Three-dimensional intersection vector constraint guidance method under initial large miss angle

Abstract

The application discloses a three-dimensional intersection vector constraint guidance method under an initial large misalignment angle, wherein a three-dimensional relative reference frame fixed with a target mass center is introduced, and a quaternion multiplication is used to restate the intersection vector constraint in the reference frame, so that a terminal constraint and a limited time constraint horizontal acceleration instruction is obtained, and the aircraft hits the target based on the instruction; since the guidance method has an accurate nonlinear property, the tolerable initial misalignment angle can be obviously higher than that of an existing linearization guidance method; the method can accurately control the terminal intersection vector of the aircraft under the large misalignment angle, and avoids the task failure caused by the instruction divergence of the commonly used linearization guidance method.

Description

Technical Field

[0001] This invention relates to the field of aircraft guidance technology, specifically to a three-dimensional intersection vector constraint guidance method under initial large misalignment angle conditions. Background Technology

[0002] Nonlinear dynamic systems of aircraft motion are difficult to solve analytically. Existing methods linearize the model under small angular errors and ignore the coupling effect of the transverse and longitudinal channels, decomposing the guidance problem into two planar interception problems for solution. However, for three-dimensional interception problems with large misalignment angles, the small-angle assumption is difficult to satisfy, and the performance of the linear guidance law deteriorates sharply.

[0003] Based on this, the inventors conducted in-depth research on the problem of intercepting maneuvering targets. By introducing a three-dimensional spatial reference frame and utilizing optimal control theory, an optimal three-dimensional intersection vector constraint guidance method was designed under the premise of a large initial misalignment angle without any linearization assumptions. Summary of the Invention

[0004] To overcome the aforementioned problems, the inventors conducted in-depth research and designed a three-dimensional convergence vector constraint guidance method under a large initial misalignment angle. This method introduces a three-dimensional relative reference frame fixed to the target's center of mass. Quaternion multiplication is used to redefine the convergence vector constraint in the reference coordinate system, thereby obtaining lateral acceleration commands for terminal and finite-time constraints. Based on these commands, the aircraft is controlled to hit the target. Because this guidance method possesses precise nonlinear properties, its tolerable initial misalignment angle is significantly higher than that of existing linearized guidance methods. This method can accurately control the terminal convergence vector of the aircraft under large misalignment angles, avoiding mission failure caused by command divergence in commonly used linearized guidance methods, thus completing this invention.

[0005] Specifically, the purpose of this invention is to provide a three-dimensional intersection vector constraint guidance method under an initial large misalignment angle, wherein:

[0006] The aircraft with an initial large misalignment angle generates a lateral acceleration command in real time based on the acquired self-information and target information. This lateral acceleration command is used to control the servo motors to perform rudder maneuvers in real time. The rudder maneuvers generate aerodynamic forces, which change the aircraft's trajectory and ultimately control the aircraft to hit the target.

[0007] The lateral acceleration command is obtained through the following formula (a):

[0008]

[0009] Among them, a M This indicates a lateral acceleration command;

[0010] e VA unit vector representing the relative velocity between the aircraft and the target;

[0011] e M Indicates the direction of the aircraft's velocity vector;

[0012] a n Indicates perpendicular to e V normal acceleration;

[0013] a T This represents the target's acceleration vector.

[0014] Wherein, perpendicular to e V normal acceleration a n We obtain it through the following formula (ii):

[0015]

[0016]

[0017] Where N and M independently represent guidance gain coefficients;

[0018] Ω L Represents the line-of-sight angular rate vector;

[0019] r represents the relative distance between the aircraft and the target;

[0020] The derivative of r;

[0021] V R This indicates the magnitude of the relative velocity between the aircraft and the target;

[0022] ζ represents the angle between the guidance plane and the plane containing the desired intersection vector;

[0023] δ represents the velocity misalignment angle;

[0024] ε represents the angle between the predicted intersection direction and the desired intersection direction;

[0025] e y e V The normal vector of the unit vector in the guidance plane;

[0026] e z e y and e V The unit normal vector of the determined guidance plane.

