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US5558076A Expired / Lapsed US ⏱️ 0.0 years remaining

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
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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 value (desired air/fuel ratio). The engine is equipped with a variable valve timing mechanism which switches the valve timing between characteristics for low engine speed and those for high engine speed. If the characteristic for high engine speed is selected, the second feedback correction coefficient is used for fuel injection quantity correction.

Inventors

  • 👤 Hidetaka Maki
  • 👤 Shusuke Akazaki
  • 👤 Yusuke Hasegawa
  • 👤 Yoichi Nishimura

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 08:01
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1401; F02D41/1402; F01; F01L; F01L1/00; F01L1/26; F01L1/267; F02D13/00; F02D13/02; F02D13/0203; F02D13/0215; F02D13/0261; F02D41/0002; F02D2041/001; F02D2041/1409; F02D2041/1413; F02D2041/1415; F02D2041/142; F02D2041/1426; F02D2041/1433; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y02T10/40

Claims Analysis

Total Claims: 27
Claim 1
Independent Claim 279 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 a 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 the improvement comprising: said engine being provided with a mechanism having an actuator which switches an operating condition of an engine valve; engine valve operation switching means being provided for switching the operating condition of the engine valve through the actuator between a first characteristic (LoV/T) for a low engine speed and a second characteristic (HiV/T) for a high engine speed; and said feedback control means correcting the manipulated variable by the second feedback correction coefficient (KLAF(KSTRL)) when said engine valve operation switching means switches the operating condition of the engine valve to the second characteristic (HiV/T).
Claim 2
Independent Claim 279 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 a 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 the improvement comprising: said engine being provided with a mechanism having an actuator which switches an operating condition of an engine valve; engine valve operation switching means being provided for switching the operating condition of the engine valve through the actuator between a first characteristic (LoV/T) for a low engine speed and a second characteristic (HiV/T) for a high engine speed; and said feedback control means correcting the manipulated variable by the second feedback correction coefficient (KLAF(KSTRL)) when said engine valve operation switching means switches the operating condition of the engine valve to the second characteristic (HiV/T).
Claim 3
Dependent Claim 47 words
A system according to claim 1, wherein said engine valve operation switching means switches the operating condition of the engine valve to the second characteristic (HiV/T) after it has been confirmed that said feedback control means corrected the manipulated variable by the second feedback correction coefficient (KLAF(KSTRL).
Claim 4
Dependent Claim 53 words
A system according to claim 2, wherein said engine valve operation switching means switches the operating condition of the engine valve to the second characteristic (HiV/T) after a predetermined time has passed since it had been confirmed that said feedback control means corrected the manipulated variable by the second feedback correction coefficient (KLAF(KSTRL)).
Claim 5
Dependent Claim 31 words
A system according to claim 1, wherein said engine valve operation switching means switches the operating condition of the engine valve in response to the detected operating condition of the engine.
Claim 6
Dependent Claim 28 words
A system according to claim 1, said first and second feedback correction coefficient calculation means calculate the feedback correction coefficients (KSTR, KLAF(KSTRL)) at least parallel with each other.
Claim 7
Dependent Claim 29 words
A system according to claim 5, wherein said first and second feedback correction coefficient calculation means calculate the feedback correction coefficients (KSTR, KLAF (KSTRL)) in parallel all the time.
Claim 8
Dependent Claim 39 words
A system according to claim 5, wherein said switching means replaces at least one variable of one feedback correction coefficient (KSTR, KLAF(KSTRL)) with a value to be used in a calculation of the other feedback correction coefficient (KLAF(KSTRL), KSTR).
Claim 9
Dependent Claim 25 words
A system according to claim 5, wherein said switching means replaces one feedback correction coefficient (KSTR, KLAF(KSTRL)) with the other feedback correction coefficient (KLAF(KSTRL), KSTR).
Claim 10
Dependent Claim 29 words
A system according to claim 5, wherein said switching means replaces one feedback correction coefficient (KSTR, KLAF(KSTRL)) with a past value of the other feedback correction coefficient (KLAF(KSTRL), KSTR).
Claim 11
Dependent Claim 20 words
A system according to claim 9, wherein the past value is that used in the correction of the manipulated variable.
Claim 12
Dependent Claim 28 words
A system according to claim 2, said first and second feedback correction coefficient calculation means calculate the feedback correction coefficients (KSTR, KLAF(KSTRL)) at least parallel with each other.
Claim 13
Dependent Claim 29 words
A system according to claim 11, wherein said first and second feedback correction coefficient calculation means calculate the feedback correction coefficients (KSTR, KLAF (KSTRL)) in parallel all the time.
Claim 14
Dependent Claim 39 words
A system according to claim 11, wherein said switching means replaces at least one variable of one feedback correction coefficient (KSTR, KLAF(KSTRL)) with a value to be used in a calculation of the other feedback correction coefficient (KLAF(KSTRL), KSTR).
Claim 15
Dependent Claim 25 words
A system according to claim 11, wherein said switching means replaces one feedback correction coefficient (KSTR, KLAF(KSTRL)) with the other feedback correction coefficient (KLAF(KSTRL), KSTR).
Claim 16
Dependent Claim 29 words
A system according to claim 11, wherein said switching means replaces one feedback correction coefficient (KSTR, KLAF(KSTRL)) with a past value of the other feedback correction coefficient (KLAF(KSTRL), KSTR).
Claim 17
Dependent Claim 20 words
A system according to claim 15, wherein the past value is that used in the correction of the manipulated variable.
Claim 18
Dependent Claim 24 words
A system according to claim 1, wherein the first control law having an algorithm expressed in a recursion formula is an adaptive control law.
Claim 19
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 20
Dependent Claim 42 words
A system according to claim 1, 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 21
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 22
Dependent Claim 33 words
A system according to claim 1, wherein said second feedback correction coefficient calculation means calculates the second feedback correction coefficient (KSTRL) using a control law having an algorithm expressed in a recursion formula.
Claim 23
Dependent Claim 22 words
A system according to claim 21, wherein the control having an algorithm expressed in a recursion formula is an adaptive control law.
Claim 24
Dependent Claim 33 words
A system according to claim 2, wherein said second feedback correction coefficient calculation means calculates the second feedback correction coefficient (KSTRL) using a control law having an algorithm expressed in a recursion formula.
Claim 25
Dependent Claim 22 words
A system according to claim 23, wherein the control having an algorithm expressed in a recursion formula is an adaptive control law.
Claim 26
Dependent Claim 29 words
A system according to claim 1, 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 27
Dependent Claim 29 words
A system according to claim 2, wherein said feedback control means corrects the manipulated variable by multiplying the manipulated variable by one of the feedback correction coefficients (KSTR, KLAF(KSTRL)).

References Cited (Backward Citations)

US4674028A Cited
US4922412A Cited
JPH02275043A Cited
JPH04209940A Cited
JPH0552140A Cited
US5220904A Cited
US5443050A Cited
US5462037A Cited

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

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