Brake control method, controller, medium, product and vehicle

Abstract

The invention relates to a braking control method, a controller, a medium, a product and a vehicle, a braking torque curve is obtained under the condition that the vehicle has a braking demand, the braking torque curve comprises at least two braking torques with a braking sequence and switching control parameters of the adjacent braking torques, and the switching control parameters are determined according to the braking torque curve. The braking torque in the later braking sequence is smaller than the braking torque in the first braking sequence; and controlling the braking motion of the vehicle based on the braking torque in the braking torque curve and the switching control parameter. On the basis, the braking motion of the vehicle is controlled by adopting the braking torque curve comprising a plurality of braking torques with different magnitudes and different braking sequences, so that the pitching impact of the vehicle during parking is relieved by reducing the braking torque, and the user experience is improved.

Description

Technical Field

[0001] The present application relates to the field of brake control technology, and in particular to a brake control method, controller, medium, product and vehicle. Background Art

[0002] When existing vehicles brake, the longitudinal force of the ground causes the elastic elements in the vehicle suspension to continuously compress or stretch, resulting in corresponding pitching motion and longitudinal impact on the vehicle body, which has a negative impact on the passenger's riding comfort and the driver's handling stability.

[0003] The existing braking method has the problem of generating a large pitching impact due to the large longitudinal force of the ground, which affects the user experience. Summary of the Invention

[0004] Embodiments of the present application provide a braking control method, a controller, a storage medium, a computer program product, and a vehicle, which control the braking motion of the vehicle by adopting a braking torque curve including multiple braking torques of different sizes and different braking sequences, so as to improve the user experience by reducing the braking torque to smooth the pitch impact of the vehicle when parking.

[0005] An embodiment of the present application provides a braking control method, including: When the vehicle has a braking demand, a braking torque curve is obtained, wherein the braking torque curve includes at least two braking torques having a braking sequence and a switching control parameter of adjacent braking torques, and a braking torque in a later braking sequence is smaller than a braking torque in an earlier braking sequence; Based on the braking torque in the braking torque curve and the switching control parameter, a braking movement of the vehicle is controlled.

[0006] In addition, an embodiment of the present application also provides a controller, including one or more processors and a memory, wherein the memory stores a computer program, and the processor is used to run the computer program in the memory to implement the braking control method provided in the embodiment of the present application.

[0007] In addition, an embodiment of the present application also provides a storage medium, which stores a computer program. When the computer program runs on a controller, the computer program is used to enable the controller to execute any one of the braking control methods provided in the embodiment of the present application.

[0008] In addition, an embodiment of the present application also provides a computer program product, including a computer program or instructions, which, when executed by a processor, implements any one of the braking control methods provided in the embodiments of the present application.

[0009] In addition, an embodiment of the present application also provides a vehicle, including the above-mentioned controller.

[0010] In an embodiment of the present application, a braking torque curve is obtained when a vehicle has a braking demand. The braking torque curve includes at least two braking torques in a braking sequence and switching control parameters for adjacent braking torques, where the braking torque for a later braking sequence is less than the braking torque for an earlier braking sequence. The braking motion of the vehicle is controlled based on the braking torques and switching control parameters in the braking torque curve. Based on this, by using a braking torque curve containing multiple braking torques of varying magnitudes and in different braking sequences, the braking motion of the vehicle is controlled, thereby reducing the braking torque to mitigate the pitching shock of the vehicle during parking and improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0012] Figure 1 This is a schematic diagram of an implementation environment scenario of the braking control method provided in an embodiment of the present application; Figure 2 is a flow chart of a braking control method provided in an embodiment of the present application; Figure 3 1 is a schematic diagram of a braking torque curve of the braking control method provided in an embodiment of the present application; Figure 4 : is a comparison diagram of pitch angular velocity simulation of different candidate braking torque curves and a fixed braking torque curve provided in an embodiment of the present application; Figure 5 Schematic diagram of the structure of the vehicle body-suspension-tire coupling system provided in an embodiment of the present application; Figure 6 is a schematic diagram of a half-active suspension vehicle dynamics model provided in an embodiment of the present application; Figure 7 This is a schematic diagram of a Class C road noise interference input simulation provided in an embodiment of the present application; Figure 8 is a specific flow chart of the braking control method provided in an embodiment of the present application; Figure 9 : is a schematic diagram of the simulation of the front and rear wheel braking torque input curves provided in an embodiment of the present application; Figure 10 : This is a comparison diagram of simulated pitch angular velocity of the active suspension without a controller, with a PID controller, and with a fuzzy PID controller, provided in the embodiments of the present application; Figure 11 This is a comparison chart of pitch angular velocity simulations without pitch motion adjustment, using only active suspension adjustment, using only comfort braking torque curve adjustment, and using combined control adjustment, provided in the embodiments of the present application; Figure 12 This is a diagram of a braking strategy architecture for different road adhesion coefficients provided in an embodiment of the present application; Figure 13 It is a schematic diagram of the structure of the controller provided in the embodiment of the present application. DETAILED DESCRIPTION

[0013] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0014] In addition, the term "a plurality of" in the embodiments of the present application refers to two or more than two. The terms "first" and "second" in the embodiments of the present application are used to distinguish descriptions and should not be understood to imply relative importance.

[0015] Research has found that when existing vehicles brake, the longitudinal ground force causes the elastic elements in the vehicle's suspension to continuously compress or expand, resulting in corresponding pitch motion and longitudinal impact on the vehicle body. This negatively impacts both passenger comfort and driver stability. In particular, when the amplitude of the vehicle's pitch angular velocity is excessive, passengers are prone to symptoms such as dizziness and nausea. Adjusting the dynamic characteristics of the vehicle's pitch motion is currently an important research direction for improving passenger comfort.

[0016] To solve the above problems, embodiments of the present application provide a braking control method, a controller, a storage medium, a computer program product, and a vehicle. The braking control method can be applied to a controller, which can be a server or a terminal.

[0017] Among them, the server can be an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, network acceleration services (Content Delivery Network, CDN), as well as big data and artificial intelligence platforms.

[0018] The terminal may be a smartphone, tablet computer, laptop computer, desktop computer, smart speaker, smart watch, etc., but is not limited thereto. The terminal and the server may be connected directly or indirectly via wired or wireless communication, and this application does not impose any restrictions thereon.

[0019] See also Figure 1 , taking the application of the braking control method in the controller as an example, Figure 1 This is a schematic diagram of an implementation scenario of the braking control method provided in an embodiment of the present application, wherein the controller can be a terminal device. When a vehicle has a braking demand, a braking torque curve is obtained, wherein the braking torque curve includes at least two braking torques with a braking sequence and switching control parameters for adjacent braking torques, wherein the braking torque of a later braking sequence is less than the braking torque of an earlier braking sequence. The braking motion of the vehicle is controlled based on the braking torque and switching control parameters in the braking torque curve. Based on this, by using a braking torque curve containing multiple braking torques of different sizes and different braking sequences, the braking motion of the vehicle is controlled, thereby reducing the braking torque to smooth the pitch impact of the vehicle during parking, thereby improving the user experience.

[0020] It should be noted that Figure 1 The schematic diagram of the implementation environment scenario of the braking control method shown is merely an example. The implementation environment scenario of the braking control method described in the embodiments of this application is intended to more clearly illustrate the technical solutions of the embodiments of this application and does not constitute a limitation of the technical solutions provided by the embodiments of this application. Persons skilled in the art will appreciate that with the evolution of data processing and the emergence of new business scenarios, the technical solutions provided in this application will also be applicable to similar technical problems.

[0021] The solutions provided in the embodiments of the present application are specifically described by the following embodiments. It should be noted that the description order of the following embodiments does not limit the preferred order of the embodiments.

