Method and device for determining a type of data bus used for transmitting signals between devices in a vehicle

Abstract

The invention relates to a method for determining the type of data bus used for transmitting signals between devices in a vehicle, said method comprising the following steps: a) receiving (21) a signal transmitted on said data bus; b) extracting (22) a first identifier from said received signal; c) if said first identifier corresponds to a second stored identifier (23), then the data bus type is determined (24) as a data bus of a first type; otherwise, steps a), b), and c) are iterated until a stopping condition is met (25); if the stopping condition is met (25), the data bus type is determined (26) as a data bus of a second type belonging to a set of at least one data bus type. Figure for the abstract: Figure 3

Description

Title of the invention: Method and device for determining a type of data bus used for transmitting signals between peripherals in a vehicle. Technical field

[0001] The invention relates to methods and devices for determining the type of data bus of a vehicle, particularly an automobile. The invention also relates more particularly to a method and device for adapting a peripheral device connected to a vehicle's data bus. Technological background

[0002] Contemporary vehicles incorporate a number of peripherals integrating computers, each ensuring one or more functions, such as, for example, the management of driving assistance, traction control, electronic brake distribution, the control of actuators to ensure the optimal operation of a combustion engine, or the management of a human-machine interface (HMI).

[0003] These computers are connected to each other via a multiplexed serial data bus of the CAN type (from the English "Controller Area Network" or in French "Réseau de contrôlers"). CAN type data buses exist in different versions, such as the CAN LS bus (from English "Low Speed", in French "Far Speed", the maximum rate being approximately 125Kbit / s), the CAN HS bus (from English "High Speed", in French "High Speed", the maximum rate being approximately 1Mbit / s), the CAN FD bus (from English "Flexible Data-Rate", in French "Flexible Data Rate").

[0004] The encoding of the signals passing through it is therefore different depending on the version of the CAN bus. Thus, a device incorporating a computer developed to be installed on a certain version of the CAN bus cannot be installed on a second version of the CAN bus, as the computers are not compatible with several versions of the CAN bus.

[0005] The data bus and control units together form the vehicle's embedded system. These control units are also called ECUs (Electronic Control Units). These control units contain software that is executed to perform the functions for which they are responsible.

[0006] A computer is installed in a specific peripheral device, depending on the type of data bus used for transmitting signals between peripherals of a vehicle. Therefore, such a computer is not compatible with all data buses used in multiple vehicles.

[0007] During the factory configuration of the vehicle, it is then necessary to know the different computers that can equip a vehicle and their compatibilities with the different versions of data bus installed in the vehicle in order to be able to configure these different computers. Summary of the invention

[0008] An object of the invention is to solve at least one of the problems of the prior art, for example to determine the type of a data bus used for the transmission of signals between peripherals in a vehicle.

[0009] According to a first aspect, the invention relates to a method for determining a type of data bus used for the transmission of signals between peripherals in a vehicle, the method being implemented by at least one processor embedded in the vehicle, the method comprising the following steps: a) receiving a signal transmitted on the data bus; b) extraction of a first identifier from the received signal; c) if the first identifier corresponds to a second stored identifier, then the data bus type is determined to be a data bus of a first type; otherwise steps a), b) and c) are iterated until a stopping condition is met; if the stopping condition is met, the data bus type is determined to be a data bus of a second type belonging to a set of at least one data bus type.

[0010] The method allows the device implementing it to determine the type of data bus to which it is connected. The device thus adapts its communication interface to the data bus to which it is connected and can then communicate with other peripherals connected to that same data bus. The configuration or update, particularly software updates, of this device at the factory or in an after-sales service is therefore facilitated compared to the configuration of a device that does not implement this method.

[0011] According to one variant of the method, a stopping condition is checked when a predetermined number of signals is received.

[0012] According to another variant of the method, a stopping condition is checked when a time interval has elapsed since the reception of a first signal.

[0013] These stopping conditions thus prevent the process from being followed indefinitely.

[0014] According to a variant of the method, the first and second identifiers correspond to an address of a device.

[0015] According to a variant of the process, the first identifier is coded on 11 bits.

