Power supply control device, load device, and power supply control program

Abstract

To provide a power supply control device, a load device, and a power supply control program enabling efficient fail-safe control while extending a sub-battery's life during fail-safe control.SOLUTION: A power supply control device according to an embodiment includes a controller. The controller performs fail-safe control by supplying power from a sub-battery to a load in the event of a main battery failure. The controller supplies power to the active load and stops power supply to an inactive load when performing fail-safe control.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] A power supply control device that controls a redundant power supply system performs fail-safe control using a sub-battery in the event of a main battery failure. However, since the power of the sub-battery is limited, it is necessary to make the power of the sub-battery last as long as possible during fail-safe control.

[0003] Therefore, there is a technology that assigns priorities to loads in advance, and during fail-safe control using a sub-battery, as the power of the sub-battery decreases, power supply to loads with lower priority is stopped, thereby extending the life of the sub-battery's power (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-42332 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned prior art, since the priority is fixed in advance, if there are loads with high priority but not in operation and loads with low priority but in operation, power supply to the low-priority loads that are in operation is stopped before power supply to the high-priority loads that are not in operation.

[0006] As a result, not only is unnecessary dark current supplied to high-priority loads that are not in operation, consuming power from the sub-battery, but operating low-priority loads also stop operating, making it impossible to perform efficient fail-safe control.

[0007] One aspect of the embodiment has been made in consideration of the above, and aims to provide a power supply control device, a load device, and a power supply control program that enable efficient fail-safe control while prolonging the life of the sub-battery's power during fail-safe control. [Means for solving the problem]

[0008] According to one aspect of the embodiment, a power supply control device includes a controller. The controller performs fail-safe control to supply power from a sub-battery to a load when a main battery fails. When performing the fail-safe control, the controller supplies power to an operating load and stops power supply to an inactive load. [Effects of the Invention]

[0009] In a power supply control device, load device, and power supply control program according to one aspect of the embodiment, power supply to loads that are not operating is stopped during fail-safe control, and power is supplied to loads that are operating, thereby enabling efficient fail-safe control while extending the life of the sub-battery's power. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is an explanatory diagram illustrating an example of the configuration of a power supply control device according to the first embodiment. [Figure 2] FIG. 2 is an explanatory diagram illustrating an example of the operation of the power supply control device according to the first embodiment. [Figure 3] FIG. 3 is an explanatory diagram illustrating an example of the operation of the power supply control device according to the first embodiment. [Figure 4] FIG. 4 is an explanatory diagram illustrating an example of the operation of the power supply control device according to the first embodiment. [Figure 5] FIG. 5 is an explanatory diagram of an example of power supply control according to the first embodiment. [Figure 6] FIG. 6 is a flowchart showing an example of processing executed by the controller according to the first embodiment. [Figure 7] FIG. 7 is an explanatory diagram of an example of power supply control according to the second embodiment. [Figure 8] FIG. 8 is a flowchart showing an example of processing executed by the controller according to the second embodiment. [Figure 9] FIG. 9 is an explanatory diagram of an example of power supply control according to the third embodiment. [Figure 10] FIG. 10 is a flowchart illustrating an example of processing executed by the controller according to the third embodiment. [Figure 11] FIG. 11 is a flowchart illustrating an example of processing executed by a load device. [Figure 12] FIG. 12 is a flowchart illustrating an example of processing executed by a load device. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of a power supply control device, a load device, and a 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 a power supply control device that is installed in a vehicle with an autonomous driving function and supplies power to a load, but the power supply control device according to the embodiment may also be installed in a vehicle that does not have an autonomous driving function.

[0012] In addition, although the following description will be given of a case where the vehicle in which the power supply control device is installed is an electric vehicle or a hybrid vehicle, the vehicle in which the power supply control device is installed may also be an engine vehicle that runs on an internal combustion engine.

[0013] 1. First Embodiment 1-1. Power supply control device configuration 1 is an explanatory diagram showing an example of the configuration of a power supply control device 1 according to the first embodiment. The power supply control device 1 according to the first embodiment is connected to a main battery 10, a DC / DC converter 11 (hereinafter referred to as "DCC 11"), a first FOP (fail-safe operation) load 101, a second FOP load 102, and a non-FOP load 103. Furthermore, the power supply control device 1 is connected to an automatic driving control device 201 and an operation device 202.

[0014] The main battery 10 is, for example, a lead battery. However, the main battery 10 may be any secondary battery other than a lead battery. The main battery 10 is a power source that mainly supplies power to the first FOP load 101, the second FOP load 102, the non-FOP load 103, and the like.

[0015] The DCC 11 is connected to a high-voltage battery 12. The high-voltage battery 12 is a vehicle drive battery that supplies power to a motor that drives the vehicle. The high-voltage battery 12 is, for example, a lithium-ion battery.

