Dynamic analysis and control of mirror segment actuators for the European Extremely Large Telescope
article
Segmented primary mirror telescopes require dedicated piston-tip-tilt actuators for optimal optical performance. Netherlands Organisation for Applied Scientific Research (TNO) has developed various prototypes of such actuators, in particular for the E-ELT. This paper presents the dynamics analysis and feedback control results for a specific two-stage prototype. First, the dynamics of the actuator in interconnection with the to-be-positioned mass has been analyzed, both using frequency response measurements and first principles modeling, resulting in a detailed understanding of the dynamic behavior of the system. Next, feedback controllers for both the fine and the coarse stage have been designed and implemented. Finally, the feedback-controlled actuator has been subjected to a realistic tracking experiment; the achieved results have demonstrated that the TNO actuator is able to suppress wind force disturbances and ground vibrations with more than a factor 103, down to 1.4 nm root mean square, which is compliant with the requirements.
Topics
TNO Identifier
522400
DOI
https://dx.doi.org/10.1117/1.JATIS.1.1.019003
Source
Journal of astronomical telescopes, instruments, and systems
Publisher
SPIE
Collation
14 p.