Brake control method and device, storage medium, controller and vehicle

Abstract

The invention relates to a braking control method and device, a storage medium, a controller and a vehicle. In the technical scheme, when braking parameters meet the first condition, braking control is conducted through regenerative braking, and by means of software optimization of a braking system, the braking parameters of the braking system are optimized according to the stroke parameters and the hydraulic pressure condition; according to the scheme of regenerative braking, accurate adjustment of braking is achieved, so that unnecessary resonance influence is avoided, and braking noise is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of brake control, and in particular to a brake control method, device, storage medium, controller, and vehicle. Background Art

[0002] With the rapid development of new energy vehicles, the braking noise of the whole vehicle is easier for customers to perceive than that of fuel vehicles, so consumers have higher and higher requirements for braking noise.

[0003] At present, the problem is generally solved by optimizing the hardware structure itself, such as optimizing the friction plate formula, silencer and brake disc structure, as well as changing the structure and material of related components of the suspension system. Through the optimization of hardware solutions and multiple rounds of bench tests and actual vehicle verification, it is still impossible to reduce brake noise. Summary of the invention

[0004] The embodiment of the present application provides a braking control method, which starts regenerative braking to perform braking control and effectively reduces the braking noise generated by hydraulic braking through software control.

[0005] In order to achieve the above-mentioned purpose, according to a first aspect of the present application, a braking control method is provided, comprising: when a braking parameter satisfies a first condition, performing braking control through feedback braking.

[0006] Optionally, the braking parameters include: a travel parameter of a braking device and a hydraulic pressure of a hydraulic brake;

[0007] During the regenerative braking, the hydraulic pressure is 0.

[0008] Optionally, the method further comprises:

[0009] The first condition is determined according to a calibrated first stroke pressure relationship; wherein the first stroke pressure relationship is a pre-calibrated association relationship between a first stroke interval and a first hydraulic interval.

[0010] Optionally, the method further comprises:

[0011] When the stroke parameter of the brake device satisfies the first stroke range, and the hydraulic pressure of the hydraulic brake satisfies the first hydraulic range, performing braking control through feedback braking;

[0012] The first stroke interval and the first hydraulic interval are when the braking noise exceeds a noise threshold during vehicle braking.

[0013] Optionally, the method further comprises:

[0014] When the vehicle speed is less than the vehicle speed threshold, and the travel parameter of the brake device and the hydraulic pressure of the hydraulic brake meet the second condition, performing braking control through feedback braking;

[0015] The vehicle speed threshold is the maximum vehicle speed when the vehicle has braking noise.

[0016] Optionally, the method further comprises:

[0017] When the braking time of the vehicle is greater than the time threshold, and the stroke parameter of the braking device and the hydraulic pressure of the hydraulic brake meet the second condition, performing braking control through feedback braking;

[0018] The duration threshold is the minimum duration for the vehicle to generate braking noise.

[0019] Optionally, the method further comprises:

[0020] The second condition is determined according to a calibrated second stroke pressure relationship; wherein the second stroke pressure relationship is a pre-calibrated association relationship between a second stroke interval and a second hydraulic interval.

[0021] Optionally, the method further comprises:

[0022] When the stroke parameter of the braking device satisfies the second stroke range and the hydraulic pressure of the hydraulic brake satisfies the second hydraulic range, braking control is performed through feedback braking; wherein, the second stroke range and the second hydraulic range are when the braking noise exceeds the noise threshold during low-speed braking of the vehicle.

[0023] Optionally, the method further comprises:

[0024] During the stroke-pressure relationship calibration process, the sound frequency is less than or equal to the noise frequency and greater than or equal to the noise threshold.

[0025] Optionally, the method further comprises:

[0026] During the braking process of the vehicle, the vehicle speed gradually decreases at a first change rate, and the travel parameter of the braking device in the vehicle gradually increases at a second change rate.

[0027] Optionally, the braking process of the vehicle includes at least two braking time intervals, wherein the rate of change of the hydraulic pressure in each time interval is different; and the rate of change of the feedback torque corresponding to the feedback braking in each time interval is different.

[0028] Optionally, the braking process of the vehicle includes:

[0029] In the first time interval T1, the hydraulic pressure gradually increases from 0 to the hydraulic interval at a third change rate, and the hydraulic interval includes the first hydraulic interval or the second hydraulic interval;

[0030] In a second time interval T2, the hydraulic pressure gradually decreases from the first pressure value to 0 at a fourth change rate;

[0031] In the third time interval T3, the hydraulic pressure is maintained at 0;

[0032] In a fourth time interval T4, the hydraulic pressure gradually increases to a second pressure value at a fifth change rate;

[0033] In the fifth time interval T5, the hydraulic pressure gradually increases to a third pressure value at a sixth change rate.

[0034] Optionally, the first time interval T1, the second time interval T2, the third time interval T3, the fourth time interval T4 and the fifth time interval T5 are consecutive intervals in sequence, and the first pressure value is smaller than the second pressure value and smaller than the third pressure value.

[0035] Optionally, the braking process of the vehicle includes:

[0036] In the first time interval T1, the feedback torque of the vehicle feedback braking is 0;

[0037] In the second time interval T2, the feedback torque gradually increases from 0 to the first torque value according to a seventh change rate;

[0038] In the third time interval T3, the feedback torque gradually increases from the first torque value to the second torque value at an eighth change rate;

[0039] In the fourth time interval T4, the feedback torque gradually decreases from the second torque value to 0 at a ninth change rate;

[0040] Wherein, the first torque value is smaller than the second torque value.

[0041] Optionally, the seventh change rate is greater than the eighth change rate, and an absolute value of the ninth change rate is greater than an absolute value of the eighth change rate.

[0042] Optionally, the braking device comprises a brake pedal of the vehicle and / or a brake push rod in a brake master cylinder in the vehicle;

[0043] The stroke parameters include: pedal stroke and / or push rod stroke.

[0044] Optionally, when the braking parameter does not satisfy the first condition, or the braking parameter does not satisfy the second condition, braking control is performed through an intelligent braking integrated control system.

[0045] Optionally, during the braking control, the braking noise does not exceed a noise threshold.

[0046] Optionally, the noise threshold is 60 decibels.

[0047] According to a second aspect of the present application, a brake control device is provided, comprising:

[0048] The adjustment module is used to perform braking control through feedback braking when the braking parameter meets the first condition.

[0049] According to a third aspect of the present application, a computer-readable storage medium is also provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0050] According to a fourth aspect of the present application, a controller is also provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0051] According to a fifth aspect of the present application, a vehicle is also provided, comprising at least one of the above-mentioned braking control device, the above-mentioned computer-readable storage medium, and the above-mentioned controller.

[0052] According to a sixth aspect of the present application, a computer program product is also provided, comprising a computer program or instructions, which implement the steps of the above method when executed by a processor.

[0053] To summarize, in the embodiment of the present application, the feedback braking is started to perform braking control according to the stroke parameters of the braking device and the hydraulic pressure of the hydraulic brake. Through the above-mentioned technical solution, the software of the braking system is optimized, and the feedback braking solution is used to achieve precise adjustment of the braking according to the stroke parameters and the hydraulic pressure, so as to avoid unnecessary resonance effects and reduce braking noise.

[0054] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0056] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings, wherein the same figure numbers represent the same parts in the following description.

[0057] Figure 1 This is a schematic diagram of a related technology of a braking control method provided in an exemplary embodiment of the present application. Figure 1 ;

[0058] Figure 2 This is a schematic diagram of a related technology of a braking control method provided in an exemplary embodiment of the present application. Figure 2 ;

[0059] Figure 3 is a flowchart of a braking control method provided in an exemplary embodiment of the present application;

[0060] Figure 4 This is a schematic diagram of the travel pressure relationship in a brake control method provided in an exemplary embodiment of the present application. Figure 1 ;

[0061] Figure 5 This is a schematic diagram of the travel pressure relationship in a brake control method provided in an exemplary embodiment of the present application. Figure 2 ;

[0062] Figure 6 This is a schematic diagram of the travel pressure relationship in a brake control method provided in an exemplary embodiment of the present application. Figure 3 ;

[0063] Figure 7 is a schematic diagram of a scenario flow in a braking control method provided in an exemplary embodiment of the present application;

[0064] Figure 8 is another scenario flow diagram of a braking control method provided in an exemplary embodiment of the present application;

[0065] Fig. 9 is a schematic diagram of a change trend of brake-related parameters in a brake control method provided in an exemplary embodiment of the present application;

[0066] Fig.10 Schematic diagram of the architecture of a vehicle provided in an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0067] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0068] Based on the problems mentioned in the above background technology, in the relevant technology, with the rapid development of new energy vehicles, the braking noise of the whole vehicle is easier to be perceived by customers than that of fuel vehicles, so consumers have put forward higher and higher requirements for braking noise. Braking noise is mainly divided into the following two types according to the frequency of occurrence: low-frequency noise is between 200 and 1000Hz; medium and high-frequency scream is between 1000 and 16000Hz; low-frequency noise is mainly caused by the system vibration caused by the resonance of the braking system components and the suspension system components, and medium and high-frequency noise is mainly caused by the scream caused by the self-excited vibration of the braking system such as friction plates, brake discs and calipers.

