Improved means and methods to sense rotation using magnetic field sensors, inductance sensing and capacitive sensing employ a user interface comprising a knob and an integrated circuit containing a magnetic field sensor and inductance measuring circuitry. A permanent magnet and a metal member are attached to the knob, allowing detection of rotation of the knob and when the knob is depressed. A first press is interpreted as an activation command, a subsequent rotation is detected, indicated and stored, a second press is interpreted as a deactivation command and a third press is interpreted as a command to reactivate and automatically select a specific rotational position.

An electromechanical actuator includes a ground arm, an output arm rotatable about an axis of rotation relative to the ground arm and a position sensing arrangement to determine an angular position of the output arm relative to the ground arm. The position sensing arrangement includes a position sensor fixed at the ground arm. The position sensor is configured to sense magnetic reluctance. A sensed portion is located at the output arm proximate to the position sensor. The sensed portion includes a geometric variation in an output arm surface configured to vary a magnetic reluctance sensed at the position sensor as a function of angular position of the output arm relative to the ground arm.

A force sensor including: a first part including a detection coil; a second part positioned opposite the first part and including: a ferromagnetic plate translationally movable relative to the first part to move towards the first part when a force is transferred to the sensor and to reduce reluctance of a magnetic circuit formed by the first and second parts in series with a variable gap; and an electronic detection circuit configured to generate a signal dependent on the reluctance of the magnetic circuit. The ferromagnetic plate is formed by an amorphous metal alloy.

Systems and methods for sensing angular displacement between body segments of users include disposing an electromagnetic transmitting sensor about a first body segment and an electromagnetic receiving sensor about a second body segment. Data related to the magnetic field coupling between the transmitting and receiving sensors can be captured for determining the angular displacement between the first and second body segments.

The invention relates to a sensor arrangement (7) for detecting a position and/or a displacement of a flux element assembly (8) along a longitudinal direction, with a coil assembly (1) and the flux element assembly (8), wherein the coil assembly (1) comprises at least two flat coils (2a, b), wherein the flux element assembly (8) comprises at least two flux elements (9a, b), wherein the at least two flux elements (9a, b) are arranged adjacent to one another in the longitudinal direction and offset in transverse direction, wherein the flux element assembly (8) and the coil assembly (1) are movable and/or displaceable relative to one another in the longitudinal direction, wherein the flat coils (2a, b) are designed, such that an actual inductance (L.sub.1, L.sub.2) of each flat coil (2a, b) is dependent on the actual displacement of the flux element assembly (8) relative to the coil assembly (1), with an evaluation device, which is set up to determine the actual inductance (L.sub.1, L.sub.2) for each flat coil (2a, b) and determine the actual displacement based on the determined actual inductances (L.sub.1, L.sub.2).

A control system (15) for controlling a full bridge converter to compensate the reactive power consumed by an inductive position sensor for a rotor of an electrical machine supported by at least one active magnetic bearing is proposed. The inductive position sensor is supplied by an alternating current source. The control system (15) includes a phase shift determining means (26) to determine a phase shift (S.sub.P) between a supply voltage (V.sub.S) and a supply current (I.sub.S) delivered by the source. A first control loop (22) controls the amplitude (A.sub.C) of a control signal (S.sub.C) from the phase shift (S.sub.P). A second control loop (23) controls the phase of the control signal (S.sub.C). A third control loop (24) controls a voltage reference (V.sub.R). A controlling means (25) controls a full bridge converter according to the control signal (S.sub.C).

A system for detecting a position of a dual solenoid device includes device configured to move between first and second positions, and a controller. The controller has first and second monitoring circuits in operable communication with first and second channels, respectively. The first and second channels are in operable communication with first and second solenoids, respectively. Each solenoid is configured to selectively operate as an active solenoid to move the device when the solenoid and its respective channel are in an active mode, and as a passive solenoid when the solenoid and its respective channel are in a passive mode to passively move with the active solenoid. Each of the monitoring circuits is configured to determine a position of the device when the channel the monitoring circuit is associated with is operating in the passive mode by monitoring an electrical parameter of the passive solenoid associated with that channel.

Systems and techniques are described for measuring displacement of a mass by using an array of beams for scanning a binary intensity pattern disposed on a surface of the mass. Further, systems and techniques are described for measuring displacement of a moving mass by combining (i) information obtained from scanning, using a beam of light, an intensity pattern disposed on a surface of the mass, with (ii) information obtained when a coil interacts with a magnet attached to the moving mass. Furthermore, systems and techniques are described for measuring displacement of a mass by illuminating an intensity pattern disposed on a surface of the mass with an array of beams and monitoring intensity of each of the beams that is redirected by the intensity pattern.

A radial position sensor that measures a radial position of a rotor within a stator is provided. The radial position sensor provides measures the radial position of the rotor along a first axis radial to a rotation axis of the rotor and along a second axis perpendicular to the first axis. The radial position sensor includes four magnetic poles, among which two poles are diametrically opposed along the first axis and two other poles are diametrically opposed along the second axis.

A system comprising: one or more field generating coils configured to generate a magnetic field; a sensor comprising a shell that contains a ferrofluid, the sensor configured to be introduced in proximity to the magnetic field, wherein the ferrofluid causes distortion of the magnetic field when the ferrofluid is in proximity to the magnetic field; and one or more field measuring coils configured to: measure a characteristic of the magnetic field when the ferrofluid is in proximity to the magnetic field; and provide, to a computing device, a signal representative of the measured characteristic of the magnetic field, wherein the computing device is configured to determine one or both of a position and an orientation of the sensor based on the measured characteristic of the magnetic field.