Mechatronic Systems
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Experimental assesment and further development of amplified piezo actuators for active flap devices
6 January 2002
RPA (Rotor à Pales Actives) Franco-German project was launched three years ago to study the possible benefits of implementing active trailing edge flaps on a helicopter main rotor. The main expected effects concern the decrease of BVI noise in descent flight and the improvement of the dynamic behaviour of the rotor throughout the largest possible flight domain. The technological solution adopted to deflect the flap of an 1/3rd scale rotor demonstrator, uses an off-the-shelf elliptic amplified actuator, from Cedrat Recherche Company, driving an innovative patented mechanism.
Extreme performance of piezo system: High stroke, high frequency, high temperature
19 June 2023
This paper presents research and development results of the high performances piezoelectric actuators. Performed studies were concentrated on the improvement of three major parameters: stroke, maximum driving frequency and operational temperature. Two, new actuators were presented and described in this paper. First presented actuator has increased maximum displacement. This actuator has doubled the stroke of standard, long stroke actuators. Improvement of the second actuator was concentrated on increase of constant driving frequency. Finally, special encapsulations designed for both actuators allow using them at high temperatures. Development of these two, new actuators was done simultaneously to the improvement of the electronics. High power amplifier presented in this paper provides sufficient current to drive both actuators at high frequencies.
Rosetta Midas successful launching
19 June 2023
Successful commissioning of the first flight application for C. T. in ESA / ROSETTA mission. The ROSETTA satellite has been successfully launched the 2nd of March 2004 from Kourou, French Guyana, using an Ariane-5 G+ launcher. The rendezvous with the new targeted comet “Churyumov – Gerasimenko” is expected in November 2014.
Active damping of vibrations applied on ski structures
19 June 2023
Since many years the field of active controls of vibration is growing up and a lot of new applications using smart actuators are developed. In the following study, these concepts are adapted and applied on a general structure of ski to damp the large modes of vibrations keeping the robustness of the control and the static loads during the ride.. Simulations integrating FEM models coupling to electromechanical model were elaborated to obtain the principal performances and to study the stability of the loop.
Active flap device for helicopters based on Cedrat Amplified Piezoelectric Actuators
19 June 2023
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.
Cardiolock: an Active Cardiac Stabilizer
19 June 2023
Off-pump Coronary Artery Bypass Grafting (CABG) is still today a technically difficult procedure. In fact, the mechanical stabilizers used to locally suppress the heart excursion have been demonstrated to exhibit significant residual motion. We therefore propose a novel active stabilizer which is able to compensate for this residual motion. The interaction between the heart and a mechanical stabilizer is first assessed in vivo on an animal model. Then, the principle of active stabilization, based on the high speed vision-based control of a compliant mechanism, is presented. In vivo experimental results are given using a prototype which structure is compatible with a minimally invasive approach.
