Methods, devices, equipment, and storage media for determining vehicle battery capacity

Abstract

This application provides a method, apparatus, device, and storage medium for determining the capacity of a vehicle battery. The method includes: acquiring a reference curve of a battery of a vehicle under test, the reference curve representing the change in battery state of charge corresponding to changes in battery voltage during charging at the time of factory testing; determining a first slope of a first linear portion of the reference curve; acquiring a charging curve of the vehicle under test from its most recent charge, the charging curve representing the change in battery capacity corresponding to changes in battery voltage during the most recent charge; determining a second slope of a second linear portion of the charging curve, the battery voltage value corresponding to the endpoint of the second linear portion being the same as the battery voltage value corresponding to the endpoint of the first linear portion; and determining the current capacity of the battery based on the first slope and the second slope. This method improves the accuracy of determining the capacity of an automotive battery.

Description

Technical Field

[0001] This application relates to the field of new energy vehicles, and in particular to a method, apparatus, device and storage medium for determining the capacity of a vehicle battery. Background Technology

[0002] The new energy vehicle industry is booming, and the number of vehicles on the road has increased significantly. However, the driving range of aging batteries has always been a major concern, and the usable capacity of the battery is a direct indicator related to driving range. Current methods for calculating battery capacity involve completely discharging the vehicle battery and then fully charging it, measuring the charging capacity as the battery capacity. However, this method is difficult to replicate using typical user habits. Therefore, there is an urgent need to develop a more convenient and accurate method for calculating battery capacity.

[0003] To better suit users' driving habits, existing technologies propose using a two-point reverse lookup method based on open circuit voltage (OCV) to calculate vehicle battery capacity. First, the SOC (State of Charge) - OCV curve, obtained during factory testing, is used as a baseline curve for the vehicle battery. Then, data from a specific charging session is analyzed, extracting the battery's resting voltage (OCV1) before charging and OCV2 after charging. Using the OCV two-point reverse lookup method, the corresponding SOC1 and SOC2 values ​​are obtained, with the difference representing the change in SOC. The cumulative current from this charging data yields the charging amount. The ratio of the charging amount to the change in SOC is the battery capacity. This method eliminates the need to completely deplete or fully charge the battery during calculation, better aligning with user driving habits.

[0004] However, to ensure the accuracy of the measurement data, the battery needs to be left to stand for more than two hours before measuring the static voltage before and after charging. But in real-world driving habits, users rarely meet this requirement, with the static time often being less than one minute. This leads to a large deviation in the State of Charge (SOC) value of the battery pack obtained through the OCV two-point reverse lookup method, further resulting in a large error in battery capacity. Summary of the Invention

[0005] This application provides a method, apparatus, device, and storage medium for determining the capacity of a vehicle battery, in order to solve the problem of large errors in battery capacity.

[0006] In a first aspect, this application provides a method for determining the capacity of a vehicle battery, comprising:

[0007] Obtain the baseline curve of the battery of the vehicle under test. The baseline curve represents the change in the state of charge of the battery corresponding to the change in battery voltage during the charging process during the factory test.

[0008] Determine the first slope of the first linear portion of the reference curve;

[0009] Obtain the charging curve of the most recent charge of the vehicle under test. The charging curve represents the change in battery capacity corresponding to the change in battery voltage during the most recent charge.

[0010] Determine the second slope of the second linear portion in the charging curve, wherein the battery voltage value corresponding to the endpoint of the second linear portion is the same as the battery voltage value corresponding to the endpoint of the first linear portion.

[0011] The current capacity of the battery is determined based on the first slope and the second slope.

[0012] Secondly, this application provides a device for determining the capacity of a vehicle battery, comprising:

[0013] The acquisition module is used to acquire the reference curve of the battery of the vehicle under test. The reference curve represents the change of battery state of charge corresponding to the change of battery voltage during charging during factory testing.

[0014] The acquisition module is also used to acquire the charging curve of the most recent charging of the vehicle under test, and the charging curve represents the change in battery capacity corresponding to the change in battery voltage during the most recent charging process.

[0015] The calculation module is used to determine the first slope of the first linear portion of the reference curve;

[0016] The calculation module is also used to determine the second slope of the second linear portion of the charging curve, wherein the battery voltage value corresponding to the endpoint of the second linear portion is the same as the battery voltage value corresponding to the endpoint of the first linear portion.

