Active control of noise and vibration for time-varying transfer paths

Acoustic characteristics and noise control measures for steel road bridges

The effect of floating deck structures on underwater radiated noise

A concept for underwater machinery noise mitigation of future civil and military ships is the application of a common deck structure, supporting multiple machines, which is installed on resilient mounts on the ship's foundation structure. TNO is addressing the availability and testing of tools to be able to set realistic targets for the radiated...

Active control of time-varying broadband noise using online system identification with parallel fast-array recursive least squares filters

A numerically stable, finite memory, fast array recursive least squares filter for broadband active noise control

Summary For broadband active noise control applications with a rapidly changing primary path, it is desirable to find algorithms with a rapid convergence, a fast tracking performance, and a low computational cost. Recently, a promising algorithm has been presented, called the fast-array Kalman filter, which uses rotation matrices to calculate...

Parallel fast-array recursive least squares filters for active noise control with on-line system identification

Active noise control with fast array recursive least squares filters using a parallel implementation for numerical stability

Noise reduction in feedforward active noise control systems with a rapidly changing primary path requires rapid convergence and fast tracking. This can be accomplished with a fast-array Kalman method which uses an efficient rotation matrix technique to calculate the filter parameters. However, finite precision effects lead to unstable behavior....

Model based monitoring for industrial and traffic noise control

Noise control starts by understanding the actual noise situation. Especially for situations where the distance between industrial and traffic noise sources and a local community is in the order of one kilometer or more, it may not be clear what sources are the main contributors to annoyance. Then a combination of monitoring and modeling is...

Tracking and convergence of multi-channel Kalman filters for active noise control

The feed-forward broadband active noise control problem can be formulated as a state estimation problem to achieve a faster rate of convergence than the filtered reference least mean squares algorithm and possibly also a better tracking performance. A multiple input/multiple output Kalman algorithm is used to perform this state estimation. To...

Development of Dynamic Loudspeakers Modified as Incident Pressure Sources for Noise Reductiuon in a Double Panel Structure

This paper presents a modified loudspeaker source for decentralized feedback cavity control in a double panel structure to reduce the noise transmission. The double panel structure con-sists of two panels with air in between and offers the advantages of low weight, low sound transmission at high frequencies, and thermal insulation. The main...

Real-time Kalman filter implementation for active feedforward control of time-varying broadband noise and vibrations

Tracking behavior and the rate of convergence are critical properties in active noise control applications with time-varying disturbance spectra. As compared to the standard filtered-reference Least Mean Square (LMS) algorithm, improved convergence can be obtained with schemes based on preconditioning, affine projections, Recursive Least Squares...

Rapidly converging multichannel controllers for broadband noise and vibrations

Applications are given of a preconditioned adaptive algorithm for broadband multichannel active noise control. Based on state-space descriptions of the relevant transfer functions, the algorithm uses the inverse of the minimum-phase part of the secondary path in order to improve the speed of convergence. A further improvement of the convergence...

Fast affine projections and the regularized modified filtered-error algorithm in multichannel active noise control

In this paper, real-time results are given for broadband multichannel active noise control using the regularized modified filtered-error algorithm. As compared to the standard filtered-error algorithm, the improved convergence rate and stability of the algorithm are obtained by using an inner-outer factorization of the transfer path between the...

Railway noise measurement method for pass-by noise, total effective roughness, transfer functions and track spatial decay

In recent years, considerable effort has been spent at a European level to establish comprehensive methods for the experimental assessment of rolling noise emission of rail-bound vehicles and tracks. This work was concentrated in the European METARAIL and STAIRRS projects. The objective of these was to improve the accuracy and the...

Convergence analysis of the Filtered-U LMS algorithm for active noise control in case perfect cancellation is not possible

The Filtered-U LMS algorithm, proposed by Eriksson for active noise control applications, adapts the coefficients of an infinite-impulse response controller. Conditions for global convergence of the Filtered-U LMS algorithm were presented by Wang and Ren (Signal Processing, 73 (1999) 3) and Mosquera and Pérez-González (Signal Processing, 80 ...

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