Patent Application
20070063847
This invention relates generally to radio frequency identification (RFID) systems, and more particularly, to systems and methods for monitoring components using RFID systems.
Component monitoring for transportation vehicles, for example, airplanes, is essential to ensure safety, security, and operational readiness. At least some airlines rely on personnel to physically inspect doors, latches, and containers to verify their status and location. However, relying on the skill level of the inspector may result in errors and/or the expenditure of significant man hours. Currently, life vests can be detected on the airplane by attaching an RFID tag onto the vest. By this method, an RFID reader can detect the plurality of life vests on the airplane, and by counting, can determine that all required vests are on the plane. This does not determine that all vests are properly stowed, as stolen items placed in passengers' baggage are still detected. Further, numerous signals are received from all the RID tags attached to all the various types of equipment present, and the desired signals may be difficult to differentiate.
Currently, life vest tampering can be detected by placing a frangible RFID tag on the life vest pocket, such that removing the life vest destroys the RFID tag. Again, an RFID reader can detect the life vests on the airplane, and can, by counting, verify that all the required vests are present and not tampered with. In this case, a hand-held short range RFID tag reader can be used to find the tampered life vest pocket by looking for the absence of an RFID response from the tampered seat group. The stolen vest cannot be detected at all, and the problem of multiple signals remains.
Other airlines rely on elaborate system of wired sensors positioned throughout the airplane. Each door, latch, and component may be wired to visually or audibly to notify flight personnel regarding their status. However, wired systems add weight and complexity to the design of airplanes.
In one embodiment, a system for monitoring a vehicle includes at least one radio frequency identification (RFID) system comprising at least one transceiver and a plurality of RFID tags, the tags coupled to a plurality of vehicle components, a plurality of vehicle component retaining assemblies coupled to the plurality of components and operatively configured to substantially shield the amount of radio frequency (RF) energy received from the transceiver by each tag in a first position and unshield each tag in a second position, and an alert system for receiving information regarding the plurality of vehicle components and for generating an alert based on the information received.
In another embodiment, a method for monitoring vehicle components includes coupling at least one RFID tag to at least one vehicle component, coupling at least one RFID transceiver configured to emit an RF energy within the vehicle to the at least one tag, shielding an amount of RF energy received by the at least one tag such that the at least one tag can not transmit to the at least one transceiver, and coupling an alert system for receiving information from the at least one transceiver.
In yet another embodiment, a monitoring system for a plurality of airplane components includes a radio frequency identification (RFID) system comprising at least one of a RFID tag and a RFID transceiver, each positioned within a fuselage of the airplane, said tag coupled to at least one of an airplane component, and at least one radio frequency (RF) energy shield extending circumferentially around said at least one RFID tag such that RF energy directed from said RFID transceiver is blocked or detuned when said at least one RF energy shield is in a first position.
As used herein a shield refers to an object configured to interrupt, obstruct, or otherwise degrade or limit the effective performance of an RFID transponder assembly. Although many objects are capable of interrupting, obstructing, or otherwise degrading or limiting the effective performance of an RFID transponder assemblies, only items configured to perform this function are referred to as sheilds.
Many specific details of certain embodiments of the invention are set forth in the following description in order to provide a thorough understanding of such embodiments. One skilled in the art, however, will understand that the present invention may have additional embodiments, or that the present invention may be practiced without several of the details described in the following description.
In addition, some door latches are linked to signs indicating the status or condition of the door. System 12 includes a plurality of RFID tags 102, 104, each coupled to a respective door 106, 108 of a lavatory 110, 112. System 12 also includes RFID antennas 116, 114, and RFID reader 14 that are complementary to RFID tags 102, 104. In the exemplary embodiment, system 12 monitors a door latch status of each latch on a respective lavatory door 106, 108. The latch status drives occupied/unoccupied signage on an aircraft and also provides an indication to the aircraft avionics for situational awareness for both pilots and flight attendants. RFID reader 14 is located proximate to lavatory area 16 to be monitored. In the exemplary embodiment, RFID readers 14 are placed above the ceiling panels 118 and reader antennas 114 and 116 are incorporated into ceiling panels 118, under carpet 120, and/or into the laminate used on the monuments to be monitored. Because reader antennas 114, 116 are able to be manufactured out of etched metal, copper tape, or thin wire; they can easily be incorporated into the space between a floor panel 122 and carpet 120, and onto the backside of ceiling panels 118 or decorative laminates used on most monuments.
Bolt 302 includes a shield 307 extending from a side of bolt 302. Shield 307 blocks RF energy in the frequencies used by RFID tag 102, 104, for example, by creating a faraday cage. In another embodiment, shield 307 detunes the RFID tag antenna sufficiently to prevent normal function. Moreover, shield 307 may be formed from an RF-opaque material, for example, carbon fiber. Bolt 302 is translatable between a first unlatched position 308 and a second latched position 310. An RFID enabled component such as an RFID tag 102, 104 is coupled to door 106, 108 proximate latch 300 and in alignment with a path of shield 307 as bolt 302 is moved between first position 308 and second position 310.
