Braking control method and device

Abstract

This application belongs to the field of braking and discloses a braking control method and device. The method includes: when a collision risk between the vehicle and the preceding vehicle is detected, activating the emergency braking function; after the emergency braking function is activated, sending a first activation signal to the first solenoid valve, increasing the pressure of the wheel cylinder through the first brake line to achieve braking control, and obtaining the first vehicle speed of the vehicle; if the first vehicle speed is equal to the second vehicle speed, obtaining the operating voltage of the first solenoid valve; the second vehicle speed is the vehicle speed when the electronic stability system determines that there is a collision risk between the vehicle and the preceding vehicle; if the operating voltage does not reach a preset operating voltage threshold, sending a second activation signal to the second solenoid valve, increasing the pressure of the wheel cylinder through the second brake line to achieve braking control. Using this application, when the vehicle's original solenoid valve fails, the backup solenoid valve can be activated to complete vehicle braking.

Description

Technical Field

[0001] The present application relates to the technical field of automatic emergency braking, and in particular to a braking control method and device. Background Art

[0002] When the vehicle is driving in non-adaptive cruise control, when the vehicle is driving on a road with heavy traffic or when the vehicle ahead is driving abnormally or suddenly stops, there is a high risk of collision between the vehicle and the vehicle ahead.

[0003] In existing technology, when a vehicle faces a high risk of collision with the vehicle ahead, the vehicle's automatic emergency braking function alerts the driver. If the driver fails to respond, or if the risk of collision persists despite a response, the electronic stability system automatically increases pressure and applies automatic braking measures to mitigate or avoid the collision. However, the solenoid valve device in the electronic stability system may age, causing functional malfunctions in the automatic emergency braking function, preventing the electronic stability system from braking properly and potentially leading to a collision with the vehicle ahead. Summary of the Invention

[0004] Based on this, it is necessary to provide a braking control method and device to address the above technical issues.

[0005] In a first aspect, a brake control method is provided. The method is applied to an electronic stability system of a vehicle. A first solenoid valve is provided on a first brake line of a wheel cylinder of the vehicle, and a second solenoid valve is provided on a second brake line. The method includes:

[0006] When a collision risk is detected between the vehicle and the vehicle ahead, the emergency braking function is activated;

[0007] After the emergency braking function is activated, a first activation signal is sent to the first solenoid valve, the wheel cylinder is pressurized via the first brake line to implement braking control, and a first vehicle speed of the vehicle is obtained;

[0008] If the first vehicle speed is equal to a second vehicle speed, obtaining the operating voltage of the first solenoid valve; the second vehicle speed is the vehicle speed of the vehicle when the electronic stability system determines that there is a risk of collision between the vehicle and the preceding vehicle;

[0009] If the operating voltage does not reach the preset operating voltage threshold, a second activation signal is sent to the second solenoid valve to increase the pressure of the brake wheel cylinder through the second brake line to achieve braking control.

[0010] As an optional implementation, the method further includes:

[0011] Obtaining a second vehicle speed of the host vehicle, a first acceleration of the host vehicle, a relative distance between the host vehicle and the preceding vehicle, a third vehicle speed of the preceding vehicle, and a second acceleration of the preceding vehicle;

[0012] determining a time to collision TTC between the host vehicle and the preceding vehicle based on the second vehicle speed, the third vehicle speed, the first acceleration, the second acceleration, and the relative distance;

[0013] Determining a target TTC threshold value corresponding to the speed difference between the first vehicle speed and the third vehicle speed in a pre-stored correspondence between the speed difference between the host vehicle and the preceding vehicle and the TTC threshold value;

[0014] If the TTC is less than or equal to the target TTC threshold, it is determined that there is a risk of collision between the vehicle and the preceding vehicle, and the emergency braking function is activated; otherwise, it is determined that there is no risk of collision between the vehicle and the preceding vehicle, and the vehicle continues to be controlled to travel at the first vehicle speed.

[0015] As an optional implementation manner, the formula for determining the collision time TTC between the host vehicle and the preceding vehicle based on the first vehicle speed, the third vehicle speed, the first acceleration, the second acceleration, and the relative distance is:

[0016]

[0017] Among them, TTC represents the collision time between the vehicle and the preceding vehicle, △s represents the relative distance between the vehicle and the preceding vehicle, △v represents the speed difference between the second speed and the third speed, and △a represents the acceleration difference between the first acceleration and the second acceleration.

[0018] As an optional implementation manner, after the emergency braking function is activated, the method further includes:

[0019] When the preceding vehicle brakes suddenly or the preceding vehicle's speed is zero, the target safe speed of the own vehicle is determined to be zero;

[0020] When the preceding vehicle is in a constant speed or accelerating state, the current speed of the preceding vehicle is used as the target safe speed, and the speed of the host vehicle is reduced to the target safe speed.

