Self-adaptive wind load passive mitigation design method based on threshold triggering

Abstract

The invention relates to a self-adaptive wind load passive slowing-down design method based on threshold triggering. The method comprises the steps that aerodynamic parameters during non-load-shedding are calculated according to a nominal program angle; calculating an initial load shedding program angle ideal value; when the flight Mach number is within the allowable load shedding range and the qalpha value exceeds the current amplitude limiting value, load shedding is carried out; only the part exceeding the qalpha amplitude limiting value is subjected to load shedding; and carrying out amplitude limiting processing on the angle correction of the load shedding program in combination with the dynamic characteristics and maneuverability of the rocket body. According to the method, the load shedding opportunity is triggered through the qalpha amplitude limiting value, amplitude limiting processing is carried out on the load shedding program angle and the angular velocity correction amount, the structural strength of a rocket body can be fully utilized, the dynamic lag characteristic and the actual control capacity of the rocket are considered, the rocket body can track the corrected program angle with high precision, and the method has high application value in engineering.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of launch vehicle trajectory design, and relates to a self-adaptive wind load passive reduction design method based on threshold triggering. BACKGROUND

[0002] Statistical data of high-altitude wind near the launch base of a launch vehicle show that the wind speed has obvious seasonal variation. If the launch vehicle encounters large high-altitude wind during the first-stage flight, the aerodynamic load will obviously increase. When developing a new type of rocket, the strength index allocation of each cabin section is based on the premise of load reduction, so the strength margin of the new type of rocket is smaller, and a more accurate load reduction method must be adopted during flight to improve the launch probability.

[0003] The passive load reduction of high-altitude wind has the following characteristics: if the load reduction is intervened too early, it may lead to excessive burden of the fall zone correction section; if the load reduction is intervened too late, it may lead to poor load reduction effect. In the development process of batch wind field load reduction of a new type of rocket, if the previous idea of prior load reduction is adopted: the fixed load reduction coefficient change curve is not necessarily suitable for different wind profiles that change frequently. If the load reduction coefficient curve is optimized for each wind, the simulation speed is too slow. Therefore, a self-adaptive load reduction method needs to be developed to improve the rapidity and flexibility of load reduction. SUMMARY

[0004] The technical problem solved by the application is to overcome the shortcomings of the prior art and provide a self-adaptive wind load passive reduction design method based on threshold triggering, which fully utilizes the strength of the rocket body to track the corrected program angle with high accuracy and improve the rapidity and flexibility of load reduction.

[0005] The technical solution of the application is:

[0006] A self-adaptive wind load passive reduction design method based on threshold triggering, comprising:

[0007] calculating the aerodynamic parameters when there is no load reduction according to the nominal program angle;

[0008] when the flight Mach number is within the allowable load reduction range and the qα value exceeds the current amplitude limit value, load reduction is performed, and an initial load reduction program angle ideal value is calculated; q is the dynamic pressure, and α is the aerodynamic angle of attack considering the moment balance and guidance;

[0009] The load reduction program angle correction amount is limited in amplitude in combination with the dynamic characteristics and maneuvering ability of the rocket body to obtain the actual load reduction program angle.

[0010] Preferably, the aerodynamic parameters when there is no load reduction are calculated according to the nominal program angle, and the calculation is specifically as follows:

[0011] Δα f = α1- α0

[0012] Δα ph = α - α0

[0013] Δβ f = β1- β0

[0014] Δβ ph = β - β0

[0015] wherein Δα f is the additional angle of attack caused by the high altitude wind, Δα ph is the angle of attack error considering aerodynamic balance and guidance; α0 represents the ideal ground speed angle of attack generated by the rocket relative to the ground speed, α1 represents the ideal aerodynamic angle of attack generated by the rocket relative to the airflow speed, and α represents the aerodynamic angle of attack considering the moment balance and guidance; Δβ f is the additional sideslip angle caused by the high altitude wind, Δβ ph is the sideslip angle error considering aerodynamic balance and guidance; β0 represents the ideal ground speed sideslip angle generated by the rocket relative to the ground speed, β1 represents the ideal aerodynamic sideslip angle generated by the rocket relative to the airflow speed, and β represents the aerodynamic sideslip angle considering the moment balance and guidance.

