The present disclosure provides a magnetic sensor system for monitoring the position of the rotor relative to the stator for use in electronic motor commutation. The system uses two magnetic sensors with a back bias magnet, the magnetic sensors being configured to detect changes in the magnetic field direction caused by the magnetic field interacting with two moveable targets that are being rotated by the motor shaft. The unique phase shift between the signals measured at each sensor can thus be used to determine the relative position between the stator and the rotor. In this respect, the system makes use of the Nonius or Vernier principle to measure rotational displacement, however, the scale of the encoder is defined by the number of motor pole pairs.

An accurate position sensor that operates over a long range is provided. The position sensor can include a first sensor coil having a first number of periods over a range of motion of a target; and a second sensor coil having a second number of periods over the range, wherein the first number of periods is different from the second number of periods, and wherein the first sensor coil and the second sensor coil are arranged with respect to one another such that the target engages both of them simultaneously. In some embodiments, the first number of periods is one and the second number of periods is greater than one. In some embodiments, the first number of periods is greater than one and the second number of periods is greater than the first number of periods.

An encoder for detecting angular position of a rotor in a motor includes a modular hub, configured to be connected to the rotor, and sensing electronics mounted within an end bell of the motor. The modular hub provides a universal mounting configuration for connecting different configurations of the encoder to the motor. The modular hub includes a mounting portion and sensor face on which different elements for sensing may be mounted. The elements may include polarizing tape to reflect polarized light, magnets generating a magnetic field, or ferrous teeth configured to interact with a magnetic field. The sensing electronics include sensing devices corresponding to the elements mounted on the sensor face. The sensing devices may be a paired light emitter/receiver, magnetic sensors, or a paired magnetic field generator/sensor. The sensing electronics convert the sensed signals to uniform feedback data for the motor controller regardless of the encoder configuration.

A method of detecting the angular positions of blades of a rotor wheel of a turbine engine, in which the turbine engine has first and second rotor wheels including respective first and second numbers of blades regularly distributed around their circumferences, includes: detecting the passage of each blade of the first wheel past a first sensor; detecting the passage of each blade of the second wheel past a second sensor; calculating the time intervals between the passage of a blade of the first wheel and the passages of each of the blades of the second wheel; and determining the relative angular position of each blade of the first wheel relative to the angular positions of the blades of the second wheel, the first number and the second number being distinct and mutually prime.

This application relates to an absolute position detection device and detection method of a rotating body using a magnetic material. The device may include magnets coupled to a rotating body and configured to rotate together and having n pole pairs, wherein n is a natural number and (n+1) magnetic materials arranged adjacent to the magnets, spaced apart from each other by a predetermined interval, and configured to rotate together with the rotating body. The device may also include a first Hall sensor spaced apart from the magnets, installed to allow the magnetic materials to rotate in a space between the first Hall sensor and the magnets and configured to output a first signal based on the magnets when the magnetic materials approach the first Hall sensor. The device may further include a controller configured to measure an absolute position of the rotating body using the first signal.

This application relates to an absolute position detection device and detection method of a rotating body. In one aspect, the device includes first row magnets coupled to a rotating body to rotate together and having n pole pairs, and second row magnets coupled to the rotating body to rotate together and having (n+1) pole pairs. The device also includes a first Hall sensor installed adjacent to the first row magnets and configured to detect a change in magnetism according to rotation of the first row magnets. The device further includes a second Hall sensor installed adjacent to the second row magnets and configured to detect a change in magnetism according to rotation of the second row magnets. The device further includes a controller configured to measure an absolute position of the rotating body using signals output from the first and second Hall sensors.

A steering angle detecting apparatus includes a steering angle sensor and a diagnostic unit. The steering angle sensor includes two relative steering angle detectors and an absolute steering angle processor. The two relative steering angle detectors detect a plurality of two relative steering angles. The absolute steering angle processor calculates absolute steering angles. The diagnostic unit determines whether an angular signal indicating an absolute steering angle of the absolute steering angles is outputted from the absolute steering angle processor. The diagnostic unit stores a latest absolute steering angle, determines which of the two relative steering angle detectors outputs one of the two relative steering angles, and, where one of the two relative steering angle detectors is determined as outputting the one of the two relative steering angles, update the latest absolute steering angle by adding outputted one of the two relative steering angles to the stored latest absolute steering angle.

There is provided a displacement measuring device that minimize unnecessary power consumption and improves power efficiency. A displacement measuring device includes a main scale and a detection head that is provided in such a manner as to be relatively displaceable to the main scale and outputs a periodic signal having a phase to be changed according to relative displacement to the main scale. The detection head outputs, as the periodic signal, a coarse scale signal having a coarse period and a fine scale signal having a fine period. A coarse phase detector calculates, from two pieces of phase information acquired from the coarse scale signal, the average phase of the coarse scale signal. A fine phase detector calculates, from four pieces of phase information acquired from the fine scale signal, the average phase of the fine scale signal. The coarse phase detector calculates the average phase of the coarse scale signal from the two pieces of phase information and, then, stops operating without the completion of the operation of the fine phase detector.

A position sensing arrangement for sensing the position of a revolute joint of an articulated structure. The position sensing arrangement comprises a disc and a magnetic sensor assembly. The disc comprises a first magnetic ring with m magnetic pole pairs, and a second magnetic ring with n magnetic pole pairs, where m and n are co-prime, and a mounting arrangement by which the disc is mountable to a magnetisation jig during manufacture and the articulated structure during operation, the mounting arrangement permitting the disc to be mounted to the magnetisation jig and articulated structure in a single orientation only. The magnetic sensor assembly comprises a first magnetic sensor array for detecting the magnetic pole pairs of the first magnetic ring, and a second magnetic sensor array for detecting the magnetic pole pairs of the second magnetic ring.

A magnetic encoder having a plurality of rows of magnetic tracks and capable of detecting an absolute angle is easily producible with higher accuracy. The magnetic encoder includes: a core member of annular shape having a bending plate portion that bends and extends from an edge of a track formation surface; and two or more rows of magnetic tracks arranged adjacent to each other on a magnetic member provided on the track formation surface, each track having N poles and S poles alternately magnetized thereon. The magnetic tracks include a main track that has a largest number of magnetic poles and is used for calculating an angle, and a sub track used for calculating a phase difference from the main track. The main track is located on a side closer to the bending plate portion than the sub track.