Suspension parameter determination method and device, parameter adjustment method and device and equipment

Abstract

The invention relates to a suspension parameter determining method and device and a parameter adjusting method and device and equipment. The method comprises the steps that the displacement time response of a vehicle body in the target direction perpendicular to the ground under the deceleration strip working condition is obtained; the deceleration strip working condition represents that the vehicle travels through a target deceleration strip, the displacement time response is determined based on displacement excitation and speed excitation of the target deceleration strip to wheels and a dynamic model of a suspension system, and the displacement excitation and the speed excitation are determined based on size parameters of the target deceleration strip; determining a target suspension parameter of the suspension system by taking minimization of the first target parameter as a target; the first target parameter is determined based on the displacement time response and the suspension parameter, and the first target parameter at least represents the vibration response of the vehicle in the target direction under the deceleration strip working condition. According to the method, the possibility that the vehicle jumps greatly due to violent oscillation can be reduced by minimizing the vibration response, and the controllability and comfort of the vehicle and the adaptability of the target suspension parameters and the working condition of the deceleration strip are improved.

Description

Technical Field

[0001] The present application relates to the field of vehicle noise, vibration, harshness (NVH) and dynamics control, and specifically to a suspension parameter determination method and device, a parameter adjustment method and device, and equipment. Background Art

[0002] In related art, suspension parameter design typically determines the damping ratio based on a fixed sprung frequency offset. This resulting suspension parameter lacks theoretical support and struggles to strike a balance between comfort and handling. When a vehicle passes over a speed bump, improperly set sprung frequency offset in the rear suspension can cause severe vibration in the rear seats. In severe cases, this can lead to violent oscillations and significant bouncing, impacting the user's driving experience. Summary of the Invention

[0003] The embodiments of the present application provide a suspension parameter determination method and device, a parameter adjustment method and device, and an apparatus, which can better suppress the violent oscillation and large jump of the vehicle when passing over a speed bump, thereby further improving the user's driving experience.

[0004] In order to achieve the above objectives, the technical solutions adopted in this application are as follows: A method for determining suspension parameters, comprising: Obtain the displacement time response of the vehicle body in a target direction under a speed bump condition. The speed bump condition represents a vehicle traveling over a target speed bump, with the target direction perpendicular to the ground. The displacement time response is determined based on the displacement excitation and velocity excitation of the vehicle wheels by the target speed bump, as well as a dynamic model of the vehicle's suspension system. The displacement excitation and velocity excitation are determined based on the dimensional parameters of the target speed bump. A set of target suspension parameters for the suspension system is determined with the goal of minimizing a first target parameter. The first target parameter is determined based on the displacement-time response and suspension parameters of the suspension system. The first target parameter at least characterizes the vibration response of the vehicle in a target direction under a speed bump condition. The target suspension parameters include a target sprung frequency deviation and a target damping ratio.

[0005] According to the above technical approach, by obtaining the displacement time response of the vehicle body in a target direction under a speed bump condition, and constructing first target parameters based on the displacement time response and suspension parameters, a set of optimal suspension parameters is determined with the goal of minimizing the first target parameters. Thus, by optimizing the first target parameters by considering the displacement time response of the vehicle body in the target direction under the speed bump condition, a corresponding set of target sprung deflection frequencies and target damping ratios can be obtained as target suspension parameters. Furthermore, by minimizing the vehicle vibration response under the speed bump condition based on the target suspension parameters, the vehicle's suspension system can improve the effectiveness of suppressing vehicle vibration under the speed bump condition, reduce the likelihood of violent oscillations and significant jumps, and thus improve vehicle controllability and comfort. Furthermore, by determining the displacement time response of the vehicle body in the target direction based on the displacement and velocity excitations of the vehicle tires and incorporating a dynamic model of the suspension system, the accuracy of the displacement time response of the vehicle body in the target direction can be further improved, thereby improving the accuracy of the target suspension parameters determined based on the displacement time response and the adaptability of the target suspension parameters to the speed bump condition corresponding to the target speed bump.

[0006] In some embodiments, the time response of the displacement of the vehicle body in the target direction includes a first displacement of a front seat rail of the vehicle in the target direction and a second displacement of a rear seat rail of the vehicle in the target direction, and the first target parameter is determined based on the peak and valley values ​​of the first displacement and the peak and valley values ​​of the second displacement, or is determined based on the peak and valley values ​​of the first displacement, the peak and valley values ​​of the second displacement, and the height of the upper limit position of the suspension system.

[0007] Based on the above technical means, in the embodiments of the present application, a first target parameter is constructed by combining the displacement of the front and rear seat rails in the target direction, or by combining the displacement of the front and rear seat rails in the target direction and the upper limit position of the suspension system. This not only improves the accuracy of the description of the vehicle body's dynamic response characteristics based on multi-dimensional vibration response-related parameters, but also provides more reliable data support for subsequent suspension parameter optimization.

[0008] In some embodiments, the suspension parameters include sprung deflection frequency and damping ratio; and determining a set of target suspension parameters of the suspension system with the goal of minimizing the first target parameter includes: Obtaining multiple sets of sprung deflection frequencies and damping ratios that satisfy the first constraint condition; For each set of sprung frequency deviation and damping ratio, determining a first target parameter corresponding to the current set of sprung frequency deviation and damping ratio; Determine the smallest first target parameter among the groups of sprung frequency deviations and damping ratios as the target sprung frequency deviations and target damping ratios; The target suspension parameters are determined based on the target sprung deflection frequency and the target damping ratio.

[0009] According to the above technical approach, multiple sets of sprung frequency deflections and damping ratios that satisfy the first constraint are obtained. For each set of sprung frequency deflections and damping ratios, corresponding first target parameters are calculated. The set that minimizes the first target parameters is then selected as the target sprung frequency deflection and target damping ratio. This allows the vibration response of the vehicle when passing over a speed bump to be controlled based on different combinations of sprung frequency deflections and damping ratios. Target suspension parameters are then determined based on the set of target sprung frequency deflections and damping ratios that minimize the first target parameters and better meet the desired performance. This improves vibration suppression when the vehicle passes over a speed bump, increases the likelihood of suppressing violent oscillations and significant bouncing, and ultimately enhances the user experience.

[0010] In some embodiments, determining a first target parameter corresponding to a current set of sprung deflection frequency and damping ratio includes: Based on a current set of sprung deflection frequencies and damping ratios, determine first, second, third, fourth, and fifth sub-target parameters under a speed bump operating condition; the first sub-target parameter includes a first peak value of the first displacement, the second sub-target parameter includes an absolute value of a difference between a second valley value of the first displacement after the second peak and a third peak value, the third sub-target parameter includes the first peak value of the second displacement, the fourth sub-target parameter includes an absolute value of a difference between a second valley value of the second displacement after the second peak and the third peak value, and the fifth sub-target parameter includes a maximum absolute value of a difference between a height of an upper limit position of a front suspension and a height of an upper limit position of a rear suspension of the suspension system; The first sub-target parameter, the second sub-target parameter, the third sub-target parameter, the fourth sub-target parameter, and the fifth sub-target parameter are summed to obtain a first target parameter corresponding to a current set of sprung frequency deviation and damping ratio.

[0011] According to the above technical approach, by summing multiple sub-target parameters to obtain the first target parameters corresponding to each set of sprung deflection frequencies and damping ratios, this allows for a more comprehensive assessment of the impact of suspension parameters on the vehicle's dynamic vibration performance under speed bump conditions, enabling faster and more accurate determination of the first target parameters for each set of sprung deflection frequencies and damping ratios. Furthermore, by minimizing the sum of the first, second, third, fourth, and fifth sub-target parameters, a set of target suspension parameters is found that effectively suppresses vehicle body vibration without sacrificing ride comfort.

[0012] In some embodiments, the first constraint includes at least one of the following: The sprung frequency deviation is greater than a first sprung frequency deviation threshold and less than a second sprung frequency deviation threshold; the sprung frequency deviation includes the sprung frequency deviation of the front suspension and the sprung frequency deviation of the rear suspension; The damping ratio is greater than a first damping ratio threshold and less than a second damping ratio threshold; the damping ratio includes a damping ratio of a front suspension and a damping ratio of a rear suspension; The sprung frequency deviation of the front suspension is greater than that of the rear suspension; The sprung frequency deviation of the front suspension is greater than the product of the sprung frequency deviation of the rear suspension and the first coefficient, and less than the product of the sprung frequency deviation of the rear suspension and the second coefficient; the second coefficient is greater than the first coefficient, and both the first coefficient and the second coefficient are greater than 1; The vehicle's pitch angle frequency is less than the rotation angle frequency in the target direction; The second peak value of the second displacement is less than the product of the first peak value and the third coefficient; the third coefficient is greater than 0 and less than 1.

[0013] By setting at least one first constraint condition, the aforementioned technical approach can further enhance the effectiveness of the target suspension parameters, determined based on the first constraint condition, in suppressing vehicle vibrations under speed bump conditions. By comprehensively considering the sprung deflection frequency, damping ratio, and pitch angle frequency, the overall controllability and comfort of the vehicle over speed bumps can be further balanced, providing users with a smoother and more comfortable driving experience.

[0014] In some embodiments, the suspension system includes a vibration reduction assembly, and the suspension parameter determination method further includes: Acquire multiple sets of second damping forces corresponding to at least two target relative velocities that satisfy the second constraint condition; the target relative velocity is the relative velocity between the two ends of the vibration reduction assembly; For each set of second damping forces corresponding to the at least two target relative velocities, determining a second target parameter corresponding to the current set of second damping forces; the second target parameter is determined based on the first damping force and the second damping force, the first damping force is determined based on a first damping coefficient corresponding to the target damping ratio, and the first damping coefficient does not change with the relative velocity between the two ends of the vibration reduction assembly; The one with the smallest second target parameter corresponding to each group of second damping forces is determined as the target damping force corresponding to the vibration reduction assembly and at least two target relative speeds respectively; when the relative speed at both ends of the vibration reduction assembly is less than 0, the value of the target damping force corresponding to the relative speed is less than the value of the corresponding first damping force; when the relative speed at both ends of the vibration reduction assembly is greater than 0, the value of the target damping force corresponding to the relative speed is greater than the value of the corresponding first damping force.

[0015] The above technical approach introduces multiple second damping force combinations that satisfy the second constraint and optimizes them based on the second target parameter to determine the optimal target damping force. This reduces the damping force during the compression phase of the damping assembly to reduce the sense of lift when the vehicle passes over speed bumps, improving ride comfort. It also increases the damping force during the extension phase of the damping assembly to accelerate energy dissipation and vibration attenuation, thereby achieving a balance between comfort and handling when the vehicle is operating over speed bumps. This effectively suppresses the vehicle's body vibration response when passing over speed bumps, improving the user experience.

[0016] In some embodiments, determining a second target parameter corresponding to a current set of the second damping forces includes: determining a first region based on the target relative speed interval and a first trajectory of the first damping force changing with the at least two target relative speeds; determining a second region based on the target relative speed interval and a current set of second trajectories of the second damping force changing with the at least two target relative speeds; The absolute value of the difference between the first area of ​​the first region and the second area of ​​the second region is determined as the second target parameter corresponding to the current set of the second damping force; the first area represents the first vibration attenuation power corresponding to the first damping force within the target relative speed range, and the second area represents the second vibration attenuation power corresponding to the second damping force within the target relative speed range.

[0017] According to the above technical approach, a first region and a second region are constructed based on the target relative speed range and the damping force variation trajectory, and the absolute value of the area difference between the first and second regions is calculated as the second target parameter. This allows the damping force to vary nonlinearly with the relative speed at both ends of the damping assembly, achieving a balance between comfort and handling for the vehicle under speed bump conditions. This ensures that the vibration attenuation power before and after the equivalent damping (from linear to nonlinear) is equal or approximately equal. In other words, the movement of the front and rear suspensions can still be stopped approximately simultaneously, further improving the control of the vehicle's vibration response under speed bump conditions.

