Vehicle control method and vehicle
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-01-28
- Publication Date
- 2026-08-13
Smart Images
Figure CN2026075483_13082026_PF_FP_ABST
Abstract
Description
Vehicle control methods and vehicles
[0001] Cross-reference to related applications
[0002] This application is based on and claims priority to Chinese Patent Application No. 2025101391119, filed on February 7, 2025, the entire contents of which are incorporated herein by reference. Technical Field
[0003] This application relates to the field of vehicles, and more specifically, to a method for controlling a vehicle and a vehicle. Background Technology
[0004] As vehicles are increasingly used in people's daily lives, users have higher and higher requirements for vehicle safety performance. Among these, vehicle braking safety performance is one of the important indicators of vehicle safety. In related technologies, during the braking process, the front and rear brakes are prone to lock up asynchronously, causing the vehicle to lose directional stability, resulting in lower braking efficiency and affecting driving safety, thus impacting the user experience. Summary of the Invention
[0005] This application provides a vehicle control method and a vehicle to improve vehicle stability and driving safety.
[0006] In a first aspect, embodiments of this application provide a vehicle control method, including:
[0007] Obtain the current road conditions corresponding to the vehicle;
[0008] Based on the current road conditions, the vehicle's synchronous adhesion coefficient under the current road conditions and current load is obtained, and the braking force corresponding to the front wheel brake and rear wheel brake of the vehicle is adjusted to control the vehicle to brake.
[0009] In the above technical solution, the synchronous adhesion coefficient is determined by the current road conditions and current load of the vehicle. The braking force distributed between the front and rear brakes of the vehicle is adjusted based on the synchronous adhesion coefficient to control the vehicle braking. This can increase the probability of the front and rear wheels locking up synchronously during braking, thereby improving the vehicle's stability and braking efficiency, reducing the braking distance, improving driving safety, and is applicable to various road surfaces, thus having universality.
[0010] In some embodiments, the synchronous adhesion coefficient is determined based on the following steps:
[0011] Based on the current road surface conditions, the ideal curve of the synchronous adhesion coefficient of the vehicle under the current load is queried to obtain the synchronous adhesion coefficient corresponding to the current road surface conditions.
[0012] In the above technical solution, the synchronous adhesion coefficient corresponding to the current road surface condition is obtained through the ideal curve of the synchronous adhesion coefficient of the vehicle under the current load. The operation is simple and convenient, and it can quickly and accurately obtain the synchronous adhesion coefficient of the vehicle under the current road surface condition and current load. It has high calculation efficiency, can ensure the vehicle's rapid braking response, and improve braking safety.
[0013] In some embodiments, the ideal curve of the synchronous adhesion coefficient under the current load is determined based on the following steps:
[0014] While ensuring that the vehicle's weight, center of gravity height, distance from the center of gravity to the rear axle, and wheelbase remain unchanged under the current load, obtain the synchronous adhesion coefficient of the vehicle under different road conditions.
[0015] Based on the synchronous adhesion coefficient corresponding to each of the aforementioned road surface conditions, the ideal curve of the synchronous adhesion coefficient is plotted.
[0016] In the above technical solution, by pre-constructing ideal curves of synchronous adhesion coefficients under various loads, it is possible to directly locate the target while the vehicle is in motion, thereby improving processing efficiency and response speed and enhancing driving safety.
[0017] In some embodiments, adjusting the braking forces corresponding to the front and rear wheel brakes of the vehicle based on the synchronous adhesion coefficient of the vehicle under the current road conditions and current load, obtained from the current road conditions, to control the vehicle to brake, includes:
[0018] Based on the synchronous adhesion coefficient, the target braking force distribution coefficients corresponding to the front wheel brake and the rear wheel brake are obtained;
[0019] Based on the target braking force distribution coefficient, the braking force corresponding to the front wheel brakes and rear wheel brakes of the vehicle is adjusted.
[0020] In the above technical solution, the target braking force distribution coefficient is obtained by determining the synchronous adhesion coefficient based on the current road conditions and current load. The target braking force distribution coefficient can be updated in real time based on the actual driving conditions of the vehicle. Thus, the braking force corresponding to the front wheel brakes and rear wheel brakes of the vehicle can be adjusted in real time based on the target braking force distribution coefficient. This allows the vehicle to distribute braking force based on the I curve on any road surface, which has high control real-time performance, control efficiency and control accuracy. It can make the front and rear wheels of the vehicle lock up synchronously as much as possible, improve stability, and thus improve driving safety.
[0021] In some embodiments, adjusting the braking forces corresponding to the front and rear wheel brakes of the vehicle based on the synchronous adhesion coefficient of the vehicle under the current road conditions and current load, obtained from the current road conditions, to control the vehicle to brake, includes:
[0022] Based on the synchronous adhesion coefficient, the current of the motors corresponding to the front wheel brake and the rear wheel brake is adjusted.
[0023] In the above technical solution, the clamping force is adjusted by regulating the current of the motors corresponding to the front and rear wheel brakes according to the synchronous adhesion coefficient, thereby adjusting the braking force of the front and rear wheel brakes of the vehicle. The operation is simple and convenient, and it has high control efficiency and control precision. It is applicable to any road conditions and has universality, which can further improve the stability of the vehicle and thus improve braking safety.
[0024] In some embodiments, obtaining the current road conditions corresponding to the vehicle includes:
[0025] Obtain the current road surface adhesion coefficient corresponding to the vehicle;
[0026] The current road surface condition is determined based on the current road surface adhesion coefficient.
