阅读说明：本技术 一种基于车身姿态调节的阻尼可调悬架的控制方法 (Control method of damping-adjustable suspension based on vehicle body posture adjustment ) 是由 苗为为 蒋永峰 王仕伟 郑文博 于 2020-06-22 设计创作，主要内容包括：本发明涉及车辆减振领域,公开一种基于车身姿态调节的阻尼可调悬架的控制方法。悬架包括第一减振器、第二减振器、第三减振器和第四减振器,分别连接车身与左前车轮、右前车轮、左后车轮和右后车轮,该控制方法包括：S1、获取车身质心及车轮组件运动状态；S2、确定悬架的总目标阻尼力；S3、获取车身姿态；S4、确定各减振器的分目标阻尼力；S5、根据各减振器各自的分目标阻尼力,结合车身质心与车轮组件运动状态,计算各减振器的目标阻尼系数；S6、根据各减振器各自的阻尼系数调节范围,得到各减振器的实际目标阻尼系数。本发明能有效控制车身姿态平稳,以使车辆行驶于颠簸路面时车身竖向、纵倾及侧倾最小化,乘车舒适。(The invention relates to the field of vehicle vibration reduction, and discloses a control method of a damping-adjustable suspension based on vehicle body posture adjustment. The suspension comprises a first shock absorber, a second shock absorber, a third shock absorber and a fourth shock absorber which are respectively connected with a vehicle body and a left front wheel, a right front wheel, a left rear wheel and a right rear wheel, and the control method comprises the following steps: s1, acquiring the mass center of the vehicle body and the motion state of the wheel assembly; s2, determining the total target damping force of the suspension; s3, acquiring the posture of the vehicle body; s4, determining the target damping force of each shock absorber; s5, calculating target damping coefficients of the shock absorbers according to the respective target damping forces of the shock absorbers by combining the mass center of the vehicle body and the motion state of the wheel assembly; and S6, obtaining the actual target damping coefficient of each shock absorber according to the damping coefficient adjusting range of each shock absorber. The invention can effectively control the posture of the vehicle body to be stable, so that the vertical direction, the longitudinal inclination and the lateral inclination of the vehicle body are minimized when the vehicle runs on a bumpy road, and the riding is comfortable.)

1. A control method of a damping adjustable suspension based on vehicle body posture adjustment is characterized in that the suspension comprises a first shock absorber, a second shock absorber, a third shock absorber and a fourth shock absorber, the first shock absorber is connected with a vehicle body and a left front wheel, the second shock absorber is connected with the vehicle body and a right front wheel, the third shock absorber is connected with the vehicle body and a left rear wheel, and the fourth shock absorber is connected with the vehicle body and a right rear wheel, and the control method comprises the following steps:

s1, acquiring the mass center of the vehicle body and the motion state of a wheel assembly, wherein the wheel assembly comprises a left front wheel, a right front wheel, a left rear wheel and a right rear wheel;

s2, determining the total target damping force of the suspension according to the relative motion trend of the mass center of the vehicle body and the wheel assembly in the vertical direction of the vehicle body and by combining the absolute motion direction of the mass center of the vehicle body in the vertical direction of the vehicle body, wherein the total target damping force is the total damping force of the suspension when the vertical displacement of the vehicle body is zero;

s3, acquiring the posture of the vehicle body, wherein the posture of the vehicle body comprises the pitching and rolling states of the vehicle body;

s4, determining the respective sub-target damping forces of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber according to the total target damping force and the vehicle body posture;

s5, calculating target damping coefficients of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber according to the target damping forces of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber and in combination with the relative motion state of the mass center of the vehicle body and the wheel assembly;

and S6, obtaining the actual target damping coefficients of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber according to the target damping coefficients of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber and by combining the damping coefficient adjusting ranges of the shock absorbers.

2. The control method of a damping adjustable suspension based on vehicle body attitude adjustment according to claim 1, wherein step S2 includes:

if the mass center of the vehicle body and the wheel assembly are mutually far away from each other in the vertical direction of the vehicle body, and the absolute movement direction of the mass center of the vehicle body in the vertical direction of the vehicle body is upward, the total target damping force is a positive value; or the like, or, alternatively,

if the mass center of the vehicle body and the wheel assembly are mutually far away from each other in the vertical direction of the vehicle body, and the absolute motion direction of the mass center of the vehicle body in the vertical direction of the vehicle body is downward, the total target damping force is a negative value; or the like, or, alternatively,

if the mass center of the vehicle body and the wheel assembly are close to each other in the vertical direction of the vehicle body and the absolute motion direction of the mass center of the vehicle body in the vertical direction of the vehicle body is downward, the total target damping force is a positive value; or the like, or, alternatively,

if the mass center of the vehicle body and the wheel assembly are close to each other in the vertical direction of the vehicle body, and the absolute movement direction of the mass center of the vehicle body in the vertical direction of the vehicle body is upward, the total target damping force is a negative value.

