JP7439713B2 - Mobile power system - Google Patents

Description

The technology disclosed herein belongs to the technical field related to power supply systems for mobile bodies.

In recent years, a large number of electronic devices are installed in moving objects such as automobiles. In line with this, the configuration of power supply to each electronic device is being considered.

For example, Patent Document 1 describes a first power source, a second power source for supplying power with a higher voltage than the first power source, and a voltage of the power output from the second power source to the voltage of the first power source. A circuit configuration for a vehicle, comprising: a step-down section that steps down the voltage, and in which power from a first power source and power from a second power source whose voltage has been stepped down by the step-down section are supplied to a main power supply line routed through the vehicle body. is disclosed.

In Patent Document 1, the second power source is installed at the rear of the vehicle, at least a portion of the main line is routed in the longitudinal direction of the vehicle, and the high voltage section is connected to the main power line at the end of the main line on the rear side of the vehicle. .

International Publication No. 2017/222077

By the way, in the vehicle circuit configuration described in Patent Document 1, each ECU (Electric Control Unit), which is a calculation device for controlling the electronic equipment of the vehicle, is connected in parallel to each other via a fuse box or the like. . The ECUs have different functions, and accordingly, their power consumption also differs. When connecting ECUs with large power consumption in parallel, it is necessary to route a thick main line throughout the vehicle as shown in Patent Document 1. This causes problems such as voltage drop and noise on the electric wire, which may adversely affect the functions of other ECUs.

The technology disclosed herein has been developed in view of this point, and its purpose is to create a mobile device that is unlikely to have a negative impact on each other, even if it has multiple arithmetic units with different power consumption. Our goal is to provide power supply systems.

In order to solve the above problem, the technology disclosed herein includes a first battery, a second battery capable of supplying power with a higher voltage than the first battery, and a power supply system for a mobile object. a DC/DC converter that is electrically connected to the first battery and the second battery and that steps down the voltage of the power supplied from the second battery to the voltage of the first battery; and a fuse box electrically connected to the downstream side of the DCDC converter, a plurality of sub-processing devices capable of transmitting control signals to devices included in the mobile object, and communicatively connected to the plurality of sub-processing devices, respectively; a central processing unit that centrally controls the plurality of sub-processing units, the sub-processing units are each electrically connected to the fuse box, and the central processing unit is electrically connected to the DCDC converter. The structure is such that:

That is, since the central processing unit centrally controls each sub-processing unit, its power consumption is considerably larger than that of each sub-processing unit. According to the above configuration, since the central processing unit is connected to the DC/DC converter without going through the fuse box, there is no need to route large diameter electric wires throughout the moving body. Further, by placing the DC/DC converter and the central processing unit close to each other, the total length of the electric wire from the battery to the central processing unit can be shortened. This allows a configuration in which the arithmetic devices are unlikely to have an adverse effect on each other.

Further, in the above configuration, power is supplied to each sub-processing device through a separate power supply path. Therefore, even if the electric wire between the first battery and the fuse box is disconnected, power is supplied to the central processing unit. Therefore, for example, if the central processing unit controls each device instead of each sub-processing unit, it is possible to suppress the influence of a power failure on the operation of the mobile object. Furthermore, even if the wire between the second battery and the DCDC converter is disconnected, the central processing unit can receive power from the first battery via the DCDC converter. Therefore, the operating state of the central processing unit can be maintained, and the influence on the operation of the moving object can be suppressed.

In the power supply system for the mobile object, the DCDC converter includes a switch system that controls on/off of power supply from the first and second batteries to the central processing unit, and the central processing unit The DC/DC converter is capable of communicating with the DC/DC converter, and is configured to turn off the switch system and turn off the power supply from the first and second batteries to the DC/DC converter when an abnormality is detected in the DC/DC converter. A configuration in which a control signal is output may also be used.

