Battery monitoring system, battery monitoring device, and voltage measurement device

Abstract

To provide a battery monitoring system, a battery monitoring device, and a voltage measurement device that can reduce a synchronization shift in measurement timing.SOLUTION: A battery monitoring system according to an embodiment includes: a current measurement device that measures a current in a battery to output a current value; a voltage measurement circuit that measures a voltage in the battery; a first microcomputer that controls the voltage measurement circuit; a voltage measurement device including a first wireless communication unit that wirelessly outputs a measured voltage value; a second wireless communication unit that wirelessly communicates with the first wireless communication unit; and a battery monitoring device including a second microcomputer that receives the current value and the voltage value. The second microcomputer outputs a current measurement request signal to the current measurement device after the lapse of a first time based on an output signal from the second wireless communication unit. The first microcomputer exerts control such that the voltage measurement circuit measures the voltage after the lapse of a second time synchronized with the first time based on an output signal from the first wireless communication unit.SELECTED DRAWING: Figure 2B

Description

[Technical Field]

[0001] The present invention relates to a battery monitoring system, a battery monitoring device, and a voltage measuring device. [Background technology]

[0002] Conventionally, there is a battery monitoring system that includes multiple slave units that measure battery voltages and a master unit that is connected to each slave unit via wireless communication and monitors the battery status (see, for example, Patent Document 1). The master unit determines the battery's degradation state, etc., based on the voltage received from each slave unit and the battery current measured by a current sensor.

[0003] Furthermore, Patent Document 1 discloses a technology for synchronizing the timing of voltage and current measurement between a slave unit and a master unit by transmitting time information managed by the slave unit to the master unit, and the master unit then synchronizing the timing of current measurement with the timing of voltage measurement of the slave unit based on the time information. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-062772 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional technology, each device performs processes before and after communication, such as the process in which the slave device adds time information to communication data and the process in which the master device analyzes communication data received. These processes can have variations in processing time. This variation in processing time can cause an error between the slave device's predicted voltage measurement timing and the actual voltage measurement timing. In this case, even if the master device synchronizes the current measurement timing based on the predicted voltage measurement timing, a synchronization error occurs with respect to the actual voltage measurement timing.

[0006] The present invention has been made in view of the above, and has an object to provide a battery monitoring system, a battery monitoring device, and a voltage measuring device that can reduce deviations in synchronization of measurement timing. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the battery monitoring system of the present invention includes a current measurement device that measures a battery current and outputs the current value, a voltage measurement circuit that measures a battery voltage, a first microcomputer that controls the voltage measurement circuit, a voltage measurement device including a first wireless communication unit that wirelessly outputs the measured voltage value, a second wireless communication unit that wirelessly communicates with the first wireless communication unit, and a battery monitoring device including a second microcomputer to which the current value and the voltage value are input. The second microcomputer outputs a current measurement request signal to the current measurement device after a first time has elapsed based on an output signal from the second wireless communication unit. The first microcomputer controls the voltage measurement circuit to measure the voltage after a second time has elapsed that is synchronized with the first time, based on the output signal from the first wireless communication unit. [Effects of the Invention]

[0008] According to the present invention, by setting the measurement timing of each device based on the timing of communication between the measurement device and the battery monitoring device, it is possible to reduce the amount of processing performed before and after communication and eliminate the influence of time caused by these processing. Therefore, according to the present invention, it is possible to reduce synchronization errors in the measurement timing of voltage and current. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a battery monitoring system according to an embodiment. [Figure 2A] FIG. 2A is a diagram illustrating an example of the operation of the battery monitoring system according to the embodiment. [Figure 2B] FIG. 2B is a diagram illustrating an example of the operation of the battery monitoring system according to the embodiment. [Figure 3] FIG. 3 is a timing chart showing the processing timing of the measurement timing synchronization process. [Figure 4] FIG. 4 is a timing chart showing the processing timing of the battery monitoring system. [Figure 5] FIG. 5 is a timing chart showing another example of the measurement timing synchronization process. [Figure 6] FIG. 6 is a flowchart showing the procedure of the process executed by the battery monitoring device. [Figure 7] FIG. 7 is a flowchart showing the procedure of the process executed by the measurement device. [Figure 8] FIG. 8 is a diagram illustrating an example of the configuration of a battery monitoring system according to a modified example. [Figure 9] FIG. 9 is a diagram illustrating an example of the configuration of a battery monitoring system according to a modified example. [Figure 10] FIG. 10 is a flowchart showing the procedure of processing executed by the TCU according to the modified example. [Figure 11] FIG. 11 is a flowchart showing the procedure of processing executed by a battery monitoring device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a battery monitoring system, a battery monitoring device, and a measuring device according to embodiments will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following embodiments. In the following, the term "predetermined" can be read as "predetermined."

[0011] First, an overview of a battery monitoring system according to an embodiment will be described using Figures 1, 2A, and 2B. Figure 1 is a block diagram showing an example of the configuration of a battery monitoring system S according to an embodiment. Figures 2A and 2B are diagrams showing an example of the operation of the battery monitoring system S according to an embodiment. A battery monitoring method according to an embodiment is executed by the battery monitoring system S.

[0012] The battery monitoring system S according to the embodiment is a system for monitoring the state of a battery (e.g., a lithium-ion battery) for driving a vehicle mounted on, for example, an electric vehicle or a hybrid vehicle. For example, the battery monitoring system S monitors the deterioration state of the battery. Note that the battery monitoring system S may be configured to monitor the state of any battery other than a vehicle battery.

[0013] As shown in Fig. 1, the battery monitoring system S includes a battery monitoring device 1, multiple measuring devices 10a, 10b, and 10c, a battery 50, and a current sensor 100. The battery monitoring system S calculates the cell resistance of the battery 50 from voltage information indicating the voltage output from the battery 50, which is made up of multiple cells 51a, 51b, and 51c connected in series, and current information indicating the current flowing through the battery 50, and monitors the deterioration state of the battery 50 based on the resistance value of the cell resistance. Note that, hereinafter, unless otherwise distinguished, the multiple measuring devices 10a, 10b, and 10c will be collectively referred to as multiple measuring devices 10. Furthermore, unless otherwise distinguished, the multiple cells 51a, 51b, and 51c will be collectively referred to as multiple cells 51.

[0014] The plurality of measuring devices 10 are voltage measuring devices that are connected to each of the plurality of cells 51 that make up the battery 50, and measure the voltage of each of the plurality of cells 51 (hereinafter referred to as cell voltage) according to a voltage measurement command from the battery monitoring device 1.

