A method, device and apparatus for adjusting suspension height based on air flow

Abstract

The present invention discloses a method, device and equipment for adjusting the height of a suspension based on air flow, the method comprising: obtaining a first mapping relationship between the air flow rate of each channel of a solenoid valve in a single cycle and the duty cycle under different pressure differences, and obtaining a second mapping relationship between the air flow rate required for the air spring to be charged and discharged under different internal air pressures and different initial heights and the unit height change; according to the second mapping relationship, constructing a third mapping relationship between the change in height of the air spring and the required air flow rate; based on the third mapping relationship, determining the single-cycle target air flow rate of the solenoid valve when the air spring is adjusted to the target height with a preset maximum adjustment time as a condition; determining the single-cycle duty cycle information of the solenoid valve according to the first mapping relationship and the single-cycle target air flow rate; and controlling the solenoid valve according to the duty cycle information to adjust the height of the air spring. The present invention achieves the purpose of accurately and smoothly adjusting the height of the air spring through the solenoid valve.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle suspension systems, and in particular to a method, device and equipment for adjusting the height of a suspension based on air flow. Background Art

[0002] In recent years, with the rapid development of vehicle electronic control technology, low-cost and high-performance automotive electronic control devices have become popular, and the air suspension system has also ushered in the era of electronic control. The ECAS (Electronic Control Air Suspension) system has gradually been recognized by the market for its superior stiffness control, comfort, driving smoothness and operational stability. It is currently widely used in the fields of high-end buses and tourist coaches, as well as commercial vehicles.

[0003] The electronically controlled air suspension system consists of an ECU, air springs, height sensors, air pressure sensors, solenoid valves, remote controls, and control switches. The ECU receives control command signals from the remote control and control switch, as well as sensor signals and other information, analyzes and processes the current known information, identifies the vehicle status, and then outputs a decision command. It controls the solenoid valve to charge and discharge the air spring through a PWM duty cycle signal, ultimately achieving vehicle height control.

[0004] At the same time, there are also many problems with the electronic air suspension system for commercial vehicles in the market, such as jitter during height control resulting in poor vehicle smoothness, frequent inflation and deflation of air springs, low height control accuracy, and left and right tilt of the vehicle body height. However, there is no solution to the above problems in the existing technology. Improving and optimizing the above control defects is the current technical difficulty of the electronic air suspension system. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned technical deficiencies and provide a suspension height adjustment method, device and equipment based on air flow, so as to solve the technical problems of low control accuracy and poor smoothness when the electronically controlled air suspension system adjusts the suspension height through air flow in the prior art.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for adjusting the height of a suspension based on air flow, comprising:

[0008] Obtain a first mapping relationship between the air flow rate of each channel of the solenoid valve for a single cycle of charging and discharging and the duty cycle under different pressure differences, and obtain a second mapping relationship between the air flow rate required for charging and discharging the air spring and the unit height change under different internal air pressures and different initial heights;

[0009] According to the second mapping relationship, construct a third mapping relationship between the change in air spring height and the required air flow rate;

[0010] Based on the third mapping relationship, and subject to a preset maximum adjustment time, determining a single-cycle target air flow rate of the solenoid valve when the air spring is adjusted to a target height;

[0011] According to the first mapping relationship and the single-cycle target air flow, the single-cycle duty cycle information of the solenoid valve is determined; and according to the duty cycle information, the solenoid valve is controlled to adjust the height of the air spring.

[0012] In some embodiments, the first mapping relationship is obtained through a solenoid valve air flow test, and the second mapping relationship is obtained through an air spring air flow test.

[0013] In some embodiments, constructing a third mapping relationship between the change in air spring height and the required air flow rate according to the second mapping relationship includes:

[0014] According to the second mapping relationship, determine an intermediate mapping relationship corresponding to the air flow rate required for the air spring to be inflated and deflated at different internal air pressures and current height values ​​and the unit height change;

[0015] According to the intermediate mapping relationship, a preset numerical integration method is used to determine the air flow required for adjusting the air spring from the current height value to the target height value under different air pressures, and a third mapping relationship between the air spring height change and the required air flow is constructed.

[0016] In some embodiments, determining the single-cycle target air flow rate of the solenoid valve when the air spring is adjusted to the target height based on the third mapping relationship and taking the preset maximum adjustment time as a condition includes:

[0017] Get the current height value, target height value, solenoid valve cycle time and preset maximum adjustment time of the air spring;

[0018] Determine the number of solenoid valve control cycles under the preset adjustment time according to the proportional relationship between the preset maximum adjustment time and the solenoid valve cycle time;

[0019] Taking the single-cycle target air flow rate as the target and the number of solenoid valve control cycles as the condition, a discrete PID control algorithm model is constructed;

[0020] The current height value of the air spring, the target height value and the number of control cycles of the solenoid valve are input into a discrete PID control algorithm model to obtain a single-cycle target air flow rate of the solenoid valve when the air spring is adjusted to the target height value.

[0021] In some embodiments, determining the single-cycle duty cycle information of the solenoid valve according to the first mapping relationship and the single-cycle target air flow rate includes:

[0022] Obtain the air source pressure value and the air spring internal pressure value;

[0023] Calculating the pressure difference between the air source pressure value and the air spring internal pressure value;

[0024] Based on the first mapping relationship, the single-cycle duty cycle information of the solenoid valve is determined according to the pressure difference and the single-cycle target air flow.

