Transmission device and reception device

Abstract

The present disclosure provides a transmission device and a reception device capable of appropriately transmitting and receiving data while suppressing insufficient identifiers. A transmission device that divides transmission data into a plurality of frames, stores the frames, and transmits the transmission frames, the transmission device being provided with a frame generation unit that assigns the same identifier to the plurality of frames, and that divides a data field different from the identifier storage unit into a first region and a second region in the plurality of frames, identification information, which is information for identifying a plurality of frames from each other, is stored in a first region, and transmission data is stored in a second region.

Description

Technical Field

[0001] The present disclosure relates to a transmission device and a reception device. Background Art

[0002] In a power storage device, communication using the CAN (Controller Area Network) protocol (hereinafter appropriately referred to as "CAN communication") is used between a battery module and a management device that manages a plurality of battery modules. For example, Patent Document 1 discloses a case where CAN-based communication is performed between a battery module mounted on a moving body such as an electric vehicle and an ECU (Electric Control Unit) that controls various machines mounted on the moving body.

[0003] In CAN communication, for each data frame that is a unit of data transmission and reception, an inherent identifier called an ID (IDentifier) for identifying a transmission node as a transmission source is assigned, and transmission data is stored in a data field that is a data storage area in the data frame. Further, a transmission node such as a battery module transmits a data frame storing transmission data to all nodes including a reception node as a transmission destination. On the other hand, a reception node such as a management device receives a data frame transmitted from the transmission node based on the ID assigned to the transmitted data frame, and acquires the transmission data stored in the data field.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: WO 2018 / 147046 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] However, in CAN communication, usually only one data frame can be transmitted in one transmission process. That is, in CAN communication, the number of frames and the data size that can be processed in one transmission and reception process are also fixed. Therefore, when transmitting a frame having a size larger than the size of the transmission field, it is necessary to perform multiple transmission processes by using a plurality of frames assigned with different IDs to transmit data.

[0009] However, since the number of IDs that can be assigned to data frames is limited, the number of frames that can be transmitted and received between devices and the data size are also limited. Therefore, there is a problem that when transmitting data of data frames exceeding the maximum number of IDs, the IDs may be insufficient and data may not be transmitted appropriately.

[0010] An object of the present disclosure is to provide a transmitting device and a receiving device that can appropriately transmit and receive data while suppressing a shortage of identifiers.

[0011] Solution to the problem

[0012] The transmitting device of the present disclosure is a transmitting device that divides transmission data into a plurality of frames, stores them, and transmits the transmission frames.

[0013] The transmitting device includes a frame generation unit that assigns the same identifier to the plurality of frames. Among the plurality of frames, a data field different from the storage unit of the identifier is divided into a first area and a second area, and identification information is stored in the first area, while the transmission data is stored in the second area. The identification information is information for distinguishing the plurality of frames from each other.

[0014] In addition, the receiving device of the present disclosure is a receiving device that receives transmission data divided into a plurality of frames and stored.

[0015] The receiving device includes a data combining unit that, for the plurality of frames assigned with the same identifier, refers to the data field divided into the first area and the second area, and combines the transmission data stored in the second area based on the identification information about the transmission data stored in the first area.

[0016] Transmission effect

[0017] According to the present disclosure, it is possible to appropriately transmit and receive data while suppressing a shortage of identifiers. Brief Description of the Drawings

[0018] Figure 1 It is a schematic diagram showing an example of the structure of the power storage device according to the present embodiment.

[0019] Figure 2 It shows Figure 1 A functional block diagram showing an example of the structure of the BMU of

[0020] Figure 3 It is a schematic diagram for explaining a data frame in the standard format in CAN communication.

[0021] Figure 4 It is a schematic diagram for explaining information stored in a data field.

[0022] Figure 5 It is a schematic diagram showing an example of information included in transmission data transmitted and received between the BMU and the BMS.

[0023] Figure 6 It is a schematic diagram for explaining data stored in a conventional data field.

