A Torque Controlled Approach for Virtual Remote Centre of Motion Implementation

In this paper, we propose a novel torque controller for the implementation virtual remote center of motion. The controller allows the system to implement the required behavior and guarantees the satisfaction of the remote center of motion constraint. Exploiting the Udwadia-Kalaba equation for constrained dynamic systems, the controller is synthesized considering the dynamic effect the constraint produces on the manipulator, achieving more effective control with respect to kinematic strategies, and allowing the implementation of compliance behaviors. Simulations and experimental validation with a KUKA LWR 4+ with 7 degrees of freedom has been performed to check the performances of the proposed controller. Results show the effectiveness of the proposed controller with different control action, and the capability to interact with the environment by implementing compliant motion control.