| The fault diagnosis technology of electronic control system is an important means to ensure the safety of ship navigation.At present,the research on the fault diagnosis of marine dual fuel engine is lack of systematic design of fault reasoning and isolation function,which can not provide effective guidance for the maintenance of the system.In order to improve the reliability and convenience of the electronic control system,this paper studies the fault diagnosis technology of the electronic control system of the marine dual fuel engine based on the BIT technology.Firstly,based on the FMEA method,this paper analyzes the possible failure modes and causes of the dual fuel electronic control system,and plans the test methods of each unit.Secondly,in order to systematically carry out the testability design work of the electronic control system,this paper carries out the testability modeling of the dual fuel electronic control system based on the multi signal model,and sets the node failure mode and test node test items of each module based on the information obtained from the FMEA analysis,and obtains the system failure test correlation matrix through the reachability analysis.Through calculation,the FDR and fir of the system are 100% and 96.77% respectively,which meet the needs of engineering.Considering the structure and working mode of the electronic control system,the distributed centralized structure is used to design the bit system,and the fault reasoning algorithm is designed based on the fault test correlation matrix.At the same time,in order to obtain the fault test results of each unit of the electronic control system,the timing signal diagnosis algorithm is designed based on the tooth cycle coefficient to test the fault of multiple teeth and missing teeth.The calibration algorithm of throttle position sensor is developed based on 2δ trust function to detect sensor signal drift.Based on the current waveform,the fault test method of jet valve,injector and metering valve driving module is designed,and the threshold analysis and setting are carried out through Multisim circuit modeling and Monte Carlo analysis.Based on the heartbeat detection,the communication module fault test method is designed.Based on Lab VIEW platform,fault processing and display upper computer software are developed and online test platform is built.ETAS platform and component fault injection are used to simulate and verify the fault.Through the experiments of timing signal processing,throttle control and fuel injector driving control modules,the accuracy of the system fault test,fault reasoning and positioning is verified.The experimental results show that the system can carry out reliable and effective fault online test. |
