Design method of rigid-flexible coupled missile attack angle controller composed of parafoil and missile

Abstract

The application provides a rigid-flexible coupling arrow attack angle controller design method constituted by a parafoil and an arrow, the parafoil is combined with a traditional arrow to form a rigid-flexible coupling arrow, and the parafoil attack angle is quickly adjusted to the vicinity of a target attack angle by controlling a flap deflection angle Φ of the parafoil to track a desired attack angle instruction of the parafoil, so that the response speed of the parafoil attack angle is greatly improved, and then the aerodynamic performance of the parafoil can be fully exerted, and the arrow can realize rapid, small-radius and large-angle agile turning.

Description

Technical Field

[0001] This invention belongs to the field of aircraft dynamics technology, and in particular relates to a design method for a rigid-flexible coupled projectile angle of attack controller consisting of a parachute and a projectile. Background Technology

[0002] A wing parachute is a flexible aircraft with a slit at its leading edge that uses ram air to maintain a certain shape. Controllability is the biggest difference between a wing parachute and a traditional parachute. By pulling the two control lines connected to the trailing edge of the wing parachute, the deflection angle of the trailing edge flaps is changed, thereby altering the aerodynamic forces and torque of the wing parachute, and thus controlling its flight attitude.

[0003] The combination of a parachute and a traditional projectile forms a rigid-flexible coupled projectile, enabling rapid, small-radius, and large-angle agile turns. Existing research indicates that the lift coefficient of the parachute is the main factor affecting the agile turning radius of the rigid-flexible coupled projectile, and the parachute's equilibrium angle of attack directly determines the magnitude of the lift coefficient. Therefore, by designing a parachute angle of attack controller and configuring the parachute's equilibrium angle of attack at the point of maximum lift coefficient, the aerodynamic performance of the parachute can be fully utilized, further improving the projectile's agile turning performance.

[0004] However, due to constraints in geometry and aerodynamic design, traditional projectile-type aircraft are facing bottlenecks in penetration capability and strike accuracy, gradually failing to meet the high-intensity demands of modern military operations. Traditional projectile-type aircraft are characterized by a large aspect ratio body and low aspect ratio wings, enabling supersonic or even supersonic flight. However, the low aspect ratio wings cannot provide the massive aerodynamic loads required for rapid maneuvering and turning, thus traditional projectile-type aircraft often fly along parabolic or large circular trajectories, lacking small-radius maneuverability. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a design method for a rigid-flexible coupled projectile angle-of-attack controller consisting of a parachute and a projectile, which can fully utilize the aerodynamic performance of the parachute to achieve rapid, small-radius, and large-angle agile turning of the projectile.

[0006] A design method for a rigid-flexible coupled missile angle of attack controller consisting of a parachute and a missile, wherein four parachute lines at the four corners of the parachute are connected to hinge point C, and the missile is connected to hinge point C through two other parachute lines; the parachute bends with the 75% chord length as the axis, and the bending angle Φ is the flap deflection angle.

[0007] Desired angle of attack for tracking paraglider The parachute angle-of-attack controller is as follows:

[0008]

[0009] Where, ω αω is the outer loop bandwidth of the parachute angle-of-attack controller. q The inner loop bandwidth of the parachute angle-of-attack controller. Let α be the desired angle of attack of the parachute in the parachute's centroid coordinate system {b}. b Let m be the actual angle of attack of the parachute in the parachute's centroid coordinate system {b}. p For the mass of the parachute, V B Let q be the magnitude of the velocity at the parachute's center of mass point B, q be the actual value of the parachute's pitch angular velocity, and a be the magnitude of the velocity at point B. (5) Let A be the state matrix in the parachute dynamics equation. -1 The row vector in the 5th row, B0 is the first observation matrix in the parachute dynamics equation, B Φ F is the second observation matrix in the parachute dynamics equations. N0 F is the component of the normal force perpendicular to the velocity vector at the parachute's center of mass point B, caused by the four parachute lines. Φ This is the additional force caused by the bending of the parachute in the normal force perpendicular to the velocity vector at the parachute's center of mass point B.

