Hybrid vehicle battery low charge warning method, device and system

Abstract

This application provides a method, device, and system for low battery warning in hybrid electric vehicles. The method includes: outputting a specified textual reminder message when the battery charge is detected to be less than a first preset threshold; entering a rapid diagnostic window for a specified time period when the battery charge is detected to be less than a second preset threshold, performing multi-dimensional dynamic verification in conjunction with the engine status sent by the engine management system (EMS), and activating a safety-related power-loss warning after successful verification; performing a collaborative diagnostic process with the EMS when the battery charge is detected to be less than a third preset threshold; and controlling the battery according to a preset power limiting strategy when the battery charge is detected to be less than a fourth preset threshold; wherein the first, second, third, and fourth preset thresholds decrease sequentially. This application, by optimizing the warning thresholds and response strategies, can reduce the risk of safety-related power-loss and improve the user's driving experience.

Description

Technical Field

[0001] This application relates to the field of energy management technology for hybrid electric vehicles, and in particular to a method, device, and system for early warning of low battery power in hybrid electric vehicles. Background Technology

[0002] As the global automotive industry transitions to electrification, hybrid electric vehicles (HEVs) have become a crucial technological option in this transitional phase. Combining the advantages of traditional internal combustion engines (ICE) and electric power, they offer power output and electricity generation through an engine, while also utilizing batteries as an auxiliary power source, making them widely popular in the market. However, HEV models have also revealed some technical shortcomings in practical use, particularly regarding the need for optimization in energy management strategies.

[0003] The core of energy management in HEV models lies in coordinating the working states of the engine and the power battery. In actual operation, if the engine malfunctions or the control strategy is flawed (such as severely delayed warning response or unreasonable threshold settings), it may prevent the power battery from charging properly. This will cause the battery to continuously deplete, leading to a risk of unsafe parking (or even abandonment). The aftermarket has already received numerous complaints from users regarding this issue, primarily concerning sudden power outages and inability to drive normally. Summary of the Invention

[0004] The purpose of this application is to provide a method, device, and system for low battery warning of hybrid electric vehicles. By optimizing the warning threshold and response strategy, the risk of battery failure can be reduced and the user's driving experience can be improved.

[0005] In a first aspect, this application provides a low battery warning method for hybrid electric vehicles. The method includes: when the battery charge is detected to be less than a first preset threshold, outputting a specified textual reminder message; when the battery charge is detected to be less than a second preset threshold, entering a specified time period quick diagnostic window, performing multi-dimensional dynamic verification in conjunction with the engine status sent by the engine management system (EMS), and activating a safety warning after successful verification; when the battery charge is detected to be less than a third preset threshold, performing a collaborative diagnostic process with the EMS; and when the battery charge is detected to be less than a fourth preset threshold, controlling the battery according to a preset power limiting strategy; wherein the first, second, third, and fourth preset thresholds decrease sequentially.

[0006] Furthermore, the aforementioned designated classical Chinese reminder message includes: "Battery power is low, please drive gently."

[0007] Furthermore, the aforementioned rapid diagnostic window for a specified time period, combined with the engine status sent by the Engine Management System (EMS), performs multi-dimensional dynamic verification. After successful verification, the step of activating the safety-disposal warning includes: collecting SOC and total battery voltage at preset intervals, and reading the engine status sent by the EMS via the CAN bus; the engine status includes: engine speed and power generation; based on the periodically collected SOC and total battery voltage, calculating the SOC change rate and the battery total voltage drop slope; determining whether the following conditions are met within a continuous specified time period: the SOC change rate is continuously higher than a preset change rate threshold, and the battery total voltage drop slope exceeds a preset slope threshold, and the engine speed is 0 or the power generation is 0; if so, it is determined to be a true emergency state, and the safety-disposal warning is immediately activated; if not, the rapid diagnostic window is extended, and monitoring continues until the conditions are met or the power battery charge is less than a third preset threshold.

[0008] Furthermore, the steps of performing the collaborative diagnostic process with the EMS include: sending a power generation capacity request to the EMS so that the EMS can calculate the maximum sustainable power generation based on the current engine operating parameters according to the power generation capacity request; the current engine operating parameters include: water temperature, speed, torque, and fault codes; receiving the maximum sustainable power generation returned by the EMS, and marking power generation as unavailable if the maximum sustainable power generation is less than the required power, or if a level 5 fault warning message is received from the EMS; if the fuel level signal is detected to be zero at the same time, immediately performing a high-pressure operation; if power generation is unavailable and the fuel level is not zero, entering a degraded mode: limiting the discharge power to a specified value and displaying a specified warning message.

