In-vehicle power supply device, in-vehicle power supply control method, and in-vehicle power supply control program

Abstract

To provide an on-vehicle power source device and an on-vehicle power source control method which enable a vehicle to perform safe evacuation travel even when an ignition line is disconnected while the vehicle is traveling.SOLUTION: An on-vehicle power source device comprises a first system, a second system, an inter-system switch and a control section. In the first system, electric power of a first power source is supplied to a first load for automatic operation. In the second system, electric power of a second power source is supplied to a second load for the automatic operation. The inter-system switch is capable of connecting and disconnecting the first system to and from the second system. When detecting a power supply failure in the first system, the control section disconnects the inter-system switch and causes the second system to enable the vehicle to perform evacuation travel. When detecting that an ignition is turned off and the vehicle is under automatic operation, the control section prohibits a process to be performed when the ignition is turned off.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The disclosed embodiments relate to an in-vehicle power supply device and an in-vehicle power supply control method.

Background Art

[0002] Conventionally, even if a power failure occurs during vehicle travel, 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 a ground fault occurs in one power supply system, power is supplied from the other power supply to in-vehicle devices (loads).

[0003] For example, the redundant power supply system includes a first system that supplies power from the first power supply to the first load, and a second system that supplies power from the second power supply to a second load having the same function as the first load. When a ground fault occurs in one of the first system and the second system, the redundant power supply system performs fail-safe control by the other system (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the redundant power supply system, for example, when the ignition line is disconnected during automatic driving of the vehicle, the in-vehicle power supply device erroneously determines that the operation is turned off and stops the operation. After that, even if a ground fault occurs, the vehicle cannot be driven to a safe place.

[0006] One aspect of the embodiment is made in view of the above, and an object thereof is to provide an in-vehicle power supply device and an in-vehicle power control method capable of safely retreating and running a vehicle even if the ignition line is disconnected during automatic driving of the vehicle.

Means for Solving the Problems

[0007] The in-vehicle power supply device according to one aspect of the embodiment includes a first system, a second system, an inter-system switch, and a control unit. The first system supplies the power of the first power source to the first load for automatic driving. The second system supplies the power of the second power source to the second load for automatic driving. The inter-system switch can connect and disconnect the first system and the second system. When the control unit detects a power failure in the first system, it shuts off the inter-system switch , forward and causes the second system to perform the perform a retreating drive operation . When the control unit detects that the ignition is off and the vehicle is in automatic driving If so 、 check whether another control device mounted on the vehicle has detected ignition off. When the other control device has detected ignition off, the control unit proceeds to the process performed at the time of ignition off. When the other control device has not detected ignition off, the control unit prohibits the process performed at the time of ignition off 。

Advantages of the Invention

[0008] The in-vehicle power supply device and the in-vehicle power control method according to one aspect of the embodiment have the effect of being able to safely retreat and run the vehicle even if the ignition line is disconnected during automatic driving of the vehicle.

Brief Description of the Drawings

[0009] [Figure 1] FIG. 1 is an explanatory diagram showing a configuration example of an in-vehicle power supply device according to an embodiment. [Figure 2] FIG. 2 is an explanatory diagram showing an operation example of an in-vehicle power supply device according to an embodiment. [Figure 3] FIG. 3 is an explanatory diagram showing an operation example of an in-vehicle power supply device according to an embodiment. [Figure 4] FIG. 4 is an explanatory diagram showing an operation example of an in-vehicle power supply device according to a comparative example. [Figure 5] FIG. 5 is an explanatory diagram showing an operation example of an in-vehicle power supply device according to an embodiment. [Figure 6] FIG. 6 is a flowchart showing an example of processing executed by a control unit of an in-vehicle power supply device according to an embodiment.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of an in-vehicle power supply device and an in-vehicle power supply control method will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited by the embodiments shown below. FIG. 1 is an explanatory diagram showing a configuration example of an in-vehicle power supply device according to an embodiment.

[0011] [1. Configuration of In-Vehicle Power Supply Device According to Embodiment] As shown in FIG. 1, an in-vehicle power supply device 1 according to an embodiment is connected to a first power supply 10, a host control device (hereinafter referred to as “host ECU: Electronic Control Unit”) 100, a first load 101, and a second load 102. Further, the in-vehicle power supply device 1 is connected to an ignition (hereinafter referred to as “IG”) switch 103, a display device 104, and a plurality of ECUs 105.

