Emergency braking method, vehicle and storage medium

Abstract

The invention provides an emergency braking method, a vehicle and a storage medium, the method is applied to the field of vehicles, and the method comprises the steps that the slip rate of each wheel during emergency braking of the vehicle is obtained; calculating the target braking force of the corresponding wheel according to the slip rate of each wheel and the emergency braking force of the vehicle; and controlling the braking mechanism of each wheel to output the corresponding target braking force. According to the method, when the vehicle automatically triggers emergency braking or a driver actively triggers emergency braking, the target braking force of the corresponding wheels can be calculated according to the slip rates of the different wheels and the emergency braking force of the vehicle, and the braking mechanism of each wheel is controlled to output the corresponding target braking force, so that emergency braking of the vehicle is achieved. By controlling the braking force of each wheel, the stability during emergency braking is improved, and out-of-control or sideslip of the vehicle direction is avoided.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and more specifically, to an emergency braking method, a vehicle and a storage medium in the field of vehicle braking. Background Art

[0002] Emergency braking refers to when a vehicle encounters an emergency while driving, such as a pedestrian suddenly rushing out from the side of the vehicle during normal driving or the vehicle in front suddenly brakes, etc. The driver needs to brake quickly and correctly to ensure that the vehicle stops in the shortest distance to avoid an accident. Emergency braking can be automatically triggered by the vehicle or actively triggered by the driver.

[0003] Taking the example of the driver actively triggering emergency braking, in an emergency situation, the driver usually needs to step on the brake pedal quickly and forcefully, and then the hydraulic pipeline in the braking system quickly builds pressure, and the front and rear brake calipers quickly push out the piston to clamp the brake disc under the action of hydraulic pressure to achieve emergency braking.

[0004] However, the braking systems of related technologies are mostly hydraulic braking. In emergency situations, the vehicle's braking force is usually large, but since the front and rear brake caliper hydraulic pipelines are the same, the front and rear brake clamping force and pipeline hydraulic pressure are basically linearly related, so that the braking force of all wheels is consistent during emergency braking, causing the vehicle to lose control of the direction or skid in an emergency. Summary of the invention

[0005] The present application provides an emergency braking method, a vehicle and a storage medium. The method can calculate the target braking force of the corresponding wheel according to the slip rate of different wheels and the emergency braking force of the vehicle when the vehicle automatically triggers the emergency braking or the driver actively triggers the emergency braking, and control the braking mechanism of each wheel to output the corresponding target braking force to achieve emergency braking of the vehicle. Through the independent control and adjustment of the braking force of each wheel, the stability during emergency braking is improved to avoid the vehicle from losing control of the direction or skidding.

[0006] In a first aspect, an emergency braking method is provided, the method comprising: obtaining the slip rate of each wheel of the vehicle during emergency braking; calculating the target braking force of the corresponding wheel based on the slip rate of each wheel and the emergency braking force of the vehicle; and controlling the braking mechanism of each wheel to output the corresponding target braking force.

[0007] Through the above technical scheme, the embodiment of the present application can calculate the target braking force of the corresponding wheel according to the slip rate of different wheels and the emergency braking force of the vehicle when the vehicle automatically triggers emergency braking or the driver actively triggers emergency braking, and control the braking mechanism of each wheel to output the corresponding target braking force to achieve emergency braking of the vehicle. It can achieve independent control and adjustment of the braking force of each wheel, thereby improving the stability of emergency control and avoiding loss of control or sideslip of the vehicle.

[0008] In combination with the first aspect, in certain possible implementations, the control of the braking mechanism of each wheel to output the corresponding target braking force includes: obtaining the current braking force of each wheel; and controlling the output target current of the caliper motor in the corresponding braking mechanism according to the current braking force of each wheel and the corresponding target braking force.

[0009] Through the above technical solution, the embodiment of the present application can control the output target current of the caliper motor in the corresponding braking mechanism according to the current braking force and the corresponding target braking force, so as to realize emergency braking of the vehicle.

[0010] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the target braking force of the corresponding wheel is calculated based on the slip rate of each wheel and the emergency braking force of the vehicle, including: inputting the slip rate of each wheel and the emergency braking force of the vehicle into a closed-loop processing model, and the closed-loop processing model outputs the target braking force of the corresponding wheel.

[0011] Through the above technical solution, the embodiment of the present application can calculate the target braking force of the corresponding wheel according to the slip rate of each wheel and the emergency braking force input closed-loop processing model of the vehicle, so as to facilitate the subsequent control of the braking mechanism of each wheel to output the corresponding target braking force.

