Battery monitoring system, battery monitoring device, and battery control device

Abstract

A battery control device (40) is provided with a master-side antenna (43) for performing wireless communication with battery monitoring devices (30, 30A-30D). Each battery monitoring device has a sub-device-side antenna (33) for performing wireless communication with the battery control device. At least one of the radio wave directionality of each sub-device-side antenna and the radio wave directionality of the master-side antenna can be selected from among a plurality of radio wave directionalities in which the directions of the centers of the radio wave directionalities differ. In a channel used for wireless communication between the master-side antenna and the slave-side antenna, radio wave directionality other than the radio wave directionality in which the communication quality of the wireless communication is the lowest among the radio wave directionalities is set.

Description

Citation of related applications

[0001] This application is based on Japanese Patent Application No. 2022-098018 filed on June 17, 2022, and the contents thereof are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to a battery monitoring system, a battery monitoring device constituting the battery monitoring system, and a battery control device constituting the battery monitoring system. Background Art

[0003] Conventionally, a battery monitoring system is known, which includes a battery monitoring device and a battery control device, wherein the battery monitoring devices are individually provided corresponding to a plurality of batteries and monitor the states of the batteries. The battery control device has a main machine side antenna for wireless communication with the battery monitoring devices, and each battery monitoring device has a slave machine side antenna for wireless communication with the battery control device.

[0004] Each battery, each battery monitoring device, and the battery control device are housed in a housing. The housing is configured to reflect radio waves at least in part. Therefore, when the battery monitoring device transmits a wireless signal, the transmitted wireless signal is reflected by the wall surface of the housing. As a result, multipath may occur and correct information may not be transmitted from the battery monitoring device to the battery control device.

[0005] In order to deal with such a problem, Patent Document 1 describes a structure in which at least one of the antenna on the main machine side and the antenna on the slave machine side is a directional antenna that irradiates radio waves more strongly in a specified directional direction than in a specified non-directional direction. The directional antenna irradiates radio waves more strongly in the direction along the surface of the battery on which the battery control device or the battery monitoring device is installed than in the direction perpendicular to the surface of the battery on which the battery control device or the battery monitoring device is installed. As a result, the radio wave directivity of the directional antenna can make the wireless communication environment between the battery control device in the storage unit and the battery monitoring device good, and can send correct information from the battery monitoring device to the battery control device. Prior art literature Patent Literature

[0006] Patent Document 1: Japanese Patent No. 6996574 Summary of the invention

[0007] The wireless communication environment between the battery control device and the battery monitoring device in the storage unit may change. Therefore, even if correct information can be transmitted between the battery monitoring device and the battery control device in a certain wireless communication environment, it may not be possible to transmit correct information in another wireless communication environment.

[0008] The main object of the present disclosure is to provide a battery monitoring system capable of performing appropriate wireless communication between a battery control device and a battery monitoring device even if the wireless communication environment changes, a battery monitoring device constituting the battery monitoring system, and a battery control device constituting the battery monitoring system.

[0009] The present invention discloses a battery monitoring system, which includes: a battery monitoring device, the battery monitoring device being individually provided corresponding to each of the plurality of batteries and monitoring the status of the batteries; and Battery control unit, The batteries, the battery monitoring devices and the battery control device are housed in a housing configured to reflect at least a portion of the radio waves, wherein: The battery control device has a base station side antenna for wireless communication with the battery monitoring device. Each of the battery monitoring devices has a slave-side antenna for wirelessly communicating with the battery control device. The radio wave directivity of at least one of the radio wave directivity of each of the above-mentioned slave-side antennas and the radio wave directivity of the above-mentioned base-side antenna can be selected from a plurality of radio wave directivities having different directions of the centers of the radio wave directivities, In a channel used for wireless communication between the base station side antenna and the slave station side antenna, a radio wave directivity other than a radio wave directivity with which the communication quality of the wireless communication is the lowest among the radio wave directivities is set.

[0010] Even when correct information cannot be transmitted between the battery monitoring device and the battery control device in a certain wireless communication environment, correct information can be transmitted between the battery monitoring device and the battery control device by changing the direction of the center of the radio wave directivity of the antenna. In view of this, in the present disclosure, the radio wave directivity of at least one of the radio wave directivity of each sub-machine side antenna and the radio wave directivity of the main machine side antenna can be selected from a plurality of radio wave directivities with different directions of the center of the radio wave directivity. Based on this structure, in the channel used in the wireless communication between the main machine side antenna and the sub-machine side antenna, the radio wave directivity other than the radio wave directivity with the lowest communication quality of wireless transmission among the radio wave directivities is set. Thus, even if the wireless communication environment changes, appropriate wireless communication can be performed between the battery control device and the battery monitoring device.

[0012] In addition, in the above-mentioned channel, the radio wave directivity other than the radio wave directivity in which the communication quality of the above-mentioned wireless transmission is the lowest among the above-mentioned radio wave directivities specifically refers to, for example, the radio wave directivity in which the received power of the above-mentioned battery control device or the above-mentioned battery monitoring device when performing the above-mentioned wireless communication is set to be above a threshold value among the above-mentioned radio wave directivities in the above-mentioned channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above objects, other objects, features and advantages of the present disclosure will become more apparent with reference to the accompanying drawings and the following detailed description. Figure 1 It is a structural diagram of the vehicle according to the first embodiment. Figure 2 is a block diagram showing a battery pack. Figure 3 It is a perspective view showing the arrangement of battery blocks and the like in the casing. Figure 4 yes Figure 3 4-4 line cross-sectional view. Figure 5 It is a diagram showing the arrangement of battery cells constituting a battery block. Figure 6 This is a diagram showing a structure capable of switching between two radio wave directivities. Figure 7 1 is a diagram showing the frequency characteristics of received power corresponding to radio wave directivities A and B. Figure 8 is a diagram showing interference between a main wave and a reflected wave. Fig. 9 It is a time chart showing the transition of the main wave, the reflected wave, and their composite wave. Fig.10 This is a diagram showing the correspondence between the radio wave directivity at which the received power is maximum and each channel. Fig.11 This is a flowchart showing the procedure of processing for generating mapping information that associates the radio wave directivity with the maximum received power with each channel. Fig.12 This is a flowchart showing the procedure of the switching process of the radio wave directivity executed by the battery monitoring device. Fig.13 This is a diagram showing an example of an antenna whose directivity can be changed. Fig.14 This is a diagram showing an example of an antenna whose directivity can be changed. Fig.15 This is a diagram showing an example of an antenna whose directivity can be changed. Fig.16 It is a diagram showing an antenna of a comparative example. Fig.17It is shown Fig.15 A diagram showing a modified example of the structure shown. Fig.18 This is a diagram showing a method of recycling batteries from vehicle-mounted use to stationary use. Fig.19 : is a graph showing the frequency characteristics of received power in vehicle-mounted applications. Fig. 20 This is a diagram showing the frequency characteristics of received power in stationary use. Fig.21 This is a diagram showing the frequency characteristics of the received power when the radio wave directivity of each channel is reset in stationary use. Fig. 22 1 is a diagram showing the frequency characteristics of the received power before the radio wave directivity is switched. Fig.23 : is a graph which shows the frequency characteristic of the received power after switching the radio wave directivity. Fig.24 This is a flowchart showing the procedure of the process of switching the radio wave directivity when an abnormality occurs. Fig.25 This is a perspective view showing the arrangement of battery blocks and the like in a casing according to a modification of the first embodiment. Fig.26 This is a flowchart showing the procedure of a process for generating mapping information that associates the radio wave directivity with the maximum received power with each channel according to the second embodiment. Fig. 27 1 is a flowchart showing the procedure of a process of switching the radio wave directivity executed by the battery control device. Fig.28 This is an overall configuration diagram of an inspection system including a portable terminal, a server, and the like according to a third embodiment. Fig.29 This is a flowchart showing the procedure of processing for generating mapping information that associates the radio wave directivity with the maximum received power with each channel. Fig.30 This is a flowchart showing the procedure of a process for generating mapping information that associates the radio wave directivity with the maximum received power with each channel according to the fourth embodiment. Fig.31 This is a diagram showing an example of specific conditions. Fig.32 This is a flowchart showing the procedure of a process for generating mapping information that associates the radio wave directivity with the maximum received power with each channel according to the fifth embodiment. Fig.33 This is a perspective view showing the arrangement of battery blocks and the like in a casing when an abnormality occurs according to the sixth embodiment. Fig.34This is a flowchart showing the procedure of processing for generating mapping information that associates the radio wave directivity with the maximum received power with each channel. Fig.35 It is a characteristic diagram showing the relationship between each channel, communication error rate, and radio wave directivity in the seventh embodiment. Fig.36 This is a flowchart showing the procedure of processing for generating mapping information that associates the radio wave directivity that minimizes the communication error rate with each channel. Fig.37 It is a characteristic diagram showing the relationship between each channel, the reception power, and the difference in the background noise according to the eighth embodiment. Fig.38 It is a characteristic diagram showing the relationship between each channel, the received power, and the difference in the background noise. Fig.39 This is a flowchart showing the procedure of a process for generating mapping information that associates the radio wave directivity that maximizes the difference between the received power and the noise floor with each channel. Fig.40 It is a diagram showing the arrangement of battery packs in a storage space within a chassis of a vehicle according to a ninth embodiment. Fig.41 yes Fig.40 Sectional view along line 41-41. Fig.42 It is a cross-sectional view of a battery pack according to a tenth embodiment. Fig.43 It is a cross-sectional view of a battery pack according to an eleventh embodiment. Fig.44 It is a diagram showing the arrangement of batteries in a storage space within a chassis of a vehicle according to a twelfth embodiment. Fig.45 It is a perspective view showing a battery according to another embodiment. DETAILED DESCRIPTION

[0014] Hereinafter, multiple embodiments are described with reference to the accompanying drawings. In multiple embodiments, functionally and / or structurally corresponding parts and / or associated parts are sometimes marked with the same reference numerals. For corresponding parts and / or associated parts, reference can be made to the description of other embodiments.

[0015] <First embodiment> A first embodiment of a battery monitoring system according to the present disclosure will be described below with reference to the accompanying drawings. The battery monitoring system is installed in a vehicle such as an electric vehicle or a hybrid vehicle that uses a rotating electric machine as a driving power source.

[0016] Figure 11 is a diagram schematically showing a structure of a vehicle 10. The vehicle 10 includes a battery pack 11, a power control unit (hereinafter referred to as “PCU”) 12, a motor 13, and a vehicle ECU 14.

[0017] The battery pack 11 is installed in the vehicle 10 as a driving power source of the vehicle 10. Specifically, the battery pack 11 is installed in, for example, an engine room, a trunk, under a seat, or under a floor of the vehicle 10. The vehicle 10 runs using the power stored in the battery pack 11.

[0018] like Figure 2 As shown in FIG. 1 , the battery pack 11 includes a battery pack 20 including a plurality of battery cells 22 (specifically, secondary cells) connected in series. The battery pack 20 stores power for driving the motor 13 and can supply power to the motor 13 via the PCU 12. In addition, the battery pack 20 is charged by receiving power generated by the motor 13 via the PCU 12 when the motor 13 regenerates power, such as when the vehicle 10 is braking. In addition, as shown in FIG. Figure 1 As shown, the battery pack 20 can be connected to an external charger CM provided outside the vehicle 10. The external charger CM is, for example, a fixed facility. The battery pack 20 is charged by the external charger CM.

[0019] The PCU 12 performs bidirectional power conversion between the battery pack 11 and the motor 13 based on a control signal from the vehicle ECU 14. The PCU 12 includes, for example, an inverter for driving the motor 13 and a converter for boosting a DC voltage supplied to the inverter to a voltage higher than the output voltage of the battery pack 11.

[0020] The motor 13 is an AC rotating electric machine, for example, a three-phase AC synchronous motor with a permanent magnet embedded in the rotor. The motor 13 is driven by the PCU 12 to generate a rotational driving force, and the driving force generated by the motor 13 is transmitted to the drive wheels of the vehicle 10. On the other hand, when the vehicle 10 brakes, the motor 13 acts as a generator to generate regenerative power. The power generated by the motor 13 is supplied to the battery pack 11 through the PCU 12 and stored in the battery pack 20 in the battery pack 11.

[0021] The vehicle ECU 14 includes a CPU, a ROM and a RAM, an input / output port for inputting and outputting various signals, etc. The CPU expands the program stored in the ROM to the RAM and executes it. The program stored in the ROM records the processing of the vehicle ECU 14. As an example of the main processing of the vehicle ECU 14, the vehicle ECU 14 receives information such as the voltage, current, SOC (State Of Charge) and SOH (State Of Health) of the battery pack 20 from the battery pack 11, and controls the driving of the motor 13 and the charging and discharging of the battery pack 11 by controlling the PCU 12.

