Stability assessment method, device, electronic equipment and medium for stratospheric airship

Abstract

The present invention provides a method, device, electronic device and non-transitory computer-readable storage medium for evaluating the stability of a stratospheric airship, wherein the method comprises: obtaining a parameterized model of the elliptical shape structure of the stratospheric airship; obtaining a first correlation relationship between the moment and the airflow angle of the stratospheric airship in a floating state according to the parameters of the parameterized model; and evaluating the stability of the stratospheric airship according to the current airflow angle and the first correlation relationship. The technical solution of the embodiment of the present invention can quantitatively evaluate the stability of a stratospheric airship in a floating state, providing a basis for the safety and control of the stratospheric airship.

Description

Technical Field

[0001] The present invention relates to the technical field of stratospheric airships, and in particular to a stability assessment method, device, electronic equipment, and non-transient computer-readable storage medium for a stratospheric airship. Background Art

[0002] Stratospheric airships are aircraft that use helium and other buoyant gases to provide static lift, rely on propulsion systems and control systems, and can stay at fixed points or maneuver at low speeds at stratospheric altitudes to complete specific tasks. Stratospheric airships have the advantages of long airborne time, large payload, high cost-effectiveness, good stealth performance, and strong survivability, and have been widely used in military reconnaissance, scientific observation, cargo transportation, and other fields.

[0003] When a stratospheric airship is flying for a long time, it does not need to rely on power propulsion all the time, but can float in the air to save energy, so that the airship can remain hovering or stationary. The performance of a stratospheric airship in powered flight will affect flight safety. At present, based on domestic and foreign research on the stability of stratospheric airships during powered flight, it is shown that stratospheric airships are unstable at low angles of attack or sideslip angles.

[0004] The motion performance of a stratospheric airship in free flight affects flight safety in the same way as in powered flight. Usually, when a stratospheric airship is in powered flight, aerodynamic forces and torques can be obtained by linearizing the six-degree-of-freedom motion equation. However, when the airship is in flight, the speed is close to 0. In the method of obtaining aerodynamic coefficients by linearizing the motion equation, in the extreme state where the speed is close to 0, the aerodynamic coefficients of typical powered flight cannot accurately describe the external forces on the airship in the flying state.

[0005] The quantitative evaluation of the lateral and longitudinal static stability of stratospheric airships while flying is a technical problem that needs to be solved urgently. Summary of the invention

[0006] The present invention provides a method and device for evaluating the stability of a stratospheric airship, which are used to solve the defect in the prior art that the stability of a stratospheric airship in a flying state cannot be evaluated, and realizes quantitative stability evaluation of the stratospheric airship.

[0007] The present invention provides a method for evaluating the stability of a stratospheric airship, comprising: obtaining a parameterized model of an elliptical outer structure of the stratospheric airship; obtaining a first correlation relationship between a moment and an airflow angle applied to the stratospheric airship in a flying state according to parameters of the parameterized model; and evaluating the stability of the stratospheric airship according to a current airflow angle and the moment formula.

[0008] According to a method for evaluating the stability of a stratospheric airship provided by the present invention, the evaluating the stability of the stratospheric airship according to the current airflow angle and the torque formula includes: obtaining the slope of the torque with respect to the current airflow angle; when the slope is less than 0, determining that the current airflow angle is in an increasing process; when the slope is greater than 0, determining that the current airflow angle is in a decreasing process.

[0009] According to a method for evaluating the stability of a stratospheric airship provided by the present invention, the elliptical outer shape structure includes an elliptical plane structure.

[0010] According to a method for evaluating the stability of a stratospheric airship provided by the present invention, a first correlation relationship between the moment received by the stratospheric airship in a floating state and the airflow angle is obtained according to the parameters of the parameterized model, including: obtaining a second correlation relationship between the complex potential when the fluid bypasses an obstacle and the parameters of the parameterized model; and obtaining a first correlation relationship between the moment received by the stratospheric airship and the airflow angle according to the parameters of the parameterized model and the second correlation relationship between the complex potential and the parameters of the parameterized model.

