Flow detection using an artificial vibrissa-like sensor - simulations and experiments. - In: 18th Mechatronika 2018, (2018), insges. 6 S.
everal animal species like rats or seals explore the surrounding environment with their sensory hairs, the so-called vibrissae. Regarding to natural vibrissa, the functionalities of tactile object sensing to receive information about, e.g., the shape and/or the surface texture are often discussed. But, the usage of natural vibrissae to detect flows is reported as well. The necessary information about the flow are coded in the signals recorded at the base of the vibrissa. Due to the natural paragon, we adapt this behavior in order to show up how the information about flows can be extracted from these observables. This is an important procedure because the detection and determination of information about flow effects become interesting for several reasons. For example, in the case of other sensing tasks and strategies like object contour scanning, flows are considered as (possible) disturbances that have to be known to reconstruct any sensed boundary. Otherwise, the flow itself can be of interest. In a first step, simulations are performed to examine the relations between the observables at the base of the sensor and the applied velocity of a flow. Here, a steady-state uniform flow is assumed. The simulations are validated by experiments.
https://ieeexplore.ieee.org/document/8624786
Mechaničeskoe i čislennoe modelirovanie kompaktnoj sistemy dlja defektoskopii indukcionnymi vichrevymi tokami :
Mechanical modeling and simulation of a portable system for Motion Induced Eddy Current Testing. - In: Problems of mechanics, ISSN 1512-0740, (2018), No. 3(72), S. 17-28
The paper deals with the mechanical modeling of a sensor concept in the framework of Motion Induced Eddy Current Testing (MIECT). The system consists of a magnet arrangement with two axially magnetized cylinder magnets, which are fixed to a shaft, driven by a motor with a constant angular velocity. A pick-up coil, assembled around the magnet arrangement and fixed to the sensors framework, measures the magnetic flux varying in time. The mechanical behavior of this experimental setup is analyzed using analytical and numerical methods. The main conclusions concerning the systems behavior are made with the asymptotic method. The investigations based on methods of Bogoliubov & Mitropolski show, that the main contribution to the solution is given by the first fundamental harmonic. The exact equation of motion is integrated numerically. The results of the theoretic investigations are compared with experimental data.
Mathematical models of bio-inspired rotatable sensors with elasticities for object scanning. - In: Proceedings in applied mathematics and mechanics, ISSN 1617-7061, Bd. 18 (2018), 1, e201800264, insges. 2 S.
https://doi.org/10.1002/pamm.201800264
On modeling the bending stiffness of thin semi-circular flexure hinges for precision applications. - In: Actuators, ISSN 2076-0825, Bd. 7 (2018), 4, 86, S. 1-16
Compliant mechanisms based on flexure hinges are widely used in precision engineering applications. Among those are devices such as precision balances and mass comparators with achievable resolutions and uncertainties in the nano-newton range. The exact knowledge of the mechanical properties of notch hinges and their modeling is essential for the design and the goal-oriented adjustment of these devices. It is shown in this article that many analytical equations available in the literature for calculating the bending stiffness of thin semi-circular flexure hinges cause deviations of up to 12% compared to simulation results based on the three-dimensional finite element model for the considered parameter range. A close examination of the stress state within the loaded hinge reveals possible reasons for this deviation. The article explains this phenomenon in detail and shows the limitations of existing analytical models depending on specific geometric ratios. An accurate determination of the bending stiffness of semi-circular flexure hinges in a wide range of geometric parameters without the need for an elaborate finite element analysis is proposed in form of FEM-based correction factors for analytical equations referring to Euler-Bernoulli's beam theory.
https://doi.org/10.3390/act7040086
Form- und Parameterfindung von multistabilen Tensegrity-Strukturen mittels Optimierungsalgorithmen und Anwendungen in der Greifertechnik. - Ilmenau : Universitätsbibliothek, 2018. - 1 Online-Ressource (viii, 227 Seiten)
Technische Universität Ilmenau, Dissertation 2018
Der Gegenstand der Arbeit sind Tensegrity-Strukturen mit mehreren stabilen Gleichgewichtskonfigurationen, sogenannte multistabile Tensegrity-Strukturen. Im Vordergrund der Arbeit steht die Entwicklung von Algorithmen, mit denen solche Strukturen entworfen, untersucht und gezielt ausgelegt werden können. Dafür werden Möglichkeiten zur Bestimmung der Gleichgewichtskonfigurationen von multistabilen Tensegrity-Strukturen betrachtet. Des Weiteren wird untersucht, wie Tensegrity-Strukturen so ausgelegt werden können, dass sie vorgegebene Eigenschaften aufweisen. Dazu werden Kenngrößen zur Charakterisierung dieser Eigenschaften definiert. Für beide Aufgabenstellungen werden Optimierungsprobleme hergeleitet. Zur Lösung dieser Optimierungsprobleme werden Algorithmen entworfen, getestet und analysiert. Aufbauend auf diesen theoretischen Untersuchungen liegt ein weiterer Schwerpunkt dieser Arbeit in der Betrachtung der Einsatzmöglichkeiten von multistabilen Tensegrity-Strukturen in der Greifertechnik. Es werden verschiedene Konzepte für die Entwicklung von Greifern aus diesen Strukturen diskutiert. Zu ausgewählten Konzepten erfolgen weiterführende Betrachtungen, unter anderem durch Einbeziehung dynamischer Analysen. Neben theoretischen Untersuchungen dieser Greifer werden die wichtigsten Erkenntnisse experimentell an Funktionsmustern überprüft und potentielle Einsatzgebiete werden aufgezeigt.
https://nbn-resolving.org/urn:nbn:de:gbv:ilm1-2018000245
Portable system for motion induced eddy current testing. - In: Sensors and Measuring Systems, (2018), S. 300-303
https://ieeexplore.ieee.org/document/8436178
Histological evaluation of a cochlear implant electrode array with electrically activated shape change for perimodiolar positioning. - In: Biomedical engineering, ISSN 1862-278X, Bd. 63 (2018), S1, Seite S135
Enthalten in: Biomedical Implants and Devices (2)
https://doi.org/10.1515/bmt-2018-6027
Impact of anatomical variations on insertion forces - an investigation using artificial cochlear models. - In: Biomedical engineering, ISSN 1862-278X, Bd. 63 (2018), S1, Seite S330
Enthalten in: Poster Session
https://doi.org/10.1515/bmt-2018-6051
Minimally invasive mastoidectomy approach using a mouldable surgical targeting system : a proof of concept. - In: Biomedical engineering, ISSN 1862-278X, Bd. 63 (2018), S1, Seite S247
Enthalten in: Computer Assisted Surgery
https://doi.org/10.1515/bmt-2018-6046
detasFLEX - a computational design tool for the analysis of various notch flexure hinges based on non-linear modeling. - In: Mechanical sciences, ISSN 2191-916X, Bd. 9 (2018), 2, S. 389-404
A novel computational design tool to calculate the elasto-kinematic flexure hinge properties is presented. Four hinge contours are implemented. It is shown, that FEM results correlate well with the analytical design tool results. For a given deflection angle of 10˚ and a corner-filleted contour, the deviations of the bending stiffness are between 0.1 % and 9.4 %. The design tool can be beneficial for the accelerated and systematic synthesis of compliant mechanisms with optimized flexure hinges.
https://doi.org/10.5194/ms-9-389-2018