Optimal Drilling Sequences for Rectangular Hole Matrices Using Modified Shuffled Frog Leaping Algorithm

Several industrial products, including engine blocks, moulds, automotive parts, dies, etc., require many holes to be machined into them. Similarly, applications like processing separators in the food industry, printed circuit boards, drum and trammel screens, boilerplates, etc., also contain a large matrix of holes. Many machining operations, such as drilling, tapping, and reaming, are needed to achieve the required hole diameters, which various operational sequences can produce. One of the biggest hassles with hole-making operations is optimizing the sequence of operations to achieve minimal tool travel time. This is essential in reducing the overall processing costs associated with hole-making operations. The present work attempts to minimize the total tool travel time for hole-drilling operations by employing a relatively new nature-inspired optimization algorithm - the modified shuffled frog leaping algorithm (SFLA). The modifications in SFLA are introduced using three positive parameters to broaden its search capacity. This paper considers three case studies of a rectangular matrix of holes to explain the proposed procedure. The outcomes of the optimization using modified SFLA are compared to those obtained using a genetic algorithm and the ant colony algorithm. Additionally, a higher dimensional problem of a 20x20 rectangular matrix of holes is considered in this work.