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.

Some embodiments include an absolute displacement detection device configured to calculate, from a plurality of displacement detection signals provided by a plurality of displacement detection mechanisms that detect displacement amounts, an absolute periodic signal having an absolute periodic signal period larger than displacement detection signal periods of the plurality of the displacement detection signals. Other embodiments of related devices and methods are also disclosed.

A motor according to an embodiment includes a motor body, a rotating body, and a magnetic field sensor. The motor body rotates a shaft about the axis line thereof. The rotating body includes a permanent magnet and rotates along with the rotation of the shaft. The magnetic field sensor includes a magnet body having a large Barkhausen effect with the long direction thereof serving as the easy magnetization direction and is positioned to face the permanent magnet when the rotational position of the rotating body is at a given rotational position. The easy magnetization direction of the magnetic body is in a direction along a plane orthogonal to the rotation center line of the rotating body.

A rotary encoder (1) is provided, including a shaft (W) connected to and drivable by an external shaft, a first gear unit (G1) and a second gear unit (G2), each following rotations of the shaft (W). Both gear units (G1, G2) (G1 and G2) are drivable independently of one another by the shaft (W), a first gear stage (G1S1) of the first gear unit (G1) has a first detection unit (E1), and a gear stage (G2S2) downstream of a first gear stage (G2S1) of the second gear unit (G2) has a second detection unit (E2). An evaluation unit derives the angular position from signals of the detection units (E1, E2) and compares the rotations of the first gear stage (G1S1) and the downstream gear stage (G2S2) for plausibility, taking into account a known ratio of the rotation of the first gear stage (G1S1) to the rotation of the downstream gear stage (G2S2).

The power control unit sets a drive interval for driving the sensor by providing power intermittently to the sensor to a first time interval when no change is detected in the sine-wave signal and the cosine-wave signal, sets to the second time interval that is shorter than the first time interval when a change in only one of the sine-wave signal and the cosine-wave signal is detected, and sets to the third time interval that is shorter than the second time interval when a change in one of the sine-wave signal and the cosine-wave signal is detected and then a change in the other is detected.

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.

In a rotation detecting apparatus, a sensor includes a sensor element outputting a measurement value representing rotation of a detection target, and a circuit module. The circuit module includes a rotational angle calculator calculating, based on the measurement value, rotational angle information indicative of a rotational angle of the detection target. The rotational angle calculator generates a rotational angle signal including the rotational angle information. The circuit module includes a rotation number calculator calculating, based on the measurement value, rotation number information representing the number of rotations of the detection target. The rotation number calculator generates a rotation number signal including the rotation number information. An output unit outputs, as an output signal, a series of the rotational angle signal and the rotation number signal. A controller obtains the output signal from the communicator, and calculates, based on the output signal, information about the rotation of the detection target.

The invention relates to a magnetic linear or rotary encoder (1) for monitoring the motion of a body, comprising: an exciting unit (8), which reproduces said motion and has at least one pair of primary permanent magnets (16, 17), which are arranged opposite one another and are magnetically connected to one another by means of a ferromagnetic yoke body (9) and form a measurement field space therebetween; a fine-resolution sensor unit (29; 29′), which is used to determine a fine position value, is arranged in a stationary manner and has a plurality of magnetic field sensors (25, 26, 27, 28); and processing electronics, which evaluate the signals of the fine-resolution sensor unit and have a data memory. Said magnetic linear or rotary encoder is characterised in that a ferromagnetic deflecting body (18) is provided, which deflects at least some of the magnetic field lines of the magnetic field produced by the primary permanent magnets in a direction perpendicular to the magnetisation vector of the primary permanent magnets, that the fine-resolution sensor unit is designed and arranged in such a way that the individual magnetic field sensors of the fine-resolution sensor unit are penetrated by the magnetic field lines deflected by the deflecting body by means of a perpendicular component, that at least the yoke body is made of a thermally treated, ferromagnetic material, and that the fine-resolution sensor unit does not contain a ferromagnetic component.

Methods and systems for measuring multi-turn angular position include a system of N gears meshed with one another, each gear having a unique number of teeth. A first gear is mounted to an input shaft. A set of N angular position sensors are each configured to measure the angular position of a respective gear in the system of N gears within one rotation. A control module is configured to determine an angular position of the input shaft over multiple rotations using the measured angular positions of the N gears.

Provided is an encoder apparatus capable of reducing frequency of maintenance of a battery. An encoder apparatus includes: a position detection system including a detector that detects position information on a mover; an electric signal generator that generates an electric signal in response to movement of the mover; and a battery that supplies at least a part of power consumed by the position detection system in accordance with the electric signal generated by the electric signal generator.