吊放声纳应召搜潜效能的建模与仿真

基于反潜直升机吊放声纳的探测原理及战术使用特点,在目标初始位置概略已知,速度和航向未知的条件下,分析了目标散布规律,建立了搜潜效能分析计算模型,给出了吊放声纳在扩展方形搜索方式下的应召搜潜概率；并采用蒙特卡洛法的基本思想对该计算模型进行了仿真验证,证明了该方法的有效性；最后,基于扩展方形搜索方式,研究了在单机和双机搜潜条件下搜索概率的不同结果,分析了潜艇速度、应召延迟时间、吊放次数等参数 对搜索概率的影响。     

有人无人直升机协同搜潜效能研究

通过分析直升机搜潜的任务过程,结合蒙特卡洛法的随机抽样特性,建立了基于蒙特卡洛法的效能 评估模型,用以评估直升机使用浮标搜潜的成功概率。基于仿真实验对有人直升机搜潜、无人直升机双机编组 搜潜、有无人直升机协同搜潜的效能进行了对比分析。     

反潜直升机搜潜效能分析

作为战术反潜的主要手段,反潜直升机已成各国海军的重点研制装备。考虑反潜直升机所搭载的众多探潜设备,包括雷达、红外前视仪、声纳浮标和磁探仪等,在详细分析上述搜索设备性能的基础上,针对应召和巡逻两种典型搜潜方式进行了典型组合搜潜方案的效能分析。仿真分析验证了组合搜潜方案的合理性与可行性。     

航母中程对潜防御区声呐舰配置方法

针对航母中程对潜防御区声呐舰配置问题,在分析航渡过程中航母受敌导弹攻击威胁的基础上,从有效应 对敌潜艇导弹攻击,保障航母安全的要求出发,对中程对潜防御区声呐舰的配置问题进行了研究,提出了中程对潜 防御区声呐舰的配置原则和方法,对航母编队反潜作战的兵力配置具有重要的参考指导作用。     

潜空导弹作战效能研究

在过去的几十年中,空潜对抗优势一直是向飞机一方倾斜的。有些国家已经在研制用于潜艇上的防空导弹,以提高潜艇在空潜对抗时的生存能力。文中介绍了潜空导弹的发展状况,对其作战效能进行了初步研究,建立了潜空导弹作战效能评估模型并进行了算例分析。     

反潜巡逻机布放包围浮标阵应召搜潜建模与仿真

依据经典的浮标应召搜潜方法,结合实际搜潜过程,以某型反潜巡逻机为背景,建立了反潜巡逻机布放圆形阵、方形阵和三角形阵搜潜航路规划的数学模型。对3种阵形的搜潜效能进行分析,仿真了初始距离、潜艇初始位置散布、潜艇经济航速和海洋环境噪声级对浮标阵搜潜效能的影响。仿真结果分析表明:相同条件下,方形阵的搜潜效能要略高于圆形阵和三角形阵的搜潜效能;3种包围阵的搜潜效能均随初始距离、初始位置散布、潜艇经济航速和海洋环境噪声级的增大而降低。     

磁探仪应召搜潜建模与仿真

依据经典的磁探仪应召搜潜方法,以某型反潜巡逻机为背景,建立了反潜巡逻机利用磁探仪执行平行航线、扩展矩形和螺旋形搜潜模型.对3种方法的搜潜概率进行分析,仿真了相同潜艇运动模型条件下,潜艇初始位置散布、初始距离、潜艇经济航速和海洋环境磁噪声对搜潜概率的影响.实验结果表明:相同条件下,螺旋形搜潜效能最高;潜艇只进行航速机动时...     

A Vector Autopilot System

Current technology has evolved low cost, highly reliable solid state vector magnetometers with excellent angular resolution. This paper discusses the role of a three-axis magnetometer as a new instrument for aircraft attitude determination. Using flight data acquired by an instrumented aircraft, attitude is calculated using the Earth's magnetic field vector and compared to measured attitudes. The magnetic field alone is not adequate to resolve all attitude variations and the need for a second reference angle or vector is discussed. A system combining the functions of heading determination and attitude measurement is presented to show that both functions can be implemented with essentially the same component count required to measure heading alone. lt is concluded that with the correlation achieved in calculated and measured attitude there is a potential application of vector magnetometry in attitude measurement systems.     

