Signal to noise ratio improvement of in situ absorption measurement using active noise control approach

2013 ◽  
Author(s):  
P. Steblaj ◽  
J. Prezelj ◽  
P. Lipar ◽  
M. Cudina
Keyword(s):  
Noise Control ◽  
Signal To Noise Ratio ◽  
Active Noise Control ◽  
Absorption Measurement ◽  
Signal To Noise ◽  
Control Approach ◽  
Active Noise ◽  
Noise Ratio ◽  
In Situ Absorption

Active Noise Hybrid Feedforward/Feedback Control Using Neural Network Compensation*

2001 ◽  
Vol 124 (1) ◽  
pp. 100-104 ◽  
Author(s):  
Zhang Qizhi ◽  
Jia Yongle
Keyword(s):  
Neural Network ◽  
Noise Control ◽  
Control Method ◽  
Active Noise Control ◽  
Equivalent Model ◽  
Gradient Descent Method ◽  
Nonlinear Simulation ◽  
Control Approach ◽  
Active Noise ◽  
Nonlinear Noise

The nonlinear active noise control (ANC) is studied. The nonlinear ANC system is approximated by an equivalent model composed of a simple linear sub-model plus a nonlinear sub-model. Feedforward neural networks are selected to approximate the nonlinear sub-model. An adaptive active nonlinear noise control approach using a neural network enhancement is derived, and a simplified neural network control approach is proposed. The feedforward compensation and output error feedback technology are utilized in the controller designing. The on-line learning algorithm based on the error gradient descent method is proposed, and local stability of closed loop system is proved based on the discrete Lyapunov function. A nonlinear simulation example shows that the adaptive active noise control method based on neural network compensation is very effective to the nonlinear noise control, and the convergence of the NNEH control is superior to that of the NN control.

scholarly journals Active Noise Control Experiments using Sound Energy Flu

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Uli Krause
Keyword(s):  
Noise Control ◽  
Active Noise Control ◽  
Sound Field ◽  
Acoustic Energy ◽  
Control Approach ◽  
Active Noise ◽  
Acceleration Sensors ◽  
Radiated Sound ◽  
Set Up ◽  
Feed Forward Controller

AbstractThis paper reports on the latest results concerning the active noise control approach using net flow of acoustic energy. The test set-up consists of two loudspeakers simulating the engine noise and two smaller loudspeakers which belong to the active noise system. The system is completed by two acceleration sensors and one microphone per loudspeaker. The microphones are located in the near sound field of the loudspeakers. The control algorithm including the update equation of the feed-forward controller is introduced. Numerical simulations are performed with a comparison to a state of the art method minimising the radiated sound power. The proposed approach is experimentally validated.

Inversion-Based Feedforward Approach to Broadband Acoustic Noise Reduction

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Tom C. Waite ◽  
Qingze Zou ◽  
Atul Kelkar
Keyword(s):  
Noise Control ◽  
Feedforward Control ◽  
Acoustic Noise ◽  
Active Noise Control ◽  
Low Frequency ◽  
Control Technique ◽  
Frequency Range ◽  
Nonminimum Phase ◽  
Control Approach ◽  
Active Noise

In this article, an inversion-based feedforward control approach to achieve broadband active-noise control is investigated. Broadband active-noise control is needed in many areas, from heating, ventilation and air conditioning (HVAC) ducts to aircraft cabins. Achieving broadband active-noise control, however, is very challenging due to issues such as the complexity of acoustic dynamics (which has no natural roll-off at high frequency, and is often nonminimum phase), the wide frequency spectrum of the acoustic noise, and the critical requirement to overcome the delay of the control input relative to the noise signal. These issues have limited the success of existing feedforward control techniques to the low-frequency range of [0,1]kHz. The modeling issues in capturing the complex acoustic dynamics coupled with its nonminimum-phase characteristic also prevent the use of high-gain feedback methods, making the design of an effective controller to combat broadband noises challenging. In this article, we explore, through experiments, the potential of inversion-based feedforward control approach for noise control over the 1kHz low-frequency range limit. Then we account for the effect of modeling errors on the feedforward input by a recently developed inversion-based iterative control technique. Experimental results presented show that noise reduction of over 10–15dB can be achieved in a broad frequency range of 5kHz by using the inversion-based feedforward control technique.

A Modern Control Approach to Active Noise Control

1993 ◽  
Vol 115 (4) ◽  
pp. 673-678 ◽  
Author(s):  
R. Shoureshi ◽  
L. Brackney ◽  
N. Kubota ◽  
G. Batta
Keyword(s):  
Noise Control ◽  
Dimensional Space ◽  
Active Noise Control ◽  
Adaptive Signal Processing ◽  
Minimum Variance ◽  
Research Literature ◽  
Pole Placement ◽  
Control Approach ◽  
Active Noise ◽  
Modern Control

Active noise control systems currently in use and/or described in the research literature are typically based on adaptive signal processing theory or, equivalently, adaptive feedforward control theory. This paper presents a modern control approach to the problem of active noise cancellation in a three-dimensional space. The controller is designed based on a direct self-tuning regulator. Two forms of adaptive control, namely, pole placement and minimum variance controls are considered and compared in simulation. An implementation of the adaptive minimum variance controller is used to successfully attenuate a harmonic disturbance in a laboratory setting.

A Novel Approach to Active Noise Control using Normalized Clipped Adaptive Algorithm

2013 ◽  
Vol 3 (3) ◽  
pp. 76-88
Author(s):  
A. Chandra Mouli ◽  
Ch. Ratnam
Keyword(s):  
Adaptive Algorithm ◽  
Noise Control ◽  
Signal To Noise Ratio ◽  
Active Noise Control ◽  
Low Complexity ◽  
Least Mean Square ◽  
Mechatronic Systems ◽  
Active Noise ◽  
Novel Approach ◽  
Systems Simulation

In this paper, an efficient normalization based adaptive algorithm is used for active noise control in mechanical systems in order to reject extensive disturbances. The proposed implementations are suitable in applications like various motors, generators, aircrafts, battle field and elevators, etc where noise reduction is very important. In the experiments, the authors used several variants of the familiar Filtered X Least Mean Square (FXLMS) algorithm. In FXLMS the vector of past inputs is first filtered by the secondary path transfer function, hence it is named as filtered X LMS. These modified results normalized FXLMS (NFXLMS) and normalized clipped FXLMS (NCFXLMS) algorithms, leads to fast convergence, better noise rejection capability. The NCFXLMS algorithm requires only half of the multiplications requires than NFXLMS. This type of low complexity strategy is not used in active noise control application in mechatronic systems. Simulation results prove that the proposed active noise cancellers provide better performance in terms of signal to noise ratio than the conventional FXLMS.

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