Active noise reduction device and method and noise control system for range hood

Abstract

The invention provides an active noise reduction device. The noise reduction device comprises a first collection module, a second collection module, a judging module, a recursive least squares (RLS) module, a coefficient revising module, a balanced filtering module, an amplifying module and a second noise source module, wherein the first collection module is used for collecting noise signals, the second collection module is used for collecting error signals, and the judging module is used for judging whether the error signals are convergent according to the amplitude of the error signals. The RLS module is used for generating coefficient estimated valve by adopting the RLS algorithm, the coefficient revising module is used for revising the coefficient estimated valve generated by the RLS module according to the judging result, and generating interference offset signals which are in opposite phase with the noise signals. The amplifying module is used for amplifying the interference offset signals according to the amplitude of the noise signals, and the second noise source module is used for generating corresponding offset sound waves according to the amplified interference offset signals. The active noise reduction device is capable of achieving fast tracing of the noise signals according to the RLS algorithm, and at the same time improving real-time tracing performance of complex signals.

Description

technical field [0001] The invention relates to the technical field of electrical design and manufacture, in particular to an active noise reduction device and method and a noise control system for range hoods. Background technique [0002] Because noise pollution has brought a lot of inconvenience to people's production and life, noise control is becoming more and more important. The traditional method of controlling noise sources is mainly to use passive control technology, that is, to use acoustic methods such as sound absorption, sound insulation, and use of mufflers to reduce noise. However, this passive noise reduction mechanism is more effective for mid- and high-frequency noise, but not so effective for low-frequency noise. At the air inlet of the range hood, due to the rapid flow of air, the air rubs against the oil filter screen of the range hood and the inner wall of the range hood, resulting in continuous low-frequency noise. At the same time, at the exhaust ou...

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Problems solved by technology

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art, especially to solve the defect that the current range hood noise is difficult to suppress or eliminate

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