System and method for predicting quantity of injected fuel and adaptation to engine control system

A system for deriving a formula for calculating a quantity of fuel injected by an electric-actuated fuel injector during an injection wherein duration of the injection is set by duration of an electric signal applied to the fuel injector and pressure at which the fuel is injected is set by pressure of hydraulic fluid applied to the fuel injector, the system comprising:

• mapping apparatus for mapping the fuel injector by applying, to the fuel injector, various combinations of different selected hydraulic fluid pressures and different selected durations of the electric signal, and for each combination, measuring the quantity of fuel injected to create a corresponding data set for the combination that comprises the corresponding selected hydraulic fluid pressure, the corresponding selected electric signal duration, and the quantity of fuel injected in consequence of the application, to the fuel injector, of the corresponding selected hydraulic fluid pressure and the corresponding selected electric signal duration;
• and
• processing apparatus for processing data from the data sets to create terms of a multiple term mathematical formula for calculating the quantity of fuel injected, wherein the terms of the formula include as variables, the electric signal duration and the hydraulic fluid pressure.

An internal combustion engine comprising:

• one or more electric-actuated fuel injectors each of which injects fuel into a respective combustion chamber of the engine as a function of injector control pressure and the duration of an electric actuating signal that sets the duration of a fuel injection to achieve an injection quantity determined at least in part by a desired fueling data representing desired fueling of the engine;
• and an engine control system comprising one or more processors that calculate the desired fueling data, and from the desired fueling data, the duration of the electric actuating signal for each fuel injector by processing the desired fueling data and data representing injector control pressure, including processing, according to a mathematical formula, data correlated with the desired fueling data and data representing injector control pressure, to develop data that the control system further processes to calculate the duration of the electric actuating signal.