The application of laser and CCD compound measuring method on 3D object detection

Being one of promising development trends of coordinate measuring machine(CMM), non-contact measuring model has been paid more and more attentions, which is especially suitable for those soft, fragile and easy-deformed workpiecs. CCD camera has pretty high precision for 2D image measurement and can capture plenty of information each time. Meanwhile, the laser probe can achieve very high precision in the axial direction. Combining with the both advantages, the compound probe including laser probe and CCD is assembled with a bracket. The axial position relationship of laser probe and CCD can be obtained by means of calibrating the position of standard ball centre. Therefore, the data inspected by laser probe and CCD can be transformed into the same coordinate system and the 3D detection of workpiecs could be realized rapidly. In order to further improve the accuracy of data processing, an optimization algorithm named quasi-Newton method is employed. Information captured by CCD is used as partial initial conditions, which prevents occurrence of local optimization due to inappropriate initial parameter selection of quasi-Newton method. The experimental results demonstrate the validity and robustness of compound measuring method.