Shipborne captive balloon multi-body dynamics modeling and numerical simulation method

Abstract

The invention discloses a shipborne captive balloon multi-body dynamics modeling and numerical simulation method, which comprises the following steps: establishing a multi-rigid-body dynamics model of a shipborne captive balloon, programming the modeling process by using a programming language, completing secondary development modeling and simulation in multi-body dynamics calculation software, and submitting to a solver for calculation. Based on the advantage that shaft sleeve force one-class flexible connection can equivalently replace spherical hinge pair one-class rigid connection in the system, the number of constraint equations in a vehicle multi-body system kinetic equation is reduced, and then more efficient real-time simulation and control of the shipborne captive balloon are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of ship-borne tethered balloons, and in particular relates to a multi-body dynamics modeling and numerical simulation method for a ship-borne tethered balloon. Background Art

[0002] A tethered balloon is an aerostat that relies on the lighter-than-air gas in its body to provide buoyancy to rise and stay in the air. It is connected to the mooring equipment through a mooring cable and is the most mature type of aerostat in terms of technology development and application. As a branch of the tethered balloon, the ship-borne tethered balloon can use the ship as an anchoring platform to observe the sea conditions over a large area and provide weather warnings on the sea surface.

[0003] As the application fields of tethered balloons gradually increase, people have increasingly stringent requirements on the altitude, cruising time, anti-interference ability and shape of tethered balloons. This requires further optimization of the performance, strength and stability of the tethered balloon system and its components in all aspects. However, the tethered cable is heavy, and the wind field range of the tether span is large, the force is complex, the horizontal wind resistance integral effect is obvious, and the wind speed difference between the troposphere and the stratosphere is large. The cable and the balloon are prone to abnormal posture and failure, and dynamic analysis is difficult. Therefore, modeling and mechanical analysis of the tethered balloon system has important theoretical significance and engineering practical value for promoting the development of tethered balloons.

[0004] In recent years, experts and scholars at home and abroad have studied the current mainstream solutions to the attitude and force analysis of tethered balloons. When solving related problems, most of them are based on structural mechanics, computational fluid dynamics and thermodynamics. Start from three aspects: stress and strain on the surface of the tethered balloon, overall shape change and overall force analysis of the system. Solutions from the perspective of multi-body system dynamics mainly focus on the force and attitude change analysis of each component of the balloon, and related research can be further carried out. In addition, the calculation cycle of force analysis and attitude change of tethered balloons using structural mechanics, computational fluid dynamics and thermodynamics is long, and the third-party commercial software based on finite elements is highly packaged, and it is impossible to set external loads for specific working conditions. Summary of the invention

[0005] Purpose of the Invention

[0006] In view of the technical problem that the cables and balloon bodies of tethered balloons are prone to abnormal postures and failure, and dynamic analysis is difficult, the present invention provides a multi-body dynamics modeling and numerical simulation method for a ship-borne tethered balloon.

[0007] Inventing technical solutions

[0008] A multi-body dynamics modeling and numerical simulation method for a ship-borne tethered balloon comprises: (1) establishing a discrete multi-rigid body-sleeve force / torque model of the ship-borne tethered balloon rope system. First, the tethered cable is discretized into a combination of multiple cylindrical rigid body components, and adjacent components are connected by ball joints. According to the force conditions, all other ball joint rigid connections except the ones directly connected to the hull and the balloon are replaced by shaft sleeve force / torque connections. Based on the cable material properties and the calculation formula of the shaft sleeve force, a discrete multi-rigid body-sleeve mechanical model of the tethered cable is established.

[0009] (2) Considering the influence of wind load on the tethered balloon body and waves on the hull, mechanical models corresponding to different external loads are established. For the external wind load mechanical model, calculation formulas for aerodynamic lift, aerodynamic drag, aerodynamic lateral force, aerodynamic pitch moment, aerodynamic yaw moment and aerodynamic roll moment are constructed respectively. At the same time, an external wave load driving function model is constructed, and the displacement and rotation of the ship under the action of wave load are sorted into a time series data table. At each moment, the corresponding displacement and rotation are input, and the force and moment are calculated by the dynamic formula of the rigid body. When the analysis object is a ship, the value of the wind load mechanical model is 0, and when the calculation object is the cable and the tethered balloon, the constraint driving function value of the wave load is 0.

