A method and device for online evaluation of the service life of vehicle parts

Abstract

The present invention provides a method and device for online evaluating the service life of vehicle components. The method determines the real-time loads of various chassis components in the vehicle's suspension system according to the six-component forces of the wheel center obtained during the vehicle operation; determines the deformation states of the various chassis components according to the six-component forces of the wheel center, the real-time loads of the various chassis components, and the strength-bearing capacity loads; determines the remaining service lives of the various chassis components based on the deformation states, real-time loads, and pseudo-damage bases of the various chassis components; and issues corresponding chassis component status notifications according to the deformation states and remaining service lives of the various chassis components, in combination with the six-component forces of the wheel center and a preset driver impact feeling threshold, thereby achieving accurate hierarchical quantification evaluation of the deformation states and remaining service lives of the vehicle chassis components, and performing real-time status notifications, which can avoid misdiagnosis and missed diagnosis of the chassis component status during driving and ensure driving safety.

Description

Technical Field

[0001] This application relates to the technical field of vehicle engineering, and particularly to a method and device for online assessment of the lifespan of vehicle components. Background Art

[0002] As load-bearing components, the lifespan of vehicle chassis components directly affects the safety performance of the vehicle. During the vehicle R & D stage, rigorous analysis and verification of chassis components are usually carried out through means such as data analysis, simulation, real vehicle testing, and user research.

[0003] The actual usage environment of vehicles is complex and changeable, including various factors such as user driving habits and road conditions. Some extreme conditions will have a significant impact on the lifespan of chassis components, thereby affecting driving safety. For example, sudden potholes, sharp turns, or emergency braking on the road surface. These conditions often bring a large impact to the vehicle chassis components.

[0004] In the prior art, drivers often rely only on their subjective feelings to judge the severity of the impact and cannot quantitatively evaluate the specific damage caused by these impacts to chassis components. However, this kind of judgment often has errors. When a driver subjectively feels a large impact, if the actual damage does not exceed the bearing range of the chassis components, then frequently going to the maintenance center for inspection not only consumes a large amount of manpower and material resources, but also may cause unnecessary panic. On the contrary, if the actual impact is large but the driver fails to notice it in time, the damage to the chassis components may gradually accumulate, eventually leading to serious safety problems such as vehicle out of control and component fracture, posing a serious threat to the lives and safety of drivers and passengers. Summary of the Invention

[0005] This application provides a method and device for online assessment of the lifespan of vehicle components, which realizes accurate quantitative assessment of the deformation state and remaining lifespan of vehicle chassis components and conducts status notification, and can avoid misdiagnosis and missed diagnosis of component status during driving, ensuring driving safety.

[0006] In a first aspect, an embodiment of this application provides a method for online assessment of the lifespan of vehicle components. The method for online assessment of the lifespan of vehicle components includes:

[0007] Obtain the six-component forces of the wheel center of the vehicle during vehicle operation, and determine the real-time loads of each chassis component in the suspension system of the vehicle according to the six-component forces of the wheel center;

[0008] Determine the deformation state of each chassis component according to the six-component forces of the wheel center, the real-time loads of each chassis component, and the strength bearing capacity loads of each chassis component;

[0009] Based on the deformation states of each chassis component, determine the remaining life of each chassis component according to the real-time load of each chassis component and the pseudo-damage base number of each chassis component;

[0010] According to the deformation states and remaining lives of each chassis component, and in combination with the six-component wheel center force and a preset driver impact feeling threshold, issue corresponding chassis component status notifications.

[0011] Combined with the first aspect, in one implementation manner, obtaining the six-component wheel center force of the vehicle during vehicle operation includes:

[0012] Calculate the six-component wheel center force of the vehicle according to the unsprung acceleration, sprung acceleration, and relative compression displacement between the unsprung and sprung parts of the vehicle collected during the vehicle operation.

[0013] Combined with the first aspect, in one implementation manner, the calculating the six-component wheel center force of the vehicle according to the unsprung acceleration, sprung acceleration, and relative compression displacement between the unsprung and sprung parts of the vehicle collected during the vehicle operation includes:

[0014] Calculate the normal wheel center force of the vehicle according to the vertical stiffness of the suspension system, the relative compression displacement between the unsprung and sprung parts, the vertical damping coefficient of the suspension system, the relative compression speed between the unsprung and sprung parts, the unsprung mass of the vehicle, and the unsprung vertical acceleration;

[0015] Calculate the wheel center braking torque according to the braking hydraulic pipeline pressure of the vehicle, the piston area of the brake wheel cylinder, and the radius from the piston of the brake wheel cylinder to the wheel axle;

[0016] When the unsprung vertical acceleration is greater than or equal to a preset first acceleration threshold, or the sprung vertical acceleration is greater than or equal to a preset second acceleration threshold, calculate the longitudinal wheel center force of the vehicle according to the unsprung mass, the unsprung longitudinal acceleration, the longitudinal stiffness of the suspension system, and the longitudinal displacement of the unsprung relative to the sprung;

[0017] When the unsprung vertical acceleration is less than the preset first acceleration threshold and the sprung vertical acceleration is less than the preset second acceleration threshold, if the vehicle is in an accelerating state, determine the vehicle's longitudinal torque according to the sprung longitudinal acceleration and obtain the longitudinal wheel center force of the vehicle by distributing the vehicle's longitudinal torque. If the vehicle is in a braking state, calculate the longitudinal wheel center force of the vehicle according to the wheel center braking torque and the rolling radius of the vehicle's wheels;

[0018] Calculate the lateral wheel center force of the vehicle according to the total mass of the front axle of the vehicle and the lateral acceleration of the front axle;

[0019] Calculate the wheel center overturning moment based on the wheel center lateral force, the wheel rolling radius, and the distance between the lateral force application point of the wheel and the wheel center.

[0020] Calculate the wheel center self-aligning moment based on the axial force of the steering tie rod of the vehicle and the acting distance between the ball joint of the steering tie rod and the kingpin.

[0021] Combined with the first aspect, in one embodiment, before determining the deformation state of each chassis component according to the six-component force of the wheel center, the real-time load of each chassis component, and the strength-bearing capacity load of each chassis component, it further includes:

[0022] Obtain the strength-bearing capacity loads in each direction of each chassis component in the bench strength test, where the strength-bearing capacity loads include the yield point load, the equivalent plastic strain PEEQ2% point load, and the large deformation point load or the fracture point load;

[0023] For each load value of each chassis component in each direction after the yield point load and before the large deformation point load or the fracture point load, construct a corresponding mapping relationship in combination with the corresponding equivalent plastic strain;

[0024] Convert the strength-bearing capacity loads in each direction of each chassis component into corresponding converted wheel center loads respectively, and obtain the yield point converted wheel center loads, the PEEQ2% point converted wheel center loads, and the large deformation point converted wheel center loads or the fracture point converted wheel center loads in each direction of each chassis component.