[0016] Preferably, the initial load shedding procedure angle ideal value of the i-th step is calculated by using the following formula:

[0017]

[0018] respectively, the initial load shedding pitch procedure angle ideal value of the i-th step, the initial load shedding yaw procedure angle ideal value of the i-th step; and are the current nominal pitch angle, yaw angle and roll angle, and Δθ, Δσ respectively represent the trajectory inclination angle and trajectory deflection angle change caused by the high altitude wind; Δα f is the additional angle of attack caused by the high altitude wind, Δα ph is the angle of attack error considering aerodynamic balance and guidance; Δβ f is the additional sideslip angle caused by the high altitude wind, Δβ ph is the sideslip angle error considering aerodynamic balance and guidance; k relief is the load shedding coefficient.

[0019] Preferably,

[0020] wherein Ma l and Ma u are the lower and upper limits of the Mach number range, (qα) u is the upper limit of qα, and Ma is the current Mach number.

[0021] Preferably, the dynamic characteristics and maneuvering ability of the rocket body are represented by the rocket body angular acceleration limit.

[0022] Preferably, the correction amount of the load relief procedure angle is limited to obtain the actual load relief procedure angle, and the method is as follows:

[0023] (1) The pitch angle load relief angular velocity is calculated by using the following formula The yaw angle load relief angular velocity is calculated by using the following formula

[0024]

[0025] wherein, is the actual load relief pitch procedure angle of the i-1th step, is the actual load relief pitch procedure angle of the i-2th step; is the actual load relief yaw procedure angle of the i-1th step, is the actual load relief yaw procedure angle of the i-2th step; and Δt is the time interval between two steps.

[0026] (2) According to the dynamic characteristics and maneuvering ability of the arrow, the required value of the i th step pitch attitude adjustment amount is obtained The required value of the i th step yaw attitude adjustment amount δψ1is calculated, and the i th step load relief pitch procedure angle considering the angular acceleration limitation is calculated The i th step load relief yaw procedure angle is calculated

[0027]

[0028] wherein, is the initial load relief pitch procedure angle ideal value of the i th step, is the pitch angle limitation value obtained according to the angular acceleration limitation value, is the initial load relief yaw procedure angle ideal value of the i th step, δψ u is the yaw angle limitation value obtained according to the angular acceleration limitation value, When is positive, +1 is taken, and when it is negative, -1 is taken.

[0029] (3) The difference between the pitch angle load relief angular velocity and the nominal angular velocity is calculated The difference between the yaw angle load relief angular velocity and the nominal angular velocity is calculated

[0030]

[0031] wherein, is the nominal procedure angular velocity;

[0032] (4) The i th step actual load relief procedure angle considering the load relief damping correction coefficient is calculated

[0033] ​​​

[0034] Where, k damp This is the load reduction damping correction factor.

[0035] An adaptive passive wind load mitigation design system based on threshold triggering includes: an aerodynamic parameter calculation module, an initial load reduction program angle ideal value calculation module, and an actual load reduction program angle acquisition module;

[0036] Aerodynamic parameter calculation module: Calculates aerodynamic parameters without load reduction based on the nominal program angle. The aerodynamic parameters include the additional angle of attack caused by high-altitude wind, the qα value, and the aerodynamic angle error considering aerodynamic balance and guidance. q is the dynamic pressure, and α is the angle of attack considering torque balance and guidance.

