Incremental magnetic encoder

Abstract

Incremental Magnetic Encoder The present invention relates to an incremental magnetic encoder (10) defining an encoder axis (X) and comprising a fixed body and a moving body. One of the bodies, called the first body (21), comprises a first support (33) comprising N arranged magnetic elements. The other body, called the second body (22), comprises: - a second support (41) comprising K*M magnetic elements arranged inhomogeneously along the encoding direction (C1, C2) opposite the N magnetic elements, the K*M magnetic elements forming M groups of K magnetic elements, the initial elements of the M different groups being spaced from each other along the encoding direction (C1, C2) according to a homogeneous pitch P1, the K-1 magnetic elements of each group being spaced from the initial magnetic element of that group according to variable pitches Pi; - at least one magnetic detector disposed opposite the first support (33). Figure for the abstract: Figure 2

Description

Title of the invention: Incremental magnetic encoder FIELD OF INVENTION

[0001] The present invention relates to an incremental magnetic encoder.

[0002] More particularly, the present invention relates to an encoder capable of providing binary logic signals representing increments of the relative position of two elements of the encoder, the two elements being movable relative to each other. Advantageously, such an encoder is applicable in the aeronautical field, for example in an aircraft cockpit.

[0003] Typically, in an application for aeronautical equipment, an angular and / or linear encoder can be used to indicate to an autopilot computer an altitude or speed setpoint that the operator selects by pressing a control button on the encoder. The reliability of the encoder and the information it provides is therefore an essential element of the encoder. The typical requirement for an aeronautical encoder may include one or more of the following: compactness, the ability to perform multiple rotations and / or linear travel, incrementing and detenting capabilities, etc. In order to be certified, the aeronautical encoder must also be able to meet high DAL (Design Assurance Level) safety standards, particularly DAL A.

[0004] In particular, with regard to compactness, an encoder typically has a control button with a diameter between 10 and 100 mm and a length between 5 and 50 mm (typically 0.16 mm x 1.16 mm) and a body with a diameter between 10 and 100 mm and a length between 5 and 100 mm (typically 0.25 mm x 1.50 mm) concealed behind the mounting panel or fixed in front of it. In the latter case, the button encompasses the encoder body, which is fixed to the panel, and allows it to be placed around, or even slightly overlapping, a monitor or screen.

[0005] With regard to the incrementing capability, each notch (or step) constitutes an increment of one unit of rotation or translation. The angular or linear resolution is defined per step (or notch). The number of steps per revolution is on the order of 1 to 32 steps (typically 12 steps). The number of steps in translation is, for example, from 1 to 10 notches (typically 1 notch in each direction to obtain a "push / pull" button with a stable state between the two notches).

[0006] To detect the direction of rotational and / or translational movement, the encoder generally has at least two detectors (for rotation and / or translation) physically offset from each other (typically by an odd number of quarter steps). These two detectors allow the rotational and / or translational movement to be encoded using two bits. Thus, the encoding yields the following successive values: 00, 01, 11, 10 When the encoder rotates and / or translates in one direction, the following successive values ​​are recorded: 00, 10, 11, 01. When the encoder rotates and / or translates in the other direction, the values ​​are recorded. It is therefore possible to determine not only the occurrence of a rotational and / or translational increment (a change of state in one of the bits) but also the direction of rotation and / or translation (by comparing a detected state with the immediately preceding state).

[0007] Regarding the detenting capacity of the encoders, the passage of the encoded detent generally results in tactile feedback that an operator must feel when maneuvering the device. The angular detenting torque can, for example, be on the order of 1 to 700 mN.m (typically 12 mN.m) and the linear detenting force on the order of 0.5 to 20 N (typically 6 N).

[0008] The most complex encoders have rotational and translational encoding and detenting. Rotational encoding and detenting must not be blocked by translational encoding and detenting. In this case, rotational and translational detection and detenting must be able to be used simultaneously without loss of performance. For example, to enter a speed, the driver must simultaneously push the encoder button and turn it to the desired value.

[0009] Finally, in certain cases, to secure the encoder and in particular to guarantee its DAL security level (for example DAL A), the detection (or encoding) functions are at least doubled. STATE OF THE ART

[0010] To meet the aforementioned needs, the encoders used in aeronautical applications are often based on opto-mechanical solutions (optical detection and mechanical detenting) or electromechanical solutions (detection by electrical contact and mechanical detenting) and sometimes magneto-mechanical solutions (magnetic detection and mechanical detenting) or opto-magnetic solutions or even purely magnetic solutions.

[0011] For example, opto-mechanical encoders are described in documents FR 2937129 and FR 2954491. According to these documents, rotational and / or translational detection (encoding) is performed by an optical encoder, while maintaining a stable position (ratcheting) is ensured mechanically by at least one ball pressurized by a spring on a ball track (or cam). Even though these recent innovations meet the needs described above and aim to simplify their implementation, these opto-mechanical and electromechanical encoders remain complex assemblies made up of numerous high-precision parts.

