A road simulation verification method for vehicle smoothness

Abstract

The present invention discloses a vehicle road simulation verification method for ride comfort. In the early stage of vehicle development, AD‑AMS / Car modeling is used to perform simulation analysis on a four-post test for ride comfort. For key data that need to be verified in the simulation analysis, a four-post vibration table is used to simulate and analyze the same vibration mode and excitation conditions. After the driving signal is determined in a simulation iteration manner, the four-post vibration table is used to excite the test vehicle to obtain test data to verify the simulation and optimization results. The structure and function of the vibration table are optimized, and the vehicle test sensors are reasonably arranged to obtain measured data, thereby providing effective verification for the ride comfort simulation and optimization results.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle ride comfort test and relates to a vehicle ride comfort simulation analysis verification method, which can realize accurate calculation, analysis and evaluation of vehicle ride comfort in the vehicle design stage. Background Art

[0002] As competition in the domestic and international automobile markets becomes increasingly fierce, consumers' requirements for driving comfort are increasing. Vehicle smoothness is one of the main performance indicators for evaluating driving comfort. However, it is difficult to achieve subjective evaluation of vehicle smoothness in the early stages of vehicle development. Therefore, in the early stages of development, various automobile companies use various technical methods to study and determine objective evaluation indicators of vehicle smoothness. If the vehicle smoothness can be accurately calculated, analyzed and evaluated in the automobile design stage, it can improve customer perceived quality while shortening the R&D cycle, reducing production costs and enhancing the market competitiveness of automobile companies.

[0003] At present, smoothness simulation analysis is the mainstream research method of automobile companies, which mainly uses standard signals such as sine, step and graded road as excitation, which is quite different from the actual situation. The paper "Vehicle Smoothness Simulation Research Based on ADAMS_Car_Ride" only uses virtual prototype technology to simulate vehicle smoothness, establishes a multi-body dynamics model based on ADAMS / Car Ride, and simulates the response characteristics of vehicles driving on rough roads and tires colliding with stones by inputting force or displacement data files to the virtual four-post test bench, and performs various time domain analyses, but there is no discussion on how to use the four-post test bench for simulation verification and which parameters to verify.

[0004] Road simulation test technology can reproduce the vibration conditions of a vehicle during actual road driving indoors. It has the characteristics of good repeatability and high safety. Many car companies are also using this technology to study vehicle smoothness.

[0005] CN112595521A provides a vehicle ride comfort simulation test method, which uses a four-post vibration table, inputs a speed sweep signal to simulate vibration, only collects the acceleration signal of the measurement point, and uses a 1 / 4 vehicle two-degree-of-freedom vibration model to analyze the influence of related parameters of the suspension system on the vibration characteristics. This method is an objective test method for vehicle ride comfort, but cannot meet the key parameter verification requirements of the present invention for simulation analysis of a four-post ride comfort test through AD-AMS / Car. Summary of the invention

[0006] In order to solve the above-mentioned problems existing in the prior art, the present invention provides a vehicle road simulation verification method for smoothness. In the early stage of vehicle development, AD-AMS / Car modeling is used to perform simulation analysis on a four-post test of smoothness. For key data that need to be verified in the simulation analysis, a four-post vibration table is used to simulate and analyze the same vibration mode and excitation conditions. After the driving signal is determined in a simulated iterative manner, the four-post vibration table is used to excite the test vehicle to obtain test data to verify the simulation and optimization results, the structural function of the vibration table is optimized, and the vehicle test sensors are reasonably arranged to obtain measured data, thereby providing effective verification for the smoothness simulation and optimization results.

[0007] The objective of the present invention is achieved through the following technical solutions:

[0008] A vehicle road ride simulation verification method comprises the following steps:

[0009] Step 1: Establishment of the vehicle ride comfort simulation model: Establish the vehicle simulation model through the mechanical system dynamics software ADAMS / Car;

[0010] Step 2: Calculation and analysis of four-pillar frequency sweep for ride comfort: Based on the four-pillar test bench module in ADAMS / Car, the vehicle simulation model is subjected to calculation and analysis of four-pillar frequency sweeps of equal amplitude and velocity, and the key simulation data are processed accordingly to obtain the corresponding objective evaluation parameters for ride comfort; the key simulation data include the sprung displacement transfer ratio, the ground load change rate, the sprung resonance frequency, the sprung 6Hz acceleration peak-to-peak value, and the sprung vibration damping ratio;

[0011] Step 3: Determine the target signal of the bench test: The test system software generates a simulated driving signal for stimulating the whole vehicle simulation model and converts it into a target signal for driving the four-column test bench. The target signal is divided into constant amplitude sweep and constant speed sweep;

[0012] Step 4, generating a test system driving signal: applying the whole vehicle durability bench test simulation iteration method, first solving the response function of the four-post vibration test bench, and then simulating and iterating to generate the four-post test bench driving signal;

[0013] Step 5: Determine the key simulation data, including:

[0014] 5.1) Simulation data test of sprung displacement transfer ratio, sprung resonance frequency and unsprung resonance frequency;

[0015] 5.2) Ground load change rate test;

[0016] 5.3) Spring vibration damping ratio and spring 6Hz acceleration peak-to-peak test;

[0017] Step 6: Drive the test system and collect data;

[0018] Step 7: Experimental data processing and comparative analysis: Process and analyze the collected data, draw corresponding curves, and provide experimental verification data for simulation analysis.

[0019] Furthermore, in step 3, the amplitude of the constant-amplitude frequency sweep is selected to be 5 mm or 10 mm, and the excitation frequency range is 0.5-30 Hz; the constant-speed frequency sweep speed is 50 mm / s or 100 mm / s, and the excitation frequency range is the same as the constant-amplitude frequency sweep condition.

[0020] Furthermore, in step 4, it is necessary to further determine whether the fitting accuracy between the generated four-column test bench drive signal and the expected target signal meets the verification requirements:

[0021] The root mean square error is set as the evaluation index. When the root mean square error ratio reaches or exceeds 10%, the iteration is completed and the final four-column test bench drive signal is generated;

[0022] The evaluation index is calculated by the following formula:

[0023] η=ΔErms / Drms

[0024] Where:

[0025] η is the root mean square error percentage;

[0026] ΔErms is the root mean square value of the target signal minus the root mean square value of the output signal;

[0027] Drms is the RMS value of the target signal.

[0028] Furthermore, in step 5.1), the laser displacement sensor and the wire displacement sensor are combined with the test method, and the displacement sensors are arranged on the wheel center and the wheel cover through the displacement test device to directly test the vibration table amplitude, unsprung displacement, body and wheel center displacement, and the sprung displacement is calculated by the following formula:

[0029] L=L1+L2+A

[0030] Where:

[0031] L--sprung displacement, unit: mm;

[0032] L1--Unsprung displacement, unit: mm;

[0033] L2--displacement between the vehicle body and the wheel center, unit: mm;

[0034] A--vibration table amplitude, unit: mm.

