Time filter

Source Type

Yang X.,HIGH-TECH | Yang X.,Tsinghua University | Zou H.,Tsinghua University | Lu F.,The Equipment Research Institute of second artillery | And 4 more authors.
Simulation Modelling Practice and Theory | Year: 2010

With the merits such as hiding receiving, easy-deploying and high security, passive location has attracted more and more attention and plays an important role in fields as diverse as navigation, location, and tracking, etc. However, the current filters models for passive location methods are most under the framework of the probability theory, thus they can not estimate the state in some passive location with fuzzy uncertainty accurately. Although the fuzzy extended Kalman filter (FEKF) can deal with the fuzzy uncertainty, it unavoidably introduces truncation error. In this paper, based on the FEKF and the iterated extended Kalman filter (IEKF) principle, a new fuzzy passive location model is built, and moreover, an iterated fuzzy extended Kalman filter (IFEKF) is proposed for estimating the target state. Compared to the FEKF and the IEKF, the proposed algorithm can not only reduce the truncation error, but also deal with fuzzy uncertainty. Moreover, it is proved that the IFEKF update is an application of the Gauss-Newton method. Then, a fuzzy passive location algorithm is proposed. Simulation results demonstrate that the proposed approach has better estimation precision than the traditional fuzzy extended Kalman filter. © 2009 Elsevier B.V. All rights reserved.

Wang D.,High Institute of Applied Sciences and Technology | Xu S.,High Institute of Applied Sciences and Technology | Cao Y.-W.,The Equipment Research Institute of Second Artillery | Qin F.,High Institute of Applied Sciences and Technology
Wuli Xuebao/Acta Physica Sinica | Year: 2014

Electromagnetic properties of a two-dimensional metallic photonic crystal in a transmission line is analyzed, and a compact TEM-TE11 high-power microwave mode converter which takes this type of sturcture for phase-shiftting is presented. An L band TEM-TE11 mode converter is optimized using the commercial software cst microwave studio. Its conversion efficiency is 98% at the center frequency of 1.58 GHz. Over the frequency range of 1.56-1.625 GHz, the conversion efficiency exceeds 90%, with a corresponding bandwidth of 4.1%. This mode converter has a gagawatt level power handling capability, thus it is suitable for narrow band high-power microwave application. Using magnetically insulated transmission line oscillator as a high-power microwave source, particle-in-cell simulation is carried out to test the performance of the mode converter. It is found that the proposed mode converter works well with this narrow band high power microwave device. © 2014 Chinese Physical Society.

Ming D.-L.,Huazhong University of Science and Technology | Xu Q.-C.,Huazhong University of Science and Technology | Li X.-C.,The Equipment Research Institute of Second Artillery
Xitong Fangzhen Xuebao / Journal of System Simulation | Year: 2012

Simulating and rendering realistic ocean is always one of the most popular and difficult tasks in computer graphics and oceanography. However, because of the restriction of computer software and hardware conditions, mass data and real-time, there are less people to research global ocean simulation. Under the background of global environment simulation, a solution for the application of global ocean simulation on the basis of previous work was described, and the visualization system was successfully realized using OSG (OpenSceneGraph) API and all kinds of open-source libraries, and the result of cross-sea flight was demonstrated. At last, the deficiencies of the solution were analyzed and some improvement suggestions were made.

Loading The Equipment Research Institute of second artillery collaborators
Loading The Equipment Research Institute of second artillery collaborators