Tire steady-state vertical load identification calculation method, device and equipment and storage medium

Abstract

The application discloses a tire steady-state vertical load identification calculation method, device and equipment and a storage medium. The application obtains vehicle signals of a target vehicle in a driving process, monitors and identifies running conditions of the target vehicle at each moment in real time, judges whether the running conditions meet preset conditions according to the vehicle signals, calculates tire steady-state vertical loads of the target vehicle at corresponding moments in real time according to the vehicle parameters and the vehicle signals when the running conditions meet the preset conditions, the whole process is free of complex operations, has good real-time performance, does not need to add wireless transmission equipment in the wheels, even does not need to add sensors, has high reliability and low application cost.

Description

Technical Field

[0001] This invention relates to the field of automotive engineering technology, and in particular to a method, apparatus, device, and storage medium for identifying and calculating steady-state vertical loads on tires. Background Technology

[0002] The forces and torques between the tires and the ground directly determine the vehicle's motion. In other words, the stress state of the tires determines the vehicle's handling, comfort, and safety. Currently, tire pressure monitoring systems (TPMS) are available, but they don't provide real-time information about the stress state between the tire and the ground.

[0003] With the development of vehicle electrification and intelligence, the determination of vehicle motion states places higher demands on the real-time monitoring of tire force states. For example, the development of electric vehicles allows for greater freedom in the distribution of driving force between the front and rear axles and even the power distribution to each wheel. The magnitude of the tire vertical load directly determines the limit of wheel-road adhesion, which in turn directly determines the output limit of the wheel's driving force. Therefore, real-time and intelligent distribution of driving force requires real-time detection and calculation of the tire's steady-state vertical load. Similarly, real-time intelligent distribution of braking force also requires sensing the tire's steady-state vertical load. Furthermore, the tire vertical load is also an important input for vehicle dynamics system parameter identification or vehicle dynamic control. Currently, the detection or monitoring of tire vertical load requires the installation of numerous expensive sensors on the vehicle tires, involves a large amount of data during measurement, and involves complex or computationally intensive calculations with low real-time performance.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main objective of this invention is to provide a method, apparatus, device, and storage medium for identifying and calculating steady-state vertical loads on tires. This invention aims to solve the technical problems in the prior art where measuring tire vertical loads requires installing numerous expensive sensors and wireless transmission devices on vehicle tires, involves a large amount of data during the measurement process, and results in complex calculations and low real-time performance.

[0006] To achieve the above objectives, the present invention provides a method for identifying and calculating the steady-state vertical load of a tire, the method comprising the following steps:

[0007] Acquire vehicle signals and vehicle parameters of the target vehicle during operation;

[0008] Monitor and identify the operating conditions of the target vehicle at various times;

[0009] Determine whether the operating condition meets the preset conditions based on the vehicle signal;

[0010] When the operating conditions meet the preset conditions, the steady-state vertical load of the target vehicle tires at the corresponding moment is calculated in real time based on the vehicle signals and vehicle parameters.

[0011] Optionally, the vehicle parameters include the wheel weight of the target vehicle in an unloaded and prepared state, the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushing transferred to the wheel end, the characteristic data of the damper damping force - the relative motion speed of the damper, the leverage ratio of the damper relative to the wheel, the unsprung mass of each suspension of the vehicle, and the unsprung mass of each suspension of the vehicle.

[0012] The step of calculating the steady-state vertical load of the target vehicle tires at the corresponding moment based on the vehicle signals and vehicle parameters includes:

[0013] Extract the dynamic displacement of the wheels relative to the target vehicle body from the vehicle signal;

[0014] Based on the target vehicle's wheel weight when it is in an unloaded and ready state, the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushing transferred to the wheel end, the characteristic data of the damper damping force - the damper relative motion speed, the leverage ratio of the damper relative to the wheel, the unsprung mass of each suspension of the vehicle, and the dynamic displacement of the wheel relative to the target vehicle body, the steady-state vertical load of the target vehicle's tires at the corresponding moment is calculated in real time.

[0015] Optionally, the step of calculating the steady-state vertical load of the target vehicle's tires in real time based on the wheel weight, stiffness of each elastic component, leverage ratio of each elastic component relative to the wheel, total stiffness of the suspension link bushings transferred to the wheel end, characteristic data of the damper damping force-dampening force relative to the damper's motion speed, leverage ratio of the damper relative to the wheel, unsprung mass of each suspension component of the vehicle, and dynamic displacement of the wheel relative to the target vehicle body includes:

[0016] Based on the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel, and the equivalent stiffness of the suspension bushing at the wheel end, calculate the equivalent total stiffness of all elastic components of the corresponding suspension at the wheel end.

[0017] The equivalent total stiffness of all the elastic components of the suspension at the wheel end and the dynamic displacement of the wheel relative to the target vehicle body are used to calculate in real time the equivalent load change of all the elastic components of the suspension at the wheel end relative to the unloaded and ready state at the corresponding moment.

[0018] The suspension load-displacement curve data is obtained through suspension K&C characteristic simulation calculation or actual measurement of the vehicle. Based on the dynamic displacement of the wheel relative to the target vehicle body, the equivalent load change at the wheel end of all elastic components of the suspension at the corresponding moment is retrieved from the suspension load-displacement curve data relative to the unloaded and ready state. The suspension load-displacement curve data represents the equivalent load change at the wheel end of all elastic components corresponding to the dynamic displacement of the wheel relative to the target vehicle body in the unloaded and ready state.

[0019] The relative velocity of the wheel relative to the target vehicle body is obtained by differential calculation based on the dynamic displacement of the wheel relative to the target vehicle body;

[0020] The relative motion speed of the shock absorber when it is activated is calculated based on the relative motion speed of the wheel relative to the target vehicle body and the lever ratio of the shock absorber relative to the wheel.

[0021] Based on the relative motion speed of the damper during operation, the damper damping force and damper operation relative velocity database are retrieved to obtain the real-time damping force of the damper.

[0022] The equivalent dynamic load of the damping force of the shock absorber at the wheel end is calculated based on the real-time damping force of the shock absorber and the lever ratio of the shock absorber relative to the wheel.

[0023] The steady-state vertical load of the target vehicle's tires at the corresponding moment is calculated in real time based on the wheel weight of the target vehicle in an unloaded and ready state, the equivalent load change of all elastic components of the suspension at the wheel end relative to the unloaded and ready state, and the equivalent dynamic load of the shock absorber at the wheel end.

[0024] Optionally, determining whether the operating condition meets preset conditions based on the vehicle signal includes:

[0025] The dynamic stroke of the shock absorber when it is in motion is calculated based on the dynamic displacement of the wheel relative to the target vehicle body and the lever ratio of the shock absorber relative to the wheel center in the vehicle signal.

[0026] The relative velocity of the damper during operation can be obtained by differentiating its dynamic stroke.

[0027] Based on the dynamic stroke of the shock absorber and the relative speed of the shock absorber during operation, a preset "road condition - shock absorber dynamic stroke - shock absorber operating speed - vehicle speed" MAP is retrieved to identify the road conditions of the target vehicle during its operation;

[0028] The actual vehicle speed is obtained, and based on the actual vehicle speed and the road conditions during the target vehicle's driving process, the preset "Shock absorber dynamic travel threshold - road conditions - vehicle speed" MAP and "Shock absorber relative motion speed threshold - road conditions - vehicle speed" MAP are retrieved to determine the shock absorber dynamic travel threshold and shock absorber actuation speed threshold.

