检索结果-内蒙古大学图书馆

International Conference on Circuits, System and Simulation

作者： Weiting Gao Guobing Cheng Fei Ma Weilun Liu Institute of Information and Navigation Airforce Engineering University Xi'an China Xi'an Modern Control Technology Research Institute Xi'an China

ISBN: (纸本)9781538678206

Aiming at the problem that the eigenvalue based spectrum sensing algorithms don't perform well in the situation of low SNR and small sample, based on the difference value between the maximum and minimum eigenvalue spectrum sensing algorithm (DMM), a Difference between the mean and minimum eigenvalue spectrum sensing algorithm (DAM) was proposed via the limiting distribution of minimum eigenvalue and the energy quality of the mean eigenvalue with the Random Matrix Theory (RMT). Analyze the algorithm performance (DAM1 and DAM2) with two different thresholds relatively, which were deducted in different ways. The simulation results show the DAM has the best performance without increasing algorithm complexity over the DMM and current Difference between the Maximum and average Energy spectrum sensing algorithm (ME-S-ED) in the situation of low SNR and sample, the DAM1 suits low SNR better and the DAM2 suits sample better.

关键词： cognitive radio spectrum sensing RMT DMM

来源：评论

学校读者我要写书评

暂无评论

A Generation of Glidepath and Guidance Parameters of Shipboard Aircraft Based on SRGPS

A Generation of Glidepath and Guidance Parameters of Shipboa...

引用

IEEE Chinese Guidance, navigation and control Conference (CGNCC)

作者： Li Ma Guangwen Li Lina Xu Qiuling Jia Lin Qi Xianglun Zhang School of Automation Northwestern Polytechnical University Xi’an China Navigation Department AVIC Flight Automatic Control Research Institute Xi’an China Aeronautical Radio electronics Research Institute Aviation Industry Corporation of China Shanghai China Science and Technology on Aircraft Control Laboratory Flight Automatic Control Research Institute Xi’an China

ISBN: (数字)9781538611715

ISBN: (纸本)9781538611722

Shipboard Relative Global Positioning System (SRGPS) is the sea-based variant of Joint Precision Approach and Landing System (JPALS), which will replace the current military navigation and landing system for all ship aircrafts. This paper describes a generation of the glidepath and guidance parameters for the automatic carrier landing system (ACLS) of shipboard aircrafts based on SRGPS. To define the glidepath, three coordinate systems which are cant deck system, ship body system and static deck system are established, the motion of ship such as pitch, roll, yaw, heave and so on can be depicted in the coordinate systems. Based on accurate coordinates in ship body system and the direction cosine matrixes (DCM) between these coordinate systems, the position vectors of the key points of glidepath are gotten, then the glidepath of ACLS is defined and depicted as a vector. After the translation of the position of the aircraft and hook from the GPS coordinate frame to the system in which the glidepath is defined, the calculating procedure of guidance parameters is described. A simulation based on a type of aircraft demonstrates the validation of the generation of glidepath and parameters.

关键词： Marine vehicles Aircraft Global Positioning System Aerospace control Aircraft navigation Transforms Antenna measurements

来源：评论

学校读者我要写书评

暂无评论

Generalised Error Functions from the Kerr Metric

引用

Chinese Physics Letters 2016年第3期33卷 12-16页

作者：唐文林罗子人刘润球 Science and Technology on Aerospace Flight Dynamics Laboratory Beijing Aerospace Control Center Department of Aerospace Guidance Navigation and Control School of AstronauticsBeihang University QUEST Center of Quantum Engineering and Space-Time Research Leibniz Universitt Hannover Max Planck Institute for Gravitational Physics(Albert Einstein Institute) Institute of Applied Mathematics Morningside Center of Mathematics and LESCInstitute of Computational MathematicsAcademy of Mathematics and System ScienceChinese Academy of Sciences

Motivated by the effort to understand the mathematical structure underlying the Teukolsky equations in a Kerr metric background, a homogeneous integral equation related to the prolate spheroidal function is studied. From the consideration of the Fredholm determinant of the integral equation, a family of generalized error function is defined, with which the Fredholm determinant of the sinc kernel is also evaluated. An analytic solution of a special ease of the fifth Painlev~ transcendent is then worked out explicitly.

