METHOD FOR INITIALIZING SECONDARY PATH ADAPTIVE FILTER INACTIVE NOISE CONTROLLER
The present invention refers to a primary path and a adaptive filter initialization method are disclosed to 2 control method of fixed number active noise. More specifically, the present invention refers to the headphone 2 secondary path characteristics and directly measuring the applied feedback structure of active noise control method of fixed number, based on the final target value of the adaptive filter a primary path 2 measurement by setting the initial value in proximity, convergence speed of the adaptive filter path are provided to improve active noise number control method of fixed initial clock 2 difference which satisfies a are disclosed. Industry's development by the performance become serious illuminates a door number etc. to acoustic disturbances. External noise is a stand-alone headset environment for active noise number number cookies (Active Noise Control, ANC) technology has been developed. Every other ANC technique is the number with the same magnitude and opposite phase to the noise and noise prevention signal for generating the noise having (an anti-noise power), the signal noise signal number overlap to make a stationary substrate. Feedback (feedback) which are effectively number of ANC technique is one microphone noise by a stand-alone substrate. In ANC technology used in the headset when, the output signal 2 secondary path to be affected, LMS (least mean square) algorithm general psychology. The FXLMS (filtered LH LMS) algorithm such as 1 also implemented using accomplishing. In Figure 1, d (n) and a microphone collected via a means external noise, the microphone receives auditory canal located near and accomplishing. With this structure 2 in the adaptive filter a primary path and a secondary path transfer function estimating a S S (z) 2* (Z) accomplishing determined. S* (Z) as additional LMS algorithm to disclosure is also 1 obtained by other. Of the existing method ANC S for use in* For obtaining the initial value in the range of 0 (z) updating a filter at the LMS algorithm since converges in the filter which does not, ANC system convergence is slowed down that door number point at the disclosed. Such known according to door number point more specifically described as follows. The FXLMS algorithm is used according to prior art of active noise number feedback structure thereto, for filtering an input signal output speaker noise microphone pathway between the bound substrate. 2 as a primary path and said path, said 2 difference varies according to the use environment control method of fixed number active noise path, through adaptive method determines (adaptive method). 2 secondary path includes the first initial value zero (zero) by adaptation operation start, steady state values gradually converge toward the base. However 2 initial zero path difference becomes at a convergence time bracket, thereby that the slower convergence speed number exists in the strength and the entire control method of fixed number active noise, there exists in the normal operation does not perform the operation initially active noise number number point at the disclosed. The present invention refers to the headphone with active noise number control method of fixed initial clock and containing a number less than 1000. In addition, the present invention refers to the headphone 2 secondary path characteristics and directly measuring the applied feedback structure of active noise control method of fixed number, based on the final target value of the adaptive filter path difference measurement by setting the initial value in the vicinity of the 2, 2 a primary path of the adaptive filter convergence speed and number of metal are provided to improve active noise number control method of fixed initial clock less than 1000. The present invention according to difference path filter initialization method of feedback structure applied to the headphone 2 control method of fixed number active noise number 2 as initial setting method of the adaptive filter path difference in active noise violations, adaptive filter operating in wearing the headphone however measuring experiment 2 2 operational phase and adaptive filter a primary path and a secondary path, an adaptive filter is a primary path and said 2 2 2 converging adaptive filter coefficient values when converging adaptive filter convergence coefficient obtaining a primary path and a secondary path obtains and, said 2 a primary path and a adaptive filter convergence coefficient values to obtain a difference average coefficient 2 2 average average coefficient determining a value of a path a primary path and a decision step and said 2 2 according to the initial value of the adaptive filter a primary path and said 2 average coefficient a primary path and a secondary path and input adaptive filter comprising the following steps. 2 difference path filter initialization method in the present invention according to active noise control method of fixed number, said 2 a primary path and a adaptive filter operation step, said active noise number control method of fixed noise (off) in a state where the number would turn off, said 2 0 headphone set up the initial value of said difference path filter with speaker withdrawn by receiving signal, characterized said 2 primary path with an adaptive filter. 