Abstract
The authors present an assembly motion planner for two polyhedral objects. The retraction subspace is defined by the configuration of these objects where they are in a particular contact such that the motion has zero or one degree of freedom. The planner gives assembly trajectories defined by a set of contacts. Each portion of the generated path is associated to a contact state with constant qualitative properties. A contact graph is associated to the boundary structure of the configuration space. The planner includes an incremental method to build the graph and to find a path. Some heuristics are defined to select locally the best arcs to compute. A first version of the planner has been implemented. Simulation results of an assembly trajectory planned by the system are presented.<>