Method and device for determining road adhesion coefficient, storage medium and electronic equipment

Abstract

The embodiment of the application provides a kind of determination method and device of road surface adhesion coefficient, storage medium, electronic equipment, wherein, the method comprises: according to the acceleration of target vehicle collected by sensor, determine the first road surface adhesion coefficient;According to the tractive effort of the target vehicle, determine the second road surface adhesion coefficient, and according to the change information of the target vehicle, determine the weight of the second road surface adhesion coefficient, wherein, the change information at least includes one of the following: throttle pedal opening degree change rate, brake pedal opening degree change rate, yaw angular velocity change rate;According to the first road surface adhesion coefficient, the second road surface adhesion coefficient and the weight of the second road surface adhesion coefficient, determine target road surface adhesion coefficient, solve the problem that the accuracy of road surface adhesion coefficient calculated in the related art is lower.

Description

Technical Field

[0001] This application relates to the field of vehicle control, and more specifically, to a method for determining the road surface adhesion coefficient, a storage medium, and an electronic device. Background Technology

[0002] In the field of vehicle dynamic stability control, the road surface adhesion coefficient is a key parameter that determines a vehicle's braking, driving performance, and handling stability. It directly relates to the maximum friction force that can be transmitted between the tire and the road surface, thus affecting the vehicle's driving safety and handling under different road conditions. Traditionally, the estimation of the road surface adhesion coefficient has relied mainly on empirical formulas or preset road conditions. This method has significant limitations and uncertainties when facing complex and ever-changing real-world road environments.

[0003] With the increasing intelligence of vehicles, the widespread application of onboard sensors such as IMUs (Inertial Measurement Units), wheel speed sensors, and steering wheel angle sensors has made it possible to estimate the road adhesion coefficient in real time and accurately. However, due to the rapidly changing road conditions and the diversity of vehicle operating conditions, relying solely on single sensor information or simple dynamic models for adhesion coefficient estimation often fails to achieve ideal accuracy. During braking or acceleration, vehicles may encounter slippery, icy, or gravel roads. In these situations, the friction between the tires and the road surface will significantly decrease, leading to a reduction in vehicle grip and increasing the risk of loss of control.

[0004] Existing methods for estimating the coefficient of adhesion, such as those based solely on the rate of change of wheel speed, yield low accuracy in obtaining the road surface adhesion coefficient.

[0005] There is currently no effective solution to the problem of low accuracy in the calculated road adhesion coefficient in existing technologies.

[0006] Therefore, it is necessary to improve the relevant technology to overcome the aforementioned defects. Summary of the Invention

[0007] This application provides a method for determining the road surface adhesion coefficient, a storage medium, and an electronic device, to at least solve the problem of low accuracy of the calculated road surface adhesion coefficient in the prior art.

[0008] According to one embodiment of this application, a method for determining the road surface adhesion coefficient is provided, comprising: determining a first road surface adhesion coefficient based on the acceleration of a target vehicle collected by a sensor; determining a second road surface adhesion coefficient based on the traction force of the target vehicle; and determining a weight of the second road surface adhesion coefficient based on change information of the target vehicle, wherein the change information includes at least one of the following: accelerator pedal opening change rate, brake pedal opening change rate, and yaw rate change rate; and determining a target road surface adhesion coefficient based on the weight of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient.

[0009] In an exemplary embodiment, determining a second road surface adhesion coefficient based on the traction force of the target vehicle includes: acquiring the longitudinal ground force, lateral ground force, and vertical ground force of the target vehicle; determining a longitudinal road surface adhesion coefficient based on the longitudinal ground force and the vertical ground force; determining a lateral road surface adhesion coefficient based on the lateral ground force and the vertical ground force; and determining a second road surface adhesion coefficient based on the longitudinal road surface adhesion coefficient and the lateral road surface adhesion coefficient.

[0010] In one exemplary embodiment, obtaining the longitudinal ground force of the target vehicle includes: determining the longitudinal ground force based on the target vehicle's driving torque, braking torque, wheel radius, tire moment of inertia, and wheel angular acceleration.

[0011] In one exemplary embodiment, obtaining the lateral ground force of the target vehicle includes: determining the lateral ground force based on the lateral stiffness and lateral angle of the target vehicle.

[0012] In an exemplary embodiment, determining the longitudinal ground force based on the target vehicle's driving torque, braking torque, wheel radius, tire moment of inertia, and wheel angular acceleration includes: determining the longitudinal ground force F using the following formula. x :

[0013] Among them, T Drv T is the driving torque. Brk Where r is the braking torque, r is the wheel radius, and J is the tire moment of inertia. Let be the angular acceleration of the wheel.

[0014] In an exemplary embodiment, determining the lateral ground force based on the lateral stiffness and lateral angle of the target vehicle includes: determining the lateral ground force F using the following formula. y :

[0015] F y=C·α, where C is the lateral stiffness and α is the lateral angle.

[0016] In an exemplary embodiment, after determining the weight of the second road surface adhesion coefficient based on the change information of the target vehicle, the method further includes: determining whether the target vehicle triggers a target function; if the target vehicle triggers the target function, determining a target road surface adhesion coefficient based on the weight of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient; if the target vehicle does not trigger the target function, determining the rate of change of the acceleration of the target vehicle at a first moment; determining a first magnitude relationship between the rate of change and a preset rate of change; and determining the target road surface adhesion coefficient based on the first magnitude relationship, wherein the first moment is the moment before the current moment has elapsed for a preset duration.

