JP2022116376A - Control device and control method - Google Patents

Abstract

To diagnose failures of a communication cutoff function with certainty.SOLUTION: A control device 1 has: a CPU 7 that controls communication with another control device; a monitoring unit 11 that monitors the CPU 7; and a CAN driver 2 that has a transmission unit 4 transmitting a signal to the other control device on the basis of an instruction from the CPU 7, a reception unit 5 receiving a signal from the other control device and then transmitting a reception result to the CPU 7, and a mode control unit 6 switching between a normal mode of operating both the transmission unit 4 and the reception unit 5 and a reception mode of operating only the reception unit 5, on the basis of an instruction from the monitoring unit 11. The CPU 7, when the mode control unit 6 is switched to the reception mode, transmits a signal 16 only for diagnosis of the mode control unit 6 to the transmission unit 4 to make the transmission unit 4 transmit a signal, and performs diagnosis of the mode control unit 6 on the basis of whether or not the CPU 7 receives a signal based on the signal 16 only for diagnosis.SELECTED DRAWING: Figure 4

Description

The present invention relates to a control device and control method.

In recent years, for example, in a control device that is mounted on a vehicle and performs communication by CAN (Controller Area Network) with another control device that is also mounted on the vehicle, ISO 26262, which is an international functional safety standard for automobiles Due to the prescribed multiple safety requirement, it is required to take measures to block independent CAN transmission signals in the control. In response to this demand, a control device having a plurality of CAN controllers for one CAN bus is known (see Patent Document 1, for example).

In the technique disclosed in Patent Document 1, while one of the controllers operates in a normal mode in which transmission and reception is possible, the other controller operates in a reception mode in which only reception is possible. It is characterized in that the CAN communication is cut off by

JP-A-2017-95050

However, in order to satisfy the CAN communication blocking function in the control device disclosed in Patent Document 1, it is necessary to reliably confirm that the CAN communication blocking unit always operates normally.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a control device and a control method capable of reliably diagnosing a failure of a communication blocking function.

In order to solve the above problems, a control device according to one aspect of the present invention includes a control unit that controls communication with another control device, a monitoring unit that monitors the control unit, and a control unit that responds to instructions from the control unit. a transmitting unit that transmits a signal to another control device based on the instructions, a receiving unit that receives a signal from the other control device and transmits a reception result to the control unit, and a transmitting unit and a receiving unit based on instructions from the monitoring unit a transmission/reception unit having a mode control unit that switches between a normal mode in which all of the units operate and a reception mode in which only the reception unit operates; A diagnostic signal for the mode control unit is sent to the transmission unit to cause the transmission unit to transmit a signal, and the mode control unit is diagnosed based on whether or not the control unit receives a signal based on the diagnostic signal.

ADVANTAGE OF THE INVENTION According to this invention, the control apparatus and control method which can perform failure diagnosis of a communication interruption function reliably can be implement|achieved.

1 is a schematic configuration diagram showing a control device of Example 1. FIG. FIG. 4 is a time chart for explaining normal operation of the control device according to the first embodiment; FIG. 4 is a time chart for explaining the operation of the control device of the first embodiment when there is an abnormality; FIG. 2 is a schematic configuration diagram showing a control device during diagnosis according to the first embodiment; FIG. 4 is a time chart for explaining the operation during diagnosis of the control device of the first embodiment; FIG. 10 is a time chart for explaining the operation during diagnosis of the control device of the second embodiment; FIG. 11 is a time chart for explaining the operation during diagnosis of the control device of the third embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the embodiments described below do not limit the invention according to the claims, and that all of the elements described in the embodiments and their combinations are essential to the solution of the invention. is not limited.

FIG. 1 is a schematic configuration diagram showing the control device of Example 1. As shown in FIG.

In FIG. 1, a control device 1 of this embodiment is mounted on an automobile (vehicle) and forms a network capable of communicating with other control devices via a CAN bus 13 . The control device 1 has a CAN driver (transmitting/receiving unit) 2 , a CPU (control unit) 7 and a monitoring unit 11 .

The CPU 7 has a transmitter (TX) 9 that transmits the CAN message signal 8 and a receiver (RX) 10 that receives the CAN message signal, and controls communication with other control devices.

The CAN driver 2 has a communication control section 3 , a transmission section 4 , a reception section 5 and a mode control section 6 .

