Design of dynamic control of two cooperating robot arms: Closed chain formulation

Abstract

In this paper the dynamic equation describing two cooperating robot arms which simultaneously are working on the same object is established by considering the whole system as a closed kinematic chain. This formulation has the advantage of automatically handling the coordination and load distribution between the robot arms through the dynamic equation. It can also be generalized to a multi-robot arm system. The control problem is solved as a design problem for a linear system by first applying a nonlinear feedback and nonlinear coordinate transformation to linearize the nonlinear dynamic equation, and then employing the linear optimal control theory to design a robust controller in the task space. This new dynamic control method establishes a direct control response to task space commands facilitating dynamics based task encoding in robotics.