CA2472809A1 - Rfid sensor tag with on-board processing - Google Patents
Rfid sensor tag with on-board processing Download PDFInfo
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- CA2472809A1 CA2472809A1 CA002472809A CA2472809A CA2472809A1 CA 2472809 A1 CA2472809 A1 CA 2472809A1 CA 002472809 A CA002472809 A CA 002472809A CA 2472809 A CA2472809 A CA 2472809A CA 2472809 A1 CA2472809 A1 CA 2472809A1
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- tag
- cpu
- block
- processed data
- reader
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D9/00—Recording measured values
- G01D9/005—Solid-state data loggers
Abstract
A tag for attachment to a container or similar package being shipped and/or stored comprises: a central processing unit (CPU); a timer; a crystal resonator connected to the timer; a measuring block connected to the CPU; one or more sensors connected to the measuring block; a communications block connected to the CPU;
a feedback block connected to the CPU; and an EEPROM connected to the CPU. In use a sensor senses environmental changes to which the package is exposed during shipment and/or storage. The CPU processes signals received from the sensor and stores processed data for later retrieval. When required the CPU communicates such processed data via the communications block to a party interested in such processed data.
a feedback block connected to the CPU; and an EEPROM connected to the CPU. In use a sensor senses environmental changes to which the package is exposed during shipment and/or storage. The CPU processes signals received from the sensor and stores processed data for later retrieval. When required the CPU communicates such processed data via the communications block to a party interested in such processed data.
Description
RFID SENSOR TAG WITH ON-BOARD PROCESSING
The present invention relates to sensor tags used to monitor environmental conditions with goods in transit or in storage, BACKGROUND OF THE INVENTION
Sensor tags which are capable of monitoring environmental conditions associated with goods in transit and/or in storage are known. Such tags might monitor, for example, the temperature conditions surrounding a shipment of edible produce, such as fruits or vegetables, as they travel from the source thereof to the ultimate vendor of such produce, often in another country. The tag, provided with a suitable temperature sensor, a battery and a suitable electronic chip, can ascertain the actual temperature conditions surrounding the produce at regular intervals and whenever the sensed temperature falls outside a predetermined range (either above or below the range limits). The actual temperature and the time are recorded in the tag's memory. At the end of the trip the memory data can be downloaded for use by whoever has interest in the data. The data can then be analyzed, with the results of the analysis perhaps determining whether the produce is still edible, whether the normal shelf life thereof is still appropriate, or whether changes in shipping procedures need to be made.
Such tags as described above are discussed in commonly owned Canadian Patent Applications Nos. 2,383,049 and 2,387,106 of April 23 and May 21, 2002 respectively. A detriment of such tags is the need to have a sufficiently large memory to accommodate the sensed data, and in particular to accommodate a significant number of excursions outside the specified range. If there are very few excursions then, of course, there are no memory problems; however, if the tag is to be contained in or on the package of produce for a long time, say several weeks, then the problem of memory overload could become significant. If such tags are to be used on a regular basis to improve the overall quality of goods delivered to the eventual consumer then the cost of such tags must not be prohibitive, which means that the most efficient use _ ____ ~ _~,,.,w u~.~~ _ . r,..9~. ~m~.M.a_ n _ ..,~ _. _ __ ___..____ _ ~__ F
of the processing capabilities of the tags must be made.
SUMMARY OF THE INVENTION
The present invention overcomes problems associated with existing sensor tags by providing such tags with the capability of processing sensed data on board the tags such that usable data can be downloaded for immediate use and so that the memoiry requirements for the tags can be minimized. By processing the sensed information tin board the tag it is possible to retain only the information that is deemed relevant to the purpose of the tag, i.e. information that relates to sensed conditions that exceed the predetermined threshold values and which are programmed into the tag before it is placed with the goods to be monitored. The minute-by-minute sensed data can be discarded, with only the significant relevant results being retained. Whenever the data is accessed, as for example by a remote reader, an immediate decision can be made as to whether the data indicates a serious issue with the quality of the goods. In the past, as with existing tags, it was necessary to download the raw data as accumulated in the tag's memory, to process that data after downloading, and to then make a decision based on the processed data. With the present invention the off-site processing step is eliminated and pertinent decisions can be made much sooner.
For example, when the sensor detects and processes temperature information collected during a shipment of fresh produce from one country to another it would be possible to immediately ascertain whether the shipment should be quarantined because of the shipping experience, perhaps because of extended exposure to excessive temperatures en route.
