Battery control device, method, non-transitory computer-readable storage medium, and vehicle

Abstract

The present application discloses a battery control device, method, non-transitory computer-readable storage medium, and vehicle. A battery control device for controlling a battery includes: an acquisition unit configured to acquire the state of the battery; and an estimation unit configured to estimate the full charge capacity of the battery by selecting a first estimation method and a second estimation method based on the state acquired by the acquisition unit, the first estimation method being used to estimate the full charge capacity of the battery based on an accumulated current value obtained by accumulating the charging current of the battery obtained by performing a charging process, and the second estimation method being used to estimate the full charge capacity of the battery based on aging degradation data indicating the degradation state of the battery as it ages.

Description

Technical Field

[0001] The present disclosure relates to a battery control device for controlling a battery. Background Art

[0002] Secondary batteries that can be charged and discharged, such as lithium-ion batteries, gradually deteriorate because the full charge capacity of the battery decreases when charging and discharging are repeated. Since battery degradation affects the system using the battery, it is necessary to properly manage the full charge capacity of the battery.

[0003] As a method of properly managing the full charge capacity of a battery, for example, Japanese Unexamined Patent Application Publication No. 2017-096851 (JP 2017-096851A), Japanese Unexamined Patent Application Publication No. 2008-241358 (JP 2008-241358 A), Japanese Unexamined Patent Application Publication No. 2017-062175 (JP 2017-062175A), and Japanese Unexamined Patent Application Publication No. 2017-091852 (JP 2017-091852A) variously disclose techniques for estimating the full charge capacity of a battery by using a current integration method. Summary of the invention

[0004] In the process of estimating the full charge capacity of the battery by using the current integration method, in order to accurately estimate the full charge capacity, it is necessary to perform a charge and discharge process in which the difference in the charge state is large. Therefore, when the full charge capacity estimation process is frequently performed with priority given to accuracy, the battery may deteriorate faster.

[0005] The present disclosure provides a battery control device configured to accurately estimate the full charge capacity of a battery while suppressing acceleration of degradation of the battery.

[0006] A first aspect of the present invention relates to a battery control device, comprising an acquisition unit and an estimation unit. The acquisition unit is configured to acquire a state of a battery. The estimation unit is configured to estimate the full charge capacity of the battery by selecting a first estimation method and a second estimation method based on the state acquired by the acquisition unit, the first estimation method being used to estimate the full charge capacity of the battery based on an accumulated current value obtained by accumulating a charging current of the battery obtained by performing a charging process, and the second estimation method being used to estimate the full charge capacity of the battery based on aging degradation data indicating a degradation state of the battery as it ages.

[0007] The battery control device utilizing the above-mentioned scheme of the present disclosure uses a full charge capacity estimation method using a current integration method and a full charge capacity estimation method using aging degradation data respectively based at least on the temperature of the battery, thereby being able to accurately estimate the full charge capacity of the battery while suppressing accelerated battery degradation. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, wherein like reference numerals designate like elements, and wherein:

[0009] Figure 1 is a functional block diagram of a battery control device and its peripheral units according to a first embodiment;

[0010] Figure 2 is a diagram showing an example of battery aging degradation data;

[0011] Figure 3 is a process flow chart of control performed by the battery control device according to the first embodiment;

[0012] Figure 4 is a functional block diagram of a battery control device and its peripheral units according to a second embodiment;

[0013] Figure 5 is a process flow chart of control performed by the battery control device according to the second embodiment;

[0014] Figure 6 is a functional block diagram of a battery control device and its peripheral units according to a third embodiment;

[0015] Figure 7 is a process flow chart of control performed by the battery control device according to the third embodiment;

[0016] Figure 8 is a functional block diagram of a battery control device and its peripheral units according to a fourth embodiment;

[0017] Fig. 9 is a process flow chart of control performed by the battery control device according to the fourth embodiment; and

[0018] Fig.10 is a modified example of the processing flowchart of control executed by the battery control device according to the fourth embodiment. DETAILED DESCRIPTION

[0019] The battery control device of the above-mentioned scheme of the present disclosure performs estimation of the full charge capacity of the battery by selectively using a first estimation method based on the accumulated charging current value obtained by making the battery a high voltage and a second estimation method based on the aging degradation data of the battery based on the state of the battery. Therefore, the full charge capacity of the battery can be appropriately estimated while suppressing the acceleration of the degradation of the battery.

[0020] The battery control device of the above solution of the present disclosure can be installed in a vehicle that adopts a redundant power supply system and can switch between manual driving and automatic driving. Taking the case of being installed in a vehicle as an example, the embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[0021] First embodiment

[0022] Configuration

[0023] Figure 1 is a functional block diagram of the battery control device 10 and its peripheral units according to the first embodiment. Figure 1 The functional blocks shown in FIG. 1 include a battery control device 10, a power supply control ECU 50, and a battery 60. The battery control device 10 includes an acquisition unit 11, a clock unit 12, a storage unit 13, and an estimation unit 14.

[0024] The battery 60 is a secondary battery such as a lead storage battery or a lithium ion battery, which is configured to be able to charge and discharge. The battery 60 can supply the power stored in itself to a device (not shown) such as an electronic device or an electronic component called an electronic control unit (ECU). In the case of being installed on a vehicle that can switch between manual driving and automatic driving, the battery 60 can be used as a secondary battery as a backup for the main battery during automatic driving.