[0012] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the target braking force of the corresponding wheel is calculated based on the slip rate of each wheel and the emergency braking force of the vehicle, and also includes: identifying whether the caliper motor of each wheel has failed; when at least one caliper motor is identified to have failed, the slip rate of the wheel corresponding to each non-failed caliper motor and the emergency braking force of the vehicle are input into a closed-loop processing model, and the closed-loop processing model outputs the target braking force of the wheel corresponding to each non-failed caliper motor.

[0013] Through the above technical scheme, when the failure of any caliper motor is identified, the embodiment of the present application can calculate the target braking force of each vehicle based on the slip rate of the wheel corresponding to the non-failed caliper motor and the vehicle's emergency braking force input closed-loop processing model, so as to facilitate the subsequent control of the braking mechanism of each wheel to output the corresponding target braking force.

[0014] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the closed-loop processing model uses a closed-loop processing algorithm to perform data processing, wherein the closed-loop processing algorithm includes: if the slip rate of the wheel is less than or equal to a preset value, the emergency braking force is used as the target braking force of the corresponding wheel; if the slip rate of the wheel is greater than the preset value, then when the actual yaw rate of the vehicle is detected and the slip rate is not the longitudinal slip rate, the target braking force of the corresponding wheel is calculated based on the angular velocity difference between the actual yaw rate and the target yaw rate and the emergency braking force, otherwise the target braking force of the corresponding wheel is calculated based on the longitudinal slip rate and the emergency braking force.

[0015] Through the above technical solution, the embodiment of the present application can process data based on the closed-loop processing algorithm in the closed-loop processing model, so as to calculate the target braking force of each wheel according to the actual situation, so as to facilitate the subsequent control of the braking mechanism of each wheel to output the corresponding target braking force.

[0016] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, when any caliper motor failure is identified, it also includes: obtaining the number and location of caliper motor failures; matching the target speed limit of the vehicle according to the number and / or location of caliper motor failures; and controlling the speed of the vehicle within the target speed limit.

[0017] Through the above technical solution, the embodiment of the present application can limit the speed of the vehicle according to the actual situation when any caliper motor fails, so that the vehicle speed is within a safe range, thereby improving the safety of the vehicle.

[0018] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, before calculating the target braking force of the corresponding wheel based on the slip rate of each wheel and the emergency braking force of the vehicle, it also includes: obtaining the driver's braking force and the rate of change slope of the driver's braking force; calculating the corresponding emergency braking force based on the driver's braking force and the driver's rate of change slope.

[0019] Through the above technical solution, the embodiment of the present application can calculate the emergency braking force based on the driver's braking force and the slope of the rate of change when the driver actively triggers emergency braking, so as to facilitate the subsequent calculation of the target braking force of the corresponding wheel.

[0020] In combination with the first aspect and the above-mentioned implementations, in some possible implementations, obtaining the slip rate of each wheel of the vehicle when braking also includes: obtaining the actual wheel speed of each wheel; and calculating the slip rate of the corresponding wheel according to the actual wheel speed of each wheel.

[0021] Through the above technical solution, the embodiment of the present application can calculate the slip rate of the corresponding wheel based on the actual wheel speed of each wheel, so as to subsequently calculate the target braking force of the corresponding wheel according to the slip rate and emergency braking force of each wheel.

[0022] In a second aspect, an emergency braking device is provided, which includes: an acquisition module for acquiring the slip rate of each wheel of the vehicle during emergency braking; a calculation module for calculating the target braking force of the corresponding wheel based on the slip rate of each wheel and the emergency braking force of the vehicle; and a control module for controlling the braking mechanism of each wheel to output the corresponding target braking force.

[0023] In a third aspect, a vehicle is provided, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the emergency braking method as described in the above embodiment.

[0024] In a fourth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed, the emergency braking method as described in the above embodiment is implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a flow chart of the emergency braking method provided in an embodiment of the present application;

[0026] Figure 2 is a block diagram of an emergency brake device provided in an embodiment of the present application;

[0027] Figure 3 It is a schematic diagram of the structure of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0029] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0030] The following will be combined Figure 1 The emergency braking method is explained in detail.

[0031] Figure 1 It is a schematic flow chart of an emergency braking method provided in an embodiment of the present application.

[0032] For example, Figure 1 As shown, the vehicle independently controls each wheel based on an electromechanical braking system, wherein the method includes:

[0033] In step S101 , the slip rate of each wheel of the vehicle during emergency braking is obtained.

