vehicle

Abstract

This invention prevents program updates from being interrupted due to insufficient power. The vehicle includes: a high-voltage system circuit including a high-voltage battery; a low-voltage system circuit including a low-voltage battery with an output voltage lower than the high-voltage battery and an update unit that uses power supplied from the low-voltage battery or the high-voltage battery to perform updates of a program for an updated device; a DC-DC converter connected between the high-voltage system circuit and the low-voltage system circuit, capable of stepping down the output power of the high-voltage battery to supply power to the update unit of the low-voltage system circuit; and a control unit that sets a target charge rate range for the high-voltage battery and controls the charging of the high-voltage battery based on the target charge rate range. When an update of the program for the updated device is scheduled, the control unit changes the lower limit of the target charge rate of the high-voltage battery to a higher value than normally.

Description

Technical Field

[0001] This invention relates to vehicles. Background Technology

[0002] In recent years, technologies have been proposed to update (hereinafter referred to as "reprogramming") the programs of electronic control units (hereinafter also referred to as "ECUs") used to control the engine and / or motor, on-board devices, etc. in a vehicle.

[0003] Typically, reprogramming is performed when the vehicle and engine are stopped. Therefore, reprogramming is performed using the power stored in a battery such as a 12V auxiliary battery (low-voltage battery) (e.g., Patent Document 1).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-166434 Summary of the Invention

[0007] Technical issues

[0008] In recent years, due to the increase in program size, there has been a trend of longer reprogramming times. Since longer reprogramming times mean higher power requirements, program updates may be interrupted due to insufficient power if the battery is not fully charged during reprogramming.

[0009] In view of this problem, the present invention aims to provide a vehicle capable of preventing program updates from being interrupted due to insufficient power.

[0010] Technical solution

[0011] To address the aforementioned issues, the vehicle of the present invention includes: a high-voltage system circuit comprising a high-voltage battery; a low-voltage system circuit comprising a low-voltage battery having an output voltage lower than that of the high-voltage battery, and an update unit that uses power supplied from the low-voltage battery or the high-voltage battery to perform an update of a program for updating a target device; a DC-DC converter connected between the high-voltage system circuit and the low-voltage system circuit, capable of stepping down the output power of the high-voltage battery to supply power to the update unit of the low-voltage system circuit; and a control unit that sets a range of a target charging rate for the high-voltage battery and controls the charging of the high-voltage battery based on the range of the target charging rate, wherein when an update of the program for the target device is scheduled, the control unit changes the lower limit of the target charging rate of the high-voltage battery to a value higher than the normal value.

[0012] Additionally, the vehicle may also be equipped with a wireless communication unit that can communicate wirelessly with external devices. When the wireless communication unit receives update data for updating the program of the device to be updated, the control unit determines that the update of the program of the device to be updated has been scheduled, and the update unit performs the update of the program of the device to be updated based on the update data.

[0013] In addition, when the update data is received by the wireless communication unit, the control unit may also derive the power required to update the program of the device to be updated based on information related to the update data, and change the lower limit of the target charging rate of the high-voltage battery based on the derived power.

[0014] Alternatively, the vehicle may also have an engine as a driving source and a motor connected to the high-voltage battery as a driving source.

[0015] Technical effect

[0016] According to the present invention, it is possible to prevent program updates from being interrupted due to insufficient power. Attached Figure Description

[0017] Figure 1 This is a functional block diagram of the vehicle used to illustrate this embodiment.

[0018] Figure 2 This is a block diagram showing the electrical system circuit controlled by the control device of this embodiment.

[0019] Figure 3 This diagram illustrates the control of the target charging rate of the high-voltage battery performed by the high-voltage battery control unit of this embodiment.

[0020] Figure 4 This is a diagram illustrating the reprogramming execution license screen of this embodiment.

[0021] Figure 5 This is a flowchart illustrating the control process for reprogramming the vehicle in this embodiment.

[0022] Figure 6 This is a flowchart illustrating the vehicle reprogramming operation control process of this embodiment.

