WO2009153429A1

WO2009153429A1 - Manipulating arm having a detachable end incorporating motors

Info

Publication number: WO2009153429A1
Application number: PCT/FR2009/000580
Authority: WO
Inventors: Philippe Garrec
Original assignee: Commissariat A L'energie Atomique
Priority date: 2008-05-19
Filing date: 2009-05-19
Publication date: 2009-12-23
Also published as: FR2931092B1; FR2931092A1

Abstract

The invention relates to a manipulating arm comprising one or more segments, with an end segment (1) having an end for holding a tool (8), the manipulating arm having multiple degrees of freedom, one or more of said degrees of freedom being controlled by an electric motor or motors (30, 31, 32) arranged on the manipulating arm, the electric motor(s) being placed on a detachable end portion (4) of the end segment, the invention being characterized in that the end segment and the detachable end portion are provided with a rapid connection/disconnection means (105) operable by remote-controlled means.

Description

MANIPULATOR ARM HAVING REMOVABLE END INCORPORATING MOTORS

The invention relates to a manipulator arm, for example a slave arm which extends in a protected enclosure and which is controlled from outside the enclosure. BACKGROUND OF THE INVENTION

Such a manipulator arm comprises a base attached to a wall of the enclosure, the base carrying an arm consisting of segments articulated together, at least one of these segments being telescopic. The end segment carries a tool, for example a gripping member for moving objects within the enclosure.

In severe environments, such as nuclear environments, the enclosure is delimited by a thick wall and the base consists of a sleeve which passes through the wall from one side to the other and in which mechanical controls of the cable type extend. , bevel gear shafts, cardan shafts, which control the manipulator arm. The mechanical controls are actuated from outside the enclosure, for example by electric motors, or by means of a master arm manipulated by the operator.

However, the manipulator arm generally comprises at least two segments articulated together, at least one of the segments being telescopic. The end segment which carries the gripping member comprises a wrist. In total, it is necessary to independently control several degrees of freedom, which makes it necessary to pass through the sleeve as many mechanical controls. The diameter of the sleeve must be large enough to allow the passage of all these mechanical controls. Moreover, the multiplication of mechanical controls makes the set particularly complex and heavy. There are also manipulator arms of which one or more degrees of freedom are controlled by means of electric motors arranged directly on the manipulator arm and powered by means of power cables which pass through the wall of the enclosure, for example through the sleeve passing through . This arrangement simplifies the design of the manipulator arm. However, such a manipulator arm which would be used under the same conditions as a nuclear speaker manipulator arm would have a singularly reduced lifetime. Indeed, the motors, and especially their associated electronics, do not support radiation well and degrade very quickly.

In a related field, document EPO 479 739 discloses a robot wrist that is removably attached to the robot arm and carries electric motors for handling a terminal clamp. The arm is provided with electrical and mechanical connection means (in this case screws) for mounting the wrist at the end of the arm. However, such a wrist can not be used in harsh environments such as a nuclear enclosure. Indeed, the change of the wrist imposes disassembly operations impossible to implement in a confined environment. OBJECT OF THE INVENTION The invention relates to a manipulator arm equipped with motors, but not suffering from the limitation invoked above.

BRIEF DESCRIPTION OF THE INVENTION

In order to achieve this goal, a manipulator arm having one or more segments including a terminal segment having an end adapted to carry a tool is provided, the manipulator arm having several degrees of freedom, one or more of said degrees of freedom being controlled. by one or more electric motors arranged on the manipulator arm, and in which the motor or motors are disposed on a removable end portion of the end segment, the removable end portion and the manipulator arm being equipped with quick connection / disconnection means for disassembly and placement of the removable end portion on the arm by remote control means.

Thus, the engines whose life is limited because of the aggressions they suffer in the enclosure in which the manipulator arm evolves are according to the invention grouped on a removable end portion that can be changed regularly, so that electric motors no longer limit the service life of the manipulator arm.

Furthermore, the quick connect / disconnect means allow the change of the removable end portion directly into the enclosure in which the manipulator arm is located, for example by means of another manipulator arm also disposed in the enclosure. Thus, the end portion can be quickly and easily changed, without human intervention, impossible in a confined space.

According to a particular embodiment, the connection / disconnection means comprise mechanical interfaces and electrical interfaces that can be engaged or disengaged by biasing in the longitudinal axis of the removable end portion. Thus, it suffices to grasp the removable end portion, for example by means of another manipulator arm present in the chamber, to exert traction in the longitudinal axis of the removable end portion to separate the of the arm.

