FR2854101A1 - Wheel tires characteristic acquiring and transmitting process for motor vehicle, involves supplying electromagnetic energy from exterior of vehicle and converting energy in tire region for transmitting size and parameter of tire - Google Patents

Abstract

The process involves producing electrical energy by moving a vehicle and using the energy for detecting and entering size and parameter of a wheel tire (3). The size and the parameter of the tire are transmitted by a transmitter. An electromagnetic energy is supplied from an exterior of the vehicle and converted in a region of the tire for effectuating the transmission of the size and parameter when the vehicle is at rest. An independent claim is also included for a system of acquiring and transmitting a characteristic or a size of a wheel tire of a vehicle.

Description

The present invention relates to a method and a device for

acquisition

  and transmitting a characteristic of a tire for a vehicle as well as a system for entering data.

  Hereinafter, the object of the invention in this sense will be understood, even without any other allusion, the acquisition and transmission of at least one characteristic of at least one tire of a vehicle.

  Knowledge of certain characteristics of tires is of fundamental importance for the safety and also the economy of the operation of a motor vehicle. In particular, a flat wheel tire or one which has an insufficient operating pressure represents a considerable safety risk, taking into account the performance requirements of current motor vehicles. The emergency running properties of modern vehicle tires, positive in themselves, no longer immediately allow a driver of a motor vehicle to immediately detect a tire defect of the kind in question. It is thus possible to drive stably with a flat wheel tire without noticeable deterioration in comfort up to 80 km / h without the driver of the motor vehicle having his attention drawn to this defective state by acoustically or by a significant change in driving behavior. At a higher speed, such a wheel tire 20 suddenly becomes uncontrollable.

  As a result, a vehicle having a flat wheel tire can behave reliably when crossing a built-up area. On the contrary, immediately after arriving on a motorway, the vehicle with a higher speed escapes the driver's control without having received a warning.

  Other disturbances can also occur under the effect of balancing faults, defective adjustment of damping and parallelism on a wheel or even under the effect of faults of an internal structure of the wheel tire. These faults can also cause damage to the wheel tire, which quickly has serious consequences. In particular, they are such as to put the vehicle in a situation of danger out of control, for example in the case of braking at high speed on the highway.

  In the state of the art, various proposals are known which partially tend to remedy such dangers. All these proposals lead to a tire information system which forms part of a very complete driver assistance system. The aim is to achieve the development of two fundamentally different proposals for a tire information system: battery-assisted systems and systems without batteries. Due to the extreme conditions of use of a wheel tire, transmission of the signals by radio or by electromagnetic waves is generally imposed preferably on the electromechanical transmission channels.

  Battery-assisted systems have the advantage that the power supply is carried out both for the measurement of the parameters of the tires, for example the pressure, and for the subsequent radio transmission of information to the vehicle by a battery. A vehicle architecture which is necessary for this presents a low additional expense: all that is required are four electronic tire devices and a central radio receiver equipped with a corresponding signal processing device.

  On the other hand, the drawbacks of battery-assisted tire information systems are serious: a battery placed inside a wheel tire also constitutes a balancing defect which must be compensated at the cost of a corresponding expense . In addition, the wheel tires, in particular those of trucks, have very long service times, that is to say that these tires are extremely durable and therefore remain in service for a long time. A battery must therefore have an extremely long service life in order to guarantee the desired functionality over the entire service life. In addition to the long service life, such a battery must be able to be used reliably over a wide temperature range. An output voltage of traditional batteries would vary quite considerably between the values existing in winter use and those of long-term use in the presence of high summer outdoor temperatures. These specifications, as well as others, currently lead to expensive and all the more voluminous embodiments. For this reason, various battery-free systems have already been proposed in the past, which are based on the following two operating principles: a) The electronic tire device is supplied with energy by an electromagnetic field, which energy is used both for the measurement of tire parameters only for information transmission. In general, this proposal requires four eccentric antennas, which are mounted in the wheel arch region, to provide sufficient field strength.

