A method for estimating SOC of an on-board backup battery

Abstract

The present application relates to battery state of charge estimation technical field, disclose a kind of estimation method of vehicle-mounted backup battery SOC, comprising: based on the inherent parameter of vehicle-mounted backup battery, establish the mapping relationship library of the electric parameter and SOC of vehicle-mounted backup battery under different characteristics;Obtain external crash signal and the real-time electric parameter of vehicle-mounted backup battery, determine the current working condition of vehicle-mounted backup battery;Based on current working condition, using corresponding SOC estimation strategy carries out SOC estimation;Wherein, SOC estimation strategy includes based on real-time electric parameter look-up mapping relationship library, or dynamically calculate real-time electric parameter.The present application can dynamically adjust estimation strategy according to different working conditions, while ensuring low power consumption hibernation, realize high-precision emergency estimation, and have temperature and aging self-adaptive correction ability, significantly improve the accuracy and reliability of SOC estimation.

Description

Technical Field

[0001] This invention relates to the field of battery state of charge estimation technology, and specifically to a method for estimating the SOC of an on-board backup battery. Background Technology

[0002] In automotive safety systems, the backup battery (typically a supercapacitor) of the collision unlocking module needs to quickly supply power to unlock the doors in the event of a collision and failure of the main battery. The accuracy of its State of Charge (SOC) estimation directly impacts safety redundancy. Existing backup battery SOC estimation methods primarily rely on general-purpose battery technology, which has the following drawbacks: 1. Poor adaptability to operating conditions: Backup batteries have the special characteristics of "long-term dormancy, instantaneous wake-up, and sudden high-current discharge". The ampere-hour integration method cannot quickly correct the accumulated error during the dormancy period, and the open-circuit voltage method requires a long period of rest, which is difficult to meet the instantaneous response requirements.

[0003] 2. Insufficient adaptability to environment and aging: In a wide temperature range (-40℃~105℃) working environment, temperature changes affect the open circuit voltage-state of charge (OCV-SOC) mapping relationship and internal resistance. Existing methods lack dynamic temperature compensation. The alternating cycle of long-term dormancy and instantaneous discharge leads to differences in aging rate. There is a lack of full life cycle adaptive correction, and the estimation accuracy decreases with the service life.

[0004] 3. Difficulty in balancing accuracy and power consumption: High-precision algorithms consume a lot of power, affecting the emergency availability of backup batteries; low-power simplified algorithms lack accuracy and may cause unlocking failure due to SOC misjudgment. Summary of the Invention

[0005] In view of this, the present invention provides a method for estimating the SOC of a vehicle backup battery to solve the problem of poor adaptability of backup battery SOC estimation methods under operating conditions in the prior art.

[0006] This invention provides a method for estimating the State of Charge (SOC) of an on-board backup battery, comprising: establishing a mapping relationship library between the electrical parameters of the on-board backup battery under different characteristics and the SOC based on the inherent parameters of the on-board backup battery; acquiring external collision signals and real-time electrical parameters of the on-board backup battery to determine the current operating condition of the on-board backup battery; and estimating the SOC based on the current operating condition using a corresponding SOC estimation strategy; wherein the SOC estimation strategy includes searching the mapping relationship library based on real-time electrical parameters or dynamically calculating real-time electrical parameters.

[0007] The present invention provides a method for estimating the State of Charge (SOC) of a vehicle backup battery. This method establishes a pre-built mapping library between the battery's electrical parameters and SOC under different characteristics, providing foundational data for subsequent estimations. By acquiring external collision signals and real-time electrical parameters, it accurately determines the current operating condition of the battery, achieving precise identification of the operating condition. Based on the identified current operating condition, a corresponding SOC estimation strategy is employed for SOC estimation. Specifically, under different operating conditions, SOC is obtained by either searching the mapping library or dynamically calculating real-time electrical parameters. This method, through differentiated estimation based on operating conditions, matches the SOC estimation strategy with the actual needs of the current operating condition. This ensures both the reliability of estimation under normal operating conditions and the accuracy of estimation under special operating conditions. Furthermore, by covering different characteristic parameters through the mapping library, it enhances the adaptability to environmental changes and battery aging processes. This effectively solves the technical problems of poor operating condition adaptability, insufficient environmental and aging adaptability, and difficulty in balancing accuracy and power consumption in existing technologies, significantly improving the accuracy and robustness of vehicle backup battery SOC estimation.

[0008] In one optional implementation, the inherent parameters include one or more of the following: rated capacity, sleep / wake-up threshold, collision signal threshold, temperature compensation coefficient, aging compensation coefficient, and ampere-hour integral coefficient; the electrical parameters include one or more of the following: terminal voltage, charging / discharging current, and battery temperature; the process of establishing a mapping relationship library between the electrical parameters and SOC of the vehicle backup battery under different characteristics includes: establishing a mapping relationship library between the electrical parameters and SOC of the vehicle backup battery under different temperatures and different aging degrees, and calibrating the mapping relationship library through offline testing.