基于先验目标航向的主/被动联合多基地航空搜潜建模与仿真

利用主动吊放声纳与被动浮标组成多基地航空声纳对目标进行搜索,可节约搜索时间,有效提高搜潜效率。针对已知目标的大概航向,在有限范围内确定目标存在区的情况下,建立了多基地搜潜范围模型、单机吊放声纳和浮标的主/被动联合多基地搜潜模型、潜艇运动模型,仿真分析了潜艇初始航向、海洋环境噪声、搜索样式等因素对联合搜索概率的影响。结果表明,潜艇初始航向角度对单机吊放声纳和浮标的联合搜索概率影响较小,海洋环境噪声的变化对单机吊放声纳和浮标的联合搜索概率影响较大。     

前方反潜防护搜索方法及其效能评估

结合航渡中航母编队反潜防护的特点要求以及反潜巡逻机使用声呐浮标搜索的基本方法,研究提出了反潜巡逻机使用声呐浮标为航渡中的航母编队进行前方反潜防护搜索的作战使用方法,并使用蒙特卡洛法在想定条件下对搜索效能进行了仿真评估,进而通过仿真结果的分析,提出了对作战使用具有指导意义的意见建议。     

机载拖曳体动力学建模及分析

在某些航空应用场景,需要通过飞行器拖曳功能性部件完成特定性任务,例如机载拖曳对潜通信天线等,在这些应用中,通过建立科学的模型和方法,准确地分析稳态、动态特性是保证拖曳体正常工作的前提条件。本文以对潜通信天线为例,建立考虑天线气动力、惯性力以及弹性力的多体动力学的机载天线动力学模型,并对该模型的稳态结果进行算例验证;对考虑载机非定常运动以及突风作用等扰动后的天线系统动态响应进行分析,并对天线断裂等极端情况进行评估。结果表明：本文所建立的模型在垂直度、天线张力等方面的分析结果较好,能够应用于航空拖曳体的稳态及动态特性分析,在对潜通信天线、加油管等系统的设计方面有一定的工程价值。     

THEMIS Ground-Based Magnetometers

The THEMIS mission includes a comprehensive ground-based measurement network that adds two additional dimensions to the information gained in the night magnetosphere by the five THEMIS spacecraft. This network provides necessary correlative data on the strength and extent of events, enables their onsets to be accurately timed, and provides an educational component in which students have an active participation in the program. This paper describes the magnetometers installed to obtain these ground-based North American magnetic measurements, including the magnetometers installed as part of the educational effort, and the support electronics provided by UCLA for the ground-based observatories. These magnetometers measure the Earth’s magnetic field with high resolution, and with precise timing provided by the Global Positioning System. They represent UCLA’s next generation of low-cost, ground-based magnetometers using an inexpensive personal computer for data collection, storage and distribution. These systems can be used in a stand-alone mode requiring only AC power. If there is Internet connectivity, they can be configured to provide near real-time data over the web. These data are provided at full resolution to the entire scientific community over the web with minimal delay.     

The Magnetospheric Multiscale Magnetometers

The success of the Magnetospheric Multiscale mission depends on the accurate measurement of the magnetic field on all four spacecraft. To ensure this success, two independently designed and built fluxgate magnetometers were developed, avoiding single-point failures. The magnetometers were dubbed the digital fluxgate (DFG), which uses an ASIC implementation and was supplied by the Space Research Institute of the Austrian Academy of Sciences and the analogue magnetometer (AFG) with a more traditional circuit board design supplied by the University of California, Los Angeles. A stringent magnetic cleanliness program was executed under the supervision of the Johns Hopkins University’s Applied Physics Laboratory. To achieve mission objectives, the calibration determined on the ground will be refined in space to ensure all eight magnetometers are precisely inter-calibrated. Near real-time data plays a key role in the transmission of high-resolution observations stored on board so rapid processing of the low-resolution data is required. This article describes these instruments, the magnetic cleanliness program, and the instrument pre-launch calibrations, the planned in-flight calibration program, and the information flow that provides the data on the rapid time scale needed for mission success.     

