Vehicle, control method and control device of braking system and computer readable storage medium

Abstract

The invention discloses a control method and device of a vehicle and a braking system and a computer readable storage medium. The method comprises the steps that the vehicle weight, the acceleration, the rolling radius and the reference braking efficiency of the vehicle and the braking requirement during braking this time are obtained; determining a hydraulic pressure of the brake line based on the brake demand; based on the vehicle weight, the accelerated speed, the rolling radius and the hydraulic pressure, the target braking efficiency during braking is determined; and correcting the reference braking efficiency based on the target braking efficiency. According to the method, the problem that the braking efficiency is inconsistent can be solved, and the relatively stable braking efficiency of the vehicle is guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of vehicles, and in particular, to a control method for a vehicle braking system, a computer-readable storage medium, a vehicle, and a control device for a vehicle braking system. Background Art

[0002] With the rapid development of energy vehicles, the research and application of new energy vehicles with regenerative braking function are of great significance. The current energy recovery control system has the problem of inconsistent braking efficiency generated by hydraulic braking, which is mainly reflected in the differences in braking efficiency between calibrated vehicles and mass-produced vehicles, as well as different life cycles of the same vehicle. This results in differences in deceleration generated by regenerative braking and hydraulic braking, making it difficult for drivers to adapt well to these two different braking conditions. The fundamental reason for this phenomenon is that the driver's target braking force is executed by hydraulic pressure, and the calculation of hydraulic pressure requires the invocation of braking efficiency parameters. However, the braking efficiency will vary for different vehicles and at different times. During the regenerative braking process, hydraulic and electric braking are coordinated for braking. When the two act simultaneously, the situation of deceleration differences occurs. Summary of the Invention

[0003] The present application aims to solve at least one of the technical problems in the related art to some extent. For this purpose, the first object of the present application is to propose a control method for a vehicle braking system, which obtains the vehicle weight, acceleration, rolling radius, reference braking efficiency, and braking demand during the current braking, determines the hydraulic pressure of the brake pipeline based on the braking demand, determines the target braking efficiency during the current braking based on the vehicle weight, acceleration, rolling radius, and hydraulic pressure, and corrects the reference braking efficiency based on the target braking efficiency. Thus, the problem of inconsistent braking efficiency can be solved, and relatively stable braking efficiency of the vehicle can be ensured.

[0004] The second object of the present application is to propose a computer-readable storage medium.

[0005] The third object of the present application is to propose a vehicle.

[0006] The fourth object of the present application is to propose a control device for a vehicle braking system.

[0007] To achieve the above object, an embodiment of the first aspect of the present application proposes a control method for a vehicle braking system, the method including: obtaining the vehicle weight, acceleration, rolling radius, reference braking efficiency, and braking demand during the current braking; determining the hydraulic pressure of the brake pipeline based on the braking demand; determining the target braking efficiency during the current braking based on the vehicle weight, the acceleration, the rolling radius, and the hydraulic pressure; and correcting the reference braking efficiency based on the target braking efficiency.

[0008] According to the control method of the vehicle braking system according to an embodiment of the present application, the vehicle weight, acceleration, rolling radius, reference braking efficiency, and braking demand during this braking are obtained. Based on the braking demand, the hydraulic pressure of the brake pipeline is determined. Based on the vehicle weight, acceleration, rolling radius, and hydraulic pressure, the target braking efficiency during this braking is determined. Based on the target braking efficiency, the reference braking efficiency is corrected. Thus, this method can solve the problem of inconsistent braking efficiency and ensure relatively stable braking efficiency of the vehicle.

[0009] In addition, the control method of the vehicle braking system according to the above embodiment of the present application may further have the following additional technical features:

[0010] According to an embodiment of the present application, the determining the target braking efficiency during this braking based on the vehicle weight, the acceleration, the rolling radius, and the hydraulic pressure includes: determining the target braking efficiency based on the ratio of the product of the vehicle weight, the acceleration, and the rolling radius to the hydraulic pressure.

[0011] According to an embodiment of the present application, the correcting the reference braking efficiency based on the target braking efficiency includes: determining the efficiency difference between the reference braking efficiency and the target braking efficiency; when the efficiency difference is greater than a preset difference, correcting the reference braking efficiency based on the sum of the reference braking efficiency and the result of the ratio of the product of the preset step size and the efficiency difference to the absolute value of the efficiency difference.

[0012] According to an embodiment of the present application, the vehicle braking system includes a hydraulic braking system and a regenerative braking system, and the method further includes: obtaining the road surface adhesion coefficient and the state of charge of the battery of the current road surface; determining the target braking system corresponding to the braking demand based on the road surface adhesion coefficient and the state of charge of the battery, where the target braking system includes the hydraulic braking system and the regenerative braking system.

[0013] According to an embodiment of the present application, the determining the target braking system corresponding to the braking demand based on the road surface adhesion coefficient and the state of charge of the battery includes: when the road surface adhesion coefficient is less than a preset adhesion coefficient threshold, determining the target braking system as the hydraulic braking system; when the road surface adhesion coefficient is greater than the preset adhesion coefficient threshold and the state of charge of the battery is greater than a preset state of charge threshold, determining the target braking system as the hydraulic braking system; when the road surface adhesion coefficient is greater than or equal to the preset adhesion coefficient threshold and the state of charge of the battery is less than the preset state of charge threshold, determining the target braking system based on the maximum recovery ability of the motor.

