Feed-forward active noise barrier

Abstract

The invention discloses a feed-forward active noise barrier, which comprises a passive noise barrier and a single-channel feed-forward active control system array. Each single-channel feed-forward active control system forming the array comprises a reference microphone, an error microphone, a secondary sound source and a single-channel controller. The secondary sound sources are arranged on the top of the passive noise barrier. The reference microphones are positioned on one side of a noise source and close to the top of the barrier. The error microphone is positioned on one side of an observation point and close to the top of the barrier. The controller of each single-channel feed-forward active control system is used for controlling the output of the corresponding secondary sound source so as to minimize a square value of sound pressure amplitude at the position of the corresponding error microphone, and adopts a feed-forward single-channel adaptive control algorithm. Each single-channel control system is compact, has low cost and is easy to implement. The problems of high implementing difficulty and high cost when a multi-channel control system is used are solved. Compared with the conventional feedback active noise barrier, the feed-forward active noise barrier has high system stability and a good control effect and does not have a water bed effect due to the adoption of the feed-forward control systems.

Description

1. Technical field [0001] The invention relates to a noise barrier, in particular to an active sound barrier. 2. Background technology [0002] With economic development and social progress, the scale of road traffic and rail traffic is increasing day by day, and the problem of traffic noise is becoming more and more prominent. In order to eliminate traffic noise and protect people on both sides of the road and the track, the way of building noise barriers on both sides of the road and the track is usually adopted. Traditional sound barriers, that is, passive sound barriers, are constructed of sound-insulating materials. The principle is to block the direct sound of noise. Because low-frequency noise is easy to diffract from the top of the barrier, it has poor noise reduction effect in low-frequency bands. Active noise control technology eliminates noise through the principle of "muffling noise with sound". It has a good effect in low-frequency noise reduction, is easy to i...

AI Technical Summary

Problems solved by technology

However, the feedback controller has two disadvantages: (1) the error microphone must be close to the secondary sound source to stabilize the system, so the control effect is limited; (2) there is a water bed effect, that is, noise attenuation in some frequency bands will inevitably lead to other Enhanc

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