JPWO2017010490A1 - Low voltage abnormality determination device and low voltage abnormality determination method - Google Patents

Abstract

The transmission controller determines that the first voltage is higher than a first threshold value for determining that the first switch is normal, and that the second voltage is normal for both the first switch and the second switch. A third threshold value that is between the second threshold value and the lowest voltage that can guarantee the operation of the device and that determines that the difference between the first voltage and the second voltage is normal for the second switch If the device is smaller, the device self-diagnosis is executed. If the device does not operate normally in the self-diagnosis, it is determined that a low voltage abnormality in which the input voltage to the device is insufficient has occurred.

Description

  The present invention relates to a technique for determining a low voltage abnormality in a power supply circuit.

  The malfunction of devices such as solenoid valves, sensors, and actuators is due not only to device failure but also due to insufficient voltage input to these devices due to voltage drops in switches provided in the middle of the power line (low voltage abnormality). Also happens.

  For this reason, the engine controller, transmission controller, etc. mounted on the vehicle monitor the low voltage abnormality, and if it is determined that the low voltage abnormality is present, the low voltage that stops the operation by stopping energization of all devices. Performs failure-safe fail-safe control.

  The normal operation of each device cannot be guaranteed when the low voltage is abnormal, but even if all devices stop operating, the engine and transmission will settle down (fixed) to a specific state where the vehicle can run. Etc. are designed in advance, and when the low voltage abnormality occurs, the above-described fail safe control corresponding to the low voltage abnormality is performed, so that the vehicle can be maintained at least in a travelable state.

  The low voltage abnormality can be determined based on the measured voltage by measuring the voltage in the middle of the power line connecting the power source and the device.

  However, if there are a plurality of switches (mechanical relays, semiconductor relays, etc.) in the middle of the power supply line, it may be difficult to determine a low voltage abnormality depending on the measured voltage.

  Then, fail-safe control (for example, JP2005) that erroneously determines that a specific device has failed despite a low voltage abnormality and realizes a state in which the vehicle can travel without using the device. If the control disclosed in US Pat. No. 3,447,41A) is executed, the control is based on the assumption that devices other than the device are operating normally. Therefore, other devices continue to operate due to a low voltage abnormality. If a failure occurs, the power performance of the vehicle may deteriorate and the shift quality may deteriorate.

  The present invention has been made in view of the above technical problem, and enables a low-voltage abnormality to be determined with higher accuracy in a power supply circuit having a plurality of switches in the middle of a power supply line connecting a power supply and a device. For the purpose.

  According to an aspect of the present invention, a power source, a power line connecting the power source and the device, a first switch provided in the middle of the power line, and the first switch in the middle of the power line There is provided a low-voltage abnormality determination device that determines a low-voltage abnormality in which the input voltage to the device is insufficient in a power supply circuit including a second switch provided closer to the device than the switch.

  The low voltage abnormality determination device includes a first voltage that is a voltage between the first switch and the second switch, and a second voltage that is a voltage between the second switch and the device. And the first voltage is higher than a first threshold value for determining that the first switch is normal, and the second voltage is normal for both the first switch and the second switch. A second threshold value that is determined to be present and a minimum voltage that can guarantee the operation of the device, and a difference between the first voltage and the second voltage is normal in the second switch. Is smaller than the third threshold value, the device performs a self-diagnosis. If the device does not operate normally in the self-diagnosis, it is determined that the low voltage abnormality has occurred.

  According to another aspect of the present invention, a low voltage abnormality determination method corresponding to this is provided.

  The second voltage is higher than the first threshold value for determining that the first switch is normal, and the second voltage is determined to be normal for both the first switch and the second switch. And the minimum voltage that can guarantee the operation of the device, and the difference between the first voltage and the second voltage is smaller than the third threshold value for determining that the second switch is normal. Whether the low voltage abnormality has occurred cannot be determined from only the first voltage and the second voltage.

  According to these aspects, in such a case, device self-diagnosis is also executed. If any device does not operate normally as a result of self-diagnosis, it is considered that the malfunction is caused by a low voltage. Therefore, the low voltage is low only from the first voltage and the second voltage. Even if it is impossible to determine whether a voltage abnormality has occurred, it can be determined that a low voltage abnormality has occurred.

FIG. 1 is a diagram showing an example in which a low voltage abnormality determination device according to an embodiment of the present invention is applied to a transmission controller. FIG. 2 is a diagram for explaining the content of the low-voltage abnormality determination process. FIG. 3 is a flowchart showing the content of the low voltage abnormality determination process.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows an example in which a low voltage abnormality determination device according to an embodiment of the present invention is applied to a transmission controller 100.

