Calibration system and method in pool environment

Abstract

The invention relates to a calibration system and method in a pool environment, and belongs to the technical field of position calibration. The to-be-calibrated device is detachably and movably hung in the pool body through a hanging device; the preset point position is based on the projection position of the device to be calibrated on the inner wall of the pool body in the X-axis direction or the Y-axis direction when the device to be calibrated is at the expected position; the remote controller is used for controlling the lifting device to drive the to-be-calibrated device to move to an expected position, and in the moving process, laser spot images at the projection position of the laser transmitter are collected through camera equipment and sent to upper computer software; the upper computer software analyzes and judges the distance deviation of the device to be calibrated relative to the expected position based on the laser spot image and sends the distance deviation to the remote controller, and the remote controller carries out position correction by controlling the lifting device. High-precision spatial positioning and dynamic correction of the device to be calibrated are realized, and the calibration precision and efficiency are improved.

Description

Technical Field

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

[0002] Currently, the wet terminal subsystem of a target sound reflection coefficient measurement system usually consists of a sound source, a hydrophone, and an underwater target, and operates in a laboratory pool environment. The sound source emits acoustic wave signals, which are reflected by the underwater target and received by the hydrophone, so as to calculate the acoustic reflection characteristics of the target.

[0003] However, the existing wet terminal subsystem has significant defects in actual measurement. Since the sound source, hydrophone, and target need to be fixed in the pool through a hoisting device, when changing the sound source frequency band or adjusting the orientation of the target, the equipment needs to be repeatedly lifted and re-hoisted, resulting in a shift in the relative positions of the three. The traditional calibration method relies on manual measurement of positions using a scale, which is inefficient and has limited accuracy, especially in a deep-water environment where it is difficult to ensure calibration accuracy. In addition, there is a lack of real-time monitoring means, and position deviations cannot be dynamically corrected, resulting in the inability to effectively compare multiple measurement results, seriously affecting the repeatability of measurement and data reliability.

[0004] Position calibration in the field of underwater acoustic measurement in the prior art usually uses a mechanical positioning device or an underwater rangefinder, which only targets the alignment calibration of the sound source and the hydrophone, cannot solve the problem of dynamic calibration of the target, and does not consider the special requirements of the laboratory pool environment. Summary of the Invention

[0005] Aiming at the deficiencies existing in the related technologies, the purpose of the present invention is to provide a calibration system and method in a pool environment to solve the technical problems that when changing the sound source frequency band or adjusting the orientation of the target in the prior art, the equipment needs to be repeatedly lifted and re-hoisted, resulting in a shift in the relative positions of the three, and position calibration in the field of underwater acoustic measurement usually uses a mechanical positioning device or an underwater rangefinder, which only targets the alignment calibration of the sound source and the hydrophone, cannot solve the problem of dynamic calibration of the target, and does not consider the special requirements of the laboratory pool environment.

[0006] The present invention provides a calibration system in a pool environment, including: A pool body, the internal space of which defines a three-dimensional rectangular coordinate system, with 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 vertically upward direction as the Z-axis; A device to be calibrated, which is detachably and movably suspended inside the pool body through a hoisting device; A position calibration plate, arranged at a preset point, where the preset point is based on the projection position of the device to be calibrated on the inner wall of the pool body in the X-axis direction or Y-axis direction when the device is at the desired position; A laser emitter, installed above the device to be calibrated, for projecting laser light spots; A camera device, installed above the device to be calibrated, for capturing images of the laser light spots; A remote controller, communicatively connected to the laser emitter and the camera device, for controlling the hoisting device to drive the device to be calibrated to move towards the desired position. During the movement, the camera device collects images of the laser light spots projected by the laser emitter and sends them to an upper computer software; The upper computer software is configured to: analyze and judge the distance deviation of the device to be calibrated relative to the desired position based on the laser light spot images, and send the distance deviation to the remote controller, and the remote controller corrects the position by controlling the hoisting device.

