DFG Forschungsprojekt: Kick and Catch - cooperative microactuators for freely moving platforms

Jade Welt: Jade Hochschule entwickelt mikrotechnische Systeme weiter (German) 

Kick and Catch - cooperative microactuators for freely moving platforms

The aim of this research proposal Kick and Catch is to evaluate concepts and prototypes of microactuators which are not suspended to cantilevers but move freely between several stable end positions. Several kinds of actuators have to cooperate to provide the here proposed sudden displacements. The following state of the art focuses on the fact of freely moving microactuators with fast as well as big displacements, on Model Order Reduction (MOR) of large-scale multiphysics finite element models and on model-based controller design all of which are relevant for Kick and Catch.


Project Groups:

Ulrike Wallrabe, University of Freiburg, Department of Microsystems Engineering, Laboratory for Micoactuators, Georges-Köhler-Allee 102, 79110 Freiburg

Martin Hoffmann, Ruhr-Universität Bochum, Chair for Microsystems Technology, Universitätsstraße 150, 44801 Bochum

Christoph Ament, University of Augsburg, Chair for Control Engineering, Eichleitner Straße 30, D-86159 Augsburg

Tamara Bechtold, Jade University of Applied Sciences, Department of Engineering, Modeling and Simulation of Mechatronic Systems, Friedrich-Paffrath-Straße 101, 26389 Wilhelmshaven


The Bechtold Group for modeling and simulation of mechatronic systems at the Jade University of Applied Sciences aims to develop methodologies for generation of system-level models of Kick and Catch microactuator systems. This work contributes to the work of the Ament group, as an actuator model is essential for control development. Furthermore, the Hoffman and the Wallrabe groups benefit from this work, as the availability of an accurate and efficient model is beneficial in their respective device designs. Furthermore, those methodologies will be applicable to a broad class of cooperative multistable microactuator system models.

The system-level Kick and Catch actuator model will integrate two sub models, the electromagnetic Catch actuator model and the electrostatic respectively piezoelectric Kick actuator model. The micro actuators considered here include nonlinear structural dynamics (with periodic contacts between sphere and platform), electrostatic and magnetic fields for actuation and position sensing. To model these effects with sufficient accuracy, multiphysical numerical models are necessary. Sub models are highly accurate, but too large to be employed within a control loop. Furthermore, the strongly different duration of the kick, spin, fly and catch periods, impose extremely high requirements on modelling the contact events in an adequate way. It is thus the of the Bechtold group to develop suitable methods for order reduction of multiphysical field-solution models and supply those to the Ament group for integration in the control loop. Beyond the present microactuators systems, those methods will be applicable to other multiphysical models, especially under the presence of time-varying contacts and nonlinear effects.


Observer-based control-scheme of the Kick and Catch actuator integrating a system-level model, which consists of a reduced order model (ROM), a lumped element (LE) model or a look-up table (LT) derived from finite element models. The system-level model describes the actuator's behavior in response to voltage and current excitation; in response it provides flying mass' and platform positions. The model supports controller development.


Prof. Dr. -Ing. Ulrike Wallrabe; Prof. Dr. -Ing. Martin Hoffmann; Prof. Dr. -Ing. Christoph Ament; Prof. Dr. -Ing. Tamara Bechtold