A method of modeling an electromechanically active suspension

Abstract

The application discloses a kind of electromechanical active suspension modeling method, comprising: 1) according to the application scene of suspension, suspension is equivalent to a single degree of freedom vibration system;2) through static dynamics experiment, the torsional moment of torsion bar spring is approximately equivalent to vertical force;3) assume that spring mass is stationary, the excitation received by guide wheel is equivalent to external excitation minus the excitation response of spring mass;4) kinematics modeling is carried out to mechanism, the velocity, angular velocity, angular acceleration of each component and the acceleration at the mass center of component are calculated;5) dynamics modeling is carried out to mechanism, and dynamic equation is established, to obtain the vertical force of connecting rod-swing arm part to spring mass;6) the acceleration of spring mass is calculated;7) the initial value required by numerical integration method is calculated kinematics modeling is needed.The mathematical model of electromechanical active suspension is established, so as to provide effective theoretical guidance for the control, parameter optimization and the like of suspension.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of suspension dynamics, and particularly relates to a modeling method of an electromechanical active suspension. BACKGROUND

[0002] The electromechanical suspension, also known as electromagnetic suspension, is a new suspension mechanism different from the traditional active suspension of a vehicle, and has a wide application prospect in heavy-duty vehicles. The heavy-duty vehicles usually run on complex and poor road conditions, and the vibration generated by the vehicle chassis during running seriously affects the off-road mobility and ride comfort of the vehicle. The active suspension can output a control force in real time according to the need of vehicle chassis vibration control, so as to effectively control the vibration of the vehicle chassis within the ideal range. Therefore, it is necessary to configure a new electromechanical active suspension on the new generation of heavy-duty vehicles. The electromechanical active suspension uses electric energy as the energy transmission link. The motor of the electromechanical suspension converts the electric energy of the vehicle into kinetic energy, and transmits the force or torque output by the motor to the sprung mass or unsprung mass through mechanical components (gear rack or planetary reducer), thereby realizing active control of the motor; when the energy flows in the opposite direction, semi-active control can be realized by adjusting the energy recovery efficiency.

[0003] At present, the electromechanical active suspension does not have a mathematical model in the field of kinematics and dynamics, so that when studying the dynamic characteristics of the system, the relationship between the inherent parameters of the system and the dynamic response cannot be determined, and thus the semi-active control and active control of the suspension cannot be accurately performed. SUMMARY

[0004] The present application is to solve the above-mentioned problems existing in the prior art, and proposes a modeling method of an electromechanical active suspension, so as to establish a mathematical model of the electromechanical active suspension, and build the relationship between the system parameters and the dynamic response characteristics, thereby providing effective theoretical guidance for the semi-active control, active control and vibration mechanism research of the suspension.

[0005] In order to achieve the above-mentioned application purposes, the present application adopts the following technical solutions:

[0006] The electromechanical active suspension modeling method has the following steps:

[0007] 1) Assuming that the external excitation is directly applied to the guide wheel of the electromechanical active suspension mechanism, so as to equivalent the electromechanical active suspension mechanism to a single degree of freedom vibration system;

[0008] 2) Through a static dynamics experiment, the torsional torque of the torsion bar spring applied to the sprung mass in the electromechanical active suspension mechanism is equivalent to the vertical force of the coil spring, and the equivalent stiffness of the coil spring is calculated;

[0009] 3) Assuming that the electromechanical active suspension mechanism is working, the sprung mass M always remains stationary, the excitation received by the guide wheel is equivalent to the external excitation minus the excitation response value of the sprung mass;

[0010] 4) Kinematic modeling of the electromechanical active suspension mechanism:

[0011] 4.1) Taking the fixed point of the torsion bar spring and the sprung mass as the origin A , the positive direction of the real axis is the horizontal direction to the right, and the positive direction of the imaginary axis is the vertical direction upward, a Newton-Euler coordinate system is established;

[0012] 4.2) Calculate the velocity, angular velocity, angular acceleration of each component in the electromechanical active suspension mechanism, and the vertical acceleration and horizontal acceleration at the center of mass of each component;

[0013] 5) Dynamic modeling of the electromechanical active suspension mechanism:

[0014] 5.1) Select the connecting rod BC and the swing arm CD as a group of basic rod systems, and establish the dynamic equation from the kinematic information of each component;

[0015] 5.2) According to the dynamic equation, the contact constraint force at each hinge point is obtained, and the vertical component force of the connecting rod-swing arm part on the sprung mass is obtained;

[0016] 6) According to the vertical support force of the torsion bar spring and the vertical force of the connecting rod-swing arm part on the sprung mass, the vertical acceleration of the sprung mass is calculated by using Newton's second law;

[0017] 7) The velocity value and displacement value of the sprung mass are calculated by the numerical integration method, so as to obtain the initial data required by the kinematic modeling.

