A control method, control system, device and medium of a vehicle air suspension

Abstract

The application provides a control method, a control system, a device and a medium for a vehicle air suspension, the control method comprising: obtaining a target torque and a target hop control force of the vehicle air suspension; determining a target stiffness gear of a multi-cavity air spring according to the target torque, and adjusting the current stiffness gear of all multi-cavity air springs to the target stiffness gear; calculating a target spring force of a single multi-cavity air spring under the target stiffness gear; calculating a target damping force of a single damping adjustable shock absorber according to the target torque, the target hop control force and the target spring force; and adjusting the current damping force of the damping adjustable shock absorber to the target damping force. The control method in the application can realize the collaborative control between the damping force and the stiffness in the vehicle air suspension.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vehicle air suspension control, and particularly relates to a control method, a control system, a device and a medium for a vehicle air suspension. BACKGROUND

[0002] With the continuous improvement of consumer demand for automobile comfort and the development of related industry technology, multi-cavity air suspensions have been increasingly widely applied in today's automobile market. The multi-cavity air suspension system can have the functions of adjustable damping shock absorber damping adjustment, vehicle body height control and spring stiffness adjustment due to the inclusion of multi-cavity air springs and adjustable damping shock absorbers. The control method of the multi-cavity air suspension directly affects the adjustment effect of the adjustable damping shock absorber damping and the air spring stiffness, and further affects the driving comfort and handling stability.

[0003] In the control method of the existing multi-cavity air suspension system, the stiffness of the multi-cavity air spring and the damping of the adjustable damping shock absorber are basically controlled independently during vehicle operation. This often makes it difficult to meet the requirements for coordinated control of damping force and spring stiffness under dynamic conditions, thereby limiting the improvement of driving comfort and handling stability during vehicle driving. SUMMARY

[0004] In view of the above shortcomings of the prior art, the present application provides a control method, a control system, a device and a medium for a vehicle air suspension to improve the technical problem that coordinated control of damping force and spring stiffness cannot be achieved in the control process of the existing vehicle air suspension.

[0005] The first aspect of the present application is to provide a control method for a vehicle air suspension, the vehicle air suspension comprising a plurality of multi-cavity air springs and a plurality of adjustable damping shock absorbers, the multi-cavity air spring having a plurality of stiffness gears, and the damping of the adjustable damping shock absorber being continuously adjustable; the control method comprising: obtaining a target torque and a target jump control force of the vehicle air suspension; determining a target stiffness gear of the multi-cavity air spring according to the target torque, and adjusting the current stiffness gear of all multi-cavity air springs to the target stiffness gear; calculating a target spring force of a single multi-cavity air spring under the target stiffness gear; calculating a target damping force of a single adjustable damping shock absorber according to the target torque, the target jump control force and the target spring force; and adjusting the current damping force of the adjustable damping shock absorber to the target damping force.

[0006] In an example of the control method of the present application, the target torque comprises a target pitch torque and a target roll torque of the vehicle air suspension.

[0007] In an example of the control method, the target stiffness gear of the multi-chamber air spring is determined according to the target torque, and the current stiffness gears of all the multi-chamber air springs are adjusted to the target stiffness gear, including: calculating the individual estimated output air spring forces of all the multi-chamber air springs at multiple stiffness gears; calculating the estimated output air spring torques of all the multi-chamber air springs at each stiffness gear according to the individual estimated output air spring forces; calculating the differences between the estimated output air spring torques of all the multi-chamber air springs at each stiffness gear and the target torque respectively; selecting the stiffness gear corresponding to the estimated output air spring torque with the smallest difference with the target torque as the target stiffness gear; and adjusting the current stiffness gears of all the multi-chamber air springs to the target stiffness gear.

[0008] In an example of the control method, the current stiffness gears of all the multi-chamber air springs are adjusted to the target stiffness gear, including: obtaining the current stiffness gear of the multi-chamber air spring; determining whether the current stiffness gear is consistent with the target stiffness gear; if yes, the current stiffness gear is not adjusted; and if no, the current stiffness gear is adjusted to the target stiffness gear.

[0009] In an example of the control method, the multi-chamber air spring includes multiple stiffness adjustment valves, and the open-close combination state of the multiple stiffness adjustment valves corresponds to multiple stiffness gears; the current stiffness gear is adjusted to the target stiffness gear, including: obtaining the open-close state of the multiple stiffness adjustment valves corresponding to the current stiffness gear, and determining the current stiffness control current of the multiple stiffness adjustment valves according to the open-close state; and adjusting the current stiffness control current to the target stiffness control current.

[0010] In an example of the control method, the current stiffness control current is adjusted to the target stiffness control current, including: obtaining the current driving mode of the vehicle and the current road level; determining the stiffness control target current range according to the driving mode and the road level; if the target stiffness control current is within the stiffness control target current range, the target stiffness control current is output; and if the target stiffness control current is out of the stiffness control target current range, the upper limit value or the lower limit value of the stiffness control target current range is output.

[0011] In an example of the control method, the adjustable damping shock absorber includes a damping adjustment valve, and the damping control current of the damping adjustment valve corresponds to the damping force; the current damping force is adjusted to the target damping force, including:

[0012] The current damping control current corresponding to the current damping force and the target damping control current corresponding to the target damping force are obtained; it is determined whether the current damping control current is consistent with the target damping control current; if yes, the current damping control current is not adjusted; and if no, the current damping control current is adjusted to the target damping control current.

[0013] In an example of the control method of the present application, adjusting the current damping control current to the target damping control current comprises: obtaining the current driving mode and the road level of the vehicle; determining the damping control target current range according to the driving mode and the road level; outputting the target damping control current if the target damping control current is within the damping control target current range; outputting the upper limit value or the lower limit value of the damping control target current if the target damping control current is beyond the damping control target current range.

