Reverse rotation control method and device in vehicle braking process, new energy vehicle and storage medium

Abstract

The invention discloses a reverse rotation control method and device in the vehicle braking process, a new energy vehicle and a storage medium, and relates to the technical field of new energy vehicles. The method comprises the steps that under the condition that an electric braking function of a vehicle is activated, vehicle braking is controlled based on electric braking target torque; in the vehicle braking process, if a preset anti-reverse-rotation triggering condition is met, the electric braking target torque is reset, the crawling dynamic torque and the hill-holding initial torque are determined based on the gradient of the current road surface, and the vehicle speed to the ground of the vehicle is controlled to return from a negative value to a zero value based on the crawling dynamic torque; acquiring a first vehicle speed change rate of the first braking stage, and correcting the slope-holding initial torque based on the first vehicle speed change rate to obtain a slope-holding target torque; and under the condition that the preset parking condition is met, a motor is controlled based on the slope parking target torque so as to control the vehicle to complete braking. By adopting the method, reverse rotation of the vehicle in the braking process can be avoided, so that the safety of the vehicle in the braking process is improved.

Description

Technical Field

[0001] The present application relates to the technical field of new energy vehicles, and in particular to a method and device for reverse control during vehicle braking, a new energy vehicle, and a storage medium. Background Art

[0002] New energy vehicle technology is constantly updated, and it is very necessary to improve the safety of new energy vehicles, especially the safety of the vehicle's parking process.

[0003] At present, the braking control of vehicles is mainly carried out by the driver operating the braking system. However, in the event of a failure of the braking system, in order to ensure that the vehicle has sufficient deceleration, the maximum recovery torque available from the motor is generally used as the electric braking target torque. In this way, the motor output torque determined based on the electric braking target torque may not be accurate enough, which may cause the vehicle to reverse and affect braking safety.

[0004] Therefore, how to improve the safety of the vehicle parking process has become an issue that needs to be solved urgently. Summary of the invention

[0005] The embodiments of the present application provide a method, device, new energy vehicle and storage medium for reverse control during vehicle braking, which can improve the safety of the vehicle parking process.

[0006] In a first aspect, an embodiment of the present application provides a reverse rotation control method during vehicle braking, the method comprising:

[0007] When an electric brake function of the vehicle is activated, controlling vehicle braking based on an electric brake target torque;

[0008] During the vehicle braking process, if the preset anti-reverse trigger condition is met, the electric brake target torque is cleared, the creep dynamic torque and the initial torque for holding the slope are determined based on the current slope of the road, and the vehicle's ground speed is controlled to return from a negative value to a value of 0 based on the creep dynamic torque;

[0009] The first vehicle speed change rate of the first braking stage is obtained, and the initial torque for holding the slope is corrected based on the first vehicle speed change rate to obtain the target torque for holding the slope; the first braking stage is a stage in which the vehicle's ground speed regresses from a negative value to a zero value;

[0010] When the preset parking conditions are met, the motor is controlled based on the hill-holding target torque to control the vehicle to complete braking.

[0011] In one embodiment, controlling vehicle braking based on an electric braking target torque includes: when the electric braking function of the vehicle is activated, determining the electric braking target torque based on the vehicle's ground speed and the slope of the road on which the vehicle is located, and controlling vehicle braking based on the electric braking target torque; obtaining a second vehicle speed change rate of the vehicle in a second braking stage; the vehicle speed in the second braking stage is greater than 0 and less than a preset vehicle speed threshold; when the absolute value of the second vehicle speed change rate is greater than the first change rate threshold, obtaining a first correction factor corresponding to the second vehicle speed change rate; the first correction factor is positively correlated with the second vehicle speed change rate, and the first correction factor is less than or equal to 1; based on the first correction factor, correcting the electric braking target torque, and continuing to control vehicle braking based on the corrected electric braking target torque.

[0012] In one of the embodiments, after continuing to control the vehicle braking based on the corrected electric braking target torque, the method also includes: obtaining a third vehicle speed change rate of the vehicle in a third braking stage; the third braking stage is after the second braking stage and before the first braking stage; when the absolute value of the third vehicle speed change rate is greater than the second change rate threshold, the current gear is a forward gear, and the motor speed is less than the preset motor speed threshold, determining that the preset anti-reverse trigger condition is met.

[0013] In one of the embodiments, the method further includes: when the absolute value of the third vehicle speed change rate is less than or equal to the second change rate threshold, using the corrected electric braking target torque as the hill-holding target torque.

[0014] In one embodiment, the hill-holding initial torque is corrected based on the first vehicle speed change rate to obtain the hill-holding target torque, including: determining a second correction factor corresponding to the first vehicle speed change rate based on a first corresponding relationship; the first corresponding relationship includes a corresponding relationship between multiple vehicle speed change rates and multiple correction factors, and the vehicle speed change rate is negatively correlated with the correction factor; the second correction factor is less than 1; and the hill-holding initial torque is corrected based on the second correction factor to obtain the hill-holding target torque.

[0015] In one embodiment, the creep dynamic torque is determined based on the slope of the current road surface, including: based on a second corresponding relationship, determining the creep dynamic torque corresponding to the vehicle's current ground speed and the current road surface slope; the second corresponding relationship includes a correspondence between multiple vehicle speed slope combinations and multiple dynamic torques, and the dynamic torque is positively correlated with the vehicle speed in the vehicle speed slope combination, and the dynamic torque is positively correlated with the slope in the vehicle speed slope combination.

[0016] In one of the embodiments, the slope is determined in the following manner: when the electric braking function is activated, the longitudinal acceleration collected by the vehicle's sensor is obtained, and based on the vehicle's current ground speed, the actual acceleration of the vehicle is derived; the difference between the longitudinal acceleration and the actual acceleration is obtained; based on the difference, the slope of the road surface on which the vehicle is located is determined by looking up a table.

[0017] In one embodiment, the method also includes: activating the electric braking function when at least one of the following conditions is met: a first condition that the key pressing duration for the target control of the vehicle is greater than a preset duration threshold; a second condition that the number of key pressings for the target control within a preset time period is greater than a preset number threshold; a third condition that the relative distance between the vehicle and the vehicle in front is less than a preset relative distance threshold, and the relative speed is greater than a preset relative speed threshold.

[0018] In a second aspect, an embodiment of the present application provides a reverse control device during vehicle braking, the device comprising:

[0019] a processing module, configured to control vehicle braking based on an electric brake target torque when an electric brake function of the vehicle is activated;

[0020] The processing module is further used for clearing the electric braking target torque if a preset anti-reverse trigger condition is met during the vehicle braking process, determining the creep dynamic torque and the initial torque for holding the slope based on the slope of the current road surface, and controlling the vehicle's ground speed to return from a negative value to a value of 0 based on the creep dynamic torque;

[0021] an acquisition and correction module, for acquiring a first vehicle speed change rate in a first braking phase, and correcting the initial torque for holding the slope based on the first vehicle speed change rate to obtain a target torque for holding the slope; the first braking phase is a phase in which the vehicle's ground speed regresses from a negative value to a zero value;

[0022] The control module is used to control the motor based on the hill-holding target torque to control the vehicle to complete braking when the preset parking conditions are met.

[0023] In a third aspect, an embodiment of the present application provides a new energy vehicle, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method of the first aspect when executing the computer program.

[0024] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the method described in the first aspect when the computer program is executed by a processor.

[0025] In a fifth aspect, the present application further provides a computer program product, including a computer program, which, when executed by a processor, implements the steps of the method described in the first aspect above.