[0025] The power supply control ECU 50 is an electronic device that controls the entire power supply system including the battery 60. The power supply control ECU 50 detects voltage, current, and temperature as information about the battery 60. The power supply control ECU 50 may include a part or all of an ECU that monitors the voltage, current, and temperature of the battery 60 by using, for example, a voltage sensor, a current sensor, and a temperature sensor. The information (voltage, current, temperature) about the detected battery 60 is output to the battery control device 10.

[0026] In addition, the power supply control ECU 50 also performs charging control of the battery 60 based on the charging instruction output from the battery control device 10. The power supply control ECU 50 may include a DCDC converter capable of controlling the current and voltage of the battery 60 and a part or all of the ECU capable of controlling the DCDC converter. The charging control is performed until the state of charge (SOC) of the battery 60 reaches a predetermined high charge state.

[0027] The battery control device 10 performs control for estimating the full charge capacity of the battery 60. The battery control device 10 is generally configured as an ECU including a processor, a memory, an input-output interface, etc., and the processor reads and executes a program stored in the memory, thereby realizing the functions of each of the acquisition unit 11, the clock unit 12, the storage unit 13, and the estimation unit 14 to be described later.

[0028] The acquisition unit 11 acquires information (voltage, current, temperature) about the battery 60 from the power supply control ECU 50 .

[0029] The clock unit 12 measures a “timeout time” which is a time for judging the end of the charging process performed on the battery 60. In addition, the clock unit 12 measures a “time period of use of the battery 60” which is a time period indicating the number of days and time that have passed since the battery 60 was mounted on the vehicle.

[0030] The storage unit 13 stores "aging degradation data", which is data indicating the degradation state of the battery 60 as it ages. The aging degradation data is the capacity maintenance rate of the battery 60 in relation to the time that has passed after the start of use (or after being mounted on a vehicle), and is, as an example, data indicating the ratio or difference of the full charge capacity after degradation to the full charge capacity when the battery is new in terms of the number of years that have passed or the number of days that have passed. Figure 2 An example of aging degradation data of the battery 60 is shown. The storage unit 13 also stores the current full charge capacity of the battery 60. Whenever the full charge capacity of the battery 60 is estimated by the estimation unit 14 to be described later, the full charge capacity stored in the storage unit 13 is updated to the newly estimated full charge capacity.

[0031] The estimation unit 14 appropriately performs a process of estimating the full charge capacity of the battery 60 based on the state of the battery 60. The state of the battery 60 includes information (voltage, current, temperature) about the battery 60 acquired by the acquisition unit 11, the usage period of the battery 60 measured by the clock unit 12, and the aging degradation data of the battery 60 stored in the storage unit 13. When estimating the full charge capacity, any one of the following first estimation method and second estimation method is selectively used.

[0032] The first estimation method is a method of estimating the full charge capacity of the battery 60 based on the accumulated current value obtained from the battery 60. The estimation according to the first estimation method is performed by performing a charging process for charging the battery 60 from a first voltage to a second voltage, and by deriving a maximum state of charge that can be charged from the accumulated current value, the accumulated current value being obtained by accumulating the charging current of the battery 60 detected in the charging process. A known current accumulation method can be used for this first estimation method. The first voltage is the current voltage of the battery 60, and the second voltage is a voltage corresponding to the state of charge of the battery 60 defined in advance as the end of the charging process.

[0033] The second estimation method is a method of estimating the full charge capacity of the battery 60 based on the aging degradation of the battery 60. The estimation of the second estimation method is performed by correcting the full charge capacity of the battery 60 estimated last and stored in the storage unit 13 using the aging degradation data of the battery 60 stored in the storage unit 13 and the correction value derived from the usage period of the battery 60 measured by the clock unit 12. For example, when the full charge capacity of the battery 60 estimated last (stored in the storage unit 13) is "90%", and the correction value derived from the aging degradation data at the current time when the usage period is two years is "-5%", "85%" (=90%-5%) is estimated as the new full charge capacity of the battery 60 (stored in the storage unit 13).

[0034] In the first embodiment, how to estimate the full charge capacity of the battery 60 using the first estimation method and the second estimation method, respectively, will be described below.

[0035] control

[0036] Next, we will refer to Figure 3 Control performed by the battery control device 10 according to the first embodiment is described. Figure 3 1 is a flowchart showing a processing procedure of a battery estimation control for estimating the full charge capacity of the battery 60 executed by the battery control device 10 .

[0037] When the vehicle's power system is turned on (IG-ON, READY-ON, etc.), Figure 3 The battery estimation control shown in is started and is repeatedly executed until the power supply system is turned off (IG-OFF, READY-OFF, etc.).

[0038] Step S101: The estimation unit 14 of the battery control device 10 determines whether the temperature of the battery 60 acquired by the acquisition unit 11 is equal to or higher than the first temperature. This determination is made to determine whether the state of the battery 60 is in a high temperature state where degradation tends to occur. Therefore, based on the capacity and size of the battery 60 and the life span required of the battery 60, the first temperature is set as the optimal temperature for determining degradation of the battery 60.

[0039] When the temperature of the battery 60 is equal to or higher than the first temperature (S101, Yes), the estimation unit 14 determines that the battery 60 is in a state where degradation is more likely to occur, and the process proceeds to step S102. On the other hand, when the temperature of the battery 60 is lower than the first temperature (S101, No), the estimation unit 14 determines that the battery 60 is in a state where degradation is less likely to occur, and the process proceeds to step S108.