[0009] In one optional implementation, the process of acquiring an external collision signal and real-time electrical parameters of the vehicle's backup battery, and determining the current operating condition of the backup battery, includes: identifying whether the backup battery is currently in a standby / dormant state, a wake-up detection state, or a collision emergency state based on the external collision signal and real-time electrical parameters; wherein, when the external collision signal is a first preset signal and the real-time electrical parameters meet a first preset condition, it is determined to be in a standby / dormant state; when the external collision signal is a first preset signal and the real-time electrical parameters meet a second preset condition, it is determined to be in a wake-up detection state; and when the external collision signal is a second preset signal or the real-time electrical parameters meet a third preset condition, it is determined to be in a collision emergency state.

[0010] In one optional implementation, when the system is determined to be in standby or hibernation mode, the process of estimating SOC based on a mapping database of real-time electrical parameters includes: obtaining a basic SOC value by searching the mapping database based on the collected electrical parameters; obtaining an estimated SOC value by correcting the basic SOC value using inherent parameters; using the current estimated SOC value as the basic SOC value for the next estimation, and returning to the step of "correcting the basic SOC value using inherent parameters" after a preset time interval.

[0011] In one optional implementation, the SOC estimate is calculated using the following formula during standby / sleep mode: SOC1=f(U0,T0)×K t0 Where U0 is the terminal voltage; T0 is the battery temperature; K t0 is the temperature compensation coefficient; SOC1 is the estimated SOC value; f(U0,T0) is the base SOC value.

[0012] In one optional implementation, when the wake-up detection condition is determined, the process of estimating SOC based on a mapping database using real-time electrical parameters includes: obtaining a preset initial SOC value; calculating a preliminary SOC estimate using the ampere-hour integration method based on the initial SOC value; obtaining a basic SOC value by searching the mapping database based on the collected real-time electrical parameters, and correcting the basic SOC value using inherent parameters to obtain a calibration value; weighting and fusing the preliminary SOC estimate and the calibration value to obtain a SOC estimate; using the current SOC estimate as the initial SOC value for the next estimation, and returning to the step of "calculating a preliminary SOC estimate using the ampere-hour integration method based on the initial SOC value" after a preset time interval.

[0013] In one optional implementation, under wake-up detection conditions, the SOC estimate is calculated using the following formula: SOC2'=SOC2×α+SOC_cal×β SOC_cal=f(U0,T0)×K t0 Where SOC2' is the estimated SOC value; SOC2 is the preliminary estimated SOC value; SOC_cal is the calibration value; U0 is the terminal voltage; T0 is the battery temperature; K t0 α is the temperature compensation coefficient; f(U0,T0) is the basic SOC value; α and β are weighting coefficients, and α+β=1.

[0014] In one optional implementation, when a collision emergency condition is determined, the process of dynamically calculating real-time electrical parameters to estimate the State of Charge (SOC) includes: increasing the frequency of electrical parameter acquisition; using a filtering algorithm to establish a state-space model based on the acquired real-time electrical parameters, dynamically estimating the SOC, and obtaining a dynamic estimate value; calculating the collision instantaneous current compensation coefficient based on the relationship between the real-time charging / discharging current and the rated discharge current; and using the aging compensation coefficient and the collision instantaneous current compensation coefficient to correct the dynamic estimate value and obtain the SOC estimate value.

[0015] The method for estimating the State of Charge (SOC) of a vehicle backup battery provided by this invention, when a collision emergency is identified, dynamically estimates the SOC by increasing the frequency of electrical parameter acquisition, using a filtering algorithm to establish a state-space model, and introducing a collision instantaneous current compensation coefficient calculated based on the relationship between real-time charging / discharging current and rated discharge current. Combined with an aging compensation coefficient, the dynamic estimated value is corrected. This method can effectively cope with the high current impact scenario at the moment of collision, achieving rapid response and high-precision estimation of SOC. It avoids misjudgment of battery capacity due to estimation lag or insufficient accuracy, ensuring that the backup battery has sufficient power supply capacity to unlock the vehicle door in an emergency, and significantly improving the real-time performance and reliability of SOC estimation under collision emergency conditions.

[0016] In one optional implementation, the method further includes: performing a reasonableness check on the obtained SOC estimate based on a preset range; if the SOC estimate is within the preset range, outputting the current SOC estimate; if the SOC estimate is outside the preset range, using the last valid SOC value as a temporary output, and returning to the step of "obtaining the external collision signal and the real-time electrical parameters of the vehicle backup battery, and determining the current operating condition of the vehicle backup battery".

