Battery management system

Abstract

A battery management system in a vehicle includes a monitoring device provided in a case that houses a battery, and a control device provided in the case that acquires battery information from the monitoring device and executes a predetermined process. The control device stores, as learning data, in advance, frequency channels usable for transmitting and receiving data to and from each monitoring device that performs wireless communication and data related to an electric field intensity in the case. The control device determines a target frequency channel of frequency channel hopping based on the learning data.

Description

Technical Field

[0001] This invention relates generally to a battery management system. Background Technology

[0002] A comparative example (Japanese Patent No. 6514694) discloses a battery management system, which is incorporated herein by reference as an explanation of the technical elements of the present invention.

[0003] The battery management system described in the comparative example evaluates communication quality based on the results of data transmission / reception between the master and slave devices, and determines that the communication quality of the currently used frequency channel has deteriorated when the number of reception failures, etc., exceeds a threshold. Then, the frequency hopping mode is changed to use a frequency channel with good communication quality. In this way, because the frequency channel is changed based on the actual communication quality, many unreliable wireless communications occur. Given the above points and / or other points not mentioned, the battery management system needs further improvement. Summary of the Invention

[0004] The purpose of this invention is to provide a battery management system that can provide highly reliable wireless communication.

[0005] The battery management system disclosed here includes:

[0006] One or more monitoring devices are disposed within a housing of the vehicle battery and monitor battery information indicating battery status; and

[0007] A control device acquires battery information from the monitoring device and executes a predetermined process, wherein...

[0008] The control and monitoring devices (one acting as the master and the other as the slave) use frequency hopping to perform wireless communication, and

[0009] Main unit

[0010] Data related to the electric field strength within the housing is pre-stored as learning data for use in available frequency channels to send and receive data from each slave device performing wireless communication.

[0011] Based on this learning data, one or more target frequency channels are identified for frequency channel hopping.

[0012] The predetermined frequency channel is determined by performing frequency channel hopping, and

[0013] Based on the results of sending data to the slave device and receiving data from the slave device on a predetermined frequency channel, the communication quality is evaluated and accumulated into a communication record.

[0014] According to the disclosed battery management system, the master device has pre-stored learning data. This learning data is data related to the electric field strength within the housing for use in transmitting to / receiving data from the slave device, i.e., exchanging data with the slave device. The master device determines the target frequency channel for frequency hopping based on the pre-stored electric field strength within the housing. Therefore, a battery management system capable of providing highly reliable wireless communication can be provided.

[0015] The aspects disclosed in this specification employ different technical solutions to achieve their respective purposes. The reference numerals in parentheses described in the claims and this section exemplarily illustrate the correspondence with portions of the embodiments described later, and are not intended to limit the scope of the technology. The purposes, features, and advantages disclosed in this specification will become apparent from the following detailed description and accompanying drawings. Attached Figure Description

[0016] The objects, features, and advantages of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings, in which:

[0017] Figure 1 This is a schematic diagram showing a vehicle equipped with a battery pack;

[0018] Figure 2 This is a perspective view showing a schematic structure of the battery pack;

[0019] Figure 3 This is a plan view showing the assembled battery;

[0020] Figure 4 This is a block diagram illustrating the construction of a battery management system according to the first embodiment;

[0021] Figure 5 This is a schematic diagram illustrating an example of a communication sequence between a monitoring device and a control device;

[0022] Figure 6 This is a schematic diagram showing the electric field intensity distribution within the shell;

[0023] Figure 7 This is a flowchart illustrating an example of the process for determining a target frequency channel using learned data;

[0024] Figure 8 This is a schematic diagram illustrating an example of available frequency channels;

[0025] Figure 9 This is a schematic diagram illustrating a frequency hopping mode as an example of frequency channel frequency hopping;

[0026] Figure 10 This is a schematic diagram illustrating an example of thresholds set based on communication records and learning data for each frequency channel;

[0027] Figure 11 This is a schematic diagram illustrating a frequency hopping mode that takes into account unavailability;

[0028] Figure 12 This is a flowchart illustrating an example of a sharing process;

[0029] Figure 13 This is a timing diagram illustrating an example of data communication that includes shared information;

[0030] Figure 14 This is a flowchart illustrating an example of a target frequency channel determination process performed by a control device in a battery management system according to a second embodiment;

[0031] Figure 15 This is a schematic diagram illustrating an example of threshold settings based on communication records and learning data for each group;

[0032] Figure 16 This is a flowchart illustrating an example of a return process performed by a control device in a battery management system according to a third embodiment;

[0033] Figure 17 This is a timing diagram showing the execution timing of the target frequency channel determination process in the battery management system according to the fourth embodiment;

[0034] Figure 18 This is a schematic diagram illustrating an example of a communication sequence in a battery management system according to a fifth embodiment;

[0035] Figure 19 This is a flowchart illustrating an example of an update process performed by a control device in a battery management system according to the sixth embodiment; and

[0036] Figure 20 This is a block diagram illustrating another example of the construction of a battery management system. Detailed Implementation

[0037] Hereinafter, several embodiments are described with reference to the accompanying drawings. In each embodiment, the same reference numerals designate corresponding elements, thus, repeated descriptions may be omitted. In each embodiment, when only a portion of the construction is described, the remainder of the construction may be derived from corresponding portions of other embodiments. Furthermore, even if not explicitly shown, not only combinations of constructions explicitly shown in the description of the corresponding embodiments but also constructions of multiple embodiments can be partially combined, provided that there is no particular difficulty in combining them.

[0038] (First Embodiment)

[0039] First, based on Figure 1This describes a vehicle equipped with a battery management system according to this embodiment, and specifically describes the structure of the battery pack equipped with the battery management system. Figure 1 This is a schematic diagram showing the structure of a vehicle. The vehicle is an electric vehicle, such as an electric car or a hybrid vehicle.

[0040] <Vehicles>

[0041] like Figure 1 As shown, vehicle 10 includes battery pack (BAT) 11, PCU 12, MG 13, and ECU 14. PCU is an abbreviation for power control unit. MG is an abbreviation for electric generator. ECU is an abbreviation for electronic control unit.

[0042] Battery pack 11 includes assembled battery 20 (described later) and provides a DC voltage source that can be charged and discharged. Battery pack 11 supplies power to the electrical loads of vehicle 10. Battery pack 11 supplies power to MG 13 via PCU 12. Battery pack 11 is charged via PCU 12. Battery pack 11 may sometimes be referred to as the main battery.

[0043] For example, such as Figure 1 As shown, the battery pack 11 is located in the front compartment of the vehicle 10. The battery pack 11 can also be located in the rear compartment, under the seats, under the floor, etc. For example, in hybrid vehicles, the compartment where the engine is located may sometimes be referred to as the engine compartment or engine room.

[0044] PCU 12 performs bidirectional power conversion between battery pack 11 and MG 13 based on control signals from ECU 14. PCU 12 is sometimes referred to as a power converter. PCU 12 includes, for example, an inverter. The inverter converts DC voltage to AC voltage, for example, to three-phase AC voltage, and outputs the AC voltage to MG 13. The inverter converts the power generated by MG 13 back to DC voltage and outputs it to the converter. PCU 12 may include a converter. The converter is located in the power path between battery pack 11 and the inverter. The converter has the function of increasing and decreasing DC voltage.

[0045] MG 13 is an AC rotating motor, such as a three-phase AC synchronous motor, in which permanent magnets are embedded in the rotor. MG 13 serves as the driving power source for vehicle 10, i.e., an electric motor. MG 13 is driven by PCU 12 to generate rotational driving force. The driving force generated by MG 13 is transmitted to the drive wheels. MG 13 acts as a generator during vehicle 10 braking and performs regenerative power generation. The electricity generated by MG 13 is supplied to battery pack 11 via PCU 12 and stored in the assembled batteries 20 of battery pack 11.

[0046] ECU 14 is configured as a computer including a processor, memory, input / output interfaces, buses connecting them, etc. The processor is hardware used for arithmetic operations. A processor may include, for example, a CPU as its core. CPU is an abbreviation for Central Processing Unit. Memory is a non-volatile, substantial storage medium that non-volatilely stores or remembers programs and data that the computer can read; memory stores various programs executed by the processor.

[0047] For example, ECU 14 obtains information about the assembled battery 20 from battery pack 11 and controls PCU 12 to control the drive of MG 13 and the charging / discharging of battery pack 11. ECU 14 can obtain information about the assembled battery 20 from battery pack 11, such as voltage, temperature, current, SOC (State of Charge), and SOH (State of Health). ECU 14 can obtain battery information, such as the voltage, temperature, and current of the assembled battery 20, to calculate SOC and SOH. SOC is an abbreviation for State of Charge. SOH is an abbreviation for State of Health.

[0048] The processor of ECU 14 executes multiple instructions included in a PCU control program, for example, stored in memory. As a result, ECU 14 constructs multiple functional units for controlling PCU 12. In ECU 14, multiple functional units are constructed / provided by causing the processor to execute multiple instructions under the control of a program stored in memory. ECU 14 may be referred to as an EVECU.

[0049] <Battery Pack>

[0050] Next, refer to Figure 2 and 3 Describe a construction example of battery pack 11. Figure 2 This is a schematic perspective view showing the interior of battery pack 11. Figure 2 In the diagram, the shell is represented by a double-dotted line. Figure 3 This is a plan view showing the top surface of each battery pack.