[0027] In the above technical solution, determining the current road surface condition by the current road surface adhesion coefficient has high precision, accuracy and real-time performance, which helps to improve the accuracy of the subsequently determined synchronous adhesion coefficient, thereby improving braking safety.
[0028] In some embodiments, obtaining the current road surface adhesion coefficient corresponding to the vehicle includes:
[0029] The current road surface adhesion coefficient is calculated based on the vehicle's wheel speed, braking stroke signal, motor torque, and motor speed.
[0030] In the above technical solution, the current road surface adhesion coefficient is calculated by using the vehicle's wheel speed, braking stroke signal, motor torque, and motor speed. During vehicle operation, the road surface adhesion coefficient can be automatically calculated based on working parameters collected at different time periods to detect the current road surface conditions in real time. This provides high real-time performance, improves the accuracy of the subsequently determined synchronous adhesion coefficient, and thus enhances driving safety.
[0031] In some embodiments, obtaining the current road conditions corresponding to the vehicle includes:
[0032] The current road surface conditions are determined by identifying environmental images of the vehicle's surroundings captured by an image sensor.
[0033] In the above technical solution, the current road conditions are determined by recognizing the environmental images around the vehicle collected by the image sensor. The road conditions can be updated in real time according to the dynamically changing environment, thus providing real-time performance.
[0034] In some embodiments, obtaining the current road conditions corresponding to the vehicle includes:
[0035] Image recognition is performed on the acquired environmental images around the vehicle, and the first road surface condition is determined based on the image recognition results;
[0036] Based on the vehicle's operating parameters, the current road surface adhesion coefficient corresponding to the vehicle is calculated.
[0037] The current road surface condition is determined based on the first road surface condition and the current road surface adhesion coefficient.
[0038] In the above technical solution, by combining image recognition and calculating the current road surface adhesion coefficient based on the actual working parameters of the vehicle to comprehensively determine the current road surface condition, the accuracy and precision of the current road surface condition obtained can be further improved, which helps to improve the accuracy of the subsequently determined synchronous adhesion coefficient, thereby improving braking safety.
[0039] In some embodiments, adjusting the braking forces corresponding to the front and rear wheel brakes of the vehicle based on the synchronous adhesion coefficient of the vehicle under the current road conditions and current load, obtained from the current road conditions, to control the vehicle to brake, includes:
[0040] Based on the synchronous adhesion coefficient, the target braking force distribution coefficients corresponding to the front wheel brake and the rear wheel brake are obtained;
[0041] The vehicle's electromechanical braking system is adjusted according to the target braking force distribution coefficient.
[0042] In the above technical solution, the synchronous adhesion coefficient is updated in real time according to the current road conditions, and the target braking force distribution coefficient is updated accordingly. The vehicle's electromechanical braking system is adjusted according to the target braking force distribution coefficient to adjust the clamping force of the motors corresponding to the front wheel brakes and the rear wheel brakes respectively. This allows the braking force to be distributed based on the I curve regardless of the road surface during braking, so as to meet the synchronous lock-up conditions as much as possible. The operation is simple and convenient, and it has high control efficiency and control accuracy, further improving the stability of the vehicle and thus improving braking safety.
[0043] Secondly, embodiments of this application provide a vehicle control device, including:
[0044] The first processing module is used to obtain the current road conditions corresponding to the vehicle;
[0045] The second processing module is used to adjust the braking force corresponding to the front wheel brake and the rear wheel brake of the vehicle based on the synchronous adhesion coefficient of the vehicle under the current road conditions and current load, thereby controlling the vehicle to brake.
[0046] Thirdly, embodiments of this application provide a vehicle, including:
[0047] The braking system operates based on the vehicle control method described in the first aspect. Attached Figure Description
[0048] Figure 1 is a schematic flowchart of one of the vehicle control methods provided in some embodiments of this application;
[0049] Figure 2 is a schematic diagram of one of the vehicle control methods provided in some embodiments of this application;
[0050] Figure 3 is a schematic diagram of the principle of a vehicle control method provided in some embodiments of this application (the second one).
[0051] Figure 4 is a second schematic flowchart of a vehicle control method provided in some embodiments of this application;
[0052] Figure 5 is a schematic diagram of the structure of a vehicle control device provided in some embodiments of this application;
[0053] Figure 6 is a schematic diagram of the structure of an electronic device provided in some embodiments of this application. Detailed Implementation
[0054] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0055] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.
[0056] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.
[0057] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0058] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.
[0059] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).
[0060] The vehicle control method, vehicle control device, electronic device, and readable storage medium provided in this application will be described in detail below with reference to the accompanying drawings and through specific embodiments and application scenarios.
[0061] The vehicle control method can be applied to the terminal, and can be executed by the hardware or software in the terminal.
[0062] The vehicle control method provided in this application embodiment can be executed by a vehicle, a functional module or entity in the vehicle that can implement the vehicle control method, or an electronic device or server that is communicatively connected to the vehicle. The electronic devices mentioned in this application embodiment include, but are not limited to, mobile phones, tablets, computers, cameras, and wearable devices. The vehicle control method provided in this application embodiment is described below using a vehicle as the execution subject as an example.
