Suspension parameter determination methods and devices, parameter adjustment methods and devices, equipment

Abstract

This application relates to a method and apparatus for determining suspension parameters, a method and apparatus for adjusting parameters, and equipment. The method includes acquiring the displacement-time response of the vehicle body in a target direction perpendicular to the ground under speed bump conditions; the speed bump condition characterizes the vehicle traveling over a target speed bump, and the displacement-time response is determined based on the displacement and velocity excitations of the target speed bump on the wheels, as well as a dynamic model of the suspension system; the displacement and velocity excitations are determined based on the dimensional parameters of the target speed bump; target suspension parameters of the suspension system are 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, and the first target parameter at least characterizes the vibration response of the vehicle in the target direction under speed bump conditions. This application can reduce the possibility of severe oscillations and large jumps in the vehicle by minimizing the vibration response, thereby improving the vehicle's controllability, comfort, and the adaptability of the target suspension parameters to the speed bump condition.

Description

Technical Field

[0001] This application relates to the field of vehicle noise, vibration, and harshness (NVH) and dynamics control, specifically to a method and apparatus for determining suspension parameters, a method and apparatus for adjusting parameters, and equipment. Background Technology

[0002] In related technologies, when designing suspension parameters, the damping ratio is usually determined based on a fixed sprung frequency. However, the resulting suspension parameters lack theoretical support and are difficult to balance between comfort and handling. When the vehicle goes over speed bumps, improper sprung frequency settings in the rear suspension can cause strong vibrations in the rear seats, potentially leading to violent oscillations and significant bouncing, thus affecting the user's driving and riding experience. Summary of the Invention

[0003] This application provides a method and apparatus for determining suspension parameters, a method and apparatus for adjusting parameters, and a device that can better suppress the violent oscillations and large jumps of a vehicle when it goes over speed bumps, thereby further improving the user's driving experience.

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0005] A method for determining suspension parameters, comprising:

[0006] The displacement-time response of the vehicle body in the target direction is obtained under the condition of speed bumps. The condition of speed bumps represents the vehicle driving through the 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's wheels by the target speed bump, as well as the 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.

[0007] With the goal of minimizing the first target parameter, a set of target suspension parameters for the suspension system is determined. The first target parameter is determined based on the displacement-time response and the 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 the target sprung frequency and the target damping ratio.

[0008] Based on the aforementioned technical means, by acquiring the vehicle's displacement-time response in the target direction under speed bump conditions, and constructing a first target parameter 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 parameter. Thus, by considering the vehicle's displacement-time response in the target direction under speed bump conditions and optimizing the first target parameter, a set of corresponding target sprung frequency and target damping ratio can be obtained as target suspension parameters. Furthermore, by utilizing the vehicle's suspension system based on this set of target suspension parameters, the vibration response of the vehicle under speed bump conditions can be minimized, improving the effect of suppressing vehicle vibration under speed bump conditions, reducing the possibility of severe oscillations and large jumps, thereby improving vehicle controllability and comfort. In addition, by determining the vehicle's displacement-time response in the target direction based on the vehicle tire displacement and velocity excitation, combined with the dynamic model of the suspension system, the accuracy of the vehicle's displacement-time response 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 conditions corresponding to the target speed bump.

[0009] In some implementations, the time response of the vehicle body displacement in the target direction includes a first displacement of the front seat rails in the target direction and a second displacement of the rear seat rails in the target direction. The first target parameter is determined based on the peak and trough values ​​of the first displacement and the second displacement, or it is determined based on the peak and trough values ​​of the first displacement, the peak and trough values ​​of the second displacement, and the height of the upper limit position of the suspension system.

[0010] Based on the aforementioned technical means, in this embodiment of the application, a first target parameter is constructed by combining the displacements of the front and rear seat guide rails in the target direction, or by combining the displacements of the front and rear seat guide rails in the target direction with the upper limit position of the suspension system. This not only improves the accuracy of describing the vehicle's dynamic response characteristics based on multi-dimensional vibration response parameters, but also provides more reliable data support for subsequent suspension parameter optimization.

[0011] In some implementations, the suspension parameters include sprung frequency and damping ratio; a set of target suspension parameters for the suspension system is determined with the objective of minimizing a first target parameter, including:

[0012] Obtain multiple sets of sprung frequencies and damping ratios that satisfy the first constraint condition;

[0013] For each set of sprung frequency and damping ratio, determine the first target parameter corresponding to the current set of sprung frequency and damping ratio;

[0014] The smallest first target parameter among the groups of spring-loaded frequency and damping ratio is determined as the target spring-loaded frequency and target damping ratio.

[0015] The target suspension parameters are determined based on the target sprung frequency and the target damping ratio.

[0016] Based on the aforementioned technical means, by acquiring multiple sets of sprung frequencies and damping ratios that satisfy the first constraint condition, a first target parameter is calculated for each set of sprung frequencies and damping ratios, and the set that minimizes the first target parameter is selected as the target sprung frequency and target damping ratio. In this way, the vibration response of the vehicle when crossing speed bumps can be controlled according to different combinations of sprung frequencies and damping ratios. Furthermore, based on the target sprung frequency and target damping ratio that minimizes the first target parameter and better meets the expected effect, target suspension parameters are determined, thereby improving the suppression of vibration when the vehicle crosses speed bumps, reducing the possibility of severe oscillations and large jumps, and ultimately improving the user's driving experience.

[0017] In some implementations, determining a first target parameter corresponding to the current set of sprung frequencies and damping ratios includes:

[0018] Based on the current set of sprung frequencies and damping ratios, determine the first, second, third, fourth, and fifth sub-target parameters under the speed bump condition. The first sub-target parameter includes the first peak value of the first displacement; the second sub-target parameter includes the absolute value of the difference between the second valley value of the first displacement after the second peak value and the third peak value; the third sub-target parameter includes the first peak value of the second displacement; the fourth sub-target parameter includes the absolute value of the difference between the second valley value of the second displacement after the second peak value and the third peak value; and the fifth sub-target parameter includes the maximum value of the absolute value of the difference between the height of the upper limit position of the front suspension and the height of the upper limit position of the rear suspension.

[0019] 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 the first target parameter corresponding to the current set of sprung frequency and damping ratio.

[0020] Based on the aforementioned technical means, by summing multiple sub-target parameters to obtain the first target parameters corresponding to each set of sprung frequencies and damping ratios, on the one hand, the impact of suspension parameters on the vehicle's dynamic performance in terms of vibration under speed bump conditions can be evaluated more comprehensively, thereby enabling faster and more accurate acquisition of the first target parameters corresponding to each set of sprung frequencies and damping ratios; 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 can be found that can better suppress vehicle vibration without sacrificing much ride comfort.

[0021] In some implementations, the first constraint includes at least one of the following:

[0022] The sprung frequency is greater than the first sprung frequency threshold and less than the second sprung frequency threshold; the sprung frequency includes the sprung frequency of the front suspension and the sprung frequency of the rear suspension;

[0023] The damping ratio is greater than the first damping ratio threshold and less than the second damping ratio threshold; the damping ratio includes the damping ratio of the front suspension and the damping ratio of the rear suspension.

[0024] The sprung frequency of the front suspension is greater than that of the rear suspension;

[0025] The sprung frequency of the front suspension is greater than the product of the sprung frequency of the rear suspension and the first coefficient, and less than the product of the sprung frequency of the rear suspension and the second coefficient; the second coefficient is greater than the first coefficient, and both the first and second coefficients are greater than 1;

[0026] The vehicle's pitch frequency is less than the rotation frequency in the target direction;

[0027] 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.

[0028] Based on the above technical means, by setting at least one first constraint condition, the effect of the target suspension parameters determined based on the first constraint condition on the vibration suppression of the vehicle under speed bump conditions can be further improved; by comprehensively considering the sprung frequency, damping ratio and pitch frequency, the overall controllability and comfort of the vehicle when going over speed bumps can be further balanced, providing users with a smoother and more comfortable driving experience.

[0029] In some implementations, the suspension system includes damping components, and the method for determining suspension parameters further includes:

[0030] Obtain multiple sets of second damping forces that satisfy the second constraint conditions and correspond to at least two target relative velocities respectively; the target relative velocities are the relative velocities at both ends of the vibration damping component;

[0031] For each set of second damping forces corresponding to at least two target velocities, determine the 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 the first damping coefficient corresponding to the target damping ratio, and the first damping coefficient does not change with the relative velocity at both ends of the vibration damping component;

[0032] The smallest of the second target parameters corresponding to each group of second damping forces is determined as the target damping force corresponding to the relative velocities between the vibration damping component and at least two targets respectively; when the relative velocity at both ends of the vibration damping component is less than 0, the value of the target damping force corresponding to the relative velocity is less than the value of the corresponding first damping force; when the relative velocity at both ends of the vibration damping component is greater than 0, the value of the target damping force corresponding to the relative velocity is greater than the value of the corresponding first damping force.

[0033] Based on the aforementioned technical means, by introducing multiple combinations of second damping forces that satisfy the second constraint conditions and optimizing their selection based on the second target parameters, the optimal target damping force is determined. This allows for reducing the damping force during the compression phase of the damping component to decrease the lifting sensation when the vehicle passes over speed bumps, thus improving ride comfort. Conversely, increasing the damping force during the tension phase of the damping component accelerates energy dissipation and vibration decay, thereby achieving a balance between vehicle comfort and handling under speed bump conditions. This further effectively suppresses the vehicle body vibration response generated when passing over speed bumps, improving the user's driving experience.

[0034] In some implementations, determining the second target parameters corresponding to the current set of second damping forces includes:

[0035] Based on the target relative velocity range and the first trajectory of the first damping force changing with the relative velocities of the at least two targets, a first region is determined;

[0036] Based on the target relative velocity range and the second trajectory of the current set of second damping forces as the relative velocities of the at least two targets change, a second region is determined;

[0037] 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 second damping forces; the first area represents the first vibration attenuation power corresponding to the first damping force in the target relative velocity range, and the second area represents the second vibration attenuation power corresponding to the second damping force in the target relative velocity range.

[0038] Based on the aforementioned technical means, a first region and a second region are constructed based on the target relative velocity range and the damping force change trajectory. The absolute value of the area difference between the first region and the second region is calculated as a second target parameter. This allows for a balance between vehicle comfort and handling under speed bump conditions, while ensuring that the damping force changes non-linearly with the relative velocity at both ends of the damping component, thus making the vibration attenuation power before and after the damping (from linear to non-linear) equivalent equal or approximately equal. In other words, the movement of the front and rear suspensions can still stop approximately simultaneously, further improving the vibration response control effect of the vehicle under speed bump conditions.

