Reliable Nonlinear Control via Combining SDRE and ISMC Approaches

• Main Author: 林立岡
• Other Authors: Liang, Yew-Wen
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/61213249257952563116

碩士 === 國立交通大學 === 電控工程研究所 === 98 === In this thesis, we investigate the nonlinear reliable control issues via the state-dependent Riccati equation (SDRE) scheme with application to the attitude control of a satellite. Owing to incorporating with the integral sliding mode control (ISMC) design, both the robustness and the reliability performances are greatly improved. However, it is known that the conventional SDRE scheme has to symbolically factorize the drift term in the form of f(x)=A(x)x, and then using this A(x) to check system's stabilizability and observability symbolically at every nonzero state for ensuring the solvability of an associated SDRE. These checking conditions are in general not easy to implement when the system dynamics is complicated, and there is no guideline provided for performing the factorization. As a result, this study also presents an alternative approach of factorization, which only requires the information of the system dynamics at every state and guarantees the existence of a unique positive definite solution of the associated Riccati equation when a mild condition is satisfied. It is shown that the alternative approach always works if the conventional SDRE approach adopting any specific factorization for f(x) is successfully operated. An illustrative example is also given to demonstrate the benefits of the alternative approach of factorization.