Brake torque control method, controller, storage medium and program product

Abstract

The invention discloses a braking torque control method, a controller, a storage medium and a program product, and relates to the technical field of vehicle braking control, due to the fact that when an expected braking torque is jointly achieved through a braking device and a driving motor to achieve vehicle braking, the braking device cannot provide enough braking torque in time within a delay time period, and the braking torque cannot be timely provided. The actual braking force of the braking device is obtained; controlling a driving motor to generate corresponding braking torque according to the difference value between the target braking force needing to be provided by the braking device and the actual braking force; due to the fact that the response of the driving motor is relatively fast and the driving motor has the short-time overload capacity, the braking torque corresponding to the difference value is provided through the driving motor, and part of braking torque which is not provided by the braking device in time can be compensated. Therefore, the technical problem that the driving safety of the vehicle is low due to the fact that the braking device cannot provide enough braking torque in time can be solved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle braking control, and in particular to a braking torque control method, a controller, a storage medium, and a program product. Background Art

[0002] At present, the degree to which the driver steps on the brake pedal is usually converted into a corresponding expected braking torque, or the expected braking torque is calculated according to the needs of autonomous driving, and the expected braking torque is achieved through the braking device and the drive motor to achieve vehicle braking; specifically, the expected braking torque that exceeds what the drive motor can achieve will be achieved through the braking device installed on the corresponding wheel.

[0003] However, compared with the drive motor, the brake device has a larger delay in achieving the braking torque. In the method of achieving the desired braking torque by the brake device and the drive motor together to realize the vehicle braking, the brake device cannot provide sufficient braking torque in time, thereby reducing the vehicle driving safety. Summary of the Invention

[0004] The main purpose of this application is to provide a braking torque control method, controller, storage medium and program product, aiming to solve the technical problem of low vehicle driving safety caused by the braking device being unable to provide sufficient braking torque in a timely manner.

[0005] To achieve the above objectives, the present application proposes a braking torque control method, which includes:

[0006] Obtaining the actual braking force of the braking device;

[0007] According to the difference between the target braking force required to be provided by the braking device and the actual braking force, the drive motor is controlled to generate a corresponding braking torque to compensate for the part of the braking torque that is not provided in time by the braking device.

[0008] In one embodiment, before the step of controlling the drive motor to generate a corresponding braking torque based on the difference between the target braking force required to be provided by the braking device and the actual braking force, the method further includes:

[0009] Obtain the current wheel speed and determine the target vehicle speed at the wheel speed measurement time, where the time difference between the current time and the wheel speed measurement time is the wheel speed measurement delay;

[0010] determining a wheel slip rate according to the target vehicle speed and the current wheel speed;

[0011] Whether the target braking force needs to be corrected is determined based on the wheel slip rate.

[0012] In one embodiment, the step of determining the target vehicle speed at the wheel speed measurement time includes:

[0013] Obtaining the expected braking torque at multiple moments in a preset period before the current moment;

[0014] Determining, based on the expected braking torque, a first variation curve of the expected deceleration over time within the preset period of time using a prediction model, wherein the prediction model is used to characterize a correlation between the expected braking torque and the expected deceleration at different moments;

[0015] determining a second variation curve of the expected vehicle speed over time within the preset time period based on the first variation curve;

[0016] The target vehicle speed at the wheel speed measurement time is determined according to the second variation curve.

[0017] In one embodiment, before the step of controlling the drive motor to generate a corresponding braking torque based on the difference between the target braking force required to be provided by the braking device and the actual braking force, the method further includes:

[0018] Get the current vehicle speed;

[0019] The step of determining the target vehicle speed at the wheel speed measurement time according to the second variation curve includes:

[0020] determining an expected vehicle speed at a vehicle speed measurement time according to the second variation curve, wherein a time difference between a current time and the vehicle speed measurement time is a vehicle speed measurement delay, and the vehicle speed measurement delay is greater than a wheel speed measurement delay;

[0021] When the expected vehicle speed at the vehicle speed measurement time is consistent with the current vehicle speed, determining a vehicle speed change from the vehicle speed measurement time to the wheel speed measurement time according to the second change curve;

[0022] A target vehicle speed at the time of wheel speed measurement is determined based on the vehicle speed change and the expected vehicle speed at the time of vehicle speed measurement.

[0023] In one embodiment, after the step of determining the expected vehicle speed at the vehicle speed measurement time according to the second variation curve, the method further includes:

[0024] When the expected vehicle speed at the vehicle speed measurement moment is inconsistent with the current vehicle speed, the model parameters of the prediction model are corrected.

