JP7705606B2 - Vehicle control device - Google Patents

Description

This disclosure relates to an in-vehicle control device.

Patent Document 1 discloses a power supply system. The power supply system of Patent Document 1 includes a main battery and a sub-battery, and operates to switch the power supply source to the load from the main battery to the sub-battery when the power supply from the main battery is interrupted. In the power supply system of Patent Document 1, a body diode is provided in a switch between the sub-battery and the load, and when the power from the main battery is interrupted, power is supplied to the load via the body diode even when the switch is off, so the power supply is not interrupted.

JP 2020-182318 A

The power supply system of Patent Document 1 may not be able to supply the appropriate voltage to the load if the output voltage of the sub-battery drops. To eliminate this concern, it is desirable to introduce a discharge circuit that can supply the appropriate voltage to the load based on the power from the sub-battery, but simply introducing such a circuit will complicate the device configuration. On the other hand, in a system that can supply power from the sub-battery to the load, if the sub-battery is discharged for some reason, it is necessary to recharge the sub-battery in preparation for a malfunction. To this end, it is desirable to introduce a charging circuit that can supply the appropriate voltage to the sub-battery, but simply introducing such a circuit will lead to further complication.

The present disclosure relates to an on-board control device capable of backup operation to supply power based on a power storage unit, and has as one of its objectives to provide a technology that can adjust the charging voltage when charging the power storage unit and the discharging voltage when discharging the power storage unit with a simpler configuration, and can discharge the power storage unit via a path other than the path that adjusts the voltage.

The in-vehicle control device according to the present disclosure includes:
An in-vehicle control device for use in an in-vehicle system including a power supply unit that supplies electric power, a power storage unit different from the power supply unit, a first power path to which a voltage based on the power supply unit is applied, a second power path that is a path for supplying electric power supplied from the first power path to a load, a third power path different from the first power path and the second power path, and a fourth power path to which a voltage based on the power storage unit is applied, the in-vehicle control device controlling power supply from the power storage unit,
a voltage conversion unit that performs a first conversion operation of converting a voltage applied to the third power path and applying an output voltage to the fourth power path, and a second conversion operation of converting a voltage applied to the fourth power path and applying an output voltage to the third power path;
A control unit that controls the voltage conversion unit;
a first element unit capable of allowing a current to flow from the voltage conversion unit side to the second power path side and blocking a current from flowing from the second power path side to the voltage conversion unit side;
a second element unit capable of allowing a current to flow from the first power path side to the voltage conversion unit side and blocking a current from flowing from the voltage conversion unit side to the first power path side;
a third element capable of allowing a current to flow from the power storage unit side to the second power path side and blocking a current from flowing from the second power path side to the power storage unit side;
Equipped with.

The technology disclosed herein can adjust the charging voltage when charging the storage unit and the discharge voltage when discharging the storage unit with a simpler configuration, and can discharge the storage unit via a path other than the path that adjusts the voltage.

FIG. 1 is a circuit diagram illustrating an example of an in-vehicle system including an in-vehicle control device according to the first embodiment. FIG. 2 is a flowchart illustrating a flow of backup control performed in the vehicle control device of the first embodiment. FIG. 3 is an explanatory diagram illustrating an example of a power supply operation performed by the on-board control device of the first embodiment when the first power path is in a normal state. FIG. 4 is an explanatory diagram illustrating an example of the change in the voltage (power supply voltage) of the first power path over time when the first power path is in a normal state, the change in the operation of the voltage conversion unit, and the change in the voltage (storage unit voltage) of the fourth power path over time. FIG. 5 is an explanatory diagram illustrating an example of a power supply operation performed by the in-vehicle control device of the first embodiment when the first power path is equal to or lower than the first threshold value and the failure determination condition is not satisfied. Figure 6 is an explanatory diagram that illustrates examples of changes in the voltage of the first power path and the voltage of the second power path (load voltage) over time when the first power path is below the first threshold and the failure determination condition is not met, changes in the current of the third element unit and the fourth element unit, changes in the operation of the voltage conversion unit, and changes in the voltage of the fourth power path. FIG. 7 is an explanatory diagram illustrating an example of a power supply operation performed by the on-board control device of the first embodiment immediately after the first power path is equal to or lower than the first threshold and the failure determination condition is met. FIG. 8 is an explanatory diagram illustrating an example of a power supply operation performed by the vehicle-mounted control device of the first embodiment after a certain amount of time has elapsed since the malfunction determination condition is satisfied. Figure 9 is an explanatory diagram that illustrates an example of the voltage changes in the first power path and the second power path, the current changes in the first element unit and the third element unit, and the change in the operation of the voltage conversion unit over time when the first power path is below the first threshold value and the failure determination condition is met. FIG. 10 is an explanatory diagram illustrating an example of a power supply operation performed by the on-board control device of the first embodiment when an abnormality occurs in the fourth element unit while the first power path is in a normal state. FIG. 11 is an explanatory diagram illustrating the voltage change in the first power path and the current changes in the first element unit and the fourth element unit over time when an abnormality occurs in the fourth element unit while the first power path is in a normal state. FIG. 12 is an explanatory diagram illustrating an example of a power supply operation performed by the on-board control device of the first embodiment when the first power path is equal to or higher than the overvoltage threshold. FIG. 13 is an explanatory diagram illustrating an example of the voltage change in the first power path over time when the first power path is above the overvoltage threshold, the change in current in the third element unit and the fourth element unit, the change in operation of the voltage conversion unit, and the voltage change in the fourth power path. FIG. 14 is a circuit diagram illustrating an example of an in-vehicle system including the in-vehicle control device according to the second embodiment. FIG. 15 is an explanatory diagram illustrating an example of a power supply operation performed by the on-board control device of the second embodiment when the first power path is in a normal state. FIG. 16 is an explanatory diagram illustrating an example of the power supply operation performed by the in-vehicle control device of the second embodiment when the second power path is equal to or lower than the first threshold value and the failure determination condition is not satisfied. FIG. 17 is an explanatory diagram illustrating an example of a power supply operation performed by the on-board control device of the second embodiment immediately after the first power path is equal to or lower than the first threshold value and the failure determination condition is met. FIG. 18 is an explanatory diagram illustrating an example of a power supply operation performed by the vehicle-mounted control device of the second embodiment after a certain amount of time has elapsed since the malfunction determination condition was met. FIG. 19 is an explanatory diagram illustrating an example of a power supply operation performed by the on-board control device of the second embodiment when the first power path is equal to or higher than the overvoltage threshold. FIG. 20 is a circuit diagram illustrating an example of an in-vehicle system including the in-vehicle control device according to the third embodiment. FIG. 21 is an explanatory diagram showing a modified example of the element portion.

[Description of the embodiments of the present disclosure]
The following describes exemplary embodiments of the present disclosure. The following exemplary features [1] to [13] may be combined in any compatible combination.

[1] An in-vehicle control device for use in an in-vehicle system including a power supply unit that supplies electric power, a power storage unit different from the power supply unit, a first power path to which a voltage based on the power supply unit is applied, a second power path that is a path for supplying the electric power supplied from the first power path to a load, a third power path different from the first power path and the second power path, and a fourth power path to which a voltage based on the power storage unit is applied, the in-vehicle control device controlling power supply from the power storage unit,
a voltage conversion unit that performs a first conversion operation of converting a voltage applied to the third power path and applying an output voltage to the fourth power path, and a second conversion operation of converting a voltage applied to the fourth power path and applying an output voltage to the third power path;
A control unit that controls the voltage conversion unit;
a first element unit capable of allowing a current to flow from the voltage conversion unit side to the second power path side and blocking a current from flowing from the second power path side to the voltage conversion unit side;
a second element unit capable of allowing a current to flow from the first power path side to the voltage conversion unit side and blocking a current from flowing from the voltage conversion unit side to the first power path side;
a third element capable of allowing a current to flow from the power storage unit side to the second power path side and blocking a current from flowing from the second power path side to the power storage unit side;
An in-vehicle control device comprising:

The vehicle-mounted control device of the above [1] can charge the storage unit while applying a desired voltage to the fourth power path by having the voltage conversion unit perform a first conversion operation in a state in which the second element unit allows a current to flow from the first power path to the voltage conversion unit. On the other hand, by having the voltage conversion unit perform a second conversion operation in a state in which the first element unit allows a current to flow from the voltage conversion unit to the second power path, it is possible to supply power to the second power path while applying a desired voltage to the third power path. In other words, this vehicle-mounted control device can adjust the charging voltage when charging the storage unit and the discharging voltage when discharging the storage unit with a simpler configuration, and in some cases, the second element unit can block the current from flowing from the voltage conversion unit to the first power path. Furthermore, since the third element unit is provided and can allow a current to flow from the storage unit to the second power path, the storage unit can be discharged via a path other than the path in which the voltage is adjusted by the voltage conversion unit. Furthermore, since the third element portion is capable of blocking the flow of current from the second power path side to the storage unit side, in some cases it is possible to block the flow of current from the second power path side to the storage unit via the third element portion.

[2] The in-vehicle control device described in [1], further comprising a fourth element unit capable of allowing current to flow from the first power path side to the second power path side and blocking current from flowing from the second power path side to the first power path side.

In the vehicle control device of [2] above, the fourth element unit can allow current to flow from the first power path side to the second power path side, so that power based on the power supply unit can be directly supplied to the second power path via the fourth element unit. On the other hand, in some cases, the fourth element unit can block current from flowing from the second power path side to the first power path side.

[3] the fourth element unit is configured to block current flow between the first power path and the second power path through itself when the fourth element unit is in an off state, and to allow current to flow from the first power path to the second power path through itself when the fourth element unit is in an on state;
When the voltage of the first power path exceeds a first threshold, the control unit turns on the fourth element unit;
The vehicle control device according to claim 2, wherein when the voltage of the first power path is equal to or lower than the first threshold value, the control unit turns off the fourth element unit while allowing a current to flow from the storage unit side to the second power path side in the third element unit.

The vehicle control device of [3] can supply power based on the power supply unit directly to the second power path with reduced loss by turning on the fourth element when the voltage of the first power path exceeds the first threshold. On the other hand, when the voltage of the first power path is equal to or lower than the first threshold, the control unit can turn off the fourth element while allowing current to flow from the storage unit side to the second power path side in the third element. This makes it possible to flow a discharge current from the storage unit to the second power path via the third element while preventing the influence of the first power path from extending to the second power path via the fourth element.

[4] An abnormality detection unit that detects an abnormality in the fourth element unit,
the first element unit is configured to, when the first element unit is in an off state, block a current from flowing in both directions between the third power path and the second power path through the first element unit, and when the first element unit is in an on state, allow a current to flow from the third power path to the second power path through the first element unit,
The in-vehicle control device according to claim 2 or 3, wherein when the abnormality detection unit detects an abnormality in the fourth element unit, the control unit turns on the first element unit while allowing a current to flow from the first power path side to the third power path side in the second element unit.

