RFID based inventory tracking system

Abstract

A method of tracking two or more objects in an inventory can include disposing respective RFID tags on respective ones of the two or more objects. The method can include, for each of the two or more objects, engaging a secondary antenna with the RFID tag disposed on the object when the object is in an inventory area, and disengaging the secondary antenna from the RFID tag disposed on the object when the object is removed from the inventory area. The secondary antenna can be configured to electromagnetically couple with a primary antenna in the RFID tag disposed on the object when the secondary antenna is engaged with the RFID tag disposed on the object, and the secondary antenna can be configured to increase an operating range of the RFID tag disposed on the object when the secondary antenna is engaged with the RFID tag disposed on the object.

Description

RFID BASED INVENTORY TRACKING SYSTEMCROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims priority to U.S. Prov. Pat. Appl. No. 63 / 549,094, filed February 2, 2024, which is incorporated herein by reference in its entirety.TECHNOLOGICAL FIELD

[0002] The present disclosure relates to electronics, and more particularly, but not by way of limitation, to an RFID based inventory tracking system, such as can be used to track an inventory of firearms.BACKGROUND

[0003] Inventory tracking systems can be used to track one or more objects in an inventory of objects. In a manual inventory tracking process, the status of one or more objects in the inventory may be recorded. For example, notes can be kept on whether a specific object is in the inventory or out of the inventory. Inventory tracking can be desirable to one or more of (1) determine which objects are in an inventory by reference to an inventory list as opposed to tallying objects or confirming the location of objects, (2) comply with reporting requirements or other regulations, or (3) track objects that can have human health implications.SUMMARY

[0004] A method of tracking two or more objects in an inventory can include disposing respective RFID tags on respective ones of the two or more objects. The method can also include, for each object of the two or more objects, engaging a secondary antenna with the RFID tag disposed on the object when the object is in an inventory area, and disengaging the secondary antenna from the RFID tag disposed on the object when the object is removed from the inventory area, where the secondary antenna can be configured to electromagnetically couple with a primary antenna in the RFID tag disposed on the object when the secondary antenna is engaged with the RFID tag disposed on the object, and where the secondary antenna can be configured to increase an operating range of the RFID tag disposed on the object when the secondary antenna is engaged with the RFID tag disposed on the object.

[0005] A radio frequency identification (RFID) system for tracking an inventory of firearms can include one or more RFID tags, which can be disposed on one or more firearmsrespectively. Each of the RFID tags can include a primary antenna, and an integrated circuit (IC) chip, coupled to the primary antenna. The RFID system can also include one or more secondary antennas, where each secondary antenna can be configured to electromagnetically couple with any of the one or more RFID tags and where each secondary antenna can be configured for temporary attachment to a firearm when the firearm is placed in storage and can be physically separable from the firearm when the firearm is removed from storage.

[0006] A radio frequency identification (RFID) system can include an RFID tag. The RFID tag can include a primary antenna, an integrated circuit (IC) chip, coupled to the primary antenna, and a first insulating substrate, where the primary antenna and the IC chip can be disposed on the first insulating substrate. The RFID system can also include a secondary antenna, which can include a second insulating substrate separate from the first insulating substrate and an aperture defined in the second insulating substrate, where a conductive portion of the secondary antenna is configured to at least partially surround the aperture, where the RFID tag is configured to engage with the primary antenna by at least partially inserting into the aperture, and where the secondary antenna can be configured to electromagnetically couple with the primary antenna when the RFID tag is at least partially inserted into the aperture.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In the drawings, which may not be drawn to scale, like numerals can describe substantially similar components throughout one or more of the views. Like numerals having different letter suffixes can represent different instances of substantially similar components. The drawings illustrate generally, by way of example but not by way of limitation.

[0008] FIG. l is a perspective drawing of an example of portions of a radio frequency identification (RFID) system.

[0009] FIG. 2 is a cutaway top view drawing of an example of portions of the RFID system of FIG. 1, where the secondary antenna has been removed.

[0010] FIG. 3 is a perspective drawing of an example of portions of the RFID system of FIG. 1, where the RFID tag has been removed.

[0011] FIG. 4 is a drawing of an example of portions of a RFID system disposed on a firearm.

[0012] FIG. 5 is a drawing of an example of portions of a RFID system disposed on a firearm.

[0013] FIG. 6 is a block drawing of an example of portions of a RFID system, including portions of an environment in which the RFID system can be used.

[0014] FIG. 7 is a diagram showing an example of a method for operating portions of an RFID system.DETAILED DESCRIPTION

[0015] Tracking an inventory of objects can be one or more of expensive, laborious, time consuming, or otherwise difficult, such as due to having to make note of each object as it leaves the inventory or enters the inventory, and having to collate multiple notes to determine the status of objects. For example, when an object is removed from the inventory, a note must be made that the object has been removed from the inventory. When the object is returned to the inventory, a note must be made that the object has been returned to the inventory. When the status of the object (e.g., in the inventory, out of the inventory) is desired, the recorded notes must be searched for the latest entry. For positive confirmation of the status of the object (e.g., confirming that the object is in the inventory), the object must be physically located to confirm the objects presence, or the entire inventory must be searched to confirm the object is not present.

[0016] It can be desirable to track objects in an inventory across a large range, for example, across an entire inventory room, such as using a long range RFID tag and RFID reader. However, for military and / or other personnel, having an RFID tracking device with a long range on a firearm and / or other object carried in the field could give away position data of the personnel, such as can be undesirable. Therefore, it can be desirable to have an RFID tracking system that can have a long range when an object is stored, but can have a more limited range when the object is in use.

[0017] The present inventor has recognized, among other things, that it can be beneficial to have an inventory monitoring system that operates without manual tracking and recording of object status. For example, a RFID based inventory system. The system can include one or more RFID tags disposed on one or more objects in the inventory. The system can also include an RFID reader configured to scan an inventory area and determine which RFID tags are in the area. In this way, the system can determine whether the objects are in the inventory or not, such as without manual tracking and recording. Furthermore, a greater degree of positive confirmation that an object is in the inventory tracking area can be determined without physically locating the object.