[0023] Symbol Explanation

[0024] 22: Control device (control unit)

[0025] 30: High-voltage system circuits

[0026] 32: High-voltage storage battery

[0027] 32a: High-voltage battery control unit

[0028] 40: Low-voltage system circuits

[0029] 42: Low-voltage storage battery

[0030] 42a: Low-voltage battery control unit

[0031] 44: Update the target device

[0032] 46: Update Department

[0033] 50a: Wireless Communications Department

[0034] 60: DC-DC converter

[0035] 102: Data Transmission Center (External Device) Detailed Implementation

[0036] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific values ​​shown in these embodiments are merely examples for easy understanding of the invention and are not intended to limit the invention unless specifically stated otherwise. It should be noted that in this specification and the accompanying drawings, elements having substantially the same function or structure are omitted by using the same symbols to avoid repetitive descriptions, and illustrations of elements not directly related to the present invention are also omitted.

[0037] Figure 1 This is a functional block diagram illustrating the vehicle 1 of this embodiment. Here, a vehicle 1 is illustrated, having an engine 10 and a motor 12 as driving sources. The vehicle 1 of this embodiment is equivalent to a so-called parallel hybrid vehicle, and primarily uses the engine 10 as the power source to rotate the output shaft 14. Although the three-phase AC motor 12 is the power source, it serves as an auxiliary power source to the engine 10. This driving mode, where the engine 10 and motor 12 are used in parallel, is referred to as the parallel driving mode.

[0038] Furthermore, since the power or torque of engine 10 does not increase during low-speed driving, such as when starting or accelerating, the clutch 16 is released, and the driving mode switches from the combined driving mode to EV (Electric Vehicle) mode, which uses only motor 12 as the power source. It should be noted that, except during starting or acceleration, the combined driving mode and EV mode can also be switched according to driving conditions.

[0039] The ISG (Integrated Starter Generator) 18 is connected to the engine 10 via a tensioned belt 20 and other annular components between itself and the output shaft 14 of the engine 10, and transmits power to the engine 10. It functions as a starter motor to assist in starting the engine 10, and also as an alternator for regenerative power generation. Here, the timing for starting the engine 10 is considered not only when the vehicle 1 begins to move, but also when switching from EV mode to combined mode, and when resuming from idle stop, among other times.

[0040] The control device 22 includes a semiconductor integrated circuit, which includes a central processing unit (CPU), a ROM storing programs, and RAM serving as a working area. The control device 22 controls the entire vehicle 1 or various devices mounted on the vehicle 1. For example, the control device 22 controls a high-voltage battery 32 (described later). Figure 2 ) and low-voltage storage battery 42 (refer to Figure 2 The various parts of the electrical system circuit.

[0041] Additionally, the control device 22 and the wireless communication unit 50a (see reference) Figure 2 The device is connected to and can send and receive various data with external devices via the wireless communication unit 50a. The wireless communication unit 50a can communicate wirelessly with the data transmission center 102 via the network 100. The data transmission center 102 performs the function of transmitting reprogramming information (hereinafter also referred to as "reprogramming information") required for updating the program (hereinafter also referred to as "reprogramming" or "reprogramming"), which is used to control the update target device 44 mounted on the vehicle 1. The reprogramming information includes, for example, specifying the update target device 44 as the object to be reprogrammed (see below). Figure 2 Information about the data used for reprogramming, including the data used for updating the program.

[0042] In addition, the control device 22 includes the vehicle navigation system control unit 52a described later (see reference). Figure 2 Furthermore, the vehicle navigation system control unit 52a can display various information such as map information on the display unit 24 connected to the control device 22.

[0043] Figure 2 This is a block diagram showing the electrical system circuit controlled by the control device 22 of this embodiment. (Example) Figure 2As shown, the electrical system circuit installed in vehicle 1 includes a high-voltage system circuit 30, a low-voltage system circuit 40, and a DC-DC converter 60. The high-voltage system circuit 30 includes a high-voltage battery 32 and a high-voltage relay 34. The high-voltage relay 34 is a relay device in the high-voltage system circuit 30 that switches the electrical connection of the high-voltage battery 32 on and off.

[0044] Additionally, the low-voltage system circuit 40 includes a low-voltage battery 42, a replacement device 44, a replacement unit 46, and a vehicle load 48. The low-voltage battery 42 is a battery whose output voltage is lower than that of the high-voltage battery 32 and is capable of charging. The low-voltage battery 42 is, for example, a 12V auxiliary battery, supplying a lower voltage (e.g., 12V) DC power to various on-board devices (auxiliary devices) mounted in the vehicle 1. The replacement unit 46 is a program update tool that executes program updates (reprogramming) of the replacement device 44 based on instructions from the control device 22. The replacement unit 46 uses power supplied from either the low-voltage battery 42 or the high-voltage battery 32 to execute the reprogramming of the replacement device 44. It should be noted that the vehicle load 48 includes, for example, electrical loads such as a rearview mirror motor (not shown), a power window motor, and a radiator fan motor.