[0034] It is understandable that the emergency braking of the embodiment of the present application can be a condition where the vehicle automatically triggers braking in an emergency or a condition where the driver actively triggers braking when emergency braking is required. Taking the condition where the vehicle automatically triggers braking in an emergency as an example, when the vehicle is driving normally, there is a blind spot in the field of vision due to the obstruction of the left and right vehicles. If a pedestrian or vehicle suddenly appears, the vehicle's sensor detects the distance to the pedestrian or vehicle in time, and the vehicle automatically triggers emergency braking. The above situation is not specifically limited, and it can be determined whether emergency braking needs to be triggered according to actual conditions. The embodiment of the present application can obtain the slip rate of each wheel when emergency braking is triggered.

[0035] It should be noted that the chassis structure of the vehicle in the embodiment of the present application mainly includes four EMB (Electromechanical Brake System) actuators, which can independently control the four wheels; EMB is an actuator driven by a caliper motor and installed on the caliper of the brake mechanism. It is a device that directly brakes the vehicle with the brake mechanism without the need for a medium such as brake fluid; EMB replaces traditional hydraulic brakes and is used for main braking, and its scope of use has been expanded.

[0036] When the wheel exerts traction or braking force, there will be relative motion between the wheel and the ground. The slip rate is the proportion of the sliding component in the wheel motion. The formula is defined as follows:

[0037] s=(uu w ) / u×100%=(u-rω) / u×100%

[0038] Where, u is the vehicle speed; u w is the wheel speed; ω is the wheel rolling angular velocity; r is the wheel radius.

[0039] When the wheel is rolling, u w =u, s = 0; when the wheel is locked and sliding, u w =0, s=100%; when the wheel rolls and slides, u>uw , 0 < s < 100%; the larger the wheel slip ratio, the greater the proportion of the sliding component in the wheel movement.

[0040] In the embodiments of the present application, the slip ratio of each wheel of the vehicle can be obtained in real time through a sensor to determine the wheel slip ratio; or the slip ratio of the wheel can be determined according to the current wheel speed and the current reference vehicle speed of each wheel; or by constructing a wheel dynamics equation including the wheel driving torque and speed to express the adhesion characteristics between the wheel and the road surface, and detecting the wheel slip state by calculating the derivative change, so as to obtain the slip ratio corresponding to the maximum adhesion coefficient, which is not specifically limited.

[0041] As a possible implementation manner, obtaining the slip ratio of each wheel of the vehicle during braking includes: obtaining the actual wheel speed of each wheel; calculating the slip ratio of the corresponding wheel according to the actual wheel speed of each wheel.

[0042] It can be understood that since the relevant parameters of the tire, such as tire pressure, tire quality, and tire wear degree, will directly affect the wheel speed of each wheel, therefore, in the embodiments of the present application, the slip ratio can be calculated according to the wheel speed, and the braking force can be accurately controlled through the slip ratio, so as to effectively overcome the influence of the relevant parameters on the braking force.

[0043] In step S102, calculate the target braking force of the corresponding wheel according to the slip ratio of each wheel and the emergency braking force of the vehicle.

[0044] It can be understood that since the slip ratio will affect the braking effect and the slip ratio of each wheel may be different, therefore, in the embodiments of the present application, when the vehicle meets the emergency braking condition, calculate the target braking force of the corresponding wheel according to the slip ratio of each wheel and the emergency braking force of the vehicle, so as to accurately determine the target braking force of each wheel.

[0045] As a possible implementation manner, calculating the target braking force of the corresponding wheel according to the slip ratio of each wheel and the emergency braking force of the vehicle includes: inputting the slip ratio of each wheel and the emergency braking force of the vehicle into a closed-loop processing model, and the closed-loop processing model outputs the target braking force of the corresponding wheel.

[0046] It can be understood that in the embodiments of the present application, the slip ratio of each wheel and the emergency braking force of the vehicle can be input into the closed-loop processing model to calculate the target braking force of the corresponding wheel, so as to facilitate subsequent control of the braking mechanism of each wheel to output the corresponding target braking force.

[0047] As another possible implementation method, the target braking force of the corresponding wheel is calculated based on the slip rate of each wheel and the emergency braking force of the vehicle, and also includes: identifying whether there is a wheel with a failed caliper motor; when at least one caliper motor failure is identified, the slip rate of each non-failed caliper motor corresponding to the wheel and the emergency braking force of the vehicle are input into a closed-loop processing model, and the closed-loop processing model outputs the target braking force of each non-failed caliper motor corresponding to the wheel.

