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Structural design of large aperture rectangular mirror for space telescope (EI CONFERENCE) 会议论文
2nd International Conference on Civil Engineering and Transportation, ICCET 2012, October 27, 2012 - October 28, 2012, Guilin, China
Li Z.
收藏  |  浏览/下载：27/0  |  提交时间：2013/03/25
Structural design of large aperture mirror is one of the key technologies for space telescope development. To meet the requirements of high stiffness  strength and thermal dimensional stability  some factors such as support scheme  materials selection  lightweight design and flexible support design were taken into account. The three supports location of the mirror was determined according to the modal analytical solution. By adjusting the parameters of flexure hinge  influences of gravity  assembly stress and thermal stress on the mirror were reduced obviously. Finite element analysis (FEA) results indicate that the surface accuracy reach to rms10.2nm and 10.8nm under the gravity along optical axis direction and 5C uniform temperature rise respectively  the fundamental frequency of the mirror component is 268Hz. Dynamics test shows that the first order natural frequency is 256Hz  which shows an error less than 5% compared to FEA results. (2013) Trans Tech Publications  Switzerland.  
LABTM control system based on FPGA (EI CONFERENCE) 会议论文
2nd International Conference on Mechatronics and Applied Mechanics, ICMAM 2012, December 8, 2012 - December 9, 2012, Taiwan
Li X. F.; Wang X. P.; Qi X. D.; Wang Y.; Yu P.
收藏  |  浏览/下载：140/0  |  提交时间：2013/03/25
This paper presents the digital PI control method for design and simulation of a high precision limited angle brushless torque motor control system in Field Programmable Gate Array device (FPGA). The direct drive structures which are widely applied in many servo control fields. Matlab Xilinx System GeneratorR toolbox based on Fixed-Point Arithmetic is used to design the digital PI controller using DSP architecture  plot the responses of the control system and generate the VHDL source code. The control system model consists of a digital PI  a real LABTM  and a real absolute Inductosyn  encoder to rpm and position blocks. Through loading generated codes in process of the simulation that built by the digital discrete model  it is verified that the rising time of current loop is only 1.2ms  and rate loop is 8ms  overshoot is rarely 4.2%. Finally  the comprehensive positioning accuracy of system can reach up to 5 arc sec  and the rate jitter achieves 5% with the 4 arc sec accuracy absolute Inductosyn. (2013) Trans Tech Publications  Switzerland.  
Design of the real-time autofocusing system for collimator with long focus length and large aperture (EI CONFERENCE) 会议论文
2011 International Academic Conference on Numbers, Intelligence, Manufacturing Technology and Machinery Automation, MAMT 2011, December 24, 2011 - December 25, 2011, Wuhan, China
Li X.; Zhang X.
收藏  |  浏览/下载：34/0  |  提交时间：2013/03/25
Large aperture collimator which has been widely used for calibrating and testing various optical devices plays an essential role in correlative laboratories. As being the basic testing and calibration equipment  the large aperture collimator's accuracy should be much higher than the device under testing in order to ensure the accuracy of the measurement. However  the process of adjusting the collimator is extremely complicated due to the collimator's large aperture and long focal length. So it is difficult to ensure the measurement's quality and easy to cause the system being vulnerable to the surrounding environment. One of the most common problems is defocus. In order to solve the problem above  this issue presents a new type of autocollimator autofocusing system which uses pentaprism instead of using large-aperture plane mirror  semiconductor lasers as light source and CCD sensor as receiver. The system is smaller  lighter  and more convenient when using. The computer simulation shows that the autofocusing system's resolution could reach the accuracy of 40m. If we use the relevant algorithms to execute the sub-pixel scanning  the resolution could reach the accuracy of 10m. It shows that the system could satisfy the required testing precision of testing large aperture optical device.  
Design of high speed and parallel compression system used in the big area CCD of high frame frequency (EI CONFERENCE) 会议论文
2011 International Conference on Precision Engineering and Non-Traditional Machining, PENTM 2011, December 9, 2011 - December 11, 2011, Xi'an, China
Liu Y.-Y.; Gao Y.-H.; Li G.-N.; Wang W.-H.; Zhang R.-F.; Jin L.-X.
收藏  |  浏览/下载：47/0  |  提交时间：2013/03/25
According to the area CCD camera of characteristics  such as high resolution capacity and high frame frequency  this paper puts forward a high speed and parallel image compression system of high integration degree. Firstly  according to the work principle of the area CCD  FPGA is adopted to realize the timing driving and multichannel and parallel analog signal handling to raise the export frame frequency of the area CCD. Secondly  with an image compression scheme based on FPGA embedded processor MicroBlaze and ADV212 compression chip  real time image compression and the high speed area CCD are realized. Finally  by detecting the analog signal of the area CCD output  the real time compression of the big area CCD image is carried out in different compression ratios and the compression performance is analyzed. Experiment result shows that this scheme can realize real time image compression with the biggest data rate of 520Mbps. When compression bit ratio is 0.15  the signal-to-noise ratio of peak value can reach 36 dB. Image collection and image compression are integrated  which reduces the data transmission between them and improves systematic integration degree.  
A novel miniature absolute metal rotary encoder based on Single-track Periodic Gray Code (EI CONFERENCE) 会议论文
2012 2nd International Conference on Instrumentation and Measurement, Computer, Communication and Control, IMCCC 2012, December 8, 2012 - December 10, 2012, Harbin, Heilongjiang, China
Wan Q.-H.; Wang Y.-Y.; Sun Y.; Yang S.-W.
