Digital Twin System for VTOL UAV Fault Diagnosis Based on PX4

Digital twin technology has been used in Unmanned Aerial Vehicle (UAV). However, in the field of fault diagnosis, there is still a lack of a relatively perfect digital twin system for Vertical Takeoff and Landing (VTOL) UAV. Therefore, in this paper, we propose and design a digital twin system for VTOL UAV fault Diagnosis based on PX4 for the first time. Firstly, the VTOL UAV model construction and overall design is carried out. Then, the model of quadrotor and fixed-wing is designed and implemented in the digital twin system, by leaf element method and curve fitting method, respectively. The model of atmospheric density and wind field is also added to the system. Finally, a hardware in the loop (HITL) simulation is carried out, to verify the effectiveness of the digital twin system. The simulation results show that the digital twin system can visually reproduce the data and scenes of physical flight under the conditions of ensuring safety and saving costs. It can also carry out experiments that are difficult to do in reality and verify the impact of the unmodeled state of the mathematical simulation.