Control of following Force in Gimbal Suspension by Programmed Transfer of Vehicle in the Class of Spiral-Screw Trajectories

2020 ◽  
Vol 8 (6) ◽  
pp. 01-15
Author(s):  
Kravets V.V ◽  
Kravets Vl.V ◽  
Artemchuk V.V.
Keyword(s):  
Mathematical Models ◽  
Reference System ◽  
Driving Force ◽  
Reference Systems ◽  
Structural Scheme ◽  
Inertial Space ◽  
Transport Vehicle ◽  
Terrestrial Reference System ◽  
Force Components ◽  
Speed Mode

The programmed transfer of the transport vehicle in space is carried out in the class of helical trajectories, using forcing (throttling) and deviation of the following driving force in the gimbal. The paper introduces the mathematical models of the transport vehicle kinetics in space in the terrestrial reference system and in the basis of the natural trihedral of the trajectory, using the quaternion form. The kinematics of the transport vehicle in the fixed and mobile reference systems, as well as the orientation of the natural trihedral in the inertial space, are represented by the hodograph of the program helix trajectory in vector and quaternion forms. The components of the controlling driving force in the basis of the natural trihedral are determined by the kinetostatics equations of the programmed transfer of the transport vehicle along a helical trajectory in the required speed mode. The authors proposed a structural scheme of the gimbal suspension, providing the required driving force components. The authors considered two possible sequences of rotations of the moving gimbal rings and demonstrated their equivalence. Laconic formulas are established for the control angles of rotation of the moving gimbal rings.

scholarly journals A Terrestrial Reference System Consistent with WGRS

1991 ◽  
Vol 127 ◽  
pp. 211-214 ◽  
Author(s):  
C. Boucher ◽  
Z. Altamimi
Keyword(s):  
Reference System ◽  
Terrestrial Reference Frame ◽  
Reference Systems ◽  
International Earth Rotation Service ◽  
Earth Orientation Parameters ◽  
Terrestrial Reference System ◽  
Definition Of ◽  
Orientation Parameters ◽  
Evolution With Time

AbstractThe IAU and IUGG has jointly established in 1988 an International Earth Rotation Service (IERS) which is in charge of the realization of conventional celestial and terrestrial reference systems, together with the determination of earth orientation parameters which connect them.The theoretical definition of the terrestrial reference system which is realized by IERS through a conventional terrestrial reference frame formed by SLR, LLR, VLBI and GPS stations is presented. In particular its origin, scale, orientation and evolution with time are reviewed, taking into account relativistic and deformation effects.

scholarly journals Use of Gravity Measurements in Defining and Realizing Reference Systems for Geodynamics

1980 ◽  
Vol 56 ◽  
pp. 217-223
Author(s):  
J. D. Boulanger ◽  
N. N. Pariisky ◽  
L. P. Pellinen
Keyword(s):  
Reference System ◽  
Reference Ellipsoid ◽  
Reference Points ◽  
Sufficient Information ◽  
Reference Systems ◽  
The Earth ◽  
Gravity Measurements ◽  
Terrestrial Reference System

AbstractSingle measurements of gravity cannot give sufficient information about the position of measuring points with respect to some terrestrial reference system. Only a set of gravimetric stations all over the Earth combined with a determination of their coordinates allows one to determine (from the solution of Molodensky’s problem) the heights of these stations with respect to a level ellipsoid with center at the geocenter. Given in addition their heights above some reference ellipsoid, whose position in the Earth’s body is fixed through a set of reference points on its surface, the position of the geocenter in the same reference system may be obtained.

scholarly journals Definition and realization of the celestial intermediate reference system

2007 ◽  
Vol 3 (S248) ◽  
pp. 367-373 ◽  
Author(s):  
N. Capitaine
Keyword(s):  
Reference System ◽  
Reference Systems ◽  
The Earth ◽  
Fundamental Astronomy ◽  
International Terrestrial Reference System ◽  
Terrestrial Reference System ◽  
Rotation Of The Earth ◽  
Definition Of ◽  
Sidereal Rotation ◽  
Celestial Reference System