[0018] In general, in an approach, an RFID tag disposed on an object can be configured to have an operating range (e.g., a range at which the RFID tag can be read by the RFID reader), such as can include a range that spans the entire inventory area, or spans a portion thereof. Thepresent inventor has recognized, among other things, that it can be beneficial to decrease or otherwise alter a range of the RFID tag when the object is not in the inventory. This can one or more of increase a level of privacy of the user of the object including the RFID tag, decrease a detectability of the object including the RFID tag, or provide another benefit. In an example, a removable secondary antenna that increases a range of an RFID tag can be removed from the object when the object is removed from the inventory.

[0019] FIG. l is a perspective drawing of an example of portions of a radio frequency identification (RFID) system 100. FIG. 1 shows that the RFID system can include an RFID tag 110 and a secondary antenna 120. FIG. 1 also a shows an x-axis 151, a y-axis 152, and a z-axis 153. The secondary antenna 120 can be configured to extend or otherwise alter an operating range of the RFID tag 110.

[0020] The RFID tag 110 can be configured to communicate with an RFID reader, such as can include communicating identifying information to the RFID reader when the RFID tag 110 is scanned by the RFID reader. The RFID tag 110 can include any external shape, such as can include one or more of circular, cylindrical prism (as shown in FIG. 1), square, rectangular, rectangular prism, etc. The RFID tag 110 can include one or more RFID components, such as can include one or more of one or more antennas, one or more substrates, one or more processing chips (e.g., an integrated circuit (IC) chip), etc. In an example, the RFID tag 110 can be at least partially planar, such as can include a dimension of the RFID tag 110 in the x and / or y direction exceeding a dimension of the RFID tag 110 in the z-direction.

[0021] The RFID tag 110 can be a passive system (e.g., operating based on power received with one or more antennas), such as can allow the RFID tag 110 to operate without any power storage system (e.g., battery). The RFID tag 110 can be configured to receive a “read” signal from an RFID reader and send back a “return” signal. The “read” signal can include information, or can just be a wave at a carrier frequency that powers the RFID tag 110, such as through an antenna. For example, the RFID tag 110 might only be powered on when it is being read.

[0022] The RFID tag 110 can be a near-field and / or far-field RFID tag. The RFID tag 110 can be configured to interact with one or more of a near-field of electromagnetic waves (e.g., designed to couple to another antenna magnetically, such as when a distance to the other antenna is less than approximately one wavelength of the carrier frequency, such as can result in the magnetic field dominating the electric field) or a far-field of electromagnetic waves (e.g., designed to interact with an electromagnetic wave generated by another antenna, such as when a distance to the other antenna is greater than approximately one wavelength of the carrierfrequency, such as can result in the electric field dominating the magnetic field). In an example, the RFID tag 110 can be approximately 4 millimeters in diameter, ofbo

[0023] The secondary antenna 120 can include a substrate 122 and a conductive portion 124. In an example, the secondary antenna 120 can be at least partially planar, such as can include a dimension of the secondary antenna 120 in the x and / or y direction exceeding a dimension of the secondary antenna 120 in the z-direction.

[0024] The substrate 122 can be an electrically insulating substrate, such as a glass epoxy laminate (e.g., FR-4) or other suitable dielectric. The substrate 122 can be configured to support and provide structure to one or more portions of the secondary antenna 120. For example, the substrate 122 can provide a generally flat and / or rigid surface for the construction of the remainder of the secondary antenna 120. One or more portions of the conductive portion 124 can include at least a portion that is printed, deposited, or etched onto the substrate 122, such as in a process similar to a printed circuit board (PCB) manufacturing process.

[0025] The conductive portion 124 can be disposed one or more of on or within various regions of the substrate 122 such as can include portions of the conductive portion 124 disposed on opposite sides of the substrate 122. In an example, the substrate 122 and / or the conductive portion 124 can define an aperture 126.

[0026] The aperture 126 can include a hole or cavity in the secondary antenna 120. In an example, the aperture 126 can extend all the way through the secondary antenna 120. In an example, the aperture 126 might not extend all the way through the secondary antenna 120 but may instead only extend a portion of the way through the secondary antenna 120, such as can result in the aperture 126 forming one or more of an indentation, a cup, or a divot in the secondary antenna 120. The aperture 126 can be placed anywhere on the secondary antenna 120. In the example of FIG. 1, the aperture 126 is placed near the center of the secondary antenna 120. In an example, the aperture 126 can be placed near a side or corner of the secondary antenna 120. In an example, the aperture 126 might not be fully surrounded by the secondary antenna 120, such as can include the aperture 126 being an indentation in a side or corner of the secondary antenna 120. For example, the aperture 126 can form an indentation, such as a semicircular indentation, in a side of the secondary antenna 120 and might not be surrounded across 360 degrees by the secondary antenna 120. For example, the aperture 126 can be surrounded by the secondary antenna 120 across on one or more of 90 degrees or more, 180 degrees or more, 270 degrees or more, etc.

[0027] The aperture 126 can be one or more of sized or shaped to receive and / or fit, including snugly fit, the RFID tag 110. In an example, the RFID tag 110 can be at least partiallyinserted into the aperture 126 (e.g., such as inserted in the positive and / or negative z direction) such as can include inserting the RFID tag 110 into the aperture 126 so that 10 percent or more, 20 percent or more, 30 percent or more, 50 percent or more, 80 percent or more, or 100 percent of the RFID tag 110 is surrounded in the x and y directions by the secondary antenna 120. In the example of FIG. 1, the RFID tag 110 is shown inserted into the aperture 126 so that the RFID tag 110 is 100 percent surrounded by the secondary antenna 120 in the x and y directions.

[0028] The secondary antenna 120 and / or the RFID tag 110 can be configured such that the secondary antenna 120 and the RFID tag 110 electromagnetically couple. For example, the secondary antenna 120 can receive a signal and pass the signal to the RFID tag 110 through electromagnetic coupling (e.g., inductive coupling, such as can include coupling largely through a magnetic field), and / or the RFID tag 110 can generate a signal and pass the signal to the secondary antenna 120 through electromagnetic coupling. In an example, the RFID tag 110 and the secondary antenna 120 might not be configured for conductive electrical coupling therebetween, such as can include the RFID tag 110 having an outer surface with no conductive regions. In this example, the coupling and / or interaction between the RFID tag 110 and the secondary antenna 120 can be entirely through electromagnetic waves (e.g., a wireless connection).

