Head position self-calibration and self-positioning system and method for real-person HRTF measurement

Abstract

The present invention discloses a head position self-calibration and self-positioning system for real person HRTF measurement, the system comprising: a real person head center calibration module, a module for calibrating the position of the head center inside the human head; a sound source spatial distribution sphere center calibration module, a module for calibrating the position of the virtual sphere center of the sound source spatial distribution in space; a self-calibration and self-positioning module, a module for the subject to calibrate and position the head center on the virtual sphere center. Also disclosed is a head position self-calibration and self-positioning method for real person HRTF measurement. By using the scheme of the present invention, the head position self-calibration and self-positioning of real person HRTF measurement can be conveniently and efficiently realized.

Description

Technical Field

[0001] The present invention relates to the technical field of virtual space measurement, and in particular to a head position self-calibration and self-positioning system and method for real-person HRTF measurement. Background Art

[0002] Head-Related Transfer Functions (HRTF) describes the acoustic transmission relationship from the sound source to the two ears in a free sound field. It is related to parameters such as the sound source position and frequency, and includes factors such as the interaural level difference (ILD), time difference (ITD), and phase difference (IPD) of the sound wave reaching the two ears. It is an important clue for the human brain's auditory positioning. HRTF describes the propagation process of spatial sounds from all directions to the two ears as two left and right propagation channels to construct binaural virtual sound and reproduce spatial three-dimensional sound. It is an important basis for the study of spatial virtual hearing.

[0003] HRTF data measurement is obtained by measuring the change in sound pressure level from a point sound source on a spherical surface at a certain distance from the center of the human head to both ears. Due to the limitations of human perception and physiological characteristics, it is difficult for the subject to accurately calibrate the center of his head and always locate it on the center of the virtual space sphere where the sound source is distributed. The calibration and positioning of the center of the human head on the center of the space sphere has a direct impact on the accuracy of HRTF measurement data. Generally, it is necessary to find the degree of deviation of the subject's head in real time during the measurement process, and constantly guide the subject to adjust, correct and require the subject to keep the head position and posture within the tolerance range of the measurement. In some real-person HRTF measurements with high accuracy requirements, the distance between the sound source and the human head is used to calibrate and locate the head position, and even the photoelectric theodolite is used to locate the head position. The above-mentioned head calibration and positioning methods not only affect the accuracy of HRTF data, but also require the subject to be constantly guided to adjust and correct the head position, which affects the efficiency of HRTF measurement. At the same time, the guidance, warning, and prompt sounds will generate noise that affects the accuracy of HRTF data, and positioning equipment such as photoelectric theodolites will also interfere with HRTF acoustic measurement equipment. Summary of the invention

[0004] The present invention provides a head position self-calibration and self-positioning system and method for real-person HRTF measurement, so that the subject can calibrate and position the head position in real time without additional guidance, without interference and noise, and with low cost, high precision and high efficiency.

[0005] To this end, the present invention provides the following technical solutions:

[0006] A head position self-calibration and self-positioning system for real-person HRTF measurement, the system comprising:

[0007] The real head center calibration module is used to calibrate the position of the subject's head center inside the human head, including the coronal plane mark, sagittal plane mark and horizontal plane auxiliary mark of the human head;

[0008] The virtual sphere center calibration module is used to calibrate the position of the sphere center of the sound source spatial distribution in the measurement space, including the coronal plane mark, sagittal plane mark and horizontal plane auxiliary mark of the sound source spatial distribution sphere;

[0009] The self-calibration and self-positioning module is used to perform head self-calibration and head self-positioning on the subject according to the marks calibrated by the real head center calibration module and the marks calibrated by the virtual sphere center calibration module. The head self-calibration refers to calibrating the standard head position by accurately aligning the head center with the sphere center, and the head position self-positioning refers to head position positioning within the allowable range of measurement error of the standard head position.

[0010] Optionally, the self-calibration and self-positioning module includes: an imaging system, a calibration prompter, and a positioning deviation prompter;

[0011] The imaging system is used to achieve inversion of out-of-field markers;

[0012] The calibration reminder is used to remind the subject's current position as the head calibration standard position during the positioning process;

[0013] The positioning deviation indicator is used to indicate that the head position of the subject exceeds the measurement allowable error during the positioning process.

[0014] Optionally, the imaging system comprises: a first plane mirror, a second plane mirror, and a prism system;

[0015] The first plane mirror is used for imaging the facial mark of the subject, and the mirror mark obtained by the auxiliary mark of the horizontal plane of the head and the mark of the sagittal plane of the head through the first plane mirror, together with the mirror mark formed by the coronal plane mark of the head through the prism system and the second plane mirror, forms the head conversion mark;

[0016] The auxiliary marks formed by the horizontal plane auxiliary marks of the sound source space distribution sphere and the sagittal plane marks of the sound source space distribution sphere through the prism system and the second plane mirror together form the sound source space distribution sphere conversion marks.

[0017] Optionally, a vertical center line and a horizontal center line are etched on the mirror surfaces of the first plane mirror and the second plane mirror respectively; a movable straight sticker mark is affixed to the first plane mirror, and the sticker mark is parallel to the horizontal center line on the mirror surface of the first plane mirror.

