Method, system, equipment and medium for evaluating vibration isolation performance of suspension stiffness curve

Abstract

The invention relates to the technical field of simulation, and provides a method, a system, equipment and a medium for evaluating the vibration isolation performance of a suspension stiffness curve, and the method comprises the steps: constructing a whole vehicle dynamic model comprising a dynamic total rigid body sub-module, a suspension sub-module, a vibration noise processing sub-module and other sub-modules; according to the road spectrum target vehicle speed and the current vehicle speed, the target acceleration, the wheel end demand torque and the target rotating speed are calculated, the throttle opening and demand cylinder pressure curve is obtained by combining the wheel end demand torque and the target rotating speed with the universal characteristic curve of the engine, and therefore model motion simulation is stimulated; in simulation, the dynamic total rigid body sub-module obtains suspension active side exciting force according to engine flywheel parameters and obtains suspension reaction force after the suspension sub-module is attenuated, the vibration noise processing module converts sound vibration frequency domain transfer function into time domain transfer function and couples the sound vibration frequency domain transfer function with the suspension reaction force to calculate key point vibration noise in a vehicle, and therefore the vibration isolation performance of the suspension stiffness curve is judged. According to the method, the vibration isolation performance of the suspension stiffness curve can be evaluated.

Description

Technical Field

[0001] The present invention belongs to the field of simulation technology, and in particular relates to a method, system, device and medium for evaluating vibration isolation performance of a suspension stiffness curve. Background Art

[0002] The stiffness curve of a vehicle suspension describes the change in the ability of the suspension to resist deformation when subjected to external force or displacement. It is usually a force-displacement curve, with the horizontal axis being the displacement and the vertical axis being the force. The curve may be nonlinear, for example, it is softer at small displacements and gradually becomes harder as the displacement increases.

[0003] Vibration isolation performance is mainly a measure of the ability of the suspension to prevent vibration from being transmitted from the vibration source to the vehicle body. Good vibration isolation performance can improve the ride comfort of the vehicle, reduce the noise inside the vehicle, and also have a positive impact on the service life of vehicle components because unnecessary vibration shock is reduced. Vibration isolation performance is closely related to the suspension stiffness curve. The appropriate stiffness curve can enable the suspension to play the best vibration isolation role at different vibration frequencies and amplitudes.

[0004] At present, the suspension vibration isolation performance of the whole vehicle is commonly simulated by applying the second-order excitation of the dynamic total mass unit as the spectrum input, the constant frequency stiffness in the bushing CBUSH unit as the suspension vibration isolation unit, and the TB body model as the response system to build a whole vehicle finite element model to simulate the vibration and noise inside the vehicle to evaluate the suspension vibration isolation performance under constant stiffness.

[0005] This method is more suitable for evaluating the influence of the modal and stiffness of the upper body components on the vibration and noise inside the vehicle, but cannot evaluate the vibration isolation performance of the suspension stiffness curve.

[0006] Commonly used power system simulation suspension vibration isolation performance usually builds a 23-DOF multi-body dynamics model of the powertrain, suspension (including stiffness curve), upper body, shock absorber, lower body, and tire, and simulates the suspension stiffness curve vibration isolation performance after inputting the powertrain torque. The disadvantage of this method is that it ignores the torsional vibration excitation of the transmission system, and the error between the actual load of the powertrain and the output torque of the powertrain is large. The suspension stiffness curve vibration isolation simulated by this method is distorted, and the suspension vibration isolation performance cannot be evaluated through the vibration and noise response inside the vehicle.

[0007] In summary, the commonly used vehicle NVH simulation method can evaluate the vibration isolation performance of the suspension under constant stiffness but cannot evaluate the vibration isolation performance of the suspension stiffness curve. The commonly used power system simulation method can simulate the vibration isolation performance of the suspension stiffness curve but has technical problems such as ignoring the torsional vibration excitation of the transmission system, large errors, and being unable to evaluate the vibration isolation performance through the vibration and noise response inside the vehicle. Summary of the invention

[0008] To solve the above problems, the present disclosure provides a method, system, device and medium for evaluating the vibration isolation performance of a suspension stiffness curve, and adopts a simulation method to evaluate the vibration isolation performance of a suspension stiffness curve.

