User's Manual

Personal Node User Manual Section 13 Appendices
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Commonwealth Scientific and Industrial Research Organisation; Australian federal government scientific research agency.
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Power Distribution and Protection Unit, usually only required for heavy vehicle installations.
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Trax is a tracking /positioning system that uses all hardware required by the two other systems.
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SafeDetect is a peer-to-peer proximity detection system and does not use an infrastructure.
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SMARTS is a productivity and scheduling solution and does not use Personal or Mobile Nodes.
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Mobile and Personal
Nodes do not use standard 2.4Ghz Wi-Fi.
13.2 Zone sizes
Your site has already determined and set the zone sizes. The correct zone sizes should be reflected in
your standard operating procedures.
SafeDetect is a passive system that advises the users of potential hazards and does not actively
control equipment or provide emergency stops. It is worth noting, for example, that even though a
Vehicle Operator may be aware of you and other users on their In-Vehicle PC, the stopping distance
for a vehicle approaching you is the sum of the distances travelled during the following time delays:
1) System delay – The system has a small 'signal processing delay'. The system delay is typically
no more than about a second. During this time a vehicle will travel a distance before the driver
sees or hears any alarm.
2) Driver reaction time – This is the distance travelled between the driver seeing the stop alarm
and then applying the brakes. Reaction times vary with age and fatigue and may be a short as
200 ms or as much as about 1.5 seconds.
3) Braking delay – distance travelled after the driver applies the brakes; the braking distance
varies on vehicle type, speed and the road surface conditions (wet, dry, sealed, unsealed,
slope, camber etc.).
Table 19 Vehicle speed examples below shows the distances travelled by a vehicle in one second.
Two vehicles travelling towards each other will close the distance at twice these rates. Considering all
the factors mentioned above, the stopping distance may be significant, and zones are sized
accordingly.
Table 19 Vehicle speed examples
Vehicle Speed (km/h)
Distance travelled in 1 s
50
13.9 m
40
11.1 m
36
10.0 m
30
8.3 m
20
5.5 m
10
2.8 m
Irrespective of the zone sizes configured at your site, common road sense applies.