Battery monitoring system, control device, monitoring device and program

Abstract

To provide a battery monitoring system suppressing the number of times of broadcast communication as much as possible, a control device, and a program.SOLUTION: A control device 50 instructs contents instructing an acquisition of battery monitoring information to each of a plurality of monitoring devices 401 ... 40n by unicast communication UC in a communication cycle T, and contents instructing an acquisition timing of the battery monitoring information to the plurality of monitoring devices 401 ...40n by broadcast communication BC.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to a battery monitoring system, a control device, a monitoring device, and a program. [Background technology]

[0002] For example, vehicles such as hybrid vehicles (HVs), plug-in hybrid vehicles (PHVs), and electric vehicles (EVs) are equipped with assembled batteries, such as lithium-ion batteries, for vehicle operation. Assembled batteries are made up of a combination of battery cells, and a configuration has been proposed in which a monitoring circuit monitors the state of each battery cell.

[0003] In this case, in the case of a battery management system (BMS) in which the monitoring circuit is mounted in a satellite configuration, the monitoring circuit is mounted in the monitoring device, the control device communicates with the satellite battery module via a wireless communication unit, and the monitoring circuit mounted in the monitoring device acquires the status of the battery cells based on commands from the control device.

[0004] Conventionally, the control device sends broadcast communications without delivery confirmation multiple times in different frequency bands to the monitoring device to instruct the monitoring device on the battery control details and measurement timing, including measuring the voltage of the battery pack. The monitoring device responds to the control device with the measurement results by one or multiple unicast communications. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] WO 15 / 189898 Summary of the Invention [Problem to be solved by the invention]

[0006] In the system described in the Background Art section, it takes a long time to transmit commands due to the multiple broadcast communications.

[0007] An object of the present disclosure is to provide a battery monitoring system, a control device, a monitoring device, and a program that can minimize the number of broadcast communications. [Means for solving the problem]

[0008] Claim 1st article The above invention is directed to a battery monitoring system that includes a plurality of monitoring devices that acquire battery monitoring information used to monitor the status of a battery, and a control device that acquires the battery monitoring information by wirelessly communicating with the plurality of monitoring devices and executes predetermined processing. There are several types of battery monitoring information. The control device communicates with each of the plurality of monitoring devices by unicast communication during a communication cycle for communication with the plurality of monitoring devices. Select the type indicated from multiple types The instruction section issues instructions including instructions to acquire battery monitoring information and instructions to the plurality of monitoring devices via broadcast communication as to the timing of acquiring battery monitoring information.

[0009] According to the inventions described in claims 1 and 10, the instructions to acquire battery monitoring information via unicast communication and the instructions to indicate the timing of acquisition via broadcast communication are used in combination, so the number of broadcast communications can be minimized compared to conventional configurations in which the instructions to acquire battery monitoring information and the timing are specified via broadcast communication. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram illustrating a battery monitoring system according to a first embodiment. [Figure 2] FIG. 1 is a perspective view showing a schematic structure of a battery pack; [Figure 3] FIG. 1 is a plan view schematically illustrating the structure of a battery pack. [Figure 4] Electrical configuration diagram of the battery monitoring system [Figure 5] Communication sequence diagram 1 showing the outline of the process for establishing communication between the monitoring device and the control device [Figure 6]Sequence diagram 2 showing the outline of the process for establishing communication between the monitoring device and the control device [Figure 7] Sequence diagram 1 showing the outline of the flow of communication processing between the control device and the monitoring device [Figure 8] Sequence diagram 2 showing the outline of the communication process between the control device and the monitoring device [Figure 9] 1 is a flowchart showing the processing performed by the control device; [Figure 10] FIG. 1 is a sequence diagram illustrating a process flow between a control device and multiple monitoring devices. [Figure 11] 10 is a flowchart showing the outline of a re-communication establishment process; [Figure 12] 10 is a flowchart showing an outline of the processing contents of the monitoring device in the second embodiment. [Figure 13] A diagram conceptually illustrating the functional configuration of the components of a battery monitoring system. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, several embodiments of the battery monitoring system 1 will be described with reference to the drawings. In the embodiments described below, the same or similar components in each embodiment will be denoted by the same or similar reference numerals, and the description thereof may be omitted.

[0012] (First embodiment) The first embodiment will be described with reference to Figures 1 to 11. As shown in Figure 1, a battery monitoring system 1 is mainly composed of a battery pack system 2 and is built into a vehicle 10. The vehicle 10 may be a hybrid vehicle (HV), a plug-in hybrid vehicle (PHV), an electric vehicle (EV), or the like, and runs using a battery pack 12 (see Figure 2) of an on-board battery pack 11 as at least a part of its drive source.

[0013] A battery pack 11, a power control unit (hereinafter abbreviated as PCU) 14, a motor 15, and a host ECU 16 are mounted inside the vehicle body 13. The host ECU 16 is configured as an electronic control device. The battery pack 11 may be arranged in the engine compartment of the vehicle body 13, but may also be arranged under the seat of a passenger, for example, the driver, around the frame of the vehicle body 13, in the trunk, or the like.

[0014] As shown in Fig. 2, the battery pack 11 includes a plurality of battery stacks 20 as battery modules, and each battery stack 20 houses a large number of battery cells 22 to form an assembled battery 12. The assembled battery 12 stores power to drive the motor 15, and is used as a drive source for the vehicle 10. The PCU 14 shown in Fig. 1 supplies the power stored in the assembled battery 12 of the battery pack 11 to the motor 15. When braking the vehicle 10, the motor 15 returns regenerative power to the assembled battery 12, and the assembled battery 12 of the battery pack 11 is configured to be charged according to the power generated by the motor 15.

[0015] <Structure of battery pack 11> An example of the structure of the battery pack 11 will be described below with reference to FIGS. 2, the housing 30 is indicated by a two-dot chain line, and the housing 30 is shaped like a substantially rectangular parallelepiped. The longitudinal direction of the housing 30 is indicated as the X direction, and the lateral direction is indicated as the Y direction. The up-down direction perpendicular to the mounting surface on the vehicle body 13 is indicated as the Z direction. The X direction, Y direction, and Z direction are perpendicular to one another.

[0016] As shown in FIG. 2, the battery pack 11 is provided in a housing 30 with a battery pack 12, multiple monitoring devices 40, and a control device 50. The monitoring device 40 is equipped with a monitoring circuit that monitors the battery pack 11 and is called a satellite battery module (SBM). The Z-direction lower surface of the housing 30 is the mounting surface for the vehicle body 13. In this embodiment, the X-direction is the left-right direction of the vehicle 10, the Y-direction is the front-rear direction of the vehicle 10, and the Z-direction is the up-down direction of the vehicle 10. The arrangements shown in FIGS. 2 and 3 are merely examples. The mounting direction on the vehicle body 13 is merely an example, and the battery pack 11 may be mounted in any manner relative to the vehicle 10.

[0017] The battery pack 12 has a plurality of battery stacks 20 arranged side by side in the X direction. The battery stacks 20 may be referred to as battery blocks, battery modules, etc. The battery pack 12 may be configured by connecting a plurality of battery stacks 20 in series and / or parallel, but this embodiment shows an example in which the plurality of battery stacks 20 are connected in series.

[0018] Each battery stack 20 has a plurality of battery cells 22. The plurality of battery cells 22 are housed in respective battery cases (not shown), which fix the relative positions of the plurality of battery cells 22. The battery cases are made of metal or resin. When the battery case is made of metal and configured in the shape of a rectangular box, an electrically insulating member is entirely interposed between the wall surface of the battery case and the battery cells 22. The insulating member may be partially interposed between the wall surface of the battery case and the battery cells 22.

[0019] The form of the fixing member is not particularly limited as long as it can fix the relative positions of the multiple battery cells 22. For example, a configuration in which the multiple battery cells 22 are restrained by a strip-shaped band may be adopted. In this case, separators may be interposed between the multiple battery cells 22 to maintain a distance between them.

[0020] The battery stack 20 has a plurality of battery cells 22 connected in series. The battery stack 20 of this embodiment is configured by connecting a plurality of battery cells 22 arranged side by side in the Y direction in series, and the assembled battery 12 provides a DC voltage source.

[0021] The battery cell 22 is a secondary battery that generates an electromotive force through a chemical reaction, and examples of the secondary battery that can be used include a lithium-ion secondary battery, a nickel-metal hydride secondary battery, and an organic radical battery. A lithium-ion secondary battery is a secondary battery that uses lithium as a charge carrier. Secondary batteries that can be used for the battery cell 22 include not only secondary batteries with liquid electrolytes, but also so-called all-solid-state batteries that use solid electrolytes.

[0022] The battery cells 22 are stacked so that the side surfaces of the battery cases are in contact with each other in the Y direction. Each battery cell 22 has a positive terminal 23 and a negative terminal 24 at both ends in the X direction that protrude in the Z direction, more specifically in the Z+ direction indicating upward. The Z-direction positions of the protruding end faces of these positive terminals 23 and negative terminals 24 are the same for each battery cell 22. The battery cells 22 are stacked so that the positive terminals 23 and negative terminals 24 are alternately arranged in the Y direction.

