Control method, control system and equipment of vehicle air suspension and medium

Abstract

The invention provides a control method, control system and equipment for a vehicle air suspension and a medium. The control method comprises the steps that the target torque and the target jumping control force of the vehicle air suspension are obtained; according to the target torque, target rigidity gears of the multi-cavity air springs are determined, and the current rigidity gears of all the multi-cavity air springs are adjusted to the target rigidity gears; the target spring force of the single multi-cavity air spring under the target rigidity gear is calculated; according to the target torque, the target jump control force and the target spring force, the target damping force of the single damping-adjustable shock absorber is calculated; and the current damping force of the damping-adjustable shock absorber is adjusted to the target damping force. According to the control method, cooperative control over the damping force and the rigidity in the vehicle air suspension can be achieved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle air suspension control, and in particular to a vehicle air suspension control method, control system, equipment and medium. Background Art

[0002] With the continuous improvement of consumers' demand for automobile comfort and the development of related industrial technologies, multi-chamber air suspension has been increasingly widely used in today's automobile market. Since the multi-chamber air suspension system includes multi-chamber air springs and adjustable damping shock absorbers, it can have the functions of damping adjustment of adjustable damping shock absorbers, vehicle height control and spring stiffness adjustment. The control method of the multi-chamber air suspension directly affects the adjustment effect of the damping of the adjustable damping shock absorber and the stiffness of the air spring, which in turn affects the driving comfort and handling stability.

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

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

[0005] The first aspect of the present invention is to provide a control method for a vehicle air suspension, wherein the vehicle air suspension includes multiple multi-chamber air springs and multiple damping-adjustable shock absorbers, the multi-chamber air springs have multiple stiffness levels, and the damping of the damping-adjustable shock absorbers is continuously adjustable; the control method includes: obtaining a target torque and a target jump control force of the vehicle air suspension; determining a target stiffness level of the multi-chamber air spring according to the target torque, and adjusting the current stiffness levels of all multi-chamber air springs to the target stiffness level; calculating a target spring force of a single multi-chamber air spring at the target stiffness level; 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; and adjusting the current damping force of the damping-adjustable shock absorber to the target damping force.

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

[0007] In an example of the control method of the present invention, a target stiffness level of a multi-chamber air spring is determined according to a target torque, and the current stiffness levels of all multi-chamber air springs are adjusted to the target stiffness level, including: calculating a single estimated output air spring force of all multi-chamber air springs at multiple stiffness levels; calculating an estimated output air spring torque generated by all multi-chamber air springs at each stiffness level based on the single estimated output air spring force; calculating the difference between the estimated output air spring torque generated by all multi-chamber air springs at each stiffness level and the target torque; selecting the stiffness level corresponding to the estimated output air spring torque with the smallest difference with the target torque as the target stiffness level; and adjusting the current stiffness levels of all multi-chamber air springs to the target stiffness level.

[0008] In one example of the control method of the present invention, the current stiffness levels of all multi-chamber air springs are adjusted to the target stiffness levels, including: obtaining the current stiffness level of the multi-chamber air spring; determining whether the current stiffness level is consistent with the target stiffness level; if so, not adjusting the current stiffness level; if not, adjusting the current stiffness level to the target stiffness level.

[0009] In an example of the control method of the present invention, the multi-chamber air spring includes multiple stiffness regulating valves, and the opening and closing combination states of the multiple stiffness regulating valves correspond to multiple stiffness gears; adjusting the current stiffness gear to the target stiffness gear includes: obtaining the opening and closing states of the multiple stiffness regulating valves corresponding to the current stiffness gear, and determining the current stiffness control current of the multiple stiffness regulating valves according to the opening and closing states; adjusting the current stiffness control current to the target stiffness control current.

[0010] In an example of the control method of the present invention, the current stiffness control current is adjusted to the target stiffness control current, including: obtaining the current driving mode and road surface grade of the vehicle; determining the stiffness control target current range according to the driving mode and the road surface grade; 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 exceeds the stiffness control target current range, outputting the upper limit value or lower limit value of the stiffness control target current range.

[0011] In an example of the control method of the present invention, the damping adjustable shock absorber includes a damping regulating valve, and the magnitude of the damping control current of the damping regulating valve corresponds to the magnitude of the damping force; adjusting the current damping force to the target damping force includes:

[0012] Obtain the current damping control current corresponding to the current damping force and the target damping control current corresponding to the target damping force; determine whether the current damping control current is consistent with the target damping control current; if so, do not adjust the current damping control current; if not, adjust the current damping control current to the target damping control current.

