Automobile battery management system control method and device, vehicle and medium

Abstract

The application discloses a kind of automobile battery management system control method, device, vehicle and medium, comprising: through the analog front end that is set in battery management system, bus current is collected with not higher than preset first sampling cycle threshold sampling cycle by shunt, and using digital signal processor, fast fourier transform is carried out to bus current, and ripple amplitude and ripple frequency are obtained;If ripple amplitude and ripple frequency satisfy preset mode determination condition, it is determined to enter strong ripple interference mode;The consistency fault threshold of independent current sensor is dynamically raised from basic threshold to obtain dynamic protection threshold, and fault recovery counter is extended, simultaneously, the voltage sampling main auxiliary link voltage difference fault threshold is raised to preset voltage difference interval, and software filtering is started to current and voltage sampling value;When ripple weakens and continues to exceed preset first duration threshold, exit strong ripple interference mode and restore threshold.

Description

Technical Field

[0001] This application relates to the field of new energy vehicle power battery management system technology, and in particular to a control method, device, vehicle and medium for an automotive battery management system. Background Technology

[0002] When new energy vehicles travel at high speeds, the generator or drive motor generates high-frequency ripple current. This ripple couples to the high-voltage DC bus, directly interfering with the current and voltage sampling of the Battery Management System (BMS). Currently, BMS bus current measurement generally follows two paths: one is an independent current sensor (e.g., LEM CAB1500), which sends current data to the BMS via the Controller Area Network (CAN) bus for State of Charge (SOC) estimation and functional safety monitoring; this sensor has multiple range channels, and the consistency of the difference between any two range channels is compared to determine if a fault exists; the other path is for the analog front-end (AFE) inside the BMS to directly sample the current via a shunt. This path offers fast sampling (microseconds) and can capture high-frequency ripple. For voltage sampling, the BMS acquires the cell voltage through a voltage sampling chip (e.g., 79616) and uses the difference between the main and auxiliary links to determine if the voltage acquisition is normal.

[0003] However, the response speeds of individual current sensors differ across channels. If the instantaneous deviation exceeds a threshold (e.g., 15A), a "consistency error" is reported, leading to vehicle power limitation. Ripple causes instantaneous voltage jumps in the battery cells; if the BMS voltage sampling difference exceeds the calibrated value (e.g., 99mV), an "arbitrary cell voltage acquisition fault" is reported, directly limiting power to zero and causing the vehicle to lose power. Current practices do not address these issues in a coordinated manner at the system level, nor do they utilize the AFE's high-speed sampling path to identify ripple.

[0004] Therefore, how to suppress false alarms caused by high-frequency ripple of electric drive to BMS sampling at the system level, avoid unexpected power limiting or even power interruption, and at the same time not reduce the functional safety level is an important issue in the field of new energy vehicle battery management. Summary of the Invention

[0005] The purpose of this application is to provide a control method, device, vehicle and medium for an automotive battery management system, which can suppress false alarms of independent current sensor consistency and false alarms of voltage sampling cell voltage caused by high-frequency ripple of electric drive without replacing hardware or reducing functional safety, thereby avoiding unexpected power limitation and power interruption.

[0006] To achieve the above objectives: In a first aspect, embodiments of this application provide a control method for an automotive battery management system, including: The bus current is collected by the analog front-end set inside the battery management system through the shunt at a sampling period not higher than the preset first sampling period threshold. The bus current is then subjected to fast Fourier transform by the digital signal processor to calculate the ripple amplitude and ripple frequency. The sampling path of the analog front-end is independent of the controller local area network bus and does not interfere with the original functions of the independent current sensor for state of charge estimation and functional safety monitoring. If the ripple amplitude and the ripple frequency meet the preset mode determination conditions, then it is determined that the strong ripple interference mode is entered. In response to entering the strong ripple interference mode, the consistency fault threshold of the independent current sensor is dynamically increased from the basic threshold to obtain a dynamic protection threshold, wherein the dynamic protection threshold is equal to the basic threshold plus the product of a coefficient and the ripple amplitude, the coefficient is a preset coefficient and the value range is a preset coefficient interval, and the fault recovery counter is extended from a preset first recovery count threshold to a preset second recovery count threshold. At the same time, the fault threshold of the main and auxiliary link voltage difference of voltage sampling is increased from a preset basic voltage difference threshold to a preset voltage difference interval, and software filtering with a window of integer multiple of the ripple period is initiated for the current and voltage sampling values. When the ripple amplitude is less than a preset second current threshold and the ripple frequency is less than a preset second frequency threshold and continues to exceed a preset first duration threshold, the strong ripple interference mode is exited, and the consistency fault threshold and the voltage difference fault threshold are gradually restored to their original values ​​to return to normal functional safety diagnostic logic.