[0016] The DCC 11 steps down the voltage of the high-voltage battery 12 to charge the main battery 10 and a sub-battery 20 (described later). The DCC 11 also steps down the voltage of the high-voltage battery 12 to supply power to a first FOP load 101, a second FOP load 102, a non-FOP load 103, and the like.

[0017] When the DCC 11 is mounted on an engine vehicle, it is connected to an alternator that converts the vehicle's regenerative energy into electric power to generate electricity, and transforms and outputs the input voltage input from the generator.

[0018] The first FOP load 101 and the second FOP load 102 are devices used for fail-safe control that causes the vehicle to run to safety using the power of the sub-battery 20 when, for example, the main battery 10 fails. The first FOP load 101 and the second FOP load 102 are also devices that are used when autonomous driving is performed.

[0019] The first FOP load 101 is a load for fail-safe control that has a higher priority in the fail-safe control than a predetermined priority. The fail-safe control is a control for stopping a running vehicle in a safe place when a power failure occurs.

[0020] Therefore, the first FOP load 101 includes devices related to steering and braking of the vehicle, such as an electric steering device, an electric braking device, radar, a sensor, and an on-board camera.

[0021] The second FOP load 102 is a load whose priority in fail-safe control is equal to or lower than a predetermined priority. In general, the vehicle rarely accelerates during evacuation driving. Furthermore, it is desirable to notify the vehicle occupants and surrounding areas that the vehicle is being evacuation driven. Therefore, the second FOP load 102 includes an electric accelerator device, exterior lamps (hazard lamps, headlights, brake lights, etc.), and warning devices. The priorities of the first FOP load 101 and the second FOP load 102 are stored in a memory area of ​​the power supply control device 1.

[0022] The non-FOP loads 103 include loads that do not directly affect fail-safe control and autonomous driving, such as air conditioners, power windows, A / V (audio / video) devices, power outlets inside the vehicle, and power outlets outside the vehicle.

[0023] The first FOP load 101 is connected to the first system 110 and the second system 120 for each type of load (electric steering device, electric brake device, etc.), but for simplicity, only one first FOP load 101 is shown in Fig. 1. The same applies to the second FOP load 102 and the non-FOP load 103.

[0024] The automatic driving control device 201 is a control device that controls automatic driving of a vehicle by activating the first FOP load 101 and the second FOP load 102. Furthermore, when power supply from the main battery 10 becomes impossible, the automatic driving control device 201 uses power from the sub-battery 20 to activate the first FOP load 101 and the second FOP load 102, thereby performing fail-safe control.

[0025] The automatic driving control device 201 can also perform fail-safe control by operating only the first FOP load 101. The automatic driving control device 201 is supplied with power from the main battery 10 and the sub-battery 20 and operates.

[0026] The operation devices 202 are devices used by the vehicle driver or the automatic driving control device 201 to drive the vehicle. The operation devices 202 include, for example, a steering mechanism, an accelerator mechanism, a brake mechanism, and a shift mechanism. Each operation device 202 includes a sensor that detects the amount of operation when operated by the driver or the automatic driving control device 201.

[0027] The power supply control device 1 is supplied with power from an externally provided main battery 10. The power supply control device 1 can supply the power supplied from the externally provided main battery 10 to a first FOP load 101, a second FOP load 102, and a non-FOP load 103.

[0028] The power supply control device 1 includes a first system 110 and a second system 120. The first system 110 is a system capable of supplying power from the main battery 10 to a first FOP load 101, a second FOP load 102, and a non-FOP load 103. The second system 120 is a system capable of supplying power from a sub-battery 20 (described later) to the first FOP load 101, the second FOP load 102, and the non-FOP load 103.

[0029] The first system 110 and the second system 120 are connected by an inter-system line 130. The inter-system line 130 is provided with an inter-system switch 32 that can connect and disconnect the first system 110 and the second system 120.

[0030] The power supply control device 1 includes a sub-battery 20, a DCC 21, a plurality of switches 31 to 38, a first voltage sensor 51, a second voltage sensor 52, a first current sensor 61, a second current sensor 62, a third current sensor 63, a controller 3, and a power supply circuit 30.

[0031] The sub-battery 20 is, for example, a lithium ion battery. The sub-battery 20 is a backup power source in case the main battery 10 is unable to supply power. The sub-battery 20 may be any secondary battery other than a lithium ion battery.

[0032] The multiple switches 31 to 38 include a battery switch 31, the above-mentioned system switch 32, a first load switch 33, a second load switch 34, a third load switch 35, a fourth load switch 36, a fifth load switch 37, and a sixth load switch 38.

[0033] The battery switch 31 is a switch that can connect and disconnect the sub-battery 20 and the second system 120. The inter-system switch 32 is provided on the inter-system line 130. The inter-system switch 32 is a switch that can connect and disconnect the first system 110 and the second system 120.

[0034] The first load switch 33 is a switch that can connect and disconnect the first system 110 and the first FOP load 101. The second load switch 34 is a switch that can connect and disconnect the second system 120 and the first FOP load 101.

