Calibration system and method in a pool environment

Abstract

The present invention relates to a calibration system and method in a pool environment, belonging to the technical field of position calibration, comprising a pool body; a device to be calibrated, which is detachably and movably suspended inside the pool body by a suspension device; a position calibration plate arranged at a preset point, the preset point being based on the projection position of the device to be calibrated on the inner wall of the pool body along the X-axis or Y-axis when the device to be calibrated is in the desired position; a remote controller is used to control the suspension device to drive the device to be calibrated to move to the desired position, during which the laser light spot image at the projection point of the laser transmitter is captured by a camera device and sent to a host computer software; the host computer software determines the distance deviation of the device to be calibrated relative to the desired position based on the analysis of the laser light spot image, and sends the distance deviation to the remote controller, which performs position correction by controlling the suspension device. This achieves high-precision spatial positioning and dynamic correction of the device to be calibrated, improving calibration accuracy and efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of position calibration, and in particular to a calibration system and method in a pool environment. Background Art

[0002] At present, the wet-terminal terminal system of the target acoustic reflection coefficient measurement system usually consists of a sound source, a hydrophone and an underwater target. It works in a laboratory pool environment. The sound wave signal is emitted by the sound source, reflected by the underwater target and received by the hydrophone, thereby calculating the acoustic reflection characteristics of the target.

[0003] However, the existing wet terminal system has significant defects in actual measurement. Since the sound source, hydrophone and target object need to be fixed in the water pool by a hanging device, when changing the sound source frequency band or adjusting the target object's orientation, the equipment needs to be repeatedly lifted and re-hanged, resulting in the relative positions of the three being offset. The traditional calibration method relies on manual measurement of position using a ruler, which is inefficient and has limited accuracy, especially in deep water environments. It is difficult to ensure calibration accuracy. In addition, the lack of real-time monitoring means makes it impossible to dynamically correct position deviations, resulting in the inability to effectively compare multiple measurement results, seriously affecting the repeatability of the measurement and data reliability.

[0004] Existing techniques for underwater acoustic measurement usually use mechanical positioning devices or underwater rangefinders for position calibration. These devices only calibrate the alignment between the sound source and the hydrophone, but cannot solve the problem of dynamic calibration of the target object and do not consider the special needs of the laboratory tank environment. Summary of the Invention

[0005] In response to the shortcomings in the relevant technologies, the purpose of the present invention is to provide a calibration system and method in a water pool environment to solve the problem that when changing the sound source frequency band or adjusting the target object's orientation in the existing technology, the equipment needs to be repeatedly lifted and re-suspended, resulting in the relative positions of the three being offset. Position calibration in the field of underwater acoustic measurement usually uses a mechanical positioning device or an underwater rangefinder, which only calibrates the alignment between the sound source and the hydrophone, cannot solve the problem of dynamic calibration of the target object, and does not take into account the special needs of the laboratory water pool environment.

[0006] The present invention provides a calibration system in a pool environment, comprising:

[0007] The interior space of the pool body is defined by a three-dimensional rectangular coordinate system, wherein the three-dimensional rectangular coordinate system has the geometric center of the bottom surface of the pool body as the origin, the length direction parallel to the pool body as the X axis, the width direction parallel to the pool body as the Y axis, and the vertical upward direction as the Z axis;

[0008] The device to be calibrated is detachably and movably suspended inside the water tank by a suspension device;

[0009] A position calibration plate is arranged at a preset point, wherein the preset point is based on the projection position of the device to be calibrated on the inner wall of the pool along the X-axis direction or the Y-axis direction when the device to be calibrated is at the desired position;

[0010] A laser emitter, which is installed above the device to be calibrated and is used to project a laser light spot;

[0011] A camera device, installed above the device to be calibrated, for capturing an image of the laser spot;

[0012] A remote controller is communicatively connected to the laser emitter and the camera device, and is used to control the hanging device to drive the device to be calibrated to move to the desired position. During the movement, the camera device captures the laser spot image at the projection point of the laser emitter and sends it to a host computer software;

[0013] The host computer software is configured to: determine the distance deviation of the device to be calibrated relative to the expected position based on the analysis of the laser light spot image, and send the distance deviation to the remote controller, which performs position correction by controlling the hanging device.

[0014] The embodiments of the present invention establish a three-dimensional rectangular coordinate system and, through the collaborative operation of a laser transmitter, a camera, and host computer software, achieve high-precision spatial positioning and dynamic correction of the device to be calibrated. The light spot projected by the laser transmitter forms a spatial mapping relationship with the preset projection position of the position calibration plate. After the camera captures the light spot image in real time, the host computer software quantifies the position deviation through image analysis, thereby driving the hoisting device to adjust the position of the device to be calibrated. This solves the problem of positioning errors caused by water refraction or mechanical vibration in a pool environment, improving calibration accuracy and efficiency.

[0015] In some embodiments of the present invention, the device to be calibrated includes a hydrophone;

[0016] The hanging device for hanging the hydrophone includes a transverse load rod and a telescopic longitudinal load rod;

[0017] The transverse load rod is parallel to the Y-axis direction of the water pool body and is mounted on the wall surface of the water pool body in the X-axis direction, and is used to adjust the position of the hydrophone on the X-axis coordinate and the Y-axis coordinate;

[0018] The hydrophone, laser transmitter and camera equipment are installed at the bottom of the telescopic longitudinal load rod, which are used to adjust the position of the hydrophone on the Z-axis coordinate.

[0019] The embodiments of the present invention achieve flexible adjustment of the hydrophone in three dimensions through the combined design of a transverse load rod and a retractable longitudinal load rod. The transverse load rod is fixed to the pool wall along the Y-axis, ensuring horizontal displacement accuracy in the X and Y planes. The telescopic nature of the longitudinal load rod directly controls the Z-axis depth. The hydrophone, laser transmitter, and camera integrated at its base form an integrated sensing unit. This simplifies the complexity of the suspension device, ensuring both adjustment flexibility and stability, allowing the hydrophone to accurately reach its intended position and facilitating subsequent measurements.