[0045] It should be noted that the device 44 to be updated specifically includes, for example, the engine control unit 10a that controls the engine 10, the motor control unit 12a that controls the motor 12, the high-voltage battery control unit 32a that controls the high-voltage battery 32, the high-voltage relay control unit 34a that controls the high-voltage relay 34, the low-voltage battery control unit 42a that controls the low-voltage battery 42, the wireless communication unit 50a that communicates with the wireless data transmission center 102 via the network 100, the vehicle navigation system control unit 52a that controls the vehicle navigation system, the IG power control unit 54a that controls the ignition power (IG power) of the vehicle 1 to be either IG-on (ready-on) or IG-off (ready-off) based on the user's operation, and the DC-DC converter control unit 60a that controls the operation of the DC-DC converter 60, etc.

[0046] Additionally, the DC-DC converter 60 is connected between the high-voltage system circuit 30 and the low-voltage system circuit 40. The DC-DC converter 60 can step down the output power of the high-voltage battery 32 of the high-voltage system circuit 30 and supply the stepped-down power to the low-voltage battery 42, the replacement device 44, the replacement unit 46, the vehicle load 48, etc. of the low-voltage system circuit 40.

[0047] The high-voltage battery control unit 32a sets the range of the target charge rate (SOC) of the high-voltage battery 32, namely the upper limit and the lower limit, and controls the high-voltage battery 32 to charge and discharge based on the range of the target charge rate.

[0048] Figure 3 This diagram illustrates the control of the target charging rate of the high-voltage battery 32 by the high-voltage battery control unit 32a. (See diagram for example.) Figure 3 As shown in (a), under normal execution without reprogramming, the high-voltage battery control unit 32a sets a normal SOC upper limit and a normal SOC lower limit as the range of the target charging rate. The normal SOC upper limit can be set, for example, to 90% when the high-voltage battery 32 is fully charged to 100%. Furthermore, the normal SOC lower limit can be set, for example, to 50% when the high-voltage battery 32 is fully charged to 100%. It should be noted that the specific values ​​of the normal SOC lower limit and SOC upper limit are not limited to specific examples of these values.

[0049] Furthermore, when the wireless communication unit 50a receives reprogramming information from the data transmission center 102 via the network 100 and schedules reprogramming, the high-voltage battery control unit 32a changes the lower limit of the target charge rate (SOC) of the high-voltage battery 32 to a value higher than the normal lower limit (the normal SOC lower limit) (the reprogramming schedule preparation value). On the other hand, regarding the upper limit of SOC, the high-voltage battery control unit 32a sets it to the normal upper limit of SOC.

[0050] In detail, when the wireless communication unit 50a receives reprogramming information from the data transmission center 102 via the network 100, the high-voltage battery control unit 32a determines that there is a reprogramming execution schedule. Furthermore, the high-voltage battery control unit 32a calculates the power required for reprogramming the target device 44 (hereinafter also referred to as "power required for reprogramming") based on the received reprogramming information.

[0051] Specifically, the reprogramming information includes various information such as the program capacity of the device to be updated 44, the write speed when writing the update program to the device to be updated 44, the power consumption per unit time during the reprogramming process, and the communication speed between the update unit 46 and the device to be updated 44. The high-voltage battery control unit 32a derives the power required for reprogramming based on all or part of this various information.

[0052] Furthermore, the high-voltage battery control unit 32a changes the lower limit of the target charge rate (SOC) of the high-voltage battery 32 to a higher reprogramming reservation preparation value than usual, based on the derived power required for reprogramming. For example, the high-voltage battery control unit 32a sets the lower limit of the target charge rate (SOC) of the high-voltage battery 32 to a higher reprogramming reservation preparation value (e.g., 70% of full charge) than usual (e.g., 50% of full charge). Preferably, the higher the derived power required for reprogramming, the higher the lower limit of the target charge rate (SOC) (reprogramming reservation preparation value) is set to. As a result, since the high-voltage battery 32 can be sufficiently charged to ensure a charge amount exceeding the power required for reprogramming, insufficient power during reprogramming can be prevented.

