CN115270313A - Umbrella-machine combination modeling method, device, server and storage medium - Google Patents

Abstract

The present application discloses a modeling method, device, server and storage medium for an umbrella-machine combination. Including: obtaining the first initial condition of the parachute, the second initial condition of the UAV, and the initial state quantity of the umbrella-aircraft assembly; cyclically executing the modeling and simulation steps until the simulation results of the umbrella-aircraft assembly model are consistent with the preset motion law The modeling and simulation steps include: establishing the parachute dynamics equation based on the first initial condition of the parachute; establishing the parachute six-degree-of-freedom model based on the parachute dynamics equation; establishing the six-degree-of-freedom model of the UAV based on the second initial condition of the UAV degree model; establish the dynamic equation of the suspension system as a constraint model; obtain the parachute-aircraft combination model based on the parachute, UAV six-degree-of-freedom model and constraint model; The combined model is simulated. The present invention can carry out the modeling of the umbrella-aircraft assembly through a suitable and accurate modeling method.

Description

A modeling method, device, server and storage medium for an umbrella-aircraft combination

technical field

The present application relates to the technical field of parachute UAV modeling, and in particular to a modeling method, device, server and storage medium for an parachute-aircraft combination.

Background technique

With the development of drone technology, the application range of drones is becoming wider and wider. For example, in terms of military use, drones can be used as aerial reconnaissance platforms and weapon platforms to perform various tasks such as reconnaissance, attack, blockade, interference, relay, and damage assessment. In terms of civilian use, UAVs can be used for aerial photography, weather detection, terrain mapping, and emergency rescue and disaster relief.

The combat radius and cruising time of drones are usually limited by factors such as their size and fuel. In order to increase the effective combat radius and cruising time of UAVs, small UAVs that are delivered to target areas through delivery platforms have emerged as the times require. At present, the main application launch platforms include various types of artillery, rockets and large aircraft. In order to adapt to various delivery environments, small UAVs are often transported over the target area in the form of projectiles and carrying boxes, and then become UAVs to perform predetermined tasks. Due to the influence of the launch platform, the initial working state of the UAV during the launch process has great uncertainty, so it is impossible to establish a reference motion state like a conventional aircraft. In order to make this type of drop drone enter a controllable flight state, a method of using a parachute to stabilize the drone, that is, a parachute drone is proposed.

The specific release process of the parachute drone is as follows: First, the small drone is placed in a protective cover in the form of a projectile and hangs under the parachute to be dropped into a free fall. Then the parachute opens, and the small UAV decelerates and spins under the action of the parachute in the form of a projectile, and falls vertically. Afterwards, when the falling speed of the small UAV is stable and the rotational speed is reduced to a certain range, the small UAV changes from the shape of a projectile to the shape of a UAV with a conventional layout under the action of the wing and tail expansion mechanism. The nose of the small drone points to the ground and falls at a constant speed under the action of a parachute. Finally, the parachute UAV throws off the parachute, and the small UAV dives downward. The automatic control system changes the small UAV from the state of downward dive to the state of level flight, and is ready to perform the flight mission.

In order to accurately simulate the movement of the parachute-UAV delivery system of parachute UAVs and provide a theoretical basis for the subsequent UAVs to enter a controllable state, it is necessary to model the parachute-aircraft combination during the UAV delivery process. At present, the relevant modeling researches are mainly concentrated in the field of manned spaceflight missions. Specifically, most of the researches are on the dynamic modeling of the parachute-return capsule system, and the main research is on the parachute opening process of large parachutes and related issues of parachute technology. . However, the structure of the large-scale parachute system is complex and the working procedures are various, and the inflation time is long, so it is not completely suitable for the parachute-UAV delivery system. Moreover, when the UAV turns into a UAV with a conventional layout during the launch process, the wings and tail need to be deployed, and these steps are not required for the return capsule, so the modeling method of the parachute-return capsule system cannot be applied to the parachute-no Motion of man-machine systems. At present, there is no suitable and accurate modeling method for modeling the umbrella-aircraft combination during the UAV launch process.

Contents of the invention

The embodiment of the present application provides a modeling method, device, server, and storage medium of an umbrella-aircraft combination, which can solve the problem that there is no suitable and accurate method for modeling the umbrella-aircraft combination in the process of launching a parachute UAV. The model method is used to accurately simulate the movement of the parachute-UAV delivery system of the parachute UAV, and provide a theoretical basis for the follow-up UAV to enter a controllable state.

In a first aspect, an embodiment of the present invention provides a modeling method for an umbrella-aircraft combination, including:

Obtain the first initial condition of the parachute, the second initial condition of the UAV, and the initial state quantity of the parachute-aircraft combination;

The modeling and simulation steps are executed cyclically until the simulation result of the umbrella-aircraft combination model matches the preset motion law; wherein, the umbrella-aircraft combination includes the parachute and the unmanned aerial vehicle connected by a suspension system;

Wherein, the modeling and simulation steps include:

Based on the first initial condition of the parachute, the dynamic equation of the parachute is established under the parachute body coordinate system;

Based on the dynamic equation of the parachute, a parachute six-degree-of-freedom model is established;

Based on the second initial condition of the unmanned aerial vehicle, a six-degree-of-freedom model of the unmanned aerial vehicle is established under the unmanned aerial vehicle body coordinate system;

Establish the dynamic equation of the suspension system as a constraint model;

Based on the parachute six-degree-of-freedom model, the UAV six-degree-of-freedom model and the constraint model, an umbrella-aircraft composite model is obtained;

The parachute-aircraft combination model is simulated based on the initial state quantities of the umbrella-aircraft combination.

With reference to the first aspect, in a possible implementation manner, the establishment of a dynamic equation of the parachute in the parachute body coordinate system based on the first initial condition of the parachute includes:

calculating a generalized mass matrix of the parachute based on the first initial conditions;

In the parachute body coordinate system, establish the first resultant force and the first resultant moment equation that the parachute is subjected to, the first resultant force includes the binding force F _c1 of the parachute at the cross-connection point of the suspension system, and the The first resultant moment includes the binding moment M _c1 of the parachute at the intersection point;

According to the generalized mass matrix of the parachute, the first resultant force and the first resultant moment equation, the dynamic equation of the parachute in the parachute body coordinate system is established.

With reference to the first aspect, in a possible implementation, the calculating the generalized mass matrix of the parachute based on the first initial condition includes:

Obtain the additional mass of the parachute based on the additional mass coefficient, the atmospheric density, the characteristic volume of the parachute and the moment of inertia generated by displacing part of the gas, and obtain the additional mass matrix of the parachute;

calculating a generalized inertia matrix for the parachute;

determining a generalized mass matrix of the parachute; wherein, the generalized mass matrix is the sum of the additional mass matrix and the generalized inertia matrix.

In combination with the first aspect, in a possible implementation manner, based on the second initial condition of the drone, a six-degree-of-freedom model of the drone is established in the drone body coordinate system, including:

In the UAV body coordinate system, respectively establish the second resultant force and the second resultant moment equation received in the folded state of the UAV, and the third resultant force and the third resultant moment equation received in the unfolded state, the second Both the resultant force and the third resultant force include the restraining force F _c2 of the connecting point of the suspension system on the UAV, and the second resultant moment and the third resultant moment include the restraining moment of the connecting point on the UAV M _c2 ;

A dynamic equation of the unmanned aerial vehicle is established, and a six-degree-of-freedom model of the unmanned aerial vehicle is established based on the dynamic equation of the unmanned aerial vehicle.

In combination with the first aspect, in a possible implementation manner, based on the UAV kinematics model and the mutual mapping relationship between the UAV body coordinate system and the parachute body coordinate system, the parachute kinematic equation is obtained;

The umbrella-aircraft combination model includes the UAV kinematics model and the parachute kinematics model.

