Onboard device, program, and information processing method

Abstract

This onboard device operates by an internal voltage output from a power supply device mounted on a vehicle, the onboard device comprising: a bidirectional circuit that is provided with an external terminal to which a vehicle external power device is connected from outside of the vehicle and that has a transformation function; and a control unit for controlling the bidirectional circuit. The control unit determines whether the power supply device requires charging when the vehicle external power device is connected to the external terminal, charges the power supply device by acquiring external voltage from the vehicle external power device via the bidirectional circuit if determined that the power supply device requires charging, and charges the vehicle external power device by outputting the internal voltage from the power supply device via the bidirectional circuit and executes transformation processing in the bidirectional circuit in accordance with the internal voltage and a voltage input to and output from the vehicle external power device if determined that the power supply device does not require charging.

Description

Vehicle-mounted device, program, and information processing method

[0001] The present technology relates to a vehicle-mounted device, a program, and an information processing method. This application claims priority based on Japanese Application No. 2024-231050 filed on December 26, 2024, and incorporates all the descriptions described in the above Japanese application.

[0002] A vehicle is equipped with a power supply control device (see, for example, Patent Document 1) that controls power supply from a battery to a load. In the power supply control device described in Patent Document 1, a downstream semiconductor fuse is provided in the current path of the current flowing from the battery to the load, and the power supply from the battery to the load is controlled by switching the downstream semiconductor fuse on or off.

[0003] The downstream semiconductor fuse has a control terminal. For example, when the downstream semiconductor fuse is a FET (Field Effect Transistor), the control terminal is the gate. The resistance value between both ends of the downstream semiconductor fuse changes according to the voltage of the control terminal. By adjusting the voltage of the control terminal, the resistance value between both ends of the downstream semiconductor fuse is adjusted to a sufficiently small value, and the downstream semiconductor fuse is switched on. By adjusting the voltage of the control terminal, the resistance value between both ends of the downstream semiconductor fuse is adjusted to a sufficiently large value, and the downstream semiconductor fuse is switched off.

[0004] Japanese Patent Application Laid-Open No. 2013-143905

[0005] An in-vehicle device according to one embodiment of the present disclosure is an in-vehicle device that operates by an internal voltage which is a voltage output from a power supply device mounted on a vehicle, and is provided with an external terminal to which an external power supply device is connected from outside the vehicle, and comprises a bidirectional circuit having a voltage transformation function and a control unit that controls the bidirectional circuit, wherein when the external power supply device is connected to the external terminal, the control unit determines whether or not the power supply device needs to be charged, and if it determines that the power supply device needs to be charged, it charges the power supply device by acquiring an external voltage from the external power supply device via the bidirectional circuit, and if it determines that the power supply device does not need to be charged, it charges the external power supply device by outputting the internal voltage from the power supply device via the bidirectional circuit, and the bidirectional circuit performs voltage transformation processing according to the internal voltage and the voltages input and output in the external power supply device.

[0006] This is a schematic diagram illustrating the configuration of an in-vehicle system including an in-vehicle device according to Embodiment 1. This is a block diagram illustrating the internal configuration of the in-vehicle device. This is a flowchart illustrating the processing of the control unit of the in-vehicle device. This is a flowchart illustrating the processing of the control unit of the in-vehicle device according to Embodiment 2 (selection screen). This is an explanatory diagram illustrating the selection screen.

[0007] [Problems to be Solved by This Disclosure] In the power supply control device described in Patent Document 1, when an external power device is connected to an external terminal, the device determines whether or not to charge the power supply device, and in order to perform charging according to that determination, it does not take into consideration that a transformer process is performed in a bidirectional circuit according to the internal voltage of the power supply device and the voltages input and output to and from the external power device.

[0008] This disclosure is made in view of the above circumstances and aims to provide an in-vehicle device, etc., that can perform voltage transformation processing in a bidirectional circuit according to the internal voltage of the power supply device and the voltages input and output at the external power supply device when performing processing related to charging with an external power supply device.

[0009] [Effects of this Disclosure] According to one aspect of this disclosure, it is possible to provide an in-vehicle device, etc., that performs voltage transformation processing in a bidirectional circuit according to the internal voltage of the power supply device and the voltages input and output at the external power supply device when performing processing related to charging with an external power supply device.

[0010] [Description of Embodiments of the Disclosure] First, embodiments of the Disclosure will be listed and described. At least some of the embodiments described below may be combined in any way.

[0011] (1) An in-vehicle device according to one aspect of the present disclosure is an in-vehicle device that operates by an internal voltage which is a voltage output from a power supply device mounted on a vehicle, and is provided with an external terminal to which an external power supply device is connected from outside the vehicle, and comprises a bidirectional circuit having a voltage transformation function and a control unit that controls the bidirectional circuit, wherein when the external power supply device is connected to the external terminal, the control unit determines whether or not the power supply device needs to be charged, and if it determines that the power supply device needs to be charged, it charges the power supply device by acquiring an external voltage from the external power supply device via the bidirectional circuit, and if it determines that the power supply device does not need to be charged, it charges the external power supply device by outputting the internal voltage from the power supply device via the bidirectional circuit, and the bidirectional circuit performs voltage transformation processing according to the internal voltage and the voltages input and output in the external power supply device.

[0012] In this embodiment, an on-board device is connected to a power line extending from a power supply device such as a Li-ion battery mounted on the vehicle, and the on-board device is driven by the power supplied from the power supply device. The on-board device may also have a DC-DC converter connected as the main unit, which transforms the voltage from an alternator or a secondary battery such as a lithium battery. In this case, the power supply device such as a Li-ion battery is considered an auxiliary unit, and the on-board device is connected to both the main unit (DC-DC converter) and the auxiliary unit (power supply device such as a Li-ion battery). The auxiliary power supply device is the device that is charged using an external voltage from an external power supply device. The on-board device may use the internal voltage from the main unit (DC-DC converter) as the driving voltage when the vehicle is running, and the internal voltage from the auxiliary unit (power supply device such as a Li-ion battery) as the driving voltage when the vehicle is stopped. Furthermore, the on-board device may be connected to on-board loads such as door mirrors, seat movement devices, interior lamps (actuators), or various sensors, and the on-board device may distribute power from the power supply to these on-board loads. These on-board loads and the on-board device are connected by distribution paths that are branched and connected in parallel within the on-board device, and the on-board device may function as a power control device that controls the starting or stopping of each of these on-board loads. The on-board device includes a bidirectional circuit that corresponds to the internal voltage (supplied power) applied from the power supply device mounted on the vehicle, and also has an external terminal to which an external power supply device is connected. The on-board device and the external power supply device are energetically connected via the bidirectional circuit, and the external power supply device may be a charging execution device that charges the vehicle's power supply device, or a charging target device that is charged from the vehicle's power supply device or main unit (DC / DC converter). When the external power supply device is a charging execution device, the charging execution device may be, for example, the battery of another vehicle (another car) or a portable battery. When an external power device is the device to be charged, that device is, for example, the battery of another vehicle that has experienced a battery failure. In this way, the bidirectional circuit is configured so that bidirectional charging occurs, that is, so that charging current flows in both directions, with charging occurring from the external power device to the vehicle's power supply and from the vehicle's power supply to the external power device.The control unit of the in-vehicle device, for example, based on a change in the potential of the pins of the external terminal, detects that an external power device has been connected to the external terminal and determines whether or not to charge the power supply unit. If the control unit of the in-vehicle device determines that charging the power supply unit is necessary, it charges the power supply unit by acquiring the external voltage from the external power device via a bidirectional circuit. In this case, the power supply specifications of the control unit are configured to be driven by the external voltage applied from the external power device. That is, the external voltage can be either the same voltage value as the internal voltage from the power supply unit (e.g., 48V) or a lower voltage value (e.g., 12V), and the microcontroller constituting the control unit is configured to drive regardless of the voltage value (48V or 12V). In this case, the microcontroller may be equipped with a regulator or a DC-DC converter to transform the input voltage into the microcontroller's drive voltage. If the control unit of the in-vehicle device determines that charging the power supply unit is unnecessary, it charges the external power device by outputting the internal voltage from the power supply unit via a bidirectional circuit. In this way, when an external power device is connected to the external terminal of the bidirectional circuit, the control unit of the on-board device can perform charging from the external power device (acquire external voltage) or charge the external power device (output internal voltage) via the bidirectional circuit, thereby enabling appropriate power supply control to the external power device. Furthermore, the control unit of the on-board device performs voltage transformation processing using the transformer function of the bidirectional circuit according to the internal voltage from the power supply and the voltages input and output at the external power device. Therefore, even if the output voltage (battery voltage) differs between the vehicle's (own vehicle's) power supply and an external power device such as the power supply of another vehicle, they can charge each other, meaning they can help each other. In this way, by controlling the transformer function of the bidirectional circuit, the control unit of the on-board device can connect to various external power devices regardless of the output voltage (battery voltage), thus eliminating the need to update power receiving cables (booster cables or battery cables, etc.) and jump starter equipment for connecting to external power devices, and improving the versatility of the on-board device.

