Power supply control device and power supply control method

Abstract

To provide a power supply controller and a power supply control method that can prevent an electric shock due to a leak of electricity.SOLUTION: A power supply controller comprises a control part. The control part turns off a power supply system if a vehicle stops on occurrence of a ground fault and the driver leaves the vehicle with the power supply on. The control part comprises a first system which supplies electric power from a main power supply to a first load and a second system which supplies electric power from a subordinate power supply to a second load. The control part turns off a switch for secondary-side battery which connects the subordinate power supply to the second system after the ground fault of the first system, and turns off a switch for primary-side battery which connects the main power supply to the first system after a ground fault of the second system.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] Conventionally, there has been a redundant power supply system that is equipped with a main power supply and a secondary power supply so that even if a power failure such as a ground fault occurs while a vehicle is driving in autonomous driving mode, the vehicle can be evacuated to a safe location and stopped.If a ground fault occurs in one of the power supply systems, the other power supply system supplies power to on-board equipment (load) for autonomous driving (see, for example, Patent Document 1).

[0003] The redundant power supply system includes a first system connected to a first load for automatic operation, a second system connected to a second load having the same function as the first load, and an inter-system switch capable of connecting and disconnecting the first system and the second system.

[0004] The redundant power supply system normally connects the inter-system switch to supply power from the main power supply to the first load and the second load. If a ground fault occurs in the first system, the redundant power supply system shuts off the inter-system switch to supply power from the secondary power supply to the second load, and if a ground fault occurs in the second system, the redundant power supply system shuts off the inter-system switch to supply power from the main power supply to the first load. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-182864 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, if the vehicle stops when a ground fault occurs and the driver gets off the vehicle with the power still on, there is a risk of receiving an electric shock due to a current leak.

[0007] One aspect of the embodiment has been made in view of the above, and aims to provide a power supply control device and a power supply control method that can prevent electric shock due to leakage current. [Means for solving the problem]

[0008] According to an embodiment, there is provided a power supply control device including a control unit that turns off a power supply system when a ground fault occurs, the vehicle stops, and the driver gets off the vehicle while the power supply is still on. Effect of the Invention

[0009] A power supply control device and a power supply control method according to an aspect of the embodiment can prevent electric shock due to leakage current. [Brief description 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 an embodiment. [Diagram 2] FIG. 2 is an explanatory diagram illustrating an example of the operation of the power supply control device according to the embodiment. [Diagram 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. [Diagram 5] FIG. 5 is an explanatory diagram illustrating an example of the operation of the power supply control device according to the embodiment. [Figure 6] FIG. 6 is an explanatory diagram illustrating an example of the operation of the power supply control device according to the embodiment. [Figure 7] FIG. 7 is an explanatory diagram illustrating an example of the operation of the power supply control device according to the embodiment. [Figure 8] FIG. 8 is a flowchart illustrating an example of a process executed by the control unit of the power supply control device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment 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 following embodiment. In the following, a power supply control device that is mounted on a vehicle with an automatic driving function and supplies power to a load will be described as an example, but the power supply control device according to the embodiment may be mounted on a vehicle that does not have an automatic driving function.

[0012] Further, 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 is run by an internal combustion engine.

[0013] In addition, the power supply control device according to the embodiment may be installed in any device that has a main power supply and a secondary power supply, and in the event of a power failure in either the main power supply or the secondary power supply, the other power supply system backs up the main power supply.

[0014] [1. Power supply control device configuration] Fig. 1 is an explanatory diagram showing a configuration example of a power supply control device according to an embodiment. As shown in Fig. 1, the power supply control device 1 according to the embodiment is connected to a main power supply 10, a first load 101, a general load 102, a second load 103, and an automatic operation control device 100. The power supply control device 1 includes a first system 110 that supplies power from the main power supply 10 to the first load 101 and the general load 102, and a second system 120 that supplies power from a secondary power supply 20 (described later) to the second load 103.

[0015] The first load 101 includes a load for autonomous driving. For example, 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 general load 102 includes, for example, a display, an air conditioner, an audio device, a video device, various lights, etc.

[0016] The second load 103 has the same function as the first load 101. The second load 103 includes devices that operate during automatic driving, such as a steering motor, an electric brake device, an in-vehicle camera, and a radar. The first load 101, the general load 102, and the second load 103 operate with power supplied from the power supply control device 1. The automatic driving control device 100 is a device that operates the first load 101 or the second load 103 to control the automatic driving of a vehicle.

[0017] The main 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"). Note that the battery of the main power source 10 may be any secondary battery other than the PbB 12.

