US7295108 - (12 United States Patent Corrado et al...

Info icon This preview shows pages 1–16. Sign up to view the full content.

View Full Document Right Arrow Icon
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 4
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 6
Image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 8
Image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 10
Image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 12
Image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 14
Image of page 15

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 16
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: (12) United States Patent Corrado et al. US007295108B2 US 7,295,108 B2 Nov. 13, 2007 (10) Patent No.: (45) Date of Patent: (54) ACTIVE RFID TAG UTILIZING A SECONDARY COMMUNICATION MODE (75) Inventors: Anthony P. Corrado, Evergreen, CO (US); Rex Logan, Superior, CO (US) (73) Assignee: Symx Systems, Inc., Miami, FL (US) ( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 131 days. (21) Appl. No.: 11/082,327 (22) Filed: Mar. 17, 2005 (65) Prior Publication Data US 2005/0206503 A1 Sep. 22, 2005 Related US. Application Data (60) Provisional application No. 60/555,153, filed on Mar. 22, 2004. (51) Int. Cl. G083 1/08 (2006.01) (52) US. Cl. ............................... 340/539.22; 340/5.92; 340/10.1; 340/10.51; 340/572.1 (58) Field of Classification Search ............. 340/572.1, 340/572.4, 505, 10.1, 5.92, 539.22, 539.26, 340/10.51, 10.41; 235/385; 705/28 See application file for complete search history. (56) References Cited U.S. PATENT DOCUMENTS 5,640,144 A * 6/1997 Russo et al. ............. 340/568.1 20 230 I Optical Trigger I 5,742,914 A * 4/1998 Hagenbuch .................. 701/35 5,774,876 A * 6/1998 Woolley et al. ............... 705/28 6,104,295 A 8/2000 Gaisser et al. 6,154,139 A 11/2000 Heller 6,211,790 B1 4/2001 Radomsky et al. 6,493,649 B1 * 12/2002 Jones et al. ................. 702/150 6,614,721 B2* 9/2003 Bokhour ................ 340/825.49 6,765,484 B2 7/2004 Eagleson et al. 6,838,992 B2 1/2005 Tenarvitz 2003/0227386 A1* 12/2003 Pulkkinen et al. ....... 340/573.1 2005/0040241 A1* 2/2005 Raskar ....................... 235/385 2006/0065489 A1* 3/2006 Oh et al. .................... 187/284 * cited by examiner Primary ExamineriThomas Mullen (74) Attorney, Agent, or Firmilacques M. Dufin, Esq; Innovation Law Group, Ltd. (57) ABSTRACT Embodiments of the present invention relate to methods and systems for radio frequency identification. According to one embodiment, a radio frequency identification system com- prises a radio frequency identification tag. The tag comprises a radio frequency transmitter and an optical receiver. A reader is communicatively coupled with the tag and is adapted to receive information from the radio frequency identification tag via the radio frequency transmitter of the radio frequency identification tag. The system also includes a trigger communicatively coupled with the tag. The trigger is adapted to send information to the radio frequency iden- tification tag via the optical receiver of the radio frequency identification tag. 22 Claims, 8 Drawing Sheets 13D one US 7,295,108 B2 Sheet 1 of 8 CD 3 . l— \ \ \ \ \ IO U) (6 Nov. 13, 2007 S U.S. Patent .630”. me am U.S. Patent Nov. 13, 2007 Sheet 2 0f 8 US 7,295,108 B2 , 100 Figure 2A 110 I'I/ -3 L. 120 US 7,295,108 B2 Amrofiuczccw Sheet 3 of 8 09, lull at Nov. 13, 2007 U.S. Patent 8N >0: whomcwm Ems 35:00 mzomfi “E EEEmcmb “E 355 8:89me mEc. —.........-—..-__.__ .—._— ~——- .J 03 53829... 22092:: EEEmwcmc. ufl-§£ “magma nm.-m¢:_ III-IIIIII q .9“. ma? m=>=._. Sm ll .. uuuuuuu x _ ox” _ US 7,295,108 B2 8 f 0 4 a m chm I S 7 m 2 omm 39 m_._.<._.m =20: O... ZQEmZE... DZ< J ZOFDm—hmc 4.4.205 0222002. mOu W DOEMn. ZOFOmhmn mmZmowzéh .26.me N com Ill. on on ZOF<EDD 02:40.... DOE—mm 02:40.“. U.S. Patent m .9; US 7,295,108 B2 ZOFUMkwo hmxo<m ZOFOMFMO mmqnn. (#40 "—0 wao<m meUmm O... DOW—mm 00 ,m .20.. mmzmomzék ioEo 5 % 3m h S Tl'Pl'lllnnllllll‘i m $305 325:: m {Eu ”.0 mExQE 3, wzfiooz 205.0 1 v. 0 N com mama—Dn— ooEmm wz_._._on_ .2.sz U.S. Patent 0 9:9; 05:. US 7,295,108 B2 II :0: 8 8o veto...— xm Q. «2:; 5.55:5 .m 6 m «M m cum 33.3 :m «a i L... cm 3 7 0 0 2a 050.. B 2.» 3:8. gm 3 a...» FL :9. . V. 0 N :w: 3.3.“. 8m gm v msocohzocam Tl untan— «E .53. IL U.S. Patent .23 US 7,295,108 B2 5 Esmi f‘l‘ll'llll “9.28 ‘llllllll". M oocozomw w ofi. 3.3.... 3020533 S 3:2..qu 3:511: 7 cozwfizmo i1 —\ m. ..._.Tree?Fooooooooomooo§.Uooooo cocoa—vow 8» 8.3.83 o: U.S. Patent mocozcum on? 2252.... US 7,295,108 B2 m 9:9“. 8 f M £5 38 B .350 3 2:: 3223.8 ll m may flootm ohsamhoafioh 53> 32.3. :m ll 7 0 0 2 u, v. 25 m l :m w. Tlllli 238095... 05.33 8". 