Advantageously, the quick connection / disconnection means comprise locking means in position of the removable end portion on the arm. BRIEF DESCRIPTION OF THE FIGURES

The invention will be better understood in the light of the description of the appended figures, among which

- Figure 1 is a schematic sectional view of the end of a manipulator arm according to a particular embodiment of the invention; Figure 2 is a sectional view in perspective of a removable end portion according to a particular embodiment, showing the means of fast connection / disconnection;

FIG. 3 illustrates a phase of disconnection of the removable end portion inside an enclosure, with the aid of an additional manipulator arm;

- Figure 4 illustrates a disconnection phase of the removable end portion inside an enclosure, using a receiving cradle. DETAILED DESCRIPTION OF THE INVENTION Although this is in no way limiting, the description which follows relates to a manipulator arm 50 intended to be used, for example, in high-level armored cells (nuclear waste reprocessing plants), or in enclosures irradiated, such as that of the ITER reactor. Such a manipulator arm is subjected to intense nuclear radiation. The enclosure comprises a wall through which a sleeve on which the manipulator arm is connected. The manipulator arm has several segments articulated between them, some of which can be telescopic. The manipulator arm ends with a terminal segment 1, the end of which is illustrated in FIG.

The terminal segment 1 here comprises an anterior portion 2 which is directly connected to the rest of the manipulator arm. The position in the space of the anterior part 2 is determined by mechanical controls (not visible) which extend through the sleeve which crosses the wall of the enclosure. All this is well known and is only recalled as an illustration. Mechanical controls are generally used because they are much more resistant to radiation than electric motors, equipped with their power electronics if necessary.

The front portion 2 is hollow and internally receives a sliding support 3 on which, according to the invention, is attached a removable end portion 4. The removable end portion 4 is attached to the sliding support 3 by connection means / quick disconnect, which will be detailed later.

The removable end portion 4 here comprises a primary connecting tube 5 which is fixed to the sliding support 3. The primary tube 5 carries an extension 6 which is rotatably mounted on the primary tube along a longitudinal axis X. The extension 6 carries at its end a wrist 7 which receives a tool, in this case here a clamp 8. The terminal segment 1 of the manipulator arm 50 thus comprises several degrees of freedom:

a degree of sliding of the sliding support 3 in the front part 2;

a degree of rotation of the extension 6 in the primary tube 5;

three degrees of freedom of the clamp 8, namely a rotation about the transverse axis Y (seen here at the end), a degree of rotation about the Z axis, and a third degree of freedom by which the jaws of the forceps are approached or spread apart.

Note that the first degree of freedom cited is a degree of freedom external to the removable end portion 4, while the other degrees of freedom are degrees of freedom internal to the removable end portion 4. Here, and in accordance with the invention, all these degrees of freedom are controlled by electric motors which are all arranged, as well as their associated electronics, in the removable end portion 4. More precisely, the degree of external freedom sliding of the sliding support 3 is here controlled with the aid of an electric motor 10 disposed on the primary tube 5 and which comprises a shaft 11 of fluted end section adapted to penetrate into a homologous rotary sleeve 12 disposed on the sliding support 3 when the removable end portion 4 is in place on the sliding support 3. The rotating sleeve 12 controls the rotation of one of the pulleys of a driver 13 which cooperates with a cable 15 stretched inside the front part 2. A rotation of the shaft 11 causes a rotation of the sleeve 12, which causes a rotation of one of the pulleys of the driver 13, which causes the displacement of the driver 13 the lo ng of the cable 15, and hence the sliding of the sliding support 3 in the front portion 2. It will be necessary to ensure during the introduction of the removable end portion 4 that the shaft 11 is introduced into the rotating sleeve 12. There is then obtained, and in a very simple way, a mechanical connection between the shaft 11 and the driver 13. To ensure this sliding, it will be possible to use other known systems such as a toothed belt system, or a flexible transmission, as long as it is actuated by a motor disposed on the removable end portion 4. The degree of rotation of the extension 6 in the primary tube 5 is controlled by an electric motor 20 fixed on the elongate 6 and which drives a gear 21 which cooperates with a ring gear 22 disposed in the primary tube 5 to cause a rotation of the extension 6 vis-à-vis the primary tube 5 about the axis X. Finally, three electric motors, respectively

30, 31, 32, are arranged in the extension 6 to respectively control the rotation of the clamp 8 along the Y axis, the rotation of the clamp 8 along the Z axis, and the approximation or removal of the jaws of the clamp 8.