[0013] In an example of the control method of the present invention, the current damping control current is adjusted to the target damping control current, including: obtaining the current driving mode and road surface grade of the vehicle; determining the damping control target current range according to the driving mode and road surface grade; 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 exceeds the damping control target current range, outputting the upper limit value or lower limit value of the damping control target current.

[0014] The second aspect of the present invention is to provide a control system for a vehicle air suspension, wherein the vehicle air suspension includes multiple multi-chamber air springs and multiple damping-adjustable shock absorbers, the multi-chamber air springs have multiple stiffness levels, and the damping of the damping-adjustable shock absorbers is continuously adjustable; the control system includes: an acquisition module, an adjustment module, a spring force calculation module, a damping force calculation module and a damping adjustment module; the acquisition module is used to obtain the target torque and target jump control force of the vehicle air suspension; the stiffness adjustment module is used to determine the target stiffness level of the multi-chamber air spring according to the target torque, and adjust the current stiffness levels of all multi-chamber air springs to the target stiffness level; the spring force calculation module is used to calculate the target spring force of a single multi-chamber air spring under the target stiffness level; the damping force calculation module is used to calculate the target damping force of a single damping-adjustable shock absorber according to the target torque and the target jump control force; the damping adjustment module is used to adjust the current damping force of the damping-adjustable shock absorber to the target damping force.

[0015] The third aspect of the present invention is to provide an electronic device, the electronic device comprising: a storage device and one or more processors. The storage device is used to store one or more programs, and when the one or more programs are executed by one or more processors, the electronic device implements any of the above control methods.

[0016] A fourth aspect of the present invention is to provide a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor of a computer, the computer executes any one of the control methods described above.

[0017] The control method, control system, equipment and medium of the vehicle air suspension of the present invention can determine the target stiffness gear of the multi-chamber air spring according to the target torque through the target control torque and jump control force of the vehicle air suspension, and adjust the current stiffness gear of all multi-chamber air springs to the target stiffness gear; calculate the target spring force of a single multi-chamber 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; 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-chamber 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 conditions, thereby improving the comfort and handling stability of the vehicle during driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic flow chart of a method for controlling a vehicle air suspension according to an embodiment of the present invention;

[0019] Figure 2 A partial flow chart of step S2 provided in one embodiment of the present invention;

[0020] Figure 3 A partial flow chart of step S25 provided in one embodiment of the present invention;

[0021] Figure 4 A schematic diagram of a flow chart of step S254 provided in one embodiment of the present invention;

[0022] Figure 5 A flowchart of step S2542 provided in accordance with an embodiment of the present invention;

[0023] Figure 6 A schematic diagram of a mechanical model of a vehicle air suspension according to an embodiment of the present invention;

[0024] Figure 7 A schematic flow chart of step S5 provided in accordance with an embodiment of the present invention;

[0025] Figure 8 A schematic flow chart of step S54 provided in accordance with an embodiment of the present invention;

[0026] Fig. 9 A logic flow chart of a method for controlling a vehicle air suspension provided by an embodiment of the present invention;

[0027] Fig.10 A structural block diagram of a control system for a vehicle air suspension provided by an embodiment of the present invention;

[0028] Fig.11 The figure is a schematic diagram of the structure of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0030] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0031] In the following description, numerous details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it is obvious to those skilled in the art that the embodiments of the present invention can be implemented without these specific details. 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 present invention difficult to understand.

[0032] Vehicle air suspension is an important part of the car. It connects the wheels and the body, and is mainly responsible for absorbing the impact and vibration caused by uneven roads, and maintaining the stability and comfort of the vehicle during driving. With the development of automobile technology, the vehicle air suspension control system is becoming more and more advanced. Among them, the vehicle air suspension contains a multi-chamber air spring system and a damping adjustable shock absorption system, so it can have the functions of damping adjustable shock absorber damping, body height and spring stiffness adjustment, etc., and is currently being used more and more in automobiles.

[0033] The applicant found that in the existing vehicle air suspension control method, the stiffness control of the multi-chamber air spring system and the damping control of the damping adjustable shock absorber system are basically independent of each other. Therefore, during the vehicle driving process, the coordinated control of the stiffness and damping of the vehicle air suspension is often not achieved, which in turn limits the improvement of the comfort and handling stability during the vehicle driving process. In view of this, the applicant conducted corresponding research and provided a vehicle air suspension control method, control system, equipment and medium. The control method can establish a connection between the stiffness adjustment of the multi-chamber air spring system and the damping adjustment of the damping adjustable shock absorber, and achieve the coordinated control between the stiffness and damping of the vehicle air suspension under dynamic conditions, so as to obtain better comfort and handling stability during the vehicle driving process.

