Monitoring device, control device, battery information communication system, battery information communication program, and battery information communication method

Abstract

To provide a monitoring device, a control device, a battery information communication system, a battery information communication program, and a battery information communication method capable of making communication speed in communicating battery information as high as possible while securing reliability of the communication.SOLUTION: A monitoring device 40 monitors a state of a battery transmits, as battery information, to a control device 50 via radio communication. A radio communication section 46 of the monitoring device 40 executes connection processing with a radio communication section 54 of the control device 50 to communicate the battery information. The radio communication section 46 of the monitoring device 40 sets communication speed in executing predetermined connection processing, which is at least a part of the connection processing with the radio communication section 54 of the control device 50 to be lower than communication speed in transmitting the battery information to the radio communication section 54 of the control device 50.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a monitoring device, a control device, a battery information communication system, a battery information communication program, and a battery information communication method. [Background technology]

[0002] For example, vehicles such as hybrid vehicles (HVs), plug-in hybrid vehicles (PHVs), and electric vehicles (EVs) are equipped with batteries, such as lithium-ion batteries, for running the vehicles. A battery monitoring system has been proposed in which a monitoring device monitors the state of the battery, etc. In the battery monitoring system, based on a command from a control device, the monitoring device acquires the state of the battery, such as the voltage of the battery cell, as battery information, and the control device acquires the battery information by wirelessly communicating with the monitoring device via a wireless communication unit. This allows the control device to comprehensively monitor the state of the battery.

[0003] As a document related to the present application, Patent Document 1 describes a technology for transmitting data by wireless communication. According to the technology described in Patent Document 1, the activation unit determines that the first stage has been received when the data pattern of the first stage of the wireless activation signal matches a predetermined data pattern, and determines that the second stage has been received when the data pattern of the second stage of the wireless activation signal matches the predetermined data pattern. In other words, an authentication technology using a data pattern during wireless communication is disclosed. In addition, the transmission speed of the first stage data pattern is set lower than the transmission speed of the two stages data pattern. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2014 / 132345 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, the battery monitoring system described in the Background section transmits a large amount of data related to the battery information from the monitoring device to the control device when communicating battery information. When transmitting a large amount of data, it is desirable to make the communication speed as fast as possible. However, in order to improve the reliability of communication, it is desirable to slow down the communication speed.

[0006] The object of the present disclosure is to provide a monitoring device, a control device, a battery information communication system, a battery information communication program, and a battery information communication method that enable the communication speed when communicating battery information to be as fast as possible while ensuring the reliability of communication. [Means for solving the problem]

[0007] The invention of claim 1 is directed to a monitoring device that monitors the state of a battery, converts it into battery information, and transmits it to a control device via wireless communication. The monitoring device includes a monitoring device-side communication unit that performs connection processing with the control device-side communication unit and communicates the battery information. The monitoring device-side communication unit sets a communication speed when performing a predetermined connection processing, which is at least a part of the connection processing, with the control device-side communication unit to be slower than the communication speed when transmitting the battery information to the control device-side communication unit.

[0008] It is desirable to improve the communication speed when the monitoring device communication unit transmits battery information. Conversely, it is desirable to avoid deterioration of communication reliability when the monitoring device communication unit executes a predetermined connection process, which is at least a part of the connection process, with the control device communication unit. According to the invention described in claim 1, since the communication speed during the predetermined connection process is slower than the communication speed when communicating battery information, it is possible to reduce the error rate during the predetermined connection process and ensure the reliability of communication during the predetermined connection process. In addition, since the communication speed when communicating battery information is faster than the communication speed during the predetermined connection process, it is possible to increase the amount of data transmission of battery information. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing a battery monitoring system according to a first embodiment; [Diagram 2] FIG. 2 is a perspective view showing a schematic structure of a battery pack; [Diagram 3] FIG. 3 is a side view showing a schematic structure of a battery pack; [Figure 4] FIG. 2 is a plan view showing a schematic structure of a battery pack; [Diagram 5] Battery monitoring system electrical configuration diagram [Figure 6] Sequence diagram 1 showing the outline of the communication flow [Figure 7] Sequence diagram 2 showing the outline of the communication flow [Figure 8] A time chart showing the flow of communication [Figure 9] FIG. 11 is a sequence diagram showing a flow of communication in the second embodiment. [Figure 10] FIG. 2 is a diagram showing a schematic diagram of the time progression of a connection process and a battery information communication process; [Figure 11] A time chart showing the flow of communication [Figure 12] FIG. 11 is a sequence diagram illustrating a flow of communication in the third embodiment. [Figure 13] Packet contents diagram 1 [Figure 14] Packet contents diagram 2 [Figure 15] FIG. 13 is a sequence diagram illustrating a flow of communication in a first modified example of the third embodiment. [Figure 16] A time chart showing the flow of communication [Figure 17] FIG. 13 is a sequence diagram illustrating a flow of communication in a second modified example of the third embodiment. [Figure 18] FIG. 13 is a sequence diagram illustrating a method for changing a communication speed according to a third modification of the third embodiment. [Figure 19] 13 is a timing chart showing an outline of a communication flow in a third modification of the third embodiment. [Figure 20] FIG. 13 is a sequence diagram showing a method for changing a communication speed according to a fourth modification of the third embodiment; [Figure 21] FIG. 13 is a sequence diagram showing an outline of a method for changing a communication speed in the fourth embodiment. [Figure 22] FIG. 1 is a sequence diagram showing a flow of communication in the fifth embodiment. [Figure 23] Sequence diagram 2 showing the outline of the communication flow [Figure 24] FIG. 1 is an explanatory diagram of a method for equalizing cell voltages according to the sixth embodiment. [Diagram 25] Diagram of cell voltage equalization method 2 [Figure 26] FIG. 13 is a perspective view showing a schematic structure of a battery pack according to a seventh embodiment; [Figure 27] FIG. 13 is a perspective view showing a schematic structure of a battery pack according to an eighth embodiment; [Figure 28] FIG. 13 is a perspective view showing a schematic structure of a battery pack according to a ninth embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, several embodiments of a monitoring device, a control device, and a battery monitoring system 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.

[0011] (First embodiment) The first embodiment will be described with reference to Fig. 1 to Fig. 8. As shown in Fig. 1, a battery monitoring system 1 is mainly configured with a battery pack system 2 and is built into a vehicle 10. The vehicle 10 is a hybrid vehicle (HV), a plug-in hybrid vehicle (PHV), an electric vehicle (EV), or the like, and runs using a battery assembly 12 (see Fig. 2) of an installed battery pack 11 as at least a part of its drive source.

[0012] 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 disposed in an engine compartment of the vehicle body 13, but may also be disposed under a seat of a passenger, for example, a driver, around the frame of the vehicle body 13, in a trunk, or the like.

[0013] As shown in Fig. 2, the battery pack 11 includes a battery module 20 in which battery cells 22 are grouped into a plurality of groups. The battery pack 11 includes a plurality of groups of battery modules 20. A large number of battery cells 22 are housed in the battery module 20 to form an assembled battery 12. The assembled battery 12 is used as a drive source for the vehicle 10 by storing power for driving a motor 15. 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.

[0014] <Structure of battery pack 11> An example of the structure of the battery pack 11 will be described below with reference to FIGS. In Fig. 2, the inner wall of the housing 30 is indicated by a two-dot chain line. 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 in a mutually intersecting (e.g., perpendicular) relationship. The housing 30 has a first wall surface 30a along the X direction and a second wall surface 30b along the Y direction. The housing 30 is formed into a flat, low-profile rectangular box shape.

[0015] 2, the housing 30 of the battery pack 11 houses the assembled battery 12, a plurality of monitoring devices 40, and a control device 50 in a planar manner along the X and Y directions. The monitoring device 40 is equipped with a battery monitoring unit 44 (see FIG. 5) that monitors the state of the assembled battery 12 of the battery pack 11, and is called a satellite battery module (SBM).

[0016] The Z-direction lower surface of the housing 30 is the mounting surface to 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 in Figures 2 to 4 are merely examples. The mounting direction to the vehicle body 13 is merely an example, and the battery pack 11 may be disposed in any manner relative to the vehicle 10.

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

[0018] Each battery module 20 has a plurality of battery cells 22 each configured in a rectangular box shape. The battery module 20 is configured to have a plurality of battery cells 22 grouped together. In each battery module 20, the plurality of battery cells 22 are arranged side by side in the Y direction. The plurality of battery cells 22 are each housed in a battery case (not shown), thereby fixing the relative positions of the plurality of battery cells 22. The battery case is made of metal or resin. When the battery case is made of metal and configured in a rectangular box shape, an electrically insulating member is generally 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 battery module 20 has a plurality of battery cells 22 connected in series. The battery module 20 of the present 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.

[0020] The battery cell 22 is a secondary battery that generates an electromotive force by 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 that use a liquid electrolyte, but also so-called all-solid-state batteries that use a solid electrolyte.

[0021] 2 to 4, the battery cells 22 are stacked such that the side surfaces of the battery cases are in contact with each other in the Y direction. Each battery cell 22 is located at both ends in the X direction and has a positive terminal 23 and a negative terminal 24 that protrude in the Z direction, more specifically, in the Z+ direction indicating upward. As shown in Fig. 3, the Z direction positions of the protruding end faces of the positive terminal 23 and the negative terminal 24 are arranged at the same height in each battery cell 22. As shown in Fig. 4, the battery cells 22 are stacked such that the positive terminals 23 and the negative terminals 24 are arranged alternately in the Y direction.

[0022] 4, a pair of linear busbar units 25 are arranged on both ends in the X direction on the top surface of each battery module 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 the negative electrode terminals 24 of the multiple battery cases.

[0023] 3 and 4, each busbar unit 25 has a plurality of busbars 26 that electrically connect the positive electrode terminals 23 and the negative electrode terminals 24 that are alternately arranged in the Y direction, and a busbar cover 27 that covers the plurality of busbars 26. The busbars 26 are plate materials made of a metal with good conductivity such as copper or aluminum. The busbars 26 electrically connect the positive electrode terminals 23 and the negative electrode terminals 24 of the battery cells 22 that are adjacent to each other in the Y direction. As a result, in each battery module 20, the plurality of battery cells 22 are connected in series.

[0024] Each battery module 20 is configured by arranging a plurality of battery cells 22 in parallel in the Y direction. As shown in Figs. 3 and 4, the bus bar cover 27 is arranged along the Y direction so as to cover the positive electrode terminals 23 and the negative electrode terminals 24 of the plurality of battery cells 22 of each battery module 20. As shown in Fig. 3, the bus bar cover 27 is arranged at both ends of the battery cells 22 in the X direction and is arranged to protrude upward from the upper surface of the battery cells 22. As shown in Fig. 3, the space S1a is provided so as to be surrounded by the top surface 11g of the battery pack 11, i.e., the upper inner surface 30c of the housing 30, the inner surface of the bus bar cover 27, and the upper surface of the battery cells 22. The space S1a is provided so as to be located on the lower side of the upper inner surface 30c of the housing 30 and to communicate with each other in the X direction. This space S1a is provided as a propagation path for electromagnetic waves.

[0025] Here, the electrical connection state of a certain battery module 20 will be described with reference to FIG. 4. In a certain battery module 20, one end in the X direction 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 the first battery cell 22. The second battery cell 22 is disposed such that the X direction positions of the positive electrode and the negative electrode 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 are reversed from 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 arranged 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 module 20 are electrically connected in series.

[0027] In each battery module 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 wire 20w shown in FIG. 2 is connected to at least one of the positive electrode terminal 23 of the battery cell 22 with the highest potential and the negative electrode terminal 24 of the battery cell 22 with the lowest potential.

[0028] 2 to 4, the positive terminal 23 of the battery cell 22 with the highest potential in one of two battery modules 20 adjacent to each other in the X direction is connected via a wire 20w to the negative terminal 24 of the battery cell 22 with the lowest potential in the other battery module 20. In this way, the multiple battery modules 20 are electrically connected in series.

[0029] One of the two battery modules 20 located at the ends of the multiple battery modules 20 lined up in the X direction is the highest potential side, and the other is the lowest potential side. In the battery module 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.

[0030] In the battery module 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 be at least partially opposed to each other in the X direction.

[0031] Note that two battery modules 20 adjacent to each other in the X direction do not necessarily have to be electrically connected via the wire 20w, and any two of the plurality of battery modules 20 may be electrically connected via the wire 20w.

[0032] The busbar cover 27 shown in Figures 3 and 4 is made of an electrically insulating material such as resin. The busbar cover 27 is provided linearly from one end of the battery module 20 to the other end along the Y direction so as to cover the multiple busbars 26. The busbar cover 27 may have a partition wall. Providing the partition wall can improve the insulation between two busbars 26 adjacent to each other in the Y direction.

[0033] 2, one monitoring device 40 is provided for each pair of adjacent battery modules 20 in the X direction. Here, a monitoring device 40 is provided for each pair of adjacent battery modules 20, but as will be described in an embodiment below, a monitoring device 40 may be provided for each single battery module 20, or for three or more battery modules 20.

[0034] The monitoring device 40 is provided on the inner side of the first wall surface 30a of the housing 30 along the extension direction (X direction) of the first wall surface 30a, and is arranged straddling two battery modules 20 along the X direction. The multiple monitoring devices 40 are located at one end of the battery modules 20 in the Y direction and arranged side by side in the X direction. The monitoring devices 40 are provided on the inner side of the first wall surface 30a along the X direction of the housing 30. The multiple monitoring devices 40 are arranged at the same position in the Y direction.

[0035] 2 shows a structure in which the multiple monitoring devices 40 are arranged side by side at one end in the Y direction of the battery module 20, but the present invention is not limited to this structure. For example, the multiple monitoring devices 40 may be arranged alternately at one end / the other end in the Y direction for every two battery modules 20, or may not be arranged alternately in a regular manner.

[0036] The monitoring device 40 is fitted, for example, into a recess provided in the battery module 20 and fixed with a screw. The method of fixing the monitoring device 40 is not limited to this method. For example, the monitoring device 40 may be fixed to the battery module 20 by thermal crimping, which involves joining and crimping by applying heat and pressure. In addition, the monitoring device 40 may be fixed to the battery module 20 by a snap-fit ​​structure that utilizes the elastic deformation of a metal or resin material.

[0037] When the monitoring device 40 is attached to the battery module 20, the external dimensions of the monitoring device 40 are arranged so that the relationship in the X direction>Z direction>Y direction is satisfied. A space S1 is provided around the monitoring device 40. The space S1 is a space partially surrounded by the first wall surface 30a and the second wall surface 30b of the housing 30 and the wall surface 20a of the battery module 20. The monitoring device 40 is arranged so that the Y direction thickness is the thinnest among the XYZ directions. Even if the battery module 20 is configured by arranging a large number of battery cells 22 in the Y direction and is configured to be wide in the Y direction, the monitoring device 40 can be arranged in the space S1 where the Y direction is extremely small. This allows the space S1 on the inner side of the first wall surface 30a of the housing 30 to be effectively utilized.

[0038] The monitoring device 40 is preferably disposed on the wall surface 20a of the battery module 20, closer to the upper side in the Z direction than to the lower side in the Z direction from the center of the height of the battery cells 22. Note that as long as most of the monitoring device 40 is disposed above the center of the height of the battery cells 22, another part may be disposed below the center of the height of the battery cells 22. In other words, the monitoring device 40 is preferably disposed such that the area above the center of the height of the battery cells 22 is larger than the area below. In this case, the monitoring device 40 can be easily disposed from the upper side of the battery module 20, for example, and the assembling of the monitoring device 40 to the battery module 20 can be facilitated.

[0039] 2, the control device 50 is attached to an outer end surface in the X direction of a battery module 20 that is located at an end in the X direction among all the battery modules 20. As shown in Fig. 5, the monitoring device 40 includes an antenna 49, and the control device 50 includes an antenna 57, and the control device 50 and the multiple monitoring devices 40 are wirelessly connected to each other.

