中国科学院机构知识库网格系统: 检索

Problems of modern Ar-40/Ar-39 geochronology: Reviews 期刊论文 OAI收割
ACTA PETROLOGICA SINICA, 2014, 卷号: 30, 期号: 2, 页码: 326-340
作者: Wang Fei; Shi WenBei; Zhu RiXiang

|

收藏 | 浏览/下载：23/0 | 提交时间：2018/09/26

Ar-40/Ar-39 and U-Pb methods Accuracy and error Closure temperature and thermochronology Excess argon in yang and high-pressure samples

Error analysis of the micro temperature control system (EI CONFERENCE) 会议论文 OAI收割
2012 International Conference on Measurement, Instrumentation and Automation, ICMIA 2012, September 15, 2012 - September 16, 2012, Guangzhou, China
Han Z.; Song K.

收藏 | 浏览/下载：48/0 | 提交时间：2013/03/25

In order to improve the measurement accuracy of optical detection instruments temperature control circuits for narrow band-pass filters are given and the error analysis is applied to temperature control circuits.The principle of a temperature measurement circuit is studied and the method of a driver circuit is described. A variety of influencing factors of temperature control accuracy are discussed. Moreover for these error factors improvement measures are given to reduce the nonlinear error. Finally circuit parameter error is quantified to propose a calculation method for margin of error in a temperature control system. (2013) Trans Tech Publications Switzerland.

Structural design of large aperture rectangular mirror for space telescope (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Civil Engineering and Transportation, ICCET 2012, October 27, 2012 - October 28, 2012, Guilin, China
作者: Li Z.; Li Z.

收藏 | 浏览/下载：43/0 | 提交时间：2013/03/25

Structural design of large aperture mirror is one of the key technologies for space telescope development. To meet the requirements of high stiffness strength and thermal dimensional stability some factors such as support scheme materials selection lightweight design and flexible support design were taken into account. The three supports location of the mirror was determined according to the modal analytical solution. By adjusting the parameters of flexure hinge influences of gravity assembly stress and thermal stress on the mirror were reduced obviously. Finite element analysis (FEA) results indicate that the surface accuracy reach to rms10.2nm and 10.8nm under the gravity along optical axis direction and 5C uniform temperature rise respectively the fundamental frequency of the mirror component is 268Hz. Dynamics test shows that the first order natural frequency is 256Hz which shows an error less than 5% compared to FEA results. (2013) Trans Tech Publications Switzerland.

Centroid localization algorithm based on bicubic interpolation gray square weighted (EI CONFERENCE) 会议论文 OAI收割
2012 3rd International Conference on Advances in Materials and Manufacturing Processes, ICAMMP 2012, December 22, 2012 - December 23, 2012, Beihai, China
作者: Zhou J.

收藏 | 浏览/下载：152/0 | 提交时间：2013/03/25

The 3D coordinates of measured point is embodied in 2D image coordinate of the optical characteristic point via the visual measurement system. Based on the gray square weighted centroid localization algorithm the paper presents bicubic interpolation gray square weighted centroid localization algorithm increases the number of effective pixels around the optical characteristic point imaging center and reduces noise error via the gray square weighted improves the imaging center location accuracy of optical characteristic point realizes the accurate location of the optical characteristic points. Results indicate application of the proposed algorithm to location the standard tolerance along the direction of x is 0.0022 Pixel the standard tolerance along the direction of y is 0.0023 Pixel compared with the others the standard tolerance is minimum and discrete to a lesser degree distancing ideal image point that is the proposed algorithm has higher location accuracy. The maximum tolerance along the direction of x is 0.008 Pixel the one along the direction of y is 0.007 Pixel compared with the other two algorithms the maximum tolerance is minimum.Results indicate that the stability of the proposed algorithm is better. (2013) Trans Tech Publications Switzerland.

Accuracy synthesis of a 3-RPS parallel robot based on manufacturing costs (EI CONFERENCE) 会议论文 OAI收割
31st Chinese Control Conference, CCC 2012, July 25, 2012 - July 27, 2012, Hefei, China
Yao T.-K.; Xi Z.; Feng Z.; Zhang L.-M.; Yong W.

收藏 | 浏览/下载：32/0 | 提交时间：2013/03/25

Pose accuracy is an important issue for parallel robot being used as mirror supporting system of telescope. One challenging topic is the accuracy synthesis which deals with the optimal design of the manufacturing and assembling tolerances of each component under the given pose accuracy. First the error model of the 3-RPS parallel robot is built based on total derivation of the kinematic equations. And the error variable of each spherical or rotate joint can be expressed as a single boundary error parameter but not three independent position parameters. Then the accuracy synthesis model is formulated taking the manufacturing costs as the optimization objective and the accuracy requirements as the constraint condition. Finally the genetic algorithm is used to solve the optimization problem and a simulation example is given. The results show that the accuracy synthesis method based on manufacturing costs can satisfy the need of pose accuracy and is better for engineering application than the method based on error sensitivity. 2012 Chinese Assoc of Automati.

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：29/0 | 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.

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.

Adaptive control at launching using three loop autopilot (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：25/0 | 提交时间：2013/03/25

In order to guarantee the precise initial flight trajectory control the missile disturbance of large disturbance torque three loop adaptive autopilot was researched. The characteristics of the projectile and three loop autopilot instruction formation characteristics were analysed. From equivalent pitching angle of lateral acceleration feedback loop combined with the instruction of generalized error autopilot structure was simplified and three loop autopilot adaptive control law and stability were designed. The test data show that when disturbance torque was 600Nm the attitude angle generalized error was -4.4. In the time lasted about 15s late trajectory accuracy was within 1.0.Three loop autopilot adaptive control law was able to control the disturbance of initial trajectory and adapt to dynamic characteristics changes control system stability. It was the initial trajectory accurate solution method of flight. 2011 IEEE.

Design and optimization of supporting structure for scanning mirror in aviation remote sensor (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electric Information and Control Engineering, ICEICE 2011, April 15, 2011 - April 17, 2011, Wuhan, China
作者: Yang H.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

An optical supporting structure is studied to improve its structure stiffness and reduce the rotate error to meet the requirement of aviation remote sensor. A formula to calculate fundamental frequency is proposed using Rayleigh-Ritz method and a method of is analyzed. By means of OPTISTRUCT software the maximum fundamental frequency is converted to object function the deformation under the gravity and the mass are assigned to state variable wall thicknesses of the structure are converted to design variables. The analysis and test results indicate that the fundamental frequency of designed optical supporting structure has been improved 37.2 Hz from 96.9 Hz which guarantee the reliability of the sweep mechanism and the rotate error is 4.89 which is satisfied for the rotate accuracy in plunge angle. The method of optimization has a certain instructional significance for the design of supporting structures in aviation remote sensor. 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.