Robust adaptive controller design for underactuated mechanical systems

Due to lack of enough control inputs for system degrees of freedom, the underactuated system is always a challenging problem in the field of control application. For this reason, a growing interest is arising about the design of automatic control systems for underactuated system. In this paper, to achieve the robustness of the system, a new coupling control scheme is applied to obtain a globally asymptotically stable resat parameters for a class of underactuated mechanic system. By utilizing a Lyapunov-based stability analysis, we can achieve asymptotic tracking of desired reference signal which is subject to both underactuation and parametric uncertainties. To demonstrate the effectiveness of the proposed controller, results are applied to the Furuta pendulum system and a planar flexible joint robot.