[0015] Specifically, the measurement device 10a measures the cell voltage of the cell 51a, the measurement device 10b measures the cell voltage of the cell 51b, and the measurement device 10c measures the cell voltage of the cell 51c.

[0016] The battery monitoring device 1 is connected to each of the multiple measuring devices 10 via, for example, time-division wireless communication so that it can communicate with them, and acquires voltage information indicating cell voltages from each of the multiple measuring devices 10. Specifically, the battery monitoring device 1 communicates with each of the multiple measuring devices 10 sequentially via wireless communication within a communication cycle. In other words, the battery monitoring device 1 is connected to the multiple measuring devices 10 via a unicast method, in which the communication cycle is time-divided and the battery monitoring device 1 communicates with each of the multiple measuring devices 10 one-to-one sequentially within a predetermined time. The communication cycle is set to a period that allows the battery monitoring device 1 to complete communication with all of the measuring devices 10 with ample time to spare if communication is performed normally.

[0017] The current sensor 100 is a current measurement device that measures the current flowing through the battery 50. The current sensor 100 may be provided in the battery monitoring device 1, or may be arranged external to the battery monitoring device 1 and transmit the measured current value to the battery monitoring device 1. In the following, an example will be described in which the current sensor 100 is arranged external to the battery monitoring device 1 and transmits the measured current value to the battery monitoring device 1 via a wired connection.

[0018] In such a configuration, the battery monitoring system S according to the embodiment utilizes communication between the battery monitoring devices 1 and the measuring devices 10 to synchronize the voltage measurement timing of the multiple measuring devices 10 and the current measurement timing of the battery monitoring device 1.

[0019] 2A and 2B, a description will be given of the measurement timing synchronization process of the battery monitoring system S according to the embodiment. For convenience of explanation, only one measuring device 10 is shown in Fig. 2A and 2B, but in reality, communication is performed with each of the multiple measuring devices 10 to synchronize the measurement timing.

[0020] First, before describing the measurement timing synchronization process, the functional configurations of the battery monitoring device 1 and the measurement device 10 will be described.

[0021] 2, the battery monitoring device 1 includes a communication unit 2, a controller 3, and a storage unit (not shown). The measuring device 10 includes a communication unit 20, a controller 30, and a storage unit (not shown).

[0022] The communication unit 2 is, for example, a communication IC (Integrated Circuit) equipped with a BLE (abbreviation for Bluetooth Low Energy; Bluetooth is a registered trademark) communication function. The communication unit 2 communicates sequentially with each of the multiple measuring devices 10 one-to-one using time-division wireless communication within a communication cycle. In other words, the communication unit 2 performs wireless communication using a unicast method. The communication unit 2 also performs wired communication with the controller 3 using, for example, SPI (abbreviation for Serial Peripheral Interface) communication.

[0023] The storage unit of the battery monitoring device 1 is, for example, a RAM (Random Access Memory) or a data flash. Such storage unit can store voltage information acquired from the measuring device 10, current information acquired from the current sensor 100, information on various programs, etc. The battery monitoring device 1 may also acquire the above-mentioned programs and various information via another computer or portable recording medium connected via a wired or wireless network.

[0024] The controller 3 includes a microcomputer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM, etc., and various other circuits. The controller 3 controls the overall operation of the battery monitoring device 1 by having the CPU execute a program stored in the ROM using the RAM as a working area. Note that the controller 3 may be partially or entirely configured with hardware such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array).

[0025] The communication unit 20 is, for example, a communication IC equipped with a BLE communication function. The communication unit 20 communicates with the battery monitoring device 1 one-to-one via time-division wireless communication within a communication cycle. That is, the communication unit 20 performs wireless communication using a unicast method. The communication unit 20 also performs wired communication with the controller 30 using, for example, SPI communication.

[0026] The storage unit of the measuring device 10 is, for example, a RAM or a data flash. Such a storage unit can store measured voltage information, information on various programs, etc. The measuring device 10 may also acquire the above-mentioned programs and various information via another computer or portable recording medium connected via a wired or wireless network.

[0027] The controller 30 includes a microcomputer having a CPU, ROM, RAM, etc., and various circuits. The controller 30 controls the overall operation of the measuring device 10 by having the CPU execute a program stored in the ROM using the RAM as a work area. Note that the controller 30 may be partially or entirely configured with hardware such as an ASIC or FPGA.

[0028] Next, the measurement timing synchronization process will be described.

[0029] In the present disclosure, the battery monitoring device 1 and the measuring device 10 each synchronize the timing of measuring the current and voltage based on an output signal that is output in conjunction with communication.

[0030] 2A, the communication unit 2 transmits communication data including a voltage measurement command generated by the controller 3 to the communication unit 20 (step S1). Specifically, the communication unit 2 amplifies the power of the communication data using a power amplifier circuit (first circuit) not shown, and transmits the amplified communication data to the communication unit 20. In the following, the power amplifier circuit will be referred to as PA.

[0031] At this time, the communication unit 2 outputs a first output signal indicating that the PA is operating to the controller 3 (step S2). That is, the communication unit 2 outputs a first output signal linked to the transmission of communication data. More specifically, the communication unit 2 outputs a first output signal indicating the start of transmission of communication data.

[0032] Then, when the controller 3 receives the first output signal, it measures the current using the current sensor 100 at a first timing set based on the first output signal (step S3). Specifically, the controller 3 sets the first timing to be the timing when a predetermined first set time has elapsed since the timing at which the first output signal was received. Note that this first set time is a standby time for synchronizing with the voltage measurement timing (second timing) of the measuring device 10, which will be described later.

[0033] Next, the communication unit 20 of the measuring device 10 receives the communication data transmitted by the communication unit 2 of the battery monitoring device 1 (step S11). Specifically, the communication unit 20 amplifies the signal of the received communication data using an amplifier circuit (low noise amplifier, second circuit) not shown. Note that, hereinafter, the amplifier circuit will be referred to as an LNA.

[0034] At this time, the communication unit 20 outputs a second output signal indicating that the LNA is operating to the controller 30 (step S12). That is, the communication unit 20 outputs a second output signal linked to the reception of communication data. More specifically, the communication unit 20 outputs a second output signal indicating the start of reception of communication data.

[0035] When the controller 30 receives the second output signal, it measures the cell voltage using a measurement circuit (not shown) at the second timing set based on the second output signal (step S13). Specifically, the controller 30 sets the second timing to the timing when a predetermined second set time has elapsed since the timing at which the second output signal was received. Note that this second set time is a standby time for synchronizing with the current measurement timing (first timing) of the battery monitoring device 1 described above. More specifically, the second set time is the first set time adjusted by the difference between the transmission timing and the reception timing in communication. Note that this timing difference is usually approximately constant (i.e., the difference between the transmission and reception timing is constant) because the communication time is managed by time-division communication.