[0021] As an optional implementation manner, if the first vehicle speed is less than the second vehicle speed and greater than the target safe vehicle speed, an alarm message indicating that the first brake line is blocked is output.

[0022] As an optional implementation, if the operating voltage reaches a preset operating voltage threshold, an alarm message of the hydraulic pump of the vehicle is output.

[0023] In a second aspect, a brake control device is provided. The device is applied to an electronic stability system of a vehicle. A first solenoid valve is provided on a first brake line of a wheel cylinder of the vehicle, and a second solenoid valve is provided on a second brake line. The device includes:

[0024] The activation module is used to activate the emergency braking function when a collision risk between the vehicle and the vehicle in front is detected;

[0025] a first sending module, configured to send a first activation signal to the first solenoid valve after the emergency braking function is activated, to pressurize the wheel cylinder via the first brake line to achieve braking control, and to obtain a first vehicle speed of the vehicle;

[0026] a first acquisition module, configured to acquire an operating voltage of the first solenoid valve if the first vehicle speed is equal to a second vehicle speed; the second vehicle speed being the vehicle speed of the vehicle when the electronic stability system determines that there is a risk of collision between the vehicle and the preceding vehicle;

[0027] The second sending module is used to send a second activation signal to the second solenoid valve if the working voltage does not reach a preset working voltage threshold, so as to increase the pressure of the brake wheel cylinder through the second brake line to achieve braking control.

[0028] As an optional implementation, the device further includes:

[0029] a second acquisition module, configured to acquire a second vehicle speed of the host vehicle, a first acceleration of the host vehicle, a relative distance between the host vehicle and the preceding vehicle, a third vehicle speed of the preceding vehicle, and a second acceleration of the preceding vehicle;

[0030] a first determining module, configured to determine a time to collision TTC between the host vehicle and the preceding vehicle based on the second vehicle speed, the third vehicle speed, the first acceleration, the second acceleration, and the relative distance;

[0031] a second determining module, configured to determine a target TTC threshold value corresponding to the speed difference between the first vehicle speed and the third vehicle speed from a pre-stored correspondence between the speed difference between the host vehicle and the preceding vehicle and the TTC threshold value;

[0032] a determination module configured to determine that there is a risk of collision between the vehicle and the preceding vehicle if the TTC is less than or equal to the target TTC threshold and activate an emergency braking function; otherwise, determine that there is no risk of collision between the vehicle and the preceding vehicle and continue to control the vehicle to travel at the first vehicle speed.

[0033] As an optional implementation manner, the first sending module is further configured to:

[0034] When the preceding vehicle brakes suddenly or the preceding vehicle's speed is zero, the target safe speed of the own vehicle is determined to be zero;

[0035] When the preceding vehicle is in a constant speed or accelerating state, the current speed of the preceding vehicle is used as the target safe speed, and the speed of the host vehicle is reduced to the target safe speed.

[0036] As an optional implementation manner, if the first vehicle speed is less than the second vehicle speed and greater than the target safe vehicle speed, an alarm message indicating that the first brake line is blocked is output.

[0037] In a third aspect, a braking control system is provided, which includes: the braking control method as described in the first aspect and the braking control device as described in the second aspect.

[0038] In a fourth aspect, a computer device is provided, comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the computer program, the method steps described in the first aspect are implemented.

[0039] In a fifth aspect, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the method steps described in the first aspect are implemented.

[0040] The present application provides a braking control method and device. The technical solution provided by the embodiments of the present application brings at least the following beneficial effects: when the vehicle is driving and it is detected that there is a risk of collision between the vehicle and the vehicle in front, the automatic emergency braking function of the vehicle is turned on. Activate the first solenoid valve to perform boost braking on the brake wheel cylinder. Then obtain the speed of the vehicle. If the speed is equal to the speed when there is a risk of collision between the vehicle and the vehicle in front, then it is necessary to obtain the working voltage of the first solenoid valve to determine whether the first solenoid valve is faulty. If it is a fault of the first solenoid valve, then activate the backup solenoid valve to ensure the braking control of the vehicle. In this way, it is possible to avoid the functional obstruction of the automatic emergency braking function caused by the aging problem of the original solenoid valve in the vehicle, which makes it impossible for the electronic stability system to brake normally, resulting in a collision between the vehicle and the vehicle in front.

[0041] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 A schematic diagram of the structure of an electronic stability system provided in an embodiment of the present application;

[0044] Figure 2 A flowchart of a braking control method provided in an embodiment of the present application;

[0045] Figure 3 A schematic structural diagram of a brake control device provided in an embodiment of the present application;

[0046] Figure 4 A schematic diagram of the structure of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0048] The braking control method provided in the embodiment of the present application can be applied to an electronic stability system. Figure 1 As shown, the electronic stability system includes a main controller module 101, a first brake line 102, a second brake line 103, a first solenoid valve 104, a second solenoid valve 105, and a wheel brake cylinder 106. The first solenoid valve 104 is provided on the first brake line 102 of the wheel brake cylinder 106, and the second solenoid valve 105 is provided on the second brake line 103.

