Dynamics and Realization of a Feedback-Controlled Nonlinear Isolator With Variable Time Delay
Dynamics and Realization of a Feedback-Controlled Nonlinear Isolator With Variable Time Delay
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DOI：
10.1115/1.4041369
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发表时间：
2018-10
期刊：
影响因子：
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通讯作者：
Xiuting Sun;Feng Wang;Jian Xu
中科院分区：
文献类型：
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作者：
Xiuting Sun;Feng Wang;Jian Xu
将时滞反馈控制引入非线性隔振器(NL-VI)，对其隔振效果进行了理论和实验研究。在反馈控制回路中，考虑了恒时滞和变时滞的复合控制。首先，进行了稳定性分析，确定了无励磁稳定零平衡的控制参数范围。其次，用多尺度法研究了TD-FB控制的非线性共振频率和非线性振动衰减，论证了TD-FB控制的机理。非线性振动性能分析结果表明，大变时滞可以改善系统的减振效果。此外，延时的机理不仅在于调节等效的刚度和阻尼值，还在于在高频下产生有效的隔离带隙。因此，假设可变时延是频率的函数，以满足不同频段的不同要求。相关实验验证了所设计的可变时延对不同频段隔振性能的改善。由于复合时滞反馈控制改善了非线性系统的隔振性能，可应用于船舶、航空航天柔性结构等领域。
In this paper, time-delayed feedback (TD-FB) control is introduced for a nonlinear vibration isolator (NL-VI), and the isolation effectiveness features are investigated theoretically and experimentally. In the feedback control loop, compound control with constant and variable time delays is considered. First, a stability analysis is conducted to determine the range of control parameters for stable zero equilibrium without excitation. Next, the nonlinear resonance frequency and the nonlinear vibration attenuation are studied by the method of multiple scales (MMS) to demonstrate the mechanism of TD-FB control. The results of the nonlinear vibration performances show that large variable time delays can improve the vibration suppression. Additionally, the mechanism for the time delay is not only to tune the equivalent stiffness and damping but also to induce effective isolation bandgap at high frequency. Therefore, the variable time delay is assumed as the function of frequency to meet different requirements at different frequency bands. The relevant experiment verifies the improvement of designed variable time delay on isolation performances in different frequency bands. Due to the improvement of isolation performances by compound time delay feedback control on nonlinear systems, it can be applied in the fields of ships, flexible structure in aerospace and aviation.