[0012] More generally, current mechanically driven solutions generate friction (e.g., ball against cam) and wear, which limits the lifespan of the device, particularly when plastic parts are used. In encoders In electromechanical systems, detection and detenting are sometimes linked by at least one common mechanical part that serves both as a click and as a detection mechanism via an electrical contact. This contact is often subject to wear and fretting corrosion, thus limiting the device's lifespan. Furthermore, in optomechanical and sometimes electromechanical devices, detection and detenting are decoupled, meaning they result from different solutions and / or phenomena and are physically separated. This decoupling increases the number of parts and, consequently, the risk of misalignment between detection and detenting. In the case of complex and secure encoders, the number of parts is even greater. To ensure good performance and reliability, modern complex encoders require high-precision, and therefore more expensive, components.

[0013] French document FR 2370350 is also known, describing a rotary magnetic encoder with moving magnets in which the detenting and encoding are based on magnetic phenomena. However, the encoder in this document is purely rotary and uses moving magnets that are subject to risks of friction and jamming.

[0014] In summary, electromechanical solutions present the highest risk of fatigue, both in the detenting and encoding stages, because they generate the most friction. Furthermore, the electrical encoding is susceptible to fretting corrosion. These drawbacks reduce reliability and limit the device's lifespan.

[0015] Opto-mechanical and magneto-mechanical solutions retain the risk of fatigue at the level of the mechanical notching.

[0016] Opto-magnetic solutions use different contactless phenomena. These solutions are more cumbersome if a more complex (example: rotary encoder with "push / pull") and secure encoder is desired.

[0017] Finally, known purely magnetic solutions do not meet all of the aforementioned needs and sometimes have a significant size requirement. Summary of the invention

[0018] The present invention aims to provide an incremental encoder that meets all the aforementioned requirements (compactness, ability to perform multiple rotations and / or linear travel, incrementing and detenting capabilities, etc.), while offering frictionless and wear-free detenting and detection (coding) functions, a limited number of parts, simplified assembly, and reduced risks of jamming and misalignment. Furthermore, the incremental encoder according to the invention can be made particularly compact. In addition, the detenting force provided by this encoder can be adjusted with particular precision and ease.

[0019] To this end, the invention relates to an incremental magnetic encoder defining an encoder axis and comprising a fixed body and a movable body relative to the fixed body along at least one encoding direction;

[0020] one of the bodies, called the first body, comprising:

[0021] - a first support comprising N magnetic elements arranged along the coding direction according to a homogeneous pitch PO and defining a magnetic alternation along this direction;

[0022] the other body, called the second body, comprising:

[0023] - a second support comprising K*M magnetic elements arranged in such a inhomogeneous along the coding direction with respect to the N magnetic elements, the K*M magnetic elements forming M groups of K magnetic elements, each of the M groups comprising an initial magnetic element of that group, the initial elements of the M different groups being spaced from each other along the coding direction according to a homogeneous pitch PI, the K-1 magnetic elements of each group being spaced from the initial magnetic element of that group according to variable pitches Pi looped over a predetermined extent along the coding direction

[0024] - at least one magnetic detector disposed opposite the first support and configured to quantify each movement of the moving body according to the coding direction.

[0025] Equipped with these features, the encoder according to the invention makes it possible to implement coding along one of the chosen directions, for example, between the direction of translation and the direction of rotation, while ensuring detenting along the same direction. According to the invention, the coding and the detenting are created by the same magnetic effect between the moving body and the fixed body.

[0026] Thus, the arrangement of these two bodies can be chosen to minimize their mechanical contact. For example, the detailed elements of the fixed and moving bodies described above have no contact with each other. Therefore, these elements operate without friction and without premature mechanical wear. This ensures the encoder's reliability in use and considerably extends its service life, even when plastic parts are used. Furthermore, these elements are limited in number, which allows them to be easily arranged within the corresponding bodies. In particular, the number of magnetic elements on the second body can be reduced compared to that on the first body, while still providing the necessary number of teeth and force. This makes it possible to make the encoder more compact and to reduce the number of parts required for its operation.

[0027] This makes the assembly of the encoder particularly simple and reduces the risks of jamming and misalignment of different parts with each other.

[0028] According to other advantageous aspects of the invention, the encoder comprises one or more of the following features, taken individually or in all technically possible combinations:

[0029] - the second body comprises M magnetic detectors, each detector ma genetics being configured to quantify each movement of the moving body according to the coding direction;

[0030] - the magnetic detector or each magnetic detector is arranged on the second support in a terstice formed between two groups of K magnetic elements;

[0031] - the M groups of K magnetic elements define the same variable pitches Pi;

[0032] - each variable step Pi is defined according to the following relation:

[0033] pi = k^

[0034] where

[0035] L is said predetermined extent;

[0036] k, is a natural number chosen differently for each variable step.