[0027] Wherein, the line-of-sight angular rate vector Ω L We obtain it through the following formula (iii):

[0028]

[0029] Among them, e L This indicates the direction of the line-of-sight vector between the aircraft and the target.

[0030] Among them, ζ is obtained through the following equation (iv):

[0031] ζ=arcsin[(e z ·e d (iv)

[0032] Among them, e d This indicates the desired direction of the intersection vector.

[0033] The velocity misalignment angle δ is obtained through the following equation (V):

[0034] δ=arccos(e V ·e L ) (five)

[0035] Wherein, ε is obtained through the following equation (vi):

[0036]

[0037] Among them, e d Indicates the desired direction of the intersection vector;

[0038] This indicates the predicted direction of the three-dimensional intersection vector at the end of the path.

[0039] Among them, e d We obtain it through the following formula (VII):

[0040]

[0041] Where q represents a quaternion.

[0042] n represents the unit axis of rotation;

[0043] σ represents the rotation angle;

[0044] κ represents the velocity ratio between the aircraft and the target;

[0045] q * Describes the conjugate of the quaternion q;

[0046] e imp Represents a vector in an inertial coordinate system;

[0047] e T Indicates the direction of the target's velocity vector.

[0048] in, Obtained through the following formula (8):

[0049]

[0050] Where, q V Representing quaternions,

[0051] Representing the quaternion q V Conjugate;

[0052] γ V e V The rotation angle;

[0053] e z e y and e V The unit normal vector of the determined guidance plane.

[0054] The beneficial effects of this invention include:

[0055] (1) According to the three-dimensional intersection vector constraint guidance method under the initial large misalignment angle provided by the present invention, a three-dimensional relative reference coordinate system is introduced in the method, so that the original guidance problem can be solved without small angle linearization, thereby enabling accurate target hit even under the initial large misalignment angle.

[0056] (2) According to the three-dimensional intersection vector constraint guidance method under the initial large misalignment angle provided by the present invention, the energy consumption of the aircraft is reduced, the interception potential is greater, and the final interception rate is higher. Attached Figure Description

[0057] Figure 1 This document shows schematic diagrams of the motion trajectories of the aircraft and the target under four conditions: guidance gain coefficient N = 3, 4, M = 1, 2, as illustrated in Embodiment 1 of this application.

[0058] Figure 2 This application illustrates, in Embodiment 1, the lateral guidance command a in the inertial frame of the aircraft under four conditions: guidance gain coefficient N = 3, 4, M = 1, 2. M Schematic diagram showing changes over time;

[0059] Figure 3 This illustration shows the relative lead angle changing over time in four cases: guidance gain coefficient N = 3, 4, M = 1, 2, according to Embodiment 1 of this application.

[0060] Figure 4 This illustration shows the change of the predicted angle error at the terminal moment over time in four cases: guidance gain coefficient N = 3, 4, M = 1, 2, according to Embodiment 1 of this application.

[0061] Figure 5This illustration shows a schematic diagram of the four trajectories corresponding to the four initial yaw angles and the target trajectory during a rear-end collision interception in Embodiment 2 of this application.

[0062] Figure 6 This application illustrates, in Embodiment 2, the four lateral acceleration commands a corresponding to the four initial yaw angles during a rear-end collision interception. M A schematic diagram showing how the norm changes over time;

[0063] Figure 7 This diagram illustrates the change in total control consumption over time for the four aircraft corresponding to the four initial yaw angles during a tail-chase interception in Embodiment 2 of this application.

[0064] Figure 8 The diagram shows the four trajectories corresponding to the four initial yaw angles and the target trajectory in Comparative Example 1 of this application during a rear-end collision interception.

[0065] Figure 9 This application illustrates, in Comparative Example 1, the four lateral acceleration commands a corresponding to the four initial yaw angles during a rear-end collision interception. M A schematic diagram showing how the norm changes over time;

[0066] Figure 10 The diagram shows the total control consumption of the four aircraft corresponding to the four initial yaw angles as a function of time in Comparative Example 1 of this application during a tail-chase interception.