[0063] The inventors discovered that in related technologies, once the specifications of the front and rear brakes in the current braking system are determined, the braking force ratio of the front and rear brakes is a fixed value. When the weight of the vehicle is fixed, the synchronous adhesion coefficient is also a fixed value. This will cause the front and rear brakes to lock up asynchronously when the vehicle is driving on different road surfaces. If the synchronous adhesion coefficient is too large, the front wheels will lock up too early, resulting in a "nose-diving" phenomenon during emergency braking, and it is easy to cause danger when turning and decelerating. If the synchronous adhesion coefficient is too small, the rear wheels will lock up too early, which will cause the vehicle to fishtail, deviate from the lane, and easily cause rear axle sideslip, making the vehicle lose directional stability, resulting in low braking efficiency and affecting driving safety.
[0064] Based on the above considerations, in order to solve the problems of low braking efficiency and easy skidding during braking that affects driving safety, the inventors, after in-depth research, designed a vehicle control method, which includes obtaining the current road conditions corresponding to the vehicle; and adjusting the braking force corresponding to the front wheel brakes and rear wheel brakes of the vehicle based on the synchronous adhesion coefficient of the vehicle under the current road conditions and current load, thereby controlling the vehicle to brake.
[0065] In this vehicle control method, the synchronous adhesion coefficient is determined based on the current road conditions and current load of the vehicle. The braking force distributed between the front and rear brakes is adjusted based on the synchronous adhesion coefficient to control the vehicle braking. This method can increase the probability of the front and rear wheels locking up synchronously during braking, thereby improving vehicle stability and braking efficiency, reducing braking distance, improving driving safety, and is applicable to various road surfaces, making it universally applicable.
[0066] As shown in Figure 1, the vehicle control method includes steps 110 and 120.
[0067] Step 110: Obtain the current road conditions corresponding to the vehicle;
[0068] In this step, the current road surface condition is used to characterize the relevant road surface parameters of the road surface on which the vehicle is currently traveling, including but not limited to the type of road surface such as asphalt road surface, cement road surface and mud road surface, and the condition of the road surface such as dry, good or slippery.
[0069] In some embodiments, the current road surface condition may also include the relevant information about the attachments on the current road surface and the physicochemical properties of the attachments.
[0070] For example, for a certain type of road surface, the current road surface condition may also include parameters used to characterize whether there are adhering substances such as water, ice, snow, and oil on the road surface.
[0071] For example, in cases where there are deposits such as snow, the current road surface condition can also include physicochemical properties that characterize the looseness of the snow, the compaction of the snow, and whether there is ice or other substances mixed in the snow.
[0072] In some embodiments, the current road conditions can be determined by user input, such as through voice input or by inputting the current road conditions through the interactive interface of the vehicle terminal.
[0073] In some embodiments, step 110 may include:
[0074] It identifies environmental images of the vehicle's surroundings captured by image sensors to determine the current road conditions.
[0075] In this embodiment, image information including the surrounding environment and road conditions can be collected by image sensors and the like, and image recognition can be performed to determine the type of the current road surface and other information, thereby determining the current road surface condition.
[0076] The vehicle control method provided in the embodiments of this application determines the current road conditions by recognizing the environmental images around the vehicle collected by the image sensor, and can update the road conditions in real time according to the dynamically changing environment, thus having real-time performance.
[0077] In some embodiments, the current road conditions can also be calculated based on the relevant operating parameters of the vehicle during its current driving process.
[0078] As shown in Figure 4, in some embodiments, step 110 may include:
[0079] Obtain the current road surface adhesion coefficient corresponding to the vehicle;
[0080] The current road surface condition is determined based on the current road surface adhesion coefficient.
[0081] In this embodiment, the coefficient of adhesion is the ratio of the adhesion force to the wheel normal (direction perpendicular to the road surface) pressure, which can be approximated as the static friction coefficient between the tire and the road surface, and is determined by the road surface and the tire; for example, on dry, good asphalt roads, the coefficient of adhesion can usually reach 0.7-0.8; while on icy and snowy roads, the coefficient of adhesion may only be around 0.1, and even lower to 0.07 when the wheel slips.
[0082] Current road surface adhesion coefficient The actual road surface adhesion coefficient is the coefficient of friction between the vehicle and the road surface it is currently on. The actual road surface adhesion coefficient may be different for the same vehicle with the same load on different road surfaces.
[0083] The current road surface adhesion coefficient can be approximated as the maximum adhesion rate under the current road surface conditions. The current road surface adhesion coefficient can be estimated based on the slip ratio s and the adhesion rate μ, such as by estimating based on the μ-s curve.
[0084] Within the range of low slip ratio (0-10%), the slope of the μ-s curve varies under different road surface adhesion conditions. By fitting the slope within this small range of data, the road surface adhesion coefficient can be approximately estimated.
[0085] Within a range with a large slip ratio (above 0-20%), the adhesion rate will first increase and then decrease. The maximum adhesion rate will appear at the position where the slope is zero. By calculating dμ / ds in real time, the adhesion rate corresponding to when dμ / ds is close to 0 is the current road surface adhesion coefficient.
[0086] In actual implementation, the current road surface adhesion coefficient of the vehicle can be calculated by establishing a vehicle kinematics and dynamics model, taking into account factors such as vehicle weight, suspension system, and tires.
[0087] The current road surface adhesion coefficient can be used to determine the current road surface condition of the road on which the vehicle is traveling.
