Signal transmission apparatus for a subscriber device for a digital data communication system in a vehicle

Abstract

The invention relates to a signal transmission apparatus (100) for a subscriber device (200) for a digital data communication system (300) in a vehicle (400). The data communication system (300) comprises a signal transmission line (310) and is designed to exchange first signals (10) via the signal transmission line (310) at a first transmission rate and a first amplitude. The signal transmission apparatus (100) is designed to exchange second signals (20) for or from the subscriber device (200) via the signal transmission line (310) at a second transmission rate and a second amplitude, wherein the second transmission rate is higher than the first transmission rate, and / or wherein the second amplitude is lower than the first amplitude.

Description

[0001] DESCRIPTION

[0002] Signal transmission device for a subscriber device for a digital

[0003] Data communication system in a vehicle

[0004] The present invention relates to a signal transmission device for a subscriber device for a digital data communication system in a vehicle, to a subscriber device and a digital data communication system, to a method for exchanging signals in a digital data communication system for a vehicle, and in particular to the multiple use of communication interfaces.

[0005] Within vehicles, information such as sensor readings, control commands or requests from a control unit, or warning system messages are exchanged via signals transmitted through signal transmission lines. In commercial vehicles, particularly trucks with or without trailers, articulated lorries, or semi-trailer trucks, such signal transmission lines include fieldbus lines like the bus line in a Controller Area Network (CAN) or a Local Interconnect Network (LIN). Other examples include Ethernet connections or dedicated signal lines, such as those used in some warning or redundancy systems.

[0006] Devices connected to a signal transmission line—including sensors, actuators, communication devices, and control units, sometimes for a multitude of systems—exchange signals over this line. These signals encode information as binary data according to predefined protocols. Such protocols include, for example, CAN or LIN protocols, Common Industrial Protocol (CIP), signal protocols such as the AKP protocol, and Ethernet protocols. These protocols are typically standardized. Standardization ensures compatibility between devices and systems, often supplied by different manufacturers, and guarantees the reliability of information transmission. In addition to the protocols, various technical measures are employed to ensure reliable data transmission within the vehicle.

[0007] One set of precautions addresses errors that occur during data transmission over the signal transmission line. In conjunction with the protocol, this includes designing fieldbus lines with differential signaling. For example, there is a standard to design the signal transmission line in a CAN bus with two wires or fibers, a "CAN High" and a "CAN Low," over which data bits are exchanged by two simultaneous complementary signals. Logical 0 is represented via the CAN High by a signal indicating a voltage elevated relative to a reference voltage for a specific duration, and simultaneously via the CAN Low by another signal indicating a voltage decreased relative to the reference voltage for a specific duration. The voltage difference between the two wires then alternates between 0 V and, for example, 2 V, thereby encoding the data bits. The protocol then defines, among other things, the transmission rate.The timing is the time the voltage is held to represent an information bit. In a CAN bus, the transmission or bit rate is typically specified in bits per second (bps). Common bit rates for CAN buses are 125 kbit / s, 250 kbit / s, 500 kbit / s, and 1 Mbit / s, although other rates are used depending on specific application requirements. The timing associated with each bit, i.e., the duration of a bit, is crucial for proper communication on the bus. This timing is defined by the CAN protocol and ensures that all nodes on the bus can be effectively synchronized.

[0008] Another group of precautions is aimed specifically at preventing failures of the signal transmission line. Here, for example, it is known to provide alternative signal transmission paths. In particular, provisions may be made to switch to another signal transmission line or a wireless signal transmission path in the event of a failure of the primary signal transmission line. However, there remains a need for data security in a vehicle's data communication system. This is especially true for commercial vehicles.

[0009] A contribution to this is provided by a signal transmission device for a subscriber device of a data communication system in a vehicle according to claim 1, a subscriber device according to claim 5, a data communication system according to claim 9, a method according to claim 10, and a computer program product according to claim 12. The dependent claims define further advantageous embodiments of the subject matter of the independent claims.

[0010] The present invention relates to a signal transmission device for a subscriber device in a digital data communication system in a vehicle. The data communication system comprises, in addition to the subscriber device, a signal transmission line to which the subscriber device is connected. The data communication system is configured to exchange first signals with a first transmission rate and a first amplitude via the signal transmission line. This means that the signal transmission line is designed to exchange signals with the first transmission rate and the first amplitude via the signal transmission line, and that the data communication system comprises one or more subscriber devices configured to exchange the first signals with the first transmission rate and the first amplitude via the signal transmission line.In some embodiments, the receiving device itself is a participating device; it is then configured to exchange the first signals with the first transmission rate and amplitude over the signal transmission line. In other embodiments, the receiving device itself is not a participating device; it is then not configured to exchange the first signals with the first transmission rate and amplitude over the signal transmission line. The signal transmission device is configured to exchange second signals with a second transmission rate and amplitude over the signal transmission line. The second transmission rate is higher than the first transmission rate, and / or the second amplitude is lower than the first amplitude. Therefore, at least one transmission rate or...The frequency or amplitude of the first signals and the second signals differs.