[0069] Regardless of the type of noise, the relevant technology is generally solved by optimizing the hardware structure itself, such as optimizing the friction plate formula, improving the silencer and brake disc structure, and changing the structure and material of related components of the suspension system. It is rather troublesome to solve the brake noise by optimizing the hardware structure.

[0070] Reference Figure 1 and Figure 2 In the related technologies, the typical technical solutions for the problem of vehicle brake noise are as follows: (1) chamfering the friction plate interface to solve the problem of local stress concentration and optimize the motion coupling of the disc, thereby effectively suppressing noise; (2) slotting the friction plate to change the natural vibration frequency of the brake plate to avoid resonance and reduce the occurrence of brake noise; (3) adding a cover plate and a silencer to the friction plate. The cover plate serves as an additional sound insulation and buffer layer, which can effectively block the transmission path of noise and reduce the intensity and propagation range of noise. The combination of silencer and cover plate can change the resonance frequency of the brake system and avoid resonance and amplification of noise at specific frequencies.

[0071] Through the optimization of the disc hardware solution and multiple rounds of bench testing and real vehicle verification, the occurrence of brake noise (also known as brake abnormal noise) has never been completely solved. In addition, the test and verification cycle of the hardware solution optimization is long, and the change cost is high. At the same time, since the structural design of the hardware is relatively fixed, it is difficult to adapt to all fault conditions. Once the hardware is installed on the vehicle and noise occurs in other working conditions, frequent changes will greatly increase the cost and complexity.

[0072] With the continuous popularization and development of new energy vehicles, consumers' requirements for vehicle performance and comfort are also constantly improving. Among the many factors that affect vehicle comfort, noise and vibration (NVH) have become the focus of general concern, especially during vehicle driving. The abnormal noise problem caused by the braking system has become one of the most unacceptable factors for drivers. Among them, NVH refers to noise (Noise), vibration (Vibration) and sound roughness (Harshness), which is a comprehensive issue to measure the quality of automobile manufacturing. NVH performance directly affects the user's riding experience and comfort, and is an important indicator in automobile design and manufacturing.

[0073] Braking noise not only affects the driving experience, but may also have a negative impact on the brand's reputation and market competitiveness. The technical solution of this application summarizes various types of braking conditions. Braking noise often occurs when the vehicle starts. Under low braking pressure, due to the unstable contact of the brake disc, the mode of the brake pad will gradually increase, and it is easy to produce multi-order resonance with the brake disc, resulting in harsh braking noise. At this time, the vehicle is usually in a low-speed driving or stopped state, but once a "creaking" sound, vibration or other abnormal sound occurs under slight braking, it will immediately have a negative impact on the driver's mood. Since the abnormal braking sound is directly related to the normality and reliability of the braking system, many drivers will question the safety of the vehicle, which will affect their purchasing decisions and brand loyalty.

[0074] Therefore, solving the problem of abnormal noise generated when new energy vehicles start has become an urgent need of the industry. This application proposes a solution for braking control in specific situations of braking noise, aiming to effectively reduce the probability of abnormal noise under continuous braking, improve the NVH performance of the vehicle, and allow the driver to enjoy a quieter and more comfortable driving experience.

[0075] The main reason for the abnormal noise caused by braking is the resonance between the braking system, suspension system, steering system and body structure. The resonance between the brake discs is the main reason for the abnormal noise. The dynamic characteristics of the braking system determine the existence of the resonance frequency. When the frequency of wheel rotation matches a certain natural frequency of the braking system, resonance may be induced, resulting in noise amplification. In the current braking control strategy, when the vehicle speed is lower than a certain threshold, the system will switch to relying entirely on hydraulic braking to provide the required braking force, and the regenerative braking function will be disabled.

[0076] The main reason for abnormal brake noise is the vibration between the brake system, suspension system, steering system and body structure. Among them, the stick-slip vibration between the brake discs is the main reason for the abnormal noise. As a typical non-smooth vibration, stick-slip vibration is mainly caused by the "movement-stationary-movement-stationary" friction phenomenon caused by the different values ​​of the dynamic and static friction coefficients of the friction interface. Stick-slip vibration is widely present in various mechanical systems containing friction pairs, especially under conditions of low relative sliding speed and high external load. At the moment of dynamic-static conversion, since the static friction is greater than the dynamic friction, the change in acceleration causes impact vibration, which will produce noise. When this process occurs repeatedly (stationary and moving repeatedly), stick-slip and continuous noise will occur.

[0077] In the process of stick-slip vibration, the dynamic friction coefficient decreases with the increase of relative speed. The variation trend of the friction coefficient with speed is shown in formula (1):

[0078]

[0079] Where μ k is the dynamic friction coefficient; μ s is the static friction coefficient; α is the exponential decay factor of the Stribeck friction model; v r is the speed. Therefore, the friction force also changes with the speed, and its changing trend is shown in formula (2):

[0080] F(v)=sign(v)μ(v)N (2)

[0081] Where F is friction, N is hydraulic pressure, and v is velocity. Combining Newton's second law, the mathematical expression of this physical model can be obtained (3):

[0082]

[0083] By solving and analyzing the above model, we can systematically study the influence of key parameters such as hydraulic pressure, movement speed and system stiffness on the stick-slip vibration effect. The research results show that when the system parameters meet the conditions described by formula (4), the system damping characteristics present a negative value. Under the negative damping state, external energy input will cause the system vibration amplitude to gradually increase, thereby inducing self-excited vibration. This self-excited vibration will further aggravate the dynamic instability of the system and couple with the natural frequency of the system under certain conditions to form a resonance effect. Under the resonance state, the system vibration energy is significantly amplified, and finally manifests as strong mechanical vibration and noise, that is, abnormal sound phenomenon. This process reveals the intrinsic relationship between stick-slip vibration and system parameters, and provides a theoretical basis for suppressing vibration and noise.

[0084]

[0085] Through the theoretical analysis and numerical calculation of the above formula, it can be concluded that when the hydraulic pressure is within the interval (b1, b2) (such as Figure 4 As shown), (b1, b2) corresponds to the hydraulic pressure range with negative damping, calculated according to the formula. In addition, the horizontal axis push rod strokes corresponding to b1 and b2 are a1 and a2 respectively, and the push rod strokes are not limited. Since the system is prone to stick-slip vibration, it induces the problem of abnormal braking noise. This phenomenon is mainly attributed to the unstable dynamic characteristics of the friction pair in this pressure range, which leads to an imbalance between energy input and dissipation. To address this problem, the existing control strategy adopts a dynamic adjustment mechanism based on the vehicle speed threshold: when the vehicle speed is lower than the threshold, the system switches the braking mode to a pure hydraulic braking mode. At the same time, the system temporarily disables the feedback braking function.

[0086] This application proposes a software-based braking control method, including starting regenerative braking for braking control according to the travel parameters of the braking device and the hydraulic pressure of the hydraulic brake, and solving the problem of braking noise under low braking pressure by optimizing the software strategy of the coordinated cooperation between the intelligent integrated braking system and the vehicle power controller. This application can cover the problem of braking noise generated under different braking pressure conditions, and at the same time has more advantages in terms of update iteration rate, cost and design complexity.

[0087] This application provides a method for braking control. Figure 3 The braking control method provided in the embodiment of the present application includes step 100, which is described in detail below.

[0088] Step 100: When the braking parameter meets the first condition, braking control is performed through feedback braking.