[0036] As described above, the present disclosure focuses on the fact that the timing difference between transmission and reception during communication is constant, and sets the first and second set times to compensate for this timing difference based on an output signal linked to transmission and reception. In other words, the present disclosure sets the measurement timing based on an output signal indicating the timing of communication between the measurement device 10 and the battery monitoring device 1. In other words, the present disclosure does not require additional processing for time synchronization (mainly software processing), such as transmitting time information managed by one device to the other device, in order to achieve time synchronization. This eliminates the influence of processing performed by each device before and after communication (mainly additional processing for time synchronization), thereby reducing synchronization errors in the measurement timing of voltage and current.

[0037] Furthermore, in the present disclosure, by outputting an output signal that serves as a reference for measurement timing from a circuit (hardware) that operates during transmission and reception, such as a PA or LNA, it is possible to eliminate the influence of variations in processing time that would occur if output of the output signal were processed by software. In other words, according to the present disclosure, by outputting an output signal from a circuit, it is possible to further reduce synchronization deviations in measurement timing.

[0038] Next, the battery monitoring system S will be described in more detail using Fig. 2B. As shown in Fig. 2B, the battery monitoring device 1 includes a wireless communication unit 2 (second wireless communication unit) which is a communication section 2, and a main microcomputer 3 (second microcomputer) which is a controller 3. The measuring device 10 includes a wireless communication unit 20 (first wireless communication unit) which is a communication section 20, and a monitoring IC (Integrated Circuit) 40 (voltage measurement circuit).

[0039] The wireless communication unit 2 performs wireless communication with the wireless communication unit 20 of the measuring device 10. The wireless communication unit 2 includes a wireless microcomputer 2a and a transmission / reception circuit 2b. The wireless microcomputer 2a controls wireless communication with the wireless communication unit 20 of the measuring device 10. The transmission / reception circuit 2b includes a power amplifier circuit (PA) that operates during transmission and an amplifier circuit (LNA) that operates during reception. Note that while FIG. 2B shows an example in which the transmission / reception circuit 2b is disposed outside the wireless microcomputer 2a, it may also be built into the wireless microcomputer 2a.

[0040] The main microcomputer 3 controls the overall operation of the battery monitoring device 1. Specifically, the main microcomputer 3 executes the above-described operation of the controller 3.

[0041] The wireless communication unit 20 functions as a communication unit 20 that performs wireless communication with the wireless communication unit 20 of the measuring device 10, and as a controller 30 that controls the overall operation of the measuring device 10. The wireless communication unit 20 includes a wireless microcomputer 20a and a transmission / reception circuit 20b. The wireless microcomputer 20a functions as the communication unit 20 that performs wireless communication with the wireless communication unit 20 of the measuring device 10, and as the controller 30 that controls the overall operation of the measuring device 10. The transmission / reception circuit 20b includes a power amplifier circuit (PA) that operates during transmission, and an amplifier circuit (LNA) that operates during reception. While FIG. 2B shows an example in which the transmission / reception circuit 20b is disposed external to the wireless microcomputer 20a, it may also be built into the wireless microcomputer 20a.

[0042] The monitoring IC 40 is a voltage measurement circuit that measures the voltage of the cell 51 in response to a voltage measurement instruction from the wireless microcomputer 20a.

[0043] In the configuration shown in FIG. 2B, a process for synchronizing the measurement timing of current and voltage will be described.

[0044] First, the main microcomputer 3 outputs a voltage measurement command to the wireless microcomputer 2a, instructing the wireless microcomputer 2a to transmit the voltage measurement command. Upon receiving the voltage measurement command, the wireless microcomputer 2a activates the PA in the transmission / reception circuit 2b to transmit the voltage measurement command to the measuring device 10. The transmission / reception circuit 2b inputs an enable signal (first output signal) indicating that the PA is operating at the time of transmission as an interrupt signal to the main microcomputer 3. Note that, in a later stage, the enable signal indicating that the PA is operating may be referred to as PA enable. By receiving PA enable as an interrupt signal, the main microcomputer 3 can detect without delay that the voltage measurement command has been transmitted to the measuring device 10.

[0045] Next, the wireless microcomputer 20a of the measuring device 10 operates the LNA of the transmitting / receiving circuit 20b to receive the voltage measurement command transmitted from the battery monitoring device 1. Upon reception, the transmitting / receiving circuit 20b inputs an enable signal (second output signal) indicating that the LNA is operating to the wireless microcomputer 20a as an interrupt signal. Note that, in a subsequent stage, the enable signal indicating that the LNA is operating may be referred to as an LNA enable. By receiving the LNA enable as an interrupt signal, the wireless microcomputer 20a can detect without delay that it has received the voltage measurement command from the battery monitoring device 1.

[0046] The battery monitoring device 1 and the measuring device 10 then determine the timing for measuring the current and voltage based on their respective enable signals, and measure the current and voltage at the determined measurement timing. Specifically, the main microcomputer 3 of the battery monitoring device 1 outputs a current measurement request signal to the current sensor 100 at a first timing set based on PA enable, and the current sensor 100 measures the current. Furthermore, the wireless microcomputer 20a of the measuring device 10 outputs a voltage measurement request signal to the monitoring IC 40 at a second timing set based on LNA enable, and the monitoring IC 40 measures the cell voltage.

[0047] Next, the synchronization process of measurement timing will be described in more detail using FIG. 3. FIG. 3 is a timing chart showing the processing timing of the synchronization process of measurement timing. FIG. 3 shows a timing chart within one communication cycle (nth cycle) (from time t1 to time t9). Note that FIG. 3 shows one measuring device 10 (communication unit 20 and controller 30), but in reality, the voltage measurement timing and current measurement timing of all of the multiple measuring devices 10 are synchronized within one communication cycle. In other words, after processing with one measuring device 10 shown in FIG. 3, processing with the other measuring devices 10 is performed sequentially within one communication cycle (n cycle). Also, in FIG. 3, two communications are performed between the battery monitoring device 1 and one measuring device 10 within one communication cycle: transmission of a voltage measurement command from the battery monitoring device 1 to the measuring device 10, and transmission of voltage data from the measuring device 10 to the battery monitoring device 1.

