Surveillance system

Abstract

To provide a monitoring system capable of reducing power consumption in a control device while maintaining communication between the control device and a plurality of monitoring devices even in a non-operating state of a monitored apparatus.SOLUTION: In an operating state in which a battery pack 20 provides power to an on-vehicle system, a control device 40 serves as a communication master unit and wirelessly communicates with a plurality of monitoring devices 30, which are communication slave units, via individually established communication connections. In a non-operating state of the battery pack 20, the control device 40 serves as the communication mater unit for only one of the plurality of monitoring devices 30, and one of the plurality of monitoring devices 30 plays the role of the communication mater unit for one of the other monitoring devices 30 in turn. In this way, by switching a communication form between the control device 40 and the plurality of monitoring devices 30 depending on whether the battery pack 20 is in the operating or non-operating state, power consumption in the control device 40 can be reduced while communication between the control device 40 and the plurality of monitoring devices 30 is maintained.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a monitoring system for monitoring a monitored device such as a battery pack as the monitored device.

Background Art

[0002] For example, Patent Document 1 describes a battery control system including a plurality of battery cell management devices provided corresponding to respective ones of a plurality of battery cell groups and each configured to acquire measurement results regarding the state of charge of battery cells of the corresponding battery cell group, and a battery pack management device configured to perform wireless communication with the plurality of battery cell management devices.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described battery control system, when the main switch of the vehicle is turned off and the battery pack is in a non-operating state where there is no need to supply power from the battery pack to the in-vehicle system, if the wireless communication between the battery pack management device and each battery cell management device stops, when the main switch of the vehicle is turned on and the battery pack becomes operational, the battery pack management device and each battery cell management device need to establish mutual communication connections again. However, since it takes a corresponding amount of time to establish the communication connection, there is a problem that when the battery pack becomes operational, the battery pack management device and each battery cell management device cannot start communication promptly.

[0005] Therefore, the inventor has considered maintaining communication between a plurality of monitoring devices that monitor non-monitored devices and a control device communicatively connected to the plurality of monitoring devices even when the monitored devices such as assembled batteries are in a non-operating state as described above. By maintaining communication between the control device and the plurality of monitoring devices when the monitored device is in a non-operating state, when the monitored device becomes operational, the control device and the plurality of monitoring devices can promptly start communication regarding monitoring information of the monitored device and the like.

[0006] However, when the communication connection form during the operating state of the monitored device, in which the control device communicates individually with the plurality of monitoring devices, is maintained as it is even in the non-operating state, a problem occurs in that the power consumption by the control device becomes larger than the power consumption by each monitoring device. When the power supply for supplying power to the control device and the power supply for supplying power to the plurality of monitoring devices are different, the above-described problem becomes a particularly noteworthy point.

[0007] The present disclosure has been made in view of the above points, and an object thereof is to provide a monitoring system capable of suppressing power consumption in a control device while maintaining communication between the control device and a plurality of monitoring devices even in a non-operating state of a non-monitored device.

Means for Solving the Problem

[0008] To achieve the above object, a monitoring system according to the present disclosure includes a plurality of monitoring devices (30) provided in a monitored device and monitoring the monitored device, and a control device (40) that performs wireless communication with the plurality of monitoring devices and acquires monitoring information of the monitored device from the plurality of monitoring devices. The monitored device is a battery pack composed of a plurality of battery stacks, The plurality of monitoring devices respectively monitor the plurality of battery stacks, Battery pack is Perform charge and discharge switchable between an operating state Not requiring charge and discharge and a non-operating state, The control device detects the switching between the operating state and the non-operating state and notifies the plurality of monitoring devices, In the operating state, the control device serves as the communication master unit and performs wireless communication via communication connections individually established with each of a plurality of monitoring devices that are communication slave units. In the non-operating state, When the control device and the plurality of monitoring devices are defined as nodes of wireless communication, in the series relationship such that the plurality of nodes are connected in series to perform wireless communication, a node sandwiched between two nodes becomes a communication master device with respect to one node and a communication slave device with respect to the other node, it is configured such that the communication connection between the control device and the plurality of monitoring devices is maintained.

[0009] As described above, Covered in the non-operating state of the monitoring device, When the control device and the plurality of monitoring devices are defined as nodes of wireless communication, in the series relationship such that the plurality of nodes are connected in series to perform wireless communication, a node sandwiched between two nodes becomes a communication master device with respect to one node and a communication slave device with respect to the other node. In this way, by switching the communication mode between the control device and the plurality of monitoring devices, it becomes possible to suppress the power consumption in the control device while maintaining the communication between the control device and the plurality of monitoring devices.

[0010] The reference numbers in the parentheses above are merely examples of the correspondence with specific configurations in the embodiments described later to facilitate the understanding of the present disclosure, and are not intended to limit the scope of the present disclosure in any way.

[0011] Also, regarding the technical features described in each claim of the claims other than those described above, they will become clear from the description of the embodiments and the accompanying drawings described later.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

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Figure 13

Embodiments for Carrying Out the Invention

[0013] Hereinafter, a plurality of embodiments will be described with reference to the drawings. In each embodiment, the same reference numerals may be assigned to corresponding components, and redundant explanations may be omitted. When only a part of the configuration is described in each embodiment, the configuration of other embodiments described previously can be applied to other parts of the said configuration. Also, not only the combinations of configurations explicitly shown in the description of each embodiment, but also the configurations of a plurality of embodiments can be partially combined with each other as long as there is no problem with the combination, even if not explicitly shown.

[0014] (First Embodiment) First, based on FIG. 1, the configuration of a vehicle equipped with a battery management system as a monitoring system according to this embodiment, particularly a vehicle related to a battery pack equipped with a battery management system, will be described. FIG. 1 is a diagram showing the 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 mobile bodies other than vehicles, such as flying bodies like drones, ships, construction machinery, and agricultural machinery. The battery management system can also be applied to stationary batteries (storage batteries) for household or business use.

[0015] <Vehicle> As shown in FIG. 1, the vehicle 10 includes a battery pack (BAT) 11, a PCU 12, an 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.

[0016] The battery pack 11 includes a battery module 20 described later and provides a DC voltage source that can be charged and discharged. The battery pack 11 supplies power to the 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 may be referred to as the main battery.

[0017] The battery pack 11 is arranged, for example, in the front compartment of the vehicle 10 as shown in FIG. 1. The battery pack 11 may be arranged in the rear compartment, under the seat, or under the floor. For example, in the case of a hybrid vehicle, the compartment where the engine is arranged may be referred to as the engine compartment, engine room, etc.

[0018] The battery pack 11 is temperature-adjusted by the running wind of the vehicle 10 and the cooling wind supplied from a fan mounted on the vehicle 10. The battery pack 11 may be temperature-adjusted by a cooling liquid circulating inside the vehicle 10. By the above-described temperature adjustment, excessive temperature changes of the battery pack 11 are suppressed. Note that the battery pack 11 may simply be connected in a thermally conductive manner to a member having a large heat capacity such as the body of the vehicle 10.

[0019] 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 may be referred to as a power converter. The PCU 12 can include an inverter and a converter. The converter is disposed in the energization path between the battery pack 11 and the inverter. The converter has a function of boosting and bucking a DC voltage. The inverter converts the DC voltage boosted by the converter into an AC voltage, for example, a three-phase AC voltage, and outputs it to the MG 13. The inverter converts the generated power of the MG 13 into a DC voltage and outputs it to the converter. The converter charges the battery cells 20 of the battery pack 11 with a DC voltage obtained by stepping down the DC voltage output from the inverter.

[0020] The MG 13 is an AC rotating electric machine, for example, a three-phase AC synchronous motor in which permanent magnets are embedded in a rotor. The MG 13 functions as a driving source for running 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 drive wheels. The MG 13 functions as a generator during braking of the vehicle 10 and performs regenerative power generation. The generated power of the MG 13 is supplied to the battery pack 11 through the PCU 12 and stored in the battery cells 20 in the battery pack 11.

[0021] ECU14 is configured to include a computer having a processor, a memory, an input / output interface, a bus connecting these components, etc. 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-transitory physical storage medium that non-temporarily stores programs and data readable by the computer. The memory stores various programs executed by the processor.