[0018] In some embodiments, the second constraint includes: The slope of a line connecting corresponding points of each two adjacent target relative speeds on the second trajectory of at least two target relative speeds satisfies a target slope condition; the target slope condition indicates that when the target relative speed is less than 0, the value of the second damping force corresponding to the target relative speed is less than the value of the corresponding first damping force; when the target relative speed is greater than 0, the value of the second damping force corresponding to the target relative speed is greater than the value of the corresponding first damping force.

[0019] The above technical approach sets a target slope condition and adjusts the magnitude relationship between the second damping force and the first damping force based on the positive or negative target relative velocity (i.e., the extension and contraction phase of the damping assembly). This reduces the sense of lift during the damping assembly's compression phase, improving ride comfort. During the damping assembly's extension phase, it increases energy dissipation, rapidly damping body vibrations and thus improving vehicle vibration control. At the same time, it allows the front and rear suspension movements to be stopped nearly simultaneously.

[0020] A parameter adjustment method, comprising: In response to the presence of a target speed bump within a target distance along a driving direction of the vehicle, a displacement time response of the vehicle body in the target direction under a speed bump operating condition is obtained; the speed bump operating condition represents the vehicle traveling over the target speed bump, with the target direction being perpendicular to the ground, and the displacement time response is determined based on a displacement excitation and a velocity excitation of the vehicle wheels by the target speed bump, and a dynamic model of the vehicle's suspension system, wherein the displacement excitation and the velocity excitation are determined based on dimensional parameters of the target speed bump; Determining a set of target suspension parameters for the suspension system with the goal of minimizing a first target parameter; the first target parameter is determined based on the displacement-time response and suspension parameters of the suspension system, and the first target parameter at least represents the vibration response of the vehicle in a target direction under a speed bump condition; the target suspension parameters include a target sprung frequency deviation and a target damping ratio; Adjust the current suspension parameters of the suspension system to target suspension parameters.

[0021] A suspension parameter determination device, comprising: a first acquisition unit configured to acquire a displacement time response of a vehicle body in a target direction under a speed bump operating condition; the speed bump operating condition characterizing a vehicle traveling over a target speed bump, wherein the target direction is perpendicular to the ground, and wherein the displacement time response is determined based on a displacement excitation and a velocity excitation of the vehicle wheels by the target speed bump, and a dynamic model of the vehicle's suspension system, wherein the displacement excitation and the velocity excitation are determined based on dimensional parameters of the target speed bump; The first determination unit is configured to determine a set of target suspension parameters of the suspension system with the goal of minimizing a first target parameter; the first target parameter is determined based on a displacement-time response of a vehicle body in a target direction under a speed bump condition and suspension parameters of the suspension system; the first target parameter at least characterizes a vibration response of the vehicle in the target direction under the speed bump condition; the target suspension parameters include a target sprung frequency deviation and a target damping ratio.

[0022] A parameter adjustment device, comprising: a second acquisition unit configured to, in response to the presence of a target speed bump within a target distance along a driving direction of the vehicle, acquire a displacement time response of a vehicle body in a target direction under a speed bump operating condition; the speed bump operating condition characterizing the vehicle traveling over the target speed bump, with the target direction perpendicular to the ground, and the displacement time response being determined based on a displacement excitation and a velocity excitation of the vehicle wheels by the target speed bump, and a dynamic model of a suspension system of the vehicle, wherein the displacement excitation and the velocity excitation are determined based on dimensional parameters of the target speed bump; a second determination unit configured to determine a set of target suspension parameters of the suspension system with the goal of minimizing a first target parameter; the first target parameter being determined based on a displacement-time response and suspension parameters of the suspension system, the first target parameter representing at least a vibration response of the vehicle in a target direction under a speed bump condition, the target suspension parameters including a target sprung frequency deviation and a target damping ratio; The adjustment unit is used to adjust current suspension parameters of the suspension system to target suspension parameters.

[0023] An electronic device includes a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and the processor implements the above method when executing the program.

[0024] A computer-readable storage medium stores a computer program, which can be executed by a processor to implement the above method.

[0025] A computer program product includes a computer program or instructions, which implements some or all of the steps in the above method when executed by a processor.

[0026] Beneficial effects of this application: (1) By considering the displacement time response of the vehicle body in the target direction under the speed bump condition and optimizing the first target parameter, a set of corresponding target spring deflection frequency and target damping ratio can be obtained as target suspension parameters; further, by utilizing the vehicle suspension system based on the set of target suspension parameters, the vibration response of the vehicle under the speed bump condition can be minimized, thereby improving the effect of suppressing vehicle vibration under the speed bump condition, reducing the possibility of violent oscillation and large jump of the vehicle, and improving the controllability and comfort of the vehicle; in addition, by determining the displacement time response of the vehicle body in the target direction based on the displacement excitation and velocity excitation of the vehicle tire and combining the dynamic model of the suspension system, the accuracy of the displacement time response of the vehicle body in the target direction can be further improved, thereby improving the accuracy of the target suspension parameters determined based on the displacement time response and the adaptability of the target suspension parameters to the speed bump condition corresponding to the target speed bump; (2) It can improve the accuracy of describing the dynamic response characteristics of the vehicle body based on multi-dimensional vibration response related parameters, and can also provide more reliable data support for subsequent suspension parameter optimization; (3) It can improve the accuracy of describing the dynamic response characteristics of the vehicle body based on multi-dimensional vibration response related parameters, and can also provide more reliable data support for subsequent suspension parameter optimization; (4) The vibration response of the vehicle when passing over a speed bump can be controlled based on different combinations of sprung deflections and damping ratios. Target suspension parameters can be determined based on a set of target sprung deflections and target damping ratios that minimize the first target parameter and better meet the expected effect. This improves the suppression of vibration when the vehicle passes over a speed bump, increases the possibility of suppressing violent oscillations and large jumps, and thus improves the user's driving experience. (5) On the one hand, the influence of suspension parameters on the dynamic performance of the vehicle in terms of vibration under speed bump conditions can be more comprehensively evaluated, so that the first target parameters corresponding to each set of sprung deflection frequency and damping ratio can be obtained more quickly and accurately. On the other hand, by minimizing the sum of the first sub-target parameter, the second sub-target parameter, the third sub-target parameter, the fourth sub-target parameter, and the fifth sub-target parameter, a set of target suspension parameters that can better suppress vehicle body vibration without sacrificing much ride comfort can be found. (6) By setting at least one first constraint condition, the target suspension parameters determined based on the first constraint condition can be further improved in suppressing the vibration of the vehicle under speed bump conditions. By comprehensively considering the sprung deflection frequency, damping ratio, and pitch angle frequency, the overall controllability and comfort of the vehicle when passing over speed bumps can be further balanced, providing users with a smoother and more comfortable driving experience. (7) It can reduce the damping force in the compression stage of the shock absorber component to reduce the lifting feeling when the vehicle passes through the speed bump, improve the ride comfort, and increase the damping force in the extension stage of the shock absorber component to accelerate energy dissipation and vibration attenuation, thereby achieving a balance between the comfort and controllability of the vehicle under the speed bump working condition, further effectively suppressing the body vibration response generated by the vehicle when passing through the speed bump, and improving the user's driving experience; (8) It is possible to make the vibration attenuation power before and after the damping (from linear to nonlinear) equivalent equal or approximately equal, based on the nonlinear variation of the damping force with the relative speed at both ends of the shock absorbing assembly, and to achieve a balance between the comfort and handling of the vehicle under speed bump conditions. That is, the movement of the front and rear suspensions can still be stopped approximately at the same time, further improving the vibration response control effect of the vehicle under speed bump conditions; (9) It can reduce the lifting feeling during the compression stage of the shock absorber component and improve the ride comfort; it can improve the energy dissipation capacity during the extension stage of the shock absorber component, quickly attenuate the body vibration, and thus improve the controllability of the vehicle vibration reduction. At the same time, the movement of the front and rear suspensions can still be stopped at approximately the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1A schematic diagram of the implementation process of a suspension parameter determination method provided in an embodiment of the present application Figure 1 ; Figure 2 A schematic diagram of a dynamic model of a suspension system provided in an embodiment of the present application; Figure 3 A schematic diagram of a speed bump provided in an embodiment of the present application; Figure 4 A schematic diagram of vehicle body movement when a front suspension is impacted provided in an embodiment of the present application; Figure 5 A schematic diagram of the movement of a vehicle body when a rear suspension is impacted provided in an embodiment of the present application; Figure 6 A schematic diagram of the relationship between the damping force and the relative speed corresponding to a key speed point provided in an embodiment of the present application; Figure 7 A schematic diagram of the structure of a suspension parameter determination device provided in an embodiment of the present application; Figure 8 A schematic diagram of the free vibration response of a single-degree-of-freedom system under different sprung frequency deviations provided by an embodiment of the present application; Figure 9 A schematic diagram of the implementation process of a suspension parameter determination method provided in an embodiment of the present application Figure 2 ; Figure 10 A schematic diagram of the displacement of the front seat rail under a speed bump condition provided by an embodiment of the present application; Figure 11 A schematic diagram of the displacement of the rear seat rail under a speed bump condition provided by an embodiment of the present application; Figure 12 A schematic diagram of the displacement of the vehicle body pitch angle under a speed bump working condition provided in an embodiment of the present application; Figure 13 A schematic diagram comparing the linear damping and the optimized nonlinear damping of a shock absorber provided in an embodiment of the present application; Figure 14 A schematic diagram of an implementation flow of a parameter adjustment method provided in an embodiment of the present application; Figure 15 A schematic diagram of the structure of a parameter adjustment device provided in an embodiment of the present application; Figure 16 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] The following will describe the embodiments of the present application with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand the other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for the purpose of illustrating the present application and are not intended to limit the scope of protection of the present application.

[0029] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. Therefore, the illustrations only show components related to the present application and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0030] The sprung deflection frequency and damping ratio of a suspension are important parameters of the suspension system. The sprung deflection frequency represents the free vibration frequency of the sprung portion after an impact and is one of the parameters used to measure the suspension system's ability to control vehicle body vibration. The damping ratio describes the rate of decay of the suspension system's free vibration and the rate at which energy is dissipated during free vibration. A higher damping ratio results in faster vibration decay, but an excessively high damping ratio may affect ride comfort. The sprung deflection frequency is primarily determined by the suspension's Z-direction (perpendicular to the ground) stiffness (hereinafter referred to as suspension stiffness), the sprung mass, and the sprung mass distribution coefficient, which describes the distribution of the sprung mass between the front and rear axles. Given the sprung mass allocated to the front and rear suspensions, the sprung deflection frequencies of the front and rear suspensions are determined by their respective stiffnesses, while the damping ratio is determined by the sprung deflection frequency and the damping coefficient of the shock absorber.

[0031] In the prior art, the design of front and rear suspension sprung frequency deviations generally adopts a design concept of low front suspension sprung frequency deviation and high rear suspension sprung frequency deviation. This design concept can lead to insufficient isolation of the rear suspension from unsprung Z-direction impacts, resulting in significant impact on the rear seats when the vehicle passes over speed bumps, causing severe oscillations and large bouncing, leading to a poor user experience. The theoretical basis for this "low front, high rear" frequency deviation design is that the greater the rear suspension sprung frequency deviation, the shorter the free vibration period of the sprung portion of the rear suspension, resulting in faster decay. This allows the rear suspension's free vibration decay process to match that of the front suspension when the vehicle passes over a speed bump, thereby simultaneously stopping vibrations in both front and rear suspensions. However, the decay time of the rear suspension's free vibration is actually determined by a combination of initial displacement, vehicle speed, wheelbase, damping ratio, and sprung frequency deviation. Therefore, estimating the free vibration decay time based solely on the sprung frequency deviation is inaccurate.

