In the context of the Large Binocular Telescope project, we present the results of force actuator calibrations performed on an adaptive secondary prototype called P45, a thin deformable glass with magnets glued onto its back. Electromagnetic actuators, controlled in a closed loop with a system of internal metrology based on capacitive sensors, continuously deform its shape to correct the distortions of the wavefront. Calibrations of the force actuators are needed because of the differences between driven forces and measured forces. We describe the calibration procedures and the results, obtained with errors of less than 1.5%.
© 2008 Optical Society of America
Optical Design and Fabrication
Original Manuscript: January 14, 2008
Revised Manuscript: April 3, 2008
Manuscript Accepted: May 23, 2008
Published: July 7, 2008
Davide Ricci, Armando Riccardi, and Daniela Zanotti, "Calibration of force actuators on an adaptive secondary prototype," Appl. Opt. 47, 3631-3636 (2008)