[0017] A determining module is used to determine the current capacity of the battery based on the first slope and the second slope.

[0018] Thirdly, this application provides a device for determining the capacity of a vehicle battery, comprising:

[0019] Processor, memory, communication interface;

[0020] The memory is used to store the executable instructions of the processor;

[0021] The processor is configured to execute the method for determining the vehicle battery capacity as described in the first aspect above.

[0022] Fourthly, this application provides a readable storage medium, comprising:

[0023] When the computer program is executed by the processor, it implements the method for determining the vehicle battery capacity as described in the first aspect above.

[0024] The method, apparatus, device, and storage medium for determining vehicle battery capacity provided in this application first acquire a reference curve from the factory test of the vehicle battery and a charging curve from the vehicle's most recent charge. Based on the characteristics of the reference curve and the charging curve, a first linear portion and a second linear portion with the same voltage value at their endpoints are extracted. A first slope and a second slope are then determined based on the first and second linear portions, respectively. Finally, the current battery capacity of the vehicle is determined based on the relationship between the first and second slopes. This method of determining vehicle battery capacity based on slopes avoids errors in the battery pack's state of charge value caused by insufficient battery resting time, achieving a more accurate determination of the vehicle's current battery capacity. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0026] Figure 1 This is a flowchart illustrating the method for determining the vehicle battery capacity provided in this embodiment;

[0027] Figure 2 This is a baseline curve of the battery of the vehicle under test;

[0028] Figure 3 Charging curve of the vehicle under test for the most recent charging;

[0029] Figure 4 A flowchart illustrating another method for determining vehicle battery capacity provided in this application embodiment;

[0030] Figure 5 A schematic diagram of the structure of the vehicle battery capacity determination device provided in the embodiments of this application;

[0031] Figure 6 A schematic diagram of the structure of the device for determining the vehicle battery capacity provided in this application embodiment.

[0032] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0033] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0034] Existing technology uses a two-point reverse lookup method based on open circuit voltage (OCV) to calculate the battery capacity of a vehicle. First, the SOC (State of Charge) - OCV curve, obtained during the battery's factory testing, is used as a baseline curve. Then, data from a specific charging session of the vehicle is analyzed, extracting the battery's resting voltage (OCV1) for a certain period before charging and the resting voltage (OCV2) for a certain period after charging. Using the OCV two-point reverse lookup method, the corresponding battery state of charge values ​​(SOC1 and SOC2) are obtained, and the difference between them represents the change in the battery's state of charge. The cumulative current from this charging data is used to obtain the charging amount during the charging process. The ratio of the charging amount to the change in the battery's state of charge is the battery capacity. However, before measuring the resting voltage before and after charging, the battery must be left to rest for at least two hours. However, in real life, users' driving habits are unlikely to meet this requirement, which will lead to a large deviation in the SOC value obtained by the OCV two-point reverse lookup method, and further lead to a large error in battery capacity.

[0035] The method, apparatus, device, and storage medium for determining vehicle battery capacity provided in this application first acquire a reference curve of the battery of the vehicle under test and the charging curve of the vehicle's most recent charge. Based on the characteristics of the reference curve and the charging curve, a first linear portion and a second linear portion with the same voltage value at their endpoints are extracted. A first slope and a second slope are then determined based on the first and second linear portions, respectively. Finally, the battery capacity of the vehicle under test is confirmed based on the relationship between the first and second slopes. The method of determining vehicle battery capacity based on slopes eliminates the problem of errors in battery pack state-of-charge value lookup caused by insufficient battery resting time, making the confirmation of vehicle battery capacity more accurate.

[0036] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0037] Figure 1 This is a flowchart illustrating the method for determining vehicle battery capacity provided in the first embodiment of this application. This embodiment can be implemented using a device with data acquisition and data processing functions, through hardware, software, or a combination of hardware and software.

[0038] like Figure 1 As shown, the method for determining the vehicle battery capacity provided in this embodiment may include the following steps:

[0039] Step S101: Obtain the baseline curve of the battery of the vehicle under test. The baseline curve represents the change in the state of charge of the battery corresponding to the change in battery voltage during the charging process during the factory test.

