Multiple impedance control for object manipulation

Impedance control was formulated originally to impose a desired behavior on a single manipulator interacting with its environment. In this paper, a new algorithm called multiple impedance control (MIC) is proposed for the cooperative manipulation of a common object. The general formulation for the MIC algorithm is developed and it is shown that under the MIC law all cooperating manipulators, and the manipulated object exhibit the same designated impedance behavior. At the same time, the potentiality large object inertia and other forces are taken into account. An estimation procedure for contact force determination is given which results in a good approximation even during an impact. Using an example, the response of the MIC algorithm is compared to that of the object impedance control. It is shown that in the presence of flexibility, the MIC algorithm results in an improved performance