[0022] Figure 2 1 is a diagram schematically showing the structure of the battery pack 11. The battery pack 11 includes a battery assembly 20, a plurality of battery monitoring devices 30, a battery control device 40, and a case 50 that accommodates them, and corresponds to a battery monitoring system in the present embodiment.

[0023] The battery pack 20 includes a plurality of battery blocks 21 connected in series. The battery block 21 may also be referred to as a battery stack or a battery module. Each battery block 21 has a plurality of battery cells 22. Each battery cell 22 is composed of a lithium-ion secondary battery or a nickel-metal hydride secondary battery. In addition, a lithium-ion secondary battery is a secondary battery that uses lithium as a charge carrier, and in addition to a conventional lithium-ion secondary battery in which the electrolyte is a liquid, it may also include a so-called all-solid-state battery that uses a solid electrolyte. In addition, the battery pack 20 may also include a plurality of battery blocks 21 connected in series, and each series connection is connected in parallel. In addition, the battery pack 20 is connected to the PCU 12 via a switch SW (e.g., a relay) and wiring 16.

[0024] The battery monitoring device 30 is also called a satellite battery module (SBM), and is provided for each battery block 21. Figure 2As shown, each battery monitoring device 30 includes a monitoring IC 31 as a monitoring unit, a slave-side wireless IC 32 as a wireless control unit, and a slave-side antenna 33 as a wireless antenna. The slave-side wireless IC 32 and the slave-side antenna 33 correspond to the "slave-side communication unit" of the battery monitoring device 30 for communicating with the battery control device 40. The monitoring IC 31 is also called a cell monitoring circuit (CSC) and acquires battery information from each battery cell 22 constituting the battery block 21 or a sensor not shown. The battery information includes, for example, voltage information, temperature information, and current information of each battery cell 22. In addition, the monitoring IC 31 performs self-diagnosis and generates self-diagnosis information. The self-diagnosis information is, for example, information related to the operation confirmation of the battery monitoring device 30, that is, information related to the abnormality or failure of the battery monitoring device 30. Specifically, it is information related to the operation confirmation of the monitoring IC 31 or the slave-side wireless IC 32 constituting the battery monitoring device 30.

[0025] The slave-side wireless IC 32 is connected to the monitoring IC 31 by wire, and has a wireless MCU (Micro Control Unit) and an RF device (high frequency device module), etc. The slave-side wireless IC 32 wirelessly transmits the data received from the monitoring IC 31 via the slave-side antenna 33. In addition, the slave-side wireless IC 32 transmits the data received via the slave-side antenna 33 to the monitoring IC 31.

[0026] The monitoring IC 31 includes a slave-side storage unit 34. The slave-side storage unit 34 is a non-transitory physical storage medium other than ROM (eg, a non-volatile memory other than ROM). The monitoring IC 31 stores the acquired battery information and self-diagnosis information in the slave-side storage unit 34.

[0027] The battery control device 40 is also called a battery ECU or a BMU (Battery Management Unit). The battery control device 40 is configured to be able to communicate wirelessly with each battery monitoring device 30. In detail, the battery control device 40 includes: a battery control MCU 41 as a battery control unit; a mother machine side wireless IC 42 as a wireless control unit; and a mother machine side antenna 43 as a wireless antenna. The mother machine side wireless IC 42 and the mother machine side antenna 43 are equivalent to the "mother machine side communication unit" of the battery control device 40 for communicating with the battery monitoring device 30. The battery control MCU 41 is composed of a microcomputer including a CPU, ROM, RAM, an input / output interface, etc. The CPU of the battery control MCU 41 expands the program stored in the ROM to the RAM and executes it. The program stored in the ROM records the processing related to battery control.

[0028] As an example of the main processing, the battery control MCU 41 instructs the battery monitoring device 30 to acquire and transmit the battery information. In addition, the battery control MCU 41 monitors the battery pack 20, the battery block 21, and the battery cell 22 based on the battery information received from the battery monitoring device 30. In addition, the battery control MCU 41 controls the switch SW based on the monitoring result, etc., and the switch SW switches the energization and de-energization state of the battery pack 20 and the PCU 12 or the motor 13. In addition, the battery control MCU 41 sometimes sends an equalization signal to equalize the voltage of each battery cell 22.

[0029] The base station side wireless IC 42 is wiredly connected to the battery control MCU 41, and has a wireless MCU and an RF device similar to the slave station side wireless IC 32. The base station side wireless IC 42 wirelessly transmits the data received from the battery control MCU 41 via the base station side antenna 43. In addition, the base station side wireless IC 42 transmits the data received via the base station side antenna 43 to the battery control MCU 41. In addition, as the base station side antenna 43 and the slave station side antenna 33, for example, a dipole antenna, a Yagi antenna, a slot antenna, an inverted F antenna, an inverted L antenna, a chip antenna, or a zero-order antenna (for example, a zero-order resonant antenna) can be used.

[0030] The battery control MCU 41 includes a host-side storage unit 44. The host-side storage unit 44 is a non-transitory physical storage medium other than a ROM (for example, a non-volatile memory other than a ROM).

[0031] A battery monitoring system is constructed including the battery pack 20 , the battery monitoring device 30 , the battery control device 40 , and a case 50 accommodating these as components.

[0032] Next, use Figure 3 and Figure 4 The case 50 and the arrangement of the battery blocks 21 and the like in the case 50 will be described. Figure 4 yes Figure 3 4-4 line section view. Figure 4 For the sake of convenience, some of the structures shown are not illustrated with hatching indicating cross sections.

[0033] The housing 50 includes a bottom plate 51 and a wall portion formed along the peripheral edge of the bottom plate 51. The bottom plate 51 is rectangular, specifically, rectangular. The wall portion includes a pair of first wall portions 52 extending along the short side direction of the bottom plate 51 and a pair of second wall portions 53 extending along the length direction of the bottom plate 51.

[0034] The housing 50 includes a cover 54. The cover 54 covers the first wall portion 52 and the second wall portion 53 from above. The cover 54 can be removed from the base portion composed of the bottom plate portion 51 and the wall portion. The cover 54 is fixed to the base portion by a fastening member such as a bolt. The bottom plate portion 51, the first wall portion 52, the second wall portion 53 and the inner surface of the cover 54 constitute a housing portion 55. The housing portion 55 has a continuous space for housing the battery block 21, the battery monitoring device 30 and the battery control device 40 in a predetermined configuration state.

[0035] In this embodiment, the bottom plate 51, the first wall 52, the second wall 53 and the cover 54 are configured to have an electromagnetic shielding effect of blocking or absorbing radio waves. For example, by being configured with a metal material (such as aluminum), a structure having an electromagnetic shielding effect is achieved.

[0036] In the present embodiment, the housing 50 is mounted on the vehicle 10 such that the long side direction of the housing 50 having a rectangular parallelepiped shape is the vehicle length direction of the vehicle 10. Figure 3 and Figure 4 In the figure, the long side direction of the housing 50 (the vehicle length direction of the vehicle 10) is shown as the X direction, the short side direction of the housing 50 (the vehicle width direction of the vehicle 10) is shown as the Y direction, and the height direction of the housing 50 is shown as the Z direction. For example, the lower surface of the bottom plate portion 51 becomes the installation surface relative to the body of the vehicle 10.

[0037] Each battery block 21 is in the shape of a rectangular parallelepiped and is composed of a plurality of battery cells 22 connected in series. In the present embodiment, the battery cells 22 are in the shape of a flat rectangular parallelepiped. Figure 5 As shown in (A), a plurality of battery cells 22 are stacked in a row along the short side direction of the housing 50. Figure 5 As shown in (B) of FIG. 5 , the plurality of battery cells 22 may be arranged and stacked along the longitudinal direction of the case 50. In addition, the plurality of battery cells 22 constituting each battery block 21 may be connected in parallel to each other.

[0038] like Figure 3 and Figure 4 As shown, each battery block 21 is arranged on the bottom plate portion 51 in such a manner that the long side direction is the short side direction of the housing 50. In this embodiment, for convenience, four battery blocks 21 are accommodated in the housing 50. Therefore, four battery monitoring devices 30 are also accommodated in the housing 50. Hereinafter, the battery blocks 21 will be referred to as the first battery block 21A to the fourth battery block 21D, and the battery monitoring device 30 will be referred to as the first battery monitoring device 30A to the fourth battery monitoring device 30D. In addition, in each battery block 21, the positive terminal and the negative terminal of the adjacent battery cells 22 are electrically connected by a bus bar.

[0039] In the housing portion 55, the junction box 15 is disposed on the bottom plate portion 51. The junction box 15 is in a rectangular parallelepiped shape and accommodates the switch SW. The junction box 15 is disposed side by side with the first battery block 21A so that the long side direction is parallel to the long side direction of the battery block 21. The height dimension of the junction box 15 is smaller than the height dimension of the battery block 21.

[0040] The battery control device 40 is arranged on the upper surface of the junction box 15. The battery monitoring device 30 is arranged on the upper surface of each battery block 21. In the housing portion 55, the arrangement position of the battery control device 40 is located at a position lower than the arrangement position of each battery monitoring device 30.

[0041] In this embodiment, the first battery monitoring device 30A monitors the first battery block 21A, the second battery monitoring device 30B monitors the second battery block 21B, the third battery monitoring device 30C monitors the third battery block 21C, and the fourth battery monitoring device 30D monitors the fourth battery block 21D.

[0042] The first battery monitoring device 30A to the fourth battery monitoring device 30D store the unique identification information assigned to themselves in the slave-side storage unit 34. When the first battery monitoring device 30A to the fourth battery monitoring device 30D transmit the identification information assigned to themselves, they transmit the battery information to the battery control device 40. Thus, the battery control device 40 can determine from which battery monitoring device the battery information is transmitted.

[0043] like Figure 6 As shown in FIG. 1 , the slave-side antenna 33 of each battery monitoring device 30 is configured to be able to select a radio wave directivity from a plurality of radio wave directivities having different central directions of the radio wave directivities. The slave-side antenna 33 of this embodiment is configured to be able to select a radio wave directivity from two radio wave directivities A and B. This configuration is a configuration for setting the radio wave directivity that is optimal for the battery control device 40 in each slave-side antenna 33.

[0044] use Figure 7 The following explains the reason for switching the directivity of radio waves. Figure 7 The figure shows the reception power of the wireless signal of the base station side antenna 43 when the wireless signal is transmitted from the slave side antenna 33 of the first battery monitoring device 30A to the base station side antenna 43 of the battery control device 40 . Figure 7 The horizontal axis represents the channel used for wireless communication, showing that the larger the channel, the higher the frequency. The frequency range defined by a channel is the range of "fc-Δf / 2" to "fc+Δf / 2" defined by the frequency center value fc of the channel and the channel width Δf. The high frequency side of the frequency range of the low frequency side channel and the low frequency side of the frequency range of the high frequency side channel of two adjacent channels may overlap.

[0045] in addition, Figure 7 The received power lower limit value Wmin shown is a threshold value indicating the lower limit of the received power that can transmit correct information between the battery monitoring device 30 and the battery control device 40. When the received power of the base station side antenna 43 is lower than the received power lower limit value Wmin, correct information cannot be transmitted between the battery monitoring device 30 and the battery control device 40.

[0046] When the radio wave directivity A is selected as the radio wave directivity of the slave side antenna 33, there is a channel in which the reception power of the base side antenna 43 is lower than the reception power lower limit value Wmin among the channels from the minimum channel (0ch) to the maximum channel (Nch) that can be used. The reason for this is described below.

[0047] like Figure 8 As shown in FIG. 1 , when the transmitting antenna AT and the receiving antenna AR are arranged in a housing formed of a metal wall, when a wireless signal is transmitted from the transmitting antenna AT, the transmitted signal is diffusely reflected in the housing. As a result, the main wave, which is a signal transmitted from the transmitting antenna AT and not reflected, interferes with the reflected wave, which is a signal transmitted from the transmitting antenna AT and then reflected. Fig. 9 As shown in FIG. 1 , the amplitude of the signal after interference becomes too small. As a result, there is a channel where the reception power of the base station side antenna 43 is lower than the reception power lower limit value Wmin. Fig. 9 In the example shown, the phase difference between the reflected wave and the main wave is approximately 180 degrees, and the reception power of the receiving antenna AR is excessively reduced.