[0022] ECU14, for example, acquires information about the battery pack 20 from the battery pack 11 and controls the driving of MG13 and the charging and discharging of the battery pack 11 by controlling the PCU12. ECU14 may acquire information such as the voltage, temperature, current, SOC, and SOH of the battery pack 20 from the battery pack 11. ECU14 may acquire battery information such as the voltage, temperature, and current of the battery pack 20 and calculate the SOC and SOH. SOC is an abbreviation for State Of Charge. SOH is an abbreviation for State Of Health.

[0023] The processor of ECU14 executes, for example, a plurality of instructions included in the PCU control program stored in the memory. Thereby, ECU14 constructs a plurality of functional units for controlling the PCU12. In this way, in ECU14, the program stored in the memory causes the processor to execute a plurality of instructions, thereby constructing a plurality of functional units. ECU14 may be referred to as an EVECU.

[0024] <Battery Pack> Next, based on FIGS. 2 and 3, an example of the configuration of the battery pack 11 will be described. FIG. 2 is a perspective view schematically showing the inside of the battery pack 11. In FIG. 2, the housing is shown by a two-dot chain line. FIG. 3 is a plan view showing the upper surface of each battery stack.

[0025] As shown in FIG. 2, the battery pack 11 includes a battery assembly 20, a plurality of monitoring devices 30, a control device 40, and a housing 50. Hereinafter, as shown in FIG. 2, among the respective surfaces of the housing 50 which is substantially a rectangular parallelepiped, in the mounting surface on the vehicle 10, the longitudinal direction is indicated as the X direction, and the short side direction is indicated as the Y direction. In FIG. 2, the lower surface is the mounting surface. And the vertical direction perpendicular to the mounting surface is indicated as the Z direction. The X direction, the Y direction, and the Z direction are in a mutually orthogonal positional relationship. In the present 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 vertical direction corresponds to the Z direction. The arrangements in FIGS. 2 and 3 are merely examples, and the battery pack 11 may be arranged in any manner with respect to the vehicle 10.

[0026] The battery assembly 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 battery blocks, battery modules, etc. The battery assembly 20 is configured by connecting a plurality of battery stacks 21 in series and / or in parallel. In the present embodiment, a plurality of battery stacks 21 are connected in series.

[0027] Each battery stack 21 has a plurality of battery cells 22. The plurality of battery cells 22 are housed in a case (not shown). Thereby, the relative positions of the plurality of battery cells 22 are fixed. The case is made of metal or resin. When the case is made of metal, an electrically insulating member may be partially or entirely interposed between the wall surface of the case and the battery cell 22.

[0028] Note that if the relative positions of the plurality of battery cells 22 can be fixed, the form of the fixing member is not particularly limited. For example, a configuration in which the plurality of battery cells 22 are constrained by a belt - shaped band can also be adopted. In this case, a separator for maintaining the separation distance between the plurality of battery cells 22 may be interposed therebetween.

[0029] The battery stack 21 has a plurality of battery cells 22 connected in series. The battery stack 21 of the present 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 DC voltage source described above. The assembled battery 20, the battery stack 21, and the battery cell 22 correspond to a battery.

[0030] 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 adopted. The lithium-ion secondary battery is a secondary battery that uses lithium as a charge carrier. The secondary batteries that can be adopted for the battery cell 22 may include not only secondary batteries with a liquid electrolyte but also so-called all-solid-state batteries that use a solid electrolyte.

[0031] The battery cell 22 has a power generation element and a battery case that houses this power generation 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, which are two end surfaces arranged in the Z direction and two each arranged in the X direction and two arranged in the Y direction. The battery case of the present embodiment is made of metal.

[0032] Each battery cell 22 is stacked so that the side surfaces of the battery case are in contact with each other in the Y direction. The battery cell 22 has a positive electrode terminal 25 and a negative electrode terminal 26 that protrude in the Z direction, more specifically, in the Z+ direction indicating upward, at both ends in the X direction. The Z-direction positions of the protruding end surfaces of these positive electrode terminal 25 and negative electrode terminal 26 are the same for each battery cell 22. Each battery cell 22 is stacked so that the positive electrode terminal 25 and the negative electrode terminal 26 are alternately arranged in the Y direction.

[0033] On the upper surface of each battery stack 21, linear bus bar units 23 are arranged at both ends in the X direction. The bus bar unit 23 is arranged at both ends in the X direction on the protruding end surfaces of the positive electrode terminals 25 and the negative electrode terminals 26 of a plurality of battery cases. That is, a pair of bus bar units 23 are arranged in each battery stack 21.

[0034] Each bus bar unit 23 has a plurality of bus bars 24 that electrically connect the positive electrode terminals 25 and the negative electrode terminals 26 arranged alternately in the Y direction, and a bus bar cover 27 that covers the plurality of bus bars 24. The bus bar 24 is a plate material made of a metal with good conductivity such as copper or aluminum. The bus bar 24 electrically connects the positive electrode terminal 25 and the negative electrode terminal 26 of the adjacent battery cells 22 in the Y direction. Thereby, in each battery stack 21, a plurality of battery cells 22 are connected in series.

[0035] With such a connection structure, in each battery stack 21, one of the two battery cells 22 located at the ends of the plurality of battery cells 22 arranged in the Y direction becomes the highest potential, and the other becomes 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.

[0036] As shown in FIG. 2, the plurality of battery stacks 21 are arranged side by side in the X direction. The positive electrode terminal 25 of the battery cell 22 with the highest potential in one of the two adjacent battery stacks 21 in the X direction and the negative electrode terminal 26 of the battery cell 22 with the lowest potential in the other are connected via a predetermined wiring. Thereby, the plurality of battery stacks 21 are connected in series.

[0037] With such a connection structure, one of the two battery stacks 21 located at the ends of the plurality of battery stacks 21 arranged 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 plurality of 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 plurality of battery cells 22. These two output terminals are connected to electrical equipment mounted on the vehicle 10 such as the PCU 12.

[0038] Note that two adjacent battery stacks 21 in the X direction do not necessarily need to be electrically connected via a predetermined wiring. Any two of the plurality of battery stacks 21 arranged in the X direction may be electrically connected via a predetermined wiring. Also, the Y-direction positions of the positive electrode terminal 25 and the negative electrode terminal 26 that are electrically connected via a predetermined wiring may be the same or different. That is, these positive electrode terminal 25 and 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 other one may be located in the projection area of one of the positive electrode terminal 25 and the negative electrode terminal 26 in the X direction, or may not be located at all.

[0039] The bus bar cover 27 is formed using an electrically insulating material such as resin. The bus bar cover 27 is linearly provided from end to end of the battery stack 21 along the Y direction so as to cover the plurality of bus bars 24. The bus bar cover 27 may have a partition wall. The partition wall enhances the insulation between two adjacent bus bars 24 in the Y direction.

[0040] The monitoring device 30 is provided individually for the plurality of battery stacks 21. As shown in FIG. 2, the monitoring device 30 is disposed between a pair of bus bar 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 described above in the Z direction. The monitoring device 30 and this end face may be separated in the Z direction, or may be in contact facing each other in the Z direction. An intervening substance such as an insulating sheet may be provided between the monitoring device 30 and this end face.

[0041] The monitoring device 30 is fixed to the bus bar unit 23 with screws or the like. The monitoring device 30 is configured to be capable of wireless communication with the control device 40 as will be described later. An antenna 37 (to be described later) provided in the monitoring device 30 is arranged so as not to overlap with the bus bar unit 23 in the Z direction, that is, so as to protrude more than the bus bar unit 23 in the Z direction.

[0042] In addition, as the material of a connecting member such as a screw for connecting the monitoring device 30 and the bus bar unit 23, for example, a non-magnetic material can be adopted in order to avoid interference with wireless communication. In addition to this screw, in the components provided in the battery stack 21, a non-magnetic material can be adopted as the constituent material of the components that do not particularly need to have magnetism.

[0043] In the present embodiment, a plurality of monitoring devices 30 are arranged side by side in the X direction. And the positions of the plurality of monitoring devices 30 in the Y direction are the same. Due to the configuration shown above, the extension of the separation distance between the plurality of monitoring devices 30 is suppressed.