50:3. gm U.S. Patent US 7,295,108 B2 1 ACTIVE RFID TAG UTILIZING A SECONDARY COMMUNICATION MODE RELATED APPLICATION This application claims the benefit of US. Provisional Application No. 60/555,153 filed Mar. 22, 2004, which is incorporated herein by reference. FIELD OF THE INVENTION The invention relates generally to the field of Radio Frequency Identification (RFID) tags and systems. More particularly, the invention relates to RFID tags that utilize a combination of radio frequency (RF) signals and localized secondary communication modes. BACKGROUND Radio Frequency Identification (RFID) applications are proliferating as the economies of automated tracking and identification are being realized by the global community. RFID is the ability to detect, read, and/or write data to tags that are aflixed to “things.” Cost of the RFID tag is the predominant parameter dictating applicability of this tech- nology. There are several categories of RFID tags and readers in use and proposed. The technology currently is predomi- nantly passive. Passive implies that the tags have no battery. They derive power from a reader that transmits electromag- netic energy to the tag, which in turn reflects or modulates the energy signal back to the reader. While passive tags and readers are relatively inexpensive, they have severe limita- tions dictated by physics. For example, passive tags and readers have a limited range (from 0.1 cm to 6 meters) and are non-operational when blocked or shielded by metal objects, liquids and certain solid materials. In such systems, data rates are limited to approximate 6 mph “drive-thru” speeds thru portals, conveyors, etc. Further, passive systems have limited data storage capacity and no sensing capability. There are also “active” tags that derive their power from incorporated batteries. Such devices add significant value to the process of inventory tracking and In Transit Visibility (ITV) enabling processes such as Total Asset Visibility (TAV). Relative to passive tags, active tags have a greater data acquisition range (0 to 100 meters). Active tags have the ability to provide Real Time Location System (RTLS) effectivity, to automatically provide theft deterrence thru continuous and automatic “presence detecting,” and to enable tracking through processes such as manufacturing, shipping, on trucks, forklift transfer, and warehousing. A disadvantage of active tags is that they cost more than passive tags and this requires that these tags achieve maxi- mum performance, add value to supply chain management and achieve these goals with absolute lowest cost. Many active tags simply “beacon” or periodically trans- mit data. However, this approach has limitations. In certain instances, the continuous battery consumption is prohibitive since RF data transfer is only required when handling or processing the tagged items. In addition, it is often desired to associate a specific tagged item with a process such that the tagged item can be associated with a specific event, time or operator and beacon tags do not provide this utility. It is often desired to locate a specific tagged item in a situation where many identical items are tagged. It may be desired to be able to change the tag’s mode of operation, i.e. turn the beacon mode “off or on”, or change the beaconing rate. A 10 15 20 25 30 35 40 45 50 55 60 65 2 specific tag should be able to respond under any of these circumstances. The ability to transfer data from the tag via a medium other than RF signals is also a desirable func- tionality since many locales and operations (such as aircraft flight) require RF silence. Therefore, current commercial tags offer secondary trig- gering or communication modes of operation. “Triggering” is the remotely transmitted command to a tag directing that it execute a function such as “transmit RF, store data, or take a sensor reading”. These secondary modes are restricted to the use of magnetic or RF fields to effect the triggering or communication. RF and magnetic triggered tags have the problem of being non-discriminatory, that is, the nature of RF fields is that they cannot be restrained to a narrow effective Field of View (FOV) and hence are not tag specific in the presence of many tags. They are also costly. Low frequencies (magnetic domain) such as 125-134 KHz require very close proximity to actuate the tag response and often will not work with the tag attached to ferrous objects. Higher frequencies such as 915 MHz also are affected by metal items and are often reflected making single tag actuation less reliable than is required. All of these triggering mechanisms are large, bulky, and expensive. Handheld triggers or communicators are also large and bulky. Many applications require that the tags and readers comply with Intrinsic Safety requirements. This task is significantly complicated and more costly with low fre- quency devices due to the necessity for relatively high source power. Additionally, the transfer of data is at rela- tively low speeds. SUMMARY In accordance with the present invention, the above and other problems are solved by a low cost, active Radio Frequency Identification (RFID) tag having a Radio Fre- quency (RF) mode for transmitted signals coupled with an optical or ultrasonic secondary mode of communication and/or triggering. This combination of dual mode commu- nications allows long range and autonomous tracking of objects to be realized through the RF transmit mode while providing the local communication (transfer) of data simul- taneously through the secondary mode of