High-precision amphibious vehicle water movement simulation platform construction method and system

Abstract

The application discloses a high-precision amphibious vehicle water movement simulation platform construction method and system, relates to the technical field of vehicle simulation, and comprises the following steps: acquiring the propulsion system configuration and parameters of an amphibious vehicle, and calculating a thrust database by using the computational fluid dynamics principle; based on the rigid body and fluid dynamics theory, a water dynamics model and an environmental disturbance model are established; a high-precision water dynamics simulation program code is written and optimized, and an amphibious vehicle water movement simulation platform is developed in combination with the Unreal Engine. The method disclosed by the application can establish a high-precision amphibious vehicle water dynamics simulation platform.

Description

Technical Field

[0001] This application relates to the field of automotive simulation technology, and in particular to a method and system for constructing a high-precision amphibious vehicle water motion simulation platform. Background Technology

[0002] Amphibious vehicles are cross-domain platforms with excellent environmental adaptability and strong off-road capabilities, performing well in complex mission scenarios. Since their introduction in the 20th century, amphibious vehicles have been active in various military missions, becoming a military reserve force that many countries competed to develop. With the development of various technologies applied to amphibious vehicles, they are now widely used in civilian fields, participating in surveying and mapping, meteorological monitoring, transportation, and other industries. The research and development of amphibious vehicles faces challenges of long development cycles and high costs. Although real-vehicle testing can accurately assess dynamic performance, cost and efficiency issues often lead to the use of model testing to predict performance, which also prolongs the development cycle. Therefore, a high-precision aquatic dynamics simulation platform is crucial for predicting performance and for rapid design and parameter optimization.

[0003] Current research on amphibious vehicle simulation platforms largely employs simple models for motion simulation, neglecting to consider the impact of environmental disturbances on the amphibious vehicle's movement on water. These methods have the following limitations: 1) While model-based methods balance computational speed and real-time interaction, model mismatch can occur due to variations in model accuracy and parameters; 2) Ignoring environmental disturbances makes it difficult to simulate the different performance characteristics of amphibious vehicles under varying sea conditions and scenarios; 3) Low-order models may lack certain dimensions affecting the amphibious vehicle's movement on water, resulting in unreasonable overall vehicle dynamics. Summary of the Invention

[0004] The purpose of this application is to provide a method and system for constructing a high-precision amphibious vehicle water motion simulation platform, which can establish a high-precision amphibious vehicle water dynamics simulation platform.

[0005] To achieve the above objectives, this application provides the following solution:

[0006] Firstly, this application provides a method for constructing a high-precision simulation platform for the waterborne motion of amphibious vehicles, including:

[0007] Obtain vehicle information for amphibious vehicles; the vehicle information includes the system configuration of the amphibious vehicle's propulsion system and vehicle parameters.

[0008] Based on the system configuration of the propulsion system of the amphibious vehicle, and using the principles of computational fluid dynamics, the propulsion system of the amphibious vehicle is calculated to obtain the thrust database of the amphibious vehicle.

[0009] Based on the vehicle parameters of the amphibious vehicle, a water dynamics model of the amphibious vehicle is established based on rigid body dynamics and fluid dynamics theories.

[0010] An environmental disturbance model is established based on the theories of aerodynamics, wave mechanics, and ocean current dynamics.

[0011] Based on the aquatic dynamics model and environmental disturbance model of the amphibious vehicle, a high-precision aquatic dynamics simulation program code for the amphibious vehicle was written using an integrated development environment tool.

[0012] Based on computational fluid dynamics, with the goal of improving the accuracy of amphibious vehicle simulation, the high-precision amphibious vehicle water dynamics simulation program code was optimized to obtain the simulation code.

[0013] The optimized simulation code is combined with Unreal Engine to create a simulation platform for amphibious vehicles' waterborne motion within Unreal Engine.

[0014] Secondly, this application provides a high-precision amphibious vehicle waterborne motion simulation platform construction system, including:

[0015] The information acquisition module is used to acquire vehicle information of amphibious vehicles; the vehicle information includes the system configuration of the propulsion system and vehicle parameters of the amphibious vehicle.

[0016] The calculation module is used to calculate the propulsion system of the amphibious vehicle based on the system configuration of the amphibious vehicle's propulsion system and the principles of computational fluid dynamics, so as to obtain the thrust database of the amphibious vehicle.

[0017] The model building module is used to establish a hydrodynamic model of the amphibious vehicle based on the vehicle parameters and on rigid body dynamics and fluid dynamics theories.

