A multi-axle vehicle suspension control method

Abstract

The present application discloses a multi-axis automobile suspension control method, which relates to the field of automobile suspension, including collecting the current posture data of the vehicle and the target posture data set by the user; respectively calculating the theoretical adjustment height and theoretical target height of the suspensions on both sides of all axles of the vehicle when the vehicle is adjusted to the target angle between the vehicle X direction and the road surface and the target angle between the vehicle Y direction and the road surface, wherein the road surface is the road surface in contact with any wheel; extracting the theoretical maximum value and the theoretical minimum value from all theoretical target heights, combining the theoretical maximum value, the theoretical minimum value, and the upper and lower travel limit values ​​of the suspension, obtaining the actual target height of the suspensions on both sides of all axles, and adjusting the height of each suspension according to the actual target height, wherein the actual target height does not exceed the upper and lower travel limit values ​​of the suspension. The present application can adaptively adjust and control the vehicle posture under the conditions that the vehicle has many axles, the wheelbases of each axle are different, and the road surface is uneven.

Description

Technical Field

[0001] The present application relates to the technical field of automobile suspension, and in particular to a multi-axis automobile suspension control method. Background Art

[0002] Special vehicles are equipped with a hydraulic suspension system, which uses the hydraulic system to adjust the suspension height of each wheel to meet the needs of adjusting the vehicle's posture.

[0003] However, when the vehicle has many axles and the road surface is uneven, it is necessary to set a method for calculating the height of each wheel suspension. Otherwise, the reasonable rise and fall of each wheel suspension cannot be achieved, and the goal of vehicle posture adjustment cannot be achieved. Summary of the invention

[0004] In view of the defects existing in the prior art, the purpose of the present application is to provide a multi-axle automobile suspension control method, which can adaptively adjust and control the vehicle posture under conditions where the vehicle has a large number of axles, the wheelbases of each axle are different, and the road surface is uneven.

[0005] In order to achieve the above objectives, the technical solutions adopted are:

[0006] The first aspect of the present application provides a multi-axis vehicle suspension control method.

[0007] Collecting the current posture data of the vehicle and the target posture data set by the user; the current posture data includes the current ground clearance of the suspensions on both sides of all axles, the current pitch angle between the vehicle X-direction and the road surface, and the current lateral inclination angle between the vehicle Y-direction and the road surface; the target posture data includes the target pitch angle between the vehicle X-direction and the road surface and the target lateral inclination angle between the vehicle Y-direction and the road surface; the road surface is the road surface in contact with any wheel;

[0008] Calculating respectively the theoretical adjustment height and the theoretical target height of the suspension on both sides of all axles of the vehicle when the vehicle is adjusted to the target pitch angle and the target lateral tilt angle; the theoretical target height is the sum of the current ground clearance of the suspension and the theoretical adjustment height;

[0009] The theoretical maximum value and the theoretical minimum value are extracted from the theoretical target heights of all suspensions, and the actual target heights of the suspensions on both sides of all axles are obtained by combining the theoretical maximum value, the theoretical minimum value, and the upper and lower travel limits of the suspensions. The height of each suspension is adjusted according to the actual target height, and the actual target height does not exceed the upper and lower travel limits of the suspensions.

[0010] In some embodiments, the theoretical adjustment height of the suspension on both sides of all axles caused by the change in the pitch angle between the vehicle X-direction and the road surface is calculated using the following formula:

[0011]

[0012] in,

[0013] It means that when the pitch angle between the vehicle X direction and the road surface is adjusted to the target pitch angle, Theoretical adjustment height of the suspension on the right side of the axle;

[0014] It means that when the pitch angle between the vehicle X direction and the road surface is adjusted to the target pitch angle, Theoretical adjustment height of the suspension on the left side of the axle;

[0015] i represents the axis sequence from the front to the rear of the vehicle;

[0016] Indicates the vehicle's The wheelbase from axle to the nth axle; n represents the total number of axles of the vehicle;

[0017] represents the pitch angle of the target;

[0018] Indicates the current side inclination angle.

[0019] In some embodiments, the theoretical adjustment height of the suspensions on both sides of all axles caused by the change in the lateral inclination angle between the vehicle in the Y direction and the road surface is calculated using the following formula:

[0020]

[0021] in,

[0022] Indicates that when the lateral inclination angle between the vehicle Y direction and the road surface is adjusted to the target lateral inclination angle, Theoretical adjustment height of the suspension on the right side of the axle;

[0023] Indicates that when the lateral inclination angle between the vehicle Y direction and the road surface is adjusted to the target lateral inclination angle, Theoretical adjustment height of the suspension on the left side of the axle;

[0024] Indicates the vehicle's Track width of the axle;

[0025] represents the target side inclination angle;

[0026] Indicates the current pitch angle.

