge detection algorithm. Then the edge curve is fitted by cubic spline function.The experimental results show that the principle is correct and the method is feasible. The grinding wheel envelope profile is the effectiveness shape during the grinding, and it provides a reliable for tool path calculation. This method has a very wide future in measuring and tool path calculating of rotary cutter.