基于粒子系统的火箭飞行特效仿真的研究

基于粒子系统的特效仿真是运载火箭飞行可视化仿真中的重要环节.本文针对运载火箭飞行仿真中喷射火焰实时仿真难于实现的问题,对基于粒子系统的火箭喷射火焰动态模拟进行了研究.通过对火箭喷射火焰细节、特点的分析,建立了粒子系统的数据结构.详细介绍了算法的具体细节和关键技术,其中包括粒子的初始化和粒子发射器的初始化、粒子系统的更新.最后利用Billboard技术、OpenGL纹理映射等计算机技术实现了具有较强真实感的火箭飞行喷射火焰的实时仿真.     

基于EnSight的数值仿真可视化系统设计与实现

为提高数值仿真后处理的效率,满足分布式仿真系统在数值仿真数据方面的可视化需求以及实现仿真试验过程的可视化,基于EnSight的二次开发开展数值仿真可视化系统设计.提出基于Qt开发框架的系统集成、基于Python的功能开发和基于Socket的通信接口开发,实现具有协同功能的数值仿真可视化系统.该系统采用模板化技术实现带场景的可视化和快速后处理功能.给出系统架构、组成、实现效果及应用案例.应用结果表明：该系统能够适应多仿真类型结果分析,实现动态仿真过程的协同可视化.     

机载运载火箭飞行程序设计及仿真

关于载机和运载火箭分离程序的优化设计问题,为实现机载运载火箭飞行程序设计保证运行姿态稳定性,并进一步提高系统模型的可信度,在传统分析方法的基础上.考虑了箭机分离过程中载机与火箭飞行程序之间的相互作用,建立了载机与运载火箭的分离多体动力学模型,研究了影响飞行姿态的主要因素.开发了集仿真计算、三维视景演示和可视化结果分析为一体的机载运载火箭飞行程序设计仿真系统,实现了机载火箭飞行程序设计,性能分析以及三维飞行演示等功能.仿真结果表明系统提高了机载运载火箭飞行性能,并能为飞行程序设计的可行性与可靠性提供了科学依据.     

火箭飞行控制系统分布式仿真研究

以运载火箭为应用对象，研究了运载火箭飞行控制系统六自由度分布交互式仿真技术，分析了运载火箭在飞行过程中导航、制导和姿控系统的数学建模和仿真方法，建立了相应的导航、制导和姿控模型，从数学角度描述了运载火箭在飞行中的各种状态，论述了可视化交互仿真的实现过程，给出了仿真模型，设计并实现了数字仿真算法和仿真系统。     

基于数字孪生的火箭测试与发射过程健康管理技术研究

为了解决运载火箭对地面测试与发射过程中对数据综合分析能力,飞行过程的故障诊断和预测能力,以及故障处理措施的快速决策等能力的迫切需求,提出一种基于数字孪生技术的火箭测试与发射过程健康管理系统设计方案;该方案通过建立运载火箭测试与发射阶段数字孪生模型,实现对火箭测试和发射过程的天地镜像仿真,依托数字孪生模型,对运载火箭健康管理功能进行了设计和优化;利用真实火箭和数字孪生火箭的信息交互,可有效实现火箭测试过程数据分析、飞行过程协同诊断,以及故障处理决策支持等功能;该系统提高了火箭发射的可靠性,为火箭可靠飞行提供了技术保障;同时,该技术在运载火箭健康管理上的应用也面临一些关键技术还需要进一步突破和发展.     

基于DirectX的无人机三维虚拟飞行仿真系统开发

建立无人机三维虚拟飞行仿真系统对于无人机的设计、研制与操纵培训具有重要的意义.介绍了一种低成本的基于PC机的无尾式无人机实时三维虚拟飞行仿真系统,对建模与仿真、DirectX、数据库、面向对象编程等技术在可视化系统仿真领域的应用作出了积极的探索与尝试.介绍内容主要为三维仿真建模接口技术比较与采用、无人机飞行仿真系统模型组成与仿真算法采用以及如何运用软件工程概念开发无人机实时飞行仿真软件系统.     

飞行仿真系统中气候现象的仿真

为了提高视景仿真系统中虚拟气候现象的逼真度,实现全天候飞行仿真训练,提出了一种基于粒子系统理论实时仿真复杂气候现象的算法。算法以基本粒子元对气候现象进行仿真,并根据粒子运动方程,描述了粒子在受到重力、风力、气压、温度等因素影响下的运动效果。在上述问题基础上,通过驱动MS Flight Simulator可视化引擎,实现了飞行仿真中,飞行姿态、天气条件和地理环境的三维实时可视化显示。仿真试验表明,基于粒子系统的气候现象仿真对于提高MS Flight Simulator仿真系统的真实感和直观性具有一定的实用价值。     

大型运输机综合训练器虚拟仿真环境的设计

某型运输机综合训练模拟器具有飞行场景复杂、仿真仪表多、人机交互信息量大等特点.虚拟仿真环境的建立,是开发该模拟器的关键.介绍了综合训练模拟器的体系结构和虚拟仿真环境的开发方法.采用对全包线范围内的气动参数进行动态插值的方法,建立了兼顾模拟精度的准定常六自由度全量飞机运动模型;阐述了场景建模的方法和视景驱动程序的框架;给出了虚拟仪表的开发路线和人机交互的实现方法.与整个系统联调表明,该系统结构合理可靠,采用的运动模型和仿真算法满足了系统的实时性和精确度要求,图像显示效果逼真.     