3. The control method of a damping adjustable suspension based on vehicle body attitude adjustment according to claim 2, wherein the step S4 includes:

s4.1, determining initial target damping forces of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber according to the total target damping force and the front shaft equivalent spring load mass and the rear shaft equivalent spring load mass after the axle load transfer is considered;

and S4.2, respectively correcting the initial target damping forces of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber according to the vehicle body posture so as to determine the respective sub-target damping forces of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber.

4. The control method of the damping adjustable suspension based on the vehicle body posture adjustment as claimed in claim 3, wherein the step S4.1 comprises:

initial target damping force F of the first shock absorber_LF0Comprises the following steps:

initial target damping force F of the second shock absorber_RF0Comprises the following steps:

initial target damping force F of the third shock absorber_LR0Comprises the following steps:

initial target damping force F of fourth shock absorber_RR0Comprises the following steps:

wherein, F_TFor total target damping force, m_fTo account for the front axle equivalent sprung mass after axle load transfer, m_rTo account for the rear axle equivalent sprung mass after axle load transfer,

front axle equivalent spring load mass m_fComprises the following steps:

front axle equivalent spring load mass m_rComprises the following steps:

wherein m is_f0Is the front axle sprung mass m when the vehicle is stationary_r0Setting the joint between the vehicle body and the first shock absorber as a first position, the joint between the vehicle body and the second shock absorber as a second position, the joint between the vehicle body and the third shock absorber as a third position, the joint between the vehicle body and the fourth shock absorber as a fourth position, a_LFIs the vertical acceleration at the first position, a_RFIs the vertical acceleration at the second position, a_LRIs the vertical acceleration at the third position, a_RRIs the vertical acceleration at the fourth position.

5. The control method of the damping adjustable suspension based on the vehicle body posture adjustment as claimed in claim 4, wherein the step S4.2 comprises:

sub-target damping force F of first shock absorber_LFComprises the following steps:

F_LF＝F_LF0+(a_LF-a_RF)m_f

sub-target damping force F of second shock absorber_RFComprises the following steps:

F_RF＝F_RF0+(a_RF-a_LF)m_f

sub-target damping force F of third shock absorber_LRComprises the following steps:

F_LR＝F_LR0+(a_LR-a_RR)m_r

sub-target damping force F of fourth shock absorber_RRComprises the following steps:

F_RR＝F_RR0+(a_RR-a_LR)m_r。

6. the control method of a damping adjustable suspension based on vehicle body attitude adjustment according to claim 5, wherein the step S5 includes:

target damping coefficient C of first shock absorber_LFComprises the following steps:

target damping coefficient C of the second shock absorber_RFComprises the following steps:

target damping coefficient C of the third shock absorber_LRComprises the following steps:

target damping coefficient C of fourth shock absorber_RRComprises the following steps:

setting a vertical velocity at a first position to V₁₁Vertical velocity at the second position is V₂₁Vertical velocity at the third position is V₃₁Vertical velocity at the fourth position is V₄₁Vertical speed of the left front wheel is V₁₂Vertical velocity of front right wheel V₂₂Vertical speed of left rear wheel V₃₂Vertical velocity of right rear wheel V₄₂Wherein V is_LF＝(V₁₁-V₁₂)，V_RF＝(V₂₁-V₂₂)，V_LR＝(V₃₁-V₃₂)，V_RR＝(V₄₁-V₄₂)。

7. The control method of a damping adjustable suspension based on vehicle body attitude adjustment according to claim 6, wherein the step S6 includes:

setting the maximum limit damping coefficient of the first shock absorber to C₁₁Minimum ultimate damping coefficient of C₁₂；

If the target damping coefficient C of the first shock absorber_LFIf the value is negative, the actual target damping coefficient of the first shock absorber is adjusted to C₁₂；

If the target damping coefficient C of the first shock absorber_LFIs a positive value, and C_LF≥C₁₁Adjusting the actual target damping coefficient of the first shock absorber to C₁₁；

If the target damping coefficient C of the first shock absorber_LFIs a positive value, and C_LF＜C₁₁Adjusting the actual target damping coefficient of the first shock absorber to C_LF。

8. The control method of a damping adjustable suspension based on vehicle body attitude adjustment according to claim 6, wherein the step S6 further comprises:

setting the maximum limit damping coefficient of the second shock absorber to C₂₁Minimum ultimate damping coefficient of C₂₂；

If the target damping coefficient C of the second shock absorber_RFIf the value is negative, the actual target damping coefficient of the second shock absorber is adjusted to C₂₂；

If the target damping coefficient C of the second shock absorber_RFIs a positive value, and C_RF≥C₂₁Adjusting the actual target damping coefficient of the second shock absorber to C₂₁；

If the target damping coefficient C of the second shock absorber_RFIs a positive value, and C_RF＜C₂₁Adjusting the actual target damping coefficient of the second shock absorber to C_RF。