[0011] The term "exchange" is intended to mean transferring or sending and / or receiving.

[0012] In exemplary embodiments, the signal transmission device is configured for connection with the receiving device; that is, it can be inserted into the receiving device or directly connected to it. The signal transmission device is designed to exchange information with the receiving device, which is encoded by the second set of signals.

[0013] In particular, the signal transmission device shall be configured to provide information from second signals received via the signal transmission line to the subscriber device and / or to generate second signals based on information from the subscriber device and transmit them via the signal line. The subscriber device is thus configured, based on the signal transmission device, to receive data or information via the first and second signals.

[0014] To send and / or receive information.

[0015] The signal transmission device can, in particular, be a communication unit that is installed in the receiving device or that can be installed in the receiving device. The signal transmission device can then be wholly or partially integrated into the receiving device; the signal transmission device can, in particular, be configured to also perform other functions of the receiving device, either wholly or partially. In exemplary embodiments, the signal transmission device is an interface of the receiving device configured to exchange both the signals with the first transmission rate and the first amplitude and the second signals with the second transmission rate and the second amplitude via the signal transmission line.

[0016] The signal transmission line is designed to transmit signals at both the first and second transmission rates. In exemplary embodiments, however, the signal transmission line is intended for transmitting signals at the first transmission rate, for example, due to an industry standard. The signal transmission line can comprise a wire or a fiber optic cable. In exemplary embodiments, however, the signal transmission line is not a wireless signal transmission path.

[0017] The term "signal" is to be understood in relation to the signal transmission line; it refers to a change in the state of the signal transmission line. The terms "first signals" and "second signals" do not imply a sequence of signals. Rather, they should be understood to mean that signals are characterized by their respective transmission rate and amplitude. First signals and second signals can overlap on the signal transmission line; in particular, the first and second amplitudes can combine to form a single amplitude.

[0018] The first and second signals can be electrical or optical in nature. In exemplary embodiments, the first and second signals are each characterized by a corresponding change in current or voltage; however, the first and second signals can also be light pulses. Transmission can therefore occur via current or voltage, or via light, depending on the signal transmission line.

[0019] The term amplitude can refer, for example, to an electrical voltage, a current, or the brightness of a light pulse. In illustrative examples, the ratio of the first amplitude to the second amplitude can take on fixed values ​​of 2, 5, 10, and 30. In other embodiments, the ratio can vary over time.

[0020] Signals—both first and second—can encode data or information, either wholly or partially. Specifically, a signal can correspond to an information bit or a bit sequence, or it can be part of a bit or a bit sequence. In exemplary embodiments, at least the first signals encode information digitally, i.e., through a sequence of binary signal states ("0" and "1"). The second signals can also encode information digitally. The term transmission rate can therefore mean a number of corresponding signals or a number of bits per unit of time. In particular, the transmission rate can be a bit rate.

[0021] Exchanging initial signals with a first transmission rate and amplitude can thus mean that information is exchanged by signals that have a first amplitude and transmit bits at a first frequency within a time window, while exchanging secondary signals with a second transmission rate and amplitude can mean that information is exchanged by secondary signals (which may be of the same nature as the initial signals) that have a second amplitude and transmit bits at a second frequency within or outside the time window. As already shown, the secondary signals can be superimposed on the primary signals; in particular, the amplitudes of the primary and secondary signals can add up to a total amplitude.

[0022] In some embodiments, however, the second signals can also be, for example, high-frequency short changes in the state of the signal transmission line, which encode information in an analogous manner—for example, via a temporal change in an oscillation frequency or the second amplitude. In such embodiments, the first transmission rate and the first amplitude are therefore fixed in time, and the first signals transmit information digitally, while the second signals transmit information analogously, in particular by modulating the first signals in a high-frequency band (and with a high transmission rate compared to the first transmission rate) and in a range of small amplitudes (compared to the first amplitude).

[0023] First signals and second signals can be designed to transmit the same information or different information.

[0024] The participating device can be, in particular, a control unit. For example, it can be part of an anti-lock braking system (ABS) or an electronic braking system (EBS) in the vehicle. The participating device can be a central control unit or a peripheral control unit, such as for a brake unit at a single wheel of the vehicle. Similarly, the participating device, designed as a control unit, can also belong to another system of the vehicle. For example, this could be a driver assistance system or a monitoring system. The driver assistance system could be, for example, a lane keeping assist system, a turning assist system, adaptive cruise control, an electronic stability program (ESP), hill start assist, emergency braking assist, or adaptive cruise control.

[0025] The receiving device can also be a sensor or sensor device, which, for example, has a speed sensor, a temperature sensor or a pressure sensor.

[0026] The participant device can also be a warning device or part thereof. The warning device can be designed to warn a driver inside the vehicle or other road users in the vicinity of the vehicle. For example, it can be a visual or audible signaling device, such as a warning light, a horn, or a warning siren.