[0023] A pair of linear busbar units 25 are arranged on both ends in the X direction on the top surface of each battery stack 20. The busbar units 25 are arranged at both ends in the X direction on the protruding end faces of the positive electrode terminals 23 and negative electrode terminals 24 of the multiple battery cases.

[0024] Each busbar unit 25 has a plurality of busbars 26 that electrically connect positive terminals 23 and negative terminals 24 that are alternately arranged in the Y direction, and busbar covers 27 that cover the plurality of busbars 26. The busbars 26 are plates made of a metal with good conductivity, such as copper or aluminum. The busbars 26 electrically connect the positive terminals 23 and negative terminals 24 of battery cells 22 that are adjacent to each other in the Y direction. As a result, in each battery stack 20, the plurality of battery cells 22 are connected in series.

[0025] Here, the electrical connection state of a certain battery stack 20 will be described. In a certain battery stack 20, one end of a certain first battery cell 22 is a positive electrode, and the other end is a negative electrode. A positive electrode terminal 23 is connected to the positive electrode of the battery cell 22, and a negative electrode terminal 24 is connected to the negative electrode. A second battery cell 22 is disposed on the Y-direction side of this first battery cell 22. The X-direction positions of the positive electrode and negative electrode of the second battery cell 22 are opposite to those of the first battery cell 22. The negative electrode terminal 24 of the first battery cell 22 is connected to the positive electrode terminal 23 of the second battery cell 22 by a bus bar 26.

[0026] Furthermore, a third battery cell 22 is disposed on the Y-direction side of the second battery cell 22. The third battery cell 22 is disposed such that the X-direction positions of the positive and negative electrodes of the third battery cell 22 are reversed to those of the second battery cell 22, and the negative terminal 24 of the second battery cell 22 and the positive terminal 23 of the third battery cell 22 are connected by a bus bar 26. In this manner, the multiple battery cells 22 are disposed side by side in the Y direction with the X-direction positions of the positive and negative electrodes interchanged, and the positive terminal 23 and the negative terminal 24 are connected by the bus bar 26. As a result, the battery cells 22 of each battery stack 20 are electrically connected in series.

[0027] In each battery stack 20, one of the two battery cells 22 located at the ends of the multiple battery cells 22 aligned in the Y direction has the highest potential, and the other has the lowest potential. A predetermined wiring is connected to at least one of the positive terminal 23 of the battery cell 22 with the highest potential and the negative terminal 24 of the battery cell 22 with the lowest potential.

[0028] 2 and 3, a plurality of battery stacks 20 are arranged in the X direction. In one of two battery stacks 20 adjacent to each other in the X direction, the positive electrode terminal 23 of the battery cell 22 with the highest potential is connected to the negative electrode terminal 24 of the battery cell 22 with the lowest potential in the other battery stack via a predetermined wiring. This electrically connects the plurality of battery stacks 20 in series.

[0029] Thus, one of the two battery stacks 20 located at the ends of the multiple battery stacks 20 lined up in the X direction becomes the highest potential side, and the other becomes the lowest potential side. In the battery stack 20 on the highest potential side, an output terminal is connected to the positive terminal 23 of the battery cell 22 with the highest potential among the multiple battery cells 22. In the battery stack 20 on the lowest potential side, an output terminal is connected to the negative terminal 24 of the battery cell 22 with the lowest potential among the multiple battery cells 22. These two output terminals are connected to electrical equipment such as the PCU 12 mounted on the vehicle 10. The positive terminal 23 and the negative terminal 24 may or may not at least partially face each other in the X direction.

[0030] Note that two battery stacks 20 adjacent to each other in the X direction do not necessarily have to be electrically connected via a predetermined wiring, and any two of the plurality of battery stacks 20 may be electrically connected via a predetermined wiring.

[0031] The bus bar cover 27 shown in Fig. 3 is made of an electrically insulating material such as resin. The bus bar cover 27 is provided linearly from one end of the battery stack 20 to the other in the Y direction so as to cover the multiple bus bars 26. The bus bar cover 27 may have a partition wall. The provision of the partition wall can improve the insulation between two bus bars 26 adjacent in the Y direction.

[0032] A monitoring device 40 is provided in each of the multiple battery stacks 20. As shown in FIG. 2 , the monitoring device 40 is disposed between a pair of busbar units 25 for each battery stack 20. The monitoring device 40 is disposed opposite the protruding end faces of the positive electrode terminal 23 and the negative electrode terminal 24 of the battery case in the Z direction. The monitoring device 40 and these end faces may be spaced apart in the Z direction, or may face each other and contact each other in the Z direction. An intervening object such as an insulating sheet may be provided between the monitoring device 40 and these end faces.

[0033] Monitoring device 40 is fixed to busbar unit 25 with screws or the like. As will be described later, monitoring device 40 is configured to be able to communicate wirelessly with control device 50. An antenna 49 (described later) provided in monitoring device 40 is arranged so as not to overlap with busbar unit 25 in the X and Y directions, that is, so as to protrude further in the Z direction than busbar unit 25.

[0034] It is preferable to use a non-magnetic material for the connecting members such as screws that connect the monitoring device 40 and the busbar unit 25, which can improve the performance of wireless communication. It is also preferable to use a non-magnetic material for the parts provided in the battery stack 20, especially if they do not need to be magnetic in terms of their characteristics.

[0035] In this embodiment, multiple monitoring devices 40 are arranged side by side in the X direction inside the housing 30. The multiple monitoring devices 40 are positioned at the same position in the Y direction. By adopting such an arrangement, the arrangement intervals between the multiple monitoring devices 40 can be shortened, and wireless communication characteristics can be improved.

[0036] The plurality of monitoring devices 40 are attached to the Z-direction end faces of the plurality of battery stacks 20, respectively, and the control device 50 is attached to one X-direction end face of all the battery stacks 20.

[0037] The antenna 57 of the control device 50 is provided so as to protrude in the Z direction beyond the busbar unit 25. The antenna 57 connected to the control device 50 is disposed at a height in the Z direction approximately the same as that of the antenna 49 of the monitoring device 40. Note that the positional relationship between the antennas 49 and 57 is not limited to this relationship.

[0038] The housing 30 has the ability to reflect electromagnetic waves, for example, as a countermeasure against EMC. EMC stands for Electromagnetic Compatibility. The housing 30 is made up of a resin material and a metal with magnetic properties for reflecting electromagnetic waves, i.e., a magnetic material. The housing 30 may be made up of a resin material, but the magnetic material may be configured to cover the resin material or may be embedded inside the resin material. The housing 30 may be made up of carbon fiber. The housing 30 may be made up of a material that has the ability to absorb electromagnetic waves instead of the ability to reflect electromagnetic waves.

[0039] The housing 30 has holes that communicate with the storage space for the battery pack 11 and the space outside it. The holes are used for ventilation, power lines, and signal lines. In the case of a configuration with holes, a cover (not shown) may be provided for the holes. The cover may be formed of, for example, a connector, an electromagnetic shielding member, or a sealing material, and closes part or all of the hole between the storage space for the battery pack 11 and the space outside it.

[0040] The covering portion may be made of, for example, a metal material having magnetic properties. The covering portion may contain a resin material, and the magnetic material may be configured to cover the resin material or may be embedded inside the resin material. The covering portion may be made of carbon fiber.

[0041] The holes in the housing 30 may be covered by elements accommodated in the housing space of the housing 30 without providing a separate cover. Furthermore, the power lines and signal lines may be arranged across the housing space and the external space while being held by an electrically insulating member that forms part of the wall of the housing 30.

[0042] The mounting structure of the multiple monitoring devices 40 and the control device 50 is not limited to the structure shown in Fig. 2. For example, the multiple monitoring devices 40 may be mounted on the multiple battery stacks 20 inside the housing 30, respectively, while the control device 50 may be mounted on the outer wall surface of the housing 30. For example, a mounting structure may be used in which a wall surface of the housing 30 is provided in an area where the monitoring devices 40 and the control device 50 face each other. In this case, although the radio wave propagation environment between the monitoring devices 40 and the control device 50 is worse than in the mounting structure shown in Fig. 2, it is sufficient if the monitoring devices 40 and the control device 50 can communicate with each other.

[0043] In this embodiment, a plurality of battery stacks 20 packed with a plurality of battery cells 22 are prepared as modules and directly housed in a housing 30, but the present invention may also be applied to a so-called moduleless structure. For example, as is called cell-to-pack, the modularization of the battery cells 22 may be omitted and the plurality of battery cells 22 may be directly housed in a battery pack 11. Cell-to-pack is the Japanese katakana spelling of Cell to Pack (CTP).

[0044] As referred to as module to platform, the battery stack 20 may be directly installed in the frame or platform of the vehicle 10. Module to platform is the Japanese kana spelling of Module to Platform (MTP). As referred to as cell to chassis, the battery cells 22 may be directly packed in the chassis of the vehicle 10 and mounted in the chassis as part of the body structure. Cell to chassis is the Japanese kana spelling of Cell to Chassis (CTC).