[0024] Figure 7 It is a schematic diagram for explaining the data stored in the data fields of the present embodiment. Detailed Embodiment

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. The present disclosure is not limited to the following embodiments, and various modifications can be made without departing from the gist of the present disclosure. In addition, the present disclosure includes all combinations of structures that can be combined among the structures shown in the following respective embodiments. In addition, in each figure, parts denoted by the same reference numerals are the same parts or parts equivalent thereto, which is the same throughout the specification.

[0026] [Structure of Power Storage Device 1]

[0027] Figure 1 It is a schematic diagram showing an example of the structure of the power storage device 1 of the present embodiment. The power storage device 1 stores the power supplied from an external power source (not shown) and supplies the stored power to a power supply object (not shown). As Figure 1 shown, the power storage device 1 includes a plurality of battery modules 10 and a BMU (Battery Management Unit) 20. The battery modules 10 and the BMU 20 are connected to the bus 2.

[0028] (Battery Module 10)

[0029] The battery module 10 includes a secondary battery 11 and a BMS (Battery Management System) 12.

[0030] The secondary battery 11 is composed of one or more secondary battery cells. In the case of being composed of a plurality of secondary battery cells, the respective secondary battery cells are connected in series. The secondary battery 11 is, for example, a nickel-metal hydride secondary battery. It should be noted that the type of the secondary battery 11 is not limited to this example, and it may also be a secondary battery other than a nickel-metal hydride secondary battery such as a lithium-ion secondary battery. In addition, a plurality of secondary batteries 11 may be provided, and in this case, the plurality of secondary batteries 11 are, for example, connected in series.

[0031] The BMS 12 controls and monitors the secondary battery 11 in the battery module 10, etc. For example, the BMS 12 monitors the voltage and temperature of the secondary battery 11 based on the detection results of various sensors (not shown). In addition, the BMS 12 monitors and controls the cell balancing of the plurality of secondary battery cells based on the detection results.

[0032] Furthermore, the BMS 12 communicates with the BMU 20 via the bus 2 to exchange instruction information and battery information related to the secondary battery 11 or the battery module 10. The battery information is information related to the secondary battery such as the secondary battery 11 or the battery module 10. In addition, the instruction information is information including instructions for obtaining battery information related to the secondary battery 11 or the battery module 10 from the BMS 12 and the like.

[0033] In the present embodiment, CAN is used as the protocol for communication between the BMS 12 and the BMU 20. Details of the CAN communication using the CAN protocol will be described later.

[0034] The BMS 12 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. (all not shown). The CPU reads out a program corresponding to the processing content from the ROM, expands it in the RAM, and centrally controls the operation of the battery module 10 in cooperation with the expanded program.

[0035] (BMU20)

[0036] The BMU 20 controls and manages a plurality of battery modules 10. For example, the BMU 20 gives instructions such as power-on of each battery module 10 and fine adjustment of battery cell balance between the battery modules 10. In addition, the BMU 20 performs CAN communication with the BMS 12 of each battery module 10 via the bus 2 to exchange instruction information and battery information.

[0037] In addition, the BMU 20 monitors the current of each battery module 10 based on the detection results of sensors (not shown), for example, monitors overcharging and over-discharging of each battery module 10. Furthermore, the BMU 20 calculates the remaining amount of the secondary battery based on the battery information.

[0038] The BMU 20 includes a CPU, a ROM, a RAM, etc. (all not shown). The CPU reads out a program corresponding to the processing content from the ROM, expands it in the RAM, and centrally controls the operation of the power storage device 1 in cooperation with the expanded program.

[0039] Figure 2 is a Figure 1 functional block diagram showing an example of the structure of the BMU 20. Figure 2 A processing unit representing the function related to communication with the BMS 12 among the functions of the BMU 20. It should be noted that, regarding the BMS 12 of each battery module 10, the function related to communication is also the same as that of the BMU 20 and hasFigure 2 The structure shown. Here, BMU20 will be described as an example.

[0040] As Figure 2 shown, BMU20 has a data acquisition unit 21, a data segmentation unit 22, a frame generation unit 23, a transceiver unit 24, and a data combination unit 25.

