Hearing system for unmanned system

Abstract

The utility model discloses an auditory system for an unmanned system, relates to the technical field of unmanned system perception, and can realize an acoustic independent positioning function by deploying a small-scale double-hemisphere array on the unmanned system. And with the detection and identification functions of a single sound array, intelligent sensing of environment sound field information under a small-scale array is realized. The intelligent hearing system can be provided for the unmanned system, detection, identification and directional distance measurement functions of circumferential 360-degree target sound can be realized, and the intelligent hearing system is combined with other information such as video module information, so that the unmanned system can sense multi-physical field information of the surrounding environment, and effective information support is provided for decision making and action of the unmanned system.

Description

Technical Field

[0001] The utility model relates to the technical field of unmanned system perception, in particular to an auditory system for an unmanned system based on a dual-hemisphere array. Background Art

[0002] Microphone arrays can be used as intelligent auditory systems for unmanned systems to realize detection functions such as acoustic signal detection, identification, and positioning of typical targets.

[0003] Linear arrays cannot distinguish between left and right directions, and only have good directional performance within a ±60° range around the perpendicular midline on one side of the array. The array manifold of a uniform linear array has a canonical Vandermonde form, leading to numerous optimized beamforming methods that exploit this property. This has led to the development of a relatively comprehensive sparse linear array theory.

[0004] Planar arrays are widely used, offering excellent beamforming performance within a conical area in front of the plane and are typically used for acoustic imaging. Currently, the most common planar arrays are multi-arm logarithmic spiral arrays or sunflower arrays, which offer better beamforming performance across a wider frequency band.

[0005] Spherical arrays can measure direction over 360° of both horizontal and vertical directions. Nearly uniformly distributed spherical arrays can perform modal beamforming in the spherical harmonic domain, achieving frequency-independent beam directivity within the analysis band. However, typically, only the upper hemisphere is required for spatial monitoring, so a hemispherical array can meet acoustic detection requirements.

[0006] A single acoustic array is typically only used for passive direction finding, not ranging and positioning. Traditional unmanned systems are mostly single arrays, and these arrays are only used for voice recognition and voice direction finding, and can only perform direction finding or other distance measurement methods such as laser ranging. Utility Model Content

[0007] In view of the above problems, the present invention provides a method for overcoming the above problems or at least partially solving the above problems.

[0008] The utility model provides the following solutions:

[0009] An auditory system for an unmanned system, comprising:

[0010] Two auditory modules, each comprising a hemispherical microphone array, wherein the hemispherical microphone array comprises a hemispherical structure body and a plurality of microphones evenly distributed on the hemispherical structure body for sampling;

[0011] The two hearing modules are spaced apart and respectively arranged on the front and rear sides of the back of the unmanned system;

[0012] The two auditory modules are both used to orient the same sound source, so that the positioning information of the sound source can be calculated using the orientation results of the two auditory modules.

[0013] Preferably, the hemispherical structural body comprises a rigid hemisphere with a radius of 42 mm.

[0014] Preferably, the number of the microphones is 16.

[0015] Preferably, the maximum modal order of the hemispherical microphone array is N=3, and the corresponding upper limit of the analysis frequency is 3867 Hz.

[0016] Preferably, the two hemispherical microphone arrays are obtained by equally dividing a 42 mm rigid sphere on which 32 microphones are evenly distributed.

[0017] Preferably: the unmanned system includes a quadruped robot, the quadruped robot includes a top plate, the top plate is provided with a plurality of reserved screw holes, the hemispherical structure body is provided with a plurality of mounting screw holes corresponding to the plurality of reserved screw holes, the hemispherical structure body and the top plate are connected to the top plate by bolts passing through the mounting screw holes and the corresponding reserved screw holes.

[0018] Preferably, a loading area is formed on the top plate between the two hearing modules.

[0019] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0020] The present application provides an auditory system for unmanned systems. By deploying a small-scale dual-hemispherical array on the unmanned system, it can achieve independent acoustic positioning. Combined with the detection and recognition capabilities of a single acoustic array, this system enables intelligent perception of ambient sound field information using a small-scale array. This system can provide an intelligent auditory system for unmanned systems, enabling detection, recognition, and directional ranging of target sounds in a 360-degree circumferential direction. Combined with other information, such as from video modules, this system can perceive multi-physical field information about its surroundings, providing effective information support for its decision-making and actions.

[0021] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0023] Figure 1 This is a schematic structural diagram of an auditory system for an unmanned system provided by an embodiment of the present utility model;

[0024] Figure 2 1 is a schematic structural diagram of a hemispherical microphone array provided by an embodiment of the present utility model;

[0025] Figure 3 This is a schematic diagram of the effective area of dual array positioning provided by an embodiment of the present utility model;

[0026] Figure 4 This is a structural block diagram of a sound type recognition algorithm provided by an embodiment of the present utility model.

[0027] In the figure: hemispherical microphone array 1, hemispherical structure body 11, microphone 12, unmanned system 2. DETAILED DESCRIPTION

[0028] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only 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 are within the scope of protection of the present invention.

