Surveillance system

Abstract

To provide a monitoring system capable of reducing, in a non-operating state of a monitored apparatus, power consumption of a control device that communicates with a plurality of monitoring devices in an operating state of the monitored apparatus.SOLUTION: In a non-operating state of a battery pack 20 as a monitored apparatus, a communication connection in which one of a plurality of monitoring devices 30 serves as a communication master unit and another serves as a communication slave unit is formed among the plurality of monitoring devices 30. A control device 40 is configured so as to disconnect the communication connection with the plurality of monitoring devices 30 or communicate with at least one of the plurality of monitoring devices 30 at a lower frequency than that of communication between the plurality of monitoring devices 30.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to a monitoring system for monitoring a monitored device, such as an assembled battery, 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 each of a plurality of battery cell groups and configured to respectively acquire measurement results regarding the charging states of the battery cells of the corresponding battery cell groups, and a battery pack management device that performs 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 a monitoring system that monitors a monitored device using a plurality of monitoring devices, such as the above-described battery control system, when the monitored device becomes non-operational, if communication similar to that in the operational state is performed between the control device and the plurality of monitoring devices, the magnitude of power consumption in the control device can become a problem.

[0005] The present disclosure has been made in view of the above points, and an object thereof is to provide a monitoring system capable of reducing the power consumption of a control device in a non-operational state of a monitored device.

Means for Solving the Problems

[0006] To achieve the above object, a monitoring system according to the present disclosure includes a plurality of monitoring devices (30) provided in the monitored device and configured to monitor the monitored device, A control device (40) that performs wireless communication with a plurality of monitoring devices and acquires monitoring information of a device under monitoring 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 and Not required to perform charge and discharge a non-operating state, and The control device detects the switching from the operating state to the non-operating state and notifies the plurality of monitoring devices, in the non-operating state of the device under monitoring, a communication connection is formed between the plurality of monitoring devices such that one of the plurality of monitoring devices becomes a communication master device and another one becomes a communication slave device. The communication connection is formed such that each of the plurality of monitoring devices becomes a communication master device with respect to other monitoring devices and also becomes a communication slave device of monitoring devices other than the monitoring device that becomes the communication master device. The plurality of monitoring devices communicate regularly via the formed communication connection. In the non-operating state of the device under monitoring, the control device disconnects the communication connection with the plurality of monitoring devices or The control device serves as the communication master device, communicates with at least one of the plurality of monitoring devices at a lower frequency than the communication between the plurality of monitoring devices. Serves as the communication slave device is configured to be.

[0007] As described above, in the non-operating state of the device under monitoring, a communication connection is formed between the plurality of monitoring devices such that one of the plurality of monitoring devices becomes a communication master device and another one becomes a communication slave device. On the other hand, in the non-operating state of the device under monitoring, the control device disconnects the communication connection with the plurality of monitoring devices or The control device serves as the communication master device, communicates with at least one of the plurality of monitoring devices at a lower frequency than the communication between the plurality of monitoring devices. Therefore, the power consumption of the control device in the non-operating state of the device under monitoring can be reduced. Serves as the communication slave device

[0008] The reference numbers in the above parentheses are merely examples of the correspondence with the specific configurations in the embodiments described later for ease of understanding of the present disclosure, and are not intended to limit the scope of the present disclosure in any way.

[0009] ​Regarding the technical features described in each claim of the claims other than the above-described features, they will become apparent from the description of the embodiments and the accompanying drawings described later.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Modes for Carrying Out the Invention

[0011] Hereinafter, a plurality of embodiments will be described with reference to the drawings. In each embodiment, corresponding components may be denoted by the same reference numerals, and redundant descriptions 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 stated.

[0012] (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 the battery management system, will be described. FIG. 1 is a diagram showing a schematic configuration of the vehicle. The vehicle is an electric vehicle such as a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV). The battery management system can also be applied to moving bodies other than vehicles, such as flying bodies like drones, ships, construction machinery, agricultural machinery, etc. The battery management system can also be applied to stationary batteries (storage batteries) for household or business use.

[0013] <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.

[0014] The battery pack 11 includes a battery module 20 to be described later and provides a DC voltage source capable of charging and discharging. 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.

[0015] The battery pack 11 is arranged in the front compartment of the vehicle 10 as shown in FIG. 1, for example. 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 an engine compartment, an engine room, etc.

[0016] The temperature of the battery pack 11 is adjusted by the running wind of the vehicle 10 or the cooling air supplied from the fan mounted on the vehicle 10. The temperature of the battery pack 11 may be adjusted by the cooling liquid circulating inside the vehicle 10. By the above temperature adjustment, excessive temperature changes of the battery pack 11 are suppressed. Note that the battery pack 11 may simply be connected in a heat-conductive manner to a member having a large heat capacity such as the body of the vehicle 10.

[0017] 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 arranged 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 module 20 of the battery pack 11 with the DC voltage obtained by bucking the DC voltage output from the inverter.

[0018] The MG 13 is an AC rotating electric machine, for example, a three-phase AC synchronous motor in which permanent magnets are embedded in the 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 module 20 in the battery pack 11.

[0019] ECU14 is configured to include a computer having a processor, a memory, an input / output interface, a bus for 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 tangible storage medium that non-temporarily stores programs and data that can be read by a computer. The memory stores various programs executed by the processor.