That is, since the central processing unit does not go through a fuse box, it is necessary to suppress failures due to abnormality in energization by itself. In the above configuration, the central processing unit itself outputs a control signal to the DC/DC converter to cut off the power supply when a power supply abnormality occurs, so that the power supply can be cut off quickly. Thereby, failure of the central processing unit can be appropriately suppressed.

In the power supply system for the mobile body, the DC/DC converter may be arranged near the central processing unit.

According to this configuration, by arranging the DCDC converter near the central processing unit, the electric wire between the DCDC converter and the central processing unit can be shortened. This makes it possible to further reduce the effects of voltage drop and noise on the wires. Further, since the electric wire between the DCDC converter and the central processing unit is short, power failure due to disconnection can be suppressed, and the influence on the mobile object can be suppressed.

In a power supply system for a mobile body in which a DC/DC converter is disposed near a central processing unit, the central processing unit is disposed at a position to the rear of the vehicle and directly below the instrument panel relative to the dash panel, and the DC/DC converter is configured to include: It may be arranged in a position near the rear of the vehicle in the engine room or motor room and at approximately the same height as the central processing unit.

According to this configuration, the DC/DC converter and the central processing unit are located close to each other, so that the electric wire between the DC/DC converter and the central processing unit can be considerably shortened. This makes it possible to further reduce the effects of voltage drop and noise on the wires.

As described above, according to the technology disclosed herein, even if there are a plurality of arithmetic units with different power consumptions, it is possible to make it difficult for them to adversely affect each other.

FIG. 1 is a configuration diagram showing a power supply system of a vehicle equipped with a power supply system according to an exemplary embodiment. FIG. 2 is a schematic configuration diagram of the power supply system viewed from the side of the vehicle. FIG. 3 is a perspective view showing the positional relationship between a central ECU and a DC/DC converter. FIG. 2 is a block diagram schematically showing a power supply system.

Hereinafter, exemplary embodiments will be described in detail with reference to the drawings.

FIG. 1 shows the configuration of a power supply system of a mobile body equipped with a power supply system according to an embodiment. In this embodiment, the moving object is a vehicle 1 of an automobile. This vehicle 1 is a five-door vehicle that includes four side doors and one back door. Vehicle 1 is a vehicle capable of manual driving in which the vehicle travels in response to the driver's operation of the accelerator, etc., assisted driving in which the vehicle travels by assisting the driver's operations, and automatic driving in which the vehicle travels without the driver's operation. be. In the following description, the moving body may be simply expressed as a vehicle 1. In addition, "front", "rear", "right", and "left" refer to "front of vehicle 1", "rear of vehicle 1", "right of vehicle 1", and "left of vehicle 1". means.

As shown in FIG. 1, the vehicle 1 includes a low-voltage battery 2, a high-voltage battery 3 capable of supplying power with a higher voltage than the low-voltage battery 2, and first to first batteries capable of transmitting control signals to devices included in the vehicle 1. It includes three sub-ECUs 11 to 13 (Electric Control Units), and a central ECU 20 that is communicatively connected to the first to third sub-ECUs 11 to 13, respectively, and centrally controls the first to third sub-ECUs 11 to 13. The vehicle 1 also includes a DC/DC converter 40 (hereinafter referred to as converter 40) connected to the low voltage battery 2 and high voltage battery 3 via electric wires, and a fuse box 30 connected to the low voltage battery 2 via electric wires. . Fuse box 30 is connected to the downstream side of converter 40 via electric wires.

The first to third sub-ECUs 11 to 13 are each connected to a fuse box 30 via electric wires. Central ECU 20 is connected to the downstream side of converter 40 without going through fuse box 30. Note that the number of sub-ECUs may be less than three or four or more.

The number of electric wires is increased or decreased depending on the number of sub-ECUs, the number of batteries, the number of fuse boxes 30, and the number of converters 40. Each electric wire may be any electric wire capable of supplying electric power, and may be constituted by a wire harness, for example.

The low voltage battery 2 is a 12V battery in this embodiment. The low voltage battery 2 is placed at the front of the engine room (motor room in the case of an electric vehicle). The low voltage battery 2 is composed of, for example, a lead acid battery.

