Optimization of Spacecraft Thrusters Configuration Under Fault Diagnosability and Recoverability Constraints

This article 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 configuration with the least number of thrusters required for a given spacecraft architecture, so that equipping the control unit with a model-based fault DX and fault-tolerant control solution, able to accommodate any single thruster's fault can be guaranteed. 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 $\mathcal H$-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.