Development of GT-Power Model of a Gasoline Engine with Low Pressure EGR Suitable for Model-Based Predictive Control of an Air Path

Abstract

To develop an engine complying emission limits, reduce fuel consumption and enhance engine power output is a car manufacture’s task of the last years. New emission limits make this task even more challenging and to fulfil them requires new approaches. Recirculation of burned gases is promising way how to reduce harmful emissions and improve fuel consumption in case of a spark ignition engine. Introduction of EGR system increase degrees of freedom and it makes engine control more and more complex. To be able to use potential of EGR fully requires to have a precise calibration. Increasing need of precise calibration and higher amount of degrees of freedom increase time demand for Engine management system calibration and validation. If the calibration and validation would be performed on engine test bench only, it would be lengthy and costly. For this reason, simulation software is used to lower time demand on a test bench for engine management system calibration and validation. Aim of this work is to create models of spark ignition engine to support Model predictive control (MPC) development. Models are needed in two levels of accuracy. Trend models are part of MPC development where appropriate MPC is selected. Detailed model is needed for MPC validation before implementation of MPC on real engine application. This work explains which models are needed and what are their role in validation process. It also describes how the models have been created and which data is needed.

To develop an engine complying emission limits, reduce fuel consumption and enhance engine power output is a car manufacture’s task of the last years. New emission limits make this task even more challenging and to fulfil them requires new approaches. Recirculation of burned gases is promising way how to reduce harmful emissions and improve fuel consumption in case of a spark ignition engine. Introduction of EGR system increase degrees of freedom and it makes engine control more and more complex. To be able to use potential of EGR fully requires to have a precise calibration. Increasing need of precise calibration and higher amount of degrees of freedom increase time demand for Engine management system calibration and validation. If the calibration and validation would be performed on engine test bench only, it would be lengthy and costly. For this reason, simulation software is used to lower time demand on a test bench for engine management system calibration and validation. Aim of this work is to create models of spark ignition engine to support Model predictive control (MPC) development. Models are needed in two levels of accuracy. Trend models are part of MPC development where appropriate MPC is selected. Detailed model is needed for MPC validation before implementation of MPC on real engine application. This work explains which models are needed and what are their role in validation process. It also describes how the models have been created and which data is needed.