[0029] When the dynamic stroke of the shock absorber is less than the dynamic stroke threshold and the operating speed of the shock absorber is less than the operating speed threshold, the operating condition is determined to meet the preset conditions.

[0030] Optionally, determining whether the operating condition meets preset conditions based on the vehicle signal includes:

[0031] The brake pedal opening, accelerator pedal opening, and longitudinal acceleration in the vehicle signals are calculated by differentiation to obtain the rate of change of brake pedal opening, the rate of change of accelerator pedal opening, and the rate of change of longitudinal acceleration.

[0032] When the rate of change of the brake pedal opening is less than a preset threshold for the rate of change of the brake pedal opening, or the rate of change of the accelerator pedal opening is less than a preset threshold for the rate of change of the accelerator pedal opening, or the rate of change of the longitudinal acceleration is less than a threshold for the rate of change of the longitudinal acceleration, the operating condition is determined to meet the preset conditions.

[0033] Optionally, determining whether the operating condition meets preset conditions based on the vehicle signal further includes:

[0034] The brake master cylinder pressure and accelerator pedal voltage in the vehicle signal are respectively differentiated to obtain the brake master cylinder pressure change rate and accelerator pedal voltage change rate.

[0035] When the rate of change of the brake master cylinder pressure is less than a preset threshold for the rate of change of the brake master cylinder pressure, or when the rate of change of the accelerator pedal voltage is less than a preset threshold for the rate of change of the accelerator pedal voltage, the operating condition is determined to meet the preset conditions.

[0036] Optionally, determining whether the operating condition meets preset conditions based on the vehicle signal includes:

[0037] The steering wheel angle and lateral acceleration in the vehicle signal are differentiated and calculated to obtain the rate of change of steering wheel angular velocity and lateral acceleration.

[0038] The steering wheel angular velocity threshold is obtained by looking up the preset "steering wheel angular velocity threshold - vehicle speed" data table. When the steering wheel angular velocity is less than the angular velocity threshold, or the lateral acceleration change rate is less than the lateral acceleration change rate threshold, the operating condition is determined to meet the preset conditions.

[0039] Furthermore, to achieve the above objectives, the present invention also proposes a tire steady-state vertical load identification and calculation device, the tire steady-state vertical load identification and calculation device comprising:

[0040] The reading module is used to acquire vehicle signals and vehicle parameters of the target vehicle during operation.

[0041] The monitoring module is used to monitor and identify the operating conditions of the target vehicle at various times.

[0042] The judgment module is used to determine whether the operating condition meets preset conditions based on the vehicle signal.

[0043] The calculation module is used to calculate the steady-state vertical load of the target vehicle tires in real time based on the vehicle signals and vehicle parameters when the operating conditions meet the preset conditions.

[0044] Furthermore, to achieve the above objectives, the present invention also proposes a tire steady-state vertical load identification and calculation device, which includes: a memory, a processor, and a tire vertical load identification and calculation program stored in the memory and running on the processor. The tire vertical load identification and calculation program is configured to implement the tire steady-state vertical load identification and calculation method as described above.

[0045] Furthermore, to achieve the above objectives, the present invention also proposes a storage medium storing a tire vertical load identification and calculation program, which, when executed by a processor, implements the tire steady-state vertical load identification and calculation method as described above.

[0046] This invention acquires vehicle signals and parameters of a target vehicle during its driving process, and monitors and identifies the operating conditions of the target vehicle at various times in real time. Based on the vehicle signals and parameters, it determines whether the operating conditions meet preset conditions. When the vehicle signals of the operating conditions meet the preset conditions, it calculates the steady-state vertical load of the target vehicle's tires at the corresponding time in real time based on the vehicle parameters and vehicle signals. The entire process involves no complex calculations, has good real-time performance, and can be implemented without adding wireless transmission devices or even additional sensors to the wheels. It is highly reliable and has low application costs. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the tire steady-state vertical load identification and calculation device in the hardware operating environment of the embodiment of the present invention;

[0048] Figure 2 This is a flowchart illustrating the first embodiment of the tire steady-state vertical load identification and calculation method of the present invention;

[0049] Figure 3 This is a flowchart illustrating the second embodiment of the tire steady-state vertical load identification and calculation method of the present invention;

[0050] Figure 4 This is a schematic diagram of the physical model of tire force analysis in one embodiment of the tire steady-state vertical load identification and calculation method of the present invention;

[0051] Figure 5 This is a schematic diagram of the vehicle height sensor installation in one embodiment of the tire steady-state vertical load identification and calculation method of the present invention;

[0052] Figure 6 This is a schematic diagram of the lever ratio curve of the suspension component relative to the wheel center in one embodiment of the tire steady-state vertical load identification and calculation method of the present invention;

[0053] Figure 7 This is a schematic diagram of the wheel-end displacement curve of the relative unloaded state wheel ground load change in one embodiment of the tire steady-state vertical load identification and calculation method of the present invention.

[0054] Figure 8 This is a flowchart illustrating the third embodiment of the tire steady-state vertical load identification and calculation method of the present invention;

[0055] Figure 9 This is a flowchart illustrating the tire steady-state vertical load identification and calculation process in one embodiment of the tire steady-state vertical load identification and calculation method of the present invention.

[0056] Figure 10 This is a schematic diagram of the system configuration for calculating the steady-state vertical load of a vehicle tire, according to an embodiment of the tire steady-state vertical load identification and calculation method of the present invention.

[0057] Figure 11 This is a structural block diagram of the first embodiment of the tire steady-state vertical load identification and calculation device of the present invention.

[0058] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0059] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0060] Reference Figure 1 , Figure 1 This is a schematic diagram of the tire steady-state vertical load identification and calculation device structure in the hardware operating environment involved in the embodiments of the present invention.

[0061] like Figure 1As shown, the tire steady-state vertical load identification and calculation device may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen or an input unit such as a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wireless-Fidelity (Wi-Fi) interface). The memory 1005 may be a high-speed random access memory (RAM) or a stable non-volatile memory (NVM), such as a disk storage device. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0062] Those skilled in the art will understand that Figure 1 The structure shown does not constitute a limitation on the tire steady-state vertical load identification calculation device, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0063] like Figure 1 As shown, the memory 1005, which serves as a storage medium, may include an operating system, a network communication module, a user interface module, and a tire steady-state vertical load identification and calculation program.

[0064] exist Figure 1 In the tire steady-state vertical load identification and calculation device shown, the network interface 1004 is mainly used for data communication with the network server; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and memory 1005 in the tire steady-state vertical load identification and calculation device of the present invention can be set in the tire steady-state vertical load identification and calculation device. The tire steady-state vertical load identification and calculation device calls the tire steady-state vertical load identification and calculation program stored in the memory 1005 through the processor 1001 and executes the tire steady-state vertical load identification and calculation method provided in the embodiment of the present invention.

[0065] This invention provides a method for identifying and calculating the steady-state vertical load of a tire, referring to... Figure 2 , Figure 2 This is a flowchart illustrating the first embodiment of the tire steady-state vertical load identification and calculation method of the present invention.

[0066] In this embodiment, the tire steady-state vertical load identification and calculation method includes the following steps:

[0067] Step S10: Obtain the vehicle signals and vehicle parameters of the target vehicle during operation.

[0068] In this embodiment, the executing entity can be a tire vertical load identification and calculation device. This device has functions such as data processing, data communication, and program execution. The tire vertical load identification and calculation device can be a terminal device such as a computer. Of course, other devices with similar functions can also be used, and this embodiment does not limit this. For ease of explanation, this embodiment uses a tire vertical load identification and calculation device as an example.