[0048] On the other hand, Figure 7 As shown, when the radio wave directivity of the slave side antenna 33 is switched from radio wave directivity A to radio wave directivity B, in the channel where the received power of the base side antenna 43 is lower than the received power lower limit value Wmin, the received power of the base side antenna 43 becomes higher than the received power lower limit value Wmin. In addition, when switching to radio wave directivity B, the channel where the received power of the base side antenna 43 is lower than the received power lower limit value Wmin becomes a channel different from the channel when the radio wave directivity A is selected.

[0049] In this way, even if correct information cannot be transmitted between the battery monitoring device 30 and the battery control device 40 in a certain channel, by changing the radio wave directivity of the antenna, the received power can be set to be above the received power lower limit value Wmin, so that correct information can be transmitted between the battery monitoring device 30 and the battery control device 40.

[0050] Therefore, in the present embodiment, in the manufacturing process of the battery pack 11, the frequency characteristics of the received power (e.g., RSSI) of the battery control device 40 when wirelessly transmitting from each battery monitoring device 30 are measured for each of the radio wave directivities A and B. Then, based on the measured frequency characteristics, as shown in FIG. Fig.10 As shown, in each channel, it is determined which of the radio wave directivities A and B of each slave side antenna 33 provides the maximum reception power of the base side antenna 43 during wireless communication.

[0051] Fig.11 This is a flowchart of the process of generating mapping information that associates the radio wave directivity that maximizes the received power of the base station antenna 43 with each channel. This process is executed by the battery control MCU 41 of the battery control device 40 and the monitoring IC 31 of each battery monitoring device 30 during the manufacturing process of the battery pack 11.

[0052] In step S10, in any of the battery monitoring devices 30A to 30D, the monitoring IC 31 transmits a wireless signal when the radio wave directivity A is selected from the slave-side storage unit 34. Here, it is assumed that the first battery monitoring device 30A is selected. The wireless signal includes identification information of the battery monitoring device 30 as the transmission source.

[0053] In step S11, the transmitted wireless signal is received by the base station antenna 43. The battery control MCU 41 of the battery control device 40 calculates the frequency characteristics of the received power, which is information of the received power of the base station antenna 43 associated with each channel, based on the received signal. In step S12, the battery control MCU 41 associates the calculated frequency characteristics, the radio wave directivity A, and the identification information of the first battery monitoring device 30A, which is the transmission source of the wireless signal.

[0054] In step S13, the battery control MCU 41 determines whether the measurement of the received power corresponding to the radio wave directivities A and B is completed for the first battery monitoring device 30A. If it is determined that it is not completed, the battery control MCU 41 proceeds to step S14 and switches the radio wave directivity of the slave side antenna 33 of the first battery monitoring device 30A from the radio wave directivity A to the radio wave directivity B. Thereafter, through the processing of steps S10 to S12, the calculated frequency characteristics, the radio wave directivity B, and the identification information of the first battery monitoring device 30A are associated.

[0055] If the battery control MCU 41 determines that the process is completed in step S13, the process proceeds to step S15 to determine whether the measurement of the received power corresponding to the radio wave directivities A and B is completed for all the battery monitoring devices 30A to 30D. If the battery control MCU 41 determines that the process is not completed, the process proceeds to step S16 to switch the battery monitoring device as the transmission source of the wireless signal from the first battery monitoring device 30A to the second battery monitoring device 30B. After that, the calculated frequency characteristics, radio wave directivities, and identification information are associated with each of the second battery monitoring device 30B to the fourth battery monitoring device 30D through the processing of steps S10 to S16.

[0056] In step S17, the battery control MCU 41 generates mapping information (equivalent to "directivity information") that associates each channel, the radio wave directivity of the host side antenna 43 in each channel with the maximum received power, and the identification information of the battery monitoring device 30 based on the association information obtained by the processing of steps S10 to S16. Taking the first battery monitoring device 30A as an example, the mapping information includes information that the radio wave directivity of the slave side antenna 33 of the first battery monitoring device 30A is the radio wave directivity A or the radio wave directivity B when the received power of the master side antenna 43 is the maximum in each channel that can be used when wirelessly communicating with the first battery monitoring device 30A. For example, the mapping information includes information that the radio wave directivity with the maximum received power in the channel with a frequency center value of 2.40 GHz is the radio wave directivity B, and information that the radio wave directivity with the maximum received power in the channel with a frequency center value of 2.42 GHz is the radio wave directivity A.

[0057] The battery control MCU 41 stores the generated mapping information in the host-side storage unit 44 .

[0058] In step S18, the battery control MCU 41 transmits the generated mapping information to the first to fourth battery monitoring devices 30A to 30D from the base station antenna 43. In this case, in the channel for transmitting the mapping information, the radio wave directivity of each slave station antenna 33 is set to the radio wave directivity specified in the mapping information.

[0059] In step S19 , in each of the battery monitoring devices 30A to 30D, the monitoring IC 31 stores the mapping information received by the slave-side antenna 33 in the slave-side storage unit 34 .

[0060] According to the present embodiment described above, it is possible to determine the radio wave directivity with the maximum received power, that is, the radio wave directivity with the highest communication quality. In addition, after the battery pack 11 is shipped from the manufacturing plant, for example, it is not necessary to frequently generate mapping information.

[0061] In addition, even when the radio wave directivity of the slave side antenna 33 is set to any one of the radio wave directivities A and B, there may be a channel in each channel where the received power of the base side antenna 43 is lower than the received power lower limit value Wmin. In this case, the mapping information may include information prohibiting the use of the channel whose received power is lower than the received power lower limit value Wmin in wireless communication.

[0062] In addition, the mapping information may not be generated in the manufacturing process of the battery pack 11, but may be generated in advance when the battery pack 11 is designed. In this case, in the manufacturing process of the battery pack 11, the pre-generated mapping information may be stored in the master-side storage unit 44 and the slave-side storage unit 34 by a writing device provided in the production line. The received power used to generate the mapping information may be measured, for example, as follows.

[0063] The external measuring device is electrically connected to the battery control device 40 (specifically, for example, the base station side antenna 43) and the battery monitoring device 30 (specifically, for example, the slave station side antenna 33). In this connected state, the measuring device calculates the frequency characteristics of the received power of the base station side antenna 43 when the wireless signal is outputted from each battery monitoring device 30 individually. In detail, the measuring device measures the loss power (for example, through the characteristics) when the radio wave is propagated from the slave station side antenna 33 to the base station side antenna 43. The measuring device calculates the frequency characteristics of the received power of the base station side storage unit 44 by adding the transmission power from the slave station side antenna 33 and the loss power in the base station side wireless IC 42, the base station side antenna 43, the slave station side wireless IC 32 and the slave station side antenna 33 to the measured loss power.

[0064] Before each battery monitoring device 30 performs wireless communication with the battery control device 40, it determines whether to set the radio wave directivity of the slave side antenna 33 possessed by itself to one of the radio wave directivities A and B based on the mapping information. The channel used for wireless communication between the battery monitoring device 30 and the battery control device 40 may be set individually in each battery monitoring device 30A to 30D, or may be set to a common channel.

[0065] use Fig.12 , a switching process of the radio wave directivity executed by the monitoring IC 31 of each battery monitoring device 30 will be described.

[0066] In step S20 , mapping information is read from the slave-side storage unit 34 .

[0067] In step S21 , the read mapping information is referred to and one of the radio wave directivities A and B is selected as the radio wave directivity in the channel used for wireless communication with the battery control device 40 .

[0068] In step S22, the radio wave directivity of the slave-side antenna 33 is switched to the radio wave directivity associated with the channel used for wireless communication, that is, the radio wave directivity selected in step S21.

[0069] Next, use Figure 13 to Figure 15 , three examples of slave-side antennas that can change the direction of the center of radio wave directivity are described.

[0070] Fig.13 The first slave side antenna 33 is shown. The first example is a structure including a plurality of antenna members having different central directions of radio wave directivities and capable of switching the antenna member to be used.

[0071] The handset-side antenna 33 includes a circuit board 61 , a baseband IC 62 provided on a surface of the circuit board 61 , a switch 63 , various antenna components, and a power supply line electrically connecting the various antenna components and the switch 63 . Fig.13 A first antenna member 64A and a second antenna member 64B are shown as antenna members, and a first power supply line 65A and a second power supply line 65B are shown as power supply lines.

[0072] The baseband IC 62 communicates with the monitoring IC 31 via the slave-side wireless IC 32. The baseband IC 62 is connected to the first power supply line 65A or the second power supply line 65B via the switch 63. Fig.13 As shown in (A), when the baseband IC 62 and the first power supply line 65A are connected via the switch 63, the first antenna member 64A is used. In this case, the radio wave directivity is the radio wave directivity A. On the other hand, Fig.13 As shown in (B), when the baseband IC 62 and the second power supply line 65B are connected by the switch 63, the second antenna member 64B is used. In this case, the radio wave directivity is the radio wave directivity B.

[0073] Fig.14 The second slave-side antenna 33 is shown. The second example is a configuration in which the baseband IC 62 is individually connected to each power supply line and the operation of the baseband IC 62 can be switched.

[0074] The slave-side antenna 33 includes a circuit board 61 , a plurality of baseband ICs 62 provided on a surface of the circuit board 61 , a switch 63 , a plurality of antenna components, and a power supply line electrically connecting the plurality of antenna components and the baseband IC 62 . Fig.14 A first antenna member 64A and a second antenna member 64B are shown as antenna members, and a first power supply line 66A and a second power supply line 66B are shown as power supply lines.

[0075] Fig.15The third slave-side antenna 33 is shown. The third example is a structure in which the radio wave directivity is changed by changing the power supply point to the antenna member.

[0076] The handset-side antenna 33 includes a circuit substrate 61, a baseband IC 62, a switch 63, an antenna member 67, and first to fourth power supply lines 68A to 68D. The antenna member 67 and the first to fourth power supply lines 68A to 68D are provided on the board surface of the circuit substrate 61. The antenna member 67 is a zero-order resonant antenna, such as a patch antenna.

[0077] exist Fig.15 In the structure shown, the radio wave directivity can be changed into four types, and two of them are described below. Fig.15 As shown in (A), when the baseband IC 62 and the first power supply line 68A are connected via the switch 63, the radio wave directivity of the antenna member 67 is the radio wave directivity A. On the other hand, Fig.15 As shown in (B), when the baseband IC 62 and the fourth power supply line 68D are connected via the switch 63, the radio wave directivity of the antenna member 67 is the radio wave directivity B.

[0078] Here, the power supply lines 68A to 68D are arranged in parallel on the board surface of the circuit board 61. On the board surface of the circuit board 61, a conductive ground pattern indicated by hatching is provided between adjacent power supply lines 68A to 68D. The ground pattern is, for example, a grounding member of the baseband IC 62. Fig.15 In the illustrated example, a first ground pattern 69A is provided between the first power supply line 68A and the second power supply line 68B, a second ground pattern 69B is provided between the second power supply line 68B and the third power supply line 68C, and a third ground pattern 69C is provided between the third power supply line 68C and the fourth power supply line 68D.

[0079] The ground pattern is provided to make the radio wave directivity of the slave-side antenna 33 the target radio wave directivity. Fig.16 In the comparative example shown, no ground pattern is provided. In this case, the case where current flows through the first power supply line 68A is described as an example. Capacitive coupling occurs between the first power supply line 68A and the second power supply line 68B. In this case, part of the current flowing through the first power supply line 68A flows through the second power supply line 68B. As a result, the actual radio wave directivity of the slave side antenna 33 deviates from the target radio wave directivity.

[0080] In contrast, according to Fig.15 The structure provided with the ground pattern shown above can suppress the occurrence of capacitive coupling between adjacent power supply lines. As a result, it is possible to suppress the occurrence of a situation where the radio wave directivity deviates from the target radio wave directivity.

[0081] Incidentally, the feed line connected to the zero-order resonant antenna may be provided on a different layer in the multi-layer substrate. Fig.17 The multilayer substrate 70 shown includes a first layer 71A and a second layer 71B as a pair of surface layers and an intermediate layer 71C sandwiched by the pair of surface layers. Fig.15 A first power supply line 74A corresponding to the first power supply line 68A and a third power supply line 74C corresponding to the third power supply line 68C are provided between the second layer 71B and the intermediate layer 71C. A second power supply line 74B corresponding to the second power supply line 68B and a fourth power supply line 74D corresponding to the fourth power supply line 68D are provided between the second layer 71B and the intermediate layer 71C. In addition to the second power supply line 74B and the fourth power supply line 74D, an insulating layer 73 having electrical insulation is provided between the second layer 71B and the intermediate layer 71C.

