Battery Pack Monitoring Device

Abstract

To monitor a battery pack.SOLUTION: This battery pack monitoring device comprises: a battery pack which is mounted to a vehicle, with a battery accommodated in the inside of it; a first wireless communication unit which is provided in the inside of the battery pack and capable of wireless communication; a second wireless communication unit which is provided to the outside of the battery pack in the vehicle and is capable of wireless communication; and a control device. The control device includes one or a plurality of processors and one or a plurality of memories connected to the processor(s). The processor(s) execute the processes of: attempting wireless communication between the first and the second wireless communication units; and estimating the presence of damage to the battery pack on the basis of the establishment state of wireless communication between the first and the second wireless communication units.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a battery pack monitoring device that monitors a battery pack. [Background technology]

[0002] For example, Patent Document 1 discloses a battery system in which a battery, a monitoring unit, and a management unit are housed in a battery pack. In this battery system, the monitoring unit acquires battery information such as the battery voltage, and the acquired battery information is wirelessly transmitted to the management unit within the battery pack. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Re-tabled publication 2014 / 103008 Summary of the Invention [Problem to be solved by the invention]

[0004] The battery pack is sealed with a metal member to protect the battery inside the battery pack from short circuits caused by external impacts or water intrusion, etc. If such a battery pack is damaged, its function of protecting the battery is reduced.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a battery pack monitoring device capable of monitoring a battery pack. [Means for solving the problem]

[0006] In order to solve the above problem, a battery pack monitoring device according to one embodiment of the present invention comprises: a battery pack mounted on the vehicle and housing a battery therein; a first wireless communication unit provided inside the battery pack and capable of wireless communication; a second wireless communication unit that is provided outside the battery pack in the vehicle and is capable of wireless communication; a control device; Equipped with The control device one or more processors; one or more memories coupled to said processor; and The processor: Attempting wireless communication between the first wireless communication unit and the second wireless communication unit; estimating whether or not the battery pack is damaged based on an establishment state of wireless communication between the first wireless communication unit and the second wireless communication unit; Execute the process including. [Effects of the Invention]

[0007] According to the present invention, it is possible to monitor the battery pack. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic side view showing the configuration of a vehicle to which a battery pack monitoring device according to a first embodiment is applied. [Figure 2] FIG. 2 is a schematic plan view showing the configuration of a vehicle to which the battery pack monitoring device according to the first embodiment is applied. [Figure 3] FIG. 3 is a block diagram showing the configurations of the vehicle control device, the management unit, and the monitoring unit. [Figure 4] FIG. 4 is a flowchart showing an example of the flow of operations of the management control unit in the management unit. [Figure 5] FIG. 5 is a flowchart illustrating the flow of the wireless communication trial process. [Figure 6] FIG. 6 is a flowchart illustrating the flow of the determination execution process. [Figure 7]FIG. 7 is a schematic plan view showing the configuration of a vehicle to which a battery pack monitoring device according to the second embodiment is applied. [Figure 8] FIG. 8 is a diagram illustrating the flow of wireless communication trial processing in the second embodiment. [Figure 9] FIG. 9 is a flowchart illustrating the flow of the determination execution process in the second embodiment. [Figure 10] FIG. 10 is a schematic plan view showing the configuration of a vehicle to which a battery pack monitoring device according to the third embodiment is applied. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Specific dimensions, materials, numerical values, etc. shown in the embodiments are merely examples for facilitating understanding of the invention and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown.

[0010] (First embodiment) FIG. 1 is a schematic side view showing the configuration of a vehicle 1 to which a battery pack monitoring device 10 according to the first embodiment is applied. FIG. 2 is a schematic plan view showing the configuration of a vehicle 1 to which a battery pack monitoring device 10 according to the first embodiment is applied. In FIG. 1, arrows indicate up, down, front, and rear with respect to the vehicle 1. In FIG. 2, arrows indicate left, right, front, and rear with respect to the vehicle 1. In the following, elements related to the battery pack monitoring device 10 in the vehicle 1 will be described, and descriptions of other elements in the vehicle 1 will be omitted.

[0011] As shown in Fig. 2, vehicle 1 includes battery module 20a, battery module 20b, battery module 20c, and battery module 20d. Hereinafter, battery module 20a, battery module 20b, battery module 20c, and battery module 20d may be collectively referred to as battery modules 20. In the example of Fig. 2, vehicle 1 is equipped with four battery modules 20, but the number of battery modules 20 equipped in vehicle 1 is not limited to four, and may be one, two, three, five or more.

[0012] Battery module 20a has a battery 22a and a monitoring unit 24a. Battery module 20b has a battery 22b and a monitoring unit 24b. Battery module 20c has a battery 22c and a monitoring unit 24c. Battery module 20d has a battery 22d and a monitoring unit 24d. Hereinafter, batteries 22a, 22b, 22c, and 22d may be collectively referred to as batteries 22. Furthermore, monitoring units 24a, 24b, 24c, and 24d may be collectively referred to as monitoring units 24. In this way, each battery module 20 has a battery 22 and a monitoring unit 24.

[0013] The battery 22 is, for example, a lithium-ion battery or other secondary battery that can be charged and discharged. The battery 22 is, for example, a battery pack configured by connecting a plurality of cells in series. Although not shown, the vehicle 1 is equipped with a motor as a driving source for traveling. The battery 22 supplies power to the motor. The vehicle 1 is an electric vehicle or a hybrid electric vehicle that has such a battery 22.

[0014] The monitoring units 24 monitor the states of the batteries 22 that belong to the same battery module 20 as the battery module 20 to which the monitoring unit 24 belongs, i.e., the batteries 22 that correspond to the monitoring units 24. For example, the monitoring unit 24a sequentially measures the voltage and temperature of the battery 22a. The monitoring unit 24b sequentially measures the voltage and temperature of the battery 22b. The monitoring unit 24c sequentially measures the voltage and temperature of the battery 22c. The monitoring unit 24d sequentially measures the voltage and temperature of the battery 22d.

[0015] In addition to the battery module 20, the vehicle 1 also includes a battery pack 26, a management unit 28, and a vehicle control device 30. The battery pack 26 is formed from a metal material in the shape of a hollow box and is sealed. The battery module 20 and the management unit 28 are housed inside the battery pack 26. In other words, the battery 22 is housed inside the battery pack 26. The battery pack 26 protects the battery 22 inside the battery pack 26 from short circuits caused by external impacts or water intrusion.

[0016] The management unit 28 manages each battery module 20. The management unit 28 and the monitoring unit 24 have a wireless communication function. For example, the management unit 28 can establish wireless communication with the monitoring unit 24 in the battery pack 26. The monitoring unit 24 transmits battery information including the measured voltage and temperature of the battery 22 to the management unit 28 via wireless communication. The management unit 28 receives the battery information transmitted from the monitoring unit 24 via wireless communication for each monitoring unit 24. The management unit 28 may also derive the SOC (State Of Charge) of the battery 22 based on the voltage of the battery 22 acquired from the monitoring unit 24.

[0017] The vehicle control device 30 controls the entire vehicle 1, for example, by controlling the driving of the vehicle 1. The vehicle control device 30 is provided outside the battery pack 26. The management unit 28 is connected to the vehicle control device 30 via a wired communication network such as a Controller Area Network (CAN). The management unit 28 transmits battery information acquired from the monitoring unit 24 to the vehicle control device 30 via wired communication. The vehicle control device 30 may reflect the battery information acquired from the management unit 28 in the driving control of the vehicle 1, etc.

