Robonaut Head Subsystem

NASA Meatball

Robonaut

Subsystems

Hand
Arms
Head
Controls
Avionics
Telepresence

The Robonaut head has two eyes and a neck with two degrees of freedom-- the ability to nod up and down and shake left and right.

Head

Robonaut's head includes an articulated neck that allows the teleoperator to point Robonaut's face. The head holds two small color cameras that deliver stereo vision to the operator's helmet display, yielding a form of depth perception. The interocular spacing of the cameras is matched totypical human eye spacing, with a fix vergence at arm's reach. The neck drives are commanded using a 6 axis Polhemus sensor mounted on the teleoperator's helmet, and can track the velocities of typical human neck motions.

Like the arms, the neck's endoskeleton is covered in a fabric skin,which is fitted into and under the helmet. The helmeted approach is unusual in the robotics world, where cameras are typically mounted in exposed locations on pan-tilt-verge units. Robonaut's requirements for a rugged design, working with astronauts in cluttered environments drove the design towards a better protection system, such as the helmets that humans where here on Earth. The helmet is made of anepoxy resin, "grown" using a stereo lithography machine at the Johnsonspace center. As you can see, the design was inspired by Centurian armor, giving Robonaut some attitude.

The neck joints are similar to the joints and are controlled with the same real-time control system. Their kinematics is based on a pan-tilt serial chain, with the first rotation about Robonaut's spine, and then a pitch motion about a lateral axis. The pitch motion axis does not pass through the camera sensors, but is instead 3 inches below, like the Atlas joint in the human neck. This offset (actually aD-H link length) allows the cameras to translate forward, letting Robonaut see down over its chest.



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Last modified: Wednesday, 25-Mar-11 10:07:00 PM CDT

Web Editor: Jerry Woodfill / NASA, Mail Code ER7, NASA JSC, Houston, TX 77058

A service of the Software, Robotics and Simulation Division, Rob Ambrose, Chief.