Method and device for optimizing starting brake peristaltic noise, vehicle and storage medium

Abstract

The application discloses a starting brake peristalsis noise optimization method and device, vehicle and storage medium, relates to the technical field of vehicle noise optimization, and aims to reduce peristalsis noise generated in the starting brake process of the vehicle. The method comprises the following steps: determining the brake pressure of the longitudinal force balance point of the vehicle; determining the to-be-corrected brake pressure corresponding to the preset brake push rod stroke range; determining the target brake pressure corresponding to the preset brake push rod stroke range based on a noise reduction pressure gradient model and the to-be-corrected brake pressure corresponding to the preset brake push rod stroke range; the noise reduction pressure gradient model is configured to adjust the gradient relationship between the to-be-corrected brake pressure of the preset brake push rod stroke range and the brake push rod stroke, so that at the longitudinal force balance point, the change rate of the target brake pressure relative to the brake push rod stroke is greater than the change rate of the to-be-corrected brake pressure relative to the brake push rod stroke; and driving the vehicle brake based on the target brake pressure to reduce the peristalsis noise of the vehicle when the brake push rod stroke is in action.

Description

Technical Field

[0001] This invention relates to the field of vehicle noise optimization technology, specifically to a method, device, vehicle, and storage medium for optimizing starting, braking, and creeping noise. Background Technology

[0002] During the vehicle's initial acceleration phase, as the driver engages drive and slowly releases the brake pedal, the vehicle gradually begins to creep from a standstill. During this process, the brake disc and friction pads are in a stick-slip state at extremely low relative speeds, which can easily generate creeping noise, manifesting as a perceptible "clunking" sound inside the vehicle, affecting driving comfort.

[0003] In related technologies, methods to suppress creep noise mainly include hardware solutions such as improving friction pad materials, optimizing brake disc structure, or adjusting suspension bushings. However, these solutions have drawbacks such as long development cycles, high costs, and potential sacrifice of other braking performance.

[0004] Therefore, there is an urgent need for a technical solution that can accurately and cost-effectively suppress starting and braking creep noise. Summary of the Invention

[0005] One of the objectives of this invention is to provide a method, apparatus, vehicle, and storage medium for optimizing creep noise during vehicle start-up braking. This is achieved by optimizing and adjusting the braking pressure gradient near the longitudinal force balance point of the vehicle to reduce creep noise generated during vehicle start-up braking.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a method for optimizing creep noise during starting braking, applied to a vehicle. The method includes: determining the braking pressure at the vehicle's longitudinal force balance point; the vehicle's longitudinal force balance point indicates the critical point state of the vehicle transitioning from a stationary to a moving state as the vehicle's brake lever travel changes; determining the braking pressure to be corrected corresponding to a preset brake lever travel range based on the braking pressure at the vehicle's longitudinal force balance point; wherein the preset brake lever travel range is determined based on the brake lever travel corresponding to the longitudinal force balance point; determining the target braking pressure corresponding to the preset brake lever travel range based on a noise reduction pressure gradient model and the brake pressure to be corrected corresponding to the preset brake lever travel range; the noise reduction pressure gradient model is configured to adjust the gradient relationship between the brake pressure to be corrected and the brake lever travel within the preset brake lever travel range, such that at the longitudinal force balance point, the rate of change of the target braking pressure relative to the brake lever travel is greater than the rate of change of the brake pressure to be corrected relative to the brake lever travel; and driving the vehicle to brake based on the target braking pressure to reduce creep noise during brake lever travel.

[0007] Based on the aforementioned technical means, this invention first determines the braking pressure corresponding to the longitudinal force balance point from static to dynamic during the change of the brake push rod stroke. Using this as a benchmark, it determines the braking pressure to be corrected within a corresponding preset brake push rod stroke range. Subsequently, a noise-reducing pressure gradient model is used to increase the rate of change of braking pressure at this balance point with the brake push rod stroke, optimizing the gradient relationship between braking pressure and brake push rod stroke. This allows the braking pressure to quickly cross the vehicle's static-to-dynamic switching critical point, reducing fluctuations and stagnation of braking pressure near the balance point. Furthermore, braking control is achieved based on the optimized target braking pressure, effectively mitigating the impact, vibration, and friction noise of the braking mechanism during the start-up creep phase. From a control logic perspective, creep noise is suppressed, improving vehicle braking smoothness and driving quietness.

[0008] Furthermore, based on the noise reduction pressure gradient model and the braking pressure to be corrected corresponding to the preset brake push rod travel range, the target braking pressure corresponding to the preset brake push rod travel range is determined, including: determining the target pressure correction parameter; the target pressure correction parameter is the correction parameter corresponding to the longitudinal force balance point of the vehicle within the preset brake push rod travel range; based on the target pressure correction parameter, a pressure correction parameter curve is constructed, which is used to indicate the mapping relationship between the preset brake push rod travel range and the pressure correction parameter; based on the braking pressure to be corrected corresponding to the preset brake push rod travel range and the pressure correction parameter curve, the target braking pressure corresponding to the preset brake push rod travel range is determined.

[0009] Based on the aforementioned technical means, by determining the target pressure correction parameter and constructing a pressure correction parameter curve based on this parameter, this invention achieves flexible and configurable correction of the braking pressure within a preset brake pushrod stroke range. The target pressure correction parameter can be independently set for different vehicle models or calibration requirements, while the pressure correction parameter curve establishes a continuous mapping relationship between the pushrod stroke and the correction coefficient, making the correction process smooth and predictable. The advantages of this design are twofold: firstly, it only corrects the stroke range near the longitudinal force balance point, without affecting the original braking pressure requirements in other stroke ranges, thus avoiding interference with the vehicle's conventional braking performance and safety; secondly, engineers can intuitively control the degree of pressure gradient enhancement by adjusting the target pressure correction parameter, facilitating rapid adaptation between different vehicle platforms and significantly reducing software calibration difficulty and development costs.

[0010] Furthermore, based on the brake pressure to be corrected and the pressure correction parameter curve corresponding to the preset brake push rod stroke range, the target brake pressure corresponding to the preset brake push rod stroke range is determined, including: obtaining the brake pressure to be corrected corresponding to the lower limit endpoint of the preset brake push rod stroke range as the lower limit pressure, and the brake pressure to be corrected corresponding to the upper limit endpoint of the preset brake push rod stroke range as the upper limit pressure; for any brake push rod stroke within the preset brake push rod stroke range, the corresponding correction coefficient is obtained from the pressure correction parameter curve according to the normalized position of any brake push rod stroke within the preset brake push rod stroke range; based on the lower limit pressure, the upper limit pressure, and the corresponding correction coefficient, the target brake pressure within the preset brake push rod stroke range is determined.

[0011] Based on the aforementioned technical means, when determining the target braking pressure within the preset brake push lever stroke range, this invention employs a method of using lower limit pressure, upper limit pressure, and a normalized position lookup table to obtain the correction coefficient. Specifically, the original braking pressure to be corrected corresponding to the lower and upper limit endpoints of the stroke range is first obtained. Then, for any push lever stroke within the range, its normalized position within the range is calculated. Based on this position, the corresponding correction coefficient is looked up from the pressure correction parameter curve. Finally, the target braking pressure is calculated by combining the lower and upper limit pressures. The beneficial effects of this technical means are: First, since the correction coefficient curve can be designed to make the target pressure equal to the original pressure at the endpoints of the stroke range, a smooth transition without jumps can be achieved between the corrected and uncorrected intervals. The driver cannot feel the switching point of the control logic, ensuring the continuity of the brake pedal feel. Second, the normalized lookup table calculation method is simple and efficient, very suitable for real-time operation in embedded controllers, without adding extra computational burden. Finally, this structure naturally ensures that the target braking pressure changes monotonically and continuously with the push lever stroke within the stroke range, avoiding secondary noise or impact that may be caused by sudden pressure changes.

[0012] Furthermore, the target pressure correction parameters are determined, including: obtaining the slope information of the road surface where the vehicle is currently driving; and selecting the target pressure correction parameters from a preset relationship table based on the slope information. The preset relationship table is used to characterize the correspondence between slope information and pressure correction parameters.

[0013] Based on the aforementioned technical means, this invention, when determining the target pressure correction parameter, acquires the slope information of the current road surface on which the vehicle is currently driving, and selects the corresponding target pressure correction parameter from a preset relationship table according to the slope information. The beneficial effects of this technical means are as follows: Because the position of the vehicle's longitudinal force balance point and creeping stationary characteristics differ under different slopes (for example, greater braking pressure is needed to balance the driving force when starting uphill, and vice versa when going downhill), using a uniform pressure correction parameter may lead to insufficient or excessive correction under non-flat road conditions. By introducing a slope adaptive mechanism, the system can automatically identify different scenarios such as flat roads, uphill, and downhill, and retrieve targeted correction parameters, thereby ensuring effective suppression of creep noise under various actual driving conditions, while avoiding starting shock or braking lag due to over-correction, significantly improving the robustness and scenario coverage of the optimization method.

[0014] Furthermore, based on the target pressure correction parameters, a pressure correction parameter curve is constructed, including: normalizing the brake push rod stroke corresponding to the preset brake push rod stroke range to determine the normalized stroke parameters; determining the segmentation coefficients of the pressure correction parameter curve according to the target pressure correction parameters, the segmentation coefficients including position coefficients and slope adjustment coefficients; constructing the pressure correction parameter curve based on the normalized stroke parameters and segmentation coefficients; the pressure correction parameter curve is used to characterize the mapping relationship between the normalized stroke parameters and the correction coefficients within the preset brake push rod stroke range, and the pressure correction parameter curve is configured such that at the normalized stroke parameter position corresponding to the longitudinal force balance point, the value of the correction coefficient makes the rate of change of the target braking pressure with the brake push rod stroke greater than the rate of change of the braking pressure to be corrected with the brake push rod stroke.

[0015] Based on the aforementioned technical means, this invention, when constructing the pressure correction parameter curve, first normalizes the stroke values ​​within a preset brake push rod stroke range to obtain normalized stroke parameters. Then, it determines the segmentation coefficients based on the target pressure correction parameters, ultimately constructing a mapping curve between the normalized stroke parameters and the correction coefficients. This pressure correction parameter curve is designed such that, at the normalized stroke parameter position corresponding to the longitudinal force balance point, the correction coefficient value ensures that the rate of change of the target braking pressure with the push rod stroke is greater than the rate of change of the original braking pressure to be corrected with the stroke. The beneficial effect of this technical means is that, through the segmentation coefficients, the local shape of the pressure correction curve near the balance point can be controlled very precisely, thereby achieving the effect of "pressure quickly crossing the balance point when the pedal is slowly released," minimizing the vehicle's dwell time in a stick-slip state and suppressing creep noise at its source. Simultaneously, because the curve is segmented and continuous, it does not introduce nonlinear abrupt changes, ensuring the smoothness of the braking pressure.

