Braking sound acquisition method, device and system

Abstract

The embodiment of the invention discloses a braking sound acquisition method, device and system, and belongs to the technical field of vehicle testing. The method comprises the following steps: controlling an environment bin to set a test environment, wherein the test environment comprises environment humidity and environment temperature; in the testing environment, the driving motor is controlled to output torque based on a testing working condition, a brake caliper of the hydraulic brake is controlled to brake, and the testing working condition is used for simulating the working condition of the vehicle during hill starting; under the condition that the state of the brake disc conforms to the test working condition, brake sound collected by the microphone is obtained, and the brake sound is generated by friction between the to-be-tested brake pad and the brake disc. By adopting the technical scheme provided by the embodiment of the invention, the accuracy of a braking sound acquisition result can be improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of vehicle testing technology, and in particular to a brake sound collection method, device and system. Background Art

[0002] The braking sound (Groan sound) of the vehicle when starting has a great impact on the comfort of the vehicle. In the related art, the vehicle is manually operated to creep at a low speed, and the driver subjectively evaluates the braking sound.

[0003] However, the whole vehicle Groan sound detection is carried out outdoors and is greatly affected by the ambient temperature and humidity, which can easily lead to deviations in the braking sound collection results. Summary of the invention

[0004] The embodiments of the present application provide a braking sound collection method, device and system, and the technical solution includes the following contents.

[0005] On the one hand, an embodiment of the present application provides a brake sound collection method, the method is used for a brake sound collection system, the brake sound collection system comprises: a suspension, a hydraulic brake, a drive motor, a microphone, an environmental chamber and a control console, the hydraulic brake is arranged on the suspension, the suspension and the hydraulic brake are arranged in the environmental chamber, the torque output end of the drive motor is connected to the brake disc of the hydraulic brake through a connecting shaft, the brake caliper of the hydraulic brake is provided with a brake pad to be tested, and the control console is respectively connected to the environmental chamber, the hydraulic brake, the drive motor and the microphone;

[0006] The method is performed by the console in the brake sound collection system, and the method includes:

[0007] Controlling the environmental chamber to set a test environment, wherein the test environment includes environmental humidity and environmental temperature;

[0008] Under the test environment, the drive motor is controlled to output torque, and the brake caliper of the hydraulic brake is controlled to brake based on a test condition, wherein the test condition is used to simulate the condition of the vehicle when starting on a slope;

[0009] When the state of the brake disc meets the test condition, a braking sound collected by the microphone is obtained, where the braking sound is generated by friction between the brake pad to be tested and the brake disc.

[0010] On the other hand, an embodiment of the present application provides a braking sound collection device, the device comprising:

[0011] An environmental control module, used to control the environmental chamber to set a test environment, wherein the test environment includes environmental humidity and environmental temperature;

[0012] A working condition control module, used for controlling the drive motor to output torque and controlling the brake caliper of the hydraulic brake under the test environment based on the test working condition, wherein the test working condition is used to simulate the working condition of the vehicle when starting on a slope;

[0013] The acquisition module is used to acquire the braking sound collected by the microphone when the state of the brake disc meets the test conditions, and the braking sound is generated by the friction between the brake pad to be tested at the brake caliper and the brake disc.

[0014] On the other hand, an embodiment of the present application provides a braking sound collection system, the braking sound collection system comprising:

[0015] A suspension, a hydraulic brake, a drive motor, a microphone, an environmental chamber and a control console, wherein the hydraulic brake is arranged on the suspension, and the suspension and the hydraulic brake are arranged in the environmental chamber, the torque output end of the drive motor is connected to the brake disc of the hydraulic brake through a connecting shaft, the brake caliper of the hydraulic brake is provided with a brake pad to be tested, and the control console is respectively connected to the environmental chamber, the hydraulic brake, the drive motor and the microphone;

[0016] The control console is used to control the environmental chamber to set a test environment, wherein the test environment includes environmental humidity and environmental temperature;

[0017] The console is further used to control the drive motor to output torque and control the brake caliper of the hydraulic brake to brake under the test environment based on a test condition, wherein the test condition is used to simulate the condition of the vehicle starting on a slope;

[0018] The console is further used to obtain the braking sound collected by the microphone when the state of the brake disc meets the test condition, and the braking sound is generated by the friction between the brake pad to be tested and the brake disc.

[0019] In the related art, the braking sound is generated by manually controlling the vehicle to creep at a low speed, and then the braking sound is subjectively evaluated. This method is easily affected by the environment, resulting in deviations in the results.

[0020] In the embodiment of the present application, the console can adjust the ambient temperature and humidity of the environment in which the brake pad is located through the environmental chamber to prevent changes in ambient temperature and humidity from affecting the collection results. The console can also control the brake calipers of the drive motor and the hydraulic brake to simulate the working conditions when the vehicle starts on a slope, and collect the brake sound generated by the friction between the brake pad and the brake disc, which is beneficial to reduce the result deviation caused by human errors. In short, the technical solution provided in the embodiment of the present application can improve the accuracy of the brake sound collection results. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a structural schematic diagram of a brake sound collection system provided by an exemplary embodiment of the present application;

[0022] Figure 2 is a structural schematic diagram of a suspension angle module with a brake assembly provided by an exemplary embodiment of the present application;

[0023] Figure 3 is a flow chart of a brake sound collection method provided by an exemplary embodiment of the present application;

[0024] Figure 4 A flow chart showing a control process of controlling a drive motor to output torque;

[0025] Figure 5 A flow chart showing a control process of controlling the brake caliper braking of a hydraulic brake;

[0026] Figure 6 is a flow chart of a brake sound collection method provided by another exemplary embodiment of the present application;

[0027] Figure 7 It is a structural block diagram of a brake sound collection device provided in an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0029] First, some technical terms involved in this application are explained below.