[0040] If a structure in which the control device 50 and the monitoring device 40 are connected by wire is adopted, it becomes necessary to connect a harness between the monitoring device 40 and the control device 50. For example, if an operator were to extend a harness into the space S1 on the inner side of the first wall surface 30a of the housing 30 to connect the monitoring device 40 and the control device 50, the assembly would be difficult and a lot of labor would be required. In this regard, since the monitoring device 40 and the control device 50 are configured to be connected wirelessly, the monitoring device 40 can be placed in even the smallest space S1 without deteriorating the assembly.

[0041] The fixing member for fixing the monitoring device 40 to the battery module 20 may be made of, for example, a non-magnetic material, which can improve wireless communication performance. The components provided in the battery module 20 may be made of a non-magnetic material, particularly when the components do not require magnetic properties due to their characteristics.

[0042] The monitoring device 40 is fixed to the end surface of the battery module 20 on the Y direction side. As shown in Fig. 2 and Fig. 3, a detection line L is connected to the monitoring device 40. The detection line L is configured for each battery module 20. The detection line L extends upward from the upper part of the monitoring device 40, bends at the end of the battery module 20, and extends across the upper surfaces of the multiple battery cells 22 in the Y direction. The detection line L indicates a harness for detecting the voltage between the positive terminal 23 and the negative terminal 24 of each battery cell 22.

[0043] The detection wires L are configured to extend in the Y direction along the upper surfaces of the multiple battery cells 22 that constitute one battery module 20. The detection wires L are configured to span between the bus bar covers 27 that are configured at both ends in the X direction of each battery cell 22. The detection wires L are electrically connected to the positive electrode terminals 23 and negative electrode terminals 24 of each battery cell 22 by having core wires (not shown) extending from a central position extending in the Y direction to both sides in the X direction.

[0044] <Structural description of case 30> The housing 30 has, for example, a property of reflecting electromagnetic waves in order to counter EMC. EMC is an abbreviation of Electromagnetic Compatibility. The housing 30 is configured to include a resin material and a metal having magnetic properties for reflecting electromagnetic waves, that is, a magnetic material. The housing 30 may be configured to include a resin material, and the magnetic material may be configured to cover the resin material or may be configured to be embedded inside the resin material. The housing 30 may be formed of a resin material, but it is preferable that the housing 30 is covered by the chassis of the vehicle 10 in order to counter EMC. The housing 30 may be configured to include carbon fiber. The housing 30 may be configured to include a material having a property of absorbing electromagnetic waves instead of a property of reflecting electromagnetic waves.

[0045] A wall surface 20a (see Figs. 2 and 4) located at one end in the Y direction of the multiple battery modules 20 is configured across the X direction. The wall surface 20a may be covered with a reflective material (e.g., a metal or a magnetic material having magnetic properties) for reflecting electromagnetic waves. A space S1 located on the inner side of the first wall surface 30a of the housing 30 has vertical and horizontal dimensions in the YZ direction of, for example, several mm to several cm to several tens of cm.

[0046] As described above, the space S1 is partially surrounded by the wall surface 20a of the battery module 20, and the first wall surface 30a, the lower inner surface 30d, the upper inner surface 30c, and the second wall surface 30b of the housing 30. The space S1 is partially closed by a metal serving as a reflective member, and is open only on one side of the space S1b in the X direction where the control device 50 is disposed (the third wall surface 30e side in the left direction in FIG. 4).

[0047] The monitoring devices 40 are arranged periodically (e.g., at equal intervals) in the space S1 in the X direction. If the space S1 is covered with metal, the space S1 forms a waveguide space similar to a so-called rectangular waveguide. As shown in Fig. 4, the housing 30 forms a space closed by a first wall surface 30a, a second wall surface 30b, a third wall surface 30e, and a fourth wall surface 30f in a plan view.

[0048] The first wall surface 30a faces the fourth wall surface 30f, and the second wall surface 30b faces the third wall surface 30e. In this case, the propagation space of the electromagnetic wave when the control device 50 and the monitoring device 40 wirelessly communicate is L-shaped in a plan view. The wireless electromagnetic wave emitted by the control device 50 is reflected by the first wall surface 30a and propagates into the space S1, and is also reflected by the third wall surface 30e and propagates into the space S1 to reach the monitoring device 40.

[0049] Wireless electromagnetic waves emitted by the monitoring device 40 propagate through the space S1, are reflected by the first wall surface 30a, and reach the control device 50, and also propagate through the space S1, are reflected by the third wall surface 30e, and reach the control device 50. As a result, when the control device 50 and the monitoring device 40 communicate wirelessly, the radio waves propagate along an L-shaped propagation path that includes the space S1.

[0050] In this embodiment, the propagation path of electromagnetic waves when the control device 50 and the monitoring device 40 wirelessly communicate with each other also includes the space S1a shown in Fig. 3. This space S1a is sandwiched between the bus bar covers 27 arranged on both ends of the battery cell 22 in the X direction, and is provided so as to be surrounded by the top surface 11g of the battery pack 11, i.e., the upper inner surface 30c of the housing 30, and the upper surfaces of the battery cells 22. The space S1a is provided so as to have a gap below the upper inner surface 30c of the housing 30.

[0051] The space S1a communicates in the X direction along the lower side of the upper inner surface 30c of the housing 30. The space S1a communicates in the X direction to the space S1b in which the control device 50 is disposed. In this way, the spaces S1a and S1b can be used as propagation paths for wireless electromagnetic waves between the control device 50 and the monitoring device 40, so that many communication paths can be secured in addition to the above-mentioned L-shaped propagation path.

[0052] 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, and for passing electricity through power lines and signal lines. In the case of a configuration having holes, a cover (not shown) that covers the holes may be provided. The cover is formed of, for example, a connector, an electromagnetic shielding member, a sealing material, etc., and closes a part or all of the holes between the storage space for the battery pack 11 and the space outside it.

[0053] The covering portion is configured to include, for example, a metal material having magnetic properties. The covering portion may include 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 configured to include carbon fiber.

[0054] The holes in the housing 30 may be covered by elements accommodated in the accommodation space of the housing 30 without providing a separate cover. Furthermore, the power lines and signal lines may be arranged across the accommodation space and the external space while being held by an electrically insulating member that forms part of the wall of the housing 30.

[0055] <Modification of the arrangement of the plurality of monitoring devices 40 and the control device 50> 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 modules 20 inside the housing 30, respectively, while the control device 50 may be mounted on the outer surface of the housing 30.

[0056] 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 device 40 and the control device 50 face each other. In this case, the radio wave propagation environment between the monitoring device 40 and the control device 50 is worse than that of the mounting structure shown in Fig. 2, but it is sufficient if the monitoring device 40 and the control device 50 can communicate with each other. For example, the wall surface of the housing 30 on which the control device 50 is provided may be made of a resin through which radio waves can pass. Also, an opening may be formed in the wall surface of the housing 30, and the control device 50 may be disposed in such a manner as to close the opening.

[0057] Antenna 49 of monitoring device 40 may be arranged so as not to overlap with busbar unit 25 in the XY directions, that is, so as to protrude in the Z direction beyond busbar unit 25. Antenna 57 of control device 50 may be provided so as to protrude in the Z direction beyond busbar unit 25. Antenna 57 connected to control device 50 may be arranged at a height in the Z direction approximately equal to that of antenna 49 of monitoring device 40, for example. Note that the positional relationship between antennas 49, 57 is not limited to this relationship.

[0058] <Modifications of the arrangement of the battery module 20> In this embodiment, a plurality of battery modules 20, each containing a plurality of battery cells 22, are prepared and directly housed in a housing 30, but the present invention may be applied to a so-called battery module-less structure. For example, as is called cell-to-pack, the battery modules of the battery cells 22 may be omitted and the plurality of battery cells 22 may be directly housed in the battery pack 11. Cell-to-pack is the Japanese hiragana abbreviation of Cell to Pack (CTP).

[0059] As it is called a battery module to platform, the battery module 20 may be directly delivered to the frame or platform of the vehicle 10. The battery module to platform indicates the content of Module to Platform (MTP) in kana notation. As it is also called cell to chassis, the battery cells 22 may be directly packed onto the underframe of the vehicle 10 and mounted as part of the vehicle body structure inside the chassis. The cell to chassis indicates the content of Cell to Chassis (CTC) in kana notation.

[0060] <Configuration description of PCU14, motor 15, and upper ECU16> The upper ECU16 and the control device 50 may be configured by integrating some or all of them, or may be provided separately. The PCU14 shown in FIG. 1 performs bidirectional power conversion between the battery pack 11 and the motor 15 according to the control signal from the upper ECU16. The PCU14 includes, for example, an inverter that drives the motor 15 and a converter that boosts the DC voltage supplied to the inverter to be equal to or higher than the output voltage of the battery pack 11.

[0061] The motor 15 is an AC rotating electric machine, for example, a three-phase AC synchronous motor with permanent magnets embedded in the rotor. The motor 15 is driven by the PCU14 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 PCU12 and stored in the battery cells 12 of the battery pack 11.

[0062] The host ECU 16 is configured to include a CPU, memories such as ROM, RAM, and non-volatile semiconductor storage devices, input / output ports for inputting and outputting various signals, etc. The memory stores processing programs executed by the host ECU 16, and the CPU executes the programs stored in the memory. The memory is used as a non-transient substantial recording medium. The control device 50 receives information on the cell voltages of each battery cell 22 of the assembled battery 12 from the monitoring device 40 of the battery pack 11, measures the SOC (State Of Charge), and controls the PCU 12 to control the drive of the motor 15 and the charging and discharging of the battery pack 11.

[0063] A current sensor 17 (see FIG. 5) is connected in series to the battery pack 12, thereby making it possible to measure the current flowing through the entire battery pack 12. As shown in FIG. 5, the current sensor 17 is connected to a control device 50. The host ECU 16 can obtain information on the current flowing through the battery pack 12 or the battery cells 22, measured by the current sensor 17, via the monitoring device 40 and the control device 50.

[0064] Here, the current sensor 17 is connected to the control device 50, but the current sensor 17 may be connected to the host ECU 16. Since the control device 50 and the host ECU 16 can be connected to each other for communication, whichever configuration obtains the current information of the current sensor 17, the information on the current flowing through the battery pack 12 can be shared.

[0065] The electrical block configurations of the monitoring device 40 and the control device 50 will be described below. <Example of Electrical Block Configuration of Monitoring Device 40> 5, the monitoring device 40 includes power supply circuits 41 to 43, a battery monitoring unit 44, a microcomputer 45, a wireless communication unit 46, a selection circuit 47, a matching circuit 48, and an antenna 49. The power supply circuit 41 of the monitoring device 40 generates an operating voltage using a voltage supplied from the battery module 20, and supplies the generated voltage to the power supply circuits 42 and 43 as well as to the battery monitoring unit 44.

[0066] The power supply circuit 41 includes a rectifier 41a and a start-up circuit 41b. The rectifier 41a receives power from the battery module 20, which serves as a power supply unit, rectifies and smooths the power to generate DC power. The start-up circuit 41b receives the DC power rectified and smoothed by the rectifier 41a and generates a start-up signal for starting up a part or the entirety of the monitoring device 40.

[0067] The start-up circuit 41b desirably receives power only from one or more battery modules 20 that are connected by wire at the time of start-up. In other words, it is desirable to receive power via a wire, and not wirelessly. Starting up by receiving power via a wire makes it easier to ensure security.

[0068] Furthermore, if the battery monitoring unit 44 were activated externally via wireless communication, it may cause diffuse reflection inside the housing 30 and may delay the activation of the battery monitoring unit 44. As a result, it may become impossible to manage the monitoring schedule for the battery pack 12 by the battery monitoring unit 44. By activating the power supply via a wired connection, it is possible to eliminate the need for a wireless sequence for activating the power supply, and it is possible to easily manage the battery monitoring schedule.

[0069] The start-up circuit 41b starts up some or all of the battery monitoring unit 44, the microcomputer 45, and the wireless communication unit 46. As shown in S30 of Fig. 7, the monitoring IC constituting the battery monitoring unit 44 should be started when or before the wireless communication unit 54 of the control device 50 and the wireless communication unit 46 of the monitoring device are synchronized. In this embodiment, the start-up circuit 41b is provided in the power supply circuit 41, but as will be described in a later embodiment, it may be provided in the wireless communication unit 46.

[0070] The power supply circuit 42 generates an operating voltage from the output of the power supply circuit 41 and supplies the generated voltage to the microcomputer 45. The power supply circuit 43 generates an operating voltage from the output of the power supply circuit 41 and supplies the generated voltage to the wireless communication unit 46.

[0071] The selection circuit 47 of the monitoring device 40 receives as battery information a cell temperature signal from a temperature sensor (not shown) that measures the temperature of the battery cells 22 and a cell discrimination signal that discriminates the type of battery cell 22, and selects the battery information and inputs it to the battery monitoring unit 44. The battery monitoring unit 44 of the monitoring device 40 senses the cell voltage, cell temperature, cell discrimination battery information, etc. of the battery cells 22.

[0072] The battery monitoring unit 44 includes a monitoring unit 44a that acquires battery information of the battery cells 22 of the battery pack 12, a conversion unit 44b that converts the analog value of the battery information input through the selection circuit 47 into a digital value and outputs it, and a storage unit 44c that stores the digital value of the battery information. The monitoring unit 44a is composed of one or more monitoring ICs. When the battery monitoring unit 44 is configured with multiple monitoring ICs, the battery cells 22 that are responsible for acquiring battery information are determined in advance. The storage unit 44c is composed of a register or the like. The battery monitoring unit 44 sequentially stores the battery information of the battery cells 22 in the storage unit 44c, but erases it as necessary to ensure memory capacity.

[0073] The battery monitoring unit 44 stores the battery information, such as cell voltage information of the battery cells 22, battery temperature information, and identification information of the battery cells 22, as battery monitoring information in a memory unit 46a of the wireless communication unit 46 via the microcomputer 45. The battery monitoring unit 44 executes a fault diagnosis of the circuit portion of the monitoring device 40, monitors the fault diagnosis information, and stores the fault diagnosis information in the memory unit 46a of the wireless communication unit 46 via the microcomputer 45 as battery information.

[0074] The microcomputer 45 of the monitoring device 40 receives the battery information input from the battery monitoring unit 44 and transmits it to the wireless communication unit 46. The microcomputer 45 represents a control circuit having a function of controlling the schedule for the battery monitoring unit 44 to acquire the battery information and the like.

[0075] The wireless communication unit 46 includes a storage unit 46a, and wirelessly transmits information stored in the storage unit 46a to and from the wireless communication unit 54 of the control device 50. When the wireless communication unit 46 of the monitoring device 40 receives battery information from the microcomputer 45, it stores the battery information in the storage unit 46a and transmits the battery information to the master control device 50. The wireless communication unit 46 transmits information to the wireless communication unit 54 of the control device 50, and stores the battery information from the wireless communication unit 54 of the control device 50 in the storage unit 46a. The wireless communication unit 46 represents a communication device that controls the communication data size, communication format, schedule, error detection, and the like between the monitoring device 40 and the control device 50.

[0076] A predetermined frequency range is allocated as a band in which wireless communication is possible between the wireless communication units 54 and 46. A plurality of usable frequency bands obtained by frequency-dividing this predetermined frequency range are divided into channels. The plurality of channels are divided into a first channel group of non-battery information communication frequency bands and a second channel group of battery information communication frequency bands. The first channel group and the second channel group each consist of one or a plurality of channels. Although both the first channel group and the second channel group are capable of communicating both battery information and non-battery information, the second channel group is mainly used for communicating battery information, and the first channel group is mainly used for communicating information other than battery information.

[0077] The wireless communication unit 54 of the control device 50 and the wireless communication unit 46 of the monitoring device 40 digitally modulate a single carrier wave using a predetermined digital modulation method within the frequency band used for each channel of the first channel group or the second channel group to communicate each piece of information. The predetermined digital modulation method is, for example, a frequency modulation method, but other various modulation methods such as amplitude modulation and phase modulation may also be applied.

