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XY200M a new design of piezo stage
9 January 2002
The XY200M is an XY piezo stage coming from CEDRAT TECHNOLOGIES lab and which was newly designed according to space needs defined with CNES (the French space agency). This XY stage benefi ts from the heritage of a former XY stage
developed for ESA (European Space Agency) in the frame of Rosetta / Midas space mission which will launch in the beginning of 2003. It is based on two pairs of APA200M, Amplifi ed Piezo Actuators displaying 200 µm of stroke each, arranged in cross configuration around a central ring.
Recent advances in active damping and vibration control
6 January 2002
This paper reviews some concepts used for active vibration control and vibration isolation. It is divided into two parts. Part 1 reviews some control strategies based on collocated control systems, which offer promising results for space and civil engineering applications. Part 2 (starting at section 4) is focused on automobile applications.
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.
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.
Experimental assessment of an active flap device
5 January 2002
During the past thirty years, noticeable consideration has been devoted to the improvement of rotary-wing vehicles, with respect to noise, vibrations and performance. The main rotor of helicopters, and more precisely the blades themselves have been the subject of numerous optimization studies.