[0035] Furthermore, the displacement testing device includes: installing a flange at the center of the wheel, the outer end of the wheel hub bolt is a threaded rod, after locking the wheel, the outer end of the wheel hub bolt cooperates with the nut that fixes the flange to lock the flange; the center of the flange is connected to the stepped shaft through a threaded hole, the laser displacement sensor mounting seat is installed on the stepped shaft through a ball bearing, and the laser displacement sensor is installed and fixed at the bottom of the laser displacement sensor mounting seat; the fixing rod passes through the vehicle body sensor bracket to limit the rotation of the laser displacement sensor mounting seat; a wire-type displacement sensor support is installed at the wheel cover of the vehicle body just above the center of the wheel, the wire-type displacement sensor support is connected to the vehicle body after fixing the magnetic block through two hinges, one end of the adjustment rod is connected to the vehicle body through the hinge and the magnetic block, and the other end is connected to the wire-type displacement sensor support; after the wire-type displacement sensor is fixed to the wire-type displacement sensor support, one end of the wire is connected to the ear installed on the laser displacement sensor support.

[0036] As an alternative, the laser displacement sensor and the wire displacement sensor are combined with the test method in step 5.1, and the displacement sensors are arranged on the wheel center and the wheel cover through the displacement test device to directly test the vibration table amplitude, the displacement between the vehicle body and the wheel center, and the displacement between the vehicle body and the tray. The sprung displacement is calculated by the following formula:

[0037] L=L3+A

[0038] L1=L3-L2

[0039] Where:

[0040] L--sprung displacement, unit: mm;

[0041] L1--Unsprung displacement, unit: mm;

[0042] L2--displacement between the vehicle body and the wheel center, unit: mm;

[0043] L3—displacement between the vehicle body and the pallet, in mm;

[0044] A--vibration table amplitude, unit: mm.

[0045] Furthermore, the displacement testing device includes: a connecting flange is installed at the center of the wheel, the outer end of the wheel hub bolt is a threaded rod, after the wheel is locked, the outer end of the wheel hub bolt cooperates with the nut that fixes the flange to lock the flange; the center of the flange is connected to the stepped shaft through a threaded hole, a pull-wire displacement sensor support is installed at the wheel cover of the vehicle body just above the center of the wheel, and the pull-wire displacement sensor support is connected to the vehicle body after being fixed to a magnetic seat by two hinges; one end of the adjustment rod is connected to the vehicle body through a hinge and a magnetic seat, and the other end is connected to the pull-wire displacement sensor support. After the pull-wire displacement sensor is fixed to the pull-wire displacement sensor support, one end of the sensor wire is connected to the stepped shaft, and a laser displacement sensor is installed at another position of the pull-wire displacement sensor support to directly measure the displacement of the vehicle body and the pallet in a non-contact manner.

[0046] Furthermore, in the step 5.2) of the ground load change rate test, the load test tray assembly is connected and installed with the four-column actuator to support the wheel and collect the supported load force; the test tray assembly includes a tray lower connector, a single force sensor, an acceleration sensor and an upper tray; the tray lower connector is arranged at the lower part of the load test tray assembly, and is used to connect and fix the load test tray assembly to the actuator; three single force sensors are evenly fixed between the connector and the upper tray, and are used to collect the pressure; the unidirectional acceleration sensor is arranged on the lower side of the upper plate, and is used to collect the acceleration of the upper plate; the upper tray is used to contact the wheel.

[0047] Furthermore, during the test, the actuator is used to vibrate the entire vehicle, collect the signals of three single force sensors and acceleration sensors, calculate and analyze the signals, and obtain the actual load F borne by the upper plate of the load test system. The calculation formula is as follows:

[0048] F=F1+F2+F3-m·a

[0049] Among them, F1, F2, and F3 are the load force values ​​collected by three single force sensors respectively; m is the mass of the upper tray in the load test tray assembly; a is the acceleration value collected by the acceleration sensor;

[0050] The ground load change rate is expressed as a percentage and is calculated as follows:

[0051]

[0052] Where:

[0053] σ——ground load change rate, in %;

[0054] W——static wheel load, in N;

[0055] F——wheel load corresponding to the unsprung resonance frequency, in N.

[0056] Furthermore, the sprung vibration damping ratio and the sprung 6 Hz acceleration peak-to-peak value in step 5.3) include:

[0057] The sprung vibration damping ratio is calculated by the frequency response function with the unsprung acceleration as input x(t), the sprung acceleration as output y(t), and the suspension system as the transmission system;

[0058] The unsprung vibration damping ratio is calculated by the frequency response function with the acceleration of the tray as input x(t), the unsprung acceleration as output y(t), and the tire as the transmission system;

[0059] The unsprung acceleration is the vertical acceleration of the wheel center, and the sprung acceleration is the vertical acceleration of the vehicle body just above the wheel center.

[0060] For the definition of the frequency response function of the vibration system, x(t) is the system input and y(t) is the system output. The frequency response function of the system is H(f) and can be defined by the following formula:

[0061] H(f)=X(f) / Y(f)

[0062] Where:

[0063] X(f) is the Fourier transform of the system time domain input signal x(t);

[0064] Y(f) is the Fourier transform of the system time domain output signal y(t);

[0065] The vibration damping ratio can be calculated according to the frequency response function as follows:

[0066]

[0067] Where:

[0068] η——vibration damping ratio;

[0069] ω2——The frequency on the right side of the resonant frequency 3dB higher than the resonant frequency, in Hz;

[0070] ω1——the frequency 3dB below the left side of the resonant frequency, in Hz;

[0071] ω r ——Resonance frequency, in Hz.

[0072] The peak-to-peak value of the 6 Hz acceleration on the sprung portion is defined as the difference between the highest value and the lowest value of the acceleration signal at each location on the sprung portion within one cycle.

[0073] The present invention has the following beneficial effects:

[0074] The present invention uses AD-AMS / Car modeling to simulate and analyze the ride comfort four-post test in the early stage of vehicle development, and obtains test data by exciting the test vehicle with a four-post vibration table to verify the simulation and optimization results.

[0075] However, the verification of key data parameters such as displacement transfer ratio and ground load change rate in simulation analysis cannot be completed by using the existing four-column vibration table and the vehicle with only acceleration sensors. To this end, the present invention adds and reasonably arranges force load sensors and acceleration sensors on the existing four-column vibration table structure to implement a method for wheel ground load testing, which solves the problem that the existing vibration table cannot perform pallet load testing, or that the error in calculating the load after calibration of the vibration table pressure difference sensor is large. The ground load testing device of the present invention is easy to install and match with the existing actuator. The influence of the pallet inertial load is taken into account in the calculation of the test method, and the calculation result is accurate. At the same time, the additional bending moment caused by the eccentricity of the position caused by the wheel movement and the influence on the sensor life are taken into account.

