Sensor network with a fault diagnosis device, method for fault diagnosis in a sensor network, computer-readable storage medium

Abstract

One aspect of the invention relates to a sensor network with a fault diagnosis device for a vehicle, wherein the sensor network has a daisy-chain topology, and the fault diagnosis device is configured to perform an initialization of a plurality of environmental sensors of the sensor network, by means of which a mounting position is assigned to each environmental sensor of the sensor network. Furthermore, the fault diagnosis device is configured to receive sensor signals from the environmental sensors, wherein the sensor signals can each be assigned to one of the environmental sensors, and to detect the absence of one of the sensor signals. In addition, the fault diagnosis device is configured to output a fault signal depending on the absence of one of the sensor signals, wherein the fault signal describes the position of a line break in the sensor network.

Description

[0001] The present invention relates to a sensor network with a fault diagnostic device for a vehicle and a method for fault diagnosis in a sensor network of a vehicle. Finally, the present invention relates to a computer-readable storage medium.

[0002] The number of sensors and other electronic components in modern vehicles is constantly increasing. As a result, the complexity and material usage in the production of the cable harnesses required for cabling and networking are increasing significantly. As a result, the number of potential errors during assembly is increasing, and production costs are also rising – also due to rising raw material prices. Vehicle manufacturers are therefore constantly striving to simplify the cabling of modern vehicles and reduce costs and weight. To achieve this, the network topology, i.e., the structure of the cabling, can be varied. However, certain network topologies can make troubleshooting more difficult in cases of doubt.

[0003] Document DE 10 2017 103 117 A1 discloses a method for operating a sensor arrangement based on the DSI protocol to operate active sensor units with a transmitter and receiver. For communication between the processing unit and the active sensor unit, the use of three subphases is proposed: a CRM phase for bidirectional communication between the processing unit and the active sensor unit, a power phase for energy transfer from the processing unit to the active sensor units, and a PDCM phase for unidirectional data transmission from the active sensor unit to the processing unit.Furthermore, the document discloses granting at least one active sensor unit the release for a supplementary time slot in the PDCM phase during a CRM phase, so that this active sensor unit has two time slots available for communication with the processing unit in the PDCM phase.

[0004] The object of the present invention is to provide a solution for improving fault diagnosis in a sensor network of a vehicle. In particular, the object of the present invention is to improve fault diagnosis in a sensor network with a daisy-chain topology.

[0005] This object is achieved by the features of the independent claims. Further advantageous embodiments of the invention are specified in the dependent claims.

[0006] One aspect of the invention relates to a sensor network with a fault diagnostic device for a vehicle, wherein the sensor network has a daisy-chain topology, wherein the fault diagnostic device is configured to initialize a plurality of environmental sensors of the sensor network, by means of which initialization an installation position is assigned to each environmental sensor of the sensor network. Furthermore, the fault diagnostic device is configured to receive sensor signals from the environmental sensors, wherein the sensor signals are each assignable to one of the environmental sensors, and to detect the absence of one of the sensor signals. Furthermore, the fault diagnostic device is configured to output an error signal depending on the absence of one of the sensor signals, wherein the error signal describes a position of a line interruption in the sensor network.

[0007] The fault diagnostic device can be implemented, for example, by means of a computing device. In particular, the fault diagnostic device can be formed by at least one electronic control unit of the vehicle, which comprises one or more programmable processors.

[0008] The sensor network can consist of a plurality of environmental sensors wired to the fault diagnosis device. These can be radar, lidar, and / or ultrasonic sensors, in particular. Cameras can also be used as environmental sensors. Such environmental sensors are now installed in large numbers in vehicles. Of particular note are so-called parking distance control sensors (PDC sensors) and short-range radars (SRR). Vehicles typically have four to twelve such sensors, although more sensors are certainly conceivable in the future. Depending on the assistance function for which the sensors are used, they can form a sensor network as described above. For example, the PDC sensors used as part of a parking aid can form a sensor network.

[0009] Until now, the environment sensors were often individually wired to a vehicle's control unit. This can simplify fault diagnosis, but results in countless additional meters of wiring harness, increasing complexity, and consequently leading to increased costs and weight.

[0010] The sensor network according to the invention with the fault diagnostic device therefore has a so-called daisy chain topology. A daisy chain refers to a number of hardware components connected in series. In the present case, the environmental sensors of the sensor network are connected in series. Consequently, it is possible to connect only one of the plurality of environmental sensors to a central control unit—which can also form the fault diagnostic device. For example, the fault diagnostic device or the central control unit is wired to a first environmental sensor with two cables. The first environmental sensor can then, in turn, be wired to a second environmental sensor with two cables, and so on.

[0011] If identical sensors are used in the sensor network described above, the sensor network must be initially trained after installation in order to assign each environmental sensor a unique installation position and store this information persistently. Therefore, the fault diagnostic device is configured to initialize the majority of the environmental sensors in the sensor network. Only then can a possible system diagnosis / fault diagnosis at a later time access the information about which environmental sensor was mounted at which installation position.

