WO2017042134A1

WO2017042134A1 - Hinge, haptic device, motion capture device and robot comprising such a hinge

Info

Publication number: WO2017042134A1
Application number: PCT/EP2016/070887
Authority: WO
Inventors: Florian Gosselin; Dominique Ponsort; Pascal Chambaud
Original assignee: Commissariat A L´Energie Atomique Et Aux Energies Alternatives
Priority date: 2015-09-08
Filing date: 2016-09-05
Publication date: 2017-03-16
Also published as: FR3040783B1; FR3040783A1

Abstract

The invention relates to a hinge comprising an angular sensor (100) that includes measuring means comprising: at least two emitters (111, 112) of light rays and at least one receiver (121) of said light rays, the emitters being arranged so that the axes of the emitters extend obliquely relative to one another; and/or at least one emitter of light rays and at least two receivers of said light rays, the receivers being arranged so that the axes of the receivers extend obliquely relative to one another. The invention also relates to a haptic device comprising such a hinge, to a motion capture device comprising such a hinge and to a robot comprising such a hinge.

Description

Articulation, haptic device, motion capture device and robot comprising such

joint

The invention relates to a joint provided with an angular sensor, a haptic device comprising such a joint such as a glove, a motion capture device comprising such a joint and a robot comprising such a joint.

TECHNOLOGICAL BACKGROUND OF THE INVENTION Robots, haptic devices and electromechanical motion capture devices are devices comprising a plurality of movable elements interconnected by mechanical links which are usually of pivot or slide type. The robots and haptic devices are provided with motors allowing the movable elements to be moved or, on the contrary, to resist an effort applied by the environment or the user. Electromechanical motion capture devices are generally passive on the contrary, that is to say, not equipped with motors, their displacements being solely due to the movements of the user.

In all cases, all these devices include position sensors to know the configuration of the various moving elements. In general, on robots and haptic devices, these sensors are arranged at the motors. They allow to better control the movements and efforts that robots and haptic devices apply. These sensors can also be arranged at the joints connecting the different movable elements to each other, which are most often pivot links more easy to make and motorize as slide links. On electromechanical motion capture devices, which are not motorized, the sensors are generally arranged at the joints.

In the case of a pivot type joint, on most robots, haptic devices and electromechanical motion capture devices, the angular position sensors used are potentiometers, magnetic Hall effect sensors, type sensors. capacitive or optical encoders.

However, these components are most of the time expensive and relatively bulky when it is desired to obtain a good measurement resolution. In addition, their electronic conditioning and processing are relatively complex.

These disadvantages are particularly disadvantageous when one seeks to design haptic devices such as gloves, when one seeks to design electromechanical capture devices movements of the hand or the hands of the user or when the we seek to design robots such as robotic hands that have a large number of mobilities and must still remain compact, lightweight and a reasonable cost.

To overcome these drawbacks, an angular sensor consisting of an LED and a photodiode has been developed and described in the article 'Optoelectronic joint angular sensor for robotic fingers', Sensors and Actuators A: Physical, vol. 152, 2009, pp. 203-210 of A. Cavallo, G. De Maria, C. Natale, S. Pirozzi. This sensor is such that the LED is attached to one segment of the robot and the photodiode is attached to another segment of the robot pivotally mounted relative to the segment on which the LED is fixed,

The illumination profile of the LED is not isotropic, the light it emits is not the same in all direct ions. It is maximum in the axis of the LED and decreases as one moves away from this axis. It also decreases when you move away from the LED. Similarly, the sensitivity to illumination of the photodiode is not isotropic and the voltage associated with the received light depends on the direction in which it is illuminated. The voltage is maximum when the illuminating beam is in the axis of the photodiode and decreases as the beam is inclined relative to this axis.

Thus, by positioning the LED and the photodiode so that the angle between the segment which connects them and the axis of the LED and / or the angle between the segment which connects them and the axis of the photodiode and / or the distance that separates them varies according to the rotation of the joint, the quantity of light generated by the LED and received by the photodiode varies according to the angle of articulation connecting the two segments, which makes it possible to measure this angle.

However, this sensor has the disadvantage that the output voltage of said sensor does not vary linearly as a function of the angle of articulation over the entire measuring range of the sensor.

As a result, the sensitivity of the sensor is not constant over the entire measurement range of the sensor since for certain angular values, a small displacement around the axis of the articulation results in a large variation of the output voltage of the sensor while for other angular values, a displacement of the same amplitude is only reflected by a low variation of this voltage. For these second values, it is therefore difficult to discriminate the angular variation around the axis of the joint.

03JET OF THE INVENTION

An object of the invention is to propose a hinge comprising an angular sensor having a linear or quasi-linear response and a sensitivity varying little over a wider range of measurement.

The invention also relates to a haptic device comprising such a joint, a motion capture device comprising such a joint and a robot comprising such a joint.

BRIEF DESCRIPTION OF THE INVENTION

With a view to achieving this object, an articulation is proposed comprising a first element and a second element pivotable relative to each other about an axis and at least one angular sensor which comprises measuring means comprising:

at least two light ray emitters and at least one receiver of said light rays, the emitters being arranged in such a way that the axes of the emitters extend obliquely with respect to each other, and / or

at least one light-emitting transmitter and at least two receivers of said light rays, the receivers being arranged so that the axes of the receivers extend obliquely with respect to each other,

the angular sensor being arranged such that at least a portion of the at least one emitter is attached to the first member and so that at least a portion of the at least one receiver is attached to the second member

In the first case, the receiver is illuminated by at least two emitters which are angularly offset with respect to each other and in the second case, the emitter illuminates at least two receivers which are angularly offset relative to one another. to the other. Thus, in both cases, the response of the serial measurement means of elementary functions provided by each of the transmitter / receiver pairs in place is broken down. It is then possible to june on each of these functions and on their combination to linearize the response of the measuring means over a wider range of measurement range. In the first case, it is thus possible to play both on the luminous intensities of the transmitters and on the relative positions of the transmitters, in particular on their angular offset, compared to the receiver, and in the second case, it is thus possible to play both on the light sensitivities of the receivers and on the relative positions of the receivers, in particular on their angular offset, compared to the transmitter.