9. The control method of a damping adjustable suspension based on vehicle body attitude adjustment according to claim 6, wherein the step S6 further comprises:

setting the maximum limit damping coefficient of the third shock absorber to C₃₁Minimum ultimate damping coefficient of C₃₂；

If the target damping coefficient C of the third shock absorber_LRIf the value of the damping coefficient is negative, the actual target damping coefficient of the third shock absorber is adjusted to C₃₂；

If the target damping coefficient C of the third shock absorber_LRIs a positive value, and C_LR≥C₃₁Adjusting the actual target damping coefficient of the third shock absorber to C₃₁；

If the target damping coefficient C of the third shock absorber_LRIs a positive value, and C_LR＜C₃₁Adjusting the actual target damping coefficient of the third shock absorber to C_LR。

10. The control method of a damping adjustable suspension based on vehicle body attitude adjustment according to claim 6, wherein the step S6 further comprises:

setting the maximum limit damping coefficient of the fourth shock absorber to C₄₁Minimum ultimate damping coefficient of C₄₂；

If the target damping coefficient C of the fourth shock absorber_RRIf the damping coefficient is negative, the actual target damping coefficient of the fourth shock absorber is adjusted to C₄₂；

If the target damping coefficient C of the fourth shock absorber_RRIs a positive value, and C_RR≥C₄₁Adjusting the actual target damping coefficient of the fourth shock absorber to C₄₁；

If the target damping coefficient C of the fourth shock absorber_RRIs a positive value, and C_RR＜C₄₁Adjusting the actual target damping coefficient of the fourth shock absorber to C_RR。

Technical Field

The invention relates to the field of vehicle vibration reduction, in particular to a control method of a damping-adjustable suspension based on vehicle body posture adjustment.

Background

The suspension system is connected between the vehicle body and the tires and used for supporting the vehicle body, improving the vehicle body shaking phenomenon caused by the condition of high vehicle speed or bumpy road conditions and improving the riding comfort of a user.

In the existing partial suspension system, the damping coefficient of the shock absorber is adjustable, and the stability of a vehicle body is improved by controlling the damping coefficient of the shock absorber. However, the existing shock absorber damping control method has poor effect of improving the running stability of the vehicle body.

Disclosure of Invention

The invention aims to provide a control method of a damping-adjustable suspension based on vehicle body posture adjustment, which can effectively control the vehicle body stability when a vehicle runs on a bumpy road.

In order to realize the purpose, the following technical scheme is provided:

the control method of the damping adjustable suspension based on the vehicle body posture adjustment is provided, the suspension comprises a first shock absorber, a second shock absorber, a third shock absorber and a fourth shock absorber, the first shock absorber is connected with a vehicle body and a left front wheel, the second shock absorber is connected with the vehicle body and a right front wheel, the third shock absorber is connected with the vehicle body and a left rear wheel, and the fourth shock absorber is connected with the vehicle body and a right rear wheel, and the control method comprises the following steps:

s1, acquiring the mass center of the vehicle body and the motion state of a wheel assembly, wherein the wheel assembly comprises a left front wheel, a right front wheel, a left rear wheel and a right rear wheel;

s2, determining the total target damping force of the suspension according to the relative motion trend of the mass center of the vehicle body and the wheel assembly in the vertical direction of the vehicle body and by combining the absolute motion direction of the mass center of the vehicle body in the vertical direction of the vehicle body, wherein the total target damping force is the total damping force of the suspension when the vertical displacement of the vehicle body is zero;

s3, acquiring the posture of the vehicle body, wherein the posture of the vehicle body comprises the roll state and the roll state of the vehicle body;

s4, determining the respective sub-target damping forces of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber according to the total target damping force and the vehicle body posture;

s5, calculating target damping coefficients of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber according to the target damping forces of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber and in combination with the relative motion state of the mass center of the vehicle body and the wheel assembly;

and S6, obtaining the actual target damping coefficients of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber according to the target damping coefficients of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber and by combining the damping coefficient adjusting ranges of the shock absorbers.

As a preferable aspect of the control method of the damping adjustable suspension based on the vehicle body posture adjustment, the step S2 includes:

if the mass center of the vehicle body and the wheel assembly are mutually far away from each other in the vertical direction of the vehicle body, and the absolute movement direction of the mass center of the vehicle body in the vertical direction of the vehicle body is upward, the total target damping force is a positive value; or the like, or, alternatively,

if the mass center of the vehicle body and the wheel assembly are mutually far away from each other in the vertical direction of the vehicle body, and the absolute motion direction of the mass center of the vehicle body in the vertical direction of the vehicle body is downward, the total target damping force is a negative value; or the like, or, alternatively,

if the mass center of the vehicle body and the wheel assembly are close to each other in the vertical direction of the vehicle body and the absolute motion direction of the mass center of the vehicle body in the vertical direction of the vehicle body is downward, the total target damping force is a positive value; or the like, or, alternatively,

if the mass center of the vehicle body and the wheel assembly are close to each other in the vertical direction of the vehicle body, and the absolute movement direction of the mass center of the vehicle body in the vertical direction of the vehicle body is upward, the total target damping force is a negative value.