[0078] The wireless communication unit 54 of the control device 50 and the wireless communication unit 46 of the monitoring device 40 can change the communication speed of each piece of information between the wireless communication units 54 and 46 in two or more stages by changing the modulation speed of a predetermined digital modulation method. In particular, in this embodiment, the communication speed of various pieces of information such as non-battery information and battery information transmitted from the wireless communication unit 46 of the monitoring device 40 to the wireless communication unit 54 of the control device 50 can be changed in stages. The communication speed indicates the amount of data transferred per unit time when it is assumed that the error rate is constant.

[0079] In this embodiment, a form will be described in which communication is performed at a relatively high communication speed in the second channel group of the pre-assigned battery information communication frequency band, and communication is performed at a relatively low communication speed in the first channel group of the non-battery information communication frequency band. That is, a form will be described in which communication is performed at two communication speeds. In the description of this embodiment and other embodiments, a form in which the modulation speed is changed in two steps and the communication speed is changed in two steps will be described, but the present invention may be applied to a form in which the modulation speed is changed in three or more steps and the communication speed is changed in three or more steps.

[0080] The memory unit 54a of the wireless communication unit 54 and the memory unit 46a of the wireless communication unit 46 of the monitoring device 40 are stored in advance such that when performing high-speed communication in the second group of channels in the battery information communication frequency band, digital modulation / demodulation is performed at a relatively high predetermined modulation speed. Also, when performing low-speed communication in the first group of channels in the non-battery information frequency band, digital modulation / demodulation is performed at a relatively low predetermined modulation speed.

[0081] Therefore, the wireless communication unit 54 of the control device 50 communicates at a low speed when communicating with the wireless communication unit 46 of the monitoring device 40 on a channel in the first channel group, and communicates at a high speed when communicating on a channel in the second channel group.

[0082] The matching circuit 48 and antenna 49 of the monitoring device 40 represent a physical interface for converting the output signal of the wireless communication unit 46 into radio waves and radiating them into space, and for receiving the radio waves propagating through space and inputting them into the wireless communication unit 46.

[0083] The microcomputer 45 described above does not have to be implemented, and in this case, it is preferable to configure the wireless communication unit 46 and the battery monitoring unit 44 to directly communicate with each other. The wireless communication unit 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 battery monitoring unit 44.

[0084] <Specific configuration example of the control device 50> The control device 50 includes power supply circuits 51 and 52, a main microcomputer 53, a wireless communication unit 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 a voltage supplied from an auxiliary battery 60, and supplies the operating voltage 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 the operating voltage to the wireless communication unit 54.

[0085] The matching circuit 56 and antenna 57 of the control device 50 represent a physical interface for converting the signal output by the wireless communication unit 54 into radio waves and radiating them into space, receiving the radio waves propagating through space, and inputting them into the wireless communication unit 54.

[0086] The wireless communication unit 54 of the control device 50 receives battery monitoring information or fault diagnosis information as battery information from the wireless communication unit 46 of the monitoring device 40, and transmits the information to the main microcomputer 53 of the control device 50. The wireless communication unit 54 on the control device 50 side also receives data transmitted from the main microcomputer 53, and transmits it to the wireless communication unit 46 of the monitoring device 40. The wireless communication unit 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.

[0087] 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 communication unit 46, and transmits the calculated information to the host ECU 16. The main microcomputer 53 performs switching control according to the on / off state of the ignition switch. The main microcomputer 53 functions as an equalization control unit 53a for equalizing the cell voltages of the battery cells 22.

[0088] The main microcomputer 53 transmits information such as control signals to the monitoring device 40 by wireless communication through the wireless communication units 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 communication unit 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 communication unit 54.

[0089] In this embodiment, the control device 50 includes a sub-microcomputer 55, which monitors data exchanged between the wireless communication unit 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.

[0090] In addition, as described 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 battery monitoring unit 44 instead of the microcontroller 45.

[0091] In this embodiment, 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 battery information such as the voltage and temperature of the battery cells 22 transmitted from the wireless communication unit 46, and transmits the calculated information to the host ECU 16. However, the calculation of the battery information is not limited to this example.

[0092] For example, the microcomputer 45 of the monitoring device 40 may calculate the SOC and diagnostic information, which are indicators of the state of the battery cell 22, using battery information such as the voltage and temperature of the battery cell 22 acquired by the battery monitoring unit 44, and transmit the calculation result to the wireless communication unit 54 of the control device 50. In addition, the microcomputer 45 of the monitoring device 40 may diagnose an abnormality in the battery cell 22 or the battery monitoring unit 44 using the calculation result, and may transmit the abnormality diagnosis result to the wireless communication unit 54 of the control device 50.

[0093] Furthermore, the battery information such as the voltage and temperature of the battery cell 22 acquired by the battery monitoring unit 44 of the monitoring device 40 may be calculated by the wireless communication unit 46 of the monitoring device 40. Moreover, the battery information such as the voltage and temperature of the battery cell 22 acquired by the battery monitoring unit 44 of the monitoring device 40 may be calculated by the wireless communication unit 54 of the control device 50. In addition, the microcomputer 45 of the monitoring device 40 may use the calculation result to perform an abnormality diagnosis of the battery cell 22, and may transmit the result of the abnormality diagnosis to the wireless communication unit 54 of the control device 50 as battery information.

[0094] <Wireless communication> Next, wireless communication processing between the monitoring device 40 and the control device 50 will be described with reference to Fig. 6 and Fig. 7. In the battery monitoring system 1 of this embodiment, multiple monitoring devices 40 are connected in a star network with the control device 50 at the center, enabling packet communication. The control device 50 establishes communication individually with each of the multiple monitoring devices 40 and wirelessly communicates information.

[0095] <When vehicle 10 is stopped> When the vehicle 10 is stopped, it is less important to monitor the battery pack 12 than when the vehicle 10 is in an activated state. This is because it does not affect the safety of driving. It is preferable to change the quality of wireless communication depending on the activated / activated state of the vehicle 10, and it is preferable for the monitoring device 40 to communicate at a slower speed when the vehicle 10 is in a stopped state than when the vehicle 10 is in an activated state. It is preferable to perform communication with a higher success rate by slowing down the communication speed. This makes it possible to reduce the number of retransmissions due to communication failures. As a result, it is possible to suppress discomfort to the user caused by delays in starting up the vehicle 10.

[0096] <About starting vehicle 10> 8, 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 is started, a connection process S100 (connection processes T1 to T3 described below) is executed between the control device 50 and all of the monitoring devices 40. If the connection process S100 is successful, the control device 50 executes a periodic communication process S200 (periodic communication process T4 described below) with the monitoring devices 40 with which a connection has been established.

[0097] In the periodic communication process S200, the wireless communication unit 54 of the control device 50 configures a command in one or more packets to instruct the monitoring device 40 for which the connection process S100 has been completed to obtain battery information, and transmits the packet. At this time, the wireless communication unit 54 of the control device 50 transmits the command to the wireless communication units 46 of the multiple monitoring devices 40 by time-division unicast communication. In response to this command, the multiple monitoring devices 40 return their battery information to the wireless communication unit 54 of the control device 50.

[0098] <Details about the connection process S100> The wireless communication unit 46 of the monitoring device 40 periodically transmits a preview detection request S21 and a continuous detection request S22 in the non-battery information communication frequency band while processing other scheduled tasks until it receives a connection request S13 from the wireless communication unit 54 of the control device 50.

[0099] The advance notice detection request S21 in the connection process T1 in FIG. 7 and FIG. 8 indicates a notification command for notifying the outside of the existence of the wireless communication unit 46 of the monitoring device 40 itself.

[0100] The advance notice detection request S21 includes transmission reservation timing information indicating the transmission timing of the continuous detection request S22 to be transmitted after the advance notice detection request S21 is transmitted. The transmission reservation timing information is data indicating that the transmission will occur after a predetermined time. Therefore, the advance notice detection request S21 is a advance notice command for advising the transmission timing of the continuous detection request S22, which will be described later. The wireless communication unit 46 of the monitoring device 40 continues to periodically transmit the advance notice detection request S21 and the continuous detection request S22 even when the ignition switch is off.

[0101] The advance notice detection request S21 continues to be periodically transmitted by asynchronous processing so that the wireless communication unit 54 of the control device 50 present in the vicinity detects its own presence. The wireless communication unit 46 of the monitoring device 40 continues to transmit the advance notice detection request S21 without identifying the communication partner, which makes it difficult to establish a connection. For this reason, it is preferable to transmit at least a part of the predetermined connection processing in the connection processing S100, for example, the communication speed when transmitting the advance notice detection request S21 at the beginning of the connection processing S100, at a communication speed slower than the communication speed in the periodic communication processing S200 for communicating battery information described later. It is preferable that the wireless communication unit 46 of the monitoring device 40 identifies the communication partner, establishes a connection, synchronizes, and then communicates at a high speed. This makes it possible to realize communication suitable for the characteristics of communication of battery information with a large amount of data, for example, the periodic communication processing S200, and the connection processing S100 with a small amount of data.

[0102] 7 and 8, the wireless communication unit 46 of the monitoring device 40 transmits a continuous detection request S22 at a timing indicated by the transmission reservation timing information announced in the advance detection request S21. The wireless communication unit 46 of the monitoring device 40 transmits the continuous detection request S22 at a timing when the transmission reservation timing time has elapsed, while processing other scheduled tasks and waiting for a connection request S13 from the monitoring device 40.

[0103] At this time, it is desirable for the wireless communication unit 46 of the monitoring device 40 to transmit the continuous detection request S22 at high speed on one or more channels of the second channel group of the battery information communication frequency band described above. The wireless communication unit 46 of the monitoring device 40 may transmit the continuous detection request S22 on one or more channels of the first channel group of the non-battery information communication frequency band. It is preferable for the wireless communication unit 46 of the monitoring device 40 to communicate at least the advance detection request S21 at a low speed. See connection process T2 of the continuous detection request S22 in FIG. 8.

[0104] Even if the wireless communication unit 46 of the monitoring device 40 does not receive the connection request S13 during a predetermined time from the transmission timing of the advance detection request S21 or during a predetermined time from the transmission timing of the continuous detection request S22, the wireless communication unit 46 of the monitoring device 40 continues the periodic transmission of the advance detection request S21 and the continuous detection request S22. This allows so-called asynchronous processing to continue.

[0105] On the other hand, the control device 50 maintains a sleep state and stops battery monitoring control while the ignition switch is turned off. Then, the control device 50 starts up when the ignition switch is turned on from the host ECU 16 of the vehicle 10.

[0106] When the control device 50 is started, the wireless communication unit 54 of the control device 50 starts scanning for devices present in the vicinity (S10). The wireless communication unit 54 of the control device 50 can scan for a predicted detection request S21 if it has been transmitted by the wireless communication unit 46 of the monitoring device 40. If the control device 50 is successful in scanning the predicted detection request S21, it reads transmission reservation timing information for a continuous detection request S22 contained in the predicted detection request S21.

[0107] This allows the wireless communication unit 54 of the control device 50 to know in advance that the next continuous detection request S22 will arrive from the wireless communication unit 46 of the monitoring device 40, and allows the wireless communication unit 54 of the control device 50 to wait for the timing at which the wireless communication unit 46 of the monitoring device 40 will transmit the continuous detection request S22. After that, when the wireless communication unit 54 of the control device 50 successfully detects the continuous detection request S22, it transmits a connection request S13.

[0108] After transmitting the continuous detection request S22, the wireless communication unit 46 of the monitoring device 40 receives a connection request S13 corresponding to the continuous detection request S22. When the wireless communication unit 46 of the monitoring device 40 receives the connection request S13 from the wireless communication unit 54 of the control device 50, it considers the connection process to be successful. Then, after receiving the connection request S13, a synchronization process of the connection process is started. The synchronization here means a process of waiting until a response is received after transmitting a request from either the wireless communication unit 54 of the control device 50 or the wireless communication unit 46 of the monitoring device 40. See the continuous connection response S17 by the wireless communication unit 54 of the control device 50 and the continuous connection request S23 by the wireless communication unit 46 of the monitoring device 40 shown in FIG. 7.

[0109] After the wireless communication unit 46 of the monitoring device 40 receives the connection request S13, the wireless communication unit 46 of the monitoring device 40 stops transmitting the advance detection request S21 and the continuous detection request S22. When the wireless communication unit 46 of the monitoring device 40 receives the connection request S13, it transmits a continuous connection request S23.

[0110] At least after synchronization, the communication speed should be faster than that during the asynchronous processing described above. It is preferable to set the communication speed of the advance notice detection request S21 slower than that of the continued connection request S23. In reality, it is preferable to communicate the advance notice detection request S21 and the continued connection request S23 at high speed. However, since this is a one-way broadcast communication from the monitoring device 40 to the control device 50, there is a risk of communication reliability decreasing. Therefore, by setting the communication speed of the advance notice detection request S21 slower than that of the continued connection request S23, it is possible to improve communication reliability when viewing the connection processing T1 and the connection processing T2 as a whole.

[0111] The continuous connection request S23 includes information necessary to complete the connection establishment before the periodic communication process S200, such as unique information, key information, and information for generating a key. In addition to information such as the key information, the continuous connection request S23 may also include a response to the connection request S13 described above. The wireless communication unit 46 of the monitoring device 40 sets the command of the continuous connection request S23 in a packet to perform synchronous communication with the wireless communication unit 54 of the control device 50, and receives a continuous connection response S17. The connection process S100 can be completed by repeating the continuous connection request S23 and the continuous connection response S17. The wireless communication unit 46 of the monitoring device 40 and the wireless communication unit 54 of the control device 50 perform pairing processing by the continuous connection request S23 and the continuous connection response S17 during the connection process S100 after the start of synchronous communication.

[0112] The pairing process is a process for performing encrypted data communication. The pairing process includes a process for exchanging unique information, and the unique information held by each of the devices may be exchanged and stored in the storage units 46a and 54a. After this process is performed, encryption using the exchanged unique information becomes possible. This unique information is key information of a common key or information for generating a key. This allows the connection process S100 to be completed as shown in S29 of FIG. 7.

[0113] <Details of the periodic communication process S200> When the wireless communication units 46 and 54 complete the connection process S100, they execute the periodic communication process S200. When the periodic communication process S200 starts, both the control device 50 and the monitoring device 40 switch to a battery control mode for controlling the battery state of the battery pack 12. The periodic communication process S200 is executed using one or more specific channels in the second channel group in the battery information communication frequency band.

[0114] In detail, the wireless communication unit 54 of the control device 50 first transmits an acquisition / transmission request S18 to the wireless communication unit 46 of the monitoring device 40 (S15). The wireless communication unit 46 of the monitoring device 40 transmits a request to acquire battery information to the battery monitoring unit 44 (S24). The battery monitoring unit 44 senses the battery cells 22 of the assembled battery 12 and acquires battery monitoring information such as the voltage of the battery cells 22 (S25). When the battery monitoring unit 44 acquires the battery monitoring information, it transmits the battery monitoring information to the wireless communication unit 46 of the monitoring device 40 as battery information (S26). When the wireless communication unit 46 of the monitoring device 40 receives the battery information, it transmits the battery information to the wireless communication unit 54 of the control device 50 (S27).

[0115] When the main microcomputer 53 of the control device 50 receives the battery information from the wireless communication unit 54, it determines whether the battery pack 12 is usable or not based on the battery information. If the battery pack 12 is not usable, it repeats obtaining the battery information and repeats the determination process until the battery pack 12 becomes usable. For example, if the main microcomputer 53 of the control device 50 cannot obtain the battery information from the monitoring device 40 no matter how many times it is executed, it determines that a communication abnormality has occurred and notifies the host ECU 16. When the battery pack 12 becomes usable, the main microcomputer 53 of the control device 50 executes a predetermined process such as outputting permission to start the vehicle 10 in S19. The microcomputer 45 of the monitoring device 40 may determine whether the battery pack 12 is usable or not. In this case, if the microcomputer 45 of the monitoring device 40 cannot obtain battery information from the battery monitoring unit 44 no matter how many times it is executed, it determines that a battery monitoring abnormality has occurred and notifies the control device 50 and the host ECU 16 via the wireless communication units 46, 54. In such a case, it then outputs a warning, for example to notify the driver.

