Detecting and correcting cylinder imbalance in direct injection engines

Modern direct injection engines feature high pressure fuel injection system s that are required to control the fuel quantity very accurately. Due to li mited manufacturing accuracy these systems can benefit from an on-line adap tation scheme that compensates for injector variability. Since cylinder imb alance affects many measurable signals, different sensors and algorithms ca n be used to equalize torque production by the cylinders. This paper compar es several adaptation schemes that use different sensors. The algorithms ar e evaluated on a cylinder-by-cylinder simulation model of a direct injectio n high speed diesel engine. A proof of stability and experimental results a re reported as well.