Management device, battery data transmission device, transmission system

Abstract

To make it possible to maintain the transmission of information even in a situation where transmission errors occur by changing an encoding method between a normal time and an abnormal time, in data encoding for transmitting battery information.SOLUTION: A management device includes: a transmission control unit that communicates with a battery data transmission device that transmits encoded data obtained by encoding battery data, which is data about a battery, via a transmission path; an abnormality detection unit that detects an abnormality in the transmission path; and a command unit that outputs a command to shorten the data length of the encoded data to the battery data transmission device when the abnormality detection unit detects an abnormality in the transmission path.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a management device, a battery data transmission device, and a transmission system.

Background Art

[0002] In a battery system used in a hybrid vehicle, an electric vehicle, etc., a battery pack configured by connecting a large number of single battery cells of a secondary battery in series is used. In such a battery pack, for the capacity calculation and protection management of each single battery cell, the single battery cells are managed using a monitoring IC that monitors the state of the single battery cells and a control IC that controls the charge and discharge state of the single battery cells. Although a wired connection is the mainstream between the monitoring IC and the control IC, for various reasons such as weight reduction, cost reduction, expansion of in-vehicle space, improvement of layout freedom, and reduction of short-circuit risk during a collision by reducing the connection cable (communication harness), the application of wireless communication has been studied. On the other hand, the monitoring and control of battery cells are performed at very short intervals (several tens of ms to one hundred ms), and robust communication is required. However, the inside of the vehicle is affected by various disturbances such as various metals, high currents, wireless communication of passengers and the vicinity, and the communication quality deteriorates. Patent Document 1 discloses a method for compressing and decompressing battery data that stores data in pairs of current values and voltage values at each time of a battery. When compressing the data, a predicted value of the current change amount this time is calculated using the amount of change in the voltage value between the previous time and this time, a difference between the predicted value of the current change amount this time and the actual amount of change in the current value this time is calculated, and this difference is stored as data. When decompressing the data, a predicted value of the current change amount this time is calculated using the amount of change in the voltage value between the previous time and this time, and the difference between the predicted value of the current change amount this time and the actual current value this time is added to the predicted value of the current change amount this time to calculate the amount of change in the current value this time.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the invention described in Patent Document 1, there is room for improvement in countermeasures against transmission errors.

Means for Solving the Problems

[0005] A management device according to a first aspect of the present invention includes a transmission control unit that communicates with a battery data transmission device that transmits encoded data obtained by encoding battery data, which is data related to a battery, via a transmission line, an abnormality detection unit that detects an abnormality in the transmission line, and a command unit that outputs a command to shorten the data length of the encoded data to the battery data transmission device when the abnormality detection unit detects an abnormality in the transmission line. , decoding the encoded data using a symbolization table to obtain a battery data decoder, a storage unit for storing the battery data, and the memory an update unit that updates the symbolization table using the battery data stored in the unit; further comprising, the transmission control unit, the symbolization table updated by the update unit to the battery Send to the data transmission device It has. A battery data transmission device according to a second aspect of the present invention includes an encoding unit that generates encoded data obtained by encoding battery data, which is data related to a battery, a transmission control unit that transmits the encoded data to a management device via a transmission line, and an abnormality detection unit that detects an abnormality in the transmission line. The encoding unit has at least a first mode and a second mode as operation modes, the encoded data in the second mode has a shorter data length than the encoded data in the first mode, and when the abnormality detection unit detects an abnormality in the transmission line, the encoding unit is made to apply the second mode. , further comprising a cell controller for acquiring information from the battery , the abnormality detection unit further uses the information acquired by the cell controller to detect an abnormality of the battery, and the abnormality detection unit, when the abnormality detection unit detects an abnormality of the transmission path or the battery, causes the encoding unit to apply the second mode It has. A transmission system according to a third aspect of the present invention includes a battery data transmission device that transmits encoded data obtained by encoding battery data, which is data related to a battery, via a transmission line, and a management device that receives the encoded data. The transmission system includes an abnormality detection unit that detects an abnormality in the transmission line. The battery data transmission device includes an encoding unit that generates the encoded data using the battery data, and a transmission control unit that transmits the encoded data to the management device via the transmission line. The encoding unit has at least a first mode and a second mode as operation modes. The encoded data in the second mode has a shorter data length than the encoded data in the first mode. When the abnormality detection unit detects an abnormality in the transmission line, the encoding unit is caused to apply the second mode. , the battery The data transmission device further comprises a cell controller for acquiring information from the battery, and the abnormality detection unit further uses the information acquired by the cell controller to detect an abnormality of the battery , and when the abnormality detection unit detects an abnormality of the transmission path or the battery, the encoding unit is caused to apply the second mode.

Advantages of the Invention

[0006] According to the present invention, in data encoding for transmitting battery information, the encoding method is changed between normal times and abnormal times, and information transmission can be maintained even in a situation where a transmission error occurs.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Modes for Carrying Out the Invention

[0008] - First Embodiment - Hereinafter, a first embodiment of the transmission system will be described with reference to FIGS. 1 to 5.

