{"year":"2025","citation":{"ieee":"W. Littmann, P. Bornmann, T. Hemsel, and C. Scheidemann, “Power ultrasonic actuators with suddenly changing loads: How to control the amplitudes in resonance,  antiresonance, or in-between,” presented at the International Conference on Ultrasonics (ICU), Paderborn, Germany, 2025.","chicago":"Littmann, Walter, Peter Bornmann, Tobias Hemsel, and Claus Scheidemann. “Power Ultrasonic Actuators with Suddenly Changing Loads: How to Control the Amplitudes in Resonance,  Antiresonance, or in-Between,” 2025.","apa":"Littmann, W., Bornmann, P., Hemsel, T., &#38; Scheidemann, C. (2025). <i>Power ultrasonic actuators with suddenly changing loads: How to control the amplitudes in resonance,  antiresonance, or in-between</i>. International Conference on Ultrasonics (ICU), Paderborn, Germany.","ama":"Littmann W, Bornmann P, Hemsel T, Scheidemann C. Power ultrasonic actuators with suddenly changing loads: How to control the amplitudes in resonance,  antiresonance, or in-between. In: ; 2025.","mla":"Littmann, Walter, et al. <i>Power Ultrasonic Actuators with Suddenly Changing Loads: How to Control the Amplitudes in Resonance,  Antiresonance, or in-Between</i>. 2025.","bibtex":"@inproceedings{Littmann_Bornmann_Hemsel_Scheidemann_2025, title={Power ultrasonic actuators with suddenly changing loads: How to control the amplitudes in resonance,  antiresonance, or in-between}, author={Littmann, Walter and Bornmann, Peter and Hemsel, Tobias and Scheidemann, Claus}, year={2025} }","short":"W. Littmann, P. Bornmann, T. Hemsel, C. Scheidemann, in: 2025."},"title":"Power ultrasonic actuators with suddenly changing loads: How to control the amplitudes in resonance,  antiresonance, or in-between","conference":{"end_date":"2025-09-25","location":"Paderborn, Germany","name":"International Conference on Ultrasonics (ICU)","start_date":"2025-09-21"},"date_updated":"2026-03-02T11:39:50Z","author":[{"first_name":"Walter","full_name":"Littmann, Walter","last_name":"Littmann"},{"last_name":"Bornmann","full_name":"Bornmann, Peter","first_name":"Peter"},{"id":"210","full_name":"Hemsel, Tobias","last_name":"Hemsel","first_name":"Tobias"},{"last_name":"Scheidemann","full_name":"Scheidemann, Claus","id":"38259","first_name":"Claus"}],"date_created":"2026-03-02T11:19:46Z","abstract":[{"text":"Power ultrasonic actuators are used in various industrial, automotive and medical applications. Examples are ultrasonic welding of plastics or metal, surgery processes like cutting of tissue or bone, and the excitation of cavitation in liquids for ultrasonic cleaning. From a physical point of view, many of these processes are characterised by non-constant damping conditions for the ultrasonic actuators, since the systems need to be driven in unloaded as well as in high-loaded states. To get high power output, the piezoelectric actuators are usually driven in or near resonance at precisely defined vibration amplitudes. This is a quite complicated task  especially if cost or mass optimized PZT transducers are used or if lead-free piezoelectric ceramics are applied to replace lead-containing materials. In particular the sudden change between loading states is very challenging for electronic excitation and control. The present contribution gives insight into typical problems that may arise in context with sudden load-changes during operation, e.g. uncontrolled jumps in voltage and velocity amplitudes. Measurements on ultrasonic power actuators being abruptly immersed into water at high amplitude are discussed for illustration. Observations during spontaneous load-changes are explained, and it is shown that several problems may be defused by driving the actuators in antiresonance or using a particular driving point in-between resonance and antiresonance (“falling edge control”). The different control strategies are investigated always using just one single hardware.","lang":"eng"}],"status":"public","type":"conference","language":[{"iso":"eng"}],"_id":"64802","department":[{"_id":"151"}],"user_id":"210"}