Method and system for synchronously adjusting vehicle height of four-wheeled vehicle

Abstract

The present invention belongs to the field of automobile suspension control technology, and specifically discloses a method and system for synchronously adjusting the height of a four-wheel automobile. It includes: calculating the proportion of the change in the height of the four-wheel suspension in the total change in the suspension height; calculating the minimum value of the variable height allowed by the four-wheel suspension per unit time, and the ratio of the variable height allowed by the four-wheel suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension; calculating the height change execution adjustment proportional coefficient of the four-wheel suspension; calculating the change in the height of each suspension per unit time; and calculating the instantaneous target height of each suspension at the current moment in real time based on the instantaneous target height of each suspension at the previous moment and the change in the height of each suspension per unit time, so as to achieve the synchronization of the height of the four-wheel suspension and simultaneously reach the steady-state target height. The total time used for the suspension of the present invention to dynamically rise and fall to the steady-state target height is the same, and the height changes of each suspension are synchronized, ensuring the smoothness and stability of the vehicle posture change.

Description

Technical Field

[0001] The present invention belongs to the technical field of automobile suspension control, and more specifically, relates to a method and system for synchronously adjusting the height of a four-wheeled automobile. Background Art

[0002] With the development and innovation of automobile chassis technology, hydraulic and air suspensions have emerged as automotive suspension systems. These suspensions' key functions are to adjust vehicle ground clearance, improving off-road maneuverability and handling. These adjustments include both driving and stationary height adjustments. Suspension height adjustment can easily lead to damage from over-capacity suspension adjustment, as well as uncoordinated height changes during suspension height adjustments, resulting in abnormal and unstable vehicle posture. For example, some suspension heights may rise and fall too quickly while others rise and fall too slowly, resulting in unstable vehicle posture and unusual vehicle posture variations with significant differences in suspension height.

[0003] Therefore, there is an urgent need to propose a method for synchronously adjusting the height of a four-wheeled vehicle in the art to solve the problem in the prior art that the vehicle posture changes abnormally or unsteadily due to the uncoordinated changes in the height of each suspension during the height raising and lowering process. Summary of the Invention

[0004] In response to the above-mentioned defects or improvement needs of the prior art, the present invention proposes a method and system for synchronously adjusting the vehicle height of a four-wheeled vehicle in order to solve the problem of abnormal vehicle posture changes or unstable vehicle posture changes caused by uncoordinated changes in the height of each suspension during the height raising and lowering process of the four-wheeled vehicle suspension.

[0005] To achieve the above object, according to one aspect of the present invention, a method for synchronously adjusting the height of a four-wheeled vehicle is provided, comprising the following steps:

[0006] S1 calculates the proportion of the four-wheel suspension height change in the total suspension height change;

[0007] S2 calculates the minimum value of the variable height allowed by the four-wheel suspension per unit time, and the ratio of the variable height allowed by the four-wheel suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension;

[0008] S3 calculates the height change of the four-wheel suspension according to the proportion obtained in step S1 and the ratio obtained in step S2 and performs an adjustment proportional coefficient;

[0009] S4 calculates the amount of change of each suspension height executed in a unit time based on the adjustment proportional coefficient of each suspension height change and the minimum value of the suspension variable height allowed by the four-wheel suspension in a unit time;

[0010] S5 calculates the instantaneous target height of each suspension at the current moment in real time based on the instantaneous target height of each suspension at the previous moment and the change in the height of each suspension per unit time, so as to achieve synchronization of the four-wheel suspension height and reach the steady-state target height at the same time.

[0011] As further preferred, step S1 includes the following steps:

[0012] S11 calculates the difference between the steady-state target height of the four-wheel suspension and the instantaneous target height at the previous moment;

[0013] S12 calculates in real time the sum of the absolute values ​​of the differences between the steady-state target height of the four-wheel suspension and the instantaneous target height at the previous moment;

[0014] S13 calculates the proportion of the four-wheel suspension height change in the total suspension height change, which is equal to the absolute value of the difference between the four-wheel suspension steady-state target height and its instantaneous target height at the previous moment divided by the total suspension height change.