[0013] (2) In an in-vehicle device according to one aspect of the present disclosure, the control unit acquires the voltage value of the voltage output from the power supply device, determines that charging of the power supply device is necessary if the acquired voltage value of the power supply device is less than a predetermined charging threshold, and determines that charging of the power supply device is unnecessary if it is equal to or greater than the charging threshold.

[0014] In this embodiment, the control unit of the in-vehicle device, in determining whether or not charging the power supply unit is necessary, that is, whether or not a power failure has occurred in the power supply unit due to a dead battery or the like, acquires the voltage value of the internal voltage output from the power supply unit at the present time and compares the acquired voltage value with a predetermined charging threshold. For example, if the rated voltage value of the internal voltage output from the power supply unit, that is, the voltage value for which operation is guaranteed, is 48V, this rated voltage value may be set as the charging threshold and stored in the memory unit of the microcontroller that constitutes the control unit. Alternatively, the charging threshold may be set based on a predetermined coefficient, such as 99% of the rated voltage value. If the acquired voltage value is less than the predetermined charging threshold, the control unit of the in-vehicle device determines that charging of the power supply unit is necessary, that is, that a power failure has occurred in the power supply unit due to a dead battery or the like. If the acquired voltage value is equal to or greater than the predetermined charging threshold, the control unit of the in-vehicle device determines that charging of the power supply unit is unnecessary, that is, that the power supply unit is operating normally and an internal voltage equal to the rated voltage value is being output. Therefore, by determining whether charging is necessary based on the charge state (SOC) of the power supply unit, the reliability of this determination can be ensured. The determination of whether charging is necessary is triggered when an external power supply unit is connected to the external terminal, and when the determination is made, the on-board unit and the external power supply unit are connected via the external terminal. Therefore, based on the determination result, charging from the external power supply unit or charging (rescue) to the external power supply unit can be performed efficiently.

[0015] (3) An in-vehicle device according to one aspect of the present disclosure includes an external power device which includes a first external power device which is driven at the same first voltage value as the internal voltage and a second external power device which is driven at a second voltage value lower than the internal voltage, wherein when the control unit determines that charging the power supply is unnecessary, it obtains the voltage value of the voltage applied from the external power device, and determines whether the external power device is the first external power device or the second external power device based on the obtained voltage value of the external power device, and if it determines that it is the first external power device, it outputs the internal voltage from the power supply to the first external power device without transforming it, and if it determines that it is the second external power device, it outputs the internal voltage which has been stepped down to the second voltage value by the bidirectional circuit to the second external power device.

[0016] In this embodiment, the external power unit includes a first external power unit driven at a first voltage value (e.g., 48V) the same as the internal voltage, and a second external power unit driven at a second voltage value (e.g., 12V) lower than the internal voltage. In other words, it is assumed that the driving voltage values ​​may differ for each external power unit. When the vehicle's power supply and the external power unit are connected in a way that allows power to flow through a bidirectional circuit, the positive terminals (+) of the vehicle's power supply and the external power unit are connected to each other. At this time, the voltage value of the voltage applied (output) from the external power unit is detected by a voltage detection unit, which is configured in, for example, a voltage sensor included in the bidirectional circuit or a monitor circuit disposed between the bidirectional circuit and an external terminal. The control unit and the voltage detection unit are connected in a way that allows communication, and the control unit of the in-vehicle device acquires the voltage value detected by the voltage detection unit (the voltage value output by the external power unit). When the control unit of the in-vehicle device determines that charging the power supply unit is unnecessary, it will charge an external power supply unit (another vehicle) that has experienced battery drain or other issues. At this time, based on the acquired voltage value of the external power supply unit, it determines whether the external power supply unit is the first external power supply unit (48V) or the second external power supply unit (12V). In other words, if battery drain or other issues occur in the first external power supply unit and the second external power supply unit, the voltage values ​​output from these two units will be different. Therefore, the control unit can efficiently determine whether the external power supply unit is the first external power supply unit (48V) or the second external power supply unit (12V) based on the acquired voltage value of the external power supply unit. Furthermore, if the control unit determines that the external power device is the first external power device (driven at a first voltage value (48V) which is the same as the internal voltage), it can output the internal voltage from the power supply unit to the first external power device without transforming the internal voltage, thereby charging the first external power device. If the control unit determines that the external power device is the second external power device (driven at a second voltage value (12V) which is lower than the internal voltage), it can output the internal voltage, which has been stepped down to the second voltage value using the transformation function of the bidirectional circuit, to the second external power device, thereby charging the second external power device.Therefore, even if the drive voltage (battery voltage) differs between the vehicle's (own vehicle's) power supply unit and an external power supply unit, such as the power supply unit of another vehicle, the external power supply unit can be charged and rescued.

[0017] (4) In an in-vehicle device according to one aspect of the present disclosure, the control unit determines that the external power device is the first external power device if the acquired voltage value of the external power device is less than or equal to a predetermined determination threshold, and determines that the external power device is the second external power device if the acquired voltage value of the external power device exceeds the determination threshold.

[0018] In this embodiment, the control unit of the in-vehicle device determines whether the external power device is a first external power device (48V) or a second external power device (12V) by comparing the acquired voltage value of the external power device with a determination threshold (for example, 5V) pre-stored in the memory of the microcontroller. If the first external power device is, for example, the battery of another vehicle that uses 48V as a power source, it is assumed that the other vehicle is an EV (Electric Vehicle), HV (Hybrid Vehicle), or PHEV (Plug-in Hybrid Electric Vehicle), and is equipped with a high-voltage battery such as a lithium secondary battery. In this case, if the SOC of the high-voltage battery such as the lithium secondary battery falls below a predetermined value and power is lost, it is assumed that a relatively low voltage, such as 0V to 5V, will be output as the voltage output specification to the outside. In contrast, if the second external power device is, for example, the battery of another vehicle that uses 12V as its power source, it is assumed that this other vehicle is a gasoline vehicle equipped with a lead-acid battery (fully charged at 12.72V) with a rated output of, for example, 12.4V or higher. In this case, if a battery failure occurs in the lead-acid battery (which operates normally at 12.4V or higher), it is assumed that the voltage output from the dead lead-acid battery will be 12.3V or lower and exceed 5V. Thus, for each external power device (other vehicle), the control unit of the on-board device can efficiently determine, according to the voltage output specifications or characteristics when a battery failure occurs, whether the external power device (other vehicle) is a first external power device (other vehicle: 48V vehicle) with the same battery voltage as the own vehicle (48V vehicle), or a second external power device (other vehicle: 12V vehicle) with a lower battery voltage than the own vehicle.

[0019] (5) An in-vehicle device according to one aspect of the present disclosure includes an external power device which includes a first external power device which is driven at the same first voltage value as the internal voltage and a second external power device which is driven at a second voltage value lower than the internal voltage, wherein when the control unit determines that charging the power supply is unnecessary, it outputs a selection screen to the external power device for selecting whether or not to reduce the internal voltage by the bidirectional circuit when outputting the internal voltage from the power supply via the bidirectional circuit, and acquires the selection received on the selection screen, and if the acquired selection indicates that reduction is necessary, it outputs the internal voltage reduced to the second voltage value by the bidirectional circuit to the external power device, and if the acquired selection indicates that reduction is unnecessary, it outputs the internal voltage from the power supply to the external power device without transforming it.