[0017] In an exemplary embodiment, determining the target road surface adhesion coefficient based on the first size relationship includes: when the first size relationship indicates that the rate of change is greater than or equal to the preset rate of change, determining the target road surface adhesion coefficient based on the weights of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient; when the first size relationship indicates that the rate of change is less than the preset rate of change, determining the sum of the road surface adhesion coefficient at the first moment and the preset growth value, and determining the sum as the target road surface adhesion coefficient.

[0018] In an exemplary embodiment, after determining the sum of the road surface adhesion coefficient and the preset growth value at the first moment, the method further includes: determining a second size relationship between the sum and the preset road surface adhesion coefficient; determining the sum as the target road surface adhesion coefficient when the second size relationship indicates that the sum is less than or equal to the preset road surface adhesion coefficient; and determining the preset road surface adhesion coefficient as the target road surface adhesion coefficient when the second size relationship indicates that the sum is greater than the preset road surface adhesion coefficient.

[0019] According to another embodiment of this application, a device for determining the road surface adhesion coefficient is provided, comprising: a first determining module, configured to determine a first road surface adhesion coefficient based on the acceleration of a target vehicle collected by a sensor; a second determining module, configured to determine a second road surface adhesion coefficient based on the traction force of the target vehicle, and to determine a weight of the second road surface adhesion coefficient based on change information of the target vehicle, wherein the change information includes at least one of the following: accelerator pedal opening change rate, brake pedal opening change rate, and yaw rate change rate; and a third determining module, configured to determine a target road surface adhesion coefficient based on the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the weight of the second road surface adhesion coefficient.

[0020] According to yet another embodiment of this application, a computer-readable storage medium is also provided, wherein a computer program is stored therein, and the computer program is configured to perform the steps in any of the above method embodiments when it is run.

[0021] According to yet another embodiment of this application, an electronic device is also provided, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0022] According to yet another embodiment of this application, a computer program product is also provided, including a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0023] This application determines a first road surface adhesion coefficient based on the acceleration of a target vehicle collected by sensors; a second road surface adhesion coefficient based on the traction force of the target vehicle; and a weight for the second road surface adhesion coefficient based on changes in the target vehicle's traction force. The changes in traction force include at least one of the following: accelerator pedal opening rate of change, brake pedal opening rate of change, and yaw rate of change. A target road surface adhesion coefficient is determined based on the weights of the first, second, and third road surface adhesion coefficients. In other words, this application provides a more optimized calculated road surface adhesion coefficient by comprehensively considering acceleration and traction information, adjusting weights based on changes in the target vehicle's traction force, and determining the target road surface adhesion coefficient based on the weights of the first, second, and third road surface adhesion coefficients. Therefore, this application solves the problem of low accuracy in the calculated road surface adhesion coefficient in related technologies. Attached Figure Description

[0024] 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.

[0025] 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.

[0026] Figure 1 This is a hardware structure block diagram of a computer device for a method of determining the road surface adhesion coefficient according to an embodiment of this application;

[0027] Figure 2This is a flowchart of a method for determining the road surface adhesion coefficient according to an embodiment of this application;

[0028] Figure 3 This is a structural block diagram of a device for determining the road surface adhesion coefficient according to an embodiment of this application. Detailed Implementation

[0029] The embodiments of this application will be described in detail below with reference to the accompanying drawings and examples.

[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0031] The methods and embodiments provided in this application can be executed in a computer device or similar computing device. Taking running on a computer device as an example, Figure 1 This is a hardware structure block diagram of a computer device for a method of determining the road surface adhesion coefficient according to an embodiment of this application. Figure 1 As shown, a computer device may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The computer device may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the computer device described above. For example, the computer device may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0032] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the method for determining the road surface adhesion coefficient in this embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to computer devices via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0033] The transmission device 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by a communication provider for the computer equipment. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 may be a Radio Frequency (RF) module used for wireless communication with the Internet.

[0034] This embodiment provides a method for determining the road surface adhesion coefficient. Figure 2 This is a flowchart of a method for determining the road surface adhesion coefficient according to an embodiment of this application, as shown below. Figure 2 As shown, the process includes the following steps:

[0035] Step S202: Determine the first road surface adhesion coefficient based on the acceleration of the target vehicle collected by the sensor;

[0036] In step S202, the first road adhesion coefficient is determined by collecting the lateral and longitudinal acceleration information of the target vehicle using an IMU sensor. The IMU sensor provides dynamic acceleration data of the vehicle during driving, reflecting its dynamic response under different road conditions in real time. Especially when the vehicle experiences transient conditions (such as emergency braking, rapid acceleration, or turning), the IMU sensor can quickly capture changes in the vehicle's state, providing direct evidence of the instantaneous road adhesion. Therefore, the first road adhesion coefficient determined using the first acceleration information can provide high estimation accuracy under transient conditions.

[0037] Optionally, based on the IMU sensor's a x ,a y Signal, calculate the first road surface adhesion coefficient μ sens The calculation formula is as follows:

[0038] Among them, a x , is the longitudinal acceleration, a y is the lateral acceleration signal, and g is the gravitational acceleration.

