Combined Motion Control of the Platform and the Manipulator of WorkPartner

A common problem one has to face when developing mobile manipulators is the coordination between the movement of one or more manipulators and the locomotion of the mobile platform. This paper introduces a solution using a reactive look-back style approach instead of the widely used more deliberative methods. Additional degrees of freedom provided e.g. by an upper body mounted on the platform or by legs as well as the typical nonholonomic characteristics are taken into consideration. Further means to tune the way the platform adaptation is performed to the restrictions imposed by the given task are provided. The design is implemented on the hybrid robot WorkPartner. It is a lightweight mobile service robot designed to work interactively with humans in outdoor environment. Some initial experiments to verify the feasibility of the architecture are presented.