Robot equipped with capacitive detection

Abstract

A robot includes a body on which is mounted a functional head also including a capacitive detector, including: at least one electrical insulator in order to electrically insulate the functional head; at least one apparatus for electrically polarizing the functional head at a first alternating electrical potential (V.sub.g), different from a ground potential; at least one guard polarized at an alternating guard potential (V.sub.G) identical to the first alternating electrical potential; and at least one electronics, called detection electronics, for measuring a signal relating to a coupling capacitance, called electrode-object capacitance, between the sensitive part and a surrounding object.

Claims

1. A robot including a body and a functional head removably mounted on the body, where the functional head forms a tool, or a tool-holder, the robot also comprising capacitive detection means comprising: a sensitive part configured as the functional head, wherein the functional head acts as a capacitive detection electrode that detects an object or person in a detection zone around the functional head; at least one electrical insulator to electrically insulate the sensitive part of said functional head from the rest of the robot; at least one means for electrically polarizing said sensitive part by a first alternating electrical potential (V.sub.g), different from a ground potential; a guard that is polarized at a second alternating potential (V.sub.G), where the second alternating potential (V.sub.G) is identical or substantially identical to the first alternating electrical potential (V.sub.G) at a given working frequency, to electrically guard said sensitive part; and detection electronics configured for measuring a signal relating to a coupling capacitance between said sensitive part and a surrounding object.

2. The robot according to claim 1, further comprising a mechanical interface, articulated or not, between the functional head and the body, with an electrical insulator, and the guard arranged between the functional head and the body at the level of said interface.

3. The robot according to claim 1, wherein the functional head comprises at least one electrical component part, and further comprising a guard volume or guard walls, arranged around said at least one electrical component part, and polarized at the guard potential (V.sub.G) at the working frequency.

4. The robot according to claim 1, wherein the functional head comprises at least one electrical component part, and further comprising at least one electrical converter arranged for: receiving at least one electrical signal, called input electrical signal, such as a power supply or control signal, intended for said electrical component part, and referencing said input signal to the guard potential (V.sub.G); and/or receiving at least one electrical signal, called output electrical signal, transmitted by said electrical component part, and referencing said output signal to the electrical ground potential of a controller for which it is intended.

5. The robot according to claim 4, wherein the converter comprises: at least one power supply with galvanic isolation such as a DC/DC converter, in particular to generate an input power supply signal for said at least one electrical component part; at least one electrical interface without galvanic contact, of the capacitive type or by optocoupler, for at least one control input signal, or at least one output signal; and/or one or more inductors having high impedance to receive and transmit at least one input signal or at least one output signal.

6. The robot according to claim 1, further comprising a guard produced by a layer of conductive material.

7. The robot according to claim 1, further comprising a guard produced by a metal part of the robot, arranged between the body and the sensitive part of the functional head, electrically insulated on both sides, and polarized at the guard potential (V.sub.G).

8. The robot according to claim 1, wherein the guard partially covers the sensitive part of the functional head.

9. The robot according to claim 1, wherein the guard produced by at least a part, or the totality, of the body of the robot, is polarized at the guard potential (V.sub.G).

10. The robot according to claim 1, wherein the guard is formed by a mounted part in a form of a sleeve extending along the robot over a non-zero distance and in a direction away from, or opposite to, the sensitive part of the functional head.

11. The robot according to claim 1, further comprising at least one additional capacitive sensor arranged other than on the sensitive part of the functional head, the detection electronics being, at least partially, in common with a detection electronics of said at least one additional capacitive sensor.

12. The robot according to claim 11, wherein the at least one additional capacitive sensor is polarized at an alternating potential identical to the first potential, at the working frequency.

13. The robot according to claim 1, wherein the functional head comprises at least one of: a means for gripping an object; a means for processing an object; and a means for inspecting an object.

14. The robot according to claim 1, wherein the robot has the form of a robotized arm.

15. A device having the form of a tool, or a tool-holder, intended to form a functional head of a robot according to claim 1, and comprising the capacitive detection means of the robot.

16. A connection interface for a robot according to claim 1, intended to be arranged between the functional head and the body of the robot, said connection interface comprising the capacitive detection means of the robot.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other advantages and characteristics will become apparent on examination of the detailed description of non-limitative examples and from the attached drawings in which:

(2) FIG. 1 is a diagrammatic representation of an example of a robot according to the prior art;

(3) FIG. 2 is a diagrammatic representation of a non-limitative example of a robot according to the invention;

(4) FIGS. 3-6 are partial diagrammatic representations of different embodiment examples of a robot according to the invention; and

(5) FIGS. 7 and 8 are diagrammatic representations of two non-limitative embodiment examples of a connection interface according to the invention.

