Air-fuel ratio fuzzy controller handling delay: Comparison with a PI/Smith

This paper is dedicated to the control of the air-fuel ratio in a gasoline engine. The use of the crank-angle domain handles the variable transport delay, which is the main challenge when controlling air-fuel ratio. The Takagi-Sugeno methodology is considered to deal with the nonlinearities in the model. The control law is obtained using an extended state that includes the delayed variables. Simulations confirm the feasibility of the method and highlight the efficiency of the proposed air-fuel ratio controller.

I. Introduction

Due to the increasing number of cars, dealing with the exhaust gases is a crucial issue. Car industries are constrained by norms that are becoming tougher and tougher. That is why the currently implemented static look-up tables that are currently implemented in the electronic control units should be replaced by a closed-loop controller.