[0039] Step S204: Determine the second road surface adhesion coefficient based on the traction force of the target vehicle, and determine the weight of the second road surface adhesion coefficient based on the change information of the target vehicle, wherein the change information includes at least one of the following: accelerator pedal opening change rate, brake pedal opening change rate, and yaw rate change rate.

[0040] The second road surface adhesion coefficient is determined based on the target vehicle's primary traction force (i.e., the actual driving or braking force). Simultaneously, the weight of the second road surface adhesion coefficient is determined based on the vehicle's dynamic changes (such as the rate of change of accelerator pedal opening, the rate of change of brake pedal opening, and the rate of change of yaw rate). Traction force information reflects the actual force between the vehicle and the road surface. However, under transient conditions, traction force may lag behind the vehicle's actual state. Therefore, the weight of the second road surface adhesion coefficient is dynamically adjusted based on changing information (indicators reflecting whether the vehicle is in a transient condition). This ensures that under transient conditions, the system relies more on IMU sensor information, while under steady-state conditions, it considers the estimation results based on traction force more, achieving an optimal estimation balance.

[0041] Step S206: Determine the target road surface adhesion coefficient based on the weights of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient.

[0042] Alternatively, the target pavement adhesion coefficient μ can be determined according to the following formula:

[0043] μ = μ mdl *λ+μ sens *(1-λ), where μ mdl λ represents the second road surface adhesion coefficient, and λ is the weight of the second road surface adhesion coefficient.

[0044] Finally, in step S206, the target road surface adhesion coefficient is calculated comprehensively based on the first and second road surface adhesion coefficients obtained in the previous two steps, and the dynamically adjusted weight of the second road surface adhesion coefficient. The importance of information sources is dynamically matched under different working conditions through weight adjustment. Under transient conditions, the weight of IMU sensor information increases due to its immediacy and accuracy; conversely, under steady-state conditions, the weight of the estimation result based on traction force increases. In this way, even when facing complex and changing road conditions, the system can provide a more accurate estimate of the road surface adhesion coefficient that is closer to reality.

[0045] Through the above steps, a first road surface adhesion coefficient is determined based on the acceleration of the target vehicle collected by the sensor; a second road surface adhesion coefficient is determined based on the traction force of the target vehicle; and the weight of the second road surface adhesion coefficient is determined based on the change information of the target vehicle, wherein the change information includes at least one of the following: accelerator pedal opening rate of change, brake pedal opening rate of change, and yaw rate of change; the target road surface adhesion coefficient is determined based on the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the weight of the second road surface adhesion coefficient. That is, in this embodiment, by comprehensively considering acceleration information and traction force information, adjusting the weights based on the change information of the target vehicle, and determining the target road surface adhesion coefficient based on the weight of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient, this embodiment provides a more optimized calculated value for the road surface adhesion coefficient. Therefore, it can solve the problem of low accuracy of the calculated road surface adhesion coefficient in related technologies.

[0046] Optionally, the second road surface adhesion coefficient is determined as follows: the longitudinal ground force, lateral ground force, and vertical ground force of the target vehicle are obtained; the longitudinal road surface adhesion coefficient is determined based on the longitudinal ground force and the vertical ground force; the lateral road surface adhesion coefficient is determined based on the lateral ground force and the vertical ground force; and the second road surface adhesion coefficient is determined based on the longitudinal road surface adhesion coefficient and the lateral road surface adhesion coefficient.

[0047] In this embodiment of the application, it is necessary to collect and analyze the three main ground forces acting on the target vehicle during its driving process: longitudinal ground force (F... x ), lateral ground force (F) y ) and vertical ground force (F) z These forces represent the pushing or pulling force of the vehicle along the direction of travel (such as the force during acceleration or braking), the lateral force perpendicular to the direction of travel (such as the force during turning), and the normal force exerted by the vehicle on the road surface (i.e., the force of gravity).

[0048] Next, utilizing the longitudinal ground action force (F) x ) and the force acting vertically on the ground (F) z To calculate the longitudinal road surface adhesion coefficient (μ) long The longitudinal road adhesion coefficient reflects the ratio of longitudinal friction force to vertical pressure between the tire and the road surface during vehicle acceleration or braking. Its calculation formula is as follows:

[0049] Subsequently, the lateral ground force (F) y ) and the force acting vertically on the ground (F) z ) was used to calculate the transverse road adhesion coefficient (μ) latThe lateral adhesion coefficient measures the ratio of lateral friction to vertical pressure between the tire and the road surface under lateral forces. The formula is as follows: The lateral adhesion coefficient has a decisive impact on the vehicle's handling stability and cornering performance, especially when driving on wet or uneven roads, where the vehicle needs to maintain sufficient lateral grip to avoid skidding or loss of control.

[0050] Finally, the system will calculate the longitudinal road adhesion coefficient (μ). long ) and transverse road surface adhesion coefficient (μ lat By combining these factors, a comprehensive second road surface adhesion coefficient (μ) can be determined.

[0051] Through the above steps, the embodiments of this application can more accurately take into account the dynamic characteristics of the vehicle in different directions and the complex interaction between the vehicle and the road surface, thereby providing a more comprehensive and accurate estimate of the road surface adhesion coefficient. Compared with methods that rely solely on forces in a single direction or simple sensor data, this approach can significantly improve the estimation accuracy of the road surface adhesion coefficient under complex and changing conditions, such as rapid acceleration, sudden braking, or high-speed cornering, providing more reliable data support for the optimization of vehicle dynamic stability control systems and safe vehicle operation.