DETAILED DESCRIPTION

(6) It is well understood that the embodiments that will be described hereinafter are in no way limitative. In particular, variants of the invention may be envisaged comprising only a selection of characteristics described hereinafter, in isolation from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention with respect to the state of the prior art. This selection comprises at least one, preferably functional, characteristic 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 with respect to the state of the prior art.

(7) In particular, all the variants and all the embodiments described may be combined together if there is no objection to such combination from a technical point of view.

(8) In the figures, elements that are common to several figures retain the same reference.

(9) FIG. 1 is a diagrammatic representation of an embodiment example of a robot according to the prior art.

(10) The robot 100, shown in FIG. 1, has the form of an articulated robotized arm.

(11) The robotized arm 100 can be for example an industrial collaborative robot working under the supervision of, or in collaboration with, an operator 102, or also a medical robot in the case of a surgical operation on the body of a person 102, or also a personal assistance robot 102.

(12) The robotized arm 110 comprises a body 104 constituted by one or more articulated parts, and a functional head 106, mounted at the end of a robotized arm 104, by virtue of a mechanical interface 108, articulated or not. The functional head 106 is mounted on the body 104 in a detachable or removable manner in order to be interchangeable with other functional heads that are identical or different, fulfilling one and the same function or different functions.

(13) In the example shown, the functional head 106 is a gripper for gripping, handling and moving objects from a point A to a point B. In FIG. 1, the robotized arm is shown with an object 110 held by the gripper 106.

(14) FIG. 2 is a diagrammatic representation of a non-limitative embodiment of a robot according to the invention.

(15) The robot 200 shown in FIG. 2, is a robotized arm such as that in FIG. 1. The robotized arm 200 comprises all the elements of the robotized arm 100 in FIG. 1.

(16) In the robotized arm 200, the functional head 106 is used as a capacitive detection electrode in order to detect objects or the person 102 present in a detection zone 202 all around the functional head 106.

(17) To this end, an interface 204 is arranged between the functional head 106 and the body 104 of the robotized arm 200. This interface 204 comprises: on the one hand an electrical insulator making it possible to electrically insulate the functional head 106 from the rest of the robotized arm 200; and on the other hand an electrical guard, insulated both from the functional head 106 and the body 104 of the robot 200, and polarized at an alternating electrical potential, called guard potential, different from a ground potential of the robotized arm 200, and in particular from the body 104 of the robotized arm, at a given working frequency.
A first non-limitative embodiment example of the interface 204 is given in FIGS. 3 and 4, and a second non-limitative example of the interface is given in FIG. 5.

(18) In addition, an electronic module 206 is provided in order to: polarize the functional head 106 at an alternating electrical potential identical or substantially identical to the guard potential at the working frequency; and measure an electrical signal, and in particular an electrical current, relating to a coupling capacitance, called electrode-object capacitance, and denoted C.sub.eo, between the functional head 106 and its environment.
Non-limitative embodiment examples of such a module 206 are given in FIGS. 3 to 6.

(19) FIG. 3 is a partial diagrammatic representation of another non-limitative embodiment example of a robot according to the invention.

(20) The robotized arm 300, partially shown in FIG. 3, can be the robotized arm 200 in FIG. 2, and comprises all of the elements of the robotized arm 200.

(21) In FIG. 3, only the end of the robotized arm 300 comprising the functional head 106 is shown.

(22) In the example shown in FIG. 3, the electronic module 206 comprises an oscillator 302 which generates an alternating excitation voltage, denoted V.sub.G, used to polarize the functional head 106 acting as detection electrode, and also used as guard potential.

(23) The electronic module 206 also comprises a detection electronics 304 composed of a current or charge amplifier, represented by an operational amplifier 306 and a feedback capacitance 308.

(24) The detection electronics 304 also comprises a signal conditioner 310 making it possible to obtain a signal representative of the sought coupling capacitance C.sub.eo, and/or of the presence or the proximity of an object of a body. This signal conditioner 310 can comprise for example a synchronous demodulator for demodulating the signal with respect to a carrier wave, at a working frequency. The signal conditioner 310 can also comprise an asynchronous demodulator or an amplitude detector. This signal conditioner 310 can of course be produced in an analogue and/or digital form (microprocessor), and comprise all necessary means for filtering, conversion, processing etc.

