Combustion system

A combustion system comprising:

• an injection apparatus configured to inject fuel into a combustion chamber of an engine;
• an ignition plug configured to perform ignition on fuel in the combustion chamber;
• and
• a normal control unit configured to perform a normal control to cause the injection apparatus to perform predetermined normal injection and subsequently to cause the ignition plug to perform the ignition, wherein
• in a predetermined delay region in the combustion chamber, propagation of flame, which is caused by the ignition, is retarded further than in another region when the normal control is performed,
• in a knock state, self-ignition occurs in fuel in the delay region when the normal control is performed,
• the combustion system further comprising:
• an electromagnetic sensor configured to detect an electromagnetic wave generated in the combustion chamber;
• and
• an adjustment control unit configured to
• detect, based on the detected electromagnetic wave, delay region information, which is related to the delay region, and
• perform a predetermined adjustment control based on the delay region information to suppress the self-ignition, wherein
• the adjustment control is to
• cause the injection apparatus to perform predetermined main injection and subsequently perform predetermined sub-injection in a second half of a compression stroke to adjust a fuel distribution in the combustion chamber to facilitate propagation of the flame, which is caused by the ignition, to the delay region further than in the normal injection, and
• subsequently cause the ignition plug to perform the ignition.