H-infinity control for a class of singular systems via disturbance observer based control method

A new H-infinity control method for singular systems via disturbance observer based control (DOBC) is proposed. External disturbance widely exist in singular systems, to reduce their effect on system performance, a disturbance observer is constructed for singular systems to estimate disturbance and parameters perturbation within the system, the convergence of disturbance observer is guaranteed by singular system admissibility principle. Then, the robust controller based on the disturbance observer is proposed, the stability and robust capability of the system is guaranteed by Lyapunov stability theory, the condition of closed loop stable system to have robust capability is derived by designed index function. Compared with the traditional robust method, the DOBC method is less conservative. Finally, an example is given to show the correctness and effectiveness of proposed method. © 2017, Editorial Department of Control Theory & Applications South China University of Technology. All right reserved.