Power supply control device and power supply control method

Abstract

To provide a power supply control device and a power supply control method that are capable of preventing the occurrence of a surge and an instantaneous interruption when an IG is switched from OFF to ON.SOLUTION: A power supply control device according to an embodiment comprises: a first system; a second system; and a control unit. The first system supplies electric power of a main battery to a first load via a first switch. The second system supplies electric power of a sub-battery to a second load via a second switch. In a period during which an ignition switch of a vehicle is off, the control unit turns off the first switch and turns on the second switch to supplies power to the second load from the sub-battery. Upon detecting turning on of the ignition switch, the control unit temporally maintains the off state of the first switch, and turns off the second switch before turning on the first switch to supply power to the first load from the main battery.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] There is a system that includes a load that is supplied with power to operate while the vehicle's ignition switch (hereinafter referred to as "IG") is off, and a load that is supplied with power to operate while the IG is on (see, for example, Patent Document 1).

[0003] When power is supplied to loads that operate while the IG is off, if power is supplied to the loads from the main battery, power supply to each load begins when the IG is turned on, which can cause a power shortage in the main battery. For this reason, it is desirable to provide a sub-battery separate from the main battery and supply power to the loads from the sub-battery while the IG is off. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-83527 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the IG is turned on while power is being supplied from the sub-battery to the load, and the switches of various components are turned on or off as the IG is turned on, surges or short interruptions may occur, which may cause the switches to malfunction or the operation of the equipment to become unstable. 。 [Means for solving the problem]

[0006] A power supply control device according to one aspect of the embodiment includes a first system, a second system, and a control unit. The first system supplies power from a main battery to a first load via a first switch. The second system supplies power from a sub-battery to a second load via a second switch. The control unit turns off the first switch and turns on the second switch while an ignition switch of a vehicle is off to supply power from the sub-battery to the second load. When the control unit detects that the ignition switch is on, it temporarily keeps the first switch off, turns off the second switch, and then turns on the first switch to supply power from the main battery to the first load. 。 [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is an explanatory diagram illustrating an example of the configuration of a power supply control device according to an embodiment. [Figure 2] FIG. 2 is an explanatory diagram illustrating an example of the operation of the power supply control device according to the embodiment. [Figure 3] FIG. 3 is an explanatory diagram illustrating an example of the operation of the power supply control device according to the embodiment. [Figure 4] FIG. 4 is an explanatory diagram illustrating an example of the operation of the power supply control device according to the embodiment. [Figure 5] FIG. 5 is a flowchart illustrating an example of processing executed by the control unit of the power supply control device according to the embodiment. [Figure 6] FIG. 6 is a flowchart illustrating an example of processing executed by the control unit of the power supply control device according to the embodiment. [Figure 7] FIG. 7 is a flowchart illustrating an example of processing executed by the control unit of the power supply control device according to the embodiment. [Figure 8] FIG. 8 is a flowchart illustrating an example of processing executed by the control unit of the power supply control device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of a power supply control device and a power supply control method 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 power supply control device according to the embodiment is a device that controls the supply of power to electronic devices (hereinafter referred to as "loads") installed in a vehicle.

[0009] [1. Example of 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 an embodiment. As shown in Fig. 1, the power supply control device 1 is connected to a main battery 10, a first load 101, a second load 102, a vehicle 103, and a notification device 104.

[0010] The main battery 10 is, for example, a lead battery mounted on the vehicle 103. The main battery 10 may be a secondary battery other than a lead battery. The first load 101 is a device that operates while an ignition switch (hereinafter referred to as "IG") of the vehicle 103 is on, and is various electronic devices related to the running of the vehicle 103. The first load 101 includes, for example, an engine control device, a steering control device, a brake control device, an audio device, and a video display device.

[0011] The second load 102 is an electronic device that can operate both when the IG is off and when the IG is on, that is, at all times (including when the accessory switch is on). The second load 102 includes, for example, a drive recorder, a security device, an in-vehicle outlet for supplying power to external devices, etc. The notification device 104 includes a display device that displays various notification messages to the user and a sound output device that outputs the notification messages by sound.

[0012] The power supply control device 1 includes a sub-battery 20, a first system 110, a second system 120, first to seventh switches 11 to 17, and a control unit 3. The sub-battery 20 is, for example, a lithium ion battery. The sub-battery 20 may also be a secondary battery other than a lithium ion battery.