[0011] According to a stability assessment method for a stratospheric airship provided by the present invention,

[0012] The first association relationship includes:

[0013]

[0014] Where, ρ is the air density, V ∞ is the far-field flow velocity, a and b are the semi-major axis and semi-minor axis of the ellipse of the elliptical plane structure, and α is the airflow angle.

[0015] According to a method for evaluating the stability of a stratospheric airship provided by the present invention, the elliptical outer shape structure includes an ellipsoid structure or an ellipsoid-like spiral structure.

[0016] According to a method for evaluating the stability of a stratospheric airship provided by the present invention, the first correlation relationship formula includes:

[0017]

[0018] Among them, V ∞ is the far-field velocity, ρ is the air density,

[0019] a and b are the semi-major axis and semi-minor axis of the ellipse of the ellipsoid structure, and α is the airflow angle.

[0020] The present invention also provides another device for evaluating the stability of a stratospheric airship, comprising: an acquisition unit, used to acquire an elliptical shape structure corresponding to the shape of the stratospheric airship; a calculation unit, used to obtain a first correlation relationship between the moment exerted on the stratospheric airship and the airflow angle according to the parameters of the parameterized model; and an evaluation unit, used to evaluate the stability of the stratospheric airship according to the current airflow angle and the moment formula.

[0021] According to a stability assessment device for a stratospheric airship provided by the present invention, the assessment unit is further used to obtain the slope of the torque with respect to the current airflow angle; when the slope is less than 0, it is determined that the current airflow angle is in an increasing process; when the slope is greater than 0, it is determined that the current airflow angle is in a decreasing process.

[0022] According to a stability assessment device for a stratospheric airship provided by the present invention, the calculation unit is further used to obtain a second relationship between a complex potential when a fluid bypasses an obstacle and a parameter of the parameterized model; and according to the parameters of the parameterized model and the second relationship between the complex potential and the parameters of the parameterized model, a first correlation relationship between the torque applied to the stratospheric airship and the airflow angle is obtained.

[0023] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of any of the above-mentioned methods for evaluating the stability of a stratospheric airship are implemented.

[0024] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of any of the above-mentioned methods for evaluating the stability of a stratospheric airship are implemented.

[0025] The method and device for evaluating the stability of a stratospheric airship provided by the present invention evaluate the stability of the stratospheric airship by combining the elliptical shape structure corresponding to the stratospheric airship with the first correlation relationship between the moment exerted on the stratospheric airship and the airflow angle and the current airflow angle, thereby achieving a quantitative evaluation of the stability of the stratospheric airship in a flying state, providing important reference data for the safety and control of the stratospheric airship, and facilitating the safe operation of the stratospheric airship. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 It is a schematic flow chart of the stability assessment method of a stratospheric airship provided by the present invention;

[0028] Figure 2 is a schematic diagram of the flow of airflow provided by the present invention when it flows through an elliptical plane;

[0029] Figure 3 It is a flow chart of the process of obtaining the torque formula provided by the present invention;

[0030] Figure 4 It is a structural schematic diagram of a stability assessment device for a stratospheric airship provided by the present invention;

[0031] Figure 5 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The motion performance of a stratospheric airship in free-flying state and in powered flight state both affect flight safety. In the related art, when a stratospheric airship is in powered flight, aerodynamic forces and torques can be obtained by linearizing the six-degree-of-freedom motion equations. However, in this method of obtaining aerodynamic coefficients by linearizing the motion equations, the aerodynamic coefficients of typical powered flight cannot accurately describe the external forces on the airship in the flying state.

[0034] The existing technology cannot quantitatively evaluate the stability of a stratospheric airship in a floating state. However, clarifying the stability data of a stratospheric airship in a floating state and clarifying the difference in stability between a stratospheric airship in a floating state and a powered flight state are of great significance to the flight safety and control of the stratospheric airship.

[0035] To solve this technical problem, embodiments of the invention provide a stability assessment method, device, electronic device, and non-transitory computer-readable storage medium for a stratospheric airship.

[0036] The following is an explanation of the terms in the present invention:

[0037] The airflow angle includes the angle of attack and the sideslip angle of the airflow.

