US3303496A

US3303496A - Identification arrangement

Info

Publication number: US3303496A
Application number: US400473A
Authority: US
Inventors: Koorneef Jacob; Hertog Jacobus Marius Den
Original assignee: US Philips Corp
Current assignee: US Philips Corp; North American Philips Co Inc
Priority date: 1963-10-02
Filing date: 1964-09-30
Publication date: 1967-02-07
Anticipated expiration: 1984-02-07
Also published as: CH428834A; AT252313B; ES304522A1; NO120736B; GB1043809A; NL141134B

Description

1967 J. KOORNEEF ETAL 3,303,496

IDENTIFICATION ARRANGEMENT Filed se t.,so, 1964 2 Sheets-Sheet 1 BISTABLE TRIGGER AE I/AERIAL FREQUENCY GATE ZERO sET UIv pE I; .ZERO SET '1 f m 0 P5 TRANSMITTER 5D PULSE BE COUNTING COUNTING CIRCUIT f CIRCUIT COUNTING l A CIRCUIT icATcicefTIa Bc COINCIDENCE cIRCUITs LIMITING RECEIVING RECEIVER c AERIAL- SC BISTABLE TRIGGERS FC U BX E lkfigmg N- I RATIN 5M2! -BA 1 DELAY BB 'BH I VR II 1 LI m RECEIVING MG RECEIVER 5N PN AERIAL I 1 V I [-4- E -SHIFT REGISTER I I /BK CC I FIG? COINCIDENCE CIRCUIT INVENTORS JACOB KOORNEEF JACOBUS M. DEN HERTDG BY f A e P III/70M.

Feb. 7, 1967 J. KOORNEEF ETAL 3,303,496

IDENT IFI CAT ION ARRANGEMENT Filed Sept. 50, 1964 2 Sheets-Sheet 2 RECEIVING AERIAL I V CODE D|SC' READING HEAD RE GA csi FiGfic|||n1munlmuuluumluuunmmummummllmumlmlmm llllllllllllllllllllllllllllllllllllllll INVENTORj JACOB KOORNEEF? JACOBUS M. DEN HERTOG B M 6. ,qain r' United States Patent ()fifice 3,3@3,4% Patented Feb. 7, 1967 3,303,496 IDENTIFICATION ARRANGEMENT Jacob Koorneef and Jacobus Marius den Hertog, Em-

masingel, Eindhoven, Netherlands, assignors to North American Philips Company, Inc., New York, N.Y., a corporation of Delaware Filed Sept. 30, 1964, Ser. No. 400,473 Claims priority, application Netherlands, Oct. 2, 1963, 298,733 5 Claims. (Cl. 343-65) The invention relates to an arrangement for identifying articles, for example railway carriages or articles on a conveyor belt, movable with respect to a testing device.

The requirements which must be imposed in practice 'on an arrangement for identifying railway carriages are particularly stringent. Since a great amount of data is desired, the information supplied must consist of a code number of ten or more decimal digits. Each digit or each digit group has a given meaning and characterizes, for example, the country of origin, the stand, the number of the carriage, and so on. It must be possible to carry out identification at a low speed or standstill of the train and also at a speed of, for example, 160 kms. per hour, in which latter case the time available for the identification is very short. Neither the so-called buffering of the carriages, which cause these carriages to perform a reciprocating movement, nor the direction of movement of the train must exert any influence. For reasons of safety, the distance between the testing device and the train may not be smaller than, for example, 40 cms., while on the other hand, also in connection with the different widths of the carriages, the distance may even be 90 cms. As a matter of course, the arrangement must operate reliably under all conditions, including snow or glazed frost. Moreover, itis desirable that the identification apparatus on the carriages have small dimensions and be accommodated, for example, in a cabinet of 20 cms. x 20 cms. x 5 cms. Another particularly stringent requirement is that it is not possible to use energy sources on the train such as accumulators, dynamos driven by the wheels, traction energy and so on. Prior systems utilize one or more oscillators on the carriages which are fed by energy transmitted radiographically by the testing device along the track to the identification apparatus on the carriages and which send a signal by wireless transmission back to the testing device. This signal is modulated in a manner characterizing the carriages. More particularly, these known arrangements operate electronically and the oscillators are modulated with a multifrequency code. However, this requires a plurality of auxiliary generators for producing the various modulation frequencies, electronic switches and so on, the identification apparatus on each carriage comprising a comparatively large number of transistors and hence is expensive. Moreover, the energy consumption of these arrangements is comparatively high due to the large number of transistors, so that the quantity of energy received by radiation must also be very large.

