Vehicle Equipment Installation Instructions
8
3 Description
This section provides a general description of the
Opticom GPS system and a detailed description of the
vehicle equipment.
3.1 Opticom™ GPS System
The Opticom GPS system assists authorized
priority vehicles through signalized intersections by
providing temporary right-of-way through the use
of common traffic controller functions.
The Opticom GPS system consists of the following
matched components:
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Vehicle Equipment
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Radio/GPS unit containing a GPS receiver and a
2.4 GHz transceiver
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Radio/GPS antenna
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Control unit
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Intersection Equipment
—
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Radio/GPS unit containing a GPS receiver with
antenna and a 2.4 GHz transceiver with antenna
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Phase Selector
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Card Rack/Input File
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Auxiliary Interface Panel
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Auxiliary Harness
The vehicle equipment is mounted on the priority
vehicle. Its GPS receiver acquires position information
from the constellation of GPS satellites. This
information is used to compute the location, speed, and
heading of the vehicle. This information, along with a
priority request and the state of the vehicle’s turn signal,
is broadcast using the 2.4 GHz transceiver.
The intersection equipment receives the radio
transmission from the vehicle equipment. The
intersection equipment then compares the
information being received from the vehicle to the
parameters stored in the intersection equipment’s
memory. If the vehicle is heading toward the
intersection in a predefined approach corridor, is
requesting preemption and has met all other
programmed parameters, the corresponding phase
selector output is activated. This output is
connected to the traffic controller preemption input.
When activated, the controller cycles to grant a
green light to the requesting vehicle or holds the
green allowing the vehicle to pass through the
intersection.
The card rack/input file provides the power and logic
wiring for the phase selector, which plugs directly into
a slot in the unit.
The auxiliary interface panel provides additional
connection for monitoring green phases and also
provides additional priority control outputs.
The auxiliary harness can be used to provide
additional connection for monitoring green phases
when the auxiliary interface panel is not required.
