Mobile Robot Utilizing Arm Rotations – Performance of Mobile Robot Under a Gravity Environment –

2020 ◽  
Vol 32 (1) ◽  
pp. 254-263
Author(s):  
Ryota Hayashi ◽  
Yasuyuki Setoyama ◽  
Tetsuya Kinugasa ◽  
Koji Yoshida ◽  
◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Mobile Robot ◽  
Numerical Simulations ◽  
The Body ◽  
Planar Space

In this research, we have considered a mobile robot that can start to move by utilizing rotations of the two arms. This robot consists of two rotating arms and a body. Additionally, it has a device that can fix the body to a platform constructed on a certain wall or floor. In our previous study, we investigated the performance of a robot that could move in a planar space without friction or gravity through several numerical simulations. In this study, we investigate the performance of the mobile robot under a gravity environment. While the body is fixed to a starting platform, the mobile robot can store kinetic energy by rotating its arms. When the body is released from the starting platform, the mobile robot hops to the subsequent platform. We consider a scheme to control the hopping direction of the mobile robot and a scheme to reduce the collision impact against the subsequent platform. Thereafter, we verify the feasibility of the proposed schemes through numerical simulations.

Moving Cage: Vibration, Sonification and the Quanta of Time

2021 ◽  
Vol 46 (2) ◽  
pp. 169-183
Author(s):  
MARCUS CHENG CHYE TAN
Keyword(s):  
Kinetic Energy ◽  
The Body ◽  
Dance Movements ◽  
Politics Of The Body

Dear John is an experimental choreomusical work that reinterprets Cage's works while advancing his ideas of sound as sonic events and embodied choreography. In this episodic work, improvised movement unfolds to a soundscape of defamiliarized instruments, sound devices and sonicities of macro- and micro-movements. The correspondence and (in)congruence between dance movements and music's kinetic energy become the means to examine a politics of the body and sound, of music on movement. Additionally, in this ‘auditory architecture’ the quanta of time, its relations and (lack of) unity are exposed. This article then examines the intersubjective interplay of movement and music, body and sonicity; it considers the resonance of the performing body as intermaterial vibration and how this invites a sonic politics of relational possibility. The article will then also investigate the ways in which the interaction of motion and music, movement and stillness engenders experiences of time's indeterminacy and elasticity.

Direct Kinematic Analysis of a Hexapod Spider-Like Mobile Robot

2011 ◽  
Vol 403-408 ◽  
pp. 5053-5060 ◽  
Author(s):  
Mostafa Ghayour ◽  
Amir Zareei
Keyword(s):  
Angular Velocity ◽  
Mobile Robot ◽  
Time Variation ◽  
Kinematic Analysis ◽  
The Body ◽  
Specific Time ◽  
Centre Of Gravity ◽  
Joint Variable ◽  
Direct Kinematics ◽  
Robot Platform

In this paper, an appropriate mechanism for a hexapod spider-like mobile robot is introduced. Then regarding the motion of this kind of robot which is inspired from insects, direct kinematics of position and velocity of the centre of gravity (C.G.) of the body and noncontact legs are analysed. By planning and supposing a specific time variation for each joint variable, location and velocity of the C.G. of the robot platform and angular velocity of the body are obtained and the results are shown and analysed.

Heat Transfer Increase by Flow Structures Modifications

2005 ◽  
Author(s):  
Charles-Andre´ Lemarie´ ◽  
Nachida Bourabaa ◽  
Franc¸ois Monnoyer ◽  
Tewfik Benazzouz
Keyword(s):  
Heat Transfer ◽  
Simple Model ◽  
Kinetic Energy ◽  
Numerical Simulations ◽  
Experimental Tests ◽  
Flow Structures ◽  
Driven Cavity ◽  
Simple Geometry ◽  
Through Flow ◽  
Do So

This paper makes use of a new methodology for heat transfer increase through flow structures modifications. Intended to help railway designers in handling cooling issues, it is applied to improve the roof-mounted equipment design of a modern railway coach, namely the CORADIA TER 2N NG produced by the ALSTOM Transport company. The brake resistor, a key equipment in charge of dissipating the train kinetic energy as heat into the surrounding air during braking phases, has been particularly considered. To do so, a simple model including a heated obstacle inside a three-sided lead-driven cavity is used, and simple geometry variations are suggested. Their impact on heat transfer is then estimated through numerical simulations while experimental tests validate the results obtained.