[0025] Combined with the first aspect, in one embodiment, determining the deformation state of each chassis component according to the six-component force of the wheel center, the real-time load of each chassis component, and the strength-bearing capacity load of each chassis component includes:

[0026] For any chassis component, when the six-component force of the wheel center is less than or equal to the yield point converted wheel center loads in each direction of the chassis component, determine that the deformation state of the chassis component is that no equivalent plastic strain has occurred;

[0027] When the six-component force of the wheel center is greater than the yield point converted wheel center load in any direction of the chassis component and less than or equal to the PEEQ2% point converted wheel center loads in each direction, determine that the chassis component has undergone a first-level equivalent plastic strain, and find the maximum equivalent plastic strain of the chassis component by looking up the mapping relationship according to the real-time load of the chassis component;

[0028] When the six-component wheel center force is greater than the wheel center load converted from the PEEQ 2% point in any direction of the chassis component and less than the wheel center load converted from the large deformation point or the fracture point in each direction, it is determined that the chassis component has undergone secondary equivalent plastic strain, and the mapping relationship is searched according to the real-time load of the chassis component to obtain the maximum equivalent plastic strain of the chassis component;

[0029] When the six-component wheel center force is greater than or equal to the wheel center load converted from the large deformation point or the fracture point in any direction of the chassis component, it is determined that the chassis component has large deformation or fracture.

[0030] Combined with the first aspect, in an implementation manner, before determining the remaining life of each chassis component according to the deformation state of each chassis component, the real-time load of each chassis component, and the pseudo-damage base number of each chassis component, it further includes:

[0031] When the vehicle is undergoing a proving ground durability test, the Q-fold pseudo-damage of the proving ground durability load in each direction of each chassis component is used as the pseudo-damage base number in each direction of the corresponding chassis component.

[0032] Combined with the first aspect, in an implementation manner, determining the remaining life of each chassis component according to the deformation state of each chassis component, the real-time load of each chassis component, and the pseudo-damage base number of each chassis component includes:

[0033] For any chassis component, when the chassis component has not undergone equivalent plastic strain, the cumulative pseudo-damage in each direction of the chassis component is calculated in real time through the rain flow counting algorithm according to the six-component wheel center force, and the cumulative pseudo-damage in each direction of the chassis component is divided by the pseudo-damage base number in the corresponding direction to obtain the service life in each direction, and the remaining life of the chassis component is determined according to the maximum service life;

[0034] When the deformation state of the chassis component is primary equivalent plastic strain or secondary equivalent plastic strain, the impact load damage of the chassis component is calculated according to the material type and the maximum equivalent plastic strain of the component, and the damage life and the remaining life of the chassis component are obtained according to the impact load damage and the pseudo-damage base number in the corresponding direction;

[0035] When the deformation state of the chassis component is large deformation or fracture, it is determined that the remaining life of the chassis component is zero.

[0036] Combined with the first aspect, in an implementation manner, issuing a corresponding chassis component status notification according to the deformation state and the remaining life of each chassis component, in combination with the six-component wheel center force and a preset driver impact feeling threshold, includes:

[0037] When all chassis components in the suspension system have not undergone plastic strain, if the longitudinal wheel center force is greater than the driver's impact longitudinal perception threshold, the lateral wheel center force is greater than the driver's impact lateral perception threshold, or the normal wheel center force is greater than the driver's impact normal perception threshold, a first status notification indicating no damage to the chassis components is issued; otherwise, no status notification is issued.

[0038] When there is a chassis component with a first-level equivalent plastic strain, a second status notification indicating the occurrence of a first-level equivalent plastic strain in the chassis component is issued, and the chassis component with the first-level equivalent plastic strain and its remaining life are synchronously displayed.

[0039] When there is a chassis component with a second-level equivalent plastic strain, a third status notification indicating that careful driving is required due to the occurrence of a second-level equivalent plastic strain in the chassis component is issued, and the chassis component with the second-level equivalent plastic strain and its remaining life are synchronously displayed.

[0040] When there is a large deformation or fracture of a chassis component, a fourth status notification indicating that safe driving is impossible due to the large deformation or fracture of the chassis component is issued, the chassis component with the large deformation or fracture is synchronously displayed, and the status of the chassis component is sent to the after-sales end.

[0041] In combination with the first aspect, in an implementation manner:

[0042] The driver's impact longitudinal perception threshold is M times the maximum load-bearing wheel load of the vehicle.

[0043] The driver's impact lateral perception threshold is N times the maximum load-bearing wheel load of the vehicle.

[0044] The driver's impact normal perception threshold is R times the maximum load-bearing wheel load of the vehicle.

[0045] In a second aspect, an embodiment of the present application provides a device for online evaluation of the life of vehicle components. The device for online evaluation of the life of vehicle components includes:

[0046] An acquisition module, which is used to acquire the six-component forces of the wheel center of the vehicle during the operation of the vehicle and determine the real-time loads of each chassis component in the suspension system of the vehicle according to the six-component forces of the wheel center.

[0047] A first determination module, which is used to determine the deformation state of each chassis component according to the six-component forces of the wheel center, the real-time loads of each chassis component, and the strength-bearing capacity loads of each chassis component.

[0048] A second determination module, configured to determine the remaining life of each chassis component based on the deformation state of each chassis component, according to the real-time load of each chassis component and the pseudo-damage base number of each chassis component;

[0049] A notification module, configured to issue a corresponding chassis component status notification according to the deformation state and remaining life of each chassis component, in combination with the six-component wheel center force and a preset driver impact feeling threshold.

[0050] The beneficial effects brought by the technical solution provided by the embodiments of the present application include:

[0051] By obtaining the six-component wheel center force of the vehicle during the vehicle operation, and determining the real-time load of each chassis component in the suspension system of the vehicle according to the six-component wheel center force; determining the deformation state of each chassis component according to the six-component wheel center force, the real-time load of each chassis component and the strength bearing capacity load of each chassis component; determining the remaining life of each chassis component based on the deformation state of each chassis component, according to the real-time load of each chassis component and the pseudo-damage base number of each chassis component; and issuing a corresponding chassis component status notification according to the deformation state and remaining life of each chassis component, in combination with the six-component wheel center force and a preset driver impact feeling threshold, it realizes an accurate hierarchical quantification evaluation of the deformation state and remaining life of vehicle chassis components, and performs real-time status notification, which can avoid misdiagnosis and missed diagnosis of the chassis component status during driving, ensure driving safety, and at the same time reduce the panic psychology of the driver when the vehicle passes through complex road conditions. Description of the Drawings

[0052] Figure 1 It is a schematic flowchart of an embodiment of the method for online evaluating the life of vehicle components in the present application;

[0053] Figure 2 It is a schematic diagram of the strength bearing capacity load distribution of chassis components;

[0054] Figure 3 It is a schematic diagram of the pseudo-damage distribution of the durability bearing capacity of chassis components;

[0055] Figure 4 It is a schematic diagram of the functional modules of an embodiment of the device for online evaluating the life of vehicle components in the present application. Detailed Embodiments

[0056] To enable those skilled in the art to better understand the solution of this application, the following will clearly and completely describe the technical solution in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

[0057] To make the purpose, technical solution and advantages of this application clearer, the following will further describe the embodiments of this application in detail with reference to the accompanying drawings.

[0058] In a first aspect, an embodiment of this application provides a method for online evaluating the life of vehicle components.