[0025] In some embodiments, after the solenoid valve is controlled according to the duty cycle information to adjust the height of the air spring, the method further includes:

[0026] Get the real-time height value of the air spring;

[0027] Determining the adjustment accuracy difference according to the difference relationship between the real-time height value of the air spring and the target height value;

[0028] If the adjustment accuracy difference is greater than a preset accuracy threshold, the real-time height value of the air spring, the target height value and the number of control cycles of the solenoid valve are used as inputs, and the discrete PID control algorithm model is adopted to determine the single-cycle corrected air flow of the solenoid valve when the air spring is adjusted to the target height value;

[0029] According to the first mapping relationship and the corrected air flow, the single-cycle corrected duty cycle information of the solenoid valve is determined; and according to the corrected duty cycle information, the solenoid valve is controlled to adjust the height of the air spring.

[0030] In some embodiments, constructing a third mapping relationship between the change in air spring height and the required air flow rate according to the second mapping relationship further includes:

[0031] determining a total air flow when the air spring is adjusted to a target height according to the corrected air flow and the single-cycle target air flow;

[0032] The third mapping relationship between the air spring height change and the required air flow rate is corrected according to the second mapping relationship and the total air flow rate.

[0033] In a second aspect, the present invention further provides a suspension height adjustment device based on air flow, comprising:

[0034] An acquisition module is used to acquire a first mapping relationship between the air flow rate of each channel of the solenoid valve for a single cycle of charging and discharging and the duty cycle under different pressure differences, and to acquire a second mapping relationship between the air flow rate required for charging and discharging the air spring and the unit height change under different internal air pressures and different initial heights;

[0035] A third mapping relationship determination module, used for constructing a third mapping relationship between the change in air spring height and the required air flow rate according to the second mapping relationship;

[0036] a target air flow determination module, configured to determine, based on the third mapping relationship and subject to a preset maximum adjustment time, a single-cycle target air flow of the solenoid valve when the air spring is adjusted to a target height;

[0037] The height adjustment module is used to determine the single-cycle duty cycle information of the solenoid valve according to the first mapping relationship and the single-cycle target air flow; and control the solenoid valve according to the duty cycle information to adjust the height of the air spring.

[0038] In a third aspect, the present invention further provides an electronic device, comprising: a processor and a memory;

[0039] The memory stores a computer-readable program executable by the processor;

[0040] When the processor executes the computer readable program, the steps in the suspension height adjustment method based on air flow as described above are implemented.

[0041] In a fourth aspect, the present invention further provides a computer-readable storage medium storing one or more programs, which can be executed by one or more processors to implement the steps in the suspension height adjustment method based on air flow as described above.

[0042] Compared with the prior art, the method, device and equipment for adjusting the height of a suspension based on air flow provided by the present invention first obtain a first mapping relationship between the air flow rate and the duty cycle of each channel of the solenoid valve in a single cycle under different pressure differences, and obtain a second mapping relationship between the air flow rate required for the air spring to be charged and discharged under different internal air pressures and different initial heights and the unit height change; then, a third mapping relationship between the height change of the air spring and the required air flow is constructed according to the second mapping relationship. By constructing the third mapping relationship to characterize the correlation between the air flow rate and the height change, the air flow rate information required for the height change of the air spring can be quantified, and the accuracy of the height adjustment of the air spring can be improved. Then, based on the third mapping relationship, the single-cycle target air flow rate of the solenoid valve when the air spring is adjusted to the target height is determined with a preset maximum adjustment time as a condition. On the one hand, the efficiency of the air spring adjustment is improved in combination with the maximum adjustment time. On the other hand, the number of cycles of the solenoid valve is accurately controlled with the maximum adjustment time as a limiting condition, and the air flow rate is allocated to a single cycle of the solenoid valve. The operation of the single cycle of the solenoid valve is used as a control unit, and the solenoid valve is controlled to adjust the height of the air spring according to the duty cycle information corresponding to the first mapping relationship, thereby improving the smoothness and accuracy of the air spring adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a flow chart of an embodiment of a suspension height adjustment method based on air flow provided by the present invention;

[0044] Figure 2 It is a schematic diagram of an embodiment of an air flow test bench in the suspension height adjustment method based on air flow provided by the present invention;

[0045] Figure 3 It is a schematic diagram of an embodiment of the dual-channel solenoid valve channel inflation in the suspension height adjustment method based on air flow provided by the present invention;

[0046] Figure 4 It is a schematic diagram of an embodiment of air release of a dual-channel solenoid valve channel in the suspension height adjustment method based on air flow provided by the present invention;

[0047] Figure 5 It is a mathematical model diagram of an embodiment of air spring inflation in the suspension height adjustment method based on air flow provided by the present invention;

[0048] Figure 6 It is a mathematical model diagram of an embodiment of air spring deflation in the suspension height adjustment method based on air flow provided by the present invention;

[0049] Figure 7 is a flow chart of an embodiment of step S102 in the method for adjusting the suspension height based on air flow provided by the present invention;

