中国科学院机构知识库网格系统: 检索

A novel method of evaluating the lift force on the bluff body based on Noca's flux equation 期刊论文 OAI收割
CHINESE PHYSICS B, 2015, 卷号: 24, 期号: 8, 页码: 84701
作者: Sui XK(隋相坤); Jiang N(姜楠)

收藏 | 浏览/下载：28/0 | 提交时间：2016/01/08

flux equation lift force experimental error

Application of trend extrapolation method to spectrum analysis of microtremor signal (EI CONFERENCE) 会议论文 OAI收割
2nd World Congress on Computer Science and Information Engineering, CSIE 2011, June 17, 2011 - June 19, 2011, Changchun, China
Zhou X.; Guo T.; Jiao J.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

The trend extrapolation method is applied to spectrum analysis of microtremor signal in order to increase the spectral estimation accuracy. First establish an appropriate extrapolation model based on the existing data series and then fit correlation functions other than existing data by derivative least squares method finally perform spectrum analysis using extrapolated correlation functions. Numerical simulations and the experimental results show that good results are achieved no matter correlation functions change slow or rapid and the extrapolation error is not more than 2.3%. 2012 Springer-Verlag Berlin Heidelberg.

Surface shape optimization for the space membrane reflector (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:

收藏 | 浏览/下载：23/0 | 提交时间：2013/03/25

Space membrane reflector is very promised for optical quality application with the merits of ultra-lightweight and flexible. In order to improve the surface precision of membrane reflectors the formation and surface shape error of a membrane at uniform load are studied based on the henky-cambell equations of circular membrane. The ANSYS software is used to build an optimization model of membrane reflector surface shape in which the yield strength is the state variable the surface load on ten concentric annular regions of the mirror is the design variable and the minimum RMS between ideal surface and mirror surface is the target function. and the theoretical and experimental result show that RMS and PV of the optimized surfaces are reduced respectively than those before optimization. In a word this paper offers the theoretical and experimental basis of the polyimide membrane reflector. 2011 IEEE.

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.

收藏 | 浏览/下载：19/0 | 提交时间：2013/03/25

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.

Compensation of moire fringe sinusoidal deviation in photoelectrical encoder based on tunable filter (EI CONFERENCE) 会议论文 OAI收割
2011 Symposium on Photonics and Optoelectronics, SOPO 2011, May 16, 2011 - May 18, 2011, Wuhan, China
作者: Wang Y.; Wang Y.; Wang Y.; Wang Y.; Wang Y.

收藏 | 浏览/下载：31/0 | 提交时间：2013/03/25

In order to improve the precision of the absolute photoelectrical encoder a compensating method is put forward which restrains the harmonics in moire fringe signal. After analyzing the relationship between the subdividing error and the sinusoidal index a low-pass digital filter which can make the moire signal satisfy the need of 1024 subdivision is designed. Considering with the fundamental frequency varies with the rotating speed of encoder the tunable filter is adopted whose cutoff frequency is calculated according to the coarse information of the encoder. The simulating results show that the proposed method can improve the sinusoidal index especially at high rotating speed. At last the compensating algorithm is implemented in the terminal of satellite optical communication which needs high resolution. The experimental results show indicate that the developed method is feasible. 2011 IEEE.

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：38/0 | 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.

Analyse the angular velocity estimation errors of -- filter based on high sampling rate (EI CONFERENCE) 会议论文 OAI收割
2011 2nd International Conference on Mechanic Automation and Control Engineering, MACE 2011, July 15, 2011 - July 17, 2011, Inner Mongolia, China
作者: Zhang Y.

收藏 | 浏览/下载：31/0 | 提交时间：2013/03/25

In order to get angular velocity of stabilization servo mechanism from angular position sensors -- filter based on high sampling rate was established model and error characteristics were analyzed. With the hypothesis of constant acceleration -- filter and its angular velocity transfer function were deduced. Combing with optimum parameters the effects of and sample rate on the error characteristics were evaluated. According to the requirements of stabilization servo mechanism the frequency characteristics of angular velocity transfer function are analyzed and the filter parameters are designed. The experimental which filter tracked and smoothed sinusoidal signal the results show that when the cutoff frequency of angular velocity loop is 44.9rad/s sampling period and parameters are 0.08ms and 0.01279 respectively the phase leading of angular position is 70. -- filter tracked sinusoidal signals with maximum angular velocity(30/s) and maximum angular acceleration(30/s2) the error of angular velocity estimation was 0.053/s. In the engineering of electro-optical stabilization servo mechanism -- filter can reduce noise effectively and reached the requirement of platform angular velocity estimation. Also it is one of the effective methods to get angular velocity from angular position sensors. 2011 IEEE.

Data processing method of multi-position strap-down north seeking system based on SVD (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Mechatronic Science, Electric Engineering and Computer, MEC 2011, August 19, 2011 - August 22, 2011, Jilin, China
Shen C.-W.; Liu C.; Yu S.-B.; Wang Z.-Q.; Li J.-R.

收藏 | 浏览/下载：38/0 | 提交时间：2013/03/25

With the aim to fit the sin wave curve of a multi-position strap-down north seeking system and to calculate the real north angle accurately the principles of the system and the algorithm of singular value decomposition(SVD) are introduced. The factors influencing the measuring precision are also analyzed. Then the algorithm is adopted to fit curves. Experimental results indicate that the singular value decomposition is very precise for its error sum is 1.1102V and the squared error is 2.8mV. Moreover for phase angle measurement measured six times in same direction the squared error is 24 (1). The method based on SVD can satisfy the system precision requirements of curve-fitting north seeking systems. 2011 IEEE.

A nanometer scale alignment method of concentric spherical mirrors based on interferometry (EI CONFERENCE) 会议论文 OAI收割
4th IEEE International Nanoelectronics Conference, INEC 2011, June 21, 2011 - June 24, 2011, Tao-Yuan, Taiwan
作者: Xu T.

收藏 | 浏览/下载：16/0 | 提交时间：2013/03/25

A nanometer scale alignment method of spherical concentric mirrors based on dual-beam interferometry is proposed which is also the method to measure the defocus of concentric spherical mirrors. In the process of aligning the concentric spherical mirrors the defocus can be measured real time with nanometer scale error. The experimental result shows that the method can achieve the defocus of the spherical concentric mirrors several nanometers. 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.