[0016] According to one variant of the method the data bus is a serial data bus.

[0017] According to one variant of the method the data bus is a CAN data bus.

[0018] According to a second aspect, the invention relates to a device configured to determine a type of a vehicle data bus, the device comprising a memory associated with at least one processor configured for the implementation of the steps of the process according to the first aspect of the invention.

[0019] According to a third aspect, the invention relates to a data bus comprising the device as described above according to the second aspect of the invention and one or more computers.

[0020] According to a fourth aspect, the invention relates to a vehicle, for example of the automobile type, comprising a device as described above according to the second aspect of the invention or a data bus as described above according to the third aspect of the invention.

[0021] According to a fifth aspect, the invention relates to a computer program which includes instructions adapted for carrying out the steps of the process according to the first aspect of the invention, in particular when the computer program is executed by at least one processor.

[0022] Such a computer program may use any programming language, and be in the form of source code, object code, or an intermediate code between source code and object code, such as in a partially compiled form, or in any other desirable form.

[0023] According to a sixth aspect, the invention relates to a computer-readable recording medium on which is recorded a computer program comprising instructions for carrying out the steps of the process according to the first aspect of the invention.

[0024] On the one hand, the recording medium can be any entity or device capable of storing the program. For example, the medium can include a storage means, such as a ROM, a CD-ROM or a microelectronic circuit-type ROM, or a magnetic recording means or a hard disk drive.

[0025] On the other hand, this recording medium can also be a transmissible medium such as an electrical or optical signal, such a signal being able to be transmitted via an electrical or optical cable, by conventional or radio frequency, by self-directing laser beam, or by other means. The computer program according to the invention can, in particular, be downloaded onto an Internet-type network.

[0026] Alternatively, the recording medium may be an integrated circuit in which the computer program is incorporated, the integrated circuit being adapted to execute or to be used in the execution of the process in question. Brief description of the figures

[0027] Other features and advantages of the invention will become apparent from the description of the non-limiting embodiments of the invention below, with reference to the attached Figures 1 to 4, in which:

[0028] [Fig-1] schematically illustrates a vehicle data bus, according to a a particular and non-limiting example of a realization of the invention;

[0029] [Fig.2] schematically illustrates a frame of a signal transmitted on the data bus of [Fig.1], according to a particular and non-limiting embodiment of the invention;

[0030] [Fig.3] illustrates a flowchart of the different steps of a process for determining a type of data bus of the [Fig.1], according to a particular and non-limiting example of the invention;

[0031] [Fig.4] schematically illustrates a device configured to determine a type of data bus of the [Fig.1], according to a particular and non-limiting embodiment of the invention; Description of the implementation methods

[0032] A method and device for determining a type of data bus will now be described in what follows with joint reference to Figures 1 to 4. The same elements are identified with the same reference signs throughout the description that follows.

[0033] According to a particular and non-limiting embodiment of the invention, a signal transmitted on a serial data bus, for example of the CAN LS, CAN HS, or CAN FD type of a vehicle, is received by a device connected to this data bus, for example, a computer in an embedded vehicle system connected to other computers in the embedded system via the data bus. The device extracts a first identifier from the received signal. The first identifier identifies a message carried by the first signal. The first identifier is, for example, coded on 11 bits. The device compares the first identifier to a second identifier stored in the device's memory. The second identifier advantageously characterizes a first type of data bus. The result of the comparison thus allows the device to detect whether the data bus is of the first type of data bus.

[0034] Such a method has the advantage of being simple to implement, requiring only the storage in memory of an identifier characteristic of an identifier transmitted on the first type of data bus. Thus, no learning phase is necessary to implement the method. The computing resources and memory footprint required to implement this method are low. The hardware architecture of a standard computer in an embedded vehicle system is adapted to such an implementation.

[0035] Such a method is for example suitable for determining a type of serial data bus for example of type CAN HS, CAN LS or CAN FD.

[0036] The device then adapts its communication interface to the type of data bus determined and to which it is connected.

[0037] Fig. 1 schematically illustrates a data bus 100 of a vehicle, according to a first particular and non-limiting embodiment of the invention.

