초록 ▼

An RFID system and method utilizes the power level of messages received from an RFID device for monitoring and/or locating and/or tracking the RFID device, e.g., and typically an object associated with the RFID device. The power level of received messages may be indicated by power level information

An RFID system and method utilizes the power level of messages received from an RFID device for monitoring and/or locating and/or tracking the RFID device, e.g., and typically an object associated with the RFID device. The power level of received messages may be indicated by power level information contained in the message, or by the strength of the received signal carrying the message, or by both. The RFID system and method may be employed to monitor a condition of an object, e.g., a closable container, as to whether it is and/or has been closed or not, including being tampered with. Messages received from the RFID device, as well as an indication of a condition, may be relayed to a remote location.

대표청구항 ▼

What is claimed is: 1. A system for monitoring a container having an exterior surface with a closable opening therein that when closed defines a closable substantially electromagnetically shielded interior space, said system comprising: an RFID device disposed in the interior space of the container

What is claimed is: 1. A system for monitoring a container having an exterior surface with a closable opening therein that when closed defines a closable substantially electromagnetically shielded interior space, said system comprising: an RFID device disposed in the interior space of the container, said RFID device comprising: a memory having stored therein unique identifying information; an antenna for transmitting and/or receiving electromagnetic signals; a modulator coupled to said memory for modulating the unique identifying information stored in said memory; and a transmitter coupled to said modulator and to said antenna for transmitting messages via said antenna, wherein each of the messages includes the modulated unique identifying information; wherein when the closable opening of the container is closed said RFID device therein is substantially electromagnetically shielded and when the container is not closed said RFID device therein is not substantially electromagnetically shielded; and a receiving device exterior to the container, said receiving device comprising a receiver for receiving messages transmitted by said RFID device interior the container; wherein messages transmitted by the RFID device interior the container when the container is closed are received by the receiving device exterior to the container with certain respective power levels and messages transmitted by the RFID device interior the container when the container is not closed are received by the receiving device exterior to the container with different respective power levels; and wherein the power levels of the messages received by said receiving device exterior the container are processed for providing an indication of whether the container is closed, is not closed, has been closed, or has been not closed, or any combination thereof, whereby an opening of and/or tampering with the container may be detected. 2. The system of claim 1 wherein the power levels of the messages received by said receiving device exterior the container are represented by an indication of received signal strength. 3. The system of claim 1 wherein a receiver of said receiving device exterior the container develops a signal representative of received signal strength of the messages received for providing the indication of whether the container is closed, is not closed, has been closed, or has been not closed, or any combination thereof. 4. The system of claim 1: wherein the memory of said RFID device has stored therein codes representing one or more transmitter power levels; wherein the modulator of said RFID device modulates the unique identifying information and the transmitter power level codes stored in said memory; wherein said transmitter transmits messages via said antenna, wherein each of the messages includes the modulated unique identifying information and a modulated transmitter power level code, wherein the power level of said transmitter is controlled in accordance with the power level code to correspond to the power level represented by the power level code in each transmitted message when each message is transmitted. 5. The system of claim 4 wherein a receiver of said receiving device exterior the container receives the transmitted messages and develops a signal representative of the received signal strength, and wherein the signal representative of the received signal strength and a power level code of the received message are processed for providing the indication of whether the container is closed, is not closed, has been closed, or has been not closed, or any combination thereof. 6. The system of claim 1 wherein said RFID device further comprises a sensor of a thing and/or of a condition at or proximate said RFID device, wherein data produced by said sensor is stored in the memory of said RFID device. 7. The system of claim 6 wherein the sensor data stored in the memory of said RFID device may be transmitted by the transmitter of said RFID device at a present time, or at a future time, or at a predetermined time, or periodically, or in response to an interrogating signal, or any combination of the foregoing. 8. The system of claim 6 wherein the thing and/or condition sensed by said sensor includes an environmental condition, or temperature, or pressure, or position, or location, or motion, or acceleration, or impact, or distance, or inertial information, or magnetic field, or electrical continuity, or altitude, or a physical parameter, or moisture, or humidity, or a chemical, or a medical parameter, or a biological substance and/or agent, or radioactivity, or optical, or light, or infrared, or an image, or an electromagnetic field, or any combination of the foregoing. 