Nonlinear Dynamic Model of a Turbocharged Diesel Engine

Emission regulations for diesel engines have steadily become more stringent in the past decade, and there is no indication that this trend will change. As a result, the use of electronic engine control systems will be indispensable to diesel-powered vehicles. The conventional map-based control scheme is inadequate to meet the emission requirements. A mathematical model-based control scheme for a turbocharged diesel engine, on the other hand, can improve performance in terms of power and emissions during the steady state and the transient engine operations. In this study, a dynamic model of a turbocharged common-rail direct injection diesel engine is developed for control applications. This model is composed of differential and algebraic equations, which are derived from the filling and emptying method and the quasi-steady method, respectively. The dynamic subsystems include the air intake subsystem, the exhaust subsystem, and the rotational subsystems of the turbocharger and crankshaft. The compressor and the turbine models of a turbocharger are obtained based on the empirical data from the manufacturer. The developed engine model is evaluated through engine tests.