US5558075A
Expired / Lapsed
US
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Fuel metering control system for internal combustion engine
Assignee: Honda Motor Co Ltd
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Filing: 1995-08-14
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Granted: 1996-09-24
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Expires: 2015-08-14
Abstract
Abstract A fuel metering control system for an internal combustion engine, having a feedback loop. In the system, the quantity of fuel injection (Tim) to be supplied to the engine (plant) is determined outside of the feedback loop. A first feedback correction coefficient (KSTR) is calculated using an adaptive law, while a second feedback correction coefficient (KLAF(KSTRL)), whose control response is inferior to the first feedback correction coefficient is calculated, using a PID control law. The feedback correction coefficients are calculated such that the plant output (air/fuel ratio) is brought to a desired (desired air/fuel ratio). A Variable(s) of one coefficients is replaced with a value of the other coefficient such that the one coefficient becomes close to the other. Moreover, the second coefficient (KLAF(KSTRL) is used at a time of returning from open-loop to the feedback control.
Inventors
- 👤 Hidetaka Maki
- 👤 Yusuke Hasegawa
- 👤 Shusuke Akazaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:15
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1473; F02D41/1401; F02D41/1402; F02D41/1477; F02D41/1486; F02D41/1488; F02D2041/1409; F02D2041/1413; F02D2041/1415; F02D2041/142; F02D2041/1426; F02D2041/1433; F02D41/1444; F02D41/1454; F02D41/1456
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
226 words
A system for controlling fuel metering for an internal combustion engine, comprising: air/fuel ratio detecting means for detecting an air/fuel ratio (KACT) of an exhaust gas of the engine; engine operating condition detecting means for detecting an operating condition of the engine; fuel injection quantity determining means for determining a quantity of fuel injection (Tim) to be supplied to the engine; first feedback correction coefficient calculation means for calculating variables to determine a first feedback correction coefficient (KSTR) using a first control law having an algorithm expressed in a recursion formula; second feedback correction coefficient calculation means for calculating variables to determine a second feedback correction coefficient (KLAF(KSTRL)), whose control response is inferior to that of the first feedback correction coefficient, using a second control law; switching means for switching the first feedback correction coefficient (KSTR) and the second feedback correction coefficient (KLAF(KSTRL)) therebetween; and feedback control means for correcting a manipulated variable by the switched one of the feedback correction coefficients (KSTR, KLAF(KSTRL)) to bring at least one of the detected air/fuel ratio (KACT) and the quantity of fuel injection (Tim) to a desired value (KCMD); wherein said switching means replacing at least one of the variables of one of the feedback correction coefficients (KSTR, KLAF(KSTRL)) with a value to be used in a calculation of the other of the feedback correction coefficients (KLAF(KSTRL), KSTR).
Claim 2
Independent Claim
226 words
A system for controlling fuel metering for an internal combustion engine, comprising: air/fuel ratio detecting means for detecting an air/fuel ratio (KACT) of an exhaust gas of the engine; engine operating condition detecting means for detecting an operating condition of the engine; fuel injection quantity determining means for determining a quantity of fuel injection (Tim) to be supplied to the engine; first feedback correction coefficient calculation means for calculating variables to determine a first feedback correction coefficient (KSTR) using a first control law having an algorithm expressed in a recursion formula; second feedback correction coefficient calculation means for calculating variables to determine a second feedback correction coefficient (KLAF(KSTRL)), whose control response is inferior to that of the first feedback correction coefficient, using a second control law; switching means for switching the first feedback correction coefficient (KSTR) and the second feedback correction coefficient (KLAF(KSTRL)) therebetween; and feedback control means for correcting a manipulated variable by the switched one of the feedback correction coefficients (KSTR, KLAF(KSTRL)) to bring at least one of the detected air/fuel ratio (KACT) and the quantity of fuel injection (Tim) to a desired value (KCMD); wherein said switching means replacing at least one of the variables of one of the feedback correction coefficients (KSTR, KLAF(KSTRL)) with a value to be used in a calculation of the other of the feedback correction coefficients (KLAF(KSTRL), KSTR).