[0026] The above-mentioned reverse control method, device, new energy vehicle and storage medium during vehicle braking, the new energy vehicle (hereinafter referred to as the vehicle) can control vehicle braking based on the electric braking target torque when the vehicle's electric braking function is activated; during the vehicle braking process, if the preset anti-reverse trigger condition is met, the electric braking target torque is cleared, the creep dynamic torque and the initial torque for holding the hill are determined based on the slope of the current road surface, and the vehicle's ground speed is controlled to regress from a negative value to a zero value based on the creep dynamic torque, and the first vehicle speed change rate of the braking stage is obtained, and the initial torque for holding the hill is corrected based on the first vehicle speed change rate to obtain the target torque for holding the hill; when the preset parking conditions are met, the motor is controlled based on the target torque for holding the hill to control the vehicle to complete braking. By adopting this method, when the electric braking function is activated, the vehicle can first control the vehicle braking based on the electric braking target torque. During the vehicle braking process, if the anti-reversal trigger condition is met, the creeping dynamic torque and the initial hill-holding torque are determined in real time based on the current road conditions. Based on the creeping dynamic torque, the vehicle is controlled to enter the creeping stage (i.e., the stage where the vehicle speed relative to the ground returns from a negative value to 0), and the vehicle speed change rate (first vehicle speed change rate) in the creeping stage (i.e., the first braking stage) is obtained. The initial hill-holding torque is corrected based on the vehicle speed change rate in the creeping stage. Since the creeping dynamic torque and the initial hill-holding torque are both determined in real time based on the road conditions when the vehicle may reverse, and the initial hill-holding torque is corrected based on the actual vehicle speed change rate in the creeping stage to obtain the target hill-holding torque, a more accurate target hill-holding torque can be obtained to prevent or alleviate the vehicle's braking reversal, thereby improving the safety of the vehicle during braking. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 This is a schematic diagram of an application scenario of a reverse control method during vehicle braking provided by an embodiment of the present application;

[0029] Figure 2 It is a flow chart of a reverse control method during vehicle braking provided by an embodiment of the present application;

[0030] Figure 3 It is a flow chart of another reverse control method during vehicle braking provided by an embodiment of the present application;

[0031] Figure 4It is a structural schematic diagram of a reverse control device during vehicle braking provided by an embodiment of the present application;

[0032] Figure 5 It is a structural schematic diagram of a new energy vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0034] First, the terms / nouns involved in the embodiments of the present application are briefly explained.

[0035] 1. Holding torque

[0036] Hill-holding torque refers to the motor torque when the vehicle is static, and the hill-holding torque can make the vehicle stationary on different slopes. The main function of the hill-holding torque is not to slow down the vehicle, but to maintain the vehicle's stillness. It is usually applied when the vehicle speed is low or even close to 0. In some cases, the hill-holding torque can be continuously increased from 0 to ensure that the vehicle remains as still as possible on uphill or downhill roads, thereby obtaining a suitable hill-holding torque. Among them, the motor torque can also be called the motor output torque, which is one of the basic parameters of the motor, commonly expressed in Nm (Newton-meter). The motor speed and output torque are usually inversely proportional. For example, at starting or low speed, the vehicle speed is low, the motor speed is low, and the motor output torque is high to provide sufficient driving force to overcome inertia and resistance; at high speed, the vehicle speed is high, the motor speed is high, and the output torque is low, which meets the cruising requirements and improves efficiency.

[0037] 2. Creep dynamic torque

[0038] Creep dynamic torque can also be called deceleration torque or braking torque. The main goal of creep dynamic torque is deceleration, and it can be dynamically adjusted according to the deceleration requirements. Creep dynamic torque can occur at various speeds of the vehicle and is not limited to use when stopped.

[0039] 3. Maximum available regenerative torque of the motor

[0040] The maximum available regenerative torque of the motor refers to the maximum value of the negative torque generated by the motor during energy recovery. When the driver releases the accelerator pedal or steps on the brake pedal, the motor control will generate a negative torque to slow down the car and achieve energy recovery. The value depends on factors such as the vehicle's control strategy, driving status, and the battery's energy storage capacity.

[0041] 4. D (Drive)

[0042] The D gear represents the vehicle's forward gear. Under normal circumstances, the motor should rotate forward at this time and the motor speed should be a positive value; if the motor rotates backward at this time, it indicates that the motor is reversed.

[0043] 5. Automobile 3D coordinate system

[0044] The three directions in the three-dimensional coordinate system of a car are: the lateral x direction refers to the left and right direction of the vehicle; the longitudinal y direction refers to the front and back direction of the vehicle; the up and down direction (vertical direction) of the vehicle is the z direction; among them, the synthesis of the lateral speed and the longitudinal speed is the speed of the vehicle.

[0045] 6. Vehicle speed change rate

[0046] In the present application, the vehicle speed change rate can be understood as the vehicle acceleration, which represents the change in the vehicle speed per unit time. In other words, the actually calculated vehicle speed change rate can be positive or negative. For example, during deceleration, the vehicle speed change rate is generally negative, and during acceleration, the vehicle speed change rate is generally positive. However, in the various embodiments of the present application, the descriptions related to the size of the vehicle speed change rate, including size comparison, size correlation description, etc., are all about discussing its absolute value. Correspondingly, the vehicle speed change rate thresholds are all positive values.

[0047] Optionally, the vehicle speed change rate can be determined by the vehicle controller calculating the vehicle speed at different times through the wheel speed or the vehicle's drive motor speed, which is not limited here.

[0048] Combine the following Figure 1 , introduces the application scenario of the reverse control method during vehicle braking provided by the embodiment of the present application. Figure 1 , Figure 1 Schematic diagram of an application scenario of a reverse control method during vehicle braking provided by an embodiment of the present application. Figure 1 As shown, the vehicle 100 includes a cockpit software system 101, an on-board interconnection terminal T-BOX (Telematics BOX) 102, a vehicle controller 103, a traditional braking system 104, a power battery system 105, a motor and a motor controller 106, etc. connected via a bus 107.

[0049] The cockpit software system 101 can be used to control the user interface in the car, including the instrument panel, touch screen, entertainment system and navigation system, and provide interactive functions for the driver and passengers.

[0050] As the vehicle's telematics unit, T-BOX 102 can connect the vehicle and the cloud through a communication network and is responsible for collecting, uploading and remotely controlling vehicle data.

[0051] The vehicle controller 103, as the brain of the new energy vehicle, is responsible for coordinating and controlling the operation of components such as batteries, motors, motor controllers, and thermal management systems, to achieve intelligent control of the vehicle's power distribution, energy management, and vehicle functions.

[0052] The conventional braking system 104, including the conventional brake system, mainly controls the deceleration and parking process of the vehicle by adjusting the clamping torque.

[0053] The power battery system 105 is mainly used to provide a main power source for the vehicle and to provide power for the motor when driving.

[0054] The motor and motor controller 106, where the motor is the core component that converts electrical energy into mechanical energy and provides power when the vehicle is driving, and the motor controller is responsible for controlling the speed and torque output of the motor. It receives instructions from the vehicle control system and adjusts the working state of the motor so that the motor can achieve the functions of acceleration, deceleration and braking. Specifically, the motor controller can change the working state of the motor by adjusting the current and voltage, and decide whether the motor drives the vehicle forward or recovers energy.

[0055] Among them, the motor and the motor controller 106 can also constitute an electric braking system. The electric braking system can be understood as adjusting the reverse torque of the motor through the motor controller to achieve vehicle deceleration or parking. In this process, the vehicle is braked by converting electrical energy into mechanical energy. The principles involved include energy recovery and braking control. Energy recovery can be understood as when the vehicle decelerates or stops, the motor controller controls the motor to generate reverse torque, converts the vehicle's kinetic energy into electrical energy, and stores it back in the battery, thereby extending the cruising range. This control method can reduce dependence on traditional mechanical brakes. Correspondingly, the electric braking process can be understood as the process of braking the vehicle mainly through the electric braking system.