[0017] In one optional implementation, the method further includes: recording the operating data of the vehicle backup battery according to a preset cycle, the operating data including at least the charging and discharging data, temperature data, number of cycles, and SOC estimate of the vehicle backup battery; updating the inherent parameters based on the records and optimizing the mapping relationship library; and triggering a fault warning signal when the number of cycles reaches the rated number of cycles or the error of the SOC estimate continues to exceed a preset threshold. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1This is a flowchart illustrating a method for estimating the State of Charge (SOC) of an onboard backup battery according to an embodiment of the present invention. Figure 2 This is a composition diagram of an on-board backup battery SOC estimation device according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0022] This embodiment provides a method for estimating the State of Charge (SOC) of an onboard backup battery, such as... Figure 1 As shown, it includes: Step S1: Based on the inherent parameters of the vehicle backup battery, establish a mapping relationship library between the electrical parameters of the vehicle backup battery under different characteristics and the SOC.

[0023] Optionally, inherent parameters include: rated capacity C n Hibernation / wake-up threshold V s Collision signal threshold P0, temperature compensation coefficient K t Aging compensation coefficient K a And the integral coefficient η in ampere-hours, etc.; electrical parameters include terminal voltage, charging and discharging current and battery temperature, etc.

[0024] The process of establishing a mapping relationship library between the electrical parameters and SOC of the vehicle backup battery under different characteristics includes: establishing a mapping relationship library between the electrical parameters and SOC of the vehicle backup battery under different temperatures and different aging degrees, and calibrating the mapping relationship library through offline tests.

[0025] Specifically, through offline testing and calibration, a mapping library of electrical parameters and State of Charge (SOC) of the vehicle's backup battery under different temperatures and aging stages is established. The temperature range covers a wide temperature spectrum typical of automotive driving environments (e.g., -40℃ to 105℃), and the aging stages encompass the entire battery lifecycle from its initial state to the end of its lifespan. During offline testing, charge-discharge tests are conducted on the battery under different temperature conditions, recording the mapping relationship between electrical parameters such as terminal voltage, charge / discharge current, and temperature at different aging stages and their corresponding SOC, forming a multi-dimensional mapping library. This mapping library is pre-stored in the control module for use in SOC estimation under different operating conditions, enabling rapid acquisition of the corresponding SOC value based on current electrical parameters and providing fundamental data support for operating condition-specific estimation strategies.

[0026] Step S2: Obtain the external collision signal and the real-time electrical parameters of the vehicle's backup battery to determine the current operating condition of the backup battery.

[0027] Specifically, based on external collision signals and real-time electrical parameters, the system identifies whether the vehicle's backup battery is currently in standby / dormant mode, wake-up detection mode, or collision emergency mode. The criteria for determining each mode are as follows: (1) When the external collision signal is the first preset signal and the real-time electrical parameters meet the first preset condition, it is determined to be in standby hibernation mode: for example, when the duty cycle of the external collision signal is equal to the duty cycle of the first preset PWM signal, it indicates that the vehicle is in normal operation and no collision has occurred; and when the real-time electrical parameters meet the first preset condition, it is determined to be in standby hibernation mode. Among them, the first preset condition specifically includes: the terminal voltage of the vehicle backup battery is greater than or equal to the hibernation wake-up threshold V. s This indicates that the main battery is supplying power normally; the zero charging / discharging current indicates that the battery is in a static state with no charging or discharging activity. At this time, the vehicle is in a long-term dormant phase during normal operation and the backup battery has not been activated. Only extremely low power consumption is needed to maintain basic status monitoring and reserve energy for possible subsequent collision emergency events.

[0028] (2) When the external collision signal is the first preset signal and the real-time electrical parameters meet the second preset condition, it is determined to be a wake-up detection condition: for example, when the duty cycle of the external collision signal is equal to the duty cycle of the first preset PWM signal (the first preset PWM signal duty cycle < P0), it indicates that the vehicle is in normal operation and no collision has occurred; and when the real-time electrical parameters meet the second preset condition, it is determined to be a wake-up detection condition. The second preset condition specifically includes: the terminal voltage of the vehicle backup battery is greater than or equal to the sleep wake-up threshold V. s This indicates that the main battery is supplying power normally; a non-zero charging / discharging current indicates that the battery is in an active state of charging or self-discharging. At this time, although the vehicle has not been involved in a collision, the backup battery is periodically awakened for status detection or charging maintenance, requiring both accurate estimation and power consumption control.

[0029] (3) When the external collision signal is the second preset signal or the real-time electrical parameters meet the third preset condition, it is determined to be a collision emergency condition: for example, when the duty cycle of the external collision signal is equal to the duty cycle of the second preset PWM signal (the second preset PWM signal duty cycle ≥ P0), it indicates that the vehicle has collided; or when the real-time electrical parameters meet the third preset condition, it is determined to be a collision emergency condition. Among them, the third preset condition specifically includes: the terminal voltage of the vehicle backup battery is less than the sleep wake-up threshold V. s This indicates that the main battery has failed due to a collision impact, breakage, or short circuit. In this case, if a vehicle collision occurs or the main battery has failed, the backup battery needs to be activated immediately to power the door unlocking mechanism. This places the highest demands on the real-time performance and accuracy of SOC estimation, requiring a rapid response to instantaneous high-current discharge scenarios to ensure reliable execution of the unlocking action.

