Scientific publications without theses

Results: 829
Created on: Wed, 17 Jul 2024 23:04:53 +0200 in 0.0680 sec

Böhm, Valter; Kaufhold, Tobias; Zeidis, Igor; Zimmermann, Klaus
Dynamic analysis of a spherical mobile robot based on a tensegrity structure with two curved compressed members. - In: Archive of applied mechanics, ISSN 1432-0681, Bd. 87 (2017), 5, S. 853-864

The use of mechanically compliant tensegrity structures in mobile robotics is an attractive research topic. The mechanical properties and therefore the locomotion performance of mobile robots based on these structures can be adjusted reversibly during locomotion. In the present work, a rolling mobile robot, based on a simple tensegrity structure, consisting of two rigid disconnected curved members connected to a continuous net of eight prestressed tensioned members with pronounced elasticity, is considered. Pure rolling uniaxial locomotion and also planar locomotion can be realized with small control effort, induced by the movement of two internal masses. After kinematic considerations, the nonlinear equations of motion are derived and transient dynamic analyses are performed, to study the system behavior. Also the dependency of the rolling movement behavior on structural and actuation parameters is discussed. The uniaxial and planar locomotion performance of the system are verified experimentally.
Sumi, Susanne; Böhm, Valter; Zimmermann, Klaus
A multistable tensegrity structure with a gripper application. - In: Mechanism and machine theory, Bd. 114 (2017), S. 204-217

Multistable tensegrity structures are a new interesting class of compliant prestressed structures. Due to their beneficial properties, these structures are attractive for robotic applications. In this paper a gripper is introduced, which is based on a mechanical compliant, multistable tensegrity structure. The underlying tensegrity structure of the considered gripper is investigated in detail. The influence of the member parameters on the existence of multiple states of self-equilibrium and the mechanical compliance is discussed with the help of static geometric nonlinear analyses, based on the Finite Element Method. The dynamical behaviour of the structure, during the change between the equilibrium configurations, is considered. Therefor the dynamical equations of motion are derived. Then gripper arms are added to the tensegrity structure to obtain a gripper. Different actuation principles for the gripper are discussed. Additionally, a prototype of the gripper has been built and is presented, as well as, selected experimental results.
Volkova, Tatiana I.; Böhm, Valter; Kaufhold, Tobias; Popp, Jana; Becker, Felix; Borin, Dmitry Yu.; Stepanov, Gennady V.; Zimmermann, Klaus
Motion behaviour of magneto-sensitive elastomers controlled by an external magnetic field for sensor applications. - In: Journal of magnetism and magnetic materials, ISSN 1873-4766, Bd. 431 (2017), S. 262-265

The development of sensor systems with a complex adaptive regulation of the operating sensitivity and behaviour is an actual scientific and technical challenge. Smart materials like magneto-sensitive elastomers (MSE) are seen as one potential solution for this problem, since their mechanical properties may be controlled by external magnetic fields. The present paper deals with the investigation of elastic and damping properties of MSE containing magnetically soft particles under the influence of a uniform magnetic field. Based on the measurement of the first eigenfrequency of free bending vibrations of a fixed beam, the effective Young's modulus is evaluated theoretically and also numerically using Finite Element Method. It is shown that this parameter, as well as the first eigenfrequency of the beam, increases monotonically with the magnitude of the applied magnetic field. The results are aimed to develop an acceleration sensor with adaptive magnetically controllable sensitivity range for the detection of external mechanical stimuli of the environment.
Becker, Tatiana; Böhm, Valter; Naletova, Vera A.; Kaufhold, Tobias; Becker, Felix; Zeidis, Igor; Zimmermann, Klaus
A ferrofluid based artificial tactile sensor with magnetic field control. - In: Journal of magnetism and magnetic materials, ISSN 1873-4766, Bd. 431 (2017), S. 277-280