[0048] It can be understood that when the caliper motor fails, the embodiment of the present application can input the slip rate of the wheel corresponding to the non-failed caliper motor and the emergency braking force of the vehicle into the closed-loop processing model, thereby calculating the target braking force of the wheel corresponding to the non-failed caliper motor, so as to facilitate the subsequent control of the braking mechanism of the wheel corresponding to the non-failed side caliper motor to output the target braking force, use the non-failed side caliper motor to brake, and improve the robustness of braking.

[0049] In an embodiment of the present application, a closed-loop processing model uses a closed-loop processing algorithm to perform data processing, wherein the closed-loop processing algorithm includes: if the slip rate of the wheel is less than or equal to a preset value, the emergency braking force is used as the target braking force of the corresponding wheel; if the slip rate of the wheel is greater than or equal to the preset value, then when the actual yaw velocity of the vehicle is detected and the slip rate is not the longitudinal slip rate, the target braking force of the corresponding wheel is calculated based on the angular velocity difference between the actual yaw velocity and the target yaw velocity and the emergency braking force; otherwise, the target braking force of the corresponding wheel is calculated based on the longitudinal slip rate and the emergency braking force.

[0050] The preset value can be specifically calibrated according to the actual situation and the target yaw rate can be calculated according to the steering wheel angle and current vehicle speed of the vehicle. The yaw rate refers to the deflection of the vehicle around the vertical axis. The magnitude of the deflection represents the stability of the vehicle. If the yaw rate reaches a threshold, it means that the wheel is about to slip or drift, which is a dangerous condition.

[0051] It is understandable that the embodiments of the present application can utilize a closed-loop processing algorithm to perform data processing and calculate the target braking force based on whether the yaw angular velocity, longitudinal slip rate, etc. are generated when the vehicle brakes.

[0052] Specifically, when the wheel slip rate is small, the vehicle body will not usually produce tail swing, so the emergency braking force can be fully responded to; when the wheel slip rate is large, it is necessary to control the vehicle to execute the target braking force according to the actual situation. If the emergency braking force is fully responded, it is easy to cause the vehicle body to be unstable. Therefore, the embodiment of the present application also needs to correct the target braking force in combination with the yaw rate and / or the longitudinal slip rate, for example:

[0053] (1) When the actual yaw rate is greater than the target yaw rate, the angular velocity difference between the actual yaw rate and the target yaw rate is obtained; the braking force difference between the wheels on the left and right sides is determined according to the angular velocity difference, and the target braking force of the corresponding wheel is calculated according to the braking force difference and the emergency braking force;

[0054] The braking force difference is the braking force required to keep the vehicle stable. The actual yaw rate has positive and negative signs, so the vehicle body posture can be determined based on the positive and negative signs of the actual yaw rate. For example, a positive actual yaw rate is pre-calibrated to indicate a tilt to the left, and a negative actual yaw rate is pre-calibrated to indicate a tilt to the right, etc. This can be specifically calibrated.

[0055] Therefore, the embodiment of the present application can pre-calibrate the corresponding relationship between the angular velocity difference and the correction value of the emergency braking force. For example, when the angular velocity difference is A, the corresponding correction value of the emergency braking force is a N·m, and the specific corrected braking force of the vehicle can be determined according to the positive or negative of the actual yaw angular velocity. After correcting the emergency braking force based on the correction value, the target braking force can be obtained.

[0056] For example, when the left tilt needs to be corrected, the braking force difference of the left and right wheels can be determined according to the angular velocity difference, that is, the vehicle body remains stable by assigning different target braking forces to the wheels on both sides; assuming that the emergency braking force is 100N·m and the braking difference is 10N·m, the target braking force of the left wheel can be 90N·m, the target braking force of the right wheel can be 100N·m, and so on; of course, the braking force of the left wheel can also be appropriately reduced, for example, the target braking force of the left wheel can be 88N·m, and the target braking force of the right wheel can be 98N·m, and so on.

[0057] (2) The target braking force is corrected according to the longitudinal slip ratio. For example, the larger the longitudinal slip ratio, the lower the wheel lateral adhesion coefficient, so the corresponding target braking force needs to be smaller to avoid skidding; the smaller the longitudinal slip ratio, the higher the wheel lateral adhesion coefficient, so the corresponding target braking force can be larger. Therefore, the embodiment of the present application can determine the correction value of the emergency braking force according to the longitudinal slip ratio, and calculate the target braking force according to the correction value and the emergency braking force.

[0058] Therefore, the embodiment of the present application can pre-calibrate the corresponding relationship between the slip rate and the correction value of the emergency braking force. For example, when the slip rate is B, the corresponding correction value of the emergency braking force is bN·m, and the target braking force can be obtained by correcting the emergency braking force based on the correction value.