[0050] Figure 8 is a flow chart of an embodiment of step S103 in the method for adjusting the suspension height based on air flow provided by the present invention;

[0051] Fig. 9 It is a flow chart of an embodiment of air spring height correction in the suspension height adjustment method based on air flow provided by the present invention;

[0052] Fig.10 It is a flow chart of an embodiment of the third mapping relationship correction in the suspension height adjustment method based on air flow provided by the present invention;

[0053] Fig.11 is a schematic diagram of an embodiment of a suspension height adjustment device based on air flow provided by the present invention;

[0054] Fig.12 It is a schematic diagram of the operating environment of an electronic device provided by the present invention. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0056] Based on the flow characteristics of air springs and solenoid valves, the present invention accurately calculates the relationship between the change in air spring height and the required air flow through mathematical modeling and continuous self-learning, and designs a control algorithm to achieve precise control of the air spring height to meet the functional requirements of the ECAS system.

[0057] The embodiment of the present invention provides a method for adjusting the height of a suspension based on air flow. Figure 1 ,include:

[0058] S101, obtaining a first mapping relationship between the air flow rate of each channel of the solenoid valve in a single cycle and the duty cycle under different pressure differences, and obtaining a second mapping relationship between the air flow rate required for the air spring to be charged and discharged and the unit height change under different internal air pressures and different initial heights;

[0059] S102, constructing a third mapping relationship between the change in air spring height and the required air flow rate according to the second mapping relationship;

[0060] S103, based on the third mapping relationship and taking a preset maximum adjustment time as a condition, determining a single-cycle target air flow rate of the solenoid valve when the air spring is adjusted to a target height;

[0061] S104. Determine single-cycle duty cycle information of the solenoid valve according to the first mapping relationship and the single-cycle target air flow; and control the solenoid valve according to the duty cycle information to adjust the height of the air spring.

[0062] In this embodiment, first, a first mapping relationship between the air flow rate and the duty cycle of each channel of the solenoid valve in a single cycle under different pressure differences is obtained, and a second mapping relationship between the air flow rate required for the air spring to be charged and discharged under different internal air pressures and different initial heights and the unit height change is obtained; then, a third mapping relationship between the air spring height change and the required air flow rate is constructed according to the second mapping relationship. By constructing the third mapping relationship to characterize the correlation between the air flow rate and the height change, the air flow rate information required for the height change of the air spring can be quantified, and the accuracy of the air spring height adjustment can be improved. Then, based on the third mapping relationship, the single-cycle target air flow rate of the solenoid valve when the air spring is adjusted to the target height is determined with the preset maximum adjustment time as a condition. On the one hand, the efficiency of the air spring adjustment is improved in combination with the maximum adjustment time. On the other hand, the number of cycles of the solenoid valve is accurately controlled with the maximum adjustment time as a limiting condition, and the air flow rate is allocated to a single cycle of the solenoid valve. The operation of a single cycle of the solenoid valve is used as a control unit, and the solenoid valve is controlled to adjust the height of the air spring according to the duty cycle information corresponding to the first mapping relationship, thereby improving the smoothness and accuracy of the air spring adjustment.

[0063] It should be noted that the executor of the present invention may be a solenoid valve controller, or other devices that have similar functions to the solenoid valve or can achieve the same effect, such as a pneumatic controller or an electromagnet controller, etc. Further, in step S101, the model and number of channels of the solenoid valve are not limited, and the corresponding relationship between the air flow rate and the duty cycle of each channel of the solenoid valve in a single cycle under different pressure differences is characterized by the first mapping relationship, and the air flow rate is accurately distributed to each channel, so that the control of the solenoid valve is based on a single channel as a reference unit, which can improve the smoothness of the solenoid valve controlling the height of the air suspension, and improve the balance of the vehicle body, and avoid the problem of the vehicle body height tilting left and right.

[0064] Further, in step S101, the pressure difference refers to the difference between the internal pressure of the air spring and the air source pressure, wherein the internal pressure of the air spring refers to the pressure that the air spring is subjected to at the initial height, and further, the initial height refers to the current height of the air spring.

[0065] It is understandable that the magnitude of the internal pressure of the air spring determines the air flow rate required to change its height. Specifically, the greater the internal pressure of the air spring, the greater the air flow rate required to change its height.

[0066] Furthermore, in step S101, the second mapping relationship represents the relationship between the air flow rate and the unit height change under different internal air pressures and different initial heights. It can be understood that when the initial height of the air spring is different, the degree to which the air spring is compressed or stretched is different, which leads to different elastic forces of the air spring, thereby determining the air flow rate required to change its height. Therefore, by establishing the first mapping relationship table and the second mapping relationship table, the air flow rate required when the solenoid valve is used to control the height of the air spring can be intuitively and accurately represented, thereby further improving the efficiency and accuracy of the air spring adjustment.

[0067] In step S103, the preset maximum adjustment time refers to the maximum time limit of control implementation when adjusting the suspension height through the solenoid valve. It can be understood that the shorter the control implementation time, the higher the efficiency of the air spring height adjustment. However, if the control implementation time is too short, it may cause a sudden change in the air spring height, resulting in vehicle body shaking, affecting the comfort of the vehicle. Therefore, the preset maximum time limit is the optimal control implementation time set according to actual needs. By guiding the control implementation time of the solenoid valve through the preset maximum adjustment time, the purpose of efficient and smooth control of the air spring by the solenoid valve can be achieved.

