Electro-acoustic and acousto-optic communications for robotic agents in smart structures

Abstract

Electro-Acoustic and Acousto-Optic communications channels have been investigated. The communications channels are intended for use by robotic agents in the Non-Destructive Evaluation (NDE) of structures containing distributed Acoustic Emission (AE) sensors. The AE sensors can be either piezoelectric or optical fibre sensors. The communications channel comprises of a piezoelectric transducer as the transmitter, an aluminium panel as the transmission medium, and either a second piezoelectric transducer or a fibre optics sensor as the receiver. The electroacoustic communications channel uses the piezoelectric transducers as the transmitter and the receiver. The acousto-optic communications channel uses a piezoelectric transducer as the transmitter, and a fibre optic sensor as the receiver. Acoustic communications represents a wireless communications method that does not require any additional hardware, as piezoelectric transducers are commonly used in the NDE of materials. Phase Shift Keying (PSK) was used for the communications encoding. Successful communications was achieved using both the piezoelectric and fibre optic receivers. The fibre optic sensor used was a Fibre Bragg Grating (FBG), and the piezoelectric transducers were Lead Zirconate Titanate (PZT) piezoceramic disc transducers. The electro-acoustic communications channel gave a data rate of 200kbps with a 1MHz square wave carrier. The acousto-optic communications channel gave a data rate of 6.3568kbps with a 635.68kHz carrier wave.