Tire and reading device for a tire

Abstract

The present invention relates to a tire (2) with at least one high-frequency resonator (12) which is designed to oscillate at a plurality of definable resonance frequencies, wherein the definable resonance frequencies represent a, preferably multi-digit binary, coding.

Description

[0001] The present invention relates to a tire and a tire reading device.

[0002] The present invention relates to a method for marking tires with transponders (Radio-Frequency Identification, RFID).

[0003] To track vehicle tires from production to disposal, they are equipped with transponders that enable individual marking. Individual marking of each tire is key for applications in tire production, storage, and logistics.

[0004] The large number of tires that need to be individually marked requires a correspondingly large amount of data to uniquely identify each individual tire.

[0005] In electronic RFID transponders, the identifier is stored as a unique identification number in a read-only memory. To read this memory, the reader generates an electromagnetic field that supplies the transponder with electrical energy without contact, which is necessary to transmit the stored data to the reader. Frequencies from the so-called ISM bands (LF, HF, UHF, SHF) are available for the transmission of energy and information. While LF and HF transponders achieve a range of a few centimeters, UHF and SHF transponders reach several meters.

[0006] Equipping tires with electronic transponders (RFID chips) has two disadvantages: Firstly, despite their relatively small size, the electronic transponders cannot be embedded in elastomeric environments because the high Young's modulus of their housing creates a discontinuity that can lead to premature tire failure. Secondly, the alternative mounting of the electronic transponder on the inside of the tire is disadvantageous in the case of steel-belted tires because the conductive belt layers of the tire can shield the electronic transponder and thus impair communication with the external reader.

[0007] One object of the present invention is to improve the possibilities for marking tires. In particular, the marking should be read without contact. This should be as simple, cost-effective, space-saving, and / or robust as possible. At the very least, an alternative to the known options should be created.

[0008] The object is achieved according to the invention by a tire and a readout device having the features of the independent claims. Advantageous developments are described in the subclaims.

[0009] Thus, the present invention relates to a tire having at least one high-frequency resonator which is designed to oscillate at a plurality of definable resonance frequencies, wherein the definable resonance frequencies represent a, preferably multi-digit binary, coding.

[0010] In other words, the high-frequency resonator has at least two oscillatory regions or elements, each of which has a distinct resonant frequency. Thus, if the high-frequency resonator is excited, in particular with a linearly frequency-variable electromagnetic field, the respective resonance or a reflection factor determined from the respective resonance represents a coding, which can in particular be binary, i.e., a distinction can be made between "1" and "0."

[0011] This can therefore represent a possibility for coding tires, which can be detected by external stimulation.

[0012] According to one aspect of the invention, the resonator has a conductor structure, and the resonant frequencies of the resonator are defined by the geometry of the conductor structure. This may represent a concrete implementation possibility.

[0013] According to a further aspect of the invention, the resonator comprises a thin-walled dielectric on which a conductor structure is arranged. This may represent a concrete implementation possibility.

[0014] According to a further aspect of the invention, the resonant conductor structure is printed onto the thin-walled dielectric with highly conductive ink. This may represent a concrete implementation option.

[0015] According to a further aspect of the invention, the resonator is arranged between an outer belt ply and a tread of the tire. This may represent a concrete implementation possibility.

[0016] According to a further aspect of the invention, the outer belt layer is electrically conductive, and the conductor structure, together with the outer electrically conductive belt layer, forms a patch antenna. This may represent a concrete implementation possibility.

[0017] According to a further aspect of the invention, the outer belt layer comprises, preferably consists of, calendered metal cord. This may represent a concrete implementation possibility.

[0018] According to a further aspect of the invention, the thin-walled dielectric is formed by the rubber coating of the outer belt layer. This may represent a concrete implementation possibility.