[0010] (3) Establish the multi-rigid body dynamic equations of the ship-borne tethered balloon as a whole. Decompose the components of the ship-borne tethered balloon system to obtain the hull, balloon and several cable subsystems, where the hull and balloon are regarded as rigid bodies with 6 degrees of freedom, and each cable is discretized into a subsystem composed of multiple cylindrical rigid body components. Establish a global Cartesian reference coordinate system for the multi-body system, with the geometric center point of the tethered balloon at rest as the coordinate origin. At the same time, establish a local Cartesian reference coordinate system with the virtual reference point on each component extending to the origin of the global coordinate system as the origin of the local reference coordinate system. In this way, the position vector and direction vector of each component of the system can be obtained. Considering the force / torque of the multi-rigid body-sleeve and the external wind load, based on the principle of virtual work, and introducing the system and wave load constraints through the Lagrange multiplier method, the multi-body system dynamic equations of the entire system are obtained.

[0011] (4) The modeling process was programmed in a procedural language and secondary development was completed in the multibody dynamics software. The geometric shape, kinematic relationship, sleeve force, and external load models of each component were constructed through a Python script loop, and the measurement parameters were set. Finally, calculations and evaluations were performed in Adams / View to achieve real-time analysis of the motion responses of the components of the ship-borne tethered balloon system.

[0012] Advantages of the present invention: Based on the mechanical formula of the sleeve force, the present invention can effectively decompose the cable into several discrete rigid bodies, and perform equivalent replacement of the rigidly connected ball joint pair, thereby reducing the number of constraint equations in the ship-borne tethered balloon system and achieving more efficient real-time simulation calculations. By combining Python programming language and Adams' Python-oriented API interface, the present invention designs a programmatic modeling method for a ship-borne tethered balloon and establishes a multi-body system dynamics model. Simulation verification and evaluation of the motion response of the ship-borne tethered balloon system were carried out under specific sea conditions, wind speeds and different wind directions. This method achieves the goal of performing simulation analysis under simulated actual working conditions, provides model support and design reference for the theoretical design and actual launch test of the ship-borne tethered balloon, and has important theoretical value for studying the attitude changes of the system under different sea conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The schematic diagram of the mooring cable discrete multi-rigid body-sleeve force model equivalent to the discrete multi-rigid body-spherical joint model;

[0014] Figure 2 It is the kinematic connection diagram of each component in the system;

[0015] Figure 3 It is the aerodynamic coefficient data fitting diagram;

[0016] Figure 4 is the wave load driving function diagram;

[0017] Figure 5 A multi-body dynamics model of a ship-borne tethered balloon constructed through secondary development in Adams;

[0018] Figure 6 The motion of a ship-borne tethered balloon under the combined load of wind and waves;

[0019] Figure 7 The wind speed is 15m / s, the significant wave height is 6.894m, the wave load with a zero-crossing period of 12.13s, 320 discrete rigid bodies, and the pitch angle change diagram of the balloon under three conditions: 0° deflection, 5° deflection, and 10° deflection of the wind direction directly facing the balloon head.

[0020] Figure 8 The wind speed is 15m / s, the significant wave height is 6.894m, the wave load crosses zero period 12.13s, 320 discrete rigid bodies, and the wind direction is directly facing the balloon head with 0° deflection, 5° deflection and 10° deflection.

[0021] Fig. 9The roll angle change diagram of the balloon is shown in the following figure: the wind speed is 15m / s, the significant wave height is 6.894m, the wave load with a zero-crossing period of 12.13s, 320 discrete rigid bodies, and the wind direction is directly facing the balloon head with a deflection of 0°, 5°, and 10°.

[0022] Fig.10 (a) and (b) are the force and moment diagrams of the discrete rigid body numbered 100 in the middle of the cable under the conditions of 15 m / s wind speed, 6.894 m significant wave height, 12.13 s wave load across zero period, 320 discrete rigid bodies, and wind direction facing the balloon head with 0° deflection, 5° deflection, and 10° deflection.

[0023] Fig.11 The modeling process of a specific physical model using the discrete multi-rigid body-spherical joint method.

[0024] Fig.12 The X-direction displacement diagram of the tethered balloon when the wind speed is 15m / s, the significant wave height is 6.894m, the wave load with a zero-crossing period of 12.13s, the wind direction is directly facing the balloon head with a 0° deflection, and the mooring cable segments are 220, 320, and 420 segments respectively.

[0025] Fig.13 The Y-direction displacement diagram of the tethered balloon when the wind speed is 15m / s, the significant wave height is 6.894m, the wave load with a zero-crossing period of 12.13s, the wind direction is directly facing the balloon head with a 0° deflection, and the number of mooring cable segments is 220, 320, and 420 respectively.