[0020] In this embodiment, when the control unit of the in-vehicle device determines that charging the power supply unit is unnecessary, it charges an external power unit (another vehicle) that has experienced battery drain or other issues. In this case, the external power unit (another vehicle) is assumed to be either a first external power unit (48V vehicle) driven at a first voltage value (48V) the same as the internal voltage, or a second external power unit (12V vehicle) driven at a second voltage value (12V) lower than the internal voltage. The control unit then outputs a selection screen for selecting whether or not to step down the internal voltage using the transformer function of the bidirectional circuit to an information terminal such as a smartphone used by the vehicle operator, for example, via an external communication device with wireless functionality. Alternatively, the control unit may output the selection screen to an HMI (Human Machine Interface) device such as a display. The selection entered by the operator is received on the selection screen, and the control unit acquires the selection (selection result). The control unit then performs the transformer process using the bidirectional circuit according to the acquired selection result. In other words, if the selection indicates that voltage reduction is not required, the control unit outputs the internal voltage from the power supply unit to the external power unit (first external power unit) without transforming it. If the selection indicates that voltage reduction is required, the control unit outputs the internal voltage, reduced to a second voltage value using the transformation function of the bidirectional circuit, to the external power unit (second external power unit). By requesting the vehicle operator to select whether or not to reduce the internal voltage using the transformation function of the bidirectional circuit using the selection screen, appropriate charging can be performed according to the battery voltage of the external power unit (other vehicle) connected to the external terminal. When outputting the selection screen, the control unit may include a determination result on the selection screen, based on the voltage value output from the external power unit (other vehicle), to determine whether it is the first external power unit or the second external power unit. By outputting a selection screen that includes this determination result, the vehicle operator's selection can be efficiently supported.

[0021] (6) An in-vehicle device according to one aspect of the present disclosure includes an external power device which includes a first external power device which outputs the same first voltage value as the internal voltage and a second external power device which outputs a second voltage value lower than the internal voltage, wherein when the control unit determines that it is necessary to charge the power supply device, it obtains the voltage value of the external voltage from the external power device, and determines whether the external power device is the first external power device or the second external power device based on the obtained voltage value of the external voltage, and if it determines that it is the first external power device, it outputs the external voltage from the external power device to the power supply device without transforming it, and if it determines that it is the second external power device, it outputs the external voltage which has been boosted to the first voltage value by the bidirectional circuit to the power supply device.

[0022] In this embodiment, when the control unit determines that the power supply unit needs to be charged, it acquires the voltage value of the external voltage from the external power supply unit detected by the voltage detection unit. The external power supply unit is assumed to consist of a first external power supply unit (48V) that is driven at a first voltage value (48V) the same as the internal voltage, and a second external power supply unit (12V) that is driven at a second voltage value (12V) lower than the internal voltage. In this case, the voltage value of the external voltage from the first external power supply unit is the first voltage value, the same as the internal voltage, and the voltage value of the external voltage from the second external power supply unit is the second voltage value, which is lower than the internal voltage. Based on the voltage value acquired from the voltage detection unit, the control unit can efficiently determine whether the external power supply unit connected to the external terminal is the first external power supply unit or the second external power supply unit. If the control unit determines that it is the first external power supply unit, it outputs the external voltage from the external power supply unit to the power supply unit without transforming the voltage, thereby charging the power supply unit. If the control unit determines that it is a second external power device, it uses the transformer function of the bidirectional circuit to boost the external voltage to a first voltage value and outputs it to the power supply unit, thereby charging the power supply unit. Therefore, even if the drive voltage (battery voltage) differs between the vehicle's (own vehicle's) power supply unit and an external power device such as another vehicle's power supply unit, the vehicle's (own vehicle's) battery can be charged from the external power supply unit, resolving battery drain in the vehicle's (own vehicle's) power supply unit.

[0023] (7) An in-vehicle device according to one aspect of the present disclosure, wherein the bidirectional circuit is a bidirectional DC / DC converter, and the control unit derives a voltage transformation ratio in the bidirectional circuit according to the ratio of the external voltage to the internal voltage, and controls the bidirectional circuit with the derived voltage transformation ratio.

[0024] In this embodiment, the bidirectional circuit is a bidirectional DC / DC converter, which may include, for example, a coil and semiconductor switches such as FETs, and may be configured in a forward, bridge, or flyback type using a step-up / step-down chopper circuit. When the control unit performs charging from the power supply unit to the external power unit, or from the external power unit to the power supply unit, it derives a transformation ratio (step-up / step-down ratio) of the external voltage or internal voltage according to the ratio of the external voltage from the external power unit, i.e., the battery voltage which is the driving voltage in the external power unit, and the internal voltage of the power supply unit (the driving voltage of the vehicle). Based on the derived transformation ratio, the control unit generates, for example, a PWM signal and controls the transformation function of the bidirectional circuit by outputting the PWM signal to the gate terminal of the FET of the bidirectional DC / DC converter. When the control unit charges the external power supply unit from the power supply unit, if the power supply unit is 48V and the external power supply unit is 12V, the control unit derives the transformation ratio (boost-down ratio) by setting the step-down ratio to 4 (stepping down to 1 / 4). If the power supply unit is 48V and the external power supply unit is 48V, the control unit may derive the transformation ratio (boost-down ratio) without transforming the voltage, i.e., by setting the transformation ratio to 1. When the control unit charges the external power supply unit from the external power supply unit to the power supply unit, if the power supply unit is 48V and the external power supply unit is 12V, the control unit derives the transformation ratio (boost-down ratio) by setting the step-up ratio to 4 (stepping up to 4 times). If the power supply unit is 48V and the external power supply unit is 48V, the control unit may derive the transformation ratio (boost-down ratio) without transforming the voltage, i.e., by setting the transformation ratio to 1. By deriving the voltage transformation ratio (step-up / step-down ratio) in this way, even if the output voltage (battery voltage) differs between the vehicle's (own vehicle's) power supply unit and an external power supply unit, such as another vehicle's power supply unit, they can charge each other, meaning they can help each other out.

[0025] (8) An in-vehicle device according to one aspect of the present disclosure has an internal voltage value of 48V and an external voltage value of 12V, 24V, or 48V.

[0026] In this embodiment, the internal voltage value is 48V, meaning that the vehicle on which the on-board device is installed conforms to, for example, the LV148 on-board power supply standard. In contrast, the external voltage value from the external power supply device is 12V, 24V, or 48V, meaning that the external power supply device includes a first external power supply device that operates at the same first voltage value (48V) as the internal voltage, and a second external power supply device that operates at a second voltage value (12V or 24V) lower than the internal voltage. The 12V or 24V is a driving voltage commonly used in gasoline-powered passenger cars and corresponds to the output voltage when jump-starting a vehicle with a 12V or 24V power supply specification. Even in such cases, the on-board device performs voltage transformation processing in a bidirectional circuit according to the internal voltage and the voltages input and output to the external power device. Therefore, vehicles compliant with the LV148 on-board power supply standard can be jump-started and charged by other vehicles, not only if other vehicles also comply with the LV148 on-board power supply standard, but also if other vehicles use 12V or 24V as their driving voltage, meaning they can help each other out.

[0027] (9) An in-vehicle device according to one aspect of the present disclosure is configured such that a plurality of in-vehicle loads are energetically connected, the in-vehicle loads include a first in-vehicle load driven at the voltage value of the internal voltage and a second in-vehicle load driven at a voltage value lower than the internal voltage, and the second in-vehicle load is connected to a step-down unit that steps down the internal voltage from the power supply device.

[0028] In this embodiment, the in-vehicle device has multiple in-vehicle loads connected to it in a way that allows them to be energized, such as various drive devices (actuators) like door mirrors, or various sensor devices like Lidars. The in-vehicle device distributes power from the power supply to each of these multiple in-vehicle loads. These in-vehicle loads include a first in-vehicle load driven at an internal voltage value (e.g., 48V) and a second in-vehicle load driven at a voltage value lower than the internal voltage (e.g., 12V or 24V). The in-vehicle device also includes a step-down unit that steps down the internal voltage from the power supply to the driving voltage of the second in-vehicle load. This step-down unit is, for example, a DC-DC converter configured with a step-down chopper circuit, and is connected (distributed) upstream of the second in-vehicle load in the direction of current flow. By having this step-down unit, the in-vehicle device can drive not only the first in-vehicle load driven at the internal voltage value, but also the second in-vehicle load driven at a voltage value lower than the internal voltage.