The high voltage battery 3 is a 48V battery in this embodiment. The high voltage battery 3 is placed below the seat. The high voltage battery 3 is made up of, for example, a lithium ion battery.

An ISG 50 (Integrated Starter Generator) is connected to the high voltage battery 3. Electric power from the high voltage battery 3 is supplied to the ISG 50 without being reduced in voltage.

The first to third sub-ECUs 11 to 13 are each computer hardware, and specifically each has a processor having a CPU, a memory in which a plurality of modules are stored, and the like. The first to third sub-ECUs 11 to 13 are each communicably connected to a device mounted on the vehicle 1. The first to third sub-ECUs 11 to 13 output control signals to each device based on control signals from the central ECU 20. A device is a concept that includes sensors and actuators, and includes, for example, electric mirrors, power windows, power seats, brake lights, and the like. The first to third sub-ECUs 11 to 13 are terminal ECUs for controlling each device, and their power consumption is approximately several watts.

As shown in FIGS. 1 and 2, the first sub-ECU 11 is provided at a position below the left front hinge pillar. The first sub-ECU 11 controls, for example, electric mirrors and power windows. The second sub-ECU 12 is provided at the center console. The second sub-ECU 12 controls, for example, a power seat. The third sub-ECU 13 is provided at a position on the left rear side of the vehicle 1. The third sub-ECU 13 controls, for example, brake lamps.

As shown in FIGS. 2 and 3, the central ECU 20 is disposed on the rear side of the dash panel 4 and directly below the instrument panel 5 (hereinafter referred to as the instrument panel 5). The central ECU 20 is arranged at the center in the vehicle width direction. Thereby, the central ECU 20 can be protected as much as possible even in the event of a frontal or side collision of the vehicle 1.

As shown in FIG. 4, the central ECU 20 includes a microcontrol unit (hereinafter referred to as MCU 21) and a communication section 22 for communicating with the first to third sub-ECUs 11 to 13.

The MCU 21 generates control signals for controlling each device and transmits them to the first to third sub-ECUs 11 to 13. The control signals that the central ECU 20 outputs to the first to third sub-ECUs 11 to 13 indicate, for example, the operation target of each device, and the control amount for actually operating each device is determined by the first to third sub-ECUs 11 to 13. Generated by the ECUs 11-13. When there is a sub-ECU that does not operate, the MCU 21 directly controls devices controlled by the sub-ECU in place of the sub-ECU.

The communication unit 22 transmits the control signal generated by the MCU 21 to the first to third sub-ECUs 11 to 13, and acquires information about the operating state from the first to third sub-ECUs 11 to 13. The operating states of the first to third sub-ECUs 11 to 13 include the energization states of the first to third sub-ECUs 11 to 13. The energization state of the first to third sub-ECUs 11 to 13 includes, for example, an overcurrent due to an abnormality in the electric wire, a short circuit within the ECU, and the like. As a communication method between the communication unit 22 and the first to third sub-ECUs 11 to 13, CAN (Controller Area Network), CAN-FD (CAN with Flexible Datarate), Ethernet (registered trademark), etc. can be used. Although the communication method between the communication unit 22 and the first to third sub-ECUs 11 to 13 is a wired method, it may be a wireless method, or it may be possible to use a wireless method for some parts and a wired method for the others. good. The communication unit 22 is an example of a module stored in the memory of the central ECU 20.

The central ECU 20 needs to have a high calculation function in order to centrally generate control signals to each of the sub-ECUs 11 to 13. The power consumption of the central ECU 20 is considerably larger than that of each of the sub-ECUs 11 to 13, and is approximately several tens of watts.

The fuse box 30 functions as a relay device that relays a power path between the low voltage battery 2 and the first to third sub-ECUs 11 to 13. Specifically, the fuse box 30 has a function of dividing the power supplied from the battery 2 to the first to third sub-ECUs 11 to 13 and distributing the power to the first to third sub-ECUs 11 to 13. The fuse box 30 is placed in front of the low voltage battery 2, as shown in FIGS. 1 and 2.