收藏  |  浏览/下载：22/0  |  提交时间：2013/03/25
In order to improve the resolution and enhance the impact resistance and vibration resistance of encoders  a novel absolute metal rotary encoder based on Single-track Periodic Gray Code is presented. The configuration and working principle of the encoder is introduced  and then the metal code disc which can realize full scale absolute encoding on one single track and its corresponding metal slit disc are proposed. Finally  the data acquisition and processing system based on FPGA of encoder is presented. The resolution of the encoder can reach 5.27through electronic subdivision and calibration between the precision code and the coarse code with its volume only 4840mm. The encoder has some advantages such as small volume  low cost  high resolution and strong impact resistance. 2012 IEEE.  
The application of diagnostic equipment in the Tokamak fusion reaction (EI CONFERENCE) 会议论文
2011 International Conference on Optical Instruments and Technology: Optical Systems and Modern Optoelectronic Instruments, November 6, 2011 - November 9, 2011, Beijing, China
Zhang B.-S.; Chang J.; Gong X.-Z.; Gan J.-F.; Feng S.-L.
收藏  |  浏览/下载：11/0  |  提交时间：2013/03/25
This paper introduces the infrared optical system in the Tokamak fusion reaction device. In this optical system  3.the relay group lenses. This paper describes the decrease of the modulation transfer function (MTF) when the temperature changes and how to compensate the decrease of the MTF in order to maintain the image quality in a high level. As a result  the traditional optical structure can't meet the requirements  2.the Cassegrain system  the image quality of this optical system can reach the requirements when the temperature changes. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).  because the length of the infrared optical system in the Tokamak is very long. The design of optical system in the detection facility includes three parts:1.the combination of the concave aspheric mirror and flat mirror  
Structural design for lightweight off-axis TMA space telescope (EI CONFERENCE) 会议论文
2011 2nd International Conference on Digital Manufacturing and Automation, ICDMA 2011, August 5, 2011 - August 7, 2011, Zhangjiajie, Hunan, China
Xin H.; Li Z.
收藏  |  浏览/下载：27/0  |  提交时间：2013/03/25
Research on lightweight outer baffle for coaxial space camera (EI CONFERENCE) 会议论文
2011 International Conference on Electronic and Mechanical Engineering and Information Technology, EMEIT 2011, August 12, 2011 - August 14, 2011, Harbin, China
Zhang L.; Yao J.; Jia X.; Jin G.
收藏  |  浏览/下载：15/0  |  提交时间：2013/03/25
Stray light is non-imaging light that reach the optical system imaging plane. The non-imaging light can be received by detector if it is not effectively controlled  and stray light which directly irradiates on the detector has great influence on the imaging quality. Stray light can be effectively inhibited  if the outer baffle of space camera is designed optimally. Carbon fiber composite material is chosen as main material to meet requirements of a coaxial space optical system. The outer baffle should have advantages  such as lightweight  high stiffness and dimensional stability  etc. Using optimization design tools  the lightweight outer baffle is designed. And finite element method is used to check the structure. Development and test results show that the outer baffle with a diameter of 620mm and a total length of 1200mm only weighs 7.3kg. And the baffle's natural frequency reaches 88Hz  and it can satisfy the requirements of the space camera. 2011 IEEE.  
DVI interface, optical fiber video transceiver used in LED display system (EI CONFERENCE) 会议论文
2011 IEEE 3rd International Conference on Communication Software and Networks, ICCSN 2011, May 27, 2011 - May 29, 2011, Xi'an, China
Li S.; Wang R.
收藏  |  浏览/下载：19/0  |  提交时间：2013/03/25
A professional DVI-Video optical fiber transceiver was designed based on FPGA (Field Programmable Gate Array) in order to meet the need of real-time LED display. The system could be used to transmit a non-loss  real-time video source whose resolution was 1024 768 and refresh rate was 60Hz in a single mode optical fiber. The top-down design method was used while programming FPGA. Some module design ideas were discussed including video data acquisition  caching  framing  frame detecting and video reproducing. The required bandwidth of each module was analyzed and calculated in details. Some relevant simulation results were also given. In practical test  real-time video display was achieved. And the transmission rate of coded data was up to 2Gbps  and the transmission distance could reach 10km. 2011 IEEE.  
Study of experimental design and Response Surface method for surrogate model of computational simulation (EI CONFERENCE) 会议论文
2nd Annual Conference on Electrical and Control Engineering, ICECE 2011, September 16, 2011 - September 18, 2011, Yichang, China
Xi R.; Jia H.; Xiao Q.
收藏  |  浏览/下载：18/0  |  提交时间：2013/03/25
While the high-precision simulation is widely used in science and technology  Design of Experiment (DOE) based on Response Surface (RS) method can be employed in surrogate model to reduce the cost and error. In order to illustrate the relationship between parameters and response features  several DOE methods and Response Surface (RS) method are studied. The author used polynomial regression and RBF neural network based on orthogonal array to build a rocket aerodynamic discipline surrogate model respectively which proved their feasibility. From the results of the test case  conclusion is drawn that characteristic as well as acclimatization of DOE methods and different approximation should be considered for different issues  so the factors of cost and accuracy could reach a balance synthetically. 2011 IEEE.  

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