DE1774493C3 - Arrangement for the identification of objects equipped with an identification plate - Google Patents

Description

lies, the frequency shift of the reflected signal also makes itself due to the doubling effect noticeably disturbing. In any case, the receiver must be designed to be broadband, but what is achievable Signal-to-noise ratio worsened with respect to extraneous noises.

This deficiency avoids the arrangement of the genre given in the introduction, that from the USA.-file citation 3 247 514 is known. Due to the use of electromagnetic waves, the Object speed is practically no longer an issue. The Doppler frequency shift is for the same reason negligibly small. The known arrangement by a formation of the Kennuugsplatte, which leads to a rotation of the polarization direction of the reflected wave with respect to the incoming wave and by using a A receiving antenna that is sensitive only for this rotated polarization direction is achieved. This is a disadvantage however, that a special training of the transmitting and receiving antenna is necessary. Such »: Special antennas are taken from the French patent specification 1 457 230 and from the USA patent specification 3 247 known to HIM.

The invention is based on the object of providing an arrangement of the generic type specified in the introduction train that the objects to be identified with ρ actically any speed on the scanning silence passed and identified with great certainty using simple antennas can be.

According to the invention, this object is achieved by that the receiver uses the reflected, phase-modulated wave directly from the transmitter received reference wave demodulated.

Although also occurs with the from the USA. Patent specification 3 247 514 known arrangement inevitably a phase modulation of the reflected wave. This However, phase modulation is not used for identification. Rather, it makes itself felt in the recipient - unlike according to the invention - not noticeable at all, since the recipient has no reference phase is fed. The code recognition is based exclusively on the fact that the polarization direction of the reflected wave successively once in one device, the other time in the opposite Direction is rotated relative to a reference direction. With the previously known arrangement is therefore taken a different path than with the invention.

An advantageous embodiment of the arrangement according to the invention is that the identification plate consists of a flat box, which is uniform with parallel surfaces with a low dielectric constant is filled, which are metallized on the side, and that the box is closed by a metal lid which has openings corresponding to the identification code

Another advantageous embodiment of the an-order, which, in addition to the identification, allows the acquisition of further data of the objects, stands out characterized in that the identification plate comprises three groups of openings, of which the middle one The group is used for the actual identification, while the other two groups are used to determine the The beginning and end of the code, the direction of movement and the speed of the object are used.

According to a further advantageous embodiment, the distance between the transmitting antenna and the identification plate of the object at the moment of passing is taken into account in that the Source of supply fed directly to a channel of the receiver after passing through a phase shifter and has the same direction of polarization as the reflected wave.

Multiple scanning of one and the same object at the moment of its passage can be achieved according to a further advantageous embodiment in that a number of k connected scanning channels carry out the simultaneous scanning of k adjacent digits and logic circuits decode the voltages received at the outputs of A: receivers.

According to a further advantageous embodiment, the identification reliability is reduced as a result of loop movements of the object Avoided while passing the scanning station that the transmitter is the incoming Shaft perpendicular to the edges of the openings of the identification plate and in the direction of movement of the to identifying object polarizes, radiates and the motion wave parallel to these edges and polarized perpendicular to the direction of movement, radiates onto the knitting plate.

Another advantageous embodiment of the arrangement according to the invention is that the incoming and reflected wave an electromagnetic bundling device located in front of the identification plate passes through.

Another advantageous embodiment is characterized in that the identification plate has a group of 2 /; Halbdigils for the automatic adjustment of the sampling level, where ρ is greater than or equal to η .

Larger tolerances in the formation of the identification plan ic finally allow an advantageous further development of the arrangement, which means that the sample and reference waves consist of an RF carrier, the lower one with a subcarrier Frequencies is modulated, and that when receiving only those from the openings of the identification plate generated phase modulation of the subcarrier is evaluated.

The invention will now be considered in the context of the description which follows, by way of example explained with the drawings.

It shows

F i g. 1 a first example of an identification plate according to the invention,

F i g. 2 an identification device according to the invention that works with standing waves,

FIG. 3 shows the voltage (or field) fluctuation within the range shown in FIG. 2 shown Identification device,

4 shows a phase shifter for modulating the voltage or the output polarity,

F i g. 5 a layout diagram of an identification plate,

F i g. 6 the scheme of a preferred structure of an identification plate according to the invention,

F i g. 7 a variant of the UHF circuit of the station,

8a and 8b show two possible voltage combinations at the output of the in F i g. 7 circuit shown for re-scanning the code,

F i g. 9 regulates a special arrangement of the scanning and corresponding to the distance that between

Reference conductor opposite the identification plate, scanning device and identification plate 1 is located. The one from the

10a and 10b, respectively, top view and front distance-dependent reference phase therefore remains

view of an identification device, independent of the modulation of the opening 2 not influenced. the

probing of the distance between identification plate 5, however, this device's performance is impaired.

and reading device, restricts that the regulation is only

11 shows a coding example with simultaneous stantc removal valid and accordingly

Illumination of 5 bits, regardless of any fluctuations in this distance.

