The Composite Design of H∞-ERL Sliding-Mode Controller

• Main Authors: Zhi-HaoChen, 陳志豪
• Other Authors: Cheng-Neng Hwang
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/39216354373753420521

碩士 === 國立成功大學 === 系統及船舶機電工程學系 === 102 === In a multi-input multi-output nonlinear system, because the system subjects to the impacts of external disturbances and parametric uncertainties, its output response may not be able to satisfy the desired specification or even may make the system unstable. The H∞-ERL sliding mode controller proposed in this thesis is motivated to solve these problems. This controller utilizes the concept of sliding mode controller with ERL (Exponential Reaching Law) as its major framework, and then uses Lyapunov stability theorem to ensure the closed-loop stability when the system encounters prescribed external disturbances and parametric uncertainties. For optimal selection of the adjustable parameters in the proposed sliding mode control with ERL, the H_∞ control methodology and the lag-lead compensator are formulated together in the proposed control scheme to find optimal control gains, which are used to minimize the ill-effect of external disturbances and plant parametric uncertainties on the controlled output. The closed-loop poles of the augmented system are then placed on the specified region to match the desired performance. The Popov criterion is then applied to handle of the uncanceled dynamics caused by the unmodeled uncertainties so that the system robustness can be guaranteed. Finally, a robot manipulator and a ROV are controlled and simulated respectively by the proposed controller. The simulation results reveal that the proposed control law is robust to plant uncertainties and disturbances while the desired specification assigned by users is matched.