[0030] Step S3: Based on the current operating conditions, use the corresponding SOC estimation strategy to estimate the SOC; wherein, the SOC estimation strategy includes searching the mapping relationship library based on real-time electrical parameters, or dynamically calculating real-time electrical parameters.

[0031] Specifically, when the system is determined to be in standby or hibernation mode, the SOC estimation strategy adopts a method based on real-time electrical parameters to look up the mapping relationship library. That is, based on the collected terminal voltage and temperature, the corresponding basic SOC value is quickly retrieved from the pre-calibrated mapping relationship library and corrected by combining the temperature compensation coefficient, so as to obtain the current SOC estimation value under extremely low power consumption.

[0032] When the wake-up detection condition is determined, the SOC estimation strategy integrates two methods: dynamic calculation based on real-time electrical parameters and mapping relationship library search. That is, the ampere-hour integration method is used to calculate the preliminary SOC estimate in real time based on the charging and discharging current, while the open-circuit voltage method is used periodically to search the mapping relationship library to obtain the calibration value. The two are weighted and integrated to balance estimation accuracy and real-time performance.

[0033] When a collision emergency is identified, the SOC estimation strategy adopts a dynamic calculation of real-time electrical parameters. This involves increasing the frequency of electrical parameter acquisition, using a filtering algorithm to establish a state-space model based on terminal voltage, charging and discharging current, and temperature for dynamic estimation, and combining aging compensation coefficient and collision instantaneous current compensation coefficient for correction to meet the high-precision estimation requirements under instantaneous high-current discharge scenarios.

[0034] The State of Charge (SOC) estimation method for vehicle backup batteries provided in this embodiment establishes a pre-built mapping library of electrical parameters and SOC of the vehicle backup battery under different characteristics, providing basic data support for subsequent estimation. By acquiring external collision signals and real-time electrical parameters, it accurately determines the current operating condition of the vehicle backup battery, achieving precise identification of the operating condition. Then, based on the identified current operating condition, it adopts the corresponding SOC estimation strategy to estimate the SOC. Specifically, under different operating conditions, it obtains the SOC by either looking up the mapping library or dynamically calculating real-time electrical parameters. This method, through differentiated estimation based on operating conditions, matches the SOC estimation strategy with the actual needs of the current operating condition, ensuring both the reliability of estimation under normal operating conditions and the accuracy of estimation under special operating conditions. At the same time, by covering different characteristic parameters through the mapping library, it enhances the adaptability to environmental changes and battery aging processes, effectively solving the technical problems of poor operating condition adaptability, insufficient environmental and aging adaptability, and difficulty in balancing accuracy and power consumption in existing technologies. This significantly improves the accuracy and robustness of vehicle backup battery SOC estimation.

[0035] In some optional implementations, when the system is determined to be in standby or hibernation mode, the process of estimating SOC based on a mapping database using real-time electrical parameters includes: (1) Based on the collected electrical parameters, search the mapping relationship library to obtain the basic SOC value.

[0036] Specifically, when the system is determined to be in standby / dormant mode, it first collects real-time electrical parameters of the vehicle battery, mainly including terminal voltage and temperature. Based on the collected terminal voltage and temperature, it searches a pre-calibrated mapping database, which covers the correspondence between electrical parameters and SOC under different temperatures and aging levels. By searching the mapping database, it obtains a baseline SOC value that matches the current terminal voltage and temperature. This baseline SOC value reflects the battery's state of charge benchmark under the current condition.

[0037] (2) After correcting the basic SOC value using the inherent parameters, the estimated SOC value is obtained.

[0038] Specifically, after obtaining the basic SOC value, the system further corrects it using a temperature compensation coefficient from its inherent parameters. Since the battery's OCV-SOC mapping relationship differs at different temperatures, a temperature compensation coefficient corresponding to the current temperature is introduced to multiply and correct the basic SOC value, resulting in the final estimated SOC value. This correction process effectively offsets the impact of temperature changes on the battery's electrical characteristics, ensuring the accuracy of the SOC estimation across the entire temperature range.

[0039] The formula for calculating the SOC estimate under standby / sleep conditions is as follows: SOC1=f(U0,T0)×Kt0 (1) Where U0 is the terminal voltage; T0 is the battery temperature; K t0 is the temperature compensation coefficient; SOC1 is the estimated SOC value under standby and hibernation conditions; f(U0,T0) is the base SOC value.