[0018] Optionally, there are three straight line marks on the sticker mark, which respectively correspond to the auxiliary mark of the horizontal plane of the center of the sphere, and the upper limit mark and lower limit mark of the error allowed in the horizontal plane of HRTF measurement.

[0019] Optionally, the first plane mirror and the second plane mirror are installed on the inner wall of the anechoic chamber directly in front of the subject, and the vertical midline on the mirror surface of the first plane mirror and the vertical midline on the mirror surface of the second plane mirror both coincide with the coronal plane mark of the sound source spatial distribution sphere on the wall of the anechoic chamber; the horizontal midline on the mirror surface of the first plane mirror coincides with the horizontal plane mark of the sound source spatial distribution sphere on the wall of the anechoic chamber; the horizontal midline on the mirror surface of the second plane mirror coincides with the sagittal plane auxiliary mark of the sound source spatial distribution sphere on the wall of the anechoic chamber.

[0020] Optionally, the prism system includes: a group of optical modules installed just above the head of the subject and at the vertex of the center of the sound source spatial distribution sphere.

[0021] Optionally, the calibration prompter includes at least two color photosensitive light emitting devices, which are respectively installed at the intersection of the sagittal plane marking line of the sound source space distribution sphere and the horizontal plane auxiliary marking line of the sound source space distribution sphere, and the sagittal plane auxiliary marking line of the sound source space distribution sphere, and correspond to the center of the first plane mirror and the second plane mirror;

[0022] When the head center mirror image mark in the first plane mirror and the second plane mirror completely overlaps with the spherical center mark, the colored photosensitive light-emitting device is triggered to emit light, indicating that the head center is accurately registered with the spherical center position, prompting the subject to be currently in the standard reference position and can start measurement and maintain this position as much as possible during the measurement process.

[0023] Optionally, the positioning deviation indicator includes: six color photosensitive light emitting devices, which are respectively installed on the upper limit auxiliary marking lines of the horizontal plane auxiliary marking of the sound source space distribution sphere, the coronal plane marking, and the sagittal plane auxiliary marking;

[0024] When the head center mirror image mark in the first plane mirror deviates from the upper and lower limit threshold mark lines of the spherical center mark, the corresponding color photosensitive light bar is triggered to dim, prompting the subject's head position to exceed the allowable measurement error and the head position needs to be fine-tuned in the opposite direction before continuing the measurement.

[0025] A head position self-calibration and self-positioning method for real-person HRTF measurement, the method comprising:

[0026] Use the horizontal, sagittal and coronal planes of the subject's head to uniquely mark the position of the head center in the human head;

[0027] Use the horizontal, sagittal and coronal planes of the subject's head to uniquely mark the position of the head center in the human head;

[0028] According to the mark calibrated by the real head center calibration module and the mark calibrated by the virtual sphere center calibration module, the standard head position is calibrated by accurately aligning the head center with the sphere center;

[0029] Head positioning within the allowable range of measurement error of the standard head position.

[0030] Optionally, the use of the horizontal plane, sagittal plane and coronal plane of the subject's head to uniquely mark the position of the head center in the human head includes:

[0031] The horizontal, sagittal and coronal planes of the sound source spatial distribution sphere are marked on the inner wall of the anechoic chamber for real-person HRTF measurement using visual geometric markers.

[0032] Optionally, the visual geometric mark is a high-brightness, high-contrast line, or a reflective pattern, or a luminous bright stripe.

[0033] The head position self-calibration and self-positioning system and method for real-person HRTF measurement provided by the embodiment of the present invention uses multiple planes to calibrate the position of the center of the human head and the center of the sphere of the spatial distribution of the sound source, and converts the out-of-field mark that the subject cannot observe into the field of view mark through the imaging system. The subject actively visually adjusts his head position to coincide and align the head center mark and the sphere center mark, thereby realizing the head position self-calibration and self-positioning of real-person HRTF measurement. Using the scheme of the present invention, the subject can calibrate and position the head position in real time without additional guidance, without interference and noise, and with low cost, high precision and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of a head position self-calibration and self-positioning system for real-person HRTF measurement according to an embodiment of the present invention;

[0035] Figure 2 It is a principle diagram of the calibration of the head center and the sphere center in an embodiment of the present invention;

[0036] Figure 3 It is a head center calibration plane marking diagram in an embodiment of the present invention;

[0037] Figure 4 is a horizontal plane auxiliary marking diagram for head center calibration in an embodiment of the present invention;

[0038] Figure 5 is a plane marking diagram for calibrating the center of the sound source spatial distribution sphere in an embodiment of the present invention;

[0039] Figure 6 It is an auxiliary marking diagram for calibrating the horizontal plane of the sphere center of the sound source spatial distribution in an embodiment of the present invention;

[0040] Figure 7It is a sagittal plane auxiliary marking diagram for calibrating the center of the sound source spatial distribution in an embodiment of the present invention;

[0041] Figure 8 is a structural schematic diagram of a head position self-calibration and self-positioning module in an embodiment of the present invention;

[0042] Fig. 9 is a schematic structural diagram of an imaging plane mirror in an embodiment of the present invention;

[0043] Fig.10 Schematic diagram of the installation position of the imaging plane mirror in an embodiment of the present invention;

