Improved torque roll axis decoupling axiom for a powertrain mounting system in the presence of a compliant base

2012 ◽  
Vol 331 (7) ◽  
pp. 1498-1518 ◽  
Author(s):  
Jin-Fang Hu ◽  
Rajendra Singh
Keyword(s):  
Roll Axis

Roll axis tracking improvement resulting from peripheral vision motion cues

1976 ◽  
Author(s):  
Thomas E. Moriarty ◽  
Andrew M. Junker ◽  
Don R. Price
Keyword(s):  
Peripheral Vision ◽  
Motion Cues ◽  
Roll Axis

Spatio-temporal regimes in Rayleigh–Bénard convection in a small rectangular cell

1989 ◽  
Vol 209 ◽  
pp. 309-334 ◽  
Author(s):  
M. A. Rubio ◽  
P. Bigazzi ◽  
L. Albavetti ◽  
S. Ciliberto
Keyword(s):  
Travelling Waves ◽  
Rectangular Cell ◽  
Complex Behaviour ◽  
Temporal Behaviour ◽  
Bénard Convection ◽  
Benard Convection ◽  
Spatio Temporal ◽  
Roll Axis ◽  
Rayleigh Benard Convection ◽  
Rayleigh Benard

By means of an original optical technique we have studied the spatio-temporal behaviour in a Rayleigh–Bénard convection experiment of small rectangular geometry. The experimental technique allows complete reconstruction of the temperature field integrated along the roll axis. Two main spatiotemporal regimes have been found, corresponding to localized oscillations and travelling waves respectively. Several parameters are proposed for the quantitative characterization of this complex behaviour.

The Transverse Plane Motions of Ships

1991 ◽  
Vol 28 (02) ◽  
pp. 55-72
Author(s):  
Bruce L. Hutchison
Keyword(s):  
Transverse Plane ◽  
Irregular Waves ◽  
Hydrodynamic Coefficients ◽  
Important Process ◽  
Regular Waves ◽  
Hull Form ◽  
Fishing Vessels ◽  
Transverse Stability ◽  
Roll Axis ◽  
The One

A detailed exposition of the kinematics of the transverse plane motions of ships is provided, with particular attention to the important process of total transverse acceleration in vessel coordinates. The loci of sway, sway velocity and sway acceleration are shown to follow hyperbolic distributions with respect to elevation in both regular and irregular waves. In regular waves the transverse acceleration in earth-fixed and vessel-fixed coordinates are shown to be congruent with a vertical shift in elevation of g/ω2 = λ/(2π). Expressions are given for the elevations minimizing transverse plane processes in regular and irregular waves. In long waves the elevation minimizing total transverse acceleration in vessel coordinates is shown to be g/ωn2 = g[Tn/ /(2π)]2 below the waterline. This is the roll center, which should be used in the traditional analysis of foundation loads. Its location, far below the keel for most vessels, is surprising. The elevation (OP) of the roll axis, which must be used when solving the one-degree-of-freedom equation for roll, is given and is shown to require hydrodynamic coefficients for sway as well as roll. In general, OP does not correspond to an elevation that minimizes any of the transverse plane processes. The effect of hull form, transverse stability and natural roll period on transverse plane motions are examined in an attempt to resolve the dichotomy of views between those who favor ships with low GMT and long natural roll periods and those who favor high GMT with short natural roll periods. It is demonstrated that large values of the beam-to-draft ratio (6/7) with low natural roll periods are advantageous at modest elevations above the waterline. This explains the favorable offshore experience in vessels meeting this description, such as tugs, supply vessels and fishing vessels. At higher elevations long natural periods are shown to present a clear advantage, which supports the preference for low GMT for large passenger vessels, containerships and ships with deck-loads of logs. The trends identified would seem to support the conjecture that, with regard to natural roll period, there is a "forbidden middle" that should be avoided in design.

Evaluation of the Torsional VOR in Weightlessness

1993 ◽  
Vol 3 (3) ◽  
pp. 207-218
Author(s):  
Andrew H. Clarke ◽  
Winfried Teiwes ◽  
Hans Scherer
Keyword(s):  
Head Movement ◽  
Angular Rate ◽  
Inertial Force ◽  
Semicircular Canals ◽  
Head Rotation ◽  
Video Data ◽  
Microgravity Conditions ◽  
Oculomotor Response ◽  
Roll Axis ◽  
Integrative Processing

The experimental concept and findings from a recent manned orbital spaceflight are described. Together with ongoing terrestrial and parabolic studies, the present experiment is intended to further our knowledge of the sensory integrative processing of information from the semicircular canals and the otolithic receptors, and to quantify the presumed otolithic adaptation to altered gravito-inertial force environments in a more reliable manner than to date. The experiment included measurement of the basic vestibulo-oculomotor response during active head rotation about each of the three orthogonal axes. Priority was given to the recording of ocular torsion, as elicited by head oscillation about the roll axis, and thus due to the concomitant stimulation of the semicircular canals and otolith receptors. Videooculography was employed for the measurement of eye movements; head movement was measured by three orthogonally arranged angular rate sensors and a triaxial linear accelerometer device. All signals were recorded synchronously on a video/data recorder. Preliminary results indicate alterations in the torsional VOR under zero-g conditions, suggesting an adaptive modification of the torsional VOR gain over the course of the 6-day orbital flight. In addition, the inflight test findings yielded discrepancies between intended and performed head movement indicating impairment in sensorimotor coordination under prolonged microgravity conditions.