The paper deals with a tactile sensor inspired by biological hairs of mammals. The working principle is based on the effect of the magnetic force exerted on a paramagnetic body submerged into a ferrofluid volume under the influence of a nonuniform magnetic field. The deflection of the sensor's rod caused by external mechanical stimuli may be unambiguously identified by the distortion of the magnetic field, which occurs due to the motion of the attached body in the ferrofluid. The magnetic force acting on the body is evaluated experimentally and theoretically for the nonuniform magnetic field of a permanent magnet. The controlled oscillations of the rod are realised by applying a nonuniform magnetic field of perodically altering direction.
Issa, Mirna;
Einsatz funktioneller Materialien zur Realisierung inhärenter Sensorik bei elastischen Strukturen. - Ilmenau : Universitätsbibliothek, 2017. - 1 Online-Ressource (xv, 144 Seiten, 110.47 MB)
Technische Universität Ilmenau, Dissertation 2017

Sensorisierung der technischen Systeme hat in vielen Forschungsbereichen der Robotik zunehmend an Bedeutung gewonnen. Insbesondere für Mensch-Maschine-Schnittstellen sind sensorisierte und nachgiebige Systeme von Interesse. Die Nachgiebigkeit eines Systems kann zum Beispiel durch die Materialeigenschaften sowie durch die geometrische Gestaltung gewährleistet werden. In der vorliegenden Arbeit wird eine Möglichkeit zur Sensorisierung nachgiebiger Systeme, die für den Bereich der Robotik von Interesse sind, beschrieben. Dafür wird ein elektrisch leitfähiger Silikonkautschuk eingesetzt. Der Vorteil der Anwendung des leitfähigen Silikonkautschuks ist, dass die Nachgiebigkeit solcher Systeme weiterhin erhalten bleibt bzw. sich verbessert. Unter Nutzung experimenteller Untersuchungen von den leitfähigen Silikonkautschuken ELASTOSIL R 570/50 MH C1 und POWERSIL® 466 A/B VP konnte das elektrische Verhalten dieser Materialien unter den mechanischen Beanspruchungen charakterisiert werden. Die Einsatzmöglichkeiten des leitfähigen Silikonkautschuks als Sensorelemente werden am Beispiel von drei nachgiebigen Systemen aufgezeigt. Die hier verwendeten Sensorelemente beruhen auf dem Prinzip der elektrischen Widerstandsänderung unter den mechanischen Beanspruchungen. Das erste System ist eine taktile Struktur und hat eine einfache Gestalt. Mit dem ersten System wird die Anwendbarkeit von dem Material ELASTOSIL R 570/50 MH C1 als Sensorelement aufgezeigt. Verschiedene Tests werden an der taktilen Struktur zur Ermittlung der Kontaktstellen durchgeführt. Die Messergebnisse werden dargestellt und diskutiert. Bei dem zweiten System handelt es sich um einen nachgiebigen Greifer. Der Greifer kann sich an verschiedene Objekte beim Greifvorgang anpassen. Des Weiteren können durch die inhärente nachgiebige Sensorik Informationen über das gegriffene Objekt beim Greifvorgang geliefert werden. Im letzten Teil der Arbeit wird das dritte System, eine nachgiebige Gelenkverbindung mit inhärenter Sensorik, diskutiert. Die Sensorelemente des Systems können dank der Materialeigenschaften des Silikonkautschuks zusätzlich die Funktionen einer Feder und eines Dämpfers übernehmen. Dies ermöglicht einen kompakten Aufbau des Systems mit einer Steuerungsmöglichkeit der Drehrichtung mithilfe der gelieferten Sensorsignale bei einem Kollisionsfall.
Niederschuh, Sandra J.; Helbig, Thomas; Zimmermann, Klaus; Schmidt, Manuela; Witte, Hartmut
Kinematic response in limb and body posture to sensory feedback from carpal sinus hairs in the rat (Rattus norvegicus). - In: Zoology, ISSN 1873-2720, Bd. 121 (2017), S. 18-34

