|
Who
Uses AVL?
Transportation real-time fleet management. Emergency
vehicles: Law
enforcement, fire, and paramedic. Utilities: locating nearest available
vehicle to respond to a service. Long-haul truckers.
Delivery services: Courier, newspapers, and fast food
where prompt customer service is critical. 
Public
transportation: buses, vans. Commercial sanitation.
Towing and snowplows. Commercial carriers, TL and LTL.
Military and logistics. Forestry, oil and gas
exploration. |
|
|
 |
| |
 |
|
|
 |
|
Automatic
Vehicle Location (AVL) provides up-to-date location information for emergency vehicles, delivery trucks,
freight trucks, service vehicles etc. The AVL system
consists of a GPS receiver on the truck or vehicle, a communications link between the vehicle
and the dispatcher, and pc-based tracking software for
dispatch. The communication system is usually a
cellular network similar to the one used by your
cellular phone. The diagram above illustrates
the AVL system. It shows the GPS signal arriving
from a satellite to the truck (on the left). The
truck location is communicated to the PC dispatch
software (on the right). That's all there is in
a basic AVL setup. The equipment comes
prepackaged with simple installation instructions and
manuals. For those who want details, read the
section to follow. The
primary advantages to an AVL system are:
 | Locate and send nearest
vehicle to customer
|
Greater number of
pickups and deliveries per day
|
Increase on-time
deliveries
| Increase number of vehicles
dispatcher can manage
| Tracking report documentation |
| | | |
AVL Details
GPS provides the location of a
vehicle with accuracies of about 25-30 feet. The GPS
NavStar system was developed by the military for use
by nuclear submarines and field military units.
It is also used to guide missiles and artillery shells
with pinpoint accuracy. The system has
24-satellites which at least 4 communicate to the AVL
vehicle GPS receiver. The geographic location is
logged into the vehicles GPS units and transferred
with vehicle ID to dispatch along with time, speed,
and heading. User set updates can be every X
seconds or X minutes. For communications, Cloudberry
uses a robust "always connected" wireless
national data network. As an alternative
communications link, a satellite communication
network (not to be confused with the GPS
satellite system) is available for areas where
ground-based wireless communications is weak.
The communication satellite receives position
information from the AVL vehicle's satellite
transmitter (uplinks) and forwards it
(downlinks) to the tracking dispatch
station. The dispatch software street map layer
shows vehicle icons against specific local streets and
intersections. An added feature to the system is
two-way mobile messaging. It allows e-mail
messaging to and from the driver over the Internet
wireless communications link. Now Nextel
GPS embedded cellular are available as alternative
vehicle equipment. In addition, an
Executive Web Service allows access for authorized
managers, customers, owners, and shippers.
|
|
|
