JP3651273B2 - Self-shutoff diagnostic device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in which it is possible to determine whether or not self-shutoff is actually executed in a vehicle control system having a self-shutoff function.
[0002]
[Prior art]
In the vehicle control system, for example, as shown in FIG. 5, power is supplied from the power source 2 to the control unit 1 via the ignition key switch 1. On the other hand, even after the ignition switch 1 is turned off, the power supply from the power source 2 to the control unit 1 is maintained via the self-shutoff relay 4 for a predetermined time. Various self-shutoff processes are executed during the self-shutoff in which the power supply is maintained even when the ignition key switch 1 is turned off.
[0003]
In the self-shutoff process, the self-shutoff process means 6 provided in the CPU 5 performs various inspections that cannot be performed while the vehicle is running (while the ignition key switch 1 is ON). For example, the elasticity check of the return spring of the electronically controlled throttle and the zero point calibration of the stepping motor cannot be performed during the operation of the vehicle, and thus are performed in the self-shutoff process. The watchdog timer 7 that monitors the CPU 5 during operation of the vehicle is diagnosed as to whether an abnormality has occurred in the self-shutoff process.
[0004]
When such a self-shutoff is executed for a predetermined time, a signal is sent from the control unit 1 to the self-shutoff relay 4, and the self-shutoff relay 4 is disconnected. As a result, the power supply from the power source 2 to the control unit 1 is stopped, and the self-shutoff ends.
[0005]
[Problems to be solved by the invention]
However, since the conventional vehicle control device does not have a function for determining whether or not such a self-shutoff is actually executed, for example, the self-shutoff relay 4 fails and the self-shutoff is performed. Even if no power supply was made, this could not be immediately known.
[0006]
The present invention has been made paying attention to such problems, and in a vehicle control system having a self-shutoff function, it is possible to determine whether or not self-shutoff is actually executed. It is an object to provide a function diagnostic apparatus.
[0007]
[Means for Solving the Problems]
In the first aspect of the present invention, power is supplied to the control unit via the ignition key switch, and power is supplied to the control unit for a predetermined time to execute self-shutoff after the ignition key switch is turned off. In a vehicle control system having an off-power supply means, a self-shutoff function diagnostic device includes a count means for holding a count value even after the end of power supply, and the count means each time the ignition key switch is turned on. Count-up means for counting up the count value of the counter, count-clearing means for clearing the count value of the count means during the self-shutoff, and monitoring the count value of the count means. Become Abnormal shut-off function and a self shut-off function determining means determines that occurs when.
[0008]
In the second invention, the predetermined value of the count value is a multiple count value of 3 counts or more.
[0009]
In a third aspect of the present invention, there is provided notification means for notifying the occurrence of an abnormality when it is determined that an abnormality has occurred in the self-shutoff function.
[0010]
Operation and effect of the invention
In the first invention, when the ignition key switch 1 is turned on and power supply to the control unit 1 is started, the count value of the counting means is counted up by the counting up means. When there is no abnormality in the self-shutoff function (for example, the self-shutoff power supply means) and the self-shutoff is executed after the ignition key switch 1 is turned off, the counter value of the counting means each time the self-shutoff is performed. Is cleared, the counter value does not exceed a predetermined value, and the self-shutoff function determination means does not determine the occurrence of an abnormality. On the other hand, when an abnormality occurs in the self-shutoff function and the self-shutoff is not executed, the counter value of the counting means is not cleared, and the count value is incremented every time the ignition key switch is turned on. When the value becomes equal to or greater than a predetermined value, the occurrence of abnormality is determined by the self-shutoff function determining means. In this way, the occurrence of an abnormality in which self-shutoff is not executed is reliably detected.
[0011]
In the second invention, the predetermined value for determining the occurrence of abnormality is a multiple count value of 3 counts or more. Therefore, if the count is mistakenly counted up by 1 count due to noise or the like, the count value Therefore, the occurrence of abnormality is not determined by the self-shutoff function determining means. Therefore, the determination of the occurrence of abnormality by the diagnostic device is performed correctly.