[0037] - within each group, the magnetic elements are spaced in such a way homogeneous between them;

[0038] - at least one magnetic element from one of the M groups of K magnetic elements is arranged between two magnetic elements of another group of K magnetic elements;

[0039] - the second body is the fixed body;

[0040] - the encoding direction corresponds to a translation along the encoder axis or to a rotation around the encoder axis;

[0041] - the moving body is mobile relative to the fixed body in further a direction of additional coding perpendicular to said coding direction;

[0042] - the first body and the second body comprise a plurality of elements ma additional genetic elements arranged according to the additional coding direction on both bodies at least partially opposite. DESCRIPTION OF THE FIGURES

[0043] These features and advantages of the invention will become apparent from the following description, given solely by way of example and not limitation, and made with reference to the accompanying drawings, in which: - [Fig.1] [Fig.1] is a schematic perspective view of a magnetic encoder according to a first embodiment of the invention, the encoder being partially fixed behind a panel forming a dashboard; - [Fig.2] [Fig.2] is an exploded perspective view of the encoder of [Fig.1]; - [Fig. 3] [Fig. 3] presents a partial view of a section along the long plane gitudinal III of the [Fig.l]; - [Fig.4] [Fig.4] is a perspective view of the internal functional elements tionals of the moving body of the [Fig.1], these elements including in particular a translation ring and a rotation ring; - [Fig. 5] [Fig. 5] is a partial cross-sectional view of the translation ring of the [Fig.4] with a fixed body translation ring; - [Fig.6] and [Fig.6] are two diagrams illustrating different options arrangement of magnetic elements on the translation ring of the [Fig.4]; - [Fig.7] [Fig.7] is a cross-sectional view of the rotation ring of [Fig.4] with a fixed body rotation ring; - [Fig.8] The [Fig.8] are two diagrams illustrating different options arrangement of magnetic elements on the rotation ring of the [Fig.4]; - [Fig.9] [Fig.9] is a view analogous to that of [Fig.7] illustrating another example of the realization of the fixed body; - [Fig. 10] [Fig. 10] is a diagram illustrating notching forces and the signals from two detectors obtained in the encoder of the [Fig.l]; - [Fig. 11][Fig. 11] is a schematic perspective view of a ma encoder genetics according to a second embodiment of the invention, the encoder being partially fixed behind a panel forming a dashboard; and - [Fig. 12] [Fig. 12] is a perspective view of the internal functional elements tionals of the moving body of the [Fig.l 1]. DETAILED DESCRIPTION OF THE INVENTION

[0044] FIRST IMPLEMENTATION MODE

[0045] Figure 1 illustrates an incremental magnetic encoder 10 according to a first embodiment of the invention. Preferably, the encoder 10 is mounted in a cockpit for piloting an aircraft.

[0046] The term "aircraft" means any flying machine, such as an airplane, helicopter, or drone, for example. Such an aircraft can be piloted directly from within it. In such a case, the cockpit is advantageously located inside the aircraft. According to another embodiment, such an aircraft is remotely controlled. In such a case, the cockpit is located at a distance from the aircraft and includes, for example, a ground station. In all cases, the aircraft is configured to be piloted by an operator, for example, a pilot, from the cockpit located inside the aircraft.

[0047] According to the invention, the encoder 10 allows the operator to control at least one avionics function. For example, such an encoder 10 can be used by the operator to control an avionics system and is part of a control system for such an avionics system. Alternatively, the encoder 10 is part of a control system for several avionics systems. For example, the encoder 10 according to the invention is part of a system called "Flight Control Unit" (FCU) or "Integrated Standby Instrument System" (ISIS) or "Closer Control Device" (CCD) or "Keyboard Cursor Control Device" (KCCD), etc.

[0048] In the example of [Fig. 1], the encoder 10 is partially integrated into a panel 12. This panel 12 forms, for example, an instrument panel in the aircraft cockpit for one of the aforementioned control systems. In the example of [Fig. 1], the encoder 10 is arranged partially in the front portion 12A of the panel 12 and partially in the rear portion 12B of this panel 12. In particular, in the example of [Fig. 1], the front portion 12A of the panel 12 faces the operator, while the rear portion 12B of this panel faces the interior of the instrument panel. Of course, other arrangements of the encoder 10 relative to the panel 12 or to any other mounting means are also possible.

[0049] With reference to [Fig.2], the encoder 10 comprises a movable body 21, also called in the example of this figure first body, and a fixed body 22, also called in the example of this figure second body.

[0050] The movable body 21 includes a button 31 and a rotor 33.

[0051] The button 31 protrudes from the panel 12 and is arranged in the front portion 12A of this panel 12. The button 31 is movable in translation along an X-axis encoder and in rotation about the X-axis encoder. More specifically, the button 31 is movable in a first coding direction Cl, which in this example corresponds to the direction of translation along the X-axis encoder, and a second coding direction C2, which in this example corresponds to the direction of rotation about the X-axis encoding. Advantageously, the button 31 is movable in each direction along each coding direction Cl, C2. In particular, in the direction of rotation, the button 31 is movable in both clockwise and counterclockwise directions, and in the direction of translation, the button 31 is movable towards the instrument panel and towards the operator. Advantageously, the button 31 defines in particular a button surface 34 which is intended to be oriented towards the operator.This surface 34 therefore represents an external surface of the button 31 which is visible to the operator and can be grasped by the operator.

[0052] The rotor 33 extends along the encoder axis X so as to form a fixed connection with the button 31 at one of its ends. Thus, like the button 31, the rotor 33 is movable along the first encoding direction C1 and along the second encoding direction C2 in each of the aforementioned directions of movement. The rotor 33 forms a support where it receives internal functional elements of the movable body 21, which will be explained in more detail later.

[0053] The fixed body 22 includes a support 41, a cover 42 and a flange 43.