[0016] Furthermore, determining the braking pressure at the vehicle's longitudinal force balance point includes: determining the braking force at the vehicle's longitudinal force balance point based on the driving force at the vehicle's longitudinal force balance point, the vehicle's weight, and the current slope information of the vehicle; and determining the braking pressure at the vehicle's longitudinal force balance point based on the braking force at the vehicle's longitudinal force balance point through a braking function relationship, wherein the braking function relationship is used to indicate the correspondence between the braking force at the vehicle's longitudinal force balance point and the braking pressure at the vehicle's longitudinal force balance point.

[0017] Based on the aforementioned technical methods, by comprehensively considering three key factors—driving force, weight, and gradient—the braking pressure required for a vehicle to transition precisely from a standstill to motion under current operating conditions can be accurately calculated. This provides a high-precision benchmark for subsequent travel range determination and pressure correction. In particular, the introduction of gradient information allows the equilibrium point pressure to be dynamically adjusted according to road conditions, avoiding the problem of parameters calibrated on flat roads becoming ineffective on slopes. The braking function relationship utilizes the vehicle's existing braking system characteristic parameters, ensuring that the calculated pressure matches the actual hydraulic actuation capability, thus improving engineering feasibility.

[0018] Furthermore, based on the braking pressure at the vehicle's longitudinal force balance point, the braking pressure to be corrected corresponding to the preset brake push rod travel range is determined, including: taking the braking pressure at the longitudinal force balance point as the center, increasing the first calibrated pressure value upwards as the upper limit pressure, and decreasing the second calibrated pressure value downwards as the lower limit pressure, thus forming the braking pressure range to be corrected; using the original vehicle braking demand parameter table, the upper limit pressure and lower limit pressure are interpolated to obtain the corresponding upper limit and lower limit of the brake push rod travel, thus determining the preset brake push rod travel range; wherein, the original vehicle braking demand parameter table is used to indicate the mapping relationship between the brake push rod travel and the braking pressure; within the preset brake push rod travel range, the braking pressure corresponding to each brake push rod travel is obtained according to the original vehicle braking demand parameter table, and determined as the braking pressure to be corrected.

[0019] Based on the aforementioned technical methods, a pressure range is symmetrically or asymmetrically extended around the equilibrium point pressure, ensuring that the correction range completely covers all areas near the equilibrium point where stick-slip may occur, avoiding any omissions in the correction. Secondly, the pressure boundary is converted into the travel boundary using the original vehicle braking requirement parameter table, making the correction range naturally compatible with the characteristics of the original vehicle braking system, eliminating the need to recalibrate the zero point or range of the travel sensor. Thirdly, the braking pressure to be corrected is directly taken from the original vehicle parameter table, ensuring that the system still operates according to the original design when noise reduction correction is not enabled, guaranteeing safety redundancy. Finally, this method clearly defines the correction range as limited to a local area near the equilibrium point, while other travel ranges are completely unaffected, thereby minimizing interference with the overall vehicle braking performance.

[0020] Furthermore, the method also includes: when the vehicle does not meet the first preset condition and / or the vehicle does not meet the second preset condition, controlling the vehicle to brake with a braking pressure to be corrected corresponding to a preset brake lever travel range. The first preset condition includes: the brake pedal switch is open, the vehicle is stationary, the gear is in forward gear, and the slope information is within a set range; the second preset condition includes: the brake lever travel direction is retracting, the brake lever travel retraction speed is greater than or equal to a set threshold, and the brake master cylinder pressure is less than or equal to a first pressure threshold.

[0021] Based on the aforementioned technical means, the first preset condition ensures that the optimization is activated only in typical scenarios where the driver intends to start (pedal switch on, stationary, in drive, moderate slope), avoiding erroneous intervention under abnormal conditions such as reversing, parking, or excessive slope. The second preset condition further restricts the optimization to delicate operational scenarios where the driver slowly releases the pedal (reversing, sufficiently fast speed indicates active pedal release, low master cylinder pressure indicates no emergency braking), preventing changes in pressure characteristics under sudden pedal release or high braking system load, which could affect the emergency braking response speed. Through these condition judgments, the system prioritizes braking safety while improving driving comfort, achieving a perfect balance between noise optimization and safety.

[0022] Furthermore, the method also includes: redetermining the target pressure correction parameter when the rate of change of the target braking pressure relative to the brake push rod stroke is less than or equal to the rate of change of the braking pressure to be corrected relative to the brake push rod stroke.

[0023] Based on the aforementioned technical methods, due to individual differences in vehicle braking systems, aging and wear, or environmental changes (such as brake fluid temperature, friction pad condition, etc.), the preset pressure correction parameters may fail to achieve the expected gradient enhancement effect in actual operation. By comparing the corrected pressure change rate with the original change rate in real time, the system can identify insufficient correction and trigger a process to redetermine the target pressure correction parameters, such as increasing the correction coefficient or adjusting the segmentation coefficient, until the requirement of "change rate greater than" is met. This closed-loop adaptive mechanism ensures the reliability and long-term stability of the optimization effect, avoids the recurrence of start-up creep noise due to parameter failure, and also provides a technical foundation for subsequent intelligent self-learning and online calibration.

[0024] Secondly, this application provides a starting braking creep noise optimization device according to the embodiments of this application, including: a critical point determination module, a determination module, a correction module, and a braking module.

[0025] The critical point determination module is used to: determine the braking pressure at the longitudinal force balance point of the vehicle; the longitudinal force balance point of the vehicle is used to indicate the critical point state of the vehicle from static to dynamic as the travel of the vehicle's brake push rod changes; the determination module is used to: determine the braking pressure to be corrected corresponding to a preset brake push rod travel range based on the braking pressure at the longitudinal force balance point of the vehicle; wherein, the preset brake push rod travel range is determined based on the brake push rod travel corresponding to the longitudinal force balance point; the correction module is used to: determine the target braking pressure corresponding to the preset brake push rod travel range based on a noise reduction pressure gradient model and the braking pressure to be corrected corresponding to the preset brake push rod travel range; the noise reduction pressure gradient model is configured to adjust the gradient relationship between the braking pressure to be corrected and the brake push rod travel in the preset brake push rod travel range, such that at the longitudinal force balance point, the rate of change of the target braking pressure relative to the brake push rod travel is greater than the rate of change of the braking pressure to be corrected relative to the brake push rod travel; the braking module is used to: drive the vehicle to brake based on the target braking pressure to reduce the creep noise of the vehicle during the brake push rod travel.

[0026] Thirdly, this application provides an electronic device comprising: a processor and a memory; the memory storing processor-executable instructions. When the processor is configured to execute the instructions, the electronic device implements the method described in the first aspect.

[0027] Fourthly, this application provides a vehicle that includes the electronic equipment described in the third aspect.

[0028] Fifthly, this application provides a computer-readable storage medium that, when the instructions in the computer-readable storage medium are executed by a vehicle's processor, enables the vehicle to perform the methods described in the first aspect and any of their possible implementations.

[0029] Sixthly, this application provides a computer program product including computer instructions that, when executed on a vehicle, cause the vehicle to perform the method described in the first aspect and any possible implementation thereof.

[0030] It should be noted that the technical effects of any of the implementation methods in aspects two through six can be found in the technical effects of the corresponding implementation methods in aspect one, and will not be repeated here.

[0031] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the composition of a start-braking creep noise optimization system provided in an embodiment of this application; Figure 2 A schematic diagram of another start-stop creep noise optimization system provided in this application embodiment; Figure 3 A flowchart illustrating a method for optimizing start-up braking creep noise provided in an embodiment of this application; Figure 4 A schematic diagram of longitudinal force balance of a vehicle provided in an embodiment of this application; Figure 5 A schematic diagram of a process for determining target braking pressure based on a noise-reduced pressure gradient model, provided for an embodiment of this application; Figure 6 A schematic diagram of pressure correction parameter curves for different target pressure correction parameters provided in an embodiment of this application; Figure 7 A schematic diagram comparing the original curve and the corrected curve of the brake push rod stroke and brake pressure provided for embodiments of this application; Figure 8 An enlarged schematic diagram of the comparison between the original curve and the corrected curve provided in the embodiments of this application; Figure 9 A state control logic diagram for a starting braking creep noise optimization method provided in this application embodiment; Figure 10 A schematic diagram of a synchronous test curve for starting and braking conditions provided in an embodiment of this application; Figure 11 A schematic diagram comparing the braking pressure-push rod stroke and pressure gradient of BBF and SCGO is provided for an embodiment of this application; Figure 12 A schematic diagram showing the comparison of start-up creep noise test results with and without SCGO function, provided in an embodiment of this application; Figure 13 This is a schematic diagram of the composition of a starting braking creep noise optimization device provided in an embodiment of this application; Figure 14 This is a schematic diagram of the composition of an electronic device provided in an embodiment of this application. Detailed Implementation

[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] It should be noted that in the embodiments of this application, the words "exemplarily" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design scheme described as "exemplarily" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the words "exemplarily" or "for example" is intended to present the relevant concepts in a specific manner.

[0035] In the embodiments of this application, the terms "first," "second," "third," "fourth," "fifth," and "sixth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," "third," "fourth," "fifth," and "sixth" may explicitly or implicitly include one or more of that feature.

[0036] In embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. For "A and / or B," this includes three combinations: A only, B only, and a combination of A and B.

[0037] During the vehicle's initial acceleration phase, as the driver engages drive and slowly releases the brake pedal, the vehicle gradually begins to creep from a standstill. During this process, the brake disc and friction pads are in a stick-slip state at extremely low relative speeds, which can easily generate creeping noise, manifesting as a perceptible "clunking" sound inside the vehicle, affecting driving comfort.

[0038] In related technologies, methods to suppress creep noise mainly include hardware solutions such as improving friction pad materials, optimizing brake disc structure, or adjusting suspension bushings. However, these solutions have drawbacks such as long development cycles, high costs, and potential sacrifice of other braking performance.

[0039] Therefore, there is an urgent need for a technical solution that can accurately and cost-effectively suppress starting and braking creep noise.

[0040] Based on this, the present invention first determines the braking pressure corresponding to the longitudinal force balance point from static to dynamic during the change of the brake push rod stroke. Using this as a benchmark, the invention determines the braking pressure to be corrected within a preset brake push rod stroke range. Subsequently, a noise-reducing pressure gradient model is used to increase the rate of change of braking pressure at this balance point with the brake push rod stroke, optimizing the gradient relationship between braking pressure and brake push rod stroke. This allows the braking pressure to quickly cross the vehicle's static-to-dynamic switching critical point, reducing fluctuations and stagnation of braking pressure near the balance point. Furthermore, braking control is achieved based on the optimized target braking pressure, effectively mitigating the impact, vibration, and friction noise of the braking mechanism during the start-up creep phase. From a control logic perspective, creep noise is suppressed, improving vehicle braking smoothness and driving quietness.

