Publications
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Magnetic Fast Steering Mirror for Inter-satellites and Feeder Link Optical Communication
14 June 2024
In order to cope with performances of Fine Pointing, and Fast Steering mirror requirements for Space Optical Communi-cation, CEDRAT TECHNOLOGIES (CTEC) is developing magnetic Fast Steering Mirror’s (M-FSM) family, based on proprietary MICA™ flexure bearing magnetic actuators mechanism (Moving Iron Controllable Actuator), with embedded eddy current sensors (ECS).
FSM design expected for Optical Inter-Satellite Link (OISL) in large-scale New Space constellations, is highly driven by mandatory cost-efficiency for high quantities recurrent production, while FSM design expected for Feeder-Link commu-nication is driven instead by high power Laser requirements together with high level of redundancy.
In this publication CTEC is presenting both the M-FSM45 and M-FSM-HPL designs, and test results, respectively for inter-satellites and feeder link optical communications.
Improving dynamic accuracy of closed loop bandwidth of piezo mechanisms with advanced control laws and embedded eddy current position sensors
14 June 2024
Fast Steering Mirrors (FSM) play an important role in diverse optical applications for beam stabilization, image sharpening or dynamic beam steering. These applications require the FSM to have a precise response across a large frequency range, thus the need of a dynamic controller. But the controller is ultimately limited, among other factors, by the performance of the sensor: its ability to measure accurately the required physical value and with a sufficient bandwidth. The compact, dynamic and precise embedded Eddy Current Sensors (ECS) developed by Cedrat Technologies, combined with a model-based controller allow a two and a half times improvement on the bandwidth compared to current sensing technology, while being more precise overall.
A wideband vibration energy harvester with integrated energy management designed for harsh environment.
14 June 2024
Bistable energy harvesters (BEH) are well adapted devices to deal with the variation of the vibration source frequency spectrum. Indeed, the non-linear motion of this kind of harvester allow to reach a harvesting bandwidth up to 50% of the resonant frequency compared to 1-2% of the resonant frequency typically for conventional linear energy harvesters. CEDRAT TECHNOLOGIES proposes a design using buckled beam and Amplified Piezoelectric Actuator (APA®) technology based on an architecture patented by the USMB. The nonlinear behavior of such a kind of energy harvester has already been studied in the literature and has demonstrated promising results.
Due to the use of buckled beam, the bistable energy harvester is very sensitive to the thermal expansion resulting from the harsh environment. In this paper, it is proposed an improved design to manage the thermal expansion and ensure harvesting capabilities on a wide temperature range from -40°C to +80°C.
Furthermore, an electronic extraction circuit has been implemented to deliver a regulated output voltage to power an IoT. Moreover, this electronic circuit can deal with spontaneous excess of energy by storing it into a supercapacitor or a battery and sink this energy to still powering the IoT when the vibration level decrease. The BEH with the electronic extraction circuit can generate a power of 8mW.
The combination of an athermalized Bistable Energy Harvester with an electronic extraction circuit increases the technological readiness level to be integrated in system subjected to harsh environment like railway application for instance.
New range of light driven actuation devices
12 October 2023
The recent progresses made in the manufacturing of new plasmonic photomobile films are offering innovative solutions for light induced motion actuators and devices. Indeed, such films can be assimilated as transducers thanks to their ability to convert light into displacement with strokes up to several millimeters. By adjusting the incident light parameters (wavelength, exposure time…) the photomobile films actuation can be controlled to answer many applications requesting high displacements and low forces. In these regards, the behaviour of the photomobile films were characterized prior to their integration in more complex devices. Then, several proof-of-concepts of these devices were manufactured to try to bring new functionalities to the market such as light driven optical switch, optical micro-valve, and deflector:
– The optical switch features interesting properties in term of electrical insulation by eliminating the dark currents responsible for noise in image sensors. It also exploits the large stroke of the photomobile films to achieve the standard electrical insulation distance versus emitter voltage.
– Light driven micro-valves/micro-pumps are suitable for delivering a small quantity of fluids with high precision for example in medical devices. Using this technology, a fluid circuit can be opened and closed when light is switched from on to off (or inversely) without embedded electric power.
– Optical deflectors are used widely in optical pointing applications where fast responses and/or high precisions are critical. An appropriate understanding of the photomobile films behaviour enables to control the direction of the beam deflection within large angular ranges.
Real-Time Image Super Resolution System Based on Micro-scanning Technology
5 September 2023
Different from the recent popular super resolution system based on AI technology which needs normally massive training datasets, the micro-scanning super resolution system by integrating the high-precision mechanism and the image processing system can overpass the training datasets limit to enhance the image resolution and quality considerably in real time. Such a real-time image super resolution system named Quick Demo Station (QDS) system is presented. This system is jointly developed by Shanghai IAE, China, in cooperation with Cedrat technologies, France. The system is made of two modules, one imaging module (MicroScan_ VIS_Module ), the other image processing module (a portable image processing workstation). The image processing module performs imaging module’s control, as well as image acquisition, image registration, image superresolution reconstruction, image contrast enhancement. Here the algorithm used to restore the low-resolution (LR) images is the iterative reconstruction method, which could achieve high quality super-resolution (SR) results. The output is a video stream whose frame rate is higher than 25 frames per second. The system is being tested in different applications and show the excellent super-resolution results, including low light level conditions and outdoor variable lighting scenarios. Furthermore, the algorithm in image processing module can be used not only on the workstations, but also in embedded processing system.
P-FSM and M-FSM piezoelectric and magnetic fast steering mirrors
5 September 2023
To meet needs in air, space, defence & other embedded or demanding applications CEDRAT TECHNOLOGIES (CTEC) bas developed for more than 20 years Fast Steering Mirrors (FSM). Typical applications are for example Lidar, free space optical communication (FSO) and Laser interferometry. As the specifications met in these applications can vary, CTEC bas designed and patented different actuation technologies:
– FSM based on Amplified Piezo Actuators APA®, as for PHARAO, ATLID, PSYCHE missions, and for future FSO space constellations as well as other large FSM for space & instrumentation as ESO ELT.
– FSM based on Magnetic Actuation, as being developed for FSO and CO-OP optical communication toward Geosat.
– FSM based on Stepping Piezo Actuators, as for IASI-NG for METOP-SG, as well as other piezomotor-based FSM.
The presentation describes the working principle, design and performance of these different actuation concepts.
