A kind of active damping Dolby circuit and methodTechnical field
The present invention relates to a kind of active damping Dolby circuit and methods, are capable of handling any fixed frequency more particularly to one kindThe active damping Dolby circuit and method of rate disturbing signal.
Background technique
Active damping noise-reduction method has been widely used in industrial design, be mainly used for eliminate electronic product in noise andDisturbance.Active damping method used at present is as shown in Figure 1.
Wherein, P is control object；C is controller；R is system input, and y (t) is system output, and the inside includes known to 1Frequency is frExternal disturbing signal.Dotted portion is the outer active damping added on former control system in figure, and wherein B is oneA bandpass filter, centre frequency fr；K is constant gain coefficient.The transmission function of closed-loop control system shown in FIG. 1 is
Wherein, P, C, B, K are respectively control object, controller, bandpass filter and the transmission function of gain.
Theoretically, if selection B and K appropriate makes in frequency frLocate PC-PBK=0, then in frequency frThe noise at placeOr the influence of disturbance can completely eliminate.But actually this method there is a problem that following reducing noise to not can guaranteeValidity:
In current active damping Method of Noise, the value of gain coefficient K is selected as controller C in frThe gain at place, and band logicalFilter B is in centre frequency frThe gain at place is 1, and such PBK and PC are in frequency frThe gain at place is identical, i.e., | PC |=| PBK |,But PBK and PC are not can guarantee in frequency frThe phase at place is identical.Therefore actually in frequency frLocate PC-PBK ≠ 0, that is to say, thatPBK and PC are depended entirely in frequency f to the inhibition level of noiserThe phase difference at place, so current method is mainly used forTackling phase is random disturbing signal, and is that fixed disturbing signal effect is then unobvious for phase.
Summary of the invention
In order to overcome the deficiencies of the above existing technologies, purpose of the present invention is to provide a kind of active damping Dolby circuitsAnd method, it can be adapted for the disturbing signal of any fixed frequency, can not only significantly improve the rejection ability to noise, togetherWhen greatly simplifie the complexity of design and realization.
In view of the above and other objects, the present invention proposes a kind of active damping Dolby circuit, comprising:
Input signal and output signal operation are obtained the error signal comprising interference by input summer；
Controller connects the output end of the input summer, connects all the way after the error signal that this includes interference is handledAdder is eliminated to noise, another way is connected to noise filter；
Noise filter, the other end are connected to noise and eliminate adder；
Noise eliminates adder, control signal of the output by noise elimination to controlled device；
Controlled device, output signal simultaneously feed back to the input summer.
Further, which is multiple, and one end connects the controller after multiple noise filter is in parallel, separatelyOne end connects the noise and eliminates adder.
Further, which subtracts each other input signal and output signal to obtain the error letter that this includes interferenceNumber.
Further, which is used for the noise reduction to the disturbing signal of any fixed frequency.
In order to achieve the above objectives, the present invention also provides a kind of active damping noise-reduction method, include the following steps:
Input signal and output signal are obtained the error signal comprising interference by input summer operation by step 1；
Step 2 is sent all the way to noise after handling the error signal via controller that this includes interference and eliminates adder, separatelyIt is sent again after being sent all the way to noise filter filtering to noise and eliminates adder；
Step 3 eliminates adder by noise and exports noise canceled control signal to controlled device, the control pairAs output signal is fed back to the input summer.
Further, in step 2, another way is sent again after sending to the noise filter filtering of multiple parallel connections to the noiseEliminate adder.
Further, in step 1, input signal is subtracted each other to obtain this with output signal by input summer includeThe error signal of interference.
Further, this method is used for the noise reduction to the disturbing signal of any fixed frequency.
Compared with prior art, the present invention is a kind of active damping Dolby circuit and method, be can be adapted for any solidDetermine the disturbing signal of frequency, can not only significantly improve the rejection ability to noise, while greatly simplifiing design and realizationComplexity.
Detailed description of the invention
Fig. 1 is the structural schematic diagram of the active damping noise reduction system of the prior art；
Fig. 2 is a kind of circuit diagram of first preferred embodiment of active damping Dolby circuit of the present invention；
Fig. 3 is a kind of circuit diagram of second preferred embodiment of active damping Dolby circuit of the present invention；
Fig. 4 is a kind of step flow chart of active damping noise-reduction method of the present invention；
Fig. 5 is the validity test result figure of the present invention.