[0018] The electromechanical active suspension modeling method provided by the application has the characteristics that step 4.2) includes the following process:

[0019] (a) Use formula (1) to establish a vector from the origin A of the Newton-Euler coordinate system A to the center of mass G of the swing arm Expression:

[0020] (1)

[0021] In formula (1), is a vector from the origin A to the guide wheel B; is a vector from the guide wheel B to the hinge point C of the connecting rod and the swing arm; is a vector from the hinge point C of the connecting rod and the swing arm to the center of mass G of the swing arm;

[0022] Using Euler's formula, the equation (1) is expanded and simplified in the complex coordinate system to obtain equation (2):

[0023] (2)

[0024] In equation (2), is the horizontal displacement of the swing arm centroid G, is the vertical displacement of the swing arm centroid G; is the length of the balance elbow AB; is the length of the connecting rod BC; is the distance from the connecting rod and swing arm hinge point C to the swing arm centroid G; is the included angle between the balance elbow AB and the connecting rod BC; is the included angle between the connecting rod BC and the swing arm CD; is the included angle between the balance elbow AB and the horizontal direction;

[0025] The second derivative of time t is taken on both sides of equation (2) to obtain equation (3):

[0026] (3)

[0027] In equation (3), is the horizontal acceleration of the swing arm centroid G; is the vertical acceleration of the swing arm centroid G; is the first derivative of the included angle between the balance elbow AB and the connecting rod BC ; is the first derivative of the included angle between the connecting rod BC and the swing arm CD ; is the first derivative of the included angle between the balance elbow AB and the horizontal direction ; is the second derivative of the included angle between the balance elbow AB and the connecting rod BC ; is the second derivative of the included angle between the connecting rod BC and the swing arm CD ; is the second derivative of the included angle between the balance elbow AB and the horizontal direction ;

[0028] (b) The expression of the vector from the origin A to the connecting rod BC centroid F is established using equation (4):

[0029] (4)

[0030] In equation (4), is the vector from the guide wheel B to the connecting rod BC centroid F;

[0031] Expanding and simplifying equation (4) in the complex number coordinate system using Euler's formula, equation (5) is obtained:

[0032] (5)

[0033] In equation (5), is the horizontal acceleration of the center of mass F of the connecting rod BC; is the vertical acceleration of the center of mass F of the connecting rod BC;

[0034] (c) Construct a vector equation using equation (6):

[0035] (6)

[0036] In equation (6), is the vector from the origin A to the hinge point D of the swing arm and the sprung mass; is the vector from the hinge point D of the swing arm and the sprung mass to the hinge point C of the connecting rod BC and the swing arm CD;

[0037] Expanding and simplifying equation (6) in the complex number coordinate system using Euler's formula, equation (7) is obtained:

[0038] (7)

[0039] In equation (7), is the angle between the line AD connecting the origin A and the hinge point D of the swing arm and the sprung mass and the horizontal direction, is the length of the swing arm CD;

[0040] The angular velocity of the swing arm CD is obtained using equation (8) :

[0041] (8)

[0042] In equation (8), is the angular velocity of the balance elbow AB; and is obtained from equation (9):

[0043] (9)

[0044] In equation (9), is the vertical speed of the sprung mass, is the vertical speed of the guide wheel;

[0045] The angular velocity of the connecting rod BC is obtained using equation (10) :

[0046] (10)

[0047] The angular acceleration of the swing arm AB is obtained using equation (11) :

[0048] (11)

[0049] In equation (11), is the vertical acceleration of the guide wheel; is the vertical acceleration of the sprung mass;

[0050] (d) The vector relationship is constructed using equation (12):

[0051] (12)

[0052] Equation (12) is rewritten in complex form as shown in equation (13):

[0053] (13)

[0054] In equation (13), i denotes the imaginary unit;

[0055] Differentiating equation (13) gives equation (14):

[0056] (14)

[0057] Differentiating equation (14) gives equation (15):

[0058] (15)

[0059] In equation (15), is the angular acceleration of the connecting rod BC; is the angular acceleration of the rocker arm CD;

[0060] Multiplying both sides of equation (15) by the angular acceleration of the rocker arm CD is obtained using equation (16) :

[0061] (16)

[0062] (e) Multiplying both sides of equation (15) by the angular acceleration of the connecting rod BC is obtained using equation (17) :

[0063] (17).