9. The system of claim 1 further comprising a second RFID device disposed in the interior space of the container and a second receiving device proximately exterior the container, wherein the power levels of the messages transmitted by said RFID devices received by each of said receiving devices is indicative of whether the container is closed, is not closed, has been closed, or has been not closed, or any combination thereof. 10. The system of claim 1 wherein said receiving device further comprises a transmitter for transmitting the messages received from said RFID device interior the container and a signal representative of the received signal strength of the received messages, said system further comprising: a processor for receiving the messages transmitted by said receiving device and for processing the information therein for determining a condition of the container, including whether the container is closed, is not closed, has been closed, or has been not closed, or any combination thereof, or for determining the location of said RFID device, and for providing an indication of any one or combination of the foregoing. 11. The system of claim 10 further comprising an object RFID device associated with an object that is related to a given container by a predetermined relationship, wherein said processor includes a database relating the RFID device associated with the given container and the object RFID device. 12. The system of claim 11 wherein the predetermined relationship includes proximity of the object and the given container, or absence of proximity of the object and the given container, or both, and wherein said processor provides an indication of whether the object and the given container are in the predetermined relationship. 13. The system of claim 11 wherein the object includes a carrier carrying the given container, or a vehicle carrying the given container, or a driver or operator of a carrier carrying the given container, or a driver or operator of a vehicle carrying the given container, or an inspector of the given container, or a maintenance or service worker for the given container, or a person not authorized to be proximate the given container, or any combination of the foregoing. 14. A method for monitoring a container having at least one RFID device interior thereto, said method comprising: providing an RFID device interior to a closable container, the RFID device periodically transmitting messages; wherein each of the messages includes information uniquely identifying the RFID device, and wherein messages that are transmitted when the closable container is closed are substantially attenuated by the closable container, and wherein messages that are transmitted when the closable container is not closed are not substantially attenuated by the closable container; receiving messages transmitted by the RFID device interior the closable container by a receiving device exterior the closable container; whereby messages that are transmitted when the closable container is closed are not received by the receiving device or are received with certain respective power levels and wherein messages that are transmitted when the closable container is not closed are received by the receiving device with different respective power levels; and determining from the power levels of messages received from the RFID device whether the closable container is closed, is not closed, has been closed, or has been not closed, or any combination thereof, whereby an opening of and/or tampering with the closable container may be detected. 15. The method of claim 14 further comprising representing the power levels of the messages received by said receiving device exterior the closable container by an indication of received signal strength. 16. The method of claim 14 wherein said determining includes processing a representation of received signal strength of the messages received for providing an indication of whether the closable container is closed, is not closed, has been closed, or has been not closed, or any combination thereof, wherein the received signal strength of the messages received when the closable container is closed is less than the received signal strength of the messages received when the closable container is not closed. 17. The method of claim 14: wherein said periodically transmitting messages comprises periodically transmitting messages at different power levels from the RFID device interior to the closable container, wherein each of the messages includes information uniquely identifying the RFID device and information representing the power level at which the message is transmitted; and wherein said determining from the power level of messages received comprises determining from the power level information of messages received from the RFID device whether the closable container is closed, is not closed, has been closed, or has been not closed, or any combination thereof. 18. The method of claim 14 further comprising: representing the power levels of the messages received by said receiving device exterior the closable container by an indication of received signal strength; wherein each of the messages includes information representative of the power level at which the message is transmitted; and wherein said determining from the power levels of messages received includes determining from the indication of received signal strength, or from the information representative of the power level of messages received, or determining from the indication of received signal strength and from the information representative of the power level of messages received, whether the closable container is closed, is not closed, has been closed, or has been not closed, or any combination thereof. 