EP3664975A1

EP3664975A1 - Capacitive casing element for robot, robot provided with such a casing element

Info

Publication number: EP3664975A1
Application number: EP18749762.3A
Authority: EP
Inventors: Christian Neel; Yacine CHAKOUR; Didier Roziere
Original assignee: Fogale Nanotech SA
Current assignee: Fogale Nanotech SA
Priority date: 2017-08-10
Filing date: 2018-07-30
Publication date: 2020-06-17
Also published as: US20200368924A1; JP2020529933A; CN111065496A; FR3070022A1; WO2019030042A1; KR20200039694A; FR3070022B1

Abstract

The invention relates to a casing element (100) for a robot, said casing element (100) comprising: - at least one capacitive electrode (102), termed a measurement electrode, intended to be biased to a first AC electric potential that is different from a ground potential, at a working frequency; - at least one electrode (104), termed a guard electrode, arranged beneath said at least one measurement electrode (102) and intended to be biased to an AC electric potential, termed the guard potential, that is identical or substantially identical to said first potential at said working frequency; and - at least one dielectric layer (106), termed a central dielectric layer, arranged between said at least one measurement electrode (102) and said at least one guard electrode (104). The invention also relates to a robot provided with at least such a casing element.

Description

"Capacitive cladding element for a robot, robot equipped with such a cladding element"

Technical area

The present invention relates to a capacitive cladding element for a robot. It also relates to a robot equipped with such capacitive dressing element (s).

The field of the invention is, in a nonlimiting manner, that of the field of robotics, in particular the field of industrial robotics or service robots, for example medical or domestic, or collaborative robots, also called "cobots" ".

State of the art

Industrial or domestic robots, in particular cobots, generally comprise a body on which is fixed a functional head, in the form of a tool or a tool holder, allowing them to perform one or more tasks in an environment.

In order to be able to use or develop a robot or co-bot, such as for example a robotic arm, in an environment comprising humans and / or objects, or in cooperation with humans, it is necessary to equip it with a capacity detection of these humans and objects in its environment to avoid any risk of accident. A recent solution for providing this detection capability consists in equipping a robot with capacitive sensors sensitive to approach or contact.

However, there are many old robots, still active, that have not been equipped with detection capability at the time of their design / manufacture. It is therefore necessary to find a solution to equip, a posteriori, these robots with a detection feature, in a simple, inexpensive, and time-consuming manner.

In addition, robots are tools with a long life span. Therefore, for robots that have detection functionality, there is also a need for replacement of skin elements, while maintaining this detection feature. An object of the present invention is to meet at least one of these needs.

Another object of the present invention is to provide a capacitive cladding element that can be used to retrofit an existing robot with capacitive detection functionality in a simple, fast and inexpensive manner.

Another object of the present invention is to propose a capacitive cladding element that can be used to replace, in a simple, fast and inexpensive manner, a cladding element of a robot equipped with a capacitive detection feature while retaining said functionality.

Presentation of the invention

At least one of these goals is achieved with a robot cladding element, in particular designed to be positioned on a segment or articulation of a robot instead of or in addition to a cladding element of said robot, said covering element comprising:

at least one capacitive electrode, referred to as a measurement electrode, intended to be polarized at a first alternating electric potential different from a ground potential at a working frequency,

at least one so-called guard electrode, disposed under said at least one measuring electrode, and designed to be biased to an alternating, so-called guard, identical or substantially identical electrical potential to said first potential at said working frequency, and

at least one so-called central dielectric layer disposed between said at least one measuring electrode and said at least one guard electrode.

Thus, the present invention provides a trim element including integrated capacitive sensing functionality. The dressing element according to the invention makes it possible to provide capacitive detection functionality in a simple, fast and inexpensive manner to a robot, which initially does not have such a functionality. In addition, the detection and guard electrodes As part of the skin element, it is not necessary to modify the architecture of the robot.

In addition, the dressing element according to the invention can be used to replace a dressing element of a robot already having detection functionality, without disturbing this detection function. The maintenance and maintenance of the cladding elements of a robot already equipped with a capacitive detection feature becomes simple, fast and avoids a long and costly immobilization of the robot. In the present application, two alternative potentials are identical at a given frequency when they each comprise an alternating component identical or similar to this frequency. Thus, at least one of the two potentials identical to said frequency may further comprise a DC component, and / or an AC component with a frequency different from said given frequency.

Similarly, two alternative potentials are different at the working frequency when they have no alternative component identical or similar to this working frequency.

In the present application, the term "ground potential" or "general ground potential" denotes a reference potential of the electronics, the robot or its environment, which may be, for example, an electrical ground or a ground potential. This ground potential can correspond to an earth potential, or to another potential connected or not to the earth potential.