[0059] In one embodiment, referring to Figure 1 , Figure 1 is a schematic flowchart of the first embodiment of the method for online evaluating the life of vehicle components in this application. As Figure 1 shown, the method for online evaluating the life of vehicle components includes:

[0060] Step S101: Obtain the six-component forces of the wheel center of the vehicle during the running of the vehicle, and determine the real-time loads of each chassis component in the suspension system of the vehicle according to the six-component forces of the wheel center.

[0061] Step S102: Determine the deformation state of each chassis component according to the six-component forces of the wheel center, the real-time loads of each chassis component, and the strength-bearing capacity loads of each chassis component.

[0062] Step S103: Based on the deformation state of each chassis component, determine the remaining life of each chassis component according to the real-time load of each chassis component and the pseudo-damage base number of each chassis component.

[0063] Step S104: According to the deformation state and remaining life of each chassis component, and in combination with the six-component forces of the wheel center and a preset driver impact feeling threshold, send a corresponding chassis component status notification.

[0064] It should be noted that in this embodiment, the deformation state and remaining life of each chassis component are calculated in real time by quantifying the force condition of the wheel center of the vehicle obtained online, and the status of the chassis component is notified in real time, which can help the driver timely know the accurate status of the vehicle component, avoid misdiagnosis and missed diagnosis of the chassis component status during driving, ensure driving safety, and at the same time reduce the panic psychology of the driver when the vehicle passes through complex road conditions and the driver feels a large impact subjectively.

[0065] The method for online evaluating the lifespan of vehicle components in this application can be applied to different chassis components of different types of suspension systems. Taking the front double-wishbone suspension as an example, its chassis components include steering knuckles, lower control arms, upper control arms, and subframes.

[0066] It should be noted that the strength-bearing capacity loads of each chassis component and the pseudo-damage base numbers of each chassis component are pre-obtained and pre-placed in the operation module of the vehicle. The methods for obtaining the strength-bearing capacity loads and pseudo-damage base numbers of each component are described below.

[0067] In one embodiment, obtaining the strength-bearing capacity loads of each chassis component specifically includes the following steps:

[0068] Step S201: Obtain the strength-bearing capacity loads of each chassis component in each direction during the bench strength test, where the strength-bearing capacity loads include the yield point load, the equivalent plastic strain PEEQ2% point load, and the large deformation point load or the fracture point load.

[0069] Exemplarily, bench tests can be performed on each chassis component, or CAE simulations can be performed on the vehicle, and the force-displacement curves of each chassis component loaded to failure in each force direction can be obtained. The abscissa of the curve is the deformation amount of the chassis component, and the ordinate is the load applied to the chassis component. The strength-bearing capacity loads of the corresponding chassis component in the corresponding direction can be obtained from the force-displacement curve. As Figure 2 shown, each direction of each chassis component has corresponding yield point loads, PEEQ = 2% point loads, and large deformation point loads or fracture point loads.

[0070] Taking the following chassis component control arm as an example, the yield point loads, PEEQ = 2% point loads, and large deformation point loads or fracture point loads in the X direction, Y direction, and Z direction of the ball joint of the lower control arm are shown in Table 1:

[0071] Table 1 Strength-bearing capacity loads of each direction of the lower control arm

[0072]

[0073] Step S202: For each load value of each chassis component in each direction after the yield point load and before the large deformation point load or the fracture point load, construct a corresponding mapping relationship in combination with the corresponding equivalent plastic strain.

[0074] It should be noted that before the yield point load, the deformation of the chassis components is elastic deformation, and the original shape can be restored after the load applied to them is cancelled. When the chassis components exceed the yield point, before fracture or large deformation occurs, any load value can correspond to an equivalent plastic strain. Therefore, a mapping relationship between each load value after the yield point load and before the large deformation point load or fracture point load and the corresponding equivalent plastic strain can be constructed.

[0075] Step S203: Through the pre-established vehicle's overall vehicle dynamics multi-body model, according to the corresponding conversion coefficient, the strength bearing capacity loads of each chassis component in each direction can be respectively converted into the corresponding converted wheel center loads, so as to obtain the yield point converted wheel center loads and PEEQ2% point converted wheel center loads of each chassis component in each direction, as well as the large deformation point converted wheel center loads or fracture point converted wheel center loads. The conversion method when converting the strength bearing capacity load into the wheel center load has been recorded in the relevant public technologies and will not be elaborated here.

[0076] Furthermore, obtaining the strength bearing capacity loads of each chassis component specifically includes the following steps:

[0077] When the vehicle undergoes a test field durability test, the Q-fold test field durability load pseudo-damage of each chassis component in each direction is used as the pseudo-damage base number of the corresponding chassis component in each direction.

[0078] Explanatorily, the relative relationship between the bearing capacity pseudo-damage of the chassis component and the test field durability load pseudo-damage is as Figure 3 shown. Usually, the lifespan of the chassis component is at least more than 4 times that of the test field durability test lifespan. After statistically analyzing the pseudo-damage of the test field durability wheel center load, due to the inconsistent environments (high temperature, corrosion) when users use the vehicle, for the convenience of calculation, in this embodiment, the lifespan of each component is normalized to define the test field 1-fold lifespan, and the load reaching this point is used as the point that users must check to ensure driving safety.

[0079] Exemplarily, in this embodiment, the 1-fold test field durability load pseudo-damage of each chassis component in each direction is used as the pseudo-damage base number of the corresponding chassis component in each direction. The pseudo-damage base numbers of each direction of the lower control arm are shown in Table 2:

[0080] Table 2 Pseudo-damage base numbers of each direction of the lower control arm

[0081]

[0082] As a preferred implementation manner, the driver's impact perception threshold is also pre-set in the vehicle's operation module in advance. The driver's impact perception threshold includes the driver's longitudinal impact perception threshold, the driver's lateral impact perception threshold, and the driver's normal impact perception threshold.

[0083] The longitudinal impact perception threshold of the driver is M times the maximum load-bearing wheel load of the vehicle; the lateral impact perception threshold of the driver is N times the maximum load-bearing wheel load of the vehicle; the normal impact perception threshold of the driver is R times the maximum load-bearing wheel load of the vehicle.

[0084] Exemplarily, in this embodiment, the longitudinal impact perception threshold of the driver is 2 times the maximum load-bearing wheel load of the vehicle, the lateral impact perception threshold of the driver is 1.5 times the maximum load-bearing wheel load of the vehicle; the normal impact perception threshold of the driver is 2 times the maximum load-bearing wheel load of the vehicle. The driver impact perception threshold here is used to simulate the threshold point at which, in the subjective perception of the driver, when passing over a pothole, it is considered that "the vehicle has been damaged and needs to be parked for inspection or after-sales inspection".

[0085] After the strength-bearing capacity load, pseudo-damage base number of the chassis components and the driver impact perception threshold are preset in the vehicle operation module, the online evaluation of the service life of the vehicle chassis components can be carried out.

[0086] It should be noted that when obtaining the six-wheel center forces of the vehicle during the vehicle operation in step S101, since the user's vehicle cannot use various special six-wheel center force sensors like the test vehicle to collect and obtain the six-wheel center forces, in this embodiment, a series of vehicle-mounted sensors are used to collect some physical quantities in real time and then estimate and calculate the wheel center forces through conversion.

[0087] In one embodiment, according to the under-spring acceleration, over-spring acceleration and relative compression displacement between the over-spring and under-spring of the vehicle collected during the vehicle operation, the six-wheel center forces of the vehicle are calculated.