[0052] Optionally, obtaining the longitudinal ground force of the target vehicle includes: determining the longitudinal ground force based on the target vehicle's driving torque, braking torque, wheel radius, tire moment of inertia, and wheel angular acceleration.

[0053] Specifically, the longitudinal ground force F is determined by the following formula. x :

[0054] Among them, T Drv T is the driving torque. Brk Where r is the braking torque, r is the wheel radius, and J is the tire moment of inertia. Let be the angular acceleration of the wheel.

[0055] Longitudinal ground force (F) x This is the force exerted by a vehicle on the road surface in the forward or backward direction, directly affecting the vehicle's acceleration and braking performance. The magnitude of this force can be determined by analyzing and calculating the target vehicle's driving torque (T). Drv Braking torque (T) Brk Wheel radius (r), tire moment of inertia (J), and wheel angular acceleration To determine.

[0056] Driving torque and braking torque are two main dynamic parameters affecting longitudinal ground forces. Driving torque, provided by the vehicle's engine or electric motor, is the power source propelling the vehicle forward; braking torque, on the other hand, is the torque generated by the braking system during vehicle deceleration or braking. These two parameters are directly related to the longitudinal thrust or pull of the tires on the road surface.

[0057] Wheel radius is a key parameter for converting torque into linear force. In dynamics calculations, the conversion between torque and force must consider the lever principle, that is, torque is converted into a linear force acting on the ground through the wheel radius. Changes in wheel radius directly affect the magnitude of the longitudinal ground force.

[0058] Tire moment of inertia reflects a tire's ability to resist changes in angular acceleration during rotation, and it is related to the tire's structure, materials, and dimensions. During vehicle acceleration or braking, the tire's moment of inertia affects the wheel's angular acceleration, which in turn affects the distribution of the contact force between the tire and the road surface and the magnitude of friction.

[0059] Wheel angular acceleration is a physical quantity that describes how quickly a wheel accelerates or decelerates, directly affecting the dynamic contact state between the tire and the road surface. When calculating longitudinal ground forces, wheel angular acceleration provides immediate feedback on tire behavior under the current vehicle operating conditions. For example, during rapid acceleration, the wheel may generate a large angular acceleration, which changes the frictional characteristics between the tire and the road surface, thus affecting the magnitude of the longitudinal ground forces.

[0060] Optionally, obtaining the lateral ground force of the target vehicle includes: determining the lateral ground force based on the lateral stiffness and lateral angle of the target vehicle.

[0061] Specifically, the lateral ground force F is determined by the following formula. y :

[0062] F y =C·α, where C is the lateral stiffness and α is the lateral angle.

[0063] Lateral stiffness (C) is a physical quantity that describes a tire's ability to resist lateral deformation (i.e., lateral deformation of the tire) when subjected to lateral forces. It reflects the tire's response characteristics to lateral forces. When a tire is subjected to lateral forces, the lateral stiffness determines the degree of lateral deformation of the tire and the magnitude of the resulting lateral friction force. Lateral stiffness is usually related to tire design, material properties, air pressure, and contact area, and is an important parameter for evaluating tire lateral performance.

[0064] Slip angle (α) is the angle between the tire's actual rolling direction and the vehicle's direction of travel. When a vehicle turns or is subjected to lateral forces, the tire deviates from its ideal rolling direction, creating a slip angle. The size of the slip angle directly affects the distribution of lateral forces between the tire and the road surface, thus affecting the vehicle's handling stability and cornering performance. A larger slip angle usually means that the tire is about to reach or has already reached its lateral grip limit, and the vehicle may face the risk of sideslip.

[0065] Based on the lateral stiffness and slip angle, the lateral ground force generated by the tire under lateral stress can be calculated. This calculation is based on tire slip theory, in which there is a non-linear relationship between the lateral force of the tire and the slip angle, and the lateral stiffness describes the slope of this relationship. The relationship between the lateral ground force and the slip angle and lateral stiffness can be expressed by the formula: F y =C·α. This means that the larger the slip angle, the greater the lateral force generated by the tire; and the greater the lateral stiffness, the greater the lateral force the tire will generate at the same slip angle, indicating that the tire can provide stronger lateral grip.

[0066] Optionally, after determining the weight of the second road surface adhesion coefficient based on the change information of the target vehicle, the method further includes: determining whether the target vehicle triggers the target function; if the target vehicle triggers the target function, determining the target road surface adhesion coefficient based on the weight of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient; if the target vehicle does not trigger the target function, determining the rate of change of the target vehicle's acceleration at a first moment; determining a first magnitude relationship between the rate of change and a preset rate of change; and determining the target road surface adhesion coefficient based on the first magnitude relationship, wherein the first moment is the moment before the current moment has elapsed for a preset duration.

[0067] Check if the target vehicle has triggered specific vehicle stability control functions, such as ABS (Anti-lock Braking System) or TCS (Traction Control System). The triggering of these functions typically indicates that the vehicle is experiencing highly dynamic conditions, such as tire slippage or impending slippage. In these situations, the system needs to rely on more immediate and sensitive information sources to estimate the coefficient of friction.