It will thus be noted that the onboard electric motors arranged on the removable end portion 4 make it possible to control the degrees of freedom internal to the removable end portion, such as the control of the gripper 8 or the rotation of the extension 6, but also degrees of freedom external to the removable end portion 4, such as the sliding in the front portion 2 of the sliding support 3 to which the removable end portion 4 is coupled. The use of electric motors all grouped in the removable end portion 4 has several advantages:

- The use of electric motors on the manipulator arm instead of mechanical controls running along the manipulator arm greatly simplifies the manipulator arm and reduces its diameter, and therefore its size. In addition, the use of electric motors considerably reduces the friction in the control chain of the degrees of freedom and thus contributes to increase the quality of the force feedback and the precision of the movements of the manipulator arm;

- The grouping of all the electric motors in the removable end portion allows the replacement thereof when the electric motors and / or their associated power electronics have reached their life limit. The possibility of replacing the removable end portion according to the invention makes it possible to prevent the weaker resistance of the motors and the electronics associated with the radiation from lasting for a longer period of time. life of the entire manipulator arm. The replacement of the removable end portion may be performed directly in the enclosure by means of another manipulator arm; - The power supply of all electric motors is significantly simplified, since all the electric motors are physically grouped together.

The interest of grouping the electric motors in the removable portion being thus explained, the way in which the removable end portion can be changed directly in the confined space is now explained in detail in relation to FIG. particular embodiment of the removable portion.

In Figure 2 is illustrated the end of a manipulator arm 150 whose removable end portion 104 is attached to the end segment 103 of the arm.

As before, the removable end portion 104 carries electric motors for actuating degrees of freedom internal or external to the end portion.

The end segment 103 of the arm and the removable end portion 104 are provided with quick connection / disconnection means 105 enabling the detachable end portion to be put in place and removed using an additional manipulator arm here. disposed in the enclosure.

For this purpose, it is appropriate that the quick connect / disconnect means allow disassembly and replacement of a removable end portion in the simplest possible manner. In particular, it is advantageous that the additional manipulator arm can grasp the removable end portion, and, on a simple pull, separate the removable end portion from the rest of the arm. For this purpose, the fast connection / disconnection means comprise here: on the end segment 103 of the arm, a female electrical connector 106 and a conical centering surface 110; on the removable end portion 104, a male electrical connector 107 homologous and a conical centering bearing 111 homologous.

Thus, and as shown in FIG. 3, it suffices to grasp the removable end portion 104 with the aid of the additional manipulator arm 200 and either with the manipulator arm 150 carrying the removable end portion. 104, or using the additional manipulator arm 200, to exert a traction in the longitudinal axis X of the removable portion to separate the removable end portion of the rest of the arm, the electrical connectors and the conical bearings disengaging simultaneously.

The removable end portion 104 thus disengaged is then deposited by the additional manipulator arm 200 on a cradle 201 disposed in the enclosure, and the additional manipulator arm seizes a new removable portion 104 'to bring it back on the manipulator arm . Just present the new end portion in the longitudinal axis, ensuring that it is angularly oriented so that the male and female connectors can interpenetrate.

The new removable end portion 104 'is then brought closer to the arm along said axis until the conical bearing surfaces cooperate to both center and immobilize the new removable end portion on the arm.

In this respect, and as can be seen in the figure

2, indexing means 115 comprising on the one hand fingers 116 carried by the removable end portion and on the other hand homologous cavities 117 carried by the end segment 103 guarantee the correct angular positioning of the removable end portion on the end segment 103 of the manipulator arm To secure the connection of the removable end portion 104 to the end segment 103, the quick connect / disconnect means are provided with locking means 120 comprising here a ring 121 rotatably mounted around the removable end portion 104, at the conical bearing surface 111 adjacent. The ring 121 internally has slopes for, during a rotation of the ring 121, to force the balls 122 radially in cavities dug in the portion of the removable portion carrying the conical bearing surface 111, which causes a tightening of the conical connection , and thus a lock of it. The locking ring 121 externally has teeth 123 allowing the rotation of the ring 121 to lock or unlatch the connection between the removable end portion 104 and the arm 103. For this purpose, and as can be seen in FIG. 3, the additional manipulator arm 200 is equipped with a motor 202 terminated by a toothed pinion to cooperate with teeth matching the locking ring 121, to rotate it and thus unlock the removable end portion 104.

