Disturbance observer-based L1 robust tracking control for hypersonic vehicles with T-S disturbance modeling

Yang Yi,Lubing Xu,Xiangxiang Fan,Hong Shen

doi:10.1177/1729881416671117

Abstract

This article concerns a disturbance observer-based L1 robust anti-disturbance tracking algorithm for the longitudinal models of hypersonic flight vehicles with different kinds of unknown disturbances. On one hand, by applying T-S fuzzy models to represent those modeled disturbances, a disturbance observer relying on T-S disturbance models can be constructed to track the dynamics of exogenous disturbances. On the other hand, L1 index is introduced to analyze the attenuation performance of disturbance for those unmodeled disturbances. By utilizing the existing convex optimization algorithm, a disturbance observer-based proportional-integral-controlled input is proposed such that the stability of hypersonic flight vehicles can be ensured and the tracking error for velocity and altitude in hypersonic flight vehicle models can converge to equilibrium point. Furthermore, the satisfactory disturbance rejection and attenuation with L1 index can be obtained simultaneously. Simulation results on hypersonic flight vehicle models can reflect the feasibility and effectiveness of the proposed control algorithm.

Highlights

The research of hypersonic flight vehicle (HFV) has received considerable attention with great practical value in civil and military applications
We have studied an effective anti-disturbance tracking control scheme for the longitudinal dynamics of a generic HFV system
A DOB PI-type composite control input has been designed based on HFV models in order to realize those control requirements, including dynamical tracking, stability of controlled systems, L1 disturbance attenuation, and disturbance compensation performance

Summary

Introduction

The research of hypersonic flight vehicle (HFV) has received considerable attention with great practical value in civil and military applications (see Fidan et al.[1] and Parker et al.[2]). Some successful DOB anti-disturbance results have been developed to compensate those complex exogenous disturbances existed in HFV models.[16,17,18,19] Using typical T-S fuzzy models, a DOB-mixed H2=H 1 robust fuzzy tracking control method was designed by Wu et al.[17] In the study by Sun et al.,[18] a nonlinear integral sliding mode DOBC was proposed to implement dynamic tracking of velocity and altitude for an HV in finite time. Yang et al.[19] proposed an effective nonlinear DOBC method and solved the robust control problem for a generic air-breathing hypersonic vehicle under the framework of mismatched disturbances In these existed results, the unknown disturbances are usually assumed to be represented by those simple linear models. A nonlinear DO based on T-S disturbance model (7) is applied to estimate unknown disturbances d1ðtÞ, described as d^1ðtÞ

It is KPxðtÞ þ KI

À1:42 Ã 10À13

Conclusion