[0012] The host ECU 100 is a control device that comprehensively controls the entire vehicle. The host ECU 100 executes, for example, automatic driving control and evacuation driving control by automatic driving. When the vehicle start operation is performed by the user, the IG switch 103 outputs a signal indicating that the vehicle is starting to the in-vehicle power supply device 1. When the vehicle end operation is performed by the user, the IG switch 103 stops outputting a signal indicating that the vehicle is starting.

[0013] The display device 104 is a liquid crystal display provided in the vehicle interior and displays various information to the user. Each ECU 105 is a control device that controls the operations of various electronic devices provided in the vehicle. For example, the ECU 105 controls the operations of a motor for driving the vehicle, a steering motor, and an electric brake device.

[0014] The first load 101 and the second load 102 include loads 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. Also, the first load 101 includes general loads such as an air conditioner, an audio system, a video system, various lights, etc.

[0015] The second load 102 includes at least devices that operate during autonomous driving, such as a steering motor, an electric brake device, an in-vehicle camera, and a radar. The first load 101 and the second load 102 are operated by the electric power supplied from the in-vehicle power supply device 1. The upper-level ECU 100 operates the first load 101 and the second load 102 to perform automatic driving control, evacuation driving control, etc. of the vehicle.

[0016] The first power source 10 includes a generator 11 and a lead battery (hereinafter referred to as "PbB12"). The generator 11 is a device that converts the regenerative energy of the vehicle into electric power for power generation. Note that the generator 11 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. The generator 11 performs charging of the PbB12, power supply to the first load 101 and the second load 102, and charging of the second power source 20.

[0017] The in-vehicle power supply device 1 includes a second power source 20, a control unit 3, an inter-system switch 4, and a current sensor 5. A current sensor 5 is connected between the inter-system switch 4 and the first power source 10 and the first load 101. The current sensor 5 detects the current flowing through the inter-system switch 4 and outputs the detection result to the control unit 3.

[0018] The second power source 20 includes, for example, a lithium-ion battery (hereinafter referred to as "LiB21"). The second power source 20 is a backup power source when the power supply from the first power source 10 becomes unavailable.

[0019] Such in-vehicle power supply device 1 includes a first system 110 that supplies power from a first power source 10 to a first load 101, and a second system 120 that supplies power from a second power source 20 to a second load 102. The inter-system switch 4 is connected to connect and disconnect the first system 110 and the second system 120.

[0020] Thereby, even if a power failure occurs in one of the first system 110 and the second system 120, the in-vehicle power supply device 1 can turn off the inter-system switch 4 and supply power from the other system, so that the vehicle can be retreated and stopped to a safe place.

[0021] The control unit 3 includes a microcomputer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and various circuits. The control unit 3 controls the operation of the in-vehicle power supply device 1 by the CPU executing a program stored in the ROM using the RAM as a work area.

[0022] Note that the control unit 3 may be configured by hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The control unit 3 controls the inter-system switch 4 based on the detection result input from the current sensor 5, thereby supplying power from the first power source 10 or the second power source 20 to the first load 101 and the second load 102.

[0023] [2. Normal operation of the in-vehicle power supply device according to the present disclosure] As shown in FIG. 2, during normal operation when the first power source 10 and the second power source 20 are not defective, the control unit 3 connects the inter-system switch 4 and supplies power from the first power source 10 to the first load 101 and the second load 102. In such an in-vehicle power supply device 1, a ground fault 200 may occur during normal operation. In the example shown in FIG. 2, a ground fault 200 has occurred in the first system 110. In such a case, the control unit 3 performs an operation during ground fault occurrence.

[0024] [Operation during ground fault occurrence] Based on the detection result input from the current sensor 5, the control unit 3 detects the occurrence of the ground fault 200. When the current detected by the current sensor 5 is an overcurrent exceeding the ground fault threshold value, the control unit 3 detects that a ground fault has occurred in the first system 110 or the second system 120.

[0025] Furthermore, when the overcurrent flows from the second system 120 to the first system 110, the control unit 3 determines it as a ground fault 200 of the first system 110. Also, when the overcurrent flows from the first system 110 to the second system, the control unit 3 determines it as a ground fault of the second system 120.