[0015] As a further preferred embodiment, in step S12, the sum of the absolute values ​​of the differences between the steady-state target height of the four-wheel suspension and its instantaneous target height at the previous moment includes:

[0016] ΔH(k)=|ΔH(k) fl |+|ΔH(k) fr |+|ΔH(k) rl |+|ΔH(k) rr |

[0017] Where ΔH(k) fl is the difference between the steady-state target height of the left front suspension and its instantaneous target height at the previous moment; ΔH(k) fr is the difference between the steady-state target height of the right front suspension and its instantaneous target height at the previous moment; ΔH(k) rl is the difference between the steady-state target height of the left rear suspension and its instantaneous target height at the previous moment; ΔH(k) rr is the difference between the steady-state target height of the right rear suspension and its instantaneous target height at the previous moment; k is the current moment, and ΔH(k) is the total change in suspension height;

[0018] As a further preferred embodiment, in step S13, the proportion of the four-wheel suspension height change in the total suspension height change includes:

[0019]

[0020] Where, τ(k) fl is the proportion of the left front suspension height change in the total vehicle suspension height change; τ(k) fr is the proportion of the right front suspension height change in the total vehicle suspension height change; τ(k) rlis the proportion of the left rear suspension height change in the total vehicle suspension height change; τ(k) rr It is the proportion of the right rear suspension height change in the total vehicle suspension height change.

[0021] As a further preferred embodiment, in step S2, the ratio of the variable height allowed by the four-wheel suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension per unit time includes:

[0022]

[0023] Where, τ flmax is the ratio of the variable height allowed by the left front suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension per unit time, τ frmax is the ratio of the variable height allowed by the right front suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension per unit time, τ rlmax is the ratio of the variable height allowed by the left rear suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension per unit time, τ rrmax It is the ratio of the variable height allowed by the right rear suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension per unit time.

[0024] As further preferred, step S3 includes the following steps:

[0025] S31 calculates the maximum value of the ratio obtained in step S1 and the ratio obtained in step S2.

[0026] S32 calculates the height change adjustment proportional coefficient of the four-wheel suspension according to the maximum value obtained in step S31 and the proportion of the four-wheel suspension height change in the total suspension height change of the entire vehicle.

[0027] As a further preferred embodiment, in step S32, the step of calculating the height change of the four-wheel suspension and executing the adjustment proportional coefficient includes:

[0028]

[0029] Where, τ1(k) fl Performs an adjustment for the scaling factor for left front suspension height changes, τ1(k) fr Perform an adjustment for the scaling factor for right front suspension height changes, τ1(k) rl Performs an adjustment for the scaling factor for left rear suspension height changes, τ1(k) rr Performs an adjustment for the scaling factor for right rear suspension height changes, α(k) maxIt is the maximum value of the ratio of the proportion of each suspension height change in the total suspension height change of the whole vehicle to the ratio of the allowable variable height of each suspension per unit time to the minimum value of the allowable variable height of the four-wheel suspension per unit time, τ(k) fl is the proportion of the left front suspension height change in the total vehicle suspension height change, τ(k) fr is the proportion of the right front suspension height change in the total vehicle suspension height change, τ(k) rl is the proportion of the left rear suspension height change in the total vehicle suspension height change, τ(k) rr It is the proportion of the right rear suspension height change in the total vehicle suspension height change.

[0030] As a further preferred embodiment, in step S4, the change in each suspension height per unit time includes:

[0031]

[0032] Where ΔH1(k) fl ΔH1(k) is the change in suspension height per unit time of the left front suspension. fr ΔH1(k) is the change in the right front suspension height per unit time. rl ΔH1(k) is the change in suspension height per unit time of the left rear suspension. rr It is the change in suspension height of the right rear suspension per unit time.