[0009] Furthermore, the steps of controlling according to the preset power limiting strategy include: calculating the maximum discharge power based on the current power battery charge; sending the maximum discharge power to the vehicle controller (VCU) and EMS so that the VCU coordinates the motor torque to ensure that the battery discharge power does not exceed the maximum discharge power, and the EMS simultaneously adjusts the engine output so that the total power does not exceed the maximum discharge power; if the battery voltage or temperature exceeds the safe range, the maximum discharge power is directly forced to be set to 0.

[0010] Furthermore, the steps for calculating the maximum discharge power based on the current power battery charge include: obtaining the difference between the current power battery charge and 25%; calculating the quotient of the difference and 5% to obtain the power limitation coefficient; and calculating the product of the power limitation coefficient and the rated power to obtain the maximum discharge power.

[0011] Furthermore, the above method also includes: when the power battery charge is detected to be less than a fifth preset threshold, executing a three-level fault lock package.

[0012] Furthermore, the first preset threshold, the second preset threshold, the third preset threshold, the fourth preset threshold, and the fifth preset threshold are respectively 34%, 33%, 32%, 30%, and 25%.

[0013] Secondly, this application also provides a low battery warning device for hybrid electric vehicles. The device includes: a reminder module, used to output a specified text reminder message when the battery charge is detected to be less than a first preset threshold; a warning module, used to enter a specified time period quick diagnosis window when the battery charge is detected to be less than a second preset threshold, and perform multi-dimensional dynamic verification in conjunction with the engine status sent by the engine management system (EMS), and activate a safety warning after successful verification; a diagnosis module, used to perform a collaborative diagnosis process with the EMS when the battery charge is detected to be less than a third preset threshold; and a control module, used to control the battery according to a preset power limiting strategy when the battery charge is detected to be less than a fourth preset threshold; wherein the first preset threshold, the second preset threshold, the third preset threshold, and the fourth preset threshold decrease sequentially.

[0014] Thirdly, this application also provides a low battery warning system for hybrid electric vehicles, the system comprising: a BMS and an EMS; the BMS and the EMS are communicatively connected; the BMS is used to perform the method described in the first aspect.

[0015] The hybrid electric vehicle battery low-charge warning method, device, and system provided in this application output a specified textual reminder message when the battery charge is detected to be less than a first preset threshold; when the battery charge is detected to be less than a second preset threshold, a rapid diagnostic window for a specified time period is entered, and multi-dimensional dynamic verification is performed in conjunction with the engine status sent by the engine management system (EMS). After successful verification, a safety disposal warning is activated; when the battery charge is detected to be less than a third preset threshold, a collaborative diagnostic process with the EMS is executed; when the battery charge is detected to be less than a fourth preset threshold, control is performed according to a preset power limiting strategy; wherein, the first, second, third, and fourth preset thresholds decrease sequentially. This application, for the power battery charge management of HEV models, effectively prevents the risk of vehicle safety disposal due to battery depletion by optimizing warning thresholds and response strategies. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the specific embodiments of this application or 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 this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 A flowchart illustrating a low battery warning method for a hybrid electric vehicle provided in this application embodiment; Figure 2 A flowchart illustrating another low battery warning method for hybrid electric vehicles provided in this application embodiment; Figure 3 A structural block diagram of a low battery warning device for a hybrid electric vehicle provided in this application embodiment; Figure 4 This is a structural block diagram of a low battery warning system for a hybrid electric vehicle provided in an embodiment of this application. Detailed Implementation

[0018] The technical solutions of this application will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] The main drawbacks of existing low battery warning strategies for HEVs (Hybrid-Electric Vehicles) are as follows: 1. The early warning response is severely delayed. The original strategy employed a 60-second delay mechanism for emergency battery discharge warnings, which has proven to pose significant safety risks in practice. When battery power rapidly declines, the battery's state of charge (SOC) may drop by 3-5 percentage points during the 60-second delay, causing the system to miss its optimal protection window. Especially in emergency situations where the engine fails and charging is impossible, this delay could directly lead to battery depletion.

[0020] 2. The threshold setting is unreasonable. The original strategy's threshold settings have several flaws: the power limit threshold (32%) is set too high, causing vehicle performance to be limited prematurely and affecting normal driving; the low battery warning threshold (30%) is set too low, often leaving users with insufficient time to take effective measures when they receive the warning. The design of the threshold intervals at each level lacks scientific rigor, and the protection gradient is unclear.