[0009] The following is the technology of the present invention:

[0010] A method for evaluating vibration isolation performance of a suspension stiffness curve, comprising:

[0011] Constructing a whole vehicle dynamics model for performing vehicle motion simulation, wherein the whole vehicle dynamics model includes a dynamic rigid body submodule, a suspension submodule, and a vibration and noise processing module;

[0012] Calculate the target acceleration based on the road spectrum target speed and the current speed of the vehicle; calculate the wheel end required torque based on the target acceleration; and convert the road spectrum target speed into a target speed;

[0013] Based on the wheel end required torque and target speed, the throttle opening required at the next moment is obtained from the universal characteristic curve of the engine, and the required cylinder pressure curve is obtained based on the throttle opening;

[0014] The required cylinder pressure curve is used as the excitation of the vehicle dynamics model to realize the motion simulation of the vehicle dynamics model;

[0015] During the simulation process, the dynamic total rigid body submodule calculates the dynamic total rigid body driving force as the excitation force of the active side of the suspension based on the flywheel torque and angular velocity of the engine. The suspension submodule converts the excitation force of the active side of the suspension into the suspension support reaction force of the passive side of the suspension after the fluctuation attenuation through the suspension stiffness curve; the vibration and noise processing module converts the acoustic vibration frequency domain transmission function from each passive side of the suspension to the vehicle interior into a time domain transmission function, and performs superposition coupling calculation with the suspension support reaction force to obtain the vibration noise of key points in the vehicle;

[0016] The vibration isolation performance of the suspension stiffness curve is determined based on the vibration noise of key points in the vehicle.

[0017] A system for evaluating vibration isolation performance of a suspension stiffness curve, comprising:

[0018] A model building module, used to build a whole vehicle dynamics model for performing motion simulation of the vehicle, wherein the whole vehicle dynamics model includes a dynamic rigid body submodule, a suspension submodule, and a vibration and noise processing module;

[0019] The Driver module is used to calculate the target acceleration based on the vehicle's road spectrum target speed and current speed; calculate the wheel-end required torque based on the target acceleration; and convert the road spectrum target speed into the target speed;

[0020] The engine mapping module Engine Map is used to obtain the throttle opening required at the next moment from the universal characteristic curve of the engine based on the wheel-end required torque and target speed, and obtain the required cylinder pressure curve based on the throttle opening;

[0021] The simulation module is used to use the required cylinder pressure curve as the excitation of the vehicle dynamics model to realize the motion simulation of the vehicle dynamics model;

[0022] During the simulation process, the dynamic total rigid body submodule calculates the dynamic total rigid body driving force as the excitation force of the active side of the suspension based on the flywheel torque and angular velocity of the engine. The suspension submodule converts the excitation force of the active side of the suspension into the suspension support reaction force of the passive side of the suspension after the fluctuation attenuation through the suspension stiffness curve; the vibration and noise processing module converts the acoustic vibration frequency domain transmission function from each passive side of the suspension to the vehicle interior into a time domain transmission function, and performs superposition coupling calculation with the suspension support reaction force to obtain the vibration noise of key points in the vehicle;

[0023] The judging module is used to judge the vibration isolation performance of the suspension stiffness curve based on the vibration noise of key points in the vehicle.

[0024] Further,

[0025] The suspension submodule is a three-dimensional stiffness curve unit at the elastic center point.

[0026] Further,

[0027] The vehicle dynamics model also includes:

[0028] The engine submodule is a multi-body dynamics model of the crankshaft and connecting rod including the piston, connecting rod, crankshaft, and rigid body;

[0029] The clutch submodule is a dynamic model including primary and secondary moments of inertia and torsional stiffness;

[0030] The variable speed transmission submodule is a dynamic model including the speed ratio and equivalent moment of inertia;

[0031] The dynamic assembly rigid body submodule is a rigid body model that includes the moment of inertia and product of inertia of the dynamic assembly and accessory assembly;

[0032] The upper vehicle body submodule is a rigid body model including moment of inertia, product of inertia and mass;

[0033] The lower body submodule is a rigid body model including moment of inertia, product of inertia, and bushing stiffness;

[0034] The shock absorber submodule is a one-way spring unit connecting the upper body mounting point and the lower body mounting point;

[0035] The tire submodule is a magic tire model that includes moment of inertia and stiffness.

