Linear actuators
Categories
Zero Boil Off Compressor Based on MICA Actuators
19 June 2023
A reed valve compressor technology for future science spacecraft application, is being developed by CEDRAT TECHNOLOGIES
(CTEC), based on the very compact and high-power MICA300CM actuator (Moving Iron Controllable
Actuator). The present publication details the compressor breadboard design and test results, manufactured in the frame
of an ESA Technological Research Program (TRP), for the testing of a Zero Boil Off Hydrogen storage demonstrator.
The test results presented have been realized at compressor level with Helium gas at CTEC facilities, and the full 20K
Hydrogen storage demonstrator is soon to be tested.
Active control of the spatial MRI phase distribution with optimal control theory
7 November 2019
This paper investigates the use of Optimal Control (OC) theory to design Radio-Frequency (RF) pulses that actively control the spatial distribution of the MRI magnetization phase. The RF pulses are generated through the application of the Pontryagin Maximum Principle and optimized so that the resulting transverse magnetization reproduces various non-trivial and spatial phase patterns. Two different phase patterns are defined and the resulting optimal pulses are tested both numerically with the ODIN MRI simulator and experimentally with an agar gel phantom on a 4.7 T small-animal MR scanner. Phase images obtained in simulations and experiments are both consistent with the defined phase patterns. A practical application of phase control with OC-designed pulses is also presented, with the generation of RF pulses adapted for a Magnetic Resonance Elastography experiment. This study demonstrates the possibility to use OC-designed RF pulses to encode information in the magnetization phase and could have applications in MRI sequences using phase images.
A bistable piezoelectric harvester for wideband mechanical frequency excitation
19 June 2023
The developments of autonomous systems such as for self health monitoring, embedded systems are increasingly used in industrial applications. The energy supply is a key point for the development of such systems. Solutions based on battery have limited life time and the power supplies through wires arenât always appropriate and easy to install. Furthermore, the battery recycling is complex and an expensive process. The researches on power supply through harvesting systems are increasing in the same way the autonomous systems.
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.
Fast and fine Steering Mirrors based on piezoelectric & magnetic actuator technologies for Air and Space
8 August 2022
This review presents CEDRAT TECHNOLOGIES (CTEC) solutions developed for more than 20 years for Fast & fine Steering Mirrors (FSM) as required in air, space, defence & other embedded or demanding applications: Typical appli-cations are for example Lidar, free space optical communication (FSO) and Laser interferometry.
Active flap device for helicopters based on Cedrat Amplified Piezoelectric Actuators
19 June 2023
A project called RPA (Rotor Ă Pales Actives) was launched three years ago to study the possible benefits of implementing active trailing edge flaps on a helicopter main rotor. The main objectives of this project are to decrease BVI noise in descent flight and improve the dynamic behavior of the rotor throughout the largest possible flight domain. After a first phase dedicated to the design of the best flap configuration at scale 1, the second phase of the project deals with the design of a wind-tunnel scale model of a rotor equipped with active flaps. An off-the-shelf piezo-electric actuator is used together with a specific patented flap-driving mechanism. Such an active device was tested under centrifugal loads as well as under aerodynamic loads in order to prepare future wind-tunnel tests. The results obtained under centrifugal loads allowed to clear the active device but the aerodynamic testing showed that some improvements were needed. Corresponding modifications are under way to fully clear the active device to be used on a complete rotor model.