[0012] The fault diagnostic device is therefore configured to receive the corresponding sensor signals from the environmental sensors. For example, the environmental sensors can be queried sequentially by the fault diagnostic device, whereupon they either forward a corresponding query or return the corresponding sensor signal to transmit the installation position. Depending on when the respective environmental sensor transmits the corresponding sensor signals, the fault diagnostic device can determine its installation position.

[0013] Furthermore, the fault diagnostic device is configured to detect the absence of one of the sensor signals. If, for example, a corresponding sensor signal cannot be detected by an environmental sensor, this can be detected. In the event of a line break, the daisy-chain topology of the sensor network means that none of the subsequent environmental sensors can subsequently receive the corresponding sensor signal.

[0014] Finally, by outputting the error signal depending on the absence of one of the sensor signals, an error memory entry can be generated that describes the position of the cable interruption in the sensor network in detail. In the event of wiring harness errors or incorrectly contacted environmental sensors during assembly or repair, error diagnosis can be improved. This can reduce the disadvantages of a daisy-chain topology of a vehicle's sensor network. In particular, error diagnosis in such a sensor network can be improved. The sensor network according to the invention with the error diagnosis device thus allows the reduction of wiring harness complexity, contributes to increased sustainability by reducing material usage, and simultaneously avoids associated disadvantages in error diagnosis.

[0015] Another embodiment of the sensor network with the fault diagnostic device provides for a conductor pair of a cable connection between each two of the environmental sensors to be twisted. Furthermore, the cable connection between an environmental sensor and a control unit (ECU) can also be twisted. Conventional topologies for sensor networks in vehicles often provide more than two cables for communication between the environmental sensor and the control unit, as well as for supplying power to the environmental sensor. The daisy-chain topology allows the use of only two cables. By twisting the conductor pairs of a cable connection between the individual sensors, the cables can be further protected or shielded from interference and signals.

[0016] Alternatively or additionally, a further embodiment of the sensor network with the fault diagnostic device provides that the environmental sensors have capacitors for supplying power during a transmission phase, wherein the sensor signals are transmitted to the fault diagnostic device during the transmission phase. Due to the use of only two lines or one pair of conductors per environmental sensor, it may not be possible to continuously supply power to the environmental sensor, as certain time periods may be reserved for communication. It may therefore be advantageous for the sensor network if the environmental sensors have capacitors for supplying power during these time periods.

[0017] Furthermore, it can be advantageous if the environmental sensors in the sensor network are of the same design. The use of identical sensors in particular can require initialization and teaching of the installation position. Furthermore, a sensor network as described above is particularly suitable for identical environmental sensors, as fault diagnosis is particularly challenging in these cases. By using the appropriate fault diagnosis device, additional advantages can be generated for a sensor network with a daisy-chain topology.

[0018] A further embodiment of the sensor network with the fault diagnostic device provides that the environmental sensors are ultrasonic sensors, which have a frequency range of 30 kHz to 80 kHz. Ultrasonic sensors are among the most cost-effective environmental sensors in the automotive sector. Almost every vehicle today has a multitude of such sensors, in particular to assist the driver during parking and maneuvering. Simplifying the cabling can thus result in a significant reduction in the complexity of the wiring harness, particularly with ultrasonic sensors, and a corresponding reduction in costs; however, this requires improved fault diagnostics. Improved fault diagnostics for electrical wiring harness errors or incorrectly contacted environmental sensors during assembly or repair can be achieved with the inventive fault diagnostic device of the sensor network.

[0019] A further aspect of the invention relates to a method for fault diagnosis in a sensor network of a vehicle, wherein the sensor network has a daisy-chain topology. The method comprises initializing a plurality of environmental sensors of the sensor network, wherein an installation position is assigned to each environmental sensor of the sensor network by means of the initialization. Furthermore, the method comprises receiving sensor signals from the environmental sensors, wherein the respective sensor signal is assigned to one of the environmental sensors, and detecting the absence of one of the sensor signals. Finally, the method comprises outputting an error signal depending on the absence of one of the sensor signals, wherein the error signal describes a position of a line interruption in the sensor network.

[0020] The method can be carried out, for example, using a fault diagnostic device of a sensor network or a computing device. The fault diagnostic device or computing device can be embodied, for example, as at least one electronic control unit of the vehicle, which comprises one or more programmable processors. Furthermore, the computing device or fault diagnostic device can have a computer-readable storage medium on which a computer program is stored. In order to carry out corresponding method steps, such as detecting the absence of one of the sensor signals, the computer program can be executed on the computing device or the fault diagnostic device.

[0021] A further aspect of the invention relates to a computer-readable storage medium comprising instructions which, when executed by a computing device or by a fault diagnosis device of a sensor network, cause the computing device or the fault diagnosis device to execute a method for fault diagnosis in a sensor network of a vehicle and the advantageous embodiments thereof.

[0022] A further aspect of the invention relates to a computer program comprising instructions which, when the program is executed by a computing device or a fault diagnosis device of a sensor network, cause the fault diagnosis device or the computing device to execute a method for fault diagnosis in a sensor network of a vehicle and the advantageous embodiments thereof.

