DE10253367A1 - Energy-autonomous tire measurement device for measuring the operating parameters of a tire, especially for automotive use, comprises one or more piezoelectric fibers acting as both sensor elements and electrical energy supply - Google Patents

Abstract

Tire measurement device consist of a piezoelectric fiber that acts as a sensor element for measuring tire operating variables. The inventive device also has a transmitter for transmission of sensor signals, with the energy for the transmitter derived from the electrical energy generated by the fiber. Optimally a network of fibers is formed into a grating or mesh that is incorporated in the steel reinforcing belt.

Description

The invention notification relates to methods and Devices for basic components of energy self-sufficient radio interrogable tire sensors and exemplary solutions for self-sufficient radio users Tire sensors which are based on the components according to the invention.

Parameters of the tire of a motor vehicle such as tire pressure, temperature, but also the frictional connection between the tire and the road are decisive variables for the safety and driving dynamics control in motor vehicles. Due to the high relevance of this topic, numerous solutions for tire sensors have been developed in the past and the relationships between tire pressure, tire temperature, tension, elongation and friction coefficient, frictional engagement, road surface texture, rolling resistance, aquaplaning etc. have been intensively discussed. Basic information can be found, for example, in DE 3937966 A1 . DE 4242726 A1 and WF Kern: "On deformation measurement on vehicle tires using a special strain gauge", Automobiltechnische Zeitschrift ATZ, 63 (1961) p. 33 ff.

Sensors generally have one electrical cable connection through which the sensor with the energy supplied and about which the measured values of the sensor are passed on electrically. For tire sensors is such a solution generally unsuitable because the rotating movement of slip rings or the like Devices for a wired transmission would require. As a result, the sensor sizes of Tire sensors are generally radio controlled from the location of the measurement to one remote evaluation unit.

Many previously known radio sensors However, they have one major disadvantage: you need one Battery or the like Sources of energy that involve considerable costs through purchase and, in particular, maintenance or cause danger (leakage of battery acid, imbalance, etc.). The use or lifespan of batteries is also often due to the environmental conditions (e.g. very high or low temperatures) limited.

Characteristic of a bike is that there are parts on it that rotate while driving and that these rotary movements:

• - to the one in the bearings and / or at the wheel / lane contact points cause both vibration and sound and / or ultrasound signals
• - to the others the rotational movement to mechanical forces and deformations e.g. of the tire.

So these two forms of mechanical energy at least as soon as the vehicle moves, at the location or in the vicinity of the location, on which the tire sensor is to work.

With a sound transducer or piezo transducer this acoustic or mechanical energy into an electrical alternating signal be changed. According to the invention Energy used to operate one or more sensors their state or changes in state transmit by radio.

From the prior art are still self-sufficient Known radio sensors, where mechanical energy available locally is used to operate a radio sensor. Use too of piezoelectric elements for this purpose is in principle known.

Wireless, passive quartz sensors for tire measurement are in R. Grossmann: “Wireless Measurement of Tire Pressure with Passive Quartz Sensors ", Proceedings of the SPIE, SPIE Vol. 3670, pages 214-222, Newport Beach, 1999.

From a completely different department piezoelectric fibers are known. Basic descriptions for such fibers can be found in B.Z. Janos, N.W. Hagood: "Overview of active fiber composites technologies ", Proceedings of the 6th International Conference on new Actuators, ACTUATOR98, June 98, Bremen, Germany or in K. Pannkoke, T. Gesang, M. Clüver, D. Sporn and A. Schörnecker: “Structural conformity integrable function modules based on PZT fibers ", ADAPTRONIC CONGRESS 1999, March 3-4 in Potsdam, pp. 138-143.

The invention is based on this based on the task of being a very inexpensive, sturdy and lightweight in large numbers to develop energy-self-sufficient tire measurement.

This task is accomplished through the inventions of independent Expectations solved. Advantageous refinements are specified in the subclaims.

The tire measuring device accordingly one or more piezoelectric fibers.