[0040] Specifically, vehicle batteries undergo factory testing before leaving the factory. This factory testing measures the changes in battery voltage and their corresponding changes in state of charge (SOC) during charging. The relationship between battery voltage and SOC measured during factory testing can be used as a baseline curve for the vehicle battery. Figure 2 This is a baseline curve of the battery of the vehicle under test. The horizontal axis represents the battery's state of charge (SOC), and the vertical axis represents the battery voltage (OCV).

[0041] Step S102: Determine the first slope of the first linear portion of the reference curve.

[0042] Specifically, the first linear portion of the reference curve of the battery under test can be obtained from the reference curve of the battery under test obtained in step S101. Then, the slope of the first linear portion is determined based on the first linear portion of the reference curve of the battery under test, where the slope of the first linear portion represents the battery voltage per unit of charge of the battery under test when it leaves the factory.

[0043] Step S103: Obtain the charging curve of the most recent charge of the vehicle under test. The charging curve represents the change in battery capacity corresponding to the change in battery voltage during the most recent charge.

[0044] Specifically, when determining the current battery capacity of the vehicle under test, the data that best reflects the current battery state of the vehicle under test can be used, such as the charging curve of the vehicle under test's most recent charge. The charging curve shows the change in battery capacity corresponding to the change in battery voltage during the most recent charge. Figure 3 This is a charging curve of the vehicle under test for its most recent charge. The horizontal axis represents battery capacity, and the vertical axis represents battery voltage.

[0045] Step S104: Determine the second slope of the second linear portion in the charging curve. The battery voltage value corresponding to the endpoint of the second linear portion is the same as the battery voltage value corresponding to the endpoint of the first linear portion.

[0046] Specifically, the second linear portion of the charging curve of the vehicle under test for the most recent charge can be obtained from the charging curve of the vehicle under test for the most recent charge obtained in step S103. The acquisition of the second linear portion is related to the first linear portion of the reference curve of the battery of the vehicle under test obtained in step S102, that is, the battery voltage value corresponding to the endpoint of the second linear portion is the same as the battery voltage value corresponding to the endpoint of the first linear portion.

[0047] Therefore, specifically, the battery voltage value corresponding to the endpoint of the second linear portion of the charging curve of the vehicle under test can be obtained from the battery voltage value corresponding to the endpoint of the first linear portion of the reference curve of the vehicle under test's battery. The second linear portion of the charging curve of the vehicle under test is then extracted based on the battery voltage value corresponding to the endpoint of the second linear portion of the charging curve of the vehicle under test's most recent charge. The slope of the second linear portion is then determined based on this extracted second linear portion. The slope of the second linear portion represents the battery voltage per unit battery capacity during the most recent charge of the vehicle under test.

[0048] Step S105: Determine the current capacity of the battery based on the first slope and the second slope.

[0049] Specifically, the first slope of the first linear portion of the reference curve can be extracted from step S102; the second slope of the second linear portion of the charging curve can be extracted from step S104; and the current capacity of the battery can be determined based on the first slope and the second slope.

[0050] The current capacity C of the battery of the vehicle under test can be calculated using various algorithms, such as the following formula (1):

[0051]

[0052] The ratio of the second slope to the first slope represents the ratio of battery capacity to battery state of charge (SOC) at the same terminal battery voltage value, i.e., the current capacity of the vehicle under test. Since the battery capacity is typically highest during factory testing, it gradually decreases during battery use. Therefore, this embodiment determines the vehicle's current battery capacity using the first linear portion of the factory test baseline curve and the second linear portion of the most recent charging curve. Because the voltage endpoints of the first and second linear portions are the same, the slope reflects the change in battery capacity under the same voltage change. This allows for the determination of the battery's current capacity and avoids errors in the SOC value caused by insufficient battery resting time, thus improving the accuracy of determining the vehicle's current battery capacity.

[0053] The method for determining vehicle battery capacity provided in this embodiment obtains a reference curve of the battery of the vehicle under test and the charging curve of the vehicle's most recent charge. Based on the characteristics of the reference curve and the charging curve, it extracts a first linear portion and a second linear portion where the voltage values ​​at the endpoints are the same. Then, it determines a first slope and a second slope based on the first and second linear portions, respectively. Finally, it confirms the battery capacity of the vehicle under test based on the relationship between the first slope and the second slope. This method of determining vehicle battery capacity based on slope eliminates the error in querying the battery pack's state of charge value due to insufficient battery resting time, making the confirmation of vehicle battery capacity more accurate.