[0041] The data acquisition unit 21 acquires data including indication information or battery information as transmission data. Here, the indication information or battery information contained in the transmission data is classified according to each data category, and the indication information or battery information regarding the same data category is included in the transmission data transmitted and received in one transceiver process.

[0042] The "data category" is a category that roughly classifies indication information and battery information. For example, in the indication information and battery information, there are "voltage-related information" related to voltage and "temperature-related information" related to temperature, etc., and this voltage-related information and temperature-related information correspond to the data category mentioned here. It should be noted that the details of the data categories contained in the indication information and battery information will be described later.

[0043] The data segmentation unit 22 segments the transmission data acquired by the data acquisition unit 21 into a specified size to generate segmented data. Specifically, the data segmentation unit 22 segments the transmission data, for example, into a size that can be stored in the data field of the data storage area of the data frame that is the unit of data transceiver. The segmented data is data obtained by segmenting the transmission data composed of the same data category according to each data content.

[0044] The "data content" is the content obtained by further subdividing the data classified according to each data category. For example, in the data classified as voltage-related information, there is information such as the current value and the maximum voltage of the cell voltage representing the secondary battery cells constituting the secondary battery 11, and this current value and maximum voltage of the cell voltage correspond to the data content mentioned here.

[0045] The frame generation unit 23 stores the identification information and the segmented data in the data field of the data frame. The identification information is information used to identify multiple data frames from each other. The details of the identification information will be described later. In addition, the frame generation unit 23 assigns the same identifier ID to multiple data frames corresponding to the number of segmented data to generate data frames.

[0046] The transceiver unit 24 performs a transmission process of sending a data frame from BMU20 to other devices connected to the bus 2, and also performs a reception process of receiving a data frame from other devices connected to the bus 2. For example, the transceiver unit 24 sends a data frame storing data including indication information for BMS12. In addition, the transceiver unit 24 receives a data frame storing data including battery information from BMS12.

[0047] When the data combining unit 25 receives a plurality of data frames from the BMS 12 via the transceiver unit 24, it combines the data contained in each data frame based on the identification information to restore the transmitted data sent from the BMS 12. It should be noted that when a plurality of data frames are received, it is not necessary to combine them to restore the transmitted data. In this case, the BMU 20 only needs to directly receive the divided data contained in each data frame.

[0048] [Regarding CAN communication]

[0049] In the present embodiment, the CAN communication used when exchanging data between the BMS 12 and the BMU 20 is described. As described above, in the present embodiment, when exchanging information between the BMS 12 and the BMU 20, CAN communication is used. Here, taking the standard format in CAN communication as an example, the data frame in the frame used for transceiver data in CAN communication is described.

[0050] (Structure of data frame)

[0051] Figure 3 is a schematic diagram for explaining the data frame of the standard format in CAN communication. As Figure 3 shown, the data frame in CAN communication includes regions such as SOF (Start Of Frame, start of the frame), ID, RTR (Remote Transmission Request), control field, data field, CRC (Cyclic Redundancy Check) sequence, CRC delimiter, ACK (ACKnowledgement) slot, ACK delimiter, and EOF (EndOf Frame, end of the frame).

[0052] The "SOF" region is a 1-bit long region indicating the start of the data frame. The "ID" region is an 11-bit long region for identifying the content and source of the data. The ID is stored in the ID region as an identifier for identifying the data frame. The range of the ID is 2048 from "0x0" to "0x7FF". It should be noted that the "0x" at the beginning of the ID value indicates that the value is represented in hexadecimal. The "RTR" region is a 1-bit long region for identifying whether the frame is a data frame.

[0053] The "control field" area is a 6-bit long area and stores a 1-bit long IDE (Identifier Extension), a 1-bit long reserved bit r, and a 4-bit long data length code (DLC, Data Length Code). "IDE" is used to distinguish between the standard format and the extended format obtained by extending the ID. The "reserved bit r" is used to distinguish between CAN and "CAN FD (CAN with Flexible Data rate)". "DLC" represents the length (in bytes) of the data field following the control field. The setting range of DLC is from "0" to "8". Thus, data from 0 to 8 bytes can be stored in the data field in 1-byte units.

