WO2021259004A1

WO2021259004A1 - Vehicle body attitude adjustment-based method for controlling adjustable damping suspension

Info

Publication number: WO2021259004A1
Application number: PCT/CN2021/097203
Authority: WO
Inventors: 苗为为; 蒋永峰; 王仕伟; 郑文博; 禹真
Original assignee: 中国第一汽车股份有限公司
Priority date: 2020-06-22
Filing date: 2021-05-31
Publication date: 2021-12-30
Also published as: CN111703268A; CN111703268B

Abstract

A vehicle body attitude adjustment-based method for controlling an adjustable damping suspension. A suspension comprises a first shock absorber (1), a second shock absorber (2), a third shock absorber (3), and a fourth shock absorber (4) that are connected to a vehicle body (100) as well as to a left front wheel, a right front wheel, a left rear wheel, and a right rear wheel, respectively. The control method comprises: obtaining the center of mass (101) of the vehicle body and the motion states of wheel assemblies; determining the total target damping force of the suspension; obtaining the attitude of the vehicle body; determining a sub-target damping force of each shock absorber; calculating a target damping coefficient of each shock absorber according to the respective sub-target damping force of each shock absorber, the center of mass of the vehicle body, and the motion states of the wheel assemblies; and obtaining an actual target damping coefficient of each shock absorber according to the respective damping coefficient adjustment range of each shock absorber.

Description

Control method of adjustable damping suspension based on body attitude adjustment

This application claims the priority of the Chinese patent application whose application date is June 22, 2020 and the application number is 202010574683.7. The entire content of this application is incorporated into this application by reference.

Technical field

This application relates to the field of vehicle vibration reduction, for example, to a control method of an adjustable damping suspension based on body attitude adjustment.

Background technique

The suspension system is connected between the vehicle body and the tires, and is set to support the vehicle body, and improves the vehicle body shaking phenomenon caused by fast vehicle speed or bumpy road conditions, and improves the user's riding comfort.

In some existing suspension systems, the damping coefficient of the shock absorber is adjustable, and the stability of the vehicle body is improved by controlling the damping coefficient of the shock absorber. However, the existing shock absorber damping control method does not have a good effect on improving the running stability of the vehicle body.

Summary of the invention

The present application provides a control method of an adjustable damping suspension based on body attitude adjustment, which can effectively control the stability of the vehicle body when the vehicle is running on a bumpy road.

An embodiment provides a control method of an adjustable damping suspension based on body attitude adjustment, wherein the suspension includes a first shock absorber, a second shock absorber, a third shock absorber, and a fourth shock absorber. A shock absorber is connected to the body and the left front wheel, the second shock absorber is connected to the body and the right front wheel, the third shock absorber is connected to the body and the left rear wheel, and the fourth shock absorber is connected to the body and the right rear wheel. The control method includes :

Step 1: Obtain the center of mass of the body and the motion state of the wheel assembly; wherein the wheel assembly includes the left front wheel, the right front wheel, the left rear wheel and the right rear wheel;

Step 2: Determine the total target damping force of the suspension according to the relative movement trend of the body center and the wheel assembly in the vertical direction of the body, and the absolute direction of the body center of mass movement in the vertical direction of the body; where the total target damping force is the vertical direction of the body The total damping force of the suspension when the displacement is zero;

Step 3: Obtain the body posture; where the body posture includes the roll and roll state of the body;

Step 4: Determine the respective 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 body attitude;

Step 5: Calculate the first damping based on the respective sub-target damping forces of the first, second, third and fourth shock absorbers, and the relative motion state of the body's center of mass and the wheel assembly The target damping coefficients of each of the shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber;

Step 6: According to the respective target damping coefficients of the first shock absorber, the second shock absorber, the third shock absorber, and the fourth shock absorber, and the first shock absorber, the second shock absorber, and the third shock absorber The respective damping coefficient adjustment ranges of the fourth shock absorber and the fourth shock absorber obtain the actual target damping coefficients of the first shock absorber, the second shock absorber, the third shock absorber, and the fourth shock absorber.

Optionally, step 2 includes:

In response to the vehicle body center of mass and the wheel assembly being far away from each other in the vertical direction of the vehicle body, and the absolute movement direction of the vehicle body center of mass in the vertical direction of the vehicle body is upward, it is determined that the total target damping force is a positive value;

In response to the body center and the wheel assembly being far away from each other in the vertical direction of the body, and the absolute movement direction of the body center in the vertical direction of the body is downward, the total target damping force is determined to be a negative value;

In response to the vehicle body center of mass and the wheel assembly approaching each other in the vertical direction of the vehicle body, and the absolute movement direction of the vehicle body center of mass in the vertical direction of the vehicle body is downward, determining that the total target damping force is a positive value; and

In response to the vehicle body center of mass and the wheel assembly approaching each other in the vertical direction of the vehicle body, and the absolute movement direction of the vehicle body center of mass in the vertical direction of the vehicle body is upward, it is determined that the total target damping force is a negative value.