[0033] As a further preferred embodiment, in step S5, the instantaneous target height of each suspension at the current moment is equal to the instantaneous target height of each suspension at the previous moment plus or minus the product of the change in the height of each suspension executed per unit time and the time interval of the task:

[0034]

[0035] Where H(k) fl is the instantaneous target height of the left front suspension at the current moment, H(k) fr is the instantaneous target height of the right front suspension at the current moment, H(k) rl is the instantaneous target height of the left rear suspension at the current moment, H(k) rr is the instantaneous target height of the right rear suspension at the current moment, and Δt is the time interval of the task.

[0036] As a further preferred embodiment, in step S5, steps S1 to S4 are repeated until the instantaneous target height of each suspension is equal to the steady-state target height.

[0037] According to another aspect of the present invention, there is also provided a system for synchronously adjusting the height of a four-wheeled vehicle, comprising:

[0038] The first main control module is used to calculate the proportion of the four-wheel suspension height change in the total suspension height change;

[0039] The second main control module is used to calculate the minimum value of the variable height allowed by the four-wheel suspension per unit time, and the ratio of the variable height allowed by the four-wheel suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension;

[0040] The third main control module is used to calculate the height change adjustment proportional coefficient of the four-wheel suspension according to the proportion obtained by the first main control module and the ratio obtained by the second main control module;

[0041] A fourth main control module is used to calculate the change amount of each suspension height in unit time based on the adjustment proportional coefficient of each suspension height change and the minimum value of the suspension variable height allowed by the four-wheel suspension in unit time;

[0042] The fifth main control module is used to calculate the instantaneous target height of each suspension at the current moment in real time based on the instantaneous target height of each suspension at the previous moment and the change in the height of each suspension per unit time, so as to achieve synchronization of the four-wheel suspension height and reach the steady-state target height at the same time.

[0043] In general, the above technical solutions conceived by the present invention have the following technical advantages compared with the existing technology:

[0044] 1. The present invention calculates the height change execution adjustment proportional coefficient of the four-wheel suspension based on the proportion of the four-wheel suspension height change in the total suspension height change, the minimum value of the four-wheel suspension allowed variable height per unit time, and the ratio of the four-wheel suspension allowed variable height per unit time to the minimum value of the four-wheel suspension allowed variable height. The change of each suspension height per unit time is calculated based on the adjustment proportional coefficient of each suspension height change and the minimum value of the four-wheel suspension allowed variable height per unit time. The instantaneous target height of each suspension at the current moment is calculated in real time based on the instantaneous target height of each suspension at the previous moment and the change of each suspension height per unit time, so as to achieve synchronization of the four-wheel suspension heights and simultaneously reach the steady-state target height.

[0045] 2. The method of the present invention takes into account the lifting capacity of the suspension per unit time during the lifting and lowering process of the suspension height, thereby avoiding damage to the suspension due to over-capacity operation and greatly improving the durability and working life of the suspension.

[0046] 3. The total time taken for the suspensions of the present invention to dynamically rise and fall to the steady-state target height is the same, and the height changes of each suspension are synchronized, ensuring the smoothness and stability of the vehicle posture changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1The present invention is a flowchart of a method for synchronously adjusting the height of a four-wheeled vehicle according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0049] like Figure 1 As shown, an embodiment of the present invention provides a method for synchronously adjusting the height of a four-wheeled vehicle, comprising the following steps:

[0050] Step 1: Calculate the difference between the steady-state target height of the four-wheel suspension and its instantaneous target height at the previous moment.