[0030] Hydraulic brakes: brakes that use brake fluid to control the brake caliper. When the driver presses the brake pedal, the pressure of the brake fluid changes, causing the brake caliper to brake.

[0031] Brake caliper: A component installed in the brake system that can press the brake pads against the brake disc under the pressure of the brake fluid to achieve the braking effect.

[0032] Brake pad: A part that acts as a brake in a vehicle's braking system. The quality of the brake pad plays a decisive role in the braking effect.

[0033] Braking sound: also known as Groan sound, it is produced by the friction and vibration between the brake pads when the vehicle starts slowly or stops.

[0034] Brake fluid: A liquid with incompressible properties that, when pressurized in a sealed container, can transfer pressure to all parts of the liquid, achieving hydraulic braking.

[0035] The Groan sound (braking sound) when the vehicle starts has a great impact on the comfort of vehicle use. Currently, Groan sound detection is achieved through manual testing on the whole vehicle, that is, on flat and sloped roads, the driver controls the vehicle speed and brake hydraulic pressure by stepping on the brake pedal to keep the vehicle creeping forward or backward at an extremely low speed, thereby making a subjective evaluation of the Groan sound in this working condition.

[0036] However, the whole vehicle Groan sound detection is carried out outdoors and is greatly affected by the ambient temperature and humidity, which can easily lead to deviations in the brake sound collection results.

[0037] An embodiment of the present application provides a brake sound collection method, which simulates the working conditions of a vehicle when starting on a slope in a brake sound collection system, and controls the ambient temperature and ambient temperature through an environmental chamber to reduce the impact of the test environment on the brake pad, thereby improving the accuracy of the collection results.

[0038] See also Figure 1 , Figure 1 1 is a schematic diagram of a brake sound collection system provided by an exemplary embodiment of the present application. The brake sound collection system includes: a hydraulic brake 101 , a suspension 102 , an environmental chamber 103 , a drive motor 104 , a console 105 and a microphone 106 .

[0039] The hydraulic brake 101 is arranged on the suspension 102, and the suspension 102 and the hydraulic brake 101 are arranged in the environmental chamber 103. The torque output end of the driving motor 104 is connected to the brake disc of the hydraulic brake 101 through a connecting shaft, and the brake caliper of the hydraulic brake 101 is provided with a brake pad to be tested, and the console 105 is respectively connected to the environmental chamber 103, the hydraulic brake 101, the driving motor 104 and the microphone 106.

[0040] The braking principle of the hydraulic brake 101 is to increase the pressure of the brake fluid inside the pipeline (brake hydraulic pressure) and transmit the pressure to the brake caliper of the hydraulic brake 101, so that the brake pad on the brake caliper contacts the brake disc of the hydraulic brake 101, preventing the brake disc from rotating, thereby achieving the braking effect.

[0041] Optionally, the brake hydraulic pressure of the hydraulic brake 101 may be controlled by an additional hydraulic pressure module (not shown in the figure) to simulate the actual use of the hydraulic brake 101 on the vehicle.

[0042] The suspension 102 is used to support the hydraulic brake 101 so that the hydraulic brake 101 can be easily connected to other devices, so as to simulate the arrangement of the hydraulic brake 101 on the whole vehicle.

[0043] The environmental chamber 103 is used to control the environment of the brake pad to be tested, thereby reducing the impact of the environment on the test results.

[0044] The driving motor 104 is used to drive the brake disc of the hydraulic brake 101 to rotate. Since the driving motor 104 and the brake disc of the hydraulic brake 101 are connected via a connecting shaft, the speed of the brake disc is the same as the speed of the motor. A speed sensor for measuring the speed of the motor can be arranged on the connecting shaft. Optionally, the driving motor 104 can be a servo motor.

[0045] Since the pressure applied by the brake caliper of the hydraulic brake 101 to the brake disc is controlled by the brake hydraulic pressure, the braking torque of the hydraulic brake 101 is not the same as the motor torque output by the drive motor 104. When the motor torque is less than the braking torque, the brake disc decelerates.

[0046] The control console 105 is used to control the environmental chamber 103 to set a test environment, and the test environment includes environmental humidity and environmental temperature; it is also used to control the drive motor 104 to output torque and control the brake caliper braking of the hydraulic brake 101 based on the test conditions under the test environment, and the test conditions are used to simulate the conditions of the vehicle when starting on a slope; it is also used to obtain the braking sound collected by the microphone 106 when the state of the brake disc meets the test conditions. The braking sound is generated by the friction between the brake pad to be tested and the brake disc.

[0047] In order to improve the accuracy of the collection results, additional devices and tooling connections are required between the hydraulic brake 101 and the suspension 102 in the environmental chamber 103 so that the test conditions are consistent with the actual usage conditions on the vehicle.

