Bird body electromagnetic emission analytical model correction method based on multivariable sensitivity iterative calculation

Abstract

The bird body electromagnetic emission analytical model correction method based on multivariable sensitivity iterative calculation comprises the following steps: setting structural parameters, electrical parameters and iterative initial parameters of a multistage electromagnetic coil bird body emission device, and selecting key parameters for model correction from the structural parameters, the electrical parameters and the iterative initial parameters; according to the structure parameters and the electrical parameters, establishing a bird body electromagnetic emission theory analysis model under the driving of the multi-stage coil; carrying out iterative calculation and solving by adopting a forward difference method based on the analytical model to obtain bird body launching performance after the cartridge case armature is out of the bore, including launching acceleration, speed and displacement; performing Sobol parameter sensitivity analysis according to the selected key parameters to obtain a sensitivity sequence of the key parameters; setting an iteration step length of each key parameter, and performing multi-level analytical model correction according to a sensitivity sequence of the key parameters until a set final correction target is met; and outputting the structure parameters and the electrical parameters after the theoretical analysis model is corrected.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electromagnetic emission, and relates to a bird body electromagnetic emission analytical model correction method based on multivariate sensitivity iterative calculation. BACKGROUND

[0002] In recent years, with the continuous pursuit of high thrust-to-weight ratio by high-performance aero-engines, it has become an inevitable trend to replace traditional metal blades with lightweight composite materials with low density and high performance. However, when a bird strike occurs, composite blades face more challenges compared to metal blades. Because the interlaminar strength of composite blades is low, and their ductility and energy absorption capacity are not as good as metal materials, they are more vulnerable when facing the impact load generated by bird strikes. The internal delamination damage after the collision can threaten the overall structural integrity of the blade. Therefore, it is particularly important to conduct bird strike test research on advanced composite fan blades.

[0003] Currently, multi-stage electromagnetic coil bird body emission technology is developing rapidly, and it has the outstanding advantages of controllable emission speed, high emission speed, small occupied space, high energy conversion efficiency, etc. In order to save test costs and reduce unnecessary material waste, before the bird body emission test, it is necessary to carry out prediction analysis on the electromagnetic emission performance of the bird body or projectile to provide material selection data for blade bird strike tests, etc. However, the existing model usually has a large prediction error for the bird body emission speed and other parameters, so it is necessary to study the correction of the bird body electromagnetic emission model, which has important engineering needs and academic value.

[0004] At present, there are many literatures reporting the prediction and analysis methods of the performance parameters of electromagnetic coil launching devices, but none of them corrects the prediction model. Chinese patent application CN116306071A uses the analysis method of combining finite elements with equivalent circuits, divides the track into finite elements, sets the armature at the tail of each element, and iteratively calculates to obtain a more realistic launching process of the electromagnetic railgun. However, using displacement as a variable is not conducive to obtaining the trend of key parameters changing with time, which is not conducive to accurately predicting the final launching speed and acceleration of the projectile and other parameters, and the model is not corrected and analyzed. Chinese patents CN113049205A, CN117554017A, etc. all develop parameter calculation of bird impact test devices based on electromagnetic launching technology, but only single-stage electromagnetic launching is considered, without considering the high acceleration generated by multi-stage electromagnetic coils and its impact on the bird body, and the model is not corrected and analyzed. Chinese patent application CN119761143A proposes a design method based on predetermined launching performance, which uses a multi-objective genetic algorithm to inversely calculate the parameter indicators of multi-stage electromagnetic coil launchers that meet the performance, but does not correct and analyze the established calculation model. Chinese patent CN112069703A proposes a prediction and optimization design method for electromagnetic coil launching systems, which constructs an electromagnetic coil parameter optimization model and uses an intelligent optimization algorithm to obtain optimized electromagnetic coil parameters to improve the optimization efficiency of electromagnetic coil launching system parameters, but does not correct and analyze the established optimization model.