[0038] The data bus 100 advantageously corresponds to a multiplexed type data bus linking several computers 11, 12 and 13. A device 10 configured to determine the type of data bus 100 is also linked to the computers 11 to 13 via the data bus 100. Such a device corresponds, for example, to a device configured to receive and process data and is, for example, hosted in a computer in the form of a software module.

[0039] The assembly formed by the data bus 100, the control units 11 to 13, and the device 10 constitutes all or part of an embedded vehicle system, for example, a motor vehicle. The number of control units 11 to 13 is not limited to 3, however, and can extend to any number, for example, 2, 5, 10, 100, or more control units.

[0040] The embedded system also includes, for example, a telematic control unit, called a TCU (Telematic Control Unit), connected in communication with the computers 11 to 13 via the data bus 100. The TCU is connected to one or more antennas of the vehicle for data communication between the vehicle and one or more remote devices, for example via a wireless link based on a cellular network of the LTE (Long-Term Evolution) type, LTE-Advanced (also called 4G or 5G network).

[0041] The data bus is a serial bus, for example, of the CAN LS type as defined in ISO 11898-2, of the CAN HS type as defined in ISO 11898-3, or of the CAN FD type as defined in ISO 11898-1. The data bus 100 advantageously implements time-division multiplexing, allowing the computers 11 to 13 to transmit signals (also called signal frames) in turn. The transmitted signals can be of several types depending on the data they carry, each type of signal being identified by a specific identifier. As will be described in more detail with reference to [Fig. 2], the signals transmitted on the data bus 100 are identified by an identifier whose value is known, this value being, for example, encoded on a specific number of bits, for example, 11 bits.

[0042] The signals, for example, exhibit an event-driven nature and are therefore of a specific type identified by a specific and unique identifier. The signals are said to be event-driven in that they are transmitted when an event is detected at the level of a control unit, for example, control unit 11, or of a sensor associated with a control unit, for example. The event-driven signals are transmitted at irregular intervals that depend on the occurrence of the events to be signaled. For example, two consecutive event-driven signals may be transmitted with a time interval of 30 ms, and the next two consecutive event-driven signals may be transmitted on the data bus 100 with a time interval between these signals of 10 minutes. An event corresponds, for example, to an alert, for example, associated with exceeding a threshold (motor shaft rotation speed exceeding a threshold, motor temperature exceeding a threshold, etc.).

[0043] According to another example, the signals exhibit a periodic character. These periodic signals are of a specific type identified by a specific and unique identifier. The signals are said to be periodic in that they are transmitted at regular intervals (a period) by a computer, for example every 10, 20, 30 ms.

[0044] According to one embodiment, the data bus 100 corresponds for example to a FlexRay type bus (according to ISO 17458) or Ethernet (according to ISO / IEC 802-3).

[0045] Fig. 2 schematically illustrates a frame 3 of a signal transmitted on the data bus 100 by a computer of the embedded system of a vehicle, according to a particular and non-limiting embodiment of the invention.

[0046] According to the illustrative example in [Fig.2], only a part of the fields of frame 3 of the transmitted signal are described or represented, in particular those relating to the object of the invention.

[0047] Frame 3 of the transmitted signal thus comprises: - a first field 31 corresponding to a start of frame, called SOF (from the English "Start Of Frame"), comprising for example 1 bit; - a second field 32 corresponding for example to an arbitration field, also called an identifier field, and comprising the identifier of the message carried by the transmitted signal on 11 or 29 bits followed by an RTR bit (from the English "Remote Transmission Request"). This field comprises for example 12 or 32 bits; this field advantageously serves as an identifier for the data or types of data carried by the transmitted signal, that is to say in the part called the data field; - the third fields 33 to 36 forming a data field and including in particular a counter and useful data of the message carried by the signal transmitted; these fields 33 to 36 each include, for example, 8 bits; the message counter is, for example, contained in the first of these fields, i.e. field 33, and the useful data in the other fields, i.e. fields 34, 35 and 36; according to another example, the counter is contained in the last of these fields, i.e. field 36; according to a variant, there are more than 4 data fields, for example 8 data fields; - a fourth field 37 corresponding to an end of frame, called EOF (from the English "End Of Frame"), comprising for example 7 bits.