[0007] In the embodiments of the present invention, a three-dimensional rectangular coordinate system is established, and the collaborative work of the laser emitter, the camera device and the upper computer software is combined to realize the high-precision spatial positioning and dynamic correction of the device to be calibrated. The light spot projected by the laser emitter 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 upper computer software quantifies the position deviation through image analysis, and then drives the hoisting device to adjust the position of the device to be calibrated. It solves the problem of positioning errors caused by water refraction or mechanical vibration in the pool environment, and improves the calibration accuracy and efficiency.

[0008] In some embodiments of the present invention, the device to be calibrated includes a hydrophone; The hoisting device for hoisting the hydrophone includes a horizontal load rod and a telescopically longitudinal load rod; The horizontal load rod is parallel to the Y-axis direction of the pool body and is mounted on the wall surface of the pool body in the X-axis direction, for adjusting the position of the hydrophone in the X-axis coordinate and Y-axis coordinate; The bottom of the telescopically longitudinal load rod is installed with the hydrophone, the laser emitter and the camera device, for adjusting the position of the hydrophone in the Z-axis coordinate.

[0009] In the embodiments of the present invention, through the combined design of the horizontal load bar and the telescopic vertical load bar, the flexible adjustment of the hydrophone in three-dimensional space is realized. The horizontal load bar is fixed to the pool wall along the Y-axis to ensure the horizontal displacement accuracy in the X-plane and Y-plane, while the telescopic characteristic of the vertical load bar directly regulates the Z-axis depth. The hydrophone, laser emitter, and imaging device integrated at the bottom form an integrated sensing unit. This simplifies the complexity of the hanging device, ensures both the adjustment flexibility and the device stability, enabling the hydrophone to accurately reach the predetermined position and creating conditions for subsequent measurements.

[0010] In some embodiments of the present invention, the preset points where the position calibration plates are arranged are specifically: The position calibration plates are arranged in the Y-axis direction on any side of the inner wall of the pool body, and are arranged at the projection position of the hydrophone on the inner wall of the pool body in the X-axis direction when the hydrophone is at the desired position.

[0011] In the embodiments of the present invention, by accurately arranging the position calibration plates at the projection of the desired position of the hydrophone in the X-axis direction, a detection reference for Y-axis deviation and Z-axis deviation is constructed. When the laser light spot is projected onto the position calibration plate, the position error can be calculated by analyzing only the pixel offsets in the Y-axis direction and Z-axis direction in the image captured by the imaging device, without relying on X-axis data. This simplifies the measurement process and improves the measurement efficiency and accuracy.

[0012] In some embodiments of the present invention, the host computer software is further configured to: After the laser emitter projects a laser light spot onto the position calibration plate arranged at the projection position of the hydrophone on the inner wall of the pool body in the X-axis direction when the hydrophone is at the desired position, obtain the laser light spot image sent by the remote controller; Analyze the distance deviations of the hydrophone in the Y-axis direction and Z-axis direction in the pool body according to the laser light spot image.

[0013] In the embodiments of the present invention, the position deviation of the hydrophone is calculated by extracting the offset of the laser light spot on the position calibration plate. By using the position calibration plate as a static reference system, the dynamic light spot position is converted into a spatial coordinate difference, which is more intuitive and reliable, avoiding the error of manual measurement and realizing fast and accurate position correction.

[0014] 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.

[0015] In the embodiments of the present invention, the compatibility of the device to be calibrated is extended by introducing a turntable mechanism, enabling the system to support the calibration requirements of multiple devices such as sound sources and underwater targets simultaneously. The rotational degree of freedom of the turntable mechanism allows the sound source or underwater target to adjust the azimuth angle around the Z-axis, enhancing the versatility of the system and meeting the calibration requirements of various types of underwater acoustic experiments.