[0054] The "data field" area is an area for storing transmitted data with a length of 0 to 8 bytes. In the data field, data with the length set by DLC can be stored.

[0055] The "CRC sequence" area is a 15-bit long area used to determine whether the receiving end can correctly receive the data frame. Specifically, at the sending end and the receiving end, values are calculated based on the SOF, ID, control field, and data field, and the normality of the data frame is determined by comparing the values of both sides. The "CRC delimiter" area is a 1-bit long area indicating the end of the CRC sequence. The CRC sequence and the CRC delimiter are collectively referred to as the "CRC field" area.

[0056] The "ACK slot" area is a 1-bit long area used to determine whether the CRC field part has been successfully received. The "ACK delimiter" area is a 1-bit long area indicating the end of the ACK slot. The ACK slot and the ACK delimiter are collectively referred to as the "ACK field" area. The "EOF" area is a 7-bit long area indicating the end of the data frame.

[0057] Generally, in CAN communication using this standard format, one piece of information can be sent in one transmission process. At this time, since the maximum size of data that can be stored in the data field is 8 bytes, in order to send data exceeding 8 bytes, multiple data frames and IDs corresponding to each data frame are required.

[0058] On the other hand, in the standard format of CAN communication, since the range of ID is from "0x000" to "0x7FF", only 2048 IDs can be assigned to data frames. Therefore, when the size of the data to be sent increases and more data frames than the maximum number of IDs are needed to send the transmitted data, there will be a shortage of IDs and the data cannot be properly sent.

[0059] In this case, it is possible to consider changing the format to an extended format that significantly increases the number of assignable IDs, or changing the protocol to "CAN FD" that extends the size of the data that can be transmitted per frame to 64 bytes. However, it is difficult to change the format or protocol in an existing system because all devices related to CAN communication etc. need to be redesigned.

[0060] Therefore, in the present embodiment, it is possible to appropriately transmit and receive data within the range of the maximum ID number without changing the format or protocol. Specifically, in the present embodiment, the same ID is assigned to a plurality of data frames, and a number of data frames exceeding the maximum ID number are generated. In addition, in each data frame, identification information regarding the transmission data for mutually identifying a plurality of data frames to which the same ID is assigned is set.

[0061] (Data field)

[0062] Figure 4 is a schematic diagram for explaining the information stored in the data field. As Figure 4 shown, in the present embodiment, a first area and a second area are set in the data field of the data frame.

[0063] The first area is an area for storing identification information for mutually identifying a plurality of data frames, and is an area of the first 2 bytes at the beginning of the data field with a maximum of 8 bytes. In the first area, a serial number and a data type are stored as identification information.

[0064] The "serial number" is identification information stored in the first byte of the data field. The serial number is a number indicating the order of data frames to which the same ID is assigned in the case where the transmission data is divided into a plurality of divided data. That is, the serial number indicates the order of the transmission data stored separately in the second area of a plurality of data frames. For example, in the case where the transmission data is divided into 4 divided data, serial numbers from "1" to "4" are assigned to 4 data frames storing these divided data. And these serial numbers are stored in the first byte of the data field in the order of division of the transmission data.

[0065] The "data type" is identification information stored in the second byte of the data field. The data type is a number indicating the content of the data stored in the second area. For example, in the case where the divided data includes a plurality of data contents, different data type numbers are assigned to each data content and stored. More specifically, for example, in the case where the divided data includes data with different data contents such as the current value of the cell voltage and the maximum voltage, the data type "0" is assigned to the data representing the current value of the cell voltage, and the data type "1" is assigned to the data representing the maximum voltage.

[0066] The second area is a data storage area for storing transmitted data, which is the largest remaining 6-byte area in the data field except for the first area. The transmitted data is stored in the second array. Here, when the size of the transmitted data exceeds the size of the second area, the segmented data obtained by segmenting the transmitted data is stored in this second area.

[0067] It should be noted that the area for storing the serial number and data type is not limited to this example. For example, it may be that the data type is stored in the first byte of the data field and the serial number is stored in the second byte.