[0035] The third load switch 35 is a switch that can connect and disconnect the first system 110 and the second FOP load 102. The fourth load switch 36 is a switch that can connect and disconnect the second system 120 and the second FOP load 102.

[0036] The fifth load switch 37 is a switch that can connect and disconnect the first system 110 and the non-FOP load 103. The sixth load switch 38 is a switch that can connect and disconnect the second system 120 and the non-FOP load 103.

[0037] The first voltage sensor 51 is provided in the first system 110. The first voltage sensor 51 detects the voltage of the first system 110 and outputs the detection result to the controller 3. The second voltage sensor 52 is provided in the second system 120. The second voltage sensor 52 detects the voltage of the second system 120 and outputs the detection result to the controller 3.

[0038] The first current sensor 61 detects the current supplied from the second system 120 to the first FOP load 101 and outputs the detection result to the controller 3. The second current sensor 62 detects the current supplied from the second system 120 to the second FOP load 102 and outputs the detection result to the controller 3. The third current sensor 63 detects the current supplied from the second system 120 to the non-FOP load 103 and outputs the detection result to the controller 3.

[0039] For example, when charging the sub-battery 20, the DCC 21 transforms the voltage input from the first system 110 via the inter-system line 130 and the second system 120 into a voltage suitable for charging the sub-battery 20 and supplies it to the sub-battery 20. When the DCC 21 is not operating, the input and output are directly connected, and power from the sub-battery 20 can be supplied to the second system 120.

[0040] The power supply circuit 30 is a circuit that adjusts the voltage supplied from at least one of the first system 110 and the second system 120 to a voltage suitable for the operation of the controller 3 and supplies the adjusted voltage to the controller 3. The controller 3 operates using power input via the power supply circuit 30.

[0041] The controller 3 includes a microcomputer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc., and various other circuits. The controller 3 may also be configured with hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0042] The controller 3 controls the operations of the battery switch 31, the inter-system switch 32, and the first to sixth load switches 33 to 38 by having the CPU execute a power supply control program stored in the ROM using the RAM as a work area. The power supply control program may be stored in a storage device from the outside via a communication line or the like.

[0043] Furthermore, the controller 3 is connected to the automatic driving control device 201, the first FOP load 101, the second FOP load 102, and the non-FOP load 103 via a CAN (Controller Area Network) bus 203 so as to be able to communicate information.

[0044] <1-2. Example of power supply control device operation> Next, an example of operation of the power supply control device 1 according to the first embodiment will be described with reference to Figures 2 to 4. Figures 2 to 4 are explanatory diagrams showing an example of operation of the power supply control device 1 according to the first embodiment.

[0045] 2, during normal operation when no power supply failure occurs, the controller 3 turns off the battery switch 31 and turns on the inter-system switch 32 and the first to sixth load switches 33 to 38. This allows power to be supplied from the main battery 10 to the first FOP load 101, the second FOP load 102, and the non-FOP load 103.

[0046] Thereafter, the controller 3 monitors whether a ground fault has occurred in the first system 110 or the second system 120. Specifically, when a ground fault occurs in the first system 110 or the second system 120, a large current flows toward the ground fault point, causing the voltage of the first system 110 (hereinafter referred to as "first system voltage V1") and the voltage of the second system 120 (hereinafter referred to as "second system voltage V2") to fall below the ground fault threshold.

[0047] Therefore, when the detection result (first system voltage V1 and second system voltage V2) input from the first voltage sensor 51 or the second voltage sensor 52 becomes below the ground fault threshold, the controller 3 provisionally determines that a ground fault has occurred in the first system 110 or the second system 120.

[0048] When the controller 3 provisionally determines that a ground fault has occurred, it pre-shuts off the inter-system switch 32 and turns on the battery switch 31, as shown in Fig. 3. This cuts off the connection between the first system 110 and the second system 120, and power is supplied to the first system 110 from the main battery 10, and to the second system 120 from the sub-battery 20. Thereafter, the controller 3 makes a final determination as to whether a ground fault has occurred in the first system 110 or the second system 120.

[0049] At this time, if a ground fault occurs in the second system 120, the second system voltage V2 remains below the ground fault threshold even when the inter-system switch 32 is turned off. On the other hand, the first system voltage V1 returns to a normal value higher than the ground fault threshold when the inter-system switch 32 is turned off.

[0050] Furthermore, if a ground fault occurs in the first system 110, the first system voltage V1 remains below the ground fault threshold even if the inter-system switch 32 is turned off. On the other hand, the second system voltage V2 returns to a normal value higher than the ground fault threshold when the inter-system switch 32 is turned off.

[0051] Therefore, the controller 3 officially determines that a ground fault has occurred in the second system 120 when the second system voltage V2 remains equal to or lower than the ground fault threshold for a predetermined time period after the inter-system switch 32 is turned off. Also, the controller 3 officially determines that a ground fault has occurred in the first system 110 when the first system voltage V1 remains equal to or lower than the ground fault threshold for a predetermined time period after the inter-system switch 32 is turned off.

