Design Of The Software Of Master-slave Fault Tolerant Flight Control Computers Based On FlexRay Bus

Flight control computer is the core of UAV flight control system,its reliability is the key to the safety of unmanned aerial vehicles.Fault tolerance which can be achieved through hardware redundancy configuration and a reasonable fault-tolerant management policy design can effectively improve the reliability of the flight control computer.Based on the sample dual redundant flight control computer hardware platform,the master-slave fault tolerance management strategy is studied and the control software is designed in this dissertation.At first,this dissertation analyzes the redundant characteristics of hardware configuration,and puts forward the requirements of system control software.The master-slave fault tolerant control software development strategy is developed,and the overall design of the system software is completed.Secondly,based on the system bus structure,the design of the FlexRay bus communication layer and the application layer are completed,realizing the reliable communication among functional units.Then,in order to meet the requirement of system fault tolerance,the heartbeat detection method has been applied to diagnose the failures of all functional units and bus,and the task state self-detection method is designed to diagnose control unit software fault,and the method of data update rate statistics and the threshold analysis method based on the continuous moving window smoothing filter is used to achieve the interface unit fault diagnosis.Based on the realization of effective fault diagnosis,fault disposal and fault recovery strategy are designed to realize the fault tolerance of the system.In addition,by adopting the idea of modularization,we complete the development of system software functional modules which realizing the flight control and management and FlexRay bus communication and fault tolerant management functions.Finally,the fault injection software is developed to verify the fault tolerance of the system by simulating the fault.The experimental results show that the function and performance of the masterslave fault tolerant flight control software can meet the design requirements.