[0026] When a ground fault occurs, if the connection of the inter-system switch 41 is maintained, the power charged in the first power supply 10 and the second power supply 20 is discharged, and the vehicle cannot be made to perform an evacuation run. Therefore, as shown in FIG. 3, when the control unit 3 detects the occurrence of, for example, the ground fault 200 which is a power supply failure, the control unit 3 cuts off the inter-system switch 4, and causes the second system 120 to supply power to the second load 102 to make the vehicle perform an evacuation run. When it is detected that a ground fault has occurred in the second system 120, the inter-system switch 4 is cut off, and the first system 110 supplies power to the first load 101 to make the vehicle perform an evacuation run.

[0027] [Operation of in-vehicle power supply device related to proportionality] Here, the problems of a general in-vehicle power supply device 1a related to proportionality will be described. As shown in FIG. 4, in the in-vehicle power supply device 1a, for example, when a disconnection 300 occurs in the IG line during automatic driving of the vehicle, a signal indicating that the vehicle is starting is no longer input from the IG switch 103 to the control unit 3a. This state is the same as the state when the user performs an end operation of the vehicle.

[0028] Therefore, the control unit 3a erroneously determines that the user has performed an end operation on the vehicle and shifts to the process performed when the IG is off. For example, the control unit 3a executes the vehicle end process and stops the operation. For this reason, the control unit 3a cannot cut off the inter-system switch 4 even if a ground fault 200 occurs in the first system 110, for example.

[0029] As a result, in the in-vehicle power supply device 1a, discharge occurs from the first power supply 10 and the second power supply 20 to the location where the ground fault 200 occurs, and the first load 101 and the second load 102 do not operate, so the vehicle cannot be made to perform an evacuation run. Therefore, the in-vehicle power supply device 1 according to the embodiment performs control to make the vehicle perform an evacuation run even if a disconnection 300 occurs in the IG line during automatic driving.

[0030] [5. Operation of the in-vehicle power supply device according to the present disclosure] When the control unit 3 of the in-vehicle power supply device 1 detects that the IG is off, if it is during automatic driving, the process performed when the IG is off is prohibited. For this reason, the control unit 3 does not perform the vehicle end process and continues the operation.

[0031] Thereby, as shown in FIG. 5, the in-vehicle power supply device 1 detects a disconnection 300 in the IG line and detects that the IG is off, and then, for example, if a ground fault 200 occurs in the first system 110 during automatic driving, the operation is continued and the inter-system switch 4 is turned off.

[0032] Thereby, the in-vehicle power supply device 1 can supply power to the second load 102 by the second system 120 and make the vehicle perform an evacuation run. Next, an example of the specific process executed by the control unit 3 of the in-vehicle power supply device 1 will be described.

[0033] [6. Process executed by the control unit of the in-vehicle power supply device according to the present disclosure] During normal operation, the control unit 3 of the in-vehicle power supply device 1 executes the process shown in FIG. 6. Specifically, during normal operation, the control unit 3 first determines whether or not it has detected that the IG is off (step S101). If the control unit 3 does not detect that the IG is off (step S101, No), the process ends and the process starts again from step S101.

[0034] If the control unit 3 detects that the IG is off (step S101, Yes), it communicates with the upper ECU 100 to determine whether or not it is in the middle of autonomous driving (step S102). If the control unit 3 is not in the middle of autonomous driving (step S102, No), that is, if it is in the middle of manual driving, the process proceeds to the process of step S109 to be performed when the IG is off.

[0035] In this way, when the in-vehicle power supply device 1 detects an IG off during manual driving, where there is a high possibility of the IG off being due to a manual operation by the user, it can appropriately execute the process to be performed when the IG is off according to the user's operation.

[0036] If the control unit 3 is in the middle of autonomous driving (step S102, Yes), it determines whether or not the IG switch 103 has been forcibly terminated (step S103). Here, the normal start operation and the normal end operation are, for example, operations of pressing the IG switch 103 once. In contrast, the forced termination operation is an operation different from the normal end operation, such as an operation of pressing and holding the IG switch 103 for several seconds or an operation of rapidly pressing the IG switch 103. Note that the switch for the forced termination operation may be a switch other than the IG switch 103. If another switch is used for forced termination, it is possible to forcibly terminate even if a disconnection occurs in the IG line.