[0025] In one embodiment, the step of determining whether the target braking force needs to be corrected based on the wheel slip rate includes:

[0026] If the wheel slip rate is greater than the absolute value of the preset maximum slip rate, determining that the target braking force needs to be corrected;

[0027] After the step of determining whether the target braking force needs to be corrected based on the wheel slip rate, the method further includes:

[0028] If it is determined that the target braking force needs to be corrected, an anti-wheel lock mechanism is activated, and the target braking force is corrected based on the wheel slip rate.

[0029] In one embodiment, before the step of determining the first variation curve of the expected deceleration over time within the preset period of time using a prediction model according to the expected braking torque, the method further includes:

[0030] When the expected braking torque is greater than the maximum braking torque allowed by the maximum friction coefficient of the wheel, the expected braking torque greater than the maximum braking torque is updated to the maximum braking torque; wherein, the maximum braking torque is determined based on the maximum friction coefficient, the vehicle mass, and the road slope angle.

[0031] In addition, to achieve the above-mentioned purpose, the present application also proposes a controller, which includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the braking torque control method as described above.

[0032] In addition, to achieve the above-mentioned purpose, the present application also proposes a storage medium, which is a computer-readable storage medium. A computer program is stored on the storage medium, and when the computer program is executed by the processor, the steps of the braking torque control method described above are implemented.

[0033] In addition, to achieve the above-mentioned purpose, the present application also provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the steps of the braking torque control method described above are implemented.

[0034] One or more technical solutions proposed in this application have at least the following technical effects:

[0035] Since the braking device and the drive motor jointly achieve the desired braking torque to achieve vehicle braking, the braking device cannot provide sufficient braking torque in time during the delay period. The present application obtains the actual braking force of the braking device; according to the difference between the target braking force required by the braking device and the actual braking force, the drive motor is controlled to generate the corresponding braking torque; since the drive motor responds relatively quickly and has a short-term overload capacity, the braking torque corresponding to the difference is provided by the drive motor, which can compensate for part of the braking torque that the braking device fails to provide in time; therefore, the present application can provide sufficient braking torque in time, thereby improving vehicle driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0037] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0038] Figure 1 A flow chart of the first embodiment of the braking torque control method of the present application;

[0039] Figure 2 A schematic diagram of a first scenario provided in Example 1 of the braking torque control method of the present application;

[0040] Figure 3 A schematic diagram of a second scenario provided in Example 1 of the braking torque control method of the present application;

[0041] Figure 4 A flow chart illustrating a second embodiment of the braking torque control method of the present application;

[0042] Figure 5 A schematic diagram of a third scenario provided in Example 2 of the braking torque control method of this application;

[0043] Figure 6 Schematic diagram of the controller structure of the hardware operating environment involved in the braking torque control method in the embodiment of the present application.

[0044] The purpose, features and advantages of this application will be further explained with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0045] It should be understood that the specific embodiments described herein are merely used to explain the technical solutions of the present application and are not intended to limit the present application.

[0046] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0047] Based on this, the embodiment of the present application provides a braking torque control method, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the braking torque control method of the present application.

[0048] In this embodiment, the braking torque control method includes steps S10 to S20:

[0049] Step S10, obtaining the actual braking force of the braking device;

[0050] It should be noted that the execution entity of the above-mentioned braking torque control method can be a controller or a braking torque control device, etc., and the following description will be made using a controller as an example; the controller can be a vehicle controller, an electronic stability controller, an anti-lock braking controller, etc.

[0051] Specifically, since the desired braking torque is usually converted into the corresponding desired braking torque according to the degree to which the driver steps on the brake pedal, or the desired braking torque is calculated according to the needs of autonomous driving, the controller will distribute the desired braking torque to the front and rear axles. The greater the required deceleration, the greater the braking torque distributed to the front axle. When a drive motor is installed on the axle, the braking torque distributed to the axle will first be distributed to the drive motor to achieve energy recovery. The desired braking torque that exceeds what the drive motor can achieve will be achieved through the brake device installed on the corresponding wheel. Figure 2 , the desired shaft braking torque is distributed to the drive motor and the brake device on the wheel; compared with the drive motor, the brake device has a larger delay in realizing the braking torque (the torque that the brake device can realize is dynamically increased, and when the required braking torque is reached, this process usually takes 150ms, that is, the brake device cannot provide sufficient braking torque in time). In the method of realizing the desired braking torque to realize vehicle braking by jointly realizing the desired braking torque by the brake device and the drive motor, the brake device cannot provide sufficient braking torque in time, thereby reducing the driving safety of the vehicle.

