Method for controlling a hybrid vehicle
AssigneeFord Global Technologies, LLC
InventorsBrandon Masterson, Dan Colvin
Life of this patent
Estimating the term…
Abstract
A method for controlling a wheel drive system of a hybrid electric vehicle when starting a power source. The hybrid electric vehicle includes first and second power sources, a motor, and a power transfer unit adapted to drive a vehicle wheel. The method includes determining whether the first power source is to be started, determining whether a level of torque requested by a vehicle operator is greater than a threshold value, maintaining a current gear ratio if the threshold value is exceeded, and providing a target level of torque to the power transfer unit.
Claims20
A method for controlling a wheel drive system of a hybrid electric vehicle when starting a power source, the hybrid electric vehicle having first and second power sources, a motor configured to be driven by the first and/or second power sources, and a power transfer unit having a plurality of gear ratios, the power transfer unit configured to be driven by the motor to drive a vehicle wheel, the method comprising:
- determining whether the first power source is to be started;
- determining whether a level of torque requested by a vehicle operator is greater than a threshold value if the first power source is to be started and the hybrid electric vehicle is in motion;
- maintaining a current gear ratio if the level of torque requested by the vehicle operator is greater than the threshold value;
- and
- providing a target level of torque with the motor while the current gear ratio is engaged.
A method for controlling a wheel drive system of a hybrid electric vehicle during a rolling start, the hybrid electric vehicle having first and second power sources, a motor adapted to be powered by at least one of the power sources, and a power transfer unit having a plurality of gear ratios, the power transfer unit being adapted to be driven by the motor to drive a vehicle wheel, the method comprising:
- determining whether to start the first power source;
- determining whether a level of torque requested by a vehicle operator is greater than a threshold value indicative of a level at which a power transfer unit gear ratio downshift would be desired;
- inhibiting a downshift to a lower gear ratio for a predetermined period of time;
- and
- providing an additional amount of torque to the vehicle wheel with the motor and second power source while the downshift to the lower gear ratio is inhibited.
A method for controlling a wheel drive system of a hybrid electric vehicle during an engine start, the hybrid electric vehicle comprising an engine, a voltage source, a power transfer unit adapted to drive a vehicle wheel and having a plurality of gear ratios, a motor-generator selectively coupled to the engine via a first clutch, selectively coupled to the power transfer unit via a second clutch, and adapted to be powered by at least one power sources, the method comprising:
- determining whether an engine start-up is requested while the hybrid electric vehicle is moving;
- determining whether a level of torque requested by a vehicle operator exceeds a threshold value associated with a current gear ratio;
- starting a timer;
- inhibiting a gear ratio shift of the power transfer unit;
- starting the engine;
- calculating an amount of torque to provide to the power transfer unit while in the current gear ratio;
- providing the amount of torque to the power transfer unit with the motor-generator while the engine is being started;
- and
- repeating the inhibiting, calculating, and providing steps until a predetermined period of time measured by the timer has elapsed.
Dependencies are inferred from the claim text.