[0088] The vehicle control method provided in the embodiments of this application determines the current road surface condition by using the current road surface adhesion coefficient. This method has high precision, accuracy, and real-time performance, which helps to improve the accuracy of the subsequently determined synchronous adhesion coefficient, thereby improving braking safety.
[0089] In some embodiments, obtaining the current road surface adhesion coefficient corresponding to the vehicle may include:
[0090] The current road surface adhesion coefficient is calculated based on the vehicle's wheel speed, braking stroke signal, motor torque, and motor speed.
[0091] In this embodiment, the wheel speed of the vehicle is used to determine the vehicle speed.
[0092] The actual braking torque of the front and rear wheels can be calculated from the braking stroke signal, motor torque, and motor speed, based on the front wheel braking control torque and the rear wheel braking control torque. The acceleration of the front and rear wheels and the vehicle acceleration can be calculated by integrating the front wheel speed, rear wheel speed, and vehicle speed. The current road surface adhesion coefficient can be calculated based on the front and rear wheel acceleration, vehicle acceleration, and the actual braking torque of the front and rear wheels.
[0093] According to the vehicle control method provided in this application embodiment, the current road surface adhesion coefficient is calculated by using the vehicle's wheel speed, braking stroke signal, motor torque, and motor speed. During vehicle operation, the road surface adhesion coefficient can be automatically calculated based on the working parameters collected at different time periods to detect the current road surface conditions in real time. This method has high real-time performance and improves the accuracy of the subsequently determined synchronous adhesion coefficient, thereby enhancing driving safety.
[0094] In some embodiments, the current road surface condition can be determined by combining multiple different methods.
[0095] In some embodiments, step 110 may include:
[0096] Image recognition is performed on the acquired images of the environment around the vehicle, and the first road surface condition is determined based on the image recognition results;
[0097] Based on the vehicle's operating parameters, the current road surface adhesion coefficient corresponding to the vehicle is calculated.
[0098] The current road surface condition is determined based on the first road surface condition and the current road surface adhesion coefficient.
[0099] In this embodiment, the operating parameters may include: vehicle wheel speed, braking stroke signal, motor torque, and motor speed, etc.
[0100] The current road surface condition can be pre-identified by collecting image information through image sensors to obtain the first road surface condition. Then, the current road surface adhesion coefficient calculated based on the working parameters is combined to comprehensively determine the current road surface condition.
[0101] The vehicle control method provided in this application combines image recognition and calculation of the current road surface adhesion coefficient based on the vehicle's actual working parameters to comprehensively determine the current road surface condition. This can further improve the accuracy and precision of the obtained current road surface condition, which helps to improve the accuracy of the subsequently determined synchronous adhesion coefficient, thereby improving braking safety.
[0102] Of course, in other embodiments, any other feasible method can be used to determine the current road surface condition. The appropriate method can be flexibly selected according to the actual situation, and this application does not limit it here.
[0103] Step 120: Based on the synchronous adhesion coefficient of the vehicle under the current road conditions and current load, adjust the braking force of the front and rear wheel brakes of the vehicle to control the vehicle to brake.
[0104] During this step, the braking force of the vehicle's front and rear wheel brakes can be adjusted.
[0105] Under the current road conditions and load, the coefficient of friction for the front and rear wheels of the vehicle when they lock simultaneously is called the synchronous friction coefficient.
[0106] Given the current road conditions and load of the vehicle, the synchronous adhesion coefficient under the current road conditions and load can be obtained. Based on the synchronous adhesion coefficient, the braking force of the front and rear brakes of the vehicle can be adjusted so that the front and rear wheels can lock up synchronously during braking, thereby improving the stability of the vehicle.
[0107] According to the vehicle control method provided in the embodiments of this application, the synchronous adhesion coefficient is determined by the current road conditions and current load of the vehicle. The braking force distributed between the front and rear brakes of the vehicle is adjusted based on the synchronous adhesion coefficient to control the vehicle braking. This method can increase the probability of the front and rear wheels locking up synchronously during braking, thereby improving the stability and braking efficiency of the vehicle, reducing the braking distance, improving driving safety, and is applicable to various road surfaces, thus having universality.
[0108] In some embodiments, the synchronous adhesion coefficient can be determined based on the following steps:
[0109] By querying the ideal curve of the synchronous adhesion coefficient of the vehicle under the current load based on the current road conditions, the synchronous adhesion coefficient corresponding to the current road conditions can be obtained.
[0110] In this embodiment, the ideal curve of synchronous adhesion coefficient, i.e., the I curve, as shown in Figure 3, is used to characterize the front and rear wheel brake force distribution when the front and rear wheels lock up synchronously when the vehicle is traveling on different road surfaces under a certain weight. Given that the vehicle parameters and weight are fixed, there is generally a front and rear wheel brake force distribution ratio for a road surface condition. By connecting the points corresponding to the ideal front and rear brake force distribution ratios for various road surface conditions under the same weight, the I curve can be obtained.
[0111] By finding the ideal curve of the synchronous adhesion coefficient under the current load by finding the current road surface conditions, the synchronous adhesion coefficient under the current load and road surface conditions can be obtained.
[0112] The ideal curve for the synchronous adhesion coefficient can be a pre-generated and stored curve, with different ideal curves corresponding to different loads. Any feasible method can be used to pre-obtain and store the ideal curves for the synchronous adhesion coefficient of the vehicle under different load conditions. During actual execution, the corresponding ideal curve for the synchronous adhesion coefficient is selected based on the current load, and then the point on that ideal curve that matches the current road surface condition is found to obtain the synchronous adhesion coefficient.