[0029] See also Figure 1 , is an auditory system for an unmanned system provided by an embodiment of the present utility model, such as Figure 1 As shown, the system may include:

[0030] Two auditory modules, each comprising a hemispherical microphone array 1, wherein the hemispherical microphone array 1 comprises a hemispherical structural body and a plurality of microphones 12 evenly distributed on the hemispherical structural body 11 for sampling; in a specific implementation, the embodiment of the present application can provide that the hemispherical structural body 11 comprises a rigid hemisphere with a radius of 42 mm.

[0031] Furthermore, the microphones 12 include 16. The maximum modal order of the hemispherical microphone array 1 is N=3, and the corresponding upper limit of the analysis frequency is 3867 Hz. In order to further facilitate processing and manufacturing, the embodiment of the present application can also provide two hemispherical microphone arrays 1 obtained by equally dividing a 42 mm rigid sphere with 32 microphones evenly distributed thereon. Hemispherical arrays are more suitable for monitoring half-space areas and are easy to adapt to vehicle installation. Here, the spherical array is cut in half to form a hemispherical array, and the corresponding maximum modal order is reduced. The microphones are evenly distributed on the hemisphere, that is, the measurement of the surrounding space sound field has better symmetry.

[0032] The two auditory modules are spaced apart and respectively arranged on the front and rear sides of the back of the unmanned system 2;

[0033] The two auditory modules are both used to orient the same sound source, so that the positioning information of the sound source can be calculated using the orientation results of the two auditory modules.

[0034] It is understandable that the unmanned system provided by the embodiments of the present application may include multiple types. For example, in one implementation, the embodiments of the present application may provide that the unmanned system includes a quadruped robot, the quadruped robot includes a top plate, the top plate is provided with a plurality of reserved screw holes, the hemispherical structure body is provided with a plurality of mounting screw holes corresponding to the plurality of the reserved screw holes, and the hemispherical structure body is connected to the top plate by bolts passing through the mounting screw holes and the corresponding reserved screw holes. The two auditory modules coincide with the screw holes of the quadruped robot's top plate, so there is no need to drill separate screw holes for the auditory modules.

[0035] Furthermore, a loading area is formed on the top plate between the two auditory modules. The two modules are located on the front and rear sides, so as not to affect the robot dog's ability to carry other items. In actual deployment, the two auditory modules are placed as far apart as possible to ensure accurate positioning.

[0036] The auditory system for unmanned systems provided in the embodiments of this application can achieve broadband directional processing of low-frequency noise, enabling a single small-scale hemispherical array to perform detection, recognition, and orientation. Furthermore, target positioning can be achieved by combining the directional results of two hemispherical arrays. By installing a miniature hemispherical acoustic array at the front and rear of the unmanned system's back, the array aperture can be increased, improving direction-finding stability. Furthermore, the dual arrays, similar to the human ear, can better perceive spatial sound field information and improve positioning performance.

[0037] It is understandable that when the directional results of two arrays are used for directional intersection positioning, when the target is close to the direction of the line connecting the two arrays, the positioning deviation is too large. Therefore, it is more suitable to locate the sound source near the direction perpendicular to the direction of the array connection. Figure 3 The sector area shown.

[0038] The unmanned system auditory system provided in the embodiments of the present application can achieve 360° broadband circumferential directionality of low-frequency signals based on a small-scale (less than 10 cm) hemispherical array. Traditional arrays require large-scale arrays (meter-level) for low-frequency signal directionality. In addition, dual-hemispherical acoustic arrays with limited apertures achieve intersection positioning of circumferential targets. Traditional unmanned equipment mostly uses a single array and can only perform directionality or range measurement using other means such as laser ranging.

[0039] The following describes in detail the structure and implementation of the unmanned system auditory system provided in this application embodiment, using the example of an unmanned system auditory system installed on a robot dog. It is understood that when using this system for sound source orientation and localization, the required calculation methods can be implemented using existing methods, and the solution provided in this application does not involve any improvement to these calculation methods.

[0040] A spherical array is designed using a rigid sphere with a radius of 42 mm and 32 microphones distributed approximately evenly. The 16 microphones in the upper hemisphere and the hemispherical structure are taken to obtain the required 16-element hemispherical array, as shown in the following example: Figure 2 As shown in the figure, the maximum modal order N = 3, corresponding to an upper limit of the analysis frequency of 3867 Hz. Typical target noise primarily concentrates its energy in the mid- and low-frequency bands, particularly below 2000 Hz. Therefore, the designed hemispherical array meets acoustic detection requirements. During operation, a miniature hemispherical acoustic array is mounted on the back of the robot dog, at each end.

[0041] When performing target signal detection, sampling signals can be obtained from one micro-hemispherical acoustic array or from two micro-hemispherical acoustic arrays simultaneously. An energy detection algorithm, combined with the sampled signals, is used to determine whether the sampled signal contains the target signal. The energy detection algorithm compares the signal energy within a specific time period with a pre-set threshold to determine the presence of a target signal within that signal segment. The statistics and decision criteria for the energy detection algorithm can be expressed as:

[0042]

[0043] Where: T is the detection statistic, x(n) is the sampled signal, N is the number of sampling points, γ is the decision threshold, H1 is the presence of the target signal exceeding the threshold, and H0 is the absence of the target signal.

