JP7707040B2 - Power supply device and control method - Google Patents

Description

The disclosed embodiments relate to a power supply device and a control method.

There is a system that switches the power source to a sub-battery if the voltage of the main battery drops while updating the program of the ECU (Electronic Control Unit) installed in the vehicle using power from the main battery (see, for example, Patent Document 1).

JP 2003-191803 A

However, for example, in the case of a redundant power supply system having a first system that supplies power to the ECU from a first power supply and a second system that supplies power to the ECU from a second power supply, it is not desirable to consume too much power from the second power supply for program updates.

One aspect of the embodiment has been made in consideration of the above, and aims to provide a power supply device and a control method that can reduce the power of the second power supply used for updating a program.

The power supply device according to one aspect of the embodiment includes a first system, a second system, a connection unit, and a control unit. The first system supplies power from a first power source to a first load including a microcomputer. The second system supplies power from a second power source to a second load including the microcomputer. The connection unit can connect and disconnect the first system and the second system. When a program of the microcomputer is updated, if the voltage information of the first system is equal to or greater than a predetermined value, the control unit disconnects the connection unit to supply power from the first power source to the microcomputer, and if the voltage information is less than the predetermined value, the control unit disconnects the connection unit to supply power from the first power source and power from the second power source to the microcomputer.

The power supply device and control method according to one aspect of the embodiment have the effect of reducing the power of the second power supply used for updating a program.

FIG. 1 is an explanatory diagram illustrating an example of the configuration of a power supply device according to an embodiment. FIG. 2 is an explanatory diagram showing an example of the operation of the power supply device according to the embodiment. FIG. 3 is an explanatory diagram showing an example of the operation of the power supply device according to the embodiment. FIG. 4 is an explanatory diagram showing an example of the operation of the power supply device according to the embodiment. FIG. 5 is an explanatory diagram showing an example of the operation of the power supply device according to the embodiment. FIG. 6 is a flowchart illustrating an example of a process executed by the control unit of the power supply device according to the embodiment.

Embodiments of a power supply device and a power supply control method will be described in detail below with reference to the attached drawings. Note that the present invention is not limited to the embodiments described below. The following description will be given using an example of a power supply device that is mounted on a vehicle with an autonomous driving function and supplies power to a load, but the power supply device according to the embodiment may also be mounted on a vehicle that does not have an autonomous driving function.

The power supply device according to the embodiment is installed in an electric vehicle, a hybrid vehicle, or an engine vehicle that runs on an internal combustion engine. The power supply device according to the embodiment may be installed in any device that has a first power source and a second power source, and that performs fail-over-operation (FOP) by backing up the first power source with the second power source in the event of a power failure in the first power source.

[1. Power supply configuration]
A vehicle equipped with a power supply device according to the embodiment has a function of updating (hereinafter referred to as "reprogramming") a program of a microcomputer (hereinafter referred to as "microcomputer") built into an ECU (Electronic Control Unit) equipped in the vehicle while the vehicle is parked. Note that "while parked" here refers to a period when the vehicle's IG (ignition switch) is off.

The power supply device according to the embodiment supplies power to all on-board devices including the ECU while the IG is on, and during reprogramming, supplies power to the ECU having the microcomputer to be reprogrammed and to the on-board devices related to the reprogramming. FIG. 1 is an explanatory diagram showing an example of the configuration of the power supply device 1 according to the embodiment. Note that FIG. 1 shows the state of the power supply device 1 while the IG is off.

As shown in FIG. 1, the power supply device 1 according to the embodiment is connected to a first power source 10, an automatic driving control device 100, and a reproducibility control device 130. The reproducibility control device 130 is connected to a server device 131 via a communication network N such as the Internet so as to be able to communicate wirelessly with the server device 131.

When the latest program for the microcomputer of a certain ECU is released, the server device 131 transmits the latest program to the reproductive control device 130 via the communication network N. When the reproductive control device 130 receives the latest program, it updates the program of the ECU to be updated to the latest program.

The power supply device 1 is connected to the first ECU 101 and the second ECU 102, which are an example of a first load, and the first ECU 101 and the second ECU 102, which are an example of a second load. The power supply device 1 is also connected to general loads (not shown) other than the first ECU 101 and the second ECU 102, and supplies power to each general load.