[0054] Figure 4 This is a flowchart illustrating another method for determining vehicle battery capacity provided in the second embodiment of this application. Figure 1 Based on the illustrated embodiment, the process of determining the first linear portion, the second linear portion, the first slope, and the second slope is described in detail.

[0055] like Figure 4 As shown, another method for determining vehicle battery capacity provided in this embodiment may include the following steps:

[0056] Step S401: Obtain the baseline curve of the battery of the vehicle under test. The baseline curve represents the change in the state of charge of the battery corresponding to the change in battery voltage during the charging process during the factory test.

[0057] Specifically, the process of obtaining the baseline curve of the battery of the vehicle under test is the same as described in step S101.

[0058] Here, battery voltage OCV refers to the open circuit voltage (OCV) of the battery, which is the voltage of the battery in the open circuit state. Specifically, the voltage in the open circuit state refers to the voltage when the charging and discharging current is less than the threshold and the battery has been left to stand for a certain period of time under certain temperature and pressure conditions. Therefore, in this embodiment, during the experimental measurement of the SOC-OCV curve, the battery is left to stand for a certain period of time, for example, 2 hours, before each measurement of the open circuit voltage.

[0059] The State of Charge (SOC) of a battery refers to the ratio of the remaining capacity of a battery after a period of use or long-term storage to its capacity in a fully charged state, usually expressed as a percentage. Its value ranges from 0 to 1. When the SOC = 0, the battery is fully discharged; when the SOC = 1, the battery is fully charged. It should be noted that the capacity of vehicle batteries is allowed to fluctuate within a certain range at the time of manufacture, for example, between 90% and 110%. Therefore, during the experimental measurement of the SOC-OCV curve before the vehicle battery leaves the factory, due to the normalization property of the SOC value, a normalized SOC-OCV curve can be obtained for each vehicle battery, eliminating the influence of battery capacity fluctuations at the time of manufacture on the SOC-OCV curve.

[0060] The SOC-OCV curve measurement experiment can begin when the battery charge is 100%, i.e., the battery pack's state of charge (SOC) is 1. After the battery charge is depleted in increments of 5% or 10%, the open-circuit voltage (OCV) is measured sequentially. The measurement continues until the battery charge is completely depleted, i.e., the battery pack's SOC = 0. Note that the battery needs to be allowed to rest for a certain period before each measurement, for example, 2 hours. Finally, the corresponding values ​​of the battery open-circuit voltage (OCV) and the battery pack's SOC can be plotted as an SOC-OCV curve, as shown below. Figure 2 As shown.

[0061] Step S402: Determine the linear interval from the reference curve, and extract a portion of the curve from the linear interval as the first linear part of the reference curve.

[0062] First, the linear interval of the reference curve can be determined, and the voltage values ​​corresponding to the endpoints of the linear interval can be obtained to obtain the voltage value interval corresponding to the voltage values.

[0063] Specifically, the linear interval of the reference curve of the vehicle under test, i.e., the SOC-OCV curve measured when the battery of the vehicle under test leaves the factory, can be obtained. The voltage values ​​corresponding to the endpoints of the linear interval can be found using the SOC-OCV curve graph. These voltage values ​​at both ends of the linear interval of the SOC-OCV curve can be represented by open-circuit voltage V0 and open-circuit voltage V3, where open-circuit voltage V3 > open-circuit voltage V0. The interval formed by open-circuit voltage V0 and open-circuit voltage V3 is the voltage value interval corresponding to the voltage values, i.e., the open-circuit voltage interval of the linear region of the reference curve of the battery of the vehicle under test. Figure 2 As shown.

[0064] Secondly, two voltage values ​​of the intercept curves can be selected from the voltage range to obtain the voltage value range of the intercept curves corresponding to the voltage values ​​of the intercept curves.

[0065] Specifically, two open-circuit voltage values ​​can be randomly selected from the aforementioned voltage range, i.e., the open-circuit voltage range of the linear region of the reference curve of the battery under test, and used as the voltage values ​​for curve interception. For example, open-circuit voltages V1 and V2 can be selected from the range formed by open-circuit voltages V0 and V3, where open-circuit voltage V3 > open-circuit voltage V2 > open-circuit voltage V1 > open-circuit voltage V0. Open-circuit voltage V1 can be set as the voltage value V1 for curve interception, and open-circuit voltage V2 can be set as the voltage value V2 for curve interception. The range corresponding to open-circuit voltages V1 and V2 is the voltage value range of the curve interception corresponding to the voltage values ​​of the intercepted curve.

