TY - JOUR AB - With enhancing digitalization, condition monitoring is used in an increasing number of application fields across various industrial sectors. By its application, increased reliability as well as reduced risks and costs can be achieved. Based on different approaches, technical systems are monitored and measured data is analyzed to enable condition-based or predictive maintenance. To this end, machine learning approaches are usually implemented to diagnose the health states or predict the health index of the monitored system. However, these trained models are often black-box models, not intuitively explainable for a human. To overcome this shortcoming, a model-based approach based on physics is developed for piezoelectric bending actuators. Such a model enables a transparent representation of the system. Moreover, the model-based approach is extended by a parameter-estimation to account for sudden changes in behavior e. g. caused by occurring cracks. AU - Bender, Amelie ID - 44672 JF - Sensors and Actuators A: Physical KW - Condition Monitoring KW - Model-based approach Diagnostics KW - Varying conditions KW - Explainability KW - Piezoelectric bending actuators SN - 0924-4247 TI - Model-based condition monitoring of piezoelectric bending actuators VL - 357 ER - TY - CONF AB - Piezoelectric inertia motors use the inertia of a body to drive it by means of a friction contact in a series of small steps. These motors can operate in ``stick-slip'' or ``slip-slip'' mode, with the fundamental frequency of the driving signal ranging from several Hertz to more than 100 kHz. To predict the motor characteristics, a Coulomb friction model is sufficient in many cases, but numerical simulation requires microscopic time steps. This contribution proposes a much faster simulation technique using one evaluation per period of the excitation signal. The proposed technique produces results very close to those of timestep simulation for ultrasonics inertia motors and allows direct determination of the steady-state velocity of an inertia motor from the motion profile of the driving part. Thus it is a useful simulation technique which can be applied in both analysis and design of inertia motors, especially for parameter studies and optimisation. AU - Hunstig, Matthias AU - Hemsel, Tobias AU - Sextro, Walter ID - 9784 KW - friction KW - ultrasonic motors KW - Coulomb friction model KW - efficient simulation technique KW - friction contact KW - high-frequency piezoelectric inertia motor KW - motor characteristics prediction KW - numerical simulation KW - slip-slip mode KW - stick-slip mode KW - time-step simulation KW - ultrasonic inertia motor KW - Acceleration KW - Acoustics KW - Actuators KW - Computational modeling KW - Friction KW - Numerical models KW - Steady-state SN - 1948-5719 T2 - Ultrasonics Symposium (IUS), 2012 IEEE International TI - An efficient simulation technique for high-frequency piezoelectric inertia motors ER - TY - JOUR AB - The paper presents the results of numerical and experimental investigation of cylindrical piezoelectric actuator used for achieving independent three degrees of freedom oscillations of the contact point. The design of actuator based on a hollow piezoelectric cylinder mounted on a metal rod. The piezoceramic cylinder has a radial polarization and special configuration of the electrodes that cover inner and outer surface of the cylinder. The main advantage of actuator's design is that solid metallic rod operates as a part of inner electrode of the cylinder and a stator of actuator. The geometry of piezoelectric actuator was adopted to reach resonance of oscillations for the first longitudinal mode and the third flexural mode at same frequency. The actuator is designed to move positioned object through contact point which is located on the top of the rod. The optimal topology of electrodes was found to achieve longitudinal and flexural oscillations of the actuator in two perpendicular planes. Three degrees of freedom of the positioning object can be achieved and control of the system can be implemented by applying different excitation schemes and regimes. The numerical simulation and experimental study of piezoelectric actuator was performed. Impedance of actuator was analyzed under different excitation regimes. The results of numerical modeling and experimental study were compared. Recommendations for the further development of this type of actuator are given. AU - Lucinskis, Raimundas AU - Mazeika, Dalius AU - Hemsel, Tobias AU - Bansevicius, Ramutis ID - 9767 IS - 1 JF - AIP Conference Proceedings KW - dielectric polarisation KW - piezoceramics KW - piezoelectric actuators TI - Multi-DOF cylindrical piezoelectric actuator with radial polarization VL - 1433 ER - TY - CONF AB - EN: Although the use of new actuator technologies is quite enthusiastic, the realization of innovative systems based on these principles fails because of doubts in dependability. Until now, new working principles for actuators have not been systematically investigated in the means of dependability. Therefore we developed a proceeding for a dependability-oriented evaluation of technologies. This is shown in the case of shape memory alloy actuators. DE: Die Realisierung von Systemen mittels innovativer Aktortechnologien scheitert oftmals an der Skepsis gegenüber der Verlässlichkeit (Vertrauen in die zuverlässige und sichere Funktionalität der Technologie). Diese liegt darin begründet, dass neue Aktortechnologien bzw. die Integration von innovativen physikalischen Wirkprinzipen innerhalb neuer Aktorkonzepte bisher noch nicht systematisch im Kontext der Verlässlichkeit untersucht werden. Daher haben wir ein Vorgehen zur verlässlichkeitsorientierten Technologiebewertung entwickelt. Neben der detaillierten Darstellung des Vorgehensmodells wird es exemplarisch anhand von Formgedächtnislegierungen zur Entwicklung innovativer Antriebslösungen angewendet. AU - Müller, Thomas AU - Schiedeck, Florian AU - Hemsel, Tobias ID - 9570 KW - EN: Dependability KW - Reliability KW - Evaluation of Technology KW - Actuators KW - Shape Memory Alloys DE: Verl{\ T2 - 2. Tagung des DVM -- Arbeitskreis Zuverlässigkeit mechatronischer und adaptronischer Systeme: Absicherung der Systemzuverlässigkeit, Koblenz TI - Verlässlichkeitorientierte Technologiebewertung innovativer Aktortechnologien am Beispiel von Formgedächtnislegierungen ER - TY - CONF AB - In neurosurgery, delineation of tumor boundaries during resection of brain tumors is of substantial relevance. During operation distinction between tumor and healthy tissue rely on the abilities of the surgeon based on visual and tactile differentiation. In this paper a high sensitivity actuator-sensor system using a piezoelectric bimorph is presented. Frequency shift and transfer function of the bimorphpsilas voltages are detected and evaluated. Sensorpsilas sensitivity is evaluated using two frequency controls strategies: A phase-locked loop (PLL) and a self-oscillating circuit. Results of measurements conducted on gel-phantoms are presented and discussed. AU - Uribe, David Oliva AU - Stroop, Ralf AU - Hemsel, Tobias AU - Wallaschek, Jörg ID - 9576 KW - biomedical measurement KW - brain KW - cancer KW - neurophysiology KW - phantoms KW - phase locked loops KW - piezoelectric actuators KW - surgery KW - tactile sensors KW - transfer functions KW - tumours KW - PLL KW - biomedical tissue differentiation system KW - brain tumor resection KW - frequency control KW - frequency shift KW - gel-phantom KW - high sensitivity actuator-sensor system KW - neurosurgery KW - phase-locked loop KW - piezoelectric actuators KW - piezoelectric bimorph KW - self-oscillating circuit KW - sensor sensitivity KW - tactile differentiation KW - tactile sensor system KW - transfer function KW - tumor boundary KW - visual differentiation KW - Biomedical measurements KW - Circuits KW - Frequency control KW - Neoplasms KW - Neurosurgery KW - Phase locked loops KW - Piezoelectric actuators KW - Surges KW - Transfer functions KW - Voltage SN - 1075-6787 T2 - Frequency Control Symposium, 2008 IEEE International TI - Development of a biomedical tissue differentiation system using piezoelectric actuators ER -