[0021] 3. Poor user prompts The "Power Battery Low Charge Warning" is vaguely worded and fails to effectively guide users to take the correct measures. When users see this warning, they are unclear about what specific actions they should take to improve the situation, thus greatly reducing the actual effectiveness of the warning.

[0022] 4. Insufficient system coordination The original strategy primarily relied on the BMS (Battery Management System) for fault diagnosis, lacking integration with the EMS (Engine Management System). Management Deep collaboration with the Engine Management System (BMS). When the engine system malfunctions, the BMS cannot obtain relevant information in a timely manner, resulting in delayed protective measures.

[0023] 5. Overly concentrated protective measures The process from the initial warning to the BMS locking of the package is relatively concentrated and lacks a smooth transition. Users may receive multiple strong warning messages in a short period of time, which can easily cause confusion and panic.

[0024] 6. Lack of foresight protection The original strategy relies entirely on the current SOC (State of Charge, also known as battery charge) value, lacking predictive analysis of charge change trends and failing to take preventative measures before a sharp drop in charge.

[0025] Based on this, embodiments of this application provide a method, apparatus, and system for warning of low battery power in hybrid electric vehicles. By optimizing the warning threshold and response strategy, the risk of battery failure can be reduced and the user's driving experience can be improved.

[0026] To facilitate understanding of this embodiment, a low battery warning method for hybrid electric vehicles disclosed in this application will first be described in detail. This application provides a low battery warning method for hybrid electric vehicles. (See also...) Figure 1 As shown, the method specifically includes the following steps: Step S102: When the power battery charge is detected to be less than the first preset threshold, output a specified text reminder message; In this embodiment, the first preset threshold is 34%. The specified textual reminder message includes: "Low battery power, please drive gently." If only the message "Power battery low" is displayed, the wording is rather vague, and the user will not know what specific action to take to improve the situation, thus greatly reducing the actual effectiveness of the reminder. In this embodiment, when the power battery power is detected to be lower than the first preset threshold, the message "Low battery power, please drive gently" is directly displayed, which can guide the user's actual operation and improve the user's driving experience.

[0027] In practical applications, when the current power battery charge is less than 34%, the instrument panel will display a text reminder: "Power battery charge is low, please drive gently." An audible reminder may also be provided, which will turn off after a certain period.

[0028] Step S104: When the power battery charge is detected to be less than the second preset threshold, enter the quick diagnosis window for a specified time period, and perform multi-dimensional dynamic verification in combination with the engine status sent by the engine management system EMS. After the verification is passed, activate the safety and safety warning. The second preset threshold is 33%, and the specified time period rapid diagnosis window is a 3-second rapid diagnosis window. During this window period, the engine status sent by the engine management system (EMS) is dynamically verified in multiple dimensions. After the verification is passed, the safety and maintenance warning is issued. This method can effectively filter out false triggers caused by sensor noise or instantaneous fluctuations through multi-parameter cross-verification while ensuring rapid response.

[0029] In practical applications, the dynamic verification process in collaboration with EMS can be continuously executed when the battery level is between 33% and 32%. The same applies to subsequent steps; the corresponding operations will continue to be performed within the range between the current threshold and the next threshold.

[0030] Step S106: When the power battery charge is detected to be less than the third preset threshold, a collaborative diagnostic process with EMS is executed. The aforementioned third preset threshold is 32%. If fault diagnosis is performed solely through the BMS without deep collaboration with the EMS, the BMS cannot obtain relevant information in a timely manner when a fault occurs in the engine system, resulting in delayed protection measures. Therefore, this embodiment employs a collaborative diagnostic process with the EMS, the specific implementation of which will be detailed later.

[0031] Step S108: When the power battery charge is detected to be less than the fourth preset threshold, control is performed according to the preset power limiting strategy; wherein the first preset threshold, the second preset threshold, the third preset threshold and the fourth preset threshold decrease sequentially.

[0032] The fourth preset threshold mentioned above is 30%. This preset power limiting strategy includes a coordinated power limiting process with the EMS. The specific implementation method will be detailed later.

[0033] The low battery warning method for hybrid electric vehicles provided in this application optimizes the warning threshold and response strategy, significantly reducing the safety breakage warning response time from 60 seconds to 3 seconds, advancing the warning threshold from 30% to 34%, improving the user prompt message to a clear and instructive "low battery power, please drive gently", and enhancing the collaborative protection between the battery management system and the engine management system. This effectively prevents battery depletion, significantly reduces the risk of vehicle breakdown, and improves system safety and user experience.

