JP2020129245A - Control device - Google Patents

Abstract

To provide a control device capable of diagnosing in a short time that signal output from a microcomputer has stopped when the microcomputer was reset.SOLUTION: The present invention includes: a microcomputer 2; a signal output unit 3 that is built in the microcomputer 2 and stops outputting signals when the microcomputer 2 is reset; a monitor unit 4 provided separately from the microcomputer 2 for monitoring an output state of the signal output unit 3; a latch unit 5 that is provided separately from the microcomputer 2 and holds a monitoring result of the monitor unit 4 and that is connected to the microcomputer 2 by a direct line; and a diagnostic unit 21 provided in the microcomputer 2 for diagnosing whether or not the output of the signal from the signal output unit 3 is stopped based on the monitor result held by the latch unit 5 after the microcomputer 2 is stopped and restarted by the reset process that resets the microcomputer 2.SELECTED DRAWING: Figure 1

Description

The present invention relates to a control device.

The control device includes a microcomputer (hereinafter also referred to as “microcomputer”) arranged on the substrate. Some control devices have a self-diagnosis function. For example, Japanese Unexamined Patent Application Publication No. 2018-36664 discloses an electronic control device that detects whether or not a reset command signal is output from a monitoring circuit to a microcomputer when an abnormality occurs. In this electronic control unit, the microcomputer diagnoses whether or not the reset command function of the monitoring circuit is normal. In addition, WO 2015/194407 describes an on-vehicle control device that has two ECUs and that the other ECU confirms communication interruption of one ECU.

JP, 2008-36664, A International Publication No. 2015/194407

Here, in the electronic control device, the microcomputer is not actually reset, and the diagnosis as to whether the signal output from the microcomputer is stopped is not executed. In the case where the on-vehicle control device has two ECUs, output stop diagnosis can be executed by the microcomputer of the ECU that has not been reset. However, when the diagnosis is executed between the two ECUs, both sides must match the signal transmission/reception timing. Further, the communication between the ECUs is the communication via the CAN outside the ECU case (outside the board), and the communication distance becomes large. That is, communication between ECUs takes time, and diagnosis time also becomes long. Therefore, the present inventor has set a new problem to enable the output stop diagnosis in a short time.

The present invention has been made in view of such circumstances, and provides a control device capable of diagnosing in a short time that signal output from a microcomputer is stopped when the microcomputer is reset. With the goal.

The control device of the present invention is provided with a microcomputer, a signal output unit incorporated in the microcomputer, which stops the output of a signal when the microcomputer is reset, and the signal output unit provided separately from the microcomputer. A monitor unit that monitors an output state of the output unit; and a latch unit that is provided separately from the microcomputer and that holds a monitor result of the monitor unit and that is connected to the microcomputer by a direct line. Whether the output of the signal of the signal output unit is stopped based on the monitor result held in the latch unit after the microcomputer is stopped and then restarted by the reset process for resetting the microcomputer And a diagnostic unit provided in the microcomputer.

According to the present invention, after the microcomputer (microcomputer) is stopped and the microcomputer is restarted, the diagnosis unit can confirm the monitoring result in which the output state of the signal output unit held by the latch unit is reflected. Thereby, the diagnosis unit can diagnose whether or not the output of the signal from the signal output unit is stopped by the reset of the microcomputer. Further, according to the present invention, since the latch unit and the microcomputer are connected by a straight line, the diagnosis unit provided in the microcomputer can immediately obtain the information of the latch unit. Therefore, it can be diagnosed in a short time that the signal output from the microcomputer is stopped when the microcomputer is reset.

It is a block diagram of the control apparatus of this embodiment. It is a flowchart which shows the flow of the self-diagnosis of the control apparatus of this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each drawing used for explanation is a conceptual drawing. The control device 1 of the present embodiment is an electronic control unit (ECU) provided in the vehicle. In a vehicle, a plurality of devices are connected to each other via a CAN 70. As an example, as shown in FIG. 1, the vehicle of the present embodiment is equipped with a control device 1 and a sub control device (sub ECU) 9. The sub control device 9 is configured to control the control target instead of the control device 1 when an abnormality occurs in the control device 1, for example. The sub control device 9 starts the control on behalf of the control device 1 on condition that the output from the control device 1 to the CAN 70 is stopped. The output of the control device 1 to the CAN 70 is stopped by resetting the microcomputer (microcomputer) 2 of the control device 1. The control device 1 of the present embodiment is configured such that the output stop can be self-diagnosed only by the control device 1 without using the sub-control device 9. Hereinafter, the configuration of the control device 1 will be specifically described.

The control device 1 includes a microcomputer 2, a signal output unit 3, a monitor unit 4, and a latch unit 5. The control device 1 further includes a conversion unit 6. The microcomputer 2 is arranged on the substrate 10. The microcomputer 2 includes a processor, memory and the like not shown. Details of the microcomputer 2 will be described later.

