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Modeling and dynamic simulation of a closed chain free-floating planar manipulatorShelly, Michael Patrick. January 1992 (has links)
Thesis (M.S.)--Ohio University, March, 1992. / Title from PDF t.p.
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Teleoperation of mechanical manipulators aboard the US space stationPan, Ya-Dung, 1960- January 1987 (has links)
This study presents a new analytical controller design strategy for the teleoperation of mechanical manipulators aboard the U.S. space station. This controller design strategy emphasizes on the stability of a closed-loop control system involving time delay. Simplified dynamic equations of the Stanford arm are considered as the manipulator model. A local linearizing and decoupling control algorithm is applied to linearize and decouple the dynamic equations. Once the linear form of the manipulator is obtained, a model prediction control loop is constructed and implemented as a digital controller to provide the predictive states information, and a particular model reduction method is applied to yield a reduced-order digital controller. This reduced-order digital controller is a highly self-tuned controller which can control the closed-loop system with time delay by following a specified performance.
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Dynamics and control of a rigid/flexible manipulatorYeh, Chun-tien 01 April 1992 (has links)
Control of high-speed, light-weight robotic
manipulators is a challenge because of their special
dynamic characteristics. In this work, a two-stage
control algorithm for the position control of flexible
manipulators is proposed. First, the more complex,
flexible robot system is replaced by a simplified
hypothetical rigid body system (HRRA) with off-line
trajectory planning. This reduces the complexity of the
controller design for the flexible robotic arm. A
parameter-optimization approach was adopted to minimize
the difference between these two models in this stage.
Also, a comparison of computational efficiency is made
among the methods of calculus-of-variations, dynamic-programming,
and the proposed parameter-optimization. At
the second stage, simple linear state feedback
controllers, based on the simplified hypothetical rigid
body model, are proposed to control the actual robotic
system. With the feedback gains selected properly by the
pole-placement and linear quadratic methods, the results
show satisfactory achievement of the motion objectives.
The algorithm is implemented for a two-link
rigid/flexible robotic arm, and the results indicate that
the procedure is capable of providing effective control
with much simpler computational requirements than those
of procedures published previously. / Graduation date: 1992
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Mechanistic characterization of members of the amidohydrolase superfamilyMarti Arbona, Ricardo 15 May 2009 (has links)
The amidohydrolase superfamily is a functionally diverse group of enzymes
found in every organism sequenced to date. The landmark for this superfamily is the
conservation of a (beta/alpha)8-barrel structural fold. Isoaspartyl dipeptidase (IAD) from
Escherichia coli catalyzes the hydrolytic cleavage of beta-aspartyl dipeptides. Structural
studies of the wild-type enzyme demonstrate that the active site consists of a binuclear
metal center. Bell-shaped pH-rate profiles are observed for all four metal-substituted
forms of the wild-type enzyme and the site-directed mutants, E77Q and Y137F.
Structural analysis of IAD with the bound substrate and site-directed mutagenesis shows
the importance of the side chains of residues Glu-77, Tyr-137, Arg-169, Arg-233, Asp-
285, and Ser-289 in the substrate binding and hydrolysis. The reaction mechanism for
the hydrolysis of dipeptides by IAD is initiated by the polarization of the amide bond via
complexation to the beta-metal and the hydrogen bond to Tyr-137. Asp-385 participates in
the activation of the bridging hydroxide for nucleophilic attack at the peptide carbon
center. The lately protonated Asp-285 donates the proton to the alpha-amino group of the
leaving group, causing the collapse of the tetrahedral intermediate and cleavage of the
carbon-nitrogen bond. N-formimino-L-glutamate iminohydrolase (HutF) from Pseudomonas aeruginosa acts in the deimination of the fourth intermediate of the
histidine degradation pathway, N-formimino-L-glutamate. An amino acid sequence
alignment between HutF and other members of the amidohydrolase superfamily
containing mononuclear metal centers suggests that the residues Glu-235, His-269, and
Asp-320 are involved in substrate binding and deimination. Site-directed mutagenesis of
Glu-235, His-269, and Asp-320, in conjunction with the analysis of the four metalsubstituted
enzyme forms and pH-rate profiles provides valuable information toward the
proposal of a mechanism for deimination of N-formimino-L-glutamate by HutF. This
information suggests that the reaction is initiated by the activation of the hydrolytic water
through base catalysis via His-269. The enhanced nucleophile attacks the formimino
carbon center. In a concerted reaction, Asp-320 deprotonates the hydroxide nucleophile,
and His-269 donates a proton to the terminal amino of the iminium group resulting in the
collapse of the tetrahedral intermediate, the cleavage of the carbon-nitrogen bond and the
release of the products.
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A web based compression spring design calculator /Ma, Huiyuan. January 2001 (has links)
Thesis (M.S.)--University of Wyoming, 2001. / The compression spring design calculator is available on the World Wide Web. Includes bibliographical references (leaf 50).
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Deflections of Belleville SpringsFaust, William Morray, 1936- January 1961 (has links)
No description available.
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Design and control principles for flexible manipulator arms using active and passive controlLane, Jeffrey Scott 05 1900 (has links)
No description available.
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The design of a planar acting manipulator and its controlField, Lawrence Elliot 05 1900 (has links)
No description available.
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Controlling flexible manipulators, an experimental investigationHastings, Gordon Greene 08 1900 (has links)
No description available.
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Digital control for flexible manipulator armsTahboub, Karim Abdul Majid 05 1900 (has links)
No description available.
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