The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 30, 2006
Filed:
Apr. 15, 2005
Satoshi Masuda, Kariya, JP;
Masaomi Inoue, Kariya, JP;
Yuichi Takemura, Anjo, JP;
Kenji Kasashima, Aichi-ken, JP;
Rihito Kaneko, Aichi-ken, JP;
Satoshi Masuda, Kariya, JP;
Masaomi Inoue, Kariya, JP;
Yuichi Takemura, Anjo, JP;
Kenji Kasashima, Aichi-ken, JP;
Rihito Kaneko, Aichi-ken, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Denso Corporation, Kariya, JP;
Abstract
An ECU obtains two data values (a peak value and a waveform correlation coefficient) that show the characteristics of a knock from the output of a knock sensor. The ECO approximately obtains the mean of each data value by smoothing each data value, and approximately obtains a variance by smoothing the squared deviation between the data values before and after the smoothing process. The ECU then computes the square root of the variance to approximately obtain a standard deviation. The ECU normalizes each data value using the mean and the standard deviation, obtains a distribution of the normalized two data values, and calculates a correlation coefficient that shows the correlation between the obtained distribution and an ideal knock distribution. Based on the correlation coefficient, the ECU corrects a knock determination threshold value. Therefore, the mean and the standard deviation of the data values are computed with a small RAM capacity.