The communication control unit 3 causes the transmission unit 4 to transmit the CAN transmission signal 14 based on the CAN message signal 8 transmitted from the transmission unit (TX) 9 of the CPU 7 . A CAN transmission signal 14 transmitted from the transmitter 4 is transmitted to another control device via the CAN bus 13 and received by the receiver (RX) 10 via the receiver 5 . The receiver 5 also receives a CAN reception signal 15 transmitted from another control device connected to the CAN bus 13 and sends a CAN message signal to the receiver (RX) 10 of the CPU 7 .

The mode control unit 6 controls the transmission unit 4 and the reception unit 5 and operates the transmission unit 4 and the reception unit 5 in a normal mode in which signals can be transmitted and received, and in a normal mode in which only the reception unit 5 is operated to receive signals. It is possible to switch between a reception mode that operates only in the

The monitoring unit 11 monitors the CPU 7 and controls the mode switching operation by the mode control unit 6 based on the status signal. A CAN communication cutoff circuit 12 is composed of the mode control unit 6 and the monitoring unit 11 .

Next, the operation of the control device 1 of this embodiment configured as described above when the CAN communication cutoff circuit 12 is normal will be described with reference to FIGS. 1 and 2. FIG.

FIG. 2 is a time chart for explaining normal operation of the control device 1 of the first embodiment.

More specifically, in FIG. 2, 2-(a) is the transmission state of the CAN message signal 8 transmitted from the transmission unit (TX) 9, 2-(b) is the mode state of the mode control unit 6, 2-( c) shows the transmission state of the transmitter 4 in each state of 2-(b), and 2-(d) shows the reception state of the receiver (RX) 10. FIG.

During normal operation of the CPU 7, 2-(b) is in the normal mode, and the CAN message signal 8 transmitted from the transmitter (TX) 9 as shown in 2-(a) is transferred to 2-(c). It is transmitted from the transmitting section 4 as shown and received by the receiving section 5 as shown in 2-(d). In other words, CAN messages can be transmitted and received.

On the other hand, when the CPU 7 operates abnormally, as shown in 2-(b), the CAN communication cutoff circuit 12 is in the reception mode, and the CAN transmission signal 14 is transmitted from the transmission unit 4 as shown in 2-(c). However, as shown in 2-(d), the receiver 5 receives only the CAN received signal 15 transmitted from another control device. That is, when the CPU 7 is abnormal, only the transmission of the CAN transmission signal 14 is stopped, and the abnormal CAN transmission signal 14 is not transmitted to the CAN bus 13 .

Next, the operation of the CAN communication cutoff circuit 12 when there is an abnormality will be described with reference to FIGS. 1 and 3. FIG.

FIG. 3 is a time chart for explaining the operation of the control device 1 according to the first embodiment when there is an abnormality.

More specifically, 3-(a) is the transmission state of the CAN message signal 8 transmitted from the transmission unit (TX) 9, 3-(b) is the mode state of the mode control unit 6, and 3-(c) is the 3 -(b) indicates the transmission state of the transmitter 4, and 3-(d) indicates the reception state of the receiver (RX) .

During normal operation of the CPU 7, 3-(b) is in the normal mode, and as shown in 3-(a), the CAN message signal 8 transmitted from the transmitter (TX) 9 is shown in 3-(c). It is transmitted from the transmitter 4 as shown and received by the receiver 5 as shown in 3-(d). That is, the CAN message signal can be transmitted and received.

On the other hand, when the CPU 7 operates abnormally, as shown in 3-(b), the CAN communication cutoff circuit 12 is not in the reception mode, and the CAN transmission signal 14 is sent from the transmitter 4 as shown in 3-(c). is transmitted, and as shown in 3-(d), in the receiving unit 5, the CAN received signal 15 transmitted from the other control device and the CAN transmitted signal 14 transmitted from the transmitting unit 4 are transmitted to the receiving unit (RX) received at.

That is, when the CPU 7 is abnormal, there is a possibility that the CAN transmission signal 14 that may be abnormal data is transmitted to the CAN bus 13 . Therefore, normal diagnosis of the CAN communication cutoff circuit 12 is required so as not to cause the above-described phenomenon.

The procedure for diagnosing the CAN communication cutoff circuit 12 by the control device 1 according to the present embodiment, particularly the method of diagnosing immediately after the key is turned on, will be described with reference to FIGS. 4 and 5. FIG.

FIG. 4 is a schematic configuration diagram showing the control device 1 during diagnosis according to the first embodiment.

As shown in FIG. 4 , the CPU 7 of the control device at the time of diagnosis transmits a diagnosis-only signal 16 having a diagnosis-only ID of the CAN communication cutoff circuit 12 in addition to the CAN message signal 8 from the transmitter (TX) 9 .

