Height adjustment rate control method and system for closed air suspension system

Abstract

The invention discloses a method and system for controlling the height adjustment rate of a closed air suspension system, and the method comprises the following steps: firstly, the system receives the target height of a vehicle and the actual height obtained by a sensor, and calculates the height difference and the change rate thereof; then, the height difference and the change rate are fuzzified, and parameters Kp, Ki and Kd of a PID controller are generated based on a preset fuzzy rule; then, accurate PID control parameters are obtained through defuzzification, and a PID controller is designed and used for height adjustment of the air suspension system; the rotating speed of the compressor is adjusted according to the Kp value output by the PID controller, and the gas flow rate is controlled, so that the height adjusting rate is adjusted, and stable change of the suspension height is ensured. The control strategy can be dynamically optimized according to different vehicle working conditions and driving states, higher adjusting precision and response speed are provided, and driving comfort and stability are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy vehicle suspension, and relates to a method and system for controlling the height adjustment rate of a closed air suspension system. Background Technique

[0002] With the rapid development of new energy vehicle technology, especially the popularization of electric vehicles, the air suspension system has gradually become a standard suspension system for new energy vehicles, especially high-end electric cars and commercial vehicles, because it can dynamically adjust the vehicle height under different working conditions, improving the comfort and stability of the vehicle.

[0003] Different from traditional internal combustion engine vehicles, the drive system of new energy vehicles is mainly based on electric motors, with lower engine noise, zero emissions and higher efficiency. At the same time, the characteristics of the power system, control system and battery pack of electric vehicles also pose new requirements on the vehicle suspension system. For example, since electric vehicles generally use heavier battery packs, resulting in a large change in vehicle load, this poses higher requirements for the height adjustment rate of the air suspension system. In addition, electric vehicles usually have different driving characteristics and working conditions from traditional vehicles (such as lower vehicle speeds, larger braking energy recovery, etc.). Therefore, when performing height adjustment, the special working conditions of new energy vehicles must be considered to ensure the stability and comfort of the vehicle during the adjustment process.

[0004] In the existing air suspension system, the inflation and deflation of the air spring are realized by opening and closing the solenoid valve. However, the solenoid valve only has two actions of opening and closing, and cannot achieve the effect of controlling the gas pipeline flow rate. Therefore, it cannot control the height adjustment rate of the closed air suspension system (Dou Hui, Chen Long, Wang Shaohua, etc. Research on the vehicle height adjustment control of an electronically controlled closed air suspension [J]. Machinery Design & Manufacture, 2014, (09): 171-174.). However, during the actual vehicle driving process, when the target body height is too different from the actual body height, we hope that the height adjustment process of the vehicle body can be completed quickly so as to continue driving stably. When the target body height is relatively close to the actual body height, we hope that the height adjustment process of the vehicle body can be completed slowly, so as to reduce the overshoot and accurately reach the target height. This process is difficult to achieve in the existing air suspension height adjustment technology.

[0005] He Erbao et al. designed a fuzzy PID controller for vehicle body height adjustment and conducted simulations using Matlab / Simulink software. The simulation results showed that this method could solve the problems of oscillation and deviation from the set target height during the vehicle body height adjustment of an electronically controlled air suspension vehicle (He Erbao, Du Qungui, Feng Yuanyuan. Fuzzy PID Control for Vehicle Body Height Adjustment of Electronically Controlled Air Suspension [J]. Machine Tool & Hydraulics, 2012, 40(5): 86-88.). However, this technology has two deficiencies: First, this technology only uses the software simulation results as the conclusion, making it difficult to apply the designed fuzzy PID controller to a real vehicle and unable to solve the above problems existing during the real vehicle driving process. Second, the fuzzy PID controller designed by this technology cannot control the adjustment rate of the vehicle body height of an electronically controlled air suspension vehicle and is difficult to meet the requirements of the vehicle for changes in the height adjustment rate under different driving conditions. Summary of the Invention

[0006] The object of the present invention is to provide a method and system for controlling the height adjustment rate of a closed air suspension system, especially a method and system for controlling the rotational speed of a compressor of a closed air supply system through fuzzy PID control. First, by taking the vehicle body height difference and the change rate of the height difference as inputs and the PID control gain as the output, a fuzzy PID controller is designed to precisely control the height adjustment of the closed air suspension system. Then, by taking the height difference and the proportional gain Kp in the PID controller as inputs and the rotational speed of the compressor as the output, the rotational speed of the compressor is controlled to adjust the flow rate of the gas pipeline, thereby controlling the adjustment rate of the air suspension height, so as to implement a control method for adjusting the air suspension height rate. This method uses a fuzzy PID controller to intelligently adjust the PID control parameters based on the height error and the change rate of the height error, thereby precisely controlling the height adjustment rate of the air suspension system and enhancing the stability and comfort of the system. Ensure the stability and comfort of the vehicle under various working conditions.