[0069] It should be noted that with the development of vehicle electrification and intelligence, the determination of vehicle motion states places higher demands on the real-time monitoring of tire force states. For example, the development of electric vehicles allows for greater freedom in the distribution of driving force between the front and rear axles, and even the power distribution between individual vehicles. The magnitude of the tire vertical load directly determines the limit of road surface adhesion, which in turn directly determines the output limit of wheel driving force. Real-time and intelligent distribution of driving force requires real-time detection and calculation of the steady-state vertical load of the tires. The wheel vertical load is crucial data for vehicle stability control, vehicle parameters, and state identification. Currently, measuring vertical load requires installing numerous expensive sensors on the vehicle tires, involves a large amount of data during measurement, is computationally complex, and has low real-time performance.

[0070] In this embodiment, to solve the above-mentioned technical problems, the vertical load is calculated using the vehicle's own parameters. The entire process involves no complex calculations, has good real-time performance, and does not require the addition of extra sensors and wireless transmission equipment to the vehicle body. It can be achieved using existing vehicle-mounted signals and sensors, thus reducing the measurement cost of steady-state vertical load. Specifically, it can be implemented as follows.

[0071] In this specific implementation, the vertical load identified and calculated in this embodiment is the vertical load of the vehicle during driving. The target vehicle is the vehicle for which vertical load identification and calculation are required. The vehicle parameters of the target vehicle include the sprung mass and unsprung mass of the suspension (or the wheel weight at each wheel contact point), the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel center (or contact point), the total stiffness of each suspension link bushing at the wheel end, and the dynamic displacement of the wheel relative to the target vehicle body. These parameters can be directly obtained from the database. The dynamic displacement of the wheel relative to the target vehicle body can be obtained by a height sensor arranged between the vehicle body and the unsprung components.

[0072] Step S20: Monitor and identify the operating conditions of the target vehicle at various times.

[0073] In this specific implementation, the dynamic displacement of the wheel relative to the target vehicle body and the lever ratio of the shock absorber relative to the wheel center in the vehicle signal can be used to calculate the dynamic stroke of the shock absorber when it is in motion; the relative speed of the shock absorber when it is in motion can be obtained by differentiating the dynamic stroke of the shock absorber; and the road conditions of the target vehicle during its driving process can be identified by looking up a preset "road condition-shock absorber dynamic stroke-shock absorber operating speed-vehicle speed" MAP based on the dynamic stroke of the shock absorber and the relative speed of the shock absorber. The method used in this embodiment is based on the dynamic stroke D of the shock absorber. d Vibration damper operating speed V d Vehicle speed V veh Traffic conditions are identified by combining the Map of Road Conditions (MAP) database, which is used by traffic experts.

[0074] The road condition recognition expression is as follows:

[0075] R = R con_i if|D d |∈[D d_i D d_i+1 ]and|V d |∈[V d_i V d_i+1 and V veh ∈[V veh_i V veh_i+1 ]

[0076] In the above formula, i∈[1,n].

[0077] The following is an example of a traffic condition index:

[0078] R con_1 = Straight asphalt road

[0079] R con_2 = Grooved cement road

[0080] R con_3 = Grooved cement road ...

[0082] R con_n =Scene Feature Path ...

[0084] Step S30: Determine whether the operating condition meets the preset conditions based on the vehicle signal.

[0085] It is easy to understand that vehicle operating conditions are complex and variable, and vehicles frequently experience external transient impacts during driving, such as when passing speed bumps, potholes, or road seams. These external transient impacts are short-lived, typically with a response time in the millisecond range, ranging from tens to hundreds of milliseconds. However, steady-state dynamic control of the vehicle, such as the distribution of driving and braking forces, does not need to consider these millisecond-level transient responses. That is, the influence of random external road surface excitations or transient impacts on transient vertical loads can be disregarded. Therefore, this embodiment focuses on the steady-state vertical load of the target vehicle, identifying and calculating the vertical load of the target vehicle under steady-state operating conditions. By monitoring the operating conditions of the target vehicle at various times, it is determined whether the target vehicle is in a steady-state condition. Whether it is in a steady-state condition can be determined by using preset conditions to identify and exclude transient responses. When the preset conditions are met, the tire vertical load corresponding to the vehicle's operating condition can be considered to be in a relatively stable state, i.e., the steady-state vertical load. The preset conditions can be set based on vehicle signals and vehicle parameters.

[0086] In practice, the vehicle signals include, but are not limited to, spring height, vehicle speed, accelerator pedal opening, brake pedal opening, brake pressure, longitudinal acceleration, lateral acceleration, and steering wheel angle.

[0087] The step of determining whether the operating condition meets preset conditions based on the vehicle signal, i.e., identifying whether the target vehicle is in a steady-state condition, can optionally be determined using the following three preset conditions:

[0088] The first condition is to obtain the actual vehicle speed, and based on the actual vehicle speed and the road conditions during the target vehicle's driving process, retrieve the preset "Shock absorber dynamic travel threshold - road conditions - vehicle speed" MAP and "Shock absorber relative motion speed threshold - road conditions - vehicle speed" MAP, and determine the shock absorber dynamic travel threshold and shock absorber operating speed threshold.

[0089] When the dynamic stroke of the damper is less than the dynamic stroke threshold and the actuation speed of the damper is less than the actuation speed threshold, it is determined that the transient impact of the unsprung mass is small, and the dynamic load of the unsprung mass under the operating condition meets the preset steady-state operating condition conditions.

[0090] The second condition is that when the rate of change of the brake pedal opening or the rate of change of the brake master cylinder pressure is less than a preset threshold for the rate of change of the brake pedal opening, or when the rate of change of the accelerator pedal opening or the rate of change of the accelerator pedal voltage signal is less than a preset threshold for the rate of change of the accelerator pedal opening, or when the rate of change of the longitudinal acceleration is less than a preset threshold for the rate of change of the longitudinal acceleration, the longitudinal motion characteristics of the vehicle, such as the longitudinal acceleration / deceleration motion or pitch motion, in the operating condition are determined to meet the preset conditions.

[0091] The third condition involves differentiating the steering wheel angle and lateral acceleration based on the vehicle signal, respectively, to determine the rate of change of the steering wheel angular velocity and lateral acceleration. The steering wheel angular velocity threshold is obtained by looking up a preset "steering wheel angular velocity threshold - vehicle speed - steering wheel angle" data table based on the steering wheel angular velocity, or by looking up a preset "lateral acceleration rate of change threshold - vehicle speed - lateral acceleration" data table based on the rate of change of lateral acceleration. When the steering wheel angular velocity is less than the angular velocity threshold, or the rate of change of lateral acceleration is less than the lateral acceleration rate of change threshold, it indicates that the vehicle's current yaw or tilt motion, or other lateral motion state, is in a relatively stable state, or that the lateral motion state at the next moment will be in a relatively stable state. At this time, the operating condition meets the preset conditions.

[0092] Step S40: When the operating conditions meet the preset conditions, calculate the steady-state vertical load of the target vehicle tires at the corresponding moment in real time based on the vehicle signals and vehicle parameters.

[0093] It should be noted that this embodiment is aimed at the identification and calculation of steady-state vertical load under steady-state operating conditions. If the operating conditions at a certain moment are detected to meet the preset conditions, the steady-state vertical load corresponding to the target vehicle at that moment is calculated based on the vehicle parameters.

