Real-time closed-loop control for micro mirrors with quasistatic comb drives

Research output: Contribution to book/conference proceedings/anthology/reportConference contributionContributedpeer-review

Contributors

Abstract

This paper presents the application of a real-time closed-loop control for the quasistatic axis of electrostatic micro scanning mirrors. In comparison to resonantly driven mirrors, the quasistatic comb drive allows arbitrary motion pro files with frequencies up to its eigenfrequency. A current mirror setup at Fraunhofer IPMS is manufactured with a staggered vertical comb (SVC) drive and equipped with an integrated piezo-resistive deflection sensor, which can potentially be used as position feedback sensor. The control design is accomplished based on a nonlinear mechatronic system model and the preliminary parameter characterization. In previous papers [1,2] we have shown that jerk-limited trajectories, calculated offline, provide a suitable method for parametric trajectory design, taking into account physical limitations given by the electrostatic comb and thus decreasing the dynamic requirements. The open-loop control shows in general unfavorable residual eigenfrequency oscillations leading to considerable tracking errors for desired triangle trajectories [3]. With real-time closed-loop control, implemented on a dSPACE (R) system using an optical feedback, we can significantly reduce these errors and stabilize the mirror motion against external disturbances. In this paper we compare linear and different nonlinear closed-loop control strategies as well as two observer variants for state estimation. Finally, we evaluate the simulation and experimental results in terms of steady state accuracy and the concept feasibility for a low-cost realization.

Details

Original languageEnglish
Title of host publicationMOEMS AND MINIATURIZED SYSTEMS XV
EditorsW Piyawattanametha, YH Park
PublisherSPIE - The international society for optics and photonics, Bellingham
Number of pages13
Publication statusPublished - 2016
Peer-reviewedYes

Conference

TitleConference on MOEMS and Miniaturized Systems XV
Duration15 - 17 February 2016
CitySan Francisco
CountryCanada

External IDs

Scopus 84987657191
ORCID /0000-0003-3259-4571/work/142249651

Keywords

Keywords

  • real-time closed-loop control, quasistatic microscanner, electrostatic staggered vertical comb drive, flatness-based and sliding-mode control, normal form and high-gain observer