High-precision load control method and system for testing aviation tires

Abstract

The application relates to the field of aviation tire testing, in particular to a high-precision load control method and system for simulating take-off test on aviation tires, and is used for solving the problem of poor dynamic load control precision of large inertia and high frequency response. The application adopts a loading force and deformation displacement double-amount feedforward closed-loop control mode to realize load control. The core is to calculate aviation tire dynamic stiffness by using the real-time measured force and displacement values in the test, and the stiffness coefficient is used for real-time adjustment of the feedforward parameter, and the first candidate displacement amount is calculated by the target load and the stiffness coefficient. In addition, the application also uses a number set to calculate the second candidate displacement amount in the section where the target load changes at a high speed. Finally, the first candidate displacement amount or the second candidate displacement amount is selected according to the actual situation to execute the action. When facing a complex load curve, the application can effectively complete the high-precision control task of the load curve.

Description

Technical Field

[0001] This invention relates to the field of aircraft tire testing, specifically a high-precision load control method and system for aircraft tire testing. Background Technology

[0002] In simulated aircraft landing tests, it is necessary to apply loads to the aircraft tires according to test standards, that is, to control the hydraulic cylinders to apply corresponding loads to the aircraft tires according to the load curve.

[0003] However, in actual testing, because the test specimen is an aircraft tire, a flexible object, the dynamic stability and responsiveness requirements of force control are high. Traditional PID control cannot be used; model-based control is necessary to achieve the desired experimental results. When the load changes significantly, the force control method requires a large control opening for the servo valve. If the tire's stability is poor and a blowout occurs, the valve opening may not be able to reverse in time due to the limited opening, potentially damaging the equipment. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a high-precision load control method and system for aircraft tire testing, so as to solve the problem of equipment damage that is easily caused in aircraft tire load testing.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The present invention provides a high-precision load control method for aircraft tire testing, comprising the following steps:

[0007] Obtain the load curve, wherein the load curve includes the target load at multiple test time points;

[0008] The measured stiffness value of the aircraft tire subjected to load test at the previous test time point is used as the initial stiffness value of the aircraft tire at the current test time point. The initial stiffness value is then filtered and smoothed to obtain the stiffness value at the current time point. The load test of the aircraft tire is performed based on a preset hydraulic cylinder.

[0009] A reference set is constructed based on test execution data from multiple test time points prior to the current test time point. The reference set includes the executed target loads and the displacements corresponding to the executed target loads from multiple test time points prior to the current test time point.

[0010] When the target load at the current test time point is less than the preset load threshold, the first candidate displacement at the current test time point is calculated based on the stiffness value and the target load at the current test time point; when the target load at the current test time point is greater than or equal to the preset load threshold, the second candidate displacement at the current test time point is determined based on the reference set.

[0011] Based on the first candidate displacement or the second candidate displacement, the hydraulic cylinder device is controlled to apply a load to the aircraft tire at the current time point.

[0012] In one embodiment of this application, the initial stiffness value at the current test time point is determined based on the target load and displacement of the hydraulic cylinder device at the current test time point, the displacement at the current test time point is determined based on the target load at the current test time point and the stiffness value at the previous test time point, and the stiffness value at the first test time point is determined by a static stiffness value test.

[0013] The mathematical expression for the initial stiffness value is:

[0014]

[0015] In the formula, S i F' represents the initial stiffness value of the aircraft tire at the current test time. i-1 D' represents the measured load at the previous test time point. i-1 D represents the measured displacement of the hydraulic cylinder at the previous test time point. zero This refers to the displacement of the hydraulic cylinder at its zero-point position when it just makes contact with the aircraft tire.

[0016] In one embodiment of this application, the mathematical expression for the first candidate displacement at the current test time point is:

[0017]

[0018] In the formula, F i For the target load at the current test time point, C T C is the first adjustment parameter. f This is the second adjustment parameter. D represents the stiffness value of the aircraft tire at the current test time. zero This refers to the displacement of the hydraulic cylinder at its zero-point position when it just makes contact with the aircraft tire.

[0019] In one embodiment of this application, the initial stiffness value is filtered and smoothed, including:

[0020] The initial stiffness value at the current test time point is filtered based on a pre-built dynamic filtering range;

[0021] When the initial stiffness value at the current test time point falls within the dynamic screening range, the initial stiffness value at the current test time point is smoothed based on the stiffness values ​​at multiple time points prior to the current test time point to obtain the stiffness value at the current test time point.

[0022] In one embodiment of this application, the method for constructing the dynamic filtering range includes:

[0023] Construct an initial filtering range, wherein the lower limit of the initial filtering range is... The upper limit of the initial filtering range is

[0024] In the segment where the target load is greater than or equal to the preset load threshold, the process is executed cyclically within the target time period. until Among them, S Init is the initial stiffness value of the aircraft tire, and n is the number of cycles;

[0025] In the segment where the target load is less than the preset load threshold, the process is executed cyclically within the target time period. until

[0026] Based on the upper limit value and the lower limit of the change Build a dynamic filtering range.

[0027] In one embodiment of this application, smoothing the initial stiffness value at the current test time point based on stiffness values ​​at multiple time points prior to the current test time point includes:

[0028] The stiffness value at the current test time point and the measured stiffness values ​​at multiple time points before the current test time point are placed in a set. When the number of elements in the set is less than n', multiple elements representing the target stiffness value are added to the front of the set so that the number of elements in the set is greater than or equal to n', where n' is the length of the mean filtering.

[0029] Multiple mean filters and sliding filters of various lengths are applied to multiple elements in the set to obtain multiple filtering results. The mathematical expression for the mean filter is:

[0030]

[0031] In the formula, This is the result of mean filtering;

[0032] The mathematical expression for the slip filter is:

[0033]

[0034] In the formula, This is the result of the sliding filter, where x is the proportional value;

[0035] The progress of the preset filtering and smoothing process at the current test time point is determined, and based on the progress of the preset filtering and smoothing process at the current test time point and the type of hydraulic cylinder equipment, the mean filtering result and the slip filtering result are combined to obtain the stiffness value at the current test time point.