[0029] (10) An information processing method according to one aspect of the present disclosure operates by an internal voltage which is a voltage output from a power supply unit mounted on a vehicle, and has an external terminal to which an external power supply unit is connected from outside the vehicle and has a voltage transformation function, and a computer that controls the computer determines whether or not the power supply unit needs to be charged when the external power supply unit is connected to the external terminal, and if it is determined that the power supply unit needs to be charged, the computer charges the power supply unit by acquiring an external voltage from the external power supply unit via the bidirectional circuit, and if it is determined that the power supply unit does not need to be charged, the computer charges the external power supply unit by outputting the internal voltage from the power supply unit via the bidirectional circuit, and the computer executes a process in which the bidirectional circuit performs a voltage transformation process according to the internal voltage and the voltages input and output in the external power supply unit.

[0030] In this embodiment, an information processing method is provided that allows a computer to function as an in-vehicle device that performs voltage transformation processing in a bidirectional circuit according to the internal voltage of the power supply device and the voltages input and output at the external power supply device when performing processing related to charging with an external power supply device.

[0031] (11) A program according to one aspect of the present disclosure operates using an internal voltage which is the voltage output from a power supply unit mounted on a vehicle, and has an external terminal to which an external power supply unit is connected from outside the vehicle, and has a bidirectional circuit having a voltage transformation function, and instructs a computer that controls the external terminal to determine whether or not the power supply unit needs to be charged when the external power supply unit is connected to the external terminal, and if it is determined that the power supply unit needs to be charged, it charges the power supply unit by acquiring an external voltage from the external power supply unit via the bidirectional circuit, and if it is determined that the power supply unit does not need to be charged, it charges the external power supply unit by outputting the internal voltage from the power supply unit via the bidirectional circuit, and executes a process in which the bidirectional circuit performs a voltage transformation process according to the internal voltage and the voltages input and output in the external power supply unit.

[0032] In this embodiment, a program is provided that causes the computer to function as an in-vehicle device that performs voltage transformation processing in a bidirectional circuit according to the internal voltage of the power supply device and the voltages input and output at the external power supply device when performing processing related to charging with the external power supply device.

[0033] [Details of Embodiments of the Disclosure] The Disclosure will be described in detail based on the drawings illustrating its embodiments. An in-vehicle device 1 according to an embodiment of the Disclosure will be described below with reference to the drawings. However, the Disclosure is not limited to these examples and is intended to include all modifications within the meaning and scope of the claims, as indicated by the claims.

[0034] (Embodiment 1) Hereinafter, embodiments will be described based on the drawings. Figure 1 is a schematic diagram illustrating the configuration of an in-vehicle system S including an in-vehicle device 1 according to Embodiment 1. Figure 2 is a block diagram illustrating the internal configuration of the in-vehicle device 1. The in-vehicle system S consists of an in-vehicle device 1 mounted on a vehicle C and a power supply device 3 (auxiliary equipment) that supplies power to the in-vehicle device 1. The power supply device 3 and the in-vehicle device 1 are not limited to being directly connected by a power line 31, but may also be indirectly connected with an electrical box (junction box) such as a relay box or fuse box, or a DC-DC converter, etc., interposed between the power supply device 3 and the in-vehicle device 1.

[0035] In the in-vehicle system S, when the power supply unit 3 (auxiliary unit) fails to function due to a decrease in charge level, the external power supply unit 5 is connected to the external terminal 21 of the in-vehicle device 1 via a power receiving cable 51 such as a booster cable or battery cable, and the power supply unit 3 (auxiliary unit) is recharged and rescued by the external power supply unit 5. Furthermore, even when the external power supply unit 5 experiences battery failure, the external power supply unit 5 is connected to the external terminal 21 of the in-vehicle device 1, and the in-vehicle device 1 uses power (internal voltage) from the main unit 30 (DC / DC converter) or the power supply unit 3 (auxiliary unit) to recharge and rescue the external power supply unit 5. In this case, it is assumed that the vehicle C on which the in-vehicle device 1 is installed and the external power supply unit 5 of another vehicle have different drive voltages (battery voltages), but since the in-vehicle device 1 performs voltage transformation processing in the bidirectional circuit 22, they can charge each other, that is, they can rescue each other.

[0036] The on-board device 1 and the power supply device 3 are connected via power lines 31, and each of the multiple branched power lines 31 (distribution paths) in the on-board device 1 is connected to each of the multiple on-board loads 4. Furthermore, the on-board device 1 may also have a DC / DC converter connected as the main unit 30, which transforms the voltage from an alternator or a secondary battery such as a lithium battery. In this case, the power supply device 3, such as a Li battery, is considered an auxiliary unit. These main unit 30 (DC / DC converter) and power supply device 3 (auxiliary unit) output a voltage of, for example, 48V and may conform to the LV148 on-board power supply standard. In this way, the on-board device 1 is connected to the main unit 30 (DC / DC converter) and the auxiliary unit (power supply device 3 such as a Li battery), and the auxiliary power supply device 3 becomes the device to be charged using the external voltage from the external power device 5. When charging the external power device 5, power from the internal voltage output from the main unit 30 (DC / DC converter) may be used. The on-board device 1 may function as a power control device that distributes power from the main unit 30 (DC / DC converter) or power supply unit 3 (auxiliary unit) to each of the connected on-board loads 4, and controls the starting or stopping of each of these on-board loads 4.

[0037] The in-vehicle device 1 includes a bidirectional circuit 22, a voltage detection unit 23, and a control unit 11 composed of a microcontroller or the like. The control unit 11 (microcontroller) will be described later. One end of the bidirectional circuit 22 provided in the in-vehicle device 1 is connected to a power line 31 extending from the power supply unit 3. That is, one end of the bidirectional circuit 22 is connected to a point between the main unit 30 (DC / DC converter) and the power supply unit 3 (auxiliary equipment) in the power line 31 that connects the main unit 30 (DC / DC converter) and the power supply unit 3 (auxiliary equipment). The main unit 30 (DC / DC converter) and the power supply unit 3 (auxiliary equipment) may be connected to the power line 31 via a switchgear 25. The in-vehicle load 4 and the in-vehicle ECU 6 are also connected to the power line 31, and in this case, the in-vehicle load 4 and the in-vehicle ECU 6 may be connected to the power line 31 via a switchgear 25.

[0038] An external terminal 21 is connected to the other end of the bidirectional circuit 22. A switchgear 25 and a step-down unit 24 are arranged between the bidirectional circuit 22 and the external terminal 21 in this order. That is, the bidirectional circuit 22, the switchgear 25, the step-down unit 24, and the external terminal 21 are arranged on the power line 31 in this order. When the vehicle C on which the onboard device 1 is installed charges (relieves) the external power device 5, one end of the bidirectional circuit 22 becomes the input side and the other end becomes the output side. When the vehicle C on which the onboard device 1 is installed is charged (relieves) from the external power device 5, the other end of the bidirectional circuit 22 becomes the input side and one end becomes the output side. The bidirectional circuit 22 is electrically connected to the power line 31 and charges the power device 3 (auxiliary) by receiving power from the power supply unit 3 (auxiliary) or the main unit 30, or by supplying power to the power supply unit 3 (auxiliary).

[0039] As described above, the in-vehicle device 1 has a plurality of switchgear 25, which are composed of, for example, mechanical relays or semiconductor switches, and are connected to the control unit 11 in a communicative manner. They are controlled to be closed (on) or open (off) according to the switchgear signals (on signals / off signals) output from the control unit 11. When the control unit 11 charges the external power device 5 using the bidirectional circuit 22, or is charged by the external power device 5, it controls the switchgear 25 connected to the bidirectional circuit 22 to be closed (on). The switchgear 25 and the control unit 11 are connected, for example, via an input / output interface 14 provided by the microcontroller that constitutes the control unit 11. In this case, a signal line is extended from the input / output interface 14 to the switchgear 25, but in the illustration of this embodiment, the signal line is omitted.

