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RFID. June 17, 2009 Dr. Erick C. Jones University of Nebraska-Lincoln. Contents. RfSCL Lab Introduction RFID Overview Applications How It Works Readers Antennas Tags Challenges Questions. RfSCL Lab Introduction. RfSCL Facility . Mission:
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RFID June 17, 2009 Dr. Erick C. Jones University of Nebraska-Lincoln
Contents RfSCL Lab Introduction RFID Overview Applications How It Works Readers Antennas Tags Challenges Questions
RfSCL Facility Mission: “Providing integrated solutions in logistics and other data driven environments through automatic data capture, real world prototypes, and analysis” Equipment Active and Passive Tags/Readers and software (Matrics, Alien, Samsys), Hytrol conveyor and GCS WMS, HP5555 Mobile Active Reader and Software, RF Code Active tags, SAVI Active Tags and Reader (WMRM/WORM)
RfSCL Team (Fall 2009) Faculty Dr. Erick C. Jones (Director) Dr. Mike Riley (Associate Director) Graduate Students Dwight Mosbey (DM)- PhD Liyuan Zhang(LZ),- PhD Casey Richards(CR), -PhD Maurice Cavitt(MC)- PhD Jonathan Carlson(JC), Nancy Kong(NK), Jian (Hank) Han(JH) , Bode Alabi (BA) Rama Thummalapalli (RT), Jairo De Jesus(JD) Undergraduates As many as I can “afford”
RfSCL Research Methodology DFSS-Research Plan Predict Perform Define Analyze Measure Design Optimize Verify Identify
RfSCL DFSS-Research Process Steps • Define – Clear problem definition • Plan • Measure – Set up accurate metrics • Analyze – Current Situation • Predict • Identify – Relevant Technology • Design – New Technology from knowledge • Optimize – Test in live situation and improve • Perform • Verify – Validate technology in live situation
RfSCL Multi Disciplinary Approach in RFID Research • Applied Research will be attracted to the lab if presented as unified Multi Disciplinary Team on RFID Research • RFID has 3 components • Data Acquisition (IE,CE, CM, AgEng) • Data Transmissions (EE, Communications) • Database Management (CIS, MIS) • A robust applied Research project will incorporate these three components which is best addressed using an multi Disciplinary Team
RfSCL Multi Disciplinary Approach Vision Radio Frequency Antenna Tag Reader Frequency Communication Engineering Power Induction Data reading and writing to the IC Electrical Engineering Cattle Tracking (Agriculture Eng.) Warehouse Management (Industrial Eng.) Interface Program Tag ID Mapping Data Storage and Retrieve Applications Computer Science
RfSCL Supply Chain Logistics Research Definitions • Applied Research • Facility/Transportation Network Modeling • Warehouse/Manufacturing layout design • WMS/LES/TMS&ERP System integrations • RFID & Barcode systems integration for inventory “visibility” • Theoretical Research Models • Mathematical modeling inventory policies • Stochastic modeling of SC networks • Algorithm development for systems which minimize material handling functions
RfSCL RFID Research Definitions • Applied Research • RFID & Barcode integration into WMS and ERP systems • RFID test of EPC/ISO specs & integration including Military UID • RFID in industrial application such as conveyors and automated sorters such as tilt tray sortation • RFID testing of consumables in NASA Space Center storage containers • Theoretical Research Models • RFID integration into GPS/GIS • RFID antennae/integrated circuit manufacturing process design • Alternate active tag standard development
Previous Projects Supply Chain Supply Chain Network modeling for a city government. Strategic Master Plan for Logistics Operations and Local Company in including Logistics System Analysis RFID Comparative study: RFID Vs. UCC 128 Barcodes Cost analysis for implementing RFID in Libraries. RFID impact on enforcing the use of collaborated tools at a defense manufacturer Integration of RFID and GIS system for ticket/seat location Cost reduction of tags through micro manufacturing process design Applying RFID technology to comprehensive sports timing in a marathon RFID testing of consumables in NASA Space Center storage containers Integration of Animal ID into systems for Cattle Tracking RFID in the Operating Room and Patient tracking RFID in Construction RFID economics of automated checkout for retail companies
