Data Mining based mutation function for engineering problems with mixed continuous-discrete design variables

Genetic algorithms are well established for solving engineering optimization problems having both continuous and discrete design variables. In this paper, a mutation function for discrete design variables based on Data Mining is introduced. The M5P Data Mining algorithm is used to build rules for the prediction of the optimization objectives with respect to the discrete design variables. The most promising combinations of discrete design variables are then selected in the mutation function of the genetic algorithm GAME to create children. This approach results in faster convergence and better results for both single and multi-objective problems when compared with a standard mutation scheme of discrete design variables. The optimization of a vehicle space frame showed that a mutation probability between 40% and 60% for the discrete design variables results in the fastest convergence. A multi-objective aerospace conceptual design example showed a substantial improvement in the number of pareto-optimal solutions found after 100 generations.