Vehicle composite braking control method, device, equipment and storage medium

Abstract

The application discloses a control method, device and equipment of vehicle composite braking and a storage medium, and the method comprises the following steps: identifying braking information required by a user and road surface information of a road where a vehicle is currently located, and receiving steering information of each steering wheel of the vehicle; analyzing and processing the braking information, the road surface information and the steering information to determine a braking mode of the vehicle; and obtaining a pressure ratio provided by different braking sources of the vehicle and a braking pressure ratio provided by the braking sources to different drive wheels of the vehicle based on the braking mode and in combination with the braking information, so as to control the composite braking of the vehicle. According to the application, the braking mode is automatically selected based on the braking information, the road surface information and the steering information, and the braking pressure ratio of the braking sources and the braking pressure provided by the braking sources to different drive wheels are reasonably distributed, so that the stability of the electric vehicle and the energy recovery efficiency of the braking motor can be considered at the same time, and the stability of the electric vehicle and the energy recovery efficiency of the braking motor are improved.

Description

Technical Field

[0001] This application relates to the field of vehicle braking, and more particularly to a control method, device, equipment, and storage medium for vehicle composite braking. Background Technology

[0002] As people become more environmentally conscious, electric vehicles are becoming increasingly popular. Electric vehicles can not only reduce energy consumption, but also recover energy through compound braking.

[0003] Hybrid braking is a technology unique to electric vehicles. It converts the kinetic energy of a vehicle during driving into electrical energy, which is then stored in the battery, increasing the driving range. Currently, an increasing number of electric vehicles are adopting hybrid braking. However, because hybrid braking requires the participation of a brake motor to regulate braking pressure, it cannot simultaneously ensure both the stability of the electric vehicle and the efficiency of energy recovery by the brake motor, resulting in low stability for both the electric vehicle and low efficiency in energy recovery by the brake motor. Summary of the Invention

[0004] The main objective of this application is to provide a control method, device, equipment, and storage medium for vehicle composite braking, aiming to solve the technical problems of low stability of electric vehicles and low efficiency of energy recovery by brake motors in the prior art.

[0005] To achieve the above objectives, this application provides a control method for vehicle compound braking, the control method comprising:

[0006] It identifies the braking information required by the user and the road surface information of the current road where the vehicle is located, and receives the steering information of each steering wheel of the vehicle.

[0007] The braking information, road surface information, and steering information are analyzed and processed to determine the braking mode of the vehicle;

[0008] Based on the braking mode and combined with the braking information, the pressure ratio provided by different braking sources of the vehicle and the ratio of braking pressure provided by the braking sources to different drive wheels of the vehicle are obtained, so as to control the compound braking of the vehicle.

[0009] Optionally, the braking mode includes compound braking;

[0010] The step of obtaining the pressure ratio provided by different braking sources of the vehicle and the ratio of braking pressure provided by the braking sources to different drive wheels of the vehicle based on the braking mode and in combination with the braking information includes:

[0011] If the braking mode is a compound braking, the braking signal is analyzed to obtain the braking intensity, and based on the braking intensity, the pressure ratio provided by the braking source is determined.

[0012] The braking intensity is matched with a preset I-curve to determine the ratio of braking pressure provided by the braking source to different drive wheels.

[0013] Optionally, the step of analyzing and processing the braking information, the road surface information, and the steering information to determine the vehicle's braking mode includes:

[0014] The braking information is analyzed to determine the braking intensity required by the user, and the braking intensity is used to perform power calculation to obtain the total braking force required by the user.

[0015] The road surface information is analyzed to determine the peak adhesion coefficient of the road surface where the vehicle is currently located;

[0016] Based on a preset positive direction, the steering information is analyzed to determine the steering angle of the steering wheel;

[0017] The braking mode of the vehicle is determined by comprehensively judging the total braking force, the peak adhesion coefficient, the steering angle, and preset judgment conditions.

[0018] Optionally, the step of analyzing the road surface information to determine the peak adhesion coefficient of the road surface where the vehicle is currently located includes:

[0019] The current road surface information is analyzed to determine the vehicle's slip ratio and adhesion coefficient.

[0020] The slip ratio and the adhesion coefficient are analyzed to determine the road surface curve of the current road surface;

[0021] The peak adhesion coefficient of the road surface where the vehicle is currently located is determined by comparing the road surface curve with a preset reference road surface curve.

[0022] Optionally, the step of analyzing the braking information to determine the braking intensity required by the user, and performing a power calculation on the braking intensity to obtain the total braking force required by the user, includes:

[0023] The braking information is analyzed to determine the displacement signal and displacement rate of the vehicle's brake pedal.

[0024] Based on the displacement change rate and the displacement signal, the user's braking intention is determined;

[0025] Based on the braking intention, determine the braking intensity required by the user;

[0026] The braking intensity is calculated and analyzed to determine the braking force required for each wheel of the vehicle;

[0027] The braking force required for each wheel is compiled and summarized to obtain the total braking force required by the user.

[0028] Optionally, the step of comprehensively judging the total braking force, the peak adhesion coefficient, the steering angle, and preset judgment conditions to determine the braking mode of the vehicle includes:

[0029] The peak adhesion coefficient is used to perform dynamic calculations to determine the ground braking force of the road surface on the vehicle;

[0030] When the steering angle is greater than zero, the total braking force and the ground braking force are judged to obtain the judgment result;

[0031] Based on the judgment result, the braking mode of the vehicle is determined.

[0032] Optionally, the vehicle compound braking control method further includes:

[0033] When the current road condition is a split road surface, determine the split adhesion coefficient of each wheel of the vehicle on the split road surface;

[0034] Determine the distribution of braking force to the wheel on the side with the minimum coefficient of adhesion;

[0035] The distributed braking force is matched with a preset I curve to determine the ratio of braking pressure provided by different drive wheels of the braking source on the split road surface.

