Integrated Simulation of the Engine and Control System of a Turbocharged Diesel Engine 2006-01-0439
Over the last decade significant efforts have been made in the automotive industry to move into a math-based control development approach where much of the development could be done off-line using computer simulations. High-fidelity simulation of an engine and control system helps to shorten controller development time with reduced risk. This requires the integration of a detailed engine model with a representative controller model.
This paper describes the development and validation of an integrated engine and controller model of a turbocharged diesel engine. The integrated model incorporates a detailed engine model in GT-Power and a comprehensive controller model in Simulink with functionalities like the production ECM. The focus of this study is a non-real time simulation and analysis of the control of EGR, turbocharger, and fueling with engine performance.
The integrated engine and controller model was extensively validated against vehicle testing data collected on a chassis dynamometer. The accuracy of the integrated model was verified using experimental measurements over five steady state conditions, three step transient conditions, and a full FTP driving cycle. It is shown that the integrated model predicted the performance of the control and engine system (such as fueling/VNT/EGR control actions, MAF, MAP, exhaust gas pressure and temperature, intake and exhaust oxygen fractions, and turbocharger shaft rotational speed) fairly well, both at steady state and at transient operating conditions.
The validated engine and controller model will be useful in the analysis and evaluation of control algorithms and control strategies. The integrated model allows engineers to develop control algorithms, explore different control strategies, study parameter sensitivities, and perform preliminary calibration before experiments are conducted or sometimes even before the hardware is built. This reduces the controller development time and cost. While this study was demonstrated on a diesel engine, the integrated modeling approach is equally applicable to gasoline engines.