Vehicle power supply device, vehicle power supply control method, and vehicle power supply control program

Abstract

To provide a vehicle power supply device, vehicle power supply control method, and vehicle power supply control program that can safely return a state to a power supply state before erroneous detection after a power supply failure is erroneously detected.SOLUTION: A vehicle power supply device comprises: a first system that supplies power from a first power supply to a first load; a second system that supplies power from a second power supply to a second load; a first switch that connects the first system and the second system; a second switch that connects the second power supply to the second load; and a control unit that realizes a fail-safe state where the first switch is turned OFF and the second switch is turned ON when detecting that a power supply failure has occurred in one of the first system and the second system during a normal state where the first switch is ON and the second switch is OFF. The control unit returns the state to the normal state by turning the second switch OFF after turning the first switch ON when the occurrence of the power supply failure is not detected in a case where the first switch and the second switch are in the fail-safe state.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The disclosed embodiments relate to a vehicle power supply device, a vehicle power supply control method, and a vehicle power supply control program. [Background technology]

[0002] Conventionally, there has been a redundant power supply system that includes a first power supply and a second power supply so that if a power failure occurs while the vehicle is in motion, the vehicle can be driven to a safe location and stopped, and if a power failure occurs in one of the power supply systems, power is supplied to on-board equipment (load) from the other power supply.

[0003] For example, a redundant power supply system includes a first system that supplies power from a first power source to a first load, and a second system that supplies power from a second power source to a second load that has the same functions as the first load. If a power failure occurs in one of the first and second systems, the redundant power supply system performs fail-safe control using the other system (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-61240 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in redundant power supply systems, if a sudden increase in current or a drop in voltage due to an overload condition is mistakenly detected as a power supply failure, the system will enter fail-safe control. When a power supply failure is mistakenly detected, it is desirable to restore the power supply to the state it was in before the mistaken detection, but safety must be taken into consideration.

[0006] One aspect of the embodiment has been made in consideration of the above, and aims to provide a vehicle power supply device, a vehicle power supply control method, and a vehicle power supply control program that can safely restore the power supply state to the state before the erroneous detection of a power failure after the erroneous detection of a power failure. [Means for solving the problem]

[0007] A vehicle power supply device according to one aspect of the embodiment includes a first system, a second system, a first switch, a second switch, and a controller. The first system supplies power from a first power source to a first load. The second system supplies power from a second power source to a second load. The first switch connects the first system to the second system. The second switch connects the second power source to the second load. When the controller detects a power failure in one of the first and second systems in a normal state in which the first switch is on and the second switch is off, the controller turns off the first switch and turns on the second switch, thereby entering a fail-safe state. When the controller detects no power failure in the first and second systems in the fail-safe state in which the first and second switches are in the fail-safe state, the controller turns on the first switch and then turns off the second switch, thereby restoring the device to the normal state. [Effects of the Invention]

[0008] According to an aspect of the embodiment, a vehicle power supply device, a vehicle power supply control method, and a vehicle power supply control program can safely restore a power supply state to the state before a power failure is erroneously detected. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram showing an example of the configuration of an in-vehicle power supply device according to an embodiment. [Figure 2] FIG. 2 is an explanatory diagram showing an example of the operation of the in-vehicle power supply device according to the embodiment. [Figure 3] FIG. 3 is an explanatory diagram showing an example of the operation of the in-vehicle power supply device according to the embodiment. [Figure 4] FIG. 4 is an explanatory diagram showing an example of the operation of the in-vehicle power supply device according to the embodiment. [Figure 5] FIG. 5 is an explanatory diagram showing an example of the operation of the in-vehicle power supply device according to the embodiment. [Figure 6] FIG. 6 is an explanatory diagram showing an example of the operation of the in-vehicle power supply device according to the embodiment. [Figure 7] FIG. 7 is an explanatory diagram showing an example of the operation of the in-vehicle power supply device according to the embodiment. [Figure 8] FIG. 8 is a flowchart illustrating the switch changeover process according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of a vehicle power supply device, a vehicle power supply control method, and a vehicle power supply control program will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments described below. The following description will be given using an example of an on-board power supply device (vehicle power supply device) that is installed in a vehicle with an automatic driving function and supplies power to a load, but the on-board power supply device according to the embodiment may also be installed in a vehicle that does not have an automatic driving function.

