FP7 LED A.Jeremie, L.Brunetti, N.Geffroy

State of the art. b) Current limitations that need to be addressed to achieve 1nm above 1Hz and 0.1nm above 5Hz. c) Potential means to overcome these limitations. d) A rough idea of a potential schedule. It would be useful to keep in mind that we would like to use the sensors in the project. e) Resources needs and availability. 4) Potential programme to develop the software for the design of the module and to control the feedback. (Andrea)

Resonances of : -beam -support Rejection de 6 résonances : (sans et avec asservissement) sur un petit prototype Resonances of : -beam -support

Feedback output: Actuator at the fixed-part of the beam State of the art inertial sensors Feedback output: Actuator at the fixed-part of the beam In nm conditions and “uncontrolled” ground motion excitation: peaks are large=> new feedback algorithm based on internal command

Simulation Dynamic response with feedback SAMCEF External perturbation Structure Dynamic response Dynamic equation Sensors Feedback loop Actuators MATLAB -Simulink

Current work to overcome SAMCEF/MATLAB interface difficulties FE Model (Super-Element) SAMCEF State model (A,B,C,D) Perturbation Mouvement MATLAB Simulink Control (Internal model control and/or State representation) Sensors Actuators Difficulty: complexity and accuracy of mechanical model

- Enhance the perturbation around a given frequency fc TMC Isolator « Passive » rubber: - Enhance the perturbation around a given frequency fc - Damp perturbations above fc Transfer function for passive material fc « Active » :- Active isolation in the frequency range enhanced by the passive material frequency =>start building a prototype combining Passive and Active isolation=>develop specific feedback

Multisensor/multiactuator The prototype : Experimental results : Actuator Sensor PZT0 PZTM Optical VG G VB N Very bad No effect Good Very good Girder behaviour changes with instrumental configuration

Resources needed Human resources: Automatics engineer : 36 months or whole 5 years? Mechanical engineer (simulations): 12 months (50%?) Machine shop: 6 months Material resources: Real-time equipment 10000euros performing dedicated PC 17000 euros Milestones: schedule? Internal control under work Multisensors/multiactuators Feedback for mock-up Go from small mock-up to larger one Study passive material Follow the FD support schedule? the FD stability can go over the 5 years of the program. =>construction of test stand until 2009 with specifications well understood =>tests during 2009/2010