[0059] For example, when the current slip rate is detected as the longitudinal slip rate and the longitudinal slip rate is 30%, it means that the vehicle has a long sliding distance and the wheel lateral force adhesion coefficient is low, and the emergency braking force needs to be appropriately reduced. According to the correction value correspondence table of the longitudinal slip rate and the target braking force, the correction value of the target braking force can be determined. For example, by looking up the correspondence table, it can be determined that the correction value corresponding to the longitudinal slip rate of 30% is 20. When the emergency braking force is detected to be 100N, due to the large longitudinal slip rate, it is necessary to appropriately reduce the response to the emergency braking force, and the corresponding target braking force is 80N.

[0060] It should be noted that the closed-loop processing algorithm is applicable to the case where a caliper motor fails or all caliper motors are normal. The following will use the closed-loop processing model to calculate the target braking force of each wheel corresponding to the non-failed caliper motor as an example to illustrate the details as follows:

[0061] When the steering wheel is always deflected to one side or the brake disc shakes as a whole when the vehicle is braking, the caliper motor can be determined to be failed. When any caliper motor is detected to be failed, the longitudinal slip rate, emergency braking force, actual yaw angular velocity, vehicle speed, and steering wheel angle of the corresponding wheel of the non-failed caliper motor are input into the closed-loop processing model, and the target braking force of the corresponding wheel is output, including the following situations:

[0062] (1) When the steering wheel angle is constant, the emergency braking force is relatively small, which is not enough to cause the vehicle to yaw, and will not generate longitudinal slip. At this time, the target braking force of the non-failure caliper motor corresponding to the wheel fully responds to the emergency braking force;

[0063] (2) When the steering wheel angle is constant and the emergency braking force is large, the braking force is sufficient to make the vehicle produce a certain actual yaw velocity but the wheel will not have a longitudinal slip rate; the closed-loop processing model calculates the target yaw velocity based on the input signals such as the steering wheel angle and the vehicle speed. When the actual yaw velocity is greater than the target yaw velocity, the braking force required for vehicle body stability is determined based on the actual yaw velocity, and the angular velocity difference between the actual yaw velocity and the target yaw velocity is obtained; the braking force difference of the vehicle body on both sides is determined based on the angular velocity difference, and the target braking force of the wheel corresponding to the caliper motor of the non-failed wheel is calculated based on the braking difference and the emergency braking force. This algorithm has been described in the above method and will not be repeated here to avoid redundancy.

[0064] Specifically, in order to avoid the problem of inaccuracy in the target yaw rate calculation when the vehicle is in an unstable state, the embodiment of the present application obtains the steering wheel angle value after deviation compensation, the current vehicle speed, the characteristic vehicle speed, the wheelbase and the steering between the steering wheel angle and the wheel angle during the specific calculation, and calculates the target yaw rate based on the steering wheel angle value after deviation compensation, the current vehicle speed, the characteristic vehicle speed, the wheelbase and the steering between the steering wheel angle and the wheel angle, thereby improving the accuracy of the target yaw angle calculation, and the calculation method of the embodiment of the present application can also be applied to the calculation of the target yaw rate in a stable state, with better applicability. Among them, the formula for calculating the target yaw rate is as follows:

[0065]

[0066] Among them, w is the target yaw rate, a is the steering wheel angle value after deviation compensation, V1 is the current vehicle speed, V2 is the characteristic vehicle speed, l is the wheelbase, and α is the steering ratio between the steering wheel angle and the wheel angle, i.e. the steering characteristic. Among them, the characteristic vehicle speed is used to describe the parameters of the vehicle's understeering characteristics. When the vehicle speed reaches the preset value, the vehicle's steady-state angular velocity gain (the ratio of the yaw rate to the front wheel angle, also known as steering sensitivity) reaches the maximum value.

[0067] (3) When the steering wheel angle is constant and the emergency braking force is large, the emergency braking force can generate a longitudinal slip rate, regardless of whether the vehicle generates a yaw angular velocity. At this time, the closed-loop processing model calculates the target braking force of the non-failed caliper motor corresponding to the wheel based on the longitudinal slip rate and emergency braking force of each wheel.

[0068] It should be noted that since emergency braking can be a condition where the vehicle automatically triggers braking in an emergency or where the driver actively triggers braking when emergency braking is required, the emergency braking force can be calculated for both conditions by using the actual distance between the vehicle and the obstacle and the current vehicle speed detected by the sensor, or by using the braking force change rate of the driver, as follows:

[0069] As a possible implementation method, before calculating the target braking force of the corresponding wheel according to the slip rate of each wheel and the emergency braking force of the vehicle, it also includes: obtaining the actual distance between the vehicle and the obstacle; and determining the emergency braking force according to the actual distance and the current speed of the vehicle.