[0052] In order to solve the above technical problems, this embodiment aims to utilize the short-term overload capacity and fast response characteristics (usually 40ms) of the drive motor to compensate for part of the braking torque that the braking device fails to provide in time through the drive motor, thereby improving vehicle driving safety.

[0053] Specifically, the controller obtains the actual braking force T of the braking device w1_b_ac , which can determine the braking force that the braking device can currently achieve, and facilitate the determination of the braking torque that the braking device fails to provide in a timely manner.

[0054] Since the braking torque control logic of the front and rear axles is the same, this embodiment is described using the front axle as an example. If the front axle is equipped with a drive motor and the two wheels corresponding to the front axle are respectively equipped with a brake device, then the desired braking torque can be achieved by cooperating with the drive motor and the brake devices respectively installed on the two wheels corresponding to the front axle. Figure 2 At this time, it is necessary to obtain the actual braking force of the brake devices installed on the two wheels corresponding to the front axle.

[0055] If each of the four wheels is provided with a drive motor and a brake device, the desired braking torque is achieved by the cooperation of the drive motor and the brake device installed on the wheel. Figure 3 ; At this time, it is necessary to obtain the actual braking force of the brake device installed on one of the wheels.

[0056] For ease of description, this embodiment is described by taking an example where each wheel is provided with a driving motor and a braking device.

[0057] The implementation method for obtaining the actual braking force of the braking device may be: obtaining the actual braking force of the braking device through a pressure sensor, obtaining the actual braking force of the braking device through a torque sensor, etc.

[0058] Step S20 , controlling the drive motor to generate corresponding braking torque according to the difference between the target braking force required to be provided by the braking device and the actual braking force, so as to compensate for the braking torque that is not provided in time by the braking device.

[0059] It can be understood that the actual braking force of the braking device currently obtained is the braking force that the braking device can currently provide to the wheel.

[0060] Before obtaining the actual braking force of the braking device, the controller has already allocated the total braking torque required for vehicle braking to the corresponding drive motor and braking device. Therefore, the target braking torque that the braking device needs to provide is known. By dividing the target braking torque by the wheel radius, the target braking force T that the braking device needs to provide can be obtained. w1_b .

[0061] If the difference between the target braking force that the braking device needs to provide and the actual braking force is greater than a preset value (greater than 0 or greater than the allowable error value), it is considered that the braking device has not provided sufficient braking torque in a timely manner, that is, it is necessary to compensate the braking torque through the drive motor; if the difference between the target braking force that the braking device needs to provide and the actual braking force is equal to the preset value, it is considered that the braking device has provided sufficient braking torque in a timely manner, that is, it is not necessary to compensate the braking torque through the drive motor.

[0062] Therefore, the controller can adaptively control the drive motor to generate a corresponding braking torque according to the difference between the target braking force and the actual braking force required to be provided by the braking device; the corresponding braking torque refers to a braking torque that is the same as the difference.

[0063] When the difference between the target braking force that the braking device needs to provide and the actual braking force is equal to a preset value, it is considered that the drive motor does not need to generate a corresponding braking torque; when the difference between the target braking force that the braking device needs to provide and the actual braking force is greater than a preset value, it is considered that the drive motor needs to generate a corresponding braking torque, thereby compensating for part of the braking torque that the braking device has not provided in time, and providing the corresponding braking force to the wheel in time.

[0064] It should be noted that since the drive motor itself needs to realize the braking torque pre-allocated by the controller, when the braking device cannot provide part of the braking torque in time, this embodiment utilizes the fast response characteristics of the drive motor and the short-term overload capacity of the drive motor to provide a braking torque that exceeds what the drive motor can provide in a short time through the drive motor, which will not affect the performance of the drive motor.

[0065] In order to further ensure that the performance of the drive motor is not affected, this embodiment can also obtain the temperature of the drive motor. If the temperature of the drive motor is within the preset normal temperature range, the drive motor can provide additional braking torque corresponding to the difference; if the temperature of the drive motor is not within the preset normal temperature range, after detecting that the temperature has returned to normal, the drive motor can be controlled to generate corresponding braking torque based on the difference between the target braking force and the actual braking force required by the braking device.