[0039] In some implementations, the second constraint includes:

[0040] At least two target relative velocities must satisfy the target slope condition by connecting the points corresponding to any two adjacent target relative velocities on the second trajectory. The target slope condition indicates that when the target relative velocity is less than 0, the value of the second damping force corresponding to the target relative velocity is less than the value of the corresponding first damping force; when the target relative velocity is greater than 0, the value of the second damping force corresponding to the target relative velocity is greater than the value of the corresponding first damping force.

[0041] Based on the aforementioned technical means, by setting a target slope condition and adjusting the magnitude relationship between the second damping force and the first damping force according to the sign of the target relative velocity (i.e., the extension / contraction phase of the damping component), the feeling of lift can be reduced during the compression phase of the damping component, improving ride comfort; during the extension phase of the damping component, the energy dissipation capacity can be improved, rapidly attenuating vehicle vibration, thereby improving the controllability of vehicle damping, while simultaneously allowing the movement of the front and rear suspensions to stop approximately simultaneously.

[0042] A parameter adjustment method, comprising:

[0043] 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's body in the target direction under the speed bump condition is obtained. The speed bump condition characterizes the vehicle traveling through the target speed bump, with the target direction perpendicular to the ground. The displacement-time response is determined based on the displacement and velocity excitations of the vehicle's wheels by the target speed bump, as well as the dynamic model of the vehicle's suspension system. The displacement and velocity excitations are determined based on the dimensional parameters of the target speed bump.

[0044] With the goal of minimizing the first target parameter, a set of target suspension parameters for the suspension system is determined. The first target parameter is determined based on the displacement-time response and the 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 the target sprung frequency and the target damping ratio.

[0045] Adjust the current suspension parameters of the suspension system to the target suspension parameters.

[0046] A suspension parameter determining device, comprising:

[0047] The first acquisition unit is used to: acquire the displacement time response of the vehicle body in the target direction under the speed bump condition; the speed bump condition represents the vehicle driving through the target speed bump, the target direction is perpendicular to the ground, and the displacement time response is determined based on the displacement excitation and velocity excitation of the vehicle's wheels by the target speed bump, as well as the dynamic model of the vehicle's suspension system, and the displacement excitation and velocity excitation are determined based on the size parameters of the target speed bump;

[0048] The first determining unit is used to: determine a set of target suspension parameters of the suspension system with the goal of minimizing the first target parameter; the first target parameter is determined based on the displacement-time response of the vehicle body in the target direction under the speed bump condition and the suspension parameters of the suspension system, and the first target parameter at least characterizes the vibration response of the vehicle in the target direction under the speed bump condition, and the target suspension parameters include the target sprung frequency and the target damping ratio.

[0049] A parameter adjustment device, comprising:

[0050] The second acquisition unit is used to acquire the displacement time response of the vehicle body in the target direction under the speed bump condition in response to the existence of a target speed bump at a target distance along the vehicle's driving direction. The speed bump condition represents the vehicle driving through the 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's wheels by the target speed bump, as well as the dynamic model of the vehicle's suspension system. The displacement excitation and velocity excitation are determined based on the size parameters of the target speed bump.

[0051] The second determining unit is used to determine a set of target suspension parameters of the suspension system with the goal of minimizing the first target parameter; the first target parameter is determined based on the displacement-time response and the suspension parameters of the suspension system, and the first target parameter at least characterizes the vibration response of the vehicle in the target direction under the speed bump condition, and the target suspension parameters include the target sprung frequency and the target damping ratio;

[0052] The adjustment unit is used to adjust the current suspension parameters of the suspension system to the target suspension parameters.

[0053] An electronic device includes a memory and a processor, the memory storing a computer program that can run on the processor, the processor executing the program to implement the method described above.

[0054] A computer-readable storage medium storing a computer program that can be executed by a processor to implement the above-described method.

[0055] A computer program product includes a computer program or instructions that, when executed by a processor, implement some or all of the steps in the above-described method.

[0056] The beneficial effects of this application are:

[0057] (1) By considering the displacement time response of the vehicle body in the target direction under the speed bump condition, the first target parameters can be optimized to obtain a set of corresponding target sprung frequency and target damping ratio as target suspension parameters. Furthermore, by using the vehicle's suspension system based on this 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 the vehicle experiencing severe oscillations and large jumps, and improving the vehicle's controllability and comfort. 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 tires and combined with 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, as well as the adaptability of the target suspension parameters to the speed bump condition corresponding to the target speed bump.

[0058] (2) It can improve the accuracy of describing the dynamic response characteristics of the vehicle body based on multi-dimensional vibration response parameters, and can also provide more reliable data support for subsequent suspension parameter optimization;

[0059] (3) It can improve the accuracy of describing the dynamic response characteristics of the vehicle body based on multi-dimensional vibration response parameters, and can also provide more reliable data support for subsequent suspension parameter optimization;

[0060] (4) The vibration response of the vehicle when passing over speed bumps can be controlled according to different combinations of sprung frequency and damping ratio. Furthermore, the target suspension parameters can be determined according to a set of target sprung frequency and target damping ratio that minimizes the first target parameter and better meets the expected effect, thereby improving the suppression of vibration when the vehicle passes over speed bumps, improving the possibility of suppressing violent oscillations and large jumps, and thus improving the user's driving experience.

[0061] (5) On the one hand, the impact of suspension parameters on the vehicle's dynamic performance in terms of vibration under speed bump conditions can be evaluated more comprehensively, so that the first target parameters corresponding to each set of sprung 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 vibration without sacrificing a lot of ride comfort can be found.

[0062] (6) By setting at least one first constraint, the effect of the target suspension parameters determined based on the first constraint on the vibration of the vehicle under the speed bump condition can be further improved; by comprehensively considering the sprung frequency, damping ratio and pitch frequency, the overall controllability and comfort of the vehicle when going over the speed bump can be further balanced, providing users with a smoother and more comfortable driving experience.

[0063] (7) It can reduce the damping force during the compression stage of the damping component to reduce the lifting feeling when the vehicle passes through the speed bump and improve the ride comfort. It can increase the damping force during the tension stage of the damping component to accelerate energy dissipation and vibration decay, thereby achieving a balance between the comfort and handling of the vehicle under the speed bump condition, further effectively suppressing the body vibration response generated when the vehicle passes through the speed bump, and improving the user's driving experience.

[0064] (8) It can make the damping force change nonlinearly with the relative speed at both ends of the damping component and achieve a balance between the comfort and handling of the vehicle under speed bump conditions. It can also make the vibration attenuation power before and after the damping (from linear to nonlinear) equivalent equal or approximately equal, that is, the movement of the front and rear suspensions can still stop approximately at the same time, further improving the vibration response control effect of the vehicle under speed bump conditions.

[0065] (9) It can reduce the feeling of lifting during the compression phase of the damping component and improve ride comfort; it can improve the energy dissipation capacity during the stretch phase of the damping component, quickly attenuate the body vibration, and thus improve the control of vehicle damping. At the same time, it can make the movement of the front and rear suspensions stop almost simultaneously. Attached Figure Description

[0066] Figure 1 A schematic diagram of the implementation process of a suspension parameter determination method provided in this application embodiment. Figure 1 ;

[0067] Figure 2 This is a schematic diagram of a dynamic model of a suspension system provided in an embodiment of this application;

[0068] Figure 3 A schematic diagram of a speed bump provided in an embodiment of this application;

[0069] Figure 4 This application provides a schematic diagram of vehicle body movement when the front suspension is subjected to an impact.

[0070] Figure 5 This application provides a schematic diagram of vehicle body movement when the rear suspension is subjected to an impact.

[0071] Figure 6 A schematic diagram illustrating the relationship between damping force and relative velocity at a key velocity point, provided in an embodiment of this application;

[0072] Figure 7 This is a schematic diagram of the composition structure of a suspension parameter determination device provided in an embodiment of this application;

[0073] Figure 8 This application provides a schematic diagram of the free vibration response of a single-degree-of-freedom system with different on-spring deflection frequencies, as an embodiment of the present application.

[0074] Figure 9 A schematic diagram of the implementation process of a suspension parameter determination method provided in this application embodiment. Figure 2 ;

[0075] Figure 10 A schematic diagram illustrating the displacement of the front seat guide rail under speed bump conditions, provided as an embodiment of this application;

[0076] Figure 11 A schematic diagram illustrating the displacement of the rear seat guide rail under speed bump conditions, provided as an embodiment of this application;

[0077] Figure 12 A schematic diagram illustrating the displacement of the vehicle body pitch angle under speed bump conditions, provided as an embodiment of this application;

[0078] Figure 13 A schematic diagram comparing the linear damping and the optimized nonlinear damping of a vibration damper provided in an embodiment of this application;

[0079] Figure 14 A schematic diagram illustrating the implementation process of a parameter adjustment method provided in this application embodiment;

[0080] Figure 15 This is a schematic diagram of the composition structure of a parameter adjustment device provided in an embodiment of this application;

[0081] Figure 16 This is a schematic diagram of the composition structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0082] The embodiments of this application will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be understood that the preferred embodiments are only for illustrating this application and are not intended to limit the scope of protection of this application.

[0083] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0084] The sprung frequency and damping ratio of a suspension system are crucial parameters. The sprung frequency characterizes the free vibration frequency of the sprung components after an impact, serving as one of the parameters to measure the suspension system's ability to control vehicle vibrations. The damping ratio characterizes the decay rate of the suspension system's free vibrations, representing the speed at which energy is dissipated during free vibration. A higher damping ratio results in faster vibration decay, but an excessively high damping ratio may negatively impact passenger comfort. The sprung frequency is primarily determined by the Z-direction (perpendicular to the ground) stiffness of the suspension (hereinafter referred to as suspension stiffness), the sprung mass, and the sprung mass distribution coefficient, which describes the distribution of sprung mass between the front and rear axles. Given the sprung mass distributed between the front and rear suspensions, the sprung frequencies of the front and rear suspensions are determined by their respective stiffnesses, while the damping ratio is determined by the sprung frequency and the damping coefficient of the shock absorber.