[0088] Among them, the six-wheel center forces include: the longitudinal wheel center force Fx, the lateral wheel center force Fy, the normal wheel center force Fz, the wheel center overturning moment Mx, the wheel center braking moment My and the wheel center self-aligning moment Mz. The over-spring part of the vehicle refers to the part supported by the suspension system, including the body, frame, power system, etc., and the under-spring part refers to the part not supported by the suspension system, including the suspension, wheels and braking system, etc.

[0089] In this embodiment, the collected under-spring acceleration includes the under-spring longitudinal (X-direction) acceleration ax1, the under-spring lateral (Y-direction) acceleration ay1 and the under-spring vertical (Z-direction) acceleration az1; the over-spring acceleration includes the over-spring longitudinal acceleration ax2, the over-spring lateral acceleration ay2 and the over-spring vertical acceleration az2. The relative compression displacement between the over-spring and under-spring is the relative compression displacement between the over-spring and under-spring measured in real time by a height sensor.

[0090] Specifically, based on the vertical stiffness of the suspension system, the relative compression displacement between the sprung and unsprung masses, the vertical damping coefficient of the suspension system, the relative compression velocity between the sprung and unsprung masses, the unsprung mass of the vehicle, and the unsprung vertical acceleration, the normal force at the wheel center of the vehicle is calculated as follows:

[0091] Fz = Kz * h + Dz * h′ + M1 * az1

[0092] In the formula, Fz is the normal force at the wheel center, Kz is the vertical stiffness of the suspension system, h is the relative compression displacement between the sprung and unsprung masses, Dz is the vertical damping coefficient of the suspension system, h′ is the derivative of the relative compression displacement h between the sprung and unsprung masses with respect to time, that is, the relative compression velocity between the sprung and unsprung masses, M1 is the unsprung mass of the vehicle, and az1 is the unsprung vertical acceleration.

[0093] Among them, the unsprung mass refers to the mass not supported by the suspension system, usually including the wheels, tires, braking system (such as brake discs, brake calipers), and suspension components (such as springs, shock absorbers, linkages, etc.). The vertical stiffness Kz of the suspension system needs to be obtained in advance through bench tests or simulations. It should be noted that it is not only the stiffness in the linear section. In this case, it is defined that the force needs to be continuously applied until the entire suspension system fails, and the force-displacement curve at this time is recorded as the stiffness curve. Usually, the greater the force, the more obvious the non-linearity.

[0094] Furthermore, the braking hydraulic line pressure of the vehicle is collected, and based on the braking hydraulic line pressure of the vehicle, the piston area of the brake wheel cylinder, and the radius from the piston of the brake wheel cylinder to the wheel axle, the braking torque at the wheel center is calculated as follows:

[0095] My = 2 * P * s * r

[0096] In the formula, P is the braking hydraulic line pressure of the vehicle, s is the piston area of the brake wheel cylinder, and r is the radius from the piston of the brake wheel cylinder to the wheel axle.

[0097] Explanatorily, when the vehicle brakes, the braking torque is applied to the suspension, and the force on the suspension needs to be added with the braking torque again. Since the reaction force of the driving torque is transmitted from the wheel - drive shaft - motor - body, the driving torque is ignored during the suspension calculation. That is, only during braking, regardless of whether there is an impact on the road surface, the torque in the My direction transmitted to the suspension is only provided by the braking force My.

[0098] Furthermore, when the unsprung vertical acceleration is greater than or equal to a preset first acceleration threshold, or the sprung vertical acceleration is greater than or equal to a preset second acceleration threshold, based on the unsprung mass, the unsprung longitudinal acceleration, the longitudinal stiffness of the suspension system, and the longitudinal displacement of the unsprung relative to the sprung, the longitudinal force at the wheel center of the vehicle is calculated.

[0099] Exemplarily, the first acceleration threshold in this embodiment is 5g, and the acceleration threshold is 0.5g, where g is the acceleration due to gravity. That is, when az1 ≥ 5g or az2 ≥ 0.5g, according to the unsprung mass, the unsprung longitudinal acceleration, the longitudinal stiffness of the suspension system, and the longitudinal displacement of the unsprung relative to the sprung, the longitudinal wheel center force of the vehicle is calculated as follows:

[0100] Fx = M1 * ax1 + Kx * Disp_X

[0101] In the formula, Fx is the longitudinal wheel center force, M1 is the unsprung mass, ax1 is the unsprung longitudinal acceleration, Kx is the longitudinal stiffness of the suspension system, and Disp_X is the longitudinal displacement of the unsprung relative to the sprung.

[0102] Among them, the 50hz low-pass filter of the unsprung and sprung longitudinal accelerations can be passed, and then the velocity can be obtained by integration, and the displacement can be obtained by further integration. The difference between the two displacements is the longitudinal (X-direction) displacement Disp_X of the unsprung mass relative to the sprung mass. The longitudinal stiffness Kx of the suspension system needs to be obtained by bench test or simulation. It should be noted that it is not only the stiffness of the linear section. In this case, it is defined that the force needs to be continuously applied until the entire suspension system fails, and the force-displacement curve at this time is recorded as the stiffness curve. Usually, the greater the force, the more obvious the nonlinearity.

[0103] When the unsprung vertical acceleration is less than the preset first acceleration threshold and the sprung vertical acceleration is less than the preset second acceleration threshold, if the vehicle is in an accelerating state, the longitudinal vehicle moment is determined according to the sprung longitudinal acceleration, and the longitudinal wheel center force of the vehicle is obtained by distributing the longitudinal vehicle moment. If the vehicle is in a braking state, the longitudinal wheel center force of the vehicle is calculated according to the wheel center braking moment and the wheel rolling radius of the vehicle.

[0104] Exemplarily, when az1 < 5g and az2 < 0.5g and the vehicle is accelerating, the longitudinal vehicle moment will be calculated according to the sprung longitudinal acceleration, and the longitudinal vehicle moment will be distributed to the four wheels according to the front and rear torque distribution ratio, so as to obtain the longitudinal wheel center force of the vehicle.

[0105] When az1 < 5g and az2 < 0.5g and the vehicle is braking, the longitudinal wheel center force of the vehicle is obtained by dividing the wheel center braking moment by the wheel rolling radius of the vehicle.

[0106] Furthermore, since the lateral (Y-direction) stiffness of the vehicle suspension is very large, it is simplified to calculate the lateral wheel center force of the vehicle according to the total mass of the front axle of the vehicle and the lateral acceleration of the front axle

[0107] FY = (M_front) * ay_front

[0108] Where, M_front is the total mass of the front axle of the vehicle, and ay_front is the lateral acceleration of the front axle of the vehicle.

[0109] Further, uniformly take the distance from the lateral (Y-direction) force application point of the wheel to the wheel center as the rolling radius - 100 mm as the loading point. According to the lateral force at the wheel center, the rolling radius of the wheel, and the distance between the lateral force application point of the wheel and the wheel center, the overturning moment at the wheel center is calculated as follows:

[0110] Mx = Fy * (rolling radius - 100 mm)

[0111] In the formula, Mx is the overturning moment at the wheel center, and Fy is the lateral force at the wheel center.

