Vehicle braking control method and device, electronic equipment and storage medium

Abstract

The embodiment of the invention provides a vehicle braking control method and device, electronic equipment and a storage medium. In response to a dynamic braking condition, the wheel deceleration, the wheel deceleration threshold value and the target braking parameter of a vehicle in the braking process are obtained; the target braking parameters comprise the target slip rate, the target wheel deceleration and the target braking time; determining a high attachment side of the vehicle according to the wheel deceleration and the wheel deceleration threshold; the high attachment side corresponds to parking force; acquiring an initial braking parameter corresponding to the high attachment side; the initial braking parameters comprise the initial slip rate and the initial braking time; and according to the wheel deceleration, the initial braking parameter and the target braking parameter, the parking force corresponding to the high attachment side is controlled. According to the embodiment of the invention, by identifying the road surface where the vehicle is located, the high attachment side of the vehicle can be rapidly and accurately identified, the parking force of the high attachment side is independently controlled based on multiple parameters such as the wheel deceleration, the slip rate and the braking time, and the stability and efficiency of vehicle braking are improved.

Description

Technical Field

[0001] This application relates to the field of control technology, and in particular to a vehicle braking control method, device, electronic device, and storage medium. Background Technology

[0002] Currently, when a vehicle's EPB (Electrical Park Brake) performs dynamic braking, it calculates the slip ratio of the left and right rear wheels separately and controls the parking force independently. When it detects that the slip ratio of a wheel on one side exceeds a set threshold, the system will release the parking force on that side to prevent the wheel from locking up.

[0003] However, current parking force control schemes typically employ a uniform braking logic across different road surfaces. On split-surface surfaces (e.g., one side with low traction and the other with high traction), the lower parking force on the low-traction side causes the load to shift to the high-traction side, further increasing the parking force on that side. Although current parking force control schemes calculate and monitor the slip ratio of each wheel in real time and adjust the parking force accordingly, in certain specific conditions, such as one side being a wet tile surface and the other a dry asphalt surface, and the dry asphalt surface on the high-traction side potentially becoming wet due to splashing water, the wheels on the high-traction side may lock up when encountering a wet, slippery area. Once lockup occurs, if the driver does not correct it in time through steering, vehicle stability will decrease. Furthermore, because current parking force control schemes only adjust the parking force on the high-traction side through a "clamp-release" cycle based on slip ratio, the wheels will repeatedly switch between locked and unlocked states, affecting braking comfort and causing an overall decrease in deceleration, thus degrading braking performance. Summary of the Invention

[0004] This application provides a vehicle braking control method, device, electronic device, and storage medium, aiming to improve the current parking force control scheme, which adjusts the parking force on the high-adjacent side based solely on the slip ratio, thus affecting vehicle braking performance.

[0005] To address the above problems, this application discloses a vehicle braking control method, including:

[0006] In response to dynamic braking conditions, the vehicle acquires wheel deceleration, wheel deceleration threshold, and target braking parameters during braking; the target braking parameters include target slip ratio, target wheel deceleration, and target braking time.

[0007] The high attachment side of the vehicle is determined based on the wheel deceleration and the wheel deceleration threshold; the high attachment side corresponds to the parking force.

[0008] Obtain the initial braking parameters corresponding to the high-adhesion side; the initial braking parameters include the initial slip ratio and the initial braking time.

[0009] The parking force corresponding to the high-adhesion side is controlled based on the wheel deceleration, the initial braking parameters, and the target braking parameters.

[0010] Optionally, obtaining the target braking parameters includes:

[0011] Obtain the friction coefficient between the vehicle's wheels and the ground, and determine the first slip ratio based on the friction coefficient;

[0012] Acquire lock-up data of the vehicle in a locked state, and determine a second slip ratio and a target single clamping time based on the lock-up data; the first slip ratio is less than the second slip ratio;

[0013] Acquire the vehicle's driving data on a high-friction surface, and determine the target wheel deceleration based on the driving data;

[0014] The target parking force of the vehicle during braking is obtained, and the total target clamping time is determined based on the target parking force.

[0015] The target interval time is determined based on the target wheel deceleration and the target parking force;

[0016] The first slip ratio and the second slip ratio are determined as the target slip ratio, and the total target clamping time, the single target clamping time, and the target interval time are determined as the target braking time.

[0017] Optionally, the wheel deceleration includes the wheel deceleration corresponding to the wheels on both sides of the vehicle, and determining the high-side of the vehicle based on the wheel deceleration and the wheel deceleration threshold includes:

[0018] If the wheel deceleration of one side of the vehicle is less than the wheel deceleration threshold and the wheel deceleration of the other side of the vehicle is greater than the wheel deceleration threshold, then the side with the wheel deceleration less than the wheel deceleration threshold is determined as the high-attached side.

[0019] Optionally, the wheel deceleration includes the wheel deceleration corresponding to the high-friction side, the initial braking time includes the initial total clamping time, the initial single clamping time, and the initial interval time, and the step of controlling the parking force corresponding to the high-friction side based on the wheel deceleration, the initial braking parameters, and the target braking parameters includes:

[0020] If the wheel deceleration corresponding to the high-adhesion side is less than the target wheel deceleration, the first comparison result is obtained;

[0021] A second comparison result is determined based on the initial slip ratio and the target slip ratio;

[0022] If the initial total clamping time is less than the target total clamping time, and the initial single clamping time is greater than the target single clamping time, and the initial interval time is greater than the target interval time, a third comparison result is obtained;

[0023] Based on the first comparison result, the second comparison result, and the third comparison result, the parking force corresponding to the high attachment side is controlled.

[0024] Optionally, determining the second comparison result based on the initial slip ratio and the target slip ratio includes:

[0025] If the initial slip ratio is less than the first slip ratio, a first result is obtained;

[0026] If the initial slip ratio is greater than or equal to the first slip ratio, and the initial slip ratio is greater than the second slip ratio, a second result is obtained;

[0027] If the initial slip ratio is greater than or equal to the first slip ratio, and the initial slip ratio is less than or equal to the second slip ratio, a third result is obtained;

[0028] The first result, the second result, or the third result is determined as the second comparison result.

