JP2021013135A - Electronic control device for vehicle - Google Patents

Abstract

To provide an electronic control device for vehicles, capable of performing a diagnosis on communication by an own station alone and identifying the abnormal part of the own station in more detail than before.SOLUTION: An embodiment of the present invention relates to an electronic control device 1A for vehicles which controls the operation of a controlled object using a communication network for vehicles. The electronic control device 1A for vehicles includes: a transceiver 4 which transmits/receives data signals to/from a transmission line 9 constituting the communication network for vehicles; a microcomputer 2 which transmits/receives data signals to/from the transceiver 4; and a cut-off circuit 5 which is provided between the transceiver 4 and the transmission line 9, and which switches to a communication cut-off state cutting off communication with the transmission line 9 or a communication connection state enabling communication with the transmission line 9. The microcomputer 2 switches the cut-off circuit 5 to the communication cut-off state to diagnose the transceiver 4.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electronic control device for a vehicle, and more particularly to a technique for diagnosing an electronic control device for a vehicle.

In recent years, vehicles such as automobiles are equipped with a large number of electronic control units (ECUs) for performing engine control, brake control, transmission control, door control, air conditioner control, and the like. Each ECU is equipped with a microcomputer with a built-in communication circuit (hereinafter abbreviated as "microcomputer") and a transceiver (driver / receiver), and constitutes a vehicle LAN together with a transmission line installed in the vehicle. .. Further, in vehicles such as automobiles, a bus-type communication network system called CAN (Controller Area Network) is adopted.

Further, when a malfunction occurs in the ECU and normal communication cannot be performed, the communication process of the ECU may be stopped as a fail-safe process for preventing abnormal running of the vehicle. As a method of stopping communication, there is a method of stopping communication on hardware such as communication stop by software that controls a communication circuit in a microcomputer, power cutoff of a transceiver, and communication mode switching. In executing these communication suspensions, it is necessary to diagnose whether or not the communication suspension can be reliably executed. As a method of diagnosing normality / abnormality of a communication circuit, a loopback test is used as in Patent Document 1.

In the loopback test used in Patent Document 1, when there is no request to execute the loopback test, the signal transmitted from the communication circuit in the microcomputer uses an opening / closing means and a transceiver controlled in a closed state. It is output to the external transmission line via the system and returned to the communication circuit in the microcomputer. The microcomputer diagnoses whether or not the cause of the communication error is on the own station side by comparing the transmission data and the reception data in the communication circuit, and saves the diagnosis result as diagnostic information.

Further, in the loopback test of the communication device described in Patent Document 1, when there is a request to execute the loopback test, the data signal output from the transmission means in the communication circuit is controlled to the open state. It is blocked by the opening / closing means and is not output to the external transmission line, but is selected by the signal selection means and sent to the receiving means. This makes it possible to execute a loopback test limited to the inside of the communication device.

JP-A-2003-244169

However, the loopback test described in Patent Document 1 has the following inconveniences. Multiple ECUs are connected on the CAN bus, and as a prerequisite for diagnosis on the own station side, all ECUs on the other station side must be normal, and in a state where a communication abnormality has occurred, the own station It is not possible to distinguish between an abnormality on the side and an abnormality on the other station side only by the vehicle control signal. Therefore, in order to distinguish between an abnormality on the own station side and an abnormality on the other station side, a diagnosis-only message is defined separately from the vehicle control, and mutual diagnosis is carried out between the own station side and the other station side. It is also possible. In this case, it is necessary to send a diagnostic message (test data) that is unnecessary for vehicle control on the CAN bus, but a collision between the sent diagnostic message and the transmission data of another station is likely to occur. , Communication speed will drop.

Further, since a plurality of ECUs mounted on a vehicle are generally manufactured by a plurality of manufacturers, not by a single manufacturer, it is impossible for a certain manufacturer to independently determine diagnostic specifications.

Further, in Patent Document 1, a loopback diagnosis is performed in the communication device of the own station with the opening / closing means closed. For this reason, when an actual communication abnormality occurs, if the communication device of the own station is normal, the abnormality can be considered as an abnormality on the transceiver of the own station or the other station side, and the location where the abnormality occurs only by this diagnosis. Cannot be identified.

The present invention has been made in view of the above circumstances, and is a vehicle capable of performing a communication diagnosis by the own station alone without transmitting a diagnostic signal to the vehicle communication network and identifying an abnormal part of the own station in more detail than before. It is an object of the present invention to provide an electronic control device for use.

In order to solve the above problems, the vehicle electronic control device of one aspect of the present invention is a vehicle electronic control device that controls the operation of a controlled object by using a vehicle communication network, and is a vehicle communication network. A communication cutoff state provided between a transceiver that sends and receives data signals to and from a constituent transmission line, a microcomputer that sends and receives data signals between the transceiver, and the transceiver and the transmission line, and blocks communication with the transmission line. Alternatively, the microcomputer includes a cutoff circuit that switches to a communication connection state that enables communication with the transmission line, and the microcomputer switches the cutoff circuit to the communication cutoff state to diagnose the transceiver.

According to at least one aspect of the present invention, the microcomputer diagnoses the transceiver by switching the cutoff circuit provided between the transmission line constituting the vehicle communication network and the transceiver to the communication cutoff state. As a result, the communication diagnosis can be performed by the own station independently without transmitting the diagnostic signal to the vehicle communication network, and the abnormal part of the own station can be identified in more detail than before.
Issues, configurations and effects other than those described above will be clarified by the following description of the embodiments.

It is a block diagram which shows the structural example of the electronic control device (single transceiver) for a vehicle which concerns on 1st Embodiment of this invention. It is a block diagram which shows the hardware configuration example of the microcomputer which concerns on 1st Embodiment of this invention. It is a block diagram which shows the diagnostic function example of the controller which concerns on 1st Embodiment of this invention. It is a figure which shows an example of the data flow at the time of loopback diagnosis in the electronic control device for a vehicle which concerns on 1st Embodiment of this invention. It is a flowchart which shows the procedure example of the communication diagnosis processing of the electronic control device for a vehicle which concerns on 1st Embodiment of this invention. It is a flowchart which shows the subroutine of the transceiver diagnostic processing in FIG. It is a block diagram which shows the structural example of the electronic control device (a plurality of transceivers) for a vehicle which concerns on 2nd Embodiment of this invention. It is a figure which shows an example of the data flow at the time of loopback diagnosis in the electronic control device for a vehicle which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the subroutine of the transceiver diagnostic processing which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the subroutine of the channel diagnosis processing in FIG. It is a figure which shows the transceiver diagnostic truth table which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the structural example of the electronic control device (single transceiver) for a vehicle which concerns on 1st example (reception only mode) of 3rd Embodiment of this invention. It is a block diagram which shows the structural example of the electronic control device (a plurality of transceivers) for a vehicle which concerns on 2nd example (communication stop mode) of 3rd Embodiment of this invention.

Hereinafter, an example of a mode for carrying out the present invention will be described with reference to the accompanying drawings. In the present specification and the accompanying drawings, components having substantially the same function or configuration are designated by the same reference numerals, and duplicate description will be omitted.