Optionally, step 4 includes:

Step 4.1. Determine the first shock absorber, second shock absorber, third shock absorber and The respective initial target damping force of the fourth shock absorber;

Step 4.2. Correct the respective 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 body attitude to determine the first shock absorber and the second shock absorber. The respective target damping forces of the shock absorber, the third shock absorber and the fourth shock absorber.

Optionally, step 4.1 includes: determining the respective initial target damping forces of the first shock absorber, the second shock absorber, the third shock absorber, and the fourth shock absorber by the following formula:

The initial target damping force F _LF0 of the first shock absorber is:

The initial target damping force F _RF0 of the second shock absorber is:

The initial target damping force F _LR0 of the third shock absorber is:

The initial target damping force F _RR0 of the fourth shock absorber is:

Among them, F _T is the total target damping force, m _f is the equivalent sprung mass of the front axle after the axle _{load transfer is considered, and m r} is the equivalent sprung mass of the rear axle after the axle load transfer is considered.

The equivalent sprung mass m _f of the front axle is:

The equivalent sprung mass m _r of the front axle is:

Among them, m _f0 is the sprung mass of the front axle when the vehicle is stationary, m _r0 is the sprung mass of the rear axle when the vehicle is stationary, and g is the acceleration due to gravity. Set the connection point on the vehicle body with the first shock absorber as the first position, the connection point on the vehicle body with the second shock absorber as the second position, and the connection point on the vehicle body with the third shock absorber as the third position, The connection between the vehicle body and the fourth shock absorber is the fourth position, a _LF is the vertical acceleration at the first position, a _RF is the vertical acceleration at the second position, and a _LR is the vertical acceleration at the third position. Acceleration, a _RR is the vertical acceleration at the fourth position.

Optionally, step 4.2 includes: determining the respective target damping forces of the first shock absorber, the second shock absorber, the third shock absorber, and the fourth shock absorber by the following formula:

The sub-target damping force F _LF of the first shock absorber is:

F _LF ＝F _LF0 +(a _LF -a _RF )m _f

The sub-target damping force F _RF of the second shock absorber is:

F _RF ＝F _RF0 +(a _RF -a _LF )m _f

The sub-target damping force F _LR of the third shock absorber is:

F _LR ＝F _LR0 +(a _LR -a _RR )m _r

The sub-target damping force F _RR of the fourth shock absorber is:

F _RR =F _RR0 +(a _RR -a _LR )m _r .

Optionally, step 5 includes: calculating the respective target damping coefficients of the first shock absorber, the second shock absorber, the third shock absorber, and the fourth shock absorber according to the following equation:

The target damping coefficient C _LF of the first shock absorber is:

The target damping coefficient C _RF of the second shock absorber is:

The target damping coefficient C _LR of the third shock absorber is:

The target damping coefficient C _RR of the fourth shock absorber is:

Set the vertical speed at the first position as V ₁₁ , the vertical speed at the second position as V ₂₁ , the vertical speed at the third position as V ₃₁ , and the vertical speed at the fourth position as V ₄₁ , The vertical speed of the left front wheel is V ₁₂ , the vertical speed of the right front wheel is V ₂₂ , the vertical speed of the left rear wheel is V ₃₂ , and the vertical speed of the right rear wheel is V ₄₂ , where V _LF =(V ₁₁ -V ₁₂ ), V _RF =(V ₂₁ -V ₂₂ ), V _LR =(V ₃₁ -V ₃₂ ), V _RR =(V ₄₁ -V ₄₂ ).

Optionally, step 6 includes:

Set the maximum limit damping coefficient of the first shock absorber to C ₁₁ , and the minimum limit damping coefficient to C ₁₂ ;

In response to the target damping coefficient C _LF of the first shock absorber being a negative value, adjusting the actual target damping coefficient of the first shock absorber to C ₁₂ ;

In response to the target damping coefficient C _LF of the first shock absorber being a positive value, and C _LF ≥ _{C 11} , adjust the actual target damping coefficient of the first shock absorber to C ₁₁ ;

In response to the target damping coefficient C _LF of the first shock absorber being a positive value, and C _LF <C ₁₁ , the actual target damping coefficient of the first shock absorber is adjusted to C _LF .

