Vehicle braking deceleration compensation method and system

Abstract

The invention relates to a vehicle braking deceleration compensation method and system, and the method comprises the steps: judging whether to execute a braking force compensation control strategy or not based on the charge state of a power battery and the thermal state of a braking system; and if the state of charge of the power battery exceeds a preset threshold value and the braking system is in a cold state, executing a braking force compensation control strategy to obtain a compensation factor based on a friction coefficient-temperature model, and adjusting the original mechanical braking force under the current braking demand by using the compensation factor, the adjusted mechanical braking force is output to a braking executing mechanism; otherwise, executing a conventional braking force distribution strategy. When the braking system is in the cold state, the mechanical braking force instruction value is increased, so that braking force attenuation caused by friction coefficient reduction is effectively compensated, and it is ensured that the actual braking effect is matched with a deceleration target requested by a driver; accurate, safe and reliable output of the braking performance is achieved without depending on a fixed compensation coefficient or a static threshold value.

Description

Technical Field

[0001] This application relates to the field of vehicle braking, specifically to a vehicle braking deceleration compensation method and system. Background Technology

[0002] In new energy vehicles, regenerative braking systems are one of the key technologies for achieving energy conservation and improving driving range. The basic principle is to convert some of the kinetic energy generated during vehicle braking into electrical energy stored in the battery. This process is typically achieved through the reverse drag torque of the drive motor (i.e., electric braking). Under most conventional braking conditions, the vehicle's braking force is composed of mechanical braking (friction braking), electric braking, and driving resistance, i.e., F = Fmechanical + Felectric + Fresistance. When the battery charge is low, electric braking can handle a larger proportion of the braking demand, thereby reducing the load and wear on the mechanical braking system.

[0003] However, when the vehicle's battery is at a high state of charge (e.g., SOC > 95%), electric braking is usually significantly limited or completely disengaged due to the battery's limited energy absorption capacity or to protect against overcharging. In this case, all braking demands must be met by the mechanical braking system. On the other hand, when a vehicle has been stationary for an extended period (especially in low-temperature environments), the brake pads and discs are in a "cold state," with their coefficient of friction significantly lower than the nominal value under normal operating conditions. If braking is attempted under these conditions, especially when the electric braking system cannot provide assistance under a fully charged state, insufficient actual braking force will result in a vehicle braking deceleration lower than the driver's expectations, affecting braking safety and driving experience. Summary of the Invention

[0004] This application provides a vehicle braking deceleration compensation method and system, which can solve the problem of insufficient braking deceleration caused by the lack of electric braking and the reduction of friction coefficient under fully charged and cold conditions in the prior art.

[0005] In a first aspect, embodiments of this application provide a vehicle braking deceleration compensation method, which includes: Based on the state of charge of the power battery and the thermal state of the braking system, determine whether to execute the braking force compensation control strategy. If the state of charge of the power battery exceeds a preset threshold and the braking system is in a cold state, a braking force compensation control strategy is executed to obtain a compensation factor based on the friction coefficient-temperature model, and the original mechanical braking force under the current braking demand is adjusted using the compensation factor, and the adjusted mechanical braking force is output to the braking actuator. Otherwise, the conventional braking force distribution strategy will be implemented.

[0006] In conjunction with the first aspect, in one embodiment, the determination that the braking system is in a cold state includes: The vehicle has been stationary for longer than the calibration threshold corresponding to the current ambient temperature. Or the initial temperature of the braking friction pair is lower than the preset cold-state temperature threshold.

[0007] In conjunction with the first aspect, in one implementation, the exit condition of the braking force compensation control strategy includes: The cumulative number of effective braking events reaches a preset exit threshold. The effective braking events include: the absolute value of braking deceleration is greater than a preset threshold and the duration reaches a preset safe duration. Or the state of charge of the power battery drops below a preset threshold.

[0008] In conjunction with the first aspect, in one implementation method, the compensation factor is obtained based on the friction coefficient-temperature model, specifically including: Based on the friction coefficient-temperature model, the friction coefficient corresponding to the current ambient temperature is obtained; A compensation factor is generated based on the friction coefficient.