Claim 3
Dependent Claim
70 words
A system according to claim 1, wherein said switching means replaces at least one (bo) of the variables of the first feedback correction coefficient(KSTR) with the value (bo/KLAF) that includes the second feedback correction coefficient (KLAF(KSTRL)) such that the first feedback correction coefficient (KSTR(k)) becomes close to the second feedback correction coefficient (KLAF(KSTRL), when said switching means switches the feedback correction coefficient from the second (KLAF(KSTRL)) to the first (KSTR).
Claim 4
Dependent Claim
23 words
A system according to claim 2, wherein the value (bo/KLAF) includes the second feedback correction coefficient (KLAF(KSTRL)) calculated at a preceding control cycle.
Claim 5
Dependent Claim
69 words
A system according to claim 1, wherein said switching means replaces at least one (KLAFI) of the variables of the second feedback correction coefficient (KLAF(KSTRL)) with a value of the first feedback correction coefficient (KSTR) such that the second feedback correction coefficient (KLAF(KSTRL)) becomes close to the first feedback correction coefficient (KSTR), when said switching means switches the feedback correction coefficient from the first (KSTR) to the second (KLAF(KSTRL)).
Claim 6
Dependent Claim
24 words
A system according to claim 1, wherein the value of the first feedback correction coefficient (KSTR) is that calculated at a preceding control cycle.
Claim 7
Dependent Claim
23 words
A system according claim 2, wherein said switching means replaces the variable when the detected air/fuel ratio (KACT) is within a predetermined range.
Claim 8
Dependent Claim
20 words
A system according to claim 6, wherein said predetermined range is 1.0 or thereabout in terms of an equivalence ratio.
Claim 9
Dependent Claim
51 words
A system according to claim 2, wherein said first feedback correction coefficient calculation means includes: comparing means for comparing the first feedback correction coefficient with a threshold value (KSTRref1); and said switching means replaces the variable with a value when the first feedback correction coefficient (KSTR) is below a threshold value.
Claim 10
Dependent Claim
69 words
A system according to claim 8, wherein said first feedback correction coefficient calculation means includes: second comparing means for comparing the first feedback correction coefficient (KSTR) with a second threshold value (KSTRref2); and said first feedback correction coefficient means resets the first feedback correction coefficient (KSTR) to an initial value of the first feedback correction coefficient (KSTR), when the first feedback correction coefficient (KSTR) exceeds the second threshold value.
Claim 11
Dependent Claim
24 words
A system according to claim 4, wherein said switching means replaces the variable when an engine coolant temperature is less than a prescribed temperature.
Claim 12
Dependent Claim
24 words
A system according to claim 4, wherein said switching means replaces the variable when an engine speed is not less than a prescribed speed.
Claim 13
Dependent Claim
18 words
A system according to claim 4, wherein said switching means replaces the variable when the engine is idling.
Claim 14
Dependent Claim
19 words
A system according to claim 4, wherein said switching means replaces the variable when an engine load is low.
Claim 15
Dependent Claim
42 words
A system according to claim 2, wherein said second feedback correction coefficient calculation means calculates the second feedback correction coefficient (KLAF) using a PID control law at least including one from among a proportional term, an integral term and a differential term.
Claim 16
Dependent Claim
42 words
A system according to claim 4, wherein said second feedback correction coefficient calculation means calculates the second feedback correction coefficient (KLAF) using a PID control law at least including one from among a proportional term, an integral term and a differential term.
Claim 17
Dependent Claim
21 words
A system according to claim 14, wherein the one (KLAFI) of the second feedback correction coefficient (KLAF(KSTRL)) is the integral term.
Claim 18
Dependent Claim
35 words
A system according to claim 2, wherein said second feedback correction coefficient calculation means calculates the second feedback correction coefficient (KSTRL) using the second control law that has an algorithm expressed in a recursion formula.
Claim 19
Dependent Claim
25 words
A system according to claim 17, wherein the second control law that has an algorithm expressed in a recursion formula is an adaptive control law.
Claim 20
Dependent Claim
35 words
A system according to claim 4, wherein said second feedback correction coefficient calculation means calculates the second feedback correction coefficient (KSTRL) using the second control law that has an algorithm expressed in a recursion formula.
Claim 21
Dependent Claim
25 words
A system according to claim 19, wherein the second control law that has an algorithm expressed in a recursion formula is an adaptive control law.