  Compared to the battery-assisted systems described above, this represents a considerable additional expense in or on a vehicle in question; b) The kinetic energy which is available in the tire in the presence of the movement of the electronic device of the tire is used to power the electronic device, as, for example in what is called an automatic watch, for example at using a piezoelectric generator or using a mechanical generator.

  In general, compared to battery-assisted systems, battery-less systems have the advantage of an almost unlimited lifespan and a lack of maintenance associated with this system. This is why they are chosen as the starting point for a development according to the invention.

  The advantage of proposition b) further consists in the fact that in operation there is always sufficient energy and transmission power to send the information from the tire to a central receiver. In this way, a central radio receiver in a vehicle is sufficient, as is also the case in battery-assisted systems.

  However, the disadvantage of these systems is also obvious: these systems work only in the presence of a movement of the tire since it is only on this condition that kinetic energy is available, for example in the form of vibration. In normal vehicle operation, at a sufficiently high speed, this limitation can generally be accepted.

  The aim of the present invention is to improve a method of acquiring and transmitting characteristics of the tires of a vehicle which is based on the supply of kinetic energy, a device constructed accordingly, as well as a capture system. Datas,.

  According to the invention, this problem is solved by a method for acquiring and transmitting at least one characteristic or a state quantity of a tire of a vehicle wheel, in which an electrical energy is produced by a movement v of the vehicle the electrical energy is used for the detection and / or entry of a state variable and / or a parameter of the wheel tire and the state variable and / or the parameter are transmitted by the intermediate of a transmitter and operated, characterized in that, if necessary, electromagnetic energy is supplied from outside the vehicle under consideration and converted in the region of a tire to effect the emission of state quantities and / or parameters, even when the vehicle is substantially at rest.

  The method according to the invention may also have one or more of the following advantageous characteristics: - the electromagnetic energy is converted into electrical energy; the electromagnetic energy is modulated, in particular by a backscattering device, for the transmission of state quantities and all parameters; an exploitation of the state quantities and / or of the parameters is carried out in a central control unit of the vehicle, in particular in common for all the tires of the vehicle wheels; - during the supply of electromagnetic energy, an operation is carried out on the state quantities and / or parameters outside; - a device of a wheel tire or of all the vehicle wheel tires is subjected to initialization with supply of electromagnetic energy, an individual code being in particular printed and / or learned for the separation of the signals and / or for discrimination; - state quantities and / or parameters of the wheel tire concerned and / or other vehicle wheel tires are stored in a device, in particular in a non-volatile manner; - This method is implemented in combination with at least one other method for the accumulation of electrical energy in the device; - in a moving state of the vehicle and / or of a wheel tire, the supply of electrical energy takes place according to a dynamo principle and / or by taking advantage of vibrations and / or of a deformation of the tire wheel, in particular with the use of a piezoelectric actuator.

  According to the invention, the problem mentioned above is also solved by a device for the acquisition and transmission of at least one characteristic or of a state quantity of a vehicle tire, device which does not have a battery and is equipped with means for producing electrical energy in the presence of movement of the vehicle, these means being connected to at least one sensor intended for detecting and / or entering at least one characteristic or a state variable 25 and / or a parameter of the wheel tire, and connected to a transmitter intended to transmit the state variable and / or the parameter, characterized in that a double supply of energy from the wheel electronics, which is also configured for the conversion of electromagnetic energy which is introduced by radiation from outside the vehicle.

  The device according to the invention can also have one or more of the following advantageous characteristics: - the system is constructed for the transposition of a method according to the invention.

  - the material required in addition to known systems is essentially grouped in the device.

  - there is provided a conversion means for the production of an electrical power supply and / or a backscatter device for the modulation of electromagnetic energy introduced from the outside by radiation, in particular in the form of a surface wave element or resonator filter.