[0067] Figure 11 This illustration shows a schematic diagram of the four trajectories corresponding to the four initial yaw angles and the target trajectory during a frontal interception in Embodiment 3 of this application.

[0068] Figure 12 This application illustrates, in Embodiment 3, the four lateral acceleration commands a corresponding to the four initial yaw angles during a head-on interception. M A schematic diagram showing how the norm changes over time;

[0069] Figure 13 This diagram illustrates the change in total control consumption over time for the four aircraft corresponding to the four initial yaw angles during a head-on interception in Embodiment 3 of this application.

[0070] Figure 14 This application shows a schematic diagram of the four trajectories corresponding to the four initial yaw angles and the target trajectory during a head-on interception in Comparative Example 2.

[0071] Figure 15 This application illustrates, in Comparative Example 2, the four lateral acceleration commands a corresponding to the four initial yaw angles during a head-on interception. M A schematic diagram showing how the norm changes over time;

[0072] Figure 16The diagram illustrates the change in total control consumption over time for the four aircraft corresponding to the four initial yaw angles during a head-on interception, as shown in Comparative Example 2 of this application. Detailed Implementation

[0073] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Through these descriptions, the features and advantages of the present invention will become clearer and more apparent.

[0074] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0075] This invention provides a three-dimensional intersection vector constraint guidance method under initial large misalignment angle, wherein,

[0076] The aircraft with an initial large misalignment angle generates a lateral acceleration command in real time based on the acquired self-information and target information. This lateral acceleration command is used to control the servo motors to perform rudder maneuvers in real time. The rudder maneuvers generate aerodynamic forces, which change the aircraft's trajectory and ultimately control the aircraft to hit the target.

[0077] The large misalignment angle refers to a large angle between the velocity vector and the line-of-sight vector, generally greater than 60°.

[0078] Preferably, the lateral acceleration command is obtained by the following formula (a):

[0079]

[0080] Among them, a M This indicates a lateral acceleration command;

[0081] e V The unit vector representing the relative velocity between the aircraft and the target; obtained by the following formula:

[0082]

[0083] e T The direction of the target velocity vector is indicated, which is estimated by the ranging, angle measurement, and angular velocity measurement modules of the aircraft's electro-optical pod.

[0084] κ represents the velocity ratio between the aircraft and the target, i.e., κ = V T / V M <1;

[0085] V T The speed of the target is estimated by the ranging, angle measurement, and angular velocity modules of the aircraft's electro-optical pod.

[0086] V M The speed of the aircraft is indicated by its satellite positioning system or by estimation using accelerometer and gyroscope measurements.

[0087] e M Indicates the direction of the aircraft's velocity vector;

[0088] a n Indicates perpendicular to e V normal acceleration;

[0089] a T The acceleration vector of the target is estimated using information obtained from the ranging, angle measurement, and angular velocity measurement modules of the aircraft's electro-optical pod.

[0090] Preferably, perpendicular to e V normal acceleration a n We obtain it through the following formula (ii):

[0091]

[0092] Wherein, N and M independently represent guidance gain coefficients, and preferably take values ​​of N = 3, 4 and M = 1, 2;

[0093] Ω L Represents the line-of-sight angular rate vector;

[0094] The line-of-sight angular rate vector Ω L We obtain it through the following formula (iii):

[0095]

[0096] Among them, e L This indicates the direction of the line-of-sight vector between the aircraft and the target, which is obtained through the angle measurement module of the aircraft's electro-optical pod.

[0097] r represents the relative distance between the aircraft and the target, which is estimated by the ranging module of the aircraft's electro-optical pod;

[0098] This represents the derivative of r; it is estimated using the aircraft's electro-optical pod ranging module. Amplitude is V R The size of the projection in the direction of the line of sight.

[0099] V R The magnitude of the relative velocity between the aircraft and the target is obtained by the following formula:

[0100] V R =V M ||e M -κe T ||;

[0101] V M Indicates the speed of the aircraft;

[0102] ζ represents the angle between the guidance plane and the plane containing the desired intersection vector;

[0103] ζ is obtained through the following formula (iv):

[0104] ζ=arcsin[(e z ·e d (iv)

[0105] Among them, e d This indicates the desired direction of the intersection vector.