[0036] In one embodiment of this application, the filtering smoothing process is used to smoothly switch from one filtering method to another during an experiment. The filtering smoothing process includes:

[0037] In the segment where the target load is greater than or equal to the preset load threshold, the process is executed cyclically within the target time period. until in, S represents the progress of the preset filtering and smoothing process at the current test time point. Init％ S is the initial value for the progress. min％ The final progress value is ΔS%, where ΔS% is the progress change. n is the number of iterations;

[0038] In the segment where the target load is less than the preset load threshold, the process is executed cyclically within the target time period. until

[0039] In one embodiment of this application, the stiffness value at the current test time point The mathematical expression is:

[0040]

[0041] In the formula, The first candidate stiffness value, This is the result of mean filtering with a length of n'1. This is the result of mean filtering with a length of n'2. This is the second candidate stiffness value. The result of mean filtering with length n'3

[0042] In one embodiment of this application, a reference dataset is constructed based on test execution data from multiple test time points prior to the current test time point, including:

[0043] Obtain the executed target loads and displacements of the executed target loads at multiple test time points prior to the current test time point;

[0044] Construct an initial load set, and compare all executed target loads with the initial load set in sequence. If an executed target load is greater than any element in the initial load set, add the executed target load to the load set to obtain the load set.

[0045] A displacement set is constructed based on the displacement of each executed target load in the load set;

[0046] A reference set is constructed based on the load set and the displacement set.

[0047] In one embodiment of this application, determining the second candidate displacement at the current test time point based on the reference set includes:

[0048] If an executed load consistent with the target load at the current test time point exists in the reference set, the displacement corresponding to the executed load consistent with the target load at the current test time point shall be used as the second candidate displacement at the current test time point.

[0049] If no executed load in the reference set is consistent with the target load at the current test time point, two executed loads that satisfy the target conditions are retrieved from the reference set, and interpolation is performed based on the displacements of the two executed loads that satisfy the target conditions to obtain the second candidate displacement at the current test time point. The target conditions include: the executed load F' (n) Executed load F' (n+1) The target load F at the current time point i Closest, and F' (n) <F i <F' (n+1) .

[0050] In one embodiment of this application, the mathematical expression for the interpolation operation is:

[0051]

[0052] In the formula, D' is the second candidate displacement at the current test time point. (n+1) For the executed load F' (n+1) The corresponding displacement, D' (n) For the executed load F' (n) The corresponding displacement.

[0053] In one embodiment of this application, controlling the hydraulic cylinder device to apply a load to the aircraft tire at the current time point based on the first candidate displacement or the second candidate displacement includes:

[0054] When the target load at the current test time point is less than the preset load threshold, based on the first candidate displacement D i Construction displacement control quantity And based on displacement control quantity The hydraulic cylinder device is controlled to apply a load to the aircraft tire, wherein C -1 This is the third adjustment parameter;

[0055] When the target load at the current test time point is greater than or equal to a preset load threshold, and the target load at the current test time point is greater than or equal to the maximum executed load in the reference set, based on the first candidate displacement D... i Construction displacement control quantity And based on displacement control quantity The hydraulic cylinder device is controlled to apply a load to the aircraft tire, wherein C1 is the fourth adjustment parameter;

[0056] The target load at the current test time point is greater than or equal to a preset load threshold, the target load at the current test time point is less than the maximum executed load in the reference set, and the first candidate displacement D i With the second candidate displacement The difference At that time, based on the second candidate displacement Construction displacement control quantity And based on displacement control quantity The hydraulic cylinder device is controlled to apply a load to the aircraft tire, wherein C3 is the fifth adjustment parameter;

[0057] If the target load at the current test time is greater than or equal to a preset load threshold, and the target load at the current test time is less than the maximum executed load in the reference set, then the first candidate displacement D... i With the second candidate displacement The difference and At that time, the first candidate displacement D i As displacement control quantity And based on displacement control quantity The hydraulic cylinder device is used to apply load to the aircraft tire;

[0058] If the target load at the current test time is greater than or equal to a preset load threshold, and the target load at the current test time is less than the maximum executed load in the reference set, then the first candidate displacement D... i With the second candidate displacement The difference and At that time, based on the second candidate displacement Construction displacement control quantity And based on displacement control quantity The hydraulic cylinder device is controlled to apply a load to the aircraft tire, wherein C2 is the sixth adjustment parameter.

[0059] This application also provides a high-precision load control system for aircraft tire testing, including:

[0060] An acquisition module is used to acquire load curves, wherein the load curves include target loads at multiple test time points;

[0061] The first processing module is used to take the measured stiffness value of the aircraft tire at the previous test time point as the initial stiffness value of the aircraft tire at the current test time point, and to filter and smooth the initial stiffness value to obtain the stiffness value at the current time point. The load test of the aircraft tire is performed based on a preset hydraulic cylinder.

[0062] The second processing module is used to construct a reference set based on the test execution data of multiple test time points before the current test time point, wherein the reference set includes the executed target loads and the displacements corresponding to the executed target loads at multiple test time points before the current test time point;

[0063] The calculation module is used to calculate the first candidate displacement at the current test time point based on the stiffness value and the target load at the current test time point when the target load at the current test time point is less than a preset load threshold; and to determine the second candidate displacement at the current test time point based on the reference set when the target load at the current test time point is greater than or equal to the preset load threshold.

[0064] The selection and control module is used to control the hydraulic cylinder device to apply a load to the aircraft tire at the current time point based on the first candidate displacement or the second candidate displacement.

