Method for independently adjusting rigidity and stroke of four wheels and multi-cavity air suspension system

Abstract

The invention provides a method for independently adjusting rigidity and stroke of four wheels and a multi-cavity air suspension system, and aims to realize active control of dynamic stability of a whole vehicle and self-leveling of the vehicle on an uneven road surface through independent control of rigidity and stroke of the four wheels on the basis of dynamic real-time monitoring of the vehicle and height monitoring of the vehicle body. In the moving process, vehicle stability control is achieved through opening and closing of an electromagnetic valve, and active vehicle dynamic stability control is achieved while the attribute requirement in a vehicle mode is guaranteed; and meanwhile, through signal monitoring of an air suspension controller and an inertial measurement unit IMU, four-wheel air springs are independently adjusted to be inflated and deflated, so that a vehicle body is kept in a relative horizontal posture.

Description

Technical Field

[0001] The invention relates to the field of vehicle manufacturing, and in particular to a method for independently adjusting four-wheel stiffness and travel and a multi-cavity air suspension system. Background Art

[0002] The main function of the air suspension system is to adjust the height of the vehicle body. The multi-chamber air spring system can also preset different stiffnesses in different modes. The stiffness and height follow different modes, and the four wheels are adjusted at the same time. The main function of the multi-chamber air suspension is to improve the vehicle's handling stability and comfort performance. When the customer needs handling stability, the solenoid valve is energized to close it, ensuring that the vehicle's air suspension works in a relatively small volume air chamber and provides a relatively high suspension stiffness; when the customer needs comfort performance, the solenoid valve is not energized to keep it open, ensuring that the vehicle's air suspension works in a relatively large volume air chamber and provides a relatively small suspension stiffness; currently, the vehicle is used in a constant stiffness working mode, and different modes are switched to adjust the stiffness of the four wheels at the same time, and the ability to dynamically control the vehicle body during movement is not fully utilized.

[0003] The air suspension height adjustment mode is roughly different height gears, which are raised or lowered at the same time on the same basis. This meets customer needs when the vehicle is parked on a flat road. However, in scenarios such as outdoors or camping, when the vehicle is parked on an uneven road, the body posture and the uneven road surface present the same uneven state, which cannot meet the customer's personalized specific needs. Customers need independent control and adjustment of the four-wheel height to keep the body in a relatively level state. Summary of the invention

[0004] In view of the defects in the prior art, the object of the present invention is to provide a method for independently adjusting the stiffness and travel of four wheels and a multi-cavity air suspension system.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] A method for independently adjusting four-wheel stiffness and travel, comprising independently adjusting four-wheel stiffness and independently adjusting four-wheel travel;

[0007] The independent adjustment of the four-wheel stiffness includes: in the low stiffness mode, monitoring the vehicle speed, steering wheel angle, longitudinal acceleration and lateral acceleration signals on the bus, when the monitoring signal meets the set threshold, it is determined that the vehicle body posture will have a large change trend at this time, and the air suspension controller issues a command to close the air spring solenoid valve of the axis with a large change trend, so that the air spring corresponding to the axis with a large change trend is switched to high stiffness to ensure that the vehicle body posture is relatively stable, and when the monitoring signal is lower than the set threshold, the air suspension controller issues a command to open the solenoid valve to restore the air spring to low stiffness to maintain the vehicle body comfort requirements;

[0008] The independent adjustment of the four-wheel travel includes: when the vehicle is parked on an uneven road, monitoring the inertial measurement unit IMU angle and suspension travel signal; when the monitoring signal meets a set threshold, determining that the vehicle body posture is uneven at this time, and the air suspension controller sends an inflation or deflation instruction for the four air springs; when the IMU angle is less than the set threshold, the vehicle reaches a horizontal state, and the air spring stops adjusting.

[0009] Preferably, the specific steps of independently adjusting the stiffness of the four wheels include:

[0010] A1: The vehicle is in default state, and the solenoid valve is normally open;

[0011] A2: Determine the vehicle mode. If it is a high stiffness mode, all solenoid valves are closed, and the entire process ends after the solenoid valves are closed. If it is a low stiffness mode, go to step A3.