[0029] Optionally, controlling the parking force corresponding to the high-adhesion side based on the first comparison result, the second comparison result, and the third comparison result includes:

[0030] Based on the first comparison result, the first result, and the third comparison result, increase the parking force corresponding to the high-attachment side;

[0031] Based on the first comparison result, the second result, and the third comparison result, reduce the parking force corresponding to the high attachment side;

[0032] Based on the first comparison result, the third result, and the third comparison result, maintain the parking force corresponding to the high attachment side.

[0033] This application also discloses a vehicle braking control device, including:

[0034] The acquisition module is used to acquire, in response to dynamic braking conditions, the wheel deceleration, wheel deceleration threshold, and target braking parameters of the vehicle during the braking process; the target braking parameters include target slip ratio, target wheel deceleration, and target braking time.

[0035] A high-attachment-side determination module is used to determine the high-attachment-side of the vehicle based on the wheel deceleration and the wheel deceleration threshold; the high-attachment-side corresponds to the parking force.

[0036] An initial braking parameter acquisition module is used to acquire the initial braking parameters corresponding to the high-adhesion side; the initial braking parameters include the initial slip ratio and the initial braking time.

[0037] The parking force control module is used to control the parking force corresponding to the high-adhesion side based on the wheel deceleration, the initial braking parameters, and the target braking parameters.

[0038] This application also discloses an electronic parking control system, which is applied to the vehicle braking control method described in any of the embodiments of this application.

[0039] This application also discloses an electronic device, including a processor and a memory, wherein the memory is used to store computer programs; the processor is used to execute the programs stored in the memory to implement the vehicle braking control method described in any of the embodiments of this application.

[0040] This application also discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the vehicle braking control method described in any of the embodiments of this application.

[0041] The embodiments of this application have the following advantages:

[0042] In this embodiment, in response to dynamic braking conditions, the wheel deceleration, wheel deceleration threshold, and target braking parameters of the vehicle during braking are obtained; the target braking parameters include target slip ratio, target wheel deceleration, and target braking time; the high-attachment side of the vehicle is determined based on the wheel deceleration and the wheel deceleration threshold; the high-attachment side corresponds to a parking force; the initial braking parameters corresponding to the high-attachment side are obtained; the initial braking parameters include initial slip ratio and initial braking time; the parking force corresponding to the high-attachment side is controlled based on the wheel deceleration, the initial braking parameters, and the target braking parameters. This application embodiment acquires the wheel deceleration during vehicle braking in real time and compares it with a preset wheel deceleration threshold. This allows for rapid and accurate identification of the side of the road surface with high traction (i.e., the high-traction side). By pre-setting target braking parameters, including target slip ratio, target wheel deceleration, and target braking time, and determining the initial braking parameters corresponding to the high-traction side, a clear reference benchmark and constraints can be established for the fine control of parking force. By comprehensively comparing the differences between real-time wheel deceleration, initial braking parameters, and target braking parameters, the parking force on the high-traction side can be dynamically and precisely adjusted, rather than simply performing a "clamp-release" cycle. This enables the control system to suppress excessive growth of the parking force on the high-traction side in advance under complex conditions such as split-road surfaces, preventing vehicle instability or entering a lock-up-release oscillation cycle due to excessive braking force. Thus, while ensuring vehicle stability, a smoother and more efficient vehicle braking effect is achieved. Attached Figure Description

[0043] Figure 1 This is a flowchart of the vehicle braking control method provided in the embodiments of this application;

[0044] Figure 2 This is a structural diagram of the vehicle braking control device provided in the embodiments of this application;

[0045] Figure 3 This is a structural diagram of the electronic device provided in the embodiments of this application. Detailed Implementation

[0046] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0047] Current parking force control schemes typically employ an independent control strategy based on slip ratio. The Electronic Parking Brake (EPB) system calculates the slip ratio for each of the left and right rear wheels separately, and independently releases the parking force on that side to prevent wheel lock-up when the slip ratio of a single wheel exceeds a set threshold. This scheme uses a uniform braking logic across different road surfaces, lacking the ability to identify the road surface adhesion coefficient. In split-road conditions, this uniform logic can lead to insufficient braking force on the low-adhesion side, causing load transfer and a continuous increase in braking force on the high-adhesion side. When the vehicle passes through a region of abrupt change in adhesion coefficient (such as when water suddenly appears on the high-adhesion side), excessive braking force can easily cause wheel lock-up.

[0048] Because the EPB system was originally designed for static parking, its motor power and dynamic control logic are ill-suited to the demands of high-speed dynamic braking. When lock-up occurs on the high-traction side, the system can only adjust through a delayed "clamp-release" cycle, which causes the vehicle to generate a destabilizing yaw moment. Furthermore, the loss of lateral traction after lock-up on the high-traction side leads to a loss of lateral stability, resulting in a decrease in overall deceleration and an increase in braking distance. Simultaneously, the motor's long reversal response time causes the vehicle to oscillate continuously between locked and unlocked states, affecting braking comfort and posing a significant risk of instability.

[0049] It should be noted that wheel lock-up refers to the phenomenon where the wheels completely stop rotating due to excessive braking force when a vehicle brakes suddenly, causing the tires to slide and rub against the ground, making the vehicle unable to move normally.

[0050] This application provides a vehicle braking control method. Please refer to the following embodiments. Figure 1 This includes the following steps:

[0051] Step 101: In response to dynamic braking conditions, obtain the wheel deceleration, wheel deceleration threshold, and target braking parameters of the vehicle during the braking process; the target braking parameters include target slip ratio, target wheel deceleration, and target braking time.

[0052] In this embodiment, the dynamic braking condition is triggered when all three of the following conditions are met simultaneously: the vehicle speed is greater than 3 kph, the driver pulls the EPB switch, and the hydraulic braking of the Integrated Brake Control System (IBCS) fails. When the dynamic braking condition is triggered, it indicates that the vehicle needs to rely on the Electronic Parking Brake (EPB) system for dynamic deceleration. At this time, it is necessary to obtain the corresponding vehicle state and target parameters, namely the wheel deceleration, wheel deceleration threshold, and target braking parameters during the braking process.