[0034] This application also provides another method for low battery warning of hybrid electric vehicles, which is implemented based on the above embodiments. This embodiment focuses on describing the specific implementation process of each step described above. See Figure 2 As shown, the low battery warning method for hybrid electric vehicles specifically includes the following steps: 1. When the SOC is greater than 50%, the engine will shut down.

[0035] 2. When the SOC is less than 45%, the engine starts. If it is in the ON position and not ready, the vehicle disconnects the high voltage. That is, when the battery charge (SOC) drops to 45%, the car engine should start generating electricity; however, since the car is only in the ON position and not yet ready to drive, the vehicle will disconnect the high voltage.

[0036] 3. When the SOC is less than 34%, the system will display the message "Low battery power, please drive gently".

[0037] 4. When SOC is less than 33%, the system enters a 3-second quick diagnostic window: The system collects SOC and total battery voltage at preset intervals and reads the engine status sent by EMS via the CAN bus. The engine status includes engine speed and power generation. Based on the periodically collected SOC and total battery voltage, the system calculates the SOC change rate and the battery total voltage drop slope. It then determines whether the following conditions are met within a continuously specified time period: the SOC change rate is continuously higher than the preset change rate threshold, the battery total voltage drop slope exceeds the preset slope threshold, and the engine speed is 0 or the power generation is 0. If so, it is determined to be a real emergency state, and the safety-discharge warning is immediately activated. Otherwise, the rapid diagnosis window is extended, and monitoring continues until the conditions are met or the power battery charge is less than the third preset threshold.

[0038] In practice, it is achieved through the following steps: a) The BMS collects SOC, total voltage, and minimum individual voltage at a 100ms cycle; b) Calculate the SOC change rate dSOC / dt and compare it with the preset threshold (0.5% / s); c) Read the engine status sent by EMS via CAN bus: including engine speed (EngineSpeed), target power generation (GenPwrReq), actual power generation (GenPwrAct), fault codes (DTC) and fault level. d) If dSOC / dt remains above the threshold for 2 consecutive seconds and the slope of the total battery voltage drop exceeds 0.5V / s, while the EMS feedback indicates that the engine speed is 0 or the power generation is 0, then a true emergency situation is determined, and the battery emergency warning is immediately activated (instrument display + constant alarm sound). e) If all conditions are not met within 3 seconds, the warning window will be extended, and monitoring will continue until the conditions are met or the SOC further decreases to 32%; f) If the SOC rises above 34% during the window period, the warning window will be closed and normal alerts will be restored.

[0039] 5. When SOC is less than 32%, perform a collaborative diagnostic process with EMS: Send a power generation capacity request to the EMS so that the EMS can calculate the maximum sustainable power generation based on the current engine operating parameters, including water temperature, speed, torque, and fault codes. Receive the maximum sustainable power generation returned by the EMS. If the maximum sustainable power generation is less than the required power, or if the EMS returns a level 5 fault warning, mark power generation as unavailable. If a zero fuel level signal is detected simultaneously, immediately perform a high-pressure reduction operation. If power generation is unavailable and the fuel level is not zero, enter degrade mode: limit the discharge power to a specified value and display a specified warning message.

[0040] In practice, it is achieved through the following steps: a) BMS sends a "GenCapability Request" to EMS. b) The EMS calculates the maximum sustainable power generation P_max_gen based on the current engine operating parameters (water temperature, speed, torque, fault code). If P_max_gen < demand power (5kW) or the EMS has a level 5 fault, then it is marked as "Power generation unavailable". c) If the oil quantity signal is detected to be zero at the same time, immediately execute the high-pressure operation; d) If generator power is unavailable but fuel level is not zero, the system enters degrade mode: limiting discharge power to 10kW and displaying the message "Engine generator power generation abnormal, please repair in time".

[0041] 6. When the SOC is less than 30%, control will be performed according to the preset power limiting strategy: Based on the current battery charge, the maximum discharge power is calculated (by taking the difference between the current battery charge and 25%, dividing the difference by 5% to obtain the power limit factor; and multiplying the power limit factor by the rated power to obtain the maximum discharge power). The maximum discharge power is then sent to the VCU (Vehicle Control Unit) and EMS, so that the VCU coordinates the motor torque to ensure the battery discharge power does not exceed the maximum discharge power, and the EMS simultaneously adjusts the engine output to ensure the total power does not exceed the maximum discharge power. If the battery voltage or temperature exceeds the safe range, the maximum discharge power is directly forced to be set to 0. In practice, this is achieved through the following steps: a) The BMS calculates the power limiting factor K = (SOC - 25%) / (30% - 25%), and limits the maximum discharge power P_max = K * P_rated. When SOC = 25%, K = 0. b) Send P_max to VCU and EMS via CAN; c) The VCU coordinates the motor torque to ensure that the battery discharge power does not exceed P_max; if the EMS has its own power generation capacity, the motor output is adjusted at the same time to ensure that the total power does not exceed P_max. d) If the battery voltage or temperature exceeds the safe range, then directly force P_max=0kW.

