DEVICE FOR CALCULATING AIR FUEL RATIO IN EACH CYLINDER OF MULTI-CYLINDER INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To accurately calculate air fuel ratio in each cylinder by performing signal processing suitable for calculation of air fuel ratio in each cylinder. SOLUTION: Detected signal of a A/F sensor 13 is acquired by a band pass filter processing part 14 and is acquired by an air fuel ratio deviation calculation part 20 after band pass filtering by the band pass filter processing part 14. The air fuel ratio deviation calculation part 20 calculates deviation of the detected air fuel ratio calculated from sensor detection signal after band pass filtering from a target air fuel ratio established separately. The air fuel ratio deviation calculated by the air fuel ratio deviation calculation part 20 is input to an air fuel ratio in each cylinder estimation part 20 and air fuel ratio in each cylinder is estimated by the air fuel ratio in each cylinder estimation part 24. The air fuel ratio in each cylinder estimation part 24 estimates air fuel ratio for each cylinder based on detection signal of the A/F sensor 13 with using a model aiming at gas exchange at an exhaust gas collecting part 12 of an exhaust manifold 12. COPYRIGHT: (C)2006,JPO&NCIPI