[0007] The present invention is achieved by at least one of the following technical solutions.

[0008] A method for controlling the height adjustment rate of a closed air suspension system includes the following steps:

[0009] 1) The user or the vehicle sets the target vehicle body height gear as the target height according to the driving state, and collects the current height of the vehicle obtained by the height sensor in real time as the input signal of the system;

[0010] 2) Calculate the difference between the target vehicle body height and the actual height obtained by the sensor to obtain the height difference, and perform a time derivative operation on the height difference to obtain the change rate of the height difference;

[0011] 3) Divide both numerical ranges of the height difference and the change rate of the height difference into seven parts on average, from small to large: large negative, medium negative, small negative, zero, small positive, medium positive, large positive;

[0012] 4) According to the fuzzified height difference and the change rate of the height difference, generate the fuzzy value of the output quantity of the PID controller parameters through fuzzy rule mapping;

[0013] 5) Defuzzify the fuzzy output value: Integrate the obtained fuzzy value of the output quantity of the PID controller parameters into a specific value according to the range ratio of the fuzzy set where it is located. This process is called defuzzification, so as to obtain the PID controller parameters;

[0014] 6) According to the PID controller parameters obtained in step 5), with the height difference and the obtained PID controller parameters as inputs and the PID control gain as the output, design a PID controller and apply the PID controller to the height adjustment of the closed air suspension system;

[0015] 7) According to the differential gain Kp output by the PID controller obtained in step 6), adjust the rotational speed of the compressor of the closed air supply system to control the size of the high-pressure source pressure, so as to control the pressure difference in the gas pipeline to adjust the gas flow rate and realize the rate control of height adjustment.

[0016] Further, the vehicle body height described in step 2) refers to the distance from the highest point of the tire edge to the highest point of the wheel arch.

[0017] Further, in step 3), the two numerical ranges of the height difference and the change rate of the height difference are composed of a coefficient multiplied by the unit numerical range.

[0018] Further, in step 4), the fuzzy rules are as follows:

[0019] When the absolute value of the height difference is greater than 50% of the absolute value of the maximum height difference and the average value of the change rate is greater than the average change rate, increase the proportional gain Kp to quickly respond to height changes;

[0020] When the absolute value of the height difference is less than 50% of the absolute value of the maximum height difference and the average value of the change rate is less than the average change rate, increase the integral gain Ki to eliminate long-term small errors;

[0021] When the absolute value of the change in the height difference is greater than 50% of the absolute value of the maximum height difference, increase the differential gain Kd to slow down sudden height changes.

[0022] Further, in step 5), the defuzzification adopts the weighted average method and the center average method to convert the fuzzy output value into PID control parameters.

[0023] Further, the PID control parameters include a proportional gain Kp, an integral gain Ki, and a derivative gain Kd, and the proportional gain Kp, the integral gain Ki, and the derivative gain Kd are all composed of initial parameters and correction coefficients.

[0024] Further, in step 6), the PID controller outputs a control signal by using the height difference and the rate of change of the height difference, as well as the proportional gain Kp, the integral gain Ki, and the derivative gain Kd parameters of the PID controller, so as to adjust the pressure in the air spring airbag and realize the height adjustment of the closed air suspension system.

[0025] Further, in step 7), the control of the compressor speed of the closed air supply system is accurately adjusted based on the real-time feedback of the vehicle height information and in combination with the Kp value output by the PID controller. When the Kp value is greater than 25% of the maximum range, it is set as the high-speed gear, and when the Kp value is less than 25% of the maximum range, it is set as the low-speed gear to ensure the smooth change of the air suspension height.

