中国科学院机构知识库网格系统: 检索

A Local Image Enhancement Method Based on Adjacent Pixel Gray Order-preserving Principle 会议论文 OAI收割
5th International Symposium on Photoelectronic Detection and Imaging (ISPDI) - Infrared Imaging and Applications, Beijing, June 25-27, 2013
作者: Fan XP(范晓鹏); Cai TF(蔡铁峰); Zhu F(朱枫)

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The paper is committed in local image enhancement. At first, the authors propose an adjacent pixel gray order-preserving principle. Adjacent pixel gray order-preserving principle is the basement of local enhancement method which ensures that there is no distortion in processed image. And then, the authors propose an iterative algorithm, which could stretch gray-scale difference of adjacent pixels in premise of not changing gray magnitude relationship between adjacent pixels. At last, the authors propose a totally reference image quality assessment method based on adjacent pixel gray order-preserving principle. According to this quality assessment method, the authors made a set of comparative experiments with local histogram equalization and method. Experimental results show that the proposed enhancement method can get higher score and provide better visual effects, fully demonstrating its effectiveness. According to this quality assessment method, the proposed method shows a good effectiveness, through experimental results and comparison with local histogram equalization method.

Design of a miniature axial flux flywheel motor with PCB winding for nanosatellites (EI CONFERENCE) 会议论文 OAI收割
2012 International Conference on Optoelectronics and Microelectronics, ICOM 2012, August 23, 2012 - August 25, 2012, Changchun, China
Wu J.

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This paper presents the design and analysis of an axial flux permanent-magnet (AFPM) machine for nanosatellites application. It is a miniature axial flux surface mounted permanent magnet flywheel motor using a printed circuit board (PCB) stator winding. The PCB stator has simplified the design and construction and avoids unnecessary space since size reduction has become one of the most important aspects of flywheel motor design for nanosatellites. The performances of the machine are estimated by combination method of three-dimensional (3D) electromagnetic finite element analysis (FEA) and approximate theoretical analysis. The back EMF and electromagnetic torque are derived. A comparison between the analysis and experimental measurement results of the prototype machine is also presented. Both simulated and experimental results show that the proposed motor would be an acceptable solution for the nanosatellite applications with advantages such as simple structure and low-cost as multi-layer circuit board production techniques have made the production of printed circuit coils cheaper and easier. 2012 IEEE.

Space camera dynamic image quality measurement and evaluation (EI CONFERENCE) 会议论文 OAI收割
3rd International Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2011, January 6, 2011 - January 7, 2011, Shanghai, China
作者: Zhang X.; Zhang X.; Zhang X.

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By using analysis of the infinity image of the space camera we intend to obtain the curve of the dynamic modulation transfer function. We extract the pixel gray values at the image edge which distribute as a knife-edge function and make differential calculation and Fourier transformation of it and then we can obtain the dynamic MTF curve of the optical system. The value of the curve at the Nyquist frequency is the most important parameter that reflects the image quality. We add push-scanning imaging and environmental effects to the static MTF of space camera and compare the MTF value with the dynamic MTF at Nyquist frequency. The comparison result can help us verify the accuracy of the calculating results and the feasibility of our method. (2011) Trans Tech Publications.

An appraisal method of dynamic interpolation error for high precision encoder (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electronics and Optoelectronics, ICEOE 2011, July 29, 2011 - July 31, 2011, Dalian, China
作者: Wan Q.-H.; Liu C.-X.; Liu C.-X.

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This paper introduces an appraisal method of the dynamic interpolation error for the high precision encoder (Lissajou pattern calculation method). When the encoder is rolling two groups of fine photoelectric signals whose phase difference are /2 can be collected using data collected car. The shape and position deviation can be obtained through the comparison between Lissajou charts and the standard circle. Then dynamic interpolation error can be calculated out directly. This method is immune to the influence of encoder's speed and has no rigid demand to the test circumstances and test devices. The experimental results indicate that this method is feasible and important to the encoder's dynamic interpolation error checking. 2011 IEEE.

A fuzzy control method based on information integration for double inverted pendulum (EI CONFERENCE) 会议论文 OAI收割
2011 2nd International Conference on Digital Manufacturing and Automation, ICDMA 2011, August 5, 2011 - August 7, 2011, Zhangjiajie, Hunan, China
作者: Fan Y.

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This article proposes a new fuzzy controller based on information integration. The mathematical model of Linear double inverted pendulum has been studied and estabLished with dynamics analytical method and LQR theory is used to design the optimal Linear inverted pendulum controller then the integration technology is used to design the variable parameters self-tuning fuzzy controller. Thereby the fuzzy controller input variable dimension and the number of fuzzy control rules have been extremely reduced. Two controllers are designed for inverted pendulum system control and the comparison simulation experiments have been done. The results show that the controllers can both reaLize good control and the fuzzy controller has higher precision faster response better stabiLity and robustness. 2011 IEEE.

Random vibration analysis on the support of strapdown inertial navigation system (EI CONFERENCE) 会议论文 OAI收割
2nd Annual Conference on Electrical and Control Engineering, ICECE 2011, September 16, 2011 - September 18, 2011, Yichang, China
作者: Li M.