[0051] like Figure 2 As shown, the battery pack 11 includes assembled batteries 20, multiple monitoring devices 30, a control device 40, and a housing 50. The housing 50 houses the other components constituting the battery pack 11, namely the assembled batteries 20, the monitoring devices 30, and the control device 40. The housing 50 is made of, for example, metal. The housing 50 may be made of resin, or may include both metal and resin portions.

[0052] In the following text, such as Figure 2 As shown, in the surface / face of the housing 50 having a basic rectangular parallelepiped shape, the mounting surface on the vehicle 10 has a long side arranged in the X direction and a short side arranged in the Y direction. Figure 2In the middle, the lower surface is the mounting surface. The vertical direction perpendicular to the mounting surface is called the Z direction. The X, Y, and Z directions are in a mutually orthogonal positional relationship. In this embodiment, the left-right direction of the vehicle 10 corresponds to the X direction, the front-rear direction corresponds to the Y direction, and the vertical direction corresponds to the Z direction. Figure 2 and 3 The setup is just an example; the battery pack 11 can be positioned in any orientation relative to the vehicle 10.

[0053] The assembled battery 20 has multiple battery packs 21 arranged side-by-side in the X direction. Battery packs 21 can also be referred to as battery blocks or battery modules. The assembled battery 20 is constructed by connecting multiple battery packs 21 in series. Each battery pack 21 has multiple battery cells 22. The battery pack 21 has multiple battery cells 22 connected in series. The battery pack 21 of this embodiment is constructed by connecting multiple battery cells 22 arranged side-by-side in the Y direction in series. The assembled battery 20 is provided with the aforementioned DC voltage source. The assembled battery 20, battery packs 21, and battery cells 22 correspond to one battery.

[0054] Battery cell 22 is a secondary battery that generates an electric voltage through a chemical reaction. For example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery can be used as the secondary battery. A lithium-ion secondary battery is a secondary battery that uses lithium as the charging carrier. In addition to ordinary lithium-ion secondary batteries in which the electrolyte is liquid, so-called all-solid-state batteries using solid electrolytes can also be included.

[0055] On the upper surface of each battery pack 21, linear bus units 23 are disposed at both ends in the X direction. That is, a pair of bus units 23 are disposed in each battery pack 21. The bus units 23 are electrically connected to multiple battery cells 22. Figure 3 As shown, each battery cell 22 is formed in a flat shape and is laminated / stacked such that its side surfaces overlap (stack) each other in the Y direction. The battery cell 22 has a positive terminal 25 and a negative terminal 26 protruding in the Z direction (representing the upward direction) at both ends in the X direction. The battery cell 22 is laminated such that the positive terminal 25 and the negative terminal 26 are arranged alternately in the Y direction.

[0056] Each bus unit 23 has multiple busbars 24 electrically connecting the positive terminal 25 and the negative terminal 26, and a busbar cover 27 covering the multiple busbars 24. The busbars 24 are plates made of a highly conductive metal (e.g., copper). The busbars 24 electrically connect the positive terminals 25 and negative terminals 26 of adjacent battery cells 22 in the Y direction. As a result, in each battery pack 21, multiple battery cells 22 are connected in series. In each battery pack 21, the positive terminal 25 of the battery cell 22 located at one end along the Y direction is connected to a predetermined positive electrode connection, while the negative terminal 26 of the battery cell 22 located at the other end is connected to a predetermined negative electrode connection.

[0057] Busbar cover 27 is formed using an electrically insulating material such as resin. Busbar cover 27 is linearly arranged along the Y direction from one end of battery pack 21 to the other to cover the plurality of busbars 24.

[0058] Monitoring device 30 is provided to each of the plurality of battery packs 21. For example... Figure 2 As shown, a monitoring device 30 is disposed between a pair of bus units 23 in each battery pack 21. The monitoring device 30 is fixed to the bus unit 23 with screws or the like. The monitoring device 30 has a circuit board (not shown) and is fixed such that the thickness direction of the circuit board is substantially aligned with the Z direction. As described below, the monitoring device 30 is configured to enable wireless communication with the control device 40. The antenna 37, included in the monitoring device 30 and described later, is configured not to overlap with the bus unit 23 in the Z direction, that is, not to protrude from the bus unit 23 in the Z direction.

[0059] The control device 40 is attached to the outer surface of the battery pack 21 at one end in the X direction. The control device 40 is configured to communicate wirelessly with each monitoring device 30. The antenna 42 (described later) included in the control device 40 is positioned at 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 configured to protrude from the bus unit 23 in the Z direction.

[0060] In battery pack 11, monitoring device 30 and control device 40 provide battery management system 60, which will be described later. That is, battery pack 11 includes battery management system 60.

[0061] Battery Management System

[0062] Next, refer to Figure 4 Describe a schematic structure of a battery management system. Figure 4 This is a block diagram showing the structure of the battery management system.

[0063] like Figure 4As shown, the battery management system 60 includes multiple management units (SBMs) 30 and a control unit (ECU) 40. The control unit 40 may be referred to as a battery ECU or BMU. BMU is an abbreviation for Battery Management Unit. The battery management system 60 is a system that manages the battery using wireless communication. In the battery management system 60, wireless communication is performed between one control unit 40 and multiple monitoring units 30. The wireless communication in this embodiment uses a frequency band in short-range (near-field) communication, such as the 2.4 GHz band or the 5 GHz band.

[0064] <Monitoring Device>

[0065] First, the monitoring device 30 is described. Since the construction of the monitoring device 30 is almost identical in all devices 30, the common construction is described below. The monitoring device 30 includes a power supply circuit (PSC) 31, a multiplexer (MUX) 32, a monitoring IC (MIC) 33, a microcomputer (MC) 34, a wireless IC (WIC) 35, a front-end circuit (FE) 36, and an antenna (ANT) 37. Communication between these components in the monitoring device 30 is achieved via wires.

[0066] Power supply circuit 31 uses the voltage supplied from battery pack 21 to generate operating power for other circuit elements included in monitoring device 30. In this embodiment, power supply circuit 31 includes power supply circuits 311, 312, and 313. Power supply circuit 311 uses the voltage supplied from battery pack 21 to generate a predetermined voltage and supplies it to monitoring IC 33. Power supply circuit 312 uses the voltage generated by power supply circuit 311 to generate a predetermined voltage and supplies it to microcomputer 34. Power supply circuit 313 uses the voltage generated by power supply circuit 311 to generate a predetermined voltage and supplies it to wireless IC 35.

[0067] Multiplexer 32 is a selection circuit whose input includes detection signals from multiple sensors 70 in the battery pack 11, and outputs the detection signals as a single signal. Multiplexer 32 selects (i.e., switches) the inputs according to a selection signal from monitoring IC 33 and outputs them as a single signal. Sensors 70 include sensors that detect physical quantities of each battery cell 22, sensors for determining / identifying which of the multiple battery cells 22 is currently involved, etc. Physical quantity detection sensors include, for example, voltage sensors, temperature sensors, current sensors, etc.

[0068] The monitoring IC 33 senses (i.e., acquires) battery information, such as battery voltage, battery temperature, and battery status, via multiplexer 32, and sends the battery information to microcomputer 34. The monitoring IC 33 may sometimes be referred to as a cell monitoring circuit (CSC). CSC is an abbreviation for cell monitoring circuit. The monitoring IC 33 may have the following functions: (i) performing fault diagnosis on the circuit portion of the monitoring device 30 including IC 33, and (ii) sending the diagnostic results along with the battery information as monitoring data. When the monitoring IC 33 receives data requesting the acquisition of battery information sent from microcomputer 34, the monitoring IC 33 senses (i.e., picks up) the battery information via multiplexer 32 and sends monitoring data, including at least the battery information, to microcomputer 34. The monitoring IC 33 corresponds to a monitoring unit.

[0069] A microcomputer 34 is a microcomputer having a CPU as a processor, ROM and RAM as memory, input / output interfaces, and buses for connecting them. The CPU constructs multiple functional units by executing various programs stored in ROM while using the temporary storage function of RAM. ROM is an abbreviation for Read-Only Memory. RAM is an abbreviation for Random Access Memory.

[0070] The microcomputer 34 controls the sensing and self-diagnostic schedule via the monitoring IC 33. The microcomputer 34 receives monitoring data from the monitoring IC 33 and transmits it to the wireless IC 35. The microcomputer 34 sends data requesting battery information to the monitoring IC 33. For example, when the microcomputer 34 in this embodiment receives data requesting battery information from the wireless IC 35, it sends the data requesting battery information to the monitoring IC 33.

[0071] The wireless IC 35 includes RF circuitry for wirelessly transmitting and receiving data and a microcomputer (not shown). The wireless IC 35 has a transmission function that modulates transmitted data and oscillates at the frequency of the RF signal. The wireless IC 35 also has a reception function for demodulating received data. RF is an abbreviation for radio frequency.

[0072] The wireless IC 35 modulates data including battery information transmitted from the microcomputer 34 and transmits it to the control device 40 via the front-end circuitry 36 and antenna 37. The wireless IC 35 adds data necessary for wireless communication (e.g., communication control information) to the transmitted data including the battery information and then transmits the data. Data necessary for wireless communication includes, for example, identifiers (IDs) and error detection codes. The wireless IC 35 controls the data size, communication format, scheduling, error detection, etc., of the communication between the SBM 30 and the control device 40.