[0013] The sub-battery 20 supplies power to the second load 102 while the IG is off. The sub-battery 20 also functions as a backup power supply that supplies power to the first load 101 and the second load 102 in place of the main battery 10 when the power supply of the main battery 10 fails.

[0014] The first system 110 is a power supply line that supplies the power of the main battery 10 to the first load 101 and the second load 102. The second system 120 is a power supply line that supplies the power of the sub-battery 20 to the first load 101 and the second load 102.

[0015] The first switch 11 is a switch that can connect and disconnect the main battery 10 and the first system 110. The second switch 12 is a switch that can connect and disconnect the sub-battery 20 and the second system 120.

[0016] The third switch 13 is a switch that can connect and disconnect the first system 110 and the second system 120. The third switch 13 may be a DC / DC converter that adjusts the voltage difference between the first system 110 and the second system 120. When the third switch 13 is a DC / DC converter, the DC / DC converter connects the first system 110 and the second system 120 by operating and disconnects the first system 110 and the second system 120 by stopping its operation.

[0017] The fourth switch 14 is a switch that can connect and disconnect the first system 110 and the first load 101. The fifth switch 15 is a switch that can connect and disconnect the second system 120 and the first load 101.

[0018] The sixth switch 16 is a switch that can connect and disconnect the first system 110 and the second load 102. The seventh switch 17 is a switch that can connect and disconnect the second system 120 and the second load 102.

[0019] The control unit 3 includes a microcomputer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc., and various other circuits. The control unit 3 controls the first to seventh switches 11 to 17 by the CPU executing a program stored in the ROM using the RAM as a working area.

[0020] When a signal indicating that the IG is turned on or a signal indicating that the IG is turned off is input from the vehicle 103, the control unit 3 controls the first to seventh switches 11 to 17 in accordance with the input signal.

[0021] Furthermore, the control unit 3 monitors failures in the first system 110 and the second system 120 based on the detection results of a voltage sensor (not shown) that detects the voltage of the first system 110 and a voltage sensor that detects the voltage of the second system 120. If a failure occurs in one of the systems, the control unit 3 controls the first to seventh switches 11 to 17 so that power is supplied to the first load 101 and the second load 102 by the other system.

[0022] The control unit 3 may be partially or entirely configured with hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0023] [2. Example of power supply control device operation] Next, an example of the operation of the power supply control device 1 will be described with reference to Figures 2 to 4. Figures 2 to 4 are explanatory diagrams showing an example of the operation of the power supply control device 1 according to the embodiment.

[0024] 2, when the vehicle 103 is parked, that is, when the IG is off, the power supply control device 1 turns off the first switch 11 and the third to sixth switches 13 to 16 and turns on the second switch 12 and the seventh switch 17 to supply power from the sub-battery 20 to the second load 102. This allows the power supply control device 1 to operate, for example, a security device while the vehicle is parked.

[0025] Thereafter, when the IG is turned on, the power supply control device 1 turns off the second switch 12 and turns on the first switch 11 and the third to seventh switches 13 to 17, thereby supplying power from the main battery 10 to the first load 101 and the second load 102.

[0026] However, if the power supply control device 1 turns on the first switch 11 while the second switch 12 is on immediately after the IG is turned on, and then turns off the second switch 12 while current is flowing, a surge may occur, causing the second switch 12 to malfunction.

[0027] Therefore, when the control unit 3 detects that the IG is turned on, it temporarily keeps the first switch 11 off, and then turns on the first switch 11 to supply power from the main battery 10 to the first load 101.

[0028] At this time, for example, as shown in FIG. 3, when a signal IG-ON indicating that the IG has been turned on is input from the vehicle 103, the control unit 3 can turn off the seventh switch 17 while temporarily keeping the first switch 11 off, and then turn off the second switch 12.

[0029] As a result, when the control unit 3 turns off the second switch 12, no current flows through the second switch 12, so even if the second switch 12 is turned off, it is possible to prevent the second switch 12 from breaking down due to a surge.

[0030] Thereafter, as shown in FIG. 4, the control unit 3 turns on the first switch 11 and the third to seventh switches 13 to 17 while keeping the second switch 12 off, thereby supplying power from the main battery 10 to the first load 101 and the second load 102, thereby enabling the vehicle 103 to run.

