Two new heuristic models are developed for motion planning of point robots in known environments. The first model is a combination of an improved particle swarm optimization (PSO) algorithm used as a global planner and the probabilistic roadmap (PRM) method acting as a local obstacle avoidance planner. For the PSO component

new improvements are proposed in initial particle generation

the weighting mechanism

and position- and velocity-updating processes. Moreover

two objective functions which aim to minimize the path length and oscillations

govern the robot’s movements towards its goal. The PSO and PRM components are further intertwined by incorporating the best PSO particles into the randomly generated PRM. The second model combines a genetic algorithm component with the PRM method. In this model

new specific selection

mutation

and crossover operators are designed to evolve the population of discrete particles located in continuous space. Thorough comparisons of the developed models with each other

and against the standard PRM method

show the advantages of the PSO method.