[0044] 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 capable of wireless communication with each monitoring device 30. An antenna 42 (to be described later) provided in the control device 40 is arranged at approximately the same height as the antenna 37 of the monitoring device 30 in the Z direction. That is, the antenna 42 of the control device 40 is provided so as to protrude more than the bus bar unit 23 in the Z direction.

[0045] In the battery pack 11, the monitoring device 30 and the control device 40 provide a battery management system 60 (to be described later). That is, the battery pack 11 includes the battery management system 60.

[0046] In order to prevent the battery pack 11 from becoming an electromagnetic noise source, it is necessary to suppress the leakage of radio waves of wireless communication to the outside of the space where the wireless communication between the monitoring device 30 and the control device 40 is performed. Conversely, in order to suppress the interference with this wireless communication, it is necessary to suppress the intrusion of electromagnetic noise into the communication space.

[0047] For this reason, the housing 50 has, for example, the performance of reflecting electromagnetic waves. The housing 50 is provided with the materials shown below as an example in order to reflect electromagnetic waves. For example, the housing 50 is provided with a magnetic material such as metal. The housing 50 is provided with a resin material and a magnetic material covering its surface. The housing 50 is provided with a resin material and a magnetic material embedded therein. The housing 50 is provided with carbon fibers. Instead of the performance of reflecting electromagnetic waves, the housing 50 may have the performance of absorbing electromagnetic waves.

[0048] The housing 50 may have a hole communicating with the accommodation space inside and the space outside (external space). The hole is partitioned by a connecting surface between the inner surface and the outer surface of the housing 50. This hole is used for ventilation, taking out power lines, taking out signal lines, etc. In the case of a configuration having a hole, a covering portion may be provided for the hole. The communication between the accommodation space and the external space is blocked by the covering portion. The covering portion may block all of the holes or may block a part of the holes.

[0049] The covering portion is provided, for example, on any of the inner surface, the outer surface, and the connecting surface of the housing 50. The covering portion may be arranged opposite to the hole in a manner of covering the hole without being provided on any of these inner surface, outer surface, and connecting surface. When the covering portion and the hole are separated, the separation distance 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 orthogonal to this distance.

[0050] The covering portion is, for example, a connector, an electromagnetic shielding member, a sealing material, etc. The covering portion is provided with the materials shown below as an example. The covering portion is provided with a magnetic material such as metal, for example. The covering portion is provided with a resin material and a magnetic material covering its surface. The covering portion is provided with a resin material and a magnetic material embedded therein. The covering portion is provided with carbon fibers. The covering portion contains a resin material.

[0051] The holes in the housing 50 may be covered by at least one of the elements accommodated in the accommodation space of the housing 50. The separation distance between the accommodation and the holes is shorter than the length of the holes described above. Also, power lines and signal lines may be arranged across the accommodation space and the external space while being held by an electrical insulating member that forms part of the wall of the housing 50.

[0052] <Battery Management System> Next, based on FIG. 4, the schematic configuration of the battery management system will be described. FIG. 4 is a block diagram showing the configuration of the battery management system.

[0053] 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 device may be referred to as SBM. 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 a battery using wireless communication. In this wireless communication, a frequency band used for short-range communication, for example, the 2.4 GHz band or the 5 GHz band, is used.

[0054] The battery management system 60 employs one-to-one communication or network communication according to the number of nodes of wireless communication by the monitoring device 30 and / or the control device 40. The number of nodes can change depending on the standby 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 wireless communication is performed between all of a master and slaves, with one node as the master and the remaining nodes as slaves. Another form of network communication is chain communication in which a plurality of nodes are connected in series and wireless communication is performed.

[0055] The battery management system 60 further includes a sensor 70. The sensor 70 includes a physical quantity detection sensor that detects the physical quantity of each battery cell 22, a discrimination sensor, and the like. The physical quantity detection sensor includes, for example, a voltage sensor, a temperature sensor, a current sensor, and the like.

[0056] The voltage sensor includes a detection wiring connected to the bus bar 24. The voltage sensor detects the voltage (cell voltage) of each of the plurality of battery cells 22. The discrimination sensor discriminates whether the correct battery is attached or not.

[0057] The temperature sensor is selectively provided in a part of the plurality of 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 the battery cell 22 that is assumed to have the highest temperature, the battery cell 22 that is assumed to have the lowest temperature, the battery cell 22 that is assumed to have an intermediate temperature, etc. among the plurality of battery cells 22 included in one battery stack 21. The number of temperature sensors for one battery stack 21 is not particularly limited.

[0058] The current sensor is provided in a plurality of battery stacks 21. The current sensor detects the current (cell current) that commonly flows through each of the plurality of battery cells 22 connected in series and each of the plurality of battery stacks 21 connected in series. In the present 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.

[0059] <Monitoring device> First, the monitoring device 30 will be described. The configurations of the respective monitoring devices 30 are common to each other. 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). Communication between the respective elements in the monitoring device 30 is performed by wire.

[0060] The power supply circuit 31 generates the operating power supply for other circuit elements included in the monitoring device 30 by using the voltage supplied from the battery stack 21. In the present embodiment, the power supply circuit 31 includes power supply circuits 311, 312, and 313. The power supply circuit 311 generates a predetermined voltage by using the voltage supplied from the battery stack 21 and supplies it to the monitoring IC 33. The power supply circuit 312 generates a predetermined voltage by using the voltage generated by the power supply circuit 311 and supplies it to the microcomputer 34. The power supply circuit 313 generates a predetermined voltage by using the voltage generated by the power supply circuit 311 and supplies it to the wireless IC 35.

[0061] The multiplexer 32 is a selection circuit that selects one of the detection signals of at least a part of the plurality of sensors 70 included in the battery pack 11 and outputs the selected signal. The multiplexer 32 selects (switches) the input according to the selection signal from the monitoring IC 33 and outputs it as one signal.

[0062] The monitoring IC 33 senses (acquires) battery information such as cell voltage and cell temperature and transmits it to the microcomputer 34. For example, the monitoring IC 33 directly acquires the cell voltage from the voltage sensor and acquires information such as the cell temperature through the multiplexer. The monitoring IC 33 acquires the cell voltage while associating which battery cell 22 the value is. That is, the cell voltage is acquired while discriminating the cell. 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 by wire.

[0063] The monitoring IC 33 is sometimes referred to as a cell supervising circuit (CSC). CSC is an abbreviation for Cell Supervising Circuit. The monitoring IC 33 performs a failure 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 failure diagnosis information to the microcomputer 34. The monitoring device 30 may store (save) 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 and transmits the battery monitoring information including the battery information to the microcomputer 34. In addition to the above-described example, the battery monitoring information may include information such as the exhaust temperature, impedance, state of equalization of the cell voltage, stack voltage, state of synchronization with the control device 40, and presence or absence of abnormality in the detection wiring.

[0064] The microcomputer 34 is a microcomputer including a CPU which is a processor, a ROM and a RAM which are memories, an input / output interface, and a bus connecting these. The CPU constructs a plurality of functional units by executing various programs stored in the ROM while using the temporary storage function of the RAM. ROM is an abbreviation for Read Only Memory. RAM is an abbreviation for Random Access Memory.

[0065] The microcomputer 34 controls the schedule of sensing and self-diagnosis by the monitoring IC 33. The microcomputer 34 receives the 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, it may transmit data requesting acquisition of the battery monitoring information to the monitoring IC 33. The microcomputer 34 may autonomously request acquisition of the battery monitoring information from the monitoring IC 33. For example, the microcomputer 34 may periodically request acquisition of the battery monitoring information from the monitoring IC 33.

[0066] The wireless IC 35 includes an RF circuit (not shown) and a microcomputer for wirelessly transmitting and receiving data. The microcomputer includes a memory. The wireless IC 35 has a transmitter function of modulating transmission data and oscillating at the frequency of the RF signal. The wireless IC 35 has a receiver function of demodulating received data. RF is an abbreviation for radio frequency.

[0067] 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 then transmits it. The data necessary for wireless communication includes, for example, an identifier (ID), an error detection code, and the like. The wireless IC 35 controls the data size, communication format, schedule, error detection, etc. of the wireless communication between other nodes.

