Battery management system and battery management method

Abstract

To suppress the transmission failure of battery monitoring information.SOLUTION: A battery management system includes three or more monitoring devices 30 and a control device 40. The battery management system wirelessly communicates according to a communication path from the control device to the control device via each monitoring device in order. The control device transmits a request signal to request transmission of battery monitoring information to a receiving device, which is one of the monitoring devices. The control device receives the battery monitoring information of all the monitoring devices from a transmitting device, which is one of the monitoring devices and different from the receiving device. A far device, which is a monitoring device different from the receiving device and the transmitting device and located farthest from the control device among all the monitoring devices, receives the request signal via the receiving device and transmits the battery monitoring information responding to the received request signal to the control device via the transmission device.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] TECHNICAL FIELD The disclosure herein relates to a battery management system and a battery management method. [Background technology]

[0002] Patent Document 1 discloses a battery management system using wireless communication. The contents of the prior art documents are incorporated by reference as explanations of technical elements in this specification. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 8,399,115 Summary of the Invention [Problem to be solved by the invention]

[0004] In a battery management system using wireless communication, multiple monitoring devices that monitor the state of batteries are connected in series with a control device to perform wireless communication. The control device acquires battery monitoring information from one monitoring device via wireless communication and executes a predetermined process. Of the multiple monitoring devices, the monitoring device that is located farthest from the control device is more likely to fail to transmit battery monitoring information to the control device than the other monitoring devices. In the above respects, or in other respects not mentioned, further improvements are required in the battery management system and the battery management method.

[0005] One disclosed object is to provide a battery management system and a battery management method that can suppress failures in transmitting battery monitoring information. [Means for solving the problem]

[0006] The battery management system disclosed herein comprises: three or more monitoring devices (30) arranged in a housing (50) together with the batteries (20, 21, 22) and configured to acquire and monitor battery monitoring information including information indicating the state of the batteries; a control device (40) that wirelessly communicates with the two monitoring devices and executes a predetermined process based on the battery monitoring information of each monitoring device; A battery management system that wirelessly communicates over a communication path from a control device to the control device via each monitoring device, The control device includes: A transmission unit (S10) that transmits a request signal requesting transmission of battery monitoring information to a receiving device that is one of the monitoring devices; a receiving unit (S11) that receives battery monitoring information of all the monitoring devices from a transmitting device that is one of the monitoring devices and is different from the receiving device; The remote device is a monitoring device different from the receiving device and the transmitting device and is located at a greater distance from the control device than the receiving device and the transmitting device. The remote device has a transfer unit (S22) that receives a request signal via the receiving device and transmits battery monitoring information in response to the received request signal to the control device via the transmitting device.

[0007] According to the disclosed battery management system, the remote device receives a request signal via the receiving device, and transmits battery monitoring information in response to the received request signal to the control device via the transmitting device. This makes it possible to reduce failures in transmitting the battery monitoring information from the remote device to the control device.

[0008] The battery management method disclosed herein comprises: three or more monitoring devices (30) arranged in a housing (50) together with the batteries (20, 21, 22) and configured to acquire and monitor battery monitoring information including information indicating the state of the batteries; a control device (40) that wirelessly communicates with the two monitoring devices and executes a predetermined process based on the battery monitoring information of each monitoring device; A battery management method for managing a battery by wirelessly communicating along a communication path from a control device to the control device via each monitoring device, comprising: The control device includes: Transmitting a request signal to a receiving device, which is one of the monitoring devices, to request transmission of the battery monitoring information; receiving battery monitoring information of all the monitoring devices from a transmitting device which is one of the monitoring devices and is different from the receiving device; A remote device, which is a monitoring device different from the receiving device and the transmitting device and is located at a distance farther from the control device than the receiving device and the transmitting device, receives a request signal via the receiving device and transmits battery monitoring information in response to the received request signal to the control device via the transmitting device.

[0009] According to the disclosed battery management method, the remote device receives a request signal via the receiving device, and transmits battery monitoring information in response to the received request signal to the control device via the transmitting device, thereby preventing failure of transmission of the battery monitoring information from the remote device to the control device.

[0010] The various aspects disclosed in this specification adopt different technical means to achieve their respective objectives. The claims and the parenthetical symbols described in this section are merely illustrative of the corresponding relationship with the embodiments described below, and are not intended to limit the technical scope. The objectives, features, and effects disclosed in this specification will become clearer with reference to the following detailed description and the accompanying drawings. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing a vehicle equipped with a battery pack. [Diagram 2] FIG. 2 is a perspective view showing a schematic configuration of a battery pack. [Diagram 3] FIG. 2 is a plan view showing a battery pack. [Figure 4] 1 is a block diagram showing a configuration of a battery management system according to a first embodiment. [Diagram 5] FIG. 2 is a conceptual diagram showing a communication path according to the first embodiment. [Figure 6] FIG. 4 is a diagram showing a communication sequence between a monitoring device and a control device according to the first embodiment. [Figure 7] FIG. 13 is a conceptual diagram showing a communication path according to a modified example. [Figure 8] FIG. 11 is a plan view showing a battery pack according to a second embodiment. [Figure 9] FIG. 13 is a plan view showing a battery pack according to a third embodiment. [Figure 10] FIG. 13 is a plan view showing a battery pack according to a fourth embodiment. [Figure 11] 13 is a flowchart showing processing operations in a monitoring device and a control device according to a fifth embodiment. [Figure 12] FIG. 13 is an image diagram showing a communication path after change in the fifth embodiment. [Figure 13] FIG. 13 is a diagram showing an inspection system according to a sixth embodiment. [Figure 14] FIG. 13 is a block diagram showing a modified example of the battery management system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, several embodiments will be described with reference to the drawings. In addition, by assigning the same reference numerals to corresponding components in each embodiment, duplicated explanations may be omitted. When only a part of the configuration is described in each embodiment, the configuration of the other embodiment described above can be applied to the other parts of the configuration. In addition to the combination of configurations explicitly stated in the description of each embodiment, configurations of several embodiments can be partially combined together even if not explicitly stated, as long as there is no particular problem with the combination.

[0013] (First embodiment) First, the configuration of a vehicle equipped with a battery management system according to this embodiment, particularly a vehicle related to a battery pack equipped with the battery management system, will be described with reference to Fig. 1. Fig. 1 is a diagram showing a schematic configuration of a vehicle. The vehicle is an electric vehicle such as a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV). The battery management system can also be applied to moving objects other than vehicles, such as aircraft such as drones, ships, construction machinery, agricultural machinery, etc. The battery management system can also be applied to stationary batteries (storage batteries) for home or commercial use.

[0014] <Vehicle> 1, a vehicle 10 includes a battery pack (BAT) 11, a PCU 12, a MG 13, and an ECU 14. PCU is an abbreviation for Power Control Unit. MG is an abbreviation for Motor Generator. ECU is an abbreviation for Electronic Control Unit.

[0015] The battery pack 11 includes a battery assembly 20, which will be described later, and provides a chargeable and dischargeable DC voltage source. The battery pack 11 supplies power to electrical loads of the vehicle 10. For example, the battery pack 11 supplies power to the MG 13 through the PCU 12. The battery pack 11 is charged through the PCU 12. The battery pack 11 is sometimes referred to as a main battery.

[0016] The battery pack 11 is arranged in a front compartment of a vehicle 10, for example, as shown in Fig. 1. The battery pack 11 may also be arranged in a rear compartment, under a seat, under a floor, etc. For example, in the case of a hybrid vehicle, the compartment in which the engine is arranged may be called an engine compartment, an engine room, or the like.

[0017] The temperature of the battery pack 11 is adjusted by the wind generated when the vehicle 10 is running or by cooling wind supplied from a fan mounted on the vehicle 10. The temperature of the battery pack 11 may be adjusted by a cooling liquid circulating inside the vehicle 10. By the above-mentioned temperature adjustment, excessive temperature changes in the battery pack 11 are suppressed. Note that the battery pack 11 may simply be connected to a member having a large heat capacity, such as the body of the vehicle 10, in a manner capable of conducting heat.

[0018] The PCU 12 performs bidirectional power conversion between the battery pack 11 and the MG 13 in accordance with a control signal from the ECU 14. The PCU 12 is sometimes referred to as a power converter. The PCU 12 may include and a converter. The converter is disposed in a current path between the PCU 12 and the battery pack 11. The converter has a function of stepping up and stepping down a DC voltage. converts the DC voltage stepped up by the converter into an AC voltage, for example, a three-phase AC voltage, and outputs it to the MG 13. converts the power generated by the MG 13 into a DC voltage and outputs it to the converter.

[0019] The MG 13 is an AC rotating electric machine, for example, a three-phase AC synchronous motor with a permanent magnet embedded in the rotor. The MG 13 functions as a driving source for the vehicle 10, that is, an electric motor. The MG 13 is driven by the PCU 12 to generate a rotational driving force. The driving force generated by the MG 13 is transmitted to the driving wheels. The MG 13 functions as a generator when the vehicle 10 is braked, and performs regenerative power generation. The generated power of the MG 13 is supplied to the battery pack 11 via the PCU 12 and stored in the battery pack 20 in the battery pack 11.

[0020] The ECU 14 includes a computer equipped with a processor, a memory, an input / output interface, and a bus connecting these. The processor is hardware for arithmetic processing. The processor includes, for example, a CPU as a core. CPU is an abbreviation for Central Processing Unit. The memory is a non-transient, tangible storage medium that non-temporarily stores computer-readable programs, data, and the like. The memory stores various programs executed by the processor.

[0021] The ECU 14 acquires information about the assembled battery 20 from the battery pack 11, for example, and controls the PCU 12 to control the driving of the MG 13 and the charging and discharging of the battery pack 11. The ECU 14 may acquire information about the voltage, temperature, current, SOC, SOH, etc. of the assembled battery 20 from the battery pack 11. The ECU 14 may acquire battery information about the assembled battery 20, such as the voltage, temperature, and current, to calculate the SOC and SOH. SOC is an abbreviation for State Of Charge. SOH is an abbreviation for State Of Health.

[0022] The processor of the ECU 14 executes a plurality of instructions included in a PCU control program stored in a memory, for example. In this way, the ECU 14 configures a plurality of functional units for controlling the PCU 12. In this way, the program stored in the memory causes the processor to execute a plurality of instructions, thereby configuring a plurality of functional units in the ECU 14. The ECU 14 is sometimes referred to as an EVECU.

[0023] <Battery pack> Next, an example of the configuration of the battery pack 11 will be described with reference to Fig. 2 and Fig. 3. Fig. 2 is a perspective view showing a schematic view of the inside of the battery pack 11. In Fig. 2, the housing is indicated by a two-dot chain line. Fig. 3 is a plan view showing the upper surface of each battery stack.

[0024] As shown in FIG. 2, the battery pack 11 includes a battery pack 20, three or more monitoring devices 30, a control device 40, and a housing 50. In the following, of the faces of the housing 50, which is a substantially rectangular parallelepiped, the longitudinal direction of the mounting face on the vehicle 10 is indicated as the X direction, and the lateral direction is indicated as the Y direction. In FIG. 2, the lower face is the mounting face. The up-down direction perpendicular to the mounting face is indicated as the Z direction. The X direction, the Y direction, and the Z direction are in a positional relationship perpendicular to each other. In this embodiment, the left-right direction of the vehicle 10 corresponds to the X direction, the front-rear direction corresponds to the Y direction, and the up-down direction corresponds to the Z direction. The arrangements in FIG. 2 and FIG. 3 are merely examples, and the battery pack 11 may be arranged in any manner with respect to the vehicle 10.

[0025] The battery pack 20 has a plurality of battery stacks 21 arranged side by side in the X direction. The battery stacks 21 may be referred to as a battery block, a battery module, or the like. The battery pack 20 is configured by connecting a plurality of battery stacks 21 in series and / or parallel. In this embodiment, the plurality of battery stacks 21 are connected in series.

[0026] Each battery stack 21 has a plurality of battery cells 22. The plurality of battery cells 22 are housed in a case (not shown). This fixes the relative positions of the plurality of battery cells 22. The case is made of metal or resin. If the case is made of metal, an electrically insulating member may be interposed partially or entirely between the wall surface of the case and the battery cells 22.