[0045] In this way, even if the battery pack 11 does not adopt a structure in which it is housed in the housing 30, diffuse reflection occurs when wireless communication is performed between the control device 50 and the monitoring device 40. Because the control device 50 and the monitoring device 40 are located in fixed locations, they are less susceptible to the effects of temporal fluctuations in communication position, such as the communication processing of a smartphone or tablet terminal, but the effects of diffuse reflection between the control device 50 and the monitoring device 40 are more likely to occur.

[0046] <Description of the Configuration of PCU 14, Motor 15, and Upper ECU 16> The PCU 14 shown in FIG. 1 performs bidirectional power conversion between the battery pack 11 and the motor 15 in accordance with a control signal from the upper ECU 16. The PCU 14 is configured to include, for example, an inverter that drives the motor 15 and a converter that boosts the DC voltage supplied to the inverter to be higher than the output voltage of the battery pack 11.

[0047] The motor 15 is an AC rotating electric machine, for example, a three-phase AC synchronous motor in which permanent magnets are embedded in the rotor. The motor 15 is driven by the PCU 14 to generate a rotational driving force, and the driving force generated by the motor 15 is transmitted to the driving wheels. On the other hand, when the vehicle 10 brakes, the motor 15 operates as a generator to perform regenerative power generation. The power generated by the motor 15 is supplied to the battery pack 11 through the PCU 12 and stored in the battery modules 12 of the battery pack 11.

[0048] The upper ECU 16 is configured to include a CPU, a ROM, a RAM, a memory such as a non-volatile semiconductor memory device, an input / output port for inputting / outputting various signals, and the like. A processing program executed by the upper ECU 16 is recorded in the memory, and the CPU executes the program stored in the memory. The memory is used as a non-transitory physical recording medium. The upper ECU 16 receives information such as the voltage and SOC (State Of Charge) of the battery modules 12 from the control device 50 of the battery pack 11, and controls the driving of the motor 15 and the charge / discharge of the battery pack 11 by controlling the PCU 12.

[0049] A current sensor 17 (see FIG. 4) is serially connected to the battery modules 12 in which the battery cells 22 are serially connected, whereby the current flowing through the entire battery modules 12 can be measured. As shown in FIG. 4, the current sensor 17 is connected to the upper ECU 16. The upper ECU 16 can acquire the current information flowing through the battery modules 12 and the battery cells 22 based on the sensing information of the current sensor 17.

[0050] Here, the current sensor 17 is connected to the host ECU 16, but the current sensor 17 may be connected to the control device 50, and the control device 50 may acquire information about the current flowing through the assembled battery 12 from the current sensor 17. Since the control device 50 and the host ECU 16 can be connected to each other for communication, whichever configuration acquires the current information from the current sensor 17 can share the information about the current flowing through the assembled battery 12.

[0051] The specific configurations of the monitoring device 40 and the control device 50 will be described below. <Specific configuration of the monitoring device 40 system> 4, monitoring device 40 is configured to include power supply circuits 41 to 43, a monitor IC 44, a microcomputer 45, a wireless IC 46, a selection circuit 47, a matching circuit 48, and an antenna 49. Power supply circuit 41 of monitoring device 40 generates an operating voltage using voltage supplied from battery stack 20 and supplies the generated voltage to power supply circuits 42 and 43, as well as to monitor IC 44. Power supply circuit 42 generates an operating voltage from the output of power supply circuit 41 and supplies this generated voltage to microcomputer 45. Power supply circuit 43 generates an operating voltage from the output of power supply circuit 41 and supplies this generated voltage to wireless IC 46.

[0052] A selection circuit 47 of the monitoring device 40 receives a cell temperature signal that measures the temperature of the battery cells 22 using a temperature sensor (not shown) mounted on the battery stack 20, and a sensor signal that is a cell discrimination signal that discriminates the type of battery cell 22, and selects the sensor signal and inputs it to the monitor IC 44. The monitor IC 44 of the monitoring device 40 senses information such as the cell voltage, cell temperature, and cell discrimination of the battery cells 22, and stores the battery monitoring information in the memory of the wireless IC 46 via the microcomputer 45. The monitor IC 44 performs a fault diagnosis of the circuit parts of the monitoring device 40, monitors the fault diagnosis information, and stores the fault diagnosis information in the memory of the wireless IC 46 via the microcomputer 45.

[0053] The microcomputer 45 of the monitoring device 40 receives battery monitoring information or fault diagnosis information input from the monitor IC 44 and transmits it to the wireless IC 46. The microcomputer 45 represents a control circuit having a function of controlling the schedule for the battery monitoring information or fault diagnosis of the monitor IC 44.

[0054] The wireless IC 46 of the monitoring device 40 receives battery monitoring information or fault diagnosis information from the microcomputer 45 and transmits the information to the master-side control device 50. At this time, the wireless IC 46 transmits the information to the wireless IC 54 of the control device 50, i.e., the master side, and receives the information from the wireless IC 54 of the control device 50. The wireless IC 46 is a communication device that controls the communication data size, communication format, schedule, error detection, etc. between the monitoring device 40 and the control device 50.

[0055] The matching circuit 48 and antenna 49 of the monitoring device 40 represent a physical interface for converting the output signal of the wireless IC 46 into radio waves and radiating them into space, and for receiving the radio waves that have propagated through space and inputting them into the wireless IC 46.

[0056] The microcomputer 45 may not be mounted, and in this case, it is preferable to configure the wireless IC 46 to directly communicate with the monitor IC 44. The wireless IC 46 of the monitoring device 40 may manage the acquisition schedule or transmission schedule of the battery monitoring information and fault diagnosis information of the monitor IC 44.

[0057] <Specific configuration of the control device 50 system> The control device 50 includes power supply circuits 51 and 52, a main microcomputer 53, a wireless IC 54, a sub-microcomputer 55, a matching circuit 56, and an antenna 57. The power supply circuit 51 of the control device 50 generates an operating voltage using the voltage supplied from the auxiliary battery 60 and supplies it to the power supply circuit 52 and the main microcomputer 53. The power supply circuit 52 generates an operating voltage using the output of the power supply circuit 51 and supplies it to the wireless IC 54.

[0058] The matching circuit 56 and antenna 57 of the control device 50 represent a physical interface for converting the signal output by the wireless IC 54 into radio waves and radiating them into space, and for receiving the radio waves that have propagated through space and inputting them into the wireless IC 54.

[0059] The wireless IC 54 of the control device 50 receives battery monitoring information or fault diagnosis information from the wireless IC 46 of the monitoring device 40 and transmits the information to the main microcomputer 53 of the control device 50. The wireless IC 54 on the control device 50 side also receives data transmitted from the main microcomputer 53 and transmits it to the wireless IC 46 of the monitoring device 40. The wireless IC 54 represents a communication device that controls the communication data size, communication format, schedule, error detection, etc. between the monitoring device 40 and the control device 50.

[0060] The main microcomputer 53 of the control device 50 uses information such as the voltage and temperature of the battery cells 22 transmitted from the wireless IC 46 to calculate the SOC and diagnostic information, which are indicators of the state of the battery cells 22, and transmits these to the host ECU 16. The main microcomputer 53 controls the ignition on / off state and switching of the equalization control.

[0061] The main microcomputer 53 transmits information such as control signals to the monitoring device 40 by wireless communication via the wireless ICs 46 and 54, thereby controlling the operating state of the monitoring device 40. The sub-microcomputer 55 of the control device 50 monitors data exchanged between the wireless IC 54 and the main microcomputer 53, and monitors the operating state of the main microcomputer 53. The sub-microcomputer 55 may also monitor the operating state of the wireless IC 54.

[0062] In the present embodiment, an example has been shown in which the control device 50 includes a sub-microcomputer 55, and the sub-microcomputer 55 monitors data exchanged between the wireless IC 54 and the main microcomputer 53 and monitors the operating state of the main microcomputer 53. However, the configuration of the control device 50 is not limited to this example. For example, the control device 50 does not need to include the sub-microcomputer 55.

[0063] As mentioned above, if the microcontroller 45 is not implemented in the monitoring device 40, the main microcontroller 53 of the control device 50 may manage the battery monitoring information acquisition schedule, fault diagnosis information acquisition schedule, or communication schedule of the monitor IC 44 instead of the microcontroller 45.

[0064] In the present embodiment, an example has been shown in which the main microcomputer 53 of the control device 50 calculates the SOC and diagnostic information, which are indicators of the state of the battery cells 22, using information such as the voltage and temperature of the battery cells 22 transmitted from the wireless IC 46, and transmits the information to the host ECU 16. However, the calculation of the battery information is not limited to this example.