[0034] The vehicle air suspension in the embodiment of the present invention includes a plurality of multi-chamber air springs and a plurality of adjustable damping shock absorbers. The multi-chamber air springs and the adjustable damping shock absorbers play a supporting and guiding role in the vehicle air suspension system, ensuring that the wheels of the vehicle can move according to the designed trajectory while absorbing and transmitting the force and torque from the road surface. The multi-chamber air springs and the adjustable damping shock absorbers are usually set in a one-to-one correspondence, that is, one multi-chamber air spring and one adjustable damping shock absorber are used in combination. The number of multi-chamber air springs and adjustable damping shock absorbers usually matches the number of tires of the vehicle. Passenger cars usually have four multi-chamber air springs and four adjustable damping shock absorbers, while special vehicles may differ according to the number of tires.

[0035] Considering that most passenger cars (such as sedans, SUVs, MPVs, etc.) equipped with multi-chamber air spring systems usually have four wheels, there are four multi-chamber springs and four damping adjustable shock absorbers, and each wheel corresponds to a multi-chamber spring and a damping adjustable shock absorber. The multi-chamber air spring and the damping adjustable shock absorber 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 invention, four multi-chamber springs and four damping adjustable shock absorbers are used as examples. The above-mentioned four multi-chamber springs and four damping adjustable shock absorbers correspond to the four wheels of the vehicle respectively, and are distributed on the front left side, the front right side, the rear left side and the rear right side of the vehicle. The multi-chamber air spring has multiple stiffness gears, for example, two stiffness gears, three stiffness gears, four stiffness gears, etc. It should be noted that during the normal operation of the vehicle air suspension, the current stiffness gears of the multiple multi-chamber air springs are always consistent.

[0036] See also Figure 1 and Figure 8 , the control method includes the following processes:

[0037] S1. Obtaining a target torque and a target jumping control force of the vehicle air suspension;

[0038] S2. Determine a target stiffness level of the multi-chamber air spring according to the target torque, and adjust the current stiffness levels of all the multi-chamber air springs to the target stiffness level;

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

[0040] S4, 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;

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

[0042] The above control method can determine the target stiffness level of the multi-chamber air spring through the target control torque and jump control force of the vehicle air suspension, and adjust the current stiffness level of all multi-chamber air springs to the target stiffness level; calculate the target spring force of a single multi-chamber air spring under the target stiffness level; calculate the target damping force of a single damping adjustable shock absorber according to the target torque, target jump control force and 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-chamber air spring and the damping force adjustment of the damping adjustable shock absorber, and realize the coordinated control between the damping force and the spring stiffness under dynamic conditions, thereby improving the comfort and handling stability of the vehicle during driving.

[0043] The following is a detailed description of each step.

[0044] S1. Obtain the target control torque and target jump control force of the vehicle air suspension. In this step, the target control torque of the vehicle air suspension includes the vehicle roll target control torque and the vehicle pitch target control torque generated during the vehicle's driving process. 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, target pitch torque and target jump control force of the vehicle. Preferably, in this embodiment, the vehicle body is equipped with a six-axis inertial sensor and a vehicle body height sensor, and the vehicle body pitch angular velocity v can be calculated by the six-axis inertial sensor. pitch and body roll attitude v roll , the vertical jumping speed v of the vehicle body can be calculated based on the vehicle body height sensor heave Finally, according to the vehicle body pitch angular velocity v pitch 、Body roll posture v roll and the vertical jumping speed v heave , the target roll torque, target pitch torque and target jump control force of the vehicle can be calculated. In the present embodiment, since the vehicle height sensor and the six-axis inertial sensor are components originally installed on the vehicle to achieve driving control, there is no need to set up additional sensor components to achieve the control method in the present embodiment, which can save the number of vehicle parts and further 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 also be replaced by three single acceleration sensors that can measure the vehicle height, the longitudinal direction of the vehicle body or the lateral direction of the vehicle body. In the present embodiment, the target jump control force of the vehicle air suspension refers to the force in the vehicle air suspension used to control the bounce or vibration of the vehicle when it encounters uneven roads or other impacts during driving.

[0045] S2. According to the target torque, determine the target stiffness level of the multi-chamber air spring, and adjust the current stiffness levels of all the multi-chamber air springs to the target stiffness level. In this step, the multi-chamber air spring corresponds to different output torques at different stiffness levels. Determining the target stiffness level of the multi-chamber air spring according to the target torque means that by comparing and judging the output torque of the multi-chamber air spring at different stiffness levels and the target torque, the stiffness level when the output torque of the multi-chamber air spring is closest to the target torque is determined as the target stiffness level. It should be noted that the output torque of the multi-chamber air spring in this embodiment refers to the sum of the output torques generated by all multi-chamber air springs. At the same time, on the vehicle air suspension, all multi-chamber air springs always operate at the same stiffness level.