[0012]
In the third invention, since the detection of the abnormality occurrence by the diagnostic device is immediately notified by the notification means, it is possible to take a countermeasure quickly.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0014]
FIG. 1 shows a configuration of a vehicle control system according to an embodiment of the present invention.
[0015]
The basic configuration of this control system is the same as that of the conventional control system shown in FIG. 4, for example. That is, the ignition key switch 1, the power source 2, the control unit 3, the self-shut-off relay 4, and the self-shut-off processing means 6 of the CPU 5 have the same configuration as the conventional example shown in FIG. Omitted.
[0016]
The control device of the present embodiment includes a diagnostic counter 8 and a self-shutoff function determination means 9 in the CPU 5 as a characteristic configuration. In the CPU 5, the diagnosis counter 8 and the self-shutoff function determination means 9 diagnose the self-shutoff function, that is, whether or not the self-shutoff is actually executed.
[0017]
The diagnosis counter 8 is incremented by 1 when the ignition key switch 1 is turned from OFF to ON. On the other hand, when the ignition key switch 1 is turned from ON to OFF and self-shutoff is executed, the count is cleared during the self-shutoff (for example, following various self-shutoff processes).
[0018]
The count value of the diagnostic counter 8 is held as it is even after the power supply from the power source 2 is completed. For this reason, for example, when the CPU 5 includes the diagnostic counter 8 as in the present embodiment, the counter value is backed up in a memory (not shown), and is stored when power is supplied to the CPU 5 again. Read the counted value. Further, the diagnostic counter 8 may be provided in a memory external to the CPU 5.
[0019]
The self-shutoff function determination means 9 monitors the count value of the diagnostic counter 8 and determines that an abnormality has occurred in the self-shutoff function when this count value exceeds a predetermined value (for example, 5 counts). . If the self-shutoff function determination means 9 determines that an abnormality has occurred in the self-shutoff function, the occurrence of this abnormality is notified, for example, by turning on the warning lamp 10.
[0020]
FIG. 2 is a flowchart showing a control procedure for diagnosis of the self-shutoff function in the CPU 5.
[0021]
In step S1, it is determined whether or not the power is being turned on for the first time, that is, whether or not the control routine is a control routine that was first executed by turning the ignition key switch 1 from OFF to ON.
[0022]
If it is determined in step S1 that the power is first turned on, the process proceeds to step S2, the diagnostic counter 8 is incremented by 1, and the process proceeds to step S3. On the other hand, if it is determined in step S1 that the power is not turned on for the first time, the process directly proceeds to step S3.
[0023]
In step S3, the self-shutoff function determination means 9 determines whether or not the diagnostic counter 8 has reached a predetermined value (for example, 5 counts) or more.
[0024]
If it is determined in step S3 that the diagnostic counter 8 is greater than or equal to the predetermined value, the process proceeds to step S4, and the self-shutoff function determining means 9 determines that the self-shutoff function is normal and the process proceeds to step S6. move on.
[0025]
On the other hand, if it is determined in step S3 that the diagnostic counter 8 is not greater than or equal to the predetermined value, the process proceeds to step S5, and the self-shutoff function determination means 9 determines that there is an abnormality in the self-shutoff function, and step S6. Proceed to
[0026]
In step S6, it is determined whether or not the ignition key switch 1 is turned off. If the ignition key switch 1 is not turned off, the routine is terminated as it is.
[0027]
On the other hand, if it is determined in step S6 that the ignition key switch 1 is turned off, the process proceeds to step S7, and the self-shutoff processing means 6 executes the self-shutoff process. Further, in the subsequent step S8, the diagnostic counter 8 is cleared.
[0028]
For example, when the self-shut-off relay 4 fails and an abnormality that the self-shut-off is not performed occurs, that is, the power supply from the power source 2 to the control unit 1 (CPU 3) is interrupted when the ignition key switch 1 is turned off. When an abnormality occurs, the processing executed after the ignition key switch 1 is turned off, that is, the self-shutoff processing in step S7 and the clear processing of the diagnostic counter 8 in step S8 are not executed. Therefore, in this case, the value of the diagnostic counter 8 is counted up to 2 counts or more every time the ignition key switch 1 is turned off.
[0029]
Next, the operation will be described.
