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ABC Rotor blades: design, manufacturing and testing
19 June 2023
ABC is the acronym for ‘’Active Blade Concept’’ and represents a 38% Mach scaled model rotor of the Advanced Technology Rotor (ATR) of Eurocopter Germany (ECD, [4]). In contrast to the ATR the model rotor is fully articulated. Specifically, it is equipped with a flap at the trailing edge of each blade, which is driven by a piezoelectric actuator. The ABC project is a cooperation between the French ONERA and the German DLR within the research concept ‘’The Active Rotor’’.
Contactless Position sensors for space mechanisms based on eddy current sensing
19 June 2023
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).
Long stroke/High resolution tip tilt mechanism
19 June 2023
Multi degree of freedom (dof) mechanisms are widely required into micro or macro manipulation fields as well as in optronics functions. Commonly available mechanisms may be divided into two main categories. The first is industrial robots (serial or parallel). These offer large range of motion, in rotation and translation. Their resolution is usually limited in the sub-millimeter range. The second category achieves very high resolution motion (sub-nanometer) but is limited to a few decades of microns. A way to combine both long stroke and resolution is to use piezo motors into multi dof mechanisms. The aim of this paper is to present a combination of both advantages into a low volume tripod actuator. The Tripod Actuator by Cedrat Technologies (TrAC) is a 3 dof mechanism offering +/-35° rotation around X and Y axis and a 10mm Z translation stroke into a low volume of Ø50x50mm.
Stiff and soft stewart platforms for active damping and active isolation of vibrations
6 January 2002
As future astronomic missions will require more and more stringent resolution requirements, the high demand for an environment clean of vibrations and disturbance appears. This also leads to the need for high precision steering devices for fine pointing of sensitive optics with the highest possible accuracy. Several methods exist to reduce vibration levels: the first consists in isolating the sensitive system from the perturbation and the second in damping the structure vibration modes. Therefore, two Stewart platforms have been designed, manufactured and tested. The first is a soft hexapod that provides 6 degree-of-freedom (DOF) active isolation and the second is a stiff hexapod that provides active damping to whatever flexible payload attached/mounted to it. In addition, both hexapods have steering capabilities.
Cryogenic piezo characterisation and integration For Fine Steering Tip/Tilt Mechanism
19 June 2023
High precision cryogenic applications are demanding domains that require precise knowledge of component performance. In the case of active components such as piezoelectric actuators, such knowledge includes stroke, capacitance and Coefficient of Thermal Expansion (CTE). These parameters are difficult to define with precision because of the combination of small displacements and low temperature sensor compatibilities. A high stability and low sensibility test bench is required to obtain such results
Magnetically actuated fast steering mirrors
19 June 2023
Free-Space Optics (FSO) for optical communication request new compact low-power high-stroke high-bandwidth Fast
Steering Mirrors (FSM). To address this need, CEDRAT TECHNOLOGIES has developed a Magnetically-actuated Fast
Steering Mirror called M-FSM, taking heritage of its MICA™ actuators. This FSM offers Rx Ry strokes larger than +/-
2° with a 250Hz bandwidth when tilting a 31mm diam mirror. Requested power is minimized leading to low heating.
Vibration tests have been performed to define first limits and conditions for the M-FSM to bear external vibrations. Large
bandwidth closed loop control is achieved using integrated eddy current sensor and a state feedback-based controller.
