This paper presents a method for coordinating the motion of multiple manipulators that share a common workspace. The approach employs independent motion controllers for each manipulator coupled by way of common configuration space constraints-each robot is represented as a constraint in the other configuration spaces. The harmonic function-based controller for each robot guarantees collision-free motion up to dynamic limits. Heuristic constraints are introduced to compensate for the lack of global information in the resulting distributed controller. The relationship between the distributed controller and the task planner is discussed and results of an experimental implementation are presented.

Control based on artificial potentials results in, bounded-torque controllers. The authors extend this notion by devising energy-reference controllers that use harmonic potentials to produce collision-free kinodynamic behavior. In addition, the phase space structure of a manipulator controlled by an artificial potential "copies" the critical point structure of that potential. This result is used in conjunction with harmonic potentials to generate and control convergent and repetitive motions for a manipulator.