CA1165427A - Electronic identification system - Google Patents
Electronic identification systemInfo
- Publication number
- CA1165427A CA1165427A CA000370724A CA370724A CA1165427A CA 1165427 A CA1165427 A CA 1165427A CA 000370724 A CA000370724 A CA 000370724A CA 370724 A CA370724 A CA 370724A CA 1165427 A CA1165427 A CA 1165427A
- Authority
- CA
- Canada
- Prior art keywords
- coded signal
- transmitter
- interrogation
- signal
- trigger circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B61—RAILWAYS
- B61L—GUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC
- B61L25/00—Recording or indicating positions or identities of vehicles or vehicle trains or setting of track apparatus
- B61L25/02—Indicating or recording positions or identities of vehicles or vehicle trains
- B61L25/04—Indicating or recording train identities
- B61L25/048—Indicating or recording train identities using programmable tags
-
- 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
-
- G—PHYSICS
- G07—CHECKING-DEVICES
- G07C—TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
- G07C9/00—Individual registration on entry or exit
- G07C9/20—Individual registration on entry or exit involving the use of a pass
- G07C9/28—Individual registration on entry or exit involving the use of a pass the pass enabling tracking or indicating presence
-
- G—PHYSICS
- G08—SIGNALLING
- G08G—TRAFFIC CONTROL SYSTEMS
- G08G1/00—Traffic control systems for road vehicles
- G08G1/01—Detecting movement of traffic to be counted or controlled
- G08G1/017—Detecting movement of traffic to be counted or controlled identifying vehicles
Abstract
ABSTRACT OF THE DISCLOSURE
An electronic identification system is disclosed for remote identification of an object. The system may be used for identifying rail cars passing an interrogation station and has the ability of allowing a coded signal to be remotely programmed. The system includes in combination an electronic identification device located on the object, and at least one interrogation station located remotely from the object. The identification device comprises a code generator adapted to produce a predetermined coded signal representing identification of the object, the code generator having a remote means to program a programmable code memory representing the coded signal, a transmitter having a trigger circuit means which when triggered transmits the coded signal from the transmitter, a self sealing holder allowing field programming of the code generator, and a power source for the transmitter. The interrogation station comprises an interrogation signal source adapted to trigger the trigger circuit means in the trans-mitter, receiver means adapted to receive the coded signal from the transmitter, synchronization means between the trans-mitter and the receiver means and decoder means, and decoder means to decode the coded signal and produce an identification of the object.
An electronic identification system is disclosed for remote identification of an object. The system may be used for identifying rail cars passing an interrogation station and has the ability of allowing a coded signal to be remotely programmed. The system includes in combination an electronic identification device located on the object, and at least one interrogation station located remotely from the object. The identification device comprises a code generator adapted to produce a predetermined coded signal representing identification of the object, the code generator having a remote means to program a programmable code memory representing the coded signal, a transmitter having a trigger circuit means which when triggered transmits the coded signal from the transmitter, a self sealing holder allowing field programming of the code generator, and a power source for the transmitter. The interrogation station comprises an interrogation signal source adapted to trigger the trigger circuit means in the trans-mitter, receiver means adapted to receive the coded signal from the transmitter, synchronization means between the trans-mitter and the receiver means and decoder means, and decoder means to decode the coded signal and produce an identification of the object.
Description
~6~27 This invention relates to an iAentification system suitable for identifying objects from a remote interrogation station. More specifically, the invention provides an electronic identification device including a transmitter positioned on an object ~and a remote interrogation station including a receiver and dato processor, together with a means for remotely program-ming the transmitter with transient information.
There is a need for an identification system wherein moving ob~ects such as railroad cars passing an interrogation station identify themselves for both accounting and control purposes. Such a system would also be applicable to boats, trucks, shipping containers, mailbags, pallets, etc. As well as these commercial applications, there is also a need for an identifica-tion system for monitoring animals in their natural habitat, including both fish and birds. The system could be applicable for identification of humans for control and security purposes, the identification of livestock and many other uses. In addition to the above uses, the ability to read, write, delete or modify data in a digital form makes the system applicable to a variety of uses, an example of which is a credit card. In this case the system serves as a portable interrogatable memory for information such as a credit balance.
One such system that exists for the identification of railroad cars includes labels located on the side of a car and a label reader station located beside the railroad track. Un-fortunately, the labels tend to become covered in dirt, and inaccurate readings of the labels occur.
The present invention provides an automatic identifica-tion system which does not rely on reading a label, but relies on remote or non-contacting sensing of the identity and other pertinent characteristics relating to a railroad car or other object. The identity is transmitted in a computer compatible - 1 - ~
1 ~542~
format for storage or transmission by existing data communication systems. Means is also provided for storing and reading transient information such as the current weight or contents of the railroad car.
The electronic identification system of the present invention has a transmitter located on the object with a trigger circuit operating on low power, Upon being triggered by a signal from a remote interrogation station, the transmitter transmits the data in a short series of transmissions, Power for the transmitter can be provided by a battery, inertial generator, electromagnetic radiation, induction, visible light or infrared, or by combinations of these power sources A continuous source of power is required if the remotely programmable feature is to be used. Moving objects can generate power for the transmitter from movement or vibration in a gravitational field. This technique can also be used to extend the life of a chemical power source.
The interrogation station, as well as sending a signal to trigger the trigger circuit, also has a receiver to receive the data from the object. The use of an absolute time source in the transmitter provides for synchronization between the trans-mitter and the receiver station and allows the use of a non-return to zero code format. Alternatively, a free-running clock can be used in the system and synchronization can be effected by choice of a suitable code format and appropriate processing in the decoding unit. This system has the additional advantage of allowing the clock oscillator to be gated off between interrogations with further savings in quiescent power consumption.
Selection of a data transfer rate for the transmitter can be made to allow for the movement velocity between the object to be identified and the interrogation station.
In one embodiment railroad freight cars are identified 1 165~27`
by the system Each car has an electronlc identificatlon device which includes a code generator to produce a coded signal pro-gran~ed to identify the car owner, car type, serial number, tare weight and maximum bearing class or gross weight. In additio~, a programmable memory device which allows storage of car contents or other transient information is included. The transmitter transmits this coded signal to the receiver in the interrogation station where parity techniques are used to determine the accuracy of the data transmitted. In one embodiment, 64 binary bits are used in the coded signal. The system is designed to ~ ~6~4~7`
allow for field programming of the fixed information ln the coded signal without violation of the mechanical integrity or sealing of the transmitter. Transient information is programmed via the interrogation source. An antenna is provided for the transmitter embedded in the unit to provide a broad radiation pattern. Interrogation of freight car identity is possible from either side of the car. Thè system operation can be automatically verified prior to receiving identity data. Decoding and data processing can be accomplished at the receiver by statistical determination of the "one" or "zero" bit.
Humans and animals can be identified by this technique and characteristics unique to each individual can be included with the coded signal so that identification can be confirmed.