  The transmission controller 100 uses the first switch 12 and the second switch 13 in addition to the function of controlling the device 11 necessary for causing the transmission 200 to perform a predetermined operation (shifting, lockup, etc.). A function for turning on / off the power supply to the device, and a low voltage abnormality determination function for determining a low voltage abnormality in which the input voltage to the device 11 is insufficient.

  The transmission controller 100 includes a main CPU 14 and a sub CPU 15. Main processing related to the control of the transmission 200 is executed by the main CPU 14. The sub CPU 15 monitors the operation of the main CPU 14, and when the internal calculation value of the main CPU 14 becomes an abnormal value, the second switch 13 is switched from ON to OFF, and the device 11 is switched from the power source 20 (battery or alternator). Forcibly cut off the power supply to

  The device 11 is operated by a voltage supplied from the power supply 20. The device 11 includes a solenoid valve that controls the hydraulic pressure supplied to each part of the transmission 200, and the hydraulic pressure and oil supplied to each part of the transmission 200. Sensors that detect temperature, oil pumps that are driven during idle stop, etc., and generate hydraulic pressure are included.

  The power supply 20 and the device 11 are connected by a power supply line 30. The first switch 12 and the second switch 13 are provided in the middle of the power supply line 30, and the second switch 13 is provided closer to the device 11 than the first switch 12.

  The first switch 12 is, for example, a mechanical relay, and is disposed outside the transmission controller 100. When the ignition switch 31 is turned on and the power supply from the power supply 20 to the main CPU 14 is started, a current flows from the main CPU 14 to the first switch 12 via the instruction line 32, and the first switch 12 is turned off. It can be switched on. Thereby, when the ignition switch 31 is OFF, the power source 20 and the device 11 are completely cut off, and the dark current when the ignition switch 31 is OFF can be reduced.

  The second switch 13 is a semiconductor relay, for example, and is disposed inside the transmission controller 100. When the sub CPU 15 determines that the internal calculation value of the main CPU 14 has become an abnormal value, the sub CPU 15 switches the second switch 13 from ON to OFF. This prevents the transmission 200 from being controlled based on the abnormal value.

  Further, voltages V1 and V2 at the positions of the power supply line 30 between the first switch 12 and the second switch 13 and the position between the second switch 13 and the device 11 are detected. A first voltage sensor 41 and a second voltage sensor 42 are provided.

  The transmission controller 100 determines the low voltage abnormality in which the input voltage to the device 11 is insufficient based on the detected voltages V1 and V2 and, if necessary, the result of the self-diagnosis of the device 11.

  If it is determined that a low voltage abnormality has occurred, the operation of all the devices 11 cannot be guaranteed, that is, the devices 11 may randomly malfunction. Execute fail-safe control for low voltage abnormality to be stopped.

  The transmission 200 is designed in advance so as to settle (fix) in a specific state in which the vehicle can run when the operation of all the devices 11 is stopped, for example, in a state where the gear ratio is fixed to the specific gear ratio. If so, the vehicle can be maintained at least in a state where it can run by executing the fail-safe control corresponding to the low voltage abnormality.

  Further, the transmission controller 100 also determines the failure of the device 11, and if it is determined that any of the devices 11 has failed, the device can be driven without using the device 11. Device failure handling fail-safe control for controlling devices 11 other than 11 is executed. For example, if the electric oil pump is out of order, idle stop is prohibited.

  FIG. 2 shows the voltage V1 detected by the first voltage sensor 41 (hereinafter referred to as the first voltage V1) and the voltage V2 detected by the second voltage sensor 42 (hereinafter referred to as the second voltage V2). FIG. 4 is a map showing how the transmission controller 100 determines a low voltage abnormality. FIG.

  According to this, when the first voltage V1 is lower than the first threshold V1th at which the first switch 12 determines that the first switch 12 is normal (the voltage drop is within an allowable range), the first voltage V1 is It is determined that a low voltage abnormality due to the failure of the switch 12 has occurred.

  When the second voltage V2 is higher than the second threshold value V2th for determining that both the first switch 12 and the second switch 13 are normal, it is determined that no low voltage abnormality has occurred. Furthermore, self-diagnosis of each device 11 is performed, and if there is a device 11 that does not operate normally by self-diagnosis, it is determined that the device 11 has failed.

  When the difference ΔV between the first voltage V1 and the second voltage V2, that is, the voltage drop in the second switch 13 exceeds the third threshold value ΔVth (allowable range), the second switch 13 It is determined that a low voltage abnormality due to the failure of the product has occurred.

  Also, when the second voltage V2 is lower than the minimum voltage Vmin that can guarantee the operation of the device 11, it is determined that a low voltage abnormality has occurred because the voltage necessary for the device 11 is not actually supplied.