[0064] The dynamic equations in step 5.1) include:

[0065] According to Newton's second law and the theorem of moment of momentum, the dynamics equations of the connecting rod BC are constructed by using formula (18)-formula (20):

[0066] (18)

[0067] (19)

[0068] (20)

[0069] According to Newton's second law and the theorem of moment of momentum, the dynamics equations of the swing arm CD are constructed by using formula (21)-formula (23):

[0070] (21)

[0071] (22)

[0072] (23)

[0073] In formula (18)-formula (23), 、 is the component force of the contact constraint force applied on the connecting rod BC at the hinge point B in the vertical direction and the horizontal direction; 、 is the component force of the contact constraint force applied on the swing arm CD at the hinge point C in the vertical direction and the horizontal direction; 、 is the component force of the contact constraint force applied on the connecting rod BC at the hinge point C in the vertical direction and the horizontal direction; wherein, and are action and reaction forces, equal in size and opposite in direction; and are action and reaction forces, equal in size and opposite in direction, 、 is the force of the contact constraint force applied on the swing arm CD at the hinge point D in the vertical direction and the horizontal direction;

[0074] In formula (18)-formula (23), is the component force of the contact constraint force applied on the connecting rod BC at the hinge point B in the direction perpendicular to the connecting rod BC, is the component force of the contact constraint force applied on the connecting rod BC at the hinge point C in the direction perpendicular to the connecting rod BC; is the component force of the contact constraint force applied on the swing arm CD at the hinge point C in the direction perpendicular to the swing arm CD, is the component force of the contact constraint force applied on the swing arm CD at the hinge point D in the direction perpendicular to the swing arm CD; the torsional moment provided to the electric motor, the friction moment experienced by the electric motor during operation; the mass of the connecting rod BC; the moment of inertia of the connecting rod BC about its center of mass F; the mass of the swing arm CD; the moment of inertia of the swing arm CD about its center of mass G.

[0075] Step 5.2) comprises:

[0076] The dynamic equation is rewritten in the matrix form as shown in equation (24):

[0077] (24)

[0078] In equation (24), is the cosine parameter, and ; is the sine parameter, and ;

[0079] Solving equation (24), the expression of the vertical component of the contact constraint force exerted on the swing arm CD at the hinge point D is obtained by equation (25):

[0080] (25)

[0081] In step 6), the acceleration of the sprung mass is obtained by equation (26):

[0082] (26)

[0083] In equation (26), is the vertical force of the equivalent helical spring measured by the static dynamics experiment, and is obtained by equation (27):

[0084] (27)

[0085] In equation (27), is the equivalent spring stiffness, is the change in distance between the guide wheel and the sprung mass, is the vertical support force of the spring at static equilibrium.

[0086] The electronic device comprises a memory and a processor, wherein the memory is configured to store a program supporting the processor to execute the electromechanical active suspension modeling method, and the processor is configured to execute the program stored in the memory. ​​

[0087] The application is a computer readable storage medium, and a computer program is stored on the computer readable storage medium.

[0088] Compared with the prior art, the application has the beneficial effects that:

[0089] 1. The application establishes a complete mathematical model of the electromechanical active suspension in the kinematics field and the dynamics field, thereby connecting the system parameters and the dynamic response, and providing a theoretical basis for controlling and optimizing the parameters of the suspension mechanism.

[0090] 2. The mathematical model of the electromechanical active suspension established by the application completely and comprehensively describes the kinematic characteristics and the dynamic characteristics of the electromechanical active suspension, including the velocity, the angular velocity, the angular acceleration of each component, the velocity and the acceleration at the center of mass of each component, and the constraint force at the coupling of each component, thereby providing complete kinematic and dynamic information for real-time prediction and analysis of the nonlinear vibration response of the suspension. BRIEF DESCRIPTION OF DRAWINGS

[0091] Figure 1 is a mathematical modeling flowchart of the electromechanical active suspension of the application;

[0092] Figure 2 is a structural diagram of the electromechanical active suspension of the application;

[0093] Figure 3 is a kinematic modeling diagram of the application;

[0094] Figure 4 is a dynamic modeling diagram of the application;

[0095] Figure 5a is a simulation result diagram of the sprung mass acceleration obtained by numerical calculation;

[0096] Figure 5b is a simulation result diagram of the sprung mass acceleration in the multi-body dynamics simulation software ADAMS. DETAILED DESCRIPTION