[0038] The angle of attack, also known as the angle of attack, refers to the angle between the projection of the aircraft's velocity direction line in the aircraft's symmetry plane and the chord line of the wing. During flight, the aerodynamic force acting on the airship is related to the angle of attack. Within a certain range of angles of attack, increasing the angle of attack increases both the lift coefficient and the drag coefficient.

[0039] The sideslip angle refers to the angle between the aircraft's flight velocity vector and its longitudinal symmetry plane. If the velocity vector is to the right of the symmetry plane, the corresponding sideslip angle is positive, otherwise it is negative. The sideslip angle is an important parameter for determining the aircraft's flight attitude.

[0040] Combine the following Figures 1 to 5 Exemplary embodiments of the present invention are described in detail.

[0041] like Figure 1 FIG. 1 is a flow chart of a method for evaluating the stability of a stratospheric airship according to an embodiment of the present invention. The method provided by the embodiment of the present invention can be executed by any electronic device with computer processing capabilities, such as a terminal device or a server. Figure 1 As shown, the stability assessment method of the stratospheric airship includes:

[0042] Step 102, obtaining a parameterized model of the elliptical outer structure of the stratospheric airship.

[0043] Specifically, a stratospheric airship is an aircraft that can be suspended at high altitudes in the stratosphere for a long time. The elliptical shape structure is a model structure obtained by modeling the shape of the stratospheric airship, and the elliptical shape structure can be an elliptical plane, an ellipsoid, or an ellipsoid-like rotation body. In the present invention, the influence of the tail of the stratospheric airship is ignored, and the stratospheric airship is matched with the elliptical shape structure model, which can be used to calculate the lift and torque of the airflow on the stratospheric airship in the flying state, and then analyze the stability of the stratospheric airship in the flying state. The parameters of the parameterized model include the major semi-axis, minor semi-axis and focal radius of the elliptical plane, as well as the volume, additional mass coefficient and rotation coefficient of the ellipsoid or ellipsoid-like rotation body.

[0044] Step 104 , obtaining a first correlation relationship between the moment exerted on the stratospheric airship in the flying state and the airflow angle according to the parameters of the parameterized model.

[0045] Specifically, the suspension state refers to the state in which the stratospheric airship turns off the power device and is suspended or hovering in the stratosphere only by the buoyancy of the airbag. Lift refers to the force of the airflow acting on the stratospheric airship to lift the stratospheric airship.

[0046] Step 106 evaluates the stability of the stratospheric airship according to the current airflow angle and the first correlation relationship.

[0047] Specifically, when evaluating the stability of a stratospheric airship, it is first necessary to obtain the torque of the force of the current airflow acting on the stratospheric airship, and quantitatively analyze the stability of the stratospheric airship according to the change of the torque.

[0048] Since the tail wing has almost no effect on stability when the stratospheric airship is in a floating state, that is, when the airspeed is very low, the tail wing is ignored in the technical solution of the embodiment of the present invention, and the streamlined body of the stratospheric airship is simplified to obtain an elliptical shape structure, and the lift force on the stratospheric airship based on the elliptical shape structure and the airflow is analyzed, and the stability of the stratospheric airship is evaluated according to the analysis results. This solution makes up for the deficiency that the method of obtaining aerodynamic coefficients by linearizing the motion equation in the prior art is only applicable to the stability evaluation of the stratospheric airship, and provides quantitative evaluation data to ensure the safety and control of the floating state of the stratospheric airship, which is of great significance to the flight safety and control of the stratospheric airship.

[0049] In the embodiment of the present invention, the stratospheric airship still has a relatively small airspeed in the flying state, and the airspeed is opposite to or in the same direction as the wind speed, that is, in a collinear relationship. The airspeed refers to the speed of the aircraft relative to the air, and the unit is KM / H or NM / H. It is a necessary parameter for calculating the aerodynamics of the aircraft and an important basis for calculating the range of the aircraft. Therefore, it is also an essential parameter for the flight of the aircraft. In the following description of the specification, only the speed of the airflow is used for relevant calculations, and the airspeed and wind speed are no longer distinguished.