[0113] According to the vehicle control method provided in the embodiments of this application, the synchronous adhesion coefficient corresponding to the current road surface condition is obtained through the ideal curve of the synchronous adhesion coefficient of the vehicle under the current load. The operation is simple and convenient, and it can quickly and accurately obtain the synchronous adhesion coefficient of the vehicle under the current road surface condition and current load. It has high calculation efficiency, can ensure the vehicle's rapid braking response, and improve braking safety.
[0114] In some embodiments, step 120 may further include:
[0115] Based on the synchronous adhesion coefficient, the target braking force distribution coefficients corresponding to the front wheel brake and the rear wheel brake are obtained;
[0116] Based on the target braking force distribution coefficient, adjust the braking force corresponding to the front and rear wheel brakes of the vehicle.
[0117] In this embodiment, the braking force distribution coefficient is the ratio of the braking force of the front brakes to the total braking force of the vehicle, which can be represented by β: β=Ff1 / Ff; Ff=Ff1+Ff2; Ff1=βFf; Ff2=(1-β)Ff;
[0118] Where β is the braking force distribution coefficient; Ff1 is the braking force of the front brake; Ff2 is the braking force of the rear brake; Ff is the total braking force of the brakes; the relationship curve between Ff1 and Ff2 is a straight line that passes through the origin of the coordinate system. This straight line is the braking force distribution line between the front and rear wheel brakes during actual driving, i.e., the β line, as shown in Figure 3.
[0119] The target braking force distribution coefficient is the ratio of the braking force of the front brakes, which enables the front and rear wheels to lock synchronously, to the total braking force of the vehicle when braking on the current road surface and under the current load.
[0120] The intersection of the I-curve and the β-curve represents the ground adhesion coefficient when the front and rear wheels lock up simultaneously, i.e., the synchronous adhesion coefficient. Understandably, continuing to refer to Figure 3, with the current road surface adhesion coefficient... Less than synchronous adhesion coefficient In this case, the β line is located below the I curve, the front wheels lock up first during braking, a "nodding" phenomenon occurs during emergency braking, and danger is likely to occur when decelerating while turning.
[0121] At the current road surface adhesion coefficient Greater than the synchronous adhesion coefficient In this case, the β line is located above the I curve. When braking, the rear wheels lock up first, which can easily cause the rear axle to sideslip and the vehicle to lose directional stability.
[0122] At the current road surface adhesion coefficient Equal to synchronous adhesion coefficient Under certain conditions, this indicates that the front and rear wheels of a vehicle can lock up simultaneously, demonstrating stability.
[0123] As shown in Figure 4, in this application, after obtaining the synchronous adhesion coefficient... Then, the synchronous adhesion coefficient can be found. The corresponding target braking force distribution coefficient β0 is used to distribute braking force and adjust the braking force of the front and rear wheel brakes of the vehicle to achieve vehicle braking and make the front and rear wheels of the vehicle lock up synchronously as much as possible.
[0124] In this case, the target braking force distribution coefficient and the synchronous adhesion coefficient can satisfy the following relationship:
[0125]
[0126] in, β is the synchronous adhesion coefficient; L is the wheelbase; β is the braking force distribution coefficient; b is the distance from the center of mass to the rear axle; h is the height of the center of mass; g is the gravitational acceleration.
[0127] According to the vehicle control method provided in this application embodiment, the target braking force distribution coefficient is obtained by determining the synchronous adhesion coefficient based on the current road conditions and the current load. The target braking force distribution coefficient can be updated in real time based on the actual driving conditions of the vehicle. Thus, the braking force corresponding to the front wheel brakes and rear wheel brakes of the vehicle can be adjusted in real time based on the target braking force distribution coefficient. This allows the vehicle to distribute braking force based on the I curve on any road surface, which has high control real-time performance, control efficiency and control accuracy. It can make the front and rear wheels of the vehicle lock up synchronously as much as possible, improve stability, and thus improve driving safety.
[0128] In some embodiments, step 120 may further include:
[0129] Based on the synchronous adhesion coefficient, the current of the motors corresponding to the front wheel brake and the rear wheel brake is adjusted.
[0130] In this embodiment, it should be noted that the braking force ratio of the front and rear wheel brakes of the vehicle is an adjustable value. For example, the braking force can be adjusted by adjusting the clamping force of the calipers through the drive motor. In actual operation, when braking, the clamping force can be adjusted by controlling the current of the drive motor to adjust the braking force of the wheels based on the current road conditions and the synchronous adhesion coefficient under the current load. This allows for real-time adjustment of the β value, so that the braking force can be distributed in real time based on the I curve regardless of the road surface.
[0131] According to the vehicle control method provided in this application embodiment, the clamping force is adjusted by adjusting the current of the motors corresponding to the front wheel brake and the rear wheel brake based on the synchronous adhesion coefficient, thereby adjusting the braking force corresponding to the front wheel brake and the rear wheel brake of the vehicle. The operation is simple and convenient, and it has high control efficiency and control accuracy. It is applicable to any road conditions and has universality, which can further improve the stability of the vehicle and thus improve braking safety.
[0132] In some embodiments, step 120 may further include:
[0133] Based on the synchronous adhesion coefficient, the target braking force distribution coefficients corresponding to the front wheel brake and the rear wheel brake are obtained;
[0134] The vehicle's electromechanical braking system is adjusted according to the target braking force distribution coefficient.