[0070] It can be understood that the embodiment of the present application detects the actual distance between the vehicle and the obstacle through the sensor, and the vehicle automatically triggers emergency braking. At this time, the emergency braking force is calculated based on the actual distance and the current vehicle speed to control the vehicle to stop in time.

[0071] Specifically, assuming that the vehicle is driving normally at this time, a pedestrian or vehicle suddenly appears and is not discovered in time due to a blind spot in the field of vision caused by the obstruction of the left and right vehicles. If the vehicle's sensors and other detection equipment detect the pedestrian or vehicle in time and the driver does not take any braking measures, the vehicle automatically enters emergency braking. At this time, the actual distance to the pedestrian or vehicle can be obtained through the distance sensor and the current speed of the vehicle can be obtained through the wheel speed sensor. The emergency braking force is calculated based on the actual distance and the current speed. The calculation formula is:

[0072] F=Mv^2 / 2S

[0073] Among them, S is the actual distance between the vehicle and the obstacle; v is the current speed, and M is the mass of the vehicle.

[0074] As another possible implementation method, before calculating the target braking force of the corresponding wheel based on the slip rate of each wheel and the emergency braking force of the vehicle, it also includes: obtaining the driver's braking force and the rate of change slope of the driver's braking force; calculating the corresponding emergency braking force based on the driver's braking force and the driver's rate of change slope.

[0075] It can be understood that the rate of change slope is used for the speed of change of the braking force. When the rate of change slope is large, the corresponding braking force changes faster, and when the rate of change slope is small, the corresponding braking force changes slower. Therefore, the embodiment of the present application can determine whether to trigger emergency braking by the rate of change slope. For example, when the rate of change slope is greater than a certain value, it means that the driver has stepped on the brake pedal urgently, and emergency braking is triggered.

[0076] For example, suppose that during the normal driving of the vehicle, a pedestrian or vehicle suddenly rushes out from the side, and the driver notices it in time and urgently steps on the brake pedal deeply. At this time, the slope of the braking force change is large, and it can be determined that the driver has the intention of emergency braking at this time. Therefore, it is necessary to appropriately increase the driver's requested braking force to ensure that the vehicle can be stopped in time. The embodiment of the present application can determine the correction value of the emergency braking force according to the slope of the rate of change, and the emergency braking force can be obtained by correcting the driver's requested braking force with the correction value to ensure that the vehicle can be stopped in time. Among them, the embodiment of the present application can obtain the corresponding relationship between the pre-calibrated rate of change slope and the correction value, and determine the correction value of the emergency braking force based on the corresponding relationship.

[0077] In an embodiment of the present application, when any caliper motor failure is identified, it also includes: obtaining the number and location of caliper motor failures; matching the target speed limit of the vehicle according to the number and / or location of caliper motor failures; and controlling the vehicle speed within the target speed limit.

[0078] It is understandable that the embodiments of the present application can limit the speed of the vehicle according to actual conditions when any caliper motor fails, so that the vehicle speed is within a safe range, thereby improving the safety of the vehicle.

[0079] Specifically, the number of failed caliper motors of the vehicle is identified. When any one caliper motor is identified as failed, the speed limit is any speed within the first speed range, such as 60kph; when any two caliper motors are identified as failed, the speed limit is any speed within the second speed range, such as 10kph, and the maximum value within the second speed range is less than the minimum value within the first speed range; when any three caliper motors are identified as failed, the vehicle will brake with the only remaining caliper motor or assist in braking to a stop through motor energy recovery, and cut off the power in time after stopping to improve the safety of the vehicle.

[0080] In the embodiment of the present application, after limiting the maximum speed of the vehicle within the target speed limit, it also includes: generating speed limit reminder information, and using the speed limit reminder information to remind the user of the speed limit.

[0081] It is understandable that the embodiments of the present application can generate a speed limit reminder to prompt the occupants of the vehicle to limit their speed, thereby ensuring the safety of the occupants of the vehicle and improving the user's car experience.

[0082] Specifically, the embodiments of the present application can display a corresponding speed limit reminder on the vehicle's display screen based on the actual condition of the caliper motor of each wheel of the vehicle, and / or voice broadcast the speed limit reminder, such as: "There is an abnormal braking situation, the speed must be limited to 60kph" or "There is an abnormal braking situation, please pull over" and other prompt messages, without specific limitation.

[0083] In step S103, the braking mechanism of each wheel is controlled to output a corresponding target braking force.