[0116] When the main microcomputer 53 of the control device 50 confirms that the assembled battery 12 is usable, it permits activation of a contactor that connects the battery pack 11 to a built-in electric load (not shown) in a predetermined process of S19, or transmits an activation permission signal that permits activation of the contactor to the host ECU 16 of the vehicle 10. The wireless communication unit 54 may determine whether the assembled battery 12 is usable and execute the above control. That is, the main microcomputer 53 of the control device 50 outputs the activation permission signal for the vehicle 10 using the reception of the battery information as a trigger.

[0117] On the other hand, when the host ECU 16 receives the start permission signal, it recognizes that the battery pack 12 is in a normal state. The host ECU 16 also determines that the start conditions are satisfied based on vehicle information received from other ECUs and sensors (not shown) mounted in the vehicle 10, and if it determines that the vehicle 10 can be started normally, it starts the vehicle 10 and enables it to run on electric power. This allows the vehicle 10 to run safely.

[0118] In such periodic communication processing S200, it is desirable that the wireless communication unit 54 of the control device 50 assigns a time slot for receiving battery information to each of the multiple monitoring devices 40, and the wireless communication unit 46 of the monitoring device 40 assigns the battery information to the time slot and transmits the battery information at a higher communication speed than the communication speed when executing the connection processing T1 associated with the advance detection request S21. At this time, it is preferable to change the communication speed when transmitting the battery information to a higher speed so that it fits within the time slot. Here, the control device 50 has schedule information that goes around the monitoring devices 40, for example, information on the transmission and reception cycle, and uses this to assign a time slot to each monitoring device 40.

[0119] As a specific example, when the number of monitoring devices 40 is n, the transmission / reception period is T, the time slot per monitoring device 40 in one period T is T / n [sec], the communication speed is x [Mbps], and the maximum amount of data required for battery monitoring is D [Mbits], the allocation may be made so that D < x × T / n holds. However, D may include management data required for wireless communication. The time slot per monitoring device 40 is set so that one or more transmission packets and reception packets can be accommodated. In addition to the transmission packets and reception packets, a time margin may be provided in the time slot, and the time margin may be provided as an idle time. The data length of the battery information may be adjusted to match the length of the packet allocated to the time slot.

[0120] When the number of battery modules 20 to be monitored increases, there is a risk that large-capacity battery information cannot be communicated within a specified period within the time slots required by the battery monitoring system 1. The wireless communication unit 54 of the control device 50 can appropriately handle the transmission of large-capacity battery information data by controlling the time slots and communication speed for wirelessly transmitting the battery information.

[0121] For example, a hybrid electric vehicle (HEV) has a gasoline-powered engine and an electrically powered motor 15. On the other hand, a battery electric vehicle (BEV) has an electrically powered motor 15. Both the hybrid electric vehicle and the electrically powered vehicle have the battery monitoring system 1 described above.

[0122] When developers try to apply the know-how and technology cultivated in the development of hybrid vehicles to the development of electric vehicles, the number of battery modules 20 to be monitored will increase. In this way, when developing vehicles using different power systems in parallel or sequentially, the application of the time slot allocation technology described above can speed up the development while making use of the know-how.

[0123] <Summary of this embodiment> As described above, according to this embodiment, the wireless communication unit 46 of the monitoring device 40 sets the communication speed when performing a predetermined connection process, for example, transmitting the advance detection request S21, between the wireless communication unit 54 of the control device 50 and the wireless communication unit 54 of the control device 50 to be slower than the communication speed when transmitting battery information to the wireless communication unit 54 of the control device 50. Since the communication speed during the predetermined connection process is slower than the communication speed when communicating the battery information, the error rate during the connection process can be reduced and the reliability of communication during the predetermined connection process can be ensured. In addition, since the communication speed when communicating the battery information is faster than the communication speed during the predetermined connection process, the amount of data transmission of the battery information can be increased. In particular, the communication speed may be slow when the amount of communication data is small during the predetermined connection process before obtaining the battery information.

[0124] Furthermore, according to this embodiment, the wireless communication unit 46 of the monitoring device 40 transmits the advance detection request S21 using a non-battery information frequency band, and can transmit transmission reservation timing information for the continuous detection request S22 transmitted using the battery information frequency band to the wireless communication unit 54 of the control device 50. This allows the wireless communication unit 54 of the control device 50 to know in advance the timing for receiving the continuous detection request S22 and to secure in advance a schedule for receiving the continuous detection request S22, thereby improving the reliability of communication connection.

[0125] According to this embodiment, after the connection request S13 is received during the connection process S100, the wireless communication unit 46 of the monitoring device 40 changes the communication speed when transmitting battery information from the wireless communication unit 46 of the monitoring device 40 to the wireless communication unit 54 of the control device 50. As a result, when the connection request S13 is received during the connection process S100, the communication speed can be changed to a high speed, and the wireless communication unit 46 of the monitoring device 40 can transmit the battery information at a high speed.

[0126] The battery monitoring system 1 ensures the safety of the vehicle 10 by monitoring the battery information of all the battery modules 20. In this case, if the communication speed between the control device 50 and the multiple monitoring devices 40 is changed all at once, there is a concern that radio wave interference may occur inside the battery pack 11. In this embodiment, the wireless communication unit 46 of the monitoring device 40 switches the communication speed for the wireless communication unit 54 of the control device 50, and the communication speed is switched individually for each wireless communication unit 46 of the monitoring device 40.

[0127] As a specific example, in this embodiment, the wireless communication unit 46 of each of the multiple monitoring devices 40 can transmit the advance detection request S21 and the continuous detection request S22 at a convenient time in consideration of its own task schedule. In this way, when transmitting the continuous detection request S22, the wireless communication unit 46 of the monitoring device 40 can spontaneously switch the communication speed by using the second channel group. As a result, even after receiving the connection request S13, the communication speed can be switched to high-speed communication, and the battery information can be communicated at high speed. The wireless communication unit 46 of each of the monitoring devices 40 may not only switch to high-speed communication when transmitting the continuous detection request S22 after transmitting the advance detection request S21, but also switch to high-speed communication by using the second channel group in communication after receiving the connection request S13. Therefore, the communication speed can be switched at different timing for each of the wireless communication units 46 of the multiple monitoring devices 40, and the safety of the vehicle 10 can be further improved.

[0128] According to the first embodiment, communication is performed by dividing the entire frequency band into a first channel group of non-battery information communication frequency band and a second channel group of battery information communication frequency band. A communication method is determined in advance so that the communication speed is changed between the first channel group and the second channel group. This allows the communication speed to be easily changed.

[0129] Specifically, the wireless communication unit 46 of the monitoring device 40 communicates with the wireless communication unit 54 of the control device 50 by switching between a second channel group in the battery information communication frequency band for transmitting battery information to the wireless communication unit 54 of the control device 50 and a first channel group in the non-battery information communication frequency band, which is a band for transmitting an advance detection request S21 for publicizing the presence of the monitoring device 40. At this time, the wireless communication unit 46 of the monitoring device 40 transmits the advance detection request S21 in the non-battery information communication frequency band before transmitting a continuation detection request S22 for continuing connection in the battery information communication frequency band.

[0130] The wireless communication unit 46 of the monitoring device 40 transmits a predicted detection request S21, which notifies in advance of the transmission of the continued detection request S22, in a non-battery information frequency band, making it easier for the wireless communication unit 54 of the control device 50 to receive the continued detection request S22 in the battery information frequency band, thereby improving the reliability of the connection processing S100 between the wireless communication unit 46 of the monitoring device 40 and the wireless communication unit 54 of the control device 50.

[0131] The second channel group of the battery information frequency band has more channels than the first channel group of the non-battery information frequency band. Although the connection process S100 is performed using both the battery information frequency band and the non-battery information frequency band, the amount of communication used in the connection process S100 is greater for communication in the second channel group of the battery information frequency band than for communication in the first channel group of the non-battery information frequency band.

[0132] The non-battery information frequency band is made up of multiple channels, and the wireless communication unit 46 of the monitoring device 40 transmits a detection request using all of the multiple usable frequency bands that belong to the non-battery information frequency band. The wireless communication unit 46 of the monitoring device 40 may also select one or multiple frequency bands from the multiple frequency bands that belong to the non-battery information frequency band to transmit a detection request.

[0133] At this time, it is desirable for the wireless communication unit 46 of the monitoring device 40 to transmit the continuous detection request S22 at a higher speed than the advance detection request S21. Since the continuous detection request S22 is transmitted at a higher speed in the battery information frequency band, it is not necessary to switch the communication speed for each piece of data to be communicated. Since the communication speed is switched to high-speed communication at the time of the continuous detection request S22, it is possible to eliminate the need to change the speed in subsequent communications. This allows for an early transition to the regular communication process S200. As a result, the start-up time when performing battery monitoring is quick. This allows for optimal wireless communication between the wireless communication unit 46 of the monitoring device 40 and the wireless communication unit 54 of the control device 50. Furthermore, according to this embodiment, when the wireless communication unit 46 of the monitoring device 40 communicates asynchronously with the wireless communication unit 54 of the control device 50 and transmits an advance detection request S21 to announce its presence, the transmission is performed at a communication speed slower than the communication speed at which the signals required for the connection process S100 are received after transmitting the advance detection request S21 and synchronizing. When the wireless communication unit 54 of the control device 50 performs asynchronous communication with the wireless communication unit 46 of the monitoring device 40, when receiving a pre-announced detection request S21 transmitted from the wireless communication unit 46 of the monitoring device 40 to announce its own presence, the wireless communication unit 54 receives the request at a communication speed slower than the communication speed at which a signal required for connection processing S100 is received after receiving and synchronizing with the pre-announced detection request S21 from the wireless communication unit 46 of the monitoring device 40. This allows wireless communication between the wireless communication unit 46 of the monitoring device 40 and the wireless communication unit 54 of the control device 50 to be performed suitably.

[0134] In this embodiment, while the ignition switch is off, the monitoring device 40 continues to transmit detection requests while maintaining an activated state, and the control device 50 is in sleep mode. This allows the connection to be disconnected while the control device 50 is in sleep mode, thereby reducing the power consumption of the control device 50. Moreover, since the control device 50 can receive a detection request immediately after starting up, the control device 50 can quickly execute connection processing with the monitoring device 40, and can quickly start monitoring processing of the battery pack 12.

[0135] <Variation 1> For example, the control device 50 and the monitoring device 40 may both be activated with the ignition switch in the off state, and the communication frequency and communication speed may be made slower than normal while maintaining the connection. In this case, it is possible to maintain the connection state while reducing power consumption. In this case, when the ignition switch is turned on, the communication frequency may be set to the normal frequency by detecting the on signal, and the communication cycle may be returned to the normal cycle. In addition, the control device 50 and the monitoring device 40 may both be activated with the ignition switch turned off, and the communication speed may be maintained while maintaining the connection and reducing the frequency of communication compared to normal. This can speed up the start-up of the vehicle 10 without requiring a separate process for changing the communication speed when the ignition switch is turned on.

[0136] <Summary of this embodiment> Because the battery information changes from moment to moment, the amount of communication data of the battery information transmitted from the monitoring device 40 to the control device 50 becomes large. For this reason, rather than ensuring the reliability of each communication and reducing the number of packet retransmissions, it is better to increase the communication speed and the amount of transmitted data, even if this increases the number of packet retransmissions.

[0137] In general, if the packet communication speed is increased to increase the amount of battery information transmitted per unit time, the error rate of the packets increases. Therefore, in this embodiment, the first advance detection request S21 during connection processing is transmitted together with transmission reservation timing information indicating the timing for transmitting the subsequent continuous detection request S22.

[0138] As a result, the control device 50 can also receive in advance the scheduled transmission timing of the continuous detection request S22 when it receives the known signal from the monitoring device 40. Therefore, the control device 50 can appropriately manage the data communication schedule between the wireless communication unit 46 of the monitoring device 40 and the wireless communication unit 54 of the control device 50 by waiting to receive the continuous detection request S22 in accordance with the scheduled transmission timing, thereby reducing the packet error rate.

[0139] <Variation 2> It is desirable that the wireless communication unit 46 of the monitoring device 40 and the wireless communication unit 54 of the control device 50 can reliably execute the connection process S100 for establishing a connection. This is because it is desirable to continue to monitor the state of the battery modules 20 of the assembled battery 12 even when the vehicle is stopped or running, and if an abnormality occurs in the assembled battery 12, the running safety of the vehicle 10 will deteriorate.

[0140] A non-battery information frequency band that does not transmit battery information may be prepared exclusively to transmit both the advance detection request S21 and the continuous detection request S22 of the connection process S100. When the connection process S100 is performed using a non-battery information communication frequency band, the number of packets related to battery information is small and communication can be performed without packets related to battery information dominating traffic. In this case, the reliability of the connection process S100 can be improved. <Variation 3> In the above embodiment, the connection process S100 is executed when the vehicle 10 is started from a stopped state, but the connection process S100 may be executed to maintain the connection state even when the vehicle 10 is stopped. In this case, the connection state is maintained and established when the vehicle 10 is started, so the vehicle 10 can be started up quickly. In addition, since the connection state is maintained, the control device 50 can control the multiple monitoring devices 40. For this reason, the wireless communication unit 46 of the monitoring device 40 can also instruct the wireless communication unit 54 of the control device 50 to change the communication speed at which the battery information is transmitted.

[0141] Second embodiment The second embodiment will be described with reference to Fig. 9 to Fig. 11. Differences from the previous embodiment will be described. In this embodiment, the wireless communication unit 46 of the monitoring device 40 transmits battery information in the periodic communication process S200, and also transmits battery information to the wireless communication unit 54 of the control device 50 during execution of the connection process S100.

[0142] As described in the above embodiment, the wireless communication unit 46 of the monitoring device 40 transmits a plurality of packets to the wireless communication unit 54 of the control device 50 in the connection process S100. The wireless communication unit 46 of the monitoring device 40 transmits a portion of the packets to be transmitted in the connection process S100 by including battery information. One or a plurality of packets including the battery information may be used for transmission, and the transmission mode is not particularly limited. The wireless communication unit 46 of the monitoring device 40 may include the battery information in the packets in the connection process S100.

[0143] When the monitoring device 40 executes a detection operation, it is desirable to include the battery information in a packet of a continuous connection request S23 to the control device 50. Alternatively, the battery information may be included in a packet of the continuous detection request S22, or in a packet to be transmitted together with the packet of the continuous detection request S22. The battery information may be communicated ahead of the transmission of the battery information in the periodic communication process S200.

[0144] The wireless communication unit 46 of the monitoring device 40 may include the battery information in a packet during the pairing process. The monitoring device 40 may include the battery information in a packet to be transmitted after the exchange of the unique information is completed. The monitoring device 40 may include the battery information in a packet to be transmitted before the exchange of the unique information is completed during the connection process T3, which is a part of the connection process S100, or may transmit the battery information after the exchange of the unique information is completed. The battery information may be included in a packet for exchanging the unique information. By transmitting the battery information ahead of schedule, the vehicle 10 can be started up quickly.

[0145] A specific example will be described below with reference to the drawings. The process up to when the wireless communication unit 54 of the control device 50 is synchronized with the wireless communication unit 46 of the monitoring device 40 is the same as in the first embodiment described above, so a description thereof will be omitted.

[0146] As shown in Fig. 9, the wireless communication unit 54 of the control device 50 transmits a connection request S13 to the wireless communication unit 46 of the monitoring device 40, and the wireless communication unit 46 of the monitoring device 40 transmits a continuous connection request S23 to the wireless communication unit 54 of the control device 50 in response to the connection request S13. Battery information is transmitted while performing various continuous connection processes T3 such as pairing processes. For example, see the battery information communication process T3a in Figs. 9 and 11. Note that the connection process T3 indicates one or more round-trip connections of the continuous connection request S23 and the continuous connection response S14, or the continuous connection request S28 and the continuous connection response S17 shown in Fig. 9.

