US4584869A
Expired / Lapsed
US
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Method and apparatus for detecting knock in a spark ignition engine
Assignee: TM ANALYTIC Inc AN IL CORP
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Filing: 1983-08-12
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Granted: 1986-04-29
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Expires: 2003-08-12
Abstract
Abstract Transducers 16 detect local vibration of the engine and the signals therefrom can be compared using coherence or correlation functions in the region of the knock frequency to ascertain if the source of the vibrations is the same, indicating knock, or different, indicating random vibration. Two transducers spaced apart can be used, or one can measure cylinder pressure. Alternatively, one sensor could be used, using two signals delayed with respect to each other in time.
Inventors
- 👤 John S. Frodsham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:05
CPC Classifications
F; F02; F02P; F02P5/00; F02P5/04; F02P5/145; F02P5/15; F02P5/152; G; G01; G01L; G01L23/00; G01L23/22; G01L23/221; G01L23/225; F02B; F02B1/00; F02B1/02; F02B1/04; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/40
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
110 words
A method of detecting knock in a spark ignitiion internal combustion engine, wherein two signals derived from the vibration of the engine and/or pressure in a cylinder are compared with each other in a bandwidth which includes the knock frequency to ascertain whether they arise from the same or different sources, the two signals are derived from the same sensor but one is time delayed compared to the other, the signals are compared using an auto-correlation function, and the average of the instantaneous product of the two signals is calculated for a series of different delays between the signals, to obtain the auto-correlation function as a function of time lag.
Claim 2
Independent Claim
110 words
A method of detecting knock in a spark ignitiion internal combustion engine, wherein two signals derived from the vibration of the engine and/or pressure in a cylinder are compared with each other in a bandwidth which includes the knock frequency to ascertain whether they arise from the same or different sources, the two signals are derived from the same sensor but one is time delayed compared to the other, the signals are compared using an auto-correlation function, and the average of the instantaneous product of the two signals is calculated for a series of different delays between the signals, to obtain the auto-correlation function as a function of time lag.
Claim 3
Dependent Claim
24 words
A method as claimed in claim 1, wherein the ignition timing is regulated to reduce knock in dependence on the comparison of the signals.
Claim 4
Independent Claim
120 words
A method of detecting knock in a spark ignition internal combustion engine, wherein two signals derived from the vibration of the engine and/or pressure in a cylinder are compared with each other in a bandwidth which includes the knock frequency to ascertain whether they arise from the same or different sources, the two signals are derived from different sensors spaced apart from each other, the two signals are compared using a cross correlation function, and the average of the instantaneous product of the signal from one sensor and that from the other but delayed by a lag time, is calculated for a series of different delays between the signals, to obtain the cross-correlation function as a function of lag time.
Claim 5
Independent Claim
120 words
A method of detecting knock in a spark ignition internal combustion engine, wherein two signals derived from the vibration of the engine and/or pressure in a cylinder are compared with each other in a bandwidth which includes the knock frequency to ascertain whether they arise from the same or different sources, the two signals are derived from different sensors spaced apart from each other, the two signals are compared using a cross correlation function, and the average of the instantaneous product of the signal from one sensor and that from the other but delayed by a lag time, is calculated for a series of different delays between the signals, to obtain the cross-correlation function as a function of lag time.
Claim 6
Independent Claim
74 words
A method of detecting knock in a spark ignition internal combustion engine, wherein two signals derived from the vibration of the engine and/or pressure in a cylinder are compared with each other in a bandwidth which includes the knock frequency to ascertain whether they arise from the same or different sources, the two signals are derived from different sensors spaced apart from each other, the two signals are compared using a cross-spectral density function.
Claim 7
Independent Claim
74 words
A method of detecting knock in a spark ignition internal combustion engine, wherein two signals derived from the vibration of the engine and/or pressure in a cylinder are compared with each other in a bandwidth which includes the knock frequency to ascertain whether they arise from the same or different sources, the two signals are derived from different sensors spaced apart from each other, the two signals are compared using a cross-spectral density function.
Claim 8
Dependent Claim
51 words
A method as claimed in claim 4, wherein the average of the instantaneous product of the Fourier transform of one signal over a given period and the complex conjugate of the Fourier transform of the other signal over a given period is calculated over a series of successive periods of time.
Claim 9
Independent Claim
76 words
A method of detecting knock in a spark ignition internal combustion engine, said method comprising sensing the vibration of the engine or pressure in a cylinder by means of a sensor, and obtaining the auto-correlation function of a signal derived from the sensor, the auto-correlation function being the average of the instantaneous product of the signal and the signal delayed by a time lag as a function of time lag, to detect the presence of knock.
Claim 10
Independent Claim
76 words
A method of detecting knock in a spark ignition internal combustion engine, said method comprising sensing the vibration of the engine or pressure in a cylinder by means of a sensor, and obtaining the auto-correlation function of a signal derived from the sensor, the auto-correlation function being the average of the instantaneous product of the signal and the signal delayed by a time lag as a function of time lag, to detect the presence of knock.
Claim 11
Independent Claim
49 words
A method of detecting knock in a spark ignition internal combustion engine, said method comprising sensing the vibration of the engine or pressure in a cylinder by means of a sensor, and obtaining the auto-spectral density of a signal derived from the sensor, to detect the presence of knock.