[0018] The information acquisition module is used to establish environmental disturbance models based on aerodynamics, wave mechanics, and ocean current dynamics theories.

[0019] The code writing module is used to write high-precision amphibious vehicle hydrodynamic simulation program code based on the hydrodynamic model and environmental disturbance model of the amphibious vehicle, using integrated development environment tools.

[0020] The code optimization module is used to optimize the simulation code of the high-precision amphibious vehicle water dynamics simulation program code based on computational fluid dynamics, with the goal of improving the simulation accuracy of amphibious vehicles.

[0021] The platform building module is used to combine the optimized simulation code with Unreal Engine to create a simulation platform for amphibious vehicles' waterborne motion within Unreal Engine.

[0022] According to the specific embodiments provided in this application, the following technical effects are disclosed:

[0023] This application provides a method and system for constructing a high-precision amphibious vehicle water motion simulation platform. The method includes: obtaining detailed vehicle information of the amphibious vehicle, focusing on the system configuration and vehicle parameters of its propulsion system. Subsequently, based on the system configuration of the propulsion system, computational fluid dynamics principles will be applied to perform precise calculations on the propulsion system to construct and populate the thrust database of the amphibious vehicle. Next, based on detailed vehicle parameter data, rigid body dynamics and fluid dynamics theories will be integrated to construct an accurate aquatic dynamics model to simulate the dynamic behavior of the amphibious vehicle on the water surface. Based on theories of aerodynamics, wave mechanics, and ocean current dynamics, an environmental disturbance model will be constructed to capture and simulate the influence of various external factors on vehicle operation. Using integrated development environment tools, high-precision amphibious vehicle aquatic dynamics simulation program code will be written. The program will accurately simulate the vehicle's aquatic motion state based on the aforementioned aquatic dynamics model and environmental disturbance model. To further improve the accuracy of the simulation, the initial simulation program code will be optimized under the guidance of computational fluid dynamics. Finally, the optimized simulation code will be combined with Unreal Engine to construct an aquatic motion simulation environment for the amphibious vehicle on the Unreal Engine platform. The method of this application can achieve high-precision simulation of the motion state of amphibious vehicles in complex environments. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart illustrating a method for constructing a high-precision amphibious vehicle waterborne motion simulation platform, as provided in one embodiment of this application.

[0026] Figure 2 This is a schematic diagram of the framework for a method of constructing a high-precision amphibious vehicle water motion simulation platform according to an embodiment of this application.

[0027] Figure 3 This is a framework diagram of a solution calculation step provided in an embodiment of this application.

[0028] Figure 4This is a schematic diagram of the functional modules of a high-precision amphibious vehicle water motion simulation platform construction method system provided in an embodiment of this application. Detailed Implementation

[0029] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Example 1

[0032] like Figure 1 As shown, this embodiment provides a method for constructing a high-precision amphibious vehicle waterborne motion simulation platform, including:

[0033] Step 101: Obtain vehicle information of the amphibious vehicle; the vehicle information includes the system configuration of the propulsion system and vehicle parameters of the amphibious vehicle.

[0034] Step 102: Based on the system configuration of the amphibious vehicle's propulsion system, and using computational fluid dynamics principles, calculate the propulsion system of the amphibious vehicle to obtain the thrust database of the amphibious vehicle.

[0035] Step 103: Based on the vehicle parameters of the amphibious vehicle, establish a hydrodynamic model of the amphibious vehicle based on rigid body dynamics and fluid dynamics theory.

[0036] Step 104: Establish an environmental disturbance model based on aerodynamics, wave mechanics and ocean current dynamics theories.

[0037] Step 105: Based on the hydrodynamic model and environmental disturbance model of the amphibious vehicle, use an integrated development environment tool to write high-precision amphibious vehicle hydrodynamic simulation program code.

[0038] Step 106: Based on computational fluid dynamics, with the goal of improving the accuracy of amphibious vehicle simulation, the high-precision amphibious vehicle water dynamics simulation program code is optimized to obtain the simulation code.

[0039] Step 107: Combine the optimized simulation code with Unreal Engine to create an amphibious vehicle waterborne motion simulation platform within Unreal Engine.

[0040] Specifically, when executing step 101, the following can be done:

[0041] The obtained propulsion system configuration of the amphibious vehicle is a dual-thruster system configuration.

[0042] The vehicle parameters obtained can be the vehicle's size parameters, including but not limited to the vehicle's length, width, height, and weight.