FIG. 5 is a time chart for explaining the operation during diagnosis of the control device 1 of the first embodiment.

More specifically, 5-(a) is the drive state of the control device 1 when the vehicle is keyed on or keyed off, and 5-(b) is the CAN message signal 8 and diagnostic dedicated ID sent from the transmitter (TX) 9. 5-(c) is the mode state of the mode control unit 6, 5-(d) is the transmission state of the transmission unit 4 in each state of 5-(c), 5-(e ) indicates the reception state of the receiver (RX) 10 .

Generally, as shown in 5-(a), the control device 1 mounted on the vehicle performs a normal diagnosis of each function during the initial check period immediately after the key is turned on, and then enters a normal control state. During the initial check, communication with other control devices is generally not performed.

In this embodiment, as shown in 5-(c), the mode state of 5-(c) is set to the reception mode during the initial check period, and as shown in 5-(b), the diagnostic dedicated signal 16 is transmitted by the transmitter (TX ) from 9. As shown in 5-(d), the CAN transmission signal 14 is not transmitted from the transmitter 4 during the reception mode, and as shown in 5-(e), the receiver (RX) 10 is transmitted via the receiver 5. never receive.

In this state, the CPU 7 determines that the CAN communication cutoff circuit 12 is normal. If received, it is determined that the CAN communication cutoff circuit 12 is abnormal.

According to this embodiment configured as described above, the control device 1 includes the CPU 7 that controls communication with other control devices, the monitoring unit 11 that monitors the CPU 7, and based on instructions from the CPU 7, A transmitting unit 4 that transmits signals to other control devices, a receiving unit 5 that receives signals from other control devices and transmits reception results to the CPU 7, and a transmitting unit 4 and It has a CAN driver 2 having a mode control unit 6 for switching between a normal mode in which all of the receiving units 5 are operated and a reception mode in which only the receiving unit is operated. When the diagnostic signal 16 of the mode control unit 6 is transmitted to the transmission unit 4, the signal is transmitted by the transmission unit 4, and the mode control is performed based on whether the CPU 7 receives the signal based on the diagnostic signal 16. Diagnose part 6.

Therefore, according to this embodiment, it is possible to reliably diagnose the failure of the communication cutoff function.

More specifically, according to this embodiment, it is possible to diagnose the failure of the CAN communication cutoff circuit 12, which could not be detected in the prior art, for each driving cycle, and to reliably operate when the CAN communication cutoff is required. becomes possible.

In this embodiment, in order to diagnose the CAN communication cut-off circuit 12, the diagnosis dedicated signal 16 having the diagnosis dedicated ID is transmitted. If there is no influence, it is possible to transmit the diagnostic-dedicated signal with the ID used in normal control, and even in this case, the same effect can be obtained.

An embodiment in which the diagnostic procedure described in the first embodiment is performed during the self-shut period when the key is turned off will be described with reference to FIGS. 4 and 6. FIG.

FIG. 6 is a time chart for explaining the operation during diagnosis of the control device 1 of the second embodiment.

More specifically, 6-(a) is the driving state of the control device 1 when the vehicle is keyed on and keyed off, and 6-(b) is the CAN message signal 8 and diagnostic dedicated ID sent from the transmitter (TX) 9. 6-(c) is the mode state of the mode controller 6, 6-(d) is the transmission state of the transmitter 4 in each state of 6-(c), 6-(e ) indicates the reception state of the receiver (RX) 10 .

In general, as shown in 6-(a), the control device 1 mounted on the vehicle provides a self-shut period when the key is turned off, and each function state at the end of the driving cycle is stored in an electronic component having a memory such as a CPU 7. to be stored for the next driving cycle.

In this embodiment, as shown in 6-(c), the mode state of 6-(c) is set to the receive mode during the self-shutdown period, and as shown in 6-(b), the diagnostic dedicated signal 16 is transmitted from the transmitter ( TX) 9.

As shown in 6-(d), the CAN message signal is not transmitted from the transmitter 4 during the reception mode, and is received by the receiver (RX) 10 via the receiver 5 as shown in 6-(e). never do.

In this state, the CPU 7 determines that the CAN communication cutoff circuit 12 is normal. If received, it is determined that the CAN communication cutoff circuit 12 is abnormal.

Therefore, this embodiment can also obtain the same effect as the first embodiment described above.

In this embodiment, since this diagnosis is performed during the self-shut period, that is, when the key is turned off, there is no operational influence on a plurality of control devices connected to the common CAN bus 13 as in the first embodiment, and CAN communication is interrupted. Diagnosis of the circuit 12 becomes possible.