[0068] When the target vehicle triggers the aforementioned stability control function, the system will comprehensively determine the final target road surface adhesion coefficient based on the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the weight of the second road surface adhesion coefficient, using a formula or algorithm. When functions such as ABS or TCS are triggered, the vehicle may be at the critical point of the adhesion coefficient. At this time, real-time sensor information (such as IMU data) and estimation results based on vehicle dynamics (such as estimation based on traction force) will be comprehensively considered to obtain a more accurate adhesion coefficient estimate that better reflects the current operating conditions.

[0069] If the target vehicle does not trigger any stability control functions, the system will consider the vehicle's rate of acceleration change at the "first moment" (i.e., a preset time before the current moment) and compare it with a preset rate of change to determine the first magnitude relationship. The rate of acceleration change reflects the intensity of the vehicle's dynamic response. By comparing it with a preset threshold, the system can determine whether the vehicle is in a stable driving state. If the rate of change exceeds the preset value, it indicates that the vehicle is experiencing a transient condition, and the system may place more emphasis on the first road adhesion coefficient (based on instantaneous data from sensors). Conversely, in a stable driving state, it will consider the second road adhesion coefficient (based on steady-state data from a dynamic model).

[0070] Finally, based on the first relationship between the rate of change of acceleration and the preset rate of change, the combined ratio of the first road surface adhesion coefficient and the second road surface adhesion coefficient is dynamically adjusted to determine the target road surface adhesion coefficient. This dynamic adjustment mechanism ensures that the system can provide an accurate estimate of the adhesion coefficient reflecting the actual road surface conditions under different vehicle operating conditions, thus providing a reliable basis for the dynamic stability control of the vehicle.

[0071] Optionally, determining the target road surface adhesion coefficient based on the first size relationship includes: when the first size relationship indicates that the rate of change is greater than or equal to the preset rate of change, determining the target road surface adhesion coefficient based on the weights of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient; when the first size relationship indicates that the rate of change is less than the preset rate of change, determining the sum of the road surface adhesion coefficient at the first moment and the preset growth value, and determining the sum as the target road surface adhesion coefficient.

[0072] The target vehicle's acceleration change rate (an instantaneous indicator reflecting the vehicle's dynamic performance) is compared with a preset change rate to determine which method to use to calculate the target road surface adhesion coefficient. The preset change rate is a threshold used to distinguish whether the vehicle is experiencing transient conditions or steady-state driving.

[0073] When the rate of change of the target vehicle's acceleration is greater than or equal to the preset rate of change, it means that the vehicle is experiencing intense dynamic changes, such as rapid acceleration, sudden braking, or fast cornering. In this case, the system's estimation strategy will place greater emphasis on using a weighted average of the first and second road surface adhesion coefficients to more accurately reflect the vehicle's road surface adhesion characteristics under transient conditions.

[0074] Conversely, if the rate of change of the target vehicle's acceleration is less than the preset rate of change, this usually means that the vehicle is driving in a steady state, such as driving at a constant speed in a straight line or turning slowly. Under such steady-state conditions, the system will adjust based on the road adhesion coefficient at the first moment (i.e., the result of the previous estimation cycle) by adding a preset increment value (reflecting the possible small changes in the road adhesion coefficient under steady-state driving conditions) to determine the target road adhesion coefficient.

[0075] The preset growth value is a key parameter that reflects the system's expectation of changes in the road adhesion coefficient. Under steady-state driving conditions, if road conditions change slightly (e.g., from slightly slippery to dry), the preset growth value helps the system adjust its estimate of the road adhesion coefficient in a timely manner to adapt to the change in road conditions. This value is finely adjusted through calibration and verification processes.

[0076] Optionally, after determining the sum of the road surface adhesion coefficient and the preset growth value at the first moment, the method further includes: determining a second size relationship between the sum and the preset road surface adhesion coefficient; if the second size relationship indicates that the sum is less than or equal to the preset road surface adhesion coefficient, determining the sum as the target road surface adhesion coefficient; if the second size relationship indicates that the sum is greater than the preset road surface adhesion coefficient, determining the preset road surface adhesion coefficient as the target road surface adhesion coefficient.

[0077] After calculating the sum of the road adhesion coefficient at the first moment and the preset growth value, the system further compares this sum with the preset road adhesion coefficient. The preset road adhesion coefficient is usually set based on vehicle design parameters, road type, and environmental conditions, representing a reasonable maximum estimate of the adhesion coefficient under specific conditions. This comparison process helps the system verify the reasonableness of the sum and prevents overestimation of the adhesion coefficient due to instantaneous measurement errors or algorithm fluctuations.

[0078] When the sum is less than or equal to the preset road adhesion coefficient, it indicates that the estimated road adhesion coefficient, adjusted according to the vehicle's current operating conditions and road surface conditions, falls within a reasonable range. In this case, the system will directly use the sum as the target road adhesion coefficient to reflect the latest state of the vehicle's dynamic performance and road adhesion characteristics.

[0079] However, if the sum is greater than the preset road adhesion coefficient, it may mean that the sum is greater than a reasonable estimate of the maximum adhesion coefficient. In this case, the system will use the preset road adhesion coefficient as the target road adhesion coefficient to avoid misleading the vehicle control strategy.

