Patent US5726352A successfully refreshed from Google Patents.
US5726352A
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Method of detecting misfires in a multicylinder internal combustion engine
Assignee: Robert Bosch GmbH
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Filing: 1996-05-17
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Granted: 1998-03-10
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Expires: 2016-05-17
Abstract
Abstract The invention is directed to a method for detecting combustion misfires in a multicylinder internal combustion engine. The method includes the steps of: detecting the time span ts(i) in which the crankshaft of the engine passes through a pregiven angular range (φ) for each ignition of the engine; computing a vector element Lut(i) for the rough running of the engine based on at least one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with the two vector elements Lut(i), Lut(j) being for each ignition (i); computing the spacing between the vector LUT(i) and at least one predetermined reference vector Rn and Ra; and, detecting a combustion misfire when the spacing satisfies a predetermined condition.
Inventors
- 👤 Manfred Mezger
- 👤 Asmus Volkart
- 👤 Klaus Ries-Muller
- 👤 Rainer Frank
- 👤 Sigrid Hafner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:20
CPC Classifications
G; G01; G01M; G01M15/00; G01M15/04; G01M15/11; F; F02; F02M; F02M65/00
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
167 words
A method for detecting combustion misfires in a multicylinder internal combustion engine, the method comprising the steps of: detecting a time span ts(i) in which the crankshaft of the engine passes through a pregiven angular range (φ) for each ignition of the engine; computing a vector element Lut(i) for a rough running of the engine based on at least said one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with said two vector elements Lut(i), Lut(j) being for each ignition (i); computing a spacing between said vector LUT(i) and at least one predetermined reference vector Rn and Ra; detecting a combustion misfire when said spacing satisfies a predetermined condition; forming a corrective quantity (K) when computing an individual vector component Lut(i) to correct and compensate for an influence of mean rpm changes of the engine on said time span ts(i); and, considering said corrective quantity (K) when computing an individual vector component.
Claim 2
Independent Claim
167 words
A method for detecting combustion misfires in a multicylinder internal combustion engine, the method comprising the steps of: detecting a time span ts(i) in which the crankshaft of the engine passes through a pregiven angular range (φ) for each ignition of the engine; computing a vector element Lut(i) for a rough running of the engine based on at least said one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with said two vector elements Lut(i), Lut(j) being for each ignition (i); computing a spacing between said vector LUT(i) and at least one predetermined reference vector Rn and Ra; detecting a combustion misfire when said spacing satisfies a predetermined condition; forming a corrective quantity (K) when computing an individual vector component Lut(i) to correct and compensate for an influence of mean rpm changes of the engine on said time span ts(i); and, considering said corrective quantity (K) when computing an individual vector component.
Claim 3
Independent Claim
181 words
A method for detecting combustion misfires in a multicylinder internal combustion engine, the method comprising the steps of: detecting a time span ts(i) in which the crankshaft of the engine passes through a pregiven angular range (φ) for each ignition of the engine; computing a vector element Lut(i) for a rough running of the engine based on at least said one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with said two vector elements Lut(i), Lut(j) being for each ignition (i); computing a spacing between said vector LUT(i) and at least one predetermined reference vector Rn and Ra; detecting a combustion misfire when said spacing satisfies a predetermined condition; utilizing various reference vectors for various load/rpm ranges of the engine; predetermining a reference vector Rn for each load-rpm region which is characteristic for misfire-free normal operation; and, detecting a misfire when a spacing between said vector LUT(i), which is formed for an ignition (i), and the reference vector Rn corresponding thereto exceeds a predetermined threshold value.
Claim 4
Independent Claim
181 words
A method for detecting combustion misfires in a multicylinder internal combustion engine, the method comprising the steps of: detecting a time span ts(i) in which the crankshaft of the engine passes through a pregiven angular range (φ) for each ignition of the engine; computing a vector element Lut(i) for a rough running of the engine based on at least said one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with said two vector elements Lut(i), Lut(j) being for each ignition (i); computing a spacing between said vector LUT(i) and at least one predetermined reference vector Rn and Ra; detecting a combustion misfire when said spacing satisfies a predetermined condition; utilizing various reference vectors for various load/rpm ranges of the engine; predetermining a reference vector Rn for each load-rpm region which is characteristic for misfire-free normal operation; and, detecting a misfire when a spacing between said vector LUT(i), which is formed for an ignition (i), and the reference vector Rn corresponding thereto exceeds a predetermined threshold value.