[0052] If the first system voltage V1 and the second system voltage V2 remain higher than the ground fault threshold for a predetermined time after the inter-system switch 32 is turned off, the controller 3 determines that this is a transient voltage drop due to an overload or the like and that no ground fault has occurred. In this case, the controller 3 turns the inter-system switch 32 back on and turns the battery switch 31 off again, returning the state of the power supply control device 1 to the normal state shown in FIG. 2.

[0053] When the controller 3 determines that a ground fault has occurred in the first system 110, it shuts off the first load switch 33, the third load switch 35, and the fifth load switch 37 from the pre-shutdown state (see Figure 3), as shown in Figure 4.

[0054] As a result, power is supplied from the sub-battery 20 to the first FOP load 101, the second FOP load 102, and the non-FOP load 103 via the second system 120. As a result, the automatic driving control device 201 or the driver can operate the first FOP load 101 and the second FOP load 102 using power from the sub-battery 20 to cause the vehicle to run to safety.

[0055] If the controller 3 determines that a ground fault has occurred in the second system 120, it shuts off the battery switch 31, the second load switch 34, the fourth load switch 36, and the sixth load switch 38 from the pre-shutdown state (see Figure 3).

[0056] As a result, power is supplied from the main battery 10 to the first FOP load 101, the second FOP load 102, and the non-FOP load 103 via the first system 110. This allows the automatic driving control device 201 or the driver to operate the first FOP load 101 and the second FOP load 102 using power from the main battery 10 to cause the vehicle to run to safety.

[0057] When a ground fault occurs in the first system 110, the controller 3 performs fail-safe control using the sub-battery 20. However, since the power of the sub-battery 20 is limited, it is necessary to make the power of the sub-battery 20 last as long as possible during fail-safe control.

[0058] However, in order to perform efficient fail-safe control, the controller 3 needs to operate the minimum number of FOP loads (for example, the first FOP load 101) required to complete the evacuation travel. Therefore, the controller 3 performs power supply control that enables efficient fail-safe control while prolonging the life of the power of the sub-battery 20.

[0059] 1-3. Example of power supply control according to the first embodiment 5 is an explanatory diagram of an example of power supply control according to the first embodiment. During evacuation running under fail-safe control, for example, an operation of turning the steering wheel, an operation of maintaining the steering wheel in the turned state, an operation of returning the steering wheel, and an operation of maintaining the steering wheel in the returned position are repeated. During the period in which the steering state is maintained, the electric steering device is in an inoperative state.

[0060] Furthermore, during fail-safe driving, for example, when pumping the brakes, the electric brakes alternate between operating and inoperating periods. If power is supplied to the electric steering device and the electric brake device during these inoperating periods, a dark current is supplied from the sub-battery 20, resulting in unnecessary power consumption.

[0061] Therefore, when the controller 3 performs fail-safe control to supply power from the sub-battery 20 to the loads in the event of a failure of the main battery 10, the controller 3 supplies power to the loads that are in operation and stops supplying power to the loads that are not in operation.

[0062] 5, when fail-safe control (hereinafter sometimes referred to as "FOP") using power from the sub-battery 20 is initiated, the voltage of the sub-battery 20, i.e., the second system voltage V2, drops. Therefore, after the start of FOP, the controller 3 stops supplying power to the first FOP load 101 while the first FOP load 101 is not operating, and supplies power to the first FOP load 101 while the first FOP load 101 is operating.

[0063] Furthermore, after the start of FOP, the controller 3 stops supplying power to the second FOP load 102 while the second FOP load 102 is not operating, and supplies power to the second FOP load 102 while the second FOP load 102 is operating.

[0064] In this way, during FOP, the power supply control device 1 supplies power to the loads that are in operation and stops supplying power to the loads that are not in operation, thereby reducing unnecessary consumption of dark current and preventing the loads that are in operation from being stopped. As a result, the power supply control device 1 can prolong the life of the power of the sub-battery 20 during FOP, enabling efficient FOP.

[0065] 1-4. Processing Executed by the Controller According to the First Embodiment Next, the processing executed by the controller 3 according to the first embodiment will be described with reference to Fig. 6. Fig. 6 is a flowchart showing an example of the processing executed by the controller 3 according to the first embodiment. The controller 3 according to the first embodiment repeats the processing shown in Fig. 6 from when the ignition switch of the vehicle is turned on until it is turned off.

[0066] When the ignition switch is turned on, the controller 3 turns off (hereinafter may be referred to as "off") the battery switch 31. Then, the controller 3 turns on (hereinafter may be referred to as "on") the inter-system switch 32 and the first to sixth load switches 33 to 38, and then starts the processing shown in FIG.

[0067] 6, the controller 3 first determines whether or not a power failure has occurred (step S101). The power failure here is, for example, a ground fault in the first system 110 or the second system 120. If the controller 3 determines that a power failure has not occurred (step S101, No), the controller 3 ends the process.