A sensor in accordance with the present invention can be used to sense more than just temperature. It could be suitably designed to sense one or more of a plurality of environmental conditions encountered during shipping or in storage including, but not limited to, vibration, noise, humidity, radiation and light. It can analyze the output of any type of sensor that can be connected to it. It can also use different (non-silicone/electronic) methods of analyzing temperature or environmental conditions via environment-sensitive specific bioenzymatic or chemical polymer-based ~. _ ~ ... _ .. _. .~._ . ... m~.... ~ ..~W . .~ ~,e.~~~ .. ,. z , ..~~ _~ __ .. _.__. . _. _._~~ . ,~,~~. ~ .___ __ ø __._mA.
and other inks or "blobs" of material which can be used to sense and/or memorize accumulations of events and report back. This could be done passively, so that either the tag itself or the RFID reader system could determine the amount of accumulated effect based on the state-change of such materials. The material itself would be inserted in the antenna circuit, for example, and essentially change the transmissive properties of the tag, thereby indicating the accumulated and/or current environmental exposure to which the specific compound is and/or has been exposed.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described with reference to the attached drawings wherein Figure 1 is a schematic block diagram illustrating the major components of a tag in accordance with this invention.
Figure 2A is a schematic representation of the memory block seen in Figure 1.
Figure 2B is a typical graph of voltage against time for the measuring block.
Figure 3A is a schematic representation of the communication block seen in Figure 1.
Figure 3B shows graphically typical tag and reader antenna waveforms.
Figure 4 is a schematic representation of the feedback block seen in Figure 1.
Figure 5 is a more detailed illustration of the EEPROM block of Figure 1.
Figure 6 is a flow chart showing the basic operation of the tag of the present invention.
Figure 7 is a flow chart showing the procedure for tag/reader communications.
Figure 8 shows schematically the form of a message transmitted by the tag.
Figure 9 shows schematically how a "dead" tag can be accessed by a reader.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference initially to Figure 1 the major components and the connections therebetween are illustrated. Thus, a tag in accordance with this invention includes a programmable CPU connected directly to a clock module or timer controlled by a simple ...., .P .. ... ..,.. _.._.... ~._~..~~._ .~.y. m x_~,~ ._w. , as ~~,""~r.~
_.... p __n.....~.
watch crystal resonator. Such resonators provide a high degree of stability of resonating frequency under changeable environmental conditions and are suited to reliable mass production. The CPU is connected in parallel to a measuring block a communication block, a feedback block and an EEPROM. The measuring block 16 is connected to one or more sensors especially adapted to sense the condition or characteristic of interest, such as temperature.
The circuitry for the measuring block is illustrated in Figure 2A, for a plurality of associated sensors. In the illustrated version there are several temperature sensitive sensors provided on the tag, each sensor having a particular temperature range associated therewith. The CPU is set up to measure Rnsensor at regular, equidistant intervals. While the sensors are disconnected from the CPU the capacitor Cmeasure is charged to its full capacity (SO = OFF, S1 = ON). After the capacitor has been charged it is disconnected from the power source (SO = OFF, S1 = OFF). When a sensor Rnsensor is connected to the CPU the capacitor Cmeasur~ Starts to discharge (SO = OFF, S1 = ON).
The CPU measures Tmeasure namely the period during which the capacitor discharges from the logic 1 to logic 0 level. Since Tmeasure is proportional to a time constant (Rnse~,so~
* Cmeasure) the CPU will calculate the Rnsensor and accordingly the temperature. The stages of the measuring cycle as outlined above are illustrated in Figure 2B.
Figure 3A illustrates the communication block of the RFID tag of this invention.
This is the part of the tag that communicates with the RF reader used in conjunction with the tag. When a tag enters the RF field a voltage is induced in the tag antenna and through the diode it is detected in the processor. This is the signal to the tag to start sending messages to the reader. This is accomplished by opening and closing the switch So which will change the voltage amplitude on the tag antenna. The changes in the voltage amplitude on the tag antenna will afFect the voltage at the reader antenna. By monitoring the changes in the reader antenna voltage (due to the tag's modulation data), the data from the tag can be reconstructed at the reader.
Figure 3B illustrates representative waveforms as generated by the tag and received at the reader antenna for a typical signal.
Figure 4 illustrates schematically the feedback block which serves the purpose ,m.~..~..z~,mm~ .. ~.~~ .~w_ ~ ~, ~.a_.~,..~s_~~n of communicating information from the tag to a user of the tag. The feedback block has a LED diode which will blink in a certain sequence depending on which mode the tag may be in. In place of the LED diode, providing a visual signal to the user, a miniature speaker could be used to provide the user with an audio signal to indicate the tag mode. The nature of the signals imparted to the user will be described hereinbelow in the description of tag operation.
Figure 5 shows a more detailed illustration of the EEPROM block shown in Figure 1.
The basic operation steps associated with the RFID tag of the present invention are set forth in the flow chart of Figure 6. It is presumed that a customer/user of the tag has obtained a tag from the supplier thereof. The tag on purchase is not active.