[0073] The wireless IC 35 receives data transmitted from the control device 40 via the antenna 37 and the front-end circuitry 36, and demodulates the data. For example, when the wireless IC 35 receives data including a request to acquire and transmit battery information, the wireless IC 35 acquires monitoring data including battery information via the monitoring IC 33 and sends the monitoring data as a response to the request to the control device 40. The wireless IC 35 corresponds to a wireless circuit unit.

[0074] The front-end circuit 36 ​​has a matching circuit for impedance matching between the wireless IC 35 and the antenna 37, and a filtering circuit for removing unwanted frequency components.

[0075] Antenna 37 converts the RF signal, which is an electrical signal, into radio waves and radiates them into space. Antenna 37 receives radio waves propagating in space and converts them into electrical signals.

[0076] <Control Device>

[0077] Next, refer to Figure 4 The control device 40 is described. 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 each of these components in the control device 40 is performed via wires.

[0078] Power supply circuit 41 uses the voltage supplied from battery (BAT) 15 to generate operating power for operating other circuit elements included in control device 40. Battery 15 is a DC voltage source installed on vehicle 10 and is different from battery pack 11. Battery 15 may sometimes be referred to as an auxiliary battery because it supplies power to auxiliary devices of vehicle 10. In this embodiment, power supply circuit 41 includes power supply circuits 411 and 412. Power supply circuit 411 uses the voltage supplied from battery 15 to generate a predetermined voltage and supplies this voltage to main microcomputer 45 and sub-microcomputer 46. For simplicity, the electrical connection between power supply circuit 411 and sub-microcomputer 46 is omitted. Power supply circuit 412 uses the voltage generated by power supply circuit 411 to generate a predetermined voltage and supplies it to wireless IC 44.

[0079] Antenna 42 converts the RF signal, which is an electrical signal, into radio waves and radiates them into space. Antenna 42 receives the radio waves propagating in space and converts them into electrical signals.

[0080] The front-end circuit 43 includes a matching circuit for impedance matching between the wireless IC 44 and the antenna 42, and a filtering circuit for removing unwanted frequency components.

[0081] Wireless IC 44 has RF circuitry for wirelessly transmitting and receiving data and a microcomputer. Like Wireless IC 35, Wireless IC 44 has both transmitting and receiving functions. Wireless IC 44 receives data transmitted from monitoring device 30 via antenna 42 and front-end circuitry 43, and demodulates the data. It then transmits monitoring data, including battery information, to main microcomputer 45. Wireless IC 44 receives data transmitted from main microcomputer 45, modulates it, and transmits it to monitoring device 30 via front-end circuitry 43 and antenna 42. Wireless IC 44 adds data required for wireless communication (e.g., communication control information) to the transmitted data and transmits the data. Data required for wireless communication includes, for example, identifiers (IDs) and error detection codes. Wireless IC 44 controls the data size, communication format, scheduling, error detection, etc., of communication between monitoring device 30 and control device 40.

[0082] The wireless IC 44 has a learning data storage unit (DS) 442. The learning data storage unit 442 is built into a non-volatile memory, such as that of a microcomputer 441. The learning data storage unit 442 may also be built into a non-volatile storage medium disposed separately from the memory of the microcomputer 441 within the control device 40. The learning data storage unit 442 stores learning data. This learning data is data associated with the electric field strength in the housing 50, used for available frequency channels that can be used to send and receive data from the monitoring device 30. The learning data storage unit 442 stores learning data for each monitoring device 30 that wirelessly communicates with the ECU 40. The wireless IC 44 determines the frequency channel for frequency hopping based on the learning data. The learning data and the determination of the frequency channel using the learning data will be described later.

[0083] The main microcomputer 45 is a microcomputer having a CPU, ROM, RAM, input / output interfaces, buses connecting them, etc. The ROM stores various programs executed by the CPU. The main microcomputer 45 generates a command requesting the monitoring device 30 to process monitoring data including battery information, and sends transmission data including the command to the wireless IC 44. In this embodiment, the main microcomputer 45 generates a command requesting the acquisition and transmission of monitoring data including battery information. The request in this document may also be referred to as an instruction.

[0084] The main microcomputer 45 receives monitoring data including battery information transmitted from the wireless IC 44 and performs predetermined processing based on the monitoring data. For example, the main microcomputer 45 performs the process of sending the acquired battery information to the ECU 14. The main microcomputer 45 can calculate the SOC and / or SOH based on the battery information and can send the battery information including the calculated SOC and SOH to the ECU 14. The main microcomputer 45 can perform equalization processing based on the battery information to equalize the voltage of each battery cell 22. The main microcomputer 45 can acquire the IG signal of the vehicle 10 and perform the above processing according to the driving state of the vehicle 10. The main microcomputer 45 can perform processing to detect abnormalities in the battery cells 22 based on the battery information, or it can send abnormality detection information to the ECU 14.

[0085] The sub-microcomputer 46 is a microcomputer with a CPU, ROM, RAM, input / output interfaces, and a bus connecting them. The ROM stores various programs executed by the CPU. The sub-microcomputer 46 performs monitoring processing for components / data in the monitoring and control device 40. For example, the sub-microcomputer 46 can monitor the data exchanged between the wireless IC 44 and the main microcomputer 45. The sub-microcomputer 46 can monitor the status of the main microcomputer 45. The sub-microcomputer 46 can monitor the status of the wireless IC 44.

[0086] Wireless Communication

[0087] Next, refer to Figure 5 Describe the wireless communication between the monitoring device 30 and the control device 40. Figure 5 This is a diagram illustrating an example of the communication sequence between the monitoring device 30 and the control device 40. Figure 5 Wireless communication between one of the monitoring devices 30 and the control device 40 is described. Figure 5 In the display, monitoring IC 33 is displayed as MIC33, wireless IC 35 is displayed as WIC35, and control device 40 is displayed as ECU40.

[0088] like Figure 5 As shown, firstly, the wireless IC 35 of the monitoring device 30 and the control device 40 perform a startup process such as establishing a connection (step S10). For example, the startup time could be the time when operating power is provided. In a configuration where power is continuously supplied from the battery pack 21 and the battery 15, the vehicle 10 is started during the manufacturing process or after parts are replaced at a repair shop. During startup, a startup signal, such as an IG signal, can be provided. For example, it is activated when the user switches the IG signal from off to on.

[0089] During startup, startup procedures are executed separately for communication between the control device 40 and each of the monitoring devices 30 wirelessly connected to the control device 40. The startup procedures include, for example, (i) a connection establishment procedure for establishing a wireless communication connection and (ii) a pairing procedure for exchanging unique information for encrypted communication. The startup procedures include a sharing procedure for sharing initial information about frequency channel hopping. The initial information includes, for example, a frequency hopping mode or frequency hopping function.

[0090] When step S10 is completed, the monitoring device 30 and the control device 40 periodically perform data communication. For example... Figure 5 As shown, the control device 40 sends transmission data including (i) an acquisition request and (ii) a transmission request (i.e., request data) including monitoring data containing battery information to the monitoring device 30 (step S20).

[0091] When the wireless IC 35 of the monitoring device 30 receives the requested data, it sends a request to the monitoring IC 33 to acquire monitoring data including battery information (step S21). In this embodiment, the wireless IC 35 sends the acquisition request to the monitoring IC 33 via the microcomputer 34.

[0092] Upon receiving an acquisition request, the monitoring IC 33 performs sensing (step S22). The monitoring IC 33 performs sensing via the multiplexer 32 and acquires battery information for each battery cell 22. Furthermore, the monitoring IC 33 performs circuit fault diagnosis.

[0093] Next, the monitoring IC 33 sends monitoring data, including battery information, to the wireless IC 35 (step S23). In this embodiment, monitoring data, including fault diagnosis results, is sent together with the battery information. The monitoring IC 33 sends data to the wireless IC 35 via the microcomputer 34.

[0094] When the wireless IC 35 receives the monitoring data acquired by the monitoring IC 33, the wireless IC 35 sends transmission data, i.e., response data, including the monitoring data to the control device 40 (step S24).

[0095] Upon receiving response data, the control device 40 executes a predetermined process based on the monitoring data (step S25). In this embodiment, the control device 40 that executes the request process corresponds to the master device, and the monitoring device 30 that executes the response process corresponds to the slave device.

[0096] The process described in steps S20 to S25 is performed between the control device 40 and each monitoring device 30. The battery management system 60 periodically performs the process in steps S20 to S25.

[0097] The control device 40 determines the frequency channel to be used by performing frequency channel hopping for each data transmission / reception cycle, and transmits request data and receives response data on the determined frequency channel (frequency). The control device 40 performs frequency channel hopping based on initial information until unavailable channels / multiple channels are identified. When an unavailable channel is identified, the control device 40 performs frequency channel hopping taking one or more unavailable channels into account.

[0098] Similarly, monitoring device 30 also determines the frequency channel to be used by performing frequency channel hopping for each transmit / receive cycle, and receives request data and transmits response data on the determined frequency channel (frequency). Monitoring device 30 performs frequency channel hopping based on information shared with control device 40. Therefore, monitoring device 30 and control device 40 can use the same frequency channel to transmit and receive data. Control device 40 and monitoring device 30 switch the target frequency channel for each transmit / receive cycle by performing frequency channel hopping.

[0099] <Learning Data>

[0100] Next, refer to Figure 6 Describe the learning data. Figure 6 This is a diagram showing the distribution of electric field intensity in the housing 50 of the battery pack 11. Figure 6 The results of electromagnetic field simulations at predetermined frequencies and timings are shown. Figure 6 In this example, the control device 40 (wave source) is basically located at the center of the metal housing 50.

