Adaptive Hybrid Compensation Control of Inertia Uncertainty and Disturbance for Variable Structure Hypersonic Vehicle

Abstract

This paper presents an adaptive hybrid compensation scheme for disturbances and uncertain inertia parameters of variable-structure hypersonic flight vehicles (HFV). A nominal nonlinear dynamic inverse (NDI) controller with variable-structure harmonic functions guarantees that the system outputs precisely follow the reference commands for a longitudinal HFV model with modelling errors. In the case of inertia uncertainty, a multi-learning law-adaptive NDI controller is proposed to directly compensate for its influence on the tracking performance, which makes the variable-structure HFV robust to inertia uncertainty and reduces the high vibration of velocity and attitude angles. Subsequently, an improved adaptive variable structure NDI controller with a sliding-mode disturbance observer is designed to actively compensate for sea-skimming disturbances and continuously ensure anti-disturbance flight quality. Finally, the active-passive hybrid adaptive control algorithms compensate for the inertia uncertainty and disturbance of the variable-structure HFV. The proposed method’s efficacy was verified through a semi-physical system simulation, while Lyapunov functions demonstrated the system stability.

Keywords

• Hybrid compensation
• hypersonic flight vehicle
• disturbance observer
• dynamic inverse