An active damping noise reduction circuit and method

Abstract

The invention discloses an initiative damping noise reduction circuit and method. The circuit comprises: an input adder which operates an input signal and an output signal to obtain error signals containing interference, a controller which is connected to the output end of the input adder and processes the error signals containing interference, wherein one way of the controller is connected to a noise elimination adder, the other way is connected to a noise reduction filter; the noise reduction filter of which the other end is connected to the noise elimination adder; the noise elimination adder which outputs noise eliminated control signals to a controlled object; and the controlled object which outputs the signals and feeds back to the input adder. According to the invention, the noise inhibition capability is remarkably improved; and simultaneously the design and realization complexity is greatly simplified.

Description

technical field [0001] The invention relates to an active damping and noise reduction circuit and method, in particular to an active damping and noise reduction circuit and method capable of processing any fixed-frequency disturbance signal. Background technique [0002] Active damping noise reduction methods have been widely used in industrial design, mainly to eliminate noise and disturbance in electromechanical products. Currently used active damping methods such as figure 1 shown. [0003] Among them, P is the control object; C is the controller; r is the system input, y(t) is the system output, which contains a known frequency f r external disturbance signal. The dotted line in the figure is the active damping added on top of the original control system, where B is a band-pass filter with a center frequency of f r ; K is a constant gain coefficient. figure 1 The transfer function of the closed-loop control system shown is [0004] [0005] Among them, P, C, B, ...

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Problems solved by technology

But in fact, this method has the following problems, which cannot guarantee the effectiveness of noise reduction:

[0007] In the current active damping noise reduction method, the value of the gain coefficient K is selected as the value of the controller C at f r Gain at , while the bandpass filter B is at the center frequency f r The gain at is 1, so that PBK and PC are at frequency f r The gain at the position is the same, that is, |PC|=|PBK|, but there is no guarantee that PBK and PC are at frequency f r at the same phase

So actually at frequency f r At PC-PBK≠0, that is to say, the degree of noise suppression depends entirely on PBK and PC at frequency f r Therefore, the current method is mainly used to deal with the disturbance signal whose phase is random, but the effect on the disturbance signal whose phase is fixed is not obvious.

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