Determination of the optimal drill path sequence using bat algorithm and analysis of its optimization performance

Abstract

Generation of circular holes with varying dimensions in diverse parts/products is one of the most common operations in any manufacturing industry. Determination of the optimal drill path sequence is an important problem in hole-drilling operation using CNC machines. This problem's structure is quite analogous to travelling salesman problem and hence, is NP-complete belonging to both NP and NP-hard complexity classes. Due to exponential increase in number of possible solutions when the number of holes to be drilled increases, various evolutionary algorithms are seemed to be the viable choices in solving this type of optimization problem. In this paper, an almost unexplored swarm-based algorithm, in the form of bat algorithm, is applied to determine the optimal path sequences for different layouts consisting of 5 × 5, 7 × 7, 9 × 9 and 11 × 11 matrices of holes, and a 14-hole benchmark model, taking into account machining time, machining cost and non-productive cost of the related drilling operation.