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Showing 1 to 20 of 50 for “"Vibration Suppression"”.
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Airfoil Vortex Induced Vibration suppression devices
Vortex Induced Vibrations (VIV) is a major concern of the offshore oil industry. This problem leads to fatigue failure in the marine risers and causes costly replacement of the risers. Appendages such as helical strakes have proven that VIV can be eliminated but at the cost of increased drag. …
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Vibration Suppression using Orthogonal Eigenstructure Control
… eigenstructure control is developed for active vibration cancellation in structures. Orthogonal eigenstructure control is a feedback control method applicable to multi-input multi-output linear systems. While the available control design methodologies offer a large and complex design space of …
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Vibration suppression in finite length marine cable systems
The vibration suppression effectiveness of a flexible in-line marine cable vibration absorber is studied. The transfer matrix method is used to build various numerical models of vibration absorbers in marine cable systems. The models determine cable system natural frequencies, mode shapes and modal …
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Optimal variable stiffness feedback control for structural vibration suppression
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1993.
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Optimal Vibration Suppression Using On-line Pole/Zero Identification
… at adding damping to structures and suppressing vibration. The poles and zeros of the control-to-output transfer function were accurately identified by the pole/zero identification routine. However, the closed-loop performance was shown to be very dependent on the correct placement of sensor and …
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Broadband Piezoelectric Energy Harvesting and Vibration Suppression Using Nonlinear Mechanisms
Harvesting ambient vibration energy provides a promising solution to implement self-powered microwatts to milliwatts low-power electronic devices, as an alternative to batteries. Due to the high power density and simple construction, piezoelectric transducers have attracted the most attention in …
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Active Vibration Suppression for Wafer Transfer Systems in Semiconductor Fabrication Plants
Vibration suppression is critical in precision mechatronic systems for nanofabrication. In semiconductor plants, automated wafer handling is performed by Overhead Hoist Transport (OHT) vehicles that transport wafers in front opening unified pods (FOUPs). When the wafers are transported in FOUPs, …
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Vibration Suppression Using Smart Materials in the Presence of Temperature Changes
… satellite structures are also subject to various vibration sources. Passive and active vibration suppression techniques have been developed to minimize acoustic noise and fatigue stress damage. Featuring low weight solutions and high performance, active control techniques are becoming increasingly …
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Analysis of an Anti-vibration Glove for Vibration Suppression of a Steering Wheel
Exposure to severe levels of hand-arm vibration can lead to hand-arm vibration syndrome. Towards curbing the development of hand-arm vibration syndrome, studies have shown that anti-vibration gloves effectively reduce the transmission of unwanted vibration from vibrating equipment to the human …
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Electrical analogs for plate equations and their applications in mechanical vibration suppression by P.Z.T. actuators
Before the beginning of digital-computers era, a lot of research was carried out in order to find electric circuits the governing equations of which were analogous to the ones of mechanical systems. The mentioned circuits were called ectro-mechanical analogs. They were used as analogical computers …
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The Linear DC Motor as a proof mass actuator for vibration suppression in large space structures
… that it provides the forces necessary to damp vibrations in a large flexible structure. The design is broken down into three steps where in each step, a feedback loop is placed around the actuator and/or the structure. The first loop is a motor compensation loop which effectively decouples the …
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Position control and vibration suppression of a flexible beam-like structure cantilevered from a rotary actuator within a gravitational field
… experimental investigation into the position and vibration control of beam-like structures within a gravity field using only root actuation was performed. Two methods were used to linearize the system's equations of motion. This, in turn, allowed for the use of powerful Modern Control Theory …
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Transient analysis and vibration suppression of a cracked rotating shaft with ideal and nonideal motor passing through a critical speed
… Galerkin Method is applied. Longitudinal vibration, shear deformation and torsional vibration are neglected. In the second part of this study, the vibration suppression of a cracked, simply supported, rotating shaft with a rigid disk is discussed, with an ideal and a nonideal motor, …
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Performance improvement of a proof-mass actuator using nonlinear control
… thesis, the proof-mass actuator is studied for vibration suppression of a flexible structure. While these actuators have a favorable force-to-weight ratio, the finite travel of the proof-mass, called the stroke length, imposes restrictions on the use of the actuator. This restriction implies …
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Combined Mechanical and Command Design for Micro-Milling Machines
… speed of existing micro-mills will lead to vibration and trajectory following problems. If a micro-mill cannot be positioned precisely, then part tolerances cannot be maintained. Thus any increase in throughput would be counterproductive in terms of overall performance. This dissertation …
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Hybrid Active/Passive Models with Frequency Dependent Damping
… has shown it to be an effective method of vibration suppression. In this work, two new hybrid configurations are introduced by separating the passive and active elements. In the first variation, the active and passive element are constrained to the same side of the beam. The other variation …
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Output feedback rotational maneuvers and vibration damping of Nasa Scole system by inversion theory
… the question of large rotational maneuver and vibration stabilization of NASA Spacecraft Control Laboratory Experiment System (SCOLE). The mathematical model of SCOLE System includes the dynamical equations for rigid body slew maneuver and three dimensional vibration of the rigid space shuttle, …
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Macro-Fiber Composites for Sensing, Actuation and Power Generation
… for two major themes, sensing and actuation for vibration control, and power harvesting. The MFC is constructed using piezofibers embedded in an epoxy matrix and coated with Kapton skin. The construction process of the MFC affords it vast advantages over the traditionally used piezoceramic …
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