[0018] As shown in FIG. 1, the battery pack 26 is disposed, for example, in the center of the lower part of the body of the vehicle 1. Furthermore, as shown in FIG. 2, the battery modules 20 are disposed in the internal space of the battery pack 26, dispersed in the horizontal direction of the battery pack 26. For example, the battery module 20a is disposed near the front left of the battery pack 26. The battery module 20b is disposed near the front right of the battery pack 26. The battery module 20c is disposed near the rear left of the battery pack 26. The battery module 20d is disposed near the rear right of the battery pack 26.

[0019] The vehicle 1 is equipped with a rearview camera 32, a tire pressure sensor 34a, a tire pressure sensor 34b, a tire pressure sensor 34c, and a tire pressure sensor 34d. The vehicle control device 30 also has a wireless communication function.

[0020] The rearview camera 32 is installed, for example, in the vehicle interior, in the rear center of the roof, near the rear window. The rearview camera 32 can capture images of the outside behind the vehicle 1 through the rear window. The rearview camera 32 has a wireless communication function. The rearview camera 32 transmits the captured images to the vehicle control device 30 via wireless communication. The vehicle control device 30 may display the captured images of the rearview camera 32 on, for example, a display of a navigation device (not shown).

[0021] Tire pressure sensor 34a is installed on the left front wheel. Tire pressure sensor 34b is installed on the right front wheel. Tire pressure sensor 34c is installed on the left rear wheel. Tire pressure sensor 34d is installed on the right rear wheel. Hereinafter, tire pressure sensors 34a, 34b, 34c, and 34d may be collectively referred to as tire pressure sensors 34. In the example of FIG. 2, tire pressure sensors 34 are installed on all wheels of vehicle 1. However, tire pressure sensors 34 are not limited to being installed on all wheels of vehicle 1, and may be installed on at least one or more wheels.

[0022] The tire pressure sensor 34 measures the air pressure of the tire on the wheel on which the tire pressure sensor 34 is installed. The tire pressure sensor 34 has a wireless communication function. The tire pressure sensor 34 transmits the measured tire pressure to the vehicle control device 30 via wireless communication. For example, if the received tire pressure is lower than a predetermined pressure, the vehicle control device 30 may display an alarm indicating that the tire pressure is low on the instrument panel or the like.

[0023] As described above, the battery pack 26 is sealed with a metal member to protect the battery 22 in the battery pack 26 from short circuits caused by external impacts or water intrusion. If the exterior surface of the battery pack 26 is damaged, the function of protecting the battery 22 is reduced.

[0024] Therefore, a battery pack monitoring device 10 is applied to the vehicle 1 according to the first embodiment. The battery pack monitoring device 10 includes a first wireless communication unit that is provided inside the battery pack 26 and is capable of wireless communication, and a second wireless communication unit that is provided outside the battery pack 26 in the vehicle 1 and is also capable of wireless communication.

[0025] The first wireless communication unit is, for example, the management unit 28 housed in the battery pack 26, and more specifically, a management communication unit 70 (described later) in the management unit 28. The second wireless communication unit is, for example, the rearview camera 32 and the tire pressure sensor 34 disposed outside the battery pack 26.

[0026] In the battery pack monitoring device 10, wireless communication is attempted between the first wireless communication unit and the second wireless communication unit. In Fig. 2, an attempt at wireless communication between the management communication unit 70 of the management unit 28 and the rearview camera 32, and an attempt at wireless communication between the management communication unit 70 of the management unit 28 and the tire pressure sensor 34 are indicated by indicators such as ripple marks.

[0027] As described above, the battery pack 26 is normally sealed with a metal member. This shields the management unit 28, which is an example of a first wireless communication unit, from the rearview camera 32 and the tire pressure sensor 34, which are examples of a second wireless communication unit. As a result, even if wireless communication is attempted between the first wireless communication unit and the second wireless communication unit, the wireless communication cannot be established. In other words, the normal state is one in which wireless communication is not established between the first wireless communication unit and the second wireless communication unit.

[0028] However, if damage such as a crack or a hole occurs in the battery pack 26, radio waves can propagate through the damaged portion from the inside to the outside of the battery pack 26, or from the outside to the inside of the battery pack 26. In other words, if damage occurs to the battery pack 26, when wireless communication is attempted between the first wireless communication unit and the second wireless communication unit, the wireless communication will be established.

[0029] Therefore, in the battery pack monitoring device 10 of this embodiment, whether or not the battery pack 26 is damaged is estimated based on the establishment state of wireless communication between the first wireless communication unit and the second wireless communication unit.

[0030] Here, the establishment status of wireless communication basically means whether or not wireless communication is established, i.e., whether or not wireless communication is successful. However, taking into consideration a situation in which wireless communication is established by chance, the establishment status of wireless communication may be defined based on whether or not the number of times wireless communication is established is a predetermined number or more within a predetermined period. Here, the predetermined number is set to an arbitrary number, such as five times, that is sufficient to distinguish between wireless communication established due to damage to the battery pack 26 and a situation in which wireless communication is established by chance. The predetermined period is set to, for example, one driving cycle, but may also be set to an arbitrary period.

[0031] For example, if wireless communication is established a predetermined number of times or more within a predetermined period, it may be assumed that wireless communication is substantially established, and it may be estimated that there is damage to battery pack 26. On the other hand, even if wireless communication is established once within a predetermined period, if the number of times that wireless communication is established is less than a predetermined number, it may be assumed that wireless communication is not substantially established, and it may be estimated that there is no damage to battery pack 26. In other words, it may be estimated whether or not there is damage to battery pack 26 based on the substantial success or failure of wireless communication, not based on the sudden success or failure of wireless communication.

[0032] Furthermore, a short-range wireless communication standard such as Bluetooth can be adopted for wireless communication between the first wireless communication unit and the second wireless communication unit. Such a short-range wireless communication standard uses radio waves in the 2.4 GHz frequency band, for example. Because the wavelength of such radio waves is approximately 10 cm, if the battery pack 26 has damage such as a crack or a hole, the radio waves are likely to propagate between the inside and outside of the battery pack 26 through the damaged portion. Therefore, it is possible to appropriately estimate whether the battery pack 26 is damaged.

[0033] Fig. 3 is a block diagram showing the configurations of the vehicle control device 30, the management unit 28, and the monitoring unit 24. In Fig. 3, solid arrows indicate wired communication, and dashed arrows indicate wireless communication.

[0034] The vehicle control device 30 has a vehicle communication unit 40, one or more processors 42, one or more memories 44 connected to the processor 42, and a vehicle storage device 46. The vehicle communication unit 40 is capable of wired communication with the management unit 28. The processor 42 includes a ROM in which programs and the like are stored, and a RAM as a work area. The processor 42 works in cooperation with the programs stored in the memory to function as a vehicle control unit 48 and control the entire vehicle 1.

[0035] Vehicle storage device 46 is configured with a non-volatile storage element. Vehicle storage device 46 stores, for example, rearview camera identification information that identifies rearview camera 32 and tire pressure sensor identification information that identifies each tire pressure sensor 34. The rearview camera identification information may be any information that can identify rearview camera 32 and may be, for example, the MAC address of rearview camera 32. The tire pressure sensor identification information may be any information that can identify a tire pressure sensor and may be, for example, the MAC address of each tire pressure sensor 34. Vehicle control unit 48 can establish wireless communication with rearview camera 32 based on the rearview camera identification information. Vehicle control unit 48 can establish wireless communication with each tire pressure sensor 34 based on each tire pressure sensor identification information.

[0036] The monitoring unit 24 has a monitoring communication unit 50, one or more processors 52, one or more memories 54 connected to the processors 52, a voltage sensor 56, and a temperature sensor 58. The monitoring communication unit 50 can communicate wirelessly with the management unit 28. The processor 52 includes a ROM in which programs and the like are stored, and a RAM as a work area. The processor 52 works in cooperation with the programs stored in the memory 54 to function as a monitoring control unit 60. The monitoring control unit 60 executes processing to monitor the battery module 20 corresponding to the monitoring control unit 60.

