Variable-Structure Near-Space Vehicles with Time-Varying State Constraints Attitude Control Based on Switched...

Area of Science:

• Aerospace Engineering
• Control Systems Theory
• Nonlinear Dynamics

Background:

• Near-space vehicles (NSVs) require robust attitude control systems.
• Time-varying state constraints pose significant challenges in NSV control.
• Switched nonlinear systems are common in modeling complex vehicle dynamics.

Purpose of the Study:

• To develop an attitude control scheme for variable-structure near-space vehicles (VSNSVs).
• To address asymmetric time-varying state constraints in VSNSVs.
• To overcome modeling uncertainties and external disturbances in attitude control.

Main Methods:

• An extended state observer (ESO) with two linear regions to avoid peaking.
• An active disturbance rejection controller (ADRC) using asymmetric time-varying barrier Lyapunov functions (BLFs).
• A modified dynamic surface control (DSC) to mitigate the 'explosion of complexity'.

Main Results:

• The proposed ESO effectively estimates total disturbances without peaking.
• The ADRC ensures full state constraints are satisfied under asymmetric time-varying boundaries.
• Stability analysis confirms all closed-loop system signals remain bounded.
• Numerical simulations validate the proposed control scheme's effectiveness.

Conclusions:

• The developed control strategy effectively manages attitude control for VSNSVs with complex constraints.
• The integration of ESO, BLF-based ADRC, and modified DSC offers a robust solution.
• The findings contribute to enhanced stability and safety in near-space vehicle operations.