Acoustic guitars are appreciated for their bright and clean ringing sound, combined with a relatively balanced frequency spectrum due to the resonant body, but they don't allow a broad variation of timbers, as electric guitars do. It is now possible, thanks to the "electroacoustic resonator" concept developed in the Acoustic Group at LTS2, to modify the dynamics of a naturally vibrating body (eg a guitar board) by using electromechanical exciters (piezoelectric or electrodynamic actuators) and a feedback loop driving back the exciter with a prescribed force. We aim at investigating the application of this technique to controlling the dynamics of guitar boards, with a view to developing a novel "augmented" acoustic guitar, allowing changing the timber in real time, as with electric guitars.

An alternative concept has been achieved at IRCAM (Institut Recherche et Création Acoustique Musicale of Paris) in 2014, under the label "smartinstruments".

The expected work will consist in designing a numerical model of a guitar board to identify its modal behaviour, and then simulate the action of an active exciter with a feedback loop (with or without sensors), owing to the "electroacoustic resonator" concept. Several control strategies will be assessed resulting in the selection of components (type and position of exciter(s), eventual sensor(s)) and the optimal control strategy. A prototype of an active guitar will then be built and tested in laboratory conditions.

Profile: Electrical engineering, Micro-engineering, Physics, Mechanics

Prerequisites: Electroacoustique (BA5) or Audio Engineering (MA1)

Context: Theory (20%), design (60%), experiments (20%)