Browsing by Author "Neubauer, Michael"

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Open Access
Experimental investigation into the implications of transmission errors for rack-and-pinion drives
(2021) Steinle, Lukas; Lechler, Armin; Neubauer, Michael; Verl, Alexander
Rack-and-pinion drives are the preferred option in the machine tool sector when long ranges of motion and high loads are involved. However, their shortcomings particularly include deficiencies in the achievable positioning and path accuracy. The backlash as one of the main issues is well described in the literature and numerous solutions to reduce its negative effects exist. In contrast, there is a lack of literature regarding the scientific and systematic analysis of the transmission errors in rack-and-pinion drives. In this paper, the displacements originating in the drive train of a system with industrial components are measured under different operating conditions. The observed transmission errors are thoroughly analyzed in no-load operation and their sources are discussed. Subsequent investigations show significant load-dependent alterations of the transmission errors and direction-dependent characteristics, the causes of which are explained. It is shown, that transmission errors negatively affect the path accuracy of position controlled drives, which is amplified by excitation of the machine structure in certain operating conditions. To address this issue, different error compensation concepts are presented.
Open Access
Hybrid manufacturing of topology optimized machine tool parts through a layer laminated manufacturing method : practical validation using the example of a bearing block
(2021) Helfesrieder, Nico; Neubauer, Michael; Lechler, Armin; Verl, Alexander
Load-oriented lightweight structures are commonly designed based on topology optimization. For machine tool parts, they enable the reduction of moving masses and therefore increase the resource and energy efficiency of production systems. However, this usually results in complex part structures that are difficult or impossible to produce using conventional manufacturing methods. In this paper, a hybrid layer laminated manufacturing (LLM) method is proposed enabling manufacturing of topology-optimized machine tool parts. The method is referred to as hybrid, as the subtractive structuring of metal sheets is combined with the additive joining of the sheets by adhesive bonding. This enables enclosed inner cavities without support structures, which are used to approximate the optimal density distribution from a topology optimization via manufacturing. The proposed LLM method is validated on the basis of a bearing block of a ball screw feed drive. A experimental study in the time and frequency domain on a test rig confirms the principle suitability of the LLM method for the production of industrial applicable lightweight components.
Open Access
Verbesserung der dynamischen Bahngenauigkeit kaskadiert geregelter Knickarmroboter durch semiaktive Gelenkdämpfung
(Stuttgart : Fraunhofer Verlag, 2025) Neubauer, Michael; Verl, Alexander (Prof. Dr.-Ing. Dr. h.c. mult.)
Die dynamische Bahngenauigkeit von Industrierobotern steht seit Jahrzehnten im Fokus kontinuierlicher Entwicklungsaktivitäten. Einen wesentlichen Einfluss haben die elastischen Antriebsstränge, deren gekoppelte Dynamik aus Antriebsregelung und Getriebemechanik zu genauigkeitsmindernden Schleppfehlern führt. Ein vielversprechender Lösungsansatz ist die semiaktive Dämpfung, die durch selektive Bremseingriffe eines Zusatzaktuators die Getriebemechanik dämpft. Daraus resultiert ein robusteres Regelstreckenverhalten, das eine performantere Auslegung der Antriebsregelung ermöglicht, wodurch die dynamische Bahngenauigkeit steigt. Diese Arbeit untersucht die Eignung der semiaktiven Dämpfung für kaskadiert geregelte Knickarmroboter. Dazu wird eine hochdynamische Scheibenbremse entwickelt und ein Regelgesetz zur bedarfsgerechten Ansteuerung eingeführt. Zur Regelungsparametrierung werden aus einem H∞-Entwurf inbetriebnahmegerechte Einstellregeln abgeleitet. Trajektorienfolge- und Fräsversuche belegen die Wirksamkeit der entwickelten Gesamtlösung. Abschließend werden Potenziale und Grenzen diskutiert, mit dem Fazit einer breiten Einsetzbarkeit in unterschiedlichen Anwendungen.