As a preferable aspect of the control method of the damping adjustable suspension based on the vehicle body posture adjustment, the step S4 includes:

s4.1, determining initial target damping forces of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber according to the total target damping force and the front shaft equivalent spring load mass and the rear shaft equivalent spring load mass after the axle load transfer is considered;

and S4.2, respectively correcting the initial target damping forces of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber according to the vehicle body posture so as to determine the respective sub-target damping forces of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber.

As a preferable scheme of the control method of the damping adjustable suspension based on the vehicle body posture adjustment, the step S4.1 includes:

initial target damping force F of the first shock absorber_LF0Comprises the following steps:

initial target damping force F of the second shock absorber_RF0Comprises the following steps:

initial target damping force F of the third shock absorber_LR0Comprises the following steps:

initial target damping force F of fourth shock absorber_RR0Comprises the following steps:

wherein, F_TFor total target damping force, m_fTo account for the front axle equivalent sprung mass after axle load transfer, m_rTo account for the rear axle equivalent sprung mass after axle load transfer,

front axle equivalent spring load mass m_fComprises the following steps:

front axle equivalent spring load mass m_rComprises the following steps:

wherein m is_f0Is the front axle sprung mass m when the vehicle is stationary_r0Setting the joint between the vehicle body and the first shock absorber as a first position, the joint between the vehicle body and the second shock absorber as a second position, the joint between the vehicle body and the third shock absorber as a third position, the joint between the vehicle body and the fourth shock absorber as a fourth position, a_LFIs the vertical acceleration at the first position, a_RFIs the vertical acceleration at the second position, a_LRIs the vertical acceleration at the third position, a_RRIs the vertical acceleration at the fourth position.

As a preferable scheme of the control method of the damping adjustable suspension based on the vehicle body posture adjustment, the step S4.2 includes:

sub-target damping force F of first shock absorber_LFComprises the following steps:

F_LF＝F_LF0+(a_LF-a_RF)m_f

sub-target damping force F of second shock absorber_RFComprises the following steps:

F_RF＝F_RF0+(a_RF-a_LF)m_f

sub-target damping force F of third shock absorber_LRComprises the following steps:

F_LR＝F_LR0+(a_LR-a_RR)m_r

sub-target damping force F of fourth shock absorber_RRComprises the following steps:

F_RR＝F_RR0+(a_RR-a_LR)m_r。

as a preferable aspect of the control method of the damping adjustable suspension based on the vehicle body posture adjustment, the step S5 includes:

target damping coefficient C of first shock absorber_LFComprises the following steps:

target damping coefficient C of the second shock absorber_RFComprises the following steps:

target damping coefficient C of the third shock absorber_LRComprises the following steps:

target damping coefficient C of fourth shock absorber_RRComprises the following steps:

setting a vertical velocity at a first position to V₁₁Vertical velocity at the second position is V₂₁Vertical velocity at the third position is V₃₁Vertical velocity at the fourth position is V₄₁Vertical speed of the left front wheel is V₁₂Vertical velocity of front right wheel V₂₂Vertical speed of left rear wheel V₃₂Vertical velocity of right rear wheel V₄₂Wherein V is_LF＝(V₁₁-V₁₂)，V_RF＝(V₂₁-V₂₂)，V_LR＝(V₃₁-V₃₂)，V_RR＝(V₄₁-V₄₂)。

As a preferable aspect of the control method of the damping adjustable suspension based on the vehicle body posture adjustment, the step S6 includes:

setting the maximum limit damping coefficient of the first shock absorber to C₁₁Minimum ultimate damping coefficient of C₁₂；

If the target damping coefficient C of the first shock absorber_LFIf the value is negative, the actual target damping coefficient of the first shock absorber is adjusted to C₁₂；

If the target damping coefficient C of the first shock absorber_LFIs a positive value, and C_LF≥C₁₁Then adjust it toAn actual target damping coefficient of the shock absorber is C₁₁；

If the target damping coefficient C of the first shock absorber_LFIs a positive value, and C_LF＜C₁₁Adjusting the actual target damping coefficient of the first shock absorber to C_LF。

As a preferable aspect of the control method of the damping adjustable suspension based on the vehicle body posture adjustment, the step S6 further includes:

setting the maximum limit damping coefficient of the second shock absorber to C₂₁Minimum ultimate damping coefficient of C₂₂；

If the target damping coefficient C of the second shock absorber_RFIf the value is negative, the actual target damping coefficient of the second shock absorber is adjusted to C₂₂；

If the target damping coefficient C of the second shock absorber_RFIs a positive value, and C_RF≥C₂₁Adjusting the actual target damping coefficient of the second shock absorber to C₂₁；

If the target damping coefficient C of the second shock absorber_RFIs a positive value, and C_RF＜C₂₁Adjusting the actual target damping coefficient of the second shock absorber to C_RF。