[0068] Specifically, according to the characteristics of the electronically controlled air suspension system, when h0>h, the air spring is inflated, and the greater the current air pressure value, the longer the time required for height adjustment; when h0<h, the air spring is deflated, and the greater the current air pressure value, the shorter the time required for height adjustment. At the same time, the greater the height difference △h=|h0-h|, the longer the height control time. Therefore, in order to ensure the rapid response of the vehicle height, the air spring height control time is required to not exceed the maximum value T max .

[0069] According to the control response requirements of the electronically controlled air suspension system and the actual development and testing experience, the vehicle height control realization time requirement T is designed. max . T max The design value is related to the current air pressure value, the current height value and the current target height value of the air spring.

[0070] Furthermore, the single-cycle target air flow rate of the solenoid valve when the air spring is adjusted to the target height can be determined by a control algorithm based on the third mapping relationship and with the preset maximum adjustment time as a condition. It can be understood that there is no restriction on the type of control algorithm, as long as it can achieve the purpose of determining the single-cycle target air flow rate of the solenoid valve when the air spring is adjusted to the target height based on the third mapping relationship and with the preset maximum adjustment time as a condition. Specifically, the control algorithm can be a PID control algorithm, a Fuzzy-PID control algorithm, or a proportional-integral-differential control algorithm. In this embodiment, the control algorithm can be a PID control algorithm. Based on the third mapping relationship and with the preset maximum adjustment time as a condition, the single-cycle target air flow rate of the solenoid valve when the air spring is adjusted to the target height is determined by a PID control algorithm.

[0071] In step S104, the single-cycle duty cycle information of the solenoid valve is determined by the single-cycle target air flow, and the height of the air spring is adjusted based on the single cycle of the solenoid valve as a control reference unit, thereby improving the smoothness of the adjustment.

[0072] In some embodiments, the first mapping relationship is obtained through a solenoid valve air flow test, and the second mapping relationship is obtained through an air spring air flow test.

[0073] In this example, see Figure 2 , by building Figure 2 The air flow test bench shown in the figure performs solenoid valve air flow test and air spring air flow test. Specifically, it includes an ECAS controller, an altitude sensor, an air pressure sensor, a solenoid valve, an air spring (airbag), a remote controller and a switch. The air source pressure is adjusted by an air pump and an air source to obtain a first mapping relationship between the air flow rate of a single cycle of inflation and deflation and the duty cycle under different pressure differences, and a second mapping relationship between the air flow rate required for inflation and deflation of the air spring under different internal air pressures and different initial altitudes and the unit altitude change by adjusting the airbag pressure.

[0074] Specifically, the first mapping relationship can be represented by table MAP1, see Figure 3 and Figure 4 :

[0075] MAP1: I=φ1(p0-p, duty, f1);

[0076] I is the single-cycle output air flow rate of the solenoid valve under the current pressure difference and duty cycle, in L;

[0077] f1 is the single-cycle output air flow correction parameter under the current pressure difference and duty cycle of the solenoid valve, unit L;

[0078] p0 is the air source pressure value, unit is kpa;

[0079] p is the internal air pressure of the air spring, in kPa;

[0080] Duty is the duty cycle of the solenoid valve output, unit: %;

[0081] φ1 is a function that characterizes the relationship between air flow and duty cycle.

[0082] Furthermore, through the air spring air flow test, the gas volume data required for each 1mm change in the air spring height at different initial pressures and initial heights are obtained. Based on the above air spring test data, a table MAP2 is created to reflect the relationship between the amount of gas charged and discharged (gas volume under standard conditions) and the unit height change at different air pressures and different heights. Please refer to Figure 5 and Figure 6 .

[0083] MAP2: v = φ2 (h, p, f2)

[0084] v is the amount of gas required to control the unit height change of the air spring at the current height and air pressure, in L / mm;

[0085] f2 is the gas volume correction parameter required to control the unit height change of the air spring under the current height and air pressure, in L / mm;

[0086] h is the current height of the air spring, in mm;

[0087] p is the current air pressure of the air spring, in kPa;

[0088] φ2 is a function that characterizes the correlation between air flow and unit height change.

[0089] In some embodiments, the third mapping relationship between the change in air spring height and the required air flow is constructed based on the second mapping relationship. Figure 7 ,include:

[0090] S701, determining, based on the second mapping relationship, an intermediate mapping relationship between the air flow rate required for the air spring to be inflated and deflated and the unit height change under different internal air pressures and current height values;

[0091] S702. According to the intermediate mapping relationship, a preset numerical integration method is used to determine the air flow rate required for adjusting the air spring from the current height value to the target height value under different air pressures, and a third mapping relationship between the air spring height change and the required air flow rate is constructed.

[0092] In this embodiment, the second mapping relationship represents the characteristic information of different internal air pressures, different initial heights and required air flow rates under unit height changes. When any condition in the second mapping relationship is known, the association relationship corresponding to the other two conditions can be found. In this embodiment, when the initial height is known, the characteristic information of different internal air pressures and required air flow rates under unit height changes can be found, thereby obtaining the intermediate mapping relationship.

