Fault-Tolerant Attitude Control for Rigid Spacecraft Without Angular Velocity Measurements

Area of Science:

• Aerospace Engineering
• Control Systems Engineering
• Robotics

Background:

• Spacecraft attitude control is critical for mission success.
• System uncertainties, external disturbances, and actuator faults pose significant challenges.
• Unavailable angular velocity measurements complicate attitude control design.

Purpose of the Study:

• To develop a fault-tolerant control scheme for rigid spacecraft attitude control.
• To address challenges posed by external disturbances, system uncertainties, and actuator faults.
• To overcome the lack of angular velocity measurements.

Main Methods:

• A super-twisting sliding mode observer was designed to estimate angular velocity in finite time.
• An adaptive fault-tolerant controller utilizing neural networks was developed.
• Simulation analysis was performed to validate the control scheme's effectiveness.

Main Results:

• The observer accurately estimated angular velocity despite unavailable measurements.
• The adaptive controller successfully compensated for system uncertainties and actuator faults.
• Simulations demonstrated exponential convergence of attitude orientations to desired values.

Conclusions:

• The proposed fault-tolerant control scheme effectively manages spacecraft attitude under challenging conditions.
• The integration of a super-twisting observer and neural network controller offers a robust solution.
• The method ensures reliable spacecraft attitude stabilization even with actuator faults and missing sensor data.