[0027] In some embodiments, when the pitch angle between the vehicle X-direction and the road surface is adjusted to the target pitch angle, and the lateral inclination angle between the vehicle Y-direction and the road surface is adjusted to the target lateral inclination angle, the total theoretical adjustment height of each suspension caused by the change in vehicle posture is calculated using the following formula:

[0028]

[0029] in,

[0030] Indicates the first The total theoretical adjusted height of the suspension on the right side of the axle;

[0031] Indicates the first The total theoretical adjustment height of the suspension on the left side of the axle;

[0032] It means that when the pitch angle between the vehicle X direction and the road surface is adjusted to the target pitch angle, Theoretical adjustment height of the suspension on the right side of the axle;

[0033] It means that when the pitch angle between the vehicle X direction and the road surface is adjusted to the target pitch angle, Theoretical adjustment height of the suspension on the left side of the axle;

[0034] Indicates that when the lateral inclination angle between the vehicle Y direction and the road surface is adjusted to the target lateral inclination angle, Theoretical adjustment height of the suspension on the right side of the axle;

[0035] Indicates that when the lateral inclination angle between the vehicle Y direction and the road surface is adjusted to the target lateral inclination angle, Theoretical adjusted height of the suspension on the left side of the axle.

[0036] In some embodiments, when the pitch angle between the vehicle X-direction and the road surface is adjusted to the target pitch angle, and the lateral inclination angle between the vehicle Y-direction and the road surface is adjusted to the target lateral inclination angle, the theoretical target height of each suspension of the vehicle is calculated using the following formula:

[0037]

[0038] in,

[0039] Indicates the vehicle's Theoretical target height of the suspension on the right side of the axle;

[0040] Indicates the vehicle's Theoretical target height of the suspension on the left side of the axle;

[0041] Indicates the vehicle Current ground clearance of the suspension on the right side of the axle;

[0042] Indicates the vehicle Current ground clearance of the suspension on the left side of the axle;

[0043] Indicates the first The total theoretical adjusted height of the suspension on the right side of the axle;

[0044] Indicates the first Theoretical total adjusted height of the suspension on the left side of the axle.

[0045] In some embodiments, the suspension upper and lower travel limit values ​​include a suspension upper travel limit value when the suspension is adjusted upward and a suspension lower travel limit value when the suspension is adjusted downward;

[0046] The actual target height of the suspensions on both sides of all axles is obtained by combining the theoretical maximum value, the theoretical minimum value, and the suspension upper and lower travel limit values, and the height of each suspension is adjusted according to the actual target height. The specific steps are as follows:

[0047] respectively calculating a first difference between a theoretical maximum value and an upper suspension travel limit value, and a second difference between a lower suspension travel limit value and a theoretical minimum value;

[0048] When both the first difference and the second difference are positive numbers, the theoretical target height is compressed until both the first difference and the second difference are not positive numbers;

[0049] When the first difference is not positive and the second difference is positive, if the absolute value of the first difference is not less than the absolute value of the second difference, the absolute value of the second difference is added to the theoretical target height to obtain the actual target height; if the absolute value of the first difference is less than the absolute value of the second difference, the actual target height adopts the smaller value of the suspension upper travel limit value or the value obtained by adding the absolute value of the second difference to the theoretical target height;

[0050] When the first difference is positive and the second difference is not positive, if the absolute value of the first difference is not greater than the absolute value of the second difference, the absolute value of the first difference is subtracted from the theoretical target height to obtain the actual target height; if the absolute value of the first difference is greater than the absolute value of the second difference, the actual target height adopts the suspension lower travel limit value or the value obtained by subtracting the absolute value of the first difference from the theoretical target height, whichever is greater;

[0051] When both the first difference and the second difference are not positive numbers, the theoretical target height is used as the actual target height, and the height of each suspension is adjusted according to the actual target height.

[0052] In some embodiments, when the first difference is positive and the second difference is positive, the vehicle first difference is calculated using the following formula: Selection factor for suspension on the right side of the axle:

[0053]

[0054] in,

[0055] Indicates vehicle Selection factor for the suspension on the right side of the axle;

[0056] Indicates the vehicle's Target height of suspension on the right side of the axle;

[0057] Indicates the travel limit value of the suspension;

[0058] Indicates the suspension lower travel limit value;

[0059] When the first difference is positive and the second difference is positive, the vehicle's Selection factor for suspension on the left side of the axle:

[0060]

[0061] in,

[0062] Indicates vehicle Selection factor for the suspension on the left side of the axle;

[0063] Indicates the vehicle's Target height of the suspension on the left side of the axle.

[0064] In some embodiments, the actual adjustment height of the suspensions on both sides of all axles is calculated using the following formula:

[0065]

[0066] in,

[0067] Indicates vehicle Actual target height of the suspension on the right side of the axle;

[0068] Indicates vehicle Actual target height of the suspension on the left side of the axle.

[0069] In some embodiments, when the first difference is not positive and the second difference is positive, the specific content of the calculation strategy is as follows:

[0070] When the absolute value of the first difference is not less than the absolute value of the second difference, the actual target height of the suspension on both sides of all axles is calculated using the following formula:

[0071]

[0072] in,

[0073] Indicates vehicle Actual target height of the suspension on the right side of the axle;

[0074] Indicates vehicle Actual target height of the suspension on the left side of the axle;

[0075] Indicates the vehicle's Theoretical target height of the suspension on the right side of the axle;

[0076] Indicates the vehicle's Theoretical target height of the suspension on the left side of the axle;

[0077] A second difference between the suspension lower travel limit value and the theoretical minimum value;

[0078] When the absolute value of the first difference is less than the absolute value of the second difference, the actual target height of the suspension on both sides of all axles is calculated using the following formula:

[0079]

[0080] in,

[0081] Indicates the suspension travel limit value.

