Conceptual design and RCS performance research of shipborne early warning aircraft

In order to improve the survivability of the aircraft,conceptual design and radar cross section（RCS） performance research are done. The CATIA software is used to design the 3D digital model of the shipborne early warning aircraft, and some measures are taken to reduce the RCS characteristics of the early warning aircraft at the same time. Based on the physical optics method and the equivalent electromagnetic flow method,the aircraft＇s RCS characteristics and strength distribution characteristics are simulated numerically, and compared with the foreign advanced shipborne early warning aircraft. The simulation results show that under the X radar band, when the incident wave pitching angle is 0？, compared with the foreign advanced shipborne early warning aircraft, the forward RCS average value of the conceptual shipborne early warning aircraft is reduced to 24.49%, the lateral RCS average value is reduced to 5.04%, and the backward RCS average value is reduced to 39.26%. The research results of this paper are expected to provide theoretical basis and technical support for the conceptual design and the stealth design of the shipborne early warning aircraft.     

Improved algorithm of atmospheric refraction error in Longley-Rice channel model

Longley-Rice channel model modifies the atmospheric refraction by the equivalent earth radius method, which is simple calculation but is not accurate. As it only uses the horizontal difference, but does not make use of the vertical section information, it does not agree with the actual propagation path. The atmospheric refraction error correction method of the Longley-Rice channel model has been improved. The improved method makes use of the vertical section information sufficiently and maps the distance between the receiver and transmitter to the radio wave propagation distance, It can exactly reflect the infection of propagation distance for the radio wave propagation loss. It is predicted to be more close to the experimental results by simulation in comparison with the measured data. The effectiveness of improved methods is proved by simulation.     

Microwave characteristic simulation research for a kind of novel electromagnetic structure

A kind of novel electromagnetic structure of Cassini cross section is proposed and simulation is implemented with business microwave soft CST based on finite integral technique （FIT）. The electromagnetic field mode type of Cassini wave-guide belongs to TE, and the electromagnetic field intensity is stronger near the neck region than at other areas. For Cassini electromagnetic patches and lumped elements, the radar cross section （RCS） is smaller around 7 GHz with -30.85 dBsm, and the absorbing property is better around 13 GHz with 4.56 dBsm difference of RCS from comparing of pure medium. For novel radiation structure of Cassini cross-section patches, the electromagnetic field value is larger in the neck areas of two half patches. At last, the potential application and development of Cassini oval structure are put forward in the electromagnetic stealth technology and antennae design.     

Efficient Calculation of the Radar Cross Section at the Interior Resonance by the Inverse Power Method

It is well known that the incorrect results will be given using either the electric or magnetic field integral equation to calculate the radar cross section (RCS) of a closed body at the interior resonance. In this paper, an effective iterative technique is used to correct the calculated surface current density from the electric field integral equation. The radar cross section is computed for an infinite conducting circular cylinder at the interior resonance, and the obtained results are     

A New Stealth Technique for Vehicles Based on the Enhancement of Angular Glint

A general 2-D problem of electromagnetic scattering from a multiple cavity-backed longitudinally loaded slotted perfectly conducting cylinder with arbitrary cross section is formulated. The formulation is used to account for the scattered field from the scale models, for which, a series of experiments has been conducted in an anechoic chamber. Quite good agreement between theory and experiment is obtained. The analysis of the experimental results near resonant frequency shows that the reduction of backscattering radar cross section over wide aspect angles, and the dominant enhancement of target angular glint (linear deviation) can be achieved by impedance loading such as multiple cavity-backed slots, which realizes a new stealth technique for vehicles.     

3D multipath planning for UAV based on network graph

According to the characteristic and the requirement of multipath planning,a new multipath planning method is proposed based on network.This method includes two steps:the construction of network and multipath searching.The construction of network proceeds in three phases:the skeleton extraction of the configuration space,the judgment of the cross points in the skeleton and how to link the cross points to form a network.Multipath searching makes use of the network and iterative penalty method (IPM) to plan multi-paths,and adjusts the planar paths to satisfy the requirement of maneuverability of unmanned aerial vehicle (UAV).In addition,a new height planning method is proposed to deal with the height planning of 3D route.The proposed algorithm can find multiple paths automatically according to distribution of terrain and threat areas with high efficiency.The height planning can make 3D route following the terrain.The simulation experiment illustrates the feasibility of the proposed method.     