[0040] The bidirectional circuit 22 is composed of, for example, a bidirectional DC / DC converter. This bidirectional DC / DC converter includes, for example, a coil and semiconductor switches such as FETs, and is configured as a step-up / step-down chopper circuit in the form of a forward type, bridge type, or flyback type, and has a voltage transformation function (step-up / step-down section) for the applied voltage. The bidirectional circuit 22 and the control unit 11 (microcontroller) are connected via signal lines through an input / output I / F 14 so as to be able to communicate. As will be described in detail later, the control unit 11 (microcontroller) controls the voltage transformation ratio by the bidirectional circuit 22 by outputting a control signal, for example, a PWM signal, to the gate terminal of an FET or the like included in the bidirectional circuit 22 (for example, a step-up / step-down chopper circuit).

[0041] The voltage detection unit 23 is configured as a voltage sensor or monitor circuit, and detects the voltage value of the voltage output from the external power device 5 connected to the external terminal 21. The detected voltage value is output to the control unit 11 (microcontroller) via a signal line extending from the input / output I / F 14. Furthermore, the voltage detection unit 23 and the control unit 11 (microcontroller) are also connected by a power line. The voltage detection unit 23 supplies power from the external voltage applied from the external power device 5 to the control unit 11 (microcontroller) to drive the control unit 11 (microcontroller). The external voltage applied from the external power device 5 may be the same voltage value as the internal voltage of the power supply unit 3 (auxiliary equipment) (for example, 48V), or it may be a lower voltage value than the internal voltage (for example, 12V or 24V). The microcontroller constituting the control unit 11 may be equipped with a regulator or a DC-DC converter to transform the input voltage into the driving voltage of the microcontroller. As the microcontroller constituting the control unit 11 has a regulator, etc., even if the power supply unit 3 (auxiliary equipment) runs out of battery power, the control unit 11 (microcontroller) can be driven using the voltage applied from the external power supply unit 5.

[0042] For each of the in-vehicle loads 4, an opening / closing device 25 such as a relay is arranged on each of the power lines 31 (distribution paths) branched into a plurality. In each of the power lines 31 (distribution paths) branched into a plurality, an in-vehicle load 4 is connected on the downstream side of the opening / closing device 25 in the direction of the current flow from the host device 30 (DC / DC converter) or the power supply device 3 (auxiliary machine). The in-vehicle load 4 includes a first in-vehicle load 41 (48V load) driven at the voltage value of the internal voltage (for example, 48V) from the power supply device 3 (auxiliary machine) and a second in-vehicle load 42 (12V load) driven at a voltage value lower than the internal voltage (for example, 12V).

[0043] A step-down unit 24 is connected to the power line 31 (distribution path) to which the second in-vehicle load 42 (12V load) is connected, together with the opening / closing device 25. The step-down unit 24 is arranged between the opening / closing device 25 and the branch point on the power line 31. The step-down unit 24 is, for example, a DC-DC converter configured by a step-down chopper circuit, and is connected (arranged) on the upstream side of the second in-vehicle load 42 in the direction of the current flow, and steps down the internal voltage (for example, 48V) applied from the host device 30 (DC / DC converter) or the power supply device 3 (auxiliary machine) to the drive voltage (for example, 12V) of the second in-vehicle load 42.

[0044] The in-vehicle load 4 is, for example, an actuator such as a car air conditioner, a lamp, or a drive motor. These in-vehicle loads 4 and the like are supplied with power or the power supply is cut off according to the opening / closing control (on / off control) of the opening / closing device 25 arranged on each of the power lines 31 (distribution paths) branched into a plurality, and are thereby started or stopped. The in-vehicle device 1 functions as a power control device that controls the start or stop of the in-vehicle load 4 and the like by performing the opening / closing control (on / off control) of these opening / closing devices 25.

[0045] Multiple branched power lines 31 (distribution paths) may be connected to an in-vehicle ECU 6. The in-vehicle ECU 6 includes a microcontroller with communication functions and performs predetermined calculation processing based on detected values ​​from sensors or output values ​​from various switches. An HMI device 103, such as a display, may be connected to any of the in-vehicle ECU 6. The in-vehicle ECU 6 and the in-vehicle device 1 are connected to communicate via an in-vehicle network using a communication protocol such as CAN, CAN-FD, or Ethernet (registered trademark).

[0046] An external communication device 101 is further connected to the in-vehicle network. The external communication device 101 is a communication device for wireless communication using mobile communication protocols such as LTE®, 4G, 5G, and Wi-Fi®, and transmits and receives data with an information terminal 102 such as a smartphone or an external server via an antenna connected to the external communication device 101.

[0047] The on-board device 1 may function as a power control device that controls the starting or stopping of on-board loads 4, etc., and may also be a device that has a relay function such as a CAN gateway. Alternatively, the on-board device 1 may be an integrated ECU (vehicle computer) that comprehensively controls the entire vehicle C and has a relay function. Alternatively, the on-board device 1 may be individual ECUs connected under the integrated ECU and located in each area of ​​the vehicle C. Alternatively, the on-board device 1 may be configured as a body ECU, etc., to which various switches, sensors, or actuators, on-board loads 4 are connected, and which controls the body system actuators of the vehicle C. Alternatively, the on-board device 1 may be a PLB (Power LAN Box) that, in addition to relaying communications, also functions as a power distribution device that distributes and relays power output from a power supply device 3 such as a secondary battery and supplies power to on-board loads 4 such as actuators.

[0048] The off-vehicle power device 5 is, for example, a battery of another vehicle C (other vehicle) or a portable battery, and outputs a predetermined voltage. When the off-vehicle power device 5 and the vehicle C are connected in a power-on state by the power receiving cable 51, a jump start can be performed between the off-vehicle power device 5 and the vehicle C, and they can charge each other and rescue each other.

[0049] The off-vehicle power device 5 includes a first off-vehicle power device 501 and a second off-vehicle power device 502. The first off-vehicle power device 501 outputs a first voltage value (48 V) that is the same as the internal voltage of the power supply device 3 (auxiliary machine), and charging is performed with the first voltage value. The second off-vehicle power device 502 outputs a second voltage value (12 V or 24 V) that is lower than the internal voltage of the power supply device 3 (auxiliary machine), and charging is performed with the second voltage value.

[0050] The in-vehicle device 1 includes a control unit 11, a storage unit 12, a communication unit 13, and an input / output I / F 14, and these control unit 11 etc. may be configured by a microcomputer (microcontroller). Further, as described above, the in-vehicle device 1 includes a bidirectional circuit 22 and a voltage detection unit 23 for input / output processing of sensor values, control signals, etc. between itself and a control unit 11 configured by a microcontroller or the like.

[0051] The control unit 11 is configured by a CPU (Central Processing Unit) or an MPU (Micro Processing Unit) etc., and reads and executes a control program P (program product) and data stored in advance in the storage unit 12, so as to perform various control processes and arithmetic processes etc.

[0052] The storage unit 12 is composed of volatile memory elements such as RAM (Random Access Memory), non-volatile memory elements such as ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable ROM), or flash memory, or a combination of these storage devices, and stores in advance the control program P (program product) and data referenced during processing. The control program P (program product) stored in the storage unit 12 may be a control program P (program product) read from a recording medium M that the in-vehicle device 1 can read. Alternatively, the control program P (program product) may be downloaded from an external computer (not shown) connected to a communication network (not shown) and stored in the storage unit 12.

[0053] The communication unit 13 is an input / output interface using a communication protocol such as CAN, CAN-FD, or Ethernet (Ethernet / registered trademark), and the control unit 11 communicates with the in-vehicle ECU 6 or external communication device 101 connected to the in-vehicle network via the communication unit 13. In the in-vehicle device 1, there may be multiple communication units 13.

[0054] The input / output interface 14 is, for example, a communication interface for serial communication. The input / output interface 14 includes a plurality of terminals (output terminals), and each terminal may be connected to a signal line extending to the bidirectional circuit 22, the voltage detection unit 23, and each of the plurality of switchgears 25. The signal line is composed of, for example, a serial cable, a wire harness, or a conductive cable (direct wire) that transmits only one signal.

[0055] Figure 3 is a flowchart illustrating the processing of the control unit 11 of the in-vehicle device 1. When the external power device 5 is connected to the vehicle C, the control unit 11 of the in-vehicle device 1 performs the following processing.