[0009] In conjunction with the first aspect, in one implementation method, obtaining the friction coefficient corresponding to the current ambient temperature based on the friction coefficient-temperature model includes: During the initial braking phase, the current ambient temperature is substituted into the friction coefficient-temperature model to calculate the friction coefficient. In the subsequent braking phase, the ambient temperature is calculated based on the vehicle braking data. This ambient temperature is then used as the current ambient temperature and substituted into the friction coefficient-temperature model to obtain the friction coefficient. The vehicle braking data includes braking pressure data, wheel speed data, and braking energy data.

[0010] In conjunction with the first aspect, in one embodiment, generating a compensation factor based on the friction coefficient specifically includes: Calculate the percentage deviation between the coefficient of friction and the nominal coefficient of friction; A compensation factor is generated based on the deviation ratio and the compensation correction amount.

[0011] In conjunction with the first aspect, in one embodiment, the method further includes the step of obtaining a compensation correction amount: Under the braking force compensation control strategy, the deviation data between the actual deceleration and the requested deceleration in each effective braking event is recorded; Statistical analysis is performed on the deviation data of the requested deceleration falling within the same preset deceleration segment interval to generate a compensation correction amount that reflects the vehicle wear status.

[0012] In conjunction with the first aspect, in one implementation, the compensation correction amount is stored in segments according to the requested deceleration segment intervals, wherein each requested deceleration segment interval corresponds to a compensation correction amount.

[0013] In conjunction with the first aspect, in one implementation, the obtained compensation factor satisfies the following condition: the compensation factor is less than a preset upper limit threshold. When outputting the adjusted mechanical braking force, the following condition must be met: the rate of change of the output mechanical braking force is within the preset smoothness range.

[0014] Secondly, embodiments of this application provide a vehicle braking deceleration compensation system, comprising: a first module and a second module. The first module is used to: determine whether to execute a braking force compensation control strategy based on the state of charge of the power battery and the thermal state of the braking system; the second module is used to: execute a braking force compensation control strategy when the state of charge of the power battery exceeds a preset threshold and the braking system is in a cold state, to obtain a compensation factor based on a friction coefficient-temperature model, and to adjust the original mechanical braking force under the current braking demand using the compensation factor, and output the adjusted mechanical braking force to the braking actuator; and execute a conventional braking force distribution strategy when the state of charge of the power battery is below a preset threshold and the braking system is not in a cold state.

[0015] The beneficial effects of the technical solutions provided in this application include: This application provides a vehicle braking deceleration compensation method and system. A friction coefficient-temperature model serves as the foundation, mapping the impact of temperature changes on friction performance. The model dynamically acquires compensation factors and adjusts mechanical braking force commands, enabling the braking system to respond in real-time to the friction coefficient decay characteristics of the braking friction pair under cold conditions. When the braking system is cold, the mechanical braking force command value is increased, effectively compensating for the braking force decay caused by the decrease in friction coefficient, ensuring that the actual braking effect matches the deceleration target requested by the driver. This method eliminates the need for fixed compensation coefficients or static thresholds, solving the problem of the braking force output being out of sync with demand under cold conditions, and achieving accurate, safe, and reliable braking performance output. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the vehicle braking deceleration compensation method of this application; Figure 2 This is a schematic diagram illustrating the process of refining the compensation factor based on the friction coefficient-temperature model in this application. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0018] This application provides a vehicle braking deceleration compensation method and system, which can solve the problem of insufficient braking deceleration caused by the lack of electric braking and the reduction of friction coefficient under fully charged and cold conditions in the prior art.

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0020] In a first aspect, embodiments of this application provide a vehicle braking deceleration compensation method, which includes: 101: Based on the state of charge of the power battery and the thermal state of the braking system, determine whether to execute the braking force compensation control strategy; 102: If the state of charge of the power battery exceeds a preset threshold and the braking system is in a cold state, a braking force compensation control strategy is executed to obtain a compensation factor based on the friction coefficient-temperature model, and the original mechanical braking force under the current braking demand is adjusted using the compensation factor, and the adjusted mechanical braking force is output to the braking actuator. 103: Otherwise, execute the conventional braking force distribution strategy.