[0041] The embodiments of this application are described below with reference to the accompanying drawings.

[0042] Please see Figure 1 , Figure 1 This is a schematic diagram illustrating the composition of a start-braking creep noise optimization system provided in an embodiment of this application. The system includes a controller 101 and a data acquisition device 102. The start-braking creep noise optimization system can be a component of a vehicle; however, it can also be the vehicle itself, and this is not a limitation. The controller 101 is connected to the data acquisition device 102.

[0043] Controller 101 is the core control component of the entire start-stop creep noise optimization system. As one implementation method, please participate... Figure 2 One or more combinations of the integrated brake control unit (IBCU), vehicle control unit (VCU), and electronic stability control system (ESC) 203 can be selected, or independent dedicated control chips, microprocessors, etc. can be selected. This application does not limit the specific hardware model or specifications, as long as it can realize the control function of this application.

[0044] The controller 101 is used to execute the steps of the starting brake creep noise optimization method, specifically including: receiving various vehicle information transmitted by the data acquisition device 102; determining the braking pressure at the longitudinal force balance point of the vehicle based on parameters such as vehicle weight and slope angle; determining the preset braking push rod stroke range and the braking pressure to be corrected within the range, with the braking push rod stroke corresponding to the longitudinal force balance point as the core; calling the noise reduction pressure gradient model, constructing a pressure correction curve in combination with the target pressure correction parameters, and correcting the braking pressure to be corrected to the target braking pressure; and selecting the target braking pressure to replace the original vehicle basic braking pressure through arbitration logic, driving the braking actuator to act, thereby suppressing the starting brake creep noise.

[0045] Optionally, such as Figure 1 As shown, the data acquisition device 102 includes at least one brake pedal switch, brake push rod stroke sensor, brake master cylinder pressure sensor, wheel speed sensor, inertial measurement unit, and gear position sensor.

[0046] The data acquisition device 102 transmits the collected vehicle information to the controller 101 in real time, ensuring that the controller 101 can accurately judge the working conditions and complete various calculations and controls.

[0047] Among them, the brake pedal switch is a contact switch or inductive switch installed at the brake pedal, and is connected to the controller 101 or Figure 2 The integrated brake control unit 201 is connected. In one implementation, the brake pedal switch is used to detect whether the brake pedal is depressed and outputs a high / low level signal to provide a basis for judging the braking condition and activating the noise optimization function.

[0048] The brake push rod stroke sensor, which can be a linear displacement sensor, is installed at the brake push rod and connected to the controller 101 or... Figure 2 The integrated brake control unit 201 is connected. In one implementation, a brake push rod stroke sensor is used to detect the stroke value, stroke direction (depress / retract), and stroke change speed of the brake push rod in real time, accurately reflecting the driver's braking intention and providing core parameters for determining the preset brake push rod stroke range and judging activation conditions.

[0049] The brake master cylinder pressure sensor can be a hydraulic pressure sensor, installed inside the brake master cylinder and connected to the integrated brake control unit 201. In one implementation, the brake master cylinder pressure sensor detects the hydraulic pressure within the brake master cylinder, provides real-time feedback on the current brake pressure status, and assists in determining the starting braking condition and calibrating the target brake pressure.

[0050] Wheel speed sensors, which can be electromagnetic or Hall effect sensors, are installed at each wheel and connected to controller 101 or Figure 2The electronic stability control system 203 is connected in one embodiment. In one embodiment, wheel speed sensors are used to detect the rotational speed of each wheel and determine whether the vehicle is stationary by using the rotational speed signal, thus providing a basis for vehicle status estimation and operating condition judgment.

[0051] The inertial measurement unit, which can be a sensing unit integrating an accelerometer and a gyroscope, is installed at the center of gravity of the vehicle body and is connected to the controller 101 or Figure 2 The electronic stability control system 203 is connected in the vehicle. In one implementation, the inertial measurement unit is used to detect the vehicle's longitudinal acceleration, lateral acceleration, and angular velocity. The longitudinal acceleration is used to calculate the road slope angle, providing key data for the vehicle state estimation module 2013 to estimate the slope and longitudinal force balance point.

[0052] The gear position sensor can be a position sensor installed at the transmission, and is connected to the controller 101 or Figure 2 The vehicle control unit 202 is connected in the system. In one implementation, the gear position sensor is used to detect the current gear position of the vehicle and output a gear position signal to provide a basis for judging the starting condition and activating the noise optimization function.

[0053] In summary, the data acquisition device 102 collects multi-dimensional vehicle information such as brake pedal switch signals, brake push rod stroke, brake master cylinder pressure, wheel speed, vehicle posture, and gear position. This provides complete and reliable data support for the controller 101 to accurately identify braking and starting conditions, accurately calculate the longitudinal force balance point and corresponding braking pressure, and reliably execute the noise reduction pressure gradient model correction. This ensures that the starting braking creep noise optimization method can operate stably and accurately in different driving scenarios.

[0054] In some embodiments, based on Figure 1 As shown, please refer to Figure 2 The controller 101 may include an integrated brake control unit 201, a vehicle control unit 202, and an electronic stability control system 203.

[0055] The integrated braking control unit 201 integrates a basic braking function module 2011, a noise reduction pressure gradient model module 2012, a vehicle state estimation module 2013, and an arbitration control module 2014.

[0056] In one possible implementation, the data acquisition device 102 collects vehicle information and transmits it to the controller 101. The integrated brake control unit 201 inside the controller 101 estimates the vehicle weight, gradient, and driving force through the vehicle state estimation module 2013 based on the power torque and gear information provided by the vehicle control unit 202 and the wheel speed and inertia measurement unit information provided by the electronic stability control system 203, thereby determining the braking pressure at the longitudinal force balance point. The noise reduction pressure gradient model module 2012 constructs a pressure correction parameter curve based on the balance point pressure and calculates the target braking pressure. When the activation conditions are met, the arbitration control module 2014 selects the target braking pressure to replace the original vehicle braking pressure output by the basic braking function module 2011, and finally drives the braking actuator to reduce starting creep noise.

[0057] In one implementation, the basic braking function module 2011 is used to store the original vehicle braking requirement parameter table. This parameter table presets the mapping relationship between the brake push rod stroke and the braking pressure, and is used to output the braking pressure under normal operating conditions.

[0058] In one implementation, the noise reduction pressure gradient model module 2012 is used to determine the preset brake push rod stroke range based on the longitudinal force balance point braking pressure output by the vehicle state estimation module 2013, and then construct a pressure correction parameter curve based on the target pressure correction parameter. The braking pressure to be corrected within this range is corrected to the target braking pressure through a preset algorithm to ensure that the pressure change rate at the longitudinal force balance point meets the noise reduction requirements.

[0059] In one implementation, the vehicle state estimation module 2013 is used to estimate the vehicle's weight, slope angle, and driving force at the longitudinal force balance point based on the sensor signals transmitted by the data acquisition device 102, providing accurate parameter support for subsequent braking pressure calculation.

[0060] In one implementation, the arbitration control module 2014 is used to determine in real time whether the activation conditions of the start-up creep noise optimization function are met. When the activation conditions are met, the target braking pressure output by the noise reduction pressure gradient model module 2012 is selected to replace the conventional braking pressure output by the basic braking function module 2011. When the activation conditions are not met or the optimization task is completed, the output of the basic braking pressure is switched back to ensure braking safety and stability.

[0061] The vehicle control unit 202 is the core of the vehicle control system, integrating computing chips, communication interfaces, etc., and establishing bidirectional signal interaction with the integrated braking control unit 201.

[0062] One implementation method is used to provide vehicle power torque and gear information, and transmit the vehicle's current power output torque and gear status (forward gear, neutral gear, etc.) to the integrated brake control unit 201 in real time, providing key basis for the vehicle state estimation module 2013 to estimate the longitudinal force balance point driving force and the arbitration control module 2014 to determine the starting condition.

[0063] The electronic stability control system 203 is a dedicated electronic control unit for vehicle driving stability control. It integrates signal acquisition and processing circuits and is connected to wheel speed sensors, inertial measurement units, and integrated brake control unit 201.

[0064] In one implementation, the electronic stability control system 203 provides wheel speed information and inertial measurement unit information, and transmits inertial measurement information such as the rotational speed signal of each wheel, longitudinal acceleration, and lateral acceleration of the vehicle to the integrated braking control unit 201 in real time. This assists the vehicle state estimation module 2013 in calculating the slope angle and determining whether the vehicle is stationary, providing data support for noise optimization condition judgment.

[0065] Compared with existing hardware improvement schemes, the starting braking creep noise optimization system of this application does not require modification of the hardware structure such as brake discs and friction pads. It only optimizes the braking pressure control logic through software algorithms, which can significantly reduce the vehicle starting braking creep noise while reducing hardware modification costs. It has the characteristics of simple implementation and excellent economy.

[0066] It is understood that the embodiments of this application do not limit the structure of the start-braking creep noise optimization system and the vehicle, and may include more components or modules, such as a prompting device for displaying the status of the creep noise optimization function. The methods in the following embodiments can all be implemented in systems and vehicles with the above-described hardware structure.

[0067] For ease of understanding, the starting braking creep noise optimization method provided in this application will be described in detail below with reference to the accompanying drawings.

[0068] Figure 3 This is a flowchart illustrating a method for optimizing start-up braking creep noise, provided as an embodiment of this application. It can be applied to the controller of the aforementioned start-up braking creep noise optimization system. (Refer to...) Figure 3 The method for optimizing starting and braking creep noise includes: S301. Determine the braking pressure at the longitudinal force balance point of the vehicle.

[0069] The longitudinal force equilibrium point of a vehicle indicates the critical point at which the vehicle transitions from a stationary to a moving state as the brake lever travels. It should be understood that an increase in brake lever travel means that the distance the brake lever moves forward gradually increases after the driver releases the brake pedal (i.e., it retracts); correspondingly, a decrease in brake lever travel means that the distance the brake lever moves backward gradually decreases when the driver depresses the brake pedal. At the longitudinal force equilibrium point, the braking force on the vehicle is exactly equal to the sum of the driving force and the slope resistance, and the vehicle is in a critical state of "about to move but not yet moved."

[0070] In some embodiments, determining the braking pressure at the longitudinal force balance point of the vehicle specifically includes the following steps: S3011. Based on the driving force at the longitudinal force balance point of the vehicle, the weight of the vehicle, and the current slope information of the vehicle, determine the braking force at the longitudinal force balance point of the vehicle.