The present invention provides an electronic identi-fication system for remote identification of an object including in combination an electronic identification device located on the object, and at least one interrogation station located re-motely from the object, the electronic identification device comprises a code generator adapted to produce a predetermined coded signal representing identification of the object, the code generator having a remote means to program a programmable code memory representlng the coded signal, a transmitter having a trigger circuit means which when triggered transmits the coded signal from the transmitter, and a power source ~or the trans-mitter; the interrogation station comprises an interrogation signal source adapted to trigger the trigger circuit means in the transmitter, receiver means adapted to receive the coded signal from the transmitter, synchronization means between the transmitter and the receiver means, and decoder means to decode the coded signal and produce identification of the object.
In other embodiments of the invention the object is a moving object such as a railroad car moving past an interroga-1 ~6~42~
tion station located on either side of the railroad track. The trigger circuit has a first antenna to pick up the interrogation signal and a second antenna is provided to transmit the coded signal from the transmitter. An absolute time source such as a clock is provided in the transmitter and a synchronized time source or clock in the receiver.
In still further embodiments the code generator is a replaceable fusible link diode matrix frame of 8 rows of 8 binary bits and 8 columns of 8 binary bits to provide 64 binary bits, each bit programmed to give an indication of zero or one. One row and one column of bits are used for parity checks to provide an error detecting and correcting means for the coded signal. An additional memory circuit remotely programmable by the trigger means is also provided.
There is also provided in the present invention a process for remotely identifying an object, comprising the steps of transmitting an interrogation signal from an interrogation station remote from the object, triggering a trigger circuit to transmit a predetermined coded signal from the object, the signal representing identification of the object, synchronizing the coded signal from an absolute time source on the object, with a receiver at the interrogation station to transmit the coded signal within a predetermined time period, and decoding the signal àt the interrogation station to produce an identification of the object.
In drawings which illustrate embodiments of the invention, Fig. 1 is a simple block diagram illustrating the electronic identification device and the interrogation station of the present invention.
Fig. 2 is a schematic diagram illustrating one embodi-ment of a power source derived from vibrational movement.
~ 1 ~5 '~ '2~
Fig, 3 is a diagrammatic re~resentation o~ a single transmission matrix frame, Fig. 4 is a diagrammatic representation of a complete transmission.
Fig. 5 is a sectional side view of one embodiment of a holder for the diode matrix.
Fig. 6 is a block diagram of a code generator in the transmitter, Fig. 7 is a schematic diagram of a microwave trigger circuit, Fig. 8 is a sectional side view of a patch antenna.
Fig. 9 is a top view of the patch antenna shown in Fig. 7.
_ 4A -1 165~2~
Fig,10 is a block diagram of an interrogation ~tation.
Fig. 11 is a block diagram showing the coded signal receiver in the interrogation station.
Referring now to Fig. 1, the components of the elec-tronic identification system include an electronic identification device 10 and an interrogation station 11. The identification device 10 includes a power source 12, a code generator 13, a trigger circuit 14 with a first antenna 15 and a radio frequency transmitter 16 and a second antenna 17. The interrogation station 11 includes a receiver 18 with an antenna 19, a decoder 20, a data processor 21, and an interrogation signal source 22 with an antenna 23. The data processor 21 aids in the decoding process, formats the data for communication with a central data processing unit (not shown) and generally controls the various functions of the interrogation station 11. In general, the complexity of the data processor 21 depends on the particular function which the whole identification system is required to perform.
The power source 12 for operation of the identification device 10 may be provided externally so that power is either stored or transferred to the transmitter 16 prior to the time at which the identification of the object is required. Power may be derived from the environment, or it may be provided as part of the interrogation procedure through the generation of an energy field, or it may be supplied by a battery source. It is characteristic of the invention that very small energy levels, on the order of millijoules, are required for transmission of the coded signal from the identification device 10 to the receiver 18. In one embodiment of the invention the object requiring identification is in motion, and a means for producing power for data transmission is to develop power from the inertial field.
This is particularly true for railroad freight cars, vehicles and 1 165427`
boats, for which the present invention is especially ~uitable.
It may be advantagaous to combine two or more power sources, such as a chemical battery and inertial energy generator or a battery and a solar generator.
The following description of the invention applies to the identification of railway freight cars but it will be obvious that the principle can be applied to the general problem OI non-contact automatic identification of any moving object, such as aD animal.
Fig. 2 illustrates an inertial energy generator where power is derived from the vibration or vertical movement of a railroad car or other moving objeet. ~ Typ~ca~ v~r3tional acceleration from the rolling wheels ~f a railraod car at low speeds is on the order of 0.1 g in a broad spectrum of frequencies.
A small mass 30 is shown mounted in the car frame 31 on one end of a resilient strip 32. Piezoelectric material 33 is bonded to each side of the strip 32, and movement of the mass 30 causing deflection of the strip 32 generates an alternating voltage.
Leads 34 from the piezoelectric material 33 feed to a circuit where rectification and doubling of the voltage is performed by the diodes 35, 36 and the energy storage capacltors 37, 38.
Alternatively, an ordinary full-wave or half-wave rectifier may be used if the higher voltage is not required. The direct current energy can either be stored in the capacitors 37, 38 or in a re-chargeable battery 39, but for long-term use the capacitor storage is preferred to av~id maintenance problems. A means of limiting the maximum voltage is provided in the form of a zener diode 40 or by a number of diodes in series, or by a voltage regulator circuit. A solar cell axray may be used in conjunction w ith the inertial energy generator or with a "keep alive" battery 39 so that railroad cars that have not moved enough to store sufficient electrical energy to power the identification device 10 may be 1 16~42'~
provided with the required energy quickly. In the case where a remotely programmable memory is used, the contents of the memory is maintained by a constant power source, such as a battery. Alternatively, an infrared source or an induction coil may be used in place of, or in con~unction with, the inertial generator and power induced by an induced energy field. Another alternative is the use of radio frequency energy induced from an external source through an antenna. A combination of a solar generator with energy storage capacitors and a "keep alive"
battery may also be used to provide power to transmit a coded signal representing a vehicle passing a particular location. In this case the identification device ~ld be placed in such a - location that the trigger circuit would be triggered by the moving vehicle.
The power source 12 must be capable of providing sufficient energy to the transmitter 16 so that the coded signal is completely transmitted before the stored power drops low enough to stop the data transmission. Prior to triggering the data transmission, the transmitter 16 draws a minimum current from the power source 12 so that the energy leaving the power source is less than the energy being accumulated. It is a feature of the code generator 13 and trigger circuit 14 that a quiescent current on the order of 1 or 2 microàmperes maintains the trans-mitter 16 in a "ready" state prior to interrogation and operate an absolute time source such as a clock in the code generator 13 of the identification device 10.
The data to be transmitted from the identification device 10 must be formatted in such a way that the desired information is conveyed as accurately as possible. While the following scheme is the preferred embodiment for marking railroad cars, a number of variations are possible. In general, the data will contain coded information to designate the owner of the car, 1 16~4~7 the car serial number, the tare weight, the load limit and possible characteristics of the car. The capacity o~ the code 27`
generator 1~ typically 64 blts of blnary data, It i6 convenlent to con~lder the data in terms of a frnme of 8 rows of 8 blts each and 8 ~olumns of 8 blts each as shown in Fig. 3.