Optionally, step 6 also includes:

Set the maximum limit damping coefficient of the second shock absorber to C ₂₁ and the minimum limit damping coefficient to C ₂₂ ;

In response to the target damping coefficient C _RF of the second shock absorber being a negative value, adjusting the actual target damping coefficient of the second shock absorber to C ₂₂ ;

In response to the target damping coefficient C _RF of the second shock absorber being a positive value, and C _RF ≥ _{C 21} , adjust the actual target damping coefficient of the second shock absorber to C ₂₁ ;

In response to the target damping coefficient C _RF of the second shock absorber being a positive value, and C _RF <C ₂₁ , the actual target damping coefficient of the second shock absorber is adjusted to C _RF .

Optionally, step 6 also includes:

Set the maximum limit damping coefficient of the third shock absorber to C ₃₁ and the minimum limit damping coefficient to C ₃₂ ;

In response to the target damping coefficient C _LR of the third shock absorber being a negative value, adjusting the actual target damping coefficient of the third shock absorber to C ₃₂ ;

In response to the target damping coefficient C _LR of the third shock absorber being a positive value, and C _LR ≥ _{C 31} , adjust the actual target damping coefficient of the third shock absorber to C ₃₁ ;

In response to the target damping coefficient C _LR of the third shock absorber being a positive value, and C _LR <C ₃₁ , the actual target damping coefficient of the third shock absorber is adjusted to C _LR .

Optionally, step 6 also includes:

Set the maximum limit damping coefficient of the fourth shock absorber to C ₄₁ and the minimum limit damping coefficient to C ₄₂ ;

In response to the target damping coefficient C _RR of the fourth shock absorber being a negative value, adjust the actual target damping coefficient of the fourth shock absorber to C ₄₂ ;

In response to the target damping coefficient C _RR of the fourth shock absorber being a positive value, and C _RR ≥ _{C 41} , adjust the actual target damping coefficient of the fourth shock absorber to C ₄₁ ;

In response to the target damping coefficient C _RR of the fourth shock absorber being a positive value, and C _RR <C ₄₁ , the actual target damping coefficient of the fourth shock absorber is adjusted to C _RR .

Description of the drawings

Figure 1 is a schematic diagram of the connection between a suspension and a vehicle body provided by an embodiment of the application;

2 is a first flowchart of a method for controlling an adjustable damping suspension based on body attitude adjustment according to an embodiment of the application;

3 is a second flowchart of a control method of an adjustable damping suspension based on body attitude adjustment provided by an embodiment of the application.

Reference signs:

100-body; 101-body center of mass;

1- First shock absorber; 2- Second shock absorber; 3- Third shock absorber; 4- Fourth shock absorber.

detailed description

In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the application and simplifying the description, and does not indicate or imply that the pointed device or element must have a specific orientation or a specific orientation. The structure and operation cannot therefore be understood as a limitation of this application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above-mentioned terms in this application can be understood under specific circumstances.

This embodiment provides a method for controlling a damping adjustable suspension based on body attitude adjustment, which can reduce the fatigue and discomfort of the driver and the occupant. As shown in Figure 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 is connected to the vehicle body 100 and the left front wheel. , The second shock absorber 2 is connected to the body 100 and the right front wheel, the third shock absorber 3 is connected to the body 100 and the left rear wheel, and the fourth shock absorber 4 is connected to the body 100 and the right rear wheel. By controlling the four shock absorbers respectively The damping coefficient is to minimize the pitch and roll motion of the body 100 when the vehicle is driving on a bumpy road, so as to reduce the fatigue and discomfort of the driver and the occupant.

As shown in Figure 1 and Figure 2, the control method of the adjustable damping suspension based on body attitude adjustment includes steps S1 to S6:

S1. Obtain the body center of mass 101 and the motion state of the wheel assembly, where the wheel assembly includes 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 body mass center 101 and the motion state of each wheel respectively. The body center of mass 101 and the motion state of each wheel in this embodiment mainly refer to the motion state of the body center of mass 101 and each wheel in the vertical direction of the body, such as speed and acceleration.

S2. Determine the total target damping force of the shock absorber according to the relative movement trend of the body center 101 and the wheel assembly in the vertical direction of the body and the absolute direction of the body center 101 in the vertical direction of the body. The total damping force of the suspension when the vertical displacement is zero.

The vehicle controller obtains the measurement data of the above-mentioned multiple sensors, calculates the total target damping force according to the vertical relative movement of the body center of mass 101 and the wheel, and combines with a preset program to make the vertical movement of the body 100 zero , Improve the stability and ride comfort of the vehicle when driving on bumpy roads. Among them, the calculation method and calculation procedure of the total target damping force are related technologies, and the details are not repeated here.