[0051]

[0052] Among them: H fl ——Standard target height of left front wheel suspension; H fr ——right front wheel suspension steady-state target height; H rl ——Standard target height of left rear wheel suspension; H rr —— Steady-state target height of the right rear wheel suspension; H(k-1) fl ——The instantaneous target height of the left front wheel suspension at the previous moment; H(k-1) fr ——The instantaneous target height of the right front wheel suspension at the previous moment; H(k-1) rl ——The instantaneous target height of the left rear wheel suspension at the previous moment; H(k-1) rr ——The instantaneous target height of the right rear wheel suspension at the previous moment; ΔH(k) fl ——The difference between the steady-state target height of the left front suspension and its instantaneous target height at the previous moment; ΔH(k) fr ——The difference between the steady-state target height of the right front suspension and its instantaneous target height at the previous moment; ΔH(k) rl ——The difference between the steady-state target height of the left rear suspension and its instantaneous target height at the previous moment; ΔH(k) rr ——The difference between the steady-state target height of the right rear suspension and its instantaneous target height at the previous moment; k——the current moment, and k-1 is the previous moment.

[0053] Furthermore, we know that: ΔH(k) fl =0, it means that the steady-state target height of the left front suspension is the same as its instantaneous target height at the previous moment, and no lifting adjustment is required; ΔH(k) fl>0, it means that the steady-state target height of the left front suspension is greater than its instantaneous target height at the previous moment, and the suspension should be raised; ΔH(k) fl <0, it means that the steady-state target height of the left front suspension is less than its instantaneous target height at the previous moment, and the suspension should be lowered; ΔH(k) fr , ΔH(k) rl , ΔH(k) rr The meaning of the representation is the same as the physical meaning.

[0054] Step 2: Calculate in real time the absolute sum of the differences between the steady-state target height of the four-wheel suspension and its instantaneous target height at the previous moment to represent the total change in the four-wheel suspension height.

[0055] ΔH(k)=|ΔH(k) fl |+|ΔH(k) fr |+|ΔH(k) rl |+|ΔH(k) rr |

[0056] Where: ΔH(k) – total change in suspension height;

[0057] Step 3: Calculate the proportion of the four-wheel suspension height change to the total suspension height change. This proportion is equal to the absolute value of the difference between the four-wheel suspension steady-state target height and its previous instantaneous target height divided by the total suspension height change.

[0058]

[0059] Where: τ(k) fl ——The proportion of the left front suspension height change in the total vehicle suspension height change; τ(k) fr ——Right front suspension height change as a percentage of the total vehicle suspension height change; τ(k) rl ——The proportion of the left rear suspension height change in the total vehicle suspension height change; τ(k) rr ——The proportion of the right rear suspension height change in the total vehicle suspension height change.

[0060] Step 4: Calculate the minimum value of the variable height allowed by the four-wheel suspension in unit time. This minimum value represents the ability of the four-wheel suspension to work simultaneously in unit time.

[0061] ΔH min =min(ΔH flmax , ΔH frmax , ΔH rlmax , ΔH rrmax )

[0062] Where: ΔH min ——The minimum value of the variable height allowed by the four-wheel suspension per unit time; ΔHflmax ——The allowed variable height of the left front suspension per unit time; ΔH frmax ——The right front suspension allows variable height per unit time; ΔH rlmax ——The variable height allowed for the left rear suspension per unit time; ΔH rrmax ——The right rear suspension allows variable height per unit time; ΔH flmax , ΔH frmax , ΔH rlmax , ΔH rrmax It is a characteristic parameter of each suspension, representing the working capacity of the left front suspension, right front suspension, left rear suspension, and right rear suspension per unit time. If the height change of the suspension per unit time exceeds this value, the suspension may be damaged or its durability life may be reduced.

[0063] Step 5: The ratio of the variable height allowed by the four-wheel suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension per unit time.

[0064]

[0065] Where: τ flmax ——The ratio of the variable height of the left front suspension per unit time to the minimum variable height of the four-wheel suspension per unit time; τ frmax ——The ratio of the right front suspension's variable height per unit time to the minimum value of the four-wheel suspension's variable height per unit time; τ rlmax ——The ratio of the variable height of the left rear suspension allowed per unit time to the minimum variable height of the four-wheel suspension allowed per unit time; τ rrmax ——The ratio of the variable height allowed by the right rear suspension per unit time to the minimum variable height allowed by the four-wheel suspension per unit time.