[0011] 1 is an explanatory diagram showing an example of the configuration of an in-vehicle power supply device 1 according to an embodiment. As shown in FIG. 1, the in-vehicle power supply device 1 according to the embodiment is connected to a first load 101, a second load 102, and an automatic driving control device 104.

[0012] The first load 101 includes a steering motor, an electric brake device, an in-vehicle camera, a radar, etc. that operate during autonomous driving. The first load 101 also includes general loads such as an air conditioner, an audio system, a video system, and various lights.

[0013] The second load 102 includes at least devices that operate during autonomous driving, such as a steering motor, an electric brake device, an on-board camera, and a radar. The first load 101 and the second load 102 operate using power supplied from the on-board power supply device 1.

[0014] The automatic driving control device 104 is a control device that operates the first load 101 and the second load 102 to control the automatic driving of the vehicle.

[0015] The in-vehicle power supply device 1 is supplied with power from an externally provided first power supply 10. The in-vehicle power supply device 1 supplies the power supplied from the externally provided first power supply 10 to a first load 101 and a second load 102. The in-vehicle power supply device 1 includes a second power supply 20, a control unit 30, a charge / discharge unit 40, a first switch 41, and a second switch 42. The in-vehicle power supply device 1 also includes voltage sensors 51 and 53.

[0016] The first power source 10 includes a DC / DC converter (hereinafter referred to as "DC / DC 11") and a lead battery (hereinafter referred to as "PbB 12"). The battery of the first power source 10 may be any secondary battery other than PbB 12.

[0017] The DC / DC converter 11 is connected to a generator that converts the vehicle's regenerative energy into electric power to generate electricity, and transforms and outputs the input voltage from the generator. If the vehicle is equipped with an engine, the generator may be an alternator that converts the rotational force of the engine into electric power to generate electricity. The DC / DC converter 11 charges the PbB 12, supplies electric power to the first load 101, supplies electric power to the second load 102, and charges the second power source 20 (described later).

[0018] The first power supply 10 is connected to the first load 101 and the first switch 41. A voltage sensor 51 is connected between the first power supply 10 and the first switch 41.

[0019] The second power source 20 includes, for example, a lithium ion battery (hereinafter referred to as "LiB21"). A battery with a higher voltage than the first power source 10 is selected as the second power source 20 so that the minimum necessary voltage can be supplied even at low temperatures. The second power source 20 is a backup power source in case the first power source 10 is unable to supply power.

[0020] The second power source 20 is connected to the charge / discharge unit 40 via the second switch 42. That is, the second switch 42 connects the second power source 20 and the charge / discharge unit 40 in a manner that allows the connection and disconnection between them.

[0021] The charge / discharge unit 40 is, for example, a DC / DC converter. The charge / discharge unit 40 is connected to a first switch 41 and a second load 102. The charge / discharge unit 40 boosts the voltage of the first power source 10 to charge the second power source 20, and is turned off when charging is complete. The charge / discharge unit 40 also drops the voltage of the second power source 20 to supply power to the second load 102.

[0022] The in-vehicle power supply device 1 includes a first system 100 that supplies power from a first power source 10 to a first load 101, and a second system 200 that supplies power from a second power source 20 to a second load 102. A first switch 41 connects the first system 100 and the second system 200 in a manner that allows them to be connected or disconnected. A second switch 42 connects the second power source 20 and the second load 102 in a manner that allows them to be connected or disconnected.

[0023] In this way, the in-vehicle power supply device 1 includes the first system 100 and the second system 200. As a result, even if a power failure occurs in one of the first system 100 and the second system 200, the in-vehicle power supply device 1 can supply power using the other system, allowing the vehicle to evacuate to a safe location and stop. Note that a power failure refers to a ground fault occurring in the first system 100 or the second system 200. A phenomenon similar to a power failure can also occur when the first load 101 or the second load 102 is overloaded.

[0024] The control unit 30 includes a microcomputer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc., and various circuits. The control unit 30 includes an abnormality detection unit 31 that functions when the CPU executes a program stored in the ROM using the RAM as a work area, and a switch setting unit 32.

