Power supply and autonomous driving systems

Abstract

To provide a power supply device and an automatic operation system capable of performing charging control that takes into account processing for specifying an abnormal spot.SOLUTION: A controller for a power supply device performs normal control of turning on an intersystem switch and turning off a power supply switch in a case where first and second systems are normal, and performs abnormality detection control of detecting abnormalities of the first or second system by turning off the intersystem switch and turning on the power supply switch in a case where power supply failures of the first or second system are detected. In a case where no abnormalities of the first and second systems are detected by the abnormality detection control, the controller switches to the normal control and stores in a storage a reduction amount in voltage of a second power supply resulting from the abnormality detection control. When charging the second power supply, the controller charges the second power supply until the second power supply has a voltage equal to or more than a value obtained by adding the reduction amount to a drive voltage required for driving a second load.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a power supply device and an automatic driving system.

Background Art

[0002] Conventionally, even when a power failure occurs during the running of a vehicle, a redundant power supply system is provided with a first power supply and a second power supply so that the vehicle can be driven to a safe place and stopped. When an abnormality such as a ground fault occurs in one power supply system, the other power supply system supplies power to in-vehicle devices (loads).

[0003] The redundant power supply system includes a first system that supplies power from the first power supply to the first load, a second system that supplies power from the second power supply to the second load having the same function as the first load, and an inter-system switch that can disconnect the connection between the first system and the second system (see, for example, Patent Document 1).

[0004] Also, in the redundant power supply system, normally, the inter-system switch is connected to supply power from the first power supply to the first load and the second load. When a power failure such as a ground fault occurs in the first system, the inter-system switch is disconnected to supply power from the second power supply to the second load and perform backup control.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In this type of redundant power supply system, when a power failure in the first system or the second system is detected, before performing backup control, the inter-system switch is disconnected to supply power from each power supply to each load, and a process of identifying an abnormal location may be performed.

[0007] Therefore, when the second power supply is charged based on the amount of power required for backup control, depending on the power used for the process of identifying the abnormal location, the power of the second power supply during backup control may be depleted.

[0008] The present invention has been made in view of the above, and an object thereof is to provide a power supply device and an automatic driving system capable of performing charging control taking into account the process of identifying an abnormal location.

Means for Solving the Problems

[0009] In order to solve the above-described problems and achieve the object, a power supply device according to the present invention includes a first system, a second system, an inter-system switch, a power switch, and a control unit. In the first system, the power of the first power supply is supplied to the first load. In the second system, the power of the second power supply is supplied to the second load. The inter-system switch connects or disconnects the first system and the second system. The power switch connects or disconnects the second power supply and the second system. When the first system and the second system are normal, the control unit performs normal control of connecting the inter-system switch and disconnecting the power switch, and when a power failure of the first system or the second system is detected, the control unit performs abnormal detection control of detecting an abnormality in the first system or the second system by disconnecting the inter-system switch and connecting the power switch. When no abnormality in the first system and the second system is detected by the abnormal detection control, the control unit switches to the normal control and stores the amount of voltage drop of the second power supply associated with the abnormal detection control in a storage unit, and when charging the second power supply, charges the second power supply until the voltage becomes equal to or higher than the voltage obtained by adding the amount of drop to the driving voltage required to drive the second load.

Effects of the Invention

[0010] According to the present invention, it is possible to perform charging control taking into account the process of identifying an abnormal location.

Brief Description of the Drawings

[0011]

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DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the power supply device disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited by the embodiments shown below. The power supply device according to the embodiment is mounted on a vehicle having an automatic driving function and supplies power to loads related to automatic driving control.

[0013] FIG. 1 is a diagram showing a configuration example of an automatic driving system S including a power supply device 1 according to the embodiment. As shown in FIG. 1, the automatic driving system S includes a power supply device 1, a first power supply 10, a vehicle control device 100, a first load 101, and a second load 102.

