The Influence of Heat Exchanges on Friction in Robotic Joints: Theoretical Modelling, Identification and Experiments

2021 ◽  
Author(s):  
Roberto Pagani ◽  
Giovanni Legnani ◽  
Giovanni Incerti ◽  
Manuel Beschi ◽  
Monica Tiboni
Keyword(s):  
Theoretical Modelling ◽  
Robotic Joints ◽  
Heat Exchanges

The Influence of Heat Exchanges on Friction in Robotic Joints: Theoretical Modelling, Identification and Experiments

2020 ◽  
Author(s):  
Roberto Pagani ◽  
Giovanni Legnani ◽  
Giovanni Incerti ◽  
Manuel Beschi ◽  
Monica Tiboni
Keyword(s):  
Thermal Effects ◽  
Rotation Speed ◽  
Industrial Robot ◽  
Experimental Tests ◽  
Theoretical Modelling ◽  
Degree Polynomial ◽  
Identification Procedure ◽  
Good Reliability ◽  
Robotic Joints ◽  
Heat Exchanges

Abstract This paper presents a model that describes the effect of heat exchange on dynamic friction in the joints of an industrial robot. As concern the modeling of friction as a function of the rotation speed of the joint, a third degree polynomial is used. The coefficients of the polynomial, which depends on the temperature, are estimated by means of a suitable identification procedure. The proposed technique is simple to implement and economically convenient. Experimental tests have shown that the method here proposed, despite its simplicity, can estimate with good reliability the variations of friction that occur during the operation of an industrial robot due to thermal effects. Possible fields of application are the improvement of the friction compensation algorithms used for robot control systems and the prediction of energy consumption.

Some Problems in Understanding the Solar Corona

1994 ◽  
Vol 144 ◽  
pp. 1-9
Author(s):  
A. H. Gabriel
Keyword(s):  
Solar Corona ◽  
Solar Atmosphere ◽  
Theoretical Modelling ◽  
Total System ◽  
Major Advance ◽  
X Ray ◽  
Proper Perspective ◽  
Space Observations

The development of the physics of the solar atmosphere during the last 50 years has been greatly influenced by the increasing capability of observations made from space. Access to images and spectra of the hotter plasma in the UV, XUV and X-ray regions provided a major advance over the few coronal forbidden lines seen in the visible and enabled the cooler chromospheric and photospheric plasma to be seen in its proper perspective, as part of a total system. In this way space observations have stimulated new and important advances, not only in space but also in ground-based observations and theoretical modelling, so that today we find a well-balanced harmony between the three techniques.

Interlaboratory evaluation of theoretical modelling techniques for single-mode optical fibres

1992 ◽  
Vol 139 (5) ◽  
pp. 353 ◽  
Author(s):  
J. Pelayo ◽  
J. Paniello ◽  
N. Gisin ◽  
J.W. Burgmeijer ◽  
M. Blondel ◽  
...  
Keyword(s):  
Single Mode ◽  
Theoretical Modelling ◽  
Optical Fibres ◽  
Modelling Techniques

Numerical simulation of the tree higro-thermal response in forest fire environment

2020 ◽  
pp. 57-65
Author(s):  
Eusébio Conceiçã ◽  
João Gomes ◽  
Maria Manuela Lúcio ◽  
Jorge Raposo ◽  
Domingos Xavier Viegas ◽  
...  
Keyword(s):  
Forest Fire ◽  
Numerical Study ◽  
Thermal Response ◽  
View Factor ◽  
Tree Model ◽  
Pine Tree ◽  
Surface Temperatures ◽  
Fire Environment ◽  
Fire Front ◽  
Heat Exchanges

This paper refers to a numerical study of the hypo-thermal behaviour of a pine tree in a forest fire environment. The pine tree thermal response numerical model is based on energy balance integral equations for the tree elements and mass balance integral equation for the water in the tree. The simulation performed considers the heat conduction through the tree elements, heat exchanges by convection between the external tree surfaces and the environment, heat exchanges by radiation between the flame and the external tree surfaces and water heat loss by evaporation from the tree to the environment. The virtual three-dimensional tree model has a height of 7.5 m and is constituted by 8863 cylindrical elements representative of its trunks, branches and leaves. The fire front has 10 m long and a 2 m high. The study was conducted taking into account that the pine tree is located 5, 10 or 15 m from the fire front. For these three analyzed distances, the numerical results obtained regarding to the distribution of the view factors, mean radiant temperature and surface temperatures of the pine tree are presented. As main conclusion, it can be stated that the values of the view factor, MRT and surface temperatures of the pine tree decrease with increasing distance from the pine tree in front of fire.