[0025] The abnormality detection unit 31 and the switch setting unit 32 included in the control unit 30 may be partially or entirely configured with hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0026] The abnormality detection unit 31 and the switch setting unit 32 included in the control unit 30 each realize or execute the information processing functions described below. Note that the internal configuration of the control unit 30 is not limited to the configuration shown in Fig. 1, and may be any other configuration as long as it performs the information processing described below.

[0027] The abnormality detection unit 31 detects that a power failure has occurred in one of the first system 100 and the second system 200. The abnormality detection unit 31 determines whether the voltages detected by the voltage sensors 51 and 53 are within a normal range in a normal state in which the first switch 41 is on and the second switch 42 is off. The normal range is the range indicated by the voltages detected by the voltage sensors 51 and 53 when no power failure has occurred in the first system 100 or the second system 200. For example, the normal range is a range in which the voltages detected by the voltage sensors 51 and 53 are equal to or higher than a predetermined voltage.

[0028] When the voltage detected by the voltage sensors 51, 53 is not within the normal range during normal operation, for example, when the voltage is lower than a predetermined voltage, the abnormality detection unit 31 detects that a power failure has occurred in one of the first system 100 and the second system 200.

[0029] In a normal state, if the voltages detected by the voltage sensors 51, 53 are within a normal range, the abnormality detection unit 31 detects that no power supply failure has occurred in the first system 100 and the second system 200.

[0030] When a power failure occurs in one of the first system 100 and the second system 200 and the first switch 41 is in the fail-safe state, the abnormality detection unit 31 detects whether a power failure (hereinafter referred to as a "system power failure") has occurred for each system. The fail-safe state is a state in which the first switch 41 is turned off.

[0031] Specifically, the abnormality detection unit 31 detects whether a system power failure has occurred in a pre-shutdown state immediately after a power failure occurs in one of the first system 100 and the second system 200 and the first switch 41 is turned off. The pre-shutdown state is a state in the fail-safe state in which the first switch 41 is turned off and the second switch 42 is turned on.

[0032] The abnormality detection unit 31 determines whether the voltage detected by the voltage sensor 51 is within a normal range in the pre-shutdown state. If the voltage detected by the voltage sensor 51 is not within the normal range in the pre-shutdown state, for example, if the voltage detected by the voltage sensor 51 is lower than a predetermined voltage, the abnormality detection unit 31 determines that a system power failure has occurred in the first system 100. The abnormality detection unit 31 detects the occurrence of a system power failure (ground fault) in the first system 100.

[0033] If the voltage detected by the voltage sensor 51 is within a normal range in the pre-shutdown state, for example, if the voltage detected by the voltage sensor 51 is equal to or higher than a predetermined voltage, the abnormality detection unit 31 determines that a system power supply failure has not occurred in the first system 100. The abnormality detection unit 31 detects that a system power supply failure (ground fault) has not occurred in the first system 100.

[0034] In the pre-shutdown state, the abnormality detection unit 31 determines whether the voltage detected by the voltage sensor 53 is within a normal range. If the voltage detected by the voltage sensor 53 is not within the normal range in the pre-shutdown state, for example, if the voltage detected by the voltage sensor 53 is lower than a predetermined voltage, the abnormality detection unit 31 determines that a system power failure has occurred in the second system 200. The abnormality detection unit 31 detects the occurrence of a system power failure (ground fault) in the second system 200.

[0035] If the voltage detected by the voltage sensor 53 is within a normal range in the pre-shutdown state, for example, if the voltage detected by the voltage sensor 53 is equal to or higher than a predetermined voltage, the abnormality detection unit 31 determines that a system power supply failure has not occurred in the second system 200. The abnormality detection unit 31 detects that a system power supply failure (ground fault) has not occurred in the second system 200.

[0036] In the pre-shutdown state, if a system power failure has not occurred in the first system 100 and the second system 200, the abnormality detection unit 31 determines that recovery from the power failure has occurred. In other words, the abnormality detection unit 31 determines that the detection of the power failure is an erroneous detection caused by the first load 101 or the second load 102 being in an overload state.