[0020] In some embodiments of the present invention, the preset points for arranging the position marking signs are specifically:

[0021] The position marking plate is arranged on either side of the inner wall of the pool in the Y-axis direction, and is arranged at the projection position of the inner wall of the pool along the X-axis direction when the hydrophone is at the desired position.

[0022] This embodiment of the present invention establishes a detection benchmark for Y- and Z-axis deviation by precisely placing a position marker at the X-axis projection of the hydrophone's desired position. When the laser spot is projected onto the marker, the image captured by the camera only needs to analyze the pixel offsets in the Y and Z axes to resolve the position error, without relying on X-axis data. This simplifies the measurement process and improves both efficiency and accuracy.

[0023] In some embodiments of the present invention, the host computer software is further configured to:

[0024] After the laser transmitter projects a laser spot onto the position marking plate arranged at the projection position of the inner wall of the water pool along the X-axis direction when the hydrophone is at the desired position, an image of the laser spot sent by the remote controller is acquired;

[0025] The distance deviation of the hydrophone in the water pool in the Y-axis direction and the Z-axis direction is analyzed based on the laser spot image.

[0026] This embodiment of the present invention calculates the hydrophone's positional deviation by extracting the offset of the laser spot on a position calibration plaque. Using the plaque as a static reference system, the dynamic position of the spot is converted into spatial coordinate differences. This is more intuitive and reliable, avoiding manual measurement errors and enabling rapid and accurate position correction.

[0027] In some embodiments of the present invention, the device to be calibrated further includes a sound source and an underwater target, and the hanging device includes a turntable mechanism for hanging the sound source and / or the underwater target.

[0028] This embodiment of the present invention expands the compatibility of devices to be calibrated by introducing a turntable mechanism, enabling the system to simultaneously support the calibration requirements of a variety of devices, including sound sources and underwater targets. The turntable's rotational freedom allows the sound source or underwater target to adjust its azimuth around the Z axis, enhancing the system's versatility and meeting the calibration requirements of various underwater acoustic experiments.

[0029] In some embodiments of the present invention, the turntable mechanism includes:

[0030] A rotating platform, configured as a tabletop that rotates about the Z axis, the rotating platform being equipped with the sound source or the underwater target, a laser transmitter, and a camera device, and being used to drive the sound source or the underwater target to rotate;

[0031] A planar guide rail, comprising an X-direction slide rail and a Y-direction slide rail, wherein the X-direction slide rail is fixedly installed along the X-axis direction of the pool body, and the Y-direction slide rail is connected to the X-direction slide rail, and the planar guide rail is used to adjust the positions of the sound source and the underwater target in the X-axis coordinate and the Y-axis coordinate;

[0032] A fixed slide rail in the Z-axis direction, one end of which is fixedly connected to the Y-direction slide rail and the other end is connected to the rotating platform. The fixed slide rail in the Z-axis direction is used to adjust the position of the sound source or the underwater target in the Z-axis coordinate.

[0033] The embodiments of this invention achieve position control of a sound source or underwater target through the coordinated design of a planar guide rail, a fixed Z-axis slide rail, and a rotating platform. The planar guide rail provides a wide range of horizontal movement, the fixed Z-axis slide rail precisely adjusts depth, and the rotating platform allows for vertical rotation. Independent adjustment in each direction, combined with coordinated functionality, ensures the device can accurately reach any desired position, guaranteeing precise measurement.

[0034] In some embodiments of the present invention, the preset points for arranging the position marking signs further include:

[0035] The position marker is arranged on one side of the inner wall of the pool in the X-axis direction, and is arranged at the projection position of the inner wall of the pool along the Y-axis direction when the sound source or the underwater target is at the desired position;

[0036] The position marking plate is also arranged at the projection position of the inner wall of the pool body along the X-axis direction when the sound source or the underwater target is at the desired position, wherein the projection position along the X-axis direction of the inner wall of the pool body is respectively located in the Y-axis direction of the inner wall of the pool body close to the sound source or the underwater target.

[0037] In the embodiment of the present invention, when the sound source or underwater target moves, the laser spot can be projected onto the position calibration plate in the X-axis direction and the Y-axis direction respectively. By verifying the measurement results in different directions based on the laser spot graphic data, the reliability of the position calibration is improved and the measurement error is reduced.

[0038] In some embodiments of the present invention, the host computer software is further configured to:

[0039] After the laser transmitter projects a laser spot toward the position marker at the projected position along the Y-axis on the inner wall of the pool body when the sound source or the underwater target is at the desired position, an image of the laser spot sent by the remote controller is acquired;

[0040] Analyze the distance deviation of the sound source or the underwater target in the water pool in the X-axis direction and the Z-axis direction according to the laser light spot image;

[0041] After the laser transmitter projects a laser spot toward the position marker at the projected position along the X-axis direction on the inner wall of the pool body when the sound source or the underwater target is at the desired position, an image of the laser spot sent by the remote controller is acquired;

[0042] The distance deviation of the sound source or the underwater target in the water pool in the X-axis direction and the Z-axis direction is analyzed based on the laser light spot image.

[0043] This embodiment of the present invention projects laser light onto position calibration plaques in the Y-axis and X-axis directions, calculating position errors in different planes separately. Finally, three-dimensional deviations are obtained through data fusion. This method comprehensively considers the positional deviations of sound sources or underwater targets in all directions, providing more comprehensive correction suggestions. This avoids the potential for error accumulation caused by single-direction measurement, thereby improving calibration speed while maintaining accuracy.

[0044] In some embodiments of the present invention, the position calibration plate includes a reference point, and the host computer software analyzes the distance deviation to the device to be calibrated in the X-axis direction, Y-axis direction and Z-axis direction respectively based on the position deviation between the laser point position of the laser light spot image and the reference point position.