[0050] In step 106, the slope of the moment with respect to the current airflow angle can be obtained, and the change of the moment can be determined according to the positive and negative conditions of the slope. When the moment is 0, the angle of the current airflow angle is recorded as the balance point, and the airflow angle is 0° or 90° at this time. When the slope of the moment is less than 0, the current moment is in a decreasing state, and it can be determined that the current airflow angle is in an increasing process; when the slope is greater than 0, the current moment is in an increasing state, and it can be determined that the current airflow angle is in a decreasing process.

[0051] The technical solution of the present invention is described in detail below by taking the elliptical shape structure as an elliptical plane structure and an ellipsoid structure as examples.

[0052] Embodiment 1

[0053] In the embodiment of the present invention, the elliptical shape structure is an elliptical plane structure. Figure 2 The figure shows the flow of airflow when the airflow passes through a stratospheric airship with a simplified structure of an elliptical plane at an airflow angle α. Here, the airflow angle α is the angle of attack. The line connecting the bow and the stern is the major axis of the ellipse. In the xy plane coordinate system, the major axis is along the direction of the x-axis, and the minor axis of the ellipse is along the direction of the y-axis.

[0054] like Figure 3 As shown, step 104 includes the following steps:

[0055] Step 1041 , obtaining a second correlation between the complex potential of the fluid when it bypasses an obstacle and the parameters of the parameterized model.

[0056] Specifically, suppose an incompressible fluid performs a steady motion on a plane, and the velocity vector is equivalent to is an analytical function, called the complex velocity of the fluid, It is independent of the integration path and is called the complex potential of the fluid. Many properties of fluid motion can be expressed by complex potential and complex velocity. The flow problem of a fluid bypassing an obstacle, i.e., the flow problem, can be transformed into a boundary value problem of complex potential.

[0057] Step 1042: Obtain a first correlation relationship between the moment acting on the stratospheric airship and the airflow angle according to the parameters of the parameterized model and the second correlation relationship.

[0058] Specifically, the velocity potential is related to the velocity circulation of the flow field, and the lift and the torque of the lift about the airflow angle are also related to the velocity circulation. Therefore, according to the calculation formula of the complex potential and its derivative, the constants in the torque formula can be obtained, and then the required torque formula can be obtained.

[0059] In the plane irrotational flow of an ideal incompressible fluid, the lift force exerted on an object by the fluid can be calculated according to the Kutta-Joukowski lift theorem.

[0060] Here, the Kutta–Joukowski theorem is a basic theorem of aerodynamics, which is used to calculate the lift of a wing or a two-dimensional object including a cylinder in a uniform fluid. In this theorem, lift is related to the relative velocity between the wing or cylinder and the fluid, the density of the fluid, and the circulation. Among them, circulation is defined as the line integral of the fluid velocity along a curved cylindrical object around a cylinder or wing, and its magnitude and direction will change along the path. The Kutta–Joukowski theorem establishes the relationship between lift and circulation.

[0061] According to the Kutta-Joukowski lift theorem, we can get formula (1):

[0062] F=ρV ∞ ×Γ (1)

[0063] Where F is lift, ρ is air density, V ∞ is the far-field velocity, and Γ is the velocity circulation.

[0064] The calculation formula of the moment M is formula (2):

[0065]

[0066] Where ρ is the air density, V ∞is the far-field velocity, Γ is the velocity circulation, Re is the real part, i is the imaginary part, e is a natural constant, α is the airflow angle, Ai is the coefficient, i = 1, 2, ..., n, and n is a natural number.

[0067] The calculation formula of the derivative of the complex potential W with respect to z when the fluid bypasses the obstacle obtained in step 1041 can be formula (3):

[0068]

[0069] Formula (3) can characterize the second correlation relationship between the complex potential and the parameters of the parameterized model.

[0070] Where ρ is the air density, V ∞ is the far-field velocity, Γ is the velocity circulation, Re is the real part, I is the imaginary part, e is a natural constant, α is the airflow angle, Ai is the coefficient, i = 1, 2, ..., n, and n is a natural number, and Q is the airflow flow rate.

