METHOD FOR ESTABLISHING A WIRELESS DATA CONNECTION

Description

[0001] The invention relates to a method for establishing a wireless data connection between at least two vehicles connected to each other via a physical data connection. The invention also relates to a control unit and a communication device.

[0002] Modern commercial vehicles, especially tractors, have a number of control units, such as the engine control unit, transmission control unit, and brake control unit, which can communicate with each other via a CAN bus. A control unit for wireless communication can also be connected to the CAN bus, either for wirelessly transmitting information available to the control units or even for wirelessly transmitting control commands to selected control units.

[0003] The receiver and sender of wireless messages can also be an operator equipped with a suitable communication device. The wireless connection is established using a common standard, such as Bluetooth or Wi-Fi. This allows the driver, as the operator, to establish a connection to the vehicle with their smartphone and retrieve information or transmit control commands.

[0004] Modern trailers also contain control units, at least one brake control unit for an electronic braking system assigned to a pneumatic braking system. The trailer's electronic braking system is connected to the towing vehicle's electronic braking system (and the CAN bus) via a physical data connection in accordance with ISO 11992. Additional subsystems and additional functions, such as air suspension, rear-space monitoring, etc., can be linked to the trailer's electronic braking system. Furthermore, a communication device can be connected to the brake control unit as an additional control unit. The communication device is used for wireless communication with the towing vehicle and / or an operator; see DE 10 2014 015 394 A1. Reference is made to this document in its entirety.

[0005] US20080303648A1 discloses a wired communication unit between a towing vehicle and a trailer, wherein the identification or authentication between the towing vehicle and the trailer is carried out via the wired communication unit and, after identification or authentication, additional wireless communication between the towing vehicle and the trailer is permitted.

[0006] DE102013217684A1 relates to a method for establishing a radio connection for transmitting signals between a transmitter arranged on a trailer and a receiver arranged on a tractor. The method comprises the step of transmitting relevant data for establishing the radio connection via a cable connection connecting the tractor and the trailer. The method further comprises the step of establishing the radio connection between the transmitter and the receiver based on the transmitted data.

[0007] US20020030590A1 discloses a method for exchanging data between a towing vehicle and one or more trailers, particularly for commercial vehicles. The method operates through radio contact via transmitter / receiver modules contained in the towing vehicle and the trailers. To detect the connection between the towing vehicle and the trailer, the transmitter / receiver module of the towing vehicle transmits an identifier via an antenna and simultaneously changes the electrical state of a connecting line. If the transmitter / receiver module located in the trailer detects a change in the electrical state of the connecting line at the same time as receiving the identifier, the received identifier is stored. For subsequent transmissions from the transmitter / receiver modules, the identifier is preceded by each transmission. Only those transmitter / receiver modules that have the same identifier, i.e., that belong to the same vehicle combination, will then respond.

[0008] Automatically establishing a wireless connection between the trailer and towing vehicle makes sense because it saves time. Establishing a wireless connection between two vehicles that are not intended to be connected must be avoided. This is possible, for example, in large depots where many trailers are parked close together. A towing vehicle physically couples to one of the trailers. Subsequently or in parallel, the wireless connection should be established between the trailer and towing vehicle, but not between the towing vehicle and a trailer that is only parked nearby. Likewise, it should be avoided that the towing vehicle and the coupled trailer form a wireless network and then a neighboring trailer establishes a wireless connection to the network.The automatic establishment of a wireless network between towing vehicle and trailer, with verification and authorization of the connection, is known from DE 10 2014 015 394 A1.

[0009] Messages made available to one control unit on the CAN bus are also available to other control units in the same vehicle network. The information is also transmitted via the interface according to ISO 11992, i.e., between the brake control units in the towing vehicle and trailer. The subordinate standard ISO 11992-4 specifies the exchange of diagnostic messages via the interface.