[0007] In one embodiment, the method of acquiring the bus current via a shunt through an analog front-end set within the battery management system at a sampling period not exceeding a preset first sampling period threshold, and using a digital signal processor to perform a fast Fourier transform on the bus current to calculate the ripple amplitude and ripple frequency, includes: The bus current is collected through the shunt channel of the analog front end at a sampling period not higher than the preset first sampling period threshold. The ripple amplitude and ripple frequency are obtained by separating and calculating the bus current using the digital signal processor via Fast Fourier Transform.

[0008] In one embodiment, determining that a strong ripple interference mode is entered if the ripple amplitude and the ripple frequency meet a preset mode determination condition includes at least one of the following: When the ripple frequency is not less than a preset first frequency threshold and the ripple amplitude is not less than a preset first current threshold, it is determined that the strong ripple interference mode is entered. When the difference between any two range channels inside the independent current sensor fluctuates periodically, and the frequency difference between the fluctuation frequency and the operating frequency of the electric drive is less than a preset frequency deviation threshold, it is determined that the strong ripple interference mode is entered.

[0009] In one embodiment, the step of dynamically adjusting the consistency fault threshold of the independent current sensor from the base threshold to obtain the dynamic protection threshold includes: The basic threshold is taken as the basic determination threshold of the difference between the high-medium channel or the high-low channel of the independent current sensor, and its value is a preset basic determination threshold. The dynamic protection threshold is dynamically calculated according to the formula based on the ripple amplitude and coefficient.

[0010] In one embodiment, adjusting the fault threshold for the voltage difference between the primary and secondary links in voltage sampling from a preset base voltage difference threshold to a preset voltage difference range includes: The voltage difference fault threshold is calibrated based on the cell polarization voltage fluctuation under ripple, and the voltage difference fault threshold is adjusted from the preset basic voltage difference threshold to the preset voltage difference range.

[0011] In one embodiment, the software filtering that initiates the current and voltage sampling values ​​within an integer multiple of the ripple period includes: The current sample value and the voltage sample value are subjected to median filtering or moving average filtering, wherein the filtering window is an integer multiple of the ripple period and the value range is from a preset first window period number to a preset second window period number.

[0012] In one embodiment, the dynamic adjustment of the consistency fault threshold and the dynamic adjustment of the voltage difference fault threshold are performed synchronously based on the ripple amplitude and the ripple frequency, so as to simultaneously avoid the consistency false alarm of the independent current sensor and the cell voltage acquisition fault false alarm of the voltage sampling.

[0013] Secondly, embodiments of this application provide a control device for an automotive battery management system, comprising: The sampling and calculation module is used to collect the bus current through the analog front end set inside the battery management system via the shunt at a sampling period not higher than the preset first sampling period threshold, and to use the digital signal processor to perform a fast Fourier transform on the bus current to calculate the ripple amplitude and ripple frequency. The sampling path of the analog front end is independent of the controller local area network bus and does not interfere with the original functions of the independent current sensor for state of charge estimation and functional safety monitoring. The mode determination module is used to determine that if the ripple amplitude and the ripple frequency meet the preset mode determination conditions, then the strong ripple interference mode is entered. The anti-ripple protection module is used to respond to entering the strong ripple interference mode by dynamically increasing the consistency fault threshold of the independent current sensor from the basic threshold to obtain a dynamic protection threshold, wherein the dynamic protection threshold is equal to the basic threshold plus the product of a coefficient and the ripple amplitude, the coefficient being a preset coefficient and the value range being a preset coefficient interval, and extending the fault recovery counter from a preset first recovery count threshold to a preset second recovery count threshold, while increasing the fault threshold of the main and auxiliary link voltage difference of voltage sampling from a preset basic voltage difference threshold to a preset voltage difference interval, and initiating software filtering of the current and voltage sampling values ​​with a window that is an integer multiple of the ripple period; The exit recovery module is used to exit the strong ripple interference mode when the ripple amplitude is less than the preset second current threshold and the ripple frequency is less than the preset second frequency threshold and continues to exceed the preset first duration threshold, and gradually restores the consistency fault threshold and the voltage difference fault threshold to their original values ​​to return to normal functional safety diagnostic logic.

[0014] Thirdly, embodiments of this application provide a vehicle, specifically including: a processor; a memory for storing processor-executable instructions; wherein the processor is configured to execute the instructions to implement the vehicle battery management system control method as described in the first aspect, or to include the vehicle battery management system control method as described in the first aspect.

[0015] Fourthly, embodiments of this application provide a machine-readable storage medium storing a computer program, wherein when the instructions in the machine-readable storage medium are executed by a processor, the vehicle battery management system control method as described in the first aspect is implemented.