[0048] See also Figure 2 , Figure 2 This is a schematic diagram of the structure of a suspension angle module with a brake assembly provided by an exemplary embodiment of the present application. The suspension angle module with a brake assembly is located in the environmental chamber and includes a suspension 201, a suspension spring 202, a shock absorber 203, a hydraulic brake 204 and other tooling. Among them, the suspension 201 is connected to the suspension spring 202, the suspension spring 202 is connected to the shock absorber 203, the shock absorber 203 is connected to the hydraulic brake 204, and other tooling is used to support the aforementioned connection structure.

[0049] The brake caliper 205 of the hydraulic brake contacts the surface of the brake disc 206 when the brake hydraulic pressure increases, and separates from the brake disc 206 when the brake hydraulic pressure decreases. The rotation center axis of the hydraulic brake 204 is coaxial with the torque output end of the drive motor.

[0050] The vehicle has four wheels, and each wheel may correspond to a hydraulic brake 204. Figure 2The connection of a single hydraulic brake 204 in the environmental chamber is shown. Optionally, four hydraulic brakes 204 may be provided in the brake sound collection system so that four brake pads can be tested synchronously as a group, or the number of hydraulic brakes 204 provided in the brake sound collection system may be adjusted based on actual test requirements.

[0051] See also Figure 3 , Figure 3 1 is a flow chart of a brake sound collection method provided by an exemplary embodiment of the present application. The brake sound collection method in the embodiment of the present application is executed by a console in a brake sound collection system. The method includes the following steps.

[0052] Step 301, controlling the environment chamber to set a test environment, the test environment including ambient humidity and ambient temperature.

[0053] In a possible implementation, the console reads the ambient temperature and ambient humidity corresponding to the test condition, and then instructs the environmental chamber to adjust the temperature to the ambient temperature and the humidity to the ambient humidity.

[0054] Optionally, before testing the brake pad, the control console may pre-regulate the environmental chamber to set the test environment, and then maintain the ambient temperature and humidity for a fixed period of time, so that the brake pad to be tested is fully affected by the ambient temperature and humidity, and then execute step 302. For example, the control console controls the environmental chamber to maintain the ambient temperature and humidity, so that the hydraulic brake with the brake pad to be tested in the environmental chamber is placed overnight.

[0055] Step 302 , under a test environment, based on a test condition, control the drive motor to output torque and control the brake caliper of the hydraulic brake to brake, wherein the test condition is used to simulate the condition of the vehicle starting on a slope.

[0056] In some embodiments, the drive motor outputs torque to simulate the tendency of the vehicle to slide down on a slope due to the influence of gravity. Since the tendency of the vehicle to slide down when starting on a slope is affected by many factors, such as the slope of the slope, the weight of the vehicle body, etc., there are various different test conditions. The motor torque output by the drive motor under different test conditions is different.

[0057] In some possible test conditions, the console first controls the brake caliper of the hydraulic brake to increase the braking torque, and controls the drive motor to output torque. The braking torque of the hydraulic brake is greater than the motor torque output by the drive motor, which can keep the brake disc of the hydraulic brake stable, that is, the brake disc speed is zero, so as to simulate the brake disc state when the vehicle is parked on a slope. After that, the console controls the hydraulic brake to slowly release the brake caliper, so that the drive motor starts to drive the brake disc to rotate, realizing the simulation of the vehicle from parking to starting.

[0058] Optionally, the console controls the brake caliper by controlling the brake hydraulic pressure, wherein the brake hydraulic pressure is positively correlated with the brake torque of the brake.

[0059] It should be noted that the working condition (test working condition) of the vehicle starting on a slope simulated in the embodiment of the present application does not refer to the uphill starting condition in which the engine provides power to overcome the gravity trend to climb up the slope, but refers to the getting-off starting condition controlled by the brake pedal. The console only needs to control the brake caliper of the hydraulic brake to obtain the braking sound when the vehicle starts, without adding additional devices or tooling to simulate the situation in which the engine provides power to start the vehicle.

[0060] In addition, the test condition simulates the condition when the vehicle starts on a slope, and can prolong the duration of the braking sound by reducing the starting speed, so as to accurately identify the braking sound. The braking sound when the vehicle stops is generated when the brake pedal is stepped on hard while the vehicle is driving, resulting in the braking sound lasting too short and difficult to control. Since the braking sound when the vehicle stops has the same cause as the braking sound when the vehicle starts, the embodiment of the present application obtains the braking sound by simulating the condition when the vehicle starts on a slope.

[0061] Step 303, when the state of the brake disc meets the test conditions, the braking sound collected by the microphone is obtained, and the braking sound is generated by the friction between the brake pad to be tested and the brake disc.

[0062] Among them, the test condition is used to simulate the condition of the vehicle when starting on a slope. Under this condition, the vehicle is in a state of slowly creeping forward, that is, it is in a critical state between a stationary state and a forward moving state. Correspondingly, the brake disc is in a vibrating state with a tendency to rotate.

[0063] In some embodiments, the state of the brake disc meets the test conditions, which means that the brake disc is in a critical state about to disengage from the rotation of the brake caliper, and the friction type between the brake pad and the brake disc in this critical state alternates between dynamic friction and static friction, causing the brake disc to vibrate. In the embodiment of the present application, the console controls the drive motor to output torque and controls the brake caliper of the hydraulic brake to brake, so that the brake disc to be tested enters the above critical state and generates a braking sound.

[0064] In some embodiments, a microphone is disposed around the brake to collect brake sound.

