Đánh giá quan hệ giữa hàm lượng hơi nước khí quyển và độ chính xác định vị tuyệt đối bằng GPS ở Việt Nam

2008 ◽  
Vol 30 (2) ◽  
pp. 161-169
Author(s):  
Lê Huy Mình ◽  
Phạm Xuân Thành ◽  
Nguyễn Chiến Thắng ◽  
Trần Thị Lan ◽  
R. Fleury ◽  
...  
Keyword(s):  
Water Vapour ◽  
Viet Nam ◽  
Absolute Positioning ◽  
The Absolute

Estimatlon of the relatlon between the total tropospheric water vapour and the precision of the absolute positioning by GPS in Vietnam

scholarly journals Kinematic Modeling of Six-Axis Industrial Robot and its Parameter Identification: A Tutorial

2021 ◽  
Vol 15 (5) ◽  
pp. 599-610
Author(s):  
Md. Moktadir Alam ◽  
◽  
Soichi Ibaraki ◽  
Koki Fukuda
Keyword(s):  
Present Model ◽  
Industrial Robot ◽  
Local Coordinate System ◽  
Kinematic Model ◽  
Kinematic Modeling ◽  
Positioning Accuracy ◽  
Rotary Axis ◽  
Model Based ◽  
Absolute Positioning ◽  
The Absolute

In advanced industrial applications, like machining, the absolute positioning accuracy of a six-axis robot is indispensable. To improve the absolute positioning accuracy of an industrial robot, numerical compensation based on positioning error prediction by the Denavit and Hartenberg (D-H) model has been investigated extensively. The main objective of this study is to review the kinematic modeling theory for a six-axis industrial robot. In the form of a tutorial, this paper defines a local coordinate system based on the position and orientation of the rotary axis average lines, as well as the derivation of the kinematic model based on the coordinate transformation theory. Although the present model is equivalent to the classical D-H model, this study shows that a different kinematic model can be derived using a different definition of the local coordinate systems. Subsequently, an algorithm is presented to identify the error sources included in the kinematic model based on a set of measured end-effector positions. The identification of the classical D-H parameters indicates a practical engineering application of the kinematic model for improving a robot’s positioning accuracy. Furthermore, this paper presents an extension of the present model, including the angular positioning deviation of each rotary axis. The angular positioning deviation of each rotary axis is formed as a function of the axis’ command angles and the direction of its rotation to model the effect of the rotary axis backlash. The identification of the angular positioning deviation of each rotary axis and its numerical compensation are presented, along with their experimental demonstration. This paper provides an essential theoretical basis for the error source diagnosis and error compensation of a six-axis robot.

scholarly journals Improvement and Assessment of the Absolute Positioning Accuracy of Chinese High-Resolution SAR Satellites

2019 ◽  
Vol 11 (12) ◽  
pp. 1465
Author(s):  
Deng ◽  
Zhang ◽  
Cai ◽  
Xu ◽  
Zhao ◽  
...  
Keyword(s):  
High Resolution ◽  
Propagation Delay ◽  
Reference Points ◽  
Calibration Model ◽  
Land Resource ◽  
Positioning Accuracy ◽  
Geometric Calibration ◽  
Atmospheric Propagation ◽  
Absolute Positioning ◽  
The Absolute

In recent years, China has launched YaoGan-13 and GaoFen-3, high-resolution synthetic aperture radar (SAR) satellites that can acquire global high-resolution images. The absolute positioning accuracy of such satellites is important for mapping areas without ground reference points and for automated processing. However, satellites without geometric calibration have poor absolute positioning accuracy, greatly restricting their application (e.g., land resource surveys). Therefore, they cannot meet national demands for high-resolution SAR images with good geometric accuracy. Here, we propose a series of methods to improve the absolute positioning accuracy of YaoGan-13 and GaoFen-3, such as the multiple-image combined calibration strategy and geometric calibration model for a real continuously moving configuration, including consideration of atmospheric propagation delay. Using high-accuracy ground control data collected from different areas, the 2-D and 3-D absolute positioning accuracies of YaoGan-13 and GaoFen-3 were assessed after implementation of the improvement measures. Experimental results showed that, after calibration, the 2-D absolute positioning accuracy of YaoGan-13 and GaoFen-3 are improved from 43.86 m to 2.57 m and from 30.34 m to 4.29 m, respectively. In addition, the 3-D absolute positioning accuracies of YaoGan-13 in plane and elevation are 3.21 m and 2.22 m, respectively. Improving the absolute positioning accuracy of these satellites could broaden the scope of their potential applications in the future.

Solid-gas equilibrium in the binary system lithium iodide-water

1981 ◽  
Vol 46 (13) ◽  
pp. 3157-3165 ◽  
Author(s):  
Jiřina Hejtmánková ◽  
Čestmír Černý ◽  
Luděk Jettmar
Keyword(s):  
Binary System ◽  
Water Vapour ◽  
Temperature Interval ◽  
Thermodynamic Functions ◽  
Dynamic Method ◽  
Heats Of Formation ◽  
Lithium Iodide ◽  
Gibbs Energies ◽  
Flow Apparatus ◽  
The Absolute

An investigation has been made of the equilibria of hydration in the system solid lithium iodide-water vapour in the temperature interval covering the range of existence of the solid hydrates, using a dynamic method in a flow apparatus. From measured equilibrium pressures, the changes of the thermodynamic functions accompanying these reactions were determined and the values of the heats of formation, of the Gibbs energies of formation and of the absolute entropies of the solid mono-, di- and trihydrate of lithium iodide at 298.15 K were calculated.

