In this paper, a subspace identification solution is provided for Active Noise Control (ANC) problems. The solution is related to so-called block updating methods, where instead of updating the (feedforward) controller on a sample by sample base, it is updated each time based on a block of N samples. The use of the subspace identification based ANC methods enables non-iterative derivation and u...

For output-feedback adaptive control of affine nonlinear systems based on feedback linearization and function approximation, the observation error dynamics usually should be augmented by a low-pass filter to satisfy a strictly positive real (SPR) condition so that output feedback can be realized. Yet, this manipulation results in filtering basis functions of approximators, which makes the order...

Digital active noise control (ANC) for headphones usually has to predict the noise because of the latency of AD-conversion. In adaptive feedback ANC, the prediction is based on the noise that entered the headphone. This noise is low pass filtered due to the physical barrier of the ear cups. In this paper, this low pass characteristic is exploited to define a prediction filter which does not req...

The feedback-type active noise control (ANC) system uses only one microphone to provide necessary signals for adjusting the adaptive lter. Due to the complicated nature of the whole adaptive lter structure there have been no theoretical results about its convergence properties. In this paper, rst a stationary point of the adaptive lter using the ltered-X LMS algorithm is obtained by the averagi...

abstract background: improving the utilization rate of antenatal care is a critical strategy for achieving the reproductive health goals in iran. the aim of this study was to assess the utilization rate of antenatal care (anc) by women after health sector reform (hsr) interventions in rural areas of islamic republic of iran (ir iran). materials and methods: this is a retrospective cross-section...

This letter proposes a method for active noise control (ANC) systems with online acoustic feedback neutralization. The proposed method is a modified version of authors’ previous work, and the objective here is to reduce the computational complexity. This is achieved by combining the role of feedback path modeling and neutralization filters. The computer simulations are carried out which demonst...

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 pr...

ADAPTIVE RESONANT MODE ACTIVE NOISE CONTROL Adam K. Smith, MS University of Pittsburgh, 2005 Low frequency sound waves propagating in a duct is ideally suited for active noise control (ANC) applications. Unlike passive treatments, ANC utilizes an acoustic actuator (loudspeaker) to cancel unwanted sound fields. There are two main control topologies when considering the active suppression of soun...

This paper proposes a new method for online secondary path modeling in feedback active noise control (ANC) systems. In practical cases, the secondary path is usually time-varying. For these cases, online modeling of secondary path is required to ensure convergence of the system. In literature the secondary path estimation is usually performed offline, prior to online modeling, where in the prop...