[0094] Furthermore, when the operating conditions do not meet the preset conditions, it indicates that the target vehicle is experiencing a transient impact during its operation. The vertical load at this time is essentially a step-transient response load or a transient impact load. In this case, this embodiment does not calculate the transient vertical load at this moment. Instead, it uses the steady-state vertical load from the previous moment as the vertical load at this moment. For example, assuming the target vehicle experiences a transient impact at time t, the steady-state vertical load corresponding to the previous moment t-1 is F. z (t-1), then let F z (t)=F z (t-1), thus obtaining the steady-state vertical load F at time t. z (t).

[0095] This embodiment acquires vehicle signals and vehicle parameters of the target vehicle during its operation; monitors and identifies the operating conditions of the target vehicle; determines whether the operating conditions of the target vehicle meet preset conditions based on the vehicle signals; and calculates the steady-state vertical load of the target vehicle at the corresponding time based on the vehicle parameters and vehicle signals when the operating conditions meet the preset conditions. The entire process involves no complex calculations, has good real-time performance, and requires no additional sensors or wireless transmission equipment; it can be implemented using existing vehicle signals and sensors, thus reducing the detection cost of tire steady-state vertical load.

[0096] refer to Figure 3 , Figure 3 This is a flowchart illustrating a second embodiment of the tire steady-state vertical load identification and calculation method of the present invention.

[0097] Based on the first embodiment described above, in the tire vertical load identification method of this embodiment, step S40 specifically includes:

[0098] Step S401: Extract the dynamic displacement of the wheels relative to the target vehicle body from the vehicle signal.

[0099] It should be noted that the vehicle parameters in this embodiment are the wheel weight of the target vehicle in an unloaded and ready state, the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushing transferred to the wheel end, the characteristic data of the damper damping force - the damper relative motion speed, the leverage ratio of the damper relative to the wheel, the unsprung mass of each suspension of the vehicle, and the unsprung mass of each suspension of the vehicle.

[0100] In a specific implementation, the wheel weight in this embodiment can be the sum of the sprung mass and the unsprung mass of the suspension, and the spring assembly can be an upper spring pad, a lower spring pad, and a spring, etc.

[0101] Step S402: Calculate the steady-state vertical load of the tires of the target vehicle in real time based on the wheel weight, stiffness of each elastic component, leverage ratio of each elastic component relative to the wheel, total stiffness of the suspension link bushing transferred to the wheel end, characteristic data of damper damping force - damper relative motion speed, leverage ratio of the damper relative to the wheel, unsprung mass of each suspension of the vehicle, and dynamic displacement of the wheel relative to the target vehicle body.

[0102] In practice, after obtaining the wheel weight, stiffness of each elastic component, leverage ratio of each elastic component relative to the wheel, total stiffness of the suspension link bushing transferred to the wheel end, characteristic data of damper damping force - damper relative motion speed (i.e., damper FV characteristic MAP), lever ratio of the damper relative to the wheel, unsprung mass of each suspension of the vehicle, and dynamic displacement of the wheel relative to the target vehicle body, the steady-state vertical load of the target vehicle can be calculated based on the above parameters and the calculation formula of steady-state vertical load.

[0103] It should be noted that the formula for calculating the steady-state vertical load of a tire can be derived from the formula for calculating the transient vertical load. Figure 4 For example, let's first explain the calculation formula for the transient vertical load of the tire in this embodiment, as follows:

[0104] F t =G Mb +Gmt +ΔF Ks +ΔF Cd +ΔF t

[0105] In the above formula, G Mb =M b g represents the sprung mass M b The force of gravity acting on the body, g is the acceleration due to gravity, M b G represents the sprung mass of a single suspension unit in an unloaded, ready-to-go state; mt =m t g represents the gravitational force acting on the unsprung mass of a single suspension element. Where m... t ΔF represents the unsprung mass of a single suspension unit in an unloaded, ready-to-go state. Cd This represents the equivalent dynamic load of the damper's damping force at the wheel end; ΔF Ks ΔF represents the change in equivalent load at the wheel ends of all suspension elastic components relative to the unloaded, ready-to-go state; t The dynamic load represents the unsprung mass.

[0106] Before explaining the calculation formula for the steady-state vertical load of a tire, the derivation of the calculation formula for the transient vertical load will be explained first.

[0107] Still with Figure 4 Theoretical derivation of the transient vertical load on the tires is performed using the 1 / 4 scale vehicle model shown. The equations of motion for the sprung mass and unsprung mass are as follows:

[0108]

[0109]

[0110] From (2), we can obtain

[0111]

[0112] From (1) and (2), we can obtain

[0113]

[0114] Substituting (3) into (4) yields the following equation (5).

[0115]

[0116] At the same time, such as Figure 4 As shown, considering the suspension of 1 / 4 of the vehicle as a whole for analysis, the following dynamic equations can be established:

[0117]

[0118] Substituting (5) into (6) yields equation (7).

[0119]

[0120] Therefore, the theoretical calculation expression for the transient vertical load of the tire can be obtained as follows:

[0121]

[0122] The physical quantities in equations (1) to (8) are explained as follows:

[0123] M b For the suspension sprung mass (1 / 4 of the vehicle body mass), K s For suspension stiffness, C d K is the suspension damping coefficient. t C represents the radial stiffness of the tire. t The tire damping coefficient, m t Z represents the unsprung mass (non-sprung mass) of the suspension. b Z represents the displacement of the sprung mass. t For wheel displacement, Z r For road surface unevenness input, F d For the external disturbance input, F t This refers to the transient vertical load on the tire.

[0124] As can be seen from equation (8) above, the vertical load of the wheel can be composed of the sprung mass gravity, the unsprung mass gravity, the equivalent elastic force of the suspension system at the wheel end, the equivalent damping force of the suspension system, and the dynamic load of the unsprung mass. The contact state between the tire and the ground is complex, but as can be seen from the above equation, the transient vertical load of the tire, which is difficult to detect and changes at an extremely fast rate, can theoretically be converted into a physical quantity that is easy to detect and has mature and reliable acquisition methods. Through conversion and calculation, it is theoretically possible to perform real-time detection and accurate calculation.

[0125] Based on the above theoretical derivation, and further considering the engineering implementation method, the calculation is performed with the unloaded state as the reference state, and the following formula (9) is used to calculate the transient vertical load of the tire based on the theory of the above formula (8):

[0126] F t_ins =G Mb +G mt +ΔF Ks +ΔF Cd +ΔF t (9)

[0127] Equation (9) above is the formula for calculating the transient vertical load of the tire.

[0128] As described in step S30 of the first embodiment, steady-state vehicle dynamics control does not require the detection and identification of transient impact responses at the millisecond level, such as the transient impact response of a vehicle passing over a speed bump, pothole, or road seam. The response of the unsprung mass to external road surface excitation can be regarded as a random excitation response with a mean of zero. This component can be considered to have no effect or a very small effect in the steady-state vertical load of the tire. By identifying and excluding the transient response and random excitations of different road surfaces through preset conditions, the steady-state vertical load of the tire can be obtained, that is, the larger unsprung mass dynamic load ΔF in equation (9) can be identified and excluded. t The steady-state vertical load of the wheel is obtained. The formula for calculating the steady-state vertical load of the tire is as follows:

[0129] F t =G Mb +G mt +ΔF Ks +ΔF Cd (10)

[0130] In equation (10), compared with equation (8), G Mb =M b g represents the sprung mass M b The force of gravity acting on the body, g is the acceleration due to gravity, M b G represents the sprung mass of a single suspension unit in an unloaded, ready-to-go state; mt =m t g represents the gravitational force acting on the unsprung mass of a single suspension element. Where m... t This represents the unsprung mass of a single suspension unit in an unloaded, ready-to-go state. In practice, the wheel weight at the contact point of each wheel of the target vehicle in an unloaded, ready-to-go state can be directly measured, and the wheel weight can be used to replace G in equation (9). Mb +G mt .