The invention provides a particularly simple and relatively inexpensive solution to the problem.

The identification arrangement, in accordance with the invention, provides a small motor driven by energy transmitted from the testing device to the article to be identified. The motor brings about a reciprocating movement between a code carrier and a reading member whereby a sequence of pulses characterizing the article is produced. The sequence of pulses comprises at least one characteristic code group marking the beginning of the code series and a series of synchronizing pulses, synchronous with this reading process which mark the beginning of each code group. The code series modulates at least one oscillator for the wireless transmission of this information to the testing device.

Since the time available for the identification may be short, identification must be complete before the motor has reached its nominal number of revolutions, in other words, the testing device receives a pulse code series having a variable signalling speed. this pulse code series to be decoded in a correct manner, according to a further feature of the invention, the testing device comprises means for producing during each period between two synchronizing pulses a quantity characterizing the duration of this period, while the following period is divided into a number of subperiods proportional to the number of elements of each pulse code group for the formation of reading mark pulses for determining the polarity of the received signals.

The invention will now be described more fully, with reference to the accompanying drawing which shows an embodiment of an arrangement for identifying railway carriages.

FIG. 1 shows diagrammatically part of a testing device arranged at a fixed point along the railway track, and FIG. 2 shows an identification apparatus arranged on the carriages.

FIG. 3 illustrates an embodiment of a code disc, while FIGS. 4a-4d relates to a pulse-time diagram.

The testing device shown in FIG. 1 comprises an auxiliary interrogator transmitter ZE which is capable of transmitting energy having a frequency of, for example, 20 kc./s., through an aerial AE to a receiving aerial RE (FIG. 2) on a passing carriage tuned to this frequency by means of a capacitor KA. The aerial AB is, for example, a frame aerial of elongated shape, for example of 1 m. x 3 ms., while the aerial RE is, for example, a frame aerial of 15 cms. X 15 cms., so that also with a train passing at high speed, the aerial RE lies inside the field of radiation of the aerial AE for a sufficiently long time. As a matter of course, the generator ZE need only be switched into circuit when a train or a carriage passes.

The energy absorbed by the aerial RE of the arrangement shown in FIG. 2 is rectified by a rectifier GA so that a direct voltage V is produced across a smoothing capacitor KB, which voltage drives on the one hand the motor M, while it feeds on the other hand the transmitters ZC and ZN. The total quantity of energy absorbed is, for example, of the order of 250 mw., and is approximately completely consumed by the motor during its start. The nominal rotational speed of the motor is, for example, 25 revolutions per sec. and half this speed is attained, for example, in 40 milliseconds. When the motor has reached its nominal speed, the consumption is, for example, only 10 mw.

The motor M drives a code disc CS provided with a teeth characterizing the article and with holes AP, as shown in FIG. 3. The teeth and the holes move along reading heads KN and KC which consist of a winding on a permanently pre-magnetized magnetic circuit having an air gap. The teeth and the holes vary the magnetic resistance of the circuit so that the reading heads supply pulses, as shown in FIG. 4a and in FIG. 4b.

The voltage produced by the reading heads is proportional to the variation of the magnetic flux per unit time, hence proportional to the speed of variation of the magnetic flux. In order to ensure that the output pulses of the reading heads have a fairly rectangular shape, the teeth are shaped into the form of a saw-tooth having an oblique edge and a straight edge. The code disc CS as shown in FIG. 3 is designed for a code of eight code groups of five elements each, that is to say a starting code group SC of five mark elements (teeth) and seven identifi- In order to permitv a cation digits C1, C2 C7 constituted by a 2-out-of-5 code, that is to say that each code .group has two mark elements (teeth) and three space elements. For example, the first digit C1 consists of a space element, two mark elements and two space elements; the second digit C2 of two space elements, one mark element, one space element and one mark element, and so on. The holes AP are located at the beginning of each code group so that the synchronizing pulses supplied by the reading head KC mark the beginnings of the successive code groups.

