Support and actuation of the segmented primary mirror of the E-ELT Dr.ir. Gert Witvoet

What is TNO? Netherlands organisation for applied scientific research Founded by law in 1932 About 3000 employees February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT 2

TNO mission TNO connects people and knowledge to create innovations that boost the competitive strength of industry and the well-being of society in a sustainable way. TNO bridges the gap between academia and industry We do this by Consultancy Contract research Testing and certification Licences Performing statutory assignments February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT 3

TNO Optomechatronics (OM) Offering optimal multi-disciplinary solutions to high-precision problems synergy between various disciplines Focus on design and realization of OM equipment high-end single piece prototypes / instruments February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT 4

Application domains Semicon Space Astronomy Big science Metrology / inspection Medical Manufacturing equipment Oil & gas …. February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT 5

European Extremely Large Telescope (E-ELT) February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT 6

Inside the E-ELT February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT 7 Will be the largest ground- based telescope in optical and near IR range

E-ELT: the primary mirror Total diameter: 39.3 m 798 hexagonal segments of 1.4 m corner-to-corner (1.2 m flat-to-flat) 6 identical mirror segment sets (M1) One support system (M1SS) for 133 different mirror segments Passive and active compensation of surface form deformations of individual segments Active co-alignment of segments via piston-tip-tilt actuators February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT 8

TNO’s ambition for E-ELT Get Dutch industry involved Via design and realization of M1 support structure (M1SS) Segment actuators (PACT) February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT 9

TNO M1SS design February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT 10

TNO Position Actuator (PACT) design Some requirements: Static load: 0 – 900 N Operating angles: 0 – 90° Stroke: 15 mm Tracking velocity: 1.2 μm/s Positioning accuracy: 1.7 nm RMS while tracking in presence of ground and wind disturbances February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT 11

PACT test program E-ELT relevant test setup allows 360° angular testing 90 kg test mass inside passive suppression of ground vibrations February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT 12

PACT dynamics Clean dynamics up to nearly 400 Hz Constant dynamics over full 15 mm stroke February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT 13

PACT controller design High-bandwidth control on fine stage Low-bandwidth control on coarse stage for off-loading fine stage force February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT 14

Measured tracking performance Spectrum over 0.5 mm back and forth, 1.2 μm/s February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT nm RMS!

Current work: M1SS-PACT assembly February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT 16

February 02, 2015 Dr.ir. Gert Witvoet M1SS and PACT for E-ELT 17