[0037] The voltage sensor 56 measures the voltage of the battery 22 corresponding to the monitoring unit 24 to which the voltage sensor 56 belongs. The temperature sensor 58 measures the temperature of the battery 22 corresponding to the monitoring unit 24 to which the temperature sensor 58 belongs. The monitoring control unit 60 transmits battery information including the measured voltage and temperature of the battery 22 to the management unit 28 via the monitoring communication unit 50 by wireless communication.

[0038] The management unit 28 has a management communication unit 70, one or more processors 72, one or more memories 74 connected to the processors 72, and a management storage device 76. The management communication unit 70 is capable of wired communication with the vehicle control device 30. The management communication unit 70 is also capable of wireless communication with the monitoring unit 24. The management communication unit 70 is also capable of attempting wireless communication with the rearview camera 32 and also capable of attempting wireless communication with the tire pressure sensors 34.

[0039] The processor 72 includes a ROM in which programs and the like are stored, and a RAM as a work area. The processor 72 works in cooperation with a program stored in the memory 74 to function as a management control unit 80. The management control unit 80 executes processes related to the management of each battery module 20. For example, the management control unit 80 acquires battery information from the monitoring unit 24 via the management communication unit 70. The management control unit 80 transmits the acquired battery information to the vehicle control device 30 via the management communication unit 70.

[0040] The management control unit 80 also attempts wireless communication with the rearview camera 32 via the management communication unit 70. The management control unit 80 also attempts wireless communication with the tire pressure sensor 34 via the management communication unit 70. The management control unit 80 then estimates whether or not the battery pack 26 is damaged and the location of the damage, based on the status of establishment of wireless communication with the rearview camera 32 and the status of establishment of wireless communication with the tire pressure sensor 34.

[0041] The management storage device 76 is composed of a non-volatile storage element. Monitoring unit identification information that identifies each monitoring unit 24 is stored in the management storage device 76. The management control unit 80 can establish wireless communication with each monitoring unit 24 based on the monitoring unit identification information. The management storage device 76 also stores rearview camera identification information and each tire pressure sensor identification information.

[0042] The management control unit 80 attempts wireless communication with the rearview camera 32 based on the rearview camera identification information stored in the management storage device 76.

[0043] For example, management control unit 80 transmits request information requesting a response from rearview camera 32 to the MAC address of rearview camera 32. If battery pack 26 is damaged, the request information transmitted from management control unit 80 is transmitted to rearview camera 32. Rearview camera 32 can receive the request information transmitted from management control unit 80 while performing its original function. If the destination of the received request information is the MAC address of rearview camera 32, rearview camera 32 transmits response information including the MAC address of its own device to the sender of the received request information.

[0044] When management control unit 80 receives response information transmitted from rearview camera 32, it establishes wireless communication with rearview camera 32. On the other hand, if battery pack 26 is not damaged, the information transmitted from management control unit 80 will not reach rearview camera 32, and no response information will be transmitted from rearview camera 32. If management control unit 80 does not receive response information from rearview camera 32 even after a predetermined time has elapsed since management control unit 80 transmitted request information, wireless communication between management unit 28 and rearview camera 32 will not be established.

[0045] The management control unit 80 attempts wireless communication with each tire pressure sensor 34 based on the tire pressure sensor identification information stored in the management storage device 76. The sequence for attempting wireless communication with the tire pressure sensors 34 is generally the same as the sequence for attempting wireless communication with the rearview camera 32.

[0046] For example, the management control unit 80 transmits request information to the tire pressure sensor 34 with which it is attempting wireless communication, addressed to the MAC address of the tire pressure sensor 34. If the destination of the request information transmitted from the management control unit 80 is the MAC address of the tire pressure sensor 34, the tire pressure sensor 34 transmits response information including the MAC address of the tire pressure sensor 34 to the sender of the received request information.

[0047] When the management control unit 80 receives response information transmitted from a tire pressure sensor 34, it establishes wireless communication with the tire pressure sensor 34. On the other hand, if the management control unit 80 does not receive response information from a tire pressure sensor 34 even after a predetermined time has elapsed since the management control unit 80 transmitted request information, wireless communication between the management unit 28 and the tire pressure sensor 34 will not be established.

[0048] Furthermore, rearview camera 32 and tire pressure sensor 34, which are examples of second wireless communication units, are provided at multiple locations. Management control unit 80 estimates the location of damage in battery pack 26 based on the location of the second wireless communication unit with which wireless communication has been established.

[0049] For example, if wireless communication is substantially established with the rearview camera 32 located above the battery pack 26, the management control unit 80 determines that there is damage to the upper side of the battery pack 26. On the other hand, if wireless communication is substantially established with the tire pressure sensor 34 located below the battery pack 26, the management control unit 80 determines that there is damage to the lower side of the battery pack 26.

[0050] When wireless communication is substantially established with both the rearview camera 32 and the tire pressure sensor 34, the management control unit 80 may estimate the location of damage in the battery pack 26 based on the location where wireless communication was established more frequently within a predetermined period. In addition to this example, the management control unit 80 may estimate the location of damage in the battery pack 26 based on the location where the radio wave intensity of the wireless communication is stronger.

[0051] Furthermore, the tire pressure sensors 34, which are an example of second wireless communication units, are provided dispersedly around the horizontal periphery of the battery pack 26. The management control unit 80 may determine that the battery pack 26 is damaged at a horizontal position on the battery pack 26 that corresponds to a tire pressure sensor 34 with which wireless communication has been substantially established. For example, when wireless communication has been substantially established with one of the multiple tire pressure sensors 34, the management control unit 80 may determine that the battery pack 26 is damaged at the left front position.

[0052] In addition, if wireless communication is not substantially established with either the rearview camera 32 or the tire pressure sensor 34, the management control unit 80 determines that the battery pack 26 is not damaged.

[0053] Fig. 4 is a flowchart showing an example of the flow of operations of the management control unit 80 in the management unit 28. When a predetermined interrupt timing occurs at a predetermined cycle while the vehicle 1 is in an ignition-on state (IG-ON), the management control unit 80 executes a series of processes shown in Fig. 4.

[0054] Here, when a passenger in vehicle 1 performs an input operation indicating ignition off (IG-OFF), vehicle control unit 48 performs a predetermined pre-processing to stop the operation of vehicle 1, and then stops the operation of vehicle 1 and sets it to the IG-OFF state. For example, in this pre-processing, vehicle control unit 48 transmits information to management control unit 80 that an IG-OFF command has been issued.

[0055] When a predetermined interrupt timing arrives, the management control unit 80 first determines whether or not the above-mentioned information indicating that an IG-OFF command has been received (S10). If the information indicating that an IG-OFF command has been received has not been received (NO in S10), the management control unit 80 executes battery periodic processing (S11). In the battery periodic processing, the management control unit 80 acquires current battery information, including the current battery voltage and current battery temperature, from each monitoring unit 24. Then, the management control unit 80 transmits the acquired battery information to the vehicle control device 30.

[0056] Next, the management control unit 80 determines whether a check execution condition is met (S12). The check execution condition indicates a criterion for determining whether to check for damage to the battery pack 26. The check execution condition may be, for example, whether a predetermined time has elapsed since the previous check. In this embodiment, the check execution condition is determined to be met when the predetermined time has elapsed since the previous check. The predetermined time in the check execution condition may be, for example, a time (e.g., several seconds) longer than the period (e.g., several milliseconds) of a predetermined interrupt timing for starting the series of processes in FIG. 4.