[0021] In this application, the friction coefficient-temperature model serves as a fundamental tool, mapping the impact of temperature changes on friction performance. By dynamically acquiring compensation factors and adjusting mechanical braking force commands through the friction coefficient-temperature model, the braking system can respond in real time to the friction coefficient decay characteristics of the braking friction pair under cold conditions. When the braking system is in a cold state, the mechanical braking force command value is increased, thereby effectively compensating for the braking force decay caused by the decrease in friction coefficient, ensuring that the actual braking effect matches the deceleration target requested by the driver. Without relying on fixed compensation coefficients or static thresholds, this solves the problem of the braking force output being out of sync with demand under cold conditions, achieving accurate, safe, and reliable braking performance output.

[0022] The core of this application lies in dynamically identifying the combined working conditions of a vehicle being fully charged (e.g., SOC>95%) and the braking system being in a cold state (determined by a combination of ambient temperature, vehicle stationary time, and recent effective braking count). The system estimates the current braking friction coefficient in real time and learns and optimizes compensation parameters based on historical braking data to adaptively adjust the mechanical braking force output.

[0023] The friction coefficient-temperature model is the basic model of the vehicle braking deceleration compensation system. By measuring and calibrating the friction coefficients of the friction pads and brake discs under different temperature conditions in the braking system bench test, the mapping relationship between the friction coefficient μ and the temperature T is established, μ=f(T). This model is obtained through a standardized test procedure and stored in the non-volatile memory of the vehicle controller.

[0024] In practical applications, the system reads ambient temperature sensor data in real time or estimates the initial temperature of the brake disc based on the vehicle's stationary time, and inputs it into the model to calculate the current friction coefficient μcurrent. For example, when the ambient temperature is below 15°C and the vehicle has been stationary for more than 20 minutes, the system calls the model to output the corresponding μcurrent value, providing a real-time basis for subsequent compensation.

[0025] In the vehicle's conventional control strategy, the original mechanical braking force command F 机械 Based on the nominal friction coefficient μ nom The reference friction coefficient (obtained under standard test conditions) is used for calculation and allocation to ensure consistency in the braking force distribution logic; similarly, the actual braking force F provided by the electric braking system is calculated and allocated accordingly. 电 It will be equivalently converted to μ-based nom The mechanical braking force value allows for coordinated management of the braking forces of electric braking and mechanical braking under a unified benchmark. This design avoids issues arising when the friction coefficient changes (such as μ in a cold state). current <μ nom This addresses the deviation in braking force calculation caused by the vehicle's braking force distribution strategy, ensuring its stable operation under normal conditions. It also provides a comparable benchmark input for the compensation control strategy, enabling the system to accurately identify braking force loss and implement dynamic adjustments.

[0026] This solution uses multi-dimensional information fusion to dynamically determine whether the vehicle has entered a specific operating condition that requires compensation. In other words, it determines whether to execute the braking force compensation control strategy based on the state of charge of the power battery and the thermal state of the braking system.

[0027] Step 101 includes determining the full-charge state and the cold-state state. The full-charge state determination is achieved by real-time monitoring of the battery's state of charge (SOC). The system continuously obtains real-time SOC data from the battery management system. When the SOC value exceeds a preset threshold (e.g., 95%), the system automatically determines that the vehicle is fully charged, at which point the electric braking system is restricted or disabled. This preset threshold (e.g., 95%) is commonly used after vehicle charging is complete or in high-charge driving scenarios. It aims to avoid electric braking energy recovery when the battery is close to full charge (e.g., SOC ≥ 95%), preventing the risk of battery thermal runaway due to overcharging or affecting battery life. In the fully charged state, the electric braking function is actively shut down, causing the braking system to operate entirely in mechanical braking mode. This provides a clear trigger point for subsequent compensation control, ensuring that the system activates the compensation strategy only under specific conditions where electric braking cannot intervene. This solves the problem of braking force loss caused by the lack of electric braking and improves the stability and consistency of braking performance in high-charge scenarios.

[0028] When determining the cold state, not only the resting time but also the ambient temperature and braking history must be considered. In this embodiment, the determination that the braking system is in a cold state includes: the vehicle's resting time exceeds the calibration threshold corresponding to the current ambient temperature; or the initial temperature of the brake friction pair is lower than a preset cold state temperature threshold.