[0026] Fig.14 The wind speed is 15m / s, the significant wave height is 6.894m, the wave load crosses zero period 12.13s, the wind direction is directly facing the balloon head with 0° deflection, and the pitch angle change diagram of the tethered balloon when the number of mooring cable segments is 220, 320 and 420 respectively.

[0027] Fig.15 The violin plot of the statistical time series data of the displacement and attitude of the tethered balloon when the wind speed is 15m / s, the significant wave height is 6.894m, the wave load with a zero-crossing period of 12.13s, the wind direction is directly facing the balloon head with a 0° deflection, and the number of mooring cable segments is 220, 320 and 420 respectively.

[0028] Fig.16 This is the system model architecture diagram. DETAILED DESCRIPTION

[0029] The present invention is achieved through the following technical solutions.

[0030] See also Figures 1 to 6 , Figure 11-Figure 15, a ship-borne tethered balloon multi-body dynamics modeling and numerical simulation method, including the following steps: discrete multi-rigid body-spherical joint method modeling principle as Fig.13 shown.

[0031] 1. Establish a dynamic model of a ship-mounted tethered balloon.

[0032] (1) Establishing a multi-rigid body dynamic model of the entire ship-borne tethered balloon. The multi-body system is a ship-borne tethered balloon.

[0033] The steps of establishing the multi-rigid body dynamic equation of the ship-borne tethered balloon include:

[0034] ① Decompose the components of the multi-body system to obtain several rigid bodies with 6 degrees of freedom, and write them into the component set N.

[0035] ② Establish a global Cartesian reference coordinate system for the multi-body system; the origin of the global Cartesian coordinate system is the geometric center point of the tethered balloon when it is stationary.

[0036] ③ Select part i from the part set N, and use the virtual reference point s on part i that extends to the origin of the global coordinate system as the origin of the local reference coordinate system to establish a local Cartesian reference coordinate system. The initial value of i is 1.

[0037] ④ Determine whether i≥n is true. If so, proceed to step ⑤. Otherwise, set i=i+1 and return to step ③; n is the number of elements in the component set N;

[0038] ⑤Establish the Cartesian coordinates q of the multi-body system, that is:

[0039] q i ≡[x i ,y i ,z i ,ψ i ,θ i ,φ i ] T =(r i z i ) T (1)

[0040] In the formula, r=(r 1 r 2 …r n ) T is the position matrix of the local coordinates of the rigid body in the global coordinate system, z = (z 1 z 2 …z n ) T is the direction matrix of the local coordinates of the rigid body in the global coordinate system.

[0041] ⑥ According to the principle of virtual work, the constraint equation is introduced using Lagrange multipliers to obtain the multi-body mechanics of the system:

[0042]

[0043] Where M is the rigid body mass matrix of the system, Φ is the constraint equation of the system, F is the external force matrix of the system, p is the external torque matrix of the system, J′ is the inertia tensor matrix of the system, and ω is the angular velocity matrix of the system.

[0044] (2) Establishing the discrete multi-rigid body-sleeve force dynamics equation of the ship-borne tethered balloon multi-body system, the steps include:

[0045] ① Establish the discrete multi-rigid body dynamic equation of the mooring cable with the spherical joint as the constraint, as follows Figure 1 As shown, that is:

[0046]

[0047] In the formula, A i is the Euler rotation matrix of the local coordinates of the cable discrete rigid body i relative to the global coordinates, and s is the vector of the spherical joint sub-center in the local coordinate system of the discrete rigid body.

[0048] ② Replace the rigid constraint equation of some spherical joints with the force / torque constraint equation of the sleeve model, as follows: Figure 1 As shown, that is:

[0049]

[0050] Q bu =[F bu p bu ] T =K·Δq (9)

[0051] In the formula, F bu is the sleeve force generated when the adjacent discrete rigid body is displaced, P bu is the sleeve torque generated when the adjacent discrete rigid bodies rotate, Q bu is the generalized sleeve force, K is the sleeve stiffness coefficient matrix, and its matrix is ​​diag(k 11 , k 22 , k 33 , k 44 , k 55 , k 66 ), the value of k is related to the material properties, and Δq is the generalized relative displacement of adjacent discrete rigid bodies.