[0027] The receiving device can be a conventional device designed for connection to the signal transmission line and for exchanging the first signals. In exemplary embodiments, the receiving device includes a filter or a choke to filter out interference in the first signals, i.e., signals of the first transmission rate and first amplitude. Since such a filter can also detect second signals, i.e., signals of the second transmission rate and second amplitude, it can be advantageous to design or use the signal transmission device in a transmit channel downstream of the filter or in a receive channel upstream of the filter.

[0028] In exemplary embodiments, the vehicle is a commercial vehicle, and in particular a truck. The commercial vehicle can comprise a tractor unit and a trailer and, for example, be a truck and trailer combination.

[0029] Optionally, the data communication system is a Controller Area Network (CAN). The data communication system can be designed for the exchange of initial signals, specifically by being configured to exchange data between participating devices, including optionally the receiving device, within the CAN network, according to a data transmission protocol (or simply protocol). The initial transmission rate and amplitude are then determined by this protocol. The signal transmission device can be implemented as a CAN controller or a CAN transceiver for the receiving device.

[0030] The CAN bus can be a low-speed or high-speed CAN bus. In particular, the signal transmission line in the CAN bus can be implemented as a differential signal transmission line. In this context, the term "signal" can refer to a change of state in only one of the two wires or fibers of the differential signal transmission line.

[0031] In exemplary embodiments, the receiving device (or, if applicable, the signal transmission device itself) is configured to exchange initial signals according to a conventional, standardized CAN protocol. The initial transmission rate and amplitude are defined by the CAN protocol. Initial signals or data can be exchanged, for example, at an initial transmission rate of 40 kbps, 125 kbps, 250 kbps, 500 kbps, or 1 Mbps. Initial signals or data can be exchanged, for example, with an initial amplitude of 1 V, 1.5 V, 2 V, or 2.5 V relative to a reference voltage. The second transmission rate, on the other hand, can correspond to the transmission of data bits at 50 MHz, 100 MHz, 500 MHz, or 1 GHz. The second amplitude can be, for example, only 0.5 V or 0.1 V above or below an instantaneous voltage (e.g., the reference voltage or the voltage of the initial signal).

[0032] The second amplitude can also depend on the second transmission rate or the second frequency. For example, a lower amplitude may be used for higher frequencies to keep the transmission power below a threshold and thus ensure electromagnetic compatibility for devices located near the signal transmission line. At high frequencies, the transmission power of the second signal can range from 1 to 30 dBm.

[0033] If the data communication system is a CAN, the participating devices of the data communication system, possibly including the receiving device and possibly the signal transmission device, are configured to encode and / or decode and exchange data in corresponding data frames. The CAN protocol can be, for example, a low-frequency CAN protocol or the CAN FD protocol. The signal transmission device can be configured to exchange secondary signals, i.e., signals with a second transmission rate and amplitude, during the exchange of primary signals, i.e., signals with the first transmission rate and amplitude. In particular, the signal transmission device can be configured to modulate secondary signals onto primary signals or to extract modulated secondary signals from primary signals or data frames of received primary signals, i.e., to demodulate them.It is possible for second signals to encode only individual data or information in just one or a few bits. Second signals can also encode data again in their own data frames. Such data frames can be structurally identical to data frames exchanged at the first transmission rate, meaning they can have the same or a similar internal bit sequence.

[0034] The signal transmission device or receiving device can be configured to exchange information via second signals that is not contained in data or data frames and / or for which no exchange via data or data frames is intended, even if the receiving device exchanges such data using the first transmission frequency and amplitude. Often, according to the respective protocol, only certain data (i.e., data with specific information) are arranged in a specific order within the data frames. The protocol may therefore be designed in such a way that it does not provide for the transmission of information encoded by the second signals. Thus, the signal transmission device can be configured to encode additional information into the data frames using signals of the second transmission frequency.This additional information can include, for example, measured values ​​of temperature, pressure, concentration, or environmental conditions. The additional information can also include a command or device instruction, a warning, or a message about a device status. In particular, the receiving device can be located in a trailer of a commercial vehicle and transmit, via the signal transmission device, measurement data from inside the trailer (such as temperature, measured values ​​of a gas or liquid concentration, or pressure in a closed section of the trailer). Similarly, the receiving device can be located in the towing vehicle to send requests for the transmission of such additional information via signals at the second transmission rate and to receive such additional information via signals at the second transmission rate.

[0035] However, the signal transmission device or the receiving device may also be configured to exchange information via the second signals that is also contained in data or data frames of the first signals, and / or for which an exchange via data or data frames is provided that the receiving device exchanges with the first transmission frequency and the first amplitude.

[0036] Alternatively or additionally to the aforementioned CAN, the data communication system includes a Local Interconnect Network (LIN), i.e., a fieldbus in which data is exchanged at the first transmission rate according to a corresponding serial protocol. The receiving device can be a master or a slave device on the LIN's signal transmission line. The preceding descriptions of exemplary implementations of the receiving device and the signal transmission equipment in a CAN network also apply analogously to a LIN network.