It is also recalled that, in general, objects which are not in direct electrical contact with a particular electrical potential (electrically floating objects) tend to be polarized by capacitive coupling to the electric potential of other objects present in their environment, such as for example earth or electrodes, if the overlapping surfaces between these objects and those of the environment (or the electrodes) are sufficiently large.

In the present application, "object" refers to any object or person that may be in the environment of the robot.

By "robot" is meant any robotic system, and in particular a robotic arm, a wheeled vehicle such as a trolley with an arm or a manipulator system, or a humanoid-type robot or provided with moving members such as limbs.

According to a particularly advantageous characteristic, the covering element according to the invention may further comprise at least one so-called external dielectric layer disposed on the measurement electrode or electrodes.

Such an outer layer protects the measuring electrodes against mechanical aggression, dirt and liquids, and thus increases the service life of the measuring electrodes.

Such an outer layer may be a layer attached to the measurement electrodes, without the presence of air or empty space between the measurement electrodes and said outer layer: thus the measurement electrodes, and consequently the capacitive detection, are not disturbed by capacitances due to parasitic coupling between the dielectric outer layer and the mass (especially if this outer layer has a high dielectric permittivity).

For example, such an outer layer may be a plastic layer, a layer of varnish, a layer of glue, or any other material or dielectric coating.

Alternatively, such an outer layer can be independent and disassembled / removed at will.

It may for example be a rigid shell. It can be carried out for example by molding or by thermoforming.

According to one embodiment, the covering element may comprise a rigid, semi-rigid or flexible outer layer, and a central layer in the form of a separate element shaped to fit into the outer layer, and comprising on its faces, respectively, said at least one measuring electrode and said at least one guard electrode.

The central layer may be, or comprise, a rigid or semi-rigid plastic material, shaped for example by molding or thermoforming. The measurement and guard electrodes can be made by deposition or projection as described above on the already shaped core layer. Thus, the cladding element is a double shell structure, with an outer shell (the outer layer) that provides the mechanical protection and the central layer that supports the electrodes. According to another particularly advantageous characteristic, the covering element may comprise a so-called support layer, arranged under the one or more guard electrodes, and designed to come into contact with a surface of the robot.

Such a support layer makes it possible to protect the at least one guard electrode, but also to isolate it electrically from a surface on which the covering element is positioned.

The backing layer may be a continuous layer, or formed by a discrete set of support elements, such as studs or pins.

The backing layer may be dielectric, particularly when the surface of the robot on which it comes into contact is electrically conductive.

The backing layer may be glued to the core layer or to the at least one guard electrode, with or without a void space. Advantageously, the support layer may be made of a locally deformable, flexible and / or elastic material, such as a foam.

Such a flexible backing layer allows on the one hand damping external shocks and on the other hand to absorb surface differences / discontinuities present on a surface of the robot on which the cladding element is positioned. This feature is particularly interesting when the cladding element is in the form of an additional piece, or piece of trim, intended to be positioned on an original trim piece of the robot. The backing layer may comprise openings, or recesses, provided opposite electrical / electronic components of the covering element, such as, for example, detection electronics, wire links, etc. so as not to apply stress on said components. The backing layer may also be rigid or semi-rigid or flexible. In this case, it can be arranged, for example, to maintain a flexible and / or resilient central layer in position and in shape against a rigid or flexible outer layer.

Advantageously, the covering element may consist of layers (in particular the outer layer, the central layer and the backing layer) arranged so as to optimize the thermal conductance. This can be achieved in particular by using materials with high thermal conductivity, and / or by assembling them so as to optimize the thermal contact (for example by avoiding the air spaces between materials). The optimization of thermal conductance is important not to excessively degrade the heat dissipation generated by the robot's organs. Advantageously, the cladding element according to the invention may comprise a positioning means, or a marker, for mounting said cladding element in a determined or determinable position and orientation on a part of the robot.

Such positioning means may be any element that can constitute a positioning and orientation mark for positioning the covering element on a part of the robot, such as a segment or articulation of the robot.

Such a positioning means may also be any element with a guiding function which imposes an implementation in a particular and determined position of the cladding element on the robot.

For example, such a positioning means may be a specific form of the cladding element, in particular a specific shape of the section of said cladding element.

Alternatively or in addition, such a positioning means may be: a visual cue, such as positioning and orientation marking; and or

a mechanical marker, such as a pin, a polarizer, a tongue or an opening for positioning and orientation; and or

a fastening means of the screw type, or clips, etc. ; and or - A complementary mechanical interface or adapted to a mechanical interface of the robot.

The positioning means is an important element of the invention since it makes it possible to position the cladding element in a determined position on the robot, and thus the position of the measurement electrodes is known in the robot's reference system. But the knowledge of the position of the electrodes is essential to exploit their measurements effectively. The cladding element may preferably comprise a plurality of measurement electrodes, in particular arranged in a matrix configuration.

In addition, the covering element according to the invention may comprise an individual guard electrode for each measuring electrode.