[0065] In the embodiment of the present application, the console can adjust the ambient temperature and humidity of the environment in which the brake pad is located through the environmental chamber to prevent changes in ambient temperature and humidity from affecting the collection results. The console can also control the brake calipers of the drive motor and the hydraulic brake to simulate the working conditions when the vehicle starts on a slope, and collect the brake sound generated by the friction between the brake pad and the brake disc, which is beneficial to reduce the result deviation caused by human errors. In short, the technical solution provided in the embodiment of the present application can improve the accuracy of the brake sound collection results.

[0066] In some embodiments, vehicle parameters and ramp angles are different under different test conditions, wherein the vehicle parameters and ramp angles have an impact on the braking torque of the hydraulic brake.

[0067] See also Figure 4 , Figure 4 The flowchart of the control process of controlling the drive motor to output torque is shown. The process includes the following steps.

[0068] 3021A, based on the vehicle parameters and the ramp angle under the test condition, determine the parking braking torque corresponding to the ramp angle, and the parking braking torque is the minimum braking torque required for parking on the ramp.

[0069] Optionally, vehicle parameters may include vehicle weight, vehicle rolling radius, etc., wherein the vehicle weight may be determined based on the vehicle mass and the gravity coefficient.

[0070] Exemplarily, the parking brake torque is determined as shown in Formula 1:

[0071] Formula 1: T1 = mg*sin(a)*R / 2

[0072] Among them, T1 is the parking braking torque (in Nm), m is the vehicle mass (in kg), g is the gravity coefficient, mg is the vehicle weight, a is the ramp angle, and R is the rolling radius of the vehicle (in m).

[0073] In some embodiments, the vehicle has a tendency to slide down due to the influence of gravity, and the parking braking torque of the hydraulic brake is the minimum braking torque required to overcome the sliding tendency and ensure that the vehicle stops steadily.

[0074] 3021B, determining the motor torque of the drive motor under the test condition based on the parking brake torque.

[0075] Since the parking braking torque is the minimum braking torque required for parking on a slope, using a torque of the same magnitude can simulate the downward sliding tendency of the vehicle under the influence of gravity under the same working condition, so that the brake disc has a rotation tendency similar to that when the vehicle slides down.

[0076] In some embodiments, the controller sets the motor torque to a torque of the same magnitude as the parking brake torque, outputs the motor torque through the driving motor, and acts on the brake disc, so that the brake disc has a rotation tendency when the vehicle slides down.

[0077] 3021C, based on motor torque control, drives the motor to output torque.

[0078] In a possible implementation, the control console adjusts the current or voltage of the drive motor so that the drive motor outputs the motor torque.

[0079] In another possible implementation, the control console sends a torque setting instruction to the drive motor to set the motor torque.

[0080] In some embodiments, the console controls the brake caliper by controlling the brake hydraulic pressure.

[0081] See also Figure 5 , Figure 5 The flowchart of the control process of the brake caliper of the hydraulic brake is shown. The process includes the following steps.

[0082] 3022A, determining the brake hydraulic pressure based on the parking brake torque and the brake parameters of the hydraulic brake.

[0083] Optionally, the brake fluid pressure is positively correlated with the braking torque generated by the hydraulic brake. When the brake fluid pressure increases, the braking torque increases, and when the brake fluid pressure decreases, the braking torque decreases.

[0084] In order to simulate the condition of the vehicle changing from parking to starting on a slope, the brake hydraulic pressure needs to be greater than or equal to the hydraulic pressure required to generate the parking brake torque. Among them, when the braking torque of the hydraulic brake is greater than the parking brake torque, the vehicle stays stably on the slope. When the vehicle changes from the parking state to the starting state on the slope, the braking torque generated by the hydraulic brake gradually decreases, and the brake hydraulic pressure gradually decreases. When the braking torque of the hydraulic brake is equal to the parking brake torque, the vehicle has a tendency to start downhill.

[0085] From the above reasoning, it can be seen that under the test conditions, when the brake hydraulic pressure corresponding to the braking torque generated by the hydraulic brake is equal to the brake hydraulic pressure corresponding to the parking braking torque, the brake disc has a tendency to rotate.

[0086] Optionally, the brake parameters of the hydraulic brake may include the front brake caliper cylinder diameter, the front wheel braking effective radius, the front brake friction coefficient, the rear brake caliper cylinder diameter, the rear wheel braking effective radius, and the rear brake friction coefficient.

[0087] Exemplarily, the braking torque generated by the hydraulic brake is determined as shown in Formula 2:

[0088] Formula 2: T2 = P*(D1 / 2) 2 *π*r1*u1*4+P*(D2 / 2) 2 *π*r2*u2*4

[0089] Wherein, T2 is the braking torque generated by the hydraulic brake (in Nm), P is the brake fluid pressure (in Pa), D1 is the front brake caliper cylinder diameter (in m), r1 is the front wheel brake effective radius (in m), u1 is the front brake friction coefficient, D2 is the rear brake caliper cylinder diameter (in m), r2 is the rear wheel brake effective radius (in m), and u2 is the rear brake friction coefficient. When determining the parking brake torque T1, the console uses the rotation tendency of the brake disc when T1=T2 (used to simulate the downhill starting tendency of the vehicle) to bring the parking brake torque into Formula 2 to determine the brake fluid pressure P.

[0090] 3022B, brake caliper braking based on brake hydraulic pressure control.