<1. First Embodiment>
[Overall configuration of electronic control device for vehicles]
First, the configuration of the electronic control device for vehicles (single transceiver) according to the first embodiment of the present invention will be described.
FIG. 1 is a block diagram showing a configuration example of an electronic control device for a vehicle (single transceiver) according to the first embodiment. In this embodiment, ECUs 1A, 1B, and 1C as electronic control devices for vehicles are systems that perform CAN communication, and each ECU includes one transceiver (CAN transceiver).

A CAN (an example of a vehicle communication network) adopted for vehicle control is used between a plurality of control units such as ECU 1A (engine ECU), ECU 1B (brake ECU), and ECU 1C (transmission ECU) via a transmission path 9. It is connected to, and data of various in-vehicle sensors, actuators, etc. is shared between these control units. Hereinafter, when ECU 1A, 1B, and 1C are not distinguished, they are described as ECU 1.

Generally, the ECU 1 includes a microcomputer (hereinafter referred to as “microcomputer”) 2. The microcomputer 2 is composed of a one-chip microcomputer in which a controller (so-called CAN controller) 20, a timer circuit 26, an A / D conversion circuit 27, and the like are integrally built (see FIG. 2 for details). The microcomputer 2 incorporating the controller 20 is provided with a large number of connection terminals (input / output terminals), two of which are a transmission terminal TX for transmitting a diagnostic message M (an example of a diagnostic signal) and a transmission terminal TX. It is a receiving terminal RX that receives a reply message (an example of a reply signal) to the diagnostic message M.

Further, the microcomputer 2 has an output terminal Ry1 to which the diagnostic relay signal S1 (an example of a switching signal) is output, a monitor terminal Rm1 to which the diagnostic relay signal output from the output terminal Ry1 is input, and an output terminal of the sub-microcomputer 3. The monitor terminal Rm2 to which the diagnostic relay signal S2 (example of switching signal) output from Ry2 is input and the monitor signal (example of status signal) output from the cutoff circuit 5 that received the diagnostic relay signal are input. The monitor terminal Cm is provided. Further, the microcomputer 2 includes an output terminal Sw that outputs a mode switching signal for switching the transmission / reception mode (for example, communication stop mode, reception-only mode, etc.) of the transceiver 4.

Further, each ECU 1 is provided with a transceiver 4 that executes data communication processing, and each ECU 1 is connected to a transmission line 9 (so-called CAN bus) composed of twisted pair lines via the transceiver 4. The transceiver 4 includes a driver (transmission circuit section) and a receiver (reception circuit section).

Each ECU 1 includes a power supply circuit 8, and power is supplied from the power supply circuit 8 to each part in the ECU 1 according to an instruction from the microcomputer 2.

Further, as shown in FIG. 1, the ECU 1 may include a sub-microcomputer 3 for diagnosing normality / abnormality of the microcomputer 2. The microcomputer 2 and the sub-microcomputer 3 mutually monitor the status. Therefore, for example, one microcomputer gives an example message, the other microcomputer answers the example, and if the answer is as expected, it is diagnosed as normal (generally called example arithmetic diagnosis). ) It has a function. Example When an abnormal state is diagnosed by arithmetic diagnosis, one of the microcomputers has a function (fail safe) to transition to a safe state in terms of vehicle control, such as performing power cutoff processing or communication stop processing. There is also. The sub-microcomputer 3 has basically the same configuration as the microcomputer 2, and includes an output terminal Ry2 corresponding to the output terminal Ry1.

Further, the microcomputer 2 executes a process of converting transmission data and reception data into a communication signal according to the CAN protocol according to its hardware configuration and software configuration, and with another ECU 1 via the transceiver 4 and the transmission line 9. Perform communication control. At the same time, the microcomputer 2 performs monitoring for detecting a plurality of types of communication errors such as a bit error, a bit staff error, a CRC error, a form error, and an ACK error. Then, when an error is detected, error processing such as transmitting error data from the transmission terminal TX and notifying another ECU 1 of the occurrence of the error is performed. Therefore, the microcomputer 2 has the functions of an error detecting means and an error data transmitting means.

By the way, when some abnormality occurs in the vehicle, the communication of a certain ECU 1 may be stopped for the purpose of safely evacuating the vehicle in operation. As the method, there is a method of controlling the power cutoff and transmission / reception mode switching of the transceiver 4 by the signal output from the microcomputer 2 and the sub-microcomputer 3 (details are not shown). In order to ensure that the CAN communication is stopped by the above method, the functions of the error detecting means and the error data transmitting means of the microcomputer 2 described above are used.

In the present embodiment, as shown in FIG. 1, a cutoff circuit 5 is installed between the transceiver 4 and the transmission line 9. A diagnostic relay signal (an example of a diagnostic signal) output from the sub-microcomputer 3 or the microcomputer 2 is input to the cutoff circuit 5. The cutoff circuit 5 includes a communication switching circuit 6 for cutting off the connection between the transceiver 4 and the transmission line 9 when the diagnostic relay signal is in the on state (hereinafter, “on”).

The communication switching circuit 6 is capable of communicating with a communication cutoff state or a transmission line 9 that cuts off communication with the transmission line 9 in response to a diagnostic relay signal instructing state switching output from the sub-microcomputer 3 or the microcomputer 2. Switch to the communication connection status. The connection between the transceiver 4 and the transmission line 9 is cut off by the communication switching circuit 6, but by installing a terminating resistor in the cutoff circuit 5, the data signal transmitted from the microcomputer 2 of the own station can be sent to the transceiver 4 and the cutoff circuit. It becomes possible to receive the signal as it is by the microcomputer 2 of the own station via 5.

Further, the ECU 1 includes an OR circuit (OR circuit) 7. In the case of the ECU 1 having the configuration in which the sub-microcomputer 3 is mounted, as shown in FIG. 1, the diagnostic relay signal output from the sub-microcomputer 3 and the microcomputer 2 is input to the OR circuit 7, and the output signal of the OR circuit 7 is a cutoff circuit. The configuration may be input to 5.

[Microcomputer configuration]
Next, the hardware configuration of the microcomputer 2 will be described.
FIG. 2 is a block diagram showing a hardware configuration example of the microcomputer 2. The microcomputer 2 includes a controller 20, a non-volatile memory 25, a timer circuit 26, an A / D (Analog / digital) conversion circuit 27, and a communication circuit 28, which are connected to each other via a system bus 24.

The controller 20 is composed of a CPU (central processing unit) 21, a ROM (Read Only Memory) 22, and a RAM (Random Access Memory) 23. When the CPU 21 executes the control program recorded in the ROM 22, each function of the controller 20 in the present embodiment is realized. Although a CPU is used as the processor, another processor such as an MPU (micro processing unit) may be used. The non-volatile memory 25 is an auxiliary storage device including a semiconductor memory or the like, and a control program may be stored in the non-volatile memory 25.

The timer circuit 26 is a circuit for measuring time. For example, the timer circuit 26 measures the elapsed time from the reference time point according to the instruction of the controller 20, and outputs the measurement data to the controller 20. The A / D (Analog / digital) conversion circuit 27 converts the input analog signal into a digital signal and outputs it to the controller 20.

The communication circuit 28 communicates with other blocks in the ECU 1 and other ECUs via the transmission line of the vehicle LAN. The communication circuit 28 may have the function of the A / D conversion circuit 27 and may be configured to process the input / output signals of each sensor and each actuator.
You may.

