Gate system for inventory control and theft prevention

Abstract

The present disclosure relates to a gate system which uses overlapping radiation patterns to deduce when an item is entering a warehouse and when an item is leaving a warehouse, for example, for loading onto a truck. The present disclosure stores information relating to the direction the item moved and actuates an alarm if the item is moved in an unexpected direction. The radiation patterns of the gates are angled such that one radiation pattern from a first antenna is directed towards the loading dock, while another radiation pattern from a second antenna is directed towards the interior of the building. Overlapping the radiation patterns allows the logic circuitry to account for the item as it moves from one side of the gate system to the other.

1 . A method of tracking inventory, the method comprising the steps of:
 providing a first antenna proximate an opening of a structure;   providing a second antenna proximate the opening;   emanating a signal from an item;   moving the item past the first antenna and measuring a first signal strength of the signal as the item moves past the first antenna;   determining a first time when the first signal strength peaks;   moving the item past the second antenna and measuring a second signal strength of the signal as the item moves past the second antenna;   determining a second time when the second signal strength peaks; and   comparing the first time and the second time to determine an actual direction the item moved past the first antenna and second antenna, wherein if the first time is before the second time then the actual direction of the item is entering the structure through the opening, and wherein if the first time is after the second time then the actual direction of the item is exiting the structure through the opening; and   providing the actual direction to an inventory tracking system.   
     
     
         2 . The method of  claim 1 , further comprising the step of:
 establishing an expected direction of the item;   comparing the expected direction with the actual direction of the item;   if the expected direction does not match the actual direction, then sounding an alarm after the actual direction is provided to the inventory tracking system, wherein the alarm is sounded during one of the following (i) as the item enters the building through the opening, and (ii) as the item exits the building through the opening and is loaded onto a truck at a loading bay.   
     
     
         3 . The method of  claim 1 , further comprising the steps of:
 associating the item with a record in a database of the inventory tracking system; and   associating the actual direction of the item entering or exiting the structure through the opening with the record.   
     
     
         4 . The method of  claim 3 , further comprising the steps of:
 associating the first time with the record; and   associating the second time with the record.   
     
     
         5 . The method of  claim 4 , further comprising the steps of:
 associating an expected direction with the record;   comparing the expected direction with the actual direction; and   sounding an alarm when the expected direction is different from the actual direction.   
     
     
         6 . The method of  claim 1 , wherein the first antenna and the second antenna are positioned near bumpers, wherein bumpers are configured to protect the first and second antennas from objects entering and exiting the structure through the opening. 
     
     
         7 . The method of  claim 1 , wherein the first antenna is positioned behind a first shield and the second antenna is positioned behind second shield, wherein the first and second shields facilitate the passing of electromagnetic signals therethrough. 
     
     
         1 . The method of  claim 1 , further comprising the steps of:
 overlapping a first radiation pattern of the first antenna with a second radiation pattern of the second antenna;   directing the first radiation pattern towards the opening; and   directing the second radiation pattern away from the opening.   
     
     
         9 . The method of  claim 1 , further comprising the steps of:
 defining the opening by a wall of the structure;   defining an imaginary plane parallel to the wall;   defining an imaginary opening line orthogonal to the imaginary plane;   defining a first imaginary line extending longitudinally through the first antenna;   orienting the first antenna such that the first imaginary line is between a 25 and 35 degree angle from the imaginary opening line.   
     
     
         10 . The method of  claim 9 , further comprising the steps of:
 defining a second imaginary line extending longitudinally through the second antenna;   orienting the second antenna such that the second imaginary line is between a 15 and 25 degree angle from the imaginary opening line.   
     
     
         11 . A method of tracking inventory, the method comprising the steps of:
 positioning both a first antenna and a second antenna near an opening formed in a wall of a building structure;   overlapping a first radiation pattern of the first antenna with a second radiation pattern of the second antenna;   determining a first time when an item moves through the first radiation pattern and storing the first time;   determining a second time when the item moves through the second radiation pattern and storing the second time; and   determining the direction the item is traveling by comparing the first time and the second time, wherein if the first time is before the second time then the item is entering the structure through the opening, and wherein if the first time is after the second time then item is exiting the structure through the opening.   
     
     
         12 . The method of  claim 11 , further comprising the steps of:
 expecting the item to be traveling in an expected direction;   determining whether the direction the item is traveling is the expected direction; and   actuating an alarm system if the direction the item is traveling is not the expected direction.   
     
     
         13 . The method of  claim 12 , further comprising the steps of:
 storing a variable representing the expected direction in a database system; and   determining whether the direction the item is traveling is the expected direction by comparing the direction with the variable in the database.   
     
     
         14 . The method of  claim 13 , further comprising the steps of:
 disposing the first antenna and the second antenna inside the building structure, wherein the wall is an exterior wall such that the building defines a building interior and a building exterior;   directing the first radiation pattern towards the building interior, and orienting the first antenna at an angle in a range from 25 and 35 degrees relative to the wall; and   directing the second radiation pattern towards the building exterior.   
     
     
         15 . The method of  claim 14 , further comprising the steps of:
 emitting a signal from the item;   sensing the signal by the first antenna to determine when the item moves through the first radiation pattern; and   sensing the signal by the second antenna to determine when the item moves through the second radiation pattern.   
     
     
         16 . The method of  claim 15 , further comprising the steps of:
 measuring repeatedly by the first antenna the power present in the signal as the item moves through the first radiation pattern;   setting the first time equal to when the first antenna determines the power present in the signal is the greatest as the item moves through the first radiation pattern;   measuring repeatedly by the second antenna the power present in the signal as the item moves through the second radiation pattern; and   setting the second time equal to when the second antenna determines the power present in the signal is the greatest as the item moves through the second radiation pattern.   
     
     
         17 . An apparatus adapted to track an item of inventory, the apparatus comprising:
 a first antenna having a first radiation pattern, wherein the antenna is configured to sense when the item moves through the first radiation pattern and store a first time associated with a peak power of the item in the first radiation pattern;   a second antenna having a second radiation pattern, wherein the antenna is configured to sense when the item moves through the second radiation pattern and store a second time associated with a peak power of the item in the second radiation pattern;   a server in communication with the first antenna and the second antenna, wherein the server determines an actual direction the item passes by the first antenna and the second antenna, wherein if the first time is before the second time then the actual direction of the item is entering a building structure through an opening, and wherein if the first time is after the second time then the actual direction of the item is exiting the structure through the opening;   a database in communication with the server, the database comprising an record containing an expected direction for the item to pass by the first antenna and the second antenna; and   an alarm system in communication with the server, wherein the server actuates the alarm system when the server determines the actual direction of the item does not match the expected direction.   
     
     
         18 . The apparatus of  claim 17 , further comprising:
 a signal generated by the item;   a first power sensor module disposed in the first antenna and configured to determine a first time when the power present in the signal is the greatest as the item moves through the first radiation pattern;   a second power sensor module disposed in the second antenna and configured to determine a second time when the power present in the signal is the greatest as the item moves through the second radiation pattern;   wherein the first antenna communicates the first time to the server;   wherein the second antenna communicates the second time to the server; and   wherein the server compares the first time and the second time to determine the actual direction.   
     
     
         19 . The apparatus of  claim 17 , wherein the apparatus is implemented in the building structure comprising an exterior wall forming the opening, the wall defining a building exterior and a building interior; and
 the first antenna is positioned within the building interior oriented at a 25 and 35 degree angle relative to the exterior wall.   
     
     
         20 . The apparatus of  claim 17 , further comprising:
 bumpers protecting the first and second antennas; and   non-metallic shields proximate the first and second antennas.