[0131] In equation (10), ΔF Cd This represents the equivalent dynamic load of the damping force of the shock absorber at the wheel end. Compared with equation (8), In practical implementation, the equivalent dynamic load of the damping force of the shock absorber at the wheel end can be calculated from the damping force of the shock absorber minus the relative motion velocity data of the shock absorber and the lever ratio of the shock absorber. Where, ΔF Cd0 ρ represents the real-time damping force of the vibration damper. d This indicates the lever ratio of the shock absorber relative to the wheel. The real-time damping force of the shock absorber can be obtained from the damping force - shock absorber actuation relative velocity (FV) database by looking up the relative motion velocity of the shock absorber during operation. The relative motion velocity of the shock absorber during operation can be obtained in the following way: Figure 5As shown, S is the vehicle height sensor. The signal collected by the height sensor can be used to obtain the dynamic displacement (Z) of the wheels relative to the target vehicle body. b -Z t Then, by differentiating the dynamic displacement of the target vehicle body, the relative velocity of the target vehicle body can be obtained, that is, the velocity relative to Z. b -Z t Differential calculations are performed to obtain Then, this value is compared with the lever ratio ρ of the shock absorber relative to the wheel. d Multiplying these values ​​yields the relative velocity of the shock absorber when it is in operation. Figure 5 In the middle, F t This represents the steady-state vertical load on the tire calculated in this embodiment.

[0132] In equation (9), ΔF Ks This represents the change in equivalent load at the wheel ends of all elastic components of the suspension relative to the unloaded, ready-to-go state. Compared to equation (8), ΔF Ks =K s ΔZ s =K s (Z b -Z t ), where K s Z represents the equivalent total stiffness of all elastic components of the suspension at the wheel end. b -Z t This indicates the dynamic displacement of the wheels relative to the target vehicle body. Further, Among them, K si ρ represents the stiffness of each elastic component. si This indicates the leverage ratio of each elastic component relative to the wheel, for example, such as... Figure 5 As shown, the lever ratio of the spring relative to the wheel end is L1 / L2, where L2 is the wheel end travel and L1 is the spring deformation when the wheel end travels L2. For accurate calculation, the lever ratio of each elastic component relative to different wheel end travels can be calculated and output through the suspension K&C characteristic simulation model, such as... Figure 6 As shown in the diagram; K b This represents the equivalent stiffness of each bushing of the suspension at the wheel end. In practical implementation, besides using the above formula to calculate ΔF at different suspension travel positions... Ks Alternatively, suspension load-wheel end displacement curve data can be obtained through suspension K&C characteristic simulation calculations or actual measurements. The curve data is as follows: Figure 7 As shown, then the dynamic displacement (Z) of the wheels relative to the target vehicle body is used. b -Z t Directly retrieve the elastic force under the corresponding wheel end stroke.

[0133] This embodiment extracts the dynamic displacement of the wheel relative to the target vehicle body from the vehicle signal. Based on the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel, and the equivalent stiffness of the suspension bushing at the wheel end, it calculates the equivalent total stiffness of all suspension elastic components at the wheel end. Based on the equivalent total stiffness of all suspension elastic components at the wheel end and the dynamic displacement of the wheel relative to the target vehicle body, it calculates in real time the equivalent load change of all suspension elastic components at the wheel end relative to the unloaded, ready-to-go state at the corresponding moment. Suspension load-displacement curve data is obtained through suspension K&C characteristic simulation or through actual vehicle measurement. Based on the dynamic displacement of the wheel relative to the target vehicle body, it retrieves the equivalent load change of all suspension elastic components at the wheel end relative to the unloaded, ready-to-go state at the corresponding moment from the suspension load-displacement curve data. The suspension load-displacement curve data represents the dynamic displacement of the wheel relative to the target vehicle body in the unloaded, ready-to-go state. The equivalent load change of all elastic components at the wheel end is calculated; the relative motion speed of the wheel relative to the target vehicle body is obtained by differential calculation based on the dynamic displacement of the wheel relative to the target vehicle body; the relative motion speed of the shock absorber when it is activated is calculated based on the relative motion speed of the wheel relative to the target vehicle body and the lever ratio of the shock absorber relative to the wheel; the real-time damping force of the shock absorber is obtained by looking up the damping force-shock absorber activation relative speed database based on the relative motion speed of the shock absorber when it is activated; the equivalent dynamic load of the shock absorber damping force at the wheel end is calculated based on the real-time damping force of the shock absorber and the lever ratio of the shock absorber relative to the wheel; the tire steady-state vertical load of the target vehicle at the corresponding moment is calculated in real time based on the wheel weight of the target vehicle in the unloaded and ready state, the equivalent load change of all elastic components of the suspension at the wheel end relative to the unloaded and ready state, and the equivalent dynamic load of the shock absorber at the wheel end, thus improving the accuracy of the tire steady-state vertical load calculation.

[0134] refer to Figure 8 , Figure 8 This is a flowchart illustrating the third embodiment of the tire steady-state vertical load identification and calculation method of the present invention.

[0135] Based on the first or second embodiment described above, a third embodiment of the present invention is proposed for tire steady-state vertical load identification and calculation.

[0136] In the third embodiment, to identify whether the target vehicle is in a steady-state operating condition, the vehicle signal is used to determine whether the operating condition meets preset conditions. The third embodiment is described based on the first embodiment above, and expands the process of using vehicle signals to determine whether the operating condition meets preset conditions and thus whether the vehicle is in a steady-state operating condition to the entire process of tire steady-state vertical load identification and calculation, as follows: Figure 9 As shown.

[0137] In this embodiment, step S30 specifically includes:

[0138] Step S301: Calculate the dynamic stroke of the shock absorber when it is in motion based on the dynamic displacement of the wheel relative to the target vehicle body and the lever ratio of the shock absorber relative to the wheel center in the vehicle signal.

[0139] Step S302: Obtain the relative speed of the damper when it operates by differentiating the dynamic stroke of the damper.

[0140] Step S303: Based on the dynamic stroke of the shock absorber and the relative speed of the shock absorber, retrieve the preset "Road Condition-Shock Absorber Dynamic Stroke-Shock Absorber Operating Speed-Vehicle Speed" MAP to identify the road conditions of the target vehicle during its operation.

[0141] It should be noted that the road condition recognition process can refer to the above steps S10-S20, and will not be repeated in this embodiment.

[0142] Step S304: Obtain the actual vehicle speed, and based on the actual vehicle speed and the road conditions during the target vehicle's driving process, retrieve the preset "Shock absorber dynamic travel threshold - road conditions - vehicle speed" MAP and "Shock absorber relative motion speed threshold - road conditions - vehicle speed" MAP to determine the shock absorber dynamic travel threshold and shock absorber operating speed threshold.

[0143] Step S305: When the dynamic stroke of the shock absorber is less than the dynamic stroke threshold and the actuation speed of the shock absorber is less than the actuation speed threshold, it is determined that the operating condition meets the preset conditions.

