Browse Publications Technical Papers 2000-05-0128

New Concepts for Control of Power Transients in Flywheel Assisted Drivelines with a CVT 2000-05-0128

Vehicle powertrains with a continuously variable transmission (CVT) have a large freedom in controlling the engine speed and the torque at the wheels. Due to rotating inertias within the engine and transmission, the response of the vehicle during large engine speed shifts may appear reluctant or even counteractive. To overcome this behaviour, the CVT is augmented with a planetary gear set and compact steel flywheel. The new transmission seamlessly combines two contradictive features: the driveability in terms of the pedal-to-wheel response is greatly improved and a large leap towards optimal fuel economy can be made. This can be achieved by cruising the vehicle at extremely low engine speeds which is possible by the large ratio-coverage of the CVT. The latently impassive pedal-to-wheel response that normally would emerge is now eliminated by the gear set and the flywheel. In this paper two control strategies for the engine throttle valve and the CVT ratio shift speed are presented and analysed. The control laws are able to realize high driveability and fuel economy at the same time. Results from simulations will be discussed.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 18% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.

Due to current capacity constraints, printed versions of our publications - including standards, technical papers, EDGE Reports, scholarly journal articles, books, and paint chips - may experience shipping delays of up to four to six weeks. We apologize for any inconvenience.
We also recommend:

Optimal Operation and Control of a Hydrostatic CVT Powertrain


View Details


Comparison of Operational Characteristics in Power Split Continuously Variable Transmissions


View Details


Toyota's New Belt-drive Continuously Variable Transaxle for 1.3-liter FWD cars


View Details