As shown in FIG. 4, the fuse box 30 has mechanical fuses 31 to 33 as a plurality of switch systems that respectively control on/off of power supply from the low voltage battery 2 to the first to third sub-ECUs 11 to 13. A first mechanical fuse 31 is provided between the low voltage battery 2 and the first sub-ECU 11, a second mechanical fuse 32 is provided between the low voltage battery 2 and the second sub-ECU 12, and a second mechanical fuse 32 is provided between the low voltage battery 2 and the third sub-ECU 12. A third mechanical fuse 33 is provided between the sub-ECU 13 and the sub-ECU 13 . Each of the mechanical fuses 31 to 33 is disconnected when an overcurrent flows through the electric wire, and prevents each of the sub ECUs 11 to 13 from malfunctioning due to the overcurrent.

Converter 40 converts the power supplied from high voltage battery 3 to the same voltage as low voltage battery 2 (for example, 12V). As shown in FIGS. 2 and 3, the converter 40 is disposed at a position closer to the rear side of the engine room and at approximately the same height as the central ECU 20. More specifically, converter 40 is arranged adjacent to center ECU 20 on the front side of center ECU 20 with dash panel 4 in between. That is, converter 40 is arranged near central ECU 20. Thereby, the electric wire connecting central ECU 20 and converter 40 can be considerably shortened.

As shown in FIG. 4, the converter 40 includes two converter circuits 41 and 42, two controllers 43 and 44 that control each converter circuit 41 and 42, and a CPU 45 that outputs a control signal to each controller 43 and 44. has. Each converter circuit 41, 42 is controlled by each controller 43, 44 based on a control signal from CPU 45. Each converter circuit 41, 42 reduces the voltage of power supplied from the high-voltage battery 3 (for example, 48V) to a voltage comparable to that of the low-voltage battery 2 (for example, 12V).

Converter 40 has a communication IC 46 for communicating with central ECU 20. Communication IC 46 receives a signal sent from communication IC 22 of central ECU 20 and sends it to CPU 45 . The communication method between the communication IC 46 of the converter 40 and the communication IC 22 of the central ECU 20 may be, for example, CAN or CAN-FD.

As shown in FIG. 4, converter 40 has a plurality of switch systems that respectively control on/off of power supply from high voltage battery 3 to central ECU 20. Each switch system is comprised of semiconductor fuses 47. Converter 40 also includes a semiconductor fuse 47 that controls on/off of power supply from high-voltage battery 3 to central ECU 20 .

The on/off state of the semiconductor fuse 47 is controlled by the CPU 45. When the CPU 45 receives a control signal regarding the on/off of the semiconductor fuse 47 from the central ECU 20 via the communication IC 46, the CPU 45 switches the on/off state of the semiconductor fuse 47. That is, the energization state between the high voltage battery 3 and the central ECU 20 is controlled by the central ECU 20 itself.

The converter 40 is configured to be able to communicate with the first to third sub-ECUs 11 to 13. As will be described in detail later, the converter 40 allows the central ECU 20 to transmit the self-shutoff function to the first to third sub-ECUs 11 to 13 when the central ECU 20 cuts off power supply by itself (when executing the self-shutoff function described below). Notify that it will be executed.

As described above, central ECU 20 is connected to converter 40 without going through fuse box 30. For this reason, a function is required to cut off the power supply when an abnormality in energization occurs, such as an overcurrent to the wire or an internal short circuit. Therefore, in the present embodiment, when the central ECU 20 detects that an energization abnormality has occurred, the central ECU 20 outputs a control signal to the converter 40 to turn off the power supply from the low-voltage and high-voltage batteries 2 and 3 to the central ECU 20. Execute self-shutdown function. This will be explained with reference to FIG. 4.