  The first voltage V1 is higher than the first threshold value V1th, the second voltage V2 is lower than the second threshold value V2th, and the difference ΔV between the first voltage V1 and the second voltage V2 is the third threshold value. When it is smaller than ΔVth and the second voltage V2 is larger than the minimum voltage Vmin that can guarantee the operation of the device 11 (hatched region in FIG. 2), the first voltage V1 and the second voltage V2 alone are low. It cannot be determined whether a voltage abnormality has occurred.

  For this reason, when the relationship between the first voltage V1 and the second voltage V2 is included in the hatching region of FIG. 2, the transmission controller 100 also performs self-diagnosis of the device 11, As a result, if any one of the devices 11 does not operate normally, it is determined that the device does not operate normally due to a low voltage, and it is determined that a low voltage abnormality has occurred.

  FIG. 3 is a flowchart of the low voltage abnormality determination process, which is executed in the transmission controller 100.

  According to this, in step S1, the transmission controller 100 compares the second voltage V2 with a second threshold value V2th that determines that both the first switch 12 and the second switch 13 are normal. If the second voltage V2 is lower than the second threshold value V2th, there is a possibility that a low voltage abnormality has occurred. Therefore, the transmission controller 100 advances the processing to step S2 and starts determining the low voltage abnormality. .

  In step S2, the transmission controller 100 compares the first voltage V1 with a first threshold value V1th that determines that the first switch 12 is normal (the voltage drop is within an allowable range). If the first voltage V1 is lower than the first threshold value V1th, it is considered that a low voltage abnormality has occurred due to the failure of the first switch 12, and therefore the transmission controller 100 proceeds to step S7 to reduce the low voltage. It is determined that a voltage abnormality has occurred.

  If the first voltage V1 is higher than the first threshold value V1th, the first switch 12 is considered to be normal, but if the determination result in step S1 is taken into account, the second switch 13 may fail. Since there is a possibility that a low voltage abnormality has occurred, the transmission controller 100 proceeds with the process to step S3 and further verifies whether or not there is a low voltage abnormality.

  In step S3, the transmission controller 100 compares the difference ΔV between the first voltage V1 and the second voltage V2, that is, the voltage drop in the second switch 13, with a third threshold value ΔVth (allowable range). . When the difference ΔV between the first voltage V1 and the second voltage V2 is smaller than the third threshold value ΔVth, it is considered that a low voltage abnormality has occurred due to the failure of the second switch 13, so that the transmission controller 100 advances the process to step S7, and determines that a low voltage abnormality has occurred.

  If the difference ΔV between the first voltage V1 and the second voltage V2 is smaller than the third threshold value ΔVth, the second switch 13 is considered to be normal, but the voltage drop in the first switch 12 and Since there is a possibility that the input voltage to the device 11 is insufficient due to the sum of the voltage drops in the second switch 13, the transmission controller 100 proceeds with the process to step S4 to check whether there is a low voltage abnormality. We will examine further about.

  In step S4, the transmission controller 100 compares the second voltage V2 with the minimum voltage Vmin that can guarantee the operation of the device 11. If the second voltage V2 is lower than the minimum voltage Vmin that can guarantee the operation of the device 11, the input voltage of the device 11 is just insufficient, so the transmission controller 100 proceeds with the process to step S7. It is determined that a low voltage abnormality has occurred.

  When the second voltage V2 is higher than the minimum voltage Vmin that can guarantee the operation of the device 11, the input voltage is theoretically not insufficient. However, since the supplied power is not sufficient, the input voltage to the device 11 may actually be insufficient depending on manufacturing variations, deterioration with time, and operating environment. For this reason, in this case, the transmission controller 100 performs a self-diagnosis of the device 11 to actually operate the device 11, and as a result, determines whether a low voltage abnormality has occurred based on whether the device 11 has operated correctly. To do.

  Specifically, the transmission controller 100 proceeds with the process to step S5, and performs self-diagnosis of each device 11. In the self-diagnosis, for example, a predetermined control signal is sent to each device 11, and it is determined whether each device 11 has normally operated based on a change in state (change in output signal) of each device 11.

  Then, the transmission controller 100 determines in step S6 whether each device 11 has operated normally, and if it has determined that any device 11 has not operated normally, it has not operated normally due to a lack of input voltage. Therefore, the process proceeds to step S7, and it is determined that a low voltage abnormality has occurred.

  If any device 11 operates normally as a result of self-diagnosis, it cannot be said that a low voltage abnormality has occurred. Therefore, the transmission controller 100 returns the process to step S1 and performs the low voltage abnormality determination process again. Run.

