The invention relates to a method for communicating data between a first communication user arranged at a motor vehicle and a second communication user arranged outside the motor vehicle, whereby the first communication user can be addressed by the second communication user via a network address.
From the state of the art, different methods are known for the data communication between a first communication user arranged at a motor vehicle and a second communication user arranged outside the motor vehicle. For connecting the motor vehicle with an external communication user or a communication user arranged outside the motor vehicle, a bus system in the form of a so-called OBD access (OBD=On-Board Diagnosis) is normally used.
Such an OBD access permits a point-to-point connection with a communication user arranged outside the motor vehicle which, however, has several disadvantages. As a result of the bus system, the quantity of the transferable throughput is limited and relatively low. Special hardware is required for the data transmission, which causes additional costs. In addition, a separate communication infrastructure has to be established. Furthermore, the communication can only take place with a single communication partner simultaneously.
From the state of the art, different approaches are also known for using technologies which, in other technical fields, have become a standard, for methods of the above-mentioned type. It is known, for example, to provide an Ethernet interface in the case of the motor vehicle and, while utilizing an Ethernet connection, to exchange data between a first communication user arranged at a motor vehicle and a second communication user arranged outside the motor vehicle. A special variation of such a method is described in International patent document WO 2005/076103 A2.
However, it is a disadvantage of all of these known methods that they are accompanied by high technical expenditures because, as a rule, either on the vehicle side parallel to the previous OBD interface, completely independent additional communication mechanisms have to be provided, or existing communication structures (such as a CAN bus) have to be expanded by corresponding devices and methods for an interface adaptation.
The methods of the above-mentioned type known from the state of the art also have the disadvantage that no unambiguous addressing of a large number of motor vehicles is possible because, as a rule, the number of addresses available in a network or subnetwork is limited.
It is an object of the invention to provide a simple method for data communication between a first communication user arranged at a motor vehicle and a second communication user arranged outside the motor vehicle, which permits the addressing of a large number of motor vehicles.
According to the invention, the network address of the first communication user is determined by an address management unit arranged outside the motor vehicle and by the address management unit at the first communication user. A dynamic address allocation is permitted in this fashion. The first communication user can be addressed by other communication users by way of the network address dynamically allocated to this first communication user.
The network address is preferably allocated to a central gateway (ZGW) of the motor vehicle by way of which the entire data communication of the motor vehicle toward the outside and from the outside respectively is carried out. Since, as a rule, only a single such central gateway exists in the motor vehicle, the allocated network address will then, as it were, relate to the motor vehicle as such. The vehicle itself can therefore be addressed by other communication users, for example, a diagnostic tester, by way of the network address dynamically allocated to it. In such a case, the central gateway is the first communication user according to the invention.
In principle, one network address respectively can also be assigned to several communication users arranged at a single motor vehicle. However, this case will not be discussed here further without limiting the generality.
In the case of a dynamic address allocation, as it is made possible as a result of the invention, no durably separate unambiguous network address is assigned to a motor vehicle to be integrated in a network. On the contrary, one and the same network address can be assigned to different motor vehicles at different times. The address allocation will then be comparable to that of a DHCP server (DHCP=Dynamic Host Configuration Protocol) known from the state of the art for other technical fields.
A network address assigned to a motor vehicle has to be unambiguous only within the respective network. The number of available network addresses of a network, which is limited as a rule, then only has to be dimensioned to be sufficiently large that all motor vehicle to be simultaneously integrated in the network, can be assigned different network addresses. Non unambiguous network addresses have to be available for all motor vehicles that can potentially be integrated in the network.
The address management unit is preferably constructed as a DHCP server. This has the advantage that systems and methods which are known from the state of the art of other fields and are available at reasonable cost can be used for implementing the invention.
According to a preferred embodiment of the invention, for requesting a network address, a request message containing an unambiguous vehicle identification of the motor vehicle is transmitted by a communication user arranged at the motor vehicle, such as the central gateway, to the address management unit. The request message preferably essentially consists of the unambiguous vehicle identification itself. In principle, the request message can also be sent by a communication user arranged at the motor vehicle, which communication user is not identical with the first communication user according to the invention. However, this request message is preferably sent by the central gateway.
By sending the request message, a vehicle, as it were, can report to the network as soon as it is physically connected with the network. A network address will then be assigned to it, by which it can be addressed by other network users. Instead of a request message, which contains a vehicle identification or essentially consists of this vehicle identification, any other request message can basically be sent for this purpose. However, it is advantageous for an unambiguous vehicle identification to be known at the address management unit. The reason is that, in this manner, an assignment can be made between the unambiguous vehicle identification and the given network address.
Assignment data for the assignment between the unambiguous vehicle identification sent for the request and the then defined network address are preferably stored at the address management unit.
As a result, it becomes possible to unambiguously determined during the dynamic address allocation which motor vehicle is assigned to which network address. The storing can take place, for example, in a list form or table form. The assignment can preferably also take place subsequently; that is, it can be determined which motor vehicle was assigned to which network address. For example, for each motor vehicle once (or within a certain time period) integrated in the network, a network history can be stored with the address management unit, which documents at which time which network address was assigned to the motor vehicle or its vehicle identification.