[0093] The intermediate mapping relationship represents the characteristic information of different internal air pressures and air flow rates under unit height changes. When the internal air pressure is known, the correlation between unit height change and air flow rate can be found, thereby inferring the air flow rate required when the air spring changes from the initial height to the target height, and thus inferring the air flow rate required when the air spring is adjusted from the initial height to the target height under different air pressures, and thus constructing a third mapping relationship. The air flow rate required for different height changes is represented by the third mapping relationship, which further quantifies the air flow rate of air spring height adjustment and improves the accuracy and efficiency of air spring adjustment.

[0094] Further, according to the second mapping relationship MAP2, the amount of gas required for adjusting the air spring from the current height value to the target height value under different air pressures is calculated by numerical integration, and a third mapping relationship reflecting the height change and the required gas amount is generated, which can be represented by Table MAP3:

[0095] MAP3: V=φ3(h0, h, p, f3)

[0096] V is the amount of gas required to control the air spring from height h to target h0 under the current air pressure, in L;

[0097] f3 is the gas volume correction parameter required to control the air spring from height h to target h0 under the current air pressure, in L;

[0098] h is the current height of the air spring, in mm;

[0099] h0 is the current target height value of the air spring, in mm;

[0100] p is the current air pressure of the air spring, in kPa;

[0101] φ3 is a function that characterizes the correlation between altitude change and required air flow rate.

[0102] Furthermore, in actual applications, the load value of the vehicle is constant after the cargo is loaded, the load transfer of a single axle during the vehicle height adjustment process is small, and the air spring pressure change is small. Therefore, it is assumed that the air spring pressure is constant during the vehicle height adjustment process. Therefore, the calculation formula for the gas volume V required to control the air spring from height h to target h0 under the current air pressure p is as follows:

[0103]

[0104] C3 is the integration constant.

[0105] In some embodiments, based on the third mapping relationship, the single-cycle target air flow rate of the solenoid valve when the air spring is adjusted to the target height is determined based on the preset maximum adjustment time. Figure 8 ,include:

[0106] S801, obtaining the current height value, target height value, solenoid valve cycle time and preset maximum adjustment time of the air spring;

[0107] S802, determining the number of solenoid valve control cycles under the preset adjustment time according to the proportional relationship between the preset maximum adjustment time and the solenoid valve cycle time;

[0108] S803, constructing a discrete PID control algorithm model with the single-cycle target air flow as the target and the number of solenoid valve control cycles as the condition;

[0109] S804. Input the current height value of the air spring, the target height value and the number of control cycles of the solenoid valve into a discrete PID control algorithm model to obtain a single-cycle target air flow rate of the solenoid valve when the air spring is adjusted to the target height value.

[0110] In this embodiment, the current vehicle air source pressure value p0, air spring internal pressure value p, height sensor value h, and control height target h0 value are input, the solenoid valve control cycle time is T0, and MAP3 is queried to determine the gas volume V0 required to achieve height adjustment. According to the difference between the target height and the current height, the vehicle height control realization time requirement T is determined. max .

[0111] T max =φ4(p,h0,h)

[0112] h is the current height of the air spring, in mm;

[0113] h0 is the current target height value of the air spring, in mm;

[0114] p is the current air pressure of the air spring, in kPa;

[0115] φ4 is a function that characterizes the maximum adjustment time and the air spring adjustment height.

[0116] Furthermore, according to the vehicle height control, the time requirement T max , determine the number of height control cycles N.

[0117] N≈T max / T0

[0118] According to the required gas volume target V0 and the number of control cycles N, a discrete PID control algorithm model based on flow is designed. Proportional coefficient K p , integral coefficient K i , differential coefficient K d Adjustment is carried out through actual vehicle tests.

[0119] u(k)=K p *e(k)+K i *+K d *[e(k)-e(k-1)]

[0120] Where u(k) is the output value of the controller; e(k) is the error between the controller input and the set value; K p is the proportionality coefficient; K i is the integral coefficient; K d is the differential coefficient; the above PID model is used to calculate the amount of gas required for inflation or deflation in N cycles to achieve the current control target, and MAP1 is queried to determine the duty cycle value required for each cycle. The duty cycle signal is output to the solenoid valve, and the current solenoid valve's inflation and deflation flow is controlled to achieve the current height control target.

[0121] In some embodiments, determining the single-cycle duty cycle information of the solenoid valve according to the first mapping relationship and the single-cycle target air flow rate includes:

[0122] Obtain the air source pressure value and the air spring internal pressure value;

[0123] Determining the pressure difference according to the difference between the air source pressure value and the air spring internal pressure value;

[0124] Based on the first mapping relationship, the single-cycle duty cycle information of the solenoid valve is determined according to the pressure difference and the single-cycle target air flow.

[0125] In this embodiment, the first mapping relationship represents the correlation between the duty cycle of each channel of the solenoid valve, the pressure difference and the air flow. When the pressure difference and air flow are known, the corresponding duty cycle can be found, so that the solenoid valve can work according to the determined duty cycle to achieve precise adjustment of the air spring height.