19. The method of claim 14 further comprising: sensing a thing and/or a condition at or proximate the RFID device, and transmitting data produced by said sensing in a message transmitted by the RFID device, or storing data produced by said sensing in the RFID device, or both. 20. The method of claim 19 wherein said transmitting data produced by said sensing comprises transmitting at a present time, or at a future time, or at a predetermined time, or periodically, or in response to an interrogation signal, or at a programmable power level, or any combination of the foregoing. 21. The method of claim 19 wherein the thing and/or condition sensed by said sensing includes an environmental condition, or temperature, or pressure, or position, or location, or motion, or acceleration, or impact, or distance, or inertial information, or magnetic field, or electrical continuity, or altitude, or a physical parameter, or moisture, or humidity, or a chemical, or a medical parameter, or a biological substance and/or agent, or radioactivity, or optical, or light, or infrared, or an image, or an electromagnetic field, or any combination of the foregoing. 22. The method of claim 14 wherein: said periodically transmitting messages comprises periodically transmitting messages from each of two RFID devices at different locations interior to the closable container; and wherein: said receiving messages transmitted by the RFID device comprises receiving messages transmitted by the two RFID devices via two receiving devices at different locations exterior the closable container; said method further comprising: determining from the power levels of messages transmitted by the two RFID devices that are received by the first and second receiving devices whether the closable container is closed, is not closed, has been closed, or has been not closed, or any combination thereof. 23. The method of claim 14 further comprising: relaying the received messages transmitted periodically by the RFID device, wherein at least some substantially attenuated messages may not be received; and processing the relayed messages for monitoring the RFID device, said processing comprising: determining the location of the RFID device from the relayed messages, or determining from the power levels of messages from the RFID device that are relayed whether the closable container is closed, is not closed, has been closed, or has been not closed, or any combination thereof, or both of the foregoing. 24. The method of claim 23 wherein said determining the location of the RFID device from the relayed messages comprises: defining a radius value representative of the power level of each message from the RFID device that was relayed; and for each RFID device, determining the intersection of respective geometric shapes having the defined radius values for locating that particular RFID device in the intersection. 25. The method of claim 14 further comprising relating an object RFID device associated with an object to a given closable container by a predetermined relationship, and storing in a database information relating the RFID device interior the given closable container and the object RFID device. 26. The method of claim 25 wherein the predetermined relationship includes proximity of the object and the given closable container, or absence of proximity of the object and the given closable container, or both, and further comprising providing an indication of whether the object and the given closable container are in the predetermined relationship. 27. The method of claim 25 wherein the object includes a carrier carrying the given closable container, or a vehicle carrying the given closable container, or a driver or operator of a carrier carrying the given closable container, or a driver or operator of a vehicle carrying the given closable container, or an inspector of the given closable container, or a maintenance or service worker for the given closable container, or a person not authorized to be proximate the given closable container, or any combination of the foregoing. 28. A method for monitoring one or more objects each having an RFID device associated therewith, said method comprising: transmitting messages from the RFID device at different power levels or at a defined power level or at different defined power levels, wherein each of the messages includes information uniquely identifying the RFID device; relaying the messages transmitted by each RFID device and information representative of the power level thereof; and processing the relayed messages for determining the location of each RFID device, said processing comprising: processing the unique identifying information and the information representative of the power level of each relayed message for associating the relayed messages from each RFID device and the power level of the messages from each RFID device, and selecting the relayed messages from a particular RFID device that are at the power level that produces at least two corresponding messages relayed by at least two different relaying devices for determining the location of that particular RFID device and its associated object therefrom. 29. The method of claim 28 wherein the information representative of the power level of the messages transmitted by each RFID device includes: a power level code included in each message transmitted by the RFID device, which power level code is indicative of the power level at which that particular message is transmitted; or information generated by a receiver that is representative of the signal strength of the received signal containing the message received by that receiver; or a power level code included in each message transmitted by the RFID device, which power level code is indicative of the power level at which that particular message is transmitted, and information generated by a receiver that is representative of the signal strength of the received signal containing the message received by that receiver. 