WO2009037149A1

WO2009037149A1 - Improvement in a robot capable of spreading legs relative to the vertical

Info

Publication number: WO2009037149A1
Application number: PCT/EP2008/061909
Authority: WO
Inventors: Bruno Maisonnier; David Gouaillier
Original assignee: Aldebaran Robotics
Priority date: 2007-09-19
Filing date: 2008-09-09
Publication date: 2009-03-26
Also published as: FR2921008A1; FR2921008B1

Abstract

The invention relates to a robot (1) that comprises a first leg (3a), a second leg (3b), and an articular assembly (7) connected to the first leg (3a) of the robot by a first axle (9) and to the second leg (3b) of the robot by a second axle (8), the articular assembly being arranged for spreading the first leg relative to the second leg, characterised in that the first axle (9) and the second axle (8) are rotatingly mobile about their respective axial directions and in that the articular assembly (7) includes coupling means (14, 18, 15, 17, 19) arranged for rotatingly coupling the first axle (9) and the second axle (8) so that, when the first axle (9) is rotated in one direction, the second axle (8) is rotated in the other direction.

Description

IMPROVING A ROBOT THAT CAN SHIFT YOUR LEGS FROM THE VERTICAL

The invention relates to a robot comprising a first leg, a second leg and an articulated assembly connected to the first leg of the robot by a first axis, and to a second leg of the robot by the second axis, the articulated assembly being arranged to spread the first leg relative to the second leg.

Such a robot exists in the state of the art and is shown in FIG. 1. Such a known robot 1 comprises an articulated assembly 2 corresponding to an articulation of the pelvis / hip / trunk block of the robot. The hinge 2 is connected to a first leg 3a, a second leg 3b and a trunk 4. In FIG. 1, the first leg 3a, the second leg 3b, and the trunk 4 are oriented along a vertical axis. At the junction between the articulation 2 and each of the legs 3a and 3b, three degrees of freedom are controlled by three motors in the vertical orthogonal directions A-A ', horizontal forward B-B', and horizontal lateral CC. At the junction between the articulation 2 and the trunk 4, two degrees of freedom are controlled by two motors in the vertical directions D-D ', and lateral horizontal E-E'. The two legs 3a and 3b are vertical along the axis D-D ', corresponding to the axis of the trunk 4 of the robot.

Therefore, the articulation of the pelvis / hip / trunk block requires, so that the robot performs most natural movements, eight degrees of freedom, so eight engines.

Such a number of engines is both expensive and bulky in the robot.

In addition, with the known robots, this number of engines is necessary to allow the robot to rise once on the ground, and, unless you have very long arms that can remove the E-E 'engine, it is complex to allow a robot to get up if it fell.

A problem solved by the invention is to allow the robot to perform in a simple manner, a large number of movements, and in particular to get up when it fell, with a small number of engines.

Another problem solved by the invention is to allow the robot to spread the legs with a reduced number of engines.

This problem is solved by the fact that, in the robot described above comprising a first leg, a second leg and an articulated assembly connected to the first leg of the robot by a first axis, and to a second leg of the robot by the second axis, the articulated assembly being arranged to move the first leg relative to the second leg, wherein the first axis and the second axis are rotatable about their respective axial directions, and the articulated assembly comprises means coupling means arranged to couple the first axis and the second axis in rotation so that when the first axis is rotated in one direction, the second axis is rotated in the other direction.

Thanks to the invention, the first axis and the second axis can be rotated in a coupled manner, one in one direction and the other in the other direction. Therefore, this movement is likely to cause a distance of the legs of the robot relative to the vertical. As a result, by virtue of the aforementioned coupling, it is possible to reduce the number of motors required to separate the legs of the robot, so that the robot can perform a large number of movements with a reduced number of motors. Advantageous embodiments of the invention are described below.

Preferably, the first axis is inclined relative to the direction of the first leg, and the second axis is inclined relative to the direction of the second leg. In this way, it is ensured that the legs move apart when the first axis and the second axis are rotated in a coupled manner.

