Design Of Ploar Region Training Platform Of Underwater Vehicle Based On Virtual Simulation

The polar ocean contains a lot of natural resources and has important economic and military value,because of this,the polar regions have important strategic significance for our country.High-precision,high-reliability polar navigation equipment is indispensable.Among them,the submarine is of great significance to the exploration of the environment and resource extraction in the polar region.Therefore,the safety and stability of the polar navigation of the underwater vehicle become the top priority.However,there are many factors affecting navigation safety in the polar environment,including sea ice,geomagnetism,and low temperature.Because of these factors,there are restrictions on real ships entering the polar regions for equipment verification,and then the operation training of personnel cannot be implemented.In response to this demand,the paper adopts the method of designing a virtual submarine polar region simulation training platform to realize the equipment verification of polar region equipment and the operation training of underwater vehicle operators in the middle and low latitude regions.The main research work is as follows:First of all,in order to simulate the real environment of the polar region,a digital twin model of the polar ocean environment was designed and constructed on Unreal Engine 4(which will be replaced by UE4 later in the paper)based on the data of the polar ocean environment,and the waves in the polar region were simulated.The wave simulation method based on 8Gerstner wave solves the problem of low fidelity of traditional wave simulation;U and V parameter channels are added to the wave blueprint and upper wave tiles are added to suppress the wave distortion due to the nonlinear changes of extra normal offset.Generated polar seabed terrain based on SRTM15+ terrain data and multi-beam terrain data.Suppressed the terrain distortion caused by insufficient resolution and accuracy of terrain data by filtering and interpolation methods;Improved method of lighting and add geometrical details and normal to enrich the terrain details of the polar region.Analyzed the environmental characteristics of polar region terrain,sea ice,and geomagnetism.Secondly,in order to reduce the burden on system memory and hardware when loading polar terrain data,the paper compresses the terrain data based on the Huffman algorithm;the paper designs a dynamic terrain generation algorithm based on the Delaunay algorithm,which is based on the traditional Delaunay algorithm.The triangular proximity table is added to the above,and the multi-process execution is used.The terrain generation speed is increased by16.1% compared to traditional terrain generation method;in order to further reduce the memory usage during data loading,a terrain block loading algorithm based on dynamic level streaming is designed,and further Reduced memory footprint,compared to traditional loading methods,the memory footprint is reduced by 45.2%.Thirdly,the traditional ocean current simulation mostly uses the second-order Markov process to replace ocean currents.The ocean current does not interfere with the motion of the underwater vehicle accurately.In order to further improve the authenticity of the simulated ocean environment in the polar region,this paper uses the FVCOM ocean numerical model as the initial ocean current input and design a high-precision ocean current model construction algorithm based on the EM algorithm in the polar region,which realizes the dynamic switching of ocean current direction;realizes the three-dimensional visualization of sea ice in the polar region.Finally,without additional control,the attitude of the underwater vehicle is disturbed by waves and ocean currents,and the sudden changes in attitude are not enough to meet the navigation needs.This paper designs an underwater vehicle attitude control algorithm based on the LOS algorithm,Suppressed the sudden change of the attitude of the submarine,and reduce the sudden change of the attitude by 89.1%.Designed the human-computer interaction system of the virtual underwater vehicle in UE4 to improve the immersion and authenticity of the underwater vehicle simulation control system,including the user interface of the underwater vehicle,multiple observation angles,and full-degree-of-freedom observation mode;To verify the confidence of the underwater vehicle simulation training platform,the underwater vehicle visual simulation was performed under multiple sea conditions,and the design and construction of the semi-physical platform was completed.The usability of the virtual underwater vehicle simulation training platform is verified through simulation.