Method and device for calculating transient vertical load of vehicle tire, equipment and storage medium

Abstract

The present invention discloses a method and device, equipment and storage medium for calculating the transient vertical load of vehicle tires, belonging to the technical field of vehicles. The present invention obtains vehicle signals and vehicle parameters of a target vehicle during operation; detects and calculates whether the wheels of the target vehicle are in contact with the ground; when the wheels of the target vehicle are in contact with the ground, the transient vertical load of the tires of the target vehicle at the corresponding moment is calculated in real time according to the vehicle signals and vehicle parameters. The present invention is based on a calculation and analysis method for identifying whether the wheels are in contact with the ground and a calculation method for the transient vertical load of the tires demonstrated and deduced, converting the detection of the tire vertical load, which is difficult to detect, costly, low in accuracy, low in reliability, complex in calculation and poor in real-time performance in the prior art, into a technology that is easy to detect, high in reliability, low in cost, simple in calculation and high in real-time performance, and develops an ability for the vehicle to perceive the road surface in real time.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to a method and device for calculating the transient vertical load of a vehicle tire, equipment and a storage medium. Background Art

[0002] The force and torque between the tire and the ground directly determine the vehicle's motion state. It can be said that the stress state of the tire directly determines the vehicle's handling performance, stability, power, braking, comfort and even passability. Especially with the development of automobile electrification and intelligence, it provides a very large degree of freedom for various dynamic controls of the vehicle. At the same time, it puts forward higher requirements for the real-time detection of the vehicle's motion state, including the real-time monitoring of the ground contact state and stress state of the tire and the ground. For example, if the wheel is out of contact with the ground, it is not good for the vehicle's handling, stability, power, braking, etc.; for another example, the size of the vertical load of the vehicle tire directly determines the limit of the road adhesion, and also determines the limit of the driving force and braking force of a single wheel.

[0003] Currently, there are tire pressure monitoring system (TPMS) products, but existing vehicles do not have real-time perception and identification capabilities for their own ground contact status during driving, including whether the wheels are grounded (for example, the wheels are impacted or lose contact with the ground through a pit), and how to accurately identify and calculate the size of the vehicle tire's real-time vertical load in real time. Existing technology cannot detect or perceive this in a stable, reliable, and real-time manner.

[0004] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0005] The main purpose of the present invention is to provide a method and device, equipment and storage medium for calculating the transient vertical load of a vehicle tire, aiming to solve the technical problem that the prior art cannot stably, reliably and in real time identify whether the wheel is grounded and cannot accurately and reliably calculate the transient vertical load of the tire in real time.

[0006] The present invention detects the height change between the sprung mass and the unsprung wheel in real time through a height sensor installed between the vehicle body and the unsprung parts (parts of the wheel assembly or connecting rods, etc.), and obtains the acceleration signal of the unsprung mass through an acceleration sensor, proposes a calculation and analysis model for identifying whether the wheel is grounded or not, as well as a related judgment calculation method and process for identifying whether the wheel is grounded or not, and proposes a formula derived by theoretical demonstration to calculate and solve the transient vertical load of the target vehicle wheel in real time. The present invention provides a solution that is easy to detect, highly reliable, low cost, simple to calculate, and highly real-time, and does not require additional complex sensors and equipment, which also reduces the cost of calculation and detection.

[0007] To achieve the above object, the transient vertical load calculation method for vehicle tires of the present invention includes the following steps:

[0008] Obtain the vehicle signals during the operation of the target vehicle and the vehicle parameters of the target vehicle;

[0009] Detect and calculate whether the wheels of the target vehicle are grounded;

[0010] When the wheels of the target vehicle are grounded, calculate the transient vertical load of the target vehicle tires at the corresponding moment in real time according to the vehicle signals and vehicle parameters.

[0011] Optionally, the vehicle parameters include the wheel weight of the target vehicle in the unloaded and ready state, the stiffness of each elastic component, the lever ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushings converted to the wheel end, the characteristic data of the shock absorber damping force - shock absorber relative movement speed, the lever ratio of the shock absorber relative to the wheel, and the unsprung mass of each suspension of the vehicle;

[0012] The real-time calculation of the transient vertical load of the target vehicle tires at the corresponding moment according to the vehicle signals and vehicle parameters includes:

[0013] Obtain the dynamic displacement of the wheel relative to the vehicle body of the target vehicle and the acceleration of the unsprung mass from the vehicle signals;

[0014] Calculate the transient vertical load of the target vehicle tires at the corresponding moment according to the wheel weight of the target vehicle in the unloaded and ready state, the stiffness of each elastic component, the lever ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushings at the wheel end, the characteristic data of the shock absorber damping force - shock absorber relative movement speed, the lever ratio of the shock absorber relative to the wheel, the dynamic displacement of the wheel relative to the vehicle body of the target vehicle, the unsprung mass of each suspension of the vehicle, and the acceleration of the unsprung mass.

[0015] Optionally, the calculation of the transient vertical load of the target vehicle tires at the corresponding moment according to the wheel weight of the target vehicle in the unloaded and ready state, the stiffness of each elastic component, the lever ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushings at the wheel end, the characteristic data of the shock absorber damping force - shock absorber relative movement speed, the lever ratio of the shock absorber relative to the wheel, the dynamic displacement of the wheel relative to the vehicle body of the target vehicle, the unsprung mass of each suspension of the vehicle, and the acceleration of the unsprung mass includes:

[0016] Calculate the equivalent total stiffness of all elastic components at the wheel end of the corresponding suspension according to the stiffness of each elastic component, the lever ratio of each elastic component relative to the wheel, and the equivalent stiffness of the suspension bushings at the wheel end;

[0017] Calculate the change amount of the equivalent load at the wheel end of all elastic components of the suspension relative to the no-load and ready-to-drive state in real time according to the equivalent total stiffness of all elastic components of the suspension at the wheel end and the dynamic displacement of the wheel relative to the body of the target vehicle;

[0018] Or,

[0019] Obtain the change amount of the equivalent load at the wheel end of all elastic components of the suspension relative to the no-load and ready-to-drive state at the corresponding moment by suspension K&C characteristic simulation calculation or measure the vehicle to output the suspension load-displacement curve data, and look up the change amount of the equivalent load at the wheel end of all elastic components of the suspension relative to the no-load and ready-to-drive state from the suspension load-displacement curve data according to the dynamic displacement of the wheel relative to the body of the target vehicle. The suspension load-displacement curve data represents the change amount of the equivalent load at the wheel end of all elastic components corresponding to the dynamic displacement of the wheel relative to the body of the target vehicle in the no-load and ready-to-drive state;

[0020] Perform differential calculation according to the dynamic displacement of the wheel relative to the body of the target vehicle to obtain the relative movement speed of the wheel relative to the body of the target vehicle;

[0021] Calculate the relative movement speed during the operation of the shock absorber according to the relative movement speed of the wheel relative to the body of the target vehicle and the leverage ratio of the shock absorber relative to the wheel;

[0022] Look up the shock absorber damping force - shock absorber operation relative speed database according to the relative movement speed during the operation of the shock absorber to obtain the real-time damping force of the shock absorber;

[0023] Calculate the equivalent dynamic action load of the shock absorber damping force at the wheel end according to the real-time damping force of the shock absorber and the leverage ratio of the shock absorber relative to the wheel;

[0024] Calculate the dynamic load of the unsprung mass according to the unsprung mass of each suspension of the vehicle and the acceleration of the unsprung mass;

[0025] Calculate the transient vertical load of the tire of the target vehicle at the corresponding moment in real time according to the wheel weight of the target vehicle in the no-load and ready-to-drive state, the change amount of the equivalent load at the wheel end of all elastic components of the suspension relative to the no-load and ready-to-drive state, the equivalent dynamic action load of the shock absorber at the wheel end, and the dynamic load of the unsprung mass.

[0026] Optionally, when any of the following conditions is met, it is determined that the wheel of the target vehicle is not in contact with the ground:

[0027] The acceleration difference between the measured unsprung mass acceleration of the target vehicle and the unsprung mass acceleration calculated by using the vehicle wheel contact identification analysis model is within the preset deviation range;

[0028] The wheels of the target vehicle are compressed to the upper limit position of the suspension stroke and are in a suspended state off the ground;

[0029] The wheels of the target vehicle are stretched to the lower limit position of the suspension stroke and are in a suspended state off the ground.

[0030] Optionally, the method for calculating the transient vertical load of the vehicle tire further includes:

[0031] Obtain the stiffness of each elastic component of the target vehicle suspension, the leverage ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushings at the wheel end, the F-V characteristic data of the shock absorber damping force - shock absorber relative movement speed, and the leverage ratio of the shock absorber relative to the wheel from the vehicle parameters;

[0032] Obtain the dynamic displacement of the wheel relative to the body of the target vehicle, the unsprung mass of each suspension of the vehicle, and the acceleration of the unsprung mass from the vehicle signals;

[0033] Calculate the equivalent total stiffness of all elastic components of the corresponding suspension at the wheel end according to the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel end, and the equivalent stiffness of the suspension bushings at the wheel end;

[0034] Calculate the equivalent load change amount of all elastic components of the corresponding suspension relative to the unloaded and ready-to-drive state at the wheel end at the corresponding moment in real time according to the equivalent total stiffness of all elastic components of the suspension at the wheel end and the dynamic displacement of the wheel relative to the body of the target vehicle;

[0035] Or,

[0036] Obtain the equivalent load change amount of all elastic components of the corresponding suspension relative to the unloaded and ready-to-drive state at the wheel end at the corresponding moment from the suspension load-displacement curve data through suspension K&C characteristic simulation calculation or measured output of the vehicle, and the suspension load-displacement curve data represents the equivalent load change amount of all elastic components at the wheel end corresponding to the dynamic displacement of the wheel relative to the body of the target vehicle in the unloaded and ready-to-drive state;

[0037] Perform differential calculation according to the dynamic displacement of the wheel relative to the body of the target vehicle to obtain the relative movement speed of the wheel relative to the body of the target vehicle;

[0038] Calculate the relative movement speed during the actuation of the shock absorber according to the relative movement speed of the wheel relative to the body of the target vehicle and the leverage ratio of the shock absorber relative to the wheel;

[0039] Retrieve the F-V database of the shock absorber damping force - relative motion speed of the shock absorber during actuation based on the relative motion speed of the shock absorber during actuation to obtain the real-time damping force of the shock absorber;

[0040] Calculate the equivalent dynamic acting load of the shock absorber damping force at the wheel end based on the real-time damping force of the shock absorber and the leverage ratio of the shock absorber relative to the wheel;

[0041] Calculate the theoretical acceleration of the unsprung mass when the wheel is not in contact with the ground based on the change in the equivalent load at the wheel end of all elastic components of the suspension relative to the unloaded and ready-to-drive state, the equivalent dynamic acting load of the shock absorber damping force at the wheel end, the gravity of the unsprung mass, and the unsprung mass of the suspension;

[0042] Calculate the acceleration difference between the measured acceleration of the unsprung mass and the theoretical acceleration of the unsprung mass when the wheel is not in contact with the ground.