[0048] Specifically, first, at time t1, which is the start of the communication cycle, the controller 3 generates and outputs a voltage measurement command and instructs the communication unit 2 to transmit the voltage measurement command. Then, when the communication unit 2 determines that time t3, which is a predetermined time after the start time t1 of the communication cycle and is the transmission timing in time-division communication, has arrived, it activates the PA and starts the transmission process of communication data including the voltage measurement command. At this time, the communication unit 2 outputs PA enable (first output signal) to the controller 3, indicating that the PA operation has started. More specifically, PA enable is output to the controller 3 by the operation of a circuit (hardware) such as the PA. When the controller 3 receives the input of PA enable, it starts counting on a timer. More specifically, when the controller 3 receives the input of PA enable, it generates an interrupt process and starts counting on a timer.

[0049] Furthermore, when the communication unit 20 determines that time t2 in the time-division communication, which is a predetermined time after the start time t1 of the communication cycle (a time that precedes the transmission timing at time t3 by a predetermined period D1), has arrived, it activates the LNA and starts receiving the communication data. In other words, the communication unit 20 activates the LNA in advance to prepare so that no communication data is missed. This is because the battery monitoring device 1, not the measuring device 10, manages the time of the time-division communication in the communication cycle, and this is to allow for an error in the time referenced by the battery monitoring device 1 and the measuring device 10. This time error is a constant value because it depends on the characteristics of each device. For this reason, the predetermined period D1 is set to a predetermined value (fixed value) based on the constant value. In other words, the predetermined period D1 corresponds to the time difference between the start timing of the transmission and reception processing (operation of the transmission and reception circuits) of the receiving device and the transmitting device. In other words, it corresponds to the time difference between the output timing of the enable signals output from the transmitting device and the receiving device.

[0050] At time t2, the communication unit 20 outputs LNA enable (second output signal) indicating that the LNA operation has started to the controller 30. More specifically, LNA enable is output to the controller 30 by operation of a circuit (hardware) such as the LNA. When the controller 30 receives input of LNA enable, it starts counting on a timer. More specifically, when LNA enable is input, the controller 30 generates an interrupt process and starts counting on a timer.

[0051] Next, after completing transmission at time t4, a predetermined period D2 after time t3, the communication unit 2 stops the PA and operates the LNA, thereby preparing to receive communication data transmitted from the measuring device 10. Note that while Fig. 3 shows an example in which the PA is immediately switched to the LNA, the LNA may be operated a predetermined time after the PA is stopped, depending on the transmission timing of the measuring device 10. Furthermore, if the predetermined period D2 is outside the normal time range, the controller 3 stops the timer (stops the current measurement process), and this point will be described in detail later with reference to Fig. 4.

[0052] Next, the communication unit 20 stops the LNA at time t5, a predetermined time after time t4, which is the timing when the communication unit 2 completes transmission. This is for the same reason as the start of LNA operation (time t2) described above, that is, to prevent communication data from being missed. Note that if the predetermined period D3 during which the LNA is operating is outside the normal time range, the controller 30 stops the timer (stops the voltage measurement process), and this point will be described in detail later with reference to FIG.

[0053] Next, at time t5, the communication unit 20 activates the PA to start the process of transmitting communication data to the communication unit 2. In this transmission process, the voltage data of the cell voltage measured by the controller 30 in the previous communication cycle (the n-1th cycle: the first communication cycle) is transmitted as communication data in the current communication cycle, which is the next communication cycle (the nth cycle: the second communication cycle). Then, at time t6, a predetermined period after time t5, the communication unit 20 stops the PA when transmission of the communication data is completed. Furthermore, the communication unit 2 stops the LNA at time t7, a predetermined period after time t6, which is the timing when the communication unit 20 completes transmission.

[0054] Then, the controller 3 measures the current at time t8, which is the timing (first timing) when a first set time D4 has elapsed since time t3 when the timer started counting. Specifically, the controller 3 generates a timer interrupt process at the timing when the first set time D4 has elapsed, and measures the current. Furthermore, the controller 30 measures the cell voltage at time t8, which is the timing (second timing) when a second set time D5 has elapsed since time t2 when the timer started counting. Specifically, the controller 30 generates a timer interrupt process at the timing when the second set time D5 has elapsed, and measures the cell voltage. Note that the second set time D5 is the first set time D4 plus a predetermined period D1. This allows the controllers 3 and 30 to synchronize the timing of measuring the current and voltage (cell voltage).

[0055] Before time t8 at which the current and voltage are measured, the battery monitoring device 1 and the measuring device 10 determine whether a voltage measurement command has been transmitted or received. Specifically, the controller 3 of the battery monitoring device 1 measures the current when it transmits a voltage measurement command and receives PA enable. The controller 30 of the measuring device 10 measures the voltage when it receives a voltage measurement command and LNA enable. When the current and voltage measurements are completed, history information indicating that a voltage measurement command has been transmitted or received is reset.

[0056] Then, the controller 3 determines the state of the battery 50 based on the current measured at a first timing in the first communication cycle (the n-1th cycle), which is the previous communication cycle, and the voltage (the voltage measured in the first communication cycle) received from the measuring device 10 in the second communication cycle (the nth cycle), which is the current communication cycle. As a result, even if the controller 3 receives voltage data in the next communication cycle, it can determine the state of the battery 50 based on the combination of the current and voltage measured in the same communication cycle.

[0057] Furthermore, the battery monitoring system S can set the timer start point early within the communication cycle by outputting the first output signal in conjunction with the start of transmission by the communication unit 2 and outputting the second output signal in conjunction with the start of reception by the communication unit 20. In other words, the timer is started at an early timing after the start of the communication cycle, not after other processing has been performed, so that the error in the time until the timer is started can be minimized.

[0058] The battery monitoring system S may be configured to output the first output signal in conjunction with the start of reception by the communication unit 2 (time t4), and the second output signal in conjunction with the start of transmission by the communication unit 20 (time t5). This allows the set times D4 and D5 from the start of timer counting to the measurement timing to be shortened, thereby minimizing the impact of timer accuracy errors. In this case, the predetermined periods D2 and D3 are constant times (fixed values).

[0059] 3, the voltage measurement command is generated (output) from the controller 3 at the same timing as the start of the communication cycle, i.e., at time t1, but it does not have to be the same timing. The timing at which the voltage measurement command is generated (output) may be later than the start timing of the communication cycle (time t1) or earlier than the start timing of the communication cycle (i.e., it may be in the previous communication cycle).