[0036] Further,

[0037] The crankshaft of the engine submodule is connected to the clutch submodule via a rotating friction pair;

[0038] The secondary inertia of the clutch submodule is connected to the pre-speed ratio equivalent inertia of the speed change transmission submodule through torsional stiffness;

[0039] The speed transmission submodule is connected to the tire submodule through the half-shaft torsional stiffness and damping to complete the torque and speed transmission, realize the tire rotation and then drive the whole vehicle movement;

[0040] The dynamic total rigid body submodule is connected to the upper vehicle body submodule and the lower vehicle body submodule via the suspension submodule;

[0041] The upper body submodule and the lower body submodule are connected via a shock absorber submodule, and the lower body submodule is connected to a tire submodule.

[0042] Further,

[0043] The demand cylinder pressure curve is used as the excitation of the whole vehicle dynamics model to realize the motion simulation of the whole vehicle dynamics model, including: the dynamics simulation of the whole vehicle road spectrum to the power system rotational motion and the simulation of the whole vehicle motion process driven by the road spectrum.

[0044] Further,

[0045] The dynamics simulation of the vehicle road spectrum to the rotational motion of the power system includes:

[0046] The Driver module outputs the wheel-end required torque based on the road spectrum target speed and the actual speed, and converts the road spectrum target speed into the target speed;

[0047] The engine mapping module Engine Map obtains the throttle opening required at the next moment from the universal characteristic curve of the engine based on the wheel-end required torque and target speed, and obtains the required cylinder pressure curve based on the throttle opening;

[0048] The required cylinder pressure curve is applied to the crank-connecting rod multi-body dynamics model, and the crank-connecting rod multi-body dynamics model outputs the flywheel torque and angular velocity;

[0049] The flywheel torque and angular velocity are input into the transmission submodule after the fluctuation attenuation is completed through the clutch submodule, and then input into the tire submodule after the speed ratio is changed through the transmission submodule, so as to realize the dynamic simulation of the rotational motion of the vehicle road spectrum to the power system.

[0050] Further,

[0051] The road spectrum driving vehicle motion process simulation includes:

[0052] The tire submodule outputs longitudinal driving force and speed to the lower body submodule, the lower body submodule outputs longitudinal driving force and speed to the shock absorber submodule, the shock absorber submodule outputs longitudinal driving force and speed to the upper body submodule, and the upper body submodule outputs the current vehicle speed to the Driver module; realizing the simulation of the road spectrum driven vehicle movement process.

[0053] Compared with the prior art, the present invention has the following advantages:

[0054] The present invention is no longer limited to simplifying the suspension to a constant stiffness under a constant driving force for simulation, but based on the road spectrum target speed and the current speed, accurately calculates the target acceleration, wheel end required torque and target speed, and combines the engine universal characteristic curve to derive the dynamically changing throttle opening and required cylinder pressure curve, which is used as an excitation to drive the whole vehicle dynamics model motion simulation;

[0055] During the simulation, the dynamic total rigid body submodule calculates the dynamic total rigid body driving force as the active side excitation force of the suspension in real time according to the flywheel torque and angular velocity of the engine, and the suspension submodule performs fluctuation attenuation on the excitation force according to the suspension stiffness curve, thereby accurately simulating the dynamic changes of the suspension stiffness under different working conditions;

[0056] This method enables the simulation results to more realistically reflect the vibration isolation performance of the suspension stiffness curve under the actual operating state of the vehicle. Compared with the traditional simulation method of inputting spectrum excitation and simplifying the suspension to a constant driving force constant stiffness, it greatly improves the accuracy of evaluating the vibration isolation performance of the stiffness curve, and provides a more reliable basis for the optimal design and performance improvement of the vehicle suspension system.

[0057] Other features and advantages of the present disclosure will be described in the following description, and partly become apparent from the description, or be understood by implementing the present disclosure. The purpose and other advantages of the present disclosure can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0059] Figure 1 A schematic diagram of the method of the present invention is shown;

[0060] Figure 2 A schematic diagram of the simulation process of the method of the present invention is shown. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0062] Figure 1 A schematic diagram of the method according to the present invention is shown, and the specific implementation details of the present invention include:

[0063] 1. Step 1: Build a driver module. The driver module is used to calculate the target acceleration based on the vehicle's road spectrum target speed and current speed; calculate the wheel-end required torque based on the target acceleration; and convert the road spectrum target speed into the target speed.