[0040] (3) Use the current SOC estimate as the base SOC value for the next estimate, and return to the step of “correcting the base SOC value using inherent parameters” after a preset time interval.

[0041] Specifically, after completing the current SOC estimation, the system stores the obtained SOC estimate as the base SOC value for the next SOC estimation under standby / sleep conditions, achieving iterative updates and continuity of the estimation results. Subsequently, the system controls the acquisition operation to enter a low-power sleep state to reduce its own power consumption. After a preset time interval, the system automatically wakes up and returns to the aforementioned step of "correcting the base SOC value using inherent parameters," restarting the acquisition and estimation process, thereby achieving periodic, low-power SOC monitoring in a long-term sleep state.

[0042] In some optional implementations, when the system is determined to be in a wake-up detection condition, the process of estimating SOC based on a mapping database using real-time electrical parameters includes: (1) Obtain the preset initial value of SOC.

[0043] Specifically, when the system is determined to be in wake-up detection mode, it first obtains the initial value of the SOC estimate. The initial value is obtained in different ways depending on the current situation: if the system is starting up for the first time or powering on for the first time, the preset original SOC value is used as the initial value; if it is not the first estimation, the SOC estimate value stored at the end of the previous estimation is read as the initial value for this estimation.

[0044] (2) Based on the initial value of SOC, the preliminary estimate of SOC is calculated using the ampere-hour integration method.

[0045] Specifically, after obtaining the initial SOC value, the system uses the ampere-hour integration method to estimate the SOC in real time. The ampere-hour integration method collects the charging and discharging current, integrates the current value over time, calculates the change in the battery's charging and discharging capacity, and adds or subtracts this change from the initial SOC value to obtain a preliminary estimate of the SOC.

[0046] The formula for calculating ampere-hours using the integral method is: SOC2=SOC 10 -∫(I×η)dt / C n (2) Where SOC2 is the preliminary estimate of SOC at the current moment; SOC 10The SOC value is the value at the previous or initial moment; I is the charging / discharging current, which is positive during discharging and negative during charging; η is the ampere-hour integral coefficient, used to compensate for differences in charging and discharging efficiency; C n Let be the rated capacity of the battery; ∫(I×η)dt represents the time integral of the product of current and efficiency, that is, the change in charge and discharge capacity from the previous moment to the current moment.

[0047] (3) Find the mapping relationship library based on the collected real-time electrical parameters to obtain the basic SOC value, and use the inherent parameters to correct the basic SOC value to obtain the calibration value.

[0048] Specifically, while performing the ampere-hour integration method for estimation, the system periodically collects the battery's terminal voltage and temperature, and after a brief period of rest, collects the open-circuit voltage. Based on the collected terminal voltage or open-circuit voltage and temperature, a pre-calibrated mapping library is consulted to obtain the baseline SOC value corresponding to the current electrical parameters. Subsequently, the baseline SOC value is corrected using the temperature compensation coefficient in the inherent parameters to obtain a calibration value. This calibration value can effectively compensate for the accuracy degradation caused by current sensor drift or accumulated errors in the ampere-hour integration method, providing a periodic correction basis for SOC estimation.

[0049] (4) The preliminary SOC estimate and the calibration value are weighted and fused to obtain the SOC estimate.

[0050] Specifically, after obtaining the preliminary SOC estimate and calibration value, the system performs a weighted fusion of the two. Specifically, based on the actual accuracy requirements, a weighting coefficient is preset, and the preliminary SOC estimate and calibration value are multiplied by their respective weighting coefficients and then added together to obtain the final SOC estimate.

[0051] Under wake-up detection conditions, the formula for calculating the SOC estimate is as follows: SOC2'=SOC2×α+SOC_cal×β(3) SOC_cal=f(U0,T0)×K t0 (4) Where SOC2' is the estimated SOC value under wake-up detection conditions; SOC2 is the preliminary estimated SOC value; SOC_cal is the calibration value; U0 is the terminal voltage; T0 is the battery temperature; K t0 α is the temperature compensation coefficient; f(U0,T0) is the basic SOC value; α and β are weighting coefficients, and α+β=1. The weighting coefficients are adjusted according to the actual accuracy requirements.

[0052] (5) Use the current SOC estimate as the initial SOC estimate for the next estimate, and return the step "Calculate the preliminary SOC estimate using the ampere-hour integration method based on the initial SOC value" after a preset time interval.

[0053] Specifically, after completing this SOC estimation, the system stores the obtained SOC estimate as the initial value for the next SOC estimation under wake-up detection conditions, ensuring the continuity and accuracy of the ampere-hour integration calculation. Subsequently, the system enters a preset time interval waiting state, during which it can enter a low-power mode or remain in standby mode as needed. After the preset time interval, the system automatically returns to the aforementioned step of "calculating the preliminary SOC estimate using the ampere-hour integration method based on the initial SOC value," restarting the SOC estimation process, thereby achieving periodic and highly reliable SOC monitoring and calibration under wake-up detection conditions.