[0065] The beneficial effects of this invention are as follows: This invention provides a high-precision load control method and system for aircraft tire testing. This application controls the hydraulic cylinder to apply load to the aircraft tire based on the amount of movement. To avoid damage to the aircraft tire and testing equipment during testing, this application first utilizes a dynamic stiffness calculation method, that is, using the measured stiffness value at the previous test time point as the initial stiffness value at the current test time point. After screening and smoothing, a first candidate displacement is calculated to ensure the smoothness of the stiffness curve and avoid large displacement changes caused by large stiffness variations. Furthermore, to avoid inflection point displacements during smoothing, this application also uses a set of data to calculate a second candidate displacement in the section with a large target load. Finally, the first or second candidate displacement is selected to execute the action based on the actual situation. When facing complex load curves, this application can effectively complete the load curve testing task, protect the aircraft tire and testing equipment, and accurately conform to the load curve for high-precision testing. Attached Figure Description

[0066] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0067] Figure 1 This is an application scenario diagram of a high-precision load control method for aircraft tire testing, as shown in one embodiment of this application;

[0068] Figure 2 This is a flowchart illustrating a high-precision load control method for aircraft tire testing in one embodiment of this application;

[0069] Figure 3 This is a schematic diagram of some of the load curves in this application;

[0070] Figure 4 This is a catapult takeoff load control curve shown in this application;

[0071] Figure 5 This is a diagram of catapult takeoff displacement control shown in this application;

[0072] Figure 6 This is a structural diagram of a high-precision load control system for aircraft tire testing, shown in one embodiment of this application. Detailed Implementation

[0073] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0074] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the layers related to the present invention and are not drawn according to the actual number, shape and size of the layers in the actual implementation. In the actual implementation, the form, number and proportion of each layer can be arbitrarily changed, and the layer layout may also be more complex.

[0075] Numerous details are explored in the following description to provide a more thorough explanation of embodiments of the invention; however, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details.

[0076] Figure 1 This is an application scenario diagram of a high-precision load control method for aircraft tire testing, as shown in one embodiment of this application. Figure 1 As shown in this application, during the testing of aircraft tires, a motor drives a rotating drum, which in turn drives the aircraft tires to rotate. To simulate tire loads during takeoff or braking, this application also uses hydraulic cylinders to apply loads to the aircraft tires, simulating the forces such as gravity and impact on the aircraft.

[0077] Figure 2 This is a flowchart illustrating a high-precision load control method for aircraft tire testing, as shown in one embodiment of this application. Figure 1 As shown: A high-precision load control method for aircraft tire testing according to this embodiment may include steps S210 to S240:

[0078] S210, Obtain the load curve, which includes the target load at multiple test time points;

[0079] The load curve is the target curve for the test, provided by the client. The load curve records the target load on the aircraft tire at multiple test time points. This application requires applying the target load to the aircraft tire at the corresponding time points.

[0080] Figure 3 This is a schematic diagram of some load curves in this application, such as... Figure 3As shown, the load curve has many inflection points. When applying load, if force control is used, the control opening of the servo valve is large when the load changes significantly. If tire stability is poor and a tire blowout occurs at this time, the valve opening may not be able to reverse in time due to the limited opening, causing damage to the equipment. Therefore, this application adopts displacement control in the general direction to avoid equipment damage.

[0081] However, during the test, the internal temperature and air pressure of the tire constantly change, leading to a continuous change in the tire's stiffness. Therefore, the relationship between the cylinder's displacement and the tire's load is constantly changing. Consequently, this application cannot use a fixed stiffness value for testing.

[0082] In view of this, this application adopts a dynamic real-time stiffness model calculation method, that is, using the measured stiffness value at the previous test time point to calculate the stiffness value at the next time point (the current time point).

[0083] S220: The measured stiffness value of the aircraft tire under load test at the previous test time point is used as the initial stiffness value of the aircraft tire at the current test time point. The initial stiffness value is then filtered and smoothed to obtain the stiffness value at the current time point. The load test of the aircraft tire is performed based on a preset hydraulic cylinder.

[0084] The dynamic real-time stiffness model calculation method adopted in this application uses the measured stiffness value of the aircraft tire at the previous test time point as the initial stiffness value of the aircraft tire at the current test time point. The overall control strategy is to measure and calculate point by point (the refresh cycle can be set), and obtain the control command for the next loading point in real time. The specimen stiffness at the current loading point is calculated in real time, and the target force value at the next moment and the measured acceleration value are used to calculate the target command for the displacement closed loop of the MOOG controller at the next moment. This target command is transmitted to the MOOG controller in real time through the DA output channel of the FPGA.

[0085] In this application, the previous test time point can be any test time point other than the last test time point. If the previous test time point is the first test time point, the static stiffness conversion method is used to obtain the measured stiffness value. The static stiffness conversion method is to pre-pressurize the test tire to make the load reach the target load and obtain the relationship between load and displacement. Thus, the measured stiffness value of the first test time point is obtained.

[0086] Except for the first test time point, in subsequent tests, the measured value of the previous test time point is used as the initial stiffness value for the current test time point. This initial stiffness value is then filtered, smoothed, and calculated to obtain the displacement control value. After displacement control, the measured load and displacement at the current test time point are obtained, leading to the measured stiffness value for that time point, which then provides the initial stiffness value for the next test time point. This process is repeated to complete the test cyclically. Furthermore, since the tire temperature change between adjacent time points is small, the stiffness value is relatively accurate, minimizing significant test errors.

[0087] In one embodiment of this application, the mathematical expression for the initial stiffness value is:

[0088]

[0089] In the formula, S i F' represents the initial stiffness value of the aircraft tire at the current test time. i-1 The measured load at the previous test time point, D′ i-1 D represents the measured displacement of the hydraulic cylinder at the previous test time point. zero This refers to the displacement of the hydraulic cylinder at its zero-point position when it just makes contact with the aircraft tire.

[0090] After obtaining the initial stiffness value, there is a possibility that the test data at the previous test time point was affected by noise, resulting in a significantly erroneous stiffness calculation. This could lead to a larger displacement control value, causing the control to exceed the normal control range and potentially damaging the specimen and equipment. Therefore, this application sets a screening range to filter the initial stiffness value.

[0091] Furthermore, to prevent large load fluctuations caused by the tire not bearing a certain load in the early stages of load control, which could affect the control effect, the range of actual stiffness values ​​is considered in the early stages of load control. As the load increases, the allowable range of stiffness can be increased. In other words, this application constructs a dynamic screening range to screen the initial stiffness value. For the initial stiffness value at the beginning of the test, the screening range is small to avoid large stiffness errors. As the test progresses and the load on the tire increases, since the baseline stiffness value is large at this point, large stiffness errors will not occur. At this time, the screening range is gradually widened to improve test efficiency.