[0010] Diagnostic messages on the CAN bus are defined in the ISO 14229 and ISO 15765 standards, particularly ISO 15765-3. Their primary purpose is to retrieve status and error codes from control units using diagnostic devices connected to an OBD interface. The diagnostic messages are largely standardized, but can also contain empty fields that can be used by vehicle manufacturers for their own purposes related to vehicle diagnostics. Data can also be transferred to control units.

[0011] The object of the present invention is to create a method for establishing a wireless data connection between two vehicles using an existing physical data connection. In particular, a simple, automated, and protected establishment of the wireless data connection should be possible.

[0012] To achieve this object, the method according to the invention has the features of claim 1. In particular, connection parameters of the wireless connection are first transmitted via the physical data connection. The wireless connection is then established using the connection parameters. A physical data connection is any type of line over which data can be transmitted. In particular, it is a data connection based on international standards. By using the physical data connection, it is ensured that exactly the two vehicles that are already physically linked establish a wireless connection with each other. Suitable, unique characteristics of the vehicles involved for identification and parameters required to establish the connection can be exchanged as connection parameters, as can other properties such as passwords, encryption algorithms, etc.

[0013] The wireless data connection between two vehicles is considered the simplest form of a cross-vehicle network. The wireless data connection can be established automatically, for example, by executing steps in suitable software on the devices involved in the data connection. Preferably, the process for establishing the wireless data connection runs automatically, without the need for operator intervention. Only the prior establishment of the physical data connection is required.

[0014] According to the invention, the wireless data connection is established between a towing vehicle and a trailer. However, the method according to the invention can also be applied from trailer to trailer.

[0015] Advantageously, the physical data connection between the two vehicles is a CAN connection according to ISO 11992. This type of connection or interface is widely used as a data interface between towing vehicle and trailer.

[0016] According to a further concept of the invention, the connection parameters are transmitted as part of a diagnostic message from Unified Diagnostic Services (UDS) according to ISO 14229 and ISO 15765, in particular ISO 15765-3. The physical data connection according to ISO 11992 can thus be used optimally for the purposes of the invention. Establishing a radio connection is thereby simplified or automated, especially after coupling a trailer to a towing vehicle.

[0017] According to a further concept of the invention, the wireless data connection between the vehicles is a WLAN connection, with the connection parameters being provided for establishing the WLAN connection. WLAN connections are preferably wireless connections according to IEEE 802.11 (with extensions). Important connection parameters are the SSID and the password for a secure connection.

[0018] According to a further aspect of the invention, the connection parameters contain at least one of the following parameters: SSID, password, identification of at least one of the vehicles, network address, and MAC address. The identifications of electronic control units / communication devices involved in establishing the connection can also be transmitted as parameters.

[0019] According to a further aspect of the invention, the method may additionally have the following features: a) a first communication device and a first control unit are provided in a first vehicle, a second communication device and a second control unit are provided in a second vehicle, b) the two communication devices can communicate with each other via the wireless data connection, c) the first communication device and the first control unit can communicate with each other via a data connection, d) the second communication device and the second control unit can communicate with each other via a data connection, e) after the physical data connection has been established between the first control unit and the second control unit, the first control unit sends the connection parameters for the wireless data connection to the second communication device via the physical data connection and the second control unit, f) after receiving the connection parameters, the second communication device establishes the wireless connection with the first communication device.

[0020] The first control unit received the connection parameters from the first communication device either shortly after or previously. It is also possible that the first communication device transmitted the data; in this case, the first control unit merely acts as a mediator for the message.

[0021] The communication devices are also control units (for communication) and are referred to here as communication devices only for the purpose of better differentiation. It is also possible to integrate the communication device and control unit into a single device.

[0022] According to a further aspect of the invention, the first communication device and the first control unit are connected via a CAN bus. Data is transmitted on the CAN bus, in particular, according to the SAE J1939 network protocol.

