Stefanopoulou Over the last two decades there has been a significant evolution in powertrain control systems, largely driven by government regulations aimed at improving fuel economy and reducing emissions. One way to potentially meet these performance requirements is to optimize the exhaust and intake valve motion in a spark ignited engine. The additional actuation can be realized with a camless valvetrain and results in a nonlinear and highly multivariable engine.
The proposed project is a combination of research in the area of engine modeling and multivariable control. We will develop a phenomenological model for the nonlinear and multivariable engine by characterizing the essential modifications that variable valve motion introduces in the structure of the conventional engine model. The developed model is intended to fill the gap between the analytical thermodynamic engine models and the steady-state engine models that are currently used for studying camless engines. We will identify the inherent system limitations as they arise from fundamentallly discrete plant properties, subsystem interactions and contstraints imposed by sensor/actuator fidelity/authority. A rigorous methodology of translating the system limitations to performance tradeoffs and their implication to the control design parameters will be developed. Finally, we will study the impact of controller architecture on the engine dynamie response. Our intent is to improve the understanding of the possible detrimental consequences of subsysem interaction, and the potential of coordinated, multivariable feedback for alleviating these limitations.
This project will allow students to integrate various aspects of fluid, thermodynamic and systems theory for the development and the control design of the variable valve motion engine. Our pedagogical objective is to expose students to the highly interdisciplinary area of powertrain control. Students can play an important role in developing potential solutions to cleaner automobiles. Meanwhile, they will enhance their understanding in the area of multivariable feedback control theory by their active participation in the forefront of advanced engine technologies. The proposed research project and its pedagogical aspects stress cross-disciplinary involvement and combine system theoretical concepts and engineering design criteria in the analysis and synthesis of technologies important to our national competitiveness. ***
