Algorithm development on the use of feedback signals in the context of gasoline HCCI combustion

Homogeneous Charge Compression Ignition (HCCI) combustion is a promising research subject due to its characteristics of high efficiency and low emissions. These are highly desirable, given the global picture of increased energy requirements coupled with serious environmental implications. However, one of the main considerations of HCCI implementation is its control strategies which are not straightforward as in conventional Spark Ignition (SI) or Compression Ignition (Cl) engines. In order for closed loop control strategies to be successful, appropriate signals must be selected. In this research, experimental in-cylinder signals have been collected for pressure and ion current. These have been processed and evaluated as regards their suitability for HCCI control. During this process, physical based models have been developed both for treating experimental data as well as simulating theoretical cases. Using these tools, the behaviour of unstable HCCI operation has also been explored.