It is in a dormant or "sleep" mode. However, the tag was prepared by the supplier to operate in accordance with the customer's specifications, that is it has been programmed to respond to changes in a sensed characteristic relating to the environment in which the tag is to be used, in this case with respect to temperature fluctuations beyond a predetermined range.
To active the tag the user first of all will push the STOP/START button on the tag. The LED light of the feedback block should blink once, indicating that the tag has been turned on. If the user is unsure that he saw the light blink then the pushing step can be repeated. Once the light has blinked once the tag is in its "packaging"
mode, which means that it is activated but it will not record any events for a predetermined period of time. For example, there could be a delay of about 16 minutes during which time the user can place the tag in a package or shipment of material. After the predetermined period of time has expired the tag will start processing signals received from the sensor associated therewith and recording any excursions from the set range as programmed into the tag.
Once the shipment has reached its destination the user will push the START/STOP button to stop the tag. The LED light should blink twice indicating a "stop" condition. The pushing step can be repeated if the user is unsure whether the light blinked twice. If the temperatures sensed during the shipment crossed the excursion limit as programmed initially into the tag, such that the acceptable temperature range was exceeded, the LED light will blink for a predetermined period of time, say 16 minutes, so that the user can download the relevant data. Tf there were no excursions during the shipment the LED light will not blink.
Figure 7illustrates a flow chart which details the steps when the tag interfaces with a reader. When the tag has been turned off as indicated above it enters a standby mode, awaiting a signal from the reader. If the signal received from the reader is in a proper sequence the tag will enter its Receiving mode, execute the command imparted to it by the reader and thereafter return to its Sleep or Sensor measuring mode. If the signal is not in the proper sequence the tag immediately enters its Sleep/Sensor measuring mode. When the signal is in the proper sequence the reader can receive processed data from the tag and it, in turn, can provide the tag with new program instructions if necessary.
The format of a message transmitted from the tag to the reader will be as shown in Figure 8. There it is seen that the message will have seven components, A
through G. Component A identifies the version of the tag and component B identifies the protocol version for that tag. Component C identifies the number of data packets that will be transmitted. Component D is the actual packet number being transmitted and component E will be the data associated with that packet number.
In the event that the tag battery dies during the shipment it is still possible to obtain data from the tag. Figure 9 shows schematically how this is achieved.
The required energy can be extracted from the LF field provided by the reader. The voltage induced on the 13,56 MHz antenna will be transmitted to the CPU so that the data can be transmitted to the reader.
The tag of the present invention never generates RF energy itself, so it is 100%
safe to be housed within a shipping container, no matter what the contents might be.
It is even safe for use with explosives that require monitoring during shipment when temperature or humidity might be a concern with respect to the effectiveness thereof.
The tag still can be scanned remotely by a reader, even through the wall of the container if necessary.
The present invention relates to sensor tags used to monitor environmental conditions with goods in transit or in storage, BACKGROUND OF THE INVENTION
Sensor tags which are capable of monitoring environmental conditions associated with goods in transit and/or in storage are known. Such tags might monitor, for example, the temperature conditions surrounding a shipment of edible produce, such as fruits or vegetables, as they travel from the source thereof to the ultimate vendor of such produce, often in another country. The tag, provided with a suitable temperature sensor, a battery and a suitable electronic chip, can ascertain the actual temperature conditions surrounding the produce at regular intervals and whenever the sensed temperature falls outside a predetermined range (either above or below the range limits). The actual temperature and the time are recorded in the tag's memory. At the end of the trip the memory data can be downloaded for use by whoever has interest in the data. The data can then be analyzed, with the results of the analysis perhaps determining whether the produce is still edible, whether the normal shelf life thereof is still appropriate, or whether changes in shipping procedures need to be made.
Such tags as described above are discussed in commonly owned Canadian Patent Applications Nos. 2,383,049 and 2,387,106 of April 23 and May 21, 2002 respectively. A detriment of such tags is the need to have a sufficiently large memory to accommodate the sensed data, and in particular to accommodate a significant number of excursions outside the specified range. If there are very few excursions then, of course, there are no memory problems; however, if the tag is to be contained in or on the package of produce for a long time, say several weeks, then the problem of memory overload could become significant. If such tags are to be used on a regular basis to improve the overall quality of goods delivered to the eventual consumer then the cost of such tags must not be prohibitive, which means that the most efficient use _ ____ ~ _~,,.,w u~.~~ _ . r,..9~. ~m~.M.a_ n _ ..,~ _. _ __ ___..____ _ ~__ F
of the processing capabilities of the tags must be made.