[0082] In the first layer 71A, a ground pattern 75 is provided between the first feed line 74A and the third feed line 74C. In addition, a conductive ground pattern 72 is provided between the first layer 71A and the intermediate layer 71C. In this structure as well, deviation of the directivity of radio waves can be suppressed.

[0083] Next, the advantages of a structure capable of switching the directivity of radio waves will be described using two examples. The first example is an example of reusing the battery blocks 21 constituting the battery pack 11. The battery pack 11 of this embodiment is installed in the vehicle 10. The battery blocks 21 constituting the battery pack 11 can be reused for other purposes after being used for vehicle-mounted purposes. Fig.18 In the example shown, the battery pack 80 is reused from vehicle-mounted use to stationary use. In the housing 81 of the battery pack 80 constituting the stationary use, the arrangement of the battery blocks 21, the battery monitoring devices 30, the battery control device 40, and the junction box 15 is different from that of the vehicle-mounted use. In addition, the shape of the housing 81 for the stationary use is different from that of the housing 50 for the vehicle-mounted use.

[0084] Fig.19 The battery pack 11 is used in a vehicle. Fig.11 The processing generates the mapping information of the received power frequency characteristics. Fig.19 In the example shown, the radio wave directivities with the maximum received power in each channel are associated with each other.

[0085] on the other hand, Fig. 20The figure shows the frequency characteristics when the radio wave directivity of each channel is set based on the mapping information used in vehicle-mounted use when using a battery pack 80 having a battery block 21 that is reused as a stationary device. In the case of vehicle-mounted use, even if the received power in each channel is above the received power lower limit Wmin, if the use changes and the shape of the housing 81 or the configuration state in the housing 81 changes, the radio wave propagation path between the slave-side antenna 33 and the mother-side antenna 43 in the housing 81 will change significantly, so that there will be a channel where the received power is lower than the received power lower limit Wmin. In this way, when the battery is reused, at least one of the radio wave propagation path in the housing, the antenna configuration, and the radio wave directivity of the antenna becomes non-optimized, and the communication quality is reduced. As a result, for example, the antenna needs to be replaced when it is reused.

[0086] Here, even if the purpose of reuse is changed, by executing Fig.11 processing, such as Fig.21 As shown, in each channel, it is also possible to set the radio wave directivity that can make the reception power of the base station side antenna 43 be above the reception power lower limit value Wmin. After each battery block 21 to be reused, the battery monitoring device 3 and the battery control device 40 provided in each battery block 21 are inserted into the housing 81 as the reuse destination to manufacture the battery pack 80, when the battery control device 40 of the battery pack 80 is initially started, the execution Fig.11 Just process it.

[0087] Thus, according to this embodiment, correct information can be exchanged between the battery control device 40 and the battery monitoring device 30 through wireless communication without depending on the shell shape of the reuse destination or the configuration state of the storage components in the shell and without replacing the antenna on the slave side or the antenna on the master side during reuse.

[0088] The second example is an example of a case where the battery pack 11 is installed in the vehicle 10 after the battery pack 11 is shipped. The components of the battery pack 11 such as the battery monitoring device 30 may fail. In addition, the radio waves from the portable terminals used by the passengers in the vehicle 10 may become noise, and the communication environment of the vehicle 10 may change. In this case, if Fig. 22 As shown in FIG. 1 , there is a possibility that some of the channels become unusable and the received power in the available channels is lower than the received power lower limit value Wmin. Even in this case, by switching the radio wave directivity of the slave side antenna 33, as shown in FIG. Fig.23 As shown, the reception power can be set to be equal to or higher than the reception power lower limit value Wmin even in the available channels.

[0089] Fig.244 is a flowchart showing the steps of the switching process of the radio wave directivity corresponding to the second example. This process is executed by the battery control MCU 41.

[0090] In step S30 , it is determined whether there is an unusable channel among the channels used for wireless communication with the battery monitoring devices 30 .

[0091] If it is determined in step S30 that there is an unusable channel, the process proceeds to step S31 to determine whether the reception power of the base station side antenna 43 is lower than the reception power lower limit value Wmin in the usable channel.

[0092] If it is determined in step S31 that the received power is equal to or greater than the received power lower limit value Wmin, or if it is determined in step S30 that there is no unusable channel, the process proceeds to step S32 to permit wireless communication between the battery control device 40 and each battery monitoring device 30 .

[0093] On the other hand, if it is determined in step S31 that the received power is lower than the received power lower limit value Wmin, the process proceeds to step S33 and the radio wave directivity is switched. For example, if the current radio wave directivity is set to radio wave directivity A, it is switched to radio wave directivity B.

[0094] In step S34, after the radio wave directivity is switched, the base station side antenna 43 receives the wireless signal transmitted from the battery monitoring device 30 and measures the received power. Then, based on the received power, it is determined whether the received power of the base station side antenna 43 is greater than the received power lower limit value Wmin in the usable channel.

[0095] If it is determined in step S34 that the received power is greater than the received power lower limit Wmin, the process proceeds to step S32. On the other hand, if it is determined in step S34 that the received power is less than the received power lower limit Wmin, the process proceeds to step S35 and it is determined that wireless communication is not possible. Then, the upper control device is notified of the abnormality.

[0096] As described above, according to the present embodiment, even when the wireless communication environment deteriorates, for example, the stability of wireless communication can be improved.

[0097] <Modification of the first embodiment> The arrangement of the battery control device 40 and each battery monitoring device 30 in the housing portion 55 of the housing 50 is not limited to Figure 3 and Figure 4 For example, Fig.25As shown, the battery control device 40 may be mounted on the upper surface of the battery block 21, and the battery monitoring device may be mounted on each side surface of the battery block 21. Fig.25 In Figure 3 The battery block 21 and the like are more simply shown in the figure.

[0098] Part of the bottom plate 51, the first wall 52, the second wall 53, and the cover 54 may be a structure without electromagnetic shielding effect. For example, by being made of synthetic resin, the structure without electromagnetic shielding effect is achieved.

[0099] The slave-side antenna may also be selected from three or more radio wave directivities having different central directions of the radio wave directivities. In this case, in the channel used in the wireless communication between the master-side antenna and the slave-side antenna, a radio wave directivity other than the radio wave directivity in which the received power of the master-side antenna 43 during wireless transmission is the smallest among the radio wave directivities may be set. In addition, it is not limited to the radio wave directivity in which the received power of the master-side antenna 43 is the largest, and a radio wave directivity other than the radio wave directivity in which the received power is the smallest and the largest may be set. In addition, in a certain channel, when there are multiple radio wave directivities in which the received power is greater than the lower limit value Wmin of the received power, mapping information for setting multiple radio wave directivities that can be used in the channel may also be generated.

[0100] <Second embodiment> Hereinafter, the second embodiment will be described with reference to the accompanying drawings, focusing on the differences from the first embodiment. In this embodiment, instead of the slave-side antenna 33, the master-side antenna 43 included in the battery control device 40 has a structure capable of changing the radio wave directivity. Thus, the optimal radio wave directivity of the master-side antenna 43 is set for each battery monitoring device 30. In this embodiment, according to Figure 13 to Figure 15 As shown in the structure shown in the above, the base station side antenna 43 is configured to be able to switch the radio wave directivity to any one of the radio wave directivities A and B.

[0101] Fig.26 This is a flowchart of the process of generating mapping information that associates the radio wave directivity that maximizes the received power of the base station antenna 43 with each channel. This process is executed by the battery control MCU 41 of the battery control device 40 and the monitoring IC 31 of each battery monitoring device 30 during the manufacturing process of the battery pack 11.

[0102] In step S40, in each battery monitoring device 30A to 30D, the monitoring IC 31 transmits a wireless signal from the slave-side storage unit 34. The wireless signal includes identification information of the source battery monitoring device 30. For example, the transmission periods of the wireless signals of the battery monitoring devices 30A to 30D are set so as not to overlap.

[0103] In step S41, the transmitted wireless signal is received by the base station side antenna 43 set to the radio wave directivity A. The battery control MCU 41 calculates the frequency characteristics of the received power of the base station side antenna 43 for each battery monitoring device 30A to 30D based on the received signal. In step S42, the battery control MCU 41 associates the calculated frequency characteristics of the received power corresponding to each battery monitoring device 30A to 30D with the radio wave directivity A.

[0104] In step S43, the battery control MCU 41 determines whether the measurement of the received power corresponding to the radio wave directivities A and B on the base station side is completed. If it is determined that it is not completed, the battery control MCU 41 proceeds to step S44 and switches the radio wave directivity of the base station side antenna 43 from the radio wave directivity A to the radio wave directivity B. Thereafter, through the processing of steps S40 to S42, the frequency characteristics of the received power corresponding to each of the calculated battery monitoring devices 30A to 30D are associated with the radio wave directivity B.

[0105] When the battery control MCU 41 determines that step S43 is completed, it proceeds to step S45, and generates mapping information (equivalent to "directivity information") that associates each channel with the radio wave directivity in which the receiving power of the host side antenna 43 in each channel is the largest based on the association information obtained through the processing of steps S40 to S44. The battery control MCU 41 stores the generated mapping information in the host side storage unit 44.

[0106] In addition, the mapping information may not be generated in the manufacturing process of the battery pack 11, but may be generated in advance when the battery pack 11 is designed. In this case, in the manufacturing process of the battery pack 11, the pre-generated mapping information may be stored in the mother machine side storage unit 44 by a writing device provided in the production line.

[0107] use Fig. 27 , the switching process of the radio wave directivity executed by the battery control MCU 41 of the battery control device 40 is described.

[0108] In step S50, mapping information is read from the host-side storage unit 44. In step S51, one of the radio wave directivities A and B is selected as the radio wave directivity in the channel used for wireless communication with the battery control device 40, with reference to the read mapping information.

[0109] In step S52, the radio wave directivity of the base station side antenna 43 is switched to the radio wave directivity associated with the channel used for wireless communication, that is, the radio wave directivity selected in step S51.

[0110] According to the present embodiment described above, appropriate wireless communication can also be performed between the battery control device 40 and each battery monitoring device 30 .

[0111] <Modification of Second Embodiment> Instead of the received power of the base station antenna 43, mapping information that associates each channel with the radio wave directivity in which the received power of the slave station antenna 33 is the largest in each channel may be generated based on the received power of the slave station antenna 33. The mapping information is associated with each battery monitoring device 30 (each slave station antenna 33) and is generated individually. In describing the method of generating the mapping information, the battery control device 40 transmits a wireless signal from the base station antenna 43 set to the radio wave directivity A to each slave station antenna 33. In each of the battery monitoring devices 30A to 30D, the monitoring IC 31 calculates the frequency characteristic of the received power of the slave station antenna 33 based on the received signal of the slave station antenna 33, and associates the calculated frequency characteristic of the received power with the radio wave directivity A. In each of the battery monitoring devices 30A to 30D, the monitoring IC 31 transmits information that associates the frequency characteristic with the radio wave directivity A from the slave station antenna 33 to the base station antenna 43. The battery control MCU 41 receives the associated information through the main machine side antenna 43. Next, the battery control device 40 sends a wireless signal from the main machine side antenna 43 set to the radio wave directivity B to each sub-machine side antenna 33. Then, similarly to the case of radio wave directivity A, the battery control MCU 41 receives information associating the frequency characteristics and the radio wave directivity B through the main machine side antenna 43. Based on the associated information, the battery control MCU 41 generates mapping information associating each channel with the radio wave directivity in which the received power of the sub-machine side antenna 33 in each channel is the largest. By the way, the calculation of the frequency characteristics and the association of the frequency characteristics with the radio wave directivity may be performed in the battery control device 40 (battery control MCU 41) instead of in the battery monitoring device 30 (monitoring IC 31).

[0112] The antenna on the main machine side may also be configured to be able to select from three or more radio wave directivities with different center directions of the radio wave directivities. In this case, in the channel used in the wireless communication between the main machine side antenna and the sub-machine side antenna, a radio wave directivity other than the radio wave directivity in which the receiving power of the main machine side antenna 43 or the sub-machine side antenna 33 is the minimum when performing wireless transmission among the radio wave directivities may be set. In addition, it is not limited to the radio wave directivity in which the receiving power of the main machine side antenna 43 or the sub-machine side antenna 33 is the maximum, and it may also be set to a radio wave directivity other than the radio wave directivity in which the receiving power is the minimum and the maximum. In addition, in a certain channel, when there are multiple radio wave directivities with a receiving power greater than the receiving power lower limit value Wmin, mapping information for setting multiple radio wave directivities that can be used in the channel may also be generated.