[0126] In some embodiments, after the solenoid valve is controlled according to the duty cycle information to adjust the height of the air spring, refer to Fig. 9 , also includes:

[0127] S901, obtaining the real-time height value of the air spring;

[0128] S902, determining an adjustment accuracy difference according to a difference relationship between the real-time height value of the air spring and the target height value;

[0129] S903, if the adjustment accuracy difference is greater than a preset accuracy threshold, taking the real-time height value of the air spring, the target height value and the number of control cycles of the solenoid valve as inputs, a well-trained discrete PID algorithm is used to determine a single-cycle corrected air flow rate of the solenoid valve when the air spring is adjusted to the target height value;

[0130] S904. Determine single-cycle corrected duty cycle information of the solenoid valve according to the first mapping relationship and the corrected air flow; and control the solenoid valve according to the corrected duty cycle information to adjust the height of the air spring.

[0131] In this embodiment, when the controller receives the target height, it queries MAP3 to determine the amount of gas required to achieve height adjustment based on the current vehicle's air source pressure value, the air spring internal pressure value, the initial height value, and the control height target value. The duty cycle signal output by the current vehicle height control algorithm is input into the solenoid valve to control the current solenoid valve's charging and discharging flow rate. After a height adjustment is completed, it is determined whether the current height value matches the target height value and whether it meets the control accuracy requirements. If the control accuracy requirements are met, the current height control is completed; if not, the output duty cycle is calculated again according to the vehicle height control algorithm to control the solenoid valve to charge and discharge until the control accuracy requirements are met.

[0132] It should be noted that there is no limit to the size of the preset accuracy threshold, which can be determined according to the actual needs of vehicle movement and the accuracy of the control system itself. It can be understood that the smaller the absolute value of the accuracy threshold, the greater the accuracy of the solenoid valve controlling the air spring height adjustment.

[0133] It is understandable that the corrected air flow is the air flow required for the new height of the air spring obtained after the previous height adjustment to the target height. The corrected duty cycle is the solenoid valve duty cycle corresponding to the air flow required for the new height of the air spring obtained after the previous height adjustment to the target height.

[0134] In some embodiments, the third mapping relationship between the change in air spring height and the required air flow is constructed based on the second mapping relationship. Fig.10 , also includes:

[0135] S1001, determining a total air flow when the air spring is adjusted to a target height according to the corrected air flow and the single-cycle target air flow;

[0136] S1002. Correct the third mapping relationship between the air spring height change and the required air flow rate according to the second mapping relationship and the total air flow rate.

[0137] In this embodiment, after each altitude flow control is completed, the table MAP3 is further corrected according to the current altitude adjusted this time, the actual controlled altitude, the calculated required gas volume and the actual required gas volume.

[0138]

[0139] V0 is the amount of gas required to control the air spring from height h to target h1 under the current air pressure, in L;

[0140] V1 is the actual amount of gas required to control the air spring from height h to target h1 under the current air pressure, in L;

[0141] f3 is the gas volume correction parameter required to control the air spring from height h to target h1 under the current air pressure, in L;

[0142] p is the current air pressure of the air spring, in kPa;

[0143] h is the current height of the air spring, in mm;

[0144] h1 is the actual control height value of the air spring, in mm;

[0145] It is a function that characterizes the correlation between the corrected air flow and altitude change.

[0146] It should be noted that by further correcting and updating Table MAP3 according to the current height of this adjustment, the actual control height, the calculated required gas volume and the actual required gas volume after each height flow control is completed, the error caused by the change in the height of the air spring controlled by air flow caused by the aging of the air spring or other uncontrollable usage factors can be eliminated, thereby further improving the accuracy of the air spring height adjustment.

[0147] In a specific embodiment, the vehicle electronically controlled air suspension system is composed of an ECAS controller, a height sensor, an air pressure sensor, a solenoid valve, an air spring (airbag), a remote control and a switch. The ECAS controller monitors the height sensor and air pressure sensor signals in real time, and after receiving the height control switch and remote control control command, it sends a PWM signal to control the solenoid valve to inflate / deflate the air spring. The system is required to set the time T max The vehicle height is controlled to the set height target value (H1) within a certain period of time, while ensuring the height control accuracy of ±8mm.

[0148] T max =φ4(p,h0,h)=a*(h0-h)

[0149] Taking into account the actual needs, the value of a is taken as 0.1, which requires a high control speed of 10mm / s.

[0150] It is known that the vehicle air source pressure is 12 bar and the solenoid valve control cycle is set to 300ms.

[0151] Input the current air spring pressure value of 300kpa, the current value of the height sensor of 1000mm, and the control height target value of 1020mm. According to the input query table MAP3, it can be known that V0 = 10L.

[0152] High control implementation time requirement T max =2s; number of cycles N≈7.

[0153] K p =0.02; K i =0.0001; K d =0.02.

[0154] The required inflation volumes for N cycles are 2.5, 2.5, 2, 1.7, 1.2, 0.3, and 0 respectively.

[0155] The duty cycles are 100, 100, 100, 100, 80, 60, 40 respectively.

[0156] The duty cycle signal is output to the solenoid valve for height control.

[0157] After the current height flow control is completed, determine whether the current height is within ±8mm of the target height.

[0158] If h0-h≤8, the current height control is completed; if h0-h>8, the output duty cycle is calculated again according to the vehicle height control algorithm to control the charging and deflation of the solenoid valve until the control accuracy requirements are met.