[0092] In one embodiment of this application, the method for constructing the dynamic filtering range includes:

[0093] (1) Construct the initial filtering range, where the lower limit of the initial filtering range is... The upper limit of the initial filter range is

[0094] (2) In the segment where the target load is greater than or equal to the preset load threshold, execute cyclically within the target time period. until Among them, S Init is the initial stiffness value of the aircraft tire, and n is the number of cycles;

[0095] (3) In the segment where the target load is less than the preset load threshold, execute cyclically within the target time period. until

[0096] (4) Based on the upper limit value and the lower limit of the change Build a dynamic filtering range.

[0097] This application primarily aims to prevent the occurrence of very low stiffness values ​​in the early stages, which could lead to a large displacement of the cylinder output shaft and directly damage the tire. Therefore, the lower limit of the dynamic screening range is initially increased. For example, the initial screening range is (1, 10), and then it can be gradually adjusted to (0.3, 10) as the test progresses.

[0098] The stiffness range value should change continuously without abrupt changes. Therefore, the stiffness range value change is divided into n levels and gradually changed to the target value in a timed loop.

[0099] In this embodiment, the load curve is relatively flat and low in the early stage. Later, the load changes significantly and becomes higher to simulate the aircraft takeoff process. Therefore, the section where the target load is greater than or equal to the preset load threshold can be considered the initial stage of the test, and the section where the target load is less than the preset load threshold can be considered the later stages such as aircraft catapult takeoff.

[0100] After obtaining the dynamic filtering range, the initial stiffness value at the current test time point is filtered based on the pre-constructed dynamic filtering range;

[0101] When the initial stiffness value at the current test time point falls within the dynamic screening range, the initial stiffness value at the current test time point is smoothed based on the stiffness values ​​at multiple time points prior to the current test time point to obtain the stiffness value at the current test time point.

[0102] Among them, if If the initial stiffness value at the current test time point falls within the dynamic screening range, then the initial stiffness value is valid.

[0103] Because the stiffness values ​​calculated from load and displacement contain noise interference, they will fluctuate. If this value is used for control, according to the stiffness formula for load and displacement, D = F / S, the resulting displacement control will fluctuate, amplifying the fluctuating load and further amplifying the fluctuating stiffness value, causing jitter and divergence, ultimately leading to uncontrollable fluctuations. Therefore, it is necessary to filter the stiffness values ​​to obtain a smooth stiffness curve. Thus, in this application, after screening, it is also necessary to smooth the initial stiffness value at the current test time point based on the stiffness values ​​from multiple time points prior to the current test time point. Specifically, this includes:

[0104] (1) The stiffness value at the current test time point and the measured stiffness values ​​at multiple time points prior to the current test time point are placed in a set, and the mathematical expression of the set is: S={S' i-(n-1) ,S' i-(n-2) …S' i}

[0105] The smoothing methods implemented in this application include mean filtering and glide filtering. Mean filtering requires a sufficient number of measured stiffness values. Therefore, if the number of elements in the set is less than n', it is insufficient to complete the corresponding mean filtering. This application fills the beginning of the set with multiple elements that are the target stiffness values, such as multiple elements with a measured stiffness value of 1, so that the number of elements in the set is greater than or equal to n', where n' is the length of the mean filtering process.

[0106] (2) Perform mean filtering and sliding filtering of various lengths on multiple elements in the set to obtain multiple filtering results. The mathematical expression for mean filtering is:

[0107]

[0108] In the formula, This is the result of mean filtering;

[0109] The mathematical expression for slip filtering is:

[0110]

[0111] In the formula, This is the result of the sliding filter, where x is the proportional value;

[0112] During the experiment, the load fluctuated significantly within a certain load range. To prevent load control jitter, the stiffness value within a certain load range was filtered to reduce noise input. However, this resulted in phase lag when the load changed rapidly under high load. Therefore, after exceeding a certain load threshold, the filtering coefficient was reduced to decrease the phase lag effect caused by filtering.

[0113] This application primarily provides mean filtering with three lengths: n' = 2, n' = 10, and n' = 25; therefore, the result of the mean filtering is...

[0114] The reason for providing mean filters or slip filters of different lengths is that this application uses hydraulic cylinders of varying precision to provide the load. For example, the hydraulic cylinders in horizontal positions have lower precision, so a combination of lengths of 25 and 2 is used; the hydraulic cylinders in vertical positions have higher precision, so a combination of mean filters of lengths of 10 and 2 is used; and the catapult launch test in the vertical position uses a combination of length 10 and slip filters. Therefore, the stiffness set is selected according to the different positions of the equipment.

[0115]

[0116] The reason for using a combination of at least two filters is that the load curve in this application is a gentle curve at the beginning, which can be handled by a longer mean filter with good fit. However, there are many steep and abrupt changes in the latter part, so using a longer mean filter would introduce a large error. Therefore, a mean filter with a length of 2 or a sliding filter is used for processing.

[0117] (3) Determine the progress of the preset filtering and smoothing process at the current test time point, and combine the mean filtering result and the slip filtering result based on the progress of the preset filtering and smoothing process at the current test time point and the type of hydraulic cylinder equipment to obtain the stiffness value at the current test time point.

[0118] Furthermore, since a filtering method with a length of 25 or 10 is used in the flat parts of the load curve, while a length of 2 or a sliding filter is used in the steep parts, a sudden change in stiffness value is likely to occur when these two methods are transitioned without smoothing. Therefore, this application also performs filtering smoothing processing for different workstations to smoothly transition between the filtering methods at different stages. Specifically, as follows:

[0119] In this application, the filtering and smoothing process is used to smoothly switch from one filtering method to another during the test. If it is a horizontal workstation, it is smoothed from a mean filter with a length of 25 to a mean filter with a length of 2; if it is a vertical workstation, it is smoothed from a mean filter with a length of 10 to a sliding filter.