In the vehicle control device of [4], when the abnormality detection unit detects an abnormality in the fourth element unit, the control unit can turn on the first element unit while allowing current to flow from the first power path side to the third power path side in the second element unit, so that power can be supplied from the first power path side to the second power path side using the path of the second element unit and the first element unit. On the other hand, the first element unit can also be turned off, in which case it is possible to prevent current from flowing from the second power path side to the third power path side via the first element unit.

[5] The fourth element unit is configured to block current flow between the first power path and the second power path through itself in both directions when the fourth element unit is in an off state, and to allow current to flow from the first power path to the second power path through itself when the fourth element unit is in an on state,
When the voltage of the first power path exceeds a first threshold and is less than a voltage threshold that is greater than the first threshold, the control unit turns on the fourth element unit;
The vehicle control device according to any one of [2] to [4], wherein when the voltage of the first power path is equal to or higher than the voltage threshold, the control unit turns off the fourth element unit while allowing current to flow from the storage unit side to the second power path side in the third element unit.

The vehicle control device of [5] can supply power based on the power supply unit directly to the second power path with reduced loss by turning on the fourth element when the voltage of the first power path is large enough to exceed the first threshold but not large enough to reach the voltage threshold. On the other hand, when the voltage of the first power path rises too much to the extent that it exceeds the voltage threshold, the fourth element can be turned off while allowing current to flow from the storage unit side to the second power path side in the third element, so that a discharge current can be flowed from the storage unit to the second power path via the third element while preventing the influence of an overvoltage on the first power path from reaching the second power path via the fourth element.

[6] The in-vehicle control device described in [5], wherein when the voltage of the first power path is equal to or higher than the voltage threshold, the control unit causes the voltage conversion unit to perform the first conversion operation while allowing current to flow from the storage unit side to the second power path side in the third element unit.

The vehicle control device of [6] above can, when the voltage of the first power path rises too much to the extent that it becomes equal to or higher than the voltage threshold, supply power from the voltage conversion unit to the storage unit side by utilizing power from the first power path, while flowing a discharge current to the second power path via the third element unit.

[7] The second element unit is configured to block current flow between the first power path and the third power path through itself in both directions when the second element unit is in an off state, and to allow current to flow from the first power path to the third power path through itself when the second element unit is in an on state,
The control unit turns on the second element unit on the condition that the voltage of the first power path exceeds a first threshold value and is less than a voltage threshold value that is greater than the first threshold value;
The in-vehicle control device according to any one of [1] to [3], wherein, when the voltage of the first power path is equal to or higher than the voltage threshold, the control unit turns off the second element unit while allowing a current to flow from the third power path side to the second power path side in the first element unit, and causes the voltage conversion unit to perform the second conversion operation.

The vehicle-mounted control device of [7] can turn on the second element unit and enable power supply from the first power path side to the voltage conversion unit side, provided that the voltage of the first power path exceeds the first threshold value and is less than the voltage threshold value. On the other hand, when the voltage of the first power path rises too much above the voltage threshold value, the second element unit can be turned off to cut off current flow from the first power path side to the third power path side and to allow current flow from the third power path side to the second power path side via the first element unit, and the voltage conversion unit can be caused to perform a second conversion operation.

[8] An in-vehicle control device as described in any one of [1] to [7], wherein when a predetermined condition is met when the voltage of the first power path is equal to or lower than a first threshold value, the control unit causes the voltage conversion unit to perform the first conversion operation while allowing current to flow from the storage unit side to the second power path side in the third element unit.

The vehicle control device of [8] above can supply power to the power storage unit by causing the voltage conversion unit to perform a first conversion operation if a specified condition is met, even if the voltage of the first power path drops below the first threshold value. In this way, while supplying power to the power storage unit, it can also supply power to the second power path via the third element unit.

[9] The predetermined condition includes a condition that a predetermined malfunction determination condition is not satisfied,
When the voltage of the first power path is equal to or lower than the first threshold, the control unit causes the voltage conversion unit to perform the first conversion operation while allowing a current to flow from the first power path side to the voltage conversion unit side in the second element unit, on the condition that the failure determination condition is not satisfied;
The in-vehicle control device described in [8], wherein when the voltage of the first power path is equal to or lower than the first threshold value and the failure determination condition is met, the control unit causes the voltage conversion unit to perform the second conversion operation while blocking current flow from the voltage conversion unit side to the first power path side in the second element unit and allowing current flow from the third power path side to the second power path side in the first element unit.

The vehicle control device of [9] above can charge the storage unit by causing the voltage conversion unit to perform the first conversion operation while allowing current to flow to the voltage conversion unit side through the second element unit, provided that the failure determination condition is not satisfied, even when the voltage of the first power path drops below the first threshold. On the other hand, when the failure determination condition is satisfied, this vehicle control device can supply the second power path with a voltage adjusted based on the voltage conversion operation of the voltage conversion unit while blocking backflow to the first power path.

[10] The third element unit is configured to block current flow between the fourth power path and the second power path through itself when the third element unit is in an off state, and to allow current to flow from the fourth power path to the second power path through itself when the third element unit is in an on state,
the control unit controls at least the third element unit to be turned on and off;
The in-vehicle control device according to [9], wherein, when the voltage of the first power path is equal to or lower than a first threshold value, when a switch occurs from a state in which the failure determination condition is not satisfied to a state in which the failure determination condition is satisfied, the control unit maintains the third element unit in an on state before and after the switch, and after the switch, the control unit causes the voltage conversion unit to perform the second conversion operation while blocking current flow from the voltage conversion unit side to the first power path side in the second element unit and allowing current flow from the third power path side to the second power path side in the first element unit, and when the voltage conversion unit satisfies a predetermined operating condition after the switch, the control unit switches the third element unit to an off state.

The vehicle control device of [10] can quickly supply power from the storage unit to the second power path by turning on the third element unit when the voltage of the first power path is equal to or lower than the first threshold and the failure determination condition is not satisfied. When the voltage of the first power path is equal to or lower than the first threshold and the failure determination condition is switched from not being satisfied to being satisfied, the vehicle control device can supply power whose voltage has been adjusted by the second conversion operation to the second power path via the third power path and the first element unit after the switchover while preventing reverse flow to the first power path. Moreover, since the vehicle control device can maintain the third element unit in the on state before and after the switchover, the power supply from the storage unit to the second power path via the third element unit can be continued even if the rise of the output of the voltage conversion unit is slow after the switchover. Furthermore, this in-vehicle control device can narrow down the discharge path to the path of the first element unit among the first element unit and the third element unit by switching the third element unit to the off state when the voltage conversion unit satisfies predetermined operating conditions after switching.

[11] The failure determination condition includes a condition in which a current flows from the voltage conversion unit side to the first power path side via the second element unit,
when the voltage of the first power path is equal to or lower than the first threshold value, on the condition that no current flows from the voltage conversion unit side to the first power path side via the second element unit, the control unit causes the voltage conversion unit to perform the first conversion operation while allowing a current to flow from the first power path side to the voltage conversion unit side in the second element unit, and allows a current to flow from the power storage unit side to the second power path side in the third element unit;
The in-vehicle control device described in [9] or [10], wherein when the voltage of the first power path is equal to or lower than the first threshold and current flows from the voltage conversion unit side to the first power path side via the second element unit, the control unit causes the voltage conversion unit to perform the second conversion operation while blocking current flow from the voltage conversion unit side to the first power path side in the second element unit and allowing current to flow from the third power path side to the second power path side in the first element unit.

The vehicle-mounted control device of [11] above can charge the storage unit by making the voltage conversion unit perform the first conversion operation after confirming that no current flows to the first power path through the second element unit, i.e., that there is a high possibility that a ground fault has not occurred in the first power path, when the voltage of the first power path is equal to or lower than the first threshold value. The vehicle-mounted control device can then perform discharging through the third element unit in parallel with the supply of power to the storage unit side by the first conversion operation. On the other hand, when the voltage of the first power path is equal to or lower than the first threshold value and a current flows to the first power path through the second element unit, i.e., when there is a possibility that a ground fault has occurred in the first power path, the second element unit can block the current from flowing to the first power path, thereby suppressing the influence of the ground fault from reaching the third power path. By making the voltage conversion unit perform the second conversion operation while allowing the current to flow to the second power path in the first element unit, it is possible to supply power whose voltage has been adjusted by the voltage conversion unit to the second power path while suppressing the influence of the ground fault.

[12] The failure determination condition includes a condition that a voltage of the first power path is equal to or lower than a second threshold value that is lower than the first threshold value,
on a condition that a voltage of the first power path is equal to or lower than the first threshold value and exceeds the second threshold value, the control unit causes the voltage conversion unit to perform the first conversion operation while allowing a current to flow from the first power path side to the voltage conversion unit side in the second element unit, and allows a current to flow from the power storage unit side to the second power path side in the third element unit,
The vehicle control device described in any one of [9] to [11], wherein, when the voltage of the first power path is equal to or lower than the second threshold value, the control unit blocks current flow from the voltage conversion unit side to the first power path side in the second element unit, and allows current to flow from the third power path side to the second power path side in the first element unit while causing the voltage conversion unit to perform the second conversion operation.

The vehicle-mounted control device of [12] above can charge the storage unit by making the voltage conversion unit perform the first conversion operation when the voltage of the first power path is equal to or lower than the first threshold, that is, after confirming that the voltage of the first power path exceeds the second threshold, that is, that the voltage of the first power path is not too low. Then, this vehicle-mounted control device can perform discharging through the third element unit in parallel with the supply of power to the storage unit side by the first conversion operation. On the other hand, when the voltage of the first power path is equal to or lower than the second threshold, that is, when the voltage of the first power path is too low, the second element unit can block the current from flowing to the first power path side, so that even if a ground fault occurs in the first power path, the influence of the ground fault on the third power path side can be suppressed. Then, by making the voltage conversion unit perform the second conversion operation while allowing the current to flow to the second power path side in the first element unit, it is possible to supply power whose voltage has been adjusted by the voltage conversion unit to the second power path while suppressing the influence of the voltage drop of the first power path.

[1 3 ] The failure determination condition includes a condition in which a predetermined failure signal is given to the vehicle-mounted control device from an external device different from the vehicle-mounted control device,
on the condition that the voltage of the first power path is equal to or lower than the first threshold value and the failure signal is not provided from the external device, the control unit causes the voltage conversion unit to perform the first conversion operation while allowing a current to flow from the first power path side to the voltage conversion unit side in the second element unit, and allows a current to flow from the power storage unit side to the second power path side in the third element unit,
The in-vehicle control device according to any one of [9] to [12], wherein, when the voltage of the first power path is equal to or lower than the first threshold value and the failure signal is given from the external device, the control unit blocks current flow from the voltage conversion unit side to the first power path side in the second element unit, and allows current to flow from the third power path side to the second power path side in the first element unit while causing the voltage conversion unit to perform the second conversion operation.