Claim 5
Independent Claim
181 words
A method for detecting combustion misfires in a multicylinder internal combustion engine, the method comprising the steps of: detecting a time span ts(i) in which the crankshaft of the engine passes through a pregiven angular range (φ) for each ignition of the engine; computing a vector element Lut(i) for a rough running of the engine based on at least said one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with said two vector elements Lut(i), Lut(j) being for each ignition (i); computing a spacing between said vector LUT(i) and at least one predetermined reference vector Rn and Ra; detecting a combustion misfire when said spacing satisfies a predetermined condition; utilizing various reference vectors for various load/rpm ranges of the engine; predetermining a reference vector Ra for each load-rpm region which is characteristic for operation with misfires; and, detecting a misfire when a spacing between the vector LUT(i), which is formed for an ignition (i), and the reference vector Ra corresponding thereto exceeds a predetermined threshold value.
Claim 6
Independent Claim
181 words
A method for detecting combustion misfires in a multicylinder internal combustion engine, the method comprising the steps of: detecting a time span ts(i) in which the crankshaft of the engine passes through a pregiven angular range (φ) for each ignition of the engine; computing a vector element Lut(i) for a rough running of the engine based on at least said one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with said two vector elements Lut(i), Lut(j) being for each ignition (i); computing a spacing between said vector LUT(i) and at least one predetermined reference vector Rn and Ra; detecting a combustion misfire when said spacing satisfies a predetermined condition; utilizing various reference vectors for various load/rpm ranges of the engine; predetermining a reference vector Ra for each load-rpm region which is characteristic for operation with misfires; and, detecting a misfire when a spacing between the vector LUT(i), which is formed for an ignition (i), and the reference vector Ra corresponding thereto exceeds a predetermined threshold value.
Claim 7
Independent Claim
200 words
A method for detecting combustion misfires in a multicylinder internal combustion engine, the method comprising the steps of: detecting a time span ts(i) in which the crankshaft of the engine passes through a pregiven angular range (φ) for each ignition of the engine; computing a vector element Lut(i) for a rough running of the engine based on at least said one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with said two vector elements Lut(i), Lut(j) being for each ignition (i); computing a spacing between said vector LUT(i) and at least one predetermined reference vector Rn and Ra; detecting a combustion misfire when said spacing satisfies a predetermined condition; utilizing various reference vectors for various load/rpm ranges of the engine; predetermining at least two reference vectors Rn and Ra for each load-rpm region with reference vector Rn being for misfire-free normal operation and reference vector Ra being for operation with misfires; and, detecting a misfire when a spacing between the vector LUT(i), which is formed for ignition (i), and the vector Rn is greater than the spacing between the vector LUT(i) and the vector Ra.
Claim 8
Independent Claim
200 words
A method for detecting combustion misfires in a multicylinder internal combustion engine, the method comprising the steps of: detecting a time span ts(i) in which the crankshaft of the engine passes through a pregiven angular range (φ) for each ignition of the engine; computing a vector element Lut(i) for a rough running of the engine based on at least said one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with said two vector elements Lut(i), Lut(j) being for each ignition (i); computing a spacing between said vector LUT(i) and at least one predetermined reference vector Rn and Ra; detecting a combustion misfire when said spacing satisfies a predetermined condition; utilizing various reference vectors for various load/rpm ranges of the engine; predetermining at least two reference vectors Rn and Ra for each load-rpm region with reference vector Rn being for misfire-free normal operation and reference vector Ra being for operation with misfires; and, detecting a misfire when a spacing between the vector LUT(i), which is formed for ignition (i), and the vector Rn is greater than the spacing between the vector LUT(i) and the vector Ra.
Claim 9
Dependent Claim
55 words
The method of claim 1, comprising a further step of subtracting the corrective quantity (K) from a base term (B) to compute an individual vector component Lut(i) wherein said base term (B) and said corrective term (K) are each formed from individual assigned times ts(i-j), . . . , ts(i), . . . , ts(i+j).
Claim 10
Dependent Claim
20 words
The method of claim 5, wherein vector component Lut(i) is given as: ##EQU7## wherein: (z)=number of cylinders of the engine.
Claim 11
Independent Claim
144 words
A method for detecting combustion misfires in a multicylinder internal combustion engine, the method comprising the steps of: detecting a time span ts(i) in which the crankshaft of the engine passes through a pregiven angular range (φ) for each ignition of the engine; computing a vector element Lut(i) for a rough running of the engine based on at least said one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with said two vector elements Lut(i), Lut(j) being for each ignition (i); computing a spacing between said vector LUT(i) and at least one predetermined reference vector Rn and Ra; detecting a combustion misfire when said spacing satisfies a predetermined condition; and, the vector LUT(i) is given as: LUT(i)=(Lut(i), . . . , Lut(i+z-1)) wherein: (z)=number of cylinders of the engine.