An error detectlng and correcting system are lncluded in con~unction with blnary data. Each row and column is composed oi ~ data bits and one parity bit as shown in figure 3 where D
indicates data and P indicates parity. ~he 7 data bits in each column are associated with parity bits-P8and P15. If for example, data bit D24 ls transmitted in error as "one" ~nstead of "zero", then both parity bits P4 and Plo read incorrectly, i.e. they add up to one instead of zero, and a correction to data bit D24 is automatically made as part oi the decoding logic. Only one error can be detected and corrected in a frame. Each frame must ~atisfy the following rules: ¦
1. Exclusive-OR combinations of each row in the matrix must be zero.
There is a need for an identification system wherein moving ob~ects such as railroad cars passing an interrogation station identify themselves for both accounting and control purposes. Such a system would also be applicable to boats, trucks, shipping containers, mailbags, pallets, etc. As well as these commercial applications, there is also a need for an identifica-tion system for monitoring animals in their natural habitat, including both fish and birds. The system could be applicable for identification of humans for control and security purposes, the identification of livestock and many other uses. In addition to the above uses, the ability to read, write, delete or modify data in a digital form makes the system applicable to a variety of uses, an example of which is a credit card. In this case the system serves as a portable interrogatable memory for information such as a credit balance.
One such system that exists for the identification of railroad cars includes labels located on the side of a car and a label reader station located beside the railroad track. Un-fortunately, the labels tend to become covered in dirt, and inaccurate readings of the labels occur.
The present invention provides an automatic identifica-tion system which does not rely on reading a label, but relies on remote or non-contacting sensing of the identity and other pertinent characteristics relating to a railroad car or other object. The identity is transmitted in a computer compatible - 1 - ~
1 ~542~
format for storage or transmission by existing data communication systems. Means is also provided for storing and reading transient information such as the current weight or contents of the railroad car.
The electronic identification system of the present invention has a transmitter located on the object with a trigger circuit operating on low power, Upon being triggered by a signal from a remote interrogation station, the transmitter transmits the data in a short series of transmissions, Power for the transmitter can be provided by a battery, inertial generator, electromagnetic radiation, induction, visible light or infrared, or by combinations of these power sources A continuous source of power is required if the remotely programmable feature is to be used. Moving objects can generate power for the transmitter from movement or vibration in a gravitational field. This technique can also be used to extend the life of a chemical power source.
The interrogation station, as well as sending a signal to trigger the trigger circuit, also has a receiver to receive the data from the object. The use of an absolute time source in the transmitter provides for synchronization between the trans-mitter and the receiver station and allows the use of a non-return to zero code format. Alternatively, a free-running clock can be used in the system and synchronization can be effected by choice of a suitable code format and appropriate processing in the decoding unit. This system has the additional advantage of allowing the clock oscillator to be gated off between interrogations with further savings in quiescent power consumption.
Selection of a data transfer rate for the transmitter can be made to allow for the movement velocity between the object to be identified and the interrogation station.
In one embodiment railroad freight cars are identified 1 165~27`
by the system Each car has an electronlc identificatlon device which includes a code generator to produce a coded signal pro-gran~ed to identify the car owner, car type, serial number, tare weight and maximum bearing class or gross weight. In additio~, a programmable memory device which allows storage of car contents or other transient information is included. The transmitter transmits this coded signal to the receiver in the interrogation station where parity techniques are used to determine the accuracy of the data transmitted. In one embodiment, 64 binary bits are used in the coded signal. The system is designed to ~ ~6~4~7`
allow for field programming of the fixed information ln the coded signal without violation of the mechanical integrity or sealing of the transmitter. Transient information is programmed via the interrogation source. An antenna is provided for the transmitter embedded in the unit to provide a broad radiation pattern. Interrogation of freight car identity is possible from either side of the car. Thè system operation can be automatically verified prior to receiving identity data. Decoding and data processing can be accomplished at the receiver by statistical determination of the "one" or "zero" bit.
Humans and animals can be identified by this technique and characteristics unique to each individual can be included with the coded signal so that identification can be confirmed.
The present invention provides an electronic identi-fication system for remote identification of an object including in combination an electronic identification device located on the object, and at least one interrogation station located re-motely from the object, the electronic identification device comprises a code generator adapted to produce a predetermined coded signal representing identification of the object, the code generator having a remote means to program a programmable code memory representlng the coded signal, a transmitter having a trigger circuit means which when triggered transmits the coded signal from the transmitter, and a power source ~or the trans-mitter; the interrogation station comprises an interrogation signal source adapted to trigger the trigger circuit means in the transmitter, receiver means adapted to receive the coded signal from the transmitter, synchronization means between the transmitter and the receiver means, and decoder means to decode the coded signal and produce identification of the object.
In other embodiments of the invention the object is a moving object such as a railroad car moving past an interroga-1 ~6~42~
tion station located on either side of the railroad track. The trigger circuit has a first antenna to pick up the interrogation signal and a second antenna is provided to transmit the coded signal from the transmitter. An absolute time source such as a clock is provided in the transmitter and a synchronized time source or clock in the receiver.
In still further embodiments the code generator is a replaceable fusible link diode matrix frame of 8 rows of 8 binary bits and 8 columns of 8 binary bits to provide 64 binary bits, each bit programmed to give an indication of zero or one. One row and one column of bits are used for parity checks to provide an error detecting and correcting means for the coded signal. An additional memory circuit remotely programmable by the trigger means is also provided.
There is also provided in the present invention a process for remotely identifying an object, comprising the steps of transmitting an interrogation signal from an interrogation station remote from the object, triggering a trigger circuit to transmit a predetermined coded signal from the object, the signal representing identification of the object, synchronizing the coded signal from an absolute time source on the object, with a receiver at the interrogation station to transmit the coded signal within a predetermined time period, and decoding the signal àt the interrogation station to produce an identification of the object.
In drawings which illustrate embodiments of the invention, Fig. 1 is a simple block diagram illustrating the electronic identification device and the interrogation station of the present invention.
Fig. 2 is a schematic diagram illustrating one embodi-ment of a power source derived from vibrational movement.
~ 1 ~5 '~ '2~
Fig, 3 is a diagrammatic re~resentation o~ a single transmission matrix frame, Fig. 4 is a diagrammatic representation of a complete transmission.
Fig. 5 is a sectional side view of one embodiment of a holder for the diode matrix.
Fig. 6 is a block diagram of a code generator in the transmitter, Fig. 7 is a schematic diagram of a microwave trigger circuit, Fig. 8 is a sectional side view of a patch antenna.
Fig. 9 is a top view of the patch antenna shown in Fig. 7.
_ 4A -1 165~2~
Fig,10 is a block diagram of an interrogation ~tation.
Fig. 11 is a block diagram showing the coded signal receiver in the interrogation station.
Referring now to Fig. 1, the components of the elec-tronic identification system include an electronic identification device 10 and an interrogation station 11. The identification device 10 includes a power source 12, a code generator 13, a trigger circuit 14 with a first antenna 15 and a radio frequency transmitter 16 and a second antenna 17. The interrogation station 11 includes a receiver 18 with an antenna 19, a decoder 20, a data processor 21, and an interrogation signal source 22 with an antenna 23. The data processor 21 aids in the decoding process, formats the data for communication with a central data processing unit (not shown) and generally controls the various functions of the interrogation station 11. In general, the complexity of the data processor 21 depends on the particular function which the whole identification system is required to perform.