The vehicle-mounted control device of [13] above can, when the voltage of the first power path is equal to or lower than the first threshold, make the voltage conversion unit perform the first conversion operation after confirming that no fault signal has been given from an external device, thereby charging the power storage unit. The vehicle-mounted control device can discharge the power through the third element unit in parallel with the power supply to the power storage unit side by the first conversion operation. On the other hand, when the voltage of the first power path is equal to or lower than the first threshold and a fault signal is generated, the voltage conversion unit can perform the second conversion operation while blocking the current flow to the first power path side in the second element unit and allowing the current flow to the second power path side in the first element unit. Therefore, even if a ground fault or the like occurs in the first power path when a fault signal is generated, the influence of the ground fault or the like can be suppressed, and power whose voltage has been adjusted by the voltage conversion unit can be supplied to the second power path.

[14] An in-vehicle control device described in any one of [8] to [13], wherein during a period in which the voltage conversion unit performs the first conversion operation while allowing current to flow from the storage unit side to the second power path side in the third element unit, the control unit makes the power supplied from the voltage conversion unit to the fourth power path side greater than the power supplied to the second power path side via the third element unit.

The vehicle-mounted control device of [14] can make the charging power based on the first conversion operation larger than the discharging power through the third element when the first conversion operation and the discharging through the third element are performed in parallel. Therefore, when the parallel operations are performed, it is possible to supply power to the second conductive path while more reliably securing the charging current to the storage unit.

[15] An in-vehicle control device described in any one of [1] to [14], wherein when the voltage of the first power path exceeds a first threshold value and the output voltage of the storage unit is equal to or lower than a predetermined value, the control unit causes the voltage conversion unit to perform the first conversion operation while allowing current to flow from the first power path side to the voltage conversion unit side in the second element unit.

The on-board control device of [15] above can charge the power storage unit through the first conversion operation when the output voltage of the power storage unit drops to a predetermined value or lower.
[Details of the embodiment of the present disclosure]

First Embodiment
1. Overview of the In-Vehicle System Fig. 1 shows an in-vehicle system 2. The in-vehicle system 2 in Fig. 1 mainly includes an in-vehicle power supply system 3 and a load 101. The in-vehicle power supply system 3 is also referred to as a power supply system 3 in the following description. The in-vehicle system 2 is a system that supplies power to the load 101 by the power supply system 3 to operate the load 101. In Fig. 1, the load 101 is illustrated as an example of an in-vehicle load, but the in-vehicle system 2 may be provided with other loads.

The load 101 is an electrical component mounted on the vehicle. The load 101 operates by receiving power supplied via the power path 80. The type of the load 101 is not limited. Various known in-vehicle components may be adopted as the load 101. The load 101 may have multiple electrical components or may be a single electrical component.

The power supply system 3 is a system that supplies power to the load 101. The power supply system 3 supplies power to the load 101 using the power supply unit 91 or the power storage unit 92 as a power supply source. The power supply system 3 can supply power to the load 101 from the power supply unit 91, and can supply power to the load 101 from the power storage unit 92 when the power supply from the power supply unit 91 is interrupted due to, for example, a malfunction. Depending on the situation, the power storage unit 92 may be used as a supply source that supplies power to the load 101 when the power supply from the power supply unit 91 to the load 101 is not interrupted.

2. Overview of the Power Supply System The power supply system 3 includes a power supply unit 91, a power storage unit 92, an in-vehicle control device 10, etc. In the representative example shown in Fig. 1, a first power path 81, a second power path 82, a third power path 83, a fourth power path 84, a conductive path 89, etc. are configured as parts of the in-vehicle control device 10. However, any of the first power path 81, the second power path 82, the third power path 83, the fourth power path 84, and the conductive path 89 may not be part or all of the components of the in-vehicle control device 10.

The power supply unit 91 is an on-board power supply capable of supplying power to the load 101. The power supply unit 91 is configured as a known on-board power storage unit such as a lead battery. The power supply unit 91 may be configured with a battery other than a lead battery (e.g., a lithium-ion battery or other battery, etc.), and may have a power supply means other than a battery instead of or in addition to a battery. In the example of FIG. 1, the positive electrode of the power supply unit 91 is electrically connected to the first power path 81, which is a part of the power path 80, in a configuration in which it is shorted to the first power path 81. The negative electrode of the power supply unit 91 is electrically connected to the ground in a configuration in which it is shorted to the ground. The power supply unit 91 applies a constant DC voltage to the first power path 81. The voltage applied by the power supply unit 91 to the first power path 81 may vary slightly from the above constant value.

The storage unit 92 is a power source different from the power source unit 91. The storage unit 92 is a power source that becomes a power supply source at least when the power supply from the power source unit 91 is interrupted. The storage unit 92 is composed of a known storage means such as an electric double layer capacitor (EDLC). The storage unit 92 may be composed of a capacitor other than an electric double layer capacitor, and may include other storage means (such as a battery) instead of or in addition to a capacitor. In the example of FIG. 1, the positive electrode of the storage unit 92 is electrically connected to the fourth power path 84 in a configuration in which it is shorted to the fourth power path 84. The negative electrode of the storage unit 92 is electrically connected to the ground in a configuration in which it is shorted to the ground. The output voltage of the storage unit 92 (the voltage applied to the fourth power path 84 by the storage unit 92) may be larger, smaller, or approximately the same as the output voltage of the power source unit 91 (the voltage applied to the first power path 81 by the power source unit 91).

In this specification, unless otherwise specified, voltage refers to a voltage relative to a ground potential (e.g., 0 V) and is the potential difference with respect to the ground potential. For example, the voltage applied to the first power path 81 is the potential difference between the potential of the first power path 81 and the ground potential. The voltage applied to the fourth power path 84 is the potential difference between the potential of the fourth power path 84 and the ground potential.

The power path 80 is a path through which power based on the power supply unit 91 is transmitted, and is a path that supplies the power based on the power supply unit 91 to the load 101. In the example of FIG. 1, the power path 80 has a first power path 81 to which a voltage based on the power supply unit 91 is applied, and a second power path 82 that is a path that supplies the power supplied from the first power path 81 to the load 101.

The first power path 81 is a conductive path constituting a part or all of the power supply path between the power supply unit 91 and the second element unit 22. A voltage equal to or substantially equal to the output voltage of the power supply unit 91 is applied to the first power path 81. A part of one end of the first power path 81 is electrically connected to the positive electrode of the power supply unit 91 in a configuration in which it is short-circuited. In the example of FIG. 1, a part of the other end of the first power path 81 is electrically connected to one end of the second element unit 22 (in the example of FIG. 1, a drain terminal that is one end of a semiconductor switch) in a configuration in which it is short-circuited. Furthermore, a part of the first power path 81 is electrically connected to one end of the fourth element unit 24 (in the example of FIG. 1, a drain terminal that is one end of a semiconductor switch 24A) in a configuration in which it is short-circuited. The first power path 81 may be provided with a relay or a fuse. The first power path 81 functions to, for example, bring the positive electrode of the power supply unit 91, one end of the second element unit 22, and one end of the fourth element unit 24 to the same potential or approximately the same potential.

The second power path 82 is a conductive path that constitutes part or all of the power supply path between the first element section 21 and the load 101. A part of one end of the second power path 82 is electrically connected to the other end of the first element section 21 (in the example of FIG. 1, the drain terminal that is the other end of the semiconductor switch 21B). Furthermore, a part of the second power path 82 is electrically connected in a short-circuited configuration to the other end of the fourth element section 24 (in the example of FIG. 1, the drain terminal that is one end of the semiconductor switch 24B), and is electrically connected in a short-circuited configuration to the other end of the third element section 23 (in the example of FIG. 1, the drain terminal that is one end of the semiconductor switch 23B). In the example of FIG. 1, a part of the other end of the second power path 82 is electrically connected to the load 101 in a configuration in which it is short-circuited to one end of the load 101. A relay or a fuse may be provided in the second power path 82. The second power path 82 functions, for example, to bring the other end of the first element portion 21, the other end of the fourth element portion 24, the other end of the third element portion 23, and one end of the load 101 to the same potential or approximately the same potential.

The third power path 83 is a power path different from the first power path 81 and the second power path 82. A portion of one end of the third power path 83 is electrically connected to the other end of the second element section 22 (in the example of FIG. 1, the source terminal which is the other end of the semiconductor switch) in a short-circuited configuration. A portion of the other end of the third power path 83 is electrically connected to one end of the voltage conversion section 30 in a short-circuited configuration. A portion of the third power path 83 is electrically connected to one end of the first element section 21 (in the example of FIG. 1, the drain terminal which is one end of the semiconductor switch 21A) in a short-circuited configuration. The third power path 83 functions, for example, to make one end of the first element section 21, the other end of the second element section 22, and one end of the voltage conversion section 30 have the same potential or approximately the same potential.

The fourth power path 84 is a power path different from the first power path 81, the second power path 82, and the third power path 83, and is a power path to which a voltage based on the storage unit 92 is applied. A part of one end of the fourth power path 84 is electrically connected to the other end of the voltage conversion unit 30 in a configuration in which it is shorted. A part of the other end of the fourth power path 84 is electrically connected to the positive electrode of the storage unit 92 in a configuration in which it is shorted. A part of the fourth power path 84 is electrically connected to one end of the third element unit 23 (in the example of FIG. 1, the drain terminal that is one end of the semiconductor switch 23A) in a configuration in which it is shorted. The fourth power path 84 functions, for example, to make the other end of the voltage conversion unit 30, the positive electrode of the storage unit 92, and one end of the third element unit 23 have the same potential or approximately the same potential.

3. Details of the Vehicle Control Device The vehicle control device 10 is used in the vehicle system 2, and is a device that controls power supply from the power storage unit 92. The vehicle control device 10 is a backup control device that can control a backup operation that outputs power based on the power storage unit 92. The vehicle control device 10 includes a first power path 81, a second power path 82, a third power path 83, a fourth power path 84, a control unit 16, a voltage conversion unit 30, a first element unit 21, a second element unit 22, a third element unit 23, a fourth element unit 24, voltage detection units 41, 43, 44, and the like.

In a representative example, the vehicle control device 10 has a first power path 81, a second power path 82, a third power path 83, and a fourth power path 84, but it may have only a portion of each, and any or all of the power paths may not be elements of the vehicle control device 10.