[0014] The first load 101 includes loads related to autonomous driving. For example, the first load 101 includes a steering motor, an electric brake device, an in-vehicle camera, and a radar that operate during autonomous driving. Note that the first load 101 may include general loads that have nothing to do with autonomous driving, such as a display, an air conditioner, an audio system, a video system, and various lights.

[0015] The second load 102 includes loads related to autonomous driving. For example, the first load 101 includes a steering motor, an electric brake device, an in-vehicle camera, and a radar that operate during autonomous driving.

[0016] The vehicle control device 100 is a control device that operates the first load 101 and the second load 102 to perform automatic driving control of the vehicle.

[0017] The first power supply 10 includes a DC / DC converter 11 (hereinafter referred to as DC / DC 11) and a lead battery 12 (hereinafter referred to as PbB 12). Note that the battery of the first power supply 10 may be any secondary battery other than PbB 12.

[0018] DC / DC 11 is connected, on the upstream side, to a generator that converts the regenerative energy of the vehicle into electric power for power generation, and transforms and outputs the input voltage input from the generator. The generator may be an alternator that converts the rotational force of the engine into electric power for power generation when the vehicle is equipped with an engine. DC / DC 11 performs charging of PbB 12, power supply to the first load 101, power supply to the second load 102, and charging of the second power supply 20 described later.

[0019] The power supply device 1 is a device that controls the power supply to the first load 101 and the second load 102. As shown in FIG. 1, the power supply device 1 includes a second power supply 20, an inter-system switch 4, a control unit 31, a storage unit 32, and voltage sensors 51 and 52.

[0020] The second power supply 20 is a backup power supply when the power supply by the first power supply 10 becomes unavailable. The second power supply 20 includes a lithium-ion battery 21 (hereinafter referred to as "LiB 21") and a power switch 22. The power switch 22 is connected so as to be able to connect / disconnect the LiB 21 and the second load 102. Note that the battery of the second power supply 20 may be any secondary battery other than the LiB 21.

[0021] Also, the power supply device 1 includes a first system 110 that supplies power from the first power supply 10 to the first load 101, and a second system 120 that supplies power from the second power supply 20 to the second load 102.

[0022] The inter-system switch 4 is connected so as to be able to connect / disconnect the first system 110 and the second system 120.

[0023] The voltage sensor 51 is connected between the first power supply 10 and the first load 101 and detects the voltage value of the first system 110. The voltage sensor 52 is connected between the second power supply 20 and the second load 102 and detects the voltage value of the second system 120.

[0024] The control unit 31 includes a microcomputer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and various circuits. Note that the control unit 31 may be configured by hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The storage unit 32 is a storage unit configured by a storage device such as a non-volatile memory, a data flash, or a hard disk drive. Information on the amount of decrease and various programs described later are stored in such a storage unit 32.

[0025] The control unit 31 controls the operation of the power supply device 1 by the CPU executing a program stored in the ROM using the RAM as a work area. Based on the detection results (voltage values) input from the voltage sensors 51 and 52, the control unit 31 supplies power from the first power supply 10 or the second power supply 20 to the first load 101 and the second load 102 by performing on / off control of the inter-system switch 4 and the power switch 22.

[0026] In FIG. 1, an example of normal control (normal control) when no abnormality such as a ground fault has occurred in the first system 110 and the second system 120 is shown. Specifically, during normal control, the control unit 3 turns on the inter-system switch 4 and turns off the power switch 22.

[0027] Thereby, power is supplied from the first power supply 10 to the first load 101 via the first system 110, and power is supplied from the first power supply 10 to the second load 102 via the first system 110, the inter-system switch 4, and the second system 120. Note that this normal control is performed regardless of whether the vehicle is in the automatic driving or manual driving mode.

[0028] Here, assume that during normal control in automatic driving, the voltage value of the voltage sensor 51 drops below a predetermined threshold for ground fault (abnormality) determination. That is, assume that a power failure in the first system 110 or the second system 120 is detected based on the voltage value of the voltage sensor 51. In such a case, since there may be an abnormality such as a ground fault in the first system 110 or the second system 120, the power supply device 1 switches from normal control to abnormality detection control for identifying the abnormal location.