[0020] ECU14, for example, acquires information about the battery pack 11 and the battery module 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 module 20 from the battery pack 11. ECU14 may acquire battery information such as the voltage, temperature, and current of the battery module 20 and calculate the SOC and SOH. SOC is an abbreviation for State Of Charge. SOH is an abbreviation for State Of Health.

[0021] 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, a 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.

[0022] <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.

[0023] 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 lateral 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 positional relationship of being orthogonal to each other. 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.

[0024] 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.

[0025] 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 cells 22.

[0026] In addition, 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 a 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.

[0027] 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 above-described DC voltage source. The assembled battery 20, the battery stack 21, and the battery cell 22 correspond to a battery.

[0028] 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 using lithium as a charge carrier. The secondary battery that can be adopted for the battery cell 22 may include not only a secondary battery with a liquid electrolyte but also a so-called all-solid-state battery using a solid electrolyte.

[0029] 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.

[0030] 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 positions in the Z direction 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.

[0031] 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 of 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 is arranged in each battery stack 21.

[0032] 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 that are alternately arranged 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 adjacent battery cells 22 in the Y direction. Thereby, in each battery stack 21, a plurality of battery cells 22 are connected in series.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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 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.

[0037] The bus bar cover 27 is formed using an electrically insulating material such as resin. The bus bar cover 27 is linearly provided from one end to the other 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.

[0038] 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 with each other facing each other in the Z direction. An intervening material such as an insulating sheet may be provided between the monitoring device 30 and this end face.

[0039] The monitoring device 30 is fixed to the bus bar unit 23 with screws or the like. As will be described later, the monitoring device 30 is configured to be capable of wireless communication with the control device 40. An antenna 37, which will 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.

[0040] In addition, as the material of the 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, as the constituent material of the components provided in the battery stack 21, particularly components that do not necessarily need to have magnetism, a non-magnetic material can be adopted.

[0041] In this 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 equal. Due to the configuration shown above, the extension of the separation distance between the plurality of monitoring devices 30 is suppressed.

[0042] 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.

[0043] 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 is provided with the battery management system 60.

[0044] In order to prevent the battery pack 11 from becoming an electromagnetic noise source, it is necessary to suppress the leakage of the radio wave 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 of this wireless communication, it is necessary to suppress the intrusion of electromagnetic noise into the communication space.

[0045] Therefore, 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 fiber. Instead of the performance of reflecting electromagnetic waves, the housing 50 may have the performance of absorbing electromagnetic waves.

[0046] The housing 50 may have a hole that communicates between its inner accommodation space and the outer space (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.

[0047] 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.

[0048] 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 fiber. The covering portion contains a resin material.

[0049] The hole in the housing 50 may be covered by at least one of the elements housed in the housing space of the housing 50. The separation distance between the contained object and the hole is shorter than the length of the hole described above. Also, power lines and signal lines may be arranged across the housing space and the external space while being held by an electrical insulating member that forms part of the wall of the housing 50.

[0050] <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.

[0051] 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.

[0052] 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 one node is a master and the remaining nodes are slaves, and wireless communication is performed between all of the master and the slaves. Another form of network communication is chain communication in which a plurality of nodes are connected in series and wireless communication is performed.

[0053] The battery management system 60 further includes a sensor 70. The sensor 70 includes a physical quantity detection sensor that detects a 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] <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.

[0058] The power supply circuit 31 generates the operating power supply for other circuit elements included in the monitoring device 30 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 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 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 using the voltage generated by the power supply circuit 311 and supplies it to the wireless IC 35.

[0059] 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.

[0060] The monitoring IC 33 senses (acquires) battery information such as the 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 in association with which battery cell 22 the value belongs to. 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.

[0061] The monitoring IC 33 is sometimes referred to as a cell monitoring 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 examples, the battery monitoring information may include information such as the exhaust temperature, impedance, state of equalization of cell voltages, stack voltage, state of synchronization with the control device 40, and presence or absence of abnormality in the detection wiring.

[0062] 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.

[0063] The microcontroller 34 controls the schedule of sensing and self-diagnosis by the monitoring IC 33. The microcontroller 34 receives the battery monitoring information transmitted from the monitoring IC 33 and transmits it to the wireless IC 35. The microcontroller 34 transmits data requesting the acquisition of battery monitoring information to the monitoring IC 33. For example, when the microcontroller 34 receives data requesting the acquisition of battery monitoring information transmitted from the wireless IC 35, it may transmit data requesting the acquisition of battery monitoring information to the monitoring IC 33. The microcontroller 34 may autonomously request the acquisition of battery monitoring information from the monitoring IC 33. For example, the microcontroller 34 may periodically request the acquisition of battery monitoring information from the monitoring IC 33. Further, the microcontroller 34 may request other monitoring devices 30 to acquire and transmit battery monitoring information via the wireless IC 35 or the like in order to collect the battery monitoring information of other monitoring devices 30. The collected battery monitoring information of other monitoring devices 30 is stored in the memory of the microcontroller 34.

[0064] The wireless IC 35 includes an RF circuit (not shown) and a microcontroller for wirelessly transmitting and receiving data. The microcontroller includes a memory. The wireless IC 35 has a transmission function of modulating transmission data and oscillating at the frequency of the RF signal. The wireless IC 35 has a reception function of demodulating received data. RF is an abbreviation for radio frequency.