[0043] Compare the acceleration difference between the measured acceleration of the unsprung mass of the target vehicle and the acceleration of the unsprung mass calculated using the vehicle wheel contact identification analysis model with the preset acceleration deviation range. When it is less than the preset acceleration deviation range, it indicates that the wheel conforms to the characteristic of leaving the ground, and it is determined that the wheel is not in contact with the ground;

[0044] Optionally, the method for calculating the transient vertical load of the vehicle tire further includes:

[0045] Obtain the upper limit value of the upward travel of the suspension of the target vehicle relative to the unloaded and ready-to-drive state from the vehicle parameters;

[0046] Read the measured dynamic displacement of the wheel relative to the vehicle body of the target vehicle from the vehicle signals;

[0047] Calculate the displacement difference between the measured dynamic displacement of the wheel relative to the vehicle body of the target vehicle and the upper limit value of the upward travel of the suspension of the target vehicle relative to the unloaded and ready-to-drive state;

[0048] Differentiate the dynamic displacement of the wheel relative to the vehicle body of the target vehicle to obtain the relative motion speed between the sprung masses of the wheel relative to the vehicle body of the target vehicle;

[0049] Based on the load-displacement characteristic data of the suspension, determine the maximum elastic force of the suspension corresponding to the compression of the suspension from the unloaded and ready-to-drive state to the upper limit value of the upward travel of the wheel, and the gravity of the unsprung mass of the suspension, and calculate the unsprung acceleration corresponding to the suspension being compressed to the upper limit value of the upward travel;

[0050] Obtain the measured acceleration value of the unsprung mass from the vehicle signals;

[0051] Calculate the acceleration difference between the unsprung acceleration value corresponding to the suspension being compressed to the upper limit value of the upward travel and the measured acceleration of the unsprung mass;

[0052] When the displacement difference between the measured dynamic displacement of the wheel relative to the body of the target vehicle and the upper limit value of the upward jump stroke of the target vehicle suspension relative to the unloaded and ready state is less than or equal to the first preset displacement range, the relative movement speed between the springs is less than or equal to the first preset speed deviation range value, and the acceleration difference between the calculated value of the acceleration of the wheel below the spring when the suspension is compressed to the upper limit value of the upward jump stroke and the measured acceleration of the mass below the spring at the corresponding moment is less than or equal to the first preset acceleration difference range, it is determined that the wheel of the target vehicle is compressed to the limit position of the suspension stroke and the wheel is in a non-grounded state.

[0053] Optionally, the method for calculating the transient vertical load of the vehicle tire further includes:

[0054] Obtain the lower limit value of the downward jump stroke of the target vehicle suspension relative to the unloaded and ready state suspension from the vehicle parameters;

[0055] Read the measured dynamic displacement of the wheel relative to the body of the target vehicle from the vehicle signal;

[0056] Calculate the displacement difference between the measured dynamic displacement of the wheel relative to the body of the target vehicle and the lower limit value of the downward jump stroke of the target vehicle suspension relative to the unloaded and ready state;

[0057] Differentiate the dynamic displacement of the wheel relative to the body of the target vehicle to obtain the relative movement speed between the springs of the wheel relative to the body of the target vehicle;

[0058] Based on the load-displacement characteristic data of the suspension, determine the maximum elastic force of the suspension corresponding to when the suspension is stretched to the lower limit value of the downward jump stroke of the wheel relative to the unloaded and ready state, and the gravity of the mass below the spring of the suspension, and calculate the acceleration of the mass below the spring corresponding to when the suspension is stretched to the lower limit value of the downward jump stroke;

[0059] Obtain the measured acceleration value of the mass below the spring from the vehicle signal;

[0060] Calculate the acceleration difference between the calculated value of the acceleration of the mass below the spring corresponding to when the suspension is stretched to the lower limit value of the downward jump stroke and the measured acceleration of the mass below the spring;

[0061] When the displacement difference between the measured dynamic displacement of the wheel relative to the body of the target vehicle and the lower limit value of the downward jump stroke of the target vehicle suspension relative to the unloaded and ready state is less than or equal to the second preset displacement range, the relative movement speed between the springs is less than or equal to the second preset speed deviation range, and the acceleration difference between the calculated value of the acceleration of the mass below the spring corresponding to when the suspension is stretched to the lower limit value of the downward jump stroke and the measured acceleration of the mass below the spring at the corresponding moment is less than or equal to the second preset acceleration difference range, it is determined that the wheel of the target vehicle is stretched to the limit position of the suspension stroke and the wheel is in a non-grounded state.

[0062] In addition, to achieve the above object, the present invention also provides a device for calculating the transient vertical load of a vehicle tire, and the device for calculating the transient vertical load of a vehicle tire includes:

[0063] An acquisition module, configured to acquire vehicle signals during the operation of a target vehicle and vehicle parameters of the target vehicle;

[0064] A judgment module, configured to detect and calculate whether the wheels of the target vehicle are grounded;

[0065] An operation module, configured to, when the wheels of the target vehicle are grounded, calculate in real time the transient vertical load of the tires of the target vehicle at the corresponding moment according to the vehicle signals and vehicle parameters.

[0066] In addition, to achieve the above object, the present invention also provides a device for calculating the transient vertical load of a vehicle tire, and the device for calculating the transient vertical load of a vehicle tire includes: a memory, a processor, and a vehicle tire transient vertical load calculation program stored on the memory and executable on the processor, where the vehicle tire transient vertical load calculation program is configured to implement the vehicle tire transient vertical load calculation method as described above.

[0067] In addition, to achieve the above object, the present invention also provides a storage medium, on which a vehicle tire transient vertical load calculation program is stored, and when the vehicle tire transient vertical load calculation program is executed by a processor, it implements the vehicle tire transient vertical load calculation method as described above.

[0068] The present invention acquires vehicle signals during the operation of a target vehicle and vehicle parameters of the target vehicle; calculates and identifies whether the wheels of the target vehicle are grounded based on a wheel grounding identification calculation model; and when the wheels of the target vehicle are grounded, calculates in real time the transient vertical load of the tires of the target vehicle at the corresponding moment according to the vehicle signals and vehicle parameters based on the demonstrated and derived tire transient vertical load calculation method. Description of the Drawings

[0069] Figure 1 is a schematic structural diagram of the hardware operating environment and the device for calculating the transient vertical load of a vehicle tire involved in the embodiment solution of the present invention;

[0070] Figure 2 is a schematic flowchart of the first embodiment of the vehicle tire transient vertical load calculation method of the present invention;

[0071] Figure 3 is a schematic flowchart of the wheel grounding calculation judgment and the real-time transient vertical load calculation of the tire in an embodiment of the vehicle tire transient vertical load calculation method of the present invention;

[0072] Figure 4 Schematic diagram of the sensor installation position in an embodiment of the method for calculating the transient vertical load of a vehicle tire according to the present invention;

[0073] Figure 5 Schematic diagram of the system composition and principle of the wheel grounding identification calculation and the transient vertical load calculation of the vehicle tire in an embodiment of the method for calculating the transient vertical load of a vehicle tire according to the present invention;

[0074] Figure 6 Flow chart of the second embodiment of the method for calculating the transient vertical load of a vehicle tire according to the present invention;

[0075] Figure 7 Theoretical analysis model of the vertical load of a vehicle tire in an embodiment of the method for calculating the transient vertical load of a vehicle tire according to the present invention;

[0076] Figure 8 Schematic diagram of the curve of the spring lever ratio versus the wheel travel in an embodiment of the method for calculating the transient vertical load of a vehicle tire according to the present invention;

[0077] Figure 9 Flow chart of the third embodiment of the method for calculating the transient vertical load of a vehicle tire according to the present invention;

[0078] Figure 10 Theoretical analysis model of the wheel grounding identification calculation in an embodiment of the method for calculating the transient vertical load of a vehicle tire according to the present invention;

[0079] Figure 11 Schematic diagram of the curve of the change in the wheel grounding load - wheel end displacement relative to the no-load state in an embodiment of the method for calculating the transient vertical load of a vehicle tire according to the present invention;

[0080] Figure 12 Block diagram of the device structure in the first embodiment of the method for calculating the transient vertical load of a vehicle tire according to the present invention.

[0081] The realization, functional features, and advantages of the object of the present invention will be further described in conjunction with the embodiments with reference to the accompanying drawings. Detailed implementation manners

[0082] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0083] Referring to Figure 1 , Figure 1 Schematic diagram of the hardware operating environment and the structure of the device for calculating the transient vertical load of a vehicle tire involved in the embodiment solution of the present invention.