[0066] In this embodiment, due to the fast response characteristics of the drive motor and the short-term overload capacity of the drive motor, the drive motor provides a braking torque corresponding to the difference, that is, through the dynamic coordination of the drive motor and the braking device, it is possible to compensate for part of the braking torque that is not provided in time by the braking device, thereby achieving timeliness of control; therefore, the present application can provide sufficient braking torque in a timely manner to maximize the satisfaction of the expected braking torque, thereby ensuring both transient response and accurate realization of the braking torque, thereby improving vehicle driving safety.

[0067] According to the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can be referred to the above introduction and will not be described in detail later. Figure 4 Before step S20, steps S01 to S03 are also included:

[0068] Step S01, obtaining the current wheel speed and determining the target vehicle speed at the wheel speed measurement time, wherein the time difference between the current time and the wheel speed measurement time is the wheel speed measurement delay;

[0069] Step S02, determining the wheel slip rate according to the target vehicle speed and the current wheel speed;

[0070] It should be noted that if the braking device cannot provide sufficient braking torque in time, the speed of increase of the braking force cannot be accurately controlled, which will cause the slip rate (the degree of sliding of the vehicle tires during driving) to quickly exceed the critical value, easily leading to wheel locking; or the required braking force cannot be achieved in time, resulting in the vehicle being unable to brake in time, reducing vehicle driving safety.

[0071] This embodiment aims to improve the control accuracy of the braking torque, thereby improving the slip rate control accuracy and vehicle driving safety.

[0072] Specifically, since the slip rate is affected by the vehicle speed and wheel speed, the vehicle speed and wheel speed obtained by the controller during the slip rate control process will have different delays due to different measurement methods; specifically, the current wheel speed can be obtained by measuring through a wheel speed sensor, and the currently obtained wheel speed usually reflects the actual wheel speed of the vehicle 40 milliseconds ago.

[0073] Therefore, in order to improve the accuracy of slip ratio control, this embodiment can align the vehicle speed and wheel speed, that is, obtain the vehicle speed and wheel speed at the same measurement time, and perform slip ratio control based on the vehicle speed and wheel speed at the same measurement time, so as to avoid the error caused by calculating the slip ratio based on the vehicle speed and wheel speed measured at different times, thereby improving the accuracy of slip ratio control.

[0074] Specifically, the current wheel speed can be obtained, and the target vehicle speed at the wheel speed measurement moment can be determined; the wheel slip rate can be determined based on the target vehicle speed and the current wheel speed; the current vehicle speed can also be obtained, and the target wheel speed at the vehicle speed measurement moment can be determined; the wheel slip rate can be determined based on the target wheel speed and the vehicle speed; compared with the wheel speed measurement delay, the vehicle speed measurement delay is longer, which has a greater impact on the timeliness of vehicle control, and, since the vehicle mass is larger than the wheel, the prediction of the changing trend of the vehicle speed will be more accurate; therefore, this embodiment preferably obtains the vehicle speed and wheel speed at the same measurement moment, and the implementation method for slip rate control based on the vehicle speed and wheel speed at the same measurement moment is: obtain the current wheel speed, and determine the target vehicle speed at the wheel speed measurement moment, and determine the wheel slip rate based on the target vehicle speed and the current wheel speed.

[0075] Specifically, assume that the two wheels corresponding to the front axle are ω w1 and ω w2 When the current wheel speed is measured by the wheel speed sensor, the wheel speed measurement delay is usually: τ 轮速 =40ms. Correspondingly, determining the target vehicle speed at the wheel speed measurement time is to determine the actual target vehicle speed of the vehicle at the time 40ms before the current time.

[0076] Furthermore, the wheel slip ratio is determined based on the current wheel speed and the target vehicle speed obtained 40 ms before the current wheel speed. The calculation formula can be expressed as: wheel slip ratio = (ω w_测量 -ω v( t-τ 轮速 )) / ω v (t-τ 轮速 ); where ω w_测量 is the current wheel speed, ω v (t-τ 轮速 ) is the target vehicle speed obtained 40ms before the current moment.

[0077] Step S03: Determine whether the target braking force needs to be corrected based on the wheel slip rate.

[0078] Based on the wheel slip rate calculated above, it is determined whether the target braking force needs to be corrected, thereby achieving precise slip rate control and improving vehicle driving safety.

[0079] Specifically, based on the wheel slip rate, it is determined whether the target braking force needs to be corrected: if the wheel slip rate is greater than the absolute value of the preset maximum slip rate, it is determined that the target braking force needs to be corrected; for example, if it is determined that the wheel slip rate is less than the absolute value of the allowable maximum slip rate (for example, less than -10% or greater than 10%), it is determined that the target braking force needs to be corrected.

