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Vibration isolation of an extended object
19 June 2023
An increasing number of applications required a very high level of precesion: semiconductor manufacturing, atomic force microscopy, scanning probe microscopy, machine tool, etc. Such high precision can only be reached in very stable environments. the standard procedure is to mount the sensitive equipment on a heavy isolating stage, sometimes referred to as optical table, which can be either passive or active.
ERMR08: Self locking MRF latch and damper
8 January 2008
MRF actuators are new electromechanical components using Magneto Rheological Fluids (MRF). When submitted to a high enough magnetics fiels, MRF switch from a liquid to a near solid body.
Active control of vibrations of a space truss using amplified piezoelectric actuators
19 June 2023
The new piezo actuators manufactured by Cedrat Technologies have been developed for the positioning control of space optics but they are spreading widely in various engineering fields such as precise positioning, intelligent control of shapes and generation or control of vibrations. Their ability for the control or active damping of vibrations has been successfully demonstrated at the lab scale in space applications. In a first case, the piezo actuators were used for both for the control of launching vibrations and the positioning control in orbit of a telescope mirror. In a second set of space applications, these piezo actuators have been successfully integrated in a space truss using active tendons for control of micro vibrations, as publicly released at the Industry Space Days (ISD2001, Noordwijk, 9-10 Mai 2001) and as presented in this paper.
Active damping of vibrations applied on ski structures
19 June 2023
Since many years the field of active controls of vibration is growing up and a lot of new applications using smart actuators are developed. In the following study, these concepts are adapted and applied on a general structure of ski to damp the large modes of vibrations keeping the robustness of the control and the static loads during the ride.. Simulations integrating FEM models coupling to electromechanical model were elaborated to obtain the principal performances and to study the stability of the loop.
Ski embbeded piezo system
19 June 2023
Since many years, the field of active control of vibrations has been growing up and many new applications using smart actuators have been developing. In 2003, CEDRAT TECHNOLOGIES in collaboration with SKI ROSSIGNOL initiated a project supported by ESA where these concepts (smart material and active control of vibration) were adapted and applied on a ski structure. The project aim was to damp the large modes of vibrations keeping the robustness of the control and the static loads during the ski ride.
A new amplified piezoelectric actuator for precise positioning and active damping
19 June 2023
Two typical characteristics of direct piezoelectric actuators are displacements of ten micrometers and high stiffnesses. recently, multilayers actuators have been improved, and they now display strains of approximately 1200ppm at low excitation levels (less than two hundred volts). Thus, they are well suited to perform precise positioning of optical devices. But for industrial needs, this performances is still insufficient for positioning devices with larger displacements (in the range of several hundred micrometers).