With reference to the first aspect, in a possible implementation manner, the establishment of the dynamic equation of the suspension system includes:

The cross-connection point of the suspension system is analyzed by the balance point method, and the dynamic model of the suspension system is established based on the fact that the resultant force on the cross-connection point is zero.

With reference to the first aspect, in a possible implementation manner, the dynamic equation of the suspension system is also obtained based on the number of paracords, the number of suspenders, and the position vector of the connection point.

In a second aspect, another embodiment of the present invention provides a modeling device for an umbrella-aircraft combination, including:

Obtaining module, for obtaining the first initial condition of parachute, the second initial condition of unmanned aerial vehicle and the initial state quantity of parachute-aircraft assembly;

The execution module is used to perform the modeling and simulation steps cyclically until the simulation result of the umbrella-aircraft combination model conforms to the preset motion law; wherein, the umbrella-aircraft combination includes the parachute and the parachute connected through the suspension system. UAV;

Wherein, the execution module includes:

The first establishment sub-module is used to establish the dynamic equation of the parachute in the parachute body coordinate system based on the first initial condition of the parachute;

The second establishes a submodule, which is used to establish a parachute six-degree-of-freedom model based on the dynamic equation of the parachute;

The third establishment sub-module is used to establish a six-degree-of-freedom model of the UAV in the UAV body coordinate system based on the second initial condition of the UAV;

The fourth establishment sub-module is used to establish the dynamic equation of the suspension system as a constraint model;

Obtaining a sub-module for obtaining an umbrella-aircraft combination model based on the parachute six-degree-of-freedom model, the UAV six-degree-of-freedom model and the constraint model;

The simulation sub-module is used for simulating the umbrella-aircraft combination model based on the initial state quantity of the umbrella-aircraft combination.

In a third aspect, another embodiment of the present invention provides a server, including: a memory and a processor;

The memory is used to store program instructions;

The processor is used to execute program instructions in the server, so that the server executes the modeling method of the umbrella-aircraft combination described in any one of the above.

In a fourth aspect, another embodiment of the present invention provides a computer-readable storage medium, the computer-readable storage medium stores executable instructions, and when the computer executes the executable instructions, it can realize any of the above-mentioned Modeling method of umbrella-aircraft combination.

One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

The modeling method of the umbrella-machine combination provided by the embodiment of the present invention includes: obtaining the first initial condition of the parachute, the second initial condition of the UAV, and the initial state quantity of the umbrella-machine combination. The modeling and simulation steps are executed cyclically until the simulation results of the umbrella-aircraft combination model are consistent with the preset motion laws. Wherein, the parachute-aircraft combination includes a parachute and an unmanned aerial vehicle connected by a suspension system. Wherein, the modeling and simulating step includes: establishing a dynamic equation of the parachute in the parachute body coordinate system based on the first initial condition of the parachute. Based on the dynamic equation of the parachute, a six-degree-of-freedom model of the parachute is established. Based on the second initial condition of the UAV, a six-degree-of-freedom model of the UAV is established in the UAV body coordinate system. Establish the dynamic equation of the suspension system as a constraint model. Based on the six-degree-of-freedom model of the parachute, the six-degree-of-freedom model of the UAV and the constraint model, the parachute-aircraft combination model is obtained. The parachute-aircraft combination model is simulated based on the initial state quantities of the umbrella-aircraft combination.

The parachute-aircraft combination modeling method provided by the embodiment of the present invention uses a six-degree-of-freedom model to model the parachute and the UAV, which can not only simulate and analyze the motion of the center of mass during the UAV parachuting process, but also Simulate and evaluate the attitude of the parachute and UAV, as well as the force of the parachute strap, which improves the accuracy of the modeling model. The constraint model for building the parachute-aircraft combination includes the two stages of the UAV's wings being folded and wings being deployed during the real launch process, which more realistically simulates the drone's access control from launch to throwing down the parachute The previous movement process provides data support for the subsequent control of the UAV, reduces the number of physical tests, and saves design and development costs. The embodiment of the present invention realizes the modeling of the parachute-aircraft combination through a suitable and accurate modeling method in the parachute UAV delivery process, so as to accurately simulate the movement of the parachute-UAV delivery system of the parachute UAV , to provide a theoretical basis for the follow-up UAV to enter the controllable state.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings that need to be used in the description of the embodiments of the present invention. Obviously, the drawings in the following description are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings without creative effort.

Fig. 1 is the flowchart of the modeling method of the umbrella-aircraft combination that the embodiment of the present application provides;

Fig. 2 is the schematic structural view of the modeling device of the umbrella-aircraft combination provided by the embodiment of the present application;

FIG. 3 is a schematic structural diagram of an execution module provided by an embodiment of the present application;

Fig. 4 is a schematic diagram of the coordinate system of the umbrella-aircraft combination provided by the embodiment of the present application;

Fig. 5 is the schematic diagram of the umbrella-aircraft combination under the unmanned aerial vehicle wing expansion state that the embodiment of the present application provides;

Fig. 6 is a schematic diagram of the umbrella-aircraft combination in the folded state of the drone's wings provided by the embodiment of the present application;

Fig. 7 is a schematic diagram of longitudinal force analysis of the umbrella-aircraft combination parachute process provided by the embodiment of the present application;

Fig. 8 is the UAV pitch angle change curve provided by the embodiment of the present application;

Fig. 9 is the parachute pitch angle change curve provided by the embodiment of the present application;

Fig. 10 is the total tension variation curve of the sling provided by the embodiment of the present application;

Fig. 11 is the three-way speed change curve of the drone provided by the embodiment of the present application.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Apparently, the described embodiments are some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Please refer to Fig. 1, the embodiment of the present invention provides a modeling method of an umbrella-machine assembly, including steps 101 to 102:

Among them, the parachute-aircraft combination refers to the combination of a parachute and a flying device, as shown in Figures 4 to 6, including a connected parachute 1 and a UAV 2 (as shown in Fig. The schematic diagram of the parachute-aircraft combination, wing 21 is in unfolded state). The parachute 1 includes a canopy 11, a parachute 12 and a strap 13, and C _m represents the center of mass of the parachute.

The modeling method of the umbrella-aircraft combination provided by the embodiment of the present invention simplifies the conditions before modeling, including:

For the dynamic modeling of the fully-expanded parachute, the following simplified assumptions are made:

1) The parachute is a rigid body with six degrees of freedom. During inflation, the shape of the canopy is regarded as a combination of a hemisphere and a truncated cone. The elastic deformation of the parachute is ignored, and the shape of the canopy is fixed in the stable descent stage after it is full. 2) The canopy centroid is fixed relative to the bottom edge during the inflation process, that is, the canopy centroid position does not change during the inflation process and coincides with the aerodynamic pressure center. 3) The fluid additional force and additional moment generated by the unsteady motion of the parachute are represented by additional mass. 4) The sling is a linear elastic material and can only withstand tensile deformation. 5) The wake of the suspended UAV has negligible influence on the parachute. 6) Planar earth assumption.

Step 101: Obtain the first initial condition of the parachute, the second initial condition of the UAV, and the initial state quantity of the parachute-aircraft combination.

