Method Of Adjusting A Fuel Composition Estimate
First Claim
1. A method of adjusting a fuel composition estimate for a vehicle, the method comprising:
- sensing a refueling event;
after sensing the refueling event, determining whether an air-fuel ratio sensor is operable to provide an updated estimate of fuel composition; and
providing an updated fuel composition estimate if the air-fuel ratio sensor is not operable, including performing steps comprising;
monitoring estimated engine torque to determine whether first variations in engine torque over a first period after the refueling event exceed a threshold; and
modifying a previous first fuel composition estimate prior to the refueling event by a first pre-determined amount to determine a second estimate of fuel composition if the first variations in engine torque exceed the threshold after the refueling event and while the air-fuel ratio sensor is not operable for providing an updated fuel composition estimate.
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Abstract
A method is provided for adjusting a fuel composition estimate. The method generally uses a non-fuel related property to determine fuel composition. In some cases the method can be used after refueling and when the engine is operating without the benefit of oxygen sensor data, which can include evaluating data not based on characteristics of the fuel or exhaust from its combustion, such as engine torque variations while using the fuel. The method can include monitoring estimated engine torque to determine whether first variations in engine torque exceed a threshold, and, if so, modifying the previous estimate of fuel composition prior to the refueling event by a pre-determined amount.
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Citations
23 Claims
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1. A method of adjusting a fuel composition estimate for a vehicle, the method comprising:
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sensing a refueling event; after sensing the refueling event, determining whether an air-fuel ratio sensor is operable to provide an updated estimate of fuel composition; and providing an updated fuel composition estimate if the air-fuel ratio sensor is not operable, including performing steps comprising; monitoring estimated engine torque to determine whether first variations in engine torque over a first period after the refueling event exceed a threshold; and modifying a previous first fuel composition estimate prior to the refueling event by a first pre-determined amount to determine a second estimate of fuel composition if the first variations in engine torque exceed the threshold after the refueling event and while the air-fuel ratio sensor is not operable for providing an updated fuel composition estimate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A vehicle comprising:
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an engine configured to operate using a blended fuel; an air-fuel sensor configured to sense a characteristic of the blended fuel; a plurality of system sensors configured to sense actions related to operation of the engine; and an electronic control unit (ECU) in communication with the air-fuel sensor and the plurality of system sensors, the ECU having a processing unit, memory and a storage medium for storing computer-related instructions for instructing the processing unit to perform actions comprising; receiving information from a refueling sensor; determining a refueling event has occurred; determining whether an air-fuel ratio sensor is operable to provide an updated estimate of fuel composition, and if the air-fuel ratio sensor is not operable to provide an updated estimate of fuel composition, performing steps comprising; monitoring estimated engine torque to determine whether first variations in engine torque over a first period after the refueling event exceed a threshold; and modifying a previous first fuel composition estimate prior to the refueling event by a first pre-determined amount to determine a second estimate of fuel composition if the first variations in engine torque exceed the threshold after the refueling event and while the air-fuel ratio sensor is not operable for providing an updated fuel composition estimate. - View Dependent Claims (17, 18, 19)
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20. A computer-readable medium having stored thereon computer-readable instructions, which, when executed by an electronic control unit of a motor vehicle provides instructions to perform actions comprising:
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sensing a refueling event; determining whether an air-fuel ratio sensor is operable to provide an updated estimate of fuel composition after sensing the refueling event and, if the air-fuel ratio sensor is not operable to provide an updated estimate of fuel composition after sensing the refueling event, performing steps comprising; monitoring estimated engine torque to determine whether first variations in engine torque over a first period after the refueling event exceed a threshold; and modifying a previous first fuel composition estimate prior to the refueling event by a first pre-determined amount to determine a second estimate of fuel composition if the first variations in engine torque exceed the threshold after the refueling event and while the air-fuel ratio sensor is not operable for providing an updated fuel composition estimate. - View Dependent Claims (21, 22, 23)
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Specification