[0054] In some optional implementations, when a collision emergency is identified, the process of dynamically calculating real-time electrical parameters to estimate the State of Charge (SOC) includes: (1) Increase the frequency of electrical parameter acquisition.

[0055] Specifically, when a collision emergency is identified, the system immediately triggers an emergency estimation mode, increasing the frequency of electrical parameter acquisition to several times that of normal operation, such as above 100Hz. High-frequency acquisition captures rapid changes in battery terminal voltage, charging / discharging current, and temperature at the moment of impact, providing high-time-resolution real-time data for subsequent dynamic estimation. This ensures that SOC estimation can respond promptly to sudden changes in battery capacity during high-current discharge scenarios, avoiding estimation lag caused by excessively long sampling intervals.

[0056] (2) A filtering algorithm is used to establish a state-space model based on the collected real-time electrical parameters, and the SOC is dynamically estimated to obtain the dynamic estimate value.

[0057] Specifically, the Extended Kalman Filter (EKF) algorithm is used to dynamically estimate the State of Charge (SOC). This algorithm establishes a state-space model based on the high-frequency acquired terminal voltage U, charging / discharging current I, and temperature T, where the state equation is x. k =Ax k-1 +Bu k-1 +w k-1 The observation equation is y k =Cx k +v k State vector x k Includes SOC value and battery internal resistance R, input quantity u k-1 Let I be the charging / discharging current at time k-1, and let y be the observed value. k Let U be the terminal voltage at time k, and A, B, and C be the state matrix, input matrix, and observation matrix, respectively. k-1 v kThese are process noise and observation noise, respectively. Through recursive calculations of the state equation and observation equation, the algorithm can predict and correct the SOC value in real time, effectively suppressing measurement noise and system errors. It achieves high-precision tracking and estimation of SOC in rapidly changing collision scenarios and outputs a dynamic SOC estimate value, SOC_ekf.

[0058] (3) Calculate the instantaneous collision current compensation coefficient based on the relationship between real-time charging and discharging current and rated discharge current.

[0059] Specifically, based on the currently collected real-time charging / discharging current I and rated discharging current I... n Calculate the instantaneous current compensation coefficient K during the collision i The calculation formula is: K i =1+(I / I n )×0.05(5) This coefficient is used to compensate for the nonlinear deviation caused by internal resistance voltage drop and polarization effect in instantaneous high current discharge scenarios. The larger the current, the larger the compensation coefficient, thereby ensuring the accuracy of SOC estimation under high current impact conditions.

[0060] (4) After correcting the dynamic estimate by using the aging compensation coefficient and the collision instantaneous current compensation coefficient, the SOC estimate is obtained.

[0061] Specifically, using the aging compensation coefficient K a and the instantaneous current compensation coefficient K during the collision i The SOC dynamic estimate SOC_ekf output by the extended Kalman filter algorithm is corrected to obtain the SOC estimate SOC3 under the collision emergency condition: SOC3 = SOC_ekf × K a ×K i (6) Among them, the aging compensation coefficient K a Based on the number of charge / discharge cycles N of the backup battery and the rated number of cycles N n Calculate, the formula is K a =1-(N / N n )×0.1, the higher the degree of aging, the more K a The smaller the value, the better it is used to compensate for the impact of battery performance degradation over its entire life cycle on SOC estimation. Through the joint correction of dual coefficients, the impact of battery aging and instantaneous high-current discharge on SOC estimation accuracy is effectively offset, ensuring high accuracy and high reliability of SOC estimation under collision emergency conditions.

[0062] In some optional implementations, the method further includes: performing a reasonableness check on the obtained SOC estimate based on a preset range; if the SOC estimate is within the preset range, outputting the current SOC estimate; if the SOC estimate is outside the preset range, using the last valid SOC value as a temporary output, and returning to the step of "obtaining the external collision signal and the real-time electrical parameters of the vehicle backup battery, and determining the current operating condition of the vehicle backup battery".

[0063] Specifically, the preset reasonable range for the SOC value is 0% to 100%. After obtaining an estimated SOC value through any of the above estimation strategies, it is first determined whether the estimated value falls within the preset range of 0% to 100%. If the estimated SOC value is within this range, it indicates that the estimation result is reasonable and valid. The estimated SOC value is then output to the execution unit of the collision unlocking module to determine whether the backup battery has the power supply capability for unlocking. If the estimated SOC value exceeds the range of 0% to 100%, it indicates that the estimation result is abnormal, possibly due to sensor failure, abnormal data acquisition, or algorithm calculation deviation. In this case, the system does not use the abnormal value but instead retrieves the previously valid SOC value as a temporary output to ensure the continuity of subsequent judgments. Simultaneously, it returns to the steps of acquiring the external collision signal and the real-time electrical parameters of the vehicle's backup battery, determining the current operating condition of the backup battery, re-acquiring parameters, and performing SOC estimation to restore the normal estimation state as quickly as possible. This reasonableness verification mechanism effectively avoids misjudgments caused by abnormal estimation values, ensuring the reliability and safety of the collision unlocking module's decision-making.