[0084] As Figure 1As shown in the figure, the vehicle tire transient vertical load 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. Among them, the communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 may include a display screen (Display) and an input unit such as a keyboard (Keyboard). Optionally, the user interface 1003 may also include a standard wired interface and a wireless interface. The network interface 1004 may optionally include a standard wired interface and 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 memory. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0085] Those skilled in the art can understand that Figure 1 the structure shown in does not constitute a limitation on the vehicle tire transient vertical load calculation device, and may include more or fewer components than shown in the figure, or combine some components, or have different component arrangements.

[0086] As Figure 1 shown, the memory 1005, as a storage medium, may include an operating system, a network communication module, a user interface module, and a vehicle tire transient vertical load calculation program.

[0087] In Figure 1 the vehicle tire transient vertical load calculation device shown, the network interface 1004 is mainly used for data communication with a network server; the user interface 1003 is mainly used for data interaction with a user; the processor 1001 and the memory 1005 in the vehicle tire transient vertical load calculation device of the present invention may be arranged in the vehicle tire transient vertical load calculation device. The vehicle tire transient vertical load calculation device calls the vehicle tire transient vertical load calculation program stored in the memory 1005 through the processor 1001 and executes the vehicle tire transient vertical load calculation method provided by the embodiments of the present invention.

[0088] The embodiments of the present invention provide a vehicle tire transient vertical load calculation method. Referring to Figure 2 , Figure 2 is a schematic flowchart of the first embodiment of the vehicle tire transient vertical load calculation method of the present invention.

[0089] In this embodiment, the execution subject of this embodiment can be a vehicle tire transient vertical load calculation device, which has functions such as data processing, data communication, and program operation. The calculation device can be a terminal device such as a computer. Of course, it can also be other devices with similar functions, and this embodiment does not limit this. For the convenience of description, this embodiment is described by taking the vehicle tire transient vertical load calculation device as an example.

[0090] In this embodiment, the vehicle tire transient vertical load calculation method includes the following steps:

[0091] Step S10: Obtain the vehicle signals and vehicle parameters of the target vehicle when it is running.

[0092] The vehicle parameters include the wheel weight of the target vehicle in the unloaded and ready-to-run state, the stiffness of each elastic component, the lever ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushings converted to the wheel end, the characteristic data of the shock absorber damping force - shock absorber relative movement speed, the lever ratio of the shock absorber relative to the wheel, the unsprung mass of each suspension of the vehicle, the upper limit value of the suspension upward travel of the target vehicle suspension relative to the unloaded and ready-to-run state, the maximum elastic force of the suspension corresponding to when the suspension is compressed to the upper limit value of the wheel upward travel relative to the unloaded and ready-to-run state, the lower limit value of the suspension downward travel of the target vehicle suspension relative to the unloaded and ready-to-run state, and the maximum elastic force of the suspension corresponding to when the suspension is stretched to the lower limit value of the wheel downward travel relative to the unloaded and ready-to-run state.

[0093] The vehicle signals include the dynamic displacement of each wheel relative to the vehicle body of the target vehicle and the acceleration of the unsprung mass of each suspension.

[0094] Step S20: Detect and calculate and identify whether the wheels of the target vehicle are grounded.

[0095] It should be noted that the vehicle tire being separated from the ground contact will have extremely adverse effects on the vehicle's handling performance, stability, power performance, braking performance, etc. Moreover, it is also necessary to ensure that the wheels are grounded before calculating the real-time transient vertical load of the tire. Based on this background, a method for real-time calculating and identifying whether the wheels are grounded is proposed.

[0096] In this embodiment, in combination with Figure 3 the detection and calculation and identification of whether the wheels of the target vehicle are grounded and the overall process of this embodiment of the present invention are described.

[0097] Such as Figure 3As shown in the figure, after obtaining the necessary vehicle parameters and vehicle signals, the wheel grounding identification calculation model and calculation identification method described in the present invention are used to determine whether the wheel is grounded, including: whether the relative body is compressed to the stroke limit and the wheel is off the ground, whether the wheel is stretched relative to the body to the stroke limit and the wheel is off the ground, and whether the wheel is grounded under the condition that the suspension is not compressed to the limit or stretched to the limit based on the wheel grounding identification calculation model. If all the above calculation and identification steps determine that the wheel is grounded, the real-time transient vertical load of the tire is further calculated according to vehicle signals and vehicle parameters such as the height between springs, the acceleration under the spring, and the relative speed of the shock absorber. Conversely, if it is determined that the wheel is not grounded, it can be considered that the transient vertical load Ft = 0.

[0098] Further, the above-mentioned height between springs and the acceleration between springs can be obtained by height sensors and acceleration sensors provided on the vehicle. The settings of the height sensors and acceleration sensors are as Figure 4 shown. In Figure 4 , A is the height sensor, B is the acceleration sensor, and Ft represents the transient vertical load of the tire. Figure 4 It is a schematic diagram of the installation of sensors on a single wheel. Further, as Figure 5 shown, the system composition and principle of the vehicle wheel grounding identification calculation and tire transient vertical load calculation are described. Referring to Figure 5 , Figure 5 , FL, FR, RL, and RR in it are the four suspensions corresponding to the vehicle. Height sensors and acceleration sensors are installed on each suspension. The controller of the whole vehicle communicates through the CAN network to calibrate and output the vertical load of the vehicle. The controller includes an MCU micro-control unit module, a power supply module, a communication module, a constant current module, etc.

[0099] Step S30: When the wheel of the target vehicle is grounded, calculate the transient vertical load of the tire of the target vehicle at the corresponding moment according to the vehicle signal and vehicle parameter.

[0100] In a specific implementation, if the wheel of the target vehicle is grounded, in this embodiment, the transient vertical load of the tire can be calculated according to the wheel weight of the target vehicle in the unloaded and ready state, the stiffness of each elastic component, the lever ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushings at the wheel end, the F-V characteristic data of the shock absorber damping force - shock absorber relative movement speed, and the lever ratio of the shock absorber relative to the wheel. These vehicle parameters and the dynamic displacement of the wheel relative to the body of the target vehicle and the acceleration of the mass under the spring extracted from the vehicle signal. Conversely, if the wheel of the target vehicle is not grounded, it can be considered that the transient vertical load at this time is 0.

[0101] In this embodiment, vehicle signals and vehicle parameters of the target vehicle during operation are obtained; based on a wheel grounding identification calculation model, it is calculated and identified whether the wheels of the target vehicle are grounded; when the wheels of the target vehicle are grounded, the transient vertical load of the tires of the target vehicle at the corresponding moment is calculated in real time according to the vehicle signals and vehicle parameters.

[0102] Reference Figure 6 , Figure 6 is a schematic flowchart of the second embodiment of a method for calculating the transient vertical load of a vehicle tire according to the present invention.

[0103] Based on the above first embodiment, in the method for calculating the transient vertical load of the vehicle tire in this embodiment, the step S30 includes:

[0104] Step S301: Extract the dynamic displacement of the wheel relative to the body of the target vehicle and the acceleration of the unsprung mass from the vehicle signals.

[0105] In specific implementation, in this embodiment, when calculating the transient vertical load, it is necessary to first extract the dynamic displacement of the wheel relative to the body of the target vehicle and the acceleration of the unsprung mass from the vehicle signals.

[0106] Step S302: Calculate the transient vertical load of the tires of the target vehicle at the corresponding moment according to the wheel weight of the target vehicle in the 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 bushings at the wheel end, the characteristic data of the shock absorber damping force - shock absorber relative movement speed, the leverage ratio of each shock absorber relative to the wheel, the dynamic displacement of the wheel relative to the body of the target vehicle, the unsprung mass of each vehicle suspension, and the acceleration of the unsprung mass, etc.

[0107] In a specific implementation, after obtaining the wheel weights of the target vehicle in the unloaded and ready state, the stiffnesses of the respective elastic components, the lever ratios of the respective elastic components relative to the wheels, the total stiffness of the suspension link bushings at the wheel ends, the characteristic data of the shock absorber damping force - shock absorber relative movement speed, the lever ratio of the shock absorber relative to the wheel, the dynamic displacement of the wheel relative to the target vehicle body, the unsprung masses of the respective suspensions of the vehicle, and the acceleration of the unsprung masses, etc., according to the stiffnesses of the respective elastic components, the lever ratios of the respective elastic components relative to the wheels, and the equivalent stiffness of the suspension bushings at the wheel ends, the equivalent total stiffness of all the elastic components of the corresponding suspension at the wheel end can be calculated; according to 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, the equivalent load change amount of all the elastic components of the corresponding suspension relative to the unloaded and ready state at the wheel end at the corresponding moment is calculated in real time; in a specific implementation, the suspension load - wheel end displacement curve data can also be obtained through suspension K&C characteristic simulation calculation or by actually measuring the vehicle, and the curve data is as Figure 11 shown, and then the equivalent load change amount of all the elastic components of the corresponding suspension relative to the unloaded and ready state at the wheel end at the corresponding moment is directly retrieved through the dynamic displacement (Z b -Z t ) of the wheel relative to the target vehicle body; by performing differential calculation on the dynamic displacement of the wheel relative to the target vehicle body, the relative movement speed of the wheel relative to the target vehicle body is obtained; according to the relative movement speed of the wheel relative to the target vehicle body and the lever ratio of the shock absorber relative to the wheel, the relative movement speed when the shock absorber acts is calculated; according to the relative movement speed when the shock absorber acts, the shock absorber damping force - shock absorber actuation relative speed database is retrieved to obtain the real-time damping force of the shock absorber; according to the real-time damping force of the shock absorber and the lever ratio of the shock absorber relative to the wheel, the equivalent dynamic action load of the shock absorber damping force at the wheel end is calculated; according to the unsprung masses of the respective suspensions of the vehicle and the acceleration of the unsprung masses, the dynamic load of the unsprung masses is calculated; according to the wheel weights of the target vehicle in the unloaded and ready state, the equivalent load change amount of all the elastic components of the suspension relative to the unloaded and ready state at the wheel end, the equivalent dynamic action load of the shock absorber at the wheel end, and the dynamic load of the unsprung masses, the transient vertical load of the tires of the target vehicle at the corresponding moment is calculated in real time.