Alternatively, the covering element according to the invention may comprise a guard electrode common to a plurality of measurement electrodes, in particular to all measuring electrodes. Such a common guard electrode may form a guard plane common to many, in particular to all, the measurement electrodes.

Such a guard plane can also be used as a shielding layer for the electrical / electronic components in the robot, so as to ensure the electromagnetic compatibility between the robot and its environment.

According to one embodiment, the covering element, or at least one layer chosen from the central layer, the outer layer and the support layer, can be shaped to obtain the desired shape. The modeling can be carried out for example by thermoforming, molding, etc.

Alternatively, the covering element, or at least one layer selected from the central layer, the outer layer and the backing layer, can be printed by 3D printing. At least one measuring electrode, respectively at least one guard electrode, can be deposited on the core layer by spraying metal particles, using a mask, or by screen printing or by ink jet.

When, the covering element comprises a single guard electrode, forming a guard plane, said guard electrode can be obtained by depositing a conductive layer, for example by painting.

Each of these deposition steps may be prior to or subsequent to a shaping / modeling step of the core layer, if any.

According to one embodiment, the dielectric core layer may be in the form of a double-sided printed circuit.

In this case, according to an advantageous configuration, the measurement electrode or electrodes may be disposed on one side of said printed circuit, and the one or more guard electrodes may be arranged on the opposite face of said printed circuit. Thus, the dielectric forming the printed circuit forms a support layer for the measurement and guard electrodes.

The measurement and guard electrode (s) can then be produced by conventional techniques for producing printed circuits, such as photolithography and etching.

The printed circuit can be made on a flexible polyimide substrate. It can also be performed on an extensible or deformable substrate, for example by thermoforming, to generate surfaces with several radii of curvature (spherical, ...).

The printed circuit board may be bonded to the outer layer so that there is no gap between the printed circuit and the outer layer.

The bonding may be thermal bonding or bonding by use of an adhesive product.

The printed circuit may comprise a multitude of pins protruding from the face comprising the at least one guard electrode, and forming the support layer.

According to another embodiment, the measurement electrodes and the guard electrodes can be made on separate substrates, stacked possibly with a dielectric insert. In this case, the central layer may consist of one or two layers of these stacked substrates, and any interlayer.

This or these substrates may be single-sided printed circuit substrates, or any other type of substrate for supporting electrodes, such as for example deformable substrates by thermoforming, elastic, flexible, textile ...

Of course, these embodiments can be combined. It is for example possible to have measurement electrodes made with a printed circuit and one or more guard electrodes made by a deposition technique on one face of the central layer.

Furthermore, in general, the central layer may be composed of a plurality of layers of materials

The covering element according to the invention may further comprise at least one detection electronics configured to measure a signal relating to a coupling capacitance, referred to as the electrode-object capacitance, between at least one measurement electrode and a surrounding object.

Such detection electronics are well known in the state of the art for capacitive sensing.

According to an exemplary embodiment, at least one detection electronics may comprise a charge amplifier configured to provide an output voltage representative of the capacitance between a measurement electrode and a surrounding object.

The covering element according to the invention may comprise a detection electronics dedicated to each measuring electrode.

Alternatively, or additionally, the covering element according to the invention may comprise a detection electronics that is common to several or all measurement electrodes. In this case, said detection electronics may further comprise scanning means for interrogating said measuring electrodes individually or in groups. Such a scanning means may for example comprise a switch connecting the charge amplifier to each of the measuring electrodes in turn. According to a particularly advantageous configuration, the covering element according to the invention may comprise several detection electronics groups, distributed on said dressing element, and distant from each other.

This configuration makes it possible to better manage cases of partial damage to the covering element according to the invention. Indeed, in this configuration, when a portion of the trim element is damaged, the other parts of the element continue to operate and provide the capacitive sensing functionality.

Each group of detection electronics (s) may comprise one or more detection electronics. Each detection electronics may be dedicated to a measurement electrode or to a group of several measurement electrodes.

At least one detection electronics can be arranged on a separate electronic board. This separate electronic card may be an independent card, secured or not to the dressing element, and connected to the dressing element by a connection interface, in particular wired or in the form of a dye formed by the dielectric core layer supporting conductive tracks.

According to one embodiment, at least one detection electronics can be placed between the outer layer and a guard electrode.

In this embodiment, the detection electronics can be arranged on a separate electronic card. The measurement electrodes and the guard electrodes can be made on separate substrates. The substrate with the guard electrode can be arranged to completely or partially cover the detection electronics. Alternatively, or in addition, at least one detection electronics can be made by a part of a printed circuit supporting measurement and / or guard electrodes, at the periphery of these electrodes. At least one detection electronics may be disposed on the core layer.

In particular, when the central layer is formed by a printed circuit, at least one detection electronics can be provided on one face of said printed circuit.

Alternatively or additionally, at least one detection electronics may comprise at least one element disposed on the central layer (such as a charge amplifier), and at least one element disposed on a separate electronic circuit board (such as demodulation elements , filtering, scanning ...).

