Optimal control of HCCI

HCCI (Homogeneous Charge Compression Ignition) is a very control-intensive combustion concept which has been studied for over a decade because of its favorable combination of high efficiency and low emissions. Various optimal control methods have been applied to HCCI and this chapter gives an overview of them. Optimal control of HCCI can be divided into model based and non-model based where MPC is an example of model based and extremum seeking control is an example of non-model based control. The model-based methods can be divided based on whether they use physics based or black box models. Finally a division can be made based on whether the control aims for optimal set-point tracking of e.g. combustion timing or whether it attempts to optimize an overall design criterion such as fuel consumption. This chapter presents and characterizes a number of published methods for optimal HCCI control and characterizes them according to the above criteria