Compact, inexpensive, analog robust controller modules for cabin noise control

Abstract

Control of noise in an enclosure when the noise source is exterior to the enclosure has applications to rooms, automobiles, helicopters, airplanes, and other vehicles. Reducing the interior noise to acceptable levels is necessary for safety and comfort. One approach to control of interior noise is through vibration suppression of the trim panels that often line the interior of such enclosures. It is ultimately these trim panels that reradiate the noise to the interior. In order to actively control the vibrations of the trim panels, using discrete piezoelectric sensors and actuators, control electronics are needed. Adaptive digital control, while being efficient and powerful, also requires the presence of a computer and DSP boards. There may also be frequency limitations posed by the speed of available DSP boards. An alternative approach is to design compact and inexpensive analog controller units, which also offers the possibility of having such controllers designed as ASIC chips. To demonstrate the efficacy of this approach, results will be presented for the control of noise in a cabin with multiple trim panels when excited by broadband noise from the exterior using MEMS vibration sensors and PZT actuators.