[0014] A second aspect of the present application is to provide a control system of a vehicle air suspension, the vehicle air suspension comprising a plurality of multi-cavity air springs and a plurality of damping-adjustable shock absorbers, the multi-cavity air spring having a plurality of stiffness gears, and the damping-adjustable shock absorber having continuously adjustable damping; the control system comprising: an obtaining module, an adjusting module, a spring force calculation module, a damping force calculation module, and a damping adjusting module; the obtaining module is configured to obtain a target torque and a target jump control force of the vehicle air suspension; the stiffness adjusting module is configured to determine a target stiffness gear of the multi-cavity air spring according to the target torque, and adjust the current stiffness gear of all multi-cavity air springs to the target stiffness gear; the spring force calculation module is configured to calculate a target spring force of a single multi-cavity air spring under the target stiffness gear; the damping force calculation module is configured to calculate a target damping force of a single damping-adjustable shock absorber according to the target torque and the target jump control force; and the damping adjusting module is configured to adjust the current damping force of the damping-adjustable shock absorber to the target damping force.

[0015] A third aspect of the present application is to provide an electronic device, comprising: a storage device and one or more processors. The storage device is configured to store one or more programs, when the one or more programs are executed by the one or more processors, the electronic device is caused to implement the control method of any one of the above.

[0016] A fourth aspect of the present application is to provide a computer-readable storage medium, the computer-readable storage medium storing a computer program, when the computer program is executed by a processor of a computer, the computer is caused to execute the control method of any one of the above.

[0017] The control method, control system, device and medium of the vehicle air suspension provided by the application can determine the target stiffness gear of the multi-cavity air spring according to the target control torque and the jump control force of the vehicle air suspension, and adjust the current stiffness gear of all multi-cavity air springs to the target stiffness gear; calculate the target spring force of a single multi-cavity air spring under the target stiffness gear; calculate the target damping force of a single damping adjustable shock absorber according to the target torque, the target jump control force and the target spring force; and adjust the current damping force of the damping adjustable shock absorber to the target damping force. The control method can establish a connection between the stiffness adjustment of the multi-cavity air spring and the damping force adjustment of the damping adjustable shock absorber, realize the coordinated control between the damping force and the spring stiffness under dynamic working conditions, and thus improve the comfort and control stability of the vehicle during driving. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A flowchart of the control method of the vehicle air suspension provided by an embodiment of the application is shown in the figure;

[0019] Figure 2 A partial flowchart of step S2 provided by an embodiment of the application is shown in the figure;

[0020] Figure 3 A partial flowchart of step S25 provided by an embodiment of the application is shown in the figure;

[0021] Figure 4 A flowchart of step S254 provided by an embodiment of the application is shown in the figure;

[0022] Figure 5 A flowchart of step S2542 provided by an embodiment of the application is shown in the figure;

[0023] Figure 6 A mechanical model diagram of the vehicle air suspension of an embodiment of the application is shown in the figure;

[0024] Figure 7 A flowchart of step S5 provided by an embodiment of the application is shown in the figure;

[0025] Figure 8 A flowchart of step S54 provided by an embodiment of the application is shown in the figure;

[0026] Figure 9 A logic flowchart of the control method of the vehicle air suspension provided by an embodiment of the application is shown in the figure;

[0027] Figure 10 A structure block diagram of the control system of the vehicle air suspension provided by an embodiment of the application is shown in the figure;

[0028] Figure 11 A structure diagram of an electronic device provided by an embodiment of the application is shown in the figure. DETAILED DESCRIPTION

[0029] Other advantages and embodiments of the application will be more readily appreciated from the following description, taken in conjunction with the accompanying drawings. The description, together with the drawings, makes apparent to those skilled in the art how the several embodiments of the application can be implemented and applied. The description, together with the drawings, makes apparent to those skilled in the art how the several embodiments of the application can be implemented and applied. The following examples and features in the examples can be combined with each other, without conflict, where appropriate.

[0030] It should be noted that the drawings provided in the following embodiments only schematically illustrate the basic concept of the present application, and only the components related to the present application are shown in the drawings, rather than being drawn according to the number, shape and size of the components in actual implementation. The actual implementation of each component can be a random change, and the component layout pattern can be more complex.

[0031] In the following description, a large number of details are discussed to provide a more thorough explanation of the embodiments of the application, however, it is obvious to those skilled in the art that the embodiments of the application can be implemented without these specific details, and in other embodiments, well-known structures and devices are shown in the form of block diagrams rather than in detail, to avoid making the embodiments of the application difficult to understand.

[0032] The vehicle air suspension is an important part of the automobile, which connects the wheels and the body, mainly responsible for absorbing the impact and vibration caused by road unevenness, maintaining the stability and comfort of the vehicle during driving. With the development of automobile technology, the vehicle air suspension control system is also more and more advanced, and the vehicle air suspension can have the functions of adjustable damper damping, body height and spring stiffness adjustment because it contains a multi-cavity air spring system and a damping adjustable shock absorber system. At present, it is more and more widely used in automobiles.

[0033] The applicant found that in the existing vehicle air suspension control method, the stiffness control of the multi-cavity air spring system and the damping control of the damping adjustable shock absorber system are basically independent of each other. Therefore, during vehicle driving, the stiffness and damping of the vehicle air suspension cannot be cooperatively controlled, which limits the improvement of comfort and control stability during vehicle driving. In view of this, the applicant has carried out corresponding research, thereby providing a control method, a control system, a device and a medium for a vehicle air suspension, which can establish a connection between the stiffness adjustment of the multi-cavity air spring system and the damping adjustment of the damping adjustable shock absorber, and realize the cooperative control between the stiffness and the damping of the vehicle air suspension under dynamic working conditions, so that better comfort and control stability can be obtained during vehicle driving.