[0010] Furthermore, the parachute dynamics equations are as follows:

[0011]

[0012] Wherein, the state vector [uvw] T Let {b} be the projection of the velocity of point B, the center of mass of the parachute, onto the parachute's coordinate system {b}. For [uvw] T The derivative of; [pqr] T Let {b} be the projection of the parachute's rotational angular velocity onto the parachute's center-of-mass coordinate system. [pqr] T The derivative;

[0013]

[0014] in, For vectors The three-axis projection of the parachute's centroid coordinate system {b}, vector Let the parachute's center of mass B be the distance from the parachute's center of mass M to the parachute's additional mass center of mass. p The vector, for The antisymmetric matrix, I' a.m. For the additional mass matrix, I' a.i. To add the rotational inertia matrix, m p For parachute mass, I 3×3 It is a third-order identity matrix;

[0015] The first observation matrix B0 in the parachute dynamics equations is as follows:

[0016]

[0017] Among them, B 01 B is the first auxiliary variable. 02 Let be the second auxiliary variable, and we have:

[0018]

[0019] Where F is the first aerodynamic auxiliary matrix related to the aerodynamic force acting on the parachute center of pressure P. The force of gravity acting on the parachute. Let ω be the tension vector of the i-th parachute line at the four corner points of the parachute, i∈{1,2,3,4}, ω be the rotational angular velocity of the parachute in its own centroid coordinate system {b}, and S(ω) be the antisymmetric matrix of the rotational angular velocity ω.

[0020]

[0021] Where M is the first dynamic moment auxiliary matrix related to the parachute aerodynamic moment, r BP =[x BP y BP z BP ] T For vectors The three-axis projection of the parachute's centroid coordinate system {b}, vector Let S(r) be the vector from the parachute's center of mass B to its center of pressure P. BP ) is r BP antisymmetric matrix, Let j be the tension vector of the j-th parachute line connected to the missile, where j∈{1,2}. For vectors The three-axis projection of the parachute's centroid coordinate system {b}, vector Let the distance from the parachute's center of mass B to the left connection point L between the j-th parachute line and the missile be... j The vector, for antisymmetric matrix, For vectors The three-axis projection of the parachute's centroid coordinate system {b}, vector Let B be the point from the parachute's center of mass to the right connection point R between the j-th parachute line and the missile. j The vector, for The antisymmetric matrix;

[0022] The second observation matrix B in the parachute dynamics equation Φ as follows:

[0023]

[0024] Among them, F Φ M is the second aerodynamic auxiliary matrix related to the aerodynamic force acting on the parachute center of pressure P and the flap deflection angle Φ. Φ This is the auxiliary matrix for the second dynamic moment, which is related to the parachute aerodynamic moment and the flap deflection angle Φ.

[0025] Furthermore, the calculation method for the first aerodynamic auxiliary matrix F is as follows:

[0026]

[0027] Among them, the lift coefficient C of the parachute L The relationship between the flap deflection angle Φ and the linear function Ⅰ, f CD0 f is the intercept in the linear function relationship I. CL0 R is the intercept in the linear function relationship I. pb Let Q be the transformation matrix from the parachute's centroid coordinate system {b} (composed of the parachute and its lines) to the parachute's body coordinate system {p}. p For parachute dynamic pressure, S p R is the reference area of ​​the parachute. pa This is the transformation matrix from the parachute velocity coordinate system to the parachute body coordinate system;

[0028] Second aerodynamic auxiliary matrix F Φ The calculation method is as follows:

[0029]

[0030] Among them, the parachute drag coefficient C D The relationship between the flap deflection angle Φ and the flap deflection angle Φ is a linear function II, f CD1 f is the slope in the linear function relationship II. CL1 The slope in the linear function relationship II;

[0031] The method for calculating the first driving moment auxiliary matrix M is as follows:

[0032]

[0033] Among them, the parachute moment coefficient and the flap deflection angle Φ satisfy a linear functional relationship Ⅲ, f m0 C is the intercept in the linear function relationship III, and c is the aerodynamic chord length of the parachute. mq V is the derivative of the pitch damping moment coefficient of the parachute. p For parachute speed;

[0034] Second driving torque auxiliary matrix M Φ The calculation method is as follows:

[0035]

[0036] Among them, f m1 denoted as the slope in the linear function relationship III.

