Methodology for controlling a hydraulic control system of a continuously variable transmission

摘要

A hydraulic control system for a CVT may include a pressure regulator subsystem, a ratio control subsystem, a torque converter control (TCC) subsystem, a clutch control subsystem, and is enabled for automatic engine start/stop (ESS) functionality. A system and method are provided for performing an engine auto-stop in a vehicle having a CVT transmission and using an accumulator to fill the pulleys and clutches of the CVT, at least in part, during engine restart.

主权项

1. A method for controlling a continuously variable transmission in a motor vehicle having an engine driving the continuously variable transmission, the continuously variable transmission having a hydraulic control system with a pump and an accumulator that provide pressurized hydraulic fluid to a first pulley pair with a first moveable pulley, a second pulley pair with a second moveable pulley, a first clutch, and a second clutch, the method comprising:
receiving, by a controller, an engine on command; commanding the accumulator to open if the engine on command has been received by the controller; commanding a first pulley target pressure to the first moveable pulley; commanding a second pulley target pressure to the second moveable pulley; commanding one of a first clutch fill target pressure to the first clutch or a second clutch fill target pressure to the second clutch; determining whether a first pulley actual pressure is equal to or greater than the first pulley target pressure; determining whether a second pulley actual pressure is equal to or greater than the second pulley target pressure; and commanding one of a first clutch engagement target pressure to the first clutch or a second clutch engagement target pressure to the second clutch if the first pulley actual pressure is equal to or greater than the first pulley target pressure and the second pulley actual pressure is equal to or greater than the second pulley target pressure.