[0034] The vehicle air suspension in the embodiments of the present application comprises a plurality of multi-cavity air springs and a plurality of damping adjustable shock absorbers. The multi-cavity air springs and the damping adjustable shock absorbers play a role of supporting and guiding in the vehicle air suspension system, ensuring that the wheels of the vehicle can move along the designed track while absorbing and transmitting the force and torque from the road. The multi-cavity air springs and the damping adjustable shock absorbers are usually arranged in a one-to-one correspondence, that is, one multi-cavity air spring and one damping adjustable shock absorber are used together. The number of multi-cavity air springs and damping adjustable shock absorbers usually matches the number of tires of the vehicle. A passenger vehicle usually has four multi-cavity air springs and four damping adjustable shock absorbers, while a special vehicle may vary according to the number of tires.

[0035] For most passenger vehicles (such as cars, SUVs, MPVs, etc.) equipped with a multi-cavity air spring system, they usually have four wheels, so there are four multi-cavity air springs and four damping adjustable shock absorbers corresponding to them, and each wheel corresponds to one multi-cavity air spring and one damping adjustable shock absorber. The multi-cavity air springs and the damping adjustable shock absorbers can be separate component structures or integrated unit structures, depending on the design structure and installation size of the vehicle air suspension. In the following embodiments of the present application, four multi-cavity air springs and four damping adjustable shock absorbers are used as examples. The above-mentioned four multi-cavity air springs and four damping adjustable shock absorbers correspond to the four wheels of the vehicle and are distributed on the left front, right front, left rear, and right rear of the vehicle. The multi-cavity air spring has multiple stiffness gears, such as two stiffness gears, three stiffness gears, four stiffness gears, etc. It should be noted that during normal operation of the vehicle air suspension, the current stiffness gear of the plurality of multi-cavity air springs always remains consistent.

[0036] Please refer to Figure 1 and Figure 8 The control method comprises the following processes:

[0037] S1, obtaining a target torque and a target jump control force of the vehicle air suspension;

[0038] S2, determining a target stiffness gear of the multi-cavity air spring according to the target torque, and adjusting the current stiffness gear of all the multi-cavity air springs to the target stiffness gear;

[0039] S3, calculating a target spring force of a single multi-cavity air spring under the target stiffness gear;

[0040] S4, calculating a target damping force of a single damping adjustable shock absorber according to the target torque, the target jump control force, and the target spring force;

[0041] S5, adjusting the current damping force of the damping adjustable shock absorber to the target damping force.

[0042] The control method can determine the target stiffness gear of the multi-cavity air spring through the target control torque and the jump control force of the vehicle air suspension, and adjust the current stiffness gear of all multi-cavity air springs to the target stiffness gear; calculate the target spring force of a single multi-cavity air spring under the target stiffness gear; calculate the target damping force of a single damping adjustable shock absorber according to the target torque, the target jump control force and the target spring force, and adjust the current damping force of the damping adjustable shock absorber to the target damping force. The control method can link the stiffness adjustment of the multi-cavity air spring with the damping force adjustment of the damping adjustable shock absorber, and realize the coordinated control between the damping force and the spring stiffness in the dynamic working condition, so as to improve the comfort and control stability of the vehicle during driving.

[0043] The following will be described in detail.

[0044] S1, obtaining the target control torque and the target jump control force of the vehicle air suspension. In this step, the target control torque of the vehicle air suspension includes the target control torque of the vehicle roll and the target control torque of the vehicle pitch, etc. In this embodiment, the target control torque is the target pitch torque and the target roll torque of the vehicle air suspension. There are many ways to obtain the target roll torque, the target pitch torque and the target jump control force of the vehicle. Preferably, in this embodiment, the vehicle body is provided with a six-axis inertial sensor and a vehicle body height sensor. The vehicle body pitch angular velocity v pitch and the vehicle body roll attitude v roll can be calculated by the six-axis inertial sensor. The vehicle body vertical jumping speed v heave can be calculated according to the vehicle body height sensor. Finally, the target roll torque, the target pitch torque and the target jump control force of the vehicle can be calculated according to the vehicle body pitch angular velocity v pitch , the vehicle body roll attitude v roll and the vehicle body vertical jumping speed v heave . In this embodiment, since the vehicle body height sensor and the six-axis inertial sensor are both components originally installed on the vehicle for driving control, it is not necessary to additionally set up sensor components for the control method in this embodiment, which can save the number of vehicle parts and thus save the control cost of the stiffness and damping adjustment of the vehicle air suspension. Of course, in other embodiments, the six-axis inertial sensor can be replaced by three single acceleration sensors respectively measuring the height of the vehicle body, the longitudinal direction or the lateral direction of the vehicle body. In this embodiment, the target jump control force of the vehicle air suspension refers to the force used to control the bounce or vibration of the vehicle when encountering uneven road or other impact during driving.

[0045] S2, determine a target stiffness gear of the multi-cavity air springs according to the target torque, and adjust the current stiffness gears of all the multi-cavity air springs to the target stiffness gear. In this step, the multi-cavity air springs correspond to different output torques at different stiffness gears. According to the target torque, the target stiffness gear of the multi-cavity air springs is determined by comparing the output torque of the multi-cavity air springs at different stiffness gears with the target torque to determine the stiffness gear at which the output torque of the multi-cavity air springs is closest to the target torque as the target stiffness gear. It should be noted that the output torque of the multi-cavity air springs in this embodiment refers to the sum of the output torques of all the multi-cavity air springs. At the same time, all the multi-cavity air springs on the vehicle air suspension always operate at the same stiffness gear.