[0064] In some optional implementations, the method further includes: recording the operating data of the vehicle backup battery according to a preset cycle, the operating data including at least the charging and discharging data, temperature data, number of cycles, and SOC estimate of the vehicle backup battery; updating the inherent parameters based on the records and optimizing the mapping relationship library; and triggering a fault warning signal when the number of cycles reaches the rated number of cycles or the error of the SOC estimate continues to exceed a preset threshold.

[0065] Specifically, the system also includes steps for adaptive parameter updates and fault monitoring. The system records the operating data of the vehicle's backup battery at a preset cycle. This data includes at least charge / discharge data, temperature data, cycle count, and SOC estimate. Based on the recorded historical data, the system dynamically updates the temperature compensation coefficient and aging compensation coefficient in the inherent parameters and optimizes the mapping database to adapt to changes in battery characteristics under different ambient temperatures and aging conditions, achieving adaptive improvement in estimation accuracy. Simultaneously, the system monitors the battery status in real time: when the battery's cycle count reaches the rated cycle count, it indicates that the battery is nearing the end of its service life, triggering a fault warning signal to remind the user to replace it promptly; when the error of the SOC estimate continuously exceeds a preset threshold (e.g., 2%), it indicates that the estimation accuracy can no longer meet the usage requirements, also triggering a fault warning signal. This parameter update and fault monitoring mechanism effectively ensures the accuracy and reliability of SOC estimation throughout its entire lifecycle, providing continuous and stable data support for judging the emergency power supply capability of the collision unlocking module.

[0066] This embodiment also provides a device for estimating the State of Charge (SOC) of an on-board backup battery. This device is used to implement the above embodiments and preferred embodiments, and details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0067] This embodiment provides a device for estimating the State of Charge (SOC) of an onboard backup battery, such as... Figure 2 As shown, it includes: The mapping relationship construction module 201 is used to establish a mapping relationship library between the electrical parameters of the vehicle backup battery under different characteristics and the SOC based on the inherent parameters of the vehicle backup battery.

[0068] The operating condition identification and judgment module 202 is used to acquire external collision signals and real-time electrical parameters of the vehicle's backup battery, and to determine the current operating condition of the vehicle's backup battery.

[0069] The estimation strategy matching module 203 is used to estimate the SOC based on the current operating conditions and adopt the corresponding SOC estimation strategy. The SOC estimation strategy includes searching the mapping relationship library based on real-time electrical parameters or dynamically calculating real-time electrical parameters.

[0070] The on-board backup battery SOC estimation device provided in this embodiment of the invention can execute the method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for executing the method. Further functional descriptions of the various modules and units are the same as in the corresponding embodiments described above, and will not be repeated here.

[0071] Figure 3This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0072] The following is a detailed reference. Figure 3 The diagram illustrates a structural schematic suitable for implementing an electronic device according to embodiments of the present invention. The electronic device may include a processor (e.g., a central processing unit, graphics processor, etc.) 001, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 002 or a program loaded from memory 008 into random access memory (RAM) 003. The RAM 003 also stores various programs and data required for the operation of the electronic device. The processor 001, ROM 002, and RAM 003 are interconnected via bus 004. An input / output (I / O) interface 005 is also connected to bus 004.

[0073] Typically, the following devices can be connected to I / O interface 005: input devices 006 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 007 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 008 including, for example, magnetic tapes, hard disks, etc.; and communication devices 009. Communication device 009 allows electronic devices to exchange data via wireless or wired communication with other devices. Although Figure 3 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.

[0074] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication device 009, or installed from memory 008, or installed from ROM 002. When the computer program is executed by processor 001, it performs the functions defined in the methods of the embodiments of the present invention.

[0075] Figure 3 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.

[0076] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0077] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0078] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for estimating the State of Charge (SOC) of an onboard backup battery, characterized in that, include: Based on the inherent parameters of the vehicle backup battery, a mapping relationship library between the electrical parameters and SOC of the vehicle backup battery under different characteristics is established. Acquire external collision signals and real-time electrical parameters of the vehicle backup battery to determine the current operating condition of the vehicle backup battery; Based on the current operating conditions, a corresponding SOC estimation strategy is adopted to estimate the SOC; wherein, the SOC estimation strategy includes searching the mapping relationship library based on the real-time electrical parameters, or dynamically calculating the real-time electrical parameters.