[0085] In related technologies, the common design principle for the sprung frequency of front and rear suspensions is a smaller sprung frequency for the front suspension and a larger sprung frequency for the rear suspension. This design principle may result in insufficient isolation of the rear suspension from unsprung Z-axis impacts, leading to more noticeable impacts on the rear seats when the vehicle goes over speed bumps, causing severe oscillations and significant bouncing, resulting in a poor user experience. The theoretical basis for this "smaller front, larger rear" frequency design is that a larger sprung frequency in the rear suspension results in a shorter free vibration period and faster decay of the sprung portion. This allows the decay process of the rear suspension's free vibration to match that of the front suspension, thus stopping the vibrations of both suspensions simultaneously. However, the actual decay time of the rear suspension's free vibration is determined by a combination of factors, including initial displacement, vehicle speed, track width, damping ratio, and sprung frequency. Therefore, estimating the decay time of free vibration solely based on the sprung frequency is inaccurate.

[0086] Furthermore, for the design of the front and rear suspension damping ratio, related technologies typically involve using simulation software to provide a fixed set of front and rear sprung frequencies, repeatedly varying the damping coefficients of the front and rear suspension shock absorbers, and then conducting multiple trials to obtain the optimal damping ratio, for example, by dividing the damping coefficient by the critical damping coefficient. This method lacks theoretical support and is inefficient, which will affect the progress of related projects.

[0087] Based on this, this application proposes a method for determining suspension parameters, which can be executed by an electronic device. The electronic device refers to a device with data processing capabilities, such as a server, laptop, tablet, desktop computer, smart TV, set-top box, or mobile device (e.g., mobile phone, portable video player, personal digital assistant, dedicated messaging device, portable gaming device). Figure 1 As shown, the method for determining suspension parameters includes the following steps S11 to S12:

[0088] Step S11: Obtain the displacement time response of the vehicle body in the target direction under the speed bump condition; the speed bump condition represents the vehicle driving through the target speed bump, with the target direction perpendicular to the ground.

[0089] Here, the speed bump condition refers to the operating condition corresponding to the process of a vehicle passing over a speed bump at a certain speed. Under the speed bump condition, the front and rear wheels of the vehicle are excited by the road surface successively, resulting in a complex vibration response of the vehicle body, including but not limited to displacement changes at the seat rails, height changes at the limit positions of the suspension system, and changes in the vehicle body pitch angle.

[0090] The target direction is perpendicular to the ground. This is the main vibration direction controlled by the suspension system. Under speed bump conditions, the vibration of the vehicle body is more obvious in this direction.

[0091] Displacement-time response is the dynamic response of the vehicle body's displacement in the vertical direction as a function of time. It reflects the dynamic response characteristics of the suspension system to road surface excitation and is used to optimize suspension parameters.

[0092] In some implementations, the displacement time response may include a curve showing the change of the vertical displacement of the vehicle body (e.g., center of gravity, seat rails, etc.) over time under speed bump conditions.

[0093] In some implementations, the displacement-time response can be determined based on the displacement and velocity excitations of the vehicle's wheels on the target speed bump, as well as the dynamic model of the vehicle's suspension system, whereby the displacement and velocity excitations can be determined based on the dimensional parameters of the target speed bump.

[0094] For example, the vibration process of a vehicle under speed bump conditions can be simulated by establishing a dynamic model. Furthermore, by combining the displacement excitation and velocity excitation of the vehicle's wheels by the target speed bump, the equations corresponding to the dynamics can be solved, thus obtaining at least the displacement time response of the vehicle body in the target direction under speed bump conditions.

[0095] In some implementations, the vibration response of the suspension system may include the vibration response in the target direction and the vibration response in the pitch direction. 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 the speed bump condition.

[0096] For example, such as 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 simulation software; the four degrees of freedom can include the degrees of freedom corresponding to the front wheel vertical (target direction), the rear wheel vertical (target direction), the vehicle body vertical (target direction), and the vehicle body pitch direction, respectively.

[0097] Combination Figure 2 The vibration equation for this model can be found in formula (1):

[0098] (1);

[0099] exist Figure 2 And in formula (1), This indicates the unsprung mass of the front suspension. This indicates the unsprung mass of the rear suspension. Indicates sprung mass (corresponding to vehicle body and powertrain). This indicates that the sprung mass passes through its center of mass. The pitch moment of inertia of the axis (corresponding to the vehicle coordinate system); and These represent the stiffness and damping coefficient of the front tire, respectively. and These represent the stiffness and damping coefficient of the rear tire, respectively. and These represent the stiffness and damping coefficients of the front suspension, respectively. and This indicates the stiffness and damping coefficient of the rear suspension. express The corresponding displacement, express The corresponding displacement, This indicates the displacement of the upper part of the front suspension. This indicates the displacement of the upper part of the rear suspension. express Displacement at the center of mass This indicates the displacement at the front seat rail. Indicates the displacement at the rear seat guide rail; In direction, The distance between the center of gravity and the upper end of the front suspension is The distance between the upper part of the rear suspension and the upper part of the rear suspension is The distance between the front seat guide rail and the upper end of the front suspension is The distance between the rear seat guide rail and the upper end of the rear suspension is , express angular displacement of rotation; and These represent the road surface displacement excitations experienced by the front and rear wheels, respectively. and These represent the road velocity excitations received by the front and rear wheels, respectively. , , as well as They are respectively with , , as well as The corresponding acceleration. Among them, and This can be correlated with the displacement time response of the vehicle body.

[0100] For example, obtain and The process can be found in formula (2):

[0101] (2).

[0102] The sprung frequency of the front suspension is determined based on its stiffness and sprung mass, while the sprung frequency of the rear suspension is determined based on its stiffness and sprung mass. Given the sprung frequency and damping ratio positions of the front and rear suspensions respectively, the corresponding stiffness and damping coefficients of the front and rear suspensions are unknown. It can be included and The formula is used to express this. It can be included and The formula is used to express the displacement-time response of the vehicle body. and It varies with the stiffness and damping coefficient of the front and rear suspensions.

[0103] Step S12: Determine a set of target suspension parameters for the vehicle's suspension system with the goal of minimizing the first target parameter. The first target parameter is determined based on the displacement-time response and the 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 the target sprung frequency and the target damping ratio.

[0104] Here, the first target parameter is a comprehensive evaluation index constructed based on the vehicle's body displacement time response and suspension parameters under speed bump conditions. It is used to quantify the vibration intensity and damping characteristics of the vehicle under speed bump conditions. The smaller the first target parameter, the better the vibration control effect. Therefore, by minimizing the first target parameter, the vibration response of the vehicle in the target direction under speed bump conditions can be optimized. When the first target parameter is minimized, the corresponding suspension parameters (spread frequency and damping ratio) are the target suspension parameters.

[0105] In this embodiment, the displacement-time response of the vehicle body in the target direction under speed bump conditions is obtained, and a first target parameter is constructed based on the displacement-time response and suspension parameters. The optimal set of suspension parameters is determined by minimizing the first target parameter. Thus, by considering the displacement-time response of the vehicle body in the target direction under speed bump conditions and optimizing the first target parameter, a corresponding set of target sprung frequency and target damping ratio can be obtained as target suspension parameters. Furthermore, by utilizing the vehicle's suspension system based on this set of target suspension parameters, the vibration response of the vehicle under speed bump conditions can be minimized, thereby improving the effect of suppressing vehicle vibration under speed bump conditions, reducing the possibility of severe oscillations and large jumps, and thus improving vehicle controllability and comfort.

[0106] In some embodiments, step S11 may include steps S111 to S112:

[0107] Step S111: Based on the first function characterizing the size parameters of the target speed bump, determine the displacement excitation and velocity excitation of the target speed bump on the vehicle's wheels.

[0108] Here, for the scenario of a vehicle passing over a speed bump, the shape of the speed bump can be simulated using functions. For example, a downward-opening quadratic function or a sine wave function can be used to simulate the shape of the speed bump. Using the first function, the contact process between the tires and the road surface when the vehicle passes over the target speed bump can be simulated relatively accurately.

[0109] In some implementations, the form of the first function can be adjusted according to the actual application requirements. For example, a downward-opening quadratic function can better simulate common convex speed bumps, while a sine wave function is more suitable for simulating periodic undulating speed bumps.

[0110] The dimensional parameters characterizing the target speed bump may include, but are not limited to, the width of the speed bump (length of the speed bump cross-section), the height of the speed bump, the slope of the speed bump, and / or the perimeter of the speed bump cross-section.

[0111] Understandably, when choosing a downward-opening quadratic function to fit the shape of the target speed bump, the downward-opening quadratic function has continuous derivatives, making it easier to calculate the displacement and velocity changes of the tire on the target speed bump.

[0112] For example, such as Figure 3 As shown, the speed bump has a length parameter of [missing information]. ,high When the target speed bump is the speed bump, the vehicle speed is Taking the moment when the front wheels begin to go over the speed bump as time zero, the current time can be represented as... The shape of a speed bump is simulated using a downward-opening quadratic function. When a vehicle's wheels are in contact with the speed bump, the speed bump excites the displacement of the front and rear wheels. and and speed incentives and See formula (3):

[0113] (3).

[0114] For example, when the wheels are not in contact with the speed bump, the displacement excitation and velocity excitation of the road surface on the front and rear wheels are both zero, see formula (4):

[0115] (4).

[0116] Step S112: Based on the displacement and velocity excitation of the vehicle's 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 condition corresponding to the target speed bump.

[0117] Here, by combining the displacement excitation of the vehicle's wheels, the velocity excitation of the vehicle's wheels, and the dynamic model of the suspension system, the accuracy of obtaining the displacement-time response of the vehicle body when passing over the target speed bump can be improved.

[0118] For example, in the design For the quality matrix, Here is the damping coefficient matrix. For stiffness matrix, This is the column vector of displacement-time response. When the excitation force is a column vector, the above formula (1) can be expressed in matrix form, see formula (5):

[0119] (5);

[0120] in, , , , as well as See formula (6):

[0121] (6).

[0122] Furthermore, construct vectors ,vector This represents the displacement time response (displacement changing with time) and velocity time response (velocity changing with time) corresponding to the four degrees of freedom, respectively. Combined with formula (6), using vectors... Reducing the order of equation (5) yields equation (7):

[0123] (7);

[0124] in, It is a 4x4 matrix of zeros. It is a 4x4 identity matrix.

[0125] By combining formulas (3) and (4) to solve formula (7), the vector can be obtained. The values ​​of each term are the displacement time response and velocity time response corresponding to each degree of freedom; furthermore, by combining formula (2), the displacement time response of the front seat guide rail and the rear seat guide rail can be obtained, that is... and .