[0012] A3: Determine the absolute value of the steering wheel angle signal on the bus. If it is greater than the set threshold, proceed to step A4; otherwise, proceed to step A5;

[0013] A4: Determine the absolute value of the lateral acceleration signal on the bus. If it is greater than the set threshold, proceed to step A6; otherwise, proceed to step A5.

[0014] A5: Determine the absolute value of the longitudinal acceleration signal on the bus. If it is greater than the set threshold, go to step A7, otherwise return to the initial state;

[0015] A6: Determine the positive and negative directions of the steering wheel angle on the bus. If it is a positive value, close the right front double-chamber air spring solenoid valve and the right rear double-chamber air spring solenoid valve to increase the stiffness of the right front and right rear overhang of the vehicle and suppress the right side of the body posture from sinking. If it is a negative value, close the left front double-chamber air spring solenoid valve and the left rear double-chamber air spring solenoid valve to increase the stiffness of the left front and left rear overhang of the vehicle and suppress the left side of the body posture from sinking.

[0016] A7: Determine the positive and negative directions of the longitudinal acceleration on the bus. If it is a positive value, close the left rear double-chamber air spring solenoid valve and the right rear double-chamber air spring solenoid valve to increase the stiffness of the left rear overhang and the right rear overhang of the vehicle and suppress the rear sinking of the vehicle body posture; if it is a negative value, close the left front double-chamber air spring solenoid valve and the right front double-chamber air spring solenoid valve to increase the stiffness of the left front overhang and the right front overhang of the vehicle and suppress the front sinking of the vehicle body posture.

[0017] Preferably, the specific steps of independently adjusting the four-wheel travel include:

[0018] B1: The default adjustment times of the vehicle is 0;

[0019] B2: Determine whether the vehicle self-leveling function is turned on. If it is turned off, no self-leveling adjustment is performed and the process returns. If it is turned on, the process proceeds to step B3.

[0020] B3: Determine whether the current vehicle meets the self-leveling state setting requirements. If it is greater than the set threshold, it is determined that the vehicle is currently in a non-level state and needs to be adjusted, and enter step B4. Otherwise, it is determined that the vehicle is currently in a level state and no further adjustment is required, and the adjustment process ends;

[0021] B4: Perform separate inflation and deflation adjustments on the four air springs, and record the number of inflation and deflation adjustments;

[0022] B5: Determine the number of action adjustments in step B4. If it is determined that the number of charge and discharge times is less than the preset number, proceed to step B6, otherwise return to the initial state;

[0023] B6: Determine whether the current suspension travel is close to the vehicle travel capacity limit. If so, end the adjustment process; otherwise, proceed to step B7;

[0024] B7: Check the current vehicle level again. If the vehicle does not meet the self-leveling calibration requirements, return to step B4 to continue adjustment. Otherwise, start timing for 5 seconds and then go to step B8.

[0025] B8: Perform stability check after the vehicle self-leveling adjustment. If the vehicle does not meet the self-leveling calibration requirements, return to step B4 to continue adjustment, otherwise the adjustment process ends.

[0026] A multi-chamber air suspension system with independent adjustment of four-wheel stiffness and travel, used to implement any of the above-mentioned methods for independent adjustment of four-wheel stiffness and travel, comprising:

[0027] Multi-chamber air spring: installed on the four wheels of the vehicle to adjust the suspension stiffness and travel;

[0028] Solenoid valve control device: It is set inside the multi-chamber air spring and is used to control the air chamber switching of the air spring to adjust the suspension stiffness;

[0029] Air suspension controller: used to receive vehicle speed, steering wheel angle, longitudinal acceleration, and lateral acceleration signals, and send control instructions to the solenoid valve control device according to the trend of vehicle body posture changes to achieve independent adjustment of four-wheel stiffness and four-wheel travel;

[0030] Height sensor and inertial measurement unit (IMU) sensor: used to detect suspension height, suspension travel and vehicle tilt angle. The air suspension controller adjusts the four-wheel travel based on the sensor signal to achieve vehicle body leveling.

