Moving Magnet Technologies (mmt)

Moving Magnet Technologies

Mmt Sa

Moving Magnet Technologies (s.a.)

Moving Magent Technologies

Didier Frachon

Pierre Gandel

Claude Oudet

Gérald Masson

Daniel Prudham

Thierry Dorge

Nikola Jerance

Stéphane Biwersi

Michaël Delbaere

Stephane Biwersi

Richard Arlot

Christophe Besson

Bruno Cavallier

Didier Angleviel

Mickaël Delbaere

Nicola Jerance

A position sensor, designed, in particular, for detecting torsion in a steering column, includes a first magnetized magnetic rotor structure comprising a plurality of magnets, two flux-collecting components, which define at least one air gap in which at least one magnetically sensitive element is positioned. Each collecting component has at least one primary collecting zone extended by at least one extension having at least one secondary collecting zone. The secondary collecting zones end in flattened shoes that form the two poles of the air gap. The transverse mid-plane of the air gap intersects at least one of the extensions.

Position sensor, designed in particular for detecting torsion in a steering column

A position sensor, in particular, intended for detecting the torsion of a steering column, includes a first magnetized rotor structure comprising magnets, a second stator structure comprising two rings extended by teeth that are axially oriented and interlocked, and a third stationary collector structure including two flux collection parts that define at least one air gap in which at least one magnet-sensitive element is placed. The flux collection parts and the ring gears define a magnetic permeance independent of the relative radial and angular position of the second stator structure with respect to the third collector structure. The collection parts comprise an angular collection sector and a primary collection zone continued by a prolongation having a secondary collection zone. The secondary collection zones end in flat extensions forming two poles of the air gap. The transverse median plane of the air gap intersects at least one of the prolongations.

Position sensor, in particular intended for detecting the torsion of a steering column

The disclosure relates in particular to a method for parameterizing a system for measuring an absolute position, the system including a permanent magnet, at least one probe that is mobile relative to the magnet over a given path, and a controller providing position information calculated on the basis of the arctangent of the ratio, wherein a correction coefficient G is assigned, between the output signals of the probe, wherein the signals are pseudo-sinusoidal and squared. The method includes an optimization operation that involves selecting the value of the coefficient G that minimizes the errors of the measurement system resulting from the pseudo-sinusoidal character of the signals output from the probe.

Position sensor

The present disclosure relates to a magnetic position sensor with field direction measurement and a flux collector. The disclosure proposes to measure two magnetic induction components at one and the same point, harmonizing the amplitude of the two magnetic induction components using flux collectors so as to have a ratio of the amplitudes of these two components close to one. For this purpose, the disclosure provides a contactless position sensor including at least one permanent magnet, emitting a magnetic field, at least one detection element sensitive to the direction of the magnetic field, and at least one pair of flux collectors, the permanent magnet being capable of moving in a direction of displacement and having a direction of magnetization that can be continuously varied according to the direction of displacement. Each flux collector has at least one portion, provided with an end, extending substantially along the direction of displacement of the magnet. The ends of a pair of flux collectors define a gap oriented along the direction of displacement of the magnet. The detection element is positioned outside the gap and substantially equidistant from the ends.

Magnetic position sensor with field direction measurement and flux collector

The disclosure relates to a contactless magnetic sensor for measuring the angular or linear movement of a ferromagnetic target. The purpose of the disclosure is to make a position sensor having reduced dimensions and capable of detecting a piece of position information as soon as the sensor is powered without degrading the performance thereof. To this end, the disclosure relates to a mobile sensor that includes at least one permanent magnet, at least one ferromagnetic member at least one magnetically sensitive member, the permanent magnet having an upper surface opposite the ferromagnetic target, wherein the permanent magnet has a substantially cylindrical or parallelepiped shape and includes a cavity, the ferromagnetic member being arranged inside the cavity and the magnetically sensitive member being arranged inside the cavity above the ferromagnetic member and below the upper surface of the magnet.

Linear or rotary position sensor with a permanent magnet for detecting a ferromagnetic target

The invention relates to a contactless magnetic sensor for detecting a linear or angular position, comprising a moveable ferromagnetic element () the position of which is detected, and a stator assembly () itself, comprising two ferromagnetic parts (), defining with the moveable ferromagnetic element () two respective air gaps (), a permanent magnet () and a magneto-sensitive element () subjected to a magnetic field that depends on the position of the moveable ferromagnetic element () and designed to deliver a measurement signal that depends on the magnetic field to which it is subjected. According to the invention, the two ferromagnetic parts () define therebetween a third air gap (), the permanent magnet () being rigidly connected only to the first ferromagnetic part () and the magneto-sensitive element () being placed in the third air gap ().

