中国科学院机构知识库网格系统: 检索

大口径主镜镜面朝下镀膜支撑优化设计 期刊论文 OAI收割
科学技术与工程, 2020, 卷号: 20, 期号: 23, 页码: 9367-9377
作者: 马民; 谭毅

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收藏 | 浏览/下载：26/0 | 提交时间：2021/05/11

2 m级SiC主镜参数化建模镀膜支撑 A-Frame支撑

2m SiC反射镜柔性被动支撑系统 期刊论文 OAI收割
光学精密工程, 2017, 页码: 2591-2598
作者: 王富国

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收藏 | 浏览/下载：43/0 | 提交时间：2018/04/09

Sic反射镜柔性被动支撑系统 Whiffletree A-frame

1.2m轻量化SiC主镜支撑系统优化设计 期刊论文 OAI收割
中国光学, 2012, 期号: 03, 页码: 229-234
邵亮; 杨飞; 王富国; 吴小霞

收藏 | 浏览/下载：20/0 | 提交时间：2013/03/11

轻量化SiC主镜支撑系统压杆结构 A-Frame

Improved TOPS about direction of arrival estimation for wideband signals (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Vibration, Structural Engineering and Measurement, ICVSEM2011, October 21, 2011 - October 23, 2011, Shanghai, China
作者: He B.

收藏 | 浏览/下载：17/0 | 提交时间：2013/03/25

The study about the direction-of-arrival (DOA) estimation for wideband signals is a basic topic of Signal Processing. The method called test of orthogonality of projected subspaces (TOPS) does not require initial values to form focusing matrix compared with the coherent signal subspace method (CSSM) but it has poor performance for coherent wideband signals at low signal-to-noise ratio (SNR). Based on the lack of the conventional TOPS this paper reconstructs a set of new matrices with the narrowband correlated matrices coming from the DFT decomposition of the array output and modifies the method frame of the conventional TOPS. So we get a set of reconstructed matrices with full rank corresponding to each frequency bin and which have no array aperture loss. The improved TOPS can estimate the DOA for coherent wideband sources at low SNR and enhances the performance of the conventional TOPS. Simulation results show that the improved TOPS is effective and the total performance of which is similar to the rotational signal-subspace (RSS) method. (2012) Trans Tech Publications.

Design of high speed and parallel compression system used in the big area CCD of high frame frequency (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Precision Engineering and Non-Traditional Machining, PENTM 2011, December 9, 2011 - December 11, 2011, Xi'an, China
作者: Li G.-N.; Jin L.-X.; Zhang R.-F.; Wang W.-H.; Li G.-N.

收藏 | 浏览/下载：51/0 | 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.

Design of motion adjusting system for space camera based on ultrasonic motor (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Space Exploration Technologies and Applications, May 24, 2011 - May 26, 2011, Beijing, China
作者: Sun Z.

收藏 | 浏览/下载：85/0 | 提交时间：2013/03/25

Drift angle is a transverse intersection angle of vector of image motion of the space camera. Adjusting the angle could reduce the influence on image quality. Ultrasonic motor (USM) is a new type of actuator using ultrasonic wave stimulated by piezoelectric ceramics. They have many advantages in comparison with conventional electromagnetic motors. In this paper some improvement was designed for control system of drift adjusting mechanism. Based on ultrasonic motor T-60 was designed the drift adjusting system which is composed of the drift adjusting mechanical frame the ultrasonic motor the driver of Ultrasonic Motor the photoelectric encoder and the drift adjusting controller. The TMS320F28335 DSP was adopted as the calculation and control processor photoelectric encoder was used as sensor of position closed loop system and the voltage driving circuit designed as generator of ultrasonic wave. It was built the mathematic model of drive circuit of the ultrasonic motor T-60 using matlab modules. In order to verify the validity of the drift adjusting system was introduced the source of the disturbance and made simulation analysis. It designed the control systems of motor drive for drift adjusting system with the improved PID control. The drift angle adjusting system has such advantages as the small space simple configuration high position control precision fine repeatability self locking property and low powers. It showed that the system could accomplish the mission of drift angle adjusting excellent. 2011 SPIE.