[0046] Please refer to Figure 2 In an embodiment of the control method of the application, in step S2, the target stiffness gear of the multi-cavity air springs is determined according to the target torque, and the current stiffness gears of all the multi-cavity air springs are adjusted to the target stiffness gear, which specifically includes steps S21 to S25:

[0047] S21, calculate the single estimated output air spring force of all the multi-cavity air springs at the plurality of stiffness gears. In this step, the specific calculation process of the single estimated output air spring force is as follows: first, obtain the compression or elongation of a single multi-cavity air spring through the height sensor installed on the vehicle, that is, obtain the displacement rate Δx of the multi-cavity air spring; second, obtain the air pressure Px of each multi-cavity air spring through the pressure sensor installed on the multi-cavity air spring; and finally, according to the current stiffness gear, the displacement rate Δx and the air pressure Px, the spring force Fx of the corresponding air spring is read from the stiffness-displacement characteristic curve corresponding to the multi-cavity air spring by interpolation. According to the above steps, the single estimated output air spring force of all the multi-cavity air springs at the current stiffness gear can be calculated. The spring force calculation method of the multi-cavity air spring corresponding to other stiffness gears is the same.

[0048] S22, calculate the estimated output air spring torque of all the multi-cavity air springs at each stiffness gear according to the single estimated output air spring force. For example, when the multi-cavity air spring has three stiffness gears, the different estimated output air spring torques N1, N2 and N3 of all the multi-cavity air springs at the first stiffness gear, the second stiffness gear and the third stiffness gear are calculated respectively.

[0049] S23, calculate the difference between the estimated output air spring torque of all the multi-cavity air springs at each stiffness gear and the target torque respectively. In this step, the target torque is marked as N 目, the difference between the estimated output air spring torque of all multi-cavity air springs in each stiffness gear and the target torque is calculated, i.e. the difference between N1 and N 目 , the difference between N2 and N 目 , and the difference between N3 and N 目 . It should be noted that the difference here refers to the absolute difference.

[0050] S24, the stiffness gear corresponding to the estimated output air spring torque with the smallest difference from the target torque is selected as the target stiffness gear. That is, the estimated output air spring torque closest to the target torque value is first determined, then the stiffness gear corresponding to the estimated output air spring torque is determined, and finally the stiffness gear is taken as the target stiffness gear.

[0051] S25, the current stiffness gears of all multi-cavity air springs are adjusted to the target stiffness gear.

[0052] Please refer to Figure 3 and Figure 8 , in this step S25, the current stiffness gears of all multi-cavity air springs are adjusted to the target stiffness gear, which specifically includes the following steps S251 to S254:

[0053] S251, the current stiffness gear of the multi-cavity air spring is obtained. In this step, the current stiffness gear of the multi-cavity air spring can be read by a controller on the vehicle, or the current stiffness gear display device provided on the vehicle can be used to read the current stiffness gear of the multi-cavity air spring.

[0054] S252, it is judged whether the current stiffness gear is consistent with the target stiffness gear. In this step, the stiffness gear obtained in step S251 is compared with the target stiffness gear. The comparison method is not limited, which can be to judge and compare the output control current size corresponding to different stiffness gears, or to judge and compare the closing state of the switch valve corresponding to different stiffness gears, etc.

[0055] S253, if yes, the current stiffness gear is not adjusted. In this step, if it is judged in step S252 that the current stiffness gear is consistent with the target stiffness gear, the current stiffness gear is taken as the target stiffness gear, i.e. the target stiffness gear adjustment of all multi-cavity air springs is completed. In this way, the control calculation steps of stiffness adjustment can be simplified, and the efficiency of stiffness adjustment can be improved.

[0056] S254、If not, adjust the current stiffness notch to the target stiffness notch. In this step, if the step S252 judges that the current stiffness notch is inconsistent with the target stiffness notch, the current stiffness notch of all multi-cavity air springs needs to be adjusted to the target stiffness notch, so as to complete the adjustment of the target stiffness notch of all multi-cavity air springs.

[0057] In order to realize the stiffness adjustment of the multi-cavity air spring, the multi-cavity air spring is provided with a plurality of stiffness adjustment valves, so as to realize the adjustment of different stiffness notches by controlling the on-off between different cavities. The number of stiffness adjustment valves is related to the number of stiffness notches, and the specific number is subject to the adjustment requirements of the stiffness notches. The stiffness adjustment valve can be in a mechanical adjustment mode, an electromagnetic control mode, etc. Preferably, in the embodiment, the stiffness adjustment valve is in an electromagnetic control mode. The on-off combination state of the plurality of stiffness adjustment valves corresponds to the plurality of stiffness notches. Please refer to Figure 4 and Figure 8 In an embodiment of the control method of the application, in the step S254, adjusting the current stiffness notch to the target stiffness notch comprises the following steps S2541-S2542:

[0058] S2541, obtain the on-off state of the plurality of stiffness adjustment valves corresponding to the current stiffness notch, and determine the current stiffness control current of the plurality of stiffness adjustment valves according to the on-off state. In this step, the current stiffness control current of the corresponding stiffness adjustment valve can be found by judging the current on-off state of the stiffness adjustment valve.

[0059] S2542, adjust the current stiffness control current to the target stiffness control current. In this step, when adjusting the current stiffness control current to the target stiffness control current, the vehicle controller can be provided with a plurality of buttons corresponding to the stiffness control current, and the operation of adjusting the current stiffness control current to the target stiffness control current can be completed by closing the button corresponding to the current stiffness control current and opening the button corresponding to the target stiffness control current. The vehicle controller can also store a plurality of control programs corresponding to different control currents in the internal program, and the operation of adjusting the current stiffness control current to the target stiffness control current can be completed by running different control programs.