[0068] (Data transmission and reception)

[0069] Next, with reference to Figure 2 the operation when data is transmitted and received between the transmitting device and the receiving device will be described. Here, it is assumed that the BMS12 of the battery module 10 functions as the transmitting device and the BMU20 functions as the receiving device, and the case of transmitting battery information related to the battery module 10 from the BMS12 to the BMU20 will be described as an example.

[0070] When transmitting data from the BMS12 to the BMU20, first, the data acquisition unit 21 of the BMS12 acquires data including battery information as the transmitted data. Then, the data acquisition unit 21 provides the acquired data to the data segmentation unit 22 as the transmitted data.

[0071] After receiving the transmitted data from the data acquisition unit 21, the data segmentation unit 22 generates segmented data by segmenting the transmitted data when the size of the transmitted data exceeds the size of the data field in the data frame (maximum 8 bytes). Specifically, the data segmentation unit 22 segments the transmitted data composed of the same data category according to each data content. In addition, the data segmentation unit 22 segments the data so that the size of the segmented data is at most 6 bytes. Then, the data segmentation unit 22 supplies the information indicating the number of segments and the data content together with the segmented data to the frame generation unit 23.

[0072] Based on the information indicating the number of segments received from the data segmentation unit 22, the frame generation unit 23 sets the serial number. In addition, based on the information indicating the data content received from the data segmentation unit 22, the frame generation unit 23 sets the data type. Furthermore, the frame generation unit 23 stores the set serial number and data type in the first area of the data field in the plurality of data frames.

[0073] Next, the frame generation unit 23 stores the segmented data received from the data segmentation unit 22 in the second area of the data field in each data frame corresponding to the serial number and the data type. Then, the frame generation unit 23 assigns the same ID to the generated plurality of data frames and provides the plurality of data frames to the transceiver unit 24.

[0074] The transceiver unit 24 sequentially transmits, via the bus 2, multiple data frames received from the frame generation unit 23 and assigned with a common ID to the BMU 20. At this time, the transceiver unit 24 transmits the multiple data frames in the order of the serial numbers, for example. The transmission of the multiple data frames is not limited to this. For example, as long as the BMU 20 can reliably receive all the data frames assigned with the same ID, the transmission can be performed in any order.

[0075] It should be noted that when there are data frames with the same ID on the bus 2, errors may occur or reception leakage of the BMU 20 may occur. Therefore, in this embodiment, the transmission interval of the multiple data frames is set to an interval that the BMU 20 can reliably receive.

[0076] On the other hand, when the BMU 20 receives data from the BMS 12, the transceiver unit 25 of the BMU 20 receives, via the bus 2, multiple data frames assigned with the same ID from the BMS 12. In this case, since the same ID is assigned to the multiple received data frames, the transceiver unit 25 determines that the data is of the same data category and provides the multiple received data frames to the data combining unit 25.

[0077] The data combining unit 25 refers to the data fields in the multiple acquired data frames and combines the data stored in the second regions of the data fields in each data frame according to the identification information stored in the first region of the data field.

[0078] First, the data combining unit 25 extracts the serial number and data type from the multiple received data frames. Then, based on the extracted serial number and data type, the data combining unit 25 combines the split data stored in the data fields of the multiple data frames to obtain the transmission data. Specifically, the data combining unit 25 extracts the split data with the same data content based on the extracted data type. Then, the data combining unit 25 combines the split data in the order of the serial numbers corresponding to the respective extracted split data. Thus, the transmission data sent from the BMS 12 is restored.

[0079] In this way, in this embodiment, the same ID is assigned to the multiple data frames, the split data is stored in the data fields of each frame, and the serial number and data type are stored. Therefore, compared with the prior art, the number of IDs allocated when transmitting and receiving the transmission data can be reduced, and thus the ID shortage can be suppressed.

[0080] On the other hand, when the size of the transmission data acquired by the data acquisition unit 21 is 8 bytes or less, since the transmission data can be stored in the data field of one data frame, there is no need to split the data. In this case, the data splitting unit 22 provides the acquired data to the frame generation unit 23 without splitting.