[0071] As one possible implementation, the driving force at the longitudinal force equilibrium point is obtained through interpolation using a pre-calibrated slope-driving force parameter table. One approach involves calibrating the required driving force from a stationary position to the critical point of motion under different slope conditions through real-vehicle testing, creating a table corresponding to the slope and driving force. In actual control, this table is consulted based on the current slope, and a linear interpolation method is used to obtain the equilibrium point driving force at the current slope. Specifically, the linear interpolation method includes: Current driving force = Driving force corresponding to the lower slope + (Driving force corresponding to the higher slope - Driving force corresponding to the lower slope) × (Current slope - Lower slope) / (Higher slope - Lower slope).

[0072] For example, the slope-driving force parameter table can be Table 1 as shown below.

[0073] Table 1

[0074] As one possible implementation, the vehicle weight is calculated by the vehicle state estimation module or acquired in real time by vehicle sensors. One implementation is to directly use the calculated vehicle weight when the output value of the vehicle state estimation module is valid. Another implementation is to estimate the weight based on the number of occupants identified by in-vehicle seat sensors, seatbelt sensors, or cameras, by multiplying the standard human weight by the number of occupants and adding the vehicle's curb weight, when the vehicle state estimation module is unavailable. Yet another implementation is to use a preset two-person vehicle design weight as the default value if none of the above methods are available.

[0075] As one possible implementation, the current slope information of the vehicle is calculated by the vehicle state estimation module, or by filtering and compensating the longitudinal acceleration signal collected by the inertial measurement unit. The slope information may include the slope angle θ, used to calculate the slope resistance component.

[0076] Specifically, the inertial measurement unit (IMU) acquires the vehicle's longitudinal acceleration signal in real time. This signal includes the vehicle's actual acceleration and the component of gravity along the slope. The controller simultaneously acquires the wheel speed sensor signal and differentiates it to obtain the vehicle's actual acceleration. Subtracting the actual acceleration from the longitudinal acceleration acquired by the IMU, and then applying a low-pass filter to remove high-frequency noise, yields the component of gravitational acceleration along the slope, from which the slope angle can be calculated.

[0077] As one possible implementation, a longitudinal force balance equation for the vehicle is established based on Newton's second law, whereby the braking force equals the vehicle's mass multiplied by the acceleration due to gravity, multiplied by the sine of the slope angle, plus the driving force at the longitudinal force balance point. For example, as... Figure 4 As shown, Figure 4 This application provides a schematic diagram of longitudinal force balance for a vehicle, specifically including a vehicle on a slope of... On the road surface, the component of gravity acting downwards along the slope is the total mass of the vehicle (m) multiplied by the gravitational acceleration (g) and then multiplied by the sine of the slope angle (i.e., ), driving force Along the direction of vehicle travel. At the longitudinal force equilibrium point, the braking force needs to balance both the slope resistance and the driving force.

[0078] As shown in Formula 1, the braking force at the longitudinal force equilibrium point The following relationship must be satisfied:

[0079] in, For the overall vehicle quality, It is the acceleration due to gravity. For slope angle, This is the driving force at the longitudinal force equilibrium point.

[0080] As can be seen, this implementation method can dynamically calculate the critical braking force of the vehicle from static to dynamic under the current working condition by acquiring slope, mass and driving force information in real time, providing an accurate balance point for subsequent local pressure gradient correction and avoiding the problem of poor working condition adaptability caused by fixed threshold.

[0081] S3012. Based on the braking force at the longitudinal force balance point of the vehicle, the braking pressure at the longitudinal force balance point of the vehicle is determined through the braking function relationship.

[0082] Among them, the braking function relationship is used to indicate the correspondence between the braking force at the longitudinal force balance point of the vehicle and the braking pressure at the longitudinal force balance point of the vehicle.

[0083] It should be understood that when braking pressure is converted into braking force by the brake, it is affected by the brake's geometric parameters and frictional characteristics, and there is a definite conversion coefficient between the two. This conversion coefficient is determined by the brake's structural design, and for a given vehicle, this coefficient can be pre-calibrated.

[0084] As one possible implementation, the brake performance relationship is used to convert braking force into the required braking pressure, as shown in Equation 2. The braking function relationship satisfies the following:

[0085] in, and These are the efficiency factors for the front and rear brakes, respectively. The efficiency factor indicates the efficiency with which the brake converts braking pressure into braking force. Physically, it is the ratio of the braking torque generated by a unit braking pressure on the brake disc to the effective radius of the brake disc. One implementation method is to obtain the efficiency factor through a brake bench test: under a known braking pressure, measure the braking torque generated by the brake, divide it by the braking pressure, and then divide by the effective radius of the brake disc to obtain the efficiency factor of the brake. For the same vehicle, the efficiency factors for the front and rear brakes can be fixed values, pre-stored in the controller.

[0086] and These are the effective radii of the front and rear brake discs, respectively, which are the distances from the equivalent point of application of the brake friction pad force to the center of rotation of the brake disc, expressed in meters (m). This parameter is determined by the mechanical design dimensions of the brake disc.

[0087] The braking pressure at the longitudinal force equilibrium point, in Pascals (Pa) or bar, is the target value to be determined in this step.

[0088] The basic correction factor, k, is used to compensate for changes in the friction coefficient of the friction pads under low-temperature or high-humidity conditions. Experiments show that the friction coefficient of the friction pads increases in low-temperature or high-humidity environments, resulting in greater braking force for the same braking pressure. Therefore, a basic correction factor k is introduced to correct the performance factor, typically ranging from 1.0 to 1.2. Under normal temperature and dry conditions, k can be set to 1.0; under low-temperature or high-humidity conditions, the value of k should be appropriately increased according to the actual environment.

[0089] It should be understood that, This indicates: the front brake under braking pressure Under its influence, through its efficiency factor and effective radius of brake disc The conversion generates the front wheel braking force. Similarly, This represents the rear wheel braking force. The front and rear braking forces are added together and then multiplied by a base correction factor. That is, total braking force The reason why they can be directly added and multiplied is... This is because the braking forces generated by the front and rear brakes act in parallel when the vehicle's longitudinal forces are balanced, and the total braking force equals the sum of the braking forces of each wheel; while the basic correction coefficient... Applying the same proportional correction to the front and rear braking forces reflects the consistent impact of changes in the friction coefficient on the effectiveness of the front and rear brakes.

[0090] As one possible implementation, by simultaneously solving the braking force formula (Formula 2) and the force balance equation (Formula 1), the braking pressure at the longitudinal force balance point of the vehicle can be obtained. As shown in Formula 3, the braking pressure at the longitudinal force balance point of the vehicle satisfies the following relationship:

[0091] It should be understood that this braking function relationship is used to balance the braking force required to balance the longitudinal forces of the vehicle. Converted into specific braking pressure commands This achieves an engineering mapping from "how much braking force is needed" to "how much braking pressure needs to be applied." Because this conversion is based on the actual brake parameters of the vehicle and can adjust the basic correction coefficient according to environmental conditions (temperature, humidity), the calculated equilibrium braking pressure has high accuracy, providing a reliable benchmark for subsequent local pressure gradient correction.

[0092] S302. Based on the braking pressure at the longitudinal force balance point of the vehicle, determine the braking pressure to be corrected corresponding to the preset brake push rod stroke range.

[0093] The preset brake push rod travel range is determined based on the brake push rod travel corresponding to the longitudinal force balance point. It should be understood that during the process of the driver depressing and fully releasing the brake pedal, the brake push rod travel gradually returns from its maximum value (pedal fully depressed) to its minimum value (pedal fully released). The critical point at which the vehicle begins to move from a standstill (i.e., the longitudinal force balance point) usually occurs at some intermediate travel position during this return process. Globally correcting the brake pressure mapping relationship throughout the entire return travel could affect the driver's pedal feel in different travel ranges. Therefore, this application defines a local travel range as the preset brake push rod travel range, centered on the push rod travel corresponding to the longitudinal force balance point, and only corrects the brake pressure mapping relationship within this range, thereby suppressing creep noise while maintaining the original pedal feel to the greatest extent possible.

[0094] In some embodiments, the braking pressure to be corrected corresponding to a preset brake push rod travel range is determined based on the braking pressure at the vehicle's longitudinal force balance point, specifically including the following steps: (1) Taking the braking pressure at the longitudinal force balance point as the center, increase the first calibration pressure value upward as the upper limit pressure and decrease the second calibration pressure value downward as the lower limit pressure to form the braking pressure range to be corrected.

[0095] For example, let the braking pressure at the longitudinal force equilibrium point be... The first calibrated pressure value is The second calibration pressure value is Then the upper limit pressure Lower limit pressure .in, and This is a positive number pre-determined through actual vehicle calibration, typically a few bar, to ensure that the correction range only covers a narrow pressure range near the equilibrium point. For example, in one specific embodiment, Take 5 bar. If we take 5 bar, then the correction interval is: .

[0096] (2) By interpolating the upper limit pressure and lower limit pressure from the original vehicle braking demand parameter table, the corresponding upper limit of the brake push rod stroke and lower limit of the brake push rod stroke are obtained, and the preset brake push rod stroke range is determined.

[0097] The original vehicle braking demand parameter table indicates the mapping relationship between brake lever travel and braking pressure. This table is typically stored in the controller as discrete data points, as shown in Table 2 below.

[0098] Table 2

[0099] Due to upper limit pressure and lower limit pressure The pressure value may not be exactly equal to the pressure value at a discrete point in the table, so an interpolation method is needed to obtain the corresponding stroke value. As one possible implementation method, linear interpolation is used: find two adjacent points in the table where the pressure value is exactly greater than and exactly less than the target pressure, and then calculate the corresponding stroke according to the pressure ratio.

[0100] For example, suppose the lower limit pressure Based on the original vehicle braking requirement parameter table, find two adjacent pressure values: a pressure of 15 bar corresponds to a pushrod travel of 5 mm, and a pressure of 19 bar corresponds to a pushrod travel of 5.67 mm. Then, calculate the corresponding lower limit of the travel using linear interpolation. : .

[0101] Similarly, assuming upper limit pressure In the table If this corresponds exactly to a 7mm push rod travel (no interpolation required), then the upper limit of the travel is... Therefore, the preset brake push rod travel range is... If the upper or lower pressure limit is not exactly equal to a point in Table 2, then the corresponding stroke value is calculated using linear interpolation.

[0102] It should be understood that the data in the above table is only used to illustrate one embodiment of a vehicle, and this application does not impose any specific limitations on it. In practical applications, the braking requirement parameter tables for different vehicle models and different braking systems may differ, but the preset brake push rod travel range can be determined based on the same interpolation principle.

[0103] (3) Within the preset brake push rod stroke range, obtain the brake pressure corresponding to each brake push rod stroke according to the original vehicle brake demand parameter table, and determine it as the brake pressure to be corrected.

