Path Planning for Multi-Joint Manipulator Based on the Decomposition of Configuration Space

The problem of collision-free path planning for six joints manipulator used for nuclear reactor repairing was considered, a new approach based on the decomposition of configuration space was presented in this paper. Since the collision with the environment occurs mainly on the three joints near the proximal joints of manipulator, the six dimensional configuration space was decomposed into two three low dimensional subspaces. Respectively, the discrete configurations were generated in each subspace for the local path searching, then a collision table was set up for the on-line path planning. In order to reduce the size of collision table and avoid the redundant collision checking, in the process of sampling configuration, we check the collision status of these points and avoid the collided configuration points to be generated in the collision table. In order to further improve the reasonability distribution of sampled points, we used the distance information with the obstacle to guide the generation of configurations. The simulation results showed that the approach not only reduced the length of searing path, but also improved the efficient of on-line planning.