[Controller diagnostic function]
Next, the diagnostic function of the controller 20 will be described.
FIG. 3 is a block diagram showing an example of a diagnostic function of the controller 20. When the CPU 21 executes the control program recorded in the ROM 22, the function of each block shown in FIG. 3 is realized.

As shown in FIG. 3, the controller 20 includes a diagnosis unit 31, a pre-diagnosis processing unit 32, a mode switching signal output unit 33, and a fail-safe processing unit 34.

The diagnosis unit 31 is a processing unit that diagnoses a function for communicating with the transmission line 9 when the cutoff circuit 5 is in a communication cutoff state. For example, the diagnosis unit 31 diagnoses communication via a target block (for example, transceiver 4) in the ECU 1 and normality / abnormality of each block. After transmitting the diagnostic message to the cutoff circuit 5 via the transceiver 4, the diagnostic unit 31 receives a reply message to the diagnostic message from the cutoff circuit 5, and based on the result of comparing the diagnostic message and the reply message, Diagnose the communication function including the transceiver 4.

The diagnosis pre-processing unit 32 is a processing unit that diagnoses a communication cutoff function that cuts off communication with the transmission line 9 in the cutoff circuit 5 as pre-processing before the diagnosis unit 31 makes a diagnosis.

The switching signal output unit 33 is a processing unit that outputs a diagnostic relay signal instructing the cutoff circuit 5 to switch to the communication cutoff state or the communication connection state in accordance with the instruction of the diagnosis unit 31.

The fail-safe processing unit 34 is a processing unit that receives the diagnosis result of the diagnosis unit 31 and performs fail-safe processing such as functional degradation and power off.

[Data flow during loopback diagnosis]
Next, the loopback diagnosis in the ECU 1A will be described.
FIG. 4 is a diagram showing an example of a data flow at the time of loopback diagnosis in the ECU 1A. The loopback diagnosis in the present embodiment includes an internal loopback diagnosis and an external loopback diagnosis. FIG. 4 shows the data flow Lb1 at the time of external loopback diagnosis. Further, the data flow Lb2 when returning the monitor signal to the diagnostic relay signal input to the cutoff circuit 5 (during the communication cutoff function diagnosis) is also shown.

In the internal loopback diagnosis, in the controller 20 of the microcomputer 2, the CPU 21 outputs a diagnostic message, and the CPU 21 receives the message to perform a self-diagnosis of the controller 20. Alternatively, the controller 20 of the microcomputer 2 may output a diagnostic message, which may be received by the controller 20 via the communication circuit 28. The internal loopback diagnosis may be implemented as a standard function of the microcomputer 2.

In the external loopback diagnosis, the microcomputer 2 transmits a diagnostic message M from the transmission terminal TX to the cutoff circuit 5 via the transceiver 4 while the cutoff circuit 5 is in the communication cutoff state. When the transceiver 4 and the cutoff circuit 5 are normal, the cutoff circuit 5 receives the diagnostic message M via the transceiver 4 and transmits a reply message to the diagnostic message M to the microcomputer 2. Then, the microcomputer 2 receives the reply message at the reception terminal RX.

Further, in the communication cutoff function diagnosis, the diagnostic relay signal S1 or S2 output by the microcomputer 2 or the sub-microcomputer 3 is input to the cutoff circuit 5 via the OR circuit 7. When the cutoff circuit 5 is normal, the cutoff circuit 5 returns a monitor signal to the microcomputer 2, and the microcomputer 2 receives the returned monitor signal at the monitor terminal Cm. The monitor signal indicates the current state (communication cutoff state or communication connection state) of the cutoff circuit 5.

[Communication diagnostic processing]
Next, the procedure of the communication diagnosis processing of the ECU 1A will be described.
FIG. 5 is a flowchart showing a procedure example of the communication diagnosis process of the ECU 1A. The procedure example of the communication diagnosis processing of the ECU 1 shown in FIG. 5 is common to the ECU 101 (FIG. 7) of the second embodiment described later. The communication diagnosis process of the ECU 1A will be described below, but the same applies to the other ECUs 1B and 1C.

First, the diagnosis unit 31 of the controller 20 determines whether or not the diagnosis request has been received (S1), and if the diagnosis request is not received (NO in S1), the controller 20 performs normal processing such as starting the engine (NO). S7). For example, this communication diagnostic process is executed before the engine is started. The timing at which the diagnosis request is input to the controller 20 is, for example, when the power of the ECU 1A is turned on (the ignition key is turned on). After the process of step S7, the process of this flowchart ends.

On the other hand, when the diagnosis unit 31 receives the diagnosis request (YES in S1), the diagnosis unit 31 executes the subsequent communication diagnosis process. When a diagnosis request is made, the diagnosis unit 31 instructs the switching signal output unit 33 to output the diagnosis relay signal S1 to the cutoff circuit 5. Then, the pre-diagnosis processing unit 32 performs wait processing after outputting the diagnostic relay signal S1 according to the instruction of the diagnostic unit 31 (S2). The diagnostic relay signal may be output from the sub-microcomputer 3 instead of the microcomputer 2. Whether to output the diagnostic relay signal from the microcomputer 2 or the sub-microcomputer 3 is set in advance in each controller 20.

Then, when the pre-diagnosis processing unit 32 detects that the specified time has elapsed based on the timer signal of the timer circuit 26 (see FIG. 2) (after the time until the diagnostic relay signal is turned on), It is determined that the diagnostic relay signal is output from the corresponding microcomputer and that the monitor signal output from the cutoff circuit 5 is normal (S3).

When it cannot be confirmed that the diagnostic relay signal is output from the corresponding microcomputer in the cutoff circuit 5 and the monitor signal output from the cutoff circuit 5 is normal, that is, the cutoff circuit 5 and the transmission line are connected by the communication switching circuit 6. If the communication with 9 cannot be normally blocked (NO in S3), the pre-diagnosis processing unit 32 determines that the communication blocking function is abnormal and causes the fail-safe processing unit 34 to execute the fail-safe processing (S8). ). After the process of step S8, the process of this flowchart ends.

Next, when the communication cutoff function of the cutoff circuit 5 is normal (communication cutoff is possible normally), the diagnostic unit 31 receives the diagnosis result of the pre-diagnosis processing unit 32 and executes the transceiver diagnostic process ( S4), it is determined whether or not the transceiver 4 is normal (S5). The details of the transceiver diagnostic process in step S4 will be described later with reference to FIG.

Here, when the diagnostic unit 31 determines that the transceiver 4 is normal (YES in S5), the diagnostic unit 31 determines that the transceiver 4 is normal and ends the communication diagnosis process of FIG. 5 (S6). On the other hand, when the diagnostic unit 31 determines that the transceiver 4 is not normal (NO in S5), the fail-safe processing unit 34 determines that an abnormality has occurred in the transceiver 4 or the controller 20 and performs fail-safe processing. Execute (S9).

The controller 20 ends the communication diagnosis process of FIG. 5 after the process of step S6 or S9 is completed. As described above, the controller 20 executes the fail-safe process when the transceiver 4 cannot be determined to be normal as a result of the transceiver diagnosis process in step S4, and ends the communication diagnosis process when the transceiver 4 is normal. ..