[0065] The wireless IC 35 modulates the data including the battery monitoring information transmitted from the microcontroller 34 and transmits it to other nodes such as the control device 40 via the front-end circuit 36 and the antenna 37. The wireless IC 35 adds data necessary for wireless communication such as communication control information to the transmission data including the battery monitoring information and transmits it. The data necessary for wireless communication includes, for example, an identifier (ID), 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 with other nodes.

[0066] The wireless IC 35 receives and demodulates data transmitted from other nodes via the antenna 37 and the front-end circuit 36. When the wireless IC 35 receives data including, for example, a transmission request for battery monitoring information, it transmits data including battery monitoring information to other nodes as a response to the request. The monitoring device 30 may transmit battery traceability information and / or manufacturing history information to other nodes in addition to the above-described battery monitoring information. The battery traceability information is, for example, the number of charge / discharge cycles, the number of failures, the total charge / discharge time, etc. The manufacturing history information is, for example, the date of manufacture, location, manufacturer, serial number, manufacturing number, etc. The manufacturing history information is stored in the memory included 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.

[0067] 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.

[0068] The antenna 37 converts an electrical signal into a radio wave and radiates it into space. The antenna 37 receives a radio wave propagating through space and converts it into an electrical signal.

[0069] <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.

[0070] The power supply circuit 41 generates the 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 auxiliary 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 figure, 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.

[0071] The antenna 42 converts an electrical signal into a radio wave and radiates it into space. The antenna 42 receives a radio wave propagating through space and converts it into an electrical signal.

[0072] 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.

[0073] The wireless IC 44 includes an RF circuit and a microcomputer (not shown) for wirelessly transmitting and receiving data. The wireless IC 44 has a transmitter function and a receiver function similar to the wireless IC 35. 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 adds data necessary for wireless communication, such as communication control information, to the transmitted data and 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 wireless communication with other nodes.

[0074] The main microcomputer 45 is a microcomputer including a CPU, a ROM, a RAM, an input / output interface, and a bus connecting these components. The ROM stores various programs to be executed by the CPU. The main microcomputer 45 generates a command to request a predetermined process from the monitoring device 30, and transmits transmission data including the command to the wireless IC 44. The main microcomputer 45 generates, for example, a command to request transmission of battery monitoring information. The main microcomputer 45 may generate a command to request acquisition of battery monitoring information and also request transmission of the battery monitoring information. The requests described in this specification may be referred to as instructions.

[0075] 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, the open circuit voltage (OCV), the state of charge (SOC), and the state of health (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.

[0076] The main microcomputer 45 performs an estimation process of the internal resistance and the 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 the open circuit voltage of the battery cell 22 in consideration of, for example, the cell temperature as well.

[0077] The main microcomputer 45 may instruct the execution of an equalization process to equalize 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 abnormalities in the battery cells 22 and the circuit based on the battery monitoring information, or may transmit the abnormality detection information to the ECU 14.

[0078] The sub-microcomputer 46 is a microcomputer including a CPU, a ROM, a RAM, an input / output interface, and a bus connecting these. The ROM stores various programs executed by the CPU. The sub-microcomputer 46 executes monitoring processing within the control device 40. For example, the sub-microcomputer 46 may monitor data between the wireless IC 44 and the main microcomputer 45. The sub-microcomputer 46 may monitor the state of the main microcomputer 45. The sub-microcomputer 46 may monitor the state of the wireless IC 44.

[0079] <Communication in the operating state> The battery management system 60 of the present embodiment performs star-type network communication in the operating state of the assembled battery 20 that supplies power to in-vehicle systems such as the MG13 from the assembled battery 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 process with all the monitoring devices 30. Note that the communication form between the control device 40 and the plurality of monitoring devices 30 in the operating state of the assembled battery 20 is not limited to star-type network communication, and may be chain-type network communication.

[0080] First, based on FIGS. 5 and 6, a 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 a 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 the ECU 40.

[0081] As shown in FIG. 5, in order to 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, individually with each of the plurality of monitoring devices 30, a connection process (S10) is performed between the control device 40 and each monitoring device 30. When the control device 40 and each monitoring device 30 perform communication 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.

[0082] In the connection establishment process (S11), the control device 40 executes a scan operation (S111), and the monitoring device 30 executes an advertise operation (S112). The start of the scan operation may be earlier than the start of the advertise operation, may be at approximately the same timing, or may be later than the start of the advertise operation.

[0083] The wireless IC 35 of the monitoring device 30 executes an advertise operation and transmits an advertisement packet (ADV_PKT) to the wireless IC 44 of the control device 40 in order to convey its own presence to the control device 40. The advertisement packet includes ID information of itself (monitoring device 30) and the control device 40, etc.

[0084] 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).

[0085] When the monitoring device 30 receives a 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.

[0086] When the connection establishment process ends, then the pairing process (S12) is executed. The pairing process is a process for performing encrypted data communication. The pairing process includes an exchange process (S121) of unique information. In this exchange process, the unique information (for example, an encryption key or information for generating an encryption key) held by each other is exchanged and stored in each memory. After the execution of the process of step S121, encryption using the exchanged unique information becomes possible.

