scholarly journals Aspects of using a numerical simulator for a robot position-orientation matrix determination

2020 ◽  
Vol 1426 ◽  
pp. 012044
Author(s):  
C O Miclosina ◽  
I Halalae
Keyword(s):  
Orientation Matrix ◽  
Robot Position ◽  
Numerical Simulator

A new method of complex structure analysis by electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 628-629
Author(s):  
V.V. Rybin ◽  
E.V. Voronina
Keyword(s):  
Complex Structure ◽  
Reciprocal Lattice ◽  
Stacking Faults ◽  
Plastic Strains ◽  
Base Position ◽  
Structural Regularity ◽  
Orientation Matrix ◽  
Computerized Processing ◽  
Fully Automatic ◽  
Diffraction Patterns

Recently, it has become essential to develop a helpful method of the complete crystallographic identification of fine fragmented crystals. This was maainly due to the investigation into structural regularity of large plastic strains. The method should be practicable for determining crystallographic orientation (CO) of elastically stressed micro areas of the order of several micron fractions in size and filled with λ>1010 cm-2 density dislocations or stacking faults. The method must provide the misorientation vectors of the adjacent fragments when the angle ω changes from 0 to 180° with the accuracy of 0,3°. The problem is that the actual electron diffraction patterns obtained from fine fragmented crystals are the superpositions of reflections from various fragments, though more than one or two reflections from a fragment are hardly possible. Finally, the method should afford fully automatic computerized processing of the experimental results.The proposed method meets all the above requirements. It implies the construction for a certain base position of the crystal the orientation matrix (0M) A, which gives a single intercorrelation between the coordinates of the unity vector in the reference coordinate system (RCS) and those of the same vector in the crystal reciprocal lattice base : .

scholarly journals Research of Calibration Method for Industrial Robot Based on Error Model of Position

2021 ◽  
Vol 11 (3) ◽  
pp. 1287
Author(s):  
Tianyan Chen ◽  
Jinsong Lin ◽  
Deyu Wu ◽  
Haibin Wu
Keyword(s):  
Coordinate System ◽  
Industrial Robot ◽  
Calibration Method ◽  
Error Model ◽  
Position Error ◽  
Industrial Robots ◽  
Positioning Error ◽  
Robot Position ◽  
General Measurement ◽  
Parameter Error

Based on the current situation of high precision and comparatively low APA (absolute positioning accuracy) in industrial robots, a calibration method to enhance the APA of industrial robots is proposed. In view of the "hidden" characteristics of the RBCS (robot base coordinate system) and the FCS (flange coordinate system) in the measurement process, a comparatively general measurement and calibration method of the RBCS and the FCS is proposed, and the source of the robot terminal position error is classified into three aspects: positioning error of industrial RBCS, kinematics parameter error of manipulator, and positioning error of industrial robot end FCS. The robot position error model is established, and the relation equation of the robot end position error and the industrial robot model parameter error is deduced. By solving the equation, the parameter error identification and the supplementary results are obtained, and the method of compensating the error by using the robot joint angle is realized. The Leica laser tracker is used to verify the calibration method on ABB IRB120 industrial robot. The experimental results show that the calibration method can effectively enhance the APA of the robot.

scholarly journals CONCURRENT MAP BUILDING AND LOCALIZATION ON INDOOR DYNAMIC ENVIRONMENTS

2002 ◽  
Vol 16 (03) ◽  
pp. 361-374 ◽  
Author(s):  
JUAN ANDRADE-CETTO ◽  
ALBERTO SANFELIU
Keyword(s):  
Learning Rule ◽  
Dynamic Environments ◽  
Position Estimation ◽  
Indoor Environments ◽  
Map Building ◽  
Robust Learning ◽  
Map Construction ◽  
Map Updating ◽  
Dynamic Map ◽  
Robot Position

A system that builds and maintains a dynamic map for a mobile robot is presented. A learning rule associated to each observed landmark is used to compute its robustness. The position of the robot during map construction is estimated by combining sensor readings, motion commands, and the current map state by means of an Extended Kalman Filter. The combination of landmark strength validation and Kalman filtering for map updating and robot position estimation allows for robust learning of moderately dynamic indoor environments.

Reversible displacive phase transition in [Ni(en)3]2+(NO3−)2: a potential temperature calibrant for area-detector diffractometers

2003 ◽  
Vol 36 (1) ◽  
pp. 141-145 ◽  
Author(s):  
L. J. Farrugia ◽  
P. Macchi ◽  
A. Sironi
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Low Temperature ◽  
Potential Temperature ◽  
Rapid Decrease ◽  
Data Sets ◽  
Area Detector ◽  
Displacive Phase Transition ◽  
Orientation Matrix ◽  
Bruker Smart Apex

The coordination complex [Ni(en)3]2+(NO{}_{3}^{- })2(en = 1,2-diaminoethane) undergoes a sharp reversible displacive phase transition at ∼109 K, changing space group fromP6322 above the transition temperature toP6522 below. The phase change is accompanied by a tripling of thecaxis on cooling, resulting in an easy detection of the transition in images from area-detector diffractometers. The transition has been followed using a Nonius KappaCCD and a Bruker SMART APEX CCD. Data sets were collected over the temperature range 100–113 K and integrated using the low-temperature orientation matrix. Reflections withl≠ 3nshow a smooth and rapid decrease in intensity to zero on warming from 106.5 to 111 K. The results are reproducible to within ±2 K in two laboratories and suggest that this compound may be useful as a liquid-nitrogen cryo-calibrant for diffraction instruments equipped with area detectors.

The financial services cultural orientation matrix

2013 ◽  
Vol 21 (1) ◽  
pp. 1-9
Author(s):  
Deborah Stephenson ◽  
Steve Worthington ◽  
Rebekah Russell-Bennett
Keyword(s):  
Financial Services ◽  
Cultural Orientation ◽  
Orientation Matrix

scholarly journals Numerical Analysis on Steam Exciting Force Caused by Rotor Eccentricity

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
L. H. Cao ◽  
J. X. Wang ◽  
P. Li ◽  
P. F. Hu ◽  
Y. Li
Keyword(s):  
Pressure Fluctuation ◽  
Exciting Force ◽  
Width Ratio ◽  
Leakage Flow ◽  
Steam Turbines ◽  
Labyrinth Seals ◽  
Full Circle ◽  
Exciting Vibration ◽  
Numerical Simulator ◽  
Main Factor

The steam exciting force has been proved to be great threat to the operation safety of steam turbines. The mechanism of steam exciting vibration cannot be profoundly revealed by simply analyzing the steam exciting force, especially in simplified models. Therefore, a full-circle stage of steam turbine with shroud and labyrinth seals was investigated by numerical simulator CFX. The instability of leakage flow and the pressure fluctuation were analyzed on the eccentric condition. The effects of leakage vortexes, the depth-width ratio of seal cavity, and the eccentricity on the steam exciting force were studied. Results show that the leakage flow is nonuniform in the circumferential direction with the change of front teeth vortexes, which causes the steam exciting force. The tangential and radial steam exciting force both increase with the eccentricity increasing. The effects of the depth-width ratio of seal cavity on the two forces are different. In addition, the pressure fluctuation caused by the leakage vortexes on the shroud surfaces is a main factor inducing the steam exciting force. This research provides a theoretical guidance for the operation safety and optimization of steam turbines.

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