One of the most challenging adaptations within the therians has been to ensure dynamic stability of the trunk during rapid locomotion in highly structured environments. A reorganization of limb mechanics and development of new sensors has taken place within their stem lineage. Rats, which have a similar lifestyle to the first therians, possess sinus hairs specialized for tactile sensing. It is supposed that carpal sinus hairs have a role in sensing substrate properties and can thus induce adjustments in limb kinematics and body posture according to the different surface diameters and structures detected. This implies a shared sensorimotor control loop of sinus hairs and body posture. To investigate the role of the carpal sinus hairs during locomotion and to explore a possible interaction between limb and spine motion, spatiotemporal and kinematic parameters as well as the contact mechanics of the hairs with regard to the surface were quantified. Locomotion on a treadmill with continuous and discontinuous substrates was compared in the presence/absence of the carpal sinus hairs across a speed range from 0.2 m/s to 0.6 m/s. Recordings were taken synchronously using x-ray fluoroscopy and normal-light high-speed cameras. Our investigation revealed that the three tactile hairs made a triangle-like contact with the ground approximately 30 ms before touchdown of the forelimb. Within that time, it is likely that both the body posture and its oscillation are adjusted according to the different surface textures. The sensory input of the carpal sinus hairs induces a stabilization of the trajectory of the center of mass and, therefore, improves the dynamic stability of the trunk; conversely, the absence of the sensors results in a more crouched frontal body posture, similar to that seen in rats when they are moving in an unknown terrain. The carpal sinus hairs also sense the animal's speed during surface contact. This implicates an adjustment of the limb and spine kinematics, by increasing the speed-dependent effect or by increasing the distance between the trunk and the ground when the rat is walking faster.
Linß, Sebastian; Schorr, Philipp; Zentner, Lena
General design equations for the rotational stiffness, maximal angular deflection and rotational precision of various notch flexure hinges. - In: Mechanical sciences, ISSN 2191-916X, Bd. 8 (2017), 1, S. 29-49

Notch flexure hinges are often used as revolute joints in high-precise compliant mechanisms, but their contour-dependent deformation and motion behaviour is currently difficult to predict. This paper presents general design equations for the calculation of the rotational stiffness, maximal angular elastic deflection and rotational precision of various notch flexure hinges in dependence of the geometric hinge parameters. The novel equations are obtained on the basis of a non-linear analytical model for a moment and a transverse force loaded beam with a variable contour height. Four flexure hinge contours are investigated, the semi-circular, the corner-filleted, the elliptical, and the recently introduced bi-quadratic polynomial contour. Depending on the contour, the error of the calculated results is in the range of less than 2 % to less than 16 % for the suggested parameter range compared with the analytical solution. Finite elements method (FEM) and experimental results correlate well with the predictions based on the comparatively simple and concise design equations.
Zentner, Lena; Griebel, Stefan; Wystup, Clemens; Hügl, Silke; Rau, Thomas S.; Majdani, Omid
Synthesis process of a compliant fluidmechanical actuator for use as an adaptive electrode carrier for cochlear implants. - In: Mechanism and machine theory, Bd. 112 (2017), S. 155-171

The cochlear implant, consisting of an electrode carrier and embedded electrodes, is an auditory neuroprosthesis surgically inserted into the cochlea in order to create an auditory impression in deaf or profoundly hearing-impaired patients. This contribution presents a fluidically actuated electrode carrier with a changeable curvature to simplify insertion. Targeted deformation of the carrier is accomplished by applying pressure internally as well as using a non-stretchable thin fibre embedded in its wall. An analytical examination of the scaled model shows that enlarged geometrically similar systems can be studied in place of actual systems, reducing the effort required for measurements. The geometry of the electrode carrier was determined using model-based synthesis combining the finite element method with an analytical model. The material parameters for the finite element model were found experimentally and fitted by using a third-order Ogden material model. The result of the synthesis yielded a conical shape for the carrier. Synthesis of other forms is also possible and one form is shown which was calculated using a polynomial approach. Demonstrators (3:1-scale) were manufactured and measured. The difference between the measured and calculated pressures was less than 0.6 bar for the cylindrical form and less than 0.78 bar for the conical form.
Behn, Carsten; Schale, Florian; Zeidis, Igor; Zimmermann, Klaus; Bolotnik, Nikolai N.
Dynamics and motion control of a chain of particles on a rough surface. - In: Mechanical systems and signal processing, ISSN 1096-1216, Bd. 89 (2017), S. 3-13