[0056] For new energy vehicles, braking can be performed through traditional braking systems (including traditional brake systems, which mainly control the deceleration and parking of the vehicle by adjusting the clamping torque). When the traditional braking system fails, in order to ensure driving safety, the electric braking function can be activated, so that the vehicle can be parked by the motor. In the embodiment of the present application, the vehicle can first control the vehicle braking based on the electric braking target torque when the electric braking function is activated; during the vehicle braking process, if it is detected that the anti-reverse trigger condition is met, the vehicle is controlled to enter the creeping stage (i.e., the stage where the vehicle speed returns from a negative value to 0) based on the creeping dynamic torque, and the speed change rate of the creeping stage is obtained. The initial torque for holding the slope is corrected based on the speed change rate of the creeping stage to obtain the target torque for holding the slope, and the target torque for holding the slope is used to control the vehicle to hold the slope. Since both the creep dynamic torque and the hill-holding initial torque are determined in real time based on the road conditions when the vehicle may reverse, and the hill-holding initial torque is corrected based on the vehicle speed change rate in the creep stage, a more accurate hill-holding target torque can be obtained. Furthermore, in the process of controlling the motor based on the hill-holding target torque to control vehicle braking, the vehicle's braking reversal can be prevented or mitigated, thereby improving the safety of the vehicle during braking.

[0057] The reverse control method during vehicle braking provided in an embodiment of the present application is described below.

[0058] See also Figure 2 , Figure 2 1 is a flow chart of a reverse control method during vehicle braking provided by an embodiment of the present application. The method can be executed by a vehicle controller, or by a vehicle controller and a motor and a motor controller in collaboration, etc. For ease of explanation, the present application uses a vehicle controller (e.g. Figure 1 The vehicle controller 103 in the vehicle 100 shown in the figure performs a reverse control method during vehicle braking as an example. Figure 2 As shown, the reverse control method during the vehicle braking process may include but is not limited to the following steps:

[0059] S201 : When the electric brake function of the vehicle is activated, control vehicle braking based on the electric brake target torque.

[0060] Among them, the electric braking function and the activation conditions of the electric braking function can be pre-configured in the vehicle in the present application. The electric braking function can be understood as a function of controlling vehicle braking based on the above-mentioned electric braking system. When this function is activated, it can replace the traditional braking system to achieve vehicle deceleration and parking. The activation conditions of the electric braking function can include one or more conditions.

[0061] Among them, the motor under the electric braking function is the same motor as the motor during normal driving of the vehicle. It can be understood that the electric braking function and the vehicle driving function are two working modes of the motor. The motor can switch to the electric braking function mode, or exit the electric braking function mode and switch to the vehicle driving function mode based on the preset activation conditions and return conditions of the electric braking function.

[0062] The electric brake target torque may be understood as the motor torque used to decelerate the vehicle when the electric brake function of the vehicle is activated.

[0063] In an optional embodiment, during vehicle driving, the vehicle controller can obtain multiple status information of the vehicle in real time or periodically, and determine whether the activation conditions of the electric braking function are met based on one or more of the multiple status information; if it is determined that the activation conditions are met, the aforementioned electric braking function can be activated, the electric braking target torque can be determined, and the vehicle braking can be controlled based on the electric braking target torque.

[0064] For example, during the driving process of the vehicle, the vehicle controller can obtain multiple status information of the vehicle in real time, and match the multiple status information with the activation conditions of the electric brake function to determine whether the activation conditions of the electric brake function are met. When the vehicle controller determines that the activation conditions of the electric brake function are met, it can activate the electric brake function, determine the electric brake target torque, and control the vehicle braking based on the electric brake target torque.

[0065] Optionally, the electric braking target torque can be determined by the vehicle controller based on the vehicle's current speed and the slope of the road on which the vehicle is located by table lookup, or it can be obtained by the vehicle controller inputting the vehicle's current speed and the slope of the road on which the vehicle is located into a pre-built electric braking target torque determination model, etc., which is not limited here.

[0066] Optionally, the vehicle controller controls vehicle braking based on the electric braking target torque, and may adjust the motor output torque based on the electric braking target torque to control vehicle braking.

[0067] S202. During vehicle braking, if the preset anti-reverse trigger condition is met, the electric braking target torque is cleared, the creep dynamic torque and the initial torque for holding the slope are determined based on the current slope of the road surface, and the vehicle's ground speed is controlled to return from a negative value to a value of 0 based on the creep dynamic torque.

[0068] Among them, the preset anti-reverse trigger condition can be determined based on the historical parking state information of the vehicle. In an optional embodiment, during the driving process of the vehicle, the vehicle controller can obtain multiple state information of the vehicle in real time or periodically, and determine whether the preset anti-reverse trigger condition is met based on one or more of the multiple state information. Exemplarily, the vehicle controller can determine that the preset anti-reverse trigger condition is met when it is determined that at least one of the following conditions is met: the absolute value of the vehicle speed change rate during the deceleration stage is greater than the preset vehicle speed change rate threshold (for example, 2m / s 2 ), the motor speed in D gear is less than the preset motor speed threshold (for example, -200rpm).

[0069] In an optional embodiment, during vehicle braking, the vehicle controller can obtain multiple status information of the vehicle in real time or periodically, and determine whether the preset anti-reverse trigger condition is met based on one or more of the multiple status information. If it is determined that the preset anti-reverse trigger condition is met, the electric braking target torque can be cleared, and the creep dynamic torque and the initial torque for holding on the hill can be determined based on the current road slope, and converted to control the vehicle's ground speed based on the creep dynamic torque from a negative value to a zero value.

[0070] In an optional implementation, the vehicle controller determines the creep dynamic torque based on the slope of the current road surface, which can be determined by looking up a table based on the slope of the current road surface and the current vehicle speed relative to the ground. The table includes a correspondence between multiple vehicle speed gradient combinations and multiple creep dynamic torques. Optionally, the table can be a table preset in the vehicle controller, or a table preset in a database and readable by the vehicle controller, etc., which is not limited here.

[0071] S203, obtaining a first vehicle speed change rate in a first braking phase, and correcting the initial hill-holding torque based on the first vehicle speed change rate to obtain a hill-holding target torque; the first braking phase is a phase in which the vehicle's ground speed regresses from a negative value to a zero value.

[0072] Among them, since the first braking stage is the stage where the vehicle's ground speed regresses from a negative value to a zero value, and the vehicle's ground speed regresses from a negative value to a zero value is controlled by the vehicle controller based on the creep dynamic torque, the first braking stage can also be called the creep stage, and the first vehicle speed change rate of the first braking stage can also be called the vehicle speed change rate of the creep stage.

[0073] The first vehicle speed change rate is a physical quantity used to characterize the change in vehicle speed during the stage when the vehicle's ground speed regresses from a negative value to a zero value.

[0074] S204: When the preset parking condition is met, the motor is controlled based on the hill-parking target torque to control the vehicle to complete braking.

[0075] Among them, the preset parking condition can be one condition or multiple conditions, and the parking condition can be determined based on the historical parking information of the vehicle. In an optional embodiment, during the driving process of the vehicle, the vehicle controller can obtain multiple status information of the vehicle in real time or periodically, and determine whether the preset parking condition is met based on one or more of the multiple status information. Exemplarily, the vehicle controller can determine the preset parking condition based on the vehicle speed and throttle opening. For example, if it is determined that the following conditions are met, it is determined that the preset parking condition is met: the absolute value of the current ground speed is less than the preset vehicle speed threshold (for example, 5km / h).

[0076] In an optional implementation, the vehicle controller may control the motor controller in the vehicle to adjust the motor output torque to gradually switch to the hill-holding target torque until the vehicle completes parking.