[0112] Further, according to the axial force of the steering tie rod of the vehicle and the acting distance between the acting point of the steering tie rod ball joint and the kingpin, the self-aligning moment at the wheel center is calculated as follows:

[0113] Mz = F * L

[0114] Where, Mz is the self-aligning moment at the wheel center, F is the axial force of the steering tie rod of the vehicle, and L is the acting distance between the acting point of the steering tie rod ball joint and the kingpin.

[0115] The six-component forces at the wheel center are obtained through the above method, and through a pre-defined multi-body model, the obtained six-component forces at the wheel center can be converted into real-time loads in each direction of each chassis component in the suspension system in real time, so that the force-time domain curves in each direction of each chassis component can be obtained. The specific conversion method will not be elaborated here.

[0116] In one embodiment, in step S102, according to the six-component forces at the wheel center, the real-time loads of each chassis component, and the strength-bearing capacity loads of each chassis component, the deformation states of each chassis component are determined. Specifically, it includes:

[0117] Step S1021: For any chassis component, when the six-component forces at the wheel center are all less than or equal to the wheel center loads converted from the yield points in each direction of this chassis component, determine that the deformation state of this chassis component is that no equivalent plastic strain occurs.

[0118] Step S1022: When the six-component forces at the wheel center are greater than the wheel center loads converted from the yield points in any direction of this chassis component and are all less than or equal to the wheel center loads converted from the PEEQ2% points in each direction, determine that this chassis component has a first-level equivalent plastic strain, and find the mapping relationship according to the real-time load of this chassis component to obtain the maximum equivalent plastic strain amount of this chassis component.

[0119] Explanatory, the six-wheel center forces may be greater than the wheel center loads converted from the yield points of the chassis components in multiple directions (taking two directions as an example). The mapping relationships in the corresponding directions are respectively searched according to the real-time loads in these two directions, the equivalent plastic strain amounts corresponding to the real-time loads in the two directions are obtained, and the maximum equivalent plastic strain amount among the two is determined as the final equivalent plastic strain amount of the chassis component.

[0120] Step S1023: When the six-wheel center forces are greater than the wheel center loads converted from the PEEQ2% points of the chassis component in any direction and are all less than the wheel center loads converted from the large deformation points or fracture points of each direction, it is determined that the chassis component has a secondary equivalent plastic strain, and the mapping relationship is searched according to the real-time load of the chassis component to obtain the maximum equivalent plastic strain amount of the chassis component.

[0121] The method for determining the maximum equivalent plastic strain amount here is the same as the above, and will not be elaborated here.

[0122] Step S1024: When the six-wheel center forces are greater than or equal to the wheel center loads converted from the large deformation points or fracture points of the chassis component in any direction, it is determined that the chassis component has large deformation or fracture.

[0123] In an embodiment, in step S103, based on the deformation states of the respective chassis components, the remaining lives of the respective chassis components are determined according to the real-time loads of the respective chassis components and the pseudo damage bases of the respective chassis components, which specifically includes:

[0124] Step S1031: For any chassis component, when the chassis component does not have an equivalent plastic strain, the cumulative pseudo damage of each direction of the chassis component is calculated in real time by the rain flow counting algorithm according to the six-wheel center forces, the cumulative pseudo damage of each direction of the chassis component is divided by the pseudo damage base in the corresponding direction to obtain the service lives of each direction, and the remaining life of the chassis component is determined according to the maximum service life.

[0125] Exemplarily, when a chassis component does not have an equivalent plastic strain, the cumulative pseudo damage of each of its directions is directly calculated in real time by rain flow counting. Taking the lower control arm as an example, the cumulative pseudo damage of each of its directions is shown in Table 3. The cumulative pseudo damage of each direction is divided by the pseudo damage bases of each direction predefined in Table 2 to obtain the relative ratios of pseudo damage of each direction as the service lives of each direction. The maximum service life is extracted. For example, the relative ratio of 10% in the Z direction of the wheel center is extracted from Table 3 as the maximum service life, then the remaining life of the lower control arm is calculated as 1 - 10% = 90%.

[0126] Table 3 Cumulative pseudo damage and relative ratios of each direction of the lower control arm

[0127]

[0128] Step S1032: When the deformation state of the chassis component is the first - order equivalent plastic strain or the second - order equivalent plastic strain, calculate the impact load damage of the chassis component according to the material type and the maximum equivalent plastic strain of the component, and obtain the damage life and the remaining life of the chassis component based on the impact load damage and the pseudo - damage base number in the corresponding direction.

[0129] Exemplarily, when the deformation state of the chassis component is the first - order equivalent plastic strain or the second - order equivalent plastic strain, and the material of the chassis component is aluminum alloy, calculate its impact load damage according to the following formula:

[0130] Damage = 2 / (10^log10(W) / 0.35) / (-0.69)

[0131] Where Damage is the impact load damage and W is the maximum equivalent plastic strain of the component.

[0132] When the material of the chassis component is steel, calculate its impact load damage according to the following formula:

[0133] Damage = 2 / (10^log10(W) / 0.59) / (-0.58)

[0134] Where Damage is the impact load damage and W is the maximum equivalent plastic strain of the component.

[0135] The damage life of the chassis component = (Damage / pseudo - damage base number in the corresponding direction) * 100%. At this time, the remaining life of the chassis component = the remaining life of the chassis component when no equivalent plastic strain occurs - the damage life of the chassis component.

[0136] Step S1033: When the deformation state of the chassis component is large deformation or fracture, determine that the remaining life of the chassis component is zero.

[0137] In one embodiment, step S104 issues a corresponding chassis component status notification according to the deformation state and the remaining life of each chassis component, in combination with the wheel center six - component forces and a preset driver impact feeling threshold, specifically including:

[0138] Step S1041: When no plastic strain occurs in all chassis components of the suspension system, if the longitudinal wheel center force is greater than the driver's longitudinal impact feeling threshold, the lateral wheel center force is greater than the driver's lateral impact feeling threshold, or the normal wheel center force is greater than the driver's normal impact feeling threshold, issue a first status notification indicating that the chassis components are undamaged; otherwise, do not issue a status notification.

[0139] Explanatory, in this implementation, a driver impact perception threshold is set to simulate the threshold point at which, in the driver's subjective perception, hitting a pothole is considered as "the vehicle has been damaged and needs to be parked for inspection or after-sales inspection". When the wheel center force is greater than the driver impact perception threshold, the user may feel that the driving condition is poor and be worried about the chassis condition of the vehicle. At this time, all chassis components have not exceeded the yield point, and the damage caused by a single impact is relatively small. A first status notification indicating that the chassis components are not damaged can be sent through the central control notification or voice prompt, etc., so as to relieve the panic of the driver. When the wheel center force does not exceed the driver impact perception threshold, it means that the current impact does not bring a sense of panic to the driver, so there will be no status notification, allowing the driver to focus on driving.

[0140] Step S1042: When there is a chassis component with a first-level equivalent plastic strain, send a second status notification indicating that the chassis component has a first-level equivalent plastic strain, and simultaneously display the chassis component with the first-level equivalent plastic strain and its remaining life.