[0120] Specifically, the filtering and smoothing process includes:

[0121] (1) In the segment where the target load is greater than or equal to the preset load threshold, execute cyclically within the target time period. until

[0122] in, S represents the progress of the preset filtering and smoothing process at the current test time point. Init％ S is the initial value for the progress. min％ The final progress value is ΔS%, where ΔS% is the progress change. n is the number of iterations;

[0123] (2) In the segment where the target load is less than the preset load threshold, execute cyclically within the target time period. until

[0124] In the above process, the load threshold F is used Limit To distinguish between gentle sections and steep sections, i.e., F i ≥F Limit :implement until F i <F Limit :implement until

[0125] Specifically, S Init％ Generally, 100% is taken, S min％ Generally, it is taken as 0%. That is to say, this application only needs to be in F... i ≥F Limit Within that section, for a period of time, A gradual transition from 100% to 0%. This is achieved simply by using F... i <F Limit Within that section, for a period of time, The transition from 0% to 100% is gradual. Here... This refers to the proportion of mean filters with a length of 25 or a length of 10. This refers to the proportion of mean filtering or sliding filtering with a length of 25. Therefore, when calculating the stiffness value at the current time point, it is also necessary to consider the progress of the filtering and smoothing process at the current time point, for example, the distance from the current time point to F. i ≥F Limit The time point is 2s, and the nth iteration of each loop is 0.1s. Therefore, the current time point is at 20% of the filtering and smoothing process. The value is 20%.

[0126] Based on the above principles and considering different workstations, the mathematical expression for the stiffness value at the current test time point is as follows:

[0127]

[0128] In the formula, The first candidate stiffness value, This is the result of mean filtering with a length of n'1. This is the result of mean filtering with a length of n'2. This is the second candidate stiffness value. The result of mean filtering with length n'3

[0129] Specifically, n'1 = 25, n'2 = 2, and n'3 = 10. That is to say, To smooth the transformation from a mean filter with a length of 25 to a mean filter with a length of 2 when performing tests at a horizontal workstation. When performing tests on vertical workstations, the filter is smoothly transformed from a mean filter with a length of 10 to a sliding filter.

[0130] This means that different candidate stiffness values ​​are selected based on different workstations to obtain stiffness data suitable for the current equipment.

[0131] Furthermore, the mean filtering length described above is only for illustrative purposes in this embodiment. This application does not limit this; in other embodiments, mean filtering with any length from 1 to infinity can be selected according to actual needs.

[0132] In the above process, the stiffness value at the current test time point is obtained using the dynamic stiffness model calculation method, dynamic screening range, and smoothing processing. Therefore, using the stiffness value at the current test time point and the target load at the current time point, the displacement to be controlled by the hydraulic cylinder can be obtained. In the smooth section, the displacement calculated using the stiffness value at the current test time point and the target load at the current test time point is directly used for control.

[0133] However, due to stiffness fluctuations, displacement control fluctuations can occur. Therefore, the above-mentioned filtering method is used to filter the stiffness value. However, this method results in a phase difference between the actual load and the target load, which makes it impossible to conduct tests such as catapult launch test load reversal time too fast. Therefore, it is necessary to store the load and displacement data set of the completed curves and then directly perform interpolation calculations on the data set using the target load to solve the phase lag problem.

[0134] Figure 4 The catapult takeoff load control curve shown in this application is as follows: Figure 4 As shown, the blue curve is the load curve, and the red curve is the actual load output curve. In the early, flat phase, using the stiffness value at the current test time point to calculate and control the displacement closely matches the load curve. However, in the steep phase, the red curve significantly exceeds the blue curve.

[0135] Figure 5The catapult takeoff displacement control curve shown in this application is as follows: Figure 5 As shown, after filtering, the phase difference causes the third target peak to correspond to the trough of stiffness, resulting in a larger calculated displacement output, which makes the actual load too large.

[0136] To address the aforementioned issues, this application employs an alternative control method to calculate displacement in steep transition sections such as catapult launch. Specifically, it stores the force and stiffness during the first peak ascent phase in a table, allowing subsequent target forces to be controlled by searching for the closest value in the table. The specific process is as follows:

[0137] S230, construct a reference data set based on test execution data from multiple test time points prior to the current test time point, wherein the reference data set includes the executed target loads and the displacements corresponding to the executed target loads from multiple test time points prior to the current test time point;

[0138] In one embodiment of this application, a reference dataset is constructed based on test execution data from multiple test time points prior to the current test time point, including:

[0139] S231, obtain the executed target loads and displacements of the executed target loads at multiple test time points prior to the current test time point;

[0140] S232, construct an initial load set, and compare all executed target loads with the initial load set in order. If the executed target load is greater than any element in the initial load set, put the executed target load into the load set to obtain the load set.

[0141] Specifically, the initial value is first assigned to the comparison value during the process for judgment, i.e., F' Init =F' Compare ;F' Init The initial value of the executed load; then if F' Compare ≤F' i Then execute F' i Write it into the data set.

[0142] F(i)→{F′0,F′1,F′2…F′ i}

[0143] F(i)=F′ Compare

[0144] If, F' Compare ≥F' i No action is taken.

[0145] The above process stores all executed payloads used in the first peak rise phase in a dataset, ensuring that there are no duplicate executed payloads within the dataset. This saves device cache space.

[0146] S233, construct a displacement set based on the displacement of each executed target load in the load set;

[0147] The actual load data set is as follows:

[0148] F′ (i) ={F′0,F′1,F′2…F′ i}

[0149] Simultaneously store the corresponding actual displacement value:

[0150] D′ (i) ={D′0,D′1,D′2…D′ i}

[0151] S234, construct a reference set based on the load set and the displacement set.

[0152] S240, when the target load at the current test time point is less than the preset load threshold, calculate the first candidate displacement at the current test time point based on the stiffness value and the target load at the current test time point; when the target load at the current test time point is greater than or equal to the preset load threshold, determine the second candidate displacement at the current test time point based on the reference set.

[0153] Based on the analysis above, this application divides the load curve into a smooth part and a steep part. The smooth part directly uses the stiffness value at the current test time point and the target load at the current test time point to calculate the first candidate displacement.

[0154] The mathematical expression for the first candidate displacement at the current test time point is:

[0155]

[0156] In the formula, C T C is the first adjustment parameter. f This is the second adjustment parameter. This represents the stiffness value of the aircraft tire at the current test time. First adjustment parameter C. T Second adjustment parameter C f The settings allow for manual adjustment during actual operation.