S3. Acquire the body posture, where the body posture includes the pitch and roll state of the body 100.

S4. Determine the respective 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 body attitude.

In the existing solutions for controlling the damping coefficient of the shock absorber, the body attitude control is not considered, and it is difficult to control the body attitude well, so that the final controlled body movement on the bumpy road is not as expected, that is, the adjustable damping shock absorber is installed There is no obvious difference in the control effect of the vehicle body attitude between a vehicle and a vehicle equipped with a non-adjustable damping shock absorber. The control method of this embodiment takes into account the body attitude adjustment to ensure that the vertical and pitch and roll amplitudes of the body are small.

S5. Calculate based on the respective 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 body center of mass 101 and the wheel assembly 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, respectively.

S6. According to 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, and the first shock absorber 1, the second shock absorber 2 , The respective damping coefficient adjustment ranges of the third shock absorber 3 and the fourth shock absorber 4 to obtain the first shock absorber 1, the second shock absorber 2, the third shock absorber 3 and the fourth shock absorber 4 respectively The actual target damping coefficient.

Exemplarily, the foregoing step S2 includes:

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

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

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

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

Optionally, the increase in the damping force always causes the current relative movement trend of the body center of mass 101 and the wheel assembly to decrease. In this embodiment, the vehicle body 100 is used as a reference, and the control objective is to minimize the bumps of the vehicle body 100.

For the case where the body mass center 101 and the wheel assembly are far away from each other in the vertical direction of the body, and the absolute movement direction of the body mass center 101 in the vertical direction of the body is upward, theoretically, the total target damping force should be set to a positive value, and the total target damping force should be relatively The total damping force of the current suspension is increased to reduce the current tendency of the vehicle body 100 and the wheel assembly to move away from each other, and to give the vehicle body 100 a downward damping force, so that the upward movement amplitude of the vehicle body is reduced or even zero.

For the case where the body center of mass 101 and the wheel assembly are far away from each other in the vertical direction of the body, and the absolute direction of the body center of mass 101 in the vertical direction of the body is downward, theoretically, the total target damping force should be set relative to the total damping force of the current suspension Decrease, and the total target damping force is negative, give the body an upward damping force to stop the current downward movement of the body.

For the case where the body center of mass 101 and the wheel assembly are close to each other in the vertical direction of the body, and the absolute direction of motion of the body center of mass 101 in the vertical direction of the body is downward, theoretically, the total target damping force should be set relative to the total damping force of the current suspension Increase, and the total target damping force is a positive value, reducing the tendency of the vehicle body and the wheel assembly to approach each other, and giving the vehicle body an upward damping force to stop the current downward movement of the vehicle body.

For the case where the body center of mass 101 and the wheel assembly are close to each other in the vertical direction of the body, and the absolute direction of the body center of mass 101 in the vertical direction of the body is upward, theoretically, the total target damping force should be set relative to the total damping force reduction of the current suspension Small, and the total target damping force should be a negative value. Give the body a downward damping force to stop the current upward movement of the body.

As shown in Figure 3, the above step S4 includes steps S4.1 to S4.2:

S4.1. Determine the first shock absorber 1, the second shock absorber 2, and the third shock absorber according to the total target damping force, considering the equivalent sprung mass of the front axle and the equivalent sprung mass of the rear axle after axle load transfer The initial target damping force of the vibrator 3 and the fourth shock absorber 4 respectively.

The distribution method of the initial target damping force of each of the four shock absorbers is:

The initial target damping force F _LF0 of the first shock absorber 1 is:

The initial target damping force F _RF0 of the second shock absorber 2 is:

The initial target damping force F _LR0 of the third shock absorber 3 is:

The initial target damping force F _RR0 of the fourth shock absorber 4 is:

Among them, F _T is the total target damping force, m _f is the equivalent sprung mass of the front axle after considering the axle load transfer, and m _r is the equivalent sprung mass of the rear axle after considering the axle load transfer.

The equivalent sprung mass m _f of the front axle is:

The equivalent sprung mass m _r of the rear axle is:

Among them, m _f0 is the sprung mass of the front axle when the vehicle is stationary, m _r0 is the sprung mass of the rear axle when the vehicle is stationary, and g is the acceleration due to gravity. Set the connection point on the vehicle body 100 with the first shock absorber 1 as the first position, the connection point on the vehicle body 100 with the second shock absorber 2 as the second position, and the connection point on the vehicle body 100 with the third shock absorber 3 Is the third position, the connection point of the vehicle body 100 with the fourth shock absorber 4 is the fourth position, a _LF is the vertical acceleration at the first position, a _RF is the vertical acceleration at the second position, a _LR Is the vertical acceleration at the third position, and a _RR is the vertical acceleration at the fourth position.

