Patent ID: 6240900
Filing Date: 2001-06-05
Classification: F02P,G01L,Y02T

Abstract:
In a vehicle having an internal combustion engine, an electronic control module with memory, a plurality of sensors for generating signals in response to various vehicle dynamics, said engine including a plurality of engine cylinders, said electronic control module receiving said signals from said plurality of sensors and controlling said engine in response thereto, said plurality of sensors including a knock sensor and a position sensor, said knock sensor operable for generating a knock sensor signal indicative of a firing condition in each of said plurality of engine cylinders, said position sensor operable for generating a position sensor signal indicative of a rotational position of said engine, a method for controlling knock in said engine comprising the steps:sensing a plurality of engine conditions, the plurality of engine conditions including an engine rotational speed, an engine temperature and a manifold absolute pressure;determining whether said engine temperature is greater than a predetermined temperature;determining a maximum value of said knock sensor signal;identifying a particular cylinder which produced said maximum value;employing the engine rotational speed and a look-up table having a plurality of predetermined background noise values to determine an average level of background noise transmitted through said engine;determining a knock threshold for said particular cylinder, the knock threshold being determined from the average level of background noise and a predetermined amount based on an identity of the particular cylinder that produced the maximum value;determining if said maximum value exceeds said knock threshold;modifying a spark advance of only the particular cylinder that produced the maximum value if said maximum value exceeds said knock threshold, said engine temperature is greater than said predetermined temperature and said manifold absolute pressure is greater than a predetermined manifold absolute pressure; andotherwise, retarding said spark advance if said manifold absolute pressure is not less than said predetermined manifold absolute pressure and said engine temperature is greater than said predetermined temperature.