[Subroutine for transceiver diagnostic processing]
Here, the subroutine of the transceiver diagnostic processing in step S4 of FIG. 5 will be described.
FIG. 6 is a flowchart showing a subroutine of the transceiver diagnostic processing in step S4. In a system such as FIG. 1 in which the transmission line to which the ECU 1A is connected is one (transmission line 9), the transceiver diagnosis process in step S4 executes the procedure shown in FIG.

First, the diagnostic unit 31 of the controller 20 executes the internal loopback diagnostic process (S11). In the internal loopback diagnosis process of step S1, the controller diagnosis of the conventional method is performed.

Next, the diagnosis unit 31 determines whether or not the result of the internal loopback diagnosis is normal (S12). When the result of the internal loopback diagnosis is abnormal (NO in S12), since the controller 20 has an abnormality, the fail-safe processing unit 34 executes the fail-safe processing (S16).

On the other hand, when the result of the internal loopback diagnosis is normal (YES in S12), the diagnosis unit 31 executes the external loopback diagnosis process (S13). First, the switching signal output unit 33 outputs a diagnostic relay signal to the cutoff circuit 5, and puts the cutoff circuit 5 into a communication cutoff state. Next, when the cutoff circuit 5 is in the communication cutoff state, the diagnostic unit 31 outputs a diagnostic message M to the cutoff circuit 5 via the transmission terminal TX of the microcomputer 2 and the transceiver 4. Then, the diagnostic unit 31 receives the reply message via the transceiver 4 and the reception terminal RX, and diagnoses the transceiver based on the result of comparing the diagnostic message M and the reply message.

Next, the diagnosis unit 31 determines whether or not the result of the external loopback diagnosis is normal (S14). Here, the diagnostic unit 31 determines that the controller 20 and the transceiver 4 are normal when the result of the external loopback diagnosis is normal, that is, when the diagnostic message M and the reply message match (YES in S14). (S15). In addition to the case where the reply message matches the diagnostic message, the external loopback diagnosis may be judged to be normal even when the reply message has the expected contents.

On the other hand, when the result of the external loopback diagnosis is not normal, that is, when the diagnostic message M and the reply message do not match (NO in S14), the diagnostic unit 31 determines that the transceiver 4 is abnormal (S17). .. Then, upon receiving the determination of the diagnosis unit 31, the fail-safe processing unit 34 executes the fail-safe processing. After the processing of steps S15, S16 or S17, the transceiver diagnostic processing of FIG. 6 is terminated.

As described above, the vehicle electronic control device (ECU 1A) that controls the operation of the controlled object by using the vehicle communication network according to the first embodiment is set in the transmission line (transmission line 9) constituting the vehicle communication network. Communication that is provided between a transceiver (transceiver 4) that transmits and receives data signals, a microcomputer (microcomputer 2) that transmits and receives data signals between the transceiver, and the transceiver and a transmission line, and blocks communication with the transmission line. It is provided with a cutoff circuit (cutoff circuit 5) that switches to a cutoff state or a communication connection state that enables communication with a transmission line. Then, the microcomputer switches the cutoff circuit to the communication cutoff state to diagnose the transceiver.

According to the first embodiment of the above configuration, the microcomputer switches the cutoff circuit provided between the transmission line constituting the vehicle communication network and the transceiver to the communication cutoff state, and diagnoses the transceiver. In this way, by not transmitting the diagnostic signal to the vehicle communication network, the communication diagnosis can be performed independently by the own station regardless of the state of the other station. Further, by arranging the cutoff circuit between the transceiver and the transmission line, if the own station is out of order at the time of communication diagnosis, the abnormal part of the own station can be identified in more detail than before. Further, the microcomputer can prevent unnecessary diagnostic signals from being transmitted to the transmission line by switching the cutoff circuit to the communication cutoff state before the communication diagnosis.

Further, as described above, in the vehicle electronic control device (ECU 1A) of the present embodiment, the microcomputer (microcomputer 2) is cut off via the transceiver (transceiver 4) when the cutoff circuit (cutoff circuit 5) is in the communication cutoff state. A diagnostic signal (diagnostic message M) is output to the circuit, the cutoff circuit outputs a reply signal (reply message) to the diagnostic signal input via the transceiver to the transceiver, and the microcomputer outputs the reply signal (reply message) to the transceiver via the transceiver. The transceiver signal is received, and the transceiver is diagnosed based on the result of comparing the received diagnostic signal with the reply signal.

According to the above configuration, the communication diagnosis can be performed by the own station independently regardless of the state of the other station. In addition, by outputting a diagnostic signal from the microcomputer to the transceiver circuit via the transceiver and returning the reply signal to the diagnostic signal to the transceiver in the interrupt circuit, if the own station is out of order, it will be self-sufficient. It is possible to identify the abnormal part of the station in more detail than before.

Further, as described above, in the vehicle electronic control device (ECU 1A) of the present embodiment, the microcomputer (microcomputer 2) has a switching signal (diagnostic relay signal S1 or) for instructing switching to a communication cutoff state or a communication connection state. S2) is output to the cutoff circuit (cutoff circuit 5), and the cutoff circuit switches to the communication cutoff state or the communication connection state according to the received switching signal, and the state signal (monitor signal) indicating the communication cutoff state or the communication connection state. Is output to the microcomputer.

According to the above configuration, it is possible to diagnose the normality / abnormality of the cutoff circuit, and thereby it is possible to monitor the cutoff state and the connection state of the communication between the cutoff circuit (electronic control device for a vehicle) and the transmission line. By confirming the status signal indicating that the cutoff circuit has been switched to the communication cutoff state before the communication diagnosis, it is possible to prevent the diagnosis signal from being sent to the transmission line at the time of the communication diagnosis.

Further, as described above, in the vehicle electronic control device (ECU 1A) in the present embodiment, as the microcomputer, the first microcomputer (microcomputer 2) and the second microcomputer (sub) that monitors the first microcomputer are used. The first microcomputer or the second microcomputer has a microcomputer 3) and outputs a switching signal (diagnostic relay signal S1 or S2) to the breaking circuit (breaking circuit 5), and states from the breaking circuit. Upon receiving the signal (monitor signal), the first microcomputer outputs the diagnostic signal (diagnosis message M) and receives the reply signal to diagnose the transceiver (transceiver 4).

According to the above configuration, when an abnormality occurs in the first microcomputer and the communication cutoff cannot be instructed to the cutoff circuit, the second microcomputer can instruct the communication cutoff.

<2. Second embodiment>
The ECU 1 in the first embodiment includes one transceiver 4 (single transceiver), but in the second embodiment, one ECU includes a plurality of transceivers.

[Overall configuration of electronic control device for vehicles]
Hereinafter, the configuration of the vehicle electronic control device (plurality of transceivers) according to the second embodiment will be described.
FIG. 7 is a block diagram showing a configuration example of the vehicle electronic control device (plurality of transceivers) according to the second embodiment. In this embodiment, the ECUs 101A, 101B, and 101C as electronic control devices for vehicles are systems that perform CAN communication, and each ECU includes a plurality of transceivers (four in FIG. 7). Here, the ECU 101A will be described, but the same applies to the ECUs 101B and 101C. Hereinafter, when the ECUs 101A, 101B, and 101C are not distinguished, they are described as the ECU 101.