[0056] The control unit 11 of the in-vehicle device 1 determines whether or not the external power device 5 is connected to the external terminal 21 (S101). The external terminal 21 is connected by a power line 31 extending from the bidirectional circuit 22 of the in-vehicle device 1. The power receiving cable 51 connected to the external power device 5 is fitted to the external terminal 21, thereby enabling power to flow between the external power device 5 and the voltage detection unit 23, which is configured, for example, as a monitor circuit, via the power receiving cable 51 and the external terminal 21. For example, the voltage detection unit 23 detects a change in the potential of the pins of the external terminal 21, and the detection result is output to the control unit 11. This allows the control unit 11 to determine whether or not the external power device 5 is connected to the external terminal 21.

[0057] If the power supply unit 3 (auxiliary equipment) experiences a battery failure or other power loss, the voltage detection unit 23 may use the external voltage output from the external power supply unit 5 to drive the microcontroller constituting the control unit 11. In this case, the power supply specifications of the control unit 11 are configured to be driven by the external voltage applied from the external power supply unit 5, that is, it is configured to be driven not only when the external voltage is 48V, but also when it is 12V or 24V. In this case, the microcontroller constituting the control unit 11 may be equipped with a regulator, or the voltage detection unit 23 may be equipped with a regulator. If the power supply unit 3 (auxiliary equipment) is not experiencing a battery failure or other power loss, and is operating normally (outputting an internal voltage of the rated voltage value), the control unit 11 is driven by the power supplied from the power supply unit 3 (auxiliary equipment) or the main unit 30 (DC / DC converter).

[0058] If the external power supply 5 is not connected to the external terminal 21 (S101: NO), the control unit 11 of the in-vehicle device 1 continues the process of detecting whether or not the external power supply 5 is connected to the external terminal 21 by performing a loop process to execute S101 again.

[0059] When an external power supply 5 is connected to the external terminal 21 (S101: YES), the control unit 11 of the in-vehicle device 1 acquires the voltage value of the internal voltage from the power supply 3 (S102). The control unit 11 (microcontroller) and the power supply 3 are connected in a way that allows power to flow through the power line 31, and the control unit 11 can detect the voltage value of the internal voltage output from the power supply 3. In this case, the microcontroller constituting the control unit 11 may have a voltage sensor, or it may acquire the voltage value detected by a voltage sensor installed on the power line 31 extending from the power supply 3 to the control unit 11 (microcontroller).

[0060] The control unit 11 of the in-vehicle device 1 determines whether the acquired voltage value is below the charging threshold (S103). The charging threshold is pre-stored in the memory unit 12 of the microcontroller that constitutes the control unit 11. The charging threshold is predetermined by the battery characteristics or product specifications of the power supply unit 3 (auxiliary equipment) as a threshold value for the output voltage value used to determine whether or not a battery failure has occurred in the power supply unit 3 (auxiliary equipment). For example, if the rated voltage value of the internal voltage output from the power supply unit 3, i.e., the voltage value for which operation is guaranteed, is 48V, the charging threshold may be set at that rated voltage value, or the charging threshold may be set based on a predetermined coefficient, such as 99% of the rated voltage value.

[0061] In this embodiment, the means for determining whether or not a battery failure has occurred in the power supply unit 3 (auxiliary unit) is to compare the voltage value of the internal voltage from the power supply unit 3 with the charging threshold, but is not limited to this. The control unit 11 of the in-vehicle device 1 may determine whether or not a battery failure has occurred in the power supply unit 3 (auxiliary unit) depending on the communication status in the in-vehicle network, such as the presence or absence of messages flowing on the in-vehicle network via the communication unit 13. That is, the control unit 11 of the in-vehicle device 1 may determine that a battery failure has occurred in the power supply unit 3 (auxiliary unit) if no messages are transmitted on the in-vehicle network, or if communication with the in-vehicle ECU 6 that controls the power supply unit 3 (auxiliary unit) is not possible. Alternatively, if a battery failure occurs in the power supply unit 3 (auxiliary unit), the power to drive the control unit 11 (microcontroller) is the external voltage applied from the external power supply unit 5 via the external terminal 21 and the voltage detection unit 23. Therefore, the control unit 11 (microcontroller) may determine that a battery failure has occurred in the power supply unit 3 (auxiliary equipment) if the supplied power is an external voltage from the external power supply unit 5.

[0062] If the charge threshold is below (S103: YES), the control unit 11 of the in-vehicle device 1 determines that charging of the power supply unit 3 is necessary (S104). If the charge threshold is below, the control unit 11 of the in-vehicle device 1 determines that the battery in the power supply unit 3 (auxiliary) is dead and that charging of the power supply unit 3 is necessary.

[0063] The control unit 11 of the in-vehicle device 1 acquires the voltage value of the external voltage from the external power device 5 (S105). The voltage detection unit 23 connected to the external terminal 21 detects the voltage value of the external voltage applied from the external power device 5 and outputs the detected voltage value to the control unit 11. The control unit 11 of the in-vehicle device 1 may also acquire the voltage value (voltage value of the external voltage) from the voltage detection unit 23 and store the acquired voltage value in the storage unit 12 in association with the time of acquisition.

[0064] The control unit 11 of the in-vehicle device 1 determines whether the voltage value of the external voltage is the same as the voltage value of the internal voltage (S106). The control unit 11 determines whether the voltage value of the internal voltage output from the power supply unit 3 (auxiliary equipment), i.e., the rated voltage value of the internal voltage (for example, 48V), is the same as the voltage value of the external voltage. The rated voltage value (for example, 48V) is stored in advance in the storage unit 12. In this embodiment, "the voltage values ​​are the same" is not limited to cases where these voltage values ​​are exactly the same, but also includes cases where they are substantially identical in terms of the product specifications or operational guarantees of the in-vehicle device 1 or the power supply unit 3.

[0065] If they are the same (S106: YES), the control unit 11 of the in-vehicle device 1 outputs the external voltage from the external power device 5 to the power supply device 3 without transforming it (S107). When the external voltage and the internal voltage are the same voltage value, the control unit 11 determines that the external power device 5 corresponds to the first external power device 501 (48V vehicle). When the external voltage and the internal voltage are the same voltage value, that is, for example, both are 48V, it is unnecessary to transform (boost) the external voltage in the bidirectional circuit 22, which is composed of a bidirectional DC / DC converter, for example. In this way, when the external voltage and the internal voltage are the same voltage value (48V), the control unit 11 charges the power supply device 3 by outputting the external voltage to the power supply device 3 without transforming the external voltage using the bidirectional circuit 22.

[0066] If they are not the same (S106: NO), the control unit 11 of the in-vehicle device 1 outputs the external voltage boosted using the transformer function of the bidirectional circuit 22 to the power supply device 3 (S1061). If the external voltage and the internal voltage are not the same voltage value, the control unit 11 determines that the external power device 5 corresponds to the second external power device 502 (12V vehicle or 24V vehicle: 12V etc. vehicle). If the external voltage and the internal voltage are not the same voltage value, that is, for example, if the external voltage is 12V and the internal voltage is 48V, it becomes necessary to transform (boost) the external voltage by four times in the bidirectional circuit 22, which is composed of a bidirectional DC / DC converter, for example. Therefore, if the external voltage (12V) and the internal voltage (48V) are not the same voltage value, the control unit 11 calculates the boost ratio according to the ratio of the internal voltage to the external voltage (4 = 48 / 12), and generates and outputs a control signal such as a PWM signal according to the calculated boost ratio. In this case, the control unit 11 may output the control signal (PWM signal) to the gate terminal of an FET or the like of a step-up / step-down chopper circuit that performs a voltage transformation function in the bidirectional circuit 22. In this way, when the external voltage (12V) and the internal voltage (48V) are different voltage values, the control unit 11 boosts the external voltage using the bidirectional circuit 22 and outputs the boosted external voltage to the power supply unit 3, thereby charging the power supply unit 3.