[0049] The main controller module 101 is connected to a first solenoid valve 104 and a second solenoid valve 105, respectively, and is configured to activate the emergency braking function when a collision risk between the vehicle and the preceding vehicle is detected. After the emergency braking function is activated, the main controller module 101 sends a first activation signal to the first solenoid valve 104 on the first brake line 102, which increases the pressure in the wheel brake cylinder 106 via the first brake line 102 to achieve braking control and obtain a first vehicle speed. If the first vehicle speed is equal to the second vehicle speed, the operating voltage of the first solenoid valve 104 is obtained. The second vehicle speed is the vehicle speed at which the electronic stability system determines there is a collision risk between the vehicle and the preceding vehicle. If the operating voltage does not reach a preset operating voltage threshold, a second activation signal is sent to the second solenoid valve 105, which increases the pressure in the wheel brake cylinder 106 via the second brake line 103 to achieve braking control.

[0050] The first solenoid valve 104 is used to receive the first activation signal from the main controller module 101 and control the duty cycle to adjust the volume of brake fluid flowing through the first brake line 102 into the brake wheel cylinder 106, thereby adjusting the boost rate and achieving the purpose of boost braking.

[0051] The second solenoid valve 105 is used to receive the second activation signal from the main controller module 101 and control the duty cycle to adjust the volume of brake fluid flowing through the second brake line 103 and into the brake wheel cylinder 106, thereby adjusting the boost rate and achieving the purpose of boost braking.

[0052] The following will describe in detail a braking control method provided by an embodiment of the present application in conjunction with specific implementation methods. Figure 2 A flowchart of a braking control method provided in an embodiment of the present application is shown in FIG. Figure 2 The specific steps are as follows:

[0053] Step 201: When a collision risk between the vehicle and the preceding vehicle is detected, the emergency braking function is activated.

[0054] In practice, when a vehicle is traveling on a heavily trafficked road or when the vehicle ahead is driving erratically or suddenly comes to a standstill, there is a high risk of collision between the vehicle ahead and the vehicle ahead. The vehicle's automatic emergency braking function will alert the driver to the risk of collision. If the driver does not respond, or if the risk of collision still exists despite the driver's response, the electronic stability system will automatically increase the pressure and apply automatic braking measures to mitigate or avoid the collision. Therefore, when the vehicle detects a risk of collision with the vehicle ahead, it will activate the emergency braking function.

[0055] Furthermore, the specific steps for a vehicle to detect whether there is a collision risk between the vehicle and the vehicle ahead are as follows.

[0056] Step 1: Obtain the second speed of the vehicle, the first acceleration of the vehicle, the relative distance between the vehicle and the preceding vehicle, the third speed of the preceding vehicle, and the second acceleration of the preceding vehicle.

[0057] In practice, when a vehicle is traveling on a road with heavy traffic or when the vehicle ahead is driving erratically or suddenly stops, there is a high risk of collision between the vehicle ahead and the vehicle ahead. Therefore, the vehicle needs to determine in real time whether there is a collision risk between the vehicle ahead and the vehicle ahead. If the vehicle ahead and the vehicle ahead are traveling on the same route and there is a relative distance between them, there is no collision risk when the vehicle's second speed is less than or equal to the vehicle ahead's third speed and the vehicle ahead's first acceleration is less than or equal to the vehicle ahead's second acceleration. However, if at least one of the vehicle's second speed and first acceleration is greater than the vehicle ahead's third speed or second acceleration, there may be a collision risk between the vehicle ahead and the vehicle ahead. Therefore, the vehicle's collision risk can be determined based on the vehicle's speed, acceleration, relative distance between the vehicle ahead and the vehicle ahead, and the vehicle ahead's speed and acceleration. Therefore, when determining whether a vehicle will collide with the vehicle ahead while driving, it is necessary to first obtain the vehicle's second speed, the vehicle's first acceleration, the relative distance between the vehicle ahead and the vehicle ahead, the vehicle's third speed, and the vehicle ahead's second acceleration. The vehicle can use a wheel speed sensor to collect the vehicle's wheel speed and a steering wheel angle sensor to collect the vehicle's steering wheel angle. The vehicle's second speed is then determined based on the wheel speed and steering wheel angle. The vehicle can also use a lateral acceleration sensor to collect the vehicle's lateral acceleration and a yaw rate sensor to collect the vehicle's centrifugal force. The vehicle's first acceleration is then determined based on the lateral acceleration and centrifugal force. The vehicle's information collection device is used to obtain the vehicle's third speed and second acceleration, as well as the relative distance between the vehicle ahead and the vehicle ahead. The information collection device can be a camera.

