Automobile turning control method and system based on electric suspension system

Abstract

The present invention relates to a vehicle turning control method and system based on an electric suspension system. The method specifically comprises the following steps: S1: During a first turning phase, the compression damping of the electronically controlled shock absorber located outside the turning radius is increased, while the extension damping of the electronically controlled shock absorber located inside the turning radius is reduced; S2: During a second turning phase, the compression damping of the electronically controlled shock absorber located outside the turning radius and the extension damping of the electronically controlled shock absorber located inside the turning radius are adjusted based on vehicle speed and lateral acceleration; S3: During a third turning phase, the compression damping of the electronically controlled shock absorber located outside the turning radius is reduced, while the damping of the electronically controlled shock absorber located inside the turning radius is increased. The present invention suppresses changes in the vehicle body roll angle, maintains a stable vehicle posture, improves tire adhesion, reduces sideslip angles, and enhances vehicle handling stability and comfort throughout the entire process of turning, cornering, or lane changing.

Description

Technical Field

[0001] The present invention relates to the field of automobile electronic control technology, and in particular to electronically controlled suspension technology. Background Art

[0002] In recent years, the development of electronic control technology has driven continuous improvements in various automotive performance indicators, gradually evolving cars from traditional modes of transportation into interactive, intelligent mobility tools. This has led to higher demands for vehicle comfort and handling stability. Consequently, active and semi-active control technologies have been adopted in suspension systems, which are crucial to performance. These technologies enable vehicles to proactively adjust performance parameters based on road and vehicle information during driving, achieving optimal ride quality.

[0003] When a vehicle encounters an obstacle ahead, overtakes, or turns during driving, it will enter a short circular motion when turning to avoid obstacles or driving around a curve. The car has a centripetal force pointing to the center of the circle, while the passengers will have an obvious reverse inertial force. The posture of the entire vehicle changes rapidly and gradually tilts toward the outside of the turning radius. The inner compartment tends to be "lifted". In extreme cases, it may even cause the inner wheels to leave the ground and the outer wheels to tilt in the opposite direction of the lateral force of the ground, resulting in a rollover accident.

[0004] When a car changes lanes or turns sharply, if the lateral acceleration exceeds a certain limit, the vertical reaction force on the inside wheel will be zero, causing the car to roll over. Another situation is when the car slips sideways while driving and collides with a road obstacle, causing it to "stumble" and roll over. Generally, to ensure good handling stability during cornering, it is necessary to keep the outside wheel, which bears the majority of the vertical load, perpendicular to the ground as much as possible, ensuring good contact between the tire tread and the ground and sufficient tire adhesion. At the same time, if the vehicle's body posture can be actively adjusted according to the driving conditions to minimize changes in body roll or roll angle, it can provide good passenger comfort and handling stability. Summary of the Invention

[0005] One of the purposes of the present invention is to provide a vehicle turning control method based on an electric suspension system to solve the problem in the prior art that vehicles are prone to rollover when turning; the second purpose is to provide a vehicle turning control system based on an electric suspension system.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A vehicle turning control method based on an electric suspension system, the method specifically comprising:

[0008] Obtain signal parameters and determine the steering scenario;

[0009] If the steering scene is determined to be the first turning phase when the angular velocity of the steering wheel is greater than or equal to the first angular velocity threshold and the lateral acceleration is greater than or equal to the first lateral acceleration threshold, the compression damping of the electronically controlled shock absorber located outside the turning radius is increased, and the extension damping of the electronically controlled shock absorber located inside the turning radius is reduced;

[0010] If the angular velocity of the steering wheel is less than or equal to a second angular velocity threshold and the lateral acceleration is greater than or equal to a second lateral acceleration threshold, the steering scenario is determined to be the second turning phase, then based on the vehicle speed and the lateral acceleration, the compression damping of the electronically controlled shock absorber located outside the turning radius and the extension damping of the electronically controlled shock absorber located inside the turning radius are adjusted, such that the compression damping of the electronically controlled shock absorber located outside the turning radius remains greater than the compression damping before the first turning phase, and the extension damping of the electronically controlled shock absorber located outside the turning radius remains less than the extension damping before the first turning phase;

[0011] When the angular velocity of the steering wheel is greater than or equal to the third angular velocity threshold, the lateral acceleration is less than or equal to the third lateral acceleration threshold, and the ADAS system obtains the road markings of the straight road, the steering scenario is determined to be the third turning stage, the compression damping of the electronically controlled shock absorber located outside the turning radius decreases, and the tensile damping located inside the turning radius increases until the compression damping of the electronically controlled shock absorber located outside the turning radius is equal to the compression damping of the electronically controlled shock absorber located inside the turning radius.

[0012] Furthermore, if the angular velocity of the steering wheel is greater than or equal to a fourth angular velocity threshold and the ADAS system obtains road markings of the curve, the height and stiffness of the air spring located outside the turning radius are increased, and the height and stiffness of the air spring located inside the turning radius are reduced. The height of the air spring located outside the turning radius is greater than the height of the air spring located inside the turning radius, and the stiffness of the air spring located outside the turning radius is greater than the stiffness of the air spring located inside the turning radius.

[0013] Furthermore, during the first turning stage, the height and stiffness of the air spring located outside the turning radius are increased, and the height and stiffness of the air spring located inside the turning radius are reduced.

[0014] Furthermore, in the second turning stage, compared with the first turning stage, the height and stiffness of the air spring outside the turning radius and the height and stiffness of the air spring inside the turning radius are kept unchanged.

[0015] Furthermore, during the third turning stage, the height and stiffness of the air spring located outside the turning radius are reduced, and the height and stiffness of the air spring located inside the turning radius are increased, until the height of the air spring located outside the turning radius is equal to the height of the air spring inside the turning radius and the stiffness of the air spring located outside the turning radius is equal to the stiffness of the air spring inside the turning radius.

[0016] Furthermore, when the angular velocity of the steering wheel is greater than or equal to the fifth angular velocity threshold, the lateral acceleration is greater than or equal to the fourth lateral acceleration threshold, and the ADAS system obtains road markings or roadblock information on the curve, it enters the sharp turn stage. When entering the sharp turn stage, the compression damping of the electronically controlled shock absorber on the outside of the turning radius increases, and the tensile damping of the electronically controlled shock absorber on the inside of the turning radius decreases.