[0077] In an embodiment of the present application, the vehicle controller can control the vehicle braking based on the electric braking target torque when the vehicle's electric braking function is activated; during the vehicle braking process, if the preset anti-reverse trigger condition is met, the electric braking target torque is cleared, the creep dynamic torque and the hill-holding initial torque are determined based on the current slope of the road surface, and the vehicle's ground speed is controlled to regress from a negative value to a zero value based on the creep dynamic torque, and the first vehicle speed change rate of the first braking stage is obtained, and the hill-holding initial torque is corrected based on the first vehicle speed change rate to obtain the hill-holding target torque; when the preset parking conditions are met, the motor is controlled based on the hill-holding target torque to control the vehicle to complete braking. By adopting this method, when the electric braking function is activated, the vehicle can first control the vehicle braking based on the electric braking target torque. During the vehicle braking process, if the anti-reversal trigger condition is met, the creeping dynamic torque and the initial hill-holding torque are determined in real time based on the current road conditions. The vehicle is controlled to enter the creeping stage (i.e., the stage where the vehicle speed returns from a negative value to 0) based on the creeping dynamic torque, and the vehicle speed change rate (first vehicle speed change rate) in the creeping stage (i.e., the first braking stage) is obtained. The initial hill-holding torque is corrected based on the vehicle speed change rate in the creeping stage. Since the creeping dynamic torque and the initial hill-holding torque are both determined in real time based on the road conditions when the vehicle may reverse, and the initial hill-holding torque is also corrected based on the vehicle speed change rate in the creeping stage, a more accurate hill-holding target torque can be obtained to prevent or alleviate the vehicle's braking reversal, thereby improving the safety of the vehicle during braking.

[0078] In an optional embodiment, Figure 2In the reverse control method during vehicle braking shown, the vehicle controller controls vehicle braking based on the electric braking target torque, which may include: when the vehicle's electric braking function is activated, determining the electric braking target torque based on the vehicle's ground speed and the slope of the road on which the vehicle is located, and controlling the vehicle braking based on the electric braking target torque; obtaining the second vehicle speed change rate of the vehicle in the second braking stage; the vehicle speed in the second braking stage is greater than 0 and less than a preset vehicle speed threshold; when the absolute value of the second vehicle speed change rate is greater than the first change rate threshold, obtaining a first correction factor corresponding to the second vehicle speed change rate; the first correction factor is positively correlated with the second vehicle speed change rate, and the first correction factor is less than or equal to 1; based on the first correction factor, correcting the electric braking target torque, and continuing to control the vehicle braking based on the corrected electric braking target torque.

[0079] In some embodiments, the slope can be determined by the vehicle controller in the following manner: when the electric braking function is activated, the longitudinal acceleration collected by the vehicle's sensor is obtained, and based on the vehicle's current ground speed, the actual acceleration of the vehicle is derived; the difference between the longitudinal acceleration and the actual acceleration is determined; based on the difference, the slope of the road surface on which the vehicle is located is determined by looking up the table.

[0080] The accuracy of the sensor's measurement of longitudinal acceleration may be related to its posture. For example, when the vehicle is on a slope, the sensor installed on the vehicle may be in a non-horizontal state, and the longitudinal acceleration measured by the sensor may not be accurate enough. Therefore, there may be a certain deviation between the longitudinal acceleration and the actual acceleration calculated based on the vehicle's ground speed. Therefore, based on the difference between the two, the current slope of the vehicle can be reversely inferred.

[0081] Optionally, the vehicle controller may pre-establish a correspondence table (referred to as correspondence table 1) based on multiple sets of difference data (differences between longitudinal acceleration and actual acceleration) and slopes input by the user, wherein the correspondence table 1 includes correspondences between multiple sets of difference data and slopes. Exemplarily, the correspondence table 1 may be as shown in Table 1 below.

[0082] Table 1 Corresponding relationship Table 1

[0083]

[0084] Among them, a positive slope indicates an uphill slope, and a negative slope indicates a downhill slope. It can be seen from Table 1 above that the greater the absolute value of the difference between the longitudinal acceleration and the actual acceleration, the greater the current road slope; the smaller the absolute value of the difference between the longitudinal acceleration and the actual acceleration, the smaller the current road slope. By looking up the table, the current road slope of the vehicle can be determined simply and efficiently.

[0085] Optionally, since both the longitudinal acceleration and the actual acceleration can be detected or calculated in real time, the vehicle controller can determine the corresponding slope in real time based on the latest determined longitudinal acceleration and actual acceleration, and use the latest determined slope to update the previously determined slope to ensure that the recorded slope better matches the actual situation.

[0086] In some embodiments, when the electric braking function of the vehicle is activated, the vehicle controller determines the electric braking target torque based on the vehicle's ground speed and the slope of the road on which the vehicle is located. The electric braking target torque can be obtained by looking up a table based on the vehicle's current ground speed and the slope of the road on which the vehicle is located.

[0087] Optionally, the vehicle controller may pre-establish a correspondence table (referred to as correspondence table 2) based on the vehicle speed and slope input by the user, wherein the correspondence table 2 includes a plurality of correspondences between vehicle speed and slope. Exemplarily, the sixth correspondence table may be shown in Table 2 below.

[0088] Table 2 Corresponding relationship Table 2

[0089]

[0090] Among them, a positive slope indicates an uphill slope, and a negative slope indicates a downhill slope. As can be seen from Table 2, when the vehicle is in the deceleration stage (the ground speed is greater than 0), since the vehicle has less resistance when traveling downhill than when traveling uphill, if the ground speed remains unchanged, the greater the absolute value of the electric brake initial torque required for the vehicle to travel downhill relative to that of traveling uphill; when the vehicle is stationary (i.e., the ground speed is 0), the greater the slope, the greater the absolute value of the required electric brake initial torque. By looking up the table, the electric brake target torque corresponding to the activation of the vehicle's electric brake function can be determined simply and efficiently.

[0091] Among them, after the vehicle controller determines the electric braking target torque based on the vehicle's ground speed and the slope of the road on which the vehicle is located, it can control the vehicle braking based on the electric braking target torque; thereafter, the second vehicle speed change rate in the second braking stage (that is, the vehicle speed change rate in the process of controlling the vehicle braking based on the electric braking target torque) can be obtained.

[0092] In some embodiments, the vehicle controller may obtain a first correction factor corresponding to the second vehicle speed change rate when the absolute value of the second vehicle speed change rate is greater than the first change rate threshold. The first change rate threshold may also be referred to as the first vehicle speed change rate threshold. For example, assuming that the first change rate threshold is 1 m / s 2 , the second vehicle speed change rate is -1.1m / s 2 In this case, the vehicle controller can determine the absolute value of the second vehicle speed change rate as 1.1m / s 2Greater than the first change rate threshold 1m / s 2 At this time, the vehicle controller can obtain the first correction factor corresponding to the second vehicle speed change rate.

[0093] Optionally, the vehicle controller obtains the first correction factor corresponding to the second vehicle speed change rate, which may be obtained by looking up a table (recorded as correspondence table 3) based on the second vehicle speed change rate. Optionally, correspondence table 3 may be a table preset in the vehicle controller, or a table preset in a database and readable by the vehicle controller, etc., which is not limited here. Among them, correspondence table 3 includes the correspondence between multiple vehicle speed change rates and multiple correction factors; the second vehicle speed change rate is positively correlated with the correction factor. Exemplarily, correspondence table 3 may be shown in Table 3 below.

[0094] Table 3 Corresponding relationship Table 3

[0095]

[0096] Among them, in the deceleration stage, the greater the absolute value of the vehicle speed change rate, the greater the degree of reversal, therefore, the greater the required braking torque, and the smaller the correction factor for correcting the electric brake target torque. It can be seen from Table 3 that the greater the vehicle speed change rate, the greater the correction factor for correcting the electric brake target torque.

[0097] In some embodiments, the vehicle controller corrects the electric braking target torque based on the first correction factor, and the product of the first correction factor and the electric braking target torque may be used as the corrected electric braking target torque.