[0037] Furthermore, the normal force F perpendicular to the velocity vector at the parachute's center of mass point B... N for:

[0038]

[0039] in, To define symbols, Let F be the tension vector of the i-th parachute line at each of the four corner points of the parachute, i∈{1,2,3,4}. a.m. F represents the additional mass force acting on the parachute, and F is the first aerodynamic auxiliary matrix related to the aerodynamic force acting on the parachute's center of pressure P. Φ The second aerodynamic auxiliary matrix is ​​related to the aerodynamic force acting on the parachute center of pressure P and the flap deflection angle. Let {b} be the transition matrix from the velocity system to the parachute centroid coordinate system, and we have:

[0040]

[0041] Where, α b Let β be the actual angle of attack of the parachute in the parachute's centroid coordinate system {b}. b The actual sideslip angle of the parachute in the parachute's centroid coordinate system {b}, and β b =0, T represents transpose.

[0042] Furthermore, the calculation method for the first aerodynamic auxiliary matrix F is as follows:

[0043]

[0044] Among them, the lift coefficient C of the parachute L The relationship between the flap deflection angle Φ and the linear function Ⅰ, f CD0 f is the intercept in the linear function relationship I. CL0 R is the intercept in the linear function relationship I. pb Let Q be the transformation matrix from the volume coordinate system {b} of the parachute subsystem (composed of the parachute and parachute lines) to the parachute body coordinate system {p}. p For parachute dynamic pressure, S p R is the reference area of ​​the parachute. pa This is the transformation matrix from the parachute velocity coordinate system to the parachute body coordinate system;

[0045] Second aerodynamic auxiliary matrix F Φ The calculation method is as follows:

[0046]

[0047] Among them, the parachute drag coefficient CD The relationship between the flap deflection angle Φ and the flap deflection angle Φ is a linear function II, f CD1 f is the slope in the linear function relationship II. CL1 is the slope in the linear function relationship II.

[0048] Furthermore, the outer loop bandwidth ω of the parachute angle-of-attack controller α satisfy:

[0049]

[0050] in, Desired angle of attack for paraglider The rate of change;

[0051] Inner loop bandwidth ω of the parachute angle of attack controller q satisfy:

[0052]

[0053] in, Let q be the desired angular acceleration of the parachute's pitch angular velocity. c To obtain the rate of change The desired pitch rate is:

[0054]

[0055] Among them, F N The normal force is perpendicular to the velocity vector at point B, the center of mass of the parachute.

[0056] Beneficial effects:

[0057] This invention provides a design method for a rigid-flexible coupled projectile-launch angle-of-attack controller consisting of a parachute and a projectile. The method combines a parachute with a traditional projectile to form a rigid-flexible coupled projectile-launcher, and tracks the desired angle-of-attack command of the parachute by controlling the flap deflection angle Φ of the parachute. It can quickly adjust the parachute angle of attack to near the target angle of attack, greatly improving the response speed of the parachute angle of attack, and thus fully utilizing the aerodynamic performance of the parachute to achieve rapid, small-radius, and large-angle agile turns of the projectile. Attached Figure Description

[0058] Figure 1 The aerodynamic shape parameters of the parachute provided by this invention;

[0059] Figure 2 A schematic diagram of the parachute projectile system provided by the present invention;

[0060] Figure 3 A block diagram of the wing parachute angle of attack control system provided by the present invention;

[0061] Figure 4α is the simulation result of the parachute angle-of-attack controller provided by this invention. b Response curve;

[0062] Figure 5 α is the simulation result of the parachute angle-of-attack controller provided by this invention. p Response curve;

[0063] Figure 6 The simulation results of the parachute angle-of-attack controller provided by this invention show the parachute flap deflection angle response curve. Detailed Implementation

[0064] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0065] Step 1: Parameter Definition. The parachute bends at 75% of the chord length, that is, the wingtip bends downwards at 25% of the trailing edge. The bending angle Φ is called the flap deflection angle, such as... Figure 1 As shown.

[0066] This invention proposes a rigid-flexible coupled projectile-launch system, such as Figure 2 As shown, the system includes a wing parachute, parachute lines, parachute line connection points, and the missile, which are mounted on the side of the missile. The four parachute lines at the four corners of the wing parachute are connected to the hinge point C, and the missile is connected to the hinge point C by the other two parachute lines.

