WO2020059977A1 - Réseau différentiel continûment orientable de microphones du second ordre et procédé pour le configurer - Google Patents

Réseau différentiel continûment orientable de microphones du second ordre et procédé pour le configurer Download PDF

Info

Publication number
WO2020059977A1
WO2020059977A1 PCT/KR2019/000576 KR2019000576W WO2020059977A1 WO 2020059977 A1 WO2020059977 A1 WO 2020059977A1 KR 2019000576 W KR2019000576 W KR 2019000576W WO 2020059977 A1 WO2020059977 A1 WO 2020059977A1
Authority
WO
WIPO (PCT)
Prior art keywords
response
microphone
microphone array
responses
cardioid
Prior art date
Application number
PCT/KR2019/000576
Other languages
English (en)
Korean (ko)
Inventor
이근상
이인호
박영철
변준
Original Assignee
엘지전자 주식회사
연세대학교 원주산학협력단
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 엘지전자 주식회사, 연세대학교 원주산학협력단 filed Critical 엘지전자 주식회사
Publication of WO2020059977A1 publication Critical patent/WO2020059977A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
    • H04R1/40—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by combining a number of identical transducers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones

Definitions

  • the present invention relates to a secondary differential microphone array (DMA) that can be continuously steered and a method for constructing the same. Specifically, the present invention relates to a secondary differential microphone array capable of continuously steering a directional direction while having higher directivity than a primary differential microphone array, and a method for constructing the same.
  • DMA secondary differential microphone array
  • a typical additive microphone array needs to consider various conditions such as the physical size of the microphone device and the length of the array suitable for a real environment. Due to these constraints, there are limitations in selecting an algorithm for beamformer design.
  • a differential microphone array is a structure that forms a beam using a spatial derivative of an acoustic pressure field, and can be implemented at a narrow microphone distance, making it an important option in voice communication applications. .
  • the value of usability can be increased by adjusting the main lobe of the DMA in the desired direction. Due to the nature of the DMA where the main lobe is formed in the end-fire direction, in order to adjust the main lobe in a desired direction, a microphone array should be arranged in the corresponding direction. Therefore, an algorithm that can continuously steer the directional direction is required even for a fixed microphone array arrangement.
  • the present invention is to provide an apparatus and a method for configuring a secondary differential microphone array to be continuously steerable, and calculating a secondary differential microphone array response steered in a given direction, so as to effectively increase the collection directivity using the microphone array do.
  • the present invention is to provide a noise canceling apparatus and method for calculating a secondary differential microphone array response steered in a given direction without generating a phase difference between each of the calculated responses.
  • a microphone array is configured according to a predetermined arrangement of 7 or 9 microphones, including one central microphone. Then, the secondary back-to-back cardioid responses are calculated using the input sound signals received from the respective microphones, and the unipolar response, the primary orthogonal dipole responses, and the secondary orthogonal dipole responses are calculated using the secondary back-to-back cardioid responses. Then, the secondary differential microphone array response steered by a given angle is calculated using unipolar response, primary orthogonal dipole responses, and secondary orthogonal dipole responses.
  • the second DMA algorithm is used compared to the conventionally steerable primary DMA, the direction of sound collection can be further increased, and a simple microphone array composed of only 7 or 9 microphones is optional. Steering is also possible in the direction of, so it can be downsized.
  • the calculated secondary DMA response is calculated. There is no phase difference between the responses, and thus there is an advantage of not having to perform an operation to correct a separate phase difference.
  • FIG. 1 is a block diagram showing a configuration of a secondary differential microphone array 100 that can be continuously steered according to an embodiment of the present invention.
  • FIG. 2 is a flowchart illustrating a method of configuring a secondary differential microphone array that can be continuously steered according to an embodiment of the present invention.
  • FIG 3 is a view showing a portion of a microphone array according to an embodiment of the present invention.
  • FIG. 4 is a view showing a first microphone array according to an embodiment of the present invention.
  • FIG. 5 is a view showing a second microphone array according to an embodiment of the present invention.
  • FIG. 6 is a view showing a third microphone array according to an embodiment of the present invention.
  • FIG. 7 is a view showing beam patterns of primary back-to-back cardioid responses according to an embodiment of the present invention.
  • FIG. 8 is a view showing a beam pattern of unipolar response according to an embodiment of the present invention.
  • FIG. 9 is a view showing a beam pattern of primary orthogonal dipole responses according to an embodiment of the present invention.
  • FIG. 10 is a view showing a beam pattern of a primary orthogonal dipole response steered according to an embodiment of the present invention.
  • FIG. 11 is a view showing a part of a beam pattern among secondary back-to-back cardioid responses according to an embodiment of the present invention.
  • FIG. 12 is a view showing a part of the beam pattern among the quadratic orthogonal dipole responses according to an embodiment of the present invention.
  • FIG. 13 is a view showing a beam pattern of a secondary orthogonal dipole response steered according to an embodiment of the present invention.
  • 14 to 17 are diagrams illustrating a beam pattern of a secondary DMA response steered according to an embodiment of the present invention.
  • FIG. 18 is a view showing a result of measuring a white noise gain using a continuously steerable secondary DMA according to an embodiment of the present invention.
  • FIG. 19 is a diagram showing a directional index using a continuously steerable secondary DMA according to an embodiment of the present invention.
  • FIG. 1 is a block diagram showing a configuration of a secondary differential microphone array 100 that can be continuously steered according to an embodiment of the present invention.
  • the terminal 100 may include a processor 110, an input unit 120, a memory 130, a communication unit 140, and a power supply unit 150.
  • the processor 110 controls the overall operation of the secondary differential microphone array 100, which is typically continuously steerable.
  • the processor 110 may provide or process appropriate information or functions to a user by processing signals, data, information, etc. input or output through the following components or by driving an application program stored in the memory 130.
