@inproceedings{SchorrSchaleOtterbachetal., author = {Schorr, Philipp and Schale, Florian and Otterbach, Jean Marc and Zentner, Lena and Zimmermann, Klaus and B{\"o}hm, Valter}, title = {Investigation of a Multistable Tensegrity Robot applied as Tilting Locomotion System}, series = {Proceedings of the 2020 IEEE International Conference on Robotics and Automation (ICRA): 31 May-31 August 2020, Paris}, booktitle = {Proceedings of the 2020 IEEE International Conference on Robotics and Automation (ICRA): 31 May-31 August 2020, Paris}, doi = {10.1109/ICRA40945.2020.9196706}, pages = {2932 -- 2938}, abstract = {This paper describes the development of a tilting locomotion system based on a compliant tensegrity structure with multiple stable equilibrium configurations. A tensegrity structure featuring 4 stable equilibrium states is considered. The mechanical model of the structure is presented and the according equations of motion are derived. The variation of the length of selected structural members allows to influence the prestress state and the corresponding shape of the tensegrity structure. Based on bifurcation analyses a reliable actuation strategy to control the current equilibrium state is designed. In this work, the tensegrity structure is assumed to be in contact with a horizontal plane due to gravity. The derived actuation strategy is utilized to generate tilting locomotion by successively changing the equilibrium state. Numerical simulations are evaluated considering the locomotion characteristics. In order to validate this theoretical approach a prototype is developed. Experiments regarding to the equilibrium configurations, the actuation strategy and the locomotion characteristics are evaluated using image processing tools and motion capturing. The results verify the theoretical data and confirm the working principle of the investigated tilting locomotion system. This approach represents a feasible actuation strategy to realize a reliable tilting locomotion utilizing the multistability of compliant tensegrity structures.}, language = {en} } @inproceedings{BoehmSchorrSchaleetal., author = {B{\"o}hm, Valter and Schorr, Philipp and Schale, Florian and Kaufhold, Tobias and Zentner, Lena and Zimmermann, Klaus}, title = {Worm-Like Mobile Robot Based on a Tensegrity Structure}, series = {2021 IEEE 4th International Conference on Soft Robotics (RoboSoft): 2.04.2021 - 16.04.2021, New Haven, CT, USA}, booktitle = {2021 IEEE 4th International Conference on Soft Robotics (RoboSoft): 2.04.2021 - 16.04.2021, New Haven, CT, USA}, publisher = {IEEE}, isbn = {978-1-7281-7713-7}, doi = {10.1109/robosoft51838.2021.9479193}, pages = {358 -- 363}, abstract = {This work presents a novel concept to develop mobile robots enabling crawling locomotion in tubular environment. Chain-like systems are designed by serial cascading a uniform tensegrity module. Inspired by the movement of worms in nature, an undulating shape change of the system is targeted to generate locomotion. The shape changeability of an exemplary tensegrity module due to internal actuation is examined in simulations and experiments. A prototype consisting of these tensegrity modules is manufactured and the locomotion principle is verified in experiments. Comparing to existing prototypes this approach enables an enhanced compliance due to the modular assembly of tensegrity structures.}, language = {en} } @inproceedings{ChavezVegaSchorrScharffetal., author = {Chavez Vega, Jhohan Harvey and Schorr, Philipp and Scharff, Moritz and Schale, Florian and B{\"o}hm, Valter and Zimmermann, Klaus}, title = {Towards Magneto-Sensitive Elastomers Based End-Effectors for Gripping Application Technologies}, series = {2019 IEEE International Conference on Mechatronics (ICM), 18-20 March 2019, Ilmenau, Germany}, volume = {1}, booktitle = {2019 IEEE International Conference on Mechatronics (ICM), 18-20 March 2019, Ilmenau, Germany}, publisher = {IEEE}, doi = {10.1109/ICMECH.2019.8722922}, pages = {217 -- 222}, abstract = {Nowadays, the demands in engineering systems become more challenging and the use of conventional materials for certain applications is not suitable. This issue encourages the investigation of novel and innovative materials in soft robotics field. A promising approach is the consideration of magneto-sensitive elastomers (MSE). These materials enable a useful adaptability responding to their mechanical properties. By applying a static magnetic field, the static and dynamic characteristics can be tuned. However, currently the knowledge about the correlations are not satisfying and the resulting material properties can only be predicted approximately with the use of time-expensive simulations regarding to the nano scale. Therefore, feasible material simulations of the description of the mechanical behavior are necessary. In this paper experimental studies of the influence of a static magnetic field on the mechanical properties and shape adaptability of MSE are presented. Furthermore, based on these results a simulation for the material behavior is executed. These results can be implemented into further simulations for various MSE exemplars.}, language = {en} } @article{BeckerBoehmSchaleetal., author = {Becker, Tatiana I. and B{\"o}hm, Valter and Schale, Florian and Zimmermann, Klaus}, title = {Vibrating sensor unit made of a magnetoactive elastomer with field-adjustable characteristics}, series = {Journal of Magnetism and Magnetic Materials}, volume = {498}, journal = {Journal of Magnetism and Magnetic Materials}, number = {March}, publisher = {Elsevier}, doi = {10.1016/j.jmmm.2019.166196}, abstract = {The present work deals with the investigation of the oscillatory behavior displayed by a vibrating sensor unit made of a magnetoactive elastomer (MAE). Since this type of smart materials consists of an elastic matrix and micro-magnetic particles, it reveals exceptional magnetic-field-dependent material properties. The forced vibration response under the bending of the MAE unit subjected to in-plane harmonic kinematic excitation of the housing is studied. It is found that the amplitude-frequency characteristics of the MAE unit can be changed considerably by means of an external homogeneous magnetic field. With and without applied field, the unit displays different steady-state responses for the same excitation, and the resonance occurs at various ranges of the excitation frequency. The nonlinear phenomenon of the resonance hysteresis is observed depending on whether the excitation frequency increases or decreases. It is shown that the MAE vibrations can be detected based on the magnetic field distortion measurements. The presented prototype of the MAE-based vibrating unit with field-adjustable "configuration" can be potentially implemented for realization of acceleration sensor systems with adaptive sensitivity.}, language = {en} }