[0057] The check execution condition is not limited to a condition related to the elapsed time since the previous check. For example, the check execution condition may be a condition that increases the possibility of an impact being applied to the battery pack 26, such as an absolute value of the amount of change in acceleration per unit time in the vehicle 1 being equal to or greater than a predetermined threshold.

[0058] If the check execution condition is met (YES in S12), the management control unit 80 performs a wireless communication attempt process (S13), then performs a determination execution process (S14), and ends the series of processes in FIG. 4. The wireless communication attempt process is a process of attempting wireless communication between the first wireless communication unit and the second wireless communication unit. The determination execution process is a process of determining whether or not the battery pack 26 is damaged based on the results of the wireless communication attempt in the wireless communication attempt process. The wireless communication attempt process and the determination execution process will be described in detail later.

[0059] If the check execution condition is not met (NO in S12), the management control unit 80 ends the series of processes in FIG.

[0060] Also, in step S10, if information indicating that IG-OFF has been instructed is received (YES in S10), the management control unit 80 resets the number of upper communication attempts and the number of lower communication attempts to their initial values ​​(S15), and terminates the series of processes in Figure 4.

[0061] The number of upper side communications indicates the number of times that upper side wireless communications, which are wireless communications between the first wireless communication unit and the second wireless communication unit located above the battery pack 26, have been established. The number of lower side communications indicates the number of times that lower side wireless communications, which are wireless communications between the first wireless communication unit and the second wireless communication unit located below the battery pack 26, have been established. Note that, since the same number of tire pressure sensors 34 as the number of wheels are provided, multiple lower side communications are provided and set for each tire pressure sensor 34.

[0062] The upper communication count and the lower communication count are used in the wireless communication attempt process and the determination execution process. The upper communication count is counted up each time an upper wireless communication is established in the wireless communication attempt process. The lower communication count for each tire pressure sensor 34 is counted up each time a lower wireless communication is established with the corresponding tire pressure sensor 34 in the wireless communication attempt process.

[0063] When the upper-side communication count and the lower-side communication count are reset in step S15, the next time the ignition is turned on, the upper-side communication count and the lower-side communication count will be counted from their initial values. That is, the upper-side communication count and the lower-side communication count are the counts for one driving cycle from ignition on to ignition off. Note that the count period for the upper-side communication count and the lower-side communication count is not limited to one driving cycle, and may be set to any period, such as one hour or one day.

[0064] 5 is a flowchart illustrating the flow of the wireless communication attempt process (S13). When the wireless communication attempt process starts, the management control unit 80 attempts wireless communication with the rearview camera 32 (S20). Next, the management control unit 80 determines whether wireless communication has been established with the rearview camera 32 (S21).

[0065] If wireless communication with the rearview camera 32 is established (YES in S21), the management control unit 80 determines whether the electric field strength in the wireless communication with the rearview camera 32 is strong (S22). Specifically, if the absolute value of the electric field strength is equal to or greater than a predetermined threshold, the management control unit 80 determines that the electric field strength is strong.

[0066] If the field strength in the wireless communication with the rearview camera 32 is strong (YES in S22), the management control unit 80 increments the number of upper side communications by "1" (S23) and proceeds to the processing of step S24. In other words, because wireless communication with the rearview camera 32 has been established with a sufficiently strong field strength, the management control unit 80 has counted up the number of upper side communications by "1".

[0067] If wireless communication with the rearview camera 32 has not been established (NO in S21), the management control unit 80 does not count up the number of upper side communications and proceeds to the process of step S24. On the other hand, if wireless communication with the rearview camera 32 has been established (YES in S21) but the field strength of the wireless communication is weak (NO in S22), the management control unit 80 does not count up the number of upper side communications and proceeds to the process of step S24.

[0068] In step S24, the management control unit 80 selects one tire pressure sensor 34 from the four tire pressure sensors 34 (S24). Next, the management control unit 80 attempts wireless communication with the selected tire pressure sensor 34 (S25). Next, the management control unit 80 determines whether wireless communication has been established with the selected tire pressure sensor 34 (S26).

[0069] If wireless communication is established with the selected tire pressure sensor 34 (YES in S26), the management control unit 80 determines whether the electric field strength in the wireless communication with the tire pressure sensor 34 is strong (S27). Specifically, if the absolute value of the electric field strength is equal to or greater than a predetermined threshold, the management control unit 80 determines that the electric field strength is strong.

[0070] If the electric field strength in the wireless communication with the selected tire pressure sensor 34 is strong (YES in S27), the management control unit 80 increments the number of lower side communications corresponding to the selected tire pressure sensor 34 by "1" (S28) and proceeds to the processing of step S29. In other words, because wireless communication with the selected tire pressure sensor 34 has been established with a sufficiently strong electric field strength, the management control unit 80 has counted up the number of lower side communications corresponding to the selected tire pressure sensor 34 by "1".

[0071] If wireless communication is not established with the selected tire pressure sensor 34 (NO in S26), the management control unit 80 does not count up the number of lower side communications corresponding to the selected tire pressure sensor 34, and proceeds to the processing of step S29. Also, if wireless communication is established with the selected tire pressure sensor 34 (YES in S26) but the field strength of the wireless communication is weak (NO in S27), the management control unit 80 does not count up the number of lower side communications corresponding to the selected tire pressure sensor 34, and proceeds to the processing of step S29.

[0072] In step S29, the management control unit 80 determines whether or not there are any remaining tire pressure sensors 34 that have not yet attempted wireless communication among the four tire pressure sensors 34 (S29). If there are any remaining tire pressure sensors 34 (YES in S29), the management control unit 80 selects one tire pressure sensor 34 from the remaining tire pressure sensors 34 (S24), and repeats the processing from step S25 onwards.

[0073] On the other hand, if there are no remaining tire pressure sensors 34 (NO in S29), wireless communication has been attempted for all tire pressure sensors 34, so the management control unit 80 terminates the wireless communication attempt process (S13) and proceeds to the judgment execution process (S14).

[0074] 5, when wireless communication with the rearview camera 32 is established and the field strength of the wireless communication is strong, the number of upper side communications is counted up by "1." However, the management control unit 80 may omit the determination of the field strength and count up the number of upper side communications by "1" when wireless communication with the rearview camera 32 is established.

[0075] 5, when wireless communication with a selected tire pressure sensor 34 is established and the field strength of the wireless communication is strong, the number of lower side communications corresponding to the selected tire pressure sensor 34 is counted up by "1." However, the management control unit 80 may omit the determination of the field strength, and instead, when wireless communication with the selected tire pressure sensor 34 is established, the number of lower side communications corresponding to the selected tire pressure sensor 34 may be counted up by "1."

[0076] 6 is a flowchart illustrating the flow of the determination execution process (S14). When the determination execution process is started, the management control unit 80 determines whether the number of upper side communications is equal to or greater than a predetermined number (S30). The predetermined number of upper side communications is preferably set to a value, such as five, that allows for distinguishing between upper side wireless communications established due to damage to the battery pack 26 and upper side wireless communications established by chance. Note that the predetermined number of upper side communications is not limited to the number illustrated, and may be set to any number of times, at least one.

[0077] If the number of upper-side communications is equal to or greater than the predetermined number (YES in S30), the management control unit 80 determines whether any of the lower-side communications is equal to or greater than the predetermined number (S31). In other words, the processing of step S31 corresponds to determining whether there is one or more lower-side communications that are equal to or greater than the predetermined number among the multiple lower-side communications for each tire pressure sensor 34. The predetermined number for the lower-side communications may be set to the same as the predetermined number for the upper-side communications, or may be set to a different number. It is preferable that the predetermined number for the lower-side communications is set to a number, such as five, that allows for distinguishing between lower-side wireless communications established due to damage to the battery pack 26 and lower-side wireless communications established by chance. Note that the predetermined number for the lower-side communications is not limited to the number illustrated above, and may be set to any number equal to or greater than one.