[0104] As one possible implementation, within a preset brake push rod travel range, the braking pressure corresponding to each brake push rod travel is obtained according to the original vehicle braking demand parameter table, and determined as the braking pressure to be corrected, specifically including: For any brake push rod travel value within the preset range, firstly, find two known travel points adjacent to that travel value in the original vehicle braking demand parameter table (one less than the travel value, and one greater than the travel value). Then, using a linear interpolation method, calculate the braking pressure corresponding to the current travel value based on the braking pressure corresponding to these two known travel points. The calculation method is: the current braking pressure equals the braking pressure corresponding to the smaller travel value, plus the pressure difference between the smaller and larger travel values ​​multiplied by the offset ratio of the current travel value relative to the smaller travel value. This offset ratio is equal to (current travel value minus smaller travel value) divided by (larger travel value minus smaller travel value).

[0105] For example, assume the preset brake lever travel range is 5.335mm to 7mm. For a certain travel within this range, such as T=6mm, the braking pressure corresponding to a travel of 6mm in the original vehicle braking requirement parameter table is 22bar (already existing in the table), so 22bar is directly taken as the braking pressure to be corrected. For a travel of T=5.5mm, the adjacent points in the table are 5mm (15bar) and 5.67mm (19bar), then through linear interpolation, the current braking pressure is calculated as follows: Current braking pressure = 15bar + (5.5mm - 5mm) / (5.67mm - 5mm) × (19bar - 15bar) = 15 + 0.5 / 0.67 × 4 ≈ 15 + 2.99 = 17.99bar, approximately equal to 18bar. Similarly, the braking pressure to be corrected for each travel within the preset brake lever travel range can be obtained.

[0106] It should be understood that the braking pressure to be corrected obtained through the above method is the original mapping value of the original vehicle braking demand parameter table within this stroke range, and subsequent steps will be based on this to perform pressure gradient reconstruction and correction.

[0107] S303. Based on the noise reduction pressure gradient model and the braking pressure to be corrected corresponding to the preset braking push rod stroke range, determine the target braking pressure corresponding to the preset braking push rod stroke range.

[0108] In this embodiment, the noise reduction pressure gradient model is configured to adjust the gradient relationship between the brake pressure to be corrected and the brake push rod stroke within a preset brake push rod stroke range, such that at the longitudinal force equilibrium point, the rate of change of the target brake pressure relative to the brake push rod stroke is greater than the rate of change of the brake pressure to be corrected relative to the brake push rod stroke.

[0109] The noise reduction pressure gradient model specifically includes: the rules for determining the target pressure correction parameters, the rules for constructing the pressure correction parameter curve, and the calculation rules for calculating the target braking pressure based on the correction coefficient.

[0110] In some embodiments, please refer to Figure 5 As shown, Figure 5 This application provides a flowchart illustrating the determination of a target braking pressure based on a noise-reduced pressure gradient model. Specifically, based on the noise-reduced pressure gradient model and the braking pressure to be corrected corresponding to a preset braking push rod stroke range, the target braking pressure corresponding to the preset braking push rod stroke range is determined, including: S3031. Determine the target pressure correction parameters.

[0111] The target pressure correction parameter is the pressure correction parameter corresponding to the longitudinal force balance point of the vehicle within the preset brake push rod stroke range. One implementation method is to adaptively select this pressure correction parameter based on the slope information of the current road surface: the steeper the slope, the smaller the absolute value of the correction parameter, to avoid a forward lurch caused by an excessively rapid increase in pressure gradient during a steep start; the gentler the slope, the larger the absolute value of the correction parameter can be to achieve better noise suppression.

[0112] In some embodiments, determining the target pressure correction parameter includes: obtaining the slope information of the road surface where the vehicle is currently traveling; and selecting the target pressure correction parameter from a preset relationship table based on the slope information.

[0113] As one possible implementation, the slope information of the road surface on which the vehicle is currently traveling includes the slope angle or slope percentage. This slope information can be calculated by the vehicle state estimation module, or it can be calculated by filtering and compensating the longitudinal acceleration signal collected by the inertial measurement unit (see the relevant description in S301 for the specific calculation method, which will not be repeated here).

[0114] The preset relationship table is used to characterize the correspondence between slope information and pressure correction parameters. For example, this preset relationship table can be obtained through actual vehicle calibration, as shown in Table 3 below: Table 3

[0115] It should be understood that the values ​​in Table 3 are merely examples, and the actual values ​​need to be determined based on the specific vehicle model and calibration results. As one possible implementation method, in addition to directly looking up the table, the pressure correction parameters can be continuously calculated based on the slope using a pre-fitted functional relationship (such as a linear or polynomial function) to achieve smoother adaptive adjustment. This application does not limit the specific selection method.

[0116] S3032. Based on the target pressure correction parameters, construct the pressure correction parameter curve.

[0117] The pressure correction parameter curve is used to indicate the mapping relationship between the preset brake push rod stroke range and the pressure correction parameter.

[0118] The pressure correction parameter curve indicates the correction coefficient corresponding to different push rod positions within the preset brake push rod stroke range. It should be understood that the target pressure correction parameter only provides the correction characteristics at the longitudinal force equilibrium point (a single point), while the pressure correction parameter curve needs to describe the correction coefficient corresponding to every push rod position within the entire preset brake push rod stroke range. This curve extends smoothly to both sides of the equilibrium point, reaching extreme values ​​(minimum 0 and maximum 1) at its endpoints, thus ensuring that the corrected brake pressure at the endpoints is consistent with the original vehicle parameters.

[0119] In some embodiments, constructing a pressure correction parameter curve based on the target pressure correction parameter includes the following steps: (1) Normalize the brake push rod stroke corresponding to the preset brake push rod stroke range and determine the normalized stroke parameters.

[0120] Normalized stroke parameters refer to mapping each actual push rod stroke value within the preset brake push rod stroke range to a standardized coordinate interval in order to eliminate the differences in absolute stroke values ​​under different vehicles or different operating conditions.

[0121] One implementation method is to set the lower limit of the preset brake push rod stroke range as follows: The maximum travel distance is Then for any actual push rod stroke within this range Normalized travel parameters Calculate using the following formula: .

[0122] thus, The range of values ​​is ,in Corresponding to the lower limit of travel (maximum braking pressure). Corresponding to the upper limit of the stroke (minimum braking pressure). The pushrod stroke corresponding to the longitudinal force balance point. Mapped to It can be located between 0 and 1.

[0123] (2) Determine the segmentation coefficients of the pressure correction parameter curve based on the target pressure correction parameters. The segmentation coefficients include the position coefficient and the slope adjustment coefficient.

[0124] Among them, the position coefficient is used to determine the position of the dividing point of the piecewise quadratic function, and the slope adjustment coefficient is used to control the curvature of the curve on the two segments.

[0125] As one possible implementation, the position coefficient and slope adjustment coefficient are calculated from the target pressure correction parameter factor in the following manner: Position coefficient Slope adjustment coefficient .

[0126] The value of factor ranges from [-1, 1]. and All The number between [a certain value]. When factor is negative. The dividing point is biased towards the upper limit of the travel, making the equilibrium point near ( When the factor is smaller, it falls within the first segment of the function, and the slope of the curve in that segment is larger; when factor is positive, a < 0.5, the dividing point is biased towards the lower limit of the stroke, and the curve is relatively flat.

[0127] (3) Based on the normalized stroke parameters and segmentation coefficients, construct the pressure correction parameter curve.

[0128] The pressure correction parameter curve is used to characterize the mapping relationship between the normalized stroke parameter and the correction coefficient within the preset brake push rod stroke range. The pressure correction parameter curve is configured such that at the normalized stroke parameter position corresponding to the longitudinal force balance point, the value of the correction coefficient is such that the rate of change of the target braking pressure with the brake push rod stroke is greater than the rate of change of the braking pressure to be corrected with the brake push rod stroke.

[0129] As one possible implementation, a predefined piecewise quadratic function maps the normalized travel parameter x to a correction coefficient y. Specifically: when When using the first quadratic function: ;when When using the second quadratic function: .

[0130] The preset piecewise quadratic function satisfies: In Place, ;exist Place, ;exist At this point, the function values ​​and first derivative values ​​of both the left and right segments are continuous, ensuring a smooth curve. This is achieved by adjusting... This can change the steepness of the curve near the equilibrium point: The more negative 'a' is, the closer 'a' is to 1, the greater the curvature of the first segment of the quadratic curve, and the greater the curvature near the equilibrium point. The larger the slope when the speed is smaller, the more significant the increase in the rate of change of the corrected braking pressure with the pushrod stroke, thus enabling the vehicle to pass the longitudinal force balance point more quickly and suppressing start-up creep noise.

[0131] For example, such as Figure 6 As shown, a schematic diagram of the pressure correction parameter curves for different target pressure correction parameters is presented. Figure 6In the diagram, the horizontal axis x represents the normalized stroke parameter (linearly mapping the preset brake push rod stroke range to the [0,1] interval), and the vertical axis y represents the correction coefficient (dimensionless). When the target pressure correction parameter factor takes different values ​​within the [-1,1] interval, the pressure correction parameter curve changes as follows: When factor is negative, the boundary point shifts towards the upper limit of the stroke, the curvature of the first quadratic curve increases, and the curve is steeper when x is small. This corresponds to a significant increase in the slope of the correction coefficient near the longitudinal force balance point as the normalized stroke parameter changes. When factor is positive, the boundary point shifts towards the lower limit of the stroke, and the curve becomes generally flatter. When factor=0, the curve is symmetrical. All curves satisfy the boundary condition that the correction coefficient is 0 at x=0 and 1 at x=1, and the function value and first derivative are continuous at the boundary point, ensuring a smooth transition in the correction process. By adjusting the value of factor, the steepness of the correction curve near the equilibrium point can be flexibly controlled, thereby achieving precise adjustment of the target braking pressure gradient. This ensures that the rate of change of the corrected target braking pressure with the brake push rod stroke is greater than the rate of change before correction, thus suppressing starting creep noise.

[0132] S3033. Based on the brake pressure to be corrected and the pressure correction parameter curve corresponding to the preset brake push rod stroke range, determine the target brake pressure corresponding to the preset brake push rod stroke range.

[0133] As one possible implementation, the target braking pressure corresponding to the preset brake push rod stroke range is determined based on the braking pressure to be corrected and the pressure correction parameter curve corresponding to the preset brake push rod stroke range, including: (1) Obtain the braking pressure to be corrected corresponding to the lower limit endpoint of the preset brake push rod stroke range as the lower limit pressure, and the braking pressure to be corrected corresponding to the upper limit endpoint of the preset brake push rod stroke range as the upper limit pressure.

[0134] As one possible implementation, the braking pressure to be corrected corresponding to the lower limit endpoint of the preset brake push rod stroke range is obtained as the lower limit pressure. The upper limit pressure is the braking pressure to be corrected corresponding to the upper limit endpoint. These two pressure values ​​can be directly read from the original vehicle braking requirement parameter table, and they correspond to the stroke respectively. and .