[0016] This application provides a control method, device, vehicle, and medium for an automotive battery management system, comprising: acquiring bus current through a shunt at a sampling period not exceeding a preset first sampling period threshold via an analog front-end set within the battery management system; performing a fast Fourier transform on the bus current using a digital signal processor to obtain ripple amplitude and ripple frequency; determining entry into a strong ripple interference mode if the ripple amplitude and ripple frequency meet preset mode determination conditions; dynamically adjusting the consistency fault threshold of the independent current sensor from a basic threshold to obtain a dynamic protection threshold, extending the fault recovery counter, simultaneously adjusting the main and auxiliary link voltage difference fault threshold of voltage sampling to a preset voltage difference range, and initiating software filtering for current and voltage sampling values; exiting the strong ripple interference mode and restoring the threshold when the ripple weakens and continues to exceed a preset first duration threshold. Through the above method, false alarms caused by high-frequency ripple in the electric drive can be suppressed without replacing hardware or reducing functional safety, avoiding unexpected power limiting and power interruption. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the control method for an automotive battery management system provided in an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the structure of the automotive battery management system control device provided in an embodiment of the present invention.

[0019] Figure 3 This is a structural schematic diagram of a vehicle provided in an embodiment of the present invention.

[0020] Processor 410, memory 411, network interface 412, bus system 413. Detailed Implementation

[0021] 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.

[0022] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, components, features, and elements with the same names in different embodiments of this application may have the same meaning or different meanings, the specific meaning of which must be determined by its interpretation in that specific embodiment or further in conjunction with the context of that specific embodiment.

[0023] It should be understood that although the terms first, second, third, etc., may be used herein to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this document, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if," as used herein, can be interpreted as "when," "when," or "in response to determination." Furthermore, as used herein, the singular forms "a," "an," and "the" are intended to also include the plural forms unless the context indicates otherwise. It should be further understood that the terms "comprising," "including," indicate the presence of the stated feature, step, operation, element, component, item, kind, and / or group, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, kinds, and / or groups. The terms "or" and "and / or" as used herein are to be interpreted as inclusive, or mean any one or any combination thereof. Therefore, "A, B, or C" or "A, B, and / or C" means "any one of the following: A; B; C; A and B; A and C; B and C; A, B, and C". Exceptions to this definition will only occur if the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way.

[0024] It should be understood that although the steps in the flowcharts of this application's embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in the figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of the sub-steps or stages of other steps.

[0025] It should be noted that step designations such as S101 and S102 are used in this document for the purpose of more clearly and concisely describing the corresponding content, and do not constitute a substantial limitation on the order. In specific implementation, those skilled in the art may execute S102 first and then S101, etc., but these should all be within the protection scope of this application.

[0026] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0027] In the following description, the use of suffixes such as "module," "part," or "unit" to denote elements is solely for the purpose of illustrative purposes and has no specific meaning in itself. Therefore, "module," "part," or "unit" may be used interchangeably.

[0028] It should be noted that currently, the current and voltage sampling of the BMS in new energy vehicles mainly relies on two existing channels: independent current sensors (reported via CAN) and voltage sampling chips (main and auxiliary link difference). Their diagnostic thresholds are statically calibrated. However, the high-frequency ripple generated by the electric drive system can couple into both types of sampling, creating a difficult-to-distinguish problem: blindly increasing the threshold can mask real faults and reduce functional safety; replacing the sensor is costly and time-consuming. The existing technology lacks the ability to utilize the existing high-speed sampling path of the BMS to identify ripple and to handle the aforementioned false alarms in conjunction with other technologies, resulting in frequent unexpected power limiting or even power interruption in durable and mass-produced vehicles under high-speed conditions.

[0029] To address the aforementioned issues, this application proposes a control method for an automotive battery management system that resists high-frequency ripple interference. This method allows vehicles to extract the amplitude and frequency of bus ripple in real time using the high-speed sampling channel of the analog front end within the BMS via the shunt. Strong ripple interference is identified through preset mode judgment conditions, and the consistency threshold of independent current sensors and the voltage sampling difference threshold are dynamically adjusted in conjunction with software filtering. This suppresses false alarms without sacrificing functional safety and can be widely applied to active anti-interference scenarios of battery management systems in various hybrid or pure electric vehicles.

[0030] like Figure 1 As shown, this application provides a control method for an automotive battery management system. This method can be implemented in software and / or hardware, such as an anti-ripple interference controller within the battery management system. This embodiment uses a vehicle battery management system integrating an analog front-end and a digital signal processor as an example. The automotive battery management system control method provided in this application includes the following steps: Step S101: The bus current is collected by the analog front-end set inside the battery management system through the shunt at a sampling period not higher than the preset first sampling period threshold. The bus current is then subjected to fast Fourier transform by the digital signal processor to calculate the ripple amplitude and ripple frequency. The sampling path of the analog front-end is independent of the controller local area network bus and does not interfere with the original functions of the independent current sensor for state of charge estimation and functional safety monitoring.

[0031] Optionally, the analog front-end (AFE) can refer to an analog front-end chip integrated within the battery management system for directly sampling the shunt voltage at high speed; the shunt can refer to a low-resistance sampling resistor connected in series with the bus; the digital signal processor (DSP) can refer to a computational unit that performs a fast Fourier transform (FFT) on the sampled sequence; the ripple amplitude can refer to the peak or effective value of the high-frequency AC component superimposed on the bus current; and the ripple frequency can refer to the fundamental frequency of the high-frequency AC component.