In this way, the response of the measuring means is linear or quasi-linear over a large measuring range, which guarantees a sensor sensitivity that varies little.

In. in addition, this also facilitates the processing of the measurements made by the sensor. For the purposes of this application, the term "receiver axis" refers to the axis in which the sensitivity to illumination of the receiver is maximized. Similarly, the term "issuer axis" refers to the axis in which the majority of radii are emitted by the transmitter.

According to a particular embodiment, the emitters are identical or the receivers are identical.

According to a particular embodiment, at least one transmitter comprises a source of emission directly illuminating at least one associated receiver.

According to a particular embodiment, at least one transmitter comprises a main transmission part and a guiding secondary part, at least one receiver being indirectly illuminated by the main transmission part via the guiding secondary part.

According to a particular embodiment, the guide portion comprises at least one optical fiber.

According to a particular embodiment, the guide secondary portion is fixed to the first element as the main transmission part.

According to a particular embodiment, the sensor comprises at least one optical system for modulating a light intensity and / or a convergence of the rays emitted by at least one emitter.

According to a particular embodiment, the optical system comprises a diaphragm.

According to a particular embodiment, the sensor comprises at least one cover arranged around one or more transmitters and / or one or more receivers. According to a particular embodiment, the sensor comprises at least one support through which a part of the transmitter or emitters is fixed to the first element and / or comprises at least one support, through which part of the receiver or receivers. is attached to the second element.

According to a particular embodiment, at least one of the supports comprises a chute adapted to receive the part of the transmitter or the receiver associated with the support.

According to a particular embodiment, at least one of the receivers is arranged so that a light-sensitive area of said receiver is on the axis of the hinge.

According to a particular embodiment, at least one of the emitters is arranged so that its axis is concurrent with the axis of the joint.

According to a particular embodiment, at least one of the emitters is arranged so that its axis belongs to the plane which is normal to the axis of the articulation and which comprises the axis of at least one of the receivers.

According to a particular embodiment, the sensor comprises at least one transmitter and two receivers, the transmitter being arranged so that its axis belongs to a first plane which is normal to the axis of the articulation and which is different from a second plane and a third plane normal to the axis of articulation and each respectively comprising the axis of one of the receivers, the receivers being arranged so that the second plane and the third plane are different the one another and are located at identical distances from the foreground. According to a particular embodiment, the sensor comprises at least one transmitter and two receivers, the receivers being arranged in the same plane which has normal axis 1 of the articulation.

The invention also relates to a robot comprising at least one joint as previously described.

The invention also relates to a haptic device comprising at least one articulation as previously described.

According to a particular embodiment, the haptic device comprises a glove.

The invention also relates to a motion capture device comprising at least one articulation as previously described.

The motion capture device is an electromechanical motion capture device (as opposed to optical motion capture devices such as the Ki nect (trademark) device).

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood in the light of the following description of non-limiting embodiments of the invention with reference to the attached figures, among which:

Figure 1 is a perspective view of a hinge comprising an angular sensor according to a first embodiment of the invention;

Figure 2 is a perspective view of a hinge comprising an angular sensor according to a second embodiment of the invention; Figure 3 is a perspective view of a hinge comprising an angular sensor according to a third embodiment of the invention;

Figure 4 is a perspective view of an articulatio ion comprising an angular sensor according to a fourth embodiment of the invention;

Figure 5 is a perspective view of a hinge comprising an angular sensor according to a fifth embodiment of the invention;

Figure 6 is a perspective view of a hinge comprising an angular sensor according to a sixth embodiment of the invention;

Figure 7 is a perspective view of a hinge comprising an angular sensor according to a seventh embodiment of the invention;

- Figure 8 is a perspective view of a robot comprising a plurality of joints according to the first embodiment of the invention;

- Figure 9 is a perspective view of a first hapt.i device that comprises several joints according to the first embodiment of the invention;

Figure 10 is a perspective view of a second haptic device comprising a plurality of joints according to the first embodiment of the invention;

FIG. 11 is a perspective view of a motion capture device comprising a plurality of joints according to the first embodiment of the invention,

The different figures are simplified for example in terms of the representation of cables and circuits printed matter, in particular those used for powering the transmitters and for processing data of the receivers that are not represented, so as not to unduly burden said figures.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, the articulation according to the first embodiment of the invention comprises a sensor 100. The articulation also comprises a first element 101 and a second element 102, the first element 101 being mounted rotatably on the second element 102 about an axis A.

The cape 100 comprises measurement means which here comprise two transmitters 111, 112 and a receiver 121.

The sensor 100 here comprises a first support 131 on which the emitters 111, 112 are fixed, the first support 131 being itself fixed on the first element 101. In this way the emitters 111, 112 are fixed to the first element 101 and secured in rotation to the first element 101. The two emitters 111, 112 are arranged so as to be offset angularly with respect to each other, that is to say that their axes extend obliquely relative to each other. the other.

The sensor 100 also comprises a second support 132 on which the receiver 121 is fixed, the second support 132 being itself fixed on the second element 102. In this way the receiver 121 is fixed to the second element 102 and secured in rotation to the second element 102.

Preferably, the first support 131 is shaped so as to have two recessed shapes 133, 134 adapted to each receive one of the emitters 111, 112. The hollow form is for example a semi-cylindrical chute of the same diameter as the transmitter which is arranged there. Shoulders are further provided at the end of the chute to precisely position the associated emitter in the chute in the longitudinal direction of the chute.

In the same way, the second support 132 is shaped so as to have a hollow shape 135 adapted to receive the receiver 121. The hollow shape is for example a semi-cylindrical chute of the same diameter as the receiver 121. Shoulders are further provided at the chute end to accurately position the receiver 121 in the chute in the longitudinal direction of the chute.

The emitters 111, 112 are here identical. Each transmitter 111, 112 comprises a diode. Each transmitter 111, 112 further comprises here a protective plastic packaging within which the diode is arranged.

