A control oriented model of a Common-Rail System for Gasoline Direct Injection engine

Abstract

Electronics has greatly contributed to the development of internal combustion engine. This progress has resulted in reducing environmental degradation, and yet continuing to support improvements in performance. Regarding gasoline engine, a considerable step forward has been achieved by Common Rail (CR) technology able to exactly regulate the injection pressure during whole engine speed range. As a consequence, the injection of a fixed amount of fuel is more precise and it is possible to perform multiple injections for combustion cycle.In this paper, the authors present a mean value model aimed at the control of a CR system for a Gasoline Direct Injection (GDI) engine. The model is based on the descriptions of electrovalve, including the actuator circuit, and the fuel pressure in the rail. The performances of the proposed model are finally depicted through comparisons with experimental data collected by a CR system mounted on a 2.0 liters spark ignition engine, showing a good accuracy and reliability.

Research on the Common Rail Pressure Overshoot of Opposed-Piston Two-Stroke Diesel Engines

“…where the rail pressure p r and speed n were chosen as two states, and the system state equation could be obtained by: (26) Considering the coupling relationship between state variables and control variables, a corresponding transformation should be conducted on Equation (24), so the rail fuel quantity was transformed into: (27) After the transformation, the two state parameters, namely rail pressure p r and speed n were respectively written as x 1 , x 2 . The output parameter was still rail pressure p r , and it is written as y.…”

“…This method is representative fuel quantity control of common rail systems at present. Di Gaeta et al [26,27] utilized a sliding mode method to control rail pressure as well. For the purpose of stability control of rail pressure, they established a more detailed mathematical model of a common rail system.…”

An MRAC Approach for Tracking and Ripple Attenuation of the Common Rail Pressure for GDI Engines

“…In this work we have chosen from the literature the CR model proposed in di Gaeta et al (2009) that describes the pressure, p(t) (bar), in the CR as a function of the pump speed and electro-valve current, i (A), and it can be decomposed into two terms, namely, the mean pressure term,p(t) (bar) and the residual pressure, η(t) (bar), describing the ripple around the mean value. The CR dynamical system is then given by…”

“…In this paper we select as CR model the control oriented model proposed in di Gaeta et al (2009) for GDI engines Zhao et al (2002). Although this model is simpler with respect to more complex modeling approaches (see for example Balluchi et al (2006), Digesu et al (1994) and Morselli et al (2002)), it has been experimentally validated showing a good prediction of the mean-value rail pressure and a qualitative behavior of the residual pressure.…”

Injection quantity control for GDI engines

“…For example, J.Duclos [2] proposed a 3D DI-SI engine model with spray physical model for heat release prediction, applying to commercial GDI engine simulation; M.Tomforde [3] built a fuel supply system model including fuel injectors, using the model-based calibration method; E.Giakoumis [4] obtained a heavy-duty diesel engine model via the mapping-based approach and analyzed the engine performance on the European Transient Cycle; S.Kong [5] described phenomenological nozzle flow models to analyze the performance of spray models, as the fuel spray characteristics influence the combustion efficiency for both diesel and gasoline direct injection engines. For control purpose, a common rail system of gasoline direct injection engine [6] and diesel engine [7] is modeled respectively based on the descriptions of electro-valve, elementary fluid dynamics and mechanics laws.…”