Active control system for tyre-ground contact rolling noise: an experimental facility

A new active system for reduction of rolling noise produced by tyre-ground contact is proposed (patent n.01297959). The system is constituted by acoustical emitters installed on the car mudguard close to tyre-ground point of contact. Acoustical emitters are fed by an electronic control unit which generates the control signal according to an error minimization technique. Acoustical emitter performances have been tested by means of an original experimental facility built at Acoustic Laboratory of the University of Perugia. Such a facility allows to optimize the acoustical performances of the active noise control system by simulating rolling noise on steady conditions. Active noise control emitter has been modeled by means of electrical equivalent circuit method; thus, transfer function has been attained.