Observer-enhanced sliding mode control for fixed-wing aircraft automatic carrier landing

Area of Science:

• Aerospace Engineering
• Control Systems Theory
• Robotics

Background:

• Direct Lift Control (DLC) in automatic carrier landings decouples attitude and trajectory control.
• Existing DLC methods exhibit slow error convergence and poor robustness against unknown time-varying disturbances.

Purpose of the Study:

• To propose an observer-enhanced sliding mode control scheme for automatic carrier landing.
• To improve tracking error convergence speed and enhance robustness against external disturbances.

Main Methods:

• Designed a non-singular fast integral terminal sliding mode control (NFITSMC) for finite-time error convergence.
• Embedded the super-twisting algorithm into an extended state observer, creating a super-twisting extended state observer (STESO) for real-time disturbance estimation.
• Applied the proposed control algorithm to an automatic carrier landing system.

Main Results:

• The NFITSMC ensures finite-time convergence of the tracking error.
• The STESO effectively estimates and compensates for unknown time-varying disturbances.
• Lyapunov stability analysis and simulations confirm fast error convergence and strong robustness.

Conclusions:

• The proposed observer-enhanced sliding mode control scheme achieves desired performance in automatic carrier landings.
• The system demonstrates fast error convergence and robust performance against complex time-varying disturbances within finite time.