[0066] Furthermore, we know that: ΔH flmax , ΔH frmax , ΔH rlmax , ΔH rrmax

[0067]

[0068] Step 6: Calculate the ratio of the proportion of the four-wheel suspension height change in the total suspension height change to the ratio of the allowable variable height of each suspension per unit time to the minimum value of the four-wheel suspension allowable variable height per unit time.

[0069]

[0070] Where: α(k) fl—Ratio of the proportion of the left front suspension height change in the total suspension height change to the ratio of the allowable variable height of each suspension per unit time to the minimum value of the allowable variable height of the four-wheel suspension per unit time; α(k) fr -Ratio of the right front suspension height change to the total suspension height change to the ratio of the allowable variable height of each suspension per unit time to the minimum allowable variable height of the four-wheel suspension per unit time; α(k) rl -The ratio of the left rear suspension height change to the total suspension height change and the ratio of the allowable variable height of each suspension per unit time to the minimum allowable variable height of the four-wheel suspension per unit time; α(k) rr -The ratio of the right rear suspension height change to the total suspension height change and the ratio of the allowable variable height of each suspension per unit time to the minimum allowable variable height of the four-wheel suspension per unit time.

[0071] Furthermore, we can know that:

[0072]

[0073] Step 7: Calculate the maximum value of the ratio of the four-wheel suspension height change to the total suspension height change of the entire vehicle and the ratio of the allowable variable height of each suspension per unit time to the minimum value of the four-wheel suspension allowable variable height per unit time.

[0074] α(k) max =max(α(k) fl ,α(k) fr ,α(k) rl ,α(k) rr )

[0075] Where: α(k) max ——The maximum value of the ratio of the proportion of each suspension height change in the total suspension height change of the suspension vehicle and the ratio of the allowable variable height of each suspension per unit time to the minimum value of the allowable variable height of the four-wheel suspension per unit time.

[0076] Furthermore, we can know that:

[0077]

[0078] Step 8: Calculate the height change adjustment proportional coefficient of the four-wheel suspension based on the maximum value of the ratio of the proportion of the four-wheel suspension height change in the total suspension height change, the proportion of each suspension height change in the total suspension height change, and the ratio of the allowable variable height of each suspension per unit time to the minimum value of the allowable variable height of the four-wheel suspension per unit time.

[0079]

[0080] Where: τ1(k) fl ——Left front suspension height change execution adjustment proportional coefficient; τ1(k) fr ——Right front suspension height change execution adjustment proportional coefficient; τ1(k) rl ——Left rear suspension height change execution adjustment proportional coefficient; τ1(k) rr ——Right rear suspension height change execution adjustment proportional coefficient.

[0081] Furthermore, we know that: τ1(k) fl 、τ1(k) fr 、τ1(k) rl 、τ1(k) rr With τ flmax , τ frmax , τ rlmax , τ rrmax The relative size relationship:

[0082]

[0083] is equivalent to:

[0084]

[0085] Step 9: Calculate the amount of change of each suspension height per unit time based on the adjustment proportional coefficient of each suspension height change and the minimum value of the suspension variable height allowed by the four-wheel suspension per unit time.

[0086]

[0087] Where: ΔH1(k) fl ——The change in suspension height per unit time of the left front suspension; ΔH1(k) fr ——The change in suspension height per unit time of the right front suspension; ΔH1(k) rl ——The change in suspension height per unit time of the left rear suspension; ΔH1(k) rr ——The change in suspension height of the right rear suspension per unit time.

[0088] Furthermore, we can know that:

[0089]

[0090] is equivalent to:

[0091]

[0092] It can be seen that the change in the height of each suspension per unit time will never be greater than the allowable variable height of each suspension per unit time, which avoids damage to the suspension due to over-capacity operation and improves the durability and working life of the suspension.

[0093] Step 10: Calculate the current instantaneous target height of each suspension in real time based on the previous instantaneous target height of each suspension and the change in each suspension height per unit time. The current instantaneous target height of each suspension is equal to the product of the previous instantaneous target height of each suspension plus or minus the change in each suspension height per unit time and the time interval of the task.