[0053] Specifically, wheel deceleration refers to the decrease in wheel angular velocity per unit time. It directly reflects the outcome of the interaction between braking torque and ground braking force, and is a key early indicator for determining whether the wheel is about to lock up; wheel deceleration threshold 'a' Thres This refers to a preset value calibrated according to the actual situation of the vehicle, used to compare with the actual wheel deceleration, thereby quickly distinguishing between high-traction and low-traction road surfaces; the target braking parameters refer to the set of ideal state values ​​that are expected to be achieved to optimize the braking process, including the target slip ratio, target wheel deceleration, and target braking time.

[0054] It should be noted that although the wheel deceleration threshold and target wheel deceleration in the embodiments of this application are both used for comparison with the wheel deceleration, the two are not directly related.

[0055] As an example, the wheel deceleration of a vehicle during braking can be calculated from the wheel speed sensor signal installed on the wheel. This method of acquisition is only an example and is not limited to the embodiments of this application.

[0056] Step 102: Determine the high attachment side of the vehicle based on the wheel deceleration and the wheel deceleration threshold; the high attachment side corresponds to the parking force;

[0057] In this embodiment of the application, the wheel deceleration threshold a is used to measure the wheel deceleration. Thres Comparisons can enable the vehicle to identify the road surface it is on. Specifically, based on the size relationship between the two, it can be determined whether the road surface the vehicle is currently on is a split road surface. In the case of a split road surface, it can also quickly determine which side of the vehicle is the high-adhesion side. The high-adhesion side refers to the side of the vehicle with a higher road surface adhesion coefficient. The wheels on this side can provide greater braking force, but it also carries the risk of vehicle instability due to excessive braking force.

[0058] Current parking force control schemes typically do not separately control the parking force on different sides of the vehicle for special conditions such as split-slip roads. Therefore, they cannot predict the potential risk of locking on the high-adhesion side and can only perform delayed and violent "clamp-release" adjustments after the slip ratio exceeds the limit. However, in the embodiments of this application, the road surface where the vehicle is located is identified by wheel deceleration. The high-adhesion side can be identified early and accurately in split-slip road conditions, thereby providing a key decision basis for subsequent implementation of predictive and refined parking force constraint control and avoiding instability from the source.

[0059] Specifically, although road surface recognition is essentially directly related to the road surface adhesion coefficient, wheel deceleration is the most direct and sensitive real-time parameter reflecting the dynamic game between braking torque and ground braking force. Its rate of change can detect the sudden change in wheel adhesion state earlier than parameters such as slip ratio. Therefore, in the embodiments of this application, the road surface where the vehicle is located can be recognized by wheel deceleration.

[0060] It should be noted that although wheel deceleration is related to the road adhesion coefficient, directly measuring the road adhesion coefficient in real time is extremely difficult and costly in engineering practice. Wheel deceleration, on the other hand, can be conveniently calculated using standard wheel speed sensor signals, offering high real-time performance and reliability. More importantly, in the early identification of split-type road surfaces, the wheel deceleration of the high-adhesion side wheel is significantly lower than that of the low-adhesion side due to its ability to provide greater braking force. This difference appears earlier and more pronounced than the difference in slip ratio, allowing wheel deceleration-based identification methods to more quickly and accurately pinpoint the high-adhesion side, gaining valuable time for the early intervention of subsequent control strategies. Therefore, even if other parameters indirectly related to the adhesion coefficient exist, this application prioritizes wheel deceleration as the basis for road surface identification.

[0061] Step 103: Obtain the initial braking parameters corresponding to the high-adhesion side; the initial braking parameters include the initial slip ratio and the initial braking time;

[0062] In this embodiment, once the high-attachment side of the vehicle is determined, the parking force on the high-attachment side needs to be controlled according to the control logic of the opposing road surface. During the control process, it is necessary to obtain the initial braking parameters related to the braking process on the high-attachment side so that the parking force on the high-attachment side can be processed separately based on the relevant braking parameters. The initial braking parameters include the initial slip ratio and the initial braking time. Specifically, the initial slip ratio refers to the current real-time slip ratio calculation value of the wheel on the high-attachment side, and the initial braking time refers to the total clamping time accumulated from the start of the application of the parking force on the high-attachment side to the current moment, the duration of the most recent clamping operation, and the interval between two adjacent clamping operations.

[0063] As an example, the vehicle's slip ratio can be determined by calculating the wheel speed sensor signal and the estimated vehicle reference speed; the initial total clamping time can be determined by the cumulative working time recorded by the EPB motor controller; the initial single clamping time can be determined by the duration of continuous motor power supply during the most recent clamping operation; and the initial interval time can be determined by the time difference between the start times of two consecutive clamping operations.

[0064] It should be noted that while the high-attachment side of the vehicle is identified, the other side of the vehicle is the low-attachment side. Since the adhesion coefficient of the low-attachment side is very low and its contribution to the deceleration of the whole vehicle is very small, it is only necessary to ensure that the vehicle does not lock up. Therefore, in this embodiment, the parking force corresponding to the low-attachment side is directly controlled by the basic anti-lock braking logic (that is, the parking force is released immediately when the slip ratio is detected to exceed the release threshold). In other words, it is not necessary to obtain the braking parameters related to the low-attachment side for separate control logic.

[0065] Step 104: Control the parking force corresponding to the high-adhesion side based on the wheel deceleration, the initial braking parameters, and the target braking parameters.

[0066] In traditional parking force control schemes, the decision to clamp or release the parking force is usually based solely on whether the slip ratio exceeds a single fixed threshold. This is a passive and delayed reactive control method.

[0067] In this embodiment, the parking force corresponding to the high-adhesion side is controlled by comprehensively comparing and deciding on the real-time wheel deceleration, slip ratio, and braking time with the preset target wheel deceleration, target slip ratio, and target braking time in multiple dimensions.