[0022] This embodiment will be described from the perspective of a braking control method. The braking control method can be specifically applied in a controller, which can be a terminal and / or a server, and this application does not limit this.

[0023] See also Figure 2 , Figure 2 : is a flowchart of a braking control method provided by an embodiment of the present application. The braking control method may include the following steps S101 to S102: S101. When a vehicle has a braking demand, obtain a braking torque curve, wherein the braking torque curve includes at least two braking torques having a braking sequence and switching control parameters of adjacent braking torques, and a braking torque in a later braking sequence is smaller than a braking torque in an earlier braking sequence.

[0024] The vehicle refers to a vehicle that needs to be braked, and the braking demand refers to the need for the vehicle to be braked.

[0025] The braking torque curve is used to describe the relationship between the braking torque and a parameter during the vehicle's braking process. The parameter may include, but is not limited to, time, brake pressure, vehicle speed, brake temperature, etc. The specific parameters can be adjusted according to actual conditions and are not limited in this embodiment of the application.

[0026] For example, see Figure 3 , Figure 3 This is a schematic diagram of the braking torque curve provided by the embodiment of the present application. Figure 3 As shown in FIG, the braking torque curve is used to describe the change of the braking torque over time during the braking process of the vehicle.

[0027] The number of braking torques included in the braking torque curve can be adjusted according to actual conditions and is not limited in the embodiments of the present application. For example, the braking torque curve includes a first braking torque and a second braking torque, and the braking order of the first braking torque is before the braking order of the second braking torque. For another example, the braking torque curve includes three specified torques, namely braking torque A, braking torque B, and braking torque C. The braking order of braking torque A is before the braking order of braking torque B, and the braking order of braking torque B is before the braking order of braking torque C.

[0028] Among them, braking torque refers to the torque applied by the braking system to the wheels or drive shaft of the vehicle, which is used to hinder the movement of the vehicle and slow down or stop the vehicle.

[0029] The switching control parameter is used to control the switching from the braking torque of the first braking sequence to the braking torque of the last braking sequence. The number of switching control parameters is related to the number of braking torques included in the braking torque curve. For example, when the braking torque curve includes three braking torques, the number of switching control parameters is two.

[0030] It should be noted that the embodiment of the present application changes the previously fixed braking torque curve. When the switching control parameters are met, the braking system changes the braking torque according to the braking torque curve, controls the braking movement of the vehicle with a smaller braking torque, and improves the user experience by reducing the braking torque to smooth the pitch impact of the vehicle when parking.

[0031] S102 : Control the braking motion of the vehicle based on the braking torque in the braking torque curve and the switching control parameter.

[0032] As can be seen, the braking control method provided in the embodiments of the present application obtains a braking torque curve when the vehicle has a braking demand. The braking torque curve includes at least two braking torques with a braking sequence and switching control parameters for adjacent braking torques, where the braking torque of a later braking sequence is less than the braking torque of an earlier braking sequence. The braking motion of the vehicle is controlled based on the braking torques and switching control parameters in the braking torque curve. Based on this, by using a braking torque curve containing multiple braking torques of varying magnitudes and braking sequences to control the braking motion of the vehicle, the braking torque is reduced to smooth the pitching impact of the vehicle during parking, thereby improving the user experience.

[0033] It should be noted that the switching control parameters may include various types of data, the specific content of which may be adjusted according to the braking torque curve, which is not limited in the present embodiment. For example, when the braking torque curve is the changing relationship between the braking torque and time, the switching control parameters may include the starting time of the torque drop and the ending time of the torque drop. Figure 3 Where t1 is the start time of the torque reduction, and t2 is the end time of the torque reduction. For another example, when the braking torque curve represents the relationship between braking torque and vehicle speed, the switching control parameter may include a preset speed to which the vehicle speed must be reduced when a specific torque switching is required.

[0034] In some embodiments, the handover control parameters include handover start conditions.

[0035] The switching start condition refers to the condition that triggers the start of switching the braking torque.

[0036] The switching start condition includes that the vehicle speed is reduced to a preset speed, and / or the braking moment of the braking movement of the vehicle controlled based on the braking torque reaches the torque reduction start moment.

[0037] When the above-mentioned braking torque curve includes a first braking torque and a second braking torque, and the braking order of the first braking torque is before the braking order of the second braking torque, and the above-mentioned switching starting condition indicates switching from the first braking torque to the second braking torque, the above-mentioned process of controlling the braking movement of the vehicle based on the braking torque in the braking torque curve and the switching control parameters may include: controlling the braking movement of the vehicle based on the first braking torque; and when the switching starting condition is met, controlling the switching of the first braking torque to the second braking torque based on the switching control parameters to continue controlling the braking movement of the vehicle.

[0038] In some embodiments, the switching control parameter further includes a torque reduction speed.

[0039] Based on this, the above-mentioned process of switching the first braking torque to the second braking torque based on the switching control parameters to continue to control the braking movement of the vehicle may include: controlling the braking torque of the vehicle to be reduced from the first braking torque to the second braking torque according to the torque reduction speed; and continuing to control the braking movement of the vehicle based on the second braking torque.

[0040] In some embodiments, the switching control parameters further include a torque reduction end time, which is used to indicate an end time for reducing the vehicle's braking torque. At the torque reduction end time, the vehicle's braking torque is the second braking torque.

[0041] In some embodiments, when the vehicle has a braking demand, the process of obtaining the braking torque curve may include the following steps: When the vehicle has a braking demand, predict the deceleration curve and pitch angular velocity curve of the vehicle during the braking process; determining an optimization target required for generating a braking torque curve according to the pitching angular velocity curve, and determining a constraint condition required for generating the braking torque curve according to the deceleration curve; The braking torque curve is determined according to the optimization objectives and constraints.

[0042] The deceleration curve is used to describe the changing relationship between vehicle speed and time during the braking process.

[0043] The pitch angular velocity curve is used to describe the changing relationship between the pitch angular velocity and time during the braking process of the vehicle.

[0044] The above optimization target is determined based on the peak and valley values of the pitch angular velocity curve.

[0045] The above constraints include a braking torque range, a braking distance range, and a stopping time determined based on a deceleration curve.

[0046] The braking torque range is used to indicate the adjustable range of the braking torque. The braking torque range includes the minimum braking torque and the maximum braking torque.

[0047] The braking distance range indicates the distance a vehicle travels from the start of braking until it comes to a complete stop. The braking distance range includes the minimum braking distance and the maximum braking torque.

[0048] The parking time indication controls the time information when the vehicle is parked based on the braking torque curve.

[0049] In some embodiments, the process of determining the constraint conditions required for generating the braking torque curve based on the deceleration curve may include: determining the constraint conditions based on the deceleration curve and environmental parameters of the vehicle's environment.

[0050] Among them, the environmental parameters include the road adhesion coefficient.

[0051] Based on this, the above constraints may also include a braking torque range, a braking distance range, and a stopping time determined based on the road adhesion coefficient and the deceleration curve.

[0052] In some embodiments, the above-mentioned process of predicting the deceleration curve and pitch angular velocity curve of the vehicle during braking may include: setting initial adjustment parameters for generating a braking torque curve based on the initial braking torque when the vehicle has a braking demand, the initial adjustment parameters including the initial braking torque, at least one braking torque that is located after the initial braking torque in the braking sequence, and switching control parameters between adjacent braking torques; based on the initial adjustment parameters, predicting the deceleration curve and pitch angular velocity curve of the vehicle during braking.

[0053] The initial braking torque refers to the braking torque determined when the vehicle has a braking demand.