[0037] If the control unit 3 determines that the IG switch 103 has been forcibly terminated (step S103, Yes), the process proceeds to the process of step S109 to be performed when the IG is off. Thereby, when an emergency occurs and the user performs a forced termination operation, for example, the in-vehicle power supply device 1 can appropriately execute the process to be performed when the IG is off according to the user's forced termination operation even when it is in the middle of autonomous driving.

[0038] When the IG switch 103 has not been forced to end the operation (step S103, No), the control unit 3 communicates with other ECUs 105 to determine whether other ECUs 105 have also detected the IG off (step S104).

[0039] When the other ECUs 105 have also detected the IG off (step S104, Yes), the control unit 3 proceeds to the process of step S109 performed at the time of IG off. In this way, when the in-vehicle power supply device 1 detects that other ECUs 105 have also detected the IG off and it is highly likely that it is not a disconnection 300 of the IG line, the process performed at the time of IG off can be appropriately executed.

[0040] If there are multiple other ECUs 105, if all ECUs detect the IG off, it is determined that it is not a disconnection 300 of the IG line but a normal IG off by user operation, and the process proceeds to the process of step S109 performed at the time of IG off. In other words, if one or more of the other ECUs 105 detect the IG off and the remaining ECUs do not detect the IG off, there is a possibility of a disconnection of the IG line, so in consideration of safety, the process of step S109 performed at the time of IG off is not proceeded to.

[0041] When the other ECUs 105 do not detect the IG off (step S104, No), the control unit 3 prohibits the process performed at the time of IG off (step S105). When the control unit 3 detects the IG off, if it is in the middle of autonomous driving, it immediately prohibits the process performed at the time of IG off. Here, to prohibit the process performed at the time of IG off, it is only necessary not to transfer to step S109, which is the termination process executed when the IG off is detected. Therefore, step S105 may not be necessary. When it is determined as NO in step S104, instead of proceeding to the termination process of step S109, proceeding to step S106 and continuing the operation corresponds to prohibiting the process performed at the time of IG off. After that, the control unit 3 continues the redundant power supply system operation (step S106). Also, in step S106, the control unit 3 continues the autonomous driving to the upper ECU 100 and causes the vehicle to perform a retreating drive.

[0042] In this way, when the in-vehicle power supply device 1 detects the IG, if it is during automatic driving, the processing performed when the IG is turned off is prohibited. Therefore, for example, when the detection of the IG being turned off is caused by the disconnection 300 of the IG line, the vehicle can be safely retreated and driven.

[0043] After that, the control unit 3 notifies the upper ECU 100 and the vehicle user of the detection of the IG being turned off during automatic driving (step S107). When the control unit 3 notifies the user, for example, it displays and notifies on the display device 104 that the detection of the IG being turned off during automatic driving has been detected.

[0044] Thereby, when the upper ECU 100 is notified, for example, of the detection of the IG being turned off during automatic driving, it can switch from the automatic driving control to the retreat driving control and safely stop the vehicle. Also, when the user is notified of the detection of the IG being turned off during automatic driving, the user can switch from automatic driving to manual driving and safely stop the vehicle.

[0045] After that, the control unit 3 determines whether or not the automatic driving has ended (step S108). If the automatic driving has not ended (step S108, No), the process proceeds to step S106. Thereby, the in-vehicle power supply device 1 can continue the safe retreat driving by continuing the operation of the redundant power supply system until the automatic driving ends.

[0046] When the control unit 3 determines that the automatic driving has ended (step S108, Yes), it executes the processing performed when the IG is turned off. For example, the control unit 3 stops the operation of the redundant power supply system (step S109) and ends the process.

[0047] As described above, when the in-vehicle power supply device 1 detects an IG off, if the vehicle is in autonomous driving, it does not shift to the process performed at the time of IG off, but continues the autonomous driving of the vehicle. When the autonomous driving ends, it shifts to the process performed at the time of IG off. Thereby, for example, when the in-vehicle power supply device 1 detects an IG off caused by a disconnection 300 of the IG line, the vehicle can be safely evacuated and stopped by autonomous driving.

[0048] (Modification Examples 1 to 3) In the process of FIG. 6, when an IG off is detected (step S101, Yes), if it is in autonomous driving (step S102, Yes), as conditions for prohibiting the process performed at the time of IG off, two conditions of no forced termination operation (step S103, No) and other ECUs not detecting an IG off (step S104, No) are further added. This is to improve the determination accuracy assuming that the IG off is due to a disconnection of the IG line.