There are two main types how the piezoelectric fiber of the tire measuring device is used can be. For one thing, the piezoelectric fiber serves as one or the sensor element of the measuring device. It measures by converting from mechanical in electrical energy mechanical tire sizes such as such as stress, deformation, torsion, pressure, temperature (pyroelectric) via self-deformation the fiber and / or deformation of the tire. From these measured variables, further measured variables such as Wear or Adhesion can be derived.

Alternatively or additionally, the piezoelectric fiber serves as a generator for the energy supply the tire measuring device or parts thereof. For example, the tire measuring device can have transmission means for operating a radio interface, in particular in the high-frequency range, which are supplied with energy by the piezoelectric fiber. A temperature or pressure sensor could also be operated with this type of energy supply.

There can be only one, but also one Variety of piezoelectric fibers are used, which then for example, are arranged in a grid and / or network.

By a suitable laying and execution the fibers can continue to do this Care should be taken that forces ME decisive only for certain spatial directions of the force effect to an electrical Lead tension. That way you can the mechanical characteristics for all spatial directions can be determined separately or can be a multi-dimensional one Force / voltage vector can be detected.

Preferably, the piezoelectric Fiber, in particular even the entire tire measuring device, in the Tires arranged.

The piezoelectric fiber runs here especially in the tire cover / carcass. But alternatively is a course in the tire flank is possible.

If the piezoelectric fiber is along of the circumference of the tire is arranged in the tire cover during the normal rolling of the tire a very intense and if necessary additionally in their changing behavior further information about the tire on the piezoelectric fiber. Alternative or complementary preferred Arrangements are axial in the tire roof and radial in the tire flank.

For the production of the tire it may be advantageous that the piezoelectric Fiber on the steel belt arranged and / or braided in the steel belt.

When the piezoelectric fiber is used Power supply is used, the tire measuring device can have a rectifying element and / or an energy store, to match the electrical energy generated by the piezoelectric fiber prepare.

A very inexpensive and robust design results itself when ambient energy in through the piezoelectric fiber a changeable variable is and the tire measuring device has a reflector which over the Modular size adjustable is.

The reflector is preferably a Reflector for an electromagnetic signal, especially for a high-frequency signal. This Radio wave reflector is from a distance from a base station can be irradiated with a radio signal. This radio signal is preferably located in the frequency range 100 kHz to 100 GHz. That from the base station transmitted signal is reflected on the radio wave reflector. To the tire measuring device preferably has an antenna. The Tire measuring device thus forms an energy self-sufficient backscatter transponder.

Because the reflector by said Changing size in his Reflection factor is modulated on the radio wave reflector reflected signal imprinted a modulation. The base station receives this modulated reflection signal of the sensor and evaluates it. By the modulation is the reflected signal from other fixed reflections, e.g. on objects, that are in the detection range of the sensor very easy to distinguish.

The tire measuring device is preferably set up, around a measurement in the form to measure a sensor size to be measured.

In the simplest case, the measured variable can the change size be the modulation itself in the radio signal. Then the converter changes the environmental energy depending the measured variable into the alternating variable, so that the measurand over the Modulation of the reflector is measurable.

Alternatively or additionally in a somewhat more complicated version of the principle, however, the change size also by the measurand or another characteristic in characteristic Way to be influenced. The tire measuring device has means for this on the change size depending on a To influence the measurand so the measure over the Modulation of the reflector is measurable. These funds are special arranged in or on a feed line, which is the alternating size of the reflector feeds. Suitable means are e.g. condition-based passive filters or attenuators or condition-dependent Energy converter which the alternating signal and thus the modulation depending on characteristic of the measured variable influence or pretend.

The energy to modulate the backscatter for a sensory purpose, the energy of the measured variable or out with changes in Associated parameter Energy events gained and thereby a self-sufficient, remote readable radio sensor educated. The transmitting and receiving part of the base station and the ones used Signals can in principle identical to usual Backscatter systems executed his.

The tire measuring device is preferably a Backscatter transponder.

A method according to the invention results analogously to the tire measuring device. This also applies to his preferred further training.