[0009] (Overall Configuration) FIG. 1 is an overall configuration diagram of a transmission system S1 in the first embodiment. The transmission system S1 includes a motor 11, an inverter 12, a current sensor 13, a plurality of cell groups CG, a plurality of battery data transmission devices B, a management device M, and a host controller 20. The plurality of battery data transmission devices B are numbered to distinguish each of them. Hereinafter, the entire plurality of cell groups CG and the individual cells included in each cell group CG are also referred to as "batteries".

[0010] The battery data transmission device B includes a cell controller 14, a transmission control unit 15, and an encoding unit 16. The configuration and operation of each battery data transmission device B are the same. Hereinafter, in order to explain the specific operation, there may be cases where the battery data transmission device B1 is used for explanation. That is, hereinafter, there may be cases where the configuration of the battery data transmission device B1, namely, the cell controller 14-1, the transmission control unit 15-1, and the encoding unit 16-1, is used for explanation.

[0011] The management device M includes a transmission control unit 15-z, a decoding unit 17, an abnormality detection unit 18, and a battery controller 19. The transmission control units 15-1 and 15-n, which are transmission control units included in the battery data transmission device B, and the transmission control unit 15-z included in the management device M are each connected by a transmission line T. The transmission line T is a space for wireless communication, and the transmission control unit 15 performs wireless communication.

[0012] The inverter 12 supplies the power stored in the cell group CG to the motor 11, or accumulates the power obtained from the motor 11 in the cell group CG. The current sensor 13 measures the current flowing between the inverter 12 and the cell group CG and transmits it to the battery controller 19.

[0013] The cell controller 14, the encoding unit 16, the decoding unit 17, the abnormality detection unit 18, and the battery controller 19 are, for example, any one of a computer, an FPGA (Field Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit) which is an integrated circuit for a specific purpose. The computer includes a CPU which is a central processing unit, a ROM which is a read-only storage device, and a RAM which is a readable and writable storage device, and the CPU expands and executes the program stored in the ROM in the RAM to perform various operations.

[0014] The cell controller 14 controls a cell group CG that combines a plurality of cells. The cell controller 14 performs control specified by the management device M via the transmission line T. The cell controller 14 includes at least a voltmeter and measures the voltage of each cell. The cell controller 14 may include other sensors, for example, the temperature of each cell may be measured. The cell controller 14 may calculate the state of charge (SoC) of each battery. When the cell controller 14 receives a request command described later from the management device M, it transmits information on the connected cell group. The request command includes a designation of an encoding mode, and the cell controller 14 outputs information on the designated encoding mode and information on the cell group CG to the encoding unit 16.

[0015] The transmission control units 15-1 and 15-n included in the battery data transmission device B transmit the information encoded by the encoding unit 16 to the management device M. Also, the transmission control units 15-1 and 15-n output the information received from the management device M to the cell controller 14. The transmission control unit 15-z included in the management device M outputs the information received from the battery data transmission device B to the decoding unit 17. The transmission control unit 15 is a communication module.

[0016] The encoding unit 16 encodes the information on the cell group CG output by the cell controller 14 in the designated encoding mode and outputs it to the transmission control unit 15. The encoding unit 16 has a plurality of encoding modes and operates in the encoding mode designated by the cell controller 14. The decoding unit 17 decodes the information on the cell group CG received from the battery data transmission device B and outputs it to the abnormality detection unit 18 and the battery controller 19.

[0017] The abnormality detection unit 18 detects an abnormality occurring in the transmission line T. Details of the abnormality detection will be described later. The battery controller 19 controls the charging and discharging of the battery, that is, the cell group CG, according to the instructions of the upper controller 20. Further, the battery controller 19 transmits to the upper controller 20 whether the battery is in a normal state or not. The battery controller 19 transmits a request command for requesting the transmission of battery data to each cell controller 14 every time a predetermined time, for example, 20 ms, elapses. This request command includes information specifying the encoding mode. The cell controller 14 acquires the battery data, performs encoding in the specified mode to obtain encoded data, and transmits it to the management device M. The mode may be the same for all cell controllers or may be changed for each cell controller. Note that the battery data is, for example, the voltage, current, temperature, charge rate, deterioration state, etc. of a single battery cell.

[0018] (Abnormality Detection Unit) When detecting an abnormality using the data reception interval, the abnormality detection unit 18 determines that an abnormality has occurred in the transmission line T when the interval of the time at which the transmission control unit 15-3 receives data from each battery data transmission device B is longer than the threshold value. Since the battery controller 19 transmits a request command to each battery data transmission device B at a predetermined time interval, if communication is being performed normally, the request command can be obtained after a very short time. Therefore, the abnormality detection unit 18 determines that an abnormality has occurred in the transmission line T because the interval of the time for receiving the request command is longer than the threshold value.