[0067] The relevant coordinate systems and reference points are defined as follows: {n} is the ground inertial coordinate system. {p} is the parachute body coordinate system, with the origin located at the parachute's center of pressure P. p Aligned with the parachute reference chord, pointing towards the leading edge as positive, Y p Perpendicular to the longitudinal plane of symmetry of the parachute, Z p With X p Y p This forms a right-handed rectangular coordinate system. {m} is the missile body coordinate system, with its origin at the missile's center of mass M, X... m Coinciding with the spring shaft, Y m Perpendicular to the longitudinal plane of symmetry of the missile. {b} is the body coordinate system of the subsystem consisting of the parachute, parachute lines, and control mechanism (hereinafter referred to as the parachute subsystem), with its origin located at the center of mass B of the parachute subsystem. b The axis lies within the longitudinal symmetry plane of the wing parachute system, and is related to the vector Parallel, point C is the point where the parachute lines meet. M p Add a center of mass to the parachute.

[0068] Step 2: Assumptions for the parachute aerodynamic model.

[0069] To simplify the controller design process, the following assumptions are made based on the parachute aerodynamic data:

[0070] (1) When the range of flight speed variation of the paraglider is small, its aerodynamic parameters are considered to be unrelated to the flight speed.

[0071] (2) Parachute lift coefficient C L drag coefficient C D It is the angle of attack α of the parachute p The nonlinear function is a linear function of the flap deflection angle Φ, i.e.

[0072]

[0073] Where f represents the angle of attack α of the parachute. p The coefficients of the polynomial function f are determined by data fitting. CD0 f is the intercept in the linear function relationship I. CL0 f is the intercept in the linear function relationship I; CD1 f is the slope in the linear function relationship II. CL1 is the slope in the linear function relationship II.

[0074] (3) Parachute moment coefficient C m,c / 4 It is the angle of attack α of the parachute p The nonlinear function is a linear function of the flap deflection angle Φ, and the parachute moment adjustment coefficient δ is defined. Cmp The formula for calculating the parachute moment coefficient is defined as follows:

[0075] C m,c / 4 =C Φ＝25° +δ Cmp (25-Φ)=f m0 +f m1 Φ (2)

[0076] By definition, f m0 =C Φ＝25° +25δ Cmp f m1 =-δ Cmp C Φ＝25° The expression is obtained by fitting the parachute pitching moment coefficient corresponding to Φ = 25°, and the moment adjustment coefficient δ Cmp The physical meaning is: when the angle of attack α of the parachute... p At a given time, increasing (decreasing) the flap deflection angle by 1° results in a decrease (increase) in the moment coefficient by a certain value. δ Cmp It characterizes the range of moment coefficients that can be covered when the deflection angle of the parachute flaps changes.

[0077] It should be noted that the parachute angle of attack α p It is calculated by projecting the velocity vector of the parachute's center of mass P onto the parachute's body coordinate system {p}. Similarly, the projection of the velocity vector of the parachute's center of mass B onto the coordinate system {b} can be used to define the angle of attack α. bα b With α p The difference exists due to the installation angle μ and the different velocity vectors at points P and B. However, the angle of attack α... b The dynamic equations can be directly obtained from the rotational dynamic equations, simplifying the design of the control system. Therefore, the wing parachute angle-of-attack controller described in this invention should strictly be defined as the angle of attack α. b For the sake of simplicity, the controller will still be referred to as the parachute angle-of-attack controller. α b With α p The difference will be distinguished by the context.

[0078] Step 3: Design of the parachute angle-of-attack controller

[0079] The parachute dynamics equation is

[0080]

[0081] Wherein, the state vector [uvw] T Let {b} be the projection of the velocity of point B, the center of mass of the parachute, onto the parachute's coordinate system {b}. For [uvw] T The derivative of; [pqr] T Let {b} be the projection of the parachute's rotational angular velocity onto the parachute's center-of-mass coordinate system. [pqr] T The derivative; and we have:

[0082]

[0083] in, For vectors The three-axis projection of the parachute's centroid coordinate system {b}, vector Let the parachute's center of mass B be the distance from the parachute's center of mass M to the parachute's additional mass center of mass. p The vector, for The antisymmetric matrix, I' a.m. For the additional mass matrix, I' a.i. To add the rotational inertia matrix, m p For parachute mass, I 3×3 It is a third-order identity matrix;

[0084] The first observation matrix B0 and the second observation matrix B in the parachute dynamics equations are derived below. Φ The expression.

