Open AccessObserver‐based robust adaptive T2 fuzzy tracking control for flexible air‐breathing hypersonic vehicles
Author(s) -
Liu Yifan,
Pu Zhiqiang,
Yi Jianqiang
Publication year - 2018
Publication title -
iet control theory and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.059
H-Index - 108
eISSN - 1751-8652
pISSN - 1751-8644
DOI - 10.1049/iet-cta.2017.1198
Subject(s) - control theory (sociology) , backstepping , observer (physics) , parametric statistics , state observer , fuzzy logic , adaptive control , fuzzy control system , computer science , control engineering , mathematics , engineering , control (management) , nonlinear system , artificial intelligence , physics , statistics , quantum mechanics
This study presents an observer‐based robust adaptive type‐2 (T2) fuzzy tracking control scheme for the longitudinal dynamics of flexible air‐breathing hypersonic vehicles. The control scheme is composed of three parts, namely an uncertain dynamics approximator, a reduced‐order adaptive state observer, and command filter‐based backstepping altitude and velocity controllers. First, the approximator is implemented by utilising interval T2 fuzzy logic systems for approximating unknown vehicle dynamics in the control scheme. Then, the reduced‐order adaptive state observer is designed by the combination of the approximator and output state feedback techniques, which guarantee the estimation of unmeasurable states as well as uncertain dynamics identification. By using the linear matrix inequalities technique, a new condition for obtaining the gains of the state observer is presented. Next, on the basis of the designed approximator and state observer, the altitude and velocity tracking controllers are constructed by command‐filtered backstepping control approach which avoids the explosion of complexity in conventional backstepping design. Thorough stability analysis of the closed‐loop systems is conducted. Nominal and comparison simulation studies considering parametric uncertainty, incomplete state measurement, and measurement noises are carried out, illustrating the effectiveness of the proposed control scheme.