[0071] In step 1042, the parameters of the elliptical plane structure are: the semi-major axis of the ellipse of the elliptical plane structure is a, the semi-minor axis is b, and the focal radius is c.

[0072] Substituting the parameters of the parameterized model into the calculation formula of the complex potential, we can obtain the complex potential of the uniform flow flowing through the ellipse at the airflow angle α as formula (4):

[0073]

[0074] By taking the derivative of formula (4), we can obtain the calculation formula of the derivative of the complex potential W with respect to z, which is formula (5):

[0075]

[0076] Using the series expansion formula (6):

[0077]

[0078] The coefficient A2 of dW / dz can be obtained as formula (7):

[0079]

[0080] Substituting Γ = 0 and A2 into formula (2), the torque formula can be obtained as formula (8):

[0081]

[0082] Formula (8) can represent the first correlation between the torque and the airflow angle α.

[0083] Comparison Figure 2From the xy coordinate system, it can be seen that when the airflow is longitudinal and the airflow angle is angle of attack β1, when the moment M is positive, it is a counterclockwise moment, which makes the stratospheric airship lower its head, that is, a stabilizing moment; when M is negative, it is a clockwise moment, which makes the stratospheric airship raise its head. There are two equilibrium points where the moment M is 0, which are angle of attack β1 = 0° and β1 = 90°, or angle of attack β1 = 180° and β1 = 270°.

[0084] By calculating the slope of the moment in formula (8) with respect to the airflow angle α, we can obtain formula (9):

[0085]

[0086] When the airflow is longitudinal, the airflow angle α is the angle of attack β1. When the angle of attack β1 gradually increases from 0°, δM<0, so that the pitch moment M increases clockwise, and the angle of attack β1 continues to increase, so the angle of attack β1 at 0° is an unstable equilibrium point; when the angle of attack β1 gradually increases from 90°, δM>0, so that the pitch moment M increases counterclockwise, and the angle of attack β1 is reduced, so α=90° is a stable equilibrium point.

[0087] Therefore, for a stratospheric airship with an approximately elliptical shape, it is stable when it is 90° perpendicular to the longitudinal incoming flow, and it is unstable when the angle between it and the incoming flow is acute.

[0088] For an ellipse, the lateral flow is consistent with the longitudinal flow, and its stability is consistent with the longitudinal stability. When the airflow is lateral and the airflow angle is the sideslip angle β2, the yaw moment M Y When M is positive, it is a counterclockwise torque, which makes the stratospheric airship deviate to the left, which is the stabilizing torque; Y When it is negative, it is a clockwise moment, causing the airship to deviate to the right, which is an unstable moment. Y There are two equilibrium points where the sideslip angle is 0, namely, sideslip angle β2=0° and β2=90°, or sideslip angle β2=180° and β2=270°.

[0089] When the sideslip angle β2 gradually increases from 0°, δM<0, making the yaw moment M Y As the yaw moment M increases clockwise, the sideslip angle β2 continues to increase, so the sideslip angle β2 is an unstable equilibrium point at 0°; when β2 gradually increases from 90°, δM>0, making the yaw moment M Y As it increases counterclockwise, the sideslip angle β2 is reduced, so β2=90° is the stable equilibrium point.

[0090] Therefore, for a stratospheric airship with an approximately elliptical shape, it is in a stable state when it is 90° perpendicular to the lateral flow, and it is in an unstable state when the angle of attack and sideslip angle of the flow are acute.

[0091] It can be seen that for a two-dimensional elliptical airship, it is in a stable state when the axis of the airship is perpendicular to the incoming flow, and it is in an unstable state in all other states.

[0092] Embodiment 2

[0093] In the embodiment of the present invention, the elliptical outer structure is an ellipsoid structure. An ellipsoid is formed by rotating an ellipse around an axis, and the distances from a point on the sphere to the two foci are equal.