In the representative example of FIG. 1, the first element section 21 is composed of two semiconductor switches 21A and 21B. The second element section 22 is composed of one semiconductor switch. The third element section 23 is composed of two semiconductor switches 23A and 23B. The fourth element section 24 is composed of two semiconductor switches 24A and 24B. In the example of FIG. 1, the semiconductor switches 21A, 21B, 22, 23A, 23B, 24A, and 24B are all composed of N-channel type FETs (Field Effect Transistors).

The first element section 21 is a switch section that can allow a current to flow from the voltage conversion section 30 side to the second power path 82 side and can block a current from flowing from the second power path 82 side to the voltage conversion section 30 side. The semiconductor switches 21A and 21B that constitute the first element section 21 are connected in the opposite directions to each other. In the example of FIG. 1, the drain of the semiconductor switch 21A is shorted to the third power path 83, the drain of the semiconductor switch 21B is shorted to the second power path 82, and the source of the semiconductor switch 21A is shorted to the source of the semiconductor switch 21B. The first element section 21 is in the off state means that both the semiconductor switches 21A and 21B are in the off state. When the first element section 21 is in the off state, the current flow through the first element section 21 is blocked in both directions, and both the current flow from the second power path 82 side to the voltage conversion section 30 side and the current flow from the voltage conversion section 30 side to the second power path 82 side are blocked. The on state of the first element unit 21 means that both of the semiconductor switches 21A and 21B are on. When the first element unit 21 is on, bidirectional current is permitted through the first element unit 21, and both a current flow from the second power path 82 side to the voltage conversion unit 30 side and a current flow from the voltage conversion unit 30 side to the second power path 82 side are permitted.

The second element section 22 is configured to allow current to flow from the first power path 81 to the voltage conversion section 30, and is configured to block current from flowing from the voltage conversion section 30 to the first power path 81. In the example of FIG. 1, the drain of the second element section 22 is electrically connected to be shorted to the third power path 83, and the source of the second element section 22 is electrically connected to be shorted to the first power path 81. When the second element section 22 is in the on state, current is allowed to flow in both directions through the second element section 22. When the second element section 22 is in the off state, current is always blocked from flowing from the voltage conversion section 30 to the first power path 81 through the second element section 22.

The third element portion 23 is a switch portion capable of allowing a current to flow from the power storage portion 92 side to the second power path 82 side and blocking a current from flowing from the second power path 82 side to the power storage portion 92 side. The semiconductor switches 23A and 23B constituting the third element portion 23 are connected in the opposite directions to each other. In the example of Fig. 1, the drain of the semiconductor switch 23A is short-circuited to the fourth power path 84, the drain of the semiconductor switch 23B is short-circuited to the second power path 82, and the source of the semiconductor switch 24A is short-circuited to the source of the semiconductor switch 24B. The third element portion 23 being in the off state means that both the semiconductor switches 23A and 23B are in the off state. When the third element portion 23 is in the off state, current flow through the third element portion 23 is blocked in both directions, and both the flow of current from the second power path 82 side to the power storage portion 92 side through the third element portion 23 and the flow of current from the power storage portion 92 side to the second power path 82 side through the third element portion 23 are blocked. The third element portion 23 being in the on state means that both of the semiconductor switches 23A and 23B are in the on state. When the third element portion 23 is in the on state, current flow through the third element portion 23 is permitted in both directions, and both the flow of current from the second power path 82 side to the power storage portion 92 side and the flow of current from the power storage portion 92 side to the second power path 82 side are permitted.

The fourth element section 24 is a switch section that can allow current to flow from the first power path 81 side to the second power path 82 side, and can block current from flowing from the second power path 82 side to the first power path 81 side. The semiconductor switches 24A and 24B that constitute the fourth element section 24 are connected in the opposite directions to each other. In the example of FIG. 1, the drain of the semiconductor switch 24A is shorted to the first power path 81, the drain of the semiconductor switch 24B is shorted to the second power path 82, and the source of the semiconductor switch 24A is shorted to the source of the semiconductor switch 24B. The fourth element section 24 being in the off state means that both the semiconductor switches 24A and 24B are in the off state. When the fourth element unit 24 is in the off state, current flow through the fourth element unit 24 is blocked in both directions, and both the flow of current from the first power path 81 side to the second power path 82 side through the fourth element unit 24 and the flow of current from the second power path 82 side to the first power path 81 side through the fourth element unit 24 are blocked. When the fourth element unit 24 is in the on state, both the semiconductor switches 24A and 24B are in the on state. When the fourth element unit 24 is in the on state, current flow through the fourth element unit 24 is permitted in both directions, and both the flow of current from the first power path 81 side to the second power path 82 side and the flow of current from the second power path 82 side to the first power path 81 side are permitted.

The voltage conversion unit 30 is configured with a known voltage conversion circuit such as a DC-DC converter. In the example of FIG. 1, the voltage conversion unit 30 performs voltage conversion between the third power path 83 and the fourth power path 84. The voltage conversion unit 30 is a device that performs a first conversion operation of voltage conversion to increase or decrease the voltage applied to the third power path 83 and apply the output voltage to the fourth power path 84, and a second conversion operation of voltage conversion to increase or decrease the voltage applied to the fourth power path 84 and apply the output voltage to the third power path 83. In this way, the voltage conversion unit 30 performs voltage conversion in both directions. The operation of the voltage conversion unit 30 is controlled by the control unit 16.

The control unit 16 is a device that controls the voltage conversion unit 30, the first element unit 21, the second element unit 22, the third element unit 23, the fourth element unit 24, etc. The control unit 16 has an information processing device having an information processing function, a calculation function, a control function, etc., and may be configured by this information processing device, or may be configured by the information processing device and another device. For example, the control unit 16 may have a common control device that controls the voltage conversion unit 30, the first element unit 21, the second element unit 22, the third element unit 23, and the fourth element unit 24, or the device that controls one part of them may be separate from the device that controls the other parts.

The voltage detection unit 41 is a circuit that provides the control unit 16 with a detection value (e.g., an analog voltage value) that can identify the value of the voltage applied to the first power path 81. The voltage detection unit 43 is a circuit that provides the control unit 16 with a detection value (e.g., an analog voltage value) that can identify the value of the voltage applied to the third power path 83. The voltage detection unit 44 is a circuit that provides the control unit 16 with a detection value (e.g., an analog voltage value) that can identify the value of the voltage applied to the fourth power path 84.

4. Operation of the Vehicle Control Device The following description relates to control for the backup operation performed by the vehicle control device 10. Fig. 2 is a flowchart illustrating the flow of control for the backup operation.

When a predetermined start condition is satisfied, the control unit 16 starts the control for the backup operation shown in FIG. 2. The above "start condition" may be, for example, a condition that "the vehicle is in a start state", a predetermined instruction is given from an external device (for example, an external ECU), or other conditions. In the representative example described below, the control unit 16 determines that the above start condition is satisfied when the vehicle equipped with the in-vehicle system 2 is in a start state, and starts the control for the backup operation shown in FIG. 2. When the vehicle is in a start state, for example, a start switch such as an ignition switch in a hybrid vehicle or a power switch in an electric vehicle is switched from an off state to an on state.

In addition, when the control unit 16 starts the control of FIG. 2, it may continue the control of FIG. 2 until a predetermined end condition is satisfied, and may end the control of FIG. 2 when the predetermined end condition is satisfied. The predetermined end condition may be, for example, that the start switch of the vehicle is switched from an on state to an off state, or may be another condition.

When the control unit 16 starts the control for the backup operation shown in FIG. 2, in step S1, it determines whether the voltage of the first power path 81 is equal to or lower than the low voltage threshold Vth1. The low voltage threshold Vth1 corresponds to an example of a first threshold. When the control unit 16 determines in step S1 that the voltage of the first power path 81 is not equal to or lower than the low voltage threshold Vth1, it determines in step S2 whether the voltage of the first power path 81 is equal to or higher than the overvoltage threshold Vth3. The overvoltage threshold Vth3 corresponds to an example of a voltage threshold. When the control unit 16 determines in step S2 that the voltage of the first power path 81 is not equal to or higher than the overvoltage threshold Vth3, it sets the first element unit 21 to the OFF state, the second element unit 22 to the ON state, the third element unit 23 to the OFF state, and the fourth element unit 24 to the ON state in step S3.

In this way, when the voltage of the first power path 81 exceeds the low voltage threshold Vth1 (first threshold) and is less than the overvoltage threshold Vth3 (voltage threshold) that is greater than the low voltage threshold Vth1, the control unit 16 turns on the fourth element unit 24.

After step S3, the control unit 16 determines whether the fourth element unit 24 is abnormal in step S4. For example, the control unit 16 may determine that the fourth element unit 24 is abnormal when the voltage of the second power path 82 immediately after step S3 is equal to or lower than a predetermined reference value. Alternatively, the control unit 16 may determine that the fourth element unit 24 is abnormal when the voltage applied to the gate of the fourth element unit 24 is an off voltage while the fourth element unit 24 is being turned on. Alternatively, the control unit 16 may determine that the fourth element unit 24 is abnormal when there is a temperature abnormality such that the temperature near the fourth element unit 24 exceeds a threshold temperature. In this embodiment, the control unit 16 corresponds to an example of an abnormality detection unit and has a function of detecting an abnormality in the fourth element unit 24.

When the control unit 16 determines in step S4 that the fourth element unit 24 is not abnormal, it determines in step S5 whether the charging condition is satisfied. In a typical example, the charging condition is satisfied when the voltage of the fourth power path 84 is equal to or lower than a predetermined value at least when the voltage conversion unit 30 is in a state where the charging operation is stopped (a state where the first conversion operation is not being performed). The control unit 16 determines in step S5 whether the charging condition is satisfied, and if it is determined that the charging condition is satisfied, it proceeds to step S6, and if it is determined that the charging condition is not satisfied, it proceeds to step S7. In a typical example, the charging condition is not satisfied when the voltage of the fourth power path 84 is equal to or higher than a full charge voltage that is higher than a predetermined value (lower limit voltage), and the charging condition is not satisfied when the voltage of the fourth power path is equal to or higher than the predetermined value while the first conversion operation is stopped. On the other hand, the charging condition is satisfied when the voltage of the fourth power path is not equal to or higher than the full charge voltage during the first conversion operation.