[0005] In addition, some scholars have corrected the prediction model of electromagnetic rail launching devices in their published papers, but almost no papers have corrected the prediction model of electromagnetic coil launching devices. For example, the papers "Experimental Study on the Spatiotemporal Distribution of Rail Temperature in Electromagnetic Launching" and "Research on the Temperature of Electromagnetic Rail Launching Device Based on Gray Model" discuss the spatiotemporal distribution of rail temperature in electromagnetic rail launching devices and correct the rail temperature field simulation model accordingly. The paper "Analysis of Electromagnetic Launch Projectile Muzzle Magnetic Field Distribution Characteristics" converts the arc root velocity of the electromagnetic rail launching device into a muzzle magnetic field velocity correction term to obtain a muzzle magnetic field simulation model considering the arc motion. The paper "Mathematical Model Construction of Rail under Step Load in Electromagnetic Launching" studies the mathematical model and control equation of the rail under step load and analyzes the motion differential equation of the beam, proving the influence of shear correction coefficient on the beam. It is emphasized that the above papers all correct the model for electromagnetic rail launching devices. SUMMARY

[0006] To address the aforementioned technical problems, the present invention aims to provide a method for correcting the analytical model of bird electromagnetic emission based on multivariate sensitivity iterative calculation. After establishing a prediction model for a multi-stage electromagnetic coil bird emission device, the method performs Sobol parameter sensitivity analysis on key parameters and corrects the model at multiple levels based on multivariate sensitivity iterative calculation technology, thereby further improving the prediction accuracy of the prediction model.

[0007] This invention provides a method for correcting an analytical model of bird electromagnetic emission based on multivariate sensitivity iterative calculation, comprising:

[0008] Step 1: Set the structural parameters, electrical parameters, and initial iteration parameters of the multi-stage electromagnetic coil bird launcher, and select the key parameters for model correction.

[0009] Step 2: Based on the structural and electrical parameters, establish a theoretical analytical model of the electromagnetic emission of a bird driven by a multi-stage coil.

[0010] Step 3: Based on the analytical model, iterative calculations and solutions are performed using the forward difference method to obtain the bird's launch performance after the cartridge armature leaves the barrel, including launch acceleration, velocity, and displacement.

[0011] Step 4: Perform Sobol parameter sensitivity analysis based on the key parameters selected in Step 1 to obtain the sensitivity order of the key parameters;

[0012] Step 5: Set the iteration step size for each key parameter, and perform multi-level analytical model correction according to the sensitivity order of the key parameters until the set final correction target is met.

[0013] Step 6: Output the corrected structural and electrical parameters of the theoretical analytical model.

[0014] A method for correcting the analytical model of bird electromagnetic emission based on multivariate sensitivity iterative calculation is proposed. After establishing a prediction model for a bird emission device with multi-stage electromagnetic coils, the method performs Sobol parameter sensitivity analysis on key parameters and corrects the model at multiple levels based on the sensitivity order, thereby improving the prediction accuracy of the prediction model. This method is suitable for high-precision prediction of the emission performance of bird emission devices with multi-stage electromagnetic coils and has high engineering application value. Attached Figure Description

[0015] Figure 1 This is a flowchart of a method for correcting an analytical model of bird electromagnetic emission based on multivariate sensitivity iterative calculation, according to the present invention.

[0016] Figure 2 The equivalent circuit model for any one stage coil of the multi-stage electromagnetic coil bird launcher;

[0017] Figure 3 Comparison of projectile launch velocities calculated and tested without model correction;

[0018] Figure 4 A trend diagram of the first-order influence exponent distribution of key parameters affecting the transmission speed of a three-stage electromagnetic coil transmitter;

[0019] Figure 5 The trend chart of the total effect index distribution for key parameters. Detailed Implementation

[0020] like Figure 1 As shown, this invention provides a method for correcting an analytical model of bird electromagnetic emission based on multivariate sensitivity iterative calculation, comprising:

[0021] Step 1: Set the structural parameters, electrical parameters, and initial iteration parameters of the multi-stage electromagnetic coil bird launcher, and select key parameters for model correction, specifically:

[0022] Step 1.1: Set the electrical and structural parameters of the multi-stage electromagnetic coil bird-launching device; electrical parameters include: self-inductance L of the drive coil circuit. d Self-inductance L of the cartridge armature coil circuit p , drive coil circuit resistance R d Resistance R of the cartridge armature coil circuit p Discharge capacitor C of the drive coil circuit; discharge voltage U of the drive coil circuit. d Structural parameters include: drive coil loop radius r d The radius r of the armature coil of the cartridge case carrying the bird p Total mass of bird body and armature m p Number of driving coil stages n d The number of turns N in a single-stage drive coil, the length of the drive coil, and the spacing between adjacent drive coils.

[0023] Step 1.2: Divide the armature coil portion of the cartridge containing the bird into n equal parts using the current wire method. The self-inductance of the armature coil circuit in the j-th part is L. pj The resistance of the armature coil circuit of the j-th cartridge case is R. pj The mutual inductance between the armature coil and the drive coil of the j-th cartridge case is M. dpj j = 1, 2, ..., n.

[0024] Step 1.3: Set the total prediction time T and the time step Δt, and the number of iterations is i = T / Δt.

[0025] Step 1.4: Set the initial drive coil current I at t=0. d Cartridge armature coil current I pThe electromagnetic force F on the armature of the cartridge case carrying the bird, the displacement s, velocity v, and acceleration a of the armature of the cartridge case carrying the bird are all 0.

[0026] Step 1.5: Select N key parameters from the parameters set in Step 1.1 for use in the subsequent steps to correct the analytical model.

[0027] Step 2: Based on the structural and electrical parameters, establish a theoretical analytical model for the electromagnetic emission of a bird driven by a multi-stage coil, specifically as follows:

[0028] Step 2.1: Based on the structural and electrical parameters, establish a theoretical analytical model for the electromagnetic launch of a bird under multi-stage coil drive. This predictive model includes an equivalent circuit model of the drive coil and an equivalent circuit model of the armature coil of the cartridge case carrying the bird.

[0029] The equivalent circuit model of the driving coil includes: a driving coil discharge switch, a driving coil energy storage capacitor, a driving coil circuit resistance, a driving coil circuit self-inductance, and a diode; the driving coil circuit self-inductance and driving coil circuit resistance are connected in series and then in parallel with the diode, and then connected in series with the driving coil discharge switch and the driving coil energy storage capacitor to form a closed circuit; the driving coil circuit resistance includes: capacitor resistance, discharge switch resistance, line resistance, and driving coil resistance; the driving coil circuit self-inductance includes: capacitor self-inductance, discharge switch self-inductance, line self-inductance, and driving coil self-inductance.

[0030] The equivalent circuit model of the cartridge armature coil of the bird-loaded carcass includes n equivalent circuits of the cartridge armature coil. Each cartridge armature coil circuit is a closed loop formed by the resistance of each cartridge armature coil and the self-inductance of each cartridge armature circuit connected in series. The resistance of each cartridge armature coil includes the line resistance and the resistance of each cartridge armature coil. The self-inductance of each cartridge armature circuit includes the line resistance and the self-inductance of each cartridge armature coil.

[0031] When the drive coil discharge switch is closed, the drive coil energy storage capacitor begins to discharge, the drive coil circuit generates current, and then generates an induced magnetic field. The induced magnetic field causes each cartridge armature coil circuit to generate an induced current. The induced current is subjected to electromagnetic force in the induced magnetic field, causing the cartridge armature to move and be launched.

[0032] Step 2.2: Ensure that the damping coefficient of the drive coil circuit is in an overdamped state:

[0033]

[0034] in, This is the damping coefficient of the drive coil circuit.