[0126] In this embodiment, the displacement and velocity excitation of the vehicle tires are determined by a first function characterizing the size parameters of the target speed bump, and the displacement-time response of the vehicle body in the target direction is determined by combining the dynamic model of the suspension system. This further improves the accuracy of the displacement-time response of the vehicle body 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 conditions corresponding to the target speed bump.

[0127] In some embodiments, the time response of the vehicle body displacement 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. 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 it 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.

[0128] Here, the front and rear seat rails are located at the front and rear of the vehicle body, respectively, to support the passenger seats and allow them to move longitudinally. When the vehicle traverses complex road conditions such as speed bumps, the displacement of the front and rear seat rails directly reflects the vibration intensity and comfort felt by the occupants. By considering the displacement of the front and rear seat rails in the target direction, the dynamic response characteristics of the overall vehicle body to vibration can be obtained more accurately, thereby better capturing the differences in the riding experience between front and rear passengers.

[0129] The upper limit position of the suspension system, i.e., the top dead center (TDC), typically determines the static height and dynamic travel limit of the suspension. The upper limit position is determined based on the pitch angle displacement. When encountering a speed bump, as the wheel begins to contact the speed bump, the suspension is compressed, and the TDC moves upward relative to the wheel center. The compression travel depends on the height of the speed bump and the suspension stiffness. When the wheel reaches the apex of the speed bump, the suspension compression is at its maximum, and the TDC displacement reaches its extreme value, i.e., the TDC reaches its maximum height. When the wheel leaves the speed bump, the suspension rebounds, and the TDC moves downward to return to its original position. If the damping is insufficient at this point, multiple oscillations may occur. Therefore, by considering the height of the upper limit position of the suspension system, the dynamic response characteristics of the vehicle body to vibrations in the pitch direction can be obtained more accurately.

[0130] Understandably, 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 when it is impacted by a speed bump.

[0131] In this embodiment, a first target parameter is constructed by combining the displacements of the front and rear seat rails in the target direction, or by combining the displacements of the front and rear seat rails in the target direction with the upper limit position of the suspension system. This not only improves the accuracy of the description of the vehicle's dynamic response characteristics based on multi-dimensional vibration response parameters, but also provides more reliable data support for subsequent suspension parameter optimization.

[0132] In some embodiments, suspension parameters include sprung frequency and damping ratio, and step S12 may include steps S121 to S124:

[0133] Step S121: Obtain multiple sets of spring-loaded deflection frequencies and damping ratios that satisfy the first constraint condition.

[0134] Here, the first constraint can be a constraint used to limit the range of the sprung frequency and the damping ratio. For example, the first constraint can include a constraint that directly limits the value of the sprung frequency and / or the damping ratio, or it can include a constraint that limits the parameters associated with the sprung frequency and / or the damping ratio, so as to achieve indirect limitation of the sprung frequency and / or the damping ratio.

[0135] In some implementations, suspension parameters can be determined by using an optimization model to minimize a first objective parameter. This optimization model mainly consists of three parts: design variables, an objective function, and constraints, used to find the optimal solution to the objective function under preset constraints.

[0136] For example, the first optimization model can be used to find a set of design variable values ​​that optimize the first objective function and satisfy a preset first constraint condition. The design variables of the first optimization model are the sprung frequencies corresponding to the front and rear suspensions, respectively. and (Unit: Hz), and the damping ratios of the front and rear suspensions respectively. and .

[0137] Step S122: For each set of spring-loaded deflection frequency and damping ratio, determine the first target parameter corresponding to the current set of spring-loaded deflection frequency and damping ratio.

[0138] Here, the spring-loaded deflection frequency and damping ratio are different for different groups, and the corresponding first target parameters may be different.

[0139] In some implementations, the first target parameter can be a single-dimensional parameter or a fused parameter determined by combining vibration characteristics of multiple dimensions. For example, the first target parameter can be determined based solely on the displacement-time response of the vehicle seat rail, or it can be determined by combining the displacement-time response of the vehicle seat rail and the height of the suspension top dead center.

[0140] For example, the first objective parameter corresponding to the spring-loaded deflection frequency and damping ratio can correspond to the first objective function of the first optimization model in step S121 above.

[0141] Step S123: Determine the target spring-loaded frequency and target damping ratio as the one with the smallest first target parameter among the groups of spring-loaded frequency and damping ratio.

[0142] Understandably, by comparing the vibration response performance of each set of sprung frequencies and damping ratios, the set of sprung frequencies and damping ratios that minimizes the first target parameter among those satisfying the first constraint condition represents the optimal combination for balancing comfort and handling in the vehicle's vibration response under speed bump conditions. For example, the set of sprung frequencies and damping ratios that reduces the vibration amplitude of the rear seats and effectively controls the pitch vibration of the vehicle body is the target sprung frequency and target damping ratio.

[0143] For example, the target spring-loaded frequency and the target damping ratio are the optimal solutions of the objective function of the first optimization model in step S121 above.

[0144] Step S124: Determine the target suspension parameters based on the target sprung frequency and the target damping ratio.

[0145] Here, the current target sprung frequency and target damping ratio can be used as the target suspension parameters, or the final target suspension parameters can be obtained by further optimization based on the current target sprung frequency and target damping ratio.

[0146] For example, the target damping ratio obtained so far can be further optimized. For instance, based on a fixed target damping ratio value, a set of dynamically adjustable target damping ratio values ​​can be determined to obtain an optimized target damping ratio.

[0147] In this embodiment, multiple sets of sprung frequencies and damping ratios satisfying the first constraint condition are obtained. For each set of sprung frequencies and damping ratios, a corresponding first target parameter is calculated, and the set that minimizes the first target parameter is selected as the target sprung frequency and target damping ratio. In this way, the vibration response of the vehicle when crossing speed bumps can be controlled according to different combinations of sprung frequencies and damping ratios. Furthermore, based on the target sprung frequency and target damping ratio that minimizes the first target parameter and better meets the expected effect, target suspension parameters are determined, thereby improving the suppression of vibration when the vehicle crosses speed bumps, reducing the possibility of severe oscillations and large jumps, and ultimately improving the user's driving experience.

[0148] In some embodiments, determining the first target parameters corresponding to the current set of sprung frequencies and damping ratios in step S122 above may include the following steps S1221 to S1222:

[0149] Step S1221: Based on the current set of sprung frequencies and damping ratios, determine the first sub-target parameter, second sub-target parameter, third sub-target parameter, fourth sub-target parameter, and fifth sub-target parameter under the speed bump condition; the first sub-target parameter includes the first peak value of the first displacement, the second sub-target parameter includes the absolute value of the difference between the second valley value and the third peak value of the first displacement after the second peak value, the third sub-target parameter includes the first peak value of the second displacement, the fourth sub-target parameter includes the absolute value of the difference between the second valley value and the third peak value of the second displacement after the second peak value, and the fifth sub-target parameter includes the maximum value of the absolute value of the difference between the height of the upper limit position of the front suspension and the height of the upper limit position of the rear suspension of the suspension system.

[0150] 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 wheels of the vehicle begin to pass over 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 wheels of the vehicle begin to pass over 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 vibration attenuation 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 vibration attenuation 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 suspensions), which can characterize the vibration response of the vehicle body in the pitch direction when passing over the speed bump.

[0151] Step S1222: Summate 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 the first target parameter corresponding to the current set of spring-loaded deflection frequency and damping ratio.

[0152] Understandably, 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, resulting in higher accuracy.

[0153] For example, for the first optimization model in step S121, its corresponding objective function can be to minimize the value of the sum of the five sub-objective parameters. The maximum value of each sub-objective parameter can be represented by the value of a function; where the function corresponding to the first sub-objective parameter is used to represent the first peak value of the front seat guide rail displacement under the condition of the vehicle hitting a speed bump (which can be expressed as...). The function corresponding to the second sub-objective parameter is used to represent the first peak value of the rear seat guide rail displacement (which can be expressed as...). The function corresponding to the third sub-objective parameter is used to represent the absolute value of the height difference between the second valley (the valley after the second peak) and the third peak (the peak after the second valley) of the front seat guide rail displacement (which can be expressed as...). The function corresponding to the fourth sub-objective parameter is used to represent the absolute value of the height difference between the second valley (the valley after the second peak) and the third peak (the peak after the second valley) of the rear seat guide rail displacement (which can be expressed as...). The function corresponding to the fifth sub-objective parameter is used to represent the maximum absolute value of the difference between the heights corresponding to the top dead center of the front suspension and the top dead center of the rear suspension (i.e., the upper limit positions of the front and rear suspensions), which can be expressed as... ).

[0154] Understandably, this is because the oscillating motion is constantly decaying. The smaller the value, the smaller the maximum displacement of the front seat guide rail when the vehicle's front wheels go over a speed bump, resulting in a better user experience. The smaller the value, the smaller the maximum displacement of the rear seat guide rail when the front wheels of the vehicle go over a speed bump, and the better the user experience. The smaller the value, the smaller the change in the displacement of the front seat guide rail, and the better the user experience. The smaller the value, the smaller the displacement of the rear seat guide rail, resulting in a better user experience. It can be determined based on the pitch angle displacement. The smaller the value, the smaller the angular motion in the pitch direction, and the better the user experience. Therefore, , , , as well as The smaller the maximum value of the sum, the better the user experience.

[0155] For example, the method for determining the first optimization model can be found in formula (8):

[0156] (8);

[0157] in, This corresponds to the constraint condition of the first optimization model, i.e., the first constraint condition.

[0158] In this embodiment, the first target parameters corresponding to each set of sprung frequencies and damping ratios are obtained by summing multiple sub-target parameters. On the one hand, the impact of suspension parameters on the dynamic performance of vehicle vibration under speed bump conditions can be evaluated more comprehensively, thereby enabling faster and more accurate acquisition of the first target parameters corresponding to each set of sprung frequencies and damping ratios. 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 can be found that can better suppress vehicle vibration without sacrificing much ride comfort.

[0159] In some embodiments, the first constraint includes at least one of the following:

[0160] The sprung frequency is greater than the first sprung frequency threshold and less than the second sprung frequency threshold; the sprung frequency includes the sprung frequency of the front suspension and the sprung frequency of the rear suspension;

[0161] The damping ratio is greater than the first damping ratio threshold and less than the second damping ratio threshold; the damping ratio includes the damping ratio of the front suspension and the damping ratio of the rear suspension.