[0029] Specifically, in determining the cold state, the system achieves accurate operating condition identification through multi-parameter fusion: When a vehicle starts from a standstill and meets one of the following conditions, the braking system is initially determined to be in a "cold state": Real-time monitoring of vehicle idle time ΔT; if it exceeds the time threshold ΔTth(Tamb) calibrated by looking up a table based on ambient temperature Tamb (for example, the lower the ambient temperature, the longer the calibrated threshold ΔTth(Tamb) will be), then a cold state judgment is triggered. Alternatively, the system can call a pre-stored friction coefficient-temperature model to calculate the initial temperature T of the brake disc / pad based on the ambient temperature or an initial estimated temperature. est If T est Below the preset cold temperature threshold T cold If so, the braking system is determined to be in a cold state; In addition, the system integrates historical braking data. After activating the braking force compensation control strategy, the system begins recording the number of effective braking events, using the cumulative number of effective braking events as a condition for determining whether the braking force compensation control strategy should be discontinued. In this embodiment, the effective braking event includes: the absolute value of braking deceleration being greater than a preset threshold value 'a'. th And the duration reaches the preset safe duration δt th .

[0030] The exit conditions for the braking force compensation control strategy include: the cumulative number of effective braking events reaching a preset exit threshold, or the state of charge of the power battery dropping below a preset threshold.

[0031] Specifically, the determination of a valid braking event is based on the absolute value of the braking deceleration being greater than a preset threshold value 'a'. th And the duration reaches the preset safe duration δt th To ensure the braking process has sufficient strength and duration to accurately reflect changes in the coefficient of friction and avoid false triggering caused by brief bumps; this preset threshold value a th The system is dynamically adjusted based on the vehicle's real-time driving status, for example, by appropriately increasing the speed as the vehicle speed increases, in order to avoid misjudgment in low-speed, light-braking scenarios.

[0032] When the cumulative number of effective braking events reaches the preset exit threshold n set by the system. exit (n) exitWhen the system is calibrated according to the vehicle model and braking system characteristics, it automatically exits the compensation mode, indicating that the braking system has achieved temperature recovery through multiple effective braking processes and the friction coefficient has returned to a level close to the nominal value. At the same time, if the state of charge (SOC) of the power battery drops below the preset threshold (such as below 95%), the electric braking system resumes normal operation and the compensation strategy is terminated immediately.

[0033] This exit mechanism accurately identifies the improvement process of the braking system's thermal state by integrating historical braking data with battery status. It avoids continuing to implement compensation after the friction coefficient recovers, preventing excessive braking force from causing excessively long braking distances or abnormal brake pedal feel. This ensures that the vehicle smoothly transitions to the conventional braking control strategy during driving, maintaining the stability of braking performance and consistency with the driver's expectations.

[0034] When the system determines that the vehicle is simultaneously in a fully charged and cold state, it triggers the adaptive braking force compensation logic, which means executing the braking force compensation control strategy.

[0035] Based on the above embodiments, in this embodiment, the compensation factor is obtained based on the friction coefficient-temperature model, specifically including: first, obtaining the friction coefficient corresponding to the current ambient temperature based on the friction coefficient-temperature model; and then generating the compensation factor based on the friction coefficient.

[0036] In this embodiment, the friction coefficient corresponding to the current ambient temperature is obtained based on the friction coefficient-temperature model, including: During the initial braking phase, the current ambient temperature is substituted into the friction coefficient-temperature model to calculate the friction coefficient. In the specific implementation of obtaining the compensation factor based on the friction coefficient-temperature model, the system can use the ambient temperature value collected in real time by the ambient temperature sensor (such as the external temperature data after the vehicle has been stationary), or the initial temperature value estimated by historical information such as vehicle stationary time and ambient temperature (for example, the initial temperature of the brake disc is estimated based on the correlation model between stationary time and ambient temperature), and substitute it into the pre-stored friction coefficient-temperature model (μ=f(T)) to calculate the initial friction coefficient μ. current ; In the subsequent braking phase, based on vehicle braking data, the ambient temperature is calculated and used as the current ambient temperature. This temperature is then substituted into the friction coefficient-temperature model to obtain the friction coefficient. The vehicle braking data includes braking pressure data, wheel speed data, and braking energy data. The system dynamically updates the friction coefficient by continuously analyzing multi-source data during the braking process. Specifically, based on braking pressure data (reflecting the intensity of the brake pedal input and the magnitude of the braking force) and wheel speed data (reflecting wheel deceleration and slip ratio changes), the system estimates the temperature rise of the brake disc / pad in real time using a vehicle dynamics model. For example, it calculates the instantaneous heat load by correlating braking pressure with the wheel speed change rate, or uses a braking energy accumulation model (mapping the total energy obtained by integrating braking pressure and time to temperature change) to estimate the current temperature state. The estimated temperature is then substituted into the μ=f(T) model to update μ. current .