[0014] According to an embodiment of the present application, determining the target braking system based on the maximum recovery capacity of the motor includes: when the maximum recovery capacity is greater than or equal to the braking demand, determining the target braking system as the regenerative braking system; when the maximum recovery capacity is less than the braking demand, determining the target braking system as the regenerative braking system and the hydraulic braking system, wherein the braking force provided by the regenerative braking system is the maximum recovery capacity, and the braking force provided by the hydraulic braking system is the difference between the braking demand and the maximum recovery capacity.

[0015] According to an embodiment of the present application, the method further includes: obtaining the vehicle speed; when the vehicle speed is less than a preset vehicle speed threshold, determining the target braking system as the hydraulic braking system.

[0016] To achieve the above object, an embodiment of the second aspect of the present application provides a computer-readable storage medium, on which a program is stored, and when the program is executed by a processor, the control method of the vehicle braking system described above is implemented.

[0017] The computer-readable storage medium according to the embodiment of the present application can, by implementing the control method of the vehicle braking system described above when executed.

[0018] To achieve the above object, a vehicle provided by an embodiment of the third aspect of the present application includes a memory, a processor, and a program stored on the memory and executable on the processor. When the processor executes the program, the control method of the vehicle braking system described above is implemented.

[0019] The vehicle according to the embodiment of the present application can solve the problem of inconsistent braking efficiency and ensure relatively stable braking efficiency of the vehicle by executing the control method of the vehicle braking system described above.

[0020] To achieve the above object, an embodiment of the fourth aspect of the present application provides a control device for a vehicle braking system. The device includes: an acquisition module, configured to acquire the vehicle weight, acceleration, rolling radius, reference braking efficiency, and braking demand during the current braking of the vehicle; a first determination module, configured to determine the hydraulic pressure of the brake pipeline based on the braking demand; a second determination module, configured to determine the target braking efficiency during the current braking based on the vehicle weight, the acceleration, the rolling radius, and the hydraulic pressure; and a correction module, configured to correct the reference braking efficiency based on the target braking efficiency.

[0021] The control device of the vehicle braking system according to an embodiment of the present application, an acquisition module is configured to acquire the vehicle weight, acceleration, rolling radius, reference braking efficiency, and braking demand during the current braking of the vehicle, a first determination module is configured to determine the hydraulic pressure of the braking pipeline based on the braking demand, a second determination module is configured to determine the target braking efficiency during the current braking based on the vehicle weight, the acceleration, the rolling radius, and the hydraulic pressure, and a correction module is configured to correct the reference braking efficiency based on the target braking efficiency. Thus, the device can solve the problem of inconsistent braking efficiency and ensure relatively stable braking efficiency of the vehicle.

[0022] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a flowchart of a control method for a vehicle braking system according to an embodiment of the present application;

[0024] Figure 2 is a flowchart of a control method for a vehicle braking system according to a specific example of the present application;

[0025] Figure 3 is a block diagram of a vehicle according to an embodiment of the present application;

[0026] Figure 4 is a block diagram of a control device of a vehicle braking system according to an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application, but should not be construed as limiting the present application.

[0028] A control method for a vehicle braking system, a computer-readable storage medium, a vehicle, and a control device of a vehicle braking system proposed by embodiments of the present application will be described below with reference to the accompanying drawings.

[0029] Figure 1 is a flowchart of a control method for a vehicle braking system according to an embodiment of the present application.

[0030] As Figure 1 shown, the control method for a vehicle braking system according to an embodiment of the present application may include the following steps:

[0031] S1, acquire the vehicle weight, acceleration, rolling radius, reference braking efficiency, and braking demand during the current braking of the vehicle.

[0032] S2. Determine the hydraulic pressure of the brake pipeline based on the braking demand.

[0033] S3. Determine the target braking efficiency during this braking based on the vehicle weight, acceleration, rolling radius, and hydraulic pressure.

[0034] S4. Correct the reference braking efficiency based on the target braking efficiency.

[0035] Specifically, during the vehicle driving process, first obtain the vehicle weight, acceleration, rolling radius, reference braking efficiency, and braking demand during this braking. Among them, the vehicle weight is the total mass of the vehicle, including the vehicle's own weight and load. The vehicle weight can be preset through vehicle design parameters or measured in real time by sensors (such as using a weighing sensor). The acceleration in this application refers to the deceleration of the vehicle during the braking process. For example, the deceleration of the vehicle can be measured in real time by the vehicle's acceleration sensor. Deceleration is one of the important indicators of braking efficiency and reflects the actual effect of the braking system. The rolling radius is the radius of the wheel, usually a fixed parameter, which can be obtained from the vehicle's design data. The reference braking efficiency is the initial braking efficiency value stored in the vehicle ECU (Electronic Control Unit), which can be obtained through calibration when the vehicle leaves the factory. It reflects the braking performance of the vehicle under standard working conditions. In addition, in this application, the reference braking efficiency can be corrected, that is, the reference braking efficiency also represents the braking efficiency that has been corrected during the previous vehicle braking. The braking demand refers to the braking force demand applied by the driver through the brake pedal, which can be calculated by the position sensor of the brake pedal or the brake pipeline pressure sensor. The braking demand reflects the degree to which the driver hopes the vehicle slows down.

[0036] After determining the braking demand, the hydraulic pressure of the brake pipeline can be determined according to the braking demand. For example, the hydraulic pressure can be determined through a preset corresponding relationship. For example, the relationship between the braking demand and the hydraulic pressure is determined in advance. After the braking demand is determined, the corresponding relationship can be directly called to obtain the hydraulic pressure. That is, the hydraulic pressure is the pressure of the brake pipeline in the hydraulic braking system, which directly affects the magnitude of the braking force.

