Publications
Categories
Design of a dynamic tribometer applied to piezo inertia drive motors
7 November 2019
In Inertia Drive Motors, generated motion is based on stick-slip principle. Current analytical models are predictive enough to calculate qualitatively their optimal performances, such as maximal step size and speed, with relatively few input parameters. Butn they do not take into account the contact life and temporal evolution of parameters as friction factor all along lifetime of IDM. So analytical models reach their limitswhen precise predictions are necessary.
Design of a dynamic tribometer applied to piezoelectric Inertia Drive Motors – In situ exploration of stick-slip principle
19 June 2023
In Inertia Drive Motors, generated motion is based on stick-slip principle. Current analytical models are predictive enough to calculate qualitatively their optimal performances, such as maximal step size and speed, with relatively few input parameters. But, they do not take into account the contact life and temporal evolution of parameters as friction factor all along lifetime of IDM. So, analytical models reach their limits when precise predictions are necessary. This investigation aims at understand wear mechanisms to model temporal evolution of friction. Such an understanding requires the reconstitution of the contact life through the evaluation of 1st and 3rd body flows. To do so, a new IDM-representative tribometer is designed. First bodies – coated TA6V and polymer – are not see-through. They are replaced alternatively by an intermediate transparent first body to observe the contact dynamically and in-situ. Friction factor, step size and mean speed are also measured. Preliminary results shows that wear profiles from real IDM and tribometer are similar. Direct observations bring out particles of TA6V coating are firstly snatched, then moves in contact and finally trigs others particle detachments.
Testing of amplified piezoelectric actuator in a combined vibration and acceleration
19 June 2023
Sandia National Laboratories has previously tested a capability to impose a 7.5 g-rms (30 g peak) radial vibration load up to 2 kHz on a 25 lb object with superimposed 50 g acceleration at its centrifuge facility. This was accomplished by attaching a 3,000 lb Unholtz-Dickie mechanical shaker at the end of the centrifuge arm to create a “Vibrafuge”. However, the combination of non-radial vibration directions, and linear accelerations higher than 50g’s are currently not possible because of the load capabilities of the shaker and the stresses on the internal shaker components due to the combined centrifuge acceleration.
Development of magnetic fast steering mirror prototype for optical pointing applications
7 June 2018
Fast Steering Mirrors are core products continuously developed by Cedrat Technologies (CTEC) for optical pointing applications, for Space, and Optronic domains. During the last decade, main development efforts where focused on piezoelectric mechanisms technology, in order to achieve ultra-high frequency bandwidth control performance over small angle strokes. New applications under maturation in Europe, such as laser optical communication, require much higher angle strokes compared to the existing state of the art, which cannot be easily achieved by piezoelectric technology. Therefore CTEC is focusing on the development of a new Fast Steering Mirror family based on high angle stroke magnetic actuators. This paper presents this new steering mechanism concept, and the prototype performance results expected.
The design and qualification of the piezo actuated
19 June 2023
As part of the Lisa Technology Package (LTP) on board the LISA-PATHFINDER spacecraft, the LISAPATHFINDER interferometer is of the heterodyne Mach-Zehnder type. It requires as input two light beams derived from the same source but with a small frequency difference (a few kHz). These two optical beams are produced in the Laser Assembly (LA) via the “Laser Modulation Unit” (LMU). The LMU includes an optical bench, two Acousto-Optic Modulators and two Optical Delay Lines [1].
Development of the plain bearing and flexure bearing MICA300CM actuator
7 May 2018
The MICATM linear actuator family (Moving Iron Controllable Actuator) is being continuously improved at CEDRAT TECHNOLOGIES (CTEC) for applications needing high controllable stroke, force, and power. The MICA300CM is a new actuator model, having improved configuration based on cylindrical shape. A first version based on plain bearing offers up to 12mm stroke and 300N continuous force with a weigh of only 3kg. A second version is based on new frictionless flexure bearings. The former one is especially designed to achieve zero maintenance over several years of operation, with high efficiency, infinite resolution, and high controllability performance. This version of the MICA300CM has been derived to offer a proof mass configuration, for vibrationcancellation applications on machining processes. A latest version is also currently under design, and prototyping, specifically for reciprocating power piston applications, such as compressors, pressure wave generators, and pumps. Its high efficiency, ultra-long lifetime capability, and compactness, makes it perfectly suitable for embedded thermal machines based on Stirling, Joules Thomson, and Rankin Thermodynamic cycles. This paper presents this 4 design concepts, their test results and perspective for applications.