[0076] At the same time, there is currently no accurate method for testing the vertical displacement of the wheel center during ride comfort test on a bench. The present invention adopts a displacement testing method for the vehicle wheel center position relative to the ground and the wheel center relative to the vehicle body, which solves the problem that the vertical displacement data of the wheel center and the ground tested is not accurate due to the movement of the vehicle in the front and rear and left and right directions during the test, and solves the problem that the method of arranging a conventional displacement sensor at the suspension shock absorber position to test the shock absorber displacement and then calculating the wheel center displacement change through the suspension kinematic model causes a large system error, or the benchmark vehicle has no dynamic model and cannot calculate the wheel center displacement.

[0077] In addition, while solving the above-mentioned testing problems, the present invention processes the test data through various theoretical formulas to obtain test parameters with the same loading conditions, working conditions and positions as the smoothness simulation analysis. The obtained test results are accurate and reliable, which provides accurate verification for vehicle smoothness control and optimization simulation, is conducive to accurately controlling the vehicle's smooth performance and shortening the project development cycle, and has important engineering application value for the research on vehicle smoothness methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 This is a flow chart of a vehicle road ride simulation verification method according to Embodiment 1 of the present invention;

[0079] Figure 2 A medium-amplitude sweep frequency target signal diagram in a vehicle road ride simulation verification method according to Embodiment 1 of the present invention;

[0080] Figure 3 A medium-speed sweep target signal diagram in a vehicle road ride simulation verification method according to Embodiment 1 of the present invention;

[0081] Figure 4 This is a schematic diagram of the structure of a displacement test device used in a vehicle road ride simulation verification method according to Embodiment 1 of the present invention;

[0082] Figure 5 This is a schematic structural diagram of a load test tray assembly used in a vehicle road ride simulation verification method according to Embodiment 1 of the present invention;

[0083] Figure 6 A frequency response function curve of a vehicle road ride simulation verification method according to Embodiment 1 of the present invention;

[0084] Figure 7 It is a schematic diagram of the assembly of a displacement test device, a load test tray assembly and a four-column stand used in a vehicle ride comfort road simulation verification method described in Example 1 of the present invention;

[0085] In the figure:

[0086] 1. Hub bolts; 2. Flange; 3. Nuts; 4. Stepped shaft; 5. Laser sensor mounting base; 6. Ball bearing; 7. Fastening nut; 8. Lifting lug; 9. Fixing rod; 10. Wire-type displacement sensor; 11. Adjusting rod; 12. Hinge; 13. Magnetic base; 14. Wire-type displacement sensor support; 15. Laser displacement sensor;

[0087] T1, connector; T2, single force sensor; T3, acceleration sensor; T4, upper tray. DETAILED DESCRIPTION

[0088] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0089] A vehicle road ride simulation verification method comprises the following steps:

[0090] Step 1: Establishment of the vehicle ride comfort simulation model: Establish the vehicle simulation model through the mechanical system dynamics software ADAMS / Car;

[0091] Step 2: Calculation and analysis of four-pillar frequency sweep for ride comfort: Based on the four-pillar test bench module in ADAMS / Car, the vehicle simulation model is subjected to calculation and analysis of four-pillar frequency sweeps of equal amplitude and velocity, and the key simulation data are processed accordingly to obtain the corresponding objective evaluation parameters for ride comfort; the key simulation data include the sprung displacement transfer ratio, the ground load change rate, the sprung resonance frequency, the sprung 6Hz acceleration peak-to-peak value, and the sprung vibration damping ratio;

[0092] Step 3: Determine the target signal of the bench test: The test system software generates a simulated driving signal for stimulating the whole vehicle simulation model and converts it into a target signal for driving the four-column test bench. The target signal is divided into constant amplitude sweep and constant speed sweep;

[0093] Step 4, generating a test system driving signal: applying the whole vehicle durability bench test simulation iteration method, first solving the response function of the four-post vibration test bench, and then simulating and iterating to generate the four-post test bench driving signal;

[0094] Step 5: Determine the key simulation data, including:

[0095] 5.1) Simulation data test of sprung displacement transfer ratio, sprung resonance frequency and unsprung resonance frequency;

[0096] 5.2) Ground load change rate test;

[0097] 5.3) Spring vibration damping ratio and spring 6Hz acceleration peak-to-peak test;

[0098] Step 6: Drive the test system and collect data;

[0099] Step 7: Experimental data processing and comparative analysis: Process and analyze the collected data, draw corresponding curves, and provide experimental verification data for simulation analysis.

[0100] Furthermore, in step 3, the amplitude of the constant-amplitude frequency sweep is selected to be 5 mm or 10 mm, and the excitation frequency range is 0.5-30 Hz; the constant-speed frequency sweep speed is 50 mm / s or 100 mm / s, and the excitation frequency range is the same as the constant-amplitude frequency sweep condition.

[0101] Furthermore, in step 4, it is necessary to further determine whether the fitting accuracy between the generated four-column test bench drive signal and the expected target signal meets the verification requirements:

[0102] The root mean square error is set as the evaluation index. When the root mean square error ratio reaches or exceeds 10%, the iteration is completed and the final four-column test bench drive signal is generated;

[0103] The evaluation index is calculated by the following formula:

[0104] η=ΔErms / Drms

[0105] Where:

[0106] η is the root mean square error percentage;

[0107] ΔErms is the root mean square value of the target signal minus the root mean square value of the output signal;

[0108] Drms is the RMS value of the target signal.

[0109] Furthermore, in step 5.1), the laser displacement sensor and the wire displacement sensor are combined with the test method, and the displacement sensors are arranged on the wheel center and the wheel cover through the displacement test device to directly test the vibration table amplitude, unsprung displacement, body and wheel center displacement, and the sprung displacement is calculated by the following formula:

[0110] L=L1+L2+A

[0111] Where:

[0112] L--sprung displacement, unit (mm);

[0113] L1--Unsprung displacement, unit (mm);

[0114] L2--displacement between vehicle body and wheel center, unit (mm);

[0115] A--vibration table amplitude, unit (mm).