[0141] Explanatory, taking the aluminum lower control arm of the chassis component as an example, its life will be greatly reduced only after 4000 times of bearing the yield point load. Then when the load reaches the load corresponding to PEEQ2%, it can only withstand about 15 impacts, and its life will be severely reduced. However, as a point considered in the design, when the deformation of the chassis component is between the yield point and the point of PEEQ2%, it does not affect normal driving. At this time, it is reminded that although the impact load is large and the damage life value of this time is large, (Damage / 1)*100%, but the design has considered it, and the driver is prompted to drive carefully. At the same time, the chassis components with slightly damaged chassis are displayed. At this time, the chassis components have small plastic deformations, but have little impact on driving, and the remaining life is also displayed synchronously.

[0142] Step S1043: When there is a chassis component with a second-level equivalent plastic strain, send a third status notification indicating that the chassis component with a second-level equivalent plastic strain needs to drive carefully, and simultaneously display the chassis component with the second-level equivalent plastic strain and its remaining life.

[0143] Exemplary, when the wheel center load calculated in real time is greater than the PEEQ2% point of the chassis component and less than the large deformation point or fracture limit point, at this time the chassis component is close to the cracking limit, or there is a large deformation of a component (the driver can obviously feel the abnormality), the central control directly warns the driver to be careful of vehicle damage, operate safely, and drive slowly to the nearest after-sales point for inspection.

[0144] Step S1044: When there is a large deformation or fracture of the chassis components, send a fourth status notification indicating that the large deformation or fracture of the chassis components makes safe driving impossible, synchronously display the deformed or fractured chassis components, and send the status of the chassis components to the after-sales end.

[0145] It should be noted that when the deformation amount of the chassis components exceeds the fracture limit and safe driving can no longer continue, the driver can clearly feel the abnormality at this time. The after-sales department promptly follows up to understand the driver's safety status and asks whether assistance is needed, such as towing.

[0146] The method for online evaluating the life of vehicle components provided by the embodiments of the present application realizes the transformation from traditional subjective judgment to objective data judgment by quantitatively calculating the damage of chassis components and grading them. This method can accurately evaluate the damage status of chassis components according to the forces received during the actual operation of the vehicle, and remind the driver whether inspection and treatment are needed according to the degree of damage. This not only avoids misdiagnosis and missed diagnosis that may occur during driving, but also significantly improves driving safety, and at the same time reduces the panic of drivers when the vehicle passes through complex road conditions. This method also has the function of real-time calculating and displaying the remaining life percentage of chassis components, which can help users judge at any time whether maintenance or replacement of chassis components is needed, thereby improving the service life and reliability of components.

[0147] In a second aspect, the embodiments of the present application also provide a device for online evaluating the life of vehicle components.

[0148] In one embodiment, referring to Figure 4 , Figure 4 is a schematic diagram of the functional modules of an embodiment of the device for online evaluating the life of vehicle components of the present application. As Figure 4 shown, the device for online evaluating the life of vehicle components includes:

[0149] An acquisition module, which is used to acquire the six-component force of the wheel center of the vehicle during the operation of the vehicle, and determine the real-time load of each chassis component in the suspension system of the vehicle according to the six-component force of the wheel center;

[0150] A first determination module, which is used to determine the deformation state of each chassis component according to the six-component force of the wheel center, the real-time load of each chassis component, and the strength bearing capacity load of each chassis component;

[0151] A second determination module, which is used to determine the remaining life of each chassis component based on the deformation state of each chassis component, according to the real-time load of each chassis component and the pseudo-damage base number of each chassis component;

[0152] A notification module, which is used to issue corresponding chassis component status notifications according to the deformation status and remaining life of each chassis component, in combination with the six-wheel-center forces and a preset driver impact feeling threshold. Further, in one embodiment, the acquisition module is further used for:

[0153] Calculating the six-wheel-center forces of the vehicle according to the unsprung acceleration, sprung acceleration, and relative compression displacement between the unsprung and sprung parts of the vehicle collected during the running of the vehicle.

[0154] Further, in one embodiment, the acquisition module is further used for:

[0155] Calculating the normal force of the wheel center of the vehicle according to the vertical stiffness of the suspension system, the relative compression displacement between the unsprung and sprung parts, the vertical damping coefficient of the suspension system, the relative compression speed between the unsprung and sprung parts, the unsprung mass of the vehicle, and the unsprung vertical acceleration;

[0156] Calculating the braking torque of the wheel center according to the braking hydraulic pipeline pressure, the piston area of the brake wheel cylinder, and the radius from the piston of the brake wheel cylinder to the wheel axle of the vehicle;

[0157] When the unsprung vertical acceleration is greater than or equal to a preset first acceleration threshold, or the sprung vertical acceleration is greater than or equal to a preset second acceleration threshold, calculating the longitudinal force of the wheel center of the vehicle according to the unsprung mass, the unsprung longitudinal acceleration, the longitudinal stiffness of the suspension system, and the longitudinal displacement of the unsprung relative to the sprung;

[0158] When the unsprung vertical acceleration is less than the preset first acceleration threshold and the sprung vertical acceleration is less than the preset second acceleration threshold, if the vehicle is in an accelerating state, determining the longitudinal torque of the whole vehicle according to the sprung longitudinal acceleration, and obtaining the longitudinal force of the wheel center of the vehicle by dividing the longitudinal torque of the whole vehicle; if the vehicle is in a braking state, calculating the longitudinal force of the wheel center of the vehicle according to the braking torque of the wheel center and the rolling radius of the vehicle wheel;

[0159] Calculating the lateral force of the wheel center of the vehicle according to the total mass of the front axle of the vehicle and the lateral acceleration of the front axle;

[0160] Calculating the overturning torque of the wheel center according to the lateral force of the wheel center, the rolling radius of the wheel, and the distance between the lateral force application point of the wheel and the wheel center;

[0161] Calculating the aligning torque of the wheel center according to the axial force of the steering tie rod of the vehicle and the acting distance between the ball joint of the steering tie rod and the kingpin;

[0162] Further, in one embodiment, the device is further used for:

[0163] Obtain the strength bearing capacity loads of each chassis component in each direction during the bench strength test, where the strength bearing capacity loads include the yield point load, the equivalent plastic strain PEEQ2% point load, and the large deformation point load or the fracture point load;

[0164] For each load value of each chassis component in each direction after the yield point load and before the large deformation point load or the fracture point load, combine the corresponding equivalent plastic strain amount to construct a corresponding mapping relationship;

[0165] Convert the strength bearing capacity loads of each chassis component in each direction into corresponding converted wheel center loads respectively, to obtain the yield point converted wheel center loads, the PEEQ2% point converted wheel center loads, and the large deformation point converted wheel center loads or the fracture point converted wheel center loads of each chassis component in each direction.