Fig. 12 shows an identification device corresponding to that in.

10a and 10b shown, with use io In this device, the modulation of the output

a carrier modulated during transmission. Sensing wave through the openings 2 a switchover

In the arrangement according to the invention for identifying the channel on reception, which in turn is a module

fication consists of the ob- 1 ation to be identified of the output voltage or the output

Project coupled element from a plate, which has the polarity of the receiver 4 result. The on

Bears identification code and modulated in the now following 15 output S of the receiver 4 available

Description definition designated as identification plate voltage is now, for example, via a

net is. Standard line after a previous run through

Such an identification plate 1 is shown in FIG. 1 shows a storage and transmission device to a represents. With the Kennungskodc shown on it transferred to the center. Since all local it is a digital code, which must be of the same type due to the 20 scanning positions openings 2 is expressed, the depth of which is equal to the central unit to be able to these from each other an odd multiple of one for sampling. In this context it is possibly used Quarter wavelength corresponds to borrowed, each local sampling point with its own

In Fig. 2 is a schematic plan view (to equip a Hori line or a special carrier

zontal level) of the identification plate 1 is shown. These 25 or beyond have their own identification signal

In this case, the plate works with a scanning device. On the other hand, it would be possible to

that uses the effect of the standing walls. data from the sending station together with a

The code is scanned with the help of a special code within the entire Abtaslinfor-

a UHF channel 3 equipped device to transmit a mation.

Transmitter 6, a decoupling element 51, a receiver 30 In FIG. 5, a distribution scheme of a catcher 4 and a probe 7 is shown. This identification plate 1 of normal polarization on the long side of the openings comprises three groups of openings 2. The gene arrives from the transmitter 6 via the UHF channel 3 to a group C corresponds to the start of scanning and the identification plate 1. The HUF wave is corresponding In addition, it is possible to transfer the code of the respective position of the identification plate 1 35 identification information of the local scanning location and the scanning device either to the underground and to determine and nungsplatle the speed data of the vehicle identifying to 21 or the underground 22 of the openings 2 of the identification plate 1 reflects, which in turn translates to a. A second group A of openings 2 leads to a change in the path length of the UHF channel, which at the other end of the identification plate 1 corresponds to the value of half a wavelength. 40 corresponds to the bits of the end of the code. This results in a pulse modulation .τ of the middle group B of the openings 2 represents the Ken phase of the reflected wave. As shown in FIG. 3, the vehicle's display code. To avoid this, the voltage V (or the field) at which this code is dependent on the direction of movement of the probe 7 either has a maximum value or the vehicle must not symme-Wcrt zero, depending on whether the UHF wave is built up on the 45 tric. It is sufficient here if the background 21 or the background 22 of the opening codes A and C for the beginning and the end is reflected in the gene. The difference at the probe 7 of the receiver form is that the decoding and gers 4 pulses present accordingly have the direction of transmission of the identification code B, whichever will give the logical value 1 or the logical value. These codings A and C can have a value of 0. · 50 which have evenly alternating bits. A similar result is obtained when using the decoding of the vehicle speed as shown in FIG. 4 illustrated scanning device. At speed is relieved. The distinction is made with this device, the scanning wave coming from the transmitter 6 then has a normal polarization on the longitudinal of periods or openings 2 according to its different number of scanning waves 1. In the example chosen, this local sampling station will begin a code C for the sampling via a directional coupler 91 on the channel 31, and the corresponding characteristic data of the local will be transmitted. After a first pass through the scanning station, the speed information via a circulator 52, the scanning wave on which the vehicle, an identification code ß of this opening 2 of the identification plate 1 is reflected, through 60 vehicle and a code A for the end of the circulator runs again 52 to now with scanning.