[0045] This embodiment of the present invention utilizes the relative positional relationship between the reference point on the position calibration plaque and the laser spot to achieve intuitive and quantitative analysis of position deviations. The host computer software simply calculates the pixel displacement between the laser point and the reference point, and, based on the physical dimensions of the position calibration plaque, directly converts this into actual spatial deviation. This simplifies the algorithmic process and allows operators to directly observe the adjustment effects through a graphical interface, enhancing the user-friendly human-computer interaction.

[0046] Some embodiments of the present invention further provide a calibration method in a pool environment, characterized by comprising the following steps:

[0047] Hanging step: detachably and movably hang the device to be calibrated inside the water tank by a hanging device, and arrange the position calibration plate at a preset point based on the projection position of the device to be calibrated on the inner wall of the water tank along the X-axis direction or the Y-axis direction when the device to be calibrated is at a desired position;

[0048] Image acquisition step: controlling the hanging device through a remote controller to drive the device to be calibrated to the desired position, capturing the laser spot image at the projection point of the laser transmitter installed on the hanging device through a camera installed on the hanging device, and sending the image to the host computer software;

[0049] Position adjustment step: the host computer software determines the distance deviation of the device to be calibrated relative to the desired position based on the analysis of the laser spot image, and sends the distance deviation to the remote controller, which performs position correction by controlling the hanging device;

[0050] Target acoustic reflection coefficient calculation step: checking the distance deviation through the position calibration plate, measuring the target acoustic reflection coefficient under the current frequency band, replacing the device to be calibrated on the hanging device with the next device to be calibrated, repeating the image acquisition step and the position adjustment step until the measurement of the target acoustic reflection system of all targets to be measured is completed.

[0051] The embodiments of the present invention use a calibration method to standardize the calibration process into a four-step cycle of hoisting, image acquisition, position adjustment, and acoustic measurement, forming a reusable operating method. Real-time verification of the position calibration plate ensures that the device to be calibrated is in the desired position before each frequency band measurement, thereby eliminating the impact of mechanical errors on the acoustic reflection coefficient. When different sound sources or underwater targets are replaced, the calibration process is automatically repeated to ensure that data at each frequency point is collected under the same spatial conditions. This improves experimental efficiency and reduces the uncertainty introduced by human operation through automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0053] Figure 1 A front view of a calibration system structure of a device to be calibrated provided in an embodiment of the present invention;

[0054] Figure 2A top view of a calibration system structure of a device to be calibrated provided in an embodiment of the present invention;

[0055] Figure 3 A structural diagram of a hydrophone hanging device provided in an embodiment of the present invention;

[0056] Figure 4 A front view of a hydrophone calibration system structure provided by an embodiment of the present invention;

[0057] Figure 5 A top view of a hydrophone calibration system structure provided by an embodiment of the present invention;

[0058] Figure 6 A front view of a calibration system structure for a sound source and an underwater target provided by an embodiment of the present invention;

[0059] Figure 7 A top view of a calibration system structure for a sound source and underwater target provided by an embodiment of the present invention;

[0060] Figure 8 A schematic diagram of a location marking plate provided in an embodiment of the present invention;

[0061] Figure 9 This is a flow chart of a calibration method in a pool environment provided by an embodiment of the present invention.

[0062] In the picture:

[0063] 100. Pool body;

[0064] 200, device to be calibrated; 201, hydrophone; 202, sound source; 203, underwater target;

[0065] 300, position calibration plate; 301, first position calibration plate; 302, second position calibration plate; 303, third position calibration plate; 304, fourth position calibration plate; 305, fifth position calibration plate; 306, sixth position calibration plate;

[0066] 400, laser emitter; 401, first laser emitter; 402, second laser emitter; 403, third laser emitter

[0067] 500, camera device; 501, first camera device; 502, second camera device; 503, third camera device;

[0068] 600, hanging device; 611, transverse load rod; 612, longitudinal load rod; 620, turntable mechanism; 621, first turntable mechanism; 622, second turntable mechanism. DETAILED DESCRIPTION

[0069] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is described and illustrated below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely used to explain this application and are not intended to limit this application. Based on the embodiments provided in this application, all other embodiments obtained by those of ordinary skill in the art without making any creative efforts are within the scope of protection of this application.

[0070] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0071] The target acoustic reflection coefficient refers to the ratio of reflected sound energy to incident sound energy when a sound wave encounters a target object underwater. It can reflect the target object's size, shape, material and other characteristic information. It is an important parameter that must be considered in the stealth design of underwater targets, and is also an important basic data for sonar to achieve target detection and identification.

[0072] With the development of new detection technologies and the development of new underwater equipment, the signal-to-noise ratio of underwater targets is getting lower and lower. The requirements for analyzing the acoustic reflection characteristics of underwater targets are becoming increasingly stringent, which inevitably requires a more in-depth and detailed understanding of the target acoustic reflection coefficient. Therefore, the demand for high-precision measurement of the target acoustic reflection coefficient is very urgent, which is of great significance to the fields of underwater target identification, precision acoustic guidance, anti-stealth and marine development.

[0073] In the field of underwater acoustic measurement, the measurement system for measuring the target's acoustic reflection coefficient is divided into two subsystems: wet-terminal systems and dry-terminal systems. The wet-terminal system operates in a laboratory tank environment and its main function is to transmit sound waves underwater, stimulate the underwater target to reflect the sound waves, and receive the reflected sound waves from the underwater target.

[0074] A wet-terminal system consists of a sound source, a hydrophone, and an underwater target, all suspended at a constant depth in a water tank by a rigging device. Measuring the acoustic reflection coefficient of an underwater target typically involves using a stable sound source to generate sound, while the hydrophone collects the reflected sound waves. Based on the principle of sound wave propagation, sound energy attenuates with distance in an anechoic tank. Therefore, any deviation in the relative positions of the sound source, hydrophone, and underwater target within the tank can significantly affect the measurement of the underwater target's acoustic reflection coefficient.