[0037] Initial load reduction program angle ideal value calculation module: When the flight Mach number is within the allowable load reduction range and the qα value exceeds the current limit value, load reduction is performed, and the initial load reduction program angle ideal value is calculated;

[0038] Actual load reduction program angle acquisition module: Combining the dynamic characteristics and maneuverability of the rocket body, the load reduction program angle correction amount is limited to obtain the actual load reduction program angle.

[0039] Preferably, in the aerodynamic parameter calculation module, the aerodynamic parameters without load reduction are calculated based on the nominal program angle, as follows:

[0040] Δα f =α1-α0

[0041] Δα ph =α-α0

[0042] Δβ f =β1-β0

[0043] Δβ ph =β-β0

[0044] In the formula, Δα f Δα is the additional angle of attack caused by high-altitude winds. ph To account for aerodynamic balance and guidance angle-of-attack errors; α0 represents the ideal ground speed angle of attack generated by the rocket's velocity relative to the ground, α1 represents the ideal aerodynamic angle of attack generated by the rocket's velocity relative to the airflow, and α represents the aerodynamic angle of attack considering torque balance and guidance; Δβ f Δβ is the additional sideslip angle caused by high-altitude winds. ph To account for the sideslip angle error in aerodynamic balance and guidance; β0 represents the ideal ground speed sideslip angle generated by the rocket's velocity relative to the ground, β1 represents the ideal aerodynamic sideslip angle generated by the rocket's velocity relative to the airflow, and β represents the aerodynamic sideslip angle considering torque balance and guidance.

[0045] Preferably, the initial load reduction program angle ideal value calculation module calculates the ideal value of the initial load reduction program angle in step i using the following formula:

[0046]

[0047] These are the ideal values ​​of the pitch program angle and the yaw program angle for the initial load reduction in step i, respectively. and The nominal pitch, yaw, and roll angles at the current moment are given; Δθ and Δσ represent the changes in trajectory tilt and deviation caused by high-altitude winds, respectively; Δα f Δα is the additional angle of attack caused by high-altitude winds. ph To account for the angle of attack error in aerodynamic balance and guidance; Δβ f Δβ is the additional sideslip angle caused by high-altitude winds. ph To account for sideslip angle errors in aerodynamic balance and guidance; k relief This is the load reduction factor.

[0048] The preferred implementation method for the actual load reduction program angle acquisition module is as follows:

[0049] (1) Calculate the pitch angle and load reduction angular velocity using the following formula. Yaw angle and load reduction angular velocity :

[0050]

[0051] in, The actual pitch angle for the (i-1)th step of the load reduction program. The actual pitch angle for the load reduction procedure in step i-2; The actual yaw angle for the (i-1)th step of the load reduction procedure. Δt is the actual yaw angle for the (i-2)th step of load reduction; Δt is the time interval between the two steps.

[0052] (2) Based on the dynamic characteristics and maneuverability of the rocket body, obtain the required value of the pitch attitude adjustment for the i-th step. Yaw attitude adjustment required value Calculate the i-th step unloading pitch angle after considering angular acceleration limiting. Step i: Load reduction and yaw procedure angle :

[0053]

[0054] in, Let the initial load reduction pitch angle be the ideal value for the i-th step. The pitch angle limit value is obtained based on the angular acceleration limit value. Let δψ be the ideal value of the initial yaw angle for the i-th step of the load reduction procedure. u The yaw angle limit is obtained based on the angular acceleration limit. when When the result is positive, take +1; when the result is negative, take -1.

[0055] (3) Calculate the difference between the pitch angle unloading angular velocity and the nominal angular velocity. The difference between the yaw angle unloading angular velocity and the nominal angular velocity :

[0056]

[0057] in, The nominal program angular velocity;

[0058] (4) Calculate the actual load reduction procedure angle in step i, considering the load reduction damping correction coefficient.

[0059]

[0060] Where, k damp This is the load reduction damping correction factor.