[0068] Furthermore, when the controller 3 determines that a power supply failure has occurred (step S101, Yes), it turns off (pre-shutdown) the inter-system switch 32 and turns on the battery switch 31 (step S102). Next, the controller 3 makes a final determination of the system in which the ground fault has occurred (step S103). That is, the controller 3 makes a final determination of whether the system in which the ground fault has occurred is the first system 110 or the second system 120, or whether a ground fault has actually occurred.

[0069] When the controller 3 determines that the first system 110 has failed (Yes in step S104), the controller 3 turns off the load switches (the fifth load switch 37 and the sixth load switch 38) of the non-FOP load 103 (step S105).

[0070] Next, the controller 3 turns on the load switches of the operating FOP loads (step S106), turns off the load switches of the inactive FOP loads (step S107), and moves the process to step S108. The controller 3 determines that an FOP load that is communicating using the CAN bus 203 is an operating load, and determines that an FOP load that has not communicated using the CAN bus 203 for a predetermined time or longer is an inactive load.

[0071] Furthermore, if the first current sensor 61 detects a current equal to or greater than a certain amount, the controller 3 determines that the first FOP load 101 is in operation, and if the current is not equal to or greater than the certain amount, the controller 3 determines that the first FOP load 101 is not in operation. Similarly, if the second current sensor 62 detects a current equal to or greater than a certain amount, the controller 3 determines that the second FOP load 102 is in operation, and if the current is not equal to or greater than the certain amount, the controller 3 determines that the second FOP load 102 is not in operation.

[0072] Furthermore, in the case of a load that changes from inoperative to operative, the controller 3 detects that the load is being operated using the sensor of each operation device 202. For example, when the electric steering device is inoperative, if a change in the steering angle is detected from the steering angle sensor, the controller 3 determines that the electric steering device is being operated and turns on the load switch of the electric steering device. Furthermore, the controller 3 may determine a load that changes from inoperative to operative based on a control signal from the automatic driving control device 201.

[0073] In step S108, the controller 3 determines whether the FOP is complete. If the controller 3 determines that the FOP is not complete (step S108, No), the controller 3 proceeds to step S105. If the controller 3 determines that the FOP is complete (step S108, Yes), the controller 3 ends the process.

[0074] Furthermore, if the controller 3 determines that the first system 110 is not malfunctioning (step S104, No), it determines whether the second system 120 is malfunctioning (step S109). If the second system 120 is malfunctioning (step S109, Yes), the controller 3 turns off the battery switch 31 (step S110) and ends the process.

[0075] Furthermore, if the second system 120 is not faulty (step S109, No), that is, if it is determined in step S103 that no ground fault has occurred, the controller 3 turns on the system-to-system switch 32 and turns off the battery switch 31 (step S111) to restore the normal state, and ends the processing.

[0076] If the second system 120 fails (Yes in step S109), the controller 3 does not perform the processes of steps S105 to S108. This is because if the main battery 10 is a lead battery, it can supply power to the load for a longer period of time than the sub-battery 20, and power can also be supplied to the load by the DCC 11. However, if the second system 120 fails and the first system voltage V1 drops below the threshold voltage, the processes of steps S105 to S108 may be performed.

[0077] 2. Second Embodiment The power supply control device according to the second embodiment differs from the first embodiment only in the power supply control method and the processing executed by the controller 3. Therefore, here, the power supply control method and the processing executed by the controller 3 according to the second embodiment will be described, and overlapping descriptions will be omitted.

[0078] 2-1. Example of power supply control according to the second embodiment 7 is an explanatory diagram of an example of power supply control according to the second embodiment. When performing fail-safe control, if the voltage of the sub-battery 20 is higher than a threshold value, the controller 3 according to the second embodiment also supplies power to loads for fail-safe control that are not in operation and have a priority higher than a predetermined priority.

[0079] 7, when FOP is started, the controller 3 basically supplies power to the operating FOP loads and stops supplying power to the inactive FOP loads. However, if the second system voltage V2, which is the voltage of the sub-battery 20, is greater than the first threshold, the controller 3 also supplies power to the inactive FOP loads with high priority.

[0080] In this way, the power supply control device 1 supplies power not only to operating FOP loads but also to FOP loads with high priority, so that when an inactive FOP load becomes active, it can be controlled immediately, enabling efficient FOP.

[0081] Furthermore, when performing fail-safe control, the controller 3 may be configured to supply power to loads for fail-safe control that are not in operation and have a priority higher than a predetermined priority if the voltage of the sub-battery 20 is greater than the first threshold and less than the second threshold (>first threshold). With this configuration, the power supply control device 1 can also perform efficient FOP.

[0082] 2-2. Processing Executed by Controller According to Second Embodiment Next, a process executed by the controller 3 according to the second embodiment will be described with reference to Fig. 8. Fig. 8 is a flowchart showing an example of a process executed by the controller 3 according to the second embodiment. The controller 3 according to the second embodiment repeats the process shown in Fig. 8 from when the ignition switch of the vehicle is turned on until it is turned off.