[0078] If the number of upper side communications is equal to or greater than the predetermined number (YES in S30) and all lower side communications are less than the predetermined number (NO in S31), the management control unit 80 determines that there is damage to the upper part of the battery pack 26 (S33) and proceeds to processing of step S39.

[0079] Furthermore, if any of the lower side communication counts is equal to or greater than a predetermined count (YES in S31), the management control unit 80 determines whether the upper side communication count is equal to or greater than the largest lower side communication count among the multiple lower side communication counts (S32).

[0080] If the number of upper side communications is equal to or greater than the maximum number of lower side communications (YES in S32), the management control unit 80 determines that the upper part of the battery pack 26 is damaged (S33), and proceeds to the process of step S39.

[0081] On the other hand, if the number of upper-side communications is less than the maximum number of lower-side communications (NO in S32), the management control unit 80 determines that there is damage to the lower part of the battery pack 26 (S35). In other words, when both upper-side wireless communication and lower-side wireless communication are established, the management control unit 80 determines that there is damage to the position corresponding to the upper-side wireless communication or the lower-side wireless communication, whichever is established more frequently.

[0082] Furthermore, in step S30, if the number of upstream communications is less than the predetermined number (NO in S30), the management control unit 80 determines whether the number of downstream communications is equal to or greater than the predetermined number (S34). The processing content of step S34 is the same as the processing content of step S31.

[0083] If the number of upper side communications is less than the predetermined number (NO in S30) and the number of lower side communications of any one of the upper side is equal to or greater than the predetermined number (YES in S34), the management control unit 80 determines that the lower part of the battery pack 26 is damaged (S35).

[0084] In this way, the management control unit 80 can estimate whether the battery pack 26 is damaged or not based on the number of times wireless communication is established between the inside and outside of the battery pack 26. Furthermore, by distributing the second wireless communication units outside the battery pack 26 above and below the battery pack 26, the management control unit 80 can also estimate the location of damage in the battery pack 26 (for example, the top or bottom).

[0085] After determining that there is damage to the lower part of the battery pack 26, the management control unit 80 identifies the tire pressure sensor 34 of the four tire pressure sensors 34 that has the highest number of lower-side communications corresponding to the tire pressure sensor 34 (S36). Next, the management control unit 80 identifies the horizontal position of the damage in the battery pack 26 based on the position of the identified tire pressure sensor 34 (S37), and proceeds to the processing of S39.

[0086] For example, the entire battery pack 26 can be divided into four sections: left front, right front, left rear, and right rear. Let us assume that the management control unit 80 has identified the tire pressure sensor 34a installed on the left front wheel among the four tire pressure sensors 34. The identified left front tire pressure sensor 34a is the closest to the left front side of the battery pack 26 among the four horizontal sections of the battery pack 26. Therefore, in this case, the management control unit 80 can determine that damage has occurred in the left front position of the battery pack 26.

[0087] Since the second wireless communication units below the battery pack 26 are provided dispersedly around the battery pack 26 in the horizontal direction, the management control unit 80 can also estimate the horizontal position of the damage when it determines that there is damage to the lower side of the battery pack 26. This allows the management control unit 80 to estimate the position of the damage in the battery pack 26 in more detail.

[0088] Also, if the number of upper side communications is less than the predetermined number (NO in S30) and all lower side communications are less than the predetermined number (NO in S34), the management control unit 80 determines that the battery pack 26 is not damaged (S38) and proceeds to processing of step S39.

[0089] In step S39, the management control unit 80 transmits the determination result regarding damage to the battery pack 26 to the vehicle control device 30, and ends the determination execution process.

[0090] If the received determination result indicates that at least the battery pack 26 is damaged, regardless of the location of the damage in the battery pack 26, the vehicle control device 30 may issue a predetermined notification indicating that the battery pack 26 is damaged. In this case, the vehicle control unit 48 may not only notify the presence or absence of damage in the battery pack 26, but also the location of the damage indicated by the received determination result. Any notification method may be used, such as displaying an alarm on an instrument panel or the like.

[0091] As described above, the battery pack monitoring device 10 of the first embodiment estimates whether the battery pack 26 is damaged based on the establishment state of wireless communication between the first wireless communication unit inside the battery pack 26 and the second wireless communication unit outside the battery pack 26. Therefore, the battery pack monitoring device 10 of the first embodiment is capable of monitoring the battery pack 26 and detecting damage to the battery pack 26.

[0092] Furthermore, in the battery pack monitoring device 10 of the first embodiment, a plurality of second wireless communication units are provided at a plurality of positions. Then, in the battery pack monitoring device 10 of the first embodiment, the position of damage in the battery pack 26 is estimated based on the position of the second wireless communication unit that has established wireless communication with the first wireless communication unit. Therefore, the battery pack monitoring device 10 of the first embodiment can detect not only whether or not the battery pack 26 is damaged, but also the position of the damage in the battery pack 26.

[0093] In the battery pack monitoring device 10 of the first embodiment, a plurality of second wireless communication units are provided at positions above the battery pack 26 and at positions below the battery pack 26. Therefore, in the battery pack monitoring device 10 of the first embodiment, when wireless communication is established with a second wireless communication unit located above the battery pack 26, it can be estimated that there is damage to the upper part of the battery pack 26. In the battery pack monitoring device 10 of the first embodiment, when wireless communication is established with a second wireless communication unit located below the battery pack 26, it can be estimated that there is damage to the lower part of the battery pack 26.

[0094] In the battery pack monitoring device 10 of the first embodiment, multiple second wireless communication units are disposed in a dispersed manner around the horizontal direction of the battery pack 26. Therefore, in the battery pack monitoring device 10 of the first embodiment, the horizontal damage position in the battery pack 26 can be estimated based on the position of the second wireless communication unit with which wireless communication is established.

[0095] In the battery pack monitoring device 10 of the first embodiment, the rearview camera 32 and the tire pressure sensor 34 function as the second wireless communication unit outside the battery pack 26. However, the second wireless communication unit is not limited to the rearview camera 32 and the tire pressure sensor 34. Any device that is provided outside the battery pack 26 of the vehicle 1 and has a wireless communication function may be used as the second wireless communication unit.

[0096] Furthermore, in the battery pack monitoring device 10 of the first embodiment, the management unit 28, rearview camera 32, and tire pressure sensor 34 that are pre-installed in the vehicle 1 are used as the first wireless communication unit and the second wireless communication unit. Therefore, compared to an embodiment in which the first wireless communication unit and the second wireless communication unit are newly installed, there is no need to ensure installation space for the first wireless communication unit and the second wireless communication unit, and the battery pack monitoring device 10 can be easily applied to the vehicle 1. Note that devices that function as the first wireless communication unit or the second wireless communication unit may also be newly installed in the vehicle 1.

[0097] Furthermore, in the battery pack monitoring device 10 of the first embodiment, a plurality of second communication units are provided outside the battery pack 26. However, it is sufficient that at least one second wireless communication unit is provided. For example, the second wireless communication unit is not limited to a configuration in which both the rearview camera 32 and the tire pressure sensor 34 are provided, but may be provided with only one of the rearview camera 32 and the tire pressure sensor 34. Furthermore, the second wireless communication unit is not limited to a configuration in which a plurality of tire pressure sensors 34 are provided, but may be provided with only one of the tire pressure sensors 34.

[0098] (Second embodiment) In the first embodiment, wireless communication is attempted between the management unit 28 in the battery pack 26 and the rearview camera 32 or the tire pressure sensor 34. However, the battery pack 26 also houses a monitoring unit 24 that has wireless communication capabilities. Therefore, in the second embodiment, wireless communication is attempted between the monitoring unit 24 and the rearview camera 32 or the tire pressure sensor 34, and damage to the battery pack 26 is estimated based on the establishment status of the wireless communication.