[0037] During each braking process, the system automatically switches estimation strategies—initially relying on simplified estimation based on ambient temperature, and gradually transitioning to high-precision online identification based on real-time braking signals as braking events accumulate (e.g., the number of cumulative effective braking events increases), ensuring μ current It can accurately reflect the actual thermal state of the braking friction pair; this phased dynamic estimation mechanism avoids deviations caused by relying solely on ambient temperature (such as the system misjudging the cold state when the vehicle has just completed braking at low temperatures), and at the same time, through real-time feedback of braking energy data, the compensation factor λ=μ nom / μ current The calculation is closer to the actual degree of friction coefficient loss, thus providing accurate input for mechanical braking force adjustment and improving the adaptability and reliability of the compensation strategy under different braking scenarios.

[0038] Based on the above embodiments, in this embodiment, the generation of a compensation factor according to the friction coefficient specifically includes: First, calculate the deviation ratio between the current friction coefficient and the nominal friction coefficient: calculate the deviation ratio of the current friction coefficient relative to the nominal value, i.e., the compensation coefficient λ: λ = μ nom / μ current (Usually λ≥1); then, based on the deviation ratio and the compensation correction amount, a compensation factor is generated.

[0039] In this embodiment, the compensation factor is a dynamic compensation factor, and the dynamic compensation factor k comp The key is that its calculation comprehensively considers both real-time friction coefficient deviation and historical learning data.

[0040] The specific formula is k comp =1+α (λ 1)+β Δk learn ; Where α is the real-time deviation weighting coefficient (0 < α ≤ 1), used to dynamically adjust the system's response intensity to the current friction coefficient deviation, ensuring that the compensation can quickly adapt to changes in the braking system's thermal state, and is calibrable; β is the learning weighting coefficient (0 ≤ β ≤ 1), used to adjust the confidence level of historical learning data, avoiding compensation deviations caused by single operating condition data. Δklearn is the self-learning correction term, i.e., the compensation correction amount, obtained through learning from historical data.

[0041] Compensation correction amount Δk learn The acquisition process is as follows: Under the braking force compensation control strategy, the deviation data between the actual deceleration and the requested deceleration in each effective braking event is recorded; the deviation data of the requested deceleration falling within the same preset deceleration segment interval are statistically analyzed to generate a compensation correction amount reflecting the vehicle wear state.

[0042] Under the braking force compensation control strategy, the system automatically records key parameters for each effective braking event, including requested deceleration, actual deceleration, and compensation factor k. comp and the estimated friction coefficient μ current The requested deceleration is then divided into several preset intervals (e.g., low speed 0-2 m / s², medium speed 2-4 m / s², high speed 4 m / s² and above). Statistical analysis is performed on the deviation data (the difference between the actual deceleration and the requested deceleration) from multiple braking operations within each interval to calculate the average deviation value for that interval. Based on this, the system generates the corresponding Δk. learn The correction value is used to compensate for the loss of braking force within this range.

[0043] It should be noted that Δk learn The storage format can be a fixed value, but more commonly, the compensation correction amount is stored in segments according to the requested deceleration intervals, where each requested deceleration interval corresponds to a compensation correction amount. That is, the corresponding Δk is stored independently for each velocity interval. learn Value; As vehicle mileage increases, the system continuously updates the mapping table: after each effective braking, it automatically calculates the average deviation contribution of the new data to the corresponding interval and dynamically adjusts the mapping table value to make Δk learn Gradually adapt to the wear level, temperature gradient, and driver's pedaling habits of the vehicle's brake pads, such as the initial Δk of a new car. learn Approaching 0, as the number of braking cycles accumulates, the system identifies a persistently low coefficient of friction due to wear, Δk learn The value gradually increases and stabilizes within a reasonable range, ensuring the compensation factor k comp It can accurately compensate for braking force loss at different stages of use, avoiding fluctuations in braking performance caused by wear or differences in driving style.