[0144] In practice, there are three ways to determine whether the operating conditions meet the preset conditions.

[0145] The first method is to identify whether the dynamic load of the unsprung mass under the operating conditions meets the preset steady-state operating conditions, so as to determine whether the unsprung mass is subjected to transient impact.

[0146] This method primarily determines whether the unsprung mass is subjected to transient impacts and identifies and eliminates transient impacts on the unsprung mass. In specific implementation, the actual vehicle speed V can be obtained, and based on the actual vehicle speed V... veh Based on the road conditions R of the target vehicle during its journey, the preset "Shock absorber dynamic travel threshold - road conditions - vehicle speed" MAP and "Shock absorber relative motion speed threshold - road conditions - vehicle speed" MAP are retrieved to determine the shock absorber dynamic travel threshold D. d_val and the shock absorber operating speed threshold V d_val The expression for the above judgment logic is as follows.

[0147] D d_val =Dd_val_k if R = R con_i and V veh ∈[V veh_i V veh_i+1 ]

[0148] V d_val =V d_val_k if R = R con_i and V veh ∈[V veh_i V veh_i+1 ]

[0149] In the above formula, i,k∈[1,n].

[0150] The shock absorber's dynamic stroke D d Less than the dynamic stroke threshold D d_val And the vibration damper's operating speed V d Less than the actuation speed threshold V d_val When the transient impact on the unsprung mass is relatively small, it is determined that the dynamic load on the unsprung mass under the operating condition meets the preset steady-state operating conditions. The expression for the above judgment logic is as follows.

[0151] Con ver =Y, if|D d |≤D d_val and|V d |≤V d_val

[0152] In the above formula, Y represents the preset steady-state operating conditions.

[0153] The second method is to determine whether the longitudinal motion characteristics of the vehicle under the operating conditions meet the preset conditions.

[0154] Specifically, in the brake pedal opening change rate B c (or the rate of change of brake master cylinder pressure) is less than the preset threshold B for the rate of change of brake pedal opening. c_val Or, the rate of change of the accelerator pedal opening A c Or the rate of change of the accelerator pedal voltage signal is less than the preset threshold A for the rate of change of accelerator pedal opening. c_val , or in the longitudinal acceleration change rate A c_lon Less than the preset longitudinal acceleration change rate threshold A c_lon_val When the vehicle's current longitudinal acceleration, deceleration, and pitch motion are stable, or when the vehicle's longitudinal motion is expected to stabilize, the operating condition meets the preset operating condition. The expression for the above judgment logic is as follows.

[0155] Con lon =Y, if|Bc |≤B c_val or|A c |≤A c_val or|A c_lon |≤A c_lon_val

[0156] In the above formula, Y represents the preset steady-state operating conditions.

[0157] The third method is to determine whether the lateral motion characteristics of the vehicle under the operating conditions meet the preset conditions.

[0158] Specifically, based on the vehicle signal steering wheel angle A s Lateral acceleration A lat Determine the steering wheel angular velocity W by taking the differential. s and the rate of change of lateral acceleration A c_lat According to the steering wheel angular velocity W s Retrieve the preset "steering wheel angular velocity threshold - vehicle speed - steering wheel angle" data table to obtain the steering wheel angular velocity threshold W. s_val Or based on the lateral acceleration rate of change A c_lat Retrieve the steering wheel angular velocity threshold W from the preset "lateral acceleration change rate threshold - vehicle speed - lateral acceleration" data table. s_val At the steering wheel angular velocity W s Less than the angular velocity threshold W s_val , or the lateral acceleration change rate A c_lat Less than the lateral acceleration rate of change threshold A lon_val When the vehicle's yaw and roll movements under its current operating conditions or its lateral movements at the next moment meet preset conditions, the expression for the above judgment logic is as follows.

[0159] Con lat =Y, if|B c |≤B c_val or|A c |≤A c_val or|A lon |≤A lon_val

[0160] In the above formula, Y represents the preset steady-state operating conditions.

[0161] When all the above conditions are met, it can be determined that the vehicle's current operating condition is in a steady state. The expression for the judgment logic is as follows. The next step is to calculate the steady-state tire vertical load.

[0162] Con = Y, if Con ver =Y and Con lon =Y and Conlat =Y

[0163] In the above formula, Y represents the preset steady-state operating conditions.

[0164] It should be noted that the preset thresholds for brake pedal opening rate of change, accelerator pedal opening rate of change, longitudinal acceleration rate of change, lateral acceleration rate of change, and angular velocity in the above-mentioned judgment conditions can be set according to actual measurement needs, and this embodiment does not impose any restrictions on this.

[0165] Furthermore, the system configuration and principle of the vehicle tire steady-state vertical load calculation in this embodiment of the invention are as follows: Figure 10 As shown. (Refer to...) Figure 10 , Figure 10 FL, FR, RL, and RR are the four suspensions corresponding to the vehicle. Each suspension is equipped with a height sensor. The vehicle controller communicates through the CAN network and outputs the vehicle's ground steady-state vertical load. The controller includes an MCU microcontroller module, a power supply module, a communication module, and a constant current module.

[0166] This embodiment identifies the transient and stable operating conditions of the target vehicle during driving by using multiple judgment conditions, and then filters out the transient impact response, thereby improving the accuracy of steady-state vertical load measurement.

[0167] Furthermore, this embodiment of the invention also proposes a storage medium storing a tire steady-state vertical load identification and calculation program. When the tire steady-state vertical load identification and calculation program is executed by a processor, it implements the steps of the tire steady-state vertical load identification and calculation method described above.

[0168] Since this storage medium adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0169] Reference Figure 11 , Figure 11 This is a structural block diagram of the first embodiment of the tire steady-state vertical load identification and calculation device of the present invention.

[0170] like Figure 11 As shown, the tire steady-state vertical load identification and calculation device proposed in this embodiment of the invention includes:

[0171] The reading module 10 is used to acquire vehicle signals and vehicle parameters of the target vehicle during operation.

[0172] The monitoring module 20 is used to monitor and identify the operating conditions of the target vehicle at various times.

[0173] The judgment module 30 is used to determine whether the operating condition meets the preset conditions based on the vehicle signal.

[0174] The calculation module 40 is used to calculate the steady-state vertical load of the target vehicle tires in real time based on the vehicle signals and vehicle parameters when the operating conditions meet the preset conditions.

[0175] This embodiment acquires vehicle signals and vehicle parameters of the target vehicle during its operation; monitors the operating conditions of the target vehicle at various times; determines whether the operating conditions meet preset conditions based on the vehicle signals; and calculates the steady-state vertical load of the target vehicle at the corresponding time based on the vehicle parameters when the operating conditions meet the preset conditions. The entire process involves no complex calculations, has good real-time performance, and requires no additional sensors or wireless transmission equipment, utilizing existing vehicle signals and sensors, thus reducing the measurement cost of steady-state vertical load.

[0176] In one embodiment, the vehicle parameters include the wheel weight of the target vehicle in an unloaded and prepared state, the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushings transferred to the wheel end, the characteristic data of the damper damping force-dampening relative motion speed, the leverage ratio of the damper relative to the wheel, the unsprung mass of each suspension of the vehicle, and the unsprung mass of each suspension of the vehicle.

