Device and method for calibrating direction of sensor of acoustic array

Abstract

The invention discloses a sensor direction calibration device and method for an acoustic array, the device comprises the acoustic array and calibration equipment, the acoustic array comprises an acoustic sensor carrier, a plurality of acoustic sensors are uniformly distributed on the acoustic sensor carrier, and a satellite navigation antenna is arranged at the top of the middle of the acoustic sensor carrier and used for positioning the position of the acoustic array. A laser transmitter is arranged under one acoustic sensor to provide a physical reference standard for direction calibration of the acoustic sensor, and calibration equipment transmits position information of the calibration equipment to an acoustic array to be used for direction calibration of the acoustic sensor of the acoustic array. The laser transmitter is arranged right below one acoustic sensor of the acoustic array, the laser transmitter has a good visual guiding effect, physical alignment guiding of the acoustic array and calibration equipment is achieved, the convenience of calibration operation is improved, the equipment alignment process is simplified, complex operation of professionals is not needed, common operators can complete calibration, and the calibration efficiency is improved. The operation threshold is reduced, and the calibration time is saved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sound sensor direction calibration, and particularly relates to a sound array sensor direction calibration device and method. BACKGROUND

[0002] Sound array sensors are widely used in the fields of acoustic detection, environmental monitoring, target positioning, etc. due to their spatial resolution of sound signals. The measurement accuracy of sound array is highly dependent on the direction accuracy of each sound sensor. If there is a deviation between the actual orientation of the sound sensor and the theoretical design, it will directly lead to the calculation error of the angle of arrival of the sound signal, and further affect the accuracy of target positioning, and even cause misjudgment. Generally, a satellite positioning is installed on the sound array, and the position of the sound array can be accurately positioned. However, the direction of each sound sensor needs to be accurately calibrated. The traditional calibration method needs to place a sound source with a known position at a certain distance from the sound array. The sound array records the sound source information, and the direction of the sound sensor is calibrated by algorithm. This method is complex in operation and takes a long time to calibrate, which is not conducive to field operation. SUMMARY

[0003] The purpose of the present application is to provide a sound array sensor direction calibration device and method, which is simple in calibration operation, short in calibration time and high in calibration accuracy.

[0004] The present application is implemented by the following technical solutions:

[0005] In a first aspect, the present application provides a sound array sensor direction calibration device, which comprises a sound array and a calibration device. The sound array comprises a sound sensor carrier, a plurality of sound sensors are uniformly distributed on the sound sensor carrier, a satellite navigation antenna is arranged at the middle top of the sound sensor carrier for positioning the position of the sound array, and a laser emitter is arranged below one of the sound sensors to provide a physical reference for the direction calibration of the sound sensor. The calibration device transmits its position information to the sound array for the direction calibration of the sound sensor of the sound array.

[0006] Further, the calibration device comprises a calibration satellite navigation antenna, and the calibration satellite navigation antenna and the satellite navigation antenna use differential positioning technology to obtain the position information of the sound array and the calibration device.

[0007] Further, the laser emitter is used for emitting blue-green laser.

[0008] Further, the sound sensor carrier is disc-shaped.

[0009] Further, the position information is transmitted between the calibration device and the sound array in a wired manner.

[0010] Furthermore, the calibration device transmits position information to the acoustic array via a cable.

[0011] Furthermore, the calibration device and the acoustic array transmit location information wirelessly.

[0012] Secondly, another embodiment of the present invention provides a sensor orientation calibration method for an acoustic array, applicable to the acoustic array sensor orientation calibration device described in any of the above embodiments, the method comprising: Turn on the laser emitter on the acoustic array and move the calibration device into the illumination range of the laser emitter; The acoustic array receives location information transmitted by the calibration equipment. Based on the geodetic coordinates of the acoustic array and calibration equipment, the coordinates of the calibration equipment in the local north-pointing platform coordinate system are calculated through coordinate transformation. The orientation of the acoustic sensor above the laser emitter is obtained based on the coordinates of the calibration equipment in the local north-pointing platform coordinate system. Based on the spacing angle between each acoustic sensor, the orientation calibration of all sensors in the entire acoustic array is completed.

[0013] Furthermore, the specific method for calculating the coordinates of the calibration device in the local north-pointing platform coordinate system through coordinate transformation includes: Convert the geodetic coordinates of the acoustic array and calibration equipment to the geocentric coordinate system; Convert the geocentric coordinate system to the local north-pointing coordinate system with the center of the acoustic array as the origin.