[0037] After obtaining the hydraulic pressure, the target braking efficiency during this braking can be determined based on the vehicle weight, acceleration, rolling radius, and hydraulic pressure. The target braking efficiency is the braking efficiency value calculated according to the current braking condition, which reflects the actual braking performance of the vehicle under the current condition and is an important basis for dynamically adjusting the control strategy of the braking system. For example, the target braking efficiency can be calculated through a pre-determined formula. After obtaining the target braking efficiency, the reference braking efficiency can be corrected according to the target braking efficiency. For example, the difference between the target braking efficiency and the reference braking efficiency can be calculated, and then, according to the pre-set correction step, the correction amount can be jointly determined with the difference, so that the correction amount can be added to the reference braking efficiency to obtain the corrected reference braking efficiency. Thus, through the above steps, the braking system of the vehicle can dynamically adjust the braking efficiency according to the actual condition. For example: if the target braking efficiency is higher than the reference braking efficiency, it means that the actual braking performance of the vehicle is better than expected, and the hydraulic pressure can be appropriately reduced. If the target braking efficiency is lower than the reference braking efficiency, it means that the actual braking performance of the vehicle is lower than expected, and the hydraulic pressure needs to be increased or the proportion of regenerative braking needs to be adjusted. This dynamic correction mechanism can adapt to factors such as vehicle wear, load change, and road surface condition change, ensuring that the braking system is always in the best state. For example: when the vehicle load increases, the target braking efficiency will decrease, and the ECU can automatically adjust the hydraulic pressure to ensure the braking effect. When the vehicle load decreases, the target braking efficiency will increase, and the ECU can reduce the hydraulic pressure to avoid over-braking.

[0038] For example, in a hybrid braking system (regenerative braking + hydraulic braking), the target braking efficiency can help optimize the distribution of braking force. For example: during low-speed braking, regenerative braking may not be able to provide sufficient braking force, and hydraulic braking needs to supplement. During high-speed braking, regenerative braking can recover more energy and reduce the use of hydraulic braking. Thus, by obtaining the actual operating parameters of the vehicle (such as vehicle weight, acceleration, rolling radius, braking demand, etc.), calculating the target braking efficiency, and correcting the reference braking efficiency based on the target braking efficiency, dynamic optimization of the braking system can be achieved. This method can not only improve the robustness and safety of the braking system but also optimize the energy recovery efficiency and is applicable to the hybrid braking system and adaptive braking system of modern intelligent vehicles.

[0039] According to an embodiment of the present application, determining the target braking efficiency during this braking based on the vehicle weight, acceleration, rolling radius, and hydraulic pressure includes: determining the target braking efficiency based on the ratio of the product of the vehicle weight, acceleration, and rolling radius to the hydraulic pressure.

[0040] Specifically, the target braking efficiency is a key parameter used to measure the ability of a vehicle to convert braking force into deceleration under specific working conditions. By calculating the target braking efficiency, the control strategy of the braking system can be optimized to ensure the consistency and safety of braking performance. That is, the target braking efficiency is a dimensionless coefficient used to describe the braking performance of a vehicle under the current working conditions. It reflects the relationship between the deceleration that can be achieved by the vehicle under a given hydraulic pressure and vehicle parameters (such as vehicle weight and rolling radius).

[0041] When determining the target braking efficiency during this braking based on vehicle weight, acceleration, rolling radius, and hydraulic pressure, the target braking efficiency can be determined according to the ratio of the product of vehicle weight, acceleration, and rolling radius to the hydraulic pressure. That is, the target braking efficiency = m * a * r / P, where m is the mass of the vehicle (unit: kilogram, kg), a is the acceleration of the vehicle (negative in this application, i.e., deceleration) (unit: meter per second squared, m / s 2 ), r is the rolling radius of the wheel (unit: meter, m), and P is the hydraulic pressure in the brake line (unit: Pascal, Pa). That is, the vehicle weight is the total mass of the vehicle, including the vehicle's own weight and load. The greater the vehicle weight, the greater the braking force required during braking. Therefore, vehicle weight is an important factor affecting braking efficiency. Deceleration is the rate of change of speed during braking, reflecting the intensity of braking. The greater the deceleration, the higher the braking efficiency, but at the same time, a greater braking force is required to achieve it. The rolling radius is the radius of the wheel, which affects the circumference of the wheel and the rolling characteristics of the vehicle. The larger the rolling radius, the larger the circumference of the wheel, and the same braking force can generate a greater deceleration. Hydraulic pressure is the pressure in the brake line of the braking system, which directly reflects the braking force applied by the braking system. The greater the hydraulic pressure, the greater the braking force, but the calculation of braking efficiency needs to consider the actual vehicle parameters (such as vehicle weight and rolling radius) to measure its effectiveness.

[0042] The target braking efficiency provides a benchmark for the control of the braking system. The ECU can adjust the distribution of braking force according to the target braking efficiency to ensure that the performance of the braking system remains consistent under different working conditions. For example: in the coordination of regenerative braking and hydraulic braking, the target braking efficiency can help determine the optimal distribution ratio of the two braking methods. When the vehicle load changes, the target braking efficiency can dynamically adjust the braking pressure to ensure that the braking effect is not affected. The target braking efficiency can also be used as a reference value for self-learning algorithms. By comparing the target braking efficiency and the actual braking efficiency, the ECU can determine whether the braking system needs to adjust parameters. For example: if the actual braking efficiency is lower than the target braking efficiency, it may be due to brake wear or hydraulic system leakage and maintenance is required. If the actual braking efficiency is higher than the target braking efficiency, it may be due to a decrease in vehicle load or an increase in tire grip, and the braking pressure needs to be adjusted.