[0054] For example, a braking torque curve includes a first braking torque and a second braking torque, and the braking order of the first braking torque precedes the braking order of the second braking torque. Based on this, the initial braking torque is the first braking torque. For another example, a braking torque curve includes three specified torques: braking torque A, braking torque B, and braking torque C. The braking order of braking torque A precedes the braking order of braking torque B, and the braking order of braking torque B precedes the braking order of braking torque C. Based on this, the initial braking torque is braking torque A.

[0055] The initial braking torque is determined based on the pedal depth of the vehicle and a corresponding relationship between a preset pedal depth and a preset braking torque.

[0056] The initial adjustment parameters refer to parameters set to adjust the braking torque curve in order to generate the braking torque curve.

[0057] Based on this, in some embodiments, the above-mentioned process of determining the braking torque curve according to the optimization objectives and constraints may include: constructing multiple candidate braking torque curves based on initial adjustment parameters, optimization objectives and constraints, wherein the adjustment parameters of different candidate braking torque curves are different; performing parameter optimization processing on the multiple candidate braking torque curves, and using the candidate braking torque curves obtained by optimization as the braking torque curve.

[0058] In order to facilitate the understanding of the above scheme, Figure 3 The braking torque curve shown is explained below using a specific embodiment.

[0059] like Figure 3 As shown, T b1is the initial braking torque, T b2 is the parking braking torque, t1 is the starting time of the braking torque reduction, t2 is the end time of the braking torque reduction, and t3 is the parking time. b1 Generally, it is determined by the depth of the driver's braking pedal. According to the above parameters, the initial adjustment parameters (T b1 , T b2 , t1, t2, t3).

[0060] After the initial adjustment parameters are set, the deceleration curve and pitch angular velocity curve of the vehicle during braking are predicted based on the initial adjustment parameters.

[0061] It should be noted that multiple candidate braking torque curves are constructed based on the initial adjustment parameters, optimization objectives, and constraints. Different candidate braking torque curves correspond to different adjustment parameters. For each candidate braking torque curve, the corresponding deceleration curve and pitch angular velocity curve during braking are predicted based on the adjustment parameters corresponding to that candidate braking torque curve.

[0062] The simulation results of the pitch angular velocity curves obtained by different candidate braking torque curves can be found in Figure 4 As shown. Figure 4 It was found that since the braking torque is affected by two sets of independent ground longitudinal force inputs, namely slope descent and vehicle parking, when the vehicle brakes, the pitch angular velocity curves predicted by different braking torque curves will show a phenomenon of superposition of peaks and troughs. Based on this phenomenon, the peak and valley values of the pitch angular velocity curve are used as optimization targets, and the increase in braking distance, parking time and minimum braking torque are used as constraints. Multiple candidate braking torque curves with different adjustment parameters can be designed for simulation, and the GA genetic algorithm is used to optimize the parameters from the multiple candidate braking torque curves. The optimal braking torque curve adjustment parameters can be solved, and the optimal braking torque curve is used as the braking torque curve for controlling the braking movement of the vehicle in the embodiment of the present application.

[0063] It should be noted that, from Figure 4 The simulation results of the pitch velocity curves shown show that using the candidate braking torque curves to control the vehicle's braking motion significantly reduces the pitch velocity oscillation amplitude during the parking phase compared to the traditional fixed braking torque curve, significantly enhancing pitch velocity compensation. Comparing the candidate braking torque curves, it was found that the optimal braking torque curve calculated using the genetic algorithm was candidate braking torque curve 1, which exhibited the best overall performance. Through the adjustment of this curve, both the peak and valley values of the pitch velocity during braking were reduced by over 60%, the pitch angle was also reduced by over 60%, and the braking distance increased by no more than 0.15m, effectively improving ride comfort.

[0064] In this way, compared to existing vehicle braking systems, where the braking torque rises to a fixed value after the driver presses the brake pedal until braking is complete, the longitudinal ground force is relatively large. This can increase the compression or extension of the front and rear suspension during parking, resulting in a large pitch shock and causing passenger discomfort. This application proposes a comfortable braking torque curve (i.e., the braking torque curve described in the embodiments of this application) that actively reduces the braking torque of the brake disc to a calculated value after the vehicle speed drops to a certain threshold. Based on this, not only can the longitudinal ground braking force during the braking-to-parking phase be reduced, lowering the pitch velocity amplitude of the parking shock, but a ramp excitation can also be introduced in advance to the vehicle body pitch system. This ramp excitation response and the parking pitch shock response complement each other and compensate for each other. With proper design, the maximum pitch velocity amplitude at the end of braking can be significantly reduced without excessively increasing the braking distance.

[0065] In some embodiments, the vehicle is configured with a braking analysis model.

[0066] The braking analysis model refers to a model used to analyze the braking motion process of a vehicle.

[0067] Based on this, the above-mentioned process of predicting the deceleration curve and pitch angular velocity curve of the vehicle during braking based on the initial adjustment parameters can include: through a braking analysis model, based on the initial adjustment parameters and the initial vehicle speed of the vehicle when there is a braking demand, predicting the vehicle speed information and pitch angular velocity information of the vehicle during braking; constructing a deceleration curve according to the multiple vehicle speeds in a sequence contained in the vehicle speed information; constructing a pitch angular velocity curve according to the multiple pitch angular velocities in a sequence contained in the pitch angular velocity information.

[0068] Specifically, the braking analysis model includes a tire model and a target dynamics model, wherein the target dynamics model is determined based on at least a vehicle dynamics model and a vehicle suspension model.

[0069] Based on this, the above-mentioned prediction of the vehicle speed information and pitch angular velocity information during the braking process through the braking analysis model, based on the initial adjustment parameters and the initial speed of the vehicle when there is a braking demand, includes: predicting the vehicle speed information and pitch angular velocity information during the braking process through the tire model and the target dynamics model, based on the initial adjustment parameters and the initial speed of the vehicle when there is a braking demand.

[0070] In some embodiments, the process of predicting the vehicle speed information during braking includes: determining the ground longitudinal force through a tire model based on the initial vehicle speed and initial adjustment parameters; updating the vehicle speed based on the ground longitudinal force and the correspondence between a preset tire ground longitudinal force and a preset vehicle speed; determining a new ground longitudinal force based on the updated vehicle speed and the initial adjustment parameters, and continuing to execute the step of updating the vehicle speed based on the ground longitudinal force and the correspondence between a preset tire ground longitudinal force and a preset vehicle speed to obtain vehicle speed information.

[0071] The process of determining the ground longitudinal force using the tire model based on the initial vehicle speed and initial adjustment parameters may include: predicting the braking torque corresponding to the initial vehicle speed based on the initial adjustment parameters; determining the slip rate based on the braking torque corresponding to the initial vehicle speed and the initial vehicle speed; and determining the ground longitudinal force based on the slip rate and wheel load information of the vehicle according to the tire magic formula.

[0072] The process of determining the slip ratio based on the braking torque corresponding to the initial vehicle speed and the initial vehicle speed may include: updating the wheel speed of the vehicle according to the braking torque corresponding to the initial vehicle speed; and determining the slip ratio according to the wheel speed and the initial vehicle speed.

[0073] In some embodiments, the process of predicting the pitch angular velocity information of a vehicle during braking includes: determining the pitch angle of the vehicle through a target dynamics model based on the ground longitudinal force determined by a tire model and the suspension information of the vehicle; updating the suspension information of the vehicle according to the pitch angle; updating the pitch angle of the vehicle based on the updated suspension information and the new ground longitudinal force determined by the tire model, and continuing to execute the step of updating the suspension information of the vehicle according to the pitch angle to determine the pitch angular velocity information based on the obtained pitch angle.

[0074] The vehicle's suspension information includes the vertical dynamic force of the vehicle's upper suspension and the vertical displacement of the vehicle's upper suspension.