[0066] Finally, the reference curve corresponding to the voltage value range of the intercepted curve can be extracted as the first linear part of the reference curve.

[0067] Specifically, the range of voltage values ​​of the cut curve, that is, the reference curve of the vehicle battery under test corresponding to the voltage value V1 to the voltage value V2 of the cut curve, can be extracted. The obtained linear curve can be used as the linear cut curve of the reference curve of the vehicle battery under test, that is, the first linear part of the reference curve.

[0068] The description of the first linear part is the same as in step S102.

[0069] Step S403: Perform linear fitting on the first linear part of the reference curve to obtain the first slope.

[0070] First, a first-order linear equation can be fitted to the first linear portion of the reference curve.

[0071] Secondly, the coefficients of the first-order linear equation of the first linear part of the benchmark curve can be extracted as the first slope.

[0072] The description of the first slope is the same as in step S102.

[0073] Step S404: Obtain the charging curve of the most recent charge of the vehicle under test. The charging curve represents the change in battery capacity corresponding to the change in battery voltage during the most recent charge.

[0074] First, we can obtain charging process data from the big data platform of the vehicle under test and filter out outliers in the charging process data.

[0075] Traditional vehicles use microcontrollers for data processing and storage. In this embodiment, a vehicle big data platform can be used for data processing and storage. This big data platform stores a large amount of vehicle-related data, offering significantly larger data storage capacity compared to traditional microcontroller platforms, reaching petabytes (PB) levels (1 PB = 1024 TB = 2^50 bytes). The vehicle big data platform also boasts faster data processing speeds.

[0076] Specifically, charging-related data can be extracted from the big data platform of the aforementioned vehicle under test, and outliers in the charging-related data can be filtered out to improve the accuracy of battery power determination.

[0077] Secondly, the most recent charging curve of the vehicle under test can be extracted from the filtered charging process data.

[0078] Specifically, as described in step S103, when determining the current battery capacity of the vehicle under test, data that best reflects the current battery state can be used, such as the charging curve of the vehicle under test's most recent charge. Therefore, the most recent charging curve of the vehicle under test can be extracted from the charging process data filtered for outliers. The charging curve represents the change in battery capacity corresponding to the change in battery voltage during the most recent charge.

[0079] Among them, the most recent slow charging curve of the vehicle under test can be extracted from the charging process data of the big data platform of the vehicle under test. The slow charging curve represents the change in battery capacity corresponding to the change in battery voltage during the slow charging process.

[0080] Specifically, the charging process of a car battery can be divided into fast charging and slow charging. Compared to fast charging, slow charging is more stable, resulting in a more accurate slow charging curve. This embodiment can extract the most recent slow charging curve of the vehicle under test as the most recent charging curve to confirm the current battery capacity, achieving higher accuracy. Figure 3 As shown.

[0081] Step S405: Based on the battery voltage value corresponding to the endpoint of the first linear part, extract a portion of the curve from the charging curve as the second linear part of the charging curve.

[0082] First, the battery voltage value corresponding to the endpoint of the first linear part of the baseline curve can be extracted to obtain the range of battery voltage values, that is, the voltage value range of the curve is extracted.

[0083] Specifically, the voltage value range of the cut curve corresponding to the voltage value of the cut curve can be extracted from step S402, that is, the battery voltage value corresponding to the endpoint of the first linear part of the reference curve. As described in step S104, the battery voltage value corresponding to the endpoint of the second linear part is the same as the battery voltage value corresponding to the endpoint of the first linear part. Therefore, the battery voltage value corresponding to the endpoint of the second linear part of the charging curve can be obtained from the battery voltage value corresponding to the endpoint of the first linear part of the reference curve, that is, the voltage values ​​V1 and V2 of the cut curve. The voltage value range corresponding to the voltage values ​​V1 and V2 of the cut curve is the voltage value range of the cut curve.

[0084] Secondly, the charging curve corresponding to the voltage value range of the cut curve can be extracted as the second linear part of the charging curve.