2 difference path filter initialization method in the present invention according to active noise control method of fixed number, characterized in that said learning signal is a white noise. According to the present invention, the headphone with active noise number control method of fixed initial operation performance improved flow tides. In addition, the headphone 2 secondary path characteristics and directly measuring the applied feedback structure of active noise control method of fixed number, based on the final target value of the adaptive filter path difference measurement by setting the initial value in the vicinity of the 2, 2 a primary path of the adaptive filter convergence speed performance is enhanced initial operation control method of fixed number active noise is high and equal to or less. Figure 1 shows a FXLMS (filtered LH LMS) algorithm is generally the functional configuration of the control method of fixed number indicating the feedback active noise are disclosed. Also in Figure 2 shows a the present invention, estimating the transfer function of the secondary path to explain the offline 2 a servomechanism are disclosed. In the embodiment according to Figure 3 shows a method of the present invention indicating the number control method of fixed 2 difference path filter initialization one active noise also are disclosed. In the embodiment of the present invention also included in Figure 4 shows a step of operating a primary path and a 2 one indicating examples of the adaptive filter are disclosed. In the embodiment of the present invention also one in Figure 5 shows a, measurement of experimental autoimmune headphone players who obtained when worn various locations indicating the secondary path frequency response experiment example 2 are disclosed. In the embodiment of the present invention also in Figure 6 shows a one, however headphone obtained when worn in the same position in different measurement experiment 2 example experiment indicating the secondary path frequency response are disclosed. The present invention also 7 and also when using the initial value set by 2 Figure 8 shows a secondary path convergence performance efficiency by prior art compared to viewing surface are disclosed. Prior to of the present invention preferred embodiment is described, of estimating the transfer function of a servomechanism offline 2 refers to the basic principle of the present invention indicating a primary path and 2 to describe the other. S* (Z) offline scheme is also 1 for obtaining a fixing structure such as W (z) ANC system of 0, a signal is reproduced while implementing learning (n), the process in fig. 2 representing road structure such as disclosed. With this structure the following expressions 1 through e (n) errors in the output signal can be obtained. Wherein, S*k (K=0, 1, .., k-a 1) is 2 K (z) for estimating a difference FIR filter S S a primary path* (Z) represents coefficients of the adaptive filter, o (n) micro input signal, i.e., S (z) exhibits a through (n) signal. S* (Z) determines that the LMS algorithm is 2 expressions such as an update. Wherein, the step size μ represents, k=0, 1, .. , K-a 1 are disclosed. In the embodiment according to Figure 3 shows a method of the present invention indicating the number control method of fixed 2 difference path filter initialization one active noise also are disclosed. The further reference also 3, one method of the present invention in the embodiment according to the operational phase 2 2 difference path filter initialization number active noise (S10) adaptive filter control method of fixed primary path, adaptive filter convergence coefficient (S20) obtains a primary path and a 2, 2 average coefficient values of the decision step (S30) and initial value setting adaptive filter 2 a primary path and a secondary path (S40) without using a tool. 2 difference in operating step (S10) adaptive filter path, however in wearing the headphone measuring experiment 2 a primary path and a adaptive filter operating process carried out. 2 adaptive filter operating step (S10) is 1 or more of the measurements in a primary path identifier experiment target e.g., headphone wearing state normal listening position 2 secondary path characteristics process are disclosed. The procedure is simply measuring 2 a primary path and a properties since, as disclosure to also 4, active noise number control method of fixed noise without execution operation of special number, adaptive filter can be configured to only 2 for measuring a primary path. The, said initial value of 0 by the adaptive filter, the adaptive filter can be configured to output sound white noise. Next, the adaptive filter convergence coefficient (S20) obtains a primary path 2, each measurement experiment of coefficient values of the adaptive filter 2 to the user when a few converged 2 a primary path and a secondary path converging adaptive filter coefficient values obtaining process is carried out. I.e., the step, 2 difference path until a converged after operating an adaptive filter, said adaptive filter final convergence coefficient measuring process is performed, this value is 2 secondary path characteristics be utilized as substrate. Figure 6 3 2 showing frequency response characteristics measuring experiment about secondary path name of 2000. Each body characteristics such as frequency response values also 6 is connected some difference seen substrate. In the area of interest free directory experiment 2 a primary path and a characteristic difference characteristics, given headphone structure and core characteristic determined according the speaker and the microphone. Figure 6 shows a different measurement experiment however headphone also obtained when worn the same position indicating the secondary path frequency response experiment example 2 are disclosed. Next, in decision step (S30) 2 a primary path and a average coefficient, adaptive filter convergence coefficient values to obtain a difference average average coefficient 2 2 a primary path and a path determining process carried out. 2 average coefficient values of the decision step (S30) is supplied to all measuring values path difference data by the result of measurement of average 2 a primary path and determining a characteristic process are disclosed. In the embodiment of the present invention in one, each experiment about average value to obtain a difference average coefficient values of the adaptive filter coefficients is a primary path and a 2 2 tft3. adaptive filter path. Finally, adaptive filter (S40) initial value setting in a primary path and a 2, 2 average coefficient of the adaptive filter initial value setting process 2 a primary path and a secondary path carried out. After these procedures is performed, with active noise number anxiety operated when a question headphone, 2 2 initial value and average coefficient values are input of the adaptive filter a primary path and a secondary path, number of special operation system based on noise carried out. On