[0054] The flange 43 is for example disposed in a through hole 35 of the panel 12 and allows to support the button 31 and the rotor 33. In the example of [Fig.2], the flange 43 is fixed on the panel 12 while remaining in the rear part 12B of it, using for example screws accessible from the front part 12B of the panel 12.

[0055] The support 41 receives internal functional elements from the fixed body 22 which are intended to cooperate with the internal functional elements of the moving body 21, as will be explained in more detail later. In particular, and as will become apparent later, the internal functional elements of the fixed body 22 are held at a distance from those of the moving body 21 by the support 41. To achieve this, the support 41 is configured to receive at least partially the rotor 33, with the internal functional elements of the moving body 21 carried by this rotor 33.

[0056] The support 41 is, for example, connected to the moving body 21 via a movable link in each coding direction. This link can, for example, be formed at each end of the rotor 33 and have plain bearings, for example polymer bearings or sintered bronze bearings. These bearings preferably have flanges to serve as mechanical stops. According to another example, these bearings are rolling element bearings such as ball bushings. Figure 3 shows, in particular, the bearings 37 connecting the rotor 33 to the second body 22. In the example in this figure, the bearings 37 connect one end of the rotor 33 directly to the support 41 and the other end of the rotor 33 to the support 41 via the flange 43. In this example, the flange 43 is configured to cooperate with the support 41 in order to fix it to the panel 12.

[0057] The cover 42 is intended to protect all the components of the encoder 10 which are arranged in the rear part 12B of the panel 12.

[0058] In the example of [Fig.4] illustrating in more detail the functional internal elements of the moving body 21, the rotor 33 has for example a hollow shaft 45 of cylindrical shape extending along the axis of encoder X.

[0059] With reference to [Fig. 4], the internal functional elements of the moving body 21 comprise a first ring 51, called the translation ring, and a second ring 52, called the rotation ring. Each of these rings 51, 52 is fixed on the shaft 45 along the encoder axis X and remains spaced apart from the other ring 51, 52. In addition, each of these rings 51, 52 exhibits a magnetic alternation: axial in the case of the translation ring 51 and circumferential in the case of the rotation ring 52.

[0060] Figure 5 illustrates the lower part of the translation ring 51 in cross-section. Thus, with reference to Figure 5, the translation ring 51 extends along the encoder axis X and has NI elementary rings 51-1 to 51-N1 arranged side by side, for example by gluing. The number N1 is, for example, between 3 and 20. Each elementary ring 51-1, ... 51-N1 is, for example, made in a single block or from several parallelepiped magnets or arc-shaped magnets. Such a ring elementary can also be derived from a "polymagnet" or a "programmable magnet" called Polymagnets®.

[0061] In order to achieve axial magnetic alternation, in the example of [Fig. 5], these elementary rings 51-1, ..., 51-11 have radial magnetization and are arranged side by side so that adjacent rings are magnetized in opposite directions along the radial axis. This arrangement of the elementary rings forms a DI diagram of the magnetic fluxes illustrated in [Fig. 6] in the case of five elementary rings.

[0062] According to another possible arrangement, axial magnetic alternation is achieved using a Halbach-type arrangement, a D2 diagram of the magnetic fluxes of which is also shown in [Fig. 6]. In particular, according to such an arrangement, the elementary rings are magnetized alternately in the radial and circumferential directions. Furthermore, the direction of magnetization of each elementary ring is chosen so as to concentrate the magnetic field on the surface of the translation ring 51 opposite the internal functional elements of the fixed body 22. In the example of the arrangement shown in [Fig. 4], such a magnetic field is concentrated on the outer surface of the translation ring 51.

[0063] The translation ring 51 has a width L1 corresponding to its extent along the encoder axis X. This width L1 is formed by the sum of the widths of the elementary rings 51-1, ..., 51-NI that make up this translation ring 51. The width of each elementary ring forms a pitch P01. In one embodiment, the elementary rings have the same width. In such a case, the translation ring 51 has a homogeneous pitch P01 that can be determined according to the following relationship:

[0064] P01 = ^|.

[0065] In the example of [Fig. 5], among the elementary rings 51-1, ..., 51-N1, the elementary rings 51-2, ..., 51-N1-1 are arranged between the elementary rings 51-1, 51-NI. The elementary rings 51-2, ..., 51-N1-1 are then called central rings and the elementary rings 51-1, 51-NI are called peripheral rings.

[0066] The rotation ring 52 is illustrated in more detail in [Fig. 7]. This rotation ring 52 also extends along the encoder axis X and has a width L2 (visible in [Fig. 4]) corresponding to its longitudinal extent. Advantageously, the width L2 is greater than the width L1 of the translation ring 51, particularly when the longitudinal extents of all the elementary parts (explained below) are substantially identical. The rotation ring 52, for example, has the same diameter as the translation ring 51.

[0067] The circumferential magnetic alternation of the rotation ring 52 is achieved by a particular arrangement of a plurality of elementary parts 52-1, 52-N2 forming this rotation ring 52, each elementary part 52-1, ..., 52-N2 having, for example, a permanent magnet. Each elementary part 52-1, ..., 52-N2 may, for example, have a substantially parallelepiped shape that is elongated along the encoder axis X. This shape may, for example, be slightly curved to form an arc of a circle around the encoder axis X.