The signal output unit 3 is a part that is built in the microcomputer 2 and configured to stop the output of signals when the microcomputer 2 is reset. The signal output unit 3 is a unit in the microcomputer 2 that generates a signal corresponding to the communication network. The signal output unit 3 adds, for example, a predetermined header to the information and generates a signal. The signal output unit 3 of the present embodiment is a unit that executes communication with the CAN 70 in the microcomputer 2. The signal output unit 3 continuously outputs a signal during the operation of the microcomputer 2. The signal output from the signal output unit 3 is output to the outside of the control device 1 via the conversion unit 6.

The monitor unit 4 is a unit provided separately from the microcomputer 2 and monitors the output state of the signal output unit 3. The monitor unit 4 of the present embodiment is a monitor circuit provided on the substrate 10 and connected to a communication line 71 which is a path connecting the microcomputer 2 and the conversion unit 6. The monitor unit 4 turns on an output flag (for example, information held by the latch unit 5) when the signal output unit 3 is outputting a signal, and outputs an output flag when the signal output unit 3 is not outputting a signal, for example. Turn off. It can be said that the monitor unit 4 switches the ON/OFF information held (stored) in the latch unit 5 according to the output state of the signal output unit 3. The monitor unit 4 is a circuit that branches from the communication line 71 and transmits the communication status of the communication line 71 to the latch unit 5.

The latch part 5 is a part which is provided separately from the microcomputer 2 and holds the monitor result of the monitor part 4 and which is connected to the microcomputer 2 by a direct line. The latch section 5 is arranged on the circuit that constitutes the monitor section 4 on the substrate 10. It can be said that the monitor unit 4 has a latch function. The latch unit 5 of this embodiment is composed of a latch circuit. The latch unit 5 is connected to the second terminal 202, which is different from the first terminal 201 to which the communication line 71 is connected, of the terminals of the microcomputer 2 by a wire. It can be said that the microcomputer 2 and the latch section 5 are connected by a dedicated line. The direct line can be said to be a line that directly connects the two without a CAN. More specifically, the monitor unit 4 and the latch unit 5 are arranged on the monitor line 72 which is a path connecting the communication line 71 and the second terminal 202 of the microcomputer 2. In this embodiment, it can be said that the monitor line 72 constitutes the monitor unit 4 and the latch unit 5 is incorporated in the monitor unit 4. The monitor line 72 of this embodiment can be said to be a monitor and latch line. In this embodiment, the microcomputer 2, the monitor unit 4, and the latch unit 5 are provided on the same substrate 10.

The conversion unit 6 is a unit that is provided separately from the microcomputer 2 and that converts the signal output by the signal output unit 3 and outputs the signal to the outside of the substrate 10. The conversion unit 6 is a so-called driver and is arranged on the substrate 10. The conversion unit 6 converts the signal received from the signal output unit 3 via the communication line 71 into a signal capable of CAN communication and outputs the signal to the CAN 70.

(Self-diagnosis function)
The microcomputer 2 has a self-diagnosis function. Specifically, the microcomputer 2 includes a diagnosis unit 21 and an output stop unit 22. It can be said that the microcomputer 2 includes the arithmetic processing unit 20 having the diagnosis unit 21 and the output stopping unit 22, and the above-described signal output unit 3.

The microcomputer 2 executes a reset process for resetting the microcomputer 2 itself. In this reset process, for example, a reset request signal is output to an IC provided separately from the microcomputer 2 and the IC outputs a reset command signal to the microcomputer 2, or the microcomputer 2 itself resets without going through the IC. There are such things. Upon receiving the reset command signal, the microcomputer 2 shifts from the operating state to the stopped state and then restarts.

The diagnostic unit 21 diagnoses whether or not the signal output of the signal output unit 3 is stopped, based on the monitor result held in the latch unit 5, after the microcomputer 2 is restarted after being stopped by the reset process. To do. When the microcomputer 2 is restarted, the diagnosis unit 21 confirms the monitor result which is the information held by the latch unit 5, that is, the latest output state (ON/OFF of the output flag). The information held by the latch unit 5 is held in the flag-off state (for example, “0”) when the signal of the signal output unit 3 is stopped for a predetermined time, and is held in the flag-off state even if the signal of the signal output unit 3 is output thereafter. ..

When the signal output unit 3 is normal, resetting the microcomputer 2 causes the signal output unit 3 to stop outputting signals. In this case, no signal is input to the monitor unit 4, and the monitoring result is stopped from being output. As a result, the information held by the latch unit 5 also changes from the flag-on state (for example, “1”) to the flag-off state (for example, “0”). Therefore, the diagnosis unit 21 diagnoses that the output of the signal of the signal output unit 3 is stopped (that is, normal) when the held information of the latch unit 5 after the reset process is in the flag-off state. After the diagnosis, the information held in the latch section 5 is set to the flag-on state by the microcomputer 2.

On the other hand, when the signal output unit 3 is abnormal, the signal output of the signal output unit 3 does not stop even if the microcomputer 2 is reset. In this case, the state in which the signal is input to the monitor unit 4 continues, and the monitoring result is maintained while being output. That is, the information held by the latch unit 5 is also maintained in the flag-on state. Therefore, the diagnosis unit 21 diagnoses that the output of the signal of the signal output unit 3 is not stopped (that is, abnormal) when the information held in the latch unit 5 after the reset process is in the flag-on state.