[0065] For example, the microcomputer 45 of the monitoring device 40 may use information such as the voltage and temperature of the battery cell 22 acquired by the monitor IC 44 to calculate the SOC or diagnostic information that are indicators of the state of the battery cell 22, and transmit the calculation results to the wireless IC 54 of the control device 50. In addition, the microcomputer 45 of the monitoring device 40 may use the calculation results to diagnose an abnormality in the battery cell 22 or the monitor IC 44, and may transmit the abnormality diagnosis results to the wireless IC 54 of the control device 50.

[0066] Furthermore, information such as the voltage and temperature of the battery cells 22 acquired by the monitor IC 44 of the monitoring device 40 may be calculated by the wireless IC 46 of the monitoring device 40. Furthermore, information such as the voltage and temperature of the battery cells 22 acquired by the monitor IC 44 of the monitoring device 40 may be calculated by the wireless IC 54 of the control device 50. In addition, the microcomputer 45 of the monitoring device 40 may use the calculation results to diagnose an abnormality in the battery cells 22 and may transmit the results of the abnormality diagnosis to the wireless IC 54 of the control device 50.

[0067] <Wireless communication> Next, wireless communication between the monitoring device 40 and the control device 50 will be described with reference to Figures 4 to 11. In the battery monitoring system 1 of this embodiment, multiple monitoring devices 40 are connected in a star network configuration with the control device 50 at the center, enabling packet communication. In this battery monitoring system 1, the number of communication nodes is three or more.

[0068] The control device 50 establishes communication individually with each of the multiple monitoring devices 40 and wirelessly communicates information with them. The following describes wireless communication between one control device 50 and one monitoring device 40, but the control device 50 executes similar processing with all of the multiple monitoring devices 40.

[0069] As shown in FIG. 5, the monitoring device 40 and the control device 50 execute a communication establishment process in S10. The communication establishment process is performed, for example, when the monitoring device 40 and the control device 50 are started up. When starting the vehicle 10, the user turns the ignition switch from off to on, at which time a start-up signal is sent to the control device 50. When the control device 50 starts up, a communication establishment process is executed between the control device 50 and all the monitoring devices 40. Note that the communication establishment process is a process required for unicast communication UC, but is not required for broadcast communication BC. If the communication establishment process is successful, the control device 50 continues the periodic communication process with the monitoring devices 40 with which communication was established in S20 of FIG. 5.

[0070] 6, the communication establishment process is divided into a connection establishment process shown in S11 and a pairing process shown in S12. The monitoring device 40 and the control device 50 execute the connection establishment process in S11. The connection establishment process is performed by the monitoring device 40 requesting a connection in S11a.

[0071] The monitoring device 40 transmits a connection request packet to the control device 50 in S11a, and the control device 50 accepts the connection request packet in S11b. When the monitoring device 40 executes an advertising operation, the connection request packet is called an advertisement packet. The connection request packet includes ID information of the monitoring device 40 itself and the control device 50. The monitoring device 40 periodically transmits the connection request packet until the connection establishment is completed.

[0072] When the control device 50 detects the monitoring device 40 by performing a connection acceptance operation and receiving a connection request packet, in S11c, it transmits a connection packet in response to the detected monitoring device 40. When the monitoring device 40 receives the connection packet, it can recognize that a connection has been established with the control device 50. This allows the target monitoring device 40 to establish a connection with the control device 50. Once the connection has been established, the monitoring device 40 stops transmitting the connection request packet.

[0073] After the connection establishment process is completed, pairing process is executed next. The pairing process is a process for performing encrypted data communication, and includes a process of exchanging unique information as shown in S12a and S12b. In this exchange process, unique information held by each device is exchanged. After the exchange process in S12a and S12b is completed, encryption becomes possible using the exchanged unique information. The unique information is, for example, key information or information for generating a key. This completes the communication establishment process shown in S10 of FIG. 5.

[0074] When the monitoring device 40 and the control device 50 complete the communication establishment process shown in S10 of Fig. 5, they can execute the periodic communication process shown in S20 of Fig. 5. As shown in Fig. 7, the control device 50 transmits request information to the monitoring device 40 with which the connection process has been completed in S21. The control device 50 transmits the request information including, for example, a request to acquire battery monitoring information and / or fault diagnosis information of the monitor IC 44, and a request to transmit the acquired information.

[0075] When the wireless IC 46 of the monitoring device 40 receives the request information, in S22 it transmits an instruction to acquire battery monitoring information to the monitor IC 44. The wireless IC 46 of this embodiment transmits the acquisition request to the monitor IC 44 via the microcomputer 45.

[0076] When the monitor IC 44 receives the acquisition instruction, it executes the sensing process in S23. When executing sensing, the monitor IC 44 acquires the temperature of each battery cell 22 as battery monitoring information along with the cell discrimination signal via the selection circuit 47. The monitor IC 44 functions as the acquisition unit 40a. The monitor IC 44 performs fault diagnosis of its own circuit.

[0077] Next, in S24, the monitor IC 44 transmits the acquired battery monitoring information and fault diagnosis information to the wireless IC 46 via the microcomputer 45. If the microcomputer 45 is not configured, the monitor IC 44 transmits the information directly to the wireless IC 46.

[0078] When the wireless IC 46 receives the information acquired by the monitor IC 44, in S25 it generates response data including battery monitoring information and fault diagnosis information for the control device 50 and transmits the response data to the control device 50. In S26, the control device 50 receives the response data.

[0079] The control device 50 refers to the response data received in S30 and executes a predetermined process based on the response data. In S30, the control device 50 executes a predetermined process based on, for example, a plurality of pieces of battery monitoring information acquired during a predetermined period.

[0080] For example, the control device 50 of this embodiment obtains the cell voltage value from multiple pieces of battery monitoring information obtained from the monitoring device 40 during a predetermined period, and further obtains the cell current value through the current sensor 17 connected in series to the battery cell 22. The control device 50 estimates the internal resistance and open-circuit voltage of the battery cell 22 based on these cell voltages and cell currents.

[0081] The control device 50 can calculate the SOH based on the estimated internal resistance. SOH is an abbreviation for States Of Health and is an index that indicates the deterioration state of a battery. The control device 50 can also detect an abnormality in a battery cell 22 by comparing the open-circuit voltages of the battery cells 22 and determining whether they are within a certain range. In this embodiment, the "predetermined processing" performed by the control device 50 is mainly performed by the main microcomputer 53, but may also be performed by another component within the control device 50, or by the microcomputer 45 or wireless IC 46 of the monitoring device 40.

[0082] In this embodiment, the control device 50 estimates the internal resistance and open-circuit voltage of the battery cell 22 based on the cell voltage and cell current. The control device 50 calculates the SOH based on the estimated internal resistance and open-circuit voltage. However, the estimation of the internal resistance, the open-circuit voltage, and the calculation of the SOH are not limited to this example. For example, the microcomputer 45 of the monitoring device 40 may perform some or all of the operations of estimating the internal resistance, the open-circuit voltage, and the calculation of the SOH. Furthermore, the wireless IC 46 of the monitoring device 40 may perform some or all of the operations of estimating the internal resistance, the open-circuit voltage, and the calculation of the SOH.

[0083] The predetermined processing executed by the control device 50 is not limited to the above processing, and may include processing executed each time battery monitoring information is acquired. For example, the control device 50 may execute an abnormality diagnosis based on the fault diagnosis information each time information is acquired from the monitoring device 40. The abnormality diagnosis may be executed periodically. For example, the control device 50 may transmit the acquired information to the host ECU 16 each time battery monitoring information is acquired. Note that the control device 50 may also transmit all information received during a predetermined period to the host ECU 16.

[0084] Although the example in which the monitoring device 40 acquires the battery monitoring information based on an acquisition request from the control device 50 has been described, the present invention is not limited to this. The monitoring device 40 may autonomously acquire the battery monitoring information and transmit the battery monitoring information it holds to the control device 50 based on a transmission request from the control device 50. When this sequence is used, the processing of S22 is not necessary.

[0085] In this embodiment, an example has been shown in which the battery monitoring system 1 has a plurality of monitoring devices 40 connected in a star network with a control device 50 at the center, enabling packet communication. However, the network topology between the control devices 50 and the monitoring devices 40 is not limited to this example.

[0086] The control device 50 and the monitoring device 40 may form a mesh network. In this network configuration, a plurality of monitoring devices 40 are grouped and connected by wire to form a single network, and the grouped plurality of monitoring devices 40 function as a single device. The mesh network in this case is configured with a topology in which the control device 50 and a plurality of groups of monitoring devices 40 form a network. This network configuration may also be applied. The control device 50 and the monitoring device 40 may also be connected in a daisy chain network. A network may also be configured by mixing at least two or more of a star network, a mesh network, and a daisy chain network. While the control device 50 and the monitoring device 40 form a wireless connection network in the illustrated example, a wired connection network may also be mixed. Thus, the network topology of the control device 50 and the monitoring device 40 is not particularly limited.

[0087] In this embodiment, when starting the vehicle 10, the user turns the ignition switch from off to on, and at this time, a start-up signal is sent to the control device 50. In this manner, an example has been shown in which the control device 50 is started up when the ignition switch is turned on from off. In other words, when the ignition switch is in the off state, the control device 50 is in a sleep state. However, the operation of the control device 50 when the ignition switch is in the off state is not limited to this example.