[0014] Furthermore, the acoustic array receives position information transmitted by the calibration device via wired or wireless means.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0016] This invention provides a sensor orientation calibration device for an acoustic array. A laser emitter is positioned directly below one of the acoustic sensors in the acoustic array. The laser emitter provides excellent visual guidance, enabling physical alignment between the acoustic array and the calibration equipment. This improves the convenience of the calibration operation, simplifies the equipment alignment process, and eliminates the need for complex operations by specialized personnel. Ordinary operators can complete the calibration, lowering the operational threshold and saving calibration time. The calibration equipment is simple, portable, and beneficial for field calibration. The calibration satellite navigation antenna utilizes differential positioning technology to accurately acquire the position information of the acoustic array and the calibration equipment, providing high-precision data support for coordinate transformation and orientation calculation, and accurately calculating the orientation of the acoustic sensor.

[0017] This invention provides a sensor orientation calibration method for an acoustic array. A laser emitter provides visual alignment guidance, allowing operators to quickly complete the physical alignment of the acoustic array with the calibration equipment. This eliminates the cumbersome manual debugging steps of traditional technologies, improving the convenience of calibration operations and simplifying the equipment alignment process. No complex operations by professional personnel are required; ordinary operators can complete the calibration, lowering the operational threshold and saving calibration time. Simultaneously, differential positioning technology enables rapid acquisition of position information, resulting in a short overall calibration process and significantly improved work efficiency. The use of differential positioning technology ensures centimeter-level accuracy of position information, and combined with a clear coordinate system transformation calculation method, ensures the accuracy of coordinate transformation, ultimately achieving high-precision calibration of the acoustic sensor orientation and effectively reducing errors in acoustic signal detection and positioning. This method can be used in systems for sound source localization. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a schematic diagram of the structure of a sensor orientation calibration device for an acoustic array provided in the first embodiment of the present invention; Figure 2 A flowchart of a sensor orientation calibration method for an acoustic array provided in another embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0020] like Figure 1As shown, the first embodiment of the present invention provides a sensor orientation calibration device for an acoustic array, including an acoustic array 1 and a calibration device 2. The acoustic array 1 includes an acoustic sensor carrier 11, on which multiple acoustic sensors 12 are uniformly distributed. A satellite navigation antenna 13 is disposed at the top center of the acoustic sensor carrier 11 for locating the acoustic array itself. A laser emitter 14 is disposed directly below one of the acoustic sensors 12 to provide a physical reference for the orientation calibration of the acoustic sensors. The calibration device 2 transmits its own position information to the acoustic array for the orientation calibration of the acoustic sensors. The calibration device 2 includes a calibration satellite navigation antenna 21. The calibration satellite navigation antenna 21 and the satellite navigation antenna 13 use differential positioning technology to obtain the position information of the acoustic array and the calibration device.

[0021] The following is a detailed explanation using a circular acoustic array as an example: The acoustic array is the core sensing unit, and its structural design directly determines the basic accuracy of calibration. Specifically, it includes a disc-shaped acoustic sensor carrier with a circular structure and a diameter ranging from 20cm to 50cm. This size ensures a reasonable distribution of acoustic sensors while maintaining good portability for easy on-site installation and relocation. Acoustic sensors numbered 1 to n are evenly distributed on the disc-shaped carrier, with n ≥ 4. The angle between each sensor is a known fixed value, ensuring a clear spatial relationship between the sensors and providing a stable angular reference for subsequent direction calculations. A laser emitter is fixed directly below acoustic sensor number 1 and emits blue-green laser light. The laser emitter's power is controlled between 5mW and 20mW, ensuring effective laser irradiation distance while guaranteeing operator safety, facilitating rapid alignment of the calibration equipment. Simultaneously, the laser divergence angle is no greater than 0.5mrad, improving the directional accuracy of the laser irradiation. The laser emitter provides excellent visual guidance, enabling physical alignment guidance between the acoustic array and the calibration equipment, enhancing the convenience of calibration operations. The blue-green laser emitted by the laser emitter serves as a visual alignment marker, helping operators quickly move the calibration equipment within the effective calibration range of the acoustic array, simplifying the equipment positioning process before calibration. The blue-green laser is chosen for its good atmospheric penetration, reducing interference from ambient light on the aiming effect. A satellite navigation antenna is mounted on the top center of the disk-shaped acoustic sensor carrier to receive satellite positioning signals, enabling real-time positioning of the acoustic array itself. The calibration equipment includes a calibration satellite navigation antenna, which uses differential positioning technology to obtain the position information of the acoustic array and the calibration equipment. The acoustic array's satellite navigation antenna works in conjunction with the calibration equipment's calibration satellite navigation antenna to provide the raw signal for differential positioning. The calibration equipment and the acoustic array are connected via wired or wireless means. The calibration equipment can transmit its own position information to the acoustic array for acoustic sensor orientation calibration. In this embodiment, a cable is used for position information transmission to ensure stability and avoid data errors caused by wireless interference. The satellite navigation antenna used for calibrating the satellite navigation antenna and the acoustic array employs RTK (Real-Time Kinematic) differential positioning technology. This technology can eliminate systematic and environmental errors in satellite positioning, enabling positioning accuracy to reach the centimeter level, and providing high-precision data support for obtaining the relative position information of the acoustic array and calibration equipment.

