Automatic reteach of manipulators for manufacturing multiple product lines

A method for automatically reteaching robot tasks is described. Reteaching is necessary in many advanced applications of manipulators. The method allows tooling fixtures to be moved without requiring excessive manual reteach operations. This enables one manipulator to economically assemble multiple products even though the fixtures for only a single product will fit within the manipulator workspace at a time. Contributions are made in dealing with problems associated with reteach when the original points are near a singularity. Problems with points near singularities include excessive joint motion and obstacle avoidance. These problems are solved by introducing tolerances on joint motion and pose error. The method is successfully implemented on two industrial manipulators. A gear assembly is taught via a pendant, the tooling fixture moved and the assembly program retaught automatically without intervention