MODEL-BASED INTEGRATED CONTROL OF ENGINE AND CVT TO MINIMIZE FUEL USE |
Heeyun Lee1, Juyean Sung2, Hyeokjun Lee3, Chunhua Zheng4, Wonsik Lim5, Suk Won Cha1 |
1Seoul National University 2Seoul National University of Science & Technology 3Hyundai Motor Company 4Chinese Academy of Sciences 5Seoul National University of Technology |
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ABSTRACT |
In this study, a model-based integrated control method for engines and continuous variable transmissions (CVTs) is developed. CVT refers to a type of transmission which allows an engine to be operated independently with respect to the vehicle speed, with the engine torque and CVT gear ratio controlled in an integrated manner. In the proposed integrated control scheme, engine operating points which minimize the rate of instantaneous fuel consumption are calculated, and the engine target torque and target gear ratio are determined in an integrated manner based on the results of the calculations. Unlike the previous map-based control method, the method introduced in this study does not require an engine torque map or a CVT ratio map for tuning, and the engine torque and CVT ratio are controlled to minimize the amount of fuel used while satisfying the level of acceleration demand from the driver. The control scheme is based on the powertrain model, and the CVT response lag and transmission loss are also considered in the integrated control processes. The algorithm is simulated with various driving cycles, with the simulation results showing that the fuel economy performance of the vehicle system is improved with the newly suggested engine-CVT integrated control algorithm. |
Key Words:
Continuously variable transmission, Integrated control, Fuel consumption, Model-based control |
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