Interactive magnetic marker field for safety systems and complex proximity warning system
First Claim
1. A proximity detection system, comprising:
- a generator that generates a magnetic field, said generator being capable of receiving response signals; and
an alarm device that sends response signals, the alarm device being capable of sensing said magnetic field and generating a response signal;
wherein said generator generates said magnetic field for a first predefined time period, and senses for a response signal from said alarm device within a second predefined time period;
wherein said alarm device generates a response signal of a first length of time when the alarm device detects the magnetic field at a first strength,wherein said alarm device generates a response signal of a second length of time when the alarm device detects the magnetic field at a second strength, andwherein the first strength is different from the second strength and the first length of time is different from the second length of time.
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Accused Products
Abstract
The invention relates to a proximity detection system. The invention provides a proximity detection system comprising a generator that generates a magnetic field that establishes a boundary, where the generator is capable of receiving radio frequency signals. Also provided is a radio frequency device that sends radio frequency signals, the radio frequency device being capable of sensing the magnetic field and generating a radio frequency response. In the proximity detection system, the generator generates the magnetic field for a first predefined time period, and thereafter senses for a radio frequency response signal from the radio frequency device within a second predefined time period. The invention also provides for shaping proximity detection zones by overlaying magnetic field boundaries to produce a different boundary. The invention also provides for varying the strength of magnetic fields by adjusting a width of a timed pulse.
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Citations
41 Claims
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1. A proximity detection system, comprising:
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a generator that generates a magnetic field, said generator being capable of receiving response signals; and an alarm device that sends response signals, the alarm device being capable of sensing said magnetic field and generating a response signal; wherein said generator generates said magnetic field for a first predefined time period, and senses for a response signal from said alarm device within a second predefined time period; wherein said alarm device generates a response signal of a first length of time when the alarm device detects the magnetic field at a first strength, wherein said alarm device generates a response signal of a second length of time when the alarm device detects the magnetic field at a second strength, and wherein the first strength is different from the second strength and the first length of time is different from the second length of time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 15, 16, 17, 18, 19, 20, 21, 22)
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10. A proximity detection system for generating a shaped proximity detection boundary, comprising:
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a first generator that generates a first magnetic field having a first boundary; a second generator that generates a second magnetic field having a second boundary, wherein overlaying said first and second boundaries produces a different boundary, and wherein said first and second magnetic fields are generated in sequence; and an alarm device capable of sensing said first magnetic field and said second magnetic field; wherein said alarm device issues an alarm when it senses the first magnetic field and not the second magnetic field, and wherein the alarm device does not issue an alarm when it senses the first magnetic field and the second magnetic field. - View Dependent Claims (11, 12, 13, 14)
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23. A proximity detection system, comprising:
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a generator that generates a magnetic field, said generator being capable of receiving a response signal from a personal alarm device; and a personal alarm device that responds to sensing said magnetic field by generating and sending a response signal to the generator; wherein said personal alarm device generates a response signal after a first length of time when the personal alarm device detects the magnetic field at a first strength, wherein said personal alarm device generates a response signal after a second length of time when the personal alarm device detects the magnetic field at a second strength, and wherein the first strength is different from the second strength and the first length of time is different from the second length of time. - View Dependent Claims (24, 25, 26)
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27. A proximity detection system, comprising:
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a first magnetic field generator that generates a first magnetic field as a series of pulses, and a personal alarm device that detects the series of pulses of the first magnetic field and generates a series of response signals in response to the series of pulses, wherein the series of timed pulses of the first magnetic field are semi-randomly spaced apart and wherein the series of response signals generated by the personal alarm device have substantially the same timing as the series of pulses of the first magnetic field. - View Dependent Claims (28, 29, 30, 31, 32)
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33. 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:
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a plurality of vehicles; each of the vehicles having at least a first, second, and third magnetic field generator; each of the first, second, and third magnetic field generators adapted to generate ping pulses of a first, second, and third magnetic field, respectively, the first, second, and third magnetic fields having an overlapping area and oscillating at low frequency during each ping pulse, the ping pulses having predetermined pulse durations and being generated at first semi-random time intervals; a plurality of alarm devices located on the persons of a plurality of workers and/or operators, each device being adapted to sense the strength of the ping pulse magnetic field in which the device is located and to generate an echo response signal after a predetermined echo time delay, wherein the length of the predetermined echo time delay or the length of the echo response signal is based on the sensed strength of the ping pulse magnetic field; the first, second, and third 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 second semi-random time intervals, the second semi-random time intervals being shorter than the first semi-random time intervals; the first, second, and third 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 the first, second, and/or third magnetic field, and to, based on the length of the predetermined echo time delay or the length of the echo response signal, identify that the device is located in a particular one of a plurality of zones of the first, second, and/or third magnetic field, each zone being smaller than the magnetic field; wherein each of said plurality of alarm devices issues a first type of alarm when it senses a first zone of the first or second magnetic field and wherein each of said plurality of alarm devices issues a second type of alarm when it senses the first zone of both the first and second magnetic fields; and wherein each of said plurality of alarm devices issues an alarm when it senses at least one of the first and second magnetic fields and not the third magnetic field, and wherein each of said plurality of alarm devices does not issue an alarm when it senses the third magnetic field only or in addition to the at least one of the first and second magnetic fields. - View Dependent Claims (34, 35)
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36. 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:
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a plurality of vehicles; each of the vehicles having at least one magnetic field generator; each of the at least one magnetic field generators adapted to generate ping pulses of a magnetic field, the magnetic field oscillating at low frequency during each ping pulse; a plurality of alarm devices located on the persons of a plurality of workers and/or operators, each device being adapted to sense the strength of the ping pulse magnetic field in which the device is located and to generate an echo response signal after a predetermined echo time delay, wherein the length of the predetermined echo time delay is based on the sensed strength of the ping pulse magnetic field; the at least one magnetic field generator being adapted to identify that the device is located in a particular one of a plurality of zones of the magnetic field, each zone being smaller than the magnetic field based on the length of the predetermined echo time delay.
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37. 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:
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a plurality of vehicles; each of the vehicles having at least one magnetic field generator; each of the at least one magnetic field generators adapted to generate ping pulses of a magnetic field, the magnetic field oscillating at low frequency during each ping pulse; a plurality of alarm devices located on the persons of a plurality of workers and/or operators, each device being adapted to sense the strength of the ping pulse magnetic field in which the device is located and to generate an echo response signal after a predetermined echo time delay, wherein the length of the echo response signal is based on the sensed strength of the ping pulse magnetic field, the at least one magnetic field generator being adapted to identify that the device is located in a particular one of a plurality of zones of the magnetic field, each zone being smaller than the magnetic field based on the length of the echo response signal.
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38. 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:
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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, the magnetic field oscillating at low frequency during each ping pulse, the ping pulses having predetermined pulse durations and being generated at first semi-random time intervals; 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 second semi-random time intervals, the second semi-random time intervals being shorter than the first 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.
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39. 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:
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a plurality of vehicles; each of the vehicles having at least a first and second magnetic field generator; each of the first and second magnetic field generators adapted to generate ping pulses of a first and second magnetic field, respectively, the first and second magnetic fields having an overlapping area and oscillating at low frequency during each ping pulse; 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 to generate an echo response signal; wherein each of said plurality of alarm devices issues a first type of alarm when it senses the first or second magnetic field and wherein each of said plurality of alarm devices issues a second type of alarm when it senses both the first and second magnetic fields. - View Dependent Claims (40)
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41. 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:
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a plurality of vehicles; each of the vehicles having at least a first and second magnetic field generator; each of the first and second magnetic field generators adapted to generate ping pulses of a first and second magnetic field, respectively, the first and second magnetic fields having an overlapping area and oscillating at low frequency during each ping pulse; 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 to generate an echo response signal; wherein each of said plurality of alarm devices issues an alarm when it senses the first magnetic field and not the second magnetic field, and wherein each of said plurality of alarm devices does not issue an alarm when it senses the second magnetic field and the first magnetic field.
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Specification