[0080] Furthermore, after determining whether the target braking force needs to be corrected based on the wheel slip rate, if it is determined that the target braking force needs to be corrected, the anti-wheel lock mechanism is activated, and the target braking force is corrected based on the wheel slip rate. The corrected target braking force ensures that the slip rate does not exceed the absolute value of the above-mentioned preset maximum slip rate.

[0081] In this embodiment, by acquiring the vehicle speed and wheel speed at the same measurement moment and performing slip control based on these measurements, errors caused by calculating the slip ratio based on vehicle speeds and wheel speeds measured at different times are avoided, thereby improving slip ratio control accuracy. When the target braking force needs to be revised, the anti-lock mechanism is activated and the target braking force is revised based on the wheel slip ratio. The revised target braking force ensures that the slip ratio does not exceed the absolute value of the preset maximum slip ratio, achieving real-time slip ratio control. This minimizes the risk of wheel lock while maximizing the desired braking torque, ensuring vehicle driving safety.

[0082] According to the first and second embodiments of the present application, in the third embodiment of the present application, the same or similar contents as those of the first embodiment can be referred to above and will not be described in detail. On this basis, the specific implementation method for determining the target vehicle speed at the time of wheel speed measurement can be:

[0083] Obtain the expected braking torque at multiple moments within a preset time period before the current moment; determine a first variation curve of the expected deceleration over time within the preset time period based on the expected braking torque through a prediction model, wherein the prediction model is used to characterize the correlation between the expected braking torque and the expected deceleration at different moments; determine a second variation curve of the expected vehicle speed over time within the preset time period based on the first variation curve; determine the target vehicle speed at the moment of wheel speed measurement based on the second variation curve.

[0084] It should be noted that the controller cannot obtain the specific vehicle speed within the measurement delay period, resulting in the inability to determine the target vehicle speed at the wheel speed measurement time. This embodiment aims to determine the target vehicle speed at the wheel speed measurement time by simulating the change pattern of vehicle speed over time, thereby improving the accuracy of slip rate control.

[0085] Specifically, since the vehicle speed is affected by the expected braking torque during vehicle driving, this embodiment obtains the expected braking torque at multiple moments in the previous preset period corresponding to the current moment, and calculates the expected braking torque T at multiple moments in the previous preset period based on a prediction model that can characterize the correlation between the expected braking torque and the expected deceleration at different moments. b_期望 (t) is analyzed to obtain a first variation curve a_ of the expected deceleration over time within a preset period of time. b _ 期望( t), refer to Figure 3 .

[0086] In which, the prediction model can be determined through vehicle simulation data, the preset time period can be any time period covering the measurement delay time period, and the expected braking torque at multiple moments within the preset time period can be the expected braking torque at multiple moments such as the first 5ms, the first 10ms,..., the first 80ms, and the first 85ms.

[0087] Among them, the expression of the prediction model can be:

[0088] -F_b_desired=-T_b_desired / R=Mv_total*a_b_desired+Mv*g*sin(alfa)+F_resistance;

[0089] Among them, reference Figure 5 , F_ 阻力 is the resistance of the car (resistance is a function of speed), R is the wheel radius, Mv is the mass of the car, Mv_ 全 is the total mass of the car when accelerating, taking into account the moment of inertia of the wheels, g is the acceleration due to gravity, alfa is the slope angle of the road, and F_ b _Expectation is the expected braking force, a_ b _Expected is the expected deceleration, T_ b _ 期望is the desired braking torque.

[0090] Furthermore, based on the first variation curve, a second variation curve of the expected vehicle speed over time within a preset period is determined; that is, the expected vehicle speed corresponding to multiple moments is predicted. Specifically, the first variation curve can be integrated to obtain a variation curve V_ of the expected vehicle speed over time within the preset period. 期望 (t). Based on the expected speed change curve over time in the preset period and the wheel radius, a second change curve ω of the expected speed change curve over time in the preset period is calculated. v_期望 (t); The target vehicle speed at the wheel speed measurement time can be determined based on the second variation curve.

[0091] Before the step of controlling the drive motor to generate corresponding braking torque according to the difference between the target braking force required to be provided by the braking device and the actual braking force, the current vehicle speed may be obtained.

