KNOCKING DETECTOR FOR INTERNAL-COMBUSTION ENGINE

摘要

PURPOSE:To conduct highly accurate detection by deciding whether knocking is present or not based on a background level corresponding to a filter signal and providing means for updating and enlarging the background level. CONSTITUTION:A background level operating section 52 determines a background level by averaging the peak values received from a peak hold section 51 for a predetermined number of times of firing cycle. A predetermined update amount DELTAV is then added to or subtracted from the background level to produce an updated background level which is delivered to a decision level calculating section 5 and stored. The operating section 52 repeats the ground level updating operation for the variation in the operating state of engine in cooperation with a gradual variation table 53 and an update amount calculating section 54. The update amount AV is controlled to increase for a predetermined interval corresponding to an initial set value and then decrease gradually thus making a quick transition to a level for allowing correct decision of the presence of knocking.