[0085] Specifically, the range of voltage values ​​of the cut curve, that is, the most recent charging curve of the vehicle under test corresponding to the voltage value V1 to the voltage value V2 of the cut curve, can be extracted. The resulting linear curve can be used as the linear cut curve of the most recent charging curve of the vehicle under test, that is, the second linear part of the charging curve.

[0086] Step S406: Perform linear fitting on the second linear portion of the charging curve to obtain the second slope.

[0087] First, a first-order linear equation can be fitted to the second linear portion of the charging curve.

[0088] Secondly, the coefficients of the first-order linear equation of the second linear part of the charging curve can be extracted as the second slope.

[0089] The description of the first slope is the same as in step S104.

[0090] Step S407: Determine the current capacity of the battery based on the first slope and the second slope.

[0091] The steps for determining the current battery capacity are the same as in step S105.

[0092] The vehicle battery capacity calculation method provided in this embodiment selects the same voltage value range from the baseline curve of the vehicle battery under test and the charging curve of the vehicle's most recent charge to extract the linear portion. It then uses a first-order linear equation fitting method to obtain the slope of the extracted linear portion and uses the relationship between the slopes to calculate the current battery capacity of the vehicle under test. This method avoids the measurement and application of static voltage values, eliminating calculation errors caused by insufficient static time and improving the accuracy of vehicle battery capacity calculation. Furthermore, the entire calculation program runs on a big data platform, processing petabytes (PB) of data, overcoming the bottleneck of limited microcontroller capabilities, operating resources, and storage resources in traditional program execution environments.

[0093] Figure 5 This is a schematic diagram of the structure of the vehicle battery capacity determination device provided in the third embodiment of this application.

[0094] like Figure 5 As shown, the vehicle battery capacity determination device 50 provided in this embodiment may include: an acquisition module 51, a calculation module 52, and a determination module 53.

[0095] The acquisition module 51 is used to acquire the reference curve of the battery of the vehicle under test. The reference curve represents the change of battery state of charge corresponding to the change of battery voltage during the charging process during the factory test.

[0096] The acquisition module 51 is also used to acquire the charging curve of the most recent charging of the vehicle under test. The charging curve represents the change in battery capacity corresponding to the change in battery voltage during the most recent charging process.

[0097] Calculation module 52 is used to determine the first slope of the first linear portion of the reference curve;

[0098] The calculation module 52 is also used to determine the second slope of the second linear part in the charging curve, wherein the battery voltage value corresponding to the endpoint of the second linear part is the same as the battery voltage value corresponding to the endpoint of the first linear part.

[0099] The determination module 53 is used to determine the current capacity of the battery based on the first slope and the second slope.

[0100] The apparatus provided in this embodiment can be used to execute the above-described method embodiments. Figures 1 to 4 The technical solution is similar in principle and effect, and will not be described again in this embodiment.

[0101] Figure 6 This is a schematic diagram of the structure of the device for determining the vehicle battery capacity provided in the fourth embodiment of this application.

[0102] like Figure 6 As shown, the vehicle battery capacity determination device 60 provided in this embodiment may include: a processor 61, a memory 62, and a communication interface 63;

[0103] Memory 62 is used to store executable instructions of processor 61;

[0104] The processor 61 is configured to execute the above method embodiments by executing executable instructions. Figures 1 to 4 Methods for determining the battery capacity of any vehicle.

[0105] This application also provides a readable storage medium storing a computer program thereon, wherein the computer program, when executed by processor 61, implements the above-described method embodiments. Figures 1 to 4 Methods for determining the battery capacity of any vehicle.

[0106] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0107] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for determining the capacity of a vehicle battery, characterized in that, include: Obtain the baseline curve of the battery of the vehicle under test. The baseline curve represents the change of battery state of charge corresponding to the change of battery voltage OCV during the charging process during the factory test. Determine the first slope of the first linear portion of the reference curve; Obtain the charging curve of the most recent charge of the vehicle under test. The charging curve represents the change in battery capacity corresponding to the change in battery voltage during the most recent charge. The charging curve is a slow charging curve. Determine the second slope of the second linear portion in the charging curve, wherein the battery voltage value corresponding to the endpoint of the second linear portion is the same as the battery voltage value corresponding to the endpoint of the first linear portion, and the second slope represents the battery voltage per unit battery capacity of the battery of the vehicle under test during the most recent charging. The current capacity of the battery is determined based on the first slope and the second slope, wherein the current capacity of the battery is the ratio of the second slope to the first slope.