Claim 12
Independent Claim
49 words
A method of detecting knock in a spark ignition internal combustion engine, said method comprising sensing the vibration of the engine or pressure in a cylinder by means of a sensor, and obtaining the auto-spectral density of a signal derived from the sensor, to detect the presence of knock.
Claim 13
Independent Claim
90 words
A method of detecting knock in a spark ignition internal combustion engine, said method comprising sensing the vibration of the engine or pressure in a cylinder by means of two sensors spaced apart from each other, and obtaining the cross-correlation function of signals derived from the two sensors, the cross-correlation function being the average of the instantaneous product of the signal from one sensor and that from the other sensor but delayed by a time lag as a function of time lag in order to detect the onset of knock.
Claim 14
Independent Claim
90 words
A method of detecting knock in a spark ignition internal combustion engine, said method comprising sensing the vibration of the engine or pressure in a cylinder by means of two sensors spaced apart from each other, and obtaining the cross-correlation function of signals derived from the two sensors, the cross-correlation function being the average of the instantaneous product of the signal from one sensor and that from the other sensor but delayed by a time lag as a function of time lag in order to detect the onset of knock.
Claim 15
Independent Claim
57 words
A method of detecting knock in a spark ignition internal combustion engine, said method comprising sensing the vibration of the engine or pressure in a cylinder by means of two sensors spaced apart from each other, and obtaining the cross-spectral density function of the signals derived from the sensors, in order to detect the onset of knock.
Claim 16
Independent Claim
57 words
A method of detecting knock in a spark ignition internal combustion engine, said method comprising sensing the vibration of the engine or pressure in a cylinder by means of two sensors spaced apart from each other, and obtaining the cross-spectral density function of the signals derived from the sensors, in order to detect the onset of knock.
Claim 17
Dependent Claim
56 words
A method according to claim 9, wherein the cross-spectral density function is calculated by calculating the average of the instantaneous product of the Fourier transform of one signal over a given period and the complex conjugate of the Fourier transform of the other signal over a given period over a series of successive periods of time.
Claim 18
Dependent Claim
84 words
The combination comprising a spark ignition internal combustion engine and an apparatus for detecting knock in said internal combustion engine, said apparatus comprising a sensor for sensing the vibration of the engine or pressure in a cylinder, and means for obtaining the auto-correlation function of a signal derived from the sensor, the auto-correlation function being the average of the instantaneous product of the signal and the signal delayed by a time lag as a function of time lag to detect the presence of knock.
Claim 19
Dependent Claim
84 words
The combination comprising a spark ignition internal combustion engine and an apparatus for detecting knock in said internal combustion engine, said apparatus comprising a sensor for sensing the vibration of the engine or pressure in a cylinder, and means for obtaining the auto-correlation function of a signal derived from the sensor, the auto-correlation function being the average of the instantaneous product of the signal and the signal delayed by a time lag as a function of time lag to detect the presence of knock.
Claim 20
Dependent Claim
57 words
The combination comprising a spark ignition internal combustion engine and an apparatus for detecting knock in said internal combustion engine, said apparatus comprising a sensor for sensing the vibration of the engine or pressure in a cylinder, and means for obtaining the auto-spectral density of a signal derived from the sensor, to detect the presence of knock.
Claim 21
Dependent Claim
57 words
The combination comprising a spark ignition internal combustion engine and an apparatus for detecting knock in said internal combustion engine, said apparatus comprising a sensor for sensing the vibration of the engine or pressure in a cylinder, and means for obtaining the auto-spectral density of a signal derived from the sensor, to detect the presence of knock.
Claim 22
Dependent Claim
98 words
The combination comprising a spark ignition internal combustion engine and an apparatus for detecting knock in said internal combustion engine, said apparatus comprising two sensors spaced apart from each other for sensing the vibration of the engine or pressure in a cylinder, and means for obtaining the cross-correlation function of signals derived from the two sensors, the cross-correlation function being the average of the instantaneous product of the signal from one sensor and that from the other sensor but delayed by a time lag as a function of time lag in order to detect the onset of knock.
Claim 23
Dependent Claim
98 words
The combination comprising a spark ignition internal combustion engine and an apparatus for detecting knock in said internal combustion engine, said apparatus comprising two sensors spaced apart from each other for sensing the vibration of the engine or pressure in a cylinder, and means for obtaining the cross-correlation function of signals derived from the two sensors, the cross-correlation function being the average of the instantaneous product of the signal from one sensor and that from the other sensor but delayed by a time lag as a function of time lag in order to detect the onset of knock.
Claim 24
Dependent Claim
64 words
The combination comprising a spark ignition internal combustion engine and an apparatus for detecting knock in said internal combustion engine, said apparatus comprising two sensors spaced apart from each other for sensing the vibration of the engine pressure in a cylinder, and means for obtaining the cross-spectral density function of the signals derived from the sensors, in order to detect the onset of knock.
Claim 25
Dependent Claim
64 words
The combination comprising a spark ignition internal combustion engine and an apparatus for detecting knock in said internal combustion engine, said apparatus comprising two sensors spaced apart from each other for sensing the vibration of the engine pressure in a cylinder, and means for obtaining the cross-spectral density function of the signals derived from the sensors, in order to detect the onset of knock.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-04-28 | 1989-10-28 | 1990-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-28 | 1993-10-28 | 1994-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-28 | 1997-10-28 | 1998-04-29 | $7700.00 | Window Closed / Lapsed |