[0027] The form of the fixing member is not particularly limited as long as it can fix the relative positions of the multiple battery cells 22. For example, a configuration in which the multiple battery cells 22 are restrained by a strip-shaped band may be adopted. In this case, a separator may be interposed between the multiple battery cells 22 to maintain a distance between them.

[0028] The battery stack 21 has a plurality of battery cells 22 connected in series. The battery stack 21 of this embodiment is configured by connecting a plurality of battery cells 22 arranged side by side in the Y direction in series. The assembled battery 20 provides the above-mentioned DC voltage source. The assembled battery 20, the battery stack 21, and the battery cells 22 correspond to a battery.

[0029] The battery cell 22 is a secondary battery that generates an electromotive force by a chemical reaction. As the secondary battery, a lithium ion secondary battery, a nickel-metal hydride secondary battery, an organic radical battery, or the like can be used. A lithium ion secondary battery is a secondary battery that uses lithium as a charge carrier. Secondary batteries that can be used for the battery cell 22 include not only secondary batteries with a liquid electrolyte, but also so-called all-solid-state batteries that use a solid electrolyte.

[0030] The battery cell 22 has a power generating element and a battery case that houses the power generating element. As shown in Fig. 3, the battery case of each battery cell 22 is formed in a flat shape. The battery case has a total of four side surfaces, including two end surfaces aligned in the Z direction, two aligned in the X direction, and two aligned in the Y direction. The battery case of this embodiment is made of metal.

[0031] The battery cells 22 are stacked such that the side surfaces of the battery cases are in contact with each other in the Y direction. The battery cells 22 have a positive terminal 25 and a negative terminal 26 at both ends in the X direction that protrude in the Z direction, more specifically, in the Z+ direction indicating upward. The Z direction positions of the protruding end faces of the positive terminal 25 and the negative terminal 26 are the same for each battery cell 22. The battery cells 22 are stacked such that the positive terminals 25 and the negative terminals 26 are alternately arranged in the Y direction.

[0032] Straight busbar units 23 are arranged on both ends in the X direction on the top surface of each battery stack 21. The busbar units 23 are arranged on both ends in the X direction of the end faces from which the positive electrode terminals 25 and the negative electrode terminals 26 of the multiple battery cases protrude. That is, a pair of busbar units 23 are arranged in each battery stack 21.

[0033] Each busbar unit 23 has a plurality of busbars 24 that electrically connect positive electrode terminals 25 and negative electrode terminals 26 that are alternately arranged in the Y direction, and a busbar cover 27 that covers the plurality of busbars 24. The busbars 24 are plate materials made of a metal with good conductivity such as copper or aluminum. The busbars 24 electrically connect the positive electrode terminals 25 and negative electrode terminals 26 of the battery cells 22 that are adjacent to each other in the Y direction. As a result, in each battery stack 21, the plurality of battery cells 22 are connected in series.

[0034] With this connection structure, one of the two battery cells 22 located at the ends of the multiple battery cells 22 aligned in the Y direction in each battery stack 21 has the highest potential, and the other has the lowest potential. A predetermined wiring is connected to at least one of the positive electrode terminal 25 of the battery cell 22 with the highest potential and the negative electrode terminal 26 of the battery cell 22 with the lowest potential.

[0035] 2, the multiple battery stacks 21 are aligned in the X direction. In one of two battery stacks 21 adjacent to each other in the X direction, the positive electrode terminal 25 of the battery cell 22 with the highest potential is connected to the negative electrode terminal 26 of the battery cell 22 with the lowest potential in the other battery stack 21 via a predetermined wiring. In this way, the multiple battery stacks 21 are connected in series.

[0036] With this connection structure, one of the two battery stacks 21 located at the ends of the multiple battery stacks 21 lined up in the X direction becomes the highest potential side, and the other becomes the lowest potential side. In the battery stack 21 on the highest potential side, an output terminal is connected to the positive electrode terminal 25 of the battery cell 22 with the highest potential among the multiple battery cells 22. In the battery stack 21 on the lowest potential side, an output terminal is connected to the negative electrode terminal 26 of the battery cell 22 with the lowest potential among the multiple battery cells 22. These two output terminals are connected to electrical devices mounted on the vehicle 10, such as the PCU 12.

[0037] Two adjacent battery stacks 21 in the X direction may not be electrically connected via a predetermined wiring. Any two of the multiple battery stacks 21 arranged in the X direction may be electrically connected via a predetermined wiring. The positions in the Y direction of the positive electrode terminal 25 and the negative electrode terminal 26 electrically connected via the predetermined wiring may be equal or different. That is, the positive electrode terminal 25 and the negative electrode terminal 26 may at least partially face each other in the X direction, or may not face each other at all. At least a part of the positive electrode terminal 25 and the negative electrode terminal 26 may be located in the projection area of ​​the other in the X direction, or may not be located at all.

[0038] The busbar cover 27 is made of an electrically insulating material such as resin. The busbar cover 27 is provided linearly from one end of the battery stack 21 to the other end along the Y direction so as to cover the multiple busbars 24. The busbar cover 27 may have a partition wall. The partition wall improves the insulation between two busbars 24 adjacent to each other in the Y direction.

[0039] The monitoring device 30 is provided for each of the battery stacks 21. As shown in FIG. 2, the monitoring device 30 is disposed between a pair of busbar units 23 in each battery stack 21. The monitoring device 30 faces the protruding end faces of the positive electrode terminal 25 and the negative electrode terminal 26 of the battery case in the Z direction. The monitoring device 30 and the end faces may be spaced apart in the Z direction, or may face each other and be in contact with each other in the Z direction. An intermediary such as an insulating sheet may be provided between the monitoring device 30 and the end faces. The monitoring device 30 is provided for each of the battery stacks 21.

[0040] The monitoring device 30 is fixed to the busbar unit 23 with screws or the like. The monitoring device 30 is configured to be able to wirelessly communicate with the control device 40, as described below. An antenna 37, which is provided in the monitoring device 30 and will be described later, is disposed so as not to overlap with the busbar unit 23 in the Z direction, that is, so as to protrude further than the busbar unit 23 in the Z direction.

[0041] In order to avoid interference with wireless communication, for example, a non-magnetic material may be used as the material of the connecting members such as the screws that connect the monitoring device 30 and the busbar unit 23. In addition to the screws, non-magnetic materials may be used as the constituent materials of the parts provided in the battery stack 21 that do not need to be magnetic.

[0042] In this embodiment, the multiple monitoring devices 30 are lined up in the X direction. The multiple monitoring devices 30 are positioned at the same positions in the Y direction. Due to the above-described configuration, the distance between the multiple monitoring devices 30 is prevented from increasing.

[0043] The control device 40 is attached to the outer surface of the battery stack 21 arranged at one end in the X direction. The control device 40 is configured to be able to wirelessly communicate with each monitoring device 30. An antenna 42 (described later) provided in the control device 40 is arranged at approximately the same height in the Z direction as an antenna 37 of the monitoring device 30. In other words, the antenna 42 of the control device 40 is arranged to protrude further than the busbar unit 23 in the Z direction.

[0044] In the battery pack 11, the monitoring device 30 and the control device 40 provide a battery management system 60, which will be described later.

[0045] The housing 50 houses other elements constituting the battery pack 11, that is, the assembled battery 20, the monitoring device 30, and the control device 40. Wireless communication between the monitoring device 30 and the control device 40 is performed in the housing space of the housing 50. In order to prevent the battery pack 11 from becoming a source of electromagnetic noise, it is necessary to suppress the radio waves of the wireless communication from leaking out of the space (communication space) in which the wireless communication between the monitoring device 30 and the control device 40 is performed. Conversely, in order to suppress the wireless communication from being obstructed, it is necessary to suppress the electromagnetic noise from entering the communication space of the housing 50. Note that the control device 40 does not have to be housed in the housing 50. Therefore, the communication space is not limited to the housing space of the housing 50. In other embodiments, the control device 40 may or may not be housed in the housing 50.

[0046] For this reason, the housing 50 has, for example, the ability to reflect electromagnetic waves. The housing 50 is provided with the materials shown below as examples in order to reflect electromagnetic waves. For example, the housing 50 is provided with a magnetic material such as a metal. The housing 50 is provided with a resin material and a magnetic material covering the surface of the resin material. The housing 50 is provided with a resin material and a magnetic material embedded therein. The housing 50 is provided with carbon fiber. The housing 50 may have the ability to absorb electromagnetic waves instead of the ability to reflect electromagnetic waves.

[0047] The housing 50 may have a hole that communicates with the storage space inside and the space outside (external space). The hole is defined by a connecting surface between the inner surface and the outer surface of the housing 50. The hole is used for ventilation, taking out power lines, taking out signal lines, etc. In the case of a configuration having a hole, a cover may be provided for the hole. The cover prevents communication between the storage space and the external space. The cover may block the entire hole or may block only a part of the hole.

[0048] The cover is provided, for example, on any one of the inner surface, the outer surface, and the connecting surface of the housing 50. The cover may be disposed opposite the hole in a manner that covers the hole without being provided on any of the inner surface, the outer surface, and the connecting surface. When the cover and the hole are spaced apart, the distance between them is shorter than the length of the hole. The length of the hole is either the distance between the inner surface and the outer surface, or the distance in a direction perpendicular to this distance.

[0049] The covering portion is, for example, a connector, an electromagnetic shielding member, a sealing material, etc. The covering portion comprises the following materials, examples of which are shown below: The covering portion comprises a magnetic material, such as a metal. The covering portion comprises a resin material and a magnetic material covering the surface of the resin material. The covering portion comprises a resin material and a magnetic material embedded therein. The covering portion comprises carbon fiber. The covering portion contains a resin material.

[0050] The hole in the housing 50 may be covered by at least one of the elements contained in the storage space of the housing 50. The distance between the contained object and the hole is shorter than the length of the hole. In addition, the power line and the signal line may be arranged across the storage space and the external space while being held by an electrically insulating member that forms part of the wall of the housing 50.

[0051] <Battery management system> Next, a schematic configuration of the battery management system will be described with reference to Fig. 4. Fig. 4 is a block diagram showing the configuration of the battery management system.

[0052] As shown in Fig. 4, the battery management system 60 includes a plurality of monitoring devices (SBM) 30 and a control device (ECU) 40. Hereinafter, the monitoring devices may be referred to as SBMs. The control device 40 may be referred to as a battery ECU, BMU, etc. BMU is an abbreviation for Battery Management Unit. The battery management system 60 is a system that manages batteries using wireless communication. This wireless communication uses a frequency band used in short-range communication, such as the 2.4 GHz band or the 5 GHz band.

[0053] The battery management system 60 employs one-to-one communication or network communication depending on the number of nodes for wireless communication by the monitoring device 30 and / or the control device 40. The number of nodes may change depending on the hibernation state of the monitoring device 30 and / or the control device 40. When the number of nodes is two, the battery management system 60 employs one-to-one communication. When the number of nodes is three or more, the battery management system 60 employs network communication. One form of network communication is star communication, in which one node is the master and the remaining nodes are slaves, and wireless communication is performed between the master and all of the slaves. Another form of network communication is chain communication, in which multiple nodes are connected in series and wireless communication is performed.

[0054] The battery management system 60 further includes a sensor 70. The sensor 70 includes a physical quantity detection sensor and a discrimination sensor that detect the physical quantity of each battery cell 22. The physical quantity detection sensor includes, for example, a voltage sensor, a temperature sensor, and a current sensor.

[0055] The voltage sensor includes detection wiring connected to the bus bar 24. The voltage sensor detects the voltage (cell voltage) of each of the multiple battery cells 22. The discrimination sensor discriminates whether or not a correct battery is attached.

[0056] The temperature sensor is selectively provided in some of the multiple battery cells 22 included in the battery stack 21. The temperature sensor detects the temperature (cell temperature) of the selected battery cell 22 as the temperature of the battery stack 21. The temperature sensor is provided in a battery cell 22 that is expected to have the highest temperature, a battery cell 22 that is expected to have the lowest temperature, a battery cell 22 that is expected to have an intermediate temperature, or the like, among the multiple battery cells 22 included in one battery stack 21. The number of temperature sensors for one battery stack 21 is not particularly limited.