[0094]

[0095] Where: H(k) fl ——The instantaneous target height of the left front suspension at the current moment; H(k) fr ——The instantaneous target height of the right front suspension at the current moment;

[0096] H(k) rl ——The instantaneous target height of the left rear suspension at the current moment; H(k) rr ——The instantaneous target height of the right rear suspension at the current moment; Δt——The time interval of the task.

[0097] Furthermore, steps 1 to 9 are continuously cycled, and at the end of each single cycle, the instantaneous target height of each suspension at the previous moment is updated. The updating method is that the instantaneous target height of the suspension at the previous moment is equal to the instantaneous target height of the suspension at the current moment, that is:

[0098]

[0099] Furthermore, after multiple cycles of steps 1 to 9, the instantaneous target height of each suspension at the current moment is equal to the steady-state target height, that is:

[0100]

[0101] Furthermore, it can be seen that the height change of each suspension height to the steady-state target height is ΔH(k) fl , ΔH(k) fr , ΔH(k) rl , ΔH(k) rr , and at the same time combine the change in each suspension height per unit time ΔH1(k) fl , ΔH1(k) fr , ΔH1(k) rl , ΔH1(k) rr , we can know that the time for change adjustment is calculated as the height change divided by the change in each suspension height per unit time, that is:

[0102]

[0103] Where: Δt fl ——The time for the left front suspension to change and adjust; Δtfr ——The time for the right front suspension to change and adjust; Δt rl ——The time for the left rear suspension to change and adjust; Δt rr ——The time for adjusting the right rear suspension changes.

[0104] Furthermore, we can know that:

[0105]

[0106] Furthermore, we can know that:

[0107]

[0108] Furthermore, we can know that:

[0109]

[0110] Furthermore, we can know that:

[0111]

[0112] Furthermore, we can know that: Δt fl =Δt fr =Δt rl =Δt rr This shows that the four-wheel suspension takes the same amount of time to dynamically adjust to the steady-state target height, meaning they reach the steady-state target height simultaneously, ensuring smooth adjustments to the vehicle's posture.

[0113] According to another aspect of the present invention, a system for implementing the method involved in any of the above embodiments is also provided, including:

[0114] The first main control module is used to calculate the proportion of the four-wheel suspension height change in the total suspension height change;

[0115] The second main control module is used to calculate the minimum value of the variable height allowed by the four-wheel suspension per unit time, and the ratio of the variable height allowed by the four-wheel suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension;

[0116] The third main control module is used to calculate the height change adjustment proportional coefficient of the four-wheel suspension according to the proportion obtained by the first main control module and the ratio obtained by the second main control module;

[0117] A fourth main control module is used to calculate the change amount of each suspension height in unit time based on the adjustment proportional coefficient of each suspension height change and the minimum value of the suspension variable height allowed by the four-wheel suspension in unit time;

[0118] The fifth main control module is used to calculate the instantaneous target height of each suspension at the current moment in real time based on the instantaneous target height of each suspension at the previous moment and the change in the height of each suspension per unit time, so as to achieve synchronization of the four-wheel suspension height and reach the steady-state target height at the same time.

[0119] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for synchronously adjusting the height of a four-wheeled vehicle, characterized in that: The following steps are involved: S1 calculates the proportion of the four-wheel suspension height change in the total suspension height change; S2 calculates the minimum value of the variable height allowed by the four-wheel suspension per unit time, and the ratio of the variable height allowed by the four-wheel suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension; S3 calculates the height change of the four-wheel suspension according to the proportion obtained in step S1 and the ratio obtained in step S2 and performs an adjustment proportional coefficient; S4 calculates the amount of change of each suspension height executed in a unit time based on the adjustment proportional coefficient of each suspension height change and the minimum value of the suspension variable height allowed by the four-wheel suspension in a unit time; S5 calculates the instantaneous target height of each suspension at the current moment in real time based on the instantaneous target height of each suspension at the previous moment and the change in the height of each suspension per unit time, so as to achieve synchronization of the four-wheel suspension height and reach the steady-state target height at the same time.

