Accurate dynamic modeling of an electronically controlled CNG injection system

Compressed natural gas engines provide a non-standard solution for reducing emission of polluting gases and particulate matter. However, the gas compressibility and the complex nonlinear fluid-dynamics make the task of metering the air-gas mixture very difficult. To address this issue and to synthesize effective strategies for controlling the common rail pressure, it is necessary to develop an accurate control-oriented model that describes the relevant components, processes and dynamics. This paper presents a model-based approach that can be used for prediction, analysis of performance and control design. The developed model is validated by comparison of simulation results with experimental data from a real injection system.