As a preferable aspect of the control method of the damping adjustable suspension based on the vehicle body posture adjustment, the step S6 further includes:

setting the maximum limit damping coefficient of the third shock absorber to C₃₁Minimum ultimate damping coefficient of C₃₂；

If the target damping coefficient C of the third shock absorber_LRIf the value of the damping coefficient is negative, the actual target damping coefficient of the third shock absorber is adjusted to C₃₂；

If the target damping coefficient C of the third shock absorber_LRIs a positive value, and C_LR≥C₃₁Adjusting the actual target damping coefficient of the third shock absorber to C₃₁；

If the target damping coefficient C of the third shock absorber_LRIs a positive value, and C_LR＜C₃₁Adjusting the actual target damping coefficient of the third shock absorber to C_LR。

As a preferable aspect of the control method of the damping adjustable suspension based on the vehicle body posture adjustment, the step S6 further includes:

setting the maximum limit damping coefficient of the fourth shock absorber to C₄₁Minimum ultimate damping coefficient of C₄₂；

If the target damping coefficient C of the fourth shock absorber_RRIf the damping coefficient is negative, the actual target damping coefficient of the fourth shock absorber is adjusted to C₄₂；

If the target damping coefficient C of the fourth shock absorber_RRIs a positive value, and C_RR≥C₄₁Adjusting the actual target damping coefficient of the fourth shock absorber to C₄₁；

If the target damping coefficient C of the fourth shock absorber_RRIs a positive value, and C_RR＜c₄₁Adjusting the actual target damping coefficient of the fourth shock absorber to C_RR。

The invention has the beneficial effects that:

according to the control method of the damping adjustable suspension based on the vehicle body posture adjustment, the motion states of the vehicle body and the wheel assembly are obtained in real time, the total target damping force of the shock absorber is obtained through calculation according to the relative motion trend of the vehicle body mass center and the wheel assembly in the vehicle body vertical direction, and meanwhile the positive and negative of the total target damping force are determined by combining the absolute motion direction of the vehicle body mass center in the vehicle body vertical direction. Meanwhile, the pitching and rolling states or the pitching and rolling trends of the vehicle body are measured, and the respective sub-target damping forces of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber are calculated by combining the total target damping force. Further, respective target damping coefficients of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber are calculated, and the target damping coefficients of the shock absorbers are compared with the damping coefficient adjustment ranges of the shock absorbers to obtain actual target damping coefficients of the shock absorbers. The posture of the vehicle body is controlled to be stable, so that the pitching and rolling motions of the vehicle body are minimized when the vehicle runs on a bumpy road, and the fatigue and the uncomfortable feeling of a driver and passengers are reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present invention and the drawings without creative efforts.

FIG. 1 is a schematic view of a suspension and a vehicle body according to an embodiment of the present invention;

fig. 2 is a first flowchart of a control method of a damping adjustable suspension based on vehicle body attitude adjustment according to an embodiment of the present invention;

fig. 3 is a second flowchart of a control method of a damping-adjustable suspension based on vehicle body attitude adjustment according to an embodiment of the present invention.

Reference numerals:

100-a vehicle body; 101-body centroid;

1-a first shock absorber; 2-a second shock absorber; 3-a third shock absorber; 4-fourth vibration damper.

Detailed Description

In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection or a removable connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The embodiment provides a control method of a damping adjustable suspension based on vehicle body posture adjustment, which can reduce fatigue and discomfort of a driver and passengers. As shown in fig. 1, the suspension includes a first shock absorber 1, a second shock absorber 2, a third shock absorber 3, and a fourth shock absorber 4, the first shock absorber 1 connects a vehicle body 100 and a left front wheel, the second shock absorber 2 connects the vehicle body 100 and a right front wheel, the third shock absorber 3 connects the vehicle body 100 and a left rear wheel, and the fourth shock absorber 4 connects the vehicle body 100 and a right rear wheel, and by controlling damping coefficients of the four shock absorbers respectively, the pitching and rolling movements of the vehicle body 100 when the vehicle runs on a bumpy road surface are minimized, so that fatigue and discomfort of a driver and passengers are reduced.

Specifically, as shown in fig. 1 and fig. 2, the method for controlling the damping adjustable suspension based on the vehicle body posture adjustment comprises the following steps:

and S1, acquiring the motion states of the vehicle body mass center 101 and the wheel assembly, wherein the wheel assembly comprises a left front wheel, a right front wheel, a left rear wheel and a right rear wheel.

Multiple sensors or other measuring elements may be used to measure the motion of the body center of mass 101 and each wheel, respectively. It should be noted that the motion state of the body centroid 101 and each wheel in the present embodiment mainly refers to the motion state of the body centroid 101 and each wheel in the body vertical direction, such as the speed and the acceleration.

And S2, determining the total target damping force of the shock absorber according to the relative motion trend of the mass center 101 of the vehicle body and the wheel assembly in the vertical direction of the vehicle body and the absolute motion direction of the vehicle body in the vertical direction of the vehicle body, wherein the total target damping force is the total damping force of the suspension when the vertical displacement of the vehicle body is zero.