[0037] Alternatively or additionally to the aforementioned CAN or LIN, the data communication system includes another fieldbus. This other fieldbus, or its participating devices, including the receiving device, can be configured to exchange signals at the first transmission rate according to a protocol such as FlexRay or the time-triggered protocol (TTP). The preceding descriptions of exemplary embodiments of the receiving device and the signal transmission device for a CAN system also apply accordingly to the other fieldbus. Alternatively or additionally, the data communication system includes an Ethernet system. The Ethernet system, or its participating devices, including the receiving device, can be configured to exchange signals at the first transmission rate according to a protocol such as a Fast Ethernet protocol.The preceding information on exemplary embodiments of the subscriber device and the signal transmission device in a CAN system is to be understood in a corresponding manner for the Ethernet system as well.

[0038] Optionally, the signal transmission line can be a sensor signal line and / or a monitoring signal line. It can, in particular, connect a sensor, such as a speed, temperature, pressure, humidity, acoustic, or concentration sensor, to a control unit. In one embodiment, the signal transmission device can be located within the sensor or a sensor device encompassing the sensor, and in another embodiment, within the control unit. The sensor or sensor device and the control unit are then considered embodiments of the receiving device. However, such a signal transmission line does not necessarily have to be part of one of the aforementioned networks.

[0039] The sensor and control unit can be configured to transmit sensor readings to the control unit via the first signals. These first signals can be defined by a transmission protocol, specifically, for a speed sensor, by the AKP protocol. The sensor can also be configured to transmit additional information (e.g., a temperature reading from a temperature sensor connected to or integrated with the speed sensor), the transmission of which is not provided for in the transmission protocol (as can be the case with certain versions of the AKP protocol), via its signal transmission device using the second signals. For example, the second signals can be modulated onto the first signals within an AKP data frame.Accordingly, the control unit can be configured to receive the second signals along with the respective AKP data frame and demodulate them based on its signal transmission device. The monitoring signal line can, for example, connect a sensor to a warning signal transmitter, such as a warning light. Again, the sensor can be configured to transmit additional information to the warning signal transmitter via signals of the second transmission rate, and the warning signal transmitter can be configured to receive these signals and perform a corresponding action. The corresponding action could, for example, be the emission of a special warning signal that differs from all or some of the warning signals that the warning signal transmitter can emit based on signals of the first transmission rate.

[0040] The monitoring signal line can also be a signal transmission line via which a first receiving device with a signal transmission device of the type described is connected to a second receiving device, which also has a signal transmission device of the type described, wherein the first receiving device is configured to transmit monitoring signals, e.g., as heartbeats, as first signals to the second receiving device via the monitoring signal line. For this purpose, the first receiving device can be configured to send second signals, i.e., signals with the second transmission rate and the second amplitude, to the second receiving device, either temporally between such heartbeat signals or modulated onto such heartbeat signals, based on its signal transmission device. The second receiving device can then receive these second signals based on its signal transmission device.

[0041] In some embodiments, communication via the second signals also takes place between more than two subscriber devices. Specifically, the second signals can be transmitted as broadcasts or with addressing from one device to a specific second device or multiple devices. In other embodiments, the subscriber devices can "hijack" an existing line in an existing system and conduct their communication over it, provided the first existing system is not affected. This utilizes an existing infrastructure to integrate new systems. In other embodiments, the subscriber device may only be able to communicate via the signal transmission line or exchange information encoded by the second signals after the signal transmission device has been installed.In such embodiments, the participating device can thus utilize an existing signal transmission line in an existing data communication system that was not originally intended for this purpose and conduct its communication over it, without affecting communication between participating devices in the data communication system that is based on the exchange of initial signals. In this way, an existing infrastructure can be used to additionally integrate new systems.

[0042] Optionally, the signal transmission device is designed to exchange the second signals together with the first signals.

[0043] As mentioned above, the signal transmission device can therefore be designed to modulate signals of the second transmission rate onto signals that are or are to be sent at the first transmission rate, or to demodulate signals of the second transmission rate that are modulated onto signals of the first transmission rate.

[0044] Exemplary embodiments also relate to a subscriber device for a digital data communication system in a vehicle, wherein the data communication system comprises a signal transmission line and is configured to exchange first signals at a first transmission rate over the signal transmission line. The subscriber device comprises a signal transmission device of the type described above and is configured to exchange second signals at a second transmission rate over the signal transmission line.

[0045] The receiving device can also be configured to exchange the first signals over the signal transmission line. The receiving device can include a filter or choke designed to suppress interference in the first signals. The signal transmission device can be located upstream of the filter in a receive channel or downstream of it in a transmit channel, with respect to the flow of signals. However, the filter can also be configured to allow both first signals (signals with the first transmission rate and amplitude) and second signals (signals with the second transmission rate and amplitude) to pass. The signal transmission device can also be configured to exchange both the first and second signals. The receiving device can be configured to transmit information selectively based on either the first or the second signals.