  • the processor 110 may control at least some of the components illustrated in FIG. 1 to drive an application program stored in the memory 130. Furthermore, the processor 110 may operate by combining at least two or more of the components included in the secondary differential microphone array 100 that can be continuously steered to drive the application program.
  • the processor may refer to a data processing device embedded in hardware having physically structured circuits, for example, to perform functions represented by codes or instructions included in a program.
  • a data processing device embedded in hardware a microprocessor, a central processing unit (CPU), a processor core, a multiprocessor, and an application-specific integrated ASIC circuit), a field programmable gate array (FPGA), and the like, but the scope of the present invention is not limited thereto.
  • the input unit 120 receives the ambient sound and includes a microphone array 121 composed of a plurality of fixed microphones.
  • the microphone array 121 may include 7 or 9 microphones on the same plane.
  • the microphone array 121 may be composed of MEMS (Micro Electro-Mechanical Systems) microphones. Since the MEMS microphone is small, it is possible to miniaturize the microphone array 121.
  • MEMS Micro Electro-Mechanical Systems
  • the microphones included in the microphone array 121 are arranged with narrow intervals, so that the lengths of the horizontal and vertical sides of the microphone array 121 may be smaller than the wavelength of the sound source in the audible frequency band.
  • the memory 130 stores data supporting various functions of the secondary differential microphone array 100 that can be continuously steered.
  • the memory 130 is for a plurality of applications (application programs or applications) driven in the continuously steerable secondary differential microphone array 100, for the operation of the continuously steerable secondary differential microphone array 100. Data, instructions can be stored.
  • the memory 130 may separately store and store sound signals received from microphones included in the microphone array 121.
  • the stored sound signals can be stored temporarily or permanently.
  • the communication unit 140 may transmit and receive data to and from a device using a sound signal such as a microphone array, a speaker, or a sound signal processing device through wired or wireless communication.
  • a sound signal such as a microphone array, a speaker, or a sound signal processing device through wired or wireless communication.
  • the power supply 150 supplies power to each component included in the secondary differential microphone array 100 that is continuously steerable by receiving external power and internal power.
  • the power supply 150 includes a battery, and the battery may be a built-in battery or a replaceable battery.
  • FIG. 2 is a flowchart illustrating a method of configuring a secondary differential microphone array that can be continuously steered according to an embodiment of the present invention.
  • the processor 110 of the secondary differential microphone array 100 that can be continuously steered receives input sound signals through the microphone array 121 composed of a plurality of microphones (S201).
  • the microphone array 121 can be classified according to the number of the plurality of microphones constituting and the arrangement thereof, and the present invention proposes a total of three microphone arrays.
  • the first microphone array is composed of nine microphones, and a detailed description thereof will be described with reference to FIG. 4.
  • the second microphone array is composed of nine microphones, and a detailed description thereof will be described with reference to FIG. 5.
  • the third microphone array is composed of seven microphones, and a detailed description thereof will be described with reference to FIG. 6.
  • the continuously steerable primary DMA uses a microphone array composed of four microphones as shown in FIG. 3, but in the present invention, a microphone array composed of seven or nine microphones to continuously steer the secondary DMA To use.
  • FIG 3 is a view showing a portion of a microphone array according to an embodiment of the present invention.
  • a primary steerable DMA in order to configure a continuously steerable secondary DMA, a primary steerable DMA must first be constructed, which is a microphone array composed of four microphones 121_1, 121_2, 121_3 and 121_4 ( 121).
  • Each of the microphones 121_1, 121_2, 121_3 and 121_4 is disposed in the same plane (eg, xy plane).
  • the first microphone pair 121_1 and 121_2 is arranged on the x-axis
  • the second microphone pair 121_3 and 121_4 is arranged on the y-axis. That is, the first microphone pair and the second microphone pair are disposed perpendicular to each other in the same plane.
  • Each of the microphones 121_1, 121_2, 121_3, and 121_4 is arranged to be separated by an equal distance d / 2 from the origin. That is, the microphones included in each microphone pair are arranged to be separated from each other by a distance d.
  • the distance d between the microphones must satisfy the condition of Equation 1 below.
  • ⁇ is the wavelength of the sound source.
  • the distance d between the microphones is not a distance between all microphones, but a reference of a distance between microphones that are grouped into one group or set.
  • d when viewing the first microphone pair 121_1 and 121_2 as one set, d may mean a distance between the first microphone 121_1 and the second microphone 121_2.
  • d is the first microphone 121_1 and the central microphone. It may mean a distance between (121_0) and a distance between the central microphone (121_0) and the second microphone (121_2).
  • the microphone array 121 is configured such that the distance between microphones included in the same microphone pair is much smaller than half the wavelength of the sound source to be input. For example, it may be configured to be smaller than half the wavelength of sound in the audible frequency band.
  • ⁇ m is the normalized monopole response
  • D 1 is the normalized 1 st- order response with the directional direction steered to ⁇ s .
  • a 1,1 and a 1,2 are coefficients that determine directivity, and the sum of a 1,1 and a 1,2 is 1.
  • ⁇ is the angle from the reference axis (eg, x-axis) in the microphone array plane (xy plane).
  • the normalized primary DMA response in which the directional direction is steered can be expressed as a weighted sum of the normalized unipolar response and the normalized primary dipole response in which the directional direction is steered.
  • the unipolar response ⁇ m ( ⁇ ) sums sound signals input from all the microphones 121_1, 121_2, 121_3, and 121_4, or the primary back-to-back cardioid. It can be composed of the sum of responses.
  • ⁇ 1, x ( ⁇ ) is the primary x-axis orthogonal dipole response (or first primary orthogonal dipole response) obtained from the first microphone pair 121_1 and 121_2, and ⁇ 1, y ( ⁇ ) is the second Primary y-axis orthogonal dipole response (or second primary orthogonal dipole response) obtained from microphone pairs 121_3 and 121_4.