[0043] Thus, by calculating the ratios of vehicle weight, deceleration, rolling radius, and hydraulic pressure, the control strategy of the braking system can be optimized, and the robustness and safety of the braking system can be improved. It has wide application value in hybrid braking systems, adaptive braking systems, and safety braking systems.

[0044] According to an embodiment of the present application, correcting the reference braking effectiveness based on the target braking effectiveness includes: determining the effectiveness difference between the reference braking effectiveness and the target braking effectiveness; and when the effectiveness difference is greater than a preset difference, correcting the reference braking effectiveness based on the sum of the result of the ratio of the product of the preset step size and the effectiveness difference to the absolute value of the effectiveness difference and the reference braking effectiveness. Herein, the preset difference and the preset step size can be determined according to actual situations.

[0045] Specifically, the process of correcting the reference braking effectiveness based on the target braking effectiveness is a self-learning mechanism for dynamically adjusting the performance of the braking system to ensure the consistency and accuracy of the braking effectiveness. The core of this correction mechanism lies in dynamically adjusting the reference braking effectiveness by calculating the difference between the real-time calculated target braking effectiveness and the stored reference braking effectiveness, thereby optimizing the control strategy of the braking system.

[0046] When correcting the reference braking effectiveness according to the target braking effectiveness, the effectiveness difference between the reference braking effectiveness and the target braking effectiveness can be determined, and a preset difference can be set to judge whether the reference braking effectiveness needs to be corrected. If the effectiveness difference is greater than the preset difference, it indicates that there is a significant difference between the current actual braking effectiveness and the reference braking effectiveness, and the reference braking effectiveness needs to be corrected. If correction is required, calculate the correction amount, that is, the correction amount is the result of the ratio of the product of the preset step size and the effectiveness difference to the absolute value of the effectiveness difference. For example, the correction amount is determined by the formula Cp_step*ΔCp / |ΔCp|, where Cp_step is the preset step size for controlling the correction amplitude, Cp is the effectiveness difference, and Cp / |ΔCp| is the sign (+1 or -1) of the effectiveness difference, indicating the correction direction. When correcting the reference braking effectiveness, the correction amount can be added to the reference braking effectiveness to obtain the corrected reference braking effectiveness.

[0047] Thus, by calculating the difference between the real-time calculated target braking effectiveness and the reference braking effectiveness, the reference braking effectiveness is dynamically adjusted to be closer to the actual braking performance of the vehicle. Through the self-learning mechanism, the braking system can adapt to factors such as vehicle wear, load changes, and road surface condition changes, ensuring the consistency and stability of the braking effectiveness. The corrected reference braking effectiveness can be used as the basis for the braking system control strategy to help more accurately distribute the braking force and improve the coordination of regenerative braking and hydraulic braking.

[0048] According to an embodiment of the present application, a vehicle braking system includes a hydraulic braking system and a regenerative braking system, and the control method of the vehicle braking system further includes: obtaining the road surface adhesion coefficient and the state of charge of the battery of the current road surface; determining a target braking system corresponding to the braking demand based on the road surface adhesion coefficient and the state of charge of the battery, wherein the target braking system includes a hydraulic braking system and a regenerative braking system.

[0049] Specifically, the braking system may include a hydraulic braking system and a regenerative braking system. The goal of this composite braking system is to maximize the energy recovery efficiency while meeting the braking demand, while ensuring the safety and stability of the vehicle. The hydraulic braking system is a traditional braking method. By the driver stepping on the brake pedal, the pedal force is converted into hydraulic pressure and transmitted to the brakes of each wheel, thereby generating braking force. The hydraulic braking system can provide stable braking force under any working condition and is an important guarantee for vehicle safety. The hydraulic braking system is a traditional braking method. By the driver stepping on the brake pedal, the pedal force is converted into hydraulic pressure and transmitted to the brakes of each wheel, thereby generating braking force. The hydraulic braking system can provide stable braking force under any working condition and is an important guarantee for vehicle safety.

[0050] The road surface adhesion coefficient is a parameter that measures the friction force between the road surface and the tire. It directly affects the braking performance of the vehicle. The higher the adhesion coefficient, the greater the friction force between the tire and the road surface, and the better the braking effect; conversely, when the adhesion coefficient is low, the braking effect will decrease significantly. The state of charge (SOC) of the battery refers to the remaining battery charge. During the regenerative braking process, the motor converts the kinetic energy of the vehicle into electrical energy and stores it in the battery. If the battery is fully charged, even if the motor is capable of recovering more energy, this energy cannot be stored in the battery.

