CVT Ratio Control Algorithm by Considering Powertrain Response Lag 2004-01-1636
A CVT ratio control algorithm is proposed to improve the engine performance by considering the powertrain response lag. In the CVT powertrain, there exists a response lag, which results from the throttle response, engine torque dynamics, CVT filling time, CVT shift dynamics, and the drive shaft dynamics including the tire. This response lag causes the deviation of the engine operation from the optimal operation line for the minimum fuel consumption. In the CVT ratio control algorithm suggested in this paper, the desired CVT speed ratio is modified from the vehicle velocity, which is estimated after the time delay due to the powertrain response lag. In addition, the acceleration map is constructed to estimate the vehicle acceleration from the throttle pedal position and the CVT ratio. Using the CVT ratio control algorithm and the acceleration map, vehicle performance simulations and experiments are performed to evaluate the engine performance and fuel economy. From the simulation results, it is found that the fuel economy can be improved about 3.6% for FUDS by the ratio control algorithm for the target vehicle. It is found from the experimental results that the engine operation trajectory by the algorithm is shifted to the more efficient brake specific fuel consumption region compared with that of the conventional CVT vehicle, which contributes to the improvement of the fuel economy.
Citation: Lee, H., Kim, C., Kim, T., and Kim, H., "CVT Ratio Control Algorithm by Considering Powertrain Response Lag," SAE Technical Paper 2004-01-1636, 2004, https://doi.org/10.4271/2004-01-1636. Download Citation
Author(s):
Heera Lee, Chulsoo Kim, Talchol Kim, Hyunsoo Kim
Affiliated:
Research & Development Division for Hyundai & Kia Motor Company, School of Mechanical Engineering, Sungkyunkwan University
Pages: 8
Event:
SAE 2004 World Congress & Exhibition
ISSN:
0148-7191
e-ISSN:
2688-3627
Also in:
Transmission and Driveline Symposium 2004-SP-1817, SAE 2004 Transactions Journal of Passenger Cars: Mechanical Systems-V113-6
Related Topics:
Fuel economy
Fuel consumption
Continuously variable transmissions
Simulators
Vehicle acceleration
Powertrains
Mathematical models
Throttles
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