[0085] Considering only the motion in the longitudinal plane, the aerodynamic force acting on the parachute center of pressure P and parachute aerodynamic torque The calculation formula is:

[0086]

[0087]

[0088] Q p For dynamic pressure. Substituting equations (5) and (6) into (3), we get

[0089]

[0090] Among them, B 01 B is the first auxiliary variable. 02 F is the second auxiliary variable. Φ M is the second aerodynamic auxiliary matrix related to the aerodynamic force acting on the parachute center of pressure P and the flap deflection angle Φ. Φ Let be the auxiliary matrix of the second dynamic moment related to the parachute aerodynamic moment and the flap deflection angle Φ, and we have:

[0091]

[0092] Where F is the first aerodynamic auxiliary matrix related to the aerodynamic force acting on the parachute center of pressure P. The force of gravity acting on the parachute. Let ω be the tension vector of the i-th parachute line at the four corner points of the parachute, i∈{1,2,3,4}, ω be the rotational angular velocity of the parachute in its own centroid coordinate system {b}, and S(ω) be the antisymmetric matrix of the rotational angular velocity ω.

[0093]

[0094] Where M is the first dynamic moment auxiliary matrix related to the parachute aerodynamic moment, r BP =[x BP y BP z BP ] T For vectors The three-axis projection of the parachute's centroid coordinate system {b}, vector Let S(r) be the vector from the parachute's center of mass B to its center of pressure P. BP ) is r BP antisymmetric matrix, Let j be the tension vector of the j-th parachute line connected to the missile, where j∈{1,2}. For vectors The three-axis projection of the parachute's centroid coordinate system {b}, vector Let the distance from the parachute's center of mass B to the left connection point L between the j-th parachute line and the missile be... j The vector, for antisymmetric matrix, For vectors The three-axis projection of the parachute's centroid coordinate system {b}, vector Let B be the point from the parachute's center of mass to the right connection point R between the j-th parachute line and the missile. j The vector, for The antisymmetric matrix;

[0095] The method for calculating the first driving moment auxiliary matrix M is as follows:

[0096]

[0097] Among them, the parachute moment coefficient and the flap deflection angle Φ satisfy a linear functional relationship Ⅲ, f m0 C is the intercept in the linear function relationship III, and c is the aerodynamic chord length of the parachute. mq V is the derivative of the pitch damping moment coefficient of the parachute. p For parachute speed;

[0098] Second driving torque auxiliary matrix M Φ The calculation method is as follows:

[0099]

[0100] Among them, f m1 denoted as the slope in the linear function relationship III.

[0101] The dynamic equation for the pitch velocity of the parachute is:

[0102]

[0103] Where a (5) It is the corresponding matrix A -1 The row vector in the 5th row.

[0104] To further simplify the design process, the first derivative term of the added mass force of the parachute is ignored, i.e.

[0105]

[0106] At this point, matrix A in equation (4) is

[0107]

[0108] The parachute angle-of-attack controller includes inner-loop dynamic inverse and outer-loop dynamic inverse, such as... Figure 3 As shown, the outer ring calculates the desired pitch rate based on the angle-of-attack command, while the inner ring calculates the pitch rate based on the pitch rate command. Calculate the control command Φ.

[0109] The actual angle of attack α of the parachute in the parachute's centroid coordinate system {b} bThe dynamic equation in the longitudinal plane is:

[0110]

[0111] Among them, F N V is the normal force perpendicular to the velocity vector at the center of mass point B of the parachute. B Let F be the magnitude of the velocity at the center of mass B. B Let be the resultant force acting at point B, projected onto the velocity system defined by point B.

[0112]

[0113] R ba Let β be the transition matrix from the velocity system to the {b} system, where β b =0

[0114]

[0115] Where, α b Let β be the actual angle of attack of the parachute in the parachute's centroid coordinate system {b}. b The actual sideslip angle of the parachute in the parachute's centroid coordinate system {b}, and β b =0, T denotes transpose;

[0116] Then F N It can be expressed as

[0117]

[0118] Where F N0 F NΦ As a scalar, To define symbols, Let F be the tension vector of the i-th parachute line at each of the four corner points of the parachute, i∈{1,2,3,4}. a.m. F represents the additional mass force acting on the parachute, and F is the first aerodynamic auxiliary matrix related to the aerodynamic force acting on the parachute's center of pressure P. Φ The second aerodynamic auxiliary matrix is ​​related to the aerodynamic force acting on the parachute center of pressure P and the flap deflection angle. Let {b} be the transition matrix from the velocity system to the parachute centroid coordinate system, and we have:

[0119] The method for calculating the first aerodynamic auxiliary matrix F is as follows:

[0120]

[0121] Among them, the lift coefficient C of the parachute L The relationship between the flap deflection angle Φ and the linear function Ⅰ, f CD0 f is the intercept in the linear function relationship I. CL0R is the slope in the linear function relationship I. pb Let Q be the transformation matrix from the parachute centroid coordinate system {b} to the parachute body coordinate system {p}. p For parachute dynamic pressure, S p R is the reference area of ​​the parachute. pa This is the transformation matrix from the parachute velocity coordinate system to the parachute body coordinate system;

[0122] Second aerodynamic auxiliary matrix F Φ The calculation method is as follows:

[0123]

[0124] Among them, the parachute drag coefficient C D The relationship between the flap deflection angle Φ and the flap deflection angle Φ is a linear function II, f CD1 f is the intercept in the linear function relation II. CL1 The slope in the linear function relationship II;

[0125] Desired Angle of Attack of the Parachute in the Parachute Center-of-Mass Coordinate System {b} and feedback quantity α b Used to calculate error Desired rate of change of angle of attack for

[0126]

[0127] Where ω α Let be the outer ring bandwidth. The aforementioned angle-of-attack variation rate is achieved using equation (14). Required angular velocity command q c for

[0128]

[0129] Angular velocity command q c And the feedback quantity q is used to calculate the error e. q =q c -q. The desired angular acceleration command. for

[0130]

[0131] Where ω q Let (20) be the inner loop bandwidth. Substituting equation (20) into (11), we obtain the flap deflection angle command.

[0132]

[0133] Substituting equations (20), (19), and (17) into equation (21),

[0134]

[0135] Both ends of equation (22) contain Φ. Solve for the flap deflection angle command Φ.

[0136]

[0137] The performance of the flap deflection angle command Φ of the present invention will be analyzed below.

[0138] make

[0139]

[0140] According to equation (20), the time-domain response of the pitch angular velocity is:

[0141]

[0142] Substituting equation (25) into equation (14), we obtain the rate of change of angle of attack.

[0143]

[0144] Substituting equation (19) into the equation,

[0145]

[0146] Therefore, it can be seen that when the inner loop bandwidth ω of the parachute angle-of-attack controller... q Much larger than the outer loop bandwidth ω of the parachute angle-of-attack controller α , such as ω q At least greater than ω α At three orders of magnitude, the response speed of the inner-ring dynamic inverse is much greater than that of the outer-ring dynamic inverse. At this point, the wing parachute angle-of-attack dynamics is transformed into a time constant of T = 1 / ω. α A first-order system.

[0147] When the inner loop bandwidth ω of the parachute angle-of-attack controller q Much larger than the outer loop bandwidth ω of the parachute angle-of-attack controller α , such as ω q At least greater than ω α At three orders of magnitude, the wing parachute angle-of-attack dynamics will be closer to a first-order process, but due to ω q Maximum boundary constraint, ω α This condition is only satisfied when the smaller value is taken, in which case the angle of attack α b The response speed is too slow, so ω will be relaxed in the actual simulation process. q Much greater than ω αThe condition is no longer required to be much greater than the target angle of attack; the inner loop bandwidth and outer loop bandwidth can be of the same order of magnitude, which can improve the angle-of-attack response speed. In other words, the missile's agile turning process is short, and only by quickly adjusting the wing parachute angle of attack to near the target angle of attack can the advantages of the closed-loop system over the open-loop system be highlighted. Therefore, in actual simulations, ω will be relaxed. q With ω α The relative size of the parachute is constrained to improve the response speed of the angle of attack. At the same time, the angle of attack response process will experience some oscillations, but this will not adversely affect the system stability or the missile's agile turning performance.

[0148] The parameters of the parachute missile system are shown in Table 1.

[0149] Table 1 Parachute System Parameters

[0150]

[0151] Select δ Cmp =0.02, ω α =60Hz, ω q =80Hz, missile thrust P=28000N. Given parachute angle of attack command. A time-domain simulation was performed with a simulation time of 0.5 seconds. The simulation results are as follows: Figures 4-6 As shown. α b All converge to the angle of attack command value, α p The angles converged sequentially to -0.82°, 1.38°, and 3.53°. The flap deflection angles did not saturate.