[0043] Specifically, when executing step 102, the following can be done:

[0044] First, the system configuration of the propulsion system is determined, taking a common dual-propeller amphibious vehicle as an example; in order to accurately describe the performance of the propulsion system under different control variables, a database supporting the amphibious vehicle simulation platform is established.

[0045] Due to the complex shape of the pump system and the changes in the flow field caused by its motion, the hydrodynamic calculation and analysis are quite complex. The motion equations of viscous incompressible fluids are used to solve the external flow field of the propulsion pump:

[0046]

[0047] In the formula, ρ is the fluid density; v is the fluid velocity vector at time t; It is the Laplace operator; p is the pressure; F is the external force vector; the constant μ is the dynamic viscosity coefficient (dynamic viscosity μ).

[0048] Considering the circular pipe flow within the power system pipeline and the water jet problem under rotating flow domains such as pump impellers and guide vanes, a multi-coordinate sliding mesh model (MRF) combined with the RNG k-ε model is used for calculation. The RNG k-ε model is an improvement on the Standard k-ε model based on renormalization group theory, which considers the influence of the average strain rate in the rotating coordinate system.

[0049] The eddy viscosity of this model can be expressed as a function of the turbulent dissipation rate ε and the turbulent kinetic energy:

[0050]

[0051] The transport equation for the turbulent kinetic energy k is expressed as follows:

[0052]

[0053] The transport equation for the dissipation rate ε is expressed as follows:

[0054]

[0055] in, c1 = 1.42, c μ=0.085, c2=1.68, σ k =0.7179, σ ε =1.3.

[0056] The pump propulsion computational domain was divided using a structured mesh, resulting in four separate sections: the outlet section, the impeller region, the guide vane region, and the inlet flow channel section. The near-wall region of each section was defined using dimensionless wall distance. After calculating the values, the near-wall mesh structure arrangement is completed, with the first layer of mesh height on the nozzle wall set to approximately 0.35 mm. A sliding mesh model (MRF) based on a multi-moving reference frame is used to handle the rotating region. The inlet flow channel section is connected to the impeller region, and the impeller region is connected to the guide vane region via the Frozen Rotor interface. The guide vane region is connected to the vector nozzle section via a static-static interface.

[0057] The rotating flow domain is set as a rotating grid, while the conventional flow region is set as a stationary grid. The inlet channel is formed into an unstructured grid by appropriately increasing the number of nodes. Local grid refinement is performed in the inlet and outlet regions, and boundary layer grids are used in the flow channel and near-wall region of the pump shaft.

[0058] Finally, a safety factor-based analysis was conducted on the simulation reliability to ensure the database's credibility. Based on the commonly used control variables for dual-thrust amphibious vehicles—namely, the rotational speeds of the dual-side propulsion pumps and the opening degrees of the dual-side water gates—the propulsion force and torque generated by the amphibious vehicle's propulsion system in the three degrees of freedom (sway, roll, and bow) under different operating conditions were calculated, forming a propulsion system database to facilitate subsequent development. Depending on the type of amphibious vehicle propulsion required, the database can be extended to different types of propulsion systems, such as propellers, podded propulsion systems, and azimuth thrusters.

[0059] Specifically, when executing step 103, the following can be done:

[0060] The derivation of the kinematic equations of amphibious vehicles is usually based on the following two assumptions: the amphibious vehicle is a rigid body; and the NED coordinate system {n} is regarded as an inertial frame (ignoring the Earth's rotation speed).

[0061] According to assumption 2, we have:

[0062]

[0063] in and These are the velocity vectors of the rigid body's center of mass relative to the inertial frame {i} and the NED coordinate system {n}, respectively. and It is the angular velocity vector of the rigid body relative to the inertial frame {i} and the NED coordinate system {n}.

[0064] Then, according to Euler's first law, we can deduce that:

[0065]

[0066] in, It is an external force acting on the center of gravity. Let represent the time derivative in inertial frame {i}, and define dot as the derivative of the variable with respect to time. The S-function is the vector cross product. and These are the velocity vectors of the rigid body's center of mass relative to the inertial frame {i} and the NED coordinate system {n}, respectively. and It is the angular velocity vector of the rigid body relative to the inertial frame {i} and the NED coordinate system {n}.