[0019] When detecting an abnormality using the data reception interval, the abnormality detection unit 18 determines that an abnormality has occurred in the transmission line T when the interval of the time at which the transmission control unit 15-3 receives data from each battery data transmission device B is longer than the threshold value. Since the battery controller 19 transmits a request command to each battery data transmission device B at a predetermined time interval, if communication is being performed normally, the request command can be obtained after a very short time. Therefore, the abnormality detection unit 18 determines that an abnormality has occurred in the transmission line T because the interval of the time for receiving the request command is longer than the threshold value.

[0020] This threshold value may be a predetermined fixed value or a value calculated based on the acquired battery information. Generally, a normal voltage and state of charge (SoC) range are defined for the cells, and these pieces of information may be used. For example, the abnormality detection unit 18 may determine the threshold value using the latest SoC and the current flowing through the cell. For example, if the SoC acquired one second ago was 45% and the SoC acquired this time is 44%, since it is decreasing at a rate of 1% per second, if the lower limit of the SoC is assumed to be 30%, it will reach in about 15 seconds. In this case, the abnormality detection unit 18 may set the threshold value of the data reception interval to 15 seconds or a value obtained by multiplying 15 seconds by a certain coefficient (for example, 1.5 seconds when the coefficient is 0.1). Also, when using the current amount, the integration value of the observed current amount may be calculated and converted into SoC to estimate the time to reach the set upper and lower limits of SoC or voltage, and the threshold value may be calculated based on this. Further, a plurality of threshold values may be set using a plurality of coefficients and the like, and the encoding method and the transmission data may be changed according to each threshold value.

[0021] When detecting an abnormality using the number of retransmission requests, the abnormality detection unit 18 determines that an abnormality has occurred in the transmission path T when the number of retransmission requests per unit time is greater than a predetermined threshold value. This retransmission request may be a request from the battery data transmission device B to the management device M or a request from the management device M to the battery data transmission device B. Further, this retransmission request may occur at the level of the communication protocol, for example, below the sixth layer in the OSI reference model, or may occur at the application layer.

[0022] When detecting an abnormality using the reception level, the abnormality detection unit 18 determines that an abnormality has occurred in the transmission path T when the current level when any radio wave is observed in the wireless communication between the management device M and the battery data transmission device B is lower than a predetermined threshold value. Further, when detecting an abnormality using an existing error detection method, for example, a CRC error, the abnormality detection unit 18 calculates the CRC (Cyclic Redundancy Check) of the data received from the battery data transmission device B, and determines that an abnormality has occurred in the transmission path T when a CRC error occurs or when the number of occurrences exceeds a predetermined threshold value.

[0023] (Coding mode) The coding mode includes two modes: a normal mode and an abnormal mode. The operations of the normal mode and the abnormal mode are not limited to specific operations, and the data length may be shorter in the abnormal mode than in the normal mode. Hereinafter, the operations of each typical mode will be described. The information of the cell transmitted by the cell controller 14 is not limited to voltage information, but for simplicity of description here, only the transmission of voltage will be described. Hereinafter, the normal mode may also be referred to as the "first mode", and the abnormal mode may also be referred to as the "second mode".

[0024] The encoding unit 16 of the cell controller 14 designated to operate in the normal mode may use, as encoded data, an enumeration of the latest values of the voltages of each cell, or the difference from past measurement values, or the difference from a reference cell within the cell group CG. Further, instead of using the numerical values as they are as encoded data, the cell controller 14 may use variable-length encoding using known entropy, for example, Huffman encoding or encoding data using context-adaptive encoding (CAVLC, CABAC, etc.). When performing encoding based on a table created in advance such as Huffman encoding, it can be said that the encoding unit 16 performs a compression process of compressing the battery data into encoded data with an equal or shorter data length.

[0025] The cell controller 14 specified to operate in the abnormal mode may transmit only the minimum voltage value and the maximum voltage value among the voltages of each cell included in the cell group CG, or may transmit the minimum voltage value, the maximum voltage value, the identifier of the cell with the minimum voltage, and the identifier of the cell with the maximum voltage. Further, the cell controller 14 specified to operate in the abnormal mode may transmit the voltage values of all cells with a coarser accuracy than in the normal mode.

[0026] (Transmitted data) FIG. 2 is a schematic diagram showing the transmitted data transmitted by the transmission control unit 15 of the battery data transmission device B in the normal mode and the abnormal mode. In any mode, a communication header FH is included at the head of the transmitted data. The communication header FH is information indicating the destination of the transmitted data, for example, an IP address or a CAN-ID. In the normal mode, following the communication header FH, there may be a case where non-compressed data FNC is stored, or a case where an encoding header FCH and normal-time encoded data FCD are included. The non-compressed data FNC is a list of information about the battery without compression, for example, a list of voltage values of each cell in order.

[0027] The encoding header FCH is information necessary for interpreting the normal-time encoded data FCD, such as the compression method and the data length. The normal-time encoded data FCD is the battery data encoded using the encoding header FCH. For example, assume that a plurality of encoding tables are stored in advance in the encoding unit 16 and the decoding unit 17. In this case, the encoding header FCH may store the identifier of the encoding table to be used, and the normal-time encoded data FCD may be the battery data encoded with that encoding table.