[0042] 7. When SOC is less than 25% (i.e., the fifth preset threshold), the BMS will lock the package for a level 3 fault.

[0043] As described in the above embodiments, the HEV battery low-charge warning and protection strategy establishes a complete protection system based on a seven-level SOC threshold, achieving full-process monitoring from warning to protection through systematic optimization. The core of this technical solution lies in three dimensions: reconstructing the threshold sequence, optimizing the response mechanism, and enhancing system coordination.

[0044] The multi-level threshold protection system redesigns the SOC threshold sequence to form a seven-level protection strategy: The first level is set when the SOC is greater than 50%, allowing the engine to shut down to optimize fuel economy; The second stage automatically starts the engine to charge when the SOC is less than 45%; The third level provides an early warning when the SOC is less than 34%; Level 4 immediately initiates an ampoule warning when the SOC is less than 33%, but the triggering of this warning no longer simply depends on a delay, but introduces dynamic condition judgment; Level 5 introduces EMS system fault diagnosis when SOC is less than 32%; Level 6 applies power limiting when the SOC is less than 30%; Level 7 activates the final protection mechanism when the SOC is less than 25%.

[0045] This gradient design ensures the gradual and continuous nature of the protective measures.

[0046] In this embodiment, the optimized implementation of the response mechanism is as follows: ① The text message prompting "Power battery low" has been changed to "Power battery power is low, please drive gently." The trigger threshold has been adjusted from 30% to 34%.

[0047] ②Actively reduce high voltage conditions to include EMS level 5 faults and real-time assessment of engine power generation capacity.

[0048] ③ Battery output power is limited to 0, and the threshold is adjusted from 32% to <30%.

[0049] ④ The response time for the battery pack emergency malfunction warning has been reduced from 60 seconds to 3 seconds. However, to avoid false alarms, a multi-dimensional dynamic verification mechanism has been introduced: When the State of Charge (SOC) drops to 33%, the system does not immediately trigger the emergency malfunction warning. Instead, it initiates a rapid diagnostic window that lasts for 3 seconds. Within this window, the BMS continuously monitors the SOC change rate (dSOC / dt), the total battery pack voltage, the lowest voltage of each individual cell, and the engine status (speed, power generation, fault codes) fed back by the EMS. If, within 3 seconds, the SOC decrease rate continues to exceed the preset threshold (0.5% / s), and the battery voltage shows a sudden drop, while the EMS reports that the engine cannot generate electricity (speed is 0 or power generation is 0), the system confirms a true emergency state and immediately activates the emergency malfunction warning (instrument display + alarm sound). If the above conditions are not met within 3 seconds, the warning delay accumulates until the conditions are met or the SOC further deteriorates. This mechanism, while ensuring rapid response, effectively filters out false triggers caused by sensor noise or instantaneous fluctuations through multi-parameter cross-verification.

[0050] The implementation method of system collaborative protection is as follows: The collaboration between the BMS and EMS systems is a key feature of the improvement strategy. During implementation, a Level 5 fault diagnosis in the EMS is introduced as one of the trigger conditions for reducing high voltage when the State of Charge (SOC) reaches 32%. This improvement is achieved by establishing a cross-system information sharing mechanism, with the BMS and EMS systems exchanging status information in real time via a dedicated communication link.

[0051] Building upon this foundation, collaborative control has been further deepened: 1. Dynamic Power Generation Capacity Assessment: When the State of Charge (SOC) is between 34% and 32%, the BMS periodically sends a "Power Generation Capacity Request" signal to the EMS. The EMS calculates and returns the maximum sustainable power generation capacity in real time based on the current engine operating conditions (water temperature, speed, torque, and presence of faults). If the return value is 0 or significantly lower than the required value, the system marks the EMS as having "insufficient power generation capacity" in advance. This status will serve as an auxiliary judgment condition for subsequent high-voltage adjustments.

[0052] 2. Fault Information Classification and Fusion: In addition to the five-level fault labels of EMS, BMS also receives fault levels and fault types ("generator drive fault", "engine shutdown fault") sent by EMS. BMS establishes a fault impact model internally and dynamically adjusts the protection strategy according to the fault type: for example, if EMS reports "generator overheating" but does not shut down, the system may first limit the discharge power instead of directly reducing the high voltage.