分布式视景仿真技术综述

分布式视景仿真技术是可视化仿真与网络化仿真交叉融合而发展起来的仿真技术。对分布式视景仿真的学科范畴进行了探讨,追溯了分布式视景仿真的技术起源,对其发展脉络进行了划分。对该技术多年来的应用和研究现状进行了分析和评述,最后就其今后的研究发展方向作了预想。研究成果有助于该项技术理论和应用体系的丰富和完善。

Abstract：

Distributed visual simulation （DVS） technology is an intersecting and syncretic simulation technology including visual simulation and network simulation. The subject category of DVS was discussed, and the technology origin and development process were backward. The application and research status were analyzed. At last, the future research direction was expected. These research harvests can help building the theory and application system of DVS.     

Hybrid optimization of dynamic deployment for networked fire control system

With applying the information technology to the military field, the advantages and importance of the networked combat are more and more obvious. In order to make full use of limited battlefield resources and maximally destroy enemy targets from arbitrary angle in a limited time, the research on firepower nodes dynamic deployment becomes a key problem of command and control. Considering a variety of tactical indexes and actual constraints in air defense, a mathematical model is formulated to minimize the enemy target penetration probability. Based on characteristics of the mathematical model and demands of the deployment problems, an assistance-based algorithm is put forward which combines the artificial potential field （APF） method with a memetic algorithm. The APF method is employed to solve the constraint handling problem and generate feasible solutions. The constrained optimization problem transforms into an optimization problem of APF parameters adjustment, and the dimension of the problem is reduced greatly. The dynamic deployment is accomplished by generation and refinement of feasible solutions. The simulation results show that the proposed algorithm is effective and feasible in dynamic situation.     

Mie series for electromagnetic scattering of chiral metamaterials sphere

The electromagnetic scattering of chiral metamaterials is simulated with the Mie series method.Based on the spherical harmonics vector function in chiral metamaterials,the electromagnetic fields inside and outside of chiral metamaterials sphere are expanded.By applying the continuous boundary condition between the chiral metamaterials and surrounding medium,and the transformation from linearly to circularly polarized electric field components,the co-polarized and cross-polarized bistatic radar cross scattering(RCS) of chiral metamaterials sphere are given.How to overcome the instability of chiral metamaterials sphere of Mie series formula is discussed.The electromagnetic scattering of chiral metamaterials,normal media and metamaterials are compared.The numerical results show that the existence of chirality ξ of chiral metamaterials can decrease the bistatic RCS compared with the same size as normal media sphere.     

Discrete Simulation of Flexible Plate Structure Using State-Space Formulation

This paper presents the development of dynamic simulation of a flexible plate structure with various boundary conditions. A flexible square plate is considered. A finite-difference method is used to discretise the governing partial differential equation formulation describing its dynamic behaviour. The model thus developed has been validated against characteristic parameters of the plate. The model thus developed is further formulated using discrete state-space representation, to allow easy and fast implementation for simulating the dynamic behaviour of the plate with various boundary conditions. The simulation algorithm thus developed is validated, and accurate results with representation of the first five modes of vibration of the plate have been achieved. The algorithm thus developed is used in subsequent research work as a platform for development and verification of suitable control strategies for vibration suppression of flexible plate structures.     

交流接触器E型电磁铁分磁环的仿真设计

采用非线性瞬态磁路方法建立E型电磁铁分磁环的磁路数学模型，结合电磁场分析和可视化技术对交流接触器的工作特性进行了仿真计算，通过实验验证计算的正确性。结果表明，利用该仿真软件可以方便地对交流电磁系统的分磁环进行设计，大幅度提高交流电器产品的设计效率。     

海面背景下弱目标RCS估计及特性分析

雷达截面积(radar cross section, RCS)可以为武器装备设计提供支撑。因此，许多国家都建立了标准测试场，可以满足大多数目标RCS测量的需要。对于海面背景下的非合作弱目标而言，只能依赖实际测试来获取目标RCS,但有时会面临多径干扰和信号弱的问题。针对该问题，在海上外定标和目标信杂比改善基础上，提出了一种目标RCS估计方法。设计并开展了海上目标RCS测量试验，并对测试数据进行了分析，验证了新方法的有效性，同时给出了弱目标RCS起伏特性的定性描述。     

基于空间电压矢量PWM控制的磁轴承开关功放

针对传统开关功放驱动多自由度磁轴承体积大、功耗大的缺点,设计了一种新型磁轴承功放.该功放采用了三桥臂主电路拓扑结构以及空间矢量PWM控制策略,利用六个功率开关管的八种开关状态相对应的基本电压空间矢量来逼近磁轴承线圈的电压,根据线圈空间电压矢量切换来对其电流进行控制.这种功放能够提供双极性的电流驱动,同时驱动磁轴承两个自由度的绕组,该功放驱动的磁轴承线圈电压具有三态,具有三电平功放低纹波电流的优点.仿真和实验结果表明,该功放可以独立的对两路输出电流进行控制,并且能够控制其很好地跟踪给定信号.与传统类型的磁轴承开关功放相比,减小了体积和开关损耗,提高了可靠性,特别适合于空间环境应用.     

