Multi-criteria position and configuration optimization for redundant platform/manipulator systems

An important characteristic of practical mobile manipulators, i.e. manipulators mounted on mobile platforms, is their particular kinematic redundancy created by the addition of the degrees of freedom of the platform to those of the manipulator. This paper is concerned with the resolution of this kinematic redundancy, and in particular with the local optimization of the position and configuration of the system during task commutations when changes occur in both task requirements and task constraints. Optimization criteria for obstacle avoidance, manipulability, least torque norm and maximum actuator torque are first discussed. Emphasis is then placed on optimization methods for problems involving multi-requirements and multicriteria optimization. Sample results of the methods for a system including a three-link manipulator mounted on a mobile platform are presented and discussed