[0035] Step 3: Based on the analytical model, iterative calculations are performed using the forward difference method to obtain the launch performance of the bird after the cartridge case armature leaves the barrel, including launch acceleration, velocity, and displacement, specifically:

[0036] Step 3.1: According to Kirchhoff's equivalent circuit theory, for any stage of the drive coil and the cartridge armature coil of a multi-stage electromagnetic coil bird launcher, its equivalent circuit equation can be expressed as:

[0037]

[0038]

[0039] Among them, I d (t) represents the driving coil current at time t, I pj (t) represents the j-th current in the cartridge armature coil at time t.

[0040] Step 3.2: Solve for the electromagnetic force on the cartridge armature using the inductance method. At time t, the total magnetic field energy between the drive coil and the cartridge armature is expressed as:

[0041]

[0042] Then, the electromagnetic force acting on the cartridge armature along the x-direction at time t is:

[0043]

[0044] Step 3.3: Calculate the acceleration a(t) of the armature of the cartridge case carrying the bird at time t based on the electromagnetic force obtained in Step 3.2:

[0045]

[0046] Step 3.4: Calculate the velocity v(t) of the cartridge armature carrying the bird at time t based on the acceleration obtained in Step 3.3:

[0047]

[0048] Step 3.5: Calculate the displacement s(t) of the cartridge armature carrying the bird at time t based on the velocity obtained in Step 3.4:

[0049]

[0050] Step 3.6: Repeat steps 3.1-3.5 until all drive coil stages have been iterated to obtain the final muzzle acceleration, velocity, and displacement of the cartridge armature carrying the bird.

[0051] Step 4: Perform Sobol parameter sensitivity analysis based on the key parameters selected in Step 1 to obtain the sensitivity order of the key parameters, specifically as follows:

[0052] Step 4.1: Based on the N key parameters selected in Step 1.5, define X = (X1, X2, ..., X...). N () is a vector consisting of N key parameters; each key parameter is set One sample.

[0053] Step 4.2: Use the sobolset function to generate low-dissimilarity sequences, thus obtaining two... Given two base sample matrices A and B, replace the i-th column of matrix A with the i-th column of matrix B to generate a perturbation matrix C. i .

[0054] Step 4.3: Combine sample matrices A, B, and C. i Substituting the theoretical analytical model and using the forward difference method for iterative calculation, we obtain the γ-dimensional output variable vector Y. A Y B and The output variable is a certain launch performance, namely acceleration, velocity or displacement.

[0055] Step 4.4: Calculate the first-order influence index S of the i-th key parameter according to the following formula. i Total effect index

[0056]

[0057]

[0058] in,

[0059]

[0060]

[0061]

[0062] Where Var is the variance operator and E is the mean operator. For the i-th key parameter, , and The output variable vector Y is respectively A Y B , The j-th element in.

[0063] Step 4.5: Based on the first-order influence index S of each key parameter obtained in Step 4.4 i Total effect index The sensitivity of key parameters is ranked, and the higher the first-order influence index, the stronger the sensitivity of the key parameter.

[0064] Step 5: Set the iteration step size for each key parameter, and perform multi-level analytical model correction according to the sensitivity order of the key parameters until the set final correction target is met. Specifically:

[0065] Step 5.1: Set the iteration step size, maximum number of iterations, and corresponding correction target for the emission performance error of each key parameter;

[0066] Step 5.2: Select the key parameters corresponding to the current level according to the sensitivity order of the key parameters;

[0067] Step 5.3: Following the direction of reducing the launch performance error as the direction of iterative adjustment, adjust the corresponding key parameters according to the iteration step size to obtain the adjusted theoretical analytical model;

[0068] Step 5.4: Based on the adjusted theoretical analytical model, the forward difference method is used to solve the problem, obtain the bird's launch performance, and calculate the error of the launch performance;

[0069] Step 5.5: Determine whether the error in the transmission performance meets the correction target for the transmission performance error at this level. If not, return to step 5.3 to continue iterating until the correction target for the current level is met or the maximum number of iterations is reached.

