Vehicle attitude control device and method

Abstract

The invention provides a vehicle attitude control device and method, and relates to the technical field of vehicle control. The device comprises the steps that a brake-by-wire system collects the wheel speed of each wheel of a vehicle and obtains attitude data, deviation calculation is conducted on the attitude data and the wheel speeds, an attitude deviation value is obtained, and the vehicle state of the vehicle is matched from a stability degree table according to the attitude deviation value; the air suspension system collects suspension height signals of all wheels of the vehicle, when the brake-by-wire system judges that the state of the vehicle is an unstable state, the suspension height signals of all the wheels are adjusted according to adjusting rules, and height adjusting signals corresponding to all the wheels are obtained; the air suspension system adjusts the height of the air spring of the corresponding wheel according to the plurality of height adjustment signals. The vehicle is jointly controlled through the brake-by-wire system and the air suspension system, the height of an air spring of the vehicle is adjusted, the vehicle is prevented from rolling over due to the unstable gravity center, and the safety of the vehicle is improved.

Description

Technical Field

[0001] The present invention mainly relates to the field of vehicle control technology, and in particular to a vehicle posture control device and method. Background Art

[0002] The vehicle's air suspension system adjusts the hardness of the air spring by controlling the air compressor to charge and discharge air. When the car is driving on an uneven road, the body can be raised to facilitate passing. When driving at high speed on a good road, the body can be lowered to lower the center of gravity and improve handling stability. However, the air suspension system adjusts the center of gravity of the vehicle when driving on different road conditions. This is only based on the predicted suspension height of each wheel, and then adjusts the air spring, which often ignores the situation where the vehicle oversteers or skews and causes the vehicle to roll over. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a vehicle posture control device and method in view of the deficiencies in the prior art.

[0004] The technical solution of the present invention to solve the above technical problems is as follows:

[0005] A vehicle posture control device, comprising:

[0006] A brake-by-wire system, for collecting wheel speeds of each wheel of the vehicle, and acquiring posture data, and performing deviation calculation on the posture data and a plurality of the wheel speeds to obtain a posture deviation value, and matching the vehicle state from a stability table according to the posture deviation value;

[0007] Air suspension system, used to collect suspension height signals of each wheel of the vehicle;

[0008] The brake-by-wire system is further used to determine whether the vehicle state is an unstable state, and if so, to adjust the suspension height signal of each wheel according to an adjustment rule to obtain a height adjustment signal corresponding to each wheel;

[0009] The air suspension system is also used to adjust the height of the air spring of the corresponding wheel according to the multiple height adjustment signals.

[0010] Another technical solution of the present invention to solve the above technical problems is as follows:

[0011] A vehicle posture control method, comprising:

[0012] The brake-by-wire system collects wheel speeds of each wheel of the vehicle, obtains posture data, and performs deviation calculation on the posture data and a plurality of wheel speeds to obtain a posture deviation value, and matches the vehicle state from a stability table according to the posture deviation value;

[0013] The air suspension system collects suspension height signals of each wheel of the vehicle, and the wire control brake system determines whether the vehicle state is an unstable state. If so, the suspension height signals of each wheel are adjusted according to the adjustment rules to obtain height adjustment signals corresponding to each wheel;

[0014] The air suspension system adjusts the air spring heights of corresponding wheels according to the plurality of height adjustment signals.

[0015] The beneficial effects of the present invention are as follows: during the operation of the vehicle, the brake-by-wire system calculates the vehicle speed and the running posture data of the vehicle to determine whether the vehicle is in a stable state during the operation. If the vehicle is in an unstable state, the suspension height to be adjusted is calculated according to the suspension height collected by the air suspension system, and the air suspension system adjusts the air spring height on the suspension corresponding to each wheel of the vehicle according to the suspension height to be adjusted, thereby avoiding the vehicle from rolling over due to excessive suspension height. Under the premise of not adding a controller to the vehicle, that is, not increasing the cost, the brake-by-wire system and the air suspension system jointly control the vehicle, adjust the height of the air spring of the vehicle, prevent the vehicle from rolling over due to unstable center of gravity, and improve the safety of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A structural diagram of a vehicle posture control device provided by an embodiment of the present invention;

[0017] Figure 2 The present invention provides a flow chart of a vehicle posture control method. DETAILED DESCRIPTION

[0018] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0019] like Figure 1 As shown, a vehicle posture control device provided by an embodiment of the present invention includes:

[0020] A brake-by-wire system, for collecting wheel speeds of each wheel of the vehicle, and acquiring posture data, and performing deviation calculation on the posture data and a plurality of the wheel speeds to obtain a posture deviation value, and matching the vehicle state from a stability table according to the posture deviation value;

[0021] Air suspension system, used to collect suspension height signals of each wheel of the vehicle;

[0022] The brake-by-wire system is further used to determine whether the vehicle state is an unstable state, and if so, to adjust the suspension height signal of each wheel according to an adjustment rule to obtain a height adjustment signal corresponding to each wheel;

[0023] The air suspension system is also used to adjust the height of the air spring of the corresponding wheel according to the multiple height adjustment signals.

[0024] Specifically, after receiving a request (i.e., multiple height adjustment signals), the air spring system (i.e., air suspension system) will control the compressor to pump air, discharge a portion of the air in the air spring cavity, and lower the suspension height to the target height, thereby lowering the center of gravity of the vehicle and improving the overall stability of the vehicle.

[0025] It should be understood that the air spring system is equipped with a suspension height sensor corresponding to each wheel on each of the four wheel sides. Each suspension height sensor is connected to the air spring controller via a hard wire (i.e., a physical wire harness). The air spring controller collects the voltage signal sent by the suspension height sensor. The air spring controller converts the voltage signal on each wheel side into a suspension height signal of the suspension according to the size of the voltage signal. The air spring system can freely adjust the vehicle height within a certain range, using air as a spring medium, and adjusting the spring stiffness and vehicle height by inflation and exhaust, that is, controlling the gas quality in the air spring. The brake-by-wire system is equipped with a wheel speed sensor corresponding to each wheel on each of the four wheel sides. Each wheel speed sensor is connected to the brake-by-wire controller via a hard wire (i.e., a physical wire harness). The brake-by-wire controller receives the wheel speed pulse signal sent by the wheel speed sensor according to a preset pulse frequency, and converts the wheel speed pulse signal on each wheel side into the wheel speed according to the preset pulse frequency.

[0026] The present invention realizes deviation calculation of the posture data and the plurality of wheel speeds through a stability judgment algorithm to obtain a posture deviation value, matches the stable state of the vehicle from a stability table according to the posture deviation value, and deploys the processing steps of the stability judgment algorithm into a linear control system. The height adjustment algorithm is used to determine whether the vehicle state is an unstable state, and if so, adjusts the suspension height signal of each wheel according to the adjustment rule to obtain the height adjustment signal corresponding to each wheel, and deploys the processing steps of the height adjustment algorithm into a linear control system.

[0027] In an embodiment of the present invention, multiple controllers are jointly controlled, and a wire control brake system is used to control and calculate the vehicle's posture data and vehicle speed, providing the air spring system with stability judgment of a large yaw (i.e. oversteer) or lateral deflection state, and calculating the suspension height value to be adjusted based on the stability judgment result, so as to control the air spring system to lower the height of the air spring, thereby lowering the center of gravity of the entire vehicle and preventing the vehicle from rolling over.

[0028] Preferably, the posture data includes steering wheel angle, front wheel angle, lateral acceleration and yaw angular velocity;

[0029] In the brake-by-wire system, performing deviation calculation on the posture data and the plurality of wheel speeds to obtain a posture deviation value includes:

[0030] Calculating the average of the plurality of wheel speeds to obtain a vehicle speed, calculating the ratio of the steering wheel angle to the front wheel angle to obtain a steering ratio, and calculating the vehicle speed and the steering ratio using a yaw angle calculation expression to obtain a desired yaw angular velocity;

[0031] The desired yaw angular velocity, the lateral acceleration and the deflection angular velocity are weighted and calculated respectively to obtain a posture deviation value.

[0032] Preferably, in the brake-by-wire system, weight calculation is performed on the desired yaw angular velocity, the lateral acceleration and the deflection angular velocity respectively to obtain an attitude deviation value, including:

[0033] The yaw angular velocity and the desired yaw angular velocity are difference calculated to obtain an angular velocity difference, the lateral acceleration and the set acceleration are difference calculated to obtain an acceleration difference, and the angular velocity difference and the acceleration difference are weighted according to a set weight coefficient to obtain a posture deviation value.