[0053] 3. Coordinated Power Reduction Strategy: When the State of Charge (SOC) drops to 30%, the Battery Management System (BMS) implements power limiting and simultaneously sends the target power limit to the Electronic Power System (EMS). The EMS adjusts the engine output according to its own capabilities. If the engine also cannot provide sufficient power, the EMS and BMS jointly request the Vehicle Control Unit (VCU) to limit the motor torque, achieving coordinated power reduction at the powertrain level and avoiding overload of a single system. When the system detects that the State of Charge (SOC) has dropped to 32%, it first initiates the EMS system self-diagnostic program to assess the engine's power generation capacity. If an EMS level 5 fault is detected simultaneously and the fuel level signal is zero, or if the power generation capacity assessment confirms that power generation is impossible, the system will execute a high-pressure reduction operation. This dual-judgment mechanism significantly improves system reliability and avoids protection failures caused by a single system fault.

[0054] The power management strategy is implemented as follows: The power limiting strategy has undergone a significant adjustment, delaying the power limiting threshold from 32% to 30%. In implementation, the system employs a phased power limiting approach: when the State of Charge (SOC) is between 34% and 30%, the system primarily guides users to adopt gentle driving techniques through warnings to maintain normal vehicle power performance; only when the SOC drops below 30% is strict zero-power limiting implemented. During this phase, the system uses a progressive power limiting algorithm: linearly reducing the maximum allowable discharge power based on the degree to which the SOC deviates from 30%, while monitoring battery voltage and temperature in real time. If any abnormalities are detected, the system prematurely enters zero-power mode. Simultaneously, the power limiting command is sent to the EMS and VCU, with the VCU coordinating the torque output of the motor and engine to ensure the vehicle maintains its driving capability as much as possible while ensuring safety.

[0055] The user interaction system is implemented as follows: The user prompt system has been fully optimized. When the SOC reaches 34%, the system will display a message saying "Low battery power, please drive gently." This improvement is achieved by refactoring the content and timing of the prompt, moving the low battery warning that was previously displayed at 30% to 34%, and using more instructive language.

[0056] The fault handling mechanism is implemented as follows: The system's protection mechanism forms a complete protection chain. Starting with an initial warning at 34% SOC and ending with final protection at 25%, the system establishes interconnected protection measures. In practice, each protection level has corresponding entry and exit conditions to ensure that protection measures can be flexibly adjusted according to actual conditions. Furthermore, the system adds a "state retention" mechanism: if a warning or protection is triggered due to dynamic conditions, but the SOC subsequently recovers (engine successfully starts charging), the system will automatically clear the corresponding protection level's state and restore normal alerts, avoiding erroneous packet locking caused by brief fluctuations.

[0057] The system also establishes a fault emergency handling mechanism, which can trigger corresponding protection measures in advance when abnormal engine power generation or system communication failure is detected. This dynamic protection strategy based on risk assessment ensures that the system can provide effective protection under various abnormal conditions.

[0058] The low battery warning method for hybrid electric vehicles provided in this application mainly addresses the technical problem of the risk of vehicle abandonment due to continuous consumption of power battery charge when the engine fails or the energy management strategy fails. Specifically, it optimizes the battery charge warning protection strategy by constructing a seven-level SOC threshold protection system. This significantly reduces the abandonment warning response time from 60 seconds to 3 seconds, advances the warning threshold from 30% to 34%, and reasonably adjusts the power limit threshold from 32% to 30%. The user prompt message is improved to be a clear and instructive "Power battery charge is low, please drive gently." Furthermore, it introduces an EMS system collaborative diagnostic mechanism to enhance the collaborative protection between the battery management system and the engine management system. This forms a progressive warning protection system that is more timely in response, more accurate in protection, and more closely coordinated, effectively preventing battery depletion, significantly reducing the risk of vehicle abandonment, and effectively improving system safety and user experience.

[0059] Based on the above method embodiments, this application also provides a low battery warning device for hybrid electric vehicles, see [link to relevant documentation]. Figure 3 As shown, the device includes: a reminder module 32, used to output a specified text reminder message when the power battery charge is detected to be less than a first preset threshold; a warning module 34, used to enter a specified time period quick diagnosis window when the power battery charge is detected to be less than a second preset threshold, and perform multi-dimensional dynamic verification in conjunction with the engine status sent by the engine management system (EMS), and activate an anti-discharge warning after the verification is passed; a diagnosis module 36, used to perform a collaborative diagnosis process with the EMS when the power battery charge is detected to be less than a third preset threshold; and a control module 38, used to control the power battery according to a preset power limiting strategy when the power battery charge is detected to be less than a fourth preset threshold; wherein the first preset threshold, the second preset threshold, the third preset threshold, and the fourth preset threshold decrease sequentially.