In the exemplary embodiment, lavatory latch status is read without the traditional wiring and door contact sensors using RFID tag 102, 104 and shield 307. RFID tag 102, 104 is located adjacent the latch 300 such that tag 102, 104 is uncovered when bolt 302 is in position 308 and covered when bolt 302 is in position 310. Such configuration permits tag 102, 104 to receive enough energy to transmit only when RFID tag 102, 104 is in unlatched position 308.
An optional second RFID tag 314 is coupled to door 106, 108 proximate latch 300 and in alignment with a path of shield 307 as bolt 302 is moved between second position 310 and first position 308. The RFID tags transmit different codes such that system 12 recognizes the position of bolt 302 from the received code.
System 12 is also configured to detect a missing component such as a line replaceable unit (LRU), by placing a shield plate onto the edge of the LRU mounting tray, such that the RFID tag is shielded or detuned when the LRU is present, and exposed to an RFID reader when the LRU is removed or incompletely installed.
In an alternative embodiment, an unfastened seat belt can be detected if an RFID tag is placed in the one half of the buckle such that the RFID tag is shielded when the two halves of the buckle are joined together.
In another alternative embodiment, an improperly stowed device or missing device can be detected, such as a missing life preserver, fire extinguisher, life raft or other device by attaching an RFID tag to the carrying tray for the device, and a foil metal shield onto the device being protected. As described above, the RFID tag is shielded or detuned when the equipment is properly stowed, and exposed to an RFID tag reader when removed. Accordingly, system 12 permits an instantaneous high confidence test of the presence of life vests on the aircraft prior to an overseas flight, thus reducing aircraft turn time.
For removable or frequently stolen equipment like life vests, it may be desirable to attach the RFID tag to the equipment, and the shield onto the carrier. With this alternate method, a wide range RFID reader within the cabin detects the theft, and a hand held short range RFID reader detects the stolen equipment, wherever it has been hidden.
In an alternative embodiment, system 12 is configured detect exposure to solvents or water. For example, by manufacturing RFID tag 600 with adhesive 610 configured to de-bond and permit shield 608 to peel away from substrate 602 in the presence of the solvent or water, thereby exposing RFID device 604 to detection by a reader.
In another alternative embodiment, system 12 is configured detect exposure to high temperatures. For example, by manufacturing RFID tag 600 with adhesive 610 configured to de-bond and permit shield 608 to peel away from substrate 602 in the presence of high temperatures, thereby exposing RFID device 604 to detection by a reader.
The performance of the above described embodiments can be aided by the use of disbond promoters, which react with heat or solvents to push apart the two layers of substrate 602 and shield 608. For example, a heat-sensing disbond promoter includes water filled microspheres that burst when the temperature rises above a predetermined range. At least some known materials become brittle, or liberate gas when exposed to radiation.
In still another alternative embodiment such materials are used to form an RFID shield that disbonds after exposure to a predetermined dose of radiation. At least some known materials lose structural integrity when corroded. In yet another alternative embodiment such materials are used to form an RFID shield that is sensitive to corrosion.
In another embodiment, a mass is attached to shield 608 such that a mechanical shock or vibration above a predetermined level is detected by the shield disbonds above a certain acceleration rate. Such a device is particularly useful for detecting improper handling of sensitive equipment during shipping.
In another embodiment, a reusable heat detector includes a bimetallic strip configured to couple shield 608 to substrate 602 such that shield 608 is moved away from substrate 602 outside a predetermined temperature range, and moved back to a position covering substrate 602 and RFID device 604 when the temperature returns to the predetermined temperature range.
In another embodiment, a reusable pressure detector includes a gas-filled mechanism configured to couple shield 608 to substrate 602 such that shield 608 is moved away from substrate 602 outside a predetermined pressure range, and moved back to a position covering substrate 602 and RFID device 604 when the pressure returns to the predetermined pressure range.
The foregoing description of the exemplary embodiments of the invention are described for the purposes of illustration and are not intended to be exhaustive or limiting to the precise embodiments disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not with this detailed description, but rather by the claims appended hereto.
The above-described methods and systems for identifying aircraft component parts and for mistake proof aircraft maintenance is cost-effective and highly reliable. The system permits monitoring of a plurality of vehicle components without using costly and heavy hard-wired monitoring systems. Accordingly, the methods and systems described herein facilitate operation of vehicles including aircraft in a cost-effective and reliable manner.
Exemplary embodiments of systems for identifying aircraft component parts and for mistake proof aircraft maintenance are described above in detail. The components of these systems are not limited to the specific embodiments described herein, but rather, components of each system may be utilized independently and separately from other components described herein. Each components of each system can also be used in combination with other component identifying systems.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
This application claims the priority of U.S. Provisional Patent Application No. 60/719,318 entitled “System and Method for Conditional Door Latch and Sensor Status Using Radio Frequency Identification” filed Sep. 21, 2005, which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60719318 | Sep 2005 | US |