[0147] In the battery information communication process T3a, the wireless communication unit 54 of the control device 50 first transmits an acquisition / transmission request S15 to the wireless communication unit 46 of the monitoring device 40. Here, the wireless communication unit 54 of the control device 50 communicates at a high communication speed on one or more second channels of the battery information wireless communication frequency band. The wireless communication unit 46 of the monitoring device 40 transmits an acquisition request S24 for battery information to the battery monitoring unit 44.

[0148] The battery monitoring unit 44 senses the battery pack 12 in S25 and acquires battery monitoring information such as the voltage of the battery cells 22 as battery information. When the battery monitoring unit 44 acquires the battery information, it transmits the battery information to the wireless communication unit 46 of the monitoring device 40 as monitoring data (S26). When the wireless communication unit 46 of the monitoring device 40 receives the battery information, it transmits the battery information to the wireless communication unit 54 of the control device 50 (S27). The battery information may be transmitted collectively in one packet, but since the amount of data is relatively large, it is divided into packets and transmitted wirelessly. In this case, the battery information may be divided into packets and transmitted wirelessly. Alternatively, it does not have to be divided.

[0149] At this time, the wireless communication unit 54 of the control device 50 may instruct the wireless communication unit 46 of the monitoring device 40 to transmit the battery information between the multiple connection processes T3. Then, the wireless communication unit 46 of the monitoring device 40 transmits the battery information during the period in which the connection process T3 with the control device 50 is being performed. By transmitting the battery information during the connection process T3, the start-up of the vehicle 10 can be accelerated. As a result, the discomfort felt by the user due to a start-up delay when starting up the vehicle 10 can be suppressed.

[0150] The wireless communication unit 46 of the monitoring device 40 may transmit information required to monitor the battery module 20 of the assembled battery 12 before completing the connection process S100. The information required to monitor the battery module 20 of the assembled battery 12 targets some or all of the battery information obtainable from the battery monitoring unit 44. Examples of this battery information include information on the cell voltage of the battery cell 22, temperature information, and information on the current flowing through the assembled battery 12. As shown in FIG. 10, it is desirable to transmit the above-mentioned battery information in a divided manner during a plurality of connection processes T3. At this time, the wireless communication unit 46 of the monitoring device 40 may divide and transmit the data of the battery information so that it fits into the assigned time slot. At this time, it is desirable to divide the data of the battery information for each meaningful division data. A meaningful division refers to data in a unit that can be recognized as battery information. The data of the battery information does not have to be divided.

[0151] If the vehicle 10 is, for example, an electric vehicle, the electric vehicle runs using power from the battery pack 12. For this reason, battery information is required when starting the electric vehicle, and it is important to ensure the safety of the vehicle 10 that the starting of the vehicle 10 is permitted only when it is determined that the battery information is operating normally.

[0152] The control device 50 and the host ECU 16 may start the vehicle 10 on one condition that the battery pack 12 is operating normally. As shown in Fig. 11, the vehicle 10 is started on the condition that battery information is received, but the host ECU 16 may also start the vehicle 10 on the condition that vehicle information received from other ECUs and sensors (not shown) mounted in the vehicle 10 satisfies a start-up condition in addition to the normal operating condition of the battery pack 12. In this case, as shown in Fig. 11, the vehicle 10 can be started early while maintaining safety while the connection process T3 is continuing.

[0153] In this embodiment, the wireless communication unit 46 of the monitoring device 40 does not need to set data related to timing in the continuous connection requests S23 and S28. This allows the control device 50 to set battery information in the data field of the packet, making it possible to effectively use the data field of the packet.

[0154] Since the communication schedule for the continuous connection requests S23, S28 is managed in advance between the wireless communication unit 54 of the control device 50 and the wireless communication unit 46 of the monitoring device 40, large data can be included in packets and transmitted during the continuous connection requests S23, S28. After that, the monitoring device 40 executes the periodic communication process S200, but the battery information, which is a large amount of data, can be transmitted to the control device 50 ahead of the execution of the periodic communication process S200.

[0155] According to this embodiment, the wireless communication unit 46 of the monitoring device 40, while performing connection processing with the wireless communication unit 54 of the control device 50, sets the communication speed when including battery information in a packet and transmitting it to the wireless communication unit 54 of the control device 50 to be the same as the communication speed when transmitting the battery information to the wireless communication unit 54 of the control device 50 after the connection processing S100. This allows the battery information to be transmitted at high speed even when transmitting the battery information during the connection processing S100 before the execution of the periodic communication processing S200.

[0156] <Modification of the activation timing of the battery monitoring unit 44> Here, modified examples of the start-up timing of the battery monitoring unit 44 will be described with reference to Fig. 5 and Fig. 9. As shown in Fig. 5, the wireless communication unit 46 may have a function of serving as a start-up circuit 46b for the battery monitoring unit 44. The start-up circuit 46b is configured to output a start-up signal to the battery monitoring unit 44 upon receiving a connection request S13 from the wireless communication unit 54 of the control device 50.

[0157] 9, the wireless communication unit 54 of the control device 50 transmits a connection request S13 to the wireless communication unit 46 of the monitoring device 40, and at the timing when the control device 50 and the monitoring device 40 become synchronized, the startup circuit 46b of the wireless communication unit 54 transmits a startup signal to the battery monitoring unit 44. The battery monitoring unit 44 can be started up in S30 of FIG.

[0158] The wireless communication unit 54 of the control device 50 may issue an instruction to start the battery monitoring unit 44 to the wireless communication unit 46 of the monitoring device 40 at the same time as the connection request S13. Alternatively, the timing at which the wireless communication unit 54 transmits the activation signal to the battery monitoring unit 44 may be the timing immediately before the wireless communication unit 46 of the monitoring device 40 transmits the acquisition instruction, that is, the timing at which the wireless communication unit 46 of the monitoring device 40 receives the request data from the wireless communication unit 54 of the control device 50.

[0159] When the wireless communication unit 46 of the monitoring device 40 processes a connection with the wireless communication unit 54 of the control device 50, it is preferable to switch the communication speed to a higher speed than that used for the connection process before the battery monitoring unit 44 is started. By switching the communication speed to a higher speed communication speed before the battery monitoring unit 44 is started, battery information can be quickly transmitted to the control device 50. As a result, the start-up of the vehicle 10 is quicker, and the discomfort felt by the user due to a start-up delay can be reduced.

[0160] In the flow of Fig. 9, when the power supply of the battery monitoring unit 44 is started up as shown in S30 of Fig. 9, high-speed communication is already being performed using the second channel of the battery information communication frequency band, so there is no need to increase the speed before or after this. If low-speed communication is being performed, it is advisable to switch to high-speed communication before the battery monitoring unit 44 is started up (S30).

[0161] Also, the activation may be delayed from the timing of S30 shown in Fig. 9. For example, the wireless communication unit 46 of the monitoring device 40 may output an activation signal to the battery monitoring unit 44 of the monitoring device 40 at a timing immediately before receiving the acquisition / transmission request S18 from the wireless communication unit 54 of the control device 50, thereby activating the battery monitoring unit 44.

[0162] This embodiment also provides the same effects as the above-mentioned embodiment. In addition, when the battery information is sent alternately with the continuous detection request S22 during the connection process S100, the communication speed for sending the battery information can be increased to ensure communication reliability. By optimizing the communication schedule, the communication reliability can be improved while increasing the number of communications. The details of the start-up timing of the battery monitoring unit 44 described in this embodiment may be applied to other embodiments, for example, any of the first, third to ninth embodiments.

[0163] Third embodiment A third embodiment will be described with reference to FIG. 12. In this embodiment, another mode of the method for changing the communication speed will be described. For example, even when a battery monitoring system 1 is applied that communicates both battery information and non-battery information using the same channel group of one or more channels, the communication speed can be changed. Differences from the previous embodiments will be described. In this embodiment, the connection processes T1 and T2 are changed to connection process T2a, so this will be described first.

[0164] <About the connection process S100> The wireless communication unit 46 of the monitoring device 40 continues to periodically transmit the detection request S22a on a predetermined group of channels while processing other scheduled tasks, until it receives a connection request S13 from the wireless communication unit 54 of the control device 50.

[0165] 12 is a notifying command for notifying the outside of the existence of the wireless communication unit 46 of the monitoring device 40, and also indicates a request command for receiving a connection request S13 from the wireless communication unit 54 of the control device 50. The wireless communication unit 46 of the monitoring device 40 continues to periodically transmit the detection request S22a even when the ignition switch is off.

[0166] The detection request S22a continues to be periodically transmitted by asynchronous processing so that the wireless communication unit 54 of the control device 50 present in the vicinity detects its own presence. The wireless communication unit 46 of the monitoring device 40 continues to transmit the detection request S22a without identifying a communication partner, making it difficult to establish a connection. For this reason, it is preferable to transmit at a communication speed slower than the communication speed when communicating battery information. The wireless communication unit 46 of the monitoring device 40 should identify the communication partner, establish a connection, synchronize, and then communicate at a high speed. This makes it possible to realize communication suitable for the characteristics of communication of battery information with a large amount of data, for example, the periodic communication process S200, and the connection process S100 with a small amount of data.

[0167] On the other hand, the control device 50 maintains a sleep state and stops battery monitoring control while the ignition switch is turned off. Then, the control device 50 starts up when the ignition switch is turned on from the host ECU 16 of the vehicle 10.

[0168] When the control device 50 is started, the wireless communication unit 54 of the control device 50 starts scanning for devices present in the vicinity (S10). The wireless communication unit 54 of the control device 50 can scan for a detection request S22a if it has been transmitted by the wireless communication unit 46 of the monitoring device 40. If the control device 50 succeeds in detecting the detection request S22a, it transmits a connection request S13.

[0169] After transmitting the detection request S22a, the wireless communication unit 46 of the monitoring device 40 receives a connection request S13 corresponding to the detection request S22a. When the wireless communication unit 46 of the monitoring device 40 receives the connection request S13 from the wireless communication unit 54 of the control device 50, it considers the connection process to be successful. Then, after receiving the connection request S13, it starts a synchronization process of the connection process. See the connection process T3 shown in FIG. 12, i.e., the continuous connection response S14 by the wireless communication unit 54 of the control device 50 and the continuous connection request S23 by the wireless communication unit 46 of the monitoring device 40.

[0170] <How to change speed and when to change speed> For example, it is advisable to change the communication speed by performing packet communication immediately after synchronization, as shown in Fig. 12. Specifically, immediately after synchronization, the wireless communication unit 46 of the monitoring device 40 executes a speed change process Sp1 with the wireless communication unit 54 of the control device 50. In the speed change process Sp1, the wireless communication unit 54 of the control device 50 sets data indicating a speed change instruction Sa for changing from a low speed to a high speed in a flag packet Pa and transmits the set data.

[0171] When the wireless communication unit 46 of the monitoring device 40 receives the speed change instruction Sa, it changes the communication speed to a high speed. The speed change instruction Sa command contained in the flag packet Pa may be transmitted sequentially between packets P1 and P2 of the connection process T3 transmitted to the wireless communication units 46 of the multiple monitoring devices 40, as shown in Fig. 13. Also, as shown in Fig. 14, a flag F may be attached to a data packet D and transmitted.

[0172] Thereafter, the wireless communication unit 46 of the monitoring device 40 can also perform high-speed communication with the wireless communication unit 54 of the control device 50 in the connection process T3. As shown in Fig. 12, high-speed communication is also possible in the periodic communication process T4 (periodic communication process S200) after the connection process S100 is completed.

[0173] The timing for changing the communication speed between the wireless communication units 46, 54 may be any time before the wireless communication unit 46 of the monitoring device 40 transmits the battery information. <Variation 1> 15 and 16, the wireless communication unit 46 of the monitoring device 40 can transmit the battery information ahead of the periodic communication process S200 by executing the battery information communication process T3a before completing the connection process S100 with the wireless communication unit 54 of the control device 50 (S29). At this time, the battery information can be communicated ahead of time at high speed, achieving the same effects as the above-described embodiment. Note that it is not necessary to communicate the battery information ahead of time, ahead of the periodic communication process S200.

[0174] <Variation 2> 17, the wireless communication unit 46 of the monitoring device 40 may execute a speed change process Sp1 while executing multiple connection processes T3 after synchronizing with the wireless communication unit 54 of the control device 50. That is, as a part of the connection process T3 after synchronization, the speed change process Sp1 may be executed after repeating the continued connection request S23 and the continued connection response S14 one or more times, and further executing the continued connection request S28 and the continued connection response S17 of another connection process T3 one or more times. This provides the same effects as the above-mentioned embodiment.

[0175] Furthermore, the wireless communication unit 46 of the monitoring device 40 can transmit the battery information ahead of the periodic communication process S200 by executing the battery information communication process T3a before completing the connection process S100 with the wireless communication unit 54 of the control device 50 (S29). At this time, the battery information can be communicated ahead of time at high speed, achieving the same effects as the above-described embodiment. Note that it is not necessary to communicate the battery information ahead of time, ahead of the periodic communication process S200.

[0176] <Variation 3> 18 and 19, the wireless communication unit 46 of the monitoring device 40 may execute a speed change process Sp1 after synchronizing with the wireless communication unit 54 of the control device 50 and completing the connection process S100 (S29) and before executing the periodic communication process T4, i.e., the periodic communication process S200. This provides the same effects as the above-described embodiment.

[0177] <Modification 4> In the above, the wireless communication unit 54 of the control device 50 is the main entity that issues a speed instruction and executes the speed change process Sp1, but this is not limited to the above. Alternatively, instead of the speed change process Sp1, as shown in Fig. 20, the wireless communication unit 46 of the monitoring device 40 may execute the speed change process Sp2 as the main entity that requests a speed instruction.

[0178] That is, in the speed change process Sp2, the wireless communication unit 46 of the monitoring device 40 transmits a speed change instruction request Sa0 to change the communication speed from a low speed to a high speed to the wireless communication unit 54 of the control device 50. The wireless communication unit 54 of the control device 50 receives the speed change instruction request Sa0 from the wireless communication unit 46 of the monitoring device 40. Then, the wireless communication unit 54 of the control device 50 transmits a speed change instruction Sa to the wireless communication unit 46 of the monitoring device 40. The wireless communication unit 46 of the monitoring device 40 changes the communication speed from a low speed to a high speed. This makes it possible to execute a speed change similar to the speed change process Sp1 of the above-described embodiment.

[0179] According to this embodiment, even in a battery monitoring system 1 that communicates both non-battery information and battery information over a channel group consisting of the same one or more channels, the communication speed can be changed between the wireless communication unit 54 of the control device 50 and the wireless communication unit 46 of the monitoring device 40. According to this embodiment, when transmitting a detection request S22a to establish a connection when executing asynchronously with the wireless communication unit 54 of the control device 50, the detection request S22a is transmitted at a communication speed slower than the communication speed when transmitting a signal required for connection processing after transmitting and synchronizing the detection request S22a. As a result, the same effects as those of the above-mentioned embodiment are achieved. Furthermore, according to this embodiment, when the wireless communication unit 54 of the control device 50 receives the detection request S22a transmitted from the wireless communication unit 46 of the monitoring device 40 for establishing a connection asynchronously with the wireless communication unit 46 of the monitoring device 40, the wireless communication unit 54 receives the detection request S22a at a communication speed slower than the communication speed at which a signal required for connection processing is received after receiving and synchronizing the detection request S22a from the wireless communication unit 54 of the monitoring device 40. As a result, the same effects as those of the above-described embodiment are achieved.

[0180] (Fourth embodiment) The fourth embodiment will be described with reference to Fig. 21. In this embodiment, as a specific example of the third embodiment, a form will be described in which the wireless communication unit 54 of the control device 50 proactively changes the communication speed with the wireless communication units 46 of the multiple monitoring devices 40. In the following description, the transmission of information from the control device 50 to the multiple monitoring devices 40 will be referred to as downstream communication, and the transmission of information from the monitoring device 40 to the control device 50 will be referred to as upstream communication.