[0067] The vector expression (6) above describes the translation about CG in the body coordinate system {b}, as shown in equation (7):

[0068]

[0069] The derivation of rotational dynamics is similar to the derivation process described above:

[0070]

[0071] In the formula, It is the external torque acting on the center of gravity, I g It is the rotational inertia matrix about the center of gravity. The vector expression (8) in {b} describes the rotational motion about CG:

[0072]

[0073] Based on the Newton-Euler equations for the translational and rotational motions of the center of gravity CG, we can obtain the equations of motion for CG:

[0074]

[0075] Among them, I 3×3 It is a 3×3 identity matrix, 0 3×3 It is a 3×3 zero matrix. For the dynamics of amphibious vehicles, this embodiment typically uses an arbitrary point CO as the origin of the motion system. The arbitrary point CO can utilize the geometric properties of the amphibious vehicle to simplify the number of certain parameters and reduce computational complexity.

[0076] The previously derived equations of motion for the center of gravity CG need to be transformed into equations of motion for CO.

[0077] CO and CG have the following vector relationship:

[0078]

[0079] in It is the position vector from CO to CG. The time derivative of the above equation in {n} can be written as equation (12):

[0080]

[0081] Based on assumption one, the rigid body satisfies:

[0082]

[0083] The velocities of CG and CO have the following relationship:

[0084]

[0085] Furthermore, according to assumption one, any two points on a rigid body have the same angular velocity: The following relationship can be obtained:

[0086]

[0087] in, It is the barycenter position vector in {b}. Defined as a transformation matrix.

[0088] According to the parallel axis theorem and rigid body dynamics, the following relationship exists:

[0089]

[0090]

[0091] Equation (10) is transformed into the equation of motion for point CO:

[0092]

[0093] Expanding and simplifying the first row of equation (18) yields the translation of CO:

[0094]

[0095] According to the Huygens-Steiner Theorem, for any origin o where CO lies, b Its inertia matrix I b satisfy:

[0096]

[0097] According to the Jacobi discriminant: a×(b×c)+b×(c×a)+c×(a×b)=0, we can obtain:

[0098]

[0099] but It can be represented as:

[0100]

[0101] The second line of the expansion (18) yields the rotational motion of CO:

[0102]

[0103] Based on the vector representation of the SNAME notation, by expanding the translational equation (19) and rotational equation (23) for CO, we can obtain the nonlinear 6-DOF rigid body motion equations:

[0104]

[0105] Rigid body dynamics can be expressed in vector form:

[0106]

[0107] Considering the rigid body dynamics of marine vehicles

[0108]

[0109] Among them, M RB It is the rigid body mass matrix, C RB It is the matrix of the Coriolis force and centripetal force of a rigid body, τ RB It is a generalized external force, including hydrodynamics, hydrostatics, wind and wave forces, and control forces. v represents the velocity and angular velocity in six degrees of freedom.

[0110] In fluid dynamics, it is generally assumed that the hydrodynamic forces and hydrodynamic moments acting on a rigid body can be linearly superimposed. The hydrodynamic forces consist of the following components: the additional mass M caused by the fluid inertia surrounding the vehicle. A Due to the rotation of the body coordinate system {b} relative to the northeast-northeast coordinate system {n}, the added mass produces a corresponding Coriolis and centripetal matrix C. A (v r The radiation-induced potential damping D caused by surface waves carrying energy. P Viscous damping τ is caused by surface friction, wave drift damping, vortex shedding, and lift / drag. visc The resulting nonlinear hydrodynamic mass-spring-damping force can be expressed as:

[0111]

[0112] τ hs =-g(η)-g0 (28).

[0113] Then, the nonlinear manipulation equations can be obtained:

[0114]

[0115] Generally, all degrees of freedom have coupling terms. However, in practical applications, some coupling terms are small enough that some less influential coupling terms are ignored in the model derivation. Furthermore, the following assumptions are applied in the model derivation: the amphibious vehicle is a rigid body; the ocean currents in the watershed environment are steady and irrotational; the amphibious vehicle is considered a box-shaped vessel, i.e., its waterline surface area remains constant; the amphibious vehicle is bilaterally symmetrical, i.e., XZ symmetrical; and the amphibious vehicle's sway motion is decoupled.