The ECU 101A includes a microcomputer 102, a sub-microcomputer 103, transceivers 104a to 104d, a cutoff circuit 105, an OR circuit 7, and a power supply circuit 8. The microcomputer 102 includes a plurality of controllers 20a to 20d. Further, the cutoff circuit 105 includes communication switching circuits 106a to 106d and an internal transmission line 109.

The microcomputer 102, the sub-microcomputer 103, the transceivers 104a to 104d, and the breaking circuit 105 correspond to the microcomputer 2, the sub-microcomputer 3, the transceiver 4, and the breaking circuit 5 shown in FIG. Further, the plurality of controllers 20a to 20d of the microcomputer 102 correspond to the controllers 20 of the microcomputer 2, and the communication switching circuits 106a to 106d of the breaking circuit 105 correspond to the communication switching circuit 6 of the breaking circuit 5.

In the system shown in FIG. 7, a vehicle communication network is configured by using transmission lines 9a to 9d of a plurality of systems. For example, ECU 101B and ECU 101C are connected to the transmission line 9a, ECU 101D and ECU 101E are connected to the transmission line 9b, ECU 101F and ECU 101G are connected to the transmission line 9c, and ECU 101H and ECU 101I are connected to the transmission line 9d. The transceivers 104a to 104d are connected to different transmission lines 9a to 9d, and communication switching circuits 106a to 106d are arranged on the transmission lines 9a to 9d.

The microcomputer 102 basically has the same configuration as the microcomputer 2 in the first embodiment. However, the microcomputer 102 includes four controllers 20a to 20d corresponding to the four transceivers 104a to 104d. Further, a pair of transmission terminal TX and reception terminal RX are provided according to the number of transceivers. That is, the microcomputer 102 includes a transmission terminal TX1 and a reception terminal RX1 connected to the controller 20a corresponding to the transceiver 104a, and a transmission terminal TX2 and a reception terminal RX2 connected to the controller 20b corresponding to the transceiver 104b. Further, the microcomputer 102 includes a transmission terminal TX3 and a reception terminal RX3 connected to the controller 20c corresponding to the transceiver 104c, and a transmission terminal TX4 and a reception terminal RX4 connected to the controller 20d corresponding to the transceiver 104d.

Further, the microcomputer 102 outputs a mode switching signal for switching the transmission / reception mode of the output terminal Ry1, the monitor terminal Rm1, the monitor terminal Rm2, the monitor terminal Cm, and the transceivers 104a to 104d, as in the first embodiment. The output terminals Sw1 to Sw4 are provided. The sub-microcomputer 103 has the same configuration as this, and includes an output terminal Ry2 corresponding to the output terminal Ry1.

The controllers 20a to 20d basically have the functions shown in FIG. However, only the main controller, for example, the controller 20a may include the switching signal output unit 33. In FIG. 7, four controllers 20a to 20d are illustrated, but the number of controllers is not limited to four, and may be one or any number of controllers.

Similar to the first embodiment (see FIG. 1), the communication switching circuits 106a to 106d of the cutoff circuit 105 are connected to the transceivers 104a to 104d by the diagnostic relay signal S1 output from the sub-microcomputer 103 or the microcomputer 102. The connection with 9a to 9d is cut off. A terminating resistor is provided in the cutoff circuit 105, and the communication switching circuits 106a to 106d are circuits that switch the transceivers 104a to 104d so that they are connected on one internal transmission line 109 when the diagnostic relay signal is on. Have.

With such a configuration, the data signal transmitted from the microcomputer 102 of the own station is directly transmitted to the microcomputer 102 of the own station via the transceivers 104a to 104d and the communication switching circuits 106a to 106d, as in the system of FIG. It becomes possible to receive at. Further, since the internal transmission line 109 is configured in the ECU 101A, it is possible to make a diagnosis in a state where the ECU 101A is cut off from the external ECUs 101B to 101I. Therefore, when some kind of communication abnormality occurs in the vehicle, it is possible to identify the abnormal ECU 101 and the faulty part in more detail.

The system of FIG. 7 includes four communication switching circuits 106a to 106d corresponding to the transmission lines 9a to 9d (the number of systems) constituting the vehicle communication network. For example, the communication switching circuit has one. It may be any of them, and it may be configured or combined according to the importance of function. In the following description, the system of the transmission line 9a is referred to as ch1 (first channel), and the systems of the transmission lines 9b to 9d are referred to as ch2 (second channel) to ch4 (fourth channel), respectively. For example, the transceiver 104a for transmitting and receiving data signals using the transmission line 9a is expressed as "transceiver 104a of ch1".

[Data flow during loopback diagnosis]
Next, the loopback diagnosis in the ECU 101A will be described.
FIG. 8 is a diagram showing an example of a data flow at the time of loopback diagnosis in the ECU 101A. FIG. 8 shows the data flow Lb1 at the time of external loopback diagnosis. Here, it is assumed that the diagnostic message M1 is output from the transmission terminal TX1 of the microcomputer 102.

At the time of external loopback diagnosis, the diagnostic relay signal output from the microcomputer 102 or the sub-microcomputer 103 is input to the cutoff circuit 105, and the communication switching circuits 106a to 106d of the cutoff circuit 105 are switched to the communication cutoff state, respectively, and the transmission lines 9a to 9d. Block communication with. Then, when the controller 20a of the microcomputer 102 outputs the diagnostic message M1 from the transmission terminal TX1, if the ECU 101A is normal, the diagnostic message M1 is input to the communication switching circuit 106a of the cutoff circuit 105 via the transceiver 104a. Will be done.

The communication switching circuit 106a returns a reply message to the diagnostic message M1 to the microcomputer 102 via the transceiver 104a. In parallel with this, the communication switching circuit 106a transfers the diagnostic message M1 to the communication switching circuits 106b to 105d via the internal transmission line 109. The communication switching circuits 106b to 105d each transmit a reply message to the diagnostic message M1 transferred from the communication switching circuit 106a to the microcomputer 102 via the transceivers 104b to 104d. Then, the controllers 20a to 20d each receive the reply message transmitted by the communication switching circuits 106a to 105d by the receiving terminals RX1 to RX4.

If there is an abnormality on the path of the external loopback starting from the transmission terminal TX1 (ch1), the diagnostic message M1 is not received by any or all of the reception terminals RX1 to RX4 of the microcomputer 102. In this way, by appropriately performing the external loopback diagnosis via the transceivers 104a to 14d of ch1 to ch4, it is possible to determine the abnormality of the transceivers 104a to 104d of ch1 to ch4.

The data flow at the time of internal loopback and the data flow of the diagnostic relay signal and the monitor signal in each of the transceivers 104a to 104d are the same as in the case of the first embodiment, and illustration and description thereof will be omitted.

[Subroutine for transceiver diagnostic processing]
Also in the ECU 101A of FIG. 7, the communication diagnosis process shown in FIG. 4 is performed. In a system having a plurality of transmission lines (transmission lines 9a to 9d) to which the ECU 101A is connected, the transceiver diagnostic process (S4) of FIG. 4 executes the procedure shown in FIGS. 9 and 10.

