Passive Fault-Tolerant Control of Dual-System UAV Transition Flight Under Partial Loss of Propellers

A novel passive fault-tolerant control system for the transition flight of a dual-system unmanned aerial vehicle (UAV) is proposed in this paper. The nominal control synthesis is first conducted without considering the occurrence of actuator fault. Stability evaluation using mu-analysis and performance analysis based on a multi-model approach, by assuming the existence of actuator fault, are subsequently carried out, which suggests the nominal control system can maintain stability and performance under partial loss of propellers. To further illustrate the effectiveness of passive fault tolerance and the robustness to modeling uncertainty of the proposed control system, validation on the nonlinear six-degree-of-freedom simulator is carried out. The simulation results show that the developed control system using structured H-infinity is able to overcome the partial loss of both a single and two propellers as well as modeling uncertainty during transition flight, which improves the safety and reliability of the flight of the dual-system UAV.