[0053] It should be noted that, in this embodiment, although the high-voltage battery control unit 32a is configured to derive the power required for reprogramming the target device 44 based on reprogramming information, and change the lower limit of the SOC of the target charge rate of the high-voltage battery 32 based on the derived power required for reprogramming, the present invention is not limited to this. For example, when the wireless communication unit 50a receives reprogramming information from the data transmission center 102 via the network 100 and schedules reprogramming, the high-voltage battery control unit 32a may set a predetermined lower limit of SOC as the lower limit of the SOC of the target charge rate of the high-voltage battery 32 (reprogramming reservation preparation value). For example, the lower limit of SOC as the reprogramming reservation preparation value may be preset to 70% when the high-voltage battery 32 is fully charged to 100%.

[0054] Alternatively, a portion of the reprogramming information may include required power information related to the power needed for reprogramming the target device 44. In this case, the high-voltage battery control unit 32a can change the lower limit of the target charge rate (SOC) of the high-voltage battery 32 based on the required power information.

[0055] Furthermore, after changing the SOC lower limit of the target charge rate of the high-voltage battery 32 to the reprogramming reservation preparation value, the high-voltage battery 32 is charged until it reaches a charge level higher than or equal to the reprogramming reservation preparation value. Next, when a reprogramming execution reservation is made, if the user performs a ready-to-off operation (IG-off operation) on the vehicle 1, the update unit 46 checks the charge levels of the low-voltage battery 42 and the high-voltage battery 32.

[0056] Figure 4This is a diagram illustrating the reprogramming execution license screen 24a of this embodiment. When the low-voltage battery 42 is charged to a level greater than or equal to the charge required for reprogramming the target device 44, and the reprogramming of the target device 44 can be performed using the low-voltage battery 42, or when the high-voltage battery 32 is charged to a level greater than or equal to the reprogramming reservation preparation value, such as... Figure 4 As shown, the vehicle navigation system control unit 52a displays a reprogramming execution permission screen 24a on the display unit 24, which requests the user's permission to perform reprogramming.

[0057] The reprogramming execution permission screen 24a displays a reminder text such as "If reprogramming is performed, vehicle 1 cannot be used until the reprogramming is completed," and a button image that allows the user to choose whether the reprogramming can be performed ("yes" or "no").

[0058] Furthermore, if the user presses the "Yes" button on the reprogramming execution license screen 24a to allow reprogramming, the reprogramming process will begin. On the other hand, if the user presses the "No" button on the reprogramming execution license screen 24a to refuse reprogramming, or if the user does not press either the "Yes" or "No" button on the reprogramming execution license screen 24a, the reprogramming process will not begin.

[0059] If reprogramming work begins, and if the reprogramming of the target device 44 can be performed using the low-voltage battery 42, the update unit 46 uses the power of the low-voltage battery 42 to perform the reprogramming of the target device 44.

[0060] On the other hand, if the low-voltage battery 42 is undercharged and reprogramming of the updated device 44 cannot be performed using the low-voltage battery 42, the high-voltage relay control unit 34a connects the high-voltage relay 34 to perform reprogramming using the high-voltage battery 32, enabling the output of power from the high-voltage battery 32 to the DC-DC converter 60. Furthermore, the DC-DC converter control unit 60a starts the operation of the DC-DC converter 60, stepping down the output power from the high-voltage battery 32 and supplying the stepped-down power to the low-voltage system circuit 40.

[0061] At this time, the update unit 46 determines whether the update target device 44, which is the target of reprogramming, is a specific device required for the power supply from the high-voltage battery 32. This specific device may be, for example, the high-voltage battery control unit 32a, the DC-DC converter control unit 60a, or the high-voltage relay control unit 34a.

[0062] Furthermore, if the device 44 to be reprogrammed is not a specific device required for power supply from the high-voltage battery 32, the reprogramming unit 46 uses the power supplied from the high-voltage battery 32 to the low-voltage system circuit 40 to reprogram the device 44. Once the reprogramming is complete, the DC-DC converter control unit 60a terminates the operation of the DC-DC converter 60, and the high-voltage relay control unit 34a disconnects the high-voltage relay 34.

