Transcript Using Infrared and Touch Sensors on the OCTARM VI Robot

Using Infrared and Touch Sensors
on the OCTARM VI Robot
Robert Clarke
Senior of Electrical Engineering and Physics
Clemson University
Introduction
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The OCTARM VI project, sponsored by
DARPA, falls under the branch of
robotics called Biodynotics.
The OCTARM VI Robot is a continuum
robot.
Numerous abilities and applications
Abilities of the OCTARM VI
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The arm can
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Rotate
Extend/Retract
Curl
The arm is like an elephant trunk.
Applications
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The OCTARM VI is being designed
mainly for military use.
Some possible applications are
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Search and Rescue
Explosive Ordnance/IED Removal
Space
How the Sensors Work
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Touch Sensors detect when the arm has
bumped into something.
IR Sensors are Proximity Devices. They
detect how far away the arm is from an
obstacle (such as a wall). The voltage output
of the sensor indicates proximity.
Each sensor is connected to a multiplexer,
which cycles through all signals, sending
them to the CPU.
Sensor Problems
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Touch Sensors and IR Sensors work by
themselves.
Large amount of noise is introduced in
the IR Sensor output when the two
types are combined.
Possible Solutions
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Rewire Touch Sensors so that they go
from an open to a closed state.
Redesign Touch Sensor circuit so that
one signal represents numerous
switches.
Solution #1
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Rewiring the touch sensors so that they
went from an open to a closed state
had no effect on the noise in the
sensors.
Solution #2
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Current Circuit Diagram:
IR Signal 1
IR Signal 6
+
W1
5V
IR
Sensor
...
IR
Sensor
...
R1
-
W6
R6
Touch Signal 1
Touch Signal 6
Solution #2
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Redesigned Touch Sensors:
R1
Signal
+
+
R2
W1
W1
Signal
5V
R1
5V
-
W2
R4
-
Old 1 switch to 1
signal style
R3
W3
New 3 switches to 1 signal style
Problems with Solution #2
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Theoretically, we have been unable to
find a resistor combination for R1, R2,
R3, and R4 that results in a voltage
threshold detectable over noise.
Experimentally, we have been unable to
test this new switch design due to
failure of the arm’s mux board.
Where are We Going?
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First thing: Resolve the compatibility
issue between the IR and Touch
Sensors
Next: Write software and run
experiments with both sensors.
Finally: Publish Results
Any Questions?