[0044] After determining that the target signal is present, the sound type of the signal needs to be identified. The embodiment of the present application uses a deep learning network such as a convolutional neural network (CNN) as the basis to build a deep learning recognition and classification network for typical target sounds. The structure diagram of the sound type recognition algorithm is shown in the figure. Figure 4 As shown in the figure, it includes model training and testing. Model training is the core, including modules such as data preparation, feature extraction, and model building and training.

[0045] After the sound type is determined, the sound source (target) can be oriented respectively by two hemispherical microphone arrays. After the orientation is completed, two directional results corresponding to the two hemispherical microphone arrays can be obtained. In the specific implementation, the system provided by this application adopts a receiving signal model based on a hemispherical sound array and uses spherical harmonic domain MVDR (SH-MVDR) for orientation. The MVDR method minimizes the impact of interference from the direction of undesired DOA on the array while maintaining a uniform gain in the observation direction. Based on the same principle, the power spectrum of SH-MVDR far-field source positioning can be expressed as:

[0046]

[0047] Similar to the SH-MUSIC sound source directional method, SH-MVDR also calculates the spatial spectrum in each direction by traversing spatial angles. The angle Ψ corresponding to the spectrum peak is the direction of the sound source.

[0048] After obtaining two directional results, the sound source can be located. Since two directional results are obtained, intersection positioning can be used to locate the sound source. In specific implementation, intersection positioning is the most common geometric positioning technology. Here, the angle of arrival (AOA) information of the two hemispherical arrays is used to establish a set of overdetermined equations and solve them using the least square method (LSM). The overdetermined equations including AOA information can be written as Ax = b:

[0049]

[0050] The z that can be further calculated is:

[0051]

[0052] Where: d i (z=z i ) means d i Projected modulus value on the horizontal plane.

[0053] The problem with this approach is that the estimation of the vertical coordinate z of the sound source is coupled with the errors in x and y. However, the advantage is that only the AOA of two arrays is needed to obtain a three-dimensional coordinate estimate. It is worth noting that in order to make A or b have physical meaning when taking any value within the horizontal angle range, the elements of A or b should not be represented by tangent or cotangent functions. At the same time, to avoid singularity of A or b, |Ψ i |Not all are π / 2.

[0054] In summary, the unmanned system auditory system provided by this application can achieve independent acoustic positioning by deploying a small-scale dual-hemispherical array in the unmanned system. Combined with the detection and recognition capabilities of a single acoustic array, intelligent perception of ambient sound field information under a small-scale array is achieved. An intelligent auditory system can be provided for unmanned systems, enabling detection, recognition, and directional ranging of target sounds in a 360-degree circumferential direction. Combined with other information such as video modules, this enables the unmanned system to perceive multi-physical field information of its surroundings, providing effective information support for its decision-making and actions.

[0055] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0056] Through the description of the above embodiments, it can be seen that those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary general hardware platform. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in various embodiments or certain parts of the embodiments of the present application.

[0057] Each embodiment in this specification is described in a progressive manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple. For relevant parts, refer to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without expending creative work.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. An auditory system for an unmanned system, characterized in that: include: Two auditory modules, each comprising a hemispherical microphone array, wherein the hemispherical microphone array comprises a hemispherical structure body and a plurality of microphones evenly distributed on the hemispherical structure body for sampling; The two hearing modules are spaced apart and respectively arranged on the front and rear sides of the back of the unmanned system; The two auditory modules are both used to orient the same sound source, so that the positioning information of the sound source can be calculated using the orientation results of the two auditory modules.

2. The hearing system for unmanned systems according to claim 1, wherein: The hemispherical structural body includes a rigid hemisphere with a radius of 42 mm.

3. The hearing system for unmanned systems according to claim 1, wherein: The number of the microphones is 16.

4. The hearing system for unmanned systems according to claim 3, characterized in that: The maximum modal order of the hemispherical microphone array is N=3, and the corresponding upper limit of the analysis frequency is 3867 Hz.

5. The hearing system for unmanned systems according to claim 3, characterized in that: The two hemispherical microphone arrays are obtained by equally dividing a 42 mm rigid sphere on which 32 microphones are evenly distributed.

6. The hearing system for unmanned systems according to claim 1, characterized in that: The unmanned system includes a quadruped robot, which includes a top plate, and a plurality of reserved screw holes are provided on the top plate. The hemispherical structure body is provided with a plurality of mounting screw holes corresponding to the plurality of reserved screw holes. The hemispherical structure body is connected to the top plate by bolts passing through the mounting screw holes and the corresponding reserved screw holes.

7. The hearing system for unmanned systems according to claim 6, characterized in that: The top plate is located between the two hearing modules to form a loading area.

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