Dynamic-Programming-Based Failure-Tolerant Control for Satellite with Thrusters in 6-DOF Motion

TL;DR

This paper presents a dynamic programming approach for failure-tolerant control of thruster-driven satellites in 6-DOF, optimizing control policies and allocation to handle thruster failures efficiently.

Contribution

It introduces a novel dynamic programming-based control method that adapts to thruster failures and improves fuel efficiency compared to Lyapunov-stable control methods.

Findings

The proposed method maintains control performance during thruster failures.

It achieves more fuel-efficient path tracking than Lyapunov-based control.

Dynamic reconfiguration of control policies enhances fault tolerance.

Abstract

In this paper, a dynamic-programming approach to the coupled translational and rotational control of thruster-driven spacecraft is studied. To reduce the complexity of the problem, dynamic-programming-based optimal policies are calculated using decoupled position and attitude dynamics with generalized forces and torques as controls. A quadratic-programming-based control allocation is then used to map the controls to actuator commands. To control the spacecraft in the event of thruster failure, both the dynamic programming policies and control allocation are reconfigured to cope with the losses in controls. The control allocation parameters are adjusted dynamically to ensure the satellite always approaches the target from the side with two operative thrusters to achieve a stable control. The effectiveness of the proposed dynamic programming control is compared with a Lyapunov-stable control method, which shows that the proposed method is more fuel-efficient in tracking the same path.