Anomaly diagnosis system, anomaly diagnosis device, and anomaly diagnosis method

Abstract

To detect abnormality of configuration for detecting a state of a secondary battery.SOLUTION: An abnormality diagnostic system comprises: a discharge control unit for controlling a switch of a discharge unit that discharges a secondary battery when the switch and a resistor element connected to the secondary battery is connected in series and the switch is turned on; a measuring unit for measuring a current flowing from the secondary battery and a voltage of the secondary battery; and a determination unit for determining abnormality of the discharge unit on the basis of a current value measured by the measuring unit when the switch is turned off and a current value measured by the measuring unit when the switch is turned on.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an abnormality diagnosis system, an abnormality diagnosis apparatus, and an abnormality diagnosis method.

Background Art

[0002] As inventions related to the detection of the state of a rechargeable battery (hereinafter referred to as a secondary battery), for example, there are a deterioration determination device disclosed in Patent Document 1 and a state detection device disclosed in Patent Document 2. The deterioration determination device disclosed in Patent Document 1 obtains an internal impedance from a response voltage and a current when the secondary battery is discharged, and determines the degree of deterioration of the secondary battery from the obtained internal impedance.

[0003] The state detection device disclosed in Patent Document 2 is a device that detects the state of a secondary battery by intermittent discharge of the secondary battery. This state detection device aims to detect a decrease in the measurement accuracy of current. By turning on and off a switch in which a resistor element is connected in series, the secondary battery is discharged, and the current value of the current flowing through the resistor element when the switch is on is acquired. The current value of the current flowing through the resistor element is estimated from the voltage of the secondary battery and the resistance value of the resistor element stored, and when the estimated current value and the acquired current value differ by a predetermined value or more, it is determined that the current measurement is abnormal.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In devices that detect the state of a secondary battery by discharge, if there is an abnormality in the circuit for discharging the secondary battery, the voltage and current values ​​due to discharge cannot be accurately obtained, leading to an incorrect estimation of the secondary battery's state. The state detection device disclosed in Patent Document 2 can determine abnormalities in current measurement, but it does not determine abnormalities in the discharge circuit, so there is a risk of incorrect detection of the secondary battery's state if there is an abnormality in the discharge circuit.

[0006] The present invention has been made in view of the above, and aims to detect abnormalities in the configuration for detecting the state of a secondary battery. [Means for solving the problem]

[0007] To solve the above-mentioned problems and achieve the objective, an abnormality diagnosis system according to one aspect of the present invention comprises: a discharge control unit that controls the switch of a discharge unit which discharges the secondary battery when the switch is ON, and which has a switch connected to a secondary battery and a resistive element connected in series; a measurement unit that measures the current flowing from the secondary battery and the voltage of the secondary battery; and a determination unit that determines an abnormality in the discharge unit based on the current value measured by the measurement unit when the switch is OFF and the current value measured by the measurement unit when the switch is ON.

[0008] In an abnormality diagnosis system according to one aspect of the present invention, the determination unit may determine an abnormality in the measurement unit based on the voltage value measured by the measurement unit when the switch is on, the current value flowing through the resistive element when the switch is on, calculated from the voltage value measured by the measurement unit when the switch is on and the resistance value of the resistive element, and the current value measured by the measurement unit when the switch is on.

[0009] In one aspect of the present invention, an abnormality diagnosis system may be provided in which, if the determination unit determines that there is no abnormality in the discharge unit and the measurement unit, the discharge control unit discharges the secondary battery in a predetermined discharge pattern, and the system calculates the internal resistance value of the secondary battery from the voltage and current measured by the measurement unit while the discharge is being performed in the predetermined discharge pattern.

[0010] In an abnormality diagnosis system according to one aspect of the present invention, if the determination unit determines that there is an abnormality in the discharge unit and the measurement unit, the internal resistance calculation unit may refrain from calculating the internal resistance value.

[0011] In an abnormality diagnosis system according to one aspect of the present invention, the measurement unit has an AD converter connected to the secondary battery, and the determination unit may not determine an abnormality in the discharge unit if there is an abnormality in the AD converter.

[0012] An abnormality diagnosis device according to one aspect of the present invention comprises: a discharge control unit that controls the switch of a discharge unit which discharges the secondary battery when the switch is ON, and which has a switch connected to a secondary battery and a resistive element connected in series; a measurement unit that measures the current flowing from the secondary battery and the voltage of the secondary battery; and a determination unit that determines an abnormality in the discharge unit based on the current value measured by the measurement unit when the switch is OFF and the current value measured by the measurement unit when the switch is ON.

[0013] An abnormality diagnosis method according to one aspect of the present invention comprises: a discharge control step of controlling the switch of a discharge unit that discharges the secondary battery when the switch is ON, wherein the switch and a resistive element connected in series are connected to the secondary battery; a measurement step of measuring the current flowing from the secondary battery and the voltage of the secondary battery; and a determination step of determining an abnormality in the discharge unit based on the current value measured in the measurement step when the switch is OFF and the current value measured in the measurement step when the switch is ON. [Effects of the Invention]

[0014] The present invention has the effect of being able to detect abnormalities in the configuration for detecting the state of a secondary battery. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 shows the power supply system of a vehicle according to an embodiment. [Figure 2] Figure 2 is a block diagram showing the configuration of the diagnostic device. [Figure 3] Figure 3 is a block diagram showing the configuration of the functions realized in the control unit. [Figure 4] Figure 4 is a flowchart showing the flow of the process executed by the control unit. [Figure 5] Figure 5 is a flowchart showing the flow of the process executed by the control unit. [Figure 6] Figure 6 is a time chart of the test discharge process. [Figure 7] Figure 7 is a flowchart showing the flow of the process executed by the control unit. [Figure 8] Figure 8 is a flowchart showing the flow of the process executed by the control unit. [Figure 9] Figure 9 is a diagram showing the power supply system of a vehicle according to another embodiment. [Figure 10] Figure 10 is a diagram showing the configuration of an ECU according to a modification. [Figure 11] Figure 11 is a diagram showing the configuration of a server device according to a modification.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described in detail based on the drawings. Note that the present invention is not limited by the embodiments described below. Also, in the description of the drawings, the same or corresponding elements are appropriately assigned the same reference numerals.

