DE102008008237A1 - Method for detection of rotation of vehicle wheel, involves assigning rotating vehicle wheel to electronic device, and electronic device is provided with rotation sensor, which detects rotation of vehicle wheel - Google Patents

Abstract

The system for detecting the rotational movement of a vehicle wheel comprises at least one associated with a rotating vehicle wheel mitbewegte with the vehicle electronic device, which is provided with a rotary motion sensor. The rotary motion sensor can detect the rotational movement of the vehicle wheel. The system includes transmitting means for wirelessly transmitting rotational measurement data relating to first rotational sensor readings to a fixed receiver on the vehicle. The electronic device has encryption means by which the rotation measurement data can be encrypted. The electronic device is designed such that at least a portion of the rotational movement measurement data can be transmitted encrypted to the receiver.

Description

The The invention relates to a method for detecting a rotational movement a vehicle wheel according to the preamble of claim 1. The invention further relates to a system for detecting the rotational movement of a Vehicle wheel according to the preamble of claim 25.

The EP 1 260 053 B1 describes a protocol for authenticating a consumable to validate the existence of an untrusted authentication chip. The protocol includes the steps of generating a secret random number and calculating a signature for the random number using a signature function in a trusted authentication chip. The random number and the signature are encrypted using a symmetric encryption function.

The DE 10 2005 018 107 B3 discloses a method for detecting the direction of rotation of motor vehicle tires. The method measures two acceleration signals within a tire. The acceleration signals are processed in a mathematical process so that the direction of rotation of the tire can be determined. From the information of the direction of rotation and the direction of travel to be determined, the lateral location of the tires is determined.

The DE 100 12 458 A1 describes a method for determining the rotational speed of a vehicle wheel to which an acceleration sensor is attached. The rotational speed of the wheel is determined by the frequency ω of an alternating signal caused by the influence of the gravitational acceleration g, which is contained in the acceleration signal supplied by the acceleration sensor. The method can be used in automatic tire pressure monitoring systems to wirelessly assign signals transmitted by a wheel electronics to a specific wheel position on the vehicle.

In the from the DE 10 2005 050 206 A1 known generic method, the current tire pressure of a tire is determined by means of at least one pressure sensor.

through of the tire pressure is calculated an adjusted tire circumference, the the determination of the distance or the speed used becomes. By considering the different Tire circumference due to pressure fluctuations can affect the distance or speed determination can be improved.

The DE 198 56 861 A1 describes a method for assigning identifiers contained in signals sent by transmitters in a tire pressure monitoring system to the positions of the wheels. The sign of a path acceleration occurring at the wheel electronics of the tire pressure monitoring system is determined for each running wheel. In the method, the sign of the change in the centrifugal acceleration occurring during the path acceleration is determined and multiplied by the sign of the path acceleration determined for the respective wheel. By comparing the products determined for the various wheels from these two signs, a distinction is made between wheels on the right side of the vehicle and wheels on the left side of the vehicle.

adversely At the known solutions is that measurement results, from those about the speed or the distance traveled by the vehicle can be derived, easily subject to manipulation can be. For example, the mileage is when buying a used car a decisive factor for the Pricing and therefore often the target of manipulation. Also at tachographs Manipulations are often made, for example, one against the other actual vehicle speed reduced adulterated Vehicle speed to document.

Of the Invention is based on the object, a new method and to propose a new system for detecting the rotational movement of a vehicle wheel, with which the above disadvantage is overcome.

These The object is achieved by a method having the features of the claim 1 and solved by a system having the features of claim 25. advantageous Embodiments of the invention are in further claims Are defined.

In the method for detecting the rotational movement of a vehicle wheel, at least one rotating vehicle wheel is assigned an electronic device which is moved together with the vehicle wheel. The electronic device is provided with a rotary motion sensor that detects the rotational movement of the vehicle wheel. In the method, rotational measurement data relating to the first measurements of the rotational motion sensor is wirelessly transmitted to a fixed receiver on the vehicle. The electronic device has encryption means with which the rotation measurement data is encrypted. At least a portion of the rotational measurement data is transmitted encrypted to the receiver. The term "rotational measurement data" in this text broadly encompasses all measurements (or observations) obtained with the rotary motion sensor information and information and in the narrow sense of the rotational movement sensor measured first measured values or first sensor data and all data derived - in whatever way - from the first measured values of the rotational motion sensor or taking into account the first Measured values are obtained.