[0057] A current sensor is provided in each of the multiple battery stacks 21. The current sensor detects a current (cell current) flowing commonly through each of the multiple battery cells 22 connected in series and the multiple battery stacks 21 connected in series. In this embodiment, since all the battery stacks 21 are connected in series, one current sensor is provided, but the number of current sensors is not limited to this example.

[0058] <Monitoring device> First, the monitoring device 30 will be described. The configuration of each monitoring device 30 is the same. The monitoring device 30 includes a power supply circuit (PSC) 31, a multiplexer (MUX) 32, a monitoring IC (MIC) 33, a microcomputer (MC) 34, a wireless IC (WIC) 35, a front-end circuit (FE) 36, and an antenna (ANT) 37. Communication between the elements in the monitoring device 30 is performed by wire.

[0059] The power supply circuit 31 generates operating power for other circuit elements included in the monitoring device 30, using the voltage supplied from the battery stack 21. In this embodiment, the power supply circuit 31 includes power supply circuits 311, 312, and 313. The power supply circuit 311 generates a predetermined voltage using the voltage supplied from the battery stack 21, and supplies the predetermined voltage to the monitoring IC 33. The power supply circuit 312 generates a predetermined voltage using the voltage generated by the power supply circuit 311, and supplies the predetermined voltage to the microcomputer 34. The power supply circuit 313 generates a predetermined voltage using the voltage generated by the power supply circuit 311, and supplies the predetermined voltage to the wireless IC 35.

[0060] The multiplexer 32 is a selection circuit that selects one of at least some of the detection signals of the multiple sensors 70 included in the battery pack 11 and outputs the selected signal. The multiplexer 32 selects (switches) the input according to a selection signal from the monitoring IC 33 and outputs it as one signal.

[0061] The monitoring IC 33 senses (acquires) battery information such as cell voltage, cell temperature, and cell discrimination, and transmits the information to the microcomputer 34. For example, the monitoring IC 33 acquires the cell voltage directly from a voltage sensor, and acquires information such as the cell temperature through a multiplexer. The monitoring IC 33 acquires the cell voltage by associating it with which battery cell 22 the value belongs to. The cell current detected by the current sensor may be input to the monitoring IC 33, or may be input to the control device 40 via a wired connection.

[0062] The monitoring IC 33 may be referred to as a cell supervising circuit (CSC). CSC is an abbreviation of Cell Supervising Circuit. The monitoring IC 33 executes a fault diagnosis of the circuit portion of the monitoring device 30 including itself. That is, the monitoring IC 33 transmits battery monitoring information including battery information and fault diagnosis information to the microcomputer 34. The monitoring device 30 may store (preserve) the acquired battery monitoring information in a memory such as the microcomputer 34. When the monitoring IC 33 receives data requesting acquisition of the battery monitoring information transmitted from the microcomputer 34, it senses the battery information through the multiplexer 32 and transmits the battery monitoring information including the battery information to the microcomputer 34. In addition to the above examples, the battery monitoring information may include information such as the exhaust gas temperature, impedance, the state of cell voltage equalization, stack voltage, the state of synchronization with the control device 40, and the presence or absence of an abnormality in the detection wiring.

[0063] The microcomputer 34 is a microcomputer equipped with a processor (CPU), memory (ROM and RAM), an input / output interface, and a bus connecting these. The CPU executes various programs stored in the ROM while utilizing the temporary storage function of the RAM, thereby constructing multiple functional units. ROM is an abbreviation for Read Only Memory. RAM is an abbreviation for Random Access Memory.

[0064] The microcomputer 34 controls a schedule for sensing and self-diagnosis by the monitoring IC 33. The microcomputer 34 receives battery monitoring information transmitted from the monitoring IC 33 and transmits it to the wireless IC 35. The microcomputer 34 transmits data requesting acquisition of the battery monitoring information to the monitoring IC 33. For example, when the microcomputer 34 receives data requesting acquisition of the battery monitoring information transmitted from the wireless IC 35, the microcomputer 34 may transmit data requesting acquisition of the battery monitoring information to the monitoring IC 33. The microcomputer 34 may autonomously request the monitoring IC 33 to acquire the battery monitoring information. For example, the microcomputer 34 may periodically request the monitoring IC 33 to acquire the battery monitoring information.

[0065] The wireless IC 35 includes an RF circuit and a microcomputer (not shown) for wirelessly transmitting and receiving data. The microcomputer includes a memory. The wireless IC 35 has a transmitting function of modulating the transmission data and oscillating at the frequency of an RF signal. The wireless IC 35 has a receiving function of demodulating the reception data. RF is an abbreviation for radio frequency. The transmission data and reception data can be collectively referred to as communication data.

[0066] The wireless IC 35 modulates the data including the battery monitoring information transmitted from the microcomputer 34, and transmits it to other nodes such as the control device 40 via the front-end circuit 36 ​​and the antenna 37. The wireless IC 35 adds data necessary for wireless communication such as communication control information to the transmission data including the battery monitoring information and transmits it. The data necessary for wireless communication includes, for example, an identifier (ID) and an error detection code. The wireless IC 35 controls the data size, communication format, schedule, error detection, etc. of wireless communication with other nodes.

[0067] The wireless IC 35 receives data transmitted from other nodes via the antenna 37 and the front-end circuit 36 ​​and demodulates the data. When the wireless IC 35 receives data including a transmission request for battery monitoring information, for example, the wireless IC 35 transmits the data including the battery monitoring information to other nodes in response to the request. The monitoring device 30 may transmit battery traceability information and / or manufacturing history information to other nodes in addition to the above-mentioned battery monitoring information. The battery traceability information is, for example, the number of charge / discharge cycles, the number of failures, and the total charge / discharge time. The manufacturing history information is, for example, the manufacturing date, location, manufacturer, serial number, and manufacturing number. The manufacturing history information is stored in a memory provided in the monitoring device 30.

[0068] The front-end circuit 36 ​​includes a matching circuit for impedance matching between the wireless IC 35 and the antenna 37, and a filter circuit for removing unnecessary frequency components.

[0069] The antenna 37 converts the electric signal into a radio wave and radiates it into space. The antenna 37 receives the radio wave propagating through space and converts it into an electric signal.

[0070] <Control device> Next, the control device 40 will be described with reference to Fig. 4. The control device 40 includes a power supply circuit (PSC) 41, an antenna (ANT) 42, a front-end circuit (FE) 43, a wireless IC (WIC) 44, a main microcomputer (MMC) 45, and a sub-microcomputer (SMC) 46. Communication between the elements in the control device 40 is performed via wires.

[0071] The power supply circuit 41 generates operating power for other circuit elements included in the control device 40 using a voltage supplied from the battery (BAT) 15. The battery 15 is a DC voltage source mounted on the vehicle 10 and separate from the battery pack 11. The battery 15 is sometimes referred to as an auxiliary battery because it supplies power to the auxiliary devices of the vehicle 10. In this embodiment, the power supply circuit 41 includes power supply circuits 411 and 412. The power supply circuit 411 generates a predetermined voltage using the voltage supplied from the battery 15 and supplies it to the main microcomputer 45 and the sub-microcomputer 46. To simplify the diagram, an electrical connection between the power supply circuit 411 and the sub-microcomputer 46 is omitted. The power supply circuit 412 generates a predetermined voltage using the voltage generated by the power supply circuit 411 and supplies it to the wireless IC 44.

[0072] The antenna 42 converts the electric signal into a radio wave and radiates it into space. The antenna 42 receives the radio wave propagating through space and converts it into an electric signal.

[0073] The front-end circuit 43 has a matching circuit for impedance matching between the wireless IC 44 and the antenna 42, and a filter circuit for removing unnecessary frequency components.

[0074] The wireless IC 44 includes an RF circuit and a microcomputer (not shown) for wirelessly transmitting and receiving data. The wireless IC 44 has a transmitting function and a receiving function, similar to the wireless IC 35. The wireless IC 44 receives data transmitted from the monitoring device 30 via the antenna 42 and the front-end circuit 43, and demodulates the data. Then, the wireless IC 44 transmits data including the battery monitoring information to the main microcomputer 45. The wireless IC 44 receives data transmitted from the main microcomputer 45, modulates the data, and transmits the data to the monitoring device 30 via the front-end circuit 43 and the antenna 42. The wireless IC 44 adds data necessary for wireless communication, such as communication control information, to the transmission data and transmits the data. The data necessary for wireless communication includes, for example, an identifier (ID) and an error detection code. The wireless IC 44 controls the data size, communication format, schedule, error detection, and the like of wireless communication with other nodes.

[0075] The main microcomputer 45 is a microcomputer equipped with a CPU, a ROM, a RAM, an input / output interface, and a bus connecting these. The ROM stores various programs executed by the CPU. The main microcomputer 45 generates a command requesting the monitoring device 30 to perform a specific process, and transmits transmission data including the command to the wireless IC 44.

[0076] The main microcomputer 45 generates, for example, a command requesting the transmission of battery monitoring information. The main microcomputer 45 may generate a command requesting the transmission of battery monitoring information and a command requesting the acquisition of the battery monitoring information. The main microcomputer 45 may also generate a command requesting the transmission of battery monitoring information and a command requesting the acquisition of the battery monitoring information. These commands may be included in the request data transmitted from the control device 40 to the monitoring device 30. The command requesting the transmission of battery monitoring information corresponds to a request signal. The request signal may be a command requesting the transmission of battery monitoring information and a command requesting the acquisition of the battery monitoring information. The request described in this specification may be referred to as an instruction.

[0077] The main microcomputer 45 receives data including the battery monitoring information transmitted from the wireless IC 44, and executes a predetermined process based on the battery monitoring information. In this embodiment, the main microcomputer 45 acquires a cell current from a current sensor, and executes a predetermined process based on the battery monitoring information and the acquired cell current. For example, the main microcomputer 45 executes a process of transmitting the acquired battery monitoring information to the ECU 14. The main microcomputer 45 may calculate at least one of the internal resistance, open circuit voltage (OCV), SOC, and SOH of the battery cell 22 based on the battery monitoring information, and transmit information including the calculated data to the ECU 14. OCV is an abbreviation for Open Circuit Voltage.

[0078] The main microcomputer 45 performs an estimation process of the internal resistance and open circuit voltage of the battery cell 22, for example, based on the cell voltage and cell current. The open circuit voltage is the cell voltage according to the SOC of the battery cell 22. The open circuit voltage is the cell voltage when no current is flowing. There is a difference between the open circuit voltage and the cell voltage acquired by the monitoring device 30, which is a voltage drop according to the internal resistance and the cell current. The internal resistance changes according to the cell temperature. The lower the cell temperature, the larger the value of the internal resistance. The main microcomputer 45 performs an estimation process of the internal resistance and open circuit voltage of the battery cell 22, for example, taking into account the cell temperature.

[0079] The main microcomputer 45 may instruct the execution of an equalization process for equalizing the voltages of the battery cells 22 based on the battery monitoring information. The main microcomputer 45 may acquire an IG signal of the vehicle 10 and execute the above-mentioned process according to the driving state of the vehicle 10. The main microcomputer 45 may execute a process for detecting an abnormality in the battery cells 22 or circuits based on the battery monitoring information, and may transmit abnormality detection information to the ECU 14.

[0080] The sub-microcomputer 46 is a microcomputer equipped with a CPU, a ROM, a RAM, an input / output interface, and a bus connecting these. The ROM stores various programs executed by the CPU. The sub-microcomputer 46 executes monitoring processing within the control device 40. For example, the sub-microcomputer 46 may monitor data between the wireless IC 44 and the main microcomputer 45. The sub-microcomputer 46 may monitor the status of the main microcomputer 45. The sub-microcomputer 46 may monitor the status of the wireless IC 44.