Preferably, each transmitter 111, 112 is configured to emit light rays outside the visible light spectrum. The diode of each transmitter 111, 112 is thus an infrared radiation diode.

The emitters 111, 112 being angularly offset relative to each other, their axes 115, 116 therefore extend obliquely relative to each other.

The emitters 111, 112 are connected to supply means (not shown here) which comprise for example a current source or a voltage source. The emitters 111, 112 can be powered in parallel as well as in series. The receiver 121 here comprises a phototransistor. The receiver 121 further comprises here a protective plastic packaging inside which the phototransistor is arranged. The package is configured to filter a part of the light spectrum by passing light rays belonging to a restricted range of the light spectrum centered around the wavelength of the rays emitted by the emitters 111, 112. In this case , the packaging of the receiver 121 is thus configured so as to let pass only the infrared rays,

The receiver 121 is connected to a calculation unit (not shown here), whether or not part of the sensor 100, which makes it possible to measure the voltage across the receiver representative of the light received by the phototransistor and to deduce an estimate therefrom. of the relative angle between the first element 101 and the second element 102. Indeed, the voltage across the receiver 121 can be considered as the sum of the voltages generated by the illumination of the receiver 121 by each of the emitters, each of dependent voltages itself:

the angle at which the phototransistor is illuminated (corresponding, for each transmitter, to the angle between on the one hand the axis of the receiver and on the other hand the line connecting the emitter diode and the phototransistor of the receiver ),

the intensity with which the phototransistor is illuminated, this intensity depending itself on the one hand the angle at which the diode emits light towards the phototransistor (corresponding, for each transmitter, the angle between d ' a part 1 / axis of the transmitter and other the line connecting the transmitter diode and the receiver phototransistor), and the distance between each transmitter 111, 112 and the receiver 121.

Preferably, the receiver 121 is configured to operate over a wide angular range, the response of the receiver 121 varying depending on the angle at which the phototransistor is illuminated over this wide angular range. Said wide angular range is for example from 10 degrees to 60 degrees. Preferably, the receiver 121 is arranged so that the phototransistor, and in particular its light-sensitive area, is on the axis Ά. Also preferably, the emitters 111, 112 are arranged such that their axes 115, 116 are concurrent with the axis A and pass through the sensitive area of the phototransistor 121 of the receiver regardless of the relative position between the first element 101 and the second element 102.

Preferably, the emitters 111, 112 are arranged so that their axes are in the same plane having normal axis A. Also preferably, the receiver 115 is arranged so that its axis belongs to this plane .

Thus, the distance between the emitters 111, 112 and the receiver 121 as well as the angle at which the diodes of the emitters 111, 112 emit light towards the phototransistor of the receiver 121 do not vary when the first element 101 revolves around the axis A relative to the second element 102: only the angle at which the phototransistor is illuminated then changes the voltage across the phototransistor, which simplifies modeling the sensor 100 and make easier its optimization to obtain a more linear response of the measuring means and therefore the sensor.

Noting E (Θ) the total illumination of the receiver 121 for an angle Θ according to which the phototransistor is illuminated, Am and A ₁₁₂ the luminous intensity of each transmitter 111, 112 assumed constant and Em (Θ) and Eu ₂ (Θ ) the measured illuminances of the emitters 111, 112 by the receiver 121, we have:

E (Θ) = m. Em (θ) + Α ₁₁₂ · Ειπ (Θ)

The emitters 111, 112 being here identical, and being assumed to be supplied here identically, we obtain, noting cn ₂ the angular offset between them about the axis A {the angle between the two axes of the emitters 115, 116):

E (θ) = Α _ηι .Ε _ιη (θ) + us.Einie + fs)

By appropriately choosing the intensities Ain and An ₂ and the angular offset cu ₂ , it is possible to obtain a linear or quasi-linear response of the measuring means over a wide measurement range.

For example, an angular offset φ ₁₁₂ is chosen between the two emitters 111, 112 of 20 degrees.

A first embodiment of the joint according to the invention has thus been described.

As a variant, the one or more supports 131, 132 and the troughs 133, 134, 135 may have different shapes and / or dimensions. The support (s) may thus be shaped to cover the transmitter (s) and / or the receiver, for example having a portion of tubular section, with or without shoulders, so as to protect the transmitter or emitters 111, 112 and / or the receiver 121. The channel or troughs 133, 134, 135 may still have a larger diameter than the emitters 111, 112 and / or the receiver 121, so as to leave enough room for adhesive or calluses, rigid or not, arranged in the channel or chutes and used to immobilize the transmitter or emitters 111, 112 and / or the receiver 121 relative to the associated support. More generally, the one or more supports may comprise one or more receiving portions of one or more transmitters and the receiver which will be of larger dimensions than the transmitter, the emitters and / or the associated receiver so as to leave enough space for glue or calluses, rigid or not, arranged in said portion or portions and used to immobilize the transmitter or emitters 111, 112, and / or the receiver 121, relative to the associated support.

Although here emitters 111, 112 are identical they could also be different.

Although here the angular offset between the two emitters 111, 112 is 20 degrees, this angle may be different. It can thus be lower or higher, depending on the response of each of the transmitter / receiver pairs,

As a variant, the emitters 111, 112 will be arranged so that their axes lie in planes different from each other, with the axis A being normal,

As a variant, the receiver 121 will be arranged so that its axis lies in a plane normal to the axis A and different from the plane normal to the axis A in which the axis of the transmitter 111 and / or different is located. the plane normal to the axis A in which the axis of the transmitter is located 112. In this case, it will be possible to weight the contribution of the two transmitters 111, 112 in order to have a better linearization of the response of the measuring means by varying the distance between the plane normal to the axis A in which is located the axis of the receiver 121 and the plane normal to the axis A in which the axis of the transmitter 111 is located and / or by varying the distance between the plane normal to the axis A in which is the axis of the receiver 121 and the plane normal to the axis A in which is the axis of the transmitter 112.