[0029] FIG. 2 is a cutaway top view drawing of an example of portions of the RFID system 100 of FIG. 1, where at the secondary antenna 120 has been removed. FIG. 2 shows that the RFID tag 110 can include a primary antenna 250, an IC chip 260, and a substrate 270.

[0030] The substrate 270 can be an electrically insulating substrate, such as a glass epoxy laminate (e.g., FR-4) or other suitable dielectric. The substrate 270 can be configured to support and provide structure to one or more portions of the RFID tag 110. For example, the substrate 270 can provide a generally flat and / or rigid surface for the construction of the remainder of the RFID tag 110. One or more portions of the primary antenna 250 can include at least a portion that is printed, deposited, or etched onto the substrate 270, such as in a process similar to a printed circuit board (PCB) manufacturing process. For example, the primary antenna 250 can be at least partially printed on the substrate 270. The substrate 270 can be generally sized and / or shaped to fit within the aperture 126.

[0031] The primary antenna 250 can be any type of antenna. The primary antenna 250 can be configured as a near field antenna (e.g., designed to couple to another antenna magnetically, such as when a distance to the other antenna is less than approximately one wavelength of the carrier frequency), such as a near field coil (as shown in FIG. 2). The primary antenna 250 can be configured as a far field antenna (e.g., designed to interact with anelectromagnetic wave generated by another antenna, such as when a distance to the other antenna is greater than approximately one wavelength of the carrier frequency), such as a dipole antenna. In an example, the RFID tag 110 can include a near field antenna and a far field antenna, such as can allow the RFID tag 110 to be read by an RFID reader from a larger range of distances. The primary antenna 250 can be energized by the carrier frequency generated by the RFID reader, such as can provide a voltage and current on the primary antenna 250. This voltage and current can be used to power the IC chip 260 while the primary antenna 250 is receiving the carrier frequency.

[0032] The IC chip 260 can be configured to communicate with the RFID reader. The IC chip 260 can be coupled to the primary antenna 250. The IC chip 260 can communicate with the RFID reader by one or more of altering an impedance of the primary antenna 250, such as can be sensed by the RFID reader, or sending back a signal using the primary antenna 250, such as can be received by the RFID reader. In a near-field system, altering an impedance of the primary antenna 250 can be used. In a far-field system, sending back a return signal can be used.The IC chip 260 can be configured to transfer one or more pieces of information when it is scanned by the RFID reader. For example, the IC chip 260 can transfer one or more pieces of identifying information (e.g., a serial number, reference number, product number, etc.), such as can allow an RFID reader to determine which one of a number of RFID tags 110 are being communicated with.

[0033] FIG. 3 is a perspective drawing of an example of portions of the RFID system 100 of FIG. 1, where the RFID tag 110 has been removed. FIG. 3 shows that the secondary antenna 120 can have a first side 322 and a second side 324. In an example, there may be conductive portions 124 on both the first side 322 and the second side 324. In an example, the secondary antenna 120 can be approximately three centimeters in the x direction and 1 centimeter in the y direction. However, any suitable shape, size, diameter, width, and / or length of the secondary antenna 120 can be used, depending, for example, on the desired application.

[0034] The secondary antenna 120 can be any type of antenna. The secondary antenna 120 can be configured as a near field antenna (e.g., designed to couple to another antenna magnetically, such as when a distance to the other antenna is less than approximately one wavelength of the carrier frequency), such as a near field coil. The secondary antenna 120 can be configured as a far field antenna (e.g., designed to interact with an electromagnetic wave generated by another antenna, such as when a distance to the other antenna is greater than approximately one wavelength of the carrier frequency), such as can include one or more of adipole antenna, a meandering dipole antenna, a monopole antenna, or an F-antenna. In an example, the secondary antenna 120 can include a near field antenna and a far field antenna, such as can allow the secondary antenna 120 to interact with an RFID reader from a larger range of distances.

[0035] In an example, a surrounding portion 340 of the secondary antenna 120, such as can include a conductive surrounding portion 342 of the conductive portion 124, can be configured to at least partially surround the aperture 126, such as can improve a coupling between the secondary antenna 120 and the RFID tag 110 (e.g., through the primary antenna 250). FIG. 3 shows that the aperture 126 can be generally circular and the secondary antenna 120 can include a semicircular conductive surrounding portion 342 of the conductive portion 124 surrounding the aperture 126 in the surrounding portion 340. In the example of FIG. 3, the conductive surrounding portion 342 inside the surrounding portion 340 surrounds the aperture 126 across approximately 225 degrees, but the conductive surrounding portion 342 could surround the aperture 126 across any angle, such as can include one or more of 90 degrees or more, 180 degrees or more, 270 degrees or more, or 360 degrees.

[0036] FIG. 3 shows that the secondary antenna 120 can include a dipole antenna with each of the poles forming an “F” configuration. The poles can come together at connection point 344, such as can include one or more of a conductive connection (e.g., a continuation of the conductive material from both the poles through the connection point 344), a resistive connection (e.g., a resistive element is coupled between the poles, such as can tune one or more properties of the secondary antenna 120) or an open connection (e.g., the poles are not coupled at connection point 344). The connection point 344 can be positioned near the aperture 126, such as can include within the surrounding portion 340. In an example that includes conductive portions 124 on both the first side 322 and the second side 324, one or more of the conductive portions on the first side 322 can be connected to one or more of the conductive portions on the second side 324 using one or more of through holes, plated vias, filled vias, slugs, etc.

[0037] In an example, the secondary antenna 120 can be a passive device, such as can include the secondary antenna 120 not including any integrated circuit chips (e.g., a chip capable of executing instructions, etc.) and / or any active components (e.g., no transistors, diodes, etc.). For example, the secondary antenna 120 can be constructed entirely of a substrate 122 and one or more conductive portions 124 (e.g., including insulating substrate and conductive material without more). In an example, the secondary antenna 120 can include an IC chip, such as can allow the secondary antenna 120 to transmit identifying information and / or other information independent of the RFID tag 110.