[0108] It should be noted that the calculation formula of the tire transient vertical load can be derived through the Figure 7 theoretical analysis model of the vehicle tire vertical load shown as follows, and the specific derivation process is as follows:

[0109]

[0110]

[0111] From (2), it can be obtained that

[0112]

[0113] From (1) and (2), it can be obtained that

[0114]

[0115] Substituting (3) into (4), the following formula (5) can be obtained

[0116]

[0117] Meanwhile, as Figure 7 shown, considering the suspension of a quarter vehicle as an overall analysis, the following dynamic equation can be established

[0118]

[0119] Substituting (5) into (6), the following formula (7) can be obtained

[0120]

[0121] Thus, the calculation expression of the tire vertical load can be obtained as

[0122]

[0123] In formulas (1) to (8), the descriptions of each physical quantity are as follows

[0124] M b is the sprung mass of the suspension (quarter body mass), K s is the suspension stiffness, C d is the suspension damping coefficient, K t is the tire radial stiffness, C t is the tire damping coefficient, m t is the unsprung mass of the suspension, Z b is the displacement of the sprung mass, Z t is the wheel displacement, Z r is the road surface roughness input, F d is the external disturbance input, F t is the tire transient vertical load

[0125] It can be seen from the above formula (8) that the vertical wheel load can be composed of the gravity of the sprung mass, the gravity of the unsprung mass, 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. However, as can be seen from the above formula, the tire transient vertical load, which is difficult to detect and has an extremely fast change speed, can theoretically be converted into physical quantities that are easy to detect and have a mature and reliable acquisition method for conversion calculation, and can theoretically be detected in real time and accurately calculated.

[0126] Based on the above theoretical derivation, further, the present invention considers the engineering implementation method. Relatively speaking, the no-load state is selected as the reference state for calculation based on the above formula, and the following formula (9) is used to calculate the tire transient vertical load based on the theory of the above formula (8):

[0127] F t =G Mb +G mt +ΔF Ks +ΔF Cd +ΔF t (9)

[0128] It should be noted that formula (9) is the final formula used for calculating the transient vertical load.

[0129] In formula (9), G Mb =M b g represents the gravity borne by the sprung mass M b , g is the acceleration due to gravity, and M b represents the sprung mass of a single suspension in the no-load and ready-to-run state; G mt =m t g represents the gravity borne by the unsprung mass of a single suspension. Among them, m t represents the unsprung mass of a single suspension in the no-load and ready-to-run state. In specific implementation, the wheel weights at the ground contact points of each wheel of the target vehicle in the no-load and ready-to-run state can be directly measured, and the wheel weights can be equivalently substituted for G Mb +G mt .

[0130] In formula (9), ΔF Cd represents the equivalent dynamic action load of the shock absorber damping force at the wheel end. Comparing with formula (8), In specific implementation, the equivalent dynamic action load of the shock absorber damping force at the wheel end can be calculated from the damping force - shock absorber relative movement speed data of the shock absorber and the lever ratio of the shock absorber, that is Among them, ΔF Cd0 represents the real-time damping force of the shock absorber, and ρ dIndicates the lever ratio of the shock absorber relative to the wheel. The real-time damping force of the shock absorber can be obtained by looking up the damping force-dynamic relative speed database of the shock absorber according to the relative movement speed during the operation of the shock absorber. The relative movement speed during the operation of the shock absorber can be obtained in the following way: the dynamic displacement (Z b -Z t ) of the wheel relative to the body of the target vehicle can be obtained from the signal collected by the height sensor, and then by differentiating the dynamic displacement of the body of the target vehicle, the relative movement speed of the body of the target vehicle can be obtained, that is, differentiating Z b -Z t to obtain Then, multiply this value by the lever ratio ρ d of the shock absorber relative to the wheel to obtain the relative movement speed during the operation of the shock absorber.

[0131] In Equation (9), ΔF Ks represents the change in the equivalent load at the wheel end of all elastic components of the suspension relative to the unloaded and ready-to-drive state. Comparing with Equation (8), ΔF Ks =K s ΔZ s =K s (Z b -Z t ), where K s represents the equivalent total stiffness of all elastic components of the suspension at the wheel end, and Z b -Z t represents the dynamic displacement of the wheel relative to the body of the target vehicle. Further, where K si represents the stiffness of each elastic component, ρ si represents the lever ratio of each elastic component relative to the wheel. For example, as Figure 4 shown, the lever ratio of the spring relative to the wheel end is L1 / L2, where L2 is the stroke at the wheel end and L1 is the deformation of the spring when the wheel end stroke is L2; for accurate calculation, the lever ratios of each elastic component relative to different strokes at the wheel end can be calculated and output by the suspension K&C characteristic simulation model, as Figure 8 shown; K b represents the equivalent stiffness of each bushing of the suspension at the wheel end. In specific implementation, in addition to using the above formula to calculate ΔF Ks at different positions of the suspension stroke, the suspension load-wheel end displacement curve data can also be obtained through suspension K&C characteristic simulation calculation or actual measurement. The curve data is as Figure 11 shown, and then the elastic force corresponding to the wheel end stroke can be directly obtained by looking up the dynamic displacement (Z b -Z t ) of the wheel relative to the body of the target vehicle;

[0132] Further, ΔFt represents the dynamic load of the unsprung mass, where m t represents the unsprung mass, represents the vibration acceleration of the unsprung mass, which can be measured by an acceleration sensor.

[0133] In this embodiment, after obtaining the wheel weight of the target vehicle in the 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 bushings at the wheel end, the characteristic data of the shock absorber damping force - shock absorber relative movement speed, the leverage ratio of the shock absorber relative to the wheel, the dynamic displacement of the wheel relative to the target vehicle body, the unsprung mass of each suspension of the vehicle, and the acceleration of the unsprung mass, etc., according to the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel, and the equivalent stiffness of the suspension bushings at the wheel end, the equivalent total stiffness of all elastic components of the corresponding suspension at the wheel end can be calculated; according to the equivalent total stiffness of all elastic components of the suspension at the wheel end and the dynamic displacement of the wheel relative to the target vehicle body, the equivalent load change amount of all elastic components of the corresponding suspension relative to the unloaded and ready state at the wheel end at the corresponding moment is calculated in real time; by differentiating the dynamic displacement of the wheel relative to the target vehicle body, the relative movement speed of the wheel relative to the target vehicle body is obtained; according to the relative movement speed of the wheel relative to the target vehicle body and the leverage ratio of the shock absorber relative to the wheel, the relative movement speed when the shock absorber acts is calculated; according to the relative movement speed when the shock absorber acts, the shock absorber damping force - shock absorber actuation relative speed database is queried to obtain the real-time damping force of the shock absorber; according to the real-time damping force of the shock absorber and the leverage ratio of the shock absorber relative to the wheel, the equivalent dynamic action load of the shock absorber damping force at the wheel end is calculated; according to the unsprung mass of each suspension of the vehicle and the acceleration of the unsprung mass, etc., the dynamic load of the unsprung mass is calculated; according to the wheel weight of the target vehicle in the unloaded and ready state, the equivalent load change amount of all elastic components of the suspension relative to the unloaded and ready state at the wheel end, the equivalent dynamic action load of the shock absorber at the wheel end, and the dynamic load of the unsprung mass, the transient vertical load of the tire of the target vehicle at the corresponding moment is calculated in real time.

[0134] Reference Figure 9 , Figure 9 is a schematic flow chart of the third embodiment of a method for calculating the transient vertical load of a vehicle tire according to the present invention.

[0135] Based on the above first or second embodiment, a third embodiment of a method for calculating the transient vertical load of a vehicle tire according to the present invention is proposed.

[0136] In this embodiment, the step S20 specifically includes:

[0137] The step S201: When any of the following conditions is met, it is determined that the wheels of the target vehicle are not in contact with the ground:

[0138] The acceleration difference between the measured unsprung mass acceleration of the target vehicle and the unsprung mass acceleration calculated by the wheel grounding identification analysis model is within a preset deviation range; the wheels of the target vehicle are compressed to the upper limit position of the suspension stroke and are in a suspended state off the ground; the wheels of the target vehicle are stretched to the lower limit position of the suspension stroke and are in a suspended state off the ground.

[0139] In a specific implementation, in this embodiment, three methods are used to detect and calculate whether the wheels are in contact with the ground.

[0140] The first method is to calculate and identify whether the wheels are in contact with the ground through a wheel grounding identification analysis model.

[0141] Specifically, first, according to the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel end, 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; according to the equivalent total stiffness of all elastic components of the suspension at the wheel end and the dynamic displacement of the wheel relative to the body of the target vehicle, calculate the equivalent load change amount of all elastic components of the corresponding suspension at the wheel end relative to the unloaded and ready-to-drive state in real time.

[0142] In addition, in this embodiment, other methods can also be adopted to obtain the equivalent load change amount of all elastic components at the wheel end relative to the unloaded and ready-to-drive state. For example, through suspension K&C characteristic simulation calculation or measuring and outputting the suspension load-displacement curve data of the vehicle in the unloaded and ready-to-drive state. The curve data is as Figure 11 shown. This data represents the equivalent load change amount of all elastic components at the wheel end corresponding to the dynamic displacement of the wheel relative to the body of the target vehicle (representing the different wheel end strokes of the wheel end relative to the unloaded and ready-to-drive state). The equivalent load change amount of all elastic components of the corresponding suspension at the wheel end relative to the unloaded and ready-to-drive state at the corresponding moment can be directly obtained through the dynamic displacement of the wheel relative to the body of the target vehicle (Z b -Z t );

[0143] Perform differential calculation according to the dynamic displacement of the wheel relative to the body of the target vehicle to obtain the relative movement speed of the wheel relative to the body of the target vehicle; calculate the relative movement speed during the operation of the shock absorber according to the relative movement speed of the wheel relative to the body of the target vehicle and the leverage ratio of the shock absorber relative to the wheel; look up the database of shock absorber damping force - relative movement speed during the operation of the shock absorber according to the relative movement speed during the operation of the shock absorber to obtain the real-time damping force of the shock absorber; calculate the equivalent dynamic action load of the shock absorber damping force at the wheel end according to the real-time damping force of the shock absorber and the leverage ratio of the shock absorber relative to the wheel.

