Kinematics of mobile manipulators and implications for design

A systematic, unified kinematic analysis for manipulator arms mounted to mobile platforms is presented. The differential kinematics for the composite system is used, along with an extended definition of manipulability, to generate a design tool for this class of systems. An example is presented in which a 3 DOF anthropomorphic manipulator is mounted on a platform powered by two independent drive wheels. Scaled manipulability ellipses are used to visualize the effect of manipulator mounting position on the overall mobility of the system. Given information about the intended tasks of the mobile manipulator, conclusions may be drawn as to the most appropriate mounting site. For the tasks which motivated this research, automated highway construction and maintenance, it was concluded that the manipulator base should be near the axles of the drive wheels and far from the centerline of the platform. (C) 2000 John Wiley & Sons, Inc.