Battery Monitoring System

Abstract

To suppress accumulation of errors.SOLUTION: A battery monitoring system 100 comprises a battery monitoring ECU10 and a plurality of battery monitoring devices 30. The battery monitoring ECU includes: a first clock generator 12; and a transceiver 16 that outputs a signal from which a first clock signal is identified and an instruction regarding monitoring a battery to the battery monitoring device, and receives a result of the instruction from the battery monitoring device. The battery monitoring device includes: a receiver 42 that receives the signal from a preceding device; a second clock generator 50; a frequency correction section that corrects the frequency of the second clock signal; a battery monitoring section 54 that monitors the battery using the second clock signal; a controller 48 that causes the frequency correction section to correct the frequency of the second clock signal in line with the first clock signal according to the signal received via the receiver and causes the battery monitoring section to monitor the battery using the corrected second clock; a transmitter 44 that transmits a monitoring result of the battery to a succeeding device; and a switching section 46 that switches a circuit configuration to a state in which the signal transmitted from the preceding device is output to the succeeding device.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a battery monitoring system. [Background technology]

[0002] In recent years, the number of moving objects such as vehicles and aircraft using secondary batteries has been increasing. There is an increasing demand for a battery monitoring system (Battery Management System: BMS) that acquires the internal state of a secondary battery, including the remaining capacity (State of Charge: SOC) of the secondary battery, by measuring the electrical characteristics of the secondary battery. Patent Document 1 discloses a battery monitoring system in which a plurality of batteries are monitored by a plurality of battery monitoring ICs and the plurality of battery monitoring ICs are daisy-chained. In such a battery monitoring system, a battery monitoring ECU that controls the entire system is provided, and when an instruction or the like is output from the battery monitoring ECU to a first-stage battery monitoring device, each of the plurality of battery monitoring devices connected in the daisy chain adds its own data or the like to the information received from the previous stage and sends it to the subsequent stage. The final-stage battery monitoring device outputs all information to the battery monitoring ECU. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-53579 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, since each battery monitoring device has an oscillator and operates using the oscillation frequency, when multiple battery monitoring devices are connected in a daisy chain and high-precision data on operation timing is transferred from the battery monitoring device, there are cases where the accuracy cannot be maintained. For example, in a case where each battery monitoring device performs AC impedance measurement, it is assumed that in order to increase the accuracy of the frequency used for measurement by each battery monitoring device, the battery monitoring ECU uses a high-precision oscillator to output precise timing data to the battery monitoring device. In this case, when each battery monitoring device sends the timing data received from the battery monitoring ECU to the battery monitoring device at the subsequent stage via the daisy chain connection, there is a problem that errors associated with the receiving and transmitting operations of each battery monitoring device are superimposed, and the further down the stage, the more errors accumulate in the timing data. [Means for solving the problem]

[0005] The present disclosure has been made to solve at least a part of the above-mentioned problems, and can be realized in the following forms.

[0006] According to one embodiment of the present disclosure, there is provided a battery monitoring system (100) for monitoring the battery states of a plurality of batteries. The battery monitoring system includes a battery monitoring ECU (10) and a plurality of battery monitoring devices (30), the battery monitoring ECU and the plurality of battery monitoring devices are connected in any one of a ring connection, a daisy chain connection, and a multi-drop connection, Furthermore, each of the plurality of battery monitoring devices (30) is connected such that one battery monitoring device is in a front-stage / rear-stage relationship with another battery monitoring device, The battery monitoring ECU includes a clock generating unit (12) that generates a first clock signal, and a clock generating unit (12) that transmits the first clock signal to at least one of the battery monitoring devices. No. and a transmitter / receiver unit (16) that outputs instructions relating to the monitoring of the battery and receives results of the instructions from at least one of the battery monitoring devices, The battery monitoring ECU or the other battery monitoring device corresponding to the previous stagea receiver (42) for receiving a signal from the battery, a second clock generator (50) for generating a second clock signal that is a reference for the operation of the receiver, a frequency correction unit for correcting the frequency of the second clock signal, a battery monitor (54) for monitoring the battery using the second clock signal, and From the battery monitoring ECU or another battery monitoring device corresponding to the previous stage The received signal When the instruction for correcting the second clock is included, The frequency correction unit is configured to correct the frequency of the second clock signal. of The first clock signal To synchronize with the frequency of a control unit (48) for correcting the second clock and causing the battery monitoring unit to perform the monitoring using the corrected second clock; Signals containing A transmission unit (44) that outputs a signal sent from the previous stage in response to an instruction from the battery monitoring ECU. After Output to the stage or output a signal including the result of monitoring the battery to a later stage. Switch Do the drawing The battery monitoring system of this embodiment can prevent the frequency error from accumulating. Battery Monitoring The battery monitoring system including the device is low-cost and has multiple Battery Monitoring The oscillation frequencies of the devices can be synchronized.