The vehicle control unit obtains the measurement data of each sensor, and calculates the total target damping force according to the vertical relative motion of the mass center 101 of the vehicle body and each wheel and by combining a preset program, so that the vertical motion of the vehicle body is zero, and the stability and riding comfort of the vehicle when the vehicle runs on a bumpy road are improved. The method and program for calculating the total target damping force are the prior art and are not described in detail.

And S3, acquiring the posture of the vehicle body, wherein the posture of the vehicle body comprises the pitching and rolling states of the vehicle body.

And S4, determining the respective sub-target damping forces of the first shock absorber 1, the second shock absorber 2, the third shock absorber 3 and the fourth shock absorber 4 according to the total target damping force and the vehicle body posture.

In the existing scheme for controlling the damping coefficient of the shock absorber, the control of the posture of the vehicle body is not considered, and the posture of the vehicle body is difficult to control well, so that the movement of the finally controlled vehicle body on a bumpy road surface is not expected, namely the control effect of the vehicle provided with the shock absorber with adjustable damping and the control effect of the vehicle provided with the shock absorber with non-adjustable damping on the posture of the vehicle body are not obviously different. The control method of the embodiment takes the posture adjustment of the vehicle body into consideration, and ensures that the vertical, pitching and rolling amplitudes of the vehicle body are small.

And S5, calculating target damping coefficients of the first shock absorber 1, the second shock absorber 2, the third shock absorber 3 and the fourth shock absorber 4 according to the target damping forces of the first shock absorber 1, the second shock absorber 2, the third shock absorber 3 and the fourth shock absorber 4 and the relative motion state of the vehicle body mass center and the wheel assembly.

And S6, obtaining the actual target damping coefficients of the first shock absorber 1, the second shock absorber 2, the third shock absorber 3 and the fourth shock absorber 4 according to the target damping coefficients of the first shock absorber 1, the second shock absorber 2, the third shock absorber 3 and the fourth shock absorber 4 and by combining the damping coefficient adjusting ranges of the shock absorbers.

Further, the step S2 includes:

if the vehicle body center of mass 101 and the wheel assembly are away from each other in the vehicle body vertical direction, and the absolute movement direction of the vehicle body center of mass 101 in the vehicle body vertical direction is upward, the total target damping force is a positive value.

Alternatively, if the vehicle body center of mass 101 and the wheel assembly are away from each other in the vehicle body vertical direction, and the absolute movement direction of the vehicle body center of mass 101 in the vehicle body vertical direction is downward, the total target damping force is a negative value.

Alternatively, if the vehicle body center of mass 101 and the wheel assembly are close to each other in the vehicle body vertical direction, and the absolute movement direction of the vehicle body center of mass 101 in the vehicle body vertical direction is downward, the total target damping force is a positive value.

Alternatively, if the vehicle body center of mass 101 and the wheel assembly are close to each other in the vehicle body vertical direction, and the absolute movement direction of the vehicle body center of mass 101 in the vehicle body vertical direction is upward, the total target damping force is a negative value.

Specifically, an increase in damping force always causes a decrease in the current tendency of the body centroid 101 to move relative to the wheel assembly. The present embodiment is based on a vehicle body as a reference, and the control target is to minimize the amplitude of pitching of the vehicle body.

For the situation that the vehicle body mass center 101 and the wheel assembly are far away from each other in the vehicle body vertical direction, and the absolute motion direction of the vehicle body mass center 101 in the vehicle body vertical direction is upward, theoretically, the total target damping force should be set to be a positive value, and the total target damping force is increased relative to the total damping force of the current suspension, so that the trend that the vehicle body and the wheel assembly are far away from each other currently is reduced, a downward damping force is given to the vehicle body, and the upward motion amplitude of the vehicle body is reduced or even is zero.

For the situation that the vehicle body mass center 101 and the wheel assembly are far away from each other in the vehicle body vertical direction, and the absolute motion direction of the vehicle body mass center 101 in the vehicle body vertical direction is downward, theoretically, the total target damping force is set to be reduced relative to the total damping force of the current suspension, the total target damping force is a negative value, and an upward damping force is given to the vehicle body, so that the current downward motion of the vehicle body is stopped.

For the situation that the vehicle body mass center 101 and the wheel assembly are close to each other in the vehicle body vertical direction and the absolute motion direction of the vehicle body mass center 101 in the vehicle body vertical direction is downward, theoretically, the total target damping force is set to be increased relative to the total damping force of the current suspension, the total target damping force is a positive value, the trend that the vehicle body and the wheel assembly are close to each other is reduced, and an upward damping force is given to the vehicle body, so that the current downward motion of the vehicle body is stopped.

For the situation that the vehicle body mass center 101 and the wheel assembly are close to each other in the vehicle body vertical direction, and the absolute movement direction of the vehicle body mass center 101 in the vehicle body vertical direction is upward, theoretically, the total target damping force should be set to be reduced relative to the total damping force of the current suspension, and the total target damping force should be a negative value, and a downward damping force is given to the vehicle body, so that the current upward movement of the vehicle body is stopped.