[0036] This application also provides a control device for vehicle compound braking, the control device for vehicle compound braking comprising:

[0037] The identification module is used to identify the braking information requested by the user and the road surface information of the road where the vehicle is currently located, and to receive the steering information of each steering wheel of the vehicle.

[0038] The first analysis module is used to analyze and process the braking information, the road surface information, and the steering information to determine the braking mode of the vehicle.

[0039] The first determining module is used to determine, based on the braking mode and in conjunction with the braking information, the pressure ratio provided by different braking sources of the vehicle and the ratio of braking pressure provided by the braking sources to different drive wheels of the vehicle, so as to control the compound braking of the vehicle.

[0040] Optionally, the braking mode includes conventional braking and combined braking;

[0041] The first determining module includes:

[0042] The first analysis submodule is used to analyze the braking signal to obtain the braking intensity if the braking mode is compound braking, and to determine the pressure ratio provided by the braking source based on the braking intensity.

[0043] The first matching module is used to match the braking intensity with a preset I curve to determine the ratio of braking pressure provided by the braking source to different drive wheels.

[0044] Optionally, the analysis module includes:

[0045] The second analysis submodule is used to analyze the braking information, determine the braking intensity required by the user, and perform power calculation on the braking intensity to obtain the total braking force required by the user.

[0046] The third analysis submodule is used to analyze the road surface information and determine the peak adhesion coefficient of the road surface where the vehicle is currently located.

[0047] The fourth analysis submodule is used to analyze the steering information based on a preset positive direction to determine the steering angle of the steering wheel;

[0048] The judgment module is used to comprehensively judge the total braking force, the peak adhesion coefficient, the steering angle and preset judgment conditions to determine the braking mode of the vehicle.

[0049] Optionally, the third analysis submodule includes:

[0050] The first analysis unit is used to analyze the current road surface information and determine the vehicle's slip ratio and adhesion coefficient.

[0051] The second analysis unit is used to analyze the slip ratio and the adhesion coefficient to determine the road surface curve of the current road surface;

[0052] The comparison module is used to compare the road surface curve with a preset reference road surface curve to determine the peak adhesion coefficient of the road surface where the vehicle is currently located.

[0053] Optionally, the second analysis submodule includes:

[0054] The third analysis unit is used to analyze the braking information and determine the displacement signal and displacement change rate of the vehicle brake pedal.

[0055] The first determining submodule is used to determine the user's braking intention based on the displacement change rate and the displacement signal;

[0056] The second determining submodule is used to determine the braking intensity required by the user based on the braking intention;

[0057] The fourth analysis unit is used to calculate and analyze the braking intensity to determine the braking force required for each wheel of the vehicle.

[0058] The summary module is used to organize and summarize the braking force required for each wheel to obtain the total braking force required by the user.

[0059] Optionally, the determination module includes:

[0060] The calculation module is used to perform dynamic calculations on the peak adhesion coefficient to determine the ground braking force of the road surface on the vehicle.

[0061] The judgment submodule is used to judge the total braking force and the ground braking force when the steering angle is greater than zero, and obtain the judgment result;

[0062] A determining unit is used to determine the braking mode of the vehicle based on the judgment result.

[0063] Optionally, the vehicle compound braking control device further includes:

[0064] The second analysis module is used to determine the adhesion coefficient of each wheel of the vehicle on the split road surface when the current road condition is a split road surface.

[0065] The second determining module is used to determine the distributed braking force of the wheel on the side with the smallest coefficient of adhesion.

[0066] The second matching module is used to match the distributed braking force with a preset I curve to determine the ratio of braking pressure provided by different drive wheels of the braking source on the split road surface.

[0067] This application also provides a control device for vehicle compound braking. The control device for vehicle compound braking is a physical node device. The control device for vehicle compound braking includes: a memory, a processor, and a program for the control method of vehicle compound braking stored in the memory and executable on the processor. When the program for the control method of vehicle compound braking is executed by the processor, it can implement the steps of the control method of vehicle compound braking as described above.

[0068] This application also provides a storage medium storing a program for implementing the above-described vehicle compound braking control method. When the program for the vehicle compound braking control method is executed by a processor, it implements the steps of the vehicle compound braking control method as described above.

[0069] This application provides a control method, device, equipment, and storage medium for vehicle composite braking. Compared with the prior art where the brake motor participates in regulating the braking pressure, it cannot simultaneously take into account the stability of the electric vehicle and the efficiency of the brake motor's energy recovery, resulting in low stability of the electric vehicle and low efficiency of the brake motor's energy recovery. In this application, the braking information required by the user and the road surface information of the road where the vehicle is currently located are identified, and the steering information of each steering wheel of the vehicle is received; the braking information, the road surface information, and the steering information are analyzed and processed to determine the braking mode of the vehicle; based on the braking mode and combined with the braking information, the pressure ratio provided by different braking sources of the vehicle and the braking pressure ratio provided by the braking sources to different drive wheels of the vehicle are obtained, so as to control the composite braking of the vehicle. In this application, as long as braking information, current road surface information, and steering information are obtained, the vehicle's braking mode can be determined based on these information. Under different braking modes, the braking pressure provided by different braking sources is adjusted, and the proportion of braking pressure provided by the braking sources to different drive wheels of the vehicle is determined. That is, in this application, based on braking information, road surface information, and steering information, the braking mode is automatically selected, and the proportion of braking pressure provided by the braking sources and the braking pressure provided by the braking sources to different wheels are reasonably allocated. Therefore, the stability of the electric vehicle and the efficiency of energy recovery by the brake motor are taken into account, thereby improving the stability of the electric vehicle and the efficiency of energy recovery by the brake motor. Attached Figure Description

[0070] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0071] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0072] Figure 1 This is a flowchart illustrating the first embodiment of the vehicle compound braking control method of this application;

[0073] Figure 2 This is a flowchart illustrating the third embodiment of the vehicle compound braking control method of this application;

[0074] Figure 3 This is a schematic diagram of the device structure of the hardware operating environment involved in the embodiments of this application;

[0075] Figure 4 This is a schematic diagram of the reference road surface curve used in the vehicle compound braking control method of this application.