[0007] The present disclosure may be realized in various forms, for example, in the form of a battery monitoring method. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram of a battery monitoring system according to a first embodiment. [Diagram 2] FIG. 4 is an explanatory diagram showing a configuration of a switching unit. [Diagram 3] 4 is a flowchart of a process executed by a control unit of the battery monitoring system. [Figure 4] 4 is a flowchart of a process executed by a control unit of the battery monitoring device. [Diagram 5] 4 is an explanatory diagram showing a transmission signal of the battery monitoring ECU, a reception signal of each battery monitoring device, and a period (1 / frequency) of the transmission signal in the measurement mode. FIG. [Figure 6] FIG. 11 is a schematic configuration diagram of a battery monitoring system according to a second embodiment. [Figure 7] FIG. 11 is a schematic configuration diagram of a battery monitoring system according to a third embodiment. [Figure 8] FIG. 13 is a schematic configuration diagram of a battery monitoring system according to a fourth embodiment. [Figure 9] FIG. 13 is an explanatory diagram showing a first superimposed signal transmitted by a battery monitoring ECU in a correction mode and a first superimposed signal received and transmitted by each battery monitoring device in the fifth embodiment. [Figure 10] FIG. 23 is an explanatory diagram showing a first superimposed signal transmitted by a battery monitoring ECU in a correction mode and a first superimposed signal received and transmitted by each battery monitoring device in the sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] First embodiment: Battery monitoring system 100 includes: As shown in FIG. 1, the battery monitoring system 100 includes a battery monitoring ECU 10 and a plurality of (m in this embodiment, m is an integer of 2 or more) battery monitoring devices 30. The battery monitoring devices 30 in each stage monitor the state of n (n is an integer of 1 or more) secondary batteries (hereinafter referred to as "batteries") included in the battery set CSx (x is any one of 1 to m) in each stage. Therefore, the battery monitoring system 100 monitors the battery states of a plurality of (m×n in this embodiment) batteries C11 to Cmn. Note that, in this embodiment, the number of batteries monitored by the battery monitoring devices 30 in each stage is the same as n, but the number of batteries monitored by the battery monitoring devices 30 in each stage may be different.

[0010] The battery monitoring ECU 10 has two connection parts 18, 20, and each battery monitoring device 30 has two connection parts 34, 36. The battery monitoring ECU 10 and the multiple battery monitoring devices 30 are connected in a ring. That is, one connection part 18 of the battery monitoring ECU 10 is connected to one connection part 34 of the first-stage battery monitoring device 30 by a transmission line 22. The other connection part 36 of the first-stage battery monitoring device 30 is connected to one connection part 34 of the second-stage battery monitoring device 30 by a transmission line 24. The other connection part 34 of the second-stage battery monitoring device 30 is connected to one connection part 34 of the third-stage battery monitoring device 30 by a transmission line 25. From here on, the other connection part 36 of the previous stage is connected to one connection part 34 of the current stage by a transmission line until the final stage. The other connection part 36 of the battery monitoring device 30 in the m-th stage, which is the final stage, is connected to the other connection part 20 of the battery monitoring ECU 10 by a transmission line 26. In this manner, the battery monitoring ECU 10 and the multiple battery monitoring devices 30 are connected to form a ring.

[0011] Although details will be described later, the battery monitoring ECU 10 operates based on a first clock signal that it generates, and the battery monitoring device 30 operates based on a second clock signal that it generates. The battery monitoring device 30 has two operation modes, a correction mode and a measurement mode, which can be switched by instructions from the battery monitoring ECU 10. The correction mode is an operation mode in which a process is performed to correct the second clock signal and synchronize it with the first clock signal, and the measurement mode is an operation mode in which a process is performed to obtain the state of the battery using the second clock signal.

[0012] In the correction mode, the battery monitoring device 30 receives a first superimposed signal from the previous stage of the ring connection. The first superimposed signal is a signal in which clock frequency information and battery monitoring information are superimposed on a first clock signal. The battery monitoring device 30 generates a reference clock signal having the same frequency as the first clock signal from the first superimposed signal. The battery monitoring device 30 synchronizes the second clock signal generated by itself with the reference clock signal so that the frequency of the second clock signal becomes the same as the frequency of the reference clock signal. As a result, the second clock signal is synchronized with the first clock signal. Also, in the correction mode, the battery monitoring device 30 transmits the first superimposed signal received from the previous stage to the subsequent stage as it is.

[0013] On the other hand, in the measurement mode, the battery monitoring device 30 of each stage uses the second clock signal generated by itself to Battery Monitoring The battery monitoring device 30 acquires the battery status, including the remaining capacity (State of Charge: SOC) of the n batteries in the battery set connected to the device 30. The battery monitoring device 30 generates a second superimposed signal by superimposing the measurement results from the first stage to the previous stage and the measurement result of the battery status of the current stage on the second clock signal, and transmits the second superimposed signal to the subsequent stage.

[0014] The configurations of the battery monitoring ECU 10 and the battery monitoring device 30 will be described below. The battery monitoring ECU 10 includes a first clock generating unit 12, a control unit 14, a transmission / reception unit 16, and the above-mentioned connection units 18 and 20. The first clock generating unit 12 generates a first clock signal on which the operation of the battery monitoring ECU 10 is based. The first clock generating unit 12 uses a crystal oscillator to generate the first clock signal, which is a highly accurate clock signal. The first clock generating unit 12 may use an oscillator other than a crystal oscillator, for example, a silicon MEMS oscillator. The first clock generating unit 12 may also receive a signal generated by a GNSS disciplined frequency generator from a GNSS satellite to generate the first clock signal.