[0087] Although an example in which the control device 40 executes a scan operation and the monitoring device 30 executes an advertisement operation has been shown, it is not limited to this. A configuration in which the monitoring device 30 executes a scan operation and the control device 40 executes an advertisement operation may also be used.

[0088] 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 the MIC 33, the wireless IC 35 is shown as the WIC 35, and the control device 40 is shown as the ECU 40.

[0089] 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 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 acquisition and transmission of battery monitoring information.

[0090] When the wireless IC 35 of the monitoring device 30 receives the request data, it transmits an acquisition request for 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.

[0091] When the monitoring IC 33 receives the acquisition request, it executes sensing (S23). The monitoring IC 33 executes sensing and acquires the battery information of each battery cell 22 through the multiplexer 32. In addition, the monitoring IC 33 executes a failure diagnosis of the circuit.

[0092] 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 is transmitted together with the battery information. The monitoring IC 33 transmits the battery monitoring information to the wireless IC 35 via the microcomputer 34.

[0093] 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.

[0094] 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).

[0095] 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.

[0096] <Communication in the non-operating state> FIG. 8(a) shows an example of a communication form (i.e., a star network) in the operating state of the assembled battery 20 in which the control device 40 serves as a communication master unit and individually communicates with a plurality of monitoring devices 30 that are communication slave units. For example, even in the non-operating state of the assembled battery 20 where the SMR is turned off as the ignition switch is turned off and power is not supplied to in-vehicle systems such as the MG13 connected via the SMR, if the communication form as shown in FIG. 8(a) is maintained as it is, the power consumption in the control device 40 increases, which may also cause premature depletion of the battery 15. The main reason is that the control device 40 needs to communicate with a plurality of monitoring devices 30, and the communication master unit function for performing communication schedule management and the like generally has a higher load than the communication slave unit function. Note that the assembled battery 20 supplies power to devices such as the monitoring device 30 directly connected to the assembled battery 20 even in the non-operating state of the assembled battery 20 without going through the SMR.

[0097] Therefore, the battery management system 60 according to the present embodiment switches to a communication form different from that in the operating state when the assembled battery 20 is in the non-operating state, so as to suppress the power consumption of the control device 40. Hereinafter, the communication form in the non-operating state of the assembled battery 20 will be described in detail.

[0098] 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 disconnects communication with a plurality of monitoring devices 30_1, 30_2, 30_3. Further, a communication connection is formed among the plurality of monitoring devices 30_1, 30_2, 30_3 such that one of the plurality of monitoring devices 30_1, 30_2, 30_3 serves as a communication master unit and another one serves as a communication slave unit. At this time, as shown in FIG. 8(b), communication connections are formed among the plurality of monitoring devices 30_1, 30_2, 30_3 such that each of the plurality of monitoring devices 30_1, 30_2, 30_3 becomes a communication master unit for other monitoring devices 30_1, 30_2, 30_3 and also becomes a communication slave unit for the monitoring devices 30_1, 30_2, 30_3 other than the monitoring devices 30_1, 30_2, 30_3 that serve as communication master units.

[0099] Note that, as shown in FIG. 8(b), the plurality of monitoring devices 30_1, 30_2, and 30_3 may communicate with each other via communication connections formed therebetween during the same period. Alternatively, the plurality of monitoring devices 30_1, 30_2, and 30_3 may communicate with each other via communication connections formed therebetween at different times. For example, first, communication may be performed between the monitoring device 30_1 and the monitoring device 30_2, and after a predetermined period, communication may be performed between the monitoring device 30_2 and the monitoring device 30_3, and after that predetermined period, communication may be performed between the monitoring device 30_3 and the monitoring device 30_1. In other words, the times when the plurality of monitoring devices 30_1, 30_2, and 30_3 communicate as a communication master device and the times when they communicate as a communication slave device may be different.

[0100] The plurality of monitoring devices 30_1, 30_2, and 30_3 communicate with each other regularly via the formed communication connections. For example, at least one of the plurality of monitoring devices 30_1, 30_2, and 30_3 collects battery monitoring information of at least one other monitoring device 30_1, 30_2, and 30_3. Then, when the assembled battery 20 is switched from the non-operating state to the operating state, at least one of the monitoring devices 30_1, 30_2, and 30_3 is configured to collectively provide the control device 40 with the battery monitoring information collected from the other monitoring devices 30_1, 30_2, and 30_3 and its own battery monitoring information. As a result, the control device 40 can obtain battery monitoring information regarding the plurality of battery stacks 21 only by communicating with the monitoring devices 30_1, 30_2, and 30_3 that hold the battery monitoring information collected from the other monitoring devices 30_1, 30_2, and 30_3. Then, the control device 40 can early determine whether it is possible to switch the assembled battery 20 to the operating state based on the battery monitoring information. As a result, the battery management system 60 according to the present embodiment can shorten the time required to shift the assembled battery 20 from the non-operating state to the operating state.

[0101] In the examples shown in FIGS. 8(a) and 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. Also, the number of control devices 40 is one, but two or more control devices 40 may be provided. When the number of monitoring devices 30 is relatively large, the monitoring devices may be divided into a plurality of groups, and in each group, a communication network as shown in FIG. 8(b) may be formed.

