Layout Optimization of Square Parts Based on BL-IGA Algorithm

Square products are a kind of products formed by assembling several layout accessories after plane processing with the plate as the main original piece. In order to improve the utilization rate of plate, this paper proposes a square layout optimization model based on BL-IGA algorithm. First, the data set is processed and analyzed; Secondly, a mixed integer programming model is established with the decision variables as the product project portfolio sequence and the objective function as the plate utilization maximization After that, the BL algorithm and the improved genetic algorithm (BL-IGA) are used to solve the above model, the chromosome is encoded into the item sequence, and the BL algorithm is used to arrange the item sequence (rotatable) on the original plank of the specified size under the constraint conditions, until all the items in the chromosome are arranged, and the utilization rate of the generated sheet is used as the individual fitness. In order to solve this problem better, IGA adopts non-repeating integer coding, sequential crossover and reverse mutation. At the same time, the improved crossover probability and mutation probability genetic algorithm makes it have better global search ability and faster convergence speed. Finally, the utilization rate of plate can reach about 70 % by using the square layout optimization model based on BL-IGA algorithm. In addition, with the increase of data size, the change rate of running time of the BL-IGA algorithm generally shows a downward trend, showing a better time complexity.