[0017] [Embodiment] (Configuration of the Embodiment) Figure 1 shows a power supply system for a vehicle 2A according to an embodiment of the present invention. The secondary battery 20 is a rechargeable battery having an electrolyte, and is composed of, for example, a lead-acid battery, a lithium-ion battery, a nickel-cadmium battery, or a nickel-metal hydride battery. The secondary battery 20 is charged by the alternator 25, drives the starter motor 27, and supplies power to the load 28. The starter motor 27 is composed of, for example, a DC motor, generates rotational force with power supplied from the secondary battery 20, and starts the engine 26. The engine 26 is composed of, for example, a reciprocating engine such as a gasoline engine or a diesel engine, or a rotary engine. The engine 26 is started by the starter motor 27, drives the drive wheels via the transmission, provides propulsion to the vehicle 2A, and drives the alternator 25. The alternator 25 is driven by the engine 26 to generate AC power, and converts the generated AC power into DC power by a rectifier circuit to charge the secondary battery 20. The load 28 consists of, for example, an electric steering motor, a defogger, a seat heater, an ignition coil, a car audio system, and a car navigation system, and operates using power supplied from the secondary battery 20.

[0018] The switch SW1 and resistor R1, connected in series, constitute a discharge circuit 21A that discharges the secondary battery 20 in a predetermined discharge pattern. Here, the "predetermined discharge pattern" has a predetermined discharge current and a predetermined discharge time. The switch SW1 is composed of a semiconductor switch such as an FET (Field Effect Transistor) or IGBT (Insulated Gate Bipolar Transistor), or an electromagnetic switch such as a relay. One end of the switch SW1 is connected to the positive terminal of the secondary battery 20, and the other end is connected to the resistor R1. One end of the resistor R1 is connected to the switch SW1, and the other end is connected to terminal T3 of the diagnostic device 1 and grounded. The switch SW1 is turned on or off in response to a control signal supplied from terminal T4 of the diagnostic device 1. When the switch SW1 is on, it discharges the secondary battery 20, and when the switch SW1 is off, it stops the discharge of the secondary battery 20. When the switch SW1 is turned on, a predetermined discharge current flows from the secondary battery 20 to the resistor R1.

[0019] The resistive element R2 has one end connected to terminal T2 of the diagnostic device 1 and the negative terminal of the secondary battery 20, and the other end connected to terminal T3 of the diagnostic device 1 and grounded. The resistive element R2 constitutes a current sensor and generates a voltage corresponding to the current flowing through it, which is supplied to terminals T2 and T3 of the diagnostic device 1. By converting the voltage generated in this resistive element R2 with the AD converter 13 described later, the current flowing through the resistive element R2 can be determined. The diagnostic device 1 also functions as a voltage sensor by converting the voltage applied to terminals T1 and T2 with the AD converter 13 described later, and detects the voltage of the secondary battery 20.

[0020] Diagnostic device 1, an example of an abnormality diagnosis device for detecting the state of a secondary battery 20, discharges the secondary battery 20 in a predetermined discharge pattern by controlling switch SW1 on and off with a control signal output from terminal T4. Diagnostic device 1 determines the internal resistance value of the secondary battery 20 from the voltage and current measured when the battery is being discharged in this predetermined discharge pattern, and detects the state of the secondary battery 20 based on the determined internal resistance value. Note that instead of having diagnostic device 1, discharge circuit 21A, resistance element R2, and temperature sensor 23 as separate configurations, a configuration in which some or all of these are combined may also be used as the diagnostic device.

[0021] Figure 2 is a block diagram showing an example of the configuration of the diagnostic device 1. The diagnostic device 1 includes a control unit 10 containing a CPU (Central Processing Unit) 10a, a ROM (Read Only Memory) 10b, and a RAM (Random Access Memory) 10c, a storage unit 11, a communication unit 12, an AD converter 13, and a bus 14. The control unit 10 may be configured with a DSP (Digital Signal Processor), FPGA (Field Programmable Gate Array), or ASIC (Application Specific Integrated Circuit) instead of the CPU 10a. Here, each element of the diagnostic device 1 (control unit 10, storage unit 11, communication unit 12, AD converter 13) does not need to be grouped together; for example, each element may be distributed inside the vehicle 2 as an abnormality diagnosis system.

[0022] Bus 14 is a group of signal lines that interconnect the CPU 10a, ROM 10b, RAM 10c, memory unit 11, communication unit 12, and AD converter 13, enabling the exchange of information between them. The memory unit 11 is composed of non-volatile memory and stores, for example, the resistance values ​​of resistors R1 and R2, and various threshold values ​​described later. The AD converter 13 is a converter that converts analog signals into digital signals, converting the voltages of terminals T1-T3 into digital signals. The communication unit 12 communicates with the ECU (Electronic Control Unit) 3, which is a higher-level device that controls the main drive system of the vehicle 2A, and notifies the ECU 3 of various information.

[0023] ROM 10b is composed of non-volatile semiconductor memory and stores the program 10ba, etc. RAM 10c is composed of semiconductor memory and stores data generated when the CPU 10a executes the program 10ba, various measurement results, and various values ​​calculated by the CPU 10a using the measurement results.