[0040] Step S102: The estimation unit 14 of the battery control device 10 instructs the clock unit 12 to measure the timeout time. Based on the instruction, the clock unit 12 clears the timeout time and starts counting from zero. The timeout time is used to determine the end of the charging process in step S104 to be described later. When the timeout time is measured, the process proceeds to step S103.

[0041] Step S103: The estimation unit 14 of the battery control device 10 instructs the power supply control ECU 50 to start the charging process of the battery 60. Then, together with the instruction of the charging process, the estimation unit 14 starts to integrate the charging current of the battery 60 acquired by the acquisition unit 11. When the charging process and the current integration are started, the process proceeds to step S104.

[0042] Step S104: The clock unit 12 of the battery control device 10 determines whether the timeout time being counted is shorter than the first time. Because the error (current sensor error, etc.) included in the accumulated current value increases when the charging process takes a long time, this determination is made to determine whether the charging process can continue as it is. Therefore, based on the accuracy required for the accumulated current value, the first time is set to the optimal time within the allowable error range.

[0043] When the timeout time is shorter than the first time (S104, Yes), the process proceeds to step S105, and when the timeout time is equal to or longer than the first time (S104, No), the process proceeds to step S107.

[0044] Step S105: The estimation unit 14 of the battery control device 10 determines whether the battery 60 is in a state where the charging process can be ended. For example, the determination can be made by determining whether the battery control device 10 has acquired a voltage corresponding to the charging state of the battery 60 that is pre-defined as the end of the charging process. The voltage corresponding to the charging state is an open circuit voltage (OCV) that can be derived from the SOC-OCV characteristic curve of the battery 60. The open circuit voltage can be calculated from the closed circuit voltage (CCV) of the battery 60 acquired by the acquisition unit 11.

[0045] When the charging process of the battery 60 is completed (S105, Yes), the process proceeds to step S106, and when the charging process of the battery 60 is not completed (S105, No), the process proceeds to step S104.

[0046] Step S106: The estimation unit 14 of the battery control device 10 estimates the full charge capacity of the battery 60 based on the accumulated current value obtained by the charging process (estimation using the first estimation method). The estimated full charge capacity is stored in the storage unit 13, and the full charge capacity of the battery 60 is updated. When the full charge capacity of the battery 60 is updated, the process proceeds to step S107.

[0047] Step S107: The estimation unit 14 of the battery control device 10 instructs the power supply control ECU 50 to end the charging process of the battery 60. When the charging process ends, the process proceeds to step S101.

[0048] Step S108: The estimation unit 14 of the battery control device 10 estimates the full charge capacity of the battery 60 based on the aging degradation data showing the degradation state of the battery 60 with aging (estimation using the second estimation method). The estimated full charge capacity is stored in the storage unit 13, and the full charge capacity of the battery 60 is updated. When the full charge capacity of the battery 60 is updated, the process proceeds to step S101.

[0049] According to the first embodiment described above, when the battery 60 is in a high temperature state (first temperature or higher) where degradation is more likely to occur, the full charge capacity is estimated with high accuracy by using the first estimation method (steps S103 to S107) for charging the battery 60 to a high voltage (high charge state). On the other hand, when the battery 60 is in a low temperature state (lower than the first temperature) where degradation is less likely to occur, the full charge capacity is simply estimated by using the second estimation method (step S108) for correcting the battery based on aging degradation data. Through this control, the number of times the battery 60 becomes a high voltage (high charge state) can be reduced, so that the full charge capacity of the battery 60 can be estimated while suppressing the acceleration of degradation of the battery 60.

[0050] Second embodiment

[0051] Configuration

[0052] Figure 4 is a functional block diagram of a battery control device 20 and its peripheral units according to the second embodiment. Figure 4 The functional blocks shown in FIG. 1 include a battery control device 20, a power supply control ECU 50, and a battery 60. The battery control device 20 includes an acquisition unit 11, a clock unit 22, a storage unit 13, and an estimation unit 24.

[0053] The battery control device 20 according to the second embodiment is different from the battery control device 10 according to the first embodiment in the configuration of the battery control device 20. Hereinafter, the battery control device 20 will be described with respect to the different configuration. The same components of the battery control device 20 as those of the battery control device 10 are denoted by the same reference numerals, and the description thereof will be partially omitted.

[0054] The battery control device 20 performs control for estimating the full charge capacity of the battery 60. The battery control device 20 is generally configured as an ECU including a processor, a memory, an input-output interface, etc., and the processor reads and executes a program stored in the memory, thereby realizing the functions of each of the acquisition unit 11, the clock unit 22, the storage unit 13, and the estimation unit 24 to be described later.

[0055] The acquisition unit 11 acquires information (voltage, current, temperature) about the battery 60 from the power supply control ECU 50 .

[0056] The clock unit 22 measures the "timeout time", which is the time for judging the end of the charging process performed on the battery 60. In addition, the clock unit 22 measures the "use period of the battery 60", which is a period of time indicating the number of days and time from when the battery 60 was installed on the vehicle to the present. In addition, the clock unit 22 measures the "unlearning period of the battery 60", which is the time period (number of days and hours) that has passed since the last time the full charge capacity of the battery 60 was estimated by the estimation unit 24 to be described later, that is, the time period during which the full charge capacity is not continuously estimated. It should be noted that, as in the estimation of the full charge capacity of the battery 60, the unlearning period is cleared and measurement is restarted immediately after the battery 60 is installed on the vehicle or immediately after the battery 60 is replaced.