[0094] When a uniform flow flows through a stratospheric airship with a simplified ellipsoidal structure at an airflow angle α, it can be considered that the stratospheric airship moves along a principal axis perpendicular to a plane. The turbulent kinetic energy T at any airflow angle can be expressed as formula (10):

[0095]

[0096] Among them, α represents the airflow angle, ρ represents the air density, V ∞ represents the speed of air, represents the volume of the stratospheric airship, k1, k2, k3 represent the longitudinal mass coefficient, transverse mass coefficient and rotational mass coefficient of the additional mass respectively.

[0097] Here, when the flow velocity of the fluid increases to a very high level, the streamlines are no longer clearly discernible, there are many small vortices in the flow field, the laminar flow is destroyed, and there is not only sliding but also mixing between adjacent flow layers. At this time, the fluid moves irregularly, and a component velocity perpendicular to the axis of the flow tube is generated. This kind of movement is called turbulence.

[0098] According to the turbulent kinetic energy, the corresponding formula for the resultant moment M can be obtained (11):

[0099]

[0100] Among them, α represents the airflow angle, ρ represents the air density, V ∞ represents the speed of air, represents the volume of the stratospheric airship, k1, k2, k3 represent the longitudinal mass coefficient, transverse mass coefficient, and rotational mass coefficient of the additional mass, respectively. Assume that one component of the transverse momentum is equal to Then the resultant torque about the axis perpendicular to the direction of motion and momentum is given by formula (12)

[0101]

[0102] When the airflow is longitudinal and the airflow angle is angle of attack β1, since the resultant torque of the stratospheric airship is balanced when the angle of attack β1 = 0° or β1 = 180°, M is 0, and k3 = 0; similarly, when the angle of attack β1 = 90° or β1 = 270°, it is also a balance point. In most practical problems, the motion occurs on the main plane, that is, at right angles to the main axis. Then the entire resultant torque is based on the product of the velocity and the momentum component at right angles to it, and formula (13) can be obtained:

[0103]

[0104] Formula (13) can represent the first correlation between the torque and the airflow angle α.

[0105] For a three-dimensional ellipsoid, the additional mass coefficients, i.e., the longitudinal mass coefficient k1 and the transverse mass coefficient k2, are:

[0106]

[0107] Among them, the semi-major axis of an elliptical cross section in the ellipsoid structure is a, and the semi-minor axis is b. Obviously, the conclusion about the equilibrium point obtained by formula (11) is the same as the two-dimensional theoretical analysis. When the airflow is longitudinal, there are two equilibrium points with zero pitch moment for the stratospheric airship in the flying state, namely, the angle of attack β1 = 0° and β1 = 90°, or the angle of attack β1 = 180° and β1 = 270°. Among them, the angle of attack β1 = 0° is an unstable equilibrium point, and the angle of attack β1 = 90° is a stable equilibrium point.

[0108] For a stratospheric airship with an ellipsoidal structure, the lateral flow and the longitudinal flow have the same motion state, and its stability is consistent with the longitudinal stability. When the airflow is lateral and the airflow angle is the sideslip angle β2, the yaw moment M Y When M is positive, it is a counterclockwise torque, which makes the airship deviate to the left, which is the stabilizing torque; Y When it is negative, it is a clockwise moment, causing the airship to deviate to the right, which is an unstable moment. Y There are two equilibrium points where the sideslip angle is 0, namely, sideslip angle β2=0° and β2=90°, or sideslip angle β2=180° and β2=270°.

[0109] When the sideslip angle β2 gradually increases from 0°, δM<0, making the yaw moment M Y As the angle increases clockwise, the sideslip angle β2 continues to increase, so the sideslip angle β2 is an unstable equilibrium point at 0°; when β2 gradually increases from 90°, δM>0, making the yaw moment M Y As it increases counterclockwise, the sideslip angle β2 is reduced, so β2=90° is the stable equilibrium point.

[0110] Therefore, for a stratospheric airship with an approximately ellipsoidal shape, it is in a stable state when it is 90° perpendicular to the incoming flow, and it is in an unstable state when the angle of attack and sideslip angle of the incoming flow are at other angles.