[0113] In addition to the base station side antenna, the radio wave directivity of each of the slave station side antennas may be changed as in the first embodiment.

[0114] <Third Embodiment> Hereinafter, referring to the accompanying drawings, the third embodiment will be described with a focus on the differences from the first embodiment. Fig.18 As illustrated, when manufacturing the battery pack 80 as a recycled product, the optimal radio wave directivity of each slave-side antenna 33 is determined, and the battery state history information of each battery block 21 as a recycled product can be read.

[0115] Fig.28 The battery monitoring system, a portable terminal 300 (equivalent to a "testing device") applicable to the system, and an external server 310 are shown. Fig.28 For the sake of convenience, Figure 2 The same structures are denoted by the same symbols.

[0116] The portable terminal 300 is a device used by an operator to determine whether the battery block 21 can be reused or not. The portable terminal 300 includes a control unit 301 , a wireless IC 302 , an antenna 303 , an operation unit 304 , a display unit 305 , and a storage unit 306 .

[0117] The control unit 301 is mainly composed of a microcomputer and performs various processes. The wireless IC 302 is connected to the control unit 301 by wire, and has a wireless MCU and an RF device. The wireless IC 302 wirelessly transmits the data received from the control unit 301 via the antenna 303. In addition, the wireless IC 302 transmits the data received via the antenna 303 to the control unit 301. The storage unit 306 is a non-migrating physical recording medium other than the ROM (for example, a non-volatile memory other than the ROM).

[0118] The operation unit 304 is operated by an operator and is connected by wire to the control unit 301. The operation unit 304 is, for example, a touch panel, a touch display, hardware keys such as a keyboard, or a pointing device such as a mouse.

[0119] The display unit 305 is connected to the control unit 301 by wire, and is a device that outputs the processing results processed by the control unit 301. The display unit 305 is, for example, a touch panel or a touch display. The display unit 305 displays, for example, the history information of the battery status wirelessly transmitted from the battery monitoring device 30 mounted on the battery block 21.

[0120] The server 310 includes a control unit 311, a communication unit 312, and a storage unit 313. The control unit 311 is mainly composed of a microcomputer and performs various processes. The communication unit 312 is connected to the control unit 311 by wire. The communication unit 312 can communicate with the portable terminal 300 or the battery monitoring device 30 via the communication network 320. The communication network 320 is at least one of a wired network and a wireless network. The storage unit 313 is a non-migrating physical recording medium other than a ROM (for example, a non-volatile memory other than a ROM).

[0121] Fig.29 This is a flowchart of the generation process of mapping information that associates the radio wave directivity with each channel at which the receiving power of the main machine side antenna 43 is the maximum. This process is performed by the portable terminal 300, the battery control MCU 41, and the monitoring IC 31 of each battery monitoring device 30 in the manufacturing process of the battery pack 80 as a reusable product. This process is performed on the condition that the battery control device 40 and the portable terminal 300 are connected in a manner that can communicate (wireless communication or wired communication). In addition, Fig.29 For convenience, Fig.11 The same processes are denoted by the same symbols.

[0122] In step S60, the battery control MCU 41 determines whether there is a request to send the historical information of the battery status from the portable terminal 300. The request for the historical information is made by the operator connecting the portable terminal 300 and the battery control MCU 41 in a communication (wired or wireless) manner, and the request is sent from the portable terminal 300 to the battery control device 40 by operating the operation unit 304. When the battery control MCU 41 determines that there is a request to send, it proceeds to step S61 and sends the historical information of the battery status stored in the host side storage unit 44 to the portable terminal 300. The historical information includes at least one of the following (1) to (6). The information of (1) to (5) is information indicating the change of the status of the battery block 21 over time, and the information of (6) is information that does not depend on the usage history of the battery block 21.

[0123] (1) Temperature history information indicating the temperature change of the battery block over time; (2) voltage history information representing the voltage variation of the battery block over time; (3) Current history information representing the current variation of the battery block over time; (4) information for determining the health of the battery block, which is at least one of the SOC, SOH, remaining capacity, self-discharge rate change information, and internal resistance of the battery block; (5) information for determining the expected life of the battery block, which is at least one of the manufacturing date, the use start date, the energy processing capacity, and the capacity processing capacity of the battery block; (6) Information related to an economic operator that puts the battery pack on the market, and at least one of the manufacturer of the battery pack, the model of the battery pack, the manufacturing site, the year, month and day of manufacturing, the rated capacity, the minimum voltage, the rated voltage, the maximum voltage and the operating temperature range. As a result, the history information of the battery state is displayed on the display unit 305 of the portable terminal 300. The operator can understand the state of the battery block 21 based on the displayed information.

[0124] After the process of step S61 is completed, the processes of steps S10 to S19 are executed. Thus, mapping information that specifies the optimal radio wave directivity of each slave-side antenna 33 is generated in the battery pack 80 that is a recycled product.

[0125] According to the present embodiment described above, when manufacturing the battery pack 80 as a recycled product, the optimum radio wave directivity of each slave-side antenna 33 can be determined, and the state of each battery block 21 as a recycled product can be grasped.

[0126] <Modification of the Third Embodiment> All or part of the historical information of (1) to (6) above may be stored in the storage unit 313 of the server 310. The historical information is periodically transmitted from the battery monitoring device 30 to the server 310 via the communication network 320, so that the historical information of the storage unit 313 of the server 310 is periodically updated. The portable terminal 300 may receive all or part of the information of (1) to (6) above from the server 310 via the communication unit 312, the communication network 320, and the wireless IC 302.

[0127] When the battery blocks 21 are recycled, the status of each battery block 21 as a recycled product can be grasped by sending information from the server 310 to the portable terminal 300. If the server 310 implements a data tampering prevention measure such as a blockchain, highly reliable historical information can be obtained.

[0128] It is also desirable that the history information stored in the storage unit 313 of the server 310 is information with a low update frequency, such as the information (6) described above.

[0129] <Fourth embodiment> Hereinafter, the fourth embodiment will be described with reference to the accompanying drawings, focusing on the differences from the first embodiment. The setting process of the radio wave directivity is not limited to the manufacturing process of the battery pack 11, but can also be performed after the vehicle 10 arrives at the hands of the user. In this embodiment, the setting process of the radio wave directivity is allowed to be performed when the vehicle 10 is in a parked state or when the battery pack 20 is charged by the external charger CM.

[0130] Fig.30 4 is a flowchart of the generation process of mapping information that associates the radio wave directivity of the base station side antenna 43 with each channel at the maximum received power. This process is executed by the battery control MCU 41 of the battery control device 40 and the monitoring IC 31 of each battery monitoring device 30. Fig.30 For convenience, Fig.11 The same processes are denoted by the same symbols.

[0131] In step S70, the battery control MCU 41 determines whether one of the first condition that the vehicle 10 is parked or the second condition that the battery pack 20 installed in the parked vehicle 10 is charged by the external charger CM is satisfied. The process of step S70 is a process for improving the measurement accuracy of the received power of the base station side antenna 43.

[0132] Due to vibrations etc. generated by the travel of the vehicle 10, the frequency characteristics of the wireless signal received by the base station side antenna 43 may change. In this case, the accuracy of the mapping information that associates the radio wave directivity with each channel at which the received power of the base station side antenna 43 is the maximum may be reduced, or the time required to generate the mapping information may be prolonged. Therefore, it is desirable to perform the measurement of the received power without generating vibrations etc. Therefore, the first condition is set. In addition, for example, when it is determined that the switch that allows the vehicle 10 to travel or instructs the start, that is, the start switch or the ignition switch operated by the user is turned off, it is determined that the first condition is met.

[0133] When the battery pack 20 is charged by the external charger CM, the vehicle 10 is also in a stopped state, which is a situation where no vibration etc. is generated. In view of this point, the second condition is set.

[0134] If the battery control MCU 41 determines that neither the first condition nor the second condition is satisfied, it does not execute the mapping information generation process. On the other hand, if the battery control MCU 41 determines that either the first condition or the second condition is satisfied, it proceeds to step S71 to determine whether the specific condition is satisfied. The specific condition is used to determine whether the radio wave propagation path between the main unit side antenna 43 and each sub-unit side antenna 33 in the housing 50 passes through the manufacturing process of the battery pack 11. Fig.11 The processing measures the condition that the radio wave propagation path has changed significantly under the condition of receiving power. The specific condition can be, for example, Fig.31 The conditions of (A) to (C).

[0135] (A) The condition that the driving distance of the vehicle 10 (for example, the cumulative driving distance) exceeds the determination distance Lth. When the driving distance becomes longer, the bolts for fixing the cover 54 to the base portion of the housing 50 may become loose, and the space of the housing 55 may change. In this case, the radio wave propagation path changes significantly, and the frequency characteristics of the received power of the base machine side antenna 43 may change significantly. In addition, in order to periodically perform the mapping information generation process, the determination distance Lth is increased in stages each time the driving distance exceeds the determination distance Lth. In addition, the driving time (cumulative driving time) may be used instead of the driving distance.

[0136] (B) The temperature of the battery block 21 exceeds the determination temperature. When the battery block 21 reaches a high temperature, the radio wave propagation path may change significantly due to thermal expansion of the housing 50, etc. In addition, the determination temperature is set to a value higher than the temperature of the battery block 21 under the condition where the received power is measured in the manufacturing process of the battery pack 11.

[0137] (C) The user of the vehicle 10 operates the vehicle air conditioning device, for example, changes the set temperature of the vehicle interior. The user operates the air conditioning device in such a way that the temperature around the battery pack 11 may deviate from the temperature at the time of manufacturing the battery pack 11, and the radio wave propagation path may change significantly.

[0138] When the battery control MCU 41 determines that the specific condition is satisfied, the process of step S10 is executed. Here, the battery control MCU 41 may send a command to send a wireless signal from the slave side antenna 33 from the main unit side antenna 43 to the slave side antenna 33. When the monitoring IC 31 of the battery monitoring device 30 determines that the command has been received, it sends a wireless signal from the slave side antenna 33.

[0139] In step S11, the detection unit may detect and measure the temperature, humidity, and air pressure of the storage unit 55 when receiving power, and the temperature, humidity, and air pressure may be associated with the radio wave directivity and the like in the mapping information.

[0140] According to the present embodiment described above, since the radio wave directivity in each channel is set according to the change in the radio wave propagation path, the quality of the wireless communication between the battery monitoring device 30 and the battery control device 40 can be improved.

[0141] <Fifth Embodiment> Hereinafter, the fifth embodiment will be described with reference to the drawings, focusing on the differences from the fourth embodiment. In the present embodiment, when the vehicle 10 is traveling, the execution of the setting process of the radio wave directivity is permitted.

[0142] Fig.32 4 is a flowchart of the generation process of mapping information that associates the radio wave directivity of the base station side antenna 43 with each channel at the maximum received power. This process is executed by the battery control MCU 41 of the battery control device 40 and the monitoring IC 31 of each battery monitoring device 30. Fig.32 For convenience, Fig.11 The same processes are denoted by the same symbols.

[0143] In step S80, the battery control MCU 41 determines whether a specific condition is satisfied during the driving of the vehicle 10. The process of step S80 is a process for improving the measurement accuracy of the received power of the base unit side antenna 43. The specific condition is a condition for determining whether a significant change has occurred in the radio wave propagation path between the base unit side antenna 43 and each sub-unit side antenna 33 during driving, for example, a condition that can detect that the vibration generated accompanying driving has increased, or the noise in the storage unit 55 has increased. The specific condition is, for example, a condition that the current flowing through the battery pack 20 exceeds the determination current, or a condition that the vibration detected by the acceleration sensor that detects the acceleration of the vehicle 10 exceeds the determination value.

[0144] When the battery control MCU 41 determines that the specific condition is satisfied, the process of step S10 is executed.

[0145] According to the present embodiment described above, even when the radio wave propagation path changes while the vehicle 10 is traveling, the quality of wireless communication between the battery monitoring device 30 and the battery control device 40 can be improved.

[0146] <Sixth embodiment> Hereinafter, the sixth embodiment will be described with reference to the drawings, focusing on the differences from the fourth and fifth embodiments. In this embodiment, when an abnormality occurs in the battery pack 11, the map information is updated.

[0147] Fig.33 FIG. 1 shows the battery pack 11 in an abnormal state. Fig.33 For convenience, Figure 3 and Figure 4 The same structures or corresponding structures as shown in the above are marked with the same symbols. Fig.33 In the example shown, the configuration position of the first battery block 21A is deviated from the normal configuration position. In this case, the radio wave propagation path between the battery control device 40 and each battery monitoring device 30A to 30D changes significantly, and the frequency characteristics of the power received by the host side antenna 43 may deviate significantly from the frequency characteristics measured in the manufacturing process of the battery pack 11.