[0037] The switch setting unit 32 sets the first switch 41 to on or off. The switch setting unit 32 sets the second switch 42 to on or off. When the abnormality detection unit 31 does not detect a power supply failure, the switch setting unit 32 turns on the first switch 41 and turns off the second switch 42, thereby setting the state of each switch to a normal state. In the normal state, when the charge amount (SOC (State of Charge)) of the second power supply 20 falls below a predetermined amount, the switch setting unit 32 turns on the second switch 42. This causes the second power supply 20 to be charged.

[0038] When a power failure is detected by the abnormality detection unit 31, the switch setting unit 32 turns off the first switch 41 and sets the state of the first switch 41 to a fail-safe state. Furthermore, when a power failure is detected by the abnormality detection unit 31 and the switch setting unit 32 sets the state of the first switch 41 to the fail-safe state, the switch setting unit 32 turns on the second switch 42 and sets the state of each switch to a pre-shutoff state.

[0039] In the pre-shutdown state, if a system power failure is detected in the first system 100 or the second system 200, the switch setting unit 32 sets the state of each switch to the main shutdown state. The main shutdown state is the state of each switch when a system power failure is detected in the fail-safe state and it is determined that the power failure is not an erroneous detection.

[0040] Specifically, when a system power failure is detected in the first system 100, the switch setting unit 32 turns off the first switch 41 and turns on the second switch 42, thereby setting the states of the switches to a first main interruption state. As a result, power is supplied from the second power source 20 to the second load 102 via the second system 200, and evacuation travel control is performed by the power supply from the second system 200.

[0041] Furthermore, when a system power failure is detected in the second system 200, the switch setting unit 32 turns off the first switch 41 and the second switch 42, thereby setting the states of the switches to a second main interruption state. As a result, power is supplied from the first power source 10 to the first load 101 via the first system 100, and evacuation travel control is performed by the power supply from the first system 100.

[0042] In the pre-shutdown state, if a system power failure is not detected in the first system 100 and if a system power failure is not detected in the second system 200, the switch setting unit 32 sets the state of each switch to the normal state. In the pre-shutdown state, if a system power failure is not detected in each system, the switch setting unit 32 turns on the first switch 41 and then turns off the second switch 42, thereby returning the state of each switch from the fail-safe state to the normal state. When returning to the normal state, turning on the first switch 41 and then turning off the second switch 42 can prevent a momentary interruption of power to the second load 102.

[0043] Next, an example of the operation of the in-vehicle power supply device 1 will be described with reference to FIGS.

[0044] 2 to 7 are explanatory diagrams showing an example of the operation of the in-vehicle power supply device 1 according to the embodiment. As shown in FIG. 2, when no power supply failure is detected, the in-vehicle power supply device 1 turns on the first switch 41 and turns off the second switch 42, thereby placing each switch in a normal state. This causes power to be supplied from the first power source 10 to the first load 101 and the second load 102. For example, 50% torque is output from each of the first load 101 and the second load 102. Furthermore, no power is supplied from the second power source 20 to the second load 102.

[0045] The in-vehicle power supply device 1 performs fail-safe control when a system power failure is detected in the first system 100 or the second system 200. The fail-safe control is a control that limits the output and functions of the first load 101 or the second load 102 connected to the system that is not experiencing a system power failure, compared to normal times when a system power failure is not detected. For example, under fail-safe control, 50% of the torque is output. This allows the vehicle to perform evacuation running even if a system power failure occurs in the first system 100 or the second system 200.

[0046] Furthermore, if a grid power failure is detected during autonomous driving, the autonomous driving control device 104 performs evacuation control to a safe place where the vehicle can stop, such as a roadside, using the first load 101 or the second load 102 connected to the grid that is not experiencing a power failure. Then, the autonomous driving control device 104 prohibits autonomous driving control after the vehicle has made an evacuation run and stopped. This makes it possible to prevent accidents caused by autonomous driving during a grid power failure.

[0047] An example of operation when a power failure is detected in the first system 100 or the second system 200 will be described below.

[0048] For example, in the in-vehicle power supply device 1, a ground fault 110 may occur in the first system 100, as shown in Fig. 3. When the ground fault 110 occurs in the first system 100, an overcurrent flows from the first power source 10 to the ground-fault point, causing a sudden drop in the voltage of the first system 100 and the second system 200, and the occurrence of a power supply failure is detected.