[0024] The CPU 10a controls each part based on the program 10ba stored in the ROM 10b. The functions of the control unit 10 are realized as a functional unit when the CPU 10a reads and executes the program 10ba from the ROM 10b.

[0025] Figure 3 is a functional block diagram showing the configuration of the functions realized in the control unit 10 when the CPU 10a executes the program 10ba. The control unit 10 includes a discharge control unit 101, a measurement unit 102, a determination unit 103, an internal resistance calculation unit 104, and a state detection unit 105.

[0026] The discharge control unit 101 controls the state of switch SW1 by outputting a signal from terminal T4 to turn SW1 ON or OFF. Furthermore, when calculating the internal resistance of the secondary battery 20, the discharge control unit 101 outputs a control signal from terminal T4 to discharge the secondary battery 20 in a predetermined discharge pattern. The measurement unit 102 measures the current flowing from the secondary battery 20 and the voltage of the secondary battery 20 using the resistance values ​​of resistor element R1 and resistor element R2, based on the AD conversion results performed by the AD converter 13. The determination unit 103 determines whether there is an abnormality in the discharge circuit 21A or an abnormality in the current measurement of the secondary battery 20 based on the measurement results from the measurement unit 102. The internal resistance calculation unit 104 calculates the internal resistance of the secondary battery 20 based on the measurement results from the measurement unit 102 when the discharge control unit 101 outputs a control signal. The state detection unit 105 detects the state of the secondary battery 20 based on the internal resistance value calculated by the internal resistance calculation unit 104. The discharge control unit 101, measurement unit 102, and determination unit 103 function as an abnormality diagnosis system.

[0027] (Example of operation of the embodiment) Next, an example of operation of this embodiment will be described. Figure 4 is a flowchart showing the flow of processing performed by the control unit 10 when measuring the internal resistance value of the secondary battery 20. The processing shown in Figure 4 is performed periodically, for example, every time the ignition is turned off, every few days, every few weeks, or every few months. Note that the processing shown in Figure 4 may also be performed upon request from the user or irregularly.

[0028] First, the control unit 10 controls the switch SW1 to perform a test discharge of the secondary battery 20 (step S101). Step S101 is an example of a discharge control step. Figure 5 shows the flow of processing performed by the control unit 10 in step S101. Figure 6 shows the time chart for the processing in step S101. Figure 6(a) shows the on / off state of switch SW1 by the control signal output from terminal T4, and Figure 6(b) shows the current measured by the control unit 10.

[0029] First, the control unit 10 turns off the switch SW1 as shown in Figure 6(a) (step S201). Next, the control unit 10 measures a reference current value, which is the reference value of the current flowing from the secondary battery 20 when the switch SW1 is off (step S202). In Figure 6(b), the current flowing from the secondary battery 20 when the switch SW1 is off is I1. Note that in Figure 6(b), the case when the secondary battery 20 is being charged is defined as positive, and the case when the secondary battery 20 is being discharged is defined as negative, so when a discharge current flows, the current flows in the negative direction. Here, the control unit 10 calculates the current value of the current flowing through the resistor R2 from the resistance value of the resistor R2 stored in the memory unit 11 and the voltage applied to the resistor R2 converted by the AD converter 13, and uses the calculated current value as the reference current value. Specifically, the control unit 10 measures the voltage applied to the resistor R2 multiple times at a predetermined period, calculates the current value for each measured voltage, and uses the average value of the calculated current values ​​as the reference current value.

[0030] Next, the control unit 10 measures the off-current value, which is the current value of the current flowing from the secondary battery 20 after step S202 when the switch SW1 is off (step S203). Here, the control unit 10 calculates the current value of the current flowing through the resistor R2 from the resistance value of the resistor R2 stored in the memory unit 11 and the voltage applied to the resistor R2 converted by the AD converter 13, and sets the calculated current value as the off-current value. Specifically, the control unit 10 measures the voltage applied to the resistor R2 multiple times at predetermined intervals, calculates the current value for each measured voltage, and sets the average value of the calculated current values ​​as the off-current value. Here, if the voltage fluctuates after step S202, for example due to the load 28, the off-current value will be a different value from the reference current value.

[0031] Next, the control unit 10 turns on the switch SW1 as shown in Figure 6(a) (step S204). The control unit 10 measures the on-current value, which is the current value of the current flowing from the secondary battery 20 when the switch SW1 is on, as shown in Figure 6(b) (step S205). Here, the control unit 10 calculates the current value of the current flowing through the resistor R1 from the resistance value of the resistor R1 stored in the memory unit 11 and the voltage applied to the resistor R1 converted by the AD converter 13, and sets the calculated current value as the on-current value. Specifically, the control unit 10 measures the voltage applied to the resistor R1 multiple times at predetermined intervals, calculates the current value for each measured voltage, and sets the average value of the calculated current values ​​as the on-current value. Although a voltage is also generated at the resistor R2, the resistance value of the resistor R2 is negligibly small compared to the resistance value of the resistor R1, and the voltage generated at the resistor R2 can be ignored. Therefore, the on-current value may be calculated using the voltage of the secondary battery 20 instead of the voltage applied to the resistor R1.

[0032] Next, as shown in Figure 6(a), the control unit 10 measures the on-voltage value, which is the voltage across the resistor R1 when the switch SW1 is ON (step S206). Here, the control unit 10 uses the voltage across the resistor R1 converted by the AD converter 13 as the on-voltage value. Next, as shown in Figure 6(a), the control unit 10 turns off the switch SW1 (step S207), ending the test discharge process. The steps of measuring the reference current value, measuring the off-current value, measuring the on-current value, and measuring the on-voltage in the process of Figure 5 are examples of measurement steps.