According to an exemplary embodiment, at least one detection electronics can be arranged on the same side as the at least one guard electrode, with respect to the central layer.

This exemplary embodiment allows good protection of the detection electronics, in particular external shocks.

Alternatively, or in addition, at least one detection electronics can be arranged on the same side as the at least one measuring electrode, with respect to the central layer. This exemplary embodiment makes it possible to keep said detection electronics at the guard potential by the at least one guard electrode, and thus to avoid leakage capacitances or disturbances, which can degrade the capacitive detection functionality. According to a particularly advantageous characteristic, at least one, in particular each, detection electronics can be kept at the guard potential by a wall, or a cover, or a guard volume polarized (e) to the guard potential. Thus, the detection electronics is protected from leakage capabilities, and more generally electromagnetic disturbances, which degrade the detection functionality.

This embodiment is particularly advantageous when the detection electronics is positioned on the side of the guard relative to the central layer, or independently of the covering element according to the invention.

When the detection electronics is arranged on the side of the measuring electrodes, and facing one or more guard electrodes, it is not necessary to use a wall (or a cover or volume or layer) of additional guard because said measurement electronics is already guarded by the at least one guard electrode, at least with respect to the couplings with the internal elements of the robot. The guard electrode then constitutes the guard wall of the electronics.

It should be noted that a guard wall may also be formed by a conductive layer of the detection electronics circuit.

The covering element according to the invention may further comprise at least one wired and / or wireless connection interface.

This connection interface may for example be arranged to receive at least one alternating electric potential. This alternative electric potential can:

- correspond to the first alternative potential, the guard potential, or both;

- be used to obtain the first AC potential, the guard potential, or both.

This alternating electric potential can for example be derived from a master oscillator and transmitted to all the cladding elements of a robot, so that they all appear at the same guard potential with respect to each other.

This connection interface may also be arranged to transmit a measurement or detection signal to another device, or device, such as for example a robot computer. According to an advantageous characteristic, the at least one measuring electrode can be separated from the at least one guard electrode by an elastically compressible layer locally, so that a pressure exerted on said dressing element locally modifies the distance between measurement and guard electrodes.

Such a compressible layer may be the core layer, or an additional layer in addition to the core layer.

Such a compressible layer makes it possible locally and elastically to vary the distance between at least one measuring electrode and the at least one guard electrode when a pressure, or a support, is exerted by an object on the 'dressing element.

The distance, and in particular the distance variation, between the measurement and guard electrodes makes it possible to characterize, in particular measure, the pressure exerted by the support, as a function of the compressibility of the compressible layer.

A signal that can be measured at the position of the support to characterize the pressure exerted may be a signal relating to or representative of the so-called inter-electrode resistance between the measurement and guard electrodes. In this case, it is necessary to polarize the measurement and guard electrodes with a potential difference. In addition, it is necessary that the compressible layer is electrically conductive, with a variable conductance as a function of pressure, for example by piezoresistive effect. Alternatively, or in addition, a signal that can be measured at the position of the support to characterize the pressure exerted, may be a signal relating to or representative of the capacitance, called inter-electrode, between the electrodes of measure and guard.

In this case, it is necessary to polarize the measurement and guard electrodes with an alternating potential difference at the measurement frequency. In addition, it is necessary that the compressible layer is dielectric.

The covering element according to the invention may comprise at least one electronic sensor for detecting a signal relating to the inter-electrode capacitance, or to the inter-electrode resistance between the measurement and guard electrodes at said support.

When the measured signal is relative to the inter-electrode capacitance, this detection electronics may be partially, totally, common to the electron-object capacitance detection electronics.

The covering element according to the invention can be in the form:

- a rigid or flexible shell;

a flexible covering intended to be fixed on a covering element of said robot.

The covering element according to the invention can be in the form:

an additional hull or coating intended to be mounted on an existing hull of a robot; or

- a replacement shell, designed to be mounted in place of an existing shell.

According to an advantageous embodiment, the cladding element may comprise two parts, intended to be positioned on either side of a segment or articulation of the robot, and coming to attach one with the other. other.

The two parts can be independent of each other before their positioning on the robot.

Alternatively, the two parts can be fixed to one another around a rotary axis, by means of a hinge, and movable relative to each other so that they can be:

- open to position the trim element around a segment, or articulation, of the robot, then

- be closed again.

In all cases, the cladding element is preferably fixedly mounted to the robot.

Fixing of the covering element can be achieved:

- By gluing, screwing or clipping on a surface of the robot; by at least one suction-type fixing means; and or

by at least one magnetic / magnetic fixing means.

Alternatively, or in addition, the cladding element may comprise at least one fastening means by clamping around a portion of the robot.

According to another aspect of the invention, there is provided a robot provided with at least one dressing element according to the invention.