[0049] 4, in the in-vehicle power supply device 1, a ground fault 110 may occur in the second system 200. When a ground fault 110 occurs in the second system 200 in the in-vehicle power supply device 1, an overcurrent flows from the first power source 10 to the ground fault point, the voltages of the first system 100 and the second system 200 drop suddenly, and the occurrence of a power supply failure is detected.

[0050] Furthermore, in the in-vehicle power supply device 1, if the first load 101 or the second load 102 is in an overload state, the voltage of the first system 100 and the second system 200 may also drop suddenly. Therefore, in the in-vehicle power supply device 1, if the first load 101 or the second load 102 is in an overload state, the occurrence of a power supply failure is detected.

[0051] When a power failure is detected in the first system 100 or the second system 200, the in-vehicle power supply device 1 turns off the first switch 41, placing the first switch 41 in a fail-safe state, as shown in Fig. 5. The in-vehicle power supply device 1 also turns on the second switch 42, placing each switch in a pre-shutdown state. This causes power to be supplied from the second power source 20 to the second load 102 by the second system 200.

[0052] In the pre-shutdown state, the in-vehicle power supply device 1 detects the voltage in the first system 100 using the voltage sensor 51. If the detected voltage is not within the normal range, the in-vehicle power supply device 1 determines that a system power failure (ground fault 110) has occurred in the first system 100, and detects the occurrence of a system power failure in the first system 100. Then, as shown in FIG. 6 , the in-vehicle power supply device 1 turns off the first switch 41 and turns on the second switch 42, bringing the states of the switches into a first main shutdown state. As a result, power is supplied from the second power source 20 to the second load 102 via the second system 200, and fail-safe control using the second load 102 is executed.

[0053] In the pre-shutdown state, the in-vehicle power supply device 1 detects the voltage in the second system 200 using the voltage sensor 53. If the detected voltage is not within the normal range, the in-vehicle power supply device 1 determines that a system power failure (ground fault 110) has occurred in the second system 200, and detects the occurrence of a system power failure in the second system 200. Then, as shown in FIG. 7 , the in-vehicle power supply device 1 turns off the first switch 41 and the second switch 42. As a result, the power supply from the second power source 20 is stopped, and power is supplied from the first power source 10 to the first load 101 via the first system 100, and fail-safe control using the first load 101 is executed.

[0054] If the in-vehicle power supply device 1 determines in the pre-shutdown state that a system power failure has not occurred in the first system 100 or the second system 200, it determines that the power failure is an erroneous detection. The in-vehicle power supply device 1 determines that a power failure has been detected when the first load 101 or the second load 102 enters an overload state, causing a temporary drop in voltage. The in-vehicle power supply device 1 turns on the first switch 41 and then turns off the second switch 42, returning the states of the switches from the pre-shutdown state to the normal state shown in FIG. 2. When returning to the normal state, turning on the first switch 41 and then turning off the second switch 42 prevents a momentary interruption in the power supply to the second load 102.

[0055] Next, the switch changeover process according to the embodiment will be described with reference to Fig. 8. Fig. 8 is a flowchart illustrating the switch changeover process according to the embodiment.

[0056] The in-vehicle power supply device 1 determines (S100) whether a power failure has been detected in the first system 100 or the second system 200. If a power failure has not been detected in the first system 100 or the second system 200 (S100: No), the in-vehicle power supply device 1 ends the current processing.

[0057] When a power failure is detected in the first system 100 or the second system 200 (S100: Yes), the in-vehicle power supply device 1 sets each switch to a pre-shutdown state (S101). Specifically, the in-vehicle power supply device 1 turns off the first switch 41 to set the first switch 41 to a fail-safe state, and turns on the second switch 42 to set each switch to a pre-shutdown state.

[0058] The in-vehicle power supply device 1 determines whether a system power failure has been detected in the first system 100 (S102). If a system power failure has been detected in the first system 100 and a ground fault has occurred in the first system 100 (S102: Yes), the in-vehicle power supply device 1 sets the states of the switches to a first main interruption state (S103). Specifically, the in-vehicle power supply device 1 turns off the first switch 41 and turns on the second switch 42.