2. A method for synchronously adjusting the height of a four-wheeled vehicle according to claim 1, characterized in that: Step S1 includes the following steps: S11 calculates the difference between the steady-state target height of the four-wheel suspension and the instantaneous target height at the previous moment; S12 calculates in real time the sum of the absolute values ​​of the differences between the steady-state target height of the four-wheel suspension and the instantaneous target height at the previous moment; S13 calculates the proportion of the four-wheel suspension height change in the total suspension height change, which is equal to the absolute value of the difference between the four-wheel suspension steady-state target height and its instantaneous target height at the previous moment divided by the total suspension height change.

3. A method for synchronously adjusting the height of a four-wheeled vehicle according to claim 2, characterized in that: In step S12, the sum of the absolute values ​​of the differences between the steady-state target height of the four-wheel suspension and the instantaneous target height at the previous moment includes: ΔH(k)=|ΔH(k) fl |+|ΔH(k) fr |+|ΔH(k) rl |+|ΔH(k) rr | Where ΔH(k) fl is the difference between the steady-state target height of the left front suspension and its instantaneous target height at the previous moment; ΔH(k) fr is the difference between the steady-state target height of the right front suspension and its instantaneous target height at the previous moment; ΔH(k) rl is the difference between the steady-state target height of the left rear suspension and its instantaneous target height at the previous moment; ΔH(k) rr is the difference between the steady-state target height of the right rear suspension and its instantaneous target height at the previous moment; k is the current moment, and ΔH(k) is the total change in suspension height; In step S13, the proportion of the four-wheel suspension height change in the total suspension height change includes: Wherein, 𝜏(𝑘)𝑓l is the proportion of the left front suspension height change in the total vehicle suspension height change; 𝜏(𝑘)𝑓r is the proportion of the right front suspension height change in the total vehicle suspension height change; 𝜏(𝑘)rl is the proportion of the left rear suspension height change in the total vehicle suspension height change; 𝜏(𝑘)rr is the proportion of the right rear suspension height change in the total vehicle suspension height change.

4. A method for synchronously adjusting the height of a four-wheeled vehicle according to claim 1, characterized in that: In step S2, the ratio of the variable height allowed by the four-wheel suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension per unit time includes: Where 𝜏 flmax is the ratio of the variable height allowed by the left front suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension per unit time, 𝜏 frmax is the ratio of the variable height allowed by the right front suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension per unit time, 𝜏 rlmax is the ratio of the variable height allowed by the left rear suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension per unit time, 𝜏 rrmax ΔH is the ratio of the right rear suspension's variable height per unit time to the minimum value of the four-wheel suspension's variable height per unit time. min ΔH is the minimum value of the variable height allowed by the four-wheel suspension in unit time; flmax ΔH is the variable height allowed for the left front suspension per unit time; frmax The right front suspension is allowed to change height per unit time; ΔH rlmax The left rear suspension is allowed to change height per unit time; ΔH rrmax The right rear suspension allows variable height per unit time.

5. A method for synchronously adjusting the height of a four-wheeled vehicle according to claim 1, characterized in that: Step S3 includes the following steps: S31 calculates the maximum value of the ratio obtained in step S1 and the ratio obtained in step S2. S32 calculates the height change adjustment proportional coefficient of the four-wheel suspension according to the maximum value obtained in step S31 and the proportion of the four-wheel suspension height change in the total suspension height change of the entire vehicle.