[0106] δ represents the velocity misalignment angle;

[0107] The velocity misalignment angle δ is obtained by the following equation (V):

[0108] δ=arccos(e V ·e L ) (five).

[0109] ε represents the angle between the predicted intersection direction and the desired intersection direction;

[0110] ε is obtained through the following equation (vi):

[0111]

[0112] Among them, e d This indicates the desired direction of the intersection vector.

[0113] e d We obtain it through the following formula (VII):

[0114]

[0115] Where q represents a quaternion.

[0116] n represents the unit axis of rotation, which is obtained by the following formula:

[0117]

[0118] σ represents the rotation angle, which is obtained by the following formula:

[0119]

[0120] t go Represents the remaining flight time; obtained using the following formula:

[0121] t go =tf -t;

[0122] t f The terminal convergence time is estimated by the aircraft's electro-optical pod ranging module.

[0123] t represents the current time, which is the time counted from when the aircraft took off.

[0124] q * Describes the conjugate of the quaternion q;

[0125] e imp The vector in the inertial coordinate system is obtained by the following formula:

[0126]

[0127] ψ T The yaw angle of the target is estimated by the ranging, angle measurement, and angular velocity measurement modules of the aircraft's electro-optical pod.

[0128] θ T The pitch angle of the target is estimated using information from the aircraft's electro-optical pods, including ranging, angle measurement, and angular velocity.

[0129] α represents e d Euler pitch angle;

[0130] β represents e d Euler yaw angle;

[0131] In this application, the operator " "Indicates Hamiltonian product."

[0132] Indicates the predicted direction of the three-dimensional intersection vector at the end;

[0133] Obtained through the following formula (8):

[0134]

[0135] q V Representing quaternions,

[0136] γ V e V The rotation angle; that is, around e z The angle of rotation is obtained by the following formula:

[0137]

[0138] Representing the quaternion q V . conjugate.

[0139] e y e V The normal vector of the unit vector in the guidance plane is obtained by the following formula:

[0140] e y =e z ×e V

[0141] e z e y and e V The unit normal vector of the determined guidance plane is obtained by the following formula:

[0142]

[0143] Example 1

[0144] The simulation environment is set as follows: the initial pitch angle of the aircraft is... The initial yaw angle of the aircraft is The target moves in its velocity coordinates with a constant vector a T =[0,0,4g] T When maneuvering, the intersection vector is β = 90° in the azimuth direction and α = 0° in the elevation direction.

[0145] Guidance gain coefficients N = 3, 4, M = 1, 2.

[0146] The three-dimensional intersection vector constraint guidance method under the initial large misalignment angle is used to guide and control the aircraft. The specific operation process is as follows:

[0147] The aircraft with an initial large misalignment angle generates a lateral acceleration command in real time based on the acquired self-information and target information. This lateral acceleration command is used to control the servo motors to perform rudder maneuvers in real time. The rudder maneuvers generate aerodynamic forces, which change the aircraft's trajectory and ultimately control the aircraft to hit the target.

[0148] The lateral acceleration command is obtained through the following formula (I):

[0149]

[0150] Among them, a M This indicates a lateral acceleration command;

[0151] e V A unit vector representing the relative velocity between the aircraft and the target;

[0152] e M Indicates the direction of the aircraft's velocity vector;

[0153] a n Indicates perpendicular to e V normal acceleration;

[0154] a T This represents the target's acceleration vector.