communication. The ability to communicate through optical or ultrasonic secondary mode means that radio silence can be maintained (such as when on aircraft) while the total tag functionality of data transfer can be accomplished through the secondary mode. It also means that a tag can be triggered to transmit the RF signal on a discriminatory basis. Another aspect of the present invention relates to methods and systems for transferring data wirelessly that eliminates the requirement for a resonator or other accurate time reference to control the timing of the input or output data pulse train. Elimination of this control element permits the RFID tag to operate with its associated reader in the pres- ence of temperature induced variations in the control timing. Embodiments of the invention may be implemented as a computer process, a computing system or as an article of manufacture such as a computer program product or com- puter readable media. The computer program product may be a computer storage medium readable by a computer system and encoding a computer program of instructions for executing a computer process. The computer program prod- uct may also be a propagated signal on a carrier readable by a computing system and encoding a computer program of instructions for executing a computer process. US 7,295,108 B2 3 These and various other features as well as advantages, which characterize the present invention, will be apparent from a reading of the following detailed description and a review of the associated drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a high-level depiction of elements comprising an exemplary system of tags, handheld triggers/readers and fixed readers according to one embodiment of the present invention. FIGS. 2A-2C are illustrations of the modes of signal functionality between the various elements of the system illustrated in FIG. 1. FIG. 3 is a block diagram of an exemplary embodiment of the tag portion of the system illustrated in FIG. 1. FIG. 4 illustrates, according to one embodiment of the present invention, the relationship between polling periods, polling durations, transition from the polling mode to the data communication mode of operation and shows the approximate relationship of the incoming infra-red “wake- up” signals with respect to the polling duration and to the receive period of the infra-red transceiver. FIG. 5 illustrates, according to one embodiment of the present invention, the relationship between polling periods, polling durations, transition from the polling mode to the data communication mode of operation and shows the approximate relationship of the incoming infra-red “wake- up” signals with respect to the polling duration and to the receive period of the infra-red transceiver. FIG. 6 illustrates the bit period for the calibration, zero, one, and synchronous bits according to one embodiment of the present invention. FIG. 7 illustrates the relationship between bit periods transmitted in communication packets according to one embodiment of the present invention. FIG. 8 illustrates the relationship between bit periods when temperature variation adjustments are incorporated according to one embodiment of the present invention. DETAILED DESCRIPTION One aspect of the present invention relates to a low cost Radio Frequency Identification (RFID) tag having a Radio Frequency (RF) mode for transmitted signals coupled with an optical or ultrasonic secondary mode of communication and/or triggering. This combination of dual mode commu- nications allows long range and autonomous tracking of objects to be performed through the RF transmit mode while allowing the local communication (transfer) of data to be performed simultaneously through the secondary mode of communication. The ability to communicate through optical or ultrasonic modes means that radio silence can be main- tained (such as when on aircraft) while the total tag func- tionality and data transfer can be accomplished through the secondary mode. It also means that a tag can be triggered to transmit the RF signal on a discriminatory basis of indi- vidual tags. Most RFID systems utilize additional infrastructure such as fixed readers to affect operation. The ability to utilize existing infrastructure equipment such as mobile computers to affect the data exchange is a significant cost reduction enabling the use of active tags. The RFID tags of this invention can function with existing mobile computers or PDAs. FIG. 1 is an overview of elements that can comprise a dual communication RFID system according to one embodiment 10 15 20 25 30 35 40 45 50 55 60 65 4 of the present invention. The system in this example com- prises a number of tags 20-26, optical triggers 30 and readers (RF receivers, infra-red transceivers) 10 with an antenna 40. Readers are defined herein as devices that receive RF and/or optical signals and transmit either RF or optical signals and which process these signals. As noted above, triggers and readers can be implemented as specialized equipment or as mobile computers, PDAs, or other types of devices. As described herein, a dual mode RFID tag is a device