[0022] Specifically, a 30cm diameter disc-shaped aluminum alloy carrier was selected as the acoustic sensor carrier, a material that combines lightweight design with structural stability. Six acoustic sensors are evenly distributed on the carrier, with adjacent sensors spaced at 60° intervals to ensure uniform spatial coverage. A 10mW blue-green laser emitter with a divergence angle of 0.3mrad is installed directly below the first acoustic sensor, and a satellite navigation antenna supporting RTK positioning is installed at the top center of the carrier. The calibration equipment uses an integrated RTK antenna and is connected to the acoustic array via a cable. Before calibration, the acoustic array is fixed to a support at the detection site, the laser emitter is turned on, and the operator moves the calibration equipment to the laser spot to complete the initial alignment.

[0023] The calibration process of the sensor orientation calibration device for the acoustic array provided in this embodiment of the invention is as follows: turn on the laser emitter on the acoustic array and move the calibration device to the illumination range of the laser emitter; the acoustic array receives the position information transmitted by the calibration device; calculate the coordinates of the calibration device in the local north-pointing platform coordinate system by coordinate transformation based on the geodetic coordinates of the acoustic array and the calibration device; obtain the orientation of the acoustic sensor above the laser emitter based on the coordinates of the calibration device in the local north-pointing platform coordinate system; and complete the orientation calibration of all acoustic sensors in the entire acoustic array based on the interval angle between each acoustic sensor.

[0024] This invention provides a sensor orientation calibration device for an acoustic array. A laser emitter is positioned directly below one of the acoustic sensors in the acoustic array. The laser emitter provides excellent visual guidance, enabling physical alignment between the acoustic array and the calibration equipment. This improves the convenience of the calibration operation, simplifies the equipment alignment process, and eliminates the need for complex operations by specialized personnel. Ordinary operators can complete the calibration, lowering the operational threshold and saving calibration time. The calibration equipment is simple, portable, and beneficial for field calibration. The calibration satellite navigation antenna utilizes differential positioning technology to accurately acquire the position information of the acoustic array and the calibration equipment, providing high-precision data support for coordinate transformation and orientation calculation, and accurately calculating the orientation of the acoustic sensor.

[0025] like Figure 2 As shown, another embodiment of the present invention provides a sensor orientation calibration method for an acoustic array, comprising the following steps: Turn on the laser emitter on the acoustic array and move the calibration device into the illumination range of the laser emitter; The acoustic array receives location information transmitted by the calibration equipment. Based on the geodetic coordinates of the acoustic array and calibration equipment, the coordinates of the calibration equipment in the local north-pointing platform coordinate system are calculated through coordinate transformation. The orientation of the acoustic sensor above the laser emitter is obtained based on the coordinates of the calibration equipment in the local north-pointing platform coordinate system. Based on the spacing angle between each acoustic sensor, the orientation calibration of all sensors in the entire acoustic array is completed.

[0026] The laser emitter on the acoustic array is activated, and the blue-green laser forms a clear visual guide mark. The operator moves the calibration equipment to bring it within the laser's illumination range, completing the initial physical alignment of the acoustic array and the calibration equipment, simplifying the pre-calibration positioning process.

[0027] Assume the geodetic coordinates obtained from navigation are (h, L, B), where h is the geodetic height, L is the geodetic longitude, and B is the geodetic latitude. Activate the satellite navigation antennas of the acoustic array and calibration equipment. Using RTK differential positioning technology, simultaneously acquire the geodetic coordinates (h1, L1, B1) of the acoustic array and (h2, L2, B2) of the calibration equipment, where h1 is the geodetic height of the acoustic array, L1 is the longitude of the acoustic array, and B1 is the latitude of the acoustic array; h2 is the geodetic height of the calibration equipment, L2 is the longitude of the calibration equipment, and B1 is the latitude of the calibration equipment. Centimeter-level positioning accuracy provides a reliable data foundation for subsequent coordinate transformation.

[0028] To calculate spatial relationships between different locations, the coordinates in the geodetic coordinate system need to be converted to the geocentric coordinate system (X,Y,Z). The conversion formula is as follows: ; ; ; Where: N - radius of curvature of the zonal circle, e - first eccentricity of the Earth, and X, Y, and Z are three coordinate values ​​in the geocentric coordinate system.

[0029] The geodetic coordinates of the acoustic array and the calibration equipment are converted to a geocentric coordinate system. The converted geocentric coordinate system of the acoustic array is (X1, Y1, Z1), and the geocentric coordinate system of the calibration equipment is (X2, Y2, Z2). The conversion formula is: ; ; ; ; ; .