[0155] Perpendicular to e V normal acceleration a n We obtain it through the following formula (ii):

[0156]

[0157] Among them, Ω L Represents the line-of-sight angular rate vector;

[0158] The line-of-sight angular rate vector Ω L We obtain it through the following formula (iii):

[0159]

[0160] Among them, e L Indicates the direction of the line-of-sight vector between the aircraft and the target;

[0161] r represents the relative distance between the aircraft and the target;

[0162] The derivative of r;

[0163] V R This indicates the magnitude of the relative velocity between the aircraft and the target;

[0164] ζ represents the angle between the guidance plane and the plane containing the desired intersection vector;

[0165] ζ is obtained through the following formula (iv):

[0166] ζ=arcsin[(e z ·e d (iv)

[0167] δ represents the prediction angle error;

[0168] δ is obtained through the following formula (5):

[0169] δ=arccos(e V ·e L ) (five)

[0170] ε represents the relative velocity lead angle;

[0171] ε is obtained through the following equation (vi):

[0172]

[0173] Among them, e d Indicates the direction of the final flight path;

[0174] e d We obtain it through the following formula (VII):

[0175]

[0176] Where q represents a quaternion.

[0177] n represents the unit axis of rotation;

[0178] σ represents the rotation angle;

[0179] κ represents the velocity ratio between the aircraft and the target;

[0180] q * Describes the conjugate of the quaternion q;

[0181] e imp Represents a vector in an inertial coordinate system;

[0182] e T Indicates the direction of the target velocity vector.

[0183] Indicates the predicted direction of the three-dimensional intersection vector at the end;

[0184] Obtained through the following formula (8):

[0185]

[0186] Where, q V Representing quaternions,

[0187] Representing the quaternion q V Conjugate;

[0188] γ V e V The rotation angle;

[0189] e y e V The unit vector normal vector;

[0190] e z e y and e V The unit normal vector of the determined guidance plane.

[0191] Numerical simulation results are as follows Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown in the image.

[0192] in, Figure 1The diagram shows the motion trajectories of the aircraft and the target under four guidance gain coefficients: N = 3, 4, M = 1, 2.

[0193] Figure 2 This shows the lateral acceleration command a in the inertial frame of the aircraft under four conditions: guidance gain coefficients N = 3, 4, M = 1, 2. M A schematic diagram showing how the norm changes over time;

[0194] Figure 3 The diagram shows the relative velocity lead angle as a function of time under four guidance gain coefficients: N = 3, 4, M = 1, 2.

[0195] Figure 4 The diagram shows the change of prediction angle error over time for four cases: guidance gain coefficient N = 3, 4, M = 1, 2.

[0196] As can be seen from the results of Example 1, the three-dimensional intersection vector constraint guidance method under the initial large misalignment angle enables the aircraft to intercept maneuvering targets, and both δ and ε converge to zero; changing the guidance gain can shape the intercept trajectory and the profile of the guidance command of the aircraft.

[0197] Example 2

[0198] The simulation environment is set as follows: the initial pitch angle of the aircraft is... The initial yaw angle of the Target aircraft is (20° interval), that is There are four initial yaw angle scenarios: in the azimuth direction, the intersection vector is β = 0°, and in the elevation direction, the intersection vector is α = 0°, corresponding to the tail-end interception scenario.

[0199] The target moves in its velocity coordinates with a constant vector a T =[0,0,4g] T To carry out maneuvers.

[0200] The total control cost of the aircraft is evaluated using the following cost function:

[0201]

[0202] The guidance gain coefficients are N = 3 and M = 2.

[0203] The three-dimensional intersection vector constraint guidance method with an initial large misalignment angle, consistent with that in Example 1, is used to guide and control the aircraft.

[0204] Numerical simulation results are as follows Figures 5 to 7 As shown in the image.

[0205] in, Figure 5This diagram illustrates the four trajectories corresponding to four initial yaw angles and the target trajectory during a rear-end collision interception.

[0206] Figure 6 This shows the four lateral acceleration commands a corresponding to the four initial yaw angles during a rear-end collision interception. M A schematic diagram showing how the norm changes over time;

[0207] Figure 7 The diagram illustrates the change in total control consumption over time for four aircraft corresponding to four initial yaw angles during a tail-end interception.

[0208] Comparative Example 1

[0209] The simulation environment is set as follows: the initial pitch angle of the aircraft is... The initial yaw angle of the aircraft is (20° interval), that is There are four initial yaw angle scenarios: in the azimuth direction, the intersection vector is β = 0°, and in the elevation direction, the intersection vector is α = 0°, corresponding to the tail-end interception scenario.