[0028] The transmission data in the abnormal mode includes an abnormal encoding header FIC and abnormal encoding data FID following the communication header FH. The abnormal encoding header FIC is information necessary for interpreting the abnormal encoding data FID, such as the type of data and the data length. The abnormal encoding data FID is obtained by encoding the battery data using the abnormal encoding header FIC. The type of data is, for example, information indicating whether it is the voltage of all cells included in the cell group CG or the maximum voltage and the minimum voltage in the cell group CG. In FIG. 2, the data obtained by removing the communication header FH from the transmission data is the encoded data.

[0029] In the present embodiment, the combination of the encoding in the normal mode and the encoding in the abnormal mode can be freely selected, and an enormous number of combinations can be considered. The constraint on the encoding in the two modes in the present embodiment is that the encoded data in the abnormal mode has a shorter data length than the encoded data in the normal mode. However, the length of the data referred to here is the size of the data in the application layer of the OSI reference model, and is not the size of each packet (also called a datagram or a frame) in the second layer and the third layer of the OSI reference model. In the present embodiment, when an abnormality is detected in the transmission path T, it is intended to reduce the data so that the cell information can easily reach even if the amount of information is reduced.

[0030] (Flowchart) FIG. 3 is a flowchart showing the operation of the management device M. The management device M executes the processing shown in FIG. 3 every time a predetermined time, for example, 20 ms, has elapsed. Note that FIG. 3 illustrates the transmission and reception of data between the management device M and one battery data transmission device B. The management device M executes the processing shown in FIG. 3 for the number of battery data transmission devices B included in the transmission system S1.

[0031] In step S311, the battery controller 19 generates a request command for a specific battery data transmission device B and transmits it using the transmission control unit 15-3. As described above, the request command includes information specifying the encoding mode. The battery controller 19 includes in the request command a specification of an encoding mode indicating either the normal mode or the abnormal mode according to the detection result immediately before by the abnormality detection unit 18. Specifically, when the detection result immediately before of the battery data transmission device B to be transmitted is normal, information indicating the normal mode is included, and when the detection result immediately before of the battery data transmission device B to be transmitted is abnormal, information indicating the abnormal mode is included.

[0032] In the subsequent step S312, the battery controller 19 receives encoded data from the battery data transmission device B. In the subsequent step S313, the battery controller 19 decodes the encoded data using the decoding unit 17. In the subsequent step S314, the battery controller 19 estimates the battery state. In the subsequent step S315, the battery controller 19 transmits a control command to the cell controller 14 based on at least one of the battery state estimated in step S314 and the command from the upper controller 20, and ends the process shown in FIG. 3.

[0033] As described above, in step S311, when the abnormality detection unit 18 immediately before detects an abnormality in the transmission path T, the battery controller 19 transmits to the battery data transmission device B a request command including a command to set the encoding mode to the abnormal mode. The command to set the encoding mode to the abnormal mode can also be said to be a command to shorten the data length of the encoded data. Therefore, it can also be said that the battery controller 19 has a role as a "command unit" that outputs a command to shorten the data length of the encoded data.

[0034] Although not shown in FIG. 3, when the abnormality detection unit 18 detects an abnormality, or when sensor data cannot be obtained from the battery data transmission device B determined to be in the abnormal mode, the management device M may notify the upper controller 20 that an abnormality has occurred in the battery of the transmission system S1.

[0035] Figure 4 is a flowchart showing the operation of the battery data transmission device B. When the battery data transmission device B is started, it performs the operations shown in Figure 4, and when the operations shown in Figure 4 are completed, it performs the operations shown in Figure 4 again. That is, the battery data transmission device B repeatedly executes the operations shown in Figure 4.

[0036] In step S321, the battery data transmission device B waits for the reception of a request command from the battery data transmission device B, and when it is received, it proceeds to step S322. As described above, the received request command includes information specifying an encoding mode, specifically, information specifying either the normal mode or the abnormal mode. Note that the request command received in this step is transmitted in step S311 of Figure 3.

[0037] In step S322, the cell controller 14 performs battery data observation, that is, acquires battery information. In the subsequent step S323, the cell controller 14 designates an encoding mode to the encoding unit 16 to cause it to encode the battery data. The encoding mode designated by the cell controller 14 in this step is the one designated in the request command received in step S321.

[0038] In the subsequent step S324, the transmission control unit 15 transmits the encoded data, which is the battery data encoded by the encoding unit 16, to the management device M. Note that this encoded data is received in step S312 of Figure 3. In the subsequent step S325, the battery data transmission device B receives a control command from the management device M. The request command received in this step is transmitted in step S315 of Figure 3. In the subsequent step S325, the cell controller 14 executes cell control according to the control command received in step S325 and ends the process shown in Figure 4.

