Two-layer Fault Detection for Incremental Flight Control of Fixed-wing UAV

The ability of the UAV to adapt to possible failures or changes in flight dynamics is crucial for its resilience. The paper proposes a two-layer fault detection procedure augmenting Incremental Controller (IC) designed for a fixed-wing UAV. IC benefits from recent advantages of the sensing technologies and uses angular accelerations and current control deflections to reduce the dependency on aircraft model. Nevertheless, control effectiveness is still required for its implementation. The elaborated two-layer fault detection scheme is capable to detect and localize possible failures and provide the IC with on-line estimations of control effectiveness. At the first layer, the system performs monitoring of possible failures. If a problem in one of the control direction is detected the algorithm initiates the second-layer identification determining the individual effectiveness of each control surface involved in this control direction. The effectiveness of the proposed fault detection technique is demonstrated with simulation of stuck in position and hardover of the aileron of a fixed-wing UAV.