[0157] In the steeper sections, the second candidate displacement for the current test time point is determined based on the reference data set, specifically including:

[0158] (1) If there is an executed load in the reference set that is consistent with the target load at the current test time point, the displacement corresponding to the executed load that is consistent with the target load at the current test time point shall be taken as the second candidate displacement at the current test time point.

[0159] (2) If there is no executed load in the reference set that matches the target load at the current test time point, two executed loads that meet the target conditions are taken from the reference set, and interpolation is performed based on the displacement of the two executed loads that meet the target conditions to obtain the second candidate displacement at the current test time point. The target conditions include: the executed load F' (n) Executed load F' (n+1) The target load F at the current time point i Closest, and F' (n) <F i <F' (n+1) .

[0160] In one embodiment of this application, the mathematical expression for the interpolation operation is:

[0161]

[0162] In the formula, D' is the second candidate displacement at the current test time point. (n+1) For the executed load F' (n+1) The corresponding displacement, D' (n) For the executed load F' (n) The corresponding displacement.

[0163] In the above process, the already executed displacement is used directly or interpolated to obtain the second candidate displacement at the current test time point. Although there is a time difference between these two points, which inevitably leads to errors in the stiffness value, the phase difference introduced by filtering can be effectively eliminated. In practice, the displacement error is actually reduced, resulting in the output actual load curve closely matching the target load curve.

[0164] S250 controls the hydraulic cylinder device to apply load to the aircraft tire at the current time point based on the first candidate displacement or the second candidate displacement.

[0165] Finally, the first candidate displacement D at the current test time point was calculated in the previous text. i Second candidate displacement To further ensure equipment safety and testing accuracy, this application ultimately selects the following modules:

[0166] F(i) < F Limit ,but

[0167] F(i)≥F Limit ,

[0168] F(i)≥F' (max) ←{F'0,F'1,F'2…F' i}but

[0169] F(i)<F′ (max) ←{F′0,F′1,F′2…F′ i}

[0170] but

[0171]

[0172] but

[0173] but

[0174] The corresponding explanation is as follows:

[0175] (1) When the target load at the current test time point is less than the preset load threshold (i.e., F(i) < F), Limit (At time), based on the first candidate displacement D i Construction displacement control quantity And based on displacement control quantity The hydraulic cylinder device applies load to the aircraft tire, where C -1 This is the third adjustment parameter; the third adjustment parameter C -1 The settings allow for manual adjustment of the corresponding displacement.

[0176] (2) The target load at the current test time point is greater than or equal to the preset load threshold (i.e., F(i) ≥ F). Limit And the target load at the current test time point is greater than or equal to the maximum executed load in the reference set (i.e., F(i) ≥ F'). (max) ←{F'0,F'1,F'2…F' i When}), based on the first candidate displacement D i Construction displacement control quantity And based on displacement control quantity The hydraulic cylinder device applies a load to the aircraft tire, where C1 is the fourth adjustment parameter; setting the fourth adjustment parameter C1 facilitates manual adjustment of the corresponding displacement. Furthermore, after execution, F'(i) is placed into the reference set.

[0177] (3) The target load at the current test time point is greater than or equal to the preset load threshold (i.e., F(i) ≥ F). Limit The target load at the previous test time point is less than the maximum executed load in the reference set (F(i) < F′). (max) ←{F′0,F′1,F′2…F′ i}), and the first candidate displacement D i With the second candidate displacement The difference At that time, based on the second candidate displacement Construction displacement control quantity And based on displacement control quantity The hydraulic cylinder device applies load to the aircraft tire, where C3 is the fifth adjustment parameter;

[0178] (4) The target load at the current test time point is greater than or equal to the preset load threshold (i.e., F(i) ≥ F). Limit The target load at the current test time point is less than the maximum executed load (F(i)) in the reference set. <F′ (max) ←{F′0,F′1,F′2…F′ i}), the first candidate displacement D i With the second candidate displacement The difference and When the first candidate displacement Di is used as the displacement control quantity, And based on displacement control quantity The hydraulic cylinder device applies load to the aircraft tire; if Then the smaller one is selected as the displacement, i.e. This ensures the safety of tires and equipment to the greatest extent possible.

[0179] (5) The target load at the current test time point is greater than or equal to the preset load threshold, i.e., F(i) ≥ F Limit The target load at the current test time point is less than the maximum executed load in the reference set (F(i) < F′). (max) ←{F′0,F′1,F′2…F′ i}), the first candidate displacement D i With the second candidate displacement The difference and At that time, based on the second candidate displacement Construction displacement control quantity And based on displacement control quantity The hydraulic cylinder system applies load to the aircraft tires, where C2 is the sixth adjustment parameter. If... Then select the smaller one and increase the adjustment parameter as the displacement, that is... This ensures the safety of tires and equipment to the greatest extent possible.

[0180] In the above process, this application employs a dynamic stiffness model calculation method, dynamic screening range, and smoothing processing to obtain the stiffness value at the current test time point for the smooth section of the load curve, and calculates the corresponding first candidate displacement. For the steep phase of catapult takeoff, a reference set is established, and the corresponding displacement is found to obtain the second candidate displacement. Finally, a dynamically changing displacement curve is obtained to achieve the control effect of the target load.

[0181] This invention discloses a high-precision load control method for aircraft tire testing. This application uses displacement to control the hydraulic cylinder to apply load to the aircraft tire. To avoid damage to the aircraft tire and testing equipment during testing, this application first utilizes a dynamic stiffness calculation method. Specifically, it uses the measured stiffness value from the previous test time point as the initial stiffness value for the current test time point. After screening and smoothing, a first candidate displacement is calculated to ensure a smooth stiffness curve and avoid large displacement changes caused by significant stiffness variations. Furthermore, to avoid inflection point displacements during smoothing, this application also uses a dataset to calculate a second candidate displacement in areas with large target loads. Finally, the first or second candidate displacement is selected to execute the action based on the actual situation. When faced with complex load curves, this application can effectively complete the load curve testing task, protect the aircraft tire and testing equipment, and accurately conform to the load curve for high-precision testing.