Roll-Axis Hydrofluidic Stability Augmentation System Development

1975 ◽  
Author(s):  
Darroll Bengtson ◽  
Thomas Dickovich ◽  
Robert Helfenstine
Keyword(s):  
System Development ◽  
Stability Augmentation ◽  
Roll Axis

Finite Element Simulation and Analysis for the Working Process of Working-Roll of Carder

2013 ◽  
Vol 670 ◽  
pp. 76-79
Author(s):  
Bao Guo Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Radial Displacement ◽  
Three Dimensional ◽  
Work Roll ◽  
Middle Part ◽  
Working Process ◽  
Element Analysis ◽  
Analog Simulation ◽  
Roll Axis

The three-dimensional models of the Working-roll of Carder are founded by three-dimensional design software Solidworks and the working process of Working-rolls is simulated by finite element analysis software Cosmos, which obtain overall stress distribution for the Working-roll of Carder. The relations between the working-rolls with different thickness and different length of work roll axis and the stress, strain and radial displacement in the working process of working-rolls are attained by finite element analysis and the important factors of impact of work roll deformation are indicated by analog simulation. The results show that the maximum stress and maximum strain are occur in the place of roller connected with the axis rather than to appear in the middle part of roller and the radial displacement in the working process of working-rolls and the length of work roll axis are not directly relationship. The Finite element analysis results provide an important theoretical basis to design a reasonable the length of axis and the thickness of roller for the working-roll of carder.

Effect of active head movements about the pitch, roll, and yaw axes on human optokinetic afternystagmus

1988 ◽  
Vol 66 (6) ◽  
pp. 689-696 ◽  
Author(s):  
S. H. Lafortune ◽  
D. J. Ireland ◽  
R. M. Jell
Keyword(s):  
Head Movements ◽  
Horizontal Velocity ◽  
Velocity Storage ◽  
Long Term Effects ◽  
Otolith Organ ◽  
Complex Interactions ◽  
Roll Axis ◽  
The Right ◽  
Left Movement

Effects of active head movements about the pitch, roll, or yaw axes on horizontal optokinetic afternystagmas (OKAN) were examined in 16 subjects to test the hypothesis that otolith organ mediated activity induced by a change in head position can couple to the horizontal velocity storage in humans. Active head movements about the pitch axis, forwards or backwards, produced significant OKAN suppression. Pitch forward head movements exerted the strongest effect. Active head movements about the roll axis towards the right also produced OKAN suppression but only if the tilted position was sustained. No suppression was observed following sustained yaw. However, an unsustained yaw left movement after rightward drum rotation significantly enhanced OKAN. Sustained head movement trials did not significantly alter subsequent control trials. In contrast, unsustained movements about the pitch axis, which involve more complex interactions, exerted long-term effects on subsequent control trials. We conclude that otolith organ mediated activity arising from pitch or roll head movements couples to the horizontal velocity storage in humans, thereby suppressing ongoing OKAN. Activity arising from the horizontal canals during an unsustained yaw movement (observed mainly with yaw left), following drum rotation in a direction contralateral to the movement, may also couple to the velocity storage, resulting in increased activity instead of suppression.

Fuzzy Logic Controller Designing of an Active Roll Control System for Medium and Large Size Vehicles

2011 ◽  
Vol 110-116 ◽  
pp. 4845-4855 ◽  
Author(s):  
Peiman Hajishafieiha
Keyword(s):  
Fuzzy Logic ◽  
Control System ◽  
Fuzzy Logic Controller ◽  
Roll Angle ◽  
Torsional Stiffness ◽  
Roll Control ◽  
Large Size ◽  
Handling Characteristics ◽  
Active Roll Control ◽  
Roll Axis

The roll / ride trade-off is a long-standing challenge to vehicle dynamicists. Achieving better ride performance almost inevitably leads to increased roll of the vehicle. This roll motion, mostly induced by maneuvering, leads to undesirable handling characteristics and subsequently higher risk of rollover. This paper analyses the use of an Active Roll Control (ARC) system with a Fuzzy Logic Controller (FLC) for improving the handling without sacrificing the ride comfort. The logic for reducing the roll angle of the vehicle is to have some forces exerted by linear actuators on the suspension system, depending on the velocity and steering angle of the vehicle. These forces create a moment about the roll axis which decreases the roll angle. The proposed Fuzzy logic controller is a feedback controller which outputs the correcting roll moment about the roll axis. The effects of employing such a control system are evaluated through computer simulation. Torsional stiffness of the chassis is then taken into consideration to account for unique properties of large-size vehicles. Simulation results with Fuzzy logic controller are very promising and show that the roll performance is significantly improved compared to the vehicle without ARC.

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