SUMMARY OF THE INVENTION
The present invention overcomes problems associated with existing sensor tags by providing such tags with the capability of processing sensed data on board the tags such that usable data can be downloaded for immediate use and so that the memoiry requirements for the tags can be minimized. By processing the sensed information tin board the tag it is possible to retain only the information that is deemed relevant to the purpose of the tag, i.e. information that relates to sensed conditions that exceed the predetermined threshold values and which are programmed into the tag before it is placed with the goods to be monitored. The minute-by-minute sensed data can be discarded, with only the significant relevant results being retained. Whenever the data is accessed, as for example by a remote reader, an immediate decision can be made as to whether the data indicates a serious issue with the quality of the goods. In the past, as with existing tags, it was necessary to download the raw data as accumulated in the tag's memory, to process that data after downloading, and to then make a decision based on the processed data. With the present invention the off-site processing step is eliminated and pertinent decisions can be made much sooner.
For example, when the sensor detects and processes temperature information collected during a shipment of fresh produce from one country to another it would be possible to immediately ascertain whether the shipment should be quarantined because of the shipping experience, perhaps because of extended exposure to excessive temperatures en route.
A sensor in accordance with the present invention can be used to sense more than just temperature. It could be suitably designed to sense one or more of a plurality of environmental conditions encountered during shipping or in storage including, but not limited to, vibration, noise, humidity, radiation and light. It can analyze the output of any type of sensor that can be connected to it. It can also use different (non-silicone/electronic) methods of analyzing temperature or environmental conditions via environment-sensitive specific bioenzymatic or chemical polymer-based ~. _ ~ ... _ .. _. .~._ . ... m~.... ~ ..~W . .~ ~,e.~~~ .. ,. z , ..~~ _~ __ .. _.__. . _. _._~~ . ,~,~~. ~ .___ __ ø __._mA.
and other inks or "blobs" of material which can be used to sense and/or memorize accumulations of events and report back. This could be done passively, so that either the tag itself or the RFID reader system could determine the amount of accumulated effect based on the state-change of such materials. The material itself would be inserted in the antenna circuit, for example, and essentially change the transmissive properties of the tag, thereby indicating the accumulated and/or current environmental exposure to which the specific compound is and/or has been exposed.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described with reference to the attached drawings wherein Figure 1 is a schematic block diagram illustrating the major components of a tag in accordance with this invention.
Figure 2A is a schematic representation of the memory block seen in Figure 1.
Figure 2B is a typical graph of voltage against time for the measuring block.
Figure 3A is a schematic representation of the communication block seen in Figure 1.
Figure 3B shows graphically typical tag and reader antenna waveforms.
Figure 4 is a schematic representation of the feedback block seen in Figure 1.
Figure 5 is a more detailed illustration of the EEPROM block of Figure 1.
Figure 6 is a flow chart showing the basic operation of the tag of the present invention.
Figure 7 is a flow chart showing the procedure for tag/reader communications.
Figure 8 shows schematically the form of a message transmitted by the tag.
Figure 9 shows schematically how a "dead" tag can be accessed by a reader.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference initially to Figure 1 the major components and the connections therebetween are illustrated. Thus, a tag in accordance with this invention includes a programmable CPU connected directly to a clock module or timer controlled by a simple ...., .P .. ... ..,.. _.._.... ~._~..~~._ .~.y. m x_~,~ ._w. , as ~~,""~r.~
_.... p __n.....~.
watch crystal resonator. Such resonators provide a high degree of stability of resonating frequency under changeable environmental conditions and are suited to reliable mass production. The CPU is connected in parallel to a measuring block a communication block, a feedback block and an EEPROM. The measuring block 16 is connected to one or more sensors especially adapted to sense the condition or characteristic of interest, such as temperature.
The circuitry for the measuring block is illustrated in Figure 2A, for a plurality of associated sensors. In the illustrated version there are several temperature sensitive sensors provided on the tag, each sensor having a particular temperature range associated therewith. The CPU is set up to measure Rnsensor at regular, equidistant intervals. While the sensors are disconnected from the CPU the capacitor Cmeasure is charged to its full capacity (SO = OFF, S1 = ON). After the capacitor has been charged it is disconnected from the power source (SO = OFF, S1 = OFF). When a sensor Rnsensor is connected to the CPU the capacitor Cmeasur~ Starts to discharge (SO = OFF, S1 = ON).
The CPU measures Tmeasure namely the period during which the capacitor discharges from the logic 1 to logic 0 level. Since Tmeasure is proportional to a time constant (Rnse~,so~
* Cmeasure) the CPU will calculate the Rnsensor and accordingly the temperature. The stages of the measuring cycle as outlined above are illustrated in Figure 2B.
Figure 3A illustrates the communication block of the RFID tag of this invention.