[0101] When radio waves of a predetermined frequency are radiated from the control device 40, due to interference between the emitted and reflected waves, portions with high electric field strength and portions with low electric field strength are generated within the housing 50, such as... Figure 6 As shown. When the housing 50 is made of metal, it becomes more noticeable, but so does a housing made of resin. Reflected waves are generated by the reflection of emitted waves by the metal components constituting the battery pack 11, such as reflections from the housing 50, reflections from the wiring harness (not shown), etc. Furthermore, when the housing 50 is made of resin, reflections of emitted waves may be caused by metal components / body present around the battery pack 11 in the vehicle 10, such as reflections from the metal vehicle frame.

[0102] Furthermore, within an enclosed space such as housing 50, even if the phase changes, there are portions with generally high electric field strength and portions with generally low electric field strength. In particular, when housing 50 is made of metal, its shielding function makes it clearly visible. The positions of monitoring device 30 and control device 40 are fixed within housing 50 and ultimately within vehicle 10. That is, the positions of devices 30 and 40 are fixed. In vehicles of the same type 10, the positions of monitoring device 30 and control device 40 are shared (identical).

[0103] In this embodiment, the control device 40 has pre-acquired data related to the electric field strength in the housing 50 as learning data. For example, prior to transporting the vehicle 10, particularly during the manufacturing of the battery pack 11, the learning data is written into the learning data storage unit 442 of the wireless IC 44. The learning data can be obtained, for example, through measurements on the vehicle 10 during the prototyping phase, or through electromagnetic field simulation. As described above, since the electric field strength varies with phase, it is preferable to use (i) data related to the average electric field strength over a predetermined time period (duration), or (ii) data related to the maximum electric field strength over a predetermined time period (duration).

[0104] The learning data includes at least data related to the electric field strength at the location of the control device 40 and data related to the electric field strength at the location of each monitoring device 30. The locations of the monitoring devices 30 and the control device 40 are preferably the locations of antennas 37 and 42, but can be slightly offset from the locations of antennas 37 and 42. The learning data can be data related to the electric field strength at grid cells defining the location relative to the housing 50. In this case, the locations and coordinates of the monitoring devices 30 and the control devices 40 can be linked. The data related to the electric field strength can be the electric field strength itself, i.e., the average or maximum value of the aforementioned electric field strength. Alternatively, related values ​​other than the electric field strength itself can be used. For example, the data can be data with electric field strength stratified by level.

[0105] For example, the learning data includes electric field strength-related data for each frequency channel used for data communication between the control device 40 and the monitoring device 30. The learning data may include data for some available frequency channels. The learning data includes electric field strength-related data for all monitoring devices 30 used for wireless communication with the control device 40. The learning data shows the relationship between frequency channels (frequency) and electric field strength in the control device 40 and the monitoring device 30. Hereinafter, the high electric field strength and low electric field strength of the control device 40 and the monitoring device 30 may simply be referred to as high electric field strength and low electric field strength.

[0106] <Determine the target channel>

[0107] Next, refer to Figures 7 to 11 The process of determining the channel used for communication (i.e., the target frequency channel using the learned data) is described. The determination process is performed by the wireless IC 44, which is the master control unit 40. The control unit 40 determines the target frequency channel for frequency hopping. Hereinafter, the frequency channel may be designated as "ch".

[0108] Figure 7 An example of available frequency channels is shown. Available channels are frequency channels allocated for data communication among multiple frequency channels. For example... Figure 7 As shown, available frequency channels for data transmission / reception (data communication) between a monitoring device 30 and a control device 40 are predetermined.

[0109] For example, in this embodiment, a total of 10 channels, from ch1 to ch10, are available. The frequency channels have predetermined frequency widths (bandwidths), and their frequencies are different from each other. Figure 7 As shown, ch1 has the lowest frequency, and ch10 has the highest frequency. The number of frequency channels available for transmitting and receiving data can be greater than or less than 10. The monitoring device 30 and the control device 40 can share information about available frequency channels, such as information that can be used as initial information, or they can have information about available frequency channels that they can share in advance.

[0110] Figure 8 An example of a target frequency channel determination process performed by the wireless IC 44 of the control device 40 is shown. First, the wireless IC 44 of the control device 40 performs frequency channel hopping to perform data communication with a monitoring device 30 and determines the frequency channel to be used in the current transmit / receive cycle (step S100) (i.e., the communication at this time). As described above, the control device 40 performs frequency channel hopping for each data transmit / receive cycle.

[0111] The frequency channel hopping method is not particularly limited. As an example, the control device 40 of this embodiment determines the frequency channel (i.e., the target frequency channel) based on the frequency channel hopping mode. Hereinafter, the frequency channel hopping mode may simply be referred to as the hopping mode. Alternatively, a predetermined function may be used to determine the frequency channel to be used. For example, the hopping mode and the function are included in the initial information described above.

[0112] Figure 9 An example of frequency hopping mode is shown. Figure 9The frequency hopping mode shown is the mode used for initial information sharing. That is, the frequency hopping mode before considering unavailable channels. In this embodiment, the frequency channel "used" (during frequency hopping) is switched in the order ch1→ch4→ch7→ch10→ch3→ch6→ch9→ch2→ch5→ch8→ch1. As mentioned above, the process of shifting / hopping the frequency channel a predetermined number of times can also be performed using a function. For example, ch1 is used to perform the first data communication after the startup process. Here, as an example, it is assumed that ch4 is determined to be the frequency channel to be used.

[0113] After executing step S100, the control device 40 performs a transmit / receive procedure on the determined frequency channel (step S110). Frequency channel hopping and the transmit / receive procedure correspond to... Figure 5 The diagram illustrates the sending of request data and the receiving of response data. Before executing the sending / receiving process, the monitoring device 30 also determines the frequency channel to be used based on the frequency hopping mode shared with the control device 40. For example, while the control device 40 determines the sending / receiving cycle of ch4, the monitoring device also determines ch4.

[0114] After performing step S110, the control device 40 evaluates the communication quality (step S120) and accumulates the communication quality into a communication record (step S130). The control device 40 evaluates the communication quality performed at this time (i.e., in the current transmission / reception cycle) based on the transmission / reception results in step S110. The control device 40 evaluates whether the communication quality is normal or degraded. The control device 40 accumulates the communication evaluation results for each frequency channel into a communication record.

[0115] The control device 40 evaluates communication quality based on information, for example, regarding the reception status of response data (i.e., response signals). When, for example, response data cannot be received, the control device 40 can assess communication quality as degraded. When the control device 40 detects a communication error through a check performed during reception (i.e., a check using an error detection code), it can assess communication quality as degraded even though data has been received. For example, when a retransmission process is required, the control device 40 can assess communication quality as degraded. That is, when communication is not established, it can be assessed as degraded communication quality. For example, when the received signal strength (RSSI) is below a predetermined value, the control device 40 can assess communication quality as degraded. RSSI is an abbreviation for Received Signal Strength Indicator. When communication evaluation criteria are met, the control device 40 assesses communication quality as having normal quality.

[0116] The control device 40 can obtain information about the reception status of request data (i.e., request signal) from the monitoring device 30 as part of the communication data used to evaluate communication quality. As the master device, the control device 40 evaluates the communication quality based on the information about the reception status of the request data and / or the information about the reception status of the response data, and accumulates the evaluation into a communication record.

[0117] Figure 10 The communication records for each frequency channel are shown. Figure 10 In this context, for clarity, the communication quality degradation results in the communication log are shaded. In this way, each time step S130 is executed, the control device 40 accumulates either the evaluation record of normal communication quality or the evaluation record of communication quality degradation as a communication log. In this way, the communication log for the frequency channel actually used is increased by one record.

[0118] After executing step S130, the control device 40 determines whether the number of communication records of the frequency channel actually used at this time (e.g., in the current cycle) has exceeded the reference number ST (step S140).

[0119] As described above, the signal phase changes. Therefore, in step S160, after the accumulation of communication records within a 360-degree phase range, or more preferably after the accumulation of multiple phase changes within a 360-degree range, unavailability can preferably be determined. With this in mind, in this embodiment, the reference number ST is set in the range of 1000 to tens of thousands. The reference number ST in this embodiment is a predetermined value (i.e., a fixed value). The reference number ST is pre-stored in, for example, the memory of the microcomputer 441.

[0120] When it is determined in step S140 that the number of communication records is equal to or less than the reference number ST, the control device 40 terminates the series of processes. The control device 40 maintains the target frequency channel currently set for frequency channel hopping.

[0121] When it is determined in step S140 that the number of communication records exceeds the baseline number ST, the control device 40 sets a threshold TH based on the learning data (step S150). The control device 40 sets the threshold TH for the frequency channels used in the transmit / receive processing performed in step S110. For example... Figure 10As shown by the dashed lines, the threshold TH is set individually / differently for each frequency channel based on the learning data. In this embodiment, when ch4 is used, the electric field strength in the control device 40 and the monitoring device 30 is lower than the electric field strength when other channels 1-3 and 5-10 are used. Therefore, the control device 40 sets the threshold TH of ch4 to a value lower than the threshold TH of other channels 1-3 and 5-10. That is, the threshold (TH) of ch4 is set such that ch4 can be easily determined to be unavailable.