  • the first primary orthogonal dipole response and the second primary orthogonal dipole response are as follows: [Equation 4] and [Equation 5] Can be expressed as ⁇ 0 is d / c, c is the speed of sound, and ⁇ is the angular frequency.
  • the first primary orthogonal dipole response and the second primary orthogonal dipole response are as follows. Equation 6] and [Equation 7].
  • ⁇ 0 is d / c
  • c is the speed of sound
  • ⁇ is the angular frequency.
  • the first dipole response D 1 ( ⁇ , ⁇ s ) that can be steered at any angle is required.
  • a secondary dipole response D 2 ( ⁇ , ⁇ s ) that can be steered at any angle is required.
  • a normalized 2nd DMA response in which the directional direction according to an embodiment of the present invention is steered by ⁇ s from a reference axis (eg, x-axis) is normalized 2 nd -order DMA response) R 2 may be approximated as in [Equation 8] below.
  • a 2,1 , a 2,2 and a 2,3 are coefficients for determining directivity, and the sum of a 2,1 , a 2,2 and a 2,3 is 1.
  • the second dipole response is expressed as [Equation 9] to [Equation 11] using [Equation 3].
  • x ( ⁇ ) is the secondary x-axis orthogonal dipole response (or first secondary quadrature dipole response) obtained from the origin microphone 121_0 and the first microphone pair 121_1 and 121_2, and ⁇ 2, y ( ⁇ ) is the secondary y-axis orthogonal dipole response (or second secondary orthogonal dipole response) obtained from the origin microphone 121_0 and the second microphone pair 121_3 and 121_4.
  • Equation 9 the last term is expressed as a product of the first primary orthogonal dipole response and the second primary orthogonal dipole response.
  • ⁇ 2, + q ( ⁇ ) is a second-order orthogonal dipole response in a 45-degree direction from a reference axis (x-axis), which can be referred to as a third secondary orthogonal dipole response.
  • ⁇ 2, -q ( ⁇ ) is a quadratic orthogonal dipole response in the -45 degree direction from the reference axis (x-axis), which is referred to as a fourth quadratic orthogonal dipole response. You can.
  • the present invention revealed that the product of two primary orthogonal dipole responses can be expressed as the difference between the third orthogonal dipole response and the fourth secondary orthogonal dipole response using the triangular law.
  • the present invention can be configured to continuously steer secondary DMA by using the microphone array 121 in which additional microphones 121_5 to 121_8 are arranged in accordance with the meanings of [Equation 16] and [Equation 17]. It showed that there is. This will be described in detail with reference to FIG. 4 below.
  • FIG. 4 is a view showing a first microphone array according to an embodiment of the present invention.
  • the first microphone array illustrated in FIG. 4 is a microphone array corresponding to Equations 16 and 17 above.
  • microphones are arranged to match the meaning of the equation derived through mathematical induction.
  • the first microphone array includes nine microphones 121_0 to 121_8 in the same microphone array plane (eg, xy plane).
  • the central microphone 121_0 is arranged at the origin of the microphone array.
  • the first pair of microphones 121_1 and 121_2 are arranged on the x-axis
  • the second pair of microphones 121_3 and 121_4 are arranged on the y-axis
  • the first microphone pair and the second microphone pair are arranged perpendicular to each other in the same plane, and the third microphone pair and the fourth microphone pair are arranged perpendicular to each other in the same plane.
  • the microphones included in each microphone pair are symmetrically arranged based on the central microphone 121_0.
  • the first microphone 121_1 and the second microphone 121_2 included in the first microphone pair are symmetrically arranged with respect to each other with respect to the central microphone 121_0.
  • the first to fourth microphones 121_1 to 121_4 are arranged at the same distance d from the central microphone 121_0, and the fifth to eighth microphones 121_5 to 121_8 are the same distance from the central microphone 121_0. As far as it is placed.
  • the secondary DMA response steered according to an embodiment of the present invention can be expressed by arranging [Equation 8] and [Equation 18] below.
  • the secondary DMA response steered at an arbitrary angle may be calculated using the unipolar response, the primary dipole responses, and the secondary dipole responses obtained using the first microphone array. .
  • FIG. 5 is a view showing a second microphone array according to an embodiment of the present invention.
  • the second microphone array shown in FIG. 5 is a microphone array including nine microphones constructed according to an approximate equation when the assumption of [Equation 1] holds.
  • the microphones 121_1 to 121_8 except the central microphone 121_0 May be disposed on concentric circles so as to be separated by the same distance d from the central microphone 121_0.
  • the second microphone array includes nine microphones 121_0 to 121_8 in the same microphone array plane (eg, xy plane).
  • the central microphone 121_0 is arranged at the origin of the microphone array.
  • the first pair of microphones 121_1 and 121_2 are arranged on the x-axis
  • the second pair of microphones 121_3 and 121_4 are arranged on the y-axis
  • the first microphone pair and the second microphone pair are arranged perpendicular to each other in the same plane, and the third microphone pair and the fourth microphone pair are arranged perpendicular to each other in the same plane.
  • the microphones included in each microphone pair are symmetrically arranged based on the central microphone 121_0.
  • the first microphone 121_1 and the second microphone 121_2 included in the first microphone pair are symmetrically arranged with respect to each other with respect to the central microphone 121_0.
  • the first to eighth microphones 121_1 to 121_8 are disposed at the same distance d from the central microphone 121_0.
  • the secondary DMA response steered at an arbitrary angle may be calculated using the unipolar response, the primary dipole responses, and the secondary dipole responses obtained using the second microphone array.
  • FIG. 6 is a view showing a third microphone array according to an embodiment of the present invention.
  • the third microphone array shown in FIG. 6 is a microphone array including seven microphones constructed according to an equation approximating [Equation 15].
  • Equation 15 may be approximated to [Equation 26] using the approximated [Equation 20] to [Equation 25].
  • the third microphone array is from the x-axis in the second microphone array of FIG. 5 as shown in FIG. It may be configured by excluding the seventh microphone 121_7 in the 45 degree direction and the eighth microphone 121_8 in the 135 degree direction.
  • Equation 18 may be summarized as [Equation 27] using [Equation 26].
  • the third microphone array includes seven microphones 121_0 to 121_6 in the same microphone array plane (eg, xy plane).
  • the central microphone 121_0 is arranged at the origin of the microphone array.
  • the first pair of microphones 121_1 and 121_2 are arranged on the x-axis
  • the second pair of microphones 121_3 and 121_4 are arranged on the y-axis
  • the first microphone pair and the second microphone pair are disposed perpendicular to each other in the same plane.
