HYBRID ADAPTIVE FUZZY SLIDING MODE CONTROLLER FOR UNCERTAIN NONLINEAR SYSTEM

• Main Authors: Lei-Huan Kung, 龔磊桓
• Other Authors: Prof. Chung-Chun Kung
• Format: Others
• Language: en_US
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/25343827551574763921

碩士 === 大同大學 === 電機工程研究所 === 90 === In this thesis, a hybrid adaptive fuzzy sliding mode controller for uncertain nonlinear systems is proposed to attenuate the effects caused by unmodeled dynamics, disturbances and approximate errors. Because of the advantages of fuzzy logic systems, which can uniformly approximate nonlinear continuous functions to arbitrary accuracy, adaptive fuzzy control theory is then employed to derive the update laws for approximating the uncertain nonlinear functions of the dynamical system. Furthermore, the hybrid adaptive (HA) law design technique and the sliding mode control method are incorporated into the adaptive fuzzy control scheme so that the derived controller is robust with respect to unmodeled dynamics, disturbances and approximate errors. Compared with conventional adaptive law, the HA law utilizes two types of errors in the adaptive system, the tracking error and modeling error. Performance analysis using a Lyapunov synthesis approach proves the superiority of the HA law over the direct adaptive (DA) method in terms of faster and improved tracking and parameter convergence. Then, we apply the hybrid adaptive fuzzy sliding controller to control the inverted pendulum system. The simulation results demonstrate and confirm the theoretical results.