[0076] Figure 5 This is a schematic diagram of the composite braking control system in the vehicle composite braking control method of this application;

[0077] Figure 6 This is a schematic diagram illustrating the determination of the adhesion coefficient in the vehicle compound braking control method of this application.

[0078] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0079] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0080] This application provides a control method for vehicle compound braking. In the first embodiment of the vehicle compound braking control method of this application, refer to... Figure 1 The control method for the vehicle's compound braking includes:

[0081] Step S10: Identify the braking information requested by the user and the road surface information of the road where the vehicle is currently located, and receive the steering information of each steering wheel of the vehicle.

[0082] Step S20: Analyze and process the braking information, road surface information, and steering information to determine the braking mode of the vehicle;

[0083] Step S30: Based on the braking mode and combined with the braking information, obtain the pressure ratio provided by different braking sources of the vehicle and the ratio of braking pressure provided by the braking sources to different drive wheels of the vehicle, so as to control the compound braking of the vehicle.

[0084] In this embodiment, the controller for controlling vehicle braking is divided into an upper-level controller and a lower-level controller. The upper-level controller is used to calculate the required longitudinal braking torque and additional yaw torque, and to select the braking operating mode. The lower-level controller is used to distribute the braking force to each wheel and allocate the proportion of motor braking and hydraulic braking on the drive wheels.

[0085] In other words, identifying the vehicle's braking information, identifying the road surface information of the road where the vehicle is currently located, receiving the steering information of each steering wheel, and determining the vehicle's braking mode are achieved through the upper-level controller; determining the pressure ratio provided by different braking sources of the vehicle, and the ratio of braking pressure provided by the braking sources to different drive wheels are achieved through the lower-level controller.

[0086] The specific steps are as follows:

[0087] Step S10: Identify the braking information requested by the user and the road surface information of the road where the vehicle is currently located, and receive the steering information of each steering wheel of the vehicle.

[0088] In this embodiment, it should be noted that the control method for vehicle compound braking can be applied to the control device for vehicle compound braking, which is subordinate to the control equipment for vehicle compound braking, and the control equipment for vehicle compound braking is part of the control system for vehicle compound braking.

[0089] For the control system of vehicle compound braking, there is a built-in μ-s curve model. This μ-s curve model is a pre-trained model. It should be noted that this μ-s curve model can specifically be a μ-s curve model that outputs the corresponding μ-s curve based on the input road surface adhesion coefficient and vehicle slip ratio.

[0090] It should be noted that the μ-s curve model has the advantages of simple fitting parameters and high fitting accuracy.

[0091] Where μ represents the adhesion coefficient of the road surface.

[0092] Where s represents the vehicle's slip ratio.

[0093] Among them, such as Figure 4 As shown, the μ-s curve model has preset μ-s curves for common road surfaces, that is, reference road surface curves.

[0094] Common road surfaces include at least dry cement road surfaces, dry asphalt road surfaces, wet cement road surfaces, wet asphalt road surfaces, snow road surfaces, and icy road surfaces.

[0095] It should be noted that the adhesion coefficient of the road surface is calculated based on the slip ratio using the μ(s) function.

[0096] Specifically, the μ(s) function is:

[0097]

[0098] Where c1, c2, and c3 represent the constant values ​​obtained from the fitting process, and different constant values ​​are obtained for different road surfaces.

[0099] Where μ(s) can be simplified to This represents the current road surface adhesion coefficient.

[0100] It should be noted that the fitting constant values ​​were obtained through simulation fitting using the Burckhardt model.

[0101] Burckhardt is a tire friction model.

[0102] In this embodiment, the vehicle's braking information can be identified through fuzzy control; the road surface information of the current road where the vehicle is located can be determined through the Burckhardt model and reference road surface curves; and the steering angle of each wheel can be determined through sensors.

[0103] Among them, fuzzy control can utilize the basic ideas and theoretical control methods of fuzzy mathematics to process and control variables that are too complex or difficult to describe precisely.

[0104] In this embodiment, the braking intention is determined by analyzing the displacement signal and displacement rate of the brake pedal using fuzzy control, and the braking intensity is determined based on the braking intention and the displacement signal of the brake pedal.

[0105] Step S20: Analyze and process the braking information, road surface information, and steering information to determine the braking mode of the vehicle.

[0106] The braking information includes at least the brake pedal displacement signal and the rate of change of brake pedal displacement.

[0107] Among them, road surface information includes at least the slip ratio of the steering wheels.

[0108] It should be noted that slip ratio is the proportion of slip component in wheel movement. The slip ratio generated by a vehicle is different on different road surfaces, and the slip ratio of each tire on the same road surface is also the same based on the degree of wear. Therefore, it is necessary to obtain the slip ratio of the steering wheels in real time.

[0109] Among them, the braking modes include at least the conventional braking mode and the combined braking mode.

[0110] It should be noted that in conventional braking mode, only hydraulic braking and ABS are engaged, while the brake motor does not participate in braking. In combined braking mode, both the brake motor and hydraulic system participate in braking, while ABS does not participate.

