Investigation about Simple Adaptive Control Application for Air Fuel Ratio Control at Transient State

Abstract

The regulation about emission purification and fuel consumption of an automobile becomes increasingly strict for environmental issue. Especially, the performance while transient state is focused on because transient state was increased in the new JC08 emission test-mode. Emission purification of the gasoline engine is attained both using a three way catalyst and controlling air fuel ratio(AFR) by means of an oxygen sensor while steady state. However, while transient state, AFR is deteriorated because of non-linear character such as a fuel wall-wet flow balance, allowance of each engine, aging and ambient of operation. Therefore, highly performed controller is necessary for AFR control at transient state. In this paper, an application of simple adaptive control(SAC) is investigated for AFR regulate control to compensate a disturbance affection at transient state. SAC has two degrees freedom system that was consist of both a feed forward tracker and a feedback stabilizer. Then, SAC control the time response of a plant to agree with that of a reference model. However, there were few report that SAC was applied as a regulator to overcome a disturbance. This paper investigated the control system to apply SAC for AFR regulate control at transient state. Then, the experiment were carried out at different operating condition, and the results showed a good regulating performance as a transient state regulator.