Abstract
A multi-cylinder gasoline HCCI engine system is developed, which satisfies fuel economy and low emissions requirements. One of the main problems with the gasoline HCCI engine system is developing a method to switch between SI and HCCI combustion modes. In this study, the optimal in-cylinder gas behavior during combustion mode switching is investigated by using an engine cycle simulator. As a result, transient control of the amount of intake air is important to maintain combustion stability, and a method for controlling it optimally is developed. In addition, as judged from the experimental results, our method is demonstrated to be valid for switching from HCCI combustion to SI combustion without torque variations.