[0030] Converting the geodetic coordinates (including longitude, latitude, and geodetic height) of the acoustic array and calibration equipment into geocentric coordinates eliminates regional differences in geographical coordinates, establishes a unified spatial location calculation benchmark, and facilitates accurate calculation of the relative positional relationship between the two.

[0031] To correlate location information with actual geographic orientation, the geocentric coordinate system needs to be converted to a local north-pointing platform coordinate system with the acoustic array as the origin. The x-axis of this coordinate system points to local north, the y-axis points to local east, and the z-axis points to the zenith. The transformation matrix is ​​as follows: ; In the formula: (x p y p , z p ( ) is the coordinate of the calibration device with the center of the acoustic array as the origin in the local north coordinate system.

[0032] Through the above matrix operations, the coordinates (x, y, y) of the calibration equipment in the local north coordinate system are obtained. p y p , z p Since the laser emitter is strongly correlated with the orientation of acoustic sensor No. 1, this coordinate directly reflects the actual orientation of acoustic sensor No. 1. Using this as a reference, combined with the known interval angles of each acoustic sensor, the orientation calibration of all sensors in the entire acoustic array can be completed.

[0033] This invention provides a sensor orientation calibration method for an acoustic array. A laser emitter provides visual alignment guidance, allowing operators to quickly complete the physical alignment of the acoustic array with the calibration equipment. This eliminates the cumbersome manual debugging steps of traditional technologies, improving the convenience of calibration operations and simplifying the equipment alignment process. No complex operations by professional personnel are required; ordinary operators can complete the calibration, lowering the operational threshold and saving calibration time. Simultaneously, differential positioning technology enables rapid acquisition of position information, resulting in a short overall calibration process and significantly improved work efficiency. The use of differential positioning technology ensures centimeter-level accuracy of position information, and combined with a clear coordinate system transformation calculation method, ensures the accuracy of coordinate transformation, ultimately achieving high-precision calibration of the acoustic sensor orientation and effectively reducing errors in acoustic signal detection and positioning. This method can be used in systems for sound source localization.

[0034] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A sensor orientation calibration device for an acoustic array, characterized in that, The system includes an acoustic array and a calibration device. The acoustic array includes an acoustic sensor carrier on which multiple acoustic sensors are evenly distributed. A satellite navigation antenna is set at the top center of the acoustic sensor carrier to locate the acoustic array's own position. A laser emitter is set directly below one of the acoustic sensors to provide a physical reference for the orientation calibration of the acoustic sensors. The calibration device transmits its own position information to the acoustic array for the orientation calibration of the acoustic sensors.

2. The sensor orientation calibration device for the acoustic array according to claim 1, characterized in that, The calibration equipment includes a calibration satellite navigation antenna, which uses differential positioning technology to obtain the position information of the acoustic array and the calibration equipment.

3. The sensor orientation calibration device for the acoustic array according to claim 1, characterized in that, The laser emitter is used to emit blue-green laser light.

4. The sensor orientation calibration device for the acoustic array according to claim 1, characterized in that, The acoustic sensor carrier is disc-shaped.

5. The sensor orientation calibration device for the acoustic array according to claim 1, characterized in that, The calibration device and the acoustic array transmit position information via a wired connection.

6. The sensor orientation calibration device for the acoustic array according to claim 5, characterized in that, The calibration device and the acoustic array transmit position information via cable.

7. The sensor orientation calibration device for the acoustic array according to claim 1, characterized in that, The calibration device and the acoustic array transmit location information wirelessly.

8. A method for calibrating the sensor orientation of an acoustic array, characterized in that, The method, applicable to the acoustic array sensor orientation calibration apparatus as described in any one of claims 1-7, comprises: Turn on the laser emitter on the acoustic array and move the calibration device into the illumination range of the laser emitter; The acoustic array receives location information transmitted by the calibration equipment. Based on the geodetic coordinates of the acoustic array and calibration equipment, the coordinates of the calibration equipment in the local north-pointing platform coordinate system are calculated through coordinate transformation. The orientation of the acoustic sensor above the laser emitter is obtained based on the coordinates of the calibration equipment in the local north-pointing platform coordinate system. Based on the spacing angle between each acoustic sensor, the orientation calibration of all sensors in the entire acoustic array is completed.

9. The sensor orientation calibration method for an acoustic array according to claim 8, characterized in that, The specific method for calculating the coordinates of the calibration device in the local north-pointing platform coordinate system through coordinate transformation includes: Convert the geodetic coordinates of the acoustic array and calibration equipment to the geocentric coordinate system; Convert the geocentric coordinate system to the local north-pointing coordinate system with the center of the acoustic array as the origin.

10. The sensor orientation calibration method for an acoustic array according to claim 8, characterized in that, The acoustic array receives position information transmitted by the calibration device via wired or wireless means.

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