[0116] Furthermore, the displacement testing device includes: installing a flange at the center of the wheel, the outer end of the wheel hub bolt is a threaded rod, after locking the wheel, the outer end of the wheel hub bolt cooperates with the nut that fixes the flange to lock the flange; the center of the flange is connected to the stepped shaft through a threaded hole, the laser displacement sensor mounting seat is installed on the stepped shaft through a ball bearing, and the laser displacement sensor 15 is installed and fixed at the bottom of the laser displacement sensor mounting seat; the fixing rod passes through the vehicle body sensor bracket to limit the rotation of the laser displacement sensor mounting seat; a pull-wire displacement sensor support is installed at the wheel cover of the vehicle body just above the center of the wheel, the pull-wire displacement sensor support is connected to the vehicle body after fixing the magnetic block through two hinges, one end of the adjustment rod is connected to the vehicle body through the hinge and the magnetic block, and the other end is connected to the pull-wire displacement sensor support; after the pull-wire displacement sensor is fixed to the pull-wire displacement sensor support, one end of the pull wire is connected to the ear installed on the laser displacement sensor support.

[0117] Furthermore, in step 5.1), the laser displacement sensor and the wire displacement sensor are combined with the test method, and the displacement sensors are arranged on the wheel center and the wheel cover through the displacement test device to directly test the vibration table amplitude, the displacement of the vehicle body and the wheel center, and the displacement of the vehicle body and the tray. The sprung displacement is calculated by the following formula:

[0118] L=L3+A

[0119] L1=L3-L2

[0120] Where:

[0121] L--sprung displacement, unit (mm);

[0122] L1--Unsprung displacement, unit (mm);

[0123] L2--displacement between vehicle body and wheel center, unit (mm);

[0124] L3—displacement between body and pallet, unit (mm);

[0125] A--vibration table amplitude, unit (mm).

[0126] Furthermore, the displacement testing device includes: a connecting flange is installed at the center of the wheel, the outer end of the wheel hub bolt is a threaded rod, after the wheel is locked, the outer end of the wheel hub bolt cooperates with the nut that fixes the flange to lock the flange; the center of the flange is connected to the stepped shaft through a threaded hole, a pull-wire displacement sensor support is installed at the wheel cover of the vehicle body just above the center of the wheel, and the pull-wire displacement sensor support is connected to the vehicle body after being fixed to a magnetic seat by two hinges; one end of the adjustment rod is connected to the vehicle body through a hinge and a magnetic seat, and the other end is connected to the pull-wire displacement sensor support. After the pull-wire displacement sensor is fixed to the pull-wire displacement sensor support, one end of the sensor wire is connected to the stepped shaft, and a laser displacement sensor is installed at another position of the pull-wire displacement sensor support to directly measure the displacement of the vehicle body and the pallet in a non-contact manner.

[0127] Furthermore, in the step 5.2) of the ground load change rate test, the load test tray assembly is connected and installed with the four-column actuator to support the wheel and collect the supported load force; the test tray assembly includes a tray lower connector, a single force sensor, an acceleration sensor and an upper tray; the tray lower connector is arranged at the lower part of the load test tray assembly, and is used to connect and fix the load test tray assembly to the actuator; three single force sensors are evenly fixed between the connector and the upper tray, and are used to collect the pressure; the unidirectional acceleration sensor is arranged on the lower side of the upper plate, and is used to collect the acceleration of the upper plate; the upper tray is used to contact the wheel.

[0128] Furthermore, during the test, the actuator is used to vibrate the entire vehicle, collect the signals of three single force sensors and acceleration sensors, calculate and analyze the signals, and obtain the actual load F borne by the upper plate of the load test system. The calculation formula is as follows:

[0129] F=F1+F2+F3-m·a

[0130] Among them, F1, F2, and F3 are the load force values ​​collected by three single force sensors respectively; m is the mass of the upper tray in the load test tray assembly; a is the acceleration value collected by the acceleration sensor;

[0131] The ground load change rate is expressed as a percentage and is calculated as follows:

[0132]

[0133] Where:

[0134] σ——ground load change rate, unit: (%);

[0135] W——static wheel load, unit: (N);

[0136] F——Wheel load corresponding to the unsprung resonance frequency, unit: (N).

[0137] Furthermore, the single force sensor is a resistive strain type single force sensor.

[0138] Furthermore, the sprung vibration damping ratio and the sprung 6 Hz acceleration peak-to-peak value in step 5.3) include:

[0139] The sprung vibration damping ratio is calculated by the frequency response function with the unsprung acceleration as input x(t), the sprung acceleration as output y(t), and the suspension system as the transmission system;

[0140] The unsprung vibration damping ratio is calculated by the frequency response function with the acceleration of the tray as input x(t), the unsprung acceleration as output y(t), and the tire as the transmission system;

[0141] The unsprung acceleration is the vertical acceleration of the wheel center, and the sprung acceleration is the vertical acceleration of the vehicle body just above the wheel center.

[0142] For the definition of the frequency response function of the vibration system, x(t) is the system input and y(t) is the system output. The frequency response function of the system is H(f) and can be defined by the following formula:

[0143] H(f)=X(f) / Y(f)

[0144] Where:

[0145] X(f) is the Fourier transform of the system time domain input signal x(t);

[0146] Y(f) is the Fourier transform of the system time domain output signal y(t).

[0147] The vibration damping ratio can be calculated according to the frequency response function as follows:

[0148]

[0149] Where:

[0150] η——vibration damping ratio;

[0151] ω2——The frequency on the right side of the resonance frequency 3dB higher than the resonance frequency, in (Hz);

[0152] ω1——The frequency 3dB below the left side of the resonant frequency, in (Hz);

[0153] ωr ——Resonance frequency, unit: (Hz).

[0154] The peak-to-peak value of the 6 Hz acceleration on the sprung portion is defined as the difference between the highest value and the lowest value of the acceleration signal at each location on the sprung portion within one cycle.

[0155] Example 1

[0156] like Figure 1 As shown, a vehicle road ride simulation verification method comprises the following steps:

[0157] Step 1: Establishment of vehicle ride comfort simulation model

[0158] The whole vehicle simulation model is established through the mechanical system dynamics software ADAMS / Car. The subsystems of the whole vehicle simulation model should include front and rear suspension systems, steering systems, body systems, tire models, etc.

[0159] Step 2: Four-column frequency sweep calculation and analysis for smoothness

[0160] Based on the four-post test bench module (ARIDE_FOUR_POSTTESTRIG) in ADAMS / Car, the vehicle simulation model is subjected to equal amplitude and velocity sweep calculations and analysis of the four-post smoothness, and the key simulation data are processed accordingly to obtain the corresponding objective evaluation parameters of smoothness. The key simulation data include the displacement transfer ratio on the sprung, the ground load change rate, the resonant frequency on the sprung, the peak-to-peak value of the 6Hz acceleration on the sprung, and the vibration damping ratio on the sprung.