[0017] Furthermore, when entering a sharp turn, the increase in compression damping of the electronically controlled shock absorber on the outside of the turning radius and the decrease in tension damping of the electronically controlled shock absorber on the inside of the turning radius are both related to the vehicle speed and the steering wheel angular velocity.

[0018] Furthermore, the change in the height of the air spring is related to the vehicle speed and the lateral acceleration, and the change in the stiffness of the air spring is related to the vehicle speed and the lateral acceleration.

[0019] An automobile turning control system based on an electric suspension system according to the above method is characterized by comprising: a judgment module configured to judge a state, wherein the state is in a pre-turning stage, a first turning stage, a second turning stage, a third turning stage, or a sharp turning stage;

[0020] When the angular velocity of the steering wheel is greater than or equal to a fourth angular velocity threshold and the ADAS system obtains a road surface marking of a curve, the judgment module determines that the vehicle is in a pre-turning stage;

[0021] When the angular velocity of the steering wheel is greater than or equal to a first angular velocity threshold and the lateral acceleration is greater than or equal to a first lateral acceleration threshold, the judgment module determines that the vehicle is in the first turning stage;

[0022] When the angular velocity of the steering wheel is less than or equal to the second angular velocity threshold and the lateral acceleration is greater than or equal to the second lateral acceleration threshold, the judgment module determines that the vehicle is in the second turning stage;

[0023] When the angular velocity of the steering wheel is greater than or equal to a third angular velocity threshold, the lateral acceleration is less than or equal to a third lateral acceleration threshold, and the ADAS system obtains a road marking of a straight road, the judgment module determines that the vehicle is in the third turning stage;

[0024] When the angular velocity of the steering wheel is greater than or equal to a fifth angular velocity threshold, the lateral acceleration is greater than or equal to a fourth lateral acceleration threshold, and the ADAS system obtains road markings or roadblock information of the curve, the judgment module determines that the vehicle is in a sharp turn phase;

[0025] a control module configured to, when in a pre-turning phase, increase the height and stiffness of an air spring located outside a turning radius and decrease the height and stiffness of an air spring located inside the turning radius, wherein the height of the air spring located outside the turning radius is greater than the height of the air spring located inside the turning radius, and the stiffness of the air spring located outside the turning radius is greater than the stiffness of the air spring located inside the turning radius;

[0026] In the first turning stage, the control module increases the compression damping of the electronically controlled shock absorber located outside the turning radius and reduces the extension damping of the electronically controlled shock absorber located inside the turning radius;

[0027] In the second turning phase, the control module adjusts the compression damping of the electronically controlled shock absorber located outside the turning radius and the extension damping of the electronically controlled shock absorber located inside the turning radius based on the vehicle speed, lateral acceleration, and steering wheel angle, so that the compression damping of the electronically controlled shock absorber located outside the turning radius remains greater than the compression damping in the pre-turning phase, and the extension damping of the electronically controlled shock absorber located outside the turning radius remains less than the extension damping in the pre-turning phase.

[0028] When in the third turning stage, the control module reduces the compression damping of the electronically controlled shock absorber located outside the turning radius and increases the extension damping of the electronically controlled shock absorber located inside the turning radius until the compression damping of the electronically controlled shock absorber located outside the turning radius is equal to the compression damping of the electronically controlled shock absorber located inside the turning radius;

[0029] When in a sharp turn, the control module increases the compression damping of the electronically controlled shock absorber on the outside of the turning radius and reduces the extension damping of the electronically controlled shock absorber on the inside of the turning radius.

[0030] Furthermore, when in the first turning stage, the control module increases the height and stiffness of the air spring located outside the turning radius and decreases the height and stiffness of the air spring located inside the turning radius; when in the second turning stage, the control module maintains the height and stiffness of the air spring outside the turning radius and the height and stiffness of the air spring inside the turning radius unchanged;

[0031] When in the third turning stage, the control module reduces the height and stiffness of the air spring located outside the turning radius and increases the height and stiffness of the air spring located inside the turning radius until the height of the air spring located outside the turning radius is equal to the height of the air spring inside the turning radius and the stiffness of the air spring located outside the turning radius is equal to the stiffness of the air spring inside the turning radius.

[0032] Beneficial effects of the present invention:

[0033] Before the vehicle turns, the stiffness and length of the air springs along the outside and inside of the turning radius are controlled, so that the vehicle body enters the state of slightly higher and larger air spring stiffness on the outside and slightly lower and smaller air spring stiffness on the inside in advance. When starting to turn, the compression damping of the vehicle along the outside of the turning radius is increased and the tension damping on the inside is reduced. During the steering process, the performance of the electronically controlled shock absorber and the air spring are continued to be adjusted in real time according to the vehicle working conditions. In the steering return phase, the parameters of the electronically controlled shock absorber and air spring along the inside and outside of the turning radius of the vehicle are adjusted back. During emergency steering, the compression damping of the vehicle along the outside of the turning radius is increased and the tension damping inside is reduced. During the entire process of turning, cornering, and changing lanes, the vehicle body roll angle change is suppressed, the body posture is kept stable, the tire adhesion is improved, the sideslip angle is reduced, and the vehicle's handling stability and comfort are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a flow chart of the electronically controlled suspension control method of the present invention;

[0035] Figure 2 This is a specific flow chart of the electronically controlled suspension control method of the present invention;

[0036] Figure 3 A vehicle equipped with an electronically controlled suspension including an electronically controlled shock absorber and an air spring as disclosed in the present invention;

[0037] Figure 4 Schematic diagram of a car turning control system based on an electric suspension system.

[0038] Among them, 1-the car's CAN bus; 2-the electronically controlled suspension controller; 3-the left front wheel, 4-the right front wheel; 5-the left rear wheel; 6-the right rear wheel; 31-the left front electronically controlled shock absorber, 32-the left front air spring, 41-the right front electronically controlled shock absorber, 42-the right front air spring, 51-the left rear electronically controlled shock absorber, 52-the left rear air spring, 61-the right rear electronically controlled shock absorber, 62-the right rear air spring; 7-the judgment module; 8-the control module. DETAILED DESCRIPTION

[0039] The following will describe the implementation of the technical solution of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for the purpose of illustrating the present invention and are not intended to limit the scope of protection of the present invention.