[0026] A system for implementing the method for controlling the height adjustment rate of a closed air suspension system includes a closed air suspension control system model applicable to new energy vehicles. The closed air suspension control system model includes a fuzzy control part, a PID controller design part, a compressor speed regulation and control part, and a closed-loop feedback part;

[0027] Among them, the fuzzy control part includes the input, fuzzification of the height difference and the rate of change of the height difference, fuzzy inference through membership functions and fuzzy rules, defuzzification, and three outputs of the proportional gain Kp, the integral gain Ki, and the derivative gain Kd. The fuzzy control part converts the height difference and the rate of change of the height difference into three outputs of Kp, Ki, and Kd of the PID controller, so that the parameters of the PID control can change with the system in real time;

[0028] The PID controller design part includes the input of the height difference and the obtained PID controller parameters, the integration of the PID controller parameters, and the output of the PID control gain. The PID controller design part integrates the three parameters of Kp, Ki, and Kd obtained by fuzzy control and outputs the PID control gain, reduces the overshoot in the control process, reduces the time required for the system to reach stability, and makes the actual height closer to the target height when the system is stable, so as to make the control more accurate;

[0029] The compressor speed regulation and control part includes the input of the Kp value and the output of the compressor speed, enabling the fuzzy PID controller to control the gas pipeline flow rate and thus control the height adjustment rate;

[0030] The closed-loop feedback is composed of the feedback of the body height change detected by the body height sensor to the target height, which can enable the actual body height of the system to control the height difference in turn, and adjust the control strategy in real time according to the feedback information. Through feedback regulation, it ensures that the vehicle's target height can be maintained under various working conditions and provides a smooth adjustment process.

[0031] A computer device of the present invention includes: a memory, a processor, and a computer program stored on the memory. When the computer program is executed on the processor, the height adjustment rate control method of a closed-air suspension system is realized.

[0032] Compared with the existing technology, the beneficial effects of the present invention are as follows:

[0033] 1) The fuzzy PID control method provided by the present invention can adjust the height of the air suspension system more accurately. It has both the advantage that the fuzzy control parameters can be changed in real time with the system and the advantage that the PID control can reduce the overshoot in the control process, reduce the time required for the system to reach stability, and reduce the error between the actual height and the target height when the system is stable, thereby making the control more precise.

[0034] 2) The fuzzy PID control method provided by the present invention can realize the control of the height adjustment rate, and can make the height adjustment process have different performances under different working conditions. This control method can make the vehicle run more stably and the height adjustment result more accurate.

[0035] 3) Using a fuzzy PID controller can effectively eliminate the problem of unstable adjustment caused by too large or too small solenoid valve opening in the traditional control method, and improve the response speed and accuracy of the system.

[0036] 4) Optimize driving comfort: By finely adjusting the speed of the compressor, the vibration and impact in the traditional solenoid valve control method are avoided, and the comfort during vehicle driving is improved. Description of the Drawings

[0037] Figure 1 It is the schematic diagram of the fuzzy PID controller controlling the compressor speed in the embodiment.

[0038] Figure 2 It is the change diagram of the height adjustment rate at different compressor speeds.

[0039] Figure 3 It is the air suspension height adjustment curve in the embodiment. Detailed Embodiment

[0040] The following further describes the present invention in detail with reference to the drawings and embodiments.

[0041] This embodiment is applicable to the air charging and discharging model of a closed air suspension system for new energy vehicles. This model not only includes an air spring model such as the gas mass, gas temperature, pressure, and spring stiffness of the air spring, but also includes a solenoid valve flow model such as the solenoid valve mass flow rate, solenoid valve flow area, solenoid valve inlet and outlet pressures, and temperature. Finally, this model is combined with a 1 / 4 vehicle two-degree-of-freedom model to obtain the air charging and discharging model of the closed air suspension system.

[0042] As Figure 1 shown, a method for controlling the height adjustment rate of a closed air suspension system in this embodiment uses a fuzzy PID controller to dynamically adjust the PID parameters according to the difference between the target height and the actual height and its rate of change in real-time feedback, thereby controlling the compressor speed, adjusting the pressure in the airbag, and smoothly adjusting the height of the air suspension, including the following steps:

[0043] 1) First, the user or the vehicle sets the target body height gear as the target height according to the driving state, and collects the current height of the vehicle obtained by the height sensor in real-time as the input signal of the system.

[0044] 2) Calculate the difference between the target body height and the actual height obtained by the sensor to obtain the height difference, and perform a time derivative operation on the height difference to obtain the rate of change of the height difference.

[0045] The body height mentioned refers to the distance from the highest point of the tire edge to the highest point of the wheel arch. The measurement method is: measure the distance from the center of the wheel hub to the normal line of the highest point of the wheel arch, and then subtract the tire radius to obtain the body height.