With the help of a second directional coupler 92 on a F i g. 6 shows one in front for the sake of simplicity Input channels of the receiver 4 transmit to the type of identification plate according to the invention. will. A second wave, which is used as a phase reference This consists of a flat box 101. the Wave serves, becomes uniform with parallel dielectric fans 23 at the same time as the first wave 65 sent out and filled via a channel 32 directly to the size of a bit that is a small one Receiver 4 transmitted. In this channel 32 there is a dielectric constant. This parallelepiped Phase shifter 8, which ncr the phase of the reference waves are either metallized on the side or are of-

7 8

separated from each other by a metal liner. Receiver 42 accordingly receives no energy over the entire arrangement is through a corresponding channel £ 31. _{By combining the voltages S 1} , S ₁ , S ₃ and S- punched out from the aforementioned codes, the receiver 41 and metal cover 100 are completed. It also turns out to be a repeated scanning of the code, which is advantageous, the surface of the arrangement 5. The combinations shown in FIGS. 8a and 8b by a dielectric coating against wear and tear use exclusively logical "OR" and dust deposition or contamination any kind of circuitry. In the example of FIG. 8 a will protect the first. Besides using a Community logical sum of the signals S ₁ and S ₃ determines seed identification plate 1 with the three Kodierun- a value from which it follows that the by gene A, E, C, it is possible these three partial plates to Area D22 corresponds to digit D formed. To split them up, which results in the advantage that the logical sum of the signals S _t and S ₄ leads to equal plates for the codes A or C as standard in a timely manner to a second value that can be produced by the and thus only the plate for the background D 21 of an opening formed digit D B coding then corresponds to being punched out. Now you need the logical sum. 15 of the two values determined in this way are obtained

As far as the choice of the UHF wave for scanning a logic value, which characterizes the digit D , is concerned, the wavelength to be used depends on the expected performance with the combination shown in FIG. 8b. If one also selects a logical value that indicates the digit E is too small a wavelength, the result is that the value is too high. In this case, the initial requirements for oil accuracy, the cleanliness of the ao voltage follows the plates 1 moving past in front of the channel £ 31, with the influence of moisture or snow openings, regardless of the openings, case as well as interfering reflections prevent strong attenuation before the Walk past Canal D 31. On these causes would. On the other hand, the choice of a way would be carried out a double scan, too long wavelengths too large dimensions- 'Other combinations are also possible, resulting in the device. »5 in addition, a circuit can be formed that

If, for example, wavelengths are used while scanning more than two adjacent

10 cm, this would allow a scanning distance from north digits. In this way, the

sometimes 15 to 30 cm, which, however, increases the UHF security of the identification. The one-on-one

Would require bundling. If the scan results are different, they are saved

operating conditions and in particular at 30 and then before forwarding to the center

fairly low speeds compared to the identical.

decorative vehicle is the interposition of a For the circuits described so far as well

Bundling device is not required. for the devices with approximate sampling If you use wavelengths of the same size, you can use several solutions to put the scanning device in one position

arrangement of 10 to 25 cm, so the distance 35 to the identification plate 1 can bring. So can

A guide rail, for example, can be used between the identification plate 1 and the scanning device

be lighter, d. H. between 2 and 3 cm, the one on which the scanning device is moved

which, however, can be achieved by mechanical tracking without causing contact between

this distance requires. A variant of the UHF see the identification plate and channel 311 is coming.

Circuit of the in F i g. 3 is shown in 40. It is also possible to use the channel 31 or the key F i g. 7 shown. Extension plate 1 to enlarge downwards.

In this circuit, two adjacent In F i g. 9 is a further improvement of the switching digits D and E scanned at the same time, as a result of which it is shown with approximate scanning, with it being possible to repeat the scanning of the code on the identification aid of which the scanning is independent of any disk 1. For the 45 fluctuations in the distance of the identification plate 1, the shapes of the openings shown at a, b, c and d can follow. In this case, two channels 31 and 32 are used for 2, the output voltages appear stacked one above the other and work with crossed on the outputs S ₁ , S ₂ , S ₃ and S ₄ as a result of the polarization. The channel 31 is traversed by a phase shift combination in the Rieh horizontally polarized wave, which is transmitted by device couplers 93, 921 and 922. In illustration b 50 the phase modulations through the openings 2, for example, the background D 21 of the opening identification plate 1 is influenced. The cross-section with respect to the channel D 31, while an area of this conductor must in this case not be greater than £ 22. The channel 32 ran finds the sampling wave emanating from the transmitter 6 the phase reference. This conductor passes through the circulator 52 and reaches the di- 55 running wave is vertically polarized and strikes somil gits D and E of the identification plate, since it has a directional coupler 93 to the two channels D 31 and this wave to separate the openings in the identification plate is now being transferred to the front of the £ 31. A part of this wave is reflected from the metal cover 100, and specifically accordingly, independently from the surface £ 22, and runs from the openings. The width of the channel 32 came into the channel D31, where it reunites with the wave reflected by the 60 accordingly greater than the length of the openings its background D 21, which leads to the channels 31 and 32 can have a rectangular Γοπτ the phase shift between these two and is attributable to parts as shown in Fig. 9. The scanning shaft can be arranged through a "T". Furthermore, the circulator 52 can then run and arrive at square channels of the "Ridge" type via the directional coupler 921 to one of the two 65. These are advantageously filled with a dielectric channels of the receiver 41. At the same time, the large constant transmits filled.