[0016] In some embodiments of the present invention, the turntable mechanism includes: A rotating platform, which is a tabletop set to rotate around the Z-axis. The rotating platform is installed with the sound source or the underwater target, a laser emitter, and a camera device, and is used to drive the sound source or the underwater target to rotate; A planar guide rail, which includes an X-direction slide rail and a Y-direction slide rail. 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. 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 Z-axis direction fixed slide rail, one end of which is fixedly connected to the Y-direction slide rail, and the other end is connected to the rotating platform. The Z-axis direction fixed slide rail is used to adjust the position of the sound source or the underwater target in the Z-axis coordinate.

[0017] In the embodiments of the present invention, through the collaborative design of the planar guide rail, the Z-axis direction fixed slide rail, and the rotating platform, the position control of the sound source or the underwater target is realized. The planar guide rail provides a large-range horizontal movement ability, the Z-axis direction fixed slide rail accurately adjusts the depth, and the rotating platform can rotate around the vertical axis. The independent adjustment in each direction and the mutual cooperation ensure that the device can accurately reach any specified position, providing a guarantee for accurate measurement.

[0018] In some embodiments of the present invention, the preset points where the position calibration plates are arranged further include: The position calibration plate is arranged in the X-axis direction on one side of the inner wall of the pool body, and is arranged at the projection position of the sound source or the underwater target on the inner wall of the pool body in the Y-axis direction when at the desired position; The position calibration plate is also arranged at the projection position of the sound source or the underwater target on the inner wall of the pool body in the X-axis direction when at the desired position, where the projection positions in the X-axis direction on the inner wall of the pool body are respectively located in the Y-axis direction of the inner wall of the pool body close to the sound source or the underwater target.

[0019] In the embodiments of the present invention, when the sound source or the underwater target moves, the laser light spot can be respectively projected onto the position calibration plates in the X-axis direction and the Y-axis direction. By verifying with each other according to the laser light spot graphic data and the measurement results in different directions, the reliability of the position calibration is improved and the measurement error is reduced.

[0020] In some embodiments of the present invention, the host computer software is further configured to: After the laser emitter projects a laser spot onto the position calibration plate at the projection position of the sound source or the underwater target on the inner wall of the pool body in the Y-axis direction when the sound source or the underwater target is at the desired position, obtain the laser spot image sent by the remote controller; Analyze the distance deviations of the sound source or the underwater target in the X-axis direction and the Z-axis direction in the pool body according to the laser spot image; After the laser emitter projects a laser spot onto the position calibration plate at the projection position of the sound source or the underwater target on the inner wall of the pool body in the X-axis direction when the sound source or the underwater target is at the desired position, obtain the laser spot image sent by the remote controller; Analyze the distance deviations of the sound source or the underwater target in the X-axis direction and the Z-axis direction in the pool body according to the laser spot image.

[0021] In the embodiments of the present invention, the laser spot is successively projected onto the position calibration plates in the Y-axis direction and the X-axis direction, the position errors of different planes are respectively calculated, and finally the three-dimensional deviation is obtained through data fusion. It can comprehensively consider the position deviations of the sound source or the underwater target in each direction, give more comprehensive correction suggestions, and avoid the error accumulation caused by single-direction measurement, thereby improving the calibration speed while ensuring the accuracy.

[0022] In some embodiments of the present invention, the position calibration plate includes a reference point, and the host computer software analyzes the distance deviations of the device to be calibrated in the X-axis direction, the Y-axis direction, and the Z-axis direction respectively according to the position deviation between the laser point of the laser spot image and the reference point.

[0023] In the embodiments of the present invention, through the relative position relationship between the reference point on the position calibration plate and the laser spot, the analysis of the intuitive and quantifiable position deviation is realized. The host computer software only needs to calculate the pixel displacement between the laser point and the reference point, and combine the physical size ratio of the position calibration plate to directly convert it into the actual space deviation. The algorithm process is simplified, and at the same time, the operator can directly observe the adjustment effect through the image interface, improving the friendliness of the human-computer interaction.

