Page 279 - Concise Encyclopedia of Robotics

Perfect
100
Percent of units working
Excellent
80
Good
60
Fair
40
Poor
20
0 Remote Control
Time
Start
of
service
Reliability
REMOTE CONTROL
Robots can be operated from a distance by human beings. Computers can
also be controlled from places far removed from the machines themselves.
This is done by means of remote control.
A simple example of a remote-control system is the control box for a
television (TV) set. Another example is a transmitter used to fly a model
airplane. The TV control employs infrared (IR) radiation to carry the
data. The model airplane gets its commands via radio signals. In this
sense, both the TV set and the model airplane are robots.
Remote control can be done by wire, cable, or optical fiber links. Under-
sea robots have been operated in this way.A person sits at a terminal in the
comfort of a boat or submarine bubble and operates the robot, watching a
screen that shows what the robot “sees.”This is a crude form of telepresence.
The range of remote control is limited when wires or optical fibers are used.
It is impractical to have a cable longer than a few kilometers. A special
problem exists for long-distance undersea remote control. Radio waves
at conventional radio frequencies cannot penetrate the oceans, but
extremely long cables present mechanical problems.
When the control station and the robot are very far away from each
other, even radio, IR, or visible-light signals take a long time to cover the
distance. A remotely controlled robot on the moon is about 1.3 light-
seconds away. It is 2.6 s from the time a command is sent to a robot on
the moon until the operator sees the results of the command.

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