[0034] Specifically, the wheel speeds of the four wheels are: left front wheel V FL , right front wheel V FR , Left rear wheel V RL and right rear wheel V RR , calculate the average of the four wheel speeds to get the vehicle speed, and the wheel speed average calculation expression is:

[0035] V vehicle =(V FL +V FR +V RL +V RR ) / 4,

[0036] Among them, V vehicle is the vehicle speed, V FL is the left front wheel speed, V FR is the right front wheel speed, V RL is the left rear wheel speed, V RR is the right rear wheel speed;

[0037] The steering ratio is obtained by dividing the steering wheel angle by the front wheel angle. The vehicle speed and the steering ratio are calculated by the yaw angle calculation expression to obtain the desired yaw angular velocity. The yaw angle calculation expression is:

[0038]

[0039] Among them, Yaw Targetis the desired yaw rate (rad / s), V vehicle is the vehicle speed (m / s), Sas is the steering wheel angle, L is the wheelbase (m), SteerRatio is the steering ratio, * is the multiplication operation, and K is the calibration coefficient; the steering wheel angle is collected by the steering wheel angle sensor, the front wheel angle is collected by the steering angle sensor, the wheelbase is the distance from the midpoint of the front wheel axle to the midpoint of the rear wheel axle, and the calibration coefficient is obtained by taking the stable state deflection angular velocity as the expected yaw angular velocity, and substituting the stable state vehicle speed, steering wheel angle, wheelbase and steering ratio into the yaw angle calculation expression when the vehicle is in a stable state.

[0040] If the vehicle is instability in steering, the yaw angular velocity Yaw collected by the sensor and the expected yaw angular velocity Yaw calculated according to the Ackerman equation Target There will be a deviation, the size of which is one of the conditions for judging whether the vehicle is unstable; at the same time, excessive lateral acceleration Ay will also cause vehicle instability, which is also one of the conditions for judging whether the vehicle is unstable. Target ∣(i.e., the deflection angular velocity Yaw and the desired yaw angular velocity Yaw Target When the absolute value obtained by difference is greater than the first threshold, it is judged that there is an instability trend; at the same time, when |Ay-P| (that is, the absolute value obtained by difference between the lateral acceleration Ay and the set acceleration P is greater than the second threshold, it is judged that there is an instability trend. Therefore, according to the size of the two deviation values, the weight coefficient is taken to judge the degree of instability. The larger the deviation, the higher the degree of instability.

[0041] It should be understood that the posture data is obtained by controlling the airbag controller unit (ECU) to send the vehicle lateral acceleration signal Ay, vehicle yaw angular velocity signal Yaw, steering wheel angle signal Sas and front wheel angle collected by the inertial sensor to the wire control brake system through the CAN bus. The CAN bus (Controller Area Network) in the vehicle is a local area network of the controller unit, a serial communication protocol, mainly used for communication between automotive electronic control units. According to the principle of the Ackerman equation, assuming that the vehicle follows the Ackerman steering geometry when turning along the curve, the steering angle of the inner wheel is larger than that of the outer wheel, and the center of the four wheel paths roughly intersects the instantaneous steering center on the extension line of the rear axle, and the yaw angle calculation expression is derived.

[0042] In the embodiment of the present invention, whether the vehicle is in a state of losing stability is determined based on the posture data and speed of the vehicle during operation, so that when the vehicle oversteers and has a large yaw or lateral deviation, the suspension height is adjusted to prevent the vehicle from rolling over.

[0043] Preferably, in the brake-by-wire system, matching the vehicle state of the vehicle from a stability table according to the attitude deviation value comprises:

[0044] The posture deviation value is matched with each difference interval of the stability table to obtain a matching difference interval, and the corresponding vehicle state is found according to the matching difference interval to obtain the vehicle state of the vehicle.

[0045] Specifically, constructing the stability table includes: dividing the deviation intervals corresponding to the multiple posture deviation values, and one deviation interval corresponds to a vehicle state, such as a stable state, a general instability state, and a serious instability state.

[0046] In the embodiment of the present invention, the attitude deviation value is matched with the difference interval to determine whether the vehicle is in a stable state or an unstable state, and then the height of the air suspension is adjusted in an unstable state.