[0068] The wireless IC 35 receives the data transmitted from other nodes via the antenna 37 and the front-end circuit 36 and demodulates it. When the wireless IC 35 receives data including, for example, a transmission request for battery monitoring information, it transmits data including the battery monitoring information to other nodes as a response to the request. In addition to the above-described battery monitoring information, the monitoring device 30 may transmit battery traceability information and / or manufacturing history information to other nodes. The battery traceability information is, for example, the number of charge / discharge cycles, the number of failures, the total charge / discharge time, and the like. The manufacturing history information is, for example, the manufacturing date, place, manufacturer, serial number, manufacturing number, and the like. The manufacturing history information is stored in the memory provided in the monitoring device 30. The monitoring device 30 may transmit battery traceability information and / or manufacturing history information to other nodes instead of the above-described battery monitoring information.

[0069] The front-end circuit 36 has a matching circuit for impedance matching between the wireless IC 35 and the antenna 37, and a filter circuit for removing unnecessary frequency components.

[0070] Antenna 37 converts an electrical signal into a radio wave and radiates it into space. Antenna 37 receives a radio wave propagating in space and converts it into an electrical signal.

[0071] <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 within the control device 40 is performed by wire.

[0072] The power supply circuit 41 generates an operating power supply for other circuit elements included in the control device 40 using the voltage supplied from the battery (BAT) 15. The battery 15 is a DC voltage source separate from the battery pack 11 mounted on the vehicle 10. The battery 15 may be referred to as an accessory battery because it supplies power to the accessories of the vehicle 10. In the present 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. For the sake of simplifying the drawing, the 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.

[0073] Antenna 42 converts an electrical signal into a radio wave and radiates it into space. Antenna 42 receives a radio wave propagating in space and converts it into an electrical signal.

[0074] 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.

[0075] The wireless IC 44 includes an RF circuit and a microcomputer (not shown) for wirelessly transmitting and receiving data. Similar to the wireless IC 35, the wireless IC 44 has a transmitter function and a receiver function. The wireless IC 44 receives the data transmitted from the monitoring device 30 via the antenna 42 and the front-end circuit 43 and demodulates it. Then, it transmits the data including the battery monitoring information to the main microcomputer 45. The wireless IC 44 receives the data transmitted from the main microcomputer 45, modulates it, and transmits it to the monitoring device 30 via the front-end circuit 43 and the antenna 42. The wireless IC 44 attaches data necessary for wireless communication, such as communication control information, to the transmitted data and then transmits it. 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, etc. of the wireless communication with other nodes.

[0076] The main microcomputer 45 is a microcomputer equipped with a CPU, a ROM, a RAM, an input / output interface, and a bus connecting these components. The ROM stores various programs executed by the CPU. The main microcomputer 45 generates a command for requesting a predetermined process from the monitoring device 30 and transmits the transmitted data including the command to the wireless IC 44. The main microcomputer 45 generates, for example, a command for requesting the transmission of battery monitoring information. The main microcomputer 45 may generate a command for requesting the acquisition of battery monitoring information and, at the same time, requesting the transmission of battery monitoring information. The requests described in this specification may be referred to as instructions.

[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 the present embodiment, the main microcomputer 45 acquires the cell current from the 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 based on, for example, the cell voltage and the cell current. The open circuit voltage is the cell voltage corresponding 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 in the voltage drop corresponding to the internal resistance and the cell current between the open circuit voltage and the cell voltage acquired by the monitoring device 30. 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 in consideration of, for example, the cell temperature as well.

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

[0080] The sub-microcomputer 46 is a microcomputer equipped with a CPU, ROM, RAM, input / output interfaces, and a bus for connecting these components. The ROM stores various programs executed by the CPU. The sub-microcomputer 46 executes monitoring processes 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 state of the main microcomputer 45. The sub-microcomputer 46 may monitor the state of the wireless IC 44.

[0081] <Communication in the operating state> In the operating state of the battery pack 20 of the battery management system 60 of this embodiment, star-type network communication is performed for power supply to in-vehicle systems such as MG13 from the battery pack 20 via a system main relay (SMR) not shown in the figure. That is, the control device 40 performs wireless communication with each of the plurality of monitoring devices 30 via individually established communication connections. Hereinafter, for convenience, the wireless communication between one monitoring device 30 and the control device 40 will be described, but the control device 40 executes the same processing with all the monitoring devices 30.

[0082] First, based on FIGS. 5 and 6, the connection process for establishing an individual communication connection between the monitoring device 30 and the control device 40 will be described. FIG. 5 is a diagram showing the communication sequence between the monitoring device 30 and the control device 40. The communication sequence may be referred to as a communication flow. FIG. 6 shows an example of the connection process. In FIGS. 5 and 6, the control device 40 is shown as ECU40.

[0083] As shown in FIG. 5, a connection process (S10) is performed between the control device 40 and each monitoring device 30 in order to individually establish a communication connection in which the control device 40 serves as the communication master device and each monitoring device 30 serves as the communication slave device. When the control device 40 and each monitoring device 30 communicate according to the BLE communication protocol, this connection process (S10) includes a connection establishment process (S11) and a pairing process (S12), as shown in FIG. 6. Note that BLE is an abbreviation for Bluetooth Low Energy. Bluetooth is a registered trademark. However, the communication between the control device 40 and each monitoring device 30 may be performed according to a communication protocol other than the BLE communication protocol.

[0084] In the connection establishment process (S11), the control device 40 executes a scan operation (S111), and the monitoring device 30 executes an advertisement operation (S112). The start of the scan operation may be earlier than the start of the advertisement operation, may be at approximately the same timing, or may be later than the start of the advertisement operation.

[0085] The wireless IC 35 of the monitoring device 30 executes an advertisement operation and transmits an advertisement packet (ADV_PKT) to the wireless IC 44 of the control device 40 in order to inform the control device 40 of its own existence. The advertisement packet includes ID information of itself (monitoring device 30) and the control device 40.

[0086] When the control device 40 detects an advertisement packet, that is, the monitoring device 30, by the scan operation, it transmits a connection request (CONNECT_REQ) to the detected monitoring device 30 (S113).

[0087] When the monitoring device 30 receives the connection request, a connection is established between one monitoring device 30 and the control device 40. When the connection is established, the monitoring device 30 stops transmitting the advertisement packet. The monitoring device 30 periodically transmits the advertisement packet until the connection is established.

[0088] When the connection establishment process ends, the pairing process (S12) is then executed. The pairing process is a process for performing encrypted data communication. The pairing process includes an exchange process of unique information (S121). In this exchange process, the unique information (for example, an encryption key or information for generating an encryption key) held by each party is exchanged and stored in each memory. After the execution of the process in step S121, encryption using the exchanged unique information becomes possible.

[0089] Although an example in which the control device 40 executes a scanning operation and the monitoring device 30 executes an advertising operation has been shown, the present invention is not limited to this. A configuration in which the monitoring device 30 executes a scanning operation and the control device 40 executes an advertising operation may also be used.

[0090] Next, based on FIGS. 5 and 7, the periodic communication process performed between the monitoring device 30 and the control device 40 in the operating state of the assembled battery 20 will be described. FIG. 7 shows an example of the periodic communication process. In FIG. 7, the monitoring IC 33 is shown as MIC 33, the wireless IC 35 is shown as WIC 35, and the control device 40 is shown as ECU 40.

[0091] When the above-described connection process is completed, the monitoring device 30 and the control device 40 execute a periodic communication process (S20). In this periodic communication process, the control device 40 and the monitoring device 30 perform data communication periodically (at regular intervals). In the data communication, for example, as shown in FIG. 7, the control device 40 transmits request data to the monitoring device 30 for which the connection process has been completed (S21). As an example, the control device 40 transmits request data including a request for acquiring battery monitoring information and a transmission request.

[0092] When the wireless IC 35 of the monitoring device 30 receives the request data, it transmits a request for acquiring battery monitoring information, that is, an acquisition instruction, to the monitoring IC 33 (S22). The wireless IC 35 of the present embodiment transmits the acquisition request to the monitoring IC 33 via the microcomputer 34.

[0093] When the monitoring IC 33 receives an acquisition request, it performs sensing (S23). The monitoring IC 33 performs sensing to acquire battery information of each battery cell 22. Also, the monitoring IC 33 performs a failure diagnosis of the circuit.