The power source 12 for operation of the identification device 10 may be provided externally so that power is either stored or transferred to the transmitter 16 prior to the time at which the identification of the object is required. Power may be derived from the environment, or it may be provided as part of the interrogation procedure through the generation of an energy field, or it may be supplied by a battery source. It is characteristic of the invention that very small energy levels, on the order of millijoules, are required for transmission of the coded signal from the identification device 10 to the receiver 18. In one embodiment of the invention the object requiring identification is in motion, and a means for producing power for data transmission is to develop power from the inertial field.
This is particularly true for railroad freight cars, vehicles and 1 165427`
boats, for which the present invention is especially ~uitable.
It may be advantagaous to combine two or more power sources, such as a chemical battery and inertial energy generator or a battery and a solar generator.
The following description of the invention applies to the identification of railway freight cars but it will be obvious that the principle can be applied to the general problem OI non-contact automatic identification of any moving object, such as aD animal.
Fig. 2 illustrates an inertial energy generator where power is derived from the vibration or vertical movement of a railroad car or other moving objeet. ~ Typ~ca~ v~r3tional acceleration from the rolling wheels ~f a railraod car at low speeds is on the order of 0.1 g in a broad spectrum of frequencies.
A small mass 30 is shown mounted in the car frame 31 on one end of a resilient strip 32. Piezoelectric material 33 is bonded to each side of the strip 32, and movement of the mass 30 causing deflection of the strip 32 generates an alternating voltage.
Leads 34 from the piezoelectric material 33 feed to a circuit where rectification and doubling of the voltage is performed by the diodes 35, 36 and the energy storage capacltors 37, 38.
Alternatively, an ordinary full-wave or half-wave rectifier may be used if the higher voltage is not required. The direct current energy can either be stored in the capacitors 37, 38 or in a re-chargeable battery 39, but for long-term use the capacitor storage is preferred to av~id maintenance problems. A means of limiting the maximum voltage is provided in the form of a zener diode 40 or by a number of diodes in series, or by a voltage regulator circuit. A solar cell axray may be used in conjunction w ith the inertial energy generator or with a "keep alive" battery 39 so that railroad cars that have not moved enough to store sufficient electrical energy to power the identification device 10 may be 1 16~42'~
provided with the required energy quickly. In the case where a remotely programmable memory is used, the contents of the memory is maintained by a constant power source, such as a battery. Alternatively, an infrared source or an induction coil may be used in place of, or in con~unction with, the inertial generator and power induced by an induced energy field. Another alternative is the use of radio frequency energy induced from an external source through an antenna. A combination of a solar generator with energy storage capacitors and a "keep alive"
battery may also be used to provide power to transmit a coded signal representing a vehicle passing a particular location. In this case the identification device ~ld be placed in such a - location that the trigger circuit would be triggered by the moving vehicle.
The power source 12 must be capable of providing sufficient energy to the transmitter 16 so that the coded signal is completely transmitted before the stored power drops low enough to stop the data transmission. Prior to triggering the data transmission, the transmitter 16 draws a minimum current from the power source 12 so that the energy leaving the power source is less than the energy being accumulated. It is a feature of the code generator 13 and trigger circuit 14 that a quiescent current on the order of 1 or 2 microàmperes maintains the trans-mitter 16 in a "ready" state prior to interrogation and operate an absolute time source such as a clock in the code generator 13 of the identification device 10.
The data to be transmitted from the identification device 10 must be formatted in such a way that the desired information is conveyed as accurately as possible. While the following scheme is the preferred embodiment for marking railroad cars, a number of variations are possible. In general, the data will contain coded information to designate the owner of the car, 1 16~4~7 the car serial number, the tare weight, the load limit and possible characteristics of the car. The capacity o~ the code 27`
generator 1~ typically 64 blts of blnary data, It i6 convenlent to con~lder the data in terms of a frnme of 8 rows of 8 blts each and 8 ~olumns of 8 blts each as shown in Fig. 3.
An error detectlng and correcting system are lncluded in con~unction with blnary data. Each row and column is composed oi ~ data bits and one parity bit as shown in figure 3 where D
indicates data and P indicates parity. ~he 7 data bits in each column are associated with parity bits-P8and P15. If for example, data bit D24 ls transmitted in error as "one" ~nstead of "zero", then both parity bits P4 and Plo read incorrectly, i.e. they add up to one instead of zero, and a correction to data bit D24 is automatically made as part oi the decoding logic. Only one error can be detected and corrected in a frame. Each frame must ~atisfy the following rules: ¦
1. Exclusive-OR combinations of each row in the matrix must be zero.
2. Exclusive-OR combinations of each column in the `
matrix must be zero.
These rules provide a set of logic equations which enable !
an error to be detected and corrected by a software program. If the number of errors transmitted exceeds the number of logic equations, the program indicates that the frame is in error, Data bits can be coded in various ways. For North American railroad applications, where cars associated with various owners are intermixed, a code is allocated to the frame as follows:
14 bits: represent car owner and bearing grade.
21 bits: represent car serial nu~ber and body type.
14 bits: represent tare weight, etc.
Since the type or grade of bearing determines the maximum load limit, it is clear that 49 data bits provides the necessary information to enable efficient management, control and accounting of all of the rolling stock in use in the North 1 lG5 427`
~merican system. In other rail systems where, for example, cars belonging to different owners do not intermix, or where other criteria such as the number of axles on each car are important, appropriate assignment of a code to the data is made.
When the interrogation system is applied in other ways, such as in the identification of persons for security control, different bits of the frame are assigned a code so that each person can be identified with a unique number. The remainder of the frame represents a unique characteristic identification of the person, such as his finger print pattern. These patterns have been demonstrated to be genetically determined and invariant with age and it is generally accepted that no two persons have the same finger print pattern. Various degrees of accuracy can be employed in representing these patterns in the binary code genera-tor of the identification device. As an example, consider that the patterns on the end phalange of the fingers and thumbs are described by six designations: "arch", "tented arch", "radial loop", "ulnar loop", "whorl" and "composite", where-the term composite refers to combinations of any of the previous terms.
The six print patterns can be described with three binary bits and consequently 30 bits or fewer would provide a representation of the generalized print pattern for two hands. The chance that two persons would be represented by the same binary code is 1 in 60,466,176.
In some applications, such as the electronic identifi-cation of animals, signalment features such as colour patterns, hair whorl patterns or genetic markers in the blood would serve a similar purpose. In many other applications it would be suff~-cient to encode only a serial number and its associated parity information.
The data code stream contains either a means of self synchronization such as a "return to zero" (RZ) code format, or 1 1~5~7 an ~xternal or inherent methoà of synchronization is provided.
In one embodiment synchronization in some form is provided at the interrogation station to clock the identification device.
An alternative solution is to provide an absolute time source such as a clock with the identification device, the clock being stable enough so that synchronization of a second independent clock in the interrogation station is maintained within a single bit for the period of time required to transmit the coded signal.
The availability of the low cost accurate timing crystals for wristwatch manufacture make the use of a non-return to zero (NRZ) code feasible since the timing is predictable enough for data recovery.
To further improve the reliability of the data transfer, each frame is sent 3 times along with one frame of sequential l's and O's to allow the decoding circuitry to accurately synchronize the clock rate. In cases where it is required to recover previously stored transient data, a second appropriately timed interrogation pulse is sent and this causes the third data frame to contain the transient data rather than the fixed data.
