A system for learning a difference between an actual injection amount and a target injection amount

摘要

A fuel injection system for an internal combustion engine provided with a multi-mass flywheel and an injector, the injector operating to inject a quantity of fuel into an internal combustion engine, the fuel injection system comprising: a learning fuel injection instruction unit that operates to output an instruction value to the injector, the instruction value instructing the injector to spray a target fuel amount as a learning process fuel injection; a speed measuring unit that operates to measure an engine speed request value at a plurality of polling times; a speed increase calculation unit for calculating a speed increase due to the learning process fuel injection; a fuel amount estimation unit that operates to estimate an amount of fuel actually injected from the injector by the learning process fuel injection based on the measured speed increase; and a calculation unit that operates to calculate a deviation of the amount of fuel actually injected from the injector from the target amount of fuel to be injected from the injector, thereby calculating a correction value of the instruction value for compensating the calculated deviation; wherein the speed increase calculation unit operates to: determines a rotational speed increasing range of the rotational speed due to the learning process fuel injection based on the rotational speed sensing values measured at the plurality of sampling times; selects at least two polling times among the plurality of polling times, the at least two selected polling times being before and after the speed increasing range; a first variation of the speed request values measured at the at least two request timings selected when no learning process fuel injection is performed is calculated as a baseline; and calculating a second variation of the speed demand values measured at some of the plurality of polling times, wherein some of the plurality of polling times are within the speed increase range, and calculates a difference between the second variation and the baseline as the speed increase.