Model-Guided Data-Driven Optimization and Control for Internal Combustion Engine Systems

The incorporation of electronic components into modern Internal Combustion, IC, engine systems have facilitated the reduction of fuel consumption and emission from IC engine operations. As more mechanical functions are being replaced by electric or electronic devices, the IC engine systems are becoming more complex in structure. Sophisticated control strategies are called in to help the engine systems meet the drivability demands and to comply with the emission regulations. Different model-based or data-driven algorithms have been applied to the optimization and control of IC engine systems. For the conventional model-based algorithms, the accuracy of the applied system models has a crucial impact on the quality of the feedback system performance. With computable analytic solutions and a good estimation of the real physical processes, the model-based control embedded systems are able to achieve good transient performances. However, the analytic solutions of some nonlinear models are difficult to obtain. Even if the solutions are available, because of the presence of unavoidable modeling uncertainties, the model-based controllers are designed conservatively

CLEAN COMBUSTION CONTROL IN A COMPRESSION IGNITION ENGINE

The primary objective of this dissertation is to develop combustion control strategies, that can reduce the thermal efficiency penalty associated with clean combustion in modern compression ignition engines. The clean combustion targets of simultaneously low oxides of nitrogen (NOX) and smoke emissions are selected as the platforms for demonstrating the dynamic control strategies on a single cylinder research engine. First, parametric analyses, including exhaust gas recirculation (EGR) calculations, are performed using a zero-dimensional engine cycle simulation model. Thereafter, two combustion strategies are experimentally investigated, namely the single-shot diesel strategy and the dual-fuel strategy. The single-shot diesel combustion strategy employs a single direct injection of diesel with the use of moderate levels of EGR. In the dual-fuel combustion strategy, port injection of ethanol is utilized in addition to the direct injection of diesel and the application of EGR. The results of parametric analyses and engine experiments provide guidelines for the development of a systematic control strategy. Closed-loop combustion control systems are implemented for regulating the fuel injection commands, by which the combustion phasing is effectively controlled on a cycle-by-cycle basis in both the diesel and dual-fuel combustion strategies. The fuel injection control is integrated into the systematic control strategy for simultaneously controlling the air and fuel systems. The intake boost pressures, EGR rates, and fuelling strategies are dynamically selected, depending on the engine load level. By implementing the systematic control, both the NOX and smoke targets are achieved over a wide engine load range, while retaining the thermal efficiency of conventional diesel combustion