[0084] It can be understood that the embodiment of the present application controls the braking mechanism of each wheel to output the corresponding target braking force to achieve emergency braking of the vehicle. Through the independent control and adjustment of the braking force of each wheel, the stability during emergency braking is improved, and through wire control, the response speed can be improved.

[0085] In an embodiment of the present application, the braking mechanism of each wheel is controlled to output a corresponding target braking force, including: obtaining the current braking force of each wheel; and controlling the caliper motor in the corresponding braking mechanism to output a target current according to the current braking force of each wheel and the corresponding target braking force.

[0086] It can be understood that the embodiments of the present application can control the caliper motor in the corresponding brake mechanism to output the target current according to the current braking force of each wheel and the corresponding target braking force, wherein when the target braking force is greater than the current braking force, the target current is increased; when the target braking force is less than the current braking force, the target current is reduced.

[0087] In summary, the embodiments of the present application can calculate the target braking force of the corresponding wheel according to the slip rate of each wheel and the emergency braking force of the vehicle when the vehicle automatically triggers emergency braking or the driver actively triggers emergency braking, and control the braking mechanism of each wheel to output the corresponding target braking force to achieve emergency braking of the vehicle. Through independent control and adjustment of the braking force of each wheel, the stability during emergency braking is improved to avoid vehicle loss of control or sideslip.

[0088] Figure 2 It is a block diagram of an emergency braking device provided in an embodiment of the present application.

[0089] For example, Figure 2 As shown, the device 10 may include: an acquisition module 100 , a calculation module 200 and a control module 300 .

[0090] Among them, the acquisition module 100 is used to obtain the slip rate of each wheel of the vehicle during emergency braking; the calculation module 200 is used to calculate the target braking force of the corresponding wheel according to the slip rate of each wheel and the emergency braking force of the vehicle; the control module 300 is used to control the braking mechanism of each wheel to output the corresponding target braking force.

[0091] In the embodiment of the present application, the acquisition module 100 is further used to: acquire the actual wheel speed of each wheel; and calculate the slip rate of the corresponding wheel according to the actual wheel speed of each wheel.

[0092] In an embodiment of the present application, the calculation module 200 is further used to: obtain the driver's braking force and the slope of the rate of change of the driver's braking force; and calculate the corresponding emergency braking force according to the driver's braking force and the slope of the rate of change of the driver.

[0093] In the embodiment of the present application, the calculation module 200 is further used to: input the slip rate of each wheel and the emergency braking force of the vehicle into a closed-loop processing model, and the closed-loop processing model outputs the target braking force of the corresponding wheel.

[0094] In an embodiment of the present application, the calculation module 200 is further used to: identify whether there is a wheel with a failed caliper motor; when at least one caliper motor failure is identified, the slip rate of the wheel corresponding to the non-failed caliper motor and the emergency braking force of the vehicle are input into a closed-loop processing model, and the closed-loop processing model outputs the target braking force of each wheel corresponding to the non-failed caliper motor.

[0095] In an embodiment of the present application, a closed-loop processing model performs data processing using a closed-loop processing algorithm, wherein the closed-loop processing algorithm includes: if the slip rate of the wheel is less than or equal to a preset value, the emergency braking force is used as the target braking force of the corresponding wheel; if the slip rate of the wheel is greater than the preset value, when the actual yaw velocity of the vehicle is detected and the slip rate is not the longitudinal slip rate, the target braking force of the corresponding wheel is calculated based on the angular velocity difference between the actual yaw velocity and the target yaw velocity and the emergency braking force; otherwise, the target braking force of the corresponding wheel is calculated based on the longitudinal slip rate and the emergency braking force.

[0096] In an embodiment of the present application, the device 10 also includes: a speed limit module, used to obtain the number and location of caliper motor failures; match the target speed limit of the vehicle according to the number and / or location of caliper motor failures; and control the vehicle speed within the target speed limit.

[0097] In the embodiment of the present application, the control module 300 is further used to: obtain the current braking force of each wheel; and control the output target current of the caliper motor in the corresponding brake mechanism according to the current braking force of each wheel and the corresponding target braking force.

[0098] It should be noted that the above explanation of the emergency braking method embodiment is also applicable to the emergency braking device of this embodiment, and will not be repeated here.

[0099] In summary, the embodiments of the present application can obtain the slip rate of each wheel when the vehicle automatically triggers emergency braking or the driver actively triggers emergency braking based on the acquisition module, calculate the target braking force of the corresponding wheel based on the slip rate of each wheel and the emergency braking force of the vehicle based on the calculation module, and control the braking mechanism of each wheel to output the corresponding target braking force based on the control module to achieve emergency braking of the vehicle. Through independent control and adjustment of the braking force of each wheel, the stability during emergency braking is improved to avoid loss of control or sideslip of the vehicle.