[0092] Specifically, the current vehicle speed can be obtained by first obtaining the current vehicle speed, dividing the current vehicle speed by the wheel radius R, and obtaining the current vehicle speed V, and the vehicle speed ω corresponding to the vehicle speed divided by the wheel radius R. v =V / R; where the vehicle speed can be obtained through satellite positioning, or by measuring the average speed of the vehicle's four wheels when the tires are not slipping. The delay in measuring the vehicle speed is greater than the delay in measuring the wheel speed. The delay in measuring the vehicle speed is usually: τ 车速 =80ms.

[0093] The implementation method for determining the target vehicle speed at the wheel speed measurement time according to the second variation curve may be:

[0094] According to the second change curve, the expected vehicle speed at the vehicle speed measurement moment is determined, wherein the time difference between the current moment and the vehicle speed measurement moment is the vehicle speed measurement delay, and the vehicle speed measurement delay is greater than the wheel speed measurement delay; when the expected vehicle speed at the vehicle speed measurement moment is consistent with the current vehicle speed, according to the second change curve, the vehicle speed change from the vehicle speed measurement moment to the wheel speed measurement moment is determined; according to the vehicle speed change and the expected vehicle speed at the vehicle speed measurement moment, the target vehicle speed at the wheel speed measurement moment is determined.

[0095] Specifically, since the time difference between the current moment and the vehicle speed measurement moment is the vehicle speed measurement delay, and the vehicle speed measurement delay is greater than the wheel speed measurement delay, the expected vehicle speed ω at the vehicle speed measurement moment can be determined based on the second variation curve. v_期望 (t-τ 车速), determine whether the expected vehicle speed at the vehicle speed measurement moment is consistent with the current vehicle speed. If they are consistent, it is considered that the expected vehicle speed at the vehicle speed measurement moment estimated by the prediction model is consistent with the actual vehicle speed at the vehicle speed measurement moment.

[0096] Therefore, the vehicle speed change from the vehicle speed measurement time to the wheel speed measurement time can be further determined based on the second change curve; thereby, the target vehicle speed at the wheel speed measurement time can be determined based on the vehicle speed change and the expected vehicle speed at the vehicle speed measurement time.

[0097] For example, the wheel speed measurement time is 40ms before the current time, and the vehicle speed measurement time is 80ms before the current time. The estimated target vehicle speed at the time 80ms before the current time is determined from the second change curve, that is, the expected vehicle speed at the vehicle speed measurement time is obtained. If the target vehicle speed at the time 80ms before the current time is consistent with the current vehicle speed, the vehicle speed change from 80ms before the current time to 40ms before the current time can be determined according to the second change curve; the target vehicle speed 40ms before the current time is obtained by superimposing the vehicle speed change on the basis of the expected vehicle speed at the vehicle speed measurement time, that is, the target vehicle speed at the wheel speed measurement time is obtained; thereby ensuring that the estimated vehicle speed is synchronized with the vehicle speed at the wheel speed measurement time.

[0098] Specifically, the calculation formula for determining the target vehicle speed at the wheel speed measurement time can be expressed as:

[0099] ω v (t-τ 轮速 )=ω v_测量 +ω v_期望 (t-τ 轮速 )-ω v_期望 (t-τ 车速 );

[0100] That is, the vehicle speed ω at the time of wheel speed measurement v( t-τ 轮速 ) = current vehicle speed ω v_测量 +Expected vehicle speed at the time of wheel speed measurementω v_期望 (t-τ 轮速 )-the expected vehicle speed at the time of vehicle speed measurement ω v_期望 (t-τ 车速 )).

[0101] In order to ensure the prediction accuracy of the prediction model, the prediction model can be dynamically optimized during the braking control process. Specifically, after determining the expected vehicle speed at the vehicle speed measurement moment based on the second change curve, when the expected vehicle speed at the vehicle speed measurement moment is inconsistent with the current vehicle speed, the model parameters of the prediction model are corrected.

[0102] Specifically, due to the model parameter F_ 阻力 Affects the deceleration, thus affecting the vehicle speed, and the resistance received by the vehicle changes in real time. By modifying the model parameter F_ 阻力 , which can improve the prediction accuracy of the prediction model and make the model estimation speed and measurement speed as consistent as possible under normal circumstances.

[0103] Specifically, before the step of determining the first change curve of the expected deceleration over time within a preset time period based on the expected braking torque through a prediction model, when the expected braking torque is greater than the maximum braking torque allowed by the maximum friction coefficient of the wheel, the expected braking torque greater than the maximum braking torque is updated to the maximum braking torque; wherein, the maximum braking torque is determined based on the maximum friction coefficient, the total vehicle mass, and the road slope angle.