水下航行潜艇尾流特征仿真建模方法

潜艇的物理特征是航空反潜传感器搜索潜艇的主要依据, 对潜艇特征进行准确的仿真建模能够实现 对潜艇的有效分析。本文以水下航行状态下的潜艇为背景,基于潜艇外部环境和内部工况因素,提出了一种尾 流特征仿真建模方法。通过仿真建立了潜艇内波尾流特征仿真模型和热尾流模型,仿真结果表明,所得模型从 雷达目视和红外探测两个维度模拟了水下潜艇的尾流特征,能够有效反映水下航行潜艇尾流特征。     

三维捷联磁传感器误差分析及补偿

磁传感器在导航系统中的应用日益广泛。在车载导航系统工作环境中,外界干扰磁场复杂,严重影响了磁航向测量的精度。因此对磁航向进行适当的罗差补偿是提高磁航向测量精度的有效途径。文中介绍了用磁传感器进行磁航向测量的原理,分析了由于磁场矢量叠加产生的罗差,提出了基于傅立叶级数的罗差模型和补偿方法。工程实践表明,上述方法的使用收到了较好的效果。     

Extension of a Two-Step Calibration Methodology to Include Nonorthogonal Sensor Axes

We present an extension of the nonlinear two-step estimation algorithm originally developed for the calibration of solid-state strapdown magnetometers. We expand the algorithm to include nonorthogonality within a sensor set for both two- and three-axis sensors. Nonorthogonality can result from manufacturing issues, installation geometry, and in the case of magnetometers, from soft iron bias errors. Simulation studies for both two- and three-axis sensors show convergence of the improved algorithm to the true values, even in the presence of realistic measurement noise. Finally the algorithm is experimentally validated on a low-cost solid-state three-axis magnetometer set, which shows definite improvement postcalibration. We note that the algorithm is general and can be applied to any two- or three-axis sensor set (such as accelerometers) with an error model consisting of scale, offset, and nonorthogonality errors.     

风雨对飞机飞行安全性的影响

风雨严重影响飞机的飞行安全。基于动量定理建立了一种根据降雨条件、风场特性、飞机特征和飞行状态计算雨滴对飞机产生的撞击力和力矩的方法,研究了风雨对飞机气动特性的影响,进而建立了飞机在风雨中飞行的运动方程。通过引入驾驶员的操纵模型,对飞机在风雨中飞行的运动特性进行了数值仿真研究。仿真结果表明:降雨会使飞机的升力减小,阻力增大,平衡迎角增加,不利于飞机的飞行安全;当降雨过程中伴随有风时,风会改变飞机的飞行迎角,使得飞机更容易出现因失速而造成的飞行事故;降雨时飞机的抗风能力降低。     

一种民用飞机后储藏室的构建及适航验证思路

民用飞机的储存设备是飞机运营时需要使用的一类设备,可用于储存乘客、机组人员携带的物品及飞机型号设计中需要使用的设备。阐述了储存设备（隔间）的适航要求,并以某型号民用飞机上的后储藏室为例, 详细地阐述了其构建思路及对相应适航条款的验证思路。     

OpenGL在FBG传感网络结构健康监测中的应用

对飞机机翼三维重建方法及其应用进行了研究,并采用开放性图形库OpenGL(Open Graphics Librar-y)三维图形软件接口标准,在Visual C 6.0平台下开发了基于光纤布拉格光栅FBG(Fiber Bragg Grating)动态应变采集与机翼模型三维重建系统.本文通过共享数据库的方式,在机翼模型与FBG传感网络数据直接建立连接,FBG传感器数据变化可实时在三维机翼模型中进行体现,由此实现了直观地对飞机机翼各监测点应变情况的实时监测.     

Design,modeling, and control of morphing aircraft:A review

A morphing aircraft can adapt its configuration to suit different types of tasks, which is also an important requirement of Unmanned Aerial Vehicles(UAV). The successful development of an unmanned morphing aircraft involves three steps that determine its ability and intelligent: configuration design, dynamic modeling and flight control. This study conducts a comprehensive survey of morphing aircraft. First, the methods to design the configuration of a morphing aircraft are presented and analyzed...