[0068] The elementary parts 52-1, ..., 52-N2 are arranged side by side, for example by gluing, in the circumferential direction. The circumferential extent of each elementary part forms a pitch P02. This is a homogeneous pitch P02 when all the elementary parts 52-1, ..., 52-N2 have the same circumferential extent. This pitch can be expressed in angular form as follows:

[0069] PO2-^.

[0070] As in the case of the elementary rings, each elementary part 52-1, ..., 52-N2 is, for example, made in a single block or from several parallelepiped magnets or arc-shaped magnets. Such an elementary part can also be made from a "polymagnet" or a "programmable magnet" called Po-lymagnets®.

[0071] In the example of [Fig. 7], the elementary parts 52-1, ..., 52-N2 have radial magnetization and are arranged next to each other so that the adjacent elementary parts are magnetized in opposite directions along the radial direction. This arrangement of the elementary parts forms a magnetic flux diagram D3 illustrated in [Fig. 8].

[0072] According to another possible arrangement, a circumferential magnetic alternation is achieved using a Halbach-type arrangement, a D4 diagram of the magnetic fluxes of which is also shown in [Fig. 8]. In particular, according to such an arrangement, the elementary parts 52-1, ..., 52-N2 are magnetized alternately in the radial and circumferential directions. Moreover, as in the previous case, the direction of magnetization of each elementary part 52-1, ..., 52-N2 is chosen so as to concentrate the magnetic field on the surface of the rotating ring 52 opposite the internal functional elements of the fixed body 22. In the example of the arrangement in [Fig. 4], such a magnetic field is concentrated on the outer surface of the rotating ring 52.

[0073] The internal functional elements of the fixed body 22 comprise a plurality of translational magnetic detectors 71, also called first magnetic detectors, a plurality of rotational magnetic detectors 72, also called second magnetic detectors, a translational ring 61, and a rotational ring 62. In the example shown in the figures, these elements 61, 62, 71, 72 are fixed to a inner surface of the support 41 (shown in [Fig.2]) of the fixed body 22. In addition, as mentioned previously, these elements 61, 62, 71, 72 are kept at a distance from the corresponding rings 51 and 52 of the movable body 21.

[0074] Elements 61,71 are shown in more detail in [Fig.5].

[0075] In particular, the translation ring 61 of the fixed body 22 is arranged around the translation ring 51 of the moving body 21 so that the outer surface of the translation ring 51 of the moving body 21 is opposite the inner surface of the translation ring 61 of the fixed body 22. This is particularly visible on [Fig.5] showing a cross-section of the lower part of the two translation rings 51,61.

[0076] Just like the translation ring 51 of the moving body 21, the translation ring 61 of the fixed body 22 extends along the encoder axis X and has, for example, the same axial extent L1 or a different extent. For example, this extent may be less than L1 or greater than L1. In such a case, it is possible to achieve a substantially constant detenting force over the entire translation stroke. The difference in the axial extents of these translation rings 51, 61 represents the translation stroke.

[0077] Furthermore, the translation ring 61 of the fixed body 22 comprises K1*M1 elementary rings 61-1 to 61-K1*M1 arranged side by side at intervals and fixed to a common support, for example by adhesive. Each elementary ring 61-1 to 61-K1*M1 is, for example, analogous to the elementary rings 51-1, ..., 51-N1 explained previously. The elementary rings 61-1 to 61-K1*M1, for example, have the same extent along the encoder axis X. This extent is, for example, equal to that of the elementary rings 51-1, ..., 51-Nl of the moving body 21. Unlike the elementary rings 51-1, ..., 51-NI of the moving body 21, the elementary rings 61-1 to 61-K1*M1 of the fixed body 22 are spaced inhomogeneously along the encoder axis X.

[0078] The number K1*M1 is advantageously strictly less than the number NI. The K1*M1 elementary rings 61-1 to 61-K1*M1 form Ml groups of Kl magnetic elements.

[0079] The Ml groups are spaced apart along the X encoder axis according to a homogeneous pitch PI 1. This homogeneous pitch Pli between the groups is measured, for example, between the first elementary rings of these groups, along the X encoder axis. This homogeneous pitch Pli can be determined according to the following relation:

[0080] Fold =

[0081] Within each group, the Kl-1 elementary rings are spaced from the first ring of that group according to variable steps Pii, here i corresponding to the index of the elementary ring within the corresponding group. This index i is greater than or equal to 2 and less than or equal to Kl. This inhomogeneous pitch Pii is determined according to the following relationship:

[0082] = Where v / çeN* Life I 2, Kl U

[0083] where k{ is a parameter chosen for each i.

[0084] The steps Pii are measured from the first ring of the corresponding group, in a looped manner in the axial extent Ll. In other words, when the value j*P 11+Pil exceeds Ll for a certain i and a certain j for a first time, the corresponding elementary ring is placed at the distance j*Pl 1+Pil-Ll from an edge of the translation ring 61 (left edge in the example of [Fig.5]).

