中国科学院机构知识库网格系统: 检索

Effect of Facet Displacement on Radiation Field and Its Application for Panel Adjustment of Large Reflector Antenna 期刊论文 OAI收割
Chinese Journal of Mechanical Engineering, 2017, 卷号: 30, 期号: 3, 页码: 578-586
作者: Wang, Wei; Lian, Peiyuan; Zhang, Shuxin; Xiang, Binbin; Xu, Qian

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收藏 | 浏览/下载：50/0 | 提交时间：2019/12/09

Reflector antennas Surface accuracy Radiation field Reflector antenna mechanical factors Electromechanical effects Panel adjustment Singular value decomposition (SVD) microwave holography surface measurement radio telescope deformation metrology matrix Engineering

Stable isotopic observation of water use sources of Pinus sylvestris var. mongolica in Horqin Sandy Land, China EI期刊论文 OAI收割
2013
Wei Y. F.; Fang J.; Liu S.; Zhao X. Y.; Li S. G.

收藏 | 浏览/下载：15/0 | 提交时间：2014/12/31

Forestry Arid regions Groundwater Isotopes Soil moisture Value engineering Water supply

Image mosaic technique based on the information of edge (EI CONFERENCE) 会议论文 OAI收割
2012 3rd International Conference on Digital Manufacturing and Automation, ICDMA 2012, July 31, 2012 - August 2, 2012, Guilin, Guangxi, China
作者: Wang Y.-Q.

收藏 | 浏览/下载：35/0 | 提交时间：2013/03/25

Image mosaic is an important branch in the field of image processing. This paper designs and realizes an image mosaic technique based on the information of edge. The technology is suitable for engineering application. First of all two images of the adjoining frames are processed by convolution operation get the edge images. And then we cut edge image into pieces and compute their spatial frequency. According to the value of the spatial frequency select reasonable registration model group. We compute correlation strength and the value of movement offset which are the model group and the current frame edge image. We can complete image mosaic by them. We use video sequence which of the resolution is 1024 * 768 do the experiment. The results show that the method has good effect and strong adaptability. Algorithm is high efficiency which running time is 24 ms. It is suitable for real-time processing requirements of the application. This method is an effective mosaic technique which is suitable for engineering application. 2012 IEEE.

Tracking error estimate for theodolite based on general regression neural network (EI CONFERENCE) 会议论文 OAI收割
3rd international Conference on Manufacturing Science and Engineering, ICMSE 2012, March 27, 2012 - March 29, 2012, Xiamen, China
作者: Li M.

收藏 | 浏览/下载：23/0 | 提交时间：2013/03/25

To efficiently evaluate the tracking index of theodolite as well as avoiding influence resulted from higher harmonics when used opto dynamic target and use equivalent sine to evaluate the tracking index in this paper we resorted to General Regression Neural Network to do the new research on theodolite tracking accuracy evaluation method. Experimental results indicate that the method realized the equivalent sine to evaluate the tracking index of theodolite and avoided the higher harmonics influence with opto dynamic target. The research in this paper has important value to the engineering practice. (2012) Trans Tech Publications.

Tracking error modeling of the theodolite based on GRNN method (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Frontiers of Manufacturing and Design Science, ICFMD 2011, December 11, 2011 - December 13, 2011, Taichung, Taiwan
作者: Li M.

收藏 | 浏览/下载：25/0 | 提交时间：2013/03/25

To meet the requirement of high tracking accuracy as well as develop more reasonable evaluation method in this paper the General Regression Neural Network (GRNN) has been applied to build the tracking error model of the theodolite. First we analyze the nonlinear factors in the theodolite. Second we discuss the principle of GRNN including its structure the function as well as its priors. Third we build the tracking error model based on GRNN and verify the model through the different parameters. The result indicated that the network model based on GRNN has high accuracy and good generalization ability. It could instead the real system to a certain extent. The research in this paper has important value to the engineering practice.

Drip irrigation of waxy corn (Zea mays L. var. ceratina Kulesh) for production in highly saline conditions EI期刊论文 OAI收割
2012
作者: Jiang Shufang; Wan Shuqin

收藏 | 浏览/下载：33/0 | 提交时间：2012/11/23

Subirrigation Cultivation Electric conductivity Forestry Leaching Salinity measurement Soils Value engineering Water supply

Design of control system of DC motor based on fusion FPGA (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Mechatronics and Materials Processing, ICMMP 2011, November 18, 2011 - November 20, 2011, Guangzhou, China
Zhu D. D.; Li H. W.