[0088] For example, even if the ignition switch is in the OFF state, the control device 50 may be activated. In this case, the control device 50 may maintain the established connection with the monitoring device 40.

[0089] <Periodic processing> Next, the periodic communication process will be described with reference to Figures 8 and 9. When executing the periodic communication process shown in S20 described above, the control device 50 and the multiple monitoring devices 40 periodically execute unicast communication UC and broadcast communication BC. Unicast communication UC refers to a communication method in which the control device 50 designates one of the multiple monitoring devices 40 to execute packet data communication. When executing unicast communication UC, if the monitoring device 40 detects a packet from the network, it checks the ID information contained in the packet and, if it determines that the packet is addressed to itself, accepts the packet, but if it is not addressed to itself, discards the packet.

[0090] Broadcast communication BC refers to a communication method in which the control device 50 uses a broadcast address to simultaneously transmit data to each monitoring device 40 connected to the network. In this case, all monitoring devices 40 detect a packet on the network, refer to the packet, and then accept the packet.

[0091] 8 shows the time allocation of transmission TX / reception RX in a communication cycle T during which the control device 50 performs wireless communication with n other monitoring devices 40 (401...40n). Hereinafter, when it is necessary to individually represent the monitoring devices 40, the monitoring devices 40 will be referred to by a subscripted reference symbol "401...40n." In this embodiment, as shown in FIG. 8, the control device 50 performs unicast communication UC with each monitoring device 40, and then broadcast communication BC to all monitoring devices 40, thereby synchronizing the timing of cell voltage acquisition by each monitoring device 40. Below, the processing content will be described assuming that the series of unicast communication UC and broadcast communication BC processes are one cycle of communication cycle T.

[0092] 9 shows the processing of the control device 50, the wireless IC 54 of the control device 50 sets a communication cycle T for communication with the multiple monitoring devices 40 using the function of the cycle setting unit 50a in S31. In an initial state, the control device 50 sets the communication cycle T so that data communication with the multiple monitoring devices 40 completes one cycle. This communication cycle T is set to a predetermined time, for example, between several tens of msec and several hundreds of msec, which is the combined time of unicast communication UC between the multiple monitoring devices 40 and broadcast communication BC transmitted to all monitoring devices 40. The communication cycle T may be stored and managed in advance in a table or the like in a memory mounted on the wireless IC 54 of the control device 50 or the wireless IC 46 of the monitoring device 40, or may be calculated by an arithmetic program using a function.

[0093] In S32, the wireless IC 54 of the control device 50 sets the order of unicast communications UC to each of the multiple monitoring devices 40 and broadcast communications BC to the multiple monitoring devices 40 during one communication cycle T, and instructs the multiple monitoring devices 40 in the set order. From the viewpoint of functional safety, it is desirable for the control device 50 to organize the order of transmission and reception of communication data, correspondence relationships, etc.

[0094] In the following example, a form in which unicast communication UC is performed and then broadcast communication BC is performed within one communication cycle T is illustrated, but the reverse order is also possible. In parallel, the main microcomputer 53 of the control device 50 determines the timing for acquiring battery monitoring information in S33, and the wireless IC 54 of the control device 50 issues instructions in S34 using the function of the instruction unit 50b, including instructions to each of the multiple monitoring devices 40 to acquire battery monitoring information via unicast communication UC within one communication cycle T, and instructions to the multiple monitoring devices 40 regarding the timing for acquiring battery monitoring information via broadcast communication BC. Here, an example has been described in which the control device 50 instructs the monitoring devices 40 regarding the timing for acquiring battery monitoring information, but it may also instruct them to acquire fault diagnosis information.

[0095] A specific example is shown in Fig. 10. After the wireless IC 54 of the control device 50 executes the communication establishment process described above with the n monitoring devices 401...40n, it transmits a battery monitoring control command via periodic data communication as shown in Fig. 10. The wireless IC 54 of the control device 50 transmits instructions to each of the multiple monitoring devices 40 via unicast communication UC, and issues the battery monitoring control command via S1TX to SnTX. The battery monitoring control command here includes instruction information such as ID information of the wireless IC 46 of each monitoring device 40, an instruction to acquire battery monitoring information such as cell voltage, an instruction to acquire temperature information of the battery cells 22, and an instruction to perform fault diagnosis.

[0096] The wireless IC 45 of each monitoring device 401...40n transmits the delivery confirmation to the control device 50 via unicast communication UC as a function of the delivery confirmation transmitter 40b. The monitor IC 44 of the monitoring device 40 acquires battery monitoring information such as cell voltage and temperature information instructed in the previous or any previous communication cycle T, and stores this information in the memory of the microcomputer 45 or the wireless IC 46. The monitoring devices 401...40n transmit the battery monitoring information previously stored in memory in addition to the delivery confirmation for the response data. The monitoring devices 401...40n may also transmit temperature information and fault diagnosis information for the battery cells 22 if stored in memory.

[0097] Here, delivery confirmation refers to data that can be received by the wireless IC 54 of the control device 50 to confirm "which battery monitoring control command was received by each monitoring device 401...40n" or "whether the battery monitoring information sent from each monitoring device 401...40n was obtained in the latest communication cycle T, or in the previous or earlier communication cycle T."

[0098] The wireless IC 54 of the control device 50 receives the delivery confirmation in S1RX to SnRX and also receives the information included in the response data. This received information indicates response data corresponding to the instruction content given by the wireless IC 54 of the control device 50 previously.

[0099] When the wireless IC 54 of the control device 50 receives delivery confirmations from the multiple monitoring devices 40, it checks the order in which it received the information, such as the battery monitoring information, and executes broadcast communication BC. By receiving delivery confirmations from the multiple monitoring devices 40, the wireless IC 54 can reliably confirm that the information has been delivered to the multiple monitoring devices 40. The information delivered from these multiple monitoring devices 40 will be the same type of information, but it does not necessarily have to be the same.

[0100] Thereafter, the wireless IC 54 of the control device 50 issues a battery monitoring control command via S1BC to SnBC in the broadcast communication BC. The battery monitoring control command here includes instruction information for instructing the timing of acquiring battery monitoring information such as cell voltage or temperature information or for instructing fault diagnosis. The control device 50 checks the order in which the multiple monitoring devices 40 acquire information such as battery monitoring information such as cell voltage, and the content of the received information, and then carries out the broadcast communication BC.

[0101] The control device 50 may use a battery monitoring control command to broadcast instructions to each of the monitoring devices 401...40n regarding the timing for simultaneous acquisition. The battery monitoring control command here may instruct a timer that measures the timing of transmission and reception of communications to be reset, and may also instruct a relative time, such as a predetermined time (e.g., 5 ms) after the reset instruction. On the other hand, the battery monitoring control command may also instruct each of the monitoring devices 401...40n to synchronize the times managed by the timers built into the wireless ICs 45 to the same time.

[0102] This makes it possible to minimize the effect of timer setting errors until each monitoring device 40 actually acquires the cell voltage, even after an instruction for unicast communication UC has been issued, and to prevent deviations in the timing of acquiring the cell voltage among multiple monitoring devices 40. Note that the timings may be set differently from each other.

[0103] As described above, the host ECU 16 is connected to a current sensor 17 that measures the current flowing through the battery pack 12. The control device 50 preferably instructs the multiple monitoring devices 40 via broadcast communication BC to acquire the voltage of the battery pack 12 in accordance with the timing of measuring the current flowing through the battery pack 12. This allows information on the current flowing through the battery pack 12 and information on the voltage of the battery cells 22 to be acquired in a synchronized manner. Because the power load on the battery pack 12 fluctuates from moment to moment, it is important to determine the power consumption over a specified period of time. According to this embodiment, current information and voltage information can be acquired in a synchronized manner, making it possible to estimate the power consumption over a certain period of time as accurately as possible.

[0104] In the broadcast communication BC, the wireless IC 54 of the control device 50 transmits packets without attaching ID information of the wireless IC 46 of the monitoring device 40. This is done to reduce the transmission / reception error rate due to data corruption or to shorten the internal processing time of the main microcomputer 53 or wireless IC 54 on the control device 50 side.

[0105] The frequency band used in the broadcast communication BC may be set to a frequency band outside of a predetermined frequency band. The aforementioned predetermined frequency band refers to, for example, a frequency band predetermined to be used for each WiFi channel. The control device 50 measures, for example, the number of communication errors, the number of retransmissions of communication data, and received signal strength indicator (RSSI) between each of the multiple monitoring devices 40 in the aforementioned installation environment. Based on this communication performance information, the control device 50 may narrow down frequency bands with good communication performance in advance and store them in the internal memory of the wireless IC 54. The control device 50 may then select a frequency band from the stored frequency bands for communication. RSSI stands for Received Signal Strength Indicator.

