Research On Simulation For Shift Control System Of Hydraulic Automatic Transmission

The shift strategy is the core content of automatic transmission, through itsresearch, the vehicle shift control strategy and means and effect can be furtherimproved, we can ensure the best power or economy for the vehicle. Based on theNational863Project” research and development on the powertrain technologyplatform of hybrid car”, this paper studies the4AT automatic transmission controlsystem.Matched on the engine and torque converter’s common work input and outputcharacteristics, defined the shutting pattern control raw of hydraulic torqueconverter lockup clutch; built the best power and economy shift rules with thethrottle angle and vehicle speed; add intelligent shift schedule such as fuzzy controlalgorithm to modified two parameter shift schedule; based on the actual situationthat brake appeared but electronic throttle stuck, consider adjust the shift controlstrategy in different intensity of brake. The driver model, the engine model, vehiclemodel, transmission model and the automatic shifting model was set up based onthe math models of the whole vehicle. Finally, simulation under the severalcondition showed that the automatic transmission model works as expected and canshift by the shifting rule exactly.Analysis of the simulation results, the4AT control system established in thispaper is correct, it can in strict accordance with the automatic shift control law, thestudy achieved desired results. This paper laid a foundation and provides areference for the further development of the automatic transmission.