Gm Global Technolgoy Operations, Inc.

Maura Dintino

Paolo Zamboni

Stefano Nieddu

Eugenio Pisoni

Vincenzo Rampino

Roberto Vernassa

A method to minimize common rail pressure irregularities due to aliasing effect on battery voltage monitoring in a digital electronic control unit that is capable of PWM (Pulse Width Modulation) regulations of a metering valve unit in a diesel common-rail power-train system. At least an engine rotary speed signal is detected and at least a battery voltage signal is monitored, the method includes, but is not limited to calculating the aliasing frequency on said battery voltage signal as a function of said engine rotary speed signal, filtering the battery voltage signal before it is input to said controller module with at least one digital non-linear notch filter, the at least one digital non-linear notch filter centered about the first harmonic of the aliasing frequency, and input the filtered battery voltage signal, at least with the engine rotary speed signal, to the controller module for PWM regulating the metering valve unit.

Method to minimize common rail pressure irregularities due to aliasing effect on battery voltage monitoring

Methods, a fuel supply system, and a computer readable medium embodying a computer program product are provided for controlling rail pressure in a fuel supply system comprising a fuel pump, an injector and a rail connecting the injector to the pump. At least one of the methods includes, but is not limited to establishing a relationship between said rail pressure and a leak rate of the injector, estimating a fuel drain rate from said rail based on a fuel injection rate, the rail pressure and said rail pressure/leak rate relationship, estimating a desired intake flow rate of said pump based on said fuel drain rate, and controlling the pump to operate at said desired intake flow rate.

Method and system for controlling fuel pressure

In a fuel injection system of an internal combustion engine, including, but not limited to a high pressure pump adapted to deliver a fuel mass conveyed from a fuel tank to a high pressure region to which a plurality of injectors is connected, including a fuel metering device for adjusting the fuel quantity to be delivered to the high pressure region, a pressure sensor for measuring fuel pressure in the high pressure region; and an electronic control unit arranged for driving the fuel metering device through an energizing signal (Inom; Iact) as a function of the measured fuel pressure and the engine operating mode, where the electronic control unit is arranged for determining the energizing signal (Inom; Iact) for driving the fuel metering device according to a nominal characteristic curve (A) of the high pressure pump representative of a predetermined relationship between the energizing signal and the fuel mass delivered by the pump, the operating pressure is controlled by driving the fuel metering device with an energizing signal determined according to an updated characteristic curve (B) estimated by applying to the nominal characteristic curve (A) an offset between the actual energizing signal value (Iact) related to the controlled fuel mass delivered to the high pressure region in a predetermined engine operating point and a nominal energizing signal (Inom) related to the controlled fuel mass according to the nominal characteristic curve (A).

Method and system for controlling a high pressure pump, particularly for a diesel engine fuel injection system

In a fuel injection system of an internal combustion engine that includes, but is not limited to injectors (I-I), each of which is adapted to deliver a predetermined amount of pressurized fuel to a combustion chamber of a respective cylinder (C-C) of the engine, a high-pressure accumulator volume common to the injectors (I-I) and arranged to maintain the fuel at high-pressure, a pressure sensor for measuring fuel pressure in the accumulator volume, a metering unit for adjusting the fuel pressure in the accumulator volume as a function of the measured pressure, so as to maintain a predetermined target injection pressure set-point dependent on the engine operating point by returning excess fuel to a fuel tank; and an electronic control unit arranged for controlling fuel injection timing and quantity by operating injectors control valves, the operating pressure is controlled by triggering retarded injections (INJpost) of a predetermined quantity of fuel to the combustion chamber of the cylinders (C-C) of the engine during a respective exhaust stroke, when pressure above a predetermined threshold (THover) is detected in the accumulator volume, so as to discharge fuel from the accumulator volume without it taking part to the combustion process, thereby reducing pressure in the accumulator volume.

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Turin, Italy

Maura Dintino