Active Structural Acoustic Control of an Active Casing Placed in a Corner

Abstract

Electric appliances used in workplaces and everyday life often generate a low-frequency noise, which affects human body systems. Passive methods employed to reduce noise are not effective at low frequencies. The classical approach to active noise control practically involves the generation of local zones of quiet, whereas at other areas the noise is reinforced. Moreover, it usually requires a large number of secondary sound sources. Hence, an active casing approach has been developed. The active casing panels’ vibrations are controlled to reduce the device noise emission. Efficiency of this method has been previously confirmed by the authors and the results have been reported in multiple journal publications. However, in the previous research experiments, the active casing was placed at a distance from the enclosure walls. In this research, the active casing is located in a corner and such placement is intentionally used to facilitate the active control system’s operation. The noise reduction performance is investigated at multiple configurations, including a range of distances from the corner and different error microphone arrangements. The analysis of both primary and secondary paths is given. Advantages and drawbacks of different active casing configurations are presented and discussed.

ANC System Modeling and Simulations in a Wide-Area Virtual Environment Using FDTD Approach with Perfectly Matched Layer Absorbing Boundaries

“…Some researchers mainly focused on ANC algorithms improvements, for example, Dah-Chung Chang presented the new FXLMS algorithm with a variable tap length and a step size to improve convergence rate and noise reduction ratio [4], Ardekani and Abdulla introduced the ANC with the emphasis on ANC system implemented using FXLMS adaptation algorithm [5]. Some researchers concentrated on expanding ANC applications, for example, Sen Kou applied a feedback active noise control technique for headphone applications [6], László Sujbert presented the ANC noise-cancelling office chair to resolve the uncomfortable problem of employees wearing a noise-cancelling headphone in the office using a multiple reference microphones technique [7], Chraponska, Wrona, Rzepecki, Mazur and Pawelczyk proposed the active structural acoustic control of ANC active casing placed in the corner to protect the low-frequency noise from electrical appliances [8].…”

Spectral Analysis of Macro-Fiber Composites Measured Vibration of Double-Panel Structure Coupled with Solenoids

“…Such casing may differ in its design and properties. In previous research, the authors proposed, inter alia, one of SSD’s variants [ 25 ] as a robust semi-active approach in case of a rigid device casing, and an Active Structural Acoustic Control approach to control a lightweight active casing placed at a wall [ 26 ] or in a corner [ 27 ].…”

Chladni Figures in Modal Analysis of a Double-Panel Structure

“…One of the approaches to globally reduce noise and vibration may be a casing, which encloses a noise-generating device. The authors previously examined the active [ 12 ] and semi-active [ 13 , 14 ] approaches to reduce noise or vibration with the use of light-weight and rigid casings. Novel improvements are being developed to enhance the effect of noise and vibration reduction.…”