First, assume that a short circuit occurs inside the central ECU 20. MCU 21 of central ECU 20 notifies CPU 45 of converter 40 to execute the self-shutdown function. The CPU 45, which has received the notification from the central ECU 20, notifies the first to third sub-ECUs 11 to 13 via the communication IC 46 that the central ECU 20 will execute the self-shutdown function. After notifying each sub-ECU 11 to 13, the CPU 45 turns off the semiconductor fuse 47. As a result of the above, the power supply to the central ECU 20 is cut off.

On the other hand, the first to third sub-ECUs 11 to 13 that have received the notification from the CPU 45 control each device according to the scene (situation) of the vehicle 1 and the type of device connected for communication, without using the central ECU 20. do.

In this manner, when the central ECU 20 executes the self-shutdown function, the converter 40 notifies the first to third sub-ECUs 11 to 13. This allows the first to third sub-ECUs 11 to 13 to continue controlling each device, so that even if the vehicle 1 is running, it can continue to drive. Furthermore, the converter 240 and the central ECU 20 are arranged adjacent to each other with the dash panel 4 in between. Therefore, communication between converter 240 and central ECU 20 can be performed in a fairly short time. Thereby, when central ECU 20 determines that it is necessary to execute the self-shutoff function, converter 240 can quickly turn off semiconductor fuse 47.

Therefore, although the power supply system according to the present embodiment has a plurality of ECUs (first to third sub-ECUs 11 to 13 and central ECU 20) with significantly different power consumption, the first to third sub-ECUs have relatively lower power consumption. While the ECUs 11 to 13 are electrically connected to the fuse box 30, the central ECU 20, which consumes a large amount of power, is electrically connected to the downstream side of the converter 40 without going through the fuse box 30. Thereby, there is no need to route large-diameter electric wires throughout the vehicle 1. As a result, the effects of voltage drop and noise are reduced, so it is possible to create a configuration in which the ECUs are less likely to adversely affect each other.

Further, in this embodiment, power is supplied to the central ECU 20 through a power supply path different from that to each of the sub-ECUs 11 to 13. Therefore, even if the electric wire between the low voltage battery 2 and the fuse box 30 is disconnected, power is supplied to the central ECU 20. Therefore, by having the central ECU 20 control each device instead of each of the sub-ECUs 11 to 13, it is possible to suppress the influence of a power failure on the operation of the mobile body. Furthermore, even if the wire between the high voltage battery 3 and the converter 40 is disconnected, the central ECU 20 can receive power from the low voltage battery 2 via the converter 40. Therefore, the operating state of the central ECU 20 can be maintained, and the influence on the operation of the vehicle 1 can be suppressed.

Further, in this embodiment, the converter 40 includes a semiconductor fuse 47 that controls on/off of power supply from the low-voltage and high-voltage batteries 2 and 3 to the central ECU 20, and the central ECU 20 can communicate with the converter 40. At the same time, when an abnormality is detected in the converter 40, a control signal is output to the converter 40 to turn off the semiconductor fuse 47 and turn off the power supply to the converter 40 from the low-voltage and high-voltage batteries 2 and 3. Thereby, the central ECU 20 outputs a control signal to the converter 40 to cut off the power supply when an energization abnormality occurs in the central ECU 20, so that the power supply can be cut off quickly. Thereby, failure of the central EU 20 can be appropriately suppressed.

In particular, in this embodiment, when central ECU 20 executes the self-shutdown function, CPU 45 of converter 40 notifies each sub-ECU 11 to 13. This allows the first to third sub-ECUs 11 to 13 to continue controlling each device. Further, since the CPU 45 and the first to third sub-ECUs 11 to 13 can communicate via the communication IC 46, it is also possible to send control signals from the CPU 45 to each of the sub-ECUs 11 to 13. Thereby, it is also possible to move the vehicle 1 to a safe area such as the shoulder of the road using a control signal from the CPU 45.