[0210] The target moves in its velocity coordinates with a constant vector a T =[0,0,4g] T To carry out maneuvers.

[0211] The total control cost of the aircraft is evaluated using the following cost function:

[0212]

[0213] A three-dimensional ballistic shaping guidance law is used to guide and control the aircraft.

[0214] Specifically, the lateral acceleration command 'a' is obtained through the following formula: M :

[0215]

[0216] in, Indicates a T Perpendicular to e M The amount;

[0217] Guidance gain N σ and N f The following formula determines that m = 1:

[0218] N σ =(m+2)(m+3)

[0219] N f =(m+1)(m+2)

[0220] Final flight path direction ed Obtained through the following formula:

[0221]

[0222] Numerical simulation results are as follows Figures 8 to 10 As shown in the image.

[0223] in, Figure 8 This diagram illustrates the four trajectories corresponding to four initial yaw angles and the target trajectory during a rear-end collision interception.

[0224] Figure 9 This shows the four lateral acceleration commands a corresponding to the four initial yaw angles during a rear-end collision interception. M A schematic diagram showing how the norm changes over time;

[0225] Figure 10 The diagram illustrates the change in total control consumption over time for four aircraft corresponding to four initial yaw angles during a tail-end interception.

[0226] Comparing the results of Example 2 and Comparative Example 1, it can be seen that when the initial flight direction of the aircraft is close to the desired collision course, i.e. The control consumption in Comparative Example 1 is similar to that in Example 2. However, when the initial heading error is large, the control consumption in Comparative Example 1 is significantly higher than that in Example 2.

[0227] Example 3

[0228] The simulation environment is set as follows: the initial pitch angle of the aircraft is... The initial yaw angle of the aircraft is (20° interval), that is There are four initial yaw angle scenarios; in the azimuth direction, the intersection vector is β = 0°, and in the elevation direction, the intersection vector is α = 180°, corresponding to the frontal interception scenario.

[0229] The target moves in its velocity coordinates with a constant vector a T =[0,0,4g] T To carry out maneuvers.

[0230] The total control cost of the aircraft is evaluated using the following cost function:

[0231]

[0232] The guidance gain coefficients are N = 4 and M = 2.

[0233] The three-dimensional intersection vector constraint guidance method with an initial large misalignment angle, consistent with that in Example 1, is used to guide and control the aircraft.

[0234] Numerical simulation results are as follows Figures 11 to 13 As shown in the image.

[0235] in, Figure 11 This diagram illustrates the four trajectories corresponding to four initial yaw angles and the target trajectory during a head-on interception.

[0236] Figure 12 This shows the four lateral acceleration commands a corresponding to the four initial yaw angles during a head-on interception. M A schematic diagram showing how the norm changes over time;

[0237] Figure 13 The diagram illustrates the change in total control consumption over time for four aircraft corresponding to four initial yaw angles during a head-on interception.

[0238] Comparative Example 2

[0239] The simulation environment is set as follows: the initial pitch angle of the aircraft is... The initial yaw angle of the aircraft is (20° interval), that is There are four initial yaw angle scenarios; in the azimuth direction, the intersection vector is β = 0°, and in the elevation direction, the intersection vector is α = 180°, corresponding to the frontal interception scenario.

[0240] The target moves in its velocity coordinates with a constant vector a T =[0,0,4g] T To carry out maneuvers.

[0241] The total control cost of the aircraft is evaluated using the following cost function:

[0242]

[0243] A three-dimensional ballistic shaping guidance law is used to guide and control the aircraft.

[0244] Specifically, the lateral acceleration command 'a' is obtained through the following formula: M :

[0245]

[0246] in, Indicates a T Perpendicular to e M The amount;

[0247] Guidance gain N σ and N f The following formula determines that m = 1:

[0248] N σ =(m+2)(m+3)

[0249] Nf =(m+1)(m+2)

[0250] Final flight path direction e d Obtained through the following formula:

[0251]

[0252] Numerical simulation results are as follows Figures 14 to 16 As shown in the image.