The power supply device 1 includes a first system 110 and a second system 120. The first system 110 supplies power from the first power source 10 to the first ECU 101 via the first load switch 43. The first system 110 supplies power from the first power source 10 to the second ECU 102 via the first load switch 44.

The first load switch 43 is a switch that can connect and disconnect the first system 110 and the first ECU 101. The first load switch 44 is a switch that can connect and disconnect the first system 110 and the second ECU 102.

The second system 120 supplies power from the second power source 20 (described later) to the first ECU 101 via the battery switch 42 and the second load switch 45. The second system 120 supplies power from the second power source 20 (described later) to the second ECU 102 via the battery switch 42 and the second load switch 46.

The battery switch 42 is a switch that can connect and disconnect the second power source 20 and the second system 120 described below. The second load switch 45 is a switch that can connect and disconnect the second system 120 and the first ECU 101. The second load switch 46 is a switch that can connect and disconnect the second system 120 and the second ECU 102.

The first ECU 101 and the second ECU 102 are loads for automatic driving, and each has a control microcomputer. For example, the first ECU 101 and the second ECU 102 are a steering motor control device, an electric brake device, an in-vehicle camera, a radar, etc. that operate during automatic driving. The general loads mentioned above include, for example, a display, an air conditioner, an audio, a video, and various lights. Power from the first system 110 and power from the second system 120 to the first ECU 101 and the second ECU 102 are supplied by a diode OR within each ECU.

The first ECU 101, the second ECU 102, and the general loads operate using power supplied from the power supply device 1. The automatic driving control device 100 is a device that operates the first ECU 101, the second ECU 102, and the like to control the automatic driving of the vehicle.

When the power supply device 1 is installed in an engine vehicle, the first power source 10 includes a generator 12 and a lead battery (hereinafter referred to as "PbB11"). Note that the battery of the first power source 10 may be any secondary battery other than PbB11.

The generator 12 is, for example, an alternator that converts the kinetic energy of a traveling vehicle into electricity to generate power. The generator 12 charges the PbB 11 and the second power source 20 with the generated power. The generator 12 also supplies power to the first ECU 101, the second ECU 102, and general loads. The PbB 11 supplies power to the first ECU 101, the second ECU 102, and general loads.

When the power supply device 1 is installed in an electric vehicle or a hybrid vehicle, the first power source 10 includes a DC/DC converter (hereinafter referred to as "DC/DC") and PbB11. In this case, the DC/DC is connected to a generator and a high-voltage battery with a higher voltage than PbB11, and steps down the voltage of the generator and the high-voltage battery and outputs it to the first system 110. The generator is, for example, an alternator. The high-voltage battery is, for example, a battery for driving the vehicle that is installed in an electric vehicle or a hybrid vehicle.

The power supply device 1 includes a second power supply 20, a control unit 3, a connection unit 41, a battery switch 42, first load switches 43 and 44, second load switches 45 and 46, and a voltage sensor 5. The second power supply 20 is a backup power supply in case the first power supply 10 is unable to supply power.

The second power source 20 includes a lithium ion battery (hereinafter referred to as "LiB21"). Note that the battery of the second power source 20 may be any secondary battery other than LiB21.

The connection unit 41 is a switch that can connect and disconnect the first system 110 and the second system 120. The battery switch 42 is a switch that can connect and disconnect the second power source 20 to the second system 120. The voltage sensor 5 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 control unit 3 includes a microcomputer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc., and various circuits. The control unit 3 may also be configured with hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

The control unit 3 controls the connection unit 41, the battery switch 42, the first load switches 43 and 44, and the second load switches 45 and 46 by the CPU executing a program stored in the ROM using the RAM as a working area. When the IG is off, the control unit 3 cuts off the connection unit 41, the battery switch 42, the first load switches 43 and 44, and the second load switches 45 and 46, as shown in FIG. 1.

