Systems and methods for non-intrusive closed-loop combustion control of internal combustion engines

A method for controlling fuel injection of an internal combustion engine comprising:

• operating an internal combustion engine, the internal combustion engine having an intake manifold, a plurality of cylinders, a fuel injector for each cylinder, an exhaust manifold, an intake manifold sensor configured to sense an intake manifold temperature data of the internal combustion engine, a fuel injector sensor configured to sense a fuel injector operating condition data of the internal combustion engine, an exhaust manifold sensor configured to sense an exhaust manifold gas oxygen concentration data of the internal combustion engine, an exhaust gas recirculation (EGR) sensor configured to sense an EGR gas temperature data of the internal combustion engine, and an electronic control unit (ECU) with one or more processors and a non-transitory computer-readable medium storing computer-executable instructions, the computer-executable instructions comprising a Gaussian process model, the ECU configured to receive data from the intake manifold sensor, the fuel injector sensor, the exhaust manifold sensor, and the EGR sensor;
• obtaining the data from the intake manifold temperature sensor, the fuel injector sensor, the exhaust manifold sensor, and the EGR sensor and transmitting the data to the ECU;
• estimating a combustion parameter value of the internal combustion engine using the Gaussian process model with the data from the intake manifold temperature sensor, the fuel injector sensor, the exhaust manifold sensor, and the EGR sensor as input to the Gaussian process model;
• obtaining a desired combustion parameter value from an empirically determined look-up table;
• comparing the estimated combustion parameter value with the desired combustion parameter value;
• and
• commanding a control parameter for the fuel injector of each cylinder as a function of the comparison of the estimated combustion parameter value and the desired combustion parameter value.