[0060] Furthermore, the timing at which the controller 3 outputs the voltage measurement command does not have to be synchronized with the communication cycle. That is, the controller 3 may output the voltage measurement command regardless of the communication cycle, and the communication unit 2 may transmit the voltage measurement command at a predetermined timing (time t3) in the communication cycle after the voltage measurement command is output. In this case, it is more preferable that the transmission timing of the voltage measurement command be the predetermined timing (time t3) in the communication cycle that occurs earliest after the voltage measurement command is output.

[0061] Furthermore, if it is possible to communicate with the same measuring device 10 multiple times within one communication cycle, the voltage measurement command does not necessarily have to be sent in the first (first) communication after the start of the communication cycle, but may be sent in the second or subsequent communication within the communication cycle. Even when sending a voltage measurement command in the second or subsequent communication, the predetermined period D1 is fixed, so the timing of measuring the voltage and current can be synchronized in the same way as when sending a voltage measurement command in the first communication.

[0062] 3, the length of the period (time difference) between the PA enable output end time (time t4) and the LNA enable output end time (time t5) is preferably shorter than the length of the period (time difference, predetermined period D1) between the PA enable output start time (time t3) and the LNA enable output start time (time t2). This is because, in battery monitoring, while information related to battery monitoring is expected to be transmitted and received with high reliability (without missing transmissions or receptions), it is more difficult for the receiving side to predict the transmission time of the transmitting side than for the transmitting side. On the other hand, the receiving side can predict the transmission time of communication data (predetermined period D2) to a certain extent, i.e., the timing of the transmission end is predictable. Therefore, by utilizing this characteristic, the receiving side can set the end (time t5) of the LNA enable signal to be closer to the end (time t4) of the PA enable signal than the start (time t2). The reason why the end time (time t5) is more predictable is that the communication volume (such as the voltage measurement command and the battery information in the response) is known by design. In other words, compared to the start time, the timing of which is unknown, the end time can be calculated backward from the start time, making it easier to predict.

[0063] Next, processing when the battery monitoring device 1 does not transmit a voltage measurement command to the measuring device 10 will be described with reference to Fig. 4. Fig. 4 is a timing chart showing processing timings of the battery monitoring system S. Note that in Fig. 4, explanations of processing contents that are the same as those in Fig. 3 will be omitted.

[0064] As shown in Figure 4, at time t1, which is the start of the communication cycle, the controller 3 performs other processing without generating a voltage measurement command. Even in this case, the communication unit 2 activates the PA at time t3, which is the transmission timing in time-division communication, to start the transmission processing of the communication data. Note that in Figure 4, the communication data is assumed to be empty (null). In other words, the communication data contains only a header.

[0065] In this case, because the amount of communication data transmitted by the communication unit 2 is small, the predetermined period D2 (the period from time t3 to time t4) during which the transmission process is performed is shorter than that for communication data including a voltage measurement command. Therefore, the predetermined period D2 (predetermined period D2 in FIG. 3) for transmitting communication data including a voltage measurement command is set as the normal time range. If the predetermined period D2 (predetermined period D2 in FIG. 4) falls outside the normal time range (predetermined period D2 in FIG. 3), the controller 3 determines that the voltage measurement command is not included and stops counting the timer. In other words, the controller 3 stops the current measurement process for the current communication cycle (the nth cycle). Note that the "normal time range" here does not mean a time range for detecting abnormal (abnormal) communication, but a time range for detecting communication intended to measure current and voltage. In other words, the normal time range is a threshold (range) for determining whether communication is intended to measure current and voltage.

[0066] Similarly, on the communication unit 20 side, since the amount of communication data received is small (the transmission processing time is short), the predetermined period D3 (the period from time t2 to time t5) for performing the reception processing is shorter than that for communication data including a voltage measurement command. Therefore, the predetermined period D3 (predetermined period D3 in FIG. 3) for receiving communication data including a voltage measurement command is set to the normal time range. Then, if the predetermined period D3 (predetermined period D3 in FIG. 4) falls outside the normal time range (predetermined period D3 in FIG. 3), the controller 30 determines that the voltage measurement command is not included and stops counting the timer. In other words, the controller 30 stops the voltage measurement processing in the current communication cycle (the nth cycle). In this way, the battery monitoring system S can accurately avoid performing unnecessary current and voltage measurement processing by determining whether or not the communication data contains a voltage measurement command after completing transmission and reception of the communication data. Furthermore, the battery monitoring system S can easily determine whether a voltage measurement command has been issued by judging the elapsed time of the transmission process (predetermined period D2) and the elapsed time of the reception process (predetermined period D3), thereby reducing the processing load on each controller. Furthermore, the battery monitoring system S does not measure voltage and current every time communication occurs, but rather measures only when a measurement command has been issued, thereby reducing unnecessary measurement processing and reducing the processing load.

[0067] The above-described processing of the battery monitoring system S is an example. For example, the battery monitoring system S may determine whether or not the communication data transmitted from the communication unit 2 to the communication unit 20 includes a voltage measurement command using a method other than the predetermined periods D2 and D3. This point will be described with reference to FIG. 5.

[0068] Fig. 5 is a timing chart showing another example of the measurement timing synchronization process. Note that in Fig. 5, the same processing content as in Fig. 3 will not be described.

[0069] 5, the communication unit 2 notifies the controller 3 of data information indicating the contents of the data to be transmitted at time t3 when the communication unit 2 transmits the communication data to the communication unit 20. The notification may be made via an interface such as serial communication, for example.

[0070] At time t3, the controller 3 starts counting the timer and analyzes the contents of the transmission data notified by the communication unit 2 to determine whether the transmission data includes a voltage measurement command. If the transmission data includes a voltage measurement command, the controller 3 continues the timer. If the transmission data includes a voltage measurement command, the controller 3 measures the current at a first timing (time t8) when a first set time D4 has elapsed since the timer started counting. On the other hand, if the transmission data does not include a voltage measurement command, the controller 3 stops the timer, thereby stopping the current measurement process. Note that the controller 3 may start the timer after confirming that the transmission data includes a voltage measurement command. This allows the controller 3 to accurately avoid a situation in which the measuring device 10 erroneously measures current when it is not actually measuring voltage.

[0071] Furthermore, at time t5 when reception of the communication data is completed, the controller 30 analyzes the received data and determines whether the received data includes a voltage measurement command. If the received data includes a voltage measurement command, the controller 30 continues the timer. If the received data does not include a voltage measurement command, the controller 30 stops the timer. Note that the controller 30 may also determine whether the received data includes a voltage measurement command at time t4 when transmission by the communication unit 2 is completed, in other words, when it is confirmed that no more communication data will be transmitted from the communication unit 2. This allows the controller 30 to accurately avoid a situation in which the controller 30 erroneously measures voltage even when a voltage measurement command has not been transmitted from the battery monitoring device 1. Furthermore, the battery monitoring system S does not measure voltage and current every time communication is received, but rather performs measurements only when a measurement command is received. This reduces unnecessary measurement processing and reduces the processing load.

