Cedrat Technologies, innovation in mechatronics

Micro-switches are frequently used in Space mechanisms to provide telemetry or to provide positive indication of the achievement of a desired position or function such as open, close, ready-to-latch, latched, end of travel, reference position, and for different mechanism applications. Current switches that rely on electro-mechanical technology are not very reliable and are sensitive to mounting orientation, to thermal gradients, and have a limited number of operational cycles, which is a problem for long life application, launch vibrations and shocks loads.

For more than 20 years, CTEC has been involved in various space missions, delivering products designed for severe environment conditions (vibrations, shocks, vacuum, humidity, wide thermal range including cryogenic). Eddy current sensor (ECS) technology, using printed circuit board (PCB) for printed coils, provides both a good resolution/accuracy and a good robustness against temperature variations.These sensors are available commercially off the shelf (COTS).

ATLID (ATmospheric LIDar) is one of the four instruments of EarthCARE satellite, it shall determine vertical profiles of cloud and aerosol physical parameters such as altitude, optical depth, backscatter ratio and depolarisation ratio. The BSA (Beam Steering Assembly), included in emission path, aims at deviating a pulsed high energy UV laser beam to compensate the pointing misalignment between the emission and reception paths of ATLID [1]. It requires a very high stability and high resolution.

Model a contactless proximity sensor that can be used at the same time as limit switch (in deployment mechanisms) or top tower.

Already presented at 2015 ESMATS symposium [1], the CEA-Cryomechanism (CM) is a cryogenic rotating actuator that can operate from room temperature down to cryogenic environments, under vacuum or nitrogen atmosphere. In the framework of the Euclid-NISP space program, after having built two bread board model (BBM) units, CEA has undergone the integration of three qualification model (QM) units, among which one unit is going through a full qualification program (the two remaining units are intended to be qualified at upper system level).

In many cases piezoelectric actuators reach limitations in terms of maximum displacement and cycling frequency. Most amplified actuator technologies struggle to go over the millimeter of stroke. Furthermore certain closed-loop applications demand stroke measurement integrated into the actuator. While few amplifiers on the market can offer 20Amps current over a few 100ms, development of high power supply units runs parallel with actuator improvements. However with the introduction of high power supplies comes the problem of self-heating of the piezo ceramic. Finally extreme environmental conditions in terms of harsh conditions and high temperatures need to be addressed in order to open these markets for piezo actuators. Cedrat Technologies has been heavily investigating in solutions to overcome all of these drawbacks and these solutions are presented here.

Synchrotrons need robust products. That’s why the association of piezo actuator technology and CEDRAT TECHNOLOGIES (CTEC) know-how has been successful for synchrotron mechanisms projects. The technological brick is the “Amplified Piezo Actuator” (APA®) tested and widely used in space applications, it is often implemented in CTEC piezo mechanisms and provides a high level of robustness. Modifying the layout and the number of APA® allows several needs to be addressed within beamlines. Three applications developed in collaboration with the EMBL, PAL and SOLEIL will be presented in this paper. The first application consists of cutting a beam with a piezo shutter. The maximum beam diameter is 3 mm. The second mechanism allows the energy of a beam to be modified by using a series of piezo actuated filters. And the last mechanism aims at modifying the beam section shape with an active piezo micro-slits mechanism.