[0159] The current height is controlled at 1017mm, h0-h=3mm≤8mm, which meets the control accuracy requirements, and the height control is completed.

[0160] After the altitude flow control is completed, MAP3 is corrected according to the actual controlled gas volume and the actual controlled altitude value.

[0161] f3=φ5(p,h1,h,V0,V1)

[0162] Current air pressure p = 300 kpa, h = 1000 mm, h1 = 1017 mm, V0 = 9.7 L, V1 = 10.5 L

[0163] Therefore, the required gas value V for the calculation of MAP3 with a pressure of 300 kPa, an initial altitude of 1000 mm, and a target altitude of 1017 mm is corrected to V = V0 + b*(V1-V0). b is a weighting coefficient, which is 0.3.

[0164] The embodiments of the present invention have the following advantages:

[0165] 1. Precise control: The flow control method can achieve precise control of the height change of the air spring, and the required height change can be achieved by adjusting the flow rate of the inflated or released gas.

[0166] 2. Good smoothness: Due to the direct control of air flow, the flow control method can achieve a faster response speed and effectively avoid the oscillation of the air spring height.

[0167] 3. Good real-time performance: The control process of the flow control method can be monitored and adjusted in real time, and can respond to external changes and interference in a timely manner to maintain a stable high control effect.

[0168] 4. Low gas consumption: height control is achieved by directly controlling the flow rate, which can effectively avoid frequent filling and deflation of the air spring and reduce gas consumption.

[0169] Based on the above suspension height adjustment method based on air flow, the embodiment of the present invention also provides a suspension height adjustment device 1100 based on air flow, see Fig.11 The air flow-based suspension height adjustment device 1100 includes an acquisition module 1101 , a third mapping relationship determination module 1102 , a target air flow determination module 1103 and a height adjustment module 1104 .

[0170] An acquisition module 1101 is used to acquire a first mapping relationship between the air flow rate of each channel of the solenoid valve for a single cycle of charging and discharging and the duty cycle under different pressure differences, and to acquire a second mapping relationship between the air flow rate required for charging and discharging the air spring and the unit height change under different internal air pressures and different initial heights;

[0171] A third mapping relationship determination module 1102, configured to construct a third mapping relationship between the change in air spring height and the required air flow rate according to the second mapping relationship;

[0172] A target air flow determination module 1103 is used to determine a single-cycle target air flow of the solenoid valve when the air spring is adjusted to a target height based on the third mapping relationship and taking a preset maximum adjustment time as a condition;

[0173] The height adjustment module 1104 is used to determine the single-cycle duty cycle information of the solenoid valve according to the first mapping relationship and the single-cycle target air flow; and control the solenoid valve according to the duty cycle information to adjust the height of the air spring.

[0174] like Fig.12 As shown, based on the above suspension height adjustment method based on air flow, the present invention also provides an electronic device, which can be a computing device such as a mobile terminal, a desktop computer, a notebook, a palm computer, and a server. The electronic device includes a processor 1210, a memory 1220, and a display 1230. Fig.12 Only some components of the electronic device are shown, but it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.

[0175] In some embodiments, the memory 1220 may be an internal storage unit of the electronic device, such as a hard disk or memory of the electronic device. In other embodiments, the memory 1220 may also be an external storage device of the electronic device, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (SecureDigital, SD) card, a flash card (Flash Card), etc. equipped on the electronic device. Further, the memory 1220 may also include both an internal storage unit of the electronic device and an external storage device. The memory 1220 is used to store application software and various types of data installed in the electronic device, such as program codes for installing the electronic device. The memory 1220 may also be used to temporarily store data that has been output or is to be output. In one embodiment, the memory 1220 stores a suspension height adjustment program 1240 based on air flow, and the suspension height adjustment program 1240 based on air flow can be executed by the processor 1210, thereby realizing the suspension height adjustment method based on air flow in each embodiment of the present application.

[0176] In some embodiments, the processor 1210 may be a central processing unit (CPU), a microprocessor or other data processing chip, used to run program codes or process data stored in the memory 1220, such as executing a suspension height adjustment method based on air flow.

[0177] In some embodiments, the display 1230 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, an OLED (Organic Light-Emitting Diode) touch device, etc. The display 1230 is used to display information on the air flow-based suspension height adjustment device and to display a visual user interface. The components 1210-1230 of the electronic device communicate with each other via a system bus.

[0178] Of course, those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the program can be stored in a computer-readable storage medium, and the program can include the processes of the above-mentioned method embodiments when executed. The storage medium can be a memory, a disk, an optical disk, etc.