[0061] The advantages of this invention compared to the prior art are:

[0062] This invention proposes an adaptive passive wind load mitigation design method based on threshold triggering. By changing the timing of load reduction intervention to be triggered by a qα threshold value, 100% load reduction is only performed when the qα value exceeds the current threshold (i.e., the load reduction coefficient is set to 1). This fully utilizes the rocket's strength and avoids premature intervention. Simultaneously, considering the rocket's dynamic hysteresis characteristics and actual control capabilities, damping is applied to the program angle correction based on the angular velocity deviation before and after load reduction, and the program angle correction is limited according to the upper limit of angular acceleration. This allows the rocket to track the corrected program angle with high accuracy, improving the speed and flexibility of load reduction. This method has high engineering application value.

[0063] The present invention proposes an adaptive passive wind load mitigation design method based on threshold triggering. The design is simple, adaptable to different types of launch vehicles, and easy to implement in engineering. Attached Figure Description

[0064] Figure 1 This is a flowchart of an adaptive passive wind load mitigation design method based on threshold triggering according to the present invention.

[0065] Figure 2 A comparison of the actual target-firing load reduction effects of the two load reduction models. Detailed Implementation

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

[0067] The present invention discloses an adaptive wind load passive mitigation design method based on threshold triggering. By changing the timing of load reduction intervention to be triggered by the qα limit value, and only when the qα value exceeds the current limit value, 100% load reduction is performed, that is, the load reduction coefficient is set to 1, so as to make full use of the rocket body strength and avoid premature intervention. At the same time, considering the dynamic hysteresis characteristics of the rocket and the actual control capability, the program angle correction amount is damped according to the angular velocity deviation before and after load reduction, and the program angle correction amount is limited according to the upper limit of angular acceleration, so that the rocket body can track the corrected program angle with high accuracy.

[0068] like Figure 1 As shown, this invention provides an adaptive passive wind load mitigation design method based on threshold triggering, comprising:

[0069] Step 1: Calculate the aerodynamic parameters without load reduction based on the nominal program angle. These parameters include the aerodynamic angle error caused by high-altitude winds, the qα value, and the aerodynamic angle error resulting from torque balance and guidance. q represents dynamic pressure, and α represents the angle of attack considering torque balance and guidance.

[0070] The aerodynamic parameters without load reduction are calculated based on the nominal program angle, as follows:

[0071] Δα f =α1-α0

[0072] Δα ph =α-α0

[0073] Δβ f =β1-β0

[0074] Δβ ph =β-β0

[0075] In the formula, Δα f Δα is the additional angle of attack caused by high-altitude winds. ph To account for aerodynamic balance and guidance angle-of-attack errors; α0 represents the ideal ground speed angle of attack generated by the rocket's velocity relative to the ground, α1 represents the ideal aerodynamic angle of attack generated by the rocket's velocity relative to the airflow, and α represents the aerodynamic angle of attack considering torque balance and guidance; Δβ f Δβ is the additional sideslip angle caused by high-altitude winds. ph To account for the sideslip angle error in aerodynamic balance and guidance; β0 represents the ideal ground speed sideslip angle generated by the rocket's velocity relative to the ground, β1 represents the ideal aerodynamic sideslip angle generated by the rocket's velocity relative to the airflow, and β represents the aerodynamic sideslip angle considering torque balance and guidance.

[0076] Step 2: Calculate the initial ideal value for the load reduction program angle. Load reduction is only performed when the flight Mach number is within the allowable load reduction range and the qα value exceeds the current limit. Here, load reduction is only performed on the portion exceeding the qα limit. The calculation of the initial ideal value needs to consider roll decoupling. The calculation of the initial ideal value needs to consider the trajectory tilt and trajectory deflection deviations caused by high-altitude winds. The calculation of the initial ideal value needs to consider a correction factor, which is determined by the proportion of the qα value exceeding the qα limit.