[0080] To better understand the process of determining the road surface adhesion coefficient described above, the implementation flow of the method for determining the road surface adhesion coefficient will be further explained below with reference to optional embodiments, but this is not intended to limit the technical solution of the embodiments of this application.

[0081] This embodiment provides a method for determining the road surface adhesion coefficient, which includes the following steps:

[0082] Step 1: Process IMU sensor information;

[0083] The IMU sensor provides lateral and longitudinal acceleration signals (a x ,a y The lower limit μ of the road adhesion coefficient under the current operating conditions of the vehicle is determined by calculation. sens (Equivalent to the first road surface adhesion coefficient in the above embodiment). This initial estimate serves as the benchmark for subsequent road surface adhesion coefficient calculations, ensuring that the algorithm considers the lowest adhesion state under any conditions. The specific formula is as follows:

[0084] Among them, a x For longitudinal acceleration, a y denoted as lateral acceleration, and g is the acceleration due to gravity.

[0085] Step 2: Estimate the road adhesion coefficient μ based on the dynamic model mdl (equivalent to the second road surface adhesion coefficient in the above embodiment);

[0086] When the vehicle is driving or braking, fully utilize the principles of dynamics, combined with the driving torque (T) Drv Braking torque (T) Brk Wheel radius (r), tire moment of inertia (J), wheel angular acceleration Based on key parameters such as these, the actual road adhesion coefficient utilized by the vehicle is estimated. The specific formula is as follows:

[0087]

[0088] Among them, T Drv For driving torque, T Brk For braking torque, F x The longitudinal force is the ground force, F. z The force is perpendicular to the ground, r is the wheel radius, and J is the tire's moment of inertia. It is the wheel angular acceleration, F y The force acting on the lateral ground is C, the lateral stiffness is α, the lateral angle is μ. long It is the longitudinal road surface adhesion coefficient, μ lat It is the lateral road surface adhesion coefficient.

[0089] Step 3: Multi-source data fusion strategy;

[0090] To maintain high accuracy in estimating the road adhesion coefficient under both transient and steady-state conditions, this technical solution cleverly integrates sensor information and dynamic model estimation results. Based on vehicle dynamic parameters such as the rate of change of accelerator pedal opening, the rate of change of brake pedal opening, and the rate of change of yaw rate, a weighting coefficient (λ) is obtained through a lookup table, achieving intelligent combination of the two data sources. The specific formula is as follows:

[0091] μ = μ mdl *λ+μ sens *(1-λ).

[0092] Step 4: Determine the vehicle's stability status;

[0093] When vehicle stability control functions such as ABS (Anti-lock Braking System) and TCS (Traction Control System) are activated, the system determines that the vehicle is experiencing a high-dynamic condition. At this time, the currently estimated road surface adhesion coefficient is regarded as the peak road surface adhesion coefficient, that is, the maximum adhesion capacity that the vehicle can utilize. This state judgment provides a basis for temporarily improving the response speed and safety threshold of the vehicle dynamic control strategy, effectively avoiding the risk of loss of control under extreme driving conditions.

[0094] Step 5: Dynamic compensation mechanism for road surface adhesion coefficient;

[0095] Without ABS or TCS activation, i.e., when the vehicle is not in a non-extreme driving state, the system assesses vehicle stability by analyzing the derivative of wheel acceleration (Jerk). When the Jerk value is below a preset threshold (parameter calibration), it indicates that the vehicle is driving stably. At this point, the algorithm adds a compensation value (offset) to the previous road adhesion coefficient estimate to reflect the vehicle's gradual adaptation to and utilization of road adhesion performance. Furthermore, if the vehicle has been driving smoothly for a certain distance (parameter calibration), the system automatically resets the road adhesion coefficient to its maximum value, indicating that the vehicle is now driving on a high-adhesion road surface.

[0096] The technical solution in this application embodiment can not only monitor and estimate the road surface adhesion coefficient in real time, but also intelligently adjust the estimation strategy according to the dynamic changes of the vehicle, ensuring that the algorithm can always provide accurate and reliable road surface adhesion characteristic information in complex and ever-changing driving environments, thereby improving vehicle driving safety and handling stability.

[0097] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to 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 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, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0098] This embodiment also provides a device for determining the road surface adhesion coefficient, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0099] Figure 3 This is a structural block diagram of a road surface adhesion coefficient determination device according to an embodiment of this application, such as... Figure 3 As shown, the device includes:

[0100] The first determining module 32 is used to determine the first road surface adhesion coefficient based on the acceleration of the target vehicle collected by the sensor;

[0101] The second determining module 34 is used to determine the second road surface adhesion coefficient based on the traction force of the target vehicle, and to determine the weight of the second road surface adhesion coefficient based on the change information of the target vehicle, wherein the change information includes at least one of the following: accelerator pedal opening change rate, brake pedal opening change rate, and yaw rate change rate.

[0102] The third determining module 36 is used to determine the target road surface adhesion coefficient based on the weights of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient.