[0122] After executing step S150, control device 40 performs an unavailability determination of the frequency channel used for communication at this time (e.g., in the current cycle) (step S160). Control device 40 determines whether the channel is available for the next and subsequent times by comparing (i) values ​​related to communication quality degradation in the communication records of the frequency channel used for communication with (ii) a threshold TH. Values ​​related to communication quality in the communication records are, for example, the ratio of communication quality degradation records in the communication records. Alternatively, the number of communication quality degradation records can be used instead of the ratio.

[0123] In step S160, when the correlation value of communication quality degradation is equal to or less than the threshold TH, the control device 40 determines that there is no problem using the frequency channel currently used for communication for the next and subsequent communications, and ends the series of processes. That is, the control device 40 maintains the frequency channel of the target frequency channel currently set for frequency channel hopping (i.e., keeps it unchanged).

[0124] When the correlation value of communication quality degradation in step S160 exceeds the threshold TH, the control device 40 determines that the frequency channel used for communication at this time cannot be used from the next and subsequent times, and sets it as an unavailable channel. For example, in Figure 10 In this case, the communication quality degradation rate of channel 4 exceeds the threshold TH. In this situation, the control device 40 determines that channel 4 is unavailable and sets it as an unavailable channel.

[0125] When it is determined that a channel is unavailable, the control device 40 determines the target frequency channel (step S170) and terminates the series of processes. The control device 40 determines the target frequency channel by excluding unavailable channels from the target frequency channels of the frequency channel hopping.

[0126] Figure 11An example of a frequency hopping mode considering unavailable channels is shown. Control device 40, for example, excludes ch4 from the frequency hopping mode as an unavailable channel. When frequency channel hopping is performed in a cycle following the ch1 transmit / receive cycle, the frequency channel to be used is switched to ch7. The unuse of unavailable channels can be achieved by performing frequency channel hopping again when selecting an unavailable channel, that is, by not excluding it from the frequency hopping mode.

[0127] After the above-described startup process is completed, the control device 40 repeats steps S100 to S170. The control device 40 performs a target frequency channel determination process when sending data to and receiving data from each monitoring device 30.

[0128] <Shared Process>

[0129] Next, refer to Figure 12 and 13 Description of information sharing with monitoring device 30 as a slave device. Figure 12 This is a flowchart illustrating an example of a shared process performed by control device 40. Figure 13 This is a timing diagram illustrating an example of data communication including channel information.

[0130] The control device 40 executes the process triggered by the above-described step S170. Figure 12 The process is shown. (As shown) Figure 12 As shown, the wireless IC 44 of the control device 40 sends data including channel information to the monitoring device 30 (step S200). The channel information is, for example, information about a frequency channel that has been determined to be an unusable channel. For instance, the channel information could be information about a target frequency channel after excluding unusable channels.

[0131] After executing step S200, the control device 40 determines whether a response signal to the transmission signal of step S200 has been received within a predetermined time after the transmission process of step S200 (step S210). When a response signal is received, the series of processes ends. When no response signal is received, the process of step S200 is executed again.

[0132] Figure 13 An example of the control device 40 sending / receiving data to each of the three monitoring devices 30 is shown; specifically, the three monitoring devices 30 are SBM1, SBM2, and SBM3. Figure 13An example is shown where a frequency channel with SBM2 is determined to be unavailable. Tx represents data transmission, and Rx represents data reception. SBM1(D), SBM2(D), and SBM3(D) represent the transmission / reception of requests and responses to monitoring data. SBM2(CI) represents the transmission and reception of data including channel information (CI).

[0133] After performing data transmission / reception using SBM2, control device 40 continuously transmits / receives data including channel information to / from SBM2. Control device 40 shares channel information with SBM2 before communicating with SBM3. The transmission / reception of channel information can be performed in SBM2 before a frequency channel previously determined to be unavailable is reused. For example, in... Figure 9 In the frequency hopping mode shown, unavailability information on ch4 can be sent after data is transmitted / received using ch9. In this case, channel information can be shared with SBM2 using ch9. The channel information is about frequency hopping on the frequency channel to be shared later and is different from the initial information.

[0134] <Overview of the First Embodiment>

[0135] As described above, the monitoring device 30 and the control device 40 are fixed within the housing 50, thus securing them to the vehicle 10. When radio waves of a predetermined frequency (i.e., a predetermined channel) are radiated from the control device 40, which serves as the main device, portions with high electric field strength and portions with low electric field strength are generated within the housing 50 due to interference between the transmitted and reflected waves. Even within an enclosed space such as the housing 50, portions with generally high electric field strength and portions with generally low electric field strength exist, even if the phase changes. When the electric field strength in the monitoring device 30 and the control device 40 is low, communication quality is more likely to deteriorate compared to a high electric field strength situation, leading to communication failures or deterioration of the received signal. In other words, in the positional relationship between the monitoring device 30 and the control device 40, there exists a frequency channel (frequency) where communication quality may deteriorate and a frequency channel where communication quality cannot deteriorate.

[0136] The control device 40 of this embodiment has data related to the electric field strength in the housing 50 as pre-learning data. The learning data is data related to the electric field strength in the housing 50 for an available frequency channel, which can be used for data transmission / reception with the monitoring device 30, which is a slave device. Based on the data related to the electric field strength, the control device 40 excludes frequency channels whose communication quality may deteriorate from the target frequency channels for frequency channel hopping. That is, frequency channels whose communication quality is unlikely to deteriorate are determined as the target frequency channels for frequency channel hopping. As a result, a battery management system 60 capable of highly reliable wireless communication can be provided. Therefore, the occurrence of communication failures can be suppressed. That is, the loss of monitoring data such as battery information can be suppressed.

[0137] In the case of wireless communication, the communication speed is slower than wired communication, and the communication frequency is typically lower. Therefore, if an anomaly occurs in at least one physical quantity such as voltage, or if fault diagnosis information detects an anomaly, or if monitoring data is lacking, the value may change abruptly. If this value changes abruptly, control will change abruptly, posing a risk to operability, even if there may be no safety issues. On the other hand, according to this embodiment, the lack of monitoring data indicating anomalies can be suppressed. Therefore, the impact on operability can be suppressed.

[0138] Furthermore, by suppressing the lack of monitoring data, it may be possible to accurately estimate factors estimated from the accumulation of monitoring data (e.g., the accumulation of battery damage). Additionally, anomalies can be detected by checking for the number of times a threshold is exceeded. Similarly, in this case, suppressing the loss of monitoring data can accelerate the timing of anomaly detection.

[0139] The electric field strength is also affected by factors other than the initial deterministic factors (initial factors), such as the aforementioned settings and frequency channel (frequency). The electric field strength within housing 50 can be altered by variable factors (i.e., unstable factors), such as temperature, humidity, foreign objects, and vibrations in the operating environment. For example, when the temperature increases, the electric field strength decreases compared to a lower temperature. When humidity increases, the electric field strength decreases due to the influence of moisture in the air. The electric field strength can also decrease due to foreign objects such as dust. Furthermore, the electric field strength changes when the position of a metallic object, such as a wire harness, moves due to vibration. The electric field strength also changes when the propagation path of radio waves moves due to vibration.

[0140] The control device 40 of this embodiment evaluates communication quality based on the results of transmitting and receiving data in a predetermined frequency channel, and accumulates the evaluation into a communication record. Then, when a value related to communication quality degradation in the communication record exceeds a threshold TH, the predetermined frequency channel is determined to be unusable and excluded from the target frequency channel. In this way, the unusability of a particular channel is determined by using values ​​based on actual transmission / reception results (specifically, values ​​related to communication quality degradation in the communication record). Therefore, this system allows the influence of variable factors such as temperature and vibration to be taken into account (e.g., reflected).

[0141] Furthermore, the control device 40 sets a threshold TH for each frequency channel based on the learned data. That is, the threshold TH is set individually for each frequency channel based on the electric field strength. For example, the threshold TH for a frequency channel with a low electric field strength is made more stringent than the threshold TH for a frequency channel with a high electric field strength. In this embodiment, the effects of initial and variable factors are considered, thereby further improving the reliability of wireless communication.

[0142] If a threshold TH is common (i.e., shared) across available frequency channels, communication failures may occur unnecessarily due to the use of a common threshold TH across different channels. According to this embodiment, since different threshold THs are set for each frequency channel taking into account the influence of initial factors, the threshold TH is quickly reached / satisfied for frequency channels with low electric field strength. Therefore, the number of communication failures can be reduced, and ultimately, the loss of battery information can be suppressed.

[0143] <Edit>

[0144] An example is shown where the reference number ST used in step S140 is set to a fixed value, but the invention is not limited to this example. The reference number ST can also be set for each frequency channel based on learning data. That is, the reference number ST of one or more frequency channels with low electric field strength in the monitoring device 30 and control device 40 can be less than the reference number ST of one or more frequency channels with high electric field strength.

[0145] Although not specifically mentioned, Figure 12 The communication quality of the sending / receiving results of the shared process shown can also be evaluated and accumulated as a communication record.

[0146] An example is shown where frequency channels determined to be unusable are excluded and the next frequency channel in the frequency hopping mode is used, but the invention is not limited to this example. After excluding frequency channels determined to be unusable and using predetermined frequency channels that do not follow the initial rules, the initial frequency hopping mode can be returned to / restored. The frequency channels after unavailability determination can be determined by increasing the number of unusable channels by a predetermined number. For example, if ch4 is determined to be unusable, ch10, which is the sum of ch4 and a predetermined number of 6, can be used, and after ch10, ch7 can be used by returning to the initial frequency hopping mode. When the predetermined number is greater than the normal frequency hopping interval, the frequency channels to be used next can be further separated from the unusable channels. This also applies when using functions.

