Abstract:
A method and assistance system drawn to identification-dependent communication that takes place between vehicles. The messages to be transmitted are encrypted by cryptographic methods, wherein the necessary keys for the cryptographic methods are stored in vehicle components which are protected from unauthorized removal and installation by means of protection mechanisms. The method and system make it possible to limit standardized broadcasts to a particular group of users.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is the U.S. national phase application of PCT International Application No. PCT/EP2008/061696, filed Sep. 4, 2008, which claims priority to German Patent Application No. 10 2007 042 031.7, filed Sep. 5, 2007, German Patent Application No. 10 2007 059 831.0, filed Dec. 11, 2007, and German Patent Application No. 10 2008 045 467.2, filed Sep. 3, 2008, the contents of such applications being incorporated by reference herein. 
     FIELD OF THE INVENTION 
     The invention relates to assistance technology for vehicles. In particular, the invention relates to an assistance system for a vehicle, a vehicle having such an assistance system, a method for identification-dependent communication between vehicles, a program element and a computer-readable medium. 
     BACKGROUND OF THE INVENTION 
     Radio communication between individual vehicles which takes place in the form of a general broadcast involves all the vehicles which are in range being addressed simultaneously. In other words, all the vehicles can communicate with all the other vehicles. 
     If the communication is intended to take place only between certain vehicles, it is possible to select a respective one of the particular vehicles individually. In this case, the communication is then between precisely two vehicles. 
     If the vehicle-to-vehicle communication is intended to take place between a multiplicity of vehicles, however, with some vehicles not belonging to said group of particular vehicles, it is necessary to find another solution. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide improved vehicle-to-vehicle communication. 
     The invention specifies an assistance system for a vehicle, a vehicle having such an assistance system, a method for identification-dependent communication between vehicles, a program element and a computer-readable medium. 
     The exemplary embodiments described relate in equal measure to the assistance system, the vehicle, the method, the program element and the computer-readable medium. In other words, the features subsequently cited in respect of the assistance system can also be implemented in the method, the vehicle, the program element or the computer-readable medium, and vice versa. 
     In line with one exemplary embodiment of the invention, an assistance system for a first vehicle is specified, wherein the assistance system has a communication device and also a restriction device. The communication device is used for communication with selected transmission and reception devices. These may be vehicles and/or mobile transmission and reception devices, such as a mobile telephone, which are adjacent to the first vehicle. 
     The restriction device is designed to restrict the communication to the selected transmission and reception devices. The restriction device or at least a fundamental portion thereof is integrated in a vehicle component of the assistance system, said vehicle component having a protection mechanism which protects the vehicle component from unauthorized removal and installation in the assistance system. 
     In other words, it is possible for the communication signals to be transmitted as a broadcast and hence, in principle, to be received by all the vehicles which are positioned in range. However, each vehicle contains a restriction device which ensures that only the vehicles which have actually been selected are able to be involved in the communication. This selection can be made by the user, for example, or else by the manufacturer. In particular, the selection can be set externally by a control center during the operation of the assistance system, for example using a radio transmission link. 
     On the one hand, it is possible for the signal transmitted by the vehicle or mobile appliance to have been modified by the restriction device such that it can be read only by the selected vehicles. This can be done using an appropriate decryption algorithm, for example, which encrypts the data to be transmitted such that only selected receivers can decrypt them. On the other hand, it is alternatively possible for the data to admittedly be able to be read by any receiver, in principle, but for the restriction device to recognize whether the received data are intended for the receiver. Only if the restriction device recognizes that the data are actually intended for this receiver does it release the data for further handling or for reproduction. 
     By way of example, the restriction device may be a piece of cryptographic software. It is also possible for the restriction device to be merely a database with the individual keys for the transmitters and receivers, which are sorted according to different groups, for example. Naturally, the restriction device may also have an appropriate piece of hardware which is designed to perform the encryption and decryption. 
     As an alternative or in addition to encryption of the data, it is also possible for the data to be authenticated, so that the receiver can establish whether it is the “required” receiver. 
     In line with the further exemplary embodiment of the invention, the selected transmission and reception devices are assistance systems which are arranged in vehicles ( 202 ) adjacent to the first vehicle ( 201 ). 
     In line with a further exemplary embodiment of the invention, the selected transmission and reception devices have a mobile communication appliance which is designed to support the assistance system ( 100 ). 
     In line with a further exemplary embodiment of the invention, the restriction device has an encryption device which is designed to encrypt data which are to be transmitted and to decrypt received data, wherein the keys required for the encryption and decryption are stored in the restriction device. 
     In line with a further exemplary embodiment of the invention, the restriction device or the keys required for the encryption and decryption is/are integrated in an ESP controller or in a driver assistance unit. The keys or other software or hardware components required for handling the data which are to be transmitted or which are received may also be integrated in other units, such as in an airbag controller, steering electronics, a central chassis controller for performing driving dynamics tasks, an engine controller, a gearbox controller, a suspension and/or shock-absorber controller, a (central) gateway, a driving authorization controller, a controller for am ambient sensor or directly in an ambient sensor, etc. 