[0111] Among them, ABS stands for antilock brake system. Its function is to automatically control the amount of braking force of the brakes when the car is braking, so that the wheels are not locked, but are in a state of rolling and sliding, so as to ensure that the adhesion between the wheels and the ground is at its maximum.

[0112] In this embodiment, fuzzy control is used to analyze braking information to determine the braking intensity required by the user. Road surface information is controlled to determine the road surface adhesion coefficient, which is calculated using the μ(s) function. Steering information is used to determine the steering angle of the steering wheels. By combining braking intensity and adhesion coefficient with steering angle, it is determined that if the vehicle recovers braking energy during braking, it will not be in a dangerous state. In this case, a compound braking mode is selected, which allows the brake motor to recover braking energy. If the vehicle recovers braking energy during braking, it will be in a dangerous state. In this case, conventional braking is selected to ensure the safety of the vehicle and the user.

[0113] Specifically, the step of analyzing and processing the braking information, the road surface information, and the steering information to determine the vehicle's braking mode includes:

[0114] Step S21: Analyze the braking information to determine the braking intensity required by the user, and perform power calculation on the braking intensity to obtain the total braking force required by the user.

[0115] Braking intentions can be categorized into slow braking, moderate braking, and emergency braking.

[0116] In this embodiment, the braking intention is determined by fuzzy control of the brake pedal displacement signal and displacement change rate. A fuzzy inference rule table for braking based on the displacement signal and displacement change rate is used to more accurately determine the braking intention. Based on the braking intention and the pedal displacement signal, the braking intensity is determined.

[0117] It should be noted that braking intensity and braking force are directly proportional; that is, the greater the braking intensity, the greater the braking force.

[0118] Step S22: Analyze the road surface information to determine the peak adhesion coefficient of the road surface where the vehicle is currently located;

[0119] In this embodiment, road surface information is analyzed to determine the slip ratio of the steering wheel. The adhesion coefficient between the steering wheel and the current road surface is calculated using the μ(s) function. The slip ratio and adhesion coefficient are input into a preset μ-s curve to obtain the μ-s curve of the current road surface. The μ-s curve of the current road surface is then combined with a reference road surface curve to determine the two reference μ-s curves that are closest to the current road surface. Based on a preset peak adhesion coefficient formula, the peak adhesion coefficient is calculated from the two reference μ-s curves and the μ-s curve of the current road surface.

[0120] Specifically, the formula for the peak adhesion coefficient is:

[0121]

[0122] Where μmax is the peak adhesion coefficient. These are the adhesion coefficients of the two reference μ-s curves that are most similar to the current road surface, and μ1max and μ2max are the peak adhesion coefficients of the two selected road surfaces, respectively.

[0123] Step S23: Based on the preset positive direction, analyze the steering information to determine the steering angle of the steering wheel;

[0124] In this embodiment, the direction of vehicle travel can be defined as the positive direction, and the angle by which the axial wheel rotates relative to the positive direction can be determined, and this angle can be defined as the steering angle. It should be noted that other directions can also be defined as the positive direction, such as the direction of the sensor, the lateral direction of the vehicle, or any other arbitrary direction.

[0125] It should be noted that the positive direction of all steering wheels should be the same, but they can be different in special cases. For example, due to the installation position of the sensors, the sensors may not be able to detect certain directions, so the positive direction can be different; or the axle of the steering wheel may be a special axle, so the positive direction can be different, and so on.

[0126] Step S24: The total braking force, the peak adhesion coefficient, the steering angle, and the preset judgment conditions are comprehensively judged to determine the braking mode of the vehicle.

[0127] In this embodiment, the total braking force, peak adhesion coefficient, and steering angle are comprehensively judged. If the vehicle recovers braking energy during braking without causing the vehicle to be in a dangerous state, then a compound braking mode is selected, which allows the brake motor to brake and recover braking energy. If the vehicle recovers braking energy during braking, it will cause the vehicle to be in a dangerous state, then conventional braking is selected to ensure the safety of the vehicle and the user.

[0128] Specifically, the step of analyzing the road surface information to determine the peak adhesion coefficient of the road surface where the vehicle is currently located includes:

[0129] Step A10: Analyze the current road surface information to determine the vehicle's slip ratio and adhesion coefficient;

[0130] Step A20: Analyze the slip ratio and the adhesion coefficient to determine the road surface curve of the current road surface;

[0131] Step A30: Compare the road surface curve with a preset reference road surface curve to determine the peak adhesion coefficient of the road surface where the vehicle is currently located.

[0132] It should be noted that, based on the trend and characteristics of the μ-s curve of the reference road surface, the shape and trend of the μ-s curve of various road surfaces are the same. Based on this characteristic, the adhesion coefficient of the current road surface can be estimated by using the μ-s curve of the similar road surface to determine which road surface is more similar to the current road surface.

[0133] In this embodiment, the current road surface information is analyzed to determine the vehicle's slip ratio on the current road surface and the adhesion coefficient of the current road surface. The μ-s curve of the current road surface is determined by the adhesion coefficient and slip ratio using a μ-s curve model. From the reference road surface curves in the μ-s curve model, two reference curves that are most similar to the μ-s curve of the current road surface are selected. Based on the reference curves, the peak adhesion coefficient of the current road surface is determined.

