Research On Fault Diagnosis Of APU Control System For Extended Range Electric Vehicle

In recent years,with the shortage of energy resources and the serious environmental problems,low-emission new-energy electric vehicles have become the direction of traffic development in the future.As a kind of new-energy electric vehicle,extended-range electric vehicle has better emission characteristics,longer driving range and so on,and has become an important direction for the development of hybrid electric vehicles in the future.The structure of powertrain and its control system of extended range electric vehicle is more complex and needs to be researched on fault diagnosis and fault-tolerant control.It has important academic significance and engineering application value for more safe and reliable control of extended range electric vehicle.This paper discusses the structure and function of APU control system,and the hierarchical control system with fast response is adopted as the control structure of the powertrain of extended range electric vehicle.The working principle of vehicle CAN bus communication is researched.The CAN network topology of APU control system is designed.The communication protocol of power system is designed by CAN standard format and Motorola code format,which provides the foundation for the normal and effective communication between each unit of the control system.This paper uses fault tree analysis method to deduce the deduction of fault in APU system.The working status of APU system was analyzed and the switching logic between various states of the system was discussed.The fault diagnosis of APU control system was also studied.The fault diagnosis program of APU control system was designed and developed by using Stateflow software.The CAN communication fault diagnosis of APU control system is studied,and the CAN communication fault diagnosis simulation model is built.Based on the above research,the fault tolerant control strategy of APU control system is designed and developed.This paper uses UDS fault diagnosis communication protocol to develop fault information transmission system of APU control system,and the diagnostic information transmission program was developed by using Tasking compiler software and DAvE visualization configuration software.The UDS fault information transmission test platform was set up to realize the fault information of APU control system reliable transmission.In addition,using the LabVIEW virtual instrument design and develop the APU fault monitoring system,completed the data transceiver,analysis and storage module,and designed the APU system fault monitoring and alarm interface.This paper sets up a range extender test bench,and test the performance of the fault monitoring system.The test showed that the APU system can receive and send data and monitor faults better.The bench test of APU control system fault diagnosis and fault-tolerant control is carried out.The test results show that the fault diagnosis and fault-tolerant control strategy designed and developed in this paper can diagnose and tolerate the fault of APU control system.