[0253] in, Figure 14 This diagram illustrates the four trajectories corresponding to four initial yaw angles and the target trajectory during a head-on interception.

[0254] Figure 15 This shows the four lateral acceleration commands a corresponding to the four initial yaw angles during a head-on interception. M A schematic diagram showing how the norm changes over time;

[0255] Figure 16 The diagram illustrates the change in total control consumption over time for four aircraft corresponding to four initial yaw angles during a head-on interception.

[0256] Comparing the results of Example 3 and Comparative Example 2, it can be seen that when the initial flight trajectory of the aircraft deviates significantly from the desired collision heading, the scheme in Comparative Example 2 fails to intercept the target due to guidance command divergence. This is because the ballistic shaping guidance law in Comparative Example 2 is designed based on a linearized kinematic model under the small-angle assumption. As the initial heading error increases, the small-angle assumption becomes difficult to satisfy, and the performance of the linear optimal guidance law deteriorates sharply. Simulation results show that, compared with the ballistic shaping guidance laws in Comparative Examples 1 and 2, the three-dimensional intersection vector constraint guidance method provided in Examples 2 and 3 under a large initial misalignment angle can tolerate a larger misalignment angle and has better guidance performance.

[0257] The present invention has been described above with reference to preferred embodiments; however, these embodiments are merely exemplary and illustrative. Various substitutions and modifications can be made to the present invention based on these embodiments, all of which fall within the scope of protection of the present invention.

Claims

1. A three-dimensional intersection vector constraint guidance method under an initial large misalignment angle, characterized in that, In this method: The aircraft with an initial large misalignment angle generates a lateral acceleration command in real time based on the acquired self-information and target information. This lateral acceleration command is used to control the servo motors to make rudder movements in real time. The rudder movements generate aerodynamic forces, which change the aircraft's trajectory and ultimately control the aircraft to hit the target. The lateral acceleration command is obtained through the following formula (I): (one) in, This indicates a lateral acceleration command; A unit vector representing the relative velocity between the aircraft and the target; Indicates the direction of the aircraft's velocity vector; Indicates perpendicular to normal acceleration; Represents the target's acceleration vector; Perpendicular to normal acceleration We obtain it through the following formula (II): (two) in, and Each represents the guidance gain coefficient independently; Represents the line-of-sight angular rate vector; Indicates the relative distance between the aircraft and the target; express The derivative; This indicates the magnitude of the relative velocity between the aircraft and the target; This represents the angle between the guidance plane and the plane containing the desired intersection vector; Indicates the velocity misalignment angle; This represents the angle between the predicted intersection direction and the expected intersection direction; express The normal vector of the unit vector in the guidance plane; express and The unit normal vector of the determined guidance plane; The line-of-sight angular rate vector We obtain it through the following formula (iii): (three) in, Indicates the direction of the line-of-sight vector between the aircraft and the target; Obtained through the following formula (VI): (six) in, Indicates the desired direction of the intersection vector; Indicates the predicted direction of the three-dimensional intersection vector at the end; We obtain it through the following formula (VII): (seven) in, Representing quaternions, ; Indicates the unit axis of rotation; Indicates the rotation angle; This represents the speed ratio between the aircraft and the target; Representing quaternions Conjugate; Represents a vector in an inertial coordinate system; Indicates the direction of the target's velocity vector.

2. The three-dimensional intersection vector constraint guidance method under an initial large misalignment angle according to claim 1, characterized in that, We obtain it through the following formula (iv): (Four) in, This indicates the desired direction of the intersection vector.

3. The three-dimensional intersection vector constraint guidance method under an initial large misalignment angle according to claim 1, characterized in that, speed misalignment angle Obtained through the following formula (5): (five).

4. The three-dimensional intersection vector constraint guidance method under an initial large misalignment angle according to claim 1, characterized in that, Obtained through the following formula (8): in, Representing quaternions, ; Representing quaternions Conjugate; express The rotation angle; express and The unit normal vector of the determined guidance plane.

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