[0075] In some embodiments, the process of updating the suspension information of the vehicle according to the pitch angle may include: updating the vertical displacement according to the pitch angle and the dynamic parameters of the vehicle; and updating the vertical dynamic force based on the updated vertical displacement.

[0076] In some embodiments, the above-mentioned braking control method also includes: generating an angular velocity error based on the pitch angular velocity, and generating a pitch angle error based on the pitch angle; and updating the vertical dynamic force of the suspension based on the pitch angle error and the angular velocity error through a target adjustment algorithm.

[0077] Among them, the target adjustment algorithm includes a fuzzy proportional-integral-differential control algorithm.

[0078] In some embodiments, the braking control method further includes: updating wheel load information of the vehicle based on the vertical dynamic force of the suspension, so that the tire model determines the ground longitudinal force based on the adjusted wheel load information.

[0079] In some embodiments, the target dynamics model further includes a terrain roughness model.

[0080] Based on this, the above-mentioned process of determining the pitch angle of the vehicle through the target dynamics model, the ground longitudinal force determined by the tire model, and the suspension information of the vehicle can include: determining the pitch angle of the vehicle through the target dynamics model, the ground longitudinal force determined by the tire model, the suspension information of the vehicle, and the target noise, wherein the target noise is obtained by analyzing the unevenness of the ground on which the vehicle is located based on the ground unevenness model.

[0081] In order to facilitate the understanding of the above scheme, Figure 5 The braking analysis model shown is explained below with a specific embodiment.

[0082] Specifically, the present application provides a braking analysis model, which is a body-suspension-tire coupling system, mainly including two parts, namely a tire model and a body-suspension model (i.e., the target dynamics model mentioned in the embodiments of the present application).

[0083] The tire model includes a Magic Tire Longitudinal Force Calculation Module 201, a Vehicle Speed Calculation Module 202, a Braking Torque Module 203, a Front Wheel Slip Ratio Calculation Module 204, and a Rear Wheel Slip Ratio Calculation Module 205. The vehicle speed output by the Vehicle Speed Calculation Module 202 and the braking torque output by the Braking Torque Module 203 are fed into the Front Wheel Slip Ratio Calculation Module 204 and the Rear Wheel Slip Ratio Calculation Module 205. The wheel speed is updated based on the current braking torque and subtracted from the vehicle speed to calculate the slip ratio. The slip ratio is then fed into the Magic Tire Longitudinal Force Calculation Module 201 to determine the actual tire ground longitudinal force. Finally, the ground longitudinal force is fed into the Vehicle Speed Calculation Module 202 to update the vehicle speed, forming a closed calculation loop.

[0084] The vehicle body-suspension model includes an active suspension displacement calculation module 206, an active suspension output force calculation module 207, a tire vertical acceleration calculation module 208, a fuzzy PID controller 209, and a pitch angular velocity calculation module 210. When the pitch angular velocity calculation module 210 receives the ground longitudinal force provided by the Magic Tire longitudinal force calculation module 201, the vehicle undergoes pitch motion. Changes in pitch angle cause the active suspension displacement calculation module 206 and the active suspension output force calculation module 207 to generate displacement and output force changes, respectively. These changes are then fed into the pitch angular velocity calculation module 210, forming a closed-loop system. Simultaneously, the active suspension output force calculation module 207 also causes changes in the vertical loads on the front and rear tires, which are then fed back into the Magic Tire calculation process via the tire vertical acceleration calculation module 208. To suppress vehicle body pitch motion, a fuzzy PID controller 209 is designed. This controller adjusts the suspension active force output in real time based on pitch angle and pitch angular velocity errors, reducing the vehicle's pitching impact. In addition to the above two parts, the system also has a ground roughness interference module 211 that provides a ground interference signal.

[0085] It should be noted that the braking analysis model of the present application adds the vehicle body longitudinal tilt center offset, tire elastic damping model, tire ground slip model, ground unevenness interference model and braking model on the basis of the existing dynamic model. When the vehicle brakes, the braking torque generates a ground longitudinal force through the tire model, and the ground longitudinal force has an inertial pitching moment on the vehicle body. Secondly, the ground unevenness interference is also transmitted to the vehicle body through the tire elastic damping model and the active suspension model in turn, and the pitching motion of the vehicle is generated by the combined action of the above factors. Previous analyses of braking analysis models have been too idealistic and failed to take into account the role of the vehicle body-suspension-tire coupling in actual working conditions, resulting in certain deviations in the analysis and calculation of the vehicle pitch angle and angular velocity. The supplemented dynamic model can comprehensively analyze the influence of the system's internal coupling, external interference and different driving conditions.

[0086] In some examples, such as Figure 6 As shown, the braking analysis model in this application is a half-active suspension vehicle dynamics model, which mainly includes front and rear tires, front and rear active suspensions, and body components. The physical meanings of the variables in the dynamics model are shown in Table 1. Since the comfort braking adjustment function is generally involved when braking is about to end and the vehicle speed is less than 2m / s, external resistances such as rolling resistance and wind resistance can be ignored during the analysis.

[0087] Table 1

[0088] Specifically, the motion equation of the vertical displacement of the vehicle body can be: The second derivative of the vertical displacement of the sprung mass * the vertical dynamic force of the vehicle body = the vertical dynamic force of the front suspension + the vertical dynamic force of the rear suspension, which is shown in the following formula (1-1), where is the vertical dynamic force of the front and rear suspension.

[0089] (1-1).

[0090] When the ground longitudinal force intervenes, the process of calculating the vertical dynamic force of the front and rear active suspension is as follows: Vertical dynamic force of the front suspension = - front suspension spring stiffness * (front suspension vertical displacement - front wheel vertical displacement) - front suspension damping coefficient * (first-order derivative of front suspension vertical displacement - first-order derivative of front wheel vertical displacement) + front suspension active force; The vertical dynamic force of the rear suspension = - rear suspension spring stiffness * (rear suspension vertical displacement - rear wheel vertical displacement) - rear suspension damping coefficient * (first-order derivative of rear suspension vertical displacement - first-order derivative of rear wheel vertical displacement) + rear suspension active force.

[0091] The specific formula is as shown in formula (1-2): (1-2).

[0092] It should be noted that in the present application, the ground longitudinal force is in the direction of vehicle braking as the positive direction, and the pitching moment is in the direction of vehicle nodding as the positive direction.

[0093] In addition, due to the pitch angle Smaller, combined Figure 1 And formula (1-2), the process of calculating the vertical displacement of the front and rear active suspension is: Front suspension vertical displacement = vehicle body vertical displacement - square root of [(front wheelbase + horizontal distance from center of mass to pitch center) squared + vertical distance from center of mass to pitch center) squared] * vehicle pitch angle + front wheel vertical displacement; Vertical displacement of rear suspension = vertical displacement of vehicle body + square root of [(rear wheelbase - horizontal distance from center of mass to longitudinal center) + square of vertical distance from center of mass to longitudinal center] * vehicle pitch angle + vertical displacement of rear wheel.

[0094] The specific formula is as shown in formula (1-3): (1-3).

[0095] It should be noted that in the horizontal direction, the motion equation of the ground longitudinal force acting on the entire vehicle can be: half vehicle mass * first-order derivative of vehicle speed = - (front wheel ground longitudinal force + rear wheel ground longitudinal force), and its specific formula (1-4) is shown as follows: (1-4).

[0096] Since the longitudinal ground force mainly comes from the friction resistance generated when the front and rear wheels slip against the ground during vehicle braking, the torque motion equation during wheel braking can be expressed as: Front wheel moment of inertia * first derivative of front wheel speed = front wheel ground longitudinal force * wheel effective radius - front wheel braking torque; Rear wheel moment of inertia * first derivative of rear wheel speed = rear wheel ground longitudinal force * wheel effective radius - rear wheel braking torque.