[0032] Furthermore, the design of the front and rear suspension damping ratios typically involves using simulation software to determine a fixed set of front and rear spring offset frequencies, repeatedly varying the damping coefficients of the front and rear suspension shock absorbers, and then conducting multiple trials to determine the optimal damping ratio. For example, this is determined by dividing the damping coefficient by the critical damping coefficient. This approach lacks theoretical support and is inefficient, hindering the development progress of related projects.

[0033] On this basis, the embodiment of the present application proposes a suspension parameter determination method, which can be executed by an electronic device. The electronic device may refer to a server, a laptop, a tablet computer, a desktop computer, a smart TV, a set-top box, a mobile device (such as a mobile phone, a portable video player, a personal digital assistant, a dedicated messaging device, a portable gaming device), or other device with data processing capabilities. Figure 1 As shown, the suspension parameter determination method includes the following steps S11 to S12: Step S11: Obtain the displacement time response of the vehicle body in the target direction under the speed bump working condition; the speed bump working condition indicates that the vehicle travels through the target speed bump, and the target direction is perpendicular to the ground.

[0034] Here, the speed bump condition refers to the process of a vehicle passing over a speed bump at a certain speed. Under speed bump conditions, the front and rear wheels of the vehicle are sequentially excited by the road surface, resulting in complex vibration responses of the vehicle body. These include, but are not limited to, displacement changes in the seat rails, height changes at the upper extremes of the suspension system, and changes in the vehicle body pitch angle.

[0035] The target direction is perpendicular to the ground, which is the vibration direction mainly controlled by the suspension system. Under speed bump conditions, the vibration of the vehicle body in this direction is more obvious.

[0036] The displacement time response is the dynamic response of the vehicle body's vertical displacement over time. It reflects the dynamic response characteristics of the suspension system to road excitation and is used to optimize suspension parameters.

[0037] In some embodiments, the displacement time response may include a curve showing the vertical displacement of the vehicle body (eg, center of mass, seat rails, etc.) changing with time under a speed bump condition.

[0038] In some embodiments, the displacement time response may be determined based on the displacement excitation and velocity excitation of the vehicle's wheels by the target speed bump and a dynamic model of the vehicle's suspension system. The displacement excitation and velocity excitation may be determined based on size parameters of the target speed bump.

[0039] For example, a dynamic model can be established to simulate the vibration process of a vehicle under speed bump conditions. Further, by combining the displacement excitation and velocity excitation of the vehicle's wheels by the target speed bump, the corresponding dynamic equations can be solved to at least obtain the displacement time response of the vehicle body in the target direction under the speed bump condition.

[0040] In some embodiments, the vibration response of the suspension system may include a vibration response in a target direction and a vibration response in a pitch direction, and the first target parameter may characterize the vibration response of the vehicle in the target direction and the vibration response of the vehicle body in the pitch direction under speed bump conditions.

[0041] For example, Figure 2 As shown, a four-degree-of-freedom dynamic model of the left 1 / 2 vehicle suspension system under road excitation can be built in the simulation software; wherein the four degrees of freedom can include the degrees of freedom corresponding to the front wheel vertical direction (target direction), the rear wheel vertical direction (target direction), the vehicle body vertical direction (target direction), and the vehicle body pitch direction.

[0042] Combine Figure 2 , the vibration equation of this model can be found in formula (1): (1); exist Figure 2 And in formula (1), represents the unsprung mass of the front suspension, represents the unsprung mass of the rear suspension, represents the sprung mass (corresponding to the body and powertrain), represents the sprung mass passing around its center of mass The pitch moment of inertia of the axis (corresponding to the vehicle coordinate system); and Represent the stiffness and damping coefficient of the front tire respectively, and Respectively represent the stiffness and damping coefficient of the rear tire, and Respectively represent the stiffness and damping coefficient of the front suspension, and Indicates the stiffness and damping coefficient of the rear suspension; express The corresponding displacement, express The corresponding displacement, represents the displacement of the upper end of the front suspension, represents the displacement of the upper end of the rear suspension, express The displacement at the center of mass, represents the displacement at the front seat rail, Indicates the displacement at the rear seat rail; In direction, The distance between the center of mass and the upper end of the front suspension is , the distance between it and the upper end of the rear suspension is , the distance between the front seat rail and the upper end of the front suspension is , the distance between the rear seat rail and the upper end of the rear suspension is , express The rotational angular displacement; and are the road displacement excitations on the front and rear wheels, and are the road speed excitations to the front and rear wheels, 、 、 as well as Respectively 、 、 as well as The corresponding acceleration. and It can be corresponded to the displacement time response of the vehicle body.

[0043] For example, obtaining and The process can be seen in formula (2): (2).

[0044] The sprung frequency offset of the front suspension is determined based on the stiffness and sprung mass of the front suspension, and the sprung frequency offset of the rear suspension is determined based on the stiffness and sprung mass of the rear suspension. When the sprung frequency offset and damping ratio of the front and rear suspensions are respectively determined, the stiffness and damping coefficients of the front and rear suspensions are respectively unknown. By including and The formula is expressed as follows: By including and The formula is expressed as follows, that is, the displacement time response of the vehicle body and It changes with the stiffness and damping coefficient of the front and rear suspension.

[0045] Step S12: Determine a set of target suspension parameters for the vehicle's suspension system with the goal of minimizing a first target parameter; the first target parameter is determined based on the displacement-time response and suspension parameters of the suspension system, and the first target parameter at least represents the vibration response of the vehicle in a target direction under a speed bump condition. The target suspension parameters include a target sprung frequency deviation and a target damping ratio.

[0046] The first target parameter is a comprehensive evaluation indicator constructed based on the vehicle's body displacement time response and suspension parameters under speed bump conditions. It quantifies the vehicle's vibration intensity and attenuation characteristics under speed bump conditions. A smaller first target parameter indicates better vibration control. Therefore, minimizing the first target parameter optimizes the vehicle's vibration response in the target direction under speed bump conditions. When the first target parameter is minimized, the corresponding suspension parameters (sprung frequency deviation and damping ratio) are the target suspension parameters.

[0047] In this embodiment of the present application, a set of optimal suspension parameters is determined by obtaining the displacement time response of the vehicle body in a target direction under speed bump conditions, constructing first target parameters based on the displacement time response and suspension parameters, and minimizing the first target parameters. By optimizing the first target parameters by considering the displacement time response of the vehicle body in the target direction under speed bump conditions, a corresponding set of target sprung deflection frequencies and target damping ratios can be obtained as target suspension parameters. Furthermore, based on this set of target suspension parameters, the vehicle's suspension system can minimize the vibration response under speed bump conditions, thereby improving the effectiveness of suppressing vehicle vibration under speed bump conditions and reducing the likelihood of violent oscillations and significant jumps, thereby enhancing vehicle controllability and comfort.

[0048] In some embodiments, the above step S11 may include the following steps S111 to S112: Step S111: Determine the displacement excitation and speed excitation of the target speed bump on the wheels of the vehicle based on a first function representing the size parameters of the target speed bump.

[0049] Here, for the speed bump condition where a vehicle passes over a speed bump, a function can be used to simulate the speed bump's shape. For example, a downward-opening quadratic function or a sine wave function can be used to simulate the speed bump's shape. Using the first function, the contact process between the vehicle's tires and the road surface can be more accurately simulated when the vehicle passes over the target speed bump.

[0050] In some embodiments, the form of the first function can be adjusted according to actual application requirements. For example, a quadratic function with a downward opening can better simulate common raised speed bumps, while a sinusoidal function is more suitable for simulating periodic undulating speed bumps.

[0051] The size parameters characterizing the target speed bump may include, but are not limited to, the width of the speed bump (the length of the speed bump cross section), the height of the speed bump, the slope of the speed bump, and / or the circumference of the speed bump cross section.

[0052] It can be understood that when a quadratic function opening downward is selected to fit the target speed bump shape, since the quadratic function opening downward has a continuous derivative, it is easier to calculate the displacement and speed change of the tire on the target speed bump.

[0053] For example, Figure 3 As shown, the speed bump size parameter is length ,high When the speed bump is the target speed bump, the vehicle speed is , taking the moment when the front wheel starts to go over the speed bump as the zero time, the current time can be expressed as , the shape of the speed bump is simulated by using a quadratic function with an opening downward. When the wheels of the vehicle come into contact with the speed bump, the displacement excitation of the front and rear wheels by the speed bump is and , and speed incentives and Please refer to formula (3): (3).

[0054] For example, when the wheels are not in contact with the speed bump, the displacement excitation and velocity excitation of the front and rear wheels by the road surface are both zero, see formula (4): (4).

[0055] Step S112: Based on the displacement excitation and velocity excitation of the vehicle wheels and the dynamic model of the suspension system, determine the displacement time response of the vehicle body in the target direction under the speed bump working condition corresponding to the target speed bump.

[0056] Here, by combining the displacement excitation of the vehicle wheels, the velocity excitation of the vehicle wheels, and the dynamic model of the suspension system, the accuracy of the displacement time response of the vehicle body when passing over the target speed bump can be improved.

[0057] For example, in the is the mass matrix, is the damping coefficient matrix, is the stiffness matrix, is the displacement time response column vector, When is the excitation force column vector, the above formula (1) can be expressed in matrix form, see formula (5): (5); in, 、 、 、 as well as Please refer to formula (6): (6).

[0058] Furthermore, construct the vector ,vector Represents the displacement time response (displacement changing with time) and velocity time response (velocity changing with time) corresponding to the four degrees of freedom, combined with formula (6) using vector By reducing the order of formula (5), we can get formula (7): (7); in, is a zero matrix with four rows and four columns, is the identity matrix with four rows and four columns.

[0059] Combining formula (3) and formula (4) to solve formula (7), we can get the vector The values ​​of each item in , that is, the displacement time response and velocity time response corresponding to each degree of freedom; further, combined with formula (2), the displacement time response of the front seat rail and the rear seat rail can be obtained, that is, and .

[0060] In this embodiment of the present application, the displacement and velocity excitations of the vehicle tires are determined based on a first function representing the target speed bump size parameters, and the vehicle body's displacement time response in the target direction is determined in conjunction with the suspension system's dynamic model. This further improves the accuracy of the vehicle body's displacement time response in the target direction, thereby improving the accuracy of the target suspension parameters determined based on the displacement time response and the adaptability of the target suspension parameters to the speed bump operating conditions corresponding to the target speed bump.

[0061] In some embodiments, the time response of the displacement of the vehicle body in the target direction includes a first displacement of the front seat rail of the vehicle in the target direction and a second displacement of the rear seat rail of the vehicle in the target direction, and the first target parameter is determined based on the peak and valley values ​​of the first displacement and the peak and valley values ​​of the second displacement, or is determined based on the peak and valley values ​​of the first displacement, the peak and valley values ​​of the second displacement, and the height of the upper limit position of the suspension system.

[0062] The front and rear seat rails, located at the front and rear of the vehicle body, respectively, support the passenger seats and allow them to move longitudinally. When the vehicle traverses complex road conditions such as speed bumps, their displacement directly reflects the vibration intensity and comfort experienced by occupants. By considering the displacement of the front and rear seat rails in the target direction, the dynamic response of the vehicle body to vibration can be more accurately captured, better capturing the differences in the riding experience between front and rear passengers.

[0063] The suspension's upper limit, or top dead center (TDC), typically determines the suspension's static height and upper limit of dynamic travel. The suspension's upper limit is determined based on pitch angular displacement. Under speed bump conditions, when the wheel contacts the bump, the suspension compresses, causing the TDC to move upward relative to the wheel center. This compression stroke depends on the bump's height and suspension stiffness. When the wheel reaches the bump's apex, the suspension compression reaches its maximum, and the TDC displacement reaches its maximum value, meaning the TDC reaches its maximum height. When the wheel leaves the bump, the suspension rebounds, causing the TDC to move downward to its original position. Insufficient damping at this point can result in multiple oscillations. Therefore, by considering the height of the suspension's upper limit, the dynamic response characteristics of the vehicle body to vibration in the pitch direction can be more accurately captured.