[0024] Some embodiments of the present invention further provide a calibration method in a pool environment, which is characterized by including the following steps: Hoisting step: Removably and movably hoist the device to be calibrated inside the pool body through a hoisting device, and arrange the position calibration plate at a preset position based on the projection position of the device to be calibrated on the inner wall of the pool body in the X-axis direction or the Y-axis direction when the device to be calibrated is at the 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.

[0025] The embodiment of the present invention uses 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 operation 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

[0026] 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. Figure 1 A front view of a calibration system structure of a device to be calibrated provided in an embodiment of the present invention; Figure 2 A top view of a calibration system structure of a device to be calibrated provided in an embodiment of the present invention; Figure 3 A structural diagram of a hydrophone hanging device provided in an embodiment of the present invention; Figure 4 A front view of a hydrophone calibration system structure provided by an embodiment of the present invention; Figure 5 A top view of a hydrophone calibration system structure provided by an embodiment of the present invention; 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; Figure 7 It is a top view of the calibration system structure of a sound source and an underwater target provided by an embodiment of the present invention; Figure 8 It is a schematic diagram of a position calibration plate provided by an embodiment of the present invention; Figure 9 It is a flowchart of a calibration method in a pool environment provided by an embodiment of the present invention.

[0027] In the figure: 100, pool body; 200, device to be calibrated; 201, hydrophone; 202, sound source; 203, underwater target; 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; 400, laser emitter; 401, first laser emitter; 402, second laser emitter; 403, third laser emitter 500, imaging device; 501, first imaging device; 502, second imaging device; 503, third imaging device; 600, suspension device; 611, transverse load rod; 612, longitudinal load rod; 620, turntable mechanism; 621, first turntable mechanism; 622, second turntable mechanism. Detailed implementation manners

[0028] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be described and explained below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments provided in the present application without making creative efforts belong to the scope of protection of the present application. It should be noted that the terms used herein are only for describing the specific implementation manners and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless otherwise clearly specified in the context, the singular form is also intended to include the plural form. In addition, it should be understood that the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these process, method, product or device. The target acoustic reflection coefficient refers to the ratio of the reflected acoustic energy to the incident acoustic energy when a sound wave encounters a target underwater. It can reflect the characteristic information of the target such as its size, shape, and material. It is an important parameter that must be considered in the stealth design of underwater targets and is also important basic data for sonar to achieve target detection and recognition.

[0029] With the development of new detection technologies and the research and development of new underwater equipment, the signal-to-noise ratio of underwater targets is getting lower and lower, and the requirements for analyzing the acoustic reflection characteristics of underwater targets are getting higher and higher. There is an inevitable need for 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 extremely urgent and is of great significance to fields such as underwater target recognition, precise acoustic guidance, anti-stealth, and ocean development.

[0030] In the field of underwater acoustic measurement, the measurement system for measuring the target acoustic reflection coefficient is divided into two subsystems: the wet terminal subsystem and the dry terminal subsystem. The wet terminal subsystem operates in a laboratory pool environment. Its main functions are to emit sound waves underwater, excite the underwater target to reflect sound waves, and receive the reflected sound waves from the underwater target.

[0031] The wet terminal subsystem consists of a sound source, a hydrophone, and an underwater target, and is suspended at the same depth in the pool by a suspension device. Usually, a stable sound source is used to emit sound to measure the acoustic reflection coefficient of the underwater target, and the hydrophone is used to collect the reflected sound waves of the underwater target. According to the principle of sound wave propagation, in an anechoic pool, the sound energy attenuates as the distance increases. The relative position deviation of the sound source, hydrophone, and underwater target in the pool has a great influence on the measurement result of the underwater target acoustic reflection coefficient.