[0049] In Modification Example 1, the forced termination operation determination process in step S103 may not be provided. This is effective when the vehicle does not have a forced termination function.

[0050] In Modification Example 2, the confirmation process of other ECUs in step S104 may not be provided. Thereby, the processing load can be reduced.

[0051] In Modification Example 3, both step S103 and step S104 may not be provided. Thereby, the effects of Modification Example 1 and Modification Example 2 can be achieved.

[0052] (Modification Example 4) In the above-described embodiment, when an IG off is detected (step S101, Yes), if it is in autonomous driving (step S102, Yes), the process performed at the time of IG off is not shifted to. However, even during autonomous driving, if the vehicle is stopped, it is conceivable that the driver turns off the IG for some reason.

[0053] Therefore, as a modification 4, when IG off is detected (step S101, Yes), if the vehicle is in autonomous driving and moving (for example, the vehicle speed is equal to or higher than a predetermined speed), the process to be performed at the time of IG off is not shifted to. This is because the possibility that the driver turns off the IG during traveling is extremely low, and when IG off is detected during traveling, there is a high possibility that the IG line is disconnected.

[0054] As a process, between (step S102, Yes) and (step S103) in FIG. 6, a determination step of "Is the vehicle speed equal to or higher than a predetermined speed?" may be inserted. If Yes, the process proceeds to step S103, and if No, the process proceeds to step S109. Thereby, the in-vehicle power supply device 1 can more reliably detect IG off caused by disconnection 300 of the IG line.

[0055] Further effects and modifications can be easily derived by those skilled in the art. For this reason, the broader aspects of the present invention are not limited to the specific details and representative embodiments described and represented as above. Therefore, 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.

Explanation of Signs

[0056] 1, 1a In-vehicle power supply device 10 First power supply 11 Generator 12 PbB 20 Second power supply 21 LiB 3, 3a Control unit 4 Inter-system switch 5 Current sensor 100 Upper ECU 101 First load 102 Second load 103 IG switch 104 Display device 105 ECU 110 First system 120 Second system

Claims

1. A first system in which the power of a first power source is supplied to a first load for autonomous driving; A second system in which the power of a second power source is supplied to a second load for autonomous driving; An inter-system switch capable of connecting and disconnecting the first system and the second system; A control unit that, when detecting a power failure in the first system, shuts off the inter-system switch and causes the vehicle to perform an evacuation drive using the second system and comprising: The control unit: When detecting that the ignition is off, if the vehicle is in autonomous driving, it checks with other control devices mounted on the vehicle whether the ignition is detected as being off, When the other control device detects that the ignition is off, it proceeds to the process to be performed when the ignition is off, and when the other control device does not detect that the ignition is off, it prohibits the process to be performed when the ignition is off An in-vehicle power supply device characterized by the above.

2. An in-vehicle power supply control method in which a control device controls an in-vehicle power supply device including a first system in which the power of a first power source is supplied to a first load for autonomous driving, a second system in which the power of a second power source is supplied to a second load for autonomous driving, and an inter-system switch capable of connecting and disconnecting the first system and the second system, When detecting a power failure in the first system, the inter-system switch is shut off and the vehicle is caused to perform an evacuation drive using the second system, When detecting that the ignition is off, if the vehicle is in autonomous driving, it checks with other control devices mounted on the vehicle whether the ignition is detected as being off, When the other control device detects that the ignition is off, it proceeds to the process to be performed when the ignition is off, and when the other control device does not detect that the ignition is off, it prohibits the process to be performed when the ignition is off An in-vehicle power supply control method characterized by the above.

3. An in-vehicle power supply control program for causing a computer to execute control of an in-vehicle power supply device including a first system in which the power of a first power source is supplied to a first load for autonomous driving, a second system in which the power of a second power source is supplied to a second load for autonomous driving, and an inter-system switch capable of connecting and disconnecting the first system and the second system, When detecting a power failure in the first system, the inter-system switch is shut off and the vehicle is caused to perform an evacuation drive using the second system, When ignition-off is detected, if the vehicle is in the autonomous driving state, it is confirmed with other control devices mounted on the vehicle whether ignition-off is detected. When the other control device has detected ignition-off, the process to be performed at the time of ignition-off is shifted to, and when the other control device has not detected ignition-off, the process to be performed at the time of ignition-off is prohibited. An in-vehicle power supply control program characterized by the above.

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