[0097] The specific formula is as shown in formula (1-5): (1-5) For the front and rear wheels, the vertical motion equation can be expressed as: Front wheel mass * second-order derivative of front wheel vertical displacement = - front tire spring stiffness * (front wheel vertical displacement - front ground vertical displacement) - front suspension damping coefficient * (first-order derivative of front wheel vertical displacement - first-order derivative of front ground vertical displacement) - front suspension vertical dynamic force; Rear wheel mass * second-order derivative of rear wheel vertical displacement = - rear tire spring stiffness * (rear wheel vertical displacement - rear ground vertical displacement) - rear suspension damping coefficient * (first-order derivative of rear wheel vertical displacement - first-order derivative of rear ground vertical displacement) - rear suspension vertical dynamic force.

[0098] The specific formula can be shown as follows: (1-6).

[0099] The vertical load between the front and rear tires and the ground in formula (1-6) consists of static vertical load and dynamic vertical load, which can be expressed as follows: Front wheel ground vertical force = rear wheelbase * half vehicle mass * g / (front wheelbase + rear wheelbase) - front suspension vertical dynamic force; Rear wheel ground vertical force = front wheelbase * half vehicle mass * g / (front wheelbase + rear wheelbase) - rear suspension vertical dynamic force; Front suspension vertical dynamic force = front tire spring stiffness * (front wheel vertical displacement - front ground vertical displacement) + front tire damping coefficient * (first-order derivative of front wheel vertical displacement - first-order derivative of front ground vertical displacement) + front suspension active force; Rear suspension vertical dynamic force = rear tire spring stiffness * (rear wheel vertical displacement - rear ground vertical displacement) + rear tire damping coefficient * (first-order derivative of rear wheel vertical displacement - first-order derivative of rear ground vertical displacement) + rear suspension active force; The specific formula is as shown in formula (1-7):

[0100] (1-7).

[0101] Furthermore, according to the parallel axis theorem, the moment of inertia of the pitch center can be expressed as: The moment of inertia at the pitch center = the moment of inertia of the vehicle body's center of mass + the sprung mass * the square of the horizontal distance from the center of mass to the pitch center + the square of the vertical distance from the center of mass to the pitch center).

[0102] The specific formula is as shown in formula (1-8): (1-8).

[0103] Based on the above formula, the overall vehicle pitch motion equation can be determined. This equation can be expressed as: pitch center moment of inertia * second-order derivative of vehicle pitch angle = - front suspension vertical dynamic force * (front wheelbase + horizontal distance from center of mass to pitch center) + rear suspension vertical dynamic force * (rear wheelbase - horizontal distance from center of mass to pitch center) + front wheel ground longitudinal force * front wheel longitudinal moment arm + rear wheel ground longitudinal force * rear wheel longitudinal moment arm. Specifically, this equation is shown in Formula (1-9): (1-9).

[0104] Among them, the longitudinal force arm The solution is: front wheel longitudinal moment arm = center of mass height - vertical distance from center of mass to pitch center + body vertical displacement - front suspension vertical displacement; rear wheel longitudinal moment arm = center of mass height - vertical distance from center of mass to pitch center + body vertical displacement - rear suspension vertical displacement, which can be specifically shown according to the following formula (1-10): (1-10).

[0105] The vertical displacement of the ground is , that is, the uneven ground interference will affect the height of the longitudinal force acting on the wheel.

[0106] During braking, the front and rear wheel slip rates are calculated as follows: front wheel slip rate = (real-time vehicle speed - front wheel speed * wheel effective radius) / real-time vehicle speed; rear wheel slip rate = (real-time vehicle speed - rear wheel speed * wheel effective radius) / real-time vehicle speed. Specifically, they can be calculated as shown in the following formula (1-11): (1-11).

[0107] For the tire model and ground interference model, this application can use the classic magic tire formula to solve the ground longitudinal force. Among them, the magic tire formula calculates the ground longitudinal force of the tire As shown in formula (1-12): (1-12).

[0108] in, is the stiffness factor, is the shape factor, is the peak factor, is the curvature factor.

[0109] Specifically, the stiffness factor, shape factor, peak factor, and curvature factor are calculated as shown in formula (1-13): (1-13).

[0110] in, is the vertical load of the tire, that is, , It should be noted that the road surface roughness characteristic description standard for the vehicle vibration system input is the road surface power spectrum density , which can be expressed as follows: (1-14).

[0111] in, The ground reference spatial frequency is generally taken as 0.1 m -1 , is the power spectrum density of road roughness at the reference spatial frequency, It is the frequency index in different frequency ranges, generally a piecewise function.

[0112] Furthermore, the time domain excitation equation caused by ground roughness can be simulated according to the following formula (1-15): (1-15).

[0113] in, is the road surface roughness displacement input, that is, , is the spatial frequency of the selected road surface, is the vehicle speed, is a white noise function.

[0114] Based on the above formula (1-15), the rational function fitting is performed to obtain the following formula (1-16), and the model parameters are obtained based on the multi-level road surface simulation analysis .

[0115] (1-16) Among them, the road surface roughness is mainly divided into A, B and C levels. In order to correspond to the road surface classification, C level road surface is generally selected. Perform simulation and take sampling time as 10 ms , the noise power is set to 0.01m 2 , then the ground roughness noise interference input is as follows Figure 7 shown.

[0116] Based on the above, see Figure 8 The braking control process of a specific embodiment of the braking control method of the present application is as follows: Initially, the vehicle is traveling at a constant speed. When the driver is detected pressing the brake pedal, the comfort braking function is officially triggered, and the initial ground longitudinal force before braking is set to 0. The initial wheel speed is obtained by dividing the real-time vehicle speed estimated by the IMU status by the effective wheel radius. The wheel angular acceleration is calculated using formula (1-5) based on the braking torque measured by the wheel cylinder pressure sensor. The wheel speed is updated after time integration. The slip ratio is calculated by subtracting the real-time vehicle speed signal using formula (1-11). The calculated slip ratio is input into the magic tire longitudinal force calculation module 201, and the actual ground longitudinal force is solved using formula (1-12). The result is substituted into formula (1-5) to iteratively calculate and update the wheel speed. The ground longitudinal force and wheel hop are input into the pitch angular velocity calculation module 210. Because the ground longitudinal force generates a pitch moment on the pitch center, the vehicle body will produce a pitching motion with oscillation and damping due to the damping characteristics of the suspension. By coupling equations (1-4) and (1-9) with the suspension system and integrating the instantaneous pitch acceleration, the pitch velocity, angle curve, and deceleration curve generated by braking can be predicted. The predicted pitch velocity and pitch angle are subtracted from zero as two-dimensional error variables and input into the fuzzy PID controller 209 for feedback calculation. The active force request value of the suspension required to suppress the pitch motion of the suspension is calculated through the fuzzy control rule table, and the peak value of the pitch velocity is reduced to reduce the impact. Based on the predicted deceleration curve and pitch velocity curve, the peak and valley values of the pitch velocity curve are used as the fitness function, and the braking distance, parking time, and minimum braking torque are used as constraints. The shape adjustment parameters of the braking torque curve are optimized through the GA genetic algorithm, so as to calculate the following: Figure 3 The optimal braking torque curve is determined by the algorithm. At the end of braking, the wheel braking torque is actively reduced until the vehicle comes to a complete stop, disabling the comfort braking function. The maximum braking torque and braking risk, provided the vehicle is not locked, vary for surfaces with varying road adhesion coefficients. Therefore, the genetic algorithm's internal constraints are adjusted based on the road adhesion coefficient. This approach aims to effectively reduce the maximum amplitude of the pitch angular velocity during braking while ensuring braking safety, thereby improving passenger comfort and preventing motion sickness.

