Actuation of a hand to be provided on a humanoid robot

1. A hand intended for a humanoid robot, the hand comprising:

a palm;

a plurality of fingers, each of the fingers being configured to be displaced in relation to the palm between a position of rest maintained by a spring effect and a compressed position obtained by driving a link part between said finger and the palm, countering the spring effect; and

a motorized shaft linked to the link part of each of the fingers and configured to displace, from the position of rest to the compressed position, at least one first finger of the fingers by rotation of the motorized shaft in a first direction of rotation and at least one second finger of the fingers by rotation of the motorized shaft in a second direction of rotation opposite the first direction of rotation,

wherein two of the fingers are located on the palm so as to be like a thumb and an index finger,

wherein, upon rotation of the shaft in the first direction, the index finger or the thumb is maintained in the position of rest, and

wherein, upon rotation of the shaft in the second direction, all the fingers of the hand are displaced to the compressed position so as to represent, with the palm, a closed hand.

2. The hand as claimed in claim 1 , wherein the shaft comprises:

a first radial profile on a first portion of a circumference of the shaft configured to drive the link part of a finger of the fingers upon a rotation of the shaft in the first direction of rotation; and

a second radial profile on a second portion of the circumference of the shaft configured to drive the link part of the finger upon a rotation of the shaft in the second direction of rotation.

3. The hand as claimed in claim 2 , wherein one of the fingers is configured to be displaced by rotation of the shaft in only one of the first and second directions of rotation.

4. The hand as claimed in claim 2 , wherein the fingers in the position of rest represent, with the palm, an open hand.

5. The hand as claimed in claim 2 , wherein the link part of one of the fingers comprises a cable linked on one side to the finger and on the other side to the shaft by means of a crimping housed in a cavity of the shaft, the cable passing radially through the shaft through a duct linking the cavity and an end of one of the radial profiles, such that the rotation of the shaft in one direction of rotation winds the cable on said radial profile, driving the displacement of the finger by pulling the cable.

6. The hand as claimed in claim 5 , wherein said radial profile is substantially circular over a portion of circumference close to a semi-circle centered on an axis of rotation of the shaft, and on which the cable of a finger can be wound, a diameter of the radial profile determining the travel of the cable and an amplitude of the displacement of the finger between the position of rest and the compressed position.

7. The hand as claimed in claim 5 , wherein the link part of one of the fingers comprises a crimping mounted to rotate freely in the cavity centered on an axis of rotation of the shaft, the duct being configured to allow the cable to pass through the shaft radially all along a radial profile such that the finger is maintained in the position of rest upon a rotation of the shaft.

8. The hand as claimed in claim 5 , wherein the shaft has several first and second radial profiles arranged in succession according to an axis of rotation of the shaft, for the simultaneous displacement of several fingers.

9. The hand as claimed in claim 5 , wherein two of the fingers are identical and linked to the shaft by two cables of identical lengths and two identical crimpings, the shaft comprising two housing cavities formed in the shaft at two distinct distances from an axis of rotation of the shaft, making it possible to locate the two identical fingers in the palm of the hand at two distinct distances from the axis of rotation of the shaft.

10. A humanoid robot equipped with a hand as claimed in claim 1 .