[0018] The DC / DC 11 is connected to a generator and a high-voltage battery having a higher voltage than the PbB 12, and steps down the voltages of the generator and the high-voltage battery and outputs the stepped-down voltage to the first system 110. The generator is, for example, an alternator that converts the kinetic energy of a traveling vehicle into electricity to generate power. The high-voltage battery is, for example, a battery for driving the vehicle that is mounted on an electric vehicle or a hybrid vehicle.

[0019] When the main power supply 10 is installed in an engine vehicle, an alternator (generator) is provided instead of the DC / DC 11. The DC / DC 11 charges the PbB 12, supplies power to a first load 101 and a general load 102, supplies power to a second load 103, and charges the auxiliary power supply 20 described below.

[0020] The power supply control device 1 includes a secondary power supply 20, an inter-system switch 41, a secondary battery switch 42, a primary battery switch 43, a control unit 3, a first voltage sensor 51, and a second voltage sensor 52. The secondary power supply 20 is a backup power supply in the event that the main power supply 10 is unable to supply power. The secondary power supply 20 includes a lithium ion battery (hereinafter referred to as "LiB21"). Note that the battery of the secondary power supply 20 may be any secondary battery other than the LiB21.

[0021] The inter-system switch 41 is provided on the inter-system line 130 that connects the first system 110 and the second system 120, and is a switch that can connect and disconnect the first system 110 and the second system 120. The secondary-side battery switch 42 is a switch that connects the secondary power supply 20 to the second system 120. The primary-side battery switch 43 is a switch that connects the main power supply 10 to the first system 110.

[0022] The first voltage sensor 51 is provided in the first system 110, detects the voltage of the first system 110, and outputs the detection result to the control unit 3. The second voltage sensor 52 is provided in the second system 120, detects the voltage of the second system 120, and outputs the detection result to the control unit 3.

[0023] The control unit 3 includes a microcomputer having a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), etc., and various circuits. The control unit 3 may be configured with hardware such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

[0024] The control unit 3 controls the operation of the power supply control device 1 by having the CPU execute a program stored in the ROM using the RAM as a working area. When started up, the control unit 3 turns on the primary-side battery switch 43 and the system switch 41 and turns off the secondary-side battery switch 42.

[0025] The control unit 3 detects a ground fault in the first system 110 or the second system 120 based on the detection results input from the first voltage sensor 51 and the second voltage sensor 52. A specific example of a method for detecting a ground fault by the control unit 3 will be described later.

[0026] When the control unit 3 detects a ground fault in the first system 110 or the second system 120, it notifies the automatic driving control device 100 of that fact. When the control unit 3 detects a ground fault in the first system 110 or the second system 120, it may notify the automatic driving control device 100 of a state in which automatic driving is impossible. When the control unit 3 does not detect a ground fault in the first system 110 or the second system 120, it may notify the automatic driving control device 100 of a state in which automatic driving is possible.

[0027] When a power failure such as a ground fault occurs in the first system 110, the control unit 3 cuts off the system-to-system switch 41, turns on the secondary battery switch 42, and supplies power from the secondary power supply 20 to the second load 103. When a power failure such as a ground fault occurs in the second system 120, the control unit 3 cuts off the system-to-system switch 41, and supplies power from the main power supply 10 to the first load 101 and the general load 102 with the secondary battery switch 42 cut off.

[0028] As a result, even if a ground fault occurs in one of the systems during automatic driving, the power supply control device 1 can use the other system and cause the vehicle to retreat to a safe place and stop the vehicle using the automatic driving control device 100. Next, the operation of the power supply control device 1 will be described with reference to Figs. 2 to 7.

[0029] [2. Normal operation of the power supply control device] Under normal conditions when no ground faults have occurred in the first system 110 and the second system 120, the control unit 3 cuts off the secondary battery switch 42 and turns on the primary battery switch 43 and the inter-system switch 41, as shown in FIG. 2, to supply power from the main power source 10 to the first load 101, the general load 102, and the second load 103.

[0030] [3. Operation of power supply control device when a ground fault occurs] Next, the operation of the power supply control device 1 when a ground fault occurs will be described with reference to Figures 3 to 7. As shown in Figure 3, in the power supply control device 1, for example, when a ground fault 200 occurs in the first system 110 or when a ground fault 201 occurs in the second system 120, an overcurrent flows toward the ground fault point, and the voltages detected by the first voltage sensor 51 and the second voltage sensor 52 become equal to or lower than the ground fault threshold value.