  • the microphones included in each microphone pair are symmetrically arranged based on the central microphone 121_0.
  • the first microphone 121_1 and the second microphone 121_2 included in the first microphone pair are symmetrically arranged with respect to each other with respect to the central microphone 121_0.
  • the first to sixth microphones 121_1 to 121_6 are disposed at the same distance d from the central microphone 121_0.
  • the secondary DMA response steered at an arbitrary angle may be calculated using the unipolar response, the primary dipole responses, and the secondary dipole responses obtained using the third microphone array. .
  • a second DMA that can be continuously steered can be configured using the first to third microphone arrays.
  • the processor 110 of the continuously steerable secondary differential microphone array 100 responds to a 2nd-order back-to-back cardioid using input sound signals. Calculate them (S203).
  • the unipolar response and the dipole response are configured using the secondary back-to-back cardioid responses.
  • the second back-to-back cardioid responses are calculated.
  • ⁇ means the direction (front or back) of the cardioid.
  • the processor 110 calculates secondary back-to-back cardioid responses from the combination of each microphone pair and the central microphone 121_0.
  • the processor 110 calculates the first differential signal by subtracting the zero input signal obtained from the central microphone 121_0 from the first input signal obtained from the first microphone 121_1, and the second microphone ( 121_2) to calculate the first secondary back-to-back cardioid response by subtracting the second input signal.
  • the processor 110 calculates the second differential signal by subtracting the zero input signal obtained from the central microphone 121_0 from the second input signal obtained from the second microphone 121_2, and the first microphone ( 121_1) subtract the first input signal obtained to calculate a second secondary back-to-back cardioid response.
  • the processor 110 calculates the third differential signal by subtracting the zero input signal obtained from the central microphone 121_0 from the third input signal obtained from the third microphone 121_3, and the fourth microphone ( 121_4) subtract the fourth input signal to calculate the third secondary back-to-back cardioid response.
  • the processor 110 calculates the fourth differential signal by subtracting the zero input signal obtained from the central microphone 121_0 from the fourth input signal obtained from the fourth microphone 121_4, and the third microphone ( 121_3) to calculate the fourth secondary back-to-back cardioid response by subtracting the third input signal.
  • the processor 110 calculates a fifth differential signal by subtracting the zeroth input signal obtained from the central microphone 121_0 from the fifth input signal obtained from the fifth microphone 121_5, and from the fifth differential signal to the sixth microphone ( 121_6) subtract the sixth input signal to calculate the fifth secondary back-to-back cardioid response.
  • the processor 110 calculates the sixth differential signal by subtracting the zeroth input signal obtained from the central microphone 121_0 from the sixth input signal obtained from the sixth microphone 121_6, and the fifth microphone from the sixth differential signal ( The fifth input signal obtained in 121_5) is subtracted to calculate the sixth secondary back-to-back cardioid response.
  • the processor 110 calculates the seventh differential signal by subtracting the zeroth input signal obtained from the central microphone 121_0 from the seventh input signal obtained from the seventh microphone 121_7, and the eighth microphone from the seventh differential signal ( 121_8) to calculate the 7th 2nd back-to-back cardioid response by subtracting the 8th input signal.
  • the processor 110 calculates the eighth difference signal by subtracting the zeroth input signal obtained from the central microphone 121_0 from the eighth input signal obtained from the eighth microphone 121_8, and the seventh microphone ( Subtract the seventh input signal obtained in 121_7) to calculate the eighth secondary back-to-back cardioid response.
  • the processor 110 When the processor 110 acquires input sound signals from the first microphone array or the second microphone array, the processor 110 has a total of eight secondary back-to-back cardioid responses (first to eighth second back-to-back cardioid responses) Calculate
  • the processor 110 calculates a total of six secondary back-to-back cardioid responses (first to sixth second back-to-back cardioid responses).
  • the processor 110 of the continuously steerable secondary differential microphone array 100 calculates a monopole response using secondary back-to-back cardioid responses (S205).
  • the processor 110 may calculate a unipolar response using the calculated second back-to-back cardioid responses.
  • the processor 110 may calculate a unipolar response by summing all of the calculated second back-to-back cardioid responses.
  • the processor 110 combines the first secondary back-to-back cardioid response, the second secondary back-to-back cardioid response, the third secondary back-to-back cardioid response, and the fourth secondary back-to-back cardioid response as a single-pole response. Can be calculated.
  • the processor 110 of the continuously steerable secondary differential microphone array 100 calculates primary 1st-order orthogonal dipole responses using secondary back-to-back cardioid responses (S207).
  • the processor 110 may calculate primary orthogonal dipole responses using the calculated secondary back-to-back cardioid responses.
  • the processor 110 may calculate the primary orthogonal dipole responses by subtracting the calculated secondary back-to-back cardioid responses.
  • the processor 110 may calculate primary orthogonal dipole responses by subtracting each other from the calculated second back-to-back cardioid responses, which correspond to directions of the second back-to-back cardioid.
  • the meaning that the directions correspond means that the directions are 180 degrees apart from each other.
  • the processor 110 may calculate first orthogonal dipole responses by subtracting the first to fourth secondary back-to-back cardioid responses in the x-axis and y-axis directions from among the calculated secondary back-to-back cardioid responses.
  • the processor 110 may calculate the primary orthogonal dipole responses as shown in [Equation 33].
  • the processor 110 calculates the first primary orthogonal dipole response by subtracting the second secondary back-to-back cardioid response from the first secondary back-to-back cardioid response, and the fourth secondary back-to-back cardioid response from the third secondary back-to-back cardioid response Subtracting, we can calculate the second primary orthogonal dipole response.
  • the processor 110 of the continuously steerable secondary differential microphone array 100 calculates 2nd-order orthogonal dipole responses using secondary back-to-back cardioid responses (S209).
  • the processor 110 may calculate secondary quadrature dipole responses using the calculated second-to-back cardioid responses.