[0038] The secondary antenna 120 can be configured to extend or otherwise adjust an operating range of the RFID tag 110. The operating range of the RFID tag 110 can include one or more of a range at which the RFID tag 110 can be read by an RFID reader, the range at which the RFID tag 110 can be detected by an RFID reader, the range at which the RFID tag 110 can be detected by a system designed to detect RFID devices, etc. For example, the operating range of the RFID system 100 including the RFID tag 110 and the secondary antenna 120 can be greater than the operating range of the RFID tag 110 alone, such as can include one or more of at least twice as large (e.g., the operating range of the RFID system 100 with the RFID tag 110 and the secondary antenna 120 is at least twice as long as the operating range of the RFID tag 110 alone), at least three times as large, at least four times as large, at least ten times as large, at least 100 times as large, etc.

[0039] For example, the secondary antenna 120 can be configured to have a larger range than the primary antenna 250 such as due to one or more of size (e.g., the secondary antenna 120 can be larger than the primary antenna 250, such as can allow the secondary antenna 120 to generate a specified level of interaction with a weaker electromagnetic wave), a configuration (e.g., the secondary antenna 120 can be configured to interact with a far-field of electromagnetic waves, while the primary antenna 250 can be configured to interact with a near field of an electromagnetic waves, such as can allow the secondary antenna 120 to receive a signal from a device (e.g., an RFID reader) while a greater distance from the device), or other differences. The secondary antenna 120 can be configured to couple to the RFID tag 110, such as through the primary antenna 250, such as can allow the secondary antenna 120 to extend a range of the RFID tag 110 by receiving and / or transmitting signals for the RFID tag 110. For example, the secondary antenna 120 can be energized by the carrier frequency generated by the RFID reader, such as can provide a voltage and current on the primary antenna 250 through coupling with the secondary antenna 120. This voltage and current can be used to power the IC chip 260 while the secondary antenna 120 is receiving the carrier frequency. The IC chip 260 can adjust a parameter of the primary antenna 250 or otherwise generate a signal on the primary antenna 250, and this signal can then be transmitted using the secondary antenna 120, such as due to coupling between the primary antenna 250 and the secondary antenna 120.

[0040] In an example, the secondary antenna 120 can be configured to be physically separable from the RFID tag 110. For example, the secondary antenna 120 and the RFID tag 110 can be separate physical components. The secondary antenna 120 can be configured to electromagnetically couple to the primary antenna 250, such as when the RFID tag 110 and the secondary antenna 120 are near physically (e.g., physically engaged), such as when the RFIDtag 110 is at least partially inserted into the aperture 126. The secondary antenna 120 can be configured not to electromagnetically couple with the primary antenna 250 when the secondary antenna 120 and the RFID tag 110 are not near physically (e.g., physically disengaged), such as can include when the RFID tag 110 is not at least partially inserted into the aperture 126, or when the RFID tag 110 is a specified distance (e.g., one centimeter, five centimeters, 10 centimeters, 50 centimeters, etc.) from the secondary antenna 120.

[0041] In an example, the secondary antenna 120 can be configured to interact with a far-field of electromagnetic waves and the primary antenna 250 can be configured to interact with a near-field of electromagnetic waves. In an example, the RFID system 100 can be in a “long-range” state when the secondary antenna 120 is engaged with the RFID tag 110 and be in a “short-range” state when the secondary antenna 120 is not engaged with the RFID tag 110.

[0042] In an example, an RFID tag 110 can be placed on an object to be tracked, such as can include an object in an inventory. When the object is placed in the inventory, the secondary antenna 120 can be engaged with the RFID tag 110, such as can place the RFID system 100 in the “long-range” state. When the object is removed from the inventory, the secondary antenna 120 can be disengaged from the RFID tag 110, such as can place the RFID system 100 in the “short-range” state.

[0043] In an example, the RFID tag 110 can include a strain gauge, such as can be configured to measure a level or degree of physical deflection of the RFID tag 110. The RFID tag 110 can be rigidly attached to a structural member (e.g., a structural member of an airframe, a helicopter blade, a structural member of a bridge, etc.), such as can result in the level of deflection of the RFID tag 110 corresponding to a level of deflection in the structural member, such as can be indicative of a level of strain in the structural member. The secondary antenna 120 can be flexibly attached to one or more of the RFID tag 110 or the structural member. This can allow the secondary antenna 120 to behave at least partially independently of the structural member, such as can reduce an effect the RFID system 100 has on the measured strain in the structural member. For example by preventing the secondary antenna 120 from exerting a force on the structural member, or reducing and / or otherwise altering the force the secondary antenna 120 exerts, the strain measured by the RFID tag 110 can be more accurate as compared to a system that does not allow a portion of the system to flex independent of the strain measuring component. This can include having the substrate 270 of the RFID tag 110 separate from the substrate 122 of the secondary antenna 120. In an example, the secondary antenna 120 can be configured to be flexible, such as can include the substrate 122 being a flexible substrate.

[0044] The secondary antenna 120 and / or the primary antenna 250 can be configured to electromagnetically couple across a range of one or more of orientation, position, distance, etc. For example, the secondary antenna 120 can be one or more of symmetric when flipped about the x and / or y axis, or can be functional but not symmetric when flipped about the x and / or y axis. This can help to prevent the secondary antenna 120 from being engaged with the RFID tag 110 “backwards”, as both orientations of inserting the RFID tag 110 in the aperture 126 can be functional. The electromagnetic coupling between the secondary antenna 120 and the primary antenna 250 can be rotationally symmetric, or largely so, about the z axis. For example, the secondary antenna 120 can electromagnetically couple with the primary antenna 250 across a range of rotational positions about the z axis, such as can include any rotational orientation. The electromagnetic coupling between the secondary antenna 120 and the primary antenna 250 can occur at a specified level (e.g., a level necessary to allow the RFID tag 110 to have a specified operating range) throughout a range of insertion levels, such as from 10 percent inserted to 190 percent inserted (e.g., barely inserted through inserted beyond level and continuing out the other side), from 50 percent to 150 percent, etc. In an example, the primary antenna 250 can electromagnetically couple to the secondary antenna 120 at a specified level even if the RFID tag 110 is not inserted into the aperture 126, but is in close enough physical proximity (e.g., the RFID tag 110 is aligned with the aperture 126 but not inserted, the RFID tag 110 is offset from the aperture 126 and not inserted, etc.).