[0097] In this embodiment, in order to quantitatively study the control method and the working mechanism of the electromechanical active suspension, accurately predict and analyze the nonlinear vibration response of the suspension, a modeling method of the electromechanical active suspension is proposed, and the kinematic and dynamic models of the entire electromechanical active suspension are established, thereby being applicable to suspension control algorithms, parameter optimization, mechanism research and many other aspects, and being beneficial to quantitatively analyzing and studying the dynamic characteristics of the suspension system. Figure 1 As shown in the figure, the modeling method includes the following steps:

[0098] 1) The actual application scenario of the electromechanical active suspension and the structural characteristics of the mechanism make the electromechanical active suspension mechanism equivalent to a single degree of freedom vibration system, so that the external excitation is directly applied to the guide wheel of the electromechanical active suspension mechanism;

[0099] 2) The torsional moment of the torsion bar spring applied to the sprung mass in the electromechanical active suspension mechanism is equivalent to the vertical force of the coil spring through static dynamics experiment, and the equivalent stiffness is calculated;

[0100] 3) According to the relative motion analysis method, it is assumed that the sprung mass M always remains stationary when the electromechanical active suspension mechanism is working, so that the excitation received by the guide wheel is equivalent to the external excitation minus the excitation response value of the sprung mass;

[0101] 4) Kinematic modeling of the electromechanical active suspension mechanism:

[0102] 4.1) Taking the fixed point of the torsion bar spring and the sprung mass as the origin A , establishing the Newton-Euler coordinate system with the right direction in the horizontal direction as the positive direction of the real axis and the upward direction in the vertical direction as the positive direction of the imaginary axis;

[0103] 4.2) Calculate the velocity, angular velocity, angular acceleration of each component in the electromechanical active suspension mechanism, and the vertical acceleration and horizontal acceleration at the center of mass of each component;

[0104] 4.2.a) Use formula (1) to establish the expression of the vector A pointing from the origin A of the Newton-Euler coordinate system to the center of mass G of the swing arm:

[0105] (1)

[0106] In formula (1), is the vector from the origin A to the guide wheel B; is the vector from the guide wheel B to the hinge point C of the connecting rod and the swing arm; is the vector from the hinge point C of the connecting rod and the swing arm to the center of mass G of the swing arm;

[0107] Expand and simplify formula (1) in the complex coordinate system using Euler's formula to obtain formula (2):

[0108] (2)

[0109] In formula (2), is the horizontal displacement of the center of mass G of the swing arm, is the vertical displacement of the center of mass G of the swing arm; is the length of the balance elbow AB; is the length of the connecting rod BC; ​Let C be the distance between the hinge point C of the connecting rod and the swing arm and the center of mass G of the swing arm; To balance the angle between elbow AB and connecting rod BC; The angle between link BC and swing arm CD; To balance the angle between elbow AB and the horizontal direction;

[0110] Taking the second derivative of both sides of equation (2) with respect to time t, we obtain equation (3):

[0111] (3)

[0112] In equation (3), Let G be the horizontal acceleration of the center of mass of the swing arm; Let G be the vertical acceleration of the center of mass of the swing arm; To balance the angle between elbow AB and connecting rod BC The first derivative; The angle between link BC and swing arm CD The first derivative; To balance the angle between elbow AB and the horizontal direction The first derivative; To balance the angle between elbow AB and connecting rod BC The second derivative; The angle between link BC and swing arm CD The second derivative; To balance the angle between elbow AB and the horizontal direction The second derivative;

[0113] 4.2.b) Using equation (4), establish the vector pointing from the origin A to the centroid F of link BC. The expression:

[0114] (4)

[0115] In equation (4), The vector pointing from guide wheel B to the center of mass F of connecting rod BC;

[0116] By expanding and simplifying equation (4) in a complex coordinate system using Euler's formula, we obtain equation (5):

[0117] (5)

[0118] In equation (5), Let F be the horizontal acceleration of the center of mass F of connecting rod BC; Let F be the vertical acceleration of the center of mass F of connecting rod BC;

[0119] 4.2.c) Construct the vector equation using equation (6):

[0120] (6)

[0121] In formula (6), is a vector from the origin A to the hinge point D of the swing arm and the sprung mass; is a vector from the hinge point D of the swing arm and the sprung mass to the hinge point C of the connecting rod BC and the swing arm CD;

[0122] Formula (6) is expanded and simplified in the complex coordinate system by using Euler's formula, so as to obtain formula (7):

[0123] (7)