[0117] In this way, the system can automatically adjust the shape of the comfort braking torque curve under different braking intensities and road adhesion coefficients to achieve optimal compensation for the vehicle body's pitch angular velocity, improving driving comfort. In addition, the impact on braking distance is also analyzed.

[0118] Specifically, a fuzzy PID controller based on active suspension is designed to regulate pitch motion. The vehicle's pitch angle error, e, and angular velocity error, ec, are used as input signals. A fuzzy domain is selected based on the uncontrolled pitch angle and angular velocity errors during braking, and the input and output signals are integrated into the domain through normalization. A subset of seven fuzzy linguistic variables, {NB, NM, NS, ZO, PS, PM, PB}, is selected and fuzzified using Gaussian membership functions. The controller outputs serve as the control variables for the PID control unit: the proportional variable Δkp, the integral variable Δki, and the differential variable Δkd, respectively. A fuzzy rule table is developed to determine the relationship between the fuzzy input and output signals. Defuzzification is then used to obtain the PID control variable corresponding to the current input signal. This control variable is summed with the initial PID parameters to update the control unit, achieving adaptive PID control of the system.

[0119] Before simulation Figure 6 The vehicle dynamics model of the active suspension is configured with parameters such as mass, wheelbase, spring stiffness, and damping. Figure 9 The figure shows an initial braking torque embodiment of the present invention. After 3 seconds of constant speed driving, the brake pedal is pressed and the braking torque reaches its maximum at 4 seconds. The front and rear wheel braking torque distribution coefficient is 0.5. Considering the actual suspension performance limitations, it is necessary to set the maximum adjustable force range that the active suspension can output. The active suspension is simulated using no control, PID controller, and fuzzy PID controller. The obtained pitch angular velocity simulation results are shown in Figure 1. Figure 10 As shown in the figure, controlling the active suspension using an adaptive fuzzy-PID algorithm can reduce both the peak and valley pitch velocity at the end of braking, outperforming a PID controller and without affecting braking distance. This method improves vehicle ride comfort without compromising braking performance. However, because the active suspension's adjustment range is affected by factors such as cost and structure, its ability to mitigate braking pitch impact is limited.

[0120] Furthermore, a combined control method for vehicle braking comfort was designed by integrating the above fuzzy PID suspension controller and the comfort braking torque curve. The body-suspension-tire coupling model was simulated without pitch motion adjustment, using only the active suspension fuzzy PID controller, using only the comfort braking torque curve, and using both the active suspension fuzzy PID controller and the comfort braking torque curve. The obtained pitch angular velocity comparisons were as follows: Figure 11 It can be observed that under the combined regulation strategy, the vehicle pitch angular velocity during the braking phase is reduced by 74% compared to the original peak value, and the valley value is reduced by 63%.

[0121] Thus, a fuzzy PID controller was designed, using the pitch velocity error and pitch angle error during vehicle braking as inputs. The controller then controlled the suspension damping current in real time to adjust the vehicle's pitch velocity using feedback. Simulated pitch velocity curves before and after the fuzzy PID controller were compared under different braking conditions. The results show that compared to conventional PID controllers, the fuzzy PID controller reduced both the pitch velocity amplitude and pitch angle overshoot during braking. Compared to other algorithms, this algorithm offers low resource consumption and high robustness, making it suitable for practical vehicle applications.

[0122] Based on this, this application proposes a vehicle comfort braking strategy for different road adhesion coefficients, such as Figure 12 As shown in the figure, first, sensors are used to collect vehicle driving information. The sensor system mainly includes a center of mass accelerometer, a center of mass gyroscope, a wheel speed sensor, a brake pedal depth sensor, and a lidar ranging unit. The collected data is collected in a central domain processor for filtering and state estimation. The road adhesion coefficient of each wheel, slip rate, vehicle speed, brake pedal braking force, distance to the obstacle in front and other signals are calculated. Based on this signal, the working logic of the vehicle's comfort braking function is determined.

[0123] In some embodiments, when the vehicle has a braking demand, the process of obtaining the braking torque curve may include: obtaining the braking torque curve when the vehicle has a braking demand and the environment in which the vehicle is located meets a safety environment condition.

[0124] Among them, the safety environment conditions are determined based on the road adhesion coefficient of the vehicle's environment.

[0125] In other embodiments, the above-mentioned braking control method may further include: when the vehicle has a braking demand and the environment in which the vehicle is located does not meet the safety environment conditions, controlling the braking movement of the vehicle based on the initial braking torque when the vehicle has a braking demand.

[0126] Specifically, the vehicle's comfort braking combination control strategy actively reduces wheel braking torque at the end of braking, slightly increasing the final stopping distance and weakening the vehicle's braking performance. Therefore, this comfort braking function must be used while ensuring driving safety. It is only suitable for routine braking conditions in daily traffic and should not be triggered under extreme braking conditions. For example, during braking, the function will automatically deactivate if the ABS function requires anti-lock braking or the AEB function requires emergency braking for collision avoidance.

[0127] In addition, due to the different adhesion coefficients of each wheel during vehicle driving, the vehicle will also pass through opposing roads or connecting roads. In order to maintain the vehicle's driving stability, the comfort braking function will be interrupted when the stability function of the opposing roads or connecting roads is turned on, and the comfort braking function will be restarted after the road surface is restored.

[0128] The comfortable braking function on a uniform road surface should change the braking combination adjustment strategy according to the different road adhesion coefficients. Road surfaces with different adhesion coefficients have a significant impact on the effective adjustment range of the braking torque. Considering that the braking distance on low-adhesion surfaces such as ice and snow is generally longer than that on high-adhesion surfaces, the braking safety risk is high and the accident rate is high, it is not appropriate to increase the braking distance. Therefore, the algorithm provided in this application does not adjust the braking torque curve on ice and snow surfaces with a road adhesion coefficient of less than 0.3. On wet and dusty roads with a road adhesion coefficient greater than 0.3 and less than 0.6, the braking distance calculated based on the initial braking torque and road adhesion coefficient will serve as a boundary constraint condition for the genetic optimization of the braking torque curve, and the braking torque adjustment range needs to be narrowed. On dry concrete and asphalt roads with a road adhesion coefficient greater than 0.6, the braking torque adjustment capability is fully opened. The combined adjustment strategy for vehicle braking pitch comfort with different road adhesion coefficients proposed in this application can significantly optimize driving comfort while ensuring driving safety.

[0129] Thus, the Comfort Braking function was designed by combining the advantages of active suspension and braking torque curves to jointly suppress vehicle pitch shock during braking. This Comfort Braking function is generally used in daily driving braking conditions and takes into account the interaction of a series of functions such as ABS, AEB, and ADAS. The Comfort Braking Torque Curve will increase braking distance to a certain extent. Considering driving safety, an intelligent chassis Comfort Braking control strategy that can dynamically adjust to different road adhesion coefficients is proposed to effectively improve driving comfort.

[0130] The present application also provides a controller, such as Figure 13 , which shows a schematic diagram of the structure of the controller involved in the embodiment of the present application, specifically: The controller may include one or more processing core processors 301, one or more storage media memories 302, a power supply 303, an input unit 304 and other components. Those skilled in the art will understand that Figure 13 The controller structure shown in the figure does not constitute a limitation on the controller, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently. Processor 301 is the controller's control center, connecting all components of the controller using various interfaces and circuits. It executes computer programs and / or modules stored in memory 302 and accesses data stored in memory 302 to perform various controller functions and process data. Optionally, processor 301 may include one or more processing cores. Preferably, processor 301 integrates an application processor and a modem processor. The application processor primarily handles the operating system, user interface, and application programs, while the modem processor primarily handles wireless communications. It is understood that the modem processor may not be integrated into processor 301.