[0064] 2. Step 2: Build the engine map module, and input the engine universal characteristic curve and the cylinder pressure map of different throttle openings into the engine map module;

[0065] After inputting the wheel-end torque and the current speed into the engine map, the target throttle opening information is obtained according to the universal characteristic curve; the cylinder pressure curve of the target throttle opening is obtained by interpolating the cylinder pressure curve corresponding to the existing throttle opening, and is input into the vehicle multi-body dynamics model.

[0066] 3. Step 3: Build the vehicle multi-body dynamics module, which includes:

[0067] Engine submodule: Contains piston, connecting rod, crankshaft, and rigid body crank-connecting rod multi-body dynamics model;

[0068] Clutch submodule: contains the dynamic models of primary and secondary moments of inertia and torsional stiffness;

[0069] Variable speed transmission submodule: contains the dynamic model of speed ratio and equivalent moment of inertia;

[0070] Suspension submodule: Simplify the stiffness curve model at the elastic center point;

[0071] Dynamic assembly rigid body submodule: contains the rigid body model of the dynamic assembly and accessory assembly moment of inertia and product of inertia;

[0072] Upper body submodule: rigid body model including moment of inertia / product and mass;

[0073] Shock absorber submodule: simplified one-way spring unit connecting upper and lower mounting points;

[0074] Lower body submodule: a rigid body model including moment of inertia, product of inertia, and bushing stiffness;

[0075] Tire submodule: contains the magic tire model of moment of inertia and stiffness;

[0076] The remaining submodules.

[0077] 4. Step 4: Connect the modules of the vehicle multibody dynamics model, including:

[0078] The crankshaft is discretized into the optical shaft, crank pin, connecting rod pin and other rigid bodies with different moments of inertia by analytical method, which are connected to each other through torsional stiffness;

[0079] The clutch is simplified to a primary and secondary inertia and torsional stiffness unit connecting the crankshaft and the transmission;

[0080] The transmission module of the transmission is simplified to the equivalent inertia before the speed ratio, the torsional stiffness connects the secondary inertia of the clutch and the tire assembly, and the tire assembly is connected to the lower body;

[0081] The upper and lower car bodies are connected by shock absorbers;

[0082] Rotating parts such as the crankshaft and transmission are connected to the dynamic rigid body assembly through a rotating friction pair; the dynamic rigid body is connected to the upper and lower vehicle bodies through a suspension, thereby completing the connection of the multi-body dynamics model of the whole vehicle.

[0083] 5. Step 5: Enter the road spectrum (vehicle speed-time curve), rolling resistance curve, frontal area, drag coefficient, vehicle mass and other parameters in the driver module.

[0084] The driver module is based on the road spectrum target speed and the model's current speed. After taking the difference between the road spectrum target speed and the model's current speed (the output of the vehicle dynamics model), the vehicle's target acceleration is obtained by differentiation. The vehicle's longitudinal acceleration is input into the vehicle dynamics model to obtain the wheel-end required torque, and the target speed is obtained by speed ratio conversion.

[0085] The driver module outputs wheel-end torque and target speed information.

[0086] After inputting the required wheel-end torque and the current vehicle speed into the engine map module, the required throttle opening can be obtained, and the throttle opening is mapped to the cylinder pressure curve; thereby, the road spectrum is converted into a cylinder pressure curve to drive the piston-connecting rod group to operate. The reciprocating operation of the piston-connecting rod group drives the tires through the crankshaft flywheel and the transmission drive unit to realize the longitudinal movement of the vehicle.

[0087] Under the whole vehicle operation condition of Lupu drive, rotating parts such as crankshaft and transmission gear shaft transmit torque and speed to the dynamic assembly rigid body and suspension through rotating friction pairs, which correspond to the suspension driving force and support reaction force, thereby realizing the acquisition of support reaction force after vibration isolation of the suspension stiffness curve under Lupu drive condition.

[0088] 6. Step 6: Construct the vibration and noise processing (post proceed) module.

[0089] The module inputs the acoustic-vibration frequency domain transfer function from the passive side of the suspension to the vehicle body. The acoustic-vibration frequency domain transfer function is converted into a time domain transfer function after Fourier transform, and is coupled with the time domain support reaction force output by the suspension module to output vibration noise.

[0090] 7. Step 7: During the simulation process, the input road spectrum, suspension stiffness curve, and structural transfer function can be adjusted to output the in-vehicle noise response under different working conditions. Based on the vibration noise at key points in the vehicle, the vibration isolation performance of the suspension stiffness curve under different working conditions or the contribution ratio of the structural transfer function and the suspension stiffness curve to the in-vehicle vibration noise can be evaluated.

