The systems and methods described herein provide an approach for cam phase angle control where an axial or rotational position of an actuator of a cam phaser has a direct relationship to the phase angle of the cam shaft, allowing for accurate cam phasing without the need for cam shaft or crank shaft position sensors. Providing phase angle adjustability without the need for crank shaft or cam shaft position sensors enables control of phase angle solely by sensing the axial or rotational position of the actuator of the cam phaser.

A method for synchronizing an internal combustion engine includes: a) a first step of acquiring, by the camshaft sensor, signals corresponding to at least five cam edges x; b) a second step of determining the value, from the camshaft signal, of a first, second and third actual ratio; c) a third step of establishing, for each actual value ratio obtained in b), a list of possible cam edges x by comparing the values of the first, second and third actual ratios, respectively, with a tolerance window corresponding to a value of a first, second or third theoretical ratio for a given cam edge x, each weighted by a tolerance factor k; and d) a fourth step of determining the cam edge x seen by the camshaft sensor, the cam edge actually seen by the sensor corresponding to the cam edge x common to the three lists established in c).

An internal combustion engine has one or more combustion chambers defined by one of more cylinders, corresponding pistons, and a cylinder head. A crankshaft is operatively connected to the pistons and to an electric turning machine. To start the engine, the electric turning machine rotates the crankshaft in a first direction toward a reversal point corresponding to a local maximum drag torque of the internal combustion engine, this rotation being made without rotating the crankshaft beyond the reversal point. The electric turning machine then rotates the crankshaft in a second direction opposite from the first direction, a momentum impressed on the crankshaft by compression obtained when rotating in the first direction increasing a speed of the crankshaft in the second direction. Thereafter, fuel is injected in one of the combustion chambers in which the corresponding piston first reaches a top dead center position and the fuel is ignited.

A continuous variable valve duration apparatus includes: a camshaft, a front cam unit and a rear cam unit of which the phase relative to the camshaft can be varied, a front inner wheel and a rear inner wheel, a front guide bracket and a rear guide bracket, a front wheel housing and a rear wheel housing, a front control shaft, a rear control shaft, a phase controller selectively changing the relative phase of the front control shaft and the rear control shaft, a main driving unit for driving the rear control shaft, vibration sensors that measure the vibration of each cylinder corresponding to the front cam unit and the rear cam unit and output a corresponding signal, and a controller for controlling the operation of the main driving unit and the phase controller according to the output signals of the respective vibration sensors.

An arrangement for cylinder detection in a four-stroke internal combustion engine is disclosed. The arrangement comprises a first disc connected to a crankshaft, the first disc comprising a first mark (M11-M13) within each an interspace angle (α), and a second disc connected to a camshaft and comprising one second mark (M21-M26) per number of cylinders. The first mark (M11-M13) is arranged on a first disc, or the plurality of first marks (M11-M13) are arranged in relation to each other on the first disc, and the second marks (M21-M26) are arranged in relation to each other on the second disc such that for each interspace angle (α) the relevant first mark (M11-M13) is detectable by a first sensor and the relevant second mark (M21-M26) is detectable by a second sensor at different relative rotational positions between the first disc and the second disc.

A method includes determining a value of an operational motor current limit and setting a value of a startup current limit equal to a predetermined value in excess of the value of the operational motor current limit if a set of predetermined conditions is satisfied. The method includes determining that operation of the engine has been interrupted, operating the electric motor of the variable valve timing mechanism with a current having a magnitude that is less than or equal to the startup current limit after determining that operation of the engine has been interrupted, determining that operation of the engine has resumed, and operating the electric motor of the variable valve timing mechanism with a current having a magnitude that is less than or equal to the operational motor current limit after determining that operation of the engine has resumed.

A combined plug-sensor wheel for a camshaft is disclosed. The combined plug-sensor wheel includes a pin projecting in an axial direction of the camshaft. The pin, when inserted into the camshaft, seals the camshaft in a fluid-tight manner. According to an implementation, the combined plug-sensor wheel and the camshaft are incorporated into an internal combustion engine.

A variable camshaft timing (VCT) system includes an independent camshaft phaser, receiving input from a crankshaft of an internal combustion engine, having an output coupled to one of an inner concentric camshaft or an outer concentric camshaft; and a dependent camshaft phaser, coupled to the other of the inner concentric camshaft or the outer concentric camshaft, comprising a half-Oldham link configured to permit radial movement of the inner concentric camshaft relative to the outer concentric camshaft in one radial direction and at least one pivotable arm configured to permit radial movement of the inner concentric camshaft relative to the outer concentric camshaft in another, different radial direction.

A camshaft toothed wheel, forming a target for a camshaft rotation sensor, including a plurality of teeth distributed over its circumference. The toothed wheel including a first set of four teeth each spaced apart by 90°, and a second set of six teeth each spaced apart by 60°. The teeth of each set being distributed such that the wheel includes two portions of its circumference without an active edge of teeth over an angle of at least 35° and which are spaced apart by 180°. The teeth of the first set of teeth and of the second set of teeth being arranged such that no tooth is common to the first set of teeth and to the second set of teeth.

A toothed wheel forming a target for a camshaft position sensor includes a circular body provided with two opposite main faces and is provided on its circumference with teeth. The series of teeth includes eight teeth, each tooth having, for a given first direction of rotation of the wheel, a rising edge and a falling edge and two neighboring teeth being separated by a recessed part. The edges of a first type, rising or falling, are evenly distributed at the periphery of the toothed wheel. The angular length of the recessed parts is greater than or equal to arctan(Llow/R)°CAM, where R is the radius and Llow is the minimum distance between two teeth to detect a low level, except for one recessed part, and the angular length of a tooth is greater than arctan(Lhigh/R)°CAM, except for one tooth, where Lhigh is the minimum length of a tooth allowing detection.