On the basis of the measured values of the rotary motion sensor can, for example the distance traveled by the vehicle and / or the speed derived from the vehicle.

Of the Rotary motion sensor measures, for example, one of the speed of the Vehicle wheel dependent physical size.

According to one Embodiment of the method according to the invention will be primary metrics, the second metrics one anyway relate to the primary sensor device present on the vehicle, using the rotation measurement data of a plausibility check subjected to the protection of the primary measurement data from tampering serves. Through the plausibility check can ultimately the input signals of a control unit for control the correctness of the functions of a vehicle, to prevent manipulation of the controller. For example becomes a manipulation in the method according to the invention the primary measurement data by comparing the primary measurement data detected with the rotational movement measurement data.

The addressed primary sensor devices are in different Variants of vehicles already used. In these primary sensor devices For example, it may be a Hall element, arranged on the wheels speed sensor for an anti-lock braking system (ABS) act.

Of the Term "primary metrics" covers in this text in the broader sense all by measurements (or observations) with the information obtained from the primary sensor device and And in the narrower sense the measured by the primary sensor device second measured values or second sensor data as well as all data that - whichever way - from the second measured values of the primary sensor device derived or taking into account the second measured values be won.

For example become the transmitted encrypted rotation measurement data from a decryption means in a final destination receiver decrypted. The receiver and the final destination receiver can, but do not have to match. Rather, the encrypted rotation measurement data can be transmitted via forwarded one or more intermediate nodes from the receiver to the final destination receiver become.

According to one Embodiment of the method according to the invention The transmitted rotation measurement data from a Processing means further processed in the final destination receiver.

For example the rotation sensor provides a predetermined number of pulses each 360 ° rotation of the vehicle wheel.

at an embodiment of the invention The method, as a rotary motion sensor, becomes an acceleration sensor used, with the particular centrifugal accelerations detectable are.

According to one Embodiment of the invention Method is the electronic device with a pressure sensor provided with the pressure in the tire of the vehicle wheel detected becomes. For example, an anyway required wheel electronics a pressure sensor based tire pressure monitoring system (TPMS, Tire Pressure Monitoring System) with comparatively little effort be further developed to prevent rotation measurement data from being manipulated to protect. It is conceivable that the pressure measurement data, the the readings taken by the pressure sensor, and the rotation measurement data be transmitted to the same recipient. It is However, also conceivable, the pressure measurement data to a pressure measuring data receiver and the rotation measurement data to another rotation measurement data receiver transferred to.

According to one Embodiment of the invention Procedure are the pressure sensor and the rotary motion sensor on integrated into a microchip, resulting in a miniaturized design low power consumption of the microchip allowed and further the Advantage of easy installation offers. Micromechanical pressure sensors, for example, working by a capacitive method, are known in the art.

According to one Embodiment of the method according to the invention For example, the electronic device includes one with the rotary motion sensor and the pressure sensor provided transponder, consisting of a Receiver and a transmitter for radio transmission of data. With the transponder information can be received and / or Energy to be absorbed. Furthermore, with the transponder Measurement data, in particular pressure measurement data and / or rotational measurement data, wirelessly transmitted to a reader installed in the vehicle become.

For example If the transponder is designed as an RFID (Radio Frequency Identification) transponder, which can be mass-produced and therefore are particularly inexpensive available.

at an embodiment of the invention Method, the electronic device is wireless, preferably inductively supplied with electrical energy.

According to one Embodiment of the invention Method is the electronic device of a locally the electronic device arranged power supply unit, for example a galvanic cell, supplied with electrical energy.