[0081] <Location and communication paths> Here, the arrangement of the monitoring device 30 and the control device 40 and the communication paths will be described with reference to FIG. 5. FIG. 5 shows the distance relationship between each monitoring device 30 and the control device 40, and the communication paths. Note that in FIG. 5, in order to simplify the description, four monitoring devices 30 are used for the description. In FIG. 5, in order to distinguish between the four monitoring devices 30, 1SBM, 2SBM, 3SBM, and 4SBM are written. The 1SBM is referred to as the first monitoring device 30. The 2SBM is referred to as the second monitoring device 30. The 3SBM is referred to as the third monitoring device 30. The 4SBM is referred to as the fourth monitoring device 30.

[0082] First, the arrangement will be described with reference to Fig. 5. In this embodiment, a housing 50 having four side walls 51 to 53 is used. The side walls 51 and 52 are provided in a positional relationship in which they face each other. The side walls 53 and 54 are provided in a positional relationship in which they face each other. The side walls 51 and 52 are side walls in the longitudinal direction. The side walls 53 and 54 are side walls in the lateral direction.

[0083] The monitoring devices 30 are arranged along the side wall 51. The control device 40 is arranged at a position offset from the row of the monitoring devices 30. However, the positional relationship of the control device 40 with respect to the monitoring devices 30 is not limited to this.

[0084] 5 indicate distances x1 to x4 between each monitoring device 30 and the control device 40. Each of the distances x1 to x4 is the shortest distance between each monitoring device 30 and the control device 40. Furthermore, each of the distances x1 to x4 may be the shortest distance between the antenna 37 of each monitoring device 30 and the antenna 42 of the control device 40.

[0085] 5, the distance x4 between the control device 40 and the fourth monitoring device 30 is longer than the other distances x1 to x3. Therefore, among all the monitoring devices 30, the fourth monitoring device 30 is disposed at the farthest position from the control device 40.

[0086] For this reason, in this embodiment, the fourth monitoring device 30 corresponds to the distant device. However, the present disclosure is not limited to this. The distant device changes depending on the positional relationship between each monitoring device 30 and the control device 40. In addition, the distant device can be adopted as long as it is a monitoring device arranged at a position farther away from the control device 40 than the receiving device and transmitting device described later. Note that the fourth monitoring device 30 is a monitoring device 30 different from the receiving device and transmitting device described later. In addition, here, the distant device is determined by the straight-line distance between each monitoring device 30 and the control device 40. However, it may be determined by the distance of a detour route instead of the straight-line distance. Note that this point is also the same in the inspection system described later. In other words, the positional relationship between the inspection distant device and the inspection transmitting device and the inspection receiving device described later is the same as the positional relationship between the distant device and the receiving device and transmitting device.

[0087] Next, the communication paths will be described with reference to Fig. 5. The dashed lines in Fig. 5 indicate communication paths for wireless communication. The battery management system 60 of this embodiment performs chain communication when the number of nodes is four or more. Each node performs wireless communication with the node to which it is connected by each dashed line.

[0088] The communication path is a path along which wireless communication is performed in chain communication. The communication path can also be said to be a path along which wireless communication is performed from the control device 40 to the control device 40 via each monitoring device 30 in order. The communication path can also be said to indicate the order of each node through which wireless communication is performed in chain communication. The communication path can also be said to indicate a combination of each node through which wireless communication is performed in order in chain communication. The order of each monitoring device 30 is not limited to a predetermined order and can also be changed. This is also true for the inspection system described later.

[0089] The dashed arrow indicates the direction of data transmission by wireless communication. In other words, the dashed arrow direction indicates the destination of wireless communication. The dashed line can also be said to be the direction of packet transmission.

[0090] The control device 40 and each monitoring device 30 communicate wirelessly with two nodes, a destination and a source of wireless communication. For example, the control device 40 communicates wirelessly with two nodes, a first monitoring device 30 and a second monitoring device 30. The control device 40 and each monitoring device 30 communicate wirelessly along a predetermined communication path. In the example of FIG. 5, a communication path is adopted in which wireless communication is performed in the order of the control device 40, the first monitoring device 30, the third monitoring device 30, the fourth monitoring device 30, the second monitoring device 30, and the control device 40. It can be said that the battery management system 60 performs wireless communication in a one-way manner from the control device 40 to the control device 40 via each monitoring device 30 in order.

[0091] In other words, it can be said that the control device 40 and each monitoring device 30 have a predetermined transmission partner (node) to transmit data, etc., via wireless communication. It can also be said that the control device 40 and each monitoring device 30 have a predetermined communication partner.

[0092] More specifically, the ID of the transmission destination is preset for the control device 40 and each monitoring device 30. The ID of the first monitoring device 30 is set for the control device 40. The ID of the third monitoring device 30 is set for the first monitoring device 30. The ID of the fourth monitoring device 30 is set for the third monitoring device 30. The ID of the second monitoring device 30 is set for the fourth monitoring device 30. Therefore, when the control device 40 and each monitoring device 30 transmit advertisement packets or battery monitoring information, which will be described later, they transmit advertisement packets or battery monitoring information that include the ID of the transmission destination that has been preset.

[0093] In the battery management system 60 in which the communication path is set in this manner, the first monitoring device 30, which is one of the multiple monitoring devices 30, receives request data from the control device 40. In addition, in the battery management system 60, the second monitoring device 30, which is one of the multiple monitoring devices 30, transmits battery monitoring information to the control device 40. Therefore, in this embodiment, the first monitoring device 30 corresponds to a receiving device, and the second monitoring device 30 corresponds to a transmitting device. However, the present disclosure is not limited to this. The receiving device and the transmitting device are determined by the set communication path. Note that the receiving device and the transmitting device are different monitoring devices 30. Also, the roles of the receiving device, the transmitting device, and the remote device can be assigned to all the monitoring devices 30 arbitrarily. This point is also the same for the inspection system described later.

[0094] <Periodic communication processing> Next, the periodic communication process will be described with reference to Fig. 6. Fig. 6 is a diagram showing a communication sequence of wireless communication between each node. The communication sequence may be called a communication flow. Fig. 6 also shows an example of the periodic communication process.

[0095] In Fig. 6, it is assumed that each node has completed the connection process with a predetermined communication partner. The connection process includes a connection establishment process and a pairing process. One of the two communication partner nodes performs a scan operation, and the other performs an advertising operation.

[0096] Each node performs an advertising operation to inform its communication partner of its existence. In other words, a node that performs an advertising operation transmits an advertisement packet that includes the ID of the communication partner. The advertisement packet also includes its own ID.

[0097] A node performing a scan operation detects advertisement packets, i.e., communication partners, through the scan operation, and then transmits a connection request to the detected communication partners.

[0098] When an advertising node receives a connection request, a connection is established between the two nodes. Note that the advertising node stops sending advertisement packets once the connection is established. The advertising node periodically sends advertisement packets until the connection is established.

[0099] When the connection establishment process is completed, a pairing process is then executed. The pairing process is a process for performing encrypted data communication. The pairing process includes a process for exchanging unique information. In this exchange process, unique information held by each device is exchanged and stored. After the exchange process is executed, encryption using the exchanged unique information becomes possible. The unique information is, for example, key information, information for generating a key, etc.

[0100] When the connection process is completed, each node executes a periodic communication process. In step S10, the control device 40 transmits request data to the first monitoring device 30, which is the transmission partner (transmitter). As an example, the control device 40 transmits request data including a command requesting transmission of battery monitoring information. In this manner, the control device 40 transmits the request data to the first monitoring device 30, which is one of the multiple monitoring devices 30. The control device 40 receives the request data via the wireless IC 35, the front-end circuit 36, and the antenna 37.

[0101] When the first monitoring device 30 receives the request data from the control device 40, in step S20, it transmits the request data and battery monitoring information. At this time, the first monitoring device 30 transmits the request data and battery monitoring information to the third monitoring device 30, which is the transmission destination. The first monitoring device 30 transmits the battery monitoring information it has acquired. The battery monitoring information acquired by the first monitoring device 30 itself is battery monitoring information acquired by a monitoring IC 33 provided in the first monitoring device 30. In other words, it is not battery information received by wireless communication. The same applies to the battery monitoring information acquired by each monitoring device 30 described below.

[0102] When the third monitoring device 30 receives the request data from the first monitoring device 30, in step S21, it transmits the request data and battery monitoring information. At this time, the second monitoring device 30 transmits the request data and battery monitoring information to the fourth monitoring device 30, which is the transmission destination. Furthermore, the third monitoring device 30 transmits the battery monitoring information received from the first monitoring device 30 in addition to the battery monitoring information it has acquired. In other words, the third monitoring device 30 transmits the battery monitoring information it has acquired and the electronic monitoring information acquired by the first monitoring device 30.

[0103] When the fourth monitoring device 30 receives the request data from the third monitoring device 30, in step S22 it transmits the request data and battery monitoring information (transfer section). At this time, the fourth monitoring device 30 transmits the request data and battery monitoring information to the second monitoring device 30, which is the transmission destination. Furthermore, the fourth monitoring device 30 transmits the battery monitoring information received from the third monitoring device 30 in addition to the battery monitoring information it has acquired. In other words, the fourth monitoring device 30 transmits the battery monitoring information it has acquired, the electronic monitoring information acquired by the first monitoring device 30, and the electronic monitoring information acquired by the third monitoring device 30.

[0104] In this manner, the fourth monitoring device 30 receives the request data via the first monitoring device 30. In this embodiment, in addition to the first monitoring device 30, a fourth monitoring device 30 that receives the request data via the third monitoring device 30 is employed. Furthermore, the fourth monitoring device 30 transmits battery monitoring information to the control device 40 via the second monitoring device 30.

[0105] When the second monitoring device 30 receives the request data from the fourth monitoring device 30, in step S23, it transmits the request data and battery monitoring information. At this time, the second monitoring device 30 transmits the battery monitoring information to the control device 40, which is the transmission destination. Furthermore, the second monitoring device 30 transmits the battery monitoring information received from the fourth monitoring device 30, in addition to the battery monitoring information it has acquired itself.

[0106] That is, the second monitoring device 30 transmits the battery monitoring information it acquires and the electronic monitoring information acquired by the first monitoring device 30, the third monitoring device 30, and the fourth monitoring device 30. Therefore, the second monitoring device 30 compiles the electronic monitoring information acquired by all of the monitoring devices 30 and transmits it to the control device 40. The data that compiles the electronic monitoring information acquired by all of the monitoring devices 30 is also referred to as response data.

[0107] In step S11, the control device 40 receives the response data from the second monitoring device 30 (receiving unit). Thus, the control device 40 receives the battery monitoring information of all the monitoring devices 30. The control device 40 and each monitoring device 30 periodically perform the above-mentioned data communication with the communication partner with which a connection has been established. Then, the control device 40 executes a predetermined process based on the received response data, i.e., the battery monitoring information (step S12). The control device 40 receives the response data via the wireless IC 35, the front-end circuit 36, and the antenna 37. The control device 40 may include a wireless IC 35, a front-end circuit 36, and an antenna 37 for transmission, and a wireless IC 35, a front-end circuit 36, and an antenna 37 for reception.

[0108] Note that the battery monitoring information transmitted in steps S20 to S23 is, for example, already acquired. In other words, it is battery monitoring information held by each monitoring device 30. That is, each monitoring device 30 transmits battery monitoring information acquired in response to previously received request data, etc., in response to the currently received request data. However, the present disclosure is not limited to this. Each monitoring device 30 acquires battery monitoring information upon receiving request data. Then, each monitoring device 30 may transmit the battery monitoring information acquired in response to the currently received request data in response to the currently received request data.

[0109] Furthermore, each monitoring device 30 transmits battery monitoring information upon receiving the request data, which corresponds to battery monitoring information in response to a received request signal.

[0110] In this manner, in the present embodiment, an example is adopted in which each monitoring device 30 acquires battery monitoring information in response to request data including a command requesting transmission of the battery monitoring information. However, the present disclosure is not limited to this. Each monitoring device 30 may acquire battery monitoring information in response to request data including a command requesting acquisition of the battery monitoring information. Also, each monitoring device 30 may acquire battery monitoring information autonomously.

[0111] The battery management system 60 performs at least steps S10, S11, and S22. Moreover, in the battery management method of the present disclosure, the control device 40 transmits request data to the first monitoring device 30 and receives response data from the second monitoring device 30. In the battery management method, the fourth monitoring device 30 receives request data via the first monitoring device 30, and transmits battery monitoring information in response to the received request data to the control device 40 via the second monitoring device 30. Note that the battery management system 60 of the present disclosure can also be replaced with a battery management method.