[0091] The following are specific examples of the present invention. Figure 2 As shown, including:

[0092] This simulation method mainly uses the road spectrum to simulate driving needs. The vehicle acceleration is calculated by differentiating the difference between the target speed at the next moment and the current speed. The acceleration is converted into the required wheel-end torque according to the vehicle longitudinal dynamics formula. The target speed and the current speed are combined with the gear ratio to convert them into the target speed and the current speed. The specific implementation is as follows:

[0093] Input the wheel end required torque and current / target speed signal calculated in step 1 into the engine universal characteristic curve in the Engine Map module to obtain the throttle opening required at the next moment, and use the throttle opening as the basis for the piston to withstand cylinder pressure excitation;

[0094] Apply the cylinder pressure curve obtained in step 2 to the simplified piston connecting rod and crankshaft flywheel dynamics model of the engine in the engine submodule to simulate the actual operation process of the powertrain during real vehicle driving. The cylinder pressure curve is converted into flywheel torque and angular velocity through the piston connecting rod and crankshaft flywheel dynamics model;

[0095] After the road spectrum is converted into engine output torque and angular velocity through step 3, it is input into the tire after the clutch completes the fluctuation attenuation and the transmission completes the speed ratio change, completing the dynamic simulation of the vehicle road spectrum to the rotational motion of the power system.

[0096] The torque and angular velocity obtained in step 4 are converted into longitudinal driving force and speed through the tire sub-module, and the longitudinal movement of the whole vehicle is completed through the lower body, shock absorber, and upper body, completing the road spectrum driven vehicle movement process.

[0097] The torque, angular velocity, etc. calculated in steps 1-5 are input to the dynamic total rigid body assembly through the rotating friction pair, and then the dynamic total rigid body driving force is calculated, which is the resultant force of the excitation force on the active side of the suspension; the excitation force on the active side of the suspension obtained in step 6 is converted into the suspension support reaction force on the passive side of the suspension after the suspension stiffness curve completes the fluctuation attenuation, thereby completing the vibration isolation performance simulation of the suspension stiffness curve.

[0098] The acoustic vibration frequency domain transfer function from the passive side of each suspension to the vehicle interior is converted into a time domain transfer function, and superimposed and coupled with the reaction force of each suspension support obtained by simulation in step 7 to obtain the vibration and noise of key points in the vehicle, thus completing the vibration and noise simulation of key points in the vehicle during the road spectrum driving process.

[0099] The following are advantages of the present invention:

[0100] 1) The actual driving conditions are simulated through the road spectrum, and the road spectrum is converted into the cylinder pressure curve required for engine operation, so as to realize the load simulation of each system under the operating conditions, and then the vehicle dynamics simulation under different driving conditions is completed by changing the road spectrum, which has good applicability;

[0101] 2) Considering the vibration isolation performance of the dynamic change of the suspension stiffness under different dynamic total displacements caused by the change of the vehicle driving force, compared with the simulation method of inputting spectrum excitation and simplifying the suspension to a constant stiffness under constant driving force, this simulation method is more in line with the actual operating state of the vehicle and has a higher accuracy in evaluating the vibration isolation performance of the stiffness curve;

[0102] 3) The vibration and noise processing module is integrated into the multi-body dynamics simulation model of the whole vehicle. The acoustic vibration frequency domain transfer function of the passive side structure path is converted into a time domain transfer function and then coupled with the excitation to obtain the vibration and noise of key points in the vehicle. The vibration and noise response in the vehicle is used as the evaluation criterion for the suspension vibration isolation performance.

[0103] Based on the method of the present invention, the embodiment of the present disclosure also provides a system corresponding to the above method, which includes:

[0104] A model building module, used to build a whole vehicle dynamics model for performing motion simulation of the vehicle, wherein the whole vehicle dynamics model includes a dynamic rigid body submodule, a suspension submodule, and a vibration and noise processing module;

[0105] The Driver module is used to calculate the target acceleration based on the vehicle's road spectrum target speed and current speed; calculate the wheel-end required torque based on the target acceleration; and convert the road spectrum target speed into the target speed;

[0106] The engine mapping module Engine Map is used to obtain the throttle opening required at the next moment from the universal characteristic curve of the engine based on the wheel-end required torque and target speed, and obtain the required cylinder pressure curve based on the throttle opening;