2. The method according to claim 1, characterized in that, Determining the first slope of the first linear portion of the reference curve includes: A linear interval is determined from the reference curve, and a portion of the curve is extracted from the linear interval as the first linear part of the reference curve; The first slope is obtained by linearly fitting the first linear portion of the reference curve.

3. The method according to claim 2, characterized in that, Determining the second slope of the second linear portion of the charging curve includes: Based on the battery voltage value corresponding to the endpoint of the first linear portion, a portion of the curve is extracted from the charging curve as the second linear portion of the charging curve; The second slope is obtained by linearly fitting the second linear portion of the charging curve.

4. The method according to claim 2, characterized in that, The step of determining a linear interval from the reference curve and extracting a portion of the curve from the linear interval as the first linear portion of the reference curve includes: Determine the linear interval of the reference curve, obtain the voltage values ​​corresponding to the endpoints of the linear interval, and obtain the voltage value interval corresponding to the voltage values; Two intercepted curves are selected from the voltage value range to obtain the voltage value range of the intercepted curves corresponding to the voltage values ​​of the intercepted curves; The reference curve corresponding to the voltage value range of the intercepted curve is extracted and used as the first linear part of the reference curve.

5. The method according to claim 4, characterized in that, The step of linearly fitting the first linear portion of the reference curve to obtain the first slope includes: Fit a first-order linear equation to the first linear portion of the reference curve; The coefficients of the first-order linear equation of the first linear portion of the reference curve are extracted and used as the first slope.

6. The method according to claim 4, characterized in that, The step of extracting a portion of the charging curve as the second linear portion of the charging curve based on the battery voltage value corresponding to the endpoint of the first linear portion includes: Extract the battery voltage value corresponding to the endpoint of the first linear part of the reference curve to obtain the range of the battery voltage value, that is, the voltage value range of the truncated curve; The charging curve corresponding to the voltage value range of the intercepted curve is extracted and used as the second linear part of the charging curve.

7. The method according to claim 6, characterized in that, The step of linearly fitting the second linear portion of the charging curve to obtain the second slope includes: Fit a first-order linear equation to the second linear portion of the charging curve; The coefficients of the first-order linear equation of the second linear portion of the charging curve are extracted and used as the second slope.

8. The method according to any one of claims 1-7, characterized in that, The process of obtaining the most recent charging curve of the vehicle under test includes: Obtain charging process data from the big data platform of the vehicle under test, and perform outlier filtering on the charging process data; Extract the most recent charging curve of the vehicle under test from the filtered charging process data.

9. The method according to claim 8, characterized in that, The step of extracting the most recent charging curve of the vehicle under test from the filtered charging process data includes: The most recent slow charging curve of the vehicle under test is extracted from the charging process data of the big data platform of the vehicle under test. The slow charging curve represents the change in battery capacity corresponding to the change in battery voltage during the slow charging process.

10. A device for determining the capacity of a vehicle battery, characterized in that, include: The acquisition module is used to acquire the reference curve of the battery of the vehicle under test. The reference curve represents the change of battery state of charge corresponding to the change of battery voltage OCV during the charging process during the factory test. The acquisition module is also used to acquire the charging curve of the most recent charge of the vehicle under test. The charging curve represents the change in battery capacity corresponding to the change in battery voltage during the most recent charge. The charging curve is a slow charging curve. The calculation module is used to determine the first slope of the first linear portion of the reference curve; The calculation module is also used to determine the second slope of the second linear part in the charging curve, wherein the battery voltage value corresponding to the endpoint of the second linear part is the same as the battery voltage value corresponding to the endpoint of the first linear part, and the second slope represents the battery voltage per unit battery capacity of the battery of the vehicle under test during the most recent charging. A determining module is configured to determine the current capacity of the battery based on the first slope and the second slope, wherein the current capacity of the battery is the ratio of the second slope to the first slope.

11. A device for determining the capacity of a vehicle battery, characterized in that, include: Processor, memory, communication interface; The memory is used to store the executable instructions of the processor; The processor is configured to execute the method for determining the vehicle battery capacity according to any one of claims 1 to 9 by executing the executable instructions.

12. A readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method for determining the vehicle battery capacity as described in any one of claims 1 to 9.

Images