This is the part of the tag that communicates with the RF reader used in conjunction with the tag. When a tag enters the RF field a voltage is induced in the tag antenna and through the diode it is detected in the processor. This is the signal to the tag to start sending messages to the reader. This is accomplished by opening and closing the switch So which will change the voltage amplitude on the tag antenna. The changes in the voltage amplitude on the tag antenna will afFect the voltage at the reader antenna. By monitoring the changes in the reader antenna voltage (due to the tag's modulation data), the data from the tag can be reconstructed at the reader.
Figure 3B illustrates representative waveforms as generated by the tag and received at the reader antenna for a typical signal.
Figure 4 illustrates schematically the feedback block which serves the purpose ,m.~..~..z~,mm~ .. ~.~~ .~w_ ~ ~, ~.a_.~,..~s_~~n of communicating information from the tag to a user of the tag. The feedback block has a LED diode which will blink in a certain sequence depending on which mode the tag may be in. In place of the LED diode, providing a visual signal to the user, a miniature speaker could be used to provide the user with an audio signal to indicate the tag mode. The nature of the signals imparted to the user will be described hereinbelow in the description of tag operation.
Figure 5 shows a more detailed illustration of the EEPROM block shown in Figure 1.
The basic operation steps associated with the RFID tag of the present invention are set forth in the flow chart of Figure 6. It is presumed that a customer/user of the tag has obtained a tag from the supplier thereof. The tag on purchase is not active.
It is in a dormant or "sleep" mode. However, the tag was prepared by the supplier to operate in accordance with the customer's specifications, that is it has been programmed to respond to changes in a sensed characteristic relating to the environment in which the tag is to be used, in this case with respect to temperature fluctuations beyond a predetermined range.
To active the tag the user first of all will push the STOP/START button on the tag. The LED light of the feedback block should blink once, indicating that the tag has been turned on. If the user is unsure that he saw the light blink then the pushing step can be repeated. Once the light has blinked once the tag is in its "packaging"
mode, which means that it is activated but it will not record any events for a predetermined period of time. For example, there could be a delay of about 16 minutes during which time the user can place the tag in a package or shipment of material. After the predetermined period of time has expired the tag will start processing signals received from the sensor associated therewith and recording any excursions from the set range as programmed into the tag.
Once the shipment has reached its destination the user will push the START/STOP button to stop the tag. The LED light should blink twice indicating a "stop" condition. The pushing step can be repeated if the user is unsure whether the light blinked twice. If the temperatures sensed during the shipment crossed the excursion limit as programmed initially into the tag, such that the acceptable temperature range was exceeded, the LED light will blink for a predetermined period of time, say 16 minutes, so that the user can download the relevant data. Tf there were no excursions during the shipment the LED light will not blink.
Figure 7illustrates a flow chart which details the steps when the tag interfaces with a reader. When the tag has been turned off as indicated above it enters a standby mode, awaiting a signal from the reader. If the signal received from the reader is in a proper sequence the tag will enter its Receiving mode, execute the command imparted to it by the reader and thereafter return to its Sleep or Sensor measuring mode. If the signal is not in the proper sequence the tag immediately enters its Sleep/Sensor measuring mode. When the signal is in the proper sequence the reader can receive processed data from the tag and it, in turn, can provide the tag with new program instructions if necessary.
The format of a message transmitted from the tag to the reader will be as shown in Figure 8. There it is seen that the message will have seven components, A
through G. Component A identifies the version of the tag and component B identifies the protocol version for that tag. Component C identifies the number of data packets that will be transmitted. Component D is the actual packet number being transmitted and component E will be the data associated with that packet number.
In the event that the tag battery dies during the shipment it is still possible to obtain data from the tag. Figure 9 shows schematically how this is achieved.
The required energy can be extracted from the LF field provided by the reader. The voltage induced on the 13,56 MHz antenna will be transmitted to the CPU so that the data can be transmitted to the reader.
The tag of the present invention never generates RF energy itself, so it is 100%
safe to be housed within a shipping container, no matter what the contents might be.
It is even safe for use with explosives that require monitoring during shipment when temperature or humidity might be a concern with respect to the effectiveness thereof.
The tag still can be scanned remotely by a reader, even through the wall of the container if necessary.
The tag of this invention operates by storing and presenting data in the form of temperature histograms, with variable temperature resolution. Each histogram can have up to 28 bins, for example there could be temperature bins for +1°C, +2°C, +3°C, +4°C, +5°C, +6°C and +7°C if those represent the temperatures of most concern with respect to a predetermined temperature limit. When in the monitoring mode the chip will know for how long the device was exposed to each of those temperatures. The rest of the temperature range would be covered by temperature bins with much less resolution, for example -10°C to -5°C, -5°C to 0°C, +20°C to +35°C, etc. The tag will be able to determine for how long it was exposed to temperatures within each of these ranges. Whenever the temperature crosses any of the upper or lower limits of a range there will be a time stamp created, defining an excursion point.
