Semi-Active Vibration Control Based on Switched Piezoelectric Transducers

The semi-active synchronized switch damping (SSD) approach has been widely used in vibration suppression owing to its many advantages compared with the active and passive approaches. The SSD method is realized by switching the voltage on the piezoelectric patch embedded in the structure, synchronically with the vibration of the mode to be controlled. Although good control performance can be obtained in the targeted mode, vibrations of highorder harmonic frequencies are usually excited due to the rectangular waveform of the switched actuator voltage because of infinitesimal inversion time, as observed in the previous experiments. This drawback of the SSD method has greatly hindered its application in practical engineering structures. In order to overcome this drawback, the authors propose a new method in this study to suppress the high-order harmonic components in the switched voltage by increasing the inversion time of the voltage. The theoretical expressions of the switched voltage and the dynamic response of the structure were formulated for the cases with finite voltage inversion time. The theoretical results show that increasing the inversion time may weaken the vibration control effect of the targeted mode, but it can significantly reduce the excitation force of the highorder harmonic components. When the inversion time is half of the period of the targeted mode, all the high-order harmonic components in the actuator voltage are completely erased and the control force of the targeted mode decreases by 21%. An experimental setup of a flexible beam was used to verify the theoretical results of the switched voltage and control performance under different inversion time.

Section: The Voltage ( )mentioning

confidence: 99%

Superharmonic vibration and its reduction in SSD control by increase of voltage inversion time

Tan

Qiu

et al. 2018

“…(25) The time window is (0, T ], in which T = t n = nτ sw . Substitution of t k in equation (25) into equation (16) gives…”

Section: Influence Of Switching Frequency On Control Performancementioning

confidence: 99%

“…It means that the optimal switching frequency is twice that of the vibration to be controlled and the optimal switching phase is 0 • from the displacement extrema. Experimental results showed that the control performance can deteriorate significantly if a delay is induced in the electronic circuit of voltage inversion [16].…”

Section: Introductionmentioning

confidence: 99%

The influence of switching phase and frequency of voltage on the vibration damping effect in a piezoelectric actuator

Qiu

Xia

et al. 2010

In a structural system with piezoelectric actuators, a damping effect can be achieved by properly switching the voltage on the actuators. Switched voltage methods based on piezoelectric actuators, including active bang-bang control and semi-active synchronized switch damping methods, have become an important category of vibration damping approach. Since the switching phase and switching frequency are critical factors to damping performance, their influence on converted energy in a piezoelectric actuator is investigated under the condition that the switched voltage is constant. The converted energy with randomly switched voltage is also investigated theoretically and numerically. Finally an example of beam vibration with synchronized switch damping on inductor (SSDI) control and synchronized switch damping on voltage source (SSDV) control is used to illustrate how the switching frequency can affect the control performance of different modes in a multiple-degree-of-freedom system.

“…Energy conversion can deteriorate drastically when the number and phase of the switching actions are changed from the optimal state. For example, the converted energy may become zero when the number of switching actions is one or four, or when the switching action is delayed by a phase between π/2 and 3π/2 [13]. Hence a control strategy to maximize the efficiency of energy conversion is the most important issue in multi-mode vibration control.…”

Section: Switching Strategy Based On An Amplitude Thresholdmentioning

confidence: 99%

Multi-modal vibration control using a synchronized switch based on a displacement switching threshold

Ji¹,

Qiu²,

Zhu³

et al. 2009

A new semi-active method for multi-mode vibration control using the nonlinear synchronized switch damping (SSD) approach based on a displacement switching threshold is proposed in this paper. Several extensions of the SSD approach, including SSDI (SSD on inductance), SSDV (SSD on a voltage source), enhanced SSDV, and adaptive SSDV, have been developed to improve the control of the single-mode vibration, but the weakness of the SSD approach for multi-modal vibration control has not been solved. In all these extensions of the SSD approach, the switch is controlled by the same algorithm, that is, it reverses the voltage of the piezoelectric element at all extrema of displacement. This switching algorithm is effective in single-mode control, but it leads to over-frequent switching in multi-mode control. In the method proposed in this study, an improved switching algorithm based on a displacement threshold, which prevents the switch in the shunt circuit from over-frequent on-and-off actions and accordingly increases the converted energy to improve the control performance, is proposed. The switching algorithm is applied to an SSDI system and used in the vibration damping of a beam with two excited modes. Compared to the classical SSDI approach, the control performance of the first mode is improved from 3.7 to 18.2 dB, but that of the second mode is slightly worse, having changed from 3.46 to 2.6.