Abstract
This paper describes the active control systems for reducing floor impulse noise. The control system is comprised of actively controlled modular thin plates, which wholly cover the surface of concrete slab structure in the ceiling, and in each of which the mechanical vibration is controlled independently with bimorph type piezoelectric actuators. An active control system of modular plate is presented, where five sensors and actuators are applied to control low frequency modes of bending vibration in the plate. The control system is now under development, main subjects of which are; 1) designing of vibration characteristics of modular thin plate, 2) the active control system appropriate to the characteristics and cost reduction of the actuators and sensors. Subject 1) is mainly discussed below.