[0077] The ideal value of the initial unloading program angle in step i is calculated using the following formula:

[0078]

[0079] These are the ideal values ​​of the pitch program angle and the yaw program angle for the initial load reduction in step i, respectively. and The nominal pitch, yaw, and roll angles at the current moment are given; Δθ and Δσ represent the changes in trajectory tilt and deviation caused by high-altitude winds, respectively; Δα f Δα is the additional angle of attack caused by high-altitude winds. ph To account for the angle of attack error in aerodynamic balance and guidance; Δβ f Δβ is the additional sideslip angle caused by high-altitude winds. ph To account for sideslip angle errors in aerodynamic balance and guidance; k relief This is the load reduction factor.

[0080]

[0081] Among them, Ma l and Ma u Let (qα) be the lower and upper bounds of the Mach number range. u Let qα be the upper limit value, and Ma be the Mach number at the current moment.

[0082] Step 3: Based on the rocket's dynamic characteristics and maneuverability, limit the correction amount of the unloading program angle. The rocket's dynamic characteristics and maneuverability refer to the limitation of the rocket's angular acceleration.

[0083] The actual load reduction program angle is obtained by limiting the correction amount of the load reduction program angle, as follows:

[0084] (1) Calculate the pitch angle and load reduction angular velocity using the following formula. Yaw angle and load reduction angular velocity :

[0085]

[0086] in, The actual pitch angle for the (i-1)th step of the load reduction program. The actual pitch angle for the load reduction procedure in step i-2; The actual yaw angle for the (i-1)th step of the load reduction procedure. Δt is the actual yaw angle for the (i-2)th step of load reduction; Δt is the time interval between the two steps.

[0087] (2) Based on the dynamic characteristics and maneuverability of the rocket body, obtain the required value of the pitch attitude adjustment for the i-th step. The required yaw attitude adjustment value is δψ1. Calculate the i-th step unloading pitch angle after considering angular acceleration limiting. Step i: Load reduction and yaw procedure angle :

[0088]

[0089] in, Let the initial load reduction pitch angle be the ideal value for the i-th step. The pitch angle limit value is obtained based on the angular acceleration limit value. Let δψ be the ideal value of the initial yaw angle for the i-th step of the load reduction procedure. u The yaw angle limit is obtained based on the angular acceleration limit. when When the result is positive, take +1; when the result is negative, take -1.

[0090] (3) Calculate the difference between the pitch angle unloading angular velocity and the nominal angular velocity. The difference between the yaw angle unloading angular velocity and the nominal angular velocity :

[0091]

[0092] in, The nominal program angular velocity;

[0093] (4) Calculate the actual load reduction procedure angle in step i, considering the load reduction damping correction coefficient.

[0094]

[0095] Where, k damp This is the load reduction damping correction factor.

[0096] This invention takes into account various interferences, and the relationship between the qα value, rocket control capability, and Mach number is closer. Therefore, it is more reasonable to use Mach number rather than flight time as the independent variable for the qα limit and angular acceleration limit. Threshold triggering can avoid premature load reduction intervention, thereby improving the flexibility of load reduction while ensuring its effectiveness.

[0097] This invention also provides an adaptive passive wind load mitigation design system based on threshold triggering, comprising: an aerodynamic parameter calculation module, an initial load reduction program angle ideal value calculation module, and an actual load reduction program angle acquisition module. The aerodynamic parameter calculation module calculates the aerodynamic parameters without load reduction based on the nominal program angle; the initial load reduction program angle ideal value calculation module calculates the initial load reduction program angle ideal value when the flight Mach number is within the allowable load reduction range and the qα value exceeds the current limit value; the actual load reduction program angle acquisition module limits the load reduction program angle correction based on the rocket's dynamic characteristics and maneuverability to obtain the actual load reduction program angle.

[0098] Example:

[0099] The application of this invention will be explained using a certain launch vehicle as an example.

[0100] Taking the pitch channel as an example for further processing, the yaw channel is the same.

