Page 189 - Concise Encyclopedia of Robotics

LADAR L
Ladar is an acronym that stands for laser detection and ranging. It is also
known as laser radar or lidar (short for light detection and ranging).
In robotics, a ladar system uses a shaft of visible light or infrared (IR)
energy,rather than radio waves (as in radar) or acoustic waves (as in sonar)
to perform range sensing and plotting of the environment. The device
works by measuring the time it takes for a laser beam to travel to a target
point,reflect from it,and then propagate back to the point of transmission.
The principal asset of ladar over other ranging methods is the fact that
the laser beam is extremely narrow. This provides vastly superior direction
resolution compared with radar and sonar schemes, whose beams cannot
be focused with such precision.
Ladar has limitations. It cannot work well through fog, or precipitation,
as can radar. Certain types of objects, such as mirrors oriented at a slant,
do not return ladar energy and produce no echoes.
A high-level ladar system scans both horizontally and vertically, thereby
creating a three-dimensional (3-D) computer map of the environment.This
type of system is extremely expensive. Less sophisticated ladar devices
work in a single plane, usually horizontal, to create a two-dimensional
(2-D) computer map of the environment at a specific level above a floor
or flat ground. Compare RADAR and SONAR.
See also COMPUTER MAP, DIRECTION RESOLUTION, and RANGE SENSING AND PLOTTING.
LADLE GRIPPER
A ladle gripper is a robotic end effector that can be used to move liquids. It
can also be used to move powders and gravel. The device gets its name
from its scooplike physical shape, and the manner in which it operates.
The end effector can be shaped like a half-sphere, a box, or any other
container that can hold liquids. Ladle grippers are used in industry to

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