[0031] Note that, although the control unit 3 turns off the seventh switch 17 here before turning off the second switch 12, this is just an example. In the power supply control device 1, if the power consumption of the second load 102 is less than a predetermined power, the second switch 12 is unlikely to break down due to a surge even if the seventh switch 17 remains on and the second switch 12 is turned off.

[0032] Therefore, when the control unit 3 detects that the IG is turned on, if there is a second load 102 whose power consumption is equal to or greater than a predetermined power, the control unit 3 can request the user to stop the operation of the second load 102. For example, when the control unit 3 detects that the IG is turned on, if the user is using an external device connected to an in-vehicle outlet, the control unit 3 causes the notification device 104 to output a notification message such as "Please stop the external device." Whether the power consumption of the external device is equal to or greater than a predetermined power can be determined by detecting the current flowing through the outlet included in the second load 102 using a current sensor (not shown) or the like.

[0033] As a result, if the user stops the operation of the second load 102 in response to a stop request, the power supply control device 1 can prevent the second switch 12 from failing due to a surge when the second switch 12 is later turned off in conjunction with the turning on of the IG, since no current is flowing through the second switch 12.

[0034] Furthermore, when the power consumption of second load 102 drops below a predetermined power after requesting operation stop, control unit 3 can turn off second switch 12 and then turn on first switch 11. As a result, in the power supply control device 1, the current flowing through second switch 12 has decreased when second switch 12 is turned off, so even if second switch 12 is turned off, failure of second switch 12 due to a surge can be prevented.

[0035] Furthermore, when a predetermined time has elapsed after the request to stop operation, the control unit 3 can turn off the second switch 12 and then turn on the first switch 11. As a result, if the user stops operation of the second load 102 in response to the stop request within the predetermined time, the power supply control device 1 can prevent a failure of the second switch 12 due to a surge when turning off the second switch 12 and suppress a delay in the start of post-startup processing.

[0036] Furthermore, when the control unit 3 detects that the IG is on, if there is a second load 102 whose power consumption is equal to or greater than a predetermined power, the control unit 3 notifies the user that the second load 102 will be stopped, and then stops the operation of the second load 102, turns off the second switch 12, and then turns on the first switch 11.

[0037] As a result, when the power supply control device 1 turns off the second switch 12, the second load 102 is no longer operating and no current is flowing through the second switch 12, so when the second switch 12 is turned off, the power supply control device 1 can prevent the second switch 12 from breaking down due to a surge.

[0038] Furthermore, when the control unit 3 detects that the IG is on, if there is any device in which a change due to a momentary interruption in the power supply is noticeable to the user, the control unit 3 notifies the user that a change will occur, and then turns off the second switch 12 and turns on the first switch 11.

[0039] For example, when the control unit 3 detects that the IG is turned on, if the user is using an external device, the control unit 3 causes the notification device 104 to output a notification message such as "Output will be temporarily interrupted."

[0040] This allows the power supply control device 1 to let the user know that the change in the operating state of the second load 102 caused by turning on the IG is not a malfunction.

[0041] [3. Processing performed by the control unit] Next, the processing executed by the control unit 3 of the power supply control device 1 will be described with reference to Fig. 5 to Fig. 8. Fig. 5 to Fig. 8 are flowcharts showing an example of the processing executed by the control unit 3 of the power supply control device 1 according to the embodiment.

[0042] When the control unit 3 detects that the IG is turned off, it executes the process shown in Fig. 5. Specifically, as shown in Fig. 5, the control unit 3 first turns off the first switch 11 and turns on the second switch 12 (step S101).

[0043] At this time, the control unit 3 turns off the third to sixth switches 13 to 16 while keeping the seventh switch 17 turned on. As a result, the control unit 3 can supply power from the sub-battery 20 to the second load 102 while the IG is turned off, thereby operating the second load 102.

[0044] Thereafter, the control unit 3 determines whether or not the IG is turned on (step S102). If the control unit 3 does not detect that the IG is turned on (step S102, No), the control unit 3 repeats the determination process of step S102 until the IG is detected to be turned on.

[0045] Then, when the control unit 3 detects that the IG is on (step S102, Yes), it keeps the first switch 11 off (step S103), and then executes startup processing (step S104). An example of the startup processing will be described later with reference to Figures 6 to 8. Next, the control unit 3 executes post-startup processing (step S105).