[0015] The control unit 14 generates a first superimposed signal by superimposing the clock frequency information and the battery monitoring information on the first clock signal, and sends the first superimposed signal to the transmission / reception unit 16. The clock frequency information is information indicating the frequency of the first clock signal. The battery monitoring information is Battery Monitoring Information identifying the battery that the device 30 should monitor; Battery Monitoring Putting the device 30 into a correction mode in which a correction of the frequency of the second clock signal is performed, or Battery Monitoring The battery monitoring information includes a mode switching instruction that instructs device 30 to transition to a measurement mode in which the device 30 monitors the battery. The information identifying the battery to be monitored in the battery monitoring information indicates which battery should be monitored. The battery to be monitored may be one specific battery in a specific set, specific batteries in a specific set, all batteries in a specific set, or all batteries in all sets.

[0016] The clock frequency information and the battery monitoring information are superimposed on the first clock signal by, for example, phase encoding using the Manchester code. The battery monitoring information may be superimposed by a method other than phase encoding using the Manchester code, for example, phase shift keying.

[0017] The transmitter / receiver 16 outputs instructions relating to battery monitoring to at least one of the battery monitoring devices 30, and receives the results of the instructions from at least one of the battery monitoring devices 30. The transmitter / receiver 16 generates a differential signal from the first superimposed signal, and transmits it to the transmission path 22 via the connection unit 18. A differential signal is a signal in which one signal is divided into two signals of opposite phase to each other. The transmission paths 22, 26 that connect the battery monitoring ECU 10 and the battery monitoring devices 30, and the transmission paths 22, 26 that connect the battery monitoring ECU 10 and the battery monitoring devices 30 Battery Monitoring Each of the transmission paths 24, 25, ... connecting the devices has two signal lines. The transmitting / receiving unit 16 transmits the original signal to one of the two signal lines of the transmission path 22, and transmits an opposite-phase signal, in which H and L are inverted, to the other signal line. The connecting unit 18 has a capacitor, and connects the transmitting / receiving unit 16 and the transmission path 22 via the capacitor. Therefore, the connecting unit 18 does not transmit the DC component of the signal, but transmits only the AC component.

[0018] The transmitter / receiver 16 also receives an operation signal of the second superimposed signal on which the battery monitoring result is superimposed from the battery monitoring device 30 in the final stage via the transmission line 26 and the connection unit 20, and restores the second superimposed signal. Battery Monitoring Device 30 Battery Monitoring Received from ECU10 Battery Monitoring The battery monitoring process is performed based on the information, and includes information identifying the monitored battery and the measurement results of the state of the monitored battery. Like the connection unit 18, the connection unit 20 has a capacitor, and connects the transmission path 26 and the transceiver unit 16 via the capacitor. The connection unit 20 does not transmit the DC component of the signal, but transmits only the AC component. Note that the connection units 18 and 20 may be composed of a transformer instead of a capacitor.

[0019] The battery monitoring device 30 includes a battery monitoring IC 40 and a filter 60. The battery monitoring IC 40 includes a receiver 42, a transmitter 44, a switching unit 46, a control unit 48, a second clock generating unit 50, a frequency correcting unit 52, a battery monitoring unit 54, and the above-mentioned connection units 34 and 36. The receiver 42 is connected to the connection unit 34, and the transmitter 44 is connected to the connection unit 36. The receiver 42 and the transmitter 44 are connected to the switching unit 46, and the switching unit 46 is connected to the control unit 48. The second clock generating unit 50, the frequency correcting unit 52, and the battery monitoring unit 54 are connected to the control unit 48. The battery monitoring unit 54 is connected to the battery via the filter 60.

[0020] The receiving unit 42 of the first-stage battery monitoring device 30 is connected to the transmitting / receiving unit 16 of the battery monitoring ECU 10 via the connection unit 34, the transmission path 22, and the connection unit 18. The receiving units 42 of the second-stage to m-th-stage battery monitoring devices 30 are each connected to the transmitting unit 44 of the previous-stage battery monitoring device 30 via the connection unit 34, the transmission paths 24, 25, ..., and the connection unit 36. The transmitting unit 44 of the m-th-stage battery monitoring device 30 is connected to the transmitting / receiving unit 16 of the battery monitoring ECU 10 via the connection unit 36, the transmission path 26, and the connection unit 20.

[0021] The receiver 42 receives the activation signal from the preceding device and restores the superimposed signal. Battery Monitoring If the ECU 10 is the control unit 48 of the battery monitoring device 30 in the second to mth stages, Battery Monitoring The transmitter 44 generates an activation signal from the superimposed signal and transmits it to the downstream device. Here, if the control unit 48 of the downstream device is the control unit 48 of the battery monitoring device 30 in the 1st to (m-1)th stages, Battery Monitoring If the control unit 48 is the control unit 48 of the m-th battery monitoring device 30, Battery Monitoring ECU10.

[0022] The control unit 48 generates a reference clock signal from the superimposed signal received by the receiving unit 42, and decodes the clock frequency information and the battery monitoring information. The superimposed signal is either the first superimposed signal or the second superimposed signal. As described above, the first superimposed signal is Battery Monitoring The second superimposed signal is a superimposed signal generated by the ECU 10 superimposing the clock frequency information of the first clock signal and the battery monitoring information onto the first clock signal. On the other hand, the second superimposed signal is a superimposed signal generated by the battery monitoring device 30 at the preceding stage superimposing the clock frequency information of the second clock signal, the battery monitoring information, and the battery monitoring result onto the second clock signal, as will be described later. Whether the superimposed signal is the first superimposed signal or the second superimposed signal depends on the following: Battery Monitoring The battery monitoring device 30 is in either the correction mode or the measurement mode. Battery Monitoring This is commanded by the ECU 10. The switching of the operation modes will be described later.