  If it is determined in step S7 that a low voltage abnormality has occurred, the transmission controller 100 proceeds to step S8, performs a low voltage abnormality corresponding failsafe control to stop the operation of all the devices 11, and shifts the speed. The machine 200 is fixed in a specific state (for example, a specific gear ratio), and the vehicle is maintained in a state where it can run.

  On the other hand, if it is determined in step S1 that the second voltage V2 is higher than the second threshold value V2th, the transmission controller 100 advances the process to step S9 and executes a self-diagnosis of the device 11.

  In step S10, the transmission controller 100 determines whether each device 11 operates normally. If it is determined that any device 11 does not operate normally, the process proceeds to steps S11, S12. It is determined that the device 11 that did not operate normally has failed. Since the other devices 11 operate normally except for the failed device 11, the transmission controller 100 uses the other device 11 to control the other device 11 so that it can run. Run safe.

  If each device 11 operates normally in step S10, since no device 11 has failed, the transmission controller 100 returns the process to step S1 and executes the low voltage abnormality determination process again.

  Then, the effect of embodiment of this invention is demonstrated.

  According to the above embodiment, the low voltage abnormality is based on the first voltage V1 between the first switch 12 and the second switch 13 and the second voltage V2 between the second switch 13 and the device 11. It is determined whether or not

  However, the first voltage V1 is higher than the first threshold value V1th for determining that the first switch 12 is normal, and the second voltage V2 is normal for both the first switch 12 and the second switch 13. The second switch 13 determines that there is a difference ΔV between the second threshold V2th that is determined to be present and the lowest voltage Vmin that can guarantee the operation of the device 11, and the difference between the first voltage V1 and the second voltage V2. When it is smaller than the third threshold value ΔVth that is determined to be normal (hatched area in FIG. 2), it is impossible to determine whether or not a low voltage abnormality has occurred only from the first voltage V1 and the second voltage V2.

  In the above embodiment, in such a case, the self-diagnosis of the device 11 is also executed, and if there is a device 11 that does not operate normally by the self-diagnosis, the operation failure is regarded as being caused by a low voltage. Therefore, even in such a case, it can be determined that a low voltage abnormality has occurred.

  In other cases, since it is possible to determine the presence or absence of a low voltage abnormality based on the first voltage V1 and the second voltage V2, according to the present embodiment, it is possible to determine the presence or absence of a low voltage abnormality with high accuracy. .

  Further, by determining whether or not there is a low voltage abnormality, it becomes easy to identify the cause of the failure, and work efficiency when entering the service factory for repair is improved.

  The embodiment of the present invention has been described above, but the above embodiment is merely one example of application of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. is not.

  For example, the present embodiment is an example in which the low voltage abnormality determination device is incorporated in the transmission controller 100, but may be incorporated in an engine controller, a power control unit of a hybrid vehicle, or the like.

  This application claims the priority based on Japanese Patent Application No. 2015-141833 for which it applied to Japan Patent Office on July 16, 2015, and all the content of this application is integrated in this specification by reference.

Claims (2)

A power supply, a power supply line connecting the power supply and the device, a first switch provided in the middle of the power supply line, and in the middle of the power supply line and closer to the device than the first switch A low-voltage abnormality determination device that determines a low-voltage abnormality in which the input voltage to the device is insufficient in a power circuit provided with a second switch,
Obtaining a first voltage that is a voltage between the first switch and the second switch and a second voltage that is a voltage between the second switch and the device;
The first voltage is higher than a first threshold value for determining that the first switch is normal, and the second voltage is determined to be normal for both the first switch and the second switch. And the difference between the first voltage and the second voltage determines that the second switch is normal. If it is less than the third threshold, perform a self-diagnosis of the device;
If the device does not operate normally in the self-diagnosis, determine that the low voltage abnormality has occurred,
A low voltage abnormality determination device configured as described above. A power supply, a power supply line connecting the power supply and the device, a first switch provided in the middle of the power supply line, and in the middle of the power supply line and closer to the device than the first switch A low-voltage abnormality determination method for determining a low-voltage abnormality in which the input voltage to the device is insufficient in a power supply circuit including a second switch provided;
Obtaining a first voltage that is a voltage between the first switch and the second switch and a second voltage that is a voltage between the second switch and the device;
The first voltage is higher than a first threshold value for determining that the first switch is normal, and the second voltage is determined to be normal for both the first switch and the second switch. And the difference between the first voltage and the second voltage determines that the second switch is normal. If it is less than the third threshold, perform a self-diagnosis of the device;
If the device does not operate normally in the self-diagnosis, determine that the low voltage abnormality has occurred,
Low voltage abnormality judgment method.

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