[0046] 3) Divide both numerical ranges of the height difference and the rate of change of the height difference into 7 parts on average, from small to large: negative large (NB), negative medium (NM), negative small (NS), zero (ZO), positive small (PS), positive medium (PM), positive large (PB). This step fuzzifies the input quantities and obtains the fuzzy sets of the input quantities. At the same time, the fuzzy set range of the output quantity is also divided into the above 7 parts.

[0047] In step 3), both numerical ranges of the height difference and the rate of change of the height difference are composed of a coefficient multiplied by the unit numerical range. For example, the height difference E = ke * E0. As an embodiment, the value range of E0 is [-1, 1]. This scheme is used to adjust the value range of the height difference by setting the size of ke. This numerical range composition design also includes the rate of change of the height difference and the proportional gain Kp, integral gain Ki, and derivative gain Kd in step 4).

[0048] The fuzzy set described in step 3) and the above-mentioned unit value range are characterized in that the unit value ranges of the height difference and the change rate of the height difference in the input quantity and the unit value ranges of the proportional gain Kp, integral gain Ki, and derivative gain Kd in the output quantity are all evenly divided into 7 parts, and may also include 6 parts, 5 parts, etc. The division settings of the fuzzy set include 7 parts: negative large (NB), negative medium (NM), negative small (NS), zero (ZO), positive small (PS), positive medium (PM), and positive large (PB); it also includes 6 parts: negative large (NB), negative medium (NM), negative small (NS), positive small (PS), positive medium (PM), and positive large (PB); and may also include 5 parts: negative large (NB), negative small (NS), zero (ZO), positive small (PS), and positive large (PB), etc. Thus, the fuzzified input values are obtained.

[0049] 4) According to the fuzzified height difference and the change rate of the height difference, the fuzzy values of the three output quantities, namely the proportional gain Kp, integral gain Ki, and derivative gain Kd, are generated by mapping through fuzzy rules (the fuzzy rules are generally obtained by summarizing simulation and real vehicle tests).

[0050] The fuzzy rules are as follows:

[0051] When the absolute value of the height difference is greater than 50% of the absolute value of the maximum height difference and the average value of the change rate is greater than the average change rate, increase the proportional gain Kp to quickly respond to height changes.

[0052] When the absolute value of the height difference is less than 50% of the absolute value of the maximum height difference and the average value of the change rate is less than the average change rate, increase the integral gain Ki to eliminate long-term small errors.

[0053] When the absolute value of the change in the height difference is greater than 50% of the absolute value of the maximum height difference, increase the derivative gain Kd to slow down sudden height changes.

[0054] 5) Defuzzify the fuzzy output values: Integrate the fuzzy values of the three output quantities, namely the proportional gain Kp, integral gain Ki, and derivative gain Kd, into specific values according to the range ratio of the fuzzy sets where they are located. This process is called defuzzification, thereby obtaining the PID controller parameters.

[0055] The defuzzification step adopts the weighted average method and the center average method to convert the fuzzy output value into PID control parameters. The PID control parameters include the proportional gain Kp, the integral gain Ki, and the derivative gain Kd, all of which are composed of initial parameters and correction coefficients. For example, the proportional gain Kp = kp0 + ωp * kpa. Where kp0 is the initial parameter, ωp is the unit value range of Kp (see claim 3), and kpa is the correction coefficient, and the data structures of Ki and Kd are also included. Both the initial parameters and the correction coefficients can be modified during the simulation and real vehicle test processes to facilitate the precise control of the body height adjustment by the PID controller.

[0056] 6) Based on the PID controller parameters obtained in step 5), with the height difference and the obtained PID controller parameters as inputs and the PID control gain as the output, design a PID controller and apply the PID controller to the height adjustment of the closed air suspension system.

[0057] The PID controller outputs a control signal by utilizing the height difference, the rate of change of the height difference, and the parameters of the proportional gain Kp, the integral gain Ki, and the derivative gain Kd of the PID controller to adjust the pressure in the air spring airbag, thereby realizing the height adjustment of the closed air suspension system.

[0058] 7) According to the derivative gain Kp output by the PID controller obtained in step 6), adjust the rotational speed of the compressor of the closed air supply system to control the pressure of the high-pressure source, thereby controlling the pressure difference in the gas pipeline to adjust the gas flow rate and realizing the rate control of height adjustment.