Alternatively also, the emitters 111, 112 will be arranged so that their axes will be inclined with respect to the plane including the axis of the receiver 121 and having normal axis A, the axes of the emitters 111, 112 then describing a portion of cone axis A during the relative movements between the first element 101 and the second element 102. In this case, it will be possible to weight the contribution of the two emitters 111, 112 in order to have a better linearization of the response of the means measurement by choosing a different inclination of each of the axes of the emitters 111, 112 relative to the plane comprising the axis of the receiver 121 and having normal axis A.

With reference to FIG. 2, the sensor 200 of the articulation according to the second embodiment of the invention is identical to the sensor 100 of the articulation according to the first embodiment of the invention, with the difference that the means The measuring devices comprise three transmitters 211, 212, 213 instead of two. The emitters 211, 212, 213 are here arranged so that the emitter 212 is shifted by an angle φ ₂ ι ₂ by 20 degrees about the axis A with respect to the emitter 211 and so that the emitter 213 is offset by an angle φ ₂ ΐ3 of 40 degrees around the axis A relative to the emitter 211.

This makes it possible to further increase the measurement range of the sensor 200 in which the response of the measurement means is linear.

A second embodiment of the joint according to the invention has thus been described.

The angular offset angles between the emitters 211, 212, 213 have been given by way of example and other angular offset angle values between the emitters 211 and 212, respectively 211 and 213, may well be used. for other joints.

With reference to FIG. 3, the sensor 300 of the articulation according to the third embodiment of the invention is identical to the sensor 100 of the articulation of the first embodiment of the invention, with the difference that the axes of the emitters 311, 312 are no longer concurrent with the axis A. This results in an offset of the emitters 311, 312 on the first element 301 relative to the axis A compared to the first embodiment.

The receiver 321 is here also shifted relative to the axis A so that the phototransistor, and in particular its light-sensitive area, is no longer on the axis A.

Therefore, in addition to the angle at which the phototransistor 321 is illuminated by the emitters 311, 312, the distance between the emitters 311, 312 and the receiver 321 and the angle at which the emitter diodes 311, 312 emit of light to the phototransistor of the receiver 321 vary during a relative movement between the first element 301 and the second element 302, which adds additional parameters influencing the output of the measuring means.

With reference to FIG. 4, the sensor 400 of the articulation according to the fourth embodiment of the invention is identical to the sensor 100 of the articulation of the first embodiment of the invention, with the difference that the means of measurement comprise a single transmitter 411 instead of two and two receivers 421, 422 instead of one. The two receivers 421, 422 are then arranged so that their axes are inclined with respect to each other.

In particular, the receivers 421, 422 are arranged in such a way that their axes are in the same plane which has the axis A as normal. Preferably, the receivers 421, 422 are arranged so that the axis of the transmitter 415 belongs to the plane in which the axes of the receivers 421, 422 are located.

The receivers 421, 422 are furthermore arranged in such a way that their axes lie in this plane on either side of said axis A. The receivers 421, 422 are thus arranged so that their phototransistors, and in particular their sensitive areas, to light rays, are not on axis A but on either side of the said axis A.

In this case, since the axis of the transmitter 415 no longer passes through the sensitive area of the phototransistors, the luminous intensity of the transmitter 411 received by each of the receivers will also vary according to the angle between on the one hand the axis of the transmitter 415 and on the other hand the axes connecting the diode of the transmitter to each of the phototransistors of the receivers, which adds additional parameters influencing the output of the measuring means.

As a variant, one of the two receivers is arranged so that its phototransistor, and in particular its light-sensitive zone, is on the axis A, the other of the receivers being always offset relative to said axis A. In this case, In this case, the distance between the transmitter 411 and this first receiver as well as the angle at which the diode of the transmitter 411 emits light towards the phototransistor of this first receiver do not vary during the relative movements between the first element. 401 and the second element 402, which simplifies the study of the output of the measuring means,

With reference to FIG. 5, the sensor 500 of the articulation according to the fifth embodiment of the invention is identical to the sensor 400 of the articulation of the fourth embodiment of the invention, with the difference that the two receivers 521, 522 are arranged so that their axes lie in different planes parallel to each other, each of these planes having normal axis A.

The two receivers 521, 522 are furthermore arranged so that their phototransistors, and in particular their light-sensitive areas, are both on the axis A. In this case, the distance between the emitter 511 and the receivers 521, 522 and the angles at which the emitter diode 511 emits light to the phototransistors of the receivers 521, 522 do not vary during the relative motions between the first element 501 and the second element 502, which simplifies the study of the output of the measuring means.

The receivers 521, 522 are here arranged so that the axis of the transmitter 515 does not belong to any of the planes having for normal axis A in which the axes of the receivers 52.1, 522 are located. In particular, the receivers 521, 522 are arranged so that the planes having for normal axis A in which the axes of the receivers 521, 522 extend lie at the same distance from the plane comprising the axis of the transmitter 515 and having normal axis A.

In this way, the two receivers 521, 522 have the same contribution to the output of the measuring means.

Alternatively, the receivers 521, 522 are arranged such that the planes having normal axis A in which the axes of the receivers 521, 522 extend are located at different distances from the plane comprising the axis of the transmitter. 515 and having normal axis A,

In this case, it is possible to weight the contribution of the two receivers 521, 522 in order to have a better linearization of the response of the measuring means.

Alternatively also, the receivers 521, 522 are arranged so that their axes are inclined relative to the plane comprising the axis of the transmitter 515 and having normal axis A, the axes of the receivers 521, 522 describing a portion cone of axis A during the relative movements between the first element 501 and the second element 502.

In this case, it is possible to weight the contribution of the two receivers 521, 522 in order to have a better linearization of the response of the measuring means by choosing a different inclination of each of the axes of the receivers 521, 522 with respect to the plane comprising the axis of the emitter 515 and having normal axis A.

With reference to FIG. 6, the sensor 600 of the articulation according to the sixth embodiment of the invention is identical to the. 100 sensor of the articulation of the first embodiment of the invention with the difference that the first support 631 has a transverse portion 636 extending facing emitters 611, 612, the transverse portion 636 having two diaphragms 637 arranged each in front of one of the emitters 611, 612 at the axes of the emitters 615, 616.