[0058] Step 2: Determine the time to collision TTC between the vehicle and the preceding vehicle based on the second vehicle speed, the third vehicle speed, the first acceleration, the second acceleration, and the relative distance.

[0059] In practice, the vehicle obtains the second and third speeds, the first and second accelerations, and the relative distance to determine the TTC (Time-To-Collision) between the vehicle and the preceding vehicle. TTC represents the time it would take for the two vehicles to collide if they continued to collide at their current speeds and along the same path. In other words, if the vehicle is traveling at the second speed and the first acceleration, and the preceding vehicle is traveling at the third speed and the second acceleration, the actual time it would take for the two vehicles to collide.

[0060] As an optional implementation, a formula for determining the time to collision TTC between the vehicle and the preceding vehicle is as follows based on the second vehicle speed, the third vehicle speed, the first acceleration, the second acceleration, and the relative distance:

[0061]

[0062] Among them, TTC represents the collision time between the vehicle and the preceding vehicle, △s represents the relative distance between the vehicle and the preceding vehicle, △v represents the speed difference between the second speed and the third speed, and △a represents the acceleration difference between the first acceleration and the second acceleration.

[0063] In practice, when △a=0, it means that the acceleration of this vehicle and the preceding vehicle is the same or both are 0. △v<0, it means that the second speed of this vehicle is less than the third speed of the preceding vehicle. That is, s1=v1*t, v1 represents the second speed, and s1 represents the distance traveled by this vehicle at the second speed. s2=v2*t, v2 represents the third speed, and s2 represents the distance traveled by the preceding vehicle at the third speed. When this vehicle collides with the preceding vehicle, that is, when s1-s2=0, that is, s1-s2=(v1-v2)*t, that is, t=(s1-s2) / (v1-v2), and △s=s1-s2, △v=v1-v2, and because the second speed of this vehicle is less than the third speed of the preceding vehicle, the collision time must be a positive number, so TTC=-△s / △v.

[0064] When △a≠0, it means that the acceleration of the vehicle in front is not equal to that of the vehicle in front. It may be that the first acceleration of the vehicle in front is greater, or the second acceleration of the vehicle in front is greater. △v<0, it means that the second speed of the vehicle in front is less than the third speed of the vehicle in front. In other words, s1=v1*t+1 / 2*a1*t 2 , v1 represents the second vehicle speed, a1 represents the first acceleration of the vehicle, and s1 represents the distance traveled by the vehicle at the second vehicle speed. s2=v2*t+1 / 2*a2*t 2 , v2 represents the third speed of the preceding vehicle, a2 represents the second acceleration of the preceding vehicle, and s2 represents the distance traveled by the preceding vehicle at the third speed. When the vehicle collides with the preceding vehicle, that is, when s1-s2=0, s1-s2=(v1-v2)*t+1 / 2*(a1-a2)*t 2 ,Right now And since the second speed of the vehicle is less than the third speed of the vehicle in front, and the collision time must be a positive number,

[0065] When △a<0, it means that the first acceleration of the vehicle is less than the second acceleration of the vehicle in front. △v≥0, it means that the second speed of the vehicle in front is greater than or equal to the third speed of the vehicle in front. In other words, s1=v1*t+1 / 2*a1*t 2 , v1 represents the second vehicle speed, a1 represents the first acceleration of the vehicle, and s1 represents the distance traveled by the vehicle at the second vehicle speed. s2=v2*t+1 / 2*a2*t 2 , v2 represents the third vehicle speed, a2 represents the second acceleration of the preceding vehicle, and s2 represents the distance traveled by the preceding vehicle at the third vehicle speed. When the vehicle collides with the preceding vehicle, that is, when s1-s2=0, s1-s2=(v1-v2)*t+1 / 2*(a1-a2)*t2 ,Right now And since the first acceleration of the vehicle is less than the second acceleration of the preceding vehicle, and the collision time must be a positive number,

[0066]

[0067] Furthermore, when the vehicle is turning, if the vehicle's speed and turning radius are too small, the vehicle does not trigger the emergency braking function and does not calculate TTC. The TTC value is usually fixed at 10, a value far greater than the TTC threshold. Since the TTC value is far greater than the TTC threshold at this time, the emergency braking function will not be triggered. TTC calculation is performed when the vehicle speed exceeds 5m / s.

[0068] Step three: Determine a target TTC threshold corresponding to the speed difference between the first speed and the third speed in the pre-stored correspondence between the speed difference between the host vehicle and the preceding vehicle and the TTC threshold.