[0135] (2) For any brake push rod stroke within the preset brake push rod stroke range, the corresponding correction coefficient is obtained from the pressure correction parameter curve based on the normalized position of any brake push rod stroke within the preset brake push rod stroke range.

[0136] As one possible implementation, for any brake push rod stroke within the preset brake push rod stroke range According to the normalized position of the journey within the range. The corresponding correction coefficient can be obtained by querying the existing pressure correction parameter curve. The query method can use a pre-calculated two-dimensional table for interpolation, or directly calculate in real time according to a preset piecewise quadratic function.

[0137] (3) Based on the lower limit pressure, the upper limit pressure and the corresponding correction coefficient, determine the target braking pressure within the preset braking push rod stroke range.

[0138] For example, the target braking pressure is calculated based on the lower limit pressure, the upper limit pressure, and the correction factor. The calculation formula is: This formula guarantees that in hour ,exist hour This means that the corrected curve coincides with the original curve at its endpoints. This is because the corrected curve has a larger rate of change near the longitudinal force equilibrium point (designed in a region with a steep slope). Therefore, when the push rod travels through the equilibrium point, Rapid changes led to The vehicle descends rapidly, allowing it to quickly pass the critical point and effectively suppress creep noise.

[0139] For example, suppose , ,correspond , Taking factor = -0.6, the equilibrium point is designed at... place (i.e.) Then the correction factor Target pressure The original vehicle's brake pressure at this point, which needs correction, can be interpolated from the table to approximately 25 bar (assuming), and the corrected pressure will be even lower. When the pushrod travels from... Increase to hour, The rate of change increased from approximately 0.12 to approximately 0.28. The factor is approximately 1.6, which is much larger than 1 for the linear mapping, thus significantly increasing the pressure gradient. It should be understood that in practical applications, the optimal factor and equilibrium point location need to be determined through actual vehicle calibration; this application does not impose such limitations.

[0140] For example, such as Figure 7 As shown, the Figure 7This diagram illustrates the comparison between the original and corrected curves of the brake push rod travel and brake pressure. The target pressure correction coefficient is factor = -0.6. The horizontal axis represents the brake push rod travel T (mm), and the vertical axis represents the brake pressure P (bar). The dashed line represents the original brake pressure curve, and the solid line represents the brake pressure curve corrected by the method described in this application. The diagram also marks the original and corrected points corresponding to the preset brake push rod travel range: the lower limit T_lower = 5.67mm, the upper limit T_upper = 8.60mm, and the longitudinal force balance point T_balance = 7.60mm. As can be seen from the diagram, within the critical range from T_lower to T_upper, the slope of the corrected curve is significantly higher than the original curve. This achieves a gradient increase in brake pressure near the balance point, enabling the vehicle to quickly pass the longitudinal force balance point and avoid prolonged stay in this range, thereby suppressing the generation of starting creep noise. Figure 8 The above, Figure 8 An enlarged schematic diagram of the comparison between the original curve and the corrected curve provided in this application embodiment is specifically based on... Figure 7 An enlarged diagram showing the comparison between the original curve and the corrected curve; the internal logic is as described above and will not be repeated here.

[0141] Through the above method, this application realizes the reconstruction of the braking pressure mapping relationship only within a local travel range, and the reconstruction curve is seamlessly connected with the original vehicle at the endpoint, and a higher pressure gradient is obtained near the equilibrium point, thereby suppressing creep noise while maintaining the consistency of pedal feel under other working conditions.

[0142] S304. Drive vehicle braking based on target braking pressure to reduce creep noise during the brake lever stroke.

[0143] After determining the target braking pressure corresponding to each push rod stroke within the preset brake push rod stroke range via S303, the controller outputs the real-time calculated target braking pressure as a braking command to the brake actuator (e.g., the hydraulic adjustment module or electronic booster in the integrated brake control unit). Based on the received target braking pressure value, the brake actuator adjusts the hydraulic pressure applied to each wheel brake cylinder, thereby replacing the original braking pressure determined by the original vehicle braking demand parameter table.

[0144] Because the rate of change of the target braking pressure with the brake push rod travel is greater than the rate of change of the original braking pressure to be corrected near the longitudinal force equilibrium point, the braking pressure can drop rapidly when the driver slowly releases the brake pedal and the push rod travels through the equilibrium point area. This allows the vehicle to quickly pass the critical state from static to dynamic, significantly shortening the stick-slip duration between the brake disc and friction pads, thereby effectively suppressing the generation of starting creep noise. Simultaneously, since the braking system still outputs pressure according to the original vehicle braking requirement parameter table outside the preset brake push rod travel range and when the function is not activated, it will not adversely affect the brake pedal feel under other operating conditions.

[0145] Through the above methods, this application achieves adaptive optimization of start-up creep noise while maintaining the consistency of the original vehicle's brake pedal feel, thereby improving the vehicle's driving comfort.

[0146] In some embodiments, the starting braking creep noise optimization method further includes: when the vehicle does not meet a first preset condition and / or the vehicle does not meet a second preset condition, controlling the vehicle to brake with a braking pressure to be corrected corresponding to a preset brake push rod stroke range.

[0147] The first preset conditions include: the brake pedal switch is on, the vehicle is stationary, the gear is in forward gear, and the slope information is within the set range.

[0148] The second preset conditions include: the direction of the brake push rod stroke is retracting, the retraction speed of the brake push rod stroke is greater than or equal to a set threshold, and the brake master cylinder pressure is less than or equal to a first pressure threshold.

[0149] It should be understood that if any of the above conditions are not met, it indicates that the vehicle is not currently in a typical starting creep noise-prone condition. For example, scenarios such as the driver not pressing the brake pedal, the vehicle not being stationary, the gear not being in a forward gear, the incline exceeding the set range, or the brake lever not retracting slowly, retracting too slowly or too quickly, or the master cylinder pressure being too high, do not fall under the category of scenarios requiring the activation of the noise reduction pressure gradient model. In these cases, to ensure the consistency and safety of the braking system's response, the vehicle is controlled to brake using the corrected braking pressure determined by the original vehicle braking demand parameter table, i.e., restoring the original braking pressure-stroke mapping relationship before correction. This avoids unnecessary functional intervention and ensures that the driver's pedal feel is not affected under other operating conditions.

[0150] In another embodiment, when the vehicle meets the first preset condition, the vehicle is controlled to brake with a braking pressure to be corrected corresponding to the preset brake push rod travel range.

[0151] In this embodiment, when the first preset condition is met (i.e., the brake pedal switch is open, the vehicle is stationary, the gear is in drive, and the slope is within the set range), the vehicle enters the standby state of the start-up creep noise optimization function. In this state, although it has been identified that the vehicle may be about to enter a creep start condition, since the driver has not yet started to release the brake pedal (i.e., the second preset condition has not been met), the original braking pressure to be corrected is still temporarily used for braking. This design can avoid frequent switching of control strategies near the critical point of the operating condition, ensure the continuity of braking pressure, and at the same time prepare for the subsequent activation of correction.

[0152] In another embodiment, when the vehicle meets the second preset condition, the vehicle is controlled to brake with a braking pressure to be corrected corresponding to the preset brake push rod travel range.

[0153] This embodiment applies to the following scenario: the second preset condition is met (i.e., the brake push rod travel direction is retracting, the retraction speed is greater than or equal to a set threshold, and the master cylinder pressure is less than or equal to a first pressure threshold), but some items in the first preset condition are not met (e.g., the gear is not in a forward gear, the vehicle is not completely stationary, etc.). In this case, because the starting condition is incomplete, the noise reduction pressure gradient model has not been fully activated, so the original vehicle's braking pressure to be corrected is still used for braking. This ensures the rigor of the function activation logic, and the correction strategy is only activated when all preset conditions are met, avoiding incorrect intervention under unexpected conditions.

[0154] In some embodiments, the starting braking creep noise optimization method further includes: redetermining the target pressure correction parameter when the rate of change of the target braking pressure relative to the brake push rod stroke is less than or equal to the rate of change of the braking pressure to be corrected relative to the brake push rod stroke.

[0155] It should be understood that increasing the pressure gradient near the longitudinal force equilibrium point ensures that the rate of change of the target braking pressure with the push rod stroke is greater than the rate of change of the original braking pressure to be corrected. If, after correction, the pressure gradient at the equilibrium point is less than or equal to the original gradient, it indicates that the selected target pressure correction parameter (e.g., factor) or the calibration values ​​of the correction interval boundaries (ΔP_upper, ΔP_lower) are unreasonable, failing to achieve the expected noise optimization effect. In this case, the controller can issue a calibration prompt or automatically adjust the parameters (e.g., change the factor or ΔP value), reconstruct the pressure correction parameter curve, and recalculate the target braking pressure until the condition of a rate of change greater than the original rate of change is met. This mechanism ensures the effectiveness and robustness of the noise reduction pressure gradient model, avoiding functional failure or performance degradation due to improper parameter settings.

[0156] For example, as shown below Figure 9 As shown, Figure 9This application provides a state control logic diagram for a starting braking creep noise optimization method. Figure 9 The system demonstrates three operating states: hibernation, standby, and activation, and their switching relationships. The system defaults to hibernation. When the vehicle meets the first preset condition (brake pedal switch open, vehicle stationary, gear in drive, and slope within a set range), it switches from hibernation to standby. In standby, if the system further detects that the vehicle simultaneously meets the second preset condition (brake lever travel direction is retracting, retraction speed is greater than or equal to a set threshold, and brake master cylinder pressure is less than or equal to a first pressure threshold), it switches to activation and executes the target brake pressure correction strategy. Conversely, if the vehicle does not meet the second preset condition, the system returns from activation to standby. When the vehicle does not meet the first preset condition or the function completes its normal exit, the system can return from standby or activation to hibernation. This achieves orderly start / stop and closed-loop control of functions, ensuring rigorous condition identification and avoiding erroneous intervention under unexpected conditions, thus ensuring consistent braking system response and unaffected driver pedal feel.

[0157] In summary, to verify the generation mechanism of creep noise during start-up and braking, this application conducted synchronous tests under real vehicle operating conditions. For example, as shown... Figure 10 As shown, in the synchronous test curve of the starting and braking condition, the horizontal axis represents time (unit: s), the left vertical axis represents the starting creep noise test decibel value (unit: dB(A)), and the right vertical axis represents the braking pressure (unit: bar) and vehicle longitudinal acceleration (unit: g), respectively. The thick black line is the braking pressure curve. During the period from about 46.0s to 57.0s, the braking pressure slowly decreases from about 26 bar to 2 bar, and the pressure relief gradient is gentle. The corresponding gray starting creep noise test decibel value curve shows multiple obvious peaks in the range from about 54.0s to 56.5s, with the peak value close to 49dB(A), which is much higher than the background noise level of about 30-40dB(A) in the preceding and following ranges. At the same time, the light gray vehicle longitudinal acceleration curve also shows small oscillations, which intuitively reflects the vehicle vibration and noise caused by the repeated stick-slip phenomenon of the braking friction pair. In summary, the slower the pressure relief gradient, the greater the starting creep noise and the longer the duration. It is also prone to multiple creep cycles that generate continuous starting creep noise. The fixed pressure relief curve in traditional control strategies is difficult to effectively suppress this condition. This application proposes a targeted optimization scheme based on this mechanism.