[0103] Using the aforementioned device, a first road surface adhesion coefficient is determined based on the acceleration of the target vehicle collected by sensors; a second road surface adhesion coefficient is determined based on the traction force of the target vehicle; and the weight of the second road surface adhesion coefficient is determined based on the change information of the target vehicle, wherein the change information includes at least one of the following: accelerator pedal opening rate of change, brake pedal opening rate of change, and yaw rate of change; the target road surface adhesion coefficient is determined based on the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the weight of the second road surface adhesion coefficient. That is, in this embodiment, by comprehensively considering acceleration information and traction force information, adjusting the weights based on the change information of the target vehicle, and determining the target road surface adhesion coefficient based on the weight of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient, this embodiment provides a more optimized calculated value for the road surface adhesion coefficient. Therefore, it can solve the problem of low accuracy of the calculated road surface adhesion coefficient in related technologies.

[0104] In an exemplary embodiment, the second determining module 34 is configured to acquire the longitudinal ground force, the lateral ground force, and the vertical ground force of the target vehicle; determine the longitudinal road surface adhesion coefficient based on the longitudinal ground force and the vertical ground force; determine the lateral road surface adhesion coefficient based on the lateral ground force and the vertical ground force; and determine the second road surface adhesion coefficient based on the longitudinal road surface adhesion coefficient and the lateral road surface adhesion coefficient.

[0105] In one exemplary embodiment, the second determining module 34 is configured to determine the longitudinal ground force based on the target vehicle's driving torque, braking torque, wheel radius, tire moment of inertia, and wheel angular acceleration.

[0106] In one exemplary embodiment, the second determining module 34 is configured to determine the lateral ground force based on the lateral stiffness and lateral angle of the target vehicle.

[0107] In one exemplary embodiment, the second determining module 34 is configured to determine the longitudinal ground force F using the following formula. x :

[0108] Among them, T Drv T is the driving torque. Brk Where r is the braking torque, r is the wheel radius, and J is the tire moment of inertia. Let be the angular acceleration of the wheel.

[0109] In one exemplary embodiment, the second determining module 34 is configured to determine the lateral ground force F using the following formula. y :

[0110] F y =C·α, where C is the lateral stiffness and α is the lateral angle.

[0111] In an exemplary embodiment, the third determining module 36 is configured to determine whether the target vehicle triggers the target function; if the target vehicle triggers the target function, determine the target road surface adhesion coefficient based on the weights of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient; if the target vehicle does not trigger the target function, determine the rate of change of the target vehicle's acceleration at a first moment; determine a first magnitude relationship between the rate of change and a preset rate of change; and determine the target road surface adhesion coefficient based on the first magnitude relationship, wherein the first moment is the moment before the current moment has elapsed for a preset duration.

[0112] In an exemplary embodiment, the third determining module 36 is configured to determine a target road surface adhesion coefficient based on the weights of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient when the first size relationship indicates that the rate of change is greater than or equal to the preset rate of change; and to determine the sum of the road surface adhesion coefficient at the first moment and the preset growth value when the first size relationship indicates that the rate of change is less than the preset rate of change, and to determine the sum as the target road surface adhesion coefficient.

[0113] In an exemplary embodiment, the third determining module 36 is configured to determine a second magnitude relationship between the sum and a preset road surface adhesion coefficient; if the second magnitude relationship indicates that the sum is less than or equal to the preset road surface adhesion coefficient, the sum is determined as the target road surface adhesion coefficient; if the second magnitude relationship indicates that the sum is greater than the preset road surface adhesion coefficient, the preset road surface adhesion coefficient is determined as the target road surface adhesion coefficient.

[0114] It should be noted that the above modules can be implemented by software or hardware. For the latter, they can be implemented in the following ways, but are not limited to: all the above modules are located in the same processor; or, the above modules are located in different processors in any combination.

[0115] Embodiments of this application also provide a computer-readable storage medium storing a computer program, wherein the computer program is configured to execute the steps in any of the above method embodiments when run.

[0116] Optionally, in this embodiment, the storage medium may be configured to store program code for performing the following steps:

[0117] S1, determine the first road surface adhesion coefficient based on the acceleration of the target vehicle collected by the sensor;

[0118] S2, determine the second road surface adhesion coefficient based on the traction force of the target vehicle, and determine the weight of the second road surface adhesion coefficient based on the change information of the target vehicle, wherein the change information includes at least one of the following: accelerator pedal opening change rate, brake pedal opening change rate, yaw rate change rate.

[0119] S3, determine the target road surface adhesion coefficient based on the weights of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient.

[0120] In one exemplary embodiment, the aforementioned computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard disk, magnetic disk, or optical disk.

[0121] Embodiments of this application also provide an electronic device, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0122] In one exemplary embodiment, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0123] Optionally, in this embodiment, the processor can be configured to perform the following steps via a computer program:

[0124] S1, determine the first road surface adhesion coefficient based on the acceleration of the target vehicle collected by the sensor;

[0125] S2, determine the second road surface adhesion coefficient based on the traction force of the target vehicle, and determine the weight of the second road surface adhesion coefficient based on the change information of the target vehicle, wherein the change information includes at least one of the following: accelerator pedal opening change rate, brake pedal opening change rate, yaw rate change rate.

[0126] S3, determine the target road surface adhesion coefficient based on the weights of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient.

[0127] Embodiments of this application also provide a computer program product, which includes a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0128] Embodiments of this application also provide another computer program product, including a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0129] Embodiments of this application also provide a computer program that includes computer instructions stored in a computer-readable storage medium; a processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the steps in any of the above method embodiments.