[0046] Optionally, the participant device is a control unit, a sensor and / or a warning device as described above.

[0047] Optionally, the participant device is trained to exchange initial information based on the first signals and second information based on the second signals.

[0048] The first and second pieces of information can be identical, the same, or similar. This allows for redundant information transmission. Alternatively or additionally, the first and second pieces of information can be different, meaning they have different content. This means that the second pieces of information include measurements, messages, or commands that are not exchanged as the first set of information or based on the first signals. This allows for a significant expansion of functionality compared to a conventional subscriber device.

[0049] The receiving device can also be configured to exchange information via second signals when the signal transmission line becomes overloaded with first signals. For this purpose, the receiving device can be configured to detect the overload. Such an overload might be determined, for example, by the receiving device being unable to exchange first signals for a certain period of time. This can occur, for instance, when a ranking order for transmitting and / or receiving devices is determined by arbitration, and much information is exchanged on the signal transmission line based on first signals—that is, signals with the first transmission rate and amplitude—which, due to the arbitration, are prioritized over information exchanged by the receiving device.In such a case, the participating device can be trained to exchange its information via second signals after, for example, a certain period of time, or to activate its signal transmission device accordingly.

[0050] Optionally, the data communication system includes an additional signal transmission path to which the subscriber device is connected, and the subscriber device is configured to exchange information either based on additional signals via the additional signal transmission path or based on the second set of signals via the signal transmission line. This option can also be configured if the subscriber device is connected to the signal transmission line but does not temporarily or permanently exchange any initial signals via the signal transmission line.

[0051] The receiving device can, for example, be configured to repeatedly exchange information via the secondary signal transmission line during normal operation or routine operation, and, in the event of a failure of the secondary signal transmission path, to exchange this information using signals of the second transmission rate on the secondary signal transmission line. The failure can be due to a physical interruption or damage to the secondary signal transmission path, or it can occur due to an overload of the secondary signal transmission path, which can be defined similarly to the signal line described above. The receiving device can be configured to detect the failure of the secondary signal transmission path. This detection can be based on measuring a signal waveform, a time interval, or an external message, for example, from another system.

[0052] In some embodiments, the further signal transmission path is a first wire or fiber of a differential fieldbus line (e.g., a differential CAN bus as described above, such as CAN-High), and the signal line can be a second wire or fiber of the differential fieldbus line (e.g., CAN-Low). However, the further signal transmission path can also be completely different from the signal line. In both cases, redundancy can be achieved and the reliability of information exchange within the vehicle increased.

[0053] Exemplary embodiments also relate to a digital data communication system for a vehicle, wherein the data communication system comprises a signal transmission line and is configured to exchange first signals at a first transmission rate over the signal transmission line, and wherein the data communication system comprises a subscriber device with a signal transmission device as described above, the subscriber device being connected to the signal transmission line via the signal transmission device. The data communication system may also include a further signal line as described above.

[0054] In exemplary embodiments, the vehicle is a commercial vehicle, in particular a truck with or without a trailer. The commercial vehicle can, in particular, be a truck and trailer combination. In particularly advantageous exemplary embodiments, the commercial vehicle comprises or is a tractor unit and a trailer, and the signal transmission line is configured to connect the tractor unit and the trailer. A first receiving device of the type described above can be located in the tractor unit and a second receiving device of the type described above can be located in the trailer. The first receiving device and the second receiving device are equipped with corresponding signal transmission devices of the type presented, in order to exchange, in particular, second signals, i.e., signals of the second transmission rate and the second amplitude, with each other.

[0055] Exemplary embodiments also relate to a method for exchanging signals in a digital data communication system in a vehicle. The data communication system comprises a signal transmission line and a receiving device connected to the signal transmission line. The receiving device is configured to exchange first signals with a first transmission rate and a first amplitude over the signal transmission line, and the receiving device includes a signal transmission device configured to exchange second signals with a second transmission rate and a second amplitude over the signal transmission line. The method involves exchanging second signals to or from the receiving device over the signal transmission line, wherein the second transmission rate is higher than the first transmission rate and / or the second amplitude is lower than the first amplitude.

[0056] Optionally, the data communication system includes an additional signal transmission path to which the subscriber device is also connected, and the subscriber device is configured to exchange information either based on additional signals via the additional signal transmission path or based on the second signals via the signal transmission line, and the procedure further includes exchanging the additional signals via the additional signal transmission path, detecting a failure, and, based on the detection of the failure, triggering an exchange of second signals via the signal transmission line.

[0057] The signal transmission line can, as described above, be, for example, a conductor of a differential fieldbus line, and the subsequent signal transmission path can be another conductor of the same differential fieldbus line. In this case, the subsequent signals can also be exchanged with the first transmission rate and amplitude (possibly with corresponding signs). In further embodiments, the subsequent signal transmission path can differ from the signal transmission line and / or be designed for the exchange of further signals with a different transmission rate and frequency.