[0091] In some possible implementations, the console first controls the pressure of the dynamic fluid to exceed the brake fluid pressure, so that the brake disc can remain stationary when the drive motor outputs the motor torque. After the brake fluid pressure is continuously pressurized for a period of time, the console controls the brake fluid pressure to slowly decrease until the state of the brake disc meets the test conditions.

[0092] It should be noted that due to the error in the friction coefficient, the console cannot directly control the brake caliper braking by setting the brake hydraulic pressure to make the state of the brake disc meet the test conditions. Instead, the brake fluid pressure must first exceed the brake hydraulic pressure, and then the state of the brake disc must be determined during the process of the hydraulic pressure dropping.

[0093] In an exemplary example, the controller sets the brake hydraulic pressure, and then applies hydraulic pressure for about 20 seconds so that the pressure of the brake fluid exceeds the brake hydraulic pressure. After 20 seconds, the hydraulic pressure is released to determine whether the state of the brake disc meets the test conditions. If it meets the test conditions, the brake sound collected by the microphone is obtained.

[0094] In an embodiment of the present application, the console determines the motor torque based on the parking brake torque, so that the drive motor can be used to simulate the downward sliding tendency of the vehicle under the influence of gravity in a slope parking condition, and the brake hydraulic pressure is determined according to the parking brake torque to adjust the brake caliper of the hydraulic brake so that the state of the brake disc meets the test condition, which is beneficial to improving the efficiency of the console in controlling the brake disc to enter a state that meets the test condition, so that the microphone can quickly collect the braking sound.

[0095] In some embodiments, in order to extend the duration of the braking sound so as to accurately identify the braking sound, the console can control the motor speed. The braking sound collected by the microphone can be used to test the brake pads.

[0096] See also Figure 6 , Figure 6 FIG. 1 is a flow chart of a brake sound collection method provided by another exemplary embodiment of the present application. The method comprises the following steps.

[0097] Step 601, controlling the environment chamber to set a test environment, the test environment including ambient humidity and ambient temperature.

[0098] Step 602 , under a test environment, based on a test condition, control the drive motor to output torque and control the brake caliper of the hydraulic brake to brake, wherein the test condition is used to simulate the condition of the vehicle starting on a slope.

[0099] Among them, the specific description of step 601 and step 602 can refer to step 301 and step 302, and will not be repeated in the embodiment of the present application.

[0100] Step 603, obtaining the motor speed of the driving motor.

[0101] Optionally, a speed sensor is provided on the connecting shaft between the hydraulic brake and the driving motor to measure the motor speed, which is the same as the brake disc speed. The console receives the motor speed collected by the speed sensor.

[0102] Step 604 , determining whether the state of the brake disc meets the test condition based on the motor speed.

[0103] In some embodiments, when the state of the brake disc meets the test condition, the motor speed is approximately zero.

[0104] Optionally, the console determines that the state of the brake disc meets the test conditions when the motor speed is less than the upper speed limit under the test conditions.

[0105] It should be noted that the upper limit of the motor speed is consistent with the speed range of the vehicle when the vehicle is creeping forward at a low speed. For example, the motor speed is ≤3r / min.

[0106] In an illustrative example, the upper speed limit is 3 r / min. When the motor speed is less than 3 r / min, the control console determines that the state of the brake disc meets the test conditions and can collect the braking sound.

[0107] Optionally, when the motor speed is greater than an upper speed limit under the test condition, the console determines that the state of the brake disc does not meet the test condition.

[0108] In an illustrative example, the upper speed limit is 3r / min. When the motor speed is greater than 3r / min, the console determines that the state of the brake disc does not meet the test conditions and needs to adjust the state of the brake disc in order to collect the brake sound.

[0109] The following is an explanation of how the console adjusts the brake disc status.

[0110] Optionally, when the motor speed is greater than the upper speed limit under the test condition, the control console increases the brake fluid pressure of the brake based on the boost step length, wherein the boost step length is used to characterize the boost rate, that is, the increase in the brake fluid pressure of the hydraulic brake per second.

[0111] Since the brake hydraulic pressure is positively correlated with the brake torque, when the brake hydraulic pressure increases, the brake torque increases, so the brake disc speed gradually decreases, and the motor speed of the drive motor coaxial with the brake disc gradually decreases.

[0112] Exemplarily, the control console increases the brake fluid pressure by 0.5 bar in the first second when the motor speed is greater than the upper speed limit, and increases it by another 0.5 bar in the second second... until the motor speed is less than the upper speed limit under the test condition.

[0113] Optionally, when the motor speed is less than the upper speed limit under the test condition, the console maintains the brake fluid pressure according to a set time to prevent the motor speed from exceeding the upper speed limit so that the microphone can collect the brake sound. For example, when the motor speed is less than the upper speed limit under the test condition, the console controls the brake fluid to be maintained for 10 seconds.

[0114] Step 605, when the state of the brake disc meets the test conditions, obtain the braking sound collected by the microphone, where the braking sound is generated by the friction between the brake pad to be tested and the brake disc.

[0115] Among them, the specific description of step 605 can refer to step 303, and will not be repeated in the embodiment of the present application.

[0116] Step 606 , determining a brake pad test result of the brake pad to be tested based on the brake sounds under different test conditions and test environments.

[0117] Optionally, the console can repeat the test a fixed number of times, such as 3 times, under the same test conditions and the same test environment to improve the accuracy of the brake pad test results.

[0118] Optionally, the console can test the brake pads under different test conditions in the same test environment, or test the brake pads under the same test conditions in different test environments.