[0101] Step 1: Calculate the aerodynamic parameters without load reduction based on the nominal program angle:

[0102] Δα f =α1-α0

[0103] Δα ph =α-α0

[0104] In the formula, Δα f This is the additional angle of attack caused by high-altitude winds. Δα ph To account for the angle of attack error caused by torque balance and guidance, α0 represents the ideal ground speed angle of attack caused by the rocket's velocity relative to the ground, α1 represents the ideal aerodynamic angle of attack caused by the rocket's velocity relative to the airflow, and α represents the aerodynamic angle of attack considering torque balance and guidance.

[0105] Step 2, calculate the ideal value of the initial unloading program angle:

[0106] The decision to reduce load is based on the Mach number. If the current load is within the Mach number range for load reduction, and the qα value is greater than the upper limit of qα, then load reduction is initiated. First, the load reduction coefficient k is calculated. relief as follows,

[0107]

[0108] Among them, Ma l Ma u Let (qα) be the lower and upper bounds of the Mach number range. u Let qα be the upper limit. Let the initial unloading procedure angle be the ideal value for the i-th step. The nominal pitch and roll angles are given at the current moment. Δθ represents the change in trajectory tilt caused by high-altitude winds. Δβ fΔβ is the additional sideslip angle caused by high-altitude winds. ph To account for the sideslip angle error in aerodynamic balance and guidance.

[0109] Step 3: Based on the rocket's dynamic characteristics and maneuverability, limit the magnitude of the load reduction program angle correction.

[0110] Define unloading angular velocity as follows,

[0111]

[0112] in, For the (i-1)th step of the actual load reduction procedure, Δt is the actual load reduction procedure angle in step i-2; Δt is the time interval between the two steps.

[0113] Based on the dynamic characteristics of the rocket body, calculate the required value of the attitude adjustment in the i-th step. The i-th step of the load reduction procedure, considering angular acceleration limiting, is obtained. :

[0114]

[0115] in, Indicates according to The positive and negative values ​​are respectively taken as positive and negative 1. The angle limit value is obtained based on the angular acceleration limit value.

[0116] definition The difference between the unloaded angular velocity and the nominal angular velocity.

[0117]

[0118] in, This is the nominal program angular velocity.

[0119] Finally, the i-th step of the load reduction procedure angle is obtained after considering the load reduction damping correction factor.

[0120]

[0121] Where, k damp This is the load reduction damping correction factor.

[0122] Figure 2 A comparison of the load reduction effects of applying this embodiment with traditional load reduction methods is presented.

[0123] In this example, the maximum qα value of the six-degree-of-freedom target hit in the transonic band using the threshold-triggered adaptive passive wind load mitigation design method proposed in this invention is reduced by 16.6% compared with the traditional design method.

[0124] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A threshold-triggered adaptive passive wind load mitigation design method, characterized in that, include: Calculate the aerodynamic parameters without load reduction based on the nominal program angle; When the flight Mach number is within the allowable load reduction range and the qα value exceeds the current limit, load reduction is performed, and the ideal value of the initial load reduction program angle is calculated; q is the dynamic pressure, and α is the aerodynamic angle of attack considering torque balance and guidance; By combining the dynamic characteristics and maneuverability of the rocket body, the correction amount of the load reduction program angle is limited to obtain the actual load reduction program angle.

2. The adaptive passive wind load mitigation design method based on threshold triggering according to claim 1, characterized in that, The aerodynamic parameters without load reduction are calculated based on the nominal program angle, as follows: Da f =α1-α0 Da ph =α-α0 Db f =β1-β0 Db ph =β-β0 In the formula, Δα f Δα is the additional angle of attack caused by high-altitude winds. ph To account for aerodynamic balance and guidance angle-of-attack errors; α0 represents the ideal ground speed angle of attack generated by the rocket's velocity relative to the ground, α1 represents the ideal aerodynamic angle of attack generated by the rocket's velocity relative to the airflow, and α represents the aerodynamic angle of attack considering torque balance and guidance; Δβ f Δβ is the additional sideslip angle caused by high-altitude winds. ph To account for the sideslip angle error in aerodynamic balance and guidance; β0 represents the ideal ground speed sideslip angle generated by the rocket's velocity relative to the ground, β1 represents the ideal aerodynamic sideslip angle generated by the rocket's velocity relative to the airflow, and β represents the aerodynamic sideslip angle considering torque balance and guidance.

