Study On Surface Machining Trajectory Planning Method Based On Milling Force Control

The rapid development of social economy has driven the development of the automobile manufacturing industry. In order to meet the aesthetic appearance and performance requirements of the car, the update speed of automotive panel die gradually increased. With the characteristics of the automotive panel die of large shape structure, uneven curvature and so on, the whole mold adopt a processing method will result poor surface quality and low efficiency. Meanwhile, those characteristics also increases the difficulty of NC programming of the automotive panel die. For this reason, this research mainly focus on the study of surface division, milling force modeling and tool path planning of the automotive panel die.In view of existing problems of the processing quality in the whole process for automobile covering parts. Slice division of complex surface by obtaining the principal curvature mean curvature and gaussian curvature of surface discrete data points and K-means clustering algorithm, combined with Voronoi diagram algorithm to extract the surface boundary, thereby the whole complex surface division can be determined.Based instantaneous rigid mechanical model for CNC milling complex mold surfaces crafts of ball-end milling, the unknowns of instantaneous rigid mechanical model can be determined. This study build the Tool-Workpiece osculatory regional model in which the simulation of the Tool-Workpiece osculatory regional model is employed by Matlab. Then the milling force model can be achieved.For the problem of the traditional tool path planning algorithm, ignoring the impact of physical factors on the whole machining process, only consider the geometric position relationship between the tool and the workpiece. Therefore, use the TSP problem which is solved by genetic algorithm to solve tool path planning. The machining direction which is a relatively small direction of the milling force change is employed to complete the tool path planning. Finally the simulation of tool path is determined by MATLAB software.Through the comparative test of the traditional processing methods and optimization algorithm to verify the correctness and feasibility of optimization tool path. Furthermore, optimization algorithm proves workpiece surface smoothness is better and the subjected average milling force in the process is smaller.