[0039] FIG. 5 is a flowchart showing the abnormality detection process by the abnormality detection unit 18. When the management device M transmits a request command to the battery data transmission device B, the abnormality detection unit 18 starts the operation shown in FIG. 5. For example, when the management device M transmits a request command to each of the 10 battery data transmission devices B, the management device M starts the operation of FIG. 5 corresponding to each of the transmitted battery data transmission devices B. In other words, the process of the flowchart shown in FIG. 5 is executed for any specific battery data transmission device B. In the description of this flowchart, the battery data transmission device B to be executed is referred to as the "corresponding battery data transmission device B".

[0040] In step S331, the abnormality detection unit 18 determines whether or not it has received encoded data from the corresponding battery data transmission device B. If the abnormality detection unit 18 determines that it has received encoded data from the corresponding battery data transmission device B, it proceeds to step S332. If it determines that it has not received encoded data from the corresponding battery data transmission device B, it proceeds to step S335. In step S332, the abnormality detection unit 18 determines whether or not the reception level of the communication with the corresponding battery data transmission device B is normal. The communication to be evaluated in this step may be the communication when receiving the encoded data or the communication in the initialization of the wireless communication or the like. If the abnormality detection unit 18 determines that the reception level of the communication with the corresponding battery data transmission device B is normal, it proceeds to step S333. If it determines that the reception level of the communication with the corresponding battery data transmission device B is not normal, it proceeds to step S336.

[0041] In step S333, the abnormality detection unit 18 determines whether or not the data received from the corresponding battery data transmission device B is normal. The abnormality detection unit 18 applies a known error detection method (for example, CRC) to the data received from the corresponding battery data transmission device B. If it determines that the data is normal, it proceeds to step S334. If it determines that the data received from the corresponding battery data transmission device B is not normal, it proceeds to step S336.

[0042] In step S334, the abnormality detection unit 18 determines that the next encoding mode to be specified for the corresponding battery data transmission device B is the normal mode, and ends the process shown in FIG. 5. In step S335, the abnormality detection unit 18 determines whether the elapsed time after the request command is transmitted is shorter than a predetermined threshold value th. When the abnormality detection unit 18 determines that the elapsed time after the request command is transmitted is shorter than the predetermined threshold value th, it returns to step S331, and when it determines that the elapsed time after the request command is transmitted is equal to or longer than the predetermined threshold value th, it proceeds to step S336. In step S336, the abnormality detection unit 18 determines that the next encoding mode to be specified for the corresponding battery data transmission device B is the abnormal mode, and ends the process shown in FIG. 5.

[0043] According to the first embodiment described above, the following operational effects can be obtained. (1) The management device M includes a transmission control unit 15-z that communicates with a battery data transmission device B that transmits, via a transmission path T, encoded data obtained by encoding battery data that is data related to a battery, an abnormality detection unit 18 that detects an abnormality in the transmission path T, and a battery controller 19 that also functions as a command unit that outputs a command to shorten the data length of the encoded data to the battery data transmission device B when the abnormality detection unit 18 detects an abnormality in the transmission path T. Therefore, in data encoding for transmitting battery information, the encoding method is changed between normal and abnormal times, and information transmission can be maintained even in a situation where a transmission error occurs. Specifically, in the abnormal mode, since the data length becomes shorter, retransmission is easier and information is more easily transmitted compared to the case where the data length is long.

[0044] (2) The transmission path T is a space for wireless communication.

[0045] (3) The abnormality detection unit 18 detects an abnormality using the time interval for receiving encoded data from the battery data transmission device B, the number of retransmission requests from the battery data transmission device B, the level of the communication signal received from the battery data transmission device B, and data errors in the encoded data. Therefore, an abnormality in the transmission path T can be detected using various states resulting from the occurrence of an abnormality in the transmission path T.

[0046] (4) The transmission control unit 15-z communicates with a plurality of battery data transmission devices B. The abnormality detection unit 18 individually detects an abnormality in the transmission path for each of the plurality of battery data transmission devices B. The battery controller 19, which also operates as a command unit, outputs a command to shorten the data length of the encoded data to the battery data transmission device B related to the transmission path in which the abnormality detection unit 18 has detected an abnormality. Therefore, the battery data transmission device B in which no abnormality in the transmission path T is detected is made to execute encoding in the normal mode, and rich information can be obtained.

[0047] (5) The transmission system S1 includes a battery data transmission device B that transmits encoded data obtained by encoding battery data, which is data related to a battery, via a transmission path T, and a management device M that receives the encoded data. The transmission system S1 includes an abnormality detection unit 18 that detects an abnormality in the transmission path. The battery data transmission device B includes an encoding unit 16 that generates encoded data using the battery data, and transmission control units 15-1 to 15-n that transmit the encoded data to the management device via the transmission path T. The encoding unit 16 has at least a normal mode and an abnormal mode as operation modes. The encoded data in the abnormal mode has a shorter data length than the encoded data in the normal mode. When the abnormality detection unit 18 detects an abnormality in the transmission path T, the encoding unit 16 is made to apply the abnormal mode.