[0082] In some embodiments, when the first difference is positive and the second difference is not positive, the calculation strategy is specifically as follows:

[0083] When the absolute value of the first difference is not greater than the absolute value of the second difference, the actual target height of the suspension on both sides of all axles is calculated using the following formula:

[0084]

[0085] in,

[0086] Indicates vehicle Actual target height of the suspension on the right side of the axle;

[0087] Indicates vehicle Actual target height of the suspension on the left side of the axle;

[0088] Indicates the vehicle's Target height of suspension on the right side of the axle;

[0089] Indicates the vehicle's Target height of suspension on the left side of the axle;

[0090] represents a first difference between the maximum value and the suspension upper travel limit value;

[0091] When the absolute value of the first difference is greater than the absolute value of the second difference, the actual target height of the suspension on both sides of all axles is calculated using the following formula:

[0092]

[0093] in,

[0094] Indicates the suspension lower travel limit value.

[0095] The beneficial effects of the technical solution provided by this application include:

[0096] The target posture of the vehicle can be set arbitrarily according to the driver's needs and the target posture control can be achieved.

[0097] The influence of the wheelbase difference of different axles of multi-axle vehicles on the suspension height is taken into account to improve the control accuracy.

[0098] By calculating the change in each suspension degree and adding the original height to get the target height, the vehicle's target posture control can be automatically achieved even if the vehicle is parked on an uneven road, thereby improving the adjustment ability of the suspension system and its actual engineering application ability.

[0099] The travel capacity range of the suspension is taken into consideration to ensure that the height of each suspension is always within the travel range, avoiding the risk of damage due to over-capacity of the suspension system, protecting each suspension system, and improving the reliability and life of the suspension. BRIEF DESCRIPTION OF THE DRAWINGS

[0100] Figure 1 The flowchart of the multi-axle vehicle suspension control method in the embodiment of the present invention. DETAILED DESCRIPTION

[0101] The present application is further described in detail below with reference to the accompanying drawings and embodiments.

[0102] like Figure 1 As shown, an embodiment of the present invention provides a multi-axis automobile suspension control method, including collecting current posture data and target posture data of the vehicle, the current posture data reflects the current posture of the vehicle, and the target posture data can be set according to user needs to reflect the target posture of the vehicle after adjustment. When the pitch angle between the vehicle X direction and the road surface is adjusted to the target pitch angle and the lateral inclination angle between the vehicle Y direction and the road surface is adjusted to the target lateral inclination angle, the theoretical adjustment height and theoretical target height of the suspension on both sides of all axles of the vehicle are calculated respectively, and the theoretical target height is the sum of the current ground clearance height and the theoretical adjustment height of the suspension. Through the theoretical adjustment height of each suspension on both sides of different axles when performing posture adjustment and the theoretical target height that can be achieved after posture adjustment, the suspension on both sides of axles with different wheelbases can be adjusted in the future. The above-mentioned road surface can be selected as the road surface that contacts any wheel of the vehicle on the road where the vehicle is located.

[0103] Furthermore, the theoretical maximum value and the theoretical minimum value are extracted from the theoretical target heights of all suspensions, and the actual target heights of the suspensions on both sides of all axles are obtained by combining the theoretical maximum value, the theoretical minimum value, and the suspension upper and lower travel limits. The actual target height does not exceed the suspension upper and lower travel limits. The actual target height reflects the actual ground clearance that can be achieved after the actual adjustment of each suspension. By considering the travel capacity range of the suspension, it is ensured that the height of each suspension is always within the travel range, avoiding the risk of damage to the suspension system due to overcapacity, protecting each suspension system, and improving the reliability and life of the suspension.

[0104] In a specific embodiment, a multi-axle vehicle suspension control method includes:

[0105] Step S1, collecting the current posture data of the vehicle and the target posture data set by the user; the current posture data includes the current ground clearance of the suspensions on both sides of all axles, the current pitch angle between the vehicle X direction and the road surface, and the current lateral inclination angle between the vehicle Y direction and the road surface. The target posture data includes the target pitch angle between the vehicle X direction and the road surface and the target lateral inclination angle between the vehicle Y direction and the road surface; the road surface is the road surface in contact with any wheel.

[0106] Step S2, respectively calculating the theoretical adjustment height and theoretical target height of the suspension on both sides of all axles of the vehicle when the vehicle is adjusted to the target pitch angle and the target lateral tilt angle. The theoretical target height is the sum of the current ground clearance of the suspension and the theoretical adjustment height.

[0107] Step S3, extracting the theoretical maximum value and the theoretical minimum value from the theoretical target heights of all suspensions, combining the theoretical maximum value, the theoretical minimum value, and the upper and lower travel limits of the suspensions, to obtain the actual target heights of the suspensions on both sides of all axles, and adjusting the height of each suspension according to the actual target height, wherein the actual target height does not exceed the upper and lower travel limits of the suspensions.