[0116] Wherein, the rigid body inertia matrix M RB Expanded to:

[0117]

[0118] Expand the Coriolis force and centripetal force matrices C in parametric form. RB (v):

[0119]

[0120] The inertia matrix M of the decoupled additional mass is given by equation (31). A :

[0121]

[0122] For a rigid body moving in an ideal fluid, the fluid dynamics Coriolis and the centripetal force matrix C A (v) can be M A Parameterization yields equation (33):

[0123]

[0124] The linear damping consists of potential damping and viscous damping, as shown in equation (34):

[0125]

[0126] D n (ν r The nonlinear damping matrix is ​​caused by quadratic damping and higher-order terms, as follows:

[0127]

[0128] Hydrostatics arise from the tilting of the amphibious vehicle due to disturbance, caused by the disruption of the balance between gravity and buoyancy, and can be expressed as follows:

[0129]

[0130] Where A wpThe amphibious vehicle's surface area is ▽, and its displacement when floating upright is GM. T For horizontal stability and high center of gravity, GM L For vertical stability and high center of gravity, L fo Let be the x-axis distance from the floating center CF to the origin CO at {b}.

[0131] At this point, the additional mass matrix M A The matrix C of the added mass Coriolis force and centripetal force A (v r ), the hydrodynamic damping matrix D(v r Both provide expressions in the form of hydrodynamic derivatives.

[0132] Based on the inertial matrix calculated from the amphibious vehicle itself and combined with the amphibious vehicle thrust database, the overall water dynamics model of the amphibious vehicle can be obtained.

[0133] Specifically, when executing step 104, the following can be done:

[0134] In the dynamics of amphibious vehicles, environmental forces typically include the forces and moments exerted on the vehicle by wind, waves, and ocean currents. In control systems, it is generally assumed that wind and wave disturbances can be superimposed. In general, environmental forces are highly nonlinear and exhibit additivity and multiplicative properties in the dynamic equations of motion.

[0135] Wind is defined as air moving relative to the Earth's surface. Let Vw and γw represent wind speed and angle of attack, respectively.

[0136] The relationship between the angle of attack γw and the wind speed Vw, wind direction βw, and heading ψ is:

[0137] γ w =ψ-β w -π (37).

[0138] Define relative wind speed Vrw and relative wind direction γrw:

[0139]

[0140] The component of relative wind speed is

[0141]

[0142] Define the wind force formula:

[0143]

[0144] In the formula, ρ a It is the density of air, H Fw and H Lw These are the heights above the waterline of the centroids of the orthographic projection region AFw and the lateral projection region ALw, respectively, and Loa is the total length of the amphibious vehicle. CX (γ rw ), C Y (γ rw ), C Z (γ rw ), C K (γ rw ), C M (γ rw ), C N (γ rw ) is the wind force coefficient related to the angle of attack.

[0145] Wave force can be considered as a slowly varying average component and an oscillating component. To study the impact of wave force on control systems, the first-order and second-order wave forces of the oscillating component are usually considered separately.

[0146] τ wave =τ wave1 +τ wave2 (41).

[0147] The wave force RAO is transformed into a transfer function form, and the wave spectrum is approximated using a linear filter:

[0148] τ wave1 =H s (s)n(s) (42).

[0149] Where H s (s)=Kdiag{h1(s),h2(s),h3(s),h4(s),h5(s),h6(s)} is the approximate diagonal matrix of the 6DOF wave spectrum S(ω), where K=diag{k1,k2,k3,k4,k5,k6} is the adjustable gain, and n(s) is zero-mean Gaussian white noise. This approximate model exhibits good performance and robustness in closed-loop feedback control systems. Taking a single degree of freedom as an example, the wave spectrum can be approximated by a second-order system:

[0150]

[0151] Where λ is the damping coefficient selected based on sea state and wave spectrum, ω e It represents the encounter frequency. Typically, k is defined as follows:

[0152] k=2λω e σ (44).

[0153] Where σ is a constant describing wave intensity. The energy spectral density function P of the approximate system is defined. h (ω).

[0154]

[0155] When ω=ωe At that time, P h S(ω) and S(ω) should achieve the same maximum value:

[0156]

[0157] In the formula, the value of λ is such that It can be established, or obtained by fitting the wave spectrum curve.

[0158] The second-order wave drift force is approximated by a random walk process: Where d is zero-mean Gaussian white noise.