[0064] It is understandable that the first target parameter is determined by the peak and valley values ​​of the first displacement of the front seat rail, the peak and valley values ​​of the second displacement of the rear seat rail, and the height of the upper limit position of the suspension system. This multi-dimensional evaluation method can more comprehensively reflect the vibration amplitude, energy distribution and structural response of the vehicle body during the impact of passing over a speed bump.

[0065] In the embodiments of the present application, a first target parameter is constructed by combining the displacement of the front and rear seat rails in a target direction, or by combining the displacement of the front and rear seat rails in a target direction with the upper limit position of the suspension system. This not only improves the accuracy of the description of the vehicle body's dynamic response characteristics based on multi-dimensional vibration response-related parameters, but also provides more reliable data support for subsequent suspension parameter optimization.

[0066] In some embodiments, the suspension parameters include sprung deflection frequency and damping ratio, and the above step S12 may include the following steps S121 to S124: Step S121: Acquire multiple sets of sprung deflection frequencies and damping ratios that satisfy a first constraint condition.

[0067] Here, the first constraint may be a constraint for limiting the range of the sprung frequency deflection and the damping ratio. For example, the first constraint may include a constraint that directly limits the value of the sprung frequency deflection and / or the damping ratio, or may include a constraint that limits parameters associated with the sprung frequency deflection and / or the damping ratio, thereby indirectly limiting the sprung frequency deflection and / or the damping ratio.

[0068] In some embodiments, an optimization model can be used to determine suspension parameters with the goal of minimizing a first target parameter. The optimization model primarily includes three components: design variables, an objective function, and constraints, and is used to find the optimal solution to the objective function within the specified constraints.

[0069] For example, the first optimization model can be used to find a set of design variable values ​​that optimizes the first objective function and satisfies the first preset constraint. The design variables of the first optimization model are the sprung deflection frequencies of the front and rear suspensions, respectively. and (unit: Hz), and the damping ratios of the front and rear suspensions respectively and .

[0070] Step S122: For each set of sprung frequency deviation and damping ratio, determine a first target parameter corresponding to the current set of sprung frequency deviation and damping ratio.

[0071] Here, different groups correspond to different sprung deflections and damping ratios, and may also correspond to different first target parameters.

[0072] In some embodiments, the first target parameter may be a single-dimensional parameter or a fused parameter determined by combining vibration characteristics from multiple dimensions. For example, the first target parameter may be determined solely based on the displacement time response of the vehicle seat rail, or may be determined by combining the displacement time response of the vehicle seat rail and the height of the suspension top dead center.

[0073] For example, the first target parameter corresponding to the sprung deflection frequency and the damping ratio may correspond to the first target function of the first optimization model in step S121 .

[0074] Step S123: Determine the smallest first target parameter among the groups of sprung frequency deviations and damping ratios as the target sprung frequency deviations and target damping ratios.

[0075] It can be understood that by comparing the vibration response performance of various combinations of sprung frequency deflections and damping ratios, the combination that minimizes the first target parameter among those that satisfy the first constraint is the optimal combination for achieving a better balance between comfort and handling in the vehicle's vibration response under speed bump conditions. For example, the combination of sprung frequency deflection and damping ratio that reduces rear seat vibration amplitude while effectively controlling vehicle body pitch vibration is the target sprung frequency deflection and target damping ratio.

[0076] Illustratively, the target sprung deflection frequency and the target damping ratio are the optimal solutions of the objective function of the first optimization model in step S121 .

[0077] Step S124: Determine target suspension parameters based on the target sprung deflection frequency and the target damping ratio.

[0078] Here, the current target sprung frequency deviation and target damping ratio may be used as target suspension parameters, or the final target suspension parameters may be obtained by further optimization based on the current target sprung frequency deviation and target damping ratio.

[0079] For example, the currently obtained target damping ratio may be further optimized, such as by determining a set of dynamically adjustable target damping ratio values ​​based on a fixed target damping ratio value, thereby obtaining an optimized target damping ratio.

[0080] In this embodiment, multiple sets of sprung frequency deflections and damping ratios that satisfy a first constraint are obtained. For each set of sprung frequency deflections and damping ratios, corresponding first target parameters are calculated. The set that minimizes the first target parameters is then selected as the target sprung frequency deflection and target damping ratio. This allows the vibration response of the vehicle when passing over a speed bump to be controlled based on different combinations of sprung frequency deflections and damping ratios. Target suspension parameters are then determined based on the set of target sprung frequency deflections and damping ratios that minimize the first target parameters and better meet the desired performance. This improves vibration suppression when the vehicle passes over a speed bump, reduces the likelihood of violent oscillations and significant bouncing, and ultimately enhances the user's driving experience.

[0081] In some embodiments, determining the first target parameter corresponding to the current set of sprung deflection frequency and damping ratio in step S122 may include the following steps S1221 to S1222: Step S1221: Based on a current set of sprung deflection frequencies and damping ratios, determine a first sub-target parameter, a second sub-target parameter, a third sub-target parameter, a fourth sub-target parameter, and a fifth sub-target parameter under a speed bump operating condition; the first sub-target parameter includes a first peak value of the first displacement, the second sub-target parameter includes an absolute value of a difference between a second valley value of the first displacement after the second peak and a third peak value, the third sub-target parameter includes the first peak value of the second displacement, the fourth sub-target parameter includes an absolute value of a difference between a second valley value of the second displacement after the second peak and the third peak value, and the fifth sub-target parameter includes a maximum absolute value of a difference between a height of an upper limit position of a front suspension and a height of an upper limit position of a rear suspension of the suspension system.

[0082] Here, the first sub-target parameter corresponds to the first peak value of the displacement of the front seat rail, which can characterize the vibration response of the front seat rail when the front wheel of the vehicle starts to pass through the speed bump; the second sub-target parameter corresponds to the first peak value of the displacement of the rear seat rail, which can characterize the vibration response of the rear seat rail when the rear wheel of the vehicle starts to pass through the speed bump; the third sub-target parameter corresponds to the absolute value of the height difference between the second valley and the third peak of the front seat rail, which can characterize the attenuation of the vibration at the front seat; the fourth sub-target parameter corresponds to the absolute value of the height difference between the second valley and the third peak of the rear seat rail, which can characterize the attenuation of the vibration at the rear seat; the fifth sub-target parameter corresponds to the maximum value of the absolute value of the height difference between the upper limit position of the front suspension and the upper limit position of the rear suspension (the top dead center of the front and rear suspension), which can characterize the vibration response of the vehicle body in the pitch direction when passing through the speed bump.

[0083] Step S1222: Sum the first sub-target parameter, the second sub-target parameter, the third sub-target parameter, the fourth sub-target parameter, and the fifth sub-target parameter to obtain a first target parameter corresponding to the current set of sprung frequency deviation and damping ratio.

[0084] It can be understood that the first target parameter obtained by combining the five sub-target parameters can comprehensively evaluate the vibration response corresponding to the suspension parameters from multiple dimensions with higher accuracy.

[0085] For example, for the first optimization model in step S121, the corresponding objective function can be to minimize the value of the superposition of the five sub-objective parameters. Each sub-goal parameter can be corresponded to the value of a function; wherein, the function corresponding to the first sub-goal parameter is used to represent the first peak displacement of the front seat guide rail of the vehicle under the speed bump condition (which can be expressed as ), the function corresponding to the second sub-goal parameter is used to represent the first peak displacement of the rear seat rail (which can be expressed as ), the function corresponding to the third sub-goal parameter is used to represent the absolute value of the height difference between the second valley value (the valley value after the second peak value) and the third peak value (the peak value after the second valley value) of the front seat rail displacement (which can be expressed as ), the function corresponding to the fourth sub-goal parameter is used to represent the absolute value of the height difference between the second valley value (the valley value after the second peak value) and the third peak value (the peak value after the second valley value) of the rear seat rail displacement (which can be expressed as ), the function corresponding to the fifth sub-goal parameter is used to express the maximum absolute value of the difference between the heights corresponding to the front suspension top dead center and the rear suspension top dead center (i.e., the upper limit position of the front suspension and the upper limit position of the rear suspension) (which can be expressed as ).

[0086] It is understandable that, as the oscillatory motion is constantly decaying, The smaller it is, the smaller the maximum displacement of the front seat rail when the vehicle's front wheels pass over a speed bump, and the better the user experience; The smaller it is, the smaller the maximum displacement of the rear seat rail when the front wheels of the vehicle pass over the speed bump, and the better the user experience; The smaller it is, the smaller the change in the displacement of the front seat rail is, and the better the user experience is; The smaller it is, the smaller the change in the displacement of the rear seat rail is, and the better the user experience is; It can be determined based on the pitch angle displacement, The smaller it is, the smaller the angular movement in the pitch direction is, and the better the user experience is. 、 、 、 as well as The smaller the maximum value of the sum, the better the user experience.

[0087] For example, the method for determining the first optimization model can refer to formula (8): (8); in, This corresponds to the constraint condition of the first optimization model, that is, the first constraint condition.

[0088] In the embodiment of the present application, by summing multiple sub-target parameters to obtain the first target parameters corresponding to each set of sprung deflection frequencies and damping ratios, on the one hand, the impact of suspension parameters on the vehicle's dynamic vibration performance under speed bump conditions can be more comprehensively evaluated, thereby enabling the first target parameters corresponding to each set of sprung deflection frequencies and damping ratios to be obtained more quickly and accurately. On the other hand, by minimizing the sum of the first, second, third, fourth, and fifth sub-target parameters, a set of target suspension parameters that can better suppress vehicle body vibration without sacrificing ride comfort can be found.

[0089] In some embodiments, the first constraint includes at least one of the following: The sprung frequency deviation is greater than a first sprung frequency deviation threshold and less than a second sprung frequency deviation threshold; the sprung frequency deviation includes the sprung frequency deviation of the front suspension and the sprung frequency deviation of the rear suspension; The damping ratio is greater than a first damping ratio threshold and less than a second damping ratio threshold; the damping ratio includes a damping ratio of a front suspension and a damping ratio of a rear suspension; The sprung frequency deviation of the front suspension is greater than that of the rear suspension; The sprung frequency deviation of the front suspension is greater than the product of the sprung frequency deviation of the rear suspension and the first coefficient, and less than the product of the sprung frequency deviation of the rear suspension and the second coefficient; the second coefficient is greater than the first coefficient, and both the first coefficient and the second coefficient are greater than 1; The vehicle's pitch angle frequency is less than the rotation angle frequency in the target direction; The second peak value of the second displacement is less than the product of the first peak value and the third coefficient; the third coefficient is greater than 0 and less than 1.

[0090] Here, the first and second spring frequency deviation thresholds correspond to the lower and upper limits of the spring frequency deviation, respectively. Considering that excessive spring frequency deviation can lead to excessive suspension stiffness, poor vibration isolation, and a strong sense of lift, resulting in a poor user experience; while excessive spring frequency deviation can cause significant vibration amplitude, leading to motion sickness and a poor user experience. Therefore, the constraint is set to ensure that the spring frequency deviation is greater than the first spring frequency deviation threshold and less than the second spring frequency deviation threshold.

[0091] The first and second damping ratio thresholds correspond to the lower and upper limits of the damping ratio, respectively. Considering that a too small damping ratio results in slow vibration attenuation, while a too large damping ratio results in a strong sense of lifting and a poor user experience, the constraint is set to ensure that the damping ratio is greater than the first damping ratio threshold and less than the second damping ratio threshold.