[0106] In addition, the vehicle 10 may be equipped with a separate external communication means such as a data communication module (DCM), and may be configured to enable data communication by communicating with the outside world through this data communication module. DCM stands for Data Communication Module. In the case of such a vehicle 10, it is desirable to perform the broadcast communication BC using a frequency band different from the frequency band used by the data communication module.

[0107] As shown in Figure 8, it is desirable to set the frequency band fbc used in the broadcast communication BC so as to exclude the frequency bands fuc1 and fuc2 used in the unicast communications UC immediately before and after the broadcast communication BC. This is to eliminate the influence of residual reflected waves as much as possible. In the example of Figure 8, the frequency bands fuc1, fbc, and fuc2 may be set to different bands from each other, or the frequency bands fuc1 and fuc2 may be set to bands that include the same area but differ by the frequency band fbc.

[0108] Although the frequency bands fuc1 and fuc2 used in the unicast communications UC before and after the broadcast communication BC are shown to be different from the frequency band fbc used in the broadcast communication BC, the frequency band fbc used in the broadcast communication BC may differ only from the frequency band (e.g., frequency band fuc1) used in the previous communication (e.g., unicast communication UC), and may include the same band as the frequency band (e.g., frequency band fuc2) used in the subsequent communication (e.g., unicast communication UC).

[0109] This configuration reduces the influence of residual reflected waves in broadcast communication BC without delivery confirmation. This improves the communication success rate of broadcast communication BC. Since real-time battery monitoring information is important for vehicle safety, in this embodiment, the timing of acquiring battery monitoring information is suitably synchronized by broadcast communication BC.

[0110] The frequency band fbc used in the broadcast communication BC is different only from the frequency band (e.g., frequency band fuc2) used in the subsequent communication (e.g., unicast communication UC), and may include the same band as the frequency band (e.g., frequency band fuc1) used in the previous communication (e.g., unicast communication UC). By using a frequency band fbc different from the frequency band used in the broadcast communication BC and the subsequent communication (e.g., unicast communication UC), interference with the subsequent communication can be avoided even if a delay occurs in the communication cycle due to a communication failure, an operating clock error, or the like.

[0111] Additionally, for example, when the order of broadcast communication BC and unicast communication UC is set for each communication cycle T, broadcast communication BC may be executed multiple times in succession without unicast communication UC in between in two adjacent communication cycles T. In this case, too, it is desirable to use different frequency bands for the previous and subsequent broadcast communication BC.

[0112] When the wireless IC 45 of the monitoring devices 401 to 40n receives the broadcast communication BC, it reads the instruction information from the control device 50 at Sa in FIG. 10 and adjusts the acquisition timing using a built-in timer. When the wireless IC 45 determines that the acquisition timing has passed, it issues a battery monitoring control command to the monitor IC 44 at Sb. When the monitor IC 44 accepts the battery monitoring control command, it executes battery monitoring control at Sc and acquires the cell voltage. The monitor IC 44 then responds with battery monitoring information including the cell voltage to the wireless IC 45 of the control device 50 at Sd.

[0113] For example, if the monitor IC 44 includes a timer, the wireless IC 45 may issue a battery monitoring control command to the monitor IC 44 immediately after receiving instruction information from the wireless IC 54, and the monitor IC 44 may adjust the acquisition timing at Sa.

[0114] When the wireless IC 45 of the monitoring device 40 receives the battery monitoring information from the monitor IC 44, it transmits the battery monitoring information to the wireless IC 54 of the control device 50. Packet transmission is performed at the timing of executing unicast communication UC in the communication cycle T after the end of broadcast communication BC in the previous communication cycle T. In this way, the communication process is repeated for each communication cycle T.

[0115] <Operations when communication is interrupted or cut off> The process when communication is established and cut off will now be described. When the ignition switch is turned off by the user, the input of the activation signal to the control device 50 is cut off. The control device 50 cuts off the wireless communication.

[0116] Furthermore, for example, depending on the placement environment of the battery pack 11 and the mounting environment of the monitoring device 40 and the control device 50 relative to the housing 30, diffuse reflection of the radio waves used for communication between the monitoring device 40 and the control device 50 may occur.

[0117] For example, in response to recent demands for lower heights, if the in-vehicle battery pack 11 is housed in a flat housing 30 as shown in Fig. 2 or is exposed to a harsh environment, it may not be possible to ensure sufficient propagation space for radio waves in a specific direction, such as the Z direction in Fig. 2, and radio waves may be repeatedly diffused inside the housing 30. In this case, the deterioration of the communication environment may cause communication between the control device 50 and the monitoring device 40 to be interrupted.

[0118] If communication between the control device 50 and a certain monitoring device 40 is lost, the control device 50 attempts to re-establish communication with the monitoring device 40 as shown in Figure 11 while maintaining communication with the other monitoring device 40.

[0119] <Re-establishing communication> The control device 50 performs a re-communication establishment process when communication is lost with one of the monitoring devices 40 (e.g., 401). When communication between the control device 50 and the monitoring device 40 is lost, the control device 50 executes the re-communication establishment process shown in Fig. 11 periodically or when a predetermined condition is satisfied. For example, the re-communication establishment process may be triggered by a failure to acquire battery monitoring information from the monitoring device 40.

[0120] In S101, the control device 50 determines whether there is a monitoring device 40 with which communication needs to be established. If data communication is being performed with all of the monitoring devices 40, the control device 50 determines in S101 that there is no monitoring device 40 with which a communication connection needs to be established, and terminates the re-communication establishment process. For example, when communication with some of the monitoring devices 40 is disconnected, the control device 50 determines that there is a monitoring device 40 with which reconnection needs to be established.

[0121] The control device 50 may determine whether or not there is a monitoring device 40 that needs to be reconnected, for example, based on the acquired battery monitoring information. Specifically, the control device 50 determines that reconnection is necessary when battery monitoring information such as cell voltage cannot be acquired a predetermined number of times or for a predetermined period of time. The control device 50 may also determine whether or not there is a monitoring device 40 that needs to be reconnected, for example, based on communication performance information such as the number of communication errors, the number of data retransmissions, and received signal strength indicator (RSSI).

[0122] Alternatively, multiple monitoring devices 40 may determine communication history information such as the number of communication errors, the number of data retransmissions, and received signal strength, and transmit this communication history information to the control device 50, which may then determine whether or not there are any monitoring devices 40 that require reconnection by examining the communication history information contained in the response data transmitted from the multiple monitoring devices 40.

[0123] When the control device 50 determines in step S101 that there is a monitoring device 40 with which a communication connection is required, it re-establishes communication when a connection is required in S102. The re-establishment of communication process shown in S102 is the same as the communication establishment process shown in S10 of Fig. 5. The control device 50 performs the communication establishment process with the monitoring device 40 through the connection establishment process in S11 and the pairing process in S12.

[0124] 11, the control device 50 determines whether communication connections have been established with all of the monitoring devices 40 during steady communication, and ends the cycle change process if communication connections with all of the monitoring devices 40 have been completed. Conversely, if communication connections with all of the monitoring devices 40 have not been established, the process returns to S101, where it determines whether there are any monitoring devices 40 that require reconnection, and if it determines that there are any in S101, it executes communication establishment processing with the other monitoring devices 40. This allows the control device 50 to continue establishing communication with all of the monitoring devices 40.

[0125] <Comparative examples and problems> Below, a comparative example of this embodiment and its problems will be described. If the control device 50 executes multiple broadcast communications BC with multiple monitoring devices 40 within one communication cycle T, it is likely that it will take a long time to transmit commands. There is a risk that the communication cycle T for acquiring battery monitoring information will not satisfy the strict cycle requirements imposed by the system. For example, if a wait time of several hundred μs to several tens of ms is set between multiple communications, assuming that the communication management data required for communication is several tens to several hundred bytes and the communication speed is 500 kHz, the wait time will be several ms even at the fastest speed. For example, if the communication cycle T for acquiring battery monitoring information from the system is set to several to several tens of ms, the wait time will occupy a significant proportion of the time, making it impossible to satisfy the cycle requirements.

[0126] Furthermore, even if the control device 50 transmits a broadcast communication BC without a delivery confirmation multiple times to the monitoring devices 40, it does not guarantee that all monitoring devices 40 will receive the communication. This means that it is not possible to guarantee that battery monitoring information for all battery cells 22 will be acquired, and the monitoring device 40 will not be able to achieve its intended monitoring purpose. To increase the reliability of communication, the number of retransmissions of the broadcast communication BC must be increased. However, increasing the number of retransmissions makes it even more difficult to satisfy the aforementioned periodicity requirement. Furthermore, broadcast communication BC is typically not encrypted, which makes it vulnerable to malicious attacks or malicious eavesdropping from outside. For this reason, it is not desirable to send all instructions via broadcast communication BC.

[0127] <Summary of this embodiment> According to this embodiment, during one communication cycle T, instructions are given including, by unicast communication UC, instructions to each of the multiple monitoring devices 40 (401...40n) to acquire battery monitoring information, and by broadcast communication BC, instructions to the multiple monitoring devices 40 regarding the timing of acquiring battery monitoring information, and unicast communication UC, which allows delivery confirmation, and broadcast communication BC, which does not allow delivery confirmation, are used in combination.