[0131] Memory 302 can be used to store computer programs and modules. Processor 301 executes various functional applications and brake control by running the computer programs and modules stored in memory 302. Memory 302 may primarily include a program storage area and a data storage area. The program storage area may store an operating system and computer programs required for at least one function (such as audio and visual prompts, brake control, etc.); the data storage area may store data generated based on controller usage. Memory 302 may also include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device. Accordingly, memory 302 may also include a memory controller to provide processor 301 with access to memory 302.

[0132] The controller also includes a power supply 303 for supplying power to various components. Preferably, the power supply 303 can be logically connected to the processor 301 via a power management system, thereby enabling the power management system to manage charging, discharging, and power consumption. The power supply 303 can also include one or more DC or AC power supplies, a recharging system, a power failure detection circuit, a power converter or inverter, a power status indicator, and other arbitrary components.

[0133] The controller may further include an input unit 304, which may be configured to receive input digital or character information and generate keyboard, mouse, joystick, optical or trackball signal inputs related to user settings and function control.

[0134] Although not shown, the controller may further include a display unit, etc., which will not be described in detail here. Specifically, in this embodiment, the processor 301 in the controller will load the executable files corresponding to one or more computer program processes into the memory 302 according to the following instructions, and the processor 301 will run the computer programs stored in the memory 302 to implement various functions, such as: When the vehicle has a braking demand, a braking torque curve is obtained, wherein the braking torque curve includes at least two braking torques having a braking sequence and a switching control parameter of adjacent braking torques, and a braking torque in a later braking sequence is smaller than a braking torque in an earlier braking sequence; Based on the braking torque in the braking torque curve and the switching control parameter, the braking movement of the vehicle is controlled.

[0135] As can be seen, the controller provided in an embodiment of the present application obtains a braking torque curve when the vehicle has a braking demand. The braking torque curve includes at least two braking torques with a braking sequence and switching control parameters for adjacent braking torques, where the braking torque in the later braking sequence is less than the braking torque in the earlier braking sequence. The controller controls the braking motion of the vehicle based on the braking torque and switching control parameters in the braking torque curve. Based on this, by using a braking torque curve containing multiple braking torques of different magnitudes and braking sequences to control the braking motion of the vehicle, the user experience is improved by reducing the braking torque to smooth the pitch impact of the vehicle during parking.

[0136] The specific implementation methods and corresponding beneficial effects of the above operations can be found in the detailed description of the braking control method above, which will not be elaborated here.

[0137] Those skilled in the art will appreciate that all or part of the steps in the various methods of the above embodiments may be accomplished by a computer program, or by controlling related hardware through a computer program. The computer program may be stored in a storage medium and loaded and executed by a processor.

[0138] To this end, an embodiment of the present application provides a storage medium storing a computer program that can be loaded by a processor to execute the steps of any of the braking control methods provided in the embodiments of the present application. For example, the computer program can execute the following steps: When the vehicle has a braking demand, a braking torque curve is obtained, wherein the braking torque curve includes at least two braking torques having a braking sequence and a switching control parameter of adjacent braking torques, and a braking torque in a later braking sequence is smaller than a braking torque in an earlier braking sequence; Based on the braking torque in the braking torque curve and the switching control parameter, the braking movement of the vehicle is controlled.

[0139] As can be seen, the storage medium provided in an embodiment of the present application obtains a braking torque curve when a vehicle has a braking demand, wherein the braking torque curve includes at least two braking torques with a braking sequence and switching control parameters for adjacent braking torques, and the braking torque of the later braking sequence is less than the braking torque of the earlier braking sequence; and controls the braking movement of the vehicle based on the braking torque and switching control parameters in the braking torque curve. Based on this, by using a braking torque curve containing multiple braking torques of different sizes and different braking sequences to control the braking movement of the vehicle, the user experience is improved by reducing the braking torque to smooth the pitch impact of the vehicle during parking.

[0140] The specific implementation methods and corresponding beneficial effects of the above operations can be found in the previous embodiments and will not be described in detail here.

[0141] The storage medium may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0142] Since the computer program stored in the storage medium can execute the steps of any braking control method provided in the embodiments of the present application, the beneficial effects that can be achieved by any braking control method provided in the embodiments of the present application can be achieved. Please refer to the previous embodiments for details and will not be repeated here.

[0143] According to one aspect of the present application, a computer program product or computer program is provided, the computer program product or computer program including computer instructions stored in a storage medium. A processor of a computer device reads the computer instructions from the storage medium and executes the computer instructions, causing the computer device to perform the above-described braking control method.

[0144] An embodiment of the present application also provides a vehicle, which includes the above-mentioned controller or the above-mentioned computer program product.

[0145] Exemplarily, the vehicle includes the aforementioned controller. When the vehicle has a braking demand, the controller obtains a braking torque curve, wherein the braking torque curve includes at least two braking torques in a braking sequence and switching control parameters for adjacent braking torques, with the braking torque for a later braking torque being less than the braking torque for an earlier braking torque. The vehicle's braking motion is controlled based on the braking torques and switching control parameters in the braking torque curve. By utilizing a braking torque curve containing multiple braking torques of varying magnitudes and in different braking sequences, the vehicle's braking motion is controlled, thereby reducing the braking torque to mitigate the vehicle's pitching shock during parking and improving the user experience.

[0146] The specific structure of the vehicle is not limited in this application. The specific implementation methods and corresponding beneficial effects of the above operations of the control device are also applicable to the vehicle. For details, please refer to the detailed description of the vehicle control method above, which will not be repeated here.

[0147] The above is a detailed introduction to a braking control method, controller, storage medium, computer program product and vehicle provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A braking control method, characterized in that: The method comprises: When the vehicle has a braking demand, a braking torque curve is obtained, wherein the braking torque curve includes at least two braking torques having a braking sequence and a switching control parameter of adjacent braking torques, and a braking torque in a later braking sequence is smaller than a braking torque in an earlier braking sequence; Based on the braking torque in the braking torque curve and the switching control parameter, a braking movement of the vehicle is controlled.

2. The braking control method according to claim 1, characterized in that: The switching control parameter includes a switching start condition, the braking torque curve includes a first braking torque and a second braking torque, and the braking order of the first braking torque is located before the braking order of the second braking torque; The controlling the braking movement of the vehicle based on the braking torque in the braking torque curve and the switching control parameter includes: controlling a braking movement of the vehicle based on the first braking torque; When the switching start condition is met, the first braking torque is switched to the second braking torque based on the switching control parameter to continue controlling the braking movement of the vehicle.

3. The braking control method according to claim 2, characterized in that: The switching start condition includes that the vehicle speed decreases to a preset vehicle speed, and / or the braking moment of the braking movement of the vehicle controlled based on the braking torque reaches a torque reduction start moment.

4. The braking control method according to claim 2, wherein: The switching control parameter further includes a torque decreasing speed, and the controlling the switching of the first braking torque to the second braking torque based on the switching control parameter to continue controlling the braking movement of the vehicle includes: controlling, according to the torque reduction speed, to reduce the braking torque of the vehicle from the first braking torque to the second braking torque; Based on the second braking torque, the braking movement of the vehicle continues to be controlled.

5. The braking control method according to claim 4, characterized in that: The switching control parameter also includes a torque reduction end time, which is used to indicate an end time for reducing the braking torque of the vehicle. At the torque reduction end time, the braking torque of the vehicle is the second braking torque.