[0147] Furthermore, the frequency channel to be used after unavailability is determined can be predetermined. For example, after unavailability is determined, ch2 can always be used, and then the frequency channel to be used can be determined by a hopping mode or function.

[0148] The timing of setting the threshold TH by the control device 40 is not limited to step S150. The threshold TH can be set by the control device 40 at any time before the unavailability determination process is performed (step S160). For example, after the startup process is performed and before data communication is performed, the control device 40 can set the threshold TH individually / differently for all frequency channels. According to this setting scheme, it is not necessary to set the threshold TH each time the number of communication records exceeds the baseline number ST.

[0149] An example is shown in which, when the control device 40 determines that one of the frequency channels is unavailable during the target frequency channel determination process with a monitoring device 30 (SBM2), channel information (CI) is sent to SBM2, but the invention is not limited to this example. Channel information can be sent not only to SBM2, but also to other monitoring devices (SBM1, SBM3). For example, it can be... Figure 13 Channel information is sent to SBM1 after SBM1(D), and channel information can be sent to SBM3 after SBM3(D). That is, unavailable channels can be shared by all monitoring devices 30 that are wirelessly communicating with control device 40.

[0150] Frequency channel information can be used as learning data. Frequency channel information may be, for example, information about frequency channels with electric field strengths above a predetermined threshold and / or information about frequency channels with electric field strengths below a predetermined threshold. As learning data, data for each (all) available frequency channel may be provided, or data for a subset of frequency channels may be provided. For example, when the learning data includes (i) information about frequency channels with electric field strengths below a predetermined threshold and (ii) information about frequency channels with electric field strengths above a threshold, the threshold TH for frequency channels with low electric field strengths is set to a value lower than the threshold TH for frequency channels with high electric field strengths. For example, when the learning data only includes information about frequency channels with electric field strengths below a predetermined threshold, the threshold TH for frequency channels included in the learning data is set to a value lower than the threshold TH for frequency channels not included in the learning data.

[0151] (Second Embodiment)

[0152] The second embodiment is a modification of the previous embodiment, which serves as the basic structure, and the description of the previous embodiment can be combined. In the previous embodiment, unavailability was determined by accumulating the communication records of each frequency channel. Alternatively, unavailability can be determined by accumulating the communication records of each group, which has multiple successive frequency channels, into a single unit.

[0153] Figure 14 An example of a target frequency channel determination process performed by a control device 40 in a battery management system 60 according to this embodiment is shown. Figure 15 An example of a threshold TH set based on communication records and learning data for each group is shown. Figure 15 In, with Figure 10 Similarly, the threshold TH is represented by a dashed line. Furthermore, for clarity, one or more records showing communication quality degradation in the communication logs are shaded.

[0154] Figure 14 The process of steps S100 to S120 shown is the same as that in the previous embodiment. Figure 8 The processes shown in steps S100 to S120 are the same. The control device 40 (i.e., the wireless IC 44) determines the frequency channel to be used through frequency channel hopping and performs a data transmission / reception process with a monitoring device 30. Then, the communication quality is evaluated based on the transmission / reception results.

[0155] After executing step S120, the control device 40 accumulates the communication quality assessment results performed in step S120 into a communication record for that group or a group communication record (step S130A). In this embodiment, the control device 40 does not accumulate the communication records for each frequency channel individually or separately. The control device 40 sets up a group with multiple frequency channels that are consecutive to each other as a unit, and accumulates communication records for one unit of each group.

[0156] For example, such as Figure 15 As shown, the control device 40 divides the 10 available channels into 5 groups, with 2 channels in each group. Figure 15 In this context, the first group (1G) includes ch1 and ch2. The second group (2G) includes ch3 and ch4. The third group (3G) includes ch5 and ch6. The fourth group (4G) includes ch7 and ch8. The fifth group (5G) includes ch9 and ch10. For example, the control device 40 accumulates the communication quality assessment results of ch1 and ch2 into a communication record for the first group (1G).

[0157] After executing step S130A, the control device 40 determines whether the communication records of the group, including the frequency channel currently in use, exceed a reference number ST (step S140A). When it is determined in step S140A that the communication records of the group are equal to or less than the reference number ST, the control device 40 terminates the series of processes. The control device 40 determines that the frequency channel currently set as the target frequency channel should remain the same as that used in frequency channel hopping.

[0158] When it is determined in step S140A that the number of group communication records has exceeded the baseline number ST, the control device 40 sets the threshold TH for the group based on the learning data (step S150A). The control device 40 sets the threshold TH for the group, including the frequency channels used for communication during the transmission / reception process in step S110. Figure 15 As shown by the dashed lines, a threshold TH is set for each group based on the learning data. In this embodiment, since the electric field strength of ch7 and / or ch8 is low, the threshold TH of the fourth group (4G), which includes ch7 and ch8, is set lower than the threshold TH of the other groups (1G to 3G, 5G).

[0159] After performing step S150A, the control device 40 performs an unavailability determination of the group including the frequency channel used for communication at this time (step S160A). The control device 40 determines whether the relevant group is unavailable in the next and subsequent times by comparing (i) a value related to communication quality degradation in the communication record of the relevant group with (ii) a threshold TH.

[0160] When the value related to communication quality degradation in step S160A is equal to or less than the threshold TH, the control device 40 determines that there is no problem using the relevant group in the next and subsequent uses, and terminates the series of processes. That is, the control device 40 determines that the frequency channel currently set for the target frequency channel used for frequency channel hopping should remain unchanged.

[0161] When the value related to communication quality degradation in step S160A exceeds the threshold TH, the control device 40 determines that the relevant group is unavailable in the next and subsequent times. The control device 40 determines that all frequency channels in the relevant group are unavailable. For example, in... Figure 15 In the process, the rate of communication quality degradation in the fourth group (4G) exceeds the threshold TH, and the control device 40 determines that the fourth group, namely ch7 and ch8, is unavailable.

[0162] When a set is determined to be unavailable, the control device 40 executes step S170 and terminates the process as follows. Figure 8 The process is illustrated in the diagram. Control device 40 determines one or more target frequency channels by excluding one or more frequency channels included in the unavailable group from the target frequency channels for frequency channel hopping. For example, when using... Figure 9 When the frequency hopping pattern shown is determined and the fourth group is unavailable, ch7 and ch8 can be excluded to determine a new frequency hopping pattern. Alternatively, unavailable channels can remain in the hopping pattern, but when selecting unavailable channels (e.g., ch7 or ch8), they can be de-used by performing frequency channel hopping again.

[0163] <Overview of the Second Embodiment>

[0164] According to this embodiment, the same effect as the construction described in the previous embodiment can be obtained. Specifically, the control device 40 evaluates the communication quality based on the transmission / reception results of data in a predetermined frequency channel and accumulates communication records in groups. Then, when the value related to communication quality degradation in the communication records of a group exceeds a threshold TH, all frequency channels in that group are determined to be unusable and excluded from one or more target frequency channels. In this way, one or more channels are determined to be unusable by using values ​​based on actual data transmission / reception results (specifically, values ​​related to communication quality degradation in the communication records). Therefore, this system allows the influence of variable factors such as temperature and vibration to be taken into account (e.g., reflected).

[0165] Furthermore, the control device 40 sets a threshold TH for each group based on the learning data. That is, the threshold TH is set individually (e.g., differently) for the corresponding group based on the electric field strength. Compared to two or more frequencies that are far apart, two or more close and "successive" frequencies have similar (i.e., substantially the same level) electric field strengths. Therefore, even by setting a single threshold TH for a group of channels (i.e., a group of frequencies), the reliability of wireless communication can be improved, taking into account the effects of initial factors.

[0166] In this embodiment, communication records and threshold TH are managed in groups, and unavailability is determined within such groups. Therefore, the process load on the control device 40 (i.e., the master device) is reduced.

[0167] In addition to replacing one frequency channel unit with a set of frequency channel units, the construction described in this embodiment can also be combined with the construction described in the previous embodiment and its modifications(s).

[0168] (Third Embodiment)

[0169] This embodiment is a modification of the previous embodiment, which serves as the basic structure, and the descriptions of the previous embodiment can be combined. After determination, frequency channels determined to be unusable can be excluded from the target frequency channel hopping. Conversely, when predetermined conditions are met, excluded channels can be restored (i.e., returned to be used as available channels).

[0170] Figure 16 An example of a return process performed by the control device 40 in the battery management system 60 according to this embodiment is shown. When an unavailable channel is set, the control device 40 performs the return process as shown below.

[0171] like Figure 16 As shown, firstly, the control device 40 sets return conditions based on the learning data (step S300). When a threshold TH is set for each frequency channel, the control device 40 sets return conditions for each frequency channel. When a threshold TH is set for each group, the control device 40 sets return conditions for each group.

[0172] The return condition can be the number of transmissions / receptions after unavailability is determined, such as the number of times monitoring data is received. Alternatively, the number of times a start signal, such as an IG signal, is turned on and off can be used, or the distance traveled by vehicle 10 can be used. For example, if the number of times the start signal is turned on and off is used, the control device 40 sets the number of times required to recover a frequency channel with a low electric field strength to be greater than the number of times required to recover a frequency channel with a high electric field strength based on the learning data.

[0173] After executing step S300, the control device 40 determines whether the return condition is met (step S310). If it is determined that the return condition is not met, the process of step S310 is executed again.