[0046] See also Figure 2 In an embodiment of the control method of the present invention, in step S2, according to the target torque, the target stiffness level of the multi-cavity air spring is determined, and the current stiffness levels of all the multi-cavity air springs are adjusted to the target stiffness level, specifically including steps S21 to S25:

[0047] S21. Calculate the single estimated output air spring force of all multi-chamber air springs under the multiple stiffness gears. In this step, the specific calculation process of the single estimated output air spring force is: first, obtain the compression or extension of a single multi-chamber air spring through the height sensor installed on the vehicle, that is, obtain the displacement change rate Δx of the multi-chamber air spring; secondly, obtain the air pressure Px of each multi-chamber air spring through the pressure sensor installed on the multi-chamber air spring; finally, according to the current stiffness gear, the displacement change rate Δx and the air pressure Px, interpolate and read the spring force Fx of the corresponding air spring from the stiffness-displacement characteristic curve corresponding to the multi-chamber air spring. According to the above steps, the single estimated output air spring force of all multi-chamber air springs under the current stiffness gear can be calculated respectively. For other stiffness gears, the spring force calculation method of the multi-chamber air spring is the same.

[0048] S22, calculating the estimated output air spring torque generated by all multi-chamber air springs at each stiffness level according to the single estimated output air spring force. For example, when the multi-chamber air spring has three stiffness levels, the different estimated output air spring torques N1, N2 and N3 generated by all multi-chamber air springs at the first stiffness level, the second stiffness level and the third stiffness level are calculated respectively.

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

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

[0051] S25. Adjust the current stiffness levels of all the multi-chamber air springs to the target stiffness level.

[0052] See also Figure 3 and Figure 8 In this step S25, the current stiffness levels of all multi-chamber air springs are adjusted to the target stiffness levels, which specifically includes the following steps S251 to S254:

[0053] S251, obtaining the current stiffness level of the multi-cavity air spring. In this step, the current stiffness level of the multi-cavity air spring can be read by a controller on the vehicle, or the vehicle can be provided with a current stiffness level display device, and the current stiffness level of the multi-cavity air spring can be read from the current stiffness level display device.

[0054] S252, determine whether the current stiffness level is consistent with the target stiffness level. In this step, the stiffness level obtained in step S251 is compared with the target stiffness level. The comparison method is not limited, and can be determined by comparing the output control current corresponding to different stiffness levels, or by comparing the closed state of the switch valve corresponding to different stiffness levels.

[0055] S253, if yes, then the current stiffness level is not adjusted. In this step, if step S252 determines that the current stiffness level is consistent with the target stiffness level, the current stiffness level is used as the target stiffness level, that is, the target stiffness level adjustment of all multi-cavity air springs is completed. This can simplify the control calculation steps of stiffness adjustment and improve the efficiency of stiffness adjustment.

[0056] S254: If not, adjust the current stiffness level to the target stiffness level. In this step, if step S252 determines that the current stiffness level is inconsistent with the target stiffness level, the current stiffness levels of all multi-cavity air springs need to be adjusted to the target stiffness level, thereby completing the adjustment of the target stiffness levels of all multi-cavity air springs.

[0057] In order to adjust the stiffness of the multi-chamber air spring, the multi-chamber air spring is provided with multiple stiffness regulating valves, so as to adjust different stiffness levels by controlling the on and off between different cavities. The number of stiffness regulating valves is related to the number of stiffness levels, and the specific number is set to meet the stiffness level adjustment requirements. The stiffness regulating valve can be mechanically adjusted, electromagnetically controlled, etc. Preferably, in this embodiment, the stiffness regulating valve is electromagnetically controlled. The open and closed combination states of the multiple stiffness regulating valves correspond to the multiple stiffness levels. Please refer to Figure 4 and Figure 8 In an embodiment of the control method of the present invention, in step S254, adjusting the current stiffness level to the target stiffness level includes the following steps S2541 to S2542:

[0058] S2541, obtaining the opening and closing states of multiple stiffness regulating valves corresponding to the current stiffness gear, and determining the current stiffness control currents of the multiple stiffness regulating valves according to the opening and closing states. In this step, the current stiffness control current of the corresponding stiffness regulating valve can be found by judging the current opening and closing states of the stiffness regulating valves.

