PROJECT TITLE :

Self-Tuning Mechanism for the Design of Adaptive Secondary Mirror Position Control

ABSTRACT:

Deformable mirrors (DMs) are electromechanical devices used in ground-primarily based telescopes to catch up on the distortions caused by the atmospheric turbulence, the most factor limiting the resolution of astronomical imaging. Adaptive secondary mirrors (ASMs) represent a brand new type of DMs; 2 of them are recently put in on the 8-m-category massive binocular telescope (LBT). ASMs can jointly correct rigid and nonrigid wave-front distortions thanks to the use of force actuators distributed on the overall mirror surface. As an offset, every actuator needs to be piloted by a fervent controller, whose parameters should be accurately tuned to obtain the specified mirror shape. At the present time, the calibration of the controller parameters is executed manually. This paper presents a completely unique automatic controller tuning procedure that does not depend upon the modeling of the mirror dynamics. The experimental validation on a prototype reproducing the three innermost rings of the LBT ASM is reported.