[0162] The sprung frequency of the front suspension is greater than that of the rear suspension;

[0163] The sprung frequency of the front suspension is greater than the product of the sprung frequency of the rear suspension and the first coefficient, and less than the product of the sprung frequency of the rear suspension and the second coefficient; the second coefficient is greater than the first coefficient, and both the first and second coefficients are greater than 1;

[0164] The vehicle's pitch frequency is less than the rotation frequency in the target direction;

[0165] 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.

[0166] Here, the first and second sprung frequency thresholds can be considered as the lower and upper limits of the sprung frequency, respectively. Considering that an excessively high sprung frequency would result in excessive suspension stiffness, poor vibration isolation, and a strong lifting sensation, leading to a poor user experience; while an excessively low sprung frequency would result in significant amplitude vibration, causing motion sickness and also a poor experience, the constraint is set to a sprung frequency greater than the first sprung frequency threshold and less than the second sprung frequency threshold.

[0167] The first and second damping ratio thresholds can be considered as the lower and upper limits of the damping ratio, respectively. Here, considering that a damping ratio that is too small results in slow vibration decay, while a damping ratio that is too large leads to a strong lifting sensation and a poor user experience, the constraint is set to a damping ratio greater than the first damping ratio threshold and less than the second damping ratio threshold.

[0168] The sprung frequency of the front suspension is greater than that of the rear suspension. This is because, for most vehicles, the center of gravity of the vehicle is approximately located in the middle of the front and rear suspensions along the Z-direction. Furthermore, the front seats are close to the center of gravity, while the rear seats are close to the top dead center of the rear suspension. Therefore, the front seats are not particularly sensitive to vibrations from the front and rear suspensions, while the rear seats are more sensitive to vibrations from the rear suspension. Figure 4 As shown, regarding the vehicle body motion when the front suspension is impacted, with the front and rear suspensions decoupled, the rear suspension remains stationary when the front suspension is impacted. At this time, the displacement of the front seat guide rail... Approximately the displacement of the top dead center of the front suspension. Half of, that is ;like Figure 5 As shown, regarding the vehicle body motion when the rear suspension is impacted, with the front and rear suspensions decoupled, the front suspension remains stationary when the rear suspension is impacted. In this case, the displacement of the rear seat guide rail is approximately equal to the displacement of the rear suspension's top dead center. When the suspension parameters of the front and rear suspensions are identical, the displacement of the top dead center of the front and rear suspensions is approximately equal when going over speed bumps. The displacement of the rear seats will be significantly greater than that of the front seats. Therefore, the stiffness of the rear suspension should be reduced to mitigate the impact on the vehicle body. Since reducing the rear suspension's frequency of rotation also reduces its stiffness, a configuration with a higher sprung frequency in the front suspension and a lower sprung frequency in the rear suspension will better suppress rear suspension vibrations.

[0169] The sprung frequency of the front suspension is greater than the product of the sprung frequency of the rear suspension and the first coefficient, but less than the product of the sprung frequency of the rear suspension and the second coefficient. This is because, given that the sprung frequency of the front suspension is greater than that of the rear suspension, and the sprung frequencies of the front and rear suspensions are similar, the vibrations of the front and rear suspensions will overlap and cause resonance. Therefore, frequency avoidance reduces the possibility of vibration overlap between the front and rear suspensions.

[0170] The vehicle's pitch frequency is lower than the rotational frequency in the target direction because people are more sensitive to pitch motion. By making the vehicle's pitch frequency lower than the Z-axis angular frequency, the vibration speed of the vehicle in the pitch direction can be reduced, thereby improving the riding experience for passengers.

[0171] The second peak value of the second displacement is less than the product of the first peak value and a third coefficient that is greater than 0 and less than 1. This is used to stop the vibration attenuation of the front and rear suspensions at the same time, further improving the passenger experience.

[0172] For example, the first constraint can be found in formula (9):

[0173] (9);

[0174] in, and These represent the sprung masses of the front and rear suspensions, respectively. and These represent the angular frequencies of the vehicle body in the pitch and Z directions, respectively, when the pitch and Z directions are decoupled. This represents the second peak value of the rear seat guide rail displacement.

[0175] The sprung frequency of the front and rear suspensions is to between, and These correspond to the first sprung frequency threshold and the second sprung frequency threshold, respectively; the front and rear suspension damping ratios are... to between, and These correspond to the first damping ratio threshold and the second damping ratio threshold, respectively; the sprung frequency of the front suspension is greater than that of the rear suspension; the sprung frequencies of the front and rear suspensions are balanced. to , as well as These correspond to the first and second coefficients, respectively; the pitch frequency of the vehicle body in the pitch direction is less than the angular frequency in the Z direction; when the rear wheels go over a speed bump, the second peak value of the rear seat is less than the first peak value and... The product of This corresponds to the third coefficient.

[0176] For example, and The method for determining this can be found in formula (10):

[0177] (10);

[0178] and The method for determining this can be found in formula (11):

[0179] (11);

[0180] in, This is the suspension weight distribution coefficient. The method for determining this can be found in formula (12):

[0181] (12).

[0182] Understandably, in implementation, the first constraint condition may include at least one of the above constraints. The more constraints combined, the better the effect of the determined target suspension parameters on the vehicle's vibration suppression under speed bump conditions.

[0183] In this embodiment of the application, by setting at least one first constraint condition, the effect of the target suspension parameters determined based on the first constraint condition on the vibration suppression of the vehicle under speed bump conditions can be further improved; by comprehensively considering the sprung frequency, damping ratio and pitch frequency, the overall controllability and comfort of the vehicle when going over speed bumps can be further balanced, providing users with a smoother and more comfortable driving experience.

[0184] In some embodiments, the suspension system includes a damping component, and the above-described method for determining suspension parameters may further include the following steps S13 to S15:

[0185] Step S13: Obtain multiple sets of second damping forces that satisfy the second constraint conditions and correspond to at least two target relative velocities respectively; the target relative velocity is the relative velocity between the two ends of the vibration damping component.

[0186] Here, the damping component is a component used to suppress the vibration response of the sprung mass by providing damping force. For example, it may include, but is not limited to, hydraulic dampers, pneumatic dampers, electromagnetic dampers, etc. The relative velocity between the two ends of the damping component is the difference between the upper and lower velocities of the suspension damper. The relative velocity between the two ends of the suspension damper can cover the range of relative velocities achievable under most operating conditions when it is between -1 m / s and 1 m / s.

[0187] During implementation, the relative speed between the two ends of the suspension damper may be related to the vehicle weight; the greater the weight, the greater the relative speed between the two ends of the suspension damper may be.

[0188] The target relative velocity is a preset value selected from the relative motion velocities that may occur at both ends of the vibration damping component during its operation, as the component is compressed and stretched.

[0189] For example, the target relative velocity can be -1m / s, -0.5m / s, 0.3m / s, 0.6m / s, 1m / s, etc., and the embodiments of this application do not limit it.

[0190] In some implementations, the relative velocities of the at least two targets may include at least two relative velocities that are not zero.

[0191] The second constraint can be a constraint that limits the damping force provided by the vibration damping component. For example, the second constraint can include constraints that directly limit the value of the damping force (such as the range of damping force), or constraints that limit the parameter values ​​that determine the damping force (such as the range of damping coefficient, energy dissipation power, etc.) to achieve indirect limitation of the damping force.

[0192] It should be noted that the first damping force and the second damping force described in the embodiments of this 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 principle 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 is the same, each set of first damping force and second damping force described below is a unilateral damping force of one side of the front suspension or one side of the rear suspension, and the corresponding steps and methods are applicable to at least one side of the front suspension and the rear suspension.

[0193] Step S14: For each group of second damping forces corresponding to at least two target 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 velocity at both ends of the vibration damping component.

[0194] Here, the first damping coefficient does not change with the relative velocity at both ends of the vibration damping component, and the first damping force is determined based on the first damping coefficient and the relative velocity at both ends of the vibration damping component. Therefore, the first damping force changes linearly with the relative velocity at both ends of the vibration damping component from small to large.

[0195] 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, the better the performance of the set of second damping forces corresponding to the second target parameter in controlling vehicle vibration.

[0196] Each target relative velocity corresponds to a second damping force. The second damping forces corresponding to different target relative velocities may be the same or different. Based on the second damping forces and the first damping forces corresponding to at least two target relative velocities in each group, the second target parameters corresponding to the second damping forces in that group can be determined.

[0197] Step S15: Determine the target damping force corresponding to the smallest second target parameter among the second damping forces in each group as the target damping force corresponding to the relative velocity between the vibration damping component and at least two target velocities respectively; when the relative velocity at both ends of the vibration damping component is less than 0, the value of the target damping force corresponding to the relative velocity is less than the value of the corresponding first damping force; when the relative velocity at both ends of the vibration damping component is greater than 0, the value of the target damping force corresponding to the relative velocity is greater than the value of the corresponding first damping force.

[0198] The damping component provides a smaller damping coefficient during compression, resulting in a smaller damping force and reducing the lifting sensation when going over speed bumps; and a larger damping coefficient during extension, resulting in a larger damping force and accelerating energy dissipation. During the extension phase (when the relative velocity between the two ends of the damping component 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 component is less than zero). Therefore, designing the damping force as a non-linear curve relative to the relative velocity between the two ends of the suspension damper allows for better damping performance when the vehicle goes over speed bumps.

[0199] In some implementations, the target damping force can be determined by using an optimization model to minimize a second target parameter.

[0200] In this embodiment, multiple combinations of second damping forces satisfying the second constraint are introduced and optimized based on the second target parameter to determine the optimal target damping force. This allows for reducing the damping force during the compression phase of the damping component to decrease the lifting sensation when the vehicle passes over speed bumps, improving ride comfort. Conversely, increasing the damping force during the tension phase accelerates energy dissipation and vibration decay, thus achieving a balance between vehicle comfort and handling under speed bump conditions. This further effectively suppresses the vehicle body vibration response when passing over speed bumps, enhancing the user's driving experience.

[0201] In some embodiments, determining the second target parameter corresponding to the current set of second damping forces in step S14 above may include the following steps S141 to S143:

[0202] Step S141: Determine the first region based on the target relative velocity range and the first trajectory of the first damping force changing with the relative velocities of at least two targets.

[0203] Here, the target relative speed range refers to the range of relative motion speeds that may occur at both ends of the damping component during its operation, due to compression and stretching. 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 road surfaces, the target relative speed range can be larger than the target relative speed range for driving on a smoother road surface.

[0204] In some implementations, the target relative speed range can be a preset relative speed range corresponding to common operating conditions. For example, the target relative speed range can be from -0.6 m / s to 0.6 m / s.

