Page 87 - Concise Encyclopedia of Robotics

Digital Signal Processing (DSP)
the horizontal and vertical dimensions.In a computer display,for example,
a common resolution is 1024 768 (1024 pixels horizontal and 768
pixels vertical).
In a visible digital image, color is usually rendered in as true-to-life a
fashion as possible.However,at IR and UV wavelengths,and especially with
radar and sonar, false colors are often used in digital images. For example,
in a sonar image, color can represent the range, or the distance between a
robot and objects in its work environment. Red might represent the
smallest range, progressing up through orange, yellow, green, blue, violet,
and finally white, representing the greatest (or infinite) range.
See also RESOLUTION.
DIGITAL INTEGRATED CIRCUIT
See INTEGRATED CIRCUIT.
DIGITAL LOGIC
See LOGIC GATE.
DIGITAL MOTION
In robotics, digital motion refers to the movement of a robot arm that can
stop only at certain positions within its work envelope. This is in contrast
to analogical motion, in which the number of possible positions is theo-
retically infinite.
The possible positions in a system that incorporates digital motion
must be programmed into the robot controller. For example, the base of
a robot arm might rotate to any multiple of 30° in the complete circle of
0° to 360°.This allows for 12 unique base-rotation angles.If more precision
is required,the angle increment can be reduced (10° will allow for 36 unique
base-rotation angles, for example).When the robot arm must be rotated to
a certain base angle position, the desired angle or step is entered into the
robot controller. The arm then moves to the designated position and stops.
Stepper motors are commonly used in robotic digital-motion systems.
These motors move in discrete increments, rather than rotating continu-
ously. Compare ANALOGICAL MOTION.
See also STEPPER MOTOR.
DIGITAL SIGNAL PROCESSING (DSP)
Digital signal processing (DSP) is a scheme for improving the precision of
digital data. It can be used to clarify or enhance signals of all kinds.

Analog cleanup
When DSP is used in an analog communications system, the signal is first
changed into digital form by A/D conversion. Then the digital signal is

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