FIG. 4a shows the series of pulses supplied by the reading head KN upon rotation of the code disc, and

FIG. 4b shows the synchronizing pulses of the head KC. By the exchange of the code disc, the code may be varied in a simple manner. A new code disc can be manu factured rapidly with the aid of a suitable punching vice. In practice, the number of digits required for the identification of a carriage will generally exceed 7 and be for example, from 12 to 15. These digits characterize, for example, the country of origin, the normal stand, the number of the carriage, and so on. In general, such a code is invariably associated with a given carriage and need consequently not be varied. However, it may be desirable in practice to have part of the code variable, for example, the part characterizing the place of destination of the priority in accordance with the load, for example, in case of deep-frozen goods. In such cases, it is preferable for the code disc to be fixedly arranged and for the reading heads to be caused to move along this disc under the control of the motor. The variable part of the code may then be adjusted by means of slides and the like.

The pulse series produced by the reading heads KC and KN are supplied to two transmitters ZC and ZN, respectively, which are designed in a corresponding manner. The pulses of the head KC are amplified by a transistor TR the emitter of which is grounded to the positive terminal of capacitor KB, while the collector is connected through a choke coil SM to the supply point -V. The base is connected through the winding of the reading head KC and a resistor RC decoupled by a capacitor KD to the supply point V. The transistor T2 is included in a generator arrangement having a tuned circuit consisting of an inductor LA, of a capacitor KF which determines the carrier frequency of the generator and is connected to the collector of the transistor TZ, and of a feedback winding LB connected to the base of the transistor TZ. The emitter of the transistor TZ is connected to ground, while the base is connected through the winding LB and a resistor RD decoupled by a capacitor KE to the supply point V. A tapping on the winding LA is connected to the collector of the transistor TR so that the strength of the oscillation produced by the generator is varied in accordance with the synchronizing signals supplied by the reading head KC. The windings LA and LB are arranged on the same ferrite rod FS which acts at the same time as a transmitter aerial and transmits the amplitude-modulated signals through a receiving aerial PC to a receiver SC of the testing device shown in FIG. 1. The carrier frequency of the transmitter ZC is, for example, 55 kc./s. and the carrier frequency of transmitter ZN which is designed in a corresponding manner is 105 kc./s. The transmitter ZN transmits the synchronizing signals from the reading head KN through the receiving aerial PN to the receiver SN of the testing device shown in FIG. 1. In the embodiment shown, the transmitters are amplitude-modulated. As a matter of course, the latter may also be frequency-modulated.

The identification signal pulses supplied by the receiver SN are applied, after being limited, to the input of a shift register SR which is passed to its zero position with each synchronizing pulse through a conductor BA and the delay device VR under the control of the synchronizing pulses supplied by the receiver SC. The shift register SR receives on the other hand shift pulses through a conductor BB at the instants corresponding to the centers of the elements of the identification code. Under the control of these shift pulses, the binary information in the shift register is moved through one place in known manner, while at the same time the binary information corresponding to the output voltage of the signal receiver SN is recorded in the shift register SR at that instant.