[0032] Optionally, the sampling path of the analog front end is independent of the controller area network bus, which means that the high-speed sampling channel is not transmitted through the CAN bus, and therefore is not limited by the CAN bandwidth, and can capture microsecond-level high-frequency ripple; the current data reported by the independent current sensor (e.g., CAB1500) via CAN is still dedicated to state of charge estimation and functional safety monitoring, and the two do not interfere with each other.

[0033] In some implementations, step S101, which involves acquiring the bus current via a shunt through an analog front-end set within the battery management system at a sampling period not exceeding a preset first sampling period threshold, and performing a fast Fourier transform on the bus current using a digital signal processor to calculate the ripple amplitude and ripple frequency, includes: acquiring the bus current via the shunt channel of the analog front-end at a sampling period not exceeding a preset first sampling period threshold; and separating and calculating the ripple amplitude and ripple frequency from the bus current using a fast Fourier transform by the digital signal processor.

[0034] Optionally, the preset first sampling period threshold can be calibrated to no more than 10 microseconds (i.e., the upper limit of the sampling period is 10μs, corresponding to a sampling frequency of no less than 100 kHz) to meet the requirements for aliasing-free capture of high-frequency ripples in the thousands of hertz.

[0035] In the above implementation, by reusing the high-speed channel of the existing analog front-end splitter in the BMS to identify ripple, it does not interfere with the original functional safety main link, and solves the problem that the CAN bandwidth is insufficient to detect high-frequency ripple. It provides a reliable ripple feature input for subsequent linkage processing, and no new hardware is required, which is low-cost and easy to deploy.

[0036] Step S102: If the ripple amplitude and ripple frequency meet the preset mode determination conditions, then it is determined to enter the strong ripple interference mode.

[0037] Optionally, the preset mode determination conditions may refer to a set of calibrable criteria used to distinguish between "strong ripple interference" and "normal operating conditions"; the strong ripple interference mode may refer to the working state of temporarily switching the diagnostic strategy and relaxing the threshold of the two types of faults during the period when strong ripple is identified.

[0038] Optionally, the preset mode determination conditions include at least the following two preset types: Condition A (frequency / amplitude both exceed threshold) and Condition B (the difference between the two channels fluctuates periodically and is related to the electric drive frequency).

[0039] In some implementations, step S102, i.e., determining to enter a strong ripple interference mode if the ripple amplitude and the ripple frequency meet preset mode determination conditions, includes at least one of the following: determining to enter the strong ripple interference mode when the ripple frequency is not less than a preset first frequency threshold and the ripple amplitude is not less than a preset first current threshold; determining to enter the strong ripple interference mode when the difference between any two range channels inside the independent current sensor fluctuates periodically and the frequency difference between the fluctuation frequency and the electric drive operating frequency is less than a preset frequency deviation threshold.

[0040] Optionally, the preset first frequency threshold can be calibrated to 500Hz, and the preset first current threshold can be calibrated to 50A; both are calibrable parameters. The preset frequency deviation threshold is a calibrable parameter, such as ± a preset percentage (e.g., ±20%) of the electric drive operating frequency or a preset Hertz range (e.g., not greater than 50Hz), used to quantify the strong correlation between "fluctuation frequency and electric drive operating frequency".

[0041] In the above implementation, the strong ripple interference mode is entered by dual criteria, namely condition A (directly based on ripple amplitude / frequency) and condition B (based on the periodic fluctuation of the internal channel difference of the independent current sensor), which enhances the reliability of pattern recognition. It can be quickly triggered under high frequency and large ripple conditions, and can also capture the working condition where the sensor channel response is transformed into low frequency difference fluctuation, thereby avoiding missed detection by a single criterion.

[0042] In step S103, in response to entering the strong ripple interference mode, the consistency fault threshold of the independent current sensor is dynamically increased from the basic threshold to obtain the dynamic protection threshold, wherein the dynamic protection threshold is equal to the basic threshold plus the product of the coefficient and the ripple amplitude, the coefficient is a preset coefficient and the value range is a preset coefficient interval, and the fault recovery counter is extended from the preset first recovery count threshold to the preset second recovery count threshold. At the same time, the fault threshold of the main and auxiliary link voltage difference of voltage sampling is increased from the preset basic voltage difference threshold to the preset voltage difference interval, and software filtering with a window of integer multiple of the ripple period is started for the current and voltage sampling values.

[0043] Optionally, the dynamic protection threshold may refer to the target threshold after the consistency fault threshold is temporarily increased during strong ripple; the base threshold may refer to the base judgment threshold (i.e., the preset base judgment threshold) of the difference between the high-medium channel or high-low channel of the independent current sensor under normal operating conditions; the coefficient may refer to the preset proportional factor used to correct the threshold according to the ripple amplitude; the preset voltage difference range may refer to the target range for increasing the voltage sampling main and auxiliary link difference fault threshold during strong ripple, which is defined by the preset first voltage difference threshold and the preset second voltage difference threshold.