Other essential advantages and Features of the invention result from the description of an exemplary embodiment based on the figures. It shows:

1 the basic structure of a self-powered modulated backscatter transponder and self-powered remote measurement tire measuring device,

2 an embodiment of an energy self-sufficient modulated backscatter transponder in Form of an energy self-sufficient remote-sensing structure-borne noise sensor,

3 a possible version of an energy self-sufficient modulated backscatter transponder as a temperature sensor,

4 an embodiment with two paths,

5 a tire and a tire measuring device,

6 a tire measuring device with piezoelectric fiber,

7 a tire measuring device with piezoelectric fiber, which is mounted on or in a tire ceiling,

8th a completely ceramic tire measuring device with piezoelectric fiber,

9 an energy self-sufficient tire measuring device with piezoelectric fiber as a piezo generator and

10 a ceramic tire measuring device with piezoelectric fibers.

1 shows the basic structure of a self-powered modulated backscatter transponder and self-powered remote-sensing radio sensor. The energy self-sufficient modulated backscatter transponder EAMBT comprises at least the following components. With the energy converter EW in the form of a piezoelectric fiber, an available ambient energy in the form of an energy change quantity is converted into an electrical change quantity or an alternating signal WSig.

This alternating signal is optional still adjusted with a matching circuit so that it is as a resultant Modulation signal MSig is particularly good for modulating the modulatable Reflector MR is suitable. The original change size in shape of an alternating signal in this case is therefore derived Alternating size in shape a modulation signal converted.

In particular, it can be beneficial if this matching circuit comprises a transformer. The modular one Reflector can e.g. be an antenna whose adaptation to your Input or output is varied with the modulation signal MSig. Dependent from its adaptation, the antenna reflects a radio signal that she receives, more or less strong (amplitude modulation) or reflects it with a more or less big one Phase shift (phase modulation) or reflected depending on Modulation signal MSig different at different frequencies strong (frequency modulation). This effect of the modulated reflection will be in the further execution used the EAMBT backscatter transponder by radio from a distance to query with a base station BS.

The base station includes this at least one signal source S with which the interrogation signal ASig is generated and over a transmitting antenna as a radio signal ASig 'in the direction of the backscatter transponder EAMBT is emitted. This signal is sent to the backscatter transponder EAMBT modulates reflected. The radio signal RSig reflected in this way is transmitted via a receiving antenna received and with a signal comparator SV with the transmitted Query signal ASig compared. Apart from a small delay due to the route from the base station to the backscatter transponder EAMBT and back and if necessary impressed noise the interrogation signal ASig and the reflected radio signal differ RSig only through the modulation that the reflected radio signal RSig through the backscatter transponder EAMBT stamped has been. By comparing the interrogation signal ASig and the reflected one Radio signal RSig can thus directly map MSig 'from the modulation signal MSig are formed in the base station and thus the energy change variable belonging to the measured variable is energy self-sufficient can be measured remotely by radio.

Be designed and applied can the energy self-sufficient according to the invention modulated backscatter transponder and self-sufficient remote-sensing radio sensor in a variety of forms.

2 shows a simple version as an energy self-sufficient, remote-accessible structure-borne noise sensor. The energy converter here is a sound converter SW, preferably a piezoelectric sound or ultrasound converter, in the form of a piezoelectric fiber. If it receives an acoustic signal AkSig, it converts it into an electrical signal. This electrical modulation signal MSig = AkSig ', which is used below for modulating the modulatable reflector, is in principle an image of the acoustic signal. The modulatable reflector preferably comprises a field effect transistor with which the adaptation of its antenna, as already indicated above, is varied. For this purpose, those types of field effect transistors are preferably used which can also be modulated around the operating point 0V, ie without additional bias.

As for the present circuit suitable field effect transistor types would be e.g. the types SST310 from Vishay or MGF4953A from Mitsubishi.

In addition to field effect transistors of course also all other components are suitable, their or their conductance or the reflection or transfer function dependent change from an applied voltage. Would be suitable e.g. Transistors, diodes, varactors, controllable dielectrics, micromechanical Switches or phase shifters (MEMs) etc.