That is, the equivalent sprung mass of the front axle when the vehicle is running is the sum of the sprung mass of the front axle when the vehicle is stationary and the equivalent additional mass brought about by the vertical acceleration of the front axle due to the pitch of the vehicle body 100. The equivalent sprung mass of the rear axle when the vehicle is running is the sum of the sprung mass of the rear axle when the vehicle is stationary and the vertical acceleration of the rear axle caused by the pitch of the body 100. In step S4.1, according to the pitch attitude of the vehicle body 100, the total target damping force is allocated to the four shock absorbers to obtain the initial target damping force of each shock absorber.

S4.2. Correct the respective 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 body attitude to determine the first shock absorber The respective target damping forces of the vibrator 1, the second shock absorber 2, the third shock absorber 3, and the fourth shock absorber 4.

The sub-target damping force of each of the four shock absorbers is calculated by the following formula:

The sub-target damping force F _LF of the first shock absorber 1 is:

F _LF ＝F _LF0 +(a _LF -a _RF )m _f

The sub-target damping force F _RF of the second shock absorber 2 is:

F _RF ＝F _RF0 +(a _RF -a _LF )m _f

The sub-target damping force F _LR of the third shock absorber 3 is:

F _LR ＝F _LR0 +(a _LR -a _RR )m _r

The sub-target damping force F _RR of the fourth shock absorber 4 is:

F _RR ＝F _RR0 +(a _RR -a _LR )m _r

In step S4.2, the roll attitude of the vehicle body 100 is taken into consideration to correct the initial target damping force of each shock absorber to obtain the sub-target damping force of each shock absorber.

Optionally, the foregoing step S5 includes:

Calculate the target damping coefficient of each of the four shock absorbers by the following formula:

The target damping coefficient C _LF of the first shock absorber 1 is:

The target damping coefficient C _RF of the second shock absorber 2 is:

The target damping coefficient C _LR of the third shock absorber 3 is:

The target damping coefficient C _RR of the fourth shock absorber 4 is:

Among them, set the vertical speed at the first position as V ₁₁ , the vertical speed at the second position as V ₂₁ , the vertical speed at the third position as V ₃₁ , and the vertical speed at the fourth position as V _41. The vertical speed of the left front wheel is V ₁₂ , the vertical speed of the right front wheel is V ₂₂ , the vertical speed of the left rear wheel is V ₃₂ , and the vertical speed of the right rear wheel is V ₄₂ , where V _LR =( V ₁₁ -V ₁₂ ), V _RF =(V ₂₁ -V ₂₂ ), V _LR =(V ₃₁ -V ₃₂ ), V _RR =(V ₄₁ -V ₄₂ ).

In an embodiment, the calculated target damping coefficient of each shock absorber is not always within the adjustment range of the damping coefficient of the corresponding shock absorber.

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

For the first shock absorber 1, set the maximum limit damping coefficient of the first shock absorber 1 to C ₁₁ and the minimum limit damping coefficient to C ₁₂ . It can be known from reality that both C ₁₁ and C ₁₂ are positive values.

If the calculated target damping coefficient C _LF of the first shock absorber 1 is a negative value, the vehicle controller adjusts the actual target damping coefficient of the first shock absorber 1 to C ₁₂ .

If the target damping coefficient C _LF of the first shock absorber 1 is a positive value, the vehicle controller compares the magnitude of _{C LF} and C _11.

If C _LF ≥ _{C 11} , the actual target damping coefficient of the first shock absorber 1 is adjusted to C ₁₁ . If C _LF <C ₁₁ , 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 C ₂₁ , and the minimum limit damping coefficient is C ₂₂ . It can be known from reality that both C ₂₁ and C ₂₂ are positive values.

If the calculated target damping coefficient C _RF of the second shock absorber 2 is a negative value, the vehicle controller adjusts the actual target damping coefficient of the second shock absorber 2 to C ₂₂ .

If the target damping coefficient C _RF of the second shock absorber 2 is a positive value, the vehicle controller compares the magnitudes of _{C 21} and C _22.

If C _RF ≥ _{C 21} , adjust the actual target damping coefficient of the second shock absorber 2 to C ₂₁ . If C _RF <C ₂₁ , adjust 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 C ₃₁ , and the minimum limit damping coefficient is C ₃₂ . It can be known from reality that both C ₃₁ and C ₃₂ are positive values.

If the target damping coefficient C _LR of the third shock absorber 3 is a negative value, the vehicle controller adjusts the actual target damping coefficient of the third shock absorber 3 to C ₃₂ .

