A Diagnostic Thau Observer for a Class of Unmanned Vehicles

This paper addresses the problem of sensor fault detection for a wide class of Unmanned Vehicles (UVs). First a general model for UVs, based on the dynamics of a 6 Degrees Of Freedom (6-DOF) rigid body, subject to gravity and actuation forces, is presented. This model is shown to satisfy the necessary conditions to the existence of a non-linear observer (Thau) when proper assumptions for the actuation forces are made. The observer can thus be used to generate diagnostic residuals inside a Fault Detection (FD) system. Finally, the proposed approach is customized for sensor fault detection on an unmanned quad-rotor vehicle, and simulation results show the effectiveness of the adopted solution.