[0124] In formula (7), is the included angle between the line AD of the origin A and the hinge point D of the swing arm and the sprung mass and the horizontal direction, is the length of the swing arm CD;

[0125] The angular velocity of the swing arm CD is obtained by formula (8) :

[0126] (8)

[0127] In formula (8), is the angular velocity of the balance elbow AB; and is obtained by formula (9):

[0128] (9)

[0129] In formula (9), is the vertical speed of the sprung mass, is the vertical speed of the guide wheel;

[0130] The angular velocity of the connecting rod BC is obtained by formula (10) :

[0131] (10)

[0132] The angular acceleration of the swing arm AB is obtained by formula (11) :

[0133] (11)

[0134] In formula (11), is the acceleration of the guide wheel; is the acceleration of the sprung mass;

[0135] 4.2.d) Construct the vector relationship formula by formula (12):

[0136] (12)

[0137] Rewrite formula (12) into a complex form as shown in formula (13):

[0138] (13)

[0139] In formula (13), i represents an imaginary unit;

[0140] Derive formula (13) to obtain formula (14):

[0141] (14)

[0142] Derive formula (14) to obtain formula (15):

[0143] (15)

[0144] In formula (15), is the angular acceleration of connecting rod BC; is the angular acceleration of swing arm CD;

[0145] Multiply both sides of formula (15) by , so that the angular acceleration of swing arm CD is obtained by formula (16) :

[0146] (16)

[0147] 4.2.e) Multiply both sides of formula (15) by

[0148] After rearrangement, the angular acceleration of connecting rod BC is obtained :

[0149] (17)

[0150] 5) Dynamic modeling of electromechanically active suspension mechanism:

[0151] 5.1) As shown in Figure 4 , connecting rod BC and swing arm CD are selected as a group of basic linkage, and dynamic equations are established from the kinematic information of each component;

[0152] According to Newton's second law and the theorem of moment of momentum, the dynamic equation of connecting rod BC is constructed by formula (18)-formula (20):

[0153] (18)

[0154] (19)

[0155] (20)

[0156] According to Newton's second law and the theorem of moment of momentum, the dynamic equation of the swing arm CD is constructed by using formula (21)-formula (23):

[0157] (21)

[0158] (22)

[0159] (23)

[0160] In formula (18)-formula (23), 、 is the component force of the contact constraint force applied on the connecting rod BC at the hinge point B in the vertical direction and the horizontal direction; 、 is the component force of the contact constraint force applied on the swing arm CD at the hinge point C in the vertical direction and the horizontal direction; 、 is the component force of the contact constraint force applied on the connecting rod BC at the hinge point C in the vertical direction and the horizontal direction; wherein, and are action and reaction forces, equal in size and opposite in direction; and are action and reaction forces, equal in size and opposite in direction, 、 is the force of the contact constraint force applied on the swing arm CD at the hinge point D in the vertical direction and the horizontal direction;

[0161] In formula (18)-formula (23), is the component force of the contact constraint force applied on the connecting rod BC at the hinge point B in the direction perpendicular to the BC connecting rod, is the component force of the contact constraint force applied on the connecting rod BC at the hinge point C in the direction perpendicular to the connecting rod BC; is the component force of the contact constraint force applied on the swing arm CD at the hinge point C in the direction perpendicular to the swing arm CD, is the component force of the contact constraint force applied on the swing arm CD at the hinge point D in the direction perpendicular to the swing arm CD; is the torsional torque provided by the motor, is the friction torque suffered by the motor during operation. is the mass of the connecting rod BC; is the moment of inertia of the connecting rod BC around its center of mass F point; is the mass of the swing arm CD; is the moment of inertia of the swing arm CD around its center of mass G point.

[0162] The dynamic equations are rewritten in matrix form as shown in equation (24):

[0163] (twenty four)

[0164] In equation (24), For cosine parameters, ; The parameter is sinusoidal. .

[0165] 5.2) The unknown constraint forces at each hinge are obtained from the dynamic equations, and thus the vertical force exerted by the link-swing arm on the sprung mass is obtained.

[0166] Solving the linear equations represented by equation (24), we obtain the vertical component of the contact constraint force applied to the swing arm CD at hinge point D. The expression is:

[0167] Based on the vertical support force of the torsion bar spring and the vertical force exerted by the connecting rod-swing arm on the sponge mass, the vertical acceleration of the sponge mass is calculated using Newton's second law.

