Wyniki wyszukiwania - BazTech

1

Soft contact manipulation of a rigid objectusing multibond graph

Rathee Raul, Narwal Anil Kumar, Vaz Anand

Computer Assisted Methods in Engineering and Science

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2021

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Vol. 28, no. 4

321--349

EN

Dexterous manipulation of a rigid object using artificial soft fingers is not easy to achieve.Instantaneous contact areas and the distribution of contact forces at the interfaces changedynamically during the soft contact manipulation of the object. A bond graph modelfor dynamics of the soft contact manipulation of a rigid object using two soft pads is developed. A cylindrical disc is used as the rigid object to be manipulated between two softsilicon rubber pads considered in place of soft fingertips, one above and the other below.The disc is grasped and rolled between the two pads so its center follows a desired horizontal displacement trajectory. A closed-loop feedback control system generates the requiredforce to grasp and control the instantaneous position of the disc’s center. The model determines the instantaneous contact forces required for the desired manipulation. Simulationresults validate the model.

2

Adaptation of the machine to the new geological conditions – excavation unit redesign and optimization

Andruszko Jakub, Moczko Przemyslaw, Pietrusiak Damian

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 3

art. no. e137122

EN

The paper presents and sums up the research and technical aspects of the modernization of the cutting tool of the dredger. Improper adjustment of the cutting elements not adjusted to the characteristics of excavated material is not an uncommon situation, causing versatile geological conditions. Relocation of the machines from one pit to another may result in the significant influence on the excavation process (wear, output, etc.). Common practice is the field try and error approach to obtain desired machine performance. In the paper authors present the approach with aid of cutting-edge technologies. Coupled DEM and kinematic simulations supported by the reverse engineering technologies of laser scanning were the fundamental drivers for final adjustments of the cutting tool at its present operational conditions.

3

Free vibrations and stability of discrete systems subjected to the specific load

Tomski L., Szmidla J.

Journal of Theoretical and Applied Mechanics

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2007

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Vol. 45 nr 4

873-892

EN

In this paper, we present discrete systems subjected to a generalised specific load by a force directed towards to positive pole and a folIower force directed towards the positive pole. The critical load and the course of the naturaI frequency in relation to the external load are determined. Adequate relationships describing stability of the considered columns are obtained taking into account potential energy of the systems (energetic method) or total mechanical energy (vibration method). Geometrical parameters of heads realising the lo ad and rigidity of rotational springs modelIing the finite stiffness of structural constraints of the system are taken into account.

PL

W pracy prezentuje się układy dyskretne poddane działaniu obciążenia swoistego uogólnionego z siłą skierowaną do bieguna dodatniego oraz siłą śledzącą skierowaną do bieguna dodatniego. Dla zaprezentowanych struktur analizuje się wpływ parametrów geometrycznych głowic realizujących obciążenie oraz sztywności sprężyn rotacyjnych modelujących skończoną sztywność węzłów konstrukcyjnych układu na wartość obciążenia krytycznego oraz na przebieg zmian częstości drgań własnych w funkcji obciążenia zewnętrznego. Odpowiednie związki opisujące stateczność rozważanych kolumn uzyskuje się biorąc pod uwagę energię potencjalną układów (metoda energetyczna) lub całkowitą energię mechaniczną (metoda drgań).

4

The Equations of Impulse and Momentum for the Rigid Body

Jankowski J.

Vibrations in Physical Systems

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2004

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Vol. 21

171--174

5

On the foundations of ordinary and generalized rigid body dynamics and the principle of objectivity

Chevallier D. P.

Archives of Mechanics

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2004

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Vol. 56, nr 4

313-353

EN

This article presents the foundations of Newton-Euler rigid body dynamics and its generalized forms in the light of the objectivity principle. We prove that most of the features of dynamics may be directly deduced from this principle and from properties of the group defining the geometry. In particular, these deductions seem to close the conjectures about the relevance of the objectivity principle to dynamics.