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基于VisualC++,Vega Prime,Multigen Creator和Matlab对子母型自治水下航行器(Autonomous Underwater Vehicle,AUV)回收控制视景仿真系统进行了开发研究。通过建立子/母AUV的动力学方程,给出了一种基于主-从运动状态同步思想的母AUV自主回收子AUV的控制方案。依据该方案,利用Multigen Creator创建了子/母AUV的实体模型,并由Vega Prime导入模型进行场景配置,以Matlab作为后台对子/母AUV的动力学方程进行实时计算,然后,采用VisualC++平台进行综合集成,得到子母型AUV回收控制视景仿真系统,并通过实例演示进行了验证。 相似文献
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针对自主水下机器人(Autonomous Underwater Vehicle,AUV)在回收过程中的组合导航精度问题,提出了一种改进的高斯距离迭代法及改进的自适应卡尔曼滤波算法(Adaptive Kalman Filter,AKF).基于AUV回收对接系统,研究并建立了针对惯导SINS、超短基线USBL、多普勒计程仪DVL和深度计的基于斜距的组合导航模型.通过对SINS/USBL/DVL/深度计组合导航量测信息误差特性分析,设计了改进的基于斜距的SINS/USBL/DVL/深度计组合导航模型;针对该模型突出的滤波发散问题,设计了基于滤波收敛性判据和强跟踪滤波思想改进的AKF滤波算法进行有机融合.仿真结果表明,此研究使实际AUV系统具有更高的滤波精度和可靠性. 相似文献
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为深入理解和分析电站凝结水泵性能,采用计算流体力学方法(CFD)对其内部复杂的三维流场进行了数值模拟与分析.首先,建立了某三级凝结水泵各部件几何模型,并对其进行网格划分.通过求解RANS方程对凝结水泵内部三维流场进行数值求解,湍流流动采用SST模型进行模拟.计算得到该泵若干工况下的扬程和功率等性能参数和泵内部流动特征,计算结果与试验数据吻合很好.模拟结果及分析表明:采用CFD方法模拟结构复杂的凝结水泵内部流动和进行性能预报是可行的.通过内流场分析还发现导叶体等部件的设计有可改进之处. 相似文献
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为了满足水下航行远航程和长时间的要求,远航程自主水下航行器(AUV)采用的是以SINS导航为主、卫星导航定期修正的方式,以提高导航的精度和可靠性.设计一种采用GPS卫星定位导航模拟器、GPS接收机、惯性测量器件(IMU)和实时仿真计算机构成的采用SINS/GPS组合导航方式的AUV导航半实物仿真系统,并对该系统的硬件接口设计、算法和软件开发进行了论述.所开发的系统通过外部的线运动补偿实现了惯性导航系统的完整计算,通过时间同步策略解决了各导航子系统的并行同步问题.部分仿真试验的结果表明,所设计的半实物仿真系统方案可行,可用于更高置信度的AUV组合导航仿真实验. 相似文献
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基于二维N-S方程,利用有限差分数值离散方法,对激波诱导异质气体界面失稳的现象进行了数值模拟,与文献中实验结果和计算结果进行了定性比较,并进一步分析了整个流动的非定常动态变化特性和非线性特征.研究表明,本文数值模拟的非定常流场图谱与文献中的实验结果和数值结果吻合较好;数值结果捕捉到了六氟化硫界面的演变过程及流场中复杂的波系结构. 相似文献
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研究高温空气的不同物理模型对载人飞船返回舱等离子体鞘电子密度的影响 ,包括热力平衡的化学非平衡模型与热力、化学都是非平衡的模型的比较 ,以及七组元模型与十一组元模型的比较。采用NND格式和时间预处理技术 ,得到了非平衡流全NS方程的时间渐近解 ,计算了载人飞船等离子体鞘电子密度的典型结果。与飞行试验及有关文献数值计算结果之比较表明 ,本文的计算结果是可信的 相似文献
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在某新型远程自主水下航行器(AUV)的几何空间坐标方程和运动学数学模型的基础上,根据该新型AUV的组成和物理特性完成其在虚拟场景中的三维模型构建。该模型不仅可以准确反映AUV的各项物理参数和真实尺寸,而且可以在数学仿真的同时实现模型仿真的可视化,更加直观、生动和实时地反映AUV的位姿状态以及巡航、悬停和目标跟踪等过程。 相似文献
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针对无人自主水下航行器(Autonomous Underwater Vehicle, AUV)在复杂海战场环境中路径规划时环境模型复杂、约束条件多的情况,建立了包括战场地形、敌方威胁、障碍物和海流场等在内的比较完善的海战场环境模型。以AUV航行时间、威胁时间最短为优化目标,给出了一种基于振荡型入侵野草优化(Invasive Weeds Optimization, IWO)算法的AUV全局路径规划方法,并分别与标准IWO算法、全振荡型IWO算法以及粒子群算法等三种路径规划算法比较。仿真结果表明,所提方法具有较强的寻优能力和鲁棒性,可在复杂海战场环境下为AUV高效地规划出满足性能要求的航行路径。 相似文献
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采用非线性动力学方法对液体火箭发动机非线性高频燃烧不稳定工作过程进行了研究。气相控制方程组用欧拉坐标系下的Navier Stokes方程组描述,液相控制方程组在Lagrangian坐标系下进行描述,气、液两相作用通过方程组的源项互相耦合。用高压蒸发理论对火箭发动机喷雾过程进行了描述。采用计算燃烧学的方法对发动机燃烧室内的湍流两相燃烧过程的稳定燃烧状态和高频不稳定燃烧现象进行了数值模拟。通过分析和讨论,得出了火箭发动机高频不稳定燃烧过程的波动过程类似于奇异吸引子的结论。 相似文献
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《防务技术》2020,16(2):341-347
One-dimensional simulations with a detailed hydrogen-oxygen reaction mechanism have been performed to investigate detonation phenomenon in a combustion light gas gun (CLGG). Convection fluxes of the Navier-Stokes equations are solved using the WAF (weighted average flux) scheme HLLC Riemann solver. A high resolution fifth-order WENO scheme for the variable extrapolation at the volume interface and a fourth-order Runge-Kutta scheme for the time advancement are used. Validation tests of the stoichiometric