[0104] In order to ensure that the results of the prediction model estimation can meet the actual vehicle operation standards, among the expected braking torques obtained at multiple moments, if there is a maximum friction coefficient u_ 最大 If the expected braking torque is equal to the maximum braking torque allowed, the expected braking torque that is greater than the maximum braking torque needs to be updated to the maximum braking torque, that is, the expected braking torque is limited to the maximum braking torque.

[0105] Specifically, the maximum braking torque is determined based on the maximum friction coefficient, the vehicle mass, and the road slope angle. Based on the maximum friction coefficient, the vehicle mass, and the road slope angle, the calculation formula for determining the maximum braking torque may be:

[0106] T_b_max=F_b_max*R=u_max*Mv*g*cos(alfa).

[0107] In this embodiment, the speed of the vehicle is estimated by a prediction model, the model parameters are corrected in real time based on a synchronous comparison between the estimated value and the measured value of the prediction model, and the vehicle speed at the time of wheel speed measurement is determined based on the result of the prediction model. By using the synchronized vehicle speed and wheel speed with less delay as input, the response speed and accuracy of the anti-lock control process are improved; at the same time, the vehicle calibration work is reduced, and the vehicle driving safety is improved while optimizing the braking torque.

[0108] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the braking torque control method of the present application. More simple transformations based on this technical concept are all within the scope of protection of the present application.

[0109] The present application provides a controller, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the braking torque control method in the above-mentioned embodiment one.

[0110] Reference below Figure 6 , which shows a schematic diagram of the structure of a controller suitable for implementing the embodiments of the present application. The controller in the embodiments of the present application may include, but is not limited to, mobile terminals such as mobile phones, tablet computers, laptop computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PMPs (Portable Media Players), in-vehicle terminals (such as in-vehicle navigation terminals), and fixed terminals such as digital televisions and desktop computers. Figure 6 The controller shown is merely an example and should not limit the functions and scope of use of the embodiments of the present application.

[0111] like Figure 6 As shown, the controller may include a processing device 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 1002 or a program loaded from a storage device 1003 into a random access memory (RAM) 1004. Various programs and data required for controller operation are also stored in RAM 1004. The processing device 1001, ROM 1002, and RAM 1004 are connected to each other via a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to the I / O interface 1006: an input device 1007 including, for example, a touch screen, touchpad, keyboard, mouse, image sensor, microphone, accelerometer, gyroscope, etc.; an output device 1008 including, for example, a liquid crystal display (LCD), speaker, vibrator, etc.; a storage device 1003 including, for example, a magnetic tape, hard disk, etc.; and a communication device 1009. Communication device 1009 can allow the controller to communicate with other devices wirelessly or wired to exchange data. Although the figure shows a controller with various systems, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems can be implemented or have instead.

[0112] In particular, according to the embodiments disclosed in the present application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, the embodiments disclosed in the present application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program comprising program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network via a communication device, or installed from a storage device 1003, or installed from a ROM 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the method of the embodiment disclosed in the present application are executed.

[0113] The controller provided in this application, employing the braking torque control method of the aforementioned embodiment, can resolve the technical problem of reduced vehicle driving safety caused by the braking device's inability to provide sufficient braking torque in a timely manner. Compared to the prior art, the controller provided in this application achieves the same beneficial effects as the braking torque control method provided in the aforementioned embodiment. Other technical features of this controller are the same as those disclosed in the aforementioned embodiment and are not further elaborated here.

[0114] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0115] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

[0116] The present application provides a computer-readable storage medium having computer-readable program instructions (ie, a computer program) stored thereon, wherein the computer-readable program instructions are used to execute the braking torque control method in the above-mentioned embodiment.

[0117] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, systems or devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, system or device. The program code contained on the computer-readable storage medium may be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0118] The computer-readable storage medium may be included in the controller, or may exist independently without being assembled into the controller.

[0119] The computer-readable storage medium carries one or more programs. When the one or more programs are executed by the controller, the controller is caused to: execute the braking torque control method.

[0120] Computer program code for performing the operations of the present application may be written in one or more programming languages, or a combination thereof, including object-oriented programming languages such as Java, Smalltalk, C++, and conventional procedural programming languages such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on the remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0121] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to the various embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, program segment or a part of code, and the module, program segment or a part of code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order than that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of the boxes in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system that performs the specified function or operation, or can be implemented by a combination of dedicated hardware and computer instructions.

[0122] The modules described in the embodiments of the present application may be implemented in software or hardware, wherein the name of a module does not necessarily limit the unit itself.