[0032] In an experimental pool, since it is difficult to fix the positions of the sound source, hydrophone, and target, the change in their relative positions has a great influence on the measurement result, seriously affecting the accuracy and repeatability of the measurement result.

[0033] In addition, to measure the target acoustic reflection coefficient in different frequency bands, the sound source needs to be replaced; to measure different underwater targets, the underwater target needs to be replaced; and to measure the target acoustic reflection coefficient at different positions of the device to be calibrated, the orientation of the device to be calibrated needs to be adjusted. The replacement and adjustment processes involve lifting and re-suspending the sound source and the underwater target, and it is necessary to re-calibrate the positions of the underwater target, sound source, and hydrophone.

[0034] The existing calibration method relies on scale measurement, which is inefficient, has poor accuracy, and lacks effective underwater observation means. It is inevitable to produce distance measurement errors, and there will be position offsets after the sound source and the underwater target are re-suspended, making it impossible to horizontally compare the multiple measurement results of the target acoustic reflection coefficient, and the measurement efficiency is not high.

[0035] In the case of no conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The technical solution of the present invention will be described in detail below in conjunction with specific embodiments and the accompanying drawings of the specification.

[0036] As Figures 1 to 2 shown, the present invention provides a calibration system in a pool environment, including: A pool body 100, the internal space of which defines a three-dimensional rectangular coordinate system. The three-dimensional rectangular coordinate system takes 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 vertically upward direction as the Z-axis; A device to be calibrated 200, which is detachably and movably suspended inside the pool body 100 through a hoisting device 600; A position calibration sign 300, arranged at a preset point. The preset point is based on the projected 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 it is at the desired position; A laser emitter 400, which is installed above the device to be calibrated 200 and is used to project laser light spots; A camera device 500, which is installed above the device to be calibrated 200 and is used to capture images of laser light spots; Optionally, both the camera device 500 and the laser emitter 400 are installed at the bottom of the hoisting device 600 and integrated at the same horizontal plane; A remote controller, communicatively connected to the laser emitter 400 and the camera device 500, is used to control the hoisting device 600 to drive the device to be calibrated 200 to move to the desired position. During the movement, the camera device 500 collects the images of the laser light spots projected by the laser emitter 400 and sends them to an upper computer software; The upper computer software is configured to: analyze and judge the distance deviation of the device to be calibrated 200 relative to the desired position based on the laser light spot images, and send the distance deviation to the remote controller. The remote controller corrects the position by controlling the hoisting device 600.

[0037] Based on the above system, by establishing a three-dimensional rectangular coordinate system and combining the collaborative work of the laser emitter 400, the camera device 500 and the upper computer software, high-precision spatial positioning and dynamic correction of the device to be calibrated 200 are achieved. The light spots projected by the laser emitter 400 and the preset projected positions of the position calibration signs 300 form a spatial mapping relationship. After the camera device 500 captures the light spot images in real time, the upper computer software quantifies the position deviation through image analysis, and then drives the hoisting device 600 to adjust the position of the device to be calibrated 200. It solves the problem of positioning errors caused by water refraction or mechanical vibration in the pool environment, and improves the calibration accuracy and efficiency.

[0038] In some embodiments of the present invention, the device to be calibrated 200 includes a hydrophone 201; The suspension device 600 for suspending the hydrophone 201 includes a lateral load bar 611 and a telescopically longitudinal load bar 612; The lateral load bar 611 is parallel to the Y-axis direction of the pool body 100 and is mounted on the wall surface in the X-axis direction of the pool body 100, and is used to adjust the position of the hydrophone 201 in the X-axis coordinate and the Y-axis coordinate; The bottom of the telescopically longitudinal load bar 612 is installed with a hydrophone 201, a laser transmitter 400 and a camera device 500, and is used to adjust the position of the hydrophone 201 in the Z-axis coordinate.