Preferably, the first axis is inclined relative to the first leg of an inclination angle of between 0 degrees and 90 degrees, the inclination angle being equal to 0 degrees or 90 degrees.

Similarly, the second axis may be inclined relative to the second leg of an inclination angle of between 0 degrees and 90 degrees, the inclination angle being equal to 0 degree or 90 degrees.

In particular, the angle of inclination of the first axis relative to the direction of the first leg may be an angle of between 30 and 60 degrees, in particular 45 degrees and the angle of inclination of the second axis with respect to the direction the second leg can be an angle between 30 and 60 degrees, including 45 degrees.

The previously mentioned inclinations make it possible to adapt the spacing of the legs when the first axis and the second axis are rotated in a coupled manner.

In particular, when the first leg and the second leg are vertical, the first axis and the second axis are inclined relative to the vertical axis, the inclination may be as previously described. In this way, especially when the robot comprises a vertical trunk, thanks to the coupling mentioned above and to this inclination, the rotation of the first axis and the second axis causes a separation of the legs relative to the vertical and, when the The robot's legs remain fixed to the ground, also a trunk tilt forward. This embodiment therefore makes it possible to eliminate a possible motor at the junction between the articulation 2 and the trunk 4 in the horizontal lateral direction EE 'to incline the trunk towards the front. This makes it easy for the robot to bend with a small number of motors. The robot can then easily get up if it has fallen. Other natural movements can also be achieved through the invention.

According to this embodiment, the lower the angle of inclination, the less the robot leans forward when the first axis and the second axis are rotated and therefore when the legs of the robot deviate. The steeper the angle of inclination, the more it leans. The angle of inclination is then adapted according to the desired degree of spacing of the legs and thus the desired degree of inclination for the trunk when the legs apart.

Preferably, the coupling means comprise a first pinion actuable by a motor, the first axis being able to be rotated in one direction by the rotation of the first pinion, the coupling means further comprising a second gear, the second axis being capable of being rotated in the other direction by the rotation of the second pinion, the first pinion being adapted to engage the second pinion when the motor actuates the first pinion so as to couple the first axis and the second pin by rotation.

In this embodiment, the first axis can be attached to the first gear, and the second axis can be attached to the second gear. Preferably, the second gear is a conical gear, and the first gear comprises at least a conical portion so as to engage the second gear.

The first gear can then be oriented 90 degrees relative to the second gear.

The motor can be connected to the first gear by at least one gearbox.

According to one embodiment, the first pinion comprises a conical toothed portion and a cylindrical toothed portion.

Thanks to this embodiment, the first pinion makes it possible to eliminate the parts necessary for embedding a pinion on an axis. This embodiment is particularly advantageous for actuating the first axis and the second axis previously defined for the aforementioned robot because of the space gain at the joint.

One aspect of the invention also relates to a pinion as previously defined regardless of its use in a robot gear to move the first leg and the second leg away from the vertical.

The invention thus relates, in a second aspect, to a pinion comprising a conical toothed portion and a cylindrical toothed portion.

Preferably, the cylindrical toothed portion and the conical toothed portion are positioned in a same plane circularly around the first pinion. In this case, the cylindrical toothed portion may be arranged on a half-turn of the first pinion and the cylindrical toothed portion may be arranged on the other half-turn of the first pinion.

Preferably, the conical toothed portion of the first pinion is arranged to mesh with the second pinion.

Preferably, the articular assembly comprises a single motor connected to the coupling means, so that when the motor is activated, the first axis is rotated in one direction, and the second axis is rotated in the other direction. meaning.

The robot described above may advantageously be a humanoid robot having a trunk connected to the first leg and the second leg, wherein the articular assembly connects the trunk to the first leg and the second leg.

Embodiments of the invention will now be described in detail with reference to the appended figures in which:

FIG. 2 represents an embodiment of a humanoid robot according to the invention;

FIG. 3 shows an embodiment of a gear arrangement included in the joint of the pelvis / hip / trunk block of the humanoid robot shown in FIG.

