The present disclosure provides magnetic sensor system that includes a magnetic sensing device comprising a magnetic multi-turn sensor, and an initialization device for setting the magnetic multi-turn sensor in a known state ready for use. The initialization device is in the form of a substrate, such as a printed circuit board, comprising one or more wires. A strong electrical pulse is applied to the one or more wires, which thereby generate a magnetic field that is strong enough to cause the magnetoresistive elements of the magnetic multi-turn sensor to be filled with domain walls, thereby magnetising each element into an initialized state.

An electric power steering apparatus has a rotation detection device that can recover from abnormalities in calculating an absolute angle. The rotation detection device includes a signal acquirer that acquires a mechanical angle and a count value from a sensor, and an absolute angle calculator that calculates an absolute angle based on the mechanical angle and the count value. The rotation detection device further includes an abnormality determiner that determines abnormalities in the calculation of the absolute angle. The absolute angle calculator stores an absolute angle hold value prior to the detection of the abnormality the absolute angle. When the abnormality of the absolute angle is resolved, the absolute angle calculator calculates a recovery-time absolute angle, and returns to a normal-time absolute angle calculation.

The invention relates to a counting sensor for counting the number of revolutions or of linear displacements of an object, wherein the counting sensor comprises: one single Wiegand module; at least one sensor element; a processing electronics connected to the sensor element; and a permanent magnet arrangement, which is movable relative to the Wiegand module; wherein the processing electronics is configured to obtain (i) direction informations indicating whether the permanent magnet arrangement moves in one direction or an opposite direction, and (ii) magnetic pole informations; and a data storage for storing a value, which indicates the number of the revolutions or of the linear displacements; wherein the processing electronics is configured: (i) to determine, on the basis of the direction information and the magnetic pole information, the number of the revolutions or of the linear displacements of the object and to store the corresponding value in the data storage, (ii) to perform, on the basis of a sequence of the direction informations and the magnetic pole informations, an error detection indicating whether one of the revolutions or one of the linear displacements of the object has not been recognized partially or completely, and (iii) upon detection of the error, to determine a corresponding correction of said number and to correct said value.

Aspects of this disclosure relate to a magnetic sensor system for measuring any desired combination of measuring torque, rotation angle, and turn count of a shaft. The shaft may include two portions connected by a torsion element. The system can measure rotation angle using a magnetic target coupled to the shaft that produces a magnetic field that varies as a function of rotation angle. The system can measure torque applied to the shaft by measuring the difference in rotation angles between the two portions of the shaft and factoring in a torsion coefficient. The system can track a turn count of the shaft using a multi-turn sensor. The magnetic sensor system may be part of an electric power assisted steering (EPAS) system.

Disclosed is a method for counting events occurring during a period T carried out by a mechanical counter including two toothed wheels with the same pitch, the occurrence of an event causing the rotation of each wheel by an angle corresponding to the pitch of the teeth thereof, the method including: counting or calculating, for each wheel at the end of T, the difference in the number of teeth between the initial and final position thereof, the step being at least partially carried out either by an optical unit, requiring the presence on each wheel of at least one marker, or by a unit for measuring the angular displacement of each wheel and associated calculation unit; and calculating the number of occurred events N in accordance with the difference between the values counted or measured and in accordance with the number of teeth of the wheels.

A system includes a multiturn counter that can store a magnetic state associated with a number of accumulated turns of a magnetic field. The multiturn counter includes a plurality of magnetoresistive elements electrically coupled in series with each other. A matrix of electrical connections is arranged to connect magnetoresistive elements of the plurality of magnetoresistive elements to other magnetoresistive elements of the plurality of magnetoresistive elements.

A method is for calibrating a multiturn sensor for determining the position of a spindle of a clutch actuator, in which the multiturn sensor (5) is operatively connected to a magnetic field of a permanent magnet (12) in that the multiturn sensor (5) is combined with an actuator transmission (3) which comprises a spindle (9) bearing the permanent magnet (12). In a calibration method which can be carried out particularly quickly and cost-effectively, during the assembly of the multiturn sensor (5), arranged on a carrier element (4), with the actuator transmission (3) bearing the spindle (9), the multiturn sensor (5) is operated outside its specified rotational range (0, n), wherein a position, set by actuating the actuator transmission (3), of the spindle (9) bearing the permanent magnet (12) provided for an operating case of the clutch actuator (1), is assigned to a specified end position of the rotational range (0, n) of the multiturn sensor (5), as a result of which a magnetic field of the permanent magnet (12) is aligned with the multiturn sensor (5).

The invention relates to a sensor system (1), and a method for determining an absolute rotation angle (δ) of a shaft (10) with a rotation angle range of more than one revolution and to a vehicle fitted with a sensor system (1), wherein the sensor system (1) has a main rotor (2) that can be connected rotationally synchronously to the shaft (10), a first auxiliary rotor (3) which is mechanically coupled to the main rotor (2), a second auxiliary rotor (4) mechanically coupled to the main rotor (2), a first sensor device (SE1) which is assigned to the first auxiliary rotor (3) for generating a first sensor signal dependent on a rotation angle of the first auxiliary rotor (3), a second sensor device (SE2) which is assigned to the second auxiliary rotor (4) for generating a second sensor signal dependent on a rotation angle of the second auxiliary rotor (4), a third sensor device (SE3) which is assigned to the main rotor (2) and which is used for generating a third sensor signal dependent on a relative rotation angle (γ) of the main rotor (2) and an evaluation device for determining the absolute rotation angle (δ) of the main rotor (2) from the sensor signals of the sensor devices (SE1, SE2, SE3). The detection range (α) of the third sensor device is less than 360°.

An absolute position detection apparatus includes a calculator configured to generate, based on a detection signal, a first signal, and a second signal. A relative movement range of the scale and the sensor includes a boundary between adjacent detection units in the first signal such that at least one of the boundary is included in each of a plurality of areas in the relative movement range. The calculator is configured to specify a detection unit, to be used to calculate the absolute position, in the first signal based on a code of each detection unit of the second signal in an area that includes the boundary of the plurality of areas.

The present disclosure provides a method of monitoring the magnetic field in which a magnetic sensor is operating in to ensure that the sensor is operating within its defined magnetic window. For example, the method uses the sensor output of either a multi-turn sensor, or some other magnetoresistive sensor that is being used in conjunction with the multi-turn sensor, for example, a magnetic single turn sensor or a second multi-turn sensor, to monitor the operating magnetic field.