[0045] FIGS. 4 and 5 are drawings of an example of portions of a RFID system 100 disposed on a firearm 402. In the example of FIG. 4, the object to be tracked can include the firearm 402. The firearm 402 can include any form or model of firearm or other weapon (e.g., a handgun, a long gun, a taser, a knife). In an example, the RFID system 100 could be similarly used for other military weapons and equipment, such as can include one or more of handheld weapons, light artillery, heavy artillery, ammunition (e.g., artillery shells), vehicles, navigation systems, radio equipment, etc. In an example, the firearm 402 can be included in a firearm inventory, such as can include an inventory of firearms at an armory, base, etc. Tracking of one or more firearms in the inventory can be desirable for one or more of maintenance information (e.g., how long a firearm has been deployed outside the inventory), security information (e.g., verifying which firearms are in an inventory, which firearms are not in an inventory, when various firearms were placed in and / or removed from the inventory, etc.), or other information. In the example of FIG. 4, the secondary antenna 120 is not engaged with the RFID tag 110, such as can result in the RFID system 100 being in the “short-range” state.

[0046] The RFID tag 110 can be disposed on the firearm 402 in any fashion, such as can include one or more of adhesive tape, adhesive glues, screws or other fasteners, etc. In an example, the RFID tag 110 can be disposed on the firearm 402 in a largely permanent fashion, such as can make it difficult to remove the RFID tag 110 from the firearm 402 (e.g., difficult to remove quickly, difficult to remove without the correct tools, difficult to remove without damaging one or more of the RFID tag 110 or the firearm 402, etc.). The RFID tag 110 can be disposed anywhere on the firearm, such as can include the shoulder stock of the firearm as shown in FIG. 4.

[0047] In the example of FIG. 5, the secondary antenna 120 can be engaged with the RFID tag 110 such as can place the RFID system 100 in a “long-range” state. The secondary antenna 120 can be held in engagement with the RFID tag 110. In an example, the secondary antenna 120 can be held in engagement with the RFID tag 110 through one or more of a temporary adhesive (e.g., an adhesive on one or more sides of the secondary antenna 120 that can allow the secondary antenna 120 to stick to the object to be tracked, such as the shoulder stock of the firearm 402), a friction fit with the RFID tag 110 (e.g., the aperture 126 is sized to form a friction fit with the RFID tag 110), a clip system with the RFID tag 110 (e.g., the secondary antenna 120 is configured to be attached to the RFID tag 110 by a clip, such as a spring clip, such as can interface with one or more grooves in the RFID tag 110), a bayonet connection or other connection mechanism, a screw-fit connection, such as where the RFID tag 110 and the secondary antenna 120 include complementary threading, or a strap, such as the strap 520. The strap 520 can form a loop that is connected to the secondary antenna 120 at one or more places (e.g., at the top of the secondary antenna 120 and the bottom of the secondary antenna 120). The strap 520 can be an elastic strap, such as can allow the strap 520 to change in circumference and / or the strap 520 can be adjustable, such as can allow a circumference of the strap 520 to be adjusted.

[0048] FIG. 5 shows that the strap 520 can surround the shoulder stock and hold the secondary antenna 120 in engagement with the RFID tag 110. The RFID tag 110 and the aperture 126 can help align the RFID tag 110 and the secondary antenna 120. For example, the strap 520 can generally hold the secondary antenna 120 against the shoulder stock, but the aperture 126 and the RFID tag 110 can help align the RFID tag 110 with the aperture 126 (e.g., the RFID tag 110 can push against one or more sides of the aperture 126 to keep the secondary antenna 120 from moving out of engagement vertically or laterally.

[0049] The secondary antenna 120 can be configured to be used near a conductive material (e.g., a metal material, such as the material of a firearm). For example, the secondary antenna 120 can be configured as a mount-on-metal antenna.

[0050] FIG. 6 is a block drawing of an example of portions of an RFID system 600, including portions of an environment in which the RFID system 600 can be used. The RFID system 600 can be used for tracking one or more objects (e.g., a first object 670, a second object 671, and a third object 672) in an inventory. In an example, the inventory can include one object, two objects, two or more objects, three objects (as shown in FIG. 6), 10 or more objects, etc.

[0051] FIG. 6 shows that respective RFID tags 110 can be disposed on respective ones of the objects in the inventory. For example, a first RFID tag 680 can be disposed on the first object 670, a second RFID tag 681 can be disposed on the second object 671, and a third RFID tag 682 can be disposed on the third object 672.

[0052] FIG. 6 shows that there can be an inventory area 660, such as can be used to store one or more of the objects in the inventory, such as when the objects are not being actively used (e.g., the inventory can be used to store objects between uses). For each of the respective objects, a secondary antenna 120 can be engaged with the RFID tag 110 on the object when the object is stored in the inventory area 660. For example, the first object 670 can include a first secondary antenna 690 engaged with the first RFID tag 680, the second object 671 can include a second secondary antenna 691 engaged with the second RFID tag 681, and the third object 672 can include a third secondary antenna 692 engaged with the third RFID tag 682.

[0053] The RFID system can also include an RFID reader 650. The RFID reader 650 can be configured to communicate with one or more of the RFID tags, such as can include all of the RFID tags. The RFID reader 650 can be configured to scan the inventory area 660 (e.g., such as by issuing a “read” signal), or scan one or more portions of the inventory area 660, and determine which objects are present in the inventory area 660 or area scanned, such as by cataloguing the “return” signals received. For example, each of the RFID tags can have a unique identifying code that they transmit in response to a “read” signal, and the RFID reader 650 can determine which objects are present in the inventory based on which identifying codes are received.