[0083] When the ignition switch is turned on, the controller 3 turns off the battery switch 31, turns on the inter-system switch 32 and the first to sixth load switches 33 to 38, and then starts the processing shown in FIG.

[0084] 8, the controller 3 first determines whether or not a power failure has occurred (step S201). If the controller 3 determines that a power failure has not occurred (step S201, No), the controller 3 ends the process.

[0085] Furthermore, when the controller 3 determines that a power supply failure has occurred (step S201, Yes), it turns off (pre-shutdown) the inter-system switch 32 and turns on the battery switch 31 (step S202). Next, the controller 3 makes a final determination of the system in which the ground fault has occurred (step S203). That is, the controller 3 makes a final determination of whether the system in which the ground fault has occurred is the first system 110 or the second system 120, or whether a ground fault has actually occurred.

[0086] If the controller 3 determines that the first system 110 has failed (step S204, Yes), the controller 3 determines whether the second system voltage V2 is greater than the threshold value (step S205). If the controller 3 determines that the second system voltage V2 is greater than the threshold value (step S205, Yes), the controller 3 turns off the load switches (the fifth load switch 37 and the sixth load switch 38) of the non-FOP load 103 (step S206).

[0087] Next, the controller 3 turns on the load switches of the operating FOP loads and the high-priority FOP loads (step S207). Next, the controller 3 turns off the load switches of the inactive FOP loads (excluding the high-priority FOP loads) (step S208), and proceeds to step S209.

[0088] Furthermore, if the controller 3 determines that the second system voltage V2 is not greater than the threshold value (step S205, No), that is, if the controller 3 determines that the second system voltage V2 is equal to or less than the threshold value, the controller 3 turns off the load switch of the non-FOP load 103 (step S211).

[0089] Next, the controller 3 turns on the load switches of the FOP loads that are in operation (step S212), turns off the load switches of the FOP loads that are not in operation (step S213), and moves the process to step S209.

[0090] In step S209, the controller 3 determines whether the FOP is complete. If the controller 3 determines that the FOP is not complete (step S209, No), the controller 3 proceeds to step S205. If the controller 3 determines that the FOP is complete (step S209, Yes), the controller 3 ends the process.

[0091] Furthermore, if the controller 3 determines that the first system 110 is not malfunctioning (step S204, No), it determines whether the second system 120 is malfunctioning (step S210). If the second system 120 is malfunctioning (step S210, Yes), the controller 3 turns off the battery switch 31 (step S214) and ends the process.

[0092] Furthermore, if the controller 3 determines that there is no failure in the second system 120 (step S210, No), that is, that no ground fault has occurred, it turns on the system-to-system switch 32 and turns off the battery switch 31 (step S215) to restore the normal state, and ends the processing.

[0093] The controller 3 may perform a process of determining whether the second system voltage V2 is greater than the first threshold value and less than the second threshold value, instead of the process of step S205. In this case, when the controller 3 determines that the second system voltage V2 is greater than the first threshold value and less than the second threshold value, the controller 3 proceeds to step S206.

[0094] Furthermore, if the controller 3 determines that the second system voltage V2 is lower than the first threshold value or that the second system voltage V2 is equal to or higher than the second threshold value, the controller 3 proceeds to step S211.

[0095] 3. Third Embodiment The power supply control device according to the third embodiment differs from the first embodiment only in the power supply control method and the processing executed by the controller 3. Therefore, here, the power supply control method and the processing executed by the controller 3 according to the third embodiment will be described, and overlapping descriptions will be omitted.

[0096] 3-1. Example of power supply control according to the third embodiment Fig. 9 is an explanatory diagram of an example of power supply control according to the third embodiment. As shown in Fig. 9, after starting fail-safe control, the controller 3 according to the third embodiment supplies power to all loads for fail-safe control when the second system voltage V2, which is the voltage of the sub-battery 20, is higher than a threshold value. Then, when the voltage of the sub-battery 20 becomes equal to or lower than the threshold value, the controller 3 supplies power to the loads for fail-safe control that are in operation and stops supplying power to the loads for fail-safe control that are not in operation.

[0097] As a result, the power supply control device 1 can perform efficient fail-safe control using all FOP loads when the voltage of the sub-battery 20 is greater than the threshold. Then, when the voltage of the sub-battery 20 falls below the threshold, the controller 3 can complete fail-safe control by using the minimum necessary FOP loads while prolonging the life of the power of the sub-battery 20.

[0098] 3-2. Processing Executed by Controller According to Third Embodiment Next, a process executed by the controller 3 according to the third embodiment will be described with reference to Fig. 10. Fig. 10 is a flowchart showing an example of a process executed by the controller 3 according to the third embodiment. The controller 3 according to the third embodiment repeats the process shown in Fig. 10 from when the ignition switch of the vehicle is turned on until it is turned off.