[0205] Since the first damping force changes linearly with the relative velocity at both ends of the vibration damping component, the trajectory of the first damping force in the Cartesian coordinate system formed by the relative velocity and the damping force at both ends of the vibration damping component corresponds to the straight line of the damping force output by the vibration damping component at different relative velocities. By fitting the first damping force corresponding to multiple target relative velocities, a first trajectory that reflects the characteristics of the vibration damping component can be obtained.

[0206] In some implementations, the relative velocities of at least two targets used to determine the first trajectory may include relative velocities within at least two target relative velocity intervals, as well as relative velocities outside the target relative velocity intervals.

[0207] For example, multiple key velocity points can be established within the range of -1 m / s to 1 m / s at both ends of the vibration damping component, and the first damping force corresponding to each key velocity point can be determined to obtain the first trajectory corresponding to each key velocity point. The target relative velocity range of greater than -0.6 m / s and less than 0.6 m / s, which is of greater concern to the working condition, can be 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 velocity point.

[0208] For example, the target relative velocity corresponding to the key velocity point is 0, , , , , , , , , as well as With damping force , , , , , , , , as well as As shown in Table 1, the first damping force and the second damping force corresponding to the relative velocity of the same target are different; that is, for the first damping force and the second damping force, corresponding different.

[0209] Table 1

[0210]

[0211] In the rectangular coordinate system formed by the relative velocity and damping force at both ends of the vibration damping component, the first region is a graphical region bounded 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 component.

[0212] Step S142: Determine the second region based on the target relative velocity range and the second trajectory of the current set of second damping forces changing with the relative velocities of at least two targets.

[0213] Here, since the second damping force changes non-linearly with the relative velocity at both ends of the vibration damping component, the trajectory of the second damping force, i.e., the second trajectory, can correspond to the damping force curve or broken line output by the vibration damping component at different relative velocities. By fitting the second damping force corresponding to multiple target relative velocities, a damping force curve or broken line reflecting the characteristics of the vibration damping component can be obtained. Determining the second region based on the target relative velocity range and the second trajectory means that the second region determined based on the target relative velocity range and the second trajectory corresponds one-to-one with the second trajectory; different second trajectories correspond to different second regions, rather than restricting the determination of the second trajectory and the order of determining the second region.

[0214] It is understandable that for the second trajectory, the more relative velocities of the target, 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.

[0215] In some implementations, a smoother second trajectory can be obtained through interpolation.

[0216] For example, the first damping force and the second damping force correspond to the first trajectory and the second trajectory of the target relative velocity in Table 1 in step S141, respectively. Figure 6 As shown.

[0217] In some implementations, the optimal interpolation curve of the second trajectory can be obtained by optimizing the target relative velocity. For example, this can be achieved by increasing the number of target relative velocities or selecting target relative velocities corresponding to specific operating conditions.

[0218] In some implementations, when the target damping force is determined using an optimization model, the design variable can correspond to a second damping force that varies with the target relative velocity.

[0219] 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 in the target relative velocity range, and the second area represents the second vibration attenuation power corresponding to the second damping force in the target relative velocity range.

[0220] Since vibration attenuation is achieved through energy dissipation, and the energy dissipation capacity of the vibration damping component is determined by the damping force and the relative velocity at both ends, by determining the areas of the first region and the second region, the energy dissipation capacity of the vibration damping component corresponding to the first damping force and the second damping force at different relative velocities can be intuitively reflected.

[0221] The absolute value of the difference between the first area of ​​the first region and the second area of ​​the second region can characterize the difference in energy dissipation between linear and nonlinear changes in damping force with respect to the target relative velocity within the target relative velocity range, i.e., the difference in vibration attenuation power.

[0222] Understandably, the smaller the difference in vibration attenuation power, the closer the vibration attenuation power is to the linear and nonlinear changes in damping force with the target relative velocity, and thus the closer the vibration stopping time is. Therefore, by minimizing the second objective parameter, the vibration attenuation power can be made equal or approximately equal before and after the equivalent transformation of the damping force changing with the relative velocity at both ends of the damping component from linear to nonlinear, thereby making the vibration stopping time of the vehicle approximately the same before and after the equivalent transformation.

[0223] In some implementations, since the damping ratio can be determined by the damping coefficient and the sprung frequency, after obtaining the target sprung frequency and the target damping ratio according to the suspension parameter determination method described above, the first damping coefficient corresponding to the first damping force can be determined, and the first damping force can be obtained further based on the first damping coefficient and the target relative velocity.

[0224] For example, the optimization model in step S142, where the design variable corresponds to the second damping force that varies with the target relative velocity, can be expressed as the second optimization model. Within the target relative velocity range of greater than -0.6 m / s and less than 0.6 m / s, the objective function of the second optimization model can be found in formula (13):

[0225] (13);

[0226] in, Corresponding to the first area mentioned above, Corresponding to the second area mentioned above, and with Figure 6 Damping force corresponding to the relative velocity of each target , , , , , , , , as well as For design variables.

[0227] In this embodiment, a first region and a second region are constructed based on the target relative velocity range and the damping force change trajectory, and the absolute value of the area difference between the first region and the second region is calculated as a second target parameter. This allows for a balance between vehicle comfort and handling under speed bump conditions, while ensuring that the damping force changes non-linearly with the relative velocity at both ends of the damping component, and that the vibration attenuation power before and after the damping (from linear to non-linear) equivalence 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 vibration response control effect of the vehicle under speed bump conditions.

[0228] In some embodiments, the second constraint includes:

[0229] At least two target relative velocities must satisfy the target slope condition by connecting the points corresponding to any two adjacent target relative velocities on the second trajectory. The target slope condition indicates that when the target relative velocity is less than 0, the value of the second damping force corresponding to the target relative velocity is less than the value of the corresponding first damping force; when the target relative velocity is greater than 0, the value of the second damping force corresponding to the target relative velocity is greater than the value of the corresponding first damping force.

[0230] Here, the target slope condition is used to constrain the rationality of the second damping force that varies with the target relative velocity. This can improve the smoothness and continuity of the damping force curve corresponding to the second trajectory. Thus, while making the second damping force change nonlinearly with the relative velocity, it reduces the situation where the vibration response is unstable or unreasonable due to abrupt changes in the curve, thereby improving the vehicle's comfort and handling.

[0231] It is understandable that the slope of the line connecting the points corresponding to any two adjacent relative velocities on the second trajectory actually corresponds to the damping coefficient of the second damping force. By setting the target slope condition, the damping force can be reduced by decreasing the damping coefficient during vehicle operation when the shock absorber enters the compression phase, thereby alleviating the impact felt by passengers and improving ride comfort; and the damping force can be reduced by increasing the damping coefficient during the extension phase, thereby quickly suppressing the vibration of the vehicle body.

[0232] For example, combining the key velocity 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 ratio, and the target slope condition corresponding to the second constraint can be found in formula (14):

[0233] (14);

[0234] It should be noted that the values ​​of the target slope conditions mentioned above in this application embodiment are only given as examples of magnitude relationships, which are used to make the nonlinear curve corresponding to the second trajectory closer to the expected effect, rather than as a limitation on specific values.

[0235] In this embodiment, a target slope condition is set, and the magnitude relationship between the second damping force and the first damping force is adjusted according to the sign of the target relative velocity (i.e., the extension / contraction phase of the damping component). This reduces the feeling of lift during the compression phase of the damping component, improving ride comfort; it also enhances energy dissipation during the extension phase, rapidly attenuating vehicle vibration and thus improving control over vehicle damping. Simultaneously, the movement of the front and rear suspensions can be stopped approximately simultaneously.

[0236] This application also proposes a suspension parameter determination device, such as... Figure 7 As shown, the suspension parameter determining device 700 includes:

[0237] The first acquisition unit 710 is used to: acquire the displacement time response of the vehicle body in the target direction under the condition of speed bump; the condition of speed bump indicates that the vehicle travels through the target speed bump, and the target direction is perpendicular to the ground;

[0238] The first determining unit 720 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 the displacement-time response of the vehicle body in the target direction under the speed bump condition and the 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, and the target suspension parameters include the target sprung frequency and the target damping ratio.

[0239] In some implementations, the displacement-time response is determined based on the displacement and velocity excitations of the vehicle's wheels by the target speed bump, and a dynamic model of the vehicle's suspension system, wherein the displacement and velocity excitations are determined based on the dimensional parameters of the target speed bump.

[0240] In some embodiments, the first acquisition unit is further configured to: determine the displacement excitation and velocity excitation of the target speed bump to the vehicle's wheels 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 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.

[0241] 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. The first target parameter is determined based on the peak and valley values ​​of the first displacement and the second displacement, or it 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.

[0242] In some embodiments, the suspension parameters include sprung frequency and damping ratio;

[0243] The first determining unit is further configured to: acquire multiple sets of sprung frequencies and damping ratios that satisfy the first constraint conditions; for each set of sprung frequencies and damping ratios, determine the first target parameter corresponding to the current set of sprung frequencies and damping ratios; determine the smallest first target parameter among the sets of sprung frequencies and damping ratios as the target sprung frequency and the target damping ratio; and determine the target suspension parameters based on the target sprung frequency and the target damping ratio.

[0244] In some embodiments, the first determining 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 condition based on a current set of sprung frequencies and damping ratios; the first sub-target parameter includes a first peak value of the first displacement, the second sub-target parameter includes the absolute value of the difference between a second valley value and a third peak value of the first displacement after a second peak value, the third sub-target parameter includes a first peak value of the second displacement, the fourth sub-target parameter includes the absolute value of the difference between a second valley value and a third peak value of the second displacement after a second peak value, and the fifth sub-target parameter includes the maximum value of the absolute value of the difference between the height of the upper limit position of the front suspension and the height of the upper limit position of the rear suspension of the suspension system; summing 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 the first target parameter corresponding to the current set of sprung frequencies and damping ratios.

[0245] In some embodiments, the first constraint includes at least one of the following:

[0246] The sprung frequency is greater than a first sprung frequency threshold and less than a second sprung frequency threshold; the sprung frequency includes the sprung frequency of the front suspension and the sprung frequency of the rear suspension;

[0247] The damping ratio is greater than a first damping ratio threshold and less than a second damping ratio threshold; the damping ratio includes the damping ratio of the front suspension and the damping ratio of the rear suspension;

[0248] The sprung frequency of the front suspension is greater than that of the rear suspension;

[0249] The sprung frequency of the front suspension is greater than the product of the sprung frequency of the rear suspension and a first coefficient, and less than the product of the sprung frequency 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;

[0250] The vehicle's pitch frequency is less than the rotation frequency in the target direction;

[0251] 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.