When the control unit 16 advances the process to step S6, the control unit 16 causes the voltage conversion unit 30 to perform a first conversion operation in step S6. The first conversion operation is a step-down operation or a step-up operation that applies an output voltage of a first target value to the fourth power path 84. The first target value is, for example, greater than the above-mentioned predetermined value. When the process of step S6 is performed, power is supplied in a flow as shown in FIG. 3. When the control unit 16 advances the process to step S7, the control unit 16 stops the voltage conversion unit 30 in step S7. FIG. 4 is an explanatory diagram showing each change in a normal state in which the voltage of the first power path 81 exceeds the low voltage threshold Vth1 (first threshold) and is less than the overvoltage threshold Vth3 (voltage threshold) that is greater than the low voltage threshold Vth1. In the example of FIG. 4, the above-mentioned start condition is satisfied at time t11, and the control of FIG. 2 is started. In this example, after the start condition is met at time t11, the first conversion operation (charging operation) is performed during periods t11-t12 and t13-t14 when the above charging condition is satisfied, and the first conversion operation (charging operation) is not performed during periods t12-t13 and t14 onwards when the above charging condition is not satisfied.

Thus, in this embodiment, when the voltage of the first power path 81 exceeds the low voltage threshold Vth1 (first threshold) and the output voltage of the storage unit 92 is equal to or lower than a predetermined value, the control unit 16 causes the voltage conversion unit 30 to perform the first conversion operation while allowing current to flow from the first power path 81 side to the voltage conversion unit 30 side in the second element unit 22.

When the control unit 16 determines in step S4 that the fourth element unit 24 is abnormal, in step S8, the control unit 16 turns the first element unit 21 on, turns the second element unit 22 on, turns the third element unit 23 off, and turns the fourth element unit 24 on. After step S8, in step S9, the control unit 16 notifies an external device (e.g., an external ECU) that the fourth element unit 24 is abnormal. In this manner, in this embodiment, when the abnormality detection unit detects an abnormality in the fourth element unit 24, the control unit 16 turns the first element unit 21 on while allowing a current to flow from the first power path 81 side to the third power path 83 side in the second element unit 22. When the control unit 16 performs an operation such as step S4, the fourth element unit 24 is turned off, and power can be supplied to the second power path via the second element unit 22 and the first element unit 21, as shown in FIG. 10. When performing the operation as shown in FIG. 10, the voltage conversion unit 30 may be always stopped, or may be controlled to perform the first conversion operation when the voltage of the fourth power path 84 drops below the predetermined value. FIG. 11 shows an example of a case where an abnormality in the fourth element unit 24 is confirmed. In the example of FIG. 11, the above-mentioned normal state is established before time t41 , and an abnormality in the fourth element unit 24 is confirmed at time t41. In this example, the first element unit 21 is kept in the OFF state until time t41, and the first element unit 21 is turned ON after time t41 to ensure a current flowing through the second power path 82 via the first element unit 21. In the representative example shown in FIG. 11, the fourth element unit 24 is kept in the ON state even after an abnormality is detected in the fourth element unit 24, but the fourth element unit 24 may be switched to the OFF state when an abnormality in the fourth element unit 24 is detected.

When the control unit 16 determines in step S2 that the voltage of the first power path 81 is equal to or higher than the overvoltage threshold (voltage threshold), the control unit 16 turns the first element unit 21 to an OFF state, turns the second element unit 22 to an ON state, turns the third element unit 23 to an ON state, and turns the fourth element unit 24 to an OFF state in step S10. After step S10, the control unit 16 performs a first conversion operation in step S11. In this way, in the present embodiment, when the voltage of the first power path 81 is equal to or higher than the overvoltage threshold (voltage threshold), the control unit 16 can cause the voltage conversion unit to perform the first conversion operation while allowing a current to flow from the power storage unit 92 side to the second power path 82 side in the third element unit 23. Then, when the control unit 16 performs operations such as steps S10 and S11, as shown in Fig. 12, the fourth element unit 24 and the first element unit 21 are turned off, and while performing the first conversion operation, power based on the power storage unit 92 can be supplied to the second power path 82 via the third element unit 23. After step S11, the control unit 16 determines whether the voltage of the first power path 81 has become less than the overvoltage threshold, and if it is determined that the voltage of the first power path 81 is equal to or greater than the overvoltage threshold, it proceeds to No in step S12 and continues the first conversion operation. If it is determined in step S12 that the voltage of the first power path 81 is less than the overvoltage threshold, it proceeds to Yes in step S12 and proceeds to step S3, and thereafter, it can proceed with the process as a normal state.

13 is an example in which an overvoltage state occurs in the first power path 81. In the example of FIG. 13, the above-mentioned normal state is in place before time 51, the voltage of the first power path 81 is equal to or greater than the overvoltage threshold (voltage threshold) at time t51, and it is determined that the voltage of the first power path 81 is less than the overvoltage threshold (voltage threshold) at time t52. In this example, from time t51 to time t52, the first conversion operation is performed, power is supplied through the third element 23, and current supply through the fourth element 24 is stopped. On the other hand, after time t52, normal operation is resumed and current can be supplied through the fourth element 24. In this manner, in this configuration, when the voltage of the first power path 81 is equal to or greater than the overvoltage threshold Vth3 (voltage threshold), the control unit 16 turns off the fourth element 24 while allowing current to flow from the storage unit 92 side to the second power path 82 side in the third element 23.

If the control unit 16 determines in step S1 that the voltage of the first power path 81 is equal to or lower than the low voltage threshold (first threshold), then in step S13, the control unit 16 turns the first element unit 21 off, turns the second element unit 22 on, turns the third element unit 23 on, and turns the fourth element unit 24 off. After step S13, the control unit 16 determines whether the failure condition is satisfied in step S14, and if the failure condition is not satisfied, performs the first conversion operation in step S15. When the control unit 16 performs an operation such as step S15, as shown in FIG. 5, the fourth element unit 24 and the first element unit 21 are turned off, and while performing the first conversion operation, power based on the storage unit 92 can be supplied to the second power path 82 via the third element unit 23. The example in FIG. 6 is an example of a case where the voltage of the first power path 81 is equal to or lower than the low voltage threshold (first threshold) and the failure determination condition is not satisfied. In the example of Fig. 6, the failure determination condition is not satisfied after the voltage of the first power path 81 becomes equal to or lower than the low voltage threshold (first threshold) at time t21, and the voltage of the first power path 81 returns to exceeding the low voltage threshold (first threshold) at time t22. In this example, the device can operate as shown in Fig. 5 from time t21 to time t22, and can operate in the same manner as the normal state described above after time t22.

If the control unit 16 determines that the failure condition is satisfied in step S14, then in step S16, the control unit 16 sets the first element unit 21 to the OFF state, the second element unit 22 to the OFF state, the third element unit 23 to the ON state, and the fourth element unit 24 to the OFF state. After step S16, the control unit 16 performs a second conversion operation in step S17. After step S17, the control unit 16 determines whether the stop condition is satisfied in step S18, and if so, continues the second conversion operation while continuing the operation of each element unit performed in step S16. If the control unit 16 determines that the stop condition is satisfied in step S18, then in step S19, the control unit 16 sets the first element unit 21 to the ON state, the second element unit 22 to the OFF state, the third element unit 23 to the OFF state, and the fourth element unit 24 to the OFF state. If the process proceeds to Yes in step S18, power is supplied as shown in Fig. 7, and if the process of step S19 is performed, power is supplied as shown in Fig. 8. The above-mentioned stop condition may be that the voltage of the third power path 83 exceeds a certain value, that a certain time has elapsed since the start of the second conversion operation in step S17, or other conditions.

Figure 9 explains an example of a case where the judgement is Yes in step S14. In the example of Figure 9, the low voltage threshold Vt1 is reached at time t31, and from time t31 onwards, the judgement is Yes in step S1 in the control of Figure 2. The period from time t31 to time t32 is a period in which the malfunction determination condition is not met, during which a No judgement is made in step S14 and the processing of step S15 is continuously performed. The period from time t32 to time t33 is a period in which the stop condition is not met when the malfunction determination condition is met, and from time t33 onwards is a period in which the stop condition is met when the malfunction determination condition is met.

In this configuration, when the voltage of the first power path 81 is equal to or lower than the first threshold value, the control unit 16 turns off the fourth element 24 while allowing current to flow from the storage unit 92 side to the second power path 82 side in the third element 23. Then, when the voltage of the first power path 81 is equal to or lower than the first threshold value and a predetermined condition is satisfied, the control unit 16 causes the voltage conversion unit 30 to perform the first conversion operation while allowing current to flow from the storage unit 92 side to the second power path 82 side in the third element 23, as shown in FIG.

In this specification, the above-mentioned predetermined condition includes the condition that the predetermined failure determination condition is not satisfied. In other words, when the voltage of the first power path 81 is equal to or lower than the first threshold, the control unit 16 operates to cause the voltage conversion unit 30 to perform the first conversion operation while allowing a current to flow from the first power path 81 side to the voltage conversion unit 30 side in the second element unit 22, on the condition that the failure determination condition is not satisfied. On the other hand, when the voltage of the first power path 81 is equal to or lower than the first threshold, the control unit 16 causes the voltage conversion unit 30 to perform the second conversion operation while blocking the current flow from the voltage conversion unit 30 side to the first power path 81 side in the second element unit 22 and allowing a current to flow from the third power path 83 side to the second power path 82 side in the first element unit 21.

When the voltage of the first power path 81 is equal to or lower than the first threshold, if a switch occurs from a state in which the failure determination condition is not satisfied to a state in which it is satisfied, the control unit 16 maintains the third element unit 23 in the on state before and after the switch, and after the switch, the control unit 16 causes the voltage conversion unit 30 to perform the second conversion operation while blocking current flow from the voltage conversion unit 30 side to the first power path 81 side in the second element unit 22 and allowing current flow from the third power path 83 side to the second power path 82 side in the first element unit 21, and if the voltage conversion unit 30 satisfies a predetermined operating condition after the switch, the control unit 16 can operate to switch the third element unit 23 to the off state.

In a representative example, the above-mentioned failure determination conditions include a condition in which a current flows from the voltage conversion unit 30 side to the first power path 81 side via the second element unit 22. In other words, in a representative example, under the condition that no current flows from the voltage conversion unit 30 side to the first power path 81 side via the second element unit 22 when the voltage of the first power path 81 is equal to or lower than the first threshold value, the process of step S15 is performed, and the control unit 16 causes the voltage conversion unit 30 to perform the first conversion operation while allowing a current to flow from the first power path 81 side to the voltage conversion unit 30 side in the second element unit 22, and allows a current to flow from the storage unit 92 side to the second power path 82 side in the third element unit 23. On the other hand, when the voltage of the first power path 81 is below the first threshold value and current flows from the voltage conversion unit 30 to the first power path 81 via the second element unit 22, processing from step S16 onwards is performed, and the second element unit 22 blocks current flow from the voltage conversion unit 30 to the first power path 81, while the first element unit 21 allows current to flow from the third power path 83 to the second power path 82, and the control unit 16 causes the voltage conversion unit 30 to perform the second conversion operation.