When the power supply device 1 is in normal operation, the control unit 3 turns on the connection unit 41, the first load switches 43 and 44, and the second load switches 45 and 46, and turns off the battery switch 42. The control unit 3 then detects a ground fault in the first system 110 based on the detection result input from the voltage sensor 5. A specific example of a method for detecting a ground fault by the control unit 3 will be described later.

When the control unit 3 detects a ground fault in the first system 110, 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, it may notify the automatic driving control device 100 that automatic driving is not possible. When the control unit 3 does not detect a ground fault in the first system 110, it may notify the automatic driving control device 100 that automatic driving is possible.

When a ground fault occurs in the first system 110, the control unit 3 cuts off the connection unit 41, turns on the battery switch 42, and supplies power from the second power source 20 to the first ECU 101 and the second ECU 102.

As a result, even if a ground fault occurs in the first system 110 during autonomous driving, the power supply device 1 can use the second system 120 and have the vehicle evacuate to a safe place and stop using the autonomous driving control device 100. Next, an example of the operation of the power supply device 1 will be described.

2. Normal operation of the power supply
2, the control unit 3 turns on the first load switches 43, 44 and the second load switches 45, 46. The control unit 3 turns on the connection unit 41 with the battery switch 42 cut off, and supplies power from the first power source 10 to the first ECU 101, the second ECU 102, and the general loads.

[3. Operation of the power supply device when a ground fault occurs in the first system]
3, in the power supply device 1, a ground fault 200 may occur in the first system 110. When the ground fault 200 occurs in the first system 110, an overcurrent flows toward the ground fault point, causing the voltage of the first system 110 to drop.

Therefore, when the voltage of the first system 110 detected by the voltage sensor 5 falls below the ground fault threshold, the control unit 3 determines that a ground fault has occurred in the first system 110. Then, when the control unit 3 detects a ground fault 200 in the first system 110, it cuts off the connection unit 41 and the first load switches 43 and 44, and turns on the battery switch 42 to supply power from the second power source 20 to the first ECU 101 and the second ECU 102.

Then, the control unit 3 notifies the automatic driving control device 100 that a ground fault 200 has occurred in the first system 110. As a result, the automatic driving control device 100 can operate the first ECU 101 and the second ECU 102 using power supplied from the second power source 20, and can evacuate the vehicle to a safe place and stop it.

In this way, since the second power source 20 functions as a backup power source in the event that a ground fault 200 occurs in the first system 110, it is desirable to avoid using power as much as possible for purposes other than evacuation driving, such as updating the programs of the first ECU 101 and the second ECU 102. For this reason, the control unit 3 performs reprogramming so that the power of the second power source 20 used for updating the programs can be reduced.

[4. Power supply operation during repro]
4, for example, when the latest program P of the first ECU 101 is made public, the server device 131 transmits the latest program P to the reproductor control device 130 by wireless communication via the communication network N. Note that when the server device 131 is connected to the reproductor control device 130 by a communication cable in a maintenance shop or the like, it transmits the latest program P to the reproductor control device 130 by wired communication.

The reproduction control device 130 is in a sleep state while the IG is off, and wakes up in response to a communication request from the server device 131, receiving the latest program P from the server device 131 using power supplied from the PbB 11. When the reproduction control device 130 receives the latest program P, it transmits a reproduction start signal S and ECU information of the reproduction target (in this case, the first ECU 101) to the control unit 3.

When the control unit 3 receives the replay start signal S, it determines whether the vehicle is parked or not, and if so, obtains voltage information of the first system 110 from the voltage sensor 5 and determines whether the voltage information is equal to or greater than a predetermined value.

For example, the control unit 3 acquires the voltage value of the first power source 10 as voltage information, and determines whether the voltage value of the first power source 10 is equal to or greater than a predetermined value. In this case, the predetermined value is, for example, a lower limit voltage at which a program update can be performed normally. This lower limit is a value with a margin higher than the voltage at which the microcomputer stops operating.

The control unit 3 may also be configured to acquire, as voltage information, a value indicating the level of the state of charge of the first power source 10 from the first power source 10 via the line 13. The value indicating the level of the state of charge of the first power source 10 is, for example, the SOC (State Of Charge) of PbB11. In this case, the predetermined value is, for example, the lower limit of the SOC at which the program update can be performed normally.

