Study On Fault Diagnosis Technology About Heavy Truck Of AMT

Automated Mechanical Transmission (AMT) realizes the automatic transmission control system by rebuilding traditional MT; it is advanced electronic control system with electronic, mechanical, pneumatic control technology. This paper based on a heavy truck. Its clutch actuator is pneumatic type, the on-off solenoid valve is used to engage and disengage clutch. Transmission actuator is electrodynamics type, direct current electromotor is used to gear shift.AMT is a very complicated system. It brings high efficiency, simplifying driving operations and improving automatic control ability. But the probability of appeared fault will greatly increase. This need advanced fault diagnosis technology to ensure the system's security and reliability. Fault self-diagnosis and disposal is one of the key technologies.The paper includes:(1)Have analyzed the system of AMT gearshift process and influence factor of property of automatic shift, It laid a foundation for fault diagnosis.(2)Have studied methods of AMT fault diagnosis system at home and broad in depth, analyzed fault diagnosis means of signal detection and analytical redundancy, then analyzed methods of fault disposal, it provides a theoretical framework for fault disposal.(3)In vehicle's normal running process, it shall be guaranteed that the parts of AMT are running correctly. The paper base on this point, the failure mechanism of AMT part is analyzed. The fault which occurred in different state has different diagnosis strategy. Have proposed fault disposal in allusion to very corresponding fault.(4)According to the fault diagnosis table, the fault diagnosis process and the simulation model of Simulink are established, the input signal model is established by LabVIEW, Simulink and LabVIEW combined simulation. Have Proved model function through introduce normal and abnormal input signal. The researches can provide basis for develop the fault diagnosis of AMT control system.(5)On AMT test platform, the designed diagnosis strategy is tested. Gearshift fault is made artificially, fault output signal and gearshift actuator motion information are picked, and then they are analyzed to verify the validity of fault diagnosis strategy.