[0081] In addition, the frame generation unit 23 does not set the sequence number and data type, and stores the transmission data in all areas of the data field of the data frame that are composed of the first area and the second area. Then, the frame generation unit 23 assigns an ID to the data frame and provides it to the transceiver unit 24.

[0082] It should be noted that, without being limited to this, even when the size of the transmission data is less than or equal to the size of the data field in the data frame, the sequence number and data type can be set, and the transmission data can be segmented. Specifically, for example, the data segmentation unit 22 segments the transmission data regardless of the size of the received transmission data so that the size of the segmented data is at most 6 bytes to generate segmented data. In addition, the frame generation unit 23 sets the sequence number based on the number of segments of the transmission data, and sets the data type based on the information indicating the data content.

[0083] Thus, since the processes of setting the sequence number and data type and segmenting the transmission data are performed regardless of the size of the transmission data, the structure of the device can be simplified.

[0084] <Embodiment>

[0085] Next, a specific example is given to explain the transmission data exchanged between the BMU 20 and the BMS 12. In this example, it is assumed that one BMU 20 and seven battery modules 10 are connected to the power storage device 1. In addition, it is assumed that the secondary battery 11 mounted on each battery module 10 is composed of twelve secondary battery cells connected in series.

[0086] First, the instruction information and battery information transmitted and received between the BMU 20 and the BMS 12 are explained. Figure 5 It is a schematic diagram showing an example of the information contained in the transmission data transmitted and received between the BMU 20 and the BMS 12. In Figure 5 "Data category" represents the category of the information contained in the transmission data. In the present embodiment, "ID" represents the value of the ID assigned to the data frame storing the information represented by each data category. Similar to the conventional CAN communication, "Number of IDs" represents the number of IDs required when an ID is assigned to each data frame. It should be noted that the numerical values at the lowermost row of the columns of "ID" and "Number of IDs" represent the total number of IDs required to transmit the information about all data categories.

[0087] As Figure 5 shown, in the instruction information and battery information, as data categories, it includes operation information, self-diagnosis information, voltage-related information, temperature-related information, battery cell balance information, manufacturing-related information, and error notification.

[0088] "Operation information" is information related to operations such as power-on of the battery module 10. In the operation information, "operation instruction", which is instruction information sent from the BMU 20 to the BMS 12, and "operation acquisition", which is battery information sent from the BMS 12 to the BMU 20, are included. One ID is required for each case of transmitting and receiving the "operation instruction" and for each case of transmitting and receiving the "operation acquisition".

[0089] "Self-diagnosis information" is information related to self-diagnosis of the state of the battery module 10 and the like. In the self-diagnosis information, "self-diagnosis / alert instruction", which is instruction information sent from the BMU 20 to the BMS 12, and "self-diagnosis / alert acquisition", which is battery information sent from the BMS 12 to the BMU 20, are included. One ID is required for each case of transmitting and receiving the "self-diagnosis / alert instruction" and for each case of transmitting and receiving the "self-diagnosis / alert acquisition".

[0090] "Voltage-related information" is information related to voltage such as the voltage value of the secondary battery 11 or the secondary battery cells constituting the secondary battery 11. In the voltage-related information, "voltage-related instruction", which is instruction information sent from the BMU 20 to the BMS 12, and "voltage-related acquisition", which is battery information sent from the BMS 12 to the BMU 20, are included. 77 IDs are required for each case of transmitting and receiving the "voltage-related instruction" and for each case of transmitting and receiving the "voltage-related acquisition".

[0091] "Temperature-related information" is information related to temperature such as the temperature of the secondary battery 11 or the secondary battery cells constituting the secondary battery 11. In the temperature-related information, "temperature-related instruction", which is instruction information sent from the BMU 20 to the BMS 12, and "temperature-related acquisition", which is battery information sent from the BMS 12 to the BMU 20, are included. 13 IDs are required for each case of transmitting and receiving the "temperature-related instruction" and for each case of transmitting and receiving the "temperature-related acquisition".

