Position and Force Control with Mass Estimation for Cooperative Systems

The cooperative manipulation of an object by two or more robotic arms requires controlling both the object's movement and the forces exerted by the manipulators. In terms of kinematics and static, the chosen approach is based on the so-called symmetric formulation. A control algorithm using a modified hybrid computed-torque method based on the Principle of Orthogonalization is designed. In addition, the mass of the object is estimated by calculating the force applied by each end-effector to hold the object. The proposed method is a natural extension of an adaptive control scheme previously reported for geometrically restricted manipulators. The stability test is developed using Lyapunov's theory. Experimental results are presented.