[0031] Therefore, when the voltage detected by the second voltage sensor 52 becomes equal to or lower than the ground fault threshold, the control unit 3 provisionally determines that a ground fault 200, 201 has occurred in the first system 110 or the second system 120. Then, when the control unit 3 provisionally determines that a ground fault 200, 201 has occurred, it turns off the inter-system switch 41 and turns on the secondary-side battery switch 42. This cuts off the connection between the first system 110 and the second system 120, and power is supplied from the main power source 10 to the first system 110, and power is supplied from the secondary power source 20 to the second system 120.

[0032] When a ground fault 200, 201 occurs in the first system 110 or the second system 120, the voltage detected by the first voltage sensor 51 also becomes equal to or lower than the ground fault threshold. Therefore, the control unit 3 can tentatively determine that a ground fault has occurred in the first system 110 or the second system 120 when the voltage detected by at least one of the first voltage sensor 51 and the second voltage sensor 52 becomes equal to or lower than the ground fault threshold.

[0033] Thereafter, if the voltage detected by the first voltage sensor 51 is below the ground fault threshold for a predetermined time or more and the voltage detected by the second voltage sensor 52 returns to exceed the ground fault threshold within the predetermined time, the control unit 3 determines that a ground fault 200 has occurred in the first system 110.

[0034] 4, the control unit 3 turns off the primary battery switch 43, supplies power from the auxiliary power supply 20 to the second load 103, and notifies the automatic driving control device 100 of this fact. As a result, the automatic driving control device 100 can operate the second load 103 with the power supplied from the auxiliary power supply 20, and can evacuate the vehicle to a safe place and stop it.

[0035] Thereafter, after the vehicle has stopped, the driver may get off the vehicle with the power source (for example, IG (ignition switch)) still in the on state. At this time, as shown in FIG. 4, the auxiliary power source 20 and the second load 103 are maintained in a connected state. For this reason, if a leakage current has occurred in the second system 120 when the driver gets off the vehicle, the driver may receive an electric shock if he or she touches the vehicle after getting off the vehicle, for example.

[0036] Therefore, if the vehicle stops when the ground fault 200 occurs and the driver gets off the vehicle while the power source (for example, IG) is still on, the control unit 3 turns off the power supply system. Specifically, when the control unit 3 detects the ground fault 200 in the first system 110, it disconnects the first system 110 from the second system 120, and causes the second system 120, in which the ground fault 200 is not occurring, to perform evacuation travel control.

[0037] Thereafter, if the vehicle stops after the evacuation driving control due to the ground fault 200 in the first system 110 and the driver gets off the vehicle with the power source (e.g., IG) still on, the control unit 3 takes into consideration the possibility that a new ground fault has occurred in the second system 120, and turns off the secondary battery switch 42 as shown in Figure 5.

[0038] For example, after the vehicle has stopped following the evacuation driving control, the control unit 3 determines that the power is on based on the IG signal input from the IG, and when it determines that the driver has exited the vehicle based on the door sensor signal and the seat occupancy sensor signal, it turns off the secondary battery switch 42.

[0039] As a result, the power supply control device 1 can disconnect the connection between the secondary power supply 20 and the second load 103, so that even if a new ground fault occurs in the second system 120, the driver can be prevented from receiving an electric shock due to a current leakage when he or she gets off the vehicle and touches it.

[0040] In addition, after the control unit 3 has provisionally determined that a ground fault has occurred in the first system 110 or the second system 120, if the voltage detected by the second voltage sensor 52 is below the ground fault threshold even after a predetermined time has elapsed and the voltage detected by the first voltage sensor 51 returns to exceed the ground fault threshold within the predetermined time, the control unit 3 finally determines that a ground fault 201 has occurred in the second system 120.

[0041] 6, the control unit 3 turns off the secondary battery switch 42, supplies power from the main power supply 10 to the first load 101, and notifies the automatic driving control device 100 of this fact. As a result, the automatic driving control device 100 operates the first load 101 using the power supplied from the main power supply 10, and causes the vehicle to retreat to a safe place and stop.

[0042] Thereafter, after the vehicle stops, the driver may get off the vehicle with the power source (e.g., IG) still on. At this time, the main power source 10 and the first load 101 are maintained in a connected state as shown in Fig. 6. Therefore, if a leakage current occurs in the first system 110 when the driver gets off the vehicle, the driver may receive an electric shock if he or she touches the vehicle after getting off the vehicle.

[0043] Therefore, if the vehicle stops when the ground fault 201 occurs and the driver gets off the vehicle while the power source (for example, IG) is still on, the control unit 3 turns off the power supply system. Specifically, when the control unit 3 detects the ground fault 201 in the second system 120, it cuts off the first system 110 and the second system 120, and causes the first system 110 in which the ground fault 201 does not occur to perform evacuation travel control.