[0148] Therefore, in the present embodiment, when it is determined that the radio wave propagation path has changed significantly, the mapping information is generated and updated again.

[0149] Fig.34 4 is a flowchart of the generation process of mapping information that associates the radio wave directivity of the base station side antenna 43 with each channel at the maximum received power. This process is executed by the battery control MCU 41 of the battery control device 40 and the monitoring IC 31 of each battery monitoring device 30. Fig.34 For convenience, Fig.11 The same processes are denoted by the same symbols.

[0150] In step S90, the battery control MCU 41 determines whether an abnormality has occurred in the battery pack 11 (for example, abnormal deformation of the battery pack 11). The abnormality of the battery pack 11 includes, in addition to the abnormality that the configuration state of each battery block 21, each battery monitoring device 30, and the battery control device 40 in the storage section 55 deviates from the prescribed configuration state, the detachment of the cover 54 relative to the base portion of the housing 50, the voltage abnormality of the battery cells 22 constituting the battery block 21, the infiltration of water into the battery block 21, the detection of smoke in the storage section 55, and the operation of the airbag device included in the vehicle. The prescribed configuration state is, for example, the configuration state of each battery block 21, each battery monitoring device 30, and the battery control device 40 in the storage section 55 of the mass-produced battery pack 11.

[0151] When the battery control MCU 41 determines that an abnormality has occurred, the process of step S10 is executed.

[0152] According to the present embodiment described above, even when an abnormality occurs in the battery pack 11 , it is possible to suppress the degradation of the quality of wireless communication between the battery monitoring device 30 and the battery control device 40 as much as possible.

[0153] <Seventh embodiment> Hereinafter, the seventh embodiment will be described with reference to the accompanying drawings, centering on the differences from the first embodiment. In this embodiment, when generating mapping information, the received power is not used, but the communication error rate when wireless communication is performed between the base station side antenna 43 and the slave station side antenna 33 is used. The communication error rate is, for example, a packet error rate or a bit error rate.

[0154] In the present embodiment, in the manufacturing process of the battery pack 11, when wireless transmission is performed from each battery monitoring device 30 for each of the radio wave directivities A and B, as shown in FIG. Fig.35 As shown, the communication error rate of each channel is measured. Then, based on the measured communication error rate, the radio wave directivity A and B of each slave side antenna 33 in each channel is determined, in which the communication error rate during wireless communication is less than the threshold value Eth. At this time, the radio wave directivity with a communication error rate exceeding the threshold value Eth is not used.

[0155] exist Fig.35 In the illustrated example, the radio wave directivity A is associated in the first channel, the radio wave directivity B is associated in the second channel, and the radio wave directivities A and B are associated in the third channel.

[0156] Fig.36 This is a flowchart of a process for generating mapping information that associates radio wave directivity with each channel. This process is executed by the battery control MCU 41 of the battery control device 40 and the monitoring IC 31 of each battery monitoring device 30 in the manufacturing process of the battery pack 11 .

[0157] In step S100, in any of the battery monitoring devices 30A to 30D, the monitoring IC 31 transmits a wireless signal when the radio wave directivity A is selected from the slave-side storage unit 34. Here, it is assumed that the first battery monitoring device 30A is selected. The wireless signal includes identification information of the battery monitoring device 30 as the transmission source.

[0158] In step S101, the transmitted wireless signal is received by the base station antenna 43. The battery control MCU 41 measures the communication error rate based on the received signal. In step S102, the battery control MCU 41 associates the measured communication error rate, the radio wave directivity A, and the identification information of the first battery monitoring device 30A as the transmission source of the wireless signal.

[0159] In step S103, the battery control MCU 41 determines whether the measurement of the communication error rate corresponding to the radio wave directivities A and B is completed for the first battery monitoring device 30A. If the battery control MCU 41 determines that the measurement is not completed, it proceeds to step S104 and switches the radio wave directivity of the slave side antenna 33 of the first battery monitoring device 30A from the radio wave directivity A to the radio wave directivity B. Thereafter, through the processing of steps S100 to S102, the measured communication error rate, the radio wave directivity B, and the identification information of the first battery monitoring device 30A are associated.

[0160] If the battery control MCU 41 determines that the communication error rate corresponding to the radio wave directivity A and B is completed for all the battery monitoring devices 30A to 30D in step S103, the battery control MCU 41 proceeds to step S105. If the battery control MCU 41 determines that the communication error rate is not completed, the battery control MCU 41 proceeds to step S106, and switches the battery monitoring device as the transmission source of the wireless signal from the first battery monitoring device 30A to the second battery monitoring device 30B. After that, through the processing of steps S100 to S106, the measured communication error rate, radio wave directivity, and identification information are associated with each of the second battery monitoring device 30B to the fourth battery monitoring device 30D.

[0161] In step S107, the battery control MCU 41 generates mapping information (equivalent to "directivity information") that associates each channel, the radio wave directivity with a communication error rate below the threshold value Eth in each channel, and the identification information of the battery monitoring device 30 based on the association information obtained by the processing of steps S100 to S106. The battery control MCU 41 stores the generated mapping information in the host side storage unit 44. Here, in each channel, the radio wave directivity with the smallest communication error rate among the radio wave directivities A and B can also be associated.

[0162] In step S108, the battery control MCU 41 transmits the generated mapping information from the main unit side antenna 43 to the first battery monitoring device 30A to the fourth battery monitoring device 30D. In this case, in the channel used for transmitting the mapping information, the radio wave directivity of each slave unit side antenna 33 is set to the radio wave directivity specified in the mapping information. In step S109, in each battery monitoring device 30A to 30D, the monitoring IC 31 stores the mapping information received by the slave unit side antenna 33 in the slave unit side storage unit 34.

[0163] According to the present embodiment described above, it is possible to obtain the same effects as those of the first embodiment. Incidentally, in the present embodiment, the configurations of the second to seventh embodiments can also be applied.

[0164] <Eighth Embodiment> Hereinafter, the eighth embodiment will be described with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, when generating mapping information, the difference between the received power and the noise floor is used instead of the received power.

[0165] In the present embodiment, in the manufacturing process of the battery pack 11, for each of the radio wave directivities A and B, the above-mentioned difference is measured when wireless transmission is performed from each battery monitoring device 30. Then, based on the measured difference, the radio wave directivity whose difference between the radio wave directivities A and B is greater than the threshold value Wth is determined in each channel. The larger the difference, the greater the noise immunity margin of the communication. Therefore, in each channel, the radio wave directivity whose difference is less than the threshold value Wth is not used.

[0166] Fig.37 The figure shows the frequency characteristic of the difference between the received power of the base station side antenna 43 and the background noise when the radio wave directivity of the slave station side antenna 33 is set to the radio wave directivity A and wireless transmission is performed. Fig.38 The case where the radio wave directivity of the slave side antenna 33 is set to the radio wave directivity B is shown.

[0167] exist Fig.37 and Fig.38 In the example shown, in the first channel, the difference ΔW corresponding to the radio wave directivity A is 25 dBm, and the difference ΔW corresponding to the radio wave directivity B is 17 dBm. When the threshold value Wth is 20 dBm, the radio wave directivity A is associated with the first channel.

[0168] In the second channel, the difference ΔW corresponding to the radio wave directivity A is 23 dBm, and the difference ΔW corresponding to the radio wave directivity B is 25 dBm. Therefore, in the second channel, the radio wave directivities A and B are linked.

[0169] In the third channel, the difference ΔW corresponding to the radio wave directivity A is 15 dBm, and the difference ΔW corresponding to the radio wave directivity B is 30 dBm. Therefore, in the third channel, the radio wave directivity B is associated.

[0170] Fig.39 This is a flowchart of a process for generating mapping information that associates radio wave directivity with each channel. This process is executed by the battery control MCU 41 of the battery control device 40 and the monitoring IC 31 of each battery monitoring device 30 in the manufacturing process of the battery pack 11 .

[0171] In step S120, in any of the battery monitoring devices 30A to 30D, the monitoring IC 31 transmits a wireless signal when the radio wave directivity A is selected from the slave-side storage unit 34. Here, it is assumed that the first battery monitoring device 30A is selected. The wireless signal includes identification information of the battery monitoring device 30 as the transmission source.

[0172] In step S121, the transmitted wireless signal is received by the base station side antenna 43. The battery control MCU 41 measures the difference ΔW between the received power and the background noise based on the received signal. The background noise information used in the measurement of the difference ΔW may be stored in advance in the base station side storage unit 44, for example. In step S122, the battery control MCU 41 associates the measured difference ΔW, the radio wave directivity A, and the identification information of the first battery monitoring device 30A as the transmission source of the wireless signal.

[0173] In step S123, the battery control MCU 41 determines whether the measurement of the difference ΔW corresponding to the radio wave directivities A and B is completed for the first battery monitoring device 30A. If it is determined that the measurement is not completed, the battery control MCU 41 proceeds to step S124 and switches the radio wave directivity of the slave-side antenna 33 of the first battery monitoring device 30A from the radio wave directivity A to the radio wave directivity B. Thereafter, through the processing of steps S120 to S122, the measured difference ΔW, the radio wave directivity B, and the identification information of the first battery monitoring device 30A are associated.

[0174] If the battery control MCU 41 determines that the process is completed in step S123, the process proceeds to step S125 to determine whether the measurement of the difference ΔW corresponding to the radio wave directivities A and B is completed for all the battery monitoring devices 30A to 30D. If the battery control MCU 41 determines that the process is not completed, the process proceeds to step S126 to switch the battery monitoring device as the transmission source of the wireless signal from the first battery monitoring device 30A to the second battery monitoring device 30B. After that, through the processing of steps S120 to S126, the measured difference ΔW, the radio wave directivity, and the identification information are associated with each of the second battery monitoring device 30B to the fourth battery monitoring device 30D.

[0175] In step S127, the battery control MCU 41 generates mapping information (equivalent to "directivity information") that associates each channel, the radio wave directivity whose difference ΔW in each channel is greater than the threshold value Wth, and the identification information of the battery monitoring device 30 based on the association information obtained by the processing of steps S120 to S126. The battery control MCU 41 stores the generated mapping information in the host side storage unit 44. Here, in each channel, the radio wave directivity whose difference ΔW between the radio wave directivities A and B is the largest can also be associated.

[0176] In step S128, the battery control MCU 41 transmits the generated mapping information from the main unit side antenna 43 to the first battery monitoring device 30A to the fourth battery monitoring device 30D. In this case, in the channel used for transmitting the mapping information, the radio wave directivity of each slave unit side antenna 33 is set to the radio wave directivity specified in the mapping information. In step S129, in each battery monitoring device 30A to 30D, the monitoring IC 31 stores the mapping information received by the slave unit side antenna 33 in the slave unit side storage unit 34.

[0177] According to the present embodiment described above, even when the reception power lower limit value Wmin differs for each channel, the quality of wireless communication between the battery control device 40 and the battery monitoring device 30 can be improved. Incidentally, the configurations of the second to seventh embodiments can also be applied to the present embodiment.

[0178] <Ninth embodiment> Below, refer to Fig.40 and Fig.41 The ninth embodiment will be described with the focus on the differences from the above-mentioned embodiments. Fig.40 and Fig.41 In the present invention, for convenience, the same symbols are used for the same structures or corresponding structures as those described in the above embodiments. Fig.41 yes Fig.40 Sectional view along line 41-41.

[0179] The vehicle includes a chassis 100 as a vehicle body made of metal material and wheels 110. The chassis 100 includes a chassis bottom plate portion 101, a side plate portion 102, a chassis top plate portion 103 and an end plate portion 104 extending in the vehicle length direction. The side plate portion 102 extends upward from an end portion of the chassis bottom plate portion 101 in the vehicle width direction. The chassis top plate portion 103 covers the side plate portion 102 from above. The end plate portion 104 covers both ends of the chassis bottom plate portion 101, the side plate portion 102 and the chassis top plate portion 103. The inner surfaces of the chassis bottom plate portion 101, the side plate portion 102, the chassis top plate portion 103 and the end plate portion 104 constitute a housing portion 105 for housing the battery pack 11.

[0180] The bottom plate portion 51 constituting the housing 50 is arranged on the chassis bottom plate portion 101. A space is formed between the chassis top plate portion 103 and the cover 54 constituting the housing 50. In the present embodiment, the bottom plate portion 51, the first wall portion 52, the second wall portion 53 and the cover 54 are made of synthetic resin, and thus have a structure without an electromagnetic shielding effect. Therefore, the radio waves transmitted from the main machine side antenna 43 and / or the slave machine side antenna 33 pass through the housing 50. However, the radio waves are reflected by the chassis 100 made of a metal material.