Position sensor using a moveable ferromagnetic element

The invention relates to an angular or linear magnetic position sensor that comprises a mobile member including at least one magnet () having a magnetization direction that varies linearly along the movement direction of the magnet in a surface defined by said movement direction and in a normal direction, at least four magneto-sensitive elements (and) and at least one processing circuit () providing a signal based on the absolute position of the mobile member, characterized in that a first set of magneto-sensitive elements () and () are located at a same point, the first couple of magneto-sensitive elements () being spatially offset from a second couple of magneto-sensitive elements () along the movement direction, and in that the magneto-sensitive elements (and) measure the tangential component of the magnetic field while the magneto-sensitive elements (and) measure the normal component of the magnetic field in order to provide, after algebraic combination of the components taken in pairs, two sinusoidal signals substantially having an electrical phase shift of 90&#xb0;.

Angular or linear magnetic position sensor not sensitive to external fields

An angular position sensor includes a moving element consisting of at least one essentially cylindrical permanent magnet turning about it axis, at least two magnetosensitive elements and at least one processing circuit furnishing a signal dependent on the absolute position of the moving element The magnetosensitive elements are located essentially at the same point and in that they measure the tangential component of the magnetic field and the radial and/or axial component of the magnetic field for furnishing 2 sinusoidal signals that are essentially 90&#xb0; out of phase.

Magnetic angular position sensor including an isotropic magnet

The invention relates to a magnetic angular or linear sensor including at least one permanent magnet defined in a cylindrical (r, Q & z) or Cartesian (x, y & z) coordinate system and at least two magneto-sensitive elements, in which the magnet can move in relation to said two magneto-sensitive elements. The invention is characterized in that at least one dimension of the magnet varies as a non-constant function and in that the magnetization of the magnets is oriented in a single direction, i.e. x, y or z in the case of a magnet defined in a Cartesian coordinate system or r, Q or z in the case of a magnet defined in a cylindrical coordinate system.

Rotary or linear position sensor having a variable magnet profile

A variable reluctance analog position device designed to determine the position variation of a target made from a ferromagnetic material. The device includes at least one magnet, the target and the magnet defining a gap therebetween. A magnetosensitive element detects induction variation produced in the gap by relative movement of the target relative to the magnet. The magnet is magnetized in a direction essentially perpendicular to the front surface of the magnet, which defines one edge of the gap. The magnet includes a cavity open at the front surface thereof and the magnetosensitive element is housed in the cavity. Moreover, the target is provided with a specific geometric configuration determined such that the induction variation according to the position of the target corresponds to a pre-defined function.

Variable reluctance position sensor

Variable-reluctance position sensor

An angular-position magnetic-sensor device includes at least one stator and one rotor. A space between said stator and said rotor, defining over substantially 360&#xb0;, is a main air gap including at least two movable magnetic poles of alternating polarities. The stator is provided with at least one secondary air gap in which there is placed at least one magnetosensitive element. The stator is composed of two pole shoes having angular widths that are substantially equal to 120&#xb0; and 240&#xb0; respectively, and the two magnetic poles each have an angular width substantially equal to 120&#xb0;.

Angular position magnetic sensor device

The invention concerns a position sensor, designed in particular for detecting a steering column torsion, consisting of a first magnetic structure including a plurality of magnets and a second magnetic structure including two ferromagnetic rings () having a plurality of teeth () and defining an air gap wherein is placed at least a magneto-sensitive element (), the two magnetic structures being respectively integral with two parts in relative rotation. The invention is characterised in that the two ferromagnetic rings () are nested and have each a substantially tubular part forming axially oriented teeth () connected by a flux-closing zone (), the detecting air gap being delimited by said flux-closing zones.

Position sensor, designed in particular for detecting a steering column torsion

A magnetic position sensor, linear or rotary, including a stator and at least a mobile part along at least a direction OX, with an effective stroke Xc. The stator includes at least two components made of soft magnetic material defining at least a secondary air gap in which is housed at least a magneto-sensitive probe. Each stator part component has a length Xs in the direction OX not less than Xc. The magnets of one mobile part are extended over at least one edge by a mobile ferromagnetic component having a thickness e, in the direction of a magnetization of one magnet, such that 0.1 L<e<0.9 L, L being a length of the magnet in a magnetization direction, and moving parallel to the stator ferromagnetic components at a constant minimum distance and having a magnetization perpendicular to OX and a length in the direction of displacement OX not less than Xc.

Contactless position sensor with optimized magnetic volume and magneto sensitive probe

An electromagnetic actuator including a fixed stator having two poles. The stator includes one or two excitation coils. The actuator further includes a mobile part provided with thin permanent magnets magnetized along an air gap direction. The mobile member includes at least two independent elements which are each mobile along directions parallel to the air gap plane intersection and the fixed stator median plane, in opposite directions. Each of the mobile parts has three thin magnets alternately magnetized, which are either integral or not with a yoke made of soft material. The thin magnets of the mobile elements are magnetized along a direction opposite to the corresponding thin magnets of the second mobile element or of the adjacent element, the yokes defining with a fixed stator part a yoke.

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Besancon, France

Didier Frachon