[0023] First tier Battery Monitoring In the device 30, the superimposed signal received is the first superimposed signal regardless of the operation mode. Battery Monitoring In the device 30, the superimposed signal received is Battery Monitoring When the device 30 is in the correction mode, it is the first superimposed signal, Battery MonitoringWhen the device 30 is in the measurement mode, the second superimposed signal is generated. The control unit 48 performs the following in accordance with the mode switching instruction of the battery monitoring information superimposed on the superimposed signal: Battery Monitoring The operation mode of the device 30 is shifted to a correction mode or a measurement mode. In the correction mode, the control unit 48 transmits the first superimposed signal received from the previous stage to the subsequent stage. On the other hand, in the measurement mode, the control unit 48 generates a second superimposed signal in which the clock frequency information, the battery monitoring information, and the battery monitoring result are superimposed on a second clock signal, and transmits the generated second superimposed signal via the transmission unit 54 to the subsequent stage.

[0024] The reference clock signal is the clock signal restored from the received superimposed signal before superimposition. Battery Monitoring In the device 30, the frequency of the reference clock signal is the same as that of the first clock signal, and the second to mth stages Battery Monitoring In the device 30, the frequency of the reference clock signal is Battery Monitoring When the device 30 is in the correction mode, the frequency of the first clock signal is the same as that of the previous stage. Battery Monitoring When the device 30 is in the measurement mode, it has the same frequency as the second clock signal of the preceding stage.

[0025] The second clock generating unit 50 generates a second clock signal that is a reference for the operation of its own battery monitoring device 30. The second clock generating unit 50 is configured using an LC oscillator that is simpler than the crystal oscillator used in the first clock generating unit 12. Therefore, the second clock signal is a clock signal with lower accuracy compared to the first clock signal. Since the second clock generating unit 50 uses an LC oscillator, the oscillation frequency can be changed and corrected by changing the capacitance of a capacitor that constitutes the LC oscillator or the inductance that constitutes an inductor according to an instruction from a frequency correcting unit 52 described later.

[0026] The control unit 48 decodes the superimposed signal received from the previous stage. Battery Monitoring In accordance with the mode switching instruction of the information signal, the voltage measuring device 30 of the current stage is switched to the correction mode or the measurement mode.

[0027] In the correction mode, the control unit 48 sends a correction instruction to the frequency correction unit 52 to correct the second clock signal generated by the second clock generation unit 50 so that the frequency of the second clock signal generated by the second clock generation unit 50 matches the frequency of the reference clock signal and, in turn, the frequency of the first clock signal. Upon receiving the correction instruction from the control unit 48, the frequency correction unit 52 detects a difference in frequency between the signal received from the previous stage and the second clock signal, and causes the second clock generation unit 50 to correct the oscillation frequency of the second clock signal to be generated. As a correction method for correcting the second clock signal, the frequency correction unit 52 uses a counter method that uses a count difference between the reference clock signal generated by the control unit 48 from the superimposed signal and the second clock signal generated by the second clock generation unit 50. The frequency correction unit 52 corrects the oscillation frequency of the second clock generation unit 50 so that the counter difference becomes zero. Also, in the correction mode, the control unit 48 causes the switching unit 46 to switch the communication path so that the superimposed signal received from the previous stage is transmitted to the subsequent stage.

[0028] In the measurement mode, the control unit 48 causes the battery monitoring unit 54 to monitor the battery specified by the battery monitoring information and acquires the measurement result of the battery state. The battery monitoring unit 54 acquires the battery state by an AC impedance method using a second clock signal. The control unit 48 may cause the battery monitoring unit 54 to constantly monitor the battery state, and acquire the measurement result of the battery state from the battery monitoring unit 54 when the battery monitoring information includes a specified battery. The control unit 48 generates a second superimposed signal by superimposing the clock frequency information, the battery monitoring information, and the measurement result of the monitored battery state on the second clock signal, and sends the second superimposed signal to the switching unit 46. The control unit 48 causes the switching unit 46 to switch the communication path so as to transmit the generated second superimposed signal to the transmission unit 54.

[0029] The switching unit 46 is disposed between the receiving unit 42, the transmitting unit 44, and the control unit 48. The switching unit 46 is Battery Monitoring ECU10 and multiple Battery MonitoringWhile maintaining the connection between the devices 30, the switching unit 46 switches between the superimposed signal received from the previous stage, i.e., the signal from the receiving unit 42, and the second superimposed signal from the control unit 48 as the signal to be sent to the transmitting unit 44. In the correction mode, the switching unit 46 sends the superimposed signal received from the previous stage. On the other hand, in the measurement mode, the switching unit 46 sends the second superimposed signal from the control unit 48 as the signal to be sent to the transmitting unit 44.

[0030] FIG. 2 is an explanatory diagram showing the configuration of the switching unit 46. The switching unit 46 includes two input units in1 and in2, two output units out1 and out2, and a selector 47. The input unit in1 is connected to the receiving unit 42, and the input unit in2 and the output unit out1 are connected to the control unit 48. The output unit out2 is connected to the transmitting unit 44. A signal input from the receiving unit 42 to the input in1 is branched into two, one of which is output to the output unit out1 as is and sent to the control unit 48. The other of the branched signals input to the input in1 is input to the selector 47. A signal input from the control unit 48 to the input in2 is input to the selector 47. The signal output from the selector 47 is output from the output unit out2 and sent to the transmitting unit 44. The switching signal Ss is generated by the control unit 48 and input to the switching unit 46. For example, the switching signal Ss is at the "H" level in the correction mode and at the "L" level in the measurement mode. When the switching signal Ss is at the “H” level, the selector 47 outputs the superimposed signal input from the input in1. On the other hand, when the switching signal Ss is at the “L” level, the selector 47 outputs the second superimposed signal from the control unit .