[0135] In this embodiment, the Electronic Mechanical Brake (EMB) system is a type of brake-by-wire system. The EMB system precisely controls the rotation of the motor through an electronic control unit (ECU), thereby achieving the output of braking force.
[0136] The EMB system includes an EMB controller, an EMB actuator, and sensors. The EMB actuator includes a drive motor, a speed reduction and torque amplification device, and a motion conversion mechanism.
[0137] In actual operation, the braking force of the EMB caliper is achieved by the working clamping of the drive motor. During braking, the braking force of different wheels can be controlled by controlling the clamping force of the drive motor. For example, the clamping force of the drive motor corresponding to the front and rear wheels can be adjusted according to the current target braking force distribution coefficient, thereby adjusting the β value in real time. This allows the braking force to be distributed based on the I curve regardless of the road surface, so as to meet the synchronous lock-up conditions as much as possible.
[0138] In addition, the EMB system can also adjust the braking force of the left and right wheels, making the control more precise and the vehicle more stable.
[0139] According to the vehicle control method provided in this application embodiment, the synchronous adhesion coefficient is updated in real time based on the current road conditions, the current target braking force distribution coefficient is updated accordingly based on the synchronous adhesion coefficient, and the vehicle's electromechanical braking system is adjusted according to the current target braking force distribution coefficient to adjust the clamping force of the motors corresponding to the front wheel brakes and the rear wheel brakes respectively. This allows the braking force to be distributed based on the I curve regardless of the road surface during braking, so as to meet the synchronous lock-up conditions as much as possible. The operation is simple and convenient, and it has high control efficiency and control accuracy, further improving the stability of the vehicle and thus improving braking safety.
[0140] The following explains how to plot the ideal curve of the synchronous adhesion coefficient.
[0141] In some embodiments, the ideal curve of the synchronous adhesion coefficient under the current load can be determined based on the following steps:
[0142] While keeping the vehicle's weight, center of gravity height, distance from center of gravity to rear axle, and wheelbase constant under the current load, obtain the vehicle's synchronous adhesion coefficient under different road conditions.
[0143] Based on the synchronous adhesion coefficients corresponding to various road surface conditions, an ideal curve of the synchronous adhesion coefficient is plotted.
[0144] In this embodiment, the weight under the current load is the total vehicle weight, the height of the center of gravity is the height above the ground, and the wheelbase is the distance between the front and rear axles.
[0145] Figure 2 illustrates a side view of a vehicle, where point O is the center of gravity, a is the distance from the center of gravity to the front axle A, b is the distance from the center of gravity to the rear axle B, l is the wheelbase, and h is the height of the center of gravity. It can be understood that, given the selected vehicle parameters and a fixed weight, the calculated synchronous adhesion coefficient is a constant for the same road surface conditions.
[0146] Once the vehicle's weight and center of gravity are given, for each road surface condition, the front wheel braking force and rear wheel braking force when the front and rear wheels lock up simultaneously can be tested through experiments. Then, the synchronous adhesion coefficient can be calculated, and the points corresponding to each synchronous adhesion coefficient can be connected to obtain the ideal curve of the synchronous adhesion coefficient (I curve), as shown in Figure 3.
[0147] In some embodiments, the synchronous adhesion coefficient can be calculated based on the following formula:
[0148] Among them, F μ2 For rear wheel braking force; F μ1 The front wheel braking force is m; the weight is g; the acceleration due to gravity is g; the wheelbase is L; and the speed of motion is h. g L1 is the height of the center of mass; L2 is the distance from the center of mass to the rear axle.
[0149] The ideal curves for synchronous adhesion coefficients under other loads can be plotted in a similar manner, which will not be elaborated upon here.
[0150] Of course, in other embodiments, the I curve can also be obtained by solving a system of equations based on parameters such as front wheel braking force, rear wheel braking force, weight, distance from center of gravity to rear axle and distance from center of gravity to front axle. In practical applications, the corresponding method can be flexibly selected to draw the ideal curve of synchronous adhesion coefficient based on the actual situation. This application does not limit this.
[0151] According to the vehicle control method provided in the embodiments of this application, by pre-constructing ideal curves of synchronous adhesion coefficients under various loads, it is possible to directly search during vehicle operation, thereby improving processing efficiency and response rate and enhancing driving safety.
[0152] The vehicle control method provided in this application can be executed by a vehicle control device. This application uses the example of a vehicle control device executing the vehicle control method to illustrate the vehicle control device provided in this application.
[0153] This application also provides a vehicle control device.
[0154] As shown in Figure 5, the control device of the vehicle includes: a first processing module 510 and a second processing module 520.
[0155] The first processing module 510 is used to obtain the current road conditions corresponding to the vehicle;
[0156] The second processing module 520 is used to adjust the braking force corresponding to the front wheel brake and the rear wheel brake of the vehicle based on the synchronous adhesion coefficient of the vehicle under the current road conditions and current load, thereby controlling the vehicle to brake.
[0157] According to the vehicle control device provided in the embodiments of this application, the synchronous adhesion coefficient is determined by the current road conditions and current load of the vehicle. Based on the synchronous adhesion coefficient, the braking force distributed between the front and rear brakes of the vehicle is adjusted to control the vehicle braking. This can increase the probability of the front and rear wheels locking up synchronously during braking, thereby improving the stability and braking efficiency of the vehicle, reducing the braking distance, improving driving safety, and is applicable to various road surfaces, thus having universality.