(25) In the configuration shown in FIG. 3, the functional head 106 is polarized via the operational amplifier 306. In particular, the oscillator 302 is connected to the positive input of the operational amplifier 306 and the functional head is connected to the negative input of the operational amplifier 306.

(26) In the robotized arm, the interface 204 is arranged between the functional head 106 polarized at the guard potential V.sub.G, and the body 104 polarized at the general ground potential. In the example shown in FIG. 3, the interface comprises a guard plane 312, for example formed by a metal part, polarized at the guard potential V.sub.G by the voltage provided by the oscillator 302.

(27) The guard plane 312 is electrically insulated from the functional head 106 by a first electrical insulator element 314, and from the body 104 of the robotized arm 300 by a second electrical insulator 316.

(28) Thus, the guard plane 312 makes it possible to electrically guard the functional head and to increase its detection sensitivity. In addition, the guard plane 312 makes it possible to avoid an inadvertent detection of the body 104 of the robotized arm by the functional head.

(29) In the majority of cases, the functional head 106 can be equipped with one or more electrical component parts such as one or more sensors, or one or more motors or actuators.

(30) In the example shown in FIG. 3, the functional head 106 is equipped with an electric motor 318. This electric motor 318 is supplied and controlled by a controller 320 of the robotized arm, dedicated or not to said motor 318 and referenced to the ground potential of the robotized arm, or of an electronics of the robotized arm, different from the guard potential V.sub.G.

(31) Without precautionary measures, such an electric motor 318 could trigger an inadvertent detection of the part of the functional head 106 used as capacitive electrode, due to the presence of a ground potential.

(32) In order to avoid this, the electronic module 206 comprises a converter 322 arranged between the controller 320 and the motor 318 and having the function of: receiving at least one electrical signal, called input electrical signal, such as a power supply or control signal, transmitted by the controller 320 and intended for the motor 318, and referencing said input signal to the guard potential V.sub.G; and receiving at least one electrical signal, called output electrical signal, transmitted by said motor 318, and intended for the controller 320, and referencing said output signal to the electrical ground potential of the controller.

(33) Thus the motor 318, as well as the connectors and the electronics which are associated therewith are supplied by signals referenced to the guard potential V.sub.G and do not interfere with the capacitive detection electrode constituted by the functional head 106.

(34) FIG. 4 is a partial diagrammatic representation of another non-limitative embodiment example of a robot according to the invention.

(35) The robotized arm 400 partially shown in FIG. 4 can be the robotized arm 200 in FIG. 2. In FIG. 4, only the end of the robotized arm 400 comprising the functional head 106 is visible.

(36) The robotized arm 400 shown in FIG. 4 comprises all of the elements of the robotized arm 300 in FIG. 3, except the potential converter 322. In fact, in the robotized arm 400, the motor 318 is connected to the controller 320 without using a potential converter.

(37) Unlike the robotized arm 300, in the robotized arm 400, in order to avoid the functional head 106, when used as a capacitive detection electrode, detecting the motor 318 as well at its electronics and its electric wires, the latter are arranged in a housing 402, called guard housing, polarized at the guard potential. Thus the motor 318 as well as its electronics and its electric wires are not detected by the functional head 106.

(38) FIG. 5 is a partial diagrammatic representation of another non-limitative embodiment example of a robot according to the invention.

(39) The robotized arm 500 partially shown in FIG. 4 can be the robotized arm 200 in FIG. 2. In FIG. 5, only the end of the robotized arm 500 comprising the functional head 106 is shown.

(40) The robotized robot arm 500 shown in FIG. 5 comprises all the elements of the robotized arm 300 in FIG. 3.

(41) Unlike the robotized arm 300, the robotized arm 500 comprises a guard 502 having the form of a sleeve arranged on the body 104 and extending over the body 104 opposite the functional head 106. Thus, the functional head 106 is electrically better guarded with respect to the body 104 of the robotized arm 500.

(42) The robotized arm 500 comprises a second electrical insulator 504 between the guard 502 and the body 104, also in the form of a sleeve arranged between the guard 104 and the body 104 and extending over the body 104 opposite the functional head 106.

(43) Regardless of the embodiment example, the robotized arm can comprise additional capacitive electrodes, in addition to the functional head 106 used as a capacitive detection electrode. The robot 500 in FIG. 5 comprises for example such capacitive electrodes, referenced 506 and arranged on the guard 502 with an intercalated insulating layer.

(44) Preferentially, these additional capacitive electrodes can be managed by the same electronics as that used for the capacitive head 106 and/or use the same alternating potential, at the working frequency. Alternatively, these additional capacitive electrodes can be managed by a separate electrode, and/or use a different alternating potential.