[0048] (Modification Example 1) In the above-described first embodiment, the abnormality detection unit 18 detected the abnormality in the transmission path T using all four of the data reception interval, the number of retransmission requests, the reception level, and the data error. However, the abnormality detection unit 18 may detect the abnormality in the transmission path T using at least one of the data reception interval, the number of retransmission requests, the reception level, and the data error.

[0049] (Modification Example 2) In the first embodiment described above, the cell controller 14 specified an encoding mode for the encoding unit 16. However, the cell controller 14 does not necessarily have to have a function of specifying an encoding mode for the encoding unit 16. In this case, the battery data transmission device B has an encoding mode switching unit that interprets at least a part of the request command received from the management device M and specifies an encoding mode for the encoding unit 16.

[0050] FIG. 6 is a functional configuration diagram of the battery data transmission device B in this modified example. The battery data transmission device B in this modified example includes an encoding mode switching unit 1A in addition to the cell controller 14, the transmission control unit 15, and the encoding unit 16. In this modified example, the transmission control unit 15 transmits the received request command to the cell controller 14 and the decoding unit 17. The operation of the cell controller 14 is the same as that of the first embodiment except that it does not transmit the encoding mode to the encoding unit 16. The decoding unit 17 specifies an encoding mode for the encoding unit 16 based on the received request command.

[0051] (Modified Example 3) When an abnormal mode is specified for the encoding mode by the management device M, the cell controller 14 may reduce the types of data transmitted to the encoding unit 16 compared to normal times. For example, in the normal mode, the cell controller 14 may transmit information on the voltage and temperature of each cell to the encoding unit 16, and in the abnormal mode, only the voltage of each cell may be transmitted to the encoding unit 16. According to this modified example, even without changing the encoding mode in the encoding unit 16 between the normal mode and the abnormal mode, by reducing the types of data transmitted by the cell controller 14 to the encoding unit 16, it is possible to make it easier to receive the encoded data in the abnormal mode.

[0052] (Modified Example 4) In the above-described first embodiment, each time the abnormality detection unit 18 executed the abnormality detection process shown in FIG. 5, it determined the encoding mode of each battery data transmission device B. However, the abnormality detection unit 18 may add additional conditions for switching from the abnormal mode to the normal mode. For example, when the abnormality detection unit 18 determines that it is in the abnormal mode, it will only start to set the encoding mode specified in the request command transmitted to the battery data transmission device B to the normal mode when it has determined that it is in the normal mode a predetermined number of times, for example, three times in a row thereafter. In other words, in step S334 of FIG. 5, the encoding mode specified in the request command is set to the normal mode only when the normal mode has been continuously selected in the most recent past three or more times, and in other cases, the encoding mode specified in the request command is set to the abnormal mode.

[0053] Note that instead of continuing for a predetermined number of times, the abnormality detection unit 18 may be conditioned to continue for a predetermined time. In this case, in step S334 of FIG. 5, the encoding mode specified in the request command is set to the normal mode only when the normal mode has been continuously selected in the most recent predetermined time, for example, one hour, and in other cases, the encoding mode specified in the request command is set to the abnormal mode.

[0054] (Modification Example 5) In the above-described first embodiment, the battery controller 19 transmitted the request command to the battery data transmission device B. However, the abnormality detection unit 18 may transmit the request command to the battery data transmission device B. In this case, it can be said that the abnormality detection unit 18 has the role of a "command unit" that outputs a command to shorten the data length of the encoded data. In this modification example, the abnormality detection unit 18 may transmit a request command to each battery data transmission device B every time a predetermined time has elapsed, or the timing of transmitting the request command may be managed by the battery controller 19 as in the first embodiment, and the abnormality detection unit 18 may generate a request command based on a transmission command from the battery controller 19.

[0055] (Modification Example 6) The abnormality detection unit 18 may evaluate the reception interval for receiving the encoded data instead of evaluating the elapsed time after the request command is transmitted. In this case, in step S335 of FIG. 5, it may be determined whether the elapsed time since the immediately preceding reception of the encoded data is less than a predetermined threshold value.

[0056] (Modification Example 7) In the above-described first embodiment, the battery controller 19 individually determines the encoding mode for each battery data transmission device B. However, the battery controller 19 may collectively change the encoding mode of the connected battery data transmission devices B. In this case, the battery data transmission device B designates the normal mode only when there is no abnormality in all the connected battery data transmission devices B, and designates the abnormal mode for all the battery data transmission devices B when an abnormality is detected in even one battery data transmission device B.

[0057] (Modification Example 8) The transmission path T may be a signal line, or a signal line and space may be mixed. In this case, the transmission control unit 15 will support both wireless communication and wired communication.

[0058] (Modification Example 9) When the voltage information of each cell is included in the encoded data in the normal mode, the abnormality detection unit 18 may detect an abnormality in the battery cells using the battery data decoded by the decoding unit 17. For example, the abnormality detection unit 18 can determine the normality of the cells based on whether the voltage of each cell is within a predetermined range. In this case, the battery controller 19 transmits a request command including a signal designating the abnormal mode as the encoding mode to the battery data transmission device B not only when the abnormality detection unit 18 detects an abnormality in the transmission path T, but also when an abnormality in the battery is detected.