[0181] The wireless communication unit 54 of the control device 50 is configured to communicate with the multiple monitoring devices 40 individually. The wireless communication unit 54 of the control device 50 is configured to be able to individually switch the communication speed from the wireless communication unit 46 of the monitoring device 40 to the wireless communication unit 54 of the control device 50. If the wireless communication unit 54 of the control device 50 has a function of independently instructing to switch the communication speed, the communication speed can be individually switched for each monitoring device 40 by, for example, unicast communication. If the wireless communication unit 54 of the control device 50 is configured to be able to independently control the switching of the communication speed, it can also simultaneously instruct the wireless communication units 46 of all the multiple monitoring devices 40 to change the communication speed by, for example, broadcast communication, as shown in the speed change instruction Sa of FIG. 21. In addition, the communication speed from the wireless communication unit 54 of the control device 50 to the wireless communication unit 46 of the monitoring device 40 may be individually changed and switched. That is, the communication speed between the wireless communication unit 54 and the wireless communication unit 46 may be changed and switched in either direction.

[0182] The wireless communication unit 54 of the control device 50 may switch to communication of battery information from the monitoring device 40 that has completed the connection process S100 and continue the communication, for example, by executing the periodic communication process S200. By switching to high-speed communication one by one from the monitoring device 40 that has completed the connection process S100, the wireless communication unit 54 of the control device 50 is less susceptible to radio wave interference caused by diffuse reflection of radio waves inside the battery pack 11 formed of an electromagnetic reflection material, compared to a configuration in which high-speed communication is switched to all at once after the connection process of all the monitoring devices 40 is completed. This allows the communication speed to be suitably changed. Alternatively, high-speed communication may be switched to all at once for all the monitoring devices 40 after the connection process of all the monitoring devices 40 is completed.

[0183] In addition, while switching the communication speed from the wireless communication unit 46 of another monitoring device 40 to the wireless communication unit 54 of the control device 50, it is preferable not to switch the communication speed from the wireless communication unit 54 of the control device 50 to the wireless communication units 46 of the other multiple monitoring devices 40.

[0184] Downstream communication is one-to-many communication, and in order to switch the communication speed with each monitoring device 40, it is necessary to perform switching control for each monitoring device 40. In contrast, in this embodiment, even while the communication speed of the upstream communication from the multiple monitoring devices 40 to the control device 50 is being switched, communication can be performed without switching the communication speed of the downstream communication. Therefore, it does not take time to complete the downstream communication for each monitoring device 40, and battery monitoring can be started early. As a result, the start-up of the vehicle 10 can be made faster, and discomfort to the user can be suppressed.

[0185] Fifth embodiment The fifth embodiment will be described with reference to Fig. 22 and Fig. 23. Since this embodiment is a modification of the first or second embodiment, the configuration of the first or second embodiment will be applied and the differences from the first or second embodiment will be described. As described in the first and second embodiments, as shown in Fig. 22, the wireless communication unit 46 of the monitoring device 40 switches to and sets a first channel group in the non-battery information communication frequency band (T0a) in the asynchronous processing of the connection processing S100, and transmits a notice detection request S21.

[0186] Thereafter, the wireless communication unit 46 of the monitoring device 40 switches to the second channel group in the battery information communication frequency band (T0b) and transmits a continuous detection request S22. When the wireless communication unit 46 of the monitoring device 40 receives a connection request S13 (YES in S22a), it considers that synchronization has been achieved, and then proceeds to a connection process T3 and then to a periodic communication process S200.

[0187] In the periodic communication processing S200 described in the first or second embodiment above, the wireless communication unit 46 of the monitoring device 40 communicates battery information with the wireless communication unit 54 of the control device 50 using the second channel group in the battery information communication frequency band (S33).

[0188] At this time, if the wireless communication unit 46 of the monitoring device 40's own battery information is not received by the wireless communication unit 54 of the control device 50, the wireless communication unit 46 of the monitoring device 40 switches from the second channel group of the battery information communication frequency band to the first channel group of the non-battery information communication frequency band and executes connection processing S100 with the wireless communication unit 54 of the control device 50.

[0189] For example, when communication becomes impossible due to the deterioration of the radio wave propagation environment, the battery information may not be received by the wireless communication unit 54 of the control device 50. In this case, the wireless communication unit 46 of the monitoring device 40 starts a timer at the timing when the battery information is transmitted in S33, and waits while measuring a certain period of time.

[0190] If the wireless communication unit 46 of the monitoring device 40 does not receive the battery information receipt response S33a and is unable to confirm receipt even after a predetermined period of time has elapsed at T4a, it determines that the battery information has not been received and that an unintended communication interruption has occurred. In this case, the wireless communication unit 46 of the monitoring device 40 switches from the second channel group of the battery information communication frequency band to the first channel group of the non-battery information communication frequency band, and executes a connection process S100 with the wireless communication unit 54 of the control device 50. This allows recovery from the unintended communication interruption.

[0191] Note that communication may also be interrupted due to an external interrupt factor such as an external user operation, for example, when the host ECU 16 detects that the ignition switch is off and the control device 50 recognizes that the ignition switch has been detected. In this case as well, if the wireless communication unit 46 of the monitoring device 40 does not receive a battery information receipt response S33a and is unable to confirm receipt even after a predetermined period of time has elapsed at T4a, it determines that the battery information has not been received.

[0192] The wireless communication unit 46 of the monitoring device 40 switches from the second channel group of the battery information communication frequency band to the first channel group of the non-battery information communication frequency band to perform connection processing with the wireless communication unit 54 of the control device 50. This makes it possible to restore connection establishment after an unintended communication interruption. As a result, if there is a monitoring device 40 that cannot receive important cell voltage information, among other battery information, for a certain period of time, the connection processing S100 can be reliably performed by transmitting a pre-announced detection request S21 using the first channel group of the non-battery information communication frequency band, and reconnection can be achieved with a high probability.

[0193] As another example, as in the periodic communication process S200 shown in Fig. 23, when the wireless communication unit 54 of the control device 50 is receiving the cell voltage of the battery pack 12 as battery information from the wireless communication unit 46 of the monitoring device 40, the same can be applied to a case where the wireless communication unit 54 has not received the battery information of the cell voltage from the wireless communication unit 46 of the monitoring device 40 for a certain period of time. In this case, it is preferable for the wireless communication unit 54 of the control device 50 to execute the connection process S100 with the wireless communication unit 46 of the monitoring device 40 at a slower communication speed for battery information than with the wireless communication unit 46 of the monitoring device 40 other than the monitoring device 40 from which the cell voltage was not received.

[0194] If the wireless communication unit 54 of the control device 50 does not receive the cell voltage as battery information, the wireless communication unit 46 of the monitoring device 40 will not transmit the receipt response S19a either. The same applies if the wireless communication unit 46 of the monitoring device 40 cannot receive the receipt response S33a even though the wireless communication unit 54 of the control device 50 transmits the receipt response S19a. In either case, since the wireless communication unit 46 of the monitoring device 40 does not receive the receipt response S33a, it determines that a timeout has occurred and that there is no response, and proceeds to the connection process S100.

[0195] Among the battery information, the cell voltage of the battery cell 22 is particularly important. When communication of the battery information is difficult, it is advisable to slow down the communication speed to ensure that the cell voltage is transmitted. As described in this embodiment, even if the wireless communication unit 54 of the control device 50 is unable to receive the signal for a certain period of time at T4b and the session connection is disconnected, it is advisable to execute the connection process S100 to slow down the communication speed. By performing this process, it is possible to increase the reliability of establishing a connection for communication between the wireless communication unit 46 of the monitoring device 40 and the wireless communication unit 54 of the control device 50. As a result, it is possible to reliably transmit information on the cell voltage, which is particularly important among the battery information.

[0196] Furthermore, if the wireless communication unit 46 of the monitoring device 40 retransmits the predicted detection request S21 but it is not accepted by the control device 50 and communication cannot be established, and if communication cannot be established even after waiting for a predetermined period of time and a timeout occurs, a disconnection signal to voluntarily disconnect the connection process S100 may be transmitted to perform the disconnection process Sz, as shown in Figure 23.

[0197] Also, the wireless communication unit 46 of a specific monitoring device 40 may transmit battery information to the wireless communication unit 54 of the control device 50 via the wireless communication unit 46 of a monitoring device 40 other than its own monitoring device 40. In this case, since the signal transmission path length becomes long, it is desirable to communicate at a high speed rather than at a low speed.

[0198] Sixth embodiment The sixth embodiment will be described with reference to Fig. 24 and Fig. 25. Since this embodiment is a modification of the first or second embodiment, the description will be given by applying the configuration of the first or second embodiment, and the differences from the first embodiment will be described.

[0199] <Equalization control> While the ignition switch is turned off, the control device 50 executes equalization control for each of the battery cells 22 constituting the battery module 20 of the assembled battery 12 to equalize the cell voltages.

[0200] The main microcomputer 53 of the control device 50 has a function as an equalization control unit 53a, measures the time period for equalization control using a timer, and periodically returns from a sleep state to execute equalization control of the assembled battery 12. The monitoring device 40 has an equalization circuit (not shown) for equalizing the cell voltages of the battery cells 22.

[0201] When the main microcomputer 53 receives the battery information of the cell voltages from the monitoring device 40, it sets the lowest voltage value of the cell voltage as the target value and executes the equalization control, as shown in Fig. 24. Furthermore, when the main microcomputer 53 receives the battery information of the cell voltages from the monitoring device 40, it may calculate the average value of the voltage values ​​of the cell voltages and execute the equalization control by setting the average value as the target value, as shown in Fig. 25. When the control device 50 ends the equalization control, it returns to the sleep mode again.

[0202] Although the control device 50 has been described as returning to the sleep mode when the equalization control ends, the present invention is not limited to this. Alternatively, the control device 50 may receive the cell voltage states of the battery cells 22 / battery modules 20 from the monitoring device 40, and go to sleep after confirming that the battery cell 22 / battery module 20 that is the furthest from the target cell voltage value has finished discharging or charging.

[0203] The control device 50 may go to sleep after transmitting a signal instructing each battery cell 22 / battery module 20 to indicate a target value. The main microcomputer 53 of the control device 50 may issue an instruction to acquire battery information of each battery cell 22 / battery module 20 after equalization control by the equalization control unit 53a, and may go to sleep after confirming the battery information.

[0204] While the ignition switch is off, it is desirable to communicate a small amount of information at a relatively low speed in order to reduce the error rate per communication. However, when the control device 50 performs equalization control, the wireless communication unit 46 of the monitoring device 40 transmits the amount of transmission data of battery information such as the cell voltage of each battery cell 22 to the wireless communication unit 54 of the control device 50, and the control device 50 collects the target battery information.

[0205] The control device 50 then transmits information indicating that the battery information has been collected to the host ECU 16. The host ECU 16 outputs an equalization instruction based on the collected information to the monitoring device 40 via the control device 50. This enables the monitoring device 40 to equalize the cell voltages of the battery cells 22. Therefore, in order to increase the frequency of the equalization process and thereby improve the reliability of the battery pack 12, it is preferable to increase the amount of transmitted data of battery information per unit time as much as possible.

[0206] It is desirable that the communication speed of the wireless communication unit 54 of the control device 50 for receiving battery information from the wireless communication unit 46 of the monitoring device 40 during the equalization process instructing the equalization process when the vehicle 10 is stopped is faster than the speed at which the advance detection request S21 is received from the wireless communication unit 46 of the monitoring device 40 when the vehicle 10 is stopped. This enables the host ECU 16 to quickly output an equalization command based on the information, thereby increasing the frequency with which the equalization process is performed and improving the operational reliability of the battery pack 12.

[0207] Furthermore, when performing the equalization process, it is advisable to increase the number of communications per unit time that the wireless communication unit 46 of the monitoring device 40 transmits to the wireless communication unit 54 of the control device 50, thereby increasing the communication speed. This makes it possible to increase the frequency with which the equalization process is performed per unit time, thereby improving the system reliability of the entire battery monitoring system 1.

[0208] Even if the vehicle 10 is stopped, if the vehicle 10 needs to monitor the battery for equalization, it is desirable to communicate at a high communication speed. Also, the need to monitor the battery pack 12 is not limited to the above-mentioned cases. For this reason, it is desirable to be able to communicate battery information at high speed when the battery pack 12 needs to be monitored.

[0209] For example, when a HEMS (not shown) is connected by wire or wirelessly to the battery monitoring system 1, a trigger that indicates the need for battery monitoring may be provided from the external HEMS. HEMS is an abbreviation for Home Energy Management System.

[0210] The HEMS periodically outputs a start-up trigger to the control device 50 via the host ECU 16 of the vehicle 10. The control device 50 can start the vehicle 10 by acquiring battery information from the monitoring device 40. At this time, as described in the above embodiment, it is desirable to communicate the battery information at high speed while adjusting the communication speed in the connection process S100 and the periodic communication process S200.

[0211] Seventh embodiment The seventh embodiment will be described with reference to Fig. 26. As shown in Fig. 26, the monitoring device 40 may be disposed on each of the upper surfaces of the battery modules 20. The monitoring device 40 is disposed at the midpoint of the battery modules 20 extending in the Y direction, and detection lines L are connected in both directions in the Y direction. Fig. 26 shows a form in which the monitoring device 40 is disposed at the center in the Y direction on the upper surface of each battery module 20, but the monitoring device 40 does not necessarily have to be disposed at the center in the Y direction. It may be disposed at any position as long as it is at the midpoint in the Y direction, not limited to the center in the Y direction.

[0212] The monitoring devices 40 are each equipped with a battery monitoring unit 44, and are configured by connecting detection lines L to the battery monitoring units 44. The battery monitoring units 44 are configured using an integrated circuit device with one or more monitoring ICs. The battery monitoring units 44 can detect the voltages of the multiple battery cells 22 in each battery module 20 via the detection lines L. The upper end of the monitoring device 40 is positioned to protrude in the Z direction beyond the upper end of the bus bar cover 27.

[0213] As in the above-described embodiment, the control device 50 is equipped with a wireless communication unit 54, and the monitoring device 40 is equipped with a wireless communication unit 46. The housing 30 has a gap at the upper inner end in the Z direction, which gap serves as a wireless propagation space S2. The control device 50 can wirelessly communicate with the multiple monitoring devices 40 through the propagation space S2. If the wireless communication unit 54 of the control device 50 can communicate with the wireless communication units 46 of the multiple monitoring devices 40 by direct waves, a good wireless propagation environment can be maintained.

[0214] Since the monitoring device 40 is disposed protruding from the upper end of the bus bar cover 27, wireless communication between the control device 50 and the monitoring device 40 is facilitated by propagating through the propagation space S2 above the upper end of the bus bar cover 27. According to this embodiment, since the monitoring device 40 does not need to be disposed on the Y-direction side surface of the battery module 20, the Y-direction width of the housing 30 can be reduced, and the housing 30 can be made smaller.

[0215] Eighth embodiment The eighth embodiment will be described with reference to Fig. 27. As shown in Fig. 27, the monitoring device 40 is disposed along the Y-direction side surface of each battery module 20. The monitoring device 40 includes a wireless communication unit 46 and a battery monitoring unit 44, and the battery monitoring unit 44 is connected to a detection line L. Each monitoring device 40 may include a plurality of battery monitoring units 44. The battery monitoring unit 44 is connected to one end of the detection line L extending in the Y direction, thereby enabling the voltage of the battery cell 22 to be detected.

[0216] As in the first embodiment, a space S1 is provided on the inner side of the first wall surface 30a of the housing 30. The wireless communication unit 54 of the control device 50 can wirelessly communicate with the wireless communication units 46 of the multiple monitoring devices 40 by using the space S1 as a pseudo-waveguide space. The multiple monitoring devices 40 are arranged periodically (e.g., at equal intervals) along the X direction. Even in such an arrangement mode of the eighth embodiment, the devices can be arranged while maintaining a low profile, as in the first embodiment described above.