[0047] Preferably, in the brake-by-wire system, adjusting the suspension height signal of each wheel according to an adjustment rule to obtain a height adjustment signal corresponding to each wheel includes:

[0048] The process of adjusting the suspension height signal of any wheel according to the adjustment rule is as follows:

[0049] Matching the vehicle state with each height interval of the height adjustment table to obtain a matching height interval, converting the suspension height signal into a suspension height, respectively calculating the matching degree of each adjustment height in the matching height interval and the suspension height to obtain a plurality of matching degree values, taking the adjustment height corresponding to the largest matching degree value among the plurality of matching degree values ​​as the height adjustment amount, and converting the height adjustment amount into a height adjustment signal;

[0050] In this process, all suspension height signals are adjusted to obtain height adjustment signals corresponding to each wheel.

[0051] Specifically, constructing a height adjustment table includes: dividing the height intervals corresponding to multiple suspension heights, and one height interval corresponds to multiple matching heights. Generally, the suspension height of the vehicle is between 15 cm and 20 cm, and the adjustment range is 0 to 5 cm. The height required to adjust the vehicle in a stable state is set to zero; the height required to adjust the vehicle in a general unstable state is set to 1 cm and 2 cm, that is, the height interval is 1 to 2 cm; the height required to adjust the vehicle in a severe unstable state is set to 3 cm and 5 cm, that is, the height interval is 3 to 5 cm.

[0052] If the vehicle is in a general unstable state and the suspension height is 17 cm, the matching height range is 1 to 2 cm. The matching height is the suspension height minus the height to be adjusted, which is 16 cm and 15 cm respectively. The matching degree of 16 cm and 15 cm is calculated with 17 cm respectively to obtain multiple matching degree values.

[0053] In an embodiment of the present invention, based on the vehicle state determined by the wire control brake system and the suspension height calibration value collected by the air suspension system, if the degree of instability is higher, the target height to which the suspension height is lowered will be greater; if the target height is less than the minimum height of the air spring, a request is made to descend to the minimum height position, i.e., the suspension height is adjusted to the minimum height of the air spring.

[0054] Preferably, in the brake-by-wire system, a matching degree is calculated for each adjustment height in the matching height interval and the suspension height to obtain a plurality of matching degree values, including:

[0055] The process of calculating the matching degree between any adjustment height and the suspension height is as follows:

[0056] Calculating the difference between the suspension height and the adjustment height to obtain a matching height, calculating the vehicle's rollover moment according to the matching height to obtain a matching rollover moment, calculating the vehicle's rollover moment according to the suspension height to obtain an actual rollover moment, and calculating the ratio of the actual rollover moment to the matching rollover moment to obtain a matching degree value;

[0057] In this process, the matching degree between all matching heights and the suspension height is calculated to obtain a plurality of matching degree values.

[0058] Specifically, the matching degree is calculated by combining physical formulas and principles to analyze the vehicle stability improved by lowering the center of gravity. When the vehicle turns, the centrifugal force F is calculated according to the vehicle speed. c , according to the centrifugal force F c The vehicle's center of gravity height h is calculated to obtain the vehicle's overturning moment. c The original center of gravity height h1 (i.e., suspension height) of the vehicle is calculated to obtain the actual tipping moment M1; according to the centrifugal force F c Calculate the vehicle's multiple lowered center of gravity heights h2 (i.e., the height calculated based on the suspension height adjusted height) to obtain multiple matching tipping moments M2; use the change ratio of the tipping moment (i.e., the matching value) to measure whether the vehicle stability is improved after the center of gravity is lowered according to the matching height, that is, select the matching height corresponding to the maximum matching value from each matching value as the height to which the air spring needs to be adjusted. The calculation process includes the following expressions:

[0059]

[0060] Among them, F c is the centrifugal force, v is the vehicle speed, r is the turning radius, and m is the vehicle mass;

[0061] M=F c h,

[0062] Where M is the tipping moment, h is the height of the vehicle's center of gravity;

[0063]

[0064] Among them, M1 is the actual tipping moment, h1 is the suspension height, M2 is the matched tipping moment, and h2 is the matched height;

[0065]

[0066] Among them, G is the change ratio (ie, the matching value).

[0067] It should be understood that when the vehicle turns along a curve, it follows the Ackermann steering geometry, the steering angle of the inner wheel is larger than that of the outer wheel, and the centers of the four wheel paths roughly intersect the instantaneous steering center on the extension line of the rear axle, thereby obtaining the turning radius.

[0068] In the embodiment of the present invention, the overturning moment is calculated for each matching height in the matching height range of the suspension height to calculate whether the adjusted suspension height can keep the vehicle in a stable state, thereby selecting the center of gravity height that makes the vehicle most stable.