  According to the invention, the problem mentioned above is also solved by a system for acquiring and transmitting at least one characteristic or 5 state quantity of a vehicle tire, system which is in connection substantially without physical contact with at least one device which is without battery and equipped with means for the production of electrical energy during a movement of the vehicle, these means being connected to at least one sensor intended for detection and / or the entry of at least one characteristic, a state quantity and / or a parameter of the wheel tire, and connected to a transmitter intended to transmit the state quantities and / or the parameters, characterized in that that the system is configured, for the supply of electromagnetic energy coming from outside the vehicle, for the reading and the exploitation of the variables of state and / or the parameters of at least one of the tires of wheels of a vehicle icon, in particular according to one of the 15 characteristics of the device according to the invention.

  According to a particular embodiment, the system according to the invention is configured for the execution of statistical measurements and / or the issuing of warnings in the event of diagnosed fault states.

  A device according to the invention is therefore produced in the form of an electronic wheel device for power supply without battery in a state with movement and it is further characterized by the fact that if necessary, it is powered by electromagnetic energy from outside of a affected vehicle. This in particular guarantees the operability of a corresponding device, even in a substantially motionless state. Such a substantially motionless state occurs, for example, during the manufacture of the motor vehicle. Here, with the use of a device according to the invention, in particular assistance with logistics is made possible, for example for the electronic tire devices in question. Furthermore, this also makes it possible to learn or adjust a system for the transmission of a characteristic of one or more tires of a vehicle. We will return to this subject in detail below with reference to the drawings.

  Since a double power supply can be provided for an electronic wheel device with minimal expense, the two operating states, with movement and without movement, can be fully covered. The following technical embodiments can be carried out selectively by a person skilled in the art.

  1. Electronic wheel device with movement: a) dynamo principle, comparable to an automatic watch; b) piezoelectric actuator which captures the vibrations in the tire; c) piezoelectric actuator which captures the deformation of the tire; 2. Electronic wheel device without movement: a) inductive energy supply, which can also be carried out unidirectionally, optionally with charging of an energy accumulator, optional measurement of several parameters of the tire and use of the transmitter radio present to transmit information; b) communication by transponder, which can also be carried out in bidirectional form, for example in the form of an additional communication channel.

  Since an energy supply does not have a fixed frequency in the case of the moving vehicle, a supply of the sensors and of the emission units is, in one embodiment of the invention, based on a supply of direct current or mixed current. Consequently, in a motionless state of the vehicle, the power supply can be effected by means of a transformation of high frequency energy supplied from the outside, also by means of a energy conversion and, in particular, via the quasi-DC power supply mentioned above.

  However, in an advantageous development of the invention, the high frequency energy supplied from the outside in a non-moving state of the vehicle is sent directly to a device called "backscatter" (here called backscatter device). These devices are used as reflectors in which reflected high frequency signals are converted in such a way that they are modulated with a code. Such backscattering devices are known, for example, from the German publication document DE 199 57 557 Ai for use in an identification system for a motor vehicle. Here, an incident high frequency signal is modulated with a fixed code which can be set individually. In this case, the backscattering devices consist of surface wave elements which internally have reflectors with variable modulation. They are made, for example, in the form of a surface wave element or a resonator filter.

  Under the action of a backscatter system, a received signal is provided with an adjustable code 35, so that a return signal thus converted can be distinguished, for example, from any reflections on metallic elements located at the interior of a motor vehicle. In this way, with a reduced total expenditure, an improvement in operating results is obtained.

  Since backscatter systems, constituting coupled high frequency resonators, respond, among other things, to variations in length with a significant shift in modulation, such systems could serve directly as a sensor in embodiments of the invention. invention when disposed on, or incorporated in, a vehicle tire. The pressure existing inside the vehicle tire causes expansion, and therefore, for example a modification of the distances between the coupled resonators. The variations in temperature also determine a variation in the dimensions of the resonators. The two effects can also be used separately from one another or taken into account for an exploitation.

  This method can advantageously also be implemented in combination with at least one other method for the accumulation of electrical energy in the device. It can also be a short-term accumulation or an intermediate buffering.