[0052] ③ Combining the Newton-Euler dynamics equation of the spatial constraint system, the spherical joint constraint equation, and the force / torque constraint equation of the sleeve model, the discrete multi-rigid body-sleeve force dynamics equation of the mooring cable is established, namely:

[0053]

[0055] Where n is the number of discrete rigid bodies of the cable, and i is the number of connection relationships between discrete rigid bodies. When i is 1 and n+1, it represents the connection relationship between the first and last ends of the cable and the other components of the ship-borne tethered balloon system, such as Figure 2 shown.

[0056] (3) The rigid connection of some ball joints is replaced by the force / torque model of the sleeve model. The equivalent sleeve force model is established by using the cable material properties and the calculation formula of the sleeve force, namely:

[0057] Q bu =[F bu p bu ] T =K·Δq=K·(ΔrΔz) T (14)

[0058] F bu =diag(k 11 k 22 k 33 )·Δr (15)

[0059] p bu =diag(k 44 k 55 k 66 )·Δz (16)

[0060] Where Δr is the relative displacement of adjacent discrete rigid bodies, and Δz is the relative rotation angle of adjacent discrete rigid bodies. In formulas 10 and 11, when the sleeve force and moment between discrete rigid bodies are not zero, their magnitudes can be calculated according to formulas 15-16.

[0061] (4) Establish a mechanical model corresponding to different external loads, including the wind load of the tethered balloon and the wave force acting on the hull, and introduce the external loads into the dynamic equation.

[0062] ①Construct the external wind load mechanical model, namely:

[0063]

[0064] In the formula, F L is the aerodynamic lift, F D is the aerodynamic drag, F Z is the aerodynamic lateral force, T a , T Y , T R are the aerodynamic pitch moment, aerodynamic yaw moment and aerodynamic roll moment respectively. Correspondingly, C L , CD , C Z , C a , C Y , C R are the aerodynamic lift coefficient, aerodynamic drag coefficient, aerodynamic side force coefficient, aerodynamic pitch moment coefficient, aerodynamic yaw moment coefficient and aerodynamic roll moment coefficient, respectively, ρ air is the air density, v air is the air flow velocity, that is, wind speed, and the calculation of the aerodynamic coefficient is as follows Figure 3 shown.

[0065] ②Construct the external wave load driving function model, namely:

[0066]

[0067] In the formula, Ф S is the driving constraint function of the ship in the ship-borne tethered balloon system, which is divided into the movement constraint Ф K and the rotation constraint Ф D The displacement and rotation of the ship under the action of wave load are sorted into a time series data table, and the corresponding displacement and rotation are input at each moment, and the force and moment are calculated by the dynamic formula of the rigid body.

[0068] ③ Load the external load model into the unified dynamic model of the ship-borne tethered balloon, that is:

[0069]

[0070] Among them, the effect of wind load on the ship has been calculated by the driving function. When the unified dynamics formula is used to calculate the ship, the wind load mechanical model F b and p b is 0, and when the unified dynamics formula is used to calculate the cable and the tethered balloon, the constraint driving function of the wave load is K and Φ D is 0, the constraint driving function of the ship under the action of wave load is as follows Figure 4 shown.

[0071] 2. Program the modeling process in a procedural language and complete secondary development simulation in multi-body dynamics software. The steps include:

[0072] (1) Using the variable n in Python, through the program loop structure and the API midpoint and rigid body modeling statements, the shapes of each component in the system and their initial positions and directions in the global coordinate system are established;

[0073] (2) Using the variable i in Python, through the program loop structure and the kinematic pair modeling statements in the API, the kinematic pair relationships of each component in the system are established;

[0074] (3) Using the string form in Python, through the program loop structure and the sleeve force and generalized force modeling statements in the API, the sleeve force and external wind load on each component in the system are established;

[0075] (4) Using the string form in Python, through the program loop structure and the spline curve and drive function modeling statements in the API, the wave load drive on the ship components in the system is established;

[0076] (5) Use the measurement statements in the API to pre-set the simulation quantities that need to be measured, including the pitch angle, yaw angle, roll angle of the balloon component, and the displacement, force, and torque of the cable discrete rigid body.

[0077] (6) The .py file written in Python and combined with the Adams API interface is opened in Adams / View to perform calculations and solutions, and evaluate the measurement items under different working conditions. This can effectively evaluate the motion response of each component in the ship-borne tethered balloon system in real time.

[0078] The multi-body dynamics model of a ship-borne tethered balloon constructed in Adams through programming language and API interface is as follows: Figure 5 The external load parameters under different working conditions are characterized by: the number of discrete rigid bodies is 220, 320 and 420, the wind speed is determined to be 15m / s, the wind direction is determined to be 0° deflection directly facing the balloon head, the sea state is determined to be level 4, the significant wave height is 6.894m, the period is 12.13s, and the wave direction is determined to be 45° directly facing the ship. The motion of the system under the combined wind and wave load is shown in the figure. Figure 6 shown.

