US 11,790,784 B2
Proximity detection system and method and collision avoidance system and method using proximity detection
Larry D. Frederick, Huntsville, AL (US); and Paul L. Hammond, Huntsville, AL (US)
Assigned to Strata Safety Products, LLC, Sandy Springs, GA (US)
Filed by Strata Safety Products, LLC, Sandy Springs, GA (US)
Filed on Jun. 21, 2022, as Appl. No. 17/845,527.
Application 17/845,527 is a continuation of application No. 16/993,806, filed on Aug. 14, 2020, granted, now 11,380,205.
Application 16/993,806 is a continuation of application No. 16/595,869, filed on Oct. 8, 2019, granted, now 10,769,955.
Application 16/595,869 is a continuation of application No. 16/233,690, filed on Dec. 27, 2018, granted, now 10,467,902.
Application 16/233,690 is a continuation of application No. 15/878,707, filed on Jan. 24, 2018, granted, now 10,170,000.
Application 15/878,707 is a continuation of application No. 15/288,507, filed on Oct. 7, 2016, granted, now 9,898,930.
Application 15/288,507 is a continuation of application No. 14/479,172, filed on Sep. 5, 2014, granted, now 9,466,216.
Application 14/479,172 is a continuation of application No. 13/538,156, filed on Jun. 29, 2012, granted, now 8,847,780.
Application 13/538,156 is a continuation of application No. 11/984,824, filed on Nov. 21, 2007, granted, now 8,232,888.
Claims priority of provisional application 60/996,034, filed on Oct. 25, 2007.
Prior Publication US 2022/0319331 A1, Oct. 6, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. G08G 1/16 (2006.01); B60Q 9/00 (2006.01); F16P 3/14 (2006.01); G08B 3/10 (2006.01); G08B 21/02 (2006.01)
CPC G08G 1/166 (2013.01) [B60Q 9/008 (2013.01); F16P 3/14 (2013.01); F16P 3/145 (2013.01); F16P 3/147 (2013.01); G08B 3/10 (2013.01); G08B 21/0213 (2013.01); G08B 21/0275 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of proximity detection, comprising:
generating a first magnetic field and second magnetic field;
determining a strength of the first and the second magnetic fields, respectively;
generating an alarm if the strength of the first magnetic field is above a first predetermined threshold and the strength of the second magnetic field is not above a second predetermined threshold.