The present invention utilizes a unique method for keeping track of time, in comparison to traditional methods. A traditional method of keeping track of real time events is to:
a) provide a device which increments the local time count value N ,°~al every Tincr local units of time;
b) synchronize the timing device with a reference timing device, say at a particular moment with a value of Tsyn~ units of reference time. The local time count N=0 at this moment. The reference time Tsync ° Tin~r_ref * Nref.
c) keep track of N ,~a, values for each event about which a recorded time is required; and d) calculate the event time at each moment as:
Tevent - Tsync +Tincr_local * N local_(event) There are several problems associated with such a method; in particular T~n~r local must be stable under different environmental conditions and the value of Tin~r_lo~al must be as close as possible to the value of T;n~r rer. It is very difficult to achieve these requirements with mass production. Electronic time keeping devices usually use crystal resonators which give a high stability of resonating frequency under changeable environmental conditions. This is a solution to the first problem.
However, i it is very complicated to ensure that T;n~~ ma; ' T~ncr ref° The process involves high precision production techniques for manufacture of the crystals, as well as calibration of each individual resonator.
With the present invention accurate time keeping is simplified and improved.
The present device increments the local time count value T ,~, every T;n°~ ,o,~, units of time. At the moment of initial synchronization values of Tsynaand N ,o~an are recorded.
At the moment of final synchronization values of TSync2 and N~;°~a;2 are recorded. Then, Tevent - ~Tsync2 ~ Tsyncl~~~N ~ocal2 N locallJ * N local_event°
As with the traditional method T;ncr ,~ca; must be stable; however, it could be much different from T;n~r ref which means in turn that it is not necessary to use expensive, highly accurate crystals. On the other hand, it is necessary to have accurate values of T~,n~i and Tsynca . which means that the synchronization device, the reader, must have be calibrated for time or have access to an atomic clock (as for example through the Internet). Mass produced tags in accordance with the present invention will be of lower cost in comparison to tags which provide time keeping in accordance with traditional methods, since it is only necessary to have the synchronizing devices accurate. In this case the reader will provide the required accurate timing, it being noted that the reader will be a low volume production device in comparison to the tag, which will be a high volume production device.
In summary of the foregoing the present invention provides an inexpensive tag that can be included in any type of shipping container, with any type of product, and which will monitor temperature excursions with respect to predetermined limits or ranges. The tag processes data on board, using a unique time keeping process and requires very little memory to retain the processed data. The data can be downloaded using RFID technology to a reader should there be any excursions during shipment or storage. The tag uses a simple visual indicator to alert the user to any excursions once the tag has been turned off at its destination. The temperature sensor is of the digital type and can measure temperature in 1°C increments. It will have an accuracy of t1°C from -20°C to +30°C. It can support one additional sensor, to sense for example humidity or vibration. It utilizes a programmable status LED warning light.
It records a long-term temperature histogram, with each histogram having up to bins. Each such bin can store up to 65,536 time points and it can record up to excursions when the sensed temperature leaves the specified range. It provides for real-time, on-board data analysis. It communicates with its host (the reader) using proprietary RF communication protocol. It has a unique 32-bit ID number, assuring absolute traceability because no two tags will be alike. It provides a 1 minute time resolution of recorded events and it provides an accuracy of timing reported of ~5 minutes if the data is scanned within 60 days. The battery operating voltage is 2.5V
to 3.5V and the maximum storage time in the non-active mode is 12 months. The maximum operating time in the active mode is 6 months. The operating temperature ranges are -30°C to +60°C in the non-active mode and -20°C to +30°C in the active mode. Data can be retrieved for a period of up to 7 years. The RF reader range is 5cm or greater and two tags could be read at the same time without any fear of the transmitted data being compromised. The tag's internal clock is accurate to +2 minutes/month. The tag is capable of processing and storing the data in protected logic file format (.Idf). The semi-flexible shape of the tag is resistant to temperature, humidity, vibration and shock.
The foregoing has described a unique tag that can be used on any type of container, pallet, bag, package, etc. to monitor and report on environmental changes experienced by the package during shipment and/or storage, providing useful information in a reliable, inexpensive manner to a user. The significant features of the tag have been described, but it is understood that alterations and/or additions to those features could be accomplished by a skilled person without departing from the spirit of the invention.
g - _ r _ _ .r.~.rr..~______ _
The present invention utilizes a unique method for keeping track of time, in comparison to traditional methods. A traditional method of keeping track of real time events is to:
a) provide a device which increments the local time count value N ,°~al every Tincr local units of time;
b) synchronize the timing device with a reference timing device, say at a particular moment with a value of Tsyn~ units of reference time. The local time count N=0 at this moment. The reference time Tsync ° Tin~r_ref * Nref.
c) keep track of N ,~a, values for each event about which a recorded time is required; and d) calculate the event time at each moment as:
Tevent - Tsync +Tincr_local * N local_(event) There are several problems associated with such a method; in particular T~n~r local must be stable under different environmental conditions and the value of Tin~r_lo~al must be as close as possible to the value of T;n~r rer. It is very difficult to achieve these requirements with mass production. Electronic time keeping devices usually use crystal resonators which give a high stability of resonating frequency under changeable environmental conditions. This is a solution to the first problem.