[0060] Please refer to Figure 5 and Figure 8 In an embodiment of the control method of the application, adjusting the current stiffness control current to the target stiffness control current comprises the steps S25421-S25424:

[0061] S25421, obtain the current driving mode and road surface level of the vehicle. The driving mode of the vehicle commonly includes standard mode, economy mode, sports mode, off-road mode, etc., and different vehicle types can have different driving modes preset. The driving mode of the vehicle is different, and the stiffness and damping size of the air suspension of the vehicle are generally different. For example, in the comfort mode, the vehicle generally pursues a smooth and quiet ride experience. The stiffness of the vehicle air spring is generally set to be soft, and the damping force is also adjusted to be low to better cope with the impact of the bumps and unevenness of the road. In the sports mode, the stiffness of the vehicle air spring is generally increased to provide better lateral support and vehicle handling. The damping is also increased to reduce the inclination and swing of the vehicle body when turning, and to improve the response speed of the vehicle. The road surface level generally includes asphalt pavement, Belgian pavement, gravel pavement and undulating pavement, etc. The stiffness of the vehicle air spring and the damping of the shock absorber are different when the vehicle air suspension drives on roads of different road surface levels. The current driving mode and the current road surface level of the vehicle can be obtained through the sensors and control systems of the vehicle, such as through the wheel acceleration sensor, the vehicle body acceleration sensor, the height sensor, the wheel speed sensor, etc. to detect the driving state of the vehicle, and the electronic control unit (ECU) or advanced driver assistance system (ADAS) of the vehicle to analyze and adjust the corresponding driving mode.

[0062] S25422, determine the stiffness control target current range according to the driving mode and the road surface level. The stiffness control target current range includes an upper stiffness control current and a lower stiffness control current. Generally, the vehicle has a corresponding stiffness interval according to the driving mode and the road surface level, and the stiffness interval corresponds to generate a stiffness control target current range, and the upper stiffness limit value and the lower stiffness limit value corresponding to the stiffness interval correspond to the upper stiffness control current and the lower stiffness control current. That is, when the vehicle is in a certain driving mode and a certain road surface level, the stiffness target control current of the corresponding vehicle air suspension cannot exceed the corresponding stiffness control target current range.

[0063] S25423, if the target stiffness control current is within the stiffness control target current range, output the target stiffness control current. In this step, under the condition of corresponding driving mode and road surface level, the target stiffness control current corresponding to the target stiffness of the multi-cavity air spring needs to be determined before outputting the target stiffness control current. If the target stiffness control current is within the stiffness control target current range, the target stiffness control current is output.

[0064] S25424, if the target rigidity control current exceeds the rigidity control target current range, output the upper limit value or the lower limit value of the rigidity control target current range. In this step, if the target rigidity control current is less than the lower limit rigidity control current, the lower limit rigidity control current is directly output; if the target rigidity control current is greater than the upper limit rigidity control current, the upper limit rigidity control current is directly output. In this way, the probability of the multi-cavity air spring rigidity adjustment error caused by the target rigidity control current calculation error can be reduced, not only the related electrical components can be effectively protected, but also the accuracy of the multi-cavity air spring rigidity adjustment during the operation of the vehicle air suspension can be improved.

[0065] S3, calculate the target spring force of each of the multi-cavity air springs in the target rigidity gear. After the current rigidity gears of all the multi-cavity air springs are adjusted to the target rigidity gear in step S25, the target rigidity of the multi-cavity air springs can be obtained, and the displacement rate Δx of each multi-cavity air spring and the air pressure Px of each multi-cavity air spring are obtained again according to the target rigidity; and the rigidity coefficient k of each multi-cavity air spring is read from the rigidity-displacement characteristic curve corresponding to the multi-cavity air spring by interpolation, and the target spring force of each multi-cavity air spring is calculated. Specifically, in the embodiment, four multi-cavity air springs are provided, i.e. four displacement rates Δx are obtained, which are marked as Δx1, Δx2, Δx3 and Δx4. Four rigidity coefficients k are obtained according to the rigidity-displacement characteristic curve corresponding to the multi-cavity air spring, which are marked as k1, k2, k3 and k4, and the target rigidity gear of the four multi-cavity air springs can be calculated according to the rigidity coefficient k and the rate Δx.

[0066] The damping adjustment mode of the adjustable damping shock absorber can be various, for example, manual adjustment, which adjusts the damping by manually changing the opening size of the valve in the adjustable damping shock absorber. It can also be hydraulic adjustment, which adjusts the damping by changing the flow of hydraulic oil in the adjustable damping shock absorber. It can also be to control the opening of the electromagnetic valve by the current size of the electromagnetic valve, to adjust the flow of gas or hydraulic oil in the adjustable damping shock absorber, and then to adjust the damping force of the shock absorber. In the embodiment, the adjustable damping shock absorber comprises a damping adjustment valve, and the size of the damping control current of the damping adjustment valve corresponds to the size of the damping force. The corresponding relationship between the damping control current and the damping force is not limited, which can be a linear proportional relationship, or a corresponding relationship satisfying a specific function, etc. In actual application, the corresponding relationship between the damping control current and the damping force is the inherent parameter of each adjustable damping shock absorber, which can be obtained from the selection parameter table or the instruction manual of the adjustable damping shock absorber. Preferably, in the embodiment, the damping adjustment valve is a proportional valve to realize continuous adjustment of the damping of the adjustable damping shock absorber.