[0040] It should be noted that the illustrations provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0041] This embodiment proposes a vehicle turning control method based on an electric suspension system. Figure 1 As shown, it is first necessary to determine which stage of the turn is in. In this embodiment, the turning state is divided into a pre-turning stage, a first turning stage, a second turning stage, a third turning stage and a sharp turning stage, wherein the pre-turning stage, the first turning stage, the second turning stage and the third turning stage are performed in sequence. The first turning stage represents the start of the turn, the second turning stage represents the turning in progress, and the third turning stage represents the return stage.

[0042] When the "pre-turn" control is triggered, the electronic suspension's advance steering control function is entered, which is also an active steering control function. The control system will adjust the air spring height or stiffness in advance according to the current vehicle body posture, electronic suspension performance parameters, and road conditions, thereby reducing the outward tilt of the vehicle body along the turning radius when turning, increasing the vertical load on the outer wheels, reducing the sideslip angle change, and improving adhesion.

[0043] When the "start-turn" control is triggered, the electronically controlled suspension enters the steering control function, which is also the control for entering a curve. The control system adjusts the damping of the electronically controlled shock absorber and continues to maintain and adjust the air spring height based on the "pre-turn" control to suppress changes in the body roll angle and keep the body posture stable.

[0044] When the "mid-turn" control is triggered, the electronic suspension stable steering process control begins. At this time, the vehicle will smoothly pass through the curve at a stable speed, lateral acceleration or steering wheel angle. The control system will continue to adjust the damping of the electronic shock absorber according to the real-time working conditions of the vehicle, and adjust the air spring height based on the "start-turn" control to suppress the change of the body roll angle and ensure the stability of the body posture.

[0045] When the "return to center" control is triggered, the electronically controlled suspension steering returns to center, which is also the control for turning into straight driving. The control system adjusts the damping of the electronically controlled shock absorber and adjusts the air spring height based on the "turn-in-progress" control to suppress changes in the body roll angle, ensure a stable body posture, balance the vertical load areas of the wheels inside and outside the turning radius, reduce changes in the sideslip angle, and improve tire adhesion.

[0046] When the "sharp turn" control is triggered, the electronically controlled suspension enters emergency steering control, which is also a control function for rapid turning and lane changing and overtaking. The control system adjusts the damping of the electronically controlled shock absorber, increases the vertical load on the wheels along the outer side of the turning radius, reduces the change in the sideslip angle, suppresses the change in the body roll angle, and ensures a stable body posture.

[0047] Step 0: When the electronically controlled suspension's "pre-rotation" control is triggered, based on the vehicle's speed, longitudinal acceleration signal, and road signs and curve information acquired and recognized by the ADAS system, the air springs on the outside of the turning radius are controlled to increase stiffness and raise the vehicle's height. Simultaneously, the air springs on the inside of the turning radius are controlled to decrease stiffness and lower the vehicle's height. This adjusts the vehicle's posture to a state where it is slightly higher on the outside of the turning radius and slightly lower on the inside before turning.

[0048] The lifting height of the outer air spring is the same as the lowering height of the inner air spring, and the changes in the height and stiffness of the inner and outer air springs are positively correlated with the changes in vehicle speed and longitudinal acceleration.

[0049] Step 1: When the electronically controlled suspension's "start of turn" (entering the first turning phase) is triggered, the air spring stiffness on the outside of the turning radius increases, raising the vehicle's height, while the air spring stiffness on the inside decreases, lowering the vehicle's height. This increases the compression damping of the shock absorber on the outside of the turning radius, while decreasing the extension damping of the shock absorber on the inside. This suppresses changes in the body roll angle, ensures a stable body posture, and increases the vertical load on the outside wheels, improving adhesion and minimizing changes in the sideslip angle.

[0050] The increase in compression damping of the electronically controlled shock absorbers along the outer edge of the turning radius is related to vehicle speed and lateral acceleration, while the decrease in extension damping of the electronically controlled shock absorbers along the outer edge is also related to vehicle speed and lateral acceleration. The air spring stiffness and lift height outside the turning radius are also related to vehicle speed and lateral acceleration, while the air spring stiffness and lift height inside the turning radius are also related to vehicle speed and lateral acceleration.

[0051] Step 2: When the electronically controlled suspension's "mid-turn" control (entering the second turning phase) is triggered, based on vehicle speed, lateral acceleration, and steering wheel angle, and in addition to "start-of-turn" control, the system maintains the air spring stiffness and height along the inside and outside of the turning radius, increases the compression damping of the shock absorber along the outside of the turning radius, and adjusts the tension damping of the shock absorber on the inside. Compensatory adjustments are also made based on vehicle speed and steering wheel angle. This suppresses changes in body roll angle and ensures a stable vehicle posture.

[0052] The air spring stiffness and height are positively correlated with vehicle speed, lateral angular velocity and steering wheel angle changes, while the electronically controlled shock absorber damping is positively correlated with vehicle speed, lateral angular velocity and steering wheel angle changes.

[0053] Step 3: When the electronically controlled suspension's "return to center" control (entering the third turning phase) is triggered, based on the vehicle's speed and longitudinal acceleration signals, as well as road signs and curve information recognized in advance by the ADAS system, the vehicle's air spring stiffness on the inside of the turning radius is increased, raising the vehicle's height. The air spring stiffness on the outside of the turning radius is reduced, lowering the vehicle's height. The compression damping of the shock absorber on the outside of the turning radius is reduced, while the extension damping of the shock absorber on the inside is increased. This suppresses changes in the body roll angle, ensures a stable body posture, and gradually equalizes the vertical loads on the inside and outside wheels.

[0054] The reduction in compression damping of the electronically controlled shock absorber along the outer side of the turning radius is related to vehicle speed and longitudinal acceleration, while the increase in extension damping of the electronically controlled shock absorber on the inner side is related to vehicle speed and lateral acceleration. The reduction in compression damping of the outer electronically controlled shock absorber is the same as the increase in extension damping of the inner electronically controlled shock absorber, and gradually tends to the inner and outer electronically controlled shock absorbers having the same compression damping.

[0055] The increase in air spring stiffness and height increase on the inside of the turning radius are related to vehicle speed and longitudinal acceleration, while the decrease in air spring stiffness and height reduction on the outside are related to vehicle speed and lateral acceleration. The increase in air spring stiffness and height increase on the inside and the decrease in air spring stiffness and height reduction on the outside gradually tend to have the same stiffness and height on the inside and outside air springs.