[0059] According to this modification example, the following operational effects can be obtained. (6) The management device M includes a decoding unit 17 that decodes the encoded data to obtain battery data. The abnormality detection unit 18 detects an abnormality of the battery using the battery data decoded by the decoding unit 17. The battery controller 19 that also operates as a command unit outputs a command to shorten the data length of the encoded data to the battery data transmission device B when the abnormality detection unit 18 detects an abnormality in the transmission path T or the battery. Therefore, even when there is an abnormality in the battery, the certainty of information transmission can be prioritized over the richness of information.

[0060] - Second Embodiment - Referring to FIGS. 7 to 8, a second embodiment of the transmission system will be described. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the differences will be mainly described. For points not particularly described, they are the same as those in the first embodiment. In this embodiment, it is mainly different from the first embodiment in that the abnormality detection unit is provided in the battery data transmission device.

[0061] FIG. 7 is an overall configuration diagram of the transmission system S2 in the second embodiment. In this embodiment, the management device M does not include the abnormality detection unit 18, and the battery data transmission device B includes the abnormality detection unit 18.

[0062] In this embodiment, the request command transmitted by the management device M does not include information specifying the encoding mode. The cell controller 14 determines the encoding mode based on the detection result of the abnormality detection unit 18 included in the battery data transmission device B to which it belongs, rather than the information included in the request command. Specifically, the cell controller 14-1 operates according to the encoding mode determined by the abnormality detection unit 18-1. The cell controller 14-n operates according to the encoding mode determined by the abnormality detection unit 18-n.

[0063] FIG. 8 is a flowchart showing the processing of the abnormality detection unit 18 in the second embodiment. Compared with the operation of the abnormality detection unit 18 in the first embodiment, step S331 is changed to step S331A, and step S337 is added.

[0064] In step S331A, the abnormality detection unit 18 determines whether the elapsed time since the battery data transmission device B last received a request command from the management device M is shorter than a predetermined threshold th2. This threshold is, for example, the prescribed time interval at which the management device M transmits a request command to each battery data transmission device B. When the abnormality detection unit 18 determines that the elapsed time is shorter than the threshold th2, it proceeds to step S332A, and when it determines that the elapsed time is equal to or longer than the threshold th2, it proceeds to step S336.

[0065] The operations in steps S332 and S333 are the same as those in the first embodiment, and thus the description thereof is omitted. When the abnormality detection unit 18 makes an affirmative determination in step S333, it proceeds to step S337. In step S337, the abnormality detection unit 18 determines whether each cell is normal by using various types of information regarding the cell group CG acquired by the cell controller 14. When the abnormality detection unit 18 determines that all cells are normal, it proceeds to step S334, and when it determines that at least one cell is not normal, it proceeds to step S336. Various known methods can be used for the abnormality detection unit 18 to determine the normality of the cells. For example, the abnormality detection unit 18 may determine the normality of the cells based on whether the voltage of each cell is within a predetermined range, or may determine the normality of the cells based on whether the correlation between the time change in the voltage and the time change in the current of each cell satisfies a predetermined relational expression.

[0066] According to the second embodiment described above, the following operational effects can be obtained. (7) The battery data transmission device B includes an encoding unit 16 that generates encoded data obtained by encoding battery data, which is data related to a battery, transmission control units 15-1 to 15-n that transmit the encoded data to the management device M via the transmission path T, and an abnormality detection unit 18 that detects an abnormality in the transmission path T. The encoding unit 16 includes at least a normal mode and an abnormal mode as operation modes. The encoded data in the abnormal mode has a shorter data length than the encoded data in the normal mode. When the abnormality detection unit 18 detects an abnormality in the transmission path T, the encoding unit 16 is made to apply the abnormal mode.

[0067] (8) The encoding unit 16 performs a compression process of compressing the battery data into encoded data having an equal or shorter data length.

[0068] (Modification of the Second Embodiment) The management device M may include information on a request interval, which is a time interval until the next request command is transmitted, in the request command transmitted to each battery data transmission device B. In this case, the abnormality detection unit 18 may use the request interval included in the request command as the threshold value in step S331A, or may use a time obtained by adding a predetermined margin to the request interval.

[0069] - Third Embodiment - Referring to FIG. 9, a third embodiment of the transmission system will be described. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the differences will be mainly described. Points not particularly described are the same as those in the first embodiment. In this embodiment, it is mainly different from the first embodiment in that the tables used for encoding and decoding are updated.

[0070] Figure 9 is an overall configuration diagram of the transmission system S3 in the third embodiment. In addition to the configuration of the first embodiment, the management device M in this embodiment includes an update unit 21 and a storage unit 22. The storage unit 22 stores the battery data decoded by the decoding unit 17. In this embodiment, the decoding unit 17 may output the battery data obtained by decoding not only to the battery controller 19 but also to the storage unit 22, or the battery controller 19 may store the battery data acquired from the decoding unit 17 in the storage unit 22. Also, in this embodiment, the encoding unit 16 and the decoding unit 17 perform encoding and decoding using the same encoding table.