[0044] Based on the above embodiments, in this embodiment, the original mechanical braking force under the current braking demand is adjusted using a compensation factor, and the adjusted mechanical braking force is output to the braking actuator: The system is based on the nominal friction coefficient μ nom Calculated original mechanical braking force command F 机械 Through dynamic compensation factor k comp Make real-time adjustments and generate the compensated instruction F′ 机械 =F 机械 ×k comp This process ensures that the mechanical braking force can accurately compensate for the loss caused by the reduction in the coefficient of friction under fully charged and cold operating conditions.

[0045] Furthermore, it should be emphasized that in this application, in order to ensure braking safety and driving smoothness, the system implements a dual constraint mechanism: the generated compensation factor satisfies the following: the compensation factor is less than a preset upper limit threshold; when outputting the adjusted mechanical braking force, the following is satisfied: the rate of change of the output mechanical braking force is within a preset smoothness range.

[0046] In other words, compensation factor k comp Strictly limited to a preset upper limit threshold k comp_max (This threshold is calibrated based on the maximum output capability of the braking system) to avoid F′ 机械 Exceeding the physical limits of the braking actuator to prevent wheel lock-up or brake overload; simultaneously, the system controls F′ 机械 The rate of change is dynamically monitored, and its change per second is limited to a preset smoothness threshold to ensure a smooth transition of braking force output and avoid brake vibration, abnormal pedal feedback or sudden changes in vehicle longitudinal acceleration caused by compensation abrupt changes.

[0047] During actual braking, the system continuously monitors the real-time status of ABS and ESC. When ABS detects that the wheel slip ratio exceeds the safety threshold or ESC initiates stability intervention, the compensation control strategy is immediately suspended, and the braking actuator prioritizes the response to ABS / ESC commands, ensuring that active safety functions always have the highest priority. For example, during the first braking on a cold winter road surface, the system uses k... comp The system dynamically increases braking force to compensate for the loss of friction coefficient in cold conditions. If the system detects that the road surface is slippery and the wheels are about to lock up, it immediately terminates the compensation and switches to ABS control to maintain the stability of braking distance and driving comfort. This allows the compensation strategy to be seamlessly integrated within the safety boundary, improving braking performance under specific conditions without sacrificing the reliability of the vehicle's active safety system.

[0048] In summary, this solution has the following advantages: Precise compensation enhances safety and experience: For the specific and common dangerous situation of "fully charged and cold" (such as starting with a full charge on a winter morning), dynamic recognition and adaptive compensation effectively make up for the insufficient braking force caused by the lack of electric braking and low friction coefficient, making the actual deceleration more in line with the driver's expectations, shortening the cold braking distance, and significantly improving driving safety and driver confidence.

[0049] Dynamic adaptive control: It abandons the simple method of fixed multiple compensation and adopts a dynamic compensation factor based on real-time friction coefficient estimation and historical data learning, so that the compensation is more accurate and more in line with the current actual condition of the vehicle (such as wear, temperature gradient) and driver habits, avoiding over-compensation or under-compensation.

[0050] Introducing self-learning capability: The system can accumulate and analyze historical braking data, continuously optimize compensation parameters, making the control strategy more and more accurate as the vehicle is used over time, possessing personalized adaptability, and improving the system's intelligence and long-term effectiveness.

[0051] More robust operating condition identification: By combining multiple parameters such as ambient temperature, resting time, and effective braking count for cold state determination and management, it is more scientific and reliable than a single time threshold, and can more accurately reflect the actual thermal state of the braking system.

[0052] Smooth Integration and Safety Assurance: As a higher-level optimization strategy, this solution can be seamlessly integrated with existing regenerative braking systems and ESC systems. Compensation control always operates within the safety framework of the vehicle stability control system, setting safety boundaries to ensure that function activation does not affect the vehicle's active safety performance.