[0092] The reason why the sprung frequency deviation of the front suspension is greater than that of the rear suspension is that for most models, in the Z direction of the vehicle, the center of mass of the vehicle body is approximately in the middle of the front and rear suspensions, and the front seats are close to the center of mass of the vehicle body, while the rear seats are close to the top dead center of the rear suspension. Therefore, the front seats are not particularly sensitive to the vibration of the front and rear suspensions, while the rear seats are more sensitive to the vibration of the rear suspension. Figure 4 As shown in the figure, when the front suspension is impacted, the body movement is such that the rear suspension does not move when the front suspension is impacted. At this time, the displacement of the front seat rail is Approximately the displacement of the front suspension top dead center half of ;like Figure 5 As shown in the figure, for the vehicle body movement when the rear suspension is impacted, when the front and rear suspensions are decoupled, the front suspension does not move when the rear suspension is impacted. At this time, the displacement of the rear seat rail is approximately equal to the displacement of the rear suspension top dead center, that is, If the front and rear suspension parameters are identical, the displacement of the front and rear suspension top dead centers will be approximately equal when going over a speed bump. However, the rear seats will move significantly more than the front seats. Therefore, the rear suspension stiffness should be reduced to mitigate the impact on the vehicle body. Since reducing the rear suspension's deflection frequency will also reduce its stiffness, a configuration with a high front suspension's sprung deflection frequency and a low rear suspension's sprung deflection frequency can better suppress rear suspension vibration.

[0093] The front suspension's sprung frequency deviation is greater than the product of the rear suspension's sprung frequency deviation and the first coefficient, and less than the product of the rear suspension's sprung frequency deviation and the second coefficient. This is because, given that the front suspension's sprung frequency deviation is greater than the rear suspension's sprung frequency deviation, and that the sprung frequency deviations of the front and rear suspensions are similar, the combined vibrations of the front and rear suspensions could produce resonance. Therefore, frequency avoidance is employed to minimize the possibility of this combined vibration.

[0094] The vehicle's pitch angular frequency is lower than the rotation angular frequency in the target direction because people are more sensitive to movement in the pitch direction. By making the pitch angular frequency of the vehicle body lower than the angular frequency in the Z direction, the vibration speed of the vehicle body in the pitch direction can be reduced, thereby improving the riding experience of users in the vehicle.

[0095] The second peak value of the second displacement is smaller than the product of the first peak value and a third coefficient greater than 0 and less than 1, so as to simultaneously stop the vibration attenuation of the front and rear suspensions, thereby further improving the passenger experience.

[0096] For example, the first constraint condition can be referred to formula (9): (9); in, and Represent the sprung masses of the front and rear suspensions respectively; and They represent the angular frequencies of the vehicle body in the pitch direction and the Z direction respectively when the pitch motion is decoupled from the Z direction motion; Indicates the second peak of rear seat rail displacement; The spring deviation of the front and rear suspension is to between, and They correspond to the first spring frequency deviation threshold and the second spring frequency deviation threshold respectively; the front and rear suspension damping ratio is to between, and They correspond to the first damping ratio threshold and the second damping ratio threshold respectively; the frequency deviation of the front suspension spring is greater than the frequency deviation of the rear suspension spring; the frequency deviation of the front suspension spring and the frequency deviation of the rear suspension spring avoid frequency deviation to , as well as They correspond to the first coefficient and the second coefficient respectively; the pitch angular frequency of the vehicle body in the pitch direction is less than the angular frequency in the Z direction; when the rear wheel passes the speed bump, the second peak value of the rear seat is less than the first peak value and The product of Corresponding to the third coefficient.

[0097] For example, and The determination method can be found in formula (10): (10); and The determination method can be found in formula (11): (11); in, is the suspension mass distribution coefficient, The determination method can be found in formula (12): (12).

[0098] It is understandable that, during implementation, the first constraint condition may include at least one of the above-mentioned constraints. The more constraints are combined, the better the effect of the corresponding target suspension parameters in suppressing the vibration of the vehicle under speed bump conditions.

[0099] In an embodiment of the present application, by setting at least one first constraint condition, the vibration suppression effect of the vehicle under speed bump conditions based on the target suspension parameters determined based on the first constraint condition can be further improved; while comprehensively considering the sprung frequency deviation, damping ratio and pitch angle frequency, the overall controllability and comfort of the vehicle when passing over speed bumps can be further balanced, providing users with a smoother and more comfortable driving experience.

[0100] In some embodiments, the suspension system includes a vibration damping component, and the suspension parameter determination method may further include the following steps S13 to S15: Step S13: Acquire multiple groups of second damping forces that meet the second constraint condition and correspond to at least two target relative speeds; the target relative speed is the relative speed between the two ends of the vibration reduction assembly.

[0101] Here, a vibration damping assembly is a component used to suppress the vibration response of the sprung mass by providing a damping force. Examples include, but are not limited to, hydraulic shock absorbers, pneumatic shock absorbers, and electromagnetic shock absorbers. The relative velocity between the ends of the vibration damping assembly is the difference between the velocities at the upper and lower ends of the suspension shock absorber. A relative velocity between -1 m / s and 1 m / s covers the range of relative velocities achievable under most operating conditions.

[0102] During implementation, the relative speed between the two ends of the suspension shock absorber may be related to the weight of the vehicle body. The greater the weight, the greater the relative speed between the two ends of the suspension shock absorber may be.

[0103] The target relative speed is a preset value selected from the relative movement speeds that may occur at both ends of the vibration reduction assembly as the vibration reduction assembly is compressed and stretched during the operation of the vibration reduction assembly.

[0104] Illustratively, the target relative speed may be -1 m / s, -0.5 m / s, 0.3 m / s, 0.6 m / s, 1 m / s, etc., which is not limited in the embodiments of the present application.

[0105] In some embodiments, the at least two target relative speeds may include at least two relative speeds that are not zero.

[0106] The second constraint condition can be used to limit the damping force provided by the vibration reduction assembly. For example, the second constraint condition can include a constraint that directly limits the value of the damping force (such as the damping force range), or a constraint that limits the value of a parameter that determines the damping force (such as the damping coefficient range, energy dissipation power, etc.) to indirectly limit the damping force.

[0107] It should be noted that the first damping force and the second damping force described in the embodiment of the present application include the first damping force and the second damping force of the front suspension, and the first damping force and the second damping force of the rear suspension. Since the principles of obtaining the first damping force and the second damping force of the front suspension, and the first damping force and the second damping force of the rear suspension are the same, each group of first damping force and second damping force described below is a unilateral damping force on one side of the front suspension or the rear suspension, and the corresponding steps and methods are applicable to at least any one side of the front suspension and the rear suspension.

[0108] Step S14: for each group of second damping forces corresponding to at least two target relative velocities, determine the second target parameter corresponding to the current group of second damping forces; the second target parameter is determined based on the first damping force and the second damping force, the first damping force is determined based on the first damping coefficient corresponding to the target damping ratio, and the first damping coefficient does not change with the relative speed at both ends of the vibration reduction assembly.

[0109] Here, the first damping coefficient does not change with the relative speed at both ends of the vibration damping assembly, and the first damping force is determined based on the first damping coefficient and the relative speed at both ends of the vibration damping assembly. Therefore, the first damping force changes linearly from small to large with the relative speed at both ends of the vibration damping assembly.

[0110] The second target parameter is a quantitative indicator used to measure the effect of a set of damping forces on vehicle vibration control. The smaller the second target parameter is, the better the performance of the set of second damping forces corresponding to the second target parameter in controlling vehicle vibration.

[0111] Each target relative speed corresponds to a second damping force, and the second damping forces corresponding to different target relative speeds may be the same or different. Based on the second damping forces and the first damping force corresponding to each group of at least two target relative speeds, the second target parameters corresponding to the group of second damping forces can be determined.

[0112] Step S15: Determine the one with the smallest second target parameter corresponding to each group of second damping forces as the target damping force corresponding to the vibration reduction assembly and the at least two target relative speeds; when the relative speed at both ends of the vibration reduction assembly is less than 0, the value of the target damping force corresponding to the relative speed is less than the value of the corresponding first damping force; when the relative speed at both ends of the vibration reduction assembly is greater than 0, the value of the target damping force corresponding to the relative speed is greater than the value of the corresponding first damping force.

[0113] The damping assembly provides a smaller damping coefficient during compression, thereby providing a smaller damping force, which can reduce the lifting sensation when going over speed bumps. During extension, it provides a larger damping coefficient, thereby providing a larger damping force, which can accelerate energy dissipation. During the extension phase, when the relative velocity between the two ends of the damping assembly is greater than zero, the damping force is greater than during the compression phase, when the relative velocity between the two ends of the damping assembly is less than zero. Therefore, designing the curve of the damping force variation with the relative velocity between the two ends of the suspension shock absorber to be nonlinear can achieve better vibration damping performance when the vehicle goes over speed bumps.

[0114] In some implementations, an optimization model may be used to minimize the second target parameter to achieve determination of the target damping force.

[0115] In this embodiment, multiple second damping force combinations that satisfy the second constraint are introduced and optimized based on the second target parameter to determine the optimal target damping force. This reduces the damping force during the compression phase of the damping assembly to reduce the sense of lift when the vehicle passes over speed bumps, improving ride comfort. Increases the damping force during the extension phase of the damping assembly to accelerate energy dissipation and vibration attenuation, thereby achieving a balance between comfort and handling when the vehicle is operating over speed bumps. This effectively suppresses the vehicle's body vibration response when passing over speed bumps, improving the user's driving experience.

[0116] In some embodiments, determining the second target parameter corresponding to the current set of second damping forces in step S14 may include the following steps S141 to S143: Step S141: Determine a first region based on a target relative speed interval and a first trajectory of a first damping force changing with at least two target relative speeds.

[0117] Here, the target relative speed range is the range of relative motion speeds that can occur at both ends of the vibration damping assembly as it compresses and stretches during operation. The target relative speed range can be determined based on the vehicle's driving conditions. For example, for more oscillating conditions such as driving over speed bumps or other bumpy roads, the target relative speed range can be larger than that for driving over smoother roads.

[0118] In some embodiments, the target relative speed interval may be a preset relative speed range corresponding to common operating conditions, for example, the target relative speed interval may be from -0.6 m / s to 0.6 m / s.

[0119] Because the first damping force varies linearly with the relative velocity between the two ends of the vibration damping assembly, the trajectory of the first damping force in the rectangular coordinate system formed by the relative velocity and the damping force corresponds to the damping force output by the vibration damping assembly at different relative velocities. By fitting the first damping forces corresponding to multiple target relative velocities, a first trajectory that reflects the characteristics of the vibration damping assembly can be obtained.

[0120] In some embodiments, the at least two target relative speeds used to determine the first trajectory may include relative speeds within at least two target relative speed intervals, and a relative speed outside the target relative speed interval.

[0121] For example, multiple key speed points can be established within the relative speed range of -1 m / s to 1 m / s at both ends of the vibration damping assembly, and the first damping force corresponding to each key speed point can be determined, thereby obtaining the first trajectory corresponding to each key speed point. Specifically, for working conditions of greater concern, the target relative speed range can be greater than -0.6 m / s and less than 0.6 m / s, with the corresponding target relative speeds being 0, ±0.05 m / s, ±0.1 m / s, ±0.3 m / s, ±0.6 m / s, and ±1 m / s. Similarly, the second trajectory in step S142 can be obtained by determining the second damping force corresponding to each key speed point.

[0122] For example, the target relative speed corresponding to the key speed point is 0, 、 、 、 、 、 、 、 、 as well as and damping force 、 、 、 、 、 、 、 、 as well as As shown in Table 1, the first damping force and the second damping force corresponding to the same target relative speed are different, that is, for the first damping force and the second damping force, Corresponding different.

[0123] Table 1

[0124] In the rectangular coordinate system formed by the relative velocity and damping force at both ends of the vibration damping assembly, the first region is a graphical region surrounded by the upper and lower boundaries of the target relative velocity range, the first trajectory, and the velocity axis of the relative velocity at both ends of the vibration damping assembly.