[0067] S4, calculating the target damping force of the single damping adjustable shock absorber according to the target torque, the target jump control force and the target spring force. In this step, the target damping force of the single damping adjustable shock absorber is calculated according to the target torque, the target jump control force and the target spring force, and the specific calculation process is as follows (taking the vehicle air suspension provided with four multi-cavity air springs and four damping adjustable shock absorbers as an example): as shown in Figure 6 The schematic diagram of the mechanical model of the vehicle air suspension is shown. According to Figure 6 The mechanical analysis shown in the formula is as follows:

[0068] The vertical motion equation at the mass center of the vehicle body is: Marked as formula 1.

[0069] The pitch motion equation of the vehicle body is: Marked as formula 2.

[0070] The roll motion equation of the vehicle body is: Marked as formula 3.

[0071] From the equations of formulas 1 to 3, the calculation formula 4 of F1, F2, F3 and F4 is derived as follows:

[0072]

[0073] It is assumed that the torque of the roll attitude is provided by the front axle and the rear axle in a 1:1 ratio, and the above motion equations 1, 2 and 3 can be modified as:

[0074]

[0075] Wherein, F1, F2, F3, F4, the force (spring force + damping force) of the four suspension assemblies;

[0076] k1, k2, k3, k4, the spring stiffness of the four multi-cavity air springs;

[0077] c1, c2, c3, c4, the damping coefficient of the four damping adjustable shock absorbers;

[0078] Z b1 , Z b2 , Z b3 , Z b4 , the vertical displacement of the vehicle body at the positions of the four shock absorbers;

[0079] Z w1 , Z w2 , Z w3 , Z w4 , the vertical displacement of the four wheels;

[0080] The vertical moving speed of the vehicle body at the positions of the four shock absorbers;

[0081] 4 vertical movement speed of the wheel;

[0082] T pitch : vehicle pitch target control torque;

[0083] T roll : vehicle roll target control torque;

[0084] F Heave : target hop control force;

[0085] I θ : moment of inertia;

[0086] pitch angle acceleration;

[0087] roll angle acceleration;

[0088] L f : distance from the center of mass to the front axle;

[0089] L r : distance from the center of mass to the rear axle;

[0090] T f : half of the front axle wheel end distance;

[0091] T r : half of the rear axle wheel end distance.

[0092] The target damping force of the four damping adjustable shock absorbers can be calculated by the above formula. It should be noted that Z b1 , Z b2 , Z b3 , Z b4 , Z w1 , Z w2 , Z w3 , Z w4 , can be obtained by various sensors installed on the vehicle (such as speed sensor, acceleration sensor, vehicle height sensor, etc.), so as to determine the damping coefficients c1, c2, c3 and c4 in formula 4 and further determine the damping force of the four shock absorbers.

[0093] In step S5, the current damping force is adjusted to the target damping force, specifically the current damping force of each of the damping adjustable shock absorbers is adjusted to the target damping force, please refer to Figure 7 , specifically including steps S51-S54:

[0094] S51, obtaining a current damping control current corresponding to the current damping force and a target damping control current corresponding to the target damping force. In this step, since the damping control current of the damping adjusting valve corresponds to the damping force, the current damping control current is obtained, that is, the current damping control current of the damping adjusting valve is obtained. Since the damping control current of the damping adjusting valve and the damping force form an inherent relationship curve, the target damping control current corresponding to the target damping force can be obtained from the relationship curve on the premise that the target damping force is known.

[0095] S52, determining whether the current damping control current is consistent with the target damping control current. In this step, whether the current damping control current is consistent with the target damping control current can be determined by the controller of the vehicle itself, or can be determined by other controllers arranged on the vehicle, which is not limited in the embodiment.

[0096] S53, if yes, the current control current is not adjusted. In this step, if it is determined in step S52 that the current damping control current is consistent with the target damping control current, the current damping control current is not adjusted, that is, the current damping control current does not need to be adjusted, and the current damping control current is the target damping control current.

[0097] S54, if not, the current damping control current is adjusted to the target damping control current. In this step, if it is determined in step S52 that the current damping control current is not consistent with the target damping control current, the current damping control current needs to be adjusted to the target damping control current, so that the damping control current output by the damping adjustable shock absorber is consistent with the target damping control current.

[0098] Please refer to Figure 8 In step S54, when the current damping control current is adjusted to the target damping control current, steps S541 to S544 are further included:

[0099] S541, obtaining the current driving mode and the road level of the vehicle. In this step, the specific description of the current driving mode and the road level of the vehicle can refer to the related description in step S25421 described above. The obtaining method of the current driving mode and the road level of the vehicle in this step is the same as that in step S25421 described above, which will not be repeated here.

[0100] S542, determine the damping control target current range according to the driving mode and the road surface grade. The damping control target current range includes an upper limit damping control current and a lower limit damping control current. Generally, the vehicle is provided with a corresponding damping interval according to the driving mode and the road surface grade, and the upper limit damping value of the damping interval corresponds to the upper limit damping control current, and the lower limit damping value of the damping interval corresponds to the lower limit damping control current.

[0101] S543, if the target damping control current is within the damping control target current range, output the target damping control current. In this step, when the corresponding driving mode and the road surface grade are determined, the target damping of the damping adjustable shock absorber corresponds to the target damping control current when output, and it is necessary to judge whether the target damping control current is within the damping control target current range. If the target damping control current is within the damping control target current range, the target damping control current is output.

[0102] S544, if the target damping control current is out of the damping control target current range, output the upper limit value or the lower limit value of the damping control target current. If the target damping control current is less than the lower limit damping control current, directly output the lower limit damping control current. If the target damping control current is greater than the upper limit damping control current, directly output the upper limit damping control current. In this way, the probability of damping adjustable shock absorber damping adjustment error caused by target damping control current calculation error can be reduced, not only the related electrical elements can be better protected from being damaged, but also the accuracy of damping adjustable shock absorber damping adjustment during the operation of the vehicle air suspension can be improved.