[0057] The storage unit 13 separately stores the aging degradation data of the battery 60 and the current full charge capacity of the battery 60. Every time the estimation unit 24 described later estimates the full charge capacity of the battery 60, the full charge capacity is updated.

[0058] The estimation unit 24 appropriately performs a process of estimating the full charge capacity of the battery 60 based on the state of the battery 60. The state of the battery 60 includes information (voltage, current, temperature) about the battery 60 acquired by the acquisition unit 11, the use time period and the non-learning time period of the battery 60 measured by the clock unit 22, and the aging degradation data of the battery 60 stored in the storage unit 13. When estimating the full charge capacity, any one of the above-mentioned first estimation method and the second estimation method can be selectively used.

[0059] In the second embodiment, how to estimate the full charge capacity of the battery 60 using the first estimation method and the second estimation method, respectively, will be described below.

[0060] control

[0061] Next, we will refer to Figure 5 Control performed by the battery control device 20 according to the second embodiment is described. Figure 5 1 is a flowchart showing a processing procedure of a battery estimation control for estimating the full charge capacity of the battery 60 executed by the battery control device 20 .

[0062] Figure 5 The flowchart shown is Figure 3 The flowchart of the first embodiment shown in FIG. 1 adds the processing of steps S201, S202 and S203. It should be noted that since Figure 5 Steps other than steps S201, S202 and S203 in Figure 3 The processing is the same as described in , and part of the description will be omitted.

[0063] When the power supply system of the vehicle is turned on and the battery estimation control starts, the process of step S201 is first performed.

[0064] Step S201: The estimation unit 24 of the battery control device 20 determines whether the unlearned time period measured by the clock unit 22 is equal to or longer than the first time period. This determination is made in order not to estimate the full charge capacity of the battery 60 more than necessary. Therefore, the first time period is set as the optimal time period based on the frequency, the minimum number of times, etc. of estimating the full charge capacity predetermined for the quality control of the battery 60. For example, assuming that the full charge capacity of the battery 60 is estimated at least once every two months, the first time period may be set to two months.

[0065] When the unlearning time period is equal to or longer than the first time period (S201, Yes), the estimation unit 24 determines that it is time to estimate the full charge capacity of the battery 60, and the process proceeds to step S101. On the other hand, when the unlearning time period is less than the first time period (S201, No), the estimation unit 24 determines that it is not time to estimate the full charge capacity of the battery 60, and the process proceeds to step S201.

[0066] In step S106 , the full charge capacity of the battery 60 estimated by using the first estimation method is stored in the storage unit 13 , and the full charge capacity of the battery 60 is updated, and the process proceeds to step S202 .

[0067] Step S202: The clock unit 22 of the battery control device 20 performs “resetting of the unlearning time period” which clears the unlearning time period of the battery 60 and restarts the measurement. When the unlearning time period is reset, the process proceeds to step S107.

[0068] In step S108 , the full charge capacity of the battery 60 estimated by using the second estimation method is stored in the storage unit 13 , and the full charge capacity of the battery 60 is updated, and the process proceeds to step S203 .

[0069] Step S203: The clock unit 22 of the battery control device 20 performs “resetting of the unlearning time period” which clears the unlearning time period of the battery 60 and restarts the measurement. When the unlearning time period is reset, the process proceeds to step S101.

[0070] According to the second embodiment described above, the full charge capacity of the battery 60 is estimated only when the estimation unit 24 determines that the full charge capacity of the battery 60 needs to be estimated (first period or longer). As a result, frequent full charge capacity of the battery 60 can be suppressed.

[0071] Third embodiment

[0072] Configuration

[0073] Figure 6 is a functional block diagram of a battery control device 30 and its peripheral units according to the third embodiment. Figure 6 The functional blocks shown in FIG. 5 include a battery control device 30, a power supply control ECU 50, and a battery 60. The battery control device 30 includes an acquisition unit 11, a clock unit 32, a storage unit 13, and an estimation unit 34.

[0074] The battery control device 30 according to the third embodiment is different from the battery control device 10 according to the first embodiment in the configuration of the battery control device 30. Hereinafter, the battery control device 30 will be described with respect to the different configuration. The same components of the battery control device 30 as those of the battery control devices 10 and 20 are denoted by the same reference numerals, and the description thereof will be partially omitted.

[0075] The battery control device 30 performs control for estimating the full charge capacity of the battery 60. The battery control device 30 is generally configured as an ECU including a processor, a memory, an input-output interface, etc., and the processor reads and executes a program stored in the memory, thereby realizing the functions of each of the acquisition unit 11, the clock unit 32, the storage unit 13, and the estimation unit 34 to be described later.

[0076] The acquisition unit 11 acquires information (voltage, current, temperature) about the battery 60 from the power supply control ECU 50 .

[0077] The clock unit 32 measures the "timeout time", which is the time for judging the end of the charging process performed on the battery 60. In addition, the clock unit 32 measures the "use period of the battery 60", which is the number of days and time that have passed since the battery 60 was installed on the vehicle. In addition, the clock unit 32 measures the "unlearning period of the battery 60", which is the time period (days and hours) that has passed since the last time the estimation unit 34 described later estimated the full charge capacity of the battery 60, that is, the time period during which the full charge capacity is not continuously estimated. It should be noted that, as in the case of estimating the full charge capacity of the battery 60, immediately after the battery 60 is installed on the vehicle or immediately after the battery 60 is replaced, the unlearning period is cleared and the measurement is restarted.