[0029] Here, the abnormality detection control will be described with reference to FIG. 2. FIG. 2 is a diagram showing an operation example of the abnormality detection control. When the voltage value of the voltage sensor 51 drops below a predetermined threshold during normal control, the control unit 31 of the power supply device 1 turns off the inter-system switch 4 and turns on the power switch 22.

[0030] As a result, when the connection between the first system 110 and the second system 120 is disconnected, the power supply to the first load 101 is performed by the first power supply 10, and the power supply to the second load 102 is performed by the second power supply 20.

[0031] Then, based on the voltage values of the voltage sensors 51 and 52, the control unit 31 detects whether an abnormality has occurred in each of the first system 110 and the second system 120. Specifically, the control unit 31 detects whether an abnormality has occurred in the first system 110 based on the voltage value of the voltage sensor 51, and detects whether an abnormality has occurred in the second system 120 based on the voltage value of the voltage sensor 52. That is, the control unit 31 specifies whether the location where the abnormality has occurred is the first system 110, the second system 120, or both (by means of abnormality detection control).

[0032] For example, as shown in FIG. 2, when no abnormality has occurred in both the first system 110 and the second system 120, the control unit 31 turns on the inter-system switch 4 and turns off the power switch 22. That is, it returns from the abnormality detection control to the normal control.

[0033] In this way, during normal control, when the voltage value of the voltage sensor 51 decreases, as shown in FIG. 2, the control unit 31 temporarily turns on the power switch 22 to check for abnormalities in the second system 120 using the power of the second power supply 20. In the present disclosure, the amount of power reduction of the second power supply 20 due to the abnormality check of the second system 120 is memorized, and the memorized amount-of-reduction information is used for various controls such as charging control. Details regarding this point will be described later.

[0034] In addition, in the abnormality detection control, when an abnormality has occurred only in the first system 110, the control will switch from the abnormality detection control to the evacuation running control shown in FIG. 3.

[0035] FIG. 3 is a diagram showing an operation example of the evacuation driving control. The evacuation driving control is a driving control for evacuating and stopping a vehicle during autonomous driving to a safe place such as a road shoulder when an abnormality occurs in the first system 110 or the second system 120, because the redundancy of the power supply in autonomous driving is no longer ensured.

[0036] As shown in FIG. 3, when an abnormality occurs in the first system 110, the control unit 31 continuously turns off the inter-system switch 4 and continuously turns on the power switch 22. Then, the control unit 31 stops the power supply from the first power supply 10 to the first load 101 and continues to supply power from the second power supply 20 to the second load 102. That is, when an abnormality occurs in the first system 110, the control unit 31 performs the evacuation driving control only with the power of the second power supply 20.

[0037] Therefore, the remaining power storage amount of the second power supply 20 needs to secure the amount of power required for the evacuation driving control. However, as shown in FIG. 2, since the second power supply 20 also consumes power for the abnormality detection control, depending on the amount of power reduction of the second power supply 20 due to the abnormality detection control, there is a possibility of falling below the amount of power required for the evacuation driving control.

[0038] Therefore, as shown in FIG. 2, the power supply device 1 according to the embodiment stores the amount of power reduction of the second power supply 20 due to the abnormality detection control in the storage unit 32. Specifically, the control unit 31 stores the amount of power reduction of the second power supply 20 when no abnormality has occurred in both the first system 110 and the second system 120 in the abnormality detection control. For example, the control unit 31 stores the amount of voltage reduction of the voltage sensor 52 from the start of the abnormality detection control until the return to the normal control. Specifically, the control unit 31 stores the amount of voltage reduction of the voltage sensor 52 from when the power switch 22 is turned on with the start of the abnormality detection control until the power switch 22 is turned off with the return to the normal control.

[0039] In the example shown in FIG. 2, when the remaining charge amount (SOC: State Of Charge) of the second power source 20 decreases from 80% to 77%, the difference value between the voltage value corresponding to 80% in the SOC and the voltage value corresponding to 77% is stored as the decrease amount. Further, the information on the decrease amount may be not limited to the difference value of the voltage value, but may also be the difference value of the SOC.

