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浏览/检索结果: 共8条,第1-8条 帮助

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Design of DC Magnet Power Supply System for ITER Static Magnetic Field Test Facility 期刊论文  OAI收割
IEEE TRANSACTIONS ON PLASMA SCIENCE, 2022
作者:  
Deng, Xi;  Jiang, Li;  Huang, Ya;  Gao, Ge
  |  收藏  |  浏览/下载:41/0  |  提交时间:2022/12/23
Tunnel pressure wave investigation with a new moving model rig 会议论文  OAI收割
Cagliari, Sardinia, Italy , 5-8 April 2016
作者:  
Yang GW(杨国伟);  Song JH(宋军浩);  Yang QS(杨乾锁);  Guo DL(郭迪龙)
  |  收藏  |  浏览/下载:36/0  |  提交时间:2018/11/08
Combustion characteristics of test and reserch on electronic control fuel injection system of cars GDI engine (EI CONFERENCE) 会议论文  OAI收割
2011 2nd International Conference on Mechanic Automation and Control Engineering, MACE 2011, July 15, 2011 - July 17, 2011, Inner Mongolia, China
Zhao X.; Xiong W.
收藏  |  浏览/下载:22/0  |  提交时间:2013/03/25
Image compression based on contourlet and no lists SPIHT (EI CONFERENCE) 会议论文  OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
作者:  
Zhang S.
收藏  |  浏览/下载:46/0  |  提交时间:2013/03/25
The volume of raw image data captured by the high resolution camera is extremely huge. Thus the efficient image compression method should be used to decrease the bit rate. The image compression method based on wavelet is used more widely nowadays. However  two dimensional wavelet is only the tensor product of the one dimensional wavelet whose support region of basis function is extended from interval to square. Contourlet is an image multiscale geometric analysis tool  which could represent image sparsely and has strong capability of nonlinear approximation. The basis function of contourlet is multidirectional and anisotropic. Nevertheless  contourlet is redundant. So the non-redundant Wavelet Based Contourlet Transform (WBCT) is used in this paper. The SPIHT algorithm is very efficient way to coding the significant coefficients. And the improved no lists SPIHT is more easy to implemented by hardware. Image compression method based on the combination of both wavelet based contourlet transform and no lists SPIHT coding is proposed in the paper. Experiment shows that compared to wavelet based scheme the contourlet scheme can reserve the texture of the image. For barbara test image when coding at low bit rate the PSNR can improve about 0.2dB. 2010 IEEE.  
High precision test method for dynamic imaging of space camera (EI CONFERENCE) 会议论文  OAI收割
2010 IEEE International Conference on Advanced Computer Control, ICACC 2010, March 27, 2010 - March 29, 2010, 445 Hoes Lane - P.O.Box 1331, Piscataway, NJ 08855-1331, United States
作者:  
Jin L.-X.;  Zhang K.;  Zhang K.;  Zhang K.;  Zhang K.
收藏  |  浏览/下载:26/0  |  提交时间:2013/03/25
A test method for dynamic imaging of space TDICCD (Time Delay and Integration Charge Coupled Devices) camera was presented in this paper. The test method adopted the PLL (Phase Locked Loop) technology and CMAC (Cerebella Model Articulation Controller) friction compensation as control strategy. Furthermore  According to this method  a test system for dynamic imaging of space TDICCD camera was designed and implemented. The system simulated the movement of the ground objects relative to the space aerocraft  to validate the capability of image speed match and the dynamic imaging quality of TDICCD camera. The design adopted a precision turntable and a drift turntable to simulate the movement around the earth and the drift motion in different latitude due to the rotation of earth  of the aerocraft. The turntables were drived by permanent magnet torque motor which was powered by PWM (Pulse Width Modulation). The system adopted DSP (Digital Signal Processor) as the control core and reached a very high performance. The experimental results showed that the steady speed error was better than 0.01 % and the instantaneous speed error reached 0.0267%. The precision of the test system designed met the requirement for dynamic imaging of TDICCD camera. 2010 IEEE.  
Modular aircraft simulation platform based on simulink (EI CONFERENCE) 会议论文  OAI收割
2010 IEEE International Conference on Mechatronics and Automation, ICMA 2010, August 4, 2010 - August 7, 2010, Xi'an, China
Chen C.-Q.; Ji Y.