In the robot according to the invention, the at least one dressing element according to the invention can be used as a replacement or in addition to an already existing dressing element.

The robot according to the invention may be a robot that initially has, or not, a capacitive detection feature.

Description of the Figures and Embodiments

Other advantages and characteristics will appear on examining the detailed description of non-limitative examples, and the appended drawings in which:

FIGURES 1, 2, 3a and 3b are diagrammatic representations, in section, of three exemplary embodiments of a cladding element according to the invention;

FIGURES 4a-4c are schematic representations of a robot equipped with two covering elements according to the invention;

FIGS. 5a and 5b are diagrammatic representations of two exemplary embodiments of a detection electronics that can be implemented with a covering element according to the invention; and

- FIGURES 6-7 are schematic representations, in section, of two other embodiments of a cladding element according to the invention.

It is understood that the embodiments which will be described in the following are in no way limiting. We can imagine variants of the invention comprising only a selection of characteristics subsequently described isolated from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention from the state of the art prior. This selection comprises at least one feature preferably functional without structural details, or with only a part of the structural details if this part alone is sufficient to confer a technical advantage or to differentiate the invention from the state of the prior art.

In particular, all the variants and all the embodiments described are combinable with each other if nothing stands in the way of this combination at the technical level.

In the figures, the elements common to several figures retain the same reference.

FIGURE 1 is a schematic representation, in section, of a first non-limiting exemplary embodiment of a cladding element according to the invention.

The covering element 100, shown in FIG. 1, is a rigid shell that can be used either in place of an existing shell on a robot, or in addition to an existing shell. In the latter case, the covering element 100 is positioned on the existing shell.

The covering element 100 can be used to equip a segment of a robot or a joint of a robot.

The covering element 100 comprises a plurality of capacitive electrodes

102, said measurement, and a capacitive electrode 104, said guard, common to all measuring electrodes. The guard electrode 104 forms a guard plane covering substantially all the measurement electrodes 102.

The covering element 100 further comprises a dielectric core layer 106 positioned between the measurement electrodes 102 and the guard electrode 104.

The central layer 106 may be made by a printed circuit, rigid or flexible, on which are deposited or etched, the measuring electrodes 102 and the guard electrode 104. Alternatively, the central layer 106 may be made of plastic by 3D printing, or by molding, or by thermoforming a substantially flat plastic plate.

The measurement electrodes 102 can then be deposited on the central layer 106 by:

projecting metal particles onto said central layer 106 after having positioned on said central layer a mask;

- inkjet type printing, or

- screen printing.

The guard electrode 104 can also be deposited on the central layer

106 by brushing said core layer 106 with a layer of conductive material.

The covering element 100 further comprises a layer 108, called the outer dielectric layer, positioned on the measurement electrodes 102. This outer layer 108 serves to protect the measurement electrodes from external aggression such as shocks, moisture or liquids. This outer layer 108 may be glued to the measuring electrodes 102 or may be made by depositing a coating on said measuring electrodes 102, such as for example a plastic coating, varnish, etc.

The outer layer 108 is preferably in contact with the measurement electrodes 102 so that there is no free space (or at least no significant air space) between said outer layer 108 and the electrodes of measure 102.

According to an exemplary embodiment, the outer layer 108 may be made in the form of a rigid, semi-rigid or flexible shell. The central layer 106 may be made (by molding, thermoforming or 3D printing) in the form of a rigid, semi-rigid or flexible shell of complementary shape to fit into the outer layer 108, and comprising on its faces the electrodes 102 and the guard electrode 104.

According to another exemplary embodiment, the outer layer 108 may be made in the form of a rigid, semi-rigid or flexible shell. The central layer 106 may be in the form of a double-sided printed circuit with the measurement electrodes 102 and the guard electrode 104. Optionally, the covering element 100 further comprises a layer 110, called the dielectric support layer, positioned under the guard electrode 104. This support layer 110 has the role of:

protect the guard electrode 104, and / or

isolating the guard electrode 104 from a conductive surface on which the covering element 100 is positioned, and / or

absorbing the surface discontinuities when the covering element 100 is positioned on a surface of a robot, and / or

- absorb shocks that may be exerted on the dressing element during its use.

The backing layer 110 may be made of a flexible material, such as flexible plastic or foam for example.

The backing layer 110 may be layers or coatings of insulation materials.

In the example shown in FIG. 1, the support layer 108 is formed by a discrete set of support elements 112 such as pins or support lugs.

The covering element 100 further comprises electronic modules 114, arranged between the support elements 112, under the level of the support elements, and in particular on the central layer 106, and on the same face as the guard electrode 104.