Consequently, the elements of the identification code are read at instants corresponding to the centres of these elements so that in case of a certain distortion of the pulses, the elements are nevertheless appreciated at their correct values. It is evident that the signalling speed dependings upon the rotation speed of the motor M, that is to say that the speed is still low during the start of the motor and the duration of a code element of a code group may be, for example, two or several times greater than the nominal rotational speed of the motor. Since, however, it must also be possible to identify carriages which move, for example, at a speed of kms. per hour, it is desirable not to wait till the motor has reached its nominal speed, but the inforamtion must be read as soon as possible. In order to permit of indicating the centres of the various code elements notwithstanding the variable signalling speed, the testing device is constructed in a particular manner, that is to say that these instants are derived from the duration of the preceding period between two synchronizing pulses. This is possible, since the signalling speed between two succeeding code groups varies only comparatively slightly, for example less than 10%. To this end, the testing device comprises a pulse generator GR, the pulse frequency 1' of which is high with respect to the pulse frequency of the code signals. On the one hand, the pulses of the generator GR are supplied to the counting circuit TC and on the other hand to the frequency divider FD which reduces the frequency by r a factor 10 to 0.1 i and which supplies these pulses to the inputs of two gates PA and PB controlled in opposite phases by the bistable trigger arrangement FA. The trigger arrangement PA receives through conductor BC synchronizing pulses from the receiver SC and its condition changes with each pulse, so that alter nately during one period between two synchronizing pulses the gate PA transmits the output pulses of the frequency divider FD to the counting circuit TA while the gate PB is cut off, whereas during the other period the gate PB transmits the pulses to the counting circuit TB while the gate PA is cut off. At the instant when the gate PA becomes conducting, the trigger arrangement FA supplies, through the conductor BD, a pulse which sets the counter TA in the zero position, whereas conversely, when the gate PB becomes conducting, the counting circuit TB is set in the zero position by a pulse of the trigger arrangement FA through the conductor BE. The counting circuits consequently each count alternately during a period between two synchronizing pulses and then remain in the occupied final position during the following period, which final posi= tron is consequently a measure of the duration of the preceding period. The coincidence circuits CA and CB respectively, are controlled by the trigger arrangement FA so that during the period in which the counter TA does not receive pulses, the coincidence circuit CA is operative and compares the occupied final position of the counter TA with the constantly varying position of the counter TC, while during the period in which the counter TB is inoperative, the coincidence circuit CB compares the final position of the counter TB with that of the counter TC.

The counter TC is set, through the conductor BF and the mixer stage MP, back to the rest position by each synchronizing pulse and consequently starts counting from zero. Let it be assumed that at such an instant the counter TA has occupied a position which characterizes the duration of the preceding period, which position is compared by the coincidence circuit CA with that of the counter TC. Since the frequency of the pulses supplied by the generator GR to the counter TC is ten times the frequency of the pulses supplied to the counter TA during the preceding period, the counter TC will reach a position which corresponds to the final position of the counter TA in a period of time equal to 0.1 of the duration of the preceding period between the synchronizing pulses. When the counters have reached .equal positions, the coincidence circuit CA supplies a pulse through the conductor BG to the trigger arrangement PB, while on the other hand the counter TC is passed back to the rest position by this pulse through the mixer stage MP and starts counting again until the final position of the counter TA is reached again, and so on. The coincidence circuit CA consequently supplies pulses during this period at instants which correspond to 0.1 period, 0.2 period, 0.3 period, and so on after the beginning of the period, that is to say at instants which correspond both to the center of the code elements and to the end of each code element, while in a corresponding manner, the coincidence circuit CB supplies pulses during the following period. Pulses are produced at the conductor BG, as shown in FIG. 40. The incoming signals must be read, however, and the shift pulses must be supplied to the shift register only at the instants which correspond to the centres of the elements, that is to say after 0.1 period, 0.3 period, 0.5 period, and so on. To this end, the trigger arrangement PE is switched through the conductor BF to a given rest state with each synchronizing pulse and subsequently, the state of the trigger arrangement FB changes with each pulse of the coincidence circuits CA and CB. Consequently, the trigger arrangement passes each time to the operating state after 0.1 period, 0.3 period, 0.5 period, and so on after a synchronizing pulse and supplies a shift pulse through the conductor BB to the shift register SR, as shown in FIG. 4d.

