Page 230 - Robots Androids and Animatrons : 12 Incredible Projects You Can Build

where significant contributions can be made. Before undertaking
this project it is important to realize that an HMD that supplies
stereo images to the user will be needed to view stereo images
transmitted from the T-bot.
The small size of the miniature video cameras is good for stereo-
graphic imaging. It allows two cameras to be positioned side by
side at the same interocular distance (IOD) as that of human eyes.
To be more specific, the average interocular distance (pupil to
pupil) for adult humans is about 63 mm. The camera’s lenses can be
positioned, from center to center, this same distance apart to mimic
the IOD humans use for depth perception. The transmitters for
each camera must be tuned to transmit on different frequencies.
This allows the HMD video receivers to accurately display the right
eye image to the right eye and the left eye image to the left eye.
Seeing in stereo from the Golem provides the operator with depth
perception when he or she is driving. Stereo-vision becomes increas-
ingly more important when depth perception is needed, for instance
when using a robotic arm. Being able to see the manipulator (robot
arm) move along the Z axis in a three-dimensional (3D) coordinate
system (X, Y, and Z) allows for efficient operation.

It is difficult for an operator to efficiently use robotic arms via 209
telepresence when the Z dimension (depth) is lost in a monocular
view. Operators are forced to gently bump into objects to approx-
imate the robotic manipulator’s location along the Z axis.

The same is true when driving a telepresence car. One quickly
loses depth perception, and it becomes difficult to determine how
far ahead of the vehicle something is.
When the stereo system is set up, the operator of the vehicle will see
the T-bot’s environment as a 3D picture. However, the stereo image
transmitted will not contain the very important convergence clues.
Much of our distance reckoning incorporates convergence clues we
get from our eyes. Convergence is the angle our eyes rotate inward
when viewing an object. An object very close to us will cause our
eyes to rotate inward. In contrast, when viewing an object that is
far away, our eyes look straight ahead. The brain automatically
brings this convergence information to bear in calculating distance.
The stereo video cameras are in a fixed position looking straight
ahead. To add convergence clues would require eye tracking engi-
neering. A feedback-providing HMD would need to constantly
ascertain the operator’s eye convergence. The eye tracking
(convergence) information would be transmitted to servo motors

Team LRN Telepresence robot