[0128] Therefore, it is possible to minimize the number of broadcast communications BC while satisfying the required cycle requirements and guaranteeing acquisition of battery monitoring information related to the battery pack 12. This increases the reliability of acquiring information such as battery monitoring information. Since the number of times that broadcast communications BC are executed within one communication cycle T is minimized to, for example, once, it is possible to increase the security of communication.

[0129] The control device 50 executes unicast communication UC and broadcast communication BC to each monitoring device 40, and can instruct the timing of acquiring battery monitoring information at this time, thereby minimizing discrepancies in the timing of acquiring battery monitoring information among multiple monitoring devices 40. This makes it possible to acquire battery monitoring information under the same environmental conditions, making it easier to accurately estimate various characteristics over a certain period of time.

[0130] (Second embodiment) The second embodiment will be described with reference to Fig. 12. In the first embodiment, the control device 50 executes a unicast communication UC and then a broadcast communication BC, and acquires battery monitoring information at the battery monitoring control timing instructed by the broadcast communication BC. In the present embodiment, an alternative method for setting the timing for acquiring battery monitoring information will be described.

[0131] The control device 50 may instruct the timing of battery monitoring control by the unicast communication UC. The battery monitoring control timing here may be instructed as a relative time, such as a predetermined time (for example, 5 ms) after the transmission timing of the unicast communication UC as a starting point, or the control device 50 may instruct as an absolute time a time managed by a timer built into the wireless IC 45 of each of the monitoring devices 401...40n.

[0132] In the first embodiment, the broadcast communication BC is executed after the unicast communication UC is executed, but conversely, the broadcast communication BC may be executed before the unicast communication UC is executed.

[0133] 12 shows the processing details of the monitoring device 40 when receiving an instruction from the control device 50. The wireless IC 54 of the control device 50 executes unicast communication UC and broadcast communication BC once each in one communication cycle T, and transmits a battery monitoring control command to the monitoring device 40. The wireless IC 46 of the monitoring device 40 receives the communication data included in the unicast communication UC and the broadcast communication BC in S201. During this time, the wireless IC 46 resets a timer and starts counting when it receives the previous communication (for example, the unicast communication UC), and measures the time until it receives the subsequent communication (for example, the broadcast communication BC).

[0134] In S202, the wireless IC 46 of the monitoring device 40 determines whether the timing of the battery monitoring control command in the broadcast communication BC deviates from the timing of the battery monitoring control command in the unicast communication UC by a predetermined threshold value or more.

[0135] If the difference is greater than a predetermined threshold, the communication quality of the broadcast communication BC may be poor and the communication data may be unreliable. On the other hand, the unicast communication UC is encrypted, allowing instructions to be properly transmitted from the control device 50 to the monitoring device 40. Therefore, if the monitoring device 40 determines in S202 that the difference is greater than a predetermined threshold, it trusts and confirms the instructions in the unicast communication UC in S203 and discards the instructions included in the received broadcast communication BC. Then, the monitoring device 40 sets the timing for acquiring battery monitoring information based on the instructions in the unicast communication UC in S205, and when the acquisition timing arrives, it determines YES in S206, and then acquires the battery monitoring information in S207.

[0136] On the other hand, if the wireless IC 46 of the monitoring device 40 determines in S202 that the deviation is not greater than the predetermined threshold, it determines that the wireless communication quality is good. In this case, it can be assumed that the reliability of both the unicast communication UC and the broadcast communication BC is high. Because the monitoring device 40 acquires the battery monitoring information after receiving these communications, acquiring the battery monitoring information immediately after receiving the information facilitates accurate synchronization among multiple monitoring devices 40. For this reason, the wireless IC 46 of the monitoring device 40 may check the received content of the later communication in one communication cycle T in S204 and set the timing for acquiring the battery monitoring information in S205.

[0137] For example, if unicast communication UC and broadcast communication BC are performed in this order during one communication cycle T, the wireless IC 54 of the control device 50 transmits both the unicast communication UC and the broadcast communication BC together with the timing of battery monitoring information acquisition. The wireless IC 46 of the monitoring device 40 determines whether there is a difference in the reception timing of the unicast communication UC and the broadcast communication BC by more than a predetermined threshold, and checks the timing of battery monitoring information acquisition based on this determination result. This allows the timing of battery monitoring information acquisition by the monitor ICs 44 of multiple monitoring devices 40 to be synchronized.

[0138] Conversely, even when communications are performed in the order of broadcast communication BC and unicast communication UC within one communication cycle T, the wireless IC 54 of the control device 50 transmits the broadcast communication BC and the unicast communication UC together with the acquisition timing of the battery monitoring information. The wireless IC 46 of the monitoring device 40 then checks the acquisition timing of the battery monitoring information included in at least the unicast communication UC, which is the later communication. This makes it easy to synchronize the acquisition timing of the battery monitoring information between the monitor ICs 44 of multiple monitoring devices 40.

[0139] According to this embodiment, the monitoring device 40 checks the content of subsequent communications within one communication cycle T and sets the timing for acquiring battery monitoring information, which makes it easy to synchronize the timing for acquiring battery monitoring information among multiple monitoring devices 40. This allows battery monitoring information to be acquired under the same environmental conditions, making it easier to accurately estimate various characteristics.

[0140] <Functional Description> Finally, the characteristic functions of the control device 50 and the monitoring device 40 shown in the first or second embodiment will be summarized with reference to Fig. 13. The control device 50 has a function as a cycle setting unit 50a that sets a communication cycle T for one cycle of communication between the control device 50 and the multiple monitoring devices 40.

[0141] The control device 50 has a function as an instruction unit 50b that issues instructions including instructions to each of the multiple monitoring devices 40 to acquire battery monitoring information by unicast communication UC and instructions to the multiple monitoring devices 40 regarding the timing of acquiring battery monitoring information by broadcast communication BC during one communication cycle T. The control device 50 has a function as an order setting unit 50c that sets the order of the unicast communication UC to each of the multiple monitoring devices 40 and the broadcast communication BC to the multiple monitoring devices 40 during one communication cycle T.

[0142] The monitoring device 40 has a function as an acquisition unit 40a that acquires battery monitoring information by setting the acquisition timing of the battery monitoring information from the acquisition timing instructed by the later-received communication of unicast communication UC or broadcast communication BC within the communication cycle T. After receiving an instruction to acquire battery monitoring information from the control device 50, the monitoring device 40 has a function as a delivery confirmation sending unit 40b that transmits the battery monitoring information and a delivery confirmation for the instruction to the control device 50 by unicast communication UC. Note that these characteristic functions are merely examples, and the control device 50 or the monitoring device 40 also has various other functions as described in the above-described embodiments.

[0143] (Other embodiments) The present invention is not limited to the above-described embodiment, and the following modifications or extensions are possible. The control device 50 may include ID information and battery monitoring control timing for each monitoring device 40 in the communication data of the broadcast communication BC. Even when the broadcast communication BC is used, the battery monitoring control timing for each monitoring device 40 can be determined individually. Although the battery monitoring system 1 has been described as being configured with the control device 50 and multiple monitoring devices 40, it can also be applied to a configuration in which the functions of the control device 50 are provided in the upper ECU 16.

[0144] The control device 50, monitoring device 40, host ECU 16, and methods described herein may be implemented by a special-purpose computer provided by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control device 50, monitoring device 40, host ECU 16, and methods described herein may be implemented by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits.

[0145] Alternatively, the control device 50, monitoring device 40, host ECU 16, and methods described herein may be implemented by one or more dedicated computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured by one or more hardware logic circuits. Also, the computer program may be stored on a computer-readable non-transitory tangible recording medium as instructions to be executed by the computer.

[0146] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure. [Explanation of symbols]

[0147] In the drawing, 1 indicates a battery monitoring system, 12 indicates a battery pack (battery), 16 indicates a host ECU (control device), 22 indicates a battery cell (battery), 40, 401...40n indicate monitoring devices, 40a indicates an acquisition unit, 40b indicates a delivery confirmation sending unit, 50 indicates a control device, 50a indicates a period setting unit, and 50b indicates an instruction unit.

Claims

1. a plurality of monitoring devices (40, 401...40n) for acquiring battery monitoring information used to monitor the states of the batteries (12, 22); a control device (50) that acquires the battery monitoring information by wirelessly communicating with the plurality of monitoring devices and executes predetermined processing; There are multiple types of battery monitoring information, The control device a command unit (50b) that issues commands including commands to each of the plurality of monitoring devices via unicast communication to acquire the battery monitoring information of a specified type from among a plurality of types during a communication cycle for communication with the plurality of monitoring devices, and commands to the plurality of monitoring devices via broadcast communication regarding the timing for acquiring the battery monitoring information.

2. The control device includes a fault diagnosis acquisition request unit that requests acquisition of fault diagnosis information, The battery monitoring system according to claim 1 , wherein the monitoring device includes a fault diagnosis information acquisition unit that acquires the fault diagnosis information by performing a fault diagnosis in response to the request for acquiring the fault diagnosis information.