Figure 4 depicts the format of a complete coded signal trans-mission. Data frame No:3 can be either the fixed or transient data depending on the interrogation sequence.
r~ o~/
In the rai'lraod application, a minimum of 20 ft.
~ ,.
(6.1 m~ spacing of identification devices on adjacent cars can be assumed. At a speed of 180 mph (290 kph), this allows approxi-mately 75 milliseconds for a complete coded signal transmission.
In order to send the 256 bits, a bit time of 75/256 = 292 micro-seconds is required. To allow some spacing between transmissions, a bit time of 244.14 microseconds was chosen, requiring a clock rate of 4.096 KHz, conveniently derived from a 32.768 KHz watch crystal. A "1" is therefore a 244 microseconds RF burst, and a complete coded signal transmission requires approximately 62.5 1 ~6~2~
millisecond~.
A further requirement in the railroad and many other applications is field programmability of the fixed data in the code generator. For the railways, this is desirable for two reasons: In the first place it is difficult to organize the logistics of an initial coded generator installation if only factory programmed units were available; secondly, servicing of freight cars often changes their tare weight, which would have to be updated when such services were performed. It is there-fore characteristic of the present invention that a field programmable code generator is incorporated into the identifi-cation device.
In addition to the desirability of being able to program the code generator in various locations, it is also important that the identification device maintain a sealed con-dition. To achieve this, a holder for the diode matrix is provided. The holder which is illustrated in Fig. 5 allows easy insertion of the diode matrix 41 to be supported by two matrix pins 42 in a matrix mount 43 within the holder 44. -The holder 44 is attached to the circuit board 45 by two screws 46 and the conductor 47 is located on top of the circuit board 45.
A fastening screw 48 is shown at the end of the matrix mount 4~.
The holder 44 provides a moisture proof seal for the diode matrix 41. Although only one embodiment is shown, other embodi-ments may be provided and in some cases in-circuit programming of the diode matrix may be achieved.
A block diagram of the code generator is shown in Figure 6. The code generator comprise blocks of logic circuits which are in common use and would be familiar to those skilled in the art. To achieve the very low current consumption required, however, the entire identification device excluding the diode array 50 is realized in a sing~e CMOS integrated 1 165~2~
circuit. Its operation is as follows:
In response to a trigger impulse 51 the flip-flop 52 ls reset and the counters 53 to 57 and auxiliary counter 64 are allowed to count. Counter 54 and selector 58 sequentially select columns of diodes and counter 55 and selector 59 select rows of diodes. This produces a code input to transmission gate 60. During the first 64 counts at the clock input of counter 54, the output of N~R gate 61 is high. This enables transmlssion gate 62 to pass a 15.625 millisecond preamble to the code output 63. ~uring the next 128 counts, transmission gate 60 allows code to the code output 63. If a second trigger pulse is received after exactly, say 17 clo~-. p~ll~es, then decode No: 17 (65) sets flip-flop 66 so that during the next 64 counts the output of the 64 bit recirculating shift register 67 becomes the code output. If the second trigger pulse is not sent, the code output 63 is still from the diode matrix 53.
After 256 counts, flip-flop 52 is reset and all counters are inhibited. In order to load the shift register 67, then another trigger pulse is sent after, say 37 clock pulses, and decode No:37 (68) sets flip-flop 69. Subsequent "ones" and "zeros"
at the trigger input are then loaded into the shift register 67.
The trigger circuit 14 may take one of several forms depending on a specific application. The characteristics of the trigger circuit are as follows:
1. High input impedance.
2. A threshold level of voltage must be exceeded in order to initiate the transmission.
matrix must be zero.
These rules provide a set of logic equations which enable !
an error to be detected and corrected by a software program. If the number of errors transmitted exceeds the number of logic equations, the program indicates that the frame is in error, Data bits can be coded in various ways. For North American railroad applications, where cars associated with various owners are intermixed, a code is allocated to the frame as follows:
14 bits: represent car owner and bearing grade.
21 bits: represent car serial nu~ber and body type.
14 bits: represent tare weight, etc.
Since the type or grade of bearing determines the maximum load limit, it is clear that 49 data bits provides the necessary information to enable efficient management, control and accounting of all of the rolling stock in use in the North 1 lG5 427`
~merican system. In other rail systems where, for example, cars belonging to different owners do not intermix, or where other criteria such as the number of axles on each car are important, appropriate assignment of a code to the data is made.
When the interrogation system is applied in other ways, such as in the identification of persons for security control, different bits of the frame are assigned a code so that each person can be identified with a unique number. The remainder of the frame represents a unique characteristic identification of the person, such as his finger print pattern. These patterns have been demonstrated to be genetically determined and invariant with age and it is generally accepted that no two persons have the same finger print pattern. Various degrees of accuracy can be employed in representing these patterns in the binary code genera-tor of the identification device. As an example, consider that the patterns on the end phalange of the fingers and thumbs are described by six designations: "arch", "tented arch", "radial loop", "ulnar loop", "whorl" and "composite", where-the term composite refers to combinations of any of the previous terms.
The six print patterns can be described with three binary bits and consequently 30 bits or fewer would provide a representation of the generalized print pattern for two hands. The chance that two persons would be represented by the same binary code is 1 in 60,466,176.
In some applications, such as the electronic identifi-cation of animals, signalment features such as colour patterns, hair whorl patterns or genetic markers in the blood would serve a similar purpose. In many other applications it would be suff~-cient to encode only a serial number and its associated parity information.
The data code stream contains either a means of self synchronization such as a "return to zero" (RZ) code format, or 1 1~5~7 an ~xternal or inherent methoà of synchronization is provided.
In one embodiment synchronization in some form is provided at the interrogation station to clock the identification device.
An alternative solution is to provide an absolute time source such as a clock with the identification device, the clock being stable enough so that synchronization of a second independent clock in the interrogation station is maintained within a single bit for the period of time required to transmit the coded signal.
The availability of the low cost accurate timing crystals for wristwatch manufacture make the use of a non-return to zero (NRZ) code feasible since the timing is predictable enough for data recovery.
To further improve the reliability of the data transfer, each frame is sent 3 times along with one frame of sequential l's and O's to allow the decoding circuitry to accurately synchronize the clock rate. In cases where it is required to recover previously stored transient data, a second appropriately timed interrogation pulse is sent and this causes the third data frame to contain the transient data rather than the fixed data.
Figure 4 depicts the format of a complete coded signal trans-mission. Data frame No:3 can be either the fixed or transient data depending on the interrogation sequence.
r~ o~/
In the rai'lraod application, a minimum of 20 ft.
~ ,.
(6.1 m~ spacing of identification devices on adjacent cars can be assumed. At a speed of 180 mph (290 kph), this allows approxi-mately 75 milliseconds for a complete coded signal transmission.
In order to send the 256 bits, a bit time of 75/256 = 292 micro-seconds is required. To allow some spacing between transmissions, a bit time of 244.14 microseconds was chosen, requiring a clock rate of 4.096 KHz, conveniently derived from a 32.768 KHz watch crystal. A "1" is therefore a 244 microseconds RF burst, and a complete coded signal transmission requires approximately 62.5 1 ~6~2~
millisecond~.
