Method and device for managing the communication between two electronic control units of a motor vehicle that are connected by means of a wired communication network

Abstract

The invention relates to a method for managing the communication of a first electronic control unit (10) on board a motor vehicle (1) with a second electronic control unit (20) on board the vehicle, which second electronic control unit is connected to the first electronic control unit by means of a wired communication network (30) of the vehicle. The invention also relates to a device (100) for implementing such a method and to a motor vehicle comprising such a device.

Description

Description Title of the invention: Method and device for managing communication between two electronic control units of a motor vehicle connected by means of a wired communication network Technical field of the invention

[0001] The present invention relates to the field of electronic control units for motor vehicles. The invention relates in particular to a method for managing, by a computer device integrated into a first electronic control unit on board a motor vehicle, the communication of the first electronic control unit with a second electronic control unit on board the vehicle and connected to the first electronic control unit by means of a wired communication network of the vehicle. The invention also relates to a device implementing such a method. The invention applies to motor vehicles such as land motor vehicles, in particular cars. State of the prior art

[0002] It is known that modern motor vehicles are equipped with wired communication networks that connect the vehicles' electronic control units, including half-duplex bidirectional communication networks (e.g. CAN, Ethernet). It is also known that when a transmitting communicating entity wishes to transmit data to a receiving communicating entity by means of such communication networks, the transmitting entity must first ensure that the receiving entity is available to receive the transmitted data, otherwise there is a risk of seeing this data lost. However, the known solutions for taking these constraints into account generally require the implementation of wake-up protocols that complicate the operation of the electronic control units, congest the vehicles' communication networks and inevitably slow down the data transmission speed. Summary of the invention

[0003] The invention aims to overcome these drawbacks by providing an alternative solution to enable communication between two electronic control units of a motor vehicle connected by means of a wired communication network in a reliable manner, i.e. which minimizes the risk of data loss, while minimizing the load induced on the electronic control units. In this way, The invention aims to improve the speed of data transmission between two electronic control units of a motor vehicle by means of an on-board half-duplex bidirectional wired communication network and thus contribute to the provision of more efficient and safer motor vehicles.

[0004] To achieve these objectives, the invention relates, according to a first aspect, to a method for managing, by a computer device integrated into a first electronic control unit on board a motor vehicle, the communication of the first electronic control unit with a second electronic control unit on board the vehicle and connected to the first electronic control unit by means of a wired communication network of the vehicle, the method comprising the steps of: i.determining whether a first condition is met, the first condition being met when it is established that a communication frame indicating a waiting state of the second electronic control unit and containing a particular value of a frame counter has been received after a time interval of a duration greater than a transmission period of the second electronic control unit has elapsed since the first reception of a communication frame indicating a waiting state of the second electronic control unit and containing the particular value of a frame counter; ii. determining whether a second condition is met, the second condition being met when it is established that no communication frame has been received during a time interval of a duration greater than said period; iii.determining whether a third condition is met, the third condition being met when it is established that a communication frame indicating a waiting state of the second electronic control unit and containing a first value of a frame counter incremented relative to a second value of a frame counter contained in a previous communication frame has been received before a time interval of a duration greater than said period has elapsed since the first reception of a communication frame indicating a waiting state of the second electronic control unit and containing the second value of a frame counter; iv. establishing that the second electronic control unit is unavailable to receive data if the first or second condition is met; and v. establishing that the second electronic control unit is available to receive data if the third condition is met.

[0005] Alternatively, step iv) may comprise a step of causing the transmitting a communication frame indicating a waiting state of the first electronic control unit and containing a value of an incremented frame counter.

[0006] According to another variant, step v) may comprise a step consisting of causing the transmission of a communication frame containing data awaiting transmission and an incremented frame counter value.

[0007] According to a second aspect, the invention relates to a device for managing the communication of a first electronic control unit on board a motor vehicle with a second electronic control unit on board the vehicle and connected to the first electronic control unit by means of a wired communication network of the vehicle, the device comprising at least one information processing unit, comprising at least one processor, and a data storage medium configured to implement a method as described above.