[0108] In a preferred embodiment, the theoretical adjustment height of the suspension on both sides of all axes caused by the change in the pitch angle between the vehicle X-axis and the road surface is calculated using the following formula (1):

[0109] (1)

[0110] in, Indicates that when the pitch angle between the vehicle's X direction and the road surface is adjusted to the target pitch angle, Theoretical adjusted height of the suspension on the right side of the axle. Indicates that when the pitch angle between the vehicle's X direction and the road surface is adjusted to the target pitch angle, Theoretical adjustment height of the suspension on the left side of the axle. i indicates the sequence of the axles from the front to the rear of the vehicle. Indicates the vehicle's The wheelbase from axle to the nth axle. n represents the total number of axles of the vehicle. Indicates the target pitch angle. Indicates the current side inclination angle.

[0111] In a preferred embodiment, the theoretical adjustment height of the suspensions on both sides of all axles caused by the change in the lateral inclination angle between the vehicle in the Y direction and the road surface is calculated using the following formula (2):

[0112] (2)

[0113] in, Indicates that when the lateral inclination angle between the vehicle Y direction and the road surface is adjusted to the target lateral inclination angle, Theoretical adjusted height of the suspension on the right side of the axle. Indicates that when the lateral inclination angle between the vehicle Y direction and the road surface is adjusted to the target lateral inclination angle, Theoretical adjusted height of the suspension on the left side of the axle. Indicates the vehicle's Axle track. Indicates the target side inclination angle. Indicates the current pitch angle.

[0114] In this embodiment, the height sensor configured for each wheel suspension system detects the current ground clearance of each suspension from the ground. , the vehicle is equipped with lateral and longitudinal sensors to monitor the current pitch angle of the vehicle The angle between the current side inclination and i is the number of the axle from the front to the rear of the vehicle, starting from 1 to n. n is the total number of axles of the vehicle.

[0115] If the front of the vehicle is higher than the rear of the vehicle relative to the selected road surface, is a positive number, the front of the vehicle is lower than the rear of the vehicle relative to the selected road surface. If it is a negative number, the front of the vehicle is neither higher nor lower than the rear of the vehicle relative to the selected road surface. is 0. If the left side of the vehicle is higher than the right side relative to the selected road surface, is a positive number, the left side of the vehicle is lower than the right side relative to the selected road surface. If it is a negative number, the left side of the vehicle is not higher or lower than the right side relative to the selected road surface. is 0.

[0116] Furthermore, the operator sets the target attitude of the vehicle adjustment as required and obtains the target attitude data. The setting method is that when the suspension height is adjusted in place, the target pitch angle of the vehicle is set to The angle between the target side of the vehicle and .

[0117] >0 means the target position of the front of the vehicle is higher than the target position of the rear of the vehicle relative to the selected road surface. 0 means that the target position of the front of the vehicle is lower than the target position of the rear of the vehicle relative to the selected road surface. =0 means that the target position of the front of the vehicle is neither higher nor lower than the target position of the rear of the vehicle relative to the selected road surface.

[0118] >0 means the target position on the left side of the vehicle is higher than the target position on the right side relative to the selected road surface. 0 means that the target position on the left side of the vehicle is lower than the target position on the right side relative to the selected road surface. =0 means that the target position on the left side of the vehicle is neither higher nor lower than the target position on the right side relative to the selected road surface.

[0119] =0 and =0, the vehicle target position is adjusted to be parallel to the selected road surface.

[0120] Furthermore, or , then adjust to the target pitch angle No. The suspension on the right or left side of the axle is raised. or This means that the target pitch angle is adjusted. No. The axis should maintain its current position, or This means that the pitch angle is adjusted to the target No. The suspension on the right or left side of the axle is lowered.

[0121] like , it means that the inclination angle is adjusted to the target side Need to The set target can only be achieved by lifting the suspension on the left side of the axle. , it means that the inclination angle is adjusted to the target side Need to The suspension on the left side of the axle maintains the current position. , it means that the inclination angle is adjusted to the target side Need to The set target can only be achieved by lowering the suspension on the left side of the axle.

[0122] In a preferred embodiment, when the pitch angle between the vehicle X-direction and the road surface is adjusted to the target pitch angle, and the lateral inclination angle between the vehicle Y-direction and the road surface is adjusted to the target lateral inclination angle, the total theoretical adjustment height of each suspension caused by the change in vehicle posture is calculated using the following formula (3):

[0123] (3)

[0124] in, Indicates the first The total theoretical adjusted height of the suspension on the right side of the axle. Indicates the first Theoretical total adjusted height of the suspension on the left side of the axle.

[0125] In this embodiment, the pitch angle between the vehicle X direction and the road surface is calculated and adjusted to the target pitch angle The lateral inclination angle between the vehicle Y direction and the road surface is adjusted to the target lateral inclination angle The total value of the theoretical height adjustment of each suspension, including the total height adjustment of the right suspension Total height adjustment of the left suspension .

[0126] In a preferred embodiment, when the pitch angle between the vehicle X-direction and the road surface is adjusted to the target pitch angle, and the lateral inclination angle between the vehicle Y-direction and the road surface is adjusted to the target lateral inclination angle, the theoretical target height of each suspension is calculated using the following formula (4):

[0127] (4)

[0128] in, Indicates the vehicle's Theoretical target height for the suspension on the right side of the axle. Indicates the vehicle's Theoretical target height for the suspension on the left side of the axle.