[0119] Regarding the determination of the brake pad test result, optionally, the console can determine that the brake pad has passed the test when the sound pressure of the braking sound is less than the sound pressure threshold, and determine that the brake pad has failed the test when the sound pressure of the braking sound is greater than the sound pressure threshold. Optionally, the brake pad test result can also be determined in combination with the subjective evaluation results of technical experts. Optionally, the brake pad test result can also be determined based on the output results of the machine learning model.

[0120] In the embodiment of the present application, the control console determines whether the brake disc meets the test conditions according to the motor speed, so as to obtain the brake sound collected by the microphone when the conditions are met. Since the brake sound generated by the same brake pad may be different when the motor speed is different, the control console determines the time to collect the brake sound according to the motor speed, which is conducive to improving the accuracy of the brake sound collection results.

[0121] Among them, the console provides a unified standard for the timing of collecting brake sounds, that is, when the motor speed is less than the upper speed limit under the test conditions, it is determined that the state of the brake disc meets the test conditions, ensuring that the motor speed meets the state of the vehicle creeping forward at a low speed and reducing the impact of the motor speed on the brake sound.

[0122] When the above standards are not met, the console can increase the brake hydraulic pressure to make the motor speed less than the upper speed limit under the test conditions. This is beneficial for the console to maintain a stable motor speed, extend the time for the microphone to collect brake sounds, and improve the accuracy of the brake sound collection results.

[0123] Among them, by collecting the braking sounds under different test conditions and test environments, the accuracy of the brake pad test results of the brake pad to be tested can be improved.

[0124] In some embodiments, the test environment in the environmental chamber may be affected by the external environment. For example, when the external environment temperature rises, the ambient temperature in the environmental chamber will also rise. In order to maintain a stable test environment, the console needs to adjust the test environment in the environmental chamber in real time.

[0125] Optionally, during the test process, the console first obtains the real-time environmental parameters in the environmental chamber, and then controls the environmental chamber to adjust the test environment based on the real-time environmental parameters to keep the test environment stable.

[0126] Optionally, the real-time environmental parameters may include the ambient temperature collected by a temperature sensor in the environmental chamber and the ambient humidity collected by a humidity sensor.

[0127] In a possible implementation, when the ambient temperature is higher than the temperature set by the console, the console controls the air conditioning system in the environmental chamber to reduce the ambient temperature. When the ambient humidity is higher than the humidity set by the console, the console controls the air conditioning system in the environmental chamber to reduce the ambient humidity.

[0128] In another possible implementation, when the ambient temperature is lower than the temperature set by the console, the console controls the air conditioning system in the environmental chamber to increase the ambient temperature. When the ambient humidity is lower than the humidity set by the console, the console controls the air conditioning system in the environmental chamber to increase the ambient humidity.

[0129] In the embodiment of the present application, the console can adjust the test environment in real time according to the real-time environmental parameters, which is beneficial to stabilize the test environment during the test process and improve the accuracy of the brake pad test results.

[0130] In some embodiments, the console may determine the brake pad test result of the brake pad to be tested in the following manner.

[0131] Method 1: Generate a brake sound pressure curve of the brake pad to be tested. This method includes the following two steps.

[0132] Step 1, based on the test condition parameters of different test conditions, the environmental parameters of the test environment and the sound pressure parameters of the brake sound, generate a brake sound pressure curve of the brake pad to be tested, the brake sound pressure curve is used to characterize the corresponding relationship between the test condition, the test environment and the sound pressure parameters.

[0133] Optionally, the environmental parameters of the test environment may include ambient temperature and ambient humidity, the test condition parameters may include vehicle parameters, ramp angle and brake parameters, and the sound pressure parameters of the braking sound may include sound pressure, sound pressure level, etc.

[0134] In some embodiments, the brake sound pressure curve can represent the changes in the sound pressure parameters of the brake sound under different test conditions and under different test environments.

[0135] Step 2: determining a brake pad test result of the brake pad to be tested based on the brake sound pressure curve.

[0136] Different brake pads correspond to different brake sound pressure curves.

[0137] Optionally, the console can also display the brake sound pressure curves of different brake pads, and then determine the brake pad test results based on the technical expert's evaluation of the brake sound pressure curves.

[0138] Optionally, the console can also compare the brake sound pressure curves of different brake pads and then determine the brake pad test results.

[0139] Method 2: The brake sound evaluation model outputs the brake pad test results. This method includes the following two steps.

[0140] Step 1: splicing the test condition parameters of different test conditions, the environmental parameters of the test environment and the sound pressure parameters of the braking sound to obtain the brake pad data of the brake pad to be tested.

[0141] Optionally, the environmental parameters of the test environment may include ambient temperature and ambient humidity, the test condition parameters may include vehicle parameters, ramp angle and brake parameters, and the sound pressure parameters of the braking sound may include sound pressure, sound pressure level, etc.

[0142] In an illustrative example, the ambient temperature in the environmental parameters is 20°C, the ramp angle in the test condition parameters is 2°, and the brake sound pressure is 0.75dB, then the brake pad data of the brake pad to be tested is 20°C|2°|0.75dB.

[0143] Step 2: input the brake pad data into a brake pad evaluation model to obtain a brake pad test result output by a brake sound evaluation model. The brake pad evaluation model is trained based on sample brake pad data of a sample brake pad and a sample brake pad test result of a sample brake pad.