[0102] Next, with reference to the flowchart of FIG. 9, the processing in the control device 40 and each of the monitoring devices 30_1, 30_2, 30_3 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] In step S40, the control device 40 detects that the ignition switch has been turned off 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 triggers that the vehicle has stopped, the driver has gotten out of the vehicle, each door of the vehicle has been locked, and the like. When the control device 40 detects that the ignition switch has been turned off, it notifies each of the monitoring devices 30_1, 30_2, 30_3 that the ignition switch has been turned off. As a result, each of the monitoring devices 30_1, 30_2, 30_3 can grasp that it is necessary to change the form of the communication network to a network for the non-operating state of the assembled battery 20.

[0104] After the control device 40 notifies each monitoring device 30_1, 30_2, 30_3 that the ignition switch has been turned off, in step S41, it disconnects the communication with the plurality of monitoring devices 30_1, 30_2, 30_3. The process of this step S41 is executed at the latest until a communication connection is formed between each of the monitoring devices 30_1, 30_2, 30_3 and regular communication is started. Therefore, hereafter, since the control device 40 does not need to communicate with the plurality of monitoring devices 30_1, 30_2, 30_3, the power consumption by the control device 40 can be reduced. After disconnecting the communication, the control device 40 may shift to the sleep state. Thereby, further reduction of the power consumption by the control device 40 can be achieved. Note that the control device 40 that has shifted to the sleep state is triggered and woken up by the ignition switch being turned on, which will be described later.

[0105] The plurality of monitoring devices 30_1, 30_2, 30_3 execute a connection acceptance operation (scan operation) and a connection request operation (advertisement operation) to form a communication connection among the plurality of monitoring devices 30_1, 30_2, 30_3 such that each of them becomes the communication master device of another one of the monitoring devices 30_1, 30_2, 30_3 and the communication slave device of another different one of the monitoring devices 30_1, 30_2, 30_3. More specifically, each of the plurality of 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 monitoring device 30_1, 30_2, 30_3 that becomes the communication master device and the monitoring device 30_1, 30_2, 30_3 that becomes 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 detects that the ignition switch has been turned off, and may be notified to other devices 40, 30_1, 30_2, 30_3.

[0106] For example, in the example shown in the flowchart of FIG. 9, the monitoring device 30_1 performs a connection acceptance operation in step S42 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 S43 to become the communication slave device of the monitoring device 30_1. Then, in step S44, a connection establishment operation between the monitoring device 30_1 and the monitoring device 30_2 is executed. That is, as the connection establishment operation, the monitoring device 30_1, which is the communication master device, detects an advertisement packet from the monitoring device 30_2, which is the communication slave device, and transmits a connection request (CONNECT_REQ) to the monitoring device 30_2, which is the communication slave device. Further, the monitoring device 30_1, which is the communication master device, and the monitoring device 30_2, which is the communication slave device, exchange unique information.

[0107] Also, in the example shown in the flowchart of FIG. 9, after the completion of the connection establishment operation in step S44, the monitoring device 30_2 performs a connection acceptance operation in step S45 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 S46 to become the communication slave device of the monitoring device 30_2. Then, in step S47, a connection establishment operation between the monitoring device 30_2 and the monitoring device 30_3 is executed.

[0108] Furthermore, in the example shown in the flowchart of FIG. 9, after the completion of the connection establishment operation in step S47, the monitoring device 30_3 performs a connection acceptance operation in step S48 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 S49 to become the communication slave device of the monitoring device 30_3. Then, in step S50, a connection establishment operation between the monitoring device 30_1 and the monitoring device 30_3 is executed.

[0109] The flowchart of FIG. 9 shows an example in which the connection establishment operations between the monitoring device 30_1 and the monitoring device 30_2 are first executed, then the connection establishment operations between the monitoring device 30_2 and the monitoring device 30_3 are executed, and finally the connection establishment operations between the monitoring device 30_1 and the monitoring device 30_3 are executed. However, in reality, the plurality of monitoring devices 30_1, 30_2, 30_3 each repeat the connection reception operation and the connection request operation periodically. And, between the communication slave unit and the communication master unit that should be paired, the connection establishment operation is performed from the pair in which the advertisement packet and the connection request in response thereto are transmitted and received. When each of the monitoring devices 30_1, 30_2, 30_3 has performed the connection establishment operation as the communication master unit first, thereafter, the connection reception 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 each of the monitoring devices 30_1, 30_2, 30_3 has performed the connection establishment operation as the communication slave unit first, thereafter, the connection request operation is stopped, and only the connection reception operation is continued until the connection establishment operation as the communication master unit is completed.

[0110] By the processing in the above-described control device 40 and each of the monitoring devices 30_1, 30_2, 30_3, the chain-type network shown in FIG. 8(b) is formed. In step S51 of the flowchart of FIG. 9, in the chain-type network formed by the plurality of monitoring devices 30_1, 30_2, 30_3, regular communication is performed between pairs of respective communication master units and communication slave units.

[0111] As described above, each of the plurality of monitoring devices 30_1, 30_2, 30_3 can acquire battery monitoring information including the voltage values of the plurality of battery cells 22 included in the battery stack 21. When there are variations in the voltage values of the plurality of battery cells 22 constituting the assembled battery 20, the chargeable amount of the assembled battery 20 is limited by the battery cell 22 having the maximum voltage value. As a result, the chargeable amount and the dischargeable amount of the assembled battery 20 are also limited. Therefore, the battery management system 60 according to the present embodiment performs an equalization process for equalizing the voltage values of the plurality of battery cells 22 in the operating state or the non-operating state of the assembled battery.

