Noise existence diagnosis device for fuel injection system

• Main Author: KOMATSU KOU
• Format: Patent
• Language: English
• Published: 02.07.2013
• Subjects: BLASTING; CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TOTRANSPORTATION; COMBUSTION ENGINES; CONTROLLING COMBUSTION ENGINES; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; LIGHTING; MEASURING; MECHANICAL ENGINEERING; PHYSICS; SUPPLYING COMBUSTION ENGINES IN GENERAL, WITH COMBUSTIBLEMIXTURES OR CONSTITUENTS THEREOF; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TESTING; TESTING STATIC OR DYNAMIC BALANCE OF MACHINES ORSTRUCTURES; TESTING STRUCTURES OR APPARATUS NOT OTHERWISE PROVIDED FOR; WEAPONS

A waveform detector detects a variation in fuel pressure generated by an injection based on a detection value of a fuel pressure sensor as a fuel pressure waveform. A differential calculator calculates a differential waveform representing a variation in differential value of the fuel pressure waveform. A noise determiner determines that noise overlaps with the fuel pressure waveform when the differential waveform has a value higher than a predetermined upper threshold or when the differential waveform has a value lower than a predetermined lower threshold.