Because of the fact that it allocates the network addresses to motor vehicles integrated in the network, the address management unit is predestined to store such assignment data for a later use, for example, for the possibility of a query by a network user. The address management unit can therefore carry out the task of an address exchange unit at which the network address pertaining to a vehicle identification can be queried by other communication users.
According to a preferred embodiment of the invention, the functionality of the reproduction of assignment data upon a request of a network user is, however, shifted to a separate address exchange unit constructed separately from the address management unit. Assignment data for the assignment between the unambiguous vehicle identification sent for the request and the then determined network address are stored with an address exchange unit, at which the network address pertaining to a vehicle identification can be queried by other communication users. For this purpose, the assignment data can be transferred from the address management unit to the separately constructed address exchange unit.
The reproduction of assignment data by the address exchange unit will then be comparable to the functionality of a DNS server (DNS=Domain Name Server) known from the state of the art for other technical fields. The address exchange unit is preferably constructed as a DNS server. This has the advantage that systems and methods known from the state of the art and available at reasonable cost can be used for the implementation of the invention.
The unambiguous vehicle identification is preferably the chassis number (vehicle identification number) of the motor vehicle. The vehicle identification number is a wide-spread and proven identification for a motor vehicle. Methods and systems are known from the state of the art for storing the vehicle identification number of a motor vehicle in data form at the motor vehicle and to output it, as required, in a communication-related manner.
According to a preferred embodiment of the invention, the definition or allocation of the network address by the address management unit can also take place as a function of the vehicle identification. The allocated network address can, for example, depend on the vehicle identification such that a certain network address is assigned to a certain vehicle as the preferred address, such as a network address that had already been assigned earlier to the same vehicle.
In the case of the invention, the communication between the first and the second communication user preferably takes place by way of a standard interface, particularly an Ethernet interface. The communication between the first and the second communication user preferably takes place by way of a standard protocol, particularly TCP/IP. The assignment of a network address, for example, an IP address, according to the invention permits the utilization of most modern network technologies as well as of the pertaining systems and methods. As a rule, particularly in the case of high production rates, the utilization of standard systems and methods results in considerable cost advantages and high reliability. In addition, very high transmission rates can be reached. For example, data transmission via the Ethernet can take place which has a transmission rate of up to twenty times the transmission rate of the OBD.
Utilizing the respective communication technology, the invention permits a comfortable addressing of all communication users. To the extent that the communication technology used provides it, the simultaneous communication of one communication user with several other communication users is also contemplated. Thus, the integration of vehicles according to the invention into a network, particularly an Ethernet network, makes it possible that a diagnostic tester communicates simultaneously with several vehicles and/or that several diagnostic testers simultaneously communicate with one vehicle.
According to a preferred embodiment of the invention, on the vehicle side, at the first communication user, an input data stream transmitted during the data communication from the second communication user is converted by way of a vehicle access application to a diagnostic data stream in the data format of a conventional diagnostic communication. The diagnostic data stream is therefore reconstructed on the vehicle side.
In this case, it is advantageous that the structures of a conventional OBD access, which usually already exist nowadays and are often prescribed by law, on the vehicle side as well as on the side of the second communication user, for example, a diagnostic tester, are changed as little as possible.
The diagnostic messages present at the second communication user, for example, a diagnostic tester, in the data format of a conventional diagnostic communication, that is, in the conventional diagnostic message format, are therefore preferably only preprocessed, for example, packetized, such that at the diagnostic tester that they can be transmitted to the first communication user by way of selected standard technology, such as TCP/IP over the Ethernet. For the preprocessing, a consideration of the data has to take place only to the transport level (and above). The data processing at the lower communication-related levels is carried out by the standard components of the standard technology used. The data stream arriving at the first communication user is converted back to the diagnostic message format by corresponding processing steps of the vehicle access application inverse to the preprocessing. Also in this case, the consideration can be limited to the transport level. As a result, the same diagnostic messages are present at the first communication user which had at first been present on the other side of the communication connection at the second communication user. The thereby reconstructed diagnostic data stream can then be processed on the vehicle side in the same manner as known from the conventional diagnostic communication. A very simple vehicle-side implementation of the method thereby becomes possible for which hardly any (or no) vehicle components have to be changed.
Since the diagnostic messages present at the second communication user only have to be adapted to the used transmission technology and at the end of the transmission route have to be reconstructed at the first communication user, the described method provides a very slim transmission protocol with a very low overhead for the transmission of standardized diagnostic messages. Standard diagnostic messages can therefore be transmitted without delay, in a safe manner and without any major scratch buffers into the vehicle and out of the vehicle. A multiplexer (control bytes) preferably permits the expansion to other data types as diagnostic messages.