[0085] In the example in [Fig. 5], Ml is equal to 3 and Kl is equal to 3. Thus, a total of 9 elementary rings 61-1 to 61-9 are arranged on the translation ring 61 of the fixed body 22. In this figure, the elementary rings corresponding to the same group are hatched in the same way. Rings 61-1, 61-3, and 61-8, rings 61-4, 61-6, and 61-2, and rings 61-7, 61-9, and 61-5 form the same group of rings. In particular, the first elementary rings 61-1, 61-4, and 61-7 of these groups are spaced by the uniform pitch Pli. Within each group, the second elementary ring is spaced from the first elementary ring by the step P21 and the third elementary ring is spaced from the first elementary ring by the step P31. In other words, for the first group, the 61-3 ring is spaced from the 61-1 ring by the step P21 and the 61-8 ring is spaced from the 61-1 ring by the step P31.

[0086] Advantageously, the total number of notches obtained by the cooperation between the translation rings 51, 61 is equal to Al *M\- The resulting notching pitch is therefore calculated as follows:

[0087] p =.....U.....

[0088] when Ml and NI are coprime (i.e., with no common divisor other than 1, for example Ml = 3 and Nl = 14).

[0089] The number of magnetic translation detectors 71 is advantageously equal to the number Ml of groups of Kl elementary rings. These magnetic translation detectors 71 are arranged along the X-axis, advantageously in gaps formed between different elementary rings. The magnetic translation detectors 71 make it possible to quantify the displacement of the translation ring 51 of the moving body 21 along the encoder axis X. In other words, these detectors 71 make it possible to encode each displacement of the translation ring 51 of the moving body 21 along the encoder axis X by detecting changes in the magnetic flux thanks to the axial magnetic alternation of the elementary rings constituting this translation ring 51. For example, the detectors 71 are offset from each other by the pitch Pli just like the elemental ring groups.

[0090] In the example of [Fig.5], a translational magnetic detector 71 is arranged after the first elementary ring of each group of rings.

[0091] Each magnetic detector 71 has, for example, a Hall effect sensor or a magnetoresistive sensor or a solenoid. In addition, each magnetic detector 71 is connected to an external controller of the encoder 10 by cables 74 visible in [Fig. 3].

[0092] Just like the rotation ring 52 of the moving body 21, the rotation ring 62 of the fixed body 22 extends along the encoder axis X and has, for example, the same axial extent L2. Furthermore, the rotation ring 62 of the fixed body 22 comprises K2*M2 elementary parts 62-1 to 62-K2*M2 arranged inhomogeneously along the circumferential direction on a common support forming a ring. Each elementary part 62-1 to 62-K2*M2 is, for example, analogous to the elementary parts 52-1, ..., 52-N2 described previously.

[0093] The number K2*M2 is advantageously strictly less than the number N2.

[0094] The K2*M2 elementary parts 62-1 to 62-K2*M2 form M2 groups of K2 elementary parts.

[0095] The M2 groups are spaced apart along the circumferential direction according to a uniform angular pitch P12. This uniform pitch P12 between the groups is measured, for example, between the first elementary pieces of these groups, along the circumferential direction. This uniform pitch P12 can be determined according to the following relationship:

[0096] P12 =

[0097] Within each group, the K2-1 elementary parts are spaced from the first part of that group according to variable angular spacings Pi2, here i corresponding to the index of the elementary part within the corresponding group. This index i is greater than or equal to 2 and less than or equal to K2. This variable spacing Pi2 is determined according to the following relationship:

[0098] Pi2 = V^ , where VL-eN* ViG[2,K2]]

[0099] where k / is a parameter chosen for each f

[0100] The Pi2 steps are measured in a looped manner along the circumferential direction. In other words, when the value j*P12+Pi2 exceeds 2æ for a certain i and a certain] for a first time, the corresponding elementary part is placed at the angle j*P12+Pi2-2Æ from a reference point of the rotation ring 62.

[0101] In the example of [Fig.7], M2 is equal to 5 and K2 is equal to 3. Thus, in total, 15 elementary parts 62-1 to 62-15 are arranged on the rotation ring 62 of the fixed body 22.

[0102] In this figure, the elementary parts corresponding to the same group are hatched in the same way. Parts 62-1, 62-2, 62-12, parts 62-4, 62-5, 62-15, parts 62-7, 62-8, 62-3, parts 62-10, 62-11, 62-6, and parts 62-13, 62-14, 62-9 form the same group of elementary parts. In particular, the first elementary parts 62-1, 62-4, 62-7, 62-10, and 62-13 are spaced by the uniform angular spacing P12. Within each group, the second elementary part is spaced from the first elementary part by the angular spacing P22, and the third elementary part is spaced from the first elementary part by the angular spacing P32. In other words, for the first group, part 62-2 is spaced from part 62-1 by the pitch P22 and part 62-12 is spaced from part 62-1 by the pitch P32.

[0103] Advantageously, the total number of notches obtained by the cooperation between the rotation rings 52, 62 is equal to *M2- The resulting angular pitch of notching is therefore calculated as follows:

[0104] P -..........

[0105] when M2 and N2 are coprime (i.e., with no common divisor other than 1).

