Page 280 - Concise Encyclopedia of Robotics

Repulsive Radial Field
One of the most dramatic examples of radio remote control is the
trasmission of commands to space probes as they fly through the solar sys-
tem. In these cases, the separation distance is of the order of millions of
kilometers. As the probe Voyager passed Neptune, and a command was
sent to the probe, the results were not observed for hours. Remote control
of this type is a special challenge.
There is an absolute limit to the practical distance that can exist be-
tween a remotely controlled robot and its operator. There is (as yet) no
known way to transmit data faster than the speed of electromagnetic
(EM) energy in free space. Related definitions include AUTONOMOUS ROBOT,
FLIGHT TELEROBOTIC SERVICER, FLYING EYEBALL, GUIDANCE SYSTEM, INSECT ROBOT, LASER DATA
TRANSMISSION, MICROWAVE DATA TRANSMISSION, REMOTELY OPERATED VEHICLE, REMOTE
MANIPULATOR, ROBOTIC SPACE TRAVEL, SECURITY ROBOT, SELSYN, SYNCHRO, TELEOPERATION,
and TELEPRESENCE.
REPULSIVE RADIAL FIELD
See POTENTIAL FIELD.
RESOLUTION
Resolution is the ability of a robotic vision system to distinguish between
things that are close together. Within objects, resolution is the extent to
which the system can bring out details about the object. It is a precise
measure of image quality. It is sometimes called definition.
In a robotic vision system,the resolution is the “sharpness”of the image.
Poor resolution can be the result of poor focus, too few pixels in the
image,or a signal bandwidth that is not wide enough.The illustration shows
two objects that are far away and close together, as they might appear to
a robot vision system having four different levels of resolution.
When an analog image is converted into digital form, the sampling reso-
lution is the number of different digital levels that are possible.This number
is generally some power of 2.An analog signal has infinitely many different
levels; it can vary over a continuous range. The higher the sampling resolu-
tion, the more accurate is the digital representation of the signal.
In position sensing, and also in range sensing and plotting, the terms
direction resolution and distance resolution refer to the ability of a robot
sensor to differentiate between two objects that are separated by a small
angle,or that are almost the same distance away.The term spatial resolution
refers to the smallest linear displacement over which a robot can define
its work environment and correct errors in its motion.
See also DIRECTION RESOLUTION, DISTANCE RESOLUTION, PIXEL, SPATIAL RESOLUTION, and
VISION SYSTEM.

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