Parametric study on the optimal tuning of an inertial actuator for vibration control of a plate: Theory and experiments
Parametric study on the optimal tuning of an inertial actuator for vibration control of a plate: Theory and experiments
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DOI：
10.1016/j.jsv.2018.07.048
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发表时间：
2018-11
影响因子：
4.7
通讯作者：
S. Camperi;M. G. Tehrani;S. Elliott
中科院分区：
文献类型：
--
作者：
S. Camperi;M. G. Tehrani;S. Elliott
本文提出了用惯性作动器对平板速度反馈增益进行理论和实验调谐的方法。这项研究的目的是分析一种直接的速度反馈控制单元，它可以在局部调整的同时提供全局的减振。这是通过速度信号和执行器动力学的知识来实现的，而没有关于板动力学的信息。在实践中，电输入提供给执行器，与结构的局部速度成正比，以这种方式产生主动阻尼。调谐是通过最大化惯性致动器从结构中吸收的功率来实现的，这表明相当于通过结构的动能估计的全局振动水平的最小化。使用了9个加速度计，研究了不同反馈增益值下加速度计的性能。此外，还考虑了积分频率范围对速度反馈增益调谐的影响，实验发现，与数值模型预期的一样，可以实现高达5 dB的宽带降低。当实施反馈控制时，控制单元从板吸收的功率在惯性致动器的第一固有频率以下为负。这是由于这样一个事实，尽管配置了速度反馈，但由于执行器的动力学，控制系统仅是有条件稳定的。当增益低于最优增益时，主动控制的性能会急剧下降。为此，对板-作动器副进行了参数化研究，研究了板和惯性作动器动态特性的影响。发现主动控制的有效性取决于驱动器与板之间的质量比。特别是，对于低质量比，系统很好地接近理想情况，在这种情况下，控制力与板的速度成正比，但对于高质量比，可以引入少量的主动阻尼。
This paper presents a theoretical and experimental tuning of the velocity feedback gain of a plate with an inertial actuator. The objective of the study is to analyse a direct velocity feedback control unit, which can be tuned locally and yet providing a global vibration reduction. This is achieved through the knowledge of the velocity signal and the actuator dynamics, without information on the plate dynamics. In practice, an electrical input is provided to the actuator, proportional to the local velocity of the structure, in such a way to generate active damping. The tuning is performed by maximising the power absorbed by the inertial actuator from the structure, and this is shown to be equivalent to the minimisation of the global level of vibration, estimated through the kinetic energy of the structure. Nine accelerometers have been used, and the performance for several values of different feedback gains has been investigated. Moreover, the influence of the frequency range of integration in the tuning of the velocity feedback gain is considered, and it is found experimentally that a broadband reduction up to 5 dB can be achieved, as expected from the numerical model. The absorbed power from the plate by the control unit is found to be negative below the first natural frequency of the inertial actuator, when the feedback control is implemented. This is due to the fact that, although a collocated velocity feedback is implemented, the control system is only conditionally stable because of the actuator dynamics. The performance of active control is found to reduce dramatically, if instability occurs for gains lower than the optimal one. For this reason, the work is enriched with a parametric study on the plate-actuator pair, in which the influence of the dynamic properties of the plate and the inertial actuator are investigated. The effectiveness of the active control is found to depend on the mass ratio between the actuator and the plate. In particular, for low mass ratios, the system well approximate the ideal case, in which a control force is proportional to the velocity of the plate, but for high mass ratios, a small amount of active damping can be introduced.