[0056] If the "sharp turn" control of the electronic suspension is triggered, the compression damping of the electronically controlled shock absorber on the outside of the turning radius will be increased and the tension damping of the electronically controlled shock absorber on the inside will be reduced according to the vehicle speed and steering wheel angular velocity, so as to increase the vertical load on the outer wheel, reduce the change in the sideslip angle, and suppress the change in the body roll angle.

[0057] The increase in compression damping of the electronically controlled shock absorber along the outer side of the turning radius is related to the vehicle speed and steering wheel angular velocity, while the decrease in tension damping of the outer electronically controlled shock absorber is related to the vehicle speed and steering wheel angular velocity.

[0058] The control method for judging whether to trigger pre-rotation, start-rotation, mid-rotation, return to center, or rapid rotation is as follows:

[0059] Determine whether to trigger "pre-turn" control based on the vehicle's steering wheel angular velocity signal, road signs and curve information recognized in advance by the ADAS system, and system thresholds;

[0060] The system determines whether to trigger the "start-turn" control based on the vehicle's lateral acceleration, steering wheel angular velocity, and system thresholds. When the steering wheel angular velocity and lateral angular velocity reach the system thresholds, the control system confirms the triggering of the "start-turn" control.

[0061] The system determines whether to trigger the "turn-to-center" control based on the vehicle's lateral acceleration, steering wheel angle, and system thresholds. When the lateral acceleration and steering wheel angle reach the system thresholds, the control system confirms the triggering of the "turn-to-center" control.

[0062] Determine whether to trigger "return to center" control based on the vehicle's lateral acceleration and steering wheel angular velocity, road signs and curve information recognized in advance by the ADAS system, and system thresholds;

[0063] The vehicle's ADAS system identifies road surface information, roadblock information, steering wheel angular velocity, lateral acceleration and system thresholds to determine whether to trigger "sudden turn" control.

[0064] Specifically, ADAS can identify road markings and curve information, allowing the vehicle to obtain the driving road surface in advance and pre-identify the need for steering operations. When the ADAS system identifies a turn sign or curve on the road ahead, combined with the steering wheel angular velocity reaching the fourth angular velocity threshold, the vehicle speed is only used to control the current size. The vehicle speed and the control current are directly proportional to confirm the triggering of "pre-turn" control;

[0065] When the angular velocity of the steering wheel is greater than or equal to a first angular velocity threshold and the lateral acceleration is greater than or equal to a first lateral acceleration threshold, confirming that the "start turning" control is triggered;

[0066] When the angular velocity of the steering wheel is less than or equal to the second angular velocity threshold and the lateral acceleration is greater than or equal to the second lateral acceleration threshold, confirming that the "turn-in" control is triggered;

[0067] When the steering wheel's angular velocity is greater than or equal to the third angular velocity threshold, the lateral acceleration is less than or equal to the third lateral acceleration threshold, and the ADAS system detects a straight road marking, the "return to center" control is triggered.

[0068] When the angular velocity of the steering wheel is greater than or equal to the fifth angular velocity threshold, the lateral acceleration is greater than or equal to the fourth lateral acceleration threshold, and the ADAS system obtains road markings or roadblock information on the curve, the system confirms the triggering of the "sharp turn" control.

[0069] Among them, the first angular velocity threshold and the first lateral acceleration threshold, the second angular velocity threshold and the second lateral acceleration threshold, the third angular velocity threshold and the third lateral acceleration threshold, the fourth angular velocity threshold and the fourth lateral acceleration threshold, and the fifth angular velocity threshold and the fourth lateral acceleration threshold respectively refer to characteristic parameters of the vehicle entering the initial turn, mid-turn, return to center, pre-turn, and sudden turn control functions.

[0070] For example, as shown in the following table:

[0071] Table 1 Parameter examples

[0072]

[0073] Figure 3 The vehicle with an electronically controlled suspension equipped with electronically controlled shock absorbers and air springs involved in the patent of the present invention includes a control system signal source 1, namely the vehicle's CAN bus, an electronically controlled suspension controller 2, 3-left front wheel, 4-right front wheel; 5-left rear wheel; 6-right rear wheel, a left front electronically controlled shock absorber 31, a left front air spring 32, a left rear electronically controlled shock absorber 51, a left rear air spring 52, a right front electronically controlled shock absorber 41, a right front air spring 42, a right rear electronically controlled shock absorber 61, and a right rear air spring 62.

[0074] Reference Figure 2 , a specific flow chart of the electronically controlled suspension control method of the present invention, the above method specifically includes:

[0075] In step S201, the control system receives vehicle signal parameters and determines the steering scenario.

[0076] In step S202, the control system receives the steering wheel angular velocity signal and the road sign and curve information pre-identified by the ADAS system. Based on the acquired signal, the control system determines whether the vehicle will subsequently turn. In this embodiment, the pre-set steering wheel angular velocity threshold must meet the steering wheel angular velocity range for the electronically controlled suspension's "pre-turn" operating condition, and simultaneously, in conjunction with the road turning sign and curve markings identified by the ADAS system, confirm the initiation of "pre-turn" control. The steering wheel angular velocity threshold can be determined within a range based on actual measurements of daily driving conditions. Turning sign and curve markings are obtained by the ADAS system through road surface information recognition.

[0077] The control process is as follows: For example, when a vehicle equipped with electronically controlled shock absorbers and air springs turns right, the vehicle enters a circular motion centered on the right side of the circle. The distance from the vehicle to the center of the circle is the turning radius, with the right side of the vehicle being the inside of the turning radius and the left side being the outside. The left front electronically controlled shock absorber 31 and the left rear electronically controlled shock absorber 51 are located on the outside of the turning radius, while the right front electronically controlled shock absorber 41 and the right rear electronically controlled shock absorber 61 are located on the inside of the turning radius. The left front air spring 32 and the left rear air spring 52 are located on the outside of the turning radius, while the right front air spring 42 and the right rear air spring 62 are located on the inside of the turning radius.

