ELG 4135 Electronics ΙΙΙ Project Professor: Riadh Habash TA: Mohamad Eid TA: Peng He
RFID AUTOMATION IN AN INDUSTRIAL PLANT SIGAS Saudi Industrial Gas Co.LTD.
The Problem … Manufacturer Information serial#, pressure, model Content, …etc Other data can also be programmed on request Asset Management Information Inventory #, receipt, date, current location, …etc Cylinder Filling Information Content, date of last fill, place of last fill, fill counter, …etc Application Software Report Generation Comprehensive reporting, Current status, historical logs, …etc Inspection Information repair, date and location of last inspection and retest, Safety data, …etc
Constructing The Loop Supplier Distributor Customer
Existing Technologies • Component cables or Electrical wires • WiFi • Infrared Signals • Bluetooth • Home RF • RFID
WiFi 802.11 • Wi-Fi setup consists of several Access Points (APs) and several clients. Each AP broadcasts its Service Set Identifier (SSID) through packets called beacons
Bluetooth • Radio frequency standard
Infrared Signals • Light waves of a lower frequency than human eyes can receive and interpret
Home RF • Radio frequency standard
Why is RFID better than using bar codes? • Bar codes are line-of-sight technology, which means people usually have to orient the bar code towards a scanner for it to be read. Radio frequency identification, by contrast, doesn’t require line of sight. • RFID tags can be read as long as they are within range of a reader. • Bar codes have other shortcomings as well. If a label is ripped, soiled or falls off, there is no way to scan the item. • Standard bar codes identify only the manufacturer and product, not the unique item. The bar code on one cylinder is the same as every other, making it impossible to identify which one might pass the inspection.
RFID – An Idea Whose Time Has Come • Radio Frequency Identification (RFID) is a technology with several aspects that correspond to different applications. • The common element of all RFID applications is the use of radio signals to sense the presence of a tagged object and, in most instances, to retrieve data stored on the object.
What is RFID? (Continued) • From the sensing point of view, the many RFID applications are quite diverse, including • Radar • Access control systems and smart cards • Automatic toll collection • Asset tracking (e.g., railroad cars) • Animal tagging, including implants • Hazardous substance tracking • Inventory and supply chain tracking
RFID Components • RFID transponder or an RFID tag : There are several methods of identification, but the most common is to store a serial number that identifies a person or object, and perhaps other information, on a microchip • Tag is attached to an antenna The antenna enables the chip to transmit the identification information to a reader. • The reader converts the radio waves reflected back from the RFID tag into digital information that can then be passed on to computers that can make use of it. • Friendly software
Example RFID Tags Labels with RFID tags embedded 2.5 mm coil-on-chip RFID tag for close proximity applications (Maxell)
Full Empty SIGAS SOLUTION
Frequency Response of Butterworth Filter • All frequencies above 912 MHz are filtered out. • Phase shift at 912 MHz is about -100 degrees.
Half Bridge Power Amplifier Voltage Gain = 0.816 Current Gain = 108 Power Gain = 88 Cross over distortion avoided by 2 diodes
Frequency Response of Power Amplifier • Output voltage is the same for all frequencies. • Output current does not depend on frequency. • Therefore Power Gain is constant.
Transmitted Power • Input voltage = 1.549 V • Input current = 20.418 mA • Input Power = 31.6 mW • LPF output voltage = 0.49 V • LPF output current = 0.074 mA • LPF output power = 36.3 µW • Amplifier output voltage = 0.4 V • Amplifier output current = 8 mA • Amplifier output power = 3.2 mW
Read Range Assumptions: • No propagation loss • Transmission antenna gain is 1 • No noise !!!! PR = PTGR(c/f)2/(4πr)2 For PR = 1 pW r2 = PTGR (c/f)2/PR (4π)2 = [3.2 x 10-3 x 9 x 1016 ] GR / [(912)2 x 1012 x 10-12 x(4π)2] = 2.193 x 106 GR r = 1.48 (GR)1/2 Km
How the circuit works • Assuming the tag uses ASK modulation: • 1 is represented by a 5V sine wave • 0 is represented by 1V sine wave • Comparator gives 1 if the envelope detector output is higher than 2V and 0 if envelope detector output is less than 2V • For a 1 followed by 0, the capacitor will discharge starting from 5V until output falls below 2 V and the comparator output will change to 0.
Demodulation Results (1) • Assuming the input is all 1’s, the amplitude of the modulated signal is always 5V. So the comparator output will always be 1.
Demodulation Results (2) • Assuming the input is a series of 1 followed by 0, the modulated signal amplitude will alternate between 5V and 1V. So we can model this case by applying an input signal of lower frequency to give the envelope detector enough time to discharge.
Future Improvements • Increasing power efficiency: • Matching antenna impedance • Improving the LPF and power amplifier • Including noise considerations in circuit design • Adding security codes to the transmitted signal • Using an advanced demodulation circuit to decode other types of modulated signals.
References • Han05 • Gerhard Hancke. A practical relay attack on ISO 14443 proximity cards, 2005. http://www.cl.cam.ac.uk/~gh275/relay.pdf. • Lee03 • Youbok Lee. Antenna circuit design for RFID application. Microchip Technology, Application Note AN710, DS00710C, 2003. http://ww1.microchip.com/downloads/en/AppNotes/00710c.pdf. • Sch05 • Bruce Schneier. RFID passport security revisited. Schneier on Security: A weblog covering security and security technology, 2005. http://www.schneier.com/blog/archives/2005/08/rfid_passport_s_1.html.
References • TI03 • S4100 multi-function reader module data sheet. Texas Instruments, Module 11-06-22-715, 2003. http://www.ti.com/rfid/docs/manuals/refmanuals/rf-mgr-mnmn_ds.pdf. • http://en.wikipedia.org/wiki/Bluetooth, 2006 • http://techtrain.microchip.com/webseminars/documents/IrDA_BW.pdf • http://trace.wisc.edu/docs/ir_intro/ir_intro.htm • http://en.wikipedia.org/wiki/Wi-fi#Wireless_Access_Point_.28WAP.29
Thank you Questions ?