6. The brake control method according to claim 1, characterized in that: The step of obtaining a braking torque curve when the vehicle has a braking demand includes: When the vehicle has a braking demand, predicting a deceleration curve and a pitch angular velocity curve of the vehicle during braking; determining an optimization target required for generating a braking torque curve based on the pitch angular velocity curve, and determining a constraint condition required for generating the braking torque curve based on the deceleration curve; A braking torque curve is determined according to the optimization objective and the constraint conditions.

7. The brake control method according to claim 6, characterized in that: The optimization target is determined based on peak values and valley values of the pitch rate curve.

8. The braking control method according to claim 6, characterized in that: Determining the constraint conditions required for generating the braking torque curve based on the deceleration curve includes: The constraint condition is determined according to the deceleration curve and environmental parameters of the environment in which the vehicle is located.

9. The brake control method according to claim 8, characterized in that: The environmental parameters include a road adhesion coefficient, and the constraint conditions include a braking torque range, a braking distance range, and a stopping time determined based on the road adhesion coefficient and the deceleration curve.

10. The brake control method according to claim 6, characterized in that: The predicting of a deceleration curve and a pitch angular velocity curve of the vehicle during braking includes: setting initial adjustment parameters for generating a braking torque curve according to an initial braking torque when the vehicle has a braking demand, the initial adjustment parameters including the initial braking torque, at least one braking torque subsequent to the initial braking torque in a braking sequence, and a switching control parameter between adjacent braking torques; Based on the initial adjustment parameters, a deceleration curve and a pitch angular velocity curve of the vehicle during braking are predicted.

11. The brake control method according to claim 10, characterized in that: The initial braking torque is determined based on a pedal depth of the vehicle and a corresponding relationship between a preset pedal depth and a preset braking torque.

12. The brake control method according to claim 10, characterized in that: Determining the braking torque curve according to the optimization objective and the constraint conditions includes: constructing a plurality of candidate braking torque curves based on the initial adjustment parameters, the optimization target, and the constraint conditions, wherein the adjustment parameters of different candidate braking torque curves are different; Parameter optimization processing is performed on the plurality of candidate braking torque curves, and the candidate braking torque curve obtained by the optimization is used as the braking torque curve.

13. The brake control method according to claim 10, characterized in that: The vehicle is equipped with a braking analysis model, and the deceleration curve and pitch angular velocity curve of the vehicle during braking are predicted based on the initial adjustment parameters, including: Predicting, by the braking analysis model, vehicle speed information and pitch angular velocity information of the vehicle during braking based on the initial adjustment parameters and the initial vehicle speed of the vehicle when braking is required; constructing the deceleration curve according to a plurality of vehicle speeds in a sequential order included in the vehicle speed information; The pitch angular velocity curve is constructed according to a plurality of pitch angular velocities in a sequential order included in the pitch angular velocity information.

14. The brake control method according to claim 13, characterized in that: The braking analysis model includes a tire model, and the process of predicting the vehicle speed information during braking includes: Determining a ground longitudinal force based on the tire model and the initial vehicle speed and the initial adjustment parameters; updating the vehicle speed based on the ground longitudinal force and a preset correspondence between the tire ground longitudinal force and a preset vehicle speed; Based on the updated vehicle speed and the initial adjustment parameters, a new ground longitudinal force is determined, and the step of updating the vehicle speed based on the ground longitudinal force and the corresponding relationship between the preset tire ground longitudinal force and the preset vehicle speed is continued to obtain the vehicle speed information.

15. The brake control method according to claim 14, characterized in that: Determining the ground longitudinal force based on the initial vehicle speed and the initial adjustment parameters using the tire model includes: predicting a braking torque corresponding to the initial vehicle speed based on the initial adjustment parameters; determining a slip ratio based on a braking torque corresponding to the initial vehicle speed and the initial vehicle speed; The ground longitudinal force is determined based on the slip ratio and wheel load information of the vehicle according to a tire magic formula.

16. The brake control method according to claim 15, characterized in that: The determining of the slip ratio based on the braking torque corresponding to the initial vehicle speed and the initial vehicle speed includes: updating the wheel speed of the vehicle according to the braking torque corresponding to the initial vehicle speed; A slip ratio is determined based on the wheel speed and the initial vehicle speed.

17. The brake control method according to claim 14, characterized in that: The braking analysis model includes a target dynamics model determined based on at least a dynamics model of the vehicle and a suspension model of the vehicle.

18. The brake control method according to claim 17, wherein: The process of predicting the pitch angular velocity information of the vehicle during braking includes: determining, by the target dynamics model, a pitch angle of the vehicle based on the ground longitudinal force determined by the tire model and suspension information of the vehicle; updating suspension information of the vehicle according to the pitch angle; Based on the updated suspension information and the new ground longitudinal force determined by the tire model, the pitch angle of the vehicle is updated, and the step of updating the suspension information of the vehicle according to the pitch angle is continued to determine the pitch angular velocity information based on the obtained pitch angle.

19. The brake control method according to claim 18, characterized in that: The suspension information of the vehicle includes the vertical dynamic force of the suspension on the vehicle and the vertical displacement of the suspension on the vehicle.

20. The brake control method according to claim 19, wherein: The updating of the suspension information of the vehicle according to the pitch angle includes: updating the vertical displacement according to the pitch angle and the dynamic parameters of the vehicle; The vertical dynamic force is updated based on the updated vertical displacement.

21. The brake control method according to claim 19, wherein: The method further comprises: generating an angular velocity error based on the pitch angular velocity, and generating a pitch angle error based on the pitch angle; The vertical dynamic force of the suspension is updated based on the pitch angle error and the angular velocity error through a target adjustment algorithm.

22. The brake control method according to claim 21, characterized in that: The target adjustment algorithm includes a fuzzy proportional-integral-derivative control algorithm.

23. The brake control method according to claim 19, characterized in that: The method further comprises: Based on the vertical dynamic force of the suspension, wheel load information of the vehicle is updated so that the tire model determines the ground longitudinal force based on the adjusted wheel load information.

24. The brake control method according to claim 18, wherein: The target dynamics model further includes a ground roughness model. Determining the pitch angle of the vehicle by using the target dynamics model based on the ground longitudinal force determined by the tire model and suspension information of the vehicle includes: The pitch angle of the vehicle is determined by the target dynamics model based on the ground longitudinal force determined by the tire model, the suspension information of the vehicle, and target noise, wherein the target noise is obtained by analyzing the unevenness of the ground on which the vehicle is located based on the ground unevenness model.

25. The brake control method according to any one of claims 1 to 24, characterized in that: The step of obtaining a braking torque curve when the vehicle has a braking demand includes: When the vehicle has a braking demand and the environment in which the vehicle is located meets a safety environment condition, a braking torque curve is obtained.

26. The brake control method according to claim 25, characterized in that: The safety environment condition is determined based on a road adhesion coefficient of an environment in which the vehicle is located.

27. The brake control method according to claim 25, characterized in that: The method further comprises: When the vehicle has a braking demand and the environment in which the vehicle is located does not meet a safety environment condition, the braking movement of the vehicle is controlled based on an initial braking torque when the vehicle has a braking demand.

28. A controller, characterized in that: The invention comprises one or more processors and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor is caused to perform the steps of the brake control method according to any one of claims 1 to 27.

29. A storage medium, characterized in that The invention comprises a computer program, which is used to cause the controller to execute the steps of the brake control method according to any one of claims 1 to 27 when the computer program is run on the controller.

30. A computer program product, characterized in that The method comprises a computer program or instructions, which implements the steps of the braking control method according to any one of claims 1 to 27 when the computer program or instructions are executed by a processor.

31. A vehicle, characterized in that: The vehicle includes the controller of claim 28.

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