A CPU substitutes a difference between a crank-side speed that is a rotation speed of a crankshaft and a downstream-side speed that is a speed of a portion, opposite from the crankshaft, in a damper into a differential speed. The CPU calculates a torsion angle through a process of integrating the differential speed. The CPU calculates a torsion speed component that is a speed component of the crankshaft due to torsion of the damper based on a process of integrating a value obtained by multiplying the torsion angle by an elastic modulus, and calculates a time that is a variable indicating a speed of the crankshaft, used to determine a misfire, based on the torsion speed component. The CPU subtracts a value obtained by subtracting an output value of the integrating process, applied to a finite response low-pass filter process, from the output value.

A system, method and device for mass airflow sensor signal processing includes a microcontroller, a mass airflow sensor and an engine PCM. An analog-to-digital converter (ADC) converts a first output signal from the mass airflow sensor to a first V.sub.DC value. A digital-to-analog converter (DAC) converts a second V.sub.DC value to a second output signal associated with the mass airflow sensor. Transfer functions are obtained from a flow bench using the mass airflow sensor, performance air intake components, and stock air intake components. The microcontroller determines, from the first V.sub.DC value, a corresponding actual flow rate. From the actual flow rate, a corresponding stock V.sub.DC value is determined. The stock V.sub.DC value is then output to the DAC for conversion to the output second signal associated with the mass airflow sensor for communication to the engine PCM.

Methods and systems are described for monitoring air/fuel imbalance in cylinders of an engine. Engine speed signals are sampled and then run through a notch filter set to the sampling frequency. Based on a first frequency content of the resulting filtered engine speed, cylinder imbalance is detected and addressed.

A method for engine combustion noise feedback control includes calculating an engine combustion noise target value by a controller. A cylinder pressure is measured after combustion of fuel according to a main injection timing and an amount of pilot fuel based on the calculated engine combustion noise target value. A combustion noise index (CNI) is calculated by converting the measured cylinder pressure into a cylinder pressure level. The feedback pilot injection is controlled in which the CNI is applied to injection variable control while controlling the main injection timing and the amount of pilot fuel.

A data processing method is a data processing method in which variable measurement data transmitted from a sensor at a first cycle is computationally processed at a second cycle that is longer than the first cycle. The measurement data is acquired in a third cycle that is longer than the first cycle and shorter than the second cycle, an average value of the acquired measurement data is calculated at the second cycle, and computation processing thereof is performed.

An apparatus and method for controlling a fuel injection system of an internal combustion engine is disclosed. Each fuel injector in the system is operated to perform a predetermined injection pattern per engine cycle. A signal representative of a fuel pressure within the fuel rail during the operation of the fuel injectors is sampled. A Fourier analysis of the fuel rail pressure signal is performed to determine one or more harmonic components thereof. The determined harmonic components of the fuel rail pressure signal are used to calculate a dynamic fuel quantity that flows through a fuel injector during an injection pulse of the injection pattern. A fuel quantity actually injected by the fuel injector during the injection pulse as a function of the dynamic fuel quantity is calculated.

A method for determining a combination of an actual intake camshaft phase position of an intake camshaft and an actual exhaust camshaft phase position of an exhaust camshaft of a production internal combustion engine having at least one cylinder, wherein the method is performed in operation of the production internal combustion engine and the relevant actual phase position of the camshafts is determined in relation to an operating point of the production internal combustion engine.

A method for operating an internal combustion engine having a common-rail injection system as a function of a quantity of fuel injected. The method includes determining an information item about a relative-pressure characteristic from a characteristic of an absolute rail pressure in a high-pressure reservoir of the common-rail injection system; determining the quantity of fuel injected as a function of the information item about the relative-pressure characteristic, and with the aid of a trained functional model, in particular, a nonparametric functional model or a neural network; operating the internal combustion engine as a function of the quantity of fuel injected.

Provided is an internal combustion engine control device capable of more appropriately correcting an output value of a flow rate sensor that measures a flow rate of air flowing through an intake flow path of an internal combustion engine, and further reducing an error between a corrected air flow rate and an actual air flow rate as compared to a conventional device. For this purpose, the internal combustion engine control device of the present invention includes an arithmetic device 100 including a fundamental frequency derivation unit 104 that derives a fundamental frequency, a flow rate amplitude calculation unit 107 that extracts a radio frequency of a plurality of frequencies equal to or higher than the fundamental frequency from a pulsation waveform based on the output value of the flow rate sensor as a flow rate radio frequency and calculates an amplitude of the flow rate radio frequency for each frequency, a correction amount derivation unit 108 that derives a correction amount based on the amplitude of the flow rate radio frequency for each frequency, and a flow rate calculation unit 109 that calculates a flow rate of air by using the output value of the flow rate sensor and the correction amount.

There is provided a blade angle feedback system for an aircraft-bladed rotor rotatable about a longitudinal axis and having an adjustable blade pitch angle. A feedback device is coupled to rotate with the rotor and to move along the axis with adjustment of the blade pitch angle. The feedback device comprises a body having position marker(s) embedded therein, the body made of a first material having a first magnetic permeability and the position marker(s) comprising a second material having a second magnetic permeability greater than the first. Sensor(s) are positioned adjacent the feedback device and configured for producing, as the feedback device rotates about the axis, sensor signal(s) in response to detecting passage of the position marker(s). A control unit is communicatively coupled to the sensor(s) and configured to generate a feedback signal indicative of the blade pitch angle in response to the sensor signal(s) received from the sensor(s).