[0134] Specifically, the steps of analyzing the braking information, determining the braking intensity required by the user, and performing power calculations on the braking intensity to obtain the total braking force required by the user include:

[0135] Step B10: Analyze the braking information to determine the displacement signal and displacement change rate of the vehicle brake pedal;

[0136] Step B20: Determine the user's braking intention based on the displacement change rate and the displacement signal;

[0137] Step B30: Based on the braking intention, determine the braking intensity required by the user;

[0138] Step B40: Calculate and analyze the braking intensity to determine the braking force required for each wheel of the vehicle;

[0139] Step B40: The braking force required for each wheel is compiled and summarized to obtain the total braking force required by the user.

[0140] In this embodiment, the displacement signal and rate of change of the brake pedal are first obtained from the braking information. The user's braking intention is analyzed based on the pedal displacement and rate of change to determine whether the user is braking slowly, moderately, or urgently. Based on the braking intention and displacement signal, the required braking force for each wheel is determined. Since the braking force of each wheel is in a different direction and the force is a vector, the resultant force cannot be calculated simply by addition and subtraction. Therefore, force analysis is required to obtain the total braking force required by the user.

[0141] Specifically, the step of comprehensively judging the total braking force, the peak adhesion coefficient, the steering angle, and preset judgment conditions to determine the braking mode of the vehicle includes:

[0142] Step C10: Perform dynamic calculation on the peak adhesion coefficient to determine the ground braking force of the road surface on the vehicle;

[0143] Step C20: When the steering angle is greater than zero, determine the total braking force and the ground braking force, and obtain the determination result;

[0144] Step C30: Based on the judgment result, determine the braking mode of the vehicle.

[0145] In this embodiment, if the steering angle is not zero, it is determined that the vehicle is in a steering state. In order to ensure the stability during steering, when the vehicle understeers or oversteers, the ABS needs to be adjusted to improve the stability of steering, so conventional braking is selected.

[0146] In this embodiment, if the steering angle is zero, the vehicle is traveling in a straight line. The magnitude of the ground braking force and the total braking force are determined. When the total braking force is less than the ground braking force, the front axle and rear axle braking of the vehicle are distributed according to the I curve. Neither the front axle braking force nor the rear axle braking force will reach the condition of locking up, so the appropriate braking is selected.

[0147] In this embodiment, when the braking force is always greater than or equal to the ground braking force, both the front axle brake and the rear axle brake will reach the condition of locking up, requiring adjustment of the ABS operation. To ensure the safety of the user and the vehicle, the conventional braking mode is selected.

[0148] Step S30: Based on the braking mode and combined with the braking information, obtain the pressure ratio provided by different braking sources of the vehicle and the ratio of braking pressure provided by the braking sources to different drive wheels of the vehicle, so as to control the compound braking of the vehicle.

[0149] The braking source may include brake hydraulic fluid and brake motor.

[0150] In this embodiment, different braking modes require different braking sources. It should be noted that compound braking uses a brake motor, which is necessary to recover braking energy.

[0151] In this embodiment, by identifying the vehicle's braking information, the current road surface information, and the vehicle's steering information, the braking mode when the vehicle brakes can be determined. Based on the braking mode, the proportion of braking source can be reasonably allocated for braking, and the proportion of braking pressure provided to different drive wheels can be reasonably allocated.

[0152] This application provides a control method, device, equipment, and storage medium for vehicle composite braking. Compared with the prior art where the brake motor participates in regulating the braking pressure, it cannot simultaneously take into account the stability of the electric vehicle and the efficiency of the brake motor's energy recovery, resulting in low stability of the electric vehicle and low efficiency of the brake motor's energy recovery. In this application, the braking information required by the user and the road surface information of the road where the vehicle is currently located are identified, and the steering information of each steering wheel of the vehicle is received; the braking information, the road surface information, and the steering information are analyzed and processed to determine the braking mode of the vehicle; based on the braking mode and combined with the braking information, the pressure ratio provided by different braking sources of the vehicle and the braking pressure ratio provided by the braking sources to different drive wheels of the vehicle are obtained, so as to control the composite braking of the vehicle. In this application, as long as braking information, current road surface information, and steering information are obtained, the vehicle's braking mode can be determined based on these information. Under different braking modes, the braking pressure provided by different braking sources is adjusted, and the proportion of braking pressure provided by the braking sources to different drive wheels of the vehicle is determined. That is, in this application, based on braking information, road surface information, and steering information, the braking mode is automatically selected, and the proportion of braking pressure provided by the braking sources and the braking pressure provided by the braking sources to different wheels are reasonably allocated. Therefore, the stability of the electric vehicle and the efficiency of energy recovery by the brake motor are taken into account, thereby improving the stability of the electric vehicle and the efficiency of energy recovery by the brake motor.

[0153] Furthermore, based on the first embodiment of this application, another embodiment of this application is provided. In this embodiment, the step of obtaining the pressure ratio provided by different braking sources of the vehicle and the ratio of braking pressure provided by the braking sources to different drive wheels of the vehicle based on the braking mode and in combination with the braking information includes:

[0154] Step D10: If the braking mode is compound braking, the braking signal is analyzed to obtain the braking intensity, and the pressure ratio provided by the braking source is determined based on the braking intensity.

[0155] Step D20: Match the braking intensity with the preset I curve to determine the ratio of braking pressure provided by the braking source to different drive wheels.

[0156] In this embodiment, the remaining amount of the vehicle battery is first determined, and the maximum braking intensity of the brake motor is determined. If the remaining amount of the battery is less than 80% of the total charge, it is determined that the vehicle battery does not need to be charged. At this time, hydraulic braking is selected. When the braking intensity of the current brake motor is less than or equal to the maximum braking intensity, only brake motor braking is used. When the braking intensity of the current brake motor is greater than the maximum braking intensity but less than the preset peak braking intensity, hybrid braking is used.

[0157] It should be noted that performing energy recovery when the battery has a remaining charge of 80% or more can easily damage the battery.

