A calibrator includes: a position calculator which calculates a relative position between a first detector and a second detector on the basis of detection signals acquired respectively from the first detector, the second detector, and a third detector positioned with respect to a scale attached to a rotating body; and an error calculator which calculates error information on rotational position information of the rotating body on the basis of the relative position calculated by the position calculator as well as the detection signals.

An inductive rotor position sensor device for detecting a rotor angular position of a rotor of an electric machine. The inductive rotor position sensor device includes a transmitter coil for generating electromagnetic waves and a receiver coil for detecting the electromagnetic waves generated by the transmitter coil and influenced by the rotor, and includes a processing unit, which is designed to activate the transmitter coil and to evaluate the electromagnetic waves detected by the receiver coil for determining the rotor angular position. The coils and the processing unit are situated on a shared circuit board. The coils are situated on a front side, and the processing unit is situated on a rear side of the circuit board which faces away from the front side.

A rotary scale apparatus for an encoder apparatus including a planar disc on which at least one track including scale features is provided, in which the planar disc includes a hole through its centre for receiving a cylindrical shaft, and in which the rotary scale member includes at least three cantilevered spring members which are provided substantially in plane with the planar disc and spaced around the edge of the hole, for engaging with, and radially locating the disc on, a cylindrical shaft inserted therethrough.

There is provided an optical encoder with alignable relative positions between elements including an encoding medium, a sensor package and a memory. The sensor package includes a photodiode array and two alignment photodiodes opposite to the encoding medium. The memory records an alignment pattern associated with output signals of the two alignment photodiodes when the encoding medium and the sensor package are at nominal operating positions. When the encoding medium and the sensor package are not at the nominal operating positions, the relative position alignment is performed by adjusting current relative positions between the encoding medium and the sensor package to cause a current pattern associated with output signals of the two alignment photodiodes to be identical to the alignment pattern.

The invention relates to a system comprising a coder that has an alternation of North and South magnetic poles separated by transitions extending along a helix of pitch p and of angle α, the magnetic track having N.sub.pp pairs of North and South poles and a polar width L.sub.p measured along a normal to the transitions which are: N.sub.pp=πa/l, and L.sub.p=p.Math.cos α. The invention also includes at least one sensor able to detect the rotating magnetic field in a plane perpendicular to the magnetic track and to the transitions by means of a mounting of at least two sensitive magnetic elements. The mounting being disposed at a radial reading distance from the magnetic track and being arranged to deliver signals in quadrature.

A position sensor system is arranged for determining a position of a sensor device movable along a predefined path relative to a magnetic source. The system includes the magnetic source and the sensor device. The magnetic source has a first plurality of magnetic pole pairs arranged along a first track and a second plurality of magnetic pole pairs arranged along a second track, centrelines of the tracks are spaced apart by a predefined track distance. The sensor device is configured for measuring at least two orthogonal magnetic field components at a first sensor location, and at least two second orthogonal magnetic field components at a second sensor location. The first and second sensor location are spaced apart by a predefined sensor distance smaller than the predefined track distance, in a direction transverse to the tracks.

In accordance with one embodiment of the present disclosure, an inductive position sensor assembly is provided. The inductive sensor assembly includes a sensor and a coupler element. The sensor includes a transmitter coil having an inner diameter and an outer diameter and a receiver coil positioned within the outer diameter of the transmitter coil. The coupler element has a geometric continuous curve shape. The coupler element is positioned within the outer diameter of the transmitter coil such that a maximum diameter of the geometric continuous curve shape is the outer diameter of the transmitter coil. When the coupler element is moved, the geometric continuous curve shape of the coupler element modify an inductive coupling between the transmitter coil and the receiver coil.

A rotation detection device includes: a detector arranged with a gap to a rotating body in which rotation position information is periodically provided at regular intervals, and detecting a magnetic change as a rotation position of the rotating body; and a signal processor acquiring the rotation position information. The detector has first and second magnetic elements arranged with an interval of a/2 in a rotation direction. Each regular interval is defined as a. The first magnetic element outputs a first signal having a period corresponding to the regular intervals. The second magnetic element outputs a second signal having an opposite phase to the first signal and the period. The signal processor acquires a differential signal between the first and second signals as the rotation position information.

Method of determining a position of a sensor device relative to a magnetic source, includes: a) determining a first and a second magnetic field component at a first sensor location; b) determining a third and a fourth magnetic field component at a second sensor location; c) determining a first difference of the first and third component, and determining a second difference of the second and fourth component, and determining a first angle based on a ratio of the first and second difference; d) determining a first sum of the first and third component, and determining a second sum of the second and fourth component; e) determining a second angle based on a ratio of said first and second sum; f) comparing the first and second angle to detect error.

A system for measuring an angular position of a rotor with respect to a stator, wherein the rotor is rotatable around a rotation axis, and the system includes: a magnetic source mounted on the rotor, having at least four magnet poles and providing a periodically repetitive magnetic field pattern with respect to the rotation axis; a sensor mounted on the stator and comprising a plurality of sensor elements for measuring at least one magnetic field component of the magnetic field and for providing a measurement signal thereof; the sensor being located substantially centered around the rotation axis, in a plane substantially perpendicular to the rotation axis at a first distance from the magnetic source; the sensor elements being located substantially on a circle at a second distance from the rotation axis; a calculator that determines the angular position by calculating it from the measurement signals.