[0059] If a system power supply failure is not detected in the first system 100 (S102: No), the in-vehicle power supply device 1 determines whether a system power supply failure is detected in the second system 200 (S104).

[0060] When a system power failure is detected in the second system 200 and a ground fault occurs in the second system 200 (S104: Yes), the in-vehicle power supply device 1 sets the states of the switches to the second main shutoff state (S105). Specifically, the in-vehicle power supply device 1 turns off the first switch 41 and turns off the second switch 42.

[0061] If a system power failure is not detected in the second system 200 (S104: No), that is, if a system power failure is not detected in the first system 100 or the second system 200, the in-vehicle power supply device 1 sets the states of the switches to the normal state (S106). Specifically, the in-vehicle power supply device 1 turns on the first switch 41 and turns off the second switch 42.

[0062] The order of the process for determining whether a system power failure has occurred in the first system 100 (S102) and the process for determining whether a system power failure has occurred in the second system 200 (S104) may be reversed.

[0063] The in-vehicle power supply device 1 according to this embodiment includes a first system 100, a second system 200, a first switch 41, a second switch 42, an abnormality detection unit 31, and a switch setting unit 32. The first system 100 supplies power from a first power source 10 to a first load 101. The second system 200 supplies power from a second power source 20 to a second load 102. The first switch 41 connects the first system 100 and the second system 200. The second switch 42 connects the second power source 20 and the second load 102. The abnormality detection unit 31 detects a power failure in one of the first system 100 and the second system 200. When no power failure is detected, the switch setting unit 32 turns on the first switch 41 and turns off the second switch 42 to establish a normal state, and when a power failure is detected, the switch setting unit 32 turns off the first switch 41 to establish a fail-safe state. The abnormality detection unit 31 detects whether or not a system power failure has occurred for each system after the first switch 41 is set to the fail-safe state. If a system power failure is not detected in each system after the first switch 41 is set to the fail-safe state, the switch setting unit 32 sets each switch to the normal state.

[0064] As a result, if a system power failure is not detected in any system after a power failure is detected, each switch returns to its normal state. Therefore, the in-vehicle power supply device 1 returns each switch to its normal state after confirming that no system power failure has occurred in any system, thereby improving safety when returning each switch to its normal state. Furthermore, for example, if the detected power failure is due to an overload state of the first load 101 or the second load 102 and is a power failure that has been erroneously detected, the in-vehicle power supply device 1 returns each switch to its normal state. Therefore, if a power failure is erroneously detected, the in-vehicle power supply device 1 can allow the vehicle to drive normally without any restrictions on driving functions.

[0065] The switch setting unit 32 turns on the second switch 42 in the fail-safe state. The abnormality detection unit 31 detects the occurrence of a system power failure in the first system 100 if the voltage of the first system 100 is not within a normal range after the first switch 41 is set to the fail-safe state. The abnormality detection unit 31 detects the occurrence of a system power failure in the second system 200 if the voltage of the second system 200 is not within a normal range after the first switch 41 is set to the fail-safe state and the second switch 42 is turned on.

[0066] This allows the in-vehicle power supply device 1 to detect the occurrence of a system power supply failure in each system, and therefore the in-vehicle power supply device 1 can accurately detect the occurrence of a system power supply failure in each system.

[0067] If the voltage of the first system 100 is within the normal range after the first switch 41 is set to the fail-safe state, the abnormality detection unit 31 does not detect the occurrence of a system power failure in the first system 100. If the voltage of the second system 200 is within the normal range after the first switch 41 is set to the fail-safe state and the second switch 42 is turned on, the abnormality detection unit 31 does not detect the occurrence of a system power failure in the second system 200.

[0068] This allows the in-vehicle power supply device 1 to detect that no system power supply failure has occurred in each system, thereby improving safety when returning each switch to a normal state.

[0069] The in-vehicle power supply device 1 according to the modified example may determine that a system power failure has occurred in the first system 100 when the voltage detected by the voltage sensor 51 is not within the normal range for a predetermined consecutive time in the pre-shutdown state. The in-vehicle power supply device 1 according to the modified example may determine that a system power failure has not occurred in the first system 100 when the voltage detected by the voltage sensor 51 is within the normal range for a predetermined consecutive time in the pre-shutdown state.