These diaphragms 637 make it possible to better manage the directivity of the beam of the diodes of the emitters 611, 612.

The diaphragms 637 are here identical so that the light rays coming from the first emitter 611 and the second emitter 612 perceived by the receiver 621 have the same luminous intensity when the emitters 611, 612 are fed in the same way.

The diaphragms 637 are here shaped in simple holes drilled in the transverse portion 636.

With reference to FIG. 7, the sensor 700 of the articulation according to the seventh embodiment of the invention will be described. This sensor 700 is similar to that of the articulation of the first embodiment, with the difference that each transmitter 711, respectively 712 comprises a main transmission part 717, 718 respectively which comprises the diode and the associated protective packaging and a guide abutment detailed below, the receiver 721 then no longer illuminated directly by the diodes of the emitters 711, 712 but by the guide parts of the emitters 711, 712.

The sensor 700 here comprises a first support 731 on which the first main part 717 is fixed, the first support 731 itself being fixed on the first element 701. The sensor 700 further comprises a second support 738 on which the second main part 718 is fixed, the second support 738 itself being fixed on the first element 701.

In this way the main parts of emission 717,

718 emitters 711, 712 are attached to the first element 701 and rotatably connected to the first element 701.

The sensor 700 also comprises a third support 732 on which the receiver 721 is fixed, the third support 732 itself being fixed on the second element 702. In this way the receiver 721 is fixed to the second element 702 and secured in rotation to the second element 702.

The guiding abutments will now be detailed. The guiding abutments here comprise a first optical fiber 751 associated with the first transmitting main part 717 and a second optical fiber 752 associated with the second transmitting main part 718. The sensor 700 comprises supports 739 in which are guided the optical fibers 751, 752, said supports 739 being themselves fixed on the first element 701. In this way, the optical fibers 751, 752 are fixed to the first element 701 and rotatably connected to the first element 701.

The optical fibers 751, 752 are arranged so that a first end of the first optical fiber 751 or opposite the first main portion of emission 717 and so that a first end of the second optical fiber 752 is opposite the second main transmission part 718. Preferably, the optical fibers 751, 752 are arranged so that the first end of each optical fiber 751, 752 extends along an axis which coincides with the axis of the diode of the associated main transmission part (ie the axis in which the majority of the rays are emitted by the diode).

The supports 739 are furthermore arranged so that the second end of the first optical fiber 751 is facing the receiver 721 and so that the second end of the second optical fiber 752 is facing the receiver 721, the two second ends extending obliquely relative to each other ie such that the axes of the emitters 715, 716 extend obliquely with respect to each other.

Preferably, the receiver 721 is arranged so that the phototransistor, and in particular its light-sensitive area, is on the axis A. Also preferably, the optical fibers 751, 752 are arranged so that the axes transmitters 715, 716 are concurrent with the axis A and pass through the sensitive area of the phototransistor of the receiver 721 regardless of the relative position between the first element 701 and the second element 702.

Thus, the light emitted by the emitters 711, 712 is transmitted via the optical fibers 751, 752 to the receiver 721. The receiver 721 is thus no longer illuminated directly by the diodes of the emitters 711, 712 but indirectly via the optical fibers 751. 752. Of course, although here the sensor 700 comprises two transmitters 711, 712 and a single receiver 721 and although here it is the transmitters 711, 712 which comprise a main transmission part and a secondary guide part, this sensor could also include the single transmitter and two receivers, the receivers having a main measurement portion connected to the body 702 and a guide secondary portion.

Referring to Figure 8, a robot 1000 comprising a plurality of joints according to the first embodiment of the invention will now be described.

The robot 1000 is here a serial robot with six degrees of freedom. The robot 1000 typically includes a base 1010, a clamp 1030 and a mechanical structure 1020 hinged to the base 1010 and to move the clamp 1030 relative to the base 1010 in any position and in any orientation in the limit of the working space of the robot 1000. The base 1010 can be here fixed or mobile.

The mechanical structure 1020 is a series structure comprising:

a movable element 1051 articulated on the fixed base

1010,

a bast 1052 and a link 1053 both articulated on the movable element 1051,

a forearm 1055 whose first end is articulated on the arm 1052,

a first wrist element 1056 articulated on the second end of the forearm 1055,

a second wrist element 1057 articulated on the first wrist element 1056, and a third wrist element 1058 articulated on the second wrist element 1057 and on which the clamp 1030 is fixed, directly or via a force sensor.

The mechanical structure 1020 further comprises a rod 1054 hinged to the rod 1053 and the forearm 1055, the connecting rod 1054 for transmitting the movements of the link 1053 to the forearm 1055, the arm 1052, the rod 1053, the connecting rod 1054 and the forearm 1055 thus form a parallelogram structure.

The element 1051, the arm 1052, the rod 1053, and the elements 1056, 1057 and 1058 are here moved by motors 1040 of the robot 1000 which can also oppose their movements preferably through a gearbox. The motors 1040 here comprise position sensors visible on the rear of the motors (i.e. on the engine side opposite to the output shaft of the engine considered).

The robot 1000 further comprises angular sensors 100 identical to those of the hinge according to the first embodiment of the invention. In particular, the robot 1000 comprises a first angular sensor 100 arranged at the articulation between the movable element 1051 and the base 1010, a second angular sensor 100 arranged at the joint between the arm 1052 and the mobile element 1051 and a third angular sensor 100 arranged at the joint between the rod 1053 and the movable member 1051. These angular sensors 100 here allow to measure the movements of the element 1051 relative to the base 1010, the arm 1052 relative to the element 1051 and the link 1053 relative to the element 1051. The angular sensors 100 advantageously provide absolute measurements of the movement of the mobile element 1051, the arm 1052 and the rod 1053. These measurements can be redundant with those of the position sensors of the motors 1040 associated with the mobile element 1051, the arm 1052 and link 1053 if these position sensors are also absolute. This redundancy then makes it possible to improve the reliability of the measurements and the safety of the robot 1000.

