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).
In the frame of the Cleansky 2 projects SYNJET3C and FLOCOS, CEDRAT TECHNOLOGIES (CTEC) and TRISITEC are collaborating with both FRAUNHOFER and ONERA institutes, two major European research leaders in the development of Synthetic Jet Actuators (SJA) for Aerospace applications. While SYNJET3C project is dedicated to SJA mechanical designs and optimisation, as well as testing including wind tunnel tests, FLOCOS project is dedicated to the design and manufacturing of a specific SJA drive Electronic called SADS (Synthetic Jet Actuator Drive System).
Free-Space Optics and Deep Space Optical Communication request new compact low-power high-stroke high-bandwidth Fast Steering Mirrors. To address this need, CEDRAT TECHNOLOGIES has developed a Magnetically-actuated Fast Steering Mirror called M-FSM, taking heritage of its MICA™ technology. This mechanism offers Rx Ry strokes larger than +/-2° with a 250Hz bandwidth when tilting a 10mm-diameter mirror. Closed loop control is achieved using integrated eddy current sensors. Requested power is reduced leading to low heating and allowing high duty cycle. Vibration tests allow to define first limits and conditions for the M-FSM to bear external vibrations.
Abstract: 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.
A project called RPA (Rotor à 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.
Fast growing Laser and new optic applications drive more and more needs for beam steering mirrors (BSM) and Fast Steering Mirror (FSM). For space optic instruments, CEDRAT TECHNOLOGIES has developed for 20 years several piezoelectric tip-tilt mechanisms. Presented recent examples include the ATLID BSA small tit tilt for quasi static nano pointing and MEFISTO, a large tit tilt for fast micro positioning. These space mechanisms perform high precision functions while being compact, lightweight and resistant to external vibrations and shocks. As shown in the paper, these advantages allow these technologies addressing several needs for other optronic applications than space, such as active stabilisation, micro scanning, disturbance compensation in IR imagers or telescopes.