[0112] The equalization process may be a passive equalization process that discharges a battery cell 22 having a relatively high voltage value so that the voltage values of a plurality of battery cells 22 are adjusted to the lowest voltage value, or it may be an active equalization process that charges a battery cell 22 having a relatively low voltage value with the charge discharged from a battery cell 22 having a relatively high voltage value. Further, the equalization process may be a combination of a passive equalization process and an active equalization process. The function of performing such a passive equalization process and / or active equalization process can be assumed by, for example, the monitoring IC 33 of the monitoring device 30.

[0113] Whether or not it is necessary to perform the equalization process in the non-operating state of the battery pack 20 is determined by, for example, the control device 40 based on the battery monitoring information received from each of the monitoring devices 30_1, 30_2, 30_3 when it detects that the ignition switch has been turned off. If it is necessary to execute the equalization process, the control device 40 may instruct each of the monitoring devices 30_1, 30_2, 30_3. The instruction to execute the equalization process may include, for example, a target voltage value, the content of the equalization process (e.g., whether it is a passive equalization process or an active equalization process), and the like. Alternatively, in the chain-type network formed by the plurality of monitoring devices 30_1, 30_2, 30_3 described above, any one of the monitoring devices 30_1, 30_2, 30_3 may determine whether the equalization process is necessary based on the battery monitoring information acquired by each of the monitoring devices 30_1, 30_2, 30_3 and instruct each of the monitoring devices 30_1, 30_2, 30_3. Or, before the communication is disconnected, the control device 40 may instruct the execution of the equalization process, and after the communication is disconnected, any one of the monitoring devices 30_1, 30_2, 30_3 may manage whether the equalization process instructed by the control device 40 has been successfully completed in each of the monitoring devices 30_1, 30_2, 30_3.

[0114] When the battery pack 20 is in a non-operating state and at least equalization processing is performed, after the equalization processing is completed, the battery monitoring information acquired by each monitoring device 30_1, 30_2, 30_3 is aggregated to at least one of the monitoring devices 30_1, 30_2, 30_3 via the above-described periodic communication. In other words, at least one of the monitoring devices 30_1, 30_2, 30_3 collects and stores the battery monitoring information of at least one of the monitoring devices 30_1, 30_2, 30_3 via the periodic communication. For example, one of the monitoring devices 30_1, 30_2, 30_3 may aggregate the battery monitoring information of all the monitoring devices 30_1, 30_2, 30_3. Alternatively, the plurality of monitoring devices 30_1, 30_2, 30_3 may be divided into two or more groups, and for each group, one of the monitoring devices 30_1, 30_2, 30_3 may aggregate the battery monitoring information of the monitoring devices 30_1, 30_2, 30_3 belonging to the group.

[0115] Even when it is not necessary to perform the equalization processing, it is desirable that at least one of the monitoring devices 30_1, 30_2, 30_3 collects and stores the battery monitoring information of at least one of the monitoring devices 30_1, 30_2, 30_3 via the periodic communication.

[0116] The control device 40 knows the monitoring devices 30_1, 30_2, 30_3 that store the battery monitoring information of the other monitoring devices 30_1, 30_2, 30_3. Therefore, when the control device 40 detects that the ignition switch has been turned on, it preferentially starts communication with the monitoring devices 30_1, 30_2, 30_3 that store the battery monitoring information of the other monitoring devices 30_1, 30_2, 30_3, so that the battery monitoring information regarding the plurality of battery stacks 21 can be collectively acquired. Therefore, based on the battery monitoring information, it is possible to early determine whether or not it is possible to switch to the operating state of the battery pack 20.

[0117] As described above, the periodic communication among the plurality of monitoring devices 30_1, 30_2, and 30_3 is performed for instructing the execution of the equalization process and transmitting the battery monitoring information. Therefore, for example, after the equalization process is completed and / or after the transmission of the battery monitoring information is finished, the necessity of performing the periodic communication decreases. Thus, the monitoring devices 30_1, 30_2, and 30_3 for which the equalization process has been completed and / or the transmission of the battery monitoring information has been finished may reduce the frequency of the periodic communication compared to the previous periodic communication. For example, in order to reduce the frequency of the periodic communication, the period of performing the periodic communication can be lengthened, or the amount of communication data per communication can be reduced by stopping the transmission of the battery monitoring information, thereby shortening the communication time per time. The periodic communication may be performed to such an extent that the communication connection between the paired monitoring devices 30_1, 30_2, and 30_3 can be maintained.

[0118] Alternatively, the monitoring devices 30_1, 30_2, and 30_3 for which the equalization process has been completed and / or the transmission of the battery monitoring information has been finished may terminate the communication with the other paired monitoring devices 30_1, 30_2, and 30_3. However, in this case, when the control device 40 starts the scan operation in response to the ignition switch being turned on, each of the monitoring devices 30_1, 30_2, and 30_3 needs to periodically perform a connection request operation to the control device 40 so that the control device 40 can receive the advertisement packets from each of the monitoring devices 30_1, 30_2, and 30_3.

