中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
首页 机构 成果 学者
  
  1. CAS IR Grid
机构
采集方式
内容类型
发表日期
学科主题
筛选

浏览/检索结果: 共13条，第1-10条 帮助

条数/页： 排序方式：
Reflections and transmissions from a porous layer sandwiched between seawater and solid substrate 期刊论文  OAI收割
OCEAN ENGINEERING, 2023, 卷号: 288, 页码: 14
作者:  Yang, Chun;  Stovas, Alexey;  Wang, Yun;  Wang, Liheng
  |  收藏  |  浏览/下载：13/0  |  提交时间：2024/01/02
The research of round raster readheads scheme (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
Cong J.-F.
收藏  |  浏览/下载：31/0  |  提交时间：2013/03/25
Space optical remote sensor of the CAE thermal control index calculation method (EI CONFERENCE) 会议论文  OAI收割
2011 International Conference on Advanced Design and Manufacturing Engineering, ADME 2011, September 16, 2011 - September 18, 2011, Guangzhou, China
作者:  Li L.
收藏  |  浏览/下载：28/0  |  提交时间：2013/03/25
The thermal control indicators CAE methods of Space optical remote sensor are analyzed in the presented work. We sat up a thermal optical analysis model for space optical remote sensor. By assuming fully covered by in-orbit temperature load  and using the finite element method for thermal deformation analysis  we obtained the optical remote sensor surface deformation and displacement under various thermal loading. Using ZERNIKE polynomial  wave was fitted to obtain ZERNIKE polynomial coefficients which were incorporated into the optical system design. Using CODE V optical calculation software  heat-ray machines under elastic deformation of the system point spread function  transfer function (MTF)  wave front differential (WFE) etc. were calculated. Image quality changes of remote sensors are discussed in variety assumed cases such as temperature loads of quality change. By repeated iteration  critical value of temperature fields meeting the design requirements are obtained for the optical system. Optical indicators were converged to the temperature field indicator  then reasonable indicators of thermal control for remote sensors were obtained. For the thermal control design  this method provided a reliable basis for design. (2011) Trans Tech Publications  Switzerland.  
Design of stable image platform on airborne camera (EI CONFERENCE) 会议论文  OAI收割
2011 International Conference on Advanced Design and Manufacturing Engineering, ADME 2011, September 16, 2011 - September 18, 2011, Guangzhou, China
作者:  Yang L.;  Yang L.
收藏  |  浏览/下载：16/0  |  提交时间：2013/03/25
Modulation transfer function resulting from random vibration was analyzed. To conclude that the effect of angular displacement was the major factor. Allowable MTF degradation was represented  and 34dB reduction was achieved at frequency of 100HZ. With the help of MSC.ADAMS simulation software  and convert allowable MTF degradation into stable system design parameters  simulated curve proves correct for isolator  which can guide perfect design for stabilization system. Based on the spatial mechanism and translational principle of parallelogram  and the irrotational displacement mechanism was tested by optical method  an irrotational displacement isolator was developed. It can meet the requirements of irrotational displacement and damp. An instance was given  coupled angle is less than 8?  it can satisfy the demand of aerial imaging. (2011) Trans Tech Publications.  
Research on the the device of non-angular vibration for opto-electronic platform (EI CONFERENCE) 会议论文  OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Smart Structures and Materials in Manufacturing and Testing, April 26, 2010 - April 29, 2010, Dalian, China
An Y.; Song C.-P.; Kuang R.-J.; Jin G.
收藏  |  浏览/下载：32/0  |  提交时间：2013/03/25
The opto-electronic platform is the main equipment for aviation reconnaissance. It is a surveillance system with the function of search  recognition orientation and tracking by opto- electronic instruments. It is made up of opto-electronic instruments which are used to get high quality image  and stabilization tracking system to control stabilization and gesture of platform for exact tracking. The opto-electronic platform purpose is to achieve high quality image. Besides the impact of optic system  the image quality of the system is influenced greatly in the vibration environment. The research worked by Zhao peng which demonstrated the affection caused by angular vibration was worse than which caused by line vibration  and what was multiplied direct ratio with plane altitude. So it is necessary to design a new device which could be used widely and has good angular vibration isolation effect. According to the theory of parallelogram  the non-angular vibration device had been designed with spatial links  and the theory of non-angular vibration was analyzed. The three-dimensional model was set with UG  the analysis was done by ADAMS/vibration software. The acceleration and displacement response of the device in each direction was calculated by inspiriting it with sine wave of the acceleration in three directions  and the stiffness and damp were studied. All the work prove the design principle of the device is reasonable  and the device is adopted to keep the platform motion moving horizontally  at the meantime the device is good at isolating vibration in all directions. 2010 SPIE.  
Far-field focusing of laser beam based on digital image processing techniques (EI CONFERENCE) 会议论文  OAI收割
Optoelectronic Imaging and Multimedia Technology, October 18, 2010 - October 20, 2010, Beijing, China
作者:  Zhao S.;  Tian Y.-Z.;  Liu L.-S.;  Guo J.;  Zhang H.-Y.
收藏  |  浏览/下载：27/0  |  提交时间：2013/03/25