[0060] Furthermore, the aforementioned designated classical Chinese reminder message includes: "Battery power is low, please drive gently."

[0061] Furthermore, the aforementioned early warning module 34 is used to collect SOC and total battery voltage at preset intervals, and read the engine status sent by EMS via the CAN bus; the engine status includes: engine speed and power generation; based on the periodically collected SOC and total battery voltage, calculate the SOC change rate and the battery total voltage drop slope; determine whether the following conditions are met within a continuously specified time period: the SOC change rate is continuously higher than the preset change rate threshold, and the battery total voltage drop slope exceeds the preset slope threshold, and the engine speed is 0 or the power generation is 0; if so, it is determined to be a real emergency state, and the safety-discharge early warning is immediately activated; if not, the rapid diagnosis window is extended, and monitoring continues until the conditions are met or the power battery charge is less than the third preset threshold.

[0062] Furthermore, the aforementioned diagnostic module 36 is used to send a power generation capacity request to the EMS, so that the EMS can calculate the maximum sustainable power generation based on the current engine operating parameters according to the power generation capacity request; the current engine operating parameters include: water temperature, speed, torque, and fault codes; receiving the maximum sustainable power generation returned by the EMS, and marking power generation as unavailable if the maximum sustainable power generation is less than the required power, or if a level 5 fault prompt message is received from the EMS; if the fuel level signal is detected to be zero at the same time, a high-pressure operation is immediately performed; if power generation is unavailable and the fuel level is not zero, a degraded mode is entered: the discharge power is limited to a specified value, and a specified prompt message is displayed.

[0063] Furthermore, the aforementioned control module 38 is used to calculate the maximum discharge power based on the current power battery charge; send the maximum discharge power to the vehicle controller (VCU) and EMS so that the VCU coordinates the motor torque to ensure that the battery discharge power does not exceed the maximum discharge power, and simultaneously adjusts the engine output of the EMS so that the total power does not exceed the maximum discharge power; if the battery voltage or temperature exceeds the safe range, the maximum discharge power is directly forced to be set to 0.

[0064] Furthermore, the aforementioned control module 38 is used to calculate the difference between the current power battery charge and 25%, calculate the quotient of the difference and 5% to obtain the power limitation coefficient, and calculate the product of the power limitation coefficient and the rated power to obtain the maximum discharge power.

[0065] Furthermore, the aforementioned device also includes a lock module, used to execute a three-level fault lock when the power battery charge is detected to be less than a fifth preset threshold.

[0066] Furthermore, the first preset threshold, the second preset threshold, the third preset threshold, the fourth preset threshold, and the fifth preset threshold are respectively 34%, 33%, 32%, 30%, and 25%.

[0067] The device provided in this application embodiment has the same implementation principle and technical effect as the aforementioned method embodiment. For the sake of brevity, any parts of the device embodiment not mentioned can be referred to the corresponding content in the aforementioned method embodiment.

[0068] Based on the above method embodiments, this application also provides a low battery warning system for hybrid electric vehicles, see [link to relevant documentation]. Figure 4 As shown, the system includes: a BMS and an EMS; the BMS is connected to the EMS in communication; the BMS is used to perform the methods described in the foregoing method embodiments.

[0069] The system provided in this application embodiment has the same implementation principle and technical effects as the aforementioned method embodiment. For the sake of brevity, any parts not mentioned in the system embodiment can be referred to the corresponding content in the aforementioned method embodiment.

[0070] This application also provides a computer-readable storage medium storing computer-executable instructions. When the computer-executable instructions are called and executed by a processor, the computer-executable instructions cause the processor to implement the above-described method. For specific implementation details, please refer to the foregoing method embodiments, which will not be repeated here.

[0071] The computer program products of the methods, apparatus, and electronic devices provided in the embodiments of this application include a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods described in the preceding method embodiments. For specific implementations, please refer to the method embodiments, which will not be repeated here.

[0072] Unless otherwise specifically stated, the relative steps, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application.