Effects of terrain irregularities on wheeled mobile robot

Robotica ◽  
2003 ◽  
Vol 21 (2) ◽  
pp. 143-152 ◽  
Author(s):  
Maria Prado ◽  
Antonio Simón ◽  
Ana Pérez ◽  
Francisco Ezquerro
Keyword(s):  
Mobile Robot ◽  
Wheeled Mobile Robot ◽  
The Body ◽  
Uneven Terrain

The influence of ground irregularities on the behavior of a wheeled mobile robot (WMR) navigating on uneven surfaces is addressed. The paper studies the vibratory movements induced on the body of the WMR, in order to analyze its ability for carrying out on-board tasks, and on the accuracy of the data collected by its external sensorial systems. The adhesion capability of the wheels of the WMR on this uneven terrain is also studied, since it conditions the braking, traction and steering performance. The method is applied to the WMR RAM.

Optimal Self-Propulsion of a Deformable Prolate Spheroid

1983 ◽  
Vol 27 (02) ◽  
pp. 121-130
Author(s):  
T. Miloh
Keyword(s):  
Kinetic Energy ◽  
Surface Deformation ◽  
Deformable Body ◽  
Large Degree ◽  
Prolate Spheroid ◽  
The Body ◽  
Deformation Pattern ◽  
Inviscid Fluid ◽  
Periodic Surface ◽  
Deformation Velocity

The problem of self-propulsion of an elongated deformable body moving in an infinite medium of inviscid fluid is considered in some detail. A prolate spheroid is chosen as a model shape, and a particular deformation pattern which maximizes the Froude efficiency is sought. The Froude efficiency in this context is defined by the ratio of the kinetic energy of the body to the total kinetic energy of the system comprising the body and the fluid. It is demonstrated that a body can propel itself from rest in a persistent manner even for a periodic surface deformation with zero mean which preserves both the volume and the location of its centroid. Under these constraints the induced forward velocity of the body is of 0(ε2) where ε is the amplitude of the deformation velocity. It is also demonstrated that for a persistent self-propulsion to exist the body should develop a large degree of skewness, resulting from the interaction between the two deformation components—one with fore-and-aft symmetry and one without. It is also essential that the symmetric and asymmetric deformation components should be out of phase.

scholarly journals Partitioning Waves and Eddies in Stably Stratified Turbulence

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 420 ◽  
Author(s):  
Henri Lam ◽  
Alexandre Delache ◽  
Fabien S Godeferd
Keyword(s):  
Dispersion Relation ◽  
Kinetic Energy ◽  
Laminar Flow ◽  
Turbulent Flow ◽  
Numerical Simulations ◽  
Direct Numerical Simulations ◽  
Energy Concentration ◽  
Kinetic Energy Density ◽  
Stratified Turbulence ◽  
The Waves

We consider the separation of motion related to internal gravity waves and eddy dynamics in stably stratified flows obtained by direct numerical simulations. The waves’ dispersion relation links their angle of propagation to the vertical θ , to their frequency ω , so that two methods are used for characterizing wave-related motion: (a) the concentration of kinetic energy density in the ( θ , ω ) map along the dispersion relation curve; and (b) a direct computation of two-point two-time velocity correlations via a four-dimensional Fourier transform, permitting to extract wave-related space-time coherence. The second method is more computationally demanding than the first. In canonical flows with linear kinematics produced by space-localized harmonic forcing, we observe the pattern of the waves in physical space and the corresponding concentration curve of energy in the ( θ , ω ) plane. We show from a simple laminar flow that the curve characterizing the presence of waves is distorted differently in the presence of a background convective mean velocity, either uniform or varying in space, and also when the forcing source is moving. By generalizing the observation from laminar flow to turbulent flow, this permits categorizing the energy concentration pattern of the waves in complex flows, thus enabling the identification of wave-related motion in a general turbulent flow with stable stratification. The advanced method (b) is finally used to compute the wave-eddy partition in the velocity–buoyancy fields of direct numerical simulations of stably stratified turbulence. In particular, we use this splitting in statistics as varied as horizontal and vertical kinetic energy, as well as two-point velocity and buoyancy spectra.

