Integrated HCCI Engine Control Based on a Performance Index

Integrated control of HCCI combustion phasing, load, and exhaust aftertreatment system is essential for realizing high efficiency HCCI engines, while maintaining low HC and CO emissions. This paper introduces a new approach for integrated HCCI engine control by defining a novel performance index to characterize different HCCI operating regions. The experimental data from a single cylinder engine at 214 operating conditions is used to determine the performance index for a blended fuel HCCI engine. The new performance index is then used to design an optimum reference trajectory for a multi-input multi-output HCCI controller. The optimum trajectory is designed for control of combustion phasing and IMEP, while meeting catalyst light-off requirements for the exhaust aftertreatment system. The designed controller is tested on a previously validated physical HCCI engine model. The simulation results illustrate the successful application of the new approach for controller design of HCCI engines.