[0168] The acceleration of the sprung mass is obtained using equation (25). :

[0169] (25)

[0170] In equation (25), The torsional moment of the torsion bar spring applied to the spring-loaded mass measured in step 2) is equivalent to the vertical force of the helical spring, and is obtained from equation (26):

[0171] (26)

[0172] In equation (26), For equivalent spring stiffness, This refers to the change in distance between the guide wheel and the sprung mass. This is the vertical supporting force of the spring when it is in static equilibrium.

[0173] 7) The velocity and displacement of the sprung mass can be calculated using the numerical integration module, thus obtaining the initial values ​​required for kinematic modeling;

[0174] Before performing kinematic modeling, it is necessary to numerically integrate the acceleration response obtained from the dynamic modeling to obtain the corresponding velocity and displacement, thereby performing initial numerical calculations of the kinematics:

[0175] From the angular relationship, we can obtain equation (27):

[0176] (27)

[0177] In formula (27), BD is the length of the line connecting the center point B of the guide wheel and the hinge point D of the spring mass and the swing arm CD, is the length of the balance elbow AB, is the angle between the balance elbow AB and the horizontal direction, is the displacement of the spring mass in the vertical direction, is the displacement of the guide wheel in the vertical direction, is the distance between the spring mass and the guide wheel in the vertical direction when the suspension mechanism is in the balanced position.

[0178] According to the cosine theorem, in triangle ABD, we have:

[0179] (28)

[0180] In formula (28), BD is the length of the line connecting the center point B of the guide wheel and the hinge point D of the spring mass and the swing arm CD, AD is the length of the line connecting the hinge point A of the balance elbow AB and the hinge point D of the spring mass and the swing arm CD, is the angle between AD and the horizontal direction.

[0181] According to the cosine theorem, in triangle BCD, we have:

[0182] (29)

[0183] In formula (29), BC is the length of the connecting rod, is the angle between the connecting rod BC and the swing arm CD, is the length of the connecting rod BC, is the length of the swing arm CD.

[0184] According to the cosine theorem, in triangle ABD, we have:

[0185] (30)

[0186] In formula (30), is the angle between the balance elbow AB and the line BD.

[0187] According to the cosine theorem, in triangle CBD, we have:

[0188] (31)

[0189] In formula (31), is the angle between the connecting rod BC and the line BD. Then:

[0190] (32)

[0191] In formula (31) Balance the angle between elbow AB and connecting rod BC.

[0192] As shown in Figure 2 , the electromechanical active suspension of the present application mainly consists of balance elbow assembly 1, guide wheel 2, connecting rod assembly 3, electromechanical actuator, etc. The motor of the suspension uses a brushless DC motor, which together with a reducer forms an electromechanical actuator; the elastic element uses a torsion bar spring commonly used on heavy-duty vehicles; the guide mechanism is a connecting rod assembly, including a balance elbow, a connecting rod and a rocker arm. The electromechanical actuator and one end of the torsion bar spring are fixed to the vehicle body through bolts, positioning pins and positioning grooves, and are connected to the wheel through the connecting rod assembly. The connecting rod mechanism converts the vertical relative motion between the wheel and the vehicle body into the rotational motion of the electromechanical actuator through the rocker arm.

[0193] As shown in Figure 3 , it is a kinematic modeling diagram of the present application; taking the fixed point of the torsion bar spring and the spring mass as the origin A, taking the horizontal direction to the right as the positive direction of the real axis, and taking the vertical direction upward as the positive direction of the imaginary axis, a Newton-Euler coordinate system is established, AB is the balance elbow, BC is the connecting rod, CD is the rocker arm, E point is the center of mass of the balance elbow AB, F point is the center of mass of the connecting rod BC, G point is the center of mass of the rocker arm CD, M represents the spring mass, is the angle between the balance elbow AB and the horizontal direction, is the angle between the line AD connecting the two points of the hinge point A of the balance elbow AB and the hinge point D of the rocker arm CD of the spring mass M and the horizontal direction, is the angle between the rocker arm AB and the connecting rod BC, is the angle between the connecting rod BC and the rocker arm CD.

[0194] As shown in Figure 4 , it is a dynamic modeling diagram of the present application.

[0195] As shown in Figure 5a , the simulation implementation of the above theoretical modeling analysis method in the numerical calculation simulation software Simulink is given, the external excitation applied on the guide wheel is a sine excitation (amplitude of 80mm, frequency of 1Hz), the horizontal axis in the figure is time, and the vertical axis is the vertical acceleration response of the spring mass.