[0044] In some implementations, step S103, i.e., in response to entering the strong ripple interference mode, dynamically increases the consistency fault threshold of the independent current sensor from the base threshold to obtain a dynamic protection threshold, wherein the dynamic protection threshold is equal to the base threshold plus the product of a coefficient and the ripple amplitude, the coefficient being a preset coefficient and its value range being a preset coefficient interval, and extends the fault recovery counter from a preset first recovery count threshold to a preset second recovery count threshold, simultaneously increasing the fault threshold of the main and auxiliary link voltage difference in voltage sampling from a preset base voltage difference threshold to a preset voltage difference interval, and initiating software filtering of the current and voltage sampling values ​​with a window that is an integer multiple of the ripple period, includes: The consistency fault threshold of the independent current sensor is dynamically adjusted from the base threshold to obtain the dynamic protection threshold. Specifically: the base threshold is taken as the base judgment threshold for the difference between the high-medium channel or the high-low channel of the independent current sensor, and its value is a preset base judgment threshold; the dynamic protection threshold is dynamically calculated according to the formula based on the ripple amplitude and coefficient; the coefficient is a preset coefficient and its value range is a preset coefficient interval (e.g., 0.1~0.3, preferably 0.2); simultaneously, the fault recovery counter is extended from a preset first recovery count threshold to a preset second recovery count threshold (e.g., extended from 40ms to 100ms) to filter out transient interference. Adjusting the voltage difference fault threshold of the main and auxiliary links of voltage sampling from a preset basic voltage difference threshold to a preset voltage difference range includes: calibrating the voltage difference fault threshold based on the cell polarization voltage fluctuation under ripple, and adjusting the voltage difference fault threshold from the preset basic voltage difference threshold to a preset voltage difference range (e.g., 300mV~1000mV, preferably 500mV, without affecting the actual overvoltage / undervoltage protection). The software filtering for the current and voltage sample values, with the starting window being an integer multiple of the ripple period, includes: applying median filtering or moving average filtering to the current and voltage sample values, wherein the filtering window is an integer multiple of the ripple period and the value range is from a preset first window period number to a preset second window period number (e.g., 3 to 5 ripple periods).

[0045] In some implementations, in step S103, the dynamic adjustment of the consistency fault threshold and the dynamic adjustment of the voltage difference fault threshold are performed synchronously based on the ripple amplitude and the ripple frequency, so as to simultaneously avoid the consistency false alarm of the independent current sensor and the cell voltage acquisition fault false alarm of the voltage sampling.

[0046] In the above implementation, by synchronously triggering three types of actions—"dynamically increasing the consistency threshold according to the formula," "increasing the voltage difference threshold to the preset range," and "software filtering"—based on the same ripple amplitude / frequency, all instantaneous deviations caused by ripple fall within the relaxed threshold, thereby simultaneously avoiding two types of false alarms. The formula "dynamic protection threshold = basic threshold + coefficient × ripple amplitude" ensures that the threshold is always greater than the maximum channel deviation caused by ripple, and the extended recovery counter can filter out transient jitter. Overall, anti-interference is achieved without sacrificing functional safety.

[0047] Step S104: When the ripple amplitude is less than the preset second current threshold and the ripple frequency is less than the preset second frequency threshold and continues to exceed the preset first duration threshold, exit the strong ripple interference mode, and gradually restore the consistency fault threshold and voltage difference fault threshold to their original values ​​to return to the normal functional safety diagnostic logic.

[0048] In some implementations, step S104, i.e. when the ripple amplitude is less than a preset second current threshold and the ripple frequency is less than a preset second frequency threshold and continues to exceed a preset first duration threshold, exits the strong ripple interference mode and gradually restores the consistency fault threshold and the voltage difference fault threshold to their original values ​​to return to normal functional safety diagnostic logic.

[0049] Optionally, the preset second current threshold can be calibrated to 20A, the preset second frequency threshold can be calibrated to 300Hz, and the preset first duration threshold can be calibrated to 5 seconds; the threshold recovery adopts a gradual decreasing method to avoid frequent switching.

[0050] In the above implementation, by setting clear exit conditions and a gradual recovery mechanism, the diagnostic logic is ensured to return to normal in a timely manner after the strong ripple disappears, and the real fault can still be captured normally, so as not to reduce the vehicle safety integrity level (ASIL).

[0051] In summary, the above implementation method, by reusing the existing high-speed sampling path of the BMS to identify ripple and adjusting the fault thresholds of the two systems in conjunction, can suppress two types of false alarms caused by high-frequency ripple without replacing hardware or reducing functional safety, thereby avoiding unexpected power limiting and power interruption, and improving the robustness of the battery management system and driving safety.

[0052] Based on the same methodological concept as the foregoing embodiments, the foregoing embodiments will be described in detail below through a specific example.

[0053] The specific embodiments of this application aim to construct a battery management system based on the existing sampling channels of the BMS, which is resistant to high-frequency ripple interference from electric drives. The following will provide a detailed description of the system architecture, core modules, workflow, and timing, and will also illustrate the core content that should be shown in each of the accompanying drawings.