A further requirement in the railroad and many other applications is field programmability of the fixed data in the code generator. For the railways, this is desirable for two reasons: In the first place it is difficult to organize the logistics of an initial coded generator installation if only factory programmed units were available; secondly, servicing of freight cars often changes their tare weight, which would have to be updated when such services were performed. It is there-fore characteristic of the present invention that a field programmable code generator is incorporated into the identifi-cation device.
In addition to the desirability of being able to program the code generator in various locations, it is also important that the identification device maintain a sealed con-dition. To achieve this, a holder for the diode matrix is provided. The holder which is illustrated in Fig. 5 allows easy insertion of the diode matrix 41 to be supported by two matrix pins 42 in a matrix mount 43 within the holder 44. -The holder 44 is attached to the circuit board 45 by two screws 46 and the conductor 47 is located on top of the circuit board 45.
A fastening screw 48 is shown at the end of the matrix mount 4~.
The holder 44 provides a moisture proof seal for the diode matrix 41. Although only one embodiment is shown, other embodi-ments may be provided and in some cases in-circuit programming of the diode matrix may be achieved.
A block diagram of the code generator is shown in Figure 6. The code generator comprise blocks of logic circuits which are in common use and would be familiar to those skilled in the art. To achieve the very low current consumption required, however, the entire identification device excluding the diode array 50 is realized in a sing~e CMOS integrated 1 165~2~
circuit. Its operation is as follows:
In response to a trigger impulse 51 the flip-flop 52 ls reset and the counters 53 to 57 and auxiliary counter 64 are allowed to count. Counter 54 and selector 58 sequentially select columns of diodes and counter 55 and selector 59 select rows of diodes. This produces a code input to transmission gate 60. During the first 64 counts at the clock input of counter 54, the output of N~R gate 61 is high. This enables transmlssion gate 62 to pass a 15.625 millisecond preamble to the code output 63. ~uring the next 128 counts, transmission gate 60 allows code to the code output 63. If a second trigger pulse is received after exactly, say 17 clo~-. p~ll~es, then decode No: 17 (65) sets flip-flop 66 so that during the next 64 counts the output of the 64 bit recirculating shift register 67 becomes the code output. If the second trigger pulse is not sent, the code output 63 is still from the diode matrix 53.
After 256 counts, flip-flop 52 is reset and all counters are inhibited. In order to load the shift register 67, then another trigger pulse is sent after, say 37 clock pulses, and decode No:37 (68) sets flip-flop 69. Subsequent "ones" and "zeros"
at the trigger input are then loaded into the shift register 67.
The trigger circuit 14 may take one of several forms depending on a specific application. The characteristics of the trigger circuit are as follows:
1. High input impedance.
2. A threshold level of voltage must be exceeded in order to initiate the transmission.
3. Trigger initiation is effected by an impulse rather than a steady state condition.
It is desirable that the trigger circuit 14 be passive in the sense that it requires a minimum of power, preferably no power in the quiescent state.
1 16542 ~
Energy may be provided as an interrogation signal in various forms such as electromagnetic, magnetic field or pressure In some applications, such as animal identification, an impulse of infrared light falling on a filtered photovoltaic cell array is selected. If it is desired to identify fish, an impulse or burst of ultrasonic energy may be used In the railroad environment, a burst of microwave radiation may be used as an interrogation signal. Figure 7 shows a trigger circuit suitable for receiving an interrogation signal 70 in the form of electromagnetic radiation, demodulating the burst with diodes 71 and capacitors 72 and matching the appropriate input impedance with a pulse transformer 73.
In one embodiment the trigger circuit may be made secure by requiring multiple triggering pulses with a technique such as described above for programming. The interrogation signal then produces a preset pattern of pulses, for example, three pulses.
1, 1 16~42~
The flrst pulse triggers the flrst pulse on the oscillator, the second pulse triggers say the thirteenth pulse on the oscillator, and the third pulse triggers say the thirty-first pulse on the oscillator. This preset arrangement of pulses then ~riggers the code generator to transmit the coded signal.
A "patch" antenna 74 is shown ln figures 8 and 9 and acts as a filter to restrict the stimulus energy to a narrow band of frequencies. The antenna 74 has a low loss dielectric body 75 with a conductlve top layer 76 extended down a shorted side 77 of the body 75. A coaxial feed line 78 is shown in Fig. 8, the feed line may be in the form of two strips 79 shown in Fig. 0. This configuration has a broad radiation pattern and is capable of being fabricated within or on the surface of an enclosure for the identification device. The dielectric body 75-is typically alumina ceramic but may be any suitable low loss dielectric material.
The interrogation signal source for providing a trigger signal from the interrogation station may also sense doppler movement of the moving railroad-car to derive speed and direction of movement.
The final functional block of the identification device 10 is the RF transmitter 16. In one embodiment, suitable for railroad application a low-power microwave transmitter is con-structed on an alumina substrate using a minimum of components.
Most components are constructed with thick film techniques. The operating frequency of the transmitter 16 is not critical.
Temperature compensation is applied to allow stable operation over a wide temperature range. In one embodiment the transmitter power output is below 10 milliwatts and the transmitter drives a "patch" antenna of the tgpe shown in figures 8 and 9. When a microwave interrogation signal source is used, a similar antenna at a frequency different than the coded signal link frequency is 1 16~42~
used, The transmitter 1~ comprises a single stage oscillator at the selected ope~ating frequency.
Figures ~ and ~ illustrate a more detailed arrange-ment of the interrogation station 11. The embodiment shown represents one possible configuration suitable for railroad appli-cations. Alternative interrogation stations and receiving antennas may just as well be employed.
Two microwave interrogator signal sources 80, 81 with antennas 82, 83 are sho~n, one on each side of a railroad track 84 to allow for identification devices on either side of the railroad cars. Four coded signal receivers 85 - 88 are pro-vided, two on each side of the track 84. Each receiver is shown in more detail in Fig. ~ and has an antenna 89, filter 90, RF amplifier 91, detector 92 and DC amplifier 93. Two receivers are provided on each side of the track 84 to allow for increased reliability and better antenna coverage. The RF filter 90 is tuned to the microwave transmitter frequency of the identification device and rejects unwanted signals, which are in any case un-likely to be found in this frequency band. The frequency is ~ 20 chosen to avoid atmospheric and man-made noise which is at a low `- level around 2500 MHz. The directional antennas 89 further I improve the situation in this regard. The antennas 89 are spaced - sufficiently far from the track 84 so that amplitude variations during a transmission are minimized.
After detection the DC amplifiers 93 increase the signal levels before transmitting them to the decoder and main processor. The multiple feed lines 94 provide further insurance against failure, The signals are amplified by limited amplifiers 95 before being applied to a combining circuit 96 which routes them to a microprocessor decoder 97. A "one" is entered into the decoder memory 98 for every "one" encountered, and a "zero" for every zero. A clock circuit provides "send'` and "receive"
1 16~427 synchronization. At this time, the stored pattern of l's and O's is transferred to the main processor 99, while the decoder 97 awaits the arrival of the next coded signal representing the next railroad car. Because multiple samples are taken for each bit, and these samples are averaged, a degree of noise can be tolerated before a given bit is incorrectly read. A check of the parity bits and a comparison between the 2 or 3 data frames can now be done, and a final best estimate of the coded signal transmission can be made.