[0071] When the vehicle equipped with the transmission system S3 is stopped, the update unit 21 creates a more efficient encoding table using the past battery data stored in the storage unit 22. For example, the encoding table is updated so that data with a higher occurrence frequency can be represented with fewer bytes. The update unit 21 stores the created encoding table in the decoding unit 17. The update unit 21 further causes the created encoding table to be transmitted to the battery data transmission device B for use by the transmission control unit 15-z. The battery data transmission device B that receives this updates the encoding table stored in the encoding unit 16 with the received encoding table.

[0072] According to the third embodiment described above, the following operational effects can be obtained. (9) The management device M includes a decoding unit 17 that decodes encoded data using an encoding table to obtain battery data, a storage unit 22 that accumulates the battery data, and an update unit 21 that updates the encoding table using the battery data accumulated in the storage unit 22. The transmission control unit 15-z sends the encoding table updated by the update unit 21 to the battery data transmission device B. Therefore, the efficiency of encoding can be improved using actual data.

[0073] - Fourth Embodiment - Referring to FIG. 10, a fourth embodiment of the transmission system will be described. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the differences will be mainly described. For points not particularly described, they are the same as those in the first embodiment. In this embodiment, it is different from the first embodiment mainly in that the abnormality detection unit is provided in both the management device and the battery data transmission device.

[0074] FIG. 10 is an overall configuration diagram of the transmission system S4 in the fourth embodiment. The transmission system S4 combines the management device M in the first embodiment and the battery data transmission device B in the second embodiment. The transmission system S4 in this embodiment may operate in the same manner as the transmission system S1 in the first embodiment, or may operate in the same manner as the transmission system S2 in the second embodiment.

[0075] In each of the above-described embodiments and modification examples, the configuration of the functional blocks is merely an example. Some functional configurations shown as separate functional blocks may be integrally configured, or the configuration represented by one functional block diagram may be divided into two or more functions. Also, a configuration may be adopted in which a part of the functions of each functional block is provided in other functional blocks.

[0076] The above-described embodiments and modification examples may be combined with each other. Although various embodiments and modification examples have been described above, the present invention is not limited to these contents. Other aspects conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention.

Description of Reference Numerals

[0077] 14 Cell controller 15 Transmission control unit 16 Encoding unit 17 Decoding unit 18 Abnormality detection unit 19 Battery controller B Battery data transmission device M Management device S1~S4 Transmission system T transmission path

Claims

1. A transmission control unit that communicates with a battery data transmission device that transmits encoded data obtained by encoding battery data, which is data related to a battery, via a transmission line; An abnormality detection unit that detects an abnormality in the transmission line; A command unit that outputs a command to shorten the data length of the encoded data to the battery data transmission device when the abnormality detection unit detects an abnormality in the transmission line, comprising: A decoding unit that decodes the encoded data using an encoding table to obtain the battery data; A storage unit that stores the battery data; An update unit that updates the encoding table using the battery data stored in the storage unit, further comprising: The transmission control unit is a management device that sends the encoding table updated by the update unit to the battery data transmission device.

2. An encoding unit that generates encoded data obtained by encoding battery data, which is data related to a battery; A transmission control unit that transmits the encoded data to a management device via a transmission line; An abnormality detection unit that detects an abnormality in the transmission line, comprising: The encoding unit has at least a first mode and a second mode as operation modes; The encoded data in the second mode has a shorter data length than the encoded data in the first mode; When the abnormality detection unit detects an abnormality in the transmission line, the abnormality detection unit causes the encoding unit to apply the second mode; Further comprising a cell controller that acquires information from the battery; The abnormality detection unit further detects an abnormality in the battery using the information acquired by the cell controller; The abnormality detection unit is a battery data transmission device that causes the encoding unit to apply the second mode when the abnormality detection unit detects an abnormality in the transmission line or the battery.

3. A transmission system including a battery data transmission device that transmits encoded data obtained by encoding battery data, which is data related to a battery, via a transmission line, and a management device that receives the encoded data, comprising: An abnormality detection unit that detects an abnormality in the transmission line; The battery data transmission device: An encoding unit that generates the encoded data using the battery data; A transmission control unit that transmits the encoded data to the management device via the transmission line, comprising: The encoding unit has at least a first mode and a second mode as operation modes; The encoded data in the second mode has a shorter data length than the encoded data in the first mode. When the abnormality detection unit detects an abnormality in the transmission line, the abnormality detection unit causes the encoding unit to apply the second mode. The battery data transmission device further includes a cell controller that acquires information from the battery. The abnormality detection unit further detects an abnormality in the battery using the information acquired by the cell controller. The transmission system in which, when the abnormality detection unit detects an abnormality in the transmission line or the battery, the abnormality detection unit causes the encoding unit to apply the second mode.

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