[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 may 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 is completed by closing the button corresponding to the current stiffness control current and opening the button corresponding to the target stiffness control current. Alternatively, the vehicle controller may store a plurality of control programs corresponding to different control currents in its internal program, and the operation of adjusting the current stiffness control current to the target stiffness control current is completed by running different control programs.

[0060] See also Figure 5 and Figure 8 In an embodiment of the control method of the present invention, adjusting the current stiffness control current to the target stiffness control current includes steps S25421 to S25424:

[0061] S25421. Obtain the current driving mode and road grade of the vehicle. Common driving modes of the vehicle include standard mode, economic mode, sports mode, off-road mode, etc. Different driving modes can be preset for different vehicle types. Different driving modes of the vehicle generally require different stiffness and damping of the vehicle air suspension. For example, in comfort mode, the vehicle usually pursues a smooth and quiet riding experience. The stiffness of the vehicle air spring is generally set to be softer, and the damping force is also adjusted to be lower accordingly to better cope with the impact caused by bumps and unevenness of the road. In sports mode, the stiffness of the vehicle air spring is usually increased to provide better lateral support and vehicle handling. The damping will also be increased accordingly to reduce the tilt and swing of the vehicle body when turning and improve the response speed of the vehicle. Road grades generally include asphalt roads, Belgian roads, gravel roads and undulating roads. When the vehicle air suspension is driving on roads of different road grades, the stiffness of the corresponding vehicle air spring and the damping of the shock absorber will also be different. The vehicle's current driving mode and current road surface grade can usually be acquired through the vehicle's sensors and control systems, such as detecting the vehicle's driving status through wheel acceleration sensors, body acceleration sensors, height sensors, wheel speed sensors, etc., and the vehicle's electronic control unit (ECU) or advanced driver assistance system (ADAS) 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 grade. The stiffness control target current range includes an upper stiffness control current limit and a lower stiffness control current limit. Generally, a vehicle is usually provided with a corresponding stiffness interval according to the driving mode and the road surface grade. The stiffness interval corresponds to a stiffness control target current range. The stiffness upper limit value and the stiffness lower limit value corresponding to the stiffness interval correspond to the upper stiffness control current limit and the lower stiffness control current limit, respectively. That is, when the vehicle is in a certain driving mode and a certain road surface grade, the stiffness target control current of the corresponding vehicle air suspension at this time 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, then the target stiffness control current is output. In this step, when the corresponding driving mode and road surface grade are determined, before the target stiffness control current corresponding to the target stiffness of the multi-chamber air spring is output, it is necessary to first check whether the target stiffness control current is within the stiffness control target current range. If the target stiffness control current is within the stiffness control target current range, then the target stiffness control current is output.

[0064] S25424. If the target stiffness control current exceeds the stiffness control target current range, the upper limit or lower limit of the stiffness control target current range is output. In this step, if the target stiffness control current is less than the lower limit stiffness control current, the lower limit stiffness control current is directly output; if the target stiffness control current is greater than the upper limit stiffness control current, the upper limit stiffness control current is directly output. This setting can reduce the probability of multi-cavity air spring stiffness adjustment errors caused by incorrect calculation of the target stiffness control current, which can not only effectively protect related electrical components, but also improve the accuracy of multi-cavity air spring stiffness adjustment during the operation of the vehicle air suspension.

[0065] S3, calculate the target spring force of a single multi-cavity air spring under the target stiffness gear. After adjusting the current stiffness gear of all the multi-cavity air springs to the target stiffness gear in step S25, the target stiffness of multiple multi-cavity air springs can be obtained at this time. According to the target stiffness, the displacement change rate Δx of each multi-cavity air spring and the air pressure Px of each multi-cavity air spring are obtained again at this moment; and the stiffness coefficient k of the corresponding multi-cavity air spring is interpolated and read again from the stiffness-displacement characteristic curve corresponding to the multi-cavity air spring, and the target spring force of each multi-cavity air spring is calculated accordingly. Specifically, in this embodiment, there are four multi-cavity air springs, that is, four displacement change rates Δx need to be known, which are marked as Δx1, Δx2, Δx3 and Δx4 respectively. And according to the stiffness-displacement characteristic curve corresponding to the multi-cavity air spring, four stiffness coefficients k are found, which are marked as k1, k2, k3 and k4 respectively. According to the stiffness coefficient k and the change rate Δx, the target stiffness gears of the four multi-cavity air springs can be calculated respectively.