If the target damping coefficient C _LR of the third shock absorber 3 is a positive value, the vehicle controller compares the magnitudes of _{C 31} and C _32. If C _LR ≥ _{C 31} , the actual target damping coefficient of the third shock absorber 3 is adjusted to C ₃₁ . If C _LR <C ₃₁ , the actual target damping coefficient of the third shock absorber 3 is adjusted to C _LR .

Similarly, for the fourth shock absorber 4, the maximum limit damping coefficient of the fourth shock absorber 4 is set to C ₄₁ , and the minimum limit damping coefficient is C ₄₂ . It can be known from reality that both C ₄₁ and C ₄₂ are positive values.

If the target damping coefficient C _RR of the fourth shock absorber 4 is a negative value, the vehicle controller adjusts the actual target damping coefficient of the fourth shock absorber 4 to C ₄₂ .

If the target damping coefficient C _RR of the fourth shock absorber 4 is a positive value, the vehicle controller compares the magnitudes of _{C 41} and C _42.

If C _RR ≥ _{C 41} , the actual target damping coefficient of the fourth shock absorber 4 is adjusted to C ₄₁ . If C _RR <C ₄₁ , the actual target damping coefficient of the fourth shock absorber 4 is adjusted to C _RR .

In the control method of an adjustable damping suspension based on body attitude adjustment provided by this embodiment, sensors and other measuring elements measure the motion state of the body 100 and the wheel assembly in real time, according to the relative movement trend of the body center 101 and the wheel assembly in the vertical direction of the body , The total target damping force of the shock absorber is calculated, and at the same time, the positive or negative of the total target damping force is determined by combining the absolute movement direction of the body center of mass 101 in the vertical direction of the vehicle body. At the same time, the trim and roll state or the trim and roll trend of the body 100 are measured, and the total target damping force is combined to calculate the first shock absorber 1, the second shock absorber 2, the third shock absorber 3, and the fourth shock absorber. The respective target damping force of the shock absorber 4. Further, calculate 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, and compare the target damping coefficient of each shock absorber with each The respective damping coefficient adjustment ranges of the vibrators are compared, and the actual target damping coefficient of each shock absorber is obtained.

The above control process is a dynamic real-time adjustment process. The sensors measure the motion state of the body 100 and wheel components in real time. The vehicle controller obtains sensor data in real time, and adjusts the damping coefficient of each shock absorber to the corresponding actual target damping coefficient in real time. The body posture is controlled to be stable, so as to minimize the pitch and roll movement of the body 100 when the vehicle is running on a bumpy road, and reduce the fatigue and discomfort of the driver and the occupant.

In the vehicle body attitude adjustment-based damping adjustable suspension control method provided by the present application, the motion state of the vehicle body 100 and the wheel assembly is obtained in real time, and the vibration reduction is calculated according to the relative movement trend of the body center of mass 101 and the wheel assembly in the vertical direction of the vehicle body The total target damping force of the vehicle body, and at the same time, the positive or negative of the total target damping force is determined according to the absolute movement direction of the body center of mass 101 in the vertical direction of the vehicle body. At the same time, the trim and roll state or the trim and roll trend of the body 100 are measured, and the total target damping force is combined to calculate the first shock absorber 1, the second shock absorber 2, the third shock absorber 3, and the fourth shock absorber. The respective target damping force of the shock absorber 4. Further, calculate 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, and compare the target damping coefficient of each shock absorber with the target damping coefficient of each shock absorber. The damping coefficient adjustment range of the vibrator is compared, and the actual target damping coefficient of each shock absorber is obtained. The posture of the vehicle body is controlled to be stable, so as to minimize the pitch and roll movement of the vehicle body 100 when the vehicle is running on a bumpy road, and reduce the fatigue and discomfort of the driver and the passengers.

It should be understood that the terms "vehicle" or "vehicle" or other similar terms used herein generally include motor vehicles, such as passenger vehicles including sports utility vehicles, and commercial vehicles including passenger cars and trucks. Vehicles, and include hybrid vehicles, electric vehicles, fuel cell vehicles, hydrogen-powered vehicles and other alternative fuel vehicles, among which hybrid vehicles are vehicles with two or more power sources, such as both gasoline-powered and electric-powered vehicle.