[0069] Preferably, in the brake-by-wire system, before the step of adjusting the suspension height signal of each wheel according to the adjustment rule, the system further comprises:

[0070] Creating communication information of a suspension height signal and a height adjustment signal on a CAN bus of the vehicle respectively, and sending the suspension height signal to a brake-by-wire system through the CAN bus based on the communication information of the suspension height signal;

[0071] After the step of obtaining the height adjustment signal corresponding to each wheel, the method further includes:

[0072] The communication information based on the height adjustment signal sends the height adjustment signal corresponding to each wheel to the air suspension system through the CAN bus.

[0073] Specifically, CAN communication has a standard format, and only the complete signal information such as signal address, name, range and accuracy needs to be added to complete the signal addition. For vehicle CAN communication, it is necessary to add an actual height signal of the air spring (i.e., suspension height signal) and a target height request signal (i.e., height adjustment signal). Actual height is used by the IBCU of the brake-by-wire system to determine the actual height of the air spring, and Target height is used by the IBCU of the brake-by-wire system to send a height adjustment request to the air suspension system. After receiving the target height request signal sent by the IBCU of the brake-by-wire system, the air suspension system automatically adjusts the suspension height (i.e., controls the compressor to extract part of the air volume in the air spring cavity to reduce the suspension height to the target height).

[0074] In the embodiment of the present invention, height signal information associated with the air suspension system is added to the CAN bus communication, and then communication is performed through the CAN bus to achieve joint control of the vehicle by multiple controllers of the wire control brake system and the air suspension system.

[0075] like Figure 2 As shown, a vehicle posture control method provided by an embodiment of the present invention includes:

[0076] The brake-by-wire system collects wheel speeds of each wheel of the vehicle, obtains posture data, and performs deviation calculation on the posture data and a plurality of wheel speeds to obtain a posture deviation value, and matches the vehicle state from a stability table according to the posture deviation value;

[0077] The air suspension system collects suspension height signals of each wheel of the vehicle, and the wire control brake system determines whether the vehicle state is an unstable state. If so, the suspension height signals of each wheel are adjusted according to the adjustment rules to obtain height adjustment signals corresponding to each wheel;

[0078] The air suspension system adjusts the air spring heights of corresponding wheels according to the plurality of height adjustment signals.

[0079] The above-mentioned vehicle posture control method can refer to the implementation content and beneficial effects of the vehicle posture control device specifically described above, which will not be repeated here.

[0080] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0081] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices and modules can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0082] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules is only a logical function division, and there may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0083] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the embodiments of the present invention.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A vehicle posture control device, characterized in that: include: A brake-by-wire system, for collecting wheel speeds of each wheel of the vehicle, and acquiring posture data, and performing deviation calculation on the posture data and a plurality of the wheel speeds to obtain a posture deviation value, and matching the vehicle state from a stability table according to the posture deviation value; Air suspension system, used to collect suspension height signals of each wheel of the vehicle; The brake-by-wire system is further used to determine whether the vehicle state is an unstable state, and if so, to adjust the suspension height signal of each wheel according to an adjustment rule to obtain a height adjustment signal corresponding to each wheel; The air suspension system is also used to adjust the height of the air spring of the corresponding wheel according to the multiple height adjustment signals.

2. The vehicle posture control device according to claim 1, characterized in that: The posture data includes steering wheel angle, front wheel angle, lateral acceleration and yaw angular velocity; In the brake-by-wire system, performing deviation calculation on the posture data and the plurality of wheel speeds to obtain a posture deviation value includes: The vehicle speed is obtained by calculating the average of the plurality of wheel speeds, the steering wheel angle and the front wheel angle are ratio-calculated to obtain a steering ratio, the vehicle speed and the steering ratio are calculated by a yaw angle calculation expression to obtain a desired yaw angular velocity, and the desired yaw angular velocity, the lateral acceleration and the yaw angular velocity are weighted to obtain a posture deviation value.

3. The vehicle posture control device according to claim 2, characterized in that: In the brake-by-wire system, weight calculation is performed on the desired yaw angular velocity, the lateral acceleration and the deflection angular velocity to obtain an attitude deviation value, including: The yaw angular velocity and the desired yaw angular velocity are difference calculated to obtain an angular velocity difference, the lateral acceleration and the set acceleration are difference calculated to obtain an acceleration difference, and the angular velocity difference and the acceleration difference are weighted according to a set weight coefficient to obtain a posture deviation value.