  • the processor 110 may calculate the secondary orthogonal dipole responses by summing the calculated secondary back-to-back cardioid responses.
  • the processor 110 may calculate primary orthogonal dipole responses by summing the second back-to-back cardioid responses corresponding to each other among the calculated second-to-back cardioid responses.
  • the meaning that the directions correspond means that the directions are 180 degrees apart from each other.
  • the processor 110 may calculate quadratic orthogonal dipole responses as shown in Equation 34 below.
  • the processor 110 calculates the first second orthogonal dipole response by adding the first second back-to-back cardioid response and the second second back-to-back cardioid response, and the third second back-to-back cardioid response and the fourth second back-to-back cardioid response.
  • Adds to calculate the 2nd quadrature orthogonal dipole response adds the 5th 2nd back-to-back cardioid response and the 6th 2nd back-to-back cardioid response, calculates the 3rd 2nd orthogonal dipole response, and the 7th 2nd back-to-back cardioid response 8
  • the fourth quadratic orthogonal dipole response can be calculated by summing the quadratic back-to-back cardioid responses.
  • the processor 110 may calculate first to fourth second orthogonal dipole responses.
  • the processor 110 may calculate only the first to third second orthogonal dipole responses.
  • the processor 110 calculates the unipolar response, the first orthogonal dipole responses, and the second orthogonal dipole responses by combining the second back-to-back cardioid responses, thereby obtaining the second DMA response steered according to Equation (8). It is possible to solve the problem of phase mismatch of unipolar responses, primary orthogonal dipole responses, and secondary orthogonal dipole responses used for calculation.
  • the continuously steerable secondary DMA according to an embodiment of the present invention does not have a problem of phase mismatch between calculated responses without a process for matching phases separately.
  • the processor 110 of the continuously steerable secondary differential microphone array 100 calculates a secondary DMA response steered by a given steering angle using unipolar response, primary orthogonal dipole responses, and secondary orthogonal dipole responses ( S211).
  • the processor 110 may calculate a secondary DMA response steered by a given steering angle ⁇ s from a unipolar response, primary orthogonal dipole responses, and secondary orthogonal dipole responses calculated according to Equation (8).
  • the steering angle ⁇ s has a range of 0 degrees to 360 degrees, and may be a value set by a user or automatically. That is, a given angle is not limited to a fixed value, but refers to an arbitrary angle from 0 to 360 degrees, so the feature of the present invention is that it can calculate a secondary DMA response steered by any desired angle. .
  • the steering angle ⁇ s may mean an angle in a direction corresponding to a position of a sound source that makes a sound to be collected through the microphone array 121.
  • the steering angle ⁇ s may be 30 degrees.
  • the steering angle ⁇ s may be that the processor 110 analyzes the input voice signals to calculate the position or direction of the sound source, and sets the calculated position or direction angle of the sound source.
  • the processor 110 may set the steering angle ⁇ s to 60 degrees when analyzing the input voice signals and determining that the current sound source direction is in the 60 degree direction based on the x-axis.
  • the processor 110 when the processor 110 recognizes the user's starting word from the input voice signals, the processor 110 calculates the position or direction from which the user issued the starting word, and the steering angle ⁇ s as the calculated angle of the user's position or direction Can be set. For example, the processor 110 may set the steering angle to 90 degrees when the user analyzes input voice signals including the starting word and determines that the location where the user issues the starting word is 90 degrees based on the x-axis.
  • the processor 110 may have a unipolar response, primary orthogonal dipole responses, and secondary quadrature calculated according to Equation 18 above. From the dipole responses it is possible to calculate a secondary DMA response steered by a given steering angle (or desired steering angle) ⁇ s .
  • the processor 110 may include a calculated unipolar response; A primary orthogonal dipole response steered by ⁇ s calculated from the first and second primary orthogonal dipole responses; And a secondary orthogonal dipole response steered by ⁇ s calculated from the first to fourth secondary orthogonal dipole responses to calculate a secondary DMA response steered by ⁇ s .
  • the processor 110 is given from the unipolar response, primary orthogonal dipole responses, and secondary orthogonal dipole responses calculated according to Equation 27 above.
  • the secondary DMA response steered by the steering angle (or desired steering angle) ⁇ s can be calculated.
  • the processor 110 when the structure of the microphone array 121 is a third microphone array, the processor 110 includes a calculated unipolar response; A primary orthogonal dipole response steered by ⁇ s calculated from the first and second primary orthogonal dipole responses; And a secondary orthogonal dipole response steered by ⁇ s calculated from the first to third secondary orthogonal dipole responses to calculate a secondary DMA response steered by ⁇ s .
  • calculating the unipolar response (S205), calculating the primary orthogonal dipole responses (S207) and calculating the secondary orthogonal dipole responses (S209) are performed in parallel with each other or are performed The order can be reversed.
  • FIG. 7 is a view showing beam patterns of primary back-to-back cardioid responses according to an embodiment of the present invention.
  • FIG. 7 shows four primary back-to-back cardioid responses obtained using the first microphone pair 121_1 and 121_2 and the second microphone pair 121_3 and 121_4.
  • the primary back-to-back cardioid response in the 0 degree (x-axis) direction is the first primary back-to-back cardioid response 701
  • the primary back-to-back cardioid response in the 180 degree (-x-axis) direction is the second primary back-to-back cardioid response.
  • the first back-to-back cardioid response in the 270-degree (-y-axis) direction to the fourth primary back-to-back This is called cardioid response 704.
  • the processor 110 calculates the first primary back-to-back cardioid response 701 by subtracting the input signal of the second microphone 121_2 from the input signal of the first microphone 121_1, and from the input signal of the second microphone 121_2.
  • the second primary back-to-back cardioid response 702 may be calculated by subtracting the input signal of the first microphone 121_1.
  • the processor 110 calculates the third primary back-to-back cardioid response 703 by subtracting the input signal of the fourth microphone 121_4 from the input signal of the third microphone 121_3, and inputs the fourth microphone 121_4
  • the fourth primary back-to-back cardioid response 704 may be calculated by subtracting the input signal of the third microphone 121_3 from the signal.