AbstractThe transformation between the International Terrestrial Reference System (ITRS) and the Geocentric Celestial Reference system (GCRS) is an essential part of the models to be used when dealing with Earth's rotation or when computing directions of celestial objects in various systems. The 2000 and 2006 IAU resolutions on reference systems have modified the way the Earth orientation is expressed and adopted high accuracy models for expressing the relevant quantities for the transformation from terrestrial to celestial systems. First, the IAU 2000 Resolutions have refined the definition of the astronomical reference systems and transformations between them and adopted the IAU 2000 precession-nutation. Then, the IAU 2006 Resolutions have adopted a new precession model that is consistent with dynamical theories and have addressed definition, terminology or orientation issues relative to reference systems and time scales that needed to be specified after the adoption of the IAU 2000 resolutions. These in particular provide a refined definition of the pole (the Celestial intermediate pole, CIP) and the origin (the Celestial intermediate origin, CIO) on the CIP equator as well as a rigorous definition of sidereal rotation of the Earth. These also allow an accurate realization of the celestial intermediate system linked to the CIP and the CIO that replaces the classical celestial system based on the true equator and equinox of date. This talk explains the changes resulting from the joint IAU 2000/2006 resolutions and reviews the consequences on the concepts, nomenclature, models and conventions in fundamental astronomy that are suitable for modern and future realizations of reference systems. Realization of the celestial intermediate reference system ensuring a micro-arc-second accuracy is detailed.

scholarly journals Redefining of “EPSG” and “PROJ” for current State Coordinate Reference System of the Republic of North Macedonia

2021 ◽  
Vol 4 ◽  
pp. 1-8
Author(s):  
Bashkim Idrizi
Keyword(s):  
Real Estate ◽  
Spatial Data ◽  
Reference System ◽  
Coordinate Transformations ◽  
Reference Systems ◽  
Spatial Reference ◽  
Current State ◽  
Entire Country ◽  
The Republic ◽  
The Military

Abstract. The state Coordinate Reference System (CRS) of the Republic of North Macedonia (RNM) has been established a century ago, by the Military Geographic Institute of the Yugoslavia Kingdom. It is in official usage entire period up to day. In international public EPSG registry of geodetic datums, spatial reference systems, Earth ellipsoids, coordinate transformations and related units of measurement, CRS for RNM is recognizable within 3 EPSG codes 6204, 6316 and 8679.First code EPSG 6204 represents current state CRS for the entire country area, based on current law, however unfortunately this CRS is official by the law but it is not used for developing the official spatial data published in geoportals of Agency for Real Estate Cadastre (AREC) and NSDI geoportal of RNM. The second code EPSG 6316 is defined to be used for 6 countries of former Yugoslavia that covers area between 19.5°E up to 22.5°E longitude, which does not correspond with the practical and official usage of CRS for working with spatial data in RNM and CRS law definition in RNM. Third code EPSG 8679 has never been used in RNM, which covers eastern part of RNM and Serbia beginning from 22.5°E.Beside of problems with EPSG codes, default transformation parameters of EPSG 6316 have low accuracy and can not be used for data overlapping with open layers. Therefore, redefined new EPSG codes for state CRS of RNM are proposed in this paper.

On the design and interpretation of experiments to elucidate albumin-dependent hepatic uptake

1992 ◽  
Vol 262 (6) ◽  
pp. G1127-G1137 ◽  
Author(s):  
Z. S. Cai ◽  
F. J. Burczynski ◽  
B. A. Luxon ◽  
E. L. Forker
Keyword(s):  
Cell Surface ◽  
Mathematical Models ◽  
Driving Force ◽  
Free Ligand ◽  
Hepatic Uptake ◽  
Organic Anions ◽  
Putative Mechanism

The liver's apparently anomalous extraction of organic anions tightly bound to albumin continues to provoke controversy and confusion. Decisive experiments have proved difficult to design, and mathematical models have usually been constructed to defend one or another putative mechanism to the exclusion of others. To stimulate more decisive experiments and as an aid to interpreting those already reported, we discuss a general formulation of the problem that predicts the clearance pattern to be expected when facilitated dissociation and codiffusion are joint determinants of the uptake flux. The results provide an approach to modeling the various mechanisms by which the concentration of bound ligand at the cell surface could be a driving force for uptake. Further we present new calculations to clarify the interpretation of net ligand clearance when the removal of free ligand is the result of bidirectional fluxes into and out of an unstirred sink. Applied to a previously published comparison of the uptake performances of hepatocytes and polyethylene, the new calculations support the inference that facilitated dissociation of albumin-palmitate complexes occurs at or near the hepatocyte surface.