However, i it is very complicated to ensure that T;n~~ ma; ' T~ncr ref° The process involves high precision production techniques for manufacture of the crystals, as well as calibration of each individual resonator.
With the present invention accurate time keeping is simplified and improved.
The present device increments the local time count value T ,~, every T;n°~ ,o,~, units of time. At the moment of initial synchronization values of Tsynaand N ,o~an are recorded.
At the moment of final synchronization values of TSync2 and N~;°~a;2 are recorded. Then, Tevent - ~Tsync2 ~ Tsyncl~~~N ~ocal2 N locallJ * N local_event°
As with the traditional method T;ncr ,~ca; must be stable; however, it could be much different from T;n~r ref which means in turn that it is not necessary to use expensive, highly accurate crystals. On the other hand, it is necessary to have accurate values of T~,n~i and Tsynca . which means that the synchronization device, the reader, must have be calibrated for time or have access to an atomic clock (as for example through the Internet). Mass produced tags in accordance with the present invention will be of lower cost in comparison to tags which provide time keeping in accordance with traditional methods, since it is only necessary to have the synchronizing devices accurate. In this case the reader will provide the required accurate timing, it being noted that the reader will be a low volume production device in comparison to the tag, which will be a high volume production device.
In summary of the foregoing the present invention provides an inexpensive tag that can be included in any type of shipping container, with any type of product, and which will monitor temperature excursions with respect to predetermined limits or ranges. The tag processes data on board, using a unique time keeping process and requires very little memory to retain the processed data. The data can be downloaded using RFID technology to a reader should there be any excursions during shipment or storage. The tag uses a simple visual indicator to alert the user to any excursions once the tag has been turned off at its destination. The temperature sensor is of the digital type and can measure temperature in 1°C increments. It will have an accuracy of t1°C from -20°C to +30°C. It can support one additional sensor, to sense for example humidity or vibration. It utilizes a programmable status LED warning light.
It records a long-term temperature histogram, with each histogram having up to bins. Each such bin can store up to 65,536 time points and it can record up to excursions when the sensed temperature leaves the specified range. It provides for real-time, on-board data analysis. It communicates with its host (the reader) using proprietary RF communication protocol. It has a unique 32-bit ID number, assuring absolute traceability because no two tags will be alike. It provides a 1 minute time resolution of recorded events and it provides an accuracy of timing reported of ~5 minutes if the data is scanned within 60 days. The battery operating voltage is 2.5V
to 3.5V and the maximum storage time in the non-active mode is 12 months. The maximum operating time in the active mode is 6 months. The operating temperature ranges are -30°C to +60°C in the non-active mode and -20°C to +30°C in the active mode. Data can be retrieved for a period of up to 7 years. The RF reader range is 5cm or greater and two tags could be read at the same time without any fear of the transmitted data being compromised. The tag's internal clock is accurate to +2 minutes/month. The tag is capable of processing and storing the data in protected logic file format (.Idf). The semi-flexible shape of the tag is resistant to temperature, humidity, vibration and shock.
The foregoing has described a unique tag that can be used on any type of container, pallet, bag, package, etc. to monitor and report on environmental changes experienced by the package during shipment and/or storage, providing useful information in a reliable, inexpensive manner to a user. The significant features of the tag have been described, but it is understood that alterations and/or additions to those features could be accomplished by a skilled person without departing from the spirit of the invention.
g - _ r _ _ .r.~.rr..~______ _
Claims
1. A tag for attachment to a container or similar package being shipped and/or stored, said tag comprising: a central processing unit (CPU); a timer; a crystal resonator connected to said timer; a measuring block connected to said CPU;
sensing means connected to said measuring block; a communications block connected to said CPU; a feedback block connected to said CPU; and an EEPROM connected to said CPU;
whereby in use said sensing means senses environmental changes to which said package is exposed during shipment and/or storage; said CPU processes signals received from said sensing means and stores processed data for later retrieval; and when required said CPU communicates such processed data via said communications block to a party interested in such processed data.