[0099] Fig. 7 is a schematic plan view showing the configuration of a vehicle 1 to which a battery pack monitoring device 110 according to the second embodiment is applied. In Fig. 7, indicators such as ripple marks indicate that wireless communication is being attempted between the monitoring communication unit 50 of the monitoring unit 24 and the rearview camera 32, and that wireless communication is being attempted between the monitoring communication unit 50 of the monitoring unit 24 and the tire pressure sensor 34.

[0100] The first wireless communication unit in the battery pack monitoring device 110 of the second embodiment is, for example, the monitoring unit 24 provided inside the battery pack 26, more specifically, the monitoring communication unit 50 of the monitoring unit 24. As shown in Fig. 7, in the battery pack monitoring device 110, the first wireless communication units are provided inside the battery pack 26 and distributed in the horizontal direction of the battery pack 26.

[0101] The monitoring unit 24a is disposed closer to the left front in the internal space of the battery pack 26 relative to the other monitoring units 24. Of the distances between the monitoring unit 24a and each tire pressure sensor 34, the distance between the monitoring unit 24a and the tire pressure sensor 34a installed on the left front wheel is the shortest. Therefore, the monitoring unit 24a disposed closer to the left front corresponds to the tire pressure sensor 34a installed on the left front wheel.

[0102] The monitoring unit 24b is disposed closer to the right front in the internal space of the battery pack 26 relative to the other monitoring units 24. Of the distances between the monitoring unit 24b and each tire pressure sensor 34, the distance between the monitoring unit 24b and the tire pressure sensor 34b installed on the right front wheel is the shortest. Therefore, the monitoring unit 24b disposed closer to the right front corresponds to the tire pressure sensor 34b installed on the right front wheel.

[0103] The monitoring unit 24c is disposed toward the left rear in the internal space of the battery pack 26 relative to the other monitoring units 24. Of the distances between the monitoring unit 24c and each tire pressure sensor 34, the distance between the monitoring unit 24c and the tire pressure sensor 34c installed on the left rear wheel is the shortest. Therefore, the monitoring unit 24c disposed toward the left rear corresponds to the tire pressure sensor 34c installed on the left rear wheel.

[0104] The monitoring unit 24d is disposed toward the rear right in the internal space of the battery pack 26 relative to the other monitoring units 24. Of the distances between the monitoring unit 24d and each tire pressure sensor 34, the distance between the monitoring unit 24d and the tire pressure sensor 34d installed on the rear right wheel is the shortest. Therefore, the monitoring unit 24d disposed toward the rear right corresponds to the tire pressure sensor 34d installed on the rear right wheel.

[0105] In the battery pack monitoring device 110 of the second embodiment, the management control unit 80 of the management unit 28 instructs each of the monitoring units 24 to attempt wireless communication, thereby realizing an attempt at wireless communication between the monitoring units 24 and the rearview camera 32 or the tire pressure sensor 34. In the second embodiment, the contents of the wireless communication attempt process (S13) and the determination execution process (S14) differ from those of the first embodiment.

[0106] Furthermore, in the battery pack monitoring device 110 of the second embodiment, the location of damage in the battery pack 26 is estimated based on the location of the first wireless communication unit with which wireless communication is established with the second wireless communication unit. For example, if a monitoring unit 24a, which is located closer to the left front among the multiple monitoring units 24, establishes wireless communication with a tire pressure sensor 34a installed on the left front wheel, it is estimated that damage is present in the left front position of the battery pack 26.

[0107] As described above, the monitoring unit 24a corresponds to the tire pressure sensor 34a, and therefore wireless communication between the monitoring unit 24a and the tire pressure sensor 34a is more likely to be established than wireless communication between the monitoring unit 24a and any other tire pressure sensor 34 other than the tire pressure sensor 34a.

[0108] Therefore, the monitoring unit 24a may attempt wireless communication with at least the tire pressure sensor 34a corresponding to the monitoring unit 24a, and may omit attempts to communicate wirelessly with the other tire pressure sensors 34. Then, when the number of lower-side communications with at least the tire pressure sensor 34a for the monitoring unit 24a reaches or exceeds a predetermined number, the management control unit 80 may estimate that damage exists in the battery pack 26 at a horizontal position corresponding to the position of the monitoring unit 24a.

[0109] The above description has been given with respect to monitoring unit 24a. However, similar to monitoring unit 24a, monitoring units 24b, 24c, and 24d may also attempt wireless communication with the tire pressure sensors 34 corresponding to their respective monitoring units 24, and omit attempts of wireless communication with the other tire pressure sensors 34. Then, for each monitoring unit 24, when the number of lower-side communications between that monitoring unit 24 and its corresponding tire pressure sensor 34 reaches or exceeds a predetermined number, the management control unit 80 may estimate that damage exists in the horizontal position of the battery pack 26 corresponding to the position of that monitoring unit 24.

[0110] 8 is a diagram illustrating the flow of the wireless communication attempt process (S13) in the second embodiment. When the wireless communication attempt process starts, the management control unit 80 selects a monitoring unit 24 with which to attempt wireless communication (S40). Next, the management control unit 80 wirelessly communicates with the selected monitoring unit 24, and instructs the selected monitoring unit 24 to attempt wireless communication between the selected monitoring unit 24 and the rearview camera 32 (S41). As a result, the selected monitoring unit 24 attempts wireless communication with the rearview camera 32 based on the instruction from the management control unit 80.

[0111] Next, the management control unit 80 determines whether wireless communication has been established between the selected monitoring unit 24 and the rearview camera 32 (S42).

[0112] If wireless communication between the selected monitoring unit 24 and the rearview camera 32 is established (YES in S42), the management control unit 80 determines whether the electric field strength in the wireless communication between the selected monitoring unit 24 and the rearview camera 32 is strong (S43). For example, if the absolute value of the electric field strength is equal to or greater than a predetermined threshold, the management control unit 80 determines that the electric field strength is strong.

[0113] If the electric field strength is strong (YES in S43), the management control unit 80 increments the upper communication count corresponding to the selected monitoring unit 24 by "1" (S44), and proceeds to the processing of step S45. Here, in the second embodiment, since each of the multiple monitoring units 24 attempts wireless communication with the rearview camera 32, multiple upper communication counts are provided and set for each monitoring unit 24. In step S44, the upper communication count corresponding to the selected monitoring unit 24 among the multiple upper communication counts is counted up by "1".

[0114] Furthermore, if wireless communication between the selected monitoring unit 24 and the rearview camera 32 is not established (NO in S42), the management control unit 80 does not count up the number of upper side communications and proceeds to the processing of step S45. Furthermore, if wireless communication between the selected monitoring unit 24 and the rearview camera 32 is established (YES in S42) but the field strength of the wireless communication is weak (NO in S43), the management control unit 80 does not count up the number of upper side communications and proceeds to the processing of step S45.

[0115] In step S45, the management control unit 80 wirelessly communicates with the selected monitoring unit 24, and instructs the selected monitoring unit 24 to attempt wireless communication between the selected monitoring unit 24 and the tire pressure sensor 34 corresponding to the selected monitoring unit 24 (S45). As a result, the selected monitoring unit 24 attempts wireless communication with the tire pressure sensor 34 corresponding to the selected monitoring unit 24 based on the instruction from the management control unit 80.

[0116] Next, the management control unit 80 determines whether wireless communication has been established between the selected monitoring unit 24 and the tire pressure sensor 34 corresponding to the selected monitoring unit 24 (S46).