6. A method for synchronously adjusting the height of a four-wheeled vehicle according to claim 5, characterized in that: In step S32, the calculation of the height change of the four-wheel suspension and the execution adjustment proportional coefficient include: Where 𝜏1(k) fl Perform an adjustment for the scaling factor for the left front suspension height change, 𝜏1(k) fr Perform an adjustment for the scaling factor for the right front suspension height change, 𝜏1(k) rl Perform an adjustment for the scaling factor for the left rear suspension height change, 𝜏1(k) rr Perform an adjustment for the scaling factor for the right rear suspension height change, 𝛼(k) max It is the maximum value of the ratio of the proportion of each suspension height change in the total suspension height change of the whole vehicle to the ratio of the allowable variable height of each suspension per unit time to the minimum value of the allowable variable height of the four-wheel suspension per unit time, 𝜏(k) fl is the proportion of the left front suspension height change in the total vehicle suspension height change, 𝜏(k) fr is the proportion of the right front suspension height change in the total vehicle suspension height change, 𝜏(k) rl is the proportion of the left rear suspension height change in the total vehicle suspension height change, 𝜏(k) rr It is the proportion of the right rear suspension height change in the total vehicle suspension height change.

7. A method for synchronously adjusting the height of a four-wheeled vehicle according to claim 1, characterized in that: In step S4, the change in each suspension height per unit time includes: Where ΔH1(k) fl ΔH1(k) is the change in suspension height per unit time of the left front suspension. fr ΔH1(k) is the change in the right front suspension height per unit time. rl ΔH1(k) is the change in suspension height per unit time of the left rear suspension. rr is the change in the suspension height of the right rear suspension per unit time, 𝜏1(k) fl Perform an adjustment for the scaling factor for the left front suspension height change; 𝜏1(k) fr Perform an adjustment for the scaling factor for the right front suspension height change; 𝜏1(k) rl Perform an adjustment for the scaling factor for the left rear suspension height change; 𝜏1(k) rr Performs an adjustment for the right rear suspension height change, ΔH min It is the minimum value of the variable suspension height allowed by the four-wheel suspension per unit time.

8. A method for synchronously adjusting the height of a four-wheeled vehicle according to claim 1, characterized in that: In step S5, the instantaneous target height of each suspension at the current moment is equal to the instantaneous target height of each suspension at the previous moment plus or minus the product of the change in the height of each suspension per unit time and the time interval of the task: Where H(k) fl is the instantaneous target height of the left front suspension at the current moment, H(k) fr is the instantaneous target height of the right front suspension at the current moment, H(k) rl is the instantaneous target height of the left rear suspension at the current moment, H(k) rr is the instantaneous target height of the right rear suspension at the current moment, Δt is the time interval of the task, ΔH(k) fl is the difference between the steady-state target height of the left front suspension and its instantaneous target height at the previous moment; ΔH(k) fr is the difference between the steady-state target height of the right front suspension and its instantaneous target height at the previous moment; ΔH(k) rl is the difference between the steady-state target height of the left rear suspension and its instantaneous target height at the previous moment; ΔH(k) rr It is the difference between the steady-state target height of the right rear suspension and its instantaneous target height at the previous moment.

9. A method for synchronously adjusting the height of a four-wheeled vehicle according to claim 1, characterized in that: In step S5, steps S1 to S4 are repeated until the instantaneous target height of each suspension is equal to the steady-state target height.

10. A four-wheel vehicle height synchronization adjustment system, characterized in that: include: The first main control module is used to calculate the proportion of the four-wheel suspension height change in the total suspension height change; The second main control module is used to calculate the minimum value of the variable height allowed by the four-wheel suspension per unit time, and the ratio of the variable height allowed by the four-wheel suspension per unit time to the minimum value of the variable height allowed by the four-wheel suspension; The third main control module is used to calculate the height change adjustment proportional coefficient of the four-wheel suspension according to the proportion obtained by the first main control module and the ratio obtained by the second main control module; A fourth main control module is used to calculate the change amount of each suspension height in unit time based on the adjustment proportional coefficient of each suspension height change and the minimum value of the suspension variable height allowed by the four-wheel suspension in unit time; The fifth main control module is used to calculate the instantaneous target height of each suspension at the current moment in real time based on the instantaneous target height of each suspension at the previous moment and the change in the height of each suspension per unit time, so as to achieve synchronization of the four-wheel suspension height and reach the steady-state target height at the same time.

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