4. The vehicle posture control device according to claim 1, characterized in that: In the brake-by-wire system, matching the vehicle state of the vehicle from a stability table according to the attitude deviation value includes: The posture deviation value is matched with each difference interval of the stability table to obtain a matching difference interval, and the corresponding vehicle state is found according to the matching difference interval to obtain the vehicle state of the vehicle.

5. The vehicle posture control device according to claim 1, characterized in that: In the brake-by-wire system, the suspension height signal of each wheel is adjusted according to an adjustment rule to obtain a height adjustment signal corresponding to each wheel, including: The process of adjusting the suspension height signal of any wheel according to the adjustment rule is as follows: Matching the vehicle state with each height interval of the height adjustment table to obtain a matching height interval, converting the suspension height signal into a suspension height, respectively calculating the matching degree of each adjustment height in the matching height interval and the suspension height to obtain a plurality of matching degree values, taking the adjustment height corresponding to the largest matching degree value among the plurality of matching degree values ​​as the height adjustment amount, and converting the height adjustment amount into a height adjustment signal; In this process, all suspension height signals are adjusted to obtain height adjustment signals corresponding to each wheel.

6. The vehicle posture control device according to claim 5, characterized in that: In the brake-by-wire system, a matching degree is calculated for each adjustment height in the matching height interval and the suspension height to obtain a plurality of matching degree values, including: The process of calculating the matching degree between any adjustment height and the suspension height is as follows: Calculating the difference between the suspension height and the adjustment height to obtain a matching height, calculating the vehicle's rollover moment according to the matching height to obtain a matching rollover moment, calculating the vehicle's rollover moment according to the suspension height to obtain an actual rollover moment, and calculating the ratio of the actual rollover moment to the matching rollover moment to obtain a matching degree value; In this process, the matching degree between all matching heights and the suspension height is calculated to obtain a plurality of matching degree values.

7. The vehicle posture control device according to claim 1, characterized in that: In the brake-by-wire system, before the step of adjusting the suspension height signal of each wheel according to the adjustment rule, the method further includes: Creating communication information of a suspension height signal and a height adjustment signal on a CAN bus of the vehicle respectively, and sending the suspension height signal to a brake-by-wire system through the CAN bus based on the communication information of the suspension height signal; After the step of obtaining the height adjustment signal corresponding to each wheel, the method further includes: The communication information based on the height adjustment signal sends the height adjustment signal corresponding to each wheel to the air suspension system through the CAN bus.

8. A vehicle posture control method, characterized in that: include: The brake-by-wire system collects wheel speeds of each wheel of the vehicle, obtains posture data, and performs deviation calculation on the posture data and a plurality of wheel speeds to obtain a posture deviation value, and matches the vehicle state from a stability table according to the posture deviation value; The air suspension system collects suspension height signals of each wheel of the vehicle, and the wire control brake system determines whether the vehicle state is an unstable state. If so, the suspension height signals of each wheel are adjusted according to the adjustment rules to obtain height adjustment signals corresponding to each wheel; The air suspension system adjusts the air spring heights of corresponding wheels according to the plurality of height adjustment signals.

9. The vehicle posture control method according to claim 8, characterized in that: The posture data includes steering wheel angle, front wheel angle, lateral acceleration and yaw angular velocity; The step of performing deviation calculation on the posture data and the plurality of wheel speeds to obtain a posture deviation value comprises: The vehicle speed is obtained by calculating the average of the plurality of wheel speeds, the steering wheel angle and the front wheel angle are ratio-calculated to obtain a steering ratio, the vehicle speed and the steering ratio are calculated by a yaw angle calculation expression to obtain a desired yaw angular velocity, and the desired yaw angular velocity, the lateral acceleration and the yaw angular velocity are weighted to obtain a posture deviation value.

10. The vehicle posture control method according to claim 8, characterized in that: The step of performing weight calculation on the desired yaw angular velocity, the lateral acceleration and the deflection angular velocity to obtain a posture deviation value comprises: The yaw angular velocity and the desired yaw angular velocity are difference calculated to obtain an angular velocity difference, the lateral acceleration and the set acceleration are difference calculated to obtain an acceleration difference, and the angular velocity difference and the acceleration difference are weighted according to a set weight coefficient to obtain a posture deviation value.

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