| With the wide application of freeform surfaces in automobiles,ship-buildings,aerospace and other fields,the quality inspection of parts which containing freeform surfaces has become an indispensable stage in the product design and manufacturing process.In recent years,the demand for high efficiency and high quality inspection of parts is rapidly increasing.Therefore,how to carry out efficient and high-precision automatic measurement of parts with complex surfaces has become an urgent problem.In order to solve these problems,the measurement feature classification method based on the CAD model is proposed,and a fast interactive picking system for complex surface has been developed in this thesis.The main research contents of this thesis are as follows:(1)A fast interactive pickup method for complex surfaces is developed.The imported CAD model can be freely picked up along the mouse path,and the accuracy and delay of picking are guaranteed.(2)A feature classification algorithm for complex surfaces based on region growing method is proposed.According to the measurement characteristics of the line scanner and the modelling method of the complex surface,sweep direction and sweep guide direction are generated,and the adjacent surfaces with features similar to the seed surface are merged to form the feature class conforming to the measurement method.(3)According to the result of feature classification and the scanning principle and related constraints of the line scanner,the scanning position and scanning direction of the probe in space are calculated,and the final scanning path is formed by connecting them end to end.(4)A method for unifying virtual and real positions is proposed.The workpiece coordinate system in the host computer software is combined with the coordinate system at the end of the robot in reality,and the scanning path is simulated in a simulation software.Finally,the path is converted into a file that can be executed by the industrial robot. |
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