Furthermore, in this embodiment, the central ECU 20 is located at the rear of the vehicle relative to the dash panel 4 and directly below the instrument panel 5, and the converter 40 is located at a position closer to the rear of the vehicle in the engine room and located at the rear of the vehicle than the dash panel 4 and directly below the instrument panel 5. are located at approximately the same height. This allows the electric wire between central ECU 20 and converter 40 to be considerably shortened. Therefore, the influence of voltage drop and noise on the electric wire is reduced, and power failure due to disconnection can also be suppressed, and the influence on the operation of the vehicle 1 can be suppressed.

(Other embodiments)
The technology disclosed herein is not limited to the embodiments described above, and may be substituted without departing from the spirit of the claims.

For example, in the embodiment described above, when central ECU 20 executes the self-shutdown function, CPU 45 of converter 40 notifies each sub-ECU 11 to 13. However, the present invention is not limited to this, and the central ECU 20 may notify each of the sub-ECUs 11 to 13 that the cutoff function will be executed. Furthermore, when the central ECU 20 executes the self-shutdown function, the CPU 45 of the converter 40 not only notifies each sub ECU 11 to 13 but also outputs a control signal to each sub ECU 11 to 13 on behalf of the central ECU 20. It's okay.

Further, in the above-described embodiment, the moving object is an automobile, but the object is not limited to this, and a heavy machinery vehicle or the like may be used as the object.

The above-described embodiments are merely illustrative and should not be construed as limiting the scope of the present disclosure. The scope of the present disclosure is defined by the claims, and all modifications and changes that come within the range of equivalents of the claims are intended to be within the scope of the present disclosure.

The technology disclosed herein is useful in a power supply system for a mobile body to improve electricity consumption in the mobile body.

1 Vehicle (mobile object)
2 First battery 3 Second battery 4 Dash panel 5 Instrument panel 11 First sub ECU (sub computing unit)
12 2nd sub-ECU (sub-computation unit)
13 Third sub-ECU (sub-computation unit)
20 Central ECU (central processing unit)
30 Fuse box 40 DCDC converter 47 Semiconductor fuse (switch system)

Claims (3)

A power supply system for a mobile body,
a first battery;
a second battery capable of supplying power at a higher voltage than the first battery;
a DC/DC converter that is electrically connected to the first battery and the second battery and that steps down the voltage of the power supplied from the second battery to the voltage of the first battery;
a fuse box electrically connected to the first battery and downstream of the DCDC converter;
a plurality of sub-processing units capable of transmitting control signals to devices possessed by the mobile body;
a central processing unit that is communicatively connected to each of the plurality of sub-processing units and centrally controls the plurality of sub-processing units;
The sub-processing devices are each electrically connected to the fuse box,
The central processing unit is electrically connected to the DCDC converter without going through the fuse box,
The DCDC converter has a switch system that respectively controls on and off of power supply from the first and second batteries to the central processing unit,
The central processing unit is capable of communicating with the DCDC converter, and when detecting an abnormality in itself, turns off the switch system and turns off power supply to itself from the first and second batteries. A power supply system for a mobile body, characterized in that a control signal is output to the DC/DC converter so as to perform the following steps . The mobile body power supply system according to claim 1 ,
A power supply system for a mobile body, wherein the DC/DC converter is placed near the central processing unit. A power supply system for a mobile body,
a first battery;
a second battery capable of supplying power at a higher voltage than the first battery;
a DC/DC converter that is electrically connected to the first battery and the second battery and that steps down the voltage of the power supplied from the second battery to the voltage of the first battery;
a fuse box electrically connected to the first battery and downstream of the DCDC converter;
a plurality of sub-processing units capable of transmitting control signals to devices possessed by the mobile body;
a central processing unit that is communicatively connected to each of the plurality of sub-processing units and centrally controls the plurality of sub-processing units;
The sub-processing devices are each electrically connected to the fuse box,
The central processing unit is electrically connected to the DCDC converter without going through the fuse box,
The DCDC converter is located near the central processing unit,
The central processing unit is located at the rear of the vehicle than the dash panel and directly below the instrument panel,
A power supply system for a mobile object, wherein the DC/DC converter is disposed at a position near the rear of the vehicle in an engine room or a motor room and at approximately the same height as the central processing unit.

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