scholarly journals VLBA H2O and SiO maser observations in the pPN OH 231.8+4.2

2007 ◽  
Vol 3 (S242) ◽  
pp. 338-339
Author(s):  
J.-F. Desmurs ◽  
C. Sánchez Contreras ◽  
V. Bujarrabal ◽  
J. Alcolea ◽  
F. Colomer
Keyword(s):  
High Resolution ◽  
Water Vapour ◽  
Planetary Nebulae ◽  
Absolute Position ◽  
Long Baseline ◽  
The Absolute ◽  
Very Long Baseline Array

AbstractWe report high-resolution observations of H2O, 61,6−52,3 and 28SiO v=2, J=1-0 maser emissions obtained with the Very Long Baseline Array in the bipolar pre-planetary nebulae OH 231.8+4.2 (see Desmurs et al., 2007). A phase referencing technique was used to recover the absolute position of both emissions. We detected two groups of water vapour emission oriented nearly north-south. SiO masers are tentatively found to be placed between the two H2O maser emitting regions.

scholarly journals A Competitive Analysis Of Top Ten Pharmaceutical Companies In India

Bionatura ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 1865-1872
Author(s):  
Anupam Saha ◽  
Arijit Das ◽  
Subhasish Dutta ◽  
Suprodip Mandal
Keyword(s):  
Competitive Analysis ◽  
Pharmaceutical Companies ◽  
Web Data ◽  
Absolute Positioning ◽  
The Absolute

Contemplating the activities and conduct of close contenders is fundamental. Competitive analysis is a significant piece of the vital arranging process, and the wellsprings of such Web data are enhanced, and the data are refreshed much of the time. This expansive intrigue has brought about different definitions and conceptualizations of recognizable contender proof just as different ways to deal with considering it, which disables the reconciliation of existing information planned for responding to fundamental inquiries regarding its revenue, procedures, and suggestions. To compete with the opposition organizations are against, it is essential to survey things that are genuinely working in the business. Inquire about rely upon measurable studying, which is limited most definitely and limit. There can be more recommendations, which can show profitability to the association. In this task, the top ten pharmaceutical organizations of India are firmly watched. The absolute positioning gives according to general income, i.e., overall revenue.

Microwave measurements of the absolute values of absorption by water vapour in the atmosphere

Nature ◽  
1979 ◽  
Vol 279 (5712) ◽  
pp. 408-409 ◽  
Author(s):  
D. C. HOGG ◽  
F. O. GUIRAUD
Keyword(s):  
Water Vapour ◽  
Microwave Measurements ◽  
The Absolute

scholarly journals A calibration method of robot kinematic parameters by drawstring displacement sensor

2019 ◽  
Vol 16 (5) ◽  
pp. 172988141988307 ◽  
Author(s):  
Yahui Gan ◽  
Jinjun Duan ◽  
Xianzhong Dai
Keyword(s):  
Calibration Method ◽  
Industrial Robots ◽  
Displacement Sensor ◽  
Kinematic Parameters ◽  
Position Measurement ◽  
Positioning Accuracy ◽  
End Effector ◽  
Displacement Sensors ◽  
Absolute Positioning ◽  
The Absolute

Calibration of robot kinematic parameters can effectively improve the absolute positioning accuracy of the end-effector for industrial robots. This article proposes a calibration method for robot kinematic parameters based on the drawstring displacement sensor. Firstly, the kinematic error model for articulated robot is established. Based on such a model, the position measurement system consisting of four drawstring displacement sensors is used to measure the actual position of the robot end-effector. Then, the deviation of the kinematic parameters of the robot is identified by the least-squares method according to robot end-effector deviations. The Cartesian space compensation method is adopted to improve the absolute positioning accuracy of the robot end-effecter. By experiments on the EFORT ER3A robot, the absolute positioning accuracy of the robot is significantly improved after calibration, which shows the effectiveness of the proposed method.

Research on Absolute Positioning Error of Robot Based on Mapping Theory

2014 ◽  
Vol 494-495 ◽  
pp. 1156-1160
Author(s):  
Guan Hua Dong ◽  
Ying Yin ◽  
Xiao Bing Hu
Keyword(s):  
Industrial Robots ◽  
Positioning Error ◽  
Positioning Accuracy ◽  
Compensation Algorithm ◽  
Absolute Positioning ◽  
The Absolute ◽  
Mapping Theory

Joint-typical Industrial robots tend to have higher repetitive positioning accuracy and lower absolute positioning accuracy. In order to improve the absolute positioning accuracy of robots, this paper puts forward a compensation algorithm based on the mapping theory combining with the kinematics equation, which establish the connection between the space of off-line programming and teaching-programming, so as to approximate the repeat positioning accuracy. A experiment is implemented to confirm its correctness, and the result shows that the supposed method can improve the absolute positioning accuracy heavily, which the absolute positioning error reduces from 8.32mm to 1.08mm.

The absolute positioning of spaceborne INSAR data using the integer ambiguity method

2006 ◽  
Vol 21 (113) ◽  
pp. 61-75 ◽  
Author(s):  
Andrew Sowter ◽  
Mark A. Warren ◽  
Richard M. Bingley
Keyword(s):  
Integer Ambiguity ◽  
Absolute Positioning ◽  
The Absolute
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