[0070] Step 5.6: If the correction objective of the current level is met, return to Step 5.2 to select the key parameters of the next level until the final correction objective is met, specifically:

[0071] Step 5.6.1: If the correction objective of the current level is met, return to step 5.2 to select the key parameters of the next level;

[0072] Step 5.6.2: Determine whether the error of the transmission performance of the theoretical analytical model after the current layer adjustment meets the correction target of the transmission performance error of the next layer. If it does, do not perform the correction of the next layer, and continue the correction process of the subsequent layers until the final correction target is met.

[0073] Step 6: Output the corrected structural and electrical parameters of the theoretical analytical model.

[0074] Example

[0075] The equivalent circuit model corresponding to any one level coil of the multi-level electromagnetic coil bird launching device created in this embodiment is as follows: Figure 2 As shown. The radius r of each stage of the drive coil in the constructed bird electromagnetic emission experimental test system is... dIt measures 62 mm in diameter, 70 mm in length, and has a stage spacing of 10 mm. The projectile consists of a cylindrical aluminum alloy-nylon cartridge case and a cylindrical gelatinous body, with a radius r. p It measures 60 mm in diameter, 200 mm in length, and has a total mass of 3070 g.

[0076] Based on the established bird electromagnetic emission experimental test system, two three-stage coil emission tests were conducted under the same operating conditions. During the tests, the discharge capacitor C was 0.6 mF, and the discharge voltage U... d The voltage is 5600V, and the resistance R of the drive coil circuit is... d The Ω value is 0.01 Ω. The high-speed camera acquisition system collects the flight distance and frame rate difference corresponding to the projectile's flight distance at 1 / 3 of its length, 2 / 3 of its length, and its overall length when it exits the firing barrel. The firing velocity under the corresponding conditions is then calculated based on the known frame rate of the high-speed camera. A comparison of the calculated and experimental firing velocities of the projectile's armature under two identical conditions, without model correction, is shown below. Figure 3 As shown.

[0077] Select discharge voltage U d (V), discharge capacitor C (mF), drive coil inductance L d (H) Drive coil resistance R d Six key parameters—Ω, initial launch position s1 (mm), and the number of turns N of the single-stage drive coil—were used as design variables to analyze their sensitivity to the projectile's launch velocity. Simultaneously, considering practical engineering applications, U... d C, L d R d The upper and lower limits of s1 and N are set as (5040, 6160), (0.54, 0.66), (0.00054, 0.00066), (1.28, 1.56), (0.036, 0.044), and (530, 600), respectively, and 1000 samples are selected for each set of parameters.

[0078] Figure 4 and Figure 5 A sensitivity ranking diagram of key parameters affecting the launch velocity of a projectile in a three-stage electromagnetic coil launcher is presented. Analysis shows that the number of turns N in the single-stage drive coil and the discharge capacitance C are the core parameters affecting the launch performance of the electromagnetic coil. Among them, the influence of N is the most significant, followed by C, while the influence of other parameters is weak. Furthermore, since the distribution trend of the total effect exponent is basically consistent with the first-order influence exponent, the interaction effect of the above parameters is not significant.

[0079] Based on the sensitivity analysis results, a multi-level model correction study was conducted. The first level of correction used the first sensitive parameter (number of turns N in a single-stage coil) as the correction object, and the tested projectile launch velocity as the benchmark, to perform iterative correction calculations of the model. Table 1 shows the calculation errors of the number of turns in the single-stage coil and the projectile launch velocity under different correction cycles during the first level of model correction. When the 7th correction was performed, the launch velocity calculation error reached 2.66%, which met the error requirements of the first level of correction. The second level of correction used the second sensitive parameter (discharge capacitor C) as the correction object, and the tested projectile launch velocity as the benchmark, to perform iterative correction calculations of the model. Table 2 shows the calculation errors of the discharge capacitor and the projectile launch velocity under different correction cycles during the first level of model correction. When the 4th correction was performed, the launch velocity calculation error reached 0.67%, which is less than 1%, meeting the final correction error requirements, and the model has achieved good calculation accuracy.