The shift register SR has five outputs which are connected on the one hand to the vertical conductors of a coincidence matrix memory MG and on the other hand to the coincidence circuit CC. The matrix memory MG is designed in known manner and consists of a plurality of memory cores M11, M12, M21 and so on, of magnetic material having a rectangular hysteresis loop, each of these cores being coupled with one vertical control conductor and one horizontal control conductor. The number of horizontal conductors is equal to the number of digit groups of the code. In the embodiment, four horizontal conductors are shown, but in practice, this number is from 12 to 15. The horizontal condutcors HG HGZ and so on are connected to various outputs of a counting circuit TD which may receive through the gate PD synchronizing pulses from the receiver SC and may be set to the following counting position by these pulses. In the rest position of the circuit arrangement, all the memory cores are in a given remanence state. A core can be passed to the opposite remanence state only when a current flows at the same time through the horizontal conductor and the vertical conductor coupled with this core. In the rest position of the arrangement, however, the gate PE is cut off so that, independently of the position of the shift register SR, no current can flow through the vertical conductors. A pulse is produced through a horizontal conductor only at instants when the counting circuit TD reaches the corresponding counting position. In the rest position, the gate PD is cut off and the counting circuit TD does not receive counting pulses so that currents will not fiow through the horizontal conductors of the matrix memory MG either.

As was already stated, the shift register SR is set back to the zero position by each synchronizing pulse. Under the control of the shift pulses the successive elements of the incoming code group are recorded in the shift register, so that at the end of the period, a whole code group is recorded. These elements are tested by the coincidence circuit CC. When the starting code group consisting of five mark elements has been received, the coincidence circuit CC responds and supplies a pulse through the conductor BH to the bistable trigger arrangement PC, as a result of which the latter is passed to the operating state. Under the control of the trigger arrangement PC, the gates PE and PD are releaesd. Moreover, a pulse of the coincidence circuit CC sets the counting circuit TD in the rest position through the conductor BK. The following synchronizing pulse sets the shift register SR to the zero position, while the counting circuit TD takes a step, but no pulse is then applied to one of the horizontal conductors of the matrix memory MG.

During the following period, first the digit code group is recorded in the shift register SR and with the subsequent synchronizing pulse the counting circuit TD takes a step while a pulse is applied to the first horizontal conductor HGl of the matrix memory so that the first digit is recorded on a line corresponding to the cores M11, M12, and so on. Moreover, the shift register SR is passed to the zero position by the synchronizing pulse. In order to ensure that the information is recorded in the matrix memory before it is erased in the shift register, the erasing pulse through the conductor BA is slightly delayed by the delaying device VR.

In a corresponding manner the other code digits are recorded in the matrix memory MG. Finally, the starting code combination consisting of five mark elements appears again in the shift register, whereupon the coincidence circuit CC again supplies a pulse and the trigger arrangement PC is set back to the rest condition, as a result of which the gates PE and PD are cut off, while at the same time the trigger arrangement FC supplies a pulse through conductor BX to indicate that the whole identification code has been received.

By known means (not shown), the information from the matrix memory MG is then read, as a result of which the cores of this memory are set back to the rest remanence state.

What is claimed is:

1. A signal identification system including an interrogator, a transmitter and a receiver, said transmitter generating a uniquely coded signal including a plurality of indicia arranged in consecutive order and comprising a pulse coded information carrier, said carrier having a plurality of characteristic information pulse code series thereon, each of said pulse code series but the first indicative of the numerical value of a respective one of said indicia, the first of said pulse code series constituting a synchronizing code for indicating the beginning of the information portion of said series, and a plurality of pulse code group marks for indicating the beginning of each of said information pulse code series, reading means coupled to said carrier means and responsive to said code representations, motor means activated by wireless energy transmission from said interrogator, said motor means imparting relative motion between said carrier means and said reading means, said reading means converting said series and said marks to electrical pulses at a rate dependent upon the rate of said relative motion, and means coupling the electrical pulses produced by said reading means to said receiver.