In the embodiment shown, the support elements 112 of the backing layer 108 also serve to mechanically protect the electronic modules 114. The electronic modules 114 are distant from each other. Each electronic module 114 comprises at least one detection electronics used for:

polarizing the measurement electrodes 102 with a first alternating electric potential different from a robot ground potential, at the working frequency, and

- Polarize the guard electrode 104 with an alternating electrical V _G , said guard, identical to the first potential, the working frequency. Each detection electronics comprises at least one electronic component configured to provide an output signal representative of the capacitance between a measurement electrode 102 and a surrounding object.

Examples of detection electronics are given in more detail below with reference to FIGURES 5a and 5b.

To protect each electronic module 114 of potential leakage capabilities, the covering element 100 comprises a cover 116, said guard, biased to the guard potential V _G and covering each electronic module 114 The polarization at the guard potential of each hood 116 can be achieved by electrically connecting each cover 116 to the guard electrode 104, itself biased to the guard potential V _G.

It should be noted that the hood 116 is not necessarily an external element. It can be realized by a guard wall, for example formed by a layer or a plane of the printed circuit of the electronic module 114.

FIG. 2 is a diagrammatic representation, in section, of another non-limiting exemplary embodiment of a cladding element according to the invention.

The cladding member 200 of FIGURE 2 includes all elements of the cladding member 100 of FIGURE 1.

Moreover, unlike the covering element 100 of FIG. 1, in the covering element 200 the electronic modules are positioned on the central layer 106 on the side of the measuring electrodes 102, in particular on the face of the central layer 106 comprising the measuring electrodes 102. In this configuration it is not necessary to use additional guard covers because the electronic modules 114 are kept at the guard potential by the guard electrode 104, polarized at the guard potential V _G and which is in fact a guard wall for the electronic modules.

FIGURE 6 is a schematic representation, in section, of another exemplary non-limiting embodiment of a cladding element according to the invention.

The covering element 600, of FIG. 6, comprises the measurement electrodes 102, the guard electrode (s) 104, the central layer 106, the outer layer 108, or the electronic modules (114). In the example shown in FIG. 6, the electronic modules 114 are made in the form of printed circuits that are distinct from the central layer 106 comprising the measurement electrodes 102 and the guard electrode 104. The electronic modules 114 are positioned at the level of FIG. of this central layer 106 in one or more openings made through this central layer 106, or on the edges of this central layer 106. The electronic modules 114 can thus be fixed on the outer layer 108. They are connected to the measuring electrodes 102 and the guard electrodes 104 for example by dowels made with the substrate of the core layer 106. Preferably, the electronic module or modules 114 comprises a guard wall 116 in the form of a printed circuit layer.

FIGURE 7 is a schematic representation, in section, of another exemplary non-limiting embodiment of a cladding element according to the invention.

The covering element 700, of FIG. 7, comprises the measurement electrodes 102, the guard electrode (s) 104, the central layer (106), the outer layer (108), or the electronic modules (114).

In the example shown in FIG. 7, the measurement electrodes 102 are made with a single-sided printed circuit 702.

The guard electrode (s) 104 are also made with a single-sided printed circuit 704.

The core layer 106 is made up of the substrate of at least one of the single-sided printed circuit boards 702 and 704, and as shown in the example illustrated in FIGURE 7, an intermediate member 706 disposed between said printed circuit boards.

The electronic module or modules 114 are made in the form of printed circuits distinct from the central layer 106. They are fixed on the outer layer 108. They are placed between the outer layer 108 and the single-sided printed circuit 704 with the guard electrodes. 104, and connected to the measuring electrodes 102 and to the guard electrode 104. Thus, the electronic module or modules 114 are protected by the guard electrodes 104. FIGURES 3a and 3b are diagrammatic representations, in section, of another non-limiting exemplary embodiment of a cladding element according to the invention.

The covering element 300, shown in FIGURES 3a and 3b, comprises all elements of the covering element 200 of FIGURE 2.

The covering element 300 furthermore comprises a layer 302 that is locally elastically compressible, placed between the central layer 106 and the measurement electrodes 102. This layer is for example made of very flexible plastic or foam. This compressible layer 302 makes it possible to vary, locally, the distance between the measurement electrodes 102 and the guard electrode 104, when a pressure is exerted on the covering element 300.

FIG. 3a represents the covering element 300 at rest and FIG. 3b represents the covering element 300 when a pressure, represented by the arrow 304, is applied to it.

Thus, by measuring the capacitance between the measuring electrodes 102 and the guard electrode 104 it is possible to characterize the pressure exerted. To do this, it is necessary to wear the measuring electrodes 102 and guard 104 at different alternative potentials, at the working frequency, at least at the position of the support. To do this, one of the measuring electrodes 102 and guard 104 can be grounded. Alternatively, or in addition, a non-zero alternating electric potential at the working frequency can be introduced between the guard electrode 104 and the measuring electrode 102. Alternatively to what has just been described in FIGURES 1, 2, 3a and

3b, the covering element may comprise an individual guard electrode for each measuring electrode, in place of a single guard electrode forming a guard plane.