[0119] In step S52 of the flowchart in FIG. 9, the control device 40 wakes up when the ignition switch is turned on, and 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 for waking up the control device 40 and indicating the switching of the assembled battery 20 from the non-operating state to the operating state may be detected by the user holding the smart key approaching the vehicle, the vehicle door lock being released, the driver sitting on the driver's seat, or the like.

[0120] When the control device 40 detects that the ignition switch has been turned on, in step S53, it starts the connection acceptance operation (scanning operation). As shown in step S54 of the flowchart in FIG. 9, at least one monitoring device 30_1 periodically performs a connection request operation to the control device 40 even while performing periodic communication with other monitoring devices 30_2 and 30_3. The control device 40 executes a connection establishment operation with the monitoring device 30_1 in step S55. That is, the control device 40 receives an advertisement packet from the monitoring device 30_1, sends a connection request to the monitoring device 30_1, and exchanges unique information with the monitoring device 30_1. Then, the control device 40 notifies the monitoring device 30_1 that the ignition switch has been turned on via the established communication connection.

[0121] Then, the monitoring device 30_1 notifies other monitoring devices 30_2 and 30_3 that the ignition switch has been turned on via the chain-type network shown in FIG. 8(b). As a result, each of the monitoring devices 30_2 and 30_3 can recognize that it is necessary to change the form of the communication network to the star-type network for the operating state of the battery pack 20 shown in FIG. 8(a).

[0122] Since the control device 40 becomes the communication master device of each of the monitoring devices 30_2 and 30_3, and each of the monitoring devices 30_2 and 30_3 becomes the communication slave device of the control device 40, the control device 40 and each of the monitoring devices 30_2 and 30_3 execute a connection acceptance operation (scanning operation) and a connection request operation (advertising operation). More specifically, the control device 40 continues the connection acceptance operation in step S53, and the monitoring devices 30_2 and 30_3 perform connection request operations in steps S56 and S57. Then, in step S58, a connection establishment operation between the control device 40 and each of the monitoring devices 30_2 and 30_3 is executed.

[0123] In the non-operating state of the battery pack 20, the communication connection between the monitoring devices 30_1, 30_2, and 30_3 forming the chain-type network shown in FIG. 8(b) is disconnected at the latest until the ignition switch is detected to be turned on and transmitted to each of the monitoring devices 30_1, 30_2, and 30_3, and regular communication between the control device 40 and each of the monitoring devices 30_1, 30_2, and 30_3 starts.

[0124] (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. For this reason, the description of the configuration of the battery management system 60 according to the present embodiment is omitted.

[0125] Similar to the first embodiment, when the battery pack 20 is in a non-operating state, the battery management system 60 according to the present embodiment switches to a communication mode different from that in the operating state to suppress the power consumption of the control device 40. However, unlike the first embodiment, the battery management system 60 according to the present embodiment does not cut off all communication connections with the plurality of monitoring devices 30_1, 30_2, and 30_3, but maintains a communication connection with at least one of the plurality of monitoring devices 30_1, 30_2, and 30_3. However, the communication between the control device 40 and at least one of the plurality of monitoring devices 30_1, 30_2, and 30_3 is performed at a lower frequency than the communication between the plurality of monitoring devices 30_1, 30_2, and 30_3. For example, the communication frequency can be reduced by increasing the communication cycle or reducing the communication data volume by not transmitting battery monitoring information between the control device 40 and at least one of the plurality of monitoring devices 30_1, 30_2, and 30_3. Thereby, the control device 40 can reduce power consumption while maintaining a communication connection with at least one of the plurality of monitoring devices 30_1, 30_2, and 30_3.

[0126] FIG. 10 shows the form of the communication network in the non-operating state of the assembled battery 20 in the present embodiment. That is, as shown in FIG. 10, a plurality of monitoring devices 30_1, 30_2, 30_3 form a chain-type network, and the control device 40 maintains a communication connection with the monitoring device 30_1. Note that at least one monitoring device with which the control device 40 communicates is not limited to the monitoring device 30_1. Also, when the monitoring devices 30 are divided into a plurality of groups and a communication network as shown in FIG. 8(b) is formed in each group, the control device 40 maintains a communication connection with at least one monitoring device 30 belonging to each group.

[0127] 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 the present embodiment will be described.

[0128] The processing in step S60 in the flowchart of FIG. 11 is the same as the processing in step S40 in the flowchart of FIG. 9. Then, in step S61, the control device 40 cuts off the communication connections with the monitoring devices 30_2, 30_3, but maintains the communication connection with the monitoring device 30_1. The communication between the control device 40 and the monitoring device 30_1 is performed at a lower frequency than the communication among the plurality of monitoring devices 30_1, 30_2, 30_3 as described above.

[0129] The processes of steps S62 to S71 in the flowchart of FIG. 11 are the same as the processes of steps S42 to S51 in the flowchart of FIG. 9. And in step S72, when the control device 40 detects that the ignition switch has been turned on, it notifies the monitoring device 30_1 via the maintained communication connection that the ignition switch has been turned on. In response to this notification, the monitoring device 30_1 notifies the other monitoring devices 30_2 and 30_3 that the ignition switch has been turned on via the chain-type network among the monitoring devices 30_1, 30_2, and 30_3 shown in FIG. 10. Thereby, each of the monitoring devices 30_2 and 30_3 can grasp that it is necessary to change the form of the communication network to the star-type network for the operating state of the battery pack 20 shown in FIG. 8(a). And since the control device 40 becomes the communication master device of each of the monitoring devices 30_2 and 30_3, it executes an acceptance operation in step S73, and since each of the monitoring devices 30_2 and 30_3 becomes the communication slave device of the control device 40, it performs a connection request operation in steps S74 and S75. Then, in step S76, an operation for establishing a connection between the control device 40 and each of the monitoring devices 30_1, 30_2, and 30_3 is executed.

