An analysis method and device for optimizing vehicle ride comfort

Abstract

The present application relates to a method and device for optimizing the ride comfort of an automobile, and relates to the technical field of vehicle structure design. The method includes the following steps: constructing a vehicle model and performing a driving simulation on a preset simulated road surface at a preset simulated vehicle speed; reading the vibration acceleration time-domain signals of a plurality of preset test points in three directions of a preset vehicle coordinate system, and obtaining the weighted root mean square values of acceleration in three directions of each preset test point and the total weighted root mean square value of each preset test point; calculating the root mean square of the total weighted root mean square value of each preset test point as the comprehensive total weighted root mean square value; performing a modal analysis on the vehicle model to analyze and obtain the parameter influencing factors of the comprehensive total weighted root mean square value. The present application establishes a vehicle multi-body dynamics simulation model, obtains analysis results based on simulation analysis, and then masters the influencing factors for optimizing the design of the rubber bushing structure and improving the ride comfort of the automobile.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle structure design, and in particular to a method and device for optimizing and analyzing the ride comfort of an automobile. Background Art

[0002] As the automotive market continues to increase its requirements for passenger car ride comfort, improving vehicle ride comfort has become a hot topic in automotive performance research. The ride comfort of a car during driving and braking is an important performance.

[0003] When a car is driving, the uneven road surface and the excitation of the engine and transmission shaft cause the car to vibrate, which puts the passengers in a vibrating environment, further affecting their comfort, work efficiency and health. Braking within a certain speed range causes the steering wheel, floor and pedals to vibrate violently, which is called brake judder. It affects driving comfort, increases the possibility of driver fatigue, and thus affects driving safety.

[0004] The reasons for brake jitter are: the thickness of the brake disc is different. When the brake pedal is pressed while the car is driving, the braking torque fluctuates, which generates excitation energy. When the excitation energy is transmitted to the steering wheel, floor, pedals and other parts, if the excitation frequency is consistent with the mode of the front suspension system, the excitation energy is amplified, resulting in severe jitter.

[0005] In order to achieve the best ride comfort of the car, many rubber elements of different shapes and functions are used in the connection between the car suspension system and the axle and frame. Because rubber materials have high elasticity, a relatively large deformation can occur when a small load is applied to the rubber element. When the load is removed, the rubber element returns to its original state; in addition, the friction damping generated by the internal structure of the rubber element when it is deformed can effectively attenuate the vibration transmitted to the rubber element by external excitation, thereby improving the ride comfort of the car. At the same time, the stiffness of the rubber bushing is closely related to the mode of the front suspension system. Adjusting the stiffness of the rubber bushing so that the mode of the front suspension system avoids the excitation frequency during braking can avoid resonance of the system and suppress the generation of brake tremor, thereby improving the ride comfort of the car during braking.

[0006] Therefore, how to understand the impact of vehicle design structure on vehicle ride comfort is an urgent problem that needs to be solved in order to improve vehicle ride comfort optimization analysis. Summary of the invention

[0007] The present application provides a method and device for optimizing and analyzing the ride comfort of an automobile, establishes a multi-body dynamics simulation model of the entire vehicle, obtains analysis results based on simulation analysis, and then grasps the influencing factors to optimize the design of the rubber bushing structure and improve the ride comfort of the automobile.

[0008] To achieve the above objectives, this application provides the following solutions.

[0009] In a first aspect, the present application provides a method for optimizing and analyzing the ride comfort of an automobile. The method includes the following steps:

[0010] Build a vehicle model and perform driving simulation on a preset simulated road surface at a preset simulated vehicle speed;

[0011] Read the vibration acceleration time-domain signals in three directions of a plurality of preset test points in a preset vehicle coordinate system, and obtain the root mean square values of the weighted acceleration in three directions of each preset test point and the total root mean square value of the weighted acceleration of each preset test point;

[0012] Calculate the root mean square of the total root mean square value of the weighted acceleration of each preset test point as the comprehensive total root mean square value of the weighted acceleration;

[0013] Perform modal analysis on the vehicle model to analyze the parameter influencing factors of the comprehensive total root mean square value of the weighted acceleration; wherein,

[0014] The smaller the comprehensive total root mean square value of the weighted acceleration, the better the ride comfort of the vehicle model.

[0015] Specifically, the method includes a formula for calculating the total root mean square value of the weighted acceleration. The formula for calculating the total root mean square value of the weighted acceleration is:

[0016] Wherein,

[0017] is the root mean square value of the weighted acceleration in the x-axis direction;

[0018] is the root mean square value of the weighted acceleration in the y-axis direction;

[0019] is the root mean square value of the weighted acceleration in the z-axis direction;

[0020] k x 、k y 、k z are the axis weighting coefficients corresponding to the x-axis, y-axis, and z-axis respectively;

[0021] j = 1, 2, 3 respectively correspond to the serial numbers of each preset test point;

[0022] is the total root mean square value of the weighted acceleration of a certain measurement point.

[0023] Specifically, the method includes a formula for calculating the comprehensive total root mean square value of the weighted acceleration. The formula for calculating the comprehensive total root mean square value of the weighted acceleration is:

[0024]

[0025] Specifically, the preset test points include above the seat cushion, the seat backrest, and above the foot floor.

[0026] Specifically, the parameter influencing factor is the Y-direction stiffness of the rubber bushing at the rear point of the triangular arm; among them,

[0027] The smaller the Y-direction stiffness of the rubber bushing at the rear point of the triangular arm, the smaller the root mean square value of the comprehensive total weighted acceleration, and the better the ride comfort of the vehicle model.

[0028] In a second aspect, the present application provides an apparatus for optimizing and analyzing vehicle ride comfort, the apparatus including:

[0029] A vehicle simulation module, which is used to construct a vehicle model and perform driving simulation on a preset simulation road surface at a preset simulation vehicle speed;

[0030] A root mean square value calculation module of the total weighted acceleration, which is used to read the vibration acceleration time domain signals in three directions of a plurality of preset test points in a preset vehicle coordinate system, and obtain the root mean square values of the weighted accelerations in three directions of each preset test point and the root mean square value of the total weighted acceleration of each preset test point;

[0031] A comprehensive root mean square value calculation module of the total weighted acceleration, which is used to calculate the root mean square of the root mean square values of the total weighted accelerations of each preset test point as the comprehensive root mean square value of the total weighted acceleration;

[0032] A parameter influencing factor analysis module, which is used to perform modal analysis on the vehicle model and analyze and obtain the parameter influencing factors of the comprehensive root mean square value of the total weighted acceleration; among them,

[0033] The smaller the comprehensive root mean square value of the total weighted acceleration, the better the ride comfort of the vehicle model.

[0034] Specifically, the apparatus includes a formula for calculating the root mean square value of the total weighted acceleration, and the formula for calculating the root mean square value of the total weighted acceleration is:

[0035] Among them,

[0036] is the root mean square value of the weighted acceleration in the x-axis direction;

[0037] is the root mean square value of the weighted acceleration in the y-axis direction;

[0038] is the root mean square value of the weighted acceleration in the z-axis direction;

[0039] k x 、k y 、k z are the axis weighting coefficients corresponding to the x-axis, y-axis, and z-axis respectively;

[0040] j = 1, 2, 3 respectively correspond to the serial numbers of each preset test point;

[0041] is the root mean square value of the total weighted acceleration of a certain measurement point.

[0042] Specifically, the device includes a comprehensive root mean square value calculation formula for the total weighted acceleration, and the comprehensive root mean square value calculation formula for the total weighted acceleration is:

[0043]

[0044] Specifically, the preset test points include above the seat cushion, the seat backrest, and above the foot floor.

[0045] Specifically, the parameter influencing factor is the Y-direction stiffness of the rubber bushing at the rear point of the triangular arm; among them,

[0046] The smaller the Y-direction stiffness of the rubber bushing at the rear point of the triangular arm, the smaller the comprehensive root mean square value of the total weighted acceleration, and the better the ride comfort of the vehicle model.

[0047] The beneficial effects brought by the technical solution provided in this application include:

[0048] This application establishes a vehicle multi-body dynamics simulation model. Based on the simulation analysis, it analyzes the influence of the Y-direction stiffness of the rubber bushing at the rear point of the triangular arm on the ride comfort and the front suspension system mode. According to the analysis results, it masters the influencing factors and optimizes the design of the rubber bushing structure to improve the ride comfort of the vehicle. Description of the Drawings

[0049] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0050] Figure 1 is the step flow chart of the vehicle driving control method provided in the embodiment of this application;

[0051] Figure 2 is the schematic diagram of the vehicle multi-body dynamics model of the vehicle driving control method provided in the embodiment of this application;

[0052] Figure 3 is the schematic diagram of the vehicle coordinate system of the vehicle driving control method provided in the embodiment of this application;

[0053] Figure 4 is the schematic diagram of the time domain signal of the vehicle driving control method provided in the embodiment of this application;

[0054] Figure 5 This is the weighted root mean square value curve graph of the vehicle driving control method provided in the embodiment of the present application;

[0055] Figure 6 This is the structural schematic diagram of the asymmetric structure rubber stiffness bushing of the vehicle driving control method provided in the embodiment of the present application;

[0056] Figure 7 This is the structural block diagram of the vehicle driving control device provided in the embodiment of the present application. Detailed implementation manners

[0057] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0058] The following further elaborates on the embodiments of the present application with reference to the accompanying drawings.

[0059] The embodiment of the present application provides a vehicle driving control method and device, which establish a vehicle multi-body dynamics simulation model. Based on simulation analysis, analyze the influence of the Y-direction stiffness of the rubber bushing at the rear point of the triangular arm on the ride comfort and the front suspension system mode. According to the analysis results, master the influencing factors, optimize the design of the rubber bushing structure, and improve the ride comfort of the vehicle.

[0060] To achieve the above technical effects, the general idea of the present application is as follows:

[0061] An analysis method for optimizing vehicle ride comfort, the method includes the following steps:

[0062] S1. Construct a vehicle model and perform driving simulation on a preset simulated road surface at a preset simulated vehicle speed;

[0063] S2. Read the vibration acceleration time domain signals in three directions of multiple preset test points in the preset vehicle coordinate system, and obtain the weighted acceleration root mean square values of each preset test point in the three directions and the total weighted acceleration root mean square value of each preset test point;

[0064] S3. Calculate the root mean square of the total weighted acceleration root mean square value of each preset test point as the comprehensive total weighted acceleration root mean square value;

[0065] S4. Perform modal analysis on the vehicle model to analyze and obtain the parameter influencing factors of the comprehensive total weighted acceleration root mean square value; wherein,

[0066] The smaller the comprehensive total weighted root mean square value of acceleration is, the better the ride comfort of the vehicle model is.

[0067] The following further elaborates on the embodiments of the present application in conjunction with the accompanying drawings.

[0068] In a first aspect, an embodiment of the present application provides a method for optimizing and analyzing the ride comfort of an automobile, the method comprising the following steps:

[0069] S1. Construct a vehicle model and perform a driving simulation on a preset simulated road surface at a preset simulated vehicle speed;

[0070] S2. Read the vibration acceleration time-domain signals in three directions of a plurality of preset test points in a preset vehicle coordinate system, and obtain the weighted root mean square values of acceleration in three directions of each preset test point and the total weighted root mean square value of each preset test point;

[0071] S3. Calculate the root mean square of the total weighted root mean square values of acceleration of each preset test point as the comprehensive total weighted root mean square value of acceleration;

[0072] S4. Perform a modal analysis on the vehicle model to analyze and obtain the parameter influencing factors of the comprehensive total weighted root mean square value of acceleration; wherein,

[0073] The smaller the comprehensive total weighted root mean square value of acceleration is, the better the ride comfort of the vehicle model is.

[0074] With the continuous improvement of the requirements for the ride comfort of passenger cars in the automotive market, improving the ride comfort of automobiles has become a hot issue in automotive performance research. The ride comfort during both driving and braking of an automobile is an important performance. When an automobile is driving, due to the uneven road surface and the exciting effects of the engine and the transmission shaft, etc., the automobile vibrates, placing the occupants in a vibrating environment, which further affects the comfort, work efficiency, and physical health of the occupants. When braking within a certain vehicle speed range, the severe shaking of the steering wheel, floor, and pedal caused is called the braking shake phenomenon, which affects the ride comfort, increases the possibility of driver fatigue, and further affects driving safety. The reasons for the occurrence of braking shake are as follows: there is a difference in the thickness of the brake disc. When the brake pedal is depressed during the driving of the automobile, it causes fluctuations in the braking torque, that is, excitation energy is generated; during the process of the excitation energy being transmitted to parts such as the steering wheel, floor, and pedal, if the excitation frequency is consistent with the modal of the front suspension system, the excitation energy is amplified, resulting in severe shaking.

[0075] To achieve the best ride comfort of the vehicle, many rubber components with different shapes and functions are used at the connections between the vehicle suspension system and the axle and the frame. Due to the high elastic properties of rubber materials, relatively large deformations can occur in the rubber components when a small load is applied. After the load is removed, the rubber components return to their original state. In addition, the frictional damping generated within the internal structure of the rubber components during deformation can effectively attenuate the vibrations transmitted from external excitations to the rubber components, thereby improving the ride comfort when the vehicle is driving. At the same time, the stiffness of the rubber bushing is closely related to the mode of the front suspension system. By adjusting the stiffness of the rubber bushing to avoid the excitation frequency during braking in the front suspension system mode, resonance of the system can be avoided, the generation of braking jitter can be suppressed, and thus the ride comfort during vehicle braking can be improved.

[0076] The rubber bushing at the rear point of the triangular arm is called the ride comfort bushing, and its Y-direction stiffness, that is, the stiffness in the Y-axis direction in the preset vehicle coordinate system, has a significant impact on the ride comfort of the vehicle. By means of simulation analysis, studying the influence of the Y-direction stiffness of the rubber bushing at the rear point of the triangular arm on the ride comfort of the whole vehicle and optimizing the structure of the rubber bushing can improve the ride comfort of the whole vehicle.

[0077] In the embodiments of the present application, a multi-body dynamics simulation model of the whole vehicle is established. Based on the simulation analysis, the influence of the Y-direction stiffness of the rubber bushing at the rear point of the triangular arm on the ride comfort and the mode of the front suspension system is analyzed. According to the analysis results, the influencing factors are grasped, and the structure of the rubber bushing is optimized to improve the ride comfort of the vehicle.

[0078] It should be noted that the multi-body dynamics model of the whole vehicle in the embodiments of the present application is as shown in the Figure 2 accompanying drawings of the specification. The front suspension system includes a front bracket, a triangular arm, a steering system, and front wheels, and the rear suspension system includes a rear bracket and rear wheels;

[0079] In the vehicle coordinate system of the embodiments of the present application, the X direction is the vehicle driving direction, the Y direction is the direction perpendicular to the driving direction, and the Z direction is the vertical direction;

[0080] The Y-direction stiffness of the rubber bushing at the rear point of the triangular arm is represented by KrY.

[0081] Specifically, the method includes the total weighted acceleration root mean square value calculation formula, and the total weighted acceleration root mean square value calculation formula is:

[0082] where,

[0083] is the root mean square value of the weighted acceleration in the x-axis direction;

[0084] is the root mean square value of the weighted acceleration in the y-axis direction;

[0085] is the root mean square value of the z - axis weighted acceleration;

[0086] k x and k y and k z are the axis - weighted coefficients corresponding to the x - axis, y - axis, and z - axis respectively;

[0087] j = 1, 2, 3 respectively correspond to the serial numbers of each preset test point;

[0088] is the root mean square value of the total weighted acceleration at a certain measurement point.

[0089] Specifically, the method includes a comprehensive formula for calculating the root mean square value of the total weighted acceleration, and the comprehensive formula for calculating the root mean square value of the total weighted acceleration is:

[0090]

[0091] Specifically, the preset test points include above the seat cushion, the seat backrest, and above the foot floor.

[0092] Specifically, the parameter influencing factor is the Y - direction stiffness of the rubber bushing at the rear point of the triangular arm; among which,

[0093] the smaller the Y - direction stiffness of the rubber bushing at the rear point of the triangular arm, the smaller the root mean square value of the comprehensive total weighted acceleration, and the better the ride comfort of the vehicle model.

[0094] Based on the above - mentioned technical solution of the embodiment of the present application, a specific implementation process is given as follows:

[0095] The first step is to use the vehicle model established in ADAMS / Car and pass through Class B and Class D roads at vehicle speeds of 40 km / h, 50 km / h, 60 km / h, and 70 km / h respectively.

[0096] The second step is that after the simulation is completed, read the vibration acceleration (m / s 2 ) time - domain signals in three directions at the measurement points above the seat cushion, the seat backrest, and the foot floor.

[0097] The third step is to calculate the root mean square value of the total weighted acceleration (m / s 2 ) at each point according to the root mean square value of the weighted acceleration (m / s 2 ) in three directions at each measurement point and the weighted coefficient;

[0098] Among which,

[0099] is the root mean square value of the weighted acceleration in the front - rear direction (i.e., the x - axis direction), with the unit of meters per second squared (m / s 2 );

[0100] is the root mean square value of the weighted acceleration in the left - right direction (i.e., the y - axis direction), with the unit of meters per second squared (m / s 2 );

[0101] is the root mean square value of the weighted acceleration in the vertical direction (i.e., the z - axis direction), with the unit of meters per second squared (m / s 2 );

[0102] k x 、k y 、k z are the axis - weighted coefficients corresponding to the x - axis, y - axis, and z - axis respectively;

[0103] j = 1, 2, 3 respectively correspond to the serial numbers of each preset test point. For example, they represent three positions: above the seat cushion, the seat backrest, and the foot floor respectively;

[0104] is the root mean square value of the total weighted acceleration at a certain measurement point, with the unit of meters per second squared (m / s 2 ).

[0105] In the fourth step, calculate the root mean square of the root mean square values of the total weighted accelerations at the three measurement points to obtain the comprehensive total weighted acceleration root mean square value (m / s 2 ). The lower the comprehensive total weighted acceleration root mean square value, the better the ride comfort;

[0106] Among them,

[0107] is the comprehensive total weighted acceleration root mean square value, with the unit of meters per second squared (m / s 2 ).

[0108] In the embodiments of the present application, modal analysis is performed: for the large system composed of the front suspension system, steering system, and front wheels, calculate its modal frequency;

[0109] The higher the system modal frequency, the more beneficial it is to avoid the excitation frequency during braking, can prevent the system from resonating, suppress the generation of braking jitter, and thus improve the ride comfort during vehicle braking.

[0110] Among them, specifically, ADAMS is used for modal analysis, and simulation is carried out based on the established multi - body model.

[0111] Specifically, it can be known from the results of multi - body dynamics simulation analysis that reducing KrY can improve the ride comfort;

[0112] while increasing KrY can improve the modal of the front suspension system, which is beneficial to improving the ride comfort during braking;

[0113] By calculating the ride comfort with different stiffnesses, as can be seen from the attached drawings of the specification Figure 5 the smaller the root mean square of the stiffness reduction, the better the ride comfort.

[0114] Taking the left triangular arm as the research object, when the vehicle is accelerating (pressing the accelerator pedal), the moving speed of the wheel is higher than that of the front bracket, so the rear pin of the triangular arm will move along the -Y direction, and the rear pin of the triangular arm acts on the -Y direction of the rear-point rubber bushing. When the vehicle is braking (pressing the brake pedal), the moving speed of the wheel is lower than that of the front bracket, so the rear point of the triangular arm will move along the Y direction, and the rear pin of the triangular arm acts on the Y direction of the rear-point rubber bushing. Considering the improvement of ride comfort and the improvement of the front suspension system mode, the rear-point rubber bushing of the triangular arm is designed as a left-right asymmetric structure, making the stiffness in the -Y direction as small as possible and the stiffness in the Y direction as large as possible, that is, Kr(-Y) << Kr(+Y).

[0115] When conducting the simulation, it can be known that the rear pin moves along the -Y direction during acceleration and along the +Y direction during braking;

[0116] Traditional rubber bushings are generally symmetric structures, with the same stiffness in the +Y and -Y directions. In the embodiments of the present application, based on the influence of the bushing stiffness on ride comfort, as shown in the attached drawings of the specification Figure 6 the inner and outer sides of the bushing in the Y direction are designed as an asymmetric structure, leaving a gap between the central rubber block and the outer rubber block, making the stiffness in the -Y direction as small as possible, and there is a metal block on the inner side of the central rubber block, making the stiffness in the +Y direction as large as possible.

[0117] It should be noted that the step numbers of each step in the embodiments of the present application do not limit the sequence of operations in the technical solution of the present application.

[0118] In a second aspect, based on the same inventive concept as the method embodiments, the embodiments of the present application provide an automobile ride comfort optimization analysis device, which includes:

[0119] A vehicle simulation module, which is used to build a vehicle model and perform driving simulation on a preset simulation road surface at a preset simulation vehicle speed;

[0120] A total weighted acceleration root mean square value calculation module, which is used to read the vibration acceleration time domain signals in three directions at multiple preset test points in a preset vehicle coordinate system, and obtain the weighted acceleration root mean square values of each preset test point in the three directions and the total weighted acceleration root mean square value of each preset test point;

[0121] A comprehensive total weighted acceleration root mean square value calculation module, which is used to calculate the root mean square of the total weighted acceleration root mean square values of each preset test point as the comprehensive total weighted acceleration root mean square value;

[0122] A parameter influence factor analysis module, which is used to perform modal analysis on the vehicle model and analyze the parameter influence factors for obtaining the comprehensive total weighted root mean square acceleration value; among them,

[0123] The smaller the comprehensive total weighted root mean square acceleration value is, the better the ride comfort of the vehicle model is.

[0124] With the continuous improvement of the requirements for the ride comfort of passenger cars in the automotive market, improving the ride comfort of vehicles has become a hot issue in automotive performance research. The ride comfort during vehicle driving and braking are both important performances. When the vehicle is driving, due to the uneven road surface and the excitation of the engine and drive shaft, etc., the vehicle vibrates, making the occupants in a vibrating environment, which further affects the comfort, work efficiency and physical health of the occupants. When braking within a certain vehicle speed range, the severe shaking of the steering wheel, floor and pedal caused is called the brake shaking phenomenon, which affects the ride comfort, increases the possibility of driver fatigue, and further affects the driving safety. The reasons for the generation of brake shaking are as follows: there is a thickness difference in the brake disc. When the brake pedal is depressed during vehicle driving, it causes fluctuations in the braking torque, that is, excitation energy is generated; during the process of the excitation energy being transmitted to parts such as the steering wheel, floor and pedal, if the excitation frequency is consistent with the front suspension system mode, the excitation energy is amplified, resulting in severe shaking.

[0125] In order to make the ride comfort of the vehicle reach the best state, many rubber components with different shapes and functions are used at the joints between the vehicle suspension system and the axle and the frame. Due to the high elastic performance of the rubber material, relatively large deformations can occur in the rubber components when applying a small load to the rubber components. After removing the load, the rubber components return to their original state; in addition, the frictional damping generated in the internal structure of the rubber components when they deform can effectively attenuate the vibration transmitted from the external excitation to the rubber components; thus improving the ride comfort during vehicle driving. At the same time, the rubber bushing stiffness is closely related to the front suspension system mode. By adjusting the rubber bushing stiffness to make the front suspension system mode avoid the excitation frequency during braking, resonance of the system can be avoided, and the generation of brake shaking can be suppressed, thereby improving the ride comfort during vehicle braking.

[0126] The rubber bushing at the rear point of the triangular arm is called the ride comfort bushing, and its Y-direction stiffness, that is, the stiffness in the Y-axis direction in the preset vehicle coordinate system, has a significant impact on the ride comfort of the vehicle. By means of simulation analysis, studying the influence of the Y-direction stiffness of the rubber bushing at the rear point of the triangular arm on the ride comfort of the whole vehicle and optimizing the structure of the rubber bushing can improve the ride comfort of the whole vehicle.

[0127] In the embodiments of the present application, a multi-body dynamics simulation model of the whole vehicle is established. Based on the simulation analysis, the influence of the Y-direction stiffness of the rubber bushing at the rear point of the triangular arm on the ride comfort and the front suspension system mode is analyzed. According to the analysis results, the influencing factors are grasped, and the structure of the rubber bushing is optimized to improve the ride comfort of the vehicle.

[0128] It should be noted that the multi-body dynamics model of the whole vehicle in the embodiments of the present application is as shown in the accompanying drawings of the specification. Figure 2 As shown, the front suspension system includes a front bracket, a triangular arm, a steering system, and front wheels, and the rear suspension system includes a rear bracket and rear wheels.

[0129] In the vehicle coordinate system of the embodiments of the present application, the X direction is the vehicle driving direction, the Y direction is the direction perpendicular to the driving direction, and the Z direction is the vertical direction.

[0130] The Y-direction stiffness of the rubber bushing at the rear point of the triangular arm is represented by KrY.

[0131] Specifically, the device includes a calculation formula for the root mean square value of the total weighted acceleration, and the calculation formula for the root mean square value of the total weighted acceleration is:

[0132] Among them,

[0133] is the root mean square value of the weighted acceleration in the x-axis direction;

[0134] is the root mean square value of the weighted acceleration in the y-axis direction;

[0135] is the root mean square value of the weighted acceleration in the z-axis direction;

[0136] k x 、k y 、k z are the axis weighting coefficients corresponding to the x-axis, y-axis, and z-axis respectively;

[0137] j = 1, 2, 3 respectively correspond to the serial numbers of each preset test point;

[0138] is the root mean square value of the total weighted acceleration at a certain measurement point.

[0139] Specifically, the device includes a calculation formula for the comprehensive root mean square value of the total weighted acceleration, and the calculation formula for the comprehensive root mean square value of the total weighted acceleration is:

[0140]

[0141] Specifically, the preset test points include above the seat cushion, the seat backrest, and above the foot floor.

[0142] Specifically, the parameter influencing factor is the Y-direction stiffness of the rubber bushing at the rear point of the triangular arm; among them,

[0143] the smaller the Y-direction stiffness of the rubber bushing at the rear point of the triangular arm, the smaller the comprehensive root mean square value of the total weighted acceleration, and the better the ride comfort of the vehicle model.

[0144] Based on the above technical solutions of the embodiments of the present application, a specific implementation process is given as follows:

[0145] First step, use the vehicle model established in ADAMS / Car and pass through Class B and Class D roads at vehicle speeds of 40 km / h, 50 km / h, 60 km / h, and 70 km / h respectively.

[0146] Second step, after the simulation is completed, read the vibration acceleration signals in three directions (m / s 2 ) in the time domain at the measuring points above the seat cushion, on the seat backrest, and on the foot floor.

[0147] Third step, calculate the overall weighted root mean square value of acceleration (m / s 2 ) at each point according to the weighted root mean square value of acceleration (m / s 2 ) in three directions at each measuring point and the weighting coefficients;

[0148] Among them,

[0149] is the weighted root mean square value of acceleration in the front-rear direction (i.e., the x-axis direction), with the unit of meters per second squared (m / s 2 );

[0150] is the weighted root mean square value of acceleration in the left-right direction (i.e., the y-axis direction), with the unit of meters per second squared (m / s 2 );

[0151] is the weighted root mean square value of acceleration in the vertical direction (i.e., the z-axis direction), with the unit of meters per second squared (m / s 2 );

[0152] k x 、k y 、k z are the axis weighting coefficients corresponding to the x-axis, y-axis, and z-axis respectively;

[0153] j = 1, 2, 3 respectively correspond to the serial numbers of each preset test point, for example, representing the three positions above the seat cushion, on the seat backrest, and on the foot floor respectively;

[0154] is the overall weighted root mean square value of acceleration at a certain measuring point, with the unit of meters per second squared (m / s 2 ).

[0155] Fourth step, calculate the root mean square of the overall weighted root mean square values of acceleration at the three measuring points to obtain the comprehensive overall weighted root mean square value of acceleration (m / s 2 ). The lower the comprehensive overall weighted root mean square value of acceleration, the better the ride comfort;

[0156] Among them,

[0157] is the comprehensive root mean square value of the total weighted acceleration, with the unit of meters per second squared (m / s 2 ).

[0158] In the embodiment of the present application, modal analysis is carried out: for the large system composed of the front suspension system, the steering system, and the front wheels, calculate its modal frequency;

[0159] The higher the system modal frequency, the more beneficial it is to avoid the excitation frequency during braking, which can prevent the system from resonating, suppress the generation of braking jitter, and thus improve the ride comfort during vehicle braking.

[0160] Among them, specifically, ADAMS is used for modal analysis, and simulation is carried out based on the established multi-body model.

[0161] Specifically, it can be seen from the results of multi-body dynamics simulation analysis that reducing KrY can improve the ride comfort;

[0162] while increasing KrY can improve the modal of the front suspension system, which is beneficial to improving the ride comfort during braking;

[0163] By calculating the ride comfort of different stiffnesses, as can be seen from the Figure 5 of the accompanying drawings of the specification, the smaller the root mean square of the reduced stiffness, the better the ride comfort.

[0164] Taking the left triangular arm as the research object, when the vehicle is accelerating (pressing the accelerator pedal), the wheel moving speed is higher than the speed of the front bracket, so the rear pin of the triangular arm will move along the -Y direction, and the rear pin of the triangular arm acts on the -Y direction of the rear point rubber bushing. When the vehicle is braking (pressing the brake pedal), the wheel moving speed is lower than the speed of the front bracket, so the rear point of the triangular arm will move along the Y direction, and the rear pin of the triangular arm acts on the Y direction of the rear point rubber bushing. Considering improving the ride comfort and the modal of the front suspension system, the rubber bushing at the rear point of the triangular arm is designed as an asymmetrical structure on the left and right, making the -Y direction stiffness as small as possible and the Y direction stiffness as large as possible, that is, Kr(-Y) << Kr(+Y).

[0165] During simulation, it can be known that when accelerating, the rear pin moves along the -Y direction, and when braking, the rear pin moves along the +Y direction;

[0166] Traditional rubber bushings are generally symmetrical structures, with the same stiffness in the +Y and -Y directions. In the embodiment of the present application, based on the influence of bushing stiffness on ride comfort, as shown in the Figure 6 of the accompanying drawings of the specification, the inner and outer sides of the bushing in the Y direction are designed as asymmetrical structures, with a gap reserved between the central rubber block and the outer rubber block, making the -Y direction stiffness as small as possible, and there is a metal block on the inner side of the central rubber block to make the +Y direction stiffness as large as possible.

[0167] It should be noted that for the vehicle ride comfort optimization analysis device provided in the embodiments of the present application, the corresponding technical problems, technical means, and technical effects are similar in principle to those of the vehicle ride comfort optimization analysis method.

[0168] It should be noted that in the present application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0169] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. An automotive ride comfort optimization analysis method, characterized in that, The method includes the following steps: Construct a vehicle model and perform a driving simulation on a preset simulated road surface at a preset simulated vehicle speed; Read the vibration acceleration time domain signals of multiple preset test points in three directions of a preset vehicle coordinate system, and obtain the weighted root mean square values of acceleration in three directions for each preset test point and the total weighted root mean square value of acceleration for each preset test point; Calculate the root mean square of the total weighted root mean square values of acceleration for each preset test point to obtain the comprehensive total weighted root mean square value of acceleration and the influence relationship between the comprehensive total weighted root mean square value of acceleration and the ride comfort during vehicle acceleration; Perform a front suspension system modal analysis on the vehicle model to analyze and obtain the influence parameters and influence relationships of ride comfort during vehicle braking; Based on the influence relationship between the comprehensive total weighted root mean square value of acceleration and the ride comfort during vehicle acceleration and the influence parameters and influence relationships of ride comfort during vehicle braking, obtain the parameter influence factors and parameter influence relationships of vehicle comprehensive ride comfort; Based on the parameter influence factors and the parameter influence relationships, obtain the optimized bushing structure; where The influence parameter of ride comfort during vehicle braking is the front suspension system modal frequency; The influence relationship of ride comfort during vehicle braking is that the higher the front suspension system modal frequency, the better the ride comfort during vehicle braking; The parameter influence factors of vehicle comprehensive ride comfort are the negative Y-direction stiffness and the positive Y-direction stiffness of the rear-point rubber bushing of the triangular arm; The parameter influence relationship of vehicle comprehensive ride comfort is that the smaller the negative Y-direction stiffness of the rear-point rubber bushing of the triangular arm on the left side of the vehicle and the larger the positive Y-direction stiffness of the rear-point rubber bushing of the triangular arm on the left side of the vehicle, the better the ride comfort of the vehicle model; In the optimized bushing structure, a gap is reserved between the central rubber block and the outer rubber block to make the -Y-direction stiffness as small as possible, and a metal block is provided inside the central rubber block to make the +Y-direction stiffness as large as possible.

2. The automotive ride comfort optimization analysis method according to claim 1, characterized in that, The method includes a formula for calculating the total weighted root mean square value of acceleration, and the formula for calculating the total weighted root mean square value of acceleration is: ; wherein, is the root mean square value of the x-axis weighted acceleration; is the root mean square value of the y-axis weighted acceleration; is the root mean square value of the z-axis weighted acceleration; , , are the axis weighting coefficients corresponding to the x-axis, y-axis, and z-axis, respectively; j = 1, 2, 3 respectively correspond to the serial numbers of each preset test point; is the root mean square value of the total weighted acceleration at a certain measuring point.

3. The automotive ride comfort optimization analysis method according to claim 2, characterized in that, The method includes a formula for calculating the comprehensive total weighted root mean square value of acceleration, and the formula for calculating the comprehensive total weighted root mean square value of acceleration is: 。 4. The automotive ride comfort optimization analysis method according to claim 1, characterized in that: The preset test points include above the seat cushion, the seat backrest, and above the foot floor.

5. An automotive ride comfort optimization analysis device, characterized in that, The device includes: A vehicle simulation module, which is used to construct a vehicle model and perform a driving simulation on a preset simulated road surface at a preset simulated vehicle speed; A total weighted root mean square value calculation module, which is used to read the vibration acceleration time domain signals of multiple preset test points in three directions of a preset vehicle coordinate system, and obtain the weighted root mean square values of acceleration in three directions for each preset test point and the total weighted root mean square value of acceleration for each preset test point; A comprehensive total weighted root mean square value calculation module, which is used to calculate the root mean square of the total weighted root mean square values of acceleration for each preset test point to obtain the comprehensive total weighted root mean square value of acceleration and the influence relationship between the comprehensive total weighted root mean square value of acceleration and the ride comfort during vehicle acceleration; A parameter influencing factor analysis module, which is used to perform a front suspension system modal analysis on the vehicle model, and analyze and obtain the influencing parameters and influencing relationships of the ride comfort during vehicle braking; The parameter influencing factor analysis module is also used to obtain the parameter influencing factors and parameter influencing relationships of the vehicle's comprehensive ride comfort based on the influencing relationship between the comprehensive total weighted root mean square acceleration value and the ride comfort during vehicle acceleration, as well as the influencing parameters and influencing relationships of the ride comfort during vehicle braking; The parameter influencing factor analysis module is also used to obtain the optimized bushing structure based on the parameter influencing factors and the parameter influencing relationships; wherein, The influencing parameter of the ride comfort during vehicle braking is the front suspension system modal frequency; The influencing relationship of the ride comfort during vehicle braking is that the higher the front suspension system modal frequency, the better the ride comfort during vehicle braking; The parameter influencing factors of the vehicle's comprehensive ride comfort are the negative Y-direction stiffness and the positive Y-direction stiffness of the rear point rubber bushing of the triangular arm; The parameter influencing relationship of the vehicle's comprehensive ride comfort is: the smaller the negative Y-direction stiffness of the rear point rubber bushing of the triangular arm on the left side of the vehicle, and the larger the positive Y-direction stiffness of the rear point rubber bushing of the triangular arm on the left side of the vehicle, the better the ride comfort of the vehicle model; In the optimized bushing structure, a gap is reserved between the central rubber block and the outer rubber block to make the -Y-direction stiffness as small as possible, and a metal block is arranged inside the central rubber block to make the +Y-direction stiffness as large as possible.

6. The vehicle ride comfort optimization analysis device according to claim 5, wherein, The device includes a formula for calculating the total weighted root mean square acceleration value, and the formula for calculating the total weighted root mean square acceleration value is: ; wherein, is the root mean square value of the x-axis weighted acceleration; is the root mean square value of the y-axis weighted acceleration; is the root mean square value of the z-axis weighted acceleration; , , are the axis weighting coefficients corresponding to the x-axis, y-axis, and z-axis, respectively; j = 1, 2, 3 respectively correspond to the serial numbers of each preset test point; is the root mean square value of the total weighted acceleration at a certain measuring point.

7. The vehicle ride comfort optimization analysis device according to claim 6, wherein, The device includes a formula for calculating the comprehensive total weighted root mean square acceleration value, and the formula for calculating the comprehensive total weighted root mean square acceleration value is: 。 8. The vehicle ride comfort optimization analysis device according to claim 5, wherein: The preset test points include above the seat cushion, the seat backrest, and above the foot floor.

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