[0053] Enhancing brand value: Effectively addressing user complaints about braking performance in specific scenarios, especially in the competitive new energy vehicle market, can highlight the vehicle's attention to detail in safety and user experience, thus helping to improve product reputation and brand influence.

[0054] Secondly, embodiments of this application provide a vehicle braking deceleration compensation system, comprising: a first module and a second module. The first module is used to: determine whether to execute a braking force compensation control strategy based on the state of charge of the power battery and the thermal state of the braking system; the second module is used to: execute a braking force compensation control strategy when the state of charge of the power battery exceeds a preset threshold and the braking system is in a cold state, to obtain a compensation factor based on a friction coefficient-temperature model, and to adjust the original mechanical braking force under the current braking demand using the compensation factor, and output the adjusted mechanical braking force to the braking actuator; and execute a conventional braking force distribution strategy when the state of charge of the power battery is below a preset threshold and the braking system is not in a cold state.

[0055] In this application, a compensation factor is dynamically obtained based on a friction coefficient-temperature model, and the mechanical braking force command is adjusted to enable the braking system to respond in real time to the friction coefficient decay characteristics of the braking friction pair under cold conditions. The core of this mechanism lies in the fact that the friction coefficient-temperature model, as a fundamental tool, maps the impact of temperature changes on friction performance. The generated compensation factor adaptively adjusts the mechanical braking force output intensity according to the deviation ratio between the current friction coefficient and the nominal operating condition. When the braking system is in a cold state, the characteristic of a compensation factor greater than 1 directly increases the mechanical braking force command value, thereby effectively compensating for the braking force decay caused by the decrease in friction coefficient, ensuring that the actual braking effect highly matches the deceleration target requested by the driver. Simultaneously, the compensation adjustment process is executed within the safety framework of the vehicle stability control system. The amplitude and rate of change of the compensation factor are dynamically limited by safety boundary constraints, avoiding the risk of wheel lock-up or brake shudder caused by over-compensation, ensuring that the braking response meets performance requirements while maintaining system dynamic stability. This technology does not rely on fixed compensation coefficients or static thresholds. Instead, it uses real-time friction conditions as input for dynamic decision-making, fundamentally solving the physical contradiction of the disconnect between braking force output and demand under cold conditions, and achieving precise, safe and reliable braking performance output.

[0056] The functions of each module in the above-mentioned vehicle braking deceleration compensation system correspond to the steps in the above-mentioned vehicle braking deceleration compensation method embodiment, and their functions and implementation processes will not be described in detail here.

[0057] Thirdly, embodiments of this application provide a vehicle braking deceleration compensation device, which can be a personal computer (PC), laptop computer, server, or other device with data processing capabilities.

[0058] In this embodiment, the vehicle braking deceleration compensation device may include a processor, a memory, a communication interface, and a communication bus.

[0059] The communication bus can be of any type and is used to interconnect the processor, memory, and communication interface.

[0060] The communication interface includes input / output (I / O) interfaces, physical interfaces, and logical interfaces used for interconnecting internal components of the vehicle braking deceleration compensation device, as well as interfaces used for interconnecting the vehicle braking deceleration compensation device with other devices (such as other computing devices or user equipment). Physical interfaces can be Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc.; user equipment can be displays, keyboards, etc.

[0061] Memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0062] The processor can be a general-purpose processor, which can call the vehicle braking deceleration compensation program stored in the memory and execute the vehicle braking deceleration compensation method provided in the embodiments of this application. For example, the general-purpose processor can be a central processing unit (CPU). The method executed when the vehicle braking deceleration compensation program is called can be referred to in the various embodiments of the vehicle braking deceleration compensation method of this application, and will not be repeated here.

[0063] Fourthly, embodiments of this application also provide a computer-readable storage medium.

[0064] The present application provides a computer-readable storage medium storing a vehicle braking deceleration compensation program, wherein when the vehicle braking deceleration compensation program is executed by a processor, it implements the steps of the vehicle braking deceleration compensation method as described above.

[0065] The method implemented when the vehicle braking deceleration compensation procedure is executed can be referred to in various embodiments of the vehicle braking deceleration compensation method of this application, and will not be repeated here.

[0066] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0067] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.

[0068] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.