Specific embodiment
Below by way of specific specific example and embodiments of the present invention are described with reference to the drawings, those skilled in the art canUnderstand further advantage and effect of the invention easily by content disclosed in the present specification.The present invention can also pass through other differencesSpecific example implemented or applied, details in this specification can also be based on different perspectives and applications, without departing substantially fromVarious modifications and change are carried out under spirit of the invention.
Fig. 2 is a kind of circuit diagram of first preferred embodiment of active damping Dolby circuit of the present invention.Such as Fig. 2 instituteShow, a kind of active damping Dolby circuit of the present invention, including input summer 10, controller (C) 20, noise elimination adder 30,Controlled device (P) 40 and noise filter (B) 50.
Wherein, input signal r and output signal y subtracts each other to obtain the error signal comprising interference in input summer 10, shouldError signal via controller (C) 20 comprising interference is connected to noise all the way and eliminates one of adder 30 input terminal after handling, separatelyAnother input terminal that noise eliminates adder 30 is connected to after the filtering of noise filter (B) 50 all the way, noise eliminates adderThe control signal that 30 output end output is eliminated by noise is to controlled device (P) 40, and 40 output signal y of controlled device (P) is againPassback input summer 10 carries out noise elimination again.
According to background technique, if selection B and K appropriate makes in frequency frLocate PC-PBK=0 so in frequency frPlaceThe influence of noise or disturbance can theoretically completely eliminate.If K is not constant in Fig. 1, and it is selected to K=C, thenFig. 1 can varying cost invention Fig. 2, the transmission function of the closed-loop control system shown in Fig. 2 of the present invention is
Because bandpass filter B is in centre frequency frThe gain at place is 1, to ensure that in frequency frLocate 1-B=0, thereforeIn frequency frThe noise at place can completely eliminate.
It should be noted that, the present invention can be easy to be generalized in system that there are the feelings of multiple given frequency noises hereinCondition.For example have the noise of n different frequency in system, it is located at fr1, fr2..., frnPlace.N band logical filter can so be designedWave device, B1, B2..., Bn, centre frequency is respectively fr1, fr2..., frn, the n bandpass filter latter termination control in parallelDevice (C), another termination noise eliminate adder, as shown in figure 3, the design by Fig. 3 can eliminate this n noise simultaneously.
Fig. 4 is a kind of step flow chart of active damping noise-reduction method of the present invention.As shown in figure 4, a kind of active of the present inventionDamping noise-reducing method, includes the following steps:
Step 401, input signal r and output signal y is subtracted each other to obtain the error letter comprising interference by input summerNumber.
Step 402, it is sent all the way after the error signal via controller that this includes interference being handled to noise and eliminates adder, separatelyIt is sent again after being sent all the way to noise filter filtering to noise and eliminates adder；
Step 403, adder is eliminated by noise and exports noise canceled control signal to controlled device, the control pairAs output signal is fed back to the input summer.
Preferably, another way, which is sent again after sending to the noise filter filtering of multiple parallel connections to the noise, to disappear in step 402Except adder.
Fig. 5 is the validity test result figure of the present invention.Signal in Fig. 5 is measured from practical hard disk controlling systemIt arrives.It is obvious that there is serious disturbances (solid line in figure) in 1830Hz or so system, and if be not pocessed, systemPerformance will receive very serious influence.Dotted line is the result applied after the present invention in systems in figure, it can be seen that the present inventionRemoval 1830Hz that can be very clean disturbs the influence to system, to demonstrate the validity of this patent.
Compared to now widely used active damping noise-reduction method, the present invention is same the complexity for reducing designWhen, hence it is evident that the rejection ability to noise is improved, while the present invention also increases the scope of application of active damping noise reduction technology, energyEnough handle the disturbing signal of any fixed frequency.
The above-described embodiments merely illustrate the principles and effects of the present invention, and is not intended to limit the present invention.AnyWithout departing from the spirit and scope of the present invention, modifications and changes are made to the above embodiments by field technical staff.Therefore,The scope of the present invention, should be as listed in the claims.