Pilot downshifting system and method
AssigneeFord Global Technologies, LLC
InventorsKristofor Robert Norman, Shuya Shark Yamada
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for performing a multiple gear downshift of a transmission gear by transiently operating in an intermediate gear. In response to air mass flow not reaching a threshold for CAC self-cleansing for a set duration, the transmission gear may be downshifted from a higher gear to an intermediate gear, and then to a requested lower gear. Downshifting through an intermediate gear may also be controlled based on the gear shift request and maximum air mass flow levels for engine misfire.
Claims21
A method for controlling an engine, comprising:
- boosting intake air through a compressor of a turbocharger;
- direct injecting fuel into a cylinder of the engine;
- and
- in response to airflow through a charge air cooler and a request to downshift a transmission gear from a higher gear to a lower gear, shifting the transmission gear from the higher gear, to an intermediate gear, and then to the lower gear, where the transmission transiently operates at the intermediate gear and engine torque is adjusted at the intermediate gear when an engine throttle is not fully open.
A method for controlling an engine, comprising:
- generating condensate in a charge-air-cooler (CAC) of the engine;
- and
- in response to a multiple gear downshift request and based on estimated condensate formation in the CAC, when air mass flow is less than a threshold range for a threshold duration and the multiple gear downshift request will increase air mass flow over a second threshold level, downshifting a transmission from a higher gear to an intermediate gear to purge condensate, and then to a requested lower gear.
A method for controlling an engine, comprising:
- during a first condition, when an air mass flow is less than a threshold range for a threshold duration, shifting from a higher gear to a requested lower gear by transiently operating at an intermediate gear before shifting to the lower gear;
- during a second condition, when an air mass flow is not less than a threshold range for a threshold duration, shifting from the higher gear to a lower gear when requested, without operating in the intermediate gear;
- and
- selecting between the first and second condition based on charge-air-cooler conditions.
Dependencies are inferred from the claim text.