[0044] Fig.11 It is a diagram of the layout of the prism system and the imaging optical path of the auxiliary marker for determining the sagittal plane of the spherical center in an embodiment of the present invention;

[0045] Fig.12 : is a light path diagram of a sagittal plane marking imaging of a human head of a prism system in an embodiment of the present invention;

[0046] Fig.13 is a light path diagram of human facial marker imaging in plane mirror imaging in an embodiment of the present invention;

[0047] Fig.14 is a layout diagram of a calibration prompter in an embodiment of the present invention;

[0048] Fig.15 is a layout diagram of a positioning deviation indicator in an embodiment of the present invention;

[0049] Fig.16 It is a flow chart of head position self-calibration and self-positioning for real person HRTF measurement according to an embodiment of the present invention;

[0050] Fig.17 The present invention is a flowchart of head self-calibration and self-positioning for real person HRTF measurement using the method of the present invention.

[0051] Main markings in the attached drawings:

[0052] 201, horizontal plane of the sphere; 202, coronal plane; 203, sagittal plane; 204, center of the sphere;

[0053] 301, horizontal plane mark of human head; 302, coronal plane mark of human head; 303, sagittal plane mark of human head; 304, center of head;

[0054] 401. Auxiliary marking of the head center horizontal plane;

[0055] 501, horizontal plane mark of the sphere center; 502, coronal plane mark of the sphere center; 503, sagittal plane mark of the sphere center;

[0056] 601, auxiliary mark of the horizontal plane of the ball center; 701, auxiliary mark of the sagittal plane of the ball center;

[0057] 806. Head-center conversion mark; 807. Ball-center conversion mark. DETAILED DESCRIPTION

[0058] In order to enable those skilled in the art to better understand the solutions of the present invention, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings and implementation modes.

[0059] In response to the problem of head calibration and positioning in real-person HRTF measurement, an embodiment of the present invention provides a head self-calibration and self-positioning system and method for real-person HRTF measurement, which uses plane markers to calibrate the positions of the center of the human head and the center of the sphere of the spatial distribution of the sound source. The out-of-field marks that the subject cannot observe are converted into field-of-view marks through an imaging system. The subject can actively visually search for marks and adjust his or her own head posture to register and align the head center mark and the sphere center mark, thereby realizing head self-calibration and self-positioning for real-person HRTF measurement.

[0060] Several concepts involved in the scheme of the present invention are first described below.

[0061] The head center and sphere center calibration refers to calibrating the head center and sphere center using multiple plane markers set on the head and in space. The plane markers can be presented in the subject's field of view directly or through inversion, and the inversion refers to converting the out-of-field markers into visual markers.

[0062] Head position self-calibration means that the subject aligns the corresponding plane marks of the head center and the virtual sphere center to determine the standard head position when the two coincide.

[0063] Head self-positioning means that the subject keeps the standard head position within the allowable range of measurement error and aligns the plane mark of the head with the plane mark of the sound source distribution space sphere.

[0064] In the embodiment of the present invention, the head center calibration is based on the intersection of three mutually perpendicular planes at a unique point in space, and the horizontal plane, sagittal plane and coronal plane of the subject's head are used to uniquely mark the position of the head center in the human head.

[0065] Specifically, the horizontal plane of the binocular line is selected as the horizontal plane of the human head, the vertical plane where the binocular line is located is selected as the sagittal plane of the human head, and the vertical plane where the nasal midline is located is selected as the coronal plane of the human head.

[0066] More specifically, the horizontal, sagittal and coronal planes of the human head are marked with high-brightness, high-contrast materials, or luminous materials. The markings do not affect the outline of the human head, and their shape, dimensions and size are negligible compared to the human head.

[0067] Similarly, based on the intersection of three mutually perpendicular planes at a unique point in space, the horizontal, sagittal and coronal planes of a virtual spherical shape formed by the spatial distribution of the point sound source measured by HRTF uniquely mark the spatial position of the center of the virtual sphere in the anechoic chamber measured by HRTF.

[0068] Specifically, the plane where the maximum horizontal cross-section circle of the sound source space distribution sphere is located is selected as the horizontal plane of the sound source space distribution sphere, and the planes where two orthogonal maximum cross-section circles perpendicular to the maximum horizontal cross-section circle are located are selected as the sagittal plane and the coronal plane of the sound source space distribution sphere.

[0069] More specifically, the horizontal, sagittal and coronal planes of the sound source spatial distribution sphere are marked on the inner wall of the anechoic chamber for real-person HRTF measurement with visual geometric markers. The geometric markers are high-brightness, high-contrast lines, or reflective patterns, luminous bright strips and other visual markers. The strip width does not exceed the spatial resolution requirement of the HRTF measurement, and its laying and installation should not affect the overall performance of the anechoic chamber for measurement.

[0070] The above calibration information is used to realize self-calibration and self-positioning of the head of the subject.

[0071] like Figure 1 , which is a schematic diagram of the structure of a head position self-calibration and self-positioning system for real-person HRTF measurement according to an embodiment of the present invention.