[0152] In practical applications, the angle of attack command for the parachute should be given based on the parachute aerodynamic data. For example, the angle of attack corresponding to the point where the parachute lift coefficient reaches its maximum value can be used as the angle of attack command.

[0153] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A design method for a rigid-flexible coupled projectile angle-of-attack controller consisting of a parachute and a projectile, characterized in that, The four parachute lines at the four corners of the parachute are connected to hinge point C, and the missile is connected to hinge point C via two other parachute lines; the parachute bends around the 75% chord length axis, and the bending angle Φ is the flap deflection angle. Desired angle of attack for tracking paraglider The parachute angle-of-attack controller is as follows: Where, ω α ω is the outer loop bandwidth of the parachute angle-of-attack controller. q The inner loop bandwidth of the parachute angle-of-attack controller. Let α be the desired angle of attack of the parachute in the parachute's centroid coordinate system {b}. b Let m be the actual angle of attack of the parachute in the parachute's centroid coordinate system {b}. p For the mass of the parachute, V B Let q be the magnitude of the velocity at the parachute's center of mass point B, q be the actual value of the parachute's pitch angular velocity, and a be the magnitude of the velocity at point B. (5) Let A be the state matrix in the parachute dynamics equation. -1 The row vector in the 5th row, B0 is the first observation matrix in the parachute dynamics equation, B Φ F is the second observation matrix in the parachute dynamics equations. N0 F is the component of the normal force perpendicular to the velocity vector at the parachute's center of mass point B, caused by the four parachute lines. Φ The additional force caused by the bending of the parachute is in the normal force perpendicular to the velocity vector of the parachute's center of mass point B; The parachute dynamics equations are as follows: Wherein, the state vector [uvw] T Let {b} be the projection of the velocity of point B, the center of mass of the parachute, onto the parachute's coordinate system {b}. For [uvw] T The derivative of; [pqr] T Let {b} be the projection of the parachute's rotational angular velocity onto the parachute's center-of-mass coordinate system. [pqr] T The derivative; in, For vectors The three-axis projection of the parachute's centroid coordinate system {b}, vector Let the parachute's center of mass B be the distance from the parachute's center of mass M to the parachute's additional mass center of mass. p The vector, for The antisymmetric matrix, I' a.m. For the additional mass matrix, I' a.i. To add the rotational inertia matrix, m p For parachute mass, I 3×3 It is a third-order identity matrix; The first observation matrix B0 in the parachute dynamics equations is as follows: Among them, B 01 B is the first auxiliary variable. 02 Let be the second auxiliary variable, and we have: Where F is the first aerodynamic auxiliary matrix related to the aerodynamic force acting on the parachute center of pressure P. The force of gravity acting on the parachute. Let ω be the tension vector of the i-th parachute line at the four corner points of the parachute, i∈{1,2,3,4}, ω be the rotational angular velocity of the parachute in its own centroid coordinate system {b}, and S(ω) be the antisymmetric matrix of the rotational angular velocity ω. Where M is the first dynamic moment auxiliary matrix related to the parachute aerodynamic moment, r BP =[x BP y BP z BP ] T For vectors The three-axis projection of the parachute's centroid coordinate system {b}, vector Let S(r) be the vector from the parachute's center of mass B to its center of pressure P. BP ) is r BP antisymmetric matrix, Let j be the tension vector of the j-th parachute line connected to the missile, where j∈{1,2}. For vectors The three-axis projection of the parachute's centroid coordinate system {b}, vector Let the distance from the parachute's center of mass B to the left connection point L between the j-th parachute line and the missile be... j The vector, for antisymmetric matrix, For vectors The three-axis projection of the parachute's centroid coordinate system {b}, vector Let B be the point from the parachute's center of mass to the right connection point R between the j-th parachute line and the missile. j The vector, for The antisymmetric matrix; The second observation matrix B in the parachute dynamics equation Φ as follows: Among them, F Φ M is the second aerodynamic auxiliary matrix related to the aerodynamic force acting on the parachute center of pressure P and the flap deflection angle Φ. Φ This is the auxiliary matrix for the second dynamic moment, which is related to the parachute aerodynamic moment and the flap deflection angle Φ.