[0046] 4, the control unit 3 turns off the third switch 13, the fourth switch 14, and the sixth switch 16, and supplies power from the sub-battery 20 to the first load 101 and the second load 102. This allows the power supply control device 1 to continue the operation of the first load 101 and the second load 102 even if a power failure occurs in the first system 110.

[0047] 4, the control unit 3 turns off the third switch 13, the fifth switch 15, and the seventh switch 17, and supplies power from the main battery 10 to the first load 101 and the second load 102. This allows the power supply control device 1 to continue the operation of the first load 101 and the second load 102 even if a power failure occurs in the second system 120.

[0048] Thereafter, the control unit 3 determines whether or not the IG has been turned off (step S106). If the control unit 3 determines that the IG has not been turned off (step S106, No), the process proceeds to step S105. If the control unit 3 determines that the IG has been turned off (step S106, Yes), the control unit 3 ends the process and restarts the process from step S101.

[0049] In step S104, the control unit 3 executes, for example, the first startup process shown in Fig. 6. Specifically, as shown in Fig. 6, when the control unit 3 starts the first startup process, it first determines whether or not there is a second load 102 whose power consumption is equal to or greater than a predetermined power (step S201).

[0050] If the control unit 3 determines that there is no second load 102 whose power consumption is equal to or greater than the predetermined power (step S201, No), the control unit 3 proceeds to step S205. If the control unit 3 determines that there is a second load 102 whose power consumption is equal to or greater than the predetermined power (step S201, Yes), the control unit 3 requests the user to stop the operation of the second load 102 (step S202).

[0051] As a result, if the user stops the operation of the second load 102 in response to a stop request, the power supply control device 1 can prevent the second switch 12 from failing due to a surge when the second switch 12 is later turned off in conjunction with the turning on of the IG, since no current is flowing through the second switch 12.

[0052] Next, the control unit 3 determines whether the power consumption of the second load 102 has decreased to less than the predetermined power (step S203). If the control unit 3 determines that the power consumption of the second load 102 has decreased to less than the predetermined power (step S203, Yes), the control unit 3 turns off the second switch 12 from the state shown in Fig. 4 (step S205), and then turns on the first switch 11 (step S206).

[0053] As a result, in the power supply control device 1, the current flowing through the second switch 12 is reduced when the second switch 12 is turned off, so that even if the second switch 12 is turned off, failure of the second switch 12 due to a surge can be prevented.

[0054] Furthermore, in parallel with the control of step S206, the control unit 3 turns on the third to sixth switches 13 to 16 to bring them into the state shown in Fig. 4. Then, the control unit 3 moves the process to step S105 shown in Fig. 5.

[0055] Furthermore, if the control unit 3 determines that the power consumption of the second load 102 has not decreased to less than the predetermined power (step S203, No), it determines whether a predetermined time has elapsed since the control unit 3 requested the second load 102 to stop operating (step S204). If the control unit 3 determines that the predetermined time has not elapsed (step S204, No), it returns to step S203.

[0056] Furthermore, if the control unit 3 determines that the predetermined time has elapsed (Yes in step S204), it moves the process to step S205. As a result, if the user stops the operation of the second load 102 in response to a stop request within the predetermined time, the power supply control device 1 can prevent a failure of the second switch 12 due to a surge when turning off the second switch 12 and suppress a delay in the start of post-startup processing.

[0057] Furthermore, in step S104, the control unit 3 can also execute, for example, the second startup process shown in Fig. 7. Specifically, as shown in Fig. 7, when the control unit 3 starts the second startup process, it first determines whether or not there is a second load 102 whose power consumption is equal to or greater than a predetermined power (step S301). If the control unit 3 determines that there is no second load 102 whose power consumption is equal to or greater than the predetermined power (step S301, No), it proceeds to step S304.

[0058] Furthermore, when the control unit 3 determines that there is a second load 102 whose power consumption is equal to or greater than a predetermined power (step S301, Yes), it notifies the user that the second load 102 will be stopped (step S302), and then stops the second load 102 (step S303). After that, the control unit 3 turns off the second switch 12 (step S304), and then turns on the first switch 11 (step S305). Then, the control unit 3 proceeds to step S105 shown in FIG. 5.

