Integrated HCCI Engine Control Based on a Performance Index

Abstract

The integrated control of a homogenous charge compression ignition (HCCI) combustion phasing, load, and exhaust aftertreatment system is essential for realizing highefficient HCCI engines, while maintaining low hydrocarbon (HC) and carbon monoxide (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 multiinput multioutput HCCI controller. The optimum trajectory is designed for control of the combustion phasing and indicated mean effective pressure (IMEP), while meeting catalyst lightoff 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.