Claim 22
Dependent Claim
24 words
A system according to claim 2, wherein the first control law having an algorithm expressed in a recursion formula is an adaptive control law.
Claim 23
Dependent Claim
29 words
A system according to claim 4, wherein said feedback control means corrects the manipulated variable by multiplying the manipulated variable by one of the feedback correction coefficients (KSTR, KLAF(KSTRL)).
Claim 24
Independent Claim
208 words
A system for controlling fuel metering for an internal combustion engine, comprising: air/fuel ratio detecting means for detecting an air/fuel ratio (KACT) of an exhaust gas of the engine; engine operating condition detecting means for detecting an operating condition of the engine; fuel injection quantity determining means for determining a quantity of fuel injection (Tim) to be supplied to the engine; first feedback correction coefficient calculation means for calculating a first feedback correction coefficient (KSTR) using a first control law having an algorithm expressed in recursion formula; second feedback correction coefficient calculation means for calculating a second feedback correction coefficient (KLAF(KSTRL)), whose control response is inferior to that of the first feedback correction coefficient, using a second control law; switching means for switching the first feedback correction coefficient (KSTR) and the second feedback correction coefficient (KLAF(KSTRL)) therebetween; and feedback control means for correcting a manipulated variable by the switched one of the feedback correction coefficients (KSTR, KLAF(KSTRL)) to bring at least one of the detected air/fuel ratio (KACT) and the quantity of fuel injection (Tim) to a desired value (KCMD); wherein said feedback control means correcting the manipulated variable by the second feedback correction coefficient (KLAF(KSTRL)) at a specific condition when returning from open-loop to the feedback control.
Claim 25
Independent Claim
208 words
A system for controlling fuel metering for an internal combustion engine, comprising: air/fuel ratio detecting means for detecting an air/fuel ratio (KACT) of an exhaust gas of the engine; engine operating condition detecting means for detecting an operating condition of the engine; fuel injection quantity determining means for determining a quantity of fuel injection (Tim) to be supplied to the engine; first feedback correction coefficient calculation means for calculating a first feedback correction coefficient (KSTR) using a first control law having an algorithm expressed in recursion formula; second feedback correction coefficient calculation means for calculating a second feedback correction coefficient (KLAF(KSTRL)), whose control response is inferior to that of the first feedback correction coefficient, using a second control law; switching means for switching the first feedback correction coefficient (KSTR) and the second feedback correction coefficient (KLAF(KSTRL)) therebetween; and feedback control means for correcting a manipulated variable by the switched one of the feedback correction coefficients (KSTR, KLAF(KSTRL)) to bring at least one of the detected air/fuel ratio (KACT) and the quantity of fuel injection (Tim) to a desired value (KCMD); wherein said feedback control means correcting the manipulated variable by the second feedback correction coefficient (KLAF(KSTRL)) at a specific condition when returning from open-loop to the feedback control.
Claim 26
Dependent Claim
19 words
A system according to claim 23, wherein the specific condition is a condition just after returning from the open-loop.
Claim 27
Dependent Claim
27 words
A system according to claim 23, wherein the specific condition is a condition in which it is in a predetermined period (C) after returning from the open-loop.
Claim 28
Dependent Claim
30 words
A system according to claim 23, wherein the returning from open-loop to the feedback control is a time of resuming of supply of fuel that has once been cut off.
Claim 29
Dependent Claim
24 words
A system according to claim 23, wherein the first control law having an algorithm expressed in a recursion formula is an adaptive control law.
Claim 30
Dependent Claim
42 words
A system according to claim 23, wherein said second feedback correction coefficient calculation means calculates the second feedback correction coefficient (KLAF) using a PID control law at least including one from among a proportional term, an integral term and a differential term.
Claim 31
Dependent Claim
29 words
A system according to claim 23, wherein said feedback control means corrects the manipulated variable by multiplying the manipulated variable by one of the feedback correction coefficients (KSTR, KLAF(KSTRL)).
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-09-24 | 2000-03-25 | 2000-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-24 | 2004-03-25 | 2004-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-24 | 2008-03-25 | 2008-09-24 | $7700.00 | Window Closed / Lapsed |