[0177] The calculation module 40 is further configured to extract the dynamic displacement of the wheel relative to the target vehicle body from the vehicle signal; and to calculate the steady-state vertical load of the target vehicle tire in real time based on the wheel weight of the target vehicle in an unloaded preparation state, the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushing transferred to the wheel end, the characteristic data of the damper damping force-dampening relative motion speed, the leverage ratio of the damper relative to the wheel, the unsprung mass of each suspension of the vehicle, and the dynamic displacement of the wheel relative to the target vehicle body.

[0178] In one embodiment, the calculation module 40 is further configured to calculate the equivalent total stiffness of all elastic components of the corresponding suspension at the wheel end based on the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel, and the equivalent stiffness of the suspension bushing at the wheel end.

[0179] The equivalent total stiffness of all the elastic components of the suspension at the wheel end and the dynamic displacement of the wheel relative to the target vehicle body are used to calculate in real time the equivalent load change of all the elastic components of the suspension at the wheel end relative to the unloaded and ready state at the corresponding moment.

[0180] Suspension load-displacement curve data is obtained through suspension K&C characteristic simulation calculations or actual vehicle measurements. Based on the dynamic displacement of the wheel relative to the target vehicle body, the equivalent load change at the wheel end of all suspension elastic components relative to the unloaded, ready-to-ride state is retrieved from the suspension load-displacement curve data at the corresponding moment. The suspension load-displacement curve data represents the equivalent load change at the wheel end of all elastic components corresponding to the dynamic displacement of the wheel relative to the target vehicle body in the unloaded, ready-to-ride state. The relative velocity of the wheel relative to the target vehicle body is obtained by differential calculation based on the dynamic displacement of the wheel relative to the target vehicle body. The relative motion speed of the vehicle body and the lever ratio of the shock absorber to the wheel are used to calculate the relative motion speed of the shock absorber when it is activated. Based on the relative motion speed of the shock absorber when it is activated, the shock absorber damping force-shock absorber activation relative speed database is retrieved to obtain the real-time damping force of the shock absorber. Based on the real-time damping force of the shock absorber and the lever ratio of the shock absorber to the wheel, the equivalent dynamic load of the shock absorber damping force at the wheel end is calculated. Based on the wheel weight of the target vehicle in an unloaded and ready state, the change in equivalent load of all elastic components of the suspension at the wheel end relative to the unloaded and ready state, and the equivalent dynamic load of the shock absorber at the wheel end, the steady-state vertical load of the tires of the target vehicle at the corresponding moment is calculated in real time.

[0181] In one embodiment, the judgment module 30 is further configured to: calculate the dynamic stroke of the shock absorber when it operates based on the dynamic displacement of the wheel relative to the target vehicle body and the lever ratio of the shock absorber relative to the wheel center in the vehicle signal; obtain the relative speed of the shock absorber when it operates by differentiating the dynamic stroke of the shock absorber; identify the road conditions of the target vehicle during driving by looking up a preset "road condition-shock absorber dynamic stroke-shock absorber operating speed-vehicle speed" MAP based on the dynamic stroke of the shock absorber and the relative speed of the shock absorber; obtain the actual speed of the vehicle, and determine the shock absorber dynamic stroke threshold and the shock absorber operating speed threshold by looking up a preset "shock absorber dynamic stroke threshold-road condition-vehicle speed" MAP and "shock absorber relative motion speed threshold-road condition-vehicle speed" MAP based on the actual speed of the vehicle and the road conditions of the target vehicle during driving; and determine that the operating condition meets the preset conditions when the dynamic stroke of the shock absorber is less than the dynamic stroke threshold and the operating speed of the shock absorber is less than the operating speed threshold.

[0182] In one embodiment, the judgment module 30 is further configured to perform differential calculations on the brake pedal opening, accelerator pedal opening, and longitudinal acceleration in the vehicle signal to obtain the brake pedal opening change rate, accelerator pedal opening change rate, and longitudinal acceleration change rate; when the brake pedal opening change rate is less than a preset brake pedal opening change rate threshold, or the accelerator pedal opening change rate is less than a preset accelerator pedal opening change rate threshold, or the longitudinal acceleration change rate is less than a longitudinal acceleration change rate threshold, the operating condition is determined to meet the preset conditions.

[0183] In one embodiment, the judgment module 30 is further configured to perform differential calculations on the brake master cylinder pressure and accelerator pedal voltage in the vehicle signal to obtain the brake master cylinder pressure change rate and the accelerator pedal voltage change rate; when the brake master cylinder pressure change rate is less than a preset brake master cylinder pressure change rate threshold, or the accelerator pedal voltage change rate is less than a preset accelerator pedal voltage change rate threshold, the operating condition is determined to meet the preset conditions.

[0184] In one embodiment, the judgment module 30 is further configured to perform differential calculations on the steering wheel angle and lateral acceleration in the vehicle signal to obtain the rate of change of steering wheel angular velocity and lateral acceleration; obtain the steering wheel angular velocity threshold by looking up a preset "steering wheel angular velocity threshold - vehicle speed" data table based on the steering wheel angular velocity; and determine that the operating condition meets the preset conditions when the steering wheel angular velocity is less than the angular velocity threshold or the rate of change of lateral acceleration is less than the lateral acceleration rate of change threshold.

[0185] It should be understood that the above are merely illustrative examples and do not constitute any limitation on the technical solutions of the present invention. In specific applications, those skilled in the art can make settings as needed, and the present invention does not impose any restrictions on this.

[0186] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of this invention. In practical applications, those skilled in the art can select some or all of the workflow to achieve the purpose of this embodiment according to actual needs, and no restrictions are imposed here.

[0187] In addition, for technical details not described in detail in this embodiment, please refer to the tire steady-state vertical load identification and calculation method provided in any embodiment of the present invention, which will not be repeated here.

[0188] Furthermore, 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 system 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 system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0189] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0190] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, 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 read-only memory (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 the present invention.

[0191] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A method for identifying and calculating the steady-state vertical load of a tire, characterized in that, The method for identifying and calculating the steady-state vertical load of the tire includes: The system acquires vehicle signals and vehicle parameters of the target vehicle during operation. The vehicle parameters include wheel weight when the target vehicle is in an unloaded and ready state, stiffness of each elastic component, leverage ratio of each elastic component relative to the wheel, total stiffness of suspension link bushings transferred to the wheel end, characteristic data of damper damping force-dampening relative speed, leverage ratio of damper relative to wheel, unsprung mass of each suspension of the vehicle, and unsprung mass of each suspension of the vehicle. The vehicle signals include sprung height, vehicle speed, accelerator pedal opening, brake pedal opening, brake pressure, longitudinal acceleration, lateral acceleration, and steering wheel angle. Monitor and identify the operating conditions of the target vehicle at various times; Determine whether the operating condition meets the preset conditions based on the vehicle signal; When the operating conditions meet the preset conditions, the steady-state vertical load of the target vehicle tires at the corresponding moment is calculated in real time based on the vehicle signals and vehicle parameters.

2. The tire steady-state vertical load identification and calculation method as described in claim 1, characterized in that, The step of calculating the steady-state vertical load of the target vehicle tires at the corresponding moment based on the vehicle signals and vehicle parameters includes: Extract the dynamic displacement of the wheels relative to the target vehicle body from the vehicle signal; Based on the target vehicle's wheel weight in an unloaded and ready state, the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushing transferred to the wheel end, the characteristic data of the damper damping force - the damper's relative motion speed, the leverage ratio of the damper relative to the wheel, the unsprung mass of each suspension of the vehicle, and the dynamic displacement of the wheel relative to the target vehicle body, the steady-state vertical load of the target vehicle's tires at the corresponding moment is calculated in real time.