[0031] Compared with the prior art, the present invention provides a method for independently adjusting the stiffness and travel of four wheels and a multi-chamber air suspension system. Based on real-time monitoring of vehicle dynamics and vehicle height monitoring, the present invention realizes active control of the dynamic stability of the vehicle and self-leveling of the vehicle on uneven roads through independent control of the stiffness and travel of four wheels. During the movement, the vehicle stability control is realized by opening and closing the solenoid valve, which ensures the property requirements in the vehicle mode and realizes active control of the dynamic stability of the vehicle. At the same time, the four-wheel air springs are independently adjusted to charge and discharge through the air suspension controller and the inertial measurement unit IMU signal monitoring to keep the vehicle body in a relatively horizontal posture. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0033] Figure 1 This is a flow chart of independent adjustment of four-wheel stiffness in Example 1;

[0034] Figure 2 This is a flow chart of independent adjustment of four-wheel travel in Example 1;

[0035] Figure 3 This is a framework diagram of a multi-chamber air suspension system with independent adjustment of four-wheel stiffness and travel in Example 2. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0038] It should be noted that similar numbers and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in the subsequent figures. In addition, all directional indications in this application (such as up, down, left, right, front, back, bottom...) are only used to explain the relative position relationship, movement, etc. between the components under a certain specific posture (as shown in the figures). If the specific posture changes, the directional indication will also change accordingly. Furthermore, the descriptions involving "first", "second", etc. in the application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated.

[0039] Example 1

[0040] As shown in the figure, the method for independently adjusting the four-wheel stiffness and travel provided in this embodiment includes independent adjustment of the four-wheel stiffness and independent adjustment of the four-wheel travel.

[0041] The independent adjustment of the four-wheel stiffness includes: in the low stiffness mode, monitoring the vehicle speed, steering wheel angle, longitudinal acceleration and lateral acceleration signals on the bus, when the monitoring signal meets the set threshold, it is determined that the body posture will have a large change trend at this time, and the air suspension controller issues a command to close the air spring solenoid valve of the axis with a large change trend, so that the air spring corresponding to the axis with a large change trend switches to high stiffness to ensure that the body posture is relatively stable, when the monitoring signal is lower than the set threshold, the air suspension controller issues a command to open the solenoid valve to restore the air spring to low stiffness to maintain the body comfort requirements. Specifically, it includes the following steps:

[0042] A1: The vehicle is in default state, and the solenoid valve is normally open;

[0043] A2: Determine the vehicle mode. If it is a high stiffness mode, all solenoid valves are closed, and the entire process ends after the solenoid valves are closed. If it is a low stiffness mode, go to step A3.

[0044] A3: Determine the absolute value of the steering wheel angle signal on the bus. If it is greater than the set threshold, proceed to step A4; otherwise, proceed to step A5;

[0045] A4: Determine the absolute value of the lateral acceleration signal on the bus. If it is greater than the set threshold, proceed to step A6; otherwise, proceed to step A5.

[0046] A5: Determine the absolute value of the longitudinal acceleration signal on the bus. If it is greater than the set threshold, go to step A7, otherwise return to the initial state;

[0047] A6: Determine the positive and negative directions of the steering wheel angle on the bus. If it is a positive value, close the right front double-chamber air spring solenoid valve and the right rear double-chamber air spring solenoid valve to increase the stiffness of the right front and right rear overhang of the vehicle and suppress the right side of the body posture from sinking. If it is a negative value, close the left front double-chamber air spring solenoid valve and the left rear double-chamber air spring solenoid valve to increase the stiffness of the left front and left rear overhang of the vehicle and suppress the left side of the body posture from sinking.

[0048] A7: Determine the positive and negative directions of the longitudinal acceleration on the bus. If it is a positive value, close the left rear double-chamber air spring solenoid valve and the right rear double-chamber air spring solenoid valve to increase the stiffness of the left rear overhang and the right rear overhang of the vehicle and suppress the rear sinking of the vehicle body posture; if it is a negative value, close the left front double-chamber air spring solenoid valve and the right front double-chamber air spring solenoid valve to increase the stiffness of the left front overhang and the right front overhang of the vehicle and suppress the front sinking of the vehicle body posture.