[0063] On the other hand, if the update target device 44, which is the object of reprogramming, is a specific device required for the power supply from the high-voltage battery 32, power cannot be supplied from the high-voltage battery 32 to the low-voltage system circuit 40, and the reprogramming of the update target device 44 cannot be performed by the update unit 46. Therefore, in this embodiment, the low-voltage battery 42 is temporarily charged by supplying power from the high-voltage battery 32 to the low-voltage battery 42 via the DC-DC converter 60 using the update target device 44 (specific device). After the charging of the low-voltage battery 42 is completed, the power supply from the high-voltage battery 32 is stopped, and after the operation of the update target device 44 (specific device) is finished, the power from the low-voltage battery 42 is used to perform the reprogramming of the update target device 44 (specific device).

[0064] Specifically, the low-voltage battery control unit 42a charges the low-voltage battery 42 before the low-voltage battery 42 reaches a level sufficient to perform reprogramming of the target device 44. At this time, the low-voltage battery control unit 42a can determine the charge level of the low-voltage battery 42 based on the power required for reprogramming the target device 44 derived from the high-voltage battery control unit 32a. It should be noted that this is not a limited example; the low-voltage battery control unit 42a may charge the low-voltage battery 42 until the charge level reaches a predetermined amount. For example, this predetermined charge level may be preset to 90% when the low-voltage battery 42 is fully charged to 100%.

[0065] Furthermore, once the low-voltage battery 42 has finished charging, the DC-DC converter control unit 60a terminates the operation of the DC-DC converter 60, and the high-voltage relay control unit 34a disconnects the high-voltage relay 34. Afterwards, the update unit 46 uses the power from the fully charged low-voltage battery 42 to reprogram the update target device 44.

[0066] (Control methods)

[0067] Figure 5This is a flowchart illustrating the control process for reprogramming vehicle 1 in this embodiment.

[0068] like Figure 5 As shown, firstly, the IG power control unit 54a of the control device 22 sets the IG power to on based on the user's operation and controls the vehicle 1 to the ready-start (IG-on) state (S101).

[0069] Next, the control device 22 wirelessly communicates with the data transmission center 102 via the wireless communication unit 50a, thereby confirming whether there is any reprogramming data that the vehicle 1 has not received in the reprogramming data transmitted from the data transmission center 102 (S103). Here, the reprogramming data is data containing update data for updating the program related to the target device 44. When it is necessary to update the reprogramming program of the target device 44, the data transmission center 102 transmits reprogramming information containing reprogramming data for executing the reprogramming program to each vehicle 1 via the network 100.

[0070] If the determination in S103 indicates that there is no unreceived reprogramming data (No in step S103), the high-voltage battery control unit 32a of the control device 22 determines whether the reprogramming reception completion flag is on (step S105). If the reprogramming reception completion flag is on, it means that although the vehicle 1 has completed the reception of reprogramming data, since reprogramming has not been performed with the reprogramming data, it is in a state where the reprogramming needs to be performed (scheduled reprogramming state).

[0071] If the determination result in S105 is that the reprogramming reception completion flag is off (No in step S105), since reprogramming is not required, the high-voltage battery control unit 32a sets the lower and upper limits of the SOC of the high-voltage battery 32 to normal values ​​(step S107). As a result, during subsequent driving of the vehicle 1, the high-voltage battery 32 is charged within the normal target charging rate range (see reference). Figure 3 (a)

[0072] Furthermore, the IG power control unit 54a of the control device 22 controls the vehicle 1 to prepare for shutdown (IG-off) (step S109) based on the user's operation and ends the control process.

[0073] On the other hand, if the result of the determination in S105 is that the reprogramming data reception completion flag is enabled ("Yes" in step S105), proceed to S117 as described later.

[0074] In addition, if the result of the determination in S103 is that there is unreceived reprogramming data and it is necessary to receive reprogramming data from the data transmission center 102 ("Yes" in step S103), the control device 22 receives reprogramming information containing reprogramming data from the data transmission center 102 through the network 100 and the wireless communication unit 50a (step S111).

[0075] Next, the high-voltage battery control unit 32a of the control device 22 extracts the power required for reprogramming the target device 44 based on the reprogramming information received from the data transmission center 102 (step S113), and sets the reprogramming data reception completion flag to "on" (step S115). That is, if the wireless communication unit 50a receives reprogramming data, the reprogramming data reception completion flag is turned on, and reprogramming is scheduled. It should be noted that the reprogramming data reception completion flag will not be turned off until the reprogramming process ends.