     In this way, it is possible to ensure that the vehicle cannot readily be retrofitted with a corresponding restriction device. This means that it is possible to reduce the risk of misuse. 
     In line with a further exemplary embodiment of the invention, the vehicle component in which the restriction device is integrated is in the form of a separate, standalone module. 
     By way of example, this module can be permanently connected, e.g. welded, to the vehicle frame, for example at a location which is accessible only with very great difficulty. 
     In line with a further exemplary embodiment of the invention, the assistance system has an input device which can be used to select the vehicles which are intended to be involved in the communication. 
     In this way, the user (driver) himself can determine which vehicles are intended to be involved in the communication. By way of example, it is possible for the driver to create particular user groups between which he can select. Each user group is then provided with a dedicated key or a dedicated key pair in order to encrypt and decrypt the messages as appropriate. 
     In line with a further exemplary embodiment of the invention, the selected vehicles are vehicles from a particular manufacturer, vehicles in a particular class or vehicles in a particular model. 
     In line with a further exemplary embodiment of the invention, the selected vehicles are emergency vehicles, rescue vehicles, or are vehicles for short-distance public transport. 
     The relevant groups of vehicles which are involved can be defined by the actual manufacturer when the assistance system is manufactured. 
     In line with one exemplary embodiment of the invention, it is not possible for these groups to be subsequently changed by a user. This further reduces the risk of misuse. 
     In line with a further exemplary embodiment of the invention, the communication unit is designed for communication using Bluetooth, ZigBee, WLAN, WiMax, DSRC or cellular radio (GPRS, UMTS, LTE, etc.). 
     It is also possible to use other transmission protocols. The cited protocols afford the advantage of standardization already having taken place. 
     In line with a further exemplary embodiment of the invention, a vehicle having an assistance system as described above is specified. 
     By way of example, the vehicle is a motor vehicle, such as a car, bus or heavy goods vehicle, or else is a rail vehicle, a ship, an aircraft, such as a helicopter or airplane, or is a motor cycle. 
     In line with a further exemplary embodiment of the invention, a method for identification-dependent communication between vehicles or between a vehicle and a mobile appliance is specified in which data are received from a transmitting vehicle or appliance and it is then established whether the transmitting vehicle (or mobile appliance) is a vehicle (or mobile appliance) which belongs to a selected group of vehicles (or mobile appliances). This is established by accessing a vehicle component of an assistance system in the receiving vehicle, said vehicle component having a protection mechanism which protects the vehicle component from unauthorized removal and installation in the assistance system. 
     In line with a further exemplary embodiment of the invention, a method for identification-dependent communication between components of a vehicle is specified in which data are received from a transmitting component in the vehicle by another component in the vehicle and it is then established whether the transmitting component is a component which belongs to the group of components which are authorized for transmission. It is therefore possible to establish whether a component has been replaced retrospectively (sometimes without authorization). This requires every affected component to have a dedicated restriction unit. A list of possible components which are suitable for this purpose comprises the aforementioned controllers. By way of example, establishing the above involves accessing a vehicle component of an assistance system in the receiving vehicle, said vehicle component having a protection mechanism which protects the vehicle component from unauthorized removal and installation in the assistance system. 
     In line with a further exemplary embodiment of the invention, it is established whether the transmitting vehicle is a vehicle which belongs to a selected group of vehicles on the basis of a cryptographic method, wherein the keys required for the cryptographic method are stored in the vehicle component. 
     In other words, fundamental program elements are integrated or installed in a protected area which cannot readily be replaced or retrofitted. 
     In line with a further exemplary embodiment of the invention, a program element is specified which, when executed on the processor, instructs the processor to perform the method steps specified above. 
     In this case, the program element may be part of a piece of software which is stored on a processor in the assistance system, for example. The processor may likewise be the subject matter of the invention. In addition, this exemplary embodiment of the invention comprises a program element which uses the invention right from the outset, and also a program element which prompts an existing program to use the invention by virtue of an update. 
     In line with a further exemplary embodiment of the invention, a computer-readable medium is specified which stores the program element which, when executed on a processor, instructs the processor to perform the method steps specified above. 
     Exemplary embodiments of the invention are described below with reference to the figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is best understood from the following detailed description when read in connection with the accompanying drawings. Included in the drawings is the following figures: 
         FIG. 1  shows an assistance system based on an exemplary embodiment of the invention. 
         FIG. 2  shows a plurality of vehicles based on a further exemplary embodiment of the invention. 
         FIG. 3  shows a flowchart for a method based on a further exemplary embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The illustrations in the figures are schematic and not to scale. 
     In the description of the figures which follows, the same reference numerals are used for the same or similar elements. 
       FIG. 1  shows a schematic illustration of components of an assistance system  100  which is installed in a vehicle, for example. The assistance system  100  has a control unit  140 , a communication unit  122  with an antenna  123  and has a restriction device  121 . 