When the voltage information of the first power source 10 is equal to or greater than a predetermined value, the control unit 3 cuts off the connection unit 41, turns on the first load switch 43, and cuts off the first load switch 44 and the second load switches 45 and 46 to supply power from the first power source 10 to the first ECU 101 that is the reprogramming target. The reprogramming control device 130 then transmits the latest program P to the first ECU 101 to perform the reprogramming.

During this period, the reproduc- tion control device 130 can continue normal reproduc- tion without interruption because the voltage information of the first power source 10 is above a predeter- mined level. In addition, the control unit 3 shuts off the battery switch 42 during this period, preventing the use of power from the second power source for reproduc- tion.

Furthermore, if the control unit 3 is configured to acquire the voltage value of the first power source 10 as the voltage information, it can supply the first ECU 101 with a voltage that allows reproducibility to be achieved, and normal reproducibility can be continued without interruption. Furthermore, even if the control unit 3 is configured to acquire a value indicating the level of the charge state of the first power source 10 as the voltage information, it can still continue normal reproducibility without interruption.

In addition, when the voltage information is equal to or greater than a predetermined value, the control unit 3 cuts off the second load switches 45, 46. Therefore, even if, for example, the battery switch 42 is stuck on, it is possible to prevent power supply from the second power source 20 to the first ECU 101 and the second ECU 102.

In addition, when the voltage information is equal to or greater than a predetermined value, the control unit 3 turns on the first load switch 43 and turns off the first load switch 44, thereby preventing unnecessary power supply to the second ECU 102 that is unrelated to the repro.

After that, when the power of the first power source 10 decreases due to reprocessing and the acquired voltage information falls below a predetermined value, the control unit 3 cuts off the connection unit 41 and supplies the power of the first power source 10 and the power of the second power source 20 to the first ECU 101 that is the target of reprocessing.

Specifically, as shown in FIG. 5, the control unit 3 cuts off the connection unit 41, turns on the battery switch 42, and turns on the second load switch 45 to supply power from the first power source 10 and the second power source 20 to the first ECU 101 that is the reprogramming target. The reprogramming control device 130 then transmits the latest program P to the first ECU 101 to continue the reprogramming.

At this time, because the voltage of the second power source 20 is higher than the voltage of the first power source 10 due to the voltage drop of the first power source 10, power is supplied from the second power source 20 to the first ECU 101 until the voltage of the second power source 20 drops to the voltage of the first power source 10. When the voltage of the second power source 20 drops to the same voltage as the first power source 10, power is thereafter supplied to the first ECU 101 from both the first power source 10 and the second power source 20.

As a result, even if the voltage information of the first system 110 falls below a predetermined value, the control unit 3 can supplement the power required for reprogramming of the first ECU 101 with the power of the second power source 20, so that the reprogramming can be completed normally.

In addition, the control unit 3 supplies power from the second power source 20 to the first ECU 101 only when the voltage information of the first system 110 falls below a predetermined value, and continues to supply power from the first power source 10 to the first ECU 101 during this period, thereby reducing the power of the second power source 20 used for reproducibility.

[5. Processing performed by the control unit]
Next, a process executed by the control unit 3 of the power supply device 1 according to the embodiment will be described with reference to Fig. 6. Fig. 6 is a flowchart showing an example of a process executed by the control unit 3 of the power supply device 1 according to the embodiment. The control unit 3 repeatedly executes the process shown in Fig. 6.

Specifically, as shown in FIG. 6, the control unit 3 first determines whether or not a reproduction start signal S has been received (step S101). If the control unit 3 determines that a reproduction start signal S has not been received (step S101, No), the control unit 3 ends the process and starts the process again from step S101.

When the control unit 3 determines that the repro start signal S has been received (step S101, Yes), it determines whether or not the vehicle is parked (step S102). When the control unit 3 determines that the vehicle is not parked (step S102, No), it repeats the determination process of step S102 until it determines that the vehicle is parked.

