Optical and Sensory
Often we mount cameras or other types of sensors on
robots for many different reasons, some of which are:
-
So a robot doesn't run into a wall or fall off a
platform
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To gather temperature or other information about the
environment
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To see what the robot sees in hazardous situations
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To see what another planet looks like
To survey the bottom of the ocean
The main types of sensors used in robots are range
finding, proximity,
imaging, contact,
communications, and Misc.
Range
The most common type of ranging sensor used is RADAR.
This acts just like "normal" radar, where radio waves are sent forward,
and the reflected waves are measured for signal strength and direction.
This information is used to determine how far an object is away.
RADAR is often used in the snow, rain, or other bad conditions where
visibility is limited. SONAR is another range finding device, which uses
sound waves instead of radio waves.
Source: www.de220.com
Proximity
Proximity sensors are used to either detect where an
object is, or detect where there are no objects. These are for
close range only, as opposed to Radar, which is used for long range.
For instance, a proximity sensor could be mounted below the front of a
robot (looking forward and down) and be assigned to detect where the
edge of a table is. When it reads nothing in front of it (the
table edge is near) it would send a false (0) signal to the processor.
The processor would then decide what it should do, based on the
programmed code for that condition. In this case, it would stop
and turn around.
Imaging
The main forms of robotic imaging are still cameras,
video cameras, Infrared cameras, and Omni Cameras (camera with mirror
for great viewing radius). With still and video cameras, the
footage captured cannot be used by the robot in most cases, and is just
taken for the operator to use. With IR (infrared) cameras however,
the footage taken can be used to determine where is a heat source
(human, or fire), and the robot can proceed in the direction.
Source: www.x20.org
Contact
The next type of sensor is used mainly to tell the
robot when it has come in contact with a wall or other obstacle. A
button can also be a contact sensor; when the robot hits another
object the button would be depressed, and the function activated.
Communications
Most communication sensors would be used to send
signals to other robots, and would technically not be considered
"sensors", since they don't sense anything. Communications sensors
usually send signals by means of Infrared signaling, or other types of
lights. They could also use a small speaker to send an audio cue.
Misc. Sensors
Other common types of sensors are used to detect
atmospheric conditions. Sensors could be used to measure the
temperature, humidity, time of day (based on light/dark), any gaseous
substances, radiation, and resistance of an object. |