When the main processor 99 has decoded one coded signal transmission, it is stored in its memory 100 and the next one is awaited. Wheel contacts indicate when the whole train has passed, and at this time the data is assembled into a format compatible with the central data processor, to which it is sent either in response to an interrogation or at its own request.
Since wheel contacts signal the arrival of a train, a system check is made prior to determining car identity data via an-analog-to-di.gital convertor~101. Various system voltages and the interrogation signal sources 80, 81 are monitored, and a test transmitter 102 is activated to allow a test to be made of the 4 receivers 85 - 88. Any abnormality at this point is noted and sent to the central data processor, Appropriate service action may then be taken.
Although only one specific embodiment of the system is disclosed herein in detail, it ~ill be apparent to those skilled in the art that variations may be made to both the identification device on the object, and the interrogation station to suit the particular requirements. If animals are to be monitored in their environment, the identification device is small and compact, and the interrogation station may be a portable unit suitable for installation in a plane, boat or other vehicle or even a hand held unit. Security systems for humans comprise an 1 165~2~
identification device that may be clipped to an individual, and an interrogation station that was programmed to open a gate to allow an individual to enter a particular area, or sound an alarm if the individual's identification device did not produce the correct coded signal.
It is desirable that the trigger circuit 14 be passive in the sense that it requires a minimum of power, preferably no power in the quiescent state.
1 16542 ~
Energy may be provided as an interrogation signal in various forms such as electromagnetic, magnetic field or pressure In some applications, such as animal identification, an impulse of infrared light falling on a filtered photovoltaic cell array is selected. If it is desired to identify fish, an impulse or burst of ultrasonic energy may be used In the railroad environment, a burst of microwave radiation may be used as an interrogation signal. Figure 7 shows a trigger circuit suitable for receiving an interrogation signal 70 in the form of electromagnetic radiation, demodulating the burst with diodes 71 and capacitors 72 and matching the appropriate input impedance with a pulse transformer 73.
In one embodiment the trigger circuit may be made secure by requiring multiple triggering pulses with a technique such as described above for programming. The interrogation signal then produces a preset pattern of pulses, for example, three pulses.
1, 1 16~42~
The flrst pulse triggers the flrst pulse on the oscillator, the second pulse triggers say the thirteenth pulse on the oscillator, and the third pulse triggers say the thirty-first pulse on the oscillator. This preset arrangement of pulses then ~riggers the code generator to transmit the coded signal.
A "patch" antenna 74 is shown ln figures 8 and 9 and acts as a filter to restrict the stimulus energy to a narrow band of frequencies. The antenna 74 has a low loss dielectric body 75 with a conductlve top layer 76 extended down a shorted side 77 of the body 75. A coaxial feed line 78 is shown in Fig. 8, the feed line may be in the form of two strips 79 shown in Fig. 0. This configuration has a broad radiation pattern and is capable of being fabricated within or on the surface of an enclosure for the identification device. The dielectric body 75-is typically alumina ceramic but may be any suitable low loss dielectric material.
The interrogation signal source for providing a trigger signal from the interrogation station may also sense doppler movement of the moving railroad-car to derive speed and direction of movement.
The final functional block of the identification device 10 is the RF transmitter 16. In one embodiment, suitable for railroad application a low-power microwave transmitter is con-structed on an alumina substrate using a minimum of components.
Most components are constructed with thick film techniques. The operating frequency of the transmitter 16 is not critical.
Temperature compensation is applied to allow stable operation over a wide temperature range. In one embodiment the transmitter power output is below 10 milliwatts and the transmitter drives a "patch" antenna of the tgpe shown in figures 8 and 9. When a microwave interrogation signal source is used, a similar antenna at a frequency different than the coded signal link frequency is 1 16~42~
used, The transmitter 1~ comprises a single stage oscillator at the selected ope~ating frequency.
Figures ~ and ~ illustrate a more detailed arrange-ment of the interrogation station 11. The embodiment shown represents one possible configuration suitable for railroad appli-cations. Alternative interrogation stations and receiving antennas may just as well be employed.
Two microwave interrogator signal sources 80, 81 with antennas 82, 83 are sho~n, one on each side of a railroad track 84 to allow for identification devices on either side of the railroad cars. Four coded signal receivers 85 - 88 are pro-vided, two on each side of the track 84. Each receiver is shown in more detail in Fig. ~ and has an antenna 89, filter 90, RF amplifier 91, detector 92 and DC amplifier 93. Two receivers are provided on each side of the track 84 to allow for increased reliability and better antenna coverage. The RF filter 90 is tuned to the microwave transmitter frequency of the identification device and rejects unwanted signals, which are in any case un-likely to be found in this frequency band. The frequency is ~ 20 chosen to avoid atmospheric and man-made noise which is at a low `- level around 2500 MHz. The directional antennas 89 further I improve the situation in this regard. The antennas 89 are spaced - sufficiently far from the track 84 so that amplitude variations during a transmission are minimized.
After detection the DC amplifiers 93 increase the signal levels before transmitting them to the decoder and main processor. The multiple feed lines 94 provide further insurance against failure, The signals are amplified by limited amplifiers 95 before being applied to a combining circuit 96 which routes them to a microprocessor decoder 97. A "one" is entered into the decoder memory 98 for every "one" encountered, and a "zero" for every zero. A clock circuit provides "send'` and "receive"
1 16~427 synchronization. At this time, the stored pattern of l's and O's is transferred to the main processor 99, while the decoder 97 awaits the arrival of the next coded signal representing the next railroad car. Because multiple samples are taken for each bit, and these samples are averaged, a degree of noise can be tolerated before a given bit is incorrectly read. A check of the parity bits and a comparison between the 2 or 3 data frames can now be done, and a final best estimate of the coded signal transmission can be made.
When the main processor 99 has decoded one coded signal transmission, it is stored in its memory 100 and the next one is awaited. Wheel contacts indicate when the whole train has passed, and at this time the data is assembled into a format compatible with the central data processor, to which it is sent either in response to an interrogation or at its own request.
Since wheel contacts signal the arrival of a train, a system check is made prior to determining car identity data via an-analog-to-di.gital convertor~101. Various system voltages and the interrogation signal sources 80, 81 are monitored, and a test transmitter 102 is activated to allow a test to be made of the 4 receivers 85 - 88. Any abnormality at this point is noted and sent to the central data processor, Appropriate service action may then be taken.
Although only one specific embodiment of the system is disclosed herein in detail, it ~ill be apparent to those skilled in the art that variations may be made to both the identification device on the object, and the interrogation station to suit the particular requirements. If animals are to be monitored in their environment, the identification device is small and compact, and the interrogation station may be a portable unit suitable for installation in a plane, boat or other vehicle or even a hand held unit. Security systems for humans comprise an 1 165~2~
identification device that may be clipped to an individual, and an interrogation station that was programmed to open a gate to allow an individual to enter a particular area, or sound an alarm if the individual's identification device did not produce the correct coded signal.