[0117] If wireless communication is established between the selected monitoring unit 24 and the tire pressure sensor 34 corresponding to the selected monitoring unit 24 (YES in S46), the management control unit 80 determines whether the electric field strength in the wireless communication between the selected monitoring unit 24 and the tire pressure sensor 34 corresponding to the selected monitoring unit 24 is strong (S47). For example, if the absolute value of the electric field strength is equal to or greater than a predetermined threshold, the management control unit 80 determines that the electric field strength is strong.

[0118] If the electric field strength is strong (YES in S47), the management control unit 80 increments the number of lower side communications for the tire pressure sensor 34 corresponding to the selected monitoring unit 24 by "1" (S48), and proceeds to the processing of step S49. Here, in the second embodiment, since each of the multiple monitoring units 24 attempts wireless communication with the tire pressure sensor 34 corresponding to that monitoring unit 24, multiple lower side communication counts are provided and set for each monitoring unit 24. In step S48, the lower side communication count corresponding to the selected monitoring unit 24 among the multiple lower side communication counts is counted up by "1".

[0119] Furthermore, if wireless communication is not established between the selected monitoring unit 24 and the tire pressure sensor 34 corresponding to the selected monitoring unit 24 (YES in S46), the management control unit 80 does not count up the number of lower-side communications and proceeds to the processing of step S49. Furthermore, if wireless communication is established between the selected monitoring unit 24 and the tire pressure sensor 34 corresponding to the selected monitoring unit 24 (YES in S46) but the field strength of the wireless communication is weak (NO in S47), the management control unit 80 does not count up the number of lower-side communications and proceeds to the processing of step S49.

[0120] In step S49, the management control unit 80 determines whether or not there are any remaining monitoring units 24 that have not yet attempted wireless communication among all of the monitoring units 24 (S49). If there are any remaining monitoring units 24 (YES in S49), the management control unit 80 selects a monitoring unit 24 from the remaining monitoring units 24 (S40), and repeats the processing from step S41 onwards.

[0121] When wireless communication has been attempted for all the monitoring units 24 (NO in S49), the management control unit 80 ends the wireless communication attempt process (S13) and proceeds to the determination execution process (S14).

[0122] The management control unit 80 may omit the determination of the electric field strength in step S43, and may increment the number of upper communications corresponding to the selected monitoring unit 24 by "1" when wireless communication is established between the selected monitoring unit 24 and the rearview camera 32. The management control unit 80 may omit the determination of the electric field strength in step S47, and may increment the number of lower communications corresponding to the selected monitoring unit 24 by "1" when wireless communication is established between the selected monitoring unit 24 and the tire pressure sensor 34 corresponding to the selected monitoring unit 24.

[0123] 9 is a flowchart illustrating the flow of the determination execution process (S14) in the second embodiment. When the determination execution process is started, the management control unit 80 determines whether any of the upstream communication counts is equal to or greater than a predetermined count (S50). The predetermined count here is set to, for example, the same count as that of step S30 in FIG. 6 in the first embodiment, but is not limited to this example and may be set to any number equal to or greater than one.

[0124] If any of the upper communication counts is equal to or greater than a predetermined number (YES in S50), the management control unit 80 determines whether any of the lower communication counts is equal to or greater than a predetermined number (S51). The predetermined number here is set to, for example, the same number as that in step S31 of Fig. 6 in the first embodiment, but is not limited to this example and may be set to any number equal to or greater than one.

[0125] If the number of communications on any of the upper sides is equal to or greater than the predetermined number (YES in S50) but the number of communications on any of the lower sides is less than the predetermined number (NO in S51), the management control unit 80 determines that there is damage to the upper part of the battery pack 26 (S53) and proceeds to processing of step S59.

[0126] Furthermore, if any of the upper communication counts is greater than or equal to a predetermined number (YES in S50) and any of the lower communication counts is greater than or equal to a predetermined number (YES in S51), the management control unit 80 determines whether the highest upper communication count among the upper communication counts is greater than or equal to the highest lower communication count among the lower communication counts (S52).

[0127] If the highest number of upper side communications among the upper side communications is equal to or greater than the highest number of lower side communications among the lower side communications (YES in S52), the management control unit 80 determines that there is damage to the upper part of the battery pack 26 (S53) and proceeds to processing of step S59.

[0128] If the highest number of upper side communications among the upper side communications is less than the highest number of lower side communications among the lower side communications (NO in S52), the management control unit 80 determines that the lower part of the battery pack 26 is damaged (S55).

[0129] If any of the upper communication counts is less than the predetermined number (NO in S50), the management control unit 80 determines whether any of the lower communication counts is equal to or greater than the predetermined number (S54). The process of this step S54 is the same as the process of step S51.

[0130] If any of the upper side communication counts is less than the predetermined count (NO in S50) and any of the lower side communication counts is equal to or greater than the predetermined count (YES in S54), the management control unit 80 determines that the lower part of the battery pack 26 is damaged (S55).

[0131] After determining that the battery pack 26 has damage in its lower portion, the management control unit 80 identifies, among the multiple monitoring units 24, the monitoring unit 24 with the highest number of lower-portion communications (S56). Next, the management control unit 80 identifies the horizontal position of the damage in the battery pack 26 based on the position of the identified monitoring unit 24 (S57), and proceeds to the processing of step S59. For example, suppose that, of the four monitoring units 24, the management control unit 80 identifies the monitoring unit 24 that is located closer to the left front in the battery pack 26. In this case, the management control unit 80 determines that the battery pack 26 has damage in its left front position.

[0132] Furthermore, if the number of upper communications of any one of the two is less than the predetermined number (NO in S50) and the number of lower communications of any one of the two is less than the predetermined number (NO in S54), the management control unit 80 determines that the battery pack 26 is not damaged (S58) and proceeds to processing of step S59.

[0133] In step S59, the management control unit 80 transmits the determination result regarding damage to the battery pack 26 to the vehicle control device 30 (S59), and ends the determination execution process.

[0134] In this way, the battery pack monitoring device 110 of the second embodiment can monitor the battery pack 26 and detect damage to the battery pack 26, similar to the first embodiment.

[0135] Furthermore, in the battery pack monitoring device 110 of the second embodiment, first wireless communication units are provided inside the battery pack 26 and dispersed in the horizontal direction of the battery pack 26. Then, in the battery pack monitoring device 110 of the second embodiment, the location of damage in the battery pack 26 is estimated based on the location of the first wireless communication unit with which wireless communication is established with the second wireless communication unit. Therefore, the battery pack monitoring device 110 of the second embodiment can detect not only whether the battery pack 26 is damaged but also the location of the damage in the battery pack 26.

[0136] (Third embodiment) 10 is a schematic plan view showing the configuration of a vehicle 1 to which a battery pack monitoring device 210 according to the third embodiment is applied. As described above, in the first and second embodiments, only one battery pack 26 is installed in the vehicle 1. In contrast, in the third embodiment, a battery pack 226a, a battery pack 226b, a battery pack 226c, and a battery pack 226d are installed in the vehicle 1.

[0137] Hereinafter, battery pack 226a, battery pack 226b, battery pack 226c, and battery pack 226d may be collectively referred to as battery pack 226. Note that the example is not limited to the case where four battery packs 226 are installed in vehicle 1, and two, three, or five or more battery packs 226 may be installed in vehicle 1.

[0138] Battery pack 226a is disposed closer to the left front of vehicle 1 relative to the other battery packs 226. Of the distances between battery pack 226a and each tire pressure sensor 34, the distance between battery pack 226a and tire pressure sensor 34a installed on the left front wheel is the shortest. Therefore, battery pack 226a disposed closer to the left front corresponds to tire pressure sensor 34a installed on the left front wheel.