[0051] When the target braking system is determined, the road surface adhesion coefficient and the state of charge of the battery of the current road surface can be obtained, and the target braking system corresponding to the braking demand can be determined based on the road surface adhesion coefficient and the state of charge of the battery. For example, the road surface image can be captured by an in-vehicle camera, and image processing and machine learning algorithms can be used to identify the road surface type (such as dry, wet, ice and snow road surfaces). Based on the road surface type, a preset adhesion coefficient range is set. For example, the adhesion coefficient of a dry asphalt road surface is relatively high, and the adhesion coefficient of an ice and snow road surface is relatively low. The remaining power of the battery, that is, the state of charge of the battery, can be calculated by measuring the charge and discharge current of the battery and integrating the current. After obtaining the road surface adhesion coefficient and the state of charge of the battery, the target braking system can be determined according to the preset relationship. For example, in the preset relationship table, multiple road surface adhesion coefficients, battery state of charge, and corresponding hydraulic braking systems and regenerative braking systems are stored. After determining the road surface adhesion coefficient and the battery state of charge, the corresponding braking system can be determined according to the corresponding relationship. For example, when the road surface adhesion coefficient is small, the target braking system is a hydraulic braking system, because a road surface with a low adhesion coefficient (such as an ice and snow road surface) may cause the regenerative braking system to be unable to provide stable braking force, and may even cause wheel lock-up or vehicle out of control. When the road surface adhesion coefficient is large and the state of charge of the battery is moderate, the target braking system can be determined to be a regenerative braking system and a hydraulic braking system, that is, the regenerative braking system and the hydraulic braking system work simultaneously to provide braking force.

[0052] Therefore, the target braking system selection strategy based on the road surface adhesion coefficient and the state of charge of the battery aims to ensure that the braking demand can be met under different working conditions, the energy recovery efficiency can be maximized, and the safety and stability of the vehicle can be guaranteed at the same time.

[0053] According to an embodiment of the present application, determining the target braking system corresponding to the braking demand based on the road surface adhesion coefficient and the state of charge of the battery includes: when the road surface adhesion coefficient is less than the preset adhesion coefficient threshold, determining the target braking system as a hydraulic braking system; when the road surface adhesion coefficient is greater than or equal to the preset adhesion coefficient threshold and the state of charge of the battery is greater than the preset state of charge threshold, determining the target braking system as a hydraulic braking system; when the road surface adhesion coefficient is greater than or equal to the preset adhesion coefficient threshold and the state of charge of the battery is less than or equal to the preset state of charge threshold, determining the target braking system based on the maximum recovery ability of the motor. Among them, the preset adhesion coefficient threshold can be determined according to the actual situation.

[0054] Specifically, the road surface adhesion coefficient is a parameter that measures the frictional force between the road surface and the tire. It directly affects the braking performance of the vehicle. The higher the adhesion coefficient, the greater the frictional force between the tire and the road surface, and the better the braking effect. Conversely, when the adhesion coefficient is low, the braking effect will decrease significantly. Low adhesion coefficient road surfaces (such as ice and snow road surfaces): In this case, regenerative braking may cause the wheels to lock up or lose traction, thereby reducing the stability and safety of the vehicle. High adhesion coefficient road surfaces (such as dry asphalt road surfaces): In this case, regenerative braking can more effectively recover energy while providing stable braking force. The State of Charge (SOC) of the battery refers to the remaining battery charge. During regenerative braking, the motor converts the kinetic energy of the vehicle into electrical energy and stores it in the battery. If the battery is fully charged (high SOC), it cannot accept more energy, and the effect of regenerative braking will be greatly reduced. That is, high SOC: The battery charge is close to or reaches the upper limit, and the regenerative braking system may not be able to effectively recover energy, and may even need to limit the use of regenerative braking. Low SOC: The battery charge is low, and the regenerative braking system can more effectively recover energy while charging the battery.

[0055] When determining the target braking system corresponding to the braking demand according to the road surface adhesion coefficient and the battery state of charge, the magnitudes of the road surface adhesion coefficient and the battery state of charge can be judged. When the road surface adhesion coefficient is less than the preset adhesion coefficient threshold, for example, when the road surface adhesion coefficient is less than 0.8, in this case, regardless of the battery state of charge, it can be determined that the target braking system is a hydraulic braking system. That is, low adhesion coefficient road surfaces (such as ice and snow road surfaces) may cause the regenerative braking system to be unable to provide stable braking force, and may even cause the wheels to lock up or the vehicle to lose control. The hydraulic braking system can more effectively control the braking force on low adhesion coefficient road surfaces, avoid wheel lock-up, and provide a more stable braking effect.

[0056] When the road surface adhesion coefficient is greater than or equal to the preset adhesion coefficient threshold and the battery state of charge is greater than the preset state of charge threshold, for example, the road surface adhesion coefficient is greater than 0.8 and the battery state of charge is greater than 95%, it can be determined that the target braking system is a hydraulic braking system. That is, even if the road surface adhesion coefficient is high, the regenerative braking system cannot effectively recover energy because the battery cannot accept more charge. In this case, the regenerative braking system may be restricted or disabled to avoid energy waste and system overload, while the hydraulic braking system can provide stable braking force and avoid the reduction in efficiency of the regenerative braking system due to battery charge problems.

[0057] When the road surface adhesion coefficient is greater than the preset adhesion coefficient threshold and the state of charge of the battery is less than or equal to the preset state of charge threshold, for example, the road surface adhesion coefficient is greater than 0.8 and the state of charge of the battery is less than 95%, the target braking system can be determined based on the maximum recovery ability of the motor. For example, when the maximum recovery ability of the motor is 0, the target braking system can be determined as a hydraulic braking system. When the maximum recovery ability of the motor is relatively large (such as it can meet the braking demand), the target braking system can be determined as a regenerative braking system, etc.

