Atalante – Active piezoelectric bearing with rotating actuators

旋转机械构成了技术世界的中坚力量。它们几乎可以在所有领域找到，如泵、喷气发动机和电动马达。然而，旋转部件经常受到不平衡的影响，在运行过程中会产生谐振力激励，从而可能造成噪音和损坏。为了抵消这一点，转子通过增加或移除质量来平衡。如果在运行过程中可达到的平衡质量不充分或不平衡发生变化，可在运行过程中采取主动措施进行在线平衡。这一研究领域最新的主动平衡装置是一种带有旋转压电致动器的主动轴承。它的功能已经在实验室测试中得到了验证，与传统的压电式轴承相比，功耗降低了99%。然而，在实验中也出现了一些无法解释的副作用，如三个旋转的执行器导致转子在主动运行过程中产生强烈的三阶振动和静态位移。本提案中提出的研究项目调查了在负载路径内带有旋转压电致动器的主动轴承的基本原理。该项目的目的是解释和描述发生的转子动态效应，并研究轴承在其他应用中的潜力，例如齿轮箱的能量收集和主动振动控制。为此，必须对包括电气和机械滞后等非线性效应的主动轴承进行建模，并在试验台上进行实验以进行验证。然后，模型将被用来模拟副作用，并将洞察力转移到具有更多致动器和不同使用的压电材料的主动轴承上。该样机将首先用于主动平衡。对于这项任务，必须实施和验证无模型控制。此外，还将研究由恒定载荷(例如由于重力)引起的执行器变形可以产生多少能量，以及在此过程中会发生哪些动态副作用。此外，还将研究一种通过电荷倒置进行半主动控制的方法，以产生可能用于主动减振的交变作用力。最后，将收集所有结果，以便分析和评估带有旋转压电致动器的主动轴承在主动平衡、主动减振、健康监测和能量收集方面的潜力。

Rotating machines form the backbone of the technical world. They can be found in almost all areas such as pumps, jet engines and electric motors. However, rotating components are always subject to unbalance which causes a harmonic force excitation during operation and can thereby cause noise and damage. To counteract this, rotors are balanced by adding or removing mass. If the achievable balancing quality is not sufficient or the unbalance changes during operation, active measures can be used for online balancing during operation. The latest active balancing device in this research area is an active bearing with rotating piezo actuators. Its functionality has already been demonstrated in laboratory tests, with a 99% reduction in power consumption compared to conventional piezo bearings. However, unexplained side effects occur in the experiments, such as strong third-order vibrations and static displacements of the rotor during an active operation, which are caused by the three rotating actuators. The research project presented in this proposal investigates the fundamentals of an active bearing with rotating piezo actuators within the load path. The aim of the project is to explain and describe the rotor dynamic effects that occur and to investigate the potential of the bearing for other applications, such as energy harvesting and active vibration control of gearboxes. For this purpose, the active bearing, including non-linear effects such as electrical and mechanical hysteresis, has to be modelled which is accompanied by experiments on a test bench for validation. The model will then be used to simulate the side effects and transfer the insights to an active bearing with more actuators and different used piezo material. The prototype will be first used for active balancing. A model-free control has to be implemented and validated for this task. Furthermore, it will be investigated how much energy can be generated from the deformation of the actuators caused by constant loads, for example due to the gravitational force, and which dynamic side effects occur during the process. In addition, a semi-active control by means of charge inversion will be investigated in order to generate alternating forces, which can potentially be used for active vibration reduction. Finally, all results will be gathered in order to analyse and evaluate the potential of an active bearing with rotating piezo actuators in terms of active balancing, active vibration reduction, health monitoring and energy harvesting.