[0078] The storage unit 13 separately stores the aging degradation data of the battery 60 and the current full charge capacity of the battery 60. Every time the estimation unit 34, which will be described later, estimates the full charge capacity of the battery 60, the full charge capacity is updated.

[0079] The estimation unit 34 appropriately performs a process of estimating the full charge capacity of the battery 60 based on the state of the battery 60. The state of the battery 60 includes information (voltage, current, temperature) about the battery 60 acquired by the acquisition unit 11, the use time period and the non-learning time period of the battery 60 measured by the clock unit 32, and the aging degradation data of the battery 60 stored in the storage unit 13. When estimating the full charge capacity, any one of the first estimation method and the second estimation method described above can be selectively used.

[0080] In the third embodiment, how to estimate the full charge capacity of the battery 60 using the first estimation method and the second estimation method, respectively, will be described below.

[0081] control

[0082] Next, we will refer to Figure 7 Control performed by the battery control device 30 according to the third embodiment is described. Figure 7 1 is a flowchart showing a processing procedure of a battery estimation control for estimating the full charge capacity of the battery 60 executed by the battery control device 30 .

[0083] Figure 7 The flowchart shown is Figure 3 The flowchart of the first embodiment shown in FIG. 1 adds the processing of steps S301, S302, S303, and S304. It should be noted that since Figure 7 Steps other than steps S301, S302, S303 and S304 in Figure 3 The processing described in is the same as that described in , so part of the description will be omitted.

[0084] In step S101, when the temperature of the battery 60 acquired by the acquisition unit 11 is equal to or higher than the first temperature (S101, Yes), the processing proceeds to step S301, and when the temperature of the battery 60 is lower than the first temperature (S101, No), the processing proceeds to step S302.

[0085] Step S301: The estimation unit 34 of the battery control device 30 determines whether the unlearned time period measured by the clock unit 32 is equal to or longer than the first time period. This determination is performed in order to limit the number of times the estimation using the first estimation method of applying a load to the battery 60 is performed on the battery 60 in a high temperature state where degradation is more likely to occur. Therefore, the first time period is set as the optimal time period based on the frequency of estimating the full charge capacity, the minimum number of times, etc. predetermined for the quality control of the battery 60.

[0086] For example, assuming that the full charge capacity of the battery 60 is estimated at least twice a year, when the time period when the temperature of the battery 60 is equal to or higher than the first temperature is six months including summer, and when there is a possibility that there is a failure of not completing the estimation due to timeout or the like every two times, the first time period can be set to two months. With this setting, the first estimation method can be used to perform the estimation three times in the six months when the temperature of the battery 60 is equal to or higher than the first temperature, and even if the estimation fails twice in three times, a successful estimation can be performed. In this example, since the first time period is shorter than two months, the number of estimations performed using the first estimation method increases, and thus the load applied to the battery 60 also increases. On the other hand, the longer the first time period is longer than two months, the more the load on the battery 60 can be reduced, but since the number of estimations performed using the first estimation method decreases, there is a possibility that the regulations cannot be met due to estimation failure. Therefore, considering the trade-off, it is desirable to set the first time period to the optimal time period based on the temperature environment (cold area or warm area) in which the battery 60 is used.

[0087] When the unlearning time period is equal to or longer than the first time period (S301, Yes), the estimation unit 34 determines that it is time to estimate the full charge capacity of the battery 60, and the process proceeds to step S102. On the other hand, when the unlearning time period is less than the first time period (S301, No), the estimation unit 34 determines that it is not time to estimate the full charge capacity of the battery 60, and the process proceeds to step S101.

[0088] Step S302: The estimation unit 34 of the battery control device 30 determines whether the unlearned time period measured by the clock unit 32 is equal to or longer than the second time period. This determination is made to limit the number of times the estimation using the second estimation method is performed on the battery 60 in a low temperature state where degradation is difficult to occur. As with the first time period, the second time period is set as the optimal time period based on the frequency and minimum number of estimated full charge capacity predetermined for quality control of the battery 60, the temperature environment (cold area or warm area) in which the battery 60 is used, and the like.

[0089] Since the estimation using the second estimation method is an estimation performed by not applying a load to the battery 60 and without failed correction, there is no need to perform more estimation than the first estimation method. Therefore, assuming that the full charge capacity of the battery 60 is estimated at least twice a year as in the above example, the second time period can be set so that the estimation using the second estimation method can be performed at least once within a six-month period including the winter season when the temperature of the battery 60 becomes lower than the first temperature. Specifically, the second time period can be set to three months so that the number of estimations by the second estimation method is two or less, which is less than the number of estimations by the first estimation method (which is three). In this way, the second time period can be set to be longer than the first time period.

[0090] When the unlearning time period is equal to or longer than the second time period (S302, Yes), the estimation unit 34 determines that it is time to estimate the full charge capacity of the battery 60, and the process proceeds to step S108. On the other hand, when the unlearning time period is less than the second time period (S302, No), the estimation unit 34 determines that it is not time to estimate the full charge capacity of the battery 60, and the process proceeds to step S101.

[0091] In step S106 , the full charge capacity of the battery 60 estimated by using the first estimation method is stored in the storage unit 13 , and the full charge capacity of the battery 60 is updated, and the process proceeds to step S303 .

[0092] Step S303: The clock unit 32 of the battery control device 30 performs "resetting of the unlearning time period", which clears the unlearning time period of the battery 60 and restarts the measurement. When the unlearning time period is reset, the process proceeds to step S107.