[0058] The failure can occur in the subsequent signal transmission path, in a receiving device, or in the subscriber device. For example, the subsequent signal transmission path may be interrupted, defective, or overloaded. A fault or defect may occur in the receiving device or in the subscriber device.

[0059] Exemplary embodiments also relate to a computer program product with stored software code, which, when the software code is executed by a signal processing machine, is designed to perform a method of the type described above. In particular, the computer program product can be the signal transmission device and the signal processing machine the receiving device.

[0060] Exemplary embodiments of the presented signal transmission device, subscriber device, data communication device and method can also be represented as follows.

[0061] Digital signals on a CAN bus are typically transmitted at frequencies between 500 kHz and 5 MHz on two differential lines. For CAN trailers (ISO 11992), the frequency is even lower at 125 kHz. Without affecting these signals, the signal transmission equipment can be configured to couple high-frequency secondary signals, e.g., at 50 MHz to 1 GHz, onto one or both lines at the transmitter end, i.e., for the receiving device. The information is superimposed on the primary signals using amplitude or frequency modulation and then demodulated at the receiver end.

[0062] However, signals are not coupled to power supply lines, but can be coupled to other existing signal lines, e.g. at least one of the two CAN lines, a LIN interface, a warning lamp line or any other line existing between the two communication participants.

[0063] Advantages of the presented products and methods include, in particular, further possibilities for increasing redundancy and thus the reliability of information transmission within the vehicle. Participating devices with signal transmission equipment of the presented type can be configured for connection to conventional fieldbus lines. There, the participating devices can behave like other devices on the fieldbus and exchange the primary signals provided there, i.e., signals with the primary transmission rate and primary amplitude. In addition, they can also exchange secondary signals, i.e., signals with the secondary transmission rate and primary amplitude, via the fieldbus line. With a differential fieldbus line, the secondary signals can only be placed on one of the two fibers of the fieldbus line.In some embodiments, secondary signals can be exchanged via the signal line if another signal line, through which the corresponding information should have been exchanged, fails. In such a case, the information can even be transmitted via secondary signals under heavy load on the signal line, or when a protocol does not permit information transmission over the signal line.

[0064] Through exemplary embodiments of the signal transmission device, conventional devices designed to exchange primary signals over the signal transmission line can be upgraded or retrofitted to also exchange secondary signals over the same line. This allows for increased reliability of the conventional devices. Furthermore, conventional devices can utilize existing data communication networks—that is, existing infrastructure within a vehicle—to exchange at least certain information based on the secondary signals, independent of a data communication network protocol.

[0065] The embodiments of the present invention are better understood from the following detailed description and the accompanying drawings of the different embodiments, which, however, should not be understood as limiting the disclosure to the specific embodiments, but merely serve for explanation and understanding.

[0066] Fig. 1 shows a signal transmission device according to the present invention.

[0067] Fig. 2 shows first and second signals in an exemplary embodiment.

[0068] Fig. 3 shows first and second signals in an exemplary embodiment of a CAN.

[0069] Fig. 4 shows an embodiment in a CAN Brake

[0070] Fig. 5 illustrates an embodiment of a truck with a trailer.

[0071] Fig. 6 illustrates another embodiment of a truck with

[0072] Trailer.

[0073] Fig. 7 shows a step of a method according to the present invention. Fig. 8 shows steps in a further embodiment of the method. Fig. 1 shows a signal transmission device 100 in a subscriber device 200 of a digital data communication system 300 in a vehicle 400, specifically a commercial vehicle or truck. The signal transmission device 100 is integrated into the subscriber device. The data communication system 300 comprises a signal transmission line 310 configured to exchange first signals 10 with a first transmission rate and a first amplitude via the signal transmission line 310, wherein the subscriber device 200 itself is connected to the signal transmission line 310 and configured to exchange first signals 10 with the first transmission rate and the first amplitude via the signal transmission line 310.The signal transmission device 100 is configured to exchange second signals 20 with a second transmission rate and a second amplitude to or from the subscriber device 200 via the signal transmission line 310, wherein the second transmission rate is higher than the first transmission rate, and / or wherein the second amplitude is smaller than the first amplitude.

[0074] The data communication system 300 comprises a further subscriber device 200' with a further signal transmission device 100', each with corresponding properties as the subscriber device 200 and the signal transmission device 100. The further subscriber device 200' is configured as a communication partner of the subscriber device 100, in particular for communication based on the second signals 20.

[0075] Fig. 2 shows first signals 10 with the first transmission rate and the first amplitude, and second signals 20 with the second transmission rate and the second amplitude in an exemplary embodiment. Here, the first transmission rate is lower than the second transmission rate, and the first amplitude is higher than the second amplitude. The second signals 20 can be modulated onto the first signals 10.