[0144] According to the change amount of the equivalent load of all elastic components of the suspension at the wheel end under the no-load and ready-to-drive state, the equivalent dynamic action load of the shock absorber damping force at the wheel end, the gravity of the unsprung mass, and the unsprung mass of the suspension, calculate the theoretical acceleration of the unsprung mass when the wheel is not in contact with the ground;

[0145] Calculate the acceleration difference between the measured acceleration of the unsprung mass and the theoretical acceleration of the unsprung mass when the wheel is not in contact with the ground;

[0146] Compare the acceleration difference between the measured acceleration of the unsprung mass of the target vehicle and the acceleration of the unsprung mass calculated using the vehicle wheel-off-the-ground model with the preset acceleration deviation range. When it is less than the preset acceleration deviation range, it indicates that the wheel conforms to the characteristics of being off the ground, and it is determined that the wheel is not in contact with the ground.

[0147] In this embodiment, when the wheel is not in contact with the ground, that is, when it is disengaged, the motion equation of the unsprung mass and the ground contact identification calculation method are derived as follows.

[0148] When the vehicle travels over a pothole or a raised step on the road surface, the wheel (or the unsprung mass) is lifted or stretched downward, and the wheel is disengaged from the ground. Then, both the elastic force and the damping force between the wheel and the ground are 0. Therefore, based on the physical model shown in Figure 10 Extract features to identify and determine whether the wheel is disengaged from the ground. Figure 10 In, F d Is the external transient impact force received by the suspension.

[0149] When the wheel is disengaged from the ground, the unsprung mass is only subject to the suspension spring force, gravity, and damping force. The differential motion equation is as follows.

[0150]

[0151] From Equation (10), we can obtain

[0152]

[0153] Among them, Is the theoretical unsprung acceleration of the unsprung mass when the wheel is disengaged from the ground. m t g represents the gravity of a single unsprung mass of the suspension under the no-load and ready-to-drive state. -K s (Z t -Z b ) represents the equivalent acting force of all elastic components of the suspension at the wheel end relative to the no-load and ready-to-drive state. -C d (Z t -Z b ) represents the equivalent acting force of the real-time damping force at the wheel end. m tis the unsprung mass.

[0154] Equation (11) theoretically proves the composition of the forces acting on the unsprung mass when the wheel is detached from the ground. Further, referring to Equation (9) and considering a more accurate and simplified calculation implementation method in engineering, in a specific implementation, the following formula is used to calculate the theoretical acceleration of the unsprung mass when the wheel is detached from the ground:

[0155]

[0156] In Equation (12), ΔF Ks represents the equivalent load change of all elastic components of the suspension at the wheel end relative to the unloaded curb state, and ΔF Cd represents the equivalent dynamic action load of the shock absorber damping force at the wheel end, and m t g represents the gravity acting on the unsprung mass of a single suspension.

[0157] In a specific implementation, there are multiple ways or approaches to obtain ΔF Ks . The following two optional methods are described in this embodiment: The first optional method is to first calculate the equivalent total stiffness of all elastic components of the corresponding suspension at the wheel end according to the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel end, and the equivalent stiffness of the suspension bushing at the wheel end; calculate the equivalent load change of all elastic components of the corresponding suspension at the wheel end relative to the unloaded curb state in real time according to the equivalent total stiffness of all elastic components of the suspension at the wheel end and the dynamic displacement of the wheel relative to the body of the target vehicle; The second optional method is that the equivalent load change of all the above-mentioned elastic components of the suspension at the wheel end relative to the unloaded curb state can also be obtained through the suspension K&C characteristic simulation calculation or the measured suspension load-displacement curve data, as shown in the curve data Figure 11 . This data represents the equivalent load change of all elastic components at the wheel end corresponding to the dynamic displacement of the wheel relative to the body of the target vehicle (representing different wheel end strokes of the wheel end relative to the unloaded curb state). The equivalent load change of all elastic components of the suspension at the wheel end relative to the unloaded curb state at the corresponding moment can be directly obtained through the dynamic displacement of the wheel relative to the body of the target vehicle (Z b -Z t );

[0158] In a specific implementation, ΔF CdIt can be obtained in the following manner: perform differential calculation based on the dynamic displacement of the wheel relative to the body of the target vehicle to obtain the relative motion speed of the wheel relative to the body of the target vehicle; calculate the relative motion speed during the actuation of the shock absorber based on the relative motion speed of the wheel relative to the body of the target vehicle and the lever ratio of the shock absorber relative to the wheel; look up the F-V database of the shock absorber damping force - relative motion speed during the actuation of the shock absorber according to the relative motion speed during the actuation of the shock absorber to obtain the real-time damping force of the shock absorber; calculate the equivalent dynamic action load of the shock absorber damping force at the wheel end based on the real-time damping force of the shock absorber and the lever ratio of the shock absorber relative to the wheel.

[0159] In a specific implementation, after obtaining the measured unsprung mass acceleration and the theoretical unsprung mass acceleration when the wheel leaves the ground, calculate the acceleration difference between the measured unsprung mass acceleration and the theoretical unsprung mass acceleration, and then compare this acceleration difference with a preset deviation range. If the acceleration difference is within the preset deviation range, it is determined that the wheel leaves the ground. For example, the following formula can be used to calculate and judge whether the wheel leaves the ground:

[0160]

[0161] where is the theoretical unsprung mass acceleration when the wheel leaves the ground calculated by formula (13), a t is the measured unsprung mass acceleration, a tol is the preset acceleration deviation range, which can be set to 0 or other values according to the actual situation, and this is not limited in this embodiment.

[0162] Further, in the second method of this embodiment, it is determined whether the wheel is grounded by calculating and identifying whether the wheel of the target vehicle is compressed to the upper limit position of the suspension stroke and is in a state of leaving the ground and hanging in the air.

[0163] Specifically, obtain the upper limit value of the upward jump stroke of the suspension of the target vehicle relative to the unloaded curb weight state from the vehicle parameters; read the measured dynamic displacement of the wheel relative to the body of the target vehicle from the vehicle signals; calculate the displacement difference between the measured dynamic displacement of the wheel relative to the body of the target vehicle and the upper limit value of the upward jump stroke of the suspension of the target vehicle relative to the unloaded curb weight state;

[0164] Differentiate the dynamic displacement of the wheel relative to the body of the target vehicle to obtain the relative motion speed between the sprung masses of the wheel relative to the body of the target vehicle.

[0165] Based on the load-displacement characteristic data of the suspension, determine the maximum elastic force of the suspension corresponding to when the suspension is compressed to the upper limit value of the wheel bounce stroke relative to the unloaded curb state, and the gravity borne by the unsprung mass of the suspension, and calculate the unsprung acceleration corresponding to when the suspension is compressed to the upper limit value of the bounce stroke; obtain the measured acceleration value of the unsprung mass from the vehicle signals; calculate the acceleration difference between the calculated value of the unsprung acceleration corresponding to when the suspension is compressed to the upper limit value of the bounce stroke and the measured acceleration of the unsprung mass.

[0166] When the displacement difference between the measured dynamic displacement of the wheel relative to the body of the target vehicle and the upper limit value of the bounce stroke of the target vehicle suspension relative to the unloaded curb state is less than or equal to the first preset displacement range, the interleaf movement speed is less than or equal to the first preset speed range value, and the acceleration difference between the calculated value of the unsprung acceleration corresponding to when the suspension is compressed to the upper limit value of the bounce stroke and the measured acceleration of the unsprung mass at the corresponding moment is less than or equal to the first preset acceleration difference range, it is determined that the wheel of the target vehicle is compressed to the limit position of the suspension stroke and the wheel is in a non-grounded state.

[0167] Specifically, the following calculation and identification method can be adopted to calculate and judge whether the wheel is grounded in the second method.

[0168] |(Z t -Z b )-L up |≤ΔL tol_up (14)

[0169]

[0170] |(a t -a u )|≤Δa up (16)

[0171] In the above formulas (14) to (16), (Z t -Z b ) represents the dynamic displacement of the wheel relative to the body of the target vehicle, L up is the upper limit value of the wheel bounce stroke relative to the unloaded curb state, ΔL tol_up is the first preset stroke deviation threshold; is the relative interleaf movement speed of the wheel relative to the body, ΔV tol_up is the first preset speed deviation threshold; (a t -a u ) is the acceleration difference, Δa up is the first preset difference threshold, a t is the measured acceleration of the unsprung mass, a u is the calculated value of the unsprung acceleration, and the calculation of a u is shown in the following formula:

[0172] a u =(F s_up +m t ·g) / m t (17)

[0173] F s_up represents the limit value of the elastic force in the compression section of the suspension load-displacement curve, and the maximum input representative value of the relative compression section of the wheel end to the vehicle body during vehicle development can be used. m t is the unsprung mass.

[0174] Further, in the third method of this embodiment, it is determined whether the wheel of the target vehicle is grounded by calculating and identifying whether the wheel of the target vehicle is stretched to the lower limit position of the suspension stroke and is in a state of being off the ground and suspended.