2. A signal identification system for transmitting information from a moving object to a spaced receiving location, said information identifying the said moving object and including a plurality of indicia arranged in consecutive order, said system comprising at said movable object a pulse coded information carrier having a plurality of characteristic information pulse code series thereon, each of said characteristic information pulse code series but the first indicative of the numerical value of a respective one of said indicia uniquely representative of said moving object, the first of said characteristic information pulse code series constituting a synchronizing pulse code for indicating the beginning of the information portion of said characteristic information pulse code series, and a plurality of pulse code group marks for indicating the beginning of each of said characteristic information pulse code series, reading means coupled to said carrier means and responsive to said code representations, motor means, said motor means imparting relative motion between said carrier means and said reading means, said reading means converting said characteristic information pulse code series and said pulse code group marks to electrical pulses at a rate dependent upon said rate of motion, means coupling said reading means to oscillating means, said reading means modulating said oscillating means in accordance with the information coded on said carrier and at a rate dependent upon the relative movement of said carrier and said reading means, means coupling the modulated signal from said oscillating means to said receiver, and wireless energy transmission means remote from said movable object for activating said motor means and said oscillating means.

3. The combination of claim 2 wherein said reading member includes a first sensing circuit responsive to said information pulse code series and a second sensing circuit responsive to said pulse code group marks, and said oscillating means includes a first oscillator connected to and modulated by said first circuit and a second oscillator connected to and modulated by said second circuit.

4. The combination of claim 2 wherein said code carrier consists of a disc of magnetic material having a plurality of information representative code teeth on the circumference thereof, each of said teeth being in the shape of a saw-tooth having one straight edge and one oblique edge movable with respect to an air gap 8 defined by said reading member in a pre-magnetized magnetic circuit.

5. A signal identification system including a transmitter and receiver, said transmitter generating a uniquely coded signal including a plurality of indicia arranged in consecutive order and comprising a pulse coded in formation carrier, said carrier having a plurality of characteristic information pulse code series thereon, each of said pulse code series indicative of the numerical value of a respective one of said indicia, a plurality of pulse code group marks for indicating the beginning of each said information pulse code series, the first of said pulse code series constituting a synchronizing pulse code for indicating the beginning of the information portion of said series, reading means coupled to said carrier means and responsive to said code representations, motor means, said motor means imparting relative motion between said carrier means and said reading means, said reading means converting said series and said marks to electrical pulses at a rate dependent upon the rate of said relative motion, means coupling said reading means to said receiver, said receiver including means for decoding said pulse code series, and means responsive to said synchronizing pulse code for synchronizing said means for decoding to the rate of said relative motion.

References Cited by the Examiner UNITED STATES PATENTS 1,767,749 6/1930 Fisher.

RODNEY D. BENNETT, Acting Primary Examiner.

CHESTER L. IUSTUS, Examiner.

P. M. HINDERSTEIN, Assistant Examiner.

Claims

1. A SIGNAL IDENTIFICATION SYSTEM INCLUDING AN INTERROGATOR, A TRANSMITTER AND A RECEIVER, SAID TRANSMITTER GENERATING A UNIQUELY CODED SIGNAL INCLUDING A PLURALITY OF INDICIA ARRANGED IN CONSECUTIVE ORDER AND COMPRISING A PULSE CODED INFORMATION CARRIER, SAID CARRIER HAVING A PLURALITY OF CHARACTERISTIC INFORMATION PULSE CODE SERIES THEREON, EACH OF SAID PULSE CODE SERIES BUT THE FIRST INDICATIVE OF THE NUMERICAL VALUE OF A RESPECTIVE ONE OF SAID INDICIA, THE FIRST OF SAID PULSE CODE SERIES CONSTITUTING A SYNCHRONIZING CODE FOR INDICATING THE BEGINNING OF THE INFORMATION PORTION OF SAID SERIES, AND A PLURALITY OF PULSE CODE GROUP MARKS FOR INDICATING THE BEGINNING OF EACH OF SAID INFORMATION PULSE CODE SERIES, READING MEANS COUPLED TO SAID CARRIER MEANS AND RESPONSIVE TO SAID CODE REPRESENTATIONS, MOTOR MEANS ACTIVATED BY WIRELESS ENERGY TRANSMISSION FROM SAID INTERROGATOR, SAID MOTOR MEANS IMPARTING RELATIVE MOTION BETWEEN SAID