[0069] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0070] In some processes described in the embodiments of this application, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of this application, or they may be executed in parallel. The sequence number of the operation is only used to distinguish different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed sequentially or in parallel, and these operations or steps may be combined.

[0071] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of this application.

[0072] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method for compensating for vehicle braking deceleration, characterized in that, It includes: Based on the state of charge of the power battery and the thermal state of the braking system, determine whether to execute the braking force compensation control strategy. If the state of charge of the power battery exceeds a preset threshold and the braking system is in a cold state, a braking force compensation control strategy is executed to obtain a compensation factor based on the friction coefficient-temperature model, and the original mechanical braking force under the current braking demand is adjusted using the compensation factor, and the adjusted mechanical braking force is output to the braking actuator. Otherwise, the conventional braking force distribution strategy will be implemented.

2. The vehicle braking deceleration compensation method as described in claim 1, characterized in that, The determination that the braking system is in a cold state includes: The vehicle has been stationary for longer than the calibration threshold corresponding to the current ambient temperature. Or the initial temperature of the braking friction pair is lower than the preset cold-state temperature threshold.

3. The vehicle braking deceleration compensation method as described in claim 1, characterized in that, The exit conditions for the braking force compensation control strategy include: The cumulative number of effective braking events reaches a preset exit threshold. The effective braking events include: the absolute value of braking deceleration is greater than a preset threshold and the duration reaches a preset safe duration. Or the state of charge of the power battery drops below a preset threshold.

4. The vehicle braking deceleration compensation method as described in claim 1, characterized in that, The compensation factor is obtained based on the friction coefficient-temperature model, specifically including: Based on the friction coefficient-temperature model, the friction coefficient corresponding to the current ambient temperature is obtained; A compensation factor is generated based on the friction coefficient.

5. The vehicle braking deceleration compensation method as described in claim 4, characterized in that, Based on the friction coefficient-temperature model, the friction coefficient corresponding to the current ambient temperature is obtained, specifically including: During the initial braking phase, the current ambient temperature is substituted into the friction coefficient-temperature model to calculate the friction coefficient. In the subsequent braking phase, the ambient temperature is calculated based on the vehicle braking data. This ambient temperature is then used as the current ambient temperature and substituted into the friction coefficient-temperature model to obtain the friction coefficient. The vehicle braking data includes braking pressure data, wheel speed data, and braking energy data.

6. The vehicle braking deceleration compensation method as described in claim 4, characterized in that, The compensation factor is generated based on the friction coefficient, specifically including: Calculate the percentage deviation between the coefficient of friction and the nominal coefficient of friction; A compensation factor is generated based on the deviation ratio and the compensation correction amount.

7. The vehicle braking deceleration compensation method as described in claim 6, characterized in that, The method further includes the step of obtaining the compensation correction amount: Under the braking force compensation control strategy, the deviation data between the actual deceleration and the requested deceleration in each effective braking event is recorded; Statistical analysis is performed on the deviation data of the requested deceleration falling within the same preset deceleration segment interval to generate a compensation correction amount that reflects the vehicle wear status.

8. The vehicle braking deceleration compensation method as described in claim 7, characterized in that: The compensation correction amount is stored in segments according to the requested deceleration intervals, with each requested deceleration interval corresponding to a compensation correction amount.

9. The vehicle braking deceleration compensation method as described in claim 1, characterized in that: The obtained compensation factor satisfies the following condition: the compensation factor is less than a preset upper limit threshold. When outputting the adjusted mechanical braking force, the following condition must be met: the rate of change of the output mechanical braking force is within the preset smoothness range.

10. A vehicle braking deceleration compensation system, characterized in that, It includes: The first module is used to determine whether to execute the braking force compensation control strategy based on the state of charge of the power battery and the thermal state of the braking system. The second module is used to: execute a braking force compensation control strategy when the state of charge of the power battery exceeds a preset threshold and the braking system is in a cold state, to obtain a compensation factor based on the friction coefficient-temperature model, and to adjust the original mechanical braking force under the current braking demand using the compensation factor, and output the adjusted mechanical braking force to the braking actuator; and execute a conventional braking force distribution strategy when the state of charge of the power battery is below a preset threshold and the braking system is not in a cold state.

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