[0072] In this embodiment, the system includes a real head center calibration module 101, a virtual sphere center calibration module 102, and a self-calibration and self-positioning module 103. Among them:

[0073] A real person head center calibration module 101 is used to calibrate the head center coronal plane mark, the head center sagittal plane mark, and the head center horizontal plane auxiliary mark;

[0074] A virtual sphere center calibration module 102 is used to calibrate a sphere center coronal plane module mark, a sphere center sagittal plane mark, and a sphere center horizontal plane auxiliary mark;

[0075] The self-calibration and self-positioning module 103 is used to perform head self-calibration and head self-positioning on the subject according to the marks calibrated by the real head center calibration module and the marks calibrated by the virtual sphere center calibration module. The head self-calibration refers to calibrating the standard head position by accurately aligning the head center with the sphere center, and the head position self-positioning refers to head position positioning within the allowable range of measurement error of the standard head position.

[0076] Head position calibration is used to determine the initial standard position of the human head at the beginning of real-person HRTF measurement. The standard head position required for reference in the real-person HRTF measurement process is calibrated by accurately aligning the center of the head with the center of the sphere. Head position positioning is the alignment of the subject's head with the standard position during the measurement process, that is, the head position positioning of the head center within the allowable measurement error range of the initial standard head position.

[0077] It should be noted that self-calibration and self-positioning means that the subject actively calibrates and positions his or her own head position in HRTF measurement, without the need for other additional guidance to passively adjust and correct the head position. Specifically, it can be achieved by the subject visually adjusting the plane marks corresponding to the head center and the sphere center, and keeping the marks aligned.

[0078] Furthermore, in another embodiment of the head self-calibration and self-positioning system for real-person HRTF measurement of the present invention, the system may further include: a data storage module 104, which is used to record and store head calibration and positioning data of real-person HRTF measurement, and these data are an important basis for correcting head positioning errors in real-person HRTF measurement.

[0079] like Figure 2 , which is a schematic diagram of the calibration of the head center and the sphere center in an embodiment of the present invention. The horizontal plane 201, the coronal plane 202 and the sagittal plane 203 of the sphere intersect at a unique point in space, namely the sphere center 204. Based on this, marking the horizontal plane, sagittal plane and coronal plane of the subject's head and the sound source distribution space sphere with fixed marks in their space is equivalent to determining the position of the center in their space.

[0080] like Figure 3 As shown, it is a planar marking diagram of the head center calibration in an embodiment of the present invention. The binocular line is used as a horizontal plane mark 301 of the head, the nasal midline is used as a coronal plane mark 302 of the head, and the binocular line is used as a sagittal plane mark 303 of the head. The intersection of the three planes uniquely calibrates the position of the head center 304 inside the head.

[0081] like Figure 4 As shown, it is a horizontal plane auxiliary marking diagram of the head center calibration in an embodiment of the present invention. In order to eliminate the influence of human eye blinking on the marking stability, and also to avoid the influence of the binocular line as the head horizontal plane mark 301 on human eye observation, the frame bone 402 above the two eyes is selected as the auxiliary mark 401 to replace the binocular line mark head horizontal plane mark 301, and the auxiliary mark 401 is the head center horizontal plane auxiliary mark. The marking line is pasted, painted or projected on the corresponding position of the human head with high-brightness, high-reflective material, safety laser line, so as to facilitate clear imaging in the mirror system. There is an individualized parameter △z between the two marking lines, which varies from person to person. △z is the vertical distance 403 between the line connecting the centers of the frame bones above the left and right eyes and the line connecting the pupils of both eyes. △z is also the height of the head center deviation 404 generated by the head center 304 and the head center horizontal plane auxiliary mark 401.

[0082] like Figure 5As shown in FIG. 1 , it is a plane marking diagram for calibrating the center of the sound source space distribution sphere in an embodiment of the present invention. The largest horizontal cross-section circle of the sound source space distribution sphere is selected as the horizontal plane 201, and the two largest orthogonal vertical cross-section circles perpendicular to the horizontal plane are selected as its coronal plane 202 and sagittal plane 203. The intersection lines of these planes with the inner wall of the anechoic chamber measured by HRTF are marked, i.e. Figure 5 The horizontal plane mark 501, the coronal plane mark 502, and the sagittal plane mark 503 of the sphere center are used to uniquely mark the spatial position of the sphere center of the sound source spatial distribution in the anechoic chamber. The marking line is pasted, painted, or projected on the corresponding position of the inner wall of the anechoic chamber with a high-brightness, high-contrast material or a safety laser line to facilitate clear observation by the test subject.

[0083] like Figure 6 As shown, it is an auxiliary marking diagram of the horizontal plane for calibrating the center of the sound source spatial distribution in an embodiment of the present invention.

[0084] Since the horizontal plane mark of the head center calibration uses the connecting line of the center of the left and right eye frame bones as the head center horizontal plane auxiliary mark 401, the horizontal plane mark 501 of the sound source spatial distribution spherical center calibration is determined according to the individualized parameter △z of the subject and an auxiliary mark line is set accordingly. Taking one inner wall of the anechoic chamber as an example, a movable auxiliary mark line is made above the original mark line 501. The auxiliary mark line is the spherical center horizontal plane auxiliary mark 601, which is parallel to the spherical center calibration horizontal plane mark 501, and the distance between the two is △z. On both sides of the spherical center horizontal plane auxiliary mark 601 are the upper limit mark 602 and the lower limit mark 603 of the error allowed in the horizontal plane for HRTF measurement. Similarly, on both sides of the spherical center coronal plane mark 502 are the upper limit mark 604 and the lower limit mark 605 of the error allowed in the coronal plane for HRTF measurement.