[0217] Ninth embodiment The ninth embodiment will be described with reference to Fig. 28. As shown in Fig. 28, the monitoring devices 40 may be arranged along the X-direction side surfaces of the battery modules 20. The detection lines L are arranged along the upper surface of each battery module 20, but extend to the X-direction side surfaces via the Y-direction side surfaces of each battery module 20 in an L-shape, and are further connected along the Y direction to the monitoring device 40 on the X-direction side surface.

[0218] As in the above-described embodiments, the control device 50 is wirelessly connected to the multiple monitoring devices 40. Even in such an arrangement of the ninth embodiment, it is possible to configure a low profile, as in the above-described first embodiment. According to this embodiment, since it is not necessary to arrange the monitoring device 40 on the Y-direction side surface of the battery module 20, the Y-direction width of the housing 30 can be suppressed, and the housing 30 can be made smaller.

[0219] Moreover, since the monitoring device 40 does not need to be disposed on the upper surface of the battery module 20, the height of the housing 30 in the Z direction can be reduced, and the housing 30 can be made smaller. When emphasis is placed on the communication connection environment between the control device 50 and the multiple monitoring devices 40, it is preferable to provide the space S1 or S2 shown in the above embodiment at the end of the housing 30 in the Y direction or the upper end in the Z direction.

[0220] Tenth embodiment In the above embodiment, the battery monitoring system 1 is mounted on the vehicle 10, but the present invention is not limited to a system mounted on the vehicle 10. It may be applied to a stationary battery monitoring system 1 that is installed outdoors or indoors. For example, the battery monitoring system 1 may be configured in which a control device 50 incorporated in a battery exchange station, battery rack, etc., communicates wirelessly with the monitoring device 40.

[0221] Therefore, in the above embodiment, a form was described in which the communication speed is changed depending on the state and setting mode of the vehicle 10 and applied to communication within the vehicle 10, but the content of the present application is not limited to applications in which the vehicle 10 is installed, and can also be applied to a battery monitoring system 1 that uses a fixed battery rack.

[0222] A stationary battery rack is installed in a facility such as a residence or a factory and is connected to a household AC power source or a power supply unit of the facility. The power supply unit supplies power to the replaceable batteries of a vehicle 10 such as an electric vehicle 10 or an electric motorcycle, thereby charging the replaceable batteries.

[0223] Therefore, the technical configuration of the monitoring device 40 described in the above embodiment may be mounted on the replacement battery, and the technical configuration of the control device 50 may be mounted on the battery rack, and the method of the above embodiment may be applied. The communication method between the replacement battery and the battery rack may be wired communication or wireless communication. Therefore, the communication between the wireless communication unit 46 of the monitoring device 40 and the wireless communication unit 54 of the control device 50 is not limited to wireless communication and may be wired communication.

[0224] Furthermore, when the battery modules 20 are mounted on a stationary battery rack, the technical configuration of the monitoring device 40 described in the above embodiment may be mounted on the battery rack, and in this case, the technical configuration of the control device 50 (ECU) may be mounted inside a home or factory separately from the battery rack. With such a method, it is possible to obtain the same effects as those of the above embodiment.

[0225] A specific example is described below. A replaceable battery is attached to an electric vehicle 10 or the like and used as a driving power source. When a user removes the replaceable battery from the vehicle 10 and places it in a battery rack, charging of the replaceable battery begins. When a control device 50 is mounted on the battery rack and a monitoring device 40 is mounted on the replaceable battery, the control device 50 of the battery rack can monitor the battery status of the replaceable battery by communicating with the monitoring device 40 of the replaceable battery. If a replaceable battery is stored in a battery rack for a long period of time, the life of the replaceable battery will deteriorate. The battery rack can monitor the deterioration state of the replaceable battery and periodically grasp the battery status.

[0226] The replaceable battery is equipped with a battery pack 12, and a battery ID is assigned to a battery module 20 of the battery pack 12. By assigning a battery ID to the battery module 20, the location of the battery module 20 can be accurately identified, and maintenance can be performed smoothly in the event of a breakdown.

[0227] At this time, the aforementioned control device 50 (which may also be referred to as a BMU (Battery Management Unit)) functioning as the master may assign a battery ID to each battery module 20, or a slave other than the master (for example, the aforementioned monitoring device 40, which may be referred to as a provisioning device) may assign and assign a battery ID to each battery module 20.

[0228] At this time, either the master or the slave detects whether the battery module 20 has been replaced by detecting the contact with the battery module 20 of the battery pack 12 of the replaceable battery. After detecting the battery replacement, the fact may be notified to an external device (not shown) such as an external server, displayed on another display device (not shown), or an alarm may be sounded. This makes it possible to detect abnormalities such as theft.

[0229] (Other embodiments) The present invention is not limited to the above-described embodiment, and the following modifications and extensions are possible. In the above embodiment, the control device 50 generally acts as the master and the monitoring device 40 acts as the slave, but the opposite may be applied, in which the monitoring device 40 acts as the master and the control device 50 acts as the slave. That is, the master-slave relationship between the control device 50 and the monitoring device 40 is not limited to the above embodiment. The control device 50 may be the slave and the monitoring device 40 may be the master.

[0230] The start-up information for starting the vehicle 10 is not limited to the ignition switch ON information. For example, the start-up information for the vehicle 10 may be information on unlocking the driver's seat, information on the driver's seat being seated, information on unlocking the key switch, etc., other than the ignition switch ON information, or the start-up may be detected by combining these pieces of information.

[0231] In the above 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 the control device 50 at the center, and packet communication is possible. However, the network topology between the control devices 50 and the monitoring devices 40 is not limited to this example.

[0232] The control device 50 and the monitoring device 40 may form a mesh network. Also, the network may be configured by mixing at least two or more of a star-connected network, a mesh network, and a daisy-chain network. In this network configuration, a plurality of monitoring devices 40 are grouped and wired to form one network, and the grouped plurality of monitoring devices 40 function as one device. In this case, the mesh network is configured by a topology in which the control device 50 and the plurality of groups of monitoring devices 40 form a network. This network configuration may be applied.

[0233] The control device 50 and the monitoring device 40 may be connected to a daisy chain network. A network may be configured by mixing at least two of a star network, a mesh network, and a daisy chain network. Although a wireless connection network is exemplified for the control device 50 and the monitoring device 40, a wired connection network may also be mixed. In this way, the network topology of the control device 50 and the monitoring device 40 is not particularly limited.

[0234] For example, the wireless communication unit 46 may be configured as hardware with its functions separated into a wireless transmission unit and a wireless reception unit. A configuration may be applied in which the monitoring device 40 does not include the microcomputer 45. That is, the wireless communication unit 46 may be configured to be composed only of a wireless IC and to communicate with the battery monitoring unit 44. The sensing control by the battery monitoring unit 44 and the schedule control of the self-diagnosis may be executed by the main microcomputer 53 of the control device 50.

[0235] In the above example, the main microcomputer 53 of 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, and calculates the SOH based on the estimated internal resistance and open circuit voltage. However, the estimation of the internal resistance, the estimation of the open circuit voltage, and the calculation of the SOH are not limited to this example. For example, some or all of the processes of estimating the internal resistance, estimating the open circuit voltage, and calculating the SOH may be performed inside the monitoring device 40, for example, by the wireless communication unit 46.

[0236] Although an example has been shown in which the monitoring device 40 acquires the battery-related information based on an acquisition request from the control device 50, the present invention is not limited to this. The monitoring device 40 may autonomously acquire the battery-related information and transmit the held battery-related information to the control device 50 based on a transmission request from the control device 50.

[0237] In the above embodiment, an example has been shown in which a plurality of monitoring devices 40 are wirelessly networked in a star shape with the control device 50 at the center. However, the network topology between the control device 50 and the monitoring devices 40 is not limited to this example. A wired connection network may also be mixed in the network. In this way, the network topology between the control device 50 and the monitoring devices 40 is not particularly limited.

[0238] The arrangement and number of the battery modules 20 and the battery cells 22 that constitute the assembled battery 12 are not limited to the above example. The arrangement of the monitoring device 40 and / or the control device 50 within the battery pack 11 is not limited to the above example.

[0239] Although an example in which one control device 50 is provided in the battery pack 11 has been shown, the present invention is not limited to this, and a plurality of control devices 50 may be provided. In other words, it is sufficient that the battery pack 11 is provided with a plurality of monitoring devices 40 and one or more control devices 50. The battery pack 11 may be provided with a plurality of wireless communication systems established between the control device 50 and the plurality of monitoring devices 40.

[0240] Although the monitoring device 40 has one battery monitoring unit 44 in the above embodiment, the present invention is not limited to this and may have a plurality of battery monitoring units 44 (sensor ICs). The wireless communication unit 46 may not include the microcomputer 45. In this case, the main microcomputer 53 may implement part of the functions of the wireless communication unit 46.

[0241] Although an example in which one monitoring device 40 is provided for every one or two battery modules 20 has been shown, the present invention is not limited to this. For example, one monitoring device 40 may be provided for three or more battery modules 20. For example, two or more monitoring devices 40 may be provided for one battery module 20.

[0242] In the above embodiment, one battery module 20 is considered as one group, and a plurality of such groups are arranged side by side and stored in the battery pack 11, but the present invention is not limited to this. One group does not have to be provided in units of one battery module 20, one battery stack, or one battery block. Battery cells 22 obtained by dividing one battery module 20 may be regarded as one group. In addition, for example, the battery cells 22 may be packed and stored in the vehicle 10 without modules in a cell-to-pack or cell-to-chassis form. In such a case, a collection of one or more battery cells 22 may be regarded as a group.

[0243] The monitoring device 40 may be configured across multiple groups of battery cells 22. In this case, multiple battery monitoring units 44 may be provided for each group. The monitoring device 40 may be provided for each group, and in this case, the battery monitoring units 44 may be configured to monitor the battery cells 22 for each group. The number of battery cells 22 included in each group does not have to be the same, and may be different for each group.

[0244] The control device 50, monitoring device 40, host ECU 16 and the methods thereof described in the present disclosure may be implemented by a special-purpose computer provided by configuring a processor and memory programmed to execute one or more functions embodied in a computer program. Alternatively, the control device 50, monitoring device 40, host ECU 16 and the methods thereof described in the present disclosure may be implemented by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits.

[0245] Alternatively, the control device 50, the monitoring device 40, the host ECU 16, and the methods thereof described in the present disclosure may be implemented by one or more dedicated computers configured by combining a processor and memory programmed to execute one or more functions with a processor configured by one or more hardware logic circuits. Also, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions to be executed by the computer.

[0246] In other words, the means and / or functions provided by a processor, etc., can be provided by software recorded in a physical memory device and a computer that executes the software, by software alone, by hardware alone, or by a combination of these. For example, some or all of the functions of a processor may be realized as hardware. A form in which a certain function is realized as hardware includes a form in which it is realized using one or more ICs, etc.

[0247] The processor may be realized using a CPU, an MPU, a GPU, or a DFP. DFP stands for Data Flow Processor. The processor may be realized by combining multiple types of arithmetic processing devices such as a CPU, an MPU, and a GPU. The processor may be realized as a system on chip (SoC). SoC is an abbreviation for System on Chip.

[0248] Furthermore, the parts that execute the various processes described in the above-mentioned embodiments may be realized using hardware such as FPGA or ASIC. The various programs may be stored in a non-transient physical recording medium. As a storage medium for the programs, various storage media such as HDD, SSD, flash memory, and SD card can be adopted. FPGA stands for Field Programmable Gate Array. HDD stands for Hard disk Drive. SSD stands for Solid State Drive. SD stands for Secure Digital.

[0249] In addition to the claims, the present disclosure also includes the following inventions. [1] A monitoring device that monitors the state of a battery and transmits the battery information to a control device via wireless communication, the monitoring device having a monitoring device side communication unit (46) that executes a connection process (S100) with the control device side communication unit and communicates the battery information, the monitoring device side communication unit setting a communication speed when executing a predetermined connection process of at least a part of the connection process with the control device side communication unit slower than the communication speed when transmitting the battery information to the control device side communication unit.

[0250] [2] The monitoring device of [1], wherein the monitoring device communication unit changes a communication speed from the monitoring device communication unit to the control device communication unit after a connection request (S13) received during the connection process.

[0251] [3] A monitoring device according to [1] or [2], comprising a battery monitoring unit (44) having a startup circuit (44b) that receives power supply and starts up the monitoring device main body, wherein the startup circuit of the battery monitoring unit receives power supply only from a wired power supply unit at startup.

[0252] [4] A monitoring device according to any one of [1] to [3], wherein when executing the connection process with the monitoring device side communication unit, the monitoring device side communication unit switches the communication speed from a predetermined speed to a high speed before starting up the battery monitoring unit.

[0253] [5] The control device side communication unit is configured to assign a time slot for receiving battery information to each of a plurality of monitoring devices, and the monitoring device side communication unit assigns the battery information to the time slot and transmits the battery information by communicating at a speed faster than the communication speed used for the connection processing. Any of the monitoring devices [1] to [4].

[0254] [6] Any of the monitoring devices [1] to [5], wherein when the monitoring device communication unit transmits an advance detection request (S21) to announce its own presence in the specified connection process executed asynchronously with the control device, the monitoring device transmits the advance detection request at a communication speed slower than the communication speed at which the signal necessary for the connection process is received after transmitting the advance detection request and synchronizing.

[0255] [7] The monitoring device of any one of [1] to [5], wherein when the monitoring device communication unit transmits a detection request (22a) to establish a connection in the specified connection process executed asynchronously with the control device, the communication unit transmits the detection request at a communication speed slower than the communication speed at which a signal required for the connection process is transmitted after transmitting the detection request and synchronizing.

[0256] [8] The monitoring device of any one of [1] to [7], wherein the monitoring device side communication unit switches to communication of the battery information upon completing the connection process and continues the periodic communication process (S200).

[0257] [9] The monitoring device of any one of [1] to [8], wherein the monitoring device side communication unit divides the battery information and transmits the divided battery information to the control device side communication unit while performing the connection process.

[0258]

[10] The monitoring device of any one of [1] to [9], wherein the monitoring device side communication unit sets a communication speed when including battery information in a packet and sending it to the control device side communication unit while performing the connection process with the control device side communication unit to be the same as the communication speed when transmitting the battery information to the control device side communication unit after completing the connection process.

[0259]

[11] A monitoring device according to any one of [1] to

[10] , wherein the communication speed at which the monitoring device communication unit communicates with the control device communication unit when the vehicle is in a stopped state is slower than the communication speed when the vehicle is in an started state.

[0260]

[12] A monitoring device according to any one of [1] to

[11] , configured to execute an equalization process for equalizing cell voltages among a plurality of battery cells at a predetermined timing when the vehicle is stopped, wherein a communication speed at which the monitoring device side communication unit communicates with the control device side communication unit while executing the equalization process when the vehicle is stopped is faster than a speed at which an advance detection request (S21) is sent as the predetermined connection process.

[0261]

[13] A monitoring device according to any one of [1] to

[12] , wherein when the monitoring device side communication unit is communicating the cell voltage of a battery to the control device side communication unit as battery information, if the cell voltage from its own monitoring device side communication unit is not received by the control device side communication unit for a certain period of time, the monitoring device side communication unit executes the connection process with the control device side communication unit at a communication speed slower than the communication speed of the battery information communicated by the control device side communication unit with a monitoring device side communication unit other than its own monitoring device side communication unit.

[0262]

[14] The monitoring device side communication unit communicates with the control device side communication unit by switching between a first channel group consisting of one or more channels of a non-battery information communication frequency band for communicating non-battery information and a second channel group consisting of one or more channels of a battery information communication frequency band for communicating battery information, and the monitoring device side communication unit communicates at a slower speed in the first channel group of the non-battery information communication frequency band than in the second channel group of the battery information communication frequency band, and when the battery information from the monitoring device side communication unit of its own monitoring device is not received by the control device side communication unit while communicating the battery information with the control device side communication unit using the second channel group of the battery information communication frequency band, the monitoring device side communication unit switches from the second channel group of the battery information communication frequency band to the first channel group of the non-battery information communication frequency band, and executes the connection process with the control device side communication unit.