[0069] During implementation, technicians pre-determine the time it would take for a collision to occur if the two vehicles continued traveling at their current speeds and along the same path, based on the speed differences between the vehicle and the preceding vehicle. This collision time is then determined as the TTC threshold. The vehicle's main controller module then stores the correspondence between the speed differences between the vehicle and the preceding vehicle and the TTC thresholds. Based on the speed difference between the vehicle's first speed and the preceding vehicle's third speed, the vehicle's main controller module searches for the target TTC threshold corresponding to the speed difference between the first and third speeds within this correspondence. Table 1 shows the correspondence between speed differences and TTC thresholds.

[0070] Table 1

[0071]

[0072] Step 4: If the TTC is less than or equal to the target TTC threshold, it is determined that there is a risk of collision between the vehicle and the vehicle in front, and the emergency braking function is activated. Otherwise, it is determined that there is no risk of collision between the vehicle and the vehicle in front, and the vehicle continues to be controlled at the first speed.

[0073] During implementation, the TTC is compared with the target TTC threshold. If the TTC is less than or equal to the target TTC threshold, it indicates that the vehicle is traveling at the second speed and the first acceleration, while the preceding vehicle is continuing at the third speed and the second acceleration. The time between the two vehicles colliding is shorter than the target TTC threshold, so there is a certain risk of collision between the two vehicles. In this case, the vehicle's emergency braking function needs to be activated. If the TTC is greater than the target TTC threshold, it indicates that the vehicle continues traveling at the second speed and the first acceleration and will not collide with the preceding vehicle traveling at the third speed and the second acceleration. In other words, if the TTC is greater than the target TTC threshold, it is determined that there is no risk of collision between the vehicle and the preceding vehicle, and the vehicle continues to be controlled at the first speed.

[0074] Furthermore, after turning on the emergency braking function, it is necessary to reduce the speed of the vehicle to a target safe speed that will not collide with the vehicle in front. Therefore, when braking, it is also necessary to determine the target safe speed of the vehicle and reduce the speed of the vehicle to the target safe speed so that the vehicle will not collide with the vehicle in front.

[0075] When the preceding vehicle brakes suddenly or the preceding vehicle's speed is zero, the target safe speed of the own vehicle is determined to be zero.

[0076] In practice, when the vehicle ahead performs emergency braking or reaches zero speed, in order to avoid collision, the target safe speed of the vehicle should be determined to be zero.

[0077] When the front vehicle is in a constant speed or accelerating state, the current speed of the front vehicle is used as the target safe speed, and the speed of the own vehicle is reduced to the target safe speed.

[0078] In practice, when the leading vehicle is at a constant speed or accelerating, as long as the speed of the host vehicle is less than or equal to the speed of the leading vehicle, a collision can be avoided. Therefore, the current speed of the leading vehicle can be used as the target safe speed, and the speed of the host vehicle can be reduced to the target safe speed.

[0079] Step 202 : After the emergency braking function is turned on, a first activation signal is sent to the first solenoid valve, the wheel cylinder is pressurized through the first brake line to implement braking control, and a first vehicle speed of the vehicle is obtained.

[0080] In practice, after the vehicle's emergency braking function is activated, the vehicle's main controller module sends a first activation signal to the first solenoid valve. Upon activation, the first solenoid valve opens, allowing brake fluid to flow through the first solenoid valve, through the first brake line, and into the wheel cylinder, thereby achieving boost braking. The first activation signal also includes the first solenoid valve's duty cycle. The main controller adjusts the volume of brake fluid flowing into the wheel cylinder by controlling the duty cycle of the first solenoid valve, thereby regulating the boost rate and further braking. After activating the emergency braking function, the vehicle must determine whether the emergency braking function is effective. If it is ineffective, there is a risk of collision between the vehicle and the preceding vehicle. If the emergency braking function is effective, the vehicle's speed must be reduced to the target safety speed, which is the maximum speed at which the vehicle will not collide with the preceding vehicle, provided the preceding vehicle's driving state remains unchanged. Therefore, to determine whether the emergency braking function is effective, the vehicle's first speed must be obtained.

[0081] Furthermore, if the first vehicle speed is greater than the target safety speed and less than the second vehicle speed, an alarm message indicating that the first brake line is blocked is output.

[0082] During implementation, the first vehicle speed is compared with the target safety speed and the second vehicle speed respectively. If the first vehicle speed is greater than the target safety speed and less than the second vehicle speed, it is determined that the emergency braking function has failed and the vehicle speed has not been reduced to the target safety speed. Because if the first vehicle speed is greater than the target safety speed and less than the second vehicle speed, it is determined that the vehicle is in emergency braking, but the braking is not complete, so the fault is the blockage of the first brake line. Because in the case of a blockage in the first brake line, there may still be a small amount of brake fluid flowing through the first brake line and into the brake wheel cylinder, but it is impossible to completely brake, so the first vehicle speed of the vehicle is equivalent to the second vehicle speed being slightly lower. Therefore, when the vehicle is emergency braked, the first vehicle speed of the vehicle is greater than the target safety speed and less than the second speed, and an alarm message indicating that the first brake line is blocked needs to be output to remind the driver to brake.