[0033] Returning to Figure 4, the control unit 10 then determines whether there is any abnormality in the AD converter 13 (step S102). Here, the control unit 10 determines that there is an abnormality in the AD converter 13 if, for example, the output value of the AD converter 13 was outside the range when measuring the voltage in step S101, or if the AD conversion did not finish within a predetermined time and timed out (NO in step S102). Also, the control unit 10 determines that there is no abnormality in the AD converter 13 if no range over or timeout occurred in the AD converter 13 (YES in step S102). If there is an abnormality in the AD converter 13, the control unit 10 terminates the process shown in Figure 4. Note that the control unit 10 may skip the process in step S102 and perform the process in step S103 after step S101.

[0034] If there is no abnormality in the AD converter 13, the control unit 10 diagnoses the discharge circuit 21A (step S103). Figure 7 shows the processing flow performed by the control unit 10 in step S103. First, the control unit 10 determines whether the off-current value measured in step S203 is within a predetermined range (step S301). Here, for example, if threshold A < (off-current value - reference current value), the control unit 10 determines that it is within the predetermined range (NO in step S301), and if threshold A ≥ (off-current value - reference current value), it determines that it is outside the predetermined range (YES in step S301). If the control unit 10 determines in step S301 that it is outside the predetermined range, it turns on the first flag (step S304). The control unit 10 also counts the number of times the first flag has been turned on. The threshold A is a value determined in advance by experiment.

[0035] If the control unit 10 determines in step S301 that the value is within a predetermined range, it determines in step S205 whether the measured ON current value is within the predetermined range (step S302). Here, for example, if threshold C ≤ (ON current value - reference current value) ≤ threshold D, the control unit 10 determines that the value is within the predetermined range (YES in step S302), and if threshold C ≤ (ON current value - reference current value) ≤ threshold D is not true, it determines that the value is outside the predetermined range (NO in step S302). Alternatively, the control unit 10 may determine that the value is within the predetermined range if threshold E ≤ ON current value ≤ threshold F is true (YES in step S302), and if threshold E ≤ ON current value ≤ threshold F is not true, it may determine that the value is outside the predetermined range (NO in step S302). The thresholds C, D, E, and F are values ​​determined in advance by experiment. If the control unit 10 determines in step S302 that the value is outside the predetermined range, it turns on the first flag (step S304). Furthermore, the control unit 10 counts the number of times the first flag has been turned on. Also, if the control unit 10 determines in step S302 that the number is within a predetermined range, it turns off the first flag (step S303).

[0036] Returning to Figure 4, the control unit 10 then performs a current abnormality diagnosis (step S104). Figure 8 shows the processing flow performed by the control unit 10 in step S104. First, the control unit 10 obtains the resistance value of the resistor R1 from the storage unit 11 (step S401). If the resistance value of the resistor R1 is temperature dependent, the resistance value of the resistor R1 may be corrected based on the temperature measured by the temperature sensor 23. For example, it is possible to store the temperature coefficient in the storage unit 11 and correct the resistance value by multiplying the temperature T by this temperature coefficient. Of course, if the temperature coefficient is sufficiently small, the change in resistance value due to temperature may be ignored.

[0037] Next, the control unit 10 calculates the estimated current value Ie by dividing the ON voltage measured in step S206 by the resistance value obtained in step S401 (step S402). The control unit 10 also calculates ΔI (=|ON current value - estimated current value Ie|), which is the absolute value of the difference between the ON current value measured in step S205 and the estimated current value Ie calculated in step S402 (step S403).

[0038] Next, the control unit 10 determines whether the calculated ΔI is greater than or equal to a predetermined threshold (step S404). If ΔI is greater than or equal to the threshold (YES in step S404), the control unit 10 turns on the second flag (step S405). The threshold used in step S405 is a value determined in advance through experimentation. The control unit 10 also counts the number of times the second flag has been turned on. If ΔI is less than the threshold (YES in step S404), the control unit 10 turns off the second flag (step S406).

[0039] Returning to Figure 4, the control unit 10 then determines whether the diagnostic results of step S103 and step S104 are normal (step S105). The processes in steps S103 and S105 are an example of a determination step. Here, the control unit 10 determines that there is an abnormality in the diagnostic results if at least one of the first flag and the second flag is on (NO in step S105). If the diagnostic results are abnormal, the control unit 10 determines whether the diagnostics in step S103 and step S104 have been performed a predetermined number of times (step S106). The predetermined number of times is, for example, any number of 1 or more. If the number of diagnostics has not reached the predetermined number (NO in step S106), the control unit 10 returns to step S101.

[0040] If the number of diagnoses has reached a predetermined number (YES in step S106), the control unit 10 determines whether the number of times the discharge circuit 21A has been determined to be abnormal is the predetermined number (step S107). Here, if the number of times the first flag was turned on in step S304 is the predetermined number (YES in step S107), the control unit 10 turns on the discharge circuit abnormality flag (step S108) and moves the process flow to step S109. If the number of times the first flag was turned on in step S304 is less than the predetermined number (NO in step S107), the control unit 10 skips the process in step S108 and moves the process flow to step S109.

[0041] Next, the control unit 10 determines whether the number of times it has determined there is a current abnormality is the predetermined number (step S109). Here, if the number of times the second flag was turned on in step S405 is the predetermined number (YES in step S109), the control unit 10 turns on the current abnormality flag (step S110) and terminates the process shown in Figure 4. If the number of times the second flag was turned on in step S405 is less than the predetermined number (NO in step S109), the control unit 10 terminates the process shown in Figure 4 without performing the process in step S110.

