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RFID
June 17, 2009Dr. Erick C. Jones
University of Nebraska-Lincoln
ContentsContents
• RfSCL Lab Introduction
• RFID Overview– Applications
– How It Works• Readers
• Antennas
• Tags
– Challenges
• Questions
RfSCL Lab RfSCL Lab IntroductionIntroduction
RfSCL Facility 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)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 LayoutRfSCL Layout
7
RfSCL FacilityRfSCL Facility
Plan PredictDefine
Measure
Analyze
Identify
Perform
Design Optimize Verify
RfSCL Research Methodology RfSCL Research Methodology DFSS-ResearchDFSS-Research
Measure – Set up accurate metricsMeasure – Set up accurate metrics
Analyze – Current SituationAnalyze – Current Situation
Identify – Relevant TechnologyIdentify – Relevant Technology
Design – New Technology from knowledge Design – New Technology from knowledge
Optimize – Test in live situation and improveOptimize – Test in live situation and improve
Verify – Validate technology in live situationVerify – Validate technology in live situation
PredictPredictPredictPredict
PerformPerformPerformPerform
Define – Clear problem definitionDefine – Clear problem definitionPlanPlanPlanPlan
RfSCL DFSS-ResearchRfSCL DFSS-Research Process StepsProcess Steps
RfSCL Multi Disciplinary RfSCL Multi Disciplinary Approach in RFID ResearchApproach 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 RfSCL Multi Disciplinary Approach VisionApproach Vision
Reader
Tag
AntennaRadio Frequency
Power InductionData reading and writing to the
ICElectrical EngineeringElectrical Engineering
CommunicationCommunicationEngineeringEngineering
Frequency
Computer ScienceComputer Science
Interface ProgramTag ID Mapping
Data Storage and Retrieve
Cattle Tracking (Agriculture Eng.Agriculture Eng.)Warehouse Management (Industrial EngIndustrial Eng.)
ApplicationsApplications
RFID integrated with Supply ChainRFID integrated with Supply Chain(EPC Global )(EPC Global )
RfSCL Supply Chain Logistics RfSCL Supply Chain Logistics Research DefinitionsResearch 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 RfSCL RFID Research DefinitionsResearch 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 ProjectsPrevious 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 Current Projects (Fall 2009)(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
RFID RFID OverviewOverview
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/InterrogatorReader/Interrogator
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
TagsTags
TagsTags
Barcode identification RFID identification
• 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.
• 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.
Data
Power & Commands
0101011010101011
TagsTags
• 639382 = manufacturer’s identification number• 00039 = item number or Stock Keeping Unit, SKU• 3 = check digit to validate correct scanning of code
UPC code EPC-96 bit code
• The EPC code contains: code type, near infinite companies, the UPC SKU, and item’s S/N
TagsTags
4 Essential Physical Components of a Tag
•IC (Integrated Circuit, silicon)•Interconnect media, conductive•Antenna•Substrate
conductive adhesive or solder
antenna connectionsIC
paper or plastic acting as the antenna carrier
• logic• modulator• receiver• transmitter• memory
TagsTags
A Tag’s Micro-chip is a very small package for low cost RFID labels
TagsTags
125 kHz 13.56 MHz 860-950 MHz
• Inductive• 20-70 feet of wire• 50-2,000 turns
• Inductive• Planar or wire• 3-20 turns
• Backscatter• Planar foil or conductive ink
TagsTags
Tag Success FactorsTag 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
TagsTags
1. There are several different types of tags at many different frequencies
2. The two main differences in tags are their frequency and their type
3. 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
TagsTags
Tags & PowerPassive 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 Tagat 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 RFID Standards
• Standardizing RFID–Similar to universal product code (UPC) for
barcodes.–International Standards Organization (ISO)
42
Questions?Questions?AnnouncementsAnnouncements
• RFID in Logistics is in publication
• Currently working on book with CRC: Taylor Francis
“RFID/AIT in Military Logistics”
Erick C. Jones, PhD, PE, CSSBBAssociate Professor
Industrial and Management Systems EngineeringUniversity of Nebraska – Lincoln
(402) 472-3695, ejones2@unl.edu
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