Further, as shown in fig. 3, the step S4 includes:

s4.1, determining initial target damping forces of the first shock absorber 1, the second shock absorber 2, the third shock absorber 3 and the fourth shock absorber 4 according to the total target damping force and the front shaft equivalent spring load mass and the rear shaft equivalent spring load mass after the axle load transfer is considered.

The distribution method of the initial target damping force of each of the four shock absorbers comprises the following steps:

initial target damping force F of the first shock absorber 1_LF0Comprises the following steps:

initial target damping force F of the second shock absorber 2_RF0Comprises the following steps:

initial target damping force F of the third shock absorber 3_LR0Comprises the following steps:

of fourth dampers 4Initial target damping force F_RR0Comprises the following steps:

wherein, F_TFor total target damping force, m_fTo account for the front axle equivalent sprung mass after axle load transfer, m_rTo account for the rear axle equivalent sprung mass after axle load transfer,

front axle equivalent spring load mass m_fComprises the following steps:

front axle equivalent spring load mass m_rComprises the following steps:

wherein m is_f0Is the front axle sprung mass m when the vehicle is stationary_r0Setting the joint between the vehicle body and the first shock absorber as a first position, the joint between the vehicle body and the second shock absorber as a second position, the joint between the vehicle body and the third shock absorber as a third position, the joint between the vehicle body and the fourth shock absorber as a fourth position, a_LFIs the vertical acceleration at the first position, a_RFIs the vertical acceleration at the second position, a_LRIs the vertical acceleration at the third position, a_RRIs the vertical acceleration at the fourth position.

That is, the front axle equivalent sprung mass when the vehicle is running is the sum of the front axle sprung mass when the vehicle is stationary and the front axle vertical acceleration due to the pitching of the vehicle body 100. The rear axle equivalent sprung mass when the vehicle is running is the sum of the rear axle sprung mass when the vehicle is stationary and the rear axle vertical acceleration due to the pitching of the vehicle body 100. In step S4.1, the total target damping force is distributed to the four shock absorbers according to the pitch attitude of the vehicle body 100, and the initial target damping force of each shock absorber is obtained. And S4.2, respectively correcting the initial target damping forces of the first shock absorber 1, the second shock absorber 2, the third shock absorber 3 and the fourth shock absorber 4 according to the vehicle body posture to determine the respective sub-target damping forces of the first shock absorber 1, the second shock absorber 2, the third shock absorber 3 and the fourth shock absorber 4.

The method for distributing the target-divided damping forces of the four shock absorbers comprises the following steps:

sub-target damping force F of the first shock absorber 1_LFComprises the following steps:

F_LF＝F_LF0+(a_LF-a_RF)m_f

sub-target damping force F of the second shock absorber 2_RFComprises the following steps:

F_RF＝F_RF0+(a_RF-a_LF)m_f

the sub-target damping force F of the third shock absorber 3_LRComprises the following steps:

F_LR＝F_LR0+(a_LR-a_RR)m_r

the sub-target damping force F of the fourth shock absorber 4_RRComprises the following steps:

F_RR＝F_RR0+(a_RR-a_LR)m_r。

in step S4.2, the initial target damping force of each shock absorber is corrected by further taking into account the roll attitude of the vehicle body 100, to obtain the sub-target damping force of each shock absorber.

Further, the step S5 includes:

the calculation method of the target damping coefficients of the four shock absorbers comprises the following steps:

target damping coefficient C of the first shock absorber 1_LFComprises the following steps:

target damping coefficient C of the second shock absorber 2_RFComprises the following steps:

target damping coefficient C of the third shock absorber 3_LRComprises the following steps:

target damping coefficient C of the fourth shock absorber 4_RRComprises the following steps:

wherein the vertical velocity at the first position is set to V₁₁Vertical velocity at the second position is V₂₁Vertical velocity at the third position is V₃₁Vertical velocity at the fourth position is V₄₁Vertical speed of the left front wheel is V₁₂Vertical velocity of front right wheel V₂₂Vertical speed of left rear wheel V₃₂Vertical velocity of right rear wheel V₄₂Wherein V is_LF＝(V₁₁-V₁₂)，V_RF＝(V₂₁-V₂₂)，V_LR＝(V₃₁-V₃₂)，V_RR＝(V₄₁-V₄₂)。

It should be noted that the calculated target damping coefficient of each shock absorber is not always within the damping coefficient adjustment range of the corresponding shock absorber.

Therefore, as shown in fig. 3, the step S6 includes:

for the first shock absorber 1, the maximum limit damping coefficient of the first shock absorber 1 is set to C₁₁Minimum ultimate damping coefficient of C₁₂. As can be seen from practice, C₁₁And C₁₂Are all positive values.