[0068] Compared to the traditional single slip ratio threshold control method, the embodiments of this application introduce wheel deceleration as an early warning indicator and use multiple time parameters (total time, single time, interval time) to actively constrain and finely schedule the braking force growth process. This can achieve predictive and gradual adjustment of the high-adhesion parking force under the condition of two-way road surface.

[0069] Specifically, relying solely on slip ratio only allows intervention when the wheels are already nearing lockup, which is too late. However, the embodiments of this application use wheel deceleration to reflect changes in wheel dynamics earlier, providing early warning. Furthermore, the braking time parameter proactively limits the unlimited increase of parking force from the perspectives of energy input and thermal management. Based on multi-parameter fusion control of parking force, a shift from "post-event remediation" to "pre-event prevention" is achieved.

[0070] Furthermore, single slip ratio control can easily lead to drastic switching of parking force between the two extreme states of "clamping-releasing," causing vehicle vibration and instability risks. This application's embodiment uses braking time as the basis for parking force control, enabling smooth and gradual control of braking force, avoiding impacts, and greatly improving vehicle stability.

[0071] Meanwhile, traditional methods typically only have the single objective of "preventing wheel lock-up," often at the expense of braking performance. This application's embodiment establishes an efficient and stable braking operating range by combining target wheel deceleration and target slip ratio. This allows the EPB to actively maintain the high-tether side wheel near this optimal range while ensuring vehicle stability, thus simultaneously balancing braking performance (deceleration) and driving stability.

[0072] It should be noted that the parking force mentioned in the embodiments of this application refers to the frictional torque generated by the electronic parking brake (EPB) system driving the brake caliper through an actuator (such as a motor) to press the friction pads against the brake disc. This torque acts on the wheels to decelerate the vehicle or maintain a parking state. Clamping refers to the process by which the EPB system controls the actuator to move the friction pads toward the brake disc and apply a clamping force, which increases the braking torque. Releasing refers to the process by which the EPB system controls the actuator to move in the opposite direction, causing the friction pads to disengage from the brake disc or reducing the clamping force, thereby reducing or releasing the braking torque.

[0073] This application embodiment acquires the wheel deceleration during vehicle braking in real time and compares it with a preset wheel deceleration threshold. This allows for rapid and accurate identification of the side of the road surface with high traction (i.e., the high-traction side). By pre-setting target braking parameters, including target slip ratio, target wheel deceleration, and target braking time, and determining the initial braking parameters corresponding to the high-traction side, a clear reference benchmark and constraints can be established for the fine control of parking force. By comprehensively comparing the differences between real-time wheel deceleration, initial braking parameters, and target braking parameters, the parking force on the high-traction side can be dynamically and precisely adjusted, rather than simply performing a "clamp-release" cycle. This enables the control system to suppress excessive growth of the parking force on the high-traction side in advance under complex conditions such as split-road surfaces, preventing vehicle instability or entering a lock-up-release oscillation cycle due to excessive braking force. Thus, while ensuring vehicle stability, a smoother and more efficient vehicle braking effect is achieved.

[0074] In one embodiment of this application, obtaining the target braking parameters includes:

[0075] Obtain the friction coefficient between the vehicle's wheels and the ground, and determine the first slip ratio based on the friction coefficient;

[0076] Acquire lock-up data of the vehicle in a locked state, and determine a second slip ratio and a target single clamping time based on the lock-up data; the first slip ratio is less than the second slip ratio;

[0077] Acquire the vehicle's driving data on a high-friction surface, and determine the target wheel deceleration based on the driving data;

[0078] The target parking force of the vehicle during braking is obtained, and the total target clamping time is determined based on the target parking force.

[0079] The target interval time is determined based on the target wheel deceleration and the target parking force;

[0080] The first slip ratio and the second slip ratio are determined as the target slip ratio, and the total target clamping time, the single target clamping time, and the target interval time are determined as the target braking time.

[0081] In this embodiment, the target braking parameters are determined based on a large amount of vehicle test data, vehicle dynamics theory, and safety standards. The purpose is to provide an ideal target range and safety boundary for high-friction side parking force control that is both efficient and stable. The acquisition methods and setting basis of each parameter are as follows:

[0082] Determination of target slip ratio (S) 目标 With S 释放 ):

[0083] Obtain the first slip ratio S 目标 The friction coefficient between the vehicle's wheels and the ground is obtained through bench or real-vehicle testing, and the slip ratio range (typically 15%-20%) that provides the maximum longitudinal adhesion coefficient is analyzed. An optimal value within this range is determined as the first slip ratio S based on the friction coefficient. 目标 This parameter is set so that the control system can maintain the wheel slip ratio near this optimal range, thereby making better use of ground adhesion and obtaining the best braking performance.

[0084] Obtain the second slip ratio S 释放 Acquire vehicle lock-up data, such as the vehicle dynamics response when the slip ratio is close to 100%, and determine a safety threshold as the second slip ratio S based on the lock-up data. 释放 It should be noted that the first slip ratio S 目标 It needs to be less than the second slip ratio S 释放 Its function is to serve as an inviolable safety red line. When the initial slip ratio exceeds this value, the release operation is triggered immediately to prevent the vehicle from locking up, which is the ultimate guarantee for stability.

[0085] Determination of target braking time (t) 总 t 每次 t 间隔 ):

[0086] Total clamping time t of the target 总: Obtain the target parking force of the vehicle during braking (i.e., the maximum parking force that can be applied on the high-adhesion side without causing instability), and determine a maximum force accumulation time limit, i.e., the total target clamping time t, based on the target parking force and the characteristics of the system motor. 总 This time must be less than the clamping time to reach the maximum parking force. This time constraint limits the maximum clamping force at its source, preventing the vehicle from becoming unstable due to excessive braking force.

[0087] Target single clamping time t 每次 Based on locking data (such as motor response characteristics and vehicle instability critical points), determine the upper limit of the duration of a single clamping operation, i.e., the target single clamping time t. 每次 This parameter is set to refine the clamping time for each parking maneuver, allowing for more precise control over the increase in deceleration and preventing the vehicle from locking up and becoming unstable due to excessively long clamping times.

