Abstract: As to the imaging filed limitations of the vision measuring system for blade-shaped holes,an image mosaic method based on accurate coordinate control was proposed to derive the panoramic image through the local backlighting images.The mathematical model was established to realize successive mosaic procedure of the adjacent local images through rigid transformation,in which the mosaic matrixes were computed by the related hardware parameters such as actual translation distance and equivalent size of pixel,etc.The method consists of calculation of the number of local images,capture of local images,computation of mosaic matrixes and generation of panoramic backlighting image of the blade-shaped hole,etc.Moreover,taking no account of the image information and overlap,the method possesses simple and low computation in image mosaic.To verify the function realization of the image mosaic method,a test piece of stator outer ring was selected as the target and the blade-shaped hole distributed on it was measured by the system to derive its panoramic image and profile data,which manifested the feasibility and effectiveness of the mosaic method for backlighting images.

Key words: Image measurement, Motion control, Image mosaic, Blade-shaped hole