Transmitter to the same directional coupler 921 via the FIGS. 10a and 10b each show a top view Directional couplers 911 and 912 have a reference swcllc. He sees and a front view of an identification

9 10

device using the shown in Fig. 9 shown in Figs. 10a and 10b. This

Improvement and for a somewhat more remote arrangement works with a scanning shaft that from

Sampling at a distance of about 15 to a high frequency carrier formed by

30 cm. The sample and reference channels 31 and 32, respectively, are modulated to a lower frequency subcarrier

are arranged one above the other, with 5 being. The through the openings of the identification plate

With the help of a deflection 10 of the reference channel 32 vertically on the subcarrier caused phase modules

can emit cal polarized. A bundling device is used for scanning. With the help of

11 lies between the scanning conductors and the high-frequency carrier, thus resulting in a broadcast

Identification plate, the bundling essentially having a directional effect, which makes it possible to

lichen takes place in the horizontal plane. For this purpose, io number η of selected digits can be precisely illuminated. There

for example a UHF lens or a single one on the other hand, the depth of the openings is equal to one

Parabolic reflector or two interferometric lenses quarter wavelength of the subcarrier, can

or reflectors can be used. Dimensions kept large and the tolerances

The devices described so far have been continued.

in each case only the illumination of a single diagram of the code on the identification plate. It uses a modulator 12 and a however, several digits can also be heard simultaneously on the oscillator 13 during the transmission and on be illuminated by adding the * code to a demodulator 141 and Digit changes. In order to avoid that the code 142, which is in each case before the directional coupler 92 and does not change during an identification process, 20 is arranged on the receiver 4. A tax oscillator the number of illuminated digits must be constant 15 controls the frequency of the carrier wave. The modules stay. For this purpose, for example, this carrier can be automated to the frequency of the sub-table Adjust the reception level so that it can be carried out in the UHF range, i.e. according to a certain number of η illuminated neither after or before the transmitter 6, which here as Digits exceeds the reception threshold. To do this, 25 amplifier works.

an additional code is used, which at Since the carrier frequency is generally higher here

each end of the identification plate 1 is located. This code is the same as for the circuits described so far,

is formed for example from 2p half digits, which became the width of the dielectric parallelepipeds

Express values alternately + 1 and - 1, where ρ 23 in the flat box 101 of the identification plate 1

is greater than or equal to η . The pulses 1 and 0 are kept smaller, with a view to the

be off with each other as long as the dividing lines of the reference shaft. In contrast, it is

Transmission lobe of the scanning device not at the same time η but not required, at the same time also the width

gits of the identification plate 1 contains. To be reduced by counting the code digits, since one digit is without

These pulses can determine the number of digits further the width of several parallel surfaces

that can be had from the club at one over the 35 reception.

threshold lying level can be detected. Thus, on the basis of this count, arrangements for identification have now been made possible to set the level of the moving objects and especially vehicles so that only π letters in the club, which are contained with a simple, robust, comgit. This regulation takes into account any fluctuations in the scanner plate automatically and without high costs associated with identification, in addition, a distance has been added. It is also possible to carry out such an auto-scanning device for coded data or for identifying level control along the identification plate 1 tion of the movable object or vehicle by adding a cine to this plate 1. In all cases, this scanning takes place without assigning an additional track, the frequency of which is above that of the material contact between the scanning device and Ken-Kennungs-Digiis. 45 opening plate. By using the ^above in FIGS.

11 shows, by way of example, a code with circuits shown up to 12 which can scan

simultaneous illumination of 5 digits or independently of any rolling, rolling odei

10 half digits. With this solution, the digits become yaw movements of the objects to be identified

»0« formed by two half digits »+ ■ 1« and »—1«. These devices also work independently

and do not provide a signal. A digit "- 1" comes from 50 from the direction and speed of movement;

that of these objects or vehicles reflected by the surface 22 of the opening 2. Furthermore, pre

Signal, a digit »+ 1« of which you can see through the underside, a non-location-bound scan

reason 21 of this opening reflected signal. The space to identify a fixed object

The resulting sample is binary, as one has to use tes when receiving or finally a sample plate

deliberately operating the digits “- 1” and the digits “0” together with a radio, which is

exchanges. Radio beam over the detection of the identification plate

The arrangement according to FIG. 12 represents a variant.