[0175] Specifically, obtain the lower limit value of the downward jump stroke of the target vehicle suspension relative to the unloaded curb weight state from the vehicle parameters; read the measured dynamic displacement of the wheel relative to the vehicle body of the target vehicle from the vehicle signals; calculate the displacement difference between the measured dynamic displacement of the wheel relative to the vehicle body of the target vehicle and the lower limit value of the downward jump stroke of the target vehicle suspension relative to the unloaded curb weight state;

[0176] Differentiate the dynamic displacement of the wheel relative to the vehicle body of the target vehicle to obtain the relative motion speed between the sprung masses of the wheel relative to the vehicle body of the target vehicle;

[0177] Based on the load-displacement characteristic data of the suspension, determine the maximum elastic force of the suspension corresponding to when the suspension is stretched to the lower limit value of the wheel downward jump stroke relative to the unloaded curb weight state, and the gravity received by the unsprung mass of the suspension, and calculate the unsprung acceleration corresponding to when the suspension is stretched to the lower limit value of the downward jump stroke; obtain the measured acceleration value of the unsprung mass from the vehicle signals; calculate the acceleration difference between the calculated value of the unsprung acceleration corresponding to when the suspension is stretched to the lower limit value of the downward jump stroke and the measured acceleration of the unsprung mass;

[0178] When the displacement difference between the measured dynamic displacement of the wheel relative to the vehicle body of the target vehicle and the lower limit value of the downward jump stroke of the target vehicle suspension relative to the unloaded curb weight state is less than or equal to the second preset displacement range, the relative motion speed between the sprung masses is less than or equal to the second preset speed range, and the acceleration difference between the calculated value of the unsprung acceleration corresponding to when the suspension is stretched to the lower limit value of the downward jump stroke and the measured acceleration of the unsprung mass at the corresponding moment is less than or equal to the second preset acceleration difference range, it is determined that the wheel of the target vehicle is stretched to the limit position of the suspension stroke and the wheel is in a non-grounded state.

[0179] Specifically, the following calculation and identification method can be adopted to calculate and judge whether the wheel is grounded in the third method.

[0180] |(Z t -Z b )-L d |≤ΔL tol_d (18)

[0181]

[0182] |(a t -a d )|≤Δa d (20)

[0183] In the above formulas (18) to (20), the dynamic displacement of the wheel relative to the body of the target vehicle is (Z t -Z b ), L d is the lower limit value of the wheel jounce travel in the unloaded and ready state, ΔL tol_d is the second preset travel deviation threshold; is the relative motion speed between the wheel and the body, ΔV tol_d is the second preset speed threshold; (a t -a d ) is the acceleration difference, Δa d is the second preset acceleration difference threshold, a t is the measured acceleration of the unsprung mass, a d is the unsprung acceleration value, and the calculation is as follows;

[0184] a d =(F s_d +m t ·g) / m t (21)

[0185] F s_d represents the limit value of the elastic force in the stretching section of the suspension load-displacement curve. The specific threshold setting can be set according to actual detection requirements, and this is not limited in this embodiment.

[0186] In this embodiment, the grounding of the vehicle wheels is calculated and identified through the above three methods, including: the acceleration difference between the measured unsprung mass acceleration of the target vehicle and the theoretical unsprung mass acceleration calculated using the vehicle wheel grounding identification model is within the preset deviation range; the wheels of the target vehicle are compressed to the upper limit position of the suspension stroke and are in a suspended state off the ground; the wheels of the target vehicle are stretched to the lower limit position of the suspension stroke and are in a suspended state off the ground. The vehicle driving process includes two situations: wheel grounding and non-grounding. By calculating and identifying the vehicle grounding through the above methods, a reliable real-time detection and calculation scheme for vehicle grounding is provided; moreover, by performing vehicle grounding identification calculation before detecting and calculating the transient vertical load of the vehicle tire, the accuracy and reliability of the results can be improved.

[0187] In addition, an embodiment of the present invention further provides a storage medium, on which a vehicle tire transient vertical load calculation program is stored. When the vehicle tire transient vertical load calculation program is executed by a processor, the steps of the vehicle tire transient vertical load calculation method as described above are implemented.

[0188] Since this storage medium adopts all the technical solutions of the above all embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, and will not be elaborated here one by one.

[0189] Refer to Figure 12 , Figure 12 which is the structural block diagram of the first embodiment of the vehicle tire transient vertical load calculation device of the present invention.

[0190] As Figure 12 shown, the vehicle tire transient vertical load calculation device proposed by the embodiment of the present invention includes:

[0191] An acquisition module 10, configured to acquire vehicle signals and vehicle parameters of the target vehicle during operation.

[0192] A judgment module 20, configured to calculate and identify whether the wheels of the target vehicle are grounded.

[0193] An operation module 30, configured to, when the wheels of the target vehicle are grounded, calculate the transient vertical load of the tires of the target vehicle at the corresponding moment in real time according to the vehicle signals and vehicle parameters.

[0194] In this embodiment, vehicle signals and vehicle parameters of the target vehicle during operation are acquired; based on the wheel grounding identification calculation model, it is calculated and identified whether the wheels of the target vehicle are grounded; when the wheels of the target vehicle are grounded, based on the derived tire transient vertical load calculation method, the transient vertical load of the tires of the target vehicle at the corresponding moment is calculated in real time according to the vehicle signals and vehicle parameters.

[0195] In one embodiment, the vehicle parameters include the wheel weights of the target vehicle in the unloaded and ready state, the stiffnesses of the respective elastic components, the lever ratios of the respective elastic components relative to the wheels, the total stiffness of the suspension link bushings transferred to the wheel ends, the characteristic data of the shock absorber damping force - shock absorber relative movement speed, the lever ratio of the shock absorber relative to the wheel, and the unsprung masses of the respective suspensions of the vehicle; the vehicle signals include the dynamic displacement of the wheel relative to the body of the target vehicle and the acceleration of the unsprung mass.

[0196] The operation module 30 is further configured to calculate the transient vertical load of the target vehicle tire at the corresponding moment from the wheel weights of the target vehicle in the unloaded and ready state, the stiffnesses of the respective elastic components, the lever ratios of the respective elastic components relative to the wheels, the total stiffness of the suspension link bushings at the wheel ends, the characteristic data of the shock absorber damping force - shock absorber relative movement speed, the lever ratio of the shock absorber relative to the wheel, the dynamic displacement of the wheel relative to the body of the target vehicle, the unsprung masses of the respective suspensions of the vehicle, and the acceleration of the unsprung mass.

[0197] In one embodiment, the operation module 30 is further configured to calculate the equivalent total stiffness of all the elastic components of the corresponding suspension at the wheel end according to the stiffnesses of the respective elastic components, the lever ratios of the respective elastic components relative to the wheels, and the equivalent stiffness of the suspension bushings at the wheel ends; and calculate the equivalent load change amount of all the elastic components of the corresponding suspension relative to the unloaded and ready state at the wheel end at the corresponding moment in real time according to 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 body of the target vehicle;

[0198] Or,

[0199] Obtain through suspension K&C characteristic simulation calculation or output suspension load - displacement curve data by actually measuring the vehicle, and look up the equivalent load change amount of all the elastic components of the corresponding suspension relative to the unloaded and ready state at the wheel end at the corresponding moment from the suspension load - displacement curve data according to the dynamic displacement of the wheel relative to the body of the target vehicle, where the suspension load - displacement curve data represents the equivalent load change amount of all the elastic components at the wheel end corresponding to the dynamic displacement of the wheel relative to the body of the target vehicle in the unloaded and ready state;

[0200] Differential calculation is performed based on the dynamic displacement of the wheel relative to the body of the target vehicle to obtain the relative movement speed of the wheel relative to the body of the target vehicle; the relative movement speed during the actuation of the shock absorber is calculated based on the relative movement speed of the wheel relative to the body of the target vehicle and the leverage ratio of the shock absorber relative to the wheel; the real-time damping force of the shock absorber is obtained by querying the shock absorber damping force - shock absorber actuation relative speed database based on the relative movement speed during the actuation of the shock absorber; the equivalent dynamic action 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 leverage ratio of the shock absorber relative to the wheel; the dynamic load of the unsprung mass is calculated based on the unsprung mass of each suspension of the vehicle and the acceleration of the unsprung mass; the transient vertical load of the tire 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-for-use state, the equivalent load change amount of all elastic components of the suspension relative to the unloaded and ready-for-use state at the wheel end, the equivalent dynamic action load of the shock absorber at the wheel end, and the dynamic load of the unsprung mass.

[0201] In an embodiment, the determination module 20 is further configured to determine that the wheel of the target vehicle is not in contact with the ground when any of the following conditions is met: the acceleration difference between the measured unsprung mass acceleration of the target vehicle and the theoretical unsprung mass acceleration calculated using the vehicle wheel contact identification model is within a preset deviation range; the wheel of the target vehicle is compressed to the upper limit position of the suspension stroke and is in a suspended state off the ground; the wheel of the target vehicle is stretched to the lower limit position of the suspension stroke and is in a suspended state off the ground.

[0202] In one embodiment, the determination module 20 is further configured to read from the vehicle parameters and vehicle signals the stiffness of each elastic component of the target vehicle suspension obtained from the vehicle parameters, the leverage ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushings at the wheel end, the F-V characteristic data of the shock absorber damping force - shock absorber relative movement speed, and the leverage ratio of the shock absorber relative to the wheel; obtain from the vehicle signals the dynamic displacement of the wheel relative to the target vehicle body, the unsprung mass of each vehicle suspension, and the acceleration of the unsprung mass; calculate the equivalent total stiffness of all elastic components of the corresponding suspension at the wheel end according to the stiffness of each elastic component, the leverage ratio of each elastic component relative to the wheel end, and the equivalent stiffness of the suspension bushings at the wheel end; calculate the equivalent load change of all elastic components of the corresponding suspension at the wheel end relative to the unloaded and ready-to-drive state in real time according to the equivalent total stiffness of all elastic components of the suspension at the wheel end and the dynamic displacement of the wheel relative to the target vehicle body; or, obtain the suspension load-displacement curve data through suspension K&C characteristic simulation calculation or by actual measurement of the vehicle, and look up the equivalent load change of all elastic components of the corresponding suspension at the wheel end relative to the unloaded and ready-to-drive state at the corresponding moment from the suspension load-displacement curve data according to the dynamic displacement of the wheel relative to the target vehicle body, where the suspension load-displacement curve data represents the equivalent load change of all elastic components at the wheel end corresponding to the dynamic displacement of the wheel relative to the target vehicle body in the unloaded and ready-to-drive state; perform differential calculation according to the dynamic displacement of the wheel relative to the target vehicle body to obtain the relative movement speed of the wheel relative to the target vehicle body; calculate the relative movement speed during shock absorber actuation according to the relative movement speed of the wheel relative to the target vehicle body and the leverage ratio of the shock absorber relative to the wheel; look up the F-V database of the shock absorber damping force - shock absorber actuation relative movement speed according to the relative movement speed during shock absorber actuation to obtain the real-time damping force of the shock absorber; calculate the equivalent dynamic action load of the shock absorber damping force at the wheel end according to the real-time damping force of the shock absorber and the leverage ratio of the shock absorber relative to the wheel; calculate the theoretical acceleration of the unsprung mass when the wheel is not in contact with the ground according to the equivalent load change of all elastic components of the suspension at the wheel end relative to the unloaded and ready-to-drive state, the equivalent dynamic action load of the shock absorber damping force at the wheel end, the gravity of the unsprung mass, and the unsprung mass of the suspension; calculate the acceleration difference between the measured acceleration of the unsprung mass and the theoretical acceleration of the unsprung mass when the wheel is not in contact with the ground.