In order to lead the laser beam transmit in the atmosphere convergently  an experiment of laser focus at the distance of 450m and 300m has been operated in the outdoor place. The actual manipulations are as follows: Firstly  the laser was collimated by a beam expander  then the near-parallel laser beam was transmitted with a Galileo telescope system  and the distance between the concave lens and the convex lens can be tuned through a precise displacement platform  so the focus of the system changed due to the tiny displacement of the concave lens. Secondly  the average power of the laser spot can be measured using power meter  the power is 47.67mW and the standard deviation is 0.67mW while the focal length is 450m. Thirdly  the energy distribution was found through the laser beam analyzer. The spot images were saved using the beam analyzer  then the saved image can be processed with Matlab software afterwards. The function named EDGE and Sobel operator was used in the pre-processing of the saved image  then method of median filter was used in the course of image de-noising and 53H filter was adopted in the signal analysis. The diameter of laser spot was obtained by the method above  the diameter is 5.56mm and the standard deviation is 0.24mm. The spot center excursion is 0.56mm  it is 10.43% of the total diameter of the laser spot. At last  the key factors of the energy dissipation in the focusing system can be summarized as follows: restriction of the diffraction limit  attenuation in the atmosphere  geometrical aberration of optical system  and the diffraction limit and the geometrical aberration are significant in the three factors above  so we can reduce the impact of the both factors during the design of optical system. The reliable referenced data of the system design can be acquired through the primary experiment research. 2010 SPIE.  
Research of active supporting technology based on 400mm thin mirror (EI CONFERENCE) 会议论文  OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, April 26, 2010 - April 29, 2010, Dalian, China
作者:  Liu X.-Y.;  Wang J.-L.;  Wang J.-L.;  Liu X.-Y.
收藏  |  浏览/下载：30/0  |  提交时间：2013/03/25
Using a spherical mirror of 400mm diameter and 12mm thickness  active supporting technology of thin mirror is researched. The axial support of the mirror is composed of 12 active supports and 3 fixed supports. The force actuator  which is composed of displacement actuator and force sensor  is installed in the active support. The mirror surface is tested by Zygo interferometer. For calibration  each actuator exerts unit force alone  and the surface variation is tested and taken as the response function of the actuator. The response functions of all actuators compose the stiffness matrix. Then the stiffness matrix is used by damped least square method to determine the correction force of each active support. In order to analyze the correction capability of the active supports  14 Zernike modes of the mirror surface are generated and tested respectively  and 7 modes are selected for correction. Initially  the RMS error of mirror surface is 1.16 I( =0.6328nm)when all actuators exert the same force. After 5 iterations  the RMS error of mirror surface is reduced to 0.13  close to the original surface quality. 2010 Copyright SPIE - The International Society for Optical Engineering.  
Modulation transfer function in seeker camera limits resulting from missile flutter caused by aerodynamic force (EI CONFERENCE) 会议论文  OAI收割
2010 2nd International Conference on Industrial Mechatronics and Automation, ICIMA 2010, May 30, 2010 - May 31, 2010, Wuhan, China
作者:  Zhang X.;  Zhang X.;  Zhang X.
收藏  |  浏览/下载：26/0  |  提交时间：2013/03/25
The imaging quality of seeker in flight mode has been evaluated through analyzing the effects of missile flutter on optical modulation transfer function (MTF) of the optical system. Firstly the data of transverse vibration has been processed to eliminate the trend term caused by the trajectory  then obtained the displacement with two times trapezoidal integration. For the side rotation  the high frequency noise interference in the data has been filtered by using five-point moving average method. Took this model as the quivering rule between the object and the image  and then analyzed the effects of the transverse vibration and the side rotation on imaging quality through MTF. By calculation  the r.m.s value of the image motion caused by missile transverse vibration is 0.026mm  and the side rotation angle is 0.0044 . Through the establishment of two modulation transfer functions (MTF) of image random vibration and linear vibration  the results show that the image quality had declined  and the effect of transverse vibration on image quality is obvious. Through improving the rigidity of the missile and selection of small focal length optical system and shorten the time of exposure can improve the imaging quality of the seeker. 2010 IEEE.  
The study of mapping relation of aeroplane complex motion and image movement and compensation technique (EI CONFERENCE) 会议论文  OAI收割
2010 International Conference on Computer Application and System Modeling, ICCASM 2010, October 22, 2010 - October 24, 2010, Shanxi, Taiyuan, China
Wei Z.; Wang Y.-Y.; Xue W.-Q.; Dai M.
收藏  |  浏览/下载：23/0  |  提交时间：2013/03/25
In order to solve the problem of image blurring due to the image motion which results from the aircraft's motion  attitude changes  and the relative motion of the camera and aircraft firstly  we install linear displacement transducer on the four shock absorbers. By analyzing the displacement values  the geometrical relationship between the camera and the aircraft is acquired  then relative motion amount between the object and the aircraft is obtained according to the motion and attitude changes. After that  making use of geometrical relationship  we can calculate the displacement variation of pixels within the camera exposure time. Thereafter  taking consider variable motion and non-linear motion as uniform motion in a straight line at the moment of imaging  then the model of the blurring image can be established according to the displacement variation of pixels within the camera exposure time  and fuzzy point spread function in the two-dimensional movement is built. By using Wiener filtering method with the optimal window  the image blurring is eliminated in aerial imaging system. Practice proved that this method can effectively eliminate the image blurring in the aerial imaging system. 2010 IEEE.  
Fuzzy system models (FSMs) for analysis of rock mass displacement caused by underground mining in soft rock strata 期刊论文  OAI收割
EXPERT SYSTEMS WITH APPLICATIONS, 2009, 卷号: 36, 期号: 3, 页码: 4637-4645
作者:  Wen-Xiu, Li;  Hai-Ning, Li
收藏  |  浏览/下载：27/0  |  提交时间：2017/04/11