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Beam Balance
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V. Sankaranarayanan – One of the best experts on this subject based on the ideXlab platform.
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State‐constrained stabilization of Beam‐Balance systems
International Journal of Robust and Nonlinear Control, 2008Co-Authors: Arun D. Mahindrakar, V. SankaranarayananAbstract:We present nonlinear control techniques to stabilize a Beam–Balance system with state constraints. We consider two different actuator configurations: the first one is actuated by a cart moving on the Beam, while in the second case, the actuation is by a single electromagnet. In the first case, the constrained stabilization problem is solved via an output feedback controller designed using feedback linearization, Luenberger-like observer and linear matrix inequality based optimization. In the second case, a Lyapunov-based controller is proposed that takes care of both the input and state constraints. Copyright © 2007 John Wiley & Sons, Ltd.
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state constrained stabilization of Beam Balance systems
International Journal of Robust and Nonlinear Control, 2008Co-Authors: Arun D. Mahindrakar, V. SankaranarayananAbstract:We present nonlinear control techniques to stabilize a Beam–Balance system with state constraints. We consider two different actuator configurations: the first one is actuated by a cart moving on the Beam, while in the second case, the actuation is by a single electromagnet. In the first case, the constrained stabilization problem is solved via an output feedback controller designed using feedback linearization, Luenberger-like observer and linear matrix inequality based optimization. In the second case, a Lyapunov-based controller is proposed that takes care of both the input and state constraints. Copyright © 2007 John Wiley & Sons, Ltd.
Walter Kündig – One of the best experts on this subject based on the ideXlab platform.
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measurement of newton s gravitational constant
Physical Review D, 2006Co-Authors: St. Schlamminger, Walter Kündig, E. Holzschuh, Frithjof Nolting, R.e. Pixley, Jürgen Schurr, Ulrich StraumannAbstract:A precision measurement of the gravitational constant $G$ has been made using a Beam Balance. Special attention has been given to determining the calibration, the effect of a possible nonlinearity of the Balance and the zero-point variation of the Balance. The equipment, the measurements, and the analysis are described in detail. The value obtained for $G$ is $6.674\text{ }252(109)(54)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}\text{ }\text{ }{\mathrm{m}}^{3}\text{ }{\mathrm{kg}}^{\ensuremath{-}1}\text{ }{\mathrm{s}}^{\ensuremath{-}2}$. The relative statistical and systematic uncertainties of this result are $16.3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ and $8.1\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, respectively.
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determination of the gravitational constant with a Beam Balance
Physical Review Letters, 2002Co-Authors: St. Schlamminger, E. Holzschuh, Walter KündigAbstract:The Newtonian gravitational constant $G$ was determined by means of a novel Beam–Balance experiment with an accuracy comparable to that of the most precise torsion-Balance experiments. The gravitational force of two stainless steel tanks filled with 13 521 kg mercury on 1.1 kg test masses was measured using a commercial mass comparator. A careful analysis of the data and the experimental error yields $G=6.674\text{ }07(22)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}\text{ }{\mathrm{m}}^{3}\text{ }{\mathrm{k}\mathrm{g}}^{\ensuremath{-}1}\text{ }{\mathrm{s}}^{\ensuremath{-}2}$. This value is in excellent agreement with most values previously obtained with different methods.
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A Beam Balance experiment to determine the gravitational constant
Conference Digest Conference on Precision Electromagnetic Measurements, 2002Co-Authors: St. Schlamminger, E. Holzschuh, Walter KündigAbstract:The goal of our experiment is a precision measurement of the gravitational constant G by means of a Beam Balance. The gravitational forces of two large and movable field masses act on test masses and change their weights. First measurements have been successfully completed with a relative uncertainty of 230 ppm. Since then various upgrades and improvements have been implemented.
Larry W Jenkins – One of the best experts on this subject based on the ideXlab platform.
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the rotarod test an evaluation of its effectiveness in assessing motor deficits following traumatic brain injury
Journal of Neurotrauma, 1994Co-Authors: Robert J Hamm, Brian R Pike, Dianne M Odell, Bruce G Lyeth, Larry W JenkinsAbstract:ABSTRACT The purpose of the present experiment was to examine the effectiveness of a modified rotarod test in detecting motor deficits following mild and moderate central fluid percussion brain injury. In addition, this investigation compared the performance of the rotarod task with two other commonly used measures of motor function after brain injury (Beam–Balance and Beam-walking latencies). Rats were either injured with a mild (n = 14) or moderate (n = 8) level of fluid percussion injury or were surgically prepared but not injured (n = 8). All rats were assessed on all tasks for 5 days following their respective treatments. Results revealed that both the mild and moderate injury levels produced significant deficits in the ability of the animals to perform the rotarod task. Performance on the Beam–Balance and Beam-walking tasks were not significantly impaired at the mild injury level. It was only at the moderate injury level that the Beam–Balance and Beam-walking tasks detected deficits in motor perform…
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The effect of age on motor and cognitive deficits after traumatic brain injury in rats.
Neurosurgery, 1992Co-Authors: Robert J Hamm, Larry W Jenkins, Bruce G Lyeth, Daphne M. White-gbadebo, Ronald L. HayesAbstract:Abstract Age is one of the most important predictors of outcome after human traumatic brain injury. This study used fluid percussion brain injury to investigate the effects of aging on outcome after brain injury in rats. Three-month-old (n = 8) and 20-month-old (n = 11) rats were injured at a low level (1.7-1.8 atm) of fluid percussion brain injury or received a sham injury (n = 6 for both age groups). Body weight and motor function (Beam Balance and Beam walking) were assessed before injury and for the first 5 days after injury. Cognitive outcome was assessed with the Morris water maze on Days 11 to 15 after injury. Injury did not produce significant weight loss in either age group. At the low level of brain injury used in this study, the 3-month-old rats did not demonstrate any significant motor deficits on the Beam–Balance or Beam-walking tasks. However, the 20-month-old rats displayed significant Beam–Balance deficits on each of the 5 postinjury test days and significant Beam-walking deficits for the first 3 postinjury days. Although Morris water maze performance was impaired in both age groups, the magnitude of impairment was greater in the aged animals. These data demonstrate that traumatic brain injury in the aged animal is marked by increased motor and cognitive deficits, in the absence of pronounced compromise of the animal’s general health.(ABSTRACT TRUNCATED AT 250 WORDS)