[0092] "Battery cell balance information" is information related to battery cell balance among a plurality of secondary battery cells constituting the secondary battery 11. In the battery cell balance information, "battery cell balance instruction" and "battery cell balance setting", which are instruction information sent from the BMU 20 to the BMS 12, and "battery cell balance acquisition" and "battery cell balance acceptance", which are battery information sent from the BMS 12 to the BMU 20, are included. One ID is required for each case of transmitting and receiving the "battery cell balance instruction" and for each case of transmitting and receiving the "battery cell balance acquisition". Additionally, 3 IDs are required for each case of transmitting and receiving the "battery cell balance setting" and for each case of transmitting and receiving the "battery cell balance acceptance".

[0093] "Manufacturing-related information" is information related to the battery module 10 and the secondary battery 11, as well as manufacturing-related information such as manufacturing numbers. The manufacturing-related information includes "manufacturing-related instruction" and "manufacturing-related setting" as instruction information sent from the BMU 20 to the BMS 12, and "manufacturing-related acquisition" and "manufacturing-related acceptance" as battery information sent from the BMS 12 to the BMU 20. In the case of transmitting and receiving "manufacturing-related instruction", in the case of transmitting and receiving "manufacturing-related acquisition", in the case of transmitting and receiving "manufacturing-related setting", and in the case of transmitting and receiving "manufacturing-related acceptance", 1 ID is required respectively. In the case of transmitting and receiving "manufacturing-related instruction", in the case of transmitting and receiving "manufacturing-related acquisition", in the case of transmitting and receiving "manufacturing-related setting", and in the case of transmitting and receiving "manufacturing-related reception", 57 IDs are required respectively.

[0094] "Error notification" is information sent from the BMS 12 to the BMU 20 as battery information when an abnormality occurs in the battery module 10. In the case of transmitting and receiving "error notification", 1 ID is required.

[0095] Next, consider the case of transmitting and receiving instruction information or battery information between one BMU 20 and one BMS 12. As Figure 5 shown, when transmitting and receiving instruction information or battery information regarding all data categories between one BMU 20 and one battery module 10 (BMS 12), usually 421 IDs are required.

[0096] However, since the total number of IDs that can be used in standard format CAN communication is 2048, the number of IDs that can be used by one BMS 12 is 292 (≒2048 / 7). Therefore, in the case of assigning different IDs to all transmitted and received data frames, there will be a shortage of IDs and information regarding all data categories cannot be transmitted and received.

[0097] In contrast, in the present embodiment, when transmitting and receiving information regarding each data category, the same ID is assigned to multiple data frames. Therefore, the ID required for transmitting and receiving information regarding each data category is 1. Therefore, in the case of transmitting and receiving information regarding all data categories, only 17 IDs are needed.

[0098] Next, the relationship between the data stored in the data field of the data frame and the ID will be described. Figure 6 is a schematic diagram for explaining the data stored in the conventional data field. Figure 7 is a schematic diagram for explaining the data stored in the data field of the present embodiment. Here, the case where data including the unit voltages #1 to #12 and the maximum voltages #1 to #12 of 12 secondary battery cells is transmitted as transmission data will be described. It should be noted that in Figure 6and Figure 7 In the example of Figure 7 , “cell voltage” is set to represent “the current value of the cell voltage”.

[0099] As Figure 6 shown, conventionally, the divided data obtained by dividing the transmission data is stored in all areas of the data field. For example, in the case of dividing and transmitting the transmission data of the cell voltages #1 to #12 of 12 battery cells and the maximum voltages #1 to #12 of the respective battery cells, conventionally, 6 data frames are required. And different IDs (0x000 to 0x005) are assigned to each data frame. That is, conventionally, 6 IDs are required to transmit this transmission data.

[0100] In contrast, as Figure 7 shown, in the present embodiment, the sequence number and the data type are stored in the first area of the data field, and the divided data is stored in the second area. For example, similar to the example shown in Figure 6 , in the case of dividing and transmitting the transmission data of the cell voltages #1 to #12 and the maximum voltages #1 to #12, in the present embodiment, 8 data frames are required, that is, more data frames than conventionally. Figure 6 However, by storing the sequence number and the data type in the first area of the data field, each data frame can be identified thereby, and thus the same ID (0x000) can be assigned to each data frame. That is, in the present embodiment, only 1 ID is required to transmit this transmission data.