[0139] Battery pack 226b is disposed closer to the front right of vehicle 1 relative to the other battery packs 226. Of the distances between battery pack 226b and each tire pressure sensor 34, the distance between battery pack 226b and tire pressure sensor 34b installed on the front right wheel is the shortest. Therefore, battery pack 226b disposed closer to the front right corresponds to tire pressure sensor 34b installed on the front right wheel.

[0140] Battery pack 226c is disposed toward the rear left of vehicle 1 relative to the other battery packs 226. Of the distances between battery pack 226c and each tire pressure sensor 34, the distance between battery pack 226c and tire pressure sensor 34c installed on the rear left wheel is the shortest. Therefore, battery pack 226c disposed toward the rear left corresponds to tire pressure sensor 34c installed on the rear left wheel.

[0141] Battery pack 226d is disposed toward the rear right relative to the other battery packs 226. Of the distances between battery pack 226d and each tire pressure sensor 34, the distance between battery pack 226d and tire pressure sensor 34d installed on the rear right wheel is the shortest. Therefore, battery pack 226d disposed toward the rear right corresponds to tire pressure sensor 34d installed on the rear right wheel.

[0142] Battery pack 226a houses management unit 228a. Battery pack 226b houses management unit 228b. Battery pack 226c houses management unit 228c. Battery pack 226d houses management unit 228d. Hereinafter, management units 228a, 228b, 228c, and 228d may be collectively referred to as management units 228.

[0143] Similar to the first embodiment, the management unit 228 in each battery pack 226 has a management communication unit 70 capable of wireless communication. Also, similar to the first embodiment, the processor 72 of each management unit 228 functions as a management control unit 80. Therefore, similar to the first embodiment, the management control unit 80 of each management unit 228 can attempt wireless communication with the rearview camera 32 and the tire pressure sensor 34. In FIG. 10, an indicator such as a ripple mark indicates that wireless communication is being attempted between each management unit 228 and the rearview camera 32 or the tire pressure sensor 34.

[0144] As in the first embodiment, the management control unit 80 of each management unit 228 can estimate whether or not the battery pack 226 to which the management unit 228 belongs is damaged and the location of the damage, based on the establishment state of wireless communication between the management unit 228 and the rearview camera 32 or the tire pressure sensor 34. In other words, even if the vehicle 1 is provided with a plurality of battery packs 226, it is possible to estimate, for each battery pack 226, whether or not the battery pack 226 is damaged and the location of the damage.

[0145] As described above, the battery pack 226a corresponds to the tire pressure sensor 34a. Therefore, wireless communication between the management unit 228a of the battery pack 226a and the tire pressure sensor 34a is more likely to be established than wireless communication between the management unit 228a and any other tire pressure sensor 34a.

[0146] Therefore, the management control unit 80 of the management unit 228a may attempt wireless communication with at least the tire pressure sensor 34 corresponding to the battery pack 226a, and may omit attempts to communicate wirelessly with the other tire pressure sensors 34. Then, the management control unit 80 of the management unit 228a may assume that the battery pack 226a to which the management unit 228a belongs is damaged when the number of lower-side communications with at least the tire pressure sensor 34a reaches or exceeds a predetermined number.

[0147] Here, the estimation of damage to battery pack 226a has been described. However, similar to battery pack 226a, battery packs 226b, 226c, and 226d may also attempt wireless communication with the tire pressure sensors 34 corresponding to each battery pack 226, and may omit attempts of wireless communication with the other tire pressure sensors 34. Then, the management control unit 80 of each management unit 228 may estimate that the battery pack 226 to which the management unit 228 belongs is damaged when at least the number of lower-side communications with the corresponding tire pressure sensor 34 reaches or exceeds a predetermined number.

[0148] In this way, similar to the first embodiment, the battery pack monitoring device 210 of the third embodiment is capable of monitoring the battery pack 226 and detecting damage to the battery pack 226. Furthermore, similar to the first embodiment, the battery pack monitoring device 210 of the third embodiment is capable of detecting not only whether or not the battery pack 226 is damaged, but also the location of the damage in the battery pack 226.

[0149] While the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such embodiments. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that such modifications and alterations also fall within the technical scope of the present invention.

[0150] For example, in each of the above embodiments, the control device that performs the wireless communication attempt process and the determination execution process is the management unit 28, 228 in the battery pack 26, 226. However, the embodiment is not limited to the management unit 28, 228 performing the wireless communication attempt process and the determination execution process. For example, the vehicle control device 30 may perform the wireless communication attempt process and the determination execution process, or any computer installed in the vehicle 1 may perform the wireless communication attempt process and the determination execution process.

[0151] In each of the above embodiments, it is normal for wireless communication between the first wireless communication unit and the second wireless communication unit not to be established. Here, for example, rearview camera 32, which is an example of a second wireless communication unit, establishes wireless communication with vehicle control device 30 through its original function. If a malfunction occurs in rearview camera 32, vehicle control device 30 can detect the malfunction of rearview camera 32 because wireless communication with rearview camera 32 is no longer established.

[0152] Therefore, the vehicle control device 30 may periodically transmit, via wired communication, information about the presence or absence of a malfunction in the second wireless communication unit, such as the rearview camera 32, to the management control unit 80. This allows the management control unit 80 to distinguish whether the state in which wireless communication between the first wireless communication unit and the second wireless communication unit is not established is due to the battery pack 26 not being damaged or due to a malfunction in the second wireless communication unit. [Explanation of symbols]

[0153] 1 vehicle 10, 110, 210 Battery pack monitoring device 22 Battery 24, 24a, 24b, 24c, 24d Monitoring Unit 26, 226 Battery Pack 28, 228 Management Unit 32 Rearview camera 34, 34a, 34b, 34c, 34d Tire pressure sensors 50 Monitoring and Communications Department 70 Management and Communications Department 72 processors 74 memory

Claims

1. a battery pack mounted on the vehicle and housing a battery therein; a first wireless communication unit provided inside the battery pack and capable of wireless communication; a second wireless communication unit provided outside the battery pack in the vehicle and capable of wireless communication; a control device; Equipped with The control device one or more processors; one or more memories coupled to the processor; and The processor: Attempting wireless communication between the first wireless communication unit and the second wireless communication unit; estimating whether or not the battery pack is damaged based on an establishment state of wireless communication between the first wireless communication unit and the second wireless communication unit; A battery pack monitoring device that performs processing including:

2. the second wireless communication unit is provided in a distributed manner at a plurality of positions, 2. The battery pack monitoring device according to claim 1, wherein the processor performs processing that includes estimating a location of damage to the battery pack based on a location of the second wireless communication unit with which wireless communication is established with the first wireless communication unit.

3. the second wireless communication unit is provided in an upper position and a lower position with respect to the battery pack, The processor: determining that an upper portion of the battery pack is damaged when wireless communication is established between the first wireless communication unit and the second wireless communication unit located above the battery pack; 3. The battery pack monitoring device of claim 2, wherein when wireless communication is established between the first wireless communication unit and the second wireless communication unit located below the battery pack, the device executes processing that includes determining that there is damage to a lower portion of the battery pack.

4. the second wireless communication units are provided dispersedly around the battery pack in a horizontal direction, 4. The battery pack monitoring device of claim 2, wherein the processor executes processing that includes determining that damage to the battery pack exists at a horizontal position in the battery pack that corresponds to the second wireless communication unit with which wireless communication is established with the first wireless communication unit.

5. the first wireless communication units are provided inside the battery pack and dispersed in a horizontal direction of the battery pack; 5. The battery pack monitoring device according to claim 1, wherein the processor performs processing that includes estimating a location of damage to the battery pack based on a location of the first wireless communication unit with which wireless communication is established with the second wireless communication unit.

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