[0080] Table 1

[0081]

[0082] Table 2

[0083]

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the ideas of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for correcting the analytical model of bird electromagnetic emission based on multivariate sensitivity iterative calculation, characterized in that, include: Step 1: Set the structural parameters, electrical parameters, and initial iteration parameters of the multi-stage electromagnetic coil bird launcher, and select the key parameters for model correction. Step 2: Based on the structural and electrical parameters, establish a theoretical analytical model of the electromagnetic emission of a bird driven by a multi-stage coil. Step 3: Based on the analytical model, iterative calculations and solutions are performed using the forward difference method to obtain the bird's launch performance after the cartridge armature leaves the barrel, including launch acceleration, velocity, and displacement. Step 4: Perform Sobol parameter sensitivity analysis based on the key parameters selected in Step 1 to obtain the sensitivity order of the key parameters; Step 5: Set the iteration step size for each key parameter, and perform multi-level analytical model correction according to the sensitivity order of the key parameters until the set final correction target is met. Step 6: Output the corrected structural and electrical parameters of the theoretical analytical model.

2. The method for correcting the analytical model of bird electromagnetic emission based on multivariate sensitivity iterative calculation according to claim 1, characterized in that, Step 1 specifically involves: Step 1.1: Set the electrical and structural parameters of the multi-stage electromagnetic coil bird-launching device; electrical parameters include: self-inductance L of the drive coil circuit. d Self-inductance L of the cartridge armature coil circuit p , drive coil circuit resistance R d Resistance R of the cartridge armature coil circuit p Discharge capacitor C of the drive coil circuit; discharge voltage U of the drive coil circuit. d Structural parameters include: drive coil loop radius r d The radius r of the armature coil of the cartridge case carrying the bird p Total mass of bird body and armature m p Number of driving coil stages n d The number of turns N in a single-stage drive coil, the length of the drive coil, and the spacing between two adjacent drive coil stages; Step 1.2: Divide the armature coil portion of the cartridge containing the bird into n equal parts using the current wire method. The self-inductance of the armature coil circuit in the j-th part is L. pj The resistance of the armature coil circuit of the j-th cartridge case is R. pj The mutual inductance between the armature coil and the drive coil of the j-th cartridge case is M. dpj j = 1, 2, ..., n; Step 1.3: Set the total prediction time T and the time step Δt, and the number of iterations is i = T / Δt; Step 1.4: Set the initial drive coil current I at t=0. d Cartridge armature coil current I p The electromagnetic force F on the armature of the cartridge case carrying the bird, the displacement s of the armature of the cartridge case carrying the bird, the velocity v, and the acceleration a are all 0 values. Step 1.5: Select N key parameters from the parameters set in Step 1.1 for use in the subsequent steps to correct the analytical model.

3. The method for correcting the analytical model of bird electromagnetic emission based on multivariate sensitivity iterative calculation according to claim 1, characterized in that, Step 2 specifically involves: Step 2.1: Based on the structural and electrical parameters, establish a theoretical analytical model for the electromagnetic launch of a bird under multi-stage coil drive. This predictive model includes an equivalent circuit model of the drive coil and an equivalent circuit model of the armature coil of the cartridge case carrying the bird. When the drive coil discharge switch is closed, the drive coil energy storage capacitor begins to discharge, the drive coil circuit generates current, and then generates an induced magnetic field. The induced magnetic field causes each cartridge armature coil circuit to generate an induced current. The induced current is subjected to electromagnetic force in the induced magnetic field, causing the cartridge armature to move and be launched. Step 2.2: Ensure that the damping coefficient of the drive coil circuit is in an overdamped state: in, This is the damping coefficient of the drive coil circuit.