[0094] Next, the monitoring IC 33 transmits the acquired battery monitoring information to the wireless IC 35 (S24). In the present embodiment, the battery monitoring information including the failure diagnosis result together with the battery information is transmitted. The monitoring IC 33 transmits the battery monitoring information to the wireless IC 35 via the microcomputer 34.

[0095] When the wireless IC 35 receives the battery monitoring information from the monitoring IC 33, it transmits transmission data including the battery monitoring information, that is, response data, to the control device 40 (S25). The control device 40 receives the response data (S26). The control device 40 periodically performs the above-described data communication with the connected monitoring device 30.

[0096] Based on the received response data, that is, the battery monitoring information, the control device 40 performs a predetermined process, that is, as described above, a process of transmitting the acquired battery monitoring information to the ECU 14, a process of instructing the execution of an equalization process for equalizing the voltages of the respective battery cells 22, a process of detecting an abnormality in the battery cell 22 or the circuit, etc. (S30).

[0097] Although an example in which the monitoring device 30 acquires the battery monitoring information based on the acquisition request from the control device 40 has been shown, the present invention is not limited thereto. The monitoring device 30 may autonomously acquire the battery monitoring information and transmit the held battery monitoring information to the control device 40 based on a transmission request from the control device 40. According to this, the processes of steps S22 to S24 in response to the acquisition request become unnecessary.

[0098] <Communication in the non-operating state> The battery management system 60 according to this embodiment maintains communication between the control device 40 and the plurality of monitoring devices 30 even when the assembled battery 20 is in a non-operating state so that, for example, when switching from the non-operating state of the assembled battery 20, in which the SMR is turned off as the ignition switch is turned off and power supply to in-vehicle systems such as the MG13 from the assembled battery 20 via the SMR is not required, to the operating state, the control device 40 and the plurality of monitoring devices 30 can promptly start communication. However, as shown in FIG. 8(a), if the communication mode during the operating state of the assembled battery 20, in which the control device 40 serves as the communication master device and individually communicates with the plurality of monitoring devices 30 which are communication slave devices (that is, a star network), is maintained as it is even in the non-operating state, the power consumption by the control device 40 will become larger than the power consumption by each of the monitoring devices 30. The main reason for this is that the control device 40 needs to communicate with the plurality of monitoring devices 30, and the communication master device function for performing communication schedule management and the like generally has a higher load than the communication slave device function. Note that power is supplied to devices such as the monitoring device 30 directly connected to the assembled battery 20 without passing through the SMR even when the assembled battery 20 is in the non-operating state.

[0099] Therefore, the battery management system 60 according to this embodiment switches to a communication mode different from that during the operating state when the assembled battery 20 is in the non-operating state, and while suppressing the power consumption of the control device 40, maintains communication between the control device 40 and the plurality of monitoring devices 30. Hereinafter, the communication mode between the control device 40 and the plurality of monitoring devices 30 in the non-operating state of the assembled battery 20 will be described in detail.

[0100] Fig. 8(b) is a diagram showing an example of a communication network in the non-operating state of the assembled battery 20. As shown in Fig. 8(b), in the non-operating state of the assembled battery 20, the control device 40 serves as a communication master device for one of the plurality of monitoring devices 30_1, 30_2, 30_3, i.e., the monitoring device 30_1. And one of the plurality of monitoring devices 30_1, 30_2, 30_3 sequentially assumes the role of the communication master device for another one of the monitoring devices 30_1, 30_2, 30_3. That is, in the non-operating state of the assembled battery 20, the communication form between the control device 40 and the plurality of monitoring devices 30_1, 30_2, 30_3 becomes a chain-type network. By adopting such a communication form in the non-operating state of the assembled battery 20, the power consumption of each device 40, 30_1, 30_2, 30_3 can be equalized.

[0101] In addition, in the example shown in Fig. 8(b), in addition to serving as the communication master device of the monitoring device 30_1, the control device 40 also serves as a communication slave device of the monitoring device 30_3. However, one of the communication paths between the control device 40 and the monitoring device 30_1 or the communication paths between the monitoring devices 30_1, 30_2, 30_3 does not have to be formed. This is because even if one communication path is not formed, the control device 40 and all the monitoring devices 30_1, 30_2, 30_3 can participate in the communication network. Also, in Fig. 8(b), the number of monitoring devices 30 is three, but the number of monitoring devices 30 is not limited to this, and it may be two or four or more. When the number of monitoring devices 30 is large, a plurality of communication networks shown in Fig. 8(b) may be formed. In that case, the control device 40 may serve as the communication master device for two or more monitoring devices 30.

[0102] Next, with reference to the flowchart of Fig. 9, the processing in the control device 40 and each monitoring device 30_1, 30_2, 30_3 for changing the communication network when the assembled battery 20 switches from the operating state to the non-operating state and when it switches from the non-operating state to the operating state will be described.

[0103] The control device 40 detects that the ignition switch has been turned off at step S40 as a trigger indicating the switching of the assembled battery 20 from the operating state to the non-operating state. However, the switching of the assembled battery 20 from the operating state to the non-operating state may be detected using as a trigger the fact that the vehicle has stopped, the driver has gotten out of the vehicle, each door of the vehicle has been locked, etc. When the control device 40 detects that the ignition switch has been turned off, it notifies each monitoring device 30_1, 30_2, 30_3 that the ignition switch has been turned off. As a result, each monitoring device 30_1, 30_2, 30_3 can grasp that it is necessary to change the form of the communication network to a chain-type network for the non-operating state of the assembled battery 20.

[0104] The control device 40 and each monitoring device 30_1, 30_2, 30_3 serve as both a communication master device and a communication slave device for other devices 40, 30_1, 30_2, 30_3, and thus execute a connection acceptance operation (scanning operation) and a connection request operation (advertising operation). More specifically, each of the control device 40 and the monitoring devices 30_1, 30_2, 30_3 executes the connection acceptance operation and the connection request operation at different timings as shown in the flowchart of FIG. 9. Note that the combination of the devices 40, 30-1, 30_2, 30_3 that serve as the communication master device and the devices 40, 30_1, 30_2, 30_3 that serve as the communication slave device can be set in advance. However, the combination is determined by the control device 40 or any one of the monitoring devices 30-1, 30_2, 30_3 when it is detected that the ignition switch has been turned off, and may be notified to the other devices 40, 30-1, 30_2, 30_3.

[0105] For example, in the example shown in the flowchart of FIG. 9, the monitoring device 30_1 performs a connection acceptance operation in step S41 to become the communication master device of the monitoring device 30_2, and the monitoring device 30_2 performs a connection request operation in step S42 to become the communication slave device of the monitoring device 30_1. Further, the monitoring device 30_3 performs a connection acceptance operation in step S43 to become the communication master device of the control device 40, and the control device 40 performs a connection request operation in step S44 to become the communication slave device of the monitoring device 30_3. Then, in step S45, the connection establishment operations between the monitoring device 30_1 and the monitoring device 30_2, and between the monitoring device 30_3 and the control device 40 are executed, that is, the communication master device detects the advertisement packet of the communication slave device, sends a connection request (CONNECT_REQ) to the communication slave device, and further, the communication master device and the communication slave device exchange unique information.

[0106] Note that in the star-type network for the operating state of the assembled battery 20, a communication connection is established between the control device 40 as the communication master device and the monitoring device 30_3 as the communication slave device. If it is easier and faster to complete the process by switching the roles of the communication master device and the communication slave device using the established communication connection than to establish a new communication connection using the scan operation and the advertisement operation, the connection acceptance operation in step S43 and the connection request operation in step S44 may be replaced with the process of switching the roles of the communication master device and the communication slave device.

[0107] Also, in the example shown in the flowchart of FIG. 9, after the completion of the connection establishment operation in step S45, the control device 40 performs a connection acceptance operation in step S46 to become the communication master device of the monitoring device 30_1, and the monitoring device 30_1 performs a connection request operation in step S47 to become the communication slave device of the control device 40. Further, the monitoring device 30_2 performs a connection acceptance operation in step S48 to become the communication master device of the monitoring device 30_3, and the monitoring device 30_3 performs a connection request operation in step S49 to become the communication slave device of the monitoring device 30_2. Then, in step S50, the connection establishment operations between the control device 40 and the monitoring device 30_1, and between the monitoring device 30_2 and the monitoring device 30_3 are executed.

