Flight Control of a Twin-Rotor Type Model Helicopter Based on First-Order Approximate Linearization

2014 ◽  
Vol 134 (9) ◽  
pp. 1269-1270 ◽  
Author(s):  
Hiroki Noma ◽  
Shun Tanabe ◽  
Takao Sato ◽  
Nozomu Araki ◽  
Yasuo Konishi
Keyword(s):  
Flight Control ◽  
Type Model ◽  
First Order ◽  
Model Helicopter ◽  
Approximate Linearization ◽  
Twin Rotor ◽  
Rotor Type

scholarly journals MPAS-Albany Land Ice (MALI): A variable resolution ice sheet model for Earth system modeling using Voronoi grids

2018 ◽  
Author(s):  
Matthew J. Hoffman ◽  
Mauro Perego ◽  
Stephen F. Price ◽  
William H. Lipscomb ◽  
Douglas Jacobsen ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Earth System Model ◽  
Coupled Systems ◽  
System Model ◽  
Type Model ◽  
Earth System ◽  
Ice Dynamics ◽  
Variable Resolution ◽  
Horizontal Advection ◽  
First Order

Abstract. We introduce MPAS-Albany Land Ice (MALI), a new, variable resolution land ice model that uses unstructured Voronoi grids on a plane or sphere. MALI is built using the Model for Prediction Across Scales (MPAS) framework for developing variable resolution Earth System Model components and the Albany multi-physics code base for solution of coupled systems of partial-differential equations, which itself makes use of Trilinos solver libraries. MALI includes a three-dimensional, first-order momentum balance solver ("Blatter-Pattyn") by linking to the Albany-LI ice sheet velocity solver, as well as an explicit shallow ice velocity solver. Evolution of ice geometry and tracers is handled through an explicit first-order horizontal advection scheme with vertical remapping. Evolution of ice temperature is treated using operator splitting of vertical diffusion and horizontal advection and can be configured to use either a temperature or enthalpy formulation. MALI includes a mass-conserving subglacial hydrology model that supports distributed and/or channelized drainage and can optionally be coupled to ice dynamics. Options for calving include "eigencalving", which assumes calving rate is proportional to extensional strain rates. MALI is evaluated against commonly used exact solutions and community benchmark experiments and shows the expected accuracy. We report first results for the MISMIP3d benchmark experiments for a Blatter-Pattyn type model and show that results fall in-between those of models using Stokes flow and L1L2 approximations. We use the model to simulate a semi-realistic Antarctic Ice Sheet problem for 1100 years at 20 km resolution. MALI is the glacier component of the Energy Exascale Earth System Model (E3SM) version 1, and we describe current and planned coupling to other components.

Programmable Flight Control Type Model Airplane for Survey

2005 ◽  
Author(s):  
Hideaki Kakojima ◽  
Kiyoshi Akinaga
Keyword(s):  
Flight Control ◽  
Type Model

Polycrystalline plasticity and the evolution of crystallographic texture in FCC metals

1992 ◽  
Vol 341 (1662) ◽  
pp. 443-477 ◽  
Keyword(s):  
Finite Element ◽  
Crystallographic Texture ◽  
Single Phase ◽  
Type Model ◽  
Strain Response ◽  
Stress Strain ◽  
Fcc Metals ◽  
First Order ◽  
Finite Element Calculations ◽  
Simple Compression

A Taylor-type model for large deformation polycrystalline plasticity is formulated and evaluated by comparing the predictions for the evolution of crystallographic texture and the stress-strain response in simple compression and tension, plane strain compression, and simple shear of initially ‘isotropic’ OFHC copper against ( a ) corresponding experiments, and ( b ) finite element simulations of these experiments using a multitude of single crystals with accounting for the satisfaction of both compatibility and equilibrium. Our experiments and calculations show that the Taylor-type model is in reasonable first-order agreement with the experiments for the evolution of texture and the overall stress-strain response of single-phase copper. The results of the finite element calculations are in much better agreement with experiments, but at a substantially higher computational expense.

scholarly journals Spreading out Muscle Mass within a Hill-Type Model: A Computer Simulation Study

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Michael Günther ◽  
Oliver Röhrle ◽  
Daniel F. B. Haeufle ◽  
Syn Schmitt
Keyword(s):  
Design Parameters ◽  
Type Model ◽  
Internal Mass ◽  
Response Scale ◽  
First Order ◽  
Contraction Velocity ◽  
Hyperbolic Relation ◽  
Small Muscle ◽  
Internal Inertia ◽  
Contraction Dynamics

It is state of the art that muscle contraction dynamics is adequately described by a hyperbolic relation between muscle force and contraction velocity (Hill relation), thereby neglecting muscle internal mass inertia (first-order dynamics). Accordingly, the vast majority of modelling approaches also neglect muscle internal inertia. Assuming that such first-order contraction dynamics yet interacts with muscle internal mass distribution, this study investigates two questions: (i) what is the time scale on which the muscle responds to a force step? (ii) How does this response scale with muscle design parameters? Thereto, we simulated accelerated contractions of alternating sequences of Hill-type contractile elements and point masses. We found that in a typical small muscle the force levels off after about 0.2 ms, contraction velocity after about 0.5 ms. In an upscaled version representing bigger mammals' muscles, the force levels off after about 20 ms, and the theoretically expected maximum contraction velocity is not reached. We conclude (i) that it may be indispensable to introduce second-order contributions into muscle models to understand high-frequency muscle responses, particularly in bigger muscles. Additionally, (ii) constructing more elaborate measuring devices seems to be worthwhile to distinguish viscoelastic and inertia properties in rapid contractile responses of muscles.

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