Robust adaptive control for spacecraft final proximity maneuvers with safety constraint and input quantization.

Area of Science:

• Aerospace Engineering
• Control Systems
• Robotics

Background:

• Spacecraft proximity operations require precise control to ensure safety and mission success.
• Uncertainties in system parameters and external disturbances pose significant challenges to robust control.
• Collision avoidance is a critical safety constraint during rendezvous and docking maneuvers.

Purpose of the Study:

• To develop a robust quantized proximity control strategy for spacecraft.
• To address challenges posed by uncertain system parameters, external disturbances, and safety constraints.
• To ensure collision avoidance and guarantee stable system performance during proximity operations.

Main Methods:

• A nonconvex forbidden zone was defined around the target spacecraft.
• A novel repulsive potential function was designed to enforce collision avoidance.
• An adaptive safety controller was developed by integrating artificial potential functions with sliding mode control.
• Lyapunov framework was used for rigorous stability analysis.

Main Results:

• The proposed controller guarantees ultimate boundedness of all system signals.
• A real-time safety trajectory was successfully generated for the chaser spacecraft.
• Simulation results validated the effectiveness and robustness of the developed control strategy.

Conclusions:

• The adaptive safety controller effectively manages robust quantized proximity control for spacecraft.
• The controller ensures collision avoidance and system stability under uncertain conditions.
• The methodology provides a reliable approach for safe spacecraft rendezvous and docking operations.