2. The method according to claim 1, characterized in that, The inherent parameters include one or more of the following: rated capacity, sleep / wake-up threshold, collision signal threshold, temperature compensation coefficient, aging compensation coefficient, and ampere-hour integral coefficient; the electrical parameters include one or more of the following: terminal voltage, charging / discharging current, and battery temperature; the process of establishing a mapping library between the electrical parameters and SOC of the on-board backup battery under different characteristics includes: A mapping library of electrical parameters and SOC of the vehicle backup battery under different temperatures and aging levels was established, and the mapping library was calibrated through offline experiments.

3. The method according to claim 2, characterized in that, The process of acquiring external collision signals and real-time electrical parameters of the vehicle's backup battery, and determining the current operating condition of the backup battery, includes: Based on the external collision signal and the real-time electrical parameters, the system identifies whether the vehicle's backup battery is currently in standby / dormant mode, wake-up detection mode, or collision emergency mode; wherein... When the external collision signal is a first preset signal and the real-time electrical parameters meet the first preset conditions, it is determined to be in standby sleep mode. When the external collision signal is a first preset signal and the real-time electrical parameters meet the second preset conditions, it is determined to be a wake-up detection condition; When the external collision signal is the second preset signal or the real-time electrical parameters meet the third preset condition, it is determined to be a collision emergency condition.

4. The method according to claim 3, characterized in that, When the system is determined to be in standby or hibernation mode, the process of estimating SOC based on the real-time electrical parameters by searching the mapping database includes: The basic SOC value is obtained by searching the mapping database based on the collected electrical parameters. After correcting the base SOC value using the inherent parameters, an estimated SOC value is obtained. The current SOC estimate is used as the base SOC value for the next estimate, and the process returns to the step of "correcting the base SOC value using the inherent parameters" after a preset time interval.

5. The method according to claim 4, characterized in that, Under standby / sleep conditions, the formula for calculating the estimated SOC value is as follows: SOC1=f(U0,T0)×K t0 Where U0 is the terminal voltage; T0 is the battery temperature; K t0 is the temperature compensation coefficient; SOC1 is the estimated SOC value; f(U0,T0) is the base SOC value.

6. The method according to claim 3, characterized in that, When the system is determined to be in wake-up detection mode, the process of estimating SOC based on the mapping database using the real-time electrical parameters includes: Obtain the preset initial SOC value; Based on the initial SOC value, the preliminary estimate of SOC is calculated using the ampere-hour integration method; The basic SOC value is obtained by searching the mapping relationship library based on the collected real-time electrical parameters, and the basic SOC value is corrected using the inherent parameters to obtain the calibration value. The preliminary SOC estimate is weighted and fused with the calibration value to obtain the SOC estimate. The current SOC estimate is used as the initial SOC estimate for the next estimation, and the process returns to the step of "calculating the preliminary SOC estimate using the ampere-hour integration method based on the initial SOC value" after a preset time interval.

7. The method according to claim 6, characterized in that, Under wake-up detection conditions, the formula for calculating the SOC estimate is as follows: SOC2'=SOC2×α+SOC_cal×β SOC_cal=f(U0,T0)×K t0 Where SOC2' is the estimated SOC value; SOC2 is the preliminary estimated SOC value; SOC_cal is the calibration value; U0 is the terminal voltage; T0 is the battery temperature; K t0 α is the temperature compensation coefficient; f(U0,T0) is the basic SOC value; α and β are weighting coefficients, and α+β=1.

8. The method according to claim 3, characterized in that, When a collision emergency is identified, the process of dynamically calculating the real-time electrical parameters to estimate the State of Charge (SOC) includes: Increase the frequency of electrical parameter acquisition; A filtering algorithm is used to establish a state-space model based on the collected real-time electrical parameters, and the SOC is dynamically estimated to obtain the dynamic estimate value. The collision instantaneous current compensation coefficient is calculated based on the relationship between the real-time charging and discharging current and the rated discharging current. After correcting the dynamic estimate using the aging compensation coefficient and the instantaneous impact current compensation coefficient, the SOC estimate is obtained.

9. The method according to claim 1, characterized in that, Also includes: The reasonableness of the obtained SOC estimate is verified based on the preset range; If the SOC estimate is within the preset range, then output the current SOC estimate. If the estimated SOC value is outside the preset range, the last valid SOC value is used as a temporary output, and the process of "obtaining the external collision signal and the real-time electrical parameters of the vehicle backup battery, and determining the current operating condition of the vehicle backup battery" is returned.

10. The method according to claim 1, characterized in that, Also includes: Record the working data of the vehicle backup battery according to a preset cycle. The working data includes at least the charging and discharging data, temperature data, number of cycles and estimated SOC value of the vehicle backup battery. The inherent parameters are updated based on the records, and the mapping relationship library is optimized. When the number of cycles reaches the rated number of cycles, or the error of the SOC estimation value continues to exceed the preset threshold, a fault warning signal is triggered.

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