Active vibration control using fiber Bragg grating sensors and piezoelectric actuators in co-located configuration

Abstract

ABSTRACT In this paper, the feasibility of an active vibration control scheme using Fiber Bragg Grating (FBG) sensors and piezoelectric (PZT) actuators for vibration suppression of an aluminum plate is investigated. Four FBGs have been bonded to the structure below the same number of PZT actuators in co-located conf iguration. A Proportional-Derivative controller has been used to generate the command signals required to drive the actuators. Preliminary results from “closed loop” configuration tests are reported showing up to 17 dB of noise reduction at 80 Hz. Keywords: Fiber Bragg Gratings, piezoelectric actuators, active vibration control 1. INTRODUCTION In the last two decades, Active Vibration Control (AVC) methods have attracted increasing interest due to the numerous applications in which they could be adopted. In the aerospace field, the need of such an approach arises especially in order to suppress aircraft and helicopter interior acoustic noise having frequencies up to 1 kHz, leading to reduced system effectiveness, human discomfort and structural fatigue [1]. Within this range of frequencies, the traditional passive damping techniques are practically ineffective and the system redesi gn is often much co stly [1]. In active control, the effect of unwanted noise is cancelled by voluntary addition of controlled signals, opposite in sign but equal in magnitude [2] To this aim, active materials fo r actuating or sensing include piezoelectric materials, shape memory alloys (SMAs), electrostrictive materials, electrorheological fluids, magnetostrictive materials and fiber optics [3]. As actuators, piezoceramic materials are the most used due to their low-cost, lightwei ght, mechanical simplicity and bandwidth [4]. On the other hand, as sensors , Fiber Bragg gratings [5] ha ve been also demonstrated the su itable sensing technology for smart structures applications [6-9] thanks to their accuracy, resolution sensitivity, immunity to electromagnetic interference and high multiplexing capability [5]. In this work, a test aluminum proof in fixed fixed beam configuration has been sensorized with four fiber Bragg grating sensors. Each FBG is bonded below a PZT element on the aluminum plate by using a suitable bonding procedu re forming a co-located configuration. A proportional derivative controller has been used to drive the PZT elements based on the signals provide by the sensing elements. Also, a numerical analysis of the structure has been carried out in order to predict the