[0085] like Figure 7 , which is an auxiliary marking diagram of the sagittal plane for calibrating the center of the sound source spatial distribution in an embodiment of the present invention.

[0086] Since the sagittal plane mark 503 for calibrating the center of the sound source spatial distribution sphere is outside the subject's field of vision, a part of it needs to be transformed into a visual target that can be observed by the subject through the imaging system, that is, the sagittal plane auxiliary mark 701 for calibrating the center of the sound source spatial distribution sphere, which can be set on the inner wall or floor of the anechoic chamber within the subject's field of vision. In this embodiment, it is set on the inner wall of the anechoic chamber directly in front of the subject and is located below the horizontal plane mark 501. On both sides of the sagittal plane auxiliary mark 701 are the upper limit mark 702 and the lower limit mark 703 of the error allowed in the sagittal plane for HRTF measurement.

[0087] Since the subject cannot observe the out-of-field marks on his head and face and the sagittal plane of the sphere center above, below, left and right, it is necessary to partially invert them into field marks that the subject can observe. The head position self-calibration and self-positioning module in the embodiment of the present invention uses, including but not limited to, an imaging system to achieve the inversion of out-of-field marks, so that the subject can actively and dynamically adjust and correct the head position in real time.

[0088] like Figure 8 , which is a schematic diagram of the structure of the head position self-calibration and self-positioning module in an embodiment of the present invention.

[0089] In this embodiment, the head position self-calibration and self-positioning module includes: an imaging system, a calibration prompter 804, and a positioning deviation prompter 805. Among them:

[0090] The imaging system is used to realize the inversion of the out-of-field mark, or to convert the out-of-field mark into a mark within the field of view of the subject;

[0091] The calibration prompter 804 is used to prompt the subject's head center to accurately register at the sphere center during the positioning process;

[0092] The positioning deviation indicator 805 is used to indicate that the head position of the subject exceeds the measurement allowable error during the positioning process.

[0093] It should be noted that any system that can convert marks that cannot be observed outside the subject's field of view into marks in his field of view can be used as the imaging system. The imaging system can be an optical imaging system such as a plane mirror, a curved mirror, a spherical mirror, or other imaging systems composed of a miniature camera, a camera, and a small display. Any imaging system that can achieve the above purpose belongs to the scope of the present invention. Figure 8 In the illustrated embodiment, the imaging system may include, but is not limited to, any one or more of the following: a first plane mirror 801 , a second plane mirror 802 , and a prism system 803 .

[0094] The calibration indicator 804 is a signal indicator device indicating that the head position calibration is completed. When the plane marks corresponding to the calibrated head center and the sphere center completely coincide with each other, a standard position signal of the head center at the sphere center is given to indicate that the current position of the subject is the standard position for head position calibration.

[0095] The above-mentioned positioning deviation indicator 805 is a signal prompt device to prompt the head positioning deviation. When the head posture of the subject changes so that the deviation of the head center from the calibration position exceeds the allowable error range of the measurement, that is, the calibration mark line of the head center plane exceeds the upper and lower limit marks of the plane calibration mark line corresponding to the sphere center, the subject is prompted to adjust the head position to correct the deviation.

[0096] In a specific application, the positioning deviation indicator 805 can be set on both sides of the calibration indicator 804, and the distance between the calibration indicator 804 and the calibration indicator 804 can be half of the measurement positioning error range.

[0097] Continue to refer to Figure 8 The mirror image mark formed by the head center horizontal plane auxiliary mark 401 and the head coronal plane mark 302 after the first plane mirror 801, together with the mirror image mark formed by the head sagittal plane mark 303 after the prism system 803 and the second plane mirror 802, form a head center conversion mark 806.

[0098] The auxiliary mark 701 of the horizontal plane of the sphere center, the auxiliary mark 601 of the coronal plane of the sphere center 502 and the auxiliary mark 701 determined by the prism system 803 together form the sphere center transformation mark 807.

[0099] It should be noted that the head-center conversion mark 806 and the spherical-center conversion mark 807 are both visual marks observable within the subject's field of view. The subject visually adjusts the head posture by himself or herself so that the head-center conversion mark 806 coincides with and remains aligned with the corresponding spherical-center conversion mark 807 fixed inside the anechoic chamber, thereby achieving self-calibration and self-positioning of the head position.

[0100] The head position self-calibration and self-positioning of HRTF measurement can enable the subject to actively and dynamically adjust and correct the head position in real time, ensuring the positioning accuracy and measurement efficiency of the measurement data.

[0101] like Fig. 9 The figure is a schematic diagram of the structure of the imaging plane mirror in an embodiment of the present invention.