[0031] ·· Battery Monitoring System 100 Operation: Figure 3 shows Battery Monitoring 1 is a flowchart of a process executed by the control unit 14 of the system 100. In step S10, Battery Monitoring The control unit 14 of the ECU 10 Battery Monitoring The device 30 is instructed to transition to the correction mode. Specifically, Battery Monitoring The control unit 14 of the ECU 10 receives the mode switching instruction as follows: Battery MonitoringThe first superimposed signal, on which the battery monitoring information is superimposed, includes an instruction to transition the device 30 to a correction mode in which the frequency of the second clock signal is corrected. Battery Monitoring The first superimposed signal is transmitted to the first stage device 30. Battery Monitoring When the device 30 goes into the correction mode, the first stage Battery Monitoring The switching unit 46 of the device 30 is switched so as to transmit the superimposed signal from the previous stage to the next stage. As a result, the first superimposed signal is Battery Monitoring Similarly, the second stage Battery Monitoring When the device 30 goes into the correction mode, the second stage Battery Monitoring The switching unit 46 of the device 30 is switched so as to transmit the superimposed signal from the previous stage to the next stage. As a result, the first superimposed signal is Battery Monitoring The first superimposed signal is then transmitted to the device 30 in the same manner. Battery Monitoring The final stage is transmitted to the device 30. Battery Monitoring From device 30 Battery Monitoring When the first superimposed signal returns to ECU 10, all Battery Monitoring The transition of the device 30 into the correction mode is complete.

[0032] In step S20, the control unit 14 Battery Monitoring In the device 30, when it is determined that the frequency of the second clock signal is synchronized with the frequency of the first clock signal and that correction has been completed (true (T)), the process proceeds to step S30. In step S20, when the control unit 14 determines that the frequency of the second clock signal is not synchronized with the frequency of the first clock signal and that correction has not been completed (false (F)), the process of step S20 is repeated until it is determined to be true (T). Note that it takes a certain amount of time for the frequency of the second clock signal to synchronize with the frequency of the first clock signal. Therefore, the control unit 14 performs the final stage Battery Monitoring From device 30 Battery Monitoring Until a certain time has elapsed since the first superimposed signal was returned to the ECU 10, the determination in step S20 may be false (F), and thereafter the determination in step S20 may be true (T).

[0033] In step S30, the control unit 14 Battery MonitoringThe device 30 is instructed to transition to the measurement mode. Specifically, Battery Monitoring The control unit 14 of the ECU 10 receives a mode switching instruction. Battery Monitoring The first superimposed signal on which the battery monitoring information including an instruction to cause the device 30 to transition to a measurement mode for monitoring the battery is superimposed is Battery Monitoring The first stage is transmitted to the device 30. Battery Monitoring When the device 30 is in the measurement mode, the first stage Battery Monitoring The second superimposed signal generated by the control unit 48 of the device 30 is Battery Monitoring The second stage is transmitted to the device 30. Battery Monitoring When the device 30 goes into measurement mode, the second stage Battery Monitoring The second superimposed signal generated by the control unit 48 of the device 30 is Battery Monitoring 30. Battery Monitoring The second superimposed signal is transmitted to the device 30. Battery Monitoring From device 30 Battery Monitoring When the second superimposed signal returns to ECU 10, all Battery Monitoring The device 30 transitions to the measurement mode. In step S40, the control unit 14 decodes the second superimposed signal to obtain the monitored state of the battery.

[0034] Figure 4 shows Battery Monitoring 1 is a flowchart of a process executed by the control unit 48 of the device 30. In step S100, the control unit 48 receives a superimposed signal from a previous device through the receiving unit 42. Here, the previous device is Battery Monitoring Device 30 is the first stage Battery Monitoring For equipment, Battery Monitoring ECU10, Battery Monitoring The device 30 is the second to mth stage. Battery Monitoring For equipment, Battery Monitoring The device is 30.

[0035] In step S110, the control unit 48 generates a reference clock signal from the received superimposed signal. In step S120, the control unit 48 decodes the superimposed signal to obtain clock frequency information and Battery MonitoringThe control unit 48 acquires a mode switching instruction as to whether the device 30 should be switched to the correction mode or the measurement mode. Note that the control unit 48 may execute either step S110 or S120 first. In step S130, the control unit 48 determines that the mode switching instruction is Battery Monitoring The control unit 48 determines whether the mode switching instruction is to switch the device 30 to the correction mode. Battery Monitoring If the instruction is true (T), which indicates that the device 30 should be switched to the correction mode, the process proceeds to step S140. Battery Monitoring If the instruction is not to switch the device 30 to the correction mode (F), the mode switching instruction is Battery Monitoring This is an instruction to switch the device 30 to the measurement mode, and the process proceeds to step S170.

[0036] In step S140, the control unit 48 Battery Monitoring In step S150, the control unit 48 causes the frequency correction unit 52 to correct the frequency of the second clock signal generated by the second clock generation unit 50. In step S160, the control unit 48 causes the switching unit 46 to transmit the superimposed signal received from the previous stage to the subsequent stage. This causes the first superimposed signal to be transmitted to the subsequent stage. Battery Monitoring It is transmitted to the device 30.