[0111] The stability assessment method of a stratospheric airship provided by the present invention assesses the stability of the stratospheric airship by combining the elliptical shape structure corresponding to the stratospheric airship with the first correlation relationship between the moment exerted on the stratospheric airship and the airflow angle and the current airflow angle, thereby achieving a quantitative assessment of the stability of the stratospheric airship in a flying state, providing important reference data for the safety and control of the stratospheric airship, and facilitating the safe operation of the stratospheric airship.

[0112] The following is a description of the stability assessment device for a stratospheric airship provided by the present invention. The stability assessment device for a stratospheric airship described below and the stability assessment method for a stratospheric airship described above can be referred to each other.

[0113] like Figure 4 As shown, a stability assessment device for a stratospheric airship provided by an embodiment of the present invention includes:

[0114] The acquisition unit 402 is used to acquire the elliptical shape structure corresponding to the shape of the stratospheric airship.

[0115] The calculation unit 404 is used to obtain a first correlation relationship between the moment acting on the stratospheric airship and the airflow angle according to the parameters of the parameterized model.

[0116] The evaluation unit 406 is used to evaluate the stability of the stratospheric airship according to the current airflow angle and the first correlation relationship.

[0117] Since the tail wing has almost no effect on stability when the stratospheric airship is in a state of floating with the wind, that is, when the airspeed is very low, the tail wing is ignored in the technical solution of the embodiment of the present invention, and the streamlined body of the stratospheric airship is simplified to obtain an elliptical shape structure, and the lift force on the stratospheric airship based on the elliptical shape structure and the airflow is analyzed, and the stability of the stratospheric airship is evaluated according to the analysis results. This solution makes up for the deficiency that the method of obtaining aerodynamic coefficients by linearizing the motion equation in the prior art is only applicable to the stability evaluation of the stratospheric airship, and provides quantitative evaluation data to ensure the safety and control of the floating state of the stratospheric airship, which is of great significance to the flight safety and control of the stratospheric airship.

[0118] The calculation unit 404 is also used to obtain a second correlation between the complex potential of the fluid when it bypasses an obstacle and the parameters of the parameterized model; and obtain a first correlation between the moment exerted on the stratospheric airship and the airflow angle according to the parameters of the parameterized model and the second correlation.

[0119] The evaluation unit 406 is also used to obtain the slope of the torque with respect to the current airflow angle; when the slope is less than 0, it is determined that the current airflow angle is in an increasing process; when the slope is greater than 0, it is determined that the current airflow angle is in a decreasing process.

[0120] Since the functional modules of the device for evaluating stability of a stratospheric airship of the exemplary embodiment of the present invention respectively correspond to the steps of the exemplary embodiment of the method for evaluating stability of a stratospheric airship described above, for details not disclosed in the device embodiment of the present invention, please refer to the embodiment of the method for evaluating stability of a stratospheric airship described above.

[0121] The stability assessment device for a stratospheric airship provided by the present invention assesses the stability of the stratospheric airship by combining the elliptical shape structure corresponding to the stratospheric airship with the first correlation relationship between the moment exerted on the stratospheric airship and the airflow angle and the current airflow angle, thereby achieving a quantitative assessment of the stability of the stratospheric airship in a flying state, providing important reference data for the safety and control of the stratospheric airship, and facilitating the safe operation of the stratospheric airship.

[0122] Figure 5 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 5 As shown, the electronic device may include: a processor 510, a communication interface 520, a memory 530 and a communication bus 540, wherein the processor 510, the communication interface 520 and the memory 530 communicate with each other through the communication bus 540. The processor 510 may call the logic instructions in the memory 530 to execute the stability evaluation method of the stratospheric airship, the method comprising: obtaining a parameterized model of the elliptical shape structure of the stratospheric airship; obtaining a first correlation relationship between the moment and the airflow angle of the stratospheric airship in the flying state according to the parameters of the parameterized model; and evaluating the stability of the stratospheric airship according to the current airflow angle and the moment formula.