that is battery powered and is attached to objects. The tag has two communication modes, a bi-directional optical or ultrasonic mode and an RF mode. The tag can used to identify the object to which it is attached and also can store information that can be retrieved by either the optical or RF modes of operation. The tag can be used for item tracking, status, identification, location, presence, environmental sensing or data storage. In the exemplary case the tags 20-26, readers 10, and triggers 30 each possess dual modes of operation. That is, they can have bi-directional optical and/ or ultrasonic modes and at least receive or transmit RF modes of operation. The readers 10 also have bi-directional RF capability including multi-frequency modes of operation. In an exemplary embodiment, the optical frequency domain can be infra-red (IR) between 1-100 microns wavelengths. While FIG. 1 illustrates, and the following discussion describes, an optical trigger 30, optical communications, etc., it should be under- stood that an ultrasonic mode of communication is also contemplated as a secondary communication mode and may be used instead of or in addition to an optical mode of communication. The tags 20-26, as will be discussed in greater detail below, can be equipped with receivers and transmitters enabling optical and/or ultrasonic transceiver operation that can effect bi-directional optical and/or ultrasonic modes of communication 50. The tags 20-26 can also transmit signals through the embedded RF mode of communication 60 to the readers 10 or triggers 30. The triggers 30 and readers 10 can be fixed or handheld mobile devices. According to one embodiment of the present invention, the tags 20-26 can have several modes of operation includ- ing, but not limited to, autonomous transmit, commanded receive and/or transmit, store data, gather sensor data, pro- vide visual responses and more. The tags 20-26 can provide a mode of operation in which they act autonomously to transmit an RF signal periodically on a pre-selected timing basis. They can also be commanded to transmit stored data via either the optical or RF modes of operation. The tags 20-26 can transmit (either optically, RE or both) whenever they are in the presence of an optical communication com- mand signal. The triggers 30 and readers 10 can transmit “bulk” signals to all tags 20-26 in their respective fields of view (FOV) or they can transmit commands to a specific tag by way of unique tag ID values or stored data values. They can also transmit to a single tag in close proximity without the “command” signal being received by an adjacent tag. The commands, in the exemplary embodiment, cause a tag to transmit both its unique identification value (ID)value along with the ID value of the causative communication device, i.e., trigger 30, via the RF or optical/ultrasonic modes 60,50 to readers 10, thus enabling individual tags and communication devices to be both identified and correlated. The infra-red (optical) or ultrasonic modes of communica- tion 50 can also be utilized to transmit data and/or com- mands to and from the tags 20-26. These commands include, but are not limited to, anti-collision RF algorithms, “search for” parameters, mode changes, etc. Such communications US 7,295,108 B2 5 can be stored as data on the tag 20-26 and transmitted Via the RF mode 60 as required. The optical/ultrasonic modes may be initiated by triggers 30 in the form of either handheld or fixed devices in relative proximity to the tags 20-2 6, typically 0-10 meters in range, and (1) cause data to be stored on the tags 20-26 or (2) cause the tag to transmit certain data Via the RF mode 60 or (3) transfer data through the optical/ultrasonic communication mode 50 or (4) trans- fer command and control information to the tags 20-26. By reducing the transmitted power of the optical device, com- munications can be reduced to a distance of several centi- meters, thus communications can be restricted to a single tag even in the presence of multiple tags. This local triggering of the RF signal provides the ability to distinguish a single RFID tagged device from a plethora of similar devices that may be in the general vicinity. It also enables the tagged item ID to be associated with the ID of the triggering device, such as in processing stations or during delivery for issue and receipt functionality. It is an inexpensive and reliable method of transferring data or commanding an alternate tag mode of operation. The exem- plary infra-red mode can utilize both a unique protocol as well as using the IrDA industry open standard protocol. This latter attribute enables existing devices such as Personal Digital Assistants (PDAs) or mobile computers to affect the bi-directional transfer of data, i.e., to be used as a trigger 30. The RF signal can be received locally by a handheld mobile computer or it can be received by fixed readers that, in turn, relay the data back to a central computer data base. The optical signal does not require direct line of sight as it can be reflected off of most surfaces and ...
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern