Damping identification method and system for shear type suspension seat

Abstract

The invention relates to the technical field of seat dynamic characteristic research, and provides a damping identification method and system for a shear type suspension seat, and the method comprises the steps: obtaining a shear type suspension structure simplification model; carrying out stress analysis on the simplified model of the shear type suspension structure to obtain an equivalent damping calculation expression of a shear type suspension seat vibration system; obtaining an equivalent damping calculation expression of a general vibration system; according to the equivalent damping calculation expression of the shear type suspension seat vibration system and the equivalent damping calculation expression of the common vibration system, the equivalent damping calculation expression of the shear type suspension seat is obtained. According to the method, model simplification is carried out on the shear type suspension seat, stress analysis is carried out on the simplified model of the shear type suspension structure, the damping calculation expression of the shear type suspension seat structure is completely deduced, the precision of the seat simulation model can be improved, and the result error of dynamic simulation calculation is reduced; a guidance scheme can be provided for the suspension design of the air suspension type seat, and the dynamic performance of a seat product is improved.

Description

Technical Field

[0001] The present application relates to the technical field of dynamic characteristic research of a scissor-type suspension seat vibration system, and in particular to a damping identification method and system for a scissor-type suspension seat. Background Art

[0002] Studies have shown that professional drivers are continuously exposed to whole-body vibration caused by road excitation during their daily work. This not only reduces work efficiency, but also harms physical health, leading to many occupational diseases, such as lumbar pain and other physical diseases. Scissor suspension seats are widely used in commercial vehicles and other vehicles. Their vibration isolation effect helps to reduce the vibration of drivers, improve the working environment of drivers, and improve the ride comfort of vehicles.

[0003] Most modern seat suspensions are scissor-type suspension seats. The vibration system of scissor-type suspension seats is generally composed of guide support mechanism, air spring, damper, slider and seat cushion. However, due to the complex dynamic characteristics of the scissor-type guide support mechanism, most seat optimization designs do not consider the specific seat scissor-type suspension structure, but directly use the parameters of springs and damping or the equivalent stiffness obtained by testing to establish dynamic or mathematical models. The stiffness and damping calculation expressions of the scissor-type suspension seat structure are not fully derived theoretically, resulting in a large error between the theoretical model and the actual model, which leads to great difficulties in the optimization design of the seat. Summary of the invention

[0004] The present application provides a damping identification method and system for a scissor-type suspension seat, which can solve the complex dynamic characteristics of the scissor-type guide support mechanism in the prior art. Most seat optimization designs do not take into account the specific seat scissor-type suspension structure, and do not fully derive the damping calculation expression of the scissor-type suspension seat structure from a theoretical perspective, resulting in a large error between the theoretical model and the actual model, leading to technical problems that are quite difficult for the optimization design of the seat.

[0005] In a first aspect, the present application provides a damping identification method for a scissor suspension seat, comprising the following steps:

[0006] Simplify the scissor suspension structure of the seat to obtain a simplified model of the scissor suspension structure;

[0007] Perform stress analysis on the simplified model of the scissor suspension structure and obtain the equivalent damping calculation expression of the scissor suspension seat vibration system;

[0008] Obtain the equivalent damping calculation expression for general vibration systems;

[0009] According to the equivalent damping calculation expression of the scissor-type suspension seat vibration system and the equivalent damping calculation expression of the general vibration system, the equivalent damping calculation expression of the scissor-type suspension seat is obtained.

[0010] In combination with the second aspect, in one implementation, the force analysis of the simplified model of the scissor suspension structure to obtain an equivalent damping calculation expression for the scissor suspension seat vibration system specifically includes the following steps:

[0011] Establish the overall force balance equation of the seat;

[0012] Obtain calculation expressions for air spring force, damper damping force, and friction force;

[0013] Obtain the force equilibrium equations of the two shear rods of the seat scissor suspension;

[0014] The overall force balance equation of the seat and the calculation expressions of the air spring force, damping force of the damper and friction force as well as the force balance equation of the two shear rods of the scissor suspension of the seat are combined to obtain the general form of the vibration differential equation of the scissor suspension seat vibration system under the simple harmonic excitation.

[0015] Compare the coefficients of the obtained general form of vibration differential equation and obtain the damping ratio calculation expression;

[0016] The calculation expression of damping ratio and damping coefficient is combined to obtain the equivalent damping calculation expression of scissor suspension seat vibration system.

[0017] In conjunction with the second aspect, in one implementation, the overall force balance equation of the seat is as shown below:

[0018] ΣX=0,F cx +F bx -F d cosθ=0

[0019]

[0020] In the formula, ΣX is the force balance equation of the vibration system in the x direction; ΣY is the force balance equation of the vibration system in the y direction; ΣM c The overall moment balance equation of the simplified model of the scissor suspension structure; F cx is the X-direction force at point C; F bx is the X-direction force acting on point B; F d is the damping force of the damper; F cy is the Y-direction force at point C; F by is the Y-direction force at point B; m is the overall mass of the suspension.

[0021] In combination with the second aspect, in one implementation, obtaining the force balance equation of the two shear rods of the seat scissor suspension specifically includes:

[0022] The force analysis of the first shear bar is performed, and the force balance equation of the first shear bar is obtained as shown below:

[0023] ΣX=0,F ox -F' ax +F bx =0

[0024] ΣY=0,F by +F' oy -F ay =0

[0025] ∑M O =0,F ax l1sinα+F ay l1cosα+F by l2cosα+F by l2sinα=0

[0026] In the formula, ∑X is the force balance equation in the x direction; ∑Y is the force balance equation in the y direction; ∑M o The force balance equation of the center point of AB rod of the simplified scissor suspension structure model; F ox is the force in the X direction at point O; F ax is the force in the X direction at point A; F bx is the force in the X direction at point B; F by is the force in the Y direction at point B; F oy is the force in the X direction at point O; F ay is the force in the Y direction at point A; l1 is the first length variable of the vibration system; l2 is the second length variable of the vibration system;

[0027] The force analysis of the second shear rod is carried out, and the force equilibrium equation of the second shear rod is obtained as follows:

[0028] ∑X=0,F cx -F ox +F dx =0

[0029] ∑Y=0,F cy -F dy -F oy -F k =0

[0030] ∑M O =0,F cx l2sinα-F cy l2cosα-F dx l1sinα-F dy l1cosα=0

[0031] In the formula, ∑X is the force balance equation in the x direction; ∑Y is the force balance equation in the y direction; ∑Mo The force balance equation of the center point of CD rod of the simplified scissor suspension structure is: cx is the force in the X direction at point C, F ox is the force in the X direction at point O, F dx is the force in the X direction at point D, F cy is the force in the Y direction at point C, F dy is the force in the Y direction at point D, F oy is the force in the Y direction at point O, F k is the air spring force.

[0032] In conjunction with the second aspect, in one implementation, the damping ratio calculation expression is as shown below:

[0033]

[0034] Where ξ is the damping ratio; ω0 is the initial angular velocity, m is the overall mass of the suspension; α is the angle between the first shear rod and the seat bottom plate; θ is the angle between the second shear rod and the seat bottom plate; l1 is the first length variable of the vibration system; l2 is the second length variable of the vibration system; and c is the equivalent damping of the general vibration system.

[0035] In combination with the second aspect, in one implementation, the damping ratio calculation expression and the damping coefficient calculation expression are combined to obtain an equivalent damping calculation expression for the scissor suspension seat vibration system, as shown in the following formula:

[0036]

[0037] In the formula, C S is the equivalent damping of the scissor suspension seat vibration system; c is the equivalent damping of the general vibration system; α is the angle between the first shear rod and the seat bottom plate; θ is the angle between the second shear rod and the seat bottom plate; l1 is the first length variable of the vibration system; l2 is the second length variable of the vibration system.

[0038] In conjunction with the second aspect, in one implementation, obtaining an equivalent damping calculation expression for a general vibration system specifically includes the following steps:

[0039] Obtain the differential equation of motion for a mass-spring system with dry friction damping in a single degree of freedom;

[0040] The initial displacement excitation and steady-state displacement response of the mass-spring system are given;

[0041] Derive the calculation expressions for the negative work done by the damping force and the work done by the friction force in one cycle of the scissor suspension seat when dry friction damping force exists in the scissor suspension seat;

[0042] The negative work done by the damping force and the work done by the friction force are calculated together, and the calculation expression of the equivalent damping of the general vibration system is obtained according to the equivalent viscous damping law.

[0043] In conjunction with the second aspect, in one implementation, the equivalent damping calculation expression is as shown below:

[0044]

[0045] Where c is the equivalent damping of the general vibration system; F f is the friction force; A is the current amplitude of the vibration system, w is the angular velocity, and A is the current amplitude.

[0046] In a second aspect, the present application provides a system for identifying friction damping of a scissor suspension seat, comprising:

[0047] A simplified model acquisition module is used to simplify the scissor-type suspension structure of the seat and obtain a simplified model of the scissor-type suspension structure;

[0048] The scissor suspension system equivalent damping calculation module is connected to the simplified model acquisition module for performing force analysis on the simplified model of the scissor suspension structure to obtain an equivalent damping calculation expression for the scissor suspension seat vibration system;

[0049] General vibration system equivalent damping calculation module, used to obtain the equivalent damping calculation expression of the general vibration system;

[0050] The scissor-type suspension seat equivalent damping calculation module is communicatively connected with the scissor-type suspension system equivalent damping calculation module and the general vibration system equivalent damping calculation module, and is used for obtaining the equivalent damping calculation expression of the scissor-type suspension seat according to the equivalent damping calculation expression of the scissor-type suspension seat vibration system and the equivalent damping calculation expression of the general vibration system.

[0051] In conjunction with the second aspect, in one implementation, the scissor suspension system equivalent damping calculation module includes:

[0052] Overall force analysis unit, used to establish the overall force balance equation of the seat;

[0053] A vibration-related force acquisition unit, used to obtain calculation expressions of air spring force, damper damping force and friction force;

[0054] Local force analysis unit, used to obtain the force balance equation of the two shear rods of the seat scissor suspension;

[0055] A suspension system vibration differential equation acquisition unit is connected to the overall force analysis unit, the vibration-related force acquisition unit and the local force analysis unit, and is used to combine the overall force balance equation of the seat with the calculation expressions of the air spring force, the damping force of the damper and the friction force, and the force balance equation of the two shear rods of the scissor suspension of the seat, so as to obtain a general form of vibration differential equation of the scissor suspension seat vibration system under the simple harmonic excitation;

[0056] A coefficient comparison unit is connected to the suspension system vibration differential equation acquisition unit for performing coefficient comparison on the obtained general form of the vibration differential equation to obtain a damping ratio calculation expression;

[0057] The suspension system equivalent damping calculation unit is connected to the coefficient comparison unit for simultaneously calculating the damping ratio and the damping coefficient to obtain the equivalent damping calculation expression of the scissor suspension seat vibration system.

[0058] The beneficial effects brought by the technical solution provided by the embodiment of the present application include at least:

[0059] By simplifying the model of the scissor-type suspension seat, performing force analysis on the simplified model of the scissor-type suspension structure, and completely deriving the damping calculation expression of the scissor-type suspension seat structure, the accuracy of the seat simulation model can be improved, making the error of the results of the dynamic simulation calculation smaller; it can provide guidance for the suspension design of air-suspended seats, improve the dynamic performance of seat products, and help improve passenger riding comfort and the competitiveness of seat products. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 A schematic flow chart of a damping identification method for a scissor-type suspension seat of the present application;

[0061] Figure 2 A simplified model diagram of the scissor-type suspension structure provided in an embodiment of the present application;

[0062] Figure 3 The overall force analysis diagram of the suspension provided in the embodiment of the present application;

[0063] Figure 4 Force analysis diagram of the first shear rod according to the embodiment of the present invention;

[0064] Figure 5 Force analysis diagram of the second shear rod according to the embodiment of the present invention;

[0065] Figure 6 A seat dynamics model provided in an embodiment of the present application;

[0066] Figure 7 A comparison chart of the change of the seat resonance frequency with different damping levels after using equivalent damping and the experimental results provided in the embodiment of the present application;

[0067] Figure 8 A comparison chart of the seat transmission rate after using equivalent damping with different damping gears and experimental results provided in the embodiment of the present application;

[0068] Fig. 9 A comparison chart of the seat resonance frequency without equivalent damping provided in the embodiment of the present application with the experimental results and the changing rules of the seat resonance frequency with different damping levels;

[0069] Fig.10 This is a comparison chart of the seat transfer rate without using equivalent damping with different damping levels and the experimental results provided in the embodiment of the present application. DETAILED DESCRIPTION

[0070] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0071] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit "first", "second" and "third" to different types.

[0072] In the description of the embodiments of the present application, "exemplary", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a specific way.

[0073] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; the “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0074] In some processes described in the embodiments of the present application, multiple operations or steps that appear in a specific order are included, but it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or in parallel, and the sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0075] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0076] This application is based on a certain type of commercial vehicle scissor suspension seat and involves a simplified model of the scissor suspension structure, force analysis and friction damping calculation.

[0077] Please refer to Figure 1 The present application provides a damping identification method for a scissor suspension seat, comprising the following steps:

[0078] Step S1: simplifying the scissor-type suspension structure of the seat to obtain a simplified model of the scissor-type suspension structure;

[0079] Step S2: performing a force analysis on the simplified model of the scissor suspension structure to obtain an equivalent damping calculation expression for the scissor suspension seat vibration system;

[0080] Step S3: Obtaining an equivalent damping calculation expression for a general vibration system;

[0081] Step S4: Obtain an equivalent damping calculation expression for the scissor-type suspension seat according to an equivalent damping calculation expression for the scissor-type suspension seat vibration system and an equivalent damping calculation expression for a general vibration system.

[0082] The damping identification method for the scissor-type suspension seat provided in this application can improve the accuracy of the seat simulation model, making the error of the results of the dynamic simulation calculation smaller; it can provide guidance for the suspension design of the air suspension seat, improve the dynamic performance of the seat product, and help improve the passenger riding comfort and the competitiveness of the seat product.

[0083] In one embodiment, if Figure 2 As shown, the step S1: simplifying the scissor-type suspension structure of the seat to obtain the following simplified scissor-type suspension structure model:

[0084] The seat upper plate 1 is connected to the seat bottom plate 4 by two shear rods hinged at point O;

[0085] The first shear rod 3 intersects with the seat upper plate 1 at A, and the lower end point B of the first shear rod 3 can slide along the track in the linear slide groove on the right side of the seat bottom plate 1;

[0086] The second shear bar 2 intersects with the seat upper plate 1 at D, and the second shear bar 2 intersects with the seat bottom plate 4 at C;

[0087] The air spring 5 has a stiffness of K and is arranged between the two shear rods and the seat bottom plate 4. The vibration damper 6 is arranged on the crossbar between the seat bottom plate 4 and the shear frame. The air spring force and the damping force of the vibration damper 6 act on the seat upper plate 1 through the shear rods.

[0088] The included angle between the first shear bar 3 and the seat bottom plate 4 is α, and the included angle between the second shear bar 2 and the seat bottom plate 4 is θ.

[0089] In one embodiment, the step S2: performing a force analysis on the simplified model of the scissor-type suspension structure to obtain an equivalent damping calculation expression for the scissor-type suspension seat vibration system specifically includes the following steps:

[0090] Step S21: Establishing the overall force balance equation of the seat;

[0091] Step S22: obtaining calculation expressions of air spring force, damper damping force and friction force;

[0092] Step S23: Obtaining the force balance equation of the two shear rods of the seat scissor suspension;

[0093] Step S24: combining the overall force balance equation of the seat, the calculation expressions of the air spring force, the damping force of the damper and the friction force, and the force balance equation of the two shear rods of the scissor suspension of the seat, to obtain a general form of vibration differential equation of the scissor suspension seat vibration system under simple harmonic excitation;

[0094] Step S25: performing coefficient comparison on the obtained general form of vibration differential equation to obtain a damping ratio calculation expression;

[0095] Step S26: The damping ratio calculation expression and the damping coefficient calculation expression are combined to obtain an equivalent damping calculation expression for the scissor suspension seat vibration system.

[0096] In one embodiment, if Figure 3 As shown, the step S21: establish the overall force balance equation of the seat, as shown in the following formula:

[0097]

[0098] In the formula, ∑X is the force balance equation of the vibration system in the x direction; ∑Y is the force balance equation of the vibration system in the y direction; ∑M c The overall moment balance equation of the simplified model of the scissor suspension structure; F cx is the X-direction force at point C; F bx is the X-direction force acting on point B; F d is the damping force of the damper; F cy is the Y-direction force at point C; F by is the Y-direction force at point B; m is the overall mass of the suspension.

[0099] In one embodiment, in step S22:

[0100] The calculation expression for obtaining the air spring force is as follows:

[0101]

[0102] In the formula, F k is the air spring force; k is the stiffness coefficient of the air spring, usually in N / m; y0 is the initial length of the air spring; y is the length of the air spring after deformation; l1 is the first length variable of the air spring; l2 is the second length variable of the air spring;

[0103] The calculation expression for obtaining the damping force of the damper is as follows:

[0104]

[0105] In the formula, F d is the damping force of the damper; c is the damping coefficient, the unit is usually N·s / m; is the current speed of the damper; is the initial velocity of the damper;

[0106] The calculation expression for obtaining friction force is as follows:

[0107] F fb =μF by Formula (4)

[0108] In the formula, F fb is the friction force at point B; μ is the friction coefficient; F by is the y-direction pressure at point B.

[0109] In one embodiment, the step S23: obtaining the force balance equation of the two shear rods of the seat scissor suspension specifically includes the following steps:

[0110] Step S231: Figure 4As shown, the force analysis of the AB rod is carried out, and the force balance equation of the first shear rod is obtained as shown in the following formula:

[0111]

[0112] In the formula, ∑X is the force balance equation in the x direction; ∑Y is the force balance equation in the y direction; ∑M o The force balance equation of the center point of AB rod of the simplified scissor suspension structure is: ox is the force in the X direction at point O, F ax is the force in the X direction at point A, F bx is the force in the X direction at point B, F by is the force in the Y direction at point B, F oy is the force in the Y direction at point O, F ay is the force in the Y direction at point A, l1 is the first length variable of the vibration system; l2 is the second length variable of the vibration system.

[0113] Step S232: Figure 5 As shown in the figure, the force analysis of the CD rod is carried out, and the force equilibrium equation of the second shear rod is obtained as follows:

[0114]

[0115] In the formula, ∑X is the force balance equation in the x direction; ∑Y is the force balance equation in the y direction; ∑M o The force balance equation of the center point of CD rod of the simplified scissor suspension structure is: cx is the force in the X direction at point C, F ox is the force in the X direction at point O, F dx is the force in the X direction at point D, F cy is the force in the Y direction at point C, F dy is the force in the Y direction at point D, F oy is the force in the Y direction at point O, F k is the air spring force.

[0116] In one embodiment, the step S24: combining the overall force balance equation of the seat and the calculation expressions of the air spring force, the damping force of the damper and the friction force, and the force balance equation of the two shear rods of the scissor suspension of the seat, to obtain the general form of the vibration differential equation of the scissor suspension seat vibration system under the simple harmonic excitation, is specifically implemented as follows:

[0117] By transforming equations (1), (2), (3) and (4), we can obtain the force calculation expression in the Y direction at point B:

[0118]

[0119] In the formula, F by is the force in the Y direction at point B; k is the stiffness coefficient of the air spring; m is the overall mass of the suspension; is the acceleration of the vibration system; l1 is the first length variable of the vibration system; l2 is the second length variable of the vibration system;

[0120] By combining equations (2), (3), (4), (5), (6) and (7), we can obtain the general form of the vibration differential equation of the vibration system under simple harmonic excitation.

[0121] In one embodiment, step S25: performing coefficient comparison on the obtained general form of the vibration differential equation to obtain a damping ratio calculation expression is specifically implemented as follows:

[0122] The general form of the vibration differential equation of the vibration system under simple harmonic excitation is combined with the second-order linear ordinary differential equation of the damped single-degree-of-freedom vibration system conduct By comparing the coefficients of the term, the calculation expression of the damping ratio ξ is as follows:

[0123]

[0124] Where ξ is the damping ratio; ω0 is the initial angular velocity; m is the overall mass of the suspension; α is the angle between the first shear rod and the seat bottom; θ is the angle between the second shear rod and the seat bottom; l1 is the first length variable of the vibration system; l2 is the second length variable of the vibration system; and c is the equivalent damping of the general vibration system.

[0125] In one embodiment, step S26: the damping ratio calculation expression and the damping coefficient calculation expression are combined to obtain the equivalent damping calculation expression of the scissor suspension seat vibration system, which is specifically implemented as follows:

[0126] Combined damping ratio calculation expression and damping coefficient calculation expression C S =2mξω0, and the equivalent damping C of the scissor suspension seat vibration system is obtained S The calculation expression is as follows:

[0127]

[0128] In the formula, C S is the equivalent damping of the scissor suspension seat vibration system; c is the equivalent damping of the general vibration system; α is the angle between the first shear rod and the seat bottom plate; θ is the angle between the second shear rod and the seat bottom plate; l1 is the first length variable of the vibration system; l2 is the second length variable of the vibration system.

[0129] In one embodiment, the step S3: obtaining an equivalent damping calculation expression for a general vibration system specifically includes the following steps:

[0130] Step S31: obtaining a motion differential equation of a mass-spring system with dry friction damping under a single degree of freedom;

[0131] Step S32: providing an initial displacement excitation and a steady-state displacement response of the mass-spring system;

[0132] Step S33: deriving a calculation expression for the negative work done by the damping force and the work done by the friction force in one cycle of the scissor-type suspension seat when dry friction damping force exists in the scissor-type suspension seat;

[0133] Step S34: The negative work done by the damping force and the work done by the friction force are calculated together, and the calculation expression of the equivalent damping of the general vibration system is obtained according to the equivalent viscous damping law.

[0134] In one embodiment, the step S31: obtaining the motion differential equation of the mass-spring system with dry friction damping under single degree of freedom, as shown in the following equation:

[0135]

[0136] Where m is the overall mass of the suspension; is the acceleration of the vibration system at time t; x(t) is the steady-state response of the vibration system; k is the stiffness of the vibration system; F f is the friction force; F(t) is the exciting force; μ is the friction coefficient; F N is the normal pressure on the friction surface.

[0137] In one embodiment, the step S32: giving the initial displacement excitation of the vibration system and the steady-state displacement response displacement of the vibration system is as shown in the following formula:

[0138] The initial displacement excitation calculation expression of the vibration system is:

[0139] x0=A0sin(wt) Formula (12)

[0140] Where x0 is the initial displacement of the vibration system; A0 is the initial amplitude of the vibration system; w is the angular frequency; and t is the time.

[0141] The steady-state displacement response of the vibration system is calculated by:

[0142]

[0143] Where x(t) is the displacement of the vibration system at time t; A is the current amplitude; is the phase angle, indicating the starting position of the vibration.

[0144] In one embodiment, step S33: deriving the negative work calculation expression of the damping force in one cycle when dry friction damping force exists in the scissor suspension seat;

[0145]

[0146] Where W is the work done by the vibration system damping force in one cycle T; is the speed of the vibration system at time t; c is the equivalent damping of the general vibration system; A is the current amplitude; w is the angular frequency; is the phase angle, indicating the starting position of the vibration.

[0147] In one embodiment, step S33: deriving the work ΔE done by the friction force in one cycle of the vibration system of the scissor-type suspension seat when dry friction damping force exists in the scissor-type suspension seat:

[0148] ΔE=4F f A formula (15)

[0149] Where ΔE is the work done by friction in one cycle of the vibration system; F f is the friction force; A is the current amplitude of the vibration system.

[0150] In one embodiment, step S34: by combining equations (14) and (15), the negative work done by the damping force and the work done by the friction force are calculated, and the calculation expression of the equivalent damping of the general vibration system is obtained according to the equivalent viscous damping law, as shown in the following equation:

[0151]

[0152] Where c is the equivalent damping of the general vibration system; F f is the friction force; A is the current amplitude of the vibration system; w is the angular velocity; A is the current amplitude.

[0153] In one embodiment, the step S4: obtaining the equivalent damping calculation expression of the scissor-type suspension seat according to the equivalent damping calculation expression of the scissor-type suspension seat vibration system and the equivalent damping calculation expression of the general vibration system is specifically implemented as follows:

[0154] Combining equations (9) and (16), we can obtain the equivalent damping C of the scissor suspension seat vibration system: S The calculation expression is as follows:

[0155]

[0156] The structural parameters of this model of scissor suspension seat are shown in Table 1:

[0157] Table 1 Structural parameters of a certain type of scissor suspension seat

[0158] <![CDATA[l1(mm)]]> <![CDATA[l2(mm)]]> μ α(°) θ(°) c(N·s / mm) 177.52 214.82 0.3 32.4 62.8 10

[0159] Combining the structural parameters of the scissor suspension seat in Table 1 and formula (17), the equivalent damping of the simplified model of the scissor suspension structure of this model is calculated to be 11.193 N·s / mm.

[0160] Based on the above data, a multi-body dynamics model of the seat is established, such as Figure 6 shown.

[0161] Similarly, according to the above method, different gear damping values ​​are selected, and the calculated equivalent damping values ​​are substituted into the simulation calculation. The obtained seat resonance frequency and transmissibility change law with different damping gears are compared with the experimental results. Figure 7-Figure 8 shown.

[0162] The equivalent damping value is not used in the dynamics simulation. The calculated dynamics simulation results are as follows: Figure 9-10 shown.

[0163] By comparing the calculation results and adding the equivalent damping value identified by the above method, the error of the calculated result of the resonance frequency obtained by the dynamic simulation can be reduced by 10.9%, and the error of the calculated result of the transmissibility can be reduced by 15.3%.

[0164] In summary, the damping identification method of the scissor suspension seat proposed in this application can improve the accuracy of the simulation model and make the result error of the dynamic simulation calculation smaller. It can provide guidance for the suspension design of air suspension seats, improve the dynamic performance of seat products, and help improve the riding comfort of passengers and enhance product competitiveness.

[0165] In a second aspect, the present application provides a system for identifying friction damping of a scissor suspension seat, comprising:

[0166] A simplified model acquisition module is used to simplify the scissor-type suspension structure of the seat and obtain a simplified model of the scissor-type suspension structure;

[0167] The scissor suspension system equivalent damping calculation module is connected to the simplified model acquisition module for performing force analysis on the simplified model of the scissor suspension structure to obtain an equivalent damping calculation expression for the scissor suspension seat vibration system;

[0168] General vibration system equivalent damping calculation module, used to obtain the equivalent damping calculation expression of the general vibration system;

[0169] The scissor-type suspension seat equivalent damping calculation module is communicatively connected with the scissor-type suspension system equivalent damping calculation module and the general vibration system equivalent damping calculation module, and is used for obtaining the equivalent damping calculation expression of the scissor-type suspension seat according to the equivalent damping calculation expression of the scissor-type suspension seat vibration system and the equivalent damping calculation expression of the general vibration system.

[0170] In one embodiment, the equivalent damping calculation module of the scissor suspension system includes:

[0171] Overall force analysis unit, used to establish the overall force balance equation of the seat;

[0172] A vibration-related force acquisition unit, used to obtain calculation expressions of air spring force, damper damping force and friction force;

[0173] Local force analysis unit, used to obtain the force balance equation of the two shear rods of the seat scissor suspension;

[0174] A suspension system vibration differential equation acquisition unit is connected to the overall force analysis unit, the vibration-related force acquisition unit and the local force analysis unit, and is used to combine the overall force balance equation of the seat with the calculation expressions of the air spring force, the damping force of the damper and the friction force, and the force balance equation of the two shear rods of the scissor suspension of the seat, so as to obtain a general form of vibration differential equation of the scissor suspension seat vibration system under the simple harmonic excitation;

[0175] A coefficient comparison unit is connected to the suspension system vibration differential equation acquisition unit for performing coefficient comparison on the obtained general form of the vibration differential equation to obtain a damping ratio calculation expression;

[0176] The suspension system equivalent damping calculation unit is connected to the coefficient comparison unit for simultaneously calculating the damping ratio and the damping coefficient to obtain the equivalent damping calculation expression of the scissor suspension seat vibration system.

[0177] Among them, the functional implementation of each module in the above-mentioned scissor-type suspension seat friction damping identification system corresponds to the various steps in the above-mentioned scissor-type suspension seat damping identification method embodiment, and its functions and implementation processes will not be repeated here one by one.

[0178] On the third aspect, an embodiment of the present application provides a device for identifying the friction damping of a scissor-type suspension seat. The device for identifying the friction damping of a scissor-type suspension seat can be a personal computer (PC), a laptop computer, a server, or other device with data processing capabilities.

[0179] The communication interface includes an input / output (I / O) interface, a physical interface, and a logical interface, etc., which are used to interconnect the devices inside the scissor-type suspension seat friction damping identification device, and an interface used to interconnect the scissor-type suspension seat friction damping identification device with other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, an optical fiber interface, an ATM interface, etc.; the user device can be a display, a keyboard, etc.

[0180] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0181] The processor may be a general-purpose processor, which may call the identification program of the friction damping of the scissor-type suspension seat stored in the memory and execute the damping identification method of the scissor-type suspension seat provided in the embodiment of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the identification program of the friction damping of the scissor-type suspension seat is called may refer to the various embodiments of the damping identification method of the scissor-type suspension seat of the present application, which will not be described in detail here.

[0182] In a fourth aspect, an embodiment of the present application also provides a readable storage medium.

[0183] The readable storage medium of the present application stores a program for identifying the friction damping of a scissor-type suspension seat, wherein when the program for identifying the friction damping of a scissor-type suspension seat is executed by a processor, the steps of the damping identification method of the scissor-type suspension seat as described above are implemented.

[0184] Among them, the method implemented when the identification program of the friction damping of the scissor-type suspension seat is executed can refer to the various embodiments of the damping identification method of the scissor-type suspension seat of the present application, and will not be repeated here.

[0185] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0186] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, disk, CD) as described above, and includes a number of instructions for a terminal device to execute the methods described in each embodiment of the present application.

[0187] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A damping identification method for a scissor suspension seat, characterized in that: The following steps are involved: Simplify the scissor suspension structure of the seat to obtain a simplified model of the scissor suspension structure; Perform stress analysis on the simplified model of the scissor suspension structure and obtain the equivalent damping calculation expression of the scissor suspension seat vibration system; Obtain the equivalent damping calculation expression for general vibration systems; According to the equivalent damping calculation expression of the scissor-type suspension seat vibration system and the equivalent damping calculation expression of the general vibration system, the equivalent damping calculation expression of the scissor-type suspension seat is obtained.

2. The damping identification method of the scissor suspension seat according to claim 1, characterized in that: The stress analysis of the simplified model of the scissor suspension structure is performed to obtain an equivalent damping calculation expression for the scissor suspension seat vibration system, specifically comprising the following steps: Establish the overall force balance equation of the seat; Obtain calculation expressions for air spring force, damper damping force, and friction force; Obtain the force equilibrium equations of the two shear rods of the seat scissor suspension; The overall force balance equation of the seat and the calculation expressions of the air spring force, damping force of the damper and friction force as well as the force balance equation of the two shear rods of the scissor suspension of the seat are combined to obtain the general form of the vibration differential equation of the scissor suspension seat vibration system under the simple harmonic excitation. Compare the coefficients of the obtained general form of vibration differential equation and obtain the damping ratio calculation expression; The calculation expression of damping ratio and damping coefficient is combined to obtain the equivalent damping calculation expression of scissor suspension seat vibration system.

3. The damping identification method of the scissor suspension seat according to claim 2, characterized in that: The overall force balance equation of the seat is as follows: ∑X=0,F cx +F bx -F d cosθ=0 In the formula, ∑X is the force balance equation of the vibration system in the x direction; ∑Y is the force balance equation of the vibration system in the y direction; ∑M c The overall moment balance equation of the simplified model of the scissor suspension structure; F cx is the X-direction force at point C; F bx is the X-direction force acting on point B; F d is the damping force of the damper; F cy is the Y-direction force at point C; F by is the Y-direction force at point B; m is the overall mass of the suspension.

4. The damping identification method of a scissor suspension seat according to claim 2, characterized in that: The method of obtaining the force balance equation of the two shear rods of the seat scissor suspension specifically includes the following steps: The force analysis of the first shear bar is performed, and the force balance equation of the first shear bar is obtained as shown below: ∑X=0,F ox -F' ax +F bx =0 ΣY=0,F by +F' oy -F ay =0 ∑M O =0,F ax l1 sinα+F ay l1 cosα+F by l2 cosα+F by l2 sinα=0 In the formula, ∑X is the force balance equation in the x direction; ∑Y is the force balance equation in the y direction; ∑M o The force balance equation of the center point of AB rod of the simplified scissor suspension structure model; F ox is the force in the X direction at point O; F ax is the force in the X direction at point A; F bx is the force in the X direction at point B; F by is the force in the Y direction at point B; F oy is the force in the X direction at point O; F ay is the force in the Y direction at point A; l1 is the first length variable of the vibration system; l2 is the second length variable of the vibration system; The force analysis of the second shear rod shows that the force equilibrium equation of the second shear rod is as follows: ΣX=0,F cx -F ox +F dx =0 ΣY=0,F cy -F dy -F oy -F k =0 ∑M O =0,F cx l2 sinα-F cy l2 cosα-F dx l1 sinα-F dy l1 cosα=0 In the formula, ∑X is the force balance equation in the x direction; ∑Y is the force balance equation in the y direction; ∑M o The force balance equation of the center point of CD rod of the simplified scissor suspension structure is: cx is the force in the X direction at point C, F ox is the force in the X direction at point O, F dx is the force in the X direction at point D, F cy is the force in the Y direction at point C, F dy is the force in the Y direction at point D, F oy is the force in the Y direction at point O, F k is the air spring force.