[0075] In the experimental water pool, since the positions of the sound source, hydrophone and target object are difficult to fix, the changes in the relative positions of the three have a great impact on the measurement results, seriously affecting the accuracy and repeatability of the measurement results.

[0076] In addition, measuring the target sound reflection coefficient in different frequency bands requires replacing the sound source, measuring different underwater targets requires replacing the underwater targets, and measuring the target sound reflection coefficient at different positions of the device to be calibrated requires adjusting the orientation of the device to be calibrated. The replacement and adjustment process involves the lifting and re-hanging of the sound source and underwater target, and the position of the underwater target, sound source, and hydrophone needs to be recalibrated.

[0077] The existing calibration method relies on ruler measurement, which is inefficient and has poor accuracy. It also lacks effective underwater observation methods, which inevitably leads to distance measurement errors. The sound source and underwater target will produce position offsets after being re-suspended, making it impossible to compare multiple measurement results of the target sound reflection coefficient horizontally, and the measurement efficiency is low.

[0078] In the absence of conflict, the embodiments of the present invention and the features thereof may be combined with each other.

[0079] The technical solution of the present invention is described in detail below in conjunction with specific embodiments and the accompanying drawings.

[0080] like Figures 1 to 2 As shown, the present invention provides a calibration system in a pool environment, comprising:

[0081] The interior space of the pool body 100 is defined by a three-dimensional rectangular coordinate system, wherein the three-dimensional rectangular coordinate system has the geometric center of the bottom surface of the pool body 100 as the origin, the length direction parallel to the pool body 100 as the X-axis, the width direction parallel to the pool body 100 as the Y-axis, and the vertical upward direction as the Z-axis;

[0082] The device to be calibrated 200 is detachably and movably suspended inside the water tank body 100 by a suspension device 600;

[0083] The position marking plate 300 is arranged at a preset point, and the preset point is based on the projection position of the device to be calibrated 200 on the inner wall of the pool body 100 along the X-axis direction or the Y-axis direction when the device to be calibrated 200 is at the desired position;

[0084] A laser emitter 400 is mounted above the device to be calibrated 200 and is used to project a laser light spot;

[0085] A camera device 500 is installed above the device to be calibrated 200 and is used to capture the laser light spot image; optionally, the camera device 500 and the laser emitter 400 are both installed at the bottom of the hanging device 600 and integrated at the same horizontal plane;

[0086] The remote controller is communicatively connected to the laser emitter 400 and the camera device 500, and is used to control the hanging device 600 to move the device to be calibrated 200 to the desired position. During the movement, the camera device 500 captures the laser spot image at the projection point of the laser emitter 400 and sends it to a host computer software;

[0087] The upper computer software is configured to: determine the distance deviation of the device to be calibrated 200 relative to the expected position based on the analysis of the laser spot image, and send the distance deviation to the remote controller, which performs position correction by controlling the hanging device 600.

[0088] Based on this system, by establishing a three-dimensional rectangular coordinate system and integrating the laser emitter 400, camera 500, and host computer software, high-precision spatial positioning and dynamic correction of the device 200 to be calibrated are achieved. The light spot projected by the laser emitter 400 forms a spatial mapping relationship with the preset projection position of the position calibration plate 300. After the camera 500 captures the light spot image in real time, the host computer software quantifies the position deviation through image analysis, thereby driving the hanging device 600 to adjust the position of the device 200 to be calibrated. This solves the problem of positioning errors caused by water refraction or mechanical vibration in a pool environment, improving calibration accuracy and efficiency.

[0089] In some embodiments of the present invention, the device to be calibrated 200 includes a hydrophone 201;

[0090] The suspending device 600 for suspending the hydrophone 201 includes a transverse load rod 611 and a telescopic longitudinal load rod 612;

[0091] The transverse load rod 611 is parallel to the Y-axis direction of the pool body 100 and is mounted on the wall surface of the pool body 100 in the X-axis direction, and is used to adjust the position of the hydrophone 201 on the X-axis coordinate and the Y-axis coordinate;

[0092] The hydrophone 201 , the laser transmitter 400 and the camera device 500 are installed at the bottom of the telescopic longitudinal load rod 612 , and are used to adjust the position of the hydrophone 201 on the Z-axis coordinate.

[0093] The combined design of a transverse load rod 611 and a retractable longitudinal load rod 612 enables flexible adjustment of the hydrophone 201 in three dimensions. The transverse load rod 611 is fixed to the pool wall along the Y-axis, ensuring horizontal displacement accuracy in the X and Y planes. The retractable nature of the longitudinal load rod 612 directly controls the Z-axis depth. The hydrophone 201, laser transmitter 400, and camera 500 integrated at its base form an integrated sensing unit. This simplifies the complexity of the suspension device 600, ensuring both flexibility and stability, allowing the hydrophone 201 to accurately reach its intended position and facilitating subsequent measurements.

[0094] In some embodiments of the present invention, the preset points where the position marking signs 300 are arranged are specifically:

[0095] The position marker 300 is arranged on either side of the inner wall of the pool body 100 in the Y-axis direction and is arranged at the projection position of the inner wall of the pool body 100 along the X-axis direction when the hydrophone 201 is at the desired position.

[0096] By precisely placing the position marker 300 at the X-axis projection of the desired position of the hydrophone 201, a detection benchmark for Y- and Z-axis deviation is established. When the laser spot is projected onto the position marker 300, the image captured by the camera 500 only needs to analyze the pixel offsets in the Y and Z axes to resolve the position error, without relying on X-axis data. This simplifies the measurement process and improves both efficiency and accuracy.

[0097] In some embodiments of the present invention, the host computer software is further configured to:

[0098] The laser transmitter 400 projects a laser spot onto the position marker 300 arranged at the projection position along the X-axis direction on the inner wall of the pool body 100 when the hydrophone 201 is at the desired position, and then acquires the laser spot image sent by the remote controller;

[0099] The distance deviation of the hydrophone 201 in the water pool 100 in the Y-axis direction and the Z-axis direction is analyzed based on the laser spot image.