[0161] Step 3: Determine the target signal for bench test

[0162] To verify the simulation analysis results, the test system software generates a simulated driving signal for stimulating the whole vehicle simulation model and converts it into a target signal that can be executed by the four-post test bench. The target signal is divided into equal-amplitude sweep and equal-speed sweep. The driving mode can be selected as the same-phase sweep of the front and rear axles (vertical bounce), the anti-phase sweep of the left and right wheels (roll), and the anti-phase sweep of the front and rear axles (pitch). The frequency growth rate can be selected as 0.1Hz / s.

[0163] The amplitude of the constant frequency sweep can be selected as 5mm or 10mm, and the excitation frequency range can be selected as 0.5-30Hz. The target signal is as follows Figure 2 The constant frequency sweep speed can be 50mm / s, 100mm / s, etc. The excitation frequency range can be the same as the constant amplitude sweep condition. The target signal is as follows: Figure 3 shown.

[0164] Step 4: Generate the test system drive signal (because professionals are familiar with this iterative method, only evaluation indicators are given)

[0165] Due to the nonlinearity of the bench vibration test, in order to ensure the desired target signal, the whole vehicle durability bench test simulation iteration method can be applied to first solve the response function of the four-post vibration test bench, and then simulate and iterate to generate the four-post test bench drive signal. In order to avoid the influence of the bench test load change on the drive signal, the present invention requires that the test vehicle be placed on the four-post test bench during the simulation iteration.

[0166] At the same time, a judgment method needs to be set to evaluate whether the fitting accuracy between the test bench output signal and the expected target signal meets the verification requirements: the root mean square error can be set as the evaluation index. When the root mean square error ratio reaches or exceeds 10%, the iteration is completed and the final test bench drive signal is generated. The evaluation index can be calculated by the following formula:

[0167] η=ΔErms / Drms

[0168] Where:

[0169] η is the root mean square error percentage;

[0170] ΔErms is the root mean square value of the target signal minus the root mean square value of the output signal;

[0171] Drms is the RMS value of the target signal.

[0172] Step 5: Determine the key simulation data:

[0173] The test system drive signal generated in step 4 is sent to the four-post test bench. After receiving the signal, the four-post test bench takes action to stimulate the test vehicle to move, which is an external input condition for the test vehicle. However, the four-post test bench drive signal needs to be the same as the excitation signal of the simulated four-post test bench applied by the simulation analysis software; in order to obtain key simulation data, it is also necessary to test the data of different positions of the vehicle during the vehicle movement. This step is to formulate a test plan for the test vehicle in order to obtain key simulation data, including sensor selection, layout, calculation and processing, etc.

[0174] 5.1) Testing method of simulation data of sprung displacement transfer ratio, sprung resonance frequency and unsprung resonance frequency:

[0175] The method of the present invention defines: the sprung displacement transfer ratio is the ratio of the sprung displacement to the excitation amplitude at resonance; the sprung displacement is defined as the displacement of the vehicle body directly above the wheel center relative to the ground, and the unsprung displacement is defined as the displacement of the wheel center relative to the vibration table tray; the sprung resonance frequency refers to the frequency corresponding to the maximum value of the sprung displacement; the unsprung resonance frequency refers to the frequency corresponding to the maximum value of the unsprung displacement.

[0176] Displacement testing in engineering is generally performed using displacement sensors, which can usually be divided into wire-type displacement sensors and LVDT displacement sensors. For the vibration test of a four-pillar vehicle, since the vehicle is not fixed during the test, it will move forward and backward and left and right. At the same time, it is limited by the test vibration table and cannot be arranged to directly test the displacement changes on and under the sprung springs. For this reason, the present invention proposes a test method combining a laser displacement sensor and a wire-type displacement sensor. The displacement sensor is arranged on the wheel center and wheel cover through a structural fixture for direct testing. The assembly is as follows: Figure 4 shown.

[0177] The displacement test scheme is:

[0178] A connecting flange 2 is installed at the center of the wheel. The flange has five spoke-shaped holes arranged in equal parts on the circumference of a circle. The special hub bolt 1 is used to install the wheel. Its outer end is a threaded rod. After locking the wheel, the outer ends of the five hub bolts cooperate with the nuts 3 that fix the flange to lock the flange. The center of the flange is connected to the stepped shaft 4 through a threaded hole. A laser displacement sensor mounting seat 5 with ball bearings 6 at both ends is installed on the stepped shaft. The mounting seat 5 is fixed to the stepped shaft 4 by a tightening nut 7. A laser displacement sensor 15 is installed at the bottom of the mounting seat. A fixing rod 9 is installed near the end of the flange side, which passes through the wire-type displacement sensor support 1414 to limit the rotation of the laser displacement sensor mounting seat 5. A wire-type displacement sensor support 14 is installed on the wheel arch of the vehicle body just above the center of the wheel. In order to facilitate installation and not damage the vehicle paint, the wire-type displacement sensor support 14 adopts three-point support. Two hinges 12 are connected to the vehicle body after fixing the magnetic block 13. One end of the length-adjustable adjustment rod 11 is connected to the vehicle body through the hinge and the magnetic block, and the other end is connected to the wire-type displacement sensor support 14. The wire-type displacement sensor support 14 is kept in a horizontal position by adjusting the length of the rod 11. After the wire-type displacement sensor 10 is fixed to the wire-type displacement sensor support 14, one end of the sensor wire is connected to the ear 8 installed on the laser displacement sensor support, and the wire-type displacement sensor support 14 is processed with a round hole for connecting with the fixing rod 9.

[0179] During the test, the vibration table amplitude, unsprung displacement, body and wheel center displacement are tested simultaneously, and the sprung displacement can be calculated by the following formula:

[0180] L=L1+L2+A

[0181] Where:

[0182] L--sprung displacement, unit (mm);

[0183] L1--Unsprung displacement, unit (mm);

[0184] L2--displacement between vehicle body and wheel center, unit (mm);

[0185] A--vibration table amplitude, unit (mm).

[0186] The collected time domain displacement signals can be Fourier transformed using data processing software such as nCode or Matlab to transform the time domain signals into frequency domain amplitude signals, and finally the sprung displacement transfer ratio, sprung and unsprung resonance frequencies can be obtained.

[0187] 5.2) Ground load change rate test method:

[0188] The ground load change rate defined in the present invention is the difference between the vertical load at the four-column tray and the wheel corresponding to the unsprung resonance frequency and the static load of the wheel.