[0079] 3. The modeling principle of discrete multi-rigid body-spherical joint method is as follows Fig.11 As shown in the figure, the working condition analysis comparison of the ship-mounted tethered balloon with different numbers of cable discrete rigid bodies is as follows: Figure 12-15 shown.

[0080] (1) In terms of the absolute value of the tethered balloon displacement, the X displacement of the balloon of the ship-borne tethered balloon system with a tethered cable with 420 segments increased by 0.65 m, and the Y displacement increased by 0.43 m compared with the case with 220 segments, with a change of less than 0.1%, while the pitch angle increased by 0.61°, an increase of more than 3.6%, and the overall change was no more than 5%. This means that the current number of cable segments has reached the convergence value of the cable segment number, and continuing to increase the number of cable segments will not cause a significant change in the balloon motion posture of the system, and it tends to be stable.

[0081] Table 1 Motion response of the system under different cable segment numbers

[0082]

[0083]

[0084] (2) From the perspective of time series data, different numbers of cable segments will have a significant impact on the attitude of the tethered balloon. The time series data set of the model with 220 segments is narrow as a whole, while the time series data of the other two models are relatively concentrated when the pitch angle is 1-2°. This phenomenon shows that the pitch angle of the model with 220 segments changes faster than that of the other two models during the entire simulation process, while the pitch angle of the balloon in the models with 320 and 420 segments is stable for a longer time within a certain range during the simulation process. Therefore, when the balloon is subjected to a greater external load, the model with 220 segments may cause the balloon attitude to become abnormal or even fail due to the rapid change of the balloon pitch angle.

[0085] (3) When the external load increases, the balloon of the model with 420 segments is at a larger pitch angle for a longer time than other models, so the possibility of abnormal posture is also relatively large. Therefore, the number of cable segments has a certain influence on the overall motion response of the system. It is necessary to select a suitable number of segments to ensure that the possibility of system failure is small, so as to maintain the characteristics of the tethered balloon working for a long time.

[0086] In summary, the sample parameters analyzed in this embodiment cover the modeling and simulation analysis of the motion response of ship-borne tethered balloons under different numbers of segments and different wind directions. The results show that for the working conditions of different wind directions, the current tethered balloon needs to be further optimized in the balloon shape and the location of the tethered cable to ensure the anti-crosswind performance of the tethered balloon system. And through a simple comparison, comprehensive calculation time, calculation accuracy, and considering the degree of consistency between the model and the real system, the ship-borne tethered balloon dynamics simulation analysis is more ideal when the number of segments of the tethered cable is 320.

[0087] The protection scope of the present invention is not limited to the above-mentioned embodiments. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the scope of the present invention. If these changes and modifications fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include these changes and modifications.

Claims

1. A method for multi-body dynamics modeling and numerical simulation of a ship-borne tethered balloon, characterized in that: The method establishes a multi-rigid body dynamics model of a ship-borne tethered balloon. The steps of establishing the multi-rigid body dynamics model of a ship-borne tethered balloon include: (1) Establish a multi-rigid body dynamic model of the entire ship-borne tethered balloon; (2) The mooring cable is divided into several cylindrical discrete rigid bodies, which are connected by shaft sleeve forces, and the discrete multi-rigid body-shaft sleeve force dynamic equation is established; (3) Determine the dynamic evaluation parameters: balloon pitch angle, balloon yaw angle, balloon roll angle, discrete rigid body displacement, discrete rigid body force and torque; (4) The rigid connection of some ball joints is equivalently replaced by the force and moment model of the sleeve model; (5) Determine external load parameters: number of discrete rigid bodies, wind speed, wind direction, sea state level, and wave direction; (6) Establish mechanical models corresponding to different external loads and import them into the established multi-rigid body dynamics model; finally, program the modeling process using a programming language.

2. A method for multi-body dynamics modeling and numerical simulation of a ship-borne tethered balloon as claimed in claim 1, characterized in that: Step (1) includes: establishing a global Cartesian reference coordinate system of the multi-body system and a local Cartesian reference coordinate system of each component with a virtual reference point extending from the center of gravity or the center of the geometric shape to the origin of the global coordinate system as the origin of the coordinate system, thereby further expressing the Cartesian coordinate q of component i: q i ≡[x i ,y i ,z i ,ψ i ,θ i ,φ i ] T =(r i z i ) T 1) In the formula, r i is the position matrix of the local coordinates of rigid body i in the global coordinate system, including the displacement x in the X, Y, and Z directions i ,y i , z i ; z i is the direction matrix of the local coordinates of rigid body i in the global coordinate system, including the rotation ψ in the X, Y, and Z directions i ,θ i ,φ i .