[0098] By adopting this implementation mode, the vehicle controller can determine the electric braking target torque based on the vehicle's ground speed and the slope of the road surface on which the vehicle is located when the vehicle's electric braking function is activated, and control the vehicle braking based on the electric braking target torque, and obtain a second vehicle speed change rate during the braking process, and correct the electric braking target torque based on a first correction factor corresponding to the second vehicle speed change rate to obtain a corrected electric braking target torque. In this way, by correcting the electric braking target torque based on the vehicle speed change rate for controlling the vehicle braking based on the electric braking target torque, a torque that better meets the braking requirements can be accurately determined (i.e., the accuracy of the determined corrected electric braking target torque is higher), thereby reducing the possibility of reversal during vehicle braking.

[0099] In an optional embodiment, after the vehicle controller continues to control the vehicle braking based on the corrected electric braking target torque, it can also obtain the third vehicle speed change rate of the vehicle in the third braking stage; the third braking stage is after the second braking stage and before the first braking stage; when the absolute value of the third vehicle speed change rate is greater than the second change rate threshold, the current gear is a forward gear, and the motor speed is less than the preset motor speed threshold, it is determined that the preset anti-reverse trigger condition is met.

[0100] The third braking stage refers to a stage of continuing to control vehicle braking based on the corrected electric braking target torque.

[0101] For example, assuming that the second change rate threshold is 1.1 m / s 2 , the preset motor speed threshold in D gear is -200rpm, and the third vehicle speed change rate is assumed to be -1.3m / s 2 , the current gear is D gear, the motor speed is -300rpm, in this case, the vehicle controller can determine the absolute value of the third vehicle speed change rate is 1.3m / s 2 Greater than the second change rate threshold 1.1m / s 2 , the current gear is D gear, and the motor speed -300rpm is less than the preset motor speed threshold -200rpm. At this time, the vehicle controller can determine that the preset anti-reverse trigger condition is met.

[0102] Optionally, the vehicle controller may also use the corrected electric braking target torque as the hill-holding target torque when the absolute value of the third vehicle speed change rate is less than or equal to the second change rate threshold.

[0103] For example, assuming that the second change rate threshold is 1.1 m / s 2 , and assume that the third vehicle speed change rate is -0.5m / s 2 In this case, the vehicle controller can determine the absolute value of the third vehicle speed change rate as 0.5m / s 2 Less than the second change rate threshold 1.1m / s 2 At this time, the vehicle controller can use the corrected electric braking target torque as the hill-holding target torque.

[0104] By adopting this implementation mode, the vehicle controller can continue to control the vehicle braking based on the corrected electric braking target torque, and then determine whether the preset anti-reversal trigger condition is met by the vehicle speed change rate when continuing to control the vehicle braking based on the corrected electric braking target torque. This is conducive to timely executing the relevant anti-reversal operation when it is determined that the anti-reversal trigger condition is met, thereby avoiding reversal of the vehicle.

[0105] In an optional embodiment, Figure 2In the reverse control method during vehicle braking shown, the vehicle controller corrects the initial torque for holding the hill based on the first vehicle speed change rate to obtain the target torque for holding the hill, which may include: determining a second correction factor corresponding to the first vehicle speed change rate based on a first corresponding relationship; the first corresponding relationship includes a corresponding relationship between multiple vehicle speed change rates and multiple correction factors; the vehicle speed change rate is negatively correlated with the correction factor; the second correction factor is less than 1; and correcting the initial torque for holding the hill based on the second correction factor to obtain the target torque for holding the hill.

[0106] Optionally, the first correspondence may be a table preset in the vehicle controller (referred to as the first correspondence table), or a table preset in a database and readable by the vehicle controller (referred to as the first correspondence table), etc., which is not limited here. The first correspondence table includes the correspondence between multiple vehicle speed change rates and multiple correction factors; the vehicle speed change rate is negatively correlated with the correction factor. Exemplarily, the first correspondence table may be shown in Table 4 below.

[0107] Table 4 The first correspondence table

[0108]

[0109] As shown in Table 4 above, the smaller the speed change rate in the creeping stage, the larger the corresponding correction factor for correcting the initial torque of the hill-holding vehicle. By looking up the table, the correction factor for correcting the initial torque of the hill-holding vehicle can be quickly determined, which is beneficial to improving the efficiency of vehicle braking.

[0110] In some embodiments, the vehicle controller corrects the initial hill-holding torque based on the second correction factor to obtain the hill-holding target torque, and the product of the second correction factor and the initial hill-holding torque is used as the hill-holding target torque.

[0111] By adopting this implementation mode, the initial hill-holding torque is corrected by utilizing the vehicle speed change rate in the creeping phase of the vehicle, so that the accuracy of the determined hill-holding target torque can be improved. Thus, in the subsequent process of controlling the vehicle motor based on the more accurate hill-holding target torque to control the vehicle braking, the vehicle reversal can be avoided, thereby improving the safety of the vehicle during braking.

[0112] In an optional embodiment, the vehicle controller determines the creep dynamic torque based on the slope of the current road surface, which may include: determining the creep dynamic torque corresponding to the vehicle's current ground speed and the current road surface slope based on a second corresponding relationship; the second corresponding relationship includes a correspondence between multiple speed gradient combinations and multiple dynamic torques, wherein the vehicle speed refers to the ground speed; the dynamic torque is positively correlated with the vehicle speed in the speed gradient combination, and the dynamic torque is positively correlated with the slope in the speed gradient combination.

[0113] Optionally, the second correspondence may be a table preset in the vehicle controller (referred to as the second correspondence table), or a table preset in a database and readable by the vehicle controller (referred to as the second correspondence table), etc., which is not limited here. Among them, the second correspondence table includes the correspondence between multiple vehicle speed gradient combinations and multiple dynamic torques, wherein the vehicle speed refers to the vehicle speed relative to the ground; the dynamic torque is positively correlated with the vehicle speed in the vehicle speed gradient combination, and the dynamic torque is positively correlated with the gradient in the vehicle speed gradient combination. Exemplarily, the second correspondence table may be shown in Table 5 below.

[0114] Table 5 Second correspondence table

[0115]

[0116] Among them, a positive slope indicates an uphill slope, and a negative slope indicates a downhill slope. It can be seen from Table 5 that when the vehicle is in the creeping stage (the ground speed is less than 0), since the vehicle has less resistance when traveling downhill than when traveling uphill, if the ground speed remains unchanged, the greater the absolute value of the creeping dynamic torque required for the vehicle to travel downhill than when traveling uphill; when the vehicle is stationary (i.e., the ground speed is 0), the greater the slope, the greater the absolute value of the creeping dynamic torque required. With this implementation, the creeping dynamic torque can be quickly determined by looking up the table.

[0117] In an optional embodiment, Figure 2 In the reverse control method during vehicle braking, the vehicle controller may also activate the electric braking function when at least one of the following conditions is met:

[0118] (1) A first condition that the duration of pressing a target control of the vehicle is greater than a preset duration threshold;

[0119] (2) A second condition that the number of key presses on the target control within a preset time period is greater than a preset key press threshold;

[0120] (3) A third condition that the relative distance between the vehicle and the preceding vehicle is less than a preset relative distance threshold, and the relative speed is greater than a preset relative speed threshold.

[0121] The target control may be a physical button or a virtual button inside the vehicle, and the association between the target button and the electric brake function is predefined. The target button may be a dedicated button for activating or deactivating the electric brake function, or may be a button that realizes other functions and is configured to activate or deactivate the electric brake function under specific operating conditions.

[0122] That is to say, the vehicle controller can activate the electric braking function when at least one of the first condition, the second condition, and the third condition is met.