[0263]

[15] The monitoring device side communication unit communicates with the control device side communication unit by switching between a second channel group consisting of one or more channels in a battery information communication frequency band for transmitting battery information to the control device side communication unit, and a first channel group consisting of one or more channels in a non-battery information communication frequency band, which is a band for transmitting an advance detection request (S21) that makes the monitoring device known and announces its presence, and transmits the advance detection request in the non-battery information communication frequency band before transmitting a continued connection request (S23, S28) for continued connection in the battery information communication frequency band. Any of the monitoring devices [1] to

[14] .

[0264]

[16] The monitoring device of any one of [1] to

[15] , wherein the monitoring device side communication unit transmits the continuous connection request at a higher speed than the advance detection request.

[0265]

[17] A control device that receives battery information via wireless communication from one or more monitoring devices that monitor the state of a battery and converts the battery information into battery information, and is equipped with a control device side communication unit (54) that performs connection processing with the monitoring device side communication unit and communicates the battery information to the monitoring device side communication unit, and the control device side communication unit sets a communication speed when performing a predetermined connection processing of at least a part of the connection processing with the monitoring device lower than the communication speed when receiving the battery information.

[0266]

[18] The control device according to claim 17, wherein the control device side communication unit changes a communication speed for transmitting the battery information from the monitoring device side communication unit to the control device side communication unit after a connection request (S13) transmitted during the connection process.

[0267]

[19] The control device according to

[17] or

[18] , wherein the control device side communication unit is configured to assign a time slot for receiving the battery information to each of a plurality of monitoring devices.

[0268]

[20] The control device according to any one of

[17] to

[19] , wherein when the control device side communication unit receives an advance detection request (S21) sent from the monitoring device to announce its own presence during the specified connection process executed asynchronously with the monitoring device side communication unit, the control device side communication unit receives the advance detection request from the monitoring device side communication unit at a communication speed slower than the communication speed at which the control device receives a signal necessary for the connection process after receiving the advance detection request from the monitoring device side communication unit and synchronizing.

[0269] [twenty one] The control device according to any one of

[17] to

[20] , wherein when the control device side communication unit receives a detection request (S22a) transmitted from the monitoring device to establish a connection in the specified connection process executed asynchronously with the monitoring device side communication unit, the control device side communication unit receives the detection request from the monitoring device side communication unit at a communication speed slower than the communication speed at which a signal necessary for the connection process is received after receiving and synchronizing with the detection request from the monitoring device side communication unit.

[0270] [twenty two] The control device side communication unit is configured to communicate individually with the monitoring device side communication units of the multiple monitoring devices, and the communication speed from the monitoring device side communication unit to the control device side communication unit is individually switchable. Any of the control devices

[17] to

[21] .

[0271] [twenty three] The control device side communication unit switches to communication of the battery information from the monitoring device that has completed the connection process, and continues communication.

[0272] [twenty four] A control device according to any one of

[17] to

[23] , in which the communication speed from the control device side communication unit to the multiple monitoring devices is not switched while the communication speed is switched from the other monitoring devices to the control device side communication unit.

[0273] [twenty five] The control device according to any one of

[17] to

[24] , wherein the control device side communication unit divides the battery information and instructs the monitoring device to transmit the divided battery information during the connection process.

[0274]

[26] The control device according to

[25] , wherein the control device side communication unit is configured so that the communication speed from the monitoring device when the vehicle is stopped is slower than the communication speed when the vehicle is started.

[0275]

[27] The control device according to any one of

[17] to

[26] , wherein the control device side communication unit receives communication information from the monitoring device side communication unit at a speed faster than the communication speed at which a predicted detection request (S21) is received from the monitoring device side communication unit as the specified connection process when the vehicle is stopped.

[0276]

[28] A control device according to any one of

[17] to

[27] , wherein, when the cell voltage of the battery is being received as the battery information from the monitoring device side communication unit, and the cell voltage is not received from the monitoring device side communication unit for a certain period of time, the control device side communication unit processes the connection with the monitoring device side communication unit at a communication speed for the battery information slower than the communication speed between the control device side communication unit and a monitoring device side communication unit other than the monitoring device that did not receive the cell voltage.

[0277]

[29] A battery information communication system comprising one or more monitoring devices (40) that monitor the state of a battery (12) and transmit the state as battery information via wireless communication, and a control device (50) that receives the battery information from the monitoring devices via wireless communication, wherein the monitoring devices have a monitoring device side communication unit (46) that executes a connection process (S100) with a control device side communication unit and communicates the battery information, and the control device has a control device side communication unit (54) that executes the connection process with the monitoring device side communication unit and communicates the battery information, and the control device side communication unit and the monitoring device side communication unit have a communication speed when executing a predetermined connection process at least as part of the connection process with each other that is slower than the communication speed when communicating the battery information from the monitoring device side communication unit to the control device side communication unit.

[0278]

[30] A battery information communication program to be executed by one or more monitoring devices which monitor the status of a battery and transmit the battery information to a control device via wireless communication, the program executing a communication procedure in which a connection process (S100) is executed between a monitoring device side communication unit and a control device side communication unit to transmit the battery information, and in the communication procedure, the communication speed when executing a specified connection process of at least a part of the connection process is slower than the communication speed at which the battery information is transmitted from the monitoring device side communication unit to the control device side communication unit.

[0279]

[31] A battery information communication method using one or more monitoring devices that monitor the status of a battery and transmit the battery information to a control device via wireless communication, comprising a transmission process in which a monitoring device side communication unit executes a connection process (S100) with a control device side communication unit to transmit the battery information, and in the transmission process, a communication speed when executing a predetermined connection process for at least a part of the connection process is communicated at a slower communication speed than the communication speed at which the battery information is transmitted from the monitoring device side communication unit to the control device side communication unit.

[0280] Although the present disclosure has been described based on the above-mentioned embodiment, it is understood that the present disclosure is not limited to the embodiment or the structure described in the embodiment. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, and other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and concept of the present disclosure. [Explanation of symbols]

[0281] In the drawings, 12 indicates a battery pack (battery), 20 indicates a battery module (battery), 22 indicates a battery cell (battery), 40 indicates a monitoring device (monitoring device main body), 46 indicates a wireless communication unit (control device side communication unit), 50 indicates a control device (control device main body), 54 indicates a wireless communication unit (control device side communication unit), S100 indicates a connection process, and S200 indicates a periodic communication process.

Claims

1. A monitoring device that monitors the state of a battery and transmits the result as battery information to a control device via wireless communication, a monitoring device side communication unit (46) that executes a connection process (S100) with the control device side communication unit and communicates the battery information; A monitoring device in which the communication speed when executing a specified connection process of at least a part of the connection process with the control device side communication unit is slower than the communication speed when transmitting the battery information to the control device side communication unit.

2. 2. The monitoring device according to claim 1, wherein the monitoring device communication unit changes a communication speed from the monitoring device communication unit to the control device communication unit after a connection request (S13) received during the connection process.

3. a battery monitoring unit (44) having a start-up circuit (44b) for starting up a monitoring device main body upon receiving power supply; 2. The monitoring device according to claim 1, wherein a start-up circuit of the battery monitoring unit receives power only from a power supply unit connected by wire at the time of start-up.

4. 4. The monitoring device according to claim 3, wherein the monitoring device communication section switches the communication speed from a predetermined speed to a high speed before the battery monitoring section is started up when the connection process is performed with the control device communication section.

5. the control device side communication unit is configured to allocate a time slot for receiving battery information to each of the plurality of monitoring devices; 2. The monitoring device according to claim 1, wherein the monitoring device communication section assigns battery information to the time slot and transmits the battery information by communicating at a speed higher than a communication speed used for the connection process.

6. When the monitoring device communication unit transmits a pre-announced detection request (S21) for announcing its own presence in the predetermined connection process executed asynchronously with the control device communication unit, 2. The monitoring device according to claim 1, wherein after transmitting the advance detection request and synchronizing, the signal required for the connection process is transmitted at a communication speed slower than the communication speed at which the signal is received.

7. When the monitoring device communication unit transmits a detection request (22a) to establish a connection in the predetermined connection process executed asynchronously with the control device communication unit, 2. The monitoring device according to claim 1, wherein after transmitting the detection request and synchronizing, the signal required for the connection process is transmitted at a communication speed slower than the communication speed.

8. The monitoring device according to claim 1 , wherein the monitoring device side communication unit switches to communication of the battery information and continues the periodic communication process (S 200 ) upon completing the connection process.

9. The monitoring device according to claim 1 , wherein the monitoring device communication section divides the battery information and transmits the divided battery information to the control device communication section while the connection process is being performed.

10. The monitoring device described in claim 1, wherein the monitoring device side communication unit includes battery information in a packet and sends it to the control device side communication unit while executing the connection process with the control device side communication unit, and sets the communication speed to be the same as the communication speed when sending the battery information to the control device side communication unit after completing the connection process.

11. 11. The monitoring device according to claim 10, wherein a communication speed at which the monitoring device communication section communicates with the control device communication section when the vehicle is stopped is slower than a communication speed when the vehicle is running.

12. The vehicle is configured to execute an equalization process for equalizing cell voltages among a plurality of battery cells at a predetermined timing when the vehicle is stopped, A monitoring device as described in claim 1, wherein the communication speed at which the monitoring device side communication unit communicates with the control device side communication unit while performing the equalization process when the vehicle is stopped is faster than the speed at which an advance detection request (S21) is sent as the specified connection process.

13. When the monitoring device communication unit is in a state where it is communicating the cell voltage of the battery to the control device communication unit as battery information, When the cell voltage is not received by the control device communication unit from its own monitoring device communication unit for a certain period of time, The monitoring device of claim 1, wherein the monitoring device side communication unit performs the connection processing with the control device side communication unit at a speed slower than the communication speed at which the control device side communication unit communicates the battery information with monitoring device side communication units other than its own monitoring device side communication unit.

14. the monitoring device communication unit communicates with the control device communication unit by switching between a first channel group consisting of one or more channels in a non-battery information communication frequency band for communicating non-battery information and a second channel group consisting of one or more channels in a battery information communication frequency band for communicating battery information; the monitoring device communication unit communicates at a lower speed on a first group of channels in the non-battery information communication frequency band than on a second group of channels in the battery information communication frequency band; When the battery information is communicated between the control device side communication unit and the control device side communication unit using the second channel group of the battery information communication frequency band, if the battery information from the monitoring device side communication unit of the monitoring device itself is not received by the control device side communication unit, The monitoring device according to claim 1 , wherein the monitoring device side communication unit switches from a second channel group of the battery information communication frequency band to a first channel group of the non-battery information communication frequency band to perform the connection processing with the control device side communication unit.

15. the monitoring device side communication unit communicates with the control device side communication unit by switching between a second channel group consisting of one or more channels in a battery information communication frequency band for transmitting battery information to the control device side communication unit and a first channel group consisting of one or more channels in a non-battery information communication frequency band, which is a band for transmitting a pre-announced detection request (S21) for publicizing the presence of the monitoring device, The monitoring device according to claim 1 , further comprising: a detection request transmitting section configured to transmit the advance notice detection request in the non-battery information communication frequency band before transmitting a continuous connection request (S23, S28) for maintaining a continuous connection in the battery information communication frequency band.

16. The monitoring device according to claim 15 , wherein the monitoring device side communication unit transmits the continuous connection request at a higher speed than the advance notice detection request.

17. A control device that receives battery information from one or more monitoring devices that monitor a state of a battery and obtain the battery information by wireless communication, a control device side communication unit (54) that performs connection processing with a monitoring device side communication unit and communicates the battery information to the monitoring device side communication unit; The control device side communication unit sets the communication speed when executing a predetermined connection process of at least a part of the connection process with the monitoring device to be slower than the communication speed when receiving the battery information.

18. The control device according to claim 17 , wherein the control device side communication unit changes the communication speed at which the battery information is transmitted from the monitoring device side communication unit to the control device side communication unit after a connection request (S13) transmitted during the connection process.

19. The control device according to claim 17, wherein the control device side communication section is configured to allocate a time slot for receiving the battery information to each of a plurality of monitoring devices.

20. When the control device side communication unit receives a pre-announced detection request (S21) for announcing the presence of the control device side communication unit, the pre-announced detection request is transmitted from the monitoring device side communication unit in the predetermined connection process executed asynchronously with the monitoring device side communication unit, The control device according to claim 17, wherein the control device receives the advance detection request from the monitoring device side communication section and synchronizes with the request, and then receives the signal required for the connection process at a communication speed slower than the communication speed at which the signal is received.

21. When the control device side communication unit receives a detection request (S22a) transmitted from the monitoring device side communication unit in order to establish a connection in the predetermined connection process executed asynchronously with the monitoring device side communication unit, The control device according to claim 17, wherein the control device receives the detection request from the monitoring device side communication section and, after synchronization, receives the signal required for the connection process at a communication speed slower than the communication speed at which the signal is received.

22. The control device according to claim 17, wherein the control device side communication unit is configured to communicate individually with the monitoring device side communication units of the plurality of monitoring devices, and is configured to be able to individually switch the communication speed from the monitoring device side communication unit to the control device side communication unit.

23. The control device according to claim 17 , wherein the control device side communication unit switches to communication of the battery information from the monitoring device that has completed the connection process, and continues the communication.

24. 18. The control device according to claim 17, wherein the communication speed from the control device side communication section to the plurality of monitoring devices is not switched while the communication speed is switched from the other monitoring devices to the control device side communication section.

25. The control device according to claim 17 , wherein the control device side communication unit divides the battery information and instructs the monitoring device to transmit the divided battery information during the connection process.

26. 26. The control device according to claim 25, wherein the control device side communication section sets a communication speed from the monitoring device when the vehicle is in a stopped state to be slower than a communication speed when the vehicle is in an activated state.

27. The control device according to claim 17, wherein the control device side communication unit receives information from the monitoring device side communication unit at a communication speed faster than the communication speed at which the control device side communication unit receives an advance detection request (S21) as the specified connection processing from the monitoring device side communication unit while the vehicle is stopped and the cell voltage of the battery is being equalized.

28. A state in which a cell voltage of the battery is received as the battery information from the monitoring device side communication unit, When the cell voltage is not received from the monitoring device communication unit for a certain period of time, The control device according to claim 17, wherein the control device side communication unit performs connection processing with the monitoring device side communication unit at a communication speed of the battery information slower than the communication speed between the control device side communication unit and the monitoring device side communication unit other than the monitoring device that did not receive the cell voltage.

29. one or more monitoring devices (40) for monitoring the state of the battery (12) and transmitting the state as battery information by wireless communication; a control device (50) that receives the battery information from the monitoring device via wireless communication; the monitoring device includes a monitoring device side communication unit (46) that executes a connection process (S100) with a control device side communication unit and communicates the battery information, and the control device includes a control device side communication unit (54) that executes the connection process with the monitoring device side communication unit and communicates the battery information, A battery information communication system in which the control device side communication unit and the monitoring device side communication unit each perform a specified connection process at least a part of the connection process at a communication speed slower than the communication speed when communicating the battery information from the monitoring device side communication unit to the control device side communication unit.

30. A battery information communication program to be executed by one or more monitoring devices that monitor a state of a battery and transmit the state of the battery to a control device via wireless communication, A communication procedure is executed in which a connection process (S100) is executed between the monitoring device communication unit and the control device communication unit to transmit the battery information; A battery information communication program in which the communication speed when executing at least a part of a specified connection process of the connection process is slower than the communication speed at which the battery information is transmitted from the monitoring device side communication unit to the control device side communication unit in the communication procedure.

31. A battery information communication method using one or more monitoring devices that monitor a battery state and transmit the battery information to a control device via wireless communication, comprising: A transmission step of executing a connection process (S100) between the monitoring device communication unit and the control device communication unit to transmit the battery information; A battery information communication method in which, during the transmission process, the communication speed when executing a specified connection process of at least a part of the connection process is communicated at a slower speed than the communication speed at which the battery information is transmitted from the monitoring device side communication unit to the control device side communication unit.

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