[0089] The braking control method in the embodiment of the present application is applied to a vehicle, and the vehicle is provided with at least one of a controller, a braking control device, a computer-readable storage medium and a computer program product.

[0090] The braking parameters include: the travel parameters of the braking device and the hydraulic pressure of the hydraulic brake;

[0091] During the regenerative braking, the hydraulic pressure is 0.

[0092] The vehicle in the implementation of the present application obtains the travel parameters of the brake device, wherein the brake device refers to a device related to brake control, and the brake device in the embodiment of the present application includes a brake pedal and / or a brake push rod in the vehicle, wherein,

[0093] The brake pedal is a key component of the vehicle's braking system. The driver controls the vehicle's deceleration and stopping by stepping on the brake pedal. The brake pedal is used to transmit braking force: the brake pedal converts the braking force applied by the driver into hydraulic pressure through the brake push rod in the brake master cylinder, which then acts on the brake and controls the vehicle's speed: by adjusting the pedal force, the driver can accurately control the degree of deceleration of the vehicle.

[0094] The brake push rod connects the brake pedal and the master cylinder piston. When the driver steps on the brake pedal, the brake push rod transmits this force to the master cylinder piston, thereby pushing the brake fluid into the brake line and generating hydraulic pressure. The brake push rod plays a key role in the braking process. The brake push rod is used to transmit force: the main function of the brake push rod is to transmit the mechanical force generated when the driver steps on the brake pedal to the brake master cylinder, thereby generating hydraulic pressure; the brake push rod is also used for force conversion: through the movement of the push rod, the linear force is converted into the pressure required by the hydraulic system.

[0095] The travel parameters of the brake device in the embodiment of the present application include: the pedal travel of the brake pedal and / or the push rod travel of the brake push rod. The pedal travel of the brake pedal and the push rod travel of the brake push rod in the embodiment of the present application are associated with each other. The pedal travel of the brake pedal refers to the distance the pedal moves when the driver steps on the brake pedal, and the push rod travel refers to the distance the brake push rod in the master cylinder moves during the braking process. The relationship between the two is affected by multiple factors, including:

[0096] Lever ratio: The brake pedal is usually connected to the brake pushrod by a lever mechanism. The leverage ratio affects the proportional relationship between pedal travel and pushrod travel.

[0097] Brake system design: Different brake system designs may result in different travel relationships. For example, a vacuum booster or an electronic booster system may change the relationship between pedal travel and push rod travel.

[0098] Wear and Adjustment: As the brake system wears, pedal travel may change. In addition, the adjustment of the brake system will also affect the travel relationship.

[0099] Since the brake pedal stroke and push rod stroke are related, the specific stroke parameters need to be determined based on the vehicle's braking system design and status. It can be understood that the pedal stroke of the brake pedal and / or the push rod stroke of the brake push rod are used to characterize the user's braking demand for vehicle control. The relative relationship between the pedal stroke of the brake pedal and / or the push rod stroke of the brake push rod is not limited in the embodiments of the present application.

[0100] The vehicle obtains hydraulic pressure from hydraulic brakes, where the hydraulic brake system uses the incompressibility of brake fluid in a closed system to transmit the force of the brake pedal to the brake. When the driver steps on the brake pedal, the brake push rod in the master cylinder guides the piston to push the brake fluid, and the pressure is transmitted to the brake calipers or brake drums of each wheel through the brake pipes.

[0101] In the embodiment of the present application, the vehicle starts feedback braking to control the brake according to the travel parameters of the brake device and the hydraulic pressure of the hydraulic brake. Feedback braking is a technology that uses a feedback control system to adjust and control the braking process. Its basic principle is to monitor the state of the braking system (such as speed, temperature, pressure, etc.) in real time through sensors, and feed this information back to the controller. The controller compares and calculates the braking target and real-time data, and adjusts the brake force to achieve the best braking effect.

[0102] That is, in the embodiment of the present application, regenerative braking is started to perform braking control based on the stroke parameters of the braking device and the hydraulic pressure of the hydraulic brake. In this way, precise adjustment of the braking pressure can be achieved through software optimization of the existing braking system. This strategy will consider maintaining continuous participation of regenerative braking under low braking demand, and dynamically adjust the participation mode and timing of hydraulic braking to avoid unnecessary resonance effects, while ensuring the reliability of braking performance.

[0103] In the embodiment of the present application, during the braking control process, the braking noise does not exceed the noise threshold, that is, without changing the hardware and only with the software strategy, the braking noise of the technical solution of the present application can be kept below 60 decibels.

[0104] Specifically, in the embodiment of the present application, the travel parameters of the braking device are compared with the pre-calibrated travel range, and the hydraulic pressure of the brake hydraulics is compared with the pre-calibrated hydraulic range to adjust the braking strategy of the vehicle.

[0105] The travel range refers to the process of recording the travel parameters of the vehicle's braking device from the presence of braking noise to the disappearance of braking noise. For example, when the vehicle has braking noise, the travel of the brake pedal is recorded as a1 mm (millimeter). The travel of the brake pedal increases until the travel of the brake pedal is a2 mm (millimeter). When the vehicle's braking noise disappears, the travel range is a1mm-a2mm.

[0106] The hydraulic interval refers to the hydraulic pressure of the vehicle's hydraulic brake recorded during the process from the presence of braking noise to the disappearance of the braking noise. For example, when the vehicle has braking noise, the hydraulic pressure is recorded as b1 bar. The hydraulic pressure increases until the hydraulic pressure reaches b2 bar, and the vehicle's braking noise disappears. In this embodiment of the application, the stroke interval of a1 mm-a2 mm corresponding to the hydraulic pressure of b1 bar-b2 bar can be replaced by a hydraulic interval of 0 bar.

[0107] It can be understood that the travel range and the hydraulic range in the embodiment of the present application are calibrated correlation relationships when the vehicle has braking noise, and the specific numerical values ​​given in the embodiment of the present application do not constitute a limitation on the technical solution of the present application.

[0108] When the travel parameter of the brake device matches the pre-calibrated travel range, and the hydraulic pressure of the brake hydraulic pressure matches the hydraulic range, regenerative braking is started to perform brake control.

[0109] Among them, the matching of the stroke parameter of the braking device with the pre-calibrated stroke interval includes: in the case of only one stroke interval, the matching of the stroke parameter with the stroke interval is divided into two cases, case 1, the stroke parameter of the braking device is less than the stroke interval, and case 2, the difference between the stroke parameter of the braking device and the stroke interval does not exceed the error value, and it is determined that the stroke parameter of the braking device matches the pre-calibrated stroke interval; or, in the case of two stroke intervals, the stroke parameter of the braking device is within the stroke parameter interval composed of the two stroke intervals, and it is determined that the stroke parameter of the braking device matches the pre-calibrated stroke interval; or, if there are multiple stroke intervals, the stroke intervals are aggregated to obtain a stroke parameter interval, and the stroke parameter of the braking device is within the stroke parameter interval, and it is determined that the stroke parameter of the braking device matches the pre-calibrated stroke interval.

[0110] The matching of the hydraulic pressure and hydraulic range of the brake hydraulics includes: when there is only one hydraulic range, the difference between the hydraulic pressure and the hydraulic range does not exceed the error range, and the hydraulic pressure and hydraulic range of the brake hydraulics are determined to match; or, when there are two hydraulic ranges, the hydraulic pressure of the brake hydraulics is within the hydraulic pressure range composed of the two hydraulic ranges, and the hydraulic pressure and hydraulic range of the brake hydraulics are determined to match; or, if there are multiple hydraulic ranges, the hydraulic ranges are aggregated to obtain multiple hydraulic pressure ranges, and the hydraulic pressure of the brake hydraulics is within the hydraulic pressure range, and the hydraulic pressure and hydraulic range of the brake hydraulics are determined to match.

[0111] In the embodiment of the present application, regenerative braking is activated for brake control. The core idea is to avoid the pressure range where abnormal noise is generated by replacing hydraulic braking with regenerative braking, which is applicable to any pressure range that may produce abnormal braking noise. In this application scenario, if the regenerative braking force is insufficient, the system can automatically adjust the intervention of hydraulic braking to effectively reduce the contact pressure between the brake disc and the friction plate. This unique design significantly reduces the impact of nonlinear friction and effectively reduces the probability of resonance.

