Methods, systems, devices, and media to assess isolation performance of suspension stiffness curves

Abstract

The present disclosure relates to the field of simulation technology, and provides a method, system, device and medium for evaluating isolation performance of a suspension stiffness curve, the method comprising: constructing a whole vehicle dynamics model comprising a moving total rigid body, a suspension, a vibration and noise processing and the like sub-modules; calculating a target acceleration, a wheel end required torque and a target speed according to a road spectrum target vehicle speed and a current vehicle speed, obtaining a throttle opening degree and a required cylinder pressure curve from the wheel end required torque and the target speed in combination with an engine universal characteristic curve, and exciting model motion simulation; in the simulation, the moving total rigid body sub-module obtains a suspension active side excitation force according to an engine flywheel parameter, the suspension sub-module obtains a suspension support reaction force after attenuation, and the vibration and noise processing module couples the sound and vibration frequency domain transfer function to the time domain transfer function and the suspension support reaction force to calculate the vibration and noise of key points in the vehicle, so as to judge the isolation performance of the suspension stiffness curve. The method can evaluate the isolation performance of the suspension stiffness curve.

Description

TECHNICAL FIELD

[0001] The present disclosure belongs to the technical field of simulation, and particularly relates to a method, system, device and medium for evaluating isolation performance of a suspension stiffness curve. BACKGROUND

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

[0003] Isolation performance is mainly a measure of the ability of the suspension to prevent vibration from the vibration source from being transmitted to the vehicle body. Good isolation performance can improve the ride comfort of the vehicle, reduce the noise in the vehicle, and also has a positive impact on the service life of vehicle components, as unnecessary vibration impact is reduced. Isolation performance is closely related to the suspension stiffness curve, and a suitable stiffness curve can enable the suspension to achieve optimal isolation performance at different vibration frequencies and amplitudes.

[0004] Currently, the suspension isolation performance is simulated by whole vehicle NVH simulation. A whole vehicle finite element model is constructed, with the dynamic total mass unit applying 2nd order excitation as the frequency spectrum input, the constant frequency stiffness in the bush CBUSH unit as the suspension isolation unit, and the TB vehicle body model as the response system, to simulate the in-vehicle vibration noise and evaluate the suspension isolation performance under constant stiffness.

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

[0006] The suspension isolation performance is commonly simulated by a powertrain system, which usually constructs a 23-degree-of-freedom multi-body dynamics model of the dynamic total, suspension (including stiffness curve), upper vehicle body, damper, lower vehicle body, and tire, and simulates the suspension stiffness curve isolation performance after inputting the dynamic total torque. The disadvantage of this method is that it ignores the torsional vibration excitation of the transmission system, the actual load of the dynamic total and the output torque of the dynamic total have a large error, the suspension stiffness curve isolation performance simulated by this method is distorted, and the suspension isolation performance cannot be evaluated by the in-vehicle vibration noise response.

[0007] In summary, the commonly used whole vehicle NVH simulation method can evaluate the suspension isolation performance under constant stiffness, but cannot evaluate the isolation performance of the suspension stiffness curve. The commonly used powertrain system simulation method can simulate the suspension stiffness curve isolation performance, but has technical problems such as ignoring the torsional vibration excitation of the transmission system, having a large error, and being unable to evaluate the isolation performance by the in-vehicle vibration noise response. SUMMARY

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

[0009] The following is the present technology:

[0010] A method for evaluating the isolation performance of a suspension stiffness curve, characterized in that it comprises:

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

[0012] Based on the target speed and the current speed of the vehicle, the target acceleration is calculated; based on the target acceleration, the wheel end demand torque is calculated; and the target speed is converted into a target speed;

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

[0014] Using the demand cylinder pressure curve as the excitation of the whole vehicle dynamics model, the motion simulation of the whole vehicle dynamics model is realized;

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

[0016] Based on the vibration and noise of the key points in the vehicle, the isolation performance of the suspension stiffness curve is judged.

[0017] A system for evaluating the isolation performance of a suspension stiffness curve, characterized in that it comprises:

[0018] A model construction module for constructing a whole vehicle dynamics model for motion simulation of the vehicle, which includes a dynamic total rigid body submodule, a suspension submodule, and a vibration and noise processing module;

[0019] A Driver module for calculating the target acceleration based on the target speed and the current speed of the vehicle; calculating the wheel end demand torque based on the target acceleration; and converting the target speed into a target speed;

[0020] An engine mapping module Engine Map is configured to obtain a throttle opening required at a next time from a universal characteristic curve of an engine based on a wheel end required torque and a target rotating speed, and obtain a required cylinder pressure curve based on the throttle opening;

[0021] A simulation module is configured to realize motion simulation of a vehicle dynamics model by using the required cylinder pressure curve as an excitation of the vehicle dynamics model;

[0022] During the simulation, the dynamic total rigid body submodule calculates a dynamic total rigid body driving force based on a flywheel torque and an angular velocity of the engine, and the dynamic total rigid body driving force is taken as an excitation force on a driving side of a mount, the mount submodule converts the excitation force on the driving side of the mount into a mount reaction force on a passive side of the mount after the excitation force on the driving side of the mount is attenuated by a mount stiffness curve, and the vibration and noise processing module converts a sound and vibration frequency domain transfer function from each passive side of the mount to a vehicle interior into a time domain transfer function, and performs superposition and coupling calculation on the mount reaction force on the passive side of the mount and the time domain transfer function to obtain vibration and noise at key points in the vehicle interior.

[0023] A judgment module is configured to judge isolation performance of the mount stiffness curve based on the vibration and noise at the key points in the vehicle interior.

[0024] Further,

[0025] The mount submodule is a three-way stiffness curve unit at a center point of elasticity.

[0026] Further,

[0027] The vehicle dynamics model further comprises:

[0028] An engine submodule is a crankshaft connecting rod multi-body dynamics model comprising a piston, a connecting rod, a crankshaft and a rigid body;

[0029] A clutch submodule is a dynamics model comprising primary and secondary rotating inertia and torsional stiffness;

[0030] A transmission submodule is a dynamics model comprising a speed ratio and an equivalent rotating inertia;

[0031] A dynamic total rigid body submodule is a rigid body model comprising inertia moments and inertia products of a dynamic total and an accessory assembly;

[0032] An upper vehicle body submodule is a rigid body model comprising inertia moments, inertia products and mass;

[0033] A lower vehicle body submodule is a rigid body model comprising inertia moments, inertia products and bush stiffness;

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

[0035] A tire submodule is a magic tire model comprising rotating inertia and stiffness.

[0036] Further,

[0037] The crankshaft of the engine sub-module is connected with the clutch sub-module through a rotating friction pair;

[0038] The secondary inertia of the clutch sub-module is connected with the equivalent inertia before the speed ratio of the transmission sub-module through torsional stiffness;

[0039] The transmission sub-module is connected with the tire sub-module through the torsional stiffness and damping of the half shaft, so as to complete torque and speed transmission, realize tire rotation and further drive the vehicle movement;

[0040] The dynamic rigid body sub-module is connected on the upper vehicle body sub-module and the lower vehicle body sub-module through the suspension sub-module;

[0041] The upper vehicle body sub-module and the lower vehicle body sub-module are connected through the shock absorber sub-module, and the lower vehicle body sub-module is connected with the tire sub-module.

[0042] Further,

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

[0044] Further,

[0045] The dynamics simulation of vehicle road spectrum to power system rotation; including:

[0046] The Driver module outputs the wheel end demand torque based on the road spectrum target speed and the actual vehicle speed; and converts the road spectrum target speed into a target speed;

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

[0048] The demand cylinder pressure curve is applied to the crankshaft and connecting rod multi-body dynamics model, and the crankshaft and 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 sub-module after completing the fluctuation attenuation through the clutch sub-module, and are input into the tire sub-module after completing the speed ratio conversion through the transmission sub-module, so as to realize the dynamics simulation of vehicle road spectrum to power system rotation.

[0050] Further,

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

[0052] The tire sub-module outputs longitudinal driving force and speed to the lower vehicle body sub-module, the lower vehicle body sub-module outputs longitudinal driving force and speed to the shock absorber sub-module, the shock absorber sub-module outputs longitudinal driving force and speed to the upper vehicle body sub-module, and the upper vehicle body sub-module outputs current vehicle speed to the Driver module; and road spectrum driving whole vehicle motion process simulation is realized.

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

[0054] The present application is no longer limited to simplifying the suspension to constant driving force and constant stiffness for simulation, but based on the road spectrum target vehicle speed and the current vehicle speed, the target acceleration, the wheel end required torque and the target rotating speed are accurately calculated, and the dynamically changing throttle opening and required cylinder pressure curves are obtained in combination with the engine universal characteristic curve, which are used as excitation driving whole vehicle dynamics model motion simulation;

[0055] In the simulation process, the dynamic total rigid body sub-module calculates the dynamic total rigid body driving force in real time according to the flywheel torque and angular velocity of the engine as the suspension active side excitation force, and the suspension sub-module attenuates the excitation force according to the suspension stiffness curve, so as to accurately simulate the dynamic change of the suspension stiffness under different working conditions;

[0056] This way makes the simulation results more truly reflect the vibration isolation performance of the suspension stiffness curve under the actual running state of the whole vehicle, compared with the traditional input frequency spectrum excitation and the simulation method of simplifying the suspension to constant driving force and constant stiffness, the precision of evaluating the vibration isolation performance of the stiffness curve is greatly improved, which provides a more reliable basis for the optimization design and performance improvement of the vehicle suspension system.

[0057] Other features and advantages of the present disclosure will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present disclosure. The objects and other advantages of the present disclosure can be realized and obtained by the structures indicated in the specification, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are some embodiments of the present disclosure, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0059] Figure 1 The present application method schematic diagram is shown;

[0060] Figure 2 The present application method simulation process schematic diagram is shown. DETAILED DESCRIPTION

[0061] The technical solutions and advantages of the embodiments of the present disclosure will be more clearly understood from the following description of the embodiments of the present disclosure with reference to the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present disclosure.

[0062] Figure 1 The specific implementation details of the present application are shown in the schematic diagram of the method according to the present application, which include:

[0063] 1. Step one: build a driver module, which is used to calculate target acceleration based on the target vehicle speed of the road profile and the current vehicle speed, calculate the wheel end demand torque based on the target acceleration, and convert the target speed of the road profile into the target speed.

[0064] 2. Step two: build an engine map module, in which the engine universal characteristic curve and the cylinder pressure map of different throttle openings are input.

[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 interpolation calculation of the existing throttle opening corresponding cylinder pressure curve, and is input into the whole vehicle multi-body dynamics model.

[0066] 3. Step three: build a whole vehicle multi-body dynamics module, which includes:

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

[0068] Clutch submodule: including the dynamics model of primary and secondary rotational inertia and torsional stiffness;

[0069] Gear transmission submodule: including the dynamics model of gear ratio and equivalent rotational inertia;

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

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

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

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

[0074] Lower body sub-module: rigid body model including inertia moment, inertia product, bushing stiffness;

[0075] Tire sub-module: magic tire model including rotational inertia, stiffness;

[0076] The rest of the sub-modules.

[0077] 4. Step four: connecting each module of the whole vehicle multi-body dynamics model, including:

[0078] The crankshaft is discretized into different rotational inertia rigid bodies such as the main shaft, crank pin, and connecting rod pin, which are connected to each other through torsional stiffness;

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

[0080] The transmission drive module is simplified as a speed ratio front equivalent inertia and torsional stiffness connecting the clutch secondary inertia and the tire assembly, and the tire assembly is connected to the lower body;

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

[0082] The crankshaft and transmission drive rotating parts are connected to the dynamic total rigid body assembly through rotating friction pairs; the dynamic total rigid body is connected to the upper and lower bodies through suspension, thus completing the connection of the whole vehicle multi-body dynamics model.

[0083] 5. Step five: inputting road profile (vehicle speed-time curve), rolling resistance curve, wind area, wind resistance coefficient, and whole vehicle mass into the driver module.

[0084] The driver module obtains the vehicle target acceleration by differentiating the difference between the road profile target speed and the model current speed (whole vehicle dynamics model output); the vehicle longitudinal acceleration is input into the whole vehicle dynamics model to obtain the wheel end demand torque, and the target speed is converted into target speed through the speed ratio to obtain the target speed.

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

[0086] After inputting the wheel end demand torque and the current speed of the whole vehicle into the engine map module, the demand throttle opening can be obtained, and the throttle opening maps the cylinder pressure curve; thus, the road profile is converted into a cylinder pressure curve to drive the piston connecting rod group to operate, and the reciprocating operation of the piston connecting rod group drives the tire through the crankshaft flywheel and transmission drive unit to realize the longitudinal motion of the whole vehicle.

[0087] Under the road profile driving whole vehicle operating condition, the rotating parts such as the crankshaft and transmission shaft transmit the torque and speed to the dynamic total rigid body and suspension through rotating friction pairs, i.e. the suspension driving force and reaction force, thus realizing the acquisition of the suspension stiffness curve vibration isolation reaction force under the road profile driving condition.

[0088] 6、Step six: build vibration noise processing (post proceed) module.

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

[0090] 7、Step seven: in the simulation process, the input road spectrum, suspension stiffness curve, and structure transfer function can be adjusted to output the vehicle interior noise response under different working conditions, and the vibration noise evaluation of the key points in the vehicle under different working conditions is based on the vibration noise evaluation of the key points in the vehicle under different working conditions. The contribution ratio of the structure transfer function and the suspension stiffness curve to the vibration noise in the vehicle.

[0091] The following is a specific example of the present application, as shown in Figure 2 , including:

[0092] The simulation method mainly simulates the driving demand by differentiating the difference between the target vehicle speed and the current vehicle speed, and converts the whole vehicle acceleration into the wheel end demand torque according to the whole vehicle longitudinal dynamics formula. The target speed and the current speed are converted into target speed and current speed by combining the gear ratio. The specific implementation is as follows:

[0093] The wheel end demand torque and current / target speed signals calculated in step 1 are input into the Engine Map module to obtain the engine universal characteristic curve, and the throttle opening degree is obtained as the piston bearing cylinder pressure excitation credential;

[0094] The cylinder pressure curve obtained in step 2 is applied to the simplified piston connecting rod, crankshaft flywheel dynamics model in the engine sub-module 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 by the piston connecting rod, crankshaft flywheel dynamics model;

[0095] After the road spectrum is converted into engine output torque and angular velocity in step 3, the clutch completes the fluctuation attenuation, the transmission completes the speed ratio conversion, and the tire is input, completing the dynamics simulation of the whole vehicle road spectrum to the power system rotation.

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

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

[0098] The sound and vibration frequency domain transfer functions of each passive side of the suspension to the vehicle interior are converted into time domain transfer functions, and are superimposed and coupled with the suspension support reaction force obtained in step 7 to obtain the vibration noise of the key points in the vehicle interior, and the simulation of the vibration noise of the key points in the vehicle interior in the process of the road spectrum driving of the whole vehicle is completed.

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

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

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

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

[0103] Based on the method of the present application, the disclosure also provides a system corresponding to the above-mentioned method, which comprises:

[0104] A model construction module is configured to construct a whole vehicle dynamics model for simulating the motion of a vehicle, wherein the whole vehicle dynamics model comprises a dynamic total rigid body sub-module, a suspension sub-module and a vibration noise processing module;

[0105] A Driver module is configured to calculate a target acceleration based on a target vehicle speed and a current vehicle speed of the vehicle, calculate a wheel end required torque based on the target acceleration, and convert the target vehicle speed into a target speed;

[0106] An engine mapping module Engine Map is configured to obtain a throttle opening degree required at the next time from a universal characteristic curve of an engine based on the wheel end required torque and the target speed, and obtain a required cylinder pressure curve based on the throttle opening degree;

[0107] An emulation module is configured to realize motion emulation of the whole vehicle dynamics model by using the demand cylinder pressure curve as an excitation of the whole vehicle dynamics model.

[0108] During the emulation process, the dynamic total rigid body submodule calculates a dynamic total rigid body driving force based on the flywheel torque and angular velocity of the engine as an excitation force of the active side of the suspension, the suspension submodule converts the excitation force of the active side of the suspension into a suspension support reaction force of the passive side of the suspension after the excitation force is attenuated by a suspension stiffness curve, and the vibration and noise processing module converts the sound and vibration frequency domain transfer function from the passive side of the suspension to the vehicle interior into a time domain transfer function, and performs superposition and coupling calculation with the suspension support reaction force to obtain the vibration and noise of the key points in the vehicle.

[0109] A judgment module is configured to judge the vibration isolation performance of the suspension stiffness curve based on the vibration and noise of the key points in the vehicle.

[0110] Based on the same inventive concept disclosed above, the embodiments of the present disclosure further provide a prediction device corresponding to the above method, which comprises at least one processor; and a memory connected in communication with the at least one processor; wherein the memory stores instructions executable 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 perform the above method.

[0111] It should be noted that the electrical connection between the above-mentioned units does not necessarily mean the connection between the lines, and the indirect connection mode can also be applicable 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 further provides a computer storage medium having executable instructions stored thereon, which are executed by a processor to enable the processor to perform the above method.

[0113] Although the present disclosure has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalent features; and such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A method of evaluating the performance of a suspension stiffness curve isolation, characterized in that, The method comprises the following steps: constructing a whole vehicle dynamics model for motion simulation of the vehicle, the whole vehicle dynamics model comprising a dynamic total rigid body submodule, a suspension submodule, and a vibration and noise processing module; calculating a target acceleration based on a road spectrum target speed and a current speed of the vehicle; calculating a wheel end required torque based on the target acceleration; and converting the road spectrum target speed into a target speed; obtaining a next moment required throttle opening degree from a universal characteristic curve of the engine based on the wheel end required torque and the target speed, and obtaining a required cylinder pressure curve based on the throttle opening degree; using the required cylinder pressure curve as an excitation of the whole vehicle dynamics model to realize motion simulation of the whole vehicle dynamics model; in the simulation process, the dynamic total rigid body submodule calculates a dynamic total rigid body driving force based on a flywheel torque and an angular velocity of the engine as a suspension active side excitation force, the suspension submodule converts the suspension active side excitation force into suspension support reaction forces of suspension passive sides after wave attenuation of the suspension stiffness curve, and the vibration and noise processing module converts sound and vibration frequency domain transfer functions from the suspension passive sides to the vehicle interior into time domain transfer functions, and performs superposition and coupling calculation with the suspension support reaction forces to obtain vibration and noise of key points in the vehicle interior; judging isolation performance of the suspension stiffness curve based on the vibration and noise of the key points in the vehicle interior.

2. A system for evaluating the performance of a suspension stiffness curve isolation, characterized in that, The method comprises the following steps: a model construction module for constructing a whole vehicle dynamics model for motion simulation of the vehicle, the whole vehicle dynamics model comprising a dynamic total rigid body submodule, a suspension submodule, and a vibration and noise processing module; a Driver module for calculating a target acceleration based on a road spectrum target speed and a current speed of the vehicle; calculating a wheel end required torque based on the target acceleration; and converting the road spectrum target speed into a target speed; an Engine Map module for obtaining a next moment required throttle opening degree from a universal characteristic curve of the engine based on the wheel end required torque and the target speed, and obtaining a required cylinder pressure curve based on the throttle opening degree; a simulation module for using the required cylinder pressure curve as an excitation of the whole vehicle dynamics model to realize motion simulation of the whole vehicle dynamics model; in the simulation process, the dynamic total rigid body submodule calculates a dynamic total rigid body driving force based on a flywheel torque and an angular velocity of the engine as a suspension active side excitation force, the suspension submodule converts the suspension active side excitation force into suspension support reaction forces of suspension passive sides after wave attenuation of the suspension stiffness curve, and the vibration and noise processing module converts sound and vibration frequency domain transfer functions from the suspension passive sides to the vehicle interior into time domain transfer functions, and performs superposition and coupling calculation with the suspension support reaction forces to obtain vibration and noise of key points in the vehicle interior; a judgment module for judging isolation performance of the suspension stiffness curve based on the vibration and noise of the key points in the vehicle interior.