[0159] Ocean currents are horizontal and vertical circulation systems of seawater generated by gravity, wind friction, and changes in water density at different parts of the ocean. The generalized velocity of an irrotational, steady ocean current is defined as: Where u c ,v c ,w c It is expressed in the body coordinate system {b}, that is The ocean current velocity in {n} can be expressed as:

[0160]

[0161] Since ocean currents are steady, the derivative of the above equation is 0, and we can obtain:

[0162]

[0163] Easy to obtain:

[0164]

[0165] The calculation of relative velocity is defined as follows:

[0166]

[0167] Formula (52) can be obtained from the following formula (51):

[0168]

[0169]

[0170] Then, by substituting the whole vehicle dynamics model, we can obtain the dynamics model under the influence of ocean currents, as shown in equation (53):

[0171]

[0172] Specifically, when executing step 105, the following can be done:

[0173] Based on the amphibious vehicle water dynamics model formula derived in steps 103 and 104, this embodiment has written the corresponding C++ code. The solution and calculation process is detailed in [link to C++ code]. Figure 3 The code first defines the generalized coordinates and inputs initial parameter values. Then, based on the amphibious vehicle's state and control parameters at the current time point, it accurately calculates the propulsion force generated by the propulsion system, the force induced by the rigid body inertia matrix, and the fluid damping force. Next, it simulates given environmental parameters, including wind, waves, and currents, to evaluate the impact of these factors on the amphibious vehicle's motion state. Subsequently, it substitutes the calculated forces and moments into the amphibious vehicle's dynamics model to solve for the generalized acceleration. Then, it uses the fourth-order Runge-Kutta method for integration to predict and calculate the state parameters at the next time point, while also considering the control parameters provided by the interactive system. The calculation results are fed back into the calculation process as the initial conditions for the next iteration, and this process is repeated for subsequent time points. Through this process, this embodiment successfully developed a real-time, interactive, high-precision amphibious vehicle water dynamics simulation program code, achieving accurate simulation and analysis of the amphibious vehicle's water motion state.

[0174] Specifically, when executing step 106, the following can be done:

[0175] Based on computational fluid dynamics (CFD) methods, the model was optimized iteratively. First, an amphibious vehicle model was established. Then, structured meshes of varying densities were created based on the complexity of different structural regions. Appropriate turbulence and free surface models were selected, and the external flow field of the amphibious vehicle was solved using the finite volume method. Numerical calculations were performed for specific operating conditions of the amphibious vehicle, such as straight-line navigation, turning, and Z-shaped maneuvers. The results were compared and analyzed with the dynamic simulation results from step 3. The dynamic model parameters in the simulation were adjusted to make the simulation results as close as possible to the results of the fluid dynamics numerical calculations. The above steps were repeated, iterating the model parameters step by step, and finally controlling the residual of the selected comparative evaluation index to within 1%, thus completing the optimization of the amphibious vehicle simulation dynamic model parameters.

[0176] Specifically, when executing step 107, the following can be done:

[0177] The final optimized code was combined with Unreal Engine to build a real-time, interactive, high-precision amphibious vehicle hydrodynamics simulation platform.

[0178] A basic model of the amphibious vehicle was built in Unreal Engine, including the vehicle body, running gear, propulsion system, wave deflectors, tail flaps, and other components. A complete amphibious vehicle model was then assembled based on these components. The optimized dynamics simulation code obtained in step 105 was combined with the tracked vehicle model in Unreal Engine. Real-time simulation software for the amphibious vehicle was built using the UE4 engine. The simulation software calculated the real-time motion state of the amphibious vehicle through an integrated environment system, vehicle model, dynamics model, and control system. The motion state and scene interaction of the amphibious vehicle were rendered and output using the UE4 engine, visualizing the simulation results so that users could intuitively view them. This formed the overall framework of a self-developed, real-time interactive, animated amphibious vehicle waterborne simulation platform.

[0179] User-friendliness was considered during the development process, and a corresponding user interface was developed based on the Qt platform, including basic functions such as amphibious vehicle motion control commands, component parameter modification, and motion process display. External data interfaces were provided during development to enable the simulation platform to support the operation of decision-aware planning and control algorithms, ultimately constructing a fully autonomous, real-time, interactive, and high-precision amphibious vehicle hydrodynamics simulation platform.

[0180] Example 2

[0181] like Figure 4 As shown, this embodiment provides a high-precision amphibious vehicle waterborne motion simulation platform construction system, including:

[0182] The information acquisition module 401 is used to acquire vehicle information of the amphibious vehicle; the vehicle information includes the system configuration of the propulsion system and vehicle parameters of the amphibious vehicle.

[0183] The calculation module 402 is used to calculate the propulsion system of the amphibious vehicle based on the system configuration of the amphibious vehicle's propulsion system and the principle of computational fluid dynamics, so as to obtain the thrust database of the amphibious vehicle.

[0184] The model building module 403 is used to establish a water dynamics model of the amphibious vehicle based on the vehicle parameters of the amphibious vehicle and on the theories of rigid body dynamics and fluid dynamics.