3. The tire steady-state vertical load identification and calculation method as described in claim 2, characterized in that, The method of calculating the steady-state vertical load of the target vehicle's tires in real time based on the target vehicle's wheel weight in an unloaded and prepared state, the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushings transferred to the wheel end, the characteristic data of the damper damping force-dampening force relative to the damper's relative motion speed, the leverage ratio of the damper relative to the wheel, the unsprung mass of each suspension component of the vehicle, and the dynamic displacement of the wheel relative to the target vehicle body includes: Based on the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel, and the equivalent stiffness of the suspension bushing at the wheel end, calculate the equivalent total stiffness of all elastic components of the corresponding suspension at the wheel end. The equivalent total stiffness of all the elastic components of the suspension at the wheel end and the dynamic displacement of the wheel relative to the target vehicle body are used to calculate the equivalent load change of all the elastic components of the suspension at the wheel end at the corresponding moment relative to the unloaded and ready state. The suspension load-displacement curve data is obtained through suspension K&C characteristic simulation calculation or actual measurement of the vehicle. Based on the dynamic displacement of the wheel relative to the target vehicle body, the equivalent load change at the wheel end of all elastic components of the suspension at the corresponding moment is retrieved from the suspension load-displacement curve data relative to the unloaded and ready state. The suspension load-displacement curve data represents the equivalent load change at the wheel end of all elastic components corresponding to the dynamic displacement of the wheel relative to the target vehicle body in the unloaded and ready state. The relative velocity of the wheel relative to the target vehicle body is obtained by differential calculation based on the dynamic displacement of the wheel relative to the target vehicle body; The relative motion speed of the shock absorber when it is activated is calculated based on the relative motion speed of the wheel relative to the target vehicle body and the lever ratio of the shock absorber relative to the wheel. Based on the relative motion speed of the damper during operation, the damper damping force and damper operation relative velocity database are retrieved to obtain the real-time damping force of the damper. The equivalent dynamic load of the damping force of the shock absorber at the wheel end is calculated based on the real-time damping force of the shock absorber and the lever ratio of the shock absorber relative to the wheel. The steady-state vertical load of the target vehicle's tires at the corresponding moment is calculated in real time based on the wheel weight of the target vehicle in an unloaded and ready state, the equivalent load change of all elastic components of the suspension at the wheel end relative to the unloaded and ready state, and the equivalent dynamic load of the shock absorber at the wheel end.

4. The tire steady-state vertical load identification and calculation method according to any one of claims 1 to 3, characterized in that, Determining whether the operating condition meets preset conditions based on the vehicle signal includes: The dynamic stroke of the shock absorber when it is in motion is calculated based on the dynamic displacement of the wheel relative to the target vehicle body and the lever ratio of the shock absorber relative to the wheel center in the vehicle signal. The relative velocity of the damper during operation can be obtained by differentiating its dynamic stroke. Based on the dynamic stroke of the shock absorber and the relative speed of the shock absorber during operation, a preset "Road Condition-Shock Absorber Dynamic Stroke-Shock Absorber Operation Speed-Vehicle Speed" MAP is retrieved to identify the road conditions of the target vehicle during its operation. The actual vehicle speed is obtained, and the preset "shock absorber dynamic travel threshold - road condition - vehicle speed" MAP and "shock absorber relative motion speed threshold - road condition - vehicle speed" MAP are retrieved based on the actual vehicle speed and the road conditions during the target vehicle's driving process to determine the shock absorber dynamic travel threshold and shock absorber actuation speed threshold. When the dynamic stroke of the shock absorber is less than the dynamic stroke threshold and the operating speed of the shock absorber is less than the operating speed threshold, the operating condition is determined to meet the preset conditions.

5. The tire steady-state vertical load identification and calculation method according to any one of claims 1 to 3, characterized in that, The step of determining whether the operating condition meets the preset conditions based on the vehicle signal includes: The brake pedal opening, accelerator pedal opening, and longitudinal acceleration in the vehicle signals are calculated by differentiation to obtain the rate of change of brake pedal opening, the rate of change of accelerator pedal opening, and the rate of change of longitudinal acceleration. When the rate of change of the brake pedal opening is less than a preset threshold for the rate of change of the brake pedal opening, or the rate of change of the accelerator pedal opening is less than a preset threshold for the rate of change of the accelerator pedal opening, or the rate of change of the longitudinal acceleration is less than a threshold for the rate of change of the longitudinal acceleration, the operating condition is determined to meet the preset conditions.

6. The tire steady-state vertical load identification and calculation method according to any one of claims 1 to 3, characterized in that, The step of determining whether the operating condition meets the preset conditions based on the vehicle signal further includes: The brake master cylinder pressure and accelerator pedal voltage in the vehicle signal are respectively differentiated to obtain the brake master cylinder pressure change rate and accelerator pedal voltage change rate. When the rate of change of the brake master cylinder pressure is less than a preset threshold for the rate of change of the brake master cylinder pressure, or when the rate of change of the accelerator pedal voltage is less than a preset threshold for the rate of change of the accelerator pedal voltage, the operating condition is determined to meet the preset conditions.

7. The tire steady-state vertical load identification and calculation method according to any one of claims 1 to 3, characterized in that, The step of determining whether the operating condition meets the preset conditions based on the vehicle signal includes: The steering wheel angle and lateral acceleration in the vehicle signal are differentiated and calculated to obtain the rate of change of steering wheel angular velocity and lateral acceleration. The steering wheel angular velocity threshold is obtained by looking up the preset "steering wheel angular velocity threshold - vehicle speed" data table. When the steering wheel angular velocity is less than the angular velocity threshold, or the lateral acceleration change rate is less than the lateral acceleration change rate threshold, the operating condition is determined to meet the preset conditions.

8. A tire vertical load identification and calculation device, characterized in that, The tire vertical load identification and calculation device includes: The reading module is used to acquire vehicle signals and vehicle parameters of the target vehicle during operation. The vehicle parameters include wheel weight when the target vehicle is in an unloaded and ready state, stiffness of each elastic component, leverage ratio of each elastic component relative to the wheel, total stiffness of suspension link bushings transferred to the wheel end, characteristic data of damper damping force-dampening relative speed, leverage ratio of damper relative to wheel, unsprung mass of each suspension of the vehicle, and unsprung mass of each suspension of the vehicle. The vehicle signals include sprung height, vehicle speed, accelerator pedal opening, brake pedal opening, brake pressure, longitudinal acceleration, lateral acceleration, and steering wheel angle. The monitoring module is used to monitor and identify the operating conditions of the target vehicle at various times. The judgment module is used to determine whether the operating condition meets preset conditions based on the vehicle signal. The calculation module is used to calculate the steady-state vertical load of the target vehicle tires in real time based on the vehicle signals and vehicle parameters when the operating conditions meet the preset conditions.

9. A tire vertical load identification and calculation device, characterized in that, The tire vertical load identification and calculation device includes: a memory, a processor, and a tire steady-state vertical load identification and calculation program stored in the memory and running on the processor, wherein the tire vertical load identification and calculation program is configured to implement the tire vertical load identification and calculation method as described in any one of claims 1 to 7.

10. A storage medium, characterized in that, The storage medium stores a tire steady-state vertical load identification and calculation program, which, when executed by a processor, implements the tire vertical load identification and calculation method as described in any one of claims 1 to 7.

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