[0158] To more intuitively illustrate the effect of the starting braking creep noise optimization method of this application on the adjustment of the braking pressure gradient, for example, as shown... Figure 11As shown, the figure contains two sets of comparison curves, intuitively demonstrating the optimization effects of the proposed start-braking creep noise optimization method and the traditional Base Brake Function (BBF) control strategy on brake push rod stroke-brake pressure and pressure relief gradient: The upper figure shows the comparison curves of BBF and SCGO brake push rod stroke-brake pressure, where the dark curve is the stroke-pressure curve under the original BBF control, and the light curve is the curve after SCGO optimization. The two show significant differences near the longitudinal force balance point in the SCGO working area; the lower figure shows the comparison curves of BBF and SCGO pressure relief gradient, where when factor=-0.6, the original driver braking demand (Driver Brake) of BBF is... The pressure gradient of the original BBF DBR at the pressure equilibrium point is 7.12 Bar / mm, while that of the SCGO-corrected DBR is 27.30 Bar / mm. The pressure gradient of the SCGO at the pressure equilibrium point is 3.83 times that of the original BBF DBR, which greatly improves the rate of change of braking pressure. This allows the vehicle to quickly pass the longitudinal force equilibrium point and avoids multiple stick-slip phenomena caused by slow pressure release, thereby effectively suppressing start-up creep noise.

[0159] To verify the actual noise reduction effect of the Start Creep Groan Optimization (SCGO) method in this application, comparative tests were conducted with and without SCGO under the same start-braking conditions. Figure 12 As shown in the comparison chart of the whole vehicle start-up creep noise test results with and without SCGO, it is clear that under the same start-up and braking conditions, the results of three repeated tests and the average value all show that: when the SCGO function is not enabled, the average sound pressure level of the start-up creep noise at the driver's ear is 54.8 dBA, with single test values ​​of 54.2 dBA, 55.4 dBA and 54.6 dBA, respectively; after enabling the SCGO function, the average sound pressure level of the start-up creep noise at the driver's ear is significantly reduced to 51.4 dBA, with single test values ​​reduced to 50.7 dBA, 52.1 dBA and 51.3 dBA, respectively, with an average sound pressure level reduction of 3.4 dBA, which is an optimization improvement of 6.6%. This verifies that the start-up and braking creep noise optimization method proposed in this application can effectively suppress creep noise during vehicle start-up and significantly improve driving comfort.

[0160] The above mainly describes the solution provided by the embodiments of this application from a methodological perspective. To achieve the above functions, the starting and braking creep noise optimization device includes corresponding hardware structures and / or software modules for executing each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0161] This application embodiment can, based on the above method, exemplarily divide the starting and braking creep noise optimization device or electronic device into functional modules. For example, the starting and braking creep noise optimization device or electronic device may include functional modules corresponding to each functional division, or two or more functions may be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division; in actual implementation, there may be other division methods.

[0162] Please see Figure 13 The present application provides a starting braking creep noise optimization device, which includes: a critical point determination module 1301, a determination module 1302, a correction module 1303, and a braking module 1304.

[0163] The critical point determination module 1301 is used to: determine the braking pressure at the longitudinal force balance point of the vehicle; the longitudinal force balance point of the vehicle is used to indicate the critical point state of the vehicle from static to dynamic as the travel of the vehicle's brake push rod changes; the determination module 1302 is used to: determine the braking pressure to be corrected corresponding to a preset brake push rod travel range based on the braking pressure at the longitudinal force balance point of the vehicle; wherein, the preset brake push rod travel range is determined based on the brake push rod travel corresponding to the longitudinal force balance point; the correction module 1303 is used to: determine the target braking pressure corresponding to the preset brake push rod travel range based on a noise reduction pressure gradient model and the braking pressure to be corrected corresponding to the preset brake push rod travel range; the noise reduction pressure gradient model is configured to adjust the gradient relationship between the braking pressure to be corrected and the brake push rod travel in the preset brake push rod travel range, such that at the longitudinal force balance point, the rate of change of the target braking pressure relative to the brake push rod travel is greater than the rate of change of the braking pressure to be corrected relative to the brake push rod travel; the braking module 1304 is used to: drive the vehicle to brake based on the target braking pressure to reduce the creep noise of the vehicle during the brake push rod travel.

[0164] In some embodiments, the correction module 1303 is specifically used to: determine the target braking pressure corresponding to the preset braking push rod travel range based on the noise reduction pressure gradient model and the braking pressure to be corrected corresponding to the preset braking push rod travel range, including: determining the target pressure correction parameter; the target pressure correction parameter is the correction parameter corresponding to the longitudinal force balance point of the vehicle in the preset braking push rod travel range; constructing a pressure correction parameter curve based on the target pressure correction parameter, the pressure correction parameter curve being used to indicate the mapping relationship between the preset braking push rod travel range and the pressure correction parameter; and determining the target braking pressure corresponding to the preset braking push rod travel range based on the braking pressure to be corrected corresponding to the preset braking push rod travel range and the pressure correction parameter curve.

[0165] In some embodiments, the correction module 1303 is specifically used to: determine the target braking pressure corresponding to the preset braking push rod stroke range based on the braking pressure to be corrected and the pressure correction parameter curve corresponding to the preset braking push rod stroke range, including: obtaining the braking pressure to be corrected corresponding to the lower limit endpoint of the preset braking push rod stroke range as the lower limit pressure, and the braking pressure to be corrected corresponding to the upper limit endpoint of the preset braking push rod stroke range as the upper limit pressure; for any braking push rod stroke within the preset braking push rod stroke range, obtaining the corresponding correction coefficient from the pressure correction parameter curve according to the normalized position of any braking push rod stroke within the preset braking push rod stroke range; and determining the target braking pressure within the preset braking push rod stroke range based on the lower limit pressure, the upper limit pressure, and the corresponding correction coefficient.

[0166] In some embodiments, the determining module 1302 is specifically used to: determine the target pressure correction parameter, including: obtaining the slope information of the road surface where the vehicle is currently driving; and selecting the target pressure correction parameter from a preset relationship table based on the slope information, wherein the preset relationship table is used to characterize the correspondence between the slope information and the pressure correction parameter.

[0167] In some embodiments, the correction module 1303 is specifically used to: construct a pressure correction parameter curve based on the target pressure correction parameter, including: normalizing the brake push rod stroke corresponding to the preset brake push rod stroke range to determine the normalized stroke parameter; determining the segmentation coefficient of the pressure correction parameter curve according to the target pressure correction parameter, the segmentation coefficient including the position coefficient and the slope adjustment coefficient; constructing the pressure correction parameter curve based on the normalized stroke parameter and the segmentation coefficient; the pressure correction parameter curve is used to characterize the mapping relationship between the normalized stroke parameter and the correction coefficient within the preset brake push rod stroke range, and the pressure correction parameter curve is configured such that at the normalized stroke parameter position corresponding to the longitudinal force balance point, the value of the correction coefficient makes the rate of change of the target brake pressure with the brake push rod stroke greater than the rate of change of the brake pressure to be corrected with the brake push rod stroke.

[0168] In some embodiments, the determining module 1302 is specifically used to: determine the braking pressure at the longitudinal force balance point of the vehicle, including: determining the braking force at the longitudinal force balance point of the vehicle based on the driving force at the longitudinal force balance point of the vehicle, the weight of the vehicle, and the current slope information of the vehicle; and determining the braking pressure at the longitudinal force balance point of the vehicle based on the braking force at the longitudinal force balance point of the vehicle through a braking function relationship, wherein the braking function relationship is used to indicate the correspondence between the braking force at the longitudinal force balance point of the vehicle and the braking pressure at the longitudinal force balance point of the vehicle.

[0169] In some embodiments, the determining module 1302 is specifically used to: determine the brake pressure to be corrected corresponding to a preset brake push rod travel range based on the brake pressure at the vehicle's longitudinal force balance point, including: taking the brake pressure at the longitudinal force balance point as the center, increasing the first calibrated pressure value upward as the upper limit pressure, and decreasing the second calibrated pressure value downward as the lower limit pressure, to form a brake pressure range to be corrected; interpolating the upper limit pressure and lower limit pressure respectively through the original vehicle brake demand parameter table to obtain the corresponding upper limit and lower limit of the brake push rod travel, and determining the preset brake push rod travel range; wherein, the original vehicle brake demand parameter table is used to indicate the mapping relationship between the brake push rod travel and the brake pressure; within the preset brake push rod travel range, obtaining the brake pressure corresponding to each brake push rod travel according to the original vehicle brake demand parameter table, and determining it as the brake pressure to be corrected.

[0170] In some embodiments, the braking module 1304 is specifically used for: the method of this application further includes: when the vehicle does not meet a first preset condition and / or the vehicle does not meet a second preset condition, controlling the vehicle to brake with a braking pressure to be corrected corresponding to a preset brake lever travel range. The first preset condition includes: the brake pedal switch is open, the vehicle is stationary, the gear is in forward gear, and the slope information is within a set range; the second preset condition includes: the brake lever travel direction is retracting, the brake lever travel retraction speed is greater than or equal to a set threshold, and the brake master cylinder pressure is less than or equal to a first pressure threshold.

[0171] In some embodiments, the braking module 1304 is specifically used for: the method of this application further includes: redetermining the target pressure correction parameter when the rate of change of the target braking pressure relative to the brake push rod stroke is less than or equal to the rate of change of the braking pressure to be corrected relative to the brake push rod stroke.

[0172] This application provides another starting brake creep noise optimization device, which includes: a data acquisition module, a function wake-up module, a function activation module, a slope adaptive balance pressure calculation module, a biquadratic function DBR reconstruction module, and a pressure gradient calculation module. The data acquisition module collects vehicle data; the function wake-up module determines whether to wake up the SCGO function based on whether the vehicle meets a first preset condition; the function activation module determines whether to activate the SCGO function based on whether the vehicle meets a second preset condition; the slope adaptive balance pressure calculation module calculates the braking pressure of the vehicle to the balance point when acquiring different slope information; the biquadratic function DBR reconstruction module calculates the target braking pressure for the SCGO function execution; and the pressure gradient calculation module calculates the pressure gradient at the balance point and determines whether the calibration parameter settings are reasonable. The calibration parameter settings refer to adjustable parameters (such as target pressure correction parameters, position coefficients, slope adjustment coefficients, etc.) used to control the pressure gradient correction intensity in the SCGO function. The pressure gradient calculation module determines whether these parameters are reasonable by comparing the actual and expected pressure change rates.

