Method of operating a hybrid electric vehicle to reduce emissions
AssigneeFord Global Technologies, LLC
InventorsMark William Peters, David Lee Boggs
Life of this patent
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Abstract
A method of operating a hybrid electric vehicle 10 to reduce emissions. The method utilizes the vehicle's electric motor/generator 12 to generate a negative torque during cold-start conditions, effective to increase the load on the internal combustion engine 16, thereby reducing the light-off time of the catalytic converter 28. The method also reduces emissions by utilizing the vehicle's motor/generator 12 to provide a supplemental torque to engine 16 during transient events, thereby reducing the generated mass flow and amount of untreated emissions.
Claims20
A method of operating a hybrid electric vehicle having an internal combustion engine and an electric machine which is operatively coupled to, and selectively provides torque to, the engine, the method comprising:
- detecting at least one of a cold-start condition and a transient event;
- and
- selectively providing a torque to the engine by use of the electric machine, the torque having a value based on the detection and being effective to alter operation of the engine in a manner which reduces exhaust emissions.
A method of operating a hybrid electric vehicle having a drive train, an electric machine which selectively provides torque to the drive train, an engine which selectively provides torque to the drive train and which operates at a certain power output, and a catalytic converter which receives exhaust gas from the engine, the method comprising:
- detecting a transient event;
- and
- selectively providing a positive torque to the drive train by use of the electric machine, the positive torque being effective to supplement the torque provided by the engine and lower the certain power output, thereby lowering exhaust mass flow through the catalytic converter and reducing emissions.
A hybrid electric vehicle, comprising:
- an engine;
- an electric machine operatively coupled to the engine and capable of selectively applying a torque to the engine;
- a plurality of sensors for measuring vehicle operating conditions, each of the sensors being capable of outputting a signal related to a corresponding vehicle operating condition;
- and
- a controller in communication with the engine, the electric machine, and the sensors, the controller being configured to detect at least one of a cold-start condition and a transient event, the detection being based on at least some of the measured vehicle operating conditions, the controller being further configured to command the electric machine to provide torque to the engine based on the detection, the torque being effective to alter operation of the engine to reduce exhaust emissions.
Dependencies are inferred from the claim text.