[0112] In the embodiment of the present application, the stroke-pressure relationship is pre-calibrated, that is, when there is braking noise in the vehicle, the stroke parameter of the braking device and the hydraulic pressure of the hydraulic brake are calibrated to obtain the stroke-pressure relationship.

[0113] For example, refer to Figure 4 , Figure 4 This is one of the schematic diagrams of the travel-pressure relationship scenario given by the brake control method in the embodiment of the present application. Figure 4 The graph in the figure is a curve corresponding to the push rod stroke and hydraulic pressure of the vehicle brake push rod recorded during the vehicle braking process. Figure 4 When the push rod stroke of the brake push rod is in the range of a1 mm-a2 mm and the hydraulic pressure is in the range of b1 bar-b2 bar, the natural frequency of the brake system tends to overlap with the rotation frequency under the working conditions of low speed and continuous braking. This frequency overlap will cause resonance between the friction disc and the friction plate, which will cause the generation of brake noise. Figure 4 The curve relationship sets the travel range to a1 mm-a2 mm.

[0114] In the present application embodiment Figure 4 It is an implementation method of braking control based on the existing braking characteristic curve. In the embodiment of the present application, the travel interval and hydraulic interval corresponding to the braking noise are marked on the existing braking characteristic curve; Figure 4 According to the stroke parameters of the brake device and the real-time hydraulic pressure of the hydraulic brake, they are compared with the stroke range and hydraulic range calibrated by the brake curve. In this way, the hydraulic pressure is adjusted through feedback braking to reduce the brake noise caused by the inability of hydraulic brake to accurately control the hydraulic pressure.

[0115] Reference Figure 4 , Figure 4 The stroke pressure relationship in the figure is the correlation diagram between the stroke range and the hydraulic range when the brake noise is generated. Figure 4The stroke interval is positively correlated with the hydraulic interval. When it is determined that the stroke parameter of the braking device during the vehicle braking process matches the stroke interval in the stroke-pressure relationship, and the hydraulic pressure of the hydraulic brake during the vehicle braking process matches the hydraulic interval in the stroke-pressure relationship, the feedback braking mechanism is started to replace the hydraulic braking mode until the stroke parameter of the braking device during the vehicle braking process does not match the stroke interval in the stroke-pressure relationship, or the hydraulic pressure of the hydraulic brake during the vehicle braking process does not match the hydraulic interval in the stroke-pressure relationship.

[0116] In the embodiment of the present application, the first condition is determined according to a calibrated first stroke pressure relationship; wherein, the first stroke pressure relationship is an association relationship between a pre-calibrated first stroke interval and a first hydraulic interval, wherein, the first stroke interval and the first hydraulic interval are when the braking noise exceeds the noise threshold during vehicle braking, the first stroke interval is not specifically limited, and the first stroke interval is pre-calibrated according to the vehicle model, etc.; the first hydraulic interval is not specifically limited, and the first stroke interval is pre-calibrated according to the vehicle model, etc.

[0117] When the stroke parameter of the brake device satisfies the first stroke range, and the hydraulic pressure of the hydraulic brake satisfies the first hydraulic range, braking control is performed through feedback braking.

[0118] For example, refer to Figure 5 , Figure 5 This is the second schematic diagram of the travel pressure relationship scenario provided by the brake control method in the embodiment of the present application. Figure 5 The core idea is to replace hydraulic braking with regenerative braking to avoid the pressure range where abnormal noise is generated, and it is applicable to any pressure range that may produce abnormal braking noise. In this application scenario, if the regenerative braking force is insufficient, the system can automatically adjust the intervention of hydraulic braking to effectively reduce the contact pressure between the brake disc and the friction plate. This unique design significantly reduces the impact of nonlinear friction and effectively reduces the probability of resonance.

[0119] Figure 5 The travel intervals corresponding to the travel intervals from when the braking noise is generated to when the braking noise disappears during the braking process of the vehicle are recorded as a2, a3, a4, a5, a6 and a7, respectively. For example, a2 to a3 corresponds to the push rod travel interval 1; a4 to a5 corresponds to the push rod travel interval 2; a6 to a7 corresponds to the push rod travel interval 3; at the same time, the vehicle uses feedback braking instead of hydraulic braking, and the hydraulic interval is 0. In the embodiment of the present application, the first travel interval includes at least one of the push rod travel interval 1, the push rod travel interval 2, and the push rod travel interval 3.

[0120] The first hydraulic interval is the hydraulic interval corresponding to the first stroke interval, recording the hydraulic interval one b2 to b3 corresponding to the push rod stroke interval one from a2 to a3; the hydraulic interval two b4 to b5 corresponding to the push rod stroke interval two from a4 to a5; and the hydraulic interval three b5 to b6 corresponding to the push rod stroke interval three from a6 to a7. In the embodiment of the present application, the first hydraulic interval includes at least one of hydraulic interval one, hydraulic interval two, and hydraulic interval three.

[0121] In the present application embodiment Figure 5 is an improved braking characteristic curve. In the embodiment of the present application, the travel interval from when the braking noise is generated to when the braking noise disappears is recorded, and the hydraulic interval corresponding to the travel interval is set to zero. Figure 5 According to the stroke parameters of the brake device and the real-time hydraulic pressure of the hydraulic brake, they are compared with the stroke range and target hydraulic range calibrated by the brake curve. In this way, feedback braking adjustment is started when the hydraulic pressure of the hydraulic brake is 0, and the braking noise caused by inaccurate hydraulic braking is avoided through feedback adjustment.

[0122] Reference Figure 5 , Figure 5 The stroke pressure relationship in the diagram is the stroke interval recorded when the brake noise is generated, and the hydraulic interval collected when the brake noise disappears through feedback braking adjustment. The correlation diagram between the stroke interval and the hydraulic interval is established. Figure 5 The stroke parameters in the process are divided into two categories. The first type of stroke parameters are positively correlated with the hydraulic range, and the second type of stroke parameters, that is, the hydraulic range corresponding to the stroke range is zero; when determining that the stroke parameters of the braking device during vehicle braking are matched with the stroke range in the stroke pressure relationship, and the hydraulic pressure of the hydraulic brake during vehicle braking is zero, the feedback braking mechanism is started to replace the hydraulic braking mode until the hydraulic pressure corresponding to the stroke range during vehicle braking is not zero.

[0123] In one embodiment of the present application, when there is brake noise in the vehicle, the stroke parameter of the brake device and the hydraulic pressure of the hydraulic brake are calibrated to obtain a stroke-pressure relationship. The steps of calibrating the stroke-pressure relationship in the embodiment of the present application include:

[0124] 1. When there is braking noise in the vehicle, obtain the travel range of the braking device and the hydraulic pressure corresponding to the travel range;

[0125] 2. Adjust the hydraulic pressure until the braking noise of the vehicle disappears, thereby obtaining a hydraulic pressure range;

[0126] 3. Associating the stroke interval with the hydraulic interval to obtain the stroke pressure relationship.

[0127] That is, in the embodiment of the present application, when there is braking noise in the vehicle, the travel range of the braking device and the hydraulic pressure corresponding to the travel range are obtained, wherein the travel range in the embodiment of the present application may be one or more, and when there are multiple travel ranges, the travel range may be continuous or discontinuous, which is not limited in the embodiment of the present application. In the embodiment of the present application, when there is braking noise, the travel range is recorded, and the hydraulic pressure corresponding to the travel range is obtained, and then the hydraulic pressure is adjusted, wherein the method of adjusting the hydraulic pressure is not limited, for example, adjusting the hydraulic pressure may be increasing the hydraulic pressure, or reducing the hydraulic pressure, until the braking noise of the vehicle disappears, and the hydraulic pressure in the process from the existence of the braking noise to the disappearance of the braking noise is obtained as the hydraulic range, and the travel range and the hydraulic range are associated to obtain the travel-pressure relationship.

[0128] In the embodiment of the present application, the stroke interval is used to characterize the user's braking demand. During the stroke-pressure relationship calibration process, the stroke interval is not adjusted, but the braking hydraulic pressure of the hydraulic brake is controlled. In the embodiment of the present application, during the vehicle braking calibration process, the stroke parameter with braking noise is set to the stroke interval, and further, the hydraulic interval corresponding to the stroke interval is set to zero. During the vehicle braking process, the vehicle braking control is performed according to the stroke-pressure relationship to avoid braking noise.