[0112] <Effects> As described above, the fourth monitoring device 30 is disposed at a position farthest from the control device 40 among all the monitoring devices 30. For this reason, the fourth monitoring device 30 is more likely to fail in wireless communication with the control device 40 than the other monitoring devices 30.

[0113] Therefore, the fourth monitoring device 30 receives the request data via the first monitoring device 30. Moreover, the fourth monitoring device 30 transmits battery monitoring information in response to the received request data to the control device 40 via the second monitoring device 330. In this way, the fourth monitoring device 30 does not directly communicate wirelessly with the control device 40. This allows the battery management system 60 to suppress failures in the transmission of battery monitoring information from the fourth monitoring device 30 to the control device 40. That is, the battery management system 60 can suppress failures in the transmission of response data to the control device 40 more than a configuration in which the fourth monitoring device 30 serves as a transmitting device and transmits response data to the control device 40. Similarly, the battery management system 60 can suppress failures in the transmission of request data transmitted from the control device 40 more than a configuration in which the control device 40 transmits request data to the fourth monitoring device 30. Furthermore, the battery management system 60 can suppress failures in the transmission of response data simply by setting a communication path (transmission destination).

[0114] Furthermore, the response data includes the electronic monitoring information acquired by all of the monitoring devices 30. For this reason, the response data has the longest data length among all the data communicated within the communication path. However, in the battery management system 60, the second monitoring device 30, not the fourth monitoring device 30, transmits the response data. For this reason, the battery management system 60 can reduce wireless communication failures more than a configuration in which the fourth monitoring device 30 transmits the response data.

[0115] In a typical battery management system, a communication path is set in the order in which multiple monitoring devices are arranged. For example, in the case of the arrangement shown in Fig. 5, the communication path is the control device 40, the first monitoring device 30, the second monitoring device 30, the third monitoring device 30, the fourth monitoring device 30, and the control device 40, or vice versa. In this way, the communication path of the battery management system is simplified.

[0116] However, in the battery management system 60, even though the communication path becomes complicated, the fourth monitoring device 30 deliberately uses a communication path that does not directly perform wireless communication with the control device 40. This allows the battery management system 60 to achieve the above-mentioned effects. The battery management method can achieve the same effects as the battery management system 60 described above.

[0117] (Modification) 7, the battery management system 60 may have obstacles 100 disposed around each node. Here, a battery pack 20 is used as an example of the obstacle 100. The periphery of each node refers to an opposing area between the nodes, an adjacent area adjacent to the opposing area between the nodes, etc.

[0118] The obstacle 100 is an object that blocks wireless communication between the nodes. More specifically, the obstacle 100 includes a magnetic member, such as a battery case of the battery cell 22, a conductive bus bar 24, and conductive wiring that connects the battery stacks 21. The obstacle 100 blocks or reflects radio waves of wireless communication. The obstacle 100 can be said to be an object that causes wireless communication between the nodes to fail. Furthermore, the obstacle 100 can be said to be an object that deteriorates communication quality.

[0119] When communication is not established or communication quality is deteriorated below a set value, data transmitted between nodes cannot be transmitted or received, or part of the data is lost. Deterioration of communication quality indicates, for example, a state in which the received signal strength indicator (RSSI) is lower than a predetermined value. In addition, deterioration of communication quality indicates a CRC error state, a state in which data cannot be transmitted or received, or a state in which part of the data is lost. Therefore, in the present disclosure, even if an object is placed between nodes, if it does not deteriorate communication quality, it is not an obstacle 100.

[0120] Second embodiment The second embodiment will be described with reference to FIG. 8. Here, differences from the first embodiment will be mainly described. The second embodiment differs from the first embodiment in the configuration of the monitoring device 30, the configuration of the control device 40, and the inclusion of multiple communication systems. The housing 50 houses the assembled battery 20, the eight monitoring devices 30, and the control device 40. In order to distinguish the eight monitoring devices 30, they are described as 1SBM to 4SBM, and 11SBM, 12SBM, 13SBM, and 14SBM. The 11SBM is referred to as the 11th monitoring device 30. The 12SBM is referred to as the 12th monitoring device 30. The 13SBM is referred to as the 13th monitoring device 30. The 14SBM is referred to as the 14th monitoring device 30. The number of monitoring devices 30 is not limited to the above.

[0121] An obstacle area is formed where an obstacle 100 may be placed. The obstacle area includes a node area that is equal to the outline of two different nodes and an area facing the two nodes. This obstacle area has, for example, a rectangular parallelepiped shape. The obstacle area can also be considered an area that may be a path for radio waves in wireless communication between nodes.

[0122] The obstacle area is formed at least inside the housing 50. However, the obstacle area may also be formed outside the housing 50.

[0123] For example, as shown in FIG. 8, when the monitoring device 30 and the control device 40 are arranged on the same plane within the housing 50, the obstacle area has a rectangular parallelepiped shape with a bottom surface and a top surface that encompass the monitoring device 30 and the control device 40, and the thickness of the monitoring device 30 is the height of the obstacle area.

[0124] Furthermore, for example, if all the monitoring devices 30 are arranged on the same plane inside the housing 50 and the control device 40 is arranged outside the housing 50, the obstacle area includes a rectangular parallelepiped area having bottom and top surfaces that encompass all of the monitoring devices 30, with the thickness of the monitoring devices 30 as its height. In this case, the obstacle area also includes a node area equal to the outer shape of the control device 40, and the opposing areas of each monitoring device 30 and the control device 40, in addition to the rectangular parallelepiped area.

[0125] In these obstacle regions, obstacles 100 such as the assembled battery 20, the battery cases of the battery cells 22, the conductive bus bars 24, and conductive wiring connecting the multiple battery stacks 21 may be placed. Also, a part of the housing 50 may be placed in the obstacle regions. The part of the housing 50 may include protrusions and recesses provided on the housing 50.

[0126] The battery management system 60 has two placement areas 301, 302 for the monitoring device 30. Each of the placement areas 301, 302 is at least a part of the area between the side walls 53, .

[0127] The first arrangement region 301 is provided along the side wall 51. The first arrangement region 301 is provided biased toward the side wall 51 rather than the side wall 52. In other words, the first arrangement region 301 is provided closer to the side wall 51 than the midpoint between the side walls 51 and 52. The first arrangement region 301 is provided in a predetermined range from the side wall 51 toward the side wall 52. The first arrangement region 301 corresponds to the first region.

[0128] On the other hand, the second arrangement region 302 is provided along the side wall 52. The second arrangement region 302 is provided biased toward the side wall 52 rather than the side wall 51. In other words, the second arrangement region 302 is provided on the side wall 52 side rather than the midpoint between the side wall 51 and the side wall 52. The second arrangement region 302 is provided in a predetermined range from the side wall 52 toward the side wall 51. The second arrangement region 302 corresponds to the second region.

[0129] The first arrangement area 301 has the first to fourth monitoring devices 30 arranged therein. The first to fourth monitoring devices 30 are arranged along the side wall 51, as in the above embodiment. The second arrangement area 302 has the eleventh to fourteenth monitoring devices 30 arranged therein. The eleventh to fourteenth monitoring devices 30 are arranged along the side wall 52.

[0130] The present disclosure employs an example having two arrangement regions 301, 302. However, this embodiment may have at least two arrangement regions. Therefore, this embodiment may have three or more arrangement regions. Each arrangement region may be provided along the side walls 53, 54 in the short direction. Each arrangement region may be provided along both the side walls 53, 54 in the short direction and the side walls 51, 52 in the long direction. Each arrangement region may be provided without being provided along the side walls 51 to 54. Also, it is sufficient that at least one monitoring device 30 is provided in each arrangement region.

[0131] The battery pack 20 is arranged between the first arrangement region 301 and the second arrangement region 302. In this battery pack 20, for example, a plurality of battery stacks 21 are arranged side by side in a direction from the side wall 53 to the side wall 54. In each battery stack 21, for example, a plurality of battery cells 22 are arranged side by side in a direction from the side wall 53 to the side wall 54.

[0132] The battery pack 20 has a plurality of battery stacks 21 arranged in two rows. The battery pack 20 includes two stack rows 211, 212 in which, for example, four battery stacks 21 are arranged side by side in a direction from the side wall 53 to the side wall 54. The two stack rows 211, 212 are arranged side by side in a direction from the side wall 51 to the side wall 52. It can also be said that the two stack rows include a first stack row 211 arranged closer to the side wall 51 than to the side wall 52, and a second stack row 212 arranged closer to the side wall 52 than to the side wall 51.

[0133] One end 213 of each battery stack 21 faces the adjacent stack row, and the other end 214 faces the side walls 51, 52. That is, one end 213 of each battery stack 21 in the first stack row 211 faces the second stack row 212, and the other end 214 faces the side wall 51. One end 213 of each battery stack 21 in the second stack row 212 faces the first stack row 211, and the other end 214 faces the side wall 52.

[0134] The end 214 of each battery stack 21 facing the side walls 51, 52 can also be referred to as a wall side end. The end 214 of the battery stack 21 included in the first stack row 211 can also be referred to as the end 214 of the first stack row 211. Similarly, the end 214 of the battery stack 21 included in the second stack row 212 can also be referred to as the end 214 of the second stack row 212.

[0135] Therefore, it can be said that the first to fourth monitoring devices 30 are disposed between an imaginary plane along the end portion 214 of the first stack row 211 and the side wall 51. Similarly, it can be said that the eleventh to fourteenth monitoring devices 30 are disposed between an imaginary plane along the end portion 214 of the second stack row 212 and the side wall 52.

[0136] The first arrangement region 301 and the second arrangement region 302 are provided at both ends of the battery pack 20. Therefore, it can be said that the multiple monitoring devices 30 are arranged side by side at both ends of the battery pack 20. The first to fourth monitoring devices 30 are arranged side by side along one end of the battery pack 20. The eleventh to fourteenth monitoring devices 30 are arranged side by side along the other end of the battery pack 20. Note that each monitoring device 30 may be arranged in an opposing region of the battery pack 20, or outside the opposing region. The opposing region here is an area that faces the battery pack 20 in the direction from the side wall 51 toward the side wall 52.

[0137] As described in the above modified example, the battery pack 20 serves as the obstacle 100. Therefore, it can be said that the obstacle 100 is disposed between the first arrangement region 301 and the second arrangement region 302. Note that the area between the first arrangement region 301 and the second arrangement region 302 refers to the opposing area between the first arrangement region 301 and the second arrangement region 302 and the adjacent area adjacent to the opposing area.

[0138] The above-described configuration of the battery pack 20 and the arrangement of the monitoring devices 30 are merely examples. This embodiment may be adopted with other configurations and arrangements. For example, the monitoring devices 30 may not be arranged between the battery pack 20 and the side walls 51, 52. In this case, the monitoring devices 30 may be arranged overlapping the battery pack 20 (battery stack 21) as shown in FIG. 2. In this case, the first to fourth monitoring devices 30 are arranged, for example, at the end of the side wall 51 side of each battery stack 21 in the first stack row 211. The eleventh to fourteenth monitoring devices 30 are arranged, for example, at the end of the side wall 52 side of each battery stack 21 in the second stack row 212. Furthermore, the battery pack 20 may have the battery stacks 21 arranged in a row.

[0139] The battery management system 60 has two communication systems. The battery management system 60 has a first communication system including the first to fourth monitoring devices 30 arranged in a first arrangement area 301, and a second communication system including the eleventh to fourteenth monitoring devices 30 arranged in a second arrangement area 302. Each communication system includes a receiving device, a transmitting device, and a remote device. In the first communication system, the second monitoring device 30 corresponds to the receiving device, the first monitoring device 30 corresponds to the transmitting device, and the fourth monitoring device 30 corresponds to the remote device. In the second communication system, the twelfth monitoring device 30 corresponds to the receiving device, the eleventh monitoring device 30 corresponds to the transmitting device, and the fourteenth monitoring device 30 corresponds to the remote device.

