The Desian And Application Research On The Redundant Flight Control System Of UAV

Multirotor UAV(Unmanned Aerial Vehicle)has been dramatically developed these years in industria.Cause the stricter industrial scenarios,drone's reliability gets more attention,and one of the important aspects to improve its reliability is to modify the Flight Control Computer's(FCC)reliability.Redundancy technology is the basic way to modify the FCC reliability,while the traditional one is not available for Multirotor UAVs because of its massive load and size.With the progression of chip level sensor in recent years,like MEMS,makes it possible to design the Redundant Flight control computer(RFCC)in the Multirotor UAV platform.This paper aims to design a small-scale,lightweight and reliable hot-tri-redundant flight control system available for Quadrotor,Hexrcopter and Octocopter Multirotor UAVs from industrial application aspect.The innovation of this paper is that the system uses a strobe/fusion integrated method to make the system more reliable,and with the character of sensor redundancy,output self-monitoring,the ability used in Multirotor platform.The detail of the projects shows below.(1)Single flight control system design:Based on the Pixhawk open-source hardware program,we developed a dual ARM architecture flight control computer with some redundance feature.Then transferred to the APM open source software.This FCC,not only can be used to control UAVs to complete flight tasks independently,but running as a sub-system of the RFCS.Based on the FCC,the UAV of wind turbine blades inspection was developed.(2)Arbitration logic system design:A strobe/fusion integrated arbitration logic is been designed according to the output of flight control diagnostic system and redundancy system,the priorities of each FCC is also been considered when making decision of output mode.And then,developed the hardware system which based on the CPLD.(3)Experimental verification:This RFCC thesis is verified via two methods,simulation and actual flight.The simulation can display the arbitration system's working condition visually in different test examples.The actual flight can verify the exact effect of the arbitration system when introducing the faults,as well as the analysis of perturbation when switching the mode.At the end of this part,two groups of experiment injected faults to simulate the worst scenario was taken to analyze the control system's robustness.The single flight control system introduced in this paper has already been used in multiple UAV projects,including radar calibration,wind turbine blades detection and agriculture protection and successfully passed several tests like vibration and high-and-low temperature.The results of RFCC testified in the experimental platform show that RFCC can reduce the impact caused by flight control sub-system's fault on the whole system and has a great value to improve the whole system's reliability.