[0100] The position deviation of hydrophone 201 is calculated by extracting the offset of the laser spot on position calibration plate 300. Using position calibration plate 300 as a static reference system, the dynamic position of the laser spot is converted into spatial coordinate differences, which is more intuitive and reliable, avoiding manual measurement errors and achieving fast and accurate position correction.

[0101] Specifically, if Figure 3 As shown, the transverse load rod 611 is mounted on the wall of the pool body 100 in the X-axis direction, and the hydrophone 201, the third laser emitter 403 and the third camera device 503 are installed at the bottom of the retractable longitudinal load rod 612, wherein the third laser emitter 403 and the third camera device 503 are integrated on the same horizontal plane and are located above the hydrophone 201.

[0102] like Figures 4 and 5 As shown, a second position marking plate 302 is arranged on the Y-axis direction of one side of the inner wall of the pool body 100, and the second position marking plate 302 is arranged at the projection position of the inner wall of the pool body 100 along the X-axis direction when the hydrophone 201 is at the desired position;

[0103] A fifth position marking plate 305 is arranged on the Y-axis direction on the other side of the inner wall of the pool body 100 , and the fifth position marking plate 305 is arranged at the projection position of the inner wall of the pool body 100 along the X-axis direction when the hydrophone 201 is at the desired position.

[0104] Turn on the third laser emitter 403, and project a laser spot onto the second position marking plate 302 or the fifth position marking plate 305. The remote controller captures the laser spot image through the third camera 503 and sends it to the host computer software;

[0105] The upper computer software analyzes the distance deviation of the hydrophone 201 in the Y-axis direction and the Z-axis direction in the water pool body 100 based on the laser spot image.

[0106] The position of the transverse load rod 611 in the Y-axis direction and the length of the longitudinal load rod 612 are adjusted until the distance deviation is within a preset error range.

[0107] Optionally, based on the target acoustic reflection coefficient measurement algorithm and multiple actual measurement experiences, the error range of the distance deviation is set to 1 cm. Multiple measurement results of the target acoustic reflection coefficient can be compared horizontally to ensure that the measurement error is within an acceptable range.

[0108] In some embodiments of the present invention, the device to be calibrated 200 further includes a sound source 202 and an underwater target 203 , and the suspending device 600 includes a turntable mechanism 620 for suspending the source and / or the underwater target 203 .

[0109] By introducing a turntable mechanism 620, the compatibility of the device to be calibrated 200 is expanded, enabling the system to simultaneously support the calibration requirements of multiple devices, such as the sound source 202 and the underwater target 203. The rotational freedom of the turntable mechanism 620 allows the sound source 202 or the underwater target 203 to adjust their azimuth around the Z axis, enhancing the system's versatility and meeting the calibration requirements of various types of underwater acoustic experiments.

[0110] The turntable mechanism 620 includes:

[0111] A rotating platform is provided as a tabletop that rotates about the Z axis. The rotating platform is equipped with a sound source 202 or an underwater target 203, a laser transmitter 400, and a camera device 500, and is used to drive the sound source 202 or the underwater target 203 to rotate;

[0112] Planar guide rails, including an X-direction slide rail and a Y-direction slide rail, wherein the X-direction slide rail is fixedly installed along the X-axis direction of the pool body 100, and the Y-direction slide rail is connected to the X-direction slide rail. The planar guide rails are used to adjust the positions of the sound source 202 and the underwater target 203 in the X-axis coordinate and the Y-axis coordinate;

[0113] The Z-axis fixed slide rail has one end fixedly connected to the Y-axis slide rail and the other end connected to the rotating platform. The Z-axis fixed slide rail is used to adjust the position of the sound source 202 or the underwater target 203 in the Z-axis coordinate.

[0114] The coordinated design of a planar guide rail, a fixed Z-axis slide, and a rotating platform enables position control of the sound source 202 or underwater target 203. The planar guide rail provides a wide range of horizontal motion, the fixed Z-axis slide rail precisely adjusts depth, and the rotating platform allows for vertical rotation. Independent adjustment in each direction, while coordinated with each other, ensures the device can accurately reach any desired position, guaranteeing precise measurement.

[0115] In some embodiments of the present invention, the preset points of the position marking plate 300 further include:

[0116] The position marker 300 is arranged on one side of the inner wall of the pool body 100 in the X-axis direction and is arranged at the projection position of the sound source 202 or the underwater target 203 on the inner wall of the pool body 100 along the Y-axis direction when the sound source 202 or the underwater target 203 is at the desired position;

[0117] The position marker 300 is also arranged at the projection position of the sound source 202 or the underwater target 203 on the inner wall of the pool body 100 along the X-axis direction when the sound source 202 or the underwater target 203 is at the desired position, wherein the projection position along the X-axis direction on the inner wall of the pool body 100 is located in the Y-axis direction of the inner wall of the pool body 100 close to the sound source 202 or the underwater target 203.

[0118] When the sound source 202 or the underwater target 203 moves, the laser light spot can be projected onto the position calibration plate 300 in the X-axis direction and the Y-axis direction respectively. By verifying the measurement results in different directions based on the laser light spot graphic data, the reliability of the position calibration is improved and the measurement error is reduced.

[0119] In some embodiments of the present invention, the host computer software is further configured to:

[0120] The laser transmitter 400 projects a laser spot onto the position marker 300 of the projection position of the sound source 202 or the underwater target 203 along the Y-axis direction on the inner wall of the pool body 100 when the sound source 202 or the underwater target 203 is at the desired position, and then obtains the laser spot image sent by the remote controller;

[0121] Analyze the distance deviation of the sound source 202 or the underwater target 203 in the X-axis direction and the Z-axis direction in the pool body 100 based on the laser light spot image;

[0122] The laser transmitter 400 projects a laser spot onto the position marker 300 of the projection position of the sound source 202 or the underwater target 203 along the X-axis direction on the inner wall of the pool body 100 when the sound source 202 or the underwater target 203 is at the desired position, and then obtains the laser spot image sent by the remote controller;

[0123] The distance deviations of the sound source 202 or the underwater target 203 in the X-axis direction and the Z-axis direction in the pool body 100 are analyzed based on the laser spot image.