[0129] In this embodiment, the theoretical target height that each suspension on both sides of all axles of the vehicle can be adjusted to is calculated.

[0130] In a preferred embodiment, the suspension upper and lower travel limit values ​​include a suspension upper travel limit value when the suspension is adjusted upward and a suspension lower travel limit value when the suspension is adjusted downward.

[0131] Combine the theoretical maximum value, theoretical minimum value, and suspension upper and lower travel limit values ​​to obtain the actual target height of the suspension on both sides of all axles, and adjust the height of each suspension according to the actual target height. The specific steps are as follows:

[0132] A first difference between a theoretical maximum value and an upper suspension travel limit value, and a second difference between a lower suspension travel limit value and a theoretical minimum value are calculated respectively.

[0133] When both the first difference and the second difference are positive numbers, the theoretical target height is compressed until both the first difference and the second difference are not positive numbers.

[0134] When the first difference is not positive and the second difference is positive, if the absolute value of the first difference is not less than the absolute value of the second difference, the absolute value of the second difference is added to the theoretical target height to obtain the actual target height; if the absolute value of the first difference is less than the absolute value of the second difference, the actual target height adopts the smaller of the suspension travel limit value or the theoretical target height plus the absolute value of the second difference.

[0135] When the first difference is positive and the second difference is not positive, if the absolute value of the first difference is not greater than the absolute value of the second difference, the actual target height is obtained by subtracting the absolute value of the first difference from the theoretical target height; if the absolute value of the first difference is greater than the absolute value of the second difference, the actual target height adopts the larger of the suspension travel limit value or the value obtained by subtracting the absolute value of the first difference from the theoretical target height.

[0136] When both the first difference and the second difference are not positive numbers, the theoretical target height is used as the actual target height, and the height of each suspension is adjusted according to the actual target height.

[0137] In this embodiment, the theoretical maximum value and the theoretical minimum value are calculated using the following formula (5):

[0138] (5)

[0139] in, Indicates The theoretical target height of the right suspension of the axle is Theoretical target height of the right suspension of the axle and Theoretical target height of the left suspension of the axle to Maximum of the theoretical target heights for the suspension on the left side of the axle. Indicates The theoretical target height of the right suspension of the axle is Theoretical target height of the right suspension of the axle and Theoretical target height of the left suspension of the axle to Minimum of the theoretical target heights for the suspension on the left side of the axle. .

[0140] Furthermore, the following formula (6) is used to calculate the difference between the maximum and minimum values ​​of the theoretical leveling height and the upper and lower travel limit values ​​of the suspension:

[0141] (6)

[0142] in, Indicates the maximum ground clearance allowed by the suspension, i.e. the upper travel limit of the suspension. Indicates the minimum ground clearance allowed by the suspension, i.e. the suspension lower travel limit. and The difference. and The difference. and Determined by the mechanical characteristics of the suspension system.

[0143] In a preferred embodiment, in the first difference ( ) and the second difference ( When both the first difference and the second difference are positive numbers, the theoretical target height is compressed until both the first difference and the second difference are not positive numbers.

[0144] The vehicle’s Selection factor for suspension on the right side of the axle:

[0145] (7)

[0146] in, Indicates vehicle Selection factor for the suspension on the right side of the axle. Indicates the vehicle's Target height of the suspension on the right side of the axle.

[0147] The vehicle’s Selection factor for suspension on the left side of the axle:

[0148] (8)

[0149] in, Indicates vehicle Selection factor for the suspension on the left side of the axle. Indicates the vehicle's Target height of the suspension on the left side of the axle.

[0150] The actual adjustment height of the suspension on both sides of all axles is calculated using the following formula (9):

[0151] (9)

[0152] in, Indicates vehicle Actual target height of the suspension on the right side of the axle. Indicates vehicle Actual target height of the suspension on the left side of the axle.

[0153] In this embodiment, the first difference and the second difference are both positive numbers, which means that the maximum value of the theoretical adjustment heights of all suspensions exceeds the upper travel limit value of the suspension when the suspension is adjusted upward, and the minimum value of the theoretical adjustment heights of all suspensions exceeds the lower travel limit value of the suspension when the suspension is adjusted downward. It is necessary to proportionally compress the theoretical adjustment heights of all suspensions to avoid the theoretical maximum value exceeding the upper travel limit value of the suspension and the theoretical minimum value exceeding the lower travel limit value of the suspension, so that the height adjustment amount of the suspension is within the acceptable range of the suspension structure.

[0154] In a preferred embodiment, in the first difference ( ) is not positive, and the second difference ( When is positive, there are two cases. One is that the absolute value of the first difference is not less than the absolute value of the second difference (| ), the other is that the absolute value of the first difference is less than the absolute value of the second difference (| ).

[0155] When the absolute value of the first difference is not less than the absolute value of the second difference (| ), the actual target height of the suspension on both sides of all axles is calculated using the following formula (10):

[0156] (10)

[0157] in, Indicates vehicle Actual target height of the suspension on the right side of the axle. Indicates vehicle Actual target height of the suspension on the left side of the axle.