[0158] Specifically, the braking pressure distribution formula determines the proportion of braking pressure provided by the brake motor to different drive wheels.

[0159] The braking pressure formula is as follows:

[0160]

[0161] Where Fbfe is the braking force of the front wheels provided by the brake motor, Fbre is the braking force of the rear wheels provided by the brake motor, Z is the braking intensity, G is the vehicle weight, b is the rear axle distance from the center of gravity to the rear axle, a is the front axle distance from the center of gravity to the front axle, hg is the height of the center of gravity, and L is the distance between the front axle and the rear axle.

[0162] It should be noted that during mixed braking, the brake motor is used first. If the braking force of the brake motor is insufficient, the remaining braking force is provided by the brake hydraulic system.

[0163] In this embodiment, when the brake motor speed is less than the rated speed, the brake motor operates in the constant torque range. When the brake motor speed is greater than or equal to the rated speed, the brake motor operates in the constant power range.

[0164] It should be noted that when the brake motor is operating in the constant torque range, the braking distribution is performed using the first brake motor braking distribution formula.

[0165] The braking distribution formula for the first braking motor is as follows:

[0166]

[0167] Where Fbf is the braking force of the front wheels, Fbrm is the braking force provided by the brake hydraulic pressure to the rear wheels, Pmax is the maximum power of the brake motor, nN is the current speed of the brake motor, and r is the radius of the brake motor shaft.

[0168] It should be noted that when the brake motor is operating in the constant power range, the braking distribution is performed using the second brake motor braking distribution formula.

[0169] The braking distribution formula for the second brake motor is as follows:

[0170]

[0171] Where P is the current power of the brake motor, and n is the rated speed of the brake motor.

[0172] In this embodiment, by rationally allocating the pressure ratio provided by the braking source and the braking force of the wheels, energy consumption is reduced. Furthermore, by determining the braking source through the braking mode, vehicle stability during braking is ensured. In this embodiment, by rationally allocating the braking pressure ratio between the brake motor and the brake hydraulic fluid, the energy recovery efficiency of the brake motor can be improved.

[0173] Furthermore, based on the first embodiment of this application, another embodiment of this application is provided, in which the vehicle compound braking control method further includes:

[0174] Step E10: When the current road condition is a split road surface, determine the split adhesion coefficient of each wheel of the vehicle on the split road surface.

[0175] Step E20: Determine the distributed braking force of the wheel with the smallest coefficient of adhesion.

[0176] Step E30: Match the distributed braking force with the preset I curve to determine the ratio of braking pressure provided by different drive wheels of the braking source on the split road surface.

[0177] It should be noted that on split-road surfaces, the coefficients of adhesion between the left and right wheels and the road surface are different.

[0178] Specifically, when distributing braking torque on split-plane surfaces, the relationship between braking efficiency and braking stability must be considered simultaneously. If the left and right wheels are controlled independently, they can each achieve their optimal slip ratio, and the adhesion of each wheel is fully utilized, reducing braking time and distance. However, the difference in braking force between the left and right wheels will generate yaw moment, causing braking deviation. The greater the difference in the coefficient of adhesion between the left and right sides, the more pronounced this phenomenon becomes. If the braking force is distributed to the side with the higher coefficient of adhesion, the wheel with the lower coefficient of adhesion will lock up prematurely, negatively impacting braking stability. If the braking force is distributed to the side with the lower coefficient of adhesion, the wheel with the lower coefficient of adhesion can maintain its slip ratio near its optimal slip ratio, while the wheel with the higher coefficient of adhesion has the same braking force as the wheel with the lower coefficient of adhesion, resulting in a lower slip ratio and preventing lockup. Furthermore, the equal distribution of braking torque on both sides maintains good braking stability, but it increases the braking distance.

[0179] In this embodiment, distributing braking force according to the wheels on the side with the lower coefficient of friction provides good directional stability. Although the braking distance increases slightly, it will not cause a dangerous situation as long as it remains within a suitable range. Therefore, in this embodiment, the braking torque distribution on split-road surfaces is based on the braking torque of the wheels on the side with the lower coefficient of friction. This embodiment can balance vehicle stability while rationally distributing the braking pressure ratio from the braking source.

[0180] Reference Figure 3 , Figure 3 This is a schematic diagram of the device structure of the hardware operating environment involved in the embodiments of this application.

[0181] like Figure 3 As shown, the control device for the vehicle's compound braking system may include: a processor 1001, such as a CPU, a memory 1005, and a communication bus 1002. The communication bus 1002 is used to establish communication between the processor 1001 and the memory 1005. The memory 1005 may be a high-speed RAM or a stable, non-volatile memory, such as a disk drive. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0182] Optionally, the control equipment for the vehicle's composite braking system may also include a rectangular user interface, a network interface, a camera, RF (Radio Frequency) circuitry, sensors, audio circuitry, a WiFi module, etc. The rectangular user interface may include a display screen and an input submodule such as a keyboard. Optionally, the rectangular user interface may also include a standard wired interface or a wireless interface. The network interface may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface).

[0183] Those skilled in the art will understand that Figure 3 The control device structure for vehicle compound braking shown does not constitute a limitation on the control device for vehicle compound braking. It may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0184] like Figure 3 As shown, the memory 1005, serving as a storage medium, may include an operating system, a network communication module, and a control program for the vehicle's compound braking system. The operating system is a program that manages and controls the hardware and software resources of the vehicle's compound braking control equipment, supporting the operation of the vehicle's compound braking control program and other software and / or programs. The network communication module is used to enable communication between the various components within the memory 1005, as well as communication with other hardware and software in the vehicle's compound braking control system.

