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Internal Model Control (IMC) has a great appeal for automotive powertrain control in reducing the control design and calibration effort. Motivated by its success in several automotive applications, this work investigates the design of nonlinear IMC for wastegate control of a turbocharged gasoline engine. The IMC design for linear time-invariant (LTI) systems is extended to nonlinear systems. To leverage the available tools for LTI IMC design, the quasi-linear parameter-varying (quasi-LPV) models are explored. IMC design through transfer function inverse of the quasi-LPV model is ruled out due to parameter variability. A new approach for nonlinear inversion, referred to as the structured quasi-LPV model inverse, is developed and validated. A fourth-order nonlinear model which sufficiently describes the dynamic behavior of the turbocharged engine is used as the design model in the IMC structure. The controller based on structured quasi-LPV model inverse is designed to achieve boost-pressure tracking. Finally, simulations on a validated high-fidelity model are carried out to show the feasibility of the proposed IMC. Its closed-loop performances are compared with a well-tuned PI controller with extensive feedforward and anti-windup built in. Robustness of the nonlinear IMC design is analyzed using simulations. [ABSTRACT FROM AUTHOR]

HEV (hybrid electric vehicles, HEV) is considered to be one of the most important automotive technical roadmaps. Fuel efficiency level of the engine used in HEV has significant impact on vehicle fuel consumption. This paper studies the performance and fuel economy potential of applying high GCR (geometrical compression ratio, GCR) and cooled EGR in turbocharged gasoline SI engines dedicated to the use in HEVs. A 1-D simulation model for a turbocharged EGR engine has been established based on a baseline 1.5T engine. Then the effects of cooled EGR and higher GCRs on engine combustion and performance have been studied and optimized. As increasing GCR from 9.7:1 to higher values that are 12.5:1 and 14:1, the full load torque decreases obviously with the maximal relative decrease of 7.6% and 21.9% respectively mainly because EGR is used to suppress the knock reducing the volumetric efficiency. The fuel economy in the most speed and load range is greatly improved mainly because of higher constant volume degree, combustion efficiency and less heat transfer and exhaust losses. In HEVs, engines mainly work in the efficient operating range, the torque reduction can be compensated by drive motor, and an appropriately high GCR is advantageous. • 1-D simulation model of turbocharged EGR engine is built. • Variables optimization and turbocharger recalibration are conducted. • Effects of high compression ratio and cooled EGR on combustion are analyzed. • Greatly better fuel economy for turbocharged EGR engine is achieved. • Guidance for development of new dedicated engine for the use in HEV. [ABSTRACT FROM AUTHOR]

In the upcoming years, more challenging CO2 emission targets along with the introduction of more severe Real Driving Emissions limits are expected to foster the development and the exploitation of innovative technologies to further improve the efficiency of automotive Spark Ignition (SI) engines. Among these technologies, Water Injection (WI), thanks to its knock mitigation capabilities, can represent a valuable solution, although it may significantly increase the complexity of engine design and calibration. Since, to tackle such a complexity, reliable virtual development tools seem to be mandatory, this paper aims to describe a quasi-dimensional approach to model a Port Water Injection (PWI) system integrated in a Turbocharged Direct Injection Spark Ignition (T-DISI) engine. Through a port-puddling model calibrated with 3D-CFD data, the proposed methodology was proven to be able to properly replicate transient phenomena of water wall film formation, catching cycle by cycle the amount of water that enters into the cylinder and is therefore available for knock mitigation. Moreover, when compared with experimental measurements under steady state operating conditions, this method showed good capabilities to predict the impact of the water content on the combustion process and on the knock occurrence likelihood. [ABSTRACT FROM AUTHOR]