[0088] Target interval time t 间隔 Based on the desired smoothness requirements of the target wheel deceleration and target parking force, determine the minimum waiting time between two clamping operations, i.e., the target interval time t. 间隔 This parameter is designed to ensure that the deceleration increases gradually, rather than increasing to a large force all at once or very quickly, which could cause the vehicle to become unstable. This allows sufficient time to monitor the vehicle's condition and evaluate the effectiveness of the previous operation.

[0089] Determination of target wheel deceleration (a) 目标 ):

[0090] Acquire vehicle driving data on high-adhesion surfaces (such as performing full braking tests on dry asphalt surfaces), and determine the maximum stable deceleration value that the vehicle can achieve on a surface with ideal adhesion based on the driving data. Use this value as the target wheel deceleration 'a'. 目标 This parameter is set to prevent the vehicle from locking up due to continuously increasing deceleration. It is typically set based on a deceleration rate greater than that specified in enterprise and international standards (e.g., enterprise standards require a rate greater than 2.2 m / s²). 2 The actual setting is based on the maximum deceleration value that different vehicles can achieve in actual tests on high-friction surfaces, aiming to fully tap the braking potential while ensuring safety.

[0091] The first slip ratio S can be obtained through the above method. 目标 Second slip ratio S 释放 Total clamping time t of the target 总 Target single clamping time t 每次 Target interval time t 间隔 and target wheel deceleration a 目标 and the first slip ratio S 目标 Second slip ratio S释放 The target slip ratio is jointly determined (i.e., the optimal control range and safety boundary are defined), and the total target clamping time t is... 总 Target single clamping time t 每次 The time interval t between the target and the target 间隔 The target braking time was determined together (i.e., the rhythm and total amount of force applied were defined).

[0092] Compared to traditional methods that rely solely on slip ratio for hysteresis control, this application's embodiment integrates friction coefficient, lock-up data, and driving test data to pre-set a set of target braking parameters covering the target slip ratio range, target wheel deceleration, and multi-dimensional target braking time. This provides a refined control benchmark for high-adhesion parking force that balances braking performance and stability, fundamentally avoiding excessive braking force growth and vehicle instability risks, and achieving a fundamental shift from passive response to active optimization.

[0093] In one embodiment of this application, the wheel deceleration includes the wheel deceleration corresponding to the wheels on both sides of the vehicle, and determining the high-side of the vehicle based on the wheel deceleration and the wheel deceleration threshold includes:

[0094] If the wheel deceleration of one side of the vehicle is less than the wheel deceleration threshold and the wheel deceleration of the other side of the vehicle is greater than the wheel deceleration threshold, then the side with the wheel deceleration less than the wheel deceleration threshold is determined as the high-attached side.

[0095] In practical applications, the wheel deceleration generated on the low-friction side of a vehicle is much greater than that generated on the high-friction side. However, this embodiment uses a wheel deceleration threshold as the absolute criterion for road surface identification, rather than directly comparing the wheel decelerations on both sides of the vehicle. This is because directly comparing the relative magnitudes of the wheel decelerations on both sides can only determine the difference in road surface adhesion, but cannot distinguish whether the vehicle is on a split road surface or a uniformly low-friction road surface. This embodiment introduces a pre-calibrated absolute threshold (wheel deceleration threshold a). Thres It can effectively distinguish between high and low adhesion road surfaces, ensuring that targeted control strategies are only triggered when there is a truly high adhesion side (one side is above the threshold and the other side is below the threshold), thus avoiding false intervention on uniformly low adhesion road surfaces.

[0096] It should be noted that the wheel deceleration in this embodiment includes the wheel deceleration corresponding to the left and right wheels of the vehicle. The wheel deceleration of the left and right rear wheels can be directly used as the wheel deceleration corresponding to the left and right wheels of the vehicle. Specifically, the high-adhesion side is determined based on the wheel deceleration and the wheel deceleration threshold. This is mainly achieved by comparing the wheel deceleration of each side with the threshold. The high-adhesion side wheel can provide greater braking force and therefore has a smaller wheel deceleration, while the low-adhesion side wheel is more prone to slippage and therefore has a larger wheel deceleration, thereby accurately identifying the side with high adhesion.

[0097] As an example, suppose the wheel deceleration threshold a Thres =3.0m / s 2 When the deceleration of the left rear wheel is 4.5 m / s² 2 (greater than wheel deceleration threshold a) Thres The deceleration of the right rear wheel is 2.0 m / s². 2 (less than the wheel deceleration threshold a) Thres When the right side is determined to be the high-attached side and the left side to be the low-attached side, the control logic provided in the embodiments of this application can be applied to the parking force of the right wheel.

[0098] This application's embodiment introduces an absolute wheel deceleration threshold as the basis for road surface identification, which can accurately distinguish between split-type road surfaces and uniform low-adhesion road surfaces, effectively avoiding miscontrol on uniform low-adhesion road surfaces. At the same time, based on the characteristics of small wheel deceleration on the high-adhesion side and large wheel deceleration on the low-adhesion side, the high-adhesion side can be quickly and accurately identified, providing a reliable basis for subsequent implementation of targeted control strategies, thereby improving the vehicle stability control effect when braking on split-type road surfaces from the source.

[0099] In one embodiment of this application, the wheel deceleration includes the wheel deceleration corresponding to the high-friction side, the initial braking time includes the initial total clamping time, the initial single clamping time, and the initial interval time, and the step of controlling the parking force corresponding to the high-friction side according to the wheel deceleration, the initial braking parameters, and the target braking parameters includes:

[0100] If the wheel deceleration corresponding to the high-adhesion side is less than the target wheel deceleration, the first comparison result is obtained;

[0101] A second comparison result is determined based on the initial slip ratio and the target slip ratio;

[0102] If the initial total clamping time is less than the target total clamping time, and the initial single clamping time is greater than the target single clamping time, and the initial interval time is greater than the target interval time, a third comparison result is obtained;

[0103] Based on the first comparison result, the second comparison result, and the third comparison result, the parking force corresponding to the high attachment side is controlled.