[0054] I. System Overall Architecture This system is primarily deployed in the battery management system (BMS) of new energy vehicles. It is an embedded system integrating high-speed sampling, ripple recognition, threshold linkage, and state control. Its overall architecture can be divided into three layers: Sampling layer: Composed of analog front-end (AFE) and shunt inside BMS, independent of the controller LAN bus, it collects raw bus current data in microsecond cycles, i.e., performs the above step S101, and extracts ripple amplitude and ripple frequency through fast Fourier transform by digital signal processor (DSP).

[0055] Identification Decision Layer: This is the core processing unit that runs the ripple feature identification, mode determination, adaptive threshold adjustment and state machine control logic of this application, that is, it executes the above steps S102 and S103, determines whether it has entered the strong ripple interference mode and calculates the dynamic protection threshold, voltage difference threshold and filtering parameters in conjunction.

[0056] Execution layer: provides a diagnostic threshold configuration interface for independent current sensors (e.g., CAB1500) and voltage sampling chips (e.g., 79616), as well as a software filtering module; receives instructions from the decision layer and updates the consistency fault threshold, voltage difference fault threshold, and recovery counter according to the calculation results, i.e., executes the exit and recovery of the above step S104.

[0057] The information flow of the entire system is as follows: from the physical current of the bus to the sampling of the AFE shunt to the extraction of ripple features by the DSP fast Fourier transform to the mode determination and threshold linkage decision to the threshold / filter configuration to the suppression of two types of false alarms and the ability to still diagnose real faults.

[0058] II. Detailed Description of Core Module Functions 1. Ripple Feature Recognition Module Function: By simulating the front end and sampling the bus current at high speed through the shunt, the ripple amplitude and ripple frequency are separated and calculated by the digital signal processor using fast Fourier transform.

[0059] Input: Analog bus current (converted to voltage via a shunt).

[0060] Processing and Output: Outputs a (ripple amplitude, ripple frequency) tuple, which serves as the trigger for subsequent mode determination and threshold linkage. This sampling path is independent of the controller LAN bus and does not interfere with the original functions of the independent current sensor for state of charge estimation and functional safety monitoring.

[0061] 2. Adaptive threshold adjustment module Function: Based on ripple characteristics, dynamically adjust the independent current sensor consistency fault threshold and the voltage sampling main and auxiliary link difference fault threshold.

[0062] Mapping strategy: The consistency fault threshold is calculated as "dynamic protection threshold = basic threshold + coefficient × ripple amplitude" (the coefficient is taken within a preset coefficient range, such as 0.1-0.3, preferably 0.2), ensuring that the threshold is always greater than the maximum channel deviation caused by ripple; at the same time, the voltage difference fault threshold is adjusted from the preset basic voltage difference threshold to the preset voltage difference range (such as 300mV-1000mV, preferably 500mV), and the fault recovery counter is extended (such as from 40ms to 100ms), and software filtering of an integer multiple of the ripple period is started for the current and voltage sampling values.

[0063] 3. State machine control module Function: Unified management of the state transition from "normal diagnosis → strong ripple protection → recovery". When strong ripple interference is detected, the system switches from the normal diagnosis state to the strong ripple protection state, executing the aforementioned threshold linkage. When the ripple weakens and continues to exceed a preset first duration threshold, the system recovers from the strong ripple protection state to the normal diagnosis state, and the threshold gradually returns to its original state. The state machine ensures that the threshold adjustment is temporary and conditional, and recovery occurs as soon as the interference disappears, thus not reducing the functional safety level.

[0064] Based on the same inventive concept as the foregoing embodiments, this invention provides a control device for an automotive battery management system, see below. Figure 2 The device includes: The sampling and calculation module 21 is used to collect the bus current through the analog front end set inside the battery management system via the shunt at a sampling period not higher than the preset first sampling period threshold, and to use the digital signal processor to perform a fast Fourier transform on the bus current to calculate the ripple amplitude and ripple frequency. The sampling path of the analog front end is independent of the controller local area network bus and does not interfere with the original functions of the independent current sensor for state of charge estimation and functional safety monitoring.

[0065] The mode determination module 22 is used to determine that if the ripple amplitude and ripple frequency meet the preset mode determination conditions, then the strong ripple interference mode is entered.

[0066] The anti-ripple protection module 23 is used to respond to entering the strong ripple interference mode by dynamically increasing the consistency fault threshold of the independent current sensor from the basic threshold to obtain a dynamic protection threshold. The dynamic protection threshold is equal to the basic threshold plus the product of a coefficient and the ripple amplitude. The coefficient is a preset coefficient and its value range is a preset coefficient interval. The fault recovery counter is extended from a preset first recovery count threshold to a preset second recovery count threshold. At the same time, the fault threshold of the main and auxiliary link voltage difference of voltage sampling is increased from a preset basic voltage difference threshold to a preset voltage difference interval. Software filtering is initiated for the current and voltage sampling values ​​with a window that is an integer multiple of the ripple period. The exit recovery module 24 is used to exit the strong ripple interference mode when the ripple amplitude is less than the preset second current threshold and the ripple frequency is less than the preset second frequency threshold and continues to exceed the preset first duration threshold. It also gradually restores the consistency fault threshold and voltage difference fault threshold to their original values ​​to return to the normal functional safety diagnostic logic.