scholarly journals Validation methods for global and local positioning-based athlete monitoring systems in team sports: a scoping review

2020 ◽  
Vol 6 (1) ◽  
pp. e000794
Author(s):  
Live Steinnes Luteberget ◽  
Matthias Gilgien
Keyword(s):  
Scoping Review ◽  
Validation Studies ◽  
Reference System ◽  
Team Sports ◽  
Infrared Camera ◽  
Global Navigation Satellite Systems ◽  
Reference Systems ◽  
Eligibility Criteria ◽  
Positioning Systems ◽  
True Path

Background/ObjectiveGlobal navigation satellite systems (GNSS) and local positioning systems (LPS) are to date common tools to measure external training load in athletes. The aim of this scoping review was to map out and critically appraise the methods used to validate different GNSS and LPS used in team sports.MethodA total of 48 studies met the eligibility criteria and were included in the review. The reference systems applied in the validations, and the parameters investigated were extracted from the studies.ResultsThe results show a substantial range of reference systems used to validate GNSS and LPS and a substantial number of investigated parameters. The majority of the validation studies have employed relatively simple field-based research designs, with use of measure tape/known distance as reference measure for distance. Timing gates and radar guns were frequently used as reference system for average and peak speed. Fewer studies have used reference system that allow for validation of instantaneous dynamic position, such as infrared camera-based motion capture systems.ConclusionsBecause most validation studies use simple and cost-effective reference systems which do not allow to quantify the exact path athletes travel and hence misjudge the true path length and speed, caution should be taken when interpreting the results of validation studies, especially when comparing results between studies. Studies validating instantaneous dynamic position-based measures is warranted, since they may have a wider application and enable comparisons both between studies and over time.

scholarly journals The mathematical models for cutting force calculation during structural and corrosion-resistant steels` parts processing

2019 ◽  
Vol 298 ◽  
pp. 00099
Author(s):  
Alexey A. Zhdanov ◽  
Oleg A. Kursin ◽  
Pham Xuan Bach
Keyword(s):  
Mathematical Models ◽  
Cutting Force ◽  
Experimental Studies ◽  
Additional Parameter ◽  
Corrosion Resistant ◽  
Cutting Force Components ◽  
Force Components ◽  
Quantitative Indicators ◽  
Force Calculation ◽  
Thermo Physical Properties

The paper shows that conventional mathematical models for calculating the cutting force components during the turning process, represented in reference guides on engineering, give drastic errors reaching 100 percent or more for various tool-workpiece couples. These errors interfere with applying reference values of the cutting force for any further calculations, equipment selection, workpiece positioning scheme, workpiece deformation value due to the elastic of the technological system elements during processing and etc., because of the insufficient reliability of the results of such calculations. The paper proposes mathematical models obtained as a result of experimental studies, which allow for increasing the accuracy of the calculation of the components of the cutting force by introducing an additional parameter – i.e., the value of thermo EMF of the test running into the calculation formulas. This approach enables to reduce the error in the calculation of the components of the cutting force up to ± 15%. In addition, the need for the development of specific mathematical models for various groups of materials machined is shown, which is due to the peculiarities of contact processes in the machining of various groups of steels, as well as to qualitative and quantitative indicators of the thermo-physical properties of the materials of tool-workpiece contact couples.

Breaking the clause chains

2015 ◽  
Vol 39 (3) ◽  
pp. 664-697 ◽  
Author(s):  
Hannah Sarvasy
Keyword(s):  
Reference System ◽  
Reference Systems

Clause chaining in Papuan languages is a keystone of the literature on switch-reference (Haiman & Munro 1983, Stirling 1993). Canonically, a clause chain is considered to comprise one or more ‘medial’ clauses, followed by a single ‘final’ clause. In Nungon and other Papuan languages, canonical clause chains coexist with non-canonical clause chains, which either feature medial clauses postposed after the final clause, or lack a final clause altogether. I examine the functions of non-canonical medial clauses in Nungon and other Papuan languages in a first attempt at a typology of these uses, given scanty data. Non-canonical medial clauses are argued to represent canny use of the features of clause chains and switch-reference systems to convey meaning efficiently. The exposition also solves an outstanding puzzle of the Amele switch-reference system (Roberts 1988, Stirling 1993).

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