[0124] By projecting laser light onto the position calibration plaque 300 in the Y-axis and X-axis directions, position errors in different planes are calculated separately, and finally, three-dimensional deviations are obtained through data fusion. This system comprehensively considers the positional deviations of the sound source 202 or underwater target 203 in all directions, providing more comprehensive correction suggestions. This avoids the error accumulation that can result from single-direction measurement, thereby improving calibration speed while maintaining accuracy.

[0125] Specifically, if Figures 6 and 7 As shown, the sound source 202 is mounted on the rotating platform of the first turntable mechanism 621 and suspended in the water pool body 100 .

[0126] The sound source 202 , the first laser emitter 401 and the first camera device 501 are installed on the rotating platform of the first turntable mechanism 621 , wherein the first laser emitter 401 and the first camera device 501 are integrated on the same horizontal plane and are located above the sound source 202 .

[0127] A first position marking plate 301 is arranged on one side of the inner wall of the pool body 100 in the X-axis direction, and the first position marking plate 301 is arranged at the projection position of the inner wall of the pool body 100 along the Y-axis direction when the sound source 202 is at the desired position;

[0128] A third position marking plate 303 is also arranged in the X-axis direction on the other side of the inner wall of the pool body 100, and the third position marking plate 303 is arranged at the projection position along the Y-axis direction on the inner wall of the pool body 100 when the sound source 202 is at the desired position, wherein the third position marking plate 303 is opposite to the position of the first position marking plate 301.

[0129] The second position marking plate 302 is arranged on a side of the inner wall of the pool body 100 close to the sound source 202 in the Y-axis direction.

[0130] A command is sent to the first turntable mechanism 621 through the remote controller, and the rotating platform of the first turntable mechanism 621 drives the sound source 202 to rotate one circle.

[0131] Turn on the first laser emitter 401 and project laser spots onto the first position marking plate 301, the second position marking plate 302, and the third position marking plate 303 respectively. The remote controller captures the laser spot images through the first camera device 501 and sends them to the host computer software.

[0132] The upper computer software analyzes the distance deviation of the sound source 202 in the X-axis direction and the Z-axis direction in the water pool body 100 based on the laser light spot image of the first position calibration plate 301;

[0133] The upper computer software analyzes the distance deviation of the sound source 202 in the Y-axis direction and the Z-axis direction in the pool body 100 based on the laser light spot image of the second position calibration plate 302.

[0134] The position of the sound source 202 in the X-axis and Y-axis directions is adjusted by the planar guide rail of the first turntable mechanism 621, and the telescopic length is adjusted by the fixed slide rail in the Z-axis direction of the first turntable mechanism 621 until the distance deviation is within the preset error range.

[0135] The upper computer software checks whether the distance deviation is within a preset error range based on the laser spot image of the third position calibration plate 303 .

[0136] Specifically, as attached Figures 6 and 7 As shown, the underwater target 203 is mounted on the rotating platform of the second turntable mechanism 622 and suspended in the water pool body 100 .

[0137] The underwater target 203 , the second laser emitter 402 and the second camera device 502 are installed on the rotating platform of the second turntable mechanism 622 , wherein the second laser emitter 402 and the second camera device 502 are integrated on the same horizontal plane and are located above the underwater target 203 .

[0138] A fourth position marking plate 304 is arranged on one side of the inner wall of the pool body 100 in the X-axis direction, and the fourth position marking plate 304 is arranged at the projection position of the inner wall of the pool body 100 along the Y-axis direction when the underwater target 203 is at the desired position;

[0139] A sixth position marking plate 306 is also arranged in the X-axis direction on the other side of the inner wall of the pool body 100, and the sixth position marking plate 306 is arranged at the projection position along the Y-axis direction of the inner wall of the pool body 100 when the sound source 202 is at the desired position, wherein the sixth position marking plate 306 is opposite to the position of the fourth position marking plate 304.

[0140] The fifth position marking plate 305 is arranged on a side of the inner wall of the pool body 100 close to the underwater target 203 in the Y-axis direction.

[0141] A command is sent to the second turntable mechanism 622 via the remote controller, and the rotating platform of the second turntable mechanism 622 drives the underwater target 203 to rotate one circle.

[0142] Turn on the second laser emitter 402 and project laser spots onto the fourth position marking plate 304, the fifth position marking plate 305, and the sixth position marking plate 306, respectively. The remote controller captures the laser spot images through the second camera 502 and sends them to the host computer software.

[0143] The upper computer software analyzes the distance deviation of the sound source 202 in the X-axis direction and the Z-axis direction in the water pool body 100 based on the laser light spot image of the fourth position calibration plate 304;

[0144] The upper computer software analyzes the distance deviation of the sound source 202 in the Y-axis direction and the Z-axis direction in the water pool body 100 based on the laser light spot image of the fifth position calibration plate 305 .

[0145] The position of the underwater target 203 in the X-axis and Y-axis directions is adjusted by the planar guide rail of the second turntable mechanism 622, and the telescopic length is adjusted by the fixed slide rail in the Z-axis direction of the second turntable mechanism 622 until the distance deviation is within the preset error range.

[0146] The upper computer software checks whether the distance deviation is within a preset error range based on the laser spot image of the sixth position calibration plate 306 .

[0147] In some embodiments of the present invention, Figure 8 As shown, the position calibration plate 300 includes a reference point. The upper computer software analyzes the distance deviation to the device to be calibrated 200 in the X-axis direction, Y-axis direction and Z-axis direction respectively based on the position deviation between the laser point position of the laser spot image and the reference point position.