[0076] Furthermore, if the reprogramming data reception completion flag is determined to be enabled in step S105 ("Yes" in step S105) and the reprogramming data reception completion flag is enabled in step S113, the high-voltage battery control unit 32a of the control device 22 determines that reprogramming has been scheduled, and changes the lower limit of the target charge rate (SOC) of the high-voltage battery 32 to a higher reprogramming schedule preparation value based on the power required for reprogramming the derived update target device 44, and sets the upper limit of the SOC to the normal value (step S117). As a result, during subsequent driving of the vehicle 1, the high-voltage battery 32 is charged within the specific target charge rate range at the time of reprogramming (see step S117). Figure 3 (b)

[0077] Subsequently, when vehicle 1 has stopped, the IG power control unit 54a of control device 22 controls vehicle 1 to prepare for shutdown (IG-off) based on the user's operation (step S119).

[0078] Next, the control device 22 confirms the charge level of the low-voltage battery 42 and determines whether the charge level of the low-voltage battery 42 is above the charge level required for the reprogramming of the target device 44, that is, whether the reprogramming can be performed by relying on the low-voltage battery 42 (step S121).

[0079] As a result, if reprogramming cannot be performed using the low-voltage battery 42 (No in step S121), the control device 22 confirms the charge level of the high-voltage battery 32 and determines whether the charge level (actual SOC) of the high-voltage battery 32 is above the reprogramming reservation preparation value (the lower limit of SOC for the target charge rate) (step S123).

[0080] As a result, when the charge level of the high-voltage battery 32 is above the reprogramming reservation preparation value ("Yes" in step S123) and when reprogramming can be performed using the low-voltage battery 42 ("Yes" in step S121), the vehicle navigation system control unit 52a of the control device 22 displays the reprogramming execution permission screen 24a on the display unit 24 (see reference). Figure 4 (Step S125).

[0081] Next, the control device 22 determines whether the user has pressed the "Yes" button on the reprogramming execution permission screen 24a (step S127). If the user has pressed the "Yes" button on the reprogramming execution permission screen 24a to allow reprogramming ("Yes" in step S127), the control device 22 uses the update unit 46 to perform reprogramming work control processing (step S200). The reprogramming work control processing (step S200) will be described later. If the reprogramming work control processing (step S200) ends, the control device 22 disables the reprogramming data reception completion flag and terminates the process.

[0082] On the other hand, if the "No" button on the reprogramming execution license screen 24a in S127 is operated, or if the user does not operate either the "Yes" or "No" button on the reprogramming execution license screen 24a (step S127), the control device 22 will not execute the reprogramming operation and will end the process. Additionally, if the charge level of the high-voltage battery 32 is lower than the reprogramming reservation preparation value in S123 (step S123, "No"), the control device 22 will also not execute the reprogramming operation and will end the process.

[0083] (Reprogramming job control processing)

[0084] Figure 6 This is used to explain the above-described reprogramming operation control process of vehicle 1 in this embodiment. Figure 5 The flowchart of step S200).

[0085] like Figure 6 As shown, firstly, the control device 22 confirms the charge level of the low-voltage battery 42 and determines whether the charge level of the low-voltage battery 42 is above the charge level required for the reprogramming of the target device 44, that is, whether the reprogramming can be performed by relying on the low-voltage battery 42 (step S201).

[0086] As a result, if reprogramming cannot be performed using the low-voltage battery 42 (No in step S201), the high-voltage relay control unit 34a of the control device 22 connects to the high-voltage relay 34 (step S203), and the DC-DC converter control unit 60a starts operating the DC-DC converter 60, stepping down the output power from the high-voltage battery 32 and supplying the stepped-down power to the low-voltage system circuit 40 (step S205). As a result, the low-voltage battery 42 can be charged using the power supplied from the high-voltage battery 32. Furthermore, in the low-voltage system circuit 40, the power supplied from the high-voltage battery 32 can be used to perform reprogramming of the target device 44.

[0087] Next, the control device 22 determines whether the update target device 44, which is the target of reprogramming, is a specific device required for the power supply from the high-voltage battery 32 (step S207). Specifically, the specific device is, for example, the high-voltage battery control unit 32a or the DC-DC converter control unit 60a as described above.