4. The method for correcting the analytical model of bird electromagnetic emission based on multivariate sensitivity iterative calculation according to claim 1, characterized in that, Step 3 specifically involves: Step 3.1: According to Kirchhoff's equivalent circuit theory, for any stage of the drive coil and the cartridge armature coil of a multi-stage electromagnetic coil bird launcher, its equivalent circuit equation can be expressed as: Among them, I d (t) represents the driving coil current at time t, I pj (t) represents the j-th current in the cartridge armature coil at time t; Step 3.2: Solve for the electromagnetic force on the cartridge armature using the inductance method. At time t, the total magnetic field energy between the drive coil and the cartridge armature is expressed as: Then, the electromagnetic force acting on the cartridge armature along the x-direction at time t is: Step 3.3: Calculate the acceleration a(t) of the armature of the cartridge case carrying the bird at time t based on the electromagnetic force obtained in Step 3.2: Step 3.4: Calculate the velocity v(t) of the cartridge armature carrying the bird at time t based on the acceleration obtained in Step 3.3: Step 3.5: Calculate the displacement s(t) of the cartridge armature carrying the bird at time t based on the velocity obtained in Step 3.4: Step 3.6: Repeat steps 3.1-3.5 until all drive coil stages have been iterated to obtain the final muzzle acceleration, velocity, and displacement of the cartridge armature carrying the bird.

5. The method for correcting the analytical model of bird electromagnetic emission based on multivariate sensitivity iterative calculation according to claim 1, characterized in that, Step 4 specifically involves: Step 4.1: Based on the N key parameters selected in Step 1.5, define X = (X1, X2, ..., X...). N () is a vector consisting of N key parameters; each key parameter is set One sample; Step 4.2: Use the sobolset function to generate low-dissimilarity sequences, thus obtaining two... Given two base sample matrices A and B, replace the i-th column of matrix A with the i-th column of matrix B to generate a perturbation matrix C. i ; Step 4.3: Combine sample matrices A, B, and C. i Substituting the theoretical analytical model and using the forward difference method for iterative calculation, we obtain the γ-dimensional output variable vector Y. A Y B and The output variable is a certain launch performance, namely acceleration, velocity or displacement; Step 4.4: Calculate the first-order influence index S of the i-th key parameter according to the following formula. i Total effect index : in, Where Var is the variance operator and E is the mean operator. For the i-th key parameter, , and The output variable vector Y is respectively A Y B , The j-th element in; Step 4.5: Based on the first-order influence index S of each key parameter obtained in Step 4.4 i Total effect index The sensitivity of key parameters is ranked, and the higher the first-order influence index, the stronger the sensitivity of the key parameter.

6. The method for correcting the analytical model of bird electromagnetic emission based on multivariate sensitivity iterative calculation according to claim 1, characterized in that, Step 5 specifically involves: Step 5.1: Set the iteration step size, maximum number of iterations, and corresponding correction target for the emission performance error of each key parameter; Step 5.2: Select the key parameters corresponding to the current level according to the sensitivity order of the key parameters; Step 5.3: Following the direction of reducing the launch performance error as the direction of iterative adjustment, adjust the corresponding key parameters according to the iteration step size to obtain the adjusted theoretical analytical model; Step 5.4: Based on the adjusted theoretical analytical model, the forward difference method is used to solve the problem, obtain the bird's launch performance, and calculate the error of the launch performance; Step 5.5: Determine whether the error in the transmission performance meets the correction target for the transmission performance error at this level. If not, return to step 5.3 to continue iterating until the correction target for the current level is met or the maximum number of iterations is reached. Step 5.6: If the correction target of the current level is met, return to step 5.2 to select the key parameters of the next level until the final correction target is met.

7. The method for correcting the analytical model of bird electromagnetic emission based on multivariate sensitivity iterative calculation according to claim 6, characterized in that, Step 5.6 specifically involves: Step 5.6.1: If the correction objective of the current level is met, return to step 5.2 to select the key parameters of the next level; Step 5.6.2: Determine whether the error of the transmission performance of the theoretical analytical model after the current layer adjustment meets the correction target of the transmission performance error of the next layer. If it does, do not perform the correction of the next layer, and continue the correction process of the subsequent layers until the final correction target is met.

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