[0067] It should be noted that the description of the above-mentioned vehicle battery management system control device is similar to the description of the above-mentioned vehicle battery management system control method, and the beneficial effects of the same method will not be repeated. For technical details not disclosed in the embodiments of the vehicle battery management system control device of this invention, please refer to the description of the embodiments of the vehicle battery management system control method of this invention.

[0068] Based on the same inventive concept as the foregoing embodiments, this invention provides a vehicle, such as... Figure 3 As shown, the vehicle includes: a processor 410 and a memory 411 storing a computer program; wherein, Figure 3 The processor 410 shown in the diagram does not indicate that there is only one processor 410, but only indicates the positional relationship of the processor 410 relative to other devices. In practical applications, there can be one or more processors 410; similarly, Figure 3 The memory 411 shown in the diagram has the same meaning, that is, it is only used to indicate the positional relationship of memory 411 relative to other devices. In practical applications, there can be one or more memories 411. When the processor 410 runs the computer program, the above-described automotive battery management system control method is implemented.

[0069] The vehicle may also include at least one network interface 412. Various components in the vehicle are coupled together via a bus system 413. It is understood that the bus system 413 is used to enable communication between these components. In addition to a data bus, the bus system 413 also includes a power bus, a control bus, and a status signal bus. However, for clarity, in... Figure 3 The general designated all buses as Bus System 413.

[0070] The memory 411 can be volatile or non-volatile, or both. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), ferromagnetic random access memory (FRAM), flash memory, magnetic surface memory, optical disc, or compact disc read-only memory (CD-ROM); magnetic surface memory can be disk storage or magnetic tape storage. Volatile memory can be random access memory (RAM), used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Synchronous Static Random Access Memory (SSRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), Double Data Rate Synchronous Dynamic Random Access Memory (DDRSDRAM), Enhanced Synchronous Dynamic Random Access Memory (ESDRAM), SyncLink Dynamic Random Access Memory (SLDRAM), and Direct Rambus Random Access Memory (DRRAM).The memory 411 described in the embodiments of the present invention is intended to include, but is not limited to, these and any other suitable types of memory.

[0071] The memory 411 in this embodiment of the invention is used to store various types of data to support the operation of the vehicle. Examples of this data include: any computer programs used to operate on the vehicle, such as operating systems and applications; contact data; phonebook data; messages; pictures; videos, etc. The operating system includes various system programs, such as a framework layer, core library layer, driver layer, etc., used to implement various basic services and handle hardware-based tasks. Applications can include various applications, such as media players, browsers, etc., used to implement various application services. Here, the program implementing the method of this embodiment of the invention can be included in the application.

[0072] Based on the same inventive concept as the foregoing embodiments, this embodiment also provides a machine-readable storage medium storing a computer program. The machine-readable storage medium can be a magnetic random access memory (FRAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM), etc.; it can also be various devices including one or any combination of the above-mentioned memories, such as mobile phones, computers, tablet devices, personal digital assistants, etc. When the computer program stored in the machine-readable storage medium is executed by a processor, it implements a control method for an automotive battery management system applied to the aforementioned vehicle. For the specific steps implemented when the computer program is executed by the processor, please refer to [link to relevant documentation]. Figure 1 The description of the illustrated embodiments will not be repeated here.

[0073] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0074] In this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0075] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A control method for an automotive battery management system, characterized in that, include: The bus current is collected by the analog front-end set inside the battery management system through the shunt at a sampling period not higher than the preset first sampling period threshold. The bus current is then subjected to fast Fourier transform by the digital signal processor to calculate the ripple amplitude and ripple frequency. The sampling path of the analog front-end is independent of the controller local area network bus and does not interfere with the original functions of the independent current sensor for state of charge estimation and functional safety monitoring. If the ripple amplitude and the ripple frequency meet the preset mode determination conditions, then it is determined that the strong ripple interference mode is entered. In response to entering the strong ripple interference mode, the consistency fault threshold of the independent current sensor is dynamically increased from the basic threshold to obtain a dynamic protection threshold, wherein the dynamic protection threshold is equal to the basic threshold plus the product of a coefficient and the ripple amplitude, the coefficient is a preset coefficient and the value range is a preset coefficient interval, and the fault recovery counter is extended from a preset first recovery count threshold to a preset second recovery count threshold. At the same time, the fault threshold of the main and auxiliary link voltage difference of voltage sampling is increased from a preset basic voltage difference threshold to a preset voltage difference interval, and software filtering with a window of integer multiple of the ripple period is initiated for the current and voltage sampling values. When the ripple amplitude is less than a preset second current threshold and the ripple frequency is less than a preset second frequency threshold and continues to exceed a preset first duration threshold, the strong ripple interference mode is exited, and the consistency fault threshold and the voltage difference fault threshold are gradually restored to their original values ​​to return to normal functional safety diagnostic logic.