[0106] The number of magnetic rotation detectors 72 is advantageously equal to the number M2 of groups of K2 elementary parts. These magnetic rotation detectors 72 are arranged in the circumferential direction around the encoder axis X, advantageously in gaps formed between different elementary parts. The magnetic rotation detectors 72 allow the displacement of the ring 52 around the X encoder axis to be quantified. In other words, these detectors 72 allow each displacement of the rotation ring 52 of the moving body 21 around the X encoder axis to be encoded by detecting changes in the magnetic flux thanks to the axial magnetic alternation of the elementary parts constituting this translation ring 51. For example, the detectors 72 are offset from each other by the pitch P12 just like the groups of elementary parts.

[0107] In the example of [Fig.7], a magnetic rotation detector 72 is arranged before the first elementary piece of each group of pieces.

[0108] As in the previous case, each magnetic detector 72 has, for example, a Hall effect sensor, a magnetoresistive sensor, or a solenoid. Furthermore, each magnetic detector 72 is connected to an external controller of the encoder 10 by means of cables 74.

[0109] Figure 9 illustrates another embodiment of the rotating ring 62 of the fixed body 22, which can be combined with the rotating ring 52 of the moving body 21, as explained previously. According to this example, the rotating ring 62 of the fixed body 22 also comprises 5 groups of 3 elementary parts. As in the previous case, these groups are spaced by the angular pitch P12, which is, for example, substantially equal to that described in relation to Figure 7.

[0110] Unlike the previous case, the steps P22 and P32 within each of the M2 groups are adapted so that the set of elementary parts 62-1 to 62-K2*M2 form M2 geometric groupings or poles, each pole comprising K2 elementary parts belonging to different groups. Unlike groups, no elementary part belonging to one pole is arranged between two elementary parts belonging to another pole. Within the same pole, the elementary parts are therefore grouped geometrically, whereas within the same group, the elementary parts can be arranged along the entire available length. Advantageously, there are as many poles as there are groups.

[0111] Furthermore, the poles are equidistant from each other by the angular distance Pex_poie along the circumferential direction. Within each pole, the elementary parts are also equidistant from each other by the angular distance Pin_poie. This latter distance Pin_poie is strictly less than the spacing distance Pexpiede between the poles.

[0112] To achieve this, each step P22 is equal, for example, to 2k / 3 and each step P32 is equal, for example, to 4k / 3. According to this example, the magnetic detectors 72 are placed in the gaps between the poles. In some examples, the elementary parts within each pole can be arranged side by side, without forming gaps between them.

[0113] Figure 10 illustrates an encoding diagram performed by at least one pair of magnetic translational detectors 71 or rotational detectors 72. According to this diagram, one of the magnetic detectors in this pair outputs a true or false signal during the movement of the corresponding ring. This signal is denoted by the reference SI in Figure 10. The other detector outputs a signal S2, which is offset from the signal SI by a fraction of the notching pitch. This signal S2 also consists of true and false values ​​that alternate with the movement of the corresponding ring in the corresponding direction. Finally, Figure 10 also shows a trace S3, which corresponds to the notching force or torque applied during the movement of the corresponding ring in the corresponding direction. This trace S3 is also periodic.

[0114] SECOND METHOD OF IMPLEMENTATION.

[0115] The encoder 110 according to a second embodiment will henceforth be explained with reference to [Fig. 1 1]. The application of this encoder 110 is, for example, identical to that of the encoder 10 explained previously.

[0116] The main difference of the encoder 110 according to the second embodiment lies in the manner of its arrangement in relation to the panel 12. Indeed, as illustrated in [Fig. 11], the encoder 110 according to the second embodiment is arranged entirely in the front part 12A of the panel 12.

[0117] As illustrated in Figure 13, just like the encoder 10 according to the first embodiment, the encoder 110 according to the second embodiment comprises a movable body 121, also called the first body, and a fixed body 122, also called the second body.

[0118] The fixed body 122 is fixed, for example, directly onto the front part 12A of the panel 12. As in the previous case, the fixed body 122 includes a support 141 receiving the internal functional elements of this fixed body 122, as will be explained in more detail later. The support 141 may further include a mechanical stop 143 integrated into one of its ends.

[0119] As in the previous case, the moving body 121 also includes a button 131 and a rotor 133, which is, for example, fixed to the button 131 located at its end. The same end of the rotor 133 is, for example, closed by a cover 134 having a surface facing the operator. The cover 134 is connected to the rotor 133. A washer 135 is fixed to the stationary body 122 at its end. This washer 135 may provide a mechanical stop during the rotation or translation of the moving body 121. This mechanical stop may be damped by means of a return spring or an elastomer component (example material: EPDM). Alternatively, this stop may also be magnetic. In this case, this stop may be achieved by placing a magnet fixed to the stationary body in repulsion and facing a magnet fixed to the moving body. This magnetic stop is inherently damped.This magnetic stop can be independent or part of one of the rings 51, 52, 151, or 152 (in order to optimize the number of parts). For example, in the case of a ring of the moving body using a Halbach-type arrangement, a magnet of the fixed body can be placed in repulsion and opposite the end of this ring, having locally axial or circumferential magnetization. In addition, at each of its ends, the rotor 133 can have bearings 136 intended to cooperate with the fixed body 122 in order to ensure the movement of the moving body 121 along each of the encoding directions, namely a first encoding direction C1 corresponding to the direction of translation along the encoder axis X and a second encoding direction C2 corresponding to the direction of rotation around this encoder axis X, in the example shown in the figures.

