Size measurement of shaft component based on computer vision

Dynamic measurement of shaft component external appearance is implemented through the method of mechanical visual non-contact measurement. The edge of the image is primarily located by using sobel operator when the visual image of shaft component is gained. Based on this, the edge subprixel location can be achieved through the least square method to fit those discrete points on image edge. The size is determined on the precise analysis when the error is minimized. The size of the component is exactly calculated after the calibration coefficient k is gained. Through the comparison between the elements of the detected shaft components and the complete shaft components, deficiencies on the surface can be obtained. The experiment shows that the measurement precision is greatly improved and the error is less than ±15um under the condition that CCD camera is 1392×1040 and the pixel size is 4.65um.