Patent US5228421A successfully refreshed from Google Patents.
US5228421A
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Idle speed control system
Assignee: Ford Global Technologies LLC
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Filing: 1992-10-28
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Granted: 1993-07-20
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Expires: 2012-10-28
Abstract
Abstract An idle speed control system includes a bypass throttling device coupled in parallel with the primary engine throttle. At the beginning of each idle speed control period, a controller generates an initial bypass throttle position from a desired or reference engine speed. Correction of this initial position is provided based upon a learned error between initial bypass throttle position and the actual position which is maintained by feedback control. The learning routine is enabled in response to an indication that the quantity of inducted fuel vapors is below a minimum value.
Inventors
- 👤 Daniel V. Orzel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:09
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/24; F02D41/2406; F02D41/2425; F02D41/2429; F02D41/2441; F02D41/2448; F02D31/00; F02D31/001; F02D31/002; F02D31/003; F02D31/005; F02D41/0025; F02D41/003; F02D41/0042; F02D41/2451
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
147 words
A method for controlling engine idle speed of a motor vehicle having a fuel vapor recovery system coupled to the engine air intake through a control valve, comprising the steps of: initiating idle speed control during each period when engine operating parameters are in a predetermined state; calculating a desired engine speed upon said initiation of said idle speed control period; generating an initial throttle position for a bypass throttling device based upon said desired engine speed; correcting said initial throttle position upon said initiation of said idle speed control period by a correction factor calculated during a previous idle speed control period; updating said correction factor during current idle speed control operation for application during a subsequent idle speed control period by learning average difference between said desired engine speed and actual engine speed; and inhibiting said learning during actuation of the fuel vapor recovery valve.
Claim 2
Independent Claim
147 words
A method for controlling engine idle speed of a motor vehicle having a fuel vapor recovery system coupled to the engine air intake through a control valve, comprising the steps of: initiating idle speed control during each period when engine operating parameters are in a predetermined state; calculating a desired engine speed upon said initiation of said idle speed control period; generating an initial throttle position for a bypass throttling device based upon said desired engine speed; correcting said initial throttle position upon said initiation of said idle speed control period by a correction factor calculated during a previous idle speed control period; updating said correction factor during current idle speed control operation for application during a subsequent idle speed control period by learning average difference between said desired engine speed and actual engine speed; and inhibiting said learning during actuation of the fuel vapor recovery valve.
Claim 3
Dependent Claim
50 words
The control method recited in claim 1 further comprising the step of maintaining said actual engine speed at said desired engine speed during said current idle speed control operation by adjusting said corrected initial throttle position in response to comparisons of said desired engine speed with said actual engine speed.
Claim 4
Dependent Claim
44 words
The control method recited in claim 1 further comprising the steps of calculating flow rate of inducted fuel vapors in response to an exhaust gas oxygen sensor and deactuating said fuel vapor recovery valve when said calculated quantity is less than a predetermined value.
Claim 5
Independent Claim
171 words
A method for controlling engine idle speed of a motor vehicle having a fuel vapor recovery system coupled to the engine air intake through a control valve, comprising the steps of: initiating idle speed control during each period when engine operating parameters remain in a predetermined state; calculating a desired engine speed upon said initiation of said idle speed control period; generating an initial throttle position for a throttling device bypassing a primary engine throttle valve, said initial bypass throttle position being based upon said desired engine speed; correcting said initial bypass throttle position upon said initiation of said idle speed control period by a correction factor calculated by comparing said desired engine speed to actual engine speed during a previous idle speed control period; and learning a new correction factor during current idle speed control operation for application during a subsequent idle speed control period, said learning being enabled in response to an indication that quantity of recovered fuel vapors inducted into the engine is less than a preselected value.
Claim 6
Independent Claim
171 words
A method for controlling engine idle speed of a motor vehicle having a fuel vapor recovery system coupled to the engine air intake through a control valve, comprising the steps of: initiating idle speed control during each period when engine operating parameters remain in a predetermined state; calculating a desired engine speed upon said initiation of said idle speed control period; generating an initial throttle position for a throttling device bypassing a primary engine throttle valve, said initial bypass throttle position being based upon said desired engine speed; correcting said initial bypass throttle position upon said initiation of said idle speed control period by a correction factor calculated by comparing said desired engine speed to actual engine speed during a previous idle speed control period; and learning a new correction factor during current idle speed control operation for application during a subsequent idle speed control period, said learning being enabled in response to an indication that quantity of recovered fuel vapors inducted into the engine is less than a preselected value.
Claim 7
Dependent Claim
26 words
The method recited in claim 4 wherein said idle speed control initiating step is responsive to an indication of said primary engine throttle being substantially closed.
Claim 8
Dependent Claim
54 words
The method recited in claim 4 further comprising a step of maintaining said actual engine speed at said desired engine speed during said current idle speed control operation by continuously adjusting said bypass throttle in response to a feedback variable derived from a comparison of said desired engine speed to said actual engine speed.
Claim 9
Dependent Claim
165 words
An idle speed control system for a motor vehicle having a fuel vapor recovery system coupled to an engine air intake through a control valve, comprising: an idle speed controller for controlling a bypass throttle coupled to the engine air intake in response to a feedback variable and an initial throttle position signal and an initial throttle position correction signal; feedback means for generating said feedback variable by integrating a difference between said desired engine speed and said actual engine speed; positioning means for converting said desired engine speed into said initial throttle position signal; and learning means for generating said initial throttle position correction signal by integrating said feedback variable and concurrently driving said feedback variable towards zero to learn an average difference between said initial throttle position and actual throttle position maintained by said idle speed controller, said learning means being enabled when an indication is provided that quantity of recovered fuel vapors inducted into the engine is less than a preselected value.
Claim 10
Dependent Claim
165 words
An idle speed control system for a motor vehicle having a fuel vapor recovery system coupled to an engine air intake through a control valve, comprising: an idle speed controller for controlling a bypass throttle coupled to the engine air intake in response to a feedback variable and an initial throttle position signal and an initial throttle position correction signal; feedback means for generating said feedback variable by integrating a difference between said desired engine speed and said actual engine speed; positioning means for converting said desired engine speed into said initial throttle position signal; and learning means for generating said initial throttle position correction signal by integrating said feedback variable and concurrently driving said feedback variable towards zero to learn an average difference between said initial throttle position and actual throttle position maintained by said idle speed controller, said learning means being enabled when an indication is provided that quantity of recovered fuel vapors inducted into the engine is less than a preselected value.
Claim 11
Dependent Claim
50 words
The idle speed control system recited in claim 7 further comprising commencement means for commencing idle speed control during each period when engine operating parameters are in a predetermined state and wherein positioning means generates said initial throttle position upon said commencement of each of said idle speed control periods.
Claim 12
Dependent Claim
28 words
The idle speed control system recited in claim 8 wherein said feedback means resets said feedback variable upon said commencement of each of said idle speed control periods.
Claim 13
Dependent Claim
48 words
The idle speed control system recited in claim 7 wherein said feedback means and said positioning means and said learning means generate said respective feedback variable and said initial throttle position and said initial throttle position correction signal for each of a plurality of engine load operating conditions.
Claim 14
Dependent Claim
40 words
The idle speed control system recited in claim 7 wherein said indication of said recovered fuel vapors being less than a preselected value is provided by integrating a difference between an integral of an exhaust gas oxygen sensor from unity.
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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) | 1996-07-19 | 1997-01-18 | 1997-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-19 | 2001-01-18 | 2001-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-19 | 2005-01-18 | 2005-07-20 | $7700.00 | Window Closed / Lapsed |