[0066] There are many ways to adjust the damping of the adjustable damping shock absorber, such as manual adjustment, which is common, and the damping adjustment is achieved by manually changing the opening size of the valve inside the adjustable damping shock absorber. It can also be hydraulic adjustment, and the damping size is adjusted by changing the flow rate of the hydraulic oil inside the adjustable damping shock absorber. It can also be achieved by controlling the opening of the solenoid valve by the current size of the solenoid valve to adjust the gas flow or hydraulic oil flow inside the adjustable damping shock absorber, thereby achieving the adjustment of the damping force of the shock absorber. In this embodiment, the adjustable damping shock absorber includes a damping regulating valve, and the damping control current size of the damping regulating valve corresponds to the damping force size. The corresponding relationship between the damping control current and the damping force is not limited, and can be a linear proportional relationship, or a corresponding relationship that satisfies a specific function, etc. In actual application, the corresponding relationship between the damping control current and the damping force is an inherent parameter of each adjustable damping shock absorber, which can be obtained from the selection parameter table or instruction manual of the adjustable damping shock absorber. Preferably, in this embodiment, the damping regulating valve is set as a proportional valve to achieve continuous adjustment of the damping of the adjustable damping shock absorber.

[0067] S4, calculating the 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. In this step, the target damping force of a single adjustable damping shock absorber is calculated according to the target torque, the target jump control force and the target spring force. The specific calculation process is as follows (taking 4 multi-chamber air springs and 4 adjustable damping shock absorbers as an example on the vehicle air suspension): Figure 6 The figure shows the mechanical model of the vehicle air suspension. Figure 6 The mechanical analysis shown in the figure gives the following calculation formula:

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

[0069] Vehicle pitch motion equation: This is marked as Formula 2.

[0070] The equation of motion for vehicle body roll is: This is labeled as Formula 3.

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

[0072]

[0073] Assuming that the torque of the Roll posture is provided by the front and rear axles in a 1:1 ratio, the above motion equations 1, 2, and 3 can be modified as follows:

[0074]

[0075] Among them, F1, F2, F3, F4, the forces of the 4 suspension assemblies (spring force + damping force);

[0076] k1, k2, k3, k4, the spring stiffness of the 4 multi-chamber air springs;

[0077] c1, c2, c3, c4, the damping coefficients of the 4 adjustable damping shock absorbers;

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

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

[0080] The vertical movement speed of the vehicle body at the four shock absorber positions;

[0081] 4. Vertical moving speed of the wheels;

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

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

[0084] F Heave : Target jump control;

[0085] I θ : moment of inertia;

[0086] Pitch angular acceleration;

[0087] Roll angular acceleration;

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

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

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

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

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

[0093] In step S5, adjusting the current damping force to the target damping force specifically refers to adjusting the current damping force of each of the adjustable damping shock absorbers to the target damping force, see Figure 7 , specifically including steps S51-S54:

[0094] S51, obtaining the current damping control current corresponding to the current damping force and the target damping control current corresponding to the target damping force. In this step, since the magnitude of the damping control current of the damping regulating valve corresponds to the magnitude of the damping force, obtaining the current damping control current means obtaining the current damping control current of the damping regulating valve. Since there is an inherent relationship curve between the magnitude of the damping control current of the damping regulating valve and the damping force, through the relationship curve, on the premise of knowing the target damping force, the target damping control current corresponding to the target damping force can be obtained from the relationship curve.

[0095] S52, judging whether the current damping control current is consistent with the target damping control current. In this step, the vehicle's own controller may judge whether the current damping control current is consistent with the target damping control current, or another controller provided on the vehicle may judge whether the current damping control current is consistent with the target damping control current. In this embodiment, this is not specifically limited.

[0096] S53: If yes, then 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, then the current damping control current is not adjusted, which means that 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, adjusting the current damping control current to the target damping control current. In this step, if it is determined in step S52 that the current damping control current is inconsistent 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 adjustable damping shock absorber is consistent with the target damping control current.

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

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

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

[0101] S543: If the target damping control current is within the damping control target current range, then the target damping control current is output. In this step, when the target damping control current corresponding to the target damping of the adjustable damping shock absorber is output, it is necessary to first determine 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, then the target damping control current is output.

[0102] S544. If the target damping control current exceeds the damping control target current range, the upper limit or lower limit of the damping control target current is output. If the target damping control current is less than the lower limit damping control current, the lower limit damping control current is directly output. If the target damping control current is greater than the upper limit damping control current, the upper limit damping control current is directly output. This arrangement can reduce the probability of error in damping adjustment of the adjustable damping shock absorber due to an error in calculating the target damping control current, which can not only better protect the relevant electrical components from being damaged, but also improve the accuracy of damping adjustment of the adjustable damping shock absorber during the operation of the vehicle air suspension.

