Cedrat Technologies, innovation in mechatronics

The MICA linear actuator technology (Moving Iron Controllable Actuator) is being continuously improved at CEDRAT TECHNOLOGIES (CTEC) for applications needing high controllable stroke, force, and power. The MICA20CS Proof Mas Actuator is a new actuator model, which is now completing the CTEC Proof Mass Actuator family together with the MICA300CM.

A reed valve compressor technology for future science spacecraft application, is being developed by CEDRAT TECHNOLOGIES (CTEC), based on the very compact and high-power MICA300CM actuator (Moving Iron Controllable Actuator). The present publication details the compressor breadboard design and test results, manufactured in the frame of an ESA Technological Research Program (TRP), for the testing of a Zero Boil Off Hydrogen storage demonstrator. The test results presented have been realized at compressor level with Helium gas at CTEC facilities, and the full 20K Hydrogen storage demonstrator is soon to be tested.

An actuator is rescaled for integration into a compressor used for the liquefaction of hydrogen vapor boil off, into a propellant storage system. The goal is to evaluate the feasibility of liquid hydrogen zero boil off, for long duration storage at 20 Kelvin cryogenic liquid condition. This article presents the actuator trade off, selection and special features imposed by the application. The actuator design is presented, its characteristics are measured, and resulting performances are presented and discussed.

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.

In the field of aeronautics, some parts of aircraft engines are tricky and costly to manufacture. In the low pressure turbine very thin pieces obtained by turning require a complex support. The R&D work performed here aims at improving the manufacturing process through the reduction of vibrations and active modification of the clamping conditions. For that purpose, Cedrat Technologies has designed a new innovative Moving Iron Controllable Actuator (MICA), which is embedded on the work-piece support. In the first part, the application goals and the main particularities of the developed MICA200M magnetic actuator are presented. To be easily driven in closed loop, the force is designed to be linear with the current and independent from the interface position. The MICA200M stroke is ±2.5mm and its force constant reaches 11.6N/A for a current range of ±15A in steady state. The nominal force of 174N for only 1 dm3 size and 3.2kg facilitates the integration and allows acceleration up to 132G in transient operation thanks to reduced 0.25kg mobile mass. In the second part, results of complete experimental characterisation are detailed. Finally, a comparison analysis is done with COTS voice coil actuators and the article concludes with the benefits of the MICA200M.

Many applications require long-term position stability, which relates to the notion of absolute precision over time. Until now, the long-term stability of strain gages (SG) for position measurement was questionable. Using its extensive know-how of strain gages integration and new instrumentation equipment, Cedrat Technologies has managed to demonstrate nanometric position stability of a closed-loop piezo-mechanism with integrated strain gages sensors. This technology opens a wide range of new possibilities for industrial, aeronautical, and space applications.

While Cedrat Technologies has been active in space for more than 20 years with piezoelectric mechanisms, we have also been increasingly involved over the last few years in the development of magnetic actuators for space projects. In this paper, a focus is made on the case of magnetic actuators that are developed in the frame of the Meteosat Third Generation (MTG) project. The first one is the Scan Assembly (SCA) actuated by Rotating Voice Coil Motors (RVCM) for the East/West (E/W) axes and the North/South (N/S) axes developed in collaboration with Sener and the second one is the Voice Coil Motor (VCM) developed in collaboration with CSEM for the Corner Cube Mechanism (CCM)