[0123] In addition, the logic instructions in the above-mentioned memory 530 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0124] On the other hand, the present invention further provides a computer program product, the computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, and when the program instructions are executed by a computer, the computer can execute the stability assessment method of a stratospheric airship provided by the above methods, the method comprising: obtaining a parameterized model of an elliptical shape structure of a stratospheric airship; obtaining a first correlation between a torque exerted on the stratospheric airship in a flying state and the airflow angle according to parameters of the parameterized model; and assessing the stability of the stratospheric airship according to a current airflow angle and the torque formula.

[0125] On the other hand, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented when the computer program is executed by a processor to perform the above-mentioned stratospheric airship stability assessment method, the method comprising: obtaining a parameterized model of the elliptical shape structure of the stratospheric airship; obtaining a first correlation relationship between the torque exerted on the stratospheric airship in a floating state and the airflow angle according to the parameters of the parameterized model; and assessing the stability of the stratospheric airship according to the current airflow angle and the torque formula.

[0126] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0127] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for evaluating the stability of a stratospheric airship, characterized in that: The stability assessment method comprises: Obtaining a parameterized model of the elliptical shape structure of a stratospheric airship; Obtaining a first correlation relationship between the moment and the airflow angle of the stratospheric airship in the flying state according to the parameters of the parameterized model; evaluating the stability of the stratospheric airship according to the current airflow angle and the first correlation relationship; The elliptical shape structure includes an elliptical plane structure; Obtaining a first correlation relationship between the moment exerted on the stratospheric airship in the flying state and the airflow angle according to the parameters of the parameterized model includes: Acquire a second correlation between the complex potential of the fluid when it bypasses an obstacle and the parameters of the parameterized model; Obtaining a first correlation relationship between the moment acting on the stratospheric airship and the airflow angle according to the parameters of the parameterized model and the second correlation relationship; The first association relationship includes: Where ρ is the air density, V ∞ is the far-field velocity, a and b are the semi-major axis and semi-minor axis of the ellipse of the elliptical plane structure, and α is the airflow angle; The first association relationship also includes: Among them, V ∞ is the far-field velocity, ρ is the air density, a and b are the semi-major axis and semi-minor axis of the ellipse of the ellipsoid structure, and α is the airflow angle.

2. The stability evaluation method according to claim 1, characterized in that: The step of evaluating the stability of the stratospheric airship according to the current airflow angle and the first correlation relationship includes: Obtaining the slope of the moment with respect to the current airflow angle; When the slope is less than 0, determining that the current airflow angle is in an increasing process; When the slope is greater than 0, it is determined that the current airflow angle is in a decreasing process.

3. The stability evaluation method according to claim 1, characterized in that: The elliptical outer structure includes an ellipsoid structure or an ellipsoid-like spiral structure.

4. A stability assessment device for a stratospheric airship, characterized in that: The stability assessment device comprises: An acquisition unit, used for acquiring a parameterized model of the elliptical shape structure of the stratospheric airship; A calculation unit, configured to obtain a first correlation between the moment acting on the stratospheric airship and the airflow angle according to the parameters of the parameterized model; an evaluation unit, configured to evaluate the stability of the stratospheric airship according to the current airflow angle and the first association relationship; The elliptical shape structure includes an elliptical plane structure; Obtaining a first correlation relationship between the moment exerted on the stratospheric airship in the flying state and the airflow angle according to the parameters of the parameterized model includes: Acquire a second correlation between the complex potential of the fluid when it bypasses an obstacle and the parameters of the parameterized model; Obtaining a first correlation relationship between the moment acting on the stratospheric airship and the airflow angle according to the parameters of the parameterized model and the second correlation relationship; The first association relationship includes: Where ρ is the air density, V ∞ is the far-field velocity, a and b are the semi-major axis and semi-minor axis of the ellipse of the elliptical plane structure, and α is the airflow angle; The first association relationship also includes: Among them, V ∞ is the far-field velocity, ρ is the air density, a and b are the semi-major axis and semi-minor axis of the ellipse of the ellipsoid structure, and α is the airflow angle.

5. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the method for evaluating the stability of a stratospheric airship according to any one of claims 1 to 3 are implemented.

6. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for evaluating the stability of a stratospheric airship according to any one of claims 1 to 3 are implemented.

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