[0174] When the return condition is determined to be met in step S310, the control device 40 resets the communication record (step S320) and ends the series of processes. When the return condition is set for each frequency channel, the communication record of the frequency channel that meets the return condition is reset, and the frequency channel that has been determined to be unavailable is returned to the target / available frequency channel. When the return condition is set for each group, the communication record of the group that meets the return condition is reset, and all frequency channels included in the group are returned to the target / available frequency channel.

[0175] When a frequency channel or group meets the return condition, the control device 40 resets the communication records of only the frequency channel or group that meets the return condition. The control device 40 can also reset the communication records of all available frequency channels (e.g., 10 channels) that can be used to transmit and receive data. That is, all communication records can be reset simultaneously.

[0176] <Overview of the Third Embodiment>

[0177] According to this embodiment, the learned data is used as the return condition for returning to / recovering unavailable channels. By using the learned data, the return time varies. Frequency channels with low electric field strength, i.e., frequency channels where communication quality tends to deteriorate, are difficult to return to (i.e., are constructed to be difficult to return to / recover). On the other hand, frequency channels with high electric field strength, i.e., frequency channels where communication quality is unlikely to deteriorate, are very likely to return. Therefore, compared to a construction where the return conditions are consistent, the number of times communication quality degradation occurs can be reduced. Thus, the reliability of the system is further improved.

[0178] The construction described in this embodiment can be combined with the construction described in the first embodiment or the construction described in the second embodiment.

[0179] (Fourth Embodiment)

[0180] This embodiment is a modification of the previous embodiment, which serves as the basic structure, and the descriptions of the previous (or more) embodiments can be combined. In the previous (or more) embodiments, the relationship between the execution timing of the target frequency channel determination process and the driving state of vehicle 10 was not specifically mentioned. In contrast to the above, the target frequency channel determination process can be performed in association with the driving state of vehicle 10.

[0181] Figure 17 The process timing of step S110 is shown, that is, the timing of the data transmission / reception process in the battery management system 60 according to this embodiment. For example... Figure 17As shown in section (a), the control device 40 performs the target frequency channel determination process, which includes data transmission / reception, only during the driving of the vehicle 10. That is, the target frequency channel determination process can be configured not to be performed when the vehicle is not driving.

[0182] like Figure 17 As shown in section (b), the control device 40 can perform a target frequency channel determination process, including data transmission / reception, during both driving (driving time) and non-driving (non-driving time). That is, the target frequency channel determination process can be performed when the vehicle is not driving. Non-driving time refers to the period during which the start signal (e.g., the IG signal) is off or the start signal remains on and the vehicle 10 is parked or stationary. Even when the start signal is off, if the battery pack 21 or battery 15 is configured to continuously supply power to the system, the control device 40 can perform the target frequency channel determination process even when the vehicle is not driving.

[0183] Notice, Figure 12 The sharing process shown and Figure 16 The return procedure shown can be executed together with the target frequency channel determination procedure. In other words, the target frequency channel determination procedure, the sharing procedure, and the return procedure can all be executed when the vehicle is not in motion.

[0184] <Overview of the Fourth Embodiment>

[0185] According to this embodiment, the target frequency channel determination process can be performed in relation to the vehicle's driving state. When not driving, (i) the temperature is lower, (ii) the load on the assembled battery 20 is lower, and vibration is less. Thus, the influence of these variable factors is smaller when not driving. Therefore, the initial factors, namely the electric field strength levels in the control device 40 and monitoring device 30, have a significant impact on communication quality. By using learned data of the electric field strength, the accuracy of unavailable channel determination can be improved.

[0186] In this embodiment, an example is shown where the target frequency channel determination process is performed only during driving or during both driving and non-driving periods. For example, during driving, only steps S100 and S110 are performed, while during non-driving periods, steps S100 to S170 can be performed. During driving, only steps S100 to S130 can be performed, while during non-driving periods, steps S100 to S170 can be performed. This reduces the process load and communication load of the control device 40 during driving.

[0187] The construction described in this embodiment can be combined with any of the constructions described in the first embodiment, the second embodiment, and the third embodiment.

[0188] (Fifth Embodiment)

[0189] This embodiment is a modification of the previous embodiment, which serves as the basic structure, and the description of the previous embodiment can be combined with it. In the previous (or more) embodiments, a threshold for determining unavailable channels was set based on learning data. Alternatively, the target frequency channel for frequency channel hopping can be directly determined based on the learning data.

[0190] Figure 18 An example of a communication sequence between a monitoring device 30 and a control device 40 in a battery management system 60 according to this embodiment is shown. Figure 18 The execution timing of the target frequency channel determination process is shown. Figure 18 In, such as in Figure 5 As shown in the diagram, the monitoring IC 33 is shown as MIC33, the wireless IC 35 is shown as WIC35, and the control device 40 is shown as ECU40.

[0191] like Figure 18 As shown, after executing step S10, i.e. the startup process, and before executing the data communication process in step S20 and thereafter, the control device 40 executes the target frequency channel determination process (step S15).

[0192] The control device 40 determines one or more target frequency channels for frequency hopping based on initial information and the aforementioned learning data. Among the available frequency channels, the control device 40 does not use frequency channels with low electric field strength in both the control device 40 and the monitoring device 30, and determines frequency channels with high electric field strength as one or more target frequency channels. For example, frequency channels with electric field strength above a predetermined threshold are used as target frequency channels, and frequency channels with electric field strength below the threshold are set to unavailable.

[0193] The control device 40 shares the frequency channel information determined in step S15 with the monitoring device 30 by sending target frequency channel information to the wireless IC 35 of the monitoring device 30. During startup, the control device 40 and the monitoring device 30 share initial information about frequency channel hopping. The control device 40 performs frequency channel hopping according to the initial information and sends the target frequency channel information on the predetermined frequency channel. Since frequency channel hopping is performed according to the initial information, the control device 40 and the monitoring device 30 can use a common frequency channel and can share the channel information of the target frequency channel.

[0194] The process described in step S15 is performed between the control device 40 and each monitoring device 30. After executing step S15, the control device 40 executes the request data transmission process (step S20). The control device 40 performs frequency channel hopping on the frequency channel determined in step S15 as the target frequency channel, and determines the frequency channel to be used for frequency channel hopping. The control device 40 transmits the request data on the determined frequency channel (i.e., on the determined frequency). After executing step S15, the battery management system 60 periodically executes the processes from S20 to S25.

[0195] <Overview of the Fifth Embodiment>

[0196] According to this embodiment, the control device 40, acting as the main device, performs a target frequency channel determination process after executing the startup process. Before transmitting and receiving data, the control device 40 determines the frequency channel used in frequency channel hopping based on pre-stored learning data. During cyclic data communication with the monitoring device 30, the control device 40 does not necessarily need to perform the target channel determination process. Therefore, the communication load can be reduced.

[0197] The control device 40 can evaluate communication quality and data transmission and reception, and can accumulate the evaluation results as communication records. That is, steps S100 to S130 (S130A) can be executed cyclically. By accumulating communication records, the accumulated records can be used to update the learning data, which will be described later.

[0198] An example is shown of performing the target frequency channel determination process after the startup process. However, the invention is not limited to this example. The control device 40 can perform the target frequency channel determination process at any time, as long as it is performed between the time the control device 40 starts and the time data is sent / received from / to the monitoring device 30. For example, the target frequency channel determination process can be included in the startup process.

[0199] When the learning data has fixed values, i.e., when no learning data update (described later) is performed, the control device 40 and the monitoring device 30 can each perform the target frequency channel determination process based on the learning data. The monitoring device 30 also pre-stores learning data with the same content as the control device 40. The processing content of the target frequency channel determination process is shared by both the control device 40 and the monitoring device 30. Therefore, one or more frequency channels used in frequency channel hopping can be shared without performing data communication.

[0200] As described in the previous (or more) embodiments, information from frequency channels with electric field strengths above a predetermined threshold or information from frequency channels with electric field strengths below a predetermined threshold can be used as learning data, for example, as learning data. The learning data may include information from target frequency channels and / or information from unavailable frequency channels.

[0201] (Sixth Embodiment)

[0202] This embodiment is a modification of the previous embodiment, which serves as the basic structure, and descriptions of the previous (or more) embodiments can be combined. In the preceding embodiments, the learning data was a fixed value. Unlike the above, the learning data can be a variable value.

[0203] Figure 19 An update process performed by the control device 40 in the battery management system 60 according to this embodiment is shown. The control device 40 performs the update process at predetermined intervals.

[0204] like Figure 19 As shown, control device 40 determines whether a predetermined event has occurred (step S400). The predetermined event may occur during the switching timing of a start signal, such as an IG signal. The predetermined event may occur, for example, when the start signal switches from on to off, or when the start signal switches from off to on. The predetermined event may occur, for example, for each predetermined travel distance. The predetermined event may occur, for example, whenever the number of times monitoring data is received reaches a predetermined number.

[0205] When a predetermined event is determined to have occurred in step S400, the control device 40 updates the learning data based on accumulated communication records (or multiple communication records) (step S410). The control device 40 can update the learning data by fusing the initial learning data and one or more communication records according to preset rules. For example, the control device 40 determines frequency channels where communication quality may deteriorate and frequency channels where communication quality cannot deteriorate based on the communication quality degradation rate in the communication records, and uses these as new learning data. Then, the control device 40 can update the learning data by replacing the initial learning data with the new learning data.

