Requirements and Performance of Engine Management Systems under Transient Conditions

Because of the big influence on driveability and exhaust emissions one of the most important challenges of modern fuel injection systems is to ensure a very good constancy of the air/fuel ratio. A precise feedforward control especially for dynamic transitions is necessary because a feedback control of the air/fuel ratio based on an oxygen sensor in the exhaust gas is not able to avoid dynamic deviations. Therefore in this paper a new fuel injection technique is presented which is founded on a simultaneous control of air and fuel in connection with algorithms based on mathematical models of the different physical effects.