[0054] The RFID system 600 can be configured so that the RFID reader 650 can communicate with the RFID tag on an object stored generally anywhere within the inventory area 660 when the RFID tag is engaged with a secondary antenna (e.g., a range of the RFID system 600 extends generally throughout the entire inventory area 660, such that the objectscan be placed generally anywhere within the inventory area 660 and be read by the RFID reader 650). In an example, the RFID reader 650 might not be able to communicate with an RFID tag coupled to a secondary antenna throughout the entire inventory area 660, such as can include one or more portions of the area not being readable. In this example, an object can be “scanned in” and / or “scanned out” by passing within range of an RFID reader, such as can include an RFID reader near a doorway of the inventory area 660. For example, an RFID tag on an object could be scanned near the entrance of the inventory area 660 when it is deposited in the inventory area 660 and / or when it exits or is retrieved from the inventory area 660.

[0055] When an object is removed from the inventory area 660, the respective secondary antenna can be disengaged from the respective RFID tag and / or removed from the object. The operating range of the RFID tag on the object out of the inventory can be limited, such as can include the “short-range” state operating range 632 shown with respect to the first RFID tag 680. This can reduce a detectible range of the respective RFID tags and / or make the portion of the RFID system 100 attached to the object one or more of lighter, less bulky (e.g., the RFID tag 110 is less bulky than the secondary antenna 120 and the RFID tag 110 together), etc. In an example, the RFID reader 650 cannot communicate with an object stored in the inventory area 660 when a secondary antenna is not engaged with the RFID tag on that object. In an example, the RFID reader 650 cannot communicate with an object stored in as large an area of the inventory area 660 when a secondary antenna is not engaged with the RFID tag on that object (e.g., the RFID reader 650 may still be able to communicate with objects in the inventory area 660 not engaged with a secondary antenna that are close enough to the RFID reader 650, such as within the “short-range” state operating range 632.)

[0056] In an example, one or more secondary antennas can be stored, such as can include stored in the inventory area 660, when they are not disposed on an object (e.g., not engaged with an RFID tag). In an example, one or more of the secondary antennas can be interchangeable (e.g., one secondary antenna will engage with multiple RFID tags and / or couple to multiple objects). For example, the secondary antennas can be identical or very similar, and any unused secondary antenna can be coupled to an object as it is stored in the inventory, in contrast to each object having a designated secondary antenna. In an example, there can be two or more classes of secondary antennas that are interchangeable with other secondary antennas in the class (e.g., a class of secondary antennas for rifles that are couplable to rifles and RFID tags disposed on rifles and a class of secondary antennas for handguns that are couplable to handguns and the RFID tags disposed on handguns). The classes of secondary antenna can differ in one or more of size, shape, configuration, connection means, etc.

[0057] FIG. 7 is a diagram showing an example of a method 700 for operating portions of an RFID system, such as the RFID system 600 shown in FIG. 6. The method 700 can include a method of tracking two or more objects in an inventory. At step 705, respective RFID tags can be disposed on respective ones of the two or more objects. For example, disposing the first RFID tag 680 on the first object 670, disposing the second RFID tag 681 on the second object 671, etc.

[0058] At step 710, such as may be performed for each of the two or more objects, a secondary antenna can be engaged with the RFID tag disposed on the object when the object is stored in the inventory. For example, engaging the first secondary antenna 690 with the first RFID tag 680 when the first object 670 is stored in the inventory area 660.

[0059] At step 715, such as may be performed for each of the two or more objects, the secondary antenna can be disengaged from the RFID tag disposed on the object when the object is removed from the inventory. For example, disengaging the first secondary antenna 690 from the first RFID tag 680 when the first object 670 is removed from the inventory area 660.

[0060] The method 700 can be used, for example, to track an inventory on a military installation, such as can include an inventory of firearms. For example, one or more firearms in the inventory can be assigned respective RFID tags including information that identifies the respective firearms. The respective RFID tags can be disposed on the respective firearms. The firearms can be stored in an inventory area, with respective secondary antennas coupled to the respective RFID tags, when the firearms are not in use. An RFID reader in and / or near the storage area can scan the storage area (e.g., scan recurrently, scan when requested) to determine which firearms are present. When a firearm is removed from the inventory area for use (e.g., a patrol, a mission), the secondary antenna can be removed, such as can reduce an operating range of the RFID tag, such as can improve a secrecy of the user’s position. When the firearm is placed back in the inventory, a secondary antenna can be engaged with the RFID tag to increase a range of the RFID tag, such as can allow the RFID tag to be read by the RFID reader.

[0061] The shown order of steps is not intended to be a limitation on the order the steps are performed in. In an example, two or more steps may be performed simultaneously or at least partially concurrently.Additional Notes & Examples

[0062] Example 1 is a method of tracking two or more objects in an inventory, the method comprising: disposing respective RFID tags on respective ones of the two or moreobjects; for each object of the two or more objects: engaging a secondary antenna with the RFID tag disposed on the object when the object is in an inventory area; and disengaging the secondary antenna from the RFID tag disposed on the object when the object is removed from the inventory area; wherein the secondary antenna is configured to electromagnetically couple with a primary antenna in the RFID tag disposed on the object when the secondary antenna is engaged with the RFID tag disposed on the object, and wherein the secondary antenna is configured to increase an operating range of the RFID tag disposed on the object when the secondary antenna is engaged with the RFID tag disposed on the object.

[0063] In Example 2, the subject matter of Example 1 optionally includes scanning the inventory, using an RFID reader, wherein the RFID reader is configured to identify respective ones of the two or more objects that are present in the inventory area.

[0064] In Example 3, the subject matter of Example 2 optionally includes wherein the RFID reader can communicate with the RFID tag disposed on a corresponding object when the corresponding object is placed within the inventory area and the RFID tag disposed on the corresponding object is engaged with a respective secondary antenna, and wherein the RFID reader cannot communicate with the RFID tag disposed on the corresponding object when the RFID tag disposed on the corresponding object is not engaged with any secondary antenna.

[0065] In Example 4, the subject matter of any one or more of Examples 1-3 optionally include wherein the two or more objects are firearms.