[0104] In this embodiment, different comparison results are obtained for different parameters. Specifically, by continuously monitoring the real-time wheel deceleration of the high-adhesion side and comparing it with the target wheel deceleration, if the wheel deceleration of the high-adhesion side is less than the target wheel deceleration, it indicates that there is still room for improvement in the current braking force, the vehicle state is stable, and it is possible to consider increasing the parking force. At this time, the first comparison result is obtained. The second comparison result can be determined based on the initial slip ratio and the target slip ratio. This result is used to determine the slip state of the current wheel, which is the key to preventing lock-up and ensuring stability in the control logic. At the same time, it is checked whether the braking operation time history of the high-adhesion side is within the safe range. If the initial total clamping time is less than the target total clamping time (indicating that the total braking force has not exceeded the limit), and the initial single clamping time is greater than the target single clamping time (indicating that the single force increase can be more refined safely), and the initial interval time is greater than the target interval time (indicating that the system has enough time to respond to the previous operation), then the third comparison result is obtained. This comparison result is a safe premise for performing any force increase or decrease operation.

[0105] For parking force control on the high-adhesion side, a joint decision needs to be made based on the first comparison result (wheel deceleration state), the second comparison result (slip ratio state), and the third comparison result (time safety) to output the final control command (increase, decrease, or maintain) for the parking force on the high-adhesion side.

[0106] Based on the above comparison results, it can be understood that the comparison results can be used as the triggering condition for the next parking force control. Specifically, based on the relevant parameters of the first braking process, the triggering time of the second braking process is determined, and so on, based on the triggering time of the second braking process, the triggering time of the third braking process is determined.

[0107] It should be noted that the target total clamping time refers to the total time for clamping the high-adhesion side. A longer total clamping time results in a longer stroke for the screw to push the piston forward, thus increasing the force exerted by the piston to clamp the brake disc and generate a greater parking force. Setting a target total clamping time limits the maximum parking force that the high-adhesion side can generate, fundamentally avoiding the risk of vehicle instability due to excessive braking force. The target single clamping time refers to the upper limit of the duration of a single clamping operation. A longer single clamping time generates a greater clamping force. Setting a target single clamping time allows control over the deceleration generated with each clamping, enabling more precise control over the increase in deceleration. The target interval time refers to the interval between each clamping operation. Because the EPB caliper motor has relatively low power and a slow response time, the parking force gradually increases. Setting a target interval time prevents the clamping force from rapidly increasing and locking the vehicle, and also allows for more precise control over vehicle deceleration and slip ratio.

[0108] This application embodiment, by integrating real-time wheel deceleration status, slip ratio range status, and multi-dimensional braking time safety conditions, not only effectively identifies whether the wheels are about to lock up, but also introduces additional slip state judgment and time safety premise verification below the ideal range. This avoids control lag, oscillation, or misoperation problems caused by single effective thresholds or response delays in traditional control from multiple dimensions. By setting target total clamping time, target single clamping time, and target interval time, constraints are implemented from three levels: total parking force, single force increase magnitude, and system response recovery. While fully exploring the high-friction side braking potential, it ensures the smoothness, controllability, and system robustness of braking force growth, fundamentally eliminating the risk of excessive braking force output and vehicle instability, and significantly improving the braking stability and safety of the vehicle under low-friction road conditions.

[0109] In one embodiment of this application, determining the second comparison result based on the initial slip ratio and the target slip ratio includes:

[0110] If the initial slip ratio is less than the first slip ratio, a first result is obtained;

[0111] If the initial slip ratio is greater than or equal to the first slip ratio, and the initial slip ratio is greater than the second slip ratio, a second result is obtained;

[0112] If the initial slip ratio is greater than or equal to the first slip ratio, and the initial slip ratio is less than or equal to the second slip ratio, a third result is obtained;

[0113] The first result, the second result, or the third result is determined as the second comparison result.

[0114] In this embodiment of the application, if the initial slip ratio is less than the first slip ratio, i.e., S目标 This indicates that the wheel slip ratio is below the ideal adhesion range, and the braking force is not fully utilized, resulting in the first result; if the initial slip ratio is greater than or equal to the first slip ratio S 目标 And simultaneously greater than the second slip ratio S 释放 This indicates that the wheels are nearing lockup, posing a risk to stability, leading to the second result; if the initial slip ratio is greater than or equal to the first slip ratio S... 目标 And simultaneously less than or equal to the second slip ratio S 释放 This indicates that the wheel is in an ideal range with high and stable adhesion utilization, yielding the third result. The first, second, or third result is then designated as the second comparison result, serving as the basis for subsequent parking force control.

[0115] In traditional parking force control schemes, only the initial slip ratio and the second slip ratio S are typically considered. 释放 The relationship between the magnitudes of the initial slip ratio and the second slip ratio S is considered, focusing only on whether the wheels are about to lock up and determining whether to release braking force accordingly. However, in the embodiments of this application, it is necessary to consider not only the initial slip ratio and the second slip ratio S 释放 The magnitude relationship between them also needs to consider the initial slip ratio and the first slip ratio S. 目标 The magnitude relationship between them can be used to distinguish the three different states of slip ratio: above, below, or within the ideal range.

[0116] This application embodiment introduces a first slip ratio S. 目标 This judgment dimension can more accurately identify the actual adhesion state of the wheels, taking into account both anti-lock braking requirements and braking force utilization efficiency, thereby achieving more precise and adaptive control of the parking force on the high-adhesion side and improving the braking safety and stability of the vehicle under low-adhesion road conditions.

[0117] In one embodiment of this application, controlling the parking force corresponding to the high-adhesion side based on the first comparison result, the second comparison result, and the third comparison result includes:

[0118] Based on the first comparison result, the first result, and the third comparison result, increase the parking force corresponding to the high-attachment side;

[0119] Based on the first comparison result, the second result, and the third comparison result, reduce the parking force corresponding to the high attachment side;

[0120] Based on the first comparison result, the third result, and the third comparison result, maintain the parking force corresponding to the high attachment side.