[0019] The present invention also relates to a reading device, preferably a measuring and evaluation electronics, for a tire as described above, which is designed: • to excite the high-frequency resonator of the tire with all valid resonance frequencies of a defined code space, • to determine the respective value of the reflection factor from the ratio between the injected power and the reflected power of each resonance frequency of the defined code space and • to determine the coding of the tire, preferably a multi-digit binary one, from the specific reflection factors of each resonance frequency of the defined code space.

[0020] This makes it possible to provide a reading device to read a tire as described above.

[0021] According to one aspect of the invention, the readout device comprises a microwave transmitter configured to excite the tire's high-frequency resonator with all valid resonance frequencies of a defined code space. This may represent a concrete implementation option.

[0022] According to a further aspect of the invention, the microwave transmitter is configured to feed a broadband antenna of the readout device with an RF signal to excite the tire's high-frequency resonator with all valid resonance frequencies of a defined code space. This may represent a concrete implementation possibility.

[0023] According to a further aspect of the invention, the readout device comprises a pair of directional couplers, each with an effective value rectifier, which are configured to detect the input power and the reflected power of each resonant frequency of the defined code space. This may represent a concrete implementation possibility.

[0024] According to a further aspect of the invention, the readout device comprises a control unit configured to determine the respective reflection factor from the ratio of the respective detected input power and the detected reflected power. This may represent a concrete implementation possibility.

[0025] According to a further aspect of the invention, the control unit is further configured to determine the tire coding from the determined reflection factors of each resonant frequency of the defined code space. This may represent a concrete implementation option.

[0026] According to a further aspect of the invention, the coding is multi-digit binary, and a predetermined threshold value of the determined reflection factor leads to a distinction between zero and one. This can represent a concrete implementation possibility.

[0027] An embodiment and further advantages of the invention are explained below in conjunction with the following figures. Fig. 1 a perspective schematic representation of a section of a tire according to the invention; Fig. 2 a schematic cross-section through a section of the tire when stimulated to read a code; and Fig. 3 a schematic block diagram of a readout device according to the invention.

[0028] The solution to the inventive problem is based on an identification carrier having several cavity resonators with multiple resonance frequencies, which can be individually adjusted to store a data volume of, for example, 12 bits. To read the stored data, the resonator is excited with a linearly frequency-variable electromagnetic field, and the reflection coefficient is measured to determine the position of the adjusted resonances.

[0029] Thus, the inventive problem is solved with the aid of at least one high-frequency resonator 12 capable of oscillating at several definable frequencies. The resonator 12 consists of a thin dielectric 14 onto which a resonant conductor structure 16 is printed with highly conductive ink.

[0030] Fig. 1 shows the typical structure of a tire: The tread 4 is located on the outer circumference of the tire 2. From outside to inside follow the wound bandages 6, the steel cord belt layers 8a, 8b, and the textile cord inserts 10.

[0031] The Fig. Figure 2 shows the resonator 12 and its arrangement in the tire 2. During the assembly of the tire 2, the resonator 12 is arranged between the outer belt ply 8a and the tread 4, so that the conductor structure 16, together with the outer (conductive) belt ply 8a, forms a patch antenna whose specific resonance frequencies are defined (encoded) by the geometry of the conductor structure 16. The belt plies 8a, 8b consist of calendered metal cord, so that their rubber coating can be used as the dielectric 14. In this case, the resonator 12 can be printed with conductive ink directly onto the outer belt ply 8a, e.g., using an inkjet printer.