[0042] Furthermore, the control unit 10 may notify the ECU 3 of the occurrence of an abnormality as an alert if the discharge circuit abnormality flag or current abnormality flag is turned on. As a result, the ECU 3 can notify the user of the occurrence of the abnormality, for example, by displaying it on the instrument panel or by sounding it through a speaker. The ECU 3 may also perform a fail-safe operation when it is notified of the occurrence of an abnormality by the control unit 10. In addition, if the ECU 3 has control using internal resistance, it may switch the control, such as stopping the control using internal resistance, when it is notified of the occurrence of an abnormality by the control unit 10.

[0043] Returning to step S105, the control unit 10 determines that there is no abnormality in the diagnosis result if both the first flag and the second flag are off (YES in step S105). If the control unit 10 determines YES in step S105, it turns off the discharge circuit abnormality flag and the current abnormality flag (step S111). Next, the control unit 10 measures the internal resistance value of the secondary battery 20 (step S112). Here, the control unit 10 measures the voltage and current of the secondary battery 20 when the secondary battery 20 is discharged in a predetermined discharge pattern, for example by alternately turning the switch SW1 on and off, and determines the internal resistance value of the secondary battery 20 from the measurement results. The control unit 10 may also notify the ECU 3 that there is no abnormality if both the discharge circuit abnormality flag and the current abnormality flag are off. The control unit 10 can detect the state of the secondary battery 20 based on the internal resistance value measured in step S112.

[0044] According to this embodiment, in order to determine whether or not there is an abnormality in the discharge circuit 21A for detecting the state of the secondary battery 20, it is possible to detect abnormalities in the configuration for detecting the state of the secondary battery 20. Furthermore, according to this embodiment, the presence or absence of an abnormality in the discharge circuit 21A is diagnosed in step S103, and if there is an abnormality in the discharge circuit 21A, the measurement of the internal resistance value is not performed, thus avoiding detection of the state when there is an abnormality. In addition, since the voltage value and current value when there is an abnormality are not used for measuring the internal resistance value, it is possible to avoid detecting the state of the secondary battery 20 with inaccurate measurement results, thereby improving the accuracy of detecting the state of the secondary battery 20. Furthermore, according to this embodiment, the abnormality of the discharge circuit 21A is notified to the ECU 3, and the ECU 3 can notify the user of the occurrence of the abnormality through a display on the instrument panel or an audible sound from the speaker. Note that if there is processing in the ECU 3 that uses the internal resistance value, it may be configured to switch to processing that takes into account the abnormality of the secondary battery 20 in response to notification from the control unit 10.

[0045] [Other embodiments] Figure 9 shows the power supply system of vehicle 2B according to another embodiment of the present invention. Vehicle 2B differs from vehicle 2A in that it further includes a discharge circuit 21B. The discharge circuit 21B is a circuit for discharging the secondary battery 20 and consists of a switch SW2 and a resistor R3 connected in series. Switch SW2 is composed of a semiconductor switch such as an FET or IGBT, or an electromagnetic switch such as a relay. One end of switch SW2 is connected to the positive terminal of the secondary battery 20, and the other end is connected to the resistor R3. One end of the resistor R3 is connected to switch SW2, and the other end is connected to terminal T3 of the diagnostic device 1 and grounded. Switch SW2 is turned on or off in response to a signal supplied from terminal T5 of the diagnostic device 1, and when switch SW2 is on, it discharges the secondary battery 20. When switch SW2 is turned on, a predetermined discharge current flows from the secondary battery 20 to the resistor R3.

[0046] The control unit 10 of vehicle 2B performs the test discharge process of step S101 on discharge circuits 21A and 21B, measuring the reference current value, off current value, on current value, and on voltage when switch SW1 of discharge circuit 21A is controlled, and the reference current value, off current value, on current value, and on voltage when switch SW2 of discharge circuit 21B is controlled. Furthermore, the control unit 10 of vehicle 2B diagnoses discharge circuit 21A in step S103 based on the measurement results of the test discharge of discharge circuit 21A, and diagnoses discharge circuit 21B in step S103 based on the measurement results of the test discharge of discharge circuit 21B.

[0047] If the control unit 10 detects an abnormality in one of the discharge circuits 21A and 21B and detects no abnormality in the other, it measures the internal resistance of the secondary battery 20 using the other discharge circuit. If both discharge circuits are detected as normal, the control unit 10 may periodically change the discharge circuits used for the test discharge in step S101 and the discharge circuit diagnosis in step S103 in the periodically executed process shown in Figure 4. Alternatively, the control unit 10 may perform the current abnormality diagnosis in step S104 based on the measurement results of the test discharge of discharge circuit 21A, and the current abnormality diagnosis in step S104 based on the measurement results of the test discharge of discharge circuit 21B.

[0048] Furthermore, the control unit 10 may determine that both discharge circuits are normal if the difference between the internal resistance value of the secondary battery 20 measured using discharge circuit 21A and the internal resistance value of the secondary battery 20 measured using discharge circuit 21B is within a predetermined range. This predetermined range is set in advance by checking the variation through testing. In addition, if the diagnostic result of one of the discharge circuits, discharge circuit 21A or discharge circuit 21B, is normal, the control unit 10 may determine that the other discharge circuit is normal if the measurement result of the internal resistance value measured using the other discharge circuit is within a predetermined range relative to the measurement result of the internal resistance value measured using the other discharge circuit.

[0049] Furthermore, if one discharge circuit is determined to be normal through test discharge and discharge circuit diagnosis, the other discharge circuit may also be determined to be normal if the difference between the measured reference current value, off current value, on current value, and on voltage and the reference current value, off current value, on current value, and on voltage measured in the discharge circuit determined to be normal is within a predetermined range.

