Knock signal detection in automotive systems
First Claim
1. A system for detecting knock signals in an internal combustion engine, comprising:
- a sensor structure operatively coupled to the internal combustion engine for generating sensor signal information in response to engine vibrations; and
a signal processing structure operatively coupled to the sensor structure for extracting digital signal information from the sensor signal information to identify a predetermined pitch frequency and any short-term energy increase in the digital signal information which in combination are used to generate a knock detection signal.
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Abstract
In an automotive system (300), a knock detection scheme is provided for detecting knock events in an internal combustion engine that are sensed by a transducer structure, such as a non-intrusive acoustic accelerometer sensor (310) to generate sensor signal information which is processed by a signal processing structure (312, 316, 318, 326) which extracts digital signal parameters from the sensor signal information to identify a predetermined pitch frequency (330) and any short-term energy increase (328) in the digital signal information which in combination are used to provide a positive indication of engine knock behavior. When a short term Fourier transform (324) is used to extract the digital signal parameters, time frequency resolution may be improved by appropriately windowing the digital signal being transformed.
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Citations
20 Claims
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1. A system for detecting knock signals in an internal combustion engine, comprising:
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a sensor structure operatively coupled to the internal combustion engine for generating sensor signal information in response to engine vibrations; and a signal processing structure operatively coupled to the sensor structure for extracting digital signal information from the sensor signal information to identify a predetermined pitch frequency and any short-term energy increase in the digital signal information which in combination are used to generate a knock detection signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for obtaining engine knock data from an internal combustion engine, comprising:
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acquiring analog vibration signal information from a cylinder in the internal combustion engine using a knock sensor; processing the analog vibration signal information by frame to generate an anti-aliased, down-sampled digital time domain signal; short term Fourier transforming the digital time domain signal into a digital frequency domain signal, thereby generating instantaneous frequency and amplitude information for each frame; detecting a predetermined pitch frequency in a frame from the instantaneous frequency and amplitude information; detecting a predetermined energy increase in a frame from the instantaneous frequency and amplitude information; and generating an engine knock detection signal if both the predetermined pitch frequency is detected and if the predetermined energy increase is detected. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A method of detecting engine knocks, comprising:
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generating an analog sensor signal from an accelerometer which senses engine vibrations; and extracting by frame a digital signal from the analog sensor signal to identify a predetermined pitch frequency and any short-term energy increase in the digital signal; generating a knock detection signal if both the predetermined pitch frequency and a short-term energy increase are detected in a frame. - View Dependent Claims (17, 18, 19, 20)
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Specification