[0040] Note that the storage unit 32 in which the information on the decrease amount is stored may be a storage unit 32 built in the power supply device 1, or may be an external storage unit connected to the power supply device 1. And the control unit 31 performs charge control of the second power source 20 shown in FIG. 4 using the stored information on the decrease amount.

[0041] FIG. 4 is a diagram showing an operation example of the charge control. The charge control is control for charging the LiB 21 of the second power source 20 via the DC / DC 11 of the first power source 10 from the above-described generator. As shown in FIG. 4, when performing the charge control, the control unit 31 turns on the inter-system switch 4 and turns on the power switch 22. Thereby, power is supplied from the first power source 10 to the second power source 20, and the LiB 21 is charged.

[0042] Further, the control unit 31 charges the LiB 21 until the remaining charge amount determined based on the above-described information on the decrease amount and the required power, which is the driving power required for driving the second load 102 during the evacuation traveling control, is reached. In the example shown in FIG. 4, it is assumed that the required power of the second load 102 is 80% and the decrease amount during the abnormality detection control is 3%.

[0043] In such a case, the control unit 31 controls to charge at least until the required power of the second load 102 decreases to 83% obtained by adding 3% of the decrease amount to 80%. Specifically, the control unit 31 performs the charge control until the voltage value of the voltage sensor 52 becomes equal to or higher than the voltage value corresponding to 83% in the SOC.

[0044] In this way, by charging while taking into account the amount of power reduction during the abnormality detection control, even when switching from the abnormality detection control to the evacuation driving control, it is possible to surely perform the evacuation driving control without causing a power shortage in the LiB21 during the evacuation driving. That is, according to the power supply device 1 according to the embodiment, it is possible to perform the charging control of the second power supply 20 in consideration of the process of specifying the abnormal portion (abnormality detection control).

[0045] Note that the control unit 31 has been described as storing the information on the reduction amount measured during the abnormality detection control in the storage unit 32 and using it for the charging control. However, for example, the reduction amount acquired in advance by experiments or the like may be stored in the storage unit 32 as an initial value and the initial value may be updated. Specifically, the control unit 31 updates the initial value based on the actual value of the reduction amount measured when performing the abnormality detection control. For example, the control unit 31 stores the simple average value or weighted average value of the initial value and the actual value as the final reduction amount. Alternatively, the control unit 31 stores the initial value by replacing it with the actual value. The control unit 31 performs such update processing each time the actual value is measured.

[0046] Thereby, since the change in the reduction amount due to aging of the storage unit 32 and the change in the power consumption of the abnormality detection control can be taken into account in the reduction amount, the accuracy of the stored reduction amount can be improved. Furthermore, by storing the initial value of the reduction amount, it is possible to perform the charging control in consideration of the reduction amount (initial value) even before the actual value by the abnormality detection control is measured.

[0047] Next, with reference to FIG. 5, an example of notifying the vehicle control device 100 of the availability of autonomous driving based on the above-described reduction amount information will be described.

[0048] FIG. 5 is a diagram showing an operation example of notifying the availability of autonomous driving. In FIG. 5, it is assumed that the remaining battery level of the current LiB21 is 82% and the total value of the required power and the reduction amount is 83%.

[0049] That is, in the example shown in FIG. 5, since the current remaining charge of LiB21 is less than the sum of the required power and the decrease amount, when switching from the abnormality detection control to the evacuation driving control using the second power source 20, there is a possibility that the evacuation driving control cannot be completed due to power shortage.

[0050] Therefore, when the current remaining charge of LiB21 is less than the sum of the required power and the decrease amount, the control unit 31 notifies the vehicle control device 100 that automatic driving control cannot be performed.