[0048] Frame 3 of the transmitted signal may also include other fields not described or shown in [Fig.3], such as, for example, a command field (for example, 6 bits), a CRC field (Cyclic Redundancy Check) and / or an acknowledgment field.

[0049] Figure [Fig.3] illustrates a flowchart of the different steps of a process for determining a type of data bus 100 of Figure [1], according to a first particular and non-limiting embodiment of the invention.

[0050] Such a method is advantageously implemented by the device 10 connected to the data bus 100. The steps of the method below will be described with reference to the reception and processing of a signal. Of course, the same operations apply to the reception and processing of several signals in the same way as described using a signal as an example.

[0051] In a first step 21, a signal transmitted on the data bus 100 is received by the device 10. The signal (or the frame of the signal) is for example emitted on the data bus by one of the computers 11 to 13. The structure of the signal corresponds to the frame 3 described previously.

[0052] In a second step 22, the device 10 extracts (retrieves or determines) the identifier of the received signal, called the first identifier.

[0053] The first identifier is obtained for example from the arbitration field 32 of the signal.

[0054] According to a variant of step 22, the first identifier corresponds to a binary code.

[0055] According to an example of an embodiment of this variant, the first identifier corresponds to a binary string for example of length equal to 11 bits, each bit of the string taking the value 0 or 1.

[0056] According to another embodiment of this variant, the first identifier corresponds to a string of length equal to 29 bits, each bit of the string taking the value 0 or 1.

[0057] In a third step 23, the first identifier is compared to at least one second identifier stored in memory.

[0058] According to a variant of step 23, the memory is a memory of device 10.

[0059] According to another variant of step 23, the memory is a memory of a device other than device 10 (for example a memory of one of the computers 11 to 13) accessible by device 10, for example via data bus 100.

[0060] According to an example of an embodiment of step 23, at least one second identifier is advantageously stored in a table.

[0061] The at least one second identifier corresponds to an identifier of a signal whose type is known to the device 10, this type of signal circulating specifically on a type of data bus 100.

[0062] According to an example of an embodiment of step 23, the first and second identifiers advantageously correspond to an address of a device present only on a certain type of data bus.

[0063] When the first identifier matches the second identifier, then the data bus 100 is determined in a step 24 as being of a first type of data bus.

[0064] When the result of the comparison indicates that the first identifier does not correspond to any second identifier, a stopping condition is checked (step 25).

[0065] If the stopping condition is not met then the device waits for the reception of a new frame of a signal to repeat steps 21 to 23.

[0066] If the stopping condition is met, the data bus 100 is determined in a step 26 as being of a second type of data bus belonging to a set of at least one type of data bus.

[0067] According to an example embodiment of step 25, a stopping condition is met when a predetermined number of signals is received.

[0068] According to an example embodiment of step 25, a stopping condition is met when a time interval has elapsed since the reception of a first signal.

[0069] Once the type of data bus 100 has been determined, the device adapts, for example, its communication interface to the type of bus determined.

[0070] According to one embodiment, a device is connected to a serial data bus of a vehicle equipped with either a CAN HS bus or a CAN FD bus. The second identifier corresponds to the address of a computer characteristic of a CAN HS bus; its coded address is E9 in hexadecimal code, or 11101001 in binary code. The device determines the type of bus to which it is connected by following the procedure described previously in relation to [Fig. 3]. The first identifier contained in the various frames received by the device via the serial data bus is then compared to the predetermined second identifier.

[0071] If a first identifier from a received frame corresponds to the coded address of a characteristic CAN HS bus computer, then the device determines the type of serial data bus as being of the CAN HS type.

[0072] Conversely, if after a few hundred milliseconds no first identifier from several received frames corresponds to the coded address of a characteristic CAN HS bus computer, then the device determines by elimination the type of serial data bus as being of the CAN FD type.

[0073] The device thus adapts its communication interface to the data bus to which it is connected and can then communicate with other devices connected to the same data bus.

