Predictive stop-start control using state of function during gliding
AssigneeFord Global Technologies, LLC
InventorsMark Eifert, Pankaj Kumar
Life of this patent
Estimating the term…
Abstract
A motor vehicle having a combustion engine for vehicle propulsion can be automatically stopped when engine propulsion is not needed, such as during a gliding condition when the vehicle is coasting down to a slower speed (e.g., stopping) or down an incline. The engine is automatically restarted as needed. To ensure a capacity of a battery or other electrical storage device to support nominal operation of electrical loads (including a starter motor for restarting the engine) during an Auto Stop event, predicted future states of a vehicle battery are determined using a battery state of function (SOF) in response to load transients that may need to be supported.
Claims19
A method of automatically stopping and starting a combustion engine in a motor vehicle, comprising the steps of:
- (a) detecting a gliding condition of the motor vehicle in which a power delivered by the combustion engine can be removed and in which functioning of the motor vehicle can be supported by a battery;
- (b) determining a plurality of battery state of function (SOF) values each corresponding to a respective permissible electrical load that may potentially be actuated during the gliding condition, wherein the battery SOF values each project a respective minimum voltage that would be available at a future time after actuation of the respective permissible electrical load based on an estimated current that would be drawn by the respective permissible electrical load;
- (c) comparing at least one of the battery SOF values to a predetermined threshold voltage;
- (d) if the combustion engine is operating to deliver the power to the motor vehicle and the gliding condition is detected, automatic stopping the combustion engine provided that each battery SOF value in step (c) is greater than the predetermined threshold voltage, whereby automatic stopping of the combustion engine is prohibited when any battery SOF value in step (c) is less than the predetermined threshold voltage;
- and
- (e) if the combustion engine is in an automatically stopped state, then automatically starting the combustion engine when any battery SOF value in the comparing step falls below the predetermined threshold voltage.
A vehicle comprising:
- a combustion engine having a stopped state and a started state, wherein the combustion engine generates propulsion to move the vehicle;
- a generator driven by the engine to generate electrical power;
- a battery storing electrical power received from the generator;
- a plurality of permissible electrical loads operating on electrical power from the battery when the combustion engine is in the stopped state;
- and
- a control circuit configured to:
- (a) detect a gliding condition of the vehicle in which the vehicle is moving without propulsion from the combustion engine;
- (b) determine a plurality of battery state of function (SOF) values each corresponding to a respective permissible electrical load that may potentially be actuated during the gliding condition, wherein the battery SOF values each project a respective minimum voltage that would be available at a future time after actuation of the respective permissible electrical load based on an estimated current that would be drawn by the respective permissible electrical load;
- (c) compare at least one of the battery SOF values to a predetermined threshold voltage;
- (d) when the combustion engine is operating to deliver the power to the motor vehicle and the gliding condition is detected, commence the stopped state of the combustion engine provided that each battery SOF value in (c) is greater than the predetermined threshold voltage, whereby automatic stopping of the combustion engine is prohibited when any battery SOF value in (c) is less than the predetermined threshold voltage;
- and
- (e) when the combustion engine is in the stopped state, then commence the started state of the combustion engine when any battery SOF value in (c) falls below the predetermined threshold voltage.
Dependencies are inferred from the claim text.