Claim 12
Independent Claim
144 words
A method for detecting combustion misfires in a multicylinder internal combustion engine, the method comprising the steps of: detecting a time span ts(i) in which the crankshaft of the engine passes through a pregiven angular range (φ) for each ignition of the engine; computing a vector element Lut(i) for a rough running of the engine based on at least said one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with said two vector elements Lut(i), Lut(j) being for each ignition (i); computing a spacing between said vector LUT(i) and at least one predetermined reference vector Rn and Ra; detecting a combustion misfire when said spacing satisfies a predetermined condition; and, the vector LUT(i) is given as: LUT(i)=(Lut(i), . . . , Lut(i+z-1)) wherein: (z)=number of cylinders of the engine.
Claim 13
Independent Claim
160 words
A method for detecting combustion misfires in a multicylinder internal combustion engine, the method comprising the steps of: detecting a time span ts(i) in which the crankshaft of the engine passes through a pregiven angular range (φ) for each ignition of the engine; computing a vector element Lut(i) for a rough running of the engine based on at least said one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with said two vector elements Lut(i), Lut(j) being for each ignition (i); computing a spacing between said vector LUT(i) and at least one predetermined reference vector Rn and Ra; detecting a combustion misfire when said spacing satisfies a predetermined condition; and, detecting a plurality of time spans ts(i) and directly supplying a criterion for rough running and forming the vector LUT(i) as: LUT(i)=(ts(i), ts(i+1), . . . , ts(z-1)) wherein: (z)=number of cylinders of the engine.
Claim 14
Independent Claim
160 words
A method for detecting combustion misfires in a multicylinder internal combustion engine, the method comprising the steps of: detecting a time span ts(i) in which the crankshaft of the engine passes through a pregiven angular range (φ) for each ignition of the engine; computing a vector element Lut(i) for a rough running of the engine based on at least said one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with said two vector elements Lut(i), Lut(j) being for each ignition (i); computing a spacing between said vector LUT(i) and at least one predetermined reference vector Rn and Ra; detecting a combustion misfire when said spacing satisfies a predetermined condition; and, detecting a plurality of time spans ts(i) and directly supplying a criterion for rough running and forming the vector LUT(i) as: LUT(i)=(ts(i), ts(i+1), . . . , ts(z-1)) wherein: (z)=number of cylinders of the engine.
Claim 15
Independent Claim
157 words
A method for detecting combustion misfires in a multicylinder internal combustion engine, the method comprising the steps of: detecting time spans ts(i) in which the crankshaft of the engine passes through a pregiven angular range (φ) for each ignition of the engine; computing a vector element Lut(i) for a rough running of the engine based on at least said one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with said two vector elements Lut(i), Lut(j) being for each ignition (i); computing a spacing between said vector LUT(i) and at least one predetermined reference vector Rn and Ra; detecting a combustion misfire when said spacing satisfies a predetermined condition; forming differences of said time spans ts(i) as a criterion for the rough running; and, forming the vector LUT(i) as LUT(i)=(ts(i+1)-ts(i), ts(i+z)-ts(i+1), . . . , ts(i+z-1)-ts(i+z-2)) wherein: (z)=number of cylinders of the engine.
Claim 16
Independent Claim
157 words
A method for detecting combustion misfires in a multicylinder internal combustion engine, the method comprising the steps of: detecting time spans ts(i) in which the crankshaft of the engine passes through a pregiven angular range (φ) for each ignition of the engine; computing a vector element Lut(i) for a rough running of the engine based on at least said one detected time span ts(i) for each ignition (i) of the engine; forming a vector LUT(i) from at least two vector elements Lut(i), Lut(j) with said two vector elements Lut(i), Lut(j) being for each ignition (i); computing a spacing between said vector LUT(i) and at least one predetermined reference vector Rn and Ra; detecting a combustion misfire when said spacing satisfies a predetermined condition; forming differences of said time spans ts(i) as a criterion for the rough running; and, forming the vector LUT(i) as LUT(i)=(ts(i+1)-ts(i), ts(i+z)-ts(i+1), . . . , ts(i+z-1)-ts(i+z-2)) wherein: (z)=number of cylinders of the engine.
Claim 17
Dependent Claim
25 words
The method of claim 5, wherein the vector LUT(i) is formed as: ##EQU8## wherein: (z)=number of cylinders of the internal combustion engine; and, (p)=fixed value.
Claim 18
Dependent Claim
31 words
The method of claim 9, comprising the step of utilizing times (ts(i+j))/(ts(i)), which are standardized to ts(i), in lieu of the differences ts(i+j)-ts(i+j-1) wherein j=1, 2, . . . , z.
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