In addition, the detection electronics may not be disposed in the cladding element but independently, for example on an electronic card independent of the cladding element.

FIGURE 4a is a schematic representation of a robot equipped with dressing elements according to the invention. The robot 400 is a robotic arm comprising a plurality of segments interconnected by rotary joints.

The robot 400 comprises three elements of covering 402, 403 and 404 according to the invention, each equipping a segment or articulation of the robot, either in place of an original cladding element of the robot, or in addition to an element original dress.

The covering element 403 is a hood that attaches to an articulation of the robot 400, replacing an existing hood. It is therefore fixed in the fixing interfaces (for example threads or screws) of the original cover.

FIGURE 4b is a schematic representation of the cladding element 402 equipping a segment of the robot 400.

The covering element 402 is in two parts 402i and 402 ₂ identical, section shaped half-cylinder. Each portion 402i and 402 ₂ is intended to be attached to the robot segment 400 by gluing.

Alternatively, each part may be fixed to the robot segment by screwing, clipping or suction-type means provided on the cladding element or the segment of the robot.

Visual cues 402 ₃ , provided on the outer faces of the parts 402i and 402 ₂ , allow to correctly position and orient each part

402i and 402 ₂ of the covering element 402 during its assembly on the robot segment.

The covering element 402 also comprises a mechanical positioning element 402 ₄ in the form of a lug or a raised element intended to fit into a groove or a recess machined on the robot 400.

FIGURE 4c is a schematic representation of the trim element 404 fitted to another segment of the robot 400.

The covering element 404 is in two parts 404i and 404 ₂ identical, section shaped half-cylinder. The parts 404i and 404 ₂ are assembled together by a hinge 404 ₃ allowing the rotation of said parts 404i and 404 ₂ so that said parts 404i and 404 ₂ can be opened to position the cladding element around of the segment of the robot 400, then closed again. The part 404i comprises one or more assembly means 404 ₄ , such as a collar or a clip, coming into (or abutting against) an assembly means 404 ₅ , such as an opening or a tongue or a lip 404 ₅ , provided on the portion 404 ₂ , to effect a clamping assembly of the trim member 404 around the robot segment.

Visual cues (not shown) provided on the outer faces of the trim element 404 allow to position and orient correctly during its assembly on the robot segment.

The cladding element 404 may also comprise a mechanical positioning element similar to the element 402 ₄ of the cladding element 402, in the form of a lug or a raised element intended to be inserted. in a groove or recess machined on the robot 400.

FIGURE 5a is a schematic representation of a first exemplary embodiment of a detection electronics that can be implemented in a cladding element according to the invention.

The sense electronics 500, shown in FIGURE 5a, may be, or may be, integrated into an electronic module 114 of FIGURES 1, 2, 3a and 3b. The detection electronics 500 can be made in analog or digital form, or an analog / digital combination

The detection electronics 500 receive an excitation voltage, denoted V _G , from an oscillator 502 referenced to a ground potential 504. The voltage V _G is used as a guard potential to polarize the electrode or electrodes guard 104, and as a first potential for biasing the measurement electrode or electrodes 102.

The detection electronics 500 comprises a current or charge amplifier, represented by an operational amplifier 506 and a feedback capacitor 508. In the embodiment presented, this charge amplifier outputs a voltage proportional to the voltage. coupling ability between an electrode 102 and an object nearby.

The detection electronics 500 further comprises a conditioner 510 for obtaining a signal representative of the desired coupling capacitance C _eo and / or the presence or proximity of an object of a body. This conditioner 510 may comprise, for example, a synchronous demodulator to demodulate the signal with respect to a carrier, at a working frequency. Conditioner 510 may also include an asynchronous demodulator or an amplitude detector. This conditioner 510 can, of course, be made in an analog and / or digital form (microprocessor) and include all necessary means of filtering, conversion, treatment, etc.

The detection electronics 500 may be dedicated to a measurement electrode 102 so that each measurement electrode has its own detection electronics.

Alternatively, and as shown in FIG. 5b, the detection electronics 500 may be common to several measurement electrodes 102.

In this case, the detection electronics 500 further comprises a scanning means 512 connecting the charge amplifier 506, in turn, to each measuring electrode 102, so as to individually interrogate each of said measurement electrodes 102.

Of course, the measurement electronics 500 may comprise other components than those described.

The detection electronics 500, or at least its sensitive portion with the charge amplifier 506 can be referenced (or powered by referenced power supplies) to the guard potential V _G , to minimize parasitic capacitances.

The detection electronics 500 can also be referenced, more conventionally, to the ground potential 504.

Of course, the invention is not limited to the examples which have just been described and many adjustments can be made to these examples without departing from the scope of the invention.