1;

FIG. 4 shows another embodiment of a gear arrangement included in the joint of the pelvis / hip / trunk block of the humanoid robot shown in FIG. 1;

FIG. 5 shows a detailed view of a gear used in the illustrated embodiment FIG.4. Unless otherwise indicated, in the figures mentioned above, identical references refer to similar technical characteristics.

Illustrated FIG. 2, a robot 1 according to the invention comprises a hinge block pelvis / hip / trunk 2, connected to a left leg 3b and a right leg 3a. The pelvic / hip / trunk joint block 2 is also connected to a trunk 4. The robot 1 is for example a humanoid robot and may comprise a head, two legs 10a and 10b associated with the legs 3a and 3b, two arms and hands.

The left leg 3b and the right leg 3a are vertical. It is understood that the legs of the robot can also be inclined relative to the vertical while allowing the robot 1 to stand up.

The articulation connecting the pelvic / hip / trunk joint block 2 to the leg 3b is now described in more detail. This articulation 5 comprises a first degree of freedom along an axis B-B 'horizontal forward, and a second degree of freedom along a lateral horizontal axis C-C. These degrees of freedom are each controlled by a motor not shown.

The articulation 5 also comprises a degree of freedom G-G 'oriented at 45 degrees with respect to the vertical axis of the leg 3b of the robot 1 towards the trunk 4.

In the same way, the articulation 6 connecting the pelvic / hip / trunk joint block 2 to the leg 3a comprises a first degree of freedom along the axis BB 'horizontal forward, and a second degree of freedom according to the horizontal lateral axis CC, and a degree of freedom F-F 'oriented at 45 degrees with respect to the vertical axis of the leg 3b of the robot 1 towards the trunk 4. When the trunk 4 of the robot is also vertical, the degrees of freedom GG 'and FF' are also oriented each 45 degrees relative to the axis of the trunk 4 of the robot 1.

A joint 7 connects the articulation block pelvis / hip / trunk 2 to the trunk 4.

An axis 8 connects the articulation 5 to the articulation 7 according to the degree of freedom G-G ', and an axis 9 connects the articulation 6 to the articulation 7 according to the degree of freedom F-F'. The axes 8 and 9 are symmetrical with respect to the vertical and inclined 45 degrees with respect to the vertical, that is to say with respect to the direction of the legs 3a and 3b of the robot 1.

It is understood that other inclinations with respect to the directions of the legs are possible within the scope of the invention, and in particular inclinations between 0 and 90 degrees, preferably between 30 and 60 degrees. These inclinations can easily be adapted, especially when the legs 3a and 3b of the robot 1 are not vertical.

The degrees of freedom GG 'and FF' are degrees of freedom in rotation so that the axes 8 and 9 are able to be rotated about their respective axial directions, one in a direction of rotation, and the other in the other direction of rotation.

The shafts 8 and 9 are fixedly attached to the legs 3b and 3a respectively, at the respective joints 5 and 6 so that when the shafts 8 and 9 are rotated in opposite directions around their respective axial directions, the legs 3a and 3b rotate according to the same rotational movement as the axes 8 and 9. This therefore causes a spacing of the legs 3a and 3b relative to the vertical. A motor positioned at the hinge 7 allows this rotation of the axes 8 and 9 in opposite directions. This motor and its arrangement with respect to the axes 8 and 9 will be described in more detail with reference to FIGS. 3 and 4.

When the motor positioned at the hinge 7 is activated, the two axes 8 and 9 are rotated about their respective axial directions. As a result, the legs 3a and 3b rotate and deviate relative to the vertical axis defined by the trunk. When the legs 3a and 3b are placed on the ground, for example by means of respective feet 10a and 10b, the spacing of the legs 3a and 3b also causes the trunk 4 to incline forwardly about the axis E -E.

Thus, according to the invention, and thanks to the fact that the axes 8 and 9 are rotatable about their respective axial directions and in particular inclined by approximately 45 degrees towards the articulation 7 with respect to the directions of the legs 3a and 3b, it is possible to tilt the robot forward by activating a single motor. Other angles of inclination relative to the directions of the legs are possible in the range between 0 and 90 degrees. In particular, the lower the angle of inclination, the less the robot leans forward when the first axis and the second axis are rotated and thus when the legs of the robot deviate. On the contrary, the stronger the angle of inclination, the more it leans. The angle of inclination is then adapted according to the degree of inclination desired for the trunk when the legs apart. An angle between 30 and 60 degrees, for example 45 degrees, is well suited.