[0129] In the embodiment of the present application, the stroke parameter of the braking device and the stroke interval in the stroke pressure relationship are compared, and the hydraulic pressure of the hydraulic brake and the hydraulic interval in the stroke pressure relationship are compared. When the stroke parameter matches the stroke interval in the stroke pressure relationship, and the hydraulic pressure matches the hydraulic interval in the stroke pressure relationship, feedback braking is started to perform braking control.

[0130] In some embodiments of the present application, the hydraulic interval is determined according to the stroke parameter of the brake device and the stroke-pressure relationship; and the stroke interval is determined according to the hydraulic pressure of the hydraulic brake and the stroke-pressure relationship. Figure 5 , query the stroke-pressure relationship, obtain the hydraulic pressure corresponding to the stroke parameter, and determine whether the hydraulic pressure is zero; and query the stroke-pressure relationship, determine whether the stroke parameter corresponding to the hydraulic pressure of the hydraulic brake is the stroke interval corresponding to the braking noise, and when the stroke interval in the stroke parameter and the stroke pressure relationship match, and the hydraulic pressure matches the hydraulic interval in the stroke pressure relationship, start feedback braking to perform braking control, so as to avoid braking noise caused by hydraulic braking through feedback control.

[0131] In some examples, when the stroke-pressure relationship calibration is performed in the embodiments of the present application, the vehicle brake noise calibration usually occurs before the vehicle is put into use, that is, the vehicle factory test in the embodiments of the present application needs to predetermine the brake noise, according to the inherent relationship between stick-slip vibration and system parameters:

[0132] Through the theoretical analysis and numerical calculation of the above formula, it can be concluded that when the hydraulic pressure is within the interval (b1, b2) (such as Figure 4 As shown), (b1, b2) corresponds to the hydraulic pressure interval with negative damping; in order to ensure data accuracy, the formula calculation is combined with the actual vehicle situation. In the embodiment of the present application, when the vehicle is tested at the factory, the presence of braking noise is recorded, and the stroke parameters of the braking device and the hydraulic pressure of the hydraulic brake are calibrated to obtain the stroke-pressure relationship. The stroke-pressure relationship is calibrated according to the braking noise, so that the vehicle braking control reduces noise.

[0133] In some embodiments, when the vehicle speed is less than a speed threshold, regenerative braking is started to perform braking control based on the stroke parameters of the braking device and the hydraulic pressure of the hydraulic brake, wherein the speed threshold is the maximum speed of the vehicle when there is braking noise, for example, the speed threshold is x1 km / h. In the embodiment of the present application, braking control is performed after the vehicle is at a low speed, which can ensure that the problem of abnormal noise generated when new energy vehicles start is solved. In the embodiment of the present application, an innovative solution for the specific situation of low-speed braking is proposed, which aims to effectively reduce the probability of abnormal noise under low speed and continuous braking, improve the NVH performance of the vehicle, and allow the driver to enjoy a quieter and more comfortable driving experience.

[0134] The main reason for the abnormal noise caused by low-speed braking in the embodiment of the present application is the matching of the disc resonance frequency. The dynamic characteristics of the braking system determine the existence of the resonance frequency. When the frequency of wheel rotation matches a certain natural frequency of the braking system, resonance may be induced, resulting in noise amplification. In the current braking control strategy, when the vehicle speed is below a certain threshold, the system will switch to relying entirely on hydraulic braking to provide the required braking force, and the regenerative braking function will be disabled.

[0135] In one embodiment, when the vehicle speed is less than a speed threshold, and the stroke parameter of the braking device and the hydraulic pressure of the hydraulic brake meet a second condition, braking control is performed through feedback braking; wherein the speed threshold is the maximum speed of the vehicle when braking noise occurs; in this embodiment, low-speed braking control is performed according to the vehicle speed to reduce low-speed braking noise.

[0136] In one embodiment, when the braking duration of the vehicle is greater than a duration threshold, and the stroke parameters of the braking device and the hydraulic pressure of the hydraulic brake meet the second condition, braking control is performed through feedback braking; wherein the duration threshold is the minimum duration for the vehicle to generate braking noise; in this embodiment, low-speed braking control is performed according to the braking duration to shorten the noise time.

[0137] In one embodiment, the second condition is determined according to a calibrated second stroke pressure relationship; wherein the second stroke pressure relationship is a pre-calibrated association relationship between the second stroke interval and the second hydraulic interval.

[0138] Reference Fig. 9 In the implementation of this application, when the abnormal sound frequency is identified to be less than the frequency threshold and greater than the noise threshold during vehicle calibration, the vehicle speed, push rod stroke and hydraulic pressure are recorded, wherein the frequency threshold is the vehicle noise frequency, for example, the frequency threshold is xxxHz, and the noise threshold is xxx decibels. It should be supplemented that the specific frequency threshold and noise threshold are set according to the specific scenario. For example, the description in the embodiment of this application that the noise threshold does not exceed xx decibels does not constitute a limitation on the technical solution of this application. xx decibels can be 60 decibels, 70 decibels, or others.

[0139] When an abnormal noise is detected, the vehicle speed, push rod stroke and hydraulic pressure are recorded; the vehicle operating condition is obtained to determine whether the vehicle speed is less than the set threshold x1 km / h, and whether the hydraulic pressure is in the set hydraulic pressure range of b8 to b9, and when the push rod stroke is between a8 and a9, it is recognized that the vehicle is in the operating condition of low-speed continuous braking. At this time, the integrated intelligent brake control unit sends a signal to the electronic control unit (ECU) to request the start of the regenerative braking mode to replace hydraulic braking.

[0140] The embodiment of the present application is an optimized control strategy for the brake system at low vehicle speeds. By intelligently adjusting the integrated pressure brake module, the performance under this specific condition is effectively managed, the brake disc resonance and brake noise problems are solved, and the stable contact between the brake disc and the friction material is ensured. This strategy is only for the above-mentioned specific working conditions and may have an impact on other vehicle operating scenarios.

[0141] Based on the above problems, our company has proposed an innovative technical solution to reduce the risk of resonance under low-speed driving and continuous braking, thereby improving the stability and noise control of the braking system. This solution is not to develop a new braking system, but to achieve precise regulation of brake pressure through software optimization of the existing braking system. This strategy will consider maintaining continuous participation of regenerative braking under low braking pressure, and dynamically adjust the participation mode and timing of hydraulic braking to avoid unnecessary resonance effects while ensuring the reliability of braking performance. Figure 6As shown in the figure, when the vehicle speed, master cylinder pressure and push rod stroke are in abnormal noise conditions, that is, when the push rod stroke is in the range of a8-a9 mm and the hydraulic pressure is in the range of b8-b9 bar, the hydraulic brake is switched to regenerative braking (the hydraulic pressure is 0 bar at this time) to avoid the abnormal noise brake pressure range. Through this innovation, the braking system can maintain better acoustic performance and higher operating comfort under different working conditions.

[0142] In one embodiment, when the travel parameter of the brake device satisfies the second travel range and the hydraulic pressure of the hydraulic brake satisfies the second hydraulic pressure range, braking control is performed by feedback braking. The second travel range includes a8-a9 mm, and the second hydraulic pressure range includes b8-b9 bar.

[0143] like Figure 6 As shown in the figure, when the vehicle speed is less than the speed threshold, when the brake pedal travel is less than threshold A and the hydraulic pressure is lower than threshold B, the natural frequency of the braking system tends to overlap with the braking frequency under the working conditions of low speed and continuous braking. This frequency overlap will cause resonance between the friction disc and the friction plate, which will in turn cause the generation of braking noise. In this case, using feedback braking instead of hydraulic braking can reduce the braking noise.

[0144] It is understandable that in order to reduce the risk of resonance under low-speed driving and continuous braking, thereby improving the stability and noise control of the braking system, the technical solution of this application realizes a precise adjustment function by optimizing the existing braking system. This strategy will consider maintaining the continuous participation of regenerative braking at low vehicle speeds, and dynamically adjust the application method and timing of hydraulic braking to avoid unnecessary resonance effects while ensuring the reliability of braking performance. Through the technical solution of this application, the braking system can maintain better acoustic performance and higher operating comfort under different working conditions.