关键词： of is exp in Generalised Error Functions from the Kerr Metric from

来源：评论

学校读者我要写书评

暂无评论

Multi-stage Algorithm of Estimation and Fault Diagnose for Closed-loop MIMO Gas Turbine Engine Systems

Multi-stage Algorithm of Estimation and Fault Diagnose for C...

引用

第27届中国控制与决策会议

作者： REN Jia MA Hong-jun Laboratory of Aeronautical Structures Impact Dynamics AVIC Aircraft Strength Research Institute Institute of Control Theory and Navigation Technology Northeastern University

ISBN: (纸本)9781479970162

Aircraft engines have characteristics with complex structure and prone to fault,in addition,conventional modeling methods based on mechanism analysis has troubles of complicated process and low operational *** solve these problems,an algorithm was proposed for identification and fault diagnose based on data,which could be used in closed-loop MIMO aircraft engine *** the algorithm,external input and output data of running closed-loop system measured online by sensors and data acquisition system were needed without understanding complexity construction and operation *** choosing appropriate auxiliary parameters,auxiliary models were *** time delay was calculated by determining the order of the auxiliary model,parameters of forward channels and feedback channels were estimated by multi-stage least square *** illustrative example of biaxial gas turbine engine system was given for *** the same time,the algorithm can be used for diagnosing gas path fault when the forgetting factor was changing by convergence of recognition result,the fault values can be got at ***,two kinds of important characteristics were introduced,about importance and principium of selecting forgetting factor and excluding disturb of noises by distinguish it by the result of fault.

关键词： Aircraft engine MIMO system closed-loop identification fault diagnose auxiliary model least square

来源：评论

学校读者我要写书评

暂无评论

Multi-stage algorithm of estimation and fault diagnose for closed-loop MIMO gas turbine engine systems 27

Multi-stage algorithm of estimation and fault diagnose for c...

引用

27th Chinese control and Decision Conference, CCDC 2015

作者： Jia, Ren Ma, Hong-Jun Laboratory of Aeronautical Structures Impact Dynamics AVIC Aircraft Strength Research Institute Xi'An China Institute of Control Theory and Navigation Technology Northeastern University Shenyang China

ISBN: (纸本)9781479970179

Aircraft engines have characteristics with complex structure and prone to fault, in addition, conventional modeling methods based on mechanism analysis has troubles of complicated process and low operational efficiency. To solve these problems, an algorithm was proposed for identification and fault diagnose based on data, which could be used in closed-loop MIMO aircraft engine systems. Using the algorithm, external input and output data of running closed-loop system measured online by sensors and data acquisition system were needed without understanding complexity construction and operation process. By choosing appropriate auxiliary parameters, auxiliary models were established. Then time delay was calculated by determining the order of the auxiliary model, parameters of forward channels and feedback channels were estimated by multi-stage least square algorithm. An illustrative example of biaxial gas turbine engine system was given for simulation. At the same time, the algorithm can be used for diagnosing gas path fault when the forgetting factor was changing by convergence of recognition result, the fault values can be got at last. Finally, two kinds of important characteristics were introduced, about importance and principium of selecting forgetting factor and excluding disturb of noises by distinguish it by the result of fault. © 2015 IEEE.

关键词： Aircraft engine auxiliary model closed-loop identification fault diagnose least square MIMO system

来源：评论

学校读者我要写书评

暂无评论

research and design of MEMS disk resonator gyroscope

Research and design of MEMS disk resonator gyroscope

引用

2016 China International Conference on Inertial technology and navigation

作者： LIU Zhao-yang ZHANG Wei-ping TANG Jian XING Ya-liang OU Bin CHENG Yu-xiang ZHAO Wan-liang LI Shao-liang Key Laboratory of Science and Technology on Micro/Nano Fabrication Laboratory Laboratory for Thin Film and Micro fabrication of the Ministry of EducationShanghai Key Lab of Navigation and Location-based ServicesDepartment of Micro-Nano ElectronicsSchool of electronic information and electrical engineeringShanghai Jiao Tong University Shanghai Institute of Spaceflight Control Technology Shanghai Engineering Research Center of Inertia

In this paper,a type of disk resonator gyroscope was designed and manufactured based on a pair of degenerate bulk acoustic wave modes in the field of Micro-Electro-Mechanical System(MEMS).It was used to aim at detecting an angular velocity with Coriolis *** gyroscope was completely symmetrical disc structure with a high degree of symmetry,which made the micro gyroscope frequency split very *** resonator was made of high performance piezoelectric material,thus improving the performance of the power *** structure and principle of the gyroscope were introduced and then the structure parameters of the resonator were optimized using the finite element analysis method,the distribution of the signal electrodes was also *** analyzer showed that the resonant frequency was about 280.8 k Hz and frequency split were very *** last,the micro gyroscope resonator was fabricated by using the micro-nano process *** signal electrodes were patterned,and the metal electrodes were fabricated on the top and bottom surface of the piezoelectric *** micro gyroscope prototype was obtained.