伞衣投影直径D_p，降落伞的轴向力系数C_T，平衡攻角为0时的降落伞轴向力系数C_T0，降落伞轴向力系数对攻角的参数C_Tα，降落伞的法向力系数C _N ，降落伞法向力系数对攻角的参数C_Nα，降落伞攻角α，吊带的弹性模量E_BA，吊带的初始长度L _A ，伞绳的弹性模量E_BO，伞绳的初始长度L ₀ 。Among them, the first initial condition of the parachute includes the parameters of the parachute: the mass of the canopy of the parachute m _c , the mass of the string of the parachute m _s , the mass of the strap of the parachute m _r , the additional mass coefficients k _ii and k _jj , in the parachute body coordinate system The aerodynamic damping coefficient m _dx in the X-axis direction of the parachute, the aerodynamic damping coefficient m _dy in the Y-axis direction of the parachute body coordinate system, the aerodynamic damping coefficient m _dz in the Z-axis direction of the parachute body coordinate system, and the parachute centroid C _m The distance d _c to the origin O ₁ of the parachute body coordinate system, the moment of inertia of the parachute around the three coordinate axes of the parachute body coordinate system

Canopy projection diameter D _p , parachute axial force coefficient C _T , parachute axial force coefficient C _T0 when the equilibrium angle of attack is 0, parachute axial force coefficient versus attack angle parameter C _Tα , parachute normal force coefficient C _N , parachute normal force coefficient versus angle of attack parameter C _Nα , parachute angle of attack α, elastic modulus E _BA of the harness, initial length of the harness L _A , elastic modulus of the parachute E _BO , initial length of the parachute L ₀ .

The second initial conditions of the UAV include: aerodynamic lift coefficient C _L , drag coefficient C _D , lateral force coefficient C _y , pitch moment coefficient C _m , roll moment coefficient C _l , yaw moment Coefficient C _n , mass, moment of inertia of UAV in unfolded state, reference chord length C _A of UAV, reference span length b of wing, reference area of wing S _w , UAV in unfolded state The position vector ρ _c3 of the center of mass in the UAV body coordinate system, where ρ _c3 is obtained by calculation, and the rest are known quantities. Moment of inertia in the folded state of the UAV, drag area S _D , drag coefficient C _Dz , drag moment coefficient C _Mz , distance d _z from the aerodynamic focus to the center of gravity, and the center of mass of the UAV in the UAV body coordinate system in the folded state The position vector ρ _c2 of , where ρ _c2 is obtained by calculation, and the rest are known quantities.

The initial state of the umbrella-aircraft combination: obtained by assignment, for example, the initial position [0, 0, -8000], the initial velocity [238, 0, 0], the initial attitude [0 -60/57.3 0].

Step 102: cyclically execute the modeling and simulation steps.

Wherein, the modeling simulation step includes step 1021 ~ step 1026:

Step 1021: Based on the first initial condition of the parachute, establish the dynamic equation of the parachute in the parachute body coordinate system.

Further, step 1021 includes steps 10211 to 10213.

Step 10211: Calculate the generalized mass matrix of the parachute based on the first initial condition.

Step 10211 includes Step 102111~Step 102113.

Step 102111: Obtain the additional mass of the parachute based on the additional mass coefficient, the atmospheric density, the characteristic volume of the parachute and the moment of inertia generated by displacing part of the gas, and obtain the additional mass matrix of the parachute.

In practice, the additional mass is calculated by the volume of the canopy, and the additional mass of the parachute is divided into two parts: the internal mass and the apparent mass. The additional mass matrix is a 6×6 symmetric matrix with 21 independent components. The parachute studied in this application is a typical axisymmetric body with 4 non-zero and independent additional masses, namely α ₁₁ , α ₂₂ =α ₃₃ , α ₅₅ =α ₆₆ , α ₂₆ =-α ₃₅ , relevant experiments show , when the origin of the parachute body coordinate system coincides with the pressure center of the canopy, the additional mass component α ₂₆ =-α ₃₅ =0, so only three additional mass components need to be determined α ₁₁ , α ₂₂ =α ₃₃ , α ₅₅ =α _66. Generally, the additional mass of the parachute is calculated according to the following formula:

表示特征体积（此处计算时采用伞衣内部容积，即充完气后半球状伞衣的半球体积），

表示排开部分气体产生的转动惯量，即在伞衣表面受到外界压力下伞衣内部排开部分气体后产生的转动惯量。Among them, α _ii represents the mass part in the mass matrix, α _jj represents the moment of inertia part in the mass matrix, k _ii and k _jj both represent the additional mass coefficient, and the size is the sum of the internal mass and apparent mass and the internal mass Ratio, ρ represents the atmospheric density,

Represents the characteristic volume (the internal volume of the canopy is used in the calculation here, that is, the hemispherical volume of the hemispherical canopy after inflating),

Indicates the moment of inertia generated by the discharge of part of the gas, that is, the moment of inertia generated after part of the gas is discharged inside the canopy when the surface of the canopy is subjected to external pressure.

可以表示为特征体积

与投影直径的关系式：

can be expressed as the characteristic volume

The relationship with projected diameter:

Wherein, D _p represents the projected diameter of the canopy, that is, the diameter of the plane of the hemispherical canopy filled with air. The additional mass matrix Φ _F of the parachute is obtained as:

Step 102112: Calculate the generalized inertia matrix Φ _B1 of the parachute.

Among them, d _c represents the distance from the parachute centroid C _m to the origin O ₁ of the parachute body coordinate system, m _p represents the mass of the parachute, I _X1X1 , I _Y1Y1 , and I _Z1Z1 represent the moments of inertia of the parachute around the three coordinate axes of the parachute body coordinate system ( I _X1X1 , I _Y1Y1 , and I _Z1Z1 are known quantities, provided by parachute manufacturers).

Step 102113: Determine the generalized mass matrix of the parachute; wherein, the generalized mass matrix is the sum of the additional mass matrix and the generalized inertia matrix.

Calculate the generalized mass matrix Φ1 _of the parachute as:

Step 10212: In the parachute body coordinate system, establish the first resultant force and the first resultant moment equation on the parachute, the first resultant force includes the binding force F _c1 of the parachute at the connection point of the suspension system, and the first resultant moment includes the connection point Point to the restraining moment M _c1 of the parachute.

Wherein, establishing the first resultant force and the first resultant moment equation on the parachute specifically includes the following steps.

Taking the geometric center of the canopy as the origin, a parachute body coordinate system is established. Specifically, as shown in Figure 4, taking the geometric center position O ₁ of the canopy as the origin, pointing along the canopy symmetry axis to the intersection of the parachute lines is the O ₁ X ₁ axis, and the directions of the O ₁ Y ₁ axis and the O ₁ Z ₁ axis are based on The initial conditions are determined. Specifically, the parachute UAV is sometimes thrown obliquely, sometimes it is thrown straight, and the O ₁ Y ₁ axis and O ₁ Z ₁ are determined according to the initial throwing position of the parachute UAV. axis direction, and form a right-handed coordinate system with the O ₁ X ₁ axis, and establish the parachute body coordinate system O ₁ X ₁ Y ₁ Z ₁ .

In addition, continue to refer to Figure 4, with the paracord intersection point O ₃ as the origin, the O ₃ X ₃ axis points to the other end of the sling along the direction of the stretched sling, and the O ₃ Y ₃ -axis and O ₃ Z ₃ -axis directions are based on the initial conditions Make sure, form the right-handed coordinate system together with the O ₃ X ₃ axis, and establish the body coordinate system O ₃ X ₃ Y ₃ Z ₃ of the hanging system. In Figure 4, the geodetic coordinate system O _E X _E Y _E Z _E adopts the local north sky east coordinate system, and the directions of O _E X _E axis, O _E Y _E axis and O _E Z _E axis point to the local north, sky, and east respectively . The geodetic coordinate system is a right-handed coordinate system.

Any two coordinate systems in the parachute body coordinate system O ₁ X ₁ Y ₁ Z ₁ , the suspension system body coordinate system O ₃ X ₃ Y ₃ Z ₃ and the earth coordinate system O _E X _E Y _E Z _E can be circled. The coordinate axes are rotated by the corresponding Euler angles for mutual conversion.