The base station BS contains a fixed frequency oscillator OSZ which generates the interrogation signal ASig. The interrogation signal is emitted via the transmit / receive antenna SEA combined in this embodiment. The transmit / receive antenna SEA also serves to receive the modulated reflected signal RSig. The RK directional coupler is used to separate the transmit and receive signals. The already for 1 The signal comparison described here is carried out by a mixer, ie the transmission signal ASig is mixed with the reflected signal RSig and preferably subsequently filtered with a filter FLT. The filter FLT is preferably designed as a bandpass or lowpass. The cut-off frequencies of FLT should preferably be selected so that they correspond to the limits of the frequency range of interest of the acoustic signal AkSig or those of the modulation signal MSig. The mixer arrangement shown separates the modulation, ie in principle the modulation signal MSig, from the carrier, ie in principle ASig. At the output of the FLT filter, an image AkSig '' from AkSig 'or AkSig can be picked up and displayed or processed.

In the execution of the shown here Basically, the base station is a standard continuous wave or Doppler radar. All known designs such systems can thus be transferred directly to the solution according to the invention. Also the Possibility, the reflection factor or the adaptation of an antenna via a field effect transistor are to be modulated in various forms State of the art. Known circuits are therefore easy on the transfer solution according to the invention. More concrete versions, are therefore no longer presented by these components here they are known to the expert anyway or in the relevant literature can be read.

At this point it should be particularly pointed out that if the base station is more complicated, it is also possible to determine the distance to a backscatter transponder with modulated reflection. Embodiments that can be transferred to an energy self-sufficient modulated backscatter transponder EAMBT can be found in M. Vossiek, R. Roskosch, and P. Heide: "Precise 3-D Object Position Tracking using FMCW Radar", 29th European Microwave Conference, Munich, Germany, 1999, and in the documents DE 19957536 A1 . DE 19957557 A1 and especially in DE 19946161 A1 ,

As a query signal from the base station the frequencies are preferably used, as they are otherwise cheap for transponder systems and usual are, e.g. 125 kHz, 250 kHz, 13.7 MHz, 433 MHz, 869 MHz, 2.45 GHz or 5.8 GHz. Is cheap that the frequency of the interrogation signal is significantly higher - e.g. around the factor 10 - as the frequency of the alternating variable WSig chosen because then in the base station the carrier, i.e. the interrogation signal, can be separated from the modulation, i.e. WSig, with simple means can.

Based on the previous versions, however also much more advanced sensor and identification systems will be realized. The basic idea here is that the AC signal generated by the converter is no longer directly the exclusive Sensor information includes, but that this signal through a further effect or another measured variable in its nature characteristically changed will and from the size of the change the measured variable is derived in the base station can be. The characteristic change could of course also be in the sense of coding be conscious and defined with the aim of identifying objects to be able to.

The basic idea of the further development is based on the simple design in 3 shown. In principle, it is the same configuration as in 2 , The difference is that the electrical alternating variable AkSig 'is now not used directly for modulating the modulatable reflector MR, but is previously filtered, for example by a temperature-dependent bandpass filter TBPF, depending on the temperature. For example, the temperature of a tire can be measured. The detuning of the filter can easily be implemented by temperature-dependent resistors or the like.

Suppose the frequencies of the acoustic Signals are over a longer one Observation period over the detuning range of TBPF almost equally distributed or the distribution is approximately known, so is the spectral power density distribution or derived quantities such as e.g. the center of gravity or the maximum of the spectrum of AkSig '' is a direct measure of the temperature. For example by a Fourier transformation from AkSig '' in an evaluation unit AE could these values are easily derived.