[0023] The second communication device and the second control unit can also be connected via a CAN bus.

[0024] The invention also relates to a control unit for implementing the method. This is preferably a brake control unit. The control unit is programmed or provided with software so that the method runs automatically. The automatic execution of the method is preferably initiated by switching on the electrical system in the towing vehicle or by switching on the ignition. The control unit of the first vehicle (the towing vehicle) searches for signals indicating a physical data connection with a second vehicle. As soon as the physical data connection between the vehicles has been established, such information is available.

[0025] The first vehicle can then transmit the connection parameters for the wireless connection via the physical data connection.

[0026] The invention also relates to a communication device for implementing the method. This is preferably at least one control unit suitable for establishing a WLAN connection. Preferably, a connection to another control unit exists via a CAN bus.

[0027] Further features of the invention will become apparent from the description and the claims. Advantageous embodiments of the invention are explained in more detail below using examples. They show: Fig. 1 a simplified representation of control units of two vehicles connected via a CAN bus, Fig. 2 a sequence of procedural steps for coupling a trailer to a towing vehicle and establishing a wireless connection, Fig. 3 another representation of the sequence of process steps, with a connection between client and access point, Fig. 4 a sequence of procedural steps according to Fig. 3 , but resulting in two access points in a WDS network.

[0028] According to Fig. 1 A first vehicle 10 and a second vehicle 11 are connected to each other via a physical data connection 12 according to ISO 11992. In each vehicle, control units are connected to each other via a CAN bus 13, 14. In the first vehicle 10, a first control unit 15 as a brake control unit is coupled to a first communication device 16 via the CAN bus 13. The first control unit 15 is in Fig. 1 additionally referred to as ECU1, the first communication device as WLAN1.

[0029] Analogously, in the second vehicle 11, a second control unit 17 (ECU2) and a second communication device 18 (WLAN2) are coupled to each other via the CAN bus 14.

[0030] The participating control units 15 to 18 communicate with each other via CAN buses 13 and 14. CAN messages from one of the control units are available to the other control units, depending on the addressing. The use of the well-known SAE J1939 network protocol for CAN messages is possible and common.

[0031] The individual control units can also transmit and read diagnostic messages via the so-called Unified Diagnostic Services (UDS) according to ISO 14229 and ISO 15765-3. In this case, such diagnostic messages are used to transmit connection parameters for establishing a wireless connection between the two communication devices 16, 18.

[0032] The first vehicle 10 is preferably a towing vehicle, and the second vehicle 11 is a trailer. The first control unit 15 is the brake control unit of the towing vehicle, while the second control unit 17 is the brake control unit of the trailer. The two brake control units are connected to each other in a known manner via the physical data connection 12 and can also exchange UDS diagnostic messages via this connection in accordance with ISO 11992-4.

[0033] In this example, a wireless data connection is planned between the communication devices 16, 18 via WLAN. The first communication device 16 is configured as an access point and transmits its SSID. The same applies to the second communication device 18, which, as an access point, has its own SSID. The goal is now to establish the WLAN connection between the two communication devices 16, 18. To do this, the first communication device 16 transmits its own SSID, possibly encryption information, and a password via the CAN bus 13, the physical data connection 12, and the CAN bus 14 to the second communication device 18.

[0034] The specified connection parameters are packaged in one or more diagnostic messages from the UDS. The second communication device 18 can use the transmitted data to connect to the first communication device 16 via WLAN. Erroneous connections to other vehicles that do not have a physical data connection to the first vehicle 10 are eliminated.