The failure determination condition may include a condition that the voltage of the first power path 81 is equal to or lower than a second threshold value Vth2 that is lower than the low voltage threshold value Vth1 (first threshold value). In this case, the process of step S15 is performed on the condition that the voltage of the first power path 81 is equal to or lower than the low voltage threshold value Vth1 (first threshold value) and exceeds the second threshold value Vth2, and the control unit 16 causes the voltage conversion unit 30 to perform the first conversion operation while allowing a current to flow from the first power path 81 side to the voltage conversion unit 30 side in the second element unit 22, and allows a current to flow from the storage unit 92 side to the second power path 82 side in the third element unit 23. Then, when the voltage of the first power path 81 is equal to or lower than the second threshold value, the process from step S16 onwards is performed, and the second element 22 blocks current from flowing from the voltage conversion unit 30 side to the first power path 81 side, and the control unit 16 causes the voltage conversion unit 30 to perform a second conversion operation while allowing current to flow from the third power path 83 side to the second power path 82 side in the first element 21.

The failure determination condition may include a condition in which a predetermined failure signal is given to the in-vehicle control device 10 from an external device (e.g., an external ECU) different from the in-vehicle control device 10. In this example, on the condition that the voltage of the first power path 81 is equal to or lower than the first threshold value and a failure signal is not given from the external device, the process of step S15 is performed, and the control unit 16 causes the voltage conversion unit 30 to perform the first conversion operation while allowing a current to flow from the first power path 81 side to the voltage conversion unit 30 side in the second element unit 22, and allows a current to flow from the power storage unit 92 side to the second power path 82 side in the third element unit 23. On the other hand, if the voltage of the first power path 81 is below the first threshold value and a failure signal is received from an external device, processing from step S16 onwards is performed, and the control unit 16 causes the voltage conversion unit 30 to perform a second conversion operation while blocking current flow from the voltage conversion unit 30 side to the first power path 81 side in the second element unit 22 and allowing current flow from the third power path 83 side to the second power path 82 side in the first element unit 21.

In this embodiment, during a period in which the voltage conversion unit 30 is caused to perform the first conversion operation while allowing current to flow from the power storage unit 92 side to the second power path 82 side in the third element unit 23, such as when performing the processing of step S10 or the processing of step S15, the control unit 16 sets the power supplied from the voltage conversion unit 30 to the fourth power path 84 side to be greater than the power supplied to the second power path 82 side via the third element unit 23.

5. Example of Effects The in-vehicle control device 10 can charge the power storage unit 92 while applying a desired voltage to the fourth power path 84 by making the voltage conversion unit 30 perform the first conversion operation in a state in which the second element unit 22 allows a current to flow from the first power path 81 side to the voltage conversion unit 30 side. On the other hand, the in-vehicle control device 10 can supply power to the second power path 82 while applying a desired voltage to the third power path 83 by making the voltage conversion unit 30 perform the second conversion operation in a state in which the first element unit 21 allows a current to flow from the voltage conversion unit 30 side to the second power path 82 side. In other words, the in-vehicle control device 10 can adjust the charging voltage when charging the power storage unit 92 and the discharging voltage when discharging the power storage unit 92 with a simpler configuration, and in some cases, the second element unit 22 can block the current from flowing from the voltage conversion unit 30 side to the first power path 81 side. Furthermore, since the third element unit 23 is provided and can allow a current to flow from the power storage unit 92 side to the second power path 82 side, the power storage unit 92 can be discharged via a path different from the path that adjusts the voltage by the voltage conversion unit 30. Furthermore, since the third element unit 23 can block a current from flowing from the second power path 82 side to the power storage unit 92 side, in some cases, it is possible to block a current from flowing from the second power path 82 side to the power storage unit 92 via the third element unit 23.

In the in-vehicle control device 10, the fourth element unit 24 can allow current to flow from the first power path 81 to the second power path 82, so that power based on the power supply unit 91 can be directly supplied to the second power path 82 via the fourth element unit 24. On the other hand, in some cases, the fourth element unit 24 can block current from flowing from the second power path 82 to the first power path 81.

When the voltage of the first power path 81 exceeds the first threshold, the in-vehicle control device 10 turns on the fourth element 24, thereby suppressing loss and directly supplying power based on the power supply unit 91 to the second power path 82. On the other hand, when the voltage of the first power path 81 is equal to or lower than the first threshold, the control unit 16 can turn off the fourth element 24 while allowing current to flow from the storage unit 92 side to the second power path 82 side in the third element 23. This makes it possible to flow a discharge current from the storage unit 92 to the second power path 82 via the third element 23 while suppressing the influence of the first power path 81 on the second power path 82 via the fourth element 24.

In the in-vehicle control device 10, when the abnormality detection unit detects an abnormality in the fourth element unit 24, the control unit 16 can turn the first element unit 21 on while allowing current to flow from the first power path 81 to the third power path 83 in the second element unit 22, so that power can be supplied from the first power path 81 to the second power path 82 using the path of the second element unit 22 and the first element unit 21. On the other hand, the first element unit 21 can also be turned off, in which case it is possible to prevent current from flowing from the second power path 82 to the third power path 83 via the first element unit 21.

When the voltage of the first power path 81 is large enough to exceed the first threshold but not large enough to reach the voltage threshold, the vehicle control device 10 can supply power based on the power supply unit 91 directly to the second power path 82 while suppressing loss by turning on the fourth element unit 24. On the other hand, when the voltage of the first power path 81 rises too much to the extent that it is equal to or greater than the voltage threshold, the fourth element unit 24 can be turned off while allowing current to flow from the storage unit 92 side to the second power path 82 side in the third element unit 23. Therefore, a discharge current can be flowed from the storage unit 92 to the second power path 82 via the third element unit 23 while suppressing the influence of the overvoltage of the first power path 81 from reaching the second power path 82 via the fourth element unit 24.

Even if the voltage of the first power path 81 drops below the first threshold value, if a specified condition is met, the in-vehicle control device 10 can cause the voltage conversion unit 30 to perform a first conversion operation to supply power to the storage unit 92.In this way, while supplying power to the storage unit 92, it can also supply power to the second power path 82 via the third element unit 23.

Even if the voltage of the first power path 81 drops below the first threshold, the vehicle control device 10 allows current to flow to the voltage conversion unit 30 through the second element unit 22, and causes the voltage conversion unit 30 to perform the first conversion operation, thereby charging the power storage unit 92, provided that the failure determination condition is not satisfied. On the other hand, when the failure determination condition is satisfied, the vehicle control device 10 can supply the second power path 82 with a voltage adjusted based on the voltage conversion operation of the voltage conversion unit 30 while blocking backflow to the first power path 81.

When the voltage of the first power path 81 is equal to or lower than the first threshold value and the failure determination condition is not satisfied, the vehicle control device 10 can quickly supply power from the storage unit 92 to the second power path 82 by turning on the third element unit 23. When the voltage of the first power path 81 is equal to or lower than the first threshold value and the failure determination condition is switched from a state in which the failure determination condition is not satisfied to a state in which the failure determination condition is satisfied, after the switching, the power whose voltage has been adjusted by the second conversion operation can be supplied to the second power path 82 via the third power path 83 and the first element unit 21 while preventing reverse flow to the first power path 81 side. Moreover, since the vehicle control device 10 can maintain the third element unit 23 in the on state before and after the switching, even if the rise of the output of the voltage conversion unit 30 is slow after the switching, the power supply from the storage unit 92 to the second power path 82 via the third element unit 23 can be continued. Furthermore, this in-vehicle control device 10 can narrow down the discharge path to the path of the first element unit 21 among the first element unit 21 and the third element unit 23 by switching the third element unit 23 to the off state when the voltage conversion unit 30 satisfies predetermined operating conditions after switching.

When the voltage of the first power path 81 is equal to or lower than the first threshold value, the vehicle control device 10 can make the voltage conversion unit 30 perform the first conversion operation and charge the power storage unit 92 after confirming that no current flows to the first power path 81 side through the second element unit 22, i.e., that there is a high possibility that a ground fault has not occurred in the first power path 81. The vehicle control device 10 can then perform discharging through the third element unit 23 in parallel with the power supply to the power storage unit 92 side by the first conversion operation. On the other hand, when the voltage of the first power path 81 is equal to or lower than the first threshold value and a current flows to the first power path 81 side through the second element unit 22, i.e., when there is a possibility that a ground fault has occurred in the first power path 81, the second element unit 22 can block the current from flowing to the first power path 81 side, thereby suppressing the influence of the ground fault from reaching the third power path 83 side. Then, by having the voltage conversion unit 30 perform the second conversion operation while allowing current to flow toward the second power path 82 in the first element portion 21, it is possible to supply power whose voltage has been adjusted by the voltage conversion unit 30 to the second power path 82 while suppressing the effects of ground faults.

When the voltage of the first power path 81 is equal to or lower than the first threshold, the vehicle control device 10 can make the voltage conversion unit 30 perform the first conversion operation and charge the power storage unit 92 after confirming that the voltage of the first power path 81 exceeds the second threshold, i.e., that the voltage of the first power path 81 is not too low. Then, the vehicle control device 10 can perform discharging through the third element unit 23 in parallel with the power supply to the power storage unit 92 side by the first conversion operation. On the other hand, when the voltage of the first power path 81 is equal to or lower than the second threshold, i.e., when the voltage of the first power path 81 is too low, the second element unit 22 can block the current from flowing to the first power path 81 side, so that even if a ground fault occurs in the first power path 81, the influence of the ground fault on the third power path 83 side can be suppressed. Then, by having the voltage conversion unit 30 perform the second conversion operation while allowing current to flow toward the second power path 82 in the first element portion 21, it is possible to supply power whose voltage has been adjusted by the voltage conversion unit 30 to the second power path 82 while suppressing the effects of voltage drop in the first power path 81.

When the voltage of the first power path 81 is equal to or lower than the first threshold, the vehicle control device 10 can make the voltage conversion unit 30 perform the first conversion operation and charge the power storage unit 92 after confirming that no fault signal has been given from an external device. The vehicle control device 10 can discharge the power through the third element unit 23 in parallel with the power supply to the power storage unit 92 side by the first conversion operation. On the other hand, when the voltage of the first power path 81 is equal to or lower than the first threshold and a fault signal is generated, the voltage conversion unit 30 can perform the second conversion operation while blocking the current flow to the first power path 81 side in the second element unit 22 and allowing the current flow to the second power path 82 side in the first element unit 21. Therefore, even if a ground fault or the like occurs in the first power path 81 when a fault signal is generated, the voltage of the voltage conversion unit 30 can be adjusted to supply power to the second power path 82 while suppressing the influence of the ground fault or the like.

