Classifications

• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
  • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
  • G06K7/10009—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves
  • G06K7/10019—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers.
  • G06K7/10029—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. the collision being resolved in the time domain, e.g. using binary tree search or RFID responses allocated to a random time slot
  • G06K7/10059—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves resolving collision on the communication channels between simultaneously or concurrently interrogated record carriers. the collision being resolved in the time domain, e.g. using binary tree search or RFID responses allocated to a random time slot transponder driven
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
  • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
  • G06K7/0008—General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer

Definitions

• THIS invention relates to electronic identification (ID) systems and more
• RF radio frequency
• each transponder is mounted on a
• the reader broadcasts an energizing signal towards the transponders.
• the transponders derive power from the energizing signal and respond by
• (ID) code data The reader reads this data sequentially and identifies the
• transponders and hence identifies or counts the articles.
• the energizing signal may have an on to off duty cycle of less than 30%
• the data may be manipulated by, during the off parts, continuing to
• transponder by utilizing power provided by an energy store on the
• transponder to power data processing means on the transponder for
• the energy store may comprise a capacitor.
• the data processing means may comprise a random number generator
• capacitor is connected to at least the RNG, counter and clock.
• the data may be manipulated by, during the off parts, stopping a clock on a transponder, saving present data relating to
• the data may be manipulated by, during the off
• transponders are read according to a binary search procedure, the data
• the data may further be manipulated by saving in data processing means
• the data may be saved in a non-volatile memory arrangement of the
• transponder for example EEPROM.
• the data may be manipulated by, during the on parts,
• the data relating to an updated start value may relate to one of a seed
• RNG random number generator
• a reader for broadcasting a pulsed energizing signal having on and
• transponders each comprising means for generating
• the reader comprising means for reading output data transmitted by the transponders
• the system comprising data manipulating means for manipulating
• the data manipulating means may form part of a
• transponder and may be means for manipulating data generated by
• the data manipulating means may
• the data processing means may
• RNG random number generator
• the power storage means may be any type of power storage means.
• means may further comprise means for, at the commencement of an on period, to restart the clock and to cause the counter and counter
• transponder is read by a binary count procedure, the data manipulating
• manipulating means may comprise means for saving during the off parts
• a reader for broadcasting a pulsed energizing signal having on
• the reader comprising means for reading transmitted output data
• the reader further comprising means for adjusting the interval data of selected transponders during on parts of the energizing signal.
• figure 1 is a block diagram of an electronic radio frequency
• figure 2 is a typical time diagram of a known system
• figure 3 is a block diagram of a first embodiment of a transponder
• figure 4 is a flow diagram of the operation of the transponder in
• figure 5 is a time diagram of a pulsed sampling system comprising
• figure 6 is a block diagram of a second embodiment of a transponder
• figure 7 is a flow diagram of the operation of the transponder in
• figure 8 is a time diagram of a pulsed sampling identification system comprising transponders of the kind in figure 6;
• figure 9 is a block diagram of a third embodiment of a transponder
• figure 10 is a flow diagram of the operation of the transponder in
• figure 1 1 is a flow diagram of the operation of a reader cooperating
• figure 12 is a time diagram of the operation of a pulsed sampling
• figure 13 is a flow diagram of the operation according to the invention.
• figure 14 is a flow diagram of relevant parts of the operation
• figure 15 is a flow diagram of relevant parts of the operation
• transponder the operation of which is shown in figure 14.
• An electronic radio frequency (RF) identification (ID) system is generally designated by the reference numeral 10 in
• figure 1 figure 1 .
• the system comprises a reader or interrogator 12 which broadcasts an
• transponder is mounted on a respective article 20.1 to 20. n to be
• each transponder transmits a first response signal a
• transponder are spaced at random intertransmission intervals 28 between
• the hold off periods 24.1 to 24. n and intertransmission intervals 28 are
• RNG random number generators
• transponder population by broadcasting a pulsed energizing signal and the
• transponders #2 and #n will never be
• FIG 3 there is shown a first embodiment of a transponder according to
• the transponder comprises a logic
• control circuit 40 a Power on Reset (POR) signal generator circuit 42, a
• processing means 43 comprising a local clock 46, an RNG and associated
• capacitor 54 is connected to at least the
• generator 43 comprising the RNG and associated counter 48 and clock
• the logic control circuit 40 is sensitive to charge on
• a pulsed energizing signal is shown at 1 14 in figure 5.
• cycle of the energizing signal is smaller than 30% and typically in the
• the capacitor 54 provides power to enable the RNG and counter 48 and
• capacitor 54 has fallen below a threshold value, as shown at 66 (shown
• the transponder 1 18 comprises substantially
• the transponder in an ultra low power consumption mode.
• logic controller tests at 76 the voltage at point 56. If lower than a
• the RNG is loaded from memory 44, so that the RNG starts processing with the original seed data. However, if the voltage is a predefined threshold value, the RNG is loaded from memory 44, so that the RNG starts processing with the original seed data. However, if the voltage is a predefined threshold value, the RNG is loaded from memory 44, so that the RNG starts processing with the original seed data. However, if the voltage is a predefined threshold value, the RNG is loaded from memory 44, so that the RNG starts processing with the original seed data. However, if the voltage is
• the logic controller 40 assumes that the
• energizing signal is in an off part of its cycle and that they resume
• energizing signal 1 14 would appear to be continuous.
• transponder #2 would have responded with signal 80 shown in
• the signal 1 14 is backscatter modulated with the ID data of
• transponder #2 so that it may be read by reader 12 in conventional
• the data decoder 90 enables a reader 12 (shown in figure 1 ) to change
• RNG seed data in a selected transponder or selected transponders In
• transponder #2 during the first pulse 1 14.1 of energizing signal T14, transponder #2
• transponder #1 has a bigger seed value
• transponder #1 by reader 12 via decoder 90 as shown at 91 in figure 1 1 .
• slotted Aloha system 10 when used in a sampling method of
• each transponder by a random selection
• each transponder is further configured to save during off parts of the
• transponder at least data relating to a last slot selected by the
• the transponder proceeds with its
• transponders 18.1 to 18.n in data processing during the read procedure of the data transmitted by the transponders.
• Figure 14 illustrates operation of a reader 12 using binary search
• a sample or on part timer is initialized at
• timer is checked at 134 to determine whether time-out has occurred. If
• part timer is set up, typically with a value nine times that of the on part
• the off part is timed out at 146 and when time-out has occurred
• Figure 15 illustrates operation of a transponder 18.1 to 18.n using binary
• the transponder receives an on part
• transponder are reset at 156. The transponder then continues to
• transponder becomes dormant and waits at 162 for power to be
• non-volatile memory arrangement of the transponder will change state at
• the memory status is uncertain and the transponder will continue at 1 54 as if a new search

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Artificial Intelligence (AREA)
• Computer Vision & Pattern Recognition (AREA)
• General Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Electromagnetism (AREA)
• General Health & Medical Sciences (AREA)
• Radar Systems Or Details Thereof (AREA)

Applications Claiming Priority (3)

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• 2002
  • 2002-11-07 WO PCT/ZA2002/000168 patent/WO2003040998A1/en not_active Application Discontinuation
  • 2002-11-07 EP EP02782413A patent/EP1468394A1/de not_active Withdrawn

Non-Patent Citations (1)

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