[0166] Further, in an embodiment, the first determination module is further configured to:

[0167] For any chassis component, when the wheel center six-component forces are all less than or equal to the yield point converted wheel center loads of each direction of the chassis component, determine that the deformation state of the chassis component is that no equivalent plastic strain has occurred;

[0168] When the wheel center six-component forces are greater than the yield point converted wheel center load of any direction of the chassis component and are all less than or equal to the PEEQ2% point converted wheel center loads of each direction, determine that the chassis component has undergone a first-level equivalent plastic strain, and look up the mapping relationship according to the real-time load of the chassis component to obtain the maximum equivalent plastic strain amount of the chassis component;

[0169] When the wheel center six-component forces are greater than the PEEQ2% point converted wheel center load of any direction of the chassis component and are all less than the large deformation point converted wheel center loads or the fracture point converted wheel center loads of each direction, determine that the chassis component has undergone a second-level equivalent plastic strain, and look up the mapping relationship according to the real-time load of the chassis component to obtain the maximum equivalent plastic strain amount of the chassis component;

[0170] When the wheel center six-component forces are greater than or equal to the large deformation point converted wheel center load or the fracture point converted wheel center load of any direction of the chassis component, determine that the chassis component has large deformation or fracture.

[0171] Further, in an embodiment, the device is further configured to:

[0172] When the vehicle undergoes a test field durability test, the Q-fold test field durability loads of each chassis component in each direction are used as the pseudo-damage bases of each direction of the corresponding chassis component.

[0173] Further, in one embodiment, the second determination module is further configured to:

[0174] For any chassis component, when the equivalent plastic strain of the chassis component does not occur, the cumulative pseudo-damage in each direction of the chassis component is calculated in real time according to the six-component wheel center force through the rain flow counting algorithm. The cumulative pseudo-damage in each direction of the chassis component is divided by the pseudo-damage base number in the corresponding direction to obtain the service life in each direction, and the remaining life of the chassis component is determined according to the maximum service life;

[0175] When the deformation state of the chassis component is primary equivalent plastic strain or secondary equivalent plastic strain, the impact load damage of the chassis component is calculated according to the material type and the maximum equivalent plastic strain of the component, and the damage life and the remaining life of the chassis component are obtained according to the impact load damage and the pseudo-damage base number in the corresponding direction;

[0176] When the deformation state of the chassis component is large deformation or fracture, it is determined that the remaining life of the chassis component is zero.

[0177] Further, in one embodiment, the notification module is further configured to:

[0178] When no plastic strain occurs in all chassis components in the suspension system, if the longitudinal wheel center force is greater than the driver's impact longitudinal perception threshold, the lateral wheel center force is greater than the driver's impact lateral perception threshold, or the normal wheel center force is greater than the driver's impact normal perception threshold, a first status notification for indicating that the chassis components are not damaged is issued; otherwise, no status notification is issued;

[0179] When there is a chassis component with primary equivalent plastic strain, a second status notification for indicating that the chassis component has primary equivalent plastic strain is issued, and the chassis component with primary equivalent plastic strain and its remaining life are synchronously displayed;

[0180] When there is a chassis component with secondary equivalent plastic strain, a third status notification for indicating that the chassis component with secondary equivalent plastic strain requires careful driving is issued, and the chassis component with secondary equivalent plastic strain and its remaining life are synchronously displayed;

[0181] When there is a chassis component with large deformation or fracture, a fourth status notification for indicating that the chassis component has large deformation or fracture and cannot drive safely is issued, and the chassis component with large deformation or fracture is synchronously displayed, and the status of the chassis component is sent to the after-sales end.

[0182] Further, in one embodiment:

[0183] The driver's impact longitudinal perception threshold is M times the maximum load-bearing wheel load of the vehicle;

[0184] The lateral impact perception threshold of the driver is N times the maximum load-bearing wheel load of the vehicle;

[0185] The normal impact perception threshold of the driver is R times the maximum load-bearing wheel load of the vehicle.

[0186] Among them, the function implementation of each module in the above device for online evaluating the lifespan of vehicle components corresponds to each step in the above method embodiment for online evaluating the lifespan of vehicle components, and its function and implementation process will not be elaborated here one by one.

[0187] It should be noted that the serial numbers of the above embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0188] The terms "including" and "having" and any variations thereof in the specification, claims and drawings of the present application are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally further include unlisted steps or units, or may optionally further include other steps or units inherent to these processes, methods, products or devices. The descriptions of "first", "second", "third", etc. are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit that "first", "second" and "third" are of different types.

[0189] In the description of the embodiments of the present application, "exemplary", "for example" or "for instance" etc. are used to indicate examples, illustrations or explanations. Any embodiment or design solution described as "exemplary", "for example" or "for instance" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary", "for example" or "for instance" is intended to present relevant concepts in a specific manner.

[0190] In the description of the embodiments of the present application, unless otherwise specified, " / " means "or". For example, A / B may mean A or B; "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B may mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "a plurality of" means two or more than two.

[0191] In some processes described in the embodiments of the present application, multiple operations or steps appear in a specific order. However, it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or may be executed in parallel. The serial numbers of the operations are only used to distinguish different operations, and the serial numbers themselves do not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0192] 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 application, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium as described above (such as ROM / RAM, magnetic disk, optical disc) and includes several instructions for causing a terminal device to execute the methods described in the various embodiments of the present application.

[0193] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. A method for online evaluation of the service life of vehicle parts, characterized in that, The method for online evaluating the service life of vehicle components includes: Obtaining the six-component wheel center force of the vehicle during vehicle operation, and determining the real-time loads of various chassis components in the vehicle's suspension system based on the six-component wheel center force; Determining the deformation states of various chassis components according to the six-component wheel center force, the real-time loads of various chassis components, and the strength-bearing capacity loads of various chassis components, where the strength-bearing capacity loads include the yield point load, the equivalent plastic strain PEEQ2% point load, and the large deformation point load or the fracture point load; Based on the deformation states of various chassis components, determining the remaining service lives of various chassis components according to the real-time loads of various chassis components and the pseudo-damage bases of various chassis components; Sending corresponding chassis component status notifications according to the deformation states and remaining service lives of various chassis components, in combination with the six-component wheel center force and a preset driver impact feeling threshold; 2. The method for online evaluating the lifespan of vehicle parts according to claim 1, characterized in that, Obtaining the six-component wheel center force of the vehicle during vehicle operation includes: Calculating the six-component wheel center force of the vehicle according to the unsprung acceleration, sprung acceleration, and sprung-unsprung relative compression displacement of the vehicle collected during vehicle operation.

3. The method for evaluating the life of vehicle parts by line as described in claim 2, characterized in that, The calculating the six-component wheel center force of the vehicle according to the unsprung acceleration, sprung acceleration, and sprung-unsprung relative compression displacement of the vehicle collected during vehicle operation includes: Calculating the normal force of the vehicle's wheel center according to the vertical stiffness of the suspension system, the sprung-unsprung relative compression displacement, the vertical damping coefficient of the suspension system, the sprung-unsprung relative compression speed, the unsprung mass of the vehicle, and the unsprung vertical acceleration; Calculating the wheel center braking torque according to the braking hydraulic line pressure of the vehicle, the piston area of the brake wheel cylinder, and the radius from the piston of the brake wheel cylinder to the wheel axle; When the unsprung vertical acceleration is greater than or equal to a preset first acceleration threshold, or the sprung vertical acceleration is greater than or equal to a preset second acceleration threshold, calculating the longitudinal force of the vehicle's wheel center according to the unsprung mass, the unsprung longitudinal acceleration, the longitudinal stiffness of the suspension system, and the longitudinal displacement of the unsprung relative to the sprung; When the unsprung vertical acceleration is less than the preset first acceleration threshold and the sprung vertical acceleration is less than the preset second acceleration threshold, if the vehicle is in an accelerating state, determining the longitudinal moment of the whole vehicle according to the sprung longitudinal acceleration and obtaining the longitudinal force of the vehicle's wheel center by dividing the longitudinal moment of the whole vehicle, if the vehicle is in a braking state, calculating the longitudinal force of the vehicle's wheel center with the wheel center braking torque and the rolling radius of the vehicle's wheel; Calculating the lateral force of the vehicle's wheel center according to the total mass of the front axle of the vehicle and the lateral acceleration of the front axle; Calculating the wheel center overturning moment according to the lateral force of the wheel center, the rolling radius of the wheel, and the distance between the lateral force application point of the wheel and the wheel center; Calculating the wheel center self-aligning moment according to the axial force of the steering tie rod of the vehicle and the acting distance between the ball joint of the steering tie rod and the kingpin.