  • FIG. 8 is a view showing a beam pattern of unipolar response according to an embodiment of the present invention.
  • the processor 110 may include a first primary back-to-back cardioid response 701, a second primary back-to-back cardioid response 702, and a third primary back-to-back cardioid response 703 and 4
  • the unipolar response 801 can be calculated by summing all the primary back-to-back cardioid responses 704.
  • FIG. 9 is a view showing a beam pattern of primary orthogonal dipole responses according to an embodiment of the present invention.
  • FIG. 9 uses the first primary orthogonal dipole response 901 in the 0 degree (x-axis) direction obtained using the first microphone pair 121_1 and 121_2 and the second microphone pair 121_3 and 121_4.
  • the second primary orthogonal dipole response 902 in the 90-degree (y-axis) direction obtained is illustrated.
  • the processor 110 subtracts the second primary back-to-back cardioid response 702 from the first primary back-to-back cardioid response 701 to calculate a first primary orthogonal dipole response (0 degree direction or x-axis direction, 901),
  • the second primary orthogonal dipole response (90-degree direction or y-axis direction, 902) may be calculated by subtracting the fourth primary back-to-back cardioid response 704 from the third primary back-to-back cardioid response 703.
  • FIG. 10 is a view showing a beam pattern of a primary orthogonal dipole response steered according to an embodiment of the present invention.
  • FIG. 10 illustrates a primary orthogonal dipole response in which the direction of directivity is steered 60 degrees relative to a reference axis (x-axis) using a unipolar response, a first primary orthogonal dipole response, and a second primary orthogonal dipole response.
  • the processor 110 may obtain a primary orthogonal dipole response in which the direction of directivity is steered at an arbitrary angle through operations on a unipolar response, a first primary orthogonal dipole response, and a second primary orthogonal dipole response.
  • FIG. 11 is a view showing a part of a beam pattern among secondary back-to-back cardioid responses according to an embodiment of the present invention.
  • FIG. 11 shows four secondary back-to-back cardioid responses obtained using the first microphone pair 121_1 and 121_2, the second microphone pair 121_3 and 121_4, and the central microphone 121_0.
  • the second back-to-back cardioid response in the 0 degree (x-axis) direction is the first second back-to-back cardioid response 1101
  • the second back-to-back cardioid response in the 180-degree (-x-axis) direction is the second second back-to-back cardioid response.
  • (1102) a second back-to-back cardioid response in the 90-degree (y-axis) direction
  • a third second-to-back cardioid response (1103)
  • the second back-to-back cardioid response is referred to as the seventh second back-to-back cardioid response and the second back-to-back cardioid response in the direction of 315 degrees is the eighth second back-to-back cardioid response.
  • the processor 110 calculates the first differential signal by subtracting the zeroth input signal obtained from the central microphone 121_0 from the first input signal obtained from the first microphone 121_1, and the first differential signal Subtract the second input signal obtained from the second microphone 121_2 to calculate the first secondary back-to-back cardioid response 1101.
  • the processor 110 calculates the second differential signal by subtracting the zero input signal obtained from the central microphone 121_0 from the second input signal obtained from the second microphone 121_2, and the first microphone ( 121_1), the second input back-to-back cardioid response 1102 is calculated by subtracting the first input signal.
  • the processor 110 calculates the third differential signal by subtracting the zero input signal obtained from the central microphone 121_0 from the third input signal obtained from the third microphone 121_3, and the fourth microphone ( 121_4) is subtracted to calculate the third secondary back-to-back cardioid response 1103.
  • the processor 110 calculates the fourth differential signal by subtracting the zero input signal obtained from the central microphone 121_0 from the fourth input signal obtained from the fourth microphone 121_4, and the third microphone ( 121_3) to calculate the fourth secondary back-to-back cardioid response 1104 by subtracting the third input signal.
  • the processor 110 calculates a fifth differential signal by subtracting the zeroth input signal obtained from the central microphone 121_0 from the fifth input signal obtained from the fifth microphone 121_5, and from the fifth differential signal to the sixth microphone ( 121_6) to calculate the fifth secondary back-to-back cardioid response 1105 by subtracting the sixth input signal.
  • the processor 110 calculates the sixth difference signal by subtracting the zeroth input signal obtained from the central microphone 121_0 from the sixth input signal obtained from the sixth microphone 121_6, and the fifth microphone from the sixth difference signal ( 121_5), the sixth second back-to-back cardioid response 1106 is calculated by subtracting the fifth input signal.
  • the processor 110 calculates a seventh difference signal by subtracting the zeroth input signal obtained from the central microphone 121_0 from the seventh input signal obtained from the seventh microphone 121_7, and the eighth microphone ( 121_8) to calculate the seventh secondary back-to-back cardioid response 1107 by subtracting the eighth input signal.
  • the processor 110 calculates the eighth difference signal by subtracting the zeroth input signal obtained from the central microphone 121_0 from the eighth input signal obtained from the eighth microphone 121_8, and the seventh microphone ( The 7th input signal obtained in 121_7) is subtracted to calculate the 8th 2nd back-to-back cardioid response 1108.
  • the processor 110 includes a first secondary back-to-back cardioid response 1101, a second secondary back-to-back cardioid response 1102, a third secondary back-to-back cardioid response 1103, and a fourth secondary back-to-back shown in FIG.
  • the unipolar response can be calculated by summing all the cardioid responses 1104.
  • FIG. 12 is a view showing a part of the beam pattern among the quadratic orthogonal dipole responses according to an embodiment of the present invention.
  • FIG. 12 shows a first quadratic orthogonal dipole response 1201 in a 0 degree (x-axis) direction obtained using the first microphone pair 121_1 and 121_2 and the central microphone 121_0, and the second microphone pair ( 121_3 and 121_4) and a second secondary orthogonal dipole response 1202 in a 90 degree (y-axis) direction obtained using the central microphone 121_0.
  • the processor 110 calculates a first second orthogonal dipole response (0 degree direction or x-axis direction, 1201) by adding the first second back-to-back cardioid response 1101 and the second second back-to-back cardioid response 1102,
  • the second secondary orthogonal dipole response (90-degree direction or y-axis direction, 1202) may be calculated by adding the third secondary back-to-back cardioid response 1103 and the fourth secondary back-to-back cardioid response 1104.