For this purpose 2 sheets of drawings

Claims (9)

1 2 wave consists of an RF carrier, which is modulated with claims: a lower frequency subcarrier, and that when receiving only that of 1. Arrangement for the identification of objects, the openings (2) of the identification plate (1) erdie phase modulation of the subcarrier from identification plate produced by a 5 carrying a coded information are equipped, which this is rated. Information in the form of recesses or Contains gradients and from a stationary one Transmitter on incoming electromagnetic waves also reflected a stationary receiver, io the wavelength in centimeters or deci- The invention relates to an arrangement for identifying meter range and the depth of the recess of objects that are coded with a gen or recesses equal to the ^ ^inform used; °° bearing Γ'π ^^ ^ ^ö & Τηί e _{4 smc} ^ _we icjj _e t _he se information in the form of AusWellenlänge and the reflected wave in phase recesses 15, or contains pits and of a is modulated, characterized in that the stationary transmitter coming electromagnetic that the receiver (4) reflects the reflected, phase waves on a likewise stationary receiver modulated wave with the help of a wave directly from the transmitter, the wavelength in the centimeter of the (6) received reference wave demodulated. or decimeter range and the depth of the 2. Arrangement according to claim 1, characterized ge ao,,,. . _r,. , <? ,
indicates that the identification plate (1) from "ehmungen or Vert.efungen equal to _{4 of} the used consists of a flat box (101) which is equal to the wavelength and the reflected wave is moderately modulated with parallel surfaces (23) of low dielectric phase. tricity constant is filled, the laterally metallic. The objects to be identified can be are siert, and that the box (101) by a 35 in particular to vehicles of the most varied Metal lid (100) is completed, which act the genera. There are already numerous Has identification code corresponding openings. Known orders, which according to different Pnn- 3. Arrangement according to claim 1, thereby oecipien work. The identification is usually based on the fact that the identification plate (II) includes three groups (Λ, B ₁ C) of openings (2), 30 fixed-foil successions of reflective surfaces of which the middle group (B) are assigned, the entirety of the reflective identification, while the two generating surfaces form the identification plate and dit: other groups (A, C) for the determination of the code identification enabling! represents. In doing so, however, those used by the speed of the object are mixed up. 35 useful echoes emanating from the reflective surfaces 4. Arrangement according to claim 1, characterized gc- with interference echoes emanating from the object itself, indicates that the reference wcllc makes identification more difficult or even more difficult run a phase shifter (8) directly one is faulty. To avoid this disadvantage is Channel of the receiver (4) is supplied and known, the objects themselves with an encoded same polarization direction as the reflected 40 Signa! to provide emitting transmitter. Although Wave owns. this offers no technical difficulties, 5. Arrangement according to claim 1 or 4, but there are particularly in the case of a large number characterized in that a number of A; of objects in this solution, the costs are considerable Scanning channels (/) 31, E31) the Heller Höhe. simultaneous scanning of k neighboring di- 45 The arrangement working according to the echo movement Gits (D, E) and logic circuits have the advantage that the those at the outputs of k receivers (41, objects only with a simple, robust and 42) decode the voltages received. relatively small identification plate 6. Arrangement according to claim 1, characterized thereby. For example, on the German display, that the transmitter (6) the outgoing 50 font 1 232 070 an arrangement for scanning of Shaft perpendicular to the edges of the openings (2) attached to movable objects the identification plate (1) and known in the direction of movement, with a stationary ultrasonic source polarized of the object to be identified, and a stationary ultrasonic emitter works radiates and the reference wave is parallel to this and where the moving object has a license plate edge and perpendicular to the direction of movement 55 carries plate with raised and recessed areas that polarized, radiates onto the identification plate. correspond to the coded identifier, where the 7. Arrangement according to claim 1 or 6, da- receiver for the presence or absence of a characterized in that the outgoing and interference or a reflection of the ultrasound-reflected Wave responds to waves in front of the identification plate. A major shortcoming of this lying electromagnetic bundling device 60 previously known arrangement, however, lies in the Vertung (11) passes through. Twist of an acoustic signal. Due to the 8. Arrangement according to claim 1, 3 and 7, the relatively low propagation speed of characterized in that the Kcnnungspla'tc (1) sound waves is namely a perfect resolution at each of their ends a group of 2 p half of the reflected signal only at has relatively digits for automatically setting the scanning 65 low speeds of the level to be identified, where ρ is greater than or equal to η . moving objects possible. Even: if the 9. Arrangement according to claim 1, characterized in the speed of the object within the upward indicates that the scanning and reference areas are limited by the required resolution