[0008] According to a third aspect, the invention relates to a computer program comprising program code instructions for executing the steps of a method as described above when said program is executed by at least one processor.

[0009] According to a fourth aspect, the invention relates to a medium usable in a computer on which a program as described above is recorded.

[0010] According to a fifth aspect, the invention relates to a motor vehicle which has a first electronic control unit and a second electronic control unit which each integrate a device as described above. Brief description of the figures

[0011] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which:

[0012] [Fig.l] is a schematic illustration of a motor vehicle according to the invention;

[0013] [Fig.2] is a functional diagram of a device according to the invention;

[0014] [Fig. ] is a flowchart of certain steps of a method according to the invention;

[0015] [Fig.4] illustrates the implementation of the method according to the invention; and

[0016] [Fig.5] illustrates the implementation of the method according to the invention. Detailed description of the invention

[0017] [Fig.l] schematically illustrates a motor vehicle 1 according to the invention. This conventionally comprises a first electronic control unit 10 and a second electronic control unit 20 connected to each other by means of a wired communication network 30, preferably a half-duplex bidirectional network with time division multiplexing (e.g. CAN, Ethernet). Each of these units of electronic control 10, 20 is conventionally configured to transmit two types of communication frames, namely synchronization frames which indicate a waiting state of the electronic control unit (IDLE) and data frames (DATA), and these frames are transmitted periodically with a transmission period previously established for each electronic control unit.Furthermore, each electronic control unit 10, 20 advantageously integrates a device 100 for managing the communication of a first electronic control unit on board a motor vehicle with a second electronic control unit on board the vehicle and connected to the first electronic control unit by means of a wired communication network of the vehicle within the meaning of the present invention, as described below, which implements a method for managing the communication of a first control unit on board a motor vehicle with a second electronic control unit on board the vehicle and connected to the first electronic control unit by means of a wired communication network of the vehicle within the meaning of the present invention, as described below.By means of these means, communication between the first electronic control unit 20 and the second electronic control unit 30 of the vehicle 1 according to the invention is enabled in a reliable manner, i.e. by minimizing the risk of data loss, while reducing the load on the electronic control units 10, 20, minimizing the risk of congestion of the network 30 and improving the speed of data transmission between the first 10 and the second electronic control unit 20.

[0018] A device 100 for managing the communication of a first electronic control unit on board a motor vehicle with a second electronic control unit on board the vehicle and connected to the first electronic control unit by means of a wired communication network of the vehicle according to the invention is illustrated in [Fig. 2]. It is fundamentally a computer device which comprises at least one information processing unit 101, comprising one or more processors, a data storage medium 102, on which is recorded in particular a program which comprises program code instructions for the execution of the steps of the method according to the invention described later, and an input and output interface 103 allowing the reception and transmission of data.

[0019] According to the invention, all the elements described above contribute to each electronic control unit 10, 20 of the vehicle 1 being able to implement a method for managing the communication of a first electronic control unit on board a motor vehicle with a second electronic control unit on board the vehicle and connected to the first unit electronic control by means of a wired communication network of the vehicle within the meaning of the present invention, as described below in connection with Figures 3-5. It will be noted that the steps implemented by the device 100 according to the invention which is integrated into the first electronic control unit 10 are described below. It should however be noted that the same method is also implemented by the device 100 according to the invention which is integrated into the second electronic control unit 20.

[0020] According to a first step 301 of the method according to the invention, the device 100 according to the invention determines whether a first condition is fulfilled, by considering that the first condition is fulfilled when it establishes that a communication frame indicating a waiting state of the second electronic control unit and containing a particular value of a frame counter has been received after a time interval of a duration greater than a transmission period of the second electronic control unit has elapsed since the first reception of a communication frame indicating a waiting state of the second electronic control unit and containing the particular value of a frame counter.

