Exact air charge feed forward control of a turbocharged SI engine

Abstract

In this work, a MIMO feed forward control for the air charge, i.e. the mass of air in the cylinders of a turbo charged spark ignition (SI) engine is presented. The control inputs are the angle of the throttle plate and the opening of the wastegate. There are many publications in this field of application. Often the control task is separated into an air charge control with the throttle plate as control input and a boost pressure control with the wastegate opening as control input. These approaches often lack the ability to precisely track reference trajectories in the transition between suction mode operation and turbocharged operation. The approach presented here is based on exact input-output linearization and enables a perfect tracking of air charge reference trajectories in both modes of operation and the transition between them.