[0093] In step S108 , the full charge capacity of the battery 60 estimated by using the second estimation method is stored in the storage unit 13 , and the full charge capacity of the battery 60 is updated, and the process proceeds to step S304 .

[0094] Step S304: The clock unit 32 of the battery control device 30 performs “resetting of the unlearning time period” which clears the unlearning time period of the battery 60 and restarts the measurement. When the unlearning time period is reset, the process proceeds to step S101.

[0095] According to the third embodiment described above, even when the battery 60 is in a high temperature state (the first temperature or higher) where degradation is relatively easy to occur, the full charge capacity of the battery 60 is not estimated assuming that the unlearning time period is short (shorter than the first time period). Thus, the load applied to the battery 60 due to the estimation using the first estimation method can be suppressed. On the other hand, even when the battery 60 is in a low temperature state (lower than the first temperature) where degradation is relatively hard to occur, the full charge capacity of the battery 60 is not estimated assuming that the unlearning time period is short (shorter than the second time period). As a result, it is possible to suppress frequent estimation using the second estimation method during a time period in which the full charge capacity of the battery 60 hardly fluctuates.

[0096] Fourth embodiment

[0097] Configuration

[0098] Figure 8 4 is a functional block diagram of a battery control device 40 and its peripheral units according to the fourth embodiment. Figure 8The functional blocks shown in FIG. 4 include a battery control device 40, a power supply control ECU 50, and a battery 60. The battery control device 40 includes an acquisition unit 41, a clock unit 32, a storage unit 43, and an estimation unit 44.

[0099] The battery control device 40 according to the fourth embodiment is different from the battery control device 30 according to the third embodiment in the configuration of the battery control device 40. Hereinafter, the battery control device 40 will be described with respect to the different configuration. The same components of the battery control device 40 as those of the battery control devices 10 and 30 are denoted by the same reference numerals, and the description thereof will be partially omitted.

[0100] The battery control device 40 performs control for estimating the full charge capacity of the battery 60. The battery control device 40 is generally configured as an ECU including a processor, a memory, an input-output interface, etc., and the processor reads and executes a program stored in the memory, thereby realizing the functions of each of the acquisition unit 41, the clock unit 32, the storage unit 43, and the estimation unit 44 to be described later.

[0101] The acquisition unit 41 acquires information (voltage, current, temperature) about the battery 60 from the power supply control ECU 50. Furthermore, the acquisition unit 41 acquires vehicle information indicating whether the vehicle is being driven manually or automatically from an onboard device (not shown).

[0102] The clock unit 32 respectively measures the timeout time for judging the end of the charging process, the usage time period of the battery 60, and the unlearning time period of the battery 60. It should be noted that immediately after the battery 60 is mounted on the vehicle or immediately after the battery 60 is replaced, the unlearning time period is cleared and the measurement is restarted.

[0103] The storage unit 43 stores the aging degradation data of the battery 60 and the current full charge capacity of the battery 60, respectively. The full charge capacity is updated every time the estimation unit 44, which will be described later, estimates the full charge capacity of the battery 60. In addition, the storage unit 43 stores the “number of estimations”, which is the number of times the estimation unit 44 estimates the full charge capacity of the battery 60 between the time when the power system of the vehicle is turned on and the time when the power system of the vehicle is turned off (one trip).

[0104] The estimation unit 44 appropriately performs a process of estimating the full charge capacity of the battery 60 based on the state of the battery 60. The state of the battery 60 includes information (voltage, current, temperature) about the battery 60 and vehicle information acquired by the acquisition unit 41, a usage time period and a non-learning time period of the battery 60 measured by the clock unit 22, and aging degradation data and the number of estimations of the battery 60 stored in the storage unit 43. When estimating the full charge capacity, any one of the above-mentioned first estimation method and the second estimation method is selectively used.

[0105] In the fourth embodiment, how to estimate the full charge capacity of the battery 60 using the first estimation method and the second estimation method, respectively, will be described below.

[0106] control

[0107] Next, we will refer to Fig. 9 Control performed by the battery control device 40 according to the fourth embodiment is described. Fig. 9 1 is a flowchart showing a processing procedure of a battery estimation control for estimating the full charge capacity of the battery 60 executed by the battery control device 40 .

[0108] Fig. 9 The flowchart shown is Figure 7 The flowchart of the third embodiment shown in FIG. 1 adds the processing of step S401. It should be noted that since Fig. 9 All steps except step S401 in Figure 7 The processing described in is the same as that described in , and some descriptions will be omitted.

[0109] When the non-learning time period is equal to or longer than the first time period in step S301 ( S301 , Yes), the process proceeds to step S401 .

[0110] Step S401: The estimation unit 44 of the battery control device 40 determines whether a predetermined condition is satisfied. The predetermined condition is a condition that all of the following four items are satisfied.

[0111] (First item): The current state of charge of the battery 60 is less than or equal to the first state of charge.

[0112] This item is an item for ensuring the amount of fluctuation in the state of charge required to improve the estimation accuracy of the full charge capacity using the first estimation method. For example, when it is necessary to make the state of charge of the battery 60 fluctuate by 20% or more during the charging process in order to improve the estimation accuracy of the full charge capacity, assuming that the state of charge at the end of the charging process is pre-defined as 80%, the first state of charge is set to 60% or less. Therefore, when this item is established, the amount of fluctuation in the state of charge required to improve the estimation accuracy of the full charge capacity of the battery 60 can be ensured in the charging process of the first estimation method.