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

4. The system for evaluating the performance of a suspension stiffness curve according to claim 3, wherein The whole vehicle dynamics model further comprises: an engine submodule, which is a crankshaft connecting rod multi-body dynamics model comprising a piston, a connecting rod, a crankshaft, and a rigid body; a clutch submodule, which is a dynamics model comprising primary and secondary rotational inertia and torsional stiffness; a variable speed transmission submodule, which is a dynamics model comprising a speed ratio and an equivalent rotational inertia; A dynamic total rigid sub-module, which is a rigid model containing the inertia moment and inertia product of the dynamic total and accessory assembly; An upper car body sub-module, which is a rigid model containing the inertia moment, inertia product and mass; A lower car body sub-module, which is a rigid model containing the inertia moment, inertia product and bushing stiffness; A shock absorber sub-module, which is a one-way spring unit connecting the upper car body mounting point and the lower car body mounting point; A tire sub-module, which is a magic tire model containing the rotational inertia and stiffness.

5. A system for evaluating the performance of a suspension stiffness curve isolation according to claim 4, characterized in that, The crankshaft of the engine sub-module is connected to the clutch sub-module through a rotating friction pair; The secondary inertia of the clutch sub-module is connected to the speed ratio front equivalent inertia of the transmission sub-module through torsional stiffness; The transmission sub-module is connected to the tire sub-module through half shaft torsional stiffness and damping, to complete torque and rotational speed transmission, realize tire rotation and thus drive the vehicle motion; The dynamic total rigid sub-module is connected to the upper car body sub-module and the lower car body sub-module through the suspension sub-module; The upper car body sub-module and the lower car body sub-module are connected through the shock absorber sub-module, and the lower car body sub-module is connected to the tire sub-module.

6. A system for evaluating the performance of a suspension stiffness curve isolation according to claim 5, characterized in that, The use of demand cylinder pressure curve as the excitation of the vehicle dynamics model realizes the motion simulation of the vehicle dynamics model, including: dynamics simulation of vehicle road spectrum to power system rotation and road spectrum driving vehicle motion process simulation.

7. A system for evaluating the performance of a suspension stiffness curve isolation according to claim 6, characterized in that, The dynamics simulation of vehicle road spectrum to power system rotation includes: The Driver module outputs the wheel end demand torque based on the road spectrum target vehicle speed and the actual vehicle speed, and converts the road spectrum target vehicle speed into a target rotational speed; The Engine Map module obtains the next time demand throttle opening from the engine universal characteristic curve based on the wheel end demand torque and the target rotational speed, and obtains the demand cylinder pressure curve based on the throttle opening; The demand cylinder pressure curve is applied to the crankshaft and connecting rod multi-body dynamics model, and the crankshaft and connecting rod multi-body dynamics model outputs the flywheel torque and angular velocity; The flywheel torque and angular velocity are input into the transmission sub-module after completing fluctuation attenuation through the clutch sub-module, and are input into the tire sub-module after completing speed ratio conversion through the transmission sub-module, to realize the dynamics simulation of vehicle road spectrum to power system rotation.

8. The system for evaluating the performance of a suspension stiffness curve according to claim 7, wherein The road spectrum driving vehicle motion process simulation includes: The tire sub-module outputs the longitudinal driving force and speed to the lower car body sub-module, the lower car body sub-module outputs the longitudinal driving force and speed to the shock absorber sub-module, the shock absorber sub-module outputs the longitudinal driving force and speed to the upper car body sub-module, and the upper car body sub-module outputs the current vehicle speed to the Driver module, to realize the road spectrum driving vehicle motion process simulation.

9. An apparatus for evaluating isolation performance of a suspension rate curve, comprising: At least one processor; and a memory connected with the at least one processor in communication; wherein the memory stores instructions executable 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 perform the method of claim 1 for evaluating the isolation performance of the suspension stiffness curve.

10. A computer storage medium having stored executable instructions, which, when executed by a processor, enable the processor to implement the method of claim 1.

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