[0203] In one embodiment, the determination module 20 is further configured to obtain, from the vehicle parameters, an upper limit value of the upward suspension travel of the target vehicle suspension relative to the unloaded curb state; read, from the vehicle signals, the measured dynamic displacement of the wheel relative to the vehicle body of the target vehicle; calculate a displacement difference between the measured dynamic displacement of the wheel relative to the vehicle body of the target vehicle and the upper limit value of the upward suspension travel of the target vehicle suspension relative to the unloaded curb state; take the differential of the dynamic displacement of the wheel relative to the vehicle body of the target vehicle to obtain the relative movement speed between the sprung mass and the vehicle body of the target vehicle; determine, based on the load-displacement characteristic data of the suspension, the maximum elastic force of the suspension corresponding to the suspension being compressed to the upper limit value of the wheel upward travel relative to the unloaded curb state, and the gravity received by the unsprung mass of the suspension, and calculate the unsprung acceleration corresponding to the suspension being compressed to the upper limit value of the upward travel; obtain the measured acceleration value of the unsprung mass from the vehicle signals; calculate an acceleration difference between the unsprung acceleration value corresponding to the suspension being compressed to the upper limit value of the upward travel and the measured acceleration of the unsprung mass; when the displacement difference between the measured dynamic displacement of the wheel relative to the vehicle body of the target vehicle and the upper limit value of the upward suspension travel of the target vehicle suspension relative to the unloaded curb state is less than or equal to a first preset displacement range, the relative movement speed between the sprung mass and the vehicle body is less than or equal to a first preset speed deviation range value, and the acceleration difference between the calculated unsprung acceleration value corresponding to the suspension being compressed to the upper limit value of the upward travel and the measured acceleration of the unsprung mass at the corresponding moment is less than or equal to a first preset acceleration difference range, it is determined that the wheel of the target vehicle is compressed to the limit position of the suspension travel and the wheel is in a non-grounded state.

[0204] In one embodiment, the determination module 20 is further configured to read the lower limit value of the downward jump stroke of the target vehicle suspension relative to the unloaded and ready-to-drive state suspension from the vehicle parameters; read the measured dynamic displacement of the wheel relative to the target vehicle body from the vehicle signals; calculate the displacement difference between the measured dynamic displacement of the wheel relative to the target vehicle body and the lower limit value of the downward jump stroke of the target vehicle suspension relative to the unloaded and ready-to-drive state; differentiate the dynamic displacement of the wheel relative to the target vehicle body to obtain the relative motion speed of the unsprung mass relative to the target vehicle body; determine the maximum elastic force of the suspension corresponding to when the suspension is stretched to the lower limit value of the wheel downward jump stroke and the gravity of the unsprung mass based on the load-displacement characteristic data of the suspension, and calculate the unsprung acceleration corresponding to when the suspension is stretched to the lower limit value of the downward jump stroke; obtain the measured acceleration value of the unsprung mass from the vehicle signals; calculate the acceleration difference between the calculated unsprung acceleration value corresponding to when the suspension is stretched to the lower limit value of the downward jump stroke and the measured acceleration of the unsprung mass; when the displacement difference between the measured dynamic displacement of the wheel relative to the target vehicle body and the lower limit value of the downward jump stroke of the target vehicle suspension relative to the unloaded and ready-to-drive state is less than or equal to the second preset displacement range, the relative motion speed of the unsprung mass is less than or equal to the second preset speed deviation range, and the acceleration difference between the calculated unsprung acceleration value corresponding to when the suspension is stretched to the lower limit value of the downward jump stroke and the measured acceleration of the unsprung mass at the corresponding moment is less than or equal to the second preset acceleration difference range, it is determined that the wheel of the target vehicle is stretched to the limit position of the suspension stroke and the wheel is in a non-grounded state.

[0205] It should be understood that the above is only an example and does not constitute any limitation to the technical solution of the present invention. In specific applications, those skilled in the art can set according to needs, and the present invention does not limit this.

[0206] It should be noted that the above-described work process is only illustrative and does not limit the protection scope of the present invention. In actual applications, those skilled in the art can select some or all of them according to actual needs to achieve the purpose of the solution of this embodiment, and this is not limited here.

[0207] In addition, for the technical details not described in detail in this embodiment, reference can be made to the vehicle tire transient vertical load calculation method provided in any embodiment of the present invention, which will not be elaborated here.

[0208] In addition, it should be noted that in this text, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article or system comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or system. Without further limitation, an element defined by the statement "comprising one..." does not exclude the existence of additional identical elements in the process, method, article or system comprising such element.

[0209] The serial numbers of the above embodiments of the present invention are for description only and do not represent the superiority or inferiority of the embodiments.

[0210] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-described embodiment methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present invention, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as Read Only Memory (ROM) / RAM, magnetic disk, optical disk) and includes several instructions for causing a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in various embodiments of the present invention.

[0211] The above are only the preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or equivalent process transformation made by using the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall equally be included in the patent protection scope of the present invention.

Claims

1. A method for calculating the transient vertical load of a vehicle tire, characterized in that, The transient vertical load calculation of the vehicle tire includes: Obtaining vehicle signals during the operation of the target vehicle and vehicle parameters of the target vehicle. The vehicle parameters include the wheel weight of the target vehicle in the unloaded and ready state, the stiffness of each elastic component, the lever ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushings converted to the wheel end, the characteristic data of the shock absorber damping force - shock absorber relative movement speed, the lever ratio of the shock absorber relative to the wheel, the unsprung mass of each suspension of the vehicle. The vehicle signals include the dynamic displacement of each wheel relative to the vehicle body of the target vehicle and the acceleration of the unsprung mass of each suspension; Detecting and calculating to identify whether the wheels of the target vehicle are grounded; When the wheels of the target vehicle are grounded, calculating the transient vertical load of the target vehicle tire at the corresponding moment in real time according to the vehicle signals and vehicle parameters.

2. The method for calculating the transient vertical load of a vehicle tire as described in claim 1, Characterized in that; The calculating the transient vertical load of the target vehicle tire at the corresponding moment in real time according to the vehicle signals and vehicle parameters includes: Extracting the dynamic displacement of the wheel relative to the vehicle body of the target vehicle and the acceleration of the unsprung mass from the vehicle signals; Calculating the transient vertical load of the target vehicle tire at the corresponding moment according to the wheel weight of the target vehicle in the unloaded and ready state, the stiffness of each elastic component, the lever ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushings at the wheel end, the characteristic data of the shock absorber damping force - shock absorber relative movement speed, the lever ratio of the shock absorber relative to the wheel, the dynamic displacement of the wheel relative to the vehicle body of the target vehicle, the unsprung mass of each suspension of the vehicle, and the acceleration of the unsprung mass.

3. The method for calculating the transient vertical load of a vehicle tire according to claim 2, characterized in that, The calculating the transient vertical load of the target vehicle tire at the corresponding moment according to the wheel weight of the target vehicle in the unloaded and ready state, the stiffness of each elastic component, the lever ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushings at the wheel end, the characteristic data of the shock absorber damping force - shock absorber relative movement speed, the lever ratio of the shock absorber relative to the wheel, the dynamic displacement of the wheel relative to the vehicle body of the target vehicle, the unsprung mass of each suspension of the vehicle, and the acceleration of the unsprung mass, etc. includes: Calculating the equivalent total stiffness of all elastic components at the wheel end of the corresponding suspension according to the stiffness of each elastic component, the lever ratio of each elastic component relative to the wheel, and the equivalent stiffness of the suspension bushings at the wheel end; Calculating the equivalent load change amount of all elastic components of the corresponding suspension relative to the unloaded and ready state at the wheel end at the corresponding moment in real time according to the equivalent total stiffness of all elastic components of the suspension at the wheel end and the dynamic displacement of the wheel relative to the vehicle body of the target vehicle; Or, The suspension load-displacement curve data is obtained through suspension K&C characteristic simulation calculation or measured output of the vehicle. According to the dynamic displacement of the wheel relative to the target vehicle body, the equivalent load change amount of all elastic components of the suspension at the corresponding moment relative to the no-load ready state at the wheel end is retrieved from the suspension load-displacement curve data. The suspension load-displacement curve data represents the equivalent load change amount of all elastic components at the wheel end corresponding to the dynamic displacement of the wheel relative to the target vehicle body in the no-load ready state; Differential calculation is performed according to the dynamic displacement of the wheel relative to the target vehicle body to obtain the relative movement speed of the wheel relative to the target vehicle body; According to the relative movement speed of the wheel relative to the target vehicle body and the lever ratio of the shock absorber relative to the wheel, the relative movement speed during the actuation of the shock absorber is calculated; According to the relative movement speed during the actuation of the shock absorber, the shock absorber damping force - shock absorber actuation relative speed database is retrieved to obtain the real-time damping force of the shock absorber; According to the real-time damping force of the shock absorber and the lever ratio of the shock absorber relative to the wheel, the equivalent dynamic action load of the shock absorber damping force at the wheel end is calculated; According to the unsprung mass of each suspension of the vehicle and the acceleration of the unsprung mass, the dynamic load of the unsprung mass is calculated; According to the wheel weight of the target vehicle in the no-load ready state, the equivalent load change amount of all elastic components of the suspension relative to the no-load ready state at the wheel end, the equivalent dynamic action load of the shock absorber at the wheel end, and the dynamic load of the unsprung mass, the transient vertical load of the tire of the target vehicle at the corresponding moment is calculated in real time.