[0066] In Example 5, the subject matter of Example 4 optionally includes disposing the secondary antenna on a firearm as the firearm is placed into the inventory, wherein the secondary antenna is disposed on the firearm such that it is physically attached to the firearm and engaged with the RFID tag; and removing the secondary antenna from the firearm as the firearm is removed from the inventory.

[0067] In Example 6, the subject matter of Example 5 optionally includes storing one or more secondary antennas in the inventory area when the one or more secondary antennas are not disposed on a firearm, wherein the one or more secondary antennas are interchangeable.

[0068] Example 7 is a radio frequency identification (RFID) system for tracking an inventory of firearms, the RFID system comprising: one or more RFID tags, disposed on one or more firearms respectively, wherein each RFID tag includes: a primary antenna, and an integrated circuit (IC) chip, coupled to the primary antenna; and one or more secondary antennas, wherein each secondary antenna is configured to electromagnetically couple with any of the one or more RFID tags and wherein each secondary antenna is configured fortemporary attachment to a firearm when the firearm is placed in storage and is physically separable from the firearm when the firearm is removed from storage.

[0069] In Example 8, the subject matter of Example 7 optionally includes wherein the primary antenna of each RFID tag is configured to interact with a near-field of electromagnetic waves, and wherein the one or more secondary antennas are configured to interact with a far- field of electromagnetic waves.

[0070] In Example 9, the subject matter of any one or more of Examples 7-8 optionally include an RFID reader, wherein the RFID reader is positioned to communicate with any of the one or more RFID tags correspondingly electromagnetically coupled with any of the secondary antennas, and wherein the RFID reader is configured to determine which of the one or more firearms are in storage.

[0071] Example 10 is a radio frequency identification (RFID) system, the RFID system comprising: an RFID tag, the RFID tag including: a primary antenna; an integrated circuit (IC) chip, coupled to the primary antenna; and a first insulating substrate, wherein the primary antenna and the IC chip are disposed on the first insulating substrate; and a secondary antenna, comprising a second insulating substrate separate from the first insulating substrate and an aperture defined in the second insulating substrate, wherein a conductive portion of the secondary antenna is configured to at least partially surround the aperture; wherein the RFID tag is configured to engage with the secondary antenna by at least partially inserting into the aperture; and wherein the secondary antenna is configured to electromagnetically couple with the primary antenna when the RFID tag is at least partially inserted into the aperture.

[0072] In Example 11, the subject matter of Example 10 optionally includes wherein the secondary antenna is configured to be physically separable from the RFID tag, wherein the secondary antenna is configured not to electromagnetically couple with the primary antenna when the secondary antenna is separated from the RFID tag.

[0073] In Example 12, the subject matter of Example 11 optionally includes wherein the secondary antenna comprises attachment means configured for attachment to at least one of the RFID tag or an object the RFID tag is attached to.

[0074] In Example 13, the subject matter of Example 12 optionally includes wherein the attachment means includes a temporary adhesive.

[0075] In Example 14, the subject matter of any one or more of Examples 11-13 optionally include wherein the RFID system is configured to be in a “long-range” state when the secondary antenna is engaged with the RFID tag and is electromagnetically coupled with the primary antenna, and wherein the RFID system is configured to be in a “short-range” statewhen the secondary antenna is not engaged with the RFID tag and is not electromagnetically coupled with the primary antenna, wherein an operating range of the RFID tag in the “long- range” state is at least twice as large as an operating range of the RFID tag in the “short-range” state.

[0076] In Example 15, the subject matter of Example 14 optionally includes wherein the RFID tag is configured for attachment to a firearm, wherein the secondary antenna is part of a firearm inventory system, wherein the secondary antenna is configured to be engaged with the primary antenna when the firearm is stored in an inventory, placing the RFID system in the “long-range” state, and wherein the secondary antenna is configured to be disengaged from the primary antenna when the firearm is not stored in the inventory, placing the RFID system in the “short-range” state.

[0077] In Example 16, the subject matter of any one or more of Examples 10-15 optionally include wherein the RFID tag includes a strain gauge, wherein the RFID tag is configured to be rigidly attached to a structural member, and wherein the secondary antenna is configured to be flexibly attached to at least one of the RFID tag or the structural member.

[0078] In Example 17, the subject matter of any one or more of Examples 10-16 optionally include wherein the primary antenna is configured to interact with a near-field of electromagnetic waves, and wherein the secondary antenna is configured to interact with a far- field of electromagnetic waves.

[0079] In Example 18, the subject matter of Example 17 optionally includes wherein the primary antenna is a near-field coil antenna.

[0080] In Example 19, the subject matter of Example 18 optionally includes wherein the electromagnetic coupling between the primary antenna and the secondary antenna is inductive coupling.

[0081] In Example 20, the subject matter of any one or more of Examples 10-19 optionally include wherein the RFID tag is configured to transmit identifying information when an RFID reader scans the RFID system.

[0082] Example 21 is at least one machine-readable medium including instructions that, when executed by processing circuitry, cause the processing circuitry to perform operations to implement of any of Examples 1-20.

[0083] Example 22 is an apparatus comprising means to implement of any of Examples 1-20.

[0084] Example 23 is a system to implement of any of Examples 1-20.

[0085] Example 24 is a method to implement of any of Examples 1-20.

[0086] Each of the non-limiting aspects above can stand on its own or can be combined in various permutations or combinations with one or more of the other aspects or other subject matter described in this document.

[0087] In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc., are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0088] Method examples described herein can be machine or computer-implemented at least in part. Some examples can include a computer-readable medium or machine-readable medium encoded with instructions operable to configure an electronic device to perform methods as described in the above examples. An implementation of such methods can include code, such as microcode, assembly language code, a higher-level language code, or the like. Such code can include computer readable instructions for performing various methods. The code may form portions of computer program products. Such instructions can be read and executed by one or more processors to enable performance of operations comprising a method, for example. The instructions are in any suitable form, such as but not limited to source code, compiled code, interpreted code, executable code, static code, dynamic code, and the like.