[0103] In one embodiment of the present invention, please refer to Fig. 9 Before executing step S1, it is first determined whether there is a fault in each component of the vehicle air suspension. If one of the components is faulty, 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 alert the vehicle driver. The output default control current can be a digital zero, or any preset value that is easy to identify.

[0104] It should be noted that the target stiffness control current, current stiffness control current, target damping control current and current damping control current in the above steps can also be displayed on the vehicle's display screen or other separately provided display panels. This makes it convenient to check the stiffness and damping of the vehicle's air suspension in a timely manner, so as to promptly discover whether the stiffness and damping adjustments are normal.

[0105] See also Fig.10The second aspect of the present invention is to provide a control system 100 for a vehicle air suspension, wherein the vehicle air suspension comprises a plurality of multi-chamber air springs and a plurality of adjustable damping shock absorbers, wherein a multi-chamber air spring and an adjustable damping shock absorber are correspondingly arranged at the installation position of each wheel, wherein the multi-chamber air spring has a plurality of stiffness gears, and the damping of the adjustable damping shock absorber is adjustable, and 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 used to obtain the target torque and target torque of the vehicle air suspension The target jump control force; the stiffness adjustment module 120 is used to determine the target stiffness gear of the multi-chamber air spring according to the target torque, and adjust the current stiffness gears of all the multi-chamber air springs to the target stiffness gear; the spring force calculation module 130 is used to calculate the target spring force of a single multi-chamber air spring under the target stiffness gear; the damping force calculation module 140 is used to 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; the damping adjustment module 150 is used to adjust the current damping force of the damping adjustable shock absorber to the target damping force.

[0106] It should be noted that the control method and control system of the vehicle air suspension provided in the above embodiment belong to the same concept, and the specific manner in which each module performs the operation has been described in detail in the method embodiment, which will not be repeated here. In practical applications, the control system of the vehicle air suspension provided in the above embodiment can allocate the above functions to different functional modules as needed, that is, divide the internal structure of the control system into different functional modules to complete all or part of the functions described above, and this is not limited here.

[0107] The third aspect of the present invention is to provide an electronic device, see Fig.11 The electronic device 1 may include a memory 12, a processor 13 and a bus, and may also include a computer program stored in the memory 12 and executable on the processor 13, the computer program being used to execute the following processes: obtaining a target torque and a target jump control force of the vehicle air suspension; determining a target stiffness level of the multi-chamber air spring according to the target torque, and adjusting the current stiffness levels of all the multi-chamber air springs to the target stiffness level; determining a total target output air spring torque and a total target air spring jump control force of all the multi-chamber air springs at the target stiffness level according to the target stiffness level; calculating a target damping force of a single damping adjustable shock absorber according to the target torque and the target jump control force; and adjusting the current damping force of the damping adjustable shock absorber to the target damping force.

[0108] The memory 12 includes at least one type of readable storage medium, and the readable storage medium includes 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. In some embodiments, the memory 12 may be an internal storage unit of the electronic device 1, such as a mobile hard disk of the electronic device 1. The memory 12 may be used not only to store application software installed in the electronic device 1 and various data, such as a control code of a vehicle air suspension, but also to temporarily store data that has been output or is to be output.

[0109] In some embodiments, the processor 13 may be composed of an integrated circuit, for example, a single packaged integrated circuit, or a plurality of packaged integrated circuits with the same or different functions, including one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and a combination of various control chips. The processor 13 is the control core (Control Unit) of the electronic device 1, and uses various interfaces and lines to connect various components of the entire electronic device 1, and executes or executes programs or modules (such as suspension control programs, etc.) stored in the memory 12, and calls data stored in the memory 12 to execute various functions of the electronic device 1 and process data.

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

[0111] Exemplarily, the computer program can be divided into one or more modules, one or more modules are stored in the memory 12, and are executed by the processor 13 to complete the present application. One or more modules can be a series of computer program instruction segments that can complete specific functions, and the instruction segments 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 above-mentioned integrated unit implemented in the form of a software function module can be stored in a computer-readable storage medium, and the computer-readable storage medium can be non-volatile or volatile. The above-mentioned software function module is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a computer device, or a network device, etc.) or a processor to perform part of the functions of the control method of the suspension of each embodiment of the present application.

[0113] A fourth aspect of the present invention is to provide a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor of a computer, the computer executes any one of the control methods described above.