[0189] At present, the four-post bench test bench is mainly used for the whole vehicle durability road simulation test, in which the four hydraulic or electric actuators are the loading devices in the vibration test. The simulation iteration target is the vehicle axle head acceleration and suspension displacement signal. The test bench displacement is controlled to perform vibration loading, drive the vehicle to vibrate, and realize the reliability assessment of the vehicle. There is no requirement for the vehicle wheel load, so force load sensors are usually not configured. To realize the tire ground load test in the smoothness test, the prior art lacks an accurate measurement method for the load on the four-post bench tray, which makes many tests difficult to conduct. Some can be realized after calibration of the test bench pressure difference sensor, but the error is large and the test load collection is inaccurate. To this end, the present invention proposes a load testing system and test method for a four-post actuator, which is easy to install and easy to match with the existing actuator, and the influence of the tray inertia load is considered in the calculation of the test method, and the calculation result is accurate.

[0190] The ground load change rate test scheme is:

[0191] Design a load test tray assembly, see Figure 7 The assembly is connected to the four-column actuator and is used to support the wheels and collect the supported load force. Figure 5As shown, the test tray assembly includes: a tray lower connector T1, a single force sensor T2, an acceleration sensor T3 and an upper tray T4. The tray lower connector is arranged at the lower part of the load test tray assembly, and is used to connect and fix the load test tray assembly with the actuator to transmit the vibration action of the actuator. The single force sensor can be a resistive strain type, fixed between the connector and the upper tray, and is used to collect the pressure. Three single force sensors are combined into a sensor unit, which jointly bears the tray and measures the force. The three sensors are evenly arranged, which can effectively eliminate the inaccurate measurement of the tray caused by the wheel bias and reduce the damage to the sensor caused by the bending moment while increasing the structural stability. The unidirectional acceleration sensor is arranged on the lower side of the upper plate, and is used to collect the acceleration of the upper plate. When calculating the load, the inertial load caused by the mass can be included, and the influence of the inertial load of the upper plate itself on the load measurement is eliminated. The upper tray is used to contact with the wheel. In order to reduce the wear of the plate surface, the surface is coated with wear-resistant material, which can reduce the wear of the plate surface during vibration. During the test, the actuator is used to vibrate the vehicle, collect the signals of three single force sensors and acceleration sensors, and calculate and analyze the signals through the corresponding calculation method to obtain the actual load borne by the upper plate of the load test system. The calculation formula F adopts the following formula:

[0192] F=F1+F2+F3-m·a

[0193] Among them, F1, F2, and F3 are the load force values ​​collected by three single force sensors respectively; m is the mass of the upper tray in the load test tray assembly; and a is the acceleration value collected by the acceleration sensor.

[0194] The ground load change rate of this method is calculated as a percentage according to the following formula:

[0195]

[0196] Where:

[0197] σ——ground load change rate, unit: (%);

[0198] W——static wheel load, unit: (N);

[0199] F——Wheel load corresponding to the unsprung resonance frequency, unit: (N).

[0200] 5.3) Test methods for sprung vibration damping ratio, 6Hz acceleration peak-to-peak value, etc.

[0201] The vibration attenuation of the sprung and unsprung masses has a great influence on the ride comfort of the whole vehicle, and the vibration damping ratio is an important indicator for evaluating the attenuation. The sprung vibration damping ratio of the present invention is defined as the unsprung acceleration as the input x(t), the sprung acceleration as the output y(t), and the suspension system as the transmission system, and is calculated through the frequency response function. The unsprung vibration damping ratio is calculated through the frequency response function using the acceleration of the tray as the input x(t), the unsprung acceleration as the output y(t), and the tire as the transmission system. The unsprung acceleration is the vertical acceleration of the wheel center, and the sprung acceleration is the vertical acceleration of the vehicle body directly above the wheel center.

[0202] For the definition of the frequency response function of the vibration system, x(t) is the system input and y(t) is the system output. The frequency response function of the system is H(f) and can be defined by the following formula:

[0203] H(f)=X(f) / Y(f)

[0204] Where:

[0205] X(f) is the Fourier transform of the system time domain input signal x(t);

[0206] Y(f) is the Fourier transform of the system time domain output signal y(t).

[0207] The vibration damping ratio can be calculated according to the frequency response function. The frequency response function curve is as follows: Figure 6 As shown:

[0208]

[0209] Where:

[0210] η——vibration damping ratio;

[0211] ω2——The frequency on the right side of the resonance frequency 3dB higher than the resonance frequency, in (Hz);

[0212] ω1——The frequency 3dB below the left side of the resonant frequency, in (Hz);

[0213] ω r ——Resonance frequency, unit: (Hz).

[0214] The 6Hz peak-to-peak value of acceleration defined in the present invention is defined as the difference between the highest value and the lowest value of the acceleration signal of each part such as the seat within one cycle. In order to obtain acceleration verification data in simulation analysis, acceleration sensors can be arranged at the suspension, body, seat rails, seats, etc. The collected time domain acceleration signals can be Fourier transformed using data processing software such as nCode or Matlab to transform the time domain signals into frequency domain amplitude signals.

[0215] Step 6: Drive the test system and collect data

[0216] like Figure 7 As shown, the sensor arrangement is complete. Before the test begins, an optional 4Hz~8Hz, 10mm amplitude sweep vibration should be performed for at least 5 minutes to ensure that the shock absorber reaches the normal working temperature.

[0217] The test is carried out according to the vibration mode and excitation requirements used in the simulation analysis. To improve the accuracy of the test results, the number of effective tests for each working condition shall not be less than 3 times (the sampling frequency shall not be less than 100 Hz, and the change in the peak value of the excitation signal can be defined as not exceeding 10% of the target within the excitation frequency range, that is, the test data is considered valid).

[0218] Step 7: Experimental data processing and comparative analysis

[0219] The collected data are processed and analyzed, and the corresponding curves are drawn to provide experimental verification data for simulation analysis.

[0220] Example 2

[0221] The difference between Example 2 and Example 1 is that:

[0222] In step 5.1), the displacement test scheme is:

[0223] A connecting flange is installed at the center of the wheel. The flange has five spoke-shaped holes arranged in equal parts on the circumference of a circle. The hub bolt 1 is used to install the wheel, and its outer end is a threaded rod. After locking the wheel, the outer ends of the five hub bolts cooperate with the nuts 3 that fix the flange to lock the flange. The center of the flange is connected to the stepped shaft 4 through a threaded hole, and a pull-wire displacement sensor support 14 is installed on the wheel cover part of the vehicle body just above the center of the wheel. In order to facilitate installation and not damage the car paint, the bracket adopts three-point support, and is connected to the vehicle body after fixing the magnetic seat 13 through two hinges 12. One end of the length-adjustable adjustment rod 11 is connected to the vehicle body through a hinge and a magnetic seat. The angles of the three hinge magnetic seats are adjustable to ensure fixation with various curved vehicle bodies. It is universal and easy to disassemble and assemble. The other end is connected to the pull-wire displacement sensor support 14, and the support 14 is kept in a horizontal position by adjusting the length of the pull rod 11. After the pull-wire displacement sensor 10 is fixed to the support 14, one end of the sensor pull wire is connected to the stepped shaft 4, and a laser displacement sensor is installed at another position of the sensor support 14 to directly measure the displacement of the vehicle body and the pallet in a non-contact manner.

