Finite-time Extended State Observer based fault tolerant output feedback control for attitude stabilization

Area of Science:

• Aerospace Engineering
• Control Systems Theory
• Robotics

Background:

• Spacecraft attitude control is critical for mission success.
• Existing systems struggle with actuator failures, external disturbances, and lack of angular velocity data.
• Robust control is needed for reliable spacecraft operation.

Purpose of the Study:

• To develop a finite-time fault-tolerant attitude stabilization control system for rigid spacecraft.
• To address challenges posed by external disturbances and actuator failures without angular velocity measurements.
• To ensure finite-time stability and performance under uncertain conditions.

Main Methods:

• A novel continuous finite-time Extended State Observer (ESO) was designed to simultaneously estimate attitude angular velocity and system failures.
• A continuous finite-time attitude controller was developed using nonsingular terminal sliding mode control and super-twisting methods.
• Finite-time stability and chattering-free control were achieved through the integration of these advanced techniques.

Main Results:

• The proposed ESO achieved finite-time uniformly ultimately bounded stability for attitude angular velocity and observation errors.
• The developed controller ensured finite-time stability for the closed-loop attitude control system.
• Numerical simulations validated the effectiveness and superior performance of the finite-time observer and controller.

Conclusions:

• The proposed finite-time fault-tolerant control strategy significantly enhances spacecraft attitude stabilization.
• The integration of a finite-time ESO and advanced sliding mode control offers a robust solution for complex operational scenarios.
• The chattering-free, continuous control scheme demonstrates practical applicability for real-world spacecraft systems.