Color matching is a newly emerging technology in coatings industry;and the accuracy of color matching has been a problem to which colorist pays lots of attention.

The method of determining the size of fitting ring in time of reaching assembly precision with fitting assembly method has been studied, two formulae for calculation of the size of fitting ring have been gotten.

On the basis of constructure character of universal_joint cross couping,This paper analyses assembly method of universal_joint and axial socket hole,designs a kind of assist technological equipment to improve assembly method and raise assembly precision.

This technique forecasts the products assembly precision and assistants designers to get corresponding optimum assembly process to pre-control the products quality before the actual assembly.

Base on the in-situ measurement and control of the assembling accuracy of chain -drawingoil machine, the measuring method of these physical parameters including relative plane, parallel of the plane, line, parallel of the line,and coplane of the line is studied, and a set of laser measuring system with high accuracy, wide-range application, easy operation is developed.

When matching position m=0,the matching accuracy at 10% t test level, with the correlation coefficient 0.

Gray correlation based minimum error and correlation coefficient algorithms were improved to eliminate the disadvantages of low matching accuracy and slow matching velocity existing in the image matching algorithms nowadays.