[0035] The process of establishing the wireless data connection between the two vehicles 10, 11 is carried out in conjunction with Fig. 2 explained. Steps A to F are shown: A: A towing vehicle as the first vehicle 10 and a semitrailer as the second vehicle 11 are not yet mechanically coupled. The communication device 16 in the towing vehicle transmits its SSID via WLAN and is connected to the CAN bus 13 of the towing vehicle. Likewise, the communication device 18 in the trailer is connected to the CAN bus 14 of the brake control unit (control unit 17). The WLAN range of the towing vehicle is represented by a circle 19, which does not yet reach the communication device 18 in the trailer. B: The trailer is mechanically coupled to the towing vehicle. The second communication device 18 is now within the WLAN range (circle 19) of the towing vehicle. C: The towing vehicle and trailer are electrically and pneumatically connected. This also establishes the physical data connection 12 according to ISO 11992, which connects the brake control units (control units 15 and 17). The latter are in Fig. 2 not shown for reasons of space. D: The brake control unit in the trailer is supplied with power via the connection to the towing vehicle and registers itself as a control unit on the CAN bus 13. The brake control unit in the towing vehicle detects from the messages on the CAN bus that a trailer with a control unit has been coupled and forwards this information to the communication device 16. Alternatively, the communication device 16 (which is itself also a control unit) automatically detects from the messages on the CAN bus 13 that a trailer with a control unit has been coupled. Thereupon, or after a defined period of time has elapsed, the communication device 16 in the towing vehicle generates one or more diagnostic messages 20 with information for the wireless connection, in particular its own SSID and the password for the towing vehicle's WLAN.E: The generated diagnostic messages 20 are now available on the towing vehicle's CAN bus 13 and are forwarded by the brake control unit via the physical data connection 12 to the trailer's brake control unit. From there, the diagnostic messages 20, or the information they contain, are sent to the trailer's communication device 18. F: After receiving the information contained in the diagnostic messages 20, the trailer's communication device 18 connects to the towing vehicle's communication device 16. In doing so, the communication device 18 establishes a WLAN 21, which also reaches the communication device 16.

[0036] As a result, communication device 18 (trailer) acts as a client in the WLAN of communication device 16 (towing vehicle). Alternatively, the two communication devices 16, 18 can also establish a shared network via WDS to extend the range of one of the two WLANs 19, 20, or to establish a shared network so that all information available in one of the two WLANs 19, 20 can be accessed by a client outside of either network.

[0037] The individual steps in establishing the client-access point connection are described in Fig. 3 shown. The connection parameters must be transferred from the first communication device 16 (WLAN1) in the towing vehicle to the second communication device 18 (WLAN2) in the trailer. For this purpose, the connection parameters, in particular the SSID and password, are packaged in a UDS diagnostic message, namely as a WriteDataByIdentifier, and sent via the CAN bus. In addition, the first communication device (WLAN1) requests the establishment of a WLAN connection, with the second communication device (WLAN2) being the client. The corresponding UDS diagnostic message is referred to as a RoutineControlRequest. The second communication device 18 (WLAN2) reads the diagnostic messages, extracts the connection parameters, adjusts its own connection settings, and connects to the first communication device 16 (WLAN1) as a WLAN client. The wireless connection exists between WLAN1 as the access point and WLAN2 as the client.

[0038] The structure of the WDS network is based on Fig. 4and the information contained therein. Again, the connection parameters must be transferred from the first communication device 16 (WLAN1) in the towing vehicle to the second communication device 18 (WLAN2) in the trailer. For this purpose, the connection parameters, in particular the SSID and password, are sent as a WriteDataByIdentifier over the CAN bus. Additionally, WLAN1 reads the MAC address of WLAN2. The associated UDS message is referred to as a ReadByIdentifier. Furthermore, the first communication device (WLAN1) requests the establishment of a shared WDS network. The corresponding UDS diagnostic message is referred to as a RoutineControlRequest. The second communication device 18 (WLAN2) reads the diagnostic messages, extracts the connection parameters, adjusts its own connection settings, and connects to the first communication device 16 (WLAN1) as a WDS client. WLAN1 then accepts the connection with WLAN2 to form a WDS network.