[0182] like Figure 6 As shown, this application also provides a high-precision load control system for aircraft tire testing, comprising:

[0183] An acquisition module is used to acquire load curves, wherein the load curves include target loads at multiple test time points;

[0184] The first processing module is used to take the measured stiffness value of the aircraft tire at the previous test time point as the initial stiffness value of the aircraft tire at the current test time point, and to filter and smooth the initial stiffness value to obtain the stiffness value at the current time point. The load test of the aircraft tire is performed based on a preset hydraulic cylinder.

[0185] The second processing module is used to construct a reference set based on the test execution data of multiple test time points before the current test time point, wherein the reference set includes the executed target loads and the displacements corresponding to the executed target loads at multiple test time points before the current test time point;

[0186] The calculation module is used to calculate the first candidate displacement at the current test time point based on the stiffness value and the target load at the current test time point when the target load at the current test time point is less than a preset load threshold; and to determine the second candidate displacement at the current test time point based on the reference set when the target load at the current test time point is greater than or equal to the preset load threshold.

[0187] The selection and control module is used to control the hydraulic cylinder device to apply a load to the aircraft tire at the current time point based on the first candidate displacement or the second candidate displacement.

[0188] This invention discloses a high-precision load control system for aircraft tire testing. This application uses displacement to control the hydraulic cylinder to apply load to the aircraft tire. To avoid damage to the aircraft tire and testing equipment during testing, this application first utilizes a dynamic stiffness calculation method. Specifically, it uses the measured stiffness value from the previous test time point as the initial stiffness value for the current test time point. After screening and smoothing, a first candidate displacement is calculated to ensure a smooth stiffness curve and avoid large displacement changes caused by significant stiffness variations. Furthermore, to avoid inflection point displacements during smoothing, this application also uses a dataset to calculate a second candidate displacement in areas with large target loads. Finally, the first or second candidate displacement is selected to execute the action based on the actual situation. When faced with complex load curves, this application can effectively complete the load curve testing task, protect the aircraft tire and testing equipment, and accurately conform to the load curve for high-precision testing.

[0189] This embodiment also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements any one of the methods in this embodiment, wherein the method is the execution logic of this system.

[0190] This embodiment also provides an electronic terminal, including: a processor and a memory;

[0191] The memory is used to store computer programs, and the processor is used to execute the computer programs stored in the memory so that the terminal performs any of the methods in this embodiment.

[0192] As will be understood by those skilled in the art, the computer-readable storage medium described in this embodiment allows for the implementation of all or part of the steps in the above method embodiments by computer program-related hardware. The aforementioned computer program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0193] The electronic terminal provided in this embodiment includes a processor, a memory, a transceiver, and a communication interface. The memory and the communication interface are connected to the processor and the transceiver and complete communication between them. The memory is used to store computer programs, the communication interface is used to perform communication, and the processor and the transceiver are used to run the computer programs, so that the electronic terminal performs the steps of the above method.

[0194] In this embodiment, the memory may include random access memory (RAM) and may also include non-volatile memory, such as at least one disk storage device.

[0195] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0196] In the above embodiments, although the invention has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. The embodiments of the invention are intended to cover all such substitutions, modifications, and variations falling within the broad scope of the appended claims.

[0197] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A high-precision load control method for aircraft tire testing, characterized in that, Including the following steps: Obtain the load curve, wherein the load curve includes the target load at multiple test time points; The measured stiffness value of the aircraft tire subjected to a load test at the previous test time point is used as the initial stiffness value of the aircraft tire at the current test time point. The initial stiffness value is then filtered and smoothed to obtain the stiffness value at the current time point. The load test of the aircraft tire is performed based on a preset hydraulic cylinder. The filtering and smoothing of the initial stiffness value includes: filtering the initial stiffness value at the current test time point based on a pre-constructed dynamic filtering range; and when the initial stiffness value at the current test time point falls into the dynamic filtering range, smoothing the initial stiffness value at the current test time point based on the stiffness values ​​of multiple time points prior to the current test time point to obtain the stiffness value at the current test time point. A reference set is constructed based on test execution data from multiple test time points prior to the current test time point. The reference set includes the executed target loads and the displacements corresponding to the executed target loads from multiple test time points prior to the current test time point. When the target load at the current test time point is less than a preset load threshold, a first candidate displacement at the current test time point is calculated based on the stiffness value and the target load at the current test time point; when the target load at the current test time point is greater than or equal to the preset load threshold, a second candidate displacement at the current test time point is determined based on the reference set; the mathematical expression for the first candidate displacement at the current test time point is: In the formula, The target load at the current test time point, This is the first adjustment parameter. This is the second adjustment parameter. This represents the stiffness value of the aircraft tire at the current test time. The displacement of the hydraulic cylinder at its zero-point position when it just contacts the aircraft tire; determining the second candidate displacement at the current test time point based on the reference set includes: when there is an executed load in the reference set that is consistent with the target load at the current test time point, taking the displacement corresponding to the executed load that is consistent with the target load at the current test time point as the second candidate displacement at the current test time point. If no executed load in the reference set is consistent with the target load at the current test time point, two executed loads that satisfy the target conditions are retrieved from the reference set, and interpolation is performed based on the displacements of the two executed loads that satisfy the target conditions to obtain the second candidate displacement at the current test time point. The target conditions include: executed payload. Executed payload Target payload at the current time point closest, and ; Based on the first candidate displacement or the second candidate displacement, the hydraulic cylinder is controlled to apply a load to the aircraft tire at the current time point.

2. The high-precision load control method for aircraft tire testing according to claim 1, characterized in that, The initial stiffness value at the current test time point is determined based on the target load and displacement of the cylinder at the current test time point. The displacement at the current test time point is determined based on the target load at the current test time point and the stiffness value at the previous test time point. The stiffness value at the first test time point is determined through a static stiffness value test. The mathematical expression for the initial stiffness value is: In the formula, This represents the initial stiffness value of the aircraft tire at the current test time. The measured load at the previous test time point, This represents the measured displacement of the hydraulic cylinder at the previous test time point. This is the displacement of the hydraulic cylinder at its zero point when it just makes contact with the aircraft tire.