收藏 | 浏览/下载：34/0 | 提交时间：2013/03/25

Along with the development of microelectronic process it is possible to integrate a big system in one chip. A new way to implement system on a chip is provided by the advent of FPGA. Based on Verilog HDL and the Actel Fusion AFS600 FPGA chip the speed closed-loop control system of DC motor was designed by using options of combining the top-down thinking and the bottom-up method. PID control algorithm encoder signal processing and PWM waveform generation etc were realized by the system. The results show that the system structure is simplified and the stability and reliability are improved. A solution of system on a chip is realized to some extent. It has extensive application value in engineering practice. 2011 Trans Tech Publications.

Research on servo controller for high speed tracking system (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Mechatronic Systems and Automation Systems, MSAS 2011, July 23, 2011 - July 24, 2011, Xi'an, China
作者: Li M.

收藏 | 浏览/下载：17/0 | 提交时间：2013/03/25

To meet requirement of swiftness and minimization for the tracking system as well as realize horizontal high accuracy tracking measurement the automatic servo tracking measurement system has been designed. The two closed loop control bisection method and compound control have been applied into the system. Experimental results show that the maximum tracking error can be limited to less than 0.5and the regulator time can be 0.04s. The control project resonance frequency should be more than 200Hz and the sample frequency should be more than 400Hz to meet the control accuracy requirement. And these specific mechanical properties indexes are useful to mechanical working to make sure the design can be realization. So the research in this paper has important value to the engineering practice. (2011) Trans Tech Publications.

Research on the laboratory radiometric calibration of the thermal imager (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: Wang J.; Liu Y.; Liu Y.; Liu Y.; Sun Q.

收藏 | 浏览/下载：26/0 | 提交时间：2013/03/25

The radiometric calibration of the thermal imager was investigated to build the relationship between the input radiance and the digital output to realize the temperature measurement. The radiometric calibration was implemented in the State Key Laboratory of Applied Optics. A standard black body source was served as radiation source. The response of the thermal imager to the input radiance was tested for different gains. The experimental results show that the average grey level of the output imaging is linear dependence of the input radiance. Because the radiance in the receiving wave range of the thermal imager is linear with the black body's temperature based on Planck's law of radiation the average grey level of the output image is also linear with the black body's temperature after fitting a curve to the experiment data points. Then the relationship of the response and the gain was studied when the black body's temperature kept constant. The preliminary analysis of calibration data shows that the response of the thermal imager is linear and the average grey value of the image is directly proportion to the gain. According to the experimental results the reference gains and the dynamic range of temperature measurement were obtained. Finally the uncertainty influencing the calibration results was analyzed the analysis shows the maximal uncertainty is 5.2% which can meet the calibration requirement less than 10%. 2010 Copyright SPIE - The International Society for Optical Engineering.

Influence of spatial temperature distribution on high accuracy interferometric metrology (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: Yang H.; Zhang J.; Zhang J.; Zhang J.; Yan F.

收藏 | 浏览/下载：27/0 | 提交时间：2013/03/25

We calculate the influence of temperature change on the refractive index of air establish a model of air temperature distribution and analyze the effect of different temperature distribution on the high accuracy interferometric metrology. First a revised Edlen formula is employed to acquire the relation between temperature and refractive index of air followed by introducing the fixed temperature gradient distribution among the spatial grid within the optical cavity between the reference flat and the test flat of the Fizeau interferometer accompanied by a temperature change random function within each grid. Finally all the rays through the air layer with different incident angles are traced by Matlab program in order to obtain the final output position angle and OPD for each ray. The influence of different temperature distribution and the length of the optical cavity in on the testing accuracy can be analyzed through the RMS value that results from repeatable rays tracing. As a result the horizontal distribution (vertical to optical axis) has a large effect on the testing accuracy. Thus to realize the high accuracy figure metrology the horizontal distribution of temperature must be rigorously controlled as well as to shorten the length of the optical cavity to a large extent. The results from our simulation are of great significant for the accuracy analysis of interferometric testing and the research of manufacturing a interferometer. 2010 Copyright SPIE - The International Society for Optical Engineering.