US6405528B1
Expired / Lapsed
US
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Method for determining load on particulate filter for engine exhaust, including estimation of ash content
Assignee: Ford Global Technologies LLC
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Filing: 2000-11-20
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Granted: 2002-06-18
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Expires: 2020-11-20
Abstract
Abstract A method for determining the load on an internal combustion engine exhaust particulate filter optimizes filter regeneration by determining the portion of the filter load constituted by accumulated ash. In one technique, the ash load is determined by recording the lowest value of DPF load over a time or distance interval. In another technique, an estimate is made of the amount of load remaining at each of a plurality of DPF regeneration events; the amount of remaining load immediately following the regeneration event corresponds to the amount of accumulated ash in the DPF. DPF load estimation is performed using equations for laminar or turbulent flow in pipes. These equations establish a linear or quadratic relationship between the flow through the DPF and the pressure drop measured across it.
Inventors
- 👤 Urs Christen
- 👤 Brendan Patrick Carberry
- 👤 Paul Eduard Moraal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:25
CPC Classifications
F; F01; F01N; F01N11/00; F01N11/002; F01N13/00; F01N13/009; F01N13/0097; F01N3/00; F01N3/02; F01N3/021; F01N3/033; F01N3/035; F01N9/00; F01N9/002; F01N2550/00; F01N2550/04; F01N2560/00; F01N2560/08; F02; F02B; F02B29/00; F02B29/04; F02B29/0406; F02B37/00; F02B37/12; F02B37/22; F02D; F02D2200/00; F02D2200/02; F02D2200/08; F02D2200/0812; F02M; F02M26/00; F02M26/02; F02M26/04; F02M26/05; F02M26/13; F02M26/22; F02M26/23; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/40
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
105 words
A method of estimating the amount of inert, incombustible material accumulated in a particulate filter for an internal combustion engine exhaust, comprising the steps of: (A) repeatedly measuring the backpressure load in said filter over a preselected interval, said backpressure load resulting from the trapping and accumulation of both combustible and said inert materials in said filter, the amount of said backpressure load varying over time in part as a result of said filter being periodically regenerated; and (B) determining the smallest backpressure load measured in step (A) over said interval, said smallest determined backpressure load being related to said accumulated amount of inert material.
Claim 2
Independent Claim
105 words
A method of estimating the amount of inert, incombustible material accumulated in a particulate filter for an internal combustion engine exhaust, comprising the steps of: (A) repeatedly measuring the backpressure load in said filter over a preselected interval, said backpressure load resulting from the trapping and accumulation of both combustible and said inert materials in said filter, the amount of said backpressure load varying over time in part as a result of said filter being periodically regenerated; and (B) determining the smallest backpressure load measured in step (A) over said interval, said smallest determined backpressure load being related to said accumulated amount of inert material.
Claim 3
Dependent Claim
65 words
The method of claim 1 , wherein step (B) includes: storing at least certain of the loads measured in step (A) in a memory, and updating said memory each time a load measured in step (A) is lower than the load currently stored in said memory, whereby said memory maintains storage of the lowest value of the load determined in step (A) during said interval.
Claim 4
Dependent Claim
21 words
The method of claim 2 , including the step of recording the time during said each time said memory is updated.
Claim 5
Independent Claim
112 words
A method of estimating the amount of inert material accumulated in a particulate filter for an internal combustion engine exhaust, comprising the steps of: (A) regenerating said filter by increasing the temperature of exhaust gas entering said filter to a level sufficient to incinerate combustible particulates trapped in said filter and representing a backpressure load; (B) detecting the end point of step (A); (C) after completing step (B), determining the remaining load in said particulate filter, said remaining load being related to the accumulated amount of said inert material in said filter; (D) successively repeating steps (A)-(C); and (E) determining the minimum amount of remaining load determined over the successively repeated steps.
Claim 6
Independent Claim
112 words
A method of estimating the amount of inert material accumulated in a particulate filter for an internal combustion engine exhaust, comprising the steps of: (A) regenerating said filter by increasing the temperature of exhaust gas entering said filter to a level sufficient to incinerate combustible particulates trapped in said filter and representing a backpressure load; (B) detecting the end point of step (A); (C) after completing step (B), determining the remaining load in said particulate filter, said remaining load being related to the accumulated amount of said inert material in said filter; (D) successively repeating steps (A)-(C); and (E) determining the minimum amount of remaining load determined over the successively repeated steps.
Claim 7
Dependent Claim
25 words
The method of claim 4 , wherein step (B) is performed by sensing a change in temperature of the exhaust gas flowing through said filter.
Claim 8
Dependent Claim
28 words
The method of claim 4 , wherein step (C) is performed by measuring the pressure drop across said filter after said endpoint has been detected in step (B).
Claim 9
Dependent Claim
22 words
The method of claim 4 , wherein step (B) is performed by determining the rate of change of said measured backpressure load.
Claim 10
Independent Claim
176 words
A method of determining the load in a particulate filter for an internal combustion engine resulting from the accumulation of incombustible particulates in said filter over a preselected interval, wherein the total load in said filter includes both said incombustible and combustible particulates, comprising the steps of: (A) determining the value of the load in said filter at a first time point during said preselected interval; (B) storing the value determined in step (A) in a memory; (C) determining the value of said load in said filter at each of a plurality of time points during said subsequent to said first time point; (D) comparing the values determined in step (C) with the value stored in step (B); and (E) updating said memory based on the comparison performed in step (D) when the comparison performed in step (D) indicates that the value of the load determined at a subsequent time point is less than the previously stored load value, the value stored in said memory at the end of said interval representing said incombustible particulate load.
Claim 11
Independent Claim
176 words
A method of determining the load in a particulate filter for an internal combustion engine resulting from the accumulation of incombustible particulates in said filter over a preselected interval, wherein the total load in said filter includes both said incombustible and combustible particulates, comprising the steps of: (A) determining the value of the load in said filter at a first time point during said preselected interval; (B) storing the value determined in step (A) in a memory; (C) determining the value of said load in said filter at each of a plurality of time points during said subsequent to said first time point; (D) comparing the values determined in step (C) with the value stored in step (B); and (E) updating said memory based on the comparison performed in step (D) when the comparison performed in step (D) indicates that the value of the load determined at a subsequent time point is less than the previously stored load value, the value stored in said memory at the end of said interval representing said incombustible particulate load.
Claim 12
Dependent Claim
24 words
The method of claim 8 , including the step of storing the value of an engine running time each time said memory is updated.
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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) | 2005-06-17 | 2005-12-17 | 2006-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-06-17 | 2009-12-17 | 2010-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-06-17 | 2013-12-17 | 2014-06-18 | $7700.00 | Window Closed / Lapsed |