[0140] Incidentally, the response data has the longest data length among all the data communicated within the communication path. Therefore, it is preferable that the transmitting device is the monitoring device 30 arranged closest to the control device 40. In this embodiment, the first monitoring device 30 and the eleventh monitoring device 30 are used as transmitting devices. This allows the battery management system 60 to reduce failures in wireless communication more than in a configuration in which the other monitoring devices 30 transmit response data. This configuration can also be applied to other embodiments.

[0141] Each monitoring device 30 included in each communication system performs chain communication including the control device 40. Therefore, in the first communication system, chain communication is performed between the first to fourth monitoring devices 30 and the control device 40. The communication path in this case is the control device 40, the second monitoring device 30, the fourth monitoring device 30, the third monitoring device 30, the first monitoring device 30, and the control device 40. On the other hand, in the second communication system, chain communication is performed between the eleventh to fourteenth monitoring devices 30 and the control device 40. The communication path in this case is the control device 40, the twelfth monitoring device 30, the fourteenth monitoring device 30, the thirteenth monitoring device 30, the eleventh monitoring device 30, and the control device 40.

[0142] In the present embodiment, an example having two communication systems is used. However, the present disclosure may have three or more communication systems. Also, each communication system may include four or more nodes.

[0143] The control device 40 wirelessly communicates with the monitoring device 30 of each communication system. Therefore, in this embodiment, a control device 40 having the same number of communication functions as the number of communication systems is adopted. That is, the control device 40 has an antenna 42, a front-end circuit 43, and a wireless IC 44 for the first communication system, and an antenna 42, a front-end circuit 43, and a wireless IC 44 for the second communication system.

[0144] However, the present embodiment is not limited thereto, and may be adopted even for a control device 40 including only one set of the antenna 42, the front-end circuit 43, and the wireless IC 44. In this case, the battery management system 60 communicates with each of the monitoring devices 30 of the first system and with each of the monitoring devices 30 of the second system in a time-division manner.

[0145] The control device 40 is disposed between the battery pack 20 and the side wall 53. The control device 40 may be disposed so as to be stacked on the battery pack 20 (battery stack 21).

[0146] The battery management system 60 of the second embodiment can achieve the same effects as the above-mentioned embodiment. Moreover, the battery management system 60 divides the communication system into multiple systems. Therefore, if the total number of monitoring devices 30 is the same, the battery management system 60 can shorten the data length of each response data compared to a configuration in which wireless communication is performed using a single communication system. Therefore, the battery management system 60 can reduce wireless communication failures compared to a configuration in which wireless communication is performed using a single communication system. Moreover, by dividing the communication system into multiple systems, the battery management system 60 can easily prevent obstacles 100 from being placed between nodes.

[0147] Third embodiment The third embodiment will be described with reference to Fig. 9. Here, differences from the second embodiment will be mainly described. The third embodiment differs from the second embodiment in the configuration of the communication system. Note that the battery pack 20 is not shown in Fig. 9.

[0148] 9, an obstacle 100 is placed between the 13th monitoring device 30 and the 14th monitoring device 30. For this reason, there is a high possibility that wireless communication will fail between the 13th monitoring device 30 and the 14th monitoring device 30. On the other hand, no obstacle 100 is placed between the 14th monitoring device 30 and the third monitoring device 30 or between the 14th monitoring device 30 and the fourth monitoring device 30.

[0149] Therefore, in the battery management system 60, a communication path is set so as to avoid wireless communication being blocked by the obstacle 100. That is, in the battery management system 60, a communication path is set so that the 14th monitoring device 30 arranged in the second arrangement area 302 communicates wirelessly with the third monitoring device 30 and the fourth monitoring device 30. Therefore, the first communication system includes the 14th monitoring device 30 in addition to the first to fourth monitoring devices 30. On the other hand, the second communication system does not include the 14th monitoring device 30, but includes the 11th to 13th monitoring devices 30.

[0150] The fourth monitoring device 30 and the fourteenth monitoring device 30 are at the same distance from the control device 40. The fourth monitoring device 30 and the fourteenth monitoring device 30 are at a greater distance from the control device 40 than the first to third monitoring devices 30. Therefore, in the first communication system, the fourth monitoring device 30 and the fourteenth monitoring device 30 correspond to distant devices. In addition, in the first communication system, the third monitoring device 30 corresponds to a receiving device, and the first monitoring device 30 corresponds to a transmitting device. In this way, the fourteenth monitoring device 30, whose wireless communication is obstructed by the obstacle 100, is bypassed by a monitoring device 30 that does not pass through the obstacle 100 and wireless communication is performed. The monitoring devices 30 that do not pass through the obstacle 100 here are the third and fourth monitoring devices 30.

[0151] Many components that may become obstacles 100 are disposed inside the battery pack 11 (housing 50). However, in the battery management system 60, a communication path is set to avoid wireless communication being blocked by the obstacles 100. Therefore, the battery management system 60 can suppress failure of wireless communication. The battery management system 60 of this embodiment can achieve the same effects as the second embodiment.

[0152] In this embodiment, a configuration is adopted in which an obstacle 100 is placed between the monitoring devices 30. However, this embodiment is not limited to this, and a configuration in which an obstacle 100 is placed between the monitoring devices 30 and the control devices 40 can also be adopted. In addition, when an obstacle 100 is present between the nodes, it can be said that the nodes are set to wirelessly communicate so as to bypass the obstacle.

[0153] In this embodiment, two communication systems are adopted. However, this embodiment can also be adopted in a configuration having one communication system or three or more communication paths. In addition, the technical content of this embodiment can also be applied to other embodiments.

[0154] (Fourth embodiment) The fourth embodiment will be described with reference to Fig. 10. Here, differences from the second embodiment will be mainly described. The fourth embodiment differs from the second embodiment in that a bus bar is provided as an obstacle 100 between the arrangement areas. Note that the battery pack 20 is not shown in Fig. 10.

[0155] 10, in the battery management system 60, a positive electrode bus bar 281 and a negative electrode bus bar 283 are arranged between a first arrangement region 301 and a second arrangement region 302. The positive electrode bus bar 281 and the negative electrode bus bar 283 are arranged between a first stack row 211 and a second stack row 212. Note that the space between the first stack row 211 and the second stack row 212 refers to an opposing region between the first stack row 211 and the second stack row 212, an adjacent region adjacent to the opposing region, or the like.

[0156] For example, the positive bus bar 281 and the negative bus bar 283 are plate-shaped bus bars. The positive bus bar 281 and the negative bus bar 283 are provided along the arrangement direction of the battery stacks 21 in each stack row 211, 212. Furthermore, each bus bar 281, 283 extends in the same direction as the arrangement direction of the multiple battery cells 22 in the battery stack 21.

[0157] The positive bus bar 281 is electrically connected to the control device 40 and the battery cell 22 with the highest potential. The positive bus bar 281 is electrically connected to the battery cell 22 with the highest potential via a connection bus bar 282. The negative bus bar 283 is electrically connected to the control device 40 and the battery cell 22 with the lowest potential. The negative bus bar 283 is electrically connected to the battery cell 22 with the lowest potential via a connection bus bar 284.

[0158] The battery cell 22 with the highest potential is the battery cell 22 with the highest potential among the multiple battery cells 22 included in the battery pack 20. On the other hand, the battery cell 22 with the lowest potential is the battery cell 22 with the lowest potential among the multiple battery cells 22 included in the battery pack 20.

[0159] Positive bus bar 281 may be configured as an integral part with connection bus bar 282. Similarly, negative bus bar 283 may be configured as an integral part with connection bus bar 284.

[0160] The battery management system 60 of this embodiment can achieve the same effects as those of the second embodiment. The technical content of this embodiment can also be applied to the other embodiments.

[0161] Fifth embodiment The fifth embodiment will be described with reference to Figs. 11 and 12. Here, differences from the first embodiment will be mainly described. The fifth embodiment differs from the first embodiment in that the communication path is switched. Note that this embodiment employs an example in which the monitoring device 30 and the control device 40 are arranged in the same manner as in Fig. 5.

[0162] As described above, a communication path including the remote device, the receiving device, and the transmitting device is set in advance in the battery management system 60. Here, it is assumed that the communication path used in the first embodiment (FIG. 5) is set in advance.

[0163] Moreover, the communication route is set so that wireless communication can be performed normally, taking into consideration the obstacles 100. Usually, the communication route is set in a factory, a dealer, or the like. The communication route set here can be called an initial route, which is the initial value of the communication route. Moreover, the environment in which the initial route is set can be called an initial setting environment.

[0164] However, the battery management system 60 may be mounted on a moving object such as a vehicle. In this case, the surrounding environment of the battery management system 60 changes as the vehicle moves. In the following, a vehicle is used as an example of a moving object.

[0165] In the battery management system 60, the communication state of wireless communication between nodes changes due to changes in the surrounding environment. In other words, the success rate of transmission and reception in wireless communication may vary depending on the surrounding environment.

[0166] Therefore, even if the battery management system 60 has a communication path set so that wireless communication can be performed normally, the success rate of transmission and reception in wireless communication varies as the vehicle moves. In other words, the battery management system 60 may no longer have an optimal communication path as the vehicle moves. Note that the optimal communication path is a communication path that allows normal wireless communication.

[0167] Therefore, each monitoring device 30 and control device 40 performs a switching process to switch a preset communication path. Each monitoring device 30 and control device 40 starts the flowchart shown in Fig. 11 when, for example, the ignition switch of the vehicle is switched from off to on. Each monitoring device 30 and control device 40 performs the flowchart of Fig. 11. In the following, each monitoring device 30 and control device 40 will be collectively referred to as a node.

[0168] In S30, each node performs a transmission / reception process to check the communication quality. That is, each node performs wireless communication with two communication partners on a predetermined communication path. For example, the third monitoring device 30 receives data transmitted from the first monitoring device 30 and transmits data to the fourth monitoring device 30. The data transmitted and received here can be called evaluation data. For example, response data or request data (request signal) can be adopted as the evaluation data. However, the evaluation data is not limited to these.

[0169] In step S32, each node performs communication quality evaluation as communication quality processing (communication quality processing unit). Each node evaluates the communication quality of its own wireless communication. Each node evaluates the quality of the current communication based on the transmission and reception results in step S30. Each node evaluates whether the communication quality is normal or has deteriorated. Then, in step S34, each node accumulates the evaluation result of communication quality as communication performance (accumulation unit).

[0170] In more detail, each node may evaluate the communication quality as degraded, for example, when it is unable to receive response data. Each node may evaluate the communication quality as degraded, for example, when it is able to receive data but detects a communication error by a test performed at the time of reception, for example, a test using an error detection code. Each node may evaluate the communication quality as degraded, for example, when a retransmission process is required. In other words, when communication is not established, the communication quality may be evaluated as degraded. Each node may evaluate the communication quality as degraded, for example, when the received signal strength indicator (RSSI) is lower than a predetermined value. RSSI is an abbreviation for Received Signal Strength Indicator. Each node evaluates the communication quality as normal if the evaluation criteria are met.

[0171] Each node may obtain information on the reception status of the request data from the communication partner node as part of the communication data, and evaluate the communication quality. Each node evaluates the communication quality based on the information on the reception status of the request data and / or the information on the reception status of the response data, and accumulates the evaluation result as a communication record.

[0172] Each node accumulates a communication record of normal communication quality or a communication record of degraded communication quality for each process of step S34. In this manner, each node accumulates communication records. The communication records can be considered as accumulated evaluation results.

[0173] Then, in step S36, each node judges whether the communication record is greater than the threshold (judgment unit). Each node compares the communication record with the threshold to judge whether to switch the communication path from the initial path. The threshold is a value for judging whether wireless communication can be performed normally on the communication path. The threshold can also be said to be a value for judging whether a state in which wireless communication cannot be performed normally on the communication path continues.

[0174] When each node determines that the communication result is greater than the threshold, it determines that wireless communication cannot be performed normally on the initial route, and proceeds to step S38. In other words, when each node determines that the communication result is greater than the threshold, it determines to switch the communication route from the initial route.