K–ϵ model for rotating homogeneous decaying turbulence

2016 ◽  
Vol 94 (11) ◽  
pp. 1200-1204 ◽  
Author(s):  
Hamed Marzougui
Keyword(s):  
Kinetic Energy ◽  
Numerical Simulations ◽  
Decay Rate ◽  
Rate Equation ◽  
Rotation Rate ◽  
Dissipation Rate ◽  
Direct Numerical Simulations ◽  
Uniform Rotation ◽  
Axis Of Rotation ◽  
Decaying Turbulence

In the present work, we propose a modification to the standard K–ϵ model for simulating homogeneous decaying turbulence subjected to uniform rotation. In this modification, the dissipation rate equation is formulated in terms of the rotation rate Ω, the integral length scales along the axis of rotation [Formula: see text], and its isotropic value [Formula: see text]. The comparison of our results with the corresponding direct numerical simulations proves that the new model reproduces in an excellent way the decay rate of the turbulent kinetic energy.

Numerical Simulations of the Kinetic Energy Transfer in the Bath of a BOF Converter

2015 ◽  
Vol 47 (1) ◽  
pp. 434-445 ◽  
Author(s):  
Xiaobin Zhou ◽  
Mikael Ersson ◽  
Liangcai Zhong ◽  
Pär Jönsson
Keyword(s):  
Energy Transfer ◽  
Kinetic Energy ◽  
Numerical Simulations ◽  
Kinetic Energy Transfer

Stability and dynamics of the laminar wake past a slender blunt-based axisymmetric body

2011 ◽  
Vol 676 ◽  
pp. 110-144 ◽  
Author(s):  
P. BOHORQUEZ ◽  
E. SANMIGUEL-ROJAS ◽  
A. SEVILLA ◽  
J. I. JIMÉNEZ-GONZÁLEZ ◽  
C. MARTÍNEZ-BAZÁN
Keyword(s):  
Stability Analysis ◽  
Numerical Simulations ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Velocity Ratio ◽  
Reynolds Numbers ◽  
Base Flow ◽  
Direct Numerical Simulations ◽  
The Body ◽  
Stream Velocity

We investigate the stability properties and flow regimes of laminar wakes behind slender cylindrical bodies, of diameter D and length L, with a blunt trailing edge at zero angle of attack, combining experiments, direct numerical simulations and local/global linear stability analyses. It has been found that the flow field is steady and axisymmetric for Reynolds numbers below a critical value, Recs (L/D), which depends on the length-to-diameter ratio of the body, L/D. However, in the range of Reynolds numbers Recs(L/D) < Re < Reco(L/D), although the flow is still steady, it is no longer axisymmetric but exhibits planar symmetry. Finally, for Re > Reco, the flow becomes unsteady due to a second oscillatory bifurcation which preserves the reflectional symmetry. In addition, as the Reynolds number increases, we report a new flow regime, characterized by the presence of a secondary, low frequency oscillation while keeping the reflectional symmetry. The results reported indicate that a global linear stability analysis is adequate to predict the first bifurcation, thereby providing values of Recs nearly identical to those given by the corresponding numerical simulations. On the other hand, experiments and direct numerical simulations give similar values of Reco for the second, oscillatory bifurcation, which are however overestimated by the linear stability analysis due to the use of an axisymmetric base flow. It is also shown that both bifurcations can be stabilized by injecting a certain amount of fluid through the base of the body, quantified here as the bleed-to-free-stream velocity ratio, Cb = Wb/W∞.

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