[0078] In step S203, when the electronic control system enters the "pre-turn" control of turning right, the system controls the left front air spring 32 and the left rear air spring 52 on the outside of the turning radius of the vehicle to increase stiffness and raise height, and the left front air spring 32 and the left rear air spring 52 increase stiffness and height at the same rate; at the same time, the right front air spring 42 and the right rear air spring 62 on the inside of the turning radius of the vehicle are controlled to reduce stiffness and lower height, and the right front air spring 42 and the right rear air spring 52 increase stiffness and height at the same rate; that is, the outer air spring is in a stretched state and the inner air spring is in a compressed state, so that the vehicle adjusts the body posture to a state slightly higher along the outer side of the turning radius and slightly lower along the inner side before turning; the outer air spring raising height is the same as the inner air spring lowering height, and the changes in the height and stiffness of the inner and outer air springs are positively correlated with the square of the vehicle speed and the change in lateral acceleration, that is, the ADAS system can identify the turning radius of the road in advance, and the control system combines the vehicle speed and calculates the value according to the formula The centripetal acceleration of the vehicle's turning circle is determined in advance, equating to the lateral acceleration of the vehicle in a curve. The height and stiffness of the inner and outer air springs are positively correlated with the lateral acceleration. Actual values ​​are obtained through extensive testing on a test vehicle at various speeds and turning radii, using a linear curve fitting the relationship between lateral acceleration and air spring height and stiffness. After "pre-turn" control, the system automatically enters the next steering scenario determination cycle.

[0079] In step S204, the control system receives the lateral acceleration and steering wheel angular velocity at the time of starting to turn, and based on the system's preset "start turning" threshold, when the steering wheel angular velocity and lateral angular velocity reach the system's preset "start turning" threshold, it determines that the vehicle has started to turn and triggers the "start turning" control; in this embodiment, the pre-set steering wheel angular velocity and lateral acceleration thresholds must meet the range values ​​of the time when the electronically controlled suspension starts to turn, and the specific values ​​can be obtained based on actual vehicle measurements.

[0080] In step S205, the control process takes the vehicle equipped with electronically controlled shock absorbers and air springs as an example. The vehicle starts to turn right. The vehicle enters a circular motion with the right center of the circle as the rotation center. Based on the "pre-turn" control, the vehicle enters the "start-turn" control. According to the actual vehicle speed and lateral acceleration, the stiffness of the left front air spring 32 and the left rear air spring 52 on the outside of the turning radius of the vehicle is increased, and the height is increased. The stiffness of the right front air spring 42 and the right rear air spring 62 on the inside is reduced, and the height is reduced. The compression damping of the left front electronically controlled shock absorber 31 and the left rear electronically controlled shock absorber 51 on the outside of the turning radius is increased, and the tension damping of the right front electronically controlled shock absorber 41 and the right rear electronically controlled shock absorber 61 on the inside of the turning radius is reduced. This suppresses the change in the body roll angle, ensures the stability of the body posture, increases the vertical load on the outer wheel, improves the adhesion, and reduces the change in the sideslip angle.

[0081] The increase in compression damping for electronically controlled shock absorbers 31 and 51 along the outer edge of the turning radius is positively correlated with vehicle speed and lateral acceleration, while the decrease in tension damping for right front electronic shock absorber 41 and right rear electronic shock absorber 61 is positively correlated with vehicle speed and lateral acceleration. The stiffness and lift height of the left front air spring 32 and left rear air spring 52 are positively correlated with vehicle speed and lateral acceleration, while the stiffness and lift height of the right front air spring 42 and right rear air spring 62 are positively correlated with vehicle speed and lateral acceleration. After the "start turn" control, the system automatically enters the next turning scenario determination cycle.

[0082] In step S206, the control system receives the vehicle's lateral acceleration and steering wheel angle during the turn or steering process, along with a preset "mid-turn" threshold, and determines whether to trigger mid-turn control. When the lateral acceleration and steering wheel angle reach the system threshold, the control system confirms the triggering of mid-turn control. The preset steering wheel angle and lateral acceleration thresholds must fall within the range of values ​​used during the electronically controlled suspension's steering process, which can be determined by the vehicle undergoing various turns or corners.

[0083] In step S207, the vehicle enters circular motion centered on the right side of the circle. During this process, the vehicle briefly undergoes stable steering. Based on vehicle speed and lateral acceleration, the control system maintains the stiffness and height of the left front air spring 32, left rear air spring 52, right front air spring 42, and right rear air spring 62, based on the initial turn. The system also increases compression damping on the left front electronically controlled shock absorber 31 and left rear electronically controlled shock absorber 51 and decreases tension damping on the right front electronically controlled shock absorber 41 and right rear electronically controlled shock absorber 61. Compensatory adjustments are made based on changes in lateral acceleration and speed. This suppresses changes in vehicle roll angle and ensures a stable vehicle posture. The air spring stiffness and height are positively correlated with vehicle speed and lateral angular velocity, and the electronically controlled shock absorber damping is positively correlated with vehicle speed and lateral angular velocity. After the mid-turn control, the system automatically enters the next steering scenario determination loop.

[0084] In step S208, the control system receives the vehicle's steering wheel angular velocity signal, the road sign and curve information previously identified by the ADAS system, and determines whether the vehicle will subsequently return to the normal state based on the acquired signal. In this embodiment, the pre-set steering wheel angular velocity threshold must meet the steering wheel angular velocity range value for the "return to normal" condition of the electronically controlled suspension, and at the same time, in combination with the road sign markings, curves, or straight road markings identified by the ADAS system, confirm the start of the "return to normal" control. The steering wheel angular velocity threshold can be obtained from a range based on actual measurements of daily driving conditions. Road sign markings, curves, or straight road markings are obtained by the ADAS system through road surface information recognition.

[0085] Step S209 is a specific control process. According to the vehicle speed and lateral acceleration signal in the return phase, the stiffness of the right front air spring 42 and the right rear air spring 62 of the vehicle is increased and the height is raised, the stiffness of the left front air spring 32 and the left rear air spring 52 is reduced and the height is lowered, the compression damping of the left front electronically controlled shock absorber 31 and the left rear electronically controlled shock absorber 51 is reduced, and the extension damping of the right front electronically controlled shock absorber 41 and the right rear electronically controlled shock absorber 61 is increased to suppress the change in the roll angle of the vehicle body. The system ensures a stable vehicle posture and gradually equalizes the vertical loads on the inner and outer wheels. The reduction in compression damping of the left front electronic shock absorber 31 and the left rear electronic shock absorber 51 is positively correlated with vehicle speed and lateral acceleration, while the increase in extension damping of the right front electronic shock absorber 41 and the right rear electronic shock absorber 61 is related to vehicle speed and lateral acceleration. The reduction in compression damping of the outer electronic shock absorber is the same as the increase in extension damping of the inner electronic shock absorber, and the damping of the inner and outer electronic shock absorbers gradually equalizes. The increase in air spring stiffness and height increase on the inner side of the turning radius are positively correlated with vehicle speed and lateral acceleration, while the decrease in air spring stiffness and height reduction on the outer side are related to vehicle speed and lateral acceleration. The increase in air spring stiffness and height increase on the inner side equalizes the decrease in air spring stiffness and height reduction on the outer side, gradually aligning the inner and outer air springs to have the same stiffness and height. After "returning to center" control, the system automatically enters the next steering scenario determination cycle.