3. The method for multi-body dynamics modeling and numerical simulation of a ship-borne tethered balloon according to claim 1, characterized in that: In step (2), the external wind load and wave load are first considered, and the discrete multi-rigid body dynamic equation of the cable with the spherical joint as the constraint is established: Where M is the rigid body mass matrix of the system; and They are the movement and rotation driving constraint functions of the ship in the ship-borne tethered balloon system. The displacement and rotation of the ship under the action of wave load are sorted into a time series data table. The corresponding displacement and rotation are input at each moment, and the force and moment are calculated by the dynamic formula of the rigid body; Φ p and Φ d is the constraint equation of the bushing model; λ is the Lagrange multiplier; F b and P b are the force and equivalent moment matrices of wind loads respectively; F b and P b are the sleeve force and torque respectively; J′ is the system inertia tensor matrix, and ω is the system angular velocity matrix.

4. A method for multi-body dynamics modeling and numerical simulation of a ship-borne tethered balloon as claimed in claim 3, characterized in that: The rope structure in the mooring cable system is decomposed into a combination of multi-end cylindrical rigid bodies and connected by equivalent sleeves. The equivalent sleeve force in step (4) can be calculated by the following formula: Q bu =[F bu p bu ] T =K·Δq=K·(Δr Δz) T (4) F bu =diag(k 11 k 22 k 33 )·Δr (5) p bu =diag(k 44 k 55 k 66 )·Δz (6) Where K is the stiffness coefficient matrix of the sleeve force, k 11 ~k 66 is the translational or rotational stiffness coefficient of the sleeve force, Δr is the relative displacement of adjacent discrete rigid bodies, and Δz is the relative rotation angle of adjacent discrete rigid bodies. In formulas (2) and (3), when the sleeve force and moment between discrete rigid bodies are not zero, their magnitudes are calculated according to formulas (5) and (6); The constraint equation of the equivalent bushing model is expressed as: In the formula, A i is the Euler rotation matrix of the local coordinates of the cable discrete rigid body i relative to the global coordinates, s p is the vector of the spherical joint subcenter in the local coordinate system of the discrete rigid body, r j Represents the vector from the sub-center of the spherical joint of rigid body j to the origin of the global coordinate system, Represents the vector of the sub-center of the spherical joint on the rigid body j in the local coordinate system of the discrete rigid body.

5. The method for multi-body dynamics modeling and numerical simulation of a ship-borne tethered balloon according to claim 3, characterized in that: In step (5), the external wind load model is established in the form of force: F b =(F D F L F Z ) T (8) p b =(T R T Y T a ) T (9) In the formula, F L is the aerodynamic lift, F D is the aerodynamic drag, F Z is the aerodynamic lateral force, T a , T Y , T R are the aerodynamic pitch moment, aerodynamic yaw moment and aerodynamic roll moment respectively; accordingly, C L , C D , C Z , C a , C Y , C R are the aerodynamic lift coefficient, aerodynamic drag coefficient, aerodynamic side force coefficient, aerodynamic pitch moment coefficient, aerodynamic yaw moment coefficient and aerodynamic roll moment coefficient, respectively, ρ air is the air density, v air is the air flow speed, that is, wind speed.

6. The method for multi-body dynamics modeling and numerical simulation of a ship-borne tethered balloon according to claim 1, characterized in that: The programming language is Python, and an API interface for secondary development in Adams is used.

7. A method for multi-body dynamics modeling and numerical simulation of a ship-borne tethered balloon as claimed in claim 6, characterized in that: The programming process includes: using the Python programming language, through the loop structure and Adams API, to establish the shape, initial position and orientation of each component in the system, define the kinematic pair relationship, calculate the sleeve force and external wind load, and simulate the wave load through spline curves and drive functions; at the same time, set the measurement parameters; (2) finally, run the generated .py file in Adams / View to perform calculations and solve, so as to evaluate the motion response of each component in the ship-borne tethered balloon system in real time.

8. A ship-borne tethered balloon multi-body dynamics modeling and numerical simulation method as claimed in claim 7, characterized in that: The measured parameters include the pitch angle of the balloon and the displacement of the cable.

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