[0148] Specifically, if Figure 8 As shown, a plane rectangular coordinate system is set according to the reference point in the position calibration plate 300, and a precise scale is drawn. The accurate value of the distance deviation of the device to be calibrated 200 in the three-dimensional direction is analyzed according to the scale position of the laser point in the laser spot image on the position calibration plate 300 and the position deviation between the laser point and the reference point.

[0149] The relative positional relationship between the reference point on the position calibration plaque 300 and the laser spot enables intuitive and quantitative analysis of position deviation. The host computer software simply calculates the pixel displacement between the laser point and the reference point and, based on the physical dimensions of the position calibration plaque 300, directly converts this into actual spatial deviation. This simplifies the algorithmic process and allows operators to directly observe the adjustment effects through a graphical interface, enhancing the user-friendly interface.

[0150] like Figure 9 As shown, some embodiments of the present invention further provide a calibration method in a pool environment, characterized by comprising the following steps:

[0151] Hanging step S1: The device to be calibrated is detachably and movably hung inside the water tank by a hanging device, and a position calibration plate is arranged at a preset point based on the projection position of the device to be calibrated on the wall of the water tank along the X-axis direction or the Y-axis direction when the device to be calibrated is at the desired position;

[0152] Image acquisition step S2: The remote controller controls the hanging device to move the device to be calibrated to the desired position, and the camera installed on the hanging device captures the laser spot image at the projection point of the laser transmitter installed on the hanging device and sends it to the host computer software;

[0153] Position adjustment step S3: The host computer software determines the distance deviation of the device to be calibrated relative to the expected position based on the laser spot image analysis, and sends the distance deviation to the remote controller. The remote controller corrects the position by controlling the hanging device;

[0154] Target acoustic reflection coefficient calculation step S4: Check the distance deviation through the position calibration plate, measure the target acoustic reflection coefficient in the current frequency band, replace the device to be calibrated on the hanging device with the next device to be calibrated, repeat the image acquisition step S2 and position adjustment step S3 until the target acoustic reflection system measurement of all targets to be measured is completed.

[0155] Specifically, the device to be calibrated includes a sound source, a hydrophone, and an underwater target object; after the position calibration of the sound source, the hydrophone, and the underwater target object is completed, the target sound reflection coefficient is measured.

[0156] The remote controller sends instructions to the signal generator to control the sound source to emit sound waves of a specified frequency, and the hydrophone receives the sound wave signal; the remote controller sends instructions to the signal collector to process the sound wave signal received by the hydrophone, and uses the target sound reflection coefficient measurement algorithm to calculate the target sound reflection coefficient in the frequency band.

[0157] Replace the sound source of the next measurement frequency band onto the first turntable mechanism, repeat the image acquisition step S2 and the position adjustment step S3, recalibrate the position of the sound source, and continue to repeat the target sound reflection coefficient calculation step S4 to measure the target sound reflection coefficient of the next frequency band until the measurement of the target sound reflection coefficients of all frequency bands is completed.

[0158] Replace the next underwater target onto the second turntable mechanism, repeat the image acquisition step S2 and the position adjustment step S3, recalibrate the position of the underwater target, and continue to repeat the target acoustic reflection coefficient calculation step S4 to measure the target acoustic reflection coefficient of the next target to be measured, until the measurement of the target acoustic reflection coefficients of all targets to be measured is completed.

[0159] It should be noted that the sound source and hydrophone need to be calibrated regularly, and the immersion time in the pool should not exceed 15 days each time.

[0160] The calibration method described above standardizes the calibration process into a four-step cycle of hoisting, image acquisition, position adjustment, and acoustic measurement, creating a reusable protocol. Real-time calibration of the position calibration plate ensures that the device to be calibrated is in the desired position before each frequency band measurement, eliminating the impact of mechanical errors on the acoustic reflection coefficient. When changing sound sources or underwater targets, the calibration process is automatically repeated to ensure that data at each frequency point is collected under the same spatial conditions. This improves experimental efficiency and reduces the uncertainty introduced by manual operation through automation.

[0161] It should be noted that the above is a reference method for a calibration system and method in a pool environment, and the present invention is not limited thereto.

[0162] The embodiments of the present invention achieve high-precision spatial positioning and dynamic correction of the device to be calibrated. The light spot projected by the laser transmitter forms a spatial mapping relationship with the preset projection position of the position calibration plate. After the camera device captures the light spot image in real time, the host computer software quantifies the position deviation through image analysis, and then drives the hanging device to adjust the position of the device to be calibrated. This solves the technical problem that when changing the sound source frequency band or adjusting the target object orientation in the existing technology, the device needs to be repeatedly lifted and re-hanged, resulting in the relative position offset of the three. Position calibration in the field of underwater acoustic measurement usually uses mechanical positioning devices or underwater rangefinders, which only calibrate the alignment between the sound source and the hydrophone, cannot solve the problem of dynamic calibration of the target object, and does not consider the special needs of the laboratory tank environment.

[0163] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0164] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the same. Although the present invention has been described in detail with reference to preferred embodiments, persons skilled in the art should understand that the specific implementation methods of the present invention may still be modified or some technical features may be replaced by equivalents without departing from the spirit of the technical solutions of the present invention, and all of these should fall within the scope of the technical solutions claimed for protection by the present invention.