  The present invention is described below in more detail, for the presentation of other characteristics and advantages, with reference to the accompanying drawing, with the aid of preferred embodiments. In this drawing: FIG. 1 shows a block diagram of an electronic wheel device without battery, with double power supply; Figure 2 shows a schematic plan view of the architecture of the electronic device in a motor vehicle; Figures 3a and 3b show a representation of a system initialization process; and Figure 4 shows another embodiment similar to the representation of Figure 3b.

  In Figure 1, there is shown an electronic wheel device without battery 1 with dual power supply for a motor vehicle. In a moving state, kinetic energy Eki is used, via a generator Gen for the production of electrical energy E. In a quiescent state, electromagnetic energy HF from a field at high frequency or essentially magnetic energy, is supplied from the outside, via an electromagnetic field of the order of kHz, via a receiving antenna IND. 35 The electrical energy E then feeds Sens sensors, a signal processing device SProc and, finally, a radio transmitter FS for wirelessly transmitting corresponding tire information INFO, to a receiver secured to the vehicle, which is not shown. in detail in Figure 1, or to an external receiver.

  In this embodiment, the kinetic energy Ekin and also the electromagnetic energy HF are converted and made available to the Sens sensors of the signal processing device SProc and of the radio transmitter FS, substantially in the form of direct current.

  Thanks to the use of a backscattering device in an alternative embodiment, it would be possible to dispense with a separate energy conversion since coding and transmission of tire information INFO concerned 10 would be carried out directly by the device itself. For this, the high frequency HF electromagnetic energy is converted into a mechanical wave, modulated and reflected as described, inter alia, in the document cited at the start with other references. We will therefore not return here in more detail to this embodiment at this stage.

  FIG. 2 shows a schematic top view of an architecture of an electronic device in a motor vehicle 2. The variant of use indicated by two circles in dashed lines corresponds to that of a tire information system 1 without battery, already known, for each wheel tire. This tire information system 1 uses Ekin kinetic energy, electrically converted, from the motor vehicle 2 which is in motion with a speed v.

  As a result, four tire information systems 1, with their sensor units, accumulators and radios, are active. In this state, they transmit data to an antenna ANT of a central control unit ECU. From there, the information is recorded in a form prepared in driver assistance systems known per se.

  The variant of use b is based on a substantially motionless state of the vehicle 2. The production of Ekin kinetic energy can therefore be neglected.

  However, information from the batteryless tire information systems 1 must be called. This is shown by way of example for a tire on the left front wheel 3: HF electromagnetic energy is sent, via an external antenna Ext ANT to the information system of the tire without battery 1 placed at the inside the wheel tire 3. Then, information recorded in non-volatile form is transmitted back to the Ext ANT outdoor antenna. Methods and devices tolerant to the distance and affected by few parasites are known, which can be implemented for this purpose in a suitable manner, for example, in the form of conversions of external frequencies, etc., by demand. W097 / 45277.

  In this way, a double power supply is provided for an electronic wheel device which covers the two possible operating states, namely in movement and without movement. For this, an inexpensive electronic device architecture is used in the vehicle, since an operation of the 5 electronic wheel devices is here generally sufficient during the movement of the vehicle. In vehicle 2, we therefore dispense with the considerable additional expense of an electronic tire device which would be supplied with energy when stationary by an electromagnetic field, supplied by vehicle 2.

  In FIGS. 3a and 3b, a process of system initialization is shown schematically during the manufacture of the vehicle in a factory. Here, we proceed, in successive steps, firstly to an HF inductive energy supply of the devices 1, after which the devices 1 record their predetermined fixed serial number SNR, or even read it in memory and send it.

  The initialization described above has the following aim: in order to be able to distinguish the signals coming from different electronic tire devices 1, each electronic tire device 1 has a serial number SNR which is transmitted with a radio telegram. When fitting new electronic devices for tires 1 or new tires 3, these serial numbers SNR are recorded in an interior control device so that, in subsequent radio reception, the data sets INFO belonging to the sensors Sens of this vehicle 2 can be distinguished from those of vehicles which are close to it.

