A rotation angle detection apparatus includes a magnet that is provided to a rotating shaft of a rotating body and rotates with the rotating shaft to generate magnetic flux and a magnetic sensor that is provided at a distance from the magnet and detects a magnetic flux interlinked with the magnetic sensor. The rotation angle detection apparatus has a magnet magnetic flux detection circuit that detects a magnet magnetic flux generated from the magnet, a disturbance magnetic flux detection circuit that detects a disturbance magnetic flux, which is a magnetic flux other than the magnet magnetic flux and is interlinked with the magnetic sensor, and a correction circuit that corrects a result of detection of the magnetic sensor based on a result of detection of the magnet magnetic flux detection circuit and a result of detection of the disturbance magnetic flux detection circuit.

An exemplary encoder assembly includes a substrate, a first encoder, and a second encoder. The substrate has two or more position sensors, each position sensor being configured for detecting a rotary position of a shaft or other rotating element of a machine. The first encoder includes at least one first position sensor of the two or more position sensors. The at least one first position sensor is disposed on the substrate for off-axis alignment with the shaft or other rotating element of the machine. The second encoder includes a second position sensor of the two or more position sensors, the second position sensor being disposed on the substrate for on-axis or off-axis alignment with the shaft or other rotating element of the machine. Each position sensor is configured to detect different or common signal types, and a signal type of the second position sensor excludes optical signals.

Example magnetic sensor system includes a magnet mounted on a rotatable shaft, and a magnetic sensing device in a vicinity of the magnet. The magnetic sensing device includes an angle sensor configured to detect an orientation of a magnetic field generated by the magnet as the rotatable shaft is rotated, a magnetic multi-turn sensor configured to detect a number of turns of the magnetic field generated by the magnet as the rotatable shaft is rotated, a magnetic disk mounted on the rotatable shaft, wherein the disk comprises at least a first track for inducing a change in a magnetic field generated by the magnetic disk, wherein the first track is formed from a plurality of curved segments distributed around the circumference of the magnetic disk, and a first incremental sensor configured to detect changes in the magnetic field induced by the first track as the rotatable shaft is rotated.

A position-measuring device includes a first assembly and a second assembly. The first assembly, installable on a first object, has a profiled element that bears a scale having a first and second measuring graduation. The second assembly, installable on a second object, has a first scanning unit that is movable along a travel path in a measuring direction to scan the first measuring graduation. A position of the first object relative to the second object is therefore measurable. A second scanning unit is mounted on the profiled element so as to enable the second measuring graduation to be scanned, and is positioned in a way that allows the first scanning unit to traverse collision-free along the travel path at a distance spaced apart from the second scanning unit orthogonally to the measuring direction such that a displacement of the scale relative to the first object is measurable.

An encoder includes a disc and a sensor. The disc has a circular surface with a central axis and is rotatable around the central axis. The disc has a slit row provided on the circular surface. The slit row includes slits arranged in a circumferential direction of the circular surface around the central axis and in a radial direction of the circular surface. The sensor is provided opposite to the slit row on circular surface. The sensor has a first light receiver and a second light receiver. The first light receiver is configured to output a first light receiving signal as the slit row rotates along the circumferential direction when the disc rotates around the central axis. The second light receiver is configured to output a second light receiving signal as the slit row moves along the radial direction when the disc rotates around the central axis.

A magnetic-field-based angle sensor system includes a stator component and a rotor component rotatable relative thereto, a magnetic field sensor operating in saturation operation and a magnetic field sensor operating in linear operation, wherein the magnetic field sensor operating in saturation operation is configured to determine a rotation angle of the rotor component relative to the stator component, and wherein the magnetic field sensor operating in linear operation is configured to ascertain an external magnetic stray field acting on the angle sensor system. The angle sensor system further includes a control device configured, based on the ascertained external magnetic stray field, to compensate for a stray-field-dependent measurement deviation in the determination of the rotation angle carried out.

The present disclosure provides an input device and control method thereof. The input device includes a roller module, a relative encoder, an absolute encoder, and a processor. The control method includes: obtaining current angle data outputted by the absolute encoder according to a target phase of at least one signal outputted by the relative encoder; obtaining a current position number corresponding to the current angle data according to the current angle data; calculating a number difference according to the current position number and a previous position number; and outputting the number difference.

A rotation angle detection device for accurately detecting a rotation angle is obtained even when electromagnetic noise due to an electrical component(s) and the like of an electric automotive vehicle is superimposed on detection signals of the rotation angle detection device. The device includes a multi-phase/two-phase transformation unit for converting a plurality of detection signals, each being outputted from rotation detectors in accordance with a rotation angle of a rotating body so as to output transformed signals as two-phase signals; an addition-subtraction calculation unit for generating addition-subtraction signals by mutually performing addition to the two-phase signals and subtraction therefrom; an amplitude correction unit for modifying amplitudes of the addition-subtraction signals in accordance with an amplitude correction value, and for outputting post-correction addition-subtraction signals; and an angle calculation unit for calculating an angle based on the post-correction addition-subtraction signals, and for outputting an angular signal.

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 encoder includes a scale and a sensor relatively movable in a first direction. The sensor includes first and second readers reading a first pattern. The encoder acquires a first position in a first direction by using an output signal from the first reader and acquires a second position in the first direction by using an output signal from the second reader. The encoder acquires a period of the first pattern by using the first and second positions, and acquires first and second shift amounts between the scale and the first and second readers in a second direction orthogonal to the first direction. The encoder produces position information by using the first and second positions, the period and the first and second shift amounts.