In practice, the parachute will be affected by gravity, aerodynamic force and strap restraint force during the movement process. In the parachute body coordinate system, the first resultant force and first resultant moment of the parachute are calculated according to the following formula:

Among them, F ₁ represents the first resultant force received by the parachute, M ₁ represents the first resultant moment received by the parachute, G ₁ represents the gravity of the parachute, F _a1 represents the aerodynamic force of the parachute, F _c1 represents the connecting point of the parachute suspension system The constraint force on the parachute, M _c1 represents the constraint moment on the parachute at the intersection point (the constraint force F _c1 and the constraint moment M _c1 are given by the constraint equation, which need to be coupled with the dynamic equation of the UAV to solve, specifically, the parachute and no The balance point method is used at the man-machine connection to build a constraint model, and then the constraint force F _c1 and the constraint moment M _c1 are respectively introduced into the six-degree-of-freedom model of the UAV and the parachute itself, so that during each step of the simulation movement, the connection The point is in a state of static equilibrium to solve the constraint force F _c1 and constraint moment M _c1 , and then substitute the constraint force F _c1 and constraint moment M _c1 into their respective six-degree-of-freedom models to determine the motion state of the entire system.) ρ _c1 expresses The position vector of the parachute centroid in the parachute body coordinate system (determined by the distance d _c from the parachute centroid C _m to the origin O ₁ of the parachute body coordinate system), M _d1 represents the aerodynamic damping matrix of the parachute.

The calculation expression of the aerodynamic force F _a1 of the parachute in the parachute body coordinate system is:

Among them, X _s represents the component of F _a1 in the X-axis direction of the parachute body coordinate system, Y _s represents the component of F _a1 in the Y-axis direction of the parachute body coordinate system, Z _s represents the Z of F _a1 in the parachute body coordinate system ρ represents the density of the atmosphere, V _c represents the parachute's crush speed, V _cx represents the component of the parachute's crush speed V _c along the X axis in the parachute body coordinate system, V _cy represents the parachute's crush speed The component of V _c along the Y axis in the parachute body coordinate system ( V _c , V _cx , V _cy are output by the dynamic equation of the parachute established by the Newton-Euler equation), C _N represents the normal force coefficient of the parachute, C _T represents the axial force coefficient of the parachute, and A ₀ represents the nominal area of the canopy, that is, the area of the windward side of the canopy, which is given by assigning a value to the first initial condition.

The normal force coefficient C _N and the axial force coefficient C _T express the quadratic equation with the parachute angle of attack α as the independent variable:

表示降落伞法向力系数对攻角的参数，

表示平衡攻角为0时的降落伞轴向力系数，

表示降落伞轴向力系数对攻角的参数，

均通过给第一初始条件赋值给定，

表示降落伞的平衡攻角（降落伞的平衡攻角

为降落伞自身的特征参数，由降落伞厂家提供或通过风洞试验得到），降落伞攻角

的计算模型为：in,

is the parameter representing the parachute normal force coefficient against the angle of attack,

Indicates the axial force coefficient of the parachute when the equilibrium angle of attack is 0,

represents the parameter of the parachute axial force coefficient against the angle of attack,

are given by assigning values to the first initial conditions,

Indicates the equilibrium angle of attack of the parachute (the equilibrium angle of attack of the parachute

is the characteristic parameter of the parachute itself, provided by the parachute manufacturer or obtained through wind tunnel tests), the parachute angle of attack

The calculation model is:

Among them, V _cx represents the component of the parachute's crest velocity V _c along the X axis in the parachute body coordinate system, V _cy represents the component of the parachute's crest velocity V _c along the Y axis in the parachute body coordinate system, and V _cz represents the parachute The components of the pressure center velocity V _c along the Z axis in the parachute body coordinate system ( V _c , V _cx , V _cy , V _cz are output by the parachute dynamic equation established by the Newton-Euler equation).

The component expression of the aerodynamic damping matrix M _d1 of the parachute in the parachute body coordinate system is:

，其中，

为大气密度，V _c 表示降落伞的压心速度），L表示降落伞的特征长度（降落伞的固有特性，为已知量），S表示降落伞的特征面积（降落伞的固有特性，为已知量），V _Cm 表示降落伞的质心速度，ω _x 表示降落伞的角速度在降落伞体坐标系中X轴方向上的分量，ω _y 表示降落伞的角速度在降落伞体坐标系中Y轴方向上的分量，ω _z 表示降落伞的角速度在降落伞体坐标系中Z轴方向上的分量。Among them, M _dx represents the component of M _d1 in the X-axis direction of the parachute body coordinate system, M _dy represents the component of M _d1 in the Y-axis direction of the parachute body coordinate system, and M _dz represents the Z of M _d1 in the parachute body coordinate system The component on the axis direction, m _dx represents the aerodynamic damping coefficient in the X-axis direction of the parachute body coordinate system, m _dy represents the aerodynamic damping coefficient in the Y-axis direction of the parachute body coordinate system, m _dz represents the aerodynamic damping coefficient in the parachute body coordinate system The aerodynamic damping coefficient in the Z-axis direction ( m _dx , m _dy , m _dz are the parachute's own damping parameters, which are known quantities), and q is the dynamic pressure (

,in,

is the atmospheric density, V _c represents the parachute pressure center velocity), L represents the characteristic length of the parachute (the inherent characteristic of the parachute, which is a known quantity), S represents the characteristic area of the parachute (the inherent characteristic of the parachute, which is a known quantity), V _Cm represents the velocity of the center of mass of the parachute, ω _x represents the component of the parachute's angular velocity in the X-axis direction in the parachute body coordinate system, ω _y represents the component of the parachute's angular velocity in the Y-axis direction in the parachute body coordinate system, ω _z represents the parachute The component of the angular velocity in the Z-axis direction in the parachute body coordinate system.

The mass center velocity V _Cm of the parachute is expressed as:

In the above formula,

Among them, V _cx represents the component of the parachute's crest velocity V _c along the X axis in the parachute body coordinate system, V _cy represents the component of the parachute's crest velocity V _c along the Y axis in the parachute body coordinate system, and V _cz represents the parachute The components of the pressure center velocity V _c along the Z axis in the parachute body coordinate system ( V _c , V _cx , V _cy , V _cz are output by the dynamic equation of the parachute established by the Newton-Euler equation), as shown in Figure 4 d _c represents the distance between the parachute centroid C _m and the origin O ₁ of the parachute body coordinate system.

Step 10213: According to the generalized mass matrix of the parachute, the first resultant force and the first resultant moment equation, establish the dynamic equation of the parachute in the parachute body coordinate system.

建立降落伞的动力学方程。Among them, through the Newton-Euler equation of the spinor form of the rigid body moving in the ideal fluid

Establish the dynamic equation of the parachute.

The kinetic equation of the inflated parachute can be expressed as:

分别是降落伞所受的外力和外力矩在降落伞体坐标系中的分量；

分别是降落伞的速度和角速度在降落伞体坐标系中的分量；

分别是降落伞的加速度和角加速度在降落伞体坐标系中的分量；

表示降落伞质心C_m到降落伞体坐标系原点O₁的距离；

分别表示降落伞绕降落伞体坐标系的三个坐标轴的转动惯量。

分别表示降落伞附加质量的5个分量；

分别表示降落伞充气过程中附加质量5个分量的变化率。Among them, m _p represents the total mass of the parachute, m _p = m _c + m _s + m _r , m _c represents the mass of the canopy, m _s represents the mass of the parachute, and m _r represents the mass of the sling;

are the components of the external force and external moment on the parachute in the coordinate system of the parachute body;

are the components of the velocity and angular velocity of the parachute in the parachute body coordinate system;

are the components of the acceleration and angular acceleration of the parachute in the parachute body coordinate system;

Indicates the distance from the parachute centroid C _m to the origin O ₁ of the parachute body coordinate system;

Respectively represent the moment of inertia of the parachute around the three coordinate axes of the parachute body coordinate system.

represent the 5 components of the additional mass of the parachute respectively;

Respectively represent the rate of change of the five components of the added mass during the inflation process of the parachute.

