Active noise control: a tutorial review

Abstract

Active noise control (ANC) is achieved by introducing a canceling "antinoise" wave through an appropriate array of secondary sources. These secondary sources are interconnected through an electronic system using a specific signal processing algorithm for the particular cancellation scheme. ANC has application to a wide variety of problems in manufacturing, industrial operations, and consumer products. The emphasis of this paper is on the practical aspects of ANC systems in terms of adaptive signal processing and digital signal processing (DSP) implementation for real-world applications. In this paper, the basic adaptive algorithm for ANC is developed and analyzed based on single-channel broad-band feedforward control. This algorithm is then modified for narrow-band feedforward and adaptive feedback control. In turn, these single-channel ANC algorithms are expanded to multiple-channel cases. Various online secondary-path modeling techniques and special adaptive algorithms, such as lattice, frequency-domain, subband, and recursive-least-squares, are also introduced. Applications of these techniques to actual problems are highlighted by several examples.

Application of wave field synthesis to active control of highly non-stationary noise

“…Nevertheless, a residual rear acoustic emission is present and a feedback path from SS to RM may create echoes that must be avoided. Feedback path modeling and neutralization are well-established issues in the literature [2] and represent crucial aspects in the practical realization of feedforward ANC systems. The feedback path induces a closed loop gain on the RM input and the overall feedforward ANC system must be modeled as an infinite impulse response (IIR) filter; solutions based on offline path estimation [2] and on-line adaptive filtering [24][25] [26] have been proposed.…”

“…Thus, thanks to the principle of superposition, the primary source of noise is cancelled. An ANC system is particularly effective when the region where it operates is limited, e.g., in headset, ducts, car and airplane cabins, and is more convenient to diminish low frequency noise than passive methods [1] [2].…”

Novel Variable Step-Size Gradient Adaptive Lattice Algorithm for Active Noise Control

“…[2] 대표적으로 FxLMS(Filtered-x least Mean Square) 알 고리즘은 비교적 간단한 구조로 안정적인 수렴 성능 을 보장하기 때문에 널리 사용되고 있다. [3] 하지만, 유색 잡음 특성을 갖는 신호의 입력은 수렴 성능 저 하의 요인이 된다.…”

Robust stability and performance of adaptive jitter supression in laser beam pointing

“…The problem of adaptive rejection of unknown sinusoidal disturbances has been already investigated in many applications such as acoustic noise cancelation , mechanical vibration control, wavefront control in adaptive optics, and active tracking in laser systems [8]- [14]. In [15], adaptive rejection of band-limited disturbances with unknown frequencies is studied through an internal model principle.…”