  Information on a type of tire considered is also transmitted to a central element. Examples of such data are, in particular information indicating whether summer tires, winter tires or all-weather tires have been fitted, as well as a tire width concerned. The indication of a maximum permissible speed can be supplied in the following steps to a central engine management, in the form of a safety limit, for the regulation of a drive motor of the vehicle 2.

  This is followed, as step 3, by an assignment of POS position of a serial number concerned. This number is used later, especially for logistics purposes and for initializing the system at the vehicle manufacturer.

  Finally, each serial number SNR is programmed in a central control unit ECU by a factory network FAB via a diagnostic interface DIAG in vehicle 2, step 4, with the operation PRG.

  All the aforementioned steps can be carried out when the vehicle 2 is completely stopped since a dual power supply offers unlimited possibilities of communication between an electronic wheel device 1 and the environment, even when the vehicle 2 is stopped: the state without movement or at low running speed, the function of an energy supply is made possible by the internal conversion of electromagnetic energy which is produced outside the vehicle.

  As a variant with respect to the process step shown in FIG. 3b, FIG. 4 shows the possibility of using bidirectional communication: here, the data for the allocation of POS position are transmitted with power supply d a single electronic tire device 1 with electromagnetic energy. Then, this data is transmitted to the ECU unit in the vehicle 2 internally and, from there, transmitted as information to all the other wheel tires 3. The connection with the vehicle 2 for the transmission of the data is thus effected. purely contactless.

  As a variant with respect to FIG. 2 and FIG. 4 which is not shown, in an exemplary embodiment during the variant of use a, that is to say in a moving state of the vehicle 2, the information INFO is stored permanently in a memory in each of the tire information systems 1. It is therefore sufficient, in the same way as in the process step of FIG. 4, to execute an external interrogation to be informed the condition of all 20-wheel tires. An application case for such a system is, for example: a service station with a comfort variant for customer assistance: when purchasing fuel, the condition of all the wheel tires of vehicle 2 is queried automatically from externally. A fault test is carried out with output of an external report which is given to the driver of the vehicle. The system is also configured for the execution of statistical measurements and / or the editing of warnings in the case of diagnosed fault states, such as, for example, too low air pressure in a given wheel tire. It is very rational for an indication of tire faults to be made at a service station, since in general one can sell and fit tires there.

  Starting from a tire monitoring system which is already known, as it already very frequently exists in current motor vehicles, in the context of the embodiments described above and partially represented with reference to the drawing figures, it is proposed a system for measuring, detecting and transmitting one or more state parameters of the tires of a vehicle 2. As a system without a battery in the vehicle, a device according to the invention has a duration of almost unlimited life and therefore it is also advantageously maintenance-free.

  At the cost of a minimal increase in the infrastructure or equipment already present in the passenger compartment of the motor vehicle 1, very reliable information is provided, even to the outside. Thanks to an extension of the operating and analysis capacities, the possibilities of use which have just been exposed can be used as a replacement or even cumulatively for increasing safety in the vehicle. The costs of additional equipment are very limited here. In addition, these are extensions to articles of mass production which are already provided as elements in safety devices of the aforementioned prior art. The upgrade can therefore be performed as a replacement for a compact element which can be standardized. This replacement can be carried out, in particular in the case of light vehicles, also during a replacement of a wheel tire.