[0185] Information acquisition module 404 is used to establish an environmental disturbance model based on aerodynamics, wave mechanics and ocean current dynamics theories.

[0186] The code writing module 405 is used to write high-precision amphibious vehicle hydrodynamic simulation program code based on the hydrodynamic model and environmental disturbance model of the amphibious vehicle, using integrated development environment tools.

[0187] The code optimization module 406 is used to optimize the simulation code of the high-precision amphibious vehicle water dynamics simulation program code based on computational fluid dynamics, with the goal of improving the simulation accuracy of amphibious vehicles.

[0188] Platform building module 407 is used to combine the optimized simulation code with Unreal Engine to create a simulation platform for amphibious vehicle water movement in Unreal Engine.

[0189] The platform construction module specifically includes:

[0190] The initial model building submodule is used to build the initial model of the amphibious vehicle simulation platform based on Unreal Engine; the initial model includes the vehicle body shell, tires and suspension.

[0191] The platform construction submodule is used to combine the optimized simulation code with the initial model of the amphibious vehicle simulation platform in Unreal Engine, and use Unreal Engine to visualize the calculation results of the optimized simulation code to obtain the amphibious vehicle dynamics simulation platform.

[0192] In summary, this application has the following technical effects:

[0193] The simulation platform established in this application improves the accuracy and reliability of simulation by combining computational fluid dynamics and dynamic model optimization. It also supports complex three-dimensional motion analysis and multi-parameter adjustment, and has an environmental factor editing interface and a user-friendly visual interactive interface, which enhances the applicability and scalability of the model.

[0194] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0195] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for constructing a high-precision amphibious vehicle waterborne motion simulation platform, characterized in that, include: Obtain vehicle information for amphibious vehicles; the vehicle information includes the system configuration of the amphibious vehicle's propulsion system and vehicle parameters; Based on the system configuration of the propulsion system of the amphibious vehicle, and based on the principles of computational fluid dynamics, the propulsion system of the amphibious vehicle is calculated to obtain the thrust database of the amphibious vehicle. Based on the vehicle parameters of the amphibious vehicle, and on the basis of rigid body dynamics and fluid dynamics theory, a water dynamics model of the amphibious vehicle is established. An environmental disturbance model is established based on aerodynamics, wave mechanics, and ocean current dynamics theories. Based on the above-mentioned amphibious vehicle's hydrodynamics model and environmental disturbance model, a high-precision amphibious vehicle hydrodynamics simulation program code was written using an integrated development environment tool. Based on computational fluid dynamics, with the goal of improving the accuracy of amphibious vehicle simulation, the high-precision amphibious vehicle water dynamics simulation program code was optimized to obtain the simulation code. The optimized simulation code is combined with Unreal Engine to create a simulation platform for amphibious vehicles' water sports within Unreal Engine. Based on the vehicle parameters of the amphibious vehicle, and using rigid body dynamics and fluid dynamics theories, a hydrodynamic model of the amphibious vehicle is established, specifically including: The amphibious vehicle is treated as a rigid body, and the NED coordinate system {n} is regarded as an inertial frame. The velocity vector of the amphibious vehicle and the angular velocity vector of the amphibious vehicle relative to the NED coordinate system are determined. Based on the velocity vector and angular velocity vector, Euler's first law is used to calculate the external force acting on the center of gravity of the rigid body; the specific formula for calculating the external force acting on the center of gravity of the rigid body is as follows: ； in, It is an external force acting on the center of gravity. The S-function represents the time derivative in inertial frame {i}, and is the vector cross product. and These are the velocity vectors of the rigid body's center of mass relative to the inertial frame {i} and the NED coordinate system {n}, respectively. and It is the angular velocity vector of the rigid body relative to the inertial frame {i} and the NED coordinate system {n}; Based on the vehicle parameters of the amphibious vehicle, and using rigid body dynamics and fluid dynamics theories, a hydrodynamic model of the amphibious vehicle is established, specifically including: According to the formula Calculate the motion of the center of mass of a rigid body; in, It is a 3×3 identity matrix. It is a 3×3 zero matrix. It is the external torque acting on the center of gravity of a rigid body. It is the rotational inertia matrix of the rigid body's center of gravity; , ; After calculating the motion of the rigid body's center of mass, the following is also included: Based on the equation of motion of the rigid body's center of mass, and using the formula... To determine the motion of any point on a rigid body; Where H is the transformation matrix, Let be the rigid body inertia matrix with respect to the center of gravity CG. Let the position vector be the center of gravity. and These are the linear velocity and angular velocity of the rigid body in the body coordinate system, respectively. and These are the linear acceleration and angular acceleration of the rigid body in the body coordinate system, respectively, and f and m are the external force and external torque.

