A composite control design for suppressing mutual interference of interconnected systems

This paper presents a new disturbance decoupling and rejection method for a multi-connected system, and introduces the composite controller based on disturbance compensator and the state feedback control. While in action, a developed dynamic model of a 2DOF robot system was studied and analyzed. The movement of one joint affects the motion of the other, which brings the control performance down. In order to compensate and keep the desired control performances, we designed a double active control system which can effectively reject the direct mutual disturbances. These disturbances are considered the known uncertainties and can be experimentally determined. The designed control system consists of two controllers, the first one is an inner loop controller and works as a disturbance compensator that attenuates the known disturbances. And the second one, on the other hand, is an outer loop controller, which was designed based on H ∞ control theory to maintain the system stability and a robust control performance under the unpredictable uncertainties. In this paper, simulation and experiments were conducted using a PID controller, and the designed control system, as well as changing the payload attached to the end-effector in order to test the control performance. Finally, the results show that the proposed system suppresses and rejects the mutual disturbances effectively with enhanced tracking performances.