Motion planning refers to the ability of a system to automatically plan its motions. It is considered central to the development of autonomous robots. In the last decade, much research effort was done on the application of probabilistic roadmaps methods (PRM) for different types of problems (Kavraki et al., 1996; Svestka & Overmars, 1997; Bohlin & Kavraki, 2000; Sánchez & Latombe, 2002). There ...