[0058] Thus, on a low adhesion coefficient road surface, the hydraulic braking system is preferentially used to avoid wheel locking and vehicle out of control. On a high adhesion coefficient road surface, according to the state of charge of the battery and the maximum recovery ability of the motor, the braking force is reasonably distributed, and the regenerative braking system is preferentially used. By comprehensively considering various factors, the efficient operation of the braking system can be achieved, while reducing the wear of the hydraulic braking system and prolonging its service life.

[0059] According to an embodiment of the present application, determining the target braking system based on the maximum recovery ability of the motor includes: when the maximum recovery ability is greater than or equal to the braking demand, determining the target braking system as a regenerative braking system; when the maximum recovery ability is less than the braking demand, determining the target braking system as a regenerative braking system and a hydraulic braking system, where the braking force provided by the regenerative braking system is the maximum recovery ability, and the braking force provided by the hydraulic braking system is the difference between the braking demand and the maximum recovery ability.

[0060] Specifically, when determining the target braking system according to the maximum recovery ability of the motor, the magnitude relationship between the maximum recovery ability and the braking demand is judged. When the maximum recovery ability is greater than or equal to the braking demand, the target braking system can be determined as a regenerative braking system. That is to say, the maximum recovery ability of the motor refers to the maximum braking force that the motor can provide in the regenerative braking mode. This ability depends on the characteristics of the motor, the state of charge (SOC) of the battery, and the operating conditions of the vehicle (such as vehicle speed, deceleration, etc.). The braking demand refers to the braking force demand applied by the driver through the brake pedal. When the maximum recovery ability of the motor is greater than or equal to the braking demand, it means that the regenerative braking system can fully meet the braking demand, and all the braking force is provided by the regenerative braking system, which can reduce the wear of the hydraulic braking system and prolong its service life.

[0061] When the maximum recovery capacity is less than the braking demand, the target braking system can be determined as the regenerative braking system and the hydraulic braking system. That is to say, the regenerative braking system and the hydraulic braking system are used simultaneously. The regenerative braking system provides its maximum recovery capacity, and the hydraulic braking system provides the remaining braking force, which is the difference between the braking demand and the maximum recovery capacity. Thus, even if the regenerative braking ability is insufficient, the hydraulic braking system can ensure that the vehicle can decelerate or stop safely, and the regenerative braking system still recovers as much energy as possible, while the hydraulic braking system supplements the insufficient part to achieve the balance between energy recovery and braking safety. Therefore, when the regenerative braking ability is sufficient, the regenerative braking is preferentially used. When the regenerative braking ability is insufficient, the remaining braking force is supplemented by hydraulic braking. By reasonably distributing the braking force, the wear of the hydraulic braking system can be reduced, its service life can be extended, and at the same time, the efficiency and safety of the entire braking system can be improved.

[0062] According to an embodiment of the present application, the control method of the vehicle braking system further includes: obtaining the vehicle speed; when the vehicle speed is less than a preset vehicle speed threshold, determining the target braking system as the hydraulic braking system. The preset vehicle speed threshold can be determined according to the actual situation.

[0063] Specifically, as the braking force continues to act, the vehicle speed will continuously decrease. When the vehicle is at a low speed, the rotational speed of the motor is low, the power generation efficiency drops significantly, and the mechanical loss of the motor is relatively large at low speeds, resulting in a very low energy recovery efficiency or even an inability to effectively recover energy, that is, the regenerative braking system cannot work. Therefore, the vehicle speed can be obtained. For example, it can be obtained through a vehicle speed sensor, which is usually installed on the wheel or the transmission. The vehicle speed sensor converts the rotational speed of the wheel into an electrical signal and then transmits it to the vehicle's electronic control unit. The electronic control unit calculates the actual driving speed of the vehicle based on these signals.

[0064] The preset vehicle speed threshold is a system design parameter used to define at what vehicle speed the braking mode is switched. This threshold is usually set according to the specific design and safety requirements of the vehicle. For example, this threshold is set at about 10 - 15 km / h. When judging the vehicle speed, when the vehicle speed is lower than the preset vehicle speed threshold, the regenerative braking system will be disabled, and it can be determined that the target braking system is the hydraulic braking system, that is, all the braking force is provided by the hydraulic braking system. That is to say, the hydraulic braking system can provide stable braking force, which is not affected by the vehicle speed and the motor efficiency, and this is crucial for the safety of the vehicle when driving at a low speed or stopping. Thus, the advantages of regenerative braking and hydraulic braking can be balanced, and at the same time, the safety and efficiency of the vehicle under different working conditions can be ensured.

[0065] The following combines Figure 2 to describe the control method of the present application.

[0066] As a specific example, the control method of the vehicle braking system of the present application may include the following steps:

[0067] S101, obtain the vehicle weight, acceleration, rolling radius, reference braking efficiency, and braking demand during the current braking.

[0068] S102, determine whether the road surface adhesion coefficient is greater than or equal to a preset adhesion coefficient. If so, execute step S103; if not, execute step S108.

[0069] S103, determine whether the state of charge of the battery is greater than a preset state of charge threshold. If so, execute step S108; if not, execute step S104.

[0070] S104, determine whether the maximum recovery ability of the motor is greater than or equal to the braking demand. If so, execute step S105; if not, execute step S106.

[0071] S105, determine that the target braking system is the regenerative braking system.

[0072] S106, determine that the target braking system is the regenerative braking system and the hydraulic braking system, where the braking force provided by the regenerative braking system is the maximum recovery ability of the motor, and the braking force provided by the hydraulic braking system is the difference between the braking demand and the maximum recovery ability.

