Study On Submarine Voyage Training Simulator Based On HLA And Virtual Cabin Modeling

Considering current development of simulation technologies and practical request of Submarine Voyage Training Simulator, this dissertation put forward Submarine Voyage Training Simulator based on High Level Architecture (HLA). And key technologies have been studied. The main works are as follows:Firstly, Submarine Voyage Training Simulator based on HLA has been designed. And the configuration and function of every federate was studied. Furthermore, this dissertation studies the design and development process of virtual ocean environment federate based on real terrain data. Many technical problems have been solved, such as simulation of underwater space effect, simulation of offing effect, Large Area Database Management (LADBM), interaction with chart and so on. It satisfied the simulation of ocean environment with fidelity and real time. Perfect database of entity model has been founded at last.Then according to the real submarine cabin, Image Based Modeling technology was selected to create the virtual models of submarine cabin. This dissertation describes the study of image based modeling technology as the kernel. According to its practical flow, the modeling process is composed of three steps: image salient point detection and matching, difference affine transform registration based on EM algorithm, camera self-calibration and producing 3D model.Salient detection algorithm based on wavelet transform has been proposed that the salient points could be computed from the sum of wavelet coefficients at every scale. Comparing with other methods, this salient points detection algorithm is more spread. Responding to positional for matching points, the algorithm could be improved using matrix SVD analysis to achieve image matching based on correlation coefficients for salient points. Random sampling algorithm is introduced to estimate the fundamental matrix. And it wasnon-linear optimized. The epipolar line from this matrix has been estimated to remove the mismatched points. Using this method, the mismatched points could be removed by using epipolar line restriction.Registration algorithm for stereo image was developed based on EM (expectation maximization) algorithm which is used to compute the maximum likelihood estimator. Affine translation parameters for every pixel could be gotten from locally affine translation. The strategy of registration from coarse to fine was adopted by wavelet translation. The restriction in common use could be contented automatically. In order to improve the registration speed, matched points were used to compute first affine translation parameters globally. This approach reduced the cost time and improved the applicability to large parallax, rotation and scaling. The method of Edge-preserving visual perception modeling was used to reduce the number of needed registration. The simulation result shows that this registration algorithm is effective even to images with large parallax, rotation and scaling.The camera focal length was computed through analyze of Kruppa equation. And according to the character of essential matrix, camera external parameters could be gotten. So camera self-calibration was achieved. Space points could be computed using triangulation method. In order to minimize the error between predicted image points and corresponding matched points, bundle adjustment was adopted for optimization. By this method, the whole precision has been improved. Basing on space points, we realized submarine virtual cabin modeling.In the end, as the expending of the whole system, according to data filtering principle of the complex system, we suggested Hierarchical Federation Architecture (HFA). Through the analyse of Multi-Resolution Modeling method, Multiple Resolution Entity (MRE) modeling approach was chosen to realize the Multi-Resolution Modeling in Hierarchical Federation Architecture. This dissertation used mathematic formula to express the relationship among Multi-Resolution entities calculated the simulation cost. By this way wecompleted Submarine's Hierarchical Federation Architecture and realized Multi-resolution entity modeling of Submarine Voyage Training Simulator federation membership. Finally, the simulation process of the Submarine Voyage Training Simulator federation was discussed.