3. a plurality of monitoring devices (40, 401...40n) for acquiring battery monitoring information used to monitor the states of the batteries (12, 22); a control device (50) that acquires the battery monitoring information by wirelessly communicating with the plurality of monitoring devices and executes predetermined processing; The control device an instruction unit (50b) that issues instructions including instructions to each of the plurality of monitoring devices by unicast communication to acquire the battery monitoring information and instructions to the plurality of monitoring devices by broadcast communication regarding the timing of acquiring the battery monitoring information, during a communication cycle for communicating with the plurality of monitoring devices; the control device includes an order setting unit (50c) that sets an order of the unicast communication to each of the plurality of monitoring devices and the broadcast communication to the plurality of monitoring devices during the communication cycle, and the instruction unit instructs the plurality of monitoring devices in the order set by the order setting unit; The instruction unit instructs the plurality of monitoring devices on the timing of acquiring the battery monitoring information via the unicast communication.

4. The battery monitoring system of any one of claims 1 to 3, wherein the monitoring device is provided with an acquisition unit (40a) that acquires the battery monitoring information by setting the acquisition timing of the battery monitoring information from the acquisition timing indicated by the later-received communication between the unicast communication and the broadcast communication within the communication cycle.

5. The battery monitoring system of any one of claims 1 to 3, wherein the monitoring device is provided with an acquisition unit (40a) that acquires the battery monitoring information based on the content received via the unicast communication when the timing of reception via the unicast communication differs from the timing of reception via the broadcast communication by more than a predetermined threshold value.

6. The battery monitoring system according to claim 1 , wherein after receiving an instruction to acquire the battery monitoring information, the monitoring device transmits the battery monitoring information and a delivery confirmation for the instruction to the control device via the unicast communication.

7. The battery monitoring system according to claim 6 , wherein the control device, upon receiving the delivery confirmation from the monitoring device, checks the order in which the battery monitoring information was received and then executes the broadcast communication.

8. The battery monitoring system according to claim 1 , wherein the frequency band used in the broadcast communication is set to a frequency band outside a predetermined frequency band.

9. The battery monitoring system according to claim 1 , wherein a frequency band used in the broadcast communication is different from a frequency band used in a communication performed before or after the broadcast communication.

10. the control device is configured to acquire battery voltages as the battery monitoring information from the plurality of monitoring devices; The battery is configured to acquire current information from a current sensor (17) that measures the current flowing through the battery, The battery monitoring system according to claim 1 , wherein the instruction unit instructs the plurality of monitoring devices by the broadcast communication to acquire the voltage of the battery in accordance with a timing of measuring the current.

11. A control device (50) that acquires battery monitoring information used for monitoring the state of a battery by wirelessly communicating with a plurality of monitoring devices that acquire the battery monitoring information and executes predetermined processing, wherein the battery monitoring information is of a plurality of types, a control device comprising: an instruction unit (50b) that issues instructions including instructions to each of the plurality of monitoring devices via unicast communication to acquire the battery monitoring information of a type specified from among a plurality of types during a communication cycle for communicating with the plurality of monitoring devices, and instructions to the plurality of monitoring devices via broadcast communication regarding the timing for acquiring the battery monitoring information.

12. The control device according to claim 11, further comprising a fault diagnosis acquisition request unit that requests the acquisition of fault diagnosis information.

13. A control device (50) that acquires battery monitoring information used for monitoring the state of a battery by wireless communication with a plurality of monitoring devices that acquire the battery monitoring information and executes predetermined processing, an instruction unit (50b) that issues instructions including instructions to each of the plurality of monitoring devices by unicast communication to acquire the battery monitoring information and instructions to the plurality of monitoring devices by broadcast communication regarding the timing of acquiring the battery monitoring information, during a communication cycle for communicating with the plurality of monitoring devices; an order setting unit (50c) that sets an order of unicast communication to each of the plurality of monitoring devices and an order of broadcast communication to the plurality of monitoring devices during the communication cycle; the instruction unit instructs the plurality of monitoring devices in the order set by the order setting unit; The instruction unit is a control device that instructs the plurality of monitoring devices on the timing of acquiring the battery monitoring information by the unicast communication.

14. The instruction unit is configured to receive a delivery confirmation from the monitoring device when the instruction unit instructs the monitoring device, The control device according to claim 11 , wherein, when receiving a delivery confirmation from the monitoring device, the control device checks the order in which the plurality of monitoring devices received the battery monitoring information and then executes the broadcast communication.

15. The control device according to claim 11 , wherein the frequency band used in the broadcast communication is a frequency band outside a predetermined frequency band.

16. The control device according to claim 11 , wherein a frequency band used in the broadcast communication is different from a frequency band used in a communication performed before or after the broadcast communication.

17. The battery monitoring information is configured to acquire battery voltages from the plurality of monitoring devices, The battery is configured to acquire current information from a current sensor (17) that measures the current flowing through the battery, The control device according to claim 11 , wherein the instruction unit instructs the plurality of monitoring devices by the broadcast communication to acquire the voltage of the battery in accordance with the timing of measuring the current.

18. A monitoring device that, upon receiving an instruction from a control device that executes a predetermined process, acquires battery monitoring information used for monitoring a battery state and transmits the battery monitoring information to the control device via wireless communication, There are multiple types of battery monitoring information, the control device includes an instruction unit (50b) that, during a communication cycle for communicating with the plurality of monitoring devices, issues instructions including instructions to each of the plurality of monitoring devices by unicast communication to acquire the battery monitoring information of a type designated from among a plurality of types, and instructions to the plurality of monitoring devices by broadcast communication regarding the timing of acquiring the battery monitoring information; The monitoring device includes an acquisition unit (40a) that acquires the battery monitoring information at the instructed acquisition timing when receiving an acquisition timing instruction from the control device.

19. The control device includes a fault diagnosis acquisition request unit that requests acquisition of fault diagnosis information, The monitoring device according to claim 18 , further comprising a fault diagnosis information acquisition unit that acquires the fault diagnosis information by performing a fault diagnosis in response to the request for acquisition of the fault diagnosis information.

20. A monitoring device that, upon receiving an instruction from a control device that executes a predetermined process, acquires battery monitoring information used for monitoring a battery state and transmits the battery monitoring information to the control device via wireless communication, the control device includes an instruction unit (50b) that issues instructions, including instructions to each of the plurality of monitoring devices by unicast communication to acquire the battery monitoring information and instructions to the plurality of monitoring devices by broadcast communication regarding the timing of acquiring the battery monitoring information, during a communication cycle for communicating with the plurality of monitoring devices; an acquisition unit (40a) that acquires the battery monitoring information at the instructed acquisition timing when receiving an acquisition timing instruction from the control device; The acquisition unit is a monitoring device that acquires the battery monitoring information by setting the acquisition timing of the battery monitoring information from the acquisition timing indicated by the communication received later, either the unicast communication or the broadcast communication, within the communication cycle.

21. 21. The monitoring device according to claim 18, wherein the acquisition unit acquires the battery monitoring information based on the content received via the unicast communication when the timing of reception via the unicast communication and the timing of reception via the broadcast communication differ by a predetermined threshold or more.

22. 21. The monitoring device according to claim 18, further comprising a delivery confirmation sending unit (40b) that, after receiving an instruction to acquire the battery monitoring information, sends the battery monitoring information and a delivery confirmation for the instruction to the control device via the unicast communication.

23. A program to be executed by a control device that acquires battery monitoring information used for monitoring a state of a battery by wirelessly communicating with a plurality of monitoring devices and executes predetermined processing, There are multiple types of battery monitoring information, A control device (50) a procedure in which, during a communication cycle for communicating with the plurality of monitoring devices, an instruction unit (50b) issues an instruction including an instruction to each of the plurality of monitoring devices by unicast communication to acquire the battery monitoring information of a type designated from the plurality of types, and an instruction to the plurality of monitoring devices by broadcast communication regarding the timing of acquiring the battery monitoring information; A program that executes the following.

24. A program to be executed by a control device that acquires battery monitoring information used for monitoring a state of a battery by wirelessly communicating with a plurality of monitoring devices and executes predetermined processing, A control device (50) a procedure for issuing instructions by an instruction unit (50b) including instructions to each of the plurality of monitoring devices to acquire the battery monitoring information by unicast communication and instructions to the plurality of monitoring devices regarding the timing of acquiring the battery monitoring information by broadcast communication during a communication cycle for communicating with the plurality of monitoring devices; an order setting unit (50c) executing a procedure for setting an order of the unicast communication to each of the plurality of monitoring devices and the broadcast communication to the plurality of monitoring devices during the communication cycle; the step of issuing an instruction by the instruction unit causes the instruction unit to issue instructions to the plurality of monitoring devices in the order set by the order setting unit; a program that causes the instruction unit to instruct the timing of acquiring the battery monitoring information to the plurality of monitoring devices via the unicast communication;

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