The aim of this work is the development of a strategy for the control of low temperature combustions. The strategy was developed and validated using a compression ignition engine run in RCCI mode.
The selected injection pattern, characterized by a gasoline/diesel target ratio equal to 80/20, allows obtaining a significant pollutant emissions reduction (except for the HC increase, quite common in RCCI combustions) while keeping BSFC approximately equal to the CDC standard calibration.
Figure 4 reports a scheme of the RCCI combustion control methodology implemented in the RCP system.
Then, the closed loop controller was activated using as inputs the combustion indexes (indicated torque and CA50) calculated by the indicated system and sent to the RCP system via CAN bus.
The optimum histories of the heat release rates for low combustion noise and high thermal efficiency were calculated by simulations in single, two, and three stage combustions.
Much research has been on the reduction of diesel engine combustion noise by engine tests.
The maximum rate of pressure rise is a main cause of the combustion noise, and Shibata and Shibaike investigated other factors in the combustion noise generation .
Fuyuto reported the phenomenon that combustion noise generated in the second combustion could assist in reducing the combustion noise of the first fuel injection, termed "Noise Cancelling Spike Combustion (NCS combustion)" .
VNT is used to control the intake boosting to create proper phasing of HCCI combustion so as to achieve maximum efficiency.
This in turn sets up reactivity gradients inside the combustion chamber, and the combustion progresses gradually from the high reactive zones toward the low reactive zones .
 obtained lower thermal efficiency in RCCI compared to conventional combustion at low load conditions.
Based on our previous investigation  conducted in the test engine considered for the present work, similar conclusions of higher HC and CO emissions in RCCI compared HCCI, PCCI, and conventional combustion are drawn.