  • the processor 110 calculates a third second orthogonal dipole response (45-degree direction) by adding the fifth second back-to-back cardioid response and the sixth second back-to-back cardioid response, and the seventh second
  • the fourth second orthogonal dipole response (135 degree direction) may be calculated by adding the second back to back cardioid response and the eighth second back to back cardioid response.
  • FIG. 13 is a view showing a beam pattern of a secondary orthogonal dipole response steered according to an embodiment of the present invention.
  • FIG. 13 shows a quadratic orthogonal dipole response in which the direction of directivity is steered 60 degrees relative to the reference axis (x-axis).
  • the processor 110 is a quadratic orthogonal dipole that steers the direction of directivity at an arbitrary angle through calculations on a unipolar response, a first secondary orthogonal dipole response, a second secondary orthogonal dipole response, and a third secondary orthogonal dipole response. You can get a response.
  • the processor 110 determines the direction of directionality through operations on the unipolar response, the first secondary orthogonal dipole response, the second secondary orthogonal dipole response, the third secondary orthogonal dipole response, and the fourth secondary orthogonal dipole response. Secondary orthogonal dipole responses steered at any angle can be obtained.
  • the unipolar response may be calculated as a sum of four primary back-to-back cardioid responses, but may be calculated as a sum of four secondary back-to-back cardioid responses.
  • the processor 110 calculates a unipolar response by summing the first secondary back-to-back cardioid response, the second secondary back-to-back cardioid response, the third secondary back-to-back cardioid response, and the fourth secondary back-to-back cardioid response, and calculates the unipolar response thus calculated. Can be used to compute the quadratic orthogonal dipole response steering at any angle.
  • 14 to 17 are diagrams illustrating a beam pattern of a secondary DMA response steered according to an embodiment of the present invention.
  • the beam pattern of any secondary DMA is substantially constant regardless of the steering angle.
  • FIGS. 14 to 17 show the secondary DMA response in the case where the microphone array 121 has the 7-microphone structure shown in FIG. 5 above. That is, it can be confirmed that even in the 7-microphone structure having the most approximation among the embodiments of the present invention, the change in the shape of the beam pattern is very small as the steering angle is adjusted.
  • FIG. 18 is a view showing a result of measuring a white noise gain using a continuously steerable secondary DMA according to an embodiment of the present invention.
  • WNG white noise gain
  • Ideal represents the reference value of WNG
  • Direct is WNG when the microphone array 121 has the 9-microphone structure shown in FIG. 3 (first microphone array)
  • 9-mic Config is the microphone array 121.
  • WNG, 7-mic Config in the case of having a 9-microphone structure shown in 4 (second microphone array), the case where the microphone array 121 has a 7-microphone structure shown in FIG. 5 (third microphone array) It is WNG when I have it.
  • the first microphone array is a microphone array that has not been subjected to an approximation process, shows a relatively low WNG when compared to the structure of other microphone arrays, and a relatively large change in WNG with respect to a change in steering angle ( ⁇ s ). This is a result derived because the distance between the same microphones is not guaranteed.
  • the second microphone array is a microphone array having a 9-microphone structure that has undergone an approximation process, maintains a consistently high WNG, and exhibits small variation in WNG with respect to a change in steering angle ⁇ s .
  • the third microphone array is a microphone array having a 7-microphone structure that has been subjected to an approximation process, and generally has a high WNG, but when the steering angle ⁇ s is - ⁇ / 4 and + 3 ⁇ / 4, the WNG decreases rapidly. This is due to the omission of the dipole component in the - ⁇ / 4 direction (-45 degree direction) through the approximation process.
  • the third microphone array has a loss of 2dB of WNG compared to the second microphone array at some steering angles, it is cheaper and more efficient than the microphone arrays of other structures in practical implementation because the number of microphones required for implementation is the smallest. However, if performance is a top priority, it is most effective to use a second microphone array.
  • the fluctuation range of the WNG in FIG. 18 is within about 2 dB, which means that despite the change in the steering angle, the deviation of the WNG is considerably small and has excellent performance.
  • FIG. 19 is a diagram showing a directional index using a continuously steerable secondary DMA according to an embodiment of the present invention.
  • DI directivity index
  • DI is generally calculated by [Equation 35] below, and B is a beam pattern.
  • [Equation 36] is an equation for calculating DI from the continuously steerable secondary DMA response according to an embodiment of the present invention.
  • DI is a value obtained by dividing the power of the beam at a specific steering angle by the power of the entire beam pattern, and is an index indicating the performance of directivity.
  • the continuously steerable secondary DMA composed of a first microphone array, a second microphone array, or a third microphone array according to an embodiment of the present invention all has a variation of DI within 0.1 dB.
  • the directivity maintains a constant level and has excellent performance.
  • the continuously steerable secondary DMA composed of the first microphone array, the second microphone array, or the third microphone array continuously maintains the secondary DMA response while maintaining the shape of the beam pattern. Steering at an angle is possible. In addition, the directionality or white noise gain fluctuation according to the steering is kept small, and high performance can be expected.
  • the secondary DMA is used in comparison with the conventional continuously steerable primary DMA, there is an advantage in that steering can be continuously performed while maintaining more stable performance while being more directional.
  • the above-described present invention can be embodied as computer readable codes on a medium on which a program is recorded.
  • the computer-readable medium includes any kind of recording device in which data readable by a computer system is stored. Examples of computer-readable media include a hard disk drive (HDD), solid state disk (SSD), silicon disk drive (SDD), ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage device. There is this.
  • the computer may include a processor 180 of the terminal.
  • the display device described above is not limited to the configuration and method of the above-described embodiments, and the above embodiments may be configured by selectively combining all or part of each embodiment so that various modifications can be made. It might be.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Circuit For Audible Band Transducer (AREA)