有源RCS及其应用

随着电子设备和雷达系统的迅速发展, 电磁环境变得愈加复杂。在复杂电磁环境中, 针对多辐射源和有源设备照射下雷达目标电磁散射特性评估的需求, 提出并综述了有源雷达散射截面(active radar cross section, ARCS)的定义、仿真方法和应用示例。ARCS可以计算多辐射源相干和非相干照射条件下, 雷达端观察到的视在雷达散射截面(radar cross section, RCS)值。本文给出了ARCS的仿真分析步骤, 利用仿真软件得出计算ARCS所需远场量。在单入射源情况下, ARCS等同于传统RCS, 验证了ARCS计算方法的准确性。此外, 以分布式相参雷达和有源对消目标隐身为例, 介绍了ARCS的应用, 利用ARCS的概念评估了有源对消的效果。最后, 探讨了目前研究存在的技术问题以及未来可能发展的研究方向。     

交叉谱估计及其在导弹系统仿真模型验证中的应用

本文阐明了交叉谱的基本概念。结合反坦克导弹系统的特点，提出一种利用交叉谱来检验导弹系统仿真模型有效性的方法，这一方法的显著特点是：它能够同时给出几组动态数据在频谱、相位、线性相关性以及增益等方面的信息，并可以给出定量的估计结果。最后利用实例来说明这一方法在导弹仿真模型验证中的应用     

舰船目标雷达回波特征信号的建模与仿真

目标建模与特征信号仿真是雷达对目标进行探测与识别的重要前提和基础。针对宽带条件下大型舰船目标的雷达特征信号难以进行实测和缩比测量的难点，采用面元法对目标的雷达散射截面（RCS）进行了有效的预估，通过多频点RCS成像方法获得目标的一维距离像特征信号。给出了具体建模和仿真计算的实例，并进行了详尽的结果分析。     

基于磁耦合谐振的无线能量传输系统

针对目前电磁感应无线能量传输方式有效传输距离近、传输效率低等问题,为实现小口径武器系统的无线能量与信息的同步、快速、高效传输,基于电磁耦合谐振理论,提出了一种三线圈磁耦合谐振自适应能量传输系统。利用磁耦合谐振互感模型,对能量传输系统三线圈拓扑电路进行了分析,并讨论了整个系统的传输功率、传输效率与线圈谐振频率、耦合系数之间的相互关系。基于锁相环优化控制理论,提出了传输系统自适应谐振最大功率控制策略,对储能电容接收功率和充电时间进行了优化。静态实验结果表明,利用上述理论设计的三线圈磁耦合谐振能量传输系统,性能可满足耦合距离20 mm、相对运动速度2.5 m/s及铁磁环境下能量的传输,这种新颖的传输系统可为新一代武器系统的信息交联设计提供一定的理论和技术支持。     

基于dSPACE半实物仿真技术的伺服控制研究与应用

半实物仿真是一种针对实际过程的实时仿真技术,它可将需要的实际受控对象放置在仿真系统回路中进行仿真研究,可对控制参数进行在线调参,改善实际系统的性能。本文介绍了基于dSPACE的半实物仿真技术,利用MATLAB/Simulink的系统建模方法和dSPACE系统的软硬件环境,完成了对足球机器人伺服控制系统的研究与开发,获得了满意的效果。     

基于高斯过程模型的多响应稳健参数设计

针对高维试验数据的稳健参数设计问题, 在高斯过程(Gaussian process, GP)的建模框架下, 采用部分平行的GP(parallel partial GP, PPGP)模型来构建试验因子与多质量特性之间的响应曲面, 在此基础上运用多元质量损失函数作为优化指标来获得可控因子的最佳参数设计值。并且以一个经典仿真算例和两个实际案例验证了所提方法的有效性和优劣性。研究结果表明，与独立建模的单变量GP模型或Kriging模型比较而言, 所提方法不仅能够有效地处理高维试验数据的建模与参数优化问题, 而且能够获得更为稳健的优化结果, 运行效率更高。