Marine natural gas engine combustion closed-loop control method and system

The invention discloses a closed-loop control method and system for combustion of a marine natural gas engine. Firstly, a cylinder pressure sensor is used for collecting pressure signals in a cylinder in the working process of the natural gas engine, and combustion characteristic parameters are extracted; then, a tight-format dynamic linearization data model is established through the combustion characteristic parameters and the control signals, and then a combustion closed-loop control scheme is designed; and finally, according to the expected value of the combustion characteristic parameter under the current natural gas engine operation condition, the control signal of the natural gas engine is adjusted, so that the combustion characteristic parameter reaches the expected value, and combustion closed-loop control is achieved. The method is suitable for controlling the combustion process of the marine natural gas engine with complex and changeable navigation environments, and has a good combustion control ef