[0121] In this embodiment, controlling the parking force corresponding to the high-adhesion side mainly includes three control strategies: increasing, decreasing, and maintaining. Since the core challenge of dynamic braking on split-road surfaces is to fully utilize the braking potential of the high-adhesion side while strictly preventing excessive braking force from causing vehicle instability or wheel lock-up, traditional single control actions cannot simultaneously address the three core requirements of "improving braking efficiency," "preventing over-braking," and "maintaining stability." Therefore, refined decision-making and execution are necessary based on the real-time determined vehicle state (a combination of results from wheel deceleration, slip ratio, and time safety). Different vehicle states will result in different combinations of comparative results, meaning different control strategies are required. The specific strategies are as follows:

[0122] Conditions for increasing parking force: Based on the first comparison result (low wheel deceleration, force can be increased), the second result (low slip ratio, force needs to be increased), and the third comparison result (time is safe, operable), the control actuator needs to increase the parking force corresponding to the high-attachment side. This is an active strategy to improve braking performance under the premise of safety. In this state, the vehicle has high stability and insufficient braking force utilization. Active force increase is the optimal and safest choice to improve overall braking performance and shorten braking distance.

[0123] Conditions for reducing parking force: Based on the first comparison result (low wheel deceleration, force can be increased), the second result (excessive slip ratio, dangerous), and the third comparison result (safe in time, operable), the control actuator needs to reduce the parking force corresponding to the high-attachment side. This is a protective strategy that prioritizes stability when a risk is identified. Although the wheel deceleration index shows that there is still room for force increase, the slip ratio has triggered a danger warning. At this point, stability takes priority over braking performance. Timely force reduction is a protective intervention aimed at quickly eliminating the risk of wheel lock-up and is a key measure to ensure vehicle stability and safety.

[0124] Conditions for maintaining parking force: Based on the first comparison result (low wheel deceleration, force can be increased), the third result (ideal slip ratio, stable), and the fourth comparison result (time safe, operable), the actuator maintains the parking force corresponding to the high-attachment side. This is the optimal strategy for maintaining the current efficient and stable state. This state is the ideal balance point pursued by braking control, where both braking performance and stability are at their best. Any unnecessary operation (increasing or decreasing force) may disrupt this balance, leading to decreased performance or triggering risks. Therefore, maintaining the status quo is the best strategy, aiming to consolidate and prolong this efficient and stable braking state.

[0125] This application embodiment achieves comprehensive control logic of parking force during different braking processes by dividing the vehicle into three control strategies. It can intelligently and dynamically balance the two core objectives of braking performance and driving stability during braking on open road surfaces, thereby achieving safe, efficient and smooth parking force control.

[0126] This application also provides a vehicle braking control device 20, please refer to... Figure 2 ,include:

[0127] The acquisition module 201 is used to acquire, in response to dynamic braking conditions, the wheel deceleration, wheel deceleration threshold, and target braking parameters of the vehicle during the braking process; the target braking parameters include target slip ratio, target wheel deceleration, and target braking time.

[0128] High attachment side determination module 202 is used to determine the high attachment side of the vehicle based on the wheel deceleration and the wheel deceleration threshold; the high attachment side corresponds to the parking force.

[0129] The initial braking parameter acquisition module 203 is used to acquire the initial braking parameters corresponding to the high-adhesion side; the initial braking parameters include the initial slip ratio and the initial braking time.

[0130] The parking force control module 204 is used to control the parking force corresponding to the high-adhesion side based on the wheel deceleration, the initial braking parameters and the target braking parameters.

[0131] Optionally, obtaining the target braking parameters includes:

[0132] Obtain the friction coefficient between the vehicle's wheels and the ground, and determine the first slip ratio based on the friction coefficient;

[0133] Acquire lock-up data of the vehicle in a locked state, and determine a second slip ratio and a target single clamping time based on the lock-up data; the first slip ratio is less than the second slip ratio;

[0134] Acquire the vehicle's driving data on a high-friction surface, and determine the target wheel deceleration based on the driving data;

[0135] The target parking force of the vehicle during braking is obtained, and the total target clamping time is determined based on the target parking force.

[0136] The target interval time is determined based on the target wheel deceleration and the target parking force;

[0137] The first slip ratio and the second slip ratio are determined as the target slip ratio, and the total target clamping time, the single target clamping time, and the target interval time are determined as the target braking time.

[0138] Optionally, the wheel deceleration includes the wheel deceleration corresponding to the wheels on both sides of the vehicle, and the high-attachment side determination module 202 includes:

[0139] If the wheel deceleration of one side of the vehicle is less than the wheel deceleration threshold and the wheel deceleration of the other side of the vehicle is greater than the wheel deceleration threshold, then the side with the wheel deceleration less than the wheel deceleration threshold is determined as the high-attached side.

[0140] Optionally, the wheel deceleration includes the wheel deceleration corresponding to the high-attachment side, the initial braking time includes the initial total clamping time, the initial single clamping time, and the initial interval time, and the parking force control module 204 includes:

[0141] If the wheel deceleration corresponding to the high-adhesion side is less than the target wheel deceleration, the first comparison result is obtained;

[0142] A second comparison result is determined based on the initial slip ratio and the target slip ratio;

[0143] If the initial total clamping time is less than the target total clamping time, and the initial single clamping time is greater than the target single clamping time, and the initial interval time is greater than the target interval time, a third comparison result is obtained;

[0144] Based on the first comparison result, the second comparison result, and the third comparison result, the parking force corresponding to the high attachment side is controlled.

[0145] Optionally, determining the second comparison result based on the initial slip ratio and the target slip ratio includes:

[0146] If the initial slip ratio is less than the first slip ratio, a first result is obtained;

[0147] If the initial slip ratio is greater than or equal to the first slip ratio, and the initial slip ratio is greater than the second slip ratio, a second result is obtained;

[0148] If the initial slip ratio is greater than or equal to the first slip ratio, and the initial slip ratio is less than or equal to the second slip ratio, a third result is obtained;

[0149] The first result, the second result, or the third result is determined as the second comparison result.

[0150] Optionally, controlling the parking force corresponding to the high-adhesion side based on the first comparison result, the second comparison result, and the third comparison result includes:

[0151] Based on the first comparison result, the first result, and the third comparison result, increase the parking force corresponding to the high-attachment side;

[0152] Based on the first comparison result, the second result, and the third comparison result, reduce the parking force corresponding to the high attachment side;

[0153] Based on the first comparison result, the third result, and the third comparison result, maintain the parking force corresponding to the high attachment side.