[0074] According to an embodiment of the method, when a stopping condition is met, a new second identifier corresponding to a second type of data bus, or a new table of second identifiers, is defined, and steps 21 to 23 are repeated with these new second identifiers. Thus, a first type of bus is eliminated, and the process allows a second type of data bus to be searched for among a set of data bus types.

[0075] Figure 4 schematically illustrates a device 4 configured to determine a type of a data bus 100, according to a particular and non-limiting embodiment of the invention. Device 4 corresponds, for example, to device 10.

[0076] Device 4 is, for example, configured to implement the steps of the process described opposite [Fig. 3]. The elements of Device 4, individually or in combination, can be integrated into a single integrated circuit, into several integrated circuits, and / or into discrete components. Device 4 can be implemented as electronic circuits or software (or computer) modules, or a combination of electronic circuits and software modules. According to various specific embodiments, Device 4 is coupled in communication with other similar devices or systems, for example, via a communication bus or through dedicated input / output ports.

[0077] The device 4 comprises one (or more) processor(s) 40 configured to execute instructions for carrying out the steps of the process and / or for executing instructions from the software embedded in the device 4. The processor 40 may include integrated memory, an input / output interface, and various circuits known to those skilled in the art. The device 4 further comprises at least one memory 41, for example, volatile and / or non-volatile memory, and / or includes a memory storage device that may include volatile and / or non-volatile memory, such as EEPROM, ROM, PROM, RAM, DRAM, SRAM, flash, magnetic disk, or optical disk.

[0078] The computer code of the embedded software(s), including the instructions to be loaded and executed by the processor, is for example stored on the first memory 4L

[0079] According to a particular embodiment, the device 4 includes a communication interface 43 which allows communication to be established with other devices (such as the computers of the embedded system and connected to the data bus) via a communication channel 430. The communication interface 43 corresponds, for example, to a transmitter configured to transmit and receive information and / or data via the communication channel 430. The communication interface 43 corresponds, for example, to a wired network of the CAN LS, CAN FS or CAN FD type.

[0080] According to a further particular embodiment, the device 4 can provide output signals to one or more external devices, such as a display screen, one or more speakers and / or other peripherals via output interfaces not shown respectively.

[0081] Of course, the invention is not limited to the embodiments described above but extends to a method of determining a type of data bus used for the transmission of signals between peripherals in a vehicle and to the device configured for the implementation of the method.

[0082] The invention also relates to a vehicle, for example a motor vehicle or more generally a land motor vehicle, comprising the device 4 of [Fig.4] or the data bus 100 of [Fig.1].

Claims

Demands

1. A method for determining a type of data bus used for transmitting signals between devices in a vehicle, said method being implemented by at least one processor embedded in said vehicle, said method comprising the following steps: a) receiving (21) a signal transmitted on said data bus (100); b) extracting (22) a first identifier from said received signal; c) if said first identifier corresponds to a second stored identifier (23), then the type of data bus is determined (24) to be a data bus of a first type; otherwise, steps a), b) and c) are iterated until a stopping condition is met (25);if the stopping condition is satisfied (25), the data bus type is determined (26) as being a data bus of a second type belonging to a set of at least one data bus type, a method in which the first and second identifiers correspond to a device address.

2. A method according to claim 1, wherein a stopping condition is verified when a predetermined number of signals is received.

3. A method according to any one of claims 1 to 2, wherein a stopping condition is met when a time interval has elapsed since the reception of a first signal.

4. A method according to any one of claims 1 to 3, wherein said first identifier is coded on 11 bits.

5. A method according to any one of the preceding claims, wherein the data bus is a serial data bus.

6. Method according to claim 5, wherein said data bus (100) is a CAN data bus.

7. Device (4) configured to determine a type of a vehicle data bus (100), said device (4) comprising a memory (41) associated with at least one processor (40) configured to carry out the steps of the method according to any one of claims 1 to 6.

8.

9. Vehicle comprising device (4) according to claim 7. Computer program comprising instructions for carrying out the method according to any one of claims 1 to 6, when such instructions are executed by a processor.

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