If the control unit 3 determines that the vehicle is parked (step S102, Yes), it determines whether the voltage information of the first system 110 is equal to or greater than a predetermined value (step S103). If the control unit 3 determines that the voltage information of the first system 110 is equal to or greater than a predetermined value (step S103, Yes), it shuts off the connection unit 41 (step S104) and shuts off the battery switch 42 (step S105).

Then, the control unit 3 supplies power from the first power source 10 to the ECU to be reprogrammed (step S106). At this time, the control unit 3 turns on the first load switch connected to the ECU to be reprogrammed, turns off the first load switch connected to the ECU that is not the target of reprogramming, and turns off all second load switches, and supplies power from the first power source 10 to the ECU to be reprogrammed.

Then, the control unit 3 determines whether or not re-progression is complete (step S107). If the control unit 3 determines that re-progression is not complete (step S107, No), the control unit 3 moves the process to step S103. If the control unit 3 determines that re-progression is complete (step S107, Yes), the control unit 3 ends the process and starts again from step S101.

In addition, in step S103, if the control unit 3 determines that the voltage information of the first system 110 is not equal to or greater than the predetermined value, that is, the voltage information is less than the predetermined value (step S103, No), it disconnects the connection unit 41 (step S108).

Then, the control unit 3 turns on the battery switch 42 (step S109) and supplies power from the first power source 10 and the second power source 20 to the ECU to be reprogrammed (step S110). At this time, the control unit 3 turns on the second load switch connected to the ECU to be reprogrammed and supplies power from the second power source 20 to the ECU to be reprogrammed. After that, the control unit 3 moves the process to step S107.

Further advantages and modifications may readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof.

1 Power supply device 10 First power supply 11 PbB
12 Generator 13 Line 20 Second power source 21 LiB
3 Control unit 41 Connection unit 42 Battery switch 43, 44 First load switch 45, 46 Second load switch 5 Voltage sensor 100 Automatic driving control device 101 First ECU
102 2nd ECU
130 Reproduction control device 131 Server device N Communication network P Latest program S Reproduction start signal

Claims (6)

a first system that supplies power from a first power source to a first load including a microcomputer;
a second system that supplies power from a second power source to a second load including the microcomputer;
a connection portion capable of establishing and interrupting electrical continuity between the first system and the second system;
a control unit that, when a program of the microcomputer is updated, cuts off the connection unit and supplies power from the first power source to the microcomputer if voltage information of the first system is equal to or higher than a predetermined value, and cuts off the connection unit and supplies power from the first power source and power from the second power source to the microcomputer if the voltage information is less than the predetermined value. a battery switch capable of connecting and disconnecting the second power supply and the second system;
The control unit is
2. The power supply device according to claim 1, wherein when the program is updated, if the voltage information of the first system is equal to or greater than the predetermined value, the battery switch is turned off, and if the voltage information is less than the predetermined value, the battery switch is turned on. a first load switch capable of connecting and disconnecting the first system and the microcomputer, and a second load switch capable of connecting and disconnecting the second system and the microcomputer,
The control unit is
3. The power supply device according to claim 2, wherein when the program is updated, if the voltage information of the first system is equal to or greater than the predetermined value, the first load switch is turned on and the second load switch is turned off, and if the voltage information is less than the predetermined value, the first load switch and the second load switch are turned on. the voltage information is a voltage value of the first power source,
4. The power supply device according to claim 1, wherein the predetermined value is a lower limit value of the voltage of the first power supply at which the program can be updated normally. the voltage information is a value indicating a state of charge of the first power source,
4. The power supply device according to claim 1, wherein the predetermined value is a lower limit value indicating a level of a charge state of the first power source at which the program can be updated normally. a first system that supplies power from a first power source to a first load including a microcomputer;
a second system that supplies power from a second power source to a second load including the microcomputer;
a connection portion capable of establishing and interrupting electrical continuity between the first system and the second system;
a control unit for controlling the connection unit of the power supply device,
When updating a program of the microcomputer, if the voltage information of the first system is equal to or higher than a predetermined value, the connection part is cut off and power from the first power source is supplied to the microcomputer;
When the voltage information is less than the predetermined value, the connection portion is cut off and power from the first power source and power from the second power source are supplied to the microcomputer.

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