Optimization of Spacecraft Thrusters Configuration Under Fault Diagnosability and Recoverability Constraints

Abstract

This paper investigates the problem of optimal placement (position and orientation) of spacecraft thrusters, under fault diagnosability and fault recoverability constraints. Avionics equipment contamination and plume impingement are also considered. The goal is to find the thrusters configuration with the minimal number of thrusters required for a given spacecraft architecture, so that it is guaranteed that it is possible to equip the control unit with a model-based fault diagnosis and fault-tolerant control solution, able to accommodate any single thruster's fault. This includes total loss of controllability of the faulty thruster. The proposed solution is a model-based solution in the sense that it is based on the spacecraft attitude and translational dynamics. With the help of the zonotope concept and its so-called H-representation, it is shown that this problem can be formulated as a nonlinear constrained optimization problem, which can be solved efficiently using hybrid optimization techniques. The proposed solution is assessed on a generic spacecraft architecture that performs a proximity maneuver.