An electromagnetic tracking system with three non-concentric, non-parallel transmitter coils to generate the magnetic fields and sensor coils to generate magnetic sensor data, from which position and orientation of the sensor is determined. In one embodiment, the three non-concentric transmitter coils are attached to or mounted in a Head Mounted Display (HMD). Having the three transmitter coils be non-concentric reduces overall bulkiness and spreads the weight of the transmitter coils over a larger area.

The present invention relates to providing an electrical voltage for exciting an excitation coil of a resolver (2). In this case, the electrical voltage for exciting the excitation coil of the resolver (2) can be generated by means of pulse-width-modulated driving of at least one half-bridge (H1). In this case, the switching elements of the half-bridge (H1) are fully turned on, with the result that losses such as occur during linear operation of semiconductor switches, for example, can be avoided. If appropriate, the voltage (U_e) provided by the half-bridge (H1) can be additionally increased by means of suitable resonant circuits (L1, C1, C3 . . . ).

A method of making a machine system includes assembling sensing elements with a sensor frame, and contacting ferrite cores of the sensing elements with a locating tool to conform an arrangement of the sensing elements to a cylindrical shape of a surface of the locating tool. The sensing elements are secured to the sensor frame in the determined arrangement, and coupled with a housing of a machine system to monitor position of a rotatable component therein. The ferrite cores may be E-type cores, with bridge connections used to sensitize the sensing mechanism to displacement of a rotatable component in X, Y, and Z directions.

The electromagnetic induction type position detector includes a scale having a plurality of gradation coils, a head having a transmission unit and a reception unit, and a control unit. Each of the plurality of graduation coils includes a transmission graduation arranged with a pitch L1, a reception graduation arranged with a pitch L0 different from the pitch L1, and a connection unit. The transmission unit includes three transmission coil groups that are constituted by pluralities of transmission coils, each being arranged with a pitch L1, and that are arranged such that adjacent transmission coil groups have a phase difference. The reception unit includes three reception coil groups that are constituted by pluralities of reception coils, each being arranged with a pitch L0, and that are arranged such that adjacent reception coil groups have a phase difference identical to the phase difference of the three transmission coil groups.

A resolver includes: a sine exciting coil and a cosine exciting coil; a detecting coil that is provided to a rotor and is placed facing the sine exciting coil and the cosine exciting coil; an exciting coil forming a closed circuit, together with the detecting coil, in the rotor; and a sine detecting coil and a cosine detecting coil that are provided to a stator, are placed facing the exciting coil, and transmit alternating current signals that are 90 electrical degrees apart in phase. The multiplication factor of angle of the sine detecting coil, the cosine detecting coil, and the exciting coil is different from the multiplication factor of angle of the sine exciting coil, the cosine exciting coil, and the detecting coil.

A rotation angle detecting device and an electric motor provided with the rotation angle detecting device. The rotation angle detecting device has both a reduced thickness and outer diameter and is easily fixed to a small-sized electric motor. The rotation angle detecting device has a first sheet coil, provided with an excitation coil, mounted on a base fixed to a fixed body, a second sheet coil, provided with a detecting coil, mounted on a surface of a rotating plate opposite the base, the rotating plate is fixed to a rotating shaft, a third sheet coil, provided with a primary coil of an output transformer, mounted on another surface of the rotating plate opposing to a cover, and a fourth sheet coil, provided with a secondary coil of the output transformer, mounted on a facing surface of the cover opposite the rotating plate.

A rotation angle detecting device and an electric motor provided with the rotation angle detecting device. The rotation angle detecting device has both a reduced thickness and outer diameter and is easily fixed to a small-sized electric motor. The rotation angle detecting device has a first sheet coil, provided with an excitation coil, mounted on a base fixed to a fixed body, a second sheet coil, provided with a detecting coil, mounted on a surface of a rotating plate opposite the base, the rotating plate is fixed to a rotating shaft, a third sheet coil, provided with a primary coil of an output transformer, mounted on another surface of the rotating plate opposing to a cover, and a fourth sheet coil, provided with a secondary coil of the output transformer, mounted on a facing surface of the cover opposite the rotating plate.

A multi-degree-of-freedom displacement measuring device includes a rotary scale that has a scale pattern including a plurality of patterns that are arranged around a first rotation axis and arrayed along a circumference direction of the rotary scale, a detection head group including a plurality of detection heads, each of which is provided around the first rotation axis, is arranged on an installation face facing the rotary scale, and is configured to detect each of the plurality of patterns from the scale pattern, and a calculator configured to, based on detection values acquired by the plurality of detection heads, calculate a relative rotation angle around the first rotation axis, and calculate at least one of a relative movement amount in a direction along the first rotation axis and a relative movement amount in a direction along a second rotation axis orthogonal to the first rotation axis.

A magnetic response section provided by a scale of a magnetic linear sensor is configured so that changes in magnetic influence on a magnetic detection head appear alternately and repeatedly every first pitch in a displacement detection direction. The magnetic detection head is provided on one side of the scale in the first direction, which is a direction perpendicular to the displacement detection direction, and provided with a base substrate section and a plurality of signal output sections. The signal output sections are arranged on an insulating plate and in the displacement detection direction at a second pitch based on a first pitch. The first conductive pattern and the second conductive pattern included by each of the signal output sections are formed to arrange coil elements side by side in an elongated area in a second direction orthogonal to both the displacement detection direction and the first direction.

In a resolver, a detecting stator core includes a first detection winding group, a second detection winding group, and a plurality of excitation windings. The first detection winding group includes a plurality of first windings as detection windings. The second detection winding group includes, as detection windings, a plurality of second windings different from the first windings in the phase of the detection voltage. The excitation windings are each wound around one of teeth of the detecting stator core. Each first winding and each second winding are wound around different teeth from each other without being wound around the same tooth. The detection winding and the excitation winding that are wound around the same tooth are arranged so as to be separated from each other in a radial direction.