[0032] The Fig.Figure 3 shows the structure of the measurement and evaluation electronics. The intelligent control unit 30 (e.g., a microcontroller) calibrates the internal components, controls the measurement of the scattering parameters of the resonator 12, and transmits the results to an external device (not shown). To read the coded information, the control unit tunes the microwave transmitter 18 successively to all valid resonant frequencies of the code space and feeds the broadband antenna 20 with the adjusted RF signal. With the help of the directional couplers 22a, 22b and RMS rectifiers 24a, 24b, the control unit 30 determines the respective value of the reflection coefficient from the ratio between the input power 26a and the reflected power 26b. In the event of resonance, the reflection coefficient decreases.If the measured reflection factor is below a specified limit, the controller 30 assigns the value "TRUE" to the set frequency; otherwise, the value "FALSE." From the truth values ​​of all valid frequencies in the code space, the controller 30 determines the information encoded in the resonator 12 and outputs it to the external device. List of reference symbols (part of the description) 2 tires 4 treads 6 coil bandage 8a, 8b steel cord belt layers 10 textile cord inserts 12 high-frequency resonators 14 Dielectric 16 resonant conductor structure 18 microwave transmitters 20 Broadband antenna 22a, 22b Directional coupler 24a, 24b RMS rectifiers 26a fed-in power 26b reflected power 30 Control unit

Claims

[1] Tires (2) with at least one high-frequency resonator (12) which is designed to oscillate at several definable resonance frequencies, wherein the definable resonance frequencies represent a, preferably multi-digit binary, coding. [2] Tire (2) according to claim 1, wherein the resonator (12) has a conductor structure (16) and wherein the resonance frequencies of the resonator (12) are defined by the geometry of the conductor structure (16). [3] Tire (2) according to claim 2, wherein the resonator (12) comprises a thin-walled dielectric (14) on which a conductor structure (16) is arranged. [4] Tire (2) according to claim 3, wherein the resonant conductor structure (16) is printed on the thin-walled dielectric (14) with highly conductive ink. [5] Tire (2) according to one of the preceding claims, wherein the resonator (12) is arranged between an outer belt ply (8a) and a tread (4) of the tire (2). [6] Tire (2) according to one of claims 2 to 4 and according to claim 5, wherein the outer belt layer (8a) is electrically conductive and wherein the conductor structure (16) together with the outer electrically conductive belt layer (8a) forms a patch antenna. [7] Tire (2) according to claim 5 or 6, wherein the outer belt layer (8a) comprises, preferably consists of, calendered metal cord. [8] Tire (2) according to claim 3 or 4 and according to claim 7, wherein the thin-walled dielectric (14) is formed by the rubber coating of the outer belt layer (8a). [9] Reading device, preferably measuring and evaluation electronics, for a tire (2) according to one of the preceding claims, which is designed: • to excite the high-frequency resonator (12) of the tire (2) with all valid resonance frequencies of a defined code space, • to determine the respective value of the reflection factor from the ratio between the injected power (26a) and the reflected power (26b) of each resonance frequency of the defined code space and • to determine the, preferably multi-digit binary, coding of the tire (2) from the determined reflection factors of each resonance frequency of the defined code space. [10] Reading device according to claim 9 with a microwave transmitter (18) which is designed to excite the high-frequency resonator (12) of the tire (2) with all valid resonance frequencies of a defined code space. [11] Readout device according to claim 10, wherein the microwave transmitter (18) is designed to feed a broadband antenna (20) of the readout device with an RF signal in order to excite the high-frequency resonator (12) of the tire (2) with all valid resonance frequencies of a defined code space. [12] Readout device according to one of claims 9 to 11, comprising a pair of directional couplers (22a, 22b), each having an effective value rectifier (24a, 24b), which are designed to detect the injected power (26a) and the reflected power (26b) of each resonant frequency of the defined code space. [13] Readout device according to one of claims 9 to 11 and according to claim 12 with a control unit (30) which is designed to determine the respective reflection factor from the ratio of the respective detected fed-in powers (26a) and detected reflected powers (26b). [14] Reading device according to claim 13, wherein the control unit (30) is further configured to determine the coding of the tire (2) from the determined reflection factors of each resonance frequency of the defined code space. [15] Reading device according to one of claims 9 to 14, where the coding is multi-digit binary and where a predetermined limit value of the determined reflection factor leads to a distinction between zero and one.

Images