关键词： MEMS gyroscope disk resonant design

来源：评论

学校读者我要写书评

暂无评论

Application of Multimodal Strategy in AC Servo System

Application of Multimodal Strategy in AC Servo System

引用

International Conference on Intelligent Human-Machine Systems and Cybernetics, IHMSC

作者： Hao Min Jin Gong College of Mechanical Engineering Nanjing University of Science & Technology Nanjing Jiangsu Province China Department of Inertial Technology Navigation and Control Technology Research Institute Beijing China

ISBN: (纸本)9781479986477

For these characteristics that load variation and multiple interference in high-power AC servo system, the paper used multi-modal intelligent control algorithm which is combined with the Bang-Bang control, fuzzy PID control and the single neuron control. The paper designs a Multi-mode controller to realize the position control of AC servo system, to meet the fast system response speed, high positional accuracy and strong robustness requirements. The simulation results show that the controller is able to obtain good control quality.

关键词： Servomotors Neurons Mathematical model Hysteresis motors PD control Torque

来源：评论

学校读者我要写书评

暂无评论

Sliding-mode propulsion-control tests on a motion flight simulator

Sliding-mode propulsion-control tests on a motion flight sim...

引用

作者： Alwi, H. Edwards, C. Stroosma, O. Mulder, J.A. University of Exeter DevonEX4 4QF United Kingdom Delft University of Technology HS Delft2629 Netherlands College of Engineering Mathematics and Physical Sciences United Kingdom International Research Institute for Simulation Motion and Navigation Netherlands Control and Simulation Division Faculty of Aerospace Engineering Netherlands

This paper describes a fault-tolerant sliding-mode control allocation scheme capable of coping with the loss of all control surfaces resulting from a failure of the hydraulics system, during which time the scheme only uses the engines to control the aircraft. The paper presents tests of the scheme implemented on a six-degree-of-freedom motion research flight simulator at Delft University of technology, using a realistic maneuver involving an emergency return to a near-landing condition on a runway in response to the failure. The simulator results show that not only does the controller provide high tracking performance during nominal fault-free conditions, this performance is also maintained after the total loss of all control surfaces. This shows the capability of the proposed sliding-mode control allocation scheme to achieve and maintain desired performance levels using only propulsion by redistributing the control signals to the engines when failures occur. Copyright © 2013 by the American institute of Aeronautics and Astronautics, Inc. All rights reserved.