(45) These additional capacitive electrodes can have the form of a capacitive skin arranged on the body 104 of the robotized arm in a removable or detachable manner, or integrated in the outer layer of the body 104 of the robotized arm.

(46) FIG. 6 is a partial diagrammatic representation of another non-limitative embodiment example of a robot according to the invention.

(47) The robotized arm 600 partially shown in FIG. 6 can be the robotized arm 200 in FIG. 2. In FIG. 6, only the end of the robotized arm 600 comprising the functional head 106 is shown.

(48) The robotized arm 600 shown in FIG. 5 comprises all the elements of the robotized arm 300 in FIG. 3, except the guard element 312 and the second insulating element 316.

(49) In fact, unlike the robotized arm 300, in the robotized arm 600, the guard is produced by a part or the totality of the body 104 of the robotized arm. This part, or the totality, of the body 104 producing the guard is polarized at the guard potential V.sub.G.

(50) In this case, and in order to avoid any interference between the body 104 (or the part of the body 104) polarized at the guard potential V.sub.G and the electronics of the robotized arm 600 referenced to the general ground potential, a potential converter is used, such as for example the potential converter 322. This potential converter 322 has the purpose of referencing the signals going to electrical component parts arranged in the body 104 at the guard potential, and the signals originating from these electrical component parts and going to the controller 320, to the general ground potential.

(51) As before, the robotized arm can comprise additional capacitive electrodes, arranged on the body 104. These additional capacitive electrodes can have the form of a capacitive skin arranged on the body 104 of the robotized arm in a removable or detachable manner, or integrated in the outer layer of the body 104 of the robotized arm. In this embodiment, it is not necessary to intercalate a guard between the body 104 of the robot and these additional capacitive electrodes.

(52) The connection interface 204 can form an integral part of the functional head 106 or of the body of the robot 104. It can also be produced in the form of a separate element.

(53) FIG. 7 is a diagrammatic representation of a non-limitative example of a connection interface according to the invention in the form of a part separate from the functional head 106 or from the body of the robot 104.

(54) The connection interface 700, shown in FIG. 7, can be the connection interface 204 of the robot 200 in FIG. 2.

(55) The connection interface 700 is shown in FIG. 7 in a configuration disconnected from the functional head 106 and from the body 104.

(56) The connection interface 700 is arranged between the functional head 106 and the body 104. It can be an additional interface which does not exist on the original robot, or replace an existing interface on the original robot. The connection interface 700 comprises capacitive detection means, namely the electronic module 206, the guard 312 as well as the insulating elements 314 and 316.

(57) In the embodiment shown, the interface 700 includes: on the side of the functional head 106, a mechanical interface or mechanical connectors 702 and an electrical connector 704, identical to those present on the body 104, in order to provide a mechanical and electrical connection with the functional head 106; and on the side of the body 104, a mechanical interface or mechanical connectors 706 and an electrical connector 708, identical to those present on the functional head 106, in order to provide a mechanical and electrical connection with the body of the tool.
In addition, the interfaces or mechanical connectors 702 are complementary with the interfaces or the mechanical connectors 706 and the electrical connector 704 is complementary with the electrical connector 708.

(58) Moreover, the connection interface 700 comprises, on the side of the functional head 106, an electrical contact 710 in order to polarize the functional head at an alternating electrical potential identical or substantially identical to the guard potential, at the working frequency.

(59) Of course, a similar connection interface can be used in the case where a part or the totality of the body 104 of the robot is used as a guard, such as for example in the robot 600 in FIG. 6.

(60) FIG. 8 is a diagrammatic representation of a non-limitative embodiment example of such a connection interface, in a disconnected configuration.

(61) The connection interface 800, shown in FIG. 8, comprises all the elements of the connection interface 700 in FIG. 7, except the insulating element 316.

(62) In addition, the connection interface 800 comprises, on the side of the body 104 an electrical contact 802, in order to polarize the body 104 at the guard potential.

(63) Of course, the electronic module 206 can comprise components other than those described.

(64) In addition, the electronic module 206 can be at least partially integrated in an electronics of the robot, or in the body of the robot, or in the functional head, or also in an existing or additional interface, positioned between the functional head and the body of the robot.

(65) The electronic module 206 can also have the form of a module or a casing external to the body of the robot, and/or, in the embodiments in FIGS. 7 and 8, external to the connection interface 700 or 800. In this case, all or part of the electrical connections described can be located at the level of the electronic modules 206 connected to the other elements by cables.

(66) Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without exceeding the scope of the invention.