In this paper the mechanics and control of the motion of a straight chain of three particles interconnected with kinematical constraints are investigated. The ground contact is described by dry (discontinuous) or viscous (continuous) friction. Here, we understand this model as a methodological basis for the design of worm-like locomotion systems, i.e., non-pedal mobile robots. This kind of robots will prove an efficient form of locomotion in application to inspection of pipes or for rescue missions. In this paper, a number of issues related to the dynamics and control of artificial limbless locomotion systems are discussed. Simplest models of a limbless locomotor are two-body or three-body systems that move along a horizontal straight line. In the first part of the paper, the controls are assumed in the form of periodic functions with zero average, shifted on a phase one concerning each other. Thus, there is a traveling wave along the chain of particles. In the second part, actuator models are discussed. It is supposed that there are unknown actuator data or the worm system parameter are not known or exactly as well. The focus is on adaptive control algorithms for the worm-like locomotion systems in order to track given reference trajectories, like kinematic gaits. Finally, a prototype together with its signal processing and control software is presented. Theoretically (analytically and numerically) calculated results of the dynamical behavior of the mobile system are compared to experimental data.
Pendzialek, Matthias; Schneider, Jürgen; Höhe, Kurt; Zentner, Lena
Miniaturization of check valves. - In: Microactuators and Micromechanisms, (2017), S. 15-26


... until 2022 from the Technical Mechanics Group

Results: 519
Created on: Wed, 17 Jul 2024 23:04:36 +0200 in 0.0656 sec

Zimmermann, Klaus; Zeidis, Igor; Pivovarov, Mikhail
Rectilinear motion of a two-mass point system in a resistive medium. - In: 23rd International Congress of Theoretical and Applied Mechanics, 2012, SM16-030, insges. 2 S.

Zimmermann, Klaus; Zeidis, Igor; Naletova, Vera A.; Kalmykov, Sergej A.; Turkov, Vladimir A.
Model of a thin rod with viscoelastic magnetizable material in the alternating magnetic field. - In: Solid state phenomena, ISSN 1662-9779, Bd. 190 (2012), S. 629-632
Behn, Carsten; Loepelmann, Peter
Adaptive versus fuzzy control of uncertain mechanical systems. - In: International journal of applied mechanics, ISSN 1758-826X, Bd. 4.2012, 2, 1250019, insges. 28 S.

The motivation of this work is formed by the biological behavior of a receptor cell (sensory system). It is modeled as a spring-mass-damper oscillator with a spatial disturbance signal acting on the frame and an inner active element that generates a force acting on the mass. Both the system parameters and the excitation signal are supposed to be unknown. The goal is to achieve a predefined movement of the mass, such as tracking a set point trajectory or stabilization. Thus, a controller is required to act on the system using the control force as input in such a way that the desired behavior is generated. This is done by means of high-gain-stabilization. Like its biological paradigm, the receptor is in a permanent state of adaption. This means that recurring disturbances, such as wind acting on the vibrissa, are damped in order to achieve lambda-stabilization. To achieve this control goal and at the same time deal with unknown systems, adaptive controllers are introduced. These adaptive control strategies are compared with an adaptive fuzzy approach.
Chigarev, Anatoli V.; Zimmermann, Klaus; Minchenya, Vladimir; Becker, Felix
Automatic stabilization of the translational motion of a microrobot. - Ilmenau : ilmedia. - Online-Ressource (PDF-Datei: 6 S., 301 KB)Publ. entstand im Rahmen der Veranst.: 56th IWK, International Scientific Colloquium, Ilmenau University of Technology, 12 - 16 September 2011 / Faculty of Mechanical Engineering, Ilmenau University of Technology