[0145] In some embodiments of the present application, when the braking duration of the vehicle is greater than a duration threshold, regenerative braking is initiated to perform braking control based on the stroke parameters of the braking device and the hydraulic pressure of the hydraulic brake; wherein the duration threshold is the minimum duration for which the vehicle generates braking noise.

[0146] In the embodiment of the present application, in the case where continuous braking generates brake noise, by monitoring the braking duration, when the braking duration of the vehicle is greater than a duration threshold, feedback braking is started to perform brake control based on the stroke parameters of the braking device and the hydraulic pressure of the hydraulic brake; brake noise caused by inaccurate hydraulic pressure due to long-term hydraulic braking can be avoided.

[0147] In the embodiment of the present application, when performing braking control, the braking time and vehicle speed can be combined for control to effectively reduce braking noise.

[0148] In one embodiment of the present application, when the stroke parameter of the brake device does not match the stroke interval, or the hydraulic pressure does not match the hydraulic interval, the brake control is performed by the intelligent brake integrated control system. That is, in the embodiment of the present application, when the stroke parameter of the brake device does not match the stroke interval, or the hydraulic pressure does not match the hydraulic interval, the brake control is continued to be performed by the intelligent brake integrated control system (IPB, the full name is Integrated Power Brake, the Chinese full name is "integrated power brake system"), effectively ensuring the braking accuracy.

[0149] For ease of understanding, the entire process from stroke pressure relationship calibration to brake control in the embodiment of the present application is described, with reference to Figure 7 and Figure 8 , Figure 7 In the embodiment of the present application, when abnormal braking noise of the vehicle is identified, the vehicle speed, push rod stroke, and hydraulic pressure of the hydraulic master cylinder are recorded, the stroke-pressure relationship is calibrated, and the calibrated stroke-pressure relationship is saved. During real-time braking of the vehicle, the working condition of the vehicle is identified to determine whether the push rod stroke of the real-time brake push rod of the vehicle is within the calibrated stroke range, and whether the brake hydraulic pressure of the vehicle's hydraulic brake is within the calibrated hydraulic range. When it is determined that the push rod stroke of the vehicle is within the calibrated stroke range, and the brake hydraulic pressure of the vehicle's hydraulic brake is within the calibrated hydraulic range, motor feedback braking is used to replace hydraulic braking; when it is determined that the push rod stroke of the vehicle is not within the calibrated stroke range, or the brake hydraulic pressure of the vehicle's hydraulic brake is not within the calibrated hydraulic range, the original braking strategy is maintained.

[0150] That is, reference Figure 8 , Figure 8 In the embodiment of the present application, the pedal travel and hydraulic pressure information under the abnormal noise working condition are obtained; the working condition of the vehicle is obtained, and it is determined whether the vehicle speed is less than the set threshold, and whether the pedal travel is in the set travel range, so as to identify that the vehicle belongs to the working condition of low-speed continuous braking. At this time, the integrated intelligent brake control unit sends a signal to the electronic control unit (ECU) to request to start the regenerative braking mode to replace hydraulic braking. This strategy ensures that the contact relationship between the brake disc and the friction material is more uniform and stable by switching to regenerative braking, thereby significantly reducing the noise caused by resonance. In the embodiment of the present application, the system can intelligently adjust the braking response to avoid resonance caused by hydraulic instability during low-speed braking.

[0151] In one embodiment, Fig. 9An example is used to illustrate a specific scenario. When the time is t1 seconds, due to the pressure range reached by the hydraulic brake pressure, the hydraulic brake pressure drops rapidly from b1Bar to 0Bar, while the regenerative braking torque rises to c1Nm. This strategy switches to regenerative braking, cutting off the contact between the brake disc and the friction material in the abnormal brake pressure range, thereby significantly reducing the noise caused by resonance. In this way, the system can intelligently adjust the braking response to avoid resonance caused by hydraulic instability during low-speed braking.

[0152] During the braking process of the vehicle, the vehicle speed gradually decreases at a first change rate, and the stroke parameter of the braking device in the vehicle gradually increases at a second change rate. The first change rate is related to the second change rate. According to the specific scenario setting, the vehicle speed gradually decreases along with the stroke parameter during braking.

[0153] Specifically, during the braking process of the vehicle, a travel parameter of a braking device in braking the vehicle gradually increases.

[0154] In one embodiment of the present application, the braking process of the vehicle includes at least two time intervals, wherein the rate of change of the hydraulic pressure in each time interval is different; and the rate of change of the feedback torque corresponding to the feedback braking in each time interval is different. In the first braking time interval of the vehicle, the hydraulic pressure gradually increases from 0 to the hydraulic interval, and the hydraulic interval includes the first hydraulic interval or the second hydraulic interval; in the second braking time interval of the vehicle, the hydraulic pressure is first adjusted from the pressure interval to 0 or greater than the hydraulic interval.

[0155] For example, refer to Fig. 9 , the first braking time interval is the first time interval T1, and the second braking time interval includes at least one of the second time interval T2-the fifth time interval T5, wherein in the first time interval T1, the hydraulic pressure gradually increases from 0 to the first pressure value at a third change rate; the vehicle starts hydraulic braking normally, and the third change rate is set according to the specific scenario; in the second time interval T2, the hydraulic pressure gradually decreases from the first pressure value to 0 at a fourth change rate; feedback braking gradually replaces hydraulic braking; in the third time interval T3, the hydraulic pressure is maintained at 0; feedback braking avoids braking noise caused by inaccurate hydraulic braking; in the fourth time interval T4, the hydraulic pressure gradually increases to the second pressure value at a fifth change rate; the feedback braking power is insufficient, and hydraulic braking is increased to avoid the noise generated by hydraulic braking while ensuring the braking effect; in the fifth time interval T5, the hydraulic pressure gradually increases to the third pressure value at a sixth change rate; the vehicle is braked significantly to reduce the vehicle speed.

[0156] In the embodiment of the present application, the vehicle hydraulic pressure is adjusted according to the above-mentioned different change rates, so that the vehicle speed can be controlled according to the user's braking control requirements, and the braking noise during the vehicle braking process is ensured not to exceed the noise threshold of 60 decibels.

[0157] Among them, the first time interval T1, the second time interval T2, the third time interval T3, the fourth time interval T4 and the fifth time interval T5 are consecutive intervals in sequence, the first pressure value is less than the second pressure value and less than the third pressure value, and in the embodiment of the present application, the second pressure value and the third pressure value are determined according to the control conditions of the hydraulic braking and feedback braking in the vehicle.

[0158] Reference Fig. 9 , the first time interval T1 is 10s-15s, the second time interval T2 is 15s-17s, the third time interval T3 is 17s-20s, the fourth time interval T4 is 20s-21s, and the fifth time interval T5 is 21 to 25s.

[0159] In one embodiment, the absolute value of the fourth rate of change is greater than the absolute value of the third rate of change, and the fifth rate of change is greater than the sixth rate of change. The first rate of change, the second rate of change, the third rate of change, the fourth rate of change, the fifth rate of change and the sixth rate of change in the embodiment of the present application are determined according to the braking condition of the vehicle, and the specific values ​​of the first rate of change, the second rate of change, the third rate of change, the fourth rate of change, the fifth rate of change and the sixth rate of change do not constitute a limitation to this solution.

[0160] In one embodiment of the present application, in a first braking time interval of the vehicle, the feedback torque is 0; in a second braking time interval of the vehicle, the feedback torque gradually increases from 0 to a first torque value.

[0161] Reference Fig. 9 , the first braking time interval is the first time interval T1, and the second braking time interval includes at least one of the second time interval T2-fifth time interval T5, wherein in the first time interval T1, the feedback torque is 0; in the second time interval T2, the feedback torque gradually increases from 0 to the first torque value at the seventh change rate; in the third time interval T3, the feedback torque gradually increases from the first torque value to the second torque value at the eighth change rate; in the fourth time interval T4, the feedback torque gradually decreases from the second torque value to 0 at the ninth change rate;

[0162] Wherein, the first torque value is smaller than the second torque value.

[0163] In one embodiment, the seventh change rate is greater than the eighth change rate, and the absolute value of the ninth change rate is greater than the absolute value of the eighth change rate. In the embodiment of the present application, the change rate is limited, which can not only ensure the vehicle system effect, but also reduce the vehicle braking noise.

[0164] The seventh change rate, the eighth change rate and the ninth change rate in the embodiment of the present application are determined according to the braking condition of the vehicle, and the specific values ​​of the seventh change rate, the eighth change rate and the ninth change rate do not constitute a limitation to this scheme.