[0108] In the star network for the operating state of the assembled battery 20, a communication connection is established between the control device 40 as the communication master unit and the monitoring device 30_1 as the communication slave unit. As the communication connection between the control device 40 and the monitoring device 30_1, this established communication connection can be directly utilized. Therefore, the connection acceptance operation in step S46 and the connection request operation in step S47 may be omitted.

[0109] In the flowchart of FIG. 9, an example is shown in which the connection establishment operations between the monitoring device 30_1 and the monitoring device 30_2, and between the monitoring device 30_3 and the control device 40 are executed first, and then the connection establishment operations between the control device 40 and the monitoring device 30_1, and between the monitoring device 30_2 and the monitoring device 30_3 are executed. However, in reality, the control device 40 and the plurality of monitoring devices 30_1, 30_2, 30_3 each repeatedly perform the connection acceptance operation and the connection request operation periodically. And the connection establishment operation is performed from the pair in which the advertisement packet and the corresponding connection request are transmitted and received between the communication slave unit and the communication master unit that should be paired. When the control device 40 and each of the monitoring devices 30_1, 30_2, 30_3 have previously performed the connection establishment operation as the communication master unit, thereafter, the connection acceptance operation is stopped, and only the connection request operation is continued until the connection establishment operation as the communication slave unit is completed. On the other hand, when the control device 40 and each of the monitoring devices 30_1, 30_2, 30_3 have previously performed the connection establishment operation as the communication slave unit, thereafter, the connection request operation is stopped, and only the connection acceptance operation is continued until the connection establishment operation as the communication master unit is completed.

[0110] In the operating state of the assembled battery 20, the communication connection with the control device 40 as the communication master unit and the monitoring devices 30_2, 30_3 as the communication slave units is disconnected at the latest by the time the periodic communication starts after it is detected that the ignition switch has been turned off and this is transmitted to each of the monitoring devices 30_2, 30_3.

[0111] Through the processes in the control device 40 and each monitoring device 30_1, 30_2, 30_3 described above, a chain-type network shown in FIG. 8(b) is formed. In step S51 of the flowchart in FIG. 9, in the formed chain-type network, periodic communication is performed between the communication master device and the communication slave devices. However, in this periodic communication, since the assembled battery 20 is in a non-operating state, the above-described battery monitoring information does not necessarily need to be transmitted. The periodic communication is mainly executed to maintain the formed chain-type network.

[0112] In step S52, the control device 40 detects that the ignition switch has been turned on as a trigger indicating the switching of the assembled battery 20 from the non-operating state to the operating state. Alternatively, the trigger indicating the switching of the assembled battery 20 from the non-operating state to the operating state may be detected by the fact that a user holding the smart key approaches the vehicle, the lock of the vehicle door is released, the driver sits on the driver's seat, or the like. When the control device 40 detects that the ignition switch has been turned on, it notifies each of the monitoring devices 30_1, 30_2, 30_3 via the chain-type network that the ignition switch has been turned on. Thereby, each of the monitoring devices 30_1, 30_2, 30_3 can recognize that it is necessary to change the form of the communication network to a star-type network for the operating state of the assembled battery 20.

[0113] Since the control device 40 serves as the communication master device for each of the monitoring devices 30_1, 30_2, 30_3 and each of the monitoring devices 30_1, 30_2, 30_3 serves as the communication slave device of the control device 40, the control device 40 and each of the monitoring devices 30_1, 30_2, 30_3 execute a connection acceptance operation (scanning operation) and a connection request operation (advertising operation). More specifically, the control device 40 performs the connection acceptance operation in step S53, and the monitoring devices 30_2, 30_3 perform the connection request operation in steps S54 and S55. Then, in step S56, a connection establishment operation between the control device 40 and each of the monitoring devices 30_1, 30_2, 30_3 is executed.

[0114] Since the monitoring device 30_1 has already established a communication connection with the control device 40 as the communication master device, it does not perform the connection request operation again. In this way, when the control device 40 maintains the communication connection with the monitoring device 30_1, which is the communication master device, in the non-operating state of the battery pack 20, the star-shaped network for the operating state of the battery pack 20 can be formed earlier, and communication with each of the monitoring devices 30_1, 30_2, and 30_3 can be started.

[0115] Also, in the chain-type network for the non-operating state of the battery pack 20, a communication connection is established between the control device 40 as the communication slave device and the monitoring device 30_3 as the communication master device. If it is easier and faster to complete the process by switching the roles of the communication master device and the communication slave device using the established communication connection than to establish a new communication connection using the scan operation and the advertise operation, with respect to the control device 40 and the monitoring device 30_3, instead of the normal connection acceptance operation and connection request operation, a process of switching the roles of the communication master device and the communication slave device may be executed.

[0116] The communication connection between the control device 40 forming the chain-type network and each of the monitoring devices 30_1, 30_2, and 30_3 in the non-operating state of the battery pack 20 is disconnected at the latest by the time regular communication starts after it is detected that the ignition switch is turned on and notified to each of the monitoring devices 30_1, 30_2, and 30_3.

[0117] (Second Embodiment) Next, the battery management system 60 according to the second embodiment will be described with reference to the drawings. The battery management system 60 according to the present embodiment is configured in the same manner as the battery management system 60 according to the first embodiment. Therefore, the description of the configuration of the battery management system 60 according to the present embodiment will be omitted.

[0118] The battery management system 60 according to this embodiment, similar to the first embodiment, when the assembled battery 20 is in a non-operating state, switches to a communication mode different from that in the operating state, suppresses the power consumption of the control device 40, and maintains the communication between the control device 40 and the plurality of monitoring devices 30. However, the battery management system 60 according to this embodiment, different from the first embodiment, divides a plurality of pairs of a communication master device and a communication slave device set between the control device 40 and the plurality of monitoring devices 30_1, 30_2, 30_3 into a plurality of groups. And the divided plurality of groups perform periodic communication in order in a time-division manner. That is, the groups performing communication alternate periodically. FIG. 10 shows a state where the control device 40 and the monitoring device 30_3, and the monitoring device 30_1 and the monitoring device 30_2 belong to one group and perform communication. In this way, a plurality of pairs of a communication master device and a communication slave device can belong to one group.

[0119] By doing so, the frequency at which the control device 40 and each of the monitoring devices 30_1, 30_2, 30_3 perform communication can be reduced, and the power consumption of each of the devices 40, 30_1, 30_2, 30_3 can be further reduced.

[0120] Next, with reference to the flowchart of FIG. 11, the processing of the control device 40 and each of the monitoring devices 30_1, 30_2, 30_3 in this embodiment will be described.

[0121] The processing of steps S60 to S64 in the flowchart of FIG. 11 is the same as the processing of steps S40 to S44 in the flowchart of FIG. 9. And in step S65, a connection establishment operation between the monitoring device 30_1 and the monitoring device 30_2, and between the monitoring device 30_3 and the control device 40 is executed. Note that a pair in which the monitoring device 30_1 is the communication master device and the monitoring device 30_2 is the communication slave device, and a pair in which the monitoring device 30_3 is the communication master device and the control device 40 is the communication slave device are defined as group A.

[0122] The processes of steps S66 to S69 in the flowchart of FIG. 11 are the same as the processes of steps S46 to S49 in the flowchart of FIG. 9. Then, in step S70, a connection establishment operation between the control device 40 and the monitoring device 30_1, and between the monitoring device 30_2 and the monitoring device 30_3 is executed. Note that a pair in which the control device 40 is the communication master device and the monitoring device 30_1 is the communication slave device, and a pair in which the monitoring device 30_2 is the communication master device and the monitoring device 30_3 is the communication slave device are defined as group B.

[0123] In the flowchart of FIG. 11, for convenience, a pair in which the monitoring device 30_1 belonging to group A is the communication master device and the monitoring device 30_2 is the communication slave device, and a pair in which the monitoring device 30_3 is the communication master device and the control device 40 is the communication slave device perform the connection establishment operation first, and then, a pair in which the control device 40 belonging to group B is the communication master device and the monitoring device 30_1 is the communication slave device, and a pair in which the monitoring device 30_2 is the communication master device and the monitoring device 30_3 is the communication slave device perform the connection establishment operation. However, as described in the first embodiment, actually, the control device 40 and the plurality of monitoring devices 30_1, 30_2, 30_3 each repeatedly perform a connection reception operation and a connection request operation periodically. Then, a connection establishment operation is performed from a pair in which an advertisement packet and a connection request in response thereto are transmitted and received between the communication slave device and the communication master device to be paired. When all the connection establishment operations are completed, the pairs belonging to group A communicate synchronously, and the pairs belonging to group B communicate synchronously at a timing different from that of group A. That is, in the periodic communication in step S71, communication by the pair of the communication master device and the communication slave device belonging to group A and communication by the pair of the communication master device and the communication slave device belonging to group B are performed alternately.