The analog motion control of a microrobot with feedback requires a more complicated structure due to the corresponding sensors, microprocessors and actuators. Application of the digital control system allows the use of a control algorithm, such as the autopilot, without feedback, which allows us to simplify the system. We consider the stabilization of the motion of the microrobot on a horizontal surface along the given motion trajectory. Minimization of the deviation angle of the robots axis from the tangent to the motion trajectory is a criterion for quality control and can be implemented by the digital device with a hysteresis characteristic.
Lysenko, Victor; Zimmermann, Klaus; Chigarev, Anatoli V.; Becker, Felix
A mobile vibro-robot for locomotion through pipelines. - Ilmenau : ilmedia. - Online-Ressource (PDF-Datei: 4 S., 1,01 MB)Publ. entstand im Rahmen der Veranst.: 56th IWK, International Scientific Colloquium, Ilmenau University of Technology, 12 - 16 September 2011 / Faculty of Mechanical Engineering, Ilmenau University of Technology

The subject of our work is the creation of different designs of mobile robots for the movement through pipelines and similar technical systems. Using the transversal vibrations of an elastic bristle body, allows us to develop a new crawling vibro-robot. The motion is mainly realized by anisotropic friction forces. For the design process, we use the well-known construction principle of combination of alternative systems. It enables the transfer of structural characteristics (i.e. its kinematics) from one object to another, leading to new desirable characteristics or optimisations of existing technical objects. An analytical model of the motion of the bristles is presented.
Stepanenko, Dmitry A.; Minchenya, Vladimir T.; Asimov, R. M.; Zimmermann, Klaus
Possibility of application of small-size robots with vibratory piezoelectric actuators for inspection of physical state of surfaces. - In: AIP conference proceedings, ISSN 1551-7616, Bd. 1433 (2012), S. 685-688
Alt, Wolfgang; Böhm, Valter; Kaufhold, Tobias; Lobutova, Elka; Resagk, Christian; Voges, Danja; Zimmermann, Klaus
Theoretical and experimental investigations of amoeboid movement and first steps of technical realisation. - In: Nature-inspired fluid mechanics, (2012), S. 3-23

Steigenberger, Joachim; Behn, Carsten;
Worm-like locomotion systems : an intermediate theoretical approach. - München : Oldenbourg, 2012. - XII, 195 S. ISBN 3-486-71304-3
Literaturverz. S. [187] - 190

The book in hand grew out of the authors' current research and their long-continued experience in teaching mathematics and mechanics. In a wide sense, it aims at mathematical modeling of mechanical objects and their exploitation. This is done in a bit unconventional way by concentrating on the special object class worm-like locomotion systems and in proceeding with no use of recent sophisticated mathematical tools which most likely cannot be handled by freshmen in engineering or mathematics. Nevertheless, this does not harm the stringent line the physical object to the analytical interpretation of the final mathematical model. The basic model spiked worm in a straight line enables the authors to come up with a fairly self-contained theory which then allows one to study effects of friction and control. The considered system class has its importance in practice (motion in narrow canals, e.g.), but this book is not with an orientation to design and application, the theory developed here should rather be seen as a contribution to bionics.

Voges, Danja; Carl, Kathrin; Klauer, Gertrud J.; Uhlig, René; Schilling, Cornelius; Behn, Carsten; Witte, Hartmut
Structural characterization of the whisker system of the rat. - In: IEEE sensors journal, ISSN 1558-1748, Bd. 12 (2012), 2, S. 332-339
Naletova, Vera A.; Turkov, Vladimir A.; Pelevina, Daria A.; Rozin, Alexander V.; Zimmermann, Klaus; Popp, Jana; Zeidis, Igor
Behavior of a free surface of a magnetic fluid containing a magnetizable cylinder. - In: Journal of magnetism and magnetic materials, ISSN 1873-4766, Bd. 324 (2012), 6, S. 1253-1257