[0021] For example, if we refer to [Fig. 4] which illustrates this first step 301 of the method, on which are indicated communication frames received (RxFrame) and communication frames transmitted (TxFrame) by the first electronic control unit 10, we see that the latter first receives ten communication frames indicating a waiting state from the second electronic control unit 20, in other words synchronization frames, which all contain the same particular value of a frame counter (XX). And it is only the eleventh synchronization frame received which contains a new value of a frame counter (YY) different from the particular value (XX).Furthermore, upon receiving the seventh communication frame, the device 100 according to the invention establishes that the transmission period (T1) of the second electronic control unit 20, which corresponds to the period with which the second electronic control unit 20 is configured to, when it is available to receive data, transmit a synchronization frame containing a value of an incremented frame counter, is exceeded. To do this, the transmission period of the second electronic control unit 20 is known by the device 100 according to the invention integrated into the first electronic control unit 10, for example recorded on its data storage medium 102 at the time of design of the vehicle.Thus, it is precisely upon receiving this seventh synchronization frame containing an unchanged frame counter value that the device 100 according to the invention establishes that a time interval of a duration greater than the transmission period of the second electronic control unit 20 has elapsed and, by. consequently, that the first condition is fulfilled. As will be seen below, it is therefore at this moment that the device 100 according to the invention advantageously establishes that the second electronic control unit 20 switches from an operating state in which it is available to receive transmitted data (ALIVE) to an operating state in which it is unavailable to receive data (OFF).

[0022] According to a second step 302 of the method according to the invention, the device 100 according to the invention determines whether a second condition is met, by considering that the second condition is met when it establishes that no communication frame has been received during a time interval of a duration greater than said period. In other words, the device 100 according to the invention advantageously determines during this second step of the method whether there is a situation in which the second electronic control unit 20 is inactive, and therefore obviously unavailable to receive data.

[0023] According to a third step 303 of the method according to the invention, the device 100 according to the invention determines whether a third condition is met, by considering that the third condition is met when it establishes that a communication frame indicating a waiting state of the second electronic control unit 20 and containing a first value of a frame counter incremented relative to a second value of a frame counter contained in a previous communication frame has been received before a time interval of a duration greater than the transmission period (T1) of the second electronic control unit 20 has elapsed since the first reception of a communication frame indicating a waiting state of the second electronic control unit and containing the second value of a frame counter.

[0024] For example, if we now refer to [Fig. 5] which illustrates this third step 303 of the method, we see that the first electronic control unit 10 first receives five synchronization frames which each comprise the same first value of a frame counter (IDLEn). Then, the sixth synchronization frame received contains a value of a frame counter (IDLEn+1) incremented relative to the value of the frame counter contained in the previous frame, i.e. the fifth synchronization frame. Furthermore, upon reception of the sixth synchronization frame, the device 100 according to the invention establishes that it is received before a time interval of a duration greater than the transmission period (T1) of the second electronic control unit 20 has elapsed since the first reception of a synchronization frame containing the second value of a frame counter (IDLEn).Also, it is upon receiving this sixth synchronization frame containing a value of an incremented frame counter that the device 100 according to the invention establishes that the third condition is fulfilled. As will be seen. below, it is therefore at this moment that the device 100 according to the invention advantageously establishes that the second electronic control unit 20 switches from an operating state in which it is unavailable to receive transmitted data (OFF) to an operating state in which it is available to receive data (ALIVE).

[0025] According to a fourth step 304 of the method according to the invention, the device 100 according to the invention establishes that the second electronic control unit 20 is unavailable to receive data if the first or second condition is met and, according to a fifth step 305 of the method according to the invention, it establishes that the second electronic control unit is available to receive data if the third condition is met.

