Distributed Modular and Reconfigurable Robot Control with Torque Sensing

A major technical challenge in controlling modular and reconfigurable robots is associated with the kinematics and dynamic model uncertainties caused by reconfiguration. In parallel, conventional model uncertainties such as uncompensated joint friction still persist. This paper presents a modular distributed control technique for modular and reconfigurable robots that can instantly adapt to robot reconfigurations. Under the proposed control method based on joint torque sensing, a modular and reconfigurable robot is stabilized joint by joint, and modules can be added or removed without the need to adjust control parameters of the other modules of the robot. Model uncertainties associated with links and payload are compensated using joint torque sensor measurement, and the remaining model uncertainties including unmodeled dynamic coupling effect and joint friction are compensated by a decomposition based robust controller. This approach allows stable and precise distributed control of modular and reconfigurable robot. Simulations were conducted to investigate the proposed approach, and the results have confirmed its effectiveness