[0083] Step 203 : If the first vehicle speed is equal to the second vehicle speed, the operating voltage of the first solenoid valve is obtained; the second vehicle speed is the vehicle speed when the electronic stability system determines that there is a risk of collision between the vehicle and the preceding vehicle.

[0084] In practice, the first vehicle speed is compared with the second vehicle speed. If the first vehicle speed equals the second vehicle speed, it indicates that the vehicle has not slowed down at all. In other words, after the emergency brake function is activated, brake fluid has not flowed from the hydraulic pump to the wheel brake cylinders. Therefore, the emergency brake function can be determined to be completely ineffective. The second vehicle speed is the vehicle speed at which the electronic stability system determines there is a risk of collision with the vehicle ahead. If the hydraulic pump fails, it cannot deliver brake fluid to the first solenoid valve port, rendering the emergency brake function completely ineffective. The emergency brake solenoid valve device may age due to frequent vehicle use, resulting in a failure of the vehicle during braking. If the first solenoid valve fails, it cannot control the valve opening, preventing brake fluid from entering the wheel brake cylinders, rendering the emergency brake function completely ineffective. Therefore, if the first vehicle speed equals the second vehicle speed, the emergency brake function failure may be due to a hydraulic pump failure or a first solenoid valve failure. To further confirm the failure, it is possible to determine whether the first solenoid valve is functioning properly. If the first solenoid valve is functioning properly, the emergency brake function failure is due to a hydraulic pump failure. In order to determine whether the first solenoid valve is in normal operation, the operating voltage of the first solenoid valve may be obtained and the operating voltage of the first solenoid valve may be determined.

[0085] Step 204 : If the operating voltage does not reach the preset operating voltage threshold, a second activation signal is sent to the second solenoid valve to increase the pressure of the wheel cylinder through the second brake line to achieve braking control.

[0086] During implementation, the solenoid valve device for emergency braking may have aging problems, resulting in the vehicle being unable to brake successfully during braking. Therefore, when troubleshooting the emergency braking function failure, it is possible to determine whether the working voltage of the first solenoid valve is the normal working voltage, and then determine whether the solenoid valve is in a normal working state. The obtained working voltage of the first solenoid valve is compared with the preset working voltage threshold. If the working voltage does not reach the preset working voltage threshold, it means that the first solenoid valve has failed, and the cause of the emergency braking function failure is the failure of the first solenoid valve. In order to avoid functional impairment of the vehicle's emergency braking function due to aging problems of the solenoid valve in the vehicle, a second solenoid valve device can be set in the vehicle to serve as a backup. When a failure of the first solenoid valve is detected, the main controller can send a second activation signal to the second solenoid valve, and pressurize the brake wheel cylinder through the second brake line to achieve braking control.

[0087] Furthermore, if the operating voltage reaches a preset operating voltage threshold, an alarm message of the vehicle's hydraulic pump is output.

[0088] An embodiment of the present application provides a braking control method, when a vehicle is driving and it is detected that there is a risk of collision between the vehicle and the vehicle in front, the automatic emergency braking function of the vehicle is turned on. The first solenoid valve is activated and the brake wheel cylinder is pressurized to brake. Then the current speed of the vehicle is obtained. If the current speed is equal to the speed when there is a risk of collision between the vehicle and the vehicle in front, then it is necessary to obtain the working voltage of the first solenoid valve to determine whether the first solenoid valve is faulty. If it is a fault of the first solenoid valve, then the second solenoid valve is activated to ensure the braking control of the vehicle. In this way, functional impairment of the automatic emergency braking function caused by aging of the solenoid valve can be avoided, which makes it impossible for the electronic stability system to brake normally, resulting in a collision between the vehicle and the vehicle in front.

[0089] It should be understood that although Figure 2 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. In addition, Figure 2 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily performed at the same time, but can be performed at different times. The order of execution of these steps or stages is not necessarily one by one, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0090] It can be understood that the same / similar parts between the various embodiments of the above method in this specification can be referred to each other, and each embodiment focuses on the differences from other embodiments. For related parts, please refer to the description of other method embodiments.

[0091] The present application also provides a braking control device, such as Figure 3 As shown, the device includes:

[0092] The activation module 301 is used to activate the emergency braking function when a collision risk between the vehicle and the preceding vehicle is detected;

[0093] a first sending module 302 configured to send a first activation signal to the first solenoid valve after the emergency braking function is activated, thereby increasing the pressure of the wheel cylinder via the first brake line to achieve braking control, and to obtain a first vehicle speed of the vehicle;

[0094] A first acquisition module 303 is configured to acquire an operating voltage of the first solenoid valve if the first vehicle speed is equal to a second vehicle speed; the second vehicle speed is the vehicle speed of the vehicle when the electronic stability system determines that there is a risk of collision between the vehicle and the preceding vehicle;

[0095] The second sending module 304 is configured to send a second activation signal to the second solenoid valve if the operating voltage does not reach a preset operating voltage threshold, so as to increase the pressure of the wheel cylinder via the second brake line to achieve braking control.

