| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a control apparatus for an internal combustion engine equipped with a means for ensuring temporal and frequency resolutions necessary for the analysis of a frequency of knock by digital signal processing with limited amounts of processing and a memory. Ž<P>SOLUTION: The control apparatus for an internal combustion engine includes, as knock detection means, a low pass filter 14 for eliminating a high frequency component of an output signal from a knock sensor or a cylinder internal pressure sensor, an A-D conversion unit 15 for performing A-D conversion on an output signal from the filter at each predetermined time interval, and DFT processing units 16a, 16b each performing time-frequency analysis by performing digital signal processing on data obtained by the A-D conversion, thereby detecting a knock based on the digital signal processing result by the DFT processing units. Each of the DFT processing units includes an observation interval setting means for dividing the A-D-converted data to set observation intervals each containing a predetermined number of samples, and a multi-frequency simultaneous analysis means for simultaneously analyzing multiple frequencies by a discrete Fourier transform for each of the set observation intervals. The number of samples contained in each of the observation intervals can be changed according to the frequency to be analyzed. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
