Linear actuators
Categories
Space Tribometers: Design for Exposed Experiments on Orbit
12 March 2012
Eight pin-on-disk tribometers have been made for testing materials in space on board the International Space Station. They will be exposed directly to the low earth orbit (LEO) environment on board the ââMaterials on the International Space Station Experimentsââ platform where they will experience extreme conditions including atomic oxygen, ultrahigh vacuum, radiation (including UV radiation), and thermal ranges from -40 to 60 C.
Advantages of large piezo actuators and high power drivers for fatigue and fretting test
19 June 2023
Constant expansion of new materials requires fretting or fatigue machines in order to test their failure. In many cases tests must be performed in severe conditions and at high frequency. These requirements come from the use of the materials in highly demanding applications. At the same time it is expected to reduce the time required to characterise such materials. Piezoelectric actuators are more and more common in testing machines, but they still reach limitations in terms of maximum displacement, cycling frequency or power. In order to cope with these issues, Cedrat Technologies has been investigating solutions. In this paper long stroke and high frequency actuators, coupled with powerful driving control are introduced. These actuators are based on piezoelectric materials and can be easily integrated into the fatigue machines. In order to improve precision of these tests, two of the most common displacement sensors used in smart actuators are also presented in this paper.
Fine stepping piezo actuator for IASI-NG
7 June 2018
Many applications and more specifically space projects would have use of a stable sub-micrometre positioning actuator. In order to meet this need, Cedrat Technologies has designed the new FSPA brand. This linear stepping actuator offers sub-micrometric positioning resolution along 5mm stroke combined with high actuation force (>100N) and the ability to hold its position without power. Starting from the FSPA, a special version is being developed for the IASI-NG space instrument. This light (500g), fully redundant actuator is designed to achieve 150”m stroke with locking at rest, 60 N force with a 25-50 nm step resolution and resistance to launching. The paper presents the base FSPA actuator and the new high performance space variant.
Lpm motor test
19 June 2023
We are delighted in announcing the successful test of our LPM20 linear piezoelectric motor, carried out in June this year at the CNES (French Agency Space), Toulouse in vacuum conditions.Developed for positioning applications, the piezoelectric motor
has proved to be a very interesting solution thanks to its high massive force, its zero consumption at rest and its high precision. For space applications, it is a question of obtaining an identical behaviour in ambient and in vacuum conditions.
However, the friction drive that is the key to the functioning of the piezoelectric motor, limits the lifespan and poses tribology problems.
Advanced Landing Gears for Improved Impact Absorption
6 January 2008
The presented project ADLAND (AST3-CT-2004-502793) dealt with evaluating the options for adaptive shock absorbers to be applied in aircraft landing gears. Analytical design procedures were developed to simulate different potential design options and a best practice solution determined. The different hardware components regarding adaptive shock absorbers were then developed and tested with regard to adaptive landing gear model. The objectives of the project were: to develop a concept of adaptive shock-absorbers, to develop new numerical tools for design of adaptive absorbers and for simulation of the adaptive structural response to an impact scenario, to develop technology for actively controlled shock-absorbers applicable in landing gears, to design, produce and perform repetitive impact tests of the adaptive landing gear model with high impact energy
dissipation effect, to design, produce and test in flight the chosen full-scale model of the adaptive landing gear.
Long stroke/High resolution tip tilt mechanism
19 June 2023
Multi degree of freedom (dof) mechanisms are widely required into micro or macro manipulation fields as well as in optronics functions. Commonly available mechanisms may be divided into two main categories. The first is industrial robots (serial or parallel). These offer large range of motion, in rotation and translation. Their resolution is usually limited in the sub-millimeter range. The second category achieves very high resolution motion (sub-nanometer) but is limited to a few decades of microns. A way to combine both long stroke and resolution is to use piezo motors into multi dof mechanisms. The aim of this paper is to present a combination of both advantages into a low volume tripod actuator. The Tripod Actuator by Cedrat Technologies (TrAC) is a 3 dof mechanism offering +/-35° rotation around X and Y axis and a 10mm Z translation stroke into a low volume of Ă50x50mm.
