Closed-loop individual cylinder air–fuel ratio control via UEGO signal spectral analysis

• Published in: Control engineering practice Vol. 18; no. 11; pp. 1295 - 1306
• Main Authors: Cavina, Nicolò, Corti, Enrico, Moro, Davide
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier Ltd 01-11-2010; Elsevier
• Subjects: Applied sciences; Automotive systems; Control systems; Cylinders; Energy; Energy. Thermal use of fuels; Engines; Engines and turbines; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Frequency domain; Fuel injection control; Inequalities; Internal combustion engines; Internal combustion engines: gazoline engine, diesel engines, etc; Mechanical engineering. Machine design; Real time; Signal-processing algorithms; Spark ignition; Spectra; Spectral analysis; Stability; Frequency domain; Fuel injection control; Automotive systems; Signal-processing algorithms; Internal combustion engines; Spectral analysis; Harmonic; Motor car; Motor fuel injection; Control system analysis; Measurement sensor; Air fuel ratio; Frequency domain method; Real time; Real time system; Operating conditions; Closed feedback; Signal spectrum; Signal processing; Internal combustion engine; Fuel mixture; Fuel injection; Signal analysis
• ISSN: 0967-0661; 1873-6939
• DOI: 10.1016/j.conengprac.2009.12.002

The paper presents the development and real time application of an original closed-loop individual cylinder AFR control system, based on a spectral analysis of the lambda sensor signal. The observation that any type of AFR disparity between the various cylinders is reflected in a specific harmonic content of the AFR signal spectrum, represents the starting point of the project. The results observed on a 4 cylinder Spark Ignition engine are encouraging, since in the investigated engine operating conditions the controller is able to reduce AFR inequality below 0.01 lambda. The paper also shows how the proposed controller can be applied to other engine configurations.