[0154] This application also provides an electronic parking control system, which is applied to the vehicle braking control method described in any of the embodiments of this application.

[0155] This application also provides an electronic device 30, please refer to... Figure 3 It includes a processor 310 and a memory 320, wherein the memory 310 is used to store computer programs; the processor 320 is used to execute the programs stored in the memory 310 to implement the vehicle braking control method described in any embodiment of this application.

[0156] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the vehicle braking control method described in any embodiment of this application.

[0157] In this application, "multiple" refers to two or more.

[0158] In this application, unless otherwise expressly defined, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0159] The terms “first,” “second,” “third,” “fourth,” etc., in this application (if present) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0160] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0161] Unless otherwise specified, all steps in this application may be performed sequentially or randomly. For example, if the method includes steps A and B, it means that the method may include steps A and B performed sequentially, or it may include steps B and A performed sequentially. For example, if the method may also include step C, it means that step C may be added to the method in any order. For example, the method may include steps A, B, and C, or it may include steps A, C, and B, or it may include steps C, A, and B, etc.

[0162] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A vehicle braking control method, characterized in that, include: In response to dynamic braking conditions, the wheel deceleration, wheel deceleration threshold, and target braking parameters of the vehicle during the braking process are obtained; The target braking parameters include target slip ratio, target wheel deceleration, and target braking time; The high attachment side of the vehicle is determined based on the wheel deceleration and the wheel deceleration threshold; the high attachment side corresponds to the parking force. Obtain the initial braking parameters corresponding to the high-adhesion side; the initial braking parameters include the initial slip ratio and the initial braking time. The parking force corresponding to the high-adhesion side is controlled based on the wheel deceleration, the initial braking parameters, and the target braking parameters.

2. The method according to claim 1, characterized in that, Obtaining the target braking parameters includes: Obtain the friction coefficient between the vehicle's wheels and the ground, and determine the first slip ratio based on the friction coefficient; Acquire lock-up data of the vehicle in a locked state, and determine a second slip ratio and a target single clamping time based on the lock-up data; the first slip ratio is less than the second slip ratio; Acquire the vehicle's driving data on a high-friction surface, and determine the target wheel deceleration based on the driving data; The target parking force of the vehicle during braking is obtained, and the total target clamping time is determined based on the target parking force. The target interval time is determined based on the target wheel deceleration and the target parking force; The first slip ratio and the second slip ratio are determined as the target slip ratio, and the total target clamping time, the single target clamping time, and the target interval time are determined as the target braking time.

3. The method according to claim 1, characterized in that, The wheel deceleration includes the wheel deceleration corresponding to the wheels on both sides of the vehicle. Determining the high-side of the vehicle based on the wheel deceleration and the wheel deceleration threshold includes: If the wheel deceleration of one side of the vehicle is less than the wheel deceleration threshold and the wheel deceleration of the other side of the vehicle is greater than the wheel deceleration threshold, then the side with the wheel deceleration less than the wheel deceleration threshold is determined as the high-attached side.

4. The method according to claim 2, characterized in that, The wheel deceleration includes the wheel deceleration corresponding to the high-friction side; the initial braking time includes the initial total clamping time, the initial single clamping time, and the initial interval time; controlling the parking force corresponding to the high-friction side based on the wheel deceleration, the initial braking parameters, and the target braking parameters includes: If the wheel deceleration corresponding to the high-adhesion side is less than the target wheel deceleration, the first comparison result is obtained; A second comparison result is determined based on the initial slip ratio and the target slip ratio; If the initial total clamping time is less than the target total clamping time, and the initial single clamping time is greater than the target single clamping time, and the initial interval time is greater than the target interval time, a third comparison result is obtained; Based on the first comparison result, the second comparison result, and the third comparison result, the parking force corresponding to the high attachment side is controlled.

5. The method according to claim 4, characterized in that, The step of determining the second comparison result based on the initial slip ratio and the target slip ratio includes: If the initial slip ratio is less than the first slip ratio, a first result is obtained; If the initial slip ratio is greater than or equal to the first slip ratio, and the initial slip ratio is greater than the second slip ratio, a second result is obtained; If the initial slip ratio is greater than or equal to the first slip ratio, and the initial slip ratio is less than or equal to the second slip ratio, a third result is obtained; The first result, the second result, or the third result is determined as the second comparison result.

6. The method according to claim 5, characterized in that, The step of controlling the parking force corresponding to the high-adhesion side based on the first comparison result, the second comparison result, and the third comparison result includes: Based on the first comparison result, the first result, and the third comparison result, increase the parking force corresponding to the high-attachment side; Based on the first comparison result, the second result, and the third comparison result, reduce the parking force corresponding to the high attachment side; Based on the first comparison result, the third result, and the third comparison result, maintain the parking force corresponding to the high attachment side.

7. A vehicle braking control device, characterized in that, include: The acquisition module is used to acquire, in response to dynamic braking conditions, the wheel deceleration, wheel deceleration threshold and target braking parameters of the vehicle during the braking process; The target braking parameters include target slip ratio, target wheel deceleration, and target braking time; A high-attachment-side determination module is used to determine the high-attachment-side of the vehicle based on the wheel deceleration and the wheel deceleration threshold; the high-attachment-side corresponds to the parking force. An initial braking parameter acquisition module is used to acquire the initial braking parameters corresponding to the high-adhesion side; the initial braking parameters include the initial slip ratio and the initial braking time. The parking force control module is used to control the parking force corresponding to the high-adhesion side based on the wheel deceleration, the initial braking parameters, and the target braking parameters.

8. An electronic parking control system, characterized in that, Applied to the vehicle braking control method as described in any one of claims 1-6.

9. An electronic device, characterized in that, Including processor and memory, among which Memory, used to store computer programs; A processor for executing a program stored in memory to implement the method described in any one of claims 1-6.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method described in any one of claims 1-6.

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