Claims

A control method of an adjustable damping suspension based on body attitude adjustment, wherein the suspension includes a first shock absorber, a second shock absorber, a third shock absorber, and a fourth shock absorber. The first shock absorber The vehicle body and the left front wheel are connected, the second shock absorber is connected to the vehicle body and the right front wheel, the third shock absorber is connected to the vehicle body and the left rear wheel, and the fourth shock absorber is connected to the vehicle body and the right rear wheel. The control method includes:

Step 1 (S1): Obtain the center of mass of the vehicle body and the motion state of the wheel assembly; wherein the wheel assembly includes the left front wheel, the right front wheel, the left rear wheel and the right rear wheel;

Step 2 (S2): Determine the total target damping force of the suspension according to the relative movement trend of the body center and the wheel assembly in the vertical direction of the body, and the absolute direction of the body center of mass movement in the vertical direction of the body; where the total target damping force is The total damping force of the suspension when the vertical displacement of the vehicle body is zero;

Step 3 (S3): Obtain the body posture; wherein the body posture includes the pitch and roll state of the body;

Step 4 (S4): Determine the respective 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 body attitude;

Step 5 (S5): According to the respective target damping forces of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber, and the relative motion state of the body center of mass and the wheel assembly, calculate the first 1. Target damping coefficients of the shock absorber, the second shock absorber, the third shock absorber, and the fourth shock absorber;

Step 6 (S6): According to the respective target damping coefficients of the first, second, third, and fourth shock absorbers, and the first shock absorber, the second shock absorber, and the The respective damping coefficient adjustment ranges of the three shock absorbers and the fourth shock absorber obtain the actual target damping coefficients of the first shock absorber, the second shock absorber, the third shock absorber, and the fourth shock absorber.
The control method of an adjustable damping suspension based on body attitude adjustment according to claim 1, wherein step 2 (S2) includes:

In response to the vehicle body center of mass and the wheel assembly being far away from each other in the vertical direction of the vehicle body, and the absolute movement direction of the vehicle body center of mass in the vertical direction of the vehicle body is upward, it is determined that the total target damping force is a positive value;

In response to the body center and the wheel assembly being far away from each other in the vertical direction of the body, and the absolute movement direction of the body center in the vertical direction of the body is downward, the total target damping force is determined to be a negative value;

In response to the vehicle body center of mass and the wheel assembly approaching each other in the vertical direction of the vehicle body, and the absolute movement direction of the vehicle body center of mass in the vertical direction of the vehicle body is downward, determining that the total target damping force is a positive value; and

In response to the vehicle body center of mass and the wheel assembly approaching each other in the vertical direction of the vehicle body, and the absolute movement direction of the vehicle body center of mass in the vertical direction of the vehicle body is upward, it is determined that the total target damping force is a negative value.
The control method of an adjustable damping suspension based on body attitude adjustment according to claim 2, wherein step 4 (S4) includes:

Step 4.1 (S4.1): Determine the first shock absorber, second shock absorber, and second shock absorber according to the total target damping force, the equivalent sprung mass of the front axle and the equivalent sprung mass of the rear axle after the axle load has been transferred The initial target damping force of the three shock absorbers and the fourth shock absorber;

Step 4.2 (S4.2): Correct the initial target damping force of the first shock absorber, the second shock absorber, the third shock absorber and the fourth shock absorber respectively according to the body attitude to determine the first shock absorber The respective target damping forces of the vibrator, the second damper, the third damper, and the fourth damper.
The control method of an adjustable damping suspension based on body attitude adjustment according to claim 3, wherein step 4.1 (S4.1) includes: determining the first shock absorber, the second shock absorber, and the second shock absorber by the following equations The initial target damping force of the three shock absorbers and the fourth shock absorber:

The initial target damping force F LF0 of the first shock absorber is:

The initial target damping force F RF0 of the second shock absorber is:

The initial target damping force F LR0 of the third shock absorber is:

The initial target damping force F RR0 of the fourth shock absorber is:

Among them, F T is the total target damping force, m f is the equivalent sprung mass of the front axle after the axle load transfer is considered, and m r is the equivalent sprung mass of the rear axle after the axle load transfer is considered.

The equivalent sprung mass m f of the front axle is:

The equivalent sprung mass m r of the rear axle is:

Among them, m f0 is the sprung mass of the front axle when the vehicle is stationary, m r0 is the sprung mass of the rear axle when the vehicle is stationary, and g is the acceleration due to gravity. Set the connection point on the vehicle body with the first shock absorber as the first position, the connection point on the vehicle body with the second shock absorber as the second position, and the connection point on the vehicle body with the third shock absorber as the third position, The connection between the vehicle body and the fourth shock absorber is the fourth position, a LF is the vertical acceleration at the first position, a RF is the vertical acceleration at the second position, and a LR is the vertical acceleration at the third position. Acceleration, a RR is the vertical acceleration at the fourth position.
The control method of an adjustable damping suspension based on body attitude adjustment according to claim 4, wherein step 4.2 (S4.2) comprises: determining the first shock absorber, the second shock absorber, and the second shock absorber by the following equations The sub-target damping forces of the three shock absorbers and the fourth shock absorber:

The sub-target damping force F LF of the first shock absorber is:

F LF ＝F LF0 +(a LF -a RF )m f

The sub-target damping force F RF of the second shock absorber is:

F RF ＝F RF0 +(a RF -a LF )m f

The sub-target damping force F LR of the third shock absorber is:

F LR ＝F LR0 +(a LR -a RR )m r

The sub-target damping force F RR of the fourth shock absorber is:

F RR =F RR0 +(a RR -a LR )m r .
The control method of an adjustable damping suspension based on body attitude adjustment according to claim 5, wherein step 5 (S5) comprises: calculating the first shock absorber, the second shock absorber, and the third shock absorber according to the following equations The respective target damping coefficients of the vibrator and the fourth shock absorber:

The target damping coefficient C LF of the first shock absorber is:

The target damping coefficient C RF of the second shock absorber is:

The target damping coefficient C LR of the third shock absorber is:

The target damping coefficient C RR of the fourth shock absorber is:

Set the vertical speed at the first position as V 11 , the vertical speed at the second position as V 21 , the vertical speed at the third position as V 31 , and the vertical speed at the fourth position as V 41 , The vertical speed of the left front wheel is V 12 , the vertical speed of the right front wheel is V 22 , the vertical speed of the left rear wheel is V 32 , and the vertical speed of the right rear wheel is V 42 , where V LF =(V 11 -V 12 ), V RF =(V 21 -V 22 ), V LR =(V 31 -V 32 ), V RR =(V 41 -V 42 ).
The control method of an adjustable damping suspension based on body attitude adjustment according to claim 6, wherein step 6 (S6) includes:

Set the maximum limit damping coefficient of the first shock absorber to C 11 , and the minimum limit damping coefficient to C 12 ;

In response to the target damping coefficient C LF of the first shock absorber being a negative value, adjusting the actual target damping coefficient of the first shock absorber to C 12 ;

In response to the target damping coefficient C LF of the first shock absorber being a positive value, and C LF ≥ C 11 , adjust the actual target damping coefficient of the first shock absorber to C 11 ;

In response to the target damping coefficient C LF of the first shock absorber being a positive value, and C LF <C 11 , the actual target damping coefficient of the first shock absorber is adjusted to C LF .
The control method of an adjustable damping suspension based on body attitude adjustment according to claim 6, wherein step 6 (S6) further comprises:

Set the maximum limit damping coefficient of the second shock absorber to C 21 and the minimum limit damping coefficient to C 22 ;

In response to the target damping coefficient C RF of the second shock absorber being a negative value, adjusting the actual target damping coefficient of the second shock absorber to C 22 ;

In response to the target damping coefficient C RF of the second shock absorber being a positive value, and C RF ≥ C 21 , adjust the actual target damping coefficient of the second shock absorber to C 21 ;

In response to the target damping coefficient C RF of the second shock absorber being a positive value, and C RF <C 21 , the actual target damping coefficient of the second shock absorber is adjusted to C RF .
The control method of an adjustable damping suspension based on body attitude adjustment according to claim 6, wherein step 6 (S6) further comprises:

Set the maximum limit damping coefficient of the third shock absorber to C 31 and the minimum limit damping coefficient to C 32 ;

In response to the target damping coefficient C LR of the third shock absorber being a negative value, adjusting the actual target damping coefficient of the third shock absorber to C 32 ;

In response to the target damping coefficient C LR of the third shock absorber being a positive value, and C LR ≥ C 31 , adjust the actual target damping coefficient of the third shock absorber to C 31 ;

In response to the target damping coefficient C LR of the third shock absorber being a positive value, and C LR <C 31 , the actual target damping coefficient of the third shock absorber is adjusted to C LR .
The control method of an adjustable damping suspension based on body attitude adjustment according to claim 6, wherein step 6 (S6) further comprises:

Set the maximum limit damping coefficient of the fourth shock absorber to C 41 and the minimum limit damping coefficient to C 42 ;

In response to the target damping coefficient C RR of the fourth shock absorber being a negative value, adjust the actual target damping coefficient of the fourth shock absorber to C 42 ;

In response to the target damping coefficient C RR of the fourth shock absorber being a positive value, and C RR ≥ C 41 , the actual target damping coefficient of the fourth shock absorber is adjusted to C 41 ;

In response to the target damping coefficient C RR of the fourth shock absorber being a positive value, and C RR <C 41 , the actual target damping coefficient of the fourth shock absorber is adjusted to C RR .