If the target damping coefficient C of the first shock absorber 1 is obtained by the above calculation_LFIf the value is negative, the vehicle control unit adjusts the actual target damping coefficient of the first shock absorber 1 to be C₁₂。

If the target damping coefficient C of the first shock absorber 1_LFIf the comparison result is positive, the vehicle controller further compares C_LFAnd C₁₁The size of (2).

If C_LF≥C₁₁Then the actual target damping coefficient of the first shock absorber 1 is adjusted to C₁₁. If C_LF＜C₁₁Then the actual target damping coefficient of the first shock absorber 1 is adjusted to C_LF。

Similarly, for the second shock absorber 2, the maximum limit damping coefficient of the second shock absorber 2 is set to C₂₁Minimum ultimate damping coefficient of C₂₂. As can be seen from practice, C₂₁And C₂₂Are all positive values.

If the target damping coefficient C of the second shock absorber 2 is obtained by the above calculation_RFIf the value is negative, the vehicle control unit adjusts the actual target damping coefficient of the second shock absorber 2 to be C₂₂。

If the target damping coefficient C of the second shock absorber 2_RFIf the comparison result is positive, the vehicle controller further compares C₂₁And C₂₂The size of (2).

If C_RF≥C₂₁Adjusting the actual target damping coefficient of the second shock absorber 2 to C₂₁. If C_RF＜C₂₁Adjusting the actual target damping coefficient of the second shock absorber 2 to C_RF。

Similarly, for the third shock absorber 3, the maximum limit damping coefficient of the third shock absorber 3 is set to C₃₁Minimum ultimate damping coefficient of C₃₂. As can be seen from practice, C₃₁And C₃₂Are all positive values.

If the target damping coefficient C of the third shock absorber 3_LRIf the value is negative, the vehicle controller adjusts the actual target damping coefficient of the third shock absorber 3 to be C₃₂。

If the target damping coefficient C of the third shock absorber 3_LRIf the comparison result is positive, the vehicle controller further compares C₃₁And C₃₂The size of (2). If C_LR≥C₃₁Then the actual target damping coefficient of the third shock absorber 3 is adjusted to C₃₁. If C_LR＜C₃₁Then the actual target damping coefficient of the third shock absorber 3 is adjusted to C_LR。

Similarly, for the fourth damper 4, letThe maximum limit damping coefficient of the fourth shock absorber 4 is determined as C₄₁Minimum ultimate damping coefficient of C₄₂. As can be seen from practice, C₄₁And C₄₂Are all positive values.

If the target damping coefficient C of the fourth shock absorber 4_RRIf the damping coefficient is negative, the whole vehicle controller adjusts the actual target damping coefficient of the fourth shock absorber 4 to be C₄₂。

If the target damping coefficient C of the fourth shock absorber 4_RRIf the comparison result is positive, the vehicle controller further compares C₄₁And C₄₂The size of (2).

If C_RR≥C₄₁Then the actual target damping coefficient of the fourth shock absorber 4 is adjusted to C₄₁. If C_RR＜C₄₁Then the actual target damping coefficient of the fourth shock absorber 4 is adjusted to C_RR。

In the control method of the damping adjustable suspension based on vehicle body posture adjustment provided by the embodiment, the motion states of the vehicle body and the wheel assembly are measured in real time by measuring elements such as a sensor, the total target damping force of the shock absorber is calculated according to the relative motion trend of the vehicle body mass center 101 and the wheel assembly in the vehicle body vertical direction, and the positive and negative of the total target damping force are determined by combining the absolute motion direction of the vehicle body mass center 101 in the vehicle body vertical direction. Meanwhile, the pitch and roll states or the pitch and roll tendencies of the vehicle body are measured, and the respective sub-target damping forces of the first shock absorber 1, the second shock absorber 2, the third shock absorber 3, and the fourth shock absorber 4 are calculated in combination with the total target damping force. Further, the respective target damping coefficients of the first shock absorber 1, the second shock absorber 2, the third shock absorber 3 and the fourth shock absorber 4 are calculated, and the target damping coefficients of the respective shock absorbers are compared with the respective damping coefficient adjustment ranges of the respective shock absorbers to obtain the actual target damping coefficients of the respective shock absorbers.

The control process is a dynamic real-time adjustment process, the sensors measure the motion states of the vehicle body and the wheel assemblies in real time, the vehicle control unit acquires data of the sensors in real time and adjusts the damping coefficients of the shock absorbers to corresponding actual target damping coefficients in real time to control the attitude of the vehicle body to be stable, so that the pitching and rolling motions of the vehicle body are minimized when the vehicle runs on a bumpy road surface, and the fatigue and the uncomfortable feeling of a driver and passengers are reduced.

It should be understood that the term "vehicle" or "vehicular" or other similar terms as used herein generally includes motor vehicles, such as passenger vehicles including sport utility vehicles, commercial vehicles including passenger cars and vans, and includes hybrid vehicles, electric vehicles, fuel cell vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles, where the hybrid vehicle is a vehicle having two or more power sources, such as both gasoline-powered and electric-powered vehicles.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.