FIG. 9 is a flowchart showing a subroutine of the transceiver diagnosis process in step S4. First, the diagnostic unit 31 of the controller 20 performs ch1 diagnostic processing (S21). The ch1 diagnostic process in step S21 executes the procedure shown in FIG. Here, the subroutine of the channel diagnosis processing in steps S21, S24, S27, and S30 will be described.

(Subroutine of channel diagnostic processing)
FIG. 10 is a flowchart showing a subroutine of channel diagnosis processing in steps S21, S24, S27, and S30. Here, ch1 to ch4 correspond to the transceivers 104a to 104d shown in FIG. 7, and the systems of the transmission lines 9a to 9d to which these transceivers 104a to 104d are connected, respectively.

First, the diagnostic unit 31 (ch1) of the controller 20a performs a process of transmitting a diagnostic message M1 from the transmission terminal TX1 of the microcomputer 102 to the transceiver 104a and a reception wait wait process (S41). The diagnostic message transmitted from the transmission terminal TX1 is input to the communication switching circuit 106a of the cutoff circuit 105 via the transceiver 104a, and then transferred to the communication switching circuits 106b to 106d. Then, the reply message transmitted from the communication switching circuits 106a to 106d is received by the receiving terminals RX1 to RX4 of the microcomputer 102 via the transceivers 104a to 104d.

Next, the diagnostic unit 31 of the controller 20b determines whether or not the diagnostic message of ch2 has been received at the reception terminal RX2 (S42). The diagnostic unit 31 confirms the consistency between the diagnostic message M1 transmitted from the transmission terminal TX1 of the microcomputer 102 and the reply message received at the reception terminal RX2. Then, when the diagnostic message M1 and the reply message match (YES in S42), the diagnostic unit 31 determines that ch2 is normal (S43), and when they do not match (NO in S42), ch2 is regarded as a temporary abnormality. Judgment (S44).

Next, the diagnostic unit 31 of the controller 20c determines whether or not the diagnostic message of ch3 has been received at the reception terminal RX3 (S45). The diagnostic unit 31 confirms the consistency between the diagnostic message M1 transmitted from the transmission terminal TX1 of the microcomputer 102 and the reply message received at the reception terminal RX3. Then, when the diagnostic message M1 and the reply message match (YES in S45), the diagnosis unit 31 determines that ch3 is normal (S46), and when they do not match (NO in S45), ch3 is regarded as a temporary abnormality. Judgment (S47).

Next, the diagnostic unit 31 of the controller 20d determines whether or not the diagnostic message of ch4 has been received at the reception terminal RX4 (S48). The diagnostic unit 31 confirms the consistency between the diagnostic message M1 transmitted from the transmission terminal TX1 of the microcomputer 102 and the reply message received at the reception terminal RX3. Then, the diagnosis unit 31 determines that ch4 is normal (S49) when the diagnostic message M1 and the reply message match (YES in S48), and sets ch4 as a temporary abnormality when they do not match (NO in S48). Judgment (S50). After determining the state of ch4 in step S49 or S50, the process proceeds to step S22 of FIG.

If the diagnostic message M1 and the reply message do not match in all of the receiving terminals RX2 to RX4, there is a possibility that an abnormality has occurred in the transceiver 104a of ch1. Therefore, in FIG. 10, as described in steps S44, S47 and S50, the states of ch2 to ch4 are set as temporary abnormalities.

Returning to the description of the transceiver diagnostic process of FIG. After the diagnosis process in step S21, the controller 20a performs an abnormality determination of the transceiver 104a of ch1 based on the result obtained by the channel diagnosis process of FIG. 10 (S22). Here, the diagnostic unit 31 of the controller 20a has not received the reply message at all of the reception terminals RX2 to RX4 and has not received the reply message at the reception terminal RX1 with respect to the diagnostic message M1 transmitted from the transmission terminal TX1. In some cases (YES in S22), ch1 is determined to be abnormal (S23).

On the other hand, when even one of the transceivers 104b to 104d is normal (the reply message to the diagnostic message M1 from the transmission terminal TX1 is received, and the diagnostic message M1 and the reply message match) (NO in S22). ), The temporary abnormal state determined in steps S44, S47, and S50 of FIG. 10 is determined as an abnormal state (S33). In this state, since it can be determined that the diagnostic message M1 transmitted from the transmission terminal TX1 is normally transmitted via the transceiver 104a, the diagnosis of the transceiver 104a is also determined to be normal and the diagnosis is terminated.

If all of ch2 to ch4 are provisionally abnormal in step S22, it is considered that the transceiver 104a is abnormal. In this case, since it means that the diagnosis of ch2 to ch4, that is, the transceivers 104b to 104d has not been performed, the ch2 diagnosis process of step S24 is executed.

The details of the ch2 diagnostic process in step S24 are the same as those in FIG. 10, and it is determined whether or not the diagnostic message M2 transmitted from the transmission terminal TX2 is normally received at the reception terminals RX1, RX3, RX4 of ch1, ch3, ch4. , Diagnose the health of transceivers 104a-104d. Since the diagnostic method and the determination method for ch2 to ch4 in step S24 and subsequent steps are the same as those for ch1, the description thereof will be omitted. After determining the state of each channel in steps S32 to S36, the process proceeds to step S5 of FIG.

After performing the transceiver diagnosis process in step S4 of FIG. 5, the microcomputer 102 (for example, the controller 20a) determines whether or not ch1 to ch4 are normal with reference to the states of ch1 to ch4 determined in FIG. 9 (S5). Then, when any one of ch1 to ch4 is abnormal (NO in S5), the fail-safe processing unit 34 executes the fail-safe processing in step S9, and when all are normal (NO). YES in S5), the communication diagnosis process of FIG. 5 is terminated.

In FIGS. 9 and 10, there is no diagnosis for identifying an abnormality in the controllers 20a to 20d inside the microcomputer 102 or an abnormality in the transceivers 104a to 104d, but the abnormality portion can be specified by the following method. In order to identify the abnormal part, for example, after executing the transceiver diagnosis process (S4 in FIG. 5), the internal loopback diagnosis (S11) as shown in FIG. 6 is performed on the channel diagnosed as abnormal in more detail. It is possible to identify an abnormal location. Alternatively, in the system of FIG. 7, the internal loopback diagnosis as shown in FIG. 6 is performed in advance for each channel, and the effectiveness of the functions of the controllers 20a to 20d inside the microcomputer 102 is diagnosed. Good.

[Transceiver diagnosis truth table]
Next, the transceiver diagnostic truth table will be described.
FIG. 11 shows a transceiver diagnostic truth table. FIG. 11 shows the reception status of each channel (reception terminals RX1 to RX4) when the diagnostic message M1 is transmitted from the transmission terminal TX1 (ch1) of the microcomputer 102 of the ECU 101A, and the content of processing according to the reception status. Is shown, and this transceiver diagnostic truth table is equivalent to the diagnostic results of FIGS. 9 and 10.