[0088] As a result, if the device 44 to be reprogrammed is not the specific device required for power supply from the high-voltage battery 32, the control device 22 instructs the update unit 46 to perform reprogramming. The update unit 46 uses power from the high-voltage battery 32 to begin reprogramming the device 44 (step S209). Afterwards, if the reprogramming execution is completed ("Yes" in step S211), the DC-DC converter control unit 60a terminates the operation of the DC-DC converter 60 (step S213), and the high-voltage relay control unit 34a disconnects the high-voltage relay 34 (step S215), ending the process.

[0089] On the other hand, if the update target device 44, which is the object of reprogramming, is a specific device required for the power supply from the high-voltage battery 32 ("Yes" in step S207), the low-voltage battery control unit 42a of the control device 22 determines whether the low-voltage battery 42 has been charged using the output power of the high-voltage battery 32 (step S217). Specifically, it determines whether the amount of charge on the low-voltage battery 42 is above the amount of charge determined based on the power required for reprogramming the update target device 44 derived by the high-voltage battery control unit 32a.

[0090] As a result, when the charging of the low-voltage battery 42 is completed ("Yes" in step S217), the DC-DC converter control unit 60a of the control device 22 ends the operation of the DC-DC converter 60 (step S219), and the high-voltage relay control unit 34a disconnects the connection of the high-voltage relay 34 (step S221).

[0091] Furthermore, if the connection of the high-voltage relay 34 is disconnected in step S221, and if it is determined in step S201 that reprogramming can be performed using the low-voltage battery 42 ("Yes" in step S201), the control device 22 instructs the update unit 46 to perform reprogramming, and the update unit 46 uses the power of the low-voltage battery 42 to perform reprogramming of the update target device 44 (step S223). If the reprogramming is completed ("Yes" in step S225), the process ends.

[0092] As explained above, in this embodiment, if reprogramming data is received, the lower limit of the SOC is changed to a higher value than usual. This suppresses the possibility of reprogramming interruption due to insufficient residual power in the high-voltage battery 32 or the low-voltage battery 42 during reprogramming. This effect will be detailed below.

[0093] In conventional technology, the power required for reprogramming is typically provided by a low-voltage battery 42. However, when the state of charge (SOC) of the low-voltage battery 42 decreases, there may be insufficient power to perform the reprogramming. If the reprogramming is interrupted due to insufficient power, it will adversely affect the normal operation of the vehicle 1, and depending on the circumstances, it may be necessary to replace the update object device 44 itself, which is the object to be reprogrammed.

[0094] On the other hand, when reprogramming is performed based on reprogramming data received via wireless communication, if vehicle 1 is wired to an external power source, it is not preferable to supply power from an external power source during reprogramming because it would hinder convenience.

[0095] Therefore, in electric vehicles (HEVs, EVs) equipped with a high-voltage battery 32 for motor drive, when the power required for reprogramming of the low-voltage battery 42 is insufficient, it is considered to effectively use the output voltage of the high-voltage battery 32 for reprogramming. However, if the state of charge (SOC) of the high-voltage battery 32 decreases when reprogramming begins, reprogramming cannot be performed. In particular, this problem is prone to occur in parallel hybrid systems where the high-voltage battery 32 cannot be charged while the vehicle is parked.

[0096] Therefore, in this embodiment, as described above, when a reprogramming reservation for the target device 44 is made, the control device 22 changes the lower limit of the SOC of the target charge rate of the high-voltage battery 32 to a value higher than the normal lower limit (the normal SOC lower limit) (the reprogramming reservation preparation value). As a result, since the charge level of the high-voltage battery 32 can be made sufficient for reprogramming, the situation where reprogramming is interrupted due to insufficient power can be suppressed.

[0097] Furthermore, as described above, when reprogramming data for the target device 44 is received via the wireless communication unit 50a, the control device 22 determines that a reprogramming reservation for the target device 44 has been made. This allows for a rapid change in the lower limit of the target charge rate (SOC) of the high-voltage battery 32 towards a reprogramming reservation preparation value. Therefore, after a reprogramming reservation is made, when the control is set to IG-off, the high-voltage battery 32 is essentially fully charged.

[0098] Furthermore, as described above, when reprogramming data is received via the wireless communication unit 50a, the control device 22 calculates the power required for reprogramming the target device 44 based on the reprogramming data, and changes the lower limit of the target charging rate of the high-voltage battery 32 based on the calculated power. Therefore, since the high-voltage battery 32 can be adequately charged to ensure a charge level exceeding the power required for reprogramming, insufficient power during reprogramming can be suppressed.

