Guardian Map Approach to Feasible Range of Static Stability Margin of Hypersonic Flight Vehicles with Input Saturation

Hao Lei,Boyi Chen,Yanbin Liu,Yuping Lu

doi:10.1155/2020/8895324

Abstract

Static stability margin is a critical parameter in flight control design. The feasible range of it must cover the uncertainty through the flight. To reasonably identify the feasible range of static stability margin in advance, an approach based on guardian maps is proposed for flight control of hypersonic flight vehicles with input saturation. First, the model of hypersonic flight vehicle (HFV) is established as a parametric plant. Then, flying quality requirements for the closed-loop system are formulated as inequality constraints using guardian maps. Moreover, by using linear matrix inequality, the saturation of elevators is taken into account in the integrated control of attitude control. The prescribed minimum of static stability margin that ensures the flying quality of hypersonic flight vehicles with input saturation is obtained. Furthermore, from the prospective of integrated control, it is shown that the feasible range of static stability margin can be enlarged by changing aerodynamic characteristics. The effectiveness of the proposed approach is validated by numerical simulation.

Highlights

Large flight envelopes [1], unstable longitudinal dynamics with input saturation [2], and environmental uncertainty [3] lead to a great of difficulty in flight control system design of hypersonic flight vehicles (HFV)
An analytical approach for determining the feasible range of static stability margin has been proposed based on guardian maps and linear matrix inequality
The feasible range of static stability margin is characterized by the minimum static stability margin, which is obtained by formulating an optimal problem

Summary

Introduction

Large flight envelopes [1], unstable longitudinal dynamics with input saturation [2], and environmental uncertainty [3] lead to a great of difficulty in flight control system design of hypersonic flight vehicles (HFV). Tracking control for HFV with model uncertainties for prescribed performance is a challenging task [4]. The majority focuses on the adaptive nonlinear approach for non-affine models with mismatched disturbance [7, 8] and large-envelope tracking problem with global stability and prescribed performance [9,10,11]. The global stability can be hardly guaranteed in closed-loop system with input saturation since the longitudinal dynamics is inherently unstable for hypersonic flight [12]. The stability region of a closed-loop system should be confirmed beforehand, and the feasible range in which the closed-loop performance remains must be identified [13]

Objectives

Results

Conclusion