[0096] As an optional implementation, the device further includes:

[0097] a third acquisition module, configured to acquire the second speed of the host vehicle, the first acceleration of the host vehicle, the relative distance between the host vehicle and the preceding vehicle, the third speed of the preceding vehicle, and the second acceleration of the preceding vehicle;

[0098] a first determining module, configured to determine a time to collision TTC between the host vehicle and the preceding vehicle based on the second vehicle speed, the third vehicle speed, the first acceleration, the second acceleration, and the relative distance;

[0099] a second determining module, configured to determine a target TTC threshold value corresponding to the speed difference between the first vehicle speed and the third vehicle speed from a pre-stored correspondence between the speed difference between the host vehicle and the preceding vehicle and the TTC threshold value;

[0100] a determination module configured to determine that there is a risk of collision between the vehicle and the preceding vehicle if the TTC is less than or equal to the target TTC threshold and activate an emergency braking function; otherwise, determine that there is no risk of collision between the vehicle and the preceding vehicle and continue to control the vehicle to travel at the first vehicle speed.

[0101] As an optional implementation manner, the first sending module is further configured to:

[0102] When the preceding vehicle brakes suddenly or the preceding vehicle's speed is zero, the target safe speed of the own vehicle is determined to be zero;

[0103] When the preceding vehicle is in a constant speed or accelerating state, the current speed of the preceding vehicle is used as the target safe speed, and the speed of the host vehicle is reduced to the target safe speed.

[0104] As an optional implementation manner, if the first vehicle speed is less than the second vehicle speed and greater than the target safe vehicle speed, an alarm message indicating that the first brake line is blocked is output.

[0105] An embodiment of the present application provides a braking control device. When the vehicle is driving and it is detected that there is a risk of collision between the vehicle and the vehicle in front, the automatic emergency braking function of the vehicle is turned on. The first solenoid valve is activated and the brake wheel cylinder is pressurized to brake. Then the current speed of the vehicle is obtained. If the current speed is equal to the speed when there is a risk of collision between the vehicle and the vehicle in front, it is necessary to obtain the working voltage of the first solenoid valve to determine whether the first solenoid valve is faulty. If it is a fault of the first solenoid valve, the second solenoid valve is activated to ensure the braking control of the vehicle. In this way, functional impairment of the automatic emergency braking function caused by aging of the solenoid valve can be avoided, which makes it impossible for the electronic stability system to brake normally, resulting in a collision between the vehicle and the vehicle in front.

[0106] The specific definition of the brake control device can be found in the definition of the brake control method above and will not be repeated here. Each module in the brake control device described above may be implemented in whole or in part through software, hardware, or a combination thereof. Each module may be embedded in or independent of a processor in a computer device in hardware form, or may be stored in a computer device memory in software form, so that the processor can call and execute the corresponding operations of each module.

[0107] In one embodiment, a computer device is provided, such as Figure 4 As shown, it includes a memory and a processor, the memory stores a computer program that can be run on the processor, and the processor implements the above-mentioned braking control method steps when executing the computer program.

[0108] In one embodiment, a computer-readable storage medium stores a computer program, which implements the steps of the above-mentioned brake control method when executed by a processor.

[0109] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0110] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0111] It should also be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for display, data for analysis, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0112] Each embodiment in this specification is described in a related manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiment is generally similar to the method embodiment, so the description is relatively simple. For related parts, refer to the description of the method embodiment.

[0113] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0114] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A braking control method, characterized in that: The method is applied to an electronic stability system of a vehicle, wherein a first solenoid valve is provided on a first brake line of a wheel cylinder of the vehicle, and a second solenoid valve is provided on a second brake line. The method comprises: When a collision risk is detected between the vehicle and the vehicle ahead, the emergency braking function is activated; After the emergency braking function is activated, a first activation signal is sent to the first solenoid valve, the wheel cylinder is pressurized via the first brake line to implement braking control, and a first vehicle speed of the vehicle is obtained; If the first vehicle speed is equal to a second vehicle speed, obtaining the operating voltage of the first solenoid valve; the second vehicle speed is the vehicle speed of the vehicle when the electronic stability system determines that there is a risk of collision between the vehicle and the preceding vehicle; If the operating voltage does not reach the preset operating voltage threshold, a second activation signal is sent to the second solenoid valve to increase the pressure of the brake wheel cylinder through the second brake line to achieve braking control.