[0070] Furthermore, the in-vehicle power supply device 1 according to the modified example may determine that a system power failure has occurred in the second system 200 when the voltage detected by the voltage sensor 53 is not within the normal range for a predetermined consecutive time in the pre-shutdown state. Furthermore, the in-vehicle power supply device 1 according to the modified example may determine that a system power failure has not occurred in the second system 200 when the voltage detected by the voltage sensor 53 is within the normal range for a predetermined consecutive time in the pre-shutdown state.

[0071] The predetermined time is a time set in advance, and is a time that allows accurate determination of whether or not there is a power supply failure in each system. The predetermined time may be set for each system.

[0072] In the pre-shutdown state, the in-vehicle power supply device 1 according to the modified example counts the time during which the voltage detected by the voltage sensors 51, 53 is within the normal range, or the time during which the voltage detected by the voltage sensors 51, 53 is not within the normal range. If the voltage changes beyond a predetermined voltage before the counted time reaches the predetermined time, the in-vehicle power supply device 1 according to the modified example resets the counted time. This allows the in-vehicle power supply device 1 according to the modified example to accurately detect whether a system power supply failure has occurred in each system.

[0073] The in-vehicle power supply device 1 according to the modified example may use a current sensor to detect the current flowing in each system, and may detect the occurrence of a power supply failure or a system power supply failure based on the detected current. When a ground fault occurs, the current detected by the current sensor increases rapidly. The in-vehicle power supply device 1 according to the modified example detects the occurrence of a power supply failure or a system power supply failure when the current detected by the current sensor is equal to or greater than a predetermined current.

[0074] Further advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0075] 1 On-vehicle power supply 10 1st power supply 20 2nd power supply 30 Control Unit 31 Abnormality detection unit 32 Switch setting section 41 First Switch 42 Second Switch 51, 53 Voltage sensor 100 1st system 200 2nd system 101 1st load 102 2nd load

Claims

1. a first system that supplies power from a first power source to a first load; a second system that supplies power from a second power source to a second load; a first switch connecting the first system and the second system; a second switch connecting the second power supply and the second load; a control unit that, when detecting a power failure in one of the first system and the second system in a normal state in which the first switch is on and the second switch is off, sets the first switch to an off-state and the second switch to an on-state fail-safe state; Equipped with When the first switch and the second switch are in a fail-safe state and the occurrence of the power supply failure is not detected, the control unit turns on the first switch and then turns off the second switch to return to the normal state. Vehicle power supply.

2. The second load includes a load that operates during automatic driving of the vehicle. The vehicle power supply device according to claim 1 .

3. The control unit The fail-safe state may be a pre-shutoff state or a main shutoff state, When the occurrence of the power supply failure is detected in the normal state, a pre-shutdown state is entered; A process for detecting the occurrence of the power failure is performed in the pre-shutdown state, and if the power failure is detected, the state is switched to the main shutdown state, and if the power failure is not detected, the state is switched to the normal state.

3. The vehicle power supply device according to claim 1 or 2.

4. A vehicle power supply control method in which a control device controls a vehicle power supply device including: a first system that supplies power from a first power source to a first load; a second system that supplies power from a second power source to a second load; a first switch that connects the first system and the second system; and a second switch that connects the second power source and the second load, a fail-safe state is established in which the first switch is turned off and the second switch is turned on when a power failure is detected in one of the first system and the second system in a normal state in which the first switch is turned on and the second switch is turned off; If the occurrence of the power supply failure is not detected when the first switch and the second switch are in a fail-safe state, the normal state is restored by turning on the first switch and then turning off the second switch. Vehicle power supply control method.

5. A vehicle power supply control program that causes a computer to execute control of a vehicle power supply device including: a first system that supplies power from a first power source to a first load; a second system that supplies power from a second power source to a second load; a first switch that connects the first system and the second system; and a second switch that connects the second power source and the second load, a fail-safe state is established in which the first switch is turned off and the second switch is turned on when a power failure is detected in one of the first system and the second system in a normal state in which the first switch is turned on and the second switch is turned off; If the occurrence of the power supply failure is not detected when the first switch and the second switch are in a fail-safe state, the normal state is restored by turning on the first switch and then turning off the second switch. Vehicle power control program.

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