[0050] [Differentiation] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above and can be implemented in various other forms. For example, the present invention may be implemented by modifying the embodiments described above as follows. The embodiments described above and the following modifications may be combined with each other. The present invention is also included in configurations that appropriately combine the components of each embodiment and each modification described above. Furthermore, further effects and modifications can be easily derived by those skilled in the art. Therefore, broader embodiments of the present invention are not limited to the embodiments and modifications described above, and various modifications are possible.

[0051] In the embodiment described above, it is also possible to determine whether the discharge circuit abnormality flag and the current abnormality flag have been turned off a predetermined number of times before step S111. If they have not been turned off a predetermined number of times, the process flow is returned to step S101. If they have been turned off a predetermined number of times, the processing from step S111 onwards is performed.

[0052] In the embodiments described above, the configuration may be such that the processes in steps S107 and S108 are not executed. Also, in the embodiments described above, the configuration may be such that the processes in steps S109 and S110 are not executed.

[0053] In the embodiment described above, the processing in step S103 and the processing in step S104 may be executed in parallel.

[0054] In the embodiment described above, if the result in step S105 is NO, the process in step S103, i.e., the process in Figure 7, is executed multiple times. However, the threshold value used in step S301 may be different each time it is executed.

[0055] In the embodiment described above, the off-current value may be measured multiple times in step S203. In this case, it may be determined whether the off-current value is within a predetermined range for each of the multiple off-current values ​​measured. Also, when multiple measurements of the off-current value and the on-current value are performed, it may be determined in step S105 whether the diagnostic result is normal based on the pattern of the determination results of these measurements. For example, if the pattern of the first off-current value being within the predetermined range, the second off-current value being within the predetermined range, and the on-current value being outside the predetermined range occurs for a predetermined number of consecutive times, it may be determined as NO in step S105, and the processing in steps S107 to S110 may be performed.

[0056] In the embodiment described above, if the cumulative number of times the diagnostic result in step S105 is found to be abnormal reaches a predetermined number, the processes in steps S107 to S110 may be executed. If the cumulative number of times the diagnostic result in step S105 is found to be abnormal is less than the predetermined number, the processes in steps S111 and S112 may be executed.

[0057] In the present invention, a determination may be made before step S103 whether or not to execute the processes from step S103 onward. For example, the control unit 10 may execute the processes from step S103 onward if the conditions that the ON voltage is abnormally high and the OFF current value is less than or equal to a predetermined value are met, and terminate the process shown in Figure 4 if these conditions are not met.

[0058] In the present invention, if the discharge circuit 21A is an IPD (Intelligent Power Device) having a semiconductor switch corresponding to switch SW1, the IPD may detect the state of its own semiconductor switch, and the control unit 10 may acquire the state of the semiconductor switch detected by the IPD. In this case, the control unit 10 may turn off the first flag if the acquired state indicates that the semiconductor switch is normal, and turn on the first flag if the acquired state indicates that the semiconductor switch is abnormal.

[0059] In the present invention, a current sensor for measuring a reference current value, an off-current value, and an on-current value, and a voltage sensor for measuring the voltage of the secondary battery 20 may be provided externally to the diagnostic device 1.

[0060] In the embodiment described above, the diagnostic device 1 provided in the vehicle 2A performs various diagnoses and measures the internal resistance value of the secondary battery 20, but these processes may also be performed by the ECU 3. Figure 10 is a block diagram showing the configuration of an embodiment in which the ECU 3 performs various diagnoses and detects the state of the secondary battery 20.

[0061] ECU3 has a control unit 30, a memory unit 31, a communication unit 32, and a bus (not shown). The control unit 30, like the control unit 10, has a CPU, ROM, and RAM. The control unit 30 may be configured with a DSP, FPGA, or ASIC instead of a CPU. The CPU, ROM, RAM, memory unit 31, and communication unit 32 are interconnected by a bus, and information is exchanged between them. The communication unit 32 communicates with the diagnostic device 1 and exchanges information with it. The memory unit 31 is composed of non-volatile memory and stores, for example, the resistance values ​​of resistors R1 and R2, and the various threshold values ​​mentioned above.

[0062] When the CPU executes a program stored in ROM, the control unit 30 realizes a determination unit 303, an internal resistance calculation unit 304, and a state detection unit 305. The determination unit 303 determines abnormalities in the discharge circuit 21A and abnormalities in the current measurement of the secondary battery 20 based on the measurement results of the measurement unit 102. The internal resistance calculation unit 304 calculates the internal resistance value of the secondary battery 20 based on the measurement results of the measurement unit 102 when the discharge control unit 101 outputs a control signal. The state detection unit 305 detects the state of the secondary battery 20 based on the internal resistance value calculated by the internal resistance calculation unit 304. The discharge control unit 101, measurement unit 102, and determination unit 303 function as an abnormality diagnosis system.

[0063] The control unit 10 transmits the reference current value, off current value, on current value, and on voltage measured in step S101 to the ECU 3. The control unit 30 receives the transmitted reference current value, off current value, on current value, and on voltage, and uses the received reference current value, off current value, on current value, and on voltage to perform the discharge circuit diagnosis process in step S103 and the current abnormality diagnosis process in step S104. If the diagnosis result in step S105 is normal, the control unit 30 transmits an instruction to the diagnostic device 1 to measure the internal resistance value of the secondary battery 20. If the diagnosis result in step S105 is abnormal, the control unit 30 transmits an instruction to the diagnostic device 1 to stop measuring the internal resistance value of the secondary battery 20. When the control unit 10 receives the measurement instruction, it performs the process in step S112 and transmits the measured voltage value and current value to the ECU 3. Also, when the control unit 10 receives the measurement stop instruction, it stops measuring the internal resistance value of the secondary battery 20. The control unit 30 calculates the internal resistance value of the secondary battery 20 based on the current value and voltage value transmitted from the control unit 10 in response to the measurement instruction, and detects the state of the secondary battery 20 based on the calculated internal resistance value.