When the in-vehicle control device 10 performs the first conversion operation and the discharge via the third element unit 23 in parallel, the charging power based on the first conversion operation can be made larger than the discharge power via the third element unit 23. Therefore, when the parallel operations are performed, it is possible to supply power to the second conductive path while more reliably securing the charging current to the storage unit 92.

The vehicle control device 10 can charge the storage unit 92 through a first conversion operation when the output voltage of the storage unit 92 falls below a predetermined value.

Second Embodiment
The following description relates to the second embodiment.
The circuit configuration of the in-vehicle control device 210 of the second embodiment shown in Fig. 14 differs from the in-vehicle control device 10 of the first embodiment in that the fourth element unit 24 is not provided, but the other circuit configuration is the same as that of the in-vehicle control device 10. The control of the in-vehicle control device 210 differs from the control of Fig. 2 in that the control of the fourth element unit 24 is omitted and the processing of steps S4, S8, and S9 is omitted, but the other control is the same as the control of Fig. 2. In the control of the in-vehicle control device 210 of Fig. 2, after step S3, the processing of step S5 is performed.

In the in-vehicle control device 210 of the second embodiment, when the voltage of the first power path 81 is in the normal state as described above and step S6 is processed, power is supplied as shown in FIG. 15. On the other hand, when the voltage of the first power path 81 is below the low voltage threshold and the failure determination condition is not satisfied, when step S15 is processed, power is supplied as shown in FIG. 16. When the voltage of the first power path 81 is below the low voltage threshold and step S16 is processed immediately after the failure determination condition is satisfied, power is supplied as shown in FIG. 17. On the other hand, when the above-mentioned stop condition is satisfied and step S19 is processed, power is supplied as shown in FIG. 18. In this way, even if the fourth element unit 24 in the configuration of FIG. 1 does not exist, control similar to that of the first embodiment can be performed.

Third Embodiment
The following description relates to the third embodiment.
The circuit configuration of the in-vehicle control device 310 of the third embodiment shown in Fig. 20 differs from that of the in-vehicle control device 10 of the first embodiment only in that the second element unit 22 of the in-vehicle control device 10 of Fig. 1 is changed to a second element unit 322, and the other circuit configurations are the same as those of the in-vehicle control device 10. The control performed by the in-vehicle control device 310 differs from the control of Fig. 2 of the first embodiment only in that the semiconductor switches 322A and 322B are both turned on when the second element unit is turned on in steps S3, S8, and S13 in Fig. 2, the semiconductor switches 322A and 322B are both turned off when the second element unit is turned off in steps S16 and S19, the second element unit 322 is turned off in step S10, and a second conversion operation is performed in step S11, and the other controls are the same as those of the control of Fig. 2 of the first embodiment.

In the vehicle control device 310 of FIG. 20, the second element unit 322 is configured to block current flow between the first power path 81 and the third power path 83 in both directions when the second element unit 322 is in an off state, and to allow current to flow from the first power path 81 to the third power path 83 when the second element unit 322 is in an on state. The semiconductor switches 322A and 322B constituting the second element unit 322 are connected in the opposite directions to each other, and both are composed of FETs. In the example of FIG. 1, the drain of the semiconductor switch 322A is shorted to the first power path 81, the drain of the semiconductor switch 322B is shorted to the third power path 83, and the source of the semiconductor switch 322A is shorted to the source of the semiconductor switch 322B. The second element unit 322 is in an off state when both the semiconductor switches 322A and 322B are in an off state. When the second element portion 322 is in the off state, current flow through the second element portion 322 is blocked in both directions, and both the flow of current from the first power path 81 side to the third power path 83 side and the flow of current from the third power path 83 side to the first power path 81 side are blocked. When the second element portion 322 is in the on state, both the semiconductor switches 322A and 322B are in the on state. When the second element portion 322 is in the on state, current flow through the second element portion 322 is permitted in both directions, and both the flow of current from the first power path 81 side to the third power path 83 side and the flow of current from the third power path 83 side to the first power path 81 side are permitted.

20, the control unit 16 turns on the second element unit 322 in step S3 on the condition that the voltage of the first power path 81 exceeds the low voltage threshold Vth1 (first threshold) and is less than the overvoltage threshold (voltage threshold) that is greater than the low voltage threshold Vth1 (first threshold) (i.e., in the case of No in step S2). On the other hand, when the control unit 16 determines in step S2 of FIG. 2 that the voltage of the first power path 81 is equal to or greater than the overvoltage threshold (voltage threshold), in step S10, the control unit 16 performs a process different from that in the example of FIG. 2, turning on the first element unit 21, turning off the second element unit 22, turning on the third element unit 23, and turning off the fourth element unit 24. Then, in the subsequent step S11, a process different from that in the example of FIG. 2 is performed, causing the voltage conversion unit 30 to perform the second conversion operation. In this way, when the voltage of the first power path 81 is equal to or higher than the overvoltage threshold (voltage threshold), the control unit 16 turns the first element unit 21 on to allow a current to flow from the third power path 83 side to the second power path 82 side in the first element unit 21, turns the second element unit 322 off, and causes the voltage conversion unit 30 to perform the second conversion operation in this state. When such an operation is performed, in a state in which the current between the first power path 81 and the third power path 83 is blocked in both directions, the voltage conversion unit 30 applies an output voltage to the third power path 83 based on the power from the power storage unit 92, and power is supplied from the third power path 83 to the second power path 82. During such a power supply operation, the fourth element unit 24 blocks the current between the first power path 81 and the second power path 82 through itself in both directions. In this example as well, the determination process of step S12 is performed after the process of step S11, and if the voltage of the first power path 81 becomes less than the above-mentioned overvoltage threshold (voltage threshold), the processes from step S3 onwards are performed.

The above-mentioned vehicle-mounted control device 310 can turn on the second element unit 22 and enable power supply from the first power path 81 side to the voltage conversion unit 30 side, provided that the voltage of the first power path 81 exceeds the low voltage threshold Vth1 (first threshold) and is less than the overvoltage threshold (voltage threshold). On the other hand, if the voltage of the first power path 81 rises too much above the overvoltage threshold (voltage threshold), the second element unit 22 can be turned off to cut off current flow from the first power path 81 side to the third power path 83 side and allow current flow from the third power path 83 side to the second power path 82 side via the first element unit 21, and the voltage conversion unit 30 can perform the second conversion operation. Specifically, the above operation is performed while the fourth element section 24 is in the off state, so that the effects of overvoltage on the first power path 81 on the second power path 82 can be prevented, while power whose voltage has been adjusted by the voltage conversion section 30 can be stably supplied to the second power path 82.

<Other embodiments>
The present disclosure is not limited to the embodiments described above and in the drawings. For example, the features of the above or later described embodiments can be combined in any combination within a range that does not contradict. In addition, any feature of the above or later described embodiments can be omitted unless it is clearly stated as essential. Furthermore, the above-mentioned embodiment may be modified as follows.

In the embodiment described above, the power storage unit 92 is provided outside the vehicle control device 10, but the power storage unit 92 may also be configured to be included in the vehicle control device 10.

The fourth element unit is turned on when the voltage of the first power path 81 exceeds the low voltage threshold Vth1 (first threshold) and is less than an overvoltage threshold Vth3 (voltage threshold) that is greater than the low voltage threshold Vth1. However, when the voltage of the first power path 81 exceeds the low voltage threshold Vth1 (first threshold), the fourth element unit may be turned on regardless of whether the voltage is less than the overvoltage threshold Vth3 (voltage threshold).

In the above-described embodiment, the first element portion 21 is composed of two FETs, but as shown in FIG. 21(A), the first element portion 21 may be composed of only a diode 191. In this case, the conductive path 181A may be electrically connected to the third power path 83, and the conductive path 181B may be electrically connected to the second power path 82. Alternatively, as shown in FIG. 21(B), the first element portion 21 may be a switch portion in which a switch element 192A (e.g., a FET) and a diode 192B are provided in series. In this case, the conductive path 182A may be electrically connected to the third power path 83, and the conductive path 182B may be electrically connected to the second power path 82. Alternatively, as shown in FIG. 21(C), the first element portion 21 may be composed of only a switch element 193 (e.g., a FET). In this case, the conductive path 183A may be electrically connected to the third power path 83, and the conductive path 183B may be electrically connected to the second power path 82. 21D , the first element portion 21 may be a switch portion 194 including a known semiconductor switch or mechanical relay other than an FET. In this case, the conductive path 184A may be electrically connected to the third power path 83, and the conductive path 184B may be electrically connected to the second power path 82.

In the first embodiment, a single FET is provided in the second element portion 22, and in the third embodiment, two FETs are provided, but this is not limited to this example. For example, the configuration of FIG. 21(A) may be applied, and the second element portion 22 may be composed of only the diode 191. In this case, the conductive path 181A may be electrically connected to the first power path 81, and the conductive path 181B may be the third power path 83. Alternatively, the configuration of FIG. 21(B) may be applied, and the second element portion 22 may be a switch portion in which a switch element 192A (e.g., a FET) and a diode 192B are provided in series. In this case, the conductive path 182A may be electrically connected to the first power path 81, and the conductive path 182B may be the third power path 83. Alternatively, the configuration of FIG. 21(D) may be applied, and the second element portion 22 may be a switch portion 194 consisting of a known semiconductor switch or mechanical relay other than a FET. In this case, the conductive path 184A may be electrically connected to the first power path 81, and the conductive path 184B may be the third power path 83.

In the above-described embodiment, two FETs are provided in the third element portion 23, but the configuration of FIG. 21(A) may be applied and the third element portion 23 may be configured only by the diode 191. In this case, the conductive path 181A may be electrically connected to the fourth power path 84, and the conductive path 181B may be electrically connected to the second power path 82. Alternatively, the configuration of FIG. 21(B) may be applied and the third element portion 23 may be a switch portion in which a switch element 192A (e.g., a FET) and a diode 192B are provided in series. In this case, the conductive path 182A may be electrically connected to the fourth power path 84, and the conductive path 182B may be electrically connected to the second power path 82. Alternatively, the configuration of FIG. 21(C) may be applied and the third element portion 23 may be configured only by the switch element 193 (e.g., a FET). 21D , the third element portion 23 may be a switch portion 194 formed of a known semiconductor switch or mechanical relay other than an FET.

In the above-described embodiment, two FETs are provided in the fourth element section 24, but the configuration of FIG. 21(A) may be applied and the fourth element section 24 may be composed of only the diode 191. In this case, the conductive path 181A may be the first power path 81, and the conductive path 181B may be the second power path 82. Alternatively, the configuration of FIG. 21(B) may be applied and the fourth element section 24 may be a switch section in which a switch element 192A (e.g., a FET) and a diode 192B are provided in series. In this case, the conductive path 182A may be the first power path 81, and the conductive path 182B may be the second power path 82. Alternatively, the configuration of FIG. 21(C) may be applied and the fourth element section 24 may be only the switch element 193 (e.g., a FET). In this case, the conductive path 183A may be the first power path 81, and the conductive path 183B may be the second power path 82. 21D may be applied, and the fourth element portion 24 may be a switch portion 194 including a known semiconductor switch or mechanical relay other than an FET. In this case, the conductive path 184A may be the first power path 81, and the conductive path 184B may be the second power path 82.

