Air/fuel ratio control system for internal combustion engine controls ratios of various cylinders, mean ratio to set measured ratio to desired ratio by correcting injection, exhaust feedback

摘要

The system has an air/fuel ratio measurement device for the exhaust from multiple cylinders and an exhaust gas feedback unit for feeding some gas back to the engine inlet channel. A controller controls the ratios of the various cylinders and the mean ratio so that the measured ratio is set to a desired ratio by correcting an injection or exhaust feedback quantity. The system has an air/fuel ratio measurement device for the exhaust from multiple cylinders and an exhaust gas feedback unit for feeding some gas back to the engine inlet channel. A ratio computation device derives a ratio from the engine's instantaneous operating state. A first characteristic value per cylinder and a mean ratio are derived from the measured ratio and a controller controls the ratios of the various cylinders and the mean ratio so that the measured ratio is set to a desired ratio by correcting an injection or exhaust feedback quantity.