Process planning optimization of hole-making operations using ant colony algorithm

Abstract

This paper presents a method for the process planning optimization of hole-making operations, where the machining process of a hole consists of several individual operations with different machining tools. The optimization objective is to minimize the total auxiliary time of the machining process, including the airtime and the tool changing time. The machining process of a part is represented as a dynamic directed graph, where each graph node represents a single operation in the hole-making process. The objective of minimizing the total auxiliary time is to find the shortest path of the directed graph, and this objective has a structure similar to the traveling salesman problem. A mathematical model that describes the hole-making problem is proposed based on this graph structure, and an ant colony algorithm is applied to solve the optimization, since the problem is NP-complete. It is demonstrated with examples that the proposed method can significantly reduce the auxiliary time of hole-making process.