[0051] In addition, when the current remaining charge of LiB21 reaches 83% or more by subsequent charging control, the control unit 31 notifies the vehicle control device 100 that automatic driving control can be performed. That is, when the second power source 20 is equal to or higher than the voltage obtained by adding the decrease amount to the driving voltage (voltage corresponding to the required power), the control unit 31 issues a permission notification to permit automatic driving to the vehicle control device 100. Thereby, the vehicle control device 100 can avoid with high precision a situation where the evacuation driving control during automatic driving cannot be completed due to power shortage by performing automatic driving only when receiving the permission notification from the power supply device 1.

[0052] Further, in FIG. 5, an example of notifying the vehicle control device 100 of the availability of automatic driving, that is, an example of determining and notifying the availability of automatic driving on the power supply device 1 side is shown. However, the vehicle control device 100 may be made to determine the availability of automatic driving. This point will be described with reference to FIG. 6.

[0053] FIG. 6 is a diagram showing an operation example in which the vehicle control device 100 determines the availability of automatic driving. As shown in FIG. 6, the control unit 31 notifies the vehicle control device 100 of the information on the decrease amount. In addition, the vehicle control device 100 grasps in advance the required power during the evacuation driving control. Then, the vehicle control device 100 detects (or acquires from the control unit 31) the remaining charge amount of LiB21, and determines the availability of automatic driving based on the detected remaining charge amount, required power, and information on the decrease amount.

[0054] As a result, it becomes unnecessary for the control unit 31 to determine whether or not autonomous driving is possible, so the processing load on the control unit 31 can be reduced.

[0055] Next, with reference to FIG. 7, the procedure of the process executed in the power supply device 1 according to the embodiment will be described. FIG. 7 is a flowchart showing the procedure of the process executed by the power supply device 1 according to the embodiment.

[0056] As shown in FIG. 7, first, it is assumed that the control unit 31 is performing normal control in autonomous driving (step S101).

[0057] Subsequently, the control unit 31 determines whether or not a voltage abnormality (voltage drop) of the first power supply 10 or the second power supply 20, that is, a power supply failure of the first system 110 or the second system 120 has occurred based on the voltage values of the voltage sensors 51 and 52 (step S102). When no voltage abnormality (voltage drop) of the first power supply 10 and the second power supply 20 has occurred (step S102: No), the process proceeds to step S101.

[0058] Further, when a voltage abnormality (voltage drop) of the first power supply 10 or the second power supply 20 has occurred (step S102: Yes), the control unit 31 switches from normal control to abnormality detection control by turning off the inter-system switch 4 and turning on the power switch 22 (step S103).

[0059] Subsequently, the control unit 31 determines in which system of the first system 110 and the second system 120 an abnormality has occurred by the abnormality detection control (step S104).

[0060] When an abnormality has occurred in one of the first system 110 and the second system 120 (step S104: Yes), the control unit 31 switches from the abnormality detection control to the evacuation driving control using the normal other system (step S105), and ends the process.

[0061] On the other hand, when there is no abnormality in both the first system 110 and the second system 120 (step S104: No), the control unit 31 turns on the inter-system switch 4 and turns off the power switch 22 to return to normal control (step S106), stores the voltage drop amount of the second power supply 20 in the storage unit 32 by the abnormality detection control (step S107), and returns to step S101.

[0062] Next, with reference to FIG. 8, the procedure of the charging control process executed in the power supply device 1 according to the embodiment will be described. FIG. 8 is a flowchart showing the processing procedure of the charging control process executed by the power supply device 1 according to the embodiment.

[0063] As shown in FIG. 8, it is assumed that the control unit 31 is performing charging control (step S201). Subsequently, the control unit 31 determines whether the voltage value of the voltage sensor 52 has reached the voltage considering the above-described voltage drop amount (step S202). Specifically, the control unit 31 determines whether the voltage has reached the voltage corresponding to the sum value obtained by adding the voltage drop amount to the required power of the second load 102.

[0064] When the control unit 31 reaches the voltage considering the voltage drop amount (step S202: Yes), it issues a permission notification for automatic driving to the vehicle control device 100 (step S203) and ends the process.

[0065] On the other hand, when the control unit 31 has not reached the voltage considering the voltage drop amount (step S202: No), it issues a non-permission notification for automatic driving to the vehicle control device 100 (step S204) and executes step S202 again.