[0103] In an embodiment of the present application, please refer to Figure 9 Before step S1 is executed, it is judged whether there is a fault in each component of the vehicle air suspension. If there is a fault in one of the components, step S1 is not executed, and a default control current is output. The default control current can be displayed on the display screen of the vehicle, or the default control current can be converted into a corresponding alarm signal output to remind the vehicle driver to pay attention. The output default control current can be a digital zero, or a preset arbitrary value easy to identify, etc.

[0104] It should be noted that the target stiffness control current, the current stiffness control current, the target damping control current and the current damping control current in the above steps can also be displayed on the display screen of the vehicle or other additionally provided display panels, so that the stiffness and damping of the vehicle air suspension can be conveniently and timely viewed, so that whether the stiffness and damping adjustment is normal can be timely found out.

[0105] Please refer to Figure 10In a second aspect, the present application provides a control system 100 of a vehicle air suspension, the vehicle air suspension comprising a plurality of multi-chamber air springs and a plurality of adjustable damping shock absorbers, one multi-chamber air spring and one adjustable damping shock absorber are arranged at each mounting position of a vehicle wheel, the multi-chamber air spring has a plurality of stiffness gears, the adjustable damping shock absorber has adjustable damping, the control system comprises: an acquisition module 110, a stiffness adjustment module 120, a spring force calculation module 130, a damping force calculation module 140, and a damping adjustment module 150; the acquisition module 110 is configured to acquire a target torque and a target hop control force of the vehicle air suspension; the stiffness adjustment module 120 is configured to determine a target stiffness gear of the multi-chamber air spring according to the target torque, and adjust the current stiffness gear of all multi-chamber air springs to the target stiffness gear; the spring force calculation module 130 is configured to calculate a target spring force of a single multi-chamber air spring under the target stiffness gear; the damping force calculation module 140 is configured to calculate a target damping force of a single adjustable damping shock absorber according to the target torque, the target hop control force, and the target spring force; and the damping adjustment module 150 is configured to adjust the current damping force of the adjustable damping shock absorber to the target damping force.

[0106] It should be noted that the control method and the control system of the vehicle air suspension provided in the above embodiments belong to the same concept, and the specific manner in which each module performs an operation has been described in detail in the method embodiments, which will not be described here. In actual application, the control system provided in the above embodiments can be divided into different functional modules according to the need, i.e., the internal structure of the control system is divided into different functional modules to complete all or part of the functions described above, and this is not limited herein.

[0107] In a third aspect, the present application provides an electronic device, please refer to Figure 11 The electronic device 1 can include a memory 12, a processor 13, and a bus, and can further include a computer program stored in the memory 12 and executable on the processor 13, the computer program being configured to perform the following processes: acquiring a target torque and a target hop control force of a vehicle air suspension; determining a target stiffness gear of a multi-chamber air spring according to the target torque, and adjusting the current stiffness gear of all multi-chamber air springs to the target stiffness gear; determining the total target output air spring torque and the total target air spring hop control force of all multi-chamber air springs under the target stiffness gear according to the target stiffness gear; calculating a target damping force of a single adjustable damping shock absorber according to the target torque and the target hop control force; and adjusting the current damping force of the adjustable damping shock absorber to the target damping force.

[0108] The memory 12 includes at least one type of readable storage medium, such as a flash memory, a mobile hard disk, a multimedia card, a card-type memory (e.g., an SD or DX memory, etc.), a magnetic memory, a disk, an optical disk, etc. The memory 12 can be an internal storage unit of the electronic device 1 in some embodiments, such as a mobile hard disk of the electronic device 1. The memory 12 can be used to not only store application software and various data installed in the electronic device 1, such as control codes of a vehicle air suspension, but also temporarily store data that has been output or will be output.

[0109] The processor 13 can be composed of an integrated circuit in some embodiments, such as a single packaged integrated circuit or a plurality of packaged integrated circuits with the same or different functions, including one or more combinations of a central processing unit (CPU), a microprocessor, a digital processing chip, a graphics processor, and various control chips, etc. The processor 13 is a control unit of the electronic device 1, which connects various components of the entire electronic device 1 through various interfaces and lines, and executes various functions and processes data of the electronic device 1 by running or executing programs or modules stored in the memory 12 (such as a control program of the suspension, etc.) and calling data stored in the memory 12.

[0110] The processor 13 executes an operating system of the electronic device 1 and various installed application programs. The processor 13 executes the application programs to implement the steps in the above-mentioned engine load prediction method.

[0111] For example, the computer program can be divided into one or more modules, which are stored in the memory 12 and executed by the processor 13 to complete the present application. One or more modules can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program in the electronic device 1. For example, the computer program can be divided into a system control target acquisition module, an air spring system stiffness adjustment module, an air spring system output determination module, a damping control system output calculation module, and a damping control system damping adjustment module.

[0112] The integrated units implemented in the form of the above-mentioned software function modules can be stored in a computer readable storage medium, which can be non-volatile or volatile. The above-mentioned software function modules stored in a storage medium include a plurality of instructions for causing a computer device (which can be a personal computer, a computer device, or a network device, etc.) or a processor to execute part of the functions of the suspension control method of each embodiment of the present application.

[0113] A fourth aspect of the present application provides a computer-readable storage medium, having stored thereon a computer program, which, when executed by a processor of a computer, causes the computer to perform the control method of any one of the above.

