Sliding Mode Air-to-Fuel Ratio Control of Spark Ignition Engines in Comprehensive Powertrain System

This paper's results are presented on the advantages of employing the sliding mode controller for air-to-fuel ratio (AFR) control over comparisons to the proportional-integral-derivative (PID) controller. The three biggest advantages of this controller are: (1) its ability to consider performance issues in the presence of noise, disturbance, and parameter uncertainty, (2) its consistency with nature of oxygen sensor which is binary, and (3) its satisfactory performance for all operating conditions. In this paper, performance evaluations are performed on a thorough powertrain model including engine model, automatic transmission, driveline, and longitudinal vehicle dynamics. Adding some actuators and sensors model such as injector, electric throttle, oxygen sensor, and vehicle speed sensor makes the model more realistic. Moreover, approaching real conditions, noise, disturbance, and parameter uncertainty are considered in control systems. It's worth mentioning that in this study, the AFR control is performed in the new European driving cycle (NEDC).