The in-vehicle control device 310 of the third embodiment is configured by changing the second element unit 22 of the in-vehicle control device 10 of the first embodiment to the second element unit 322, but the in-vehicle control device 210 may be configured to change the second element unit 22 in the same manner as the second element unit 322 in the in-vehicle control device 210 of the second embodiment. In this example, the processes other than steps S10 to S12 are performed in the same manner as the second embodiment, and the processes of steps S10 to S12 are performed in the same manner as the third embodiment, with the difference from the third embodiment being that the control of the fourth element unit is omitted.

The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is not limited to the embodiments disclosed herein, but is indicated by the scope of the claims, and is intended to include all modifications within the meaning and scope of the claims.

2: In-vehicle system 3: In-vehicle power supply system 10: In-vehicle control device 16: Control unit 21: First element unit 21A: Semiconductor switch 21B: Semiconductor switch 22: Second element unit 23: Third element unit 23A: Semiconductor switch 23B: Semiconductor switch 24: Fourth element unit 24A: Semiconductor switch 24B: Semiconductor switch 30: Voltage conversion unit 41: Voltage detection unit 43: Voltage detection unit 44: Voltage detection unit 80: Power path 81: First power path 82: Second power path 83: Third power path 84: Fourth power path 89: Conduction path 91: Power supply unit 92: Storage unit 101: Load 210: In-vehicle control device 310: In-vehicle control device 322: Second element unit 322A: Semiconductor switch 322B: Semiconductor switch

Claims (15)

An in-vehicle control device for use in an in-vehicle system including a power supply unit that supplies electric power, a power storage unit different from the power supply unit, a first power path to which a voltage based on the power supply unit is applied, a second power path that is a path for supplying electric power supplied from the first power path to a load, a third power path different from the first power path and the second power path, and a fourth power path to which a voltage based on the power storage unit is applied, the in-vehicle control device controlling power supply from the power storage unit,
a voltage conversion unit that performs a first conversion operation of converting a voltage applied to the third power path and applying an output voltage to the fourth power path, and a second conversion operation of converting a voltage applied to the fourth power path and applying an output voltage to the third power path;
A control unit that controls the voltage conversion unit;
a first element unit capable of allowing a current to flow from the voltage conversion unit side to the second power path side and blocking a current from flowing from the second power path side to the voltage conversion unit side;
a second element unit capable of allowing a current to flow from the first power path side to the voltage conversion unit side and blocking a current from flowing from the voltage conversion unit side to the first power path side;
a third element capable of allowing a current to flow from the power storage unit side to the second power path side and blocking a current from flowing from the second power path side to the power storage unit side;
An in-vehicle control device comprising: 2. The in-vehicle control device according to claim 1, further comprising a fourth element unit capable of allowing a current to flow from the first power path side to the second power path side and blocking a current from flowing from the second power path side to the first power path side. the fourth element unit is configured to, when the fourth element unit is in an off state, block a current from flowing in both directions between the first power path and the second power path through the fourth element unit, and when the fourth element unit is in an on state, allow a current to flow from the first power path to the second power path through the fourth element unit,
When the voltage of the first power path exceeds a first threshold, the control unit turns on the fourth element unit;
3. The in-vehicle control device according to claim 2, wherein when a voltage of the first power path is equal to or lower than the first threshold, the control unit turns off the fourth element while allowing a current to flow from the power storage unit side to the second power path side in the third element. an abnormality detection unit that detects an abnormality in the fourth element unit;
the first element unit is configured to, when the first element unit is in an off state, block a current from flowing in both directions between the third power path and the second power path through the first element unit, and when the first element unit is in an on state, allow a current to flow from the third power path to the second power path through the first element unit,
4. The in-vehicle control device according to claim 2, wherein when the abnormality detection unit detects an abnormality in the fourth element unit, the control unit turns on the first element unit while allowing a current to flow from the first power path side to the third power path side in the second element unit. the fourth element unit is configured to, when the fourth element unit is in an off state, block a current from flowing in both directions between the first power path and the second power path through the fourth element unit, and when the fourth element unit is in an on state, allow a current to flow from the first power path to the second power path through the fourth element unit,
When the voltage of the first power path exceeds a first threshold and is less than a voltage threshold that is greater than the first threshold, the control unit turns on the fourth element unit;
4. The in-vehicle control device according to claim 2, wherein when a voltage of the first power path is equal to or higher than the voltage threshold, the control unit turns off the fourth element while allowing a current to flow from the power storage unit side to the second power path side in the third element. 6. The in-vehicle control device according to claim 5, wherein when a voltage of the first power path is equal to or higher than the voltage threshold, the control unit causes the voltage conversion unit to perform the first conversion operation while allowing a current to flow from the storage unit side to the second power path side in the third element unit. the second element unit is configured to, when the second element unit is in an off state, block a current from flowing in both directions between the first power path and the third power path through the second element unit, and when the second element unit is in an on state, allow a current to flow from the first power path to the third power path through the second element unit,
The control unit turns on the second element unit on the condition that the voltage of the first power path exceeds a first threshold value and is less than a voltage threshold value that is greater than the first threshold value;
4. The in-vehicle control device according to claim 1, wherein when a voltage of the first power path is equal to or higher than the voltage threshold, the control unit turns off the second element unit while allowing a current to flow from the third power path side to the second power path side in the first element unit, and causes the voltage conversion unit to perform the second conversion operation. 2. The in-vehicle control device according to claim 1, wherein when a predetermined condition is satisfied while a voltage of the first power path is equal to or lower than a first threshold, the control unit causes the voltage conversion unit to perform the first conversion operation while allowing a current to flow from the storage unit side to the second power path side in the third element unit. The predetermined condition includes a condition that a predetermined malfunction determination condition is not satisfied,
When the voltage of the first power path is equal to or lower than the first threshold, the control unit causes the voltage conversion unit to perform the first conversion operation while allowing a current to flow from the first power path side to the voltage conversion unit side in the second element unit, on the condition that the failure determination condition is not satisfied;
9. The in-vehicle control device according to claim 8, wherein when the failure determination condition is satisfied when the voltage of the first power path is equal to or lower than the first threshold value, the control unit causes the voltage conversion unit to perform the second conversion operation while blocking current flow from the voltage conversion unit side to the first power path side in the second element unit and allowing current flow from the third power path side to the second power path side in the first element unit. the third element unit is configured to, when the third element unit is in an off state, block a current from flowing in both directions between the fourth power path and the second power path through the third element unit, and when the third element unit is in an on state, allow a current to flow from the fourth power path to the second power path through the third element unit,
the control unit controls at least the third element unit to be turned on and off;
10. The in-vehicle control device according to claim 9, wherein, when a voltage of the first power path is equal to or lower than a first threshold value, when a switching occurs from a state in which the failure determination condition is not satisfied to a state in which the failure determination condition is satisfied, the control unit maintains the third element unit in an on state before and after the switching, and after the switching, the control unit causes the voltage conversion unit to perform the second conversion operation while blocking a current flow from the voltage conversion unit side to the first power path side in the second element unit and allowing a current flow from the third power path side to the second power path side in the first element unit, and when the voltage conversion unit satisfies a predetermined operating condition after the switching, the control unit switches the third element unit to an off state. the failure determination condition includes a condition in which a current flows from the voltage conversion unit side to the first power path side via the second element unit,
when the voltage of the first power path is equal to or lower than the first threshold value, on the condition that no current flows from the voltage conversion unit side to the first power path side via the second element unit, the control unit causes the voltage conversion unit to perform the first conversion operation while allowing a current to flow from the first power path side to the voltage conversion unit side in the second element unit, and allows a current to flow from the power storage unit side to the second power path side in the third element unit;
11. The in-vehicle control device according to claim 9 or 10, wherein, when a voltage of the first power path is equal to or lower than the first threshold and a current flows from the voltage conversion unit side to the first power path side via the second element unit, the control unit causes the voltage conversion unit to perform the second conversion operation while blocking the current flow from the voltage conversion unit side to the first power path side in the second element unit and allowing a current to flow from the third power path side to the second power path side in the first element unit. the failure determination condition includes a condition in which a voltage of the first power path is equal to or lower than a second threshold value that is lower than the first threshold value,
on a condition that a voltage of the first power path is equal to or lower than the first threshold value and exceeds the second threshold value, the control unit causes the voltage conversion unit to perform the first conversion operation while allowing a current to flow from the first power path side to the voltage conversion unit side in the second element unit, and allows a current to flow from the power storage unit side to the second power path side in the third element unit,
11. The in-vehicle control device according to claim 9 or 10, wherein, when the voltage of the first power path is equal to or lower than the second threshold value, the control unit causes the voltage conversion unit to perform the second conversion operation while blocking current flow from the voltage conversion unit side to the first power path side in the second element unit and allowing current flow from the third power path side to the second power path side in the first element unit. the malfunction determination condition includes a condition that a predetermined malfunction signal is given to the in-vehicle control device from an external device different from the in-vehicle control device,
on the condition that the voltage of the first power path is equal to or lower than the first threshold value and the failure signal is not provided from the external device, the control unit causes the voltage conversion unit to perform the first conversion operation while allowing a current to flow from the first power path side to the voltage conversion unit side in the second element unit, and allows a current to flow from the power storage unit side to the second power path side in the third element unit,
11. The in-vehicle control device according to claim 9 or 10, wherein, when the voltage of the first power path is equal to or lower than the first threshold value and the failure signal is received from the external device, the control unit causes the voltage conversion unit to perform the second conversion operation while blocking current flow from the voltage conversion unit side to the first power path side in the second element unit and allowing current flow from the third power path side to the second power path side in the first element unit. 11. The in-vehicle control device according to claim 8, wherein during a period in which the voltage conversion unit is caused to perform the first conversion operation while allowing a current to flow from the power storage unit side to the second power path side in the third element unit, the control unit makes the power supplied from the voltage conversion unit to the fourth power path side greater than the power supplied to the second power path side via the third element unit. 11. The vehicle-mounted control device according to claim 3, wherein when the voltage of the first power path exceeds a first threshold and the output voltage of the power storage unit is equal to or lower than a predetermined value, the control unit causes the voltage conversion unit to perform the first conversion operation while allowing a current to flow from the first power path side to the voltage conversion unit side in the second element unit.

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