These measurements can also be complementary to those of the position sensors of the motors 1040 associated with the mobile element 1051, the arm 1052 and the link 1053 if these position sensors are incremental (that is to say that the sensors deliver a pulse signal at each elementary displacement of the motor concerned, the measurements of such sensors being dependent on the number of rotations already made by the sensor). This avoids having to initialize the measurements of the position of the robot 1000 at startup, for example by putting all the constituent members of the mechanical structure 1020 in abutment, as is the case when a robot has only incremental position sensors. .

Referring to Figure 9, a haptic device 2000 comprising a plurality of joints according to the first embodiment of the invention will now be described.

The haptic device 2000 comprises a base 2010, a mechanical structure of the delta type 2020 connected to said base 2010 and a platform comprising a handle 2030, the platform being linked to the mechanical structure 2020 so as to be displaceable in translation by said structure mechanical 2020 following any direction of space compared to base 2010.

The 2010 base includes three 2040 engines that rotate the mobile elements closest to the 2010 base of each branch of the delta 2020 mechanical structure, for example via gearboxes. These 2040 motors preferably have position sensors visible at the rear of the motors.

The haptic device 2000 comprises angular sensors 100 of the articulation according to the first embodiment of the invention which are integrated here at the joints of these elements at the base 2010. These angular sensors 100 make it possible to measure the angular movements of said element compared to the 2010 base, in a redundant or complementary way with the position sensors of the 2040 engines.

With reference to FIG. 10, a haptic device 3000 comprising several articulations according to the first embodiment of the invention will now be described, the supports of the transmitters and receivers surrounding here the transmitters and the associated receivers, said supports comprising Portions having a tubular section running around the emitters and receivers,

The haptic device 3000 is here a manual exoskeleton in the form of a glove.

The haptic device 3000 comprises a base 3010 intended to be fixed on the hand of the user by means not shown, for example straps. The haptic device 3000 further comprises four mechanical structures 3020 which are each articulated on the base 3010. The haptic device 3000 further comprises four end devices 3030 each hinged respectively to one of the structures 3020 and intended to receive the phalangette of the thumb, index, middle finger and ring finger, respectively. 'user.

The haptic device 3000 further comprises actuators 3040 (only part of which is visible here) configured to generate a force feedback on the fingertips of the user via the mechanical structures 3020 and integrated actuators (not visible here). end devices 3030 configured to generate local haptic feedback on the fingertips of the user. These actuators 3040 preferably comprise position sensors, only part of which is visible at the rear of the motors.

Such a haptic device 3000 is for example described in the French application of the present applicant with filing number 58301 and may be referred to this request for further information.

The haptic device 3000 comprises angular sensors 100 (only a part of which is visible here) of the articulation according to the first embodiment of the invention arranged on different articulations of the haptic device. Preferably, the angular sensors 100 are arranged on the joints connecting the mechanical structures 3020 to the base 3010 and some internal joints to the mechanical structures 3020.

Some of these angular sensors 100 are arranged on the joints actuated by the actuators 3040 and whose movements are already measured by the sensors associated with these motors. Angular sensors 100 then make it possible to know precisely the absolute angular position of the elements forming these actuated joints, in addition to the position sensors of the actuators 3040.

Other angular sensors 100, in particular the angular sensors 100 measuring the movements of the joints connecting the base 3010 to the mechanical structures 3020, are the only sensors measuring the movements of these joints. These angular sensors 100 are advantageously simple, compact, lightweight and inexpensive.

Referring to Figure 11, a motion capture device 4000 in the form of glove comprenar. The more angular sensors 100 of the joint according to the first embodiment of the invention will now be described. This motion capture device 4000 is identical to the haptic device 3000 described previously with the difference that the motion capture device 4000 does not include actuators on the mechanical structures 4020 and on the end devices 4030.

The 4020 mechanical structures are not motorized, they follow the movements of the fingers of the hand of the user without constraining them.

The angular sensors 100 integrated on the motion capture device 4000 make it possible to measure these movements.

Advantageously, the angular sensors 100 are inexpensive and can independently measure the movements of each joint provided with such sensors. In addition, the motion capture device 4000 is less susceptible to visual occlusions than prior art optical motion capture devices using one or more cameras to measure hand movements.

Naturally, the invention is not limited to the embodiments described and variations can be made without departing from the scope of the invention as defined by the claims.

In particular, although here the transmitters all include an infrared light emitting diode, the emitters may include other emission sources such as a light emitting diode emitting in another frequency band than the infrared, a photodiode, a vertical cavity surface-emitting laser diode (VCSEL), a laser source or a light source emitting in the visible or invisible light field. The transmitters may be more or less directive (it being understood that a highly directive emitter transmits all or almost all of the spokes along its axis).

Similarly, although here the receivers all include a phototransistor operating in the infrared, the receivers may comprise other reception means such as a phototransistor operating in another frequency band, a photodiode, a PIN diode (for the English "Positive Intrinsic Negative Diode") or a photoresistor. The sensor will consequently comprise accordingly suitable supply means and possibly one or more adapted calculation units, the measured quantity being able to be for example a voltage or a current. Receivers may be more or less effective.

In addition, it will be possible to use a different number of transmitter and a different number of receiver than those illustrated, in particular to linearize the response of the measuring means over a wider measurement range, provided that there are at least two transmitters and one receiver or at least one transmitter and two receivers. For example, there may be two transmitters and two receivers. The response of the measurement means in series of elementary functions provided by each of the transmitter / receiver pairs of the sensor will thus be broken down in the same way as the functions in Fourier series are decomposed.

In addition, although here all transmitters are identical on the same sensor and all receivers are identical on the same sensor, the same sensor may include different transmitters and / or different receivers in particular to improve the linearity of the sensor and increase its useful measuring range.

When the measuring means comprise at least two transmitters, the power supply of these transmitters can be done in series as well as in parallel. The emitters may equally well be connected to the same power supply means as to remote power supply means, these power supply means being identical or different. It will thus be possible to feed each of the emitters with a different current or a different voltage in order to modify their relative contribution to the response of the measuring means, in particular in order to optimally linearize said response. In the same way, when the measuring means comprise at least two receivers, the receivers may just as easily be connected to the same calculation units as to separate calculation units, these calculation units possibly being identical or different. Whether they are connected to the same calculation units or to separate calculation units, the amplification gains, the filters, and more generally the means for processing the signals of each of the receivers may be identical or different.