[0086] In step S210, the control system determines whether to trigger a "sharp turn" control based on the vehicle's ADAS system's identification of the roadblock ahead, the steering wheel angular velocity, the lateral acceleration, and the system's preset "sharp turn" threshold. The control system triggers the "sharp turn" control when the steering wheel angular velocity or lateral acceleration reaches the system's "sharp turn" threshold. The "sharp turn" threshold can be determined within a range based on actual measurements of the vehicle under a "sharp turn" condition.

[0087] Step S211 specifically controls the damping of the electronically controlled suspension's electronically controlled shock absorbers when "sharp turn" control is triggered. Based on the vehicle speed and lateral acceleration at the time of the sudden turn, the compression damping of the left front electronically controlled shock absorber 31 and the left rear electronically controlled shock absorber 51 is increased, while the extension damping of the right front electronically controlled shock absorber 41 and the right rear electronically controlled shock absorber 61 is reduced. This increases the vertical load on the outer wheels, reduces the sideslip angle, and suppresses changes in the vehicle body roll angle. The increase in compression damping of the left front electronically controlled shock absorber 31 and the left rear electronically controlled shock absorber 51 is positively correlated with vehicle speed and lateral acceleration, while the decrease in extension damping of the right front electronically controlled shock absorber 41 and the right rear electronically controlled shock absorber 61 is positively correlated with vehicle speed and lateral acceleration. The increase in compression damping of the left front electronically controlled shock absorber 31 and the left rear electronically controlled shock absorber 51 is the same as the decrease in extension damping of the right front electronically controlled shock absorber 41 and the right rear electronically controlled shock absorber 61. The actual specific change value can be obtained by testing the vehicle in a sharp turn condition.

[0088] The control method of the electronically controlled suspension according to the patent of the present invention can improve the comfort and handling stability of the vehicle during the entire steering process.

[0089] The embodiment of the present invention also provides a vehicle turning control system based on an electric suspension system, such as Figure 4 As shown, its main components are:

[0090] The judgment module 7 is used to select and judge whether to trigger the pre-rotation, start-rotation, mid-rotation, return to normal, and rapid rotation control functions;

[0091] When the electronically controlled suspension's "pre-rotation" control is triggered, the air spring stiffness and height are controlled, adjusting the vehicle body to a slightly higher position on the outside of the turning radius and slightly lower on the inside before the vehicle turns. This suppresses the vehicle body's outward tilt angle during cornering, increases the vertical load on the outside wheels, and reduces the change in sideslip angle.

[0092] When the electronic suspension "start-to-rotate" control is triggered, the electronic shock absorber damping, air spring stiffness and height continue to be adjusted and controlled on the basis of "pre-rotation", thereby suppressing the change in the body roll angle and keeping the body stable.

[0093] When the "mid-turn" control of the electronic suspension is triggered, the control system adjusts the damping of the electronic shock absorber and adjusts the height of the air spring based on the "start-turn" control to suppress changes in the body roll angle and maintain the stability of the body.

[0094] When the "return to center" control of the electronic suspension is triggered, the control system adjusts the damping of the electronic shock absorber and adjusts the air spring height in reverse based on the "centering" control to suppress changes in the body roll angle and ensure a stable body posture.

[0095] When the "sharp turn" control of the electronic suspension is triggered, the control system adjusts the damping of the electronic shock absorber, increases the vertical load on the wheels along the outer side of the turning radius, reduces the change in the sideslip angle, suppresses the change in the body roll angle, and keeps the body posture stable.

[0096] When the "pre-rotation" control of the electronically controlled suspension is triggered, the air springs along the outside of the turning radius of the vehicle are controlled to increase stiffness and raise height according to the vehicle's speed, longitudinal acceleration signal and road signs and curve information recognized by the ADAS system. At the same time, the air springs on the inside of the turning radius of the vehicle are controlled to reduce stiffness and lower height. Before turning, the vehicle's body posture is adjusted to a state that is slightly higher along the outside of the turning radius and slightly lower on the inside. The increased height of the outer air spring is the same as the lowered height of the inner air spring, and the changes in height and stiffness of the inner and outer air springs are positively correlated with changes in vehicle speed and longitudinal acceleration.

[0097] When the electronically controlled suspension's "start-to-turn" control is triggered, the air spring rate increases and the vehicle's height is raised on the outside of the turning radius, while the air spring rate decreases and the vehicle's height is lowered on the inside, based on vehicle speed and lateral acceleration. This increases the compression damping of the shock absorbers on the outside of the turning radius and decreases the extension damping on the inside, suppressing changes in vehicle roll angle and ensuring vehicle stability. This also increases the vertical load on the outside wheels, improving adhesion and minimizing slip angle changes. The increase in compression damping on the outside of the turning radius is related to vehicle speed and lateral acceleration, while the decrease in extension damping on the outside of the turning radius is also related to vehicle speed and lateral acceleration. The air spring rate and height increase on the outside of the turning radius are also related to vehicle speed and lateral acceleration, while the air spring rate and height increase on the inside of the turning radius are also related to vehicle speed and lateral acceleration.

[0098] When the electronically controlled suspension's "mid-turn" control is triggered, based on vehicle speed, lateral acceleration, and steering wheel angle, and in addition to "start-turn" control, the system maintains the air spring stiffness and height along the inside and outside of the turning radius, increases shock absorber compression damping along the outside of the turning radius, and increases shock absorber extension damping on the inside. Compensatory adjustments are also made based on vehicle speed and steering wheel angle. This suppresses changes in body roll angle and maintains a stable vehicle stance. The air spring stiffness and height are positively correlated with changes in vehicle speed, lateral angular velocity, and steering wheel angle, while the electronically controlled shock absorber damping is positively correlated with changes in vehicle speed, lateral angular velocity, and steering wheel angle.