[0049] The independent adjustment of the four-wheel travel includes: when the vehicle is parked on an uneven road, the inertial measurement unit IMU angle and suspension travel signal are monitored. When the monitoring signal meets the set threshold, it is determined that the vehicle body posture is uneven at this time, and the air suspension controller sends out four air spring inflation or deflation instructions. When the IMU angle is less than the set threshold, the vehicle reaches a horizontal state and the air spring stops adjusting. Specifically, the following steps are included:

[0050] B1: The default adjustment times of the vehicle is 0;

[0051] B2: Determine whether the vehicle self-leveling function is turned on. If it is turned off, no self-leveling adjustment is performed and the process returns. If it is turned on, the process proceeds to step B3.

[0052] B3: Determine whether the current vehicle meets the self-leveling state setting requirements. If it is greater than the set threshold, it is determined that the vehicle is currently in a non-level state and needs to be adjusted, and enter step B4. Otherwise, it is determined that the vehicle is currently in a level state and no further adjustment is required, and the adjustment process ends;

[0053] B4: Perform separate inflation and deflation adjustments on the four air springs, and record the number of inflation and deflation adjustments;

[0054] B5: Determine the number of action adjustments in step B4. If it is determined that the number of charge and discharge times is less than the preset number, proceed to step B6, otherwise return to the initial state;

[0055] B6: Determine whether the current suspension travel is close to the vehicle travel capacity limit. If so, end the adjustment process; otherwise, proceed to step B7;

[0056] B7: Check the current vehicle level again. If the vehicle does not meet the self-leveling calibration requirements, return to step B4 to continue adjustment. Otherwise, start timing for 5 seconds and then go to step B8.

[0057] B8: Check the stability of the vehicle after self-leveling adjustment. If the vehicle does not meet the self-leveling calibration requirements, return to step B4 to continue adjustment, otherwise the adjustment process ends;

[0058] Example 2

[0059] like Figure 3 As shown, the multi-chamber air suspension system with four-wheel stiffness and travel independently adjusted provided in this embodiment is used to implement the method for independently adjusting the four-wheel stiffness and travel described in the above embodiment, including:

[0060] Multi-chamber air spring: installed on the four wheels of the vehicle to adjust the suspension stiffness and travel;

[0061] Solenoid valve control device: It is set inside the multi-chamber air spring and is used to control the air chamber switching of the air spring to adjust the suspension stiffness;

[0062] Air suspension controller: used to receive vehicle speed, steering wheel angle, longitudinal acceleration, and lateral acceleration signals, and send control instructions to the solenoid valve control device according to the trend of vehicle body posture changes to achieve independent adjustment of four-wheel stiffness and four-wheel travel;

[0063] Height sensor and inertial measurement unit (IMU) sensor: used to detect suspension height, suspension travel and vehicle tilt angle. The air suspension controller adjusts the four-wheel travel based on the sensor signal to achieve vehicle body leveling.

[0064] The above describes the specific embodiments of the present invention. Based on the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention.

Claims

1. A method for independently adjusting the stiffness and travel of four wheels, characterized in that: Including independent adjustment of four-wheel stiffness and four-wheel travel; The independent adjustment of the four-wheel stiffness includes: in the low stiffness mode, monitoring the vehicle speed, steering wheel angle, longitudinal acceleration and lateral acceleration signals on the bus, when the monitoring signal meets the set threshold, it is determined that the vehicle body posture will have a large change trend at this time, and the air suspension controller issues a command to close the air spring solenoid valve of the axis with a large change trend, so that the air spring corresponding to the axis with a large change trend is switched to high stiffness to ensure that the vehicle body posture is relatively stable, and when the monitoring signal is lower than the set threshold, the air suspension controller issues a command to open the solenoid valve to restore the air spring to low stiffness to maintain the vehicle body comfort requirements; The independent adjustment of the four-wheel travel includes: when the vehicle is parked on an uneven road, monitoring the inertial measurement unit IMU angle and suspension travel signal; when the monitoring signal meets a set threshold, determining that the vehicle body posture is uneven at this time, and the air suspension controller sends an inflation or deflation instruction for the four air springs; when the IMU angle is less than the set threshold, the vehicle reaches a horizontal state, and the air spring stops adjusting.

