A comparison of linear rank and tournament for parent selection in a genetic algorithm solving a dynamic travelling salesman problem

Abstract

We compare the two parent selection methods “linear rank” and “tournament” in a Genetic Algorithm applied to a dynamic Travelling Salesman Problem (TSP). The inherent dynamics of the problem is considered by temporarily doubling the costs between two randomly selected cities. In our experiments we take into account tournament selection with tournament sizes of 3, 5, and 10. A larger tournament size results in as good a performance as with linear rank selection in a small-scale dynamic TSP, whereas smaller tournament sizes better preserve the diversity of the population and avoid getting stuck in local optima. However, the assumption that tournament is superior to linear rank on a dynamic TSP could neither be confirmed nor falsified in the applied testcases.