[0124] Whether to group the pairs of the above-described communication master unit and communication slave units into any group may be set in advance. Further, one of the control device 40 or the monitoring devices 30_1, 30_2, 30_3 may perform grouping according to the charge amount of the battery stack 21 monitored by each of the monitoring devices 30_1, 30_2, 30_3. When grouping the monitoring devices 30_1, 30_2, 30_3 according to the charge amount of the battery stack 21, it is preferable to group the pairs in which the monitoring device 30 monitoring the battery stack 21 showing a relatively high charge amount becomes the communication master unit into the same group, and group the pairs in which the monitoring device 30 monitoring the battery stack 21 showing a relatively low charge amount becomes the communication master unit into the same group. Furthermore, one of the control device 40 or the monitoring devices 30_1, 30_2, 30_3 preferably manages the periodic alternation of the communication groups so that, in periodic communication, the opportunity for the group to which the pair in which the monitoring device 30 monitoring the battery stack 21 showing a relatively high charge amount becomes the communication master unit belongs to communicate is increased compared to the opportunity for the group to which the pair in which the monitoring device 30 monitoring the battery stack 21 showing a relatively low charge amount becomes the communication master unit belongs to communicate.

[0125] When it becomes a communication master unit, compared with the case of being a communication slave unit, more power will be consumed by the communication process with the communication partner. By increasing the communication opportunity as the communication master unit, it is possible to equalize the charge amounts of the respective battery stacks 21.

[0126] In order to increase the communication opportunity of the group to which the pair in which the monitoring device 30 monitoring the battery stack 21 showing a relatively high charge amount becomes the communication master unit belongs, one of the control device 40 or the monitoring devices 30_1, 30_2, 30_3, for example, makes the communication period of the group to which the pair in which the monitoring device 30 monitoring the battery stack 21 showing a relatively high charge amount becomes the communication master unit belongs longer than the communication period of the group to which the pair in which the monitoring device 30 monitoring the battery stack 21 showing a relatively low charge amount becomes the communication master unit belongs, and manages the periodic alternation of the communication groups.

[0127] Alternatively, the control device 40 or one of the monitoring devices 30_1, 30_2, 30_3, for example, the monitoring device 30 that monitors the battery stack 21 indicating a relatively high charge amount, may manage periodic alternation of the groups that perform communication so that the selection frequency of the group to which the pair having the communication master device belongs is higher than the selection frequency of the group to which the pair having the monitoring device 30 that monitors the battery stack 21 indicating a relatively low charge amount and serves as the communication master device belongs. Specifically, the number of times the group to which the pair having the monitoring device 30 that monitors the battery stack 21 indicating a relatively high charge amount and serves as the communication master device belongs is selected may be made more than the number of times the group to which the pair having the monitoring device 30 that monitors the battery stack 21 indicating a relatively low charge amount and serves as the communication master device belongs is selected, to manage periodic alternation of the groups that perform communication.

[0128] (Third Embodiment) Next, the battery management system 60 according to the third embodiment will be described with reference to the drawings. The battery management system 60 according to the present embodiment is configured in the same manner as the battery management system 60 according to the first embodiment. Therefore, the description of the configuration of the battery management system 60 according to the present embodiment is omitted.

[0129] Similar to the second embodiment, the battery management system 60 according to the present embodiment divides a plurality of pairs of a communication master device and a communication slave device set among the control device 40 and the plurality of monitoring devices 30_1, 30_2, 30_3 into a plurality of groups. Then, the plurality of divided groups perform periodic communication in order in a time-division manner. And in the present embodiment, as shown in FIG. 12, the number of pairs of the communication master device and the communication slave device belonging to each group that performs communication is made smaller than that in the second embodiment. Thereby, the power consumed by the control device 40 and each of the monitoring devices 30_1, 30_2, 30_3 due to communication can be further reduced.

[0130] Next, with reference to the flowchart of FIG. 13, the processing of the control device 40 and each of the monitoring devices 30_1, 30_2, 30_3 in the present embodiment will be described.

[0131] The process of step S80 in the flowchart of FIG. 13 is the same as the process of step S40 in the flowchart of FIG. 9. In step S81, the monitoring device 30_1 performs a connection acceptance operation to become the communication master device of the monitoring device 30_2. In step S82, the monitoring device 30_2 performs a connection request operation to become the communication slave device of the monitoring device 30_1. Then, in step S83, a connection establishment operation between the monitoring device 30_1 and the monitoring device 30_2 is executed. At this time, a pair in which the monitoring device 30_1 is the communication master device and the monitoring device 30_2 is the communication slave device is defined as group C.

[0132] In step S84, the monitoring device 30_2 performs a connection acceptance operation to become the communication master device of the monitoring device 30_3. In step S85, the monitoring device 30_3 performs a connection request operation to become the communication slave device of the monitoring device 30_2. Then, in step S86, a connection establishment operation between the monitoring device 30_2 and the monitoring device 30_3 is executed. At this time, a pair in which the monitoring device 30_2 is the communication master device and the monitoring device 30_3 is the communication slave device is defined as group D.

[0133] In step S87, the monitoring device 30_3 performs a connection acceptance operation to become the communication master device of the control device 40. In step S88, the control device 40 performs a connection request operation to become the communication slave device of the monitoring device 30_3. Note that these connection acceptance operations and connection request operations may be processes that alternate the functions of the communication master device and the communication slave device. Then, in step S89, a connection establishment operation between the monitoring device 30_3 and the control device 40 is executed. At this time, a pair in which the monitoring device 30_3 is the communication master device and the control device 40 is the communication slave device is defined as group E.

[0134] Note that the communication connection of a pair in which the control device 40 is the communication master device and the monitoring device 30_1 is the communication slave device has already been established. This pair is defined as group F. Also, as described above, the order in which the connection establishment operation is executed between the control device 40 and each of the monitoring devices 30_1, 30_2, and 30_3 is not limited to the example shown in the flowchart of FIG. 13.

[0135] In the periodic communication in step S90, communication between the communication master units and communication slave units belonging to groups C to F is performed in a predetermined order. At this time, similar to the second embodiment, one of the control device 40 or the monitoring devices 30_1, 30_2, 30_3 that monitors the battery stack 21 indicating a relatively high charge amount in the periodic communication is the group to which the pair of the communication master unit belongs. It is preferable to manage the periodic alternation of the groups that perform communication so that the opportunity for communication is increased compared to the opportunity for communication of the group to which the pair of the monitoring device 30 that monitors the battery stack 21 indicating a relatively low charge amount as the communication master unit belongs.

[0136] (Other embodiments) The disclosure in this specification, drawings, etc. is not limited to the illustrated embodiments. The disclosure includes the illustrated embodiments and modifications by those skilled in the art based on them. 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 those in which parts and / or elements of the embodiments are omitted. The disclosure includes the replacement or combination of parts and / or elements between one embodiment and another. The technical scope disclosed is not limited to the description of the embodiments. Some of the technical scopes disclosed are indicated by the description of the claims, and should be understood to include all changes within the meaning and scope equivalent to the description of the claims.

[0137] The disclosure in the specification, drawings, etc. is not limited by the description of the claims. The disclosure in the specification, drawings, etc. includes the technical idea described in the claims, and further extends to more diverse and extensive technical ideas than the technical idea described in the claims. Therefore, various technical ideas can be extracted from the disclosure in the specification, drawings, etc. without being restricted by the description of the claims.

[0138] When an element or layer is referred to as being "on," "connected to," "attached to," or "coupled to" another element or layer, it can be directly on, connected to, attached to, or coupled to the other element or layer, and there may also be intervening elements or intervening layers. In contrast, when an element is referred to as being "directly on," "directly connected to," "directly attached to," or "directly coupled to" another element or layer, there are no intervening elements or intervening layers. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "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.