[0130] (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 construed to include all changes within the meaning and scope equivalent to the description of the claims.

[0131] The disclosure in the specification, drawings, etc. is not limited by the description in the claims. The disclosure in the specification, drawings, etc. encompasses 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 in the claims.

[0132] When an element or layer is referred to as "above", "connected to", "connected", or "coupled to", it may be directly above, connected, connected, or coupled to another element or layer, and there may be intervening elements or intervening layers. In contrast, when an element is referred to as "directly above", "directly connected to", "directly connected", 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 (for example, "between" versus "directly between", "adjacent" versus "directly adjacent", etc.). As used in this specification, the term "and / or" includes any combination and all combinations of one or more of the associated listed items.

[0133] Spatially relative terms such as "inside", "outside", "back", "below", "lower", "above", "higher", etc. are used herein to facilitate the 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 during use or operation in addition to the orientation depicted in the drawings. For example, if the device in the figure is turned over, an element described as "below" or "directly below" another element or feature will be oriented "above" the other element or feature. Therefore, the term "below" can encompass both upward and downward orientations. The device may be oriented in other directions (rotated 90 degrees or other orientations), and the spatially relative descriptors used in this specification are interpreted accordingly.

[0134] 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 executable by a computer.

[0135] For example, an example where the monitoring device 30 includes the microcomputer 34 is shown, but it is not limited thereto. A battery management system 60 configured such that 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 scheduling control of sensing and self-diagnosis by the monitoring IC 33, the wireless IC 35 may execute it, or the main microcomputer 45 of the control device 40 may execute it.

[0136] An example where the monitoring device 30 is arranged for each battery stack 21 is shown, but it is not limited thereto. 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.

[0137] An example where the battery pack 11 includes one control device 40 is shown, but it is not limited thereto. A plurality of control devices 40 may be included. An example where the monitoring device 30 includes one monitoring IC 33 is shown, but it is not limited thereto. 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.

[0138] 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 examples. 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 examples.

[0139] 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

[0140] 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 each monitor one of 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 from the operating state to the non-operating state and notifies the plurality of monitoring devices; In the non-operating state of the device to be monitored, a communication connection is formed between the plurality of monitoring devices such that one of the plurality of monitoring devices becomes a communication master device and another one becomes a communication slave device. The communication connection is formed such that each of the plurality of monitoring devices becomes a communication master device for other monitoring devices and also becomes a communication slave device for monitoring devices other than the monitoring device that becomes the communication master device. The plurality of monitoring devices communicate regularly via the formed communication connection; In the non-operating state of the device to be monitored, the control device disconnects the communication connection with the plurality of monitoring devices, or the control device becomes a communication master device and communicates with at least one of the plurality of monitoring devices that become communication slave devices at a lower frequency than the communication between the plurality of monitoring devices. A monitoring system.

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 and operates.

3. The monitoring system according to claim 1 or 2, wherein in the operating state of the device to be monitored, the control device performs wireless communication as a communication master device via a communication connection established individually with each of the plurality of monitoring devices that are communication slave devices.

4. At least one of the plurality of monitoring devices collects monitoring information of at least one other monitoring device via communication in the non-operating state of the device to be monitored, and when the device to be monitored is switched from the non-operating state to the operating state, provides the control device with the monitoring information of the other monitoring device collected together with its own monitoring information. The monitoring system according to any one of claims 1 to 3.

5. The device to be monitored is a battery pack composed of a plurality of battery stacks; The battery stack includes a plurality of battery cells; Each of the plurality of monitoring devices monitors the battery stack and monitors at least voltage values of the plurality of battery cells included in the battery stack. Since the voltage values of the plurality of battery cells are non-uniform, when each of the plurality of monitoring devices executes an equalization process for equalizing the voltage values of the plurality of battery cells in a non-operating state where the battery pack does not need to provide power, each of the plurality of monitoring devices terminates communication with other monitoring devices when the equalization process of the battery cells is completed, or communicates with other monitoring devices at a lower frequency than the communication before the completion of the equalization process of the battery cells. The monitoring system according to any one of claims 1 to 4.

6. The control device also detects a switch from the non-operating state to the operating state. In the non-operating state of the device under monitoring, when the control device disconnects the communication connection with the plurality of monitoring devices, at least one of the plurality of monitoring devices periodically transmits a connection request signal to the control device, and when the control device detects a switch from the non-operating state to the operating state, the control device starts communicating with at least one of the plurality of monitoring devices by responding to the connection request signal and notifies the switch from the non-operating state to the operating state. The monitoring system according to any one of claims 1 to 5.

7. In the non-operating state of the device under monitoring, a monitoring device that has received a notification of a switch from the non-operating state to the operating state from the control device notifies other monitoring devices of the switch from the non-operating state to the operating state via a communication connection between the plurality of monitoring devices. The monitoring system according to claim 6.

Images