Around the computational overhead associated with the cryptographic process To keep it as low as possible, it is advantageous if the Rotational measurement data encrypted with a symmetric algorithm where, for example, the individual electronic devices each assigned the same cryptographic key becomes.

at an embodiment of the invention Procedure, the rotational measurement data with an asymmetric Algorithm is encrypted, for example, every electronic Device a different, individual cryptographic Key is assigned.

According to one Embodiment of the invention Procedure, an access control system with original, provided with authorized access control keys. The access control system is designed so that additional and non-original access control key learned can be. Such known from the prior art, access control systems described in more detail below, offer increased security against unauthorized action to the inventive method.

at an embodiment of the invention is that of an electronic Device assigned access control key in the Manufacture of the tire manufacturer's side in the respective electronic Device read-only stored and in addition stored in a database.

According to one Embodiment variant of the invention is a part of a symmetric encryption method stored in the transmitter public Key from a manufacturer-side retrieval device and the access control key associated with the electronic device before transferring from the database to the recipient encrypted with the public key.

For example is calculated from the pressure detected by the pressure sensor and the pressure the rotational speed sensor detected wheel speed of the rolling circumference Derived from the vehicle wheel. This can be done anyway from the pressure sensor and the rotary motion sensor obtained measurement data be used for a further purpose. The determination of the Rolling circumference basically opens up the possibility a monitoring of the tire profile. An excessive one Wear of the tire tread could be detected and a appropriate warning to the driver are issued.

According to one Embodiment of the invention will several, for example, all running wheels a separate electronic device assigned. The rotational movements of the individual vehicle wheels are each separately with the individual electronic devices detected. The vehicle speed is taking into account all detected rotational movements of the individual vehicle wheels derived. For example, it is conceivable to have an average vehicle speed to be determined as an average of the individual Vehicle wheels measured vehicle speeds.

For example if the final destination receiver is an evaluation electronics, which cooperates with a playback device functionally to the measured quantities for visual display bring to. The playback device is, for example, as an instrument cluster executed.

According to one Embodiment of the invention is automatically after a tire assembly create a message prompting you to use the vehicle definable test distance to travel, with the return the test route distance from a test control means an automatic Examination is initiated to the transmitted decrypted Check rotation measurement data for plausibility.

in the Below are embodiments of the invention with reference on the attached drawing a little closer explained.

1 shows a block diagram of an inventively designed system with which the distance and / or the speed of a vehicle can be determined. The system can also monitor the tire pressure of the vehicle. In the invention, a transponder 2 used, which in its basic structure according with the transponder used in the prior art within a TPMS system. The arranged in the tire Trans ponder 2 includes a microchip 1 (hereinafter referred to as TPMS chip) on which a micromechanical pressure sensor 10 , an acceleration sensor 11 and an antenna 12 are integrated. The acceleration sensor 11 , For example, a rotary motion sensor whose operation in the DE 10 2004 017 480 A1 is designed so that it provides a predetermined number of pulses per 360 ° rotation of the vehicle wheel. Out of the accelerometer 11 delivered pulse count (pulses delivered in a period of time) is either in the TPMS chip 1 determines the distances and / or the current vehicle speed and a the first track or a current vehicle speed characterizing the first record via an air interface 7 encrypted to a reader 3 (TPMS reader) sent the encrypted first record in further encrypted form to the transmitter 4 an instrument cluster 6 forwards. Or it becomes a pulse record characterizing second record via the air interface 7 encrypted to the reader 3 transmit the encrypted second record in further encrypted form to the transmitter 4 where, finally, based on the number of pulses, the distance and / or the vehicle speed is determined. After ascertaining the speed or the distance covered, the values of the speed or of the traveled distance for optical display are displayed 5 of the instrument cluster 6 brought. The transmitted data can also be in one with the transmitter 4 connected data storage 8th be stored encrypted.

For the calculation of the driven speed as well as the distance are those of the acceleration sensor 11 supplied pulses together with the tire circumference processed. When the vehicle is moving from the acceleration sensor 11 the number of pulses specified per revolution of the wheel, a distance corresponding to the circumference of the wheel has been covered. The encryption of the first data record and the second data record is carried out according to a cryptographic method, for example according to the DES (Data Encryption Standard) standard. Such a cryptographic method is for example in DE 10 2006 019 466 A1 is therefore not explained in detail in this text. The encrypted data records are by a on the transponder 2 integrated antenna 12 wireless to the reader 3 transfer.