[0144] Optionally, the console can vectorize the spliced ​​brake pad data, or first vectorize each parameter of the test condition parameter, the environmental parameter of the test environment, and the sound pressure parameter of the brake sound, and then obtain a feature vector representing the brake pad data through vector splicing. The console then inputs the vectorized brake pad data into the brake pad evaluation model.

[0145] Optionally, the sample brake pad data of the sample brake pad and the sample brake pad test results of the sample brake pad may be determined based on a subjective evaluation of the vehicle driver.

[0146] Optionally, the brake pad evaluation model can be a classification model, and the classification result is the brake pad test result output by the brake sound evaluation model. For example, when the brake sound evaluation model outputs 1, it indicates that the brake pad has passed the test; when the brake sound evaluation model outputs 0, it indicates that the brake pad has failed the test.

[0147] In the embodiment of the present application, the console can determine the brake pad test result of the brake pad to be tested by generating a brake sound pressure curve, thereby improving the efficiency of determining the brake pad test result.

[0148] The console can also determine the brake pad test results of the brake pad to be tested according to the output results of the brake pad evaluation model, reduce the impact of errors caused by human evaluation, and improve the accuracy of the brake pad test results.

[0149] See also Figure 7 , Figure 7 This is a structural block diagram of a braking sound collection device provided by an exemplary embodiment of the present application. The device includes the following modules.

[0150] The environment control module 701 is used to control the environment chamber to set the test environment, and the test environment includes the environment humidity and the environment temperature;

[0151] The working condition control module 702 is used to control the drive motor to output torque and control the brake caliper of the hydraulic brake under the test environment based on the test working condition, wherein the test working condition is used to simulate the working condition of the vehicle when starting on a slope;

[0152] The acquisition module 703 is used to acquire the braking sound collected by the microphone when the state of the brake disc meets the test conditions, wherein the braking sound is generated by the friction between the brake pad to be tested at the brake caliper and the brake disc.

[0153] Optionally, the operating condition control module 702 is further used to:

[0154] Based on the vehicle parameters and the ramp angle under the test condition, determining a parking braking torque corresponding to the ramp angle, the parking braking torque being a minimum braking torque required for parking on a ramp;

[0155] determining a motor torque of the drive motor under the test condition based on the parking brake torque;

[0156] Controlling the drive motor to output torque based on the motor torque;

[0157] The operating condition control module 702 is further used for:

[0158] determining a brake hydraulic pressure based on the parking brake torque and a brake parameter of the hydraulic brake;

[0159] The brake caliper is controlled to brake based on the brake fluid pressure.

[0160] Optionally, the device further includes a state determination module, configured to:

[0161] Obtaining the motor speed of the driving motor;

[0162] It is determined whether the state of the brake disc meets the test condition based on the motor speed.

[0163] Optionally, the state determination module is further used to:

[0164] When the motor speed is less than the upper speed limit under the test condition, determining that the state of the brake disc meets the test condition;

[0165] When the motor speed is greater than the upper speed limit under the test condition, it is determined that the state of the brake disc does not conform to the test condition.

[0166] Optionally, the device further comprises a hydraulic adjustment module, for:

[0167] When the motor speed is greater than the upper speed limit under the test condition, the brake hydraulic pressure of the hydraulic brake is increased based on the boost step size.

[0168] Optionally, the device further comprises an environment adjustment module, which is used to:

[0169] During the test, real-time environmental parameters in the environmental chamber are obtained;

[0170] The environmental chamber is controlled to adjust the test environment based on the real-time environmental parameters to keep the test environment stable.

[0171] Optionally, the device further comprises a result determination module, configured to:

[0172] Based on the braking sounds under different test conditions and test environments, a brake pad test result of the brake pad to be tested is determined.

[0173] Optionally, the result determination module is further used to:

[0174] Based on the test condition parameters of different test conditions, the environmental parameters of the test environment and the sound pressure parameters of the brake sound, a brake sound pressure curve of the brake pad to be tested is generated, wherein the brake sound pressure curve is used to characterize the corresponding relationship between the test condition, the test environment and the sound pressure parameters; based on the brake sound pressure curve, the brake pad test result of the brake pad to be tested is determined;

[0175] The result determination module is further used for:

[0176] The test condition parameters of different test conditions, the environmental parameters of the test environment and the sound pressure parameters of the brake sound are spliced ​​to obtain the brake pad data of the brake pad to be tested; the brake pad data is input into a brake pad evaluation model to obtain the brake pad test result output by the brake sound evaluation model, and the brake pad evaluation model is trained based on sample brake pad data of a sample brake pad and sample brake pad test results of the sample brake pad.

[0177] In the embodiment of the present application, the console can adjust the ambient temperature and humidity of the environment in which the brake pad is located through the environmental chamber to prevent changes in ambient temperature and humidity from affecting the collection results. The console can also control the brake calipers of the drive motor and the hydraulic brake to simulate the working conditions when the vehicle starts on a slope, and collect the brake sound generated by the friction between the brake pad and the brake disc, which is beneficial to reduce the result deviation caused by human errors. In short, the technical solution provided in the embodiment of the present application can improve the accuracy of the brake sound collection results.

[0178] A person skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware, or may be accomplished by a program to guide the relevant hardware. The program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a disk or an optical disk, etc.