[0067] If the voltage is not below the charging threshold (S103: NO), the control unit 11 of the on-board device 1 determines that charging of the power supply unit 3 is unnecessary (S1031). The fact that the internal voltage from the power supply unit 3 (auxiliary unit) is not below the charging threshold, that is, that the internal voltage from the power supply unit 3 is equal to or greater than the charging threshold, indicates that the power supply unit 3 is operating normally. Therefore, if the voltage is not below the charging threshold, the control unit 11 of the on-board device 1 determines that the power supply unit 3 is operating normally, that charging of the power supply unit 3 is unnecessary, and that charging of the external power supply unit 5 connected to the external terminal 21 is necessary by the power supply unit 3 (auxiliary unit) or the main unit 30. Thus, the determination result that charging of the power supply unit 3 is unnecessary and the determination result that charging of the external power supply unit 5 is necessary are substantially synonymous.

[0068] The control unit 11 of the in-vehicle device 1 acquires the voltage value from the external power device 5 (S1032). The control unit 11 acquires the voltage from the external power device 5 detected by the voltage detection unit 23. At this time, it is assumed that the external power device 5 is another vehicle whose battery has died. Therefore, the voltage from the external power device 5 (other vehicle) is lower than the voltage output by the battery of that other vehicle when it is functioning normally.

[0069] The control unit 11 of the in-vehicle device 1 determines whether the acquired voltage value of the external power device 5 is below a determination threshold (S1033). The determination threshold is stored in the memory unit 12 of the microcontroller constituting the control unit 11 and is used as a parameter to determine whether the external power device 5 (other vehicle) is a 48V vehicle that uses 48V, the same as the internal voltage of the power supply device 3 (auxiliary equipment), as its driving power source, or a 12V vehicle that uses 12V or the like as its driving power source. The determination threshold may be set to, for example, 5V, or it may be set to the maximum voltage output from the battery of the first external power device 501 (48V vehicle) when the battery of the first external power device 501 (48V vehicle) runs out.

[0070] If the first external power device 501 is, for example, the battery of another vehicle (a 48V vehicle) that uses 48V as its drive power source, it is assumed that the other vehicle is an EV (Electric Vehicle), HV (Hybrid Vehicle), or PHEV (Plug-in Hybrid Electric Vehicle), and is equipped with a high-voltage battery such as a lithium secondary battery. In this case, if the SOC of the other vehicle's high-voltage and low-voltage batteries falls below a predetermined value, the voltage output to the outside will be a relatively low voltage, such as 0V to 5V. In contrast, if a lead-acid battery in a gasoline vehicle (which operates normally at 12.4V or higher) fails, the voltage output from the failed lead-acid battery will be 12.3V or less and greater than 5V. In this manner, for each of the other vehicles that are individual external power devices 5, a determination threshold (for example, 5V) is set to determine whether it is the first external power device 501 (48V vehicle) or the second external power device 502 (12V vehicle, etc.) depending on the voltage output specifications or characteristics when a battery failure occurs.

[0071] If the voltage is below the threshold (S1033: YES), the control unit 11 of the on-board device 1 outputs the internal voltage from the power supply 3 to the external power supply 5 without transforming it (S1034). If the voltage value from the external power supply 5 is below the threshold, the control unit 11 of the on-board device 1 determines that the external power supply 5 (another vehicle) connected to the external terminal 21 is the first external power supply 501 (a 48V vehicle). In this case, both the vehicle C on which the on-board device 1 is installed and the first external power supply 501 (the other vehicle to be rescued) connected to the external terminal 21 use the same drive voltage (48V), and it is not necessary to transform (step down) the internal voltage in the bidirectional circuit 22, which is composed of a bidirectional DC / DC converter, for example. Therefore, if the internal voltage is below the determination threshold, the control unit 11 outputs the internal voltage to the first external power device 501 (the other vehicle to be rescued) without transforming the external voltage using the bidirectional circuit 22, thereby recharging the first external power device 501 and providing rescue.

[0072] If the voltage is not below the threshold (S1033: NO), the control unit 11 of the on-board device 1 outputs the internal voltage, which has been stepped down using the transformer function of the bidirectional circuit 22, to the external power device 5 (S10331). If the voltage value from the external power device 5 is not below the threshold, that is, if it exceeds the threshold, the control unit 11 of the on-board device 1 determines that the external power device 5 (another vehicle) connected to the external terminal 21 is a second external power device 502 (a 12V vehicle, etc.). If the voltage is not below the threshold, it becomes necessary to transform (step down) the internal voltage to 1 / 4 times its original value (1 / 4 = 12V / 48V) in the bidirectional circuit 22, which is composed of a bidirectional DC / DC converter, for example. Therefore, if the internal voltage is not below the threshold, the control unit 11 calculates a step-down ratio according to the ratio (1 / 4 = 12V / 48V) of the internal voltage and the driving voltage (battery voltage) of the second external power device 502 (12V vehicle, etc.), generates a control signal such as a PWM signal according to the calculated step-down ratio, and outputs it to the bidirectional circuit 22. As a result, the control unit 11 uses the stepped-down internal voltage to charge and rescue the second external power device 502 (12V vehicle, etc.).

[0073] (Embodiment 2) Figure 4 is a flowchart illustrating the processing of the control unit 11 of the in-vehicle device 1 according to Embodiment 2 (selection screen). When the external power device 5 is connected to the vehicle C, the control unit 11 of the in-vehicle device 1 performs the following processing.

[0074] The control unit 11 of the in-vehicle device 1 determines whether or not the external power device 5 is connected to the external terminal 21 (S201). The control unit 11 of the in-vehicle device 1 acquires the voltage value of the internal voltage from the power supply device 3 (S202). The control unit 11 of the in-vehicle device 1 determines whether or not the acquired voltage value is below the charging threshold (S203). The control unit 11 of the in-vehicle device 1 determines that charging of the power supply device 3 is necessary (S204). The control unit 11 of the in-vehicle device 1 acquires the voltage value of the external voltage from the external power device 5 (S205). The control unit 11 of the in-vehicle device 1 determines whether or not the voltage value of the external voltage is the same as the voltage value of the internal voltage (S206). The control unit 11 of the in-vehicle device 1 outputs the external voltage from the external power device 5 to the power supply device 3 without transforming it (S207). The control unit 11 of the in-vehicle device 1 outputs an external voltage boosted using the voltage transformation function of the bidirectional circuit 22 to the power supply device 3 (S2061). The control unit 11 of the in-vehicle device 1 determines that charging the power supply device 3 is unnecessary (S2031). The control unit 11 of the in-vehicle device 1 executes the processes of S201 to S2061 and S2031 in the same manner as S101 to S1061 and S1031 in Embodiment 1.

[0075] The control unit 11 of the on-board device 1 outputs a selection screen for selecting whether or not to reduce the internal voltage (S2032). When the control unit 11 determines that charging the power supply 3 is unnecessary, that is, when it determines that charging (rescue) is necessary for the external power supply 5 connected to the external terminal 21, it will charge the external power supply 5 (other vehicle) that has experienced battery failure or the like. At this time, the operator of vehicle C will select whether the external power supply 5 (other vehicle) is a first external power supply 501 (48V vehicle) which has the same drive voltage (48V) as the vehicle C (own vehicle) on which the on-board device 1 is installed, or a second external power supply 502 (12V etc. vehicle) which has a different drive voltage (12V etc.). In response, the control unit 11 of the in-vehicle device 1 outputs the selection screen, for example, to an information terminal 102 used by the operator via an external communication device 101, or to an in-vehicle ECU 6 that controls an HMI device 103 such as a display, and the selection screen is displayed on the HMI device 103.

[0076] Figure 5 is an explanatory diagram illustrating a selection screen. The selection screen is displayed on the display of an information terminal 102, such as a smartphone, used by the operator, and includes a button for selecting the first external power device 501 (48V vehicle) "48V (no step-down required)" and a button for selecting the second external power device 502 (12V vehicle) "12V (step-down required)". When either button is pressed on the selection screen by the operator, the selection is accepted, and the accepted selection result is transmitted from the information terminal 102 to the in-vehicle device 1.

[0077] The selection result includes information indicating either 48V (no step-down required) or 12V (step-down required). The control unit 11 of the in-vehicle device 1 can obtain the selection result transmitted from the information terminal 102 to identify whether the external power device 5 is the first external power device 501 (48V vehicle) or the second external power device 502 (12V vehicle), and to determine whether step-down is required.