火箭飞行过程数字孪生系统架构与应用研究

首先介绍了数字孪生技术的发展与现状，明确了火箭飞行数字孪生体的内涵，并提出了一种运载火箭飞行过程数字孪生系统，介绍了系统的组成架构和关键技术，展望了该系统的应用场景。基于运载火箭飞行过程数字孪生系统，可以在地面利用高速计算资源和海量数据资源，通过与真实火箭的数据交互，实现对火箭飞行全过程的跟踪映射、故障诊断、预示评估和智能决策，全面提升火箭的智能化健康管理水平，提高运载火箭的飞行可靠性。     

直升机视景仿真及座舱仪表显示系统实现

以开发一套直升机飞行视景仿真系统为目的,提出了一种基于Multigen Creator和Vega软件的三维视景仿真系统解决方案.利用三维图形开发软件Creator对座舱仪表模型进行可视化建模,使用自由度设置(DOF)技术实现仪表指针的动态交互.将模型加载到Vega的环境中,在VC++环境下,基于MFC实现了仪表的驱动程序,给出了具体的实现方法,设计了座舱仪表仿真界面.最后在Vega场景中仿真直升机的飞行状态,直观形象地反映直升机的飞行特性.实际仿真显示,该视是景系统的仿真效果形象逼真,令人满意.     

Badumna: A decentralised network engine for virtual environments

Many of today’s virtual environment applications, such as massively multiplayer online games, involve a large and rapidly changing set of users. The server-based architecture of these applications makes its hard for them to support the dynamic user base and provide a scalable solution. Badumna, a scalable network engine for large-scale virtual environments, was developed to address these issues. The approach is based on a decentralised architecture using a structured peer-to-peer network. In order to ensure a highly scalable and efficient design, Badumna uses techniques that include neighbour introductions and the formation of dynamic bounded regions to reduce the load on the peer-to-peer network. The performance of Badumna is evaluated using extensive simulations. Results indicate that Badumna is able to scale to a large number of users without placing any additional overheads on the network that degrade performance.     

最小二乘内插数学模型生成虚拟地形的可视化研究

数字高程模型 可视化 最小二乘 OpenGL （digital elevation model; visualization; least squares ; OpenGL）
【文 摘】本文通过对最小二乘内插数学模型的分析和研究,利用搜索圆的搜索方法,运用C44语言和OpenGL动态连接库将采集的离散点生成DEM数据,实现了由二维平面上的等高线到三维虚拟地形的可视化,并对可视化效果进行了比较和分析。可视化结果表明,此算法速度快且效果好。此研究成果对虚拟战场环境的生成有一定参考价值。     

城市低空环境中多旋翼无人机在线航线规划方法

为无人机规划一条从起点出发到达指定目标点的航线是实现无人机各种应用的重要前提.飞行过程中,无人机应具备对于各种动态变化快速响应并重新规划航线的能力.针对多旋翼无人机在飞行过程中可能遇到的各种动态变化,研究其在离散城市环境下的在线航线规划问题.首先,建立离散环境模型,并基于此模型定义无人机飞行规则;随后,建立无人机航线规划模型,包括对航点的约束条件及航线规划的指标;其次,将各种动态变化按照其对无人机的不同影响进行分类,分为固定禁飞区、合作无人机、非合作无人机3类,并针对不同种类动态变化特点,分别提出重新规划三维航线、改变飞行速度、滚动优化三维航线3种在线航线规划策略及综合应对策略;然后,改进快速随机扩展生成树算法(RRT),使其适合于离散城市环境.仿真实验中分别验证了所提出的在线航线规划策略在应对单一动态变化及组合动态变化时的有效性.     