[0100] Figure 3 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application. The vehicle may include:

[0101] A memory 301 , a processor 302 , and a computer program stored in the memory 301 and executable on the processor 302 .

[0102] When the processor 302 executes the program, the emergency braking method provided in the above embodiment is implemented.

[0103] Furthermore, the vehicle also includes:

[0104] The communication interface 303 is used for communication between the memory 301 and the processor 302 .

[0105] The memory 301 is used to store computer programs that can be run on the processor 302 .

[0106] The memory 301 may include a high-speed RAM (Random Access Memory) memory, and may also include a non-volatile memory, such as at least one disk memory.

[0107] If the memory 301, the processor 302 and the communication interface 303 are implemented independently, the communication interface 303, the memory 301 and the processor 302 can be connected to each other through a bus and communicate with each other. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 3 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0108] Optionally, in a specific implementation, if the memory 301, the processor 302 and the communication interface 303 are integrated on a chip, the memory 301, the processor 302 and the communication interface 303 can communicate with each other through an internal interface.

[0109] The processor 302 may be a CPU (Central Processing Unit), or an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present application.

[0110] An embodiment of the present application also provides a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, the emergency braking method as described above is implemented.

[0111] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0112] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0113] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An emergency braking method, in which a vehicle independently controls each wheel based on an electromechanical braking system, characterized in that: The method comprises: Obtain the slip rate of each wheel of the vehicle during emergency braking; Calculating a target braking force of a corresponding wheel according to the slip rate of each wheel and the emergency braking force of the vehicle; The braking mechanism of each wheel is controlled to output a corresponding target braking force.

2. The method according to claim 1, characterized in that The controlling the braking mechanism of each wheel to output a corresponding target braking force comprises: Obtaining the current braking force of each wheel; The output target current of the caliper motor in the corresponding brake mechanism is controlled according to the current braking force of each wheel and the corresponding target braking force.

3. The method according to claim 1, characterized in that The calculating the target braking force of the corresponding wheel according to the slip rate of each wheel and the emergency braking force of the vehicle includes: The slip rate of each wheel and the emergency braking force of the vehicle are input into a closed-loop processing model, and the closed-loop processing model outputs a target braking force of the corresponding wheel.

4. The method according to claim 1, characterized in that: The step of calculating the target braking force of the corresponding wheel according to the slip rate of each wheel and the emergency braking force of the vehicle further includes: Identifying whether a caliper motor of each wheel fails; When at least one caliper motor failure is identified, the slip rate of each wheel corresponding to the non-failed caliper motor and the emergency braking force of the vehicle are input into a closed-loop processing model, and the closed-loop processing model outputs the target braking force of each wheel corresponding to the non-failed caliper motor.

5. The method according to claim 3 or 4, characterized in that: The closed-loop processing model performs data processing using a closed-loop processing algorithm, wherein the closed-loop processing algorithm includes: If the slip rate of the wheel is less than or equal to a preset value, the emergency braking force is used as the target braking force of the corresponding wheel; If the slip rate of the wheel is greater than a preset value, then when the actual yaw velocity of the vehicle is detected and the slip rate is not the longitudinal slip rate, the target braking force of the corresponding wheel is calculated according to the angular velocity difference between the actual yaw velocity and the target yaw velocity and the emergency braking force; otherwise, the target braking force of the corresponding wheel is calculated according to the longitudinal slip rate and the emergency braking force.

6. The method according to claim 4, characterized in that When any caliper motor failure is detected, it also includes: Get the number and location of caliper motor failures; matching a target speed limit for the vehicle according to the number and / or location of caliper motor failures; The vehicle speed is controlled to be within the target speed limit.

7. The method according to claim 1, 3 or 4, characterized in that: Before calculating the target braking force of the corresponding wheel according to the slip rate of each wheel and the emergency braking force of the vehicle, the method further includes: Acquiring a driver's braking force and a slope of a rate of change of the driver's braking force; The corresponding emergency braking force is calculated according to the braking force of the driver and the slope of the rate of change of the driver.

8. The method according to claim 1, characterized in that The step of obtaining the slip rate of each wheel of the vehicle during braking also includes: Obtaining the actual wheel speed of each wheel; The slip ratio of each wheel is calculated according to the actual wheel speed.

9. A vehicle, characterized in that: The vehicle comprises: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the emergency braking method according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: A computer program is stored thereon, characterized in that the program is executed by a processor to implement the emergency braking method as described in any one of claims 1 to 8.

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