[0252] In some embodiments, the suspension system includes a damping component;

[0253] The first acquisition unit is further configured to: acquire multiple sets of second damping forces that satisfy the second constraint conditions and correspond to at least two target relative velocities respectively; the target relative velocities are the relative velocities at both ends of the vibration damping component;

[0254] The first determining unit is further configured to: for each group of second damping forces corresponding to at least two target relative velocities, determine 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 velocity at both ends of the vibration damping component; determine the smallest second target parameter among the groups of second damping forces as the target damping force corresponding to the relative velocity between the vibration damping component and at least two target velocities; when the relative velocity at both ends of the vibration damping component is less than 0, the value of the target damping force corresponding to the relative velocity is less than the value of the corresponding first damping force; when the relative velocity at both ends of the vibration damping component is greater than 0, the value of the target damping force corresponding to the relative velocity is greater than the value of the corresponding first damping force.

[0255] In some embodiments, the first determining unit is further configured to: determine a first region based on the target relative velocity range and a first trajectory of the first damping force changing with the at least two target relative velocities; determine a second region based on the target relative velocity range and a second trajectory of the current set of second damping forces changing with the at least two target relative velocities; 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 velocity range, and the second area represents the second vibration attenuation power corresponding to the second damping force within the target relative velocity range.

[0256] In some embodiments, the second constraint includes: the slope of the line connecting the points corresponding to every two adjacent target relative velocities on the second trajectory satisfies the target slope condition; the target slope condition indicates that when the target relative velocity is less than 0, the value of the second damping force corresponding to the target relative velocity is less than the value of the corresponding first damping force; and when the target relative velocity is greater than 0, the value of the second damping force corresponding to the target relative velocity is greater than the value of the corresponding first damping force.

[0257] For the dynamic model of vehicle vibration, it is assumed that the front and rear suspensions are approximately decoupled, i.e., the suspension mass distribution coefficient is... After decoupling the Z-axis vibration of the front and rear suspensions, the free vibration equation of the single-degree-of-freedom system can be found in formula (15):

[0258] (15);

[0259] in, For the damping ratio, It is the natural frequency when the damping is 0 (the periodic vibration frequency of a vibrating system when it is in free vibration, which is determined only by the internal mass distribution and elastic properties). This is the initial displacement. The initial velocity, For vibration time, The displacement is the result of free vibration.

[0260] Assumption The height value of a wave peak. After one cycle and The height values ​​of adjacent wave peaks, If the period of free vibration is..., then and The relationship can be seen in formula (16):

[0261] (16);

[0262] In this case, the logarithmic attenuation coefficient describes the degree of amplitude decay during free vibration. The determination method can be found in formula (17):

[0263] (17).

[0264] According to formula (17), the logarithmic attenuation coefficient increases with the increase of the damping ratio. This is because the damping ratio... With natural frequency It is inversely proportional; therefore, the smaller the natural frequency, the larger the logarithmic attenuation coefficient.

[0265] Assuming the sprung mass of the rear quarter of the vehicle is 1500 / 4 kg and the damping coefficient of the shock absorber is 2000 N∙s / m, for two free vibration systems with sprung frequencies of 1.2 Hz and 1.5 Hz, respectively, the initial velocity is zero, and the initial displacement is 12 mm and 15 mm, respectively. The smaller the sprung frequency, the smaller the suspension stiffness, and the smaller the first peak of displacement when going over a speed bump.

[0266] like Figure 8 As shown, the free vibration response (displacement response) of the single-degree-of-freedom system at spring deflection frequencies of 1.2Hz and 1.5Hz can be obtained from formula (15), that is, the free vibration response (displacement response) of the single-degree-of-freedom system at spring deflection frequencies of 1.2Hz and 1.5Hz respectively, i.e., the response in formula (15). .according to Figure 8 It can be concluded that for models with small on-spring deflection frequencies, although the free vibration period becomes longer, the decay is faster due to the small initial displacement value and large logarithmic decay coefficient.

[0267] This application provides a method for determining suspension parameters to better control the transient response of the vehicle body under speed bump conditions and to meet the engineering requirement of rapid decay of vehicle body vibration response. Figure 9 As shown, the suspension parameter determination method may include the following steps S21 to S24:

[0268] Step S21: Establish a dynamic model of the suspension system under speed bump conditions.

[0269] When implementing this, the process of establishing the dynamic model can be found in formula (1) of the above suspension parameter determination method.

[0270] Step S22: Based on the dynamic model, calculate the displacement time response of the seat guide rail under the speed bump condition.

[0271] In practice, the process of calculating the displacement time response of the seat guide rail under the speed bump condition based on the dynamic model can be found in formulas (2) to (7) in the above suspension parameter determination method.

[0272] Step S23: Establish the first optimization model and solve the sprung frequency and damping ratio of the front and rear suspensions based on the displacement time response of the seat guide rail under the speed bump condition.

[0273] When implementing the process, the first optimization model is established. The process of solving the sprung frequency and damping ratio of the front and rear suspensions based on the displacement time response of the seat guide rail under the speed bump condition can be found in formulas (8) to (12) in the suspension parameter determination method above.

[0274] Step S24: Establish the second optimization model and solve the nonlinear damping curve of the suspension damper based on the sprung frequency and damping ratio of the front and rear suspensions.

[0275] Here, the suspension damper can be referred to as the damping component in the suspension parameter determination method described above, and the nonlinear damping curve can be referred to as the curve corresponding to the second trajectory in the suspension parameter determination method described above.

[0276] In practice, the process of establishing a second optimization model and solving the nonlinear damping curve of the suspension damper based on the sprung frequency and damping ratio of the front and rear suspensions can be found in formulas (13) to (14) in the above suspension parameter determination method.

[0277] In this embodiment, by establishing a dynamic model of the suspension system under speed bump conditions and a first optimization model, a set of corresponding sprung frequencies and damping ratios of the front and rear suspensions are obtained. This reduces rear seat vibration and vehicle pitch vibration under speed bump conditions, rapidly attenuating the vibration of the front and rear suspensions so that both stop vibrating approximately simultaneously. Furthermore, a second optimization model is established, based on the sprung frequencies and damping ratios of the front and rear suspensions, to obtain the nonlinear damping curves of the suspension dampers. This reduces the impact of the suspension on the sprung surface under speed bump conditions, while simultaneously converting the damping force from linear to nonlinear, making the vibration attenuation power approximately equal before and after. This improves the control effect on the transient response of the vehicle body under speed bump conditions while rapidly attenuating the vibration response of the vehicle body, balancing vehicle comfort and handling, and providing users with a better driving experience.

[0278] For example, combined Figure 2 as well as Figure 3 With the relevant parameters as follows: , , , , , , , , , , , , , , In this case, by combining the parameters with the first optimization model described above, the optimal solution for the spring-loaded deflection frequency can be obtained as follows: , , , .

[0279] Compared to the other two options, Option 1: , , , Option 2: , , , The Z-axis displacement of the front seat rail, the Z-axis displacement of the rear seat rail, and the pitch angle displacement of the vehicle body are respectively as follows: Figure 10 , Figure 11 , Figure 12 As shown. Comparing the amplitude and convergence time, the optimized scheme in this application is superior to Schemes 1 and 2, with a lower displacement amplitude and a faster convergence time.

[0280] For example, taking the shock absorber of the rear suspension as an example, the linear damping coefficient obtained through optimization is 1541.9 N∙s / m. According to the second optimization model obtained by formula (13), the linear damping is nonlinearly transformed to obtain the optimal damping force curve, as shown in the figure. Figure 13 As shown, in the correspondence between the two damping forces and relative velocity, the optimized nonlinear damping can be represented by the above-mentioned optimal damping force curve.

[0281] Therefore, the suspension parameter determination method provided in this application embodiment can better suppress the first peak value of the front and rear seat displacement when the vehicle passes over a speed bump, while also enabling the vibration of the vehicle body to decay rapidly. It can also convert linear damping into nonlinear damping, further reducing the feeling of lifting, while ensuring that the vibration decay power remains unchanged.

[0282] This application also proposes a parameter adjustment method, such as... Figure 14 As shown, the parameter adjustment method includes the following steps S31 to S33:

[0283] Step S31: In response to the presence of a target speed bump within a target distance along the vehicle's driving direction, obtain the displacement time response of the vehicle's body in the target direction under the speed bump condition; the speed bump condition indicates that the vehicle travels through the target speed bump, and the target direction is perpendicular to the ground.

[0284] Here, the target distance can be a preset maximum distance at which the suspension parameters of the suspension system need to be adjusted. If the target speed bump exists within the target distance along the vehicle's direction of travel, it means that the vehicle will pass the target speed bump if it continues to travel in the current direction of travel.

[0285] In some implementations, radar data, image data, etc., can be used to determine whether there is a target speed bump within the target distance along the vehicle's direction of travel.

[0286] For example, while the vehicle is in motion, images of the environment around the vehicle can be captured by the image acquisition components on the vehicle, 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 direction of travel.

[0287] For example, while the vehicle is in motion, a three-dimensional map of the vehicle's location can be obtained through the radar components of the vehicle-mounted or roadside system, and based on the three-dimensional map, it can be determined whether there is a target speed bump within the target distance along the vehicle's direction of travel.

[0288] In some implementations, the displacement-time response is determined based on the displacement and velocity excitations of the vehicle's wheels by the target speed bump, as well as the dynamic model of the vehicle's suspension system, with the displacement and velocity excitations determined based on the dimensional parameters of the target speed bump.

[0289] Step S32: Determine a set of target suspension parameters for the suspension system with the goal of minimizing the first target parameter; the first target parameter is determined based on the displacement-time response and the 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 the target sprung frequency and the target damping ratio.

[0290] Step S33: Adjust the current suspension parameters of the suspension system to the target suspension parameters.

[0291] 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 over the target speed bump. This allows the suspension system to perform vibration control based on the target suspension parameters that minimize the vehicle's vibration response under speed bump conditions when the vehicle passes over the target speed bump.