3. The adaptive passive wind load mitigation design method based on threshold triggering according to claim 1, characterized in that, The ideal value of the initial unloading program angle in step i is calculated using the following formula: These are the ideal values ​​of the pitch program angle and the yaw program angle for the initial load reduction in step i, respectively. and The nominal pitch, yaw, and roll angles at the current moment are given; Δθ and Δσ represent the changes in trajectory tilt and deviation caused by high-altitude winds, respectively; Δα f Δα is the additional angle of attack caused by high-altitude winds. ph To account for the angle of attack error in aerodynamic balance and guidance; Δβ f Δβ is the additional sideslip angle caused by high-altitude winds. ph To account for sideslip angle errors in aerodynamic balance and guidance; k relief This is the load reduction factor.

4. The adaptive passive wind load mitigation design method based on threshold triggering according to claim 3, characterized in that, Among them, Ma l and Ma u Let (qα) be the lower and upper bounds of the Mach number range. u Let qα be the upper limit value, and Ma be the Mach number at the current moment.

5. The adaptive passive wind load mitigation design method based on threshold triggering according to claim 1, characterized in that, The dynamic characteristics and maneuverability of the rocket body are characterized by the limiting of the rocket body's angular acceleration.

6. The adaptive passive wind load mitigation design method based on threshold triggering according to claim 1, characterized in that, The actual load reduction program angle is obtained by limiting the correction amount of the load reduction program angle, as follows: (1) Calculate the pitch angle and load reduction angular velocity using the following formula. Yaw angle and load reduction angular velocity in, The actual pitch angle for the (i-1)th step of the load reduction program. The actual pitch angle for the load reduction procedure in step i-2; The actual yaw angle for the (i-1)th step of the load reduction procedure. Δt is the actual yaw angle for the (i-2)th step of load reduction; Δt is the time interval between the two steps. (2) Based on the dynamic characteristics and maneuverability of the rocket body, obtain the required value of the pitch attitude adjustment for the i-th step. The required yaw attitude adjustment value is δψ1. Calculate the i-th step unloading pitch angle after considering angular acceleration limiting. Step i: Load reduction and yaw procedure angle in, Let the initial load reduction pitch angle be the ideal value for the i-th step. The pitch angle limit value is obtained based on the angular acceleration limit value. Let δψ be the ideal value of the initial yaw angle for the i-th step of the load reduction procedure. u The yaw angle limit is obtained based on the angular acceleration limit. when When the result is positive, take +1; when the result is negative, take -1. (3) Calculate the difference between the pitch angle unloading angular velocity and the nominal angular velocity. The difference between the yaw angle unloading angular velocity and the nominal angular velocity in, The nominal program angular velocity; (4) Calculate the actual load reduction procedure angle in step i, considering the load reduction damping correction coefficient. Where, k damp This is the load reduction damping correction factor.

7. A threshold-triggered adaptive passive wind load mitigation design system, characterized in that, include: Aerodynamic parameter calculation module, initial load reduction program angle ideal value calculation module, actual load reduction program angle acquisition module; Aerodynamic parameter calculation module: Calculates aerodynamic parameters without load reduction based on the nominal program angle. The aerodynamic parameters include the additional angle of attack caused by high-altitude wind, the qα value, and the aerodynamic angle error considering aerodynamic balance and guidance. q is the dynamic pressure, and α is the angle of attack considering torque balance and guidance. Initial load reduction program angle ideal value calculation module: When the flight Mach number is within the allowable load reduction range and the qα value exceeds the current limit value, load reduction is performed, and the initial load reduction program angle ideal value is calculated; Actual load reduction program angle acquisition module: Combining the dynamic characteristics and maneuverability of the rocket body, the load reduction program angle correction amount is limited to obtain the actual load reduction program angle.