[0181] Incidentally, a part of the bottom plate portion 51 , the first wall portion 52 , the second wall portion 53 , and the cover 54 (for example, the cover 54 ) may be formed of a synthetic resin.

[0182] In the present embodiment described above, diffuse reflection of radio waves also occurs in the storage unit 105. In addition, the communication environment of the storage unit 105 may also change due to reuse, etc. Therefore, the configuration described in each of the above embodiments can be applied.

[0183] <Tenth embodiment> Below, refer to Fig.42 The tenth embodiment will be described with the focus on the differences from the ninth embodiment. Fig.42 In the present invention, for convenience, the same symbols are used to mark the same structures as or corresponding structures described in the above embodiments.

[0184] The battery control device 40 is arranged outside the housing 50 in the housing portion 105 . Specifically, the battery control device 40 is attached to the upper surface of the cover 54 .

[0185] In this embodiment, the cover 54, the first wall 52, the second wall 53 and the bottom plate 51 are made of metal. In order to communicate between the battery monitoring devices 30A to 30D housed in the housing 50 and the battery control device 40, a structure is required to connect the inside and outside of the housing 50.

[0186] As a communication connection structure, the battery pack 11 of the present embodiment includes a relay device 120. The relay device 120 includes: an antenna 120a located on the upper surface side of the cover 54; and a shaft portion 120b extending downward from the antenna 120a and having an outer diameter smaller than that of the antenna 120a. A through hole 54a for inserting the shaft portion 120b is formed in the cover 54. In the present embodiment, the through holes 54a are arranged in a row in the cover 54 along the long side direction of the cover 54. The relay device 120 is configured in a state where the antenna 120a is located on the upper surface side of the cover 54 and the shaft portion 120b is inserted into the through hole 54a formed in the cover 54. The relay device 120 is independently provided corresponding to each battery monitoring device 30. In addition, the antenna 120a may also be covered by a cover that transmits radio waves.

[0187] The through hole 54a is blocked by the antenna 120a of the relay device 120. In addition, a sealing member may be interposed between the antenna 120a and the upper surface of the cover 54.

[0188] The slave-side wireless IC 32 and antenna 120a of the battery monitoring device 30 are electrically connected via a communication wiring provided on the shaft 120b. This enables wireless communication between the battery monitoring device 30 and the battery control device 40 via the antenna 120a and the master-side antenna 43.

[0189] In the present embodiment described above, diffuse reflection of radio waves also occurs in the storage unit 105. In addition, the communication environment of the storage unit 105 may also change due to reuse, etc. Therefore, the configuration described in each of the above embodiments can be applied.

[0190] <Eleventh Embodiment> Below, refer to Fig.43 , the eleventh embodiment will be described with the focus on the differences from the ninth embodiment. Fig.43 In the present invention, for convenience, the same symbols are used to mark the same structures as or corresponding structures described in the above embodiments.

[0191] The battery control device 40 is mounted on the upper surface of the junction box 15 in the housing 50. On the other hand, the first to fourth battery monitoring devices 30A to 30D are arranged outside the housing 50 in the housing portion 105, and more specifically, are mounted on the upper surface of the cover 54. At this time, in order to communicate between the battery control device 40 accommodated in the housing 50 and the battery monitoring devices 30A to 30D arranged outside the housing 50, a structure for communicatingly connecting the inside and outside of the housing 50 is required.

[0192] As a communication connection structure, the battery pack 11 of the present embodiment includes a relay device 130. The relay device 130 includes: a connection portion 130b located on the upper surface side of the cover 54; and an antenna 130a extending downward from the connection portion 130b. A through hole 54a for inserting the antenna 130a is formed in the cover 54. The through holes 54a are arranged in a row in the cover 54 along the long side direction of the cover 54. The relay device 130 is independently provided corresponding to each battery monitoring device 30. In addition, the antenna 130a may also be covered by a cover that transmits radio waves.

[0193] The through hole 54a is blocked by the connection portion 130b of the relay device 130. In addition, a sealing member may be interposed between the connection portion 130b and the upper surface of the cover 54.

[0194] The slave-side wireless IC 32 and antenna 130a of the battery monitoring device 30 are electrically connected via a communication wiring provided in the connection portion 130b. This enables wireless communication between the battery monitoring device 30 and the battery control device 40 via the antenna 130a and the master-side antenna 43.

[0195] In the present embodiment described above, diffuse reflection of radio waves also occurs in the storage unit 105. In addition, the communication environment of the storage unit 105 may also change due to reuse, etc. Therefore, the configuration described in each of the above embodiments can be applied.

[0196] <Twelfth embodiment> Below, refer to Fig.44 The twelfth embodiment will be described with the focus on the differences from the above-mentioned embodiments. Fig.44 In the present invention, for convenience, the same symbols are used to mark the same structures as or corresponding structures described in the above embodiments.

[0197] like Fig.44 As shown, the case 50 may not be included, and the battery blocks 21A to 21D, the battery monitoring devices 30A to 30D, and the battery control device 40 may be directly accommodated in the accommodating portion 105 of the chassis 100. This structure is called MTP (Module to Platform).

[0198] In the present embodiment described above, diffuse reflection of radio waves also occurs in the storage unit 105. In addition, the communication environment of the storage unit 105 may also change due to reuse, etc. Therefore, the configuration described in each of the above embodiments can be applied.

[0199] <Other embodiments> In addition, each of the above-mentioned embodiments may be implemented with the following modifications.

[0200] In the above-mentioned embodiments, a structure is adopted in which a plurality of battery cells are assembled into a battery block and each battery block is connected in series. Instead of this structure, a so-called CTP (Cell to Pack) structure may be adopted in which a plurality of battery cells connected in series are accommodated in the accommodation portion 105 of the chassis 100 without making a battery block. Fig.45 An example of this is shown in FIG. Fig.45 In the example shown, a plurality of long battery cells 200 that are long in the vehicle width direction are housed in the housing portion 105. The positive terminal 201 of one of the adjacent battery cells 200 and the negative terminal 202 of the other are electrically connected via a bus bar (not shown). In this case, for example, a battery monitoring device may be independently provided corresponding to each battery cell 200.

[0201] In place of the CTP structure, a so-called CTC (Cell to Chassis) structure may be adopted in which a housing portion for housing a battery cell is formed in the chassis of the vehicle and a plurality of battery cells are housed in the housing portion.

[0202] Even in the case of a CTP or CTC structure, radio waves are reflected by at least a portion of the receiving section. In addition, the communication environment of the receiving section may also change due to reuse, etc. Therefore, there is an advantage of being applicable to the structure described in the above embodiments.

[0203] The configuration in which the base station side antenna 43 can change the radio wave directivity described in the second embodiment can be applied to each embodiment after the fourth embodiment.

[0204] The mobile object on which the battery monitoring system is installed is not limited to a vehicle, and may be, for example, an airplane or a ship. Furthermore, the control system is not limited to a system installed on a mobile object, and may be a fixed system.

[0205] ·The control unit and method described in the present disclosure may also be implemented by a special-purpose computer, which is provided by constituting a processor and a memory, and the above-mentioned processor is programmed to execute one or more functions embodied by a computer program. Alternatively, the control unit and method described in the present disclosure may be implemented by a special-purpose computer, which is provided by constituting a processor composed of one or more special-purpose hardware logic circuits. Alternatively, the control unit and method described in the present disclosure may be implemented by one or more special-purpose computers, which are constituted by a combination of a processor and a memory programmed to execute one or more functions and a processor constituted by one or more hardware logic circuits. In addition, the computer program may also be stored in a computer-readable non-temporary tangible storage medium as an instruction executed by a computer.

[0206] Hereinafter, characteristic structures extracted from the above-mentioned embodiments will be described. [Structure 1] A battery monitoring system, the battery monitoring system comprising: A battery monitoring device (30, 30A to 30D) which is individually provided corresponding to each of the plurality of batteries (21, 21A to 21D, 200) and monitors the status of the batteries; and A battery control device (40), The batteries, the battery monitoring devices and the battery control device are housed in a housing (55, 105) configured to reflect at least a portion of the radio waves, wherein: The battery control device has a host-side antenna (43) for wireless communication with the battery monitoring device. Each of the battery monitoring devices has a slave-side antenna (33) for wireless communication with the battery control device. The radio wave directivity of at least one of the radio wave directivity of each of the above-mentioned slave-side antennas and the radio wave directivity of the above-mentioned base-side antenna can be selected from a plurality of radio wave directivities having different directions of the centers of the radio wave directivities, In a channel used for wireless communication between the base station side antenna and the slave station side antenna, a radio wave directivity other than a radio wave directivity with which the communication quality of the wireless communication is the lowest among the radio wave directivities is set. [Structure 2] A battery monitoring system as described in structure 1, wherein: In the channel used for wireless communication between the base station antenna and the slave station antenna, the radio wave directivity is set to a radio wave directivity at which the reception power of the battery control device or the battery monitoring device during the wireless communication is greater than a threshold value (Wmin). [Structure 3] A battery monitoring system as described in Structure 2, wherein: In the channel used for wireless communication between the base station side antenna and the slave station side antenna, a radio wave directivity is set in which the reception power during the wireless communication is maximum among the radio wave directivities and the reception power is equal to or greater than the threshold value. [Structure 4] A battery monitoring system as described in Structure 2, wherein: Each of the battery monitoring devices has a slave-side storage unit (34), the slave-side storage unit storing directivity information, the directivity information associating each of a plurality of channels that can be used in wireless communication between the slave-side antenna and the base-side antenna with a radio wave directivity in each of the channels, in which the received power during the wireless communication is greater than the threshold value, among the radio wave directivities in each of the channels. Based on the stored directivity information, the radio wave directivity of the slave-side antenna possessed by the device is set to the radio wave directivity associated with the channel used in the wireless communication. [Structure 5] A battery monitoring system as described in Structure 4, wherein: The battery control device transmits a command for transmitting a wireless signal corresponding to each radio wave directivity from the slave-side antenna of each battery monitoring device to each battery monitoring device from the master-side antenna, upon determining that a specific condition is satisfied. When each of the battery monitoring devices receives the command via the slave-side antenna possessed by the device, the device transmits a wireless signal from the slave-side antenna possessed by the device to the battery control device. The battery control device receives the wireless signal from the battery monitoring device corresponding to each radio wave directivity through the base station side antenna, and measures the reception power of each channel of the wireless signal received by the base station side antenna. generating the directional information based on the measured reception power, and transmitting the generated directional information from the base station side antenna to the battery monitoring device, Each of the battery monitoring devices stores the directional information received by the slave-side antenna provided therein in the slave-side storage unit. [Structure 6] A battery monitoring system as described in Structure 2, wherein: The battery control device comprises a main unit side storage unit (44), wherein the main unit side storage unit (44) stores directivity information, wherein the directivity information associates each of a plurality of channels that can be used for wireless communication between the main unit side antenna and the slave unit side antenna with a radio wave directivity in each of the radio wave directivities in each of the channels, wherein the received power during the wireless communication is greater than the threshold value. Based on the stored directivity information, the radio wave directivity of the antenna on the base station side is set to the radio wave directivity associated with the channel used in the wireless communication. [Structure 7] A battery monitoring system as described in structure 6, wherein: The battery control device transmits a command to transmit a wireless signal from the slave-side antenna of each of the battery monitoring devices from the master-side antenna to each of the battery monitoring devices, when it is determined that a specific condition is satisfied. When each of the battery monitoring devices receives the command via the slave-side antenna possessed by the device, the device transmits a wireless signal from the slave-side antenna possessed by the device to the battery control device. The battery control device receives the wireless signal from the battery monitoring device through the base station side antenna when the wireless wave directivity of the base station side antenna is set to a plurality of wireless wave directivities, and measures the reception power of each channel of the wireless signal received by the base station side antenna. The directivity information is generated based on the measured reception power, and the generated directivity information is stored in the base station side storage unit. [Structure 8] A battery monitoring system as described in Structure 5 or Structure 7, wherein: The specific conditions are conditions for initially starting the battery monitoring system after each of the batteries, each of the battery monitoring devices, and the battery control device are housed in the housing portion during the manufacturing process of the battery monitoring system or when the batteries constituting the battery monitoring system are reused. [Structure 9] A battery monitoring system as described in Structure 5 or Structure 7, wherein: The battery monitoring system is installed on a mobile object (10) that a user can ride on. The specific condition is a condition that either the moving distance of the moving object or the moving time of the moving object exceeds a determination value (Lth). [Structure 10] A battery monitoring system as described in Structure 5 or Structure 7, wherein: The specific condition is a condition that an arrangement state of each of the batteries, each of the battery monitoring devices, and the battery control device in the housing section deviates from a predetermined arrangement state. [Structure 11] A battery monitoring system as described in Structure 9 or Structure 10, wherein: The battery monitoring system is installed on a mobile object (10) that a user can ride on. The battery control device transmits the command to each of the battery monitoring devices from the base station antenna when the user has not issued a start instruction for the moving object and when it is determined that the moving object is in a stopped state and the specific condition is satisfied. [Structure 12] A battery monitoring system as described in Structure 5 or Structure 7, wherein: The invention comprises an inspection device (300) connected to the battery monitoring device in a communicable manner, wherein the specific condition is a condition for requesting the inspection device for historical information on the state of the battery monitored by the battery monitoring device. [Structure 13] A battery monitoring system as described in any one of Structures 1 to 12, wherein: The antenna configured to be able to select the directivity of radio waves in the antenna on the main unit side and the antenna on the sub-unit side includes: A circuit substrate (61); An antenna component (67), the antenna component being disposed on the circuit substrate; a plurality of power supply lines (68A to 68D, 74A to 74D), the plurality of power supply lines being provided on the circuit substrate and being electrically connected to the antenna member and supplying power to the antenna member; and A ground pattern (69A to 69C, 72, 75) is provided between adjacent power supply lines in the circuit substrate. [Structure 14] A battery monitoring system as described in structure 1, wherein: In a channel used for wireless communication between the base station side antenna and the slave station side antenna, a radio wave directivity is set to a radio wave directivity in which a communication error rate during the wireless communication is equal to or less than a threshold value (Eth) among the radio wave directivities. [Structure 15] A battery monitoring system as described in structure 1, wherein: In the channel used for wireless communication between the base station antenna and the slave station antenna, a radio wave directivity is set such that the difference between the received power of the battery control device and the background noise during the wireless communication is greater than a threshold value (Wth) among the radio wave directivities. [Structure 16] A battery monitoring device, the battery monitoring device (30, 30A-30D) is suitable for a battery monitoring system, The battery monitoring system includes a plurality of batteries (21, 21A to 21D, 200) and a battery control device (40). The battery monitoring device is arranged together with each of the batteries and each of the battery monitoring devices in a receiving portion (55, 105) configured to reflect at least a portion of the radio wave. The battery monitoring device is provided individually corresponding to each of the batteries and monitors the status of the batteries. Each of the battery monitoring devices has a slave-side antenna (33) for wireless communication with the battery control device. Each of the slave-side antennas is configured so that the radio wave directivity can be selected from a plurality of radio wave directivities having different directions of the center of the radio wave directivity. In a channel used in wireless communication between a main machine side antenna (43) possessed by the battery control device and the sub-machine side antenna, the radio wave directivity of the sub-machine side antenna is set to a radio wave directivity other than the radio wave directivity with the lowest communication quality of the wireless communication among the radio wave directivities. [Structure 17] A battery control device, the battery control device (40) is suitable for a battery monitoring system including a battery monitoring device (30, 30A-30D), The battery monitoring device is individually provided corresponding to each of the plurality of batteries (21, 21A to 21D, 200), and monitors the status of the batteries. The battery control device is arranged together with each of the batteries and each of the battery monitoring devices in a storage unit (55, 105) configured to reflect at least a part of the radio wave. The battery control device has a host-side antenna (43) for wireless communication with the battery monitoring device. The base station side antenna is configured so that the radio wave directivity can be selected from a plurality of radio wave directivities having different directions of the center of the radio wave directivity. In a channel used in wireless communication between the main machine side antenna and the sub-machine side antenna (33) of the battery monitoring device, the radio wave directivity of the main machine side antenna is set to a radio wave directivity other than the radio wave directivity with the lowest communication quality of the wireless communication among the radio wave directivities.