[0158] In some embodiments, the device may further include a third processing module for:
[0159] By querying the ideal curve of the synchronous adhesion coefficient of the vehicle under the current load based on the current road conditions, the synchronous adhesion coefficient corresponding to the current road conditions can be obtained.
[0160] In some embodiments, the device may further include a fourth processing module for:
[0161] While keeping the vehicle's weight, center of gravity height, distance from center of gravity to rear axle, and wheelbase constant under the current load, obtain the vehicle's synchronous adhesion coefficient under different road conditions.
[0162] Based on the synchronous adhesion coefficients corresponding to various road surface conditions, an ideal curve of the synchronous adhesion coefficient is plotted.
[0163] In some embodiments, the second processing module 520 may also be used for:
[0164] Based on the synchronous adhesion coefficient, the target braking force distribution coefficients corresponding to the front wheel brake and the rear wheel brake are obtained;
[0165] Based on the target braking force distribution coefficient, adjust the braking force corresponding to the front and rear wheel brakes of the vehicle.
[0166] In some embodiments, the second processing module 520 may also be used for:
[0167] Based on the synchronous adhesion coefficient, the current of the motors corresponding to the front wheel brake and the rear wheel brake is adjusted.
[0168] In some embodiments, the first processing module 510 may also be used for:
[0169] Obtain the current road surface adhesion coefficient corresponding to the vehicle;
[0170] The current road surface condition is determined based on the current road surface adhesion coefficient.
[0171] In some embodiments, the first processing module 510 may also be used for:
[0172] The current road surface adhesion coefficient is calculated based on the vehicle's wheel speed, braking stroke signal, motor torque, and motor speed.
[0173] In some embodiments, the first processing module 510 may also be used for:
[0174] It identifies environmental images of the vehicle's surroundings captured by image sensors to determine the current road conditions.
[0175] In some embodiments, the first processing module 510 may also be used for:
[0176] Image recognition is performed on the acquired images of the environment around the vehicle, and the first road surface condition is determined based on the image recognition results;
[0177] Based on the vehicle's operating parameters, the current road surface adhesion coefficient corresponding to the vehicle is calculated.
[0178] The current road surface condition is determined based on the first road surface condition and the current road surface adhesion coefficient.
[0179] In some embodiments, the second processing module 520 may also be used for:
[0180] Based on the synchronous adhesion coefficient, the target braking force distribution coefficients corresponding to the front wheel brake and the rear wheel brake are obtained;
[0181] The vehicle's electromechanical braking system is adjusted according to the target braking force distribution coefficient.
[0182] The vehicle control device in this application embodiment can be an electronic device or a component within an electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal or other devices besides a terminal. For example, the electronic device can be a mobile phone, tablet computer, laptop computer, PDA, in-vehicle electronic device, mobile internet device (MID), augmented reality (AR) / virtual reality (VR) device, robot, wearable device, ultra-mobile personal computer (UMPC), netbook, or personal digital assistant (PDA), etc. It can also be a server, network attached storage (NAS), personal computer (PC), television set (TV), ATM, or self-service machine, etc. This application embodiment does not specifically limit the specific device.
[0183] The vehicle control device in this embodiment can be a device with an operating system. This operating system can be Android, iOS, or other possible operating systems; this embodiment does not specifically limit the specific operating system.
[0184] The vehicle control device provided in this application embodiment can implement the various processes implemented in the method embodiments of Figures 1 to 4. To avoid repetition, it will not be described again here.
[0185] This application also provides a vehicle.
[0186] The vehicle includes a braking system that operates based on the vehicle control method described in any of the above embodiments.
[0187] According to the vehicle provided in the embodiments of this application, the synchronous adhesion coefficient is determined by the current road conditions and current load of the vehicle. The braking force distributed between the front and rear brakes of the vehicle is adjusted based on the synchronous adhesion coefficient to control the vehicle braking. This can increase the probability of the front and rear wheels locking up synchronously during braking, thereby improving the stability and braking efficiency of the vehicle, reducing the braking distance, improving driving safety, and is applicable to a variety of road surfaces, thus having universality.
[0188] In some embodiments, the braking system may include an electromechanical braking system.
[0189] Among them, the Electronic Mechanical Brake (EMB) system precisely controls the rotation of the motor through the electronic control unit (ECU), thereby realizing the output of braking force.
[0190] The EMB system includes an EMB controller, an EMB actuator, and sensors. The EMB actuator includes a drive motor, a speed reduction and torque amplification device, and a motion conversion mechanism.
[0191] In actual operation, the braking force of the EMB caliper is achieved by the clamping action of the drive motor. During braking, the braking force of different wheels can be controlled by controlling the clamping force of the drive motor, thereby adjusting the β value in real time. This allows the braking force to be distributed based on the I curve regardless of the road surface.
[0192] In addition, it can also adjust the braking force of the left and right wheels, making the control more precise and the vehicle more stable.
[0193] According to the vehicle provided in the embodiments of this application, by setting up an EMB system, the clamping force of the motors corresponding to the front wheel brake and the rear wheel brake is adjusted according to the synchronous adhesion coefficient to adjust the braking force of the vehicle's front wheel brake and the rear wheel brake. The operation is simple and convenient, and has high control efficiency and control precision, further improving the stability of the vehicle, thereby improving braking safety.
