An engine control system for hybrid systems

摘要

A control system that can attain a smooth drivetrain force change relative to torque set point and obtain a precise air-fuel ratio control during the change was investigated for fuel efficient hybrid systems. The hybrid systems integrate a lean burn engine with high supercharging, an exhaust gas recycle system, an electric machine for power assist, and an electronically controlled gear transmission. The engine torque and electric machine torque versus target torque, the fuel mass, air mass, exhaust gas recycle mass and the air-fuel ratio as a function of the target torque were analyzed. The estimation of air mass in a cylinder by using an air flow meter was investigated as a way to control the air-fuel ratio precisely during transients.