Abstract

La présente invention concerne, selon un mode de réalisation, un réseau différentiel orientable de microphones du second ordre, le réseau comportant: une unité d'entrée servant à recevoir une pluralité de signaux sonores d'entrée par l'intermédiaire d'un réseau de microphones comprenant une pluralité de microphones disposés de façon fixe sur un plan; et un processeur servant à calculer des réponses du second ordre en cardioïdes dos à dos en utilisant la pluralité de signaux sonores d'entrée, à calculer une réponse unipolaire, des réponses de dipôle orthogonal du premier ordre, et des réponses de dipôle orthogonal du second ordre en utilisant les réponses du second ordre en cardioïdes dos à dos, et à calculer une réponse de DMA du second ordre orientée suivant un angle donné en utilisant la réponse unipolaire, les réponses de dipôle orthogonal du premier ordre, et les réponses de dipôle orthogonal du second ordre.
PCT/KR2019/000576 2018-09-21 2019-01-15 Réseau différentiel continûment orientable de microphones du second ordre et procédé pour le configurer WO2020059977A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR20180114423 2018-09-21
KR10-2018-0114423 2018-09-21

Publications (1)

Publication Number Publication Date
WO2020059977A1 true WO2020059977A1 (fr) 2020-03-26

Family

ID=69887347

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2019/000576 WO2020059977A1 (fr) 2018-09-21 2019-01-15 Réseau différentiel continûment orientable de microphones du second ordre et procédé pour le configurer

Country Status (1)

Country Link
WO (1) WO2020059977A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112073873A (zh) * 2020-08-17 2020-12-11 南京航空航天大学 一种无冗余阵元的一阶可调差分阵列的优化设计方法
WO2022170541A1 (fr) * 2021-02-10 2022-08-18 Northwestern Polytechnical University Réseau de microphones différentiels de premier ordre ayant un formeur de faisceaux orientable

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030031328A1 (en) * 2001-07-18 2003-02-13 Elko Gary W. Second-order adaptive differential microphone array
US20030063758A1 (en) * 2000-02-02 2003-04-03 Poletti Mark Alistair Microphone arrays for high resolution sound field recording
US20030072460A1 (en) * 2001-07-17 2003-04-17 Clarity Llc Directional sound acquisition
JP2005062096A (ja) * 2003-08-19 2005-03-10 Nippon Telegr & Teleph Corp <Ntt> 話者位置検出方法、装置、プログラム、および記録媒体
US20070127753A1 (en) * 2003-04-09 2007-06-07 Feng Albert S Systems and methods for interference suppression with directional sensing patterns

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030063758A1 (en) * 2000-02-02 2003-04-03 Poletti Mark Alistair Microphone arrays for high resolution sound field recording
US20030072460A1 (en) * 2001-07-17 2003-04-17 Clarity Llc Directional sound acquisition
US20030031328A1 (en) * 2001-07-18 2003-02-13 Elko Gary W. Second-order adaptive differential microphone array
US20070127753A1 (en) * 2003-04-09 2007-06-07 Feng Albert S Systems and methods for interference suppression with directional sensing patterns
JP2005062096A (ja) * 2003-08-19 2005-03-10 Nippon Telegr & Teleph Corp <Ntt> 話者位置検出方法、装置、プログラム、および記録媒体

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112073873A (zh) * 2020-08-17 2020-12-11 南京航空航天大学 一种无冗余阵元的一阶可调差分阵列的优化设计方法
WO2022170541A1 (fr) * 2021-02-10 2022-08-18 Northwestern Polytechnical University Réseau de microphones différentiels de premier ordre ayant un formeur de faisceaux orientable

Similar Documents

Publication Publication Date Title
WO2020171597A1 (fr) Dispositif électronique comprenant un dispositif d&#39;antenne
WO2019107854A1 (fr) Dispositif d&#39;affichage pliable
EP4042577A1 (fr) Dispositif électronique et procédé de commutation d&#39;antennes associé
WO2019146893A1 (fr) Structure d&#39;antenne et dispositif électronique comprenant une structure d&#39;antenne
WO2021107506A1 (fr) Dispositif électronique permettant de fournir un service de réalité augmentée et son procédé de fonctionnement
WO2015046753A1 (fr) Procédé d&#39;adaptation d&#39;impédance et système d&#39;adaptation d&#39;impédance
WO2019117652A1 (fr) Appareil à prisme, et appareil photographique comprenant celui-ci
WO2020231083A1 (fr) Dispositif électronique comprenant une structure de rayonnement de chaleur
WO2021049827A1 (fr) Dispositif électronique pour déterminer l&#39;emplacement d&#39;un dispositif électronique externe et procédé associé
WO2019225978A1 (fr) Caméra et terminal la comprenant
WO2019198978A1 (fr) Dispositif électronique équipé d&#39;un affichage souple et procédé de charge sans fil utilisant celui-ci
WO2015183050A1 (fr) Système de poursuite optique, et procédé de calcul de posture et d&#39;emplacement de partie marqueur dans un système de poursuite optique
WO2020059977A1 (fr) Réseau différentiel continûment orientable de microphones du second ordre et procédé pour le configurer
WO2016111583A1 (fr) Microphone
WO2019147048A1 (fr) Procédé de vérification de caractéristiques d&#39;un dispositif électronique et d&#39;un dispositif de communication inclus dans le dispositif électronique
WO2020180089A1 (fr) Procédé de communication de données audio et dispositif électronique le prenant en charge
WO2018174462A1 (fr) Ensemble de lentilles et dispositif optique le comprenant
WO2021125451A1 (fr) Lentille en gel électrosensible ayant des fonctions automatiques d&#39;adaptation multifocale et de stabilisation d&#39;image
WO2022131818A1 (fr) Dispositif électronique comprenant une structure pour éliminer une contrainte électrique, et carte de circuit imprimé
WO2021246823A1 (fr) Dispositif électronique comprenant une antenne
WO2022045690A1 (fr) Système optique et module de caméra le comprenant
WO2016140433A1 (fr) Objectif à focale variable et imageur
WO2019190159A1 (fr) Appareil à prismes, et caméra comprenant cet appareil
WO2024029716A1 (fr) Dispositif électronique et procédé d&#39;affichage d&#39;écran par l&#39;intermédiaire d&#39;un écran souple
WO2024005332A1 (fr) Dispositif électronique pliable comprenant une unité d&#39;entraînement permettant un changement d&#39;état

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19861942

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19861942

Country of ref document: EP

Kind code of ref document: A1