[0113] (Second item): The vehicle is in manual driving mode

[0114] This item is an item for suppressing large fluctuations in the voltage and current of the battery 60 that occur during the charging process performed in the first estimation method. Generally, when the vehicle is traveling in an automatically operated manner, the voltage and current of the battery 60 fluctuate greatly because the battery 60 uses more power for sensing various sensors, automatically operating the steering rack and brakes, etc. compared to manual driving. Such large fluctuations in the voltage and current of the battery 60 may affect the charging process. Therefore, when this item is established, the fluctuations in the voltage and current of the battery 60 during the charging process of the first estimation method can be suppressed, and the estimation accuracy of the full charge capacity of the battery 60 can be improved.

[0115] (Third Item): This process is the first estimation process in one trip.

[0116] This item is an item for suppressing the number of times the battery 60 becomes a high voltage (high charge state) by the charging process performed in the first estimation method. A "trip" representing a time period of so-called continuous operation from when the power system of the vehicle is turned on to when the power system is turned off does not usually last for a week. Therefore, it is sufficient to perform the estimation process of the full charge capacity of the battery 60 performed in one trip time period once. Therefore, when this item is established, the number of times the battery 60 becomes a high voltage (high charge state) in one trip is only once, and the deterioration of the battery 60 can be suppressed.

[0117] (Fourth item): The starting OCV of the battery 60 has been acquired.

[0118] Like the first item, this item is an item for ensuring the amount of fluctuation in the state of charge required to improve the estimation accuracy of the full charge capacity using the first estimation method. The starting OCV is an open circuit voltage corresponding to the current state of charge of the battery 60 that is less than or equal to the first state of charge. Since devices such as the ECU and electrical components are connected to the battery 60, it is necessary to perform processing such as calculation based on the stable voltage of the battery 60 to obtain the open circuit voltage. Therefore, when this item is established, the charging processing of the first estimation method can be performed on the battery 60 in a stable state.

[0119] When the condition that all items are satisfied (S401, Yes), the process proceeds to step S102, and when the condition is not satisfied (S401, No), the process proceeds to step S101.

[0120] According to the fourth embodiment described above, even when the battery 60 is in a high temperature state (above the first temperature) where degradation is more likely to occur, and the unlearning period is long (above the first period), unless a predetermined condition is further satisfied, the full charge capacity of the battery 60 is not estimated. Thus, the load imposed on the battery 60 due to the estimation using the first estimation method can be suppressed.

[0121] Variations

[0122] In the battery estimation control according to the fourth embodiment described above, when the estimation unit 44 determines that the conditions that all items are satisfied are not satisfied (S401, No), the full charge capacity of the battery 60 is not estimated (return to step S101). However, when the full charge capacity of the battery 60 is not estimated for a long period of time because the conditions are not satisfied, the difference between the estimated full charge capacity and the actual full charge capacity of the battery 60 becomes large, which is not preferable as management of the battery 60.

[0123] Therefore, in the battery estimation control of this modification, as Fig.10 As shown in the flowchart of , when the estimation unit 44 determines in step S401 that the condition that all items are satisfied is not satisfied (S401, No), further, in step S402, when the estimation unit 44 determines whether the unlearning time period measured by the clock unit 22 is equal to or longer than the third time period, when it is determined that the unlearning time period is equal to or longer than the third time period (S402, Yes), the process proceeds to step S102 to estimate the full charge capacity of the battery 60. When the third time period is set to be equal to or longer than the first time period determined in step S101 and within the longest time period in which the full charge capacity of the battery 60 does not need to be estimated, even if the long time period does not satisfy the condition, the estimation process of the full charge capacity of the battery 60 can be performed at intervals within the third time period.

[0124] Function and effect

[0125] In the battery control device according to each of the above-described embodiments, based on the state of the battery (including one or more of the battery information (voltage, current, and temperature) and vehicle information, the battery usage time period and the unlearned time period, and the battery aging degradation data and the estimated number of times), the full charge capacity of the battery is estimated by selectively using a first estimation method based on the accumulated charging current value obtained by making the battery a high voltage (high charge state) and a second estimation method based on the aging degradation data of the battery. Therefore, the full charge capacity of the battery can be appropriately estimated while suppressing the acceleration of the degradation of the battery.

[0126] In the battery control device, since the full charge capacity is estimated by using the first estimation method that uses current integration to charge the battery to a high voltage (high charge state) only when the battery is in a high temperature state where battery degradation is likely to occur, the number of times the battery becomes a high voltage (high charge state) can be reduced, thereby suppressing the acceleration of battery degradation. In addition, the influence of the battery in a high voltage (high charge state) state on the vehicle-mounted device can be suppressed, for example, by connecting the battery in a high voltage (high charge state) state after estimating the full charge capacity to the vehicle-mounted device (ECU or electrical component).

[0127] In addition, the present battery control device limits the number of times of processing for estimating the full charge capacity of the battery based on the unlearned time period of the battery or a predetermined condition. As a result, the load applied to the battery due to the estimation using the first estimation method can be suppressed, and the estimation using the second estimation method can be suppressed from being frequently performed during a time period in which the full charge capacity of the battery hardly fluctuates.

[0128] An embodiment of the present disclosure has been described above, but the present disclosure may be viewed as a vehicle equipped with a battery control device, a battery control method executed by the battery control device having a processor and a memory, a control program for executing the battery control method, a computer-readable non-temporary storage medium storing the control program, and a power supply system including the battery control device.