8. The adaptive passive wind load mitigation design system based on threshold triggering according to claim 7, characterized in that, In the aerodynamic parameter calculation module, the aerodynamic parameters without load reduction are calculated based on the nominal program angle, as follows: Da f =α1-α0 Da ph =α-α0 Db f =β1-β0 Db ph =β-β0 In the formula, Δα f Δα is the additional angle of attack caused by high-altitude winds. ph To account for aerodynamic balance and guidance angle-of-attack errors; α0 represents the ideal ground speed angle of attack generated by the rocket's velocity relative to the ground, α1 represents the ideal aerodynamic angle of attack generated by the rocket's velocity relative to the airflow, and α represents the aerodynamic angle of attack considering torque balance and guidance; Δβ f Δβ is the additional sideslip angle caused by high-altitude winds. ph To account for the sideslip angle error in aerodynamic balance and guidance; β0 represents the ideal ground speed sideslip angle generated by the rocket's velocity relative to the ground, β1 represents the ideal aerodynamic sideslip angle generated by the rocket's velocity relative to the airflow, and β represents the aerodynamic sideslip angle considering torque balance and guidance.

9. The adaptive passive wind load mitigation design system based on threshold triggering according to claim 7, characterized in that, The initial load reduction program angle ideal value calculation module calculates the ideal value of the initial load reduction program angle in step i using the following formula: These are the ideal values ​​of the pitch program angle and the yaw program angle for the initial load reduction in step i, respectively. and The nominal pitch, yaw, and roll angles at the current moment are given; Δθ and Δσ represent the changes in trajectory tilt and deviation caused by high-altitude winds, respectively; Δα f Δα is the additional angle of attack caused by high-altitude winds. ph To account for the angle of attack error in aerodynamic balance and guidance; Δβ f Δβ is the additional sideslip angle caused by high-altitude winds. ph To account for sideslip angle errors in aerodynamic balance and guidance; k relief This is the load reduction factor.

10. The adaptive passive wind load mitigation design system based on threshold triggering according to claim 7, characterized in that, The actual implementation method of the load reduction program angle acquisition module is as follows: (1) Calculate the pitch angle and load reduction angular velocity using the following formula. Yaw angle and load reduction angular velocity in, The actual pitch angle for the (i-1)th step of the load reduction program. The actual pitch angle for the load reduction procedure in step i-2; The actual yaw angle for the (i-1)th step of the load reduction procedure. Δt is the actual yaw angle for the (i-2)th step of load reduction; Δt is the time interval between the two steps. (2) Based on the dynamic characteristics and maneuverability of the rocket body, obtain the required value of the pitch attitude adjustment for the i-th step. The required yaw attitude adjustment value is δψ1. Calculate the i-th step unloading pitch angle after considering angular acceleration limiting. Step i: Load reduction and yaw procedure angle in, Let the initial load reduction pitch angle be the ideal value for the i-th step. The pitch angle limit value is obtained based on the angular acceleration limit value. Let δψ be the ideal value of the initial yaw angle for the i-th step of the load reduction procedure. u The yaw angle limit is obtained based on the angular acceleration limit. when When the result is positive, take +1; when the result is negative, take -1. (3) Calculate the difference between the pitch angle unloading angular velocity and the nominal angular velocity. The difference between the yaw angle unloading angular velocity and the nominal angular velocity in, The nominal program angular velocity; (4) Calculate the actual load reduction procedure angle in step i, considering the load reduction damping correction coefficient. Where, k damp This is the load reduction damping correction factor.

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