[0044] Thereafter, when the vehicle stops after the evacuation driving control due to the ground fault 201 in the second system 120 and the driver gets off the vehicle with the power source (e.g., IG) still on, the control unit 3 takes into consideration the possibility that a new ground fault has occurred in the first system 110, and turns off the primary side battery switch 43 as shown in FIG. 7.

[0045] For example, after the vehicle has stopped following the evacuation driving control, the control unit 3 determines that the power is on based on the IG signal input from the IG, and when it determines that the driver has exited the vehicle based on the door sensor signal and the seat occupancy sensor signal, it turns off the primary battery switch 43.

[0046] This allows the power supply control device 1 to disconnect the main power supply 10 from the first load 101, so that even if the driver touches the vehicle after getting off, the driver can be prevented from receiving an electric shock due to leakage current.

[0047] Furthermore, in the power supply control device 1, when the first load 101 or the general load 102 temporarily falls into an overload state, rather than the ground faults 200 and 201, the voltage detected by the first voltage sensor 51 may temporarily fall below the ground fault threshold. Furthermore, in the power supply control device 1, when the second load 103 temporarily falls into an overload state, the voltage detected by the second voltage sensor 52 may temporarily fall below the ground fault threshold.

[0048] In this case, in the power supply control device 1, power is continuously supplied from the main power supply 10 to the first load 101 and the general load 102, and power is continuously supplied from the secondary power supply 20 to the second load 103. Therefore, after the control unit 3 provisionally determines that a ground fault 200, 201 has occurred in the first system 110 or the second system 120, if the voltages detected by the first voltage sensor 51 and the second voltage sensor 52 both return to exceeding the ground fault threshold before a predetermined time has elapsed, the control unit 3 officially determines that the voltage drop is temporary and that there is no abnormality in the power supply. Thereafter, in order to return to the normal operation shown in FIG. 2, the control unit 3 turns off the secondary battery switch 42 and re-connects the inter-system switch 41.

[0049] [4. Processing performed by the control unit] Next, a process executed by the control unit 3 of the power supply control device 1 will be described with reference to Fig. 8. Fig. 8 is a flowchart showing an example of a process executed by the control unit of the power supply control device according to the embodiment. The flowchart shows an example of a process executed by the control unit of the power supply control device according to the embodiment.

[0050] The control unit 3 repeatedly executes the process shown in Fig. 8 during normal operation. Specifically, as shown in Fig. 8, the control unit 3 first determines whether or not a ground fault has occurred (step S101). If the control unit 3 determines that a ground fault has not occurred (step S101, No), it repeats the process of step S101 until a ground fault occurs.

[0051] If the control unit 3 determines that a ground fault has occurred (step S101, Yes), it turns off the system switch 41 and turns on the secondary battery switch 42 (step S102). Then, the control unit 3 determines whether or not a ground fault has occurred in the first system 110 (step S103).

[0052] When the control unit 3 determines that the first system 110 has a ground fault (step S103, Yes), it turns off the primary battery switch 43 (step S104). At this time, the control unit 3 notifies the automatic driving control device 100 that the first system 110 has a ground fault, and causes the vehicle to evacuate using the second system 120.

[0053] Thereafter, the control unit 3 judges whether or not the evacuation traveling has been completed (step S105). Specifically, if the vehicle stops after starting the evacuation traveling, the control unit 3 judges that the evacuation traveling has been completed. If the control unit 3 judges that the evacuation traveling has not been completed, i.e., that the vehicle has not stopped (step S105, No), the control unit 3 repeats the judgment process of step S105 until the evacuation traveling has been completed. Then, if the control unit 3 judges that the evacuation traveling has been completed (step S105, Yes), the control unit 3 judges whether or not the driver has got off the vehicle without performing an IG-OFF operation (step S106).

[0054] When the control unit 3 determines that the driver has not dismounted without turning off the IG-OFF (step S106, No), it repeats the determination process of step S106 until it determines that the driver has dismounted without turning off the IG-OFF. When the control unit 3 determines that the driver has dismounted without turning off the IG-OFF (step S106, Yes), it turns off the secondary battery switch 42 (step S107) and ends the process.

[0055] Furthermore, when the control unit 3 determines in step S103 that the first system 110 is not a ground fault (step S103, No), it determines whether or not the second system 120 is a ground fault (step S108). When the control unit 3 determines that the second system 120 is not a ground fault (step S108, No), it determines that a ground fault has not occurred, and turns on the inter-system switch 41 to return to the normal state, turns off the secondary-side battery switch 42 (step S113), and ends the process.