[0185] exist Figure 3 In the vehicle compound braking control device shown, the processor 1001 is used to execute the vehicle compound braking control program stored in the memory 1005 to implement the steps of the vehicle compound braking control method described in any of the above claims.

[0186] The specific implementation of the control device for vehicle compound braking in this application is basically the same as the embodiments of the control method for vehicle compound braking described above, and will not be repeated here.

[0187] This application also provides a control device for vehicle compound braking, the control device for vehicle compound braking comprising:

[0188] The identification module is used to identify the braking information requested by the user and the road surface information of the road where the vehicle is currently located, and to receive the steering information of each steering wheel of the vehicle.

[0189] The first analysis module is used to analyze and process the braking information, the road surface information, and the steering information to determine the braking mode of the vehicle.

[0190] The first determining module is used to determine, based on the braking mode and in conjunction with the braking information, the pressure ratio provided by different braking sources of the vehicle and the ratio of braking pressure provided by the braking sources to different drive wheels of the vehicle, so as to control the compound braking of the vehicle.

[0191] Optionally, the braking mode includes conventional braking and combined braking;

[0192] The first determining module includes:

[0193] The first analysis submodule is used to analyze the braking signal to obtain the braking intensity if the braking mode is compound braking, and to determine the pressure ratio provided by the braking source based on the braking intensity.

[0194] The first matching module is used to match the braking intensity with a preset I curve to determine the ratio of braking pressure provided by the braking source to different drive wheels.

[0195] Optionally, the analysis module includes:

[0196] The second analysis submodule is used to analyze the braking information, determine the braking intensity required by the user, and perform power calculation on the braking intensity to obtain the total braking force required by the user.

[0197] The third analysis submodule is used to analyze the road surface information and determine the peak adhesion coefficient of the road surface where the vehicle is currently located.

[0198] The fourth analysis submodule is used to analyze the steering information based on a preset positive direction to determine the steering angle of the steering wheel;

[0199] The judgment module is used to comprehensively judge the total braking force, the peak adhesion coefficient, the steering angle and preset judgment conditions to determine the braking mode of the vehicle.

[0200] Optionally, the third analysis submodule includes:

[0201] The first analysis unit is used to analyze the current road surface information and determine the vehicle's slip ratio and adhesion coefficient.

[0202] The second analysis unit is used to analyze the slip ratio and the adhesion coefficient to determine the road surface curve of the current road surface;

[0203] The comparison module is used to compare the road surface curve with a preset reference road surface curve to determine the peak adhesion coefficient of the road surface where the vehicle is currently located.

[0204] Optionally, the second analysis submodule includes:

[0205] The third analysis unit is used to analyze the braking information and determine the displacement signal and displacement change rate of the vehicle brake pedal.

[0206] The first determining submodule is used to determine the user's braking intention based on the displacement change rate and the displacement signal;

[0207] The second determining submodule is used to determine the braking intensity required by the user based on the braking intention;

[0208] The fourth analysis unit is used to calculate and analyze the braking intensity to determine the braking force required for each wheel of the vehicle.

[0209] The summary module is used to organize and summarize the braking force required for each wheel to obtain the total braking force required by the user.

[0210] Optionally, the determination module includes:

[0211] The calculation module is used to perform dynamic calculations on the peak adhesion coefficient to determine the ground braking force of the road surface on the vehicle.

[0212] The judgment submodule is used to judge the total braking force and the ground braking force when the steering angle is greater than zero, and obtain the judgment result;

[0213] A determining unit is used to determine the braking mode of the vehicle based on the judgment result.

[0214] Optionally, the vehicle compound braking control device further includes:

[0215] The second analysis module is used to determine the adhesion coefficient of each wheel of the vehicle on the split road surface when the current road condition is a split road surface.

[0216] The second determining module is used to determine the distributed braking force of the wheel on the side with the smallest coefficient of adhesion.

[0217] The second matching module is used to match the distributed braking force with a preset I curve to determine the ratio of braking pressure provided by different drive wheels of the braking source on the split road surface.

[0218] The specific implementation of the control device for vehicle compound braking in this application is basically the same as the embodiments of the control method for vehicle compound braking described above, and will not be repeated here.

[0219] This application provides a storage medium that stores one or more programs, which can be executed by one or more processors to implement the steps of the vehicle compound braking control method described in any of the above claims.

[0220] The specific implementation of the storage medium in this application is basically the same as the various embodiments of the above-described vehicle compound braking control method, and will not be repeated here.

[0221] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0222] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0223] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0224] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A control method for vehicle compound braking, characterized in that, The control method for vehicle compound braking includes: It identifies the braking information required by the user and the road surface information of the current road where the vehicle is located, and receives the steering information of each steering wheel of the vehicle. The braking information, road surface information, and steering information are analyzed and processed to determine the braking mode of the vehicle; Based on the braking mode and combined with the braking information, the pressure ratio provided by different braking sources of the vehicle and the ratio of braking pressure provided by the braking sources to different drive wheels of the vehicle are obtained, so as to control the compound braking of the vehicle. The step of analyzing and processing the braking information, the road surface information, and the steering information to determine the vehicle's braking mode includes: The braking information, road surface information, and steering information are analyzed and processed to obtain the braking intensity required by the user, the adhesion coefficient of the road, and the steering angle of the steering wheel, respectively. Based on the braking intensity, the adhesion coefficient, and the steering angle, it is determined whether the vehicle will be in a dangerous state when braking and regenerating braking energy; If there is no danger, the braking mode is determined to be composite braking, in which the brake motor and hydraulic pressure work together to brake, and the ABS does not participate in braking. If a dangerous situation is to occur, the braking mode is determined to be conventional braking, which is hydraulic braking and ABS operation, with the brake motor not participating in braking; The braking information is analyzed to determine the braking intensity required by the user, and the braking intensity is used to perform power calculation to obtain the total braking force required by the user. The road surface information is analyzed to determine the peak adhesion coefficient of the road surface where the vehicle is currently located; Based on a preset positive direction, the steering information is analyzed to determine the steering angle of the steering wheel; The peak adhesion coefficient is used to perform dynamic calculations to determine the ground braking force of the road surface on the vehicle; When the steering angle is not zero, the braking mode is determined to be the conventional braking mode; When the steering angle is zero, the total braking force and the ground braking force are judged to obtain the judgment result; Based on the judgment result, the braking mode of the vehicle is determined; The step of determining the braking mode of the vehicle based on the judgment result includes: If the total braking force is less than the ground braking force, then the braking mode is determined to be the compound braking. If the total braking force is greater than the ground braking force, then the braking mode is determined to be the conventional braking mode.