sensing means connected to said measuring block; a communications block connected to said CPU; a feedback block connected to said CPU; and an EEPROM connected to said CPU;
whereby in use said sensing means senses environmental changes to which said package is exposed during shipment and/or storage; said CPU processes signals received from said sensing means and stores processed data for later retrieval; and when required said CPU communicates such processed data via said communications block to a party interested in such processed data.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002472809A CA2472809A1 (en) | 2004-06-30 | 2004-06-30 | Rfid sensor tag with on-board processing |
| PCT/CA2005/001032 WO2006002534A1 (en) | 2004-06-30 | 2005-06-30 | Rfid sensor tag with on-board processing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002472809A CA2472809A1 (en) | 2004-06-30 | 2004-06-30 | Rfid sensor tag with on-board processing |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2472809A1 true CA2472809A1 (en) | 2005-12-30 |
Family
ID=35589010
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002472809A Abandoned CA2472809A1 (en) | 2004-06-30 | 2004-06-30 | Rfid sensor tag with on-board processing |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA2472809A1 (en) |
| WO (1) | WO2006002534A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008008426A2 (en) * | 2006-07-13 | 2008-01-17 | Abbott Cardiovascular Systems Inc. | Radio frequency identification monitoring of stents |
| DE102008021490A1 (en) * | 2008-04-29 | 2009-11-05 | Fachhochschule Münster | Sterilization process monitoring method for e.g. medical instrument, involves transferring identification data of articles that are sterilized, and storing time and temperature measurement for sterilization |
| EP2556392A2 (en) * | 2010-04-07 | 2013-02-13 | Mc10, Inc. | Methods and apparatus for measuring technical parameters of equipment, tools and components via conformal electronics |
| US9012784B2 (en) | 2008-10-07 | 2015-04-21 | Mc10, Inc. | Extremely stretchable electronics |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7636031B2 (en) | 2006-05-01 | 2009-12-22 | Honeywell International Inc. | Sensor system including multiple radio frequency identification tags |
| WO2010094294A1 (en) * | 2009-02-17 | 2010-08-26 | Siemens Aktiengesellschaft | Transport packaging for a field device for process instrumentation |
| US20130118255A1 (en) * | 2009-12-17 | 2013-05-16 | Gilman Callsen | Methods and apparatus for conformal sensing of force and/or change in motion |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01196518A (en) * | 1988-01-30 | 1989-08-08 | Dainippon Printing Co Ltd | Sensor card |
| GB2308947A (en) * | 1996-01-04 | 1997-07-09 | I D Systems Ltd | Identification tag with environmental sensing facility |
| US6712276B1 (en) * | 1999-01-29 | 2004-03-30 | International Business Machines Corporation | Method and apparatus for automated measurement of properties of perishable consumer products |
| US6359444B1 (en) * | 1999-05-28 | 2002-03-19 | University Of Kentucky Research Foundation | Remote resonant-circuit analyte sensing apparatus with sensing structure and associated method of sensing |
| CA2383049A1 (en) * | 2002-04-23 | 2003-10-23 | Information Mediary Corporation | Recording tag and reading system |
| CA2387106A1 (en) * | 2002-05-21 | 2003-11-21 | Information Mediary Corporation | Method for measuring temperature using a remote, passive, calibrated rf/rfid tag including a method for calibration |
-
2004
- 2004-06-30 CA CA002472809A patent/CA2472809A1/en not_active Abandoned
-
2005
- 2005-06-30 WO PCT/CA2005/001032 patent/WO2006002534A1/en active Application Filing
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008008426A2 (en) * | 2006-07-13 | 2008-01-17 | Abbott Cardiovascular Systems Inc. | Radio frequency identification monitoring of stents |
| WO2008008426A3 (en) * | 2006-07-13 | 2008-02-28 | Abbott Cardiovascular Systems | Radio frequency identification monitoring of stents |
| US7757543B2 (en) | 2006-07-13 | 2010-07-20 | Advanced Cardiovascular Systems, Inc. | Radio frequency identification monitoring of stents |
| US9188558B2 (en) | 2006-07-13 | 2015-11-17 | Advanced Cardiovascular Systems, Inc. | Radio frequency identification monitoring of stents |
| US10145811B2 (en) | 2006-07-13 | 2018-12-04 | Abbott Cardiovascular Systems Inc. | Radio frequency identification monitoring of stents |
| DE102008021490A1 (en) * | 2008-04-29 | 2009-11-05 | Fachhochschule Münster | Sterilization process monitoring method for e.g. medical instrument, involves transferring identification data of articles that are sterilized, and storing time and temperature measurement for sterilization |
| US9012784B2 (en) | 2008-10-07 | 2015-04-21 | Mc10, Inc. | Extremely stretchable electronics |
| EP2556392A2 (en) * | 2010-04-07 | 2013-02-13 | Mc10, Inc. | Methods and apparatus for measuring technical parameters of equipment, tools and components via conformal electronics |
| EP2556392A4 (en) * | 2010-04-07 | 2014-03-19 | Mc10 Inc | Methods and apparatus for measuring technical parameters of equipment, tools and components via conformal electronics |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2006002534A1 (en) | 2006-01-12 |
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