[0173] It should be understood that the module indication sections in the device of this application are merely examples and do not limit the scope of protection of this application.

[0174] like Figure 14 As shown, the electronic device 1400 provided in this application embodiment includes, but is not limited to, a processor 1401 and a memory 1402.

[0175] The memory 1402 described above is used to store the executable instructions of the processor 1401. It is understood that the processor 1401 is configured to execute instructions to implement the vehicle battery level testing method described in the above embodiment.

[0176] It should be noted that those skilled in the art will understand that Figure 14 The electronic device structure shown does not constitute a limitation on electronic device 1400; electronic device may include, but is not limited to, other electronic devices. Figure 14 This may indicate more or fewer components, or combinations of certain components, or different component arrangements.

[0177] Processor 1401 is the control center of electronic device 1400. It connects various parts of the electronic device via various interfaces and lines. By running or executing software programs and / or modules stored in memory 1402, and by calling data stored in memory 1402, it performs various functions and processes data of electronic device 1400, thereby providing overall monitoring of electronic device 1400. Processor 1401 may include one or more processing units. Optionally, processor 1401 may integrate an application processor and a modem processor. The application processor mainly handles the operating system, user interface, and applications, while the modem processor mainly handles wireless communication. It is understood that the modem processor may not be integrated into processor 1401.

[0178] The memory 1402 can be used to store software programs and various data. The memory 1402 may primarily include a program storage area and a data storage area. The program storage area may store the operating system, application programs required by at least one functional module (such as a determination unit, processing unit, etc.), etc. Furthermore, the memory 1402 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0179] In an exemplary embodiment, a computer-readable storage medium including instructions is also provided, such as a memory 1402 including instructions, which can be executed by a processor 1401 of an electronic device 1400 to implement the methods in the above embodiments.

[0180] Optionally, the computer-readable storage medium may be a non-transitory computer-readable storage medium, such as a read-only memory (ROM), random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device.

[0181] In an exemplary embodiment, this application also provides a computer program product including one or more instructions, which can be executed by the processor 1401 of the electronic device 1400 to perform the methods described above.

[0182] It should be noted that when one or more instructions in the computer-readable storage medium or computer program product are executed by the processor of an electronic device, they implement the various processes of the above method embodiments and achieve the same technical effect as the above method. To avoid repetition, they will not be described again here.

[0183] Through the above description of the embodiments, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0184] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another apparatus, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0185] The units described as separate components may or may not be physically separate. A component shown as a unit can be one or more physical units; that is, it can be located in one place or distributed in multiple different locations. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0186] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0187] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, essentially, or the parts that contribute to related technologies, or all or part of the technical solutions, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0188] The above embodiments are merely preferred embodiments provided to fully illustrate this application, and the scope of protection of this application is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on this application are all within the scope of protection of this application.

Claims

1. A method for optimizing starting and braking creep noise, characterized in that, Applied to vehicles, the method includes: The braking pressure at the longitudinal force balance point of the vehicle is determined; the longitudinal force balance point of the vehicle is used to indicate the critical point state of the vehicle from static to dynamic as the travel of the vehicle's brake push rod changes. Based on the braking pressure at the longitudinal force balance point of the vehicle, the braking pressure to be corrected corresponding to a preset brake push rod travel range is determined; wherein, the preset brake push rod travel range is determined based on the brake push rod travel corresponding to the longitudinal force balance point. Based on the noise reduction pressure gradient model and the braking pressure to be corrected corresponding to the preset brake push rod stroke range, the target braking pressure corresponding to the preset brake push rod stroke range is determined; the noise reduction pressure gradient model is configured to adjust the gradient relationship between the braking pressure to be corrected and the brake push rod stroke within the preset brake push rod stroke range, such that at the longitudinal force balance point, the rate of change of the target braking pressure relative to the brake push rod stroke is greater than the rate of change of the braking pressure to be corrected relative to the brake push rod stroke. The vehicle is braked based on the target braking pressure to reduce the creep noise of the vehicle during the brake lever stroke.

2. The method according to claim 1, characterized in that, The process of determining the target braking pressure corresponding to the preset braking push rod stroke range based on the noise reduction pressure gradient model and the braking pressure to be corrected corresponding to the preset braking push rod stroke range includes: Determine the target pressure correction parameter; the target pressure correction parameter is the correction parameter corresponding to the longitudinal force balance point of the vehicle within the preset brake push rod stroke range; Based on the target pressure correction parameters, a pressure correction parameter curve is constructed, which is used to indicate the mapping relationship between the preset brake push rod stroke range and the pressure correction parameters. Based on the braking pressure to be corrected corresponding to the preset brake push rod stroke range and the pressure correction parameter curve, the target braking pressure corresponding to the preset brake push rod stroke range is determined.

3. The method according to claim 2, characterized in that, The step of determining the target braking pressure corresponding to the preset braking push rod stroke range based on the braking pressure to be corrected corresponding to the preset braking push rod stroke range and the pressure correction parameter curve includes: The braking pressure to be corrected corresponding to the lower limit endpoint of the preset brake push rod stroke range is obtained as the lower limit pressure, and the braking pressure to be corrected corresponding to the upper limit endpoint of the preset brake push rod stroke range is obtained as the upper limit pressure. For any brake push rod stroke within the preset brake push rod stroke range, the corresponding correction coefficient is obtained from the pressure correction parameter curve based on the normalized position of any brake push rod stroke within the preset brake push rod stroke range. Based on the lower limit pressure, the upper limit pressure, and the corresponding correction coefficient, the target braking pressure within the preset brake push rod stroke range is determined.

4. The method according to claim 2, characterized in that, The determination of the target pressure correction parameters includes: Obtain the slope information of the road surface on which the vehicle is currently traveling; Based on the slope information, the target pressure correction parameter is selected from a preset relationship table, which is used to characterize the correspondence between slope information and pressure correction parameter.

5. The method according to claim 2, characterized in that, Based on the target pressure correction parameters, a pressure correction parameter curve is constructed, including: The brake push rod stroke corresponding to the preset brake push rod stroke range is normalized to determine the normalized stroke parameters; Based on the target pressure correction parameters, the segmentation coefficients of the pressure correction parameter curve are determined, and the segmentation coefficients include position coefficients and slope adjustment coefficients. Based on the normalized stroke parameter and the segmentation coefficient, the pressure correction parameter curve is constructed. The pressure correction parameter curve is used to characterize the mapping relationship between the normalized stroke parameter and the correction coefficient within the preset brake push rod stroke range. The pressure correction parameter curve is configured such that, at the normalized stroke parameter position corresponding to the longitudinal force balance point, the value of the correction coefficient is such that the rate of change of the target braking pressure with the brake push rod stroke is greater than the rate of change of the braking pressure to be corrected with the brake push rod stroke.

6. The method according to claim 1, characterized in that, The braking pressure used to determine the longitudinal force balance point of the vehicle includes: Based on the driving force at the longitudinal force balance point of the vehicle, the weight of the vehicle, and the current slope information of the vehicle, the braking force at the longitudinal force balance point of the vehicle is determined. Based on the braking force at the longitudinal force balance point of the vehicle, the braking pressure at the longitudinal force balance point of the vehicle is determined through a braking function relationship, wherein the braking function relationship is used to indicate the correspondence between the braking force at the longitudinal force balance point of the vehicle and the braking pressure at the longitudinal force balance point of the vehicle.

7. The method according to claim 1, characterized in that, Based on the braking pressure at the longitudinal force balance point of the vehicle, determine the braking pressure to be corrected corresponding to the preset brake push rod travel range, including: With the braking pressure at the longitudinal force balance point as the center, the first calibrated pressure value is increased upward as the upper limit pressure, and the second calibrated pressure value is decreased downward as the lower limit pressure, thus forming the braking pressure range to be corrected. By interpolating the upper limit pressure and the lower limit pressure from the original vehicle braking demand parameter table, the corresponding upper limit and lower limit of the brake push rod stroke are obtained, and the preset brake push rod stroke range is determined; wherein, the original vehicle braking demand parameter table is used to indicate the mapping relationship between the brake push rod stroke and the braking pressure; Within the preset brake push rod stroke range, the braking pressure corresponding to each brake push rod stroke is obtained according to the original vehicle braking demand parameter table, and determined as the braking pressure to be corrected.

8. The method according to claim 1, characterized in that, The method further includes: When the vehicle does not meet the first preset condition and / or the vehicle does not meet the second preset condition, the vehicle is controlled to brake with the braking pressure to be corrected corresponding to the preset brake push rod stroke range; The first preset conditions include: the brake pedal switch is on, the vehicle is stationary, the gear is forward, and the slope information is within a set range; the second preset conditions include: the brake push rod travel direction is retracting, the brake push rod travel retraction speed is greater than or equal to a set threshold, and the brake master cylinder pressure is less than or equal to a first pressure threshold.

9. The method according to claim 2, characterized in that, The method further includes: If the rate of change of the target braking pressure relative to the brake push rod stroke is less than or equal to the rate of change of the braking pressure to be corrected relative to the brake push rod stroke, the target pressure correction parameter is re-determined.

10. A device for optimizing starting and braking creep noise, characterized in that, The device includes: The critical point determination module is used to: determine the braking pressure at the longitudinal force balance point of the vehicle; the longitudinal force balance point of the vehicle is used to indicate the critical point state of the vehicle from static to dynamic as the travel of the vehicle's brake push rod changes. The determining module is used to: determine the braking pressure to be corrected corresponding to a preset brake push rod stroke range based on the braking pressure at the longitudinal force balance point of the vehicle; wherein, the preset brake push rod stroke range is determined based on the brake push rod stroke corresponding to the longitudinal force balance point; The correction module is used to: determine the target braking pressure corresponding to the preset braking push rod stroke range based on the noise reduction pressure gradient model and the braking pressure to be corrected corresponding to the preset braking push rod stroke range; the noise reduction pressure gradient model is configured to adjust the gradient relationship between the braking pressure to be corrected and the braking push rod stroke within the preset braking push rod stroke range, such that at the longitudinal force balance point, the rate of change of the target braking pressure relative to the braking push rod stroke is greater than the rate of change of the braking pressure to be corrected relative to the braking push rod stroke; The braking module is used to: drive the vehicle to brake based on the target braking pressure, so as to reduce the creep noise of the vehicle during the brake lever stroke.

11. A vehicle, characterized in that, The vehicle includes a processor and a memory for storing processor-executable instructions; wherein the processor is configured to execute the instructions to implement the method as described in any one of claims 1 to 9.

12. A computer-readable storage medium, characterized in that, When the computer-executable instructions stored in the computer-readable storage medium are executed by the processor of the electronic device, the electronic device is capable of performing the method as described in any one of claims 1 to 9.

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