We now describe in more detail the articulation 7 and more particularly the action of the engine mentioned above on the legs 3a and 3b of the robot with reference to FIG.3 and FIG.4. According to a first embodiment illustrated FIG. 3, this hinge 7 comprises a motor 1 1, capable of rotating a set of cylindrical reducers 1 2 connected gear device. The gear device comprises a cylindrical pinion 1 3 directly meshing with one of the cylindrical reducers 1 2. The cylindrical pinion 1 3 is connected to a first conical pinion 14 by a bridge 1 6. The first pinion gear 14 is capable of driving a second bevel gear 1 5, the first bevel gear 14 being oriented at 90 degrees to the second bevel gear 1 5.

The bevel gears 14 and 15 are respectively connected to the axes 9 and 8 and are respectively oriented along the axes F-F 'and G-G'. They are therefore each oriented at an angle of 45 ° with respect to the di rections of the legs 3a and 3b. As mentioned previously, other nibrations are possible, and in particular inclinations between 30 and 60 degrees.

In operation, when the motor 1 1 is activated, the cylindrical pinion 1 3 is rotated through the reducers

12. The rotation of the pinion 1 3 causes, thanks to the bridge 1 6, the rotation of the pinion 14 which in turn drives the axis 9 in rotation in one direction.

When the bevel gear 14 is rotated, it also drives the bevel gear 1 5 so as to rotate the axis 8 in a direction opposite to the direction of rotation of the axis 9. The gear set previously described allows therefore a coupling in rotation of the axes 8 and 9.

In this way, as described above, with a single motor 1 1 and the coupling of the axes 8 and 9, it is possible to separate the legs 3a and 3b.

We now describe a second embodiment of a gear arrangement included in the articulation 7 of the block pelvis / hip / trunk 7 of the humanoid robot 1 described above with reference to FIG. 2.

As previously, the hinge 7 comprises a motor 1 1, connected to gearboxes 1 2, themselves connected to a cylindrical pinion 1 3. In this embodiment, the cylindrical pinion 1 3 does not include a bridge and causes directly a pinion 1 8 having a toothed cylindrical portion in contact with the cylindrical pinion 1 3. The same pinion 1 8 also comprises a tapered toothed portion 1 9 to mesh with a bevel gear 1 5. In this way, the pinions 1 5 and 1 8 are oriented relative to each other by 90 degrees, and are each oriented 45 degrees with respect to the vertical axis of the trunk 4. As in the embodiment previously described, the axes 9 and 8 are respectively fixed to the gears 1 8 and 1 5 and fixed respectively to the legs 3a and 3b so that it is possible to spread the legs 3a and 3b of the robot while allowing to lean the trunk 4 by a simple activation of the engine 1 January. As before, the gears described above allow rotation coupling of the axes 8 and 9.

This embodiment using a conico-cylindrical gear 18 having a first cylindrical toothed portion and a second conical toothed portion has the particular advantage of eliminating the bridge 1 6 and thus to gain space in the joint 7.

The conical-cylindrical pinion 18 is now described in greater detail with reference to FIG. 5. This conico-cyli ndric gear 1 8 is of a new type since at the same level axially, it comprises a conical toothed portion, for example on a half-turn, and a cylindrical toothed portion, for example on the other turn around.

Thus, it is the same part that receives power from the reduction chain and transmits it to the orthogonal shaft. As mentioned previously, this pinion thus allows to remove the parts necessary for the embedding of a pinion on an axis.

In FIG. 5, the conic-cylindrical pinion 18 therefore comprises, on its circumference, a conical toothed portion 19 over about one half-turn and a cylindrical toothed portion 17 about one-half turn. The tapered toothed portion 19 and the cylindrical toothed portion 17 are separated by diametrically opposed flat areas 20a and 20b.