[0039] Through the combined design of the lateral load bar 611 and the telescopically longitudinal load bar 612, the flexible adjustment of the hydrophone 201 in the three-dimensional space is realized. The lateral load bar 611 is fixed along the Y-axis on the pool wall to ensure the horizontal displacement accuracy in the X-plane and the Y-plane, while the telescopic characteristic of the longitudinal load bar 612 directly controls the Z-axis depth. The hydrophone 201, the laser transmitter 400 and the camera device 500 integrated at the bottom form an integrated sensing unit. The complexity of the suspension device 600 is simplified, which not only ensures the adjustment flexibility but also ensures the device stability, enabling the hydrophone 201 to accurately reach the predetermined position and creating conditions for subsequent measurements.

[0040] In some embodiments of the present invention, the specific preset points where the position calibration plate 300 is arranged are: The position calibration plate 300 is arranged in the Y-axis direction on any one side of the inner wall of the pool body 100, and is arranged at the projection position of the hydrophone 201 on the inner wall of the pool body 100 in the X-axis direction when it is at the desired position.

[0041] By accurately arranging the position calibration plate 300 at the projection of the desired position of the hydrophone 201 in the X-axis direction, a detection reference for the Y-axis deviation and the Z-axis deviation is constructed. When the laser light spot is projected onto the position calibration plate 300, the image captured by the camera device 500 only needs to analyze the pixel offset in the Y-axis direction and the Z-axis direction to calculate the position error, without relying on the X-axis data. The measurement process is simplified, and the measurement efficiency and accuracy are improved.

[0042] In some embodiments of the present invention, the host computer software is further configured to: After the laser transmitter 400 projects a laser light spot onto the position calibration plate 300 arranged at the projection position of the hydrophone 201 on the inner wall of the pool body 100 in the X-axis direction when it is at the desired position, obtain the laser light spot image sent by the remote controller; Analyze the distance deviation of the hydrophone 201 in the Y-axis direction and the Z-axis direction in the pool body 100 according to the laser light spot image.

[0043] By extracting the offset of the laser spot on the position calibration plate 300, the position deviation of the hydrophone 201 is calculated. Using the position calibration plate 300 as a static reference system, the dynamic position of the light spot is converted into a spatial coordinate difference, which is more intuitive and reliable, avoiding the error of manual measurement and achieving fast and accurate position correction.

[0044] Specifically, as Figure 3 shown, the transverse load rod 611 is mounted on the wall surface of the pool body 100 in the X-axis direction, and the bottom of the telescopable longitudinal load rod 612 is provided with a hydrophone 201, a third laser emitter 403 and a third imaging device 503. Among them, the third laser emitter 403 and the third imaging device 503 are integrated on the same horizontal plane and are located above the hydrophone 201.

[0045] As Figures 4 to 5 shown, a second position calibration plate 302 is arranged in the Y-axis direction on one side of the inner wall of the pool body 100, and the second position calibration plate 302 is arranged at the projection position of the hydrophone 201 on the inner wall of the pool body 100 in the X-axis direction when it is in the expected position; A fifth position calibration plate 305 is arranged in the Y-axis direction on the other side of the inner wall of the pool body 100, and the fifth position calibration plate 305 is arranged at the projection position of the hydrophone 201 on the inner wall of the pool body 100 in the X-axis direction when it is in the expected position.

[0046] Turn on the third laser emitter 403, and the third laser emitter 403 projects a laser spot onto the second position calibration plate 302 or the fifth position calibration plate 305. The remote controller collects the laser spot image through the third imaging device 503 and sends it to the host computer software; The host computer software analyzes the distance deviation of the hydrophone 201 in the Y-axis direction and the Z-axis direction in the pool body 100 according to the laser spot image.

[0047] Adjust the position of the transverse load rod 611 in the Y-axis direction and the length of the longitudinal load rod 612 until the distance deviation is within the preset error range.