[0099] As described above, in the parallel hybrid mode, the high-voltage battery 32 cannot be charged during parking. Since, as in this embodiment, by changing the lower limit of the target charge rate of the high-voltage battery 32 to the reprogramming reservation preparation value based on the reprogramming reservation, the situation where reprogramming is interrupted due to insufficient power can be suppressed, the technology of this embodiment is particularly effective in the parallel hybrid mode.

[0100] While preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to these embodiments. It should be understood that, if one is skilled in the art, various modifications or alterations will be apparent within the scope of the claims, and such modifications or alterations are naturally also within the technical scope of the present invention.

[0101] It should be noted that although the above embodiment is designed to start reprogramming immediately upon user permission, the present invention is not limited to this. For example, even when the user allows reprogramming, the user can arbitrarily specify the actual time for reprogramming. In this case, if the user-defined time is reached, the update unit 46 starts reprogramming. It should also be noted that if, upon reaching the user-defined time, reprogramming cannot be performed while the vehicle 1 is in motion, the reprogramming permission screen 24a can be displayed again after the vehicle 1 stops to request the user's permission for reprogramming.

[0102] Furthermore, in the above embodiment, when reprogramming is scheduled upon receiving reprogramming information, the high-voltage battery control unit 32a changes the lower limit of the target charge rate (SOC) of the high-voltage battery 32 to a higher value than usual (reprogramming schedule preparation value), while the upper limit of the SOC is set to a normal value. However, the present invention is not limited to this example; the upper limit of the target charge rate (SOC) of the high-voltage battery 32 may also be changed to a higher value than usual, and the lower limit of the target charge rate (SOC) of the high-voltage battery 32 may also be changed to a higher value than usual (reprogramming schedule preparation value).

[0103] Furthermore, although the above embodiments describe the case where vehicle 1 is a parallel hybrid powertrain, the present invention is not limited thereto. The present invention can be applied to various types of vehicles, including electric vehicles (EVs), plug-in hybrid electric vehicles (PHEVs), and non-plug-in hybrid electric vehicles (hybrid vehicles).

[0104] Industrial applicability: This invention can be used in vehicles.

Claims

1. A vehicle characterized by comprising: Possessing: a high-voltage system circuit including a high-voltage battery; a low-voltage system circuit including a low-voltage battery whose output voltage is lower than that of the high-voltage battery, and an update unit that performs updating of a program of a device to be updated using electric power supplied from the low-voltage battery or the high-voltage battery; a DC-DC converter connected between the high-voltage system circuit and the low-voltage system circuit and capable of stepping down the output electric power of the high-voltage battery to supply it to the update unit of the low-voltage system circuit; and a control unit that sets a range of a target state of charge of the high-voltage battery and controls charging of the high-voltage battery based on the range of the target state of charge, when updating of the program of the device to be updated is scheduled, the control unit changes a lower limit value of the target state of charge of the high-voltage battery to a value higher than that at ordinary times, the update unit, in a case where electric power for performing updating of the program of the device to be updated is insufficient in the low-voltage battery, determines whether the device to be updated is a specific device for which supply of electric power from the high-voltage battery is required, in a case where the device to be updated is not the specific device, performs updating of the program of the device to be updated using electric power supplied from the high-voltage battery to the low-voltage system circuit, in a case where the device to be updated is the specific device, ends operation of the device to be updated after charging of the low-voltage battery using the device to be updated to supply electric power from the high-voltage battery to the low-voltage battery via the DC-DC converter, and then performs updating of the program of the device to be updated using electric power of the low-voltage battery.

2. The vehicle according to claim 1, characterized in that the vehicle is provided with a wireless communication unit that performs wireless communication with an external device, when update data for updating the program of the device to be updated is received by the wireless communication unit, the control unit determines that updating of the program of the device to be updated is scheduled, the update unit performs updating of the program of the device to be updated based on the update data.

3. The vehicle according to claim 2, characterized in that when the update data is received by the wireless communication unit, the control unit derives electric power required for updating of the program of the device to be updated based on information related to the update data, and changes the lower limit value of the target state of charge of the high-voltage battery based on the derived electric power.

4. The vehicle according to any one of claims 1 to 3, characterized by Possessing: an engine as a travel drive source; and a motor connected to the high-voltage battery and serving as a travel drive source.

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