5. The damping identification method of a scissor suspension seat according to claim 2, characterized in that: The damping ratio calculation expression is shown in the following formula: Where ξ is the damping ratio; ω0 is the initial angular velocity, m is the overall mass of the suspension; α is the angle between the first shear bar and the seat bottom plate; θ is the angle between the second shear rod and the seat bottom plate; l1 is the first length variable of the vibration system; l2 is the second length variable of the vibration system; c is the equivalent damping of the general vibration system.

6. The damping identification method of a scissor-type suspension seat according to claim 2, characterized in that: The equivalent damping calculation expression of the scissor suspension seat vibration system is as follows: In the formula, C S is the equivalent damping of the scissor suspension seat vibration system; c is the equivalent damping of the general vibration system; α is the angle between the first shear rod and the seat bottom plate; θ is the angle between the second shear rod and the seat bottom plate; l1 is the first length variable of the vibration system; l2 is the second length variable of the vibration system.

7. The damping identification method of a scissor-type suspension seat according to claim 1, characterized in that: The obtaining of the equivalent damping calculation expression of the general vibration system specifically comprises the following steps: Obtain the differential equation of motion for a mass-spring system with dry friction damping in a single degree of freedom; The initial displacement excitation and steady-state displacement response of the mass-spring system are given; Derive the calculation expressions for the negative work done by the damping force and the work done by the friction force in one cycle of the scissor suspension seat when dry friction damping force exists in the scissor suspension seat; The negative work done by the damping force and the work done by the friction force are calculated together, and the calculation expression of the equivalent damping of the general vibration system is obtained according to the equivalent viscous damping law.

8. The damping identification method of a scissor-type suspension seat according to claim 7, characterized in that: The equivalent damping calculation expression is shown in the following formula: Where c is the equivalent damping of the general vibration system; F f is the friction force; A is the current amplitude of the vibration system; w is the angular velocity; A is the current amplitude.

9. A friction damping identification system for a scissor suspension seat, characterized in that: include: A simplified model acquisition module is used to simplify the scissor-type suspension structure of the seat and obtain a simplified model of the scissor-type suspension structure; The scissor suspension system equivalent damping calculation module is connected to the simplified model acquisition module for performing force analysis on the simplified model of the scissor suspension structure to obtain an equivalent damping calculation expression for the scissor suspension seat vibration system; General vibration system equivalent damping calculation module, used to obtain the equivalent damping calculation expression of the general vibration system; The scissor-type suspension seat equivalent damping calculation module is communicatively connected with the scissor-type suspension system equivalent damping calculation module and the general vibration system equivalent damping calculation module, and is used for obtaining the equivalent damping calculation expression of the scissor-type suspension seat according to the equivalent damping calculation expression of the scissor-type suspension seat vibration system and the equivalent damping calculation expression of the general vibration system.

10. The friction damping identification system of the scissor suspension seat according to claim 9, characterized in that: The equivalent damping calculation module of the scissor suspension system includes: Overall force analysis unit, used to establish the overall force balance equation of the seat; A vibration-related force acquisition unit, used to obtain calculation expressions of air spring force, damper damping force and friction force; Local force analysis unit, used to obtain the force balance equation of the two shear rods of the seat scissor suspension; A suspension system vibration differential equation acquisition unit is connected to the overall force analysis unit, the vibration-related force acquisition unit and the local force analysis unit, and is used to combine the overall force balance equation of the seat with the calculation expressions of the air spring force, the damping force of the damper and the friction force, and the force balance equation of the two shear rods of the scissor suspension of the seat, so as to obtain a general form of vibration differential equation of the scissor suspension seat vibration system under the simple harmonic excitation; A coefficient comparison unit is connected to the suspension system vibration differential equation acquisition unit for performing coefficient comparison on the obtained general form of the vibration differential equation to obtain a damping ratio calculation expression; The suspension system equivalent damping calculation unit is connected to the coefficient comparison unit for simultaneously calculating the damping ratio and the damping coefficient to obtain the equivalent damping calculation expression of the scissor suspension seat vibration system.

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