Optimization of tool axis vector for mirror milling of thin-walled parts based on kinematic constraints

Abstract

In the mirror milling of thin-walled parts, the machining path and the change of the tool axis vector will affect the surface quality of the workpiece and the machining efficiency. The machined surface was discretized into point cloud data, and the surface was fitted. Based on the constraints of mirror milling, the tool location points, and machining paths were generated first. Then the tool location points in the space were projected onto the parameter plane to fit the spline curve. What's more, the position of the corresponding point on the fitting surface was obtained from the tool position point after fitting on the parameter plane and obtaining the tool axis vector. After obtaining the optimized tool position data, the tool axis vector was optimized based on kinematic constraints, precisely, the machine tool rotation axis needs to satisfy the constraints of the maximum angular velocity, maximum angular acceleration, and maximum angular jerk. Therefore, in the process of machining, due to the problems of angular velocity, angular acceleration, and angular jerk at certain tool positions exceeding the limit, feedrate for CNC machines was optimized first. Furthermore, the optimization target was established based on the minimum sum of the motion fluctuations of the rotary axis and the machining time. After that, the optimized machining path and tool axis vector were simulated and tested. Finally, the simulation and experimental results were determined through analysis, which proved the feasibility of the optimized model proposed in this paper. At the same time, the experimental measurement results also showed that the optimized machining path had been significantly improved in both quality and efficiency.

End-supporter path scheduling for robot-assisted asymmetrical support machining of thin-walled parts with non-equal thickness and closed section

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Vacuum preloading hydrostatic support technology for mirror milling of thin-walled parts

“…Guo et al [17] proposed a synchronization accuracy compensation algorithm for the problem that the relative position and direction errors of the milling cutter and the support head seriously affect the machining accuracy of the workpiece during the mirror milling process of thin-walled parts. Qian et al [18]optimized the tool axis vector by an iterative algorithm, which led to a significant improvement in machining quality and machining efficiency. Guo et al [19] proposed an automatic profile tracking method that adaptively samples the deformed surface and reconstructs the surface model.…”