MAXIMUM VALUE DETECTION METHOD FOR SENSOR SIGNAL, SENSOR SIGNAL PROCESSING DEVICE, AND KNOCK DETECTION METHOD FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To accurately detect the maximum value of oscillation with respect to the vibration center level of a sensor signal which is a vibration wave, without influence from noise and regardless of the length of detection time. ;SOLUTION: An engine control ECU, which inputs a sensor signal from a knock sensor between a knock judgment interval and which detects the maximum value of oscillation with respect to the vibration center level (reference level) of that signal, integrates the oscillation with respect to the reference value of the sensor signal every half wave time T minute of the sensor signal while calculating the average value AVR in which each of those integral values are divided by the continuous time of the half wave time T, respectively. Then, a maximum average value AVRmax is selected from among each average value AVR and the maximum value of oscillation is calculated from those maximum average values AVRmax. This ECU enables accurate detection of the above-mentioned maximum value of oscillation without being influenced from noise and regardless of the length of the knock judgment interval because of the integration and averaging every half wave time T minute.;COPYRIGHT: (C)1999,JPO