On-off nonlinear active control of floor vibrations
On-off nonlinear active control of floor vibrations
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DOI：
10.1016/j.ymssp.2010.02.011
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发表时间：
2010-08
影响因子：
8.4
通讯作者：
I. M. Díaz;P. Reynolds
中科院分区：
文献类型：
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作者：
I. M. Díaz;P. Reynolds
通过电磁敏感质量致动器的主动控制，可以减轻人引起的地板振动。以前的研究人员已经开发了一个系统，地板振动包括线速度反馈控制（LVFC）的命令限制器（饱和的命令信号，以避免致动器过载）。该控制的性能高度依赖于所使用的线性增益，该线性增益必须针对特定激励而设计，并且对于其他激励可能不是最佳的。这项工作探讨了使用开关非线性速度反馈控制（NLVFC）作为LVFC的自然演变时，高增益和/或显着的振动水平，以及饱和的控制律。首先，利用描述函数工具分析了（1）饱和LVFC、（2）带死区的on-off NLVFC和（3）带开关函数的on-off NLVFC的稳定性。特别强调的是支付给所产生的极限环行为和设计适当的死区和关闭水平，以避免它。其次，实验室试验，使用三个控制律进行实验室测试地板上。结果证实了分析的稳定性预测。开-关NLVFC的优点是无需选择增益，并且可以提供最大的致动器能量来消除振动。相反，选择死区或切断功能的要求在其应用中提供了缺点。
Human-induced floor vibrations can be mitigated by means of active control via an electromagnetic proof-mass actuator. Previous researchers have developed a system for floor vibration comprising linear velocity feedback control (LVFC) with a command limiter (saturation in the command signal to avoid actuator overloading). The performance of this control is highly dependent on the linear gain utilised, which has to be designed for a particular excitation and might not be optimum for other excitations. This work explores the use of on-off nonlinear velocity feedback control (NLVFC) as the natural evolution of LVFC when high gains and/or significant vibration level are present together with saturation in the control law. Firstly, the describing function tool is employed to analyse the stability properties of: (1) LVFC with saturation, (2) on-off NLVFC with a dead zone and (3) on-off NLVFC with a switching-off function. Particular emphasis is paid to the resulting limit cycle behaviour and the design of appropriate dead zone and switching-off levels to avoid it. Secondly, experimental trials using the three control laws are conducted on a laboratory test floor. The results corroborate the analytical stability predictions. The pros of on-off NLVFC are that no gain has to be chosen and maximum actuator energy is delivered to cancel the vibration. In contrast, the requirement to select a dead zone or switching-off function provides a drawback in its application.