Step 1022: Based on the dynamic equation of the parachute, a six-degree-of-freedom model of the parachute is established.

In practice, the six-degree-of-freedom model of the parachute also needs to be established through the first weight, the first moment of inertia, the first resultant force, and the first resultant moment of the parachute.

Among them, the first moment of inertia of the parachute is represented by the moments of inertia of the three parts of the canopy, parachute and harness:

Among them, I represents the first moment of inertia of the parachute, I _cx represents the moment of inertia of the canopy around the X axis, I _sx represents the moment of inertia of the parachute around the X axis, I _rx represents the moment of inertia of the sling around the X axis, I _cy represents the moment of inertia of the parachute The moment of inertia of the clothing around the Y axis, I _sy represents the moment of inertia of the parachute around the Y axis, I _ry represents the moment of inertia of the sling around the Y axis, I _cz represents the moment of inertia of the canopy around the Z axis, I _sz represents the moment of inertia of the parachute around the Z axis The moment of inertia of the axis, I _rz represents the moment of inertia of the sling around the Z axis, I _cx , I _sx , I _rx , I _cy , I _sy , I _ry , I _cz , I _sz , and I _rz are the characteristic values of the parachute itself , is a known quantity.

Step 1023: Based on the second initial condition of the drone, a six-degree-of-freedom model of the drone is established in the body coordinate system of the drone.

Step 1023 includes step 10231~step 10232.

Step 10231: In the UAV body coordinate system, respectively establish the second resultant force and second resultant moment equation received by the UAV in the folded state, and the third resultant force and third resultant moment equation received by the UAV in the unfolded state, and the second resultant force Both the second resultant moment and the third _{resultant moment include the binding moment M c2} of _the connecting point to the UAV .

Specifically, the UAV body coordinate system is established with the center of mass of the UAV as the origin. As shown in Figure 4, with the center of mass of the UAV as the origin, the O 3 X 3 axis parallel to the longitudinal symmetry axis of the UAV and pointing to the bottom of the UAV is the O ₃ X ₃ axis, and the O ₃ Y ₃ axis is located in the longitudinal symmetry plane, O ₃ Z _{The 3} axis is perpendicular to the longitudinal symmetry plane, and the O ₃ X ₃ , O ₃ Y ₃ and O ₃ Z ₃ coordinate axes together form a right-handed coordinate system, and the UAV body coordinate system O ₃ X ₃ Y ₃ Z ₃ is established.

Parachute body coordinate system O ₁ X ₁ Y ₁ Z ₁ , drone body coordinate system O ₃ X ₃ Y ₃ Z ₃ , suspension system body coordinate system O ₃ X ₃ Y ₃ Z ₃ and earth coordinate system O _E X _E Y Between any two coordinate systems in _E Z _E , the corresponding Euler angle can be rotated around the coordinate axis for mutual conversion.

In practice, the UAV will be affected by gravity, aerodynamic resistance and sling restraint in the folded state, and will be affected by gravity, aerodynamic force and sling restraint in the unfolded state of the UAV wings. In the UAV body coordinate system Next, calculate the second resultant force and second resultant moment in the folded state of the UAV, and the third resultant force and third resultant moment in the unfolded state according to the following formula:

Among them, F ₂ represents the second resultant force received by the UAV in the folded state, M ₂ represents the second resultant moment received by the UAV in the folded state, G _b represents the gravity of the UAV, and F _D represents the folded state of the UAV Under the aerodynamic resistance, F _c2 represents the binding force of the UAV at the connection point B of the suspension system (shown in Fig. 5 and Fig. 6), and M _c2 represents the restraining moment of the UAV at the connection point B. F _c2 and constraint moment M _c2 are given by the constraint equation, which need to be coupled with the parachute dynamic equation to solve (the solution method of constraint force F _c2 and constraint moment M _c2 is the same as the aforementioned constraint force F _c1 and constraint moment M _c1 ), ρ _c2 means no The position vector of the center of mass of the UAV in the second coordinate system in the folded state of the man-machine (given by assigning a value to the second initial condition), M _d2 represents the aerodynamic damping moment of the UAV in the folded state, F ₃ represents the UAV The third resultant force received in the deployed state, M ₃ represents the third resultant moment received in the deployed state of the UAV, F _a2 represents the aerodynamic force received in the deployed state of the UAV, ρ _c3 represents the unmanned force in the deployed state of the UAV The position vector of the center of mass of the UAV in the second coordinate system (given by assigning a value to the second initial condition), M _a2 represents the aerodynamic damping moment of the UAV in the unfolded state.

The expressions of the aerodynamic resistance F _D and M _d2 in the UAV body coordinate system in the folded state are:

表示无人机折叠状态下在无人机体坐标系下的速度；

分别为无人机折叠状态的阻力面积、阻力系数、阻力力矩系数，通过给第二初始条件赋值给定；

表示无人机折叠状态下气动焦点到重心的距离，通过给第二初始条件赋值给定；

为大气密度。in,

Indicates the speed of the UAV in the body coordinate system of the UAV when it is folded;

Respectively, the drag area, drag coefficient, and drag moment coefficient of the folded state of the UAV are given by assigning values to the second initial condition;

Indicates the distance from the aerodynamic focus to the center of gravity when the UAV is folded, and is given by assigning a value to the second initial condition;

is the atmospheric density.

The expression of the aerodynamic force F _a2 received by the UAV in the unfolded state in the UAV body coordinate system is:

Among them, X represents the component of F _a2 in the X-axis direction of the UAV body coordinate system, Y represents the component of F _a2 in the Y-axis direction of the UAV body coordinate system, and Z represents the Z of F _a2 in the UAV body coordinate system ρ represents the density of the atmosphere, V _b represents the velocity of the UAV in the UAV body coordinate system when the UAV is unfolded; S _w represents the reference area of the UAV wing; C _D represents the UAV under the unfolded state Aerodynamic drag coefficient; C _y represents the side force coefficient in the unfolded state of the UAV; C _L represents the lift coefficient in the unfolded state of the UAV _{( CD , Cy , and C L are given} by assigning values to the second initial condition).

The expression of the aerodynamic damping moment M _a2 in the unmanned aerial vehicle body coordinate system is:

Among them, l represents the component of Ma2 in the X-axis direction of the UAV body coordinate system, m represents the component of _Ma2 in the Y -axis direction of the UAV body coordinate system, and n represents _{the Z of Ma2} in _the UAV body coordinate system The component in the axial direction, ρ represents the atmospheric density, V _b represents the speed of the UAV body coordinate system in the unfolded state of the UAV; S _w represents the reference area of the UAV wing, which is given by assigning a value to the second initial condition ; C _l represents the roll moment coefficient, C _m represents the pitch moment coefficient, C _n represents the yaw moment coefficient, the aerodynamic moment coefficient of the UAV is given by assigning a value to the second initial condition; C _A represents the reference chord of the UAV Long and b represent the reference length of the wing of the UAV, and C _l , C _m , _{C n} , CA , b are given by assigning values to the second initial condition.

Step 10232: Establish the UAV dynamic equation, and establish the UAV six-degree-of-freedom model based on the UAV dynamic equation.

In practice, the UAV six-degree-of-freedom model is established by the second weight of the UAV, the second moment of inertia (the inherent characteristics of the UAV, which is a known quantity), the second resultant force, and the second resultant moment.

