Various embodiments include a method for identifying an inlet and an outlet valve stroke phase difference comprising: measuring pressure oscillations during operation; generating a corresponding signal; determining a corresponding crankshaft phase angle; applying a discrete Fourier transformation to the pressure signal to determine amplitudes of selected frequencies in relation to the crankshaft phase angle; determining lines of equal amplitudes of the frequencies based on the amplitudes depending on the phase differences using reference lines; determining an intersection of the lines by projection into a common plane; and determining the inlet valve stroke phase difference and the outlet valve stroke phase difference from the determined common intersection point of the lines of equal amplitudes of the selected signal frequencies.

A four-stroke internal combustion engine is disclosed comprising an exhaust valve control arrangement with an exhaust valve phase-shifting device configured to phase-shift control of the at least one exhaust valve to a state where the at least one exhaust valve is controlled in such a way that it is opened during the expansion stroke of the engine and closed during the exhaust stroke of the engine, in order to achieve engine-braking via compression in the cylinders during the exhaust stroke. An inlet valve control arrangement comprises an inlet valve phase-shifting device configured to regulate the amount of air pumped through the engine during the engine braking by regulating the phase-shift of the at least one inlet valve. The present disclosure also relates to a vehicle comprising an engine and method of controlling an engine, a computer program and a computer program for performing a method of controlling an engine.

A method of operating an internal combustion engine that includes a valvetrain having a rocker arm assembly including a rocker arm on which a latch pin is mounted. An actuator for the latch pin, including an electromagnet, is mounted separately from the rocker arm. Rocker arm position information is obtained by gathering and analyzing data relating to a current or voltage in an electrical circuit that is operative to power the electromagnet. The rocker arm position information is used to perform a diagnostic.

A method for controlling intake and exhaust valves of an engine may include: determining, by a controller, a target opening duration of the intake and exhaust valves based on an engine load and an engine speed; modifying, by an intake continuous variable valve duration (CVVD) device and by an exhaust CVVD device, current opening and closing timings of the intake valve and/or exhaust valve based on the target opening duration of the valves; and advancing or retarding, by the intake and/or exhaust CVVD devices, the current opening timing of the intake and exhaust valves while simultaneously retarding or advancing the current closing timing of the intake and exhaust valve by a predetermined value based on the target opening duration.

An apparatus and method for controlling deactivation of cylinders in an engine may include a sensor that measures pressure inside an intake manifold of the engine, an oil control valve (OCV) that deactivates the cylinders in the engine, and a controller that is configured to control the OCV to deactivate a specific cylinder in the engine, based on the pressure inside the intake manifold.

In a control device and a control method for a variable valve timing mechanism according to the present invention, the rotational phase of a camshaft is measured based on the cam angle signal and crank angle signal upon receiving each pulse of the cam angle signal, and the rotational phase change over time within a period of the cam angle signal is measured based on the motor angle signal. It is decided whether the cam angle signal and/or crank angle signal has a prescribed pulse pattern at a diagnostic timing that comes after the last pulse of the cam angle signal. When this decision result is positive, it is then decided whether the motor angle sensor operates normally or abnormally based on the rotational phase and the amount of rotational phase change that are measured when the last pulse of the cam angle signal is received before the diagnostic timing.

A phase adjustment mechanism for setting a relative rotational phase of a driven-side rotational body to a drive-side rotational body of a valve opening-closing timing control device includes a output gear around a rotational axis, an input gear being rotated around an eccentric axis, and an eccentric member. The eccentric member includes an outer peripheral surface with a first arc portion, a second arc portion, a plate spring fitted between the first arc portion and the second arc portion, and a spaced portion. Each of the first arc portion and the second arc portion is disposed from a position less than 90 degrees to a position more than 90 degrees as a central angle with respect to the eccentric axis from a biasing direction of the plate spring in the peripheral direction.

Various embodiments include a method for detecting deviations occurring in the valve drive of an internal combustion engine comprising: measuring dynamic pressure oscillations of intake air in an air intake tract of respective internal combustion engine during operation; calculating an inlet valve stroke phase difference and/or an outlet valve stroke phase difference based on the measured dynamic pressure oscillation; calculating a valve stroke phase deviation value with respect to a valve stroke phase reference value based on the calculated phase difference; and calculating a first valve drive deviation value based on the valve stroke phase deviation value.

In one embodiment, a method is provided. The method includes receiving a signal representative of an engine vibration transmitted via a knock sensor, wherein the knock sensor is disposed in an engine. The method additionally includes deriving a valve wear measurement during operation of the engine based on the signal. The method further includes communicating the valve wear measure.

Various embodiments include a method for identifying an inlet and an outlet valve stroke phase difference comprising: measuring pressure oscillations during operation; generating a corresponding signal; determining a corresponding crankshaft phase angle; applying a discrete Fourier transformation to the pressure signal to determine amplitudes of selected frequencies in relation to the crankshaft phase angle; determining lines of equal amplitudes of the frequencies based on the amplitudes depending on the phase differences using reference lines; determining an intersection of the lines by projection into a common plane; and determining the inlet valve stroke phase difference and the outlet valve stroke phase difference from the determined common intersection point of the lines of equal amplitudes of the selected signal frequencies.