2. The method according to claim 1, characterized in that: The specific steps of independently adjusting the four-wheel stiffness include: A1: The vehicle is in default state, and the solenoid valve is normally open; A2: Determine the vehicle mode. If it is a high stiffness mode, all solenoid valves are closed, and the entire process ends after the solenoid valves are closed. If it is a low stiffness mode, go to step A3. A3: Determine the absolute value of the steering wheel angle signal on the bus. If it is greater than the set threshold, proceed to step A4; otherwise, proceed to step A5; A4: Determine the absolute value of the lateral acceleration signal on the bus. If it is greater than the set threshold, proceed to step A6; otherwise, proceed to step A5. A5: Determine the absolute value of the longitudinal acceleration signal on the bus. If it is greater than the set threshold, go to step A7, otherwise return to the initial state; A6: Determine the positive and negative directions of the steering wheel angle on the bus. If it is a positive value, close the right front double-chamber air spring solenoid valve and the right rear double-chamber air spring solenoid valve to increase the stiffness of the right front and right rear overhang of the vehicle and suppress the right side of the body posture from sinking. If it is a negative value, close the left front double-chamber air spring solenoid valve and the left rear double-chamber air spring solenoid valve to increase the stiffness of the left front and left rear overhang of the vehicle and suppress the left side of the body posture from sinking. A7: Determine the positive and negative directions of the longitudinal acceleration on the bus. If it is a positive value, close the left rear double-chamber air spring solenoid valve and the right rear double-chamber air spring solenoid valve to increase the stiffness of the left rear overhang and the right rear overhang of the vehicle and suppress the rear sinking of the vehicle body posture; if it is a negative value, close the left front double-chamber air spring solenoid valve and the right front double-chamber air spring solenoid valve to increase the stiffness of the left front overhang and the right front overhang of the vehicle and suppress the front sinking of the vehicle body posture.

3. The method according to claim 1, characterized in that: The specific steps of independently adjusting the four-wheel travel include: B1: The default adjustment times of the vehicle is 0; B2: Determine whether the vehicle self-leveling function is turned on. If it is turned off, no self-leveling adjustment is performed and the process returns. If it is turned on, the process proceeds to step B3. B3: Determine whether the current vehicle meets the self-leveling state setting requirements. If it is greater than the set threshold, it is determined that the vehicle is currently in a non-level state and needs to be adjusted, and enter step B4. Otherwise, it is determined that the vehicle is currently in a level state and no further adjustment is required, and the adjustment process ends; B4: Perform separate inflation and deflation adjustments on the four air springs, and record the number of inflation and deflation adjustments; B5: Determine the number of action adjustments in step B4. If it is determined that the number of charge and discharge times is less than the preset number, proceed to step B6, otherwise return to the initial state; B6: Determine whether the current suspension travel is close to the vehicle travel capacity limit. If so, end the adjustment process; otherwise, proceed to step B7; B7: Check the current vehicle level again. If the vehicle does not meet the self-leveling calibration requirements, return to step B4 to continue adjustment. Otherwise, start timing for 5 seconds and then go to step B8. B8: Perform stability check after the vehicle self-leveling adjustment. If the vehicle does not meet the self-leveling calibration requirements, return to step B4 to continue adjustment, otherwise the adjustment process ends.

4. A multi-chamber air suspension system with independent adjustment of four-wheel stiffness and travel, used to implement the method for independent adjustment of four-wheel stiffness and travel as described in any one of claims 1 to 3 above, characterized in that: include: Multi-chamber air spring: installed on the four wheels of the vehicle to adjust the suspension stiffness and travel; Solenoid valve control device: It is set inside the multi-chamber air spring and is used to control the air chamber switching of the air spring to adjust the suspension stiffness; Air suspension controller: used to receive vehicle speed, steering wheel angle, longitudinal acceleration, and lateral acceleration signals, and send control instructions to the solenoid valve control device according to the trend of vehicle body posture changes to achieve independent adjustment of four-wheel stiffness and four-wheel travel; Height sensor and inertial measurement unit (IMU) sensor: used to detect suspension height, suspension travel and vehicle tilt angle. The air suspension controller adjusts the four-wheel travel based on the sensor signal to achieve vehicle body leveling.

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