Generally, the UAV six-degree-of-freedom model is established in the six-degree-of-freedom module of the visual simulation mold Simulink. The modeling of the UAV body directly adopts the six-degree-of-freedom module, which makes the model simpler and meets the calculation efficiency of engineering applications on the basis of satisfying the accuracy.

Step 1024: Establish the dynamic equation of the suspension system as a constraint model. Generally, the constraint model of the umbrella-aircraft combination is built in the visual simulation tool Simulink.

Specifically, the dynamic equation of the suspension system is established, including:

The cross-connection point of the suspension system is analyzed by the balance point method, and the dynamic model of the suspension system is established based on the fact that the resultant force on the cross-connection point is zero.

Further, the dynamic equation of the hanging system is also obtained based on the number of paracords, the number of suspenders and the position vector of the connecting point.

As shown in Figure 5 and Figure 6, the core of the balance point method is to ensure that the tensions of the two ropes OB and BA are equal in each simulation time step, that is, the following constraint model is obtained:

The tension T _BO of the OB section rope is the binding force F _c1 of the connection point to the parachute, and the tension T _BA of the BA section rope is the binding force F _c2 of the connection point to the UAV, where T _BO and T _BA can be respectively expressed as for:

in,

表示各段伞绳的平均应变率（通过对各段伞绳的平均应变量ε_BO求导得到）、

表示各段吊带的平均应变率（通过对各段吊带的平均应变量ε_BA求导得到），

表示O点在大地坐标系中的位置矢量（可通过降落伞的平移运动方程得到其在大地坐标系中的位移量X，Y，Z来得到），

表示中间自由点B的位置矢量（通过约束方程平衡点法得到），

表示无人机机体上的连接点的位置矢量（可通过无人机的平移运动方程得到其在大地坐标系中的位移量X，Y，Z来得到），B_BO表示各段伞绳的张力阻尼系数、B_BA表示各段吊带的张力阻尼系数，均可表示为：Among them, N _BO represents the number of ropes of the BO section parachute, N _BA represents the number of ropes of the BA section sling, _{L 0} represents the initial length of the parachute, LA represents the initial length of the sling, and E _BO represents the elastic modulus of the parachute E _BA represents the elastic modulus of the sling (the inherent property of the sling, which is a known quantity), ε _BO represents the average strain of each section of parachute, ε _BA represents the The average strain of the segment sling,

Indicates the average strain rate of each section of parachute (obtained by deriving the average strain ε _BO of each section of parachute),

Indicates the average strain rate of each section of sling (obtained by deriving the average strain ε _BA of each section of sling),

Indicates the position vector of point O in the earth coordinate system (it can be obtained by obtaining its displacement X, Y, Z in the earth coordinate system through the translational motion equation of the parachute),

Represents the position vector of the intermediate free point B (obtained by the constraint equation equilibrium point method),

Indicates the position vector of the connection point on the drone body (it can be obtained by obtaining the displacement X, Y, and Z in the earth coordinate system through the translational motion equation of the drone), and B _BO indicates the tension of each section of the parachute The damping coefficient, B _BA represents the tension damping coefficient of each section of sling, which can be expressed as:

Among them, B ₀ represents the tension damping constant (unit: s ^-1 ), and the value range is [0 (no damping) ~ 0.5 (critical damping)]. m _i represents the mass of each section of paracord/sling, E _i represents the elastic modulus of each section of parachute/sling (a known quantity), ρ _i represents the linear density of each section of parachute/sling (a known quantity) .

After obtaining F _c1 and F _c2 , obtain the restraining moment M _c1 of the connection point to the parachute based on the product of force and moment, and the restraining moment M _c2 of the connection point to the UAV, and the three moments of each moment in the respective body coordinate system Components in the direction of the coordinate axis.

Among them, at the intersection point B of the harness-parachute system (that is, the suspension system), the dynamic modeling of the harness-paracord system is carried out through the balance point method, which can more truly reflect the attitude changes of the parachute and the UAV and the It can improve the accuracy of the analysis results and provide the initial attitude basis for the control of the UAV's subsequent parachuting to level flight.

In solving the equation, the inertial force of the converging mass point can be ignored but the effect of the restraint force of the suspenders is still considered, that is, the converging mass point is always in a state of static equilibrium.

Step 1025: Based on the six-degree-of-freedom model of the parachute, the six-degree-of-freedom model of the UAV, and the constraint model, an umbrella-machine composite model is obtained.

Among them, the umbrella-aircraft composite model includes the UAV kinematics model and the parachute kinematics model.

The kinematics modeling of UAV is obtained based on the visual simulation tool Simulink. Based on the UAV kinematics model and the mutual mapping relationship between the UAV body coordinate system and the parachute body coordinate system, the parachute kinematics model is obtained.

Specifically, the kinematics modeling of the parachute includes the establishment of translational kinematics equations and rotational kinematics equations.

Establishment of the translational kinematics equation: the parachute body coordinate system of the parachute body coordinate system and the UAV body coordinate system of the UAV body coordinate system are mapped to each other according to the following correspondence to establish the translational kinematics equation in MATLAB:

的表达式中的u、v、w分别用V_x、V_y、V_z的值替换，其中，

表示降落伞在大地坐标系下的速度分量，对其进行积分可得降落伞在大地坐标系的位移量X、Y、Z；θ、ϕ、Ψ表示降落伞在降落伞体坐标系下的欧拉角，可通过以下旋转运动学得到。about to

The u, v, and w in the expressions of are replaced by the values of V _x , V _y , V _z respectively, where,

Indicates the velocity component of the parachute in the earth coordinate system, which can be integrated to obtain the displacement X, Y, Z of the parachute in the earth coordinate system; θ , ϕ, Ψ represent the Euler angles of the parachute in the parachute body coordinate system, which can be Obtained by the following rotational kinematics.

Rotational kinematics equation:

的表达式中的p、q、r分别用ω_x、ω_y、ω_z的值替换。其中，

表示降落伞欧拉角的变化量。about to

p, q, r in the expression of are replaced by the values of ω _x , ω _y , ω _z respectively. in,

Indicates the amount of change in the Euler angle of the parachute.

The above-mentioned translational kinematics equations and rotational kinematics equations are both in the form of equations in the geodetic coordinate system.

By mapping the parachute body coordinate system and the UAV body coordinate system according to the corresponding conversion relationship, the kinematic equation of the parachute can be obtained directly based on the kinematic equation of the UAV, effectively utilizing the existing unmanned simulation model Simulink The machine kinematics module realizes that the process of flow field analysis and flexible body modeling can be eliminated under the condition of ensuring conformity to physical reality, and the efficiency of evaluation and simulation can be improved.

Step 1026: Simulate the umbrella-aircraft combination model based on the initial state quantities of the umbrella-aircraft combination.

Step 1027: until the simulation result of the parachute-aircraft combination model is consistent with the preset motion law; wherein, the umbrella-aircraft combination includes the parachute and the drone connected by a suspension system.

表示机体的俯仰角，θ为航迹倾角，α为攻角。Fig. 7 shows a schematic diagram of the force analysis of the UAV in the folded state and the force analysis of the parachute. In Fig. 7, F _D represents the aerodynamic resistance of the UAV in the folded state, and X _as represents the aerodynamic force of the parachute Resistance (aerodynamic force includes aerodynamic resistance), T and T′ represent the tension provided by the parachute, G _b represents the gravity of the UAV, G ₁ represents the gravity of the parachute, M _d2 represents the aerodynamic damping moment of the UAV in the folded state, M _c2 represents the restraining moment of the UAV at the intersection point B, M _G represents the gravity moment of the UAV in the folded state,

Indicates the pitch angle of the airframe, θ is the track inclination angle, and α is the attack angle.