[0292] In this embodiment, in response to the presence of a target speed bump within a target distance along the vehicle's driving direction, the displacement-time response of the vehicle body in the target direction under speed bump conditions is obtained. Based on the displacement-time response and suspension parameters, a first set of target parameters is constructed. With the goal of minimizing these first target parameters, a set of optimal target suspension parameters is determined. The current suspension parameters of the suspension system are then adjusted to these target suspension parameters. Thus, by considering the displacement-time response of the vehicle body in the target direction under speed bump conditions and optimizing the first target parameters, a set of corresponding target sprung frequency and target damping ratio can be obtained as target suspension parameters. Furthermore, by utilizing the vehicle's suspension system based on this set of target suspension parameters, the vibration response of the vehicle under speed bump conditions can be minimized, improving the effect of suppressing vehicle vibration under speed bump conditions, reducing the possibility of severe oscillations and large jumps, thereby improving vehicle controllability and comfort.

[0293] This application also proposes a parameter adjustment device, such as... Figure 15 As shown, the parameter adjustment device 1500 includes:

[0294] The second acquisition unit 1510 is configured to: in response to the presence of a target speed bump at a target distance along the vehicle's driving direction, acquire the displacement time response of the vehicle's body in the target direction under the speed bump condition; the speed bump condition indicates that the vehicle travels through the target speed bump, and the target direction is perpendicular to the ground.

[0295] The second determining unit 1520 is used to determine a set of target suspension parameters of the suspension system with the goal of minimizing the first target parameter; the first target parameter is determined based on the displacement-time response and the suspension parameters of the suspension system, and the first target parameter at least characterizes the vibration response of the vehicle in the target direction under the speed bump condition, and the target suspension parameters include the target sprung frequency and the target damping ratio;

[0296] The adjustment unit 1530 is used to adjust the current suspension parameters of the suspension system to the target suspension parameters.

[0297] In some implementations, the displacement-time response is determined based on the displacement and velocity excitations of the vehicle's wheels by the target speed bump, and a dynamic model of the vehicle's suspension system, wherein the displacement and velocity excitations are determined based on the dimensional parameters of the target speed bump.

[0298] This application provides an electronic device, including a memory and a processor. For example... Figure 16 As shown, the electronic device 1600 includes:

[0299] Memory 1610 is used to store computer programs that can run on processor 1620;

[0300] Processor 1620 is used to execute the program stored in memory 1610 to implement the above method.

[0301] This application also proposes a computer program including computer-readable code, which, when run in a computer device, enables a processor in the computer device to perform some or all of the steps in the above-described method.

[0302] This application provides a computer program product, including a computer program or instructions, which, when executed by a processor, implement some or all of the steps in the above-described method.

[0303] This application provides a computer-readable storage medium storing a computer program that can be executed by a processor to implement the above-described method.

[0304] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus, and devices according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0305] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0306] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0307] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

[0308] The descriptions of the above device embodiments are similar to those of the above method embodiments, and have similar beneficial effects. For technical details not disclosed in the device embodiments of this application, please refer to the descriptions of the method embodiments of this application for understanding.

[0309] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above-described processes do not imply a sequential 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 this application. The sequence numbers of the above-described embodiments are merely descriptive and do not represent the superiority or inferiority of the embodiments.

[0310] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0311] 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 illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0312] The units described above as separate components may or may not be physically separate. The components shown 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 to achieve the purpose of the embodiments of this application, depending on actual needs.

[0313] In addition, each functional unit in the various embodiments of this 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 integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0314] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as mobile storage devices, read-only memory (ROM), magnetic disks, or optical disks.

[0315] Alternatively, if the integrated units described above are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, or the parts that contribute to related technologies, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0316] The above embodiments are merely exemplary embodiments provided to fully illustrate this application, and the scope of protection of this application is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on this application are all within the scope of protection of this application.

Claims

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

2. The suspension parameter determination method according to claim 1, characterized in that, 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. 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 it 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.

3. The method for determining suspension parameters according to claim 2, characterized in that, The suspension parameters include sprung frequency and damping ratio; determining a set of target suspension parameters for the suspension system with the goal of minimizing the first target parameter includes: Obtain multiple sets of sprung frequencies and damping ratios that satisfy the first constraint condition; For each set of sprung frequency and damping ratio, determine the first target parameter corresponding to the current set of sprung frequency and damping ratio; The target spring-loaded frequency and the target damping ratio are determined as the smallest of the first target parameters in each group of spring-loaded frequency and damping ratio. The target suspension parameters are determined based on the target sprung frequency and the target damping ratio.

4. The method for determining suspension parameters according to claim 3, characterized in that, Determining the first target parameters corresponding to the current set of the sprung frequencies and the damping ratio includes: Based on the current set of sprung frequencies and damping ratios, 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 are determined for the speed bump condition. The first sub-target parameter includes the first peak value of the first displacement; the second sub-target parameter includes the absolute value of the difference between the second valley value and the third peak value of the first displacement after the second peak value; the third sub-target parameter includes the first peak value of the second displacement; the fourth sub-target parameter includes the absolute value of the difference between the second valley value and the third peak value of the second displacement after the second peak value; and the fifth sub-target parameter includes the maximum value of the absolute value of the difference between the height of the upper limit position of the front suspension and the height of the upper limit position of the 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 the current set of first target parameters corresponding to the spring-loaded frequency and the damping ratio.

5. The method for determining suspension parameters according to claim 4, characterized in that, The first constraint includes at least one of the following: The sprung frequency is greater than a first sprung frequency threshold and less than a second sprung frequency threshold; the sprung frequency includes the sprung frequency of the front suspension and the sprung frequency 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 the damping ratio of the front suspension and the damping ratio of the rear suspension; The sprung frequency of the front suspension is greater than that of the rear suspension; The sprung frequency of the front suspension is greater than the product of the sprung frequency of the rear suspension and a first coefficient, and less than the product of the sprung frequency 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 vehicle's pitch frequency is less than the rotation 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.

6. The method for determining suspension parameters according to any one of claims 1 to 5, characterized in that, The suspension system includes a damping component, and the method for determining the suspension parameters further includes: Obtain multiple sets of second damping forces that satisfy the second constraint conditions and correspond to at least two target relative velocities respectively; the target relative velocities are the relative velocities at both ends of the vibration damping component; For each group of second damping forces corresponding to at least two target relative velocities, a second target parameter corresponding to the current group of second damping forces is determined; 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 velocity at both ends of the vibration damping component; The smallest second target parameter among the second damping forces in each group is determined as the target damping force corresponding to the relative velocities of the vibration damping component and at least two targets, respectively; when the relative velocity at both ends of the vibration damping component is less than 0, the value of the target damping force corresponding to the relative velocity is less than the value of the corresponding first damping force; when the relative velocity at both ends of the vibration damping component is greater than 0, the value of the target damping force corresponding to the relative velocity is greater than the value of the corresponding first damping force.

7. The method for determining suspension parameters according to claim 6, characterized in that, Determining the second target parameters corresponding to the current set of second damping forces includes: Based on the target relative velocity range and the first trajectory of the first damping force changing with the relative velocities of the at least two targets, a first region is determined; Based on the target relative velocity range and the second trajectory of the current set of second damping forces as the relative velocities of the at least two targets change, a second region is determined; 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 second damping forces; the first area represents the first vibration attenuation power corresponding to the first damping force in the target relative velocity range, and the second area represents the second vibration attenuation power corresponding to the second damping force in the target relative velocity range.

8. The method for determining suspension parameters according to claim 7, characterized in that, The second constraint includes: The slope of the line connecting the points corresponding to any two adjacent relative velocities of the at least two targets on the second trajectory satisfies the target slope condition; the target slope condition indicates that when the relative target velocity is less than 0, the value of the second damping force corresponding to the relative target velocity is less than the value of the corresponding first damping force; and when the relative target velocity is greater than 0, the value of the second damping force corresponding to the relative target velocity is greater than the value of the corresponding first damping force.

9. A parameter adjustment method, characterized in that, include: In response to the presence of a target speed bump within a target distance along the vehicle's driving direction, the displacement time response of the vehicle's body in the target direction under the speed bump condition is obtained; The speed bump condition characterizes the vehicle driving over the target speed bump, the target direction being perpendicular to the ground, and the displacement-time response being determined based on the displacement excitation and velocity excitation of the vehicle's wheels by the target speed bump, as well as the 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. With the goal of minimizing a first target parameter, a set of target suspension parameters for the suspension system are determined; the first target parameter is determined based on the displacement-time response and the suspension parameters of the suspension system, and the first target parameter at least characterizes the vibration response of the vehicle in the target direction under the speed bump condition, and the target suspension parameters include the target sprung frequency and the target damping ratio; The current suspension parameters of the suspension system are adjusted to the target suspension parameters.

10. A suspension parameter determining device, characterized in that, The suspension parameter determination device includes: The first acquisition unit is used to: acquire the displacement time response of the vehicle body in the target direction under the speed bump condition; the speed bump condition represents the vehicle driving through the target speed bump, the target direction is perpendicular to the ground, and the displacement time response is determined based on the displacement excitation and velocity excitation of the vehicle's wheels by the target speed bump, as well as the dynamic model of the vehicle's suspension system, and the displacement excitation and velocity excitation are determined based on the size parameters of the target speed bump; The first determining 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 the displacement-time response and the suspension parameters of the suspension system, and the first target parameter at least characterizes the vibration response of the vehicle in the target direction under the speed bump condition, and the target suspension parameters include the target sprung frequency and the target damping ratio.

11. A parameter adjustment device, characterized in that, The parameter adjustment device includes: The second acquisition unit is used to acquire the displacement time response of the vehicle body in the target direction under the speed bump condition in response to the existence of a target speed bump at a target distance along the vehicle's driving direction; the speed bump condition indicates that the vehicle travels through the target speed bump, the target direction is perpendicular to the ground, and the displacement time response is determined based on the displacement excitation and velocity excitation of the vehicle's wheels by the target speed bump, as well as the dynamic model of the vehicle's suspension system, and the displacement excitation and velocity excitation are determined based on the size parameters of the target speed bump; The second determining unit is used to determine a set of target suspension parameters of the suspension system with the goal of minimizing the first target parameter; the first target parameter is determined based on the displacement-time response and the suspension parameters of the suspension system, and the first target parameter at least characterizes the vibration response of the vehicle in the target direction under the speed bump condition, and the target suspension parameters include the target sprung frequency and the target damping ratio; An adjustment unit is used to adjust the current suspension parameters of the suspension system to the target suspension parameters.

12. An electronic device, characterized in that, It includes a processor and a memory, the memory storing a computer program that can run on the processor, the processor executing the computer program to implement the steps of the method according to any one of claims 1 to 9.

13. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the steps of the method described in any one of claims 1 to 9.

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

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