渔船模拟器中拖网和围网作业的仿真研究

发布时间：2018-02-02 04:47

本文关键词： 渔船模拟器渔具系统水动力模型数值模拟 GPU加速　出处：《大连海事大学》2016年博士论文　论文类型：学位论文

【摘要】：利用渔船模拟器进行渔船船员的培训,可降低风险、节省成本、缩短培训周期、提高受训人员的综合操控能力和实际分析能力。为进行渔船模拟器中双船拖网和单船围网作业过程的动态仿真,本文基于集中质量法分别建立了双船拖网和单船围网渔具系统的高可信度水动力数学模型,通过采用高效的精细积分算法求解庞大的非线性微分方程组和基于CUDA的GPU(Graphic Process Unit)并行计算加速技术保证了所建立数学模型解算的实时性,考虑渔船与渔具系统的耦合,搭建了双船拖网和单船围网作业的仿真系统,从而为渔船模拟器的开发奠定了坚实的基础。高可信度水动力数学模型是双船拖网和单船围网作业过程动态仿真的基础。本文基于集中质量法提出一种双船拖网和单船围网渔具系统数学模型的建模方法。在建模过程中,将渔具系统分为曳纲(括纲)和网具系统两部分,分别建立其水动力模型,并通过边界条件实现了二者的耦合；将渔具系统视为一系列无质量弹簧相连的质量点集合,将结节视为球体,目脚视为圆柱体,所有外力均作用于质量点上,根据牛顿第二定律分别建立各质量点的水动力数学模型；在此基础上,考虑渔船与渔具系统间的耦合,从而可进行双船拖网和单船围网作业的动态仿真。将仿真结果与模型试验结果进行比较和分析,验证了模型的有效性。渔具系统由大量有弹性的柔性体组成,使用集中质量法对其进行数字离散后,构成了数目巨大的非线性微分方程组,且该非线性微分方程组稳定求解的时间步长受到柔性体刚度的限制。高效的数值解法对保障其水动力模型求解的稳定性及提高模型解算的效率是十分必要的。本文提出了一种基于精细积分法的渔具系统水动力模型的数值解法,运用指数矩阵的2N类算法及函数矩阵的分部积分法对网具系统的非线性方程进行数值求解。与传统渔具系统数值解法相比,该数值方法精度较高,计算效率高,对采用集中质量法建模的方程求解具有普适性。大型拖网及围网系统的物理节点数量通常达百万级别,即便利用网目合并技术对网衣进行简化处理,使用上述数值解法仍不能保证水动力模型解算的实时性。本文基于CUDA的GPU并行加速技术进行渔具系统水动力数学模型的解算,通过在全局内存中开辟数组,存储上一帧所有质量点的位置,通过线程索引查找相连节点位置计算张力,网具系统中所有结节和目脚的模型解算采用并行执行。实验结果表明：利用GPU并行解算在保证计算精度的前提下能有效提高计算效率,保证了大型拖网及围网系统动态仿真的实时性。最后,利用场景管理软件OSG(OpenSceneGraph)实现了双船拖网和单船围网作业过程的三维可视化,并与航海模拟器相结合,初步实现了渔船模拟器中双船拖网和单船围网操作模块的功能。本文研究对提高水下柔性体的仿真效果、推进渔船模拟器产品研发具有现实意义,可为渔船模拟器的进一步研究提供理论依据和技术支撑。
[Abstract]:By using the fishing crew fishing simulator training, can reduce the risk, save the cost, shorten the training cycle, improve the comprehensive ability to control the trainees and the actual analysis. Dynamic simulation of double boat trawl fishing simulator and ship seining process, this paper is based on the lumped mass method were established and two boat trawler single boat Seine fishing gear system with high reliability of hydrodynamic mathematical model, through the use of highly precise integration algorithm for solving large nonlinear differential equations based on CUDA and GPU (Graphic Process Unit) parallel real-time calculation speed technology to ensure the mathematical model calculation, considering the coupling of fishing boats and fishing gear system, set up simulation system of double and single boat trawl fishing, thus laying a solid foundation for the development of fishing simulator. High reliability hydrodynamic mathematical model is a double boat The basic network and single ship seining process dynamic simulation. The modeling method of lumped mass method and presents a double boat trawl and single boat Seine fishing gear system based on mathematical model. In the process of modeling, the gear system is divided into uarp (including class) two and the net system, and respectively establish its hydrodynamic model, and realized the coupling of the two through the boundary conditions; fishing gear system as a series of springs without mass connected to the quality of the collection, the nodules as sphere, mesh feet as a cylinder, all external forces are applied at the quality point, the hydrodynamic mathematical model of the quality points are established according to the second law of Newton; on this basis, considering the coupling between fishing boats and fishing gear system, dynamic simulation can be used for two boat trawler and single boat seiner. The simulation results and the experimental results were compared and analyzed to verify the validity of the model. Fishing gear system consists of a large number of flexible elastic components, the use of digital discrete lumped mass method, a set of nonlinear differential equations in large numbers, and the nonlinear differential equations for solving the stable time step by the flexible body stiffness limit. Efficient solution to guarantee the stability of numerical hydrodynamic model and to improve the efficiency of model calculation is very necessary. This paper presents a numerical solution of the hydrodynamic model of gear system based on precise integration method, the numerical solution of nonlinear equation integral method by using 2N algorithm and function matrix exponential matrix of the gear system. Compared with the traditional numerical method of fishing gear system. The numerical methods with high accuracy, high calculation efficiency and universality of the equations of lumped mass method. A large number of physical nodes and fence system trawl Usually one million level, even on the net is simplified by using mesh merging technique, using the numerical method still can not guarantee real-time dynamic model of water solution. The CUDA GPU parallel accelerating technology of fishing gear hydrodynamic mathematical model solution based on, by opening up in the global memory array, a frame of all position the quality of the storage, index lookup nodes connected by thread tension position calculation system, net all nodules and eye foot model are solved by parallel execution. The experimental results show that parallel computation in ensuring the computational accuracy can effectively improve the computing efficiency by GPU, real-time and dynamic system of large trawl net the simulation. Finally, using the scene management software OSG (OpenSceneGraph) to realize 3D visualization of two boats trawl and single boat seiner process, and with the navigation simulator. Combined, initially realized the two ships in fishing simulator trawl and single boat Seine operation modules. The simulation results in this paper to improve the water body flexible, has practical significance to promote fishing simulator product development, further study can be used as a fishing simulator to provide theoretical basis and technical support.

【学位授予单位】：大连海事大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：U661.74

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