[0102] Figure 8 A vertical center line 901, 904 and a horizontal center line 907, 908 are etched on the mirror surface of the first plane mirror 801 and the second plane mirror 802, respectively. The upper and lower limit marks 902, 903 and 905, 906 of the coronal plane error measured by HRTF are marked on both sides of the vertical center lines 901, 904, respectively. A movable straight bar marking sticker 909 is attached to the first plane mirror 801. There are three straight line marks 911, 912, 913 on the marking sticker 909, which correspond to the three lines 601, 602, 603 of the auxiliary marks on the horizontal plane of the sphere center, respectively. The sticker mark 909 is parallel to the horizontal center line 907 on the mirror surface of the first plane mirror 801. The distance between the straight line mark 911 and the horizontal center line 907 is the same as the vertical distance 403 between the connecting line of the center of the upper periapical bone of the left and right eyes and the connecting line of the pupils of both eyes, representing the individualized human body parameter △z. The upper and lower limit marks 914 and 915 of the sagittal plane error of HRTF measurement are respectively marked on both sides of the horizontal midline 908 on the mirror surface of the second plane mirror 802.

[0103] like Fig.10 The figure is a schematic diagram of the installation position of the imaging plane mirror in an embodiment of the present invention.

[0104] Figure 8 The first plane mirror 801 and the second plane mirror 802 in the embodiment can be, but are not limited to, installed on the inner wall of the anechoic chamber in front of the subject, and the vertical center lines 901 and 904 on the mirror surface coincide with the spherical center coronal plane mark 502 on the anechoic chamber wall. The horizontal center line 907 coincides with the spherical center horizontal plane mark 501 on the anechoic chamber wall, and the horizontal center line 908 coincides with the spherical center sagittal plane auxiliary mark 701 on the anechoic chamber wall.

[0105] like Fig.11 The figure shows the layout of the prism system and the optical path diagram for determining the sagittal plane auxiliary marking imaging of the spherical center in the implementation of the present invention.

[0106] Figure 8 The prism system 803 in the figure is an optical system composed of a group of optical modules, which is installed just above the head of the subject and at the vertex of the center of the sound source spatial distribution sphere. The part of the marking line of the spherical center sagittal plane mark 503 on the floor can be imaged on the inner wall of the anechoic chamber in front of the subject through the prism system 803. The angle of the optical module of the prism system 803 is adjusted so that it is imaged at the most suitable position for observation in front of the subject, and then the position is determined to be the spherical center sagittal plane auxiliary mark 701.

[0107] like Fig.12 , which is a light path diagram of the sagittal plane marking imaging of the top of a human head of the prism system in an embodiment of the present invention.

[0108] exist Fig.11 After the layout of the prism system 803 and the setting of the spherical center sagittal plane auxiliary mark 701, it can be known from the principle of geometric optics that as long as the mark on the top of the head is in the incident light path of the prism system 803, the head sagittal plane mark 503 will also be imaged on the spherical center sagittal plane auxiliary mark 701. The subject can observe the image of the head sagittal plane mark 503 on the top of his head from the second plane mirror 802. In this way, the subject can adjust his head by himself to make it overlap and align with the spherical center sagittal plane auxiliary mark 701 etched on the second plane mirror 802 by observing the image of the head sagittal plane mark 503 in the second plane mirror 802.

[0109] like Fig.13 , which is a light path diagram of human facial marker imaging in plane mirror imaging in an embodiment of the present invention.

[0110] Among them, the first plane mirror 801 is used for imaging the facial marks of the subject. According to the imaging principle of the plane mirror, the subject can observe the images of the auxiliary marks 401 on the horizontal plane of the head center and the coronal plane marks 302 of the human head on his or her face from the first plane mirror 801, and adjust the head by observing the mirror marks to make them coincide and align with the marks etched on the first plane mirror 801.

[0111] like Fig.14 , which is a schematic diagram of the layout of the calibration prompter in an embodiment of the present invention.

[0112] The calibration reminder is a signal reminder device that indicates that the head position calibration is completed. When the three-plane marking lines of the calibration head center and the sphere center completely coincide, a standard registration position signal of the head center at the sphere center is given to remind the subject that the current position is the standard position for head position calibration.

[0113] The calibration reminder in this embodiment can be, but is not limited to, a color photosensitive light emitting device, for example, it can be installed at the intersection positions 1401 and 1402 of the spherical center coronal plane mark 502, the spherical center horizontal plane auxiliary mark 601, and the spherical center sagittal plane auxiliary mark 701, respectively, corresponding to the center of the first plane mirror 801 and the second plane mirror 802. When the head center mirror image mark in the two plane mirrors completely coincides with the spherical center mark, the two color photosensitive light emitting devices are triggered to emit light, indicating that the head center is calibrated at the spherical center position, prompting the subject to be currently in the standard reference position, and can start measurement and try to maintain this position during the measurement process.

[0114] like Fig.15 FIG. 1 is a schematic diagram of the layout of a positioning deviation indicator in an embodiment of the present invention.

[0115] The positioning deviation indicator is a signal prompt device that prompts the head positioning deviation. When the head posture of the subject changes and the deviation of the head center from the calibration position exceeds the allowable error range of the measurement, that is, the calibration mark line of the head center plane exceeds the upper and lower limit marks of the calibration mark line of the plane corresponding to the sphere center, the subject is prompted to adjust the head position to correct the deviation.