Claims

1. Cladding element (100; 200; 300; 402; 403; 404; 600; 700) for a robot (400), in particular adapted to be positioned on a segment or articulation of a robot (400) at the in place or in addition to a covering element of said robot (400), said dressing element

(100; 200; 300; 402; 403; 404; 600; 700) comprising:

at least one capacitive electrode (102), said measuring electrode, intended to be biased to a first alternating electric potential different from a ground potential (504), at a working frequency,

at least one guard electrode (104) disposed under said at least one measuring electrode (102) and designed to be biased to an alternating (V _G ) electrical potential, said to be identical, or substantially identical to said first potential at said working frequency, and

at least one so-called central dielectric layer (106) disposed between said at least one measuring electrode (102) and said at least one guard electrode (104).

2. Cladding element (100; 200; 300; 402; 403; 404; 600; 700) according to the preceding claim, characterized in that it comprises at least one layer (108), said external dielectric, disposed on the measurement electrode or electrodes (102).

3. Cladding element (100; 200; 300; 402; 403; 404; 600; 700) according to the preceding claim, characterized in that it comprises a rigid, semi-rigid or flexible external layer (108), and a central layer (106) in the form of a separate element shaped to fit into the outer layer (108), and comprising on its faces, respectively, said at least one measuring electrode (102) and said at least one guard electrode (104).

4. Cladding element (100; 200; 300; 402; 403; 404) according to any one of the preceding claims, characterized in that it comprises a layer (110), called support layer, arranged under the the guard electrodes (104), and intended to come into contact with a surface of the robot (400).

5. Cladding element (100; 200; 300; 402; 403; 404; 600; 700) according to any one of the preceding claims, characterized in that it comprises a positioning means or a marker (402 ₃ 402 ₄ ), for mounting said cladding element (100; 200; 300) in a determined or determinable position and orientation on a part of the robot (400).

6. cladding element (100; 200; 300; 402; 403; 404) according to any one of the preceding claims, characterized in that the central layer (106) is in the form of a double-sided printed circuit the measuring electrode or electrodes (102) being disposed on one side of said printed circuit, and the one or more guard electrodes (104) being disposed on the opposite side of said printed circuit.

7. Cladding element (100; 200; 300; 402; 403; 404) according to any one of the preceding claims, characterized in that it comprises at least one detection electronics (114) configured to measure a relative signal a coupling capacitance, referred to as the electrode-object capacitance, between at least one measuring electrode (102) and a surrounding object.

8. Cladding element (100; 200; 300; 402; 403; 404; 600; 700) according to claim 7, characterized in that it comprises several groups of detection electronics (114) distributed on said cladding member (100; 200; 300; 402; 404; 600; 700) spaced from each other.

9. Cladding element (100; 402; 403; 404; 700) according to claim 2 and any one of claims 7 or 8, characterized in that at least one detection electronics (114) is placed between the outer layer (108) and a guard electrode (104).

10. Cladding element (100; 200; 402; 403; 404) according to any one of claims 7 to 9, characterized in that at least one detection electronics (114) is arranged on the central layer (106). ).

11. Cladding element (100; 402; 403; 404) according to any one of claims 7 to 10, characterized in that at least one electronics of detection (114) is kept at the guard potential (V _G ) by a wall or guard cover (116) polarized at the guard potential (V _G ).

12. Cladding element (100; 200; 300; 402; 403; 404; 600; 700) according to any one of the preceding claims, characterized in that it comprises at least one wired and / or wireless connection interface. wire arranged for:

- receive at least one alternating electric potential corresponding to the first alternating potential or the guard potential (V _G ), or both; and or

- transmit a measurement or detection signal.

13. Cladding element (300; 402; 403; 404) according to any one of the preceding claims, characterized in that the at least one measuring electrode (102) is separated from the at least one guard electrode (104) by a resiliently locally compressible layer (302) such that pressing on said trim member (300) locally changes the distance between the measuring (102) and guard (104) electrodes.

14. Cladding element (300; 402; 403; 404) according to the preceding claim, characterized in that it comprises at least one detection electronics of a signal relating to the capacitance and / or resistance, called inter -electrodes, between the measuring electrodes (102) and guard (104), at said support.

15. Cladding element (100; 200; 300; 402; 403; 404; 600; 700) according to any one of the preceding claims, characterized in that it is in the form of:

- a rigid or flexible shell;

a flexible coating intended to be fixed on a covering element of said robot (400).

16. Cladding element (100; 200; 300; 402; 403; 404; 600; 700) according to any one of the preceding claims, characterized in that it is in the form of: an additional hull or coating intended to be mounted on an existing hull of a robot; or

- a replacement shell, designed to be mounted in place of an existing shell.

17. Cladding element (100; 200; 300; 402; 403; 404; 600; 700) according to any one of the preceding claims, characterized in that it comprises two parts (402i, 402 ₂ ; 404i, 404 ₂ ), intended to be positioned on either side of a segment or articulation of the robot, and being fixed with each other.

18. Robot (400) provided with at least one dressing element (402, 403; 404) according to any one of the preceding claims.