[0206] <Overview of the Fifth Embodiment>

[0207] According to this embodiment, the control device 40, acting as the master device, updates the learning data using accumulated communication records(s) when a predetermined event is observed. Based on the above, unavailable channels can be determined according to the actual usage environment, and the target frequency channel is thus / ultimately determined. For example, highly reliable wireless communication can be achieved when variable factors such as temperature and vibration have a significant impact.

[0208] The construction described in this embodiment can be combined with any of the first to fifth embodiments.

[0209] (Other embodiments)

[0210] The disclosure in the specification and drawings is not limited to exemplary embodiments. The invention encompasses the illustrated embodiments and modifications thereto by those skilled in the art. For example, the invention is not limited to portions and / or combinations of elements shown in the embodiments. The invention can be implemented in various combinations. The invention may have additional portions that can be added to embodiments. The invention includes cases where portions and / or elements of embodiments are omitted. The invention includes the reassignment or combination of portions and / or elements between one embodiment and another. The disclosed technical scope is not limited to the description of the embodiments. It should be understood that some of the disclosed technical scope is indicated by the description of the claims and includes every modification within the equivalent meaning and scope of the claims.

[0211] The disclosures in the specification, drawings, etc., are not limited to the descriptions in the claims. The disclosures in the specification, drawings, etc., encompass the technical concepts described in the claims and further extend to various technical concepts that are broader than those in the claims. Therefore, without being limited to the descriptions in the claims, various technical concepts can be extracted from the disclosures in the specification, drawings, etc.

[0212] When a component or layer is described as “set on” or “connected”, the component or layer may be directly set on or connected to another component or layer, or an intermediate component or layer may exist between them. Conversely, when a component or layer is described as “directly set on” or “directly connected”, there is no intervening component or intermediate layer. Other terms used to describe relationships between components (e.g., “between” vs. “directly between”, and “adjacent” vs. “directly adjacent”) should be interpreted similarly. As used herein, the term “and / or” includes any and all combinations relating to one or more of the related listed items. For example, the term A and / or B includes only A, only B, or both A and B.

[0213] Spatial relative terms such as “inside,” “outside,” “back,” “bottom,” “low,” “top,” and “high” are used herein to describe the relationship between one element or feature and another. In addition to the orientations described in the drawings, spatial relative terms are also intended to include different orientations of the device in use or operation. For example, when the device in the drawing is flipped, an element or feature described as “below” or “directly below” is pointed above another element or feature. Therefore, the term “below” can include both “above” and “below.” The device may be oriented in another direction (e.g., rotated 90 degrees or in any other direction), and the spatial relative terms used herein are interpreted accordingly.

[0214] Examples of methods and / or functions provided by microcomputers or ICs have been shown, but the invention is not limited thereto. Each method and / or function may be implemented by a dedicated computer including a processor that executes a computer program. Alternatively, it may be implemented using dedicated hardware logic circuitry. Furthermore, it may be implemented by one or more dedicated computers constructed from (i) a processor that executes a computer program and (ii) a combination of one or more hardware logic circuits. The computer program may be stored as instructions executed by the computer on a computer-readable, non-transitory, tangible recording medium. The methods and / or functions may be provided by software recorded in a physical memory device and by a computer executing it (software only, hardware only, or a combination thereof). For example, some or all of the functions provided by the processor may be implemented as hardware. Modes in which a function is implemented as hardware include modes using one or more ICs. The processor may be implemented by using an MPU, GPU, or DFP instead of a CPU. The processor may be implemented by combining multiple types of arithmetic processing units (e.g., CPU, MPU, and GPU). The processor may be embodied as a system-on-a-chip (SoC). Furthermore, various processing units may be implemented using FPGAs or ASICs. Various programs may be stored in a non-transitory, physical recording medium. DFP is an abbreviation for Data Stream Processor, which can use various storage media such as HDD, SSD, flash memory, and SD card as program storage media. SoC is an abbreviation for System-on-Chip. FPGA is an abbreviation for Field Programmable Gate Array. ASIC is an abbreviation for Application-Specific Integrated Circuit. HDD is an abbreviation for Hard Disk Drive. SSD is an abbreviation for Solid State Drive. SD is an abbreviation for Secure Digital.

[0215] For example, although an example of a monitoring device 30 including a microcomputer 34 is shown, the invention is not limited to such examples. Figure 20 As shown, a battery management system 60 can be used, wherein the monitoring device 30 does not include a microcomputer 34. Figure 20 Corresponding to Figure 4In this configuration, the wireless IC 35 sends / receives data to / from the monitoring IC 33. The wireless IC 35 can perform timed control based on sensing and self-diagnosis by the monitoring IC 33, or the main microcomputer 45 of the control device 40 can perform the same operation.

[0216] The arrangement and number of battery packs 21 and battery cells 22 constituting the assembled battery 20 are not limited to the examples described above. The arrangement of monitoring devices 30 and / or control devices 40 in battery pack 11 is not limited to the examples described above.

[0217] An example in which the battery pack 11 includes a control device 40 is shown, but the invention is not limited to such an example. Multiple control devices 40 may be provided. The battery pack 11 may include one or more monitoring devices 30 and one or more control devices 40. The battery management system 60 may include multiple sets of wireless communication systems constructed between the control devices 40 and the one or more monitoring devices 30.

[0218] An example is shown in which the monitoring device 30 includes a monitoring IC 33, but the invention is not limited to this example. Multiple monitoring ICs 33 may be provided. In this case, a wireless IC 35 may be provided for each monitoring IC 33, or a wireless IC 35 may be provided for multiple monitoring ICs 33.

[0219] An example in which a monitoring device 30 is provided for each battery pack 21 has been shown, but the invention is not limited to this example. For example, a monitoring device 30 may be provided for multiple battery packs 21. Multiple monitoring devices 30 may be provided for one battery pack 21.

[0220] An example is shown in which the wireless IC 44 includes a microcomputer 441, but the invention is not limited to this example. Constructions may include the microcomputer 441 omitted therefrom. A main microcomputer 45 may provide some of the functionality of the wireless IC 44 described above. For example, the wireless IC 35 may be constructed without a microcomputer / microcontroller. The microcomputer 34 may provide some of the functionality of the wireless IC 35 described above.

[0221] An example is shown in which the wireless IC 44 of the control device 40 performs the aforementioned target frequency channel determination process, etc., but the present invention is not limited to this example. Elements of the control device 40 can perform the same operations. For example, the main microcomputer 45 can perform a portion of the aforementioned process.

[0222] An example has been shown where the control device 40 is the master device and the monitoring device 30 is the slave device, but the invention is not limited to this example. Each of the above embodiments is also applicable to configurations in which one of the control device 40 and the monitoring device 30 acts as the master device and the other as the slave device to perform wireless communication using frequency channel frequency hopping. For example, the monitoring device 30 can act as the master device and the control device 40 can act as the slave device. In this case, the monitoring device 30 pre-stores learning data. The master device pre-stores data related to the electric field strength in the housing for each available frequency channel, which, as learning data, can be used to send and receive data to / from each slave device performing wireless communication. The master device determines one or more target frequency channels for frequency channel frequency hopping based on the learning data.

Claims

1. A battery management system, comprising: A monitoring device is installed in the housing containing the corresponding battery and monitors battery information indicating the corresponding status of the corresponding battery. as well as A control device acquires battery information from the monitoring device and executes a predetermined process, wherein... The control device and the monitoring device use frequency channel hopping to perform wireless communication when the control device is the master device and the monitoring device is the slave device. The main device The following frequency channels store learning data related to the electric field strength within the housing: these frequency channels can be used to send data to and receive data from each of the slave devices for wireless communication. Based on the learning data, the target frequency channel for frequency hopping is determined by excluding frequency channels that may have degraded communication quality. The predetermined frequency channel is determined by performing frequency hopping on the frequency channel, and Based on the results of sending data to and receiving data from the slave device on the predetermined frequency channel, the communication quality is evaluated and accumulated as a communication record.

2. The battery management system according to claim 1, wherein The main device When the value associated with communication quality degradation in the communication records of the predetermined frequency channel exceeds a threshold, the target frequency channel is determined by identifying the predetermined frequency channel as an unavailable channel and excluding the predetermined frequency channel from the target frequency channel. The threshold is set independently for the frequency channel that can be used to communicate with the slave device based on the learning data.

3. The battery management system according to claim 2, wherein... The master device sets the threshold for each frequency channel that can be used to send data to and receive data from the slave device, based on the electric field strength.

4. The battery management system according to claim 2 or 3, wherein The main device When the unavailable channel meets the return condition, at least the communication records used for the unavailable channel are reset to return the unavailable channel to the target frequency channel. The return conditions are set independently for available frequency channels based on the learning data.

5. The battery management system according to claim 1, wherein... The master device determines the target frequency channel based on the learning data during the time period between: (i) the time when the master device is started, and (ii) the time during which data communication with the slave device begins from the time of startup to the time during which data exchange with the slave device begins.

6. The battery management system according to claim 1, wherein The main device The predetermined frequency channel for communication is determined by performing frequency channel hopping. Based on the results of communication data to and from the slave device on the predetermined frequency channel, the communication quality is evaluated and accumulated into a communication record. The learning data is updated for each scheduled event using accumulated communication records.

7. The battery management system according to any one of claims 1-3, wherein The antenna of the control device is housed within the housing.

8. The battery management system according to any one of claims 1-3, wherein The control device is housed within the housing.

Images