30. The method of claim 29 wherein the object is closable and the RFID device is therein, wherein said processing includes: determining from the power level code, the information that is representative of the signal strength of the received signal containing the message, or both, whether the object is closed, is not closed, has been closed, or has been not closed, or any combination thereof. 31. The method of claim 29 wherein said processing includes: defining from the power level code, the information that is representative of the signal strength of the received signal containing the message, or both, a radius value representative of the power level of each relayed message; and for each RFID device, determining the intersection of respective geometric shapes having the defined radius values for locating that particular RFID device in the intersection. 32. The method of claim 31 wherein said determining the intersection of respective geometric shapes having the defined radius values further comprises: if the respective geometric shapes having the defined radius values do not intersect, then proportionately increasing the radius values thereof until the respective geometric shapes do intersect. 33. The method of claim 31 wherein said determining the intersection of respective geometric shapes having the defined radius values comprises: determining the intersection of first and second ones of the respective geometric shapes having defined radius values; determining the intersection of a third one of the respective geometric shapes having defined radius value with the intersection of the first and second ones thereof; and repeating the immediately preceding determining step for each additional one of the respective geometric shapes, if any, until all of the respective geometric shapes for the particular RFID device are used. 34. The method of claim 28 wherein said relaying further comprises associating identification information, or location information, or date/time information, or any combination of the foregoing, with the messages relayed. 35. The method of claim 34 wherein said processing the relayed messages further includes processing the identification information, or the location information, or the date/time information, or any combination of the foregoing, for determining the location of a particular RFID device. 36. The method of claim 28 wherein said transmitting messages comprises transmitting continuously, or transmitting messages periodically at regular or irregular intervals of time, or transmitting messages at programmable intervals, or transmitting messages at programmable power levels, or transmitting messages responsive to an interrogation signal, or transmitting messages until receipt of an acknowledgment signal, or any combination of the foregoing. 37. The method of claim 28 wherein said processing the relayed messages comprises storing in records in a database at least the information contained in the relayed messages and the location information determined for each RFID device from which a relayed message has been received, said method further comprising: accessing information stored in records of the database via wire, or cable, or telephone, or a radio link, or a network, or the Internet, or an intranet, or a local area network, or a wide area network, or a wireless network, or an ad hoc network, or a satellite, or e-mail, or a computer, or a laptop computer, or a personal digital assistant device, or a Blackberry-enabled device, or a Wi-Fi-enabled device, or a cell phone, or a WAP-enabled cell phone, or a pager, or any combination of the foregoing. 38. A method for monitoring or locating, or for monitoring and locating, an object having an RFID device associated therewith, said method comprising: transmitting messages at a given power level from the RFID device, wherein each of the messages includes information uniquely identifying the RFID device and information representing the power level at which the message is transmitted; receiving the messages transmitted by the RFID device; and determining a signal strength of received signals containing the received messages transmitted by the RFID device; determining the unique identifying information and the power level information included in each received message; and processing the determined signal strength, the determined power level information, or both, for determining the location of the RFID device or for monitoring the RFID device, or for both determining the location of the RFID device and for monitoring the RFID device, wherein said processing includes comparing relative values of the power level information and the determined signal strength to determine an attenuation, wherein the attenuation is representative of a distance between the RFID device and a receiver of the received messages, a condition of a container in which the RFID device is disposed, or both, whereby the location and/or condition of the object with which the RFID device is associated may be determined and/or monitored. 39. The method of claim 38 wherein the condition includes an open condition, a closed condition, a change from an open condition, a change from a closed condition, an environmental condition, a temperature, a pressure, a position, a location, a motion, acceleration, an impact, a distance, inertial information, a magnetic field, electrical continuity, an altitude, a physical parameter, moisture, humidity, a chemical, a medical parameter, a biological substance and/or agent, radioactivity, an optical condition, light, infrared, an image, an electromagnetic field, or any combination of the foregoing.