Method to control a hybrid transmission using on-off switches controlling hydraulic flow to a clutch

摘要

A transmission includes a plurality of synchronously operated clutches selectably transmitting torque from a torque generative device to an output member. A method to control the transmission through a shift event includes monitoring a desired shift event including monitoring a clutch to be engaged, determining a time at which the clutch to be engaged will be synchronized, determining a required clutch fill time for the clutch to be engaged, and actuating an on-off hydraulic control switch selectably providing pressurized hydraulic fluid to the clutch to be engaged based upon coordinating the time at which the clutch to be engaged will be synchronized and the required clutch fill time.

主权项

1. A control module-implemented method to control a transmission through a shift event, the transmission comprising a plurality of synchronously operated clutches selectably transmitting torque from a torque generative device to an output member, the method comprising:
executing in the control module the following steps:
monitoring a desired shift event comprising monitoring a clutch to be engaged;determining a time at which the clutch to be engaged will be synchronized;determining a required clutch fill time for the clutch to be engaged; andactuating a binary on-off hydraulic control switch to commence providing pressurized hydraulic fluid to the clutch to be engaged at the beginning of the clutch fill time and based upon coordinating the time at which the clutch to be engaged will be synchronized simultaneously with the end of the required clutch fill time, wherein a pressure within the clutch to be engaged transitions the clutch to be engaged into a touching state wherein the clutch is filled when the binary on-off switch is actuated;operating the clutch to be engaged in a synchronized state until the pressure within the clutch to be engaged is sufficient to allow for a clutch torque capacity which exceeds a minimum required clutch torque capacity; andpermitting torque to be transferred through the clutch when clutch torque capacity exceeds the minimum required clutch torque capacity.