[0129] The battery control device of the above aspect of the present disclosure may be used in a vehicle equipped with a battery.

Claims

1. A battery control device for controlling a battery, the battery control device being configured to be installed on a vehicle capable of autonomous driving, the battery control device include: an acquisition unit configured to acquire a state of the battery; as well as an estimating unit configured to estimate the full charge capacity of the battery by selecting, based on the state of the battery, a first estimating method for estimating the full charge capacity of the battery based on an accumulated current value obtained by accumulating a charging current of the battery obtained by performing a charging process, and a second estimating method for estimating the full charge capacity of the battery based on aging degradation data indicating a degradation state of the battery as it ages; The battery control device also includes: a clock unit configured to measure an elapsed time period, the elapsed time period being a time period that has elapsed since the estimation unit last estimated the full charge capacity of the battery, wherein: The acquisition unit is configured to acquire a temperature of the battery as the state; and The estimation unit is configured to when the temperature of the battery is equal to or higher than a first temperature and the elapsed time period is equal to or longer than a first time period, and further, when conditions that a state of charge of the battery is less than a first state of charge, a condition that the vehicle is in a manual driving state, a condition that an estimation process is performed for the first time after a power source of the vehicle is turned on, and a condition that an open circuit voltage of the battery is equal to or lower than a first voltage are all satisfied, estimating the full charge capacity of the battery by the first estimation method, and The full charge capacity of the battery is estimated by the second estimation method when the temperature of the battery is lower than the first temperature and the elapsed time period is equal to or longer than a second time period longer than the first time period.

2. The battery control device according to claim 1, in: The estimation unit is configured to when the temperature of the battery is equal to or higher than a first temperature, estimating the full charge capacity of the battery by the first estimation method, and When the temperature of the battery is lower than the first temperature, the full charge capacity of the battery is estimated by the second estimation method.

3. The battery control device according to claim 1 or 2, in, The estimation unit is configured to estimate the full charge capacity of the battery by selecting the first estimation method and the second estimation method based on the state of the battery when the elapsed time period is equal to or longer than a first time period.

4. The battery control device according to claim 1, in: The first time period is configured to be set based on the number of days in a year when the temperature of the battery is equal to or higher than the first temperature; as well as The second time period is configured to be set based on the number of days in a year when the temperature of the battery is lower than the first temperature.

5. The battery control device according to claim 1, in, The estimation unit is configured to estimate the full charge capacity of the battery by the first estimation method when the temperature of the battery is equal to or higher than the first temperature and the elapsed time period is equal to or longer than the first time period, even if neither of the conditions is satisfied, but when the elapsed time period exceeds a third time period longer than the first time period. 6 . A vehicle equipped with the battery control device according to claim 1 .

7. A control method executed by a computer of a battery control device used in a vehicle equipped with a battery and capable of autonomous driving, the control method include: A step of obtaining a status of the battery; a first estimating step of estimating a full charge capacity of the battery based on an integrated current value obtained by integrating a charging current of the battery obtained by executing a charging process; a second estimating step of estimating the full charge capacity of the battery based on aging degradation data, the aging degradation data indicating a degradation state of the battery as it ages; as well as a step of estimating the full charge capacity of the battery by selecting one of the first estimating step and the second estimating step based on the state of the battery; The control method further comprises: a step of measuring an elapsed time period, the elapsed time period being a time period that has elapsed since the full charge capacity of the battery was last estimated; A step of obtaining a temperature of the battery as the state; a step of estimating the full charge capacity of the battery by the first estimating step when the temperature of the battery is equal to or higher than a first temperature and the elapsed time period is equal to or longer than a first time period, and further, when conditions that the state of charge of the battery is less than a first state of charge, the vehicle is in a manual driving state, the estimation process is performed for the first time after the power of the vehicle is turned on, and the open circuit voltage of the battery is equal to or lower than a first voltage are all satisfied; and A step of estimating the full charge capacity of the battery by the second estimating step when the temperature of the battery is lower than the first temperature and the elapsed time period is equal to or longer than a second time period longer than the first time period.

8. A non-transitory computer-readable storage medium storing a control program which, when executed by a computer of a battery control device used in a vehicle equipped with a battery and capable of autonomous driving, causes the computer to perform the following steps: A step of obtaining a status of the battery; a first estimating step of estimating a full charge capacity of the battery based on an integrated current value obtained by integrating a charging current of the battery obtained by executing a charging process; a second estimating step of estimating the full charge capacity of the battery based on aging degradation data, the aging degradation data indicating a degradation state of the battery as it ages; as well as a step of estimating the full charge capacity of the battery by selecting one of the first estimating step and the second estimating step based on the state of the battery; When the control program is executed by the computer, the computer further performs the following steps: a step of measuring an elapsed time period, the elapsed time period being a time period that has elapsed since the full charge capacity of the battery was last estimated; A step of obtaining a temperature of the battery as the state; a step of estimating the full charge capacity of the battery by the first estimating step when the temperature of the battery is equal to or higher than a first temperature and the elapsed time period is equal to or longer than a first time period, and further, when a condition that the state of charge of the battery is less than a first state of charge, a condition that the vehicle is in a manual driving state, a condition that an estimation process is performed for the first time after the power of the vehicle is turned on, and a condition that the open circuit voltage of the battery is equal to or lower than a first voltage are all satisfied; as well as A step of estimating the full charge capacity of the battery by the second estimating step when the temperature of the battery is lower than the first temperature and the elapsed time period is equal to or longer than a second time period longer than the first time period.

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