[0072] Next, the processing procedures of the battery monitoring device 1 and the measuring device 10 will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is a flowchart showing the processing procedures executed by the battery monitoring device 1. Fig. 7 is a flowchart showing the processing procedures executed by the measuring device 10. Figs. 6 and 7 show the processing procedures for transmitting a voltage measurement command from the battery monitoring device 1 to the measuring device 10.

[0073] First, a description will be given of the processing procedure of the battery monitoring device 1 (controller 3) shown in Fig. 6. The controller 3 is the main processor of each processing step in Fig. 6.

[0074] First, the controller 3 generates a voltage measurement command at the beginning of a communication cycle (step S101). Next, the controller 3 detects the start of output of PA enable, which indicates that the PA has operated, during transmission from the communication unit 2 (step S102).

[0075] Next, the controller 3 starts counting the timer at the timing when the input of PA enable is received (step S103). Next, the controller 3 detects the end of output of PA enable in response to the completion of transmission by the communication unit 2 (step S104).

[0076] Next, the controller 3 determines whether the elapsed time from the start to the end of the transmission of the communication data (predetermined period D2 shown in FIG. 3) is within the normal time range (step S105). If the elapsed time is within the normal time range (step S105: Yes), the controller 3 determines whether the ongoing timer has elapsed the first set time D4 (step S106). If the elapsed time is outside the normal time range (step S105: No), the controller 3 cancels the timer (step S108) and ends the process.

[0077] If the ongoing timer has passed the first set time D4 (step S106: Yes), the controller 3 measures the current at the first timing when the first set time D4 has passed (step S107) and ends the process. Note that if the timer has not passed the first set time D4 (step S106: No), the controller 3 repeatedly executes step S106 until the timer has passed the first set time D4.

[0078] Next, a description will be given of the processing procedure of the measuring device 10 (controller 30) shown in Fig. 7. The controller 30 is the main processor of each processing step in Fig. 7.

[0079] First, the controller 30 detects the start of output of LNA enable, which indicates that the LNA is operating, when the communication unit 20 receives a signal (step S201).

[0080] Next, the controller 30 starts counting the timer at the timing when it receives the input of LNA enable (step S202). Next, the controller 30 detects the end of output of LNA enable in response to the completion of reception by the communication unit 20 (step S203).

[0081] Next, the controller 30 determines whether the elapsed time from the start to the end of reception of communication data (predetermined period D3 shown in FIG. 3) is within the normal time range (step S204). If the elapsed time is within the normal time range (step S204: Yes), the controller 30 determines whether the ongoing timer has elapsed a second set time D5 (step S205). Note that if the elapsed time is outside the normal time range (step S204: No), the controller 30 cancels the timer (step S207) and ends the process.

[0082] If the ongoing timer has passed the second set time D5 (step S205: Yes), the controller 30 measures the cell voltage at the second timing when the second set time D5 has passed (step S206) and ends the process. If the timer has not passed the second set time D5 (step S205: No), the controller 30 repeatedly executes step S205 until the timer has passed the second set time D5.

[0083] As described above, the battery monitoring system S according to the embodiment includes a current measurement device (current sensor 100) that measures the current of a battery 50 and outputs the current value, a voltage measurement circuit (monitoring IC 40) that measures the voltage of the battery 50, a first microcomputer (wireless microcomputer 20a) that controls the voltage measurement circuit, a measurement device 10 including a first wireless communication unit 20 that wirelessly outputs the measured voltage value, a second wireless communication unit 2 that wirelessly communicates with the first wireless communication unit 20, and a battery monitoring device 1 including a second microcomputer (main microcomputer 3) that receives inputs of the current value and the voltage value. The second microcomputer outputs a current measurement request signal to the current measurement device after a first time (predetermined period D4) based on an output signal from the second wireless communication unit 2. The first microcomputer controls the voltage measurement circuit to measure the voltage after a second time (predetermined period D5) synchronized with the first time has elapsed, based on the output signal from the first wireless communication unit 20.

[0084] According to the present disclosure, the measurement timing is set based on an output signal that indicates the timing of communication between the measuring device 10 and the battery monitoring device 1. This eliminates the influence of the processing performed by each device before and after communication, thereby reducing synchronization errors in the measurement timing of voltage and current.

[0085] Furthermore, in the present disclosure, by outputting an output signal that serves as a reference for measurement timing from a circuit such as a PA or LNA, it is possible to eliminate the influence of variations in processing time that would occur if output of the output signal were processed by software. In other words, according to the present disclosure, by outputting an output signal from a circuit, it is possible to further reduce synchronization deviations in measurement timing.

[0086] In the above-described embodiment, a configuration has been shown in which the battery monitoring device 1 transmits a voltage measurement command to the measuring device 10, but a configuration in which a current measurement command is transmitted from the measuring device 10 to the battery monitoring device 1 may also be used.

[0087] Furthermore, the synchronization adjustment process for the second time (predetermined period D5) obtained by synchronizing the first time (predetermined period D4) (by adding or subtracting the predetermined period D1) may be performed by storing the first time and the second time after synchronization adjustment in the product's memory before shipping the product, or by calculating and setting the time each time communication occurs during product operation. Whether the predetermined period D1 is added or subtracted in the synchronization adjustment depends on which device is the transmitting side. In the case of a pattern in which a voltage measurement command is sent from the battery monitoring device 1 to the measuring device 10 as shown in Figure 3, the synchronization adjustment is performed by adding the predetermined period D1.

[0088] In the above-described embodiment, an amplifier circuit such as a PA or an LNA is used as an example of a transceiver circuit that outputs an enable signal as an output signal, but a modulation circuit or a demodulation circuit may also be used as a circuit that outputs an output signal.

[0089] Furthermore, the communication units 2, 20 may further include a control unit (such as a microcomputer) that controls the transmission / reception circuit and exchanges data with the controllers 3, 30, in addition to a transmission / reception circuit that performs specific transmission / reception processing in wireless communication.

[0090] The above-described embodiment is merely an example, and the program of the battery monitoring device 1 may be updated through communication between an external server and the vehicle. This point will be described with reference to FIGS.

[0091] 8 and 9 are diagrams showing configuration examples of a battery monitoring system S according to a modified example.

