Provided is an inductive position measuring sensor, comprising a fixed ruler (100) and a sliding ruler (200) which can move relatively along the direction of the measuring axis. A series of coupling coils (140) are made on the fixed ruler (100) in the measuring direction, two sets of driving coils (210, 220; 310, 320; 410, 420; 510, 520) are disposed on the sliding ruler, and induction coils (230, 240; 330, 340; 430, 440; 530, 540) in a staggered manner are also disposed on the sliding ruler (200). The two sets of driving coils (210, 220; 310, 320; 410, 420; 510, 520) generate excitation signals, by interaction with the coupling coils (140) on the fixed ruler, and being received by the induction coils (230, 240; 330, 340; 430, 440; 530, 540) of the sliding ruler, they are used for measuring the relative movement of the fixed ruler (100) and the sliding ruler (200). By controlling the positions and winding directions of the driving coils (210, 220; 310, 320; 410, 420; 510, 520) and the induction coils (230, 240; 330, 340; 430, 440; 530, 540), the sensor can effectively inhibit the direct space signal interference of the driving coils (210, 220; 310, 320; 410, 420; 510, 520) to the induction coils (230, 240; 330, 340; 430, 440; 530, 540), and the signal-to-noise ratio is improved.

A measurement device for measuring an angular position of a movable body that is rotatable about an axis of rotation relative to a stationary body, the device comprising, facing each other, a movable portion with a first printed circuit having first tracks formed thereon defining a plurality of target patterns and a stationary portion with a second printed circuit having second tracks formed thereon defining a plurality of measurement patterns that are angularly distributed in regular manner. The target patterns are angularly distributed in irregular manner, the number of target patterns is not less than two, and the product of the number of target patterns multiplied by the number of measurement patterns is not less than twelve.

A resolver system includes a rotatable primary winding, a secondary winding fixed relative to the primary winding, and an analog-to-digital converter electrically connected to the secondary winding. A control module is operatively connected to analog-to-digital converter and is responsive to instructions to apply an excitation voltage with an oscillating waveform to the primary winding, induce a secondary voltage using the secondary winding using the excitation voltage, and acquire a plurality of voltage measurements from the secondary winding separated by a time interval corresponding to π/3 of the excitation voltage oscillating waveform.

A sensor includes a ferromagnetic shield, at least one sensor coil disposed around an exterior of the ferromagnetic shield, and an electronics module within the ferromagnetic shield. The electronics module is configured to determine the position and/or orientation of the sensor based at least in part on a measurement of a signal induced in the at least one sensor coil.

There is provided a resolver comprising: a main body including an excitation coil to which an excitation signal is input and a detection coil configured to output a detection signal, wherein one of the excitation coil and the detection coil is provided in a fixed part and the other one thereof is provided in a rotating part; and a signal processor configured to detect a rotation angle of the rotating part on the basis of the detection signal that changes in accordance with the rotation angle.

A rotary encoder that is capable of securing a sufficient synthesis tolerance while achieving miniaturization is provided. The rotary encoder 1 includes a rotor 3, a stator 4, and a calculating unit 5 for calculating the rotation angle. The rotor 3 has a first rotor pattern 31 with a plurality of unit patterns 310 arranged along the measurement direction around the rotating shaft 2, and a second rotor pattern 32 with fewer unit patterns 320 than the plurality of unit patterns 310 in the first rotor pattern 310 arranged along the measurement direction. The number of the plurality of unit patterns 310 of the first rotor pattern 31 and the number of the plurality of unit patterns 320 of the second rotor pattern 32 are provided such that the maximum common divisor therebetween is two or more. The calculating unit calculates the rotation angle of the rotor 3 based on the detection signals from the first rotor pattern 31 and the second rotor pattern 32.

The electromagnetic induction displacement sensor consists of a transceiver board and an excitation board that may move relative to each other along a measuring path. The transceiver board is arranged with at least one transmitter winding and at least two three-phase receiver windings with different pitches, the number of three-phase receiver windings is one more than that of transmitter windings. Each transmitter winding encircles two three-phase receiver windings with different pitches in the same direction in series, and all receiver windings are in a distributed winding structure. The excitation board is arranged with at least two rows of excitation coils in the shape of short-circuit loop, the number of rows of excitation coils is equal to the number of the three-phase receiver windings on the transceiver board, respectively aligning with corresponding three-phase receiver winding and having the same pitch.

A rotational angle sensor includes a stator element and rotor element. The stator element has a stator transmitting coil and stator receiving coil. The rotor element is rotatably mounted about a rotation axis, relative to the stator element, and has a rotor receiving coil and rotor transmitting coil electrically connected to each other. The rotor receiving coil is inductively coupled to the stator transmitting coil such that an electromagnetic field produced by the stator transmitting coil induces a current in the rotor receiving coil that flows through the rotor transmitting coil and causes the rotor transmitting coil to produce a further electromagnetic field. The stator receiving coil is inductively coupled to the rotor transmitting coil such that the inductive coupling between the stator receiving coil and the rotor transmitting coil is configured with reference to a rotational angle between the stator element and the rotor element, and such that the further electromagnetic field induces an angle-dependent alternating voltage in the stator receiving coil. The stator transmitting coil has a first circular outer partial winding, and a first circular inner partial winding positioned within and electrically connected to the first outer partial winding such that the first inner partial winding has an opposite current flow with respect to the first outer partial winding. The rotor receiving coil has a second circular outer partial winding and a second circular inner partial winding positioned within and electrically connected to the second outer winding such that the second inner winding has an opposite current flow with respect to the second outer partial winding. The first and second outer partial windings, and the first and second inner partial windings are oriented with respect to each other, respectively.

The present disclosure relates to a displacement sensor. A displacement sensor according to the embodiment of the present disclosure includes a coil structure consisting of wound coil, a shield member formed to surround an outer periphery of the coil structure and a housing, wherein the housing comprises an upper side wall part surrounding an outer periphery of the shield member and a lower side wall part formed to extend from the upper side wall part, wherein an inner circumferential surface of the lower side wall part is protruded toward the inside of the housing more than an inner circumferential surface of the upper side wall part, wherein an outer circumferential surface of the lower side wall part may include a depressed region formed to be depressed into the inside of the housing by a predetermined depth.

An encoder comprises first and second sensors which reads first and second tracks, the first and second sensors being arranged in a radial direction to face each other, and a processor which generates a first position signal based on first and second periodic signals based on a signal obtained by reading the first and second tracks by the first sensor, and generates a second position signal based on third and fourth periodic signals based on a signal obtained by reading the first and second tracks by the second sensor, wherein the processor generates an absolute position signal indicating an absolute position of at least one of the scale, the first sensor, or the second sensor based on the first and second position signals and the first and third periodic signals.