Claims

What is claimed is:

1. A method of tracking two or more objects in an inventory, the method comprising: disposing respective RFID tags on respective ones of the two or more objects; for each object of the two or more objects: engaging a secondary antenna with the RFID tag disposed on the object when the object is in an inventory area; and disengaging the secondary antenna from the RFID tag disposed on the object when the object is removed from the inventory area; wherein the secondary antenna is configured to electromagnetically couple with a primary antenna in the RFID tag disposed on the object when the secondary antenna is engaged with the RFID tag disposed on the object, and wherein the secondary antenna is configured to increase an operating range of the RFID tag disposed on the object when the secondary antenna is engaged with the RFID tag disposed on the object.

2. The method of claim 1, further comprising: scanning the inventory, using an RFID reader, wherein the RFID reader is configured to identify respective ones of the two or more objects that are present in the inventory area.

3. The method of claim 2, wherein the RFID reader can communicate with the RFID tag disposed on a corresponding object when the corresponding object is placed within the inventory area and the RFID tag disposed on the corresponding object is engaged with a respective secondary antenna, and wherein the RFID reader cannot communicate with the RFID tag disposed on the corresponding object when the RFID tag disposed on the corresponding object is not engaged with any secondary antenna.

4. The method of claim 2, wherein the RFID reader can communicate in a far-field of electromagnetic waves with the RFID tag disposed on a corresponding object when the corresponding object is placed within the inventory area and the RFID tag disposed on the corresponding object is engaged with a respective secondary antenna, and wherein the RFID reader cannot communicate in the far-field with the RFID tag disposed on the corresponding object when the RFID tag disposed on the corresponding object is not engaged with any secondary antenna.

5. The method of claim 4, wherein the RFID reader can communicate in a near-field of electromagnetic waves with the RFID tag disposed on the corresponding object when the RFID tag disposed on the corresponding object is not engaged with any secondary antenna.

6. The method of any one of claims 1 to 5, wherein the two or more objects are firearms.

7. The method of claim 6, comprising: disposing the secondary antenna on a firearm as the firearm is placed into the inventory, wherein the secondary antenna is disposed on the firearm such that it is physically attached to the firearm and engaged with the RFID tag; and removing the secondary antenna from the firearm as the firearm is removed from the inventory.

8. The method of claim 7, comprising: storing one or more secondary antennas in the inventory area when the one or more secondary antennas are not disposed on a firearm, wherein the one or more secondary antennas are interchangeable.

9. A radio frequency identification (RFID) system for tracking an inventory of firearms, the RFID system comprising: one or more RFID tags, disposed on one or more firearms respectively, wherein each RFID tag includes: a primary antenna, and an integrated circuit (IC) chip, coupled to the primary antenna; and one or more secondary antennas, wherein each secondary antenna is configured to electromagnetically couple with any of the one or more RFID tags and wherein each secondary antenna is configured for temporary attachment to a firearm when the firearm is placed in storage and is physically separable from the firearm when the firearm is removed from storage.

10. The RFID system of claim 9, wherein the primary antenna of each RFID tag is configured to interact with a near-field of electromagnetic waves, and wherein the one or more secondary antennas are configured to interact with a far-field of electromagnetic waves.

11. The RFID system of claim 9 or 10, further comprising an RFID reader, wherein the RFID reader is positioned to communicate with any of the one or more RFID tags correspondingly electromagnetically coupled with any of the secondary antennas, and wherein the RFID reader is configured to determine which of the one or more firearms are in storage.

12. A radio frequency identification (RFID) system comprising: an RFID tag, the RFID tag including: a primary antenna; an integrated circuit (IC) chip, coupled to the primary antenna; and a first insulating substrate, wherein the primary antenna and the IC chip are disposed on the first insulating substrate; and a secondary antenna, comprising a second insulating substrate separate from the first insulating substrate and an aperture defined in the second insulating substrate, wherein a conductive portion of the secondary antenna is configured to at least partially surround the aperture; wherein the RFID tag is configured to engage with the secondary antenna by at least partially inserting into the aperture; and wherein the secondary antenna is configured to electromagnetically couple with the primary antenna when the RFID tag is at least partially inserted into the aperture.

13. The RFID system of claim 12, wherein the secondary antenna is configured to be physically separable from the RFID tag, wherein the secondary antenna is configured not to electromagnetically couple with the primary antenna when the secondary antenna is separated from the RFID tag.

14. The RFID system of claim 12 or 13, wherein the secondary antenna comprises attachment means configured for attachment to at least one of the RFID tag or an object the RFID tag is attached to.

15. The RFID system of claim 14, wherein the attachment means includes a temporary adhesive.

16. The RFID system of any one of claims 12 to 15, wherein the RFID system is configured to be in a “long-range” state when the secondary antenna is engaged with the RFID tag and is electromagnetically coupled with the primary antenna, and wherein the RFID system is configured to be in a “short-range” state when the secondary antenna is not engaged with the RFID tag and is not electromagnetically coupled with the primary antenna, wherein an operating range of the RFID tag in the “long-range” state is at least twice as large as an operating range of the RFID tag in the “short-range” state.

17. The RFID system of claim 16, wherein the RFID tag is configured for attachment to a firearm, wherein the secondary antenna is part of a firearm inventory system, wherein the secondary antenna is configured to be engaged with the primary antenna when the firearm is stored in an inventory, placing the RFID system in the “long-range” state, and wherein the secondary antenna is configured to be disengaged from the primary antenna when the firearm is not stored in the inventory, placing the RFID system in the “short-range” state.

18. The RFID system of any one of claims 12 to 17, wherein the RFID tag includes a strain gauge, wherein the RFID tag is configured to be rigidly attached to a structural member, and wherein the secondary antenna is configured to be flexibly attached to at least one of the RFID tag or the structural member.

19. The RFID system of any one of claims 12 to 18, wherein the primary antenna is configured to interact with a near-field of electromagnetic waves, and wherein the secondary antenna is configured to interact with a far-field of electromagnetic waves.

20. The RFID system of any one of claims 12 to 19, wherein the primary antenna is a near-field coil antenna.

21. The RFID system of any one of claims 12 to 20, wherein the electromagnetic coupling between the primary antenna and the secondary antenna is inductive coupling.

22. The RFID system of any one of claims 12 to 21, wherein the RFID tag is configured to transmit identifying information when an RFID reader scans the RFID system.

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