Showing papers on "Active vibration control published in 1986"
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TL;DR: In this paper, the steady-state vibration amplitudes of a cantilever beam with vibration absorbers are determined by the assumed-modes method, and the results obtained are presented in graphical form.
59 citations
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TL;DR: In this article, a method of vibration control of large space structures by simultaneously integrating the structure and control design to reduce the structural response from a disturbance is presented. But the structural modifications are achieved by using a nonlinear mathematical optimization technique.
Abstract: This study provides a method of vibration control of large space structures by simultaneously integrating the structure and control design to reduce the structural response from a disturbance. The formulation of the design scheme is obtained by the structural modification of some nominal finite element model, which is controlled in an optimal fashion by a linear regulator, to increase the active modal damping factor beyond that of the nominal structure. The structural modifications are achieved by using a nonlinear mathematical optimization technique. The objective function is the weight of the structure with a constraint on the damping parameter of the closedloop system. The application of the algorithm is illustrated by designing an ACOSS-FOUR model with different constraint values.
57 citations
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25 Mar 1986TL;DR: In this article, a driving circuit for a vibration wave motor is proposed, in which a periodic voltage is supplied to electromechanical energy converting elements to generate a travelling vibration wave in a vibrating member.
Abstract: A driving circuit for a vibration wave motor, in which a periodic voltage is supplied to electromechanical energy converting elements generates a travelling vibration wave in a vibrating member, thus causing a relative movement between the vibrating member and a movable member. For achieving effective operation of the vibration wave motor, the driving circuit controls the amplitude of the periodic voltage supplied to the electromechanical converting elements according to the drive state of the vibration wave motor.
54 citations
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TL;DR: In this paper, a two mass vibration isolator was proposed for linear reciprocating machines. But the isolator is an elastomer with a damping ratio of at least 0.1 sandwiched between two retainers.
Abstract: A two mass vibration isolator particularly suited to a linear reciprocating machine. Vibration into and out of the machine is attenuated by an isolator placed between the machine and its mounting frame. The isolator is an elastomer with a damping ratio of at least 0.1 sandwiched between two retainers.
28 citations
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TL;DR: In this article, the authors consider the construction of hybrid models for flexible structures, including both the natural spatially distributed dynamics of low-mass density structures and the lumped models associated with rigid-body dynamics.
Abstract: In this paper we consider the construction of hybrid models for flexible structures, including both the natural spatially distributed dynamics of low-mass density structures and the lumped models associated with rigid-body dynamics. For the purposes of active control of structural vibrations we argue that by using transform methods, the standard approach to transfer function (or mechanical impedance) modeling can be extended to provide a complete formulation of a hybrid model with localized control. We proceed to give a systematic procedure for obtaining the required transfer functions and Green's functions for the hybrid model dynamics consisting of one-dimensional elastic elements (such as beams, rods, and cables) together with rigid-body (lumped) models. We focus on a well-known family of models for elastic elements together with various reductions and indicate the construction of well-posed state-space models for these systems. Using the resulting state-space, we next demonstrate the construction of a complete frequency domain characterization of the elemental system response using transfer functions and Green's functions. Hybrid constructions are discussed for various interconnections of distributed and lumped elements, and a simple illustrative example is given. We highlight the extent to which the required computations can be performed automatically on a digital computer using a computer algebra system.
20 citations
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TL;DR: A semiconductor vibration detecting structure formed on a semiconductor substrate and a method of manufacturing the same in which the curvature of the cantilever of the vibrational structure in the direction gradually deviating from the surface of the semiconductor substrategies can be determined by the thickness of the upper nitride layer.
Abstract: A semiconductor vibration detecting structure formed on a semiconductor substrate and a method of manufacturing the same in which the curvature of the cantilever of the vibration detecting structure in the direction gradually deviating from the surface of the semiconductor substrate can be determined by the thickness of the upper nitride layer for regulating the curvature of the cantilever, with the thicknesses of the other layers constituting the cantilever and the length thereof being constant. In the semiconductor vibration detecting structure according to the present invention, even if vibrations having relatively large vibration levels are applied to the detecting structure, the cantilever of the vibration detecting structure vibrates well but never hits the surface of the semiconductor substrate, thus enabling a wide rage of mechanical vibrations to be detected with a high sensitivity.