[0179] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A braking sound collection method, characterized in that: The method is used for a brake sound collection system, which includes: a suspension, a hydraulic brake, a drive motor, a microphone, an environmental chamber and a control console, wherein the hydraulic brake is arranged on the suspension, and the suspension and the hydraulic brake are arranged in the environmental chamber, the torque output end of the drive motor is connected to the brake disc of the hydraulic brake through a connecting shaft, the brake caliper of the hydraulic brake is provided with a brake pad to be tested, and the control console is respectively connected to the environmental chamber, the hydraulic brake, the drive motor and the microphone; The method is performed by the console in the brake sound collection system, and the method includes: Controlling the environmental chamber to set a test environment, wherein the test environment includes environmental humidity and environmental temperature; Under the test environment, the drive motor is controlled to output torque, and the brake caliper of the hydraulic brake is controlled to brake based on a test condition, wherein the test condition is used to simulate the condition of the vehicle when starting on a slope; When the state of the brake disc meets the test condition, a braking sound collected by the microphone is obtained, where the braking sound is generated by friction between the brake pad to be tested and the brake disc.

2. The method according to claim 1, characterized in that The step of controlling the drive motor to output torque based on the test condition includes: Based on the vehicle parameters and the ramp angle under the test condition, determining a parking braking torque corresponding to the ramp angle, the parking braking torque being a minimum braking torque required for parking on a ramp; determining a motor torque of the drive motor under the test condition based on the parking brake torque; Controlling the drive motor to output torque based on the motor torque; The step of controlling the brake caliper of the hydraulic brake comprises: determining a brake hydraulic pressure based on the parking brake torque and a brake parameter of the hydraulic brake; The brake caliper is controlled to brake based on the brake fluid pressure.

3. The method according to claim 1, characterized in that When the state of the brake disc meets the test condition, before obtaining the brake sound collected by the microphone, the method includes: Obtaining the motor speed of the driving motor; It is determined whether the state of the brake disc meets the test condition based on the motor speed.

4. The method according to claim 3, characterized in that The determining, based on the motor speed, whether the state of the brake disc meets the test condition comprises: When the motor speed is less than the upper speed limit under the test condition, determining that the state of the brake disc meets the test condition; When the motor speed is greater than the upper speed limit under the test condition, it is determined that the state of the brake disc does not conform to the test condition.

5. The method according to claim 4, characterized in that The method further comprises: When the motor speed is greater than the upper speed limit under the test condition, the brake hydraulic pressure of the hydraulic brake is increased based on the boost step size.

6. The method according to claim 1, characterized in that The method further comprises: During the test, real-time environmental parameters in the environmental chamber are obtained; The environmental chamber is controlled to adjust the test environment based on the real-time environmental parameters to keep the test environment stable.

7. The method according to claim 1, characterized in that The method further comprises: Based on the braking sounds under different test conditions and test environments, a brake pad test result of the brake pad to be tested is determined.

8. The method according to claim 7, characterized in that The step of determining the brake pad test result of the brake pad to be tested based on the brake sounds under different test conditions and test environments includes: Based on the test condition parameters of different test conditions, the environmental parameters of the test environment and the sound pressure parameters of the brake sound, a brake sound pressure curve of the brake pad to be tested is generated, wherein the brake sound pressure curve is used to characterize the corresponding relationship between the test condition, the test environment and the sound pressure parameters; based on the brake sound pressure curve, the brake pad test result of the brake pad to be tested is determined; or, The test condition parameters of different test conditions, the environmental parameters of the test environment and the sound pressure parameters of the brake sound are spliced ​​to obtain the brake pad data of the brake pad to be tested; the brake pad data is input into a brake pad evaluation model to obtain the brake pad test result output by the brake sound evaluation model, and the brake pad evaluation model is trained based on sample brake pad data of a sample brake pad and sample brake pad test results of the sample brake pad.

9. A braking sound collection device, characterized in that: The device comprises: An environmental control module, used to control the environmental chamber to set a test environment, wherein the test environment includes environmental humidity and environmental temperature; A working condition control module, used for controlling the drive motor to output torque and controlling the brake caliper of the hydraulic brake under the test environment based on the test working condition, wherein the test working condition is used to simulate the working condition of the vehicle when starting on a slope; The acquisition module is used to acquire the braking sound collected by the microphone when the state of the brake disc meets the test conditions, and the braking sound is generated by the friction between the brake pad to be tested at the brake caliper and the brake disc.

10. A braking sound collection system, characterized in that: The braking sound collection system comprises: A suspension, a hydraulic brake, a drive motor, a microphone, an environmental chamber and a control console, wherein the hydraulic brake is arranged on the suspension, and the suspension and the hydraulic brake are arranged in the environmental chamber, the torque output end of the drive motor is connected to the brake disc of the hydraulic brake through a connecting shaft, the brake caliper of the hydraulic brake is provided with a brake pad to be tested, and the control console is respectively connected to the environmental chamber, the hydraulic brake, the drive motor and the microphone; The control console is used to control the environmental chamber to set a test environment, wherein the test environment includes environmental humidity and environmental temperature; The console is further used to control the drive motor to output torque and control the brake caliper of the hydraulic brake to brake under the test environment based on a test condition, wherein the test condition is used to simulate the condition of the vehicle starting on a slope; The console is further used to obtain the braking sound collected by the microphone when the state of the brake disc meets the test condition, and the braking sound is generated by the friction between the brake pad to be tested and the brake disc.

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