     The data to be transmitted, which are transmitted from the control unit  140 , which is in the form of a CPU, for example, to the communication unit  122 , are edited by means of the restriction device  121  prior to sending such that they can only be read by particular receivers. 
     Accordingly, the restriction device  121  is also used to accept received messages and to establish whether they are intended for the respective vehicle. 
     In this way, it is possible to allow vehicle-to-vehicle communication which is restricted to particular groups (e.g. to vehicles from one manufacturer, vehicles in a particular class, or a particular model of vehicle, etc.). For this purpose, the communication is encrypted by cryptographic methods. The necessary key is stored in vehicle components which cannot readily be replaced. By way of example, these are driving dynamics systems, such as ESP, EDS, ASR or ABS, which cannot readily be installed retrospectively and which are also not readily available separately (that is to say are not readily available on the “aftermarket”). 
     This key also allows certain properties to be restricted to certain vehicles, such as emergency vehicles (rescue vehicles, etc.), vehicles for short-distance public transport, etc. 
     The restriction unit  121  can also be fitted directly between the communication unit  122  and the control unit  140 . In that case, the key is still stored in another vehicle component, however. This variant is not shown for the sake of clarity. 
     The control unit  140  has an input unit  126  connected to it. The input unit  126  allows various adjustments to be made for the assistance system and possibly on a navigation unit  120  which is linked thereto. 
     In addition, a visual output unit in the form of a monitor  128  is provided which can be used to output routing information, for example, or else information regarding the group of vehicles which are involved. Furthermore, the routing information can also be output via the audible output unit  127 . Output via the audible output unit  127  has the advantage that the driver is less distracted from what is currently happening in the traffic. 
     A memory element  124 , which is connected to the control unit  140  or is integrated in the control unit  140 , stores the digital map data (e.g. as navigation map data) in the form of data records. By way of example, the memory element  124  also stores additional information about traffic restrictions, infrastructure devices and the like in association with the data records. 
     In addition, a driver assistance unit  125  is provided which is supplied with the digital map data or with other information. 
     For the purpose of determining the current vehicle position, the assistance system  100  has a navigation unit  120  with a satellite navigation receiver  106  which is designed to receive positioning signals from Galileo-satellites or GPS satellites, for example. Naturally, the satellite navigation receiver  106  may also be designed for other satellite navigation systems. 
     The satellite navigation receiver  106  is connected to the control unit  140 . The navigation unit  120  is also connected to the control unit  140 . In addition, there is a direct connection between the navigation unit  120  and the satellite navigation receiver  106 . It is thus possible for the GPS signals to be transmitted directly to the CPU  140 . 
     Since the positioning signals cannot always be received in city centers, for example, the sensor system  119  of the assistance system  100  also has a direction sensor  107 , a distance sensor  108 , a steering wheel angle sensor  109 , a spring excursion sensor  102 , an ESP sensor system  103  and possibly an optical detector  104  for the purpose of performing compound navigation. It is also possible for a beam sensor  105  (radar sensor or lidar sensor) to be provided. In addition, the sensor system  119  has a speedometer  101 . 
     The signals from the GPS receiver  106  and from the other sensors are handled in the control unit  140 . The vehicle position ascertained from said signals is aligned with the roadmaps using map matching. The routing information obtained in this manner is finally output via the monitor  128 . 
       FIG. 2  shows a plurality of vehicles  201 ,  202 ,  203  which are respectively equipped with an assistance system  100 . In addition, a mobile appliance  205  (mobile telephone, PDA, etc.) is provided which is carried in the vehicle  201 . The three vehicles and the mobile appliance  205  can communicate with one another by means of a wireless communication link  204 . 
     Only those vehicles which have an assistance system  100  can be involved in the communication. In addition, communication is possible only for those mobile appliances  205  which have suitable authentication, that is to say belong to a selected group. However, even if the vehicle has such an assistance system  100 , it may be excluded from certain communication if it does not belong to a particular, selected group of vehicles. 
     This allows vehicle-to-vehicle communication and/or vehicle-to-mobile appliance communication which is restricted to particular groups and is accessible only to particular groups. 
     In other words, it is therefore possible to limit standardized communication techniques to a particular group of users. 
     The keys required for the communication are stored in the relevant vehicle component during the actual manufacture of the assistance system. 
       FIG. 3  shows a flowchart for a method based on an exemplary embodiment of the invention. In step  301 , an assistance system in a first vehicle encrypts a message which is to be transmitted using a key which is stored in an ESP controller. In step  302 , the message is transmitted in the form of a broadcast and is received by a plurality of vehicles. In step  303 , the message is decrypted by an assistance system in an adjacent vehicle using a key which is stored in an ESP controller. In step  304 , the received and decrypted message is then forwarded, for example to the control unit  140 . 
     In addition, it should be pointed out that “comprising” and “having” do not exclude other elements or steps, and “a” or “an” does not exclude a large number. Furthermore, it should be pointed out that features or steps which have been described with reference to one of the above exemplary embodiments can also be used in combination with other features or steps from other exemplary embodiments described above.