4. The vehicle tire transient vertical load calculation method according to any one of claims 1 to 3, characterized in that, When any of the following conditions is met, it is determined that the wheel of the target vehicle is not in contact with the ground: The acceleration difference between the measured unsprung mass acceleration of the target vehicle and the unsprung mass acceleration calculated using the vehicle wheel contact identification model is within the preset deviation range; The wheel of the target vehicle is compressed to the upper limit position of the suspension stroke and is in a suspended state off the ground; The wheel of the target vehicle is stretched to the lower limit position of the suspension stroke and is in a suspended state off the ground.

5. The vehicle tire transient vertical load calculation method according to claim 4, wherein The method for calculating the transient vertical load of the vehicle tire includes: Obtain the stiffness of each elastic component of the target vehicle suspension, the lever ratio of each elastic component relative to the wheel, the total stiffness of the suspension link bushings at the wheel end, the characteristic data of the shock absorber damping force - shock absorber relative movement speed, and the lever ratio of the shock absorber relative to the wheel from the vehicle parameters; Obtain the dynamic displacement of the wheel relative to the target vehicle body, the unsprung mass of each suspension of the vehicle, and the acceleration of the unsprung mass from the vehicle signals; According to the stiffness of each elastic component, the lever ratio of each elastic component relative to the wheel end, and the equivalent stiffness of the suspension bushings at the wheel end, calculate the equivalent total stiffness of all elastic components of the corresponding suspension at the wheel end; According to the equivalent total stiffness of all elastic components of the suspension at the wheel end and the dynamic displacement of the wheel relative to the target vehicle body, calculate the equivalent load change amount of all elastic components of the suspension relative to the no-load ready state at the wheel end at the corresponding moment in real time; Or, The suspension load-displacement curve data is obtained through simulation calculation of the suspension K&C characteristics or measured output of the vehicle. According to the dynamic displacement of the wheel relative to the target vehicle body, the equivalent load change amount of all elastic components of the suspension at the corresponding moment relative to the unloaded and ready state at the wheel end is retrieved from the suspension load-displacement curve data. The suspension load-displacement curve data represents the equivalent load change amount of all elastic components at the wheel end corresponding to the dynamic displacement of the wheel relative to the target vehicle body in the unloaded and ready state; Differential calculation is performed based on the dynamic displacement of the wheel relative to the target vehicle body to obtain the relative motion speed of the wheel relative to the target vehicle body; 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 relative motion speed during the actuation of the shock absorber is calculated; The real-time damping force of the shock absorber is obtained by retrieving the shock absorber damping force - shock absorber actuation relative motion speed database based on the relative motion speed during the actuation of the shock absorber; Based on the real-time damping force of the shock absorber and the lever ratio of the shock absorber relative to the wheel, the equivalent dynamic action load of the shock absorber damping force at the wheel end is calculated; Based on the equivalent load change amount of all elastic components of the suspension relative to the unloaded and ready state at the wheel end, the equivalent dynamic action load of the shock absorber damping force at the wheel end, the gravity of the unsprung mass, and the unsprung mass of the suspension, the theoretical acceleration of the unsprung mass when the wheel is not in contact with the ground is calculated; The acceleration difference between the measured acceleration of the unsprung mass and the theoretical acceleration of the unsprung mass when the wheel is not in contact with the ground is calculated; The acceleration difference between the measured acceleration of the unsprung mass of the target vehicle and the acceleration of the unsprung mass calculated using the vehicle wheel contact identification analysis model is compared with the preset acceleration deviation range. When it is within the preset acceleration deviation range, it indicates that the wheel conforms to the characteristic of leaving the ground, and it is determined that the wheel is not in contact with the ground.

6. The vehicle tire transient vertical load calculation method according to claim 4, characterized in that, The method for calculating the transient vertical load of the vehicle tire further includes: Obtaining the upper limit value of the upward suspension travel of the target vehicle suspension relative to the unloaded and ready state from the vehicle parameters; Reading the measured dynamic displacement of the wheel relative to the target vehicle body from the vehicle signal; Calculating the displacement difference between the measured dynamic displacement of the wheel relative to the target vehicle body and the upper limit value of the upward suspension travel of the target vehicle suspension relative to the unloaded and ready state; Differentiating the dynamic displacement of the wheel relative to the target vehicle body to obtain the relative motion speed between the sprung masses of the wheel relative to the target vehicle body; Based on the load-displacement characteristic data of the suspension, determining the maximum elastic force of the suspension corresponding to the compression of the suspension from the unloaded and ready state to the upper limit value of the wheel upward travel, and the gravity of the unsprung mass of the suspension, and calculating the unsprung acceleration corresponding to the suspension being compressed to the upper limit value of the upward travel; Obtaining the measured acceleration value of the unsprung mass from the vehicle signal; Calculating the acceleration difference between the unsprung acceleration value corresponding to the suspension being compressed to the upper limit value of the upward travel and the measured acceleration of the unsprung mass; When the displacement difference between the measured dynamic displacement of the wheel relative to the body of the target vehicle and the upper limit value of the upward jump stroke of the target vehicle suspension relative to the unloaded and ready state is less than or equal to the first preset displacement range, the relative movement speed between the springs is less than or equal to the first preset speed range value, and the acceleration difference between the calculated value of the acceleration of the unsprung mass corresponding to when the suspension is compressed to the upper limit value of the upward jump stroke and the measured acceleration of the unsprung mass at the corresponding moment is less than or equal to the first preset acceleration difference range, it is determined that the wheel of the target vehicle is compressed to the limit position of the suspension stroke and the wheel is in a state of being off the ground and suspended.

7. The method for calculating the transient vertical load of a vehicle tire according to claim 4, wherein The method for calculating the transient vertical load of the vehicle tire further includes: Obtaining the lower limit value of the downward jump stroke of the target vehicle suspension relative to the unloaded and ready state suspension from the vehicle parameters; Reading the measured dynamic displacement of the wheel relative to the body of the target vehicle from the vehicle signals; Calculating the displacement difference between the measured dynamic displacement of the wheel relative to the body of the target vehicle and the lower limit value of the downward jump stroke of the target vehicle suspension relative to the unloaded and ready state; Differentiating the dynamic displacement of the wheel relative to the body of the target vehicle to obtain the relative movement speed between the springs of the wheel relative to the body of the target vehicle; Based on the load-displacement characteristic data of the suspension, determining the maximum elastic force of the suspension corresponding to when the suspension is stretched to the lower limit value of the downward jump stroke of the wheel relative to the unloaded and ready state, and the gravity received by the unsprung mass of the suspension, and calculating the unsprung acceleration corresponding to when the suspension is stretched to the lower limit value of the downward jump stroke; Obtaining the measured acceleration value of the unsprung mass from the vehicle signals; Calculating the acceleration difference between the calculated value of the unsprung acceleration corresponding to when the suspension is stretched to the lower limit value of the downward jump stroke and the measured acceleration of the unsprung mass; When the displacement difference between the measured dynamic displacement of the wheel relative to the body of the target vehicle and the lower limit value of the downward jump stroke of the target vehicle suspension relative to the unloaded and ready state is less than or equal to the second preset displacement range, the relative movement speed between the springs is less than or equal to the second preset speed range, and the acceleration difference between the calculated value of the unsprung acceleration corresponding to when the suspension is stretched to the lower limit value of the downward jump stroke and the measured acceleration of the unsprung mass at the corresponding moment is less than or equal to the second preset acceleration difference range, it is determined that the wheel of the target vehicle is stretched to the limit position of the suspension stroke and the wheel is in a state of being off the ground and suspended.

8. A transient vertical load calculation device for vehicle tires, characterized in that, The device for calculating the transient vertical load of the vehicle tire includes: An acquisition module, configured to acquire vehicle signals during the operation of the target vehicle and vehicle parameters of the target vehicle, where the vehicle parameters include the wheel weight of the target vehicle in the 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 bushings converted to the wheel end, the characteristic data of the damping force of the shock absorber - the relative movement speed of the shock absorber, the leverage ratio of the shock absorber relative to the wheel, and the unsprung mass of each suspension of the vehicle, and the vehicle signals include the dynamic displacement of each wheel relative to the body of the target vehicle and the acceleration of the unsprung mass of each suspension; A judgment module, configured to detect and calculate and identify whether the wheel of the target vehicle is grounded; An operation module, configured to calculate the transient vertical load of the target vehicle's tire at the corresponding moment in real time according to the vehicle signal and vehicle parameters when the wheel of the target vehicle is grounded.

9. A transient vertical load calculation device for vehicle tires, characterized in that, The vehicle tire transient vertical load calculation device includes: a memory, a processor, and a vehicle tire transient vertical load calculation program stored on the memory and executable on the processor, where the vehicle tire transient vertical load calculation program is configured to implement the vehicle tire transient vertical load calculation method according to any one of claims 1 to 7.

10. A storage medium, characterized in that, A vehicle tire transient vertical load calculation program is stored on the storage medium, and when the vehicle tire transient vertical load calculation program is executed by a processor, it implements the vehicle tire transient vertical load calculation method according to any one of claims 1 to 7.

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