Linear actuators
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Extreme performance of piezo system: High stroke, high frequency, high temperature
19 June 2023
This paper presents research and development results of the high performances piezoelectric actuators. Performed studies were concentrated on the improvement of three major parameters: stroke, maximum driving frequency and operational temperature. Two, new actuators were presented and described in this paper. First presented actuator has increased maximum displacement. This actuator has doubled the stroke of standard, long stroke actuators. Improvement of the second actuator was concentrated on increase of constant driving frequency. Finally, special encapsulations designed for both actuators allow using them at high temperatures. Development of these two, new actuators was done simultaneously to the improvement of the electronics. High power amplifier presented in this paper provides sufficient current to drive both actuators at high frequencies.
Rosetta Midas successful launching
19 June 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
7 January 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
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 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.