Current Projects (Fall 2009) RFID • Imbedded RFID License Plates (DOT) • ROW Underground RFID tags (TxDOT) • RFID RTLS (NASA) Logistics • Corporate Supply Chain Analysis • Grain Terminal Network Analysis www.unl.edu/rfscl
Applications of RFID Secure Access Control Inventory Tracking Exxon/Mobil Speedpass Electronic Toll Collecting Animal Tracking Smart Shelves Electronic Article Surveillance (EAS) clothing stores, libraries 2 - 10 MHz, up to 80 inches between gates
How RFID Systems Work 1. The antenna of the interrogator (reader) emits radio signals EM field transmitted can be continuous Antennas come in a variety of shapes/sizes Can be built-in or external Circular polarization of reader antenna allows any tag antenna orientation Range: 1 inch to 100+ feet 2. Transponders (tags) respond with their unique code Microchip / Integrated Circuit Antenna: copper or aluminum coil Encapsulating material: glass or polymer 3. Reader receives and decodes tag information and sends it to a computer via standard interfaces Fixed or portable Software available to filter data and monitor the network
Reader A device that captures and processes tag data then passes the digital data to a computer system Readers are also known as: Interrogators Reader/Writers Couplers Reader function: supply power to passive and semi-active tags provide command data to tags capture returned tag signals and process into a digital bit stream output data to another output device or to a computer system write data to the tag
Reader Electronics containing a small radio and computer with memory Transmits radio waves that are received by the Tag Decodes information received as radio waves from the Tag
Reader In operation, the reader has a very simple purpose: read the tag(s) in its field and pass appropriate data to a host A reader passes the following information to a host: Tag ID Timestamp Antenna ID Reader ID Data is output from the reader by various interface methods The host software receiving the reader data makes decisions on what data is logged into the supply chain enterprise software
Reader Readers can be mounted in configurations of: portal: dock door conveyor: slow or fast multi-antenna: portals and conveyors single antenna: hand held Control Externally triggered photo-diode network PLC Continuous operation Operation Setup Reader is configured for the target application Multi-options during setup
Reader In Summary: Readers are radio frequency devices that: Transmit and Receive RF signals Contain a control unit to execute commands Incorporate an interface to transfer data Another way to look at a reader other than its immediate functionality, is that a reader is a node on a network receiving, aggregating, filtering and transmitting data
Antenna What is an Antenna? An antenna is a transducer that converts radio frequency electric current to electromagnetic waves that are then radiated into space. An antenna is said to be vertically polarized (linear) when its electric field is perpendicular to the Earth's surface. An example of a vertical antenna is a broadcast tower for AM radio or the "whip" antenna on an automobile. Horizontally polarized (linear) antennas have their electric field parallel to the Earth's surface. Television transmissions in the USA use horizontal polarization. Passive RFID Tags are sensitive to polarization effects.
Antenna Antennas are designed to resonate (allow the radio wave to be received) at the desired frequency for LF and HF RFID UHF antennas reflect the radio wave with a length of ~ ½ a wavelength
Antenna The Perfect Antenna Picks up desired signal Efficient use of energy Filters out undesired signals Space envelope is minimum Structurally light and strong Withstands high wind loads
01010110 10101011 Power & Commands Data Tags Barcode identification RFID identification • Upon power and command from a reader, the RFID tag emits data, and the reader discerns a sequence of numbers • The numbers are arranged according to a prescribed format, such as EPC’s 96-bit, which also describes attributes about the item. • A scanner reads reflected light from barcodes and then discerns a sequence of numbers • The numbers are arranged according to a prescribed format, like UPC or EAN, and describe attributes about the item.