[0224] During the test, the vibration table amplitude, the displacement of the vehicle body and the wheel center, and the displacement of the vehicle body and the tray are tested simultaneously. The sprung displacement can be calculated by the following formula:

[0225] L=L3+A

[0226] L1=L3-L2

[0227] Where:

[0228] L--sprung displacement, unit (mm);

[0229] L1--Unsprung displacement, unit (mm);

[0230] L2--displacement between vehicle body and wheel center, unit (mm);

[0231] L3—displacement between body and pallet, unit (mm);

[0232] A--vibration table amplitude, unit (mm).

[0233] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0234] The technical solution of the present invention has the following advantages:

[0235] A ride comfort simulation analysis verification method of the present invention takes simulation analysis key data parameters as verification targets, and under the premise of using a conventional four-column vibration test bench to excite and load a test vehicle, applies a displacement combination test method and a load test tray assembly, and converts the actually measured data into key data parameters and curves corresponding to the simulation analysis through processing.

[0236] The displacement test method adopted by the present invention determines the sprung displacement by testing the body and wheel center, wheel center and tray, and actuator amplitude. A wire-type displacement sensor is used from the wheel center to the body, and a non-contact laser displacement sensor is used from the wheel center to the tray. A connecting flange is installed at the center of the wheel. The flange has five spoke-shaped holes arranged in equal parts on the circumference of a circle. It is suitable for wheels of different models and has universality. Special hub bolts are used to install the wheel. The outer end of the hub bolt is provided with a thread. After locking the wheel, it cooperates with the nut that fixes the flange to lock the flange.

[0237] The present invention provides two displacement testing schemes, in which the center of a flange is connected to a stepped shaft through a threaded hole, a laser displacement sensor mounting seat with bearings at both ends is installed on the stepped shaft, the mounting seat is fixed to the stepped shaft through a nut, a threaded hole is provided at the bottom of the mounting seat to mount the laser displacement sensor, and the end portion close to the flange is restricted from rotating by a fixing rod to ensure that the light emitted by the laser displacement sensor is always vertical to the upper surface of the tray.

[0238] Another displacement test solution is to install a displacement sensor bracket on the wheel arch of the vehicle body just above the center of the wheel. To facilitate installation and avoid damaging the vehicle paint, the bracket is supported at three points and connected to the vehicle body with a magnetic base. The length of the adjustment rod is adjustable, and the angles of the three magnetic bases are adjustable to ensure that the sensor bracket is horizontal and the bracket can be fixed to different curved vehicle bodies. It is universal and easy to disassemble and assemble.

[0239] The wheel tray load test method adopted by the present invention calculates and obtains the wheel load by testing the data of three force sensors and one acceleration sensor. The tray assembly of the load test method includes a tray lower connector, a single force sensor, an acceleration sensor and an upper tray. The tray lower connector is arranged at the lower part of the load test tray assembly, and is used to connect and fix the load test tray assembly with the actuator to transmit the vibration action of the actuator.

[0240] The present invention provides a wheel-tray load test solution, in which a single force sensor can be of resistive strain type, fixed between the connector and the upper tray, and used to collect the pressure. Three single force sensors are combined into a sensor unit, which jointly supports the tray and measures the force. The three sensors are evenly distributed, which can effectively eliminate the inaccurate measurement of the tray caused by the wheel bias and reduce the damage to the sensor caused by the bending moment while increasing the structural stability. The unidirectional acceleration sensor is arranged on the lower side of the upper tray and is used to collect the acceleration of the upper tray. When calculating the load, the inertial load caused by the mass can be included to eliminate the influence of the upper tray's own inertial load on the load measurement. At the same time, the surface of the upper tray should be coated with wear-resistant materials to reduce the wear of the tray and the wheel, and high-strength lightweight materials should be used to reduce the influence of its own inertial load.

[0241] A smoothness simulation analysis verification method of the present invention requires that an optional frequency sweep vibration with an amplitude of 4 Hz to 8 Hz and 10 mm should be performed for at least 5 minutes before the test begins to ensure that the shock absorber reaches a normal working temperature.

[0242] The present invention provides a smoothness simulation analysis verification method to improve the accuracy of test results. The number of effective tests for each working condition is not less than 3 times (the sampling frequency is not less than 100 Hz, and the change in the peak value of the excitation signal can be defined as not exceeding 10% of the target within the excitation frequency range, that is, the test data is considered valid).

Claims

1. A vehicle road ride simulation verification method, characterized in that: The following steps are involved: Step 1: Establishment of the whole vehicle ride comfort simulation model: Establish the whole vehicle simulation model through the mechanical system dynamics software ADAMS / Car; Step 2: Calculation and analysis of four-pillar frequency sweep for ride comfort: Based on the four-pillar test bench module in ADAMS / Car, the vehicle simulation model is subjected to calculation and analysis of four-pillar frequency sweeps of equal amplitude and velocity, and the key simulation data are processed accordingly to obtain the corresponding objective evaluation parameters for ride comfort; the key simulation data include the sprung displacement transfer ratio, the ground load change rate, the sprung resonance frequency, the sprung 6Hz acceleration peak-to-peak value, and the sprung vibration damping ratio; Step 3, determine the bench test target signal: the test system software generates a simulated drive signal for stimulating the vehicle simulation model and converts it into a target signal for driving the four-post test bench. The target signal is divided into a constant amplitude sweep and a constant speed sweep; Step 4, generating a test system driving signal: applying the whole vehicle durability bench test simulation iteration method, first solving the response function of the four-post vibration test bench, and then simulating and iterating to generate the four-post test bench driving signal; Step 5: Determine the key simulation data, including: 5.1) Simulation data test of sprung displacement transmission ratio, sprung resonance frequency and unsprung resonance frequency; the step 5.1) combines the laser displacement sensor and the wire displacement sensor with the test method, arranges the displacement sensor on the wheel center and the wheel cover through the displacement test device, directly tests the vibration table amplitude, unsprung displacement, body and wheel center displacement, and the sprung displacement is calculated by the following formula: L=L1+L2+A Where: L--sprung displacement, unit: mm; L1--Unsprung displacement, unit: mm; L2--displacement between the vehicle body and the wheel center, unit: mm; A--vibration table amplitude, unit: mm; The displacement testing device comprises: a flange is installed at the center of the wheel, the outer end of the wheel hub bolt is a threaded rod, after the wheel is locked, the outer end of the wheel hub bolt cooperates with the nut fixing the flange to lock the flange; the center of the flange is connected to the stepped shaft through a threaded hole, the laser displacement sensor mounting seat is installed on the stepped shaft through a ball bearing, and the laser displacement sensor is installed and fixed at the bottom of the laser displacement sensor mounting seat; the fixing rod passes through the vehicle body sensor bracket seat to limit the rotation of the laser displacement sensor mounting seat; a pull-wire displacement sensor support is installed at the wheel cover of the vehicle body just above the center of the wheel, the pull-wire displacement sensor support is connected to the vehicle body after fixing the magnetic block through two hinges, one end of the adjustment rod is connected to the vehicle body through the hinge and the magnetic block, and the other end is connected to the pull-wire displacement sensor support; after the pull-wire displacement sensor is fixed to the pull-wire displacement sensor support, one end of the pull wire is connected to the hanging ear installed on the laser displacement sensor support; 5.2) Ground load change rate test; 5.3) Spring vibration damping ratio and spring 6Hz acceleration peak-to-peak test; Step 6: Drive the test system and collect data; Step 7: Experimental data processing and comparative analysis: Process and analyze the collected data, draw corresponding curves, and provide experimental verification data for simulation analysis.