[0179] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for adjusting suspension height based on air flow, characterized in that: include: Obtain a first mapping relationship between the air flow rate of each channel of the solenoid valve for a single cycle of charging and discharging and the duty cycle under different pressure differences, and obtain a second mapping relationship between the air flow rate required for charging and discharging the air spring and the unit height change under different internal air pressures and different initial heights; According to the second mapping relationship, construct a third mapping relationship between the change in air spring height and the required air flow rate; Obtain the current height value, target height value, solenoid valve cycle time and preset maximum adjustment time of the air spring; determine the number of solenoid valve control cycles under the preset maximum adjustment time according to the proportional relationship between the preset maximum adjustment time and the solenoid valve cycle time; construct a discrete PID control algorithm model with the single-cycle target air flow as the target and the number of solenoid valve control cycles as the condition; input the current height value, target height value and the number of solenoid valve control cycles of the air spring into the discrete PID control algorithm model to obtain the single-cycle target air flow of the solenoid valve when the air spring is adjusted to the target height value; Determining single-cycle duty cycle information of the solenoid valve according to the first mapping relationship and the single-cycle target air flow rate, and controlling the solenoid valve according to the duty cycle information to adjust the height of the air spring; Acquire the real-time height value of the air spring; determine the adjustment accuracy difference according to the difference relationship between the real-time height value of the air spring and the target height value; if the adjustment accuracy difference is greater than a preset accuracy threshold, use the real-time height value of the air spring, the target height value and the number of control cycles of the solenoid valve as inputs, adopt the discrete PID control algorithm model, and determine the single-cycle corrected air flow of the solenoid valve when the air spring is adjusted to the target height value; determine the single-cycle corrected duty cycle information of the solenoid valve according to the first mapping relationship and the corrected air flow; and controlling the solenoid valve according to the modified duty cycle information to adjust the height of the air spring; determining a total air flow when the air spring is adjusted to a target height according to the corrected air flow and the single-cycle target air flow; The third mapping relationship between the air spring height change and the required air flow rate is corrected according to the second mapping relationship and the total air flow rate.

2. The method for adjusting the suspension height based on air flow according to claim 1, characterized in that: The first mapping relationship is obtained through a solenoid valve air flow test, and the second mapping relationship is obtained through an air spring air flow test.

3. The method for adjusting the suspension height based on air flow according to claim 1, characterized in that: The step of constructing a third mapping relationship between the change in air spring height and the required air flow rate according to the second mapping relationship includes: According to the second mapping relationship, determine an intermediate mapping relationship corresponding to the air flow rate required for the air spring to be inflated and deflated at different internal air pressures and current height values ​​and the unit height change; According to the intermediate mapping relationship, a preset numerical integration method is used to determine the air flow required for adjusting the air spring from the current height value to the target height value under different air pressures, and a third mapping relationship between the air spring height change and the required air flow is constructed.

4. The method for adjusting the suspension height based on air flow according to claim 1, characterized in that: Determining the single-cycle duty cycle information of the solenoid valve according to the first mapping relationship and the single-cycle target air flow rate includes: Obtain the air source pressure value and the air spring internal pressure value; Calculating the pressure difference between the air source pressure value and the air spring internal pressure value; Based on the first mapping relationship, the single-cycle duty cycle information of the solenoid valve is determined according to the pressure difference and the single-cycle target air flow.

5. A suspension height adjustment device based on air flow, characterized in that: include: An acquisition module is used to acquire a first mapping relationship between the air flow rate of each channel of the solenoid valve for a single cycle of charging and discharging and the duty cycle under different pressure differences, and to acquire a second mapping relationship between the air flow rate required for charging and discharging the air spring and the unit height change under different internal air pressures and different initial heights; A third mapping relationship determination module, used for constructing a third mapping relationship between the change in air spring height and the required air flow rate according to the second mapping relationship; A target air flow determination module is used to obtain the current height value of the air spring, the target height value, the solenoid valve cycle time and the preset maximum adjustment time; according to the proportional relationship between the preset maximum adjustment time and the solenoid valve cycle time, determine the number of solenoid valve control cycles under the preset maximum adjustment time; take the single-cycle target air flow as the target and the number of solenoid valve control cycles as the condition to construct a discrete PID control algorithm model; input the current height value of the air spring, the target height value and the number of solenoid valve control cycles into the discrete PID control algorithm model to obtain the single-cycle target air flow of the solenoid valve when the air spring is adjusted to the target height value; A height adjustment module, used to determine the single-cycle duty cycle information of the solenoid valve according to the first mapping relationship and the single-cycle target air flow, and control the solenoid valve according to the duty cycle information to adjust the height of the air spring; obtain the real-time height value of the air spring; determine the adjustment accuracy difference according to the difference relationship between the real-time height value of the air spring and the target height value; if the adjustment accuracy difference is greater than a preset accuracy threshold, use the real-time height value of the air spring, the target height value and the number of control cycles of the solenoid valve as inputs, and use the discrete PID control algorithm model to determine the single-cycle corrected air flow of the solenoid valve when the air spring is adjusted to the target height value; determine the single-cycle corrected duty cycle information of the solenoid valve according to the first mapping relationship and the corrected air flow; and controlling the solenoid valve according to the modified duty cycle information to adjust the height of the air spring; determining a total air flow when the air spring is adjusted to a target height according to the corrected air flow and the single-cycle target air flow; The third mapping relationship between the air spring height change and the required air flow rate is corrected according to the second mapping relationship and the total air flow rate.

6. An electronic device, characterized in that: include: Processor and memory; The memory stores a computer-readable program executable by the processor; When the processor executes the computer-readable program, the steps in the method for adjusting the suspension height based on air flow are implemented as described in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores one or more programs, and the one or more programs can be executed by one or more processors to implement the steps in the suspension height adjustment method based on air flow as described in any one of claims 1-4.

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