[0107] The simulation module is used to use the required cylinder pressure curve as the excitation of the vehicle dynamics model to realize the motion simulation of the vehicle dynamics model;

[0108] During the simulation process, the dynamic total rigid body submodule calculates the dynamic total rigid body driving force as the excitation force of the active side of the suspension based on the flywheel torque and angular velocity of the engine. The suspension submodule converts the excitation force of the active side of the suspension into the suspension support reaction force of the passive side of the suspension after the fluctuation attenuation through the suspension stiffness curve; the vibration and noise processing module converts the acoustic vibration frequency domain transmission function from each passive side of the suspension to the vehicle interior into a time domain transmission function, and performs superposition coupling calculation with the suspension support reaction force to obtain the vibration noise of key points in the vehicle;

[0109] The judging module is used to judge the vibration isolation performance of the suspension stiffness curve based on the vibration noise of key points in the vehicle.

[0110] Based on the same inventive concept as the above disclosed content, an embodiment of the present disclosure also provides a prediction device corresponding to the above method, which includes at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the above method.

[0111] It should be noted that the electrical connection between the above-mentioned units does not necessarily mean the connection between lines. An indirect connection method can be applied to the embodiments of the present disclosure as long as the purpose of the present disclosure is achieved.

[0112] Based on the same inventive concept, the present disclosure also provides a computer storage medium on which executable instructions are stored. When the instructions are executed by a processor, the processor performs the above method.

[0113] Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A method for evaluating the vibration isolation performance of a suspension stiffness curve, characterized in that: include: Constructing a whole vehicle dynamics model for performing vehicle motion simulation, wherein the whole vehicle dynamics model includes a dynamic rigid body submodule, a suspension submodule, and a vibration and noise processing module; Calculate the target acceleration based on the vehicle's road spectrum target speed and current speed; Calculate the required wheel end torque based on the target acceleration; And convert the road spectrum target vehicle speed into a target speed; Based on the wheel end required torque and target speed, the throttle opening required at the next moment is obtained from the universal characteristic curve of the engine, and the required cylinder pressure curve is obtained based on the throttle opening; The required cylinder pressure curve is used as the excitation of the vehicle dynamics model to realize the motion simulation of the vehicle dynamics model; During the simulation process, the dynamic total rigid body submodule calculates the dynamic total rigid body driving force as the excitation force of the active side of the suspension based on the flywheel torque and angular velocity of the engine. The suspension submodule converts the excitation force of the active side of the suspension into the suspension support reaction force of the passive side of the suspension after the fluctuation attenuation through the suspension stiffness curve; the vibration and noise processing module converts the acoustic vibration frequency domain transmission function from each passive side of the suspension to the vehicle interior into a time domain transmission function, and performs superposition coupling calculation with the suspension support reaction force to obtain the vibration noise of key points in the vehicle; The vibration isolation performance of the suspension stiffness curve is determined based on the vibration noise of key points in the vehicle.

2. A system for evaluating the vibration isolation performance of a suspension stiffness curve, characterized in that: include: A model building module, used to build a whole vehicle dynamics model for performing motion simulation of the vehicle, wherein the whole vehicle dynamics model includes a dynamic rigid body submodule, a suspension submodule, and a vibration and noise processing module; Driver module, used to calculate the target acceleration based on the vehicle's road spectrum target speed and current speed; Calculate the required wheel end torque based on the target acceleration; And convert the road spectrum target vehicle speed into a target speed; The engine mapping module Engine Map is used to obtain the throttle opening required at the next moment from the universal characteristic curve of the engine based on the wheel-end required torque and target speed, and obtain the required cylinder pressure curve based on the throttle opening; The simulation module is used to use the required cylinder pressure curve as the excitation of the whole vehicle dynamics model to realize the motion simulation of the whole vehicle dynamics model; during the simulation process, the dynamic total rigid body submodule calculates the dynamic total rigid body driving force as the excitation force of the active side of the suspension based on the flywheel torque and angular velocity of the engine, and the suspension submodule converts the excitation force of the active side of the suspension into the suspension support reaction force of the passive side of the suspension after the fluctuation attenuation through the suspension stiffness curve; the vibration and noise processing module converts the acoustic vibration frequency domain transmission function from each passive side of the suspension to the vehicle interior into a time domain transmission function, and performs superposition coupling calculation with the suspension support reaction force to obtain the vibration noise of key points in the vehicle; The judging module is used to judge the vibration isolation performance of the suspension stiffness curve based on the vibration noise of key points in the vehicle.