For example, in FIG. 11, No. 1 to No. The state of No. 8 corresponds to the state of step S33 of FIG. The state of 9 corresponds to the state of step S23 of FIG. When the diagnostic messages M2 to M4 are transmitted from the transmission terminals TX2 to TX4 (ch2 to ch4) (S24, S27, S30 in FIG. 9), the diagnostic message M1 is transmitted from the transmission terminals TX1 (ch1). The details are not shown because the idea is the same as the case. This transceiver truth table is created for each channel and stored in the RAM 23 or the non-volatile memory 25.

In FIGS. 9 and 10, the diagnosis is made in the order of ch1, ch2, ch3, ch4, but the order of the channels to be diagnosed is not limited to this example. For example, the microcomputer 2 may diagnose the plurality of transceivers 104a to 104d (ch1 to ch4) in the order in which they are less likely to fail. It is presumed that each transceiver has different susceptibility to failure depending on the number of ECUs 101 connected to the transmission line (system) used for communication, the control target of each ECU 101, and the like. The failure susceptibility index of each transceiver or the information related to the failure susceptibility is stored in the non-volatile memory 25 in advance.

For example, when the number of ECUs 101 connected to one transmission line is large, the number of data signals transmitted and received by the ECU 101 of the own station to and from the ECU 101 of another station increases, and the load on each ECU 101 increases. Further, depending on the type of control target of the ECU 101 connected to a certain transmission line, the number of data signals transmitted / received on the transmission line may be larger than that of other transmission lines. Further, the ECU 101 installed under severe conditions such as a place where the temperature is relatively high even in the same vehicle may be more likely to break down than other ECU 101s.

Therefore, the index indicating the susceptibility of the transceiver that is prone to failure is set to a value larger than that of the transceiver that is difficult to fail. Then, the microcomputer 2 diagnoses the plurality of transceivers (transceivers 104a to 104d) in ascending order of susceptibility to failure, that is, in order of resistance to failure. In this case, there is a possibility that the abnormal channel can be identified at an early stage in the transceiver diagnosis process of FIG. 9 and the time until the transceiver diagnosis process is completed can be shortened. As a result, the microcomputer 102 can complete the communication diagnosis process of FIG. 5 at an early stage and quickly move to the next control (for example, engine start, fail-safe process, etc.).

As described above, in the vehicle electronic control device (ECU 101A) of the second embodiment, the transceiver is provided corresponding to each of the plurality of transmission lines (transmission lines 9a to 9d) constituting the vehicle communication network. A plurality of transceivers (transceivers 104a to 104d) are provided, and a break circuit (break circuit 105) connects a plurality of transceivers so as to be able to communicate with each other in a communication cutoff state, and one transceiver in a state where a plurality of transceivers are connected. When a diagnostic signal (diagnostic message M1) is received from (for example, transceiver 104a), a process of outputting a reply signal to the diagnostic signal to the transceiver that outputs the diagnostic signal and other transceivers (transceivers 104b to 104d). I do.

For example, the vehicle electronic control device (ECU 101A) having the above-mentioned plurality of transceivers is configured as follows.
In the electronic control device for vehicles, the interruption circuit (interruption circuit 105) is a switching signal (diagnosis relay signal) between a plurality of transceivers (transceivers 104a to 104d) and a plurality of transmission lines (transmission lines 9a to 9d). A plurality of communication switching circuits (communication switching circuits 106a to 106d) configured to switch to a communication cutoff state or a communication connection state and to connect a plurality of transceivers to each other so as to be able to communicate with each other in the communication cutoff state are provided.
Then, the microcomputer (microcomputer 102) outputs a switching signal to the cutoff circuit to put the plurality of communication switching circuits in the communication cutoff state, and with the plurality of transceivers connected, via one transceiver (for example, transceiver 104a). A diagnostic signal (diagnosis message M1) is output to one communication switching circuit (communication switching circuit 106a). Next, the communication switching circuit that has received the diagnostic signal performs a process of transferring the diagnostic signal to another communication switching circuit (communication switching circuits 106b to 106d), and a plurality of communication switching circuits (communication switching circuits 106a to 106d). Each of the above outputs a reply signal to the diagnostic signal to each of the corresponding plurality of transceivers (transceivers 104a to 104d). Then, the microcomputer diagnoses a plurality of transceivers based on the reception status of the reply signals from the transceiver (for example, transceiver 104a) that outputs the diagnostic signal and the other transceivers (transceivers 104b to 104d).

According to the second embodiment of the above configuration, in addition to the same effect as that of the first embodiment, there are the following effects. That is, according to the second embodiment, in the electronic control device for vehicles connected to a plurality of transmission lines, the state of the transceiver installed in each transmission line can be diagnosed at once with one diagnostic signal. It is possible. Thereby, the diagnostic efficiency of the electronic control device for the vehicle can be improved.

Further, as described above, in the vehicle electronic control device (ECU 101A) of the present embodiment, the microcomputer (microcomputer 102) transmits the diagnostic signals (diagnostic messages M1 to M4) to the plurality of transceivers (transceivers 104a to 104d). It outputs in order, and diagnoses a plurality of transceivers based on the reception status of the return signal from the transceiver that outputs the diagnostic signal and the other transceivers.

According to the above configuration, the electronic control device for the vehicle can sequentially diagnose all the transceivers connected to the transmission line.

<3. Third Embodiment>
It is also possible to diagnose whether or not the transmission / reception mode switching function of the transceiver 4 (see FIG. 1) of the first embodiment and the transceivers 104a to 104d (see FIG. 7) of the second embodiment described above operates normally. It is possible.

[First example: Diagnosis of receive-only mode]
First, as a first example of the third embodiment, a diagnosis when the operation mode of the transceiver is set to the receive-only mode will be described.
FIG. 12 is a block diagram showing a configuration example of an electronic control device for a vehicle (single transceiver) according to the first example of the third embodiment. For example, a mode switching signal is output from the output terminal Sw of the microcomputer 2 of the ECU 1A to set the operation mode of the transceiver 4 to the reception-only mode, and a diagnostic relay signal S1 or S2 is output to the cutoff circuit 5 by the cutoff circuit 5. The diagnostic message M is transmitted from the transmission terminal TX of the microcomputer 2 in a state where communication with the transmission line 9 is cut off.

In this case, since the transceiver 4 has stopped the transmission function, the diagnostic message M1 is not transmitted from the transceiver 4 to the cutoff circuit 5. Therefore, the receiving terminal RX of the microcomputer 2 cannot receive the reply message to the diagnostic message M. In this way, it can be confirmed that the receive-only mode of the transceiver 4 is operating normally. Similarly, the receive-only mode can be diagnosed for the transceivers 104a (ch1) to 104d (ch4) of FIG.

[Second example: Diagnosis of communication stop mode]
Next, as a second example of the third embodiment, a diagnosis when the operation mode of the transceiver is set to the communication stop mode will be described.
FIG. 13 is a block diagram showing a configuration example of the vehicle electronic control device (plurality of transceivers) according to the fourth embodiment. For example, a mode switching signal is output from the output terminal Sw of the microcomputer 102 of the ECU 101A to set the operation mode of the transceiver 104a (ch1) to the communication stop mode (mode in which CAN communication is not performed), and the communication by the cutoff circuit 105 is cut off. , The diagnostic message M1 is transmitted from the transmission terminal TX1 of the microcomputer 102.