[0066] As described above, the power supply device 1 according to the embodiment includes a first system 110, a second system 120, an inter-system switch 4, a power supply switch 22, and a control unit 31. In the first system 110, the power of the first power supply 10 is supplied to the first load 101. In the second system 120, the power of the second power supply 20 is supplied to the second load 102. The inter-system switch 4 connects or disconnects the first system 110 and the second system 120. The power supply switch 22 connects or disconnects the second power supply 20 and the second system 120. When the first system 110 and the second system 120 are normal, the control unit 31 performs normal control to connect the inter-system switch 4 and disconnect the power supply switch 22. When a power failure in the first system 110 or the second system 120 is detected, the control unit 31 performs abnormal detection control to detect an abnormality in the first system 110 or the second system 120 by disconnecting the inter-system switch 4 and connecting the power supply switch 22. When no abnormality in the first system 110 and the second system 120 is detected by the abnormal detection control, the control unit 31 switches to the normal control, stores the amount of voltage drop of the second power supply 20 associated with the abnormal detection control in the storage unit 32, and when charging the second power supply 20, charges the second power supply 20 until the voltage becomes equal to or higher than the voltage obtained by adding the amount of voltage drop to the driving voltage required to drive the second load 102. Thereby, charging control considering the process of specifying the abnormal portion can be performed.

[0067] Further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspects of the present invention are not limited to the specific details and representative embodiments represented and described as above. Accordingly, various changes can be made without departing from the spirit or scope of the general inventive concept defined by the appended claims and their equivalents.

Description of Reference Numerals

[0068] 1 Power supply device 3 Control unit 4 Inter-system switch 10 First power supply 11 DC / DC converter 12 Lead battery 20 Second power supply 21 Lithium-ion battery 22 Power switch 31 Control unit 32 Memory unit 51, 52 Voltage sensors 100 Vehicle control device 101 First load 102 Second load 110 First system 120 Second system S Autopilot system

Claims

1. a first system in which electric power from a first power source is supplied to a first load including at least one of a steering motor and an electric brake; a second system in which the power of the second power source is supplied to a second load including at least one of a steering motor and an electric brake; an inter-system switch that connects or disconnects the first system and the second system; a power supply switch that connects or disconnects the second power supply and the second system; a control unit that performs normal control to connect the inter-system switch and turn off the power supply switch when the first system and the second system are normal, and that performs abnormality detection control to detect an abnormality in the first system or the second system based on the voltages of the first system and the second system by turning off the inter-system switch and connecting the power supply switch when a power failure in the first system or the second system is detected based on the voltages of the first system and the second system; Equipped with The control unit is when no abnormality is detected in the first system and the second system by the abnormality detection control, switching to the normal control, and storing in a storage unit, at that time, an amount of voltage drop in the second system until the power supply switch is connected and cut off, as an amount of voltage drop in the second power supply; When charging the second power source, the second power source is charged until the voltage becomes equal to or greater than a voltage obtained by adding the amount of decrease to a drive voltage corresponding to an amount of power required to drive the second load and complete evacuation travel control after the power failure is detected. A power supply device comprising:

2. The control unit: When the abnormality is detected in the first system by the abnormality detection control, the second system supplies power to the second load, thereby performing an evacuation travel control during an automatic driving operation. When the second power source is equal to or higher than a voltage obtained by adding the driving voltage to the amount of decrease, a permission notice is issued to a vehicle control device to permit automatic driving.

2. The power supply device according to claim 1 .

3. The storage unit is An initial value of the decrease amount is stored in advance, The control unit is updating the initial value based on an actual value of the decrease amount measured when the abnormality detection control is performed; 3. The power supply device according to claim 1 or 2.

4. A power supply device according to any one of claims 1 to 3; a vehicle control device that performs automatic driving by operating the first load and the second load; Equipped with The vehicle control device includes: permitting the automatic operation when the voltage of the second power source is equal to or higher than the voltage obtained by adding the amount of decrease to the driving voltage; An autonomous driving system that features:

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