2. The method for constructing a high-precision amphibious vehicle waterborne motion simulation platform according to claim 1, characterized in that, The propulsion system of the amphibious vehicle is a dual-thruster system configuration.

3. The method for constructing a high-precision amphibious vehicle waterborne motion simulation platform according to claim 2, characterized in that, Based on the system configuration of the amphibious vehicle's propulsion system, and using computational fluid dynamics principles, calculations are performed on the amphibious vehicle's propulsion system to obtain a thrust database for the amphibious vehicle, specifically including: Based on the system configuration of the propulsion system of the amphibious vehicle, the external flow field of the propulsion pump is solved using the kinematic equations of viscous incompressible fluid; the specific kinematic equations of the viscous incompressible fluid are as follows: ； in, ρ Let be the fluid density, v be the fluid velocity vector at time t, ∇ be the Laplace operator, p be the pressure, F be the external force vector, and μ be the dynamic viscosity coefficient.

4. The method for constructing a high-precision amphibious vehicle waterborne motion simulation platform according to claim 3, characterized in that, Based on the system configuration of the amphibious vehicle's propulsion system, and using computational fluid dynamics principles, calculations are performed on the amphibious vehicle's propulsion system to obtain a thrust database for the amphibious vehicle. Specifically, this also includes: Based on the system configuration of the propulsion system of amphibious vehicles, a multi-coordinate system sliding mesh model and RNG are adopted. k-ε The model solves for eddy viscosity; the specific equations for solving eddy viscosity are as follows: ； in, k For turbulent kinetic energy, ε For turbulent dissipation rate, c μ =0.

085.

5. The method for constructing a high-precision amphibious vehicle waterborne motion simulation platform according to claim 1, characterized in that, The optimized simulation code is combined with Unreal Engine to create an amphibious vehicle waterborne motion simulation platform within Unreal Engine, specifically including: An initial model of an amphibious vehicle simulation platform was built using Unreal Engine; the initial model includes the vehicle body shell, tires, and suspension. The optimized simulation code is combined with the initial model of the amphibious vehicle simulation platform in Unreal Engine, and the calculation results of the optimized simulation code are visualized using Unreal Engine to obtain the amphibious vehicle dynamics simulation platform.

6. A high-precision amphibious vehicle waterborne motion simulation platform construction system, used to implement the high-precision amphibious vehicle waterborne motion simulation platform construction method described in claim 1, characterized in that, include: The information acquisition module is used to acquire vehicle information of amphibious vehicles; the vehicle information includes the system configuration of the propulsion system and vehicle parameters of the amphibious vehicle. The calculation module is used to calculate the propulsion system of the amphibious vehicle based on the system configuration of the amphibious vehicle's propulsion system and the principles of computational fluid dynamics, so as to obtain the thrust database of the amphibious vehicle. The model building module is used to establish a water dynamics model of the amphibious vehicle based on the vehicle parameters of the amphibious vehicle and on the theories of rigid body dynamics and fluid dynamics. The information acquisition module is used to establish an environmental disturbance model based on aerodynamics, wave mechanics, and ocean current dynamics theories. The code writing module is used to write high-precision amphibious vehicle hydrodynamic simulation program code based on the hydrodynamic model and environmental disturbance model of the amphibious vehicle, using integrated development environment tools. The code optimization module is used to optimize the simulation code of the high-precision amphibious vehicle water dynamics simulation program code based on computational fluid dynamics, with the goal of improving the simulation accuracy of amphibious vehicles. The platform building module is used to combine the optimized simulation code with Unreal Engine to create a simulation platform for amphibious vehicles' waterborne motion within Unreal Engine.

7. The high-precision amphibious vehicle waterborne motion simulation platform construction system according to claim 6, characterized in that, The platform building modules specifically include: The initial model building submodule is used to build the initial model of the amphibious vehicle simulation platform based on Unreal Engine; the initial model includes the vehicle body shell, tires and suspension; The platform construction submodule is used to combine the optimized simulation code with the initial model of the amphibious vehicle simulation platform in Unreal Engine, and use Unreal Engine to visualize the calculation results of the optimized simulation code to obtain the amphibious vehicle dynamics simulation platform.

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