[0092] 8, in a battery monitoring system S according to a modified example, an OTA (Over The Air) center 200 and a vehicle 210 are connected via a communication network N. The communication network N may be a wireless communication network such as 5G, LTE, or Wi-Fi (registered trademark).

[0093] The battery monitoring system S according to the modified example performs wireless communication between the OTA center 200 and the vehicle 210 to obtain update data for the battery monitoring device 1 and the measuring device 10 from the OTA center 200 and update programs, etc.

[0094] As shown in FIG. 9, in the battery monitoring system S, each vehicle 210 is provided with a TCU (Telematics Control Unit) 60 that receives update data from the OTA center 200.

[0095] The TCU 60 is an in-vehicle communication unit equipped with an antenna 61 for communicating with the OTA center 200 via the communication network N, and by connecting to the communication network N, communication is performed between the OTA center 200 and the vehicle 210.

[0096] Next, the flow of data update in the battery monitoring system S according to the modified example will be described.

[0097] When there is a program to be updated, the OTA center 200 transmits update data to the TCU 60 via the communication network N while the ignition switch of the vehicle 210 is on. The ignition switch is the power switch of the vehicle.

[0098] The TCU 60 transmits the update data received from the OTA center 200 to the communication unit 2 of the battery monitoring device 1 via the antenna 61. The TCU 60 also queries the OTA center 200 about an update and checks whether an update is available.

[0099] In Figure 9, a configuration is shown in which communication between the TCU 60 and the battery monitoring device 1 is performed via an antenna 61 for communication outside the vehicle and a communication unit 2 for wireless communication with the measuring device 10, but communication may also be performed via another communication device, for example, via a wired or wireless in-vehicle LAN (Local Area Network) that communicates between on-board devices such as the TCU 60 and the battery monitoring device 1.

[0100] The battery monitoring device 1 stores the update data received from the TCU 60 via the communication unit 2 in the storage unit. The update data is stored when the ignition switch is turned on. There are no particular restrictions on when the update data can be stored as long as the ignition switch is turned on, and it may be stored while the vehicle is running.

[0101] The battery monitoring device 1 is in an updatable state when all update data downloads via the TCU 60 are completed. When the ignition switch of the vehicle 210 is turned off, the controller 3 of the battery monitoring device 1 performs an update based on the update data stored in the storage unit.

[0102] In the modified example, the battery monitoring device 1 is automatically updated when the ignition switch is turned off. However, this is not limited to the above example. A driver or other occupant may be notified that the battery monitoring device 1 is in an updatable state, and the driver or other occupant may be asked whether or not to permit the update. After the driver or other occupant permits the update, the battery monitoring device 1 may be configured to be updated when the ignition switch is turned off.

[0103] A case will be described in which the present invention is applied to an example in which update data for the battery monitoring device 1 is acquired by wirelessly communicating between the OTA center 200 and the vehicle 210 and a program or the like is updated.

[0104] First, a basic embodiment of the present invention will be described, regardless of whether the update is performed using update data.

[0105] As described above, the multiple measuring devices 10 measure the cell state of each of the multiple cells 51 in accordance with a voltage measurement command from the battery monitoring device 1. The measuring device 10a measures the cell voltage of the cell 51a, the measuring device 10b measures the cell voltage of the cell 51b, and the measuring device 10c measures the cell voltage of the cell 51c.

[0106] The battery monitoring device 1 is communicably connected to each of the multiple measuring devices 10 by, for example, time-division wireless communication, and acquires state information indicating the cell state from each of the multiple measuring devices 10. Specifically, the battery monitoring device 1 communicates sequentially with each of the multiple measuring devices 10 by wireless communication within a communication cycle. In other words, the battery monitoring device 1 is communicatively connected by a unicast method, in which the communication cycle is time-divided and the battery monitoring device 1 communicates sequentially one-to-one with each of the multiple measuring devices 10 within a predetermined time.

[0107] Next, a description will be given of updating the battery monitoring device 1 based on update data from the OTA center 200. The update data corresponds to the battery monitoring program.

[0108] In the above-described embodiment, when the communication unit 2 of the battery monitoring device 1 transmits a voltage measurement command to each of the multiple measuring devices 10, it outputs a first output signal to the controller 3 in conjunction with the transmission. The controller 3 performs current measurement at a first timing set based on the first output signal. Furthermore, the communication unit 20 of the measuring device 10 outputs a second output signal to the controller 30 in conjunction with receiving a voltage measurement command from the battery monitoring device 1. The controller 30 performs voltage measurement at a second timing set based on the second output signal. In the above-described embodiment, it is assumed that a battery monitoring program performing such operations is pre-installed in the battery monitoring device 1 and the measuring device 10. However, the battery monitoring program may be installed later by updating based on update data from the OTA center 200.

[0109] For example, the update data from the OTA center 200 may include a battery monitoring program that, when the communication unit 2 transmits a voltage measurement command to each of the multiple measuring devices 10, outputs a first output signal to the controller 3 in conjunction with the transmission. The update data from the OTA center 200 may also include a battery monitoring program that causes the controller 3 to measure current at a first timing set based on the first output signal. The update data from the OTA center 200 may also include a battery monitoring program that causes the communication unit 20 to output a second output signal to the controller 30 in conjunction with receiving a voltage measurement command from the battery monitoring device 1. The update data from the OTA center 200 may also be a battery monitoring program that causes the controller 30 to measure voltage at a second timing set based on the second output signal.

[0110] Next, the processing in the battery monitoring system S according to the modified example will be specifically described with reference to Figures 10 and 11. Figure 10 is a flowchart showing the processing procedure executed by the TCU 60 according to the modified example.

[0111] 10, the TCU 60 inquires of the OTA center 200 whether or not there is update data (step S301). Subsequently, the TCU 60 determines whether or not the response from the OTA center 200 indicates that there is update data (step S302).

[0112] If there is update data (step S302: Yes), the TCU 60 receives the update data from the OTA center 200 (step S303). If there is no update data (step S302: No), the TCU 60 ends the process.

[0113] Next, the TCU 60 transmits the received update data to the battery monitoring device 1 (step S304). Specifically, the update data transmitted from the OTA center 200 is associated with identification information indicating the target device, and the TCU 60 transmits the update data to the battery monitoring device 1 when the identification information indicates the battery monitoring device 1.

[0114] Next, the TCU 60 determines whether all the update data has been received from the OTA center 200 (step S305), and if all the update data has been received (step S305: Yes), the TCU 60 ends the process. Note that if all the update data has not been received (step S305: No), that is, if the update data to be received exists in the OTA center 200, the TCU 60 returns to step S303 and receives the update data again.