关键词： Flight simulators

来源：评论

学校读者我要写书评

暂无评论

Space QUEST mission proposal: Experimentally testing decoherence due to gravity

arXiv

引用

arXiv 2017年

作者： Joshi, Siddarth Koduru Pienaar, Jacques Ralph, Timothy C. Cacciapuoti, Luigi McCutcheon, Will Rarity, John Giggenbach, Dirk Lim, Jin Gyu Makarov, Vadim Fuentes, Ivette Scheidl, Thomas Beckert, Erik Bourennane, Mohamed Bruschi, David Edward Cabello, Adan Capmany, Jose Carrasco-Casado, Alberto Diamanti, Eleni Dusek, Miloslav Elser, Dominique Gulinatti, Angelo Hadfield, Robert H. Jennewein, Thomas Kaltenbaek, Rainer Krainak, Michael A. Lo, Hoi-Kwong Marquardt, Christoph Milburn, Gerard Peev, Momtchil Poppe, Andreas Pruneri, Valerio Renner, Renato Salomon, Christophe Skaar, Johannes Solomos, Nikolaos Stipčević, Mario Torres, Juan P. Toyoshima, Morio Villoresi, Paolo Walmsley, Ian Weihs, Gregor Weinfurter, Harald Zeilinger, Anton Zukowski, Marek Ursin, Rupert Institute for Quantum Optics and Quantum Information Austrian Academy of Sciences Boltzmanngasse 3 ViennaA-1090 Austria Centre for Quantum Computation & Communication Technology Department of Physics University of Queensland St LuciaQLD4072 Australia European Space Agency Keplerlaan 1 - P.O. Box 299 AG Noordwijk ZH2200 Netherlands Department of Electrical and Electronic Engineering University of Bristol Merchant Venturers Building Woodland Road BristolBS8 1UB United Kingdom German Aerospace Center Institute of Communications and Navigation Muenchner Strasse 20 Wessling82234 Germany Institute for Quantum Computing Department of Electrical and Computer Engineering University of Waterloo WaterlooONN2L 3G1 Canada Institute for Quantum Computing Department of Physics and Astronomy University of Waterloo WaterlooONN2L 3G1 Canada Precision Engineering Department Fraunhofer IOF Albert-Einstein-Straße 7 Jena07745 Germany Physics department Stockholm University Albanova universitetscentrum Universitetsvägen 10 Stockholm114 18 Sweden York Centre for Quantum Technologies Department of Physics University of York HeslingtonYO10 5DD United Kingdom University of Seville SevillaE-41012 Spain iTEAM Research Institute Universitat Politcnica de Valencia Valencia46022 Spain 4-2-1 Nukui-Kitamachi Koganei Tokyo184-8795 Japan CNRS Universite Pierre et Marie Curie Paris75005 France Department of Optics Faculty of Science Palacky University 17. Iistopadu 12 Olomouc772 00 Czech Republic Max Planck Institute for the Science of Light Bldg. 24 Günther-Scharowsky Str. 1 ErlangenD-91058 Germany Piazza Leonardo da Vinci 32 Milano20133 Italy School of Engineering University of Glasgow GlasgowG12 8LT United Kingdom Vienna Center of Quantum Science and Technology Faculty of Physics University of Vienna Boltzmanngasse 5 ViennaA-1090 Austria NASA Goddard Space Flight Center GreenbeltMD20771 United States Center for Quantum Information and Quantum Con

Models of quantum systems on curved space-times lack sufficient experimental verification. Some speculative theories suggest that quantum properties, such as entanglement, may exhibit entirely different behavior to purely classical systems. By measuring this effect or lack thereof, we can test the hypotheses behind several such models. For instance, as predicted by Ralph and coworkers [T C Ralph, G J Milburn, and T Downes, Phys. Rev. A, 79(2):22121, 2009;T C Ralph and J Pienaar, New Journal of Physics, 16(8):85008, 2014], a bipartite entangled system could decohere if each particle traversed through a different gravitational field gradient. We propose to study this effect in a ground to space uplink scenario. We extend the above theoretical predictions of Ralph and coworkers and discuss the scientific consequences of detecting/failing to detect the predicted gravitational decoherence. We present a detailed mission design of the European Space Agency's (ESA) Space QUEST (Space - Quantum Entanglement Space Test) mission, and study the feasibility of the mission scheme. Copyright © 2017, The Authors. All rights reserved.

关键词： Quantum entanglement

来源：评论

学校读者我要写书评

暂无评论

Determination of Atomic Number Densities of ^87Rb and ^3He Based on Absorption Spectroscopy

引用

Chinese Physics Letters 2014年第10期31卷 53-56页

作者：郑慧婕全伟刘翔陈瑶陆吉玺 Science and Technology on Inertial Laboratory Beihang University Beijing 100191 Fundamental Science on Novel Instrument & Navigation System Technology Laboratory Beihang University Beijing 100191 Shanghai Aerospace Control Engineering Research Institute Shanghai 200233

The atomic number densities of ^87 Rb vapor and surrounding gas 3He in a sealed cubic cell were measured by sweeping the absorption line and fitting the experimental data with a Lorentzian profile. The absorption was carried out around the D1 transition at different temperatures. We compare our results for the number density for^87 Rb with the previous methods and calculate the fractional error to be less than 5% as well as the error for ^3He between this work and the density obtained from the filling procedure to be no more than 4.2% at 370K. In addition, we discuss the factors that contribute to the error, among which the cell temperature plays the most important role.

关键词： ATOMIC absorption spectrum ATOMIC absorption spectroscopy MAGNETIC fields LORENTZIAN function ATOMIC number RUBIDIUM

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：