Tags EPC-96 bit code UPC code • 639382 =manufacturer’s identification number • 00039 = item number or Stock Keeping Unit, SKU • 3 = check digit to validate correct scanning of code • The EPC code contains: code type, near infinite companies, the UPC SKU, and item’s S/N
IC conductive adhesive or solder Tags 4 Essential Physical Components of a Tag • IC (Integrated Circuit, silicon) • Interconnect media, conductive • Antenna • Substrate antenna connections • logic • modulator • receiver • transmitter • memory paper or plastic acting as the antenna carrier
Tags A Tag’s Micro-chip is a very small package for low cost RFID labels
Tags 125 kHz 13.56 MHz 860-950 MHz • Inductive • Planar or wire • 3-20 turns • Inductive • 20-70 feet of wire • 50-2,000 turns • Backscatter • Planar foil or conductive ink
Tags Tag Success Factors • Orientation vs. reader antenna type • Multi-path UHF signals: direct & reflected • Noisy environments: Electro-Magnetic Interference • Moving vs. static tags: time in antenna field • Orientation and location of the tag on an item is critical to maximize success
Tags • There are several different types of tags at many different frequencies • The two main differences in tags are their frequency and their type • These type differences are: • Passive: All power comes from reader • Semi Active: Battery assisted power for the IC operation • Active : Battery power assists IC & transmit power
Tags Tags & Power • Passive Tags: <5m • All power comes from reader • Read distance is constrained by power from reader • Most common and inexpensive tags: >95% of market • epc-Global’s: Class 0+, Class 1, and Class1-Gen 2 • (Semi) Active Tags: 10m to <200m • Battery assisted power for the IC operation • IC kept in “stand-by” until reader detected • IC wakes-up and transmits at normal, passive levels • epc-Global’s Class 3 tags, enables sensors, ~Q2’06 • Active Tags: 10m to <1000m • Battery power assists IC & transmit power • epc-Global’s Class 4 tags, ~2007 • Range is increased for all freqs, and up to 1km for specialized applications such as U.S. DOD Active Tag at 2.45GHz
Active vs. Passive Tags Active Tags Battery powered – would require periodic replacement/recharging Typically read/write, up to 1MB of memory Greater range (30 meters possible with UHF) Limited operational life: depends on operating temp. and battery Ultra Wide Band (UWB) systems use time difference of arrival of transmitted pulses to triangulate position Passive Tags Powered by energy transmitted by reader Typically read only, 32 – several Kbytes of memory Virtually unlimited lifetime, lighter, smaller, and cheaper 13.56 MHz tags powered by inductive coupling EM field emitted by the reader creates a voltage drop in the coil Tag modulates the signal (amplitude/frequency/phase) and sends its unique code back to the reader UHF tags (915 MHz and 2.45 GHz) powered by propagation coupling Similar to 13.56 MHz tags, but since signal travels greater distances, field strength decreases with distance (depends on tag orientation and other factors)
Frequency 13.5MHz 915MHz 2.4GHz
RFID Challenges Lower Frequencies Lower cost tags Higher performance around metals and liquids Higher Frequencies More prone to reflection, refraction, and diffraction High data transfer rate Longer read ranges Interference less of a problem with high frequencies Frequency Hopping Spread Spectrum (FHSS) can be used to avoid interference Common RFID Frequencies (ISM Band) 13.56 MHz Range up to ~1.5 m with credit card sized tag 915 MHz Typical range up to ~3 m 2.45 GHz Typical Range up to ~5 m BCR operates at this frequency
RFID Challenges, cont. Range Longer range with larger antenna, higher power, frequency, and cost Limited by environmental conditions and metal obstacles Standards ISO – some standards for some frequencies, e.g. ISO 15693 and ISO 18000 EPC – Auto-ID Center's Electronic Product Code could replace the UPC as the standard for UHF; 64, 96, 128 bits of information is stored in a specified format, allowing for billions of unique serial numbers Performance of ISO and EPC-compliant tags should be similar, but sticking to standards increases flexibility of technology in the future
RFID Standards 42 • Standardizing RFID • Similar to universal product code (UPC) for barcodes. • International Standards Organization (ISO)
Questions?Announcements RFID in Logistics is in publication Currently working on book with CRC: Taylor Francis “RFID/AIT in Military Logistics” Erick C. Jones, PhD, PE, CSSBB Associate Professor Industrial and Management Systems Engineering University of Nebraska – Lincoln (402) 472-3695, ejones2@unl.edu