In addition to filtering, of course, are also others due to measurands Influencing the changing variable WSig conceivable for coding the measured variable. Would be suitable e.g. Runtimes, phase shifters, attenuators. Using Of filters, resonator filters with bandpass or bandstop characteristics are special suitable because on the one hand their influence on the signal properties can be evaluated with simple means and, on the other hand, simple can be realized. As well would be conceivable it that the transducer itself through a physical or chemical Size in its Change characteristics are changed characteristically, i.e. that e.g. the frequency of a sound transducer depending on temperature or depending on mechanical boundary conditions such as pressure or tension.

Not only temperature sensors can be realized in this way, but also pressure sensors, humidity sensors or chemical sensors that can be remotely queried in an energy self-sufficient manner in a similar manner. In principle, any passive sensor element is suitable, with which the modulation signal MSig can be changed in a characteristic manner. Of course, the modulation signal MSig does not have to be used exclusively as a carrier for the sensor information; already shown above, also carry sensor information itself.

When representing the execution in 3 it was assumed that the condition, such as the spectral distribution of the alternating variable WSig, is known. However, this cannot always be assumed. Consequently, it is not always possible with a design as simple as in 3 to determine or transmit exact measurement data. 4 shows an implementation that solves this problem.

It is indicated here that the alternating variable WSig e.g. by a piezo element PE in the form of a piezoelectric fiber derived from a mechanical variable becomes. Essential in the execution is that the alternating signal WSig is split into at least two paths and is processed differently on these paths. to The backscatter transponder can implement a temperature sensor EAMBT e.g. a temperature-dependent filter network TFNW1 in each path or TFNW2. These filter networks can e.g., as before has been described as a frequency-determining filter, delay element, Phase shifter or attenuator accomplished his.

The key is that influencing that TFNW1 and TFNW2 applied to the alternating variable WSig, in a characteristic way different from the measurand - so here the temperature temp - are dependent. The resulting differently influenced modulation signals MSig1 and MSig2 are then based on the previously described query principle on separate channels, e.g. about separate frequency bands to separate base stations BS1 and BS2, and are transmitted there, as previously shown, reconstructed as signals MSig1 'and MSig2'. The signal comparison and evaluation unit SVAE, can then be based on the known properties of the Filter networks TFNW1 and TFNW2 the temperature measured value Temp and / or an image of the alternating variable WSig derived.

The signal comparison and evaluation unit preferably comprises SVAE has a processor for this. The basic idea of the execution exists So in it, the measure is not more directly from absolute characteristic quantities of a signal, but derived from a relative comparison between at least two signals MSig1 'and MSig2'. hereby can be prevented that much better changing and unknown properties of the changing size WSig interfere with the evaluation and the derivation of the measured variable.

Are the filter networks TFNW1 and TFNW2 e.g. as temperature dependent Runtime elements designed, the term difference between characteristically change the two signal paths with the temperature, for example the transit time difference of the signals MSig1 'and MSig2', which is then a measure of the temperature is easily determined using a cross correlation between MSig1 'and MSig2'. The location of the maximum of the cross correlation would be e.g. a measure of temperature. When using temperature dependent Phase shift elements in TFNW1 and TFNW2 could also be a simple analog or digital phase comparator perform a comparable function.

The version shown represents only one possible Variant. As already shown above, can the same kind of course also other measurands such as such as tire pressure, tension, elongation and friction value, frictional connection, Pavement texture, Rolling resistance, aquaplaning, tire wear etc. directly or indirectly be determined. Methods for this are described, for example, in J. Stöcker et al .: “Detection inhomogeneous adhesion conditions between tires and road surface using the example of aquaplaning ", VDI report no. 1088, pages 345 to 369, 1993. It would also be conceivable to split the at least two paths not only in the level of the filter networks dependent on measured values perform, but to use at least two separate energy converters.

5 shows an embodiment of a tire measuring device in the form of a tire sensor with backscatter transponder EAMBT. For this purpose, the structure-borne noise transducer of the backscatter transponder EAMBT in the form of a piezoelectric fiber PZF is coupled to the tire cover or vulcanized into the tire.

Advantage of the principle and the execution is that the tire measuring device through its simple structure and dispensing with a battery can be carried out extremely easily can and therefore easy to attach to fast rotating parts and is to be operated and possibly even vulcanized into the tire can be.