[0158] When the absolute value of the first difference is less than the absolute value of the second difference, the actual target height of the suspension on both sides of all axles is calculated using the following formula:

[0159] (11)

[0160] in, Indicates vehicle Actual target height of the suspension on the right side of the axle. Indicates vehicle Actual target height of the suspension on the left side of the axle.

[0161] In an embodiment, if the first difference is not positive and the second difference is positive, it means that the maximum value of the theoretical adjustment heights of all suspensions does not exceed the upper travel limit of the suspension when the suspension is adjusted upward, but the minimum value of the theoretical adjustment heights of all suspensions exceeds the lower travel limit of the suspension when the suspension is adjusted downward, and the theoretical adjustment heights of all suspensions need to be raised as a whole.

[0162] When lifting as a whole, there are two situations:

[0163] If the absolute value of the first difference is not less than the absolute value of the second difference, it means that the distance between the maximum value in the theoretical adjustment height and the upper travel limit of the suspension is greater than the distance between the minimum value in the theoretical adjustment height and the lower travel limit of the suspension. Until the minimum value in the theoretical adjustment height is raised to the position of the lower travel limit of the suspension, the maximum value in the theoretical adjustment height will not exceed the upper travel limit of the suspension. The lifting amount at this time is the absolute value of the second difference. Therefore, for this situation, the actual target height of all right-side suspensions should be based on the theoretical target height plus the lifting amount, that is, formula (10) should be used.

[0164] If the absolute value of the first difference is smaller than the absolute value of the second difference, it means that the distance between the maximum value in the theoretical adjustment height and the upper travel limit of the suspension is smaller than the distance between the minimum value in the theoretical adjustment height and the lower travel limit of the suspension. Before the minimum value in the theoretical adjustment height is raised to the position of the lower travel limit of the suspension, the maximum value in the theoretical adjustment height will reach or even exceed the upper travel limit of the suspension. The lifting amount at this time is smaller than the second difference. Therefore, in this case, if the lifting amount of a certain suspension adopts the second difference, and the maximum value in the theoretical adjustment height does not exceed the upper travel limit of the suspension, then the actual target height of the suspension is selected by adding the second difference to the theoretical target height. If the lifting amount of a certain suspension adopts the second difference, and the maximum value in the theoretical adjustment height exceeds the upper travel limit of the suspension, then the actual target height of the suspension is selected by the upper travel limit of the suspension. That is, the above formula (11) is used to calculate the actual target heights of the left and right suspensions.

[0165] In a preferred embodiment, when the first difference is positive ( ), and the second difference is not positive ( There are two cases: one is that the absolute value of the first difference is not greater than the absolute value of the second difference (| ), the other is that the absolute value of the first difference is greater than the absolute value of the second difference (| ).

[0166] When the absolute value of the first difference is not greater than the absolute value of the second difference, the actual target height of the suspension on both sides of all axles is calculated using the following formula (12):

[0167] (12)

[0168] in, Indicates vehicle Actual target height of the suspension on the right side of the axle. Indicates vehicle Actual target height of the suspension on the left side of the axle.

[0169] When the absolute value of the first difference is greater than the absolute value of the second difference (| ), the actual target height of the suspension on both sides of all axles is calculated using the following formula (13):

[0170] (13)

[0171] in, Indicates vehicle Actual target height of the suspension on the right side of the axle. Indicates vehicle Actual target height of the suspension on the left side of the axle.

[0172] In this embodiment, if the first difference is positive and the second difference is not positive, it means that the maximum value of the theoretical adjustment heights of all suspensions exceeds the upper travel limit value of the suspension when the suspension is adjusted upward, and the minimum value of the theoretical adjustment heights of all suspensions does not exceed the lower travel limit value of the suspension when the suspension is adjusted downward. Therefore, the theoretical adjustment heights of all suspensions need to be adjusted downward as a whole.

[0173] When the overall adjustment is reduced, it can be divided into two situations:

[0174] If the absolute value of the first difference is not greater than the absolute value of the second difference, it means that the distance between the maximum value in the theoretical adjustment height and the upper travel limit of the suspension is not greater than the distance between the minimum value in the theoretical adjustment height and the lower travel limit of the suspension. Until the maximum value in the theoretical adjustment height is adjusted down to the position of the upper travel limit of the suspension, the minimum value in the theoretical adjustment height will not exceed the lower travel limit of the suspension. The downward adjustment amount at this time is the first difference. Therefore, for this situation, the actual target height of all right-side suspensions should be subtracted from the downward adjustment amount based on the theoretical target height, that is, formula (12) should be used.

[0175] If the absolute value of the first difference is greater than the absolute value of the second difference, it means that the distance between the maximum value in the theoretical adjustment height and the upper travel limit of the suspension is greater than the distance between the minimum value in the theoretical adjustment height and the lower travel limit of the suspension. Before the maximum value in the theoretical adjustment height is adjusted down to the position of the upper travel limit of the suspension, the minimum value in the theoretical adjustment height will reach or even exceed the lower travel limit of the suspension. The downward amount at this time is smaller than the first difference. Therefore, in this case, if the downward adjustment amount of a certain suspension adopts the first difference, and the minimum value in the theoretical adjustment height does not exceed the lower travel limit of the suspension, then the actual target height of the suspension is selected by subtracting the first difference from the theoretical target height. If the downward adjustment amount of a certain suspension adopts the absolute value of the first difference, and the minimum value in the theoretical adjustment height exceeds the lower travel limit of the suspension, then the actual target height of the suspension is selected as the lower travel limit of the suspension, that is, the above formula (13) is used to calculate the actual target heights of the left and right suspensions.