According to a variant illustrated in Figure 4, the manipulator arm 250 carrying the removable end portion 204 is now alone inside the enclosure. To disconnect the removable end portion 204, a receiving cradle 300 equipped. The manipulator arm 250 brings the removable end portion 204 onto the equipped cradle 300. Retaining means 301 presses the removable end portion to prevent its movement. On the equipped cradle 300 is disposed an unlocking motor 302 equipped with a pinion to rotate the locking ring 221 and thus unlock the removable end portion 204 of the manipulator arm 250. It is then sufficient to move the manipulator arm 250 to disconnect the removable end portion, which then remains in position on the cradle.

Alternatively the equipped cradle may be provided swiveling or movable to facilitate the presentation of the removable end portion on the cradle.

Thus, it is possible to connect / disconnect the removable end portion directly into the enclosure, using remote-controlled means, which avoids any intervention in the enclosure, or any output of the arm of the 'pregnant.

Alternatively, the locking ring 121,221 may be actuated by an electric motor mounted directly in the removable end portion 104,204. It will then suffice to control this motor prior to disassembly of the removable end portion to unlock the connection between the removable end portion and the arm, the unlocking motor is still powered via the electrical connectors.

The means of quick connection / disconnection may be of any known type, as long as they provide both a mechanical connection and an electrical connection, simultaneous as illustrated here or sequentially, which can be implemented using a additional manipulator arm, or more generally, using remote-controlled means. For example, the connection / disconnection means may be of the motor-operated automatic connection and disconnection type installed in the removable end portion. It is then sufficient to present it in line with a cradle disposed in the enclosure, to control the means of quick connection / disconnection to cause separation of the removable end portion which is then received on the cradle. The end of the arm thus released is brought opposite another removable end portion held in position on another cradle, then is forced to connect to the removable end portion by a longitudinal approaching force. Thus, the connection / disconnection is also by remotely controlled means, although purely internal to the arm, by one actuation of the disconnection motor.

The invention is not limited to what has just been described, but on the contrary encompasses any variant within the scope defined by the claims.

In particular, it can be provided that other degrees of freedom are controlled by electric motors embedded in the removable end portion, such as a rotation in articulation between the terminal segment and anterior segment, or if the part previous of the terminal segment is telescopic, the control of this telescopic movement.

Moreover, although in the illustrated examples, the power electronics associated with the motors is embedded in the removable end portion, the power electronics may be disposed elsewhere than in the removable end portion, for example to the outside of the enclosure in which the manipulator arm evolves.

In addition, it will obviously be possible to interpose an extension between the removable end portion and the arm, the extension having at its two ends homologous connection / fast disconnection means allowing it to be interposed easily by remote control means between the arm and the removable end portion.

Claims

1. Manipulator arm comprising one or more segments including a terminal segment (1) having an end adapted to carry a tool (8), the manipulator arm having several degrees of freedom, one or more of said degrees of freedom being controlled by one or more electric motors (30,31,32) arranged on the manipulator arm, the electric motor or motors being arranged on a removable end portion (4) of the terminal segment, characterized in that the terminal segment and the removable end portion are equipped with quick connect / disconnect means (105) operable by remote control means.

2. manipulator arm according to claim 1, wherein the fast connection / disconnection means comprise mechanical connection means (110,111) and electrical connection means (106,107) which are connected or disconnected simultaneously during installation or a separation of the removable end portion.

The manipulator arm of claim 1, wherein the quick connect / disconnect means is arranged to allow disconnection of the removable end portion in response to traction of the removable end portion along a longitudinal axis thereof. this .

4. Manipulator arm according to claim 1, wherein the fast connection / disconnection means comprise indexing means (116,117) of the removable end portion relative to the terminal segment of the manipulator arm.

5. Manipulator arm according to claim 1, wherein the fast connection / disconnection means comprise locking means of the removable end portion in position on the terminal segment.

6. Manipulator arm according to claim 1, wherein at least one of the electric motors disposed on the removable end portion makes it possible to control at least one degree of internal freedom at the removable end portion (4).

7. manipulator arm according to claim 2, wherein the internal degree of freedom is a rotation along a longitudinal axis (X) of an extension carried by the removable end portion.

8. Manipulator arm according to claim 1, wherein at least one of the electric motors disposed on the removable end portion makes it possible to control at least one degree of freedom external to the removable end portion (4).

9. manipulator arm according to claim 4, wherein the external degree of freedom is a telescopic sliding of the removable end portion in the end segment which carries the removable end portion.

10. A method of using a manipulator arm according to one of the preceding claims, wherein the terminal end portion is placed on the terminal segment or removed thereof by means of an additional manipulator arm.