An embodiment in which the diagnostic procedure described in Embodiment 1 is performed when the CAN bus 13 is not used will be described with reference to FIGS. 4 and 7. FIG.

FIG. 7 is a time chart for explaining the operation during diagnosis of the control device 1 of the third embodiment.

More specifically, 7-(a) is the transmission state of the CAN message signal 8 transmitted from the transmission unit (TX) 9, 7-(b) is the mode state of the mode control unit 6, 7-(c) is 7 -(b) indicates the transmission state of the transmitter 4, and 7-(d) indicates the reception state of the receiver (RX) .

In this embodiment, in the CAN bus 13 which mainly communicates by periodic transmission, diagnosis of the CAN communication cutoff circuit 12 is performed during periodic transmission, that is, when the CAN bus 13 is not in use.

As shown in 7-(a), a diagnosis period is provided when the CAN bus 13 is not used during normal control, and as shown in 7-(b), the mode control unit 6 is set to receive mode during normal control, As shown in 7-(a), the diagnosis-only signal 16 is transmitted from the transmitter (TX) 9. FIG.

As shown in 7-(c), the CAN transmission signal 14 is not transmitted from the transmitter 4 during the reception mode, and as shown in 7-(d), the receiver (RX) 10 is transmitted via the receiver 5. never receive.

In this state, the CPU 7 determines that the CAN communication cutoff circuit 12 is normal. If received, it is determined that the CAN communication cutoff circuit 12 is abnormal.
Therefore, this embodiment can also obtain the same effect as the first embodiment described above.

In addition, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. In addition, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration.

Further, the control lines and information lines indicate those considered necessary for explanation, and not all control lines and information lines are necessarily indicated on the product. In practice, it may be considered that almost all configurations are interconnected.

REFERENCE SIGNS LIST 1 control device 2 CAN driver (transmitting/receiving unit) 3 communication control unit 4 transmitting unit 5 receiving unit 6 mode control unit 7 CPU (control unit) 8 CAN message signal 9 transmitting unit (TX) 10 ... Reception unit (RX) 11 ... Monitoring unit 12 ... CAN communication cutoff circuit 13 ... CAN bus 14 ... CAN transmission signal 15 ... CAN reception signal 16 ... Diagnosis dedicated signal (diagnosis signal)

Claims (8)

a control unit that controls communication with other control devices;
a monitoring unit that monitors the control unit;
a transmitting unit that transmits a signal to the other control device based on an instruction from the control unit; a receiving unit that receives the signal from the other control device and transmits a reception result to the control unit; a transmission/reception unit having a mode control unit that switches between a normal mode in which both the transmission unit and the reception unit operate and a reception mode in which only the reception unit operates based on an instruction from a monitoring unit;
When the mode control unit is switched to the reception mode, the control unit transmits a diagnostic signal of the mode control unit to the transmission unit to cause the transmission unit to transmit the signal. A control device that diagnoses the mode control unit based on whether or not the control unit receives the signal based on the signal. 2. The control device according to claim 1, wherein the control unit determines that the mode control unit is normal when the control unit does not receive the signal based on the diagnostic signal. 2. The control device according to claim 1, wherein the control unit determines that the mode control unit is abnormal when the control unit receives the signal based on the diagnostic signal. the transmission unit transmits the signal via a communication bus;
the receiving unit receives the signal from the communication bus;
2. The control device according to claim 1, wherein the control unit sends out the diagnostic signal to the transmission unit at a timing when the communication bus is not in use. The control device is mounted on a vehicle,
5. The control device according to claim 4, wherein the control unit sends the diagnostic signal to the transmission unit when the vehicle is key-on. The control device is mounted on a vehicle,
5. The control device according to claim 4, wherein the control unit sends the diagnostic signal to the transmission unit when the vehicle is key-off. 2. The control device according to claim 1, wherein said diagnostic signal is a signal used for controlling communication with said other control device. a control unit that controls communication with other control devices;
a monitoring unit that monitors the control unit;
a transmitting unit that transmits a signal to the other control device based on an instruction from the control unit; a receiving unit that receives the signal from the other control device and transmits a reception result to the control unit; A control method by a control device having a transmitting/receiving section having a mode control section that switches between a normal mode in which both the transmitting section and the receiving section operate and a receiving mode in which only the receiving section operates based on an instruction from a monitoring section. and
After switching the mode control unit to the reception mode, causing the control unit to transmit a diagnostic signal of the mode control unit to the transmission unit, causing the transmission unit to transmit the signal, and A control method, comprising diagnosing the mode control unit based on whether the signal is received by the control unit.

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