[0120] Unlike the previous case, the rotor 133 is intended to at least partially encompass the fixed body 122. In other words, the rotor 133 is intended to be arranged around the support 141.

[0121] As illustrated in [Fig. 12], just as in the previous case, the movable body 121 comprises a translation ring 151, also called the first ring, and a rotation ring 152, also called the second ring. These rings are similar to the rings 51 and 52 described previously. Unlike the In the previous case, the rings 151, 152 according to the second embodiment are arranged on an inner surface of the rotor 133, which then has a hollow rotating shaft as shown in the figure. Each of these rings 151, 152 is fixed to the shaft 145 along the X encoder axis and remains spaced apart from the other ring 151, 152.

[0122] Also analogously to the previous case, the fixed body 122 comprises a plurality of magnetic detectors, a rotation ring and a translation ring (not shown in the figures). Unlike the previous case, the translation ring of the fixed body 122 with the corresponding detectors is arranged in the inner part of the translation ring 151 of the movable body 121 and the rotation ring of the fixed body 122 with the corresponding detectors is arranged in the inner part of the rotation ring 152 of the movable body 121.

[0123] In other words, according to this embodiment, the functional internal elements of the fixed body 122 are arranged on an external surface of the support 141. Thus, according to this embodiment, these elements are arranged opposite the inner surfaces of the corresponding rings 151, 152. Put another way, according to this embodiment, the functional internal elements of the fixed body 122 are received inside the rings 151, 152, while remaining at a distance from them. The operation and respective arrangement of these internal elements are analogous to those described previously in relation to the first embodiment.

[0124] OTHER IMPLEMENTATIONS

[0125] Numerous other embodiments are also possible. In particular, all the features described above in relation to the fixed body (especially in relation to the translation and / or rotation rings of the fixed body) can also be applied to the moving body. In this case, the fixed body may include the features described in relation to the moving body in the preceding embodiments.

[0126] Furthermore, it is clear that the variable pitch explained in relation to the elementary rings / parts can only be applied to one of the translation or rotation rings. In this case, a uniform pitch can be applied to the elementary rings / parts of the other ring to obtain a notch in the desired coding direction. Moreover, any other means of achieving such a notch is also possible. Finally, only one coding direction can be provided with a notch.

Claims

Claims

1. Incremental magnetic encoder (10; 110) defining an encoder axis (X) and comprising a fixed body and a body movable relative to the fixed body in at least one coding direction (Cl, C2); one of the bodies, called the first body (21; 121), comprising: - a first support (33; 133) comprising N magnetic elements arranged along the coding direction (Cl, C2) in a homogeneous pitch PO and defining a magnetic alternation along this direction (Cl, C2); the other body, called the second body (22; 122), comprising: - a second support (41;141) comprising K*M magnetic elements arranged inhomogeneously along the coding direction (Cl, C2) opposite the N magnetic elements, the K*M magnetic elements forming M groups of K magnetic elements, each of the M groups comprising an initial magnetic element of this group, the initial elements of the M different groups being spaced apart from each other along the coding direction (Cl, C2) according to a homogeneous pitch PI, the K-1 magnetic elements of each group being spaced from the initial magnetic element of this group according to variable pitches Pirebouclés over a predetermined extent along the coding direction (Cl, C2); - at least one magnetic detector (71, 72) arranged opposite the first support (33; 133) and configured to quantify each movement of the mobile body according to the coding direction (Cl, C2).;

2. Encoder (10; 110) according to claim 1, wherein the second body (22; 122) comprises M magnetic detectors (71, 72), each magnetic detector (71, 72) being configured to quantify each movement of the moving body according to the coding direction (C1, C2).

3. Encoder (10; 110) according to claim 1 or 2, wherein the or each magnetic detector (71, 72) is arranged on the second support (41; 141) in a gap formed between two groups of K magnetic elements.

4. Encoder (10; 110) according to any one of the preceding claims, in which the M groups of K magnetic elements define the same variable steps Pi.

5. Encoder (10; 110) according to any one of the preceding claims, wherein each variable step Pi is defined according to the relation following: where L is said predetermined extent; kj is a natural number chosen differently for each variable step.

6. An encoder (10; 110) according to any preceding claim, wherein, within each group, the magnetic elements are homogeneously spaced apart.

7. Encoder (10; 110) according to any one of the preceding claims, wherein at least one magnetic element of one of the M groups of K magnetic elements is arranged between two magnetic elements of another group of K magnetic elements.

8. An encoder (10; 110) according to any preceding claim, wherein the second body (22; 122) is the fixed body.

9. Encoder (10; 110) according to any one of the preceding claims, wherein the coding direction (C1, C2) corresponds to a translation along the encoder axis (X) or to a rotation around the encoder axis (X).

10. Encoder (10; 110) according to any one of the preceding claims, wherein the movable body is movable relative to the fixed body in further accordance with an additional coding direction (Cl, C2) perpendicular to said coding direction (Cl, C2).

11. Encoder (10; 110) according to claim 10, wherein the first body (21; 121) and the second body (22; 122) comprise a plurality of additional magnetic elements arranged in the additional coding direction (C1, C2) on the two bodies at least partially opposite.

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