17 citations
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11 citations
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05 Sep 1986
TL;DR: A vibration transducer as discussed by the authors contains a vibration bar which consists of an n-type layer and is fixed at at least one end and is shaped by selective etching of a silicon monocrystal with foreign atoms.
Abstract: A vibration transducer contains a vibration bar which consists of an n-type layer and is fixed at at least one end and is shaped by selective etching of an n-type layer which has been produced by local doping of a silicon monocrystal with foreign atoms. Furthermore, the vibration transducer contains devices for allowing the vibration bar to vibrate as well as devices for tapping off the vibration of the vibration bar. The vibration transducer is capable of measuring pressure, temperature, density etc. by detecting a change in the resonance frequency of the vibration bar. The vibration bar can be finely etched independently of its doping density in that it is formed in an aqueous alkaline solution with the application of a negative direct voltage or a pulsating voltage to a p-type layer and of a positive direct voltage or a pulsating voltage to an n-type layer. The vibration and tap-off devices for the vibration bar can be readily provided by constructing a diode and a transistor, enclosing the vibration bar, in the vibration transducer.
10 citations
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TL;DR: Controle actif des vibrations d'un systeme paliers-rotor a modes multiples par un algorithme adaptatif is discussed in this paper, where it is shown that the vibrations of a paliers rotor can be modelled by an adaptive algorithm.
Abstract: Controle actif des vibrations d'un systeme paliers-rotor a modes multiples par un algorithme adaptatif
4 citations
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TL;DR: In this paper, a centrifugal pendulum absorber to reduce ship superstructure vibration was developed, which is claimed to be easy to install and can be used in any ship.
Abstract: A centrifugal pendulum absorber to reduce ship superstructure vibration was developed. It is compact and claimed to be easy to install. Vibration of any order caused by engine or propeller can be reduced, random variations of amplitude and phase can be automatically followed, and other structures are not excited by the absorber.
01 Jan 1986
TL;DR: The study provides a new quasi-modal control method for a control system design of an active control bearing system in which feedback coefficients are determined on the basis of a modal analysis.
Abstract: This paper investigates a design method of an active control bearing system with only velocity feedback. The study provides a new quasi-modal control method for a control system design of an active control bearing system in which feedback coefficients are determined on the basis of a modal analysis. Although the number of sensors and actuators is small, this quasi-modal control method produces a control effect close to an ideal modal control.
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TL;DR: In this paper, the forced vibration response of a beam structure having an electromagnetic damper with velocity feedback is investigated theoretically and experimentally, and the effects of the amplifier gain of the control system upon the vibration control efficiency and the response of the system are clarified.
Abstract: In the present report, the forced vibration response of a beam structure having an electromagnetic damper with velocity feedback is investigated theoretically and experimentally The beam structure is subjected to a harmonic exciting force, and the vibrations are controlled by the electromagnetic damper consisting of an electromotive linear actuator and a velocity sensor using rare-earth magnets as well as control circuit In the analysis, the simultaneous equations under Bernoulli-Euler bending theory in consideration of both the beam structure and the control system are solved exactly Furthermore, the effects of the amplifier gain of the control system upon the vibration control efficiency and the response of the system are clarified
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01 Jan 1986
TL;DR: In this article, a principle of piezoelectric damping of vibration is developed for both thickness and longitudinal vibrations, which can be used as a new type of damper.
Abstract: Since the vibration behaviours of a piezoelectric vibration system change with an electrical load, the Vibration of such a system will be damped, when the electrical load includes a resistance component Based on this effect, a principle of piezoelectric damping of vibration is developed
In this paper, piezoelectric damping configurations for both thickness and longitudinal vibrations are experimentally studied The results show that the piezoelectric material may become a new type of material for damping and the piezoelectric vibrator can be used as a new type of damper
The piezoelectric damping adjustment is convenient and can be carried out continuously and instantaneously