[0207] Although the present disclosure is described based on the embodiments, it should be understood that the present disclosure is not limited to the above-mentioned embodiments and structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and methods, and other combinations and methods containing only one element, above or below them, also belong to the scope and thought range of the present disclosure.

Claims

1. A battery monitoring system, comprising: A battery monitoring device (30, 30A to 30D) which is individually provided corresponding to a plurality of batteries (21, 21A to 21D, 200) and monitors the status of the batteries; as well as A battery control device (40), The batteries, the battery monitoring devices and the battery control device are housed in a housing (55, 105) configured to at least partially reflect radio waves. The battery control device has a host side antenna (43) for wireless communication with the battery monitoring device. Each of the battery monitoring devices has a slave-side antenna (33) for wireless communication with the battery control device. The radio wave directivity of at least one of the radio wave directivity of each of the slave-side antennas and the radio wave directivity of the base-side antenna can be selected from a plurality of radio wave directivities having different directions of the centers of the radio wave directivities, In a channel used for wireless communication between the base station side antenna and the slave station side antenna, a radio wave directivity other than a radio wave directivity with which the communication quality of the wireless communication becomes the lowest among the radio wave directivities is set.

2. The battery monitoring system according to claim 1, wherein: In the channel used for wireless communication between the base station antenna and the slave station antenna, a radio wave directivity is set to a radio wave directivity at which the received power of the battery control device or the battery monitoring device during the wireless communication is greater than a threshold value (Wmin).

3. The battery monitoring system according to claim 2, characterized in that In the channel used for wireless communication between the base station side antenna and the slave station side antenna, the radio wave directivity is set to a radio wave directivity in which the reception power during the wireless communication is maximum among the radio wave directivities and the reception power is equal to or greater than the threshold value.

4. The battery monitoring system according to claim 2, characterized in that: Each of the battery monitoring devices has a slave-side storage unit (34), the slave-side storage unit storing directivity information, the directivity information associating each of a plurality of channels that can be used in wireless communication between the slave-side antenna and the base-side antenna with a radio wave directivity in each of the channels, in which the received power during the wireless communication is greater than or equal to the threshold value, Based on the stored directivity information, the radio wave directivity of the slave side antenna possessed by the device is set to the radio wave directivity associated with the channel used in the wireless communication.

5. The battery monitoring system according to claim 4, characterized in that: The battery control device sends a command from the main unit side antenna to each of the battery monitoring devices when it is determined that a specific condition is satisfied, and the command is a command to send a wireless signal corresponding to each radio wave directivity from the slave unit side antenna of each of the battery monitoring devices. When each of the battery monitoring devices receives the command through the slave-side antenna possessed by the device, the device transmits a wireless signal from the slave-side antenna possessed by the device to the battery control device. The battery control device receives the wireless signal from the battery monitoring device corresponding to each radio wave directivity through the base station side antenna, and measures the reception power of each channel of the wireless signal received by the base station side antenna. generating the directional information based on the measured reception power, and transmitting the generated directional information from the base station side antenna to the battery monitoring device, Each of the battery monitoring devices stores the directional information received by the slave-side antenna provided therein in the slave-side storage unit.

6. The battery monitoring system according to claim 2, wherein: The battery control device comprises a main unit side storage unit (44), wherein the main unit side storage unit (44) stores directivity information, wherein the directivity information associates each of a plurality of channels that can be used for wireless communication between the main unit side antenna and the slave unit side antenna with a radio wave directivity in each of the radio wave directivities in each of the channels, wherein the received power during the wireless communication is greater than or equal to the threshold value. Based on the stored directivity information, the radio wave directivity of the antenna on the base station side is set to the radio wave directivity associated with the channel used in the wireless communication.

7. The battery monitoring system according to claim 6, characterized in that: The battery control device sends a command from the main unit side antenna to each of the battery monitoring devices when it is determined that a specific condition is satisfied, and the command is a command to send a wireless signal from the slave unit side antenna of each of the battery monitoring devices. When each of the battery monitoring devices receives the command through the slave-side antenna possessed by the device, the device transmits a wireless signal from the slave-side antenna possessed by the device to the battery control device. The battery control device receives the wireless signal from the battery monitoring device through the base station side antenna when the wireless wave directivity of the base station side antenna is set to one of a plurality of wireless wave directivities, and measures the reception power of each channel of the wireless signal received by the base station side antenna. The directivity information is generated based on the measured reception power, and the generated directivity information is stored in the base station side storage unit.

8. The battery monitoring system according to claim 5 or 7, characterized in that: The specific condition is a condition that the battery monitoring system is initially started after each of the batteries, each of the battery monitoring devices, and the battery control device is accommodated in the accommodation section during the manufacturing process of the battery monitoring system or during the reuse of the batteries constituting the battery monitoring system.

9. The battery monitoring system according to claim 5 or 7, characterized in that: The battery monitoring system is installed on a mobile object (10) that a user can ride on. The specific condition is a condition that either the moving distance of the moving object or the moving time of the moving object exceeds a determination value (Lth).

10. The battery monitoring system according to claim 5 or 7, characterized in that: The specific condition is a condition that the arrangement state of each of the batteries, each of the battery monitoring devices, and the battery control device in the housing section deviates from a predetermined arrangement state.

11. The battery monitoring system according to claim 10, wherein: The battery monitoring system is installed on a mobile object (10) that a user can ride on. The battery control device transmits the command to each of the battery monitoring devices from the base station antenna when the user has not issued a start instruction for the moving object and when it is determined that the moving object is in a stopped state and when it is determined that the specific condition is satisfied.

12. The battery monitoring system according to claim 5 or 7, characterized in that: The invention comprises an inspection device (300) connected to the battery monitoring device in a communicable manner. The specific condition is a condition for requesting the inspection device to provide historical information on the state of the battery monitored by the battery monitoring device.

13. The battery monitoring system according to any one of claims 1 to 7, characterized in that: The antenna configured to be able to select the directivity of radio waves in the antenna on the main unit side and the antenna on the sub-unit side includes: A circuit substrate (61); An antenna component (67), the antenna component being arranged on the circuit substrate; a plurality of power supply lines (68A to 68D, 74A to 74D), the plurality of power supply lines being provided on the circuit substrate and being electrically connected to the antenna member and supplying power to the antenna member; as well as A ground pattern (69A to 69C, 72, 75) is provided between adjacent power supply lines in the circuit substrate.

14. The battery monitoring system according to claim 1, wherein: In a channel used for wireless communication between the base station side antenna and the slave station side antenna, a radio wave directivity is set to a radio wave directivity in which a communication error rate during the wireless communication is equal to or less than a threshold value (Eth) among the radio wave directivities.

15. The battery monitoring system according to claim 1, wherein: In the channel used for wireless communication between the base station antenna and the slave station antenna, a radio wave directivity is set such that the difference between the received power of the battery control device and the background noise during the wireless communication is greater than a threshold value (Wth).

16. A battery monitoring device, the battery monitoring device (30, 30A-30D) being suitable for a battery monitoring system, The battery monitoring system includes a plurality of batteries (21, 21A-21D, 200) and a battery control device (40). The battery monitoring device is arranged together with each of the batteries and each of the battery monitoring devices in a housing (55, 105) configured to at least partially reflect radio waves. The battery monitoring device is provided individually corresponding to each of the batteries and monitors the status of the batteries. Each of the battery monitoring devices has a slave-side antenna (33) for wireless communication with the battery control device. Each of the slave-side antennas is configured so that the radio wave directivity can be selected from a plurality of radio wave directivities having different directions of the center of the radio wave directivity. In a channel used in wireless communication between a main machine side antenna (43) possessed by the battery control device and the sub-machine side antenna, the radio wave directivity of the sub-machine side antenna is set to a radio wave directivity other than the radio wave directivity with the lowest communication quality of the wireless communication among the radio wave directivities.

17. A battery control device, the battery control device (40) being suitable for a battery monitoring system including battery monitoring devices (30, 30A to 30D), the battery monitoring devices being individually arranged corresponding to a plurality of batteries (21, 21A to 21D, 200), and monitoring the states of the batteries. The battery control device is arranged together with each of the batteries and each of the battery monitoring devices in a storage unit (55, 105) configured to at least partially reflect radio waves. The battery control device has a host side antenna (43) for wireless communication with the battery monitoring device. The base station side antenna is configured so that the radio wave directivity can be selected from a plurality of radio wave directivities having different directions of the center of the radio wave directivity. In a channel used in wireless communication between the main machine side antenna and the sub-machine side antenna (33) of the battery monitoring device, the radio wave directivity of the main machine side antenna is set to a radio wave directivity other than the radio wave directivity with the lowest communication quality of the wireless communication among the radio wave directivities.

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