Motion and Force Control of Multiple Coordinated Redundant Manipulators

In this paper, an approach to motion and force control of multiple coordinated redundant manipulators working in an environment with obstacles is developed in which the extended task space technique is presented for establishing the dynamic equations of the coordinated redundant manipulators using the redundant degrees of freedom. This approach can be used to control the motion of an object held by the redundant manipulators and the internal forces which do not contribute to the motion of the object while avoiding obstacles. Three subsystem error equations are generated, i.e., a position error subsystem, an internal force error subsystem, and a constraint error subsystem. The adaptive law is derived to estimate the unknown parameters of the multiple coordinated redundant manipulators and the object in terms of the three error subsystem equations. The paper shows that the control scheme improves the position and internal force tracking accuracy and avoids collision for a class of systems with uncertain knowledge of the dynamic model.