[0056] Furthermore, when the control unit 3 determines that the second system 120 has a ground fault (step S108, Yes), it turns off the secondary battery switch 42 (step S109). At this time, the control unit 3 notifies the automatic driving control device 100 that the second system 120 has a ground fault, and causes the vehicle to travel to an evacuation site using the first system 110.

[0057] Thereafter, the control unit 3 judges whether the evacuation traveling is completed or not, i.e., whether the vehicle has stopped or not (step S110). If the control unit 3 judges that the evacuation traveling is not completed or that the vehicle has not stopped (step S110, No), the control unit 3 repeats the judgment process of step S110 until the evacuation traveling is completed. Then, if the control unit 3 judges that the evacuation traveling is completed (step S110, Yes), the control unit 3 judges whether the driver has got off the vehicle without performing the IG-OFF operation (step S111).

[0058] When the control unit 3 determines that the driver has not dismounted without turning off the IG-OFF (step S111, No), it repeats the determination process of step S111 until it determines that the driver has dismounted without turning off the IG-OFF. When the control unit 3 determines that the driver has dismounted without turning off the IG-OFF (step S111, Yes), it turns off the primary battery switch 43 (step S112) and ends the process.

[0059] In the above-described embodiment, a case has been described in which the power supply control device 1 turns off the power supply system when the vehicle stops after performing evacuation driving control and the driver gets off the vehicle with the power supply still on, but this is just one example.

[0060] The power supply control device 1 can also turn off the power system after evacuation travel by manual driving is completed instead of automatic driving, or when the vehicle stops during normal driving and the driver gets off the vehicle with the power still on. This makes it possible for the power supply control device 1 to prevent the driver from getting an electric shock due to leakage current even if the driver who gets off the vehicle touches the vehicle after evacuation travel by manual driving is completed or when the vehicle stops during normal driving and the driver gets off the vehicle with the power still on.

[0061] Furthermore, up to this point, we have described the case where the power supply control device 1 is equipped with a primary side battery switch 43 and a secondary side battery switch 42, but the power supply control device 1 may be configured to be equipped with either the primary side battery switch 43 or the secondary side battery switch 42.

[0062] Further advantages and modifications may readily occur to those skilled in the art. Thus, 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 equivalents thereof. [Explanation of symbols]

[0063] 1 Power supply control device 10 Main power 11 DC / DC 12 PbB 20 Sub power supply 21 LiB 3. Control Unit 41 Intersystem switch 42 Secondary battery switch 43 Primary battery switch 51 First voltage sensor 52 Second voltage sensor 100 Automatic driving control device 101 1st load 102 General load 103 2nd load 110 1st system 120 2nd system

Claims

1. a first system that supplies power from a main power source to a first load; a second system that supplies power from the secondary power supply to a second load; a secondary battery switch for connecting the secondary power supply to the second system; a control unit that cuts off the first system and the second system when a ground fault is detected, turns on the switch for the secondary battery to perform evacuation travel control in the second system when a ground fault occurs in the first system, and turns off the switch for the secondary battery when the vehicle is stopped by the evacuation travel control and the driver gets off the vehicle with the power supply still on; A power supply control device comprising:

2. a first system that supplies power from a main power source to a first load; a second system that supplies power from the secondary power supply to a second load; a primary-side battery switch for connecting the main power supply to the first system; a control unit that cuts off the first system and the second system when a ground fault is detected, turns on the switch for the primary battery to perform evacuation travel control in the first system when a ground fault occurs in the second system, and turns off the switch for the primary battery when the vehicle is stopped by the evacuation travel control and the driver gets off the vehicle with the power supply still on; A power supply control device comprising:

3. A power supply control method in which a power supply device including a first system for supplying power from a main power supply to a first load, a second system for supplying power from a secondary power supply to a second load, and a secondary battery switch for connecting the secondary power supply to the second system is controlled by a control device, When a ground fault is detected, the first system and the second system are cut off, and when a ground fault occurs in the first system, the switch for the secondary battery is turned on to perform evacuation travel control in the second system, and when the vehicle is stopped by the evacuation travel control and the driver gets off the vehicle with the power supply still on, the switch for the secondary battery is turned off. Power control method.

4. A power supply control method in which a power supply device including a first system for supplying power from a main power supply to a first load, a second system for supplying power from a secondary power supply to a second load, and a primary-side battery switch for connecting the main power supply to the first system is controlled by a control device, When a ground fault is detected, the first system and the second system are cut off, and when a ground fault occurs in the second system, the switch for the primary battery is turned on to perform evacuation travel control in the first system, and when the vehicle is stopped by the evacuation travel control and the driver gets off the vehicle with the power supply still on, the switch for the primary battery is turned off. Power control method.

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