[0125] Step S142: Determine a second region based on the target relative speed interval and a second trajectory of a current set of second damping forces changing with at least two target relative speeds.

[0126] Here, because the second damping force varies nonlinearly from small to large as the relative speed at both ends of the vibration damping assembly increases, the trajectory of the second damping force change, i.e., the second trajectory, can correspond to a damping force curve or broken line output by the vibration damping assembly at different relative speeds. By fitting the second damping forces corresponding to multiple target relative speeds, a damping force curve or broken line that reflects the characteristics of the vibration damping assembly can be obtained. Determining the second region based on the target relative speed range and the second trajectory means that the second region determined based on the target relative speed range and the second trajectory corresponds one-to-one to the second trajectory, and different second trajectories correspond to different second regions, rather than limiting the order in which the second trajectory and the second region are determined.

[0127] It can be understood that, for the second trajectory, the greater the number of target relative speeds, the smoother the curve corresponding to the second trajectory, and the better the effect of the second damping force determined based on the second trajectory on improving the comfort of the vibration reduction process.

[0128] In some implementations, a smoother second trajectory may be obtained through interpolation.

[0129] For example, the first damping force and the second damping force are respectively related to the first trajectory and the second trajectory corresponding to the target relative speed in Table 1 in step S141 as follows: Figure 6 shown.

[0130] In some embodiments, the optimal interpolation curve of the second trajectory can be obtained by optimizing the target relative speeds, for example, by increasing the number of target relative speeds or selecting a target relative speed corresponding to a specific operating condition.

[0131] In some embodiments, when the target damping force is determined using an optimization model, the design variable may correspond to a second damping force that varies with the target relative speed.

[0132] Step S143: determine the absolute value of the difference between the first area of ​​the first region and the second area of ​​the second region as the second target parameter corresponding to the current set of second damping forces; the first area represents the first vibration attenuation power corresponding to the first damping force within the target relative speed range, and the second area represents the second vibration attenuation power corresponding to the second damping force within the target relative speed range.

[0133] Since vibration attenuation is achieved through energy dissipation, and the energy dissipation capacity of the vibration reduction assembly is determined by the damping force and the relative speed at both ends, by determining the areas of the first region and the second region, the energy dissipation capacity of the vibration reduction assembly corresponding to the first damping force and the second damping force, respectively, at different relative speeds can be intuitively reflected.

[0134] The absolute value of the difference between the first area of ​​the first region and the second area of ​​the second region can represent the difference in energy dissipation between linear and nonlinear changes of the damping force with the target relative speed within the target relative speed range, that is, the difference in vibration attenuation power.

[0135] It can be understood that a smaller difference in vibration attenuation power indicates closer approximation between the linear and nonlinear variations in damping force with the target relative velocity, i.e., closer vibration cessation times. Therefore, by minimizing the second target parameter, the vibration attenuation power before and after the equivalent transition from linear to nonlinear variations in damping force with the relative velocity at both ends of the vibration reduction assembly can be equal or approximately equal, resulting in approximately the same vibration cessation times for the vehicles before and after the equivalent transition.

[0136] In some embodiments, since the damping ratio can be determined by the damping coefficient and the sprung frequency deviation, after obtaining the target sprung frequency deviation and the target damping ratio according to the above-mentioned suspension parameter determination method, the first damping coefficient corresponding to the first damping force can be determined, and the first damping force can be further obtained based on the first damping coefficient and the target relative speed.

[0137] For example, the optimization model in which the design variable in step S142 corresponds to the second damping force that varies with the target relative speed can be expressed as a second optimization model. In the target relative speed range greater than -0.6 m / s and less than 0.6 m / s, the objective function of the second optimization model can be referred to in formula (13): (13); in, Corresponding to the first area above, Corresponding to the second area above, and with Figure 6 The damping force corresponding to the relative velocity of each target 、 、 、 、 、 、 、 、 as well as is the design variable.

[0138] In this embodiment of the present application, a first region and a second region are constructed based on the target relative speed range and the damping force variation trajectory, and the absolute value of the area difference between the first region and the second region is calculated as the second target parameter. This allows the damping force to vary nonlinearly with the relative speed at both ends of the vibration damping assembly, achieving a balance between comfort and handling of the vehicle under speed bump conditions. This ensures that the vibration attenuation power before and after the equivalent damping (from linear to nonlinear) is equal or approximately equal. In other words, the movement of the front and rear suspensions can still be stopped approximately simultaneously, further improving the control of the vehicle's vibration response under speed bump conditions.

[0139] In some embodiments, the second constraint includes: The slope of a line connecting corresponding points of each two adjacent target relative speeds on the second trajectory of at least two target relative speeds satisfies a target slope condition; the target slope condition indicates that when the target relative speed is less than 0, the value of the second damping force corresponding to the target relative speed is less than the value of the corresponding first damping force; when the target relative speed is greater than 0, the value of the second damping force corresponding to the target relative speed is greater than the value of the corresponding first damping force.

[0140] Here, the target slope condition is used to constrain the rationality of the second damping force that varies with the target relative speed. This can improve the smoothness and continuity of the damping force curve corresponding to the second trajectory. This reduces unstable or unreasonable vibration responses caused by sudden changes in the curve while ensuring that the second damping force varies nonlinearly with the relative speed, thereby improving vehicle comfort and handling.

[0141] It can be understood that the slope of the line connecting the corresponding points of each two adjacent target relative velocities on the second trajectory of at least two target relative velocities actually corresponds to the damping coefficient of the second damping force. By setting the target slope condition, when the shock absorber enters the compression stage during vehicle driving, the damping force can be reduced by lowering the damping coefficient, thereby alleviating the impact felt by the passengers and improving ride comfort; when the shock absorber enters the extension stage, the damping force can be reduced by increasing the damping coefficient, thereby quickly suppressing the vibration of the vehicle body.

[0142] For example, in combination with the key speed points in Table 1, to The slope of the line connecting the two points is , to The slope of the line connecting the two points is , to The slope of the line connecting the two points is , to The slope of the line connecting the two points is , to The slope of the line connecting the two points is ; to The slope of the line connecting the two points is , to The slope of the line connecting the two points is , to The slope of the line connecting the two points is , to The slope of the line connecting the two points is , to The slope of the line connecting the two points is The first damping coefficient can be expressed as , for and The target slope condition corresponding to the second constraint condition can be found in formula (14): (14); It should be noted that the values ​​of the target slope conditions in the embodiment of the present application are merely examples of magnitude relationships, which are used to make the nonlinear curve corresponding to the second trajectory closer to the expected effect, rather than limiting specific values.

[0143] In this embodiment, a target slope condition is set, and the relationship between the second damping force and the first damping force is adjusted based on the positive or negative value of the target relative velocity (i.e., the extension and contraction phase of the damping assembly). This reduces the sense of lift during the compression phase of the damping assembly, improving ride comfort. During the extension phase of the damping assembly, energy dissipation is increased, rapidly damping body vibrations and thus improving controllability of vehicle vibration damping. At the same time, the movement of the front and rear suspensions can still be stopped nearly simultaneously.

[0144] The present application also proposes a suspension parameter determination device, such as Figure 7 As shown, the suspension parameter determination device 700 includes: The first acquisition unit 710 is configured to acquire a displacement time response of a vehicle body in a target direction under a speed bump condition; the speed bump condition indicates that the vehicle passes through a target speed bump, and the target direction is perpendicular to the ground. A first determination unit 720 is configured to determine a set of target suspension parameters for the suspension system with the goal of minimizing a first target parameter; the first target parameter is determined based on a displacement-time response of the vehicle body in the target direction under the speed bump condition and suspension parameters of the suspension system; the first target parameter at least characterizes the vibration response of the vehicle in the target direction under the speed bump condition; the target suspension parameters include a target sprung frequency deviation and a target damping ratio.

[0145] In some embodiments, the displacement-time response is determined based on the displacement excitation and velocity excitation of the vehicle's wheels by the target speed bump, and a dynamic model of the vehicle's suspension system, and the displacement excitation and velocity excitation are determined based on size parameters of the target speed bump.

[0146] In some embodiments, the first acquisition unit is further used to: determine the displacement excitation and velocity excitation of the vehicle's wheels by the target speed bump based on a first function characterizing the size parameters of the target speed bump; and determine the displacement time response of the vehicle's body in the target direction under the speed bump working condition corresponding to the target speed bump based on the displacement excitation and velocity excitation of the vehicle's wheels and the dynamic model of the suspension system.

[0147] In some embodiments, the displacement time response of the vehicle body in the target direction includes a first displacement of the front seat rail of the vehicle in the target direction and a second displacement of the rear seat rail of the vehicle in the target direction, and the first target parameter is determined based on the peak and valley values ​​of the first displacement and the peak and valley values ​​of the second displacement, or is determined based on the peak and valley values ​​of the first displacement, the peak and valley values ​​of the second displacement, and the height of the upper limit position of the suspension system.

[0148] In some embodiments, the suspension parameters include sprung deflection frequency and damping ratio; The first determination unit is further configured to: obtain multiple sets of sprung frequency deviations and damping ratios that satisfy a first constraint condition; determine, for each set of sprung frequency deviations and damping ratios, the first target parameters corresponding to a current set of the sprung frequency deviations and damping ratios; determine the smallest of the first target parameters corresponding to the sets of sprung frequency deviations and damping ratios as the target sprung frequency deviation and the target damping ratio; and determine target suspension parameters based on the target sprung frequency deviations and the target damping ratios.

[0149] In some embodiments, the first determination unit is further configured to: determine a first sub-target parameter, a second sub-target parameter, a third sub-target parameter, a fourth sub-target parameter, and a fifth sub-target parameter under the speed bump working condition based on a current set of the sprung frequency deviation and the damping ratio; the first sub-target parameter includes a first peak value of the first displacement, the second sub-target parameter includes an absolute value of a difference between a second valley value after the second peak value of the first displacement and a third peak value, the third sub-target parameter includes a first peak value of the second displacement, the fourth sub-target parameter includes an absolute value of a difference between a second valley value after the second peak value of the second displacement and the third peak value, and the fifth sub-target parameter includes a maximum absolute value of a difference between a height of an upper limit position of a front suspension and a height of an upper limit position of a rear suspension of the suspension system; and sum the first sub-target parameter, the second sub-target parameter, the third sub-target parameter, the fourth sub-target parameter, and the fifth sub-target parameter to obtain a first target parameter corresponding to the current set of the sprung frequency deviation and the damping ratio.

[0150] In some embodiments, the first constraint includes at least one of the following: The sprung frequency deviation is greater than a first sprung frequency deviation threshold and less than a second sprung frequency deviation threshold; the sprung frequency deviation includes the sprung frequency deviation of the front suspension and the sprung frequency deviation of the rear suspension; The damping ratio is greater than a first damping ratio threshold and less than a second damping ratio threshold; the damping ratio includes a damping ratio of the front suspension and a damping ratio of the rear suspension; The sprung frequency deviation of the front suspension is greater than the sprung frequency deviation of the rear suspension; The sprung frequency deviation of the front suspension is greater than the product of the sprung frequency deviation of the rear suspension and a first coefficient, and less than the product of the sprung frequency deviation of the rear suspension and a second coefficient; the second coefficient is greater than the first coefficient, and both the first coefficient and the second coefficient are greater than 1; The pitch angular frequency of the vehicle is less than the rotation angular frequency of the target direction; The second peak value of the second displacement is less than the product of the first peak value and a third coefficient; and the third coefficient is greater than 0 and less than 1.