[0099] When the ignition switch is turned on, the controller 3 turns off the battery switch 31, turns on the inter-system switch 32 and the first to sixth load switches 33 to 38, and then starts the processing shown in FIG.

[0100] 10, the controller 3 first determines whether or not a power failure has occurred (step S301). If the controller 3 determines that a power failure has not occurred (step S301, No), the controller 3 ends the process.

[0101] Furthermore, when the controller 3 determines that a power supply failure has occurred (step S301, Yes), it turns off (pre-shutdown) the inter-system switch 32 and turns on the battery switch 31 (step S302). Next, the controller 3 makes a final determination of the system in which the ground fault has occurred (step S303). That is, the controller 3 makes a final determination of whether the system in which the ground fault has occurred is the first system 110 or the second system 120, or whether a ground fault has actually occurred.

[0102] If the controller 3 determines that the first system 110 has failed (step S304, Yes), the controller 3 determines whether the second system voltage V2 is greater than the threshold value (step S305). If the controller 3 determines that the second system voltage V2 is greater than the threshold value (step S305, Yes), the controller 3 turns off the load switches (the fifth load switch 37 and the sixth load switch 38) of the non-FOP load 103 (step S306).

[0103] Next, the controller 3 turns on the load switches of all the FOP loads (step S307), and moves the process to step S308.

[0104] Furthermore, if the controller 3 determines that the second system voltage V2 is not greater than the threshold value (step S305, No), that is, if the controller 3 determines that the second system voltage V2 is equal to or less than the threshold value, it turns off the load switch of the non-FOP load 103 (step S310).

[0105] Next, the controller 3 turns on the load switches of the FOP loads that are in operation (step S311), turns off the load switches of the FOP loads that are not in operation (step S312), and moves the process to step S308.

[0106] In step S308, the controller 3 determines whether the FOP is complete. If the controller 3 determines that the FOP is not complete (step S308, No), the controller 3 proceeds to step S305. If the controller 3 determines that the FOP is complete (step S308, Yes), the controller 3 ends the process.

[0107] Furthermore, if the controller 3 determines that the first system 110 is not malfunctioning (step S304, No), it determines whether the second system 120 is malfunctioning (step S309). If the second system 120 is malfunctioning (step S309, Yes), the controller 3 turns off the battery switch 31 (step S313) and ends the process.

[0108] Furthermore, if the controller 3 determines that there is no failure in the second system 120 (step S309, No), that is, that no ground fault has occurred, it turns on the system-to-system switch 32 and turns off the battery switch 31 (step S314) to restore the normal state, and ends the processing.

[0109] ≪4.Load device≫ 4-1. Operation of the load device The first FOP load 101 and the second FOP load 102, which are examples of load devices according to the embodiment, may have power supply stopped or resumed by the power supply control device 1 during FOP.

[0110] The first FOP load 101 and the second FOP load 102 normally perform a shutdown process when power supply is stopped, and then restart when power supply is started, and perform an initial check before starting operation. The initial check includes, for example, checking whether switches inside the loads are stuck or whether there are any operational abnormalities.

[0111] If the first FOP load 101 and the second FOP load 102 perform an initial check every time power supply is resumed during FOP, they will not be able to start operating quickly. Therefore, when the first FOP load 101 and the second FOP load 102 according to the embodiment are restarted during FOP, they start operating without performing the initial check.

[0112] For example, if the load device loses power during fail-safe control, it stores power supply stop information indicating this in non-volatile memory, and if the power supply stop information is stored in memory when it is restarted, it restarts without performing an initial check. This allows the load device to start operating immediately after restarting when it is restarted during FOP.

[0113] The load device may also store the time when power supply was stopped during FOP in a non-volatile memory, and may be configured to restart the load device without performing an initial check if the time from the time stored in the memory to the next restart time is shorter than a threshold value.

[0114] This allows the load device to start operating immediately after restarting if it is restarted during FOP. Note that if the load device is normally shut down, that is, if the ignition switch is turned off, the next time the ignition switch is turned on to start up, an initial check will be performed.

[0115] 4-2. Processing performed by the load device Next, an example of processing executed by the load device according to the embodiment will be described with reference to Fig. 11 and Fig. 12. When the load device according to the embodiment is started up, it executes the processing shown in Fig. 11 or the processing shown in Fig. 12.

[0116] For example, as shown in FIG. 11, when the load device is started up, it determines whether the time obtained by subtracting the power-off time of the load in FOP stored in memory from the current time is longer than a threshold value for time determination (step S401).

[0117] If the time calculated in step S401 is not longer than the time determination threshold (step S401, No), that is, if the calculated time is extremely short, it is highly likely that the restart occurred during FOP. Therefore, the load device skips the initial check (step S402) and proceeds to step S403.

[0118] If the time calculated in step S401 is longer than the time determination threshold (step S401, Yes), it is highly likely that this is a normal start-up where the ignition switch is turned from off to on, and not a restart during FOP. Therefore, the load device performs an initial check (step S402) and then starts normal control (step S403).