[0059] As a result, when the power supply control device 1 turns off the second switch 12, the second load 102 is no longer operating and no current is flowing through the second switch 12, so when the second switch 12 is turned off, the power supply control device 1 can prevent the second switch 12 from breaking down due to a surge.

[0060] Furthermore, in step S104, the control unit 3 can also execute, for example, the third startup process shown in Fig. 8. Specifically, as shown in Fig. 8, when the control unit 3 starts the third startup process, it first determines whether there is any device whose change due to a momentary interruption in power supply will be noticeable to the user (step S401).

[0061] Examples of devices in which a change due to a momentary power outage is noticeable to a user include a drive recorder with a built-in display, electronic devices that operate on power supplied from an in-vehicle outlet, and electrical appliances.

[0062] If the control unit 3 determines that there is no device whose change due to a momentary interruption would be noticeable to the user (step S401, No), the control unit 3 proceeds to step S403. If the control unit 3 determines that there is a device whose change due to a momentary interruption would be noticeable to the user (step S401, Yes), the control unit 3 notifies the user that there is a change in the operating status of the device in use (step S402). Then, the control unit 3 turns off the second switch 12 (step S403), and then turns on the first switch 11 (step S404), and proceeds to step S105 shown in FIG. 5.

[0063] At this time, the power supply to the second load 102 is momentarily interrupted by the turning off of the second switch 12, and a change in the operating state may occur due to a decrease in the supplied power. In addition, when the first switch 11 is turned on and the operation of the first load 101 is started, the voltage of the main battery 10 temporarily drops, and a change in the operating state may occur due to a decrease in the supplied power.

[0064] Therefore, as described above, the power supply control device 1 notifies the user in advance that there will be a change in the operating state of the device in use, thereby enabling the user to recognize that the change in the operating state of the device due to the IG being turned on is not due to a malfunction of the device.

[0065] 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]

[0066] 1 Power supply control device 10 Main battery 20 Sub-battery 3. Control Unit 11 First Switch 12 Second Switch 13 Third Switch 14 4th Switch 15 5th Switch 16 6th Switch 17 7th Switch 101 1st load 102 2nd load 103 vehicles 104 Notification device 110 1st system 120 2nd system

Claims

1. a first system that supplies power from a main battery to a first load via a first switch; a second system that supplies power from the sub-battery to a second load via a second switch; During a period when an ignition switch of the vehicle is off, the first switch is turned off and the second switch is turned on to supply power from the sub-battery to the second load; a control unit that, when detecting that the ignition switch is turned on, temporarily keeps the first switch off, turns the second switch off, and then turns the first switch on to supply power from the main battery to the first load; A power supply control device comprising:

2. The control unit When the ignition switch is detected to be turned on, if there is a second load whose power consumption is equal to or greater than a predetermined power, a request is made to the user to stop the operation of the second load. The power supply control device according to claim 1 .

3. The control unit When the power consumption of the second load falls below a predetermined power after the request to stop the operation, the second switch is turned off and then the first switch is turned on. The power supply control device according to claim 2 .

4. The control unit When a predetermined time has elapsed after the request to stop the operation, the second switch is turned off and then the first switch is turned on. The power supply control device according to claim 2 .

5. The control unit When the on-state of the ignition switch is detected, if there is a second load whose power consumption is equal to or greater than a predetermined power, the device notifies a user that the second load will be stopped, stops the operation of the second load, turns off the second switch, and then turns on the first switch. The power supply control device according to claim 1 .

6. The control unit When the turning-on of the ignition switch is detected, if there is a device in which a change due to a momentary interruption in power supply is recognized by a user, the device notifies the user that the change will occur, turns off the second switch, and then turns on the first switch. The power supply control device according to claim 1 .

7. a first system that supplies power from a main battery to a first load via a first switch; a second system that supplies power from the sub-battery to a second load via a second switch; a control unit that controls the first switch and the second switch; The control unit of the power supply control device includes: During a period when an ignition switch of the vehicle is off, the first switch is turned off and the second switch is turned on to supply power from the sub-battery to the second load; A power supply control method in which, when the on state of the ignition switch is detected, the first switch is temporarily kept off, the second switch is turned off, and then the first switch is turned on to supply power from the main battery to the first load.

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