As a query signal from the base station the frequencies are preferably used, as they are otherwise cheap for transponder systems and usual are, e.g. 125 kHz, 250 kHz, 13.7 MHz, 433 MHz, 869 MHz, 2.45 GHz or 5.8 GHz. Is cheap that the frequency of the interrogation signal is significantly higher - e.g. around the factor 10 - as the frequency of the modulating signal is chosen because then in the base station the carrier, thus the interrogation signal, with simple means from the modulation can be separated.

As acoustic or mechanical Energy converters are based on piezoelectric composites used on piezoelectric fibers.

Due to their flexibility, piezoelectric fibers integrated in fiber composite materials offer optimal mechanical structural conformity between the base material and the active piezo component, which would not be possible with conventional piezo foils or ceramics. These structures are therefore particularly suitable for this on a tire ceiling or even vulcanized into a row or a tire.

Basic descriptions of such Fiber composite elements can be found in B.Z. Janos, N.W. Hagood: "Overview of active fiber composites technologies ", Proceedings of the 6th International Conference on new Actuators, ACTUATOR98, June 98, Bremen, Germany or in K. Pannkoke, T. Gesang, M. Clüver, D. Sporn and A. Schörnecker: “Structurally compliant integrable function modules based on PZT fibers ", ADAPTRONIC CONGRESS 1999, March 3-4 in Potsdam, pp. 138-143. The fibers and composites specified there are for execution the invention particularly suitable and as such part of this invention.

In addition to these mechanically for the application according to the invention optimal properties, but piezo fibers also offer excellent possibilities for the purpose of tire sensors. So the fibers in or on the tire cover attached that the mechanical tension to the Tire tread elements for expansion, compression or bending of piezo fibers, this is how the mechanical load profile is formed between the profile elements and the road surface in an equivalent electrical AC voltage.

As with the 1 to 4 described, this alternating signal can be transmitted to a base station by radio according to the EAMBT principle.

An embodiment of a backscatter transponder EAMBT with piezo fiber PZF shows 6 , A schematic of the entire tire sensor system is illustrated 7 ,

This can be generated in the base station and transmitted by radio Alternating signal can then be analyzed and thus on that of power generation underlying mechanical parameters such as adhesion, coefficient of friction, Wear etc. getting closed.

By a suitable laying and execution the fibers can continue to do this Care should be taken that forces ME decisive only for certain spatial directions of the force effect to an electrical Lead tension. That way you can the mechanical characteristics for all spatial directions can be determined separately or can be a multi-dimensional one Force / voltage vector can be detected.

The backscatter transponder EAMBT or central parts thereof can also be designed as a ceramic module when using piezoelectric composite materials. The backscatter transponder EAMBT is here, as in 8th shown, completely realized as a ceramic element, i.e. without any semiconductor element. This ceramic element is divided into different functional layers. A first ceramic layer is used to couple the piezoelectric fibers. This coupling can take place, for example, by coupling the fibers PZF over and / or through channels in a ceramic layer. It would be advantageous, for example, for the PZF fibers to be embedded in the ceramic during the sintering process. However, it would also be conceivable to attach the fibers on and / or to metallic structures on the surface of the ceramic CERAM.

This layer becomes direct or optional if necessary also separated by intermediate layers to a layer DIELL coupled which comprises a controllable dielectric, the paraelectric Has properties. The functionality of this layer DIELL is based on controlling their dielectric constant by an external electrostatic Field generated by a control voltage. The control voltage is as already shown, generated in the piezoelectric fibers. The ceramic functional layer DIELL offers the advantage of a continuous, fast, quasi-powerless control up to the high GHz range and it works as a passive device, i.e. there will be none Semiconductor components needed. The controllable dielectric layer DIELL is made in the same way, as is usually the case with a field effect transistor in backscatter transponders, used to modulate the reflection phase, frequency or amplitude. The controllable dielectric layer could e.g. a ferro or paraelectric Include material systems such as barium / strontium titanate (BST) or BZT as it e.g. in M. Voigts, W. Menesklou, E. Ivers-Tiffee: “Dielectric Properties and Tunability of BST and BZT Thick Films for Microwave Applications ", 13th International Symposium on Integrated Ferroelectrics, Colorado Springs, March 11-14, 2001 is shown. Very suitable as controllable dielectrics are also liquid crystals.