3. A system for evaluating vibration isolation performance of a suspension stiffness curve according to claim 2, characterized in that: The suspension submodule is a three-dimensional stiffness curve unit at the elastic center point.

4. A system for evaluating vibration isolation performance of a suspension stiffness curve according to claim 3, characterized in that: The vehicle dynamics model also includes: The engine submodule is a multi-body dynamics model of the crankshaft and connecting rod including the piston, connecting rod, crankshaft, and rigid body; The clutch submodule is a dynamic model including primary and secondary moments of inertia and torsional stiffness; The variable speed transmission submodule is a dynamic model including the speed ratio and equivalent moment of inertia; The dynamic assembly rigid body submodule is a rigid body model that includes the moment of inertia and product of inertia of the dynamic assembly and accessory assembly; The upper vehicle body submodule is a rigid body model including moment of inertia, product of inertia and mass; The lower body submodule is a rigid body model including moment of inertia, product of inertia, and bushing stiffness; The shock absorber submodule is a one-way spring unit connecting the upper body mounting point and the lower body mounting point; The tire submodule is a magic tire model that includes moment of inertia and stiffness.

5. A system for evaluating vibration isolation performance of a suspension stiffness curve according to claim 4, characterized in that: The crankshaft of the engine submodule is connected to the clutch submodule via a rotating friction pair; The secondary inertia of the clutch submodule is connected to the pre-speed ratio equivalent inertia of the speed change transmission submodule through torsional stiffness; The speed transmission submodule is connected to the tire submodule through the half-shaft torsional stiffness and damping to complete the torque and speed transmission, realize the tire rotation and then drive the whole vehicle movement; The dynamic total rigid body submodule is connected to the upper vehicle body submodule and the lower vehicle body submodule via the suspension submodule; The upper body submodule and the lower body submodule are connected via a shock absorber submodule, and the lower body submodule is connected to a tire submodule.

6. A system for evaluating vibration isolation performance of a suspension stiffness curve according to claim 5, characterized in that: The demand cylinder pressure curve is used as the excitation of the whole vehicle dynamics model to realize the motion simulation of the whole vehicle dynamics model, including: the dynamics simulation of the whole vehicle road spectrum to the power system rotational motion and the simulation of the whole vehicle motion process driven by the road spectrum.

7. A system for evaluating vibration isolation performance of a suspension stiffness curve according to claim 6, characterized in that: The dynamics simulation of the vehicle road spectrum to the rotational motion of the power system includes: The Driver module outputs the wheel-end required torque based on the road spectrum target speed and the actual speed, and converts the road spectrum target speed into the target speed; The engine mapping module Engine Map obtains the throttle opening required at the next moment from the universal characteristic curve of the engine based on the wheel-end required torque and target speed, and obtains the required cylinder pressure curve based on the throttle opening; The required cylinder pressure curve is applied to the crank-connecting rod multi-body dynamics model, and the crank-connecting rod multi-body dynamics model outputs the flywheel torque and angular velocity; The flywheel torque and angular velocity are input into the transmission submodule after the fluctuation attenuation is completed through the clutch submodule, and then input into the tire submodule after the speed ratio is changed through the transmission submodule, so as to realize the dynamic simulation of the rotational motion of the vehicle road spectrum to the power system.

8. A system for evaluating vibration isolation performance of a suspension stiffness curve according to claim 7, characterized in that: The road spectrum driving vehicle motion process simulation includes: The tire submodule outputs longitudinal driving force and speed to the lower body submodule, the lower body submodule outputs longitudinal driving force and speed to the shock absorber submodule, the shock absorber submodule outputs longitudinal driving force and speed to the upper body submodule, and the upper body submodule outputs the current vehicle speed to the Driver module; realizing the simulation of the road spectrum driven vehicle movement process.

9. A device for evaluating the vibration isolation performance of a suspension stiffness curve, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor so that the at least one processor can execute the method for evaluating the vibration isolation performance of the suspension stiffness curve as described in claim 1.

10. A computer storage medium having executable instructions stored thereon, wherein when the instructions are executed by a processor, the processor is enabled to implement the method of claim 1.

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