[0196] As shown in Figure 5b , after building the physical model of the electromechanical active suspension in the multi-body dynamics simulation software ADAMS, the same conditions as in the above Simulink simulation software are applied, and the corresponding spring mass vertical acceleration response curve is obtained. It can be seen that the trend is similar to the theoretical calculation result given in Figure 5a .

[0197] In this embodiment, an electronic device includes a memory for storing a program supporting a processor to perform the above-mentioned method for modeling an electromechanical active suspension, and the processor is configured to execute the program stored in the memory.

[0198] In this embodiment, a computer readable storage medium has a computer program stored thereon, and the computer program is run by a processor to perform the steps of the above-mentioned method for modeling an electromechanical active suspension.

Claims

1. A method of modeling an electromechanically active suspension, characterized by, The method comprises the following steps: 1) assuming that the external excitation is directly applied to the guide wheel of the electromechanical active suspension mechanism, so as to equivalently regard the electromechanical active suspension mechanism as a single degree of freedom vibration system; 2) through a static dynamics experiment, equivalently regarding the torsional moment of the torsion bar spring applied to the sprung mass in the electromechanical active suspension mechanism as the vertical force of the coil spring, and obtaining the equivalent stiffness of the coil spring; 3) assuming that the sprung mass M always remains stationary when the electromechanical active suspension mechanism is working, equivalently regarding the excitation received by the guide wheel as the external excitation minus the excitation response value of the sprung mass; 4) kinematically modeling the electromechanical active suspension mechanism: 4.1) Taking the fixed point of the torsion bar spring and the spring mass as the origin A A Newton-Euler coordinate system is established with the horizontal direction to the right as the positive direction of the real axis and the vertical direction upward as the positive direction of the imaginary axis. 4.2) calculating the velocity, angular velocity, angular acceleration of each component in the electromechanical active suspension mechanism, and the vertical and horizontal accelerations at the mass center of each component; (a) establishing from the origin of the Newton-Euler coordinate system A vector pointing to the center of mass of the swing arm G Expression: (1) In formula (1), is a vector from the origin A to the guide wheel B; is a vector from the guide wheel B to the hinge point C of the link and swing arm; is a vector from the hinge point C of the link and swing arm to the swing arm centroid G; Expanding and simplifying formula (1) in the complex coordinate system by using Euler formula, so as to obtain formula (2): (2) In formula (2), is the horizontal displacement of the swing arm centroid G, is the vertical displacement of the swing arm centroid G; is the length of the counterbalance elbow AB; is the length of the connecting rod BC; is the distance from the connecting rod and swing arm hinge point C to the swing arm centroid G; is the included angle between the counterbalance elbow AB and the connecting rod BC; is the included angle between the connecting rod BC and the swing arm CD; is the included angle between the counterbalance elbow AB and the horizontal direction; Deriving twice with respect to time t at both ends of formula (2), so as to obtain formula (3): (3) In equation (3), Let G be the horizontal acceleration of the center of mass of the swing arm; Let G be the vertical acceleration of the center of mass of the swing arm; To balance the angle between elbow AB and connecting rod BC The first derivative; The angle between link BC and swing arm CD The first derivative; To balance the angle between elbow AB and the horizontal direction The first derivative; To balance the angle between elbow AB and connecting rod BC The second derivative; The angle between link BC and swing arm CD The second derivative; To balance the angle between elbow AB and the horizontal direction The second derivative; (b) the vector from the origin A to the center of mass F of the link BC is established using the formula (4) the expression: (4) In formula (4), is the vector from the guide wheel B to the center of mass F of the link BC. Expanding and simplifying formula (4) in the complex coordinate system by using Euler formula, so as to obtain formula (5): (5) In formula (5), is the horizontal acceleration of the center of mass F of the connecting rod BC; is the vertical acceleration of the center of mass F of the connecting rod BC; (c) constructing a vector equation by using formula (6): (6) In formula (6), is a vector from the origin A to the hinge point D of the swing arm and the sprung mass; is a vector from the hinge point D of the swing arm and the sprung mass to the hinge point C of the connecting rod BC and the swing arm CD. Expanding and simplifying formula (6) in the complex coordinate system by using Euler formula, so as to obtain formula (7): (7) In formula (7), is the angle between the line AD connecting the origin A and the hinge point D of the swing arm and the spring mass, and the horizontal direction, is the length of the swing arm CD; The angular velocity of the swing arm CD is obtained using equation (8) : (8) In formula (8), is the angular velocity of the elbow AB; and from formula (9) we get: (9) In formula (9), is the vertical speed of the sprung mass, is the vertical speed of the guide wheel; The angular velocity of the connecting rod BC is obtained using equation (10) : (10) The angular acceleration of the swing arm AB is obtained using equation (11) : (11) In formula (11), vertical acceleration of the guide wheel; vertical acceleration of the sprung mass; (d) constructing a vector relationship by using formula (12): (12) Rewriting formula (12) into a complex number form as shown in formula (13): (13) In formula (13), i denotes the imaginary unit; Deriving formula (13), so as to obtain formula (14): (14) Deriving formula (14), so as to obtain formula (15): (15) In formula (15), is the angular acceleration of the connecting rod BC; is the angular acceleration of the rocker arm CD; Both sides of equation (15) are multiplied by Thus, using equation (16) the angular acceleration of the rocker CD is obtained : (16) (e) multiplying both sides of the equation of formula (15) by Thus, using formula (17) the angular acceleration of link BC is obtained : (17) 5) dynamically modeling the electromechanical active suspension mechanism: 5.1) selecting the connecting rod BC and the swing arm CD as a group of basic rod systems, and establishing a dynamics equation from the kinematic information of each component; 5.2) obtaining the contact constraint force at each hinge point according to the dynamics equation, so as to obtain the vertical component force of the connecting rod-swing arm part on the sprung mass; 6) according to the vertical support force of the torsion bar spring and the vertical force of the connecting rod-swing arm part on the sprung mass, calculating the vertical acceleration of the sprung mass by using Newton's second law; 7) calculating the velocity and displacement values of the sprung mass by using a numerical integration method, so as to obtain the initial data required by the kinematic modeling.