[0037] All Battery Monitoring When the second clock signal of the device 30 is corrected so that the frequency of the second clock signal is synchronized with the frequency of the first clock signal, Battery Monitoring ECU10 is Battery Monitoring The instrument 30 is placed into measurement mode.

[0038] Battery Monitoring ECU10 Battery Monitoring When the device 30 is put into a measurement mode, Battery Monitoring The processes in steps S100 to S130 in the device 30 are the same. However, since the determination result in step S130 is false (F), Battery Monitoring The apparatus 30 transitions to step S170.

[0039] In step S170, the control unit 48 Battery Monitoring In step S180, the control unit 48 causes the battery monitoring unit 54 to acquire the battery status. In step S190, the control unit 48 acquires the clock frequency information and Battery Monitoring The second superimposed signal is generated by superimposing an instruction to switch the device 30 to the measurement mode, the battery monitoring information, and the battery status, which is the monitoring result, on the second clock signal. Note that the battery status, which is the monitoring result, is added sequentially. Battery Monitoring The second superimposed signal generated by the device 30 includes the monitoring result of the battery of the first set CS1, and Battery Monitoring The second superimposed signal generated by the device 30 includes the monitoring results of the batteries of the first stage Cs1 and the second stage CS2. Battery Monitoring The second superimposed signal generated by the device 30 includes the monitoring results of the batteries from the first stage Cs1 to the xth stage Cx1. In step S200, the control unit 48 causes the switching unit 46 to transmit the second superimposed signal to the subsequent stage. As a result, the second superimposed signal on which the measurement results up to the current stage are superimposed is transmitted to the Battery Monitoring It is transmitted to the device 30.

[0040] FIG. 5 shows the transmission signal of the battery monitoring ECU 10 in the measurement mode and each Battery Monitoring 2 is an explanatory diagram showing the period (1 / frequency) of a received signal and a transmitted signal of the device 30. FIG. Battery Monitoring When the control unit 48 of the device 30 does not perform the correction in this embodiment, Battery Monitoring If the period of the first superimposed signal (first clock signal) transmitted by the ECU 10 is p0, then the first stage Battery Monitoring The period of the first superimposed signal (first clock signal) received by the receiving unit 42 of the device 30 is also p0. Battery Monitoring The period p1 of the second superimposed signal (second clock signal) transmitted by the transmission unit 44 of the device 30 is p0+pc, which is the period p0 of the battery monitoring ECU 10 plus an error pc. Battery Monitoring The period of the second superimposed signal (second clock signal) received by the receiving unit 42 of the device 30 is also p0+pc. Battery MonitoringThe period p2 of the second superimposed signal (second clock signal) transmitted by the transmitter 44 of the device 30 is p1+pc, which is obtained by adding an error pc to the period p1 of the first-stage battery monitoring device 30, i.e., p0+2pc. Therefore, the period px after x stages is p0+xpc, and the error accumulates in the later stages, reaching a maximum error in the final stage, the mth stage.

[0041] In response to this, Battery Monitoring When the control unit 48 of the device 30 executes the correction in this embodiment, the first stage Battery Monitoring The period p1 of the second superimposed signal (second clock signal) transmitted by the transmitting unit 44 of the device 30 is the same as the period p0 of the first superimposed signal (first clock signal) of the battery monitoring ECU 10. Battery Monitoring The period of the second superimposed signal (second clock signal) received by the receiving unit 42 of the device 30 and the second stage Battery Monitoring The period of the second superimposed signal (second clock signal) transmitted by the transmitting unit 44 of the device 30 is also the same as the period p0 of the first superimposed signal (first clock signal) of the battery monitoring ECU 10. Battery Monitoring The period, i.e., frequency, of the second clock of the device 30 is the same as the period, i.e., frequency, of the first clock signal, so that no frequency error accumulates. Battery Monitoring This includes the error due to correction by the device 30.

[0042] As described above, according to this embodiment, Battery Monitoring The device 30 includes a switching unit 46 that switches the circuit configuration to a state in which a signal sent from a previous stage is output to a subsequent stage without using the second clock signal upon receiving an instruction from the battery monitoring ECU 10. Battery Monitoring The system 100 can suppress the spread of frequency errors and achieve frequency synchronization at low cost.

[0043] According to this embodiment, the switching unit 46 switches the circuit configuration to a state in which the signal sent from the previous stage is output to the subsequent stage only during a predetermined period, and switches the circuit configuration to a state in which the signal generated in the current stage is output to the subsequent stage outside the predetermined period. As a result, the battery status monitored in the current stage is not displayed during the period other than the predetermined period. Battery MonitoringIt can be sent to ECU10.

[0044] According to this embodiment, Battery Monitoring The device 30 includes a frequency correction unit 52 that detects a deviation between the frequencies of a reference clock signal (first clock signal) and the second clock signal and corrects the frequency of the second clock signal, so that the frequency of the second clock signal can be corrected so that the frequency of the second clock signal approaches the frequency of the first clock signal.

[0045] According to this embodiment, the frequency correction unit 52 can detect the frequency deviation between the first clock signal and the second clock signal by various methods. For example, if the frequency correction unit 52 uses a counter method that uses the count difference between the first clock signal and the second clock signal, the frequency deviation can be easily detected by the count difference. In addition, the frequency correction unit 52 may adopt a phase-locked loop method or a delay-locked loop method.

