Generating Multiaxis Tool Paths for Die and Mold Making with Evolutionary Algorithms

Abstract

Defining tool paths for multiaxis milling is a difficult task that requires knowledge about the process and the behavior of the machine tool. Because of the high risks of multiaxis movements within a real machine, the resulting paths are safe but normally sub-optimal. This article introduces a new method to obtain tool paths, which are free of collisions and optimal in consideration, the machine and its kinematics. The proposed method combines evolutionary algorithms and a newly developed efficient multiaxis milling simulation. The evolutionary algorithm uses multiple criteria for the optimization of a tool path. These criteria are minimized axial movement of the machine, minimal cutting forces and the exclusion of collisions between the workpiece and the non-cutting parts of the cutting tool. The approach uses multi-objective algorithms because minimal or no movement of a machine axis can lead to high cutting forces or multiple collisions. Along with the evolutionary algorithm, this article introduces a simulation for multiple axis milling. This simulation is able to compute the fitness of the given tool paths by considering the engagement condition and collision situation of a cutting tool.