2. The electromechanically active suspension modeling method of claim 1, wherein, The dynamics equation in step 5.1) comprises: According to Newton's second law and the theorem of moment of momentum, constructing the dynamics equation of the connecting rod BC by using formula (18)-formula (20): (18) (19) (20) According to Newton's second law and the theorem of moment of momentum, constructing the dynamics equation of the swing arm CD by using formula (21)-formula (23): (21) (22) (23) in formula (18) - formula (23), , is the component of the contact constraint force applied at the hinge point B on the connecting rod BC in the vertical direction and the horizontal direction; , is the component of the contact constraint force applied at the hinge point C on the swing arm CD in the vertical direction and the horizontal direction; , is the component of the contact constraint force applied at the hinge point C on the connecting rod BC in the vertical direction and the horizontal direction; wherein, and are action and reaction forces, equal in size and opposite in direction; and are action and reaction forces, equal in size and opposite in direction, , is the force of the contact constraint force applied at the hinge point D on the swing arm CD in the vertical direction and the horizontal direction; in formulas (18) - (23), is the component of the contact constraint force applied at the hinge point B on the connecting rod BC in the direction perpendicular to the BC connecting rod, is the component of the contact constraint force applied at the hinge point C on the connecting rod BC in the direction perpendicular to the connecting rod BC; is the component of the contact constraint force applied at the hinge point C on the swing arm CD in the direction perpendicular to the swing arm CD, is the component of the contact constraint force applied at the hinge point D on the swing arm CD in the direction perpendicular to the swing arm CD; is the torque provided to the electric motor, is the friction torque experienced by the electric motor during operation; is the mass of the connecting rod BC; is the moment of inertia of the connecting rod BC about its center of mass point F; is the mass of the swing arm CD; is the moment of inertia of the swing arm CD about its center of mass point G.

3. The electromechanically active suspension modeling method of claim 2, wherein, Step 5.2) comprises: Rewriting the dynamics equation into a matrix form as shown in formula (24): (24) In formula (24), is a cosine parameter, and ; is a sine parameter, and ; Solving for equation (24) gives the vertical component of the contact constraint force exerted on the swing arm CD at the hinge point D using equation (25) the expression for (25)。 4. The electromechanically active suspension modeling method of claim 1, wherein, In step 6) the acceleration of the sprung mass is obtained using formula (26) : (26) In formula (26), The vertical force of the equivalent helical spring is measured in the static dynamics experiment, and is obtained from formula (27): (27) In formula (27), Ks is the equivalent spring rate, is the change in the distance between the guide wheel and the spring mass, is the vertical support force of the spring when in static equilibrium.

5. An electronic device comprising a memory and a processor, characterized in that The memory is used for storing a program supporting the processor to execute the electromechanical active suspension modeling method in any one of claims 1-4, and the processor is configured to execute the program stored in the memory.

6. A computer-readable storage medium having stored thereon a computer program, characterized in that The computer program is executed by the processor to perform the steps of the electromechanical active suspension modeling method in any one of claims 1-4.

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