[0165] In this embodiment, the regenerative braking is not started at the beginning, but is gradually increased and controlled, and then exits and is controlled by the hydraulic brake, thereby achieving effective braking of the vehicle while reducing braking noise.

[0166] parameter Fig. 9 According to the changing trend of relevant parameters for braking control in the embodiment of the present application, the embodiment of the present application includes vehicle speed (km / h), push rod stroke (mm), hydraulic pressure (bar) and feedback torque (N*m) corresponding to feedback braking. In the embodiment of the present application, during the braking process of the vehicle at a speed of x1 km / h-x2 km / h, it is detected that the push rod stroke of the vehicle increases from a0 mm to a1 mm, and the hydraulic pressure increases from b0 bar to b1 bar. Then, feedback braking is started, and the hydraulic pressure is reduced to 0 bar. During this process, the feedback torque generated by the feedback braking increases from 0 to the set feedback torque, indicating that the feedback braking is started during the braking process of the vehicle. When the detected stroke parameter exceeds the calibrated stroke range, the feedback braking is controlled to be turned off and normal braking control is started.

[0167] According to a first aspect of the present application, the present application provides a braking control device, comprising: an adjustment module, configured to perform braking control through feedback braking when a braking parameter satisfies a first condition.

[0168] In the embodiment of the present application, the braking control device performs braking control through feedback braking when the braking parameters meet the first condition. Through the above technical solution, the software of the braking system is optimized, and precise adjustment of the braking is achieved through the feedback braking solution according to the stroke parameters and hydraulic pressure, so as to avoid unnecessary resonance effects and reduce braking noise.

[0169] In some embodiments, the braking parameters include: travel parameters of the braking device and hydraulic pressure of the hydraulic brake;

[0170] During the regenerative braking, the hydraulic pressure is 0.

[0171] Optionally, the device further comprises:

[0172] The first condition is determined according to a calibrated first stroke pressure relationship; wherein the first stroke pressure relationship is a pre-calibrated association relationship between a first stroke interval and a first hydraulic interval.

[0173] Optionally, the device further comprises:

[0174] When the stroke parameter of the brake device satisfies the first stroke range, and the hydraulic pressure of the hydraulic brake satisfies the first hydraulic range, performing braking control through feedback braking;

[0175] The first stroke interval and the first hydraulic interval are when the braking noise exceeds a noise threshold during vehicle braking.

[0176] Optionally, the device further comprises:

[0177] When the vehicle speed is less than the vehicle speed threshold, and the travel parameter of the brake device and the hydraulic pressure of the hydraulic brake meet the second condition, performing braking control through feedback braking;

[0178] The vehicle speed threshold is the maximum vehicle speed when the vehicle has braking noise.

[0179] Optionally, the device further comprises:

[0180] When the braking time of the vehicle is greater than the time threshold, and the stroke parameter of the braking device and the hydraulic pressure of the hydraulic brake meet the second condition, performing braking control through feedback braking;

[0181] The duration threshold is the minimum duration for the vehicle to generate braking noise.

[0182] Optionally, the device further comprises:

[0183] The second condition is determined according to a calibrated second stroke pressure relationship; wherein the second stroke pressure relationship is a pre-calibrated association relationship between a second stroke interval and a second hydraulic interval.

[0184] Optionally, the device further comprises:

[0185] When the stroke parameter of the brake device satisfies the second stroke range, and the hydraulic pressure of the hydraulic brake satisfies the second hydraulic range, braking control is performed through feedback braking.

[0186] The first stroke interval and the first hydraulic interval are when the braking noise exceeds a noise threshold during vehicle braking.

[0187] Optionally, the device is also used for:

[0188] When the vehicle speed is less than the vehicle speed threshold, and the travel parameter of the brake device and the hydraulic pressure of the hydraulic brake meet the second condition, performing braking control through feedback braking;

[0189] The vehicle speed threshold is the maximum vehicle speed when the vehicle has braking noise.

[0190] Optionally, the device is also used for:

[0191] When the braking time of the vehicle is greater than the time threshold, and the stroke parameter of the braking device and the hydraulic pressure of the hydraulic brake meet the second condition, performing braking control through feedback braking;

[0192] The duration threshold is the minimum duration for the vehicle to generate braking noise.

[0193] Optionally, the device is also used for:

[0194] The second condition is determined according to a calibrated second stroke pressure relationship; wherein the second stroke pressure relationship is a pre-calibrated association relationship between a second stroke interval and a second hydraulic interval.

[0195] Optionally, the device is also used for:

[0196] When the stroke parameter of the brake device satisfies the second stroke range, and the hydraulic pressure of the hydraulic brake satisfies the second hydraulic range, performing braking control through feedback braking;

[0197] The second stroke interval and the second hydraulic interval are when the braking noise exceeds a noise threshold during low-speed braking of the vehicle.

[0198] Optionally, the device is also used for:

[0199] When the vehicle has brake noise, the stroke parameter of the brake device and the hydraulic pressure of the hydraulic brake are calibrated to obtain the stroke-pressure relationship.

[0200] Optionally, the device is further used to calibrate the stroke parameter of the brake device and the hydraulic pressure of the hydraulic brake when the vehicle has brake noise, and obtain the stroke-pressure relationship, including:

[0201] In the case where the vehicle has braking noise, obtaining the travel range of the braking device and the hydraulic pressure corresponding to the travel range;

[0202] Adjusting the hydraulic pressure until the braking noise of the vehicle disappears, thereby obtaining a hydraulic pressure range;

[0203] The stroke interval and the hydraulic interval are associated to obtain the stroke pressure relationship.

[0204] Optionally, the device is also used for:

[0205] During the stroke-pressure relationship calibration process, the sound frequency is less than or equal to the noise frequency and greater than or equal to the noise threshold.

[0206] During the braking process of the vehicle, the vehicle speed gradually decreases at a first change rate, and the travel parameter of the braking device in the vehicle gradually increases at a second change rate.

[0207] Optionally, the device is also used for:

[0208] The braking process of the vehicle includes at least two braking time intervals, wherein the change rate of the hydraulic pressure in each time interval is different; and the change rate of the feedback torque corresponding to the feedback braking in each time interval is different.

[0209] Optionally, the device is also used in a vehicle braking process including:

[0210] In the first time interval T1, the hydraulic pressure gradually increases from 0 to the hydraulic interval at a third change rate, and the hydraulic interval includes the first hydraulic interval or the second hydraulic interval;

[0211] In a second time interval T2, the hydraulic pressure gradually decreases from the first pressure value to 0 at a fourth change rate;

[0212] In the third time interval T3, the hydraulic pressure is maintained at 0;

[0213] In a fourth time interval T4, the hydraulic pressure gradually increases to a second pressure value at a fifth change rate;

[0214] In the fifth time interval T5, the hydraulic pressure gradually increases to a third pressure value at a sixth change rate.

[0215] Optionally, the first time interval T1, the second time interval T2, the third time interval T3, the fourth time interval T4 and the fifth time interval T5 are consecutive intervals in sequence, and the first pressure value is smaller than the second pressure value and smaller than the third pressure value.

[0216] Optionally, the device is also used in a braking process of the vehicle, comprising:

[0217] In the first time interval T1, the feedback torque of the vehicle feedback braking is 0;

[0218] In the second time interval T2, the feedback torque gradually increases from 0 to the first torque value according to a seventh change rate;

[0219] In the third time interval T3, the feedback torque gradually increases from the first torque value to the second torque value at an eighth change rate;

[0220] In the fourth time interval T4, the feedback torque gradually decreases from the second torque value to 0 at a ninth change rate;

[0221] Wherein, the first torque value is smaller than the second torque value.

[0222] Optionally, the seventh change rate is greater than the eighth change rate, and an absolute value of the ninth change rate is greater than an absolute value of the eighth change rate.

[0223] Optionally, the braking device comprises a brake pedal of the vehicle and / or a brake push rod in a brake master cylinder in the vehicle;

[0224] The stroke parameters include: pedal stroke and / or push rod stroke.

[0225] Optionally, when the braking parameter does not satisfy the first condition, or the braking parameter does not satisfy the second condition, braking control is performed through an intelligent braking integrated control system.

[0226] Optionally, during the braking control, the braking noise does not exceed a noise threshold.