2. The method according to claim 1, characterized in that The method further comprises: Obtaining a second vehicle speed of the host vehicle, a first acceleration of the host vehicle, a relative distance between the host vehicle and the preceding vehicle, a third vehicle speed of the preceding vehicle, and a second acceleration of the preceding vehicle; determining a time to collision TTC between the host vehicle and the preceding vehicle based on the second vehicle speed, the third vehicle speed, the first acceleration, the second acceleration, and the relative distance; Determining a target TTC threshold value corresponding to the speed difference between the first vehicle speed and the third vehicle speed in a pre-stored correspondence between the speed difference between the host vehicle and the preceding vehicle and the TTC threshold value; If the TTC is less than or equal to the target TTC threshold, it is determined that there is a risk of collision between the vehicle and the preceding vehicle, and the emergency braking function is activated; otherwise, it is determined that there is no risk of collision between the vehicle and the preceding vehicle, and the vehicle continues to be controlled to travel at the first vehicle speed.

3. The method according to claim 2, characterized in that The formula for determining the collision time TTC between the host vehicle and the preceding vehicle based on the second vehicle speed, the third vehicle speed, the first acceleration, the second acceleration, and the relative distance is: Among them, TTC represents the collision time between the vehicle and the preceding vehicle, △s represents the relative distance between the vehicle and the preceding vehicle, △v represents the speed difference between the second speed and the third speed, and △a represents the acceleration difference between the first acceleration and the second acceleration.

4. The method according to claim 1, wherein After the emergency braking function is activated, the method further includes: When the preceding vehicle brakes suddenly or the preceding vehicle's speed is zero, the target safe speed of the own vehicle is determined to be zero; When the preceding vehicle is in a constant speed or accelerating state, the current speed of the preceding vehicle is used as the target safe speed, and the speed of the host vehicle is reduced to the target safe speed.

5. The method according to claim 1, wherein If the first vehicle speed is less than the second vehicle speed and greater than a target safe vehicle speed, an alarm message indicating that the first brake line is blocked is output.

6. The method according to claim 1, characterized in that If the operating voltage reaches a preset operating voltage threshold, an alarm message of the hydraulic pump of the vehicle is output.

7. A brake control device, characterized in that: The device is applied to an electronic stability system of a vehicle, wherein a first solenoid valve is provided on a first brake line of a wheel cylinder of the vehicle, and a second solenoid valve is provided on a second brake line. The device comprises: The activation module is used to activate the emergency braking function when a collision risk between the vehicle and the vehicle in front is detected; a first sending module, configured to send a first activation signal to the first solenoid valve after the emergency braking function is activated, to pressurize the wheel cylinder via the first brake line to achieve braking control, and to obtain a first vehicle speed of the vehicle; a first acquisition module, configured to acquire an operating voltage of the first solenoid valve if the first vehicle speed is equal to a second vehicle speed; the second vehicle speed being the vehicle speed of the vehicle when the electronic stability system determines that there is a risk of collision between the vehicle and the preceding vehicle; The second sending module is used to send a second activation signal to the second solenoid valve if the working voltage does not reach a preset working voltage threshold, so as to increase the pressure of the brake wheel cylinder through the second brake line to achieve braking control.

8. The device according to claim 7, characterized in that The device further comprises: a second acquisition module, configured to acquire a second vehicle speed of the host vehicle, a first acceleration of the host vehicle, a relative distance between the host vehicle and the preceding vehicle, a third vehicle speed of the preceding vehicle, and a second acceleration of the preceding vehicle; a first determining module, configured to determine a time to collision TTC between the host vehicle and the preceding vehicle based on the second vehicle speed, the third vehicle speed, the first acceleration, the second acceleration, and the relative distance; a second determining module, configured to determine a target TTC threshold value corresponding to the speed difference between the first vehicle speed and the third vehicle speed from a pre-stored correspondence between the speed difference between the host vehicle and the preceding vehicle and the TTC threshold value; a determination module configured to determine that there is a risk of collision between the vehicle and the preceding vehicle if the TTC is less than or equal to the target TTC threshold and activate an emergency braking function; otherwise, determine that there is no risk of collision between the vehicle and the preceding vehicle and continue to control the vehicle to travel at the first vehicle speed.

9. The device according to claim 7, characterized in that The first sending module is further configured to: When the preceding vehicle brakes suddenly or the preceding vehicle's speed is zero, the target safe speed of the own vehicle is determined to be zero; When the preceding vehicle is in a constant speed or accelerating state, the current speed of the preceding vehicle is used as the target safe speed, and the speed of the host vehicle is reduced to the target safe speed.

10. The device according to claim 7, characterized in that If the first vehicle speed is less than the second vehicle speed and greater than a target safe vehicle speed, an alarm message indicating that the first brake line is blocked is output.

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