4. The method for online evaluating the lifespan of vehicle parts according to claim 1, wherein Before determining the deformation states of each chassis component according to the six-wheel-center component forces, the real-time loads of each chassis component, and the strength-bearing capacity loads of each chassis component, it further includes: Obtaining the strength-bearing capacity loads in each direction of each chassis component in the bench strength test; For each load value of each chassis component in each direction after the yield point load and before the large deformation point load or the fracture point load, constructing a corresponding mapping relationship in combination with the corresponding equivalent plastic strain; Converting the strength-bearing capacity loads in each direction of each chassis component into corresponding converted wheel-center loads respectively, to obtain the yield point converted wheel-center loads, PEEQ2% point converted wheel-center loads, and large deformation point converted wheel-center loads or fracture point converted wheel-center loads in each direction of each chassis component.

5. The method for online evaluation of the service life of vehicle parts according to claim 4, characterized in that, Determining the deformation states of each chassis component according to the six-wheel-center component forces, the real-time loads of each chassis component, and the strength-bearing capacity loads of each chassis component, including: For any chassis component, when the six-wheel-center component forces are all less than or equal to the yield point converted wheel-center loads in each direction of this chassis component, determining that the deformation state of this chassis component is that no equivalent plastic strain has occurred; When the six-wheel-center component forces are greater than the yield point converted wheel-center load in any direction of this chassis component and are all less than or equal to the PEEQ2% point converted wheel-center loads in each direction, determining that this chassis component has undergone primary equivalent plastic strain, and searching for the above mapping relationship according to the real-time load of this chassis component to obtain the maximum equivalent plastic strain of this chassis component; When the six-wheel-center component forces are greater than the PEEQ2% point converted wheel-center load in any direction of this chassis component and are all less than the large deformation point converted wheel-center loads or fracture point converted wheel-center loads in each direction, determining that this chassis component has undergone secondary equivalent plastic strain, and searching for the above mapping relationship according to the real-time load of this chassis component to obtain the maximum equivalent plastic strain of this chassis component; When the six-wheel-center component forces are greater than or equal to the large deformation point converted wheel-center load or fracture point converted wheel-center load in any direction of this chassis component, determining that this chassis component has large deformation or fracture.

6. The method for online evaluation of the service life of vehicle parts according to claim 5, characterized in that, Before determining the remaining life of each chassis component based on the deformation states of each chassis component, according to the real-time loads of each chassis component and the pseudo-damage bases of each chassis component, it further includes: Regarding the Q-fold test field durability loads pseudo-damage in each direction of each chassis component during the test field durability test of the vehicle as the pseudo-damage base in each direction of the corresponding chassis component.

7. The method for online evaluating the lifespan of vehicle parts according to claim 6, wherein The determining the remaining life of each chassis component based on the deformation states of each chassis component, according to the real-time loads of each chassis component and the pseudo-damage bases of each chassis component, includes: For any chassis component, when no equivalent plastic strain occurs in the chassis component, the cumulative pseudo-damage in each direction of the chassis component is calculated in real time according to the six-component wheel center force through the rain flow counting algorithm. The cumulative pseudo-damage in each direction of the chassis component is divided by the pseudo-damage base number in the corresponding direction to obtain the service life in each direction, and the remaining life of the chassis component is determined according to the maximum service life; When the deformation state of the chassis component is the first-level equivalent plastic strain or the second-level equivalent plastic strain, the impact load damage of the chassis component is calculated according to the material type and the maximum equivalent plastic strain of the component, and the damage life and the remaining life of the chassis component are obtained according to the impact load damage and the pseudo-damage base number in the corresponding direction; When the deformation state of the chassis component is large deformation or fracture, it is determined that the remaining life of the chassis component is zero.

8. The method for online evaluation of the service life of vehicle parts according to claim 7, characterized in that, According to the deformation state and the remaining life of each chassis component, combined with the six-component wheel center force and the preset driver impact feeling threshold, corresponding chassis component status notifications are sent, including: When no plastic strain occurs in all chassis components in the suspension system, if the longitudinal wheel center force is greater than the driver's longitudinal impact feeling threshold, the lateral wheel center force is greater than the driver's lateral impact feeling threshold, or the normal wheel center force is greater than the driver's normal impact feeling threshold, a first status notification indicating that the chassis components are not damaged is sent; otherwise, no status notification is sent; When there is a chassis component with the first-level equivalent plastic strain, a second status notification indicating that the chassis component has the first-level equivalent plastic strain is sent, and the chassis component with the first-level equivalent plastic strain and its remaining life are synchronously displayed; When there is a chassis component with the second-level equivalent plastic strain, a third status notification indicating that the chassis component with the second-level equivalent plastic strain needs to drive carefully is sent, and the chassis component with the second-level equivalent plastic strain and its remaining life are synchronously displayed; When there is a chassis component with large deformation or fracture, a fourth status notification indicating that the chassis component with large deformation or fracture cannot drive safely is sent, the chassis component with large deformation or fracture is synchronously displayed, and the status of the chassis component is sent to the after-sales end.

9. The method for online evaluating the life of vehicle components according to claim 8, wherein: The driver's longitudinal impact feeling threshold is M times the maximum load-bearing wheel load of the vehicle; The driver's lateral impact feeling threshold is N times the maximum load-bearing wheel load of the vehicle; The driver's normal impact feeling threshold is R times the maximum load-bearing wheel load of the vehicle.

10. An apparatus for online evaluating the lifespan of vehicle components, characterized in that, The device for online evaluating the life of vehicle components includes: An acquisition module, which is used to acquire the six-component wheel center force of the vehicle during the operation of the vehicle and determine the real-time load of each chassis component in the suspension system of the vehicle according to the six-component wheel center force; A first determination module, which is configured to determine the deformation states of each chassis component according to the six-component force at the wheel center, the real-time loads of each chassis component, and the strength-bearing capacity loads of each chassis component, wherein the strength-bearing capacity loads include the yield point load, the equivalent plastic strain PEEQ2% point load, and the large deformation point load or the fracture point load; A second determination module, which is configured to determine the remaining life of each chassis component based on the deformation states of each chassis component, according to the real-time loads of each chassis component and the pseudo-damage bases of each chassis component; A notification module, which is configured to issue corresponding chassis component status notifications according to the deformation states and remaining lives of each chassis component, in combination with the six-component force at the wheel center and a preset driver impact feeling threshold.

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