Integrated smart actuator containing a monolithic coformed accelerometer

Abstract

A general need exists for inexpensive finite-area transducer arrays which Intrinsically combine acoustic or vibration sensing with area actuation. Such combination transducers are particularly needed in active sound and vibration control and smart-materials applications. Commercial areas of Interest Include advanced underwater, aerospace or robotic-sensing applications. To be economically attractive they must be relatively simple to manufacture from reasonable cost materials. One promising new technology for such applications is Injection-molded 1-3 composite piezo-ceramics, pioneered by Material Systems Inc. (MSI). This transducer material is well suited for use as the low-cost actuator component of such a smart actuator. The challenge of this study was to design an Inexpensive accelerometer which could be Injection molded along with the actuator as an Interspersed array. This paper describes a monolithic accelerometer which is suitable for fabrication by injection-molding as an integrated co-formed actuator component. Experimental results are presented for actuator I accelerometer arrays and issues related to the design and use of accelerometers In close proximity to an actuator are discussed.

Low-frequency active noise control of an underwater large-scale structure with distributed giant magnetostrictive actuators

“…The hydrophone array is composed of 16 hydrophones. The horizontal distance between two hydrophones is 20 cm and the longitudinal distance between two hydrophones is 0.40 m. The hydrophone marked in red at Location [3,4] in the array is at the center point of the plate.…”

“…Structures for active noise control employing piezoelectric ceramics [1] and accelerometers for underwater targets are referred to as "Smart Tiles", this terminology was introduced by the Naval Civil Engineering Laboratory in 1996 [2][3][4]. Multifunctional active noise reduction structures can have many concurrent functions such as active sound absorption, active sound insulation and active sound radiation control [5].…”