The System S according to the invention comprises an access control system with original, authorized access control keys. The access control system is designed so that additional and non-original access control keys are taught can.

By Such access control systems are known in the art the authorization to access an object and / or for the use of the object by authorized keys demonstrated.

Access control systems For example, they are designed as an immobilizer. With help An authorization can be proved by electronic keys be to start the vehicle and use it. At the vehicle Several immobilizer control units are provided, the are integrated into a distributed immobilizer. If an immobilizer control unit must be replaced, so must the new immobilizer control unit initially initialized, d. H. with a valid and authorized code.

Teaching the TPMS chips to a vehicle-side control unit

The access control keys are known to be unique to each TPMS chip 1 supplied and stored in these. In the event of a tire change, the relevant access control key must be inserted in the TPMS chip 1 of the new tire.

In a first variant of learning the TPMS chips 1 to the control unit 9 is in the control unit 9 set up a kind of central key management of the vehicle. As part of a learning process of a TPMS chip 1 to the control unit 9 is from the transmitter 4 the respective access control key to the TPMS chip 1 transmitted. It is understood that the TPMS chip 1 must be designed to perform the learning process. It is also necessary that TPMS reader and TPMS writer functions are integrated in the TPMS receiver.

In a second variant of learning the TPMS chips 1 to the control unit 9 In the known access control system, a not-shown external diagnostic device is connected to the motor vehicle, which puts the control unit in the initialization state only upon detection of an additional access control key.

Teaching a vehicle-side Control device to the TPMS chips

If on each of the TPMS chips assigned to each tire 1 an individual access control key is deposited, the vehicle-mounted control unit 9 to the TPMS chips 1 be taught in which the individual access control keys from the TPMS chips 1 to the Steuerge advises 9 transmitted and stored in this for later use in the decryption.

An unencrypted transfer of the key from the TPMS chips 1 to the vehicle-mounted control unit 9 However, it can be a weak point in terms of protecting the transmitted data. It is therefore proposed that, for each tire, a different individual access control key is assigned to each tire in the respective TPMS chip for each tire 1 stored read-only and the same access control key is additionally stored in a database. An authorized person can retrieve the respective access control key from the database during a tire assembly and in the control unit 9 to save. The transfer access control key from the database to the controller 9 For example, it can be cryptographically secured using a symmetric method. This is done in the control unit 9 retrieved stored public keys from a manufacturer-side retrieval device and the access control key is encrypted prior to transmission with the public key.

For example, the controller 9 designed so that the driver is asked after a tire assembly by any kind of automatically generated message to cover the vehicle a predetermined distance (for example, 10 meters), so in this "test drive" from the controller 9 An automatic check can be made to determine if the decrypted, from the TPMS chips 1 transmitted data is plausible.

to Equipment of a vehicle can be known a set of winter tires and a set of summer tires belong. For example now ultimately the individual winter tires and summer tires assigned Cryptographic key permanently in the control unit saved to avoid that every time you switch between a Set of summer tires and a set of winter tires. The learning process to reshape is.

In the following, it will be described how the measurement result of a wheel speed sensor of a primary ABS sensor system (not shown) can be verified with the system according to the invention: the travel distance traveled by the vehicle is calculated on the basis of distance pulses, which are generated at the rotation of the wheels. For this purpose, conventional wheel speed sensors are mounted, for example, on the wheel hubs of the driven wheel axle. Each conventional wheel speed sensor generates a constant magnetic field with its magnet. At the wheel hub a metallic gear (impulse wheel) is mounted. As a result of the rotation of the pulse wheel creates a changing voltage induction in a solenoid coil of the conventional wheel speed sensor. The number of changes in the voltage induction corresponds to the number of teeth of the pulse wheel. A 360 ° wheel rotation is represented by a certain number of voltage induction changes. The induced voltage signals are transmitted via copper cables to a control unit of the instrument cluster. The primary measurement data measured by the conventional wheel speed sensor can be compared to that of the acceleration sensor 11 measured rotational movement measurement data and thus a possible manipulation of the primary measurement data of the wheel speed sensor are detected.