[0123] For example, assuming that the preset duration threshold corresponding to the target control is 1s, and the driver presses the target control for 2s, the vehicle controller can determine that the pressing duration of 2s for the target control exceeds the preset duration threshold of 1s. In this case, it can be determined that there is an intention to decelerate. At this time, the vehicle controller can activate the electric braking function.

[0124] For another example, assuming that the duration of the preset time period is 1s, the preset key count threshold for the target control within 1s is 2 times, and the driver presses the target control 3 times within 1s, the vehicle controller can determine that the number of key presses for the target control 3 times within 1s is greater than the preset key count threshold of 2 times. In this case, it can be determined that there is an intention to decelerate, and the vehicle controller can activate the electric braking function.

[0125] For another example, assuming that the preset relative distance threshold is 20m, the preset relative speed threshold is 50km / h, and assuming that the relative distance between the vehicle and the vehicle in front is 18m, and the relative speed is 55km / h, the vehicle controller can determine that the relative distance between the vehicle and the vehicle in front is 18m less than the preset relative distance threshold of 20m, and the relative speed of 55km / h is greater than the preset relative speed threshold of 50km / h. In this case, it can be determined that there is a risk of collision. At this time, the vehicle controller can activate the electric braking function.

[0126] Optionally, the vehicle controller may also exit the electric braking function when it determines that at least one of the following conditions is met: (1) the accelerator pedal opening is greater than a preset proportional value; (2) the relative distance between the vehicle and the vehicle in front is greater than a preset distance threshold and the relative speed is less than the preset distance threshold.

[0127] For example, assuming that the accelerator opening is 30% and the preset ratio value is 20%, the vehicle controller can determine that the accelerator opening of 30% is greater than the preset ratio value of 20%. In this case, it can be determined that there is an acceleration intention. At this time, the vehicle controller can exit the electric braking function.

[0128] For another example, assuming that the preset relative distance threshold is 30m, the preset relative speed threshold is 20km / h, and assuming that the relative distance between the vehicle and the vehicle in front is 31m, and the relative speed is 8km / h, the vehicle controller can determine that the relative distance 31m between the vehicle and the vehicle in front is greater than the preset relative distance threshold 30m, and the relative speed 8km / h is less than the preset relative speed threshold 10km / h. In this case, it can be determined that there is no collision risk. At this time, the vehicle controller can exit the electric braking function.

[0129] By adopting this implementation mode, the vehicle controller can determine under what circumstances to activate the electric braking function, so that when the triggering conditions for activating the electric braking function are detected, the electric braking function can be activated in time, which is conducive to timely control of vehicle braking.

[0130] Combine the following Figure 3 , the overall process of the reverse control method during vehicle braking provided by the embodiment of the present application is described. Figure 3 , Figure 3 FIG. 1 is a flow chart of another method for controlling the reverse rotation of a vehicle during braking provided by an embodiment of the present application, which method can be executed by a vehicle controller. Figure 3 As shown, the reverse control method during vehicle braking may include but is not limited to the following steps.

[0131] S301, monitor the motor speed, button status, gear position, longitudinal acceleration, and throttle opening of the vehicle in real time.

[0132] S302: Calculate the current vehicle speed based on the motor speed.

[0133] In an optional implementation, the vehicle controller may use the following formula when calculating the vehicle speed based on the motor speed.

[0134]

[0135] In formula (1), V represents the vehicle speed (unit: km / h); n represents the motor speed (unit: rpm); r represents the tire radius (unit: meter); i represents the speed ratio; and μ is the conversion coefficient from speed to vehicle speed.

[0136] Based on the vehicle speed and the current driving direction of the vehicle, the ground speed can be obtained. The driving direction can be forward or reverse; the forward direction is the direction the front of the vehicle is facing. In some possible embodiments, the driving direction of the vehicle can be determined by the positive and negative of the motor speed, that is, forward and reverse. For example, a positive motor speed can correspond to a forward driving direction, and a negative motor speed can correspond to a reverse driving direction. For example, V Direction Indicates the vehicle's driving direction. When the motor speed is less than -50rpm, the driving direction is reverse, then V Direction Equal to -1, when the motor speed is greater than 50rpm, the driving direction is forward, V Direction Equal to 1. Of course, the motor speed threshold here can also take other values. In order to ensure the accuracy of the judgment, the threshold is generally not close to 0.

[0137] S303: Determine the slope of the road on which the vehicle is located based on the longitudinal acceleration and the vehicle speed relative to the ground.

[0138] In an optional embodiment, the vehicle controller calculates the slope based on the longitudinal acceleration and the vehicle speed relative to the ground, which may include: taking the derivative of the vehicle speed relative to the ground to obtain the actual acceleration of the vehicle; determining the difference between the longitudinal acceleration and the actual acceleration; and determining the slope of the road surface on which the vehicle is located by looking up a table based on the difference.

[0139] Optionally, the specific description of this implementation mode can be found in the above description of the method for determining the slope, which will not be repeated here.

[0140] S304: Determine the electric brake function flag based on the button status, throttle opening, relative distance, and relative speed.

[0141] Exemplarily, the vehicle controller may also activate the electric braking function when at least one of the following conditions is met: (1) the duration of pressing the target control exceeds a preset duration threshold of 1 second; (2) the number of key presses on the target control within a preset time period (1 second) exceeds a preset key press threshold of 2; (3) the relative distance between the vehicle and the vehicle in front is less than a preset relative distance threshold of 20 meters and the relative speed is greater than a preset relative speed threshold of 50 km / h.

[0142] For example, the vehicle controller may also exit the electric braking function when at least one of the following conditions is met: (1) the accelerator pedal opening is greater than 20%; (2) the relative distance between the vehicle and the vehicle in front is greater than a preset relative distance threshold of 30m and the relative speed is less than a preset relative speed threshold of 20km / h.

[0143] S305: Determine the electric braking target torque based on the electric braking function flag, the vehicle speed relative to the ground, the slope, and the maximum regenerative torque available for the motor.

[0144] Optionally, when the electric brake function flag is activated, the vehicle controller can determine the initial target torque of the electric brake by looking up a table (such as Table 2 above) with the vehicle speed relative to the ground as the horizontal coordinate and the slope as the vertical coordinate. The higher the vehicle speed relative to the ground and the smaller the slope, the greater the determined target torque of the electric brake. The target torque of the electric brake needs to be within the maximum recovery torque range available to the motor.

[0145] When the vehicle speed is close to 0, in order to ensure that the vehicle can remain stationary on different slopes, the electric brake target torque needs to be set within an appropriate range.

[0146] S306 , controlling vehicle braking based on the electric brake target torque, and determining a corrected electric brake target torque based on the vehicle speed change rate and the electric brake target torque during the braking process.

[0147] For example, the vehicle controller can determine the degree of reversal based on the vehicle speed change rate. When the vehicle speed is less than the set threshold value of 0.5 km / h, the vehicle speed change rate is used as the horizontal coordinate to look up the table (such as the above Table 3) to determine the first correction factor for correcting the electric brake target torque. If the vehicle speed change rate is greater, it means that the degree of reversal is greater, and the electric brake target torque needs to be corrected. Among them, the corrected electric brake target torque can be the product of the electric brake target torque and the first correction factor.

[0148] S307 : Continue to control vehicle braking based on the corrected electric brake target torque.

[0149] Optionally, after the vehicle controller continues to control the vehicle braking based on the corrected electric brake target torque, if the vehicle speed change rate is low enough, the torque can stop the vehicle, and the corrected electric brake target torque can be used as the hill-holding target torque. If the vehicle speed change rate is still too large, the vehicle will continue to move in the opposite direction, and the correction factor will continue to take effect before the anti-reverse flag is triggered. In other words, if the vehicle speed change rate is still too large and the anti-reverse flag is not triggered, the vehicle controller can correct the corrected electric brake target torque again based on the correction factor corresponding to the vehicle speed change rate during the braking phase.