[0175] On the other hand, if each node does not determine that the communication result is greater than the threshold, it determines that wireless communication can be performed normally even on the initial route and ends the flowchart in Fig. 11. In other words, if each node does not determine that the communication result is greater than the threshold, it determines not to switch the communication route from the initial route.

[0176] Each node switches the communication path in step S38 (switching unit). Each node switches the communication path depending on the communication quality. That is, each node switches the communication path when the communication quality is such that it is determined that switching of the communication path is necessary.

[0177] For example, the communication path (initial path) shown in Fig. 5 is switched to the communication path shown in Fig. 12. In Fig. 12, a communication path is adopted in which wireless communication is performed in the order of the control device 40, the first monitoring device 30, the fourth monitoring device 30, the second monitoring device 30, the third monitoring device 30, and the control device 40.

[0178] In this case, the first to third monitoring devices 30 change the ID of the transmission destination. The first monitoring device 30 changes the ID of the transmission destination from the ID of the third monitoring device 30 to the ID of the fourth monitoring device 30. The second monitoring device 30 changes the ID from the ID of the control device 40 to the ID of the third monitoring device 30. The third monitoring device 30 changes the ID from the ID of the fourth monitoring device 30 to the ID of the control device 40.

[0179] As a result, the transmitting device is changed from the second monitoring device 30 to the third monitoring device. However, the distant device in the changed communication path is still the fourth monitoring device 30, which was the same as in the initial path. Therefore, even if the communication path is changed, the fourth monitoring device 30 does not directly communicate wirelessly with the control device 40.

[0180] A plurality of communication paths that are candidates for the changed communication path may be stored in advance in the ROM of each node. In this case, each node selects one communication path from the plurality of communication paths in step S38 and sets it as the new communication path. Also, each node may select one communication path from the plurality of communication paths based on communication performance in step S38 and set it as the new communication path. The communication path stored in advance may also be called a path candidate.

[0181] Each node may create a new communication path based on the communication record and set it as a new communication path. In this case, it is not necessary to store multiple path candidates in the ROM of each node. Therefore, it is not necessary for each node to increase the ROM capacity to store the path candidates.

[0182] Furthermore, when a predetermined condition is satisfied, the battery management system 60 does not require each monitoring device 30 to acquire battery monitoring information. The predetermined condition is, for example, when the vehicle is not traveling. Thus, the control device 40 may perform the switching process only when the vehicle is not traveling. A period when the vehicle is not traveling is a period when it is not necessary to acquire battery monitoring information. In other words, the control device 40 may perform the switching process only when it is no longer necessary to acquire battery monitoring information. It can also be said that the control device 40 performs the switching process when it detects that the vehicle is not traveling.

[0183] The non-driving state includes, for example, when the ignition switch is off, when the system main relay is off, and when the battery pack 20 is at rest. The system main relay is, for example, a relay provided between the battery pack 11 and the PCU 12. The non-driving state can also include when the vehicle is stopped, when the driver gets out of the vehicle, and when each door of the vehicle is locked. Therefore, when the control device 40 detects that the ignition switch is off, it assumes that the vehicle is not driving and performs a switching process. By performing a switching process when the battery management system 60 is not driving, it is possible to prevent the battery pack 20 (battery stack 21, battery cells 22) from going into an unmonitored state while the vehicle is driving.

[0184] The control device 40 may perform the switching process at predetermined time intervals when the ignition switch is on. This allows the battery management system 60 to easily follow the changes in the vehicle's surrounding environment with respect to the communication path. In other words, the battery management system 60 can normally perform wireless communication between the nodes even if the vehicle's surrounding environment changes from the initially set environment.

[0185] The control device 40 may perform the switching process each time the number of times the ignition switch is switched from off to on reaches a predetermined number. This allows the battery management system 60 to easily follow the communication path to changes in the surrounding environment of the vehicle while preventing the battery pack 20 from going unmonitored while the vehicle is traveling. In other words, the battery management system 60 can prevent the battery pack 20 from going unmonitored while the vehicle is traveling, compared to a case in which the switching process is performed at predetermined time intervals when the ignition switch is on. In addition, the battery management system 60 can easily follow the communication path to changes in the surrounding environment of the vehicle, compared to a case in which the switching process is performed while the vehicle is not traveling or when the ignition switch is switched from off to on.

[0186] The timing of the switching process is not limited to the above, and the control device 40 may perform the switching process at a timing different from the above timing.

[0187] The battery management system 60 of this embodiment can achieve the same effects as those of the first embodiment. Furthermore, the battery management system 60 can perform normal wireless communication between the nodes even if the surrounding environment of the vehicle changes from the initial setting environment. The technical content of this embodiment can also be applied to the other embodiments.

[0188] It can be said that each node of the battery management system 60 uses communication quality as information for judging whether or not switching of the communication path is necessary. The communication quality is information obtained by actually performing wireless communication as described above. Therefore, each node can judge whether or not switching of the communication path is necessary based on the actual state of wireless communication. Therefore, each node can appropriately switch the communication path. In other words, each node can suppress unnecessary switching of the communication path and failure to switch the communication path when switching is necessary.

[0189] Moreover, the battery management system 60 can suppress erroneous determination of whether or not to switch the communication path by performing steps S34 and S36. However, this embodiment is not limited to this, and steps S34 and S36 can be omitted. Each node may perform step S38 when the evaluation result of the communication quality obtained in step S32 is a result that is deemed necessary to switch the communication path. The result that is deemed necessary to switch the communication path is, for example, communication quality deterioration. This allows the battery management system 60 to immediately switch the communication path. Note that, in this embodiment, as an example, an example is adopted in which all nodes perform the switching process. However, the present disclosure is not limited to this, and can be adopted as long as at least one of each monitoring device 30 and the control device 40 performs the switching process. For example, only the control device 40 may perform the switching process. In other words, can be adopted as long as at least one of each monitoring device 30 and the control device 40 performs the communication quality evaluation (S32) and the switching of the communication path (S38).

[0190] Sixth embodiment The sixth embodiment will be described with reference to Fig. 13. Here, differences from the first embodiment will be mainly described. The sixth embodiment differs from the first embodiment in that it is applied to an inspection system.

[0191] <Inspection system> The above-described assembled battery 20 (battery cells 22) is inspected (diagnosed) by inspection equipment 80 while removed from the vehicle 10, and a determination is made as to whether it can be reused. As shown in Fig. 13, the inspection equipment 80 constructs an inspection system 90 together with a battery management system 60 that has been removed from the vehicle 10 together with the assembled battery 20, and inspects the assembled battery 20. The inspection system 90 includes at least one battery management system 60 that has been removed from the vehicle 10, and the inspection equipment 80.

[0192] Although the inspection of the battery cells 22 by the inspection equipment 80 may be performed on a battery management system 60 basis, it is more efficient to perform the inspection collectively for a plurality of battery management systems 60. In the example shown in Fig. 13, the inspection system 90 includes three battery management systems 60 (60A, 60B, 60C), and the inspection equipment 80 collectively inspects the battery cells 22 corresponding to the battery management systems 60A, 60B, 60C.

[0193] Inspection by the inspection equipment 80 is performed in a workplace such as a factory, a dealer, or a warehouse. In a factory, there are various obstacles 100 such as a production line, equipment, machines, walls, and shelves. Similarly, in a dealer or a warehouse, there are various obstacles 100 such as equipment, machines, walls, and shelves. Therefore, in such a workplace, it is difficult to wirelessly communicate between the inspection equipment 80 and each monitoring device 30 individually. In other words, it is difficult to stabilize the state of wireless communication between the inspection equipment 80 and each monitoring device 30.

[0194] Furthermore, the inspection by the inspection equipment 80 collectively inspects the battery cells 22 corresponding to a plurality of battery management systems 60. Therefore, the number of battery cells 22 inspected by the inspection equipment 80 is greater than the number of battery cells 22 mounted on one vehicle. Therefore, wireless communication between the inspection equipment 80 and each monitoring device 30 individually requires a lot of man-hours.

[0195] In the inspection system 90, the inspection equipment 80 performs chain communication including the multiple monitoring devices 30 by wireless communication to acquire battery monitoring information for inspection. As shown in Fig. 13, the inspection equipment 80 and the multiple monitoring devices 30 perform wireless communication by setting a communication path shown by a dashed line before the inspection.

[0196] The monitoring device 30 is collected from multiple battery management systems 60. Therefore, the communication path during inspection by the inspection equipment 80 is different from the communication path when the equipment is mounted on the vehicle. The communication path during inspection by the inspection equipment 80 corresponds to the inspection communication path.

[0197] 13, a communication path example during inspection employs a communication path in which wireless communication is performed in the order of the inspection device 80, the 20th monitoring device 30 to the 25th monitoring device 30, the 28th monitoring device 30, the 27th monitoring device 30, the 26th monitoring device 30, and the inspection device 80. Note that the 20th monitoring device 30 to the 25th monitoring device 30 indicate that wireless communication is performed in the order of the 20th monitoring device 30, the 21st monitoring device 30, the 22nd monitoring device 30, the 23rd monitoring device 30, the 24th monitoring device 30, and the 25th monitoring device 30.

[0198] In this case, the 26th monitoring device 30 corresponds to a transmitting device during inspection. The 20th monitoring device 30 corresponds to a receiving device during inspection. The 28th monitoring device 30 corresponds to a remote device during inspection. The 28th monitoring device 30 is located at a position farthest from the inspection equipment 80 among all the monitoring devices 30. The 28th monitoring device 30 communicates wirelessly with the 25th monitoring device 30 and the 27th monitoring device 30, but does not directly communicate wirelessly with the inspection equipment 80.

[0199] The battery monitoring information includes at least the battery information and fault diagnosis information described above. The battery monitoring information may further include manufacturing history information. The manufacturing history information is information indicating the manufacturing history of the assembled battery 20, the battery stack 21, the battery cells 22, etc. The manufacturing history information is, for example, a manufacturing ID (serial number) and manufacturing date and time. Furthermore, the inspection equipment 80 may acquire only the manufacturing history information without acquiring the battery monitoring information. In other words, the multiple monitoring devices 30 may transmit the battery monitoring information and / or the manufacturing history information by wireless communication.

[0200] The inspection equipment 80 inspects the deterioration state and / or abnormalities of the battery cells 22 and determines whether or not they can be reused based on the inspection results. The inspection equipment 80 determines whether the battery cells 22 (battery pack 20) ​​should be reused or recycled. The inspection equipment 80 may be called an inspection tool, a diagnostic device, an external device, etc.

[0201] The battery management system 60 may include at least the monitoring device 30 and the sensor 70 when removed from the vehicle 10 together with the battery pack 20. In other words, the battery management system 60 may be configured to transmit battery monitoring information to the inspection equipment 80 by wireless communication. Therefore, the battery management system 60 may not include the housing 50, and may not include the control device 40. Of course, the battery management system 60 may have the same configuration as when mounted on the vehicle. When the control device 40 is not included, the inspection equipment 80 may obtain the cell current from a current sensor.

[0202] <Testing method> The inspection equipment 80 may obtain the battery monitoring information held by the monitoring device 30 via wireless communication to inspect (diagnose) the deterioration state and abnormality of the battery cells 22 and determine whether or not they can be reused when the assembled battery 20 is not connected to a load (not shown), i.e., when no current is being applied to the load. In other words, the inspection equipment 80 may inspect (diagnose) the deterioration state and abnormality of the battery cells 22 based on the battery monitoring information held by the monitoring device 30 before wireless communication is established between the inspection equipment 80 and the battery cells 22 and determine whether or not they can be reused. The inspection equipment 80 may determine whether or not they can be reused based on the battery monitoring information obtained by the monitoring device 30 when no current is being applied to the load. For example, the inspection equipment 80 may determine whether or not they can be reused based on the cell voltage, i.e., the open circuit voltage.

[0203] The inspection equipment 80 inspects (determines) the deterioration state of the battery cell 22 based on, for example, the acquired manufacturing history information. The inspection equipment 80 inspects the deterioration state of the battery cell 22 based on, for example, the time elapsed since the manufacturing date. The inspection equipment 80 may inspect the presence or absence of an abnormality based on fault diagnosis information. The inspection equipment 80 may estimate the internal resistance and SOH of the battery cell 22 based on battery information such as the cell voltage, and inspect the deterioration state of the battery cell 22. For example, the internal resistance increases as the battery cell 22 deteriorates.