[0227] Optionally, the noise threshold is 60 decibels.

[0228] A schematic diagram of the structure of a brake control device provided in an embodiment of the present application. The specific implementation of these modules and more details in the embodiment of the present application can be found in the corresponding method part, which will not be repeated here.

[0229] An embodiment of the present application also provides a computer-readable storage medium, on which instructions are stored. When the instructions are executed by a processor, the processor is configured to execute the above-mentioned braking control method.

[0230] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0231] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0232] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0233] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0234] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0235] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0236] Computer readable media include permanent and non-permanent, removable and non-removable media, and can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated communication signals and carrier waves.

[0237] In an embodiment of the present application, a controller is provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are implemented. In an embodiment of the present application, the controller starts the feedback braking to perform braking control according to the stroke parameter of the brake device and the hydraulic pressure of the hydraulic brake. Through the above technical solution, by optimizing the software of the brake system, the feedback braking solution is used to achieve precise adjustment of the brake according to the stroke parameter and the hydraulic pressure, so as to avoid unnecessary resonance effects and reduce braking noise.

[0238] A vehicle is proposed in an embodiment of the present application, comprising a braking control device, a computer-readable storage medium, and at least one of a controller. The vehicle starts regenerative braking to perform braking control according to the stroke parameters of the braking device and the hydraulic pressure of the hydraulic brake. Through the above technical solution, by optimizing the software of the braking system, precise adjustment of the braking is achieved through the regenerative braking solution according to the stroke parameters and the hydraulic pressure, so as to avoid unnecessary resonance effects and reduce braking noise.

[0239] like Fig.10 , which is a schematic diagram of a vehicle architecture provided in an embodiment of the present application. In this embodiment, the vehicle includes a brake device. In this embodiment, the vehicle may be a fuel vehicle, a plug-in hybrid vehicle, or a new energy vehicle, etc., and this application does not specifically limit this.

[0240] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0241] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0242] The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0243] The above are only preferred embodiments of the present application and do not constitute any form of limitation to the present application. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A braking control method, characterized in that: The method is applied to a vehicle, and comprises: When the braking parameter meets the first condition, braking control is performed through feedback braking.

2. The method according to claim 1, characterized in that The braking parameters include: the travel parameters of the braking device and the hydraulic pressure of the hydraulic brake; During the regenerative braking, the hydraulic pressure is 0.

3. The method according to claim 2, characterized in that The method further comprises: The first condition is determined according to a calibrated first stroke pressure relationship; wherein the first stroke pressure relationship is a pre-calibrated association relationship between a first stroke interval and a first hydraulic interval.

4. The method according to claim 3, characterized in that The method further comprises: When the stroke parameter of the brake device satisfies the first stroke range, and the hydraulic pressure of the hydraulic brake satisfies the first hydraulic range, performing braking control through feedback braking; The first stroke interval and the first hydraulic interval are when the braking noise exceeds a noise threshold during vehicle braking.

5. The method according to claim 2, characterized in that: The method further comprises: When the vehicle speed is less than the vehicle speed threshold, and the travel parameter of the brake device and the hydraulic pressure of the hydraulic brake meet the second condition, performing braking control through feedback braking; The vehicle speed threshold is the maximum vehicle speed when the vehicle has braking noise.

6. The method according to claim 2, characterized in that The method further comprises: When the braking time of the vehicle is greater than the time threshold, and the stroke parameter of the braking device and the hydraulic pressure of the hydraulic brake meet the second condition, performing braking control through feedback braking; The duration threshold is the minimum duration for the vehicle to generate braking noise.

7. The method according to claim 5 or 6, characterized in that: The method further comprises: The second condition is determined according to a calibrated second stroke pressure relationship; wherein the second stroke pressure relationship is a pre-calibrated association relationship between a second stroke interval and a second hydraulic interval.

8. The method according to claim 7, characterized in that The method further comprises: When the stroke parameter of the brake device satisfies the second stroke range, and the hydraulic pressure of the hydraulic brake satisfies the second hydraulic range, performing braking control through feedback braking; The second stroke interval and the second hydraulic interval are when the braking noise exceeds a noise threshold during low-speed braking of the vehicle.

9. The method according to claim 3 or 7, characterized in that: The method further comprises: When the vehicle has brake noise, the stroke parameter of the brake device and the hydraulic pressure of the hydraulic brake are calibrated to obtain the stroke-pressure relationship.

10. The method according to claim 9, characterized in that In the case where the vehicle has brake noise, the stroke parameter of the brake device and the hydraulic pressure of the hydraulic brake are calibrated to obtain the stroke-pressure relationship, including: In the case where the vehicle has braking noise, obtaining the travel range of the braking device and the hydraulic pressure corresponding to the travel range; Adjusting the hydraulic pressure until the braking noise of the vehicle disappears, thereby obtaining a hydraulic pressure range; The stroke interval and the hydraulic interval are associated to obtain the stroke pressure relationship.

11. The method according to claim 10, characterized in that The method further comprises: During the stroke-pressure relationship calibration process, the sound frequency is less than or equal to the noise frequency and greater than or equal to the noise threshold.

12. The method according to claim 1, characterized in that The method further comprises: During the braking process of the vehicle, the vehicle speed gradually decreases at a first change rate, and the travel parameter of the braking device in the vehicle gradually increases at a second change rate.

13. The method according to claim 3 or 7, characterized in that: The method further comprises: The braking process of the vehicle includes at least two time intervals, wherein the change rate of the hydraulic pressure in each time interval is different; and the change rate of the feedback torque corresponding to the feedback braking in each time interval is different.

14. The method according to claim 13, characterized in that The braking process of the vehicle includes: In the first time interval T1, the hydraulic pressure gradually increases from 0 to the hydraulic interval at a third change rate, and the hydraulic interval includes the first hydraulic interval or the second hydraulic interval; In the second time interval T2, the hydraulic pressure gradually decreases from the first pressure value to 0 at a fourth change rate; In the third time interval T3, the hydraulic pressure is maintained at 0; In a fourth time interval T4, the hydraulic pressure gradually increases to a second pressure value at a fifth change rate; In the fifth time interval T5, the hydraulic pressure gradually increases to a third pressure value at a sixth change rate.

15. The method according to claim 14, characterized in that The method further comprises: The first time interval T1, the second time interval T2, the third time interval T3, the fourth time interval T4 and the fifth time interval T5 are consecutive intervals, and the first pressure value is smaller than the second pressure value and smaller than the third pressure value.

16. The method according to claim 14, characterized in that The braking process of the vehicle also includes: In the first time interval T1, the feedback torque of the vehicle feedback braking is 0; In the second time interval T2, the feedback torque gradually increases from 0 to the first torque value according to a seventh change rate; In the third time interval T3, the feedback torque gradually increases from the first torque value to the second torque value at an eighth change rate; In the fourth time interval T4, the feedback torque gradually decreases from the second torque value to 0 at a ninth change rate; Wherein, the first torque value is smaller than the second torque value.

17. The method according to claim 16, characterized in that The method further comprises: The seventh change rate is greater than the eighth change rate, and an absolute value of the ninth change rate is greater than an absolute value of the eighth change rate.

18. The method according to claim 2, characterized in that The braking device comprises a brake pedal of the vehicle and / or a brake push rod in a brake master cylinder in the vehicle; The stroke parameters include: pedal stroke and / or push rod stroke.

19. The method according to any one of claims 1 to 18, characterized in that: The method further comprises: When the braking parameter does not satisfy the first condition, or the braking parameter does not satisfy the second condition, braking control is performed through an intelligent braking integrated control system.

20. The method according to any one of claims 1 to 18, characterized in that: The method further comprises: During the braking control, the braking noise does not exceed a noise threshold.

21. The method according to claim 20, characterized in that The noise threshold is 60 decibels.

22. A brake control device, characterized in that: include: The adjustment module is used to perform braking control through feedback braking when the braking parameter meets the first condition.

23. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 21 are implemented.

24. A controller having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 21 are implemented.

25. A vehicle, characterized in that: Includes a braking device, and at least one of the braking control apparatus of claim 22, the computer-readable storage medium of claim 23, and the controller of claim 24.

26. A computer program product, characterized in that The method comprises a computer program or instructions, which implement the steps of the method according to any one of claims 1 to 21 when executed by a processor.

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