Methods and system for engine control
First Claim
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1. A method for fueling a cylinder, comprising:
- injecting fuel to the cylinder via a first fuel injector and a second fuel injector; and
distinguishing, by processing an exhaust sensor and determining an error associated with the first fuel injector or the second fuel injector from a common fuel system error as a function of a rate of change of air-fuel ratio error and a fraction of fuel injected via the first fuel injector or the second fuel injector, including learning at least a portion of the air-fuel ratio error as the common fuel system error based on whether a first ratio of the rate of change of air-fuel ratio error to the fraction of fuel injected via the first fuel injector is within a threshold of a second ratio of the rate of change of air-fuel ratio error to the fraction of fuel injected via the second fuel injector and whether each of the first ratio and the second ratio is higher than a threshold value.
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Abstract
Systems and methods for determining air-fuel error in an engine fueled via direct and port fuel injection. Errors associated with individual fuel injection systems are distinguished from a common error based on trends in the error correction coefficients of the individual fuel injection systems. Adaptive fuel multipliers for each injection system are updated to account for the common error.
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Citations
17 Claims
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1. A method for fueling a cylinder, comprising:
injecting fuel to the cylinder via a first fuel injector and a second fuel injector; and
distinguishing, by processing an exhaust sensor and determining an error associated with the first fuel injector or the second fuel injector from a common fuel system error as a function of a rate of change of air-fuel ratio error and a fraction of fuel injected via the first fuel injector or the second fuel injector, including learning at least a portion of the air-fuel ratio error as the common fuel system error based on whether a first ratio of the rate of change of air-fuel ratio error to the fraction of fuel injected via the first fuel injector is within a threshold of a second ratio of the rate of change of air-fuel ratio error to the fraction of fuel injected via the second fuel injector and whether each of the first ratio and the second ratio is higher than a threshold value.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for an engine fuel system, comprising:
- injecting fuel to an engine cylinder via a first fuel injector and a second fuel injector during a cylinder cycle, the first and second fuel injectors having distinct types of fuel injection;
selectively assigning, by processing an exhaust sensor and determining an air-fuel error from the cylinder during the cylinder cycle to a common error associated with the fuel system based on each of a first fuel fraction provided by the first fuel injector, a second fuel fraction provided by the second fuel injector, and the air-fuel error, wherein the selectively assigning includes;
learning a first rate of change in the air-fuel error with a change in the first fuel fraction;
learning a second rate of change in the air-fuel error with a change in the second fuel fraction; and
if the first rate is within a threshold difference of the second rate, and each of the first rate and the second rate is higher than a threshold, assigning the air-fuel error to the common error. - View Dependent Claims (11, 12, 13, 14)
- injecting fuel to an engine cylinder via a first fuel injector and a second fuel injector during a cylinder cycle, the first and second fuel injectors having distinct types of fuel injection;
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15. An engine system, comprising:
- an engine including a cylinder;
a port fuel injector in fluidic communication with the cylinder;
a direct fuel injector in fluidic communication with the cylinder;
an exhaust air-fuel ratio sensor; and
a controller including executable instructions stored in non-transitory memory to;
while operating the engine with closed loop air-fuel ratio control based on feedback from the exhaust air-fuel ratio sensor to provide an air-fuel error, differentiate a determined engine fueling error due to degradation of one or more of the port fuel injector and the direct fuel injector from an engine fueling error determined based on the feedback due to a common error in airflow to both the port and direct fuel injectors based on a ratio of a change in air-fuel error to a change in fuel fraction from the port and direct fuel injectors during engine fueling; and
adjust fueling via one or more of the port fuel injector and direct fuel injector responsive to the differentiating, wherein the differentiating includes;
indicating degradation of the port fuel injector when the ratio of the change in air-fuel error to the change in fuel fraction from the port fuel injector is higher than a threshold;
indicating degradation of the direct fuel injector when the ratio of the change in air-fuel error to the change in fuel fraction from the direct fuel injector is lower than a threshold;
indicating engine fueling error due to the common error when the ratio of the change in air-fuel error to the change in fuel fraction from each of the port fuel injector and the direct fuel injector is higher than the threshold and the ratio of the change in air-fuel error to the change in fuel fraction from the port fuel injector is within a threshold of the ratio of the change in air-fuel error to the change in fuel fraction from the direct injector. - View Dependent Claims (16, 17)
- an engine including a cylinder;
Specification