[0123] The computer-readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the aforementioned braking torque control method. This computer-readable storage medium can address the technical issue of reduced vehicle driving safety caused by the braking device's inability to provide sufficient braking torque in a timely manner. Compared to the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as those of the braking torque control method provided in the aforementioned embodiments, and are not further elaborated here.

[0124] The present application also provides a computer program product, comprising a computer program, which implements the steps of the above-mentioned braking torque control method when executed by a processor.

[0125] The computer program product provided in this application can address the technical issue of reduced vehicle driving safety caused by the braking device's inability to provide sufficient braking torque in a timely manner. Compared to the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the braking torque control method provided in the aforementioned embodiment, and are not further elaborated here.

[0126] The above description is only part of the embodiments of the present application and does not limit the patent scope of the present application. All equivalent structural transformations made by using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A braking torque control method, characterized in that: The method includes: Obtaining the actual braking force of the braking device; According to the difference between the target braking force required to be provided by the braking device and the actual braking force, the drive motor is controlled to generate a corresponding braking torque to compensate for the part of the braking torque that is not provided in time by the braking device.

2. The method according to claim 1, wherein Before the step of controlling the drive motor to generate a corresponding braking torque according to the difference between the target braking force required to be provided by the braking device and the actual braking force, the method further includes: Obtain the current wheel speed and determine the target vehicle speed at the wheel speed measurement time, where the time difference between the current time and the wheel speed measurement time is the wheel speed measurement delay; determining a wheel slip rate according to the target vehicle speed and the current wheel speed; Whether the target braking force needs to be corrected is determined based on the wheel slip rate.

3. The method according to claim 2, wherein The step of determining the target vehicle speed at the wheel speed measurement time includes: Obtaining the expected braking torque at multiple moments in a preset period before the current moment; Determining, based on the expected braking torque, a first variation curve of the expected deceleration over time within the preset period of time using a prediction model, wherein the prediction model is used to characterize a correlation between the expected braking torque and the expected deceleration at different moments; determining a second variation curve of the expected vehicle speed over time within the preset time period based on the first variation curve; The target vehicle speed at the wheel speed measurement time is determined according to the second variation curve.

4. The method according to claim 3, wherein Before the step of controlling the drive motor to generate a corresponding braking torque according to the difference between the target braking force required to be provided by the braking device and the actual braking force, the method further includes: Get the current vehicle speed; The step of determining the target vehicle speed at the wheel speed measurement time according to the second variation curve includes: determining an expected vehicle speed at a vehicle speed measurement time according to the second variation curve, wherein a time difference between a current time and the vehicle speed measurement time is a vehicle speed measurement delay, and the vehicle speed measurement delay is greater than a wheel speed measurement delay; When the expected vehicle speed at the vehicle speed measurement time is consistent with the current vehicle speed, determining a vehicle speed change from the vehicle speed measurement time to the wheel speed measurement time according to the second change curve; A target vehicle speed at the time of wheel speed measurement is determined based on the vehicle speed change and the expected vehicle speed at the time of vehicle speed measurement.

5. The method according to claim 4, wherein After the step of determining the expected vehicle speed at the vehicle speed measurement time according to the second variation curve, the method further includes: When the expected vehicle speed at the vehicle speed measurement moment is inconsistent with the current vehicle speed, the model parameters of the prediction model are corrected.

6. The method according to claim 3, wherein The step of determining whether the target braking force needs to be corrected based on the wheel slip rate includes: If the wheel slip rate is greater than the absolute value of the preset maximum slip rate, determining that the target braking force needs to be corrected; After the step of determining whether the target braking force needs to be corrected based on the wheel slip rate, the method further includes: If it is determined that the target braking force needs to be corrected, an anti-wheel lock mechanism is activated, and the target braking force is corrected based on the wheel slip rate.

7. The method according to claim 3, wherein Before the step of determining a first variation curve of the expected deceleration over time within the preset period of time by using a prediction model according to the expected braking torque, the method further includes: When the expected braking torque is greater than the maximum braking torque allowed by the maximum friction coefficient of the wheel, the expected braking torque greater than the maximum braking torque is updated to the maximum braking torque; wherein, the maximum braking torque is determined based on the maximum friction coefficient, the vehicle mass, and the road slope angle.

8. A controller, characterized in that: The controller includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the braking torque control method according to any one of claims 1 to 7.

9. A storage medium, characterized in that: The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, the steps of the braking torque control method according to any one of claims 1 to 7 are implemented.

10. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the steps of the braking torque control method according to any one of claims 1 to 7 are implemented.

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