[0176] In a preferred embodiment, in the first difference ( ) and the second difference ( ) are not positive numbers, the theoretical target height is used as the actual target height, and the height of each suspension is adjusted according to the actual target height. The actual target height of the suspension on both sides of all axles is calculated using the following formula (14):

[0177] (14)

[0178] in, Indicates vehicle Actual target height of the suspension on the right side of the axle. Indicates vehicle Actual target height of the suspension on the left side of the axle.

[0179] In this embodiment, if the first difference is not positive and the second difference is not positive, it means that the maximum value of the theoretical adjustment heights of all suspensions does not exceed the upper travel limit value of the suspension when the suspension is adjusted upward, and the minimum value of the theoretical adjustment heights of all suspensions does not exceed the lower travel limit value of the suspension when the suspension is adjusted downward. There is no need to adjust the theoretical adjustment heights of all suspensions, and the theoretical target height is directly used as the actual target height, that is, formula (14) is used.

[0180] The present application is not limited to the above-mentioned implementation modes. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications are also considered to be within the scope of protection of the present application.

Claims

1. A multi-axis vehicle suspension control method, characterized in that: The method comprises: Collecting the current posture data of the vehicle and the target posture data set by the user; the current posture data includes the current ground clearance of the suspensions on both sides of all axles, the current pitch angle between the vehicle X-direction and the road surface, and the current lateral inclination angle between the vehicle Y-direction and the road surface; the target posture data includes the target pitch angle between the vehicle X-direction and the road surface and the target lateral inclination angle between the vehicle Y-direction and the road surface; the road surface is the road surface in contact with any wheel; Calculating respectively the theoretical adjustment height and the theoretical target height of the suspension on both sides of all axles of the vehicle when the vehicle is adjusted to the target pitch angle and the target lateral tilt angle; the theoretical target height is the sum of the current ground clearance of the suspension and the theoretical adjustment height; Extracting a theoretical maximum value and a theoretical minimum value from the theoretical target heights of all suspensions, combining the theoretical maximum value, the theoretical minimum value, and the suspension upper and lower travel limit values, to obtain the actual target heights of the suspensions on both sides of all axles, and adjusting the height of each suspension according to the actual target height, wherein the actual target height does not exceed the suspension upper and lower travel limit values; The suspension upper and lower travel limit values ​​include the suspension upper travel limit value when the suspension is adjusted upward and the suspension lower travel limit value when the suspension is adjusted downward; The actual target height of the suspensions on both sides of all axles is obtained by combining the theoretical maximum value, the theoretical minimum value, and the suspension upper and lower travel limit values, and the height of each suspension is adjusted according to the actual target height. The specific steps are as follows: respectively calculating a first difference between a theoretical maximum value and an upper suspension travel limit value, and a second difference between a lower suspension travel limit value and a theoretical minimum value; When both the first difference and the second difference are positive numbers, the theoretical target height is compressed until both the first difference and the second difference are not positive numbers; When the first difference is positive and the second difference is positive, the vehicle's Selection factor for suspension on the right side of the axle: in, Indicates vehicle Selection factor for the suspension on the right side of the axle; Indicates the vehicle's Target height of suspension on the right side of the axle; Indicates the travel limit value of the suspension; Indicates the suspension lower travel limit value; When the first difference is positive and the second difference is positive, the vehicle's Selection factor for suspension on the left side of the axle: in, Indicates vehicle Selection factor for the suspension on the left side of the axle; Indicates the vehicle's Target height of suspension on the left side of the axle; The actual adjustment height of the suspension on both sides of all axles is calculated using the following formula: in, Indicates vehicle Actual target height of the suspension on the right side of the axle; Indicates vehicle Actual target height of the suspension on the left side of the axle.

2. The multi-axle vehicle suspension control method according to claim 1, characterized in that: The theoretical adjustment height of the suspension on both sides of all axles caused by the change in the pitch angle between the vehicle X-direction and the road surface is calculated using the following formula: in, It means that when the pitch angle between the vehicle X direction and the road surface is adjusted to the target pitch angle, Theoretical adjustment height of the suspension on the right side of the axle; It means that when the pitch angle between the vehicle X direction and the road surface is adjusted to the target pitch angle, Theoretical adjustment height of the suspension on the left side of the axle; i represents the axis sequence from the front to the rear of the vehicle; Indicates the vehicle's The wheelbase from axle to the nth axle; n represents the total number of axles of the vehicle; represents the pitch angle of the target; Indicates the current pitch angle.