It is understood that according to the use of this gear, the distribution of the conical toothed portion 1 9 relative to the cylindrical toothed portion 1 7 can be changed.

Claims

1. Robot (1) comprising a first leg (3a), a second leg (3b) and an articulated assembly (7) connected to the first leg (3a) of the robot by a first axis (9), and to the second leg (3b) of the robot by a second axis (8), the articulated assembly being arranged to move the first leg relative to the second leg characterized in that the first axis (9) and the second axis (8) are movable in rotation about their respective axial directions, and the articular assembly (7) comprises coupling means (14, 18, 15, 17, 19) arranged to couple the first axis (9) and the second axis (8) in rotation so that when the first axis is rotated in one direction, the second axis is rotated in the other direction.

2. Robot according to claim 1, wherein the first axis is inclined relative to the direction of the first leg, and the second axis is inclined relative to the direction of the second leg.

3. Robot according to claim 2, wherein the first axis is inclined relative to the first leg of an inclination angle between 0 degrees and 90 degrees, the angle of inclination being equal to 0 degrees , or at 90 degrees.

4. Robot according to claim 2 or 3, wherein the second axis is inclined relative to the second leg of an inclination angle of between 0 degrees and 90 degrees, the inclination angle being equal neither to 0 degrees, or 90 degrees.

The robot according to claim 3 or 4, wherein the angle of inclination of the first axis with respect to the direction of the first leg is an angle of between 30 and 60 degrees, and the angle The inclination of the second axis relative to the direction of the second leg is at an angle of between 30 and 60 degrees.

6. Robot according to one of the preceding claims, wherein the first leg and the second leg are vertical.

7. Robot according to one of the preceding claims, wherein the first axis (9) is fixedly fixed to the first leg (3a) and the second axis (8) may be ntenu fixed to the second leg (3b).

8. Robot according to one of the preceding claims, wherein the coupling means (14, 1 8, 1 5, 1 7, 1 9) comprise a first pinion (14, 18) operable by a motor (1 1), the first axis (9) being rotatable in one direction by the rotation of the first gear (14, 1 8), the coupling means (1 1, 14, 1 8, 1 5, 1 7, 1 9) further comprising a second gear (1 5), the second axis (8) being able to be rotated in the other direction by the rotation of the second gear (1 5), the first gear (14, 1 8) being able to engage the second pinion (1 5) when the motor (1 1) actuates the first pinion so as to couple the first axis (9) and the second axis (8) in rotation.

9. Robot according to the preceding claim, wherein the first axis (9) is fixed to the first pinion (14, 1 8), and the second axis (8) is fixed to the second pinion (1 5).

A robot according to claim 8 or 9, wherein the second gear (15) is a bevel gear, and the first gear (14, 18) comprises at least one conical portion so as to engage the second gear.

11. Robot according to one of claims 8 to 10, wherein the first pinion is oriented 90 degrees relative to the second pinion.

12. Robot according to one of claims 8 to 11, wherein the motor (11) is connected to the first gear by at least one gear (12).

13. Robot according to one of claims 8 to 12, wherein the first pinion (18) comprises a conical toothed portion (19) and a cylindrical toothed portion (17).

14. Robot according to claim 13, wherein the cylindrical toothed portion (19) and the conical toothed portion (17) are positioned in a same plane circularly around the first pinion.

15. Robot according to the preceding claim, wherein the cylindrical toothed portion is arranged on a half-turn of the first pinion and the cylindrical toothed portion is arranged on the other half-turn of the first pinion.

16. Robot according to one of claims 13 to 15, wherein the conical toothed portion (19) of the first pinion (18) is arranged to mesh the second pinion (15).

Robot according to one of the preceding claims, in which the joint assembly (7) comprises a single motor (11) connected to the coupling means, so that when the motor (11) is activated, the first axis ( 9) is rotated in one direction, and the second axis (8) is rotated in the other direction.

Robot according to one of the preceding claims, wherein the robot is a humanoid robot having a trunk connected to the first leg and the second leg, in which the articular assembly (7) connects the trunk to the first leg and the second leg.