Control of cooperative manipulators with passive joints

The problem of the control of cooperative manipulators with passive joints and are rigidly connected to a solid object is addressed in this paper. Passive joints can appear due to free-swinging joint failures or can be an intrinsic characteristic of the robots. A hybrid control of motion and squeeze force is proposed. For this purpose, a Jacobian matrix relating velocities in the actuated joints and load velocity is obtained based on the kinematic constraints of the cooperative system. Results of the control system applied in simulations and in real robots are presented.