2. The vehicle compound braking control method as described in claim 1, characterized in that, The braking mode includes compound braking. The step of obtaining, based on the braking mode and in conjunction with the braking information, the pressure ratio provided by different braking sources to the vehicle and the ratio of braking pressure provided by the braking sources to different drive wheels of the vehicle, includes: If the braking mode is a compound braking, the braking information is analyzed to obtain the braking intensity, and based on the braking intensity, the pressure ratio provided by the braking source is determined. The braking intensity is matched with a preset I-curve to determine the ratio of braking pressure provided by the braking source to different drive wheels.

3. The vehicle compound braking control method as described in claim 1, characterized in that, The step of analyzing the road surface information to determine the peak adhesion coefficient of the road surface where the vehicle is currently located includes: The current road surface information is analyzed to determine the vehicle's slip ratio and adhesion coefficient. The slip ratio and the adhesion coefficient are analyzed to determine the road surface curve of the current road surface; The peak adhesion coefficient of the road surface where the vehicle is currently located is determined by comparing the road surface curve with a preset reference road surface curve.

4. The vehicle compound braking control method as described in claim 1, characterized in that, The steps of analyzing the braking information, determining the braking intensity required by the user, and performing power calculations on the braking intensity to obtain the total braking force required by the user include: The braking information is analyzed to determine the displacement signal and displacement rate of the vehicle's brake pedal. Based on the displacement change rate and the displacement signal, the user's braking intention is determined; Based on the braking intention, determine the braking intensity required by the user; The braking intensity is calculated and analyzed to determine the braking force required for each wheel of the vehicle; The braking force required for each wheel is compiled and summarized to obtain the total braking force required by the user.

5. The vehicle compound braking control method as described in claim 1, characterized in that, The vehicle compound braking control method also includes: When the current road surface is a split road surface, determine the split adhesion coefficient of each wheel of the vehicle on the split road surface; Determine the distribution of braking force to the wheel on the side with the minimum coefficient of adhesion; The distributed braking force is matched with a preset I curve to determine the ratio of braking pressure provided by different drive wheels of the braking source on the split road surface.

6. A control device for vehicle compound braking, characterized in that, The control device for the vehicle's combined braking system includes: The identification module is used to identify the braking information requested by the user and the road surface information of the road where the vehicle is currently located, and to receive the steering information of each steering wheel of the vehicle. The first analysis module is used to analyze and process the braking information, the road surface information, and the steering information to determine the braking mode of the vehicle. The first determining module is used to determine, based on the braking mode and in conjunction with the braking information, the pressure ratio provided by different braking sources of the vehicle and the ratio of braking pressure provided by the braking sources to different drive wheels of the vehicle, so as to control the compound braking of the vehicle. The first analysis module is further configured to analyze and process the braking information, road surface information, and steering information to obtain the braking intensity required by the user, the coefficient of friction of the road, and the steering angle of the steering wheels, respectively; based on the braking intensity, the coefficient of friction, and the steering angle, determine whether the vehicle will be in a dangerous state when braking and recovering braking energy; if it will not be in a dangerous state, determine that the braking mode is composite braking, in which the brake motor and hydraulic system jointly participate in braking, and ABS does not participate in braking; if it will be in a dangerous state, determine that the braking mode is conventional braking, in which hydraulic braking and ABS work, and the brake motor does not participate in braking; analyze the braking information to determine the braking intensity required by the user, and further process the braking intensity... The system calculates the total braking force required by the user; analyzes the road surface information to determine the peak adhesion coefficient of the road surface where the vehicle is currently located; analyzes the steering information based on a preset positive direction to determine the steering angle of the steering wheels; calculates the power based on the peak adhesion coefficient to determine the ground braking force of the road surface on the vehicle; when the steering angle is not zero, the braking mode is determined to be conventional braking; when the steering angle is equal to zero, the total braking force and the ground braking force are judged to obtain a judgment result; based on the judgment result, the braking mode of the vehicle is determined; if the total braking force is less than the ground braking force, the braking mode is determined to be compound braking; if the total braking force is greater than the ground braking force, the braking mode is determined to be conventional braking.

7. A control device for vehicle compound braking, characterized in that, The control device for the vehicle's compound braking includes: a memory, a processor, and a program stored in the memory for implementing the control method for the vehicle's compound braking. The memory is used to store the program for implementing the control method of vehicle compound braking; The processor is configured to execute a program for implementing the control method for vehicle compound braking, thereby implementing the steps of the control method for vehicle compound braking as described in any one of claims 1 to 5.

8. A storage medium, characterized in that, The storage medium stores a program for implementing a control method for vehicle compound braking, which is executed by a processor to implement the steps of the control method for vehicle compound braking as described in any one of claims 1 to 5.

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