Moreover, whether or not the emitters comprise a guide part, the emitters and / or the receivers may be arranged differently with respect to each other and also with respect to the axis of the articulation associated with the sensor. which has been illustrated. Whether or not the emitters comprise a guiding part, it will also be possible to shift more or less each emitter and / or receiver relative to the axis. Whether the transmitter or transmitters comprise or not a guide portion, it will also more or less incline each transmitter and / or each receiver relative to the axis.

In the case where the transmitter comprises a guiding part, it will be possible to arrange the main transmission part elsewhere than on the first element, for example on the second element or on any other part of the robot or the haptic device or the capture device. associated movement or on any other body independent of the articulation of the first element and the second element such as a fixed base, the guide portion ensuring that the rays emitted by the main transmission part are transmitted to the receiver. When the transmitter comprises guiding parts, they may include any other transmission means that optical fibers such as mirrors. The transmission means may further comprise lenses or other optical focusing devices, for example between the main transmission parts and the guide parts or between the guide parts and the receiver or receivers.

Although here the diaphragms of the sensor have an identical diameter, they may have a different diameter. We can still use one or more diaphragms with adjustable opening in place of single hole. Any other optical system other than the diaphragms may also be used to modulate the light intensity and the convergence of the rays emitted by the emitter to the receiver, such as lenses or slots or grooves.

More generally, it is possible to use different emitters and / or to use different currents or supply voltages on the different emitters and / or to incline more or less each of the emitters with respect to a plane of normal the axis of the emitter. articulating and / or placing one, a part or all of the emitters behind one or more diaphragm-type optical systems and / or placing each of the emitters in planes more or less distant from the elements of the articulation along the axis articulating and / or using different receptors and / or inclining more or less each of the receptors relative to a plane of normal the axis of the joint and / or placing each of the receptors in planes more or less distant from the elements of the joint along the axis of the joint and / or use gains amplifier, filters and different signal processing means on each of the receivers.

Furthermore, although here the transmitters and receivers are fixed on independent supports of the elements of the joint and attached to the joints, the supports may be an integral part of the elements of the joint being for example machined directly in said elements . Alternatively, the transmitters and. the receivers can be directly attached to said elements, for example by gluing. The supports can come to cover the emitters and receivers to better protect them.

The support or supports may have shapes and / or dimensions different from those illustrated. The support (s) may thus be shaped to cover the transmitter (s) and / or the receiver (s), for example having a portion of cylindrical section, with or without shoulders, so as to protect the transmitter (s) and / or the or the receivers.

The one or more supports may comprise one or more receiving portions of one or more transmitters and / or of one or more receivers which will be of larger size than the transmitter (s) and / or the associated receiver (s) so as to leave sufficient space for adhesive or cal les, rigid or not, arranged in said portion and used to immobilize the transmitter or transmitters and / or the receiver or receivers, relative to the associated support.

If at least one support comprises a chute, it may thus still have a larger diameter than the transmitter (s) and / or associated receiver (s), so as to leave sufficient room for glue or calles, rigid or not, arranged in the chute to immobilize the transmitter or transmitters and / or the associated receiver or receivers, relative to the associated support.

In addition, the angular sensor may comprise one or more hoods arranged around one or more transmitters and / or one or more receivers to limit light pollution between transmitters and receivers.

The term "element" generally refers to any body that can be part of a joint. The terms "arm", "forearm", "link", "connecting rod" ... fit well into the more general term "element".

Of course, the robots, haptics and motion capture devices described are not limiting and we can use joints according to the present invention on any other type of robot, for example and non-exhaustively a a serial robot, a parallel robot, a series / parallel architecture or tree structure robot, a robotic hand, with redundant or non-redundant actuation, having between one and six degrees of freedom or more ... or on any other another type of haptic device, for example and in a non-exhaustive manner on a device with series, parallel, mixed or arborescent architecture, with redundant or non-redundant actuation, an exoskeleton of the leg, arm or hand ... or on any other type of motion capture device, for example and in a non-exhaustive manner on a device with series, parallel, mixed or arborescent architecture, with actuation redundant or not, an exoskeleton of leg, arm or hand .... Of course also, although here the different robots, haptics and motion capture devices comprise angular sensors according to the first embodiment, the various robots, haptics and motion capture devices may include one or more joints according to the first embodiment. any variant or description of the present invention. It will also be possible to use different types of joints according to the invention on the same robot, the same haptic device or the same device for capturing motion. It is also possible to combine existing sensors with angular articulation sensors according to the present invention on the same robot, the same haptic device or the same motion capture device.

The various robots, haptic devices and motion capture devices may include the angular sensors on other axes than those described and / or may comprise a different number of angular sensors than that described.

In the case of haptic devices and motion capture devices described in the form of gloves, said gloves may include a different number of mechanical structures and / or end devices to follow the movements of more or fewer fingers of the user.

