Verification & Validation of a Satellite Fault Detection and Isolation Scheme Based on Sliding-Mode Observers

In this article, the verification and validation (V&V) of a fault detection and isolation scheme based on sliding mode observer residual evaluators and threshold-based residual analysis of gyro and thruster faults for the Mars EXpress (MEX) satellite is presented. The results were part of a European Space Agency project with the goal of examining the potential applicability of modern model-based FDI techniques for on-board satellite deployment. The V&V campaign, consisting of firstly a set of specified fault simulations and secondly a Monte Carlo campaign, has been performed using an industrial-level functional engineering simulator developed around a high-fidelity model of the MEX satellite operating during the Sun Acquisition Mode (SAM), which includes up to 6 different controller mode changes. The results show the good performance and robustness of the FDI scheme throughout the SAM phase.