User's Manual

Personal Node User Manual Section 4 Working with the Personal Node
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4.4.1 Zone tolerance
In the SafeDetect system, warning zones have a small tolerance to prevent the situation where an
alarm is repeatedly annunciating as a vehicle moves around in a small area of a zone boundary. The
tolerance of 5% is provided on the exit side of a warning zone so that, for example, if a warning zone
is set at 20 m, the vehicle can move 21 meters away from the user and not trigger a new alarm when
moving back within the 20 m warning zone. The tolerance was designed to prevent unnecessary zone
transitions and is safe and practical.
4.5 About In-Vehicle Detection
If a user enters a vehicle as a Vehicle Operator or passenger, the Personal Node is put into In-Vehicle
Detection (IVD) mode to suppress the proximity alarm on both the Personal Node and the In-Vehicle
PC. The IVD function uses two small zones within which the Personal Node audible alarm can be
suppressed for the whole time the user is within that zone. The user is now within the vehicle’s
warning zones and uses the In-Vehicle PC to detect and view approaching potential hazards.
To reduce the number of unwanted automatic IVD cancellations (eg the user is moving in or around a
large vehicle), the IVD function effectively uses inner and outer zones that:
• Activates on entry to the inner zone.
• Deactivates 5 s after exit from the outer zone.
4.5.1 IVD Principle
IVD relies on the principle that users are not only responsible for their own safety but also have a
responsibility to Vehicle Operators that ensures they see the correct information on their In-Vehicle
PC.
Table 7 IVD examples below shows correct ( ), incorrect ( ) and doubtful ( ) results if not using
IVD correctly. At all stages below, vehicles will be able to see each other as they use Mobile Nodes.
Table 7 IVD examples
Scenario
After entering a haul truck
After exiting a haul truck
Three people in a
haul truck using IVD
mode as designed.
•
•
Vehicle Operators cannot 'see' any
pedestrians.
The users' Personal Nodes will not
annunciate an alarm when
approaching another vehicle.
•
•
Vehicle Operators 'see' three
users as a potential hazard.
The users' Personal Nodes will
annunciate an alarm when
approaching another vehicle.
Refer to the
SafeDetect Operator Manual
for details on the In-Vehicle PC.
The IVD range is configurable by the System Administrator.