Claims (15)

  1. Method for acquiring and transmitting at least one characteristic or state quantity of a wheel tire (3) of a vehicle (2), in which an electrical energy (E) is produced by a movement v of the vehicle (2), electrical energy (E) is used for the detection and / or entry of a state quantity and / or a parameter (INFO) of the wheel tire (3) and the quantity d status and / or parameter (INFO) are transmitted via a transmitter (FS) and operated, characterized in that, if necessary, electromagnetic energy (HF) is supplied from the exterior of the vehicle (2) considered and converted in the region of a tire (3) in order to transmit state quantities and / or parameters (INFO), even when the vehicle (2) is substantially in the state rest.   2. Method according to claim 1, characterized in that the electromagnetic energy (HF) is converted into electrical energy (E).   3. Method according to one of the preceding claims, characterized in that the electromagnetic energy (HF) is modulated, in particular by a backscattering device, for the transmission of state quantities and / or parameters (INFO).   4. Method according to one of the preceding claims, characterized in that an exploitation of the state quantities and / or of the parameters (INFO) is executed in a central control unit (ECU) of the vehicle (2), in particular in common for all wheel tires (3) of the vehicle (2).   5. Method according to one of the preceding claims, characterized in that, during the supply of electromagnetic energy (HF), an operation is carried out on the state quantities and / or parameters (INFO) outside.   6. Method according to one of the preceding claims, characterized in that a device (1) of a wheel tire (3) or of all the wheel tires (3) of the vehicle (2) is subjected to initialization with supply of electromagnetic energy (HF), an individual code being in particular printed and / or learned for the separation of the signals and / or for the discrimination.   7. Method according to one of the preceding claims, characterized in that state quantities and / or parameters (INFO) of the wheel tire (3) concerned and / or other wheel tires (3) of the vehicle (2 ) are stored in a device (1), in particular in a non-volatile manner.   8. Method according to one of the preceding claims, characterized in that this method is implemented in combination with at least one other method for the accumulation of electrical energy (E) in the device (1).   9. Method according to one of the preceding claims, characterized in that, in a moving state of the vehicle (2) and / or of a wheel tire (3), the supply of electrical energy (E) takes place according to a principle of dynamo and / or by taking advantage of vibrations and / or deformation of the wheel tire (3), in particular with the use of a piezoelectric actuator.   10. Device (1) for acquiring and transmitting at least one characteristic or state quantity of a wheel tire (3) of a vehicle (2), which has no battery and equipped with means for the production of electrical energy (E) in the presence of a movement (v) of the vehicle (2), these means being connected to at least one sensor (Sens) intended for detection and / or capture at least one characteristic or state quantity and / or one parameter (INFO) of the wheel tire (3), and connected to a transmitter (FS) intended to transmit the state quantity and / or the parameter (INFO), characterized in that a double power supply is provided to the wheel electronics (1), which is also configured for the conversion of electromagnetic energy (HF) which is introduced by radiation into from outside the vehicle (2).   11. Device (1) according to claim 10, characterized in that the system (3) is constructed for the transposition of a method according to one or more of the preceding claims 1 to 9.   12. Device (1) according to one of the two preceding claims, characterized in that the material required in addition to known systems is essentially grouped in the device (1).   13. Device (1) according to one of the two preceding claims, characterized in that there is provided a conversion means for the production of electrical power supply and / or a backscatter device for the modulation of a electromagnetic energy (HF) introduced from the outside by radiation, in particular in the form of a surface wave element or a resonator filter.   14. System for acquiring and transmitting at least one characteristic or state quantity of a wheel tire (3) of a vehicle (2), which is in connection substantially without physical contact with at least one device (1) which is without battery and equipped with means for the production of electrical energy (E) during a movement (v) of the vehicle (2), these means being connected to at least one sensor ( Sens) intended for the detection and / or entry of at least one characteristic, a state variable and / or a parameter (INFO) of the wheel tire (3), and connected to a transmitter (FS) intended to transmit the state quantities and / or the parameters (INFO), characterized in that the system is configured, for the supply of electromagnetic energy (HF) coming from outside the vehicle (2), for the reading and the '' use of the state quantities and / or parameters (INFO) of at least one of the 15 wheel tires (3) of a vehicle (2), e n particular according to one of claims 10 to 13.   15. System according to the preceding claim, characterized in that the system is configured for the execution of statistical measurements and / or the issuing of warnings in the event of diagnosed fault states. 20