1

Microchip, TPMS chip

2

transponder

3

reader

4

evaluation

5

display

6

instrument cluster

7

Air interface

8th

data storage

9

control unit

10

pressure sensor

11

accelerometer

12

antenna

S

invention system

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 1260053 B1 [0002]
• DE 102005018107 B3 [0003]
• - DE 10012458 A1 [0004]
• - DE 102005050206 A1 [0005]
• - DE 19856861 A1 [0007]
• DE 102004017480 A1 [0037]
• - DE 102006019466 A1 [0038]

Claims (41)

Method for detecting the rotational movement of a vehicle wheel, in which at least one rotating vehicle wheel is associated with an electronic device moving with the vehicle wheel, which is provided with a rotary motion sensor which detects the rotational movement of the vehicle wheel, wherein in the method rotary motion measurement data relate to the first measured values of the rotary motion sensor , wirelessly transmitted to a fixed receiver on the vehicle, characterized in that the electronic device comprises encryption means with which the rotational movement measurement data can be encrypted and that at least a portion of the rotational movement measurement data is transmitted encrypted to the receiver. Method according to claim 1, characterized in that that the rotational motion sensor is one of the speed of the vehicle wheel dependent physical variable measures. Method according to claim 1 or 2, characterized that primary measurement data, the second measurement values one on the vehicle relate to existing primary sensor device, using the rotation measurement data of a plausibility check be subjected. Method according to one of claims 1 to 3, characterized in that the transmitted encrypted Rotational motion measurement data from a decryption means be decrypted in a final destination receiver. Method according to one of claims 1 to 4, characterized in that the transmitted rotational movement measurement data be further processed by a processing means in the final destination receiver. Method according to one of claims 1 to 5, characterized in that the rotary motion sensor has a predetermined Number of pulses per 360 ° rotation of the vehicle wheel delivers. Method according to one of claims 1 to 6, characterized in that as the rotary motion sensor, an acceleration sensor ( 11 ) is used. Method according to one of claims 1 to 7, characterized in that the electronic device with a pressure sensor ( 10 ) is provided, with which the pressure in the tire of the vehicle wheel is detected. Method according to one of claims 1 to 8, characterized in that the pressure sensor ( 10 ) and the rotary motion sensor on a microchip ( 1 ) are integrated. A method according to claim 8 or 9, characterized in that the electronic device includes a rotary motion sensor and the pressure sensor ( 10 ) provided transponder ( 2 ) for transmitting the measurement data and / or receiving information and / or energy. Method according to claim 10, characterized in that the transponder ( 2 ) is designed as an RFID transponder. Method according to one of claims 1 to 11, characterized in that the electronic device is wireless, preferably supplied with electrical energy inductively. Method according to one of claims 1 to 12, characterized in that the electronic device of a locally with the electronic device arranged power supply unit electrical energy is supplied. Method according to one of claims 1 to 13, characterized in that the rotational movement measurement data with a symmetric algorithm are encrypted. Method according to claim 14, characterized in that that the individual electronic devices are the same Cryptographic key is assigned. Method according to one of claims 1 to 13, characterized in that the rotational movement measurement data with a asymmetric algorithm are encrypted. Method according to claim 16, characterized in that that each electronic device a different, more individual Cryptographic key is assigned. Method according to one of claims 1 to 17, characterized in that an access control system with original, provided with authorized access control keys with the access control system being designed to be additional and non-original access control key learned can be. Method according to claim 18, characterized in that the access control key assigned to an electronic device is stored in a read-only manner in the relevant electronic device during production of the tire and additionally stored in a database stores. Method according to claim 18 or 19, characterized that one as part of an asymmetric encryption process public key stored in the electronic device retrieved from a manufacturer-side retrieval device and the the access control key associated with the electronic device before the transfer to the recipient with the public key is encrypted. Method according to one of claims 8 to 20, characterized in that from the pressure sensor ( 10 ) detected tire pressure and the wheel speed of the rolling circumference of the vehicle wheel is derived. Method according to one of claims 1 to 21, characterized in that several running wheels a separate electronic device