Proximity detection system and method and collision avoidance system and method using proximity detection

• US 9,466,216 B2
• Filed: 09/05/2014
• Issued: 10/11/2016
• Est. Priority Date: 10/25/2007
• Status: Active Grant

• Current Assignee: Strata Safety Products LLC (Strata Worldwide Holdings, Inc.)
• Original Assignee: Strata Safety Products LLC (Strata Worldwide Holdings, Inc.)
• Inventors: Frederick, Larry D., Hammond, Paul
• Primary Examiner(s): Yacob, Sisay
• Application Number:
  US14/479,172
• Publication Number:
  US 20140375445A1
• Time in Patent Office: 767 Days
• Field of Search: 340/686.1, 340/686.6, 340/500, 34053921-53923, 340/540, 340/551, 340/573.4, 340/870.01, 340/870.1, 3408703-87032, 324/207.121, 324/207.171, 324/228, 324/239, 324/243, 324/713, 119/712, 119/720, 119/721
• US Class Current: 1/1
• CPC Class Codes: B60Q 9/008 for anti-collision purposes
• CPC Class Codes: F16P 3/14 the means being photocells or other devices sensitive without mechanical contact
• CPC Class Codes: F16P 3/145 using magnetic technology
• CPC Class Codes: F16P 3/147 using electro-magnetic technology, e.g. tags or radar
• CPC Class Codes: G08B 21/0213 System disabling if a separation threshold is exceeded disabling electrical appliances in case of unplugging G08B13/1409
• CPC Class Codes: G08B 21/0275 Electronic Article Surveillance [EAS] tag technology used for parent or child unit, e.g. same transmission technology, magnetic tag, RF tag, RFID
• CPC Class Codes: G08B 3/10 using electric transmission; using electromagnetic transmission
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes

Abstract

The invention relates to a complex proximity safety and warning system. The invention provides a safety 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 safety 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 safety 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.

Claims

1. A system, comprising:

a vehicle;

a generator that generates a magnetic field, the generator being configured to receive response signals; and

an alarm device that sends response signals, the alarm device being configured to sense the magnetic field and generate a response signal;

wherein the generator generates said magnetic field for a first predefined time period, and senses for a response signal from the alarm device within a second predefined time period, wherein the second predetermined time period comprises a plurality of time portions;

wherein the alarm device generates a radio frequency response signal of a first length of time when the alarm device detects the magnetic field at a first strength,

wherein the alarm device generates a radio frequency 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 less than the second strength, the first length of time is shorter than the second length of time, and the radio frequency response signal of the first length of time appears in less than all of the plurality of the time portions and the radio frequency response signal of the second length of time appears in all of the plurality of time portions,

wherein the system is a collision avoidance system.

2. The collision avoidance system of claim 1, wherein the generator is positioned at the vehicle.

3. The collision avoidance system of claim 2, wherein the alarm device is positioned at a dump point.

4. The collision avoidance system of claim 2, wherein the alarm device is positioned at a loading dock.

5. The collision avoidance system of claim 2, wherein the vehicle is a first vehicle, and further comprising a second vehicle, the alarm device being positioned at the second vehicle.

6. The collision avoidance system of claim 5, wherein the generator is a first generator and the alarm device is a first alarm device, and further comprising:

a second generator similar to the first generator, and a second alarm device similar to the first alarm device;

the second generator being positioned at the second vehicle, and the second alarm device being positioned at the first vehicle.

7. The collision avoidance system of claim 6, further comprising:

a first circuit connecting the first generator and the second alarm device, wherein the circuit disables the second alarm device during the time the first generator generates the magnetic field.

8. The collision avoidance system of claim 6, wherein the second alarm device generates an alarm when it senses the magnetic field of the second generator.

9. The collision avoidance system of claim 1, further comprising:

a plurality of vehicles;

a plurality of generators, each similar to the generator;

a plurality of alarm devices, each similar to the alarm device;

each of said vehicles having a corresponding one of the generators and alarm devices.

10. The collision avoidance system of claim 1, wherein said generator senses for the response signals from said alarm device after a predetermined time delay.

11. The collision avoidances system of claim 1, wherein said generator is turned on and off to generate pulses of said magnetic field.

12. The collision avoidance system of claim 1, wherein said magnetic field operates at a low frequency of approximately 73 kHz.

13. The collision avoidance system of claim 1, further comprising multiple generators that generate oscillating magnetic fields in a random manner within selected periods of time.

14. The collision avoidance system of claim 1, wherein said alarm device is adapted to measure a strength of said magnetic field, and if the field strength exceeds a predetermined value, generates an alarm.

15. The collision avoidance system of claim 13, wherein said alarm device senses strengths of magnetic fields from said multiple generators and differentiates between said strengths to determine whether values have been exceeded and to produce an alarm that gives priority to the higher levels of said sensed strengths.

16. The collision avoidance system of claim 11, further comprising multiple generators, wherein said multiple generators generate oscillating magnetic fields sequentially and not at the same time.

17. The collision avoidance system of claim 1, wherein a size of the magnetic field is modified by changing a width of a waveform input to a tuned circuit of the generator.

18. The system of claim 1, wherein the generator is configured to send a signal to shut down the vehicle upon sensing a response signal of a predetermined strength.

19. The system of claim 1, wherein the radio frequency response signal of the first length of time indicates the alarm device is in a warning zone.

20. The system of claim 1, wherein the radio frequency response signal of the second length of time indicates the alarm device is in a danger zone.

21. A method, comprising the steps of:

generating by a magnetic field generator a magnetic field for a first predefined time period;

sensing by an alarm device the magnetic field and generating a radio frequency response signal, the radio frequency response signal being a first length of time when the alarm device detects the magnetic field at a first strength, and the radio frequency response signal being a second length of time when the alarm device detects the magnetic field at a second strength; and

sensing by the magnetic field generator for the radio frequency response signal within a second predefined time period, wherein the second predetermined time period comprises a plurality of time portions;

wherein the first strength is less than the second strength, the first length of time is shorter than the second length of time, and the radio frequency response signal of the first length of time appears in less than all of the plurality of the time portions and the radio frequency response signal of the second length of time appears in all of the plurality of time portions,

wherein the method is for avoiding collision.

22. The method of claim 21, further comprising the steps of:

providing a plurality of vehicles;

providing a plurality of generators, each located at a corresponding vehicle and each for generating a corresponding magnetic field;

providing a plurality of alarm devices, each located at a corresponding vehicle and each for sensing a magnetic field and generating a response.

23. The method of claim 22, further comprising the step of disabling the alarm device during the time the generator generates the magnetic field for a corresponding vehicle.

24. The method of claim 21, further comprising the step of sending a signal to shut down the vehicle upon sensing a response signal of a predetermined strength.