2. The method according to claim 1, characterized in that, The method involves acquiring the bus current via a shunt through an analog front-end set within the battery management system at a sampling period not exceeding a preset first sampling period threshold, and then using a digital signal processor to perform a fast Fourier transform on the bus current to calculate the ripple amplitude and ripple frequency, including: The bus current is collected through the shunt channel of the analog front end at a sampling period not higher than the preset first sampling period threshold. The ripple amplitude and ripple frequency are obtained by separating and calculating the bus current using the digital signal processor via Fast Fourier Transform.

3. The method according to claim 1, characterized in that, If the ripple amplitude and the ripple frequency meet a preset mode determination condition, then it is determined that the system enters a strong ripple interference mode, including at least one of the following: When the ripple frequency is not less than a preset first frequency threshold and the ripple amplitude is not less than a preset first current threshold, it is determined that the strong ripple interference mode is entered. When the difference between any two range channels inside the independent current sensor fluctuates periodically, and the frequency difference between the fluctuation frequency and the operating frequency of the electric drive is less than a preset frequency deviation threshold, it is determined that the strong ripple interference mode is entered.

4. The method according to claim 1, characterized in that, The method of dynamically adjusting the consistency fault threshold of independent current sensors from a base threshold to obtain a dynamic protection threshold includes: The basic threshold is taken as the basic determination threshold of the difference between the high-medium channel or the high-low channel of the independent current sensor, and its value is a preset basic determination threshold. The dynamic protection threshold is dynamically calculated according to the formula based on the ripple amplitude and coefficient.

5. The method according to claim 1, characterized in that, The step of adjusting the fault threshold for the voltage difference between the primary and secondary links in voltage sampling from a preset basic voltage difference threshold to a preset voltage difference range includes: The voltage difference fault threshold is calibrated based on the cell polarization voltage fluctuation under ripple, and the voltage difference fault threshold is adjusted from the preset basic voltage difference threshold to the preset voltage difference range.

6. The method according to claim 1, characterized in that, The software filtering that initiates the current and voltage sampling values ​​within an integer multiple of the ripple period includes: The current sample value and the voltage sample value are subjected to median filtering or moving average filtering, wherein the filtering window is an integer multiple of the ripple period and the value range is from a preset first window period number to a preset second window period number.

7. The method according to claim 1, characterized in that, The dynamic adjustment of the consistency fault threshold and the dynamic adjustment of the voltage difference fault threshold are performed synchronously based on the ripple amplitude and the ripple frequency, so as to simultaneously avoid the consistency false alarm of the independent current sensor and the cell voltage acquisition fault false alarm of the voltage sampling.

8. A control device for an automotive battery management system, characterized in that, include: The sampling and calculation module is used to collect the bus current through the analog front end set inside the battery management system via the shunt at a sampling period not higher than the preset first sampling period threshold, and to use the digital signal processor to perform a fast Fourier transform on the bus current to calculate the ripple amplitude and ripple frequency. The sampling path of the analog front end is independent of the controller local area network bus and does not interfere with the original functions of the independent current sensor for state of charge estimation and functional safety monitoring. The mode determination module is used to determine that if the ripple amplitude and the ripple frequency meet the preset mode determination conditions, then the strong ripple interference mode is entered. The anti-ripple protection module is used to respond to entering the strong ripple interference mode by dynamically increasing the consistency fault threshold of the independent current sensor from the basic threshold to obtain a dynamic protection threshold, wherein the dynamic protection threshold is equal to the basic threshold plus the product of a coefficient and the ripple amplitude, the coefficient being a preset coefficient and the value range being a preset coefficient interval, and extending the fault recovery counter from a preset first recovery count threshold to a preset second recovery count threshold, while increasing the fault threshold of the main and auxiliary link voltage difference of voltage sampling from a preset basic voltage difference threshold to a preset voltage difference interval, and initiating software filtering of the current and voltage sampling values ​​with a window that is an integer multiple of the ripple period; The exit recovery module is used to exit the strong ripple interference mode when the ripple amplitude is less than the preset second current threshold and the ripple frequency is less than the preset second frequency threshold and continues to exceed the preset first duration threshold, and gradually restores the consistency fault threshold and the voltage difference fault threshold to their original values ​​to return to normal functional safety diagnostic logic.

9. A vehicle, characterized in that, include: A processor and a memory for storing executable instructions; wherein the processor is configured to execute the instructions to implement the automotive battery management system control method as described in any one of claims 1-7.

10. A machine-readable storage medium, characterized in that, When the instructions in the machine-readable storage medium are executed by the processor, the vehicle battery management system control method as described in any one of claims 1-7 is implemented.

Images