Cooperative motion control of multimanipulator based on workspace disturbance observer with variable compliance gain

This paper proposes a cooperative motion control strategy of multimanipulator based on workspace disturbance observer with variable compliance gain. The workspace disturbance observer as an acceleration controller provides a simple, robust and flexible controller structure and computation while the addition of variable compliance gain will maintain the performance of the system in free motion as well as in contact conditions. The motion trajectory control of the cooperative control is realized using an impedance control approach enhanced by a variable compliance gain. This compliance gain is considered as a reflexive response which plays an important role in adjusting the stiffness of the cooperative system as a function of the interaction force. The experimental results show that the use of variable compliance gain has advantages over that of conventional impedance control approach such as it does not no longer require a switching mechanism to set the system's compliance corresponding to the object motion condition.