[0048] Optionally, according to the target sound reflection coefficient measurement algorithm and multiple actual measurement experiences, the error range of the distance deviation is set to 1 centimeter. The multiple measurement results of the target sound reflection coefficient can be compared horizontally to make the measurement error within an acceptable range.

[0049] 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 hoisting device 600 includes a turntable mechanism 620 for hoisting the sound source and / or the underwater target 203.

[0050] By introducing the turntable mechanism 620, the compatibility of the device 200 to be calibrated is extended, enabling the system to support the calibration requirements of various devices such as the sound source 202 and the underwater target 203 simultaneously. The rotational freedom of the turntable mechanism 620 allows the sound source 202 or the underwater target 203 to adjust the azimuth angle around the Z-axis, enhancing the versatility of the system and meeting the calibration requirements of various types of underwater acoustic experiments.

[0051] Among them, the turntable mechanism 620 includes: A rotating platform, which is a tabletop set to rotate around the Z-axis. The rotating platform is installed with the sound source 202 or the underwater target 203, a laser emitter 400, and a camera device 500, and is used to drive the sound source 202 or the underwater target 203 to rotate; A planar guide rail, which includes an X-direction slide rail and a Y-direction slide rail. 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 rail is 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; A Z-axis direction fixed slide rail, one end of which is fixedly connected to the Y-direction slide rail, and the other end is connected to the rotating platform. The Z-axis direction fixed slide rail is used to adjust the position of the sound source 202 or the underwater target 203 in the Z-axis coordinate.

[0052] Through the collaborative design of the planar guide rail, the Z-axis direction fixed slide rail and the rotating platform, the position control of the sound source 202 or the underwater target 203 is realized. The planar guide rail provides a large range of horizontal movement ability, the Z-axis direction fixed slide rail precisely adjusts the depth, and the rotating platform can rotate around the vertical axis. The independent adjustment in each direction cooperates with each other to ensure that the device can accurately reach any specified position, providing a guarantee for accurate measurement.

[0053] In some embodiments of the present invention, the preset points where the position calibration signs 300 are arranged further include: The position calibration signs 300 are arranged in the X-axis direction on one side of the inner wall of the pool body 100, and are arranged at the projection position of the sound source 202 or the underwater target 203 on the inner wall of the pool body 100 in the Y-axis direction when in the desired position; The position calibration signs 300 are 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 in the X-axis direction when in the desired position, wherein the projection positions in the X-axis direction on the inner wall of the pool body 100 are respectively 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.

[0054] When the sound source 202 or the underwater target 203 moves, the laser light spots can be respectively projected onto the position calibration signs 300 in the X-axis direction and the Y-axis direction. By verifying each other according to the laser light spot graphic data and the measurement results in different directions, the reliability of the position calibration is improved and the measurement error is reduced.

[0055] In some embodiments of the present invention, the host computer software is further configured to: After the laser emitter 400 projects a laser light spot onto the position calibration plate 300 at the projection position of the sound source 202 or the underwater target 203 on the inner wall of the pool body 100 in the Y-axis direction when at the desired position, obtain the laser light spot image sent by the remote controller; Analyze 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 according to the laser light spot image; After the laser emitter 400 projects a laser light spot onto the position calibration plate 300 at the projection position of the sound source 202 or the underwater target 203 on the inner wall of the pool body 100 in the X-axis direction when at the desired position, obtain the laser light spot image sent by the remote controller; Analyze 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 according to the laser light spot image.

[0056] By successively projecting the laser light spot onto the position calibration plates 300 in the Y-axis direction and the X-axis direction, respectively calculate the position errors of different planes, and finally obtain the three-dimensional deviation through data fusion. It can comprehensively consider the position deviations of the sound source 202 or the underwater target 203 in various directions, give more comprehensive correction suggestions, and avoid the error accumulation caused by single-direction measurement, thereby improving the calibration speed while ensuring the accuracy.

