Patent ID: 8847780
Filing Date: 2014-09-30
Classification: B60Q,F16P,G08B,G08G

Abstract:
1. A proximity detection system for complex work environments for detecting the presence of a worker or operator wearing an alarm device in a potentially hazardous location at a work site, the proximity detection system comprising: a plurality of vehicles; each of the vehicles having a plurality of magnetic field generators; each of the plurality of magnetic field generators adapted to generate ping pulses of a magnetic field; a plurality of alarm devices located on the persons of a plurality of workers and/or operators, each device being adapted to sense the ping pulse magnetic field in which the device is located and generate an echo response signal after a predetermined echo time delay; the plurality of magnetic field generators being adapted to receive the echo response signals, and in response to receiving the echo response signal during a window of time corresponding to the predetermined echo time delay, to generate a burst of the magnetic field ping pulses, the burst of ping pulses being of predetermined duration and being generated at semi-random time intervals; the plurality of magnetic field generators being adapted to, in response to receiving the echo response signal during a window of time corresponding to the predetermined echo time delay for each of the ping pulses of the burst, identify that the device is located in a particular magnetic field generated by one of the plurality of magnetic field generators.