[0130] Optionally, in this embodiment, the processor can be configured to perform the following steps via a computer program:

[0131] S1, determine the first road surface adhesion coefficient based on the acceleration of the target vehicle collected by the sensor;

[0132] S2, determine the second road surface adhesion coefficient based on the traction force of the target vehicle, and determine the weight of the second road surface adhesion coefficient based on the change information of the target vehicle, wherein the change information includes at least one of the following: accelerator pedal opening change rate, brake pedal opening change rate, yaw rate change rate.

[0133] S3, determine the target road surface adhesion coefficient based on the weights of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient.

[0134] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0135] Obviously, those skilled in the art should understand that the modules or steps of this application described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented here, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, this application is not limited to any particular combination of hardware and software.

[0136] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A method for determining the road surface adhesion coefficient, characterized in that, include: The first road surface adhesion coefficient is determined based on the acceleration of the target vehicle collected by the sensor; The second road surface adhesion coefficient is determined based on the traction force of the target vehicle, and the weight of the second road surface adhesion coefficient is determined based on the change information of the target vehicle, wherein the change information includes at least one of the following: accelerator pedal opening change rate, brake pedal opening change rate, and yaw rate change rate. The target road surface adhesion coefficient is determined based on the weights of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient.

2. The method according to claim 1, characterized in that, Determining the second road surface adhesion coefficient based on the traction force of the target vehicle includes: The longitudinal ground force, lateral ground force, and vertical ground force of the target vehicle are obtained; The longitudinal road surface adhesion coefficient is determined based on the longitudinal ground force and the vertical ground force. The transverse road surface adhesion coefficient is determined based on the transverse ground force and the vertical ground force. The second road surface adhesion coefficient is determined based on the longitudinal road surface adhesion coefficient and the transverse road surface adhesion coefficient.

3. The method according to claim 2, characterized in that, Obtaining the longitudinal ground force of the target vehicle includes: The longitudinal ground force is determined based on the target vehicle's driving torque, braking torque, wheel radius, tire moment of inertia, and wheel angular acceleration. Obtaining the lateral ground force of the target vehicle includes: The lateral ground force is determined based on the lateral stiffness and lateral angle of the target vehicle.

4. The method according to claim 3, characterized in that, The longitudinal ground force is determined based on the target vehicle's driving torque, braking torque, wheel radius, tire moment of inertia, and wheel angular acceleration, including: The longitudinal ground force F is determined by the following formula. x : Among them, T Drv T is the driving torque. Brk Where r is the braking torque, r is the wheel radius, and J is the tire moment of inertia. The wheel angular acceleration; The lateral ground force is determined based on the lateral stiffness and lateral angle of the target vehicle, including: The lateral ground force F is determined by the following formula. y : F y =C·α, where C is the lateral stiffness and α is the lateral angle.

5. The method according to claim 1, characterized in that, After determining the weight of the second road surface adhesion coefficient based on the change information of the target vehicle, the method further includes: Determine whether the target vehicle has triggered the target function; When the target vehicle triggers the target function, the target road adhesion coefficient is determined according to the weights of the first road adhesion coefficient, the second road adhesion coefficient, and the second road adhesion coefficient. If the target vehicle does not trigger the target function, determine the rate of change of the target vehicle's acceleration at a first moment; determine a first magnitude relationship between the rate of change and a preset rate of change; determine the target road surface adhesion coefficient based on the first magnitude relationship, wherein the first moment is the moment before the current moment has elapsed for a preset time.

6. The method according to claim 5, characterized in that, Determining the target road surface adhesion coefficient based on the first size relationship includes: When the first size relationship indicates that the rate of change is greater than or equal to the preset rate of change, the target road surface adhesion coefficient is determined according to the weights of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient. When the first size relationship indicates that the rate of change is less than the preset rate of change, the sum of the road surface adhesion coefficient at the first moment and the preset growth value is determined, and the sum is determined as the target road surface adhesion coefficient.

7. The method according to claim 6, characterized in that, After determining the sum of the road surface adhesion coefficient at the first moment and the preset growth value, the method further includes: Determine the second magnitude relationship between the sum and the preset road surface adhesion coefficient; When the second size relationship indicates that the sum is less than or equal to the preset road surface adhesion coefficient, the sum is determined as the target road surface adhesion coefficient; If the second size relationship indicates that the sum is greater than the preset road surface adhesion coefficient, the preset road surface adhesion coefficient is determined as the target road surface adhesion coefficient.

8. A device for determining the road surface adhesion coefficient, characterized in that, include: The first determining module is used to determine the first road surface adhesion coefficient based on the acceleration of the target vehicle collected by the sensor. The second determining module is used to determine the second road surface adhesion coefficient based on the traction force of the target vehicle, and to determine the weight of the second road surface adhesion coefficient based on the change information of the target vehicle, wherein the change information includes at least one of the following: accelerator pedal opening change rate, brake pedal opening change rate, and yaw rate change rate. The third determining module is used to determine the target road surface adhesion coefficient based on the weights of the first road surface adhesion coefficient, the second road surface adhesion coefficient, and the second road surface adhesion coefficient.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein the program, when executed, performs the method of any one of claims 1 to 7.

10. An electronic device comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to execute the method of any one of claims 1 to 7 through the computer program.

Images