[0076] The first signals (10) can, for example, be signals for a warning light. They can encode, for instance, a heartbeat or other warning signals. The second signals (20) can transmit additional information to the warning light or its control system. This additional information can be intended for operating the warning light (e.g., representing color selection information), or it can be other information for an additional function of the warning light or its control system. The additional information can also be intended for forwarding via the warning light's control system.

[0077] Fig. 3 shows first signals 10 with the first transmission rate and the first amplitude, and second signals 20 with the second transmission rate and the second amplitude in a further embodiment. The first signals 10 are signals transmitted via a first wire or fiber of a differential fieldbus, e.g., a CAN line. For example, the first signals 10 can be signals according to the CAN protocol in the CAN high fiber. Also shown are complementary signals 30 in a second wire or fiber of the differential fieldbus. For example, the additional signals 30 can be those of the CAN low fiber. The second signals 20 are superimposed on the first signals 10. Based on the signal transmission device 100, the second signals 20 are exchanged by the receiving device 200 within a data frame of first signals 10.In some implementation examples, this results in an additional use of a CAN signal.

[0078] Fig. 4 illustrates an embodiment for an additional use of a CAN signal. The CAN can, in particular, be a CAN brake. A receiving device 200 with an integrated signal transmission device 100 and another receiving device 200' with an integrated signal transmission device 100' as communication partners are shown. The receiving device 200 and the other receiving device 200' exchange first signals 10 and second signals 20 via a differential CAN bus line 310. A first fiber 313, e.g., CAN-High, and a second fiber 315, CAN-Low, of the CAN bus line 310 are shown. The receiving device 200 and the other receiving device 200' are configured to exchange second signals 20 via one of the two fibers 313, 135, e.g., CAN-High, based on their respective signal transmission devices 100, 100'.In exemplary embodiments, the participant device 200 and the further participant device 200' can each be control units in a braking system of a commercial vehicle 400.

[0079] In further embodiments, the additional participant device 200' can also be a device separate from the vehicle 400, and in particular, a test or inspection device that is temporarily or permanently connected to the CAN bus line 310 for testing or monitoring purposes. For example, initial signals 10 can be exchanged according to the CAN protocol SAE J1939, which is used for CAN communication in commercial vehicles to transmit information between control units and between control units and testers. This protocol is frequently used in the prior art for standardized communication between devices of, for example, a vehicle manufacturer, an engine / transmission manufacturer, a brake system manufacturer, and / or a test system manufacturer, and can therefore occur both in communication between devices of the vehicle 400 and between devices of the vehicle 400 and, for example, test equipment.Here too, the participant device 200 can exchange 10 additional pieces of information with the further participant device 200', which is designed as a test device, via the CAN bus line 310, in addition to the first signals.

[0080] Fig. 5 illustrates an embodiment of a truck 400 with a tractor unit 410 and a trailer 420, in which a first embodiment of the receiving device 200 (with corresponding signal transmission device 100) is located in the tractor unit 410 and a second embodiment of the receiving device 200' (with corresponding signal transmission device 100') is located in the trailer 420. A fieldbus line 310, for example a line of a CAN trailer system, such as according to the ISO 11992 standard, connects the tractor unit 410 and the trailer 420. The fieldbus line 310 is differentially configured and has a CAN high fiber 313 and a CAN low fiber 315. The receiving devices 200 and 200' are configured to exchange first signals 10 and second signals 20 via the fieldbus line 310. The second signals 20 can only be exchanged via one of the two fibers 313, 315.In exemplary embodiments, the two receiving devices 200, 200' can be configured to exchange second signals 20 via a fiber 313, e.g. CAN-High, of the differential fieldbus line 313 when the other fiber 315 of the differential fieldbus line 310 fails (e.g. is damaged or interrupted).

[0081] Fig. 6 illustrates an embodiment of a truck 400 with a tractor unit 410 and a trailer 420, in which a first embodiment of the receiving device 200 (with corresponding signal transmission device 100) is located in the tractor unit 410 and a second embodiment of the receiving device 200' (with corresponding signal transmission device 100') is located in the trailer 420. The first receiving device 200 includes a warning lamp. A signal transmission line 310 for the warning lamp exists between the tractor unit 410 and the trailer 420. The signal transmission line 310 does not necessarily have to be a fieldbus line. The second receiving device 200' is configured to send a warning signal based on the first signals 10 to the first receiving device 200 via the signal transmission line 310.The second subscriber device 200' is also trained to transmit further information based on the second signals 20 via the signal line 310, and the first subscriber device 200 is trained to receive both the first signals 10 and the second signals 20.

