Patents on the soles of your shoes...: Oh, patents! Nao’s hands

Nao, Softbank Robotics' humanoid, has two hands, each with a palm, two fingers and a thumb, and you might be wondering why?

The design of humanoid hand function mimicking human hand function is quite a task. A human hand has 27 degrees of freedom with 27 bones and 14 joints. Humanoid hand movements or degrees of freedom are controlled with actuators which, for all practical purposes of space and coordination, are best kept to a minimum. Indeed, the two Softbank Robotics humanoid hand patent families listed below each address the issue of actuation relative to degrees of freedom, and in particular of humanoid hands. The design goal explained in the patents is underactuation. That is, a design where the degrees of freedom (N) is always greater than the number of actuators, expressed as N>A, and the greater the underactuation, the better. The degree of underactuation is thus calculated as N-A, the difference between degrees of freedom and the number of actuators:

In the first patent family, the solution found for achieving high underactuation was a spreader able to distribute the force of a single actuator across all digits. So that one actuator is actually controlling 14 degrees of freedom for a humanoid hand with 4 fingers and one thumb, a design solution that even enables the digits to adapt to the shape of an object grasped. However, this design solution does not actuate digits separately. And the inventors not only wanted humanoid hands to grasp objects and to adapt to their shape, they also wanted for humanoid hands to function in communication. So a second family of patents discloses high underactuation, which additionally achieves separate digit movement, such as for example, pointing with an index, or a "thumbs-up" as in the iconic "I like".

The two humanoid hand patent families are listed below, with US patent abstracts for each family, and patent drawings from each of the patent families. The first Figure drawing shows the spreader, within the humnoid palm, distributing the actuation force of a single actuator across digits, and Figure 2c shows separate digit movement, two digits bent, one straight, also underactuated by a single actuator. A short video is also included presenting Romeo, another much larger Softbank Robotics humanoid, designed as a home companion, with clearly independent thumb movement.

Patent Family I

A hand intended for a humanoid robot comprises a palm and several fingers that are motorized relative to the palm. According to the invention, the hand comprises an actuator common to several fingers and a spreader making it possible to distribute a force exerted by the actuator toward the fingers. [Abstract US2016325437 (A1)]

US2016325437 (A1) ― 2016-11-10 - Actuation of a hand intended for being provided on a humanoid robot
JP2017503668A ― 2017-02-02 - Operation of intended hand provided on humanoid robots
AU2015208156 (A1) ― 2016-08-04 - Actuation of a hand intended for being provided on a humanoid robot
CA2937582 (A1) ― 2015-07-30 - Actuation of a hand intended for being provided on a humanoid robot
EP3105018 (A1) ― 2016-12-21 - Actuation of a hand intended for being provided on a humanoid robot
FR3016542 (A1) ― 2015-07-24- Actionnement d'une main destinée à équiper un robot à caractère humanoïde
KR20160120732 (A) ― 2016-10-18 - Actuation of a hand intended for being provided on a humanoid robot
MX2016009357 (A) ― 2017-04-13 - Actuation of a hand intended for being provided on a humanoid robot
NZ722309 (A) ― 2017-08-25 - Actuation of a hand intended for being provided on a humanoid robot
SG11201605955V (A) ― 2016-09-29 - Actuation of a hand intended for being provided on a humanoid robot
WO2015110521 (A1) ― 2015-07-30 - Actuation of a hand intended for being provided on a humanoid robot

Patent Family II

A hand intended for a humanoid robot comprising a palm and several fingers, each of the fingers being able to be displaced in relation to the palm between a position of rest maintained by spring effect and a compressed position obtained by driving a link part with the palm countering the spring effect, comprises a motorized shaft, linked to the link part of each of the fingers, and configured to respectively displace at least one first finger and at least one second finger, from the position of rest to the compressed position, by rotation of the motorized shaft respectively in a first direction of rotation and in an opposite direction. [Abstract US20170043486A1]

US20170043486A1 -- Actuation of a hand to be provided on a humanoid robot
AU2015257679 (A1) ― 2016-11-10 - Actuation of a hand to be provided on a humanoid robot
CA2948073 (A1) ― 2015-11-12 - Actuation of a hand to be provided on a humanoid robot
EP3140085 (A1) ― 2017-03-15 - Actuation of a hand to be provided on a humanoid robot
FR3020775 (A1) ― 2015-11-13 - Actuation of a hand to be provided on a humanoid robot
JP2017514712 (A) ― 2017-06-08 - Actuation of a hand to be provided on a humanoid robot
KR20170007351 (A) ― 2017-01-18 - Actuation of a hand to be provided on a humanoid robot
MX2016013597 (A) ― 2017-06-29 - Actuation of a hand to be provided on a humanoid robot
SG11201608727V (A) ― 2016-12-29 - Actuation of a hand to be provided on a humanoid robot
WO2015169886 (A1) ― 2015-11-12 - Actuation of a hand to be provided on a humanoid robot