[0151] In some embodiments, the suspension system includes a vibration reduction assembly; The first acquisition unit is further configured to: acquire multiple sets of second damping forces corresponding to at least two target relative speeds that satisfy a second constraint condition; the target relative speed is a relative speed between two ends of the vibration reduction assembly; The first determination unit is also used to: determine, for each group of second damping forces corresponding to at least two target relative speeds, a second target parameter corresponding to the current group of second damping forces; the second target parameter is determined based on the first damping force and the second damping force, the first damping force is determined based on the first damping coefficient corresponding to the target damping ratio, and the first damping coefficient does not change with the relative speed at both ends of the vibration reduction assembly; determine the one with the smallest second target parameter corresponding to each group of the second damping forces as the target damping force corresponding to the vibration reduction assembly and at least two target relative speeds; when the relative speed at both ends of the vibration reduction assembly is less than 0, the value of the target damping force corresponding to the relative speed is less than the corresponding value of the first damping force; when the relative speed at both ends of the vibration reduction assembly is greater than 0, the value of the target damping force corresponding to the relative speed is greater than the corresponding value of the first damping force.

[0152] In some embodiments, the first determination unit is further used to: determine a first area based on the target relative speed interval and a first trajectory of the first damping force changing with the at least two target relative speeds; determine a second area based on the target relative speed interval and a current set of second trajectories of the second damping force changing with the at least two target relative speeds; determine the absolute value of the difference between the first area of ​​the first area and the second area of ​​the second area as the second target parameter corresponding to the current set of the second damping forces; the first area represents the first vibration attenuation power corresponding to the first damping force within the target relative speed interval, and the second area represents the second vibration attenuation power corresponding to the second damping force within the target relative speed interval.

[0153] In some embodiments, the second constraint condition includes: the slope of the line connecting the corresponding points of each two adjacent target relative speeds on the second trajectory of the at least two target relative speeds satisfies a target slope condition; the target slope condition indicates that when the target relative speed is less than 0, the value of the second damping force corresponding to the target relative speed is less than the corresponding value of the first damping force; when the target relative speed is greater than 0, the value of the second damping force corresponding to the target relative speed is greater than the corresponding value of the first damping force.

[0154] For the dynamic model of vehicle vibration, it is assumed that the front and rear suspensions are approximately decoupled, that is, the suspension mass distribution coefficient , after decoupling the Z-direction vibration of the front and rear suspensions, the free vibration equation of the single-degree-of-freedom system can be found in formula (15): (15); in, is the damping ratio, is the natural frequency when the damping is 0 (the periodic vibration frequency determined only by the internal mass distribution and elastic properties when the vibration system is free to vibrate), is the initial displacement, is the initial velocity, is the vibration time, is the displacement of free vibration.

[0155] Assumptions is the height of a wave peak, After one cycle The height of adjacent peaks, is the period of free vibration, then and The relationship can be found in formula (16): (16); In this case, the logarithmic attenuation coefficient, which describes the degree of amplitude decay during free vibration, The determination method can be found in formula (17): (17).

[0156] According to formula (17), the logarithmic attenuation coefficient increases with the increase of the damping ratio. and natural frequency Therefore, the smaller the natural frequency is, the larger the logarithmic attenuation coefficient is.

[0157] Assuming the sprung mass of the rear quarter of the vehicle is 1500 / 4kg and the damping coefficient of the shock absorber is 2000 N∙s / m, for two free vibration systems with sprung offset frequencies of 1.2Hz and 1.5Hz, the initial velocity is zero and the initial displacements are 12mm and 15mm, respectively. The smaller the sprung offset frequency, the lower the suspension stiffness and the smaller the first peak of displacement when going over a speed bump.

[0158] like Figure 8 As shown in the formula (15), the free vibration response (displacement response) of the single degree of freedom system under the conditions of sprung deflection frequency of 1.2 Hz and 1.5 Hz can be obtained, that is, .according to Figure 8 It can be concluded that for the model with a small sprung deflection frequency, although the free vibration period becomes longer, the decay is faster because its initial displacement value is small and the logarithmic attenuation coefficient is large.

[0159] The embodiment of the present application provides a method for determining suspension parameters to better control the transient response of the vehicle body under speed bump conditions and to achieve the engineering requirements of rapid attenuation of the vehicle body vibration response, such as Figure 9As shown, the suspension parameter determination method may include the following steps S21 to S24: Step S21: Establish a suspension system dynamics model under speed bump working conditions.

[0160] During implementation, the process of establishing the dynamic model can refer to formula (1) in the above suspension parameter determination method.

[0161] Step S22: Calculate the displacement time response of the seat rail under the speed bump working condition based on the dynamic model.

[0162] During implementation, the process of calculating the displacement time response of the seat rail under speed bump conditions based on the dynamic model can be referred to formulas (2) to (7) in the above-mentioned suspension parameter determination method.

[0163] Step S23: Establish a first optimization model to solve the sprung deflection frequency and damping ratio of the front and rear suspensions based on the displacement time response of the seat rail under the speed bump working condition.

[0164] During implementation, a first optimization model is established. The process of solving the sprung deflection frequency and damping ratio of the front and rear suspensions based on the displacement time response of the seat rail under speed bump conditions can be referred to formulas (8) to (12) in the above-mentioned suspension parameter determination method.

[0165] Step S24: Establish a second optimization model, and solve the nonlinear damping curve of the suspension shock absorber based on the sprung deflection frequency and damping ratio of the front and rear suspensions.

[0166] Here, the suspension shock absorber may correspond to the vibration reduction component in the above suspension parameter determination method, and the nonlinear damping curve may correspond to the curve corresponding to the second trajectory in the above suspension parameter determination method.

[0167] During implementation, a second optimization model is established. The process of solving the nonlinear damping curve of the suspension shock absorber based on the sprung deflection frequency and damping ratio of the front and rear suspensions can be referred to formulas (13) to (14) in the above-mentioned suspension parameter determination method.

[0168] In an embodiment of the present application, a suspension system dynamics model under speed bump conditions and a first optimization model are established to obtain a corresponding set of sprung frequency deviations and damping ratios for the front and rear suspensions. This rapidly dampens the vibrations of the front and rear suspensions, causing them to stop vibrating approximately simultaneously, while reducing the rear seat vibration and vehicle body pitch vibration under speed bump conditions. Furthermore, a second optimization model is established to obtain a nonlinear damping curve for the suspension shock absorber based on the sprung frequency deviations and damping ratios of the front and rear suspensions. This reduces the impact of the suspension on the springs under speed bump conditions, ensuring that the vibration attenuation power before and after the damping force is converted from linear to nonlinear is approximately equal. This improves the control effect on the vehicle body transient response under speed bump conditions while rapidly damping the vehicle body vibration response, balancing vehicle comfort and handling, and providing users with a better driving experience.

[0169] For example, in combination Figure 2 as well as Figure 3 , the relevant parameters are: 、 、 、 、 、 、 、 、 、 、 、 、 、 、 In the case of , combined with the above-mentioned first optimization model for parameter optimization, the optimal solution of sprung frequency deviation can be obtained as: 、 、 、 .

[0170] Compared with the other two options, option 1: 、 、 、 Option 2: 、 、 、 The Z displacement of the front seat rail, the Z displacement of the rear seat rail, and the pitch angle displacement of the vehicle body are as follows: Figure 10 、 Figure 11 、 Figure 12 Comparing the amplitude and convergence time, the optimized solution corresponding to the embodiment of the present application is better than solutions one and two, with lower displacement amplitude and faster convergence time.

[0171] For example, taking the shock absorber of the rear suspension as an example, the linear damping coefficient obtained by optimization is 1541.9 N∙s / m. The linear damping is converted nonlinearly according to the second optimization model obtained by formula (13), and the optimal damping force curve is obtained as follows: Figure 13 As shown in FIG, in the corresponding relationship between the two damping forces and the relative speed, the optimized nonlinear damping can correspond to the above-mentioned optimal damping force curve.

[0172] Therefore, the suspension parameter determination method provided in the embodiment of the present application can better suppress the first peak of the front and rear seat displacement when the vehicle passes through a speed bump, while quickly attenuating the vibration of the vehicle body. It can also convert linear damping into nonlinear damping, further reducing the lifting feeling while ensuring that the vibration attenuation power remains unchanged.

[0173] The present application also proposes a parameter adjustment method, such as Figure 14 As shown, the parameter adjustment method includes the following steps S31 to S33: Step S31: In response to the presence of a target speed bump within a target distance along the vehicle's driving direction, obtaining a displacement time response of the vehicle body in the target direction under a speed bump working condition; the speed bump working condition indicates that the vehicle travels over the target speed bump with the target direction perpendicular to the ground.

[0174] Here, the target distance may be a preset maximum distance for which the suspension parameters of the suspension system need to be adjusted. If a target speed bump exists within the target distance along the vehicle's travel direction, it indicates that the vehicle will pass the target speed bump if it continues traveling in the current travel direction.

[0175] In some implementations, it may be determined based on radar data, image data, etc. whether there is a target speed bump within a target distance along the vehicle's travel direction.

[0176] For example, while the vehicle is traveling, an image acquisition component carried by the vehicle can be used to capture images of the vehicle's environment, and based on the captured images, it can be determined whether there is a target speed bump within a target distance along the vehicle's driving direction.

[0177] For example, while the vehicle is driving, a three-dimensional map of the vehicle's location can be obtained through a radar component installed on the vehicle or a road test system, and based on the three-dimensional map, it can be determined whether there is a target speed bump within a target distance along the vehicle's driving direction.

[0178] In some embodiments, the displacement time response is determined based on the displacement excitation and velocity excitation of the vehicle's wheels by the target speed bump and a dynamic model of the vehicle's suspension system, and the displacement excitation and velocity excitation are determined based on size parameters of the target speed bump.

[0179] Step S32: Determine a set of target suspension parameters for the suspension system with the goal of minimizing a first target parameter; the first target parameter is determined based on the displacement-time response and suspension parameters of the suspension system, and the first target parameter at least represents the vibration response of the vehicle in a target direction under a speed bump condition. The target suspension parameters include a target sprung frequency deviation and a target damping ratio.

[0180] Step S33: Adjust the current suspension parameters of the suspension system to target suspension parameters.

[0181] Here, by adjusting the current suspension parameters of the suspension system to the target suspension parameters, the suspension parameters of the suspension system can be determined and adjusted before the vehicle passes through the target speed bump. As a result, when the vehicle passes through the target speed bump, the suspension system performs vibration control based on the target suspension parameters that can minimize the vibration response of the vehicle under the speed bump condition.

[0182] In an embodiment of the present application, in response to the presence of a target speed bump within a target distance along the vehicle's travel direction, the displacement time response of the vehicle body in the target direction under a speed bump condition is obtained. A first target parameter is constructed based on the displacement time response and suspension parameters. A set of optimal target suspension parameters is determined with the goal of minimizing the first target parameter, and the current suspension parameters of the suspension system are then adjusted to the target suspension parameters. Thus, by optimizing the first target parameter based on the displacement time response of the vehicle body in the target direction under the speed bump condition, a corresponding set of target sprung deflection frequency and target damping ratio are obtained as target suspension parameters. Furthermore, based on this set of target suspension parameters, the vehicle's suspension system can minimize the vibration response of the vehicle under the speed bump condition, thereby improving the effectiveness of suppressing vehicle vibration under the speed bump condition, reducing the likelihood of violent oscillations and significant jumps in the vehicle, and thereby improving vehicle controllability and comfort.

[0183] The present application also proposes a parameter adjustment device, such as Figure 15 As shown, the parameter adjustment device 1500 includes: The second acquisition unit 1510 is configured to: in response to a target speed bump existing within a target distance along a driving direction of the vehicle, acquire a displacement time response of a vehicle body in a target direction under a speed bump operating condition; the speed bump operating condition indicates that the vehicle is traveling over the target speed bump, and the target direction is perpendicular to the ground; a second determining unit 1520 configured to determine a set of target suspension parameters of the suspension system with the goal of minimizing a first target parameter; the first target parameter being determined based on the displacement-time response and suspension parameters of the suspension system, the first target parameter representing at least a vibration response of the vehicle in the target direction under the speed bump condition; the target suspension parameters including a target sprung frequency deviation and a target damping ratio; The adjusting unit 1530 is configured to adjust the current suspension parameters of the suspension system to the target suspension parameters.