[0116] The positioning deviation indicator of this embodiment can be, but is not limited to, a color photosensitive light emitting device. For example, six light emitting devices 1501, 1502, 1503, 1504, 1505, and 1506 can be installed, respectively installed on the upper limit auxiliary marking lines 602, 603, 604, 605, and 702, 703 of the spherical center horizontal plane auxiliary mark 601, the spherical center coronal plane mark 502, and the spherical center sagittal plane auxiliary mark 701. When the head center mirror image marks in the two plane mirrors deviate from the upper and lower limit threshold marking lines of the spherical center marks, the corresponding color photosensitive light strips are triggered to dim, indicating that the head position of the subject exceeds the measurement allowable error and the head position needs to be fine-tuned in the opposite direction before continuing the measurement.

[0117] like Fig.16 FIG. 1 is a flow chart of a head position self-calibration and self-positioning method for real-person HRTF measurement according to an embodiment of the present invention, comprising the following steps:

[0118] Step 161, using the horizontal plane, sagittal plane and coronal plane of the subject's head to uniquely mark the position of the head center in the human head.

[0119] Step 162, using the horizontal plane, sagittal plane and coronal plane of the subject's head to uniquely mark the position of the head center in the human head.

[0120] Specifically, the horizontal plane, sagittal plane and coronal plane of the sound source spatial distribution sphere can be marked on the inner wall of the anechoic chamber for real-person HRTF measurement with visual geometric markers, wherein the visual geometric markers are high-brightness, high-contrast lines, or reflective stripes, or luminous bright stripes, etc., which are not limited in the embodiments of the present invention.

[0121] Step 163: calibrate the standard head position by accurately aligning the head center with the sphere center according to the mark calibrated by the real head center calibration module and the mark calibrated by the virtual sphere center calibration module.

[0122] Specifically, this can be achieved by the subject visually adjusting the marks on the head so that the center of the head and the center of the ball correspond to the plane marks and keeping the marks aligned.

[0123] Since the subject cannot observe the out-of-field marks on his head and face and the sagittal plane of the sphere center above, below, left and right, it is necessary to partially invert them into field marks observable by the subject. To this end, the embodiment of the present invention can use, including but not limited to, an imaging system to achieve inversion of out-of-field marks, so that the subject can actively and dynamically adjust and correct the head position in real time, ensuring the positioning accuracy and measurement efficiency of the measurement data.

[0124] The imaging system can convert marks that cannot be observed outside the field of vision of the subject into visible targets within the field of vision. The imaging system can be an optical imaging system such as a plane mirror, a curved mirror, a spherical mirror, or an image imaging system composed of a micro camera, a camera, and a small display. Any imaging system that can achieve the above purpose belongs to the scope of the present invention.

[0125] Step 164: Position the head within the allowable range of measurement error of the standard head position.

[0126] The head position self-calibration and self-positioning system and method for real-person HRTF measurement provided in the embodiments of the present invention use plane markers to calibrate the positions of the center of the human head and the center of the sphere of the spatial distribution of the sound source, and convert out-of-field marks that the subject cannot observe into field-of-view marks through an imaging system. The subject can actively visually search for marks and adjust his or her own head posture to register and align the head center mark and the sphere center mark, thereby realizing head position self-calibration and self-positioning for real-person HRTF measurement.

[0127] Reference Fig.17 , is a flow chart of head position self-calibration and self-positioning for real person HRTF measurement using the method of the present invention.

[0128] First, the subject is ready to visually search for marks, observe the marks on the ball center calibration surface and the head center calibration surface. The subject actively adjusts the posture according to the marks, aligning the corresponding marks of the head center and the ball center until the calibration indicator is fully lit.

[0129] The calibration indicator is fully lit, indicating that the corresponding plane marks of the calibration head center and the sphere center are completely overlapped, and the head position self-calibration is completed. At this time, the corresponding calibration data can be saved, that is, the initial standard position of the head position is recorded.

[0130] Then, observe the positioning deviation indicator. If the positioning deviation indicator is fully lit, it means that the change in the subject's head posture causes the deviation of the head center from the standard positioning to exceed the allowable error range of the measurement. The subject needs to adjust the head position to correct the deviation; otherwise, the measurement can be started.

[0131] The head self-calibration and self-positioning system and method for real-person HRTF measurement provided in the embodiments of the present invention can be used for head calibration and positioning in high-precision, large-sample real-person HRTF actual measurement, and can effectively improve the accuracy and efficiency of actual measurement.

[0132] The solution of the present invention has the advantages of low cost, anti-interference, zero noise, high precision and high efficiency. It can support high-precision personalized HRTF customization and large-sample HRTF data measurement. It has great application value and social benefits for improving the performance of acoustic products based on HRTF data and promoting the application of HRTF new technology products.

[0133] The embodiments listed in the present invention are only one example of the system of the present invention and are not actually limited thereto. Any examples that can realize this system belong to the scope of the present invention.

