Vehicle and engine control system and method
AssigneeFord Global Technologies, LLC
InventorsJohn David Russell, Allan Joseph Kotwicki
Life of this patent
Estimating the term…
Abstract
An engine control system controls engine torque to transition through the transmission lash zone. The transmission lash zone is determined using speed ratio across the torque converter. When near the transmission lash zone, engine torque is adjusted at a predetermined rate until the system passes through the transmission lash zone. By limiting the change of torque in this way, driveability is improved and it is possible to quickly and reliably provide negative engine torque for braking.
Claims25
A method for estimating when a vehicle is near a transmission lash zone, the vehicle having an internal combustion engine coupled to a transmission via a torque converter having a speed ratio from torque converter output speed to torque converter input speed, the method comprising the steps of:
- indicating when the speed ratio is within a predetermined range;
- and
- determining that the vehicle is near the transmission lash zone in response to said indication.
A vehicle control method for a vehicle having an internal combustion engine coupled to a torque converter, the torque converter having a speed ratio from torque converter output speed to torque converter input speed, the torque converter coupled to a transmission, the method comprising the steps of:
- indicating when the speed ratio is within a predetermined range;
- and
- in response to said indication, adjusting an operating parameter to control a change in an engine output to be less than a preselected value.
A control method for a vehicle having an internal combustion engine coupled to a transmission via a torque converter having an input speed and an output speed, the method comprising the steps of:
- determining a speed ratio across the torque converter based on said input speed and said output speed;
- and
- controlling an engine operating parameter at a preselected rate when said speed ratio is within a predetermined range.
An article of manufacture comprising:
- a computer storage medium having a computer program encoded therein for controlling a vehicle having an internal combustion engine coupled to a torque converter, the torque converter having an input speed and an output speed, the torque converter coupled to a transmission, said computer storage medium comprising:
- code for determining a speed ratio across the torque converter based on said input speed and said output speed;
- and
- code for controlling an engine torque at a preselected rate when said speed ratio is between a lower limit value and an upper limit value and when the torque converter is in an unlocked state, said lower limit value and said upper limit value are based on an operating parameter.
Dependencies are inferred from the claim text.