Claims

1. A calibration system in a pool environment, characterized in that: include: The interior space of the pool body is defined by a three-dimensional rectangular coordinate system, wherein the three-dimensional rectangular coordinate system has the geometric center of the bottom surface of the pool body as the origin, the length direction parallel to the pool body as the X axis, the width direction parallel to the pool body as the Y axis, and the vertical upward direction as the Z axis; The device to be calibrated is detachably and movably suspended inside the water tank by a suspension device; A position calibration plate is arranged at a preset point, wherein the preset point is based on the projection position of the device to be calibrated on the inner wall of the pool along the X-axis direction or the Y-axis direction when the device to be calibrated is at the desired position; A laser emitter, which is installed above the device to be calibrated and is used to project a laser light spot; A camera device, installed above the device to be calibrated, for capturing an image of the laser spot; A remote controller is communicatively connected to the laser emitter and the camera device, and is used to control the hanging device to drive the device to be calibrated to move to the desired position. During the movement, the camera device captures the laser spot image at the projection point of the laser emitter and sends it to a host computer software; The host computer software is configured to: determine the distance deviation of the device to be calibrated relative to the expected position based on the analysis of the laser light spot image, and send the distance deviation to the remote controller, which performs position correction by controlling the hanging device.

2. The calibration system in a pool environment according to claim 1, characterized in that: The device to be calibrated includes a hydrophone; The hanging device for hanging the hydrophone includes a transverse load rod and a telescopic longitudinal load rod; The transverse load rod is parallel to the Y-axis direction of the water pool body and is mounted on the wall surface of the water pool body in the X-axis direction, and is used to adjust the position of the hydrophone on the X-axis coordinate and the Y-axis coordinate; The hydrophone, laser transmitter and camera equipment are installed at the bottom of the telescopic longitudinal load rod, which are used to adjust the position of the hydrophone on the Z-axis coordinate.

3. The calibration system in a pool environment according to claim 2, characterized in that: The preset points for the location marking plates are specifically: The position marking plate is arranged on either side of the inner wall of the pool in the Y-axis direction, and is arranged at the projection position of the inner wall of the pool along the X-axis direction when the hydrophone is at the desired position.

4. The calibration system in a pool environment according to claim 3, characterized in that: The host computer software is also configured as follows: After the laser transmitter projects a laser spot onto the position marking plate arranged at the projection position of the inner wall of the water pool along the X-axis direction when the hydrophone is at the desired position, an image of the laser spot sent by the remote controller is acquired; The distance deviation of the hydrophone in the water pool in the Y-axis direction and the Z-axis direction is analyzed based on the laser spot image.

5. The calibration system in a pool environment according to any one of claims 1 to 4, characterized in that: The device to be calibrated further includes a sound source and an underwater target object, and the hanging device includes a turntable mechanism for hanging the sound source and / or the underwater target object.

6. The calibration system in a pool environment according to claim 5, characterized in that: The turntable mechanism comprises: A rotating platform, configured as a tabletop that rotates about the Z axis, the rotating platform being equipped with the sound source or the underwater target, a laser transmitter, and a camera device, and being used to drive the sound source or the underwater target to rotate; A planar guide rail, comprising an X-direction slide rail and a Y-direction slide rail, wherein the X-direction slide rail is fixedly installed along the X-axis direction of the pool body, and the Y-direction slide rail is connected to the X-direction slide rail, and the planar guide rail is used to adjust the positions of the sound source and the underwater target in the X-axis coordinate and the Y-axis coordinate; A fixed slide rail in the Z-axis direction, one end of which is fixedly connected to the Y-direction slide rail and the other end is connected to the rotating platform. The fixed slide rail in the Z-axis direction is used to adjust the position of the sound source or the underwater target in the Z-axis coordinate.

7. The calibration system in a pool environment according to claim 6, characterized in that: The preset points of the position marking plate arrangement also include: The position marker is arranged on one side of the inner wall of the pool in the X-axis direction, and is arranged at the projection position of the inner wall of the pool along the Y-axis direction when the sound source or the underwater target is at the desired position; The position marking plate is also arranged at the projection position of the inner wall of the pool body along the X-axis direction when the sound source or the underwater target is at the desired position, wherein the projection position along the X-axis direction of the inner wall of the pool body is respectively located in the Y-axis direction of the inner wall of the pool body close to the sound source or the underwater target.

8. The calibration system for a pool environment according to claim 7, characterized in that: The host computer software is also configured as follows: After the laser transmitter projects a laser spot toward the position marker at the projected position along the Y-axis on the inner wall of the pool body when the sound source or the underwater target is at the desired position, an image of the laser spot sent by the remote controller is acquired; Analyze the distance deviation of the sound source or the underwater target in the water pool in the X-axis direction and the Z-axis direction according to the laser light spot image; After the laser transmitter projects a laser spot toward the position marker at the projected position along the X-axis direction on the inner wall of the pool body when the sound source or the underwater target is at the desired position, an image of the laser spot sent by the remote controller is acquired; The distance deviation of the sound source or the underwater target in the water pool in the X-axis direction and the Z-axis direction is analyzed based on the laser light spot image.

9. The calibration system in a pool environment according to claim 8, characterized in that: The position calibration plate includes a reference point, and the host computer software analyzes the distance deviation to the device to be calibrated in the X-axis direction, Y-axis direction and Z-axis direction respectively based on the position deviation between the laser point position of the laser light spot image and the reference point position.

10. A calibration method in a pool environment, characterized in that: The steps include: Hanging step: detachably and movably hang the device to be calibrated inside the water tank by a hanging device, and arrange the position calibration plate at a preset point based on the projection position of the device to be calibrated on the inner wall of the water tank along the X-axis direction or the Y-axis direction when the device to be calibrated is at a desired position; Image acquisition step: controlling the hanging device through a remote controller to drive the device to be calibrated to the desired position, capturing the laser spot image at the projection point of the laser transmitter installed on the hanging device through a camera installed on the hanging device, and sending the image to the host computer software; Position adjustment step: the host computer software determines the distance deviation of the device to be calibrated relative to the desired position based on the analysis of the laser spot image, and sends the distance deviation to the remote controller, which performs position correction by controlling the hanging device; Target acoustic reflection coefficient calculation step: checking the distance deviation through the position calibration plate, measuring the target acoustic reflection coefficient under the current frequency band, replacing the device to be calibrated on the hanging device with the next device to be calibrated, repeating the image acquisition step and the position adjustment step until the measurement of the target acoustic reflection system of all targets to be measured is completed.

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