is assigned, the rotational movements the individual vehicle wheels with the individual electronic Devices detected separately and the vehicle speed derived taking into account all detected rotational movements becomes. Method according to one of Claims 1 to 22, characterized in that the end destination receiver is an evaluation electronics ( 4 ) operatively cooperating with a playback device to bring the acquired metrics to optical display. Method according to one of claims 1 to 23, characterized in that after a tire assembly automatically a message is created that prompts with the vehicle to travel a predetermined test route, wherein the Returning the test route from a test control means an automatic check is made to the transmitted decrypted rotation measurement data for plausibility to consider. System for detecting the rotational movement of a vehicle wheel, the system having at least one associated with a rotating vehicle wheel, with the vehicle wheel mitbewegte electronic device, the is provided with a rotary motion sensor, which detects the rotational movement of the vehicle wheel, the system having transmitting means, with the rotational motion measurement data concerning the first measured values of the rotational motion sensor, wirelessly transmitted to a fixed receiver on the vehicle can be, characterized in that the electronic Device has encryption means with which the Rotational motion metrics can be encrypted, wherein the electronic device is designed such that at least a portion of the rotation measurement data is encrypted to Receiver can be transmitted. System according to claim 25, characterized that the rotary motion sensor is designed to be one of the speed the vehicle wheel dependent physical quantity to eat. System according to claim 25 or 26, characterized that the system is designed such that primary measurement data, the second measured values of a primary sensor device present on the vehicle using the rotation measurement data of a plausibility check can be subjected. System according to one of claims 25 to 27, characterized in that an end destination receiver decryption means has, with which the transmitted encrypted Rotary motion data receiver decrypts can be. System according to claim 28, characterized in that the end destination receiver has processing means, with which the transmitted rotational measurement data processed further can be. System according to one of claims 25 to 29, characterized in that the rotary motion sensor designed is a predetermined number of pulses per 360 ° rotation to deliver the vehicle wheel. System according to one of claims 25 to 30, characterized in that the rotary motion sensor as an acceleration sensor ( 11 ) is executed. System according to one of claims 25 to 31, characterized in that the electronic device with a pressure sensor ( 10 ) is provided, with which the pressure in the tire of the vehicle wheel can be detected. System according to claim 32, characterized in that the pressure sensor ( 10 ) and the rotary motion sensor on a microchip ( 1 ) are integrated. A system according to claim 32 or 33, characterized in that the electronic device includes a rotary motion sensor and the pressure sensor ( 10 ) provided transponder ( 2 ) for transmitting the measurement data and / or receiving information and / or energy. System according to claim 34, characterized that the transponder is designed as an RFID transponder. System according to one of claims 25 to 35, characterized in that the system power supply means which are designed to wirelessly connect the electronic device, preferably to supply inductive with electrical energy. System according to one of claims 25 to 36, characterized in that the system has a local on the electronic Device arranged power supply unit for supply the electronic device comprises with electrical energy. System according to one of claims 25 to 37, characterized in that the system is an access control system with original, authorized access control keys is provided, the access control system being designed to that additional and not original access control key can be taught. System according to one of claims 25 to 38, characterized in that several running wheels a separate electronic device is associated with which the rotational movements of the individual vehicle wheels with the individual electronic devices are each separately detectable. System according to one of Claims 25 to 39, characterized in that the final destination receiver is an evaluation electronics ( 4 ) operatively cooperating with a playback device to bring the acquired metrics to optical display. System according to one of claims 25 to 40, characterized in that the system notification means includes, which are designed so that after a tire assembly automatically a message is created that prompts with the vehicle to cover a prescribable test distance, and that the system includes test control means with which when backing up the test route an automatic test causes is transmitted to the transmitted decrypted rotary motion measurement data to check for plausibility.