[0139] Spatially relative terms such as "inside," "outside," "beneath," "below," "lower," "above," "upper," etc. are used herein to facilitate description of the relationship of one element or feature to another element or feature as illustrated. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the figures is turned over, elements described as "beneath" or "under" other elements or features would then be oriented "above" the other elements or features. Thus, the term "beneath" can encompass both an orientation of above and below. The device may be oriented in other directions (rotated 90 degrees or other orientations), and the spatially relative descriptors used in this specification are to be interpreted accordingly.

[0140] The devices, systems, and methods described in this disclosure may be implemented by a dedicated computer configured to program a processor to execute one or more functions embodied by a computer program. Alternatively, the devices and methods described in this disclosure may be implemented by dedicated hardware logic circuits. Or, the devices and methods described in this disclosure may be implemented by one or more dedicated computers configured by a combination of a processor that executes a computer program and one or more hardware logic circuits. Also, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions to be executed by a computer.

[0141] For example, although an example in which the monitoring device 30 includes the microcomputer 34 is shown, the present invention is not limited to this. A battery management system 60 having a configuration in which the monitoring device 30 does not include the microcomputer 34 may be employed. In this configuration, the wireless IC 35 transmits and receives data to and from the monitoring IC 33. Regarding the sensing and self-diagnosis schedule control by the monitoring IC 33, the wireless IC 35 may execute them, or the main microcomputer 45 of the control device 40 may execute them.

[0142] Although an example in which the monitoring device 30 is arranged for each battery stack 21 is shown, the present invention is not limited to this. For example, one monitoring device 30 may be arranged for a plurality of battery stacks 21. A plurality of monitoring devices 30 may be arranged for one battery stack 21.

[0143] Although an example in which the battery pack 11 includes one control device 40 is shown, the present invention is not limited to this. A plurality of control devices 40 may be included. Although an example in which the monitoring device 30 includes one monitoring IC 33 is shown, 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 a plurality of monitoring ICs 33.

[0144] The arrangement and number of the battery stacks 21 and battery cells 22 that make up the assembled battery 20 are not limited to the above-described example. In the battery pack 11, the arrangement of the monitoring device 30 and / or the control device 40 is not limited to the above-described example.

[0145] In each of the above-described embodiments, the monitoring system of the present disclosure is embodied as a battery management system 60 configured to monitor each battery stack 21 of the assembled battery 20. However, the monitoring system according to the present disclosure can also be applied to monitor a monitoring target other than each battery stack 21 of the assembled battery 20. For example, the monitoring system according to the present disclosure may be embodied as a system that performs wireless communication with a pneumatic pressure sensor unit incorporated in each wheel of a vehicle to monitor each pneumatic pressure sensor unit. In this case, each monitoring device is provided on each wheel, and at least one control device is provided inside the vehicle.

Description of Reference Numerals

[0146] 10…Vehicle, 11…Battery pack, 12…PCU, 13…MG, 14…ECU, 15…Battery, 20…Assembled battery, 21…Battery stack, 22…Battery cell, 23…Bus bar unit, 24…Bus bar, 25…Positive terminal, 26…Negative terminal, 27…Bus bar cover, 30…Monitoring device, 31, 311, 312, 313…Power supply circuit, 32…Multiplexer, 33…Monitoring IC, 34…Microcomputer, 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 microcomputer, 46…Sub-microcomputer, 50…Housing, 60…Battery management system, 70…Sensor

Claims

1. A plurality of monitoring devices (30) provided on a device to be monitored and monitoring the device to be monitored; A control device (40) that performs wireless communication with the plurality of monitoring devices and acquires monitoring information of the device to be monitored from the plurality of monitoring devices. The device to be monitored is a battery pack composed of a plurality of battery stacks; The plurality of monitoring devices respectively monitor the plurality of battery stacks; The battery pack can be switched between an operating state in which charging and discharging are performed and a non-operating state in which charging and discharging are not necessary; The control device detects the switching between the operating state and the non-operating state and notifies the plurality of monitoring devices; In the operating state, the control device serves as a communication master device and performs wireless communication via communication connections individually established with each of the plurality of monitoring devices which are communication slave devices; In the non-operating state, when the control device and the plurality of monitoring devices are defined as wireless communication nodes, a monitoring system in which the plurality of nodes are connected in series to perform wireless communication, and in the series relationship, a node sandwiched between two nodes becomes a communication master device with respect to one node and a communication slave device with respect to the other node, thereby maintaining the communication connection between the control device and the plurality of monitoring devices.

2. The monitoring system according to claim 1, wherein the control device is powered from a power source different from the power source that powers the plurality of monitoring devices.

3. The monitoring system according to claim 1 or 2, wherein the control device maintains one of the communication connections individually established with each of the plurality of monitoring devices during the operating state in response to detecting the switching of the device to be monitored from the operating state to the non-operating state, thereby becoming a communication master device with respect to one of the plurality of monitoring devices.

4. The monitoring system according to any one of claims 1 to 3, wherein the control device becomes a communication master device with respect to one of the plurality of monitoring devices and a communication slave device with respect to one of the plurality of monitoring devices that serves as a communication master device.

5. The monitoring system according to claim 4, wherein the control device utilizes one of the communication connections individually established with each of the plurality of monitoring devices during the operating state in response to detecting the switching of the device to be monitored from the operating state to the non-operating state, and by changing the roles of the communication master device and the communication slave device with the monitoring device that was a communication slave device, becomes a communication slave device with respect to one of the plurality of monitoring devices that serves as a communication master device.

6. The control device, in response to detecting a switch from a non-operating state to an operating state of the device under monitoring, maintains the communication connection with one of the plurality of monitoring devices that was the communication master device when in the non-operating state, and individually establishes a communication connection with each of the remaining plurality of monitoring devices. The monitoring system according to any one of claims 1 to 5.

7. The control device, in response to detecting a switch from a non-operating state to an operating state of the device under monitoring, exchanges the roles of the communication master device and the communication slave device with one of the plurality of monitoring devices that was the communication master device of the control device when in the non-operating state, and establishes an individual communication connection with one of the plurality of monitoring devices that was the communication master device as a communication slave device. The monitoring system according to claim 6.

8. Notification of detecting the switch from the non-operating state to the operating state of the device under monitoring is transmitted directly or indirectly from the control device to each of the plurality of monitoring devices via the communication connection maintained in the non-operating state of the device under monitoring. The monitoring system according to claim 6 or 7.

9. In the non-operating state of the device under monitoring, the plurality of pairs of the communication master device and the communication slave device set between the control device and the plurality of monitoring devices are divided into a plurality of groups, and the groups for communication are periodically changed. The monitoring system according to any one of claims 1 to 8.

10. Each of the plurality of groups includes a plurality of pairs of the communication master device and the communication slave device. The monitoring system according to claim 9.

11. The device under monitoring is a battery pack composed of a plurality of battery stacks. The plurality of monitoring devices monitor the plurality of battery stacks respectively and are powered by the battery stack to be monitored. When an imbalance is detected in the charge levels of the plurality of battery stacks by the plurality of monitoring devices, the control device or one of the plurality of monitoring devices manages the periodic change of the communication group so that the opportunity for the monitoring device monitoring the battery stack with a relatively high charge level to become the communication master device increases compared to the opportunity for the monitoring device monitoring the battery stack with a relatively low charge level to become the communication master device. The monitoring system according to claim 9 or 10.

12. When the group that performs communication periodically alternates, the communication period of the group in which the monitoring device that monitors the battery stack having the relatively high state of charge becomes the communication master unit is longer than the communication period of the group in which the monitoring device that monitors the battery stack having the relatively low state of charge becomes the communication master unit. The monitoring system according to claim 11, wherein the periodic alternation of the group that performs communication is managed by the control device or one of the plurality of monitoring devices.

13. When the group that performs communication periodically alternates, the selection frequency of the group in which the monitoring device that monitors the battery stack having the relatively high state of charge becomes the communication master unit is higher than the selection frequency of the group in which the monitoring device that monitors the battery stack having the relatively low state of charge becomes the communication master unit. The monitoring system according to claim 11, wherein the periodic alternation of the group that performs communication is managed by the control device or one of the plurality of monitoring devices.

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