[0073] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0074] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0075] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A method for early warning of low battery power in a hybrid electric vehicle, characterized in that, The method includes: When the power battery charge is detected to be less than the first preset threshold, a specified text-based reminder message is output. When the power battery charge is detected to be less than the second preset threshold, a quick diagnosis window for a specified time period is entered. Multi-dimensional dynamic verification is performed in combination with the engine status sent by the engine management system EMS. After the verification is passed, the safety and power loss warning is activated. When the power battery charge is detected to be less than a third preset threshold, a collaborative diagnostic process with the EMS is executed. When the power battery charge is detected to be less than the fourth preset threshold, control is performed according to a preset power limiting strategy; wherein the first preset threshold, the second preset threshold, the third preset threshold and the fourth preset threshold decrease sequentially.

2. The method according to claim 1, characterized in that, The specified classical Chinese reminder message includes: "Low battery power, please drive gently." 3. The method according to claim 1, characterized in that, Enter the rapid diagnostic window for the specified time period, and perform multi-dimensional dynamic verification based on the engine status sent by the Engine Management System (EMS). After successful verification, the steps to activate the safety jettison warning include: The system charge (SOC) and total battery voltage are collected at preset intervals, and the engine status sent by the EMS is read via the CAN bus; the engine status includes: engine speed and power generation. Based on the SOC and total battery voltage collected periodically, calculate the rate of change of SOC and the slope of the decrease in total battery voltage. Determine whether the following conditions are met within a continuously specified time period: the SOC change rate is continuously higher than a preset change rate threshold, the slope of the total battery voltage drop exceeds a preset slope threshold, and the engine speed is 0 or the power generation is 0. If so, it is determined to be a genuine emergency, and the emergency warning is activated immediately; If not, extend the rapid diagnostic window and continue monitoring until the conditions are met or the power battery charge is less than the third preset threshold.

4. The method according to claim 1, characterized in that, The steps for performing a collaborative diagnostic process with the EMS include: A power generation capacity request is sent to the EMS, so that the EMS can calculate the maximum sustainable power generation based on the current engine operating parameters according to the power generation capacity request; the current engine operating parameters include: water temperature, speed, torque, and fault codes; If the maximum sustainable power generation is received from the EMS and it is determined that the maximum sustainable power generation is less than the required power, or if a level 5 fault warning message is received from the EMS, power generation is marked as unavailable; if the oil level signal is detected to be zero at the same time, a high-pressure operation is immediately performed. If power generation is unavailable and the fuel level is not zero, the system enters degrade mode: limiting the discharge power to a specified value and displaying a specified prompt message.

5. The method according to claim 1, characterized in that, The steps for controlling according to the preset power limiting strategy include: Calculate the maximum discharge power based on the current battery charge level; The maximum discharge power is sent to the vehicle controller (VCU) and the EMS, so that the VCU coordinates the motor torque to ensure that the battery discharge power does not exceed the maximum discharge power, and the EMS simultaneously adjusts the engine output so that the total power does not exceed the maximum discharge power. If the battery voltage or temperature exceeds the safe range, the maximum discharge power will be forcibly set to 0.

6. The method according to claim 5, characterized in that, The steps for calculating the maximum discharge power based on the current battery charge include: Calculate the difference between the current power battery charge and 25%, and then calculate the quotient of the difference and 5% to obtain the power limitation coefficient; The maximum discharge power is obtained by multiplying the power limitation factor by the rated power.

7. The method according to claim 1, characterized in that, The method further includes: When the power battery charge is detected to be less than the fifth preset threshold, a level three fault lockout is executed.

8. The method according to claim 7, characterized in that, The first preset threshold, the second preset threshold, the third preset threshold, the fourth preset threshold, and the fifth preset threshold are respectively 34%, 33%, 32%, 30%, and 25%.

9. A low battery warning device for a hybrid electric vehicle, characterized in that, The device includes: The reminder module is used to output a specified text reminder message when the power battery charge is detected to be less than a first preset threshold. The early warning module is used to enter a rapid diagnosis window for a specified period when the power battery charge is detected to be less than the second preset threshold. It performs multi-dimensional dynamic verification in conjunction with the engine status sent by the engine management system (EMS). After the verification is passed, the safety warning is activated. The diagnostic module is used to perform a collaborative diagnostic process with the EMS when the power battery charge is detected to be less than a third preset threshold. The control module is used to control the power battery according to a preset power limiting strategy when the battery charge is detected to be less than a fourth preset threshold; wherein the first preset threshold, the second preset threshold, the third preset threshold and the fourth preset threshold decrease sequentially.

10. A low battery warning system for a hybrid electric vehicle, characterized in that, The system includes a BMS and an EMS; the BMS is communicatively connected to the EMS; the BMS is used to perform the method as described in any one of claims 1-8.

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