SmarTek Systems SAS-1 Intro and Background - Manual (Page 5)

SmarTek Systems (www.smarteksys.com) 5
example shown in Figure 3,
detection zone sizes and
placement were selected to
correspond to three active lanes
and two shoulders. In the TAI
display, each pair of Blue Lines
represents the left and right
edges of each detection zone.
The detection zones for this
example are chosen to leave
little or no dead space. That is,
where one zone ends, the next
one begins. For this
configuration, any lane switcher
will be detected and placed in
one zone (lane) or the other. In
the TAI display, the blue
detection zone indicator lines
mimic real highway lane divider
lines. The SAS Monitor and
Setup display also provides the
end user with SAS-1 detection
indicator marks (magenta)
which are placed in the center of
each detection zone. These
indicator marks provide the
installer with instant real time
feedback to show exactly how
well the SAS-1 is detecting
vehicles and what zone (or lane) the vehicle detections are assigned to. After setup is complete,
the SAS-1 will continue to operate in a default operating mode as selected by the installer.
Default Operating Modes
Multi-Lane Flow Mode - The SAS-1 computes and reports vehicle count, lane occupancy, and
average speed for each lane for a specified update period (i.e. 20 sec, 30 sec, 1 minute, etc.).
Each SAS-1 can be set to output these measurements every period or wait to be polled by a
cabinet controller.
Multi-Lane Single Zone or Dual Zone Relay Signal Mode - The SAS-1 outputs a stream of bit
serial relay signals for up to ten (10) relays (5 upstream relays and five down stream relays) for
multi-lane monitoring and vehicle presence indication. When used with the SAS Relay
Interface, the SAS-1 provides a multi-lane single or dual “magnetic loop” equivalent set of
sensor hardware that can plug into existing “loop detector” cabinets. The SAS-1 will not “tune
out” a vehicle that remains in the detection zone for a prolonged period of time.
SAS-1
91 Look
Directions
Time
Each “Blob” Shows Position
and Strength of a Vehicle’s
Acoustic Intensity
- Lt Green is Weak
- Dk Green/Red is Strong
Lane Switcher
Detection Indicator
(Magenta Markers)
Lane 1
Lane 2
Lane 3
LS R S
Traffic in Other
Direction
Figure 3 SAS-1 Acoustic “Image” Formation