[0114] In summary, the control method, control system, device and medium of the vehicle air suspension of the present application can determine the target stiffness gear of the multi-cavity air spring according to the target control torque and the jump control force of the vehicle air suspension, and adjust the current stiffness gear of all multi-cavity air springs to the target stiffness gear; calculate the target spring force of a single multi-cavity air spring under the target stiffness gear; calculate the target damping force of a single damping adjustable shock absorber according to the target torque, the target jump control force and the target spring force; and adjust the current damping force of the damping adjustable shock absorber to the target damping force. The above control method can establish a connection between the stiffness adjustment of the multi-cavity air spring and the damping force adjustment of the damping adjustable shock absorber, realize the coordinated control between the damping force and the spring stiffness under dynamic working conditions, and thus improve the comfort and control stability of the vehicle during the driving process. Therefore, the present application effectively overcomes the various shortcomings in the prior art and has high industrial utilization value.

[0115] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. A control method of a vehicle air suspension including a plurality of multi-chambered air springs having a plurality of stiffness notches and a plurality of damper-adjustable shock absorbers whose dampings are continuously adjustable, characterized by, The control method comprises: obtaining a target torque and a target bounce control force of the vehicle air suspension; determining a target stiffness gear of the multi-cavity air spring according to the target torque, and adjusting the current stiffness gear of all the multi-cavity air springs to the target stiffness gear; calculating a target spring force of a single multi-cavity air spring under the target stiffness gear; calculating a target damping force of a single damping adjustable shock absorber according to the target torque, the target bounce control force and the target spring force; wherein the target torque comprises a target pitch torque and a target roll torque of the vehicle air suspension; the target bounce control force refers to a force for controlling the bounce or vibration of the vehicle when encountering uneven road or other impact during driving; adjusting the current damping force of the damping adjustable shock absorber to the target damping force; determining a target stiffness gear of the multi-cavity air spring according to the target torque, and adjusting the current stiffness gear of all the multi-cavity air springs to the target stiffness gear, comprising: calculating a single estimated output air spring force of all the multi-cavity air springs under a plurality of stiffness gears; calculating an estimated output air spring torque generated by all the multi-cavity air springs under each stiffness gear according to the single estimated output air spring force; respectively calculating the difference between the estimated output air spring torque generated by all the multi-cavity air springs under each stiffness gear and the target torque; selecting the stiffness gear corresponding to the estimated output air spring torque with the smallest difference with the target torque as the target stiffness gear; adjusting the current stiffness gear of all the multi-cavity air springs to the target stiffness gear; adjusting the current stiffness gear of all the multi-cavity air springs to the target stiffness gear, comprising: obtaining the current stiffness gear of the multi-cavity air spring; determining whether the current stiffness gear is consistent with the target stiffness gear; if yes, the current stiffness gear is not adjusted; if not, the current stiffness gear is adjusted to the target stiffness gear; adjusting the current stiffness gear to the target stiffness gear, comprising: adjusting the current stiffness control current to the target stiffness control current; adjusting the current stiffness control current to the target stiffness control current, comprising: obtaining the current driving mode and the road level of the vehicle; determining a stiffness control target current range according to the driving mode and the road level; if the target stiffness control current is within the stiffness control target current range, outputting the target stiffness control current; if the target stiffness control current is out of the stiffness control target current range, outputting the upper limit value or the lower limit value of the stiffness control target current range.

2. The control method according to claim 1, characterized by, adjusting the current stiffness gear to the target stiffness gear, further comprising: obtaining the opening and closing states of a plurality of stiffness adjustment valves corresponding to the current stiffness gear, and determining the current stiffness control current of the plurality of stiffness adjustment valves according to the opening and closing states; wherein the multi-cavity air spring comprises a plurality of stiffness adjustment valves, and the opening and closing combination states of the plurality of stiffness adjustment valves correspond to a plurality of stiffness gears.

3. The control method according to claim 1, characterized by, Adjusting the current damping force to the target damping force, comprising: Obtaining a current damping control current corresponding to the current damping force and a target damping control current corresponding to the target damping force; Determining whether the current damping control current is consistent with the target damping control current; If yes, not adjusting the current damping control current; If no, adjusting the current damping control current to the target damping control current; The damping-adjustable shock absorber comprises a damping adjustment valve, and the size of the damping control current of the damping adjustment valve corresponds to the size of the damping force.

4. The control method according to claim 3, characterized by Adjusting the current damping control current to the target damping control current, comprising: Obtaining a current driving mode and a road surface level of the vehicle; Determining a damping control target current range according to the driving mode and the road surface level; If the target damping control current is within the damping control target current range, outputting the target damping control current; If the target damping control current is beyond the damping control target current range, outputting an upper limit value or a lower limit value of the damping control target current.

5. A control system for a vehicle air suspension, characterised in that, The control system adopts the control method of any one of claims 1 to 4; the vehicle air suspension comprises a plurality of multi-cavity air springs and a plurality of damping-adjustable shock absorbers, the multi-cavity air springs have a plurality of stiffness gears, the damping of the damping-adjustable shock absorbers is continuously adjustable, and the control system comprises: An obtaining module for obtaining a target torque and a target jump control force of the vehicle air suspension; A stiffness adjustment module for determining a target stiffness gear of the multi-cavity air spring according to the target torque, and adjusting the current stiffness gears of all the multi-cavity air springs to the target stiffness gear; A spring force calculation module for calculating a target spring force of a single multi-cavity air spring under the target stiffness gear; A damping force calculation module for calculating a target damping force of a single damping-adjustable shock absorber according to the target torque, the target jump control force and the target spring force; A damping adjustment module for adjusting the current damping force of the damping-adjustable shock absorber to the target damping force.

6. An electronic device, comprising: The electronic device comprises: One or more processors; A storage device for storing one or more programs, which, when executed by the one or more processors, cause the electronic device to implement the control method of any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, A computer program is stored thereon, which, when executed by a processor of a computer, causes the computer to perform the control method of any one of claims 1 to 4.

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