[0073] S107, determine whether the current vehicle speed is less than a preset vehicle speed threshold. If so, execute step S108; if not, execute step S106.

[0074] S108, determine that the target braking system is the hydraulic braking system.

[0075] S109, determine the target braking efficiency based on the ratio of the product of the vehicle weight, acceleration, and rolling radius to the hydraulic pressure.

[0076] S110, determine the efficiency difference between the reference braking efficiency and the target braking efficiency.

[0077] S111, determine whether the efficiency difference is greater than a preset difference. If so, execute step S112; if not, execute step S110.

[0078] S112, correct the reference braking efficiency based on the sum of the reference braking efficiency and the result of the ratio of the product of the preset step size and the efficiency difference to the absolute value of the efficiency difference.

[0079] In summary, according to the control method of the vehicle braking system in the embodiments of the present application, the vehicle weight, acceleration, rolling radius, reference braking efficiency, and braking demand during this braking are obtained. Based on the braking demand, the hydraulic pressure of the brake pipeline is determined. Based on the vehicle weight, acceleration, rolling radius, and hydraulic pressure, the target braking efficiency during this braking is determined. Based on the target braking efficiency, the reference braking efficiency is corrected. Thus, this method can solve the problem of inconsistent braking efficiency and ensure relatively stable braking efficiency of the vehicle.

[0080] Corresponding to the above embodiments, the present application also proposes a computer-readable storage medium.

[0081] The computer-readable storage medium in the embodiments of the present application stores a program thereon, and when the program is executed by a processor, it implements the above control method of the vehicle braking system.

[0082] According to the computer-readable storage medium in the embodiments of the present application, by executing the above control method of the vehicle braking system, the problem of inconsistent braking efficiency can be solved, and relatively stable braking efficiency of the vehicle can be ensured.

[0083] Corresponding to the above embodiments, the present application also proposes a vehicle.

[0084] As Figure 3 shown, the vehicle 200 in the embodiments of the present application may include: a memory 210, a processor 220, and a program stored on the memory 210 and executable on the processor 220. When the processor 220 executes the program, it implements the above control method of the vehicle braking system.

[0085] According to the vehicle in the embodiments of the present application, by executing the above control method of the vehicle braking system, the problem of inconsistent braking efficiency can be solved, and relatively stable braking efficiency of the vehicle can be ensured.

[0086] Corresponding to the above embodiments, the present application also proposes a control device for a vehicle braking system.

[0087] As Figure 4 shown, the control device 100 for the vehicle braking system in the embodiments of the present application includes: an acquisition module 110, a first determination module 120, a second determination module 130, and a correction module 140.

[0088] Among them, the acquisition module 110 is used to acquire the vehicle weight, acceleration, rolling radius, reference braking efficiency, and braking demand during this braking. The first determination module 120 is used to determine the hydraulic pressure of the brake pipeline based on the braking demand. The second determination module 130 is used to determine the target braking efficiency during this braking based on the vehicle weight, the acceleration, the rolling radius, and the hydraulic pressure. The correction module 140 is used to correct the reference braking efficiency based on the target braking efficiency.

[0089] According to an embodiment of the present application, the second determination module 130 determines the target braking efficiency during this braking based on the vehicle weight, acceleration, rolling radius, and hydraulic pressure, and specifically is used for: determining the target braking efficiency based on the ratio of the product of the vehicle weight, acceleration, and rolling radius to the hydraulic pressure.

[0090] According to an embodiment of the present application, the correction module 140 corrects the reference braking efficiency based on the target braking efficiency, and specifically is used for: determining the efficiency difference between the reference braking efficiency and the target braking efficiency; when the efficiency difference is greater than a preset difference, correcting the reference braking efficiency based on the sum of the result of the ratio of the product of the preset step size and the efficiency difference to the absolute value of the efficiency difference and the reference braking efficiency.

[0091] According to an embodiment of the present application, the vehicle braking system includes a hydraulic braking system and a regenerative braking system, and the second determination module 130 is further used for: obtaining the road surface adhesion coefficient and the state of charge of the battery of the current road surface; determining the target braking system corresponding to the braking demand based on the road surface adhesion coefficient and the state of charge of the battery, where the target braking system includes a hydraulic braking system and a regenerative braking system.

[0092] According to an embodiment of the present application, the second determination module 130 determines the target braking system corresponding to the braking demand based on the road surface adhesion coefficient and the state of charge of the battery, and specifically is used for: when the road surface adhesion coefficient is less than a preset adhesion coefficient threshold, determining the target braking system as a hydraulic braking system; when the road surface adhesion coefficient is greater than or equal to the preset adhesion coefficient threshold and the state of charge of the battery is greater than the preset state of charge threshold, determining the target braking system as a hydraulic braking system; when the road surface adhesion coefficient is greater than the preset adhesion coefficient threshold and the state of charge of the battery is less than or equal to the preset state of charge threshold, determining the target braking system based on the maximum recovery ability of the motor.

[0093] According to an embodiment of the present application, the second determination module 130 determines the target braking system based on the maximum recovery ability of the motor, and specifically is used for: when the maximum recovery ability is greater than or equal to the braking demand, determining the target braking system as a regenerative braking system; when the maximum recovery ability is less than the braking demand, determining the target braking system as a regenerative braking system and a hydraulic braking system, where the braking force provided by the regenerative braking system is the maximum recovery ability, and the braking force provided by the hydraulic braking system is the difference between the braking demand and the maximum recovery ability.

