“…Among many heuristic algorithms, the swarm intelligence based evolutionary methods are suitable tools for solving planning problems, since they can approximate the optimal solutions by randomly generating initial solution groups and iteratively optimizing the problems of concern. Many research works have been conducted to explore and improve the intelligence based evolutionary algorithms, such as the genetic algorithm [29], particle swarm optimization [29,30], the artificial fish school algorithm [31], the firefly algorithm [32], chicken swarm optimization [33], and the bird swarm algorithm (BSA) [34]. Among these algorithms, BSA can effectively optimize non-convex and non-differentiable optimization problems through simulating the natural behavior of birds [35], and is not subject to local optimal solutions.…”