[0204] The inspection equipment 80 may inspect (diagnose) the deterioration state and abnormality of the battery cells 22, including the inspection results when the assembled battery 20 is in a powered state, and determine whether or not the battery cells can be reused. Specifically, the inspection equipment 80 may obtain battery monitoring information from the monitoring device 30 while the assembled battery 20 is connected to a load, that is, while power is being applied to the load, and determine whether or not the battery cells can be reused.

[0205] The inspection equipment 80 inspects the deterioration state of the battery cells 22 by estimating the internal resistance and SOH of the battery cells 22 based on the acquired battery information, for example. The inspection equipment 80 inspects the battery cells 22 and the monitoring device 30 for abnormalities based on the fault diagnosis information, for example. When inspecting multiple battery management systems 60 collectively, the assembled batteries 20 (battery stacks 21) of the multiple battery management systems 60 are connected in series, for example.

[0206] In any of the above-mentioned inspections, each monitoring device 30 and the inspection equipment 80 first executes a connection process for wireless communication with the communication partner. The connection process here is the same as the connection process described in the first embodiment. In the following, as an example, an example in which each monitoring device 30 transmits battery monitoring information is adopted.

[0207] After the connection process is completed, first, the testing equipment 80 transmits a test instruction signal to the twentieth monitoring device 30, which is the testing time receiving device. Each monitoring device 30 transmits battery monitoring information to a transmission partner on a preset communication path during testing. That is, when each monitoring device 30 directly or indirectly receives a test instruction signal transmitted from the testing equipment 80, it transmits battery monitoring information in response to the test instruction signal. Also, each monitoring device 30 transmits the test instruction signal together with the battery monitoring information to the transmission partner.

[0208] The 28th monitoring device 30, which is a remote device during inspection, receives the inspection instruction signal via the 20th monitoring device 30. The 28th monitoring device 30 transmits battery monitoring information in response to the received inspection instruction signal to the inspection equipment 80 via the 26th monitoring device 30.

[0209] The monitoring devices 30 other than the 20th monitoring device 30 transmit the received battery monitoring information in addition to the battery monitoring information they have acquired. Thus, the 26th monitoring device 30 transmits the battery monitoring information acquired by all the monitoring devices 30 to the testing equipment 80.

[0210] This battery monitoring information is the battery monitoring information held by the monitoring device 30 before the connection process is performed. However, each monitoring device 30 may obtain the battery monitoring information after the connection process is completed.

[0211] The inspection equipment 80 inspects (diagnoses) the deterioration state and abnormality of the battery cells 22 based on the acquired battery monitoring information, and judges whether or not the battery cells 22 can be reused. The situation in which the assembled battery 20 is inspected by the inspection equipment 80 with the assembled battery 20 and the battery management system 60 removed from the mobile body is not limited to an inspection of whether or not the assembled battery 20 can be reused. For example, the inspection may be performed during the manufacture of the battery pack 11 or at a repair shop. During these inspections, the monitoring device 30 may transmit the battery monitoring information included in a packet during the period in which the wireless communication connection process is performed with the communication partner.

[0212] Examples of reuse applications include fixed household power sources, power plants that generate solar or geothermal power, and storage batteries for disaster prevention. In addition, examples of reuse applications include fixed backup power sources for offices, stores, factories, etc.

[0213] As described above, the inspection system 90 can reduce failures in transmitting the battery monitoring information to the control device 40 more than in a configuration in which the 28th monitoring device 30 serves as an in-inspection transmitting device and transmits the battery monitoring information to the control device 40. Note that the technical content of this embodiment can also be applied to other embodiments.

[0214] (Other embodiments) The disclosure in this specification and drawings, etc. is not limited to the exemplified embodiments. The disclosure includes the exemplified embodiments and modifications by those skilled in the art based thereon. For example, the disclosure is not limited to the combination of parts and / or elements shown in the embodiments. The disclosure can be implemented by various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure includes the omission of parts and / or elements of the embodiments. The disclosure includes the substitution or combination of parts and / or elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. Some disclosed technical scopes are indicated by the description of the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the description of the claims.

[0215] The disclosure in the specification and drawings is not limited by the claims. The disclosure in the specification and drawings includes the technical ideas described in the claims, and extends to more diverse and broader technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure in the specification and drawings without being bound by the claims.

[0216] When an element or layer is referred to as being "on," "coupled," "connected," or "coupled," it may be directly coupled, connected, or coupled to another element or layer, and intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly coupled," "directly connected," or "directly coupled" to another element or layer, no intervening elements or layers are present. Other words used to describe relationships between elements should be construed in a similar manner (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.). As used in this specification, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0217] Spatially relative terms such as "inside," "outside," "back," "bottom," "low," "top," "top," and the like are utilized herein to facilitate the description of the relationship of one element or feature to other elements or features as depicted in the figures. Spatially relative terms may be intended to encompass different orientations of the device during use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "directly below" other elements or features would be oriented "above" the other elements or features. Thus, the term "bottom" can encompass both an orientation of top and bottom. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used in this specification would be interpreted accordingly.

[0218] The apparatus, systems, and methods described herein may be implemented by a special purpose computer having a processor programmed to perform one or more functions embodied in a computer program. Alternatively, the apparatus, systems, and methods described herein may be implemented by a special purpose hardware logic circuit. Alternatively, the apparatus, systems, and methods described herein may be implemented by one or more special purpose computers comprising a processor that executes a computer program and one or more hardware logic circuits. Also, the computer program may be stored on a computer-readable non-transitory tangible recording medium as instructions that are executed by the computer.

[0219] For example, although an example in which the monitoring device 30 includes the microcomputer 34 has been described, the present invention is not limited to this. As shown in Fig. 14, a battery management system 60 may be adopted in which the monitoring device 30 does not include the microcomputer 34. Fig. 14 corresponds to Fig. 4. In this configuration, the wireless IC 35 transmits and receives data to and from the monitoring IC 33. The schedule control of sensing and self-diagnosis by the monitoring IC 33 may be executed by the wireless IC 35 or may be executed by the main microcomputer 45 of the control device 40.

[0220] Although an example in which a monitoring device 30 is provided for each battery stack 21 has been shown, the present invention is not limited to this. For example, one monitoring device 30 may be provided for multiple battery stacks 21. Multiple monitoring devices 30 may be provided for one battery stack 21.

[0221] Although an example in which the battery pack 11 includes one control device 40 has been described, the present invention is not limited to this. A plurality of control devices 40 may be included. In other words, the battery pack 11 may include one or more monitoring devices 30 and one or more control devices 40. The battery management system 60 may include a plurality of wireless communication systems established between one control device 40 and one or more monitoring devices 30.

[0222] Although an example in which the monitoring device 30 includes one monitoring IC 33 has been described, the present invention is not limited to this. A plurality of monitoring ICs 33 may be included. In this case, a wireless IC 35 may be provided for each monitoring IC 33, or one wireless IC 35 may be provided for the plurality of monitoring ICs 33.

[0223] The arrangement and number of battery stacks 21 and battery cells 22 constituting battery pack 20 are not limited to the above example. In battery pack 11, the arrangement of monitoring device 30 and / or control device 40 is not limited to the above example. [Explanation of symbols]

[0224] 10...vehicle, 11...battery pack, 12...PCU, 13...MG, 14...ECU, 15...battery, 20...battery pack, 21...battery stack, 22...battery cell, 23...busbar unit, 24...busbar, 25...positive terminal, 26...negative terminal, 27...busbar cover, 30...monitoring device, 31, 311, 312, 313...power supply circuit, 32...multiplexer, 33...monitoring IC, 34...microcontroller, 35...wireless IC, 36...front-end circuit, 37...antenna, 40...control device, 41, 411, 412...power supply circuit, 42...antenna, 43...front-end circuit, 44...wireless IC, 45...main microcontroller, 46...sub-microcontroller, 50...casing, 60...battery management system, 70...sensor, 80...inspection tool, 90...inspection system

Claims

1. three or more monitoring devices (30) arranged in a housing (50) together with the batteries (20, 21, 22) and configured to acquire and monitor battery monitoring information including information indicating the state of the batteries; a control device (40) that wirelessly communicates with the two monitoring devices and executes a predetermined process based on the battery monitoring information in each monitoring device; A battery management system that wirelessly communicates over a communication path from the control device to the control device via each monitoring device, The control device includes: A transmission unit (S10) that transmits a request signal requesting transmission of the battery monitoring information to a receiving device that is one of the monitoring devices; a receiving unit (S11) that receives the battery monitoring information of all the monitoring devices from a transmitting device that is one of the monitoring devices and is different from the receiving device; A battery management system comprising: a remote device, which is a monitoring device different from the receiving device and the transmitting device and is located at a distance farther from the control device than the receiving device and the transmitting device, and which receives the request signal via the receiving device and transmits the battery monitoring information in response to the received request signal to the control device via the transmitting device.

2. The battery management system according to claim 1, At least one of the control device and the monitoring device is a communication quality processing unit (S32) for evaluating a communication quality of the wireless communication in the communication device itself; A switching unit (S38) that switches the communication path depending on the communication quality.

3. The battery management system according to claim 2, The switching unit selects one of the plurality of communication paths stored in advance and switches the communication path.

4. The battery management system according to claim 2 or 3, A storage unit (S34) for storing the evaluation result of the communication quality; and a determination unit (S36) that determines whether or not to switch the communication path based on the accumulated evaluation result, The switching unit switches the communication path when the determination unit determines that the communication path should be switched.

5. The battery management system according to any one of claims 2 to 4, the monitoring device does not need to acquire the battery monitoring information when a predetermined condition is satisfied, A battery management system in which the control device and the monitoring device switch the communication path only when it becomes unnecessary to acquire the battery monitoring information.

6. The battery management system according to any one of claims 1 to 5, A battery management system, wherein the transmitting device is disposed closest to the control device among all the monitoring devices.

7. The battery management system according to any one of claims 1 to 6, The housing includes: It has two opposing side walls, The monitoring device may include a first area along one of the side walls and a second area along the other of the side walls, At least one of the monitoring devices is disposed in each of the first area and the second area.

8. The battery management system according to claim 7, The battery management system further comprises an obstacle (100, 281 to 284) that blocks the wireless communication and is disposed between the first area and the second area.

9. The battery management system according to any one of claims 1 to 7, The communication path is set to avoid interference with the wireless communication caused by obstacles.

10. The battery management system according to any one of claims 1 to 9, A battery management system including a plurality of communication systems each including the receiving device, the transmitting device, and the remote device.

11. The battery management system according to any one of claims 1 to 10, which is mounted on a moving body, In a state where the battery is removed from the moving object, Each monitoring device wirelessly communicates with the testing device along a testing communication path from the testing device (80) to the testing device; A battery management system in which an inspection time remote device, which is located at the farthest position from the inspection equipment among all monitoring devices, receives an inspection instruction signal through an inspection time receiving device that received the inspection instruction signal from the inspection equipment, and transmits the battery monitoring information and / or the battery manufacturing history information in response to the received inspection instruction signal to the inspection equipment through an inspection time transmitting device, which is a monitoring device different from the inspection time receiving device.

12. three or more monitoring devices (30) arranged in a housing (50) together with the batteries (20, 21, 22) and configured to acquire and monitor battery monitoring information including information indicating the state of the batteries; a control device (40) that wirelessly communicates with the two monitoring devices and executes a predetermined process based on the battery monitoring information in each monitoring device; A battery management method for managing the battery by wireless communication along a communication path from the control device via each monitoring device to the control device, The control device includes: transmitting a request signal to a receiving device which is one of the monitoring devices, requesting transmission of the battery monitoring information; receiving the battery monitoring information of all the monitoring devices from a transmitting device which is one of the monitoring devices and is different from the receiving device; A battery management method in which a remote device, which is a monitoring device different from the receiving device and the transmitting device and is located at a distance farther from the control device than the receiving device and the transmitting device, receives the request signal via the receiving device and transmits the battery monitoring information in response to the received request signal to the control device via the transmitting device.

Images