| Civil aviation is an industry with high safety requirements.Civil aircraft must have high operational stability and reliability.In order to ensure its reliability,in the period of design,studying and integration test of Avionics System,the normal operation state of the system and the influence of the abnormal caused by the possible faults on the system should be taken into account.In the process of reliability verification,it is very important to solve the problem of fault injection in the process of data communication between multiple avionics components or hardwares in the loop simulators and real-time scheduling of multi fault tasks.Aiming at the problem of fault injection in the integrated test of Avionics System,this paper studies various types of avionics bus fault injection methods based on Avionics relay system,and realizes the low delay and high speed injection of various avionics bus data.In this paper,a software fault injection method based on data bus is proposed for avionics relay system.Firstly,this paper analyzes the data interaction mode of avionics relay system,selects the bus as the fault injection point,and designs the fault injection architecture of avionics relay system’s reflective memory communication network.Through the analysis of the bus structure,this paper studies a variety of data bus structures,divides the realizable faults into the bus protocol layer fault and the bus application layer fault,gives the implementation method of the faults,and completes the logic design of the fault injection function.Then,the fault management computer is designed according to the fault sub module,and the real-time scheduling algorithm of multi fault tasks is studied.The preemptive scheduling algorithm of dynamic priority is proposed to schedule multi tasks.Dynamic priority comprehensively considers the factors of task deadline,task execution time and so on,and puts forward task urgency and task remaining execution time as the measurement index of dynamic priority.Finally,based on the avionics relay system,the fault injection experiment platform is built to test the effectiveness of fault injection and the failure success rate of multi task scheduling.The results of experiment show that the fault injection method can effectively realize the low delay fault injection of multi-device and multi-channel avionics bus in the protocol layer and application layer,and meet the requirements of avionics system integration test.At the same time,in the multi task scheduling experiment,the fault injection management computer can efficiently allocate resources for fault tasks in real time,the maximum delay of fault injection is low,and the impact on normal data communication of avionics relay system is small.Therefore,the research of fault injection method based on Avionics relay system plays an important role in system integration test and system reliability research. |