2. The design method of a rigid-flexible coupled projectile angle-of-attack controller consisting of a parachute and a projectile as described in claim 1, characterized in that, The method for calculating the first aerodynamic auxiliary matrix F is as follows: Among them, the lift coefficient C of the parachute L The relationship between the flap deflection angle Φ and the linear function Ⅰ, f CD0 f is the intercept in the linear function relationship I. CL0 R is the intercept in the linear function relationship I. pb Let Q be the transformation matrix from the parachute's centroid coordinate system {b} (composed of the parachute and its lines) to the parachute's body coordinate system {p}. p For parachute dynamic pressure, S p R is the reference area of ​​the parachute. pa This is the transformation matrix from the parachute velocity coordinate system to the parachute body coordinate system; Second aerodynamic auxiliary matrix F Φ The calculation method is as follows: Among them, the parachute drag coefficient C D The relationship between the flap deflection angle Φ and the flap deflection angle Φ is a linear function II, f CD1 f is the slope in the linear function relationship II. CL1 The slope in the linear function relationship II; The method for calculating the first driving moment auxiliary matrix M is as follows: Among them, the parachute moment coefficient and the flap deflection angle Φ satisfy a linear functional relationship Ⅲ, f m0 C is the intercept in the linear function relationship III, and c is the aerodynamic chord length of the parachute. mq V is the derivative of the pitch damping moment coefficient of the parachute. p For parachute speed; Second driving torque auxiliary matrix M Φ The calculation method is as follows: Among them, f m1 denoted as the slope in the linear function relationship III.

3. The design method of a rigid-flexible coupled projectile angle-of-attack controller consisting of a parachute and a projectile as described in claim 1, characterized in that, The normal force F perpendicular to the velocity vector at the center of mass point B of the parachute N for: in, To define symbols, Let F be the tension vector of the i-th parachute line at each of the four corner points of the parachute, i∈{1,2,3,4}. a.m. F represents the additional mass force acting on the parachute, and F is the first aerodynamic auxiliary matrix related to the aerodynamic force acting on the parachute's center of pressure P. Φ The second aerodynamic auxiliary matrix is ​​related to the aerodynamic force acting on the parachute center of pressure P and the flap deflection angle. Let F be the transition matrix from the velocity frame to the parachute center-of-mass coordinate system {b}. NΦ To be compatible with the second aerodynamic auxiliary matrix F Φ and transition matrix The relevant auxiliary matrices are: Where, α b Let β be the actual angle of attack of the parachute in the parachute's centroid coordinate system {b}. b The actual sideslip angle of the parachute in the parachute's centroid coordinate system {b}, and β b =0, T represents transpose.

4. The design method of a rigid-flexible coupled projectile angle-of-attack controller consisting of a parachute and a projectile as described in claim 3, characterized in that, The method for calculating the first aerodynamic auxiliary matrix F is as follows: Among them, the lift coefficient C of the parachute L The relationship between the flap deflection angle Φ and the linear function Ⅰ, f CD0 f is the intercept in the linear function relationship I. CL0 R is the intercept in the linear function relationship I. pb Let Q be the transformation matrix from the volume coordinate system {b} of the parachute subsystem (composed of the parachute and parachute lines) to the parachute body coordinate system {p}. p For parachute dynamic pressure, S p R is the reference area of ​​the parachute. pa This is the transformation matrix from the parachute velocity coordinate system to the parachute body coordinate system; Second aerodynamic auxiliary matrix F Φ The calculation method is as follows: Among them, the parachute drag coefficient C D The relationship between the flap deflection angle Φ and the flap deflection angle Φ is a linear function II, f CD1 f is the slope in the linear function relationship II. CL1 is the slope in the linear function relationship II.

5. The design method of a rigid-flexible coupled projectile angle-of-attack controller consisting of a parachute and a projectile as described in claim 1, characterized in that, The outer loop bandwidth ω of the parachute angle-of-attack controller α satisfy: in, Desired angle of attack for paraglider The rate of change; Inner loop bandwidth ω of the parachute angle of attack controller q satisfy: in, Let q be the desired angular acceleration of the parachute's pitch angular velocity. c To obtain the rate of change The desired pitch rate is: Among them, F N The normal force is perpendicular to the velocity vector at point B, the center of mass of the parachute.

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