[0099] When the electronic suspension's "return to center" control is triggered, the vehicle's air spring stiffness along the inside of the turning radius is increased, and the height is raised, while the air spring stiffness and height are reduced on the outside, based on the vehicle's speed and longitudinal acceleration signals, as well as road signs and curve information recognized in advance by the ADAS system. This reduces the compression damping of the shock absorber on the outside of the turning radius and increases the extension damping of the shock absorber on the inside, thereby suppressing changes in the body roll angle and ensuring a stable body posture, gradually aligning the vertical loads on the inside and outside wheels. The reduction in the compression damping of the electronic shock absorber along the outside of the turning radius is related to the vehicle speed and longitudinal acceleration, while the increase in the extension damping of the electronic shock absorber on the inside is related to the vehicle speed and lateral acceleration. The reduction in the compression damping of the electronic shock absorber on the outside of the turning radius is the same as the increase in the extension damping of the electronic shock absorber on the inside, and the process gradually progresses to the point where the compression damping of the inner and outer electronic shock absorbers is the same. The increase in air spring stiffness and height increase on the inside of the turning radius are related to vehicle speed and longitudinal acceleration, while the decrease in air spring stiffness and height reduction on the outside are related to vehicle speed and lateral acceleration. The increase in air spring stiffness and height increase on the inside and the decrease in air spring stiffness and height reduction on the outside gradually tend to have the same stiffness and height on the inside and outside air springs.

[0100] When the electronic suspension's "sharp turn" control is triggered, the electronically controlled shock absorbers on the outside of the turning radius are adjusted to increase compression damping and decrease tension damping on the inside, based on vehicle speed and steering wheel angular velocity. This increases the vertical load on the outside wheels, reduces slip angle changes, and suppresses changes in body roll. The increase in compression damping on the outside of the turning radius is related to vehicle speed and steering wheel angular velocity, while the decrease in tension damping on the outside is also related to vehicle speed and steering wheel angular velocity.

[0101] The control module 8 is:

[0102] Whether to trigger "pre-turn" control is determined based on the vehicle's steering wheel angular velocity signal, the road signs and curve information obtained and identified in advance by the ADAS system, and the system threshold; ADAS can identify road signs and curve information, so that the vehicle can obtain the road surface in advance and pre-identify the need for steering operations. When the ADAS system recognizes that there are turning signs or curves on the road ahead, combined with the steering wheel angular velocity reaching the fourth angular velocity threshold, it is confirmed that the "pre-turn" control is triggered, and the electronic control system begins to adjust the electronic control based on the vehicle speed and acceleration.

[0103] Based on the vehicle's lateral acceleration and steering wheel angular velocity, it is determined whether to trigger the "start turn" control; when the steering wheel angular velocity and lateral angular velocity reach a first angular velocity threshold and a first lateral acceleration threshold, the control system confirms that the "start turn" control is triggered.

[0104] Based on the vehicle's lateral acceleration, steering wheel angle and system threshold, it is determined whether to trigger the "turn to center" control; when the lateral acceleration and steering wheel angle reach the second angular velocity threshold and the lateral acceleration reaches the second lateral acceleration threshold, the control system confirms that the "turn to center" control is triggered.

[0105] The system determines whether to trigger the "return to center" control based on the vehicle's lateral acceleration and steering wheel angular velocity, the road signs and curve information recognized in advance by the ADAS system, and the system threshold. When the ADAS system recognizes that the road ahead is about to enter a straight route, the steering wheel's angular velocity reaches the third angular velocity threshold and the lateral acceleration reaches the third lateral acceleration threshold, the control system confirms the triggering of the "return to center" control.

[0106] The vehicle ADAS system identifies road obstacle information, steering wheel angular velocity, lateral acceleration and system thresholds to determine whether to trigger the "sudden turn" control; when the steering wheel angular velocity reaches the fifth angular velocity threshold and the lateral acceleration reaches the fourth lateral acceleration threshold, the control system confirms the triggering of the "sudden turn" control.

[0107] In this embodiment, a turning control system based on an electric suspension system controls the vehicle's electronically controlled shock absorbers and air springs to implement the control method of the present invention. Specifically, before the vehicle turns, the stiffness and damping of the air springs on the outside and inside of the turning radius are controlled, causing the vehicle body to enter a state where the outer air springs are slightly stiffer and stiffer, while the inner air springs are slightly stiffer and stiffer. At the start of the turn, the compression damping on the outside of the turning radius is increased, while the extension damping on the inside is reduced. During the turn, the performance of the electronically controlled shock absorbers and air springs is continuously adjusted in real time based on the vehicle's operating conditions. During the steering return phase, the electronically controlled shock absorbers and air spring parameters on the inside and outside of the turning radius are adjusted. During emergency turns, the compression damping on the outside of the turning radius is increased, while the extension damping on the inside is reduced. This effectively suppresses changes in the vehicle's roll angle and maintains a stable body posture throughout the entire process of turning, cornering, or lane changing. This also helps improve tire adhesion, reduce slip angles, and enhance handling stability and comfort during turns.

[0108] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. A vehicle turning control method based on an electric suspension system, characterized by: The method is specifically as follows: Obtain signal parameters and determine the steering scenario; If the steering wheel angular velocity is greater than or equal to a first angular velocity threshold and the lateral acceleration is greater than or equal to a first lateral acceleration threshold, the steering scenario is determined to be the first turning phase, and the compression damping of the electronically controlled shock absorber located outside the turning radius is increased, while the extension damping of the electronically controlled shock absorber located inside the turning radius is reduced; If the angular velocity of the steering wheel is less than or equal to a second angular velocity threshold and the lateral acceleration is greater than or equal to a second lateral acceleration threshold, the steering scenario is determined to be the second turning phase, then based on the vehicle speed and the lateral acceleration, the compression damping of the electronically controlled shock absorber located outside the turning radius and the extension damping of the electronically controlled shock absorber located inside the turning radius are adjusted, such that the compression damping of the electronically controlled shock absorber located outside the turning radius remains greater than the compression damping before the first turning phase, and the extension damping of the electronically controlled shock absorber located outside the turning radius remains less than the extension damping before the first turning phase; When the angular velocity of the steering wheel is greater than or equal to the third angular velocity threshold, the lateral acceleration is less than or equal to the third lateral acceleration threshold, and the ADAS system obtains the road markings of the straight road, the steering scenario is determined to be the third turning stage, the compression damping of the electronically controlled shock absorber located outside the turning radius decreases, and the tensile damping located inside the turning radius increases until the compression damping of the electronically controlled shock absorber located outside the turning radius is equal to the compression damping of the electronically controlled shock absorber located inside the turning radius.