[0046] According to this embodiment, since the switching unit 46 is provided on the control unit 48 side of the receiving unit 42 and the transmitting unit 44, the strength of the signal that has passed through the switching unit 46 can be made stronger by the transmitting unit 44.

[0047] Second embodiment: FIG. 6 is a schematic configuration diagram of a battery monitoring system 101 according to the second embodiment. Battery Monitoring The device 30 includes a switching unit 46 between the receiving unit 42, the transmitting unit 44, and the control unit 48. In the battery monitoring system 101 of the second embodiment, Battery Monitoring The device 31 differs in that a switching unit 46 is provided between the connection units 34, 36 and the receiving unit 42 and transmitting unit 44. However, the second embodiment operates in the same way as the first embodiment, and like the first embodiment, it is possible to suppress the increase in frequency error and synchronize the frequency of the second clock signal at low cost.

[0048] Third embodiment: FIG. 7 is a schematic diagram of a battery monitoring system 102 according to the third embodiment. In the battery monitoring system 102 according to the third embodiment, the battery monitoring device 32 includes a transceiver 43 instead of the receiver 42 and the transmitter 44. Battery Monitoring ECU10 and multiple Battery Monitoring The device 32 is similar to the first embodiment in that it is daisy-chained. Battery Monitoring This is different from the system 100. The battery monitoring device 32 has two connection parts 34, 36, and the terminal device 28 is connected to the connection part 36 of the battery monitoring device 32 in the last stage, the m-th stage. Depending on the configuration of the transmission / reception unit 43, the terminal device 28 may not be connected to the connection part 36. In the first embodiment, the connection part 34 is used as the input part and the connection part 36 is used as the output part, but in the third embodiment, the connection part 34 functions as the input part and the connection part 36 functions as the output part, but it is possible to switch so that the connection part 36 also functions as the input part and the connection part 34 also functions as the output part. In the correction mode, the first superimposed signal is transmitted to the first stage, as in the first embodiment. Battery Monitoring From device 32 to the final stage Battery Monitoring The third embodiment also operates in the same manner as the first embodiment in the correction mode, and like the first embodiment, it is possible to suppress the increase in frequency error and synchronize the frequency at low cost. In the measurement mode, the second superimposed signal on which the measurement result is superimposed is transmitted to the final stage. Battery Monitoring After being transmitted to the device 32, the final stage Battery Monitoring From device 32 in reverse order, Battery Monitoring The signal is then transmitted to the device 32 and then to the battery monitoring ECU 10 .

[0049] Fourth embodiment: 8 is a schematic configuration diagram of a battery monitoring system 103 of the fourth embodiment. In the battery monitoring system 103 of the fourth embodiment, a plurality of battery monitoring devices 33 are multi-drop connected to a battery monitoring ECU 11. The transmitter / receiver 16 of the battery monitoring ECU 11 is connected to a transmission path 27 via a connection 18. In each battery monitoring device 33, the receiver 42 and transmitter 44 are connected to one connection 34, and the connection 34 is connected to the transmission path 27.

[0050] In the battery monitoring system 103 of the fourth embodiment, Battery Monitoring A signal from the ECU 11 is transmitted to the first stage via the connection portion 18 and the transmission path 27. Battery monitoring device 33 The signal is transmitted to the receiver 42 of the first stage. Battery monitoring device 33 The signal output from the second stage is transmitted to the second stage via the transmission section 44, the connection section 34, and the transmission line 27. Battery monitoring device 33 The signal is then transmitted to the receiving unit 42 of the xth stage in the same manner. Battery monitoring device 33 The signal output from the (x+1)th stage is transmitted to the (x+1)th stage via the transmission unit 44, the connection unit 34, and the transmission line 27. Battery monitoring device 33 The mth stage of the final stage is transmitted to the receiving unit 42. Battery monitoring device 33 The signal output from the Battery Monitoring The signal is transmitted to the transmitting / receiving unit 16 of the ECU 11. Battery Monitoring The device 30 sequentially transmits the superimposed signal using the same transmission path 27. For the transmission, each Battery Monitoring The device 30 then has the right to use the transmission line 27 and transmits the superimposed signal to the subsequent stage.

[0051] In the fourth embodiment, the operation is the same as in the first embodiment, and similarly to the first embodiment, the increase in frequency error can be suppressed and the frequency can be synchronized at low cost.

[0052] As can be seen from the first to fourth embodiments, the battery monitoring ECU and the Battery Monitoring The devices can be connected in various configurations, such as a ring connection, a daisy chain connection, and a multi-drop connection.

[0053] Fifth embodiment: FIG. 9 shows a first superimposed signal transmitted by the battery monitoring ECU 10 in the correction mode according to the fifth embodiment, and each Battery Monitoring FIG. 11 is an explanatory diagram showing a first superimposed signal received and transmitted by the device 30. When the first superimposed signal passes through the selector 47 of the switching unit 46, the voltage drops due to the on-resistance of the selector 47. Battery MonitoringThe signal level of the first superimposed signal is set high so as to exceed the signal level that can be received by the receiving unit 42 of the device 30. As a result, the signal level of the first superimposed signal is Battery Monitoring The power decreases with each pass through the device 30, but the power Battery Monitoring The receiver 42 of the device 30 can also detect the signal level.