[0150] S308: Determine the anti-reverse flag position based on the motor speed and gear position.

[0151] Exemplarily, the vehicle controller can perform anti-reverse protection under the following conditions when the absolute value of the vehicle speed change rate during the braking phase of the vehicle is continued to be controlled based on the corrected electric brake target torque is greater than the preset change rate threshold: when the gear is in D gear, the motor speed is less than the set threshold -200rpm. In other words, the vehicle controller can activate the anti-reverse flag when the absolute value of the vehicle speed change rate during the braking phase of the vehicle is continued to be controlled based on the corrected electric brake target torque is greater than the preset change rate threshold, and when the gear is in D gear, the motor speed is less than the set threshold -200rpm.

[0152] S309: Calculate the creep dynamic torque and the hill-holding initial torque based on the anti-reverse flag, the vehicle speed change rate, and the vehicle speed, and control the vehicle's ground speed to return from a negative value to a zero value based on the creep dynamic torque.

[0153] The basic principle is as follows:

[0154] When the anti-reverse flag is activated, it means that the vehicle is moving in the opposite direction too much, and the corrected electric brake target torque must be cleared immediately, and in order to avoid the vehicle from losing control, the creep dynamic torque must be calculated based on the current slope. Optionally, the vehicle controller can calculate the creep dynamic torque by looking up a table (such as Table 5) with the vehicle speed as the horizontal coordinate and the slope as the vertical coordinate. Among them, the lower the ground speed and the smaller the slope, the smaller the creep torque dynamic torque determined.

[0155] Optionally, the initial torque for holding the hill can be determined by the vehicle controller through table lookup based on the vehicle speed and slope, or it can be obtained by the vehicle controller inputting the vehicle speed and slope into a pre-built initial torque for holding the hill determination model, which is not limited here.

[0156] S310, correcting the hill-holding initial torque based on a correction factor corresponding to the vehicle speed change rate in the creep phase to obtain a hill-holding target torque.

[0157] Optionally, the vehicle controller may determine a correction factor corresponding to the vehicle speed change rate in the creeping phase by looking up a table (such as Table 4 above) based on the vehicle speed change rate in the creeping phase.

[0158] Optionally, the vehicle controller corrects the initial torque for holding the hill based on the correction factor corresponding to the vehicle speed change rate in the creep phase to obtain the target torque for holding the hill, and the product of the correction factor corresponding to the vehicle speed change rate in the creep phase and the initial torque for holding the hill can be used as the target torque for holding the hill.

[0159] S311. When the preset parking condition is met, the motor is controlled based on the hill-holding target torque to control the vehicle to complete braking.

[0160] In an embodiment of the present application, the vehicle controller can determine the activation flag of the electric braking function based on the button status, throttle opening, relative distance, and relative speed; determine the electric braking target torque based on the electric braking function flag, the vehicle speed to the ground, the slope, and the maximum recovery torque available from the motor; control the vehicle braking based on the electric braking target torque, and during the braking process, determine the corrected electric braking target torque based on the vehicle speed change rate and the electric braking target torque; continue to control the vehicle braking based on the corrected electric braking target torque; determine the anti-reverse flag based on the motor speed and gear position; calculate the creeping dynamic torque and the initial torque for holding the hill based on the anti-reverse flag, the vehicle speed change rate, and the vehicle speed, and control the vehicle's ground speed to regress from a negative value to a zero value based on the creeping dynamic torque; correct the initial torque for holding the hill based on the correction factor corresponding to the vehicle speed change rate in the creeping stage to obtain the target torque for holding the hill; finally, when the preset parking conditions are met, control the motor based on the target torque for holding the hill until the vehicle completes parking. In this way, the vehicle controller can control the vehicle braking based on the electric braking target torque when the electric braking function is activated. If the anti-reversal trigger condition is met during the vehicle braking process, the creeping dynamic torque and the initial hill-holding torque are determined in real time based on the current road conditions, and the vehicle is controlled to enter the creeping stage (i.e., the stage where the vehicle speed relative to the ground returns from a negative value to 0) based on the creeping dynamic torque, and the vehicle speed change rate (first vehicle speed change rate) in the creeping stage (i.e., the first braking stage) is obtained, and the initial hill-holding torque is corrected based on the vehicle speed change rate in the creeping stage. Since the creeping dynamic torque and the initial hill-holding torque are both determined in real time based on the road conditions when the vehicle may reverse, and the initial hill-holding torque is corrected based on the actual vehicle speed change rate in the creeping stage to obtain the target hill-holding torque, a more accurate hill-holding target torque can be obtained to prevent or alleviate the vehicle's braking reversal, thereby improving the safety of the vehicle during braking.

[0161] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0162] Based on the same inventive concept, the embodiment of the present application also provides a reversal control device during vehicle braking for implementing the reversal control method during vehicle braking. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations of one or more embodiments of the reversal control device during vehicle braking provided below can refer to the limitations of the reversal control method during vehicle braking above, and will not be repeated here.

[0163] See also Figure 4 , Figure 4 Schematic diagram of a reverse control device during vehicle braking provided by an embodiment of the present application. Figure 4 As shown, the reverse control device during the vehicle braking process may include but is not limited to:

[0164] The processing module 401 is used to control the vehicle braking based on the electric braking target torque when the electric braking function of the vehicle is activated;

[0165] The processing module 401 is further used for clearing the electric braking target torque if a preset anti-reverse trigger condition is met during the vehicle braking process, determining the creep dynamic torque and the initial torque for holding the slope based on the current slope of the road surface, and controlling the vehicle's ground speed to return from a negative value to a value of 0 based on the creep dynamic torque;

[0166] The acquisition and correction module 402 is used to acquire the first vehicle speed change rate in the first braking stage, and correct the initial torque for holding the hill based on the first vehicle speed change rate to obtain the target torque for holding the hill; the first braking stage is the stage in which the vehicle's ground speed regresses from a negative value to a zero value;

[0167] The control module 403 is used to control the motor based on the hill-holding target torque to control the vehicle to complete braking when the preset parking condition is met.

[0168] In one embodiment, when the processing module 401 is used to control vehicle braking based on the electric braking target torque, it is specifically used to: when the electric braking function of the vehicle is activated, determine the electric braking target torque based on the vehicle's ground speed and the slope of the road on which the vehicle is located, and control the vehicle braking based on the electric braking target torque; obtain the second vehicle speed change rate of the vehicle in the second braking stage; the vehicle speed in the second braking stage is greater than 0 and less than a preset vehicle speed threshold; when the absolute value of the second vehicle speed change rate is greater than the first change rate threshold, obtain the first correction factor corresponding to the second vehicle speed change rate; the first correction factor is positively correlated with the second vehicle speed change rate, and the first correction factor is less than or equal to 1; based on the first correction factor, correct the electric braking target torque, and continue to control the vehicle braking based on the corrected electric braking target torque.

[0169] In one embodiment, the device may further include an acquisition module and a determination module. After the processing module 401 is used to continue to control the vehicle braking based on the corrected electric brake target torque, the acquisition module is used to acquire the third vehicle speed change rate of the vehicle in the third braking stage; the third braking stage is after the second braking stage and before the first braking stage; the determination module is used to determine that the preset anti-reverse trigger condition is met when the absolute value of the third vehicle speed change rate is greater than the second change rate threshold, the current gear is the forward gear, and the motor speed is less than the preset motor speed threshold.

[0170] In one embodiment, the determination module is further configured to use the corrected electric brake target torque as the hill-holding target torque when the absolute value of the third vehicle speed change rate is less than or equal to the second change rate threshold.