[0115] 11 is a flowchart showing the procedure of processing executed by the battery monitoring device 1 according to the modified example. As shown in FIG. 11, the battery monitoring device 1 determines whether or not update data has been received from the TCU 60 (step S401).

[0116] If the battery monitoring device 1 receives update data from the TCU 60 (step S401: Yes), it stores the received update data in the storage unit (step S402). If the battery monitoring device 1 has not received update data (step S401: No), it ends the process.

[0117] Next, the battery monitoring device 1 determines whether the ignition switch of the vehicle 210 has been turned off (step S403). If the ignition switch has been turned off (step S403: Yes), the battery monitoring device 1 reads out update data from the storage unit (step S404). If the ignition switch has not been turned off (step S403: No), the battery monitoring device 1 repeatedly executes step S403 until the ignition switch is turned off.

[0118] Next, the battery monitoring device 1 updates the battery monitoring program with the read update data (step S405) and ends the process. Note that if the update data includes update data for the measuring device 10, the battery monitoring device 1 transmits the update data to the measuring device 10. This enables the measuring device 10 to update the battery monitoring program in accordance with the update data.

[0119] Although the above description shows an example in which the battery monitoring device 1 is updated based on update data from the OTA center 200, the measuring device 10 may also be updated based on update data from the OTA center 200.

[0120] The battery monitoring device 1, measurement device 10, and methods described herein may be implemented by a special-purpose computer provided by configuring a processor and memory programmed to perform one or more functions embodied in a battery monitoring program. Alternatively, the battery monitoring device 1, measurement device 10, and methods described herein may be implemented by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits.

[0121] Alternatively, the battery monitoring device 1, the measurement device 10, and the methods described herein may be implemented by one or more dedicated computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured by one or more hardware logic circuits. Also, the program may be stored as instructions executed by the computer on a computer-readable non-transitory tangible storage medium.

[0122] The storage unit of the battery monitoring device 1 may retain the program before the update even after updating based on the update data, so that if the update data is abnormal, the device can operate using the program before the update.

[0123] The following configuration may also be adopted.

[0124] The TCU 60 transmits the update data received from the OTA center 200 to the communication unit 20 of the measuring device 10 via the antenna 61. The measuring device 10 stores the update data received from the antenna 61 via the communication unit 20 in a memory unit. When all update data downloading via the TCU 60 is complete, the measuring device 10 enters an update-enabled state. Here, when the ignition switch is turned off, the controller 30 of the measuring device 10 performs an update based on the update data stored in the memory unit.

[0125] Furthermore, the updating of the measuring device 10 is not limited to the above example, but the measuring device 10 may be updated by the controller 3 of the battery monitoring device 1 executing an update based on update data.

[0126] Further advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0127] 1 Battery monitoring device 2, 20 Communications Department 3, 30 Controller 10. Measuring equipment 40 Monitoring IC 50 batteries 51 cells 61 Antenna 100 Current Sensor 200 OTA Center 210 vehicles N Communication Network S Battery Monitoring System

Claims

1. a current measuring device that measures the current of the battery and outputs the current value; a voltage measurement device including a voltage measurement circuit that measures the voltage of a battery, a first microcomputer that controls the voltage measurement circuit, and a first wireless communication unit that wirelessly outputs the measured voltage value; a battery monitoring device including a second wireless communication unit that wirelessly communicates with the first wireless communication unit, and a second microcomputer to which the current value and the voltage value are input, the second microcomputer outputs a current measurement request signal to the current measuring device after a first time period based on an output signal from the second wireless communication unit has elapsed; The first microcomputer controls the voltage measurement circuit to measure the voltage after a second time synchronized with the first time has elapsed, based on an output signal from the first wireless communication unit. Battery monitoring system.

2. the second microcomputer causes the second wireless communication unit to transmit a voltage measurement command; the second wireless communication unit outputs an output signal when transmitting the voltage measurement command by wireless communication; the first wireless communication unit outputs an output signal when receiving the voltage measurement command via wireless communication; When the first microcomputer receives the voltage measurement command from the first wireless communication unit, the first microcomputer controls the voltage measurement circuit to measure the voltage. The battery monitoring system of claim 1 .

3. The second time is a time obtained by adding or subtracting a time difference between the timing at which the output signal from the first wireless communication unit and the timing at which the output signal from the second wireless communication unit is output to or from the first time. The battery monitoring system according to claim 1 or 2.

4. The second microcomputer Based on the output signal output from the second wireless communication unit, the elapsed time from the start to the end of communication with the voltage measurement device is measured, and if the elapsed time is outside a normal time range, the measurement process of the current value is stopped. The battery monitoring system of claim 1 .

5. The first microcomputer Based on the output signal output from the first wireless communication unit, the elapsed time from the start to the end of communication with the battery monitoring device is measured, and if the elapsed time is outside a normal time range, the measurement process of the voltage value is stopped. The battery monitoring system of claim 1 .

6. The second microcomputer When measuring the voltage value, a voltage measurement command is transmitted to the voltage measurement device; The first microcomputer If the voltage measurement command is not included in the data received from the battery monitoring device, the voltage value measurement process is stopped. The battery monitoring system of claim 1 .

7. The first microcomputer transmitting the voltage value measured after the second time has elapsed within the first communication cycle to the battery monitoring device in a second communication cycle that is a cycle following the first communication cycle; The second microcomputer The state of the battery is determined based on the current value measured after the first time period has elapsed within the second communication period and the voltage value received from the voltage measurement device during the second communication period. The battery monitoring system of claim 1 .

8. A battery monitoring device that is wirelessly connected to a voltage measurement device that measures the voltage of a battery, a wireless communication unit that receives a voltage value wirelessly output from the voltage measurement device; a microcomputer to which the voltage value and the battery current value measured by a current measuring device are input, The microcomputer outputs a current measurement request signal to the current measuring device after a second time has elapsed, the second time being synchronized with a first time used to set the measurement timing of the voltage measuring device, based on the output signal from the wireless communication unit. Battery monitoring device.

9. A voltage measurement device that is wirelessly connected to a battery monitoring device to which a current value is input from a current measurement device that measures a current of a battery, a voltage measurement circuit for measuring the voltage of the battery; a microcomputer that controls the voltage measurement circuit; a wireless communication unit that wirelessly outputs a voltage value to the battery monitoring device; The microcomputer controls the voltage measurement device to measure the voltage after a second time has elapsed, the second time being synchronized with a first time used to set the measurement timing of the current measurement device, based on the output signal from the wireless communication unit. Voltage measurement device.

Images