Optimal and robust modal control of a flexible structure using an active dynamic vibration absorber

Abstract

This paper is concerned with feedback vibration control of a lightly damped flexible structure that has a large number of well-separated modes. A single active electrical dynamic absorber is used to reduce a particular single vibration mode selectively or multiple modes simultaneously. The absorber is realized electrically by feeding back the structural acceleration at one position to a collocated piezoceramic patch actuator via a controller consisting of one or several second order lowpass filters. A simple analytical method is presented to design a modal control filter that is optimal in that it maximally flattens the mobility frequency response of the target mode, as well as robust in that it works within a prescribed maximum control spillover of 2 dB at all frequencies. Experiments are conducted with a free-free beam to demonstrate its ability to control any single mode optimally and robustly. It is also shown that an active absorber with multiple such filters can effectively control multiple modes simultaneously.

MR Damper Controlled Vibration Absorber for Enhanced Mitigation of Harmonic Vibrations

“…Actuators 2016, 5, 27 25 of 28 the MR-SVA with 80% of mass is also computed for 50% of the worst-case excitation 3 w…”

“…Consequently, the concept of the undamped dynamic vibration absorber is highly preferable for controlled mass dampers if the task is to maximally reduce harmonic vibrations with time-varying frequencies. Such controlled vibration absorbers may be based on electrical actuators, shape memory alloys, electrorheological dampers, MR elastomers and MR dampers that allow adjusting in real-time the controllable frequency of the absorber to the actual frequency of vibration [8,[24][25][26][27][28][29][30][31][32].…”

“…Actuators 2016, 5,27 13 of 28clipping and the residual force(Figure 6c-f). Due to the stiffness correction method (Equation(14)) des c .…”

Dynamical Performances of a Vibration Absorber for Continuous Structure considering Time-Delay Coupling

“…Vibration absorbers including passive and active dynamic vibration absorbers received increasing attention in structural vibration control in the past several years [1][2][3][4][5]. The mechanism of a passive vibration absorber is to distribute the vibration energy through coupling a slave structure to the master one [6], while an active vibration absorber produces forces to counteract the vibration through adjusting the slave structure according to the motion state of the master [7].…”

Semi-modal active vibration control of plates using discrete piezoelectric modal filters

“…In the first case, the control strategy is responsible for filtering the sensor(s) output(s) via software and calculating the actuator(s) input(s) so that specific modes or frequency-ranges are targeted. However, this could easily lead to quite cumbersome signal processing requirements [3][4][5].…”