Moreover, the actuators, the motors, the position sensors associated with these motors and the gearboxes associated with these motors may be of any suitable type. The motors can thus advantageously be DC electric motors with rotor without iron or brushless motors but also and without limitation conventional DC motors. The actuators may comprise motors of any type or else shape memory alloys, electroactive polymers, piezoelectric actuators, pneumatic or hydraulic actuators. It will generally be possible to use other actuators than the motors represented on the illustrated robots and haptic devices. It will also be possible on haptic devices to use on one or more axes brakes instead of engines, these brakes may be including, but not limited to, disc brakes, powder brakes or magneto or electro-rheological fluid brakes. In this case the device can only oppose the movements of the user and not act on him actively. It will still be possible to use hybrid actuators combining a motor and a brake of all types presented above. On the robots and haptic devices, it will also be possible to use on one or more axes actuators with counter-actuation and / or variable stiffness of the elastic actuators type in series (in English "series elastic actuators") or elastic actuators in parallel (in English). "Parallel elastic actuators"). The reducers may be cable or non-exhaustive capstans of single or epicyclic single-stage or multi-stage gearboxes, gearbox type gearboxes (of the "Harmonie Drive" gearbox type) or ball screw reducers or any combination of these or other reduction elements. In the case of the use of capstans, it will also be advantageous machining a helical profile on the pulleys and providing guidance systems and tension cables. It is still possible on some axes to have non-reversible reducers such as worm gear reducers. In the case of the use of motors and / or gearboxes with low efficiency and / or having high or little or no reversible friction, it may preferably be used at the level of the motors, at the joints of the robot / haptic device or at its base or at its end, force sensors whose signals will be used to compensate for these defects and make the robot / haptic device reversible. The position sensors may be of any type suitable, in particular and in a non-exhaustive manner, optical encoders, Hall effect sensors, potentiometers or magneto-optical encoders. These position sensors can be absolute (multi-turns) or relative. On robots and haptic devices, they can be integrated on the engines. All or part of them may also be placed on certain articulations of the robot / haptic device / motion capture device, in addition to or in place of the hinge sensors according to the present invention. On robots and haptic devices, we can still have on one or more axes position sensors on both engines and joints.

The kinematic connections can be provided by simple bearings, ball bearings, plain bearings, magnetic bearings ... Moreover some links have been illustrated in a simplified way cantilever. It may be advantageous to make connections in screed, that is to say with a recovery efforts on each side of the link. This is particularly true for the rotational guidance of the pulleys whose efforts may advantageously be taken up by bearings or bearings on the side of the pulleys opposite the motors.

Claims

1. Articulation comprising a first member (101; 201; 301; 401; 501; 601; 701) and a second member (102; 202; 302; 402; 502; 602; 702) pivotable relative to one another; another about an axis (A) and at least one angular sensor {100; 200; 300; 400; 500; 600; 700), the angle sensor (100; 200; 300; 400; 500; 600; 700) having measuring means comprising:

at least two emitters (111, 112, 211, 212, 213, 311, 312, 611, 612, 711, 712) of light rays and at least one receiver (121; 221; 321; 621; 721) of said light rays, the emitters being arranged in such a way that that the axes of the emitters extend obliquely with respect to each other, and / or

at least one emitter (411; 511) of light rays and at least two receivers (421, 422, 521, 522) of said light rays, the receivers being arranged in such a way that the axes of the receivers extend obliquely with respect to each other,

the angular sensor being arranged such that at least a portion of the at least one emitter is attached to the first member and so that at least a portion of the at least one receiver is attached to the second member.

2. Articulation according to claim 1, wherein the emitters (111,112; 211,212,213; 311,312; 611,612;

711, 712) are identical or in which the receivers (421, 422, 521, 522) are identical.

3. Articulation according to one of the preceding claims, wherein at least one transmitter (111,112; 211,212,213; 311,312; 411; 511; 611,612) comprises a source of emission directly illuminating at least one receiver (121; 221; 321; 421,422; 521,522; 621) associated.

4. Articulation according to one of claims 1 to 2, wherein at least one transmitter {711, 712} comprises a main transmission part (717, 718) and a guide secondary part, at least one receiver (721). being indirectly illuminated by the main transmission part via the guiding abutment.

5. Articulation according to claim 4, wherein the guide portion comprises at least one optical fiber

(751, 752),

6. Articulation according to one of claims 4 or 5, wherein the guide secondary portion is attached to the first element (701) as the main transmission part.

7. Articulation according to one of the preceding claims, wherein the sensor (600) comprises at least one optical system for modulating a light intensity and / or convergence of rays emitted by at least one transmitter (611, 612).

8. Articulation according to claim 7, wherein the optical system comprises a diaphragm (637).

9. Articulation according to one of claims 1 to 8, wherein the sensor comprises at least one cover arranged around one or more transmitters and / or one or more receivers.

10. Articulation according to one of claims 1 to 9, wherein the sensor {100; 200; 300; 400; 500; 600; 700) comprises at least one carrier (131; 231; 331; 431; 531; 631; 731,738) through which a part of the emitter (s) is attached to the first element and / or comprises at least one support {132; 232; 332; 432; 532, · 632; 732) through which part of the receiver (s) is attached to the second element,

The joint of claim 10, wherein at least one of the supports (131, 132; 231,232;

331,332; 431,432; 531, 532; 631,632; 731, 732, 738) comprises a chute adapted to receive a part of the transmitter or the receiver associated with the support.

12. Articulation according to one of claims 1 to 11, wherein at least one of the receivers (121; 221;

521.522; 621; 721) is arranged so that a light sensitive area of said receiver is on the axis (A).

13. Articulation according to one of claims 1 to 12, wherein at least one of the emitters (111,112;

211,212,213; 411; 511; 611,612; 711,712) is arranged so that its axis is concurrent with the axis (A).

14. Articulation according to one of claims 1 to 13, wherein at least one of the emitters (111, 112; 211,212,213; 311, 312; 411; 611,612; 711,712) is arranged so that its axis belongs to the normal plane. to the axis of the joint and which includes the axis of at least one of the receptors.

15. Articulation according to one of claims 1 to 13, the sensor (500) comprising at least one transmitter (511) and two receivers (521, 522), the transmitter being arranged so that its axis is in a foreground which is normal to the axis of the joint and which is different from a normal second plane and third plane at 1 / axis of the joint and each respectively comprising the axis of one of the receivers, the receivers being arranged so that the second plane and the third plane are different from each other and are located at identical distances from the foreground.

16. Articulation according to one of claims 1 to 14, the sensor (400) comprising at least one transmitter (411) and two receivers (421, 422), the receivers being arranged in the same plane which has the normal axis (AT) .

17. Robot comprising at least one joint according to one of claims 1 to 16.

18. A haptic device comprising at least one articulation according to one of claims 1 to 16.

19. haptic device according to the preceding claim, wherein the haptic device comprises a glove.

Motion capture device comprising at least one articulation according to one of claims 10 to 16.