[0054] Sixth embodiment: FIG. 10 shows a first superimposed signal transmitted by the battery monitoring ECU 10 in the correction mode according to the sixth embodiment, and each Battery Monitoring FIG. 13 is an explanatory diagram showing a first superimposed signal received and transmitted by the device 30. When the first superimposed signal passes through the selector 47 of the switching unit 46, the pulse width is narrowed by the H / L determination threshold value in the selector 47. Battery Monitoring The pulse width of the first superimposed signal is set to be wide so as to exceed the pulse width level that can be detected by the receiving unit 42 of the device 30. As a result, the pulse width of the first superimposed signal is set to be wide at each stage. Battery Monitoring It gets narrower with each pass through the device 30, but the final stage Battery Monitoring The receiving section 42 of the device 30 can also detect the pulse.

[0055] In each of the above embodiments, the battery monitoring unit 54 monitors the battery using the corrected second clock, but monitoring may also be performed without using the second clock, or monitoring may be performed using the uncorrected second clock.

[0056] The present disclosure is not limited to the above-mentioned embodiments, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features in each embodiment corresponding to the technical features in the form described in the Summary of the Invention column can be appropriately replaced or combined in order to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if the technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0057] 10, 11… Battery Monitoring ECU, 12...first clock generating unit, 14...control unit, 16...transmitting / receiving unit, 18, 20...connecting unit, 22, 24, 25, 26, 27...transmission path, 28...terminating device, 30, 31, 32, 33... Battery Monitoring Device, 34, 36...connection unit, 40...battery monitoring IC, 42...receiving unit, 43...transmitting / receiving unit, 44...transmitting unit, 46...switching unit, 47...selector, 48...control unit, 50...second clock generating unit, 52...frequency correction unit, 54...battery monitoring unit, 60...filter, 100, 101, 102, 103... Battery Monitoring system

Claims

1. A battery monitoring system (100) for monitoring a battery state of a plurality of batteries, comprising: A battery monitoring ECU (10); A plurality of battery monitoring devices (30), the battery monitoring ECU and the plurality of battery monitoring devices are connected in any one of a ring connection, a daisy chain connection, and a multi-drop connection, and each of the plurality of battery monitoring devices (30) is connected such that one battery monitoring device is in a preceding-stage / rear-stage relationship with another battery monitoring device, The battery monitoring ECU A clock generating unit (12) that generates a first clock signal; a transceiver unit (16) that outputs the first clock signal and an instruction related to monitoring of the battery to at least one of the battery monitoring devices and receives a result of the instruction from at least one of the battery monitoring devices; The battery monitoring device includes: a receiving unit (42) for receiving a signal from the battery monitoring ECU corresponding to the preceding stage or the other battery monitoring device; A second clock generating unit (50) that generates a second clock signal that is a reference for its own operation; a frequency correction unit that corrects a frequency of the second clock signal; a battery monitoring unit (54) that monitors the battery using the second clock signal; a control unit (48) that, when an instruction regarding the monitoring of the battery included in a signal received via the receiving unit from the battery monitoring ECU corresponding to a previous stage or the other battery monitoring device is an instruction to correct the second clock signal, causes the frequency correction unit to correct the frequency of the second clock signal to be synchronized with the frequency of the first clock signal, and causes the battery monitoring unit to perform the monitoring using the corrected second clock signal; A transmitter (44) that outputs a signal including the result of monitoring the battery; a switching unit (46) that switches so as to output a signal sent from a previous stage to a subsequent stage when an instruction to correct the second clock signal is received, and otherwise to output a signal including the monitoring result of the battery to the subsequent stage; Equipped with Battery monitoring system.

2. 2. The battery monitoring system according to claim 1, A battery monitoring system in which the switching unit of the battery monitoring device receives instructions from the battery monitoring ECU and switches the circuit configuration to a state in which a signal sent from a previous stage is output to a subsequent stage, or switches the circuit configuration to a state in which a signal including the monitoring result generated in the current stage is output to a subsequent stage.

3. 2. The battery monitoring system according to claim 1, A battery monitoring system in which the switching unit receives an instruction to correct the frequency of the second clock signal from the battery monitoring ECU, and during the period in which the correction instruction is received, switches the circuit configuration to a state in which a signal sent from the previous stage is output to the subsequent stage, and during other periods, switches the circuit configuration to a state in which a signal including the battery monitoring result generated in the current stage is output to the subsequent stage.

4. The battery monitoring system according to claim 2 or 3, The frequency correction unit detects a difference in frequency between the first clock signal and the second clock signal received from a previous stage, and corrects the frequency of the second clock signal.

5. The battery monitoring system according to claim 4, A battery monitoring system, wherein the frequency correction unit detects a frequency discrepancy between the first clock signal and the second clock signal using one of a counter method, a phase-locked loop method, and a delay-locked loop method that uses a count difference between the signal received from a previous stage and the second clock signal.

6. The battery monitoring system according to any one of claims 1 to 5, The switching unit is provided upstream of the receiving unit and downstream of the transmitting unit.

7. A battery monitoring system as claimed in claim 1, A battery monitoring system in which the transceiver unit outputs the signal level of the first clock signal at a magnitude that is a signal level that can be detected even by the battery monitoring device of the last stage, based on the degree of attenuation due to passing through the battery monitoring device and the number of combinations of the previous and subsequent stages.

8. A battery monitoring system as claimed in claim 1, A battery monitoring system in which the transceiver unit outputs the pulse width of the first clock signal at a pulse width that is greater than or equal to the pulse width detectable by the battery monitoring device of the last stage, based on the degree to which the pulse width narrows due to passing through the battery monitoring device and the number of combinations of the previous and subsequent stages.

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