the other hand, a question when deployed by a headphone, does not always formed in a normal listening position. If, wearing the headphone cap concave acoustic characteristic of varying method, secondary path 2 can be evaporation. If the primary path characteristics essentially 2 varies, the initial value is in an erroneous value normal wearing locations average primary path 2 acts rather convergence time can be increase. Figure 5 various matches the measured frequency response at or secondary path 2. But the underlying characteristics of frequency response depending on the position of the differences is shown wearing a slight difference does not occur. The initial value measured in normal listening position even when used secondary path 2 impact can be achieved. Figure 5 shows a measurement of experimental autoimmune headphone also send various locations i.e., normal position, in front of, behind, above, below normal position when worn away factor obtained 2 example experiment indicating the secondary path frequency response are disclosed. The present invention also 7 and also when using the initial value set by 2 Figure 8 shows a secondary path convergence performance efficiency by prior art compared to viewing surface are disclosed. More specifically, Figure 7 shows a normal wearing position also experiments measuring self headphone when worn in the embodiment example of the present invention acquired a conventional technique for testing an error value indicating operates and one drawing, Figure 8 experiments measuring self headphone diagonally in front of the present invention in the embodiment for example experiment error value obtained when worn for creating surface contains a conventional techniques one are disclosed. The reference also 7 and 8 also, headphone normal position without wearing and input 2 through route convergence speed can be improved and an indirectly-be difference. According to the present invention as detailed above, the headphone with active noise performance is enhanced initial operation control method of fixed number equal to or less than. In addition, the headphone 2 secondary path characteristics and directly measuring the applied feedback structure of active noise control method of fixed number, based on the final target value of the adaptive filter path difference measurement by setting the initial value in the vicinity of the 2, 2 a primary path of the adaptive filter convergence speed performance is enhanced initial operation control method of fixed number active noise is high and equal to or less. The present invention evaluates the above techniques of the present invention in a preferred embodiment is described with attached drawing but this example illustratively and not the across the previously described the present invention. In addition, the feature of the present invention conventional art if person with skill in the art various modifications within a range that the category of coated immunogen in a substantially vertical transfer are disclosed. S10: 2 a primary path and a adaptive filter operational phase S20: 2 a primary path and a adaptive filter convergence coefficient obtains S30: 2 a primary path and a average coefficient values of the decision step S40: 2 a primary path and a adaptive filter setting initial value The present invention relates to a method for initializing a secondary path filter in an active noise controller. According to the present invention, the method for setting an initial value for a secondary path adaptive filter in an active noise controller having a feedback structure applied to a headphone comprises: a secondary path adaptive filter operating step of allowing experimenters to operate a secondary path adaptive filter while wearing headphones; a secondary path adaptive filter convergence coefficient step of obtaining convergence coefficients of the secondary path adaptive filter when the secondary path adaptive filter converges; a secondary path average coefficient determining step of determining a secondary path average coefficient by calculating an average of the convergence coefficients of the secondary path adaptive filter; and a secondary path adaptive filter initial value setting step of setting the secondary path average coefficient as the initial value of the secondary path adaptive filter. According to the present invention, converging speed of the secondary path adaptive filter in the active noise controller increases and initial operation performance of the active noise controller improves. COPYRIGHT KIPO 2017 The headphone 2 feedback structure applied in setting the initial value of number of active noise violations of the adaptive filter path difference in method, measuring experiment 2 operating in wearing the headphone however adaptive filter operating step 2 a primary path and a secondary path adaptive filter; an adaptive filter is a primary path and said 2 2 2 converging adaptive filter coefficient values when converging adaptive filter convergence coefficient obtaining a primary path and a secondary path obtains; said 2 a primary path and a adaptive filter convergence coefficient values to obtain a difference average coefficient determining a value of a coefficient value 2 2 average path average primary path decision step; and said 2 said 2 average coefficient of the adaptive filter a primary path and a secondary path according to the initial value and input adaptive filter including a primary path 2, active noise number control method of fixed 2 difference path filter initialization method. According to Claim 1, said 2 a primary path and a adaptive filter operation step, said active noise number control method of fixed noise (off) in a state where the number would turn off, said 2 0 headphone set up the initial value of said difference path filter with speaker withdrawn by receiving signal, activating said 2 a primary path and a adaptive filter characterized, active noise number control method of fixed 2 difference path filter initialization method. According to Claim 2, characterized in that said learning signal is a white noise, active noise number control method of fixed 2 difference path filter initialization method.