Deep learning-based smart task assistance in wearable augmented reality

Wearable augmented reality (AR) smart glasses have been utilized in various applications such as training, maintenance, and collaboration. However, most previous research on wearable AR technology did not effectively supported situation-aware task assistance because of AR marker-based static visualization and registration. In this study, a smart and user-centric task assistance method is proposed, which combines deep learning-based object detection and instance segmentation with wearable AR technology to provide more effective visual guidance with less cognitive load. In particular, instance segmentation using the Mask R-CNN and markerless AR are combined to overlay the 3D spatial mapping of an actual object onto its surrounding real environment. In addition, 3D spatial information with instance segmentation is used to provide 3D task guidance and navigation, which helps the user to more easily identify and understand physical objects while moving around in the physical environment. Furthermore, 2.5D or 3D replicas support the 3D annotation and collaboration between different workers without predefined 3D models. Therefore, the user can perform more realistic manufacturing tasks in dynamic environments. To verify the usability and usefulness of the proposed method, we performed quantitative and qualitative analyses by conducting two user studies: 1) matching a virtual object to a real object in a real environment, and 2) performing a realistic task, that is, the maintenance and inspection of a 3D printer. We also implemented several viable applications supporting task assistance using the proposed deep learning-based task assistance in wearable AR.     

一种面向分布式虚拟环境的分层迭代负载平衡算法

为了支持大规模用户共享虚拟环境,多服务器结构被应用到分布式虚拟环境系统中,每个服务器负责虚拟环境的一个区域划分.由于用户不可预知的移动和交互,可能会导致某些服务器负载过重.现有的负载平衡算法注重于将负载在服务器间重分配,但引入开销过大,影响系统交互性能.提出一种分层迭代的动态负载平衡算法,以过载区域为中心,分层地选择周围有限数量的区域作为调整目标,将过载部分由内向外迭代地扩散到各层,多次迭代达到负载平衡状态.针对倾斜和聚簇两种典型用户分布的虚拟环境,对算法进行验证并与现有的3种负载平衡算法进行比较.结果表明,该算法可以快速、有效地调整负载并引入较少的开销.     

Three views of virtual reality: virtual environments in the USmilitary

A virtual environment is a generic, relatively low-cost real-time interactive simulation. It is shown that the US military has been a primary supporter of real-time simulation for more than 60 years, ever since the development of the Link Flight Instrument Trainer in the late 1930s. The development of flight simulation systems and head-mounted displays are reviewed. The use of virtual environments for team training, battlefield review and tactics development is discussed. Several research projects involving virtual environments and military applications are described     

Exploration of architectural spaces by blind people using auditory virtual reality for the construction of spatial knowledge

Navigation within a closed environment requires analysis of a variety of acoustic cues, a task that is well developed in many visually impaired individuals, and for which sighted individuals rely almost entirely on visual information. For blind people, the act of creating cognitive maps for spaces, such as home or office buildings, can be a long process, for which the individual may repeat various paths numerous times. While this action is typically performed by the individual on-site, it is of some interest to investigate at which point this task can be performed off-site, at the individual's discretion. In short, is it possible for an individual to learn an architectural environment without being physically present? If so, such a system could prove beneficial for navigation preparation in new and unknown environments. The main goal of the present research can therefore be summarized as investigating the possibilities of assisting blind individuals in learning a spatial environment configuration through the listening of audio events and their interactions with these events within a virtual reality experience. A comparison of two types of learning through auditory exploration has been performed: in situ real displacement and active navigation in a virtual architecture. The virtual navigation rendered only acoustic information. Results for two groups of five participants showed that interactive exploration of virtual acoustic room simulations can provide sufficient information for the construction of coherent spatial mental maps, although some variations were found between the two environments tested in the experiments. Furthermore, the mental representation of the virtually navigated environments preserved topological and metric properties, as was found through actual navigation.     

空空导弹飞控软件研制中的虚拟样机应用

飞控软件已成为先进数字化空空导弹研制的关键，如何对嵌入式飞控软件进行验证是空空导弹研制的焦点。随着虚拟原型技术在空空导弹飞控系统的应用，该文定义并论述了空空导弹飞控系统虚拟样机的组成以及功能，指出它是先进数字化空空导弹飞控软件重要的核心支持平台技术。结合一个基于空空导弹飞控系统虚拟样机的动态仿真系统的开发，论述了其关键技术以及解决途径，进行了基于飞控系统虚拟样机的飞控软件仿真，给出了仿真结果。实践表明，全数字的基于飞控系统虚拟样机的飞控软件仿真已经成为研制数字化导弹的必须经历的阶段，其应用将大大缩短设计周期，保证飞控软件设计的质量与可靠性。     

Flocking techniques to naturally support navigation in large and open virtual worlds

This paper proposes and explores the use of flocking techniques to naturally support navigation in large and open virtual environments. The proposed approach comprises both a flocking algorithm (which simulates the behavior of a flock of virtual beings) and a control algorithm (which manages the navigation information and parameterizes the flocking behavior). The model was developed and evaluated through a user study which investigated whether the addition of the proposed model has an effect on the user experience when exploring a virtual environment. In the research the experiment group explored a virtual environment where the proposed flocking model was added to suggest places to visit. The participants were not informed about the guiding abilities of the virtual animals. The control group explored the same virtual environment without the animal flock. The impact of both cases was compared. The results indicate that the proposed model is adequate to suggest places to visit in large and open virtual worlds.