[0171] In one embodiment, when the acquisition and correction module 402 is used to correct the initial torque for holding the hill based on the first vehicle speed change rate to obtain the target torque for holding the hill, it is specifically used to: determine the second correction factor corresponding to the first vehicle speed change rate based on the first corresponding relationship; the first corresponding relationship includes the corresponding relationship between multiple vehicle speed change rates and multiple correction factors, and the absolute value of the vehicle speed change rate is negatively correlated with the correction factor; the second correction factor is less than 1; and correct the initial torque for holding the hill based on the second correction factor to obtain the target torque for holding the hill.

[0172] In one embodiment, when the processing module 401 is used to determine the creep dynamic torque based on the slope of the current road surface, it is specifically used to: determine the creep dynamic torque corresponding to the vehicle's current ground speed and the slope of the current road surface based on a second corresponding relationship; the second corresponding relationship includes a correspondence between multiple vehicle speed slope combinations and multiple dynamic torques, and the dynamic torque is positively correlated with the vehicle speed in the vehicle speed slope combination, and the dynamic torque is positively correlated with the slope in the vehicle speed slope combination.

[0173] In one embodiment, the device may also include an electric braking function management module, which is used to activate the electric braking function when at least one of the following conditions is met: a first condition that the key pressing duration for the target control of the vehicle is greater than a preset duration threshold; a second condition that the number of key pressings for the target control within a preset time period is greater than a preset number threshold; a third condition that the relative distance between the vehicle and the vehicle in front is less than a preset relative distance threshold, and the relative speed is greater than a preset relative speed threshold.

[0174] Each module in the above-mentioned reversal control device during vehicle braking can be implemented in whole or in part by software, hardware, or a combination thereof. Each of the above-mentioned modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a vehicle control device in the form of software, so that the processor can call and execute the corresponding operations of each of the above modules.

[0175] In an exemplary embodiment, a new energy vehicle is provided, and its internal structure diagram can be as follows: Figure 5 As shown. The new energy vehicle includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. Among them, the processor of the new energy vehicle is used to provide computing and control capabilities. The memory of the new energy vehicle includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the new energy vehicle is used to exchange information between the processor and the external device. The communication interface of the new energy vehicle is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be realized through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a reverse control method in a vehicle braking process is realized. The display unit of the new energy vehicle is used to form a visually visible picture, which can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the new energy vehicle can be a touch layer covered on the display screen, or it can be a button, trackball or touchpad set in the new energy vehicle.

[0176] Those skilled in the art will understand that Figure 5 The structure shown in the figure is only a block diagram of a part of the structure related to the scheme of the present application, and does not constitute a limitation on the new energy vehicle to which the scheme of the present application is applied. A specific new energy vehicle may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0177] In an exemplary embodiment, the present application provides a new energy vehicle, including a memory and a processor, wherein the memory stores a computer program; when the processor executes the computer program, the steps in the above-mentioned reverse control method during the vehicle braking process are implemented.

[0178] In an exemplary embodiment, the present application provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned reverse control method during vehicle braking are implemented.

[0179] In an exemplary embodiment, the present application provides a computer program product, including a computer program. When the computer program is executed by a processor, the steps in the above-mentioned reverse control method in the vehicle braking process are implemented.

[0180] It should be noted that the data involved in this application (including but not limited to electric braking target torque, creep dynamic torque, initial torque for holding hill, first vehicle speed change rate, target torque for holding hill, etc.) are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data need to comply with relevant regulations.

[0181] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and 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 the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0182] The technical features of the above embodiments may 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 application.

[0183] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A reverse control method during vehicle braking, characterized in that: include: controlling the vehicle braking based on the electric braking target torque when the electric braking function of the vehicle is activated; During the vehicle braking process, if the preset anti-reverse trigger condition is met, the electric braking target torque is cleared, the creep dynamic torque and the initial torque for holding the hill are determined based on the slope of the current road surface, and the ground speed of the vehicle is controlled to return from a negative value to a value of 0 based on the creep dynamic torque; Acquiring a first vehicle speed change rate in a first braking phase, and correcting the hill-holding initial torque based on the first vehicle speed change rate to obtain a hill-holding target torque; The first braking stage is a stage in which the ground speed of the vehicle returns from a negative value to a value of 0; When a preset parking condition is met, the motor is controlled based on the hill-parking target torque to control the vehicle to complete braking.

2. The method according to claim 1, characterized in that The controlling the vehicle braking based on the electric braking target torque comprises: When the electric brake function of the vehicle is activated, determining an electric brake target torque based on the vehicle speed relative to the ground and the slope of the road on which the vehicle is located, and controlling the braking of the vehicle based on the electric brake target torque; Acquiring a second vehicle speed change rate of the vehicle in a second braking stage; the vehicle speed relative to the ground in the second braking stage is greater than 0 and less than a preset vehicle speed threshold; When the absolute value of the second vehicle speed change rate is greater than the first change rate threshold, obtaining a first correction factor corresponding to the second vehicle speed change rate; the first correction factor is less than 1; The electric brake target torque is corrected based on the first correction factor, and the vehicle braking is continuously controlled based on the corrected electric brake target torque.

3. The method according to claim 2, characterized in that After continuing to control the vehicle braking based on the corrected electric brake target torque, the method further includes: Acquiring a third vehicle speed change rate of the vehicle in a third braking stage; the third braking stage is after the second braking stage and before the first braking stage; When the absolute value of the third vehicle speed change rate is greater than the second change rate threshold, the current gear is a forward gear, and the motor speed is less than a preset motor speed threshold, it is determined that the preset anti-reverse trigger condition is met.

4. The method according to claim 3, characterized in that The method further comprises: When the absolute value of the third vehicle speed change rate is less than or equal to the second change rate threshold, the corrected electric brake target torque is used as the hill-holding target torque.

5. The method according to claim 1, characterized in that The step of correcting the hill-holding initial torque based on the first vehicle speed change rate to obtain the hill-holding target torque includes: Based on a first corresponding relationship, determining a second correction factor corresponding to the first vehicle speed change rate; the first corresponding relationship includes a correspondence between a plurality of vehicle speed change rates and a plurality of correction factors; the second correction factor is less than 1; The hill-holding initial torque is corrected based on the second correction factor to obtain the hill-holding target torque.

6. The method according to claim 1, characterized in that The step of determining the creep dynamic torque based on the slope of the current road surface comprises: Based on the second corresponding relationship, the creep dynamic torque corresponding to the current ground speed of the vehicle and the slope of the current road surface is determined; the second corresponding relationship includes the corresponding relationship between multiple speed slope combinations and multiple dynamic torques.

7. The method according to any one of claims 1 to 6, characterized in that: Also includes: The electric braking function is activated when at least one of the following conditions is met: A first condition that the duration of pressing a key of a target control of the vehicle is greater than a preset duration threshold; A second condition that the number of key presses on the target control within a preset time period is greater than a preset number threshold; The third condition is that the relative distance between the vehicle and the preceding vehicle is less than a preset relative distance threshold, and the relative speed is greater than a preset relative speed threshold.

8. A reverse control device during vehicle braking, characterized in that: The device comprises: a processing module, configured to control the vehicle braking based on the electric braking target torque when the electric braking function of the vehicle is activated; The processing module is further configured to, during the braking process of the vehicle, if a preset anti-reverse trigger condition is met, clear the electric braking target torque, determine the creep dynamic torque and the hill-holding initial torque based on the slope of the current road surface, and control the ground speed of the vehicle to return from a negative value to a value of 0 based on the creep dynamic torque; an acquisition and correction module, configured to acquire a first vehicle speed change rate in a first braking phase, and to correct the initial slope-holding torque based on the first vehicle speed change rate to obtain a slope-holding target torque; the first braking phase is a phase in which the vehicle's ground speed regresses from a negative value to a zero value; The control module is used to control the motor based on the hill-parking target torque to control the vehicle to complete braking when a preset parking condition is met.

9. A new energy vehicle, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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