[0119] Next, the load device determines whether the second system voltage V2 is lower than the voltage determination threshold (step S404). If the controller 3 determines that the second system voltage V2 is lower than the voltage determination threshold (step S404, Yes), the power supply is stopped thereafter, so the controller 3 stores the power-off time of the load during FOP in memory (step S405) and proceeds to step S403.

[0120] Furthermore, if the load device determines that the second system voltage V2 is not lower than the threshold value for voltage determination (step S404, No), the remaining charge of the sub-battery 20 is sufficient and power supply will not be stopped, so the load device transfers the processing to step S403 without storing the power-off time of the load during FOP in memory.

[0121] When the power supply to the load device is stopped by the above process, the load processing ends, and the time last stored in step S405 becomes the power-off time for the load during FOP.

[0122] The load device may receive failure information from the controller 3 and proceed to step S404 when the first system 110 fails. This prevents the load device from storing the power-off time due to a voltage drop unrelated to a power failure caused by natural discharge of the second system voltage V2 or the like.

[0123] 12, when the load device is started, it determines whether a power-off flag during FOP, which is an example of power supply stop information, is stored in memory (step S501). If the power-off flag is stored (step S501, Yes), the load device skips the initial check (step S502) and proceeds to step S503 because the load device is restarting during FOP.

[0124] Also, if the load device does not store the power-off flag (step S501, No), this is a normal startup where the ignition switch has been turned from off to on, so it performs an initial check (step S502) and starts normal control (step S503).

[0125] Next, the load device determines whether the second system voltage V2 is lower than a voltage determination threshold (step S504). This voltage determination threshold is set to a value slightly higher than the voltage at which the load device stops operating. If the load device determines that the second system voltage V2 is lower than the voltage determination threshold (step S504, Yes), power supply will be stopped thereafter. Therefore, the load device stores a power-off flag during FOP in memory (step S505) and proceeds to step S503.

[0126] Furthermore, if the load device determines that the second system voltage V2 is not lower than the threshold value for voltage determination (step S504, No), the remaining charge of the sub-battery 20 is sufficient and power supply will not be stopped, so the load device transfers processing to step S503 without storing the power-off flag of the load during FOP in memory.

[0127] 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]

[0128] 1 Power supply control device 3 Controller 10 Main battery 12 High-voltage battery 20 Sub-battery 30 Power circuit 31 Battery switch 32 Intersystem switch 33~38 1st to 6th load switches 51 First voltage sensor 52 Second voltage sensor 61 First current sensor 62 Second current sensor 63 Third current sensor 101 1st FOP load 102 2nd FOP load 103 Non-FOP load 110 1st system 120 2nd system 130 Intersystem Line 201 Automatic driving control device 202 Operating device

Claims

1. A controller that performs fail-safe control to supply power from the sub-battery to the load when the main battery fails, and that supplies power to the load in operation and stops power supply to the load inactive when the fail-safe control is performed. A power supply control device comprising:

2. The controller When the fail-safe control is performed, if the voltage of the sub-battery is greater than a threshold value, power is also supplied to loads for fail-safe control that are not in operation and have a priority higher than a predetermined priority. The power supply control device according to claim 1 .

3. The controller When the fail-safe control is performed, if the voltage of the sub-battery is greater than a first threshold value and less than a second threshold value, power is also supplied to loads for fail-safe control that are not in operation and have a priority higher than a predetermined priority. The power supply control device according to claim 1 .

4. The controller After starting the fail-safe control, if the voltage of the sub-battery is greater than a threshold value, power is supplied to all loads for the fail-safe control; When the voltage of the sub-battery becomes equal to or lower than the threshold, power is supplied to the load for fail-safe control that is in operation, and power supply to the load for fail-safe control that is not in operation is stopped. The power supply control device according to claim 1 .

5. When the main battery fails, a fail-safe control is performed to supply power from the sub-battery to the load device, and when the fail-safe control is performed, power supply is controlled by a power supply control device that supplies power to the load device in operation and stops power supply to the load device in operation; When power supply is stopped during the fail-safe control, power supply stop information indicating this is stored in a non-volatile memory, and if the power supply stop information is stored in the memory when the device is restarted, the device is restarted without performing an initial check. load device.

6. When the main battery fails, a fail-safe control is performed to supply power from the sub-battery to the load device, and when the fail-safe control is performed, power supply is controlled by a power supply control device that supplies power to the load device in operation and stops power supply to the load device in operation; The time when the power supply was stopped is stored in a non-volatile memory, and if the time from the time stored in the memory to the time of the next restart is shorter than a threshold, the initial check is omitted and the device is restarted. load device.

7. A procedure for performing fail-safe control to supply power to the load from the sub-battery in the event of a main battery failure; When the fail-safe control is performed, the controller of the power supply control device executes a procedure of supplying power to the loads in operation and stopping the supply of power to the loads that are not in operation. Power control program.

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