[0094] According to an embodiment of the present application, the second determination module 130 is further used for: obtaining the vehicle speed; when the vehicle speed is less than a preset vehicle speed threshold, determining the target braking system as a hydraulic braking system.

[0095] It should be noted that for the details not disclosed in the control device of the vehicle braking system according to the embodiments of the present application, please refer to the details disclosed in the control method of the vehicle braking system according to the embodiments of the present application, and will not be elaborated here specifically.

[0096] According to the control device of the vehicle braking system according to the embodiments of the present application, the acquisition module is used to acquire the vehicle weight, acceleration, rolling radius, reference braking efficiency, and braking demand during the current braking of the vehicle. The first determination module is used to determine the hydraulic pressure of the brake pipeline based on the braking demand. The second determination module is used to determine the target braking efficiency during the current braking based on the vehicle weight, the acceleration, the rolling radius, and the hydraulic pressure. The correction module is used to correct the reference braking efficiency based on the target braking efficiency. Thus, the device can solve the problem of inconsistent braking efficiency and ensure relatively stable braking efficiency of the vehicle.

[0097] It should be noted that the logic and / or steps represented in the flowchart or described in other ways herein, for example, can be considered as a predefined sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or in combination with these instruction execution systems, apparatus, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation, or other appropriate processing as necessary, and then stored in a computer memory.

[0098] It should be understood that each part of the present application can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0099] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0100] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0101] In the present application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0102] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A method for controlling a vehicle braking system, characterized in that: The method comprises: Obtaining the vehicle weight, acceleration, rolling radius, baseline braking performance and braking demand during this braking of the vehicle; determining a hydraulic pressure of a brake line based on the braking demand; determining a target braking efficiency during this braking operation based on the vehicle weight, the acceleration, the rolling radius and the hydraulic pressure; The reference braking effectiveness is corrected based on the target braking effectiveness.

2. The control method of the vehicle braking system according to claim 1, characterized in that: The determining the target braking efficiency during the current braking based on the vehicle weight, the acceleration, the rolling radius and the hydraulic pressure includes: The target braking effectiveness is determined based on a ratio of a product of the vehicle weight, the acceleration, the rolling radius, and the hydraulic pressure.

3. The control method of the vehicle braking system according to claim 1, characterized in that: The correcting the reference braking efficiency based on the target braking efficiency includes: determining a performance difference between the reference braking performance and the target braking performance; When the efficiency difference is greater than a preset difference, the reference braking efficiency is corrected based on the sum of a product of a preset step length and the efficiency difference and a ratio of an absolute value of the efficiency difference and the reference braking efficiency.

4. The control method of the vehicle braking system according to claim 1, characterized in that: The vehicle braking system includes a hydraulic braking system and a regenerative braking system, and the method further includes: Obtain the road adhesion coefficient and battery charge state of the current road surface; A target braking system corresponding to the braking demand is determined based on the road adhesion coefficient and the battery state of charge, wherein the target braking system includes the hydraulic braking system and the regenerative braking system.

5. The control method of the vehicle braking system according to claim 4, characterized in that: The determining, based on the road adhesion coefficient and the battery state of charge, of a target braking system corresponding to the braking demand comprises: When the road adhesion coefficient is less than a preset adhesion coefficient threshold, determining that the target braking system is the hydraulic braking system; When the road adhesion coefficient is greater than or equal to the preset adhesion coefficient threshold and the battery state of charge is greater than a preset state of charge threshold, determining that the target braking system is the hydraulic braking system; When the road adhesion coefficient is greater than the preset adhesion coefficient threshold and the battery state of charge is less than or equal to the preset state of charge threshold, the target braking system is determined based on the maximum recovery capacity of the motor.

6. The control method of the vehicle braking system according to claim 5, characterized in that: The step of determining the target braking system based on the maximum recovery capability of the motor includes: When the maximum recovery capacity is greater than or equal to the braking demand, determining that the target braking system is the regenerative braking system; When the maximum recovery capacity is less than the braking demand, the target braking system is determined to be the regenerative braking system and the hydraulic braking system, wherein the braking force provided by the regenerative braking system is the maximum recovery capacity, and the braking force provided by the hydraulic braking system is the difference between the braking demand and the maximum recovery capacity.

7. The control method of the vehicle braking system according to claim 6, characterized in that: The method further comprises: Obtaining the speed of the vehicle; When the vehicle speed is less than a preset vehicle speed threshold, it is determined that the target braking system is a hydraulic braking system.

8. A computer-readable storage medium, characterized in that: A program is stored thereon, and when the program is executed by a processor, a control method for a vehicle braking system according to any one of claims 1 to 7 is implemented.

9. A vehicle, characterized in that: include: A memory, a processor, and a program stored in the memory and executable on the processor, wherein when the processor executes the program, a method for controlling a vehicle braking system according to any one of claims 1 to 7 is implemented.

10. A control device for a vehicle braking system, characterized in that: The device comprises: An acquisition module, used to acquire the vehicle weight, acceleration, rolling radius, reference braking performance and braking demand during current braking of the vehicle; a first determination module, configured to determine a hydraulic pressure of a brake line based on the braking demand; A second determination module, configured to determine a target braking efficiency during current braking based on the vehicle weight, the acceleration, the rolling radius and the hydraulic pressure; A correction module is used to correct the reference braking efficiency based on the target braking efficiency.

Images