This proximity detection system was designed to train pedestrians and small vehicle drivers to stay a safe distance away from large trucks (Haultrucks). This system has been tested on a variety of Haultrucks including 50 ton, 240 ton and a 320 ton Haultruck at the Phelps Dodge mine in Morenci, Arizona USA, in May, 2000. This system was also tested at NIOSH (US Government – National Institute for Occupational Safety and Health) in May, 1999 and May 2000. The results were no misses and no false alarms, a perfect record. A Haultruck requires the installation of two MF4 Antennas, one at the front of the truck near the guard rail and the other underneath the rear of the truck to function correctly. This system is extremely flexible and can be used for many other applications and vehicles such as: Fork-Lifts, Bobcats etc.
One Buddy MF4 Antenna is mounted at the front of the truck close to the front railing and a second MF4 at the rear. Each MF4 radiates a magnetic field around the truck. There is no place around, behind or underneath the truck that this field does not penetrate and this has been tested on three different sized trucks with a capacity of from 50 tons, 240 tons and 320 tons.
The Proximity Detection Device (PDD) carried by the pedestrian measures the strength of the front and rear magnetic fields and transmits both values to the Proximity-Box on the Haultruck. The Proximity-Box compares these values with the two ‘Warning’ values stored in it’s memory.
If either the front or rear magnetic field strength value is greater than the ‘Warning’ values stored in memory then the PDD (pedestrian) is too close to the Haultruck and an alarm will be generated inside the cab for the driver and the air horn will be activated to warn the pedestrian.
The Haultruck Buddy System will detect a person who is wearing a PDD when he is anywhere around or underneath the Haultruck. It will even detect him if he is sitting inside a small vehicle which is close to the Haultruck and therefore in this situation the Buddy system will detect both the person and the small vehicle.