[0082] Fig. 7 shows a step of an embodiment of the presented method for exchanging signals 10, 20 in a digital data communication system 300 in a vehicle 400. The data communication system 300 comprises a signal transmission line 310 and participating devices configured to exchange first signals 10 with a first transmission rate and a first amplitude over the signal transmission line 310. The vehicle 400 comprises a subscriber device 200, which includes a signal transmission device 100 configured to exchange second signals 20 with a second transmission rate and a second amplitude to or from the subscriber device 200 over the signal transmission line 310. The subscriber device 200 can be a participating device of the data communication system 300.The method particularly comprises exchanging S110 second signals 20 to or from the subscriber device 200 via the signal transmission line 310, wherein the second transmission rate is higher than the first transmission rate, and / or wherein the second amplitude is smaller than the first amplitude. Fig. 8 shows a further embodiment of the method. The data communication system 300 comprises a further signal transmission path to which the subscriber device 200 is connected, and the subscriber device 200 is configured to exchange information based on further signals via the further signal transmission line in normal operation. The method first comprises exchanging S120 the further signals via the further signal transmission path. The method further comprises detecting S130 a failure, in particular of the further signal transmission path.If it is determined that the further signal transmission path has failed, the procedure includes triggering S140 of the exchange S110 of second signals via the signal transmission path 310.

[0083] The features of the invention disclosed in the description, claims and figures may be essential for the realization of the invention, either individually or in any combination.

[0084] REFERENCE MARK LIST

[0085] 10 first signals

[0086] 20 second signals

[0087] 30 additional signals, 100 signal transmission devices

[0088] 200 participant devices

[0089] 300 Data communication system

[0090] 310 Signal transmission line

[0091] 313 first fiber 315 second fiber

[0092] 400 vehicles

[0093] 410 tractor unit

[0094] 420 trailers

[0095] S110, S120, S130, S140 Steps of a procedure

Claims

PATENT CLAIMS 1. Signal transmission device (100) for a subscriber device (200) for a digital data communication system (300) in a vehicle (400), wherein the data communication system (300) comprises a signal transmission line (310) and is configured to exchange first signals (10) with a first transmission rate and a first amplitude via the signal transmission line (310), characterized in that the signal transmission device (100) is configured to exchange second signals (20) with a second transmission rate and a second amplitude to or from the subscriber device (200) via the signal transmission line (310), wherein - the second transmission rate is higher than the first transmission rate, and / or - the second amplitude is smaller than the first amplitude.

2. The signal transmission device (100) according to claim 1, wherein the data communication system (300) is one of the following: - a Controller Area Network, CAN, - a Local Interconnect Network, LIN, - another fieldbus.

3. The signal transmission device (100) according to one of the preceding claims, wherein the signal transmission line (310) is one of the following: - a sensor signal line and / or - a monitoring signal line.

4. The signal transmission device (100) according to one of the preceding claims, wherein the signal transmission device (100) is configured to exchange the second signals (20) together with the first signals (10).

5. A subscriber device (200) for a digital data communication system (300) in a vehicle (400), wherein the data communication system (300) comprises a signal transmission line (310) and is configured to exchange first signals (10) with a first transmission rate and a first amplitude via the signal transmission line (310), characterized in that the subscriber device (200) comprises a signal transmission device (100) according to one of the preceding claims.

6. The subscriber device (200) according to claim 5, wherein the subscriber device (200) is one of the following: - a control unit, - a sensor, - a warning device.

7. The subscriber device (200) according to one of claims 5 to 6, wherein the subscriber device (200) is configured to exchange first information based on the first signals (10) and second information based on the second signals (20) via the signal transmission line 310.

8. The subscriber device (200) according to one of claims 5 to 7, wherein the data communication system (300) comprises a further signal transmission path to which the subscriber device (200) is connected, and wherein the subscriber device (200) is configured to exchange information optionally based on further signals via the further signal transmission path or based on the second signals (20) via the signal transmission line.

9. A digital data communication system (300) in a vehicle (400) with tractor (410) and trailer (420), the data communication system (300) comprising: a signal transmission line (310) connecting the tractor (410) and the trailer (420); and a subscriber device (200) according to any one of claims 5 to 8, which is connected to the signal transmission line (310).

10. Method for exchanging signals (10, 20, 30) in a digital data communication system (300) in a vehicle (400), wherein the data communication system (300) comprises a signal transmission line (310) and is configured to exchange first signals (10) with a first transmission rate and a first amplitude via the signal transmission line (310), and wherein the vehicle (400) comprises a subscriber device (200) with a signal transmission device (100) according to any one of claims 1 to 4, characterized by: Exchange (S110) of second signals (20) to or from the subscriber device (200) with a second transmission rate and a second amplitude over the signal transmission line (310), wherein - the second transmission rate is higher than the first transmission rate and / or - the second amplitude is smaller than the first amplitude.

11. Method according to claim 10, wherein the data communication system (300) comprises a further signal transmission path to which the subscriber device (200) is connected, and wherein the subscriber device (200) is configured to exchange information optionally based on further signals via the further signal transmission path or based on the second signals (20) via the signal transmission line, and wherein the method further comprises: Exchange (S120) the further signals via the further signal transmission path; Detecting (S130) a failure; and Triggering (S140), based on the detection (S130) of the failure, the exchange (S110) of second signals (20) via the signal transmission line (310).

12. A computer program product with software code stored thereon, which, when the software code is executed by a signal processing machine, is designed to perform a method according to claim 10 or claim 11.

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