Claims (19)
1. An electronic identification system for remote identification of an object, including in combination an electronic identification device located on the object, and at least one interrogation station located remotely from the object, the electronic identification device comprises:
a code generator adapted to produce a predetermined coded signal representing identification of the object, the code generator having a remote means to program a programmable code memory representing the-coded signal, a transmitter having a trigger circuit means which when triggered transmits the coded signal from the transmitter;
and a battery power source for the transmitter;
the interrogation station comprises:
an interrogation signal source adapted to trigger the trigger circuit means in the transmitter, receiver means adapted to receive the coded signal from the transmitter, synchronization means between the transmitter and the receiver means, and decoder means to decode the coded signal and produce an identification of the object, said electronic identification device including a self sealing holder allowing field programming.
a code generator adapted to produce a predetermined coded signal representing identification of the object, the code generator having a remote means to program a programmable code memory representing the-coded signal, a transmitter having a trigger circuit means which when triggered transmits the coded signal from the transmitter;
and a battery power source for the transmitter;
the interrogation station comprises:
an interrogation signal source adapted to trigger the trigger circuit means in the transmitter, receiver means adapted to receive the coded signal from the transmitter, synchronization means between the transmitter and the receiver means, and decoder means to decode the coded signal and produce an identification of the object, said electronic identification device including a self sealing holder allowing field programming.
2. An electronic identification system for an object moving in a predetermined path including in combination an electronic identification device on the moving object, and at least one interrogation station adjacent the predetermined path, the electronic identification device comprising:
a code generator to produce a predetermined coded signal representing identification of the object, the code generator having a remote means to program a programmable code memory representing the coded signal, a transmitter having a trigger circuit means which when triggered transmits the coded signal, a self sealing holder allowing field programming of the code generator, a first antenna in the trigger circuit means adapted to pick up an interrogation signal, a second antenna adapted to transmit the coded signal from the transmitter, an absolute time source integral with the transmitter, and battery power source for the absolute time source, trigger circuit and transmitter;
The interrogation station comprising:
an interrogation signal source with an antenna adapted to trigger the trigger circuit means on the transmitter, a receiver means with an antenna adapted to receive the coded signal from the transmitter, a clock synchronized with the absolute time source in the transmitter to determine time of transmission of the coded signal, and decoder means to decode the coded signal and produce an identification of the object, said electronic identification device including a self sealing holder allowing field programming.
a code generator to produce a predetermined coded signal representing identification of the object, the code generator having a remote means to program a programmable code memory representing the coded signal, a transmitter having a trigger circuit means which when triggered transmits the coded signal, a self sealing holder allowing field programming of the code generator, a first antenna in the trigger circuit means adapted to pick up an interrogation signal, a second antenna adapted to transmit the coded signal from the transmitter, an absolute time source integral with the transmitter, and battery power source for the absolute time source, trigger circuit and transmitter;
The interrogation station comprising:
an interrogation signal source with an antenna adapted to trigger the trigger circuit means on the transmitter, a receiver means with an antenna adapted to receive the coded signal from the transmitter, a clock synchronized with the absolute time source in the transmitter to determine time of transmission of the coded signal, and decoder means to decode the coded signal and produce an identification of the object, said electronic identification device including a self sealing holder allowing field programming.
3. The system according to claim 1 wherein the code generator comprises a replaceable fusible link diode matrix frame of 8 rows of 8 binary bits and 8 columns of 8 binary bits to provide 64 binary bits, each bit programmed to give an indication of zero or one.
4. The system according to claim 3 wherein each row and each column has seven binary bits for data and one binary bit for parity to provide an error detecting and correcting means for the coded signal, by ensuring the frame satisfies the rules that exclusive - OR combinations in each row and each column must be zero.
5. The system according to claim 3 wherein the matrix frame may be programmed in the field by fusing out selected binary bits to the desired program.
6. The system according to claim 3 wherein the matrix frame may be inserted into a self sealing holder in the field when the matrix frame has been appropriately programmed.
7. The system according to claim 2 when used to identify railroad cars moving along a railroad track, each rail car having an electronic identification device programmed to produce a coded signal representing rail car owner, car serial number and type and tare weight.
8. The system according to claim 2 wherein the programmable code memory can be read by an interrogation sequence.
9. The system according to claim 2 wherein the means to program the programmable code memory includes a multi-pulse interrogation sequence.
10. The system according to claim 2 wherein the antennas in electronic identification device and the interroga-tion station are patch antennas.
11. The system according to claim 2 wherein the power source maintains a constant output of about 1 to 2 micro-amps to operate the absolute time source and maintain the trigger circuit ready to receive an interrogation signal prior to activation of the trigger circuit.
12. The system according to claim 1 wherein the trigger circuit means may be made secure by the interrogation signal producing a series of pulses in a preset pattern to trigger the trigger circuit means.
13. The system according to claim 7 wherein the coded signal is sent three times together with a frame of sequential pulses to accurately synchronize the clock and the absolute time source, and allow error reduction by cyclic re-dundancy.
14. The system according to claim 7 including at least one interrogation station on each side of the railroad track.
15. The system according to claim 7 wherein the receiver means adapted to receive the coded signal includes filters to reject unwanted signals.
16. The system according to claim 7 including wheel contact signal means to indicate arrival of each railroad car to an interrogation station.
17. The system according to claim 16 wherein the information relating to each rail car is stored in a memory until the wheel contact means indicates a complete train has passed the interrogation station.
18. The system according to claim 14 including a test transmitter adapted to produce a test coded signal, is located in a position so that the receiver in each of the interrogation stations can be tested.
19. A process for remotely identifying an object, comprising the steps of:
transmitting an interrogation signal from an interrogation station remote from the object, triggering a trigger circuit of an electronic identification device including a code generator to transmit a predetermined coded signal from the object, the signal re-presenting identification of the object, synchronizing the coded signal from an absolute time source on the object, with a receiver at the interroga-tion station, to transmit the coded signal within a predeter-mined time period, and decoding the signal at the interrogation station to produce an identification of the object, said process further comprising using a self sealing holder for field programming of the code generator.
transmitting an interrogation signal from an interrogation station remote from the object, triggering a trigger circuit of an electronic identification device including a code generator to transmit a predetermined coded signal from the object, the signal re-presenting identification of the object, synchronizing the coded signal from an absolute time source on the object, with a receiver at the interroga-tion station, to transmit the coded signal within a predeter-mined time period, and decoding the signal at the interrogation station to produce an identification of the object, said process further comprising using a self sealing holder for field programming of the code generator.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8004851 | 1980-02-13 | ||
| GB8004851 | 1980-02-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1165427A true CA1165427A (en) | 1984-04-10 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000370724A Expired CA1165427A (en) | 1980-02-13 | 1981-02-12 | Electronic identification system |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4870419A (en) |
| AU (1) | AU541815B2 (en) |
| CA (1) | CA1165427A (en) |
| NZ (1) | NZ196256A (en) |
| ZA (1) | ZA81888B (en) |
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- 1981-02-12 CA CA000370724A patent/CA1165427A/en not_active Expired
- 1981-02-13 NZ NZ196256A patent/NZ196256A/en unknown
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1988
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Also Published As
| Publication number | Publication date |
|---|---|
| US4870419A (en) | 1989-09-26 |
| AU541815B2 (en) | 1985-01-24 |
| AU6723781A (en) | 1981-08-20 |
| NZ196256A (en) | 1984-11-09 |
| ZA81888B (en) | 1982-03-31 |
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