A particularly compact backscatter transponder module arises if the antenna ANT is also a ceramic structure is performed and it represents another layer of the entire ceramic module.

Between antenna ANT and controllable dielectric layer DIELL an antenna carrier ANTSP is arranged.

The entire module can be constructed on the basis of low-temperature sintered ceramics (LTCC low temperature cofired ceramic). It would be conceivable here to embed passive circuits in further layers, which perceive an extended sensor functionality as they do for the 3 and 4 was shown. Discrete components that cannot be integrated into the ceramic can also be arranged on the back of the ceramic.

Since relatively large voltages and currents can be generated with piezoelectric composite structures in the form of piezoelectric fibers, the energy-optimal EAMBT principle does not necessarily have to be used. Alternatively, it is conceivable to rectify the alternating electrical signal that is generated by the piezo fiber composite, and thus to provide an electronic circuit operate.

The basic elements required, their possible designs and interconnection are known from the prior art and can be found, for example, in DE 100 63 305 C1 and PCT / DE01 / 00744.

In contrast to the mentioned stand In technology, however, piezoelectric fibers are used to generate energy and used to generate a tire sensor signal.

The basic execution of the principle shows 9 , The necessary components here are the energy converter as piezo fiber PZF, the rectifying element GE and the energy accumulator EA from which the sensor and transmitter unit SSE is operated. As an option, part of the generated alternating signal is branched off before rectification and fed to the sensor and transmitter unit SSE, so that the information that carries this alternating signal can be transmitted and analyzed.

10 shows the execution of a ceramic energy self-sufficient tire sensor module with piezo fibers. The components required for the sensor and transmitter unit SSE are preferably fitted on the back of the module or integrated into inner layers. Otherwise, the structure corresponds in principle to the ceramic modules shown above.

Furthermore, the antenna element the sensor away from it and only via an electrical line connected, arranged. The one in the tire patch through contact with the road sensor signals are then immediately sent to the antenna, which then advantageously faces the base station antenna. About transformative The steel belt of the tire can also be coupled as a sensor antenna be used.

Claims (14)

Tire measuring device, characterized in that it has a piezoelectric fiber. Tire measuring device according to claim 1, characterized in that that the piezoelectric fiber is a sensor element that is used for measurement one tire size. Tire measuring device according to claim 1 or 2, characterized characterized in that the tire measuring device has transmission means and that the transmission means is generated by the piezoelectric fiber electrical energy can be operated. Tire measuring device according to one of the preceding Expectations, characterized in that the tire measuring device has a grid and / or network of piezoelectric fibers. Tire measuring device according to one of the preceding Expectations, characterized in that the tire measuring device in the tire is arranged. Tire measuring device according to one of the preceding Expectations, characterized in that the piezoelectric fiber at least is partially arranged in the tire cover. Tire measuring device according to one of the preceding Expectations, characterized in that the piezoelectric fiber is approximately is arranged along the circumference of the tire. Tire measuring device according to one of the preceding Expectations, characterized in that the piezoelectric fiber at least partly on the steel belt arranged and / or braided in the steel belt. Tire measuring device according to one of the preceding Expectations, characterized in that the tire measuring device is a rectifying element having. Tire measuring device according to one of the preceding Expectations, characterized in that by the piezoelectric fiber ambient energy convertible into a variable size is and that the tire measuring device has a reflector which over the Modular size adjustable is. Tire measuring device according to one of the preceding Expectations, characterized in that the tire measuring device is a backscatter transponder is. Tire with a tire measuring device after a of the preceding claims. Vehicle with a tire measuring device according to a of claims 1 to 11. Tire measuring method in which a device according to one of the claims 1 to 11 is used.