2. The method according to claim 1, wherein: If the angular velocity of the steering wheel is greater than or equal to the fourth angular velocity threshold and the ADAS system obtains the road surface markings of the curve, the height and stiffness of the air spring located outside the turning radius are increased, and the height and stiffness of the air spring located inside the turning radius are reduced. The height of the air spring located outside the turning radius is greater than the height of the air spring located inside the turning radius, and the stiffness of the air spring located outside the turning radius is greater than the stiffness of the air spring located inside the turning radius.

3. The method according to claim 2, wherein: During the first turning stage, the height and stiffness of the air spring located outside the turning radius are increased, and the height and stiffness of the air spring located inside the turning radius are reduced.

4. The method according to claim 2, wherein: During the second turning stage, compared with the first turning stage, the height and stiffness of the air spring outside the turning radius and the height and stiffness of the air spring inside the turning radius are kept unchanged.

5. The method according to claim 2, wherein: During the third turning stage, the height and stiffness of the air spring located outside the turning radius are reduced, and the height and stiffness of the air spring located inside the turning radius are increased until the height of the air spring located outside the turning radius is equal to the height of the air spring inside the turning radius and the stiffness of the air spring located outside the turning radius is equal to the stiffness of the air spring inside the turning radius.

6. The method according to claim 1, wherein: When the angular velocity of the steering wheel is greater than or equal to the fifth angular velocity threshold, the lateral acceleration is greater than or equal to the fourth lateral acceleration threshold, and the ADAS system obtains road markings or roadblock information on the curve, it enters the sharp turn stage. When entering the sharp turn stage, the compression damping of the electronically controlled shock absorber on the outside of the turning radius increases, and the tensile damping of the electronically controlled shock absorber on the inside of the turning radius decreases.

7. The method according to claim 6, characterized in that: When entering the sharp turning stage, the increase in compression damping of the electronically controlled shock absorber on the outside of the turning radius and the decrease in tension damping of the electronically controlled shock absorber on the inside of the turning radius are both related to the vehicle speed and steering wheel angular velocity.

8. The method according to any one of claims 2 to 5, characterized in that: The change in height of the air spring is related to vehicle speed and lateral acceleration, and the change in stiffness of the air spring is related to vehicle speed and lateral acceleration.

9. A vehicle turning control system based on an electric suspension system according to any one of claims 1 to 8, characterized in that: comprising a judgment module configured to judge a state, wherein the state is in a pre-turning stage, a first turning stage, a second turning stage, a third turning stage, or a sharp turning stage; When the angular velocity of the steering wheel is greater than or equal to a fourth angular velocity threshold and the ADAS system obtains a road surface marking of a curve, the judgment module determines that the vehicle is in a pre-turning stage; When the angular velocity of the steering wheel is greater than or equal to a first angular velocity threshold and the lateral acceleration is greater than or equal to a first lateral acceleration threshold, the judgment module determines that the vehicle is in the first turning stage; When the angular velocity of the steering wheel is less than or equal to the second angular velocity threshold and the lateral acceleration is greater than or equal to the second lateral acceleration threshold, the judgment module determines that the vehicle is in the second turning stage; When the angular velocity of the steering wheel is greater than or equal to a third angular velocity threshold, the lateral acceleration is less than or equal to a third lateral acceleration threshold, and the ADAS system obtains a road marking of a straight road, the judgment module determines that the vehicle is in the third turning stage; When the angular velocity of the steering wheel is greater than or equal to a fifth angular velocity threshold, the lateral acceleration is greater than or equal to a fourth lateral acceleration threshold, and the ADAS system obtains road markings or roadblock information of the curve, the judgment module determines that the vehicle is in a sharp turn phase; a control module configured to, when in a pre-turning phase, increase the height and stiffness of an air spring located outside a turning radius and decrease the height and stiffness of an air spring located inside the turning radius, wherein the height of the air spring located outside the turning radius is greater than the height of the air spring located inside the turning radius, and the stiffness of the air spring located outside the turning radius is greater than the stiffness of the air spring located inside the turning radius; In the first turning stage, the control module increases the compression damping of the electronically controlled shock absorber located outside the turning radius and reduces the extension damping of the electronically controlled shock absorber located inside the turning radius; In the second turning phase, the control module adjusts the compression damping of the electronically controlled shock absorber located outside the turning radius and the extension damping of the electronically controlled shock absorber located inside the turning radius based on the vehicle speed, lateral acceleration, and steering wheel angle, so that the compression damping of the electronically controlled shock absorber located outside the turning radius remains greater than the compression damping in the pre-turning phase, and the extension damping of the electronically controlled shock absorber located outside the turning radius remains less than the extension damping in the pre-turning phase. When in the third turning stage, the control module reduces the compression damping of the electronically controlled shock absorber located outside the turning radius and increases the extension damping of the electronically controlled shock absorber located inside the turning radius until the compression damping of the electronically controlled shock absorber located outside the turning radius is equal to the compression damping of the electronically controlled shock absorber located inside the turning radius; When in a sharp turn, the control module increases the compression damping of the electronically controlled shock absorber on the outside of the turning radius and reduces the extension damping of the electronically controlled shock absorber on the inside of the turning radius.

10. The control system according to claim 9, characterized in that: When in the first turning stage, the control module increases the height and stiffness of the air spring located outside the turning radius and decreases the height and stiffness of the air spring located inside the turning radius; when in the second turning stage, the control module maintains the height and stiffness of the air spring outside the turning radius and the height and stiffness of the air spring inside the turning radius unchanged; When in the third turning stage, the control module reduces the height and stiffness of the air spring located outside the turning radius and increases the height and stiffness of the air spring located inside the turning radius until the height of the air spring located outside the turning radius is equal to the height of the air spring inside the turning radius and the stiffness of the air spring located outside the turning radius is equal to the stiffness of the air spring inside the turning radius.

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