Using the above steps to simulate the umbrella-aircraft combination, the following results are obtained: Figure 8 is the UAV pitch angle change curve provided by the embodiment of the present application. Fig. 9 is a variation curve of the pitch angle of the parachute provided by the embodiment of the present application. It can be seen from Fig. 8 and Fig. 9 that at 30s, the wings of the UAV are deployed, the aerodynamic lift increases, and the head-up moment is generated. Fig. 10 is the variation curve of the total tension of the sling provided by the embodiment of the present application. Fig. 11 is the three-way speed change curve of the drone provided by the embodiment of the present application. It can be seen from Fig. 10 and Fig. 11 that finally, under the deceleration of the parachute, the parachute-aircraft combination tends to descend at a steady speed, and the tension of the suspenders also tends to be constant.

The parachute-aircraft combination modeling method provided by the embodiment of the present invention uses a six-degree-of-freedom model to model the parachute and the UAV, which can not only simulate and analyze the motion of the center of mass during the UAV parachuting process, but also Simulate and evaluate the attitude of the parachute and UAV, as well as the force of the parachute strap, which improves the accuracy of the modeling model. The constraint model for building the parachute-aircraft combination includes the two stages of the UAV's wings being folded and wings being deployed during the real launch process, which more realistically simulates the drone's access control from launch to throwing down the parachute The previous movement process provides data support for the subsequent control of the UAV, reduces the number of physical tests, and saves design and development costs. The embodiment of the present invention realizes the parachute-aircraft combination modeling through a suitable and accurate modeling method in the UAV delivery process, so as to accurately simulate the motion of the parachute-UAV delivery system of the parachute-type UAV, and provide future reference. The UAV enters the controllable state to provide a theoretical basis.

In the embodiment of the present invention, the parachute and the UAV are respectively modeled with six degrees of freedom, and the balance point method is used at the connection point B of the suspender-parachute system, which can more truly reflect the attitude changes of the parachute and the UAV and the position of the suspenders. The force situation improves the accuracy of the analysis results, and provides the initial attitude basis for the control of the UAV's subsequent parachuting to level flight.

Another embodiment of the present invention provides a modeling device of an umbrella-aircraft combination, as shown in Figure 2, comprising:

The obtaining module 201 is used to obtain the first initial condition of the parachute, the second initial condition of the UAV, and the initial state quantity of the umbrella-aircraft combination.

The execution module 202 is used to execute modeling and simulation steps cyclically until the simulation result of the umbrella-aircraft combination model conforms to the preset motion law; wherein, the umbrella-aircraft combination includes a parachute and a drone connected by a suspension system.

Wherein, as shown in Figure 3, the execution module 202 includes:

The first establishment sub-module 2021 is used to establish the dynamic equation of the parachute in the parachute body coordinate system based on the first initial condition of the parachute.

Specifically, the first establishment submodule 2021 includes:

A calculation unit is used for calculating the generalized mass matrix of the parachute based on the first initial condition.

Specifically, the computing unit includes:

The acquisition subunit is used to obtain the additional mass of the parachute based on the additional mass coefficient, the atmospheric density, the characteristic volume of the parachute and the moment of inertia generated by the part of the gas displaced, and obtain the additional mass matrix of the parachute.

Calculation subunit, used to calculate the generalized inertia matrix of the parachute.

The determining subunit is used to determine the generalized mass matrix of the parachute; wherein, the generalized mass matrix is the sum of the additional mass matrix and the generalized inertia matrix.

The first establishment unit is used to establish the first resultant force and the first resultant moment equation on the parachute under the coordinate system of the parachute body. The first resultant force includes the binding force F _c1 of the parachute at the connection point of the suspension system, and the first resultant force The moment includes the binding moment M _c1 of the parachute at the point of intersection.

The second establishment unit is used to establish the dynamic equation of the parachute in the parachute body coordinate system according to the generalized mass matrix of the parachute, the first resultant force and the first resultant moment equation.

The third establishment unit is used to establish a six-degree-of-freedom model of the parachute based on the dynamic equation of the parachute.

The second establishment sub-module 2022 is used to establish a six-degree-of-freedom model of the parachute based on the dynamic equation of the parachute.

The third establishment sub-module 2023 is used to establish a six-degree-of-freedom model of the UAV in the UAV body coordinate system based on the second initial condition of the UAV.

Wherein, the third establishment submodule 2023 includes:

The fourth establishment unit is used to respectively establish the second resultant force and second resultant moment equation received by the UAV in the folded state, and the third resultant force and third resultant moment equation received by the UAV in the unfolded state in the body coordinate system of the UAV , both the second resultant force and the third resultant force include the binding force F _c2 of the connecting point of the suspension system on the UAV, and the second resultant moment and the third resultant moment include the restraining moment M _c2 of the connecting point on the UAV;

The fifth establishment unit is used to establish a dynamic equation of the UAV, and establish a six-degree-of-freedom model of the UAV based on the dynamic equation of the UAV.

The fourth establishment sub-module 2024 is used to establish the dynamic equation of the suspension system as a constraint model.

Wherein, the fourth establishment sub-module 2024 is specifically used to analyze the cross-connection point of the suspension system through the balance point method, and establish the dynamic equation of the suspension system based on the fact that the resultant force on the cross-connection point is zero.

Further, the fourth establishment sub-module 2024 is also used to obtain the dynamic equation of the suspension system based on the number of paracords, the number of suspenders and the position vector of the connection point.

The obtaining sub-module 2025 is used to obtain the parachute-machine combination model based on the parachute six-degree-of-freedom model, the UAV six-degree-of-freedom model and the constraint model.

Among them, the umbrella-aircraft composite model includes the UAV kinematics model and the parachute kinematics model. Based on the UAV kinematics model and the mutual mapping relationship between the UAV body coordinate system and the parachute body coordinate system, the parachute kinematics model is obtained.

The simulation sub-module 2026 is used for simulating the umbrella-aircraft combination model based on the initial state quantities of the umbrella-aircraft combination.

Another embodiment of the present invention provides a server, including: a memory and a processor.

The memory is used to store program instructions.

The processor is used to execute program instructions in the server, so that the server executes the above-mentioned modeling method of the umbrella-aircraft combination.

Another embodiment of the present invention provides a computer-readable storage medium. The computer-readable storage medium stores executable instructions. When the computer executes the executable instructions, the above-mentioned modeling method of the umbrella-aircraft combination can be realized.

The above-mentioned storage media include but are not limited to random access memory (English: Random Access Memory; abbreviation: RAM), read-only memory (English: Read-Only Memory; abbreviation: ROM), cache (English: Cache), hard disk (English: Hard Disk Drive (abbreviation: HDD) or memory card (English: Memory Card). The memory can be used to store computer program instructions.

Although the present application provides method operation steps such as embodiments or flowcharts, more or less operation steps may be included based on routine or non-inventive efforts. The order of steps listed in this embodiment is only one way of execution order of many steps, and does not represent the only execution order. When an actual device or client product is executed, it may be executed sequentially or in parallel (for example, in a parallel processor or multi-threaded processing environment) according to the method shown in this embodiment or the accompanying drawings.

The devices, modules, or units described in the above embodiments can be specifically implemented by computer chips or entities, or by products with certain functions. For the convenience of description, when describing the above devices, functions are divided into various modules and described separately. When implementing the present application, the functions of each module can be implemented in one or more software and/or hardware. Of course, a module that realizes a certain function may also be implemented by a combination of multiple submodules or subunits.