When the diagnosis result is normal (output is stopped), the diagnosis unit 21 permits the output of the signal output unit 3 to be restarted. On the other hand, if the diagnosis result is abnormal (maintaining the output), the diagnosis unit 21 executes a warning process to notify the user that the diagnosis result is abnormal. The notification process is, for example, turning on a warning lamp or generating a warning sound. The self-diagnosis of the microcomputer 2 as described above is performed, for example, when the vehicle is inspected in a factory, when the vehicle is checked for start-up, or when the vehicle ignition is turned on.

The output stop unit 22 stops the output from the conversion unit 6 to the outside of the substrate 10 before the reset process is executed. For example, by stopping the output from the control device 1 to the CAN 70 when a self-diagnosis (for example, a start check) of the vehicle-mounted device is performed, the subsequent reset process of the microcomputer 2 may affect other devices. Can be prevented. It can be said that the output stop unit 22 executes the preparation for diagnosis. Since the microcomputer 2 can confirm the monitoring result by the latch unit 5 without going through the conversion unit 6, stopping the output of the conversion unit 6 does not affect the diagnosis.

As shown in FIG. 2, the flow of the self-diagnosis of the control device 1 includes an output stop step S1, a reset step S2, a confirmation step S3, and a diagnosis step S4. The output stop step S1 is a step in which the output stop unit 22 stops the output of the conversion unit 6. The reset step S2 is a step in which the microcomputer 2 executes a reset process. The confirmation step S3 is a step in which the diagnosis unit 21 confirms the monitoring result of the latch unit 5 after the microcomputer 2 is restarted. The diagnosing step S4 is a step in which the diagnosing unit 21 diagnoses the presence or absence of an abnormality based on the monitor result. The function of the output stopping unit 22 and the output stopping step S1 can be omitted in the execution of the self-diagnosis.

According to the present embodiment, even if the microcomputer 2 is stopped, after the microcomputer 2 is restarted, the diagnosis unit 21 confirms the monitoring result in which the output state of the signal output unit 3 held by the latch unit 5 is reflected. be able to. Thereby, the diagnosis unit 21 can diagnose whether or not the output of the signal of the signal output unit 3 is stopped by the reset of the microcomputer 2. That is, according to the present embodiment, only the control device 1 can diagnose that the signal output from the microcomputer 2 is stopped when the microcomputer 2 is reset.

Further, since the latch unit 5 and the microcomputer 2 are connected by the straight line, the diagnosis unit 21 can obtain the information of the latch unit 5 at an arbitrary timing without being restricted by other information transfer. Therefore, it is possible to shorten the communication time and eventually the diagnosis time. In the present embodiment, the microcomputer 2 is not affected by CAN communication to acquire the information of the latch unit 5. In addition, in the present embodiment, since the microcomputer 2, the monitor unit 4, and the latch unit 5 are arranged on the same board, it is not necessary to provide wiring such as a wire harness, and in addition to the improvement of the communication time shortening effect, the space is reduced. It is advantageous in terms of cost and cost. Further, in the present embodiment, since the latch section 5 is configured by the latch circuit (electronic circuit), the latch section 5 can be realized on the substrate 10 with a simple configuration, which is advantageous in terms of space and cost.

(Other)
The present invention is not limited to the above embodiment. For example, the latch unit 5 is not limited to the latch circuit and may be a non-volatile memory. Further, the latch portion 5 may be arranged outside the substrate 10. The monitor unit 4 may be the wiring itself that connects the communication line 71 and the microcomputer 2 via the latch unit 5, or may be an IC. Further, the control device 1 is not limited to a vehicle control device such as an engine ECU or a brake ECU, and may be applied to other systems.

DESCRIPTION OF SYMBOLS 1... Control device, 10... Board, 2... Microcomputer (microcomputer), 21... Diagnosis part, 22... Output stop part, 3... Signal output part, 4... Monitor part, 5... Latch part, 6... Conversion part, 71 …Communication line (route).

Claims (3)

A microcomputer,
A signal output unit incorporated in the microcomputer, which stops the output of the signal by resetting the microcomputer;
A monitor unit provided separately from the microcomputer, for monitoring the output state of the signal output unit,
A latch unit which is provided separately from the microcomputer and holds a monitor result of the monitor unit and which is connected to the microcomputer by a direct line;
Whether the output of the signal of the signal output unit is stopped based on the monitoring result held in the latch unit after the microcomputer is stopped and restarted by the reset process for resetting the microcomputer. A diagnostic unit provided in the microcomputer for diagnosing whether
A control device including. The control device according to claim 1, wherein the microcomputer, the monitor unit, and the latch unit are provided on the same substrate. A conversion unit that is provided separately from the microcomputer and that converts the signal output by the signal output unit and outputs the converted signal to the outside of the substrate on which the microcomputer is arranged;
The monitor unit is connected to a path connecting the microcomputer and the conversion unit,
The control device according to claim 1, wherein the microcomputer includes an output stop unit that stops the output from the conversion unit to the outside of the substrate before executing the reset process.

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