[0064] In this configuration as well, since the presence or absence of abnormalities in the discharge circuit 21A for detecting the state of the secondary battery 20 is determined, abnormalities in the configuration for detecting the state of the secondary battery 20 can be detected. Furthermore, in this configuration as well, since the internal resistance value is not measured when there is an abnormality in the discharge circuit 21A, detection of the state when there is an abnormality can be avoided. In addition, since the voltage and current values ​​when there is an abnormality are not used for measuring the internal resistance value, detection of the state of the secondary battery 20 with inaccurate measurement results can be avoided, and the accuracy of detecting the state of the secondary battery 20 can be improved. Furthermore, the ECU 3 may be configured to perform a fail-safe operation when an abnormality in the discharge circuit 21A is detected. Furthermore, if the ECU 3 has control using internal resistance, it may switch control, such as stopping the control, when it detects an abnormality in the discharge circuit 21A.

[0065] In a configuration where the ECU3 has an AD converter, the control unit 30 may execute a program to realize the discharge control unit 101, measurement unit 102, determination unit 103, internal resistance calculation unit 104, and state detection unit 105, and the control unit 30 may perform the same processing as the control unit 10.

[0066] Furthermore, in this invention, a server device connected to a communication network may perform various diagnoses and measure the internal resistance value of the secondary battery 20. Figure 11 is a block diagram showing the configuration of an embodiment in which the server device 4 performs various diagnoses and detects the state of the secondary battery 20.

[0067] The server device 4 includes a control unit 40, a storage unit 41, a communication unit 42, and a bus (not shown). The control unit 40, like the control unit 10, includes a CPU, ROM, and RAM. The CPU, ROM, RAM, storage unit 41, and communication unit 42 are interconnected by the bus, and information is exchanged between them. The communication unit 42 communicates with the diagnostic device 1 via the communication network 1000, and exchanges information with the diagnostic device 1. The storage unit 41 stores, for example, the resistance values ​​of resistors R1 and R2, and the various threshold values ​​mentioned above. The server device 4 may also have a user interface including a mouse or keyboard for inputting information and a display device for displaying information.

[0068] When the CPU executes a program stored in ROM, the control unit 40 realizes a determination unit 403, an internal resistance calculation unit 404, and a state detection unit 405. The determination unit 403 determines whether there is an abnormality in the discharge circuit 21A or an abnormality in the configuration for measuring the current of the secondary battery 20 based on the measurement results of the measurement unit 102. The internal resistance calculation unit 404 calculates the internal resistance value of the secondary battery 20 based on the measurement results of the measurement unit 102 when the discharge control unit 101 outputs a control signal. The state detection unit 405 detects the state of the secondary battery 20 based on the internal resistance value calculated by the internal resistance calculation unit 404. The discharge control unit 101, measurement unit 102, and determination unit 403 function as an abnormality diagnosis system.

[0069] The control unit 10 transmits the reference current value, off current value, on current value, and on voltage measured in step S101 to the server device 4 via wireless communication from the communication unit 12 through the communication network 1000. The control unit 40 receives the transmitted reference current value, off current value, on current value, and on voltage, and uses the received reference current value, off current value, on current value, and on voltage to perform the discharge circuit diagnosis process in step S103 and the current abnormality diagnosis process in step S104. If the diagnosis result in step S105 is normal, the control unit 40 sends an instruction to the diagnostic device 1 to measure the internal resistance value of the secondary battery 20. If the diagnosis result in step S105 is abnormal, the control unit 40 sends an instruction to the diagnostic device 1 to stop measuring the internal resistance value of the secondary battery 20. When the control unit 10 receives the measurement instruction, it performs the process in step S112 and transmits the measured internal resistance value to the server device 4. Also, when the control unit 10 receives the measurement stop instruction, it stops measuring the internal resistance value of the secondary battery 20. The control unit 40 calculates the internal resistance value of the secondary battery 20 based on the current value and voltage value transmitted from the control unit 10 in response to the measurement instruction, and detects the state of the secondary battery 20 based on the calculated internal resistance value.

[0070] In this configuration as well, since the presence or absence of abnormalities in the discharge circuit 21A for detecting the state of the secondary battery 20 is determined, abnormalities in the configuration for detecting the state of the secondary battery 20 can be detected. Furthermore, in this configuration as well, since the internal resistance value is not measured when there is an abnormality in the discharge circuit 21A, it is possible to avoid detecting the state of the secondary battery 20 with inaccurate measurement results, thereby improving the accuracy of detecting the state of the secondary battery 20. In addition, the processing performed by the server device 4 may be executed by a terminal device such as a personal computer connected to the communication network 1000.

[0071] Furthermore, the server device 4 may store the received reference current value, off current value, on current value, and on voltage as history, and update various thresholds by learning the stored values. Also, when the diagnostic device 1 performs various diagnoses and measures the internal resistance value of the secondary battery 20, the thresholds stored in the diagnostic device 1 may be updated with the thresholds updated by the server device 4. By configuring the server device 4 to update the thresholds stored in the diagnostic device 1 at predetermined timings, the thresholds can be updated to values ​​suitable for diagnosis.

[0072] In the above-described embodiment, the vehicle 2A has the diagnostic device 1 and the discharge circuit 21A. However, mobile bodies such as motorboats and other vessels, drones and other aircraft, agricultural machinery, and construction machinery may also have the diagnostic device 1 and the discharge circuit 21A, and the diagnostic device 1 may perform the diagnosis of the discharge circuit 21A and measure the internal resistance value of the secondary battery in the vessel, aircraft, agricultural machinery, or construction machinery. Furthermore, the devices having the diagnostic device 1 and the discharge circuit 21A are not limited to mobile bodies. Devices using secondary batteries 20 in gas, water, railway, communication, and power facilities may also have the diagnostic device 1 and the discharge circuit 21A, and the diagnostic device 1 may perform the diagnosis of the discharge circuit 21A and measure the internal resistance value of the secondary battery.