[0030]
3 and 4 are timing charts showing the relationship between ON / OFF of the ignition key switch 1, power supply to the control unit 1, and the count value of the diagnostic counter 8 in the present embodiment.
[0031]
The timing chart of FIG. 3 shows a case where there is no abnormality in the self-shutoff function. As shown in the upper part of the figure, when the ignition key switch 1 is turned on, as shown in the middle part of the figure, the control unit 1 Power supply to is started. Then, as shown in the lower part of the figure, the value of the diagnostic counter 8 is counted up to 1 count following the start of the power supply.
[0032]
Thereafter, when the ignition key switch 1 is turned off, self-shutoff (indicated as “S / S / OFF” in the figure) is performed in which power is supplied to the control unit 1 for a predetermined time. During this self-shutoff, the value of the diagnostic counter 8 is cleared to zero.
[0033]
On the other hand, the timing chart of FIG. 4 shows a case where an abnormality occurs in the self-shutoff function and the self-shutoff is not performed. As shown in the drawing, in this case, since the power supply to the control unit 1 is stopped simultaneously with the ignition key switch 1 being turned off, the self-shutoff is not executed. Therefore, the diagnosis counter 8 is not cleared to zero, and the count value of the diagnosis counter 8 is incremented every time the ignition key switch 1 is turned on.
[0034]
The count value of the diagnostic counter 8 is monitored by the self-shutoff function determination means 9 to determine whether or not the count value has reached a predetermined value (for example, 5 counts). If the count value of the diagnostic counter 8 exceeds a predetermined value, the self-shutoff function determination means 9 determines that an abnormality has occurred in the self-shutoff function, and the CPU 5 turns on the warning lamp 10 to generate an abnormality. Is notified.
[0035]
In this case, the predetermined value for determining the abnormality is set to a plurality of count values of 3 counts or more (for example, 5 counts), for example, when the diagnostic counter 8 is only counted up due to noise or the like. It can be determined that an abnormality has occurred in the shut-off function. That is, the self-shutoff function determination means 9 continues for a plurality of times that the self-shutoff is not executed when the ignition key switch 1 is OFF, and when the count value becomes 3 counts or more, the occurrence of abnormality is determined for the first time. When the diagnostic counter 8 is only counted up by 1 count due to noise or the like, it is not determined that an abnormality has occurred.
[0036]
As described above, according to the present invention, a failure in which self-shutoff is not performed is reliably detected. Further, the failure detection is immediately notified by the warning lamp 10 or the like, and the failure can be immediately dealt with.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an embodiment of the present invention.
FIG. 2 is a flowchart showing a control procedure for self-shutoff function diagnosis.
FIG. 3 is also a timing chart showing ON / OFF of an ignition key switch, power supply to a control unit, and count timing of a diagnostic counter.
FIG. 4 is also a timing chart showing ON / OFF of an ignition key switch, power supply to a control unit, and count timing of a diagnostic counter.
FIG. 5 is a block diagram showing a conventional example.
[Explanation of symbols]
1 Ignition key switch 2 Power supply 3 Control unit 4 Self shut-off relay 5 CPU
6 Self-shut-off processing means 7 Watchdog timer 8 Diagnostic counter 9 Self-shut-off function 10 Warning light

Claims (3)

Self-shutoff power supply means for supplying power to the control unit via the ignition key switch and supplying power to the control unit for a predetermined time to execute self-shutoff after the ignition key switch is turned off In a vehicle control system,
Counting means for holding the count value even after the end of power supply;
Count-up means for counting up the count value of the count means each time the ignition key switch is turned ON;
Count clear means for clearing the count value of the count means during the self-shutoff;
A self-shutoff function determination unit that monitors the count value of the count unit and determines that an abnormality has occurred in the self-shutoff function when the count value exceeds a predetermined value;
A diagnostic apparatus for self-shutoff function. 2. The diagnostic device for self-shutoff function according to claim 1, wherein the predetermined value of the count value is a plurality of count values of 3 counts or more. The self-shutoff function according to claim 1 or 2, further comprising an informing means for informing the occurrence of an abnormality when it is determined that an abnormality has occurred in the self-shutoff function. Diagnostic device.

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