The method, device or module in the present application can be implemented in a computer-readable program code and the server can be implemented in any appropriate way. For example, the server can adopt, for example, a microprocessor or a processor and store a computer that can be executed by the (micro)processor. Computer-readable media that read program code (such as software or firmware), logic gates, switches, application-specific integrated circuits (English: Application Specific Integrated Circuit; abbreviation: ASIC), programmable logic servers, and embedded micro-servers. Examples include, but are not limited to, the following microservers: ARC 625D, AtmelAT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F320. Those skilled in the art also know that, in addition to realizing the operation of the server in the form of pure computer-readable program codes, it is entirely possible to make the server operate with logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microprocessors through logic programming of the method steps. Controller etc. to achieve the same function. Therefore, such a server can be regarded as a hardware component, and the devices included in it for realizing various functions can also be regarded as a structure within the hardware component. Or even, means for realizing various functions can be regarded as a structure within both a software module realizing a method and a hardware component.

Some of the modules in the apparatus of the present application may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, classes, etc. that perform particular tasks or implement particular abstract data types. The application may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including storage devices.

It can be known from the above description of the implementation manners that those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary hardware. Based on this understanding, the essence of the technical solution of this application or the part that contributes to the existing technology can be embodied in the form of software products, or it can be reflected in the implementation process of data migration. The computer software product can be stored in a storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., and includes several instructions to make a computer device (which can be a personal computer, mobile terminal, server, or network device, etc.) execute this Apply the methods of each embodiment or some parts of the embodiments.

The various implementations in this specification are described in a progressive manner, the same or similar parts of the various implementations can be referred to each other, and each implementation focuses on the differences from other implementations. This application, in whole or in part, can be used in numerous general purpose or special purpose computer system environments or configurations. Examples: personal computers, server computers, handheld or portable devices, tablet-type devices, mobile communication terminals, multiprocessor systems, microprocessor-based systems, programmable electronic devices, network PCs, minicomputers, mainframe computers, including A distributed computing environment for any of the above systems or devices, etc.

The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be described in the foregoing embodiments Modifications to the technical solutions, or equivalent replacement of some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the present application.

Claims (10)

1. A modeling method of an umbrella-machine combination, characterized in that, comprising: Obtain the first initial condition of the parachute, the second initial condition of the UAV, and the initial state quantity of the parachute-aircraft combination; The modeling and simulation steps are executed cyclically until the simulation result of the umbrella-aircraft combination model matches the preset motion law; wherein, the umbrella-aircraft combination includes the parachute and the unmanned aerial vehicle connected by a suspension system; Wherein, the modeling and simulation steps include: Based on the first initial condition of the parachute, the dynamic equation of the parachute is established under the parachute body coordinate system; Based on the dynamic equation of the parachute, a parachute six-degree-of-freedom model is established; Based on the second initial condition of the unmanned aerial vehicle, a six-degree-of-freedom model of the unmanned aerial vehicle is established under the unmanned aerial vehicle body coordinate system; Establish the dynamic equation of the suspension system as a constraint model; Based on the parachute six-degree-of-freedom model, the UAV six-degree-of-freedom model and the constraint model, an umbrella-aircraft composite model is obtained; The parachute-aircraft combination model is simulated based on the initial state quantities of the umbrella-aircraft combination. 2. the modeling method of umbrella-machine assembly according to claim 1, is characterized in that, described first initial condition based on described parachute, under parachute body coordinate system, establishes the dynamic equation of parachute, comprises: calculating a generalized mass matrix of the parachute based on the first initial conditions; In the parachute body coordinate system, establish the first resultant force and the first resultant moment equation that the parachute is subjected to, the first resultant force includes the binding force F _c1 of the parachute at the cross-connection point of the suspension system, and the The first resultant moment includes the binding moment M _c1 of the parachute at the intersection point; According to the generalized mass matrix of the parachute, the first resultant force and the first resultant moment equation, the dynamic equation of the parachute in the parachute body coordinate system is established. 3. The modeling method of umbrella-aircraft combination according to claim 2, is characterized in that, the generalized mass matrix of described parachute calculation based on described first initial condition comprises: Obtain the additional mass of the parachute based on the additional mass coefficient, the atmospheric density, the characteristic volume of the parachute and the moment of inertia generated by displacing part of the gas, and obtain the additional mass matrix of the parachute; calculating a generalized inertia matrix for the parachute; determining a generalized mass matrix of the parachute; wherein, the generalized mass matrix is the sum of the additional mass matrix and the generalized inertia matrix. 4. the modeling method of umbrella-aircraft combination according to claim 1, it is characterized in that, described based on the second initial condition of described unmanned aerial vehicle, set up unmanned aerial vehicle six degrees of freedom under unmanned aerial vehicle body coordinate system models, including: In the UAV body coordinate system, respectively establish the second resultant force and the second resultant moment equation received in the folded state of the UAV, and the third resultant force and the third resultant moment equation received in the unfolded state, the second Both the resultant force and the third resultant force include the restraining force F _c2 of the connecting point of the suspension system on the UAV, and the second resultant moment and the third resultant moment include the restraining moment of the connecting point on the UAV M _c2 ; A dynamic equation of the unmanned aerial vehicle is established, and a six-degree-of-freedom model of the unmanned aerial vehicle is established based on the dynamic equation of the unmanned aerial vehicle. 5. the modeling method of umbrella-aircraft combination according to claim 1, is characterized in that, based on unmanned aerial vehicle kinematics model, and the mutual mapping relation of unmanned aerial vehicle body coordinate system and parachute body coordinate system, obtains parachute kinematics Model; The umbrella-aircraft combination model includes the UAV kinematics model and the parachute kinematics model. 6. the modeling method of umbrella-aircraft combination according to claim 1, is characterized in that, described setting up the dynamic equation of described suspension system, comprises: The cross-connection point of the suspension system is analyzed by the balance point method, and the dynamic equation of the suspension system is established based on the fact that the resultant force on the cross-connection point is zero. 7. The modeling method of the umbrella-aircraft combination according to claim 6, characterized in that, the dynamic equation of the suspension system is also obtained based on the quantity of the parachute rope, the quantity of the suspenders and the position vector of the connecting point. 8. A modeling device of an umbrella-aircraft combination, characterized in that it comprises: Obtaining module, for obtaining the first initial condition of parachute, the second initial condition of unmanned aerial vehicle and the initial state quantity of parachute-aircraft assembly; The execution module is used to perform the modeling and simulation steps cyclically until the simulation result of the umbrella-aircraft combination model conforms to the preset motion law; wherein, the umbrella-aircraft combination includes the parachute and the parachute connected through the suspension system. UAV; Wherein, the execution module includes: The first establishment sub-module is used to establish the dynamic equation of the parachute in the parachute body coordinate system based on the first initial condition of the parachute; The second establishes a submodule, which is used to establish a parachute six-degree-of-freedom model based on the dynamic equation of the parachute; The third establishment sub-module is used to establish a six-degree-of-freedom model of the UAV in the UAV body coordinate system based on the second initial condition of the UAV; The fourth establishment sub-module is used to establish the dynamic equation of the suspension system as a constraint model; Obtaining a sub-module for obtaining an umbrella-aircraft combination model based on the parachute six-degree-of-freedom model, the UAV six-degree-of-freedom model and the constraint model; The simulation sub-module is used for simulating the umbrella-aircraft combination model based on the initial state quantity of the umbrella-aircraft combination. 9. A server, comprising: a memory and a processor; The memory is used to store program instructions; The processor is used to execute program instructions in the server, so that the server executes the modeling method of the umbrella-aircraft combination according to any one of claims 1-7. 10. A computer-readable storage medium, wherein the computer-readable storage medium stores executable instructions, and when the computer executes the executable instructions, the umbrella described in any one of claims 1 to 7 can be realized. -Modeling methods for machine assemblies.

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