Adaptive terminal sliding mode control for hypersonic flight vehicles with strictly lower convex function based...

Area of Science:

• Aerospace Engineering
• Control Systems Theory
• Nonlinear Dynamics

Background:

• Hypersonic flight vehicles (HFV) face significant challenges in altitude and velocity control due to parametric uncertainties and external disturbances.
• Existing control strategies often struggle with robust performance in the presence of these complex dynamics.

Purpose of the Study:

• To develop a novel control scheme for the longitudinal dynamics of HFV that enhances robustness and disturbance rejection.
• To address the issues of parametric uncertainties and external disturbances in HFV trajectory tracking.

Main Methods:

• A strictly lower convex function based nonlinear disturbance observer (SDOB) was designed to estimate and compensate for disturbances.
• An adaptive terminal sliding mode controller (ATSMC) was integrated with the SDOB, forming the SDOB-ATSMC.
• Lyapunov function method was employed to analyze the stability of the proposed control scheme.

Main Results:

• The proposed SDOB-ATSMC effectively estimates and compensates for disturbances, improving anti-interference capability.
• The controller demonstrated superior robustness and disturbance rejection performance compared to conventional approaches.
• Adaptive laws were incorporated to mitigate the differential explosion problem inherent in such control systems.

Conclusions:

• The SDOB-ATSMC offers a significant advancement in HFV control, providing enhanced robustness and disturbance rejection.
• The integration of a novel SDOB and adaptive laws addresses key challenges in hypersonic flight control.
• Simulation results validate the effectiveness and superior performance of the proposed control strategy.