[0059] In step 7), the control of the compressor rotational speed is precisely adjusted based on the real-time feedback of the vehicle height information in combination with the Kp value output by the PID controller. As an embodiment, when the Kp value is greater than 25% of the maximum range, it is set as the high rotational speed gear, and when the Kp value is less than 25% of the maximum range, it is set as the low rotational speed gear to ensure the smooth change of the air suspension height.

[0060] A system for implementing the height adjustment rate control method of the described closed-loop air suspension system includes a closed-loop air suspension control system model applicable to new energy vehicles. The closed-loop air suspension control system model includes a fuzzy control part, a PID controller design part, a compressor speed regulation and control part, and a closed-loop feedback part. Among them, the fuzzy control part consists of 5 parts: the input of the height difference and the change rate of the height difference, fuzzification, fuzzy reasoning through membership functions and fuzzy rules, defuzzification, and three outputs of the proportional gain Kp, integral gain Ki, and derivative gain Kd. This part transforms the height difference and the change rate of the height difference into the three outputs of Kp, Ki, and Kd of the PID controller, enabling the parameters of the PID control to change in real time with the system: The PID controller design part consists of 3 parts: the input of the height difference and the obtained PID controller parameters, the integration of the PID controller parameters, and the output of the PID control gain. This part integrates the three parameters of Kp, Ki, and Kd obtained by fuzzy control and outputs the PID control gain, reducing the overshoot in the control process and the time required for the system to reach stability, making the actual height closer to the target height when the system is stable, thus making the control more precise: The compressor speed regulation and control part consists of two parts: the input of the Kp value and the output of the compressor speed, enabling the fuzzy PID controller to control the gas pipeline flow rate and thus control the height adjustment rate: The closed-loop feedback is composed of the feedback of the body height change detected by the body height sensor to the target height, which can enable the actual body height of the system to control the height difference in turn and adjust the control strategy in real time according to the feedback information. Through feedback regulation, it is ensured that the vehicle's target height can be maintained under various working conditions and a smooth adjustment process is provided, such as Figure 1 .

[0061] Use the CANape software to adjust the compressor speed to five speed positions: 2000 r / min, 2500 r / min, 3000 r / min, 3500 r / min, and 4000 r / min. At different speed positions, set the execution height change to decrease from 0 to -40 mm and then increase to 40 mm, and observe the change in the height adjustment rate at different speeds. The test results are as Figure 2 shown. It can be seen that when the speed difference is 500 r / min, the height adjustment rate difference is relatively small.

[0062] Therefore, select the three speed positions of 2000 r / min, 3000 r / min, and 4000 r / min as the speed output values for system control, and control the speed size by taking values during the height adjustment process. Compare the height adjustment effect after controlling the speed with the threshold of 2 and the fuzzy PID control effect, as Figure 3As shown, it can be seen that although the fuzzy PID control does not significantly improve the height adjustment rate after controlling the compressor speed, the accuracy of height adjustment is significantly improved. This is because after adjusting the compressor speed, the height difference is small when the actual height of the vehicle body approaches the target height during the height adjustment process. The compressor speed is 2000 r / min, and the gas flow rate in the pipeline is slow, indirectly reducing the overshoot of height adjustment. Therefore, in engineering, the fuzzy PID controller that controls the compressor speed can effectively improve the accuracy of height adjustment.

[0063] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art can well understand and utilize the present invention.

Claims

1. A method for controlling the height adjustment rate of a closed air suspension system, characterized in that, It includes the following steps: 1) The user or the vehicle sets the target body height gear as the target height according to the driving state, and collects the current height of the vehicle obtained by the height sensor in real time as the input signal of the system; 2) Calculate the difference between the target body height and the actual height obtained by the sensor to get the height difference, and perform a time derivative operation on the height difference to obtain the change rate of the height difference; 3) Divide both numerical ranges of the height difference and the change rate of the height difference into seven parts from small to large, which are: large negative, medium negative, small negative, zero, small positive, medium positive, large positive; 4) According to the fuzzified height difference and the change rate of the height difference, generate the fuzzy value of the output quantity of the PID controller parameters through fuzzy rule mapping; 5) Defuzzify the fuzzy output value: Integrate the fuzzy value of the output quantity of the PID controller parameters obtained according to the range ratio of the fuzzy set where it is located into a specific value. This process is called defuzzification, so as to obtain the PID controller parameters; 6) According to the PID controller parameters obtained in step 5), with the height difference and the obtained PID controller parameters as the input and the PID control gain as the output, design a PID controller and use the PID controller for the height adjustment of the closed air suspension system; 7) According to the differential gain Kp output by the PID controller obtained in step 6), adjust the rotational speed of the compressor of the closed air supply system to control the pressure of the high-pressure source, so as to control the pressure difference in the air pipeline to adjust the gas flow rate and achieve the rate control of height adjustment.