收藏 | 浏览/下载：27/0 | 提交时间：2013/03/25

Vibration of the support is an important factor to the accuracy of strapdown inertial navigation. To get vibration characteristics of the support FEM model of the support was created with Ansys and then response characteristics were analyzed on the support under the separated random loads during carrier flight including the phases of subsonic and subsonic. To validate the analysis method wide band random vibration test was done on the points of the support which are used for mounting inertial instruments. The comparison of the analysis and the test data shows that the relative error of analysis result is not more than 13%. According to the two results the support structure was improved. Finally random vibration analysis was carried out on the improved one. The result shows that the acceleration response was largely reduced than before. This research can be a reference of performance improvement of the strapdown inertial support and navigation system precision. 2011 IEEE.

The research of the accurate measure of static transfer function for the TDI CCD camera (EI CONFERENCE) 会议论文 OAI收割
3rd International Photonics and OptoElectronics Meetings, POEM 2010, November 2, 2010 - November 5, 2010, Wuhan, China
Guo-Ning L.; Long-Xu J.; Jian-Yue R.; Wen-Hua W.; Shuang-Li H.

收藏 | 浏览/下载：26/0 | 提交时间：2013/03/25

In the test course of static transfer function of TDI CCD camera because of the influence that gets environmental and artificial etc. factor the value of static transfer function measured at any time is between unceasing fluctuation so make accuracy reduce. To solve this problem a kind of accurate measurement technique of static transfer function is put forward. First before carrying out the measure of static quiet of transfer function the best test point of transfer function of the TDI CCD camera must be determined it is parallel to guarantee the rectangle target surface of parallel optical pipe and camera focal plane maintenance parallel and again guarantee target strip in rectangle target and TDI CCD in camera focal plane maintenance vertical. TDI CCD catches rectangle target image per 1000 lines of target mark image as a measures sample of static transfer function exclude because of atmosphere tremble twisted vague rectangle target mark image retain 500 distinct and steady target mark image as measure sample set. Then calculate the static transfer function of each measure sample respectively take the average of all static quiet transfer function in measure sample set as the static transfer function of camera. Finally the measure of the static transfer function for TDI CCD camera makes error analysis. Experimental results indicate that the value of the static transfer function of TDI CCD camera measured with this kind of method is 0.2923 with before measurement technique comparison the value of static transfer function has raised 0.02 makes the accuracy of the measure of static transfer function have gotten raising.

Roughness analysis of optical surfaces by X-ray scattering (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electronics and Optoelectronics, ICEOE 2011, July 29, 2011 - July 31, 2011, Dalian, China
作者: Chen B.

收藏 | 浏览/下载：26/0 | 提交时间：2013/03/25

A grazing incidence x-ray scattering (XRS) method Order perturbation theory (FOPT) is stated briefly and an experimental facility based on an improved X-ray diffraction has been introduced which can work with high performance. The x-ray scattering distributions of two super smooth silicon samples measured at the incidence angle 0.2 degree as the x-ray wavelength is 0.154 nm have been given and analyzed by the FOPT to give information about the surface profiles. As a comparison the root mean square (RMS) surface roughness grey-scale maps and one-dimensional power spectral density (1D PSD) have been derived from the atomic-force microscope (AFM) data. The results evaluated by FOPT are in good agreement with that of AFM which indicates that x-ray scattering method is a practical characterization for the investigation of super smooth surfaces. 2011 IEEE.

Analysis of a diffractive microlens using the finite-difference time-domain method (EI CONFERENCE) 会议论文 OAI收割
作者: Liu Y.; Liu H.; Liu H.; Liu H.; Liu Y.

收藏 | 浏览/下载：28/0 | 提交时间：2013/03/25

The finite-difference time-domain (FDTD) method is used as rigorous electromagnetic analysis model to calculate the field for a diffractive microlens (DML). The FDTD is used for the entire solution rather than using a near- to far-field propagation method to obtain the far-field energy distribution thus all the results are vector based. We derived a formula to calculate the magnitude of electric field which is time dependent and can be used to graphically show the light wave propagation and focusing process through a DML. Both the comparison and the integral methods are presented to obtain wave amplitude in full solution space and the distribution of light energy behind a DML is illustrated based on the wave amplitude. The formula of diffractive efficiency of the DML is derived from a time-averaged Ponyting vector which can indicate the propagation direction of light energy. Application of these formulations in the analysis of a DML example demonstrates the high accuracy and efficiency of our method. 2010 Society of Photo-Optical Instrumentation Engineers.

A new accurate and fast algorithm of sub-pixel image registration (EI CONFERENCE) 会议论文 OAI收割
2010 IEEE 10th International Conference on Signal Processing, ICSP2010, October 24, 2010 - October 28, 2010, Beijing, China
作者:

收藏 | 浏览/下载：27/0 | 提交时间：2013/03/25

In terms of large field view and multi-channel TDICCD remote sensing images previous interpolation methods and curve fitting methods are not able to achieve the high accuracy and fast registration and their noise immunity and robustness is not high. For that this paper presents a more accurate and faster method iterative pixel interpolation and surface fitting method. Firstly the method uses the some overlapping pixels between multi-channel images. Secondly the proposed technique which is based on the maximization of the correlation coefficient function combines an efficient pixel-moving interpolation scheme with surface fitting which makes use of accurate interpolation calculation and fast surface fitting in the iterative process. Finally the accuracy and speed of the algorithm is evaluated by sub-pixel registration of multi-channel images and comparison with other sorts of efficient methods. The experiment results show that the accuracy of the method reaches 0.01 pixels and it is 3 times faster than the interpolation method. In the registration of large field view and multi-channel TDICCD images the method is accurate and fast with greatly high stability noise immunity and robustness. 2010 IEEE.