[0026] For example, if we refer again to [Fig. 4], the lower part shows the availability of the second electronic control unit 20 to receive data as established by the device 100 according to the invention and, below, the operating state of the first electronic control unit 10 from the point of view of its ability to transmit data. Indeed, from the point of view of data transmission, an electronic control unit according to the invention switches between an operating state in which it transmits data (ACTIVE) by means of data frames (DATAx) and a waiting state (IDLE) in which it transmits synchronization frames (IDELn). As has been seen, it is upon reception of the seventh synchronization frame that the device 100 according to the invention establishes that the first condition is fulfilled.It is therefore at this moment that it establishes that the second electronic control unit 20 is unavailable to receive data (OFF). Consequently, the device 100 according to the invention then causes the transmission of synchronization frames containing incremented frame counter values ​​(IDLEm; IDLEm+1).

[0027] According to a fifth step 305 of the method according to the invention, the device 100 according to the invention establishes that the second electronic control unit 20 is available to receive data if the third condition is met.

[0028] For example, if we refer again to [Fig. 5], we have seen that it is upon reception of the sixth synchronization frame that the device 100 according to the invention establishes that the third condition is met. It is therefore at this moment that it establishes that the second electronic control unit 20 is available to receive data (ALIVE). Then, as soon as the device 100 establishes that data is awaiting transmission (TxFIFO <> empty), it causes the transmission of a communication frame containing data awaiting transmission and a value of an incremented frame counter (DATAx).

[0029] Thus, thanks to the method and the device according to the invention described above, a solution is provided to enable a first electronic control unit of a motor vehicle to determine the availability of a second electronic control unit to receive data transmitted by means of a wired communication network. The invention thus makes it possible to manage communication between two electronic control units of a motor vehicle reliably, i.e. by minimizing the risk of data loss, while minimizing the load induced on the electronic control units. By means of these means, the invention improves the speed of data transmission between two electronic control units of a motor vehicle by means of an on-board half-duplex bidirectional wired communication network and thus contributes to the provision of more efficient and safer motor vehicles.

Claims

Claims

1. Method for managing, by a computer device (100) integrated into a first electronic control unit (10) on board a motor vehicle (1), the communication of the first electronic control unit with a second electronic control unit (20) on board the vehicle and connected to the first electronic control unit by means of a wired communication network (30) of the vehicle, characterized in that the method comprises the steps of: i.determining whether a first condition is met, the first condition being met when it is established that a communication frame indicating a waiting state of the second electronic control unit and containing a particular value of a frame counter has been received after a time interval of a duration greater than a transmission period of the second electronic control unit has elapsed since the first reception of a communication frame indicating a waiting state of the second electronic control unit and containing the particular value of a frame counter; ii. determining whether a second condition is met, the second condition being met when it is established that no communication frame has been received during a time interval of a duration greater than said period; iii.determining whether a third condition is met, the third condition being met when it is established that a communication frame indicating a waiting state of the second electronic control unit and containing a first value of a frame counter incremented relative to a second value of a frame counter contained in a previous communication frame has been received before a time interval of a duration greater than said period has elapsed since the first reception of a communication frame indicating a waiting state of the second electronic control unit and containing the second value of a frame counter; iv. establishing that the second electronic control unit is. unavailable to receive data if the first or second condition is met; and v. establishing that the second electronic control unit is available to receive data if the third condition is met.

2. Method according to claim 1, characterized in that step iv) comprises a step of causing the transmission of a communication frame indicating a waiting state of the first electronic control unit and containing a value of an incremented frame counter.

3. Method according to one of the preceding claims, characterized in that step v) comprises a step consisting of causing the transmission of a communication frame containing data awaiting transmission and an incremented value of an frame counter.

4. Device (100) for managing the communication of a first electronic control unit on board a motor vehicle with a second electronic control unit on board the vehicle and connected to the first electronic control unit by means of a wired communication network of the vehicle, characterized in that the device comprises at least one information processing unit (101), comprising at least one processor, and a data storage medium (102) configured to implement a method according to any one of the preceding claims.

5. A computer program comprising program code instructions for executing the steps of a method according to any one of claims 1 to 3 when said program is executed by at least one processor.

6. Support usable in a computer, characterized in that a program according to claim 5 is recorded therein.

7. Motor vehicle, characterized in that it has a first electronic control unit and a second electronic control unit which each integrate a device according to claim 4.

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