2. The height adjustment rate control method of a closed air suspension system according to claim 1, characterized in that The body height described in step 2) refers to the distance from the highest point of the tire edge to the highest point of the wheel arch.

3. A method for controlling the height adjustment rate of a closed air suspension system according to claim 1, characterized in that, In step 3), both numerical ranges of the height difference and the change rate of the height difference are composed of a coefficient multiplied by the unit numerical range.

4. A method for controlling the height adjustment rate of a closed air suspension system according to claim 1, characterized in that, In step 4), the fuzzy rules are as follows: When the absolute value of the height difference is greater than 50% of the absolute value of the maximum height difference and the average value of the change rate is greater than the average change rate, increase the proportional gain Kp to quickly respond to height changes; When the absolute value of the height difference is less than 50% of the absolute value of the maximum height difference and the average value of the change rate is less than the average change rate, increase the integral gain Ki to eliminate long-term small errors; When the absolute value of the change in the height difference is greater than 50% of the absolute value of the maximum height difference, increase the differential gain Kd to slow down sudden height changes.

5. A method for controlling the height adjustment rate of a closed air suspension system according to claim 1, characterized in that, In step 5), the defuzzification adopts the weighted average method and the center average method to convert the fuzzy output value into PID control parameters.

6. A method for controlling the height adjustment rate of a closed air suspension system according to claim 6, characterized in that, The PID control parameters include the proportional gain Kp, the integral gain Ki, and the differential gain Kd. The proportional gain Kp, the integral gain Ki, and the differential gain Kd are all composed of initial parameters and correction coefficients.

7. A method for controlling the height adjustment rate of a closed air suspension system according to claim 1, characterized in that, In step 6), the PID controller outputs a control signal by using the height difference, the change rate of the height difference, and the parameters of the proportional gain Kp, the integral gain Ki, and the differential gain Kd of the PID controller to adjust the pressure in the air spring airbag and achieve the height adjustment of the closed air suspension system.

8. A method for controlling the height adjustment rate of a closed air suspension system according to claim 1, characterized in that In step 7), the compressor speed control of the closed air supply system is precisely adjusted based on the real-time feedback of vehicle height information, combined with the Kp value output by the PID controller. The Kp value greater than 25% of the maximum range is set as the high-speed gear, and the Kp value less than 25% of the maximum range is set as the low-speed gear to ensure the smooth change of the air suspension height.

9. A system for implementing the method for controlling the height adjustment rate of a closed air suspension system according to claim 1, characterized in that, It includes a closed air suspension control system model applicable to new energy vehicles. The closed air suspension control system model includes a fuzzy control part, a PID controller design part, a compressor speed regulation and control part, and a closed-loop feedback part; Among them, the fuzzy control part includes the input of height difference and the change rate of height difference, fuzzyfication, fuzzy inference through membership functions and fuzzy rules, defuzzyfication, and three outputs of proportional gain Kp, integral gain Ki, and derivative gain Kd. The fuzzy control part transforms the height difference and the change rate of height difference into three outputs of Kp, Ki, and Kd of the PID controller, enabling the parameters of the PID control to change in real time with the system; The PID controller design part includes the input of height difference and the obtained PID controller parameters, the integration of PID controller parameters, and the output of PID control gain. The PID controller design part integrates the three parameters of Kp, Ki, and Kd obtained by fuzzy control, outputs the PID control gain, reduces the overshoot in the control process, reduces the time required for the system to reach stability, and makes the actual height closer to the target height when the system is stable, thus making the control more precise; The compressor speed regulation and control part includes the input of the Kp value and the output of the compressor speed, enabling the fuzzy PID controller to control the gas pipeline flow rate, thereby controlling the height adjustment rate; The closed-loop feedback is composed of the feedback of the body height change detected by the body height sensor to the target height, which can enable the actual body height of the system to control the height difference in turn and adjust the control strategy in real time according to the feedback information. Through feedback regulation, it ensures that the system can maintain the target height of the vehicle under various working conditions and provides a smooth adjustment process.

10. A computer device, characterized in that, It includes: a memory, a processor, and a computer program stored on the memory. When the computer program is executed on the processor, it implements a method for controlling the height adjustment rate of a closed air suspension system as described in any one of claims 1 to 8.

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