[0039] Various standards (ISO, IEEE, SAE) are cited in the preceding text, claims, and figures. Unless otherwise indicated, the versions applicable on the priority date of this application or the following versions are meant: ISO 11992 --> ISO 11992-1: Interchange of digital information on electrical connections between towing and towed vehicles, Part 1: Physical and Data Link Layer, 2001-11-20. ISO 11992-4: Interchange of digital information on electrical connections between towing and towed vehicles, Part 4: Diagnostics, 2003-01-27. ISO 14229 UDS, Part 1: Specification and requirements, 2004-10-07. ISO 15765 Diagnostics on CAN, Part 1: General information, 2003-04-20. ISO 15765-3 Diagnostics on CAN, Part 3: Implementation of diagnostic services, 2003-05-12. SAE J1939-11 Physical layer 250K bits twisted shielded pair, 09 / 2006. IEEE 802.11 --> IEEE 802 Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, 2012-03-29.

Claims

1. Method for setting up a wireless data connection between at least two vehicles (10, 11) which are connected to one another via a physical data connection (12), where, after the physical data connection has been connected, connection parameters of the wireless connection are first transmitted via the physical data connection (12) from the towing vehicle (10) to the connected trailer (11), the wireless data connection between the vehicles (10, 11) being a WLAN connection, the at least two vehicles (10, 11) each being equipped with a WLAN communication module (16, 18) and the connection parameters being provided for setting up the WLAN connection and then the wireless connection being set up with the connection parameters, the physical data connection (12) being a CAN connection according to ISO 11992, in the version applicable on the priority date of this application or as ISO 11992 with ISO 11992-1: Interchange of digital information on electrical connections between towing and towed vehicles, Part 1: Physical and Data Link Layer, 2001-11-20, characterized in that the connection parameters are transmitted as part of a diagnostic message in the form of the Unified Diagnostic Services, UDS, according to ISO 14229 and ISO 15765, in the version of the standards ISO 14229 and ISO 15765 applicable on the priority date of this application or as ISO 14229 UDS, Part 1: Specification and requirements, 2004-10-07, and ISO 15765 Diagnostics on CAN, Part 1: General information, 2003-04-20, the towing vehicle (10) reading out the MAC address of the WLAN communication device (18) in the trailer (11) with a further diagnostic message.

2. Method according to claim 1 or any of the other preceding claims, characterized in that the connection parameters contain at least one of the parameters SSID, password, identification of at least one of the vehicles, network address, MAC address.

3. Method according to claim 1 or any of the other preceding claims, characterized by following features: a) a first communication device (16) and a first control device (15) are provided in the first vehicle (10), a second communication device (18) and a second control device (17) are provided in the second vehicle (11), b) the two communication devices (16,18) can communicate with each other via the wireless data connection, c) the first communication device (16) and the first control device (15) can communicate with each other via a first wired data connection, d) the second communication device (18) and the second control device (17) can communicate with each other via a second wired data connection, e) after the physical data connection (12) has been established between the first control device (15) and the second control device (17), the first control device (15) sends the connection parameters for the wireless data connection to the second communication device (18) via the physical data connection (12) and the second control device (17), f) after receiving the connection parameters, the second communication device (18) sets up the wireless connection with the first communication device (16).

4. Method according to claim 3, characterized in that the first communication device (16) and the first control device (15) are connected via a CAN bus (13) and data are transmitted in particular according to the network protocol SAE J1939, with the version of the SAE J1939 standard applicable on the priority date of this application or as SAE J1939-11 Physical layer 250K bits twisted shielded pair, 09 / 2006.

5. Method according to claim 3 or 4, characterized in that the second communication device (18) and the second control device (17) are connected via a CAN bus (14).

6. Control device for a towing vehicle, characterized in that the control device is adapted to carry out the method according to any of the preceding claims 1 to 5.

7. Communication device for a towing vehicle, characterized in that the communication device (16) is adapted to carry out the method according to any of claims 1 to 5.