[0023] An assistance system for a vehicle according to the invention comprises a sensor network according to the invention with a fault diagnostic device and a computer-readable storage medium according to the invention. In particular, the assistance system can be a parking aid with Park Distance Control (PDC) sensors.

[0024] Finally, the invention also relates to a vehicle comprising an assistance system according to the invention. The vehicle can be designed, in particular, as a passenger car.

[0025] The preferred embodiments presented with reference to the sensor network according to the invention with a fault diagnostic device and their advantages apply accordingly to the method according to the invention and to the computer-readable storage medium according to the invention. Furthermore, the preferred embodiments presented with reference to the sensor network according to the invention with a fault diagnostic device and their advantages also apply to the computer program according to the invention, to the assistance system according to the invention, and to the vehicle according to the invention.

[0026] Further features of the invention emerge from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.

[0027] The invention will now be explained in more detail using preferred embodiments and with reference to the accompanying drawings. Fig. 1 a schematic representation of a method for fault diagnosis in a sensor network having a daisy-chain topology, and Fig. 2 Sensor network with a fault diagnostic device for a vehicle.

[0028] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0029] Fig. 1 shows a schematic representation of a method S for fault diagnosis in a sensor network 2 of a vehicle 1 having a daisy-chain topology. Fig. Figure 2 shows an embodiment of the sensor network 2 with a fault diagnostic device 5 in the vehicle 1. The cabling of the plurality of environmental sensors 4 can each comprise a conductor pair 6. One of the environmental sensors 4 can be connected to the fault diagnostic device 5. Two of the environmental sensors 4 can each be connected to each other via a conductor pair 6. Such a sensor network 2 has a so-called daisy-chain topology.

[0030] The conductor pairs 6 can be twisted to achieve improved shielding. The environmental sensors 4 can be, for example, PDC sensors or ultrasonic sensors. The environmental sensors 4 can also be of identical construction. During assembly and / or repair, wiring harness errors or incorrectly connected environmental sensors 4 may occur.

[0031] For example, if there is a line break 3 between the Fig. 2, the subsequent environmental sensors 4 cannot be reached or no signal can be received from them.

[0032] In order to improve error diagnosis in such a case, the error diagnostic device 5 can teach the environmental sensors 4 of the sensor network 2 during an initialization S1. This is particularly necessary with identical environmental sensors 4 in order to assign an installation position to each environmental sensor 4. While receiving S2 the sensor signals from the environmental sensors 4, the error diagnostic device 5 can assign each sensor signal to a specific environmental sensor 4. The error diagnostic device 5 can detect an absence S3 of one of the sensor signals and then, depending on the absence S3 of one of the sensor signals, cause an output S4 of an error signal. The error signal can describe the position of the line interruption 3 of the sensor network 2 in detail. This can improve error diagnosis overall in sensor networks 2 with a daisy-chain topology. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2017 103 117 A1

[0003]

Claims

[1] Sensor network (2) with a fault diagnosis device (5) for a vehicle (1), wherein the sensor network (2) has a daisy-chain topology, wherein the fault diagnosis device (5) is configured to: - to carry out an initialisation (S1) of a plurality of environmental sensors (4) of the sensor network (2), by means of which an installation position is assigned to each environmental sensor (4) of the sensor network (2), - to receive (S2) sensor signals from the environmental sensors (4), wherein the sensor signals can each be assigned to one of the environmental sensors (4), - to detect the absence of one of the sensor signals (S3), and - to output an error signal depending on the absence of one of the sensor signals (S4), wherein the error signal describes a position of a line interruption (3) of the sensor network (2). [2] Sensor network (2) according to claim 1, characterized bythat a conductor pair (6) of a line connection of two of the environmental sensors (4) is twisted. [3] Sensor network (2) according to claim 1 or 2, characterized by that the environmental sensors (4) have capacitors for supplying energy during a transmission phase, wherein the sensor signals are transmitted to the fault diagnosis device (5) during the transmission phase. [4] Sensor network (2) according to one of the preceding claims, characterized by that the environmental sensors (4) of the sensor network (4) are identical in construction. [5] Sensor network (2) according to one of the preceding claims, characterized by that the environmental sensors (4) are ultrasonic sensors which have a frequency range of 30 kHz to 80 kHz. [6] Method (S) for fault diagnosis (5) in a sensor network (2) of a vehicle (1), wherein the sensor network (2) has a daisy-chain topology, comprising the steps: - Initializing (S1) a plurality of environmental sensors (4) of the sensor network (2), wherein by means of the initialization an installation position is assigned to each environmental sensor (4) of the sensor network (2), - receiving (S2) sensor signals from the environmental sensors (4), wherein the respective sensor signal is assigned to one of the environmental sensors (4), - Detection of a lack (S3) of one of the sensor signals, - Outputting (S4) an error signal depending on the absence (S3) of one of the sensor signals, wherein the error signal describes a position of a line interruption (3) of the sensor network (2). [7] A computer-readable storage medium comprising instructions which, when executed by a computing device, cause the computing device to carry out a method according to claim 6.

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