[0134] The embodiments of the present invention are described in detail above. The present invention is explained in this article using specific implementation methods. The description of the above embodiments is only used to help understand the present invention to build a practical head position calibration and positioning system in actual measurement. It is only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should belong to the scope of protection of the present invention, and the content of this specification should not be understood as limiting the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A head position self-calibration and self-positioning system for real-person HRTF measurement, characterized in that: The system comprises: The real head center calibration module is used to calibrate the position of the subject's head center inside the human head, including the coronal plane mark, sagittal plane mark and horizontal plane auxiliary mark of the human head; Select the frame bone above the eyes as an auxiliary mark, which is the horizontal plane auxiliary mark of the human head; The virtual sphere center calibration module is used to calibrate the position of the center of the sound source spatial distribution sphere in the measurement space, including the coronal plane mark, sagittal plane mark and horizontal plane auxiliary mark of the sound source spatial distribution sphere; A self-calibration and self-positioning module, used to perform head self-calibration and head self-positioning on the subject according to the marks calibrated by the real head center calibration module and the marks calibrated by the virtual sphere center calibration module, wherein the head self-calibration refers to calibrating a standard head position by accurately aligning the head center with the sphere center, and the head position self-positioning refers to positioning the head position within the allowable range of measurement error of the standard head position; The self-calibration and self-positioning module includes: an imaging system, a calibration indicator, and a positioning deviation indicator; The imaging system is used to achieve inversion of out-of-field markers, including mirror inversion; The calibration reminder is used to remind the subject that the current position is the head calibration standard position during the positioning process; The positioning deviation indicator is used to indicate during the positioning process that the head position of the subject exceeds the allowable measurement error; The imaging system comprises: a first plane mirror, a second plane mirror, and a prism system; The first plane mirror is used for imaging the facial mark of the subject, and the mirror mark obtained by the horizontal plane auxiliary mark of the head and the coronal plane mark of the head through the first plane mirror, together with the mirror mark formed by the sagittal plane mark of the head through the prism system and the second plane mirror, form a head conversion mark; The horizontal plane auxiliary mark and the coronal plane mark of the sound source space distribution sphere, as well as the sagittal plane mark, pass through the prism system and the auxiliary mark formed by the second plane mirror to form the sound source space distribution sphere conversion mark.

2. The system according to claim 1, characterized in that A vertical center line and a horizontal center line are etched on the mirror surfaces of the first plane mirror and the second plane mirror respectively; A movable straight sticker mark is attached to the first plane mirror, and the sticker mark is parallel to the horizontal center line on the mirror surface of the first plane mirror.

3. The system according to claim 2, characterized in that The sticker mark has three straight line marks which correspond to the horizontal plane auxiliary marks of the sound source spatial distribution sphere, and the upper limit mark and lower limit mark of the error allowed in the horizontal plane for HRTF measurement.

4. The system according to claim 2, characterized in that The first plane mirror and the second plane mirror are installed on the inner wall of the anechoic chamber directly in front of the subject, and the vertical midline on the mirror surface of the first plane mirror and the vertical midline on the mirror surface of the second plane mirror both coincide with the coronal plane mark of the sound source space distribution sphere on the wall of the anechoic chamber; the horizontal midline on the mirror surface of the first plane mirror coincides with the horizontal plane mark of the sound source space distribution sphere on the wall of the anechoic chamber; the horizontal midline on the mirror surface of the second plane mirror coincides with the sagittal plane auxiliary mark of the sound source space distribution sphere on the wall of the anechoic chamber.

5. The system according to claim 1, characterized in that The prism system includes: a group of optical modules installed above the head of the person being measured and directly above the center of the sound source spatial distribution sphere.

6. The system according to any one of claims 1 to 5, characterized in that: The calibration prompter includes at least two color photosensitive light emitting devices, which are respectively installed at the intersection of the coronal plane marking line of the sound source space distribution sphere, the horizontal plane auxiliary marking line of the sound source space distribution sphere, and the sagittal plane auxiliary marking line of the sound source space distribution sphere, and correspond to the center of the first plane mirror and the second plane mirror; When the human head mirror image marks in the first plane mirror and the second plane mirror completely overlap with the sound source spatial distribution sphere marks, the color photosensitive light-emitting device is triggered to emit light, indicating that the center of the head is accurately registered with the center of the sphere, prompting the subject to be currently in the standard reference position and that measurement can be started and maintained in this position as much as possible during the measurement process.

7. The system according to claim 6, characterized in that The positioning deviation indicator comprises: six color photosensitive light emitting devices, which are respectively installed on the upper and lower limit auxiliary marking lines of the horizontal plane auxiliary marking, the coronal plane marking, and the sagittal plane auxiliary marking of the sound source space distribution sphere; When the head image mark in the first plane mirror deviates from the upper and lower threshold mark lines of the sound source space distribution sphere mark, the corresponding colored photosensitive light bar is triggered to dim, indicating that the head position of the subject exceeds the allowable measurement error and the head position needs to be fine-tuned in the opposite direction before continuing the measurement.

8. A head position self-calibration and self-positioning method for real person HRTF measurement using the system of claim 1, characterized in that: The method comprises: Use the horizontal, sagittal and coronal planes of the subject's head to uniquely mark the position of the head center in the human head; The horizontal, sagittal and coronal planes of the virtual sphere formed by the spatial distribution of the point sound source used for HRTF measurement, uniquely mark the spatial position of the center of the virtual sphere in the anechoic chamber for HRTF measurement; According to the mark calibrated by the real head center calibration module and the mark calibrated by the virtual sphere center calibration module, the standard head position is calibrated by accurately aligning the head center with the sphere center; Head positioning within the allowable range of measurement error of the standard head position.

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