Knock recognition in internal combustion engines with modifications by changing filter characteristics or cylinder specific changes

• Main Authors: Franke, Steffen, Sauler, Juergen, Unland, Stefan, Torno, Oskar, Heinstein, Axel, Kluth, Carsten, Haeming, Werner, Baeuerle, Michael
• Format: Patent
• Language: English
• Published: 12.02.2004

Devices and methods for knock detection and knock control are described, in which, in addition to the customary component parts, the knock-detection circuit has a filter with switchable filter characteristic. The switchover of the filter characteristic, i.e. the shift, for example, of the mid-frequency of the filter, is carried out taking into consideration specifiable quantities or parameters, for instance, as a function of rotational speed. During the switchover of the filter characteristic, i.e. the shift of the mid-frequency, problems could occur in the knock detection; that is why measures are proposed which carry out the knock detection according to a special knock-detection algorithm during a switchover phase lasting a specifiable time.