收藏  |  浏览/下载:28/0  |  提交时间:2013/03/25
Aircraft simulation platform is the most important supporting technology in the aircraft development process. This simulation platform can be used for validating the design of subsystem and also it provides the necessary data for the Aircraft design. Wind has great impact on the flight parameter. In order to accurately simulate the wind model and calculate the flight parameters  a simulation modeling method for flight parameter simulation platform under wind field environment is established. Firstly  the various sub-systems which affecting flight parameters are analyzed  some mathematical models of the flight parameter simulation platform is established. Secondly  the atmospheric wind field is studied to analyze the impact on its trajectory. Then the model is built in the Simulink toolbox in the Matlab which is based on the principles of hierarchy and modularity  using C MEX S-function for the complex kinetic equations. Finally  when the models have been established  encapsulating models for several subsystem and assembling them for the Aircraft simulation platform based on the unified interface. The simulation tests (including the performance test of a certain gliding Aircraft  the wind influence test of a certain uncontrolled aircraft) prove the simulation capability of the platform  and its calculating step can reach 1 ms. Comparing simulation with field test data of a certain uncontrolled aircraft  it shows that the relative deviation of range is 0.47%  the relative deviation of maximal altitude is 2.1%. Taking relevant standards as a reference standard  it is demonstrated the platform is reliable  meets the engineering accuracy requirements. 2010 IEEE.  
Dynamic closed-loop test for real-time drift angle adjustment of space camera on the Earth (EI CONFERENCE) 会议论文  OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, April 26, 2010 - April 29, 2010, Dalian, China
作者:  
Xu S.;  Wang D.
收藏  |  浏览/下载:36/0  |  提交时间:2013/03/25
In order to eliminate the influence of aircraft attitude angle to the image quality of space camera  and assure that the drift angle of space camera could be accurately adjusted at the orbit  a novel closed-loop test method is provided for real-time drift angle adjustment of space camera on the Earth. A long focal length dynamic aim generator is applied to simulate the image motion and the variety drift angle  and to detect the precision of the image motion compensation machinery and the capability of the drift angle control system. The computer system is used to control the dynamic aim generator  accomplish the data processing  transmit and receive the data information. The seamless connection and the data transmission between the aim generator and the aircraft simulation devices are constituted. The command  parameter and drift angle data transmitted by the simulation devices are received by the space camera at the real time  then the photos are taken and the draft angle is adjusted simultaneously. It is shown that the drift angle can be accurately tracked by the space camera at the real time  and the detective method satisfies the test requirement. 2010 Copyright SPIE - The International Society for Optical Engineering.  
Analysis of inertia dyadic uncertainty for small agile satellite with control moment gyros (EI CONFERENCE) 会议论文  OAI收割
2010 IEEE International Conference on Mechatronics and Automation, ICMA 2010, August 4, 2010 - August 7, 2010, Xi'an, China
作者:  
Zhang L.;  Zhang L.;  Sun Z.
收藏  |  浏览/下载:20/0  |  提交时间:2013/03/25
With the increasing demands for the agility of the next earth imaging satellite  control moment gyro (CMG) is considered to be the most suitable actuator because of its torque amplification capability. However  a CMG system may introduce uncertainty of inertia dyadic to a satellite's attitude control system. The uncertainty is negligible for large space vehicles  but it has not been tested whether it can be ignored for small agile satellites. How to model the CMG system inertia dyadic varying with gimbal angles  and what influence it will put on the performance of attitude control system haven't been test accurately as well. All of them are dealt with mathematically and accurately in this paper. This paper firstly gives mathematic descriptions of the inertia dyadic of the 4-CMG pyramid configuration system  varying with gimbal angles  and then designs a variable structure control law for small agile satellite using CMGs. Finally  numerical simulation suggests that the inertia dyadic variation of a 4-CMG pyramid configuration system is approximately centesimal of the total inertia dyadic of the satellite  and that the designed variable structure control law is of good robust performance for an example of large-angle attitude maneuver  despite of the variation of the inertia dyadic. 2010 IEEE.