Publications

Rosetta Midas successful launching

June 19, 2023

Successful commissioning of the first flight application for C. T. in ESA / ROSETTA mission. The ROSETTA satellite has been successfully launched the 2nd of March 2004 from Kourou, French Guyana, using an Ariane-5 G+ launcher. The rendezvous with the new targeted comet “Churyumov - Gerasimenko” is expected in November 2014.

Rotating piezo actuator for high accuracy positioning in space applications

January 7, 2002

Piezo-electric motors have been successfully developed for various applications like autofocus drives in camera lenses and handling equipment for semiconductor production. Their high speed and accurate positioning capability, combined with a favourable holding torque in unpowered condition, make piezo motors also very attractive for actuation purposes in spacecraft mechanisms. However, so far only a few studies have been reported considering their suitability for actual use in space.

Zero Boil Off Compressor Based on MICA Actuators

June 19, 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.

3D ultrasonic imaging probes

January 1, 2001

Implementation of 3D capabilities on ultrasonic imaging systems tantalizingly proves the high interest for this diagnosing modality. However, to become a clinical tool, 3D ultrasound has to spend further technological efforts in acquisition performance and probe size to deliver on the fly, quality volumetric images as well as current functionalities.

Active control of the spatial MRI phase distribution with optimal control theory

November 7, 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

June 19, 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 aren’t 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.