Understanding of social behaviour in human collective motions with non-trivial rule of control

Impact ◽  
2019 ◽  
Vol 2019 (10) ◽  
pp. 84-86
Author(s):  
Keisuke Fujii
Keyword(s):  
Machine Learning ◽  
Team Sports ◽  
Machine Learning Techniques ◽  
Theoretical Modelling ◽  
Video Footage ◽  
Learning Techniques ◽  
Collective Motions ◽  
Tracking Movements ◽  
Or Team ◽  
Computational Ability

The coordination and movement of people in large crowds, during sports games or when socialising, seems readily explicable. Sometimes this occurs according to specific rules or instructions such as in a sport or game, at other times the motivations for movement may be more focused around an individual's needs or fears. Over the last decade, the computational ability to identify and track a given individual in video footage has increased. The conventional methods of how data is gathered and interpreted in biology rely on fitting statistical results to particular models or hypotheses. However, data from tracking movements in social groups or team sports are so complex as they cannot easily analyse the vast amounts of information and highly varied patterns. The author is an expert in human behaviour and machine learning who is based at the Graduate School of Informatics at Nagoya University. His challenge is to bridge the gap between rule-based theoretical modelling and data-driven modelling. He is employing machine learning techniques to attempt to solve this problem, as a visiting scientist in RIKEN Center for Advanced Intelligence Project.

Choice of Optimum Operational Regime for Total Stations upon Making Geodetic Surveys under Heavy Aerosol Atmosphere Pollution

2018 ◽  
Vol 938 (8) ◽  
pp. 12-19
Author(s):  
S. B. Verdiyev
Keyword(s):  
Rational Choice ◽  
Theoretical Modelling ◽  
Total Station ◽  
Visible Band ◽  
Multi Wavelength ◽  
Atmosphere Pollution ◽  
Experimental Researches ◽  
Practical Recommendations

The possibility to use multi-wavelength regime of total stations operation for making surveys under heavy aerosol atmosphere pollution is researched. The actuality of single- and multi-wavelength regimes rational choice under heavy aerosol atmosphere pollution is grounded. The task on researching the matter of operational regime choice for total stations is formulated. The method for solution of the formulated task is suggested. The theoretical modelling and experimental researches are held to formulate the criterion for choice of single- or multi-wavelength regimes. The practical recommendations for such a choice are formulated. The practical recommendations are formulated for choice of measurements regime. According to formulated recommendations if a single-wavelength total station operates in the field of longer wavelengths (R) of visible band and a three-wavelengths one operates with bias to shorter (B, G, R) wavelengths, the single-wavelength total station should be preferred. But if the single-wavelength total station operates in the field of shorter wavelengths (B) and the three-wavelengths one operates with bias to longer wavelengths (B, G, R) then the multi-wavelengths total station should be preferred. The recommendation described in this article are relevant for both the regimes of measurements with- and without reflector and can be useful for users of total stations.

Theoretical modelling of porous silicon decorated with metal atoms for hydrogen storage

2020 ◽  
Vol 45 (49) ◽  
pp. 26321-26333
Author(s):  
Israel González ◽  
Francisco De Santiago ◽  
Lucía G. Arellano ◽  
Álvaro Miranda ◽  
Alejandro Trejo ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Hydrogen Storage ◽  
Theoretical Modelling ◽  
Metal Atoms

scholarly journals Treadmilling FtsZ polymers drive the directional movement of sPG-synthesis enzymes via a Brownian ratchet mechanism

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Joshua W. McCausland ◽  
Xinxing Yang ◽  
Georgia R. Squyres ◽  
Zhixin Lyu ◽  
Kevin E. Bruce ◽  
...  
Keyword(s):  
Cell Wall ◽  
Single Molecule ◽  
Theoretical Modelling ◽  
Binding Potential ◽  
Central Component ◽  
Macromolecular Complex ◽  
Bacterial Cells ◽  
Brownian Ratchet ◽  
Ratchet Mechanism ◽  
Directional Movement

AbstractThe FtsZ protein is a central component of the bacterial cell division machinery. It polymerizes at mid-cell and recruits more than 30 proteins to assemble into a macromolecular complex to direct cell wall constriction. FtsZ polymers exhibit treadmilling dynamics, driving the processive movement of enzymes that synthesize septal peptidoglycan (sPG). Here, we combine theoretical modelling with single-molecule imaging of live bacterial cells to show that FtsZ’s treadmilling drives the directional movement of sPG enzymes via a Brownian ratchet mechanism. The processivity of the directional movement depends on the binding potential between FtsZ and the sPG enzyme, and on a balance between the enzyme’s diffusion and FtsZ’s treadmilling speed. We propose that this interplay may provide a mechanism to control the spatiotemporal distribution of active sPG enzymes, explaining the distinct roles of FtsZ treadmilling in modulating cell wall constriction rate observed in different bacteria.

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