3. The multi-axle vehicle suspension control method according to claim 1, characterized in that: The theoretical adjustment height of the suspension on both sides of all axles due to the change in the lateral inclination angle between the vehicle in the Y direction and the road surface is calculated using the following formula: in, Indicates that when the lateral inclination angle between the vehicle Y direction and the road surface is adjusted to the target lateral inclination angle, Theoretical adjustment height of the suspension on the right side of the axle; Indicates that when the lateral inclination angle between the vehicle Y direction and the road surface is adjusted to the target lateral inclination angle, Theoretical adjustment height of the suspension on the left side of the axle; Indicates the vehicle's Track width of the axle; represents the target side inclination angle; Indicates the current side inclination angle.

4. The multi-axle vehicle suspension control method according to claim 1, characterized in that: When the pitch angle between the vehicle X-direction and the road surface is adjusted to the target pitch angle, and the lateral inclination angle between the vehicle Y-direction and the road surface is adjusted to the target lateral inclination angle, the total theoretical adjustment height of each suspension caused by the change in vehicle posture is calculated using the following formula: in, Indicates the first The total theoretical adjusted height of the suspension on the right side of the axle; Indicates the first The total theoretical adjustment height of the suspension on the left side of the axle; It means that when the pitch angle between the vehicle X direction and the road surface is adjusted to the target pitch angle, Theoretical adjustment height of the suspension on the right side of the axle; It means that when the pitch angle between the vehicle X direction and the road surface is adjusted to the target pitch angle, Theoretical adjustment height of the suspension on the left side of the axle; Indicates that when the lateral inclination angle between the vehicle Y direction and the road surface is adjusted to the target lateral inclination angle, Theoretical adjustment height of the suspension on the right side of the axle; Indicates that when the lateral inclination angle between the vehicle Y direction and the road surface is adjusted to the target lateral inclination angle, Theoretical adjusted height of the suspension on the left side of the axle.

5. The multi-axle vehicle suspension control method according to claim 1, characterized in that: When the pitch angle between the vehicle X-direction and the road surface is adjusted to the target pitch angle, and the lateral inclination angle between the vehicle Y-direction and the road surface is adjusted to the target lateral inclination angle, the theoretical target height of each suspension of the vehicle is calculated using the following formula: in, Indicates the vehicle's Theoretical target height of the suspension on the right side of the axle; Indicates the vehicle's Theoretical target height of the suspension on the left side of the axle; Indicates the vehicle Current ground clearance of the suspension on the right side of the axle; Indicates the vehicle Current ground clearance of the suspension on the left side of the axle; Indicates the first The total theoretical adjusted height of the suspension on the right side of the axle; Indicates the first Theoretical total adjusted height of the suspension on the left side of the axle.

6. The multi-axle vehicle suspension control method according to claim 1, characterized in that: When the first difference is not positive and the second difference is positive, if the absolute value of the first difference is not less than the absolute value of the second difference, the absolute value of the second difference is added to the theoretical target height to obtain the actual target height; If the absolute value of the first difference is smaller than the absolute value of the second difference, the actual target height adopts the smaller one of the suspension travel limit value and the value obtained by adding the absolute value of the second difference to the theoretical target height; When the first difference is positive and the second difference is not positive, if the absolute value of the first difference is not greater than the absolute value of the second difference, the absolute value of the first difference is subtracted from the theoretical target height to obtain the actual target height; if the absolute value of the first difference is greater than the absolute value of the second difference, the actual target height adopts the larger value of the suspension lower travel limit value and the value obtained by subtracting the absolute value of the first difference from the theoretical target height; When both the first difference and the second difference are not positive numbers, the theoretical target height is used as the actual target height, and the height of each suspension is adjusted according to the actual target height.

7. The multi-axle vehicle suspension control method according to claim 6, characterized in that: When the first difference is not positive and the second difference is positive, the specific content of the calculation strategy is as follows: When the absolute value of the first difference is not less than the absolute value of the second difference, the actual target height of the suspension on both sides of all axles is calculated using the following formula: in, Indicates vehicle Actual target height of the suspension on the right side of the axle; Indicates vehicle Actual target height of the suspension on the left side of the axle; Indicates the vehicle's Theoretical target height of the suspension on the right side of the axle; Indicates the vehicle's Theoretical target height of the suspension on the left side of the axle; A second difference between the suspension lower travel limit value and the theoretical minimum value; When the absolute value of the first difference is less than the absolute value of the second difference, the actual target height of the suspension on both sides of all axles is calculated using the following formula: in, Indicates the suspension travel limit value.

8. The multi-axle vehicle suspension control method according to claim 6, characterized in that: When the first difference is positive and the second difference is not positive, the specific content of the calculation strategy is as follows: When the absolute value of the first difference is not greater than the absolute value of the second difference, the actual target height of the suspension on both sides of all axles is calculated using the following formula: in, Indicates vehicle Actual target height of the suspension on the right side of the axle; Indicates vehicle Actual target height of the suspension on the left side of the axle; Indicates the vehicle's Target height of suspension on the right side of the axle; Indicates the vehicle's Target height of suspension on the left side of the axle; represents a first difference between the maximum value and the suspension upper travel limit value; When the absolute value of the first difference is greater than the absolute value of the second difference, the actual target height of the suspension on both sides of all axles is calculated using the following formula: in, Indicates the suspension lower travel limit value.

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