hydrogen-oxygen deflagration to detonation transition process shows good agreement between the computed results and the analytical and documented solutions, demonstrating the reliability on the detonation simulation of the current scheme. Simulation results of the interior ballistic process of the CLGG show that the flame propagation experiences three distinct stages. The blast detonation wave causes a high-pressure shock and hazardous oscillations in the chamber and makes the projectile accelerate with fluctuations, but has only a small improvement to the muzzle velocity. 相似文献
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The simulation of the artillery interior and intermediate ballistics problem is performed to investigate the influence of a gas dynamics device, muzzle brake, on the muzzle hazard phenomena, such as flash and blast waves. The correlation of the chemical reactions with the characteristics of the muzzle flow field is analyzed by the simulation for a further understanding of the secondary combustion phenom-enon of the muzzle flow. The novel structure of muzzle flow caused by the muzzle brake is presented by the simultaneous solution of the interior ballistics model and multi-species Navier-Stokes equations in order to analyze the influence of the muzzle brake structure on the chemical reactions. The secondary combustion of the muzzle flow due to the oxygen-supplement chemical reactions is obtained by the chemical reaction kinetic model. The interaction of the blast waves released from the muzzle brake is illustrated in detail and the mechanism of the formation of muzzle flash is analyzed. This research provides a reference for the studies on the suppression of the muzzle flash. 相似文献
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采用Osher Chakraverthy的TVD格式、Baldwin Lomax湍流模型和LU SSOR隐式方法求解了完全NS方程 ,数值模拟了三维高超音速绕流与横向喷流干扰流场。并在高超音速炮风洞中开展了喷流实验研究 ,对该喷流流场的数值计算结果进行实验验证 相似文献
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《防务技术》2020,16(3):651-661
At present, simultaneous localization and mapping (SLAM) for an autonomous underwater vehicle (AUV) is a research hotspot. Aiming at the problem of non-linear model and non-Gaussian noise in AUV motion, an improved method of variance reduction fast simultaneous localization and mapping (FastSLAM) with simulated annealing is proposed to solve the problems of particle degradation, particle depletion and particle loss in traditional FastSLAM, which lead to the reduction of AUV location estimation accuracy. The adaptive exponential fading factor is generated by the anneal function of simulated annealing algorithm to improve the effective particle number and replace resampling. By increasing the weight of small particles and decreasing the weight of large particles, the variance of particle weight can be reduced, the number of effective particles can be increased, and the accuracy of AUV location and feature location estimation can be improved to some extent by retaining more information carried by particles. The experimental results based on trial data show that the proposed simulated annealing variance reduction FastSLAM method avoids particle degradation, maintains the diversity of particles, weakened the degeneracy and improves the accuracy and stability of AUV navigation and localization system. 相似文献