[0073] In the embodiment described above, the vehicle 2 is configured so that only the engine 26 outputs driving force. However, the vehicle 2 may be, for example, a hybrid vehicle equipped with an electric motor to assist the engine 26, or an electric vehicle driven by an electric motor. In the case of a hybrid vehicle, the secondary battery 20 starts a high-voltage system (a system that drives the electric motor) composed of a lithium battery or the like, and the high-voltage system starts the engine 26. Also, if the vehicle 2 is an electric vehicle, the high-voltage system drives the electric motor to propel the vehicle. [Explanation of symbols]

[0074] 1. Diagnostic device Vehicles 2A and 2B 3 ECU 4 Server devices 10 Control Unit 11 Storage section 12 Communications Department 13 AD Converters 14 bus 20 Secondary battery 21A, 21B discharge circuit 101 Discharge Control Unit 102 Measuring section 103, 303, 403 Judgment section 104, 304, 404 Internal resistance calculation unit 105, 305, 405 State detection unit SW1, SW2 switches

Claims

1. A discharge control unit controls the switch in a discharge unit that discharges the secondary battery when the switch is ON, and the switch and a resistor are connected in series to the secondary battery. A measuring unit for measuring the current flowing from the secondary battery and the voltage of the secondary battery, A determination unit that determines an abnormality in the discharge unit based on the current value measured by the measurement unit when the switch is off and the current value measured by the measurement unit when the switch is on, Equipped with, The determination unit is an abnormality diagnosis system that determines an abnormality in the measurement unit based on the voltage value measured by the measurement unit when the switch is on, the resistance value of the resistance element, the current value flowing through the resistance element when the switch is on, and the current value measured by the measurement unit when the switch is on.

2. If the determination unit determines that there is no abnormality in the discharge unit and the measurement unit, the discharge control unit discharges the secondary battery in a predetermined discharge pattern, and the internal resistance calculation unit calculates the internal resistance value of the secondary battery from the voltage and current measured by the measurement unit while the discharge is being performed in the predetermined discharge pattern. The abnormality diagnosis system according to claim 1, comprising:

3. If the determination unit determines that there is an abnormality in the discharge unit or the measurement unit, the internal resistance calculation unit will not calculate the internal resistance value. The abnormality diagnosis system according to claim 2.

4. A discharge control unit that controls the switch of a discharge unit which discharges the secondary battery when the switch is ON, wherein the switch and a resistor are connected in series and the switch is connected to the secondary battery, A measuring unit for measuring the current flowing from the secondary battery and the voltage of the secondary battery, A determination unit that determines an abnormality in the discharge unit based on the current value measured by the measurement unit when the switch is off and the current value measured by the measurement unit when the switch is on, Equipped with, The measurement unit has an AD converter connected to the secondary battery, The determination unit does not determine if there is an abnormality in the AD converter. An anomaly detection system.

5. A discharge control unit controls the switch in a discharge unit that discharges the secondary battery when the switch is ON, and the switch and a resistor are connected in series to the secondary battery. A measuring unit for measuring the current flowing from the secondary battery and the voltage of the secondary battery, A determination unit that determines an abnormality in the discharge unit based on the current value measured by the measurement unit when the switch is off and the current value measured by the measurement unit when the switch is on, Equipped with, The determination unit is an abnormality diagnostic device that determines an abnormality in the measurement unit based on the voltage value measured by the measurement unit when the switch is on, the resistance value of the resistance element, the current value flowing through the resistance element when the switch is on, and the current value measured by the measurement unit when the switch is on.

6. A discharge control unit that controls the switch of a discharge unit which discharges the secondary battery when the switch is ON, wherein the switch and a resistive element connected in series are connected to the secondary battery, A measuring unit for measuring the current flowing from the secondary battery and the voltage of the secondary battery, A determination unit that determines an abnormality in the discharge unit based on the current value measured by the measurement unit when the switch is off and the current value measured by the measurement unit when the switch is on, Equipped with, The measurement unit has an AD converter connected to the secondary battery, The determination unit is an abnormality diagnosis device that does not determine an abnormality in the discharge unit if there is an abnormality in the AD converter.

7. A discharge control step controls the switch in a discharge unit that discharges the secondary battery when the switch is ON, in which a switch connected to a secondary battery and a resistive element are connected in series, A measurement step in which the current flowing from the secondary battery and the voltage of the secondary battery are measured by a measuring unit, A determination step in which an abnormality in the discharge section is determined based on the current value measured in the measurement step when the switch is off and the current value measured in the measurement step when the switch is on. Equipped with, The determination step is an abnormality diagnosis method that determines an abnormality in the measurement unit based on the voltage value measured in the measurement step when the switch is on, the resistance value of the resistive element, the current value flowing through the resistive element when the switch is on, and the current value measured in the measurement step when the switch is on.

8. A discharge control step that controls the switch of a discharge unit that discharges the secondary battery when the switch is ON, wherein the switch and a resistor element connected in series are connected to the secondary battery, A measurement step in which the current flowing from the secondary battery and the voltage of the secondary battery are measured by a measuring unit, A determination step in which an abnormality in the discharge section is determined based on the current value measured in the measurement step when the switch is off and the current value measured in the measurement step when the switch is on. Equipped with, The measurement unit has an AD converter connected to the secondary battery, The above determination step does not determine if there is an abnormality in the AD converter, or if there is an abnormality in the discharge unit. Methods for diagnosing abnormalities.

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