Torque converter clutch control
View Patent ↗A powertrain for a vehicle includes an engine having an output and a transmission selectively driven by the output of the engine. A torque converter is disposed between the engine and the transmission for selectively coupling the output of the engine to the transmission. A controller is in communication with the engine and the torque converter and controls a pressure: within the torque converter based on an input parameter supplied to the engine.
1. A powertrain system for a vehicle, the powertrain system comprising:
an engine having an output;
a transmission selectively driven by said output of said engine;
a torque converter disposed between said engine and said transmission for selectively coupling said output of said engine to said transmission;
a valve in fluid communication with said torque converter and operable to control a fluid flow to adjust a pressure within said torque converter; and
a control system in communication with said valve, said engine and said torque converter, said control system including a feed-forward module and a feedback module, said feed-forward module being operable to anticipate a first volume of fluid necessary to have a desired effect on said pressure based on an input parameter supplied to said engine and provide a first signal to said valve indicative of said first volume, said feedback module generating and providing a second signal to said feed-forward module to adjust a slip speed of said torque converter.
2. The powertrain system of claim 1 , wherein said input parameter is a position of an accelerator.
3. The powertrain system of claim 1 , wherein said input parameter is a position of a throttle associated with said engine.
4. The powertrain system of claim 1 , wherein said feedback control module continuously modulates a pressure within said torque converter.
5. The powertrain system of claim 4 , wherein at least one of said first signal and said second signal is a PID feedback control signal.
6. The powertrain system of claim 1 , wherein said feed-forward module and said feedback module cooperate to provide an output signal to said valve.
7. The powertrain system of claim 1 , wherein said second signal is based on an inertia of a housing and impeller of said torque converter.
8. The powertrain system of claim 1 , wherein at least one of said first and second signals is based on a desired acceleration of the vehicle.
9. A method of controlling a vehicle, the method comprising:
detecting a torque demand on an engine of the vehicle;
generating a first feed-forward signal based on said torque demand;
supplying said first feed-forward signal to a control valve;
operating said control valve into a first position based on said first feed-forward signal to adjust a volume of fluid disposed within a torque converter to a first volume;
supplying fluid to a torque converter associated with said engine via said control valve;
generating an error signal based on a comparison of a measured slip of said torque converter and a desired slip;
generating a second feed-forward signal based on said torque demand and said error signal;
operating said control valve in a second position based on said second feed-forward signal to adjust said volume of fluid disposed within said torque converter to a second volume different than said first volume; and
driving a transmission based on an output of said torque converter to propel the vehicle.
10. The method of claim 9 , wherein said detecting said torque demand on said engine includes determining a position of an accelerator.
11. The method of claim 9 , wherein said detecting said torque demand on said engine includes determining a position of an engine throttle.
12. The method of claim 9 , further comprising providing a PID signal to said control valve to cycle said control valve between an open position and a closed position at a predetermined duty rate.
13. The method of claim 9 , wherein said adjusting said volume of fluid disposed within said torque converter includes supplying additional fluid to said converter to increase a pressure within said torque converter and selectively engage a clutch.
14. The method of claim 9 , further comprising generating a feedback control signal based on said measured slip.
15. The method of claim 9 , wherein generating said second feed-forward signal includes compensating for an inertia of a housing and impeller of said torque converter.
16. The method of claim 9 , wherein at least one of said first and second feed-forward signals is based on a desired acceleration of the vehicle.