Tool Position Trajectory Optimization Of Non-developable Ruled Surface With Side Milling Based On Intelligent Algorithms

Impeller parts have complex geometries that require five-axis CNC machining techniques for machining.For the machining of non-developable ruled surface parts,end milling or side milling is generally used.The end milling method is point contact machining,which has the disadvantages of low processing efficiency and poor roughness of parts.The side milling method is a line contact machining,so it effectively avoids these shortcomings,but the optimization of the tool position trajectory in the side milling process increases the difficulty.In order to improve the machining accuracy,the side milling machining tool position optimization algorithm needs to be deeply studied.Therefore,this paper mainly studies the following aspects:(1)Non-developable ruled surface modeling technology: The blade baseline data points are interpolated into B-spline form by NURBS interpolation technique,and the blade baseline B-spline control points are calculated.Corresponding control points obtained on the two baselines are sequentially connected to obtain the blade surface.By calculating the offset distance of the blade surface to obtain the equidistant surface of the blade surface,the blade model can be obtained.Finally,the blade surface smoothness is verified.(2)Tool position optimization based on the close method: Based on the basic algorithm of two-point offset method,the machining accuracy of non-expandable ruled surface parts is improved.This paper proposes a calculation method for finding the optimal tool axis vector group by fixed-point rotation,and further optimization by close method.The simulation was carried out by comparison analysis of machining errors.The results show that the local error of single-slice position is significantly improved.(3)Tool location optimization based on GA-NOA optimization algorithm: This paper proposes an optimization method based on genetic algorithm(GA)and nonlinear programming(NOA)hybrid algorithm.The simulation results show that the optimization process of the overall tool position is simple,the precision of the optimization result is high,and the tool envelope error formed by the optimized pose is small.(4)VERICUT-based virtual simulation processing: After the tool position file is post-processed,the DMU50-SIEMENS840 D virtual simulation processing system of DMG Company is built on the VERICUT platform,and the blade model is simulated and processed.The tool position files of different algorithms are compared with the blade model for overcutting or undercutting data influences.The correctness of the algorithm proposed in this paper is verified.