2. A vehicle road ride simulation verification method as claimed in claim 1, characterized in that: In step 3, the amplitude of the constant-amplitude frequency sweep is 5 mm or 10 mm, and the excitation frequency range is 0.5-30 Hz; the constant-speed frequency sweep speed is 50 mm / s or 100 mm / s, and the excitation frequency range is the same as the constant-amplitude frequency sweep condition.

3. A vehicle road ride simulation verification method as claimed in claim 1, characterized in that: In step 4, it is necessary to further determine whether the fitting accuracy between the generated four-column test bench drive signal and the expected target signal meets the verification requirements: The root mean square error is set as the evaluation index. When the root mean square error ratio reaches or exceeds 10%, the iteration is completed and the final four-column test bench drive signal is generated; The evaluation index is calculated by the following formula: η=ΔErms / Drms Where: η is the root mean square error percentage; ΔErms is the root mean square value of the target signal minus the root mean square value of the output signal; Drms is the RMS value of the target signal.

4. A vehicle road ride simulation verification method as claimed in claim 1, characterized in that: In step 5.1), the laser displacement sensor and the wire displacement sensor are combined with the test method. Through the displacement test device, the displacement sensors are arranged on the wheel center and the wheel cover to directly test the vibration table amplitude, the displacement of the vehicle body and the wheel center, and the displacement of the vehicle body and the tray. The sprung displacement is calculated by the following formula: L=L3+A L1=L3-L2 Where: L--sprung displacement, unit: mm; L1--Unsprung displacement, unit: mm; L2--displacement between the vehicle body and the wheel center, unit: mm; L3—displacement between the vehicle body and the pallet, in mm; A--vibration table amplitude, unit: mm.

5. A vehicle road ride simulation verification method as claimed in claim 4, characterized in that: The displacement testing device comprises: a connecting flange is installed at the center of the wheel, the outer end of the wheel hub bolt is a threaded rod, after the wheel is locked, the outer end of the wheel hub bolt cooperates with the nut that fixes the flange to lock the flange; the center of the flange is connected to the stepped shaft through a threaded hole, a pull-wire displacement sensor support is installed at the wheel cover of the vehicle body just above the center of the wheel, and the pull-wire displacement sensor support is connected to the vehicle body after being fixed to a magnetic seat by two hinges; one end of the adjustment rod is connected to the vehicle body through a hinge and a magnetic seat, and the other end is connected to the pull-wire displacement sensor support, after the pull-wire displacement sensor is fixed to the pull-wire displacement sensor support, one end of the sensor wire is connected to the stepped shaft, and a laser displacement sensor is installed at another position of the pull-wire displacement sensor support to directly measure the displacement of the vehicle body and the pallet in a non-contact manner.

6. A vehicle road ride simulation verification method as claimed in claim 1, characterized in that: In the step 5.2) of the ground load change rate test, the load test tray assembly is connected and installed with the four-column actuator to support the wheel and collect the supported load force; the test tray assembly includes a tray lower connector, a single force sensor, an acceleration sensor and an upper tray; the tray lower connector is arranged at the lower part of the load test tray assembly, and is used to connect and fix the load test tray assembly to the actuator; three single force sensors are evenly fixed between the connector and the upper tray, and are used to collect the pressure; the unidirectional acceleration sensor is arranged on the lower side of the upper plate, and is used to collect the acceleration of the upper plate; the upper tray is used to contact the wheel.

7. A vehicle road ride simulation verification method as claimed in claim 6, characterized in that: During the test, the actuator is used to vibrate the vehicle, collect the signals of three single force sensors and acceleration sensors, calculate and analyze the signals, and obtain the actual load F borne by the upper plate of the load test system. The calculation formula is as follows: F=F1+F2+F3-m·α Among them, F1, F2, and F3 are the load force values ​​collected by three single force sensors respectively; m is the mass of the upper tray in the load test tray assembly; a is the acceleration value collected by the acceleration sensor; The ground load change rate is expressed as a percentage and is calculated as follows: Where: σ——ground load change rate, in %; W——static wheel load, in N; F——wheel load corresponding to the unsprung resonance frequency, in N.

8. A vehicle road ride simulation verification method as claimed in claim 1, characterized in that: The sprung vibration damping ratio and the sprung 6 Hz acceleration peak-to-peak value in step 5.3) include: The sprung vibration damping ratio is calculated by the frequency response function with the unsprung acceleration as input x(t), the sprung acceleration as output y(t), and the suspension system as the transmission system; The unsprung vibration damping ratio is calculated by the frequency response function with the acceleration of the tray as input x(t), the unsprung acceleration as output y(t), and the tire as the transmission system; The unsprung acceleration is the vertical acceleration of the wheel center, and the sprung acceleration is the vertical acceleration of the vehicle body just above the wheel center. For the definition of the frequency response function of the vibration system, x(t) is the system input and y(t) is the system output. The frequency response function of the system is H(f) and can be defined by the following formula: H(f)=X(f) / Y(f) Where: X(f) is the Fourier transform of the system time domain input signal x(t); Y(f) is the Fourier transform of the system time domain output signal y(t); The vibration damping ratio can be calculated according to the frequency response function as follows: Where: η——vibration damping ratio; ω2——The frequency on the right side of the resonant frequency 3dB higher than the resonant frequency, in Hz; ω1——the frequency 3dB below the left side of the resonant frequency, in Hz; ω r ——resonance frequency, in Hz; The peak-to-peak value of the 6 Hz acceleration on the sprung portion is defined as the difference between the highest value and the lowest value of the acceleration signal at each location on the sprung portion within one cycle.

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