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

[0115] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A control method for a vehicle air suspension, wherein the vehicle air suspension comprises a plurality of multi-chamber air springs and a plurality of damping adjustable shock absorbers, wherein the multi-chamber air springs have a plurality of stiffness levels, and the damping of the damping adjustable shock absorbers is continuously adjustable, characterized in that: The control method comprises: Obtaining a target torque and a target jumping control force of the vehicle air suspension; Determining a target stiffness level of the multi-chamber air spring according to the target torque, and adjusting the current stiffness levels of all the multi-chamber air springs to the target stiffness level; Calculating the target spring force of a single multi-chamber air spring at the target stiffness gear; 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; The current damping force of the adjustable damping shock absorber is adjusted to the target damping force.

2. The control method according to claim 1, characterized in that: The target torque includes a target pitch torque and a target roll torque of the vehicle air suspension.

3. The control method according to claim 1, characterized in that: Determining a target stiffness level of the multi-chamber air spring according to the target torque, and adjusting current stiffness levels of all the multi-chamber air springs to the target stiffness level, including: calculating a single estimated output air spring force for all multi-chamber air springs at a plurality of said stiffness levels; Calculating an estimated output air spring torque generated by all multi-chamber air springs at each of the stiffness gears according to the single estimated output air spring force; respectively calculating the difference between the estimated output air spring torque generated by all multi-chamber air springs at each of the stiffness gears and the target torque; Selecting the stiffness gear corresponding to the estimated output air spring torque with the smallest difference from the target torque as the target stiffness gear; The current stiffness levels of all the multi-chamber air springs are adjusted to the target stiffness level.

4. The control method according to claim 3, characterized in that: Adjusting the current stiffness levels of all the multi-chamber air springs to the target stiffness level includes: Obtaining a current stiffness level of the multi-chamber air spring; Determining whether the current stiffness level is consistent with the target stiffness level; If yes, then the current stiffness level is not adjusted; If not, the current stiffness level is adjusted to the target stiffness level.

5. The control method according to claim 4, characterized in that: The multi-chamber air spring comprises a plurality of stiffness regulating valves, and the opening and closing combination states of the plurality of stiffness regulating valves correspond to the plurality of stiffness gears; Adjusting the current stiffness level to the target stiffness level includes: Acquiring the opening and closing states of the plurality of stiffness regulating valves corresponding to the current stiffness gear, and determining the current stiffness control currents of the plurality of stiffness regulating valves according to the opening and closing states; The current stiffness control current is adjusted to a target stiffness control current.

6. The control method according to claim 5, characterized in that: Adjusting the current stiffness control current to a target stiffness control current includes: Obtaining the current driving mode and road grade of the vehicle; determining a stiffness control target current range according to the driving mode and the road surface grade; 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 exceeds the stiffness control target current range, an upper limit value or a lower limit value of the stiffness control target current range is output.

7. The control method according to claim 1, characterized in that: The damping adjustable shock absorber comprises a damping regulating valve, and the magnitude of the damping control current of the damping regulating valve corresponds to the magnitude of the damping force; Adjust the current damping force to the target damping force, including: Acquire 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, then the current damping control current is not adjusted; If not, the current damping control current is adjusted to the target damping control current.

8. The control method according to claim 7, characterized in that: Adjusting the current damping control current to the target damping control current includes: Obtaining the current driving mode and road grade of the vehicle; determining a damping control target current range according to the driving mode and the road surface grade; 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 exceeds the damping control target current range, an upper limit value or a lower limit value of the damping control target current is output.

9. A control system for a vehicle air suspension, the vehicle air suspension comprising a plurality of multi-chamber air springs and a plurality of adjustable damping shock absorbers, the multi-chamber air springs having a plurality of stiffness levels, the damping of the adjustable damping shock absorbers being continuously adjustable, characterized in that: The control system comprises: An acquisition module, used for acquiring a target torque and a target jumping control force of the vehicle air suspension; A stiffness adjustment module, used for determining a target stiffness level of the multi-cavity air spring according to the target torque, and adjusting the current stiffness levels of all the multi-cavity air springs to the target stiffness level; A spring force calculation module, used to calculate the target spring force of a single multi-chamber air spring at the target stiffness gear; a damping force calculation module, used 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; The damping adjustment module adjusts the current damping force of the damping adjustable shock absorber to the target damping force.

10. An electronic device, characterized in that: The electronic device comprises: one or more processors; A storage device for storing one or more programs, when the one or more programs are executed by the one or more processors, enables the electronic device to implement the control method as described in any one of claims 1 to 9.

11. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed by a processor of a computer, the computer is caused to execute the control method according to any one of claims 1 to 9.

Images