[0194] In some embodiments, as shown in FIG6, this application embodiment also provides an electronic device 600, including a processor 601, a memory 602, and a computer program stored in the memory 602 and executable on the processor 601. When the program is executed by the processor 601, it implements the various processes of the above-described vehicle control method embodiment and can achieve the same technical effect. To avoid repetition, it will not be described again here.
[0195] It should be noted that the electronic devices in the embodiments of this application include mobile electronic devices and non-mobile electronic devices, such as vehicle terminals or smart wearable devices.
[0196] This application also provides a non-transitory computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the various processes of the above-described vehicle control method embodiments and achieves the same technical effect. To avoid repetition, it will not be described again here.
[0197] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.
[0198] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described vehicle control method.
[0199] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.
[0200] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above-described vehicle control method embodiments and can achieve the same technical effect. To avoid repetition, it will not be described again here.
[0201] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.
[0202] 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. Without further limitations, 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. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.
[0203] 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 this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer 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 (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.
[0204] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.
[0205] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0206] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.
Claims
1. A control method of a vehicle, characterized by, The method comprises: acquiring a current road surface condition corresponding to the vehicle; based on the synchronous adhesion coefficient of the vehicle under the current road surface condition and the current load obtained from the current road surface condition, adjusting the braking force corresponding to the front wheel brake and the rear wheel brake of the vehicle, and controlling the vehicle to brake.
2. The control method of a vehicle according to claim 1, characterized by The synchronous adhesion coefficient is determined based on the following steps: querying the synchronous adhesion coefficient ideal curve of the vehicle under the current load through the current road surface condition to obtain the synchronous adhesion coefficient corresponding to the current road surface condition.
3. The control method of a vehicle according to claim 2, characterized by, The synchronous adhesion coefficient ideal curve under the current load is determined based on the following steps: acquiring the synchronous adhesion coefficients corresponding to the vehicle under different road surface conditions while keeping the weight, height of the center of mass, distance from the center of mass to the rear axle, and wheelbase of the vehicle under the current load unchanged; based on the synchronous adhesion coefficients corresponding to each road surface condition, the synchronous adhesion coefficient ideal curve is drawn.
4. The control method of a vehicle according to any one of claims 1 to 3, characterized by The synchronous adhesion coefficient ideal curve under the current load is determined based on the following steps: acquiring the synchronous adhesion coefficients corresponding to the vehicle under different road surface conditions while keeping the weight, the height of the center of mass, the distance from the center of mass to the rear axle, and the wheelbase of the vehicle under the current load unchanged; based on the synchronous adhesion coefficients corresponding to each road surface condition, the synchronous adhesion coefficient ideal curves are drawn. The synchronous adhesion coefficient ideal curve under the current load is determined based on the following methods: based on the synchronous adhesion coefficient, acquiring the target braking force distribution coefficient corresponding to the front wheel brake and the rear wheel brake; 5. The control method of a vehicle according to any one of claims 1 to 4, characterized by based on the target braking force distribution coefficient, adjusting the braking force corresponding to the front wheel brake and the rear wheel brake of the vehicle. The synchronous adhesion coefficient ideal curve under the current load is determined based on the following steps.
6. The control method of a vehicle according to any one of claims 1 to 5, characterized by The synchronous adhesion coefficient ideal curve under the current load is determined based on the following steps: The synchronous adhesion coefficient ideal curve under the current load is determined based on the following steps: based on the wheel speed, brake stroke signal, motor torque, and motor speed of the vehicle, calculating the current road surface adhesion coefficient.
7. The control method of a vehicle according to claim 6, characterized by The synchronous adhesion coefficient ideal curve under the current load is determined based on the following steps. The synchronous adhesion coefficient ideal curve under the current load is determined based on the following steps:
8. The control method of a vehicle according to any one of claims 1 to 5, characterized by identifying the environmental image of the vehicle surrounding area collected by the image sensor to determine the current road surface condition. The synchronous adhesion coefficient ideal curve under the current load is determined by the following steps:
9. The control method of a vehicle according to any one of claims 1 to 5, characterized by performing image recognition on the acquired environmental image of the vehicle surrounding area, and determining a first road surface condition according to the image recognition result; based on the working parameters of the vehicle, calculating the current road surface adhesion coefficient corresponding to the vehicle; based on the first road surface condition and the current road surface adhesion coefficient, determining the current road surface condition. The synchronous adhesion coefficient ideal curve under the current load is determined according to the following steps:
10. The control method of a vehicle according to claim 1, characterized by Based on the synchronous adhesion coefficient, a target brake force distribution coefficient corresponding to the front wheel brake and the rear wheel brake is obtained; According to the target brake force distribution coefficient, an electronic mechanical brake system of the vehicle is adjusted.
11. A control device of a vehicle characterized by comprising: Comprising: A first processing module for obtaining a current road surface condition corresponding to the vehicle; A second processing module for adjusting brake forces corresponding to the front wheel brake and the rear wheel brake of the vehicle based on a synchronous adhesion coefficient of the vehicle under the current road surface condition and a current load obtained from the current road surface condition, so as to control the vehicle to brake.
12. A vehicle characterized by comprising: Comprising: A brake system working based on the control method of the vehicle according to any one of claims 1-10.
13. The vehicle of claim 12, wherein, The brake system comprises an electronic mechanical brake system.