In this case, since the transceiver 104a has stopped the transmission function, the diagnostic message M1 is not transmitted from the transceiver 104a to the cutoff circuit 105. Therefore, the receiving terminals RX2 to RX4 of the microcomputer 102 cannot receive the reply message to the diagnostic message M1.

Further, when the diagnostic message M2 is transmitted from the transmission terminal TX2 of the microcomputer 102, the receiving terminal RX1 of the microcomputer 102 cannot receive the reply message to the diagnostic message M2 because the receiving function of the transceiver 104a is also stopped. In this way, it can be confirmed that the communication stop mode of the transceiver 104a is operating normally. Similarly, the communication stop mode of the transceivers 104b (ch2) to 104d (ch4) can be diagnosed. In the communication stop mode, the communication of the transceiver may be stopped by cutting off the power supply to the transceiver.

<4. Others>
In the second embodiment (FIG. 7) and the second example (FIG. 13) of the third embodiment described above, it is assumed that the number of channels (number of transmission lines) of the vehicle communication network is four, but the channels The number is not limited to this.

Further, the execution timing of the communication diagnosis process shown in FIG. 5 is when the ECU is started before the communication between the ECU of the own station and the ECU of the other station is established, or when the communication with the ECU of the other station is completed. It is desirable to carry out when the ECU is shut down, but it is possible to carry out even during normal control if requested.

In addition, the diagnosis target ECU is executed by raising the bit rate of diagnostic messages and the like only during communication diagnosis processing compared to during normal control, and after the diagnosis is completed, the bit rate is returned to that during communication with other ECUs. It is possible to shorten the diagnosis time.

Further, in the second embodiment (FIG. 7) and the second example (FIG. 13) of the third embodiment, all of the plurality of systems (channels) may be diagnosed, and the interruption circuit 105 of the plurality of systems may be diagnosed. It is possible to diagnose only the system which interrupted a part of communication by.

Furthermore, the present invention is not limited to the above-described embodiments, and it goes without saying that various other application examples and modifications can be taken as long as the gist of the present invention described in the claims is not deviated. ..

For example, the above-described embodiment describes the configuration of the electronic control device for a vehicle in detail and concretely in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the components described. It is also possible to replace a part of the configuration of one embodiment with a component of another embodiment. It is also possible to add components of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace other components with respect to a part of the configuration of each embodiment.

In addition, each of the above configurations, functions, processing units, and the like may be realized by hardware, for example, by designing a part or all of them with an integrated circuit. Further, each of the above-mentioned components, functions, and the like may be realized by software by the processor interpreting and executing a program that realizes each function. Information such as programs, tables, and files that realize each function can be placed in a semiconductor memory, a recording device such as an SSD (Solid State Drive), or a recording medium such as an IC card or an SD card.

Further, in the present specification, the processing steps for describing the time-series processing are not necessarily the processing performed in the time-series according to the described order, but are parallel or individual. It also includes processing executed in (for example, parallel processing or processing by an object).

1A to 1C ... ECU, 2 ... Microcomputer (microcomputer), 3 ... Submicrocomputer, 4 ... Transceiver, 5 ... Break circuit, 6 ... Communication switching circuit, 9,9a to 9d ... Transmission line, 20,20a to 20d ... Controller , 28 ... Communication circuit, 31 ... Diagnosis unit, 32 ... Diagnosis pre-processing unit, 33 ... Switching signal output unit, 34 ... Fail-safe processing unit, 101A-101I ... ECU, 102 ... Microcomputer, 103 ... Sub-microcomputer, 104a-104d ... Transceiver (ch1 to ch4), 105 ... Break circuit, 106a to 106d ... Communication switching circuit, 109 ... Internal transmission line, M, M1 to M4 ... Diagnostic message, S1, S2 ... Diagnostic relay signal, TX, TX1 to TX4 ... Transmit terminal, RX, RX1-RX4 ... Receive terminal

Claims (8)

An electronic control device for vehicles that controls the operation of a controlled object using a communication network for vehicles.
A transceiver that sends and receives data signals to and from the transmission lines that make up the vehicle communication network.
A microcomputer that sends and receives data signals to and from the transceiver,
A break circuit provided between the transceiver and the transmission line and switched to a communication cutoff state for cutting off communication with the transmission line or a communication connection state for enabling communication with the transmission line is provided.
The microcomputer is an electronic control device for a vehicle that diagnoses the transceiver by switching the interruption circuit to the communication interruption state. The microcomputer outputs a diagnostic signal to the break circuit via the transceiver when the break circuit is in the communication cut state.
The break circuit outputs a reply signal to the diagnostic signal input via the transceiver to the transceiver.
The electronic control device for a vehicle according to claim 1, wherein the microcomputer receives the reply signal via the transceiver and diagnoses the transceiver based on the result of comparing the diagnostic signal with the reply signal. The microcomputer outputs a switching signal instructing switching to the communication cutoff state or the communication connection state to the cutoff circuit.
According to claim 2, the cutoff circuit switches to the communication cutoff state or the communication connection state according to the switching signal, and outputs a state signal indicating the communication cutoff state or the communication connection state to the microcomputer. The vehicle electronic control device described. As the transceiver, a plurality of the transceivers provided corresponding to each of the plurality of transmission lines constituting the vehicle communication network are provided.
The break circuit connects a plurality of the transceivers to each other in a communication cutoff state, and receives the diagnostic signal from one of the transceivers in a state where the plurality of transceivers are connected. The electronic control device for a vehicle according to any one of claims 2 or 3, wherein the reply signal to the diagnostic signal is output to the transceiver that outputs the diagnostic signal and the other transceiver. The microcomputer outputs the diagnostic signal to the plurality of transceivers in order, and based on the reception status of the reply signal from the transceiver and the other transceivers that output the diagnostic signal, the plurality of the transceivers. The electronic control device for a vehicle according to claim 4 for diagnosis. The electronic control device for a vehicle according to claim 5, wherein the microcomputer diagnoses a plurality of the transceivers in order of resistance to failure. The break circuit switches between the plurality of transceivers and the plurality of transmission lines in the communication cutoff state or the communication connection state according to the switching signal, and in the communication cutoff state, the plurality of transceivers are mutually switched. Equipped with multiple communication switching circuits configured to connect communicably to
The microcomputer outputs the switching signal to the cutoff circuit to put the plurality of the communication switching circuits into the communication cutoff state, and in a state where the plurality of the transceivers are connected, one said one via one said transceiver. The diagnostic signal is output to the communication switching circuit,
The communication switching circuit that has received the diagnostic signal performs a process of transferring the diagnostic signal to the other communication switching circuit, and each of the plurality of communication switching circuits sends the reply signal to the diagnostic signal. , Output to each of the corresponding plurality of transceivers,
The invention according to any one of claims 4 to 6, wherein the microcomputer diagnoses a plurality of the transceivers based on the reception status of the transceiver that outputs the diagnostic signal and the reply signal from the other transceivers. Electronic control device for vehicles. The microcomputer includes a first microcomputer and a second microcomputer that monitors the first microcomputer.
The first microcomputer or the second microcomputer outputs the switching signal to the breaking circuit and receives the state signal from the breaking circuit.
The electronic control device for a vehicle according to claim 3, wherein the first microcomputer outputs the diagnostic signal and receives the reply signal to diagnose the transceiver.

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