[0078] The selection screen may also display the determination result from the control unit 11 for reference. The control unit 11 may, for example, perform the same processing as in the first embodiment (S1032 to S1033) to determine whether the external power device 5 connected to the external terminal 21 is the first external power device 501 (48V vehicle) or the second external power device 502 (12V vehicle), and output and display the determination result on the selection screen.

[0079] The control unit 11 of the in-vehicle device 1 determines whether the selection indicates that voltage reduction is unnecessary (S2033). The control unit 11 of the in-vehicle device 1 obtains the selection result received on the selection screen from the information terminal 102, and determines whether voltage reduction is unnecessary based on the obtained selection result.

[0080] If it is indicated that voltage reduction is not required (S2033: YES), the control unit 11 of the in-vehicle device 1 outputs the internal voltage from the power supply unit 3 to the external power supply unit 5 without transforming the voltage (S2034). The control unit 11 of the in-vehicle device 1 executes the process of S2034 in the same way as S1034 in Embodiment 1.

[0081] If the system does not indicate that voltage reduction is unnecessary (S2033: NO), that is, if it indicates that voltage reduction is necessary, the control unit 11 of the on-board device 1 outputs the internal voltage, which has been reduced using the voltage transformation function of the bidirectional circuit 22, to the external power device 5 (S20331). The control unit 11 of the on-board device 1 executes the process of S20331 in the same manner as S10331 in Embodiment 1.

[0082] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims and not in the sense described above, and all modifications within the sense and scope equivalent to the claims are intended to be included.

[0083] With respect to the multiple claims described in the claims, they may be combined with each other regardless of the form of reference. Multiple dependent claims that depend on multiple claims may be described in the claims. Multiple dependent claims that depend on multiple dependent claims may be described. Even if multiple dependent claims that depend on multiple dependent claims are not described, this does not limit the description of multiple dependent claims that depend on multiple dependent claims.

[0084] C Vehicle S In-vehicle system 101 External communication device 102 Information terminal 103 HMI device 1 In-vehicle device 11 Control unit (microcontroller) 12 Memory unit M Recording medium P Control program (program product) 13 Communication unit 14 Input / output I / F 21 External terminal 22 Bidirectional circuit (bidirectional DC / DC converter) 23 Voltage detection unit (monitor circuit) 24 Step-down unit 25 Switching device (SW) 3 Power supply unit (auxiliary equipment) 30 Main unit (DC / DC converter) 31 Power line 4 In-vehicle load 41 First in-vehicle load 42 Second in-vehicle load 5 External power supply unit 501 First external power supply unit (48V vehicle) 502 Second external power supply unit (12V vehicle) 51 Power receiving cable 6 In-vehicle ECU

Claims

1. An in-vehicle device that operates using an internal voltage, which is the voltage output from a power supply unit mounted on a vehicle, the device comprising: an external terminal to which an external power supply unit is connected from outside the vehicle; a bidirectional circuit having a voltage transformation function; and a control unit that controls the bidirectional circuit, wherein the control unit determines whether or not to charge the power supply unit when the external power supply unit is connected to the external terminal; if it determines that charging the power supply unit is necessary, it charges the power supply unit by acquiring an external voltage from the external power supply unit via the bidirectional circuit; if it determines that charging the power supply unit is unnecessary, it charges the external power supply unit by outputting the internal voltage from the power supply unit via the bidirectional circuit; and the bidirectional circuit performs voltage transformation processing according to the internal voltage and the voltages input and output in the external power supply unit.

2. The in-vehicle device according to claim 1, wherein the control unit acquires the voltage value of the voltage output from the power supply device, determines that charging of the power supply device is necessary if the acquired voltage value of the power supply device is less than a predetermined charging threshold, and determines that charging of the power supply device is unnecessary if it is above the charging threshold.

3. The in-vehicle device according to claim 1, wherein the external power device includes a first external power device that is driven at the same first voltage value as the internal voltage and a second external power device that is driven at a second voltage value lower than the internal voltage, and the control unit, when it determines that charging the power supply is unnecessary, obtains the voltage value of the voltage applied from the external power device, determines whether the external power device is the first external power device or the second external power device based on the obtained voltage value of the external power device, and if it is determined to be the first external power device, outputs the internal voltage from the power supply to the first external power device without transforming it, and if it is determined to be the second external power device, outputs the internal voltage, which has been stepped down to the second voltage value by the bidirectional circuit, to the second external power device.

4. The in-vehicle device according to claim 3, wherein the control unit determines that the external power device is the first external power device if the acquired voltage value of the external power device is less than or equal to a predetermined determination threshold, and determines that the external power device is the second external power device if the acquired voltage value of the external power device exceeds the determination threshold.

5. The in-vehicle device according to claim 1, wherein the external power device includes a first external power device that is driven at the same first voltage value as the internal voltage and a second external power device that is driven at a second voltage value lower than the internal voltage, and when the control unit determines that charging the power supply is unnecessary, it outputs a selection screen to the external power device for selecting whether or not to step down the internal voltage by the bidirectional circuit when outputting the internal voltage from the power supply via the bidirectional circuit, and obtains the selection received on the selection screen, and if the obtained selection indicates that step-down is necessary, it outputs the internal voltage, which has been stepped down to the second voltage value by the bidirectional circuit, to the external power device, and if the obtained selection indicates that step-down is unnecessary, it outputs the internal voltage from the power supply to the external power device without transforming it.

6. The in-vehicle device according to claim 1, wherein the external power device includes a first external power device that outputs a first voltage value the same as the internal voltage, and a second external power device that outputs a second voltage value lower than the internal voltage, and when the control unit determines that it is necessary to charge the power supply device, it obtains the voltage value of the external voltage from the external power device, determines whether the external power device is the first external power device or the second external power device based on the obtained voltage value of the external voltage, and if it is determined to be the first external power device, it outputs the external voltage from the external power device to the power supply device without transforming it, and if it is determined to be the second external power device, it outputs the external voltage boosted to the first voltage value by the bidirectional circuit to the power supply device.

7. The in-vehicle device according to claim 1, wherein the bidirectional circuit is a bidirectional DC / DC converter, the control unit derives a voltage transformation ratio in the bidirectional circuit according to the ratio of the external voltage to the internal voltage, and controls the bidirectional circuit with the derived voltage transformation ratio.

8. The in-vehicle device according to claim 1, wherein the voltage value of the internal voltage is 48V, and the voltage value of the external voltage is 12V, 24V, or 48V.

9. The in-vehicle device according to claim 1, wherein a plurality of in-vehicle loads are energetically connected, the in-vehicle loads include a first in-vehicle load driven at the voltage value of the internal voltage and a second in-vehicle load driven at a voltage value lower than the internal voltage, and the in-vehicle device is connected to the second in-vehicle load and comprises a step-down unit for stepping down the internal voltage from the power supply device.

10. An information processing method that causes a computer to control a bidirectional circuit having a voltage transformation function, which operates using an internal voltage that is the voltage output from a power supply unit mounted on a vehicle, and is provided with an external terminal to which an external power supply unit is connected from outside the vehicle, to determine whether or not the power supply unit needs to be charged when the external power supply unit is connected to the external terminal, and if it is determined that the power supply unit needs to be charged, it charges the power supply unit by acquiring the external voltage from the external power supply unit via the bidirectional circuit, and if it is determined that the power supply unit does not need to be charged, it charges the external power supply unit by outputting the internal voltage from the power supply unit via the bidirectional circuit, and performs a voltage transformation process in the bidirectional circuit according to the internal voltage and the voltages input and output in the external power supply unit.

11. A program that controls a bidirectional circuit having a voltage transformation function, which operates using an internal voltage that is the voltage output from a power supply unit mounted on a vehicle, and is provided with an external terminal to which an external power supply unit is connected from outside the vehicle, to determine whether or not the power supply unit needs to be charged when the external power supply unit is connected to the external terminal, and if it is determined that the power supply unit needs to be charged, it charges the power supply unit by acquiring the external voltage from the external power supply unit via the bidirectional circuit, and if it is determined that the power supply unit does not need to be charged, it charges the external power supply unit by outputting the internal voltage from the power supply unit via the bidirectional circuit, and executes a process in which the bidirectional circuit performs a voltage transformation according to the internal voltage and the voltages input and output in the external power supply unit.

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