[0101] In this way, in the present embodiment, as compared with the conventional case, the number of IDs required for transmitting the transmission data of the same size can be reduced. Therefore, even in the case where it is necessary to transmit data frames exceeding the available number of IDs, it is possible to transmit a plurality of data frames while suppressing the shortage of IDs.

[0102] As described above, when the BMS12 or the BMU20, which is the transmission device of the present embodiment, stores and transmits the transmission data by dividing it into a plurality of data frames, the same ID is assigned to the plurality of data frames. In addition, in the plurality of data frames, the BMS12 or the BMU20 divides the data field into a first area and a second area, stores the sequence number and the data type as identification information in the first area, and stores the transmission data in the second area.

[0103] In this way, the divided data obtained by dividing the transmission data into a plurality of parts is stored in a plurality of data frames assigned with the same ID and transmitted, so that the transmission data can be appropriately transmitted. In addition, since the same ID is assigned to the plurality of data frames, the shortage of IDs can be suppressed.

[0104]

[0105] ​In addition, when receiving transmission data by the BMU20 or BMS12 which is a receiving device of the present embodiment, with respect to a plurality of data frames given the same ID, it refers to a data field divided into a first area and a second area. Then, the BMU20 or BMS12 combines the transmission data stored in the second area according to the serial number and data type which are identification information regarding the transmission data and stored in the first area.

[0106] In this way, since the transmission data which is given the same ID and stored separately in the second areas of a plurality of data frames is combined based on the identification information stored in the first area, the transmission data can be received appropriately.

[0107] The above has described the present embodiment, but the present disclosure is not limited to the above embodiment, and various modifications and applications can be made without departing from the gist of the present disclosure. In the present embodiment, the case where CAN is applied as a communication protocol has been described, but it is not limited thereto. For example, it can also be applied to a communication standard using a protocol in which only one frame given an inherent ID can be transmitted in one transmission and the ID is limited.

[0108] All the disclosures of the specification, drawings, and abstract included in the Japanese application of Japanese Patent Application No. 2023-007034 filed on January 20, 2023 are incorporated herein by reference.

[0109] Explanation of Reference Numerals

[0110] 1 Power storage device

[0111] 2 Bus

[0112] 10 Battery module

[0113] 11 Secondary battery

[0114] 12 BMS

[0115] 20 BMU

[0116] 21 Data acquisition unit

[0117] 22 Data segmentation unit

[0118] 23 Frame generation unit

[0119] 24 Transceiver unit

[0120] 25 Data combination unit.

Claims

1. A transmitting device stores the transmitted data by dividing it into multiple frames and transmits the frames. The transmitting device has a frame generation unit that assigns the same identifier to the multiple frames. Among the multiple frames, the data fields different from the storage unit of the identifier are divided into a first area and a second area, and identification information is stored in the first area, while the transmitted data is stored in the second area. The identification information is information for distinguishing the multiple frames from each other.

2. The transmitting device according to claim 1, wherein the identification information includes a sequence number indicating the order of the transmitted data stored in the second area of the multiple frames.

3. The transmitting device according to claim 2, wherein it includes a transmitting unit that transmits the multiple frames in the order of the sequence number.

4. The transmitting device according to claim 1, wherein the frame generation unit assigns the same identifier to the multiple frames storing the transmitted data of the same data category.

5. The transmitting device according to claim 1, wherein the transmitted data of the same data category includes the transmitted data with different data contents, and the identification information includes a data type number indicating the data content of the transmitted data.

6. The transmitting device according to claim 1, wherein the transmitted data includes data related to a secondary battery.

7. A receiving device receives the transmitted data stored by being divided into multiple frames. The receiving device has a data combining unit that, for the multiple frames assigned the same identifier, refers to the data field divided into a first area and a second area, and combines the transmitted data stored in the second area based on the identification information about the transmitted data stored in the first area.

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