The OBD access, particularly the OBD plug, of the motor vehicle can preferably still be used in a conventional manner. In the simplest case, a separate connection is provided for the additional used communication technology, for example, the Ethernet. However, according to a particularly preferred embodiment of the invention, free contacts of the OBD plug are utilized to which the signals of the additional used communication technology, for example, the Ethernet are applied. No additional plug-type connection then has to be provided. The conventional OBD connection and the additional communication connection, for example, the Ethernet, are combined in one plug-type connection. As a result, costs are saved for additional plug-type connections. Furthermore, time and expenditures are eliminated for the actual placing of several plugs.
For the vehicle-internal distribution of the signals of different data connections (for example, the conventional OBD connection and the Ethernet), on the vehicle side, a gateway unit can be used which is comparable to the CFFS described in International patent document WO 2005/076103 A2.
According to a further development of the invention, the unambiguous vehicle identification of the motor vehicle can additionally be queried by a network user arranged outside the motor vehicle. For this purpose, the querying network user preferably sends a query message to the network address assigned to the motor vehicle. The motor vehicle responds to this query message with a response message containing the unambiguous vehicle identification of the motor vehicle. An undirected query of all vehicles in a network or network segment by means of a broadcast is also contemplated (such as a query on the broadcast address; all vehicles in a subnet respond).
In this case, the querying network user may basically be any other network user, such as another motor vehicle integrated in the network. The query may also be linked to the condition of an authorization. Only those network users may, for example, be permitted to query who have a special authorization in this respect.
The querying network user may also be a network-side vehicle recognition service. In the case of the latter, a list of several, preferably all motor vehicles which are currently registered, have ever been registered, or are registered for a defined time period in the network can be established by way of the received vehicle identifications of different vehicles. This may, for example, be advantageous for documentation purposes during vehicle production or for vehicle servicing.
It may be the purpose of the query of the vehicle identification by the querying network user to permit an assignment between vehicle identifications and network addresses. The list of a vehicle recognition service preferably also allows an assignment between the vehicle identifications and of one or several assigned network addresses respectively. Such an assignment between a network address and a received vehicle identification, as a rule, is easily possible for the querying network user when the latter has previously addressed the respective motor vehicle in a targeted manner by way of its network address and has then received the vehicle identification as an immediate response. It may nevertheless be advantageous to also transmit the network address together with the vehicle identification to the querying network user. This can further simplify the assignment. In addition, as a result, the network user, for example, a vehicle recognition service, receiving the vehicle identification can carry out an assignment between the network address and the vehicle identification also in cases in which the vehicle identification has been sent to the receiving network user unrequested or upon the request of another network user. It may, for example, be advantageous, after the assignment of a network address by the address management unit, for the vehicle to automatically send its unambiguous vehicle identification together with the assigned network address to a vehicle recognition service. If this takes place in this manner for all motor vehicles registered on the network, the vehicle recognition service will be fully informed concerning the assignment between network addresses and vehicle identification. As another example for a case in which the vehicle identification is sent unrequested or upon a request of another network user to a vehicle recognition service, it is also contemplated that, without thoroughly taking into account the respective network address, a query is sent to all vehicles currently registered in the network.
As described above, such a vehicle recognition service is preferably provided in addition to an address management unit and, as required, an address exchange unit. It also can completely or partially carry out the task of an address exchange unit if the assignment list of the vehicle recognition service permits an assignment between vehicle identifications and network addresses, which can be queried by other communication users. An address exchange unit may also be used for queries as to which network address is assigned to which vehicle identification; whereas a vehicle recognition surface is used for queries as to which motor vehicle is currently integrated in a network.
As a result of the possibility of a direct query or the output of the vehicle identification controlled by another event, an access to an address management unit or an address exchange unit can be avoided when such a unit is overloaded, cannot be reached, or has failed.
It is also contemplated to connect a diagnostic tester directly (without a network) to the motor vehicle. In the case of such a direct connection between the motor vehicle and the diagnostic tester, the direct query of the vehicle identification can also be utilized for determining the vehicle identification by the diagnostic tester.
In individual cases, it may also be simpler with respect to the communication for a network user to carry out a direct query of the unambiguous vehicle identification at a current or potential communication partner than to query it at the address management unit or the address exchange unit. Furthermore, network users not authorized to query the assignment data from the address management unit or the address exchange unit may be provided with the possibility of querying in an individual case the unambiguous vehicle identification of a current or potential communication partner.
It is pointed out that the possibility of a direct query of the vehicle identification may also be advantageous independently of the invention in the case of methods of the above-mentioned type.
According to a preferred embodiment of the invention, the second communication user in accordance with the invention is constructed as a diagnostic tester. The diagnostic tester can then address a motor vehicle, with which it is to be connected, for example, for diagnostic purposes, by way of the network address of the motor vehicle. When the diagnostic tester knows only the vehicle identification of the motor vehicle, the current network address assigned to the vehicle identification, as required, can be queried at an address exchange unit. If a vehicle recognition service is present, the diagnostic tester, as required, can also inquire at the vehicle recognition service as to whether the concerned motor vehicle is currently integrated in the network.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.