User Configurable Detection Lanes
Lane Definition
A lane is a user-configurable range slot within the radar’s detection zone. When a vehicle
is present within this slot, the lane gets “activated”. Lane activations are used for
presence indication whereas vehicle tracking is used for counting. For example if a
vehicle has crossed from lane to lane it will be counted once only but both lanes will be
sequentially activated. If a lane is mapped to a hardware trigger output, the radar asserts
that trigger and keeps it asserted for as long as the vehicle remains in that lane. Multiple
lanes can be mapped to the same hardware trigger output. In this case the output will be
asserted for as long as there are vehicles in any of the mapped lanes.
Trigger Pulse Extension
Trigger output duration may be extended by programming an HT variable. HT variable
represents signal extension time in milliseconds. Typical uses are:
1.
Trigger pulse extension to support slow interfaces in user equipment where the
fast target that generates a very short presence pulse would otherwise be missed.
2.
Lighting actuation in security systems where it is desired to have an activation
duration that is much longer than the vehicle presence time.
Lane Status over RS232
Target presence information in each lane (lane activation status) is also available in real-
time to an attached controller via the serial port. An external controller communicates
with the radar via the Houston Radar Binary protocol. The same protocol is used to
communicate to all radars (Doppler and FMCW) produced by Houston Radar. Please
contact us for an SDK (software development kit) if you wish to utilize this feature.
Additional lane information such as counts, occupancy indicators and detection events is
available through
ASCII data streaming
and
stored data
.
Lane Setup
Typically, you would configure one or more detection lanes during initial setup. Please
note that the radar measures distance along the line of view from the radar to the target
and does not correct for the mounting height. This is usually not a problem as the
supplied configuration program accumulates and displays all detected targets as a
histogram in real time regardless of lane setup and the user may simply draws the lane
boundaries around the histogram peaks. Thus no manual calculations are required.
Once lanes are configured you may map one or more of them to a hardware output. When
the radar detects target presence within a configured lane(s), it will assert the associated
hardware output.