A new approach to realize UART (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electronic and Mechanical Engineering and Information Technology, EMEIT 2011, August 12, 2011 - August 14, 2011, Harbin, China
作者: Wang Y.; Wang Y.; Wang Y.; Wang Y.; Wang Y.

收藏 | 浏览/下载：34/0 | 提交时间：2013/03/25

In order to connect DSP which has synchronous serial ports to the devices implementing asynchronous communications protocol a method to implement UART communications based on programmable logic device is proposed in the paper. In the proposed method the core function of UART is integrated in CPLD with VHDL. Firstly UART data frame format and operational principle of UART were introduced after reviewing some methods to realize UART. The methods to implement UART transmitter UART receiver and baudrate generator using VHDL were illustrated in detail. Then pre-simulation and synthesize of VHDL program were executed. Finally the test with bit error rate was carried out on physical system. Experimental results indicate that 75 percent of the GLB are used by UART and the bit error rate is less than 109. The experiment was implemented utilizing the RS-422 protocol and the baudrate is 62.5kb/s. The proposed method can satisfy the system requirements of high integration stabilization low bit error rate strong anti-jamming and low cost. 2011 IEEE.

DVI interface, optical fiber video transceiver used in LED display system (EI CONFERENCE) 会议论文 OAI收割
2011 IEEE 3rd International Conference on Communication Software and Networks, ICCSN 2011, May 27, 2011 - May 29, 2011, Xi'an, China
作者: Wang R.; Li S.

收藏 | 浏览/下载：28/0 | 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.

Astronomical image restoration through atmosphere turbulence by lucky imaging (EI CONFERENCE) 会议论文 OAI收割
3rd International Conference on Digital Image Processing, ICDIP 2011, April 15, 2011 - April 17, 2011, Chengdu, China
作者: Zhao J.; Wang J.; Zhang S.

收藏 | 浏览/下载：27/0 | 提交时间：2013/03/25

In this paper we develop a lucky imaging system to restore astronomical images through atmosphere turbulence. Our system takes very short exposures on the order of the atmospheric coherence time. The rapidly changing turbulence leads to a very variable point spread function (PSF) and the variability of the PSF leads to some frames having better quality than the rest. Only the best frames are selected aligned and co-added to give a final image with much improved angular resolution. Our system mainly consists of five parts: preprocessing frame selection image registration image reconstruction and image enhancement. Our lucky imaging system has been successfully applied to restore the astronomical images taken by a 1.23m telescope. We have got clear images of moon surface and Jupiter and our system can be demonstrated to greatly improve the imaging resolution through atmospheric turbulence. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

Research on image restoration of Roll-Swing imaging seeker (EI CONFERENCE) 会议论文 OAI收割
3rd IEEE International Conference on Advanced Computer Control, ICACC 2011, January 18, 2011 - January 20, 2011, Harbin, China
作者: Zhang H.; Zhang H.

收藏 | 浏览/下载：28/0 | 提交时间：2013/03/25

To achieve a correct image receiving for Roll-Swing imaging seeker the mechanism and imaging process is analyzed. The causes of image rotation are discussed. The influence of the frame encoders' precision on imaging de-rotation quality is analyzed. The Roll-Swing imaging seeker is designed for high-speed aerocraft thus the received images are greatly degraded due to atmospheric turbulence. A new method of image restoration is proposed for turbulence-degraded images in this paper. The method is to get point spread function (PSF) based on the estimation of optical transfer function (OTF) according to the optical system design simulation. Finally to obtain the restored image constrained least squares filtering is used with the known PSF. The experiment results indicate that the new restoration method has a favorable effect to satisfy requirement of the automatic target recognition. 2011 IEEE.