[0184] In some embodiments, the displacement-time response is determined based on the displacement excitation and velocity excitation of the vehicle's wheels by the target speed bump, and a dynamic model of the vehicle's suspension system, and the displacement excitation and velocity excitation are determined based on size parameters of the target speed bump.

[0185] The embodiment of the present application provides an electronic device, including: a memory and a processor. Figure 16 As shown, the electronic device 1600 includes: Memory 1610 , for storing computer programs that can be executed on processor 1620 ; The processor 1620 is configured to execute the program stored in the memory 1610 to implement the above method.

[0186] An embodiment of the present application further proposes a computer program, comprising computer-readable code. When the computer-readable code is executed in a computer device, a processor in the computer device executes some or all of the steps for implementing the above method.

[0187] An embodiment of the present application provides a computer program product, including a computer program or instructions, which, when executed by a processor, implements some or all of the steps in the above method.

[0188] An embodiment of the present application provides a computer-readable storage medium, which stores a computer program. The computer program can be executed by a processor to implement the above method.

[0189] The present application is described with reference to the flowcharts and / or block diagrams of the methods, apparatuses and devices according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0190] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0191] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0192] The above is only a specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in this application should be covered by the scope of protection of the present application.

[0193] The description of the above device embodiment is similar to the description of the above method embodiment and has similar beneficial effects as the method embodiment. For technical details not disclosed in the device embodiment of this application, please refer to the description of the method embodiment of this application for understanding.

[0194] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The above-mentioned serial numbers of the embodiments of the present application are for description only and do not represent the advantages and disadvantages of the embodiments.

[0195] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0196] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0197] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units; they may be located in one place or distributed across multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the embodiment of the present application.

[0198] In addition, all functional units in the embodiments of the present application can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the above-mentioned integrated units can be implemented in the form of hardware or in the form of hardware plus software functional units.

[0199] Those skilled in the art will understand that all or part of the steps of the above-mentioned method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above-mentioned method embodiment; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM), magnetic disks or optical disks, and other media that can store program codes.

[0200] Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application, or the part that contributes to the relevant technology, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0201] The above embodiments are merely exemplary embodiments for fully illustrating the present application, and the protection scope of the present application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art based on the present application are within the protection scope of the present application.

Claims

1. A method for determining suspension parameters, characterized in that: include: Obtain the displacement time response of the vehicle body in the target direction under the speed bump condition; The speed bump operating condition represents the vehicle traveling over a target speed bump, the target direction being perpendicular to the ground, the displacement-time response being determined based on displacement excitation and velocity excitation of the vehicle's wheels by the target speed bump, and a dynamic model of the vehicle's suspension system, the displacement excitation and velocity excitation being determined based on dimensional parameters of the target speed bump; A set of target suspension parameters for the suspension system is determined with the goal of minimizing a first target parameter; the first target parameter is determined based on the displacement-time response and suspension parameters of the suspension system, the first target parameter at least characterizing the vibration response of the vehicle in the target direction under the speed bump condition, the target suspension parameters including a target sprung frequency deviation and a target damping ratio.

2. The method for determining suspension parameters according to claim 1, wherein: The displacement time response of the vehicle body in the target direction includes a first displacement of the front seat rail of the vehicle in the target direction and a second displacement of the rear seat rail of the vehicle in the target direction, and the first target parameter is determined based on the peak and valley values ​​of the first displacement and the peak and valley values ​​of the second displacement, or based on the peak and valley values ​​of the first displacement, the peak and valley values ​​of the second displacement, and the height of the upper limit position of the suspension system.

3. The method for determining suspension parameters according to claim 2, wherein: The suspension parameters include sprung deflection frequency and damping ratio; and determining a set of target suspension parameters of the suspension system with the goal of minimizing the first target parameter includes: Obtaining multiple sets of sprung deflection frequencies and damping ratios that satisfy the first constraint condition; For each set of sprung frequency deviation and damping ratio, determining the first target parameter corresponding to the current set of the sprung frequency deviation and the damping ratio; Determining the smallest first target parameter among each set of sprung frequency deviations and damping ratios as the target sprung frequency deviations and the target damping ratio; Target suspension parameters are determined based on the target sprung deflection frequency and the target damping ratio.

4. The method for determining suspension parameters according to claim 3, wherein: The determining of the first target parameter corresponding to a current set of the sprung deflection frequency and the damping ratio includes: determining, based on a current set of the sprung deflection frequency and the damping ratio, a first sub-target parameter, a second sub-target parameter, a third sub-target parameter, a fourth sub-target parameter, and a fifth sub-target parameter under the speed bump operating condition; the first sub-target parameter comprising a first peak value of the first displacement, the second sub-target parameter comprising an absolute value of a difference between a second valley value after the second peak value of the first displacement and a third peak value, the third sub-target parameter comprising a first peak value of the second displacement, the fourth sub-target parameter comprising an absolute value of a difference between a second valley value after the second peak value of the second displacement and the third peak value, and the fifth sub-target parameter comprising a maximum absolute value of a difference between a height of an upper limit position of a front suspension and a height of an upper limit position of a rear suspension of the suspension system; The first sub-target parameter, the second sub-target parameter, the third sub-target parameter, the fourth sub-target parameter, and the fifth sub-target parameter are summed to obtain a current set of first target parameters corresponding to the sprung frequency deviation and the damping ratio.

5. The method for determining suspension parameters according to claim 4, characterized in that: The first constraint condition includes at least one of the following: The sprung frequency deviation is greater than a first sprung frequency deviation threshold and less than a second sprung frequency deviation threshold; the sprung frequency deviation includes the sprung frequency deviation of the front suspension and the sprung frequency deviation of the rear suspension; The damping ratio is greater than a first damping ratio threshold and less than a second damping ratio threshold; the damping ratio includes a damping ratio of the front suspension and a damping ratio of the rear suspension; The sprung frequency deviation of the front suspension is greater than the sprung frequency deviation of the rear suspension; The sprung frequency deviation of the front suspension is greater than the product of the sprung frequency deviation of the rear suspension and the first coefficient, and less than the product of the sprung frequency deviation of the rear suspension and the second coefficient; The second coefficient is greater than the first coefficient, and both the first coefficient and the second coefficient are greater than 1; The pitch angular frequency of the vehicle is less than the rotation angular frequency of the target direction; The second peak value of the second displacement is less than the product of the first peak value and a third coefficient; and the third coefficient is greater than 0 and less than 1.

6. The method for determining suspension parameters according to any one of claims 1 to 5, characterized in that: The suspension system includes a vibration damping component, and the suspension parameter determination method further includes: Acquire multiple sets of second damping forces corresponding to at least two target relative velocities that satisfy a second constraint condition; the target relative velocities are relative velocities at both ends of the vibration reduction assembly; determining, for each set of second damping forces corresponding to at least two target relative velocities, a second target parameter corresponding to the current set of second damping forces; the second target parameter being determined based on the first damping force and the second damping force, the first damping force being determined based on a first damping coefficient corresponding to the target damping ratio, the first damping coefficient being invariant to changes in the relative velocity between the two ends of the vibration reduction assembly; The one with the smallest second target parameter corresponding to each group of the second damping forces is determined as the target damping force corresponding to the vibration reduction assembly and at least two target relative speeds respectively; when the relative speed at both ends of the vibration reduction assembly is less than 0, the value of the target damping force corresponding to the relative speed is less than the corresponding value of the first damping force; when the relative speed at both ends of the vibration reduction assembly is greater than 0, the value of the target damping force corresponding to the relative speed is greater than the corresponding value of the first damping force.

7. The method for determining suspension parameters according to claim 6, characterized in that: The determining of the second target parameters corresponding to the current set of the second damping forces includes: determining a first region based on the target relative speed interval and a first trajectory of the first damping force changing with the at least two target relative speeds; determining a second region based on the target relative speed interval and a current set of second trajectories of the second damping force changing with the at least two target relative speeds; The absolute value of the difference between the first area of ​​the first region and the second area of ​​the second region is determined as the second target parameter corresponding to the current set of the second damping force; the first area represents the first vibration attenuation power corresponding to the first damping force within the target relative speed range, and the second area represents the second vibration attenuation power corresponding to the second damping force within the target relative speed range.

8. The method for determining suspension parameters according to claim 7, wherein: The second constraint condition includes: The slope of a line connecting corresponding points on the second trajectory of each two adjacent target relative speeds among the at least two target relative speeds satisfies a target slope condition; the target slope condition indicates that when the target relative speed is less than 0, the value of the second damping force corresponding to the target relative speed is less than the value of the corresponding first damping force; when the target relative speed is greater than 0, the value of the second damping force corresponding to the target relative speed is greater than the value of the corresponding first damping force.

9. A parameter adjustment method, characterized in that: include: In response to a target speed bump existing within a target distance along a driving direction of the vehicle, obtaining a displacement time response of a vehicle body in the target direction under a speed bump working condition; The speed bump operating condition represents the vehicle traveling over the target speed bump, the target direction is perpendicular to the ground, the displacement time response is determined based on the displacement excitation and velocity excitation of the vehicle's wheels by the target speed bump, and a dynamic model of the vehicle's suspension system, the displacement excitation and velocity excitation being determined based on dimensional parameters of the target speed bump; determining a set of target suspension parameters for the suspension system with the goal of minimizing a first target parameter; the first target parameter is determined based on the displacement-time response and suspension parameters of the suspension system, the first target parameter at least characterizing the vibration response of the vehicle in the target direction under the speed bump condition; the target suspension parameters include a target sprung frequency deviation and a target damping ratio; The current suspension parameters of the suspension system are adjusted to the target suspension parameters.

10. A suspension parameter determination device, characterized in that: The suspension parameter determination device comprises: a first acquisition unit configured to acquire a displacement time response of a vehicle body in a target direction under a speed bump operating condition; the speed bump operating condition representing the vehicle traveling over a target speed bump, the target direction being perpendicular to the ground, the displacement time response being determined based on a displacement excitation and a velocity excitation of the vehicle wheels by the target speed bump, and a dynamic model of the vehicle's suspension system, the displacement excitation and the velocity excitation being determined based on dimensional parameters of the target speed bump; a first determination unit, configured to determine a set of target suspension parameters of the suspension system with the goal of minimizing a first target parameter; the first target parameter being determined based on the displacement-time response and suspension parameters of the suspension system, the first target parameter at least characterizing a vibration response of the vehicle in the target direction under the speed bump condition, the target suspension parameters including a target sprung frequency deviation and a target damping ratio.

11. A parameter adjustment device, characterized in that: The parameter adjustment device comprises: a second acquisition unit configured to, in response to the presence of a target speed bump within a target distance along a driving direction of the vehicle, acquire a displacement time response of a vehicle body in a target direction under a speed bump operating condition; the speed bump operating condition characterizing the vehicle traveling over the target speed bump, the target direction being perpendicular to the ground, the displacement time response being determined based on a displacement excitation and a velocity excitation of the vehicle wheels by the target speed bump, and a dynamic model of a suspension system of the vehicle, the displacement excitation and the velocity excitation being determined based on dimensional parameters of the target speed bump; a second determination unit, configured to determine a set of target suspension parameters of the suspension system with the goal of minimizing a first target parameter; the first target parameter being determined based on the displacement-time response and suspension parameters of the suspension system, the first target parameter representing at least a vibration response of the vehicle in the target direction under the speed bump condition; the target suspension parameters including a target sprung frequency deviation and a target damping ratio; An adjusting unit is configured to adjust current suspension parameters of the suspension system to target suspension parameters.

12. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the computer program, the steps in the method according to any one of claims 1 to 9 are implemented.

13. A computer-readable storage medium, characterized in that A computer program is stored thereon, and when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

14. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

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