3. The high-precision load control method for aircraft tire testing according to claim 1, characterized in that, The method for constructing the dynamic filtering range includes: Construct an initial filtering range, wherein the lower limit of the initial filtering range is... The upper limit of the initial filtering range is ; In the segment where the target load is greater than or equal to the preset load threshold, the process is executed cyclically within the target time period. ,until = , ,in, This represents the initial stiffness value of the aircraft tire. This represents the number of loop iterations. In the segment where the target load is less than the preset load threshold, the process is executed cyclically within the target time period. ,until = ; Based on the upper limit value and the lower limit of the change Build a dynamic filtering range.

4. The high-precision load control method for aircraft tire testing according to claim 1, characterized in that, The initial stiffness value at the current test time point is smoothed based on the stiffness values ​​at multiple time points prior to the current test time point, including: The stiffness value at the current test time point and the measured stiffness values ​​at multiple previous test time points are placed in a set, and the number of elements in the set is less than [a certain value]. At this time, the beginning of the set is filled with multiple elements representing the target stiffness value, so that the number of elements in the set is greater than or equal to the target stiffness value. ,in, The length for performing mean filtering; Multiple mean filters and sliding filters of various lengths are applied to multiple elements in the set to obtain multiple filtering results. The mathematical expression for the mean filter is: In the formula, This is the result of mean filtering; The mathematical expression for the slip filter is: In the formula, The result of the sliding filter. This is a proportional value; The progress of the preset filtering and smoothing process at the current test time point is determined, and based on the progress of the preset filtering and smoothing process at the current test time point and the cylinder type, the mean filtering result and the slip filtering result are combined to obtain the stiffness value at the current test time point.

5. The high-precision load control method for aircraft tire testing according to claim 4, characterized in that, The filtering smoothing process is used to smoothly switch from one filtering method to another during the experiment. The filtering smoothing process includes: In the segment where the target load is greater than or equal to the preset load threshold, the process is executed cyclically within the target time period. ,until = ,in, This represents the progress of the preset filtering and smoothing process at the current test time point. This is the initial progress value. This is the end value of the progress. This represents the change in schedule. , This represents the number of loop iterations. In the segment where the target load is less than the preset load threshold, the process is executed cyclically within the target time period. %,until = .

6. The high-precision load control method for aircraft tire testing according to claim 4, characterized in that, The stiffness value at the current test time point The mathematical expression is: In the formula, The first candidate stiffness value, For length is The mean filtering result, For length is The mean filtering result, This is the second candidate stiffness value. For length is The mean filtering result.

7. The high-precision load control method for aircraft tire testing according to claim 1, characterized in that, A reference dataset is constructed based on test execution data from multiple test time points prior to the current test time point, including: Obtain the executed target loads and displacements of the executed target loads at multiple test time points prior to the current test time point; Construct an initial load set, and compare all executed target loads with the initial load set in sequence. If an executed target load is greater than any element in the initial load set, add the executed target load to the load set to obtain the load set. A displacement set is constructed based on the displacement of each executed target load in the load set; A reference set is constructed based on the load set and the displacement set.

8. The high-precision load control method for aircraft tire testing according to claim 1, characterized in that, The mathematical expression for the interpolation operation is: In the formula, This is the second candidate displacement at the current test time point. For executed payloads The corresponding displacement, For executed payloads The corresponding displacement.

9. The high-precision load control method for aircraft tire testing according to claim 1, characterized in that, Controlling the hydraulic cylinder to apply a load to the aircraft tire at the current time point based on the first candidate displacement or the second candidate displacement includes: When the target load at the current test time point is less than the preset load threshold, based on the first candidate displacement... Construction displacement control quantity , And based on displacement control quantity The hydraulic cylinder is controlled to apply a load to the aircraft tire, wherein, This is the third adjustment parameter; When the target load at the current test time point is greater than or equal to a preset load threshold, and the target load at the current test time point is greater than or equal to the maximum executed load in the reference set, based on the first candidate displacement... Construction displacement control quantity , And based on displacement control quantity The hydraulic cylinder is controlled to apply a load to the aircraft tire, wherein, This is the fourth adjustment parameter; The target load at the current test time point is greater than or equal to a preset load threshold, the target load at the current test time point is less than the maximum executed load in the reference set, and the first candidate displacement... With the second candidate displacement The difference At that time, based on the second candidate displacement Construction displacement control quantity , And based on displacement control quantity The hydraulic cylinder is controlled to apply a load to the aircraft tire, wherein, This is the fifth adjustment parameter; If the target load at the current test time is greater than or equal to a preset load threshold, and the target load at the current test time is less than the maximum executed load in the reference set, the first candidate displacement... With the second candidate displacement The difference ,and At that time, the first candidate displacement amount As displacement control quantity And based on displacement control quantity The hydraulic cylinder is controlled to apply load to the aircraft tire; If the target load at the current test time is greater than or equal to a preset load threshold, and the target load at the current test time is less than the maximum executed load in the reference set, the first candidate displacement... With the second candidate displacement The difference ,and At that time, based on the second candidate displacement Construction displacement control quantity , And based on displacement control quantity The hydraulic cylinder is controlled to apply a load to the aircraft tire, wherein, This is the sixth adjustment parameter.

10. A high-precision load control system for aircraft tire testing, employing the high-precision load control method for aircraft tire testing as described in claim 1, characterized in that... include: An acquisition module is used to acquire load curves, wherein the load curves include target loads at multiple test time points; The first processing module is used to take the measured stiffness value of the aircraft tire at the previous test time point as the initial stiffness value of the aircraft tire at the current test time point, and to filter and smooth the initial stiffness value to obtain the stiffness value at the current time point. The load test of the aircraft tire is performed based on a preset hydraulic cylinder. The second processing module is used to construct a reference set based on the test execution data of multiple test time points before the current test time point, wherein the reference set includes the executed target loads and the displacements corresponding to the executed target loads at multiple test time points before the current test time point; The calculation module is used to calculate the first candidate displacement at the current test time point based on the stiffness value and the target load at the current test time point when the target load at the current test time point is less than a preset load threshold; and to determine the second candidate displacement at the current test time point based on the reference set when the target load at the current test time point is greater than or equal to the preset load threshold. The selection and control module is used to control the hydraulic cylinder to apply a load to the aircraft tire at the current time point based on the first candidate displacement or the second candidate displacement.

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