[0057] Specifically, as Figures 6 to 7 shown, the sound source 202 is hung on the rotating platform of the first turntable mechanism 621 and suspended in the pool body 100.

[0058] The rotating platform of the first turntable mechanism 621 is equipped with a sound source 202, a first laser emitter 401 and a first imaging device 501. Among them, the first laser emitter 401 and the first imaging device 501 are integrated on the same horizontal plane and are located above the sound source 202.

[0059] A first position calibration plate 301 is arranged in the X-axis direction on one side of the inner wall of the pool body 100, and the first position calibration plate 301 is arranged at the projection position of the sound source 202 on the inner wall of the pool body 100 in the Y-axis direction when at the desired position; A third position calibration 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 calibration plate 303 is arranged at the projection position of the sound source 202 on the inner wall of the pool body 100 in the Y-axis direction when at the desired position. Among them, the position of the third position calibration plate 303 is opposite to that of the first position calibration plate 301.

[0060] The second position calibration plate 302 is arranged on one side of the inner wall of the pool body 100 in the Y-axis direction, close to the sound source 202.

[0061] Send a command 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.

[0062] Turn on the first laser emitter 401. The first laser emitter 401 projects laser light spots onto the first position calibration plate 301, the second position calibration plate 302, and the third position calibration plate 303 respectively. The remote controller collects the laser light spot images through the first imaging device 501 and sends them to the host computer software. The host computer software analyzes the distance deviations of the sound source 202 in the X-axis direction and the Z-axis direction in the pool body 100 according to the laser light spot image of the first position calibration plate 301. The host computer software analyzes the distance deviations of the sound source 202 in the Y-axis direction and the Z-axis direction in the pool body 100 according to the laser light spot image of the second position calibration plate 302.

[0063] Adjust the positions of the sound source 202 in the X-axis direction and the Y-axis direction through the planar guide rail of the first turntable mechanism 621, and adjust the telescopic length through the Z-axis direction fixed slide rail of the first turntable mechanism 621 until the distance deviation is within the preset error range.

[0064] The host computer software checks whether the distance deviation is within the preset error range according to the laser light spot image of the third position calibration plate 303.

[0065] Specifically, as shown in the appendix Figures 6 to 7 Hang the underwater target 203 on the rotating platform of the second turntable mechanism 622 and suspend it in the pool body 100.

[0066] The rotating platform of the second turntable mechanism 622 is equipped with an underwater target 203, a second laser emitter 402, and a second imaging device 502. Among them, the second laser emitter 402 and the second imaging device 502 are integrated on the same horizontal plane and are located above the underwater target 203.

[0067] A fourth position calibration plate 304 is arranged in the X-axis direction on one side of the inner wall of the pool body 100, and the fourth position calibration plate 304 is arranged at the projection position of the underwater target 203 on the inner wall of the pool body 100 in the Y-axis direction when the underwater target 203 is in the desired position. A sixth position calibration 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 calibration plate 306 is arranged at the projection position of the sound source 202 on the inner wall of the pool body 100 in the Y-axis direction when the sound source 202 is in the desired position. Among them, the positions of the sixth position calibration plate 306 and the fourth position calibration plate 304 are opposite.

[0068] The fifth position calibration plate 305 is arranged on one side of the inner wall of the pool body 100 in the Y-axis direction, close to the underwater target 203.

[0069] Send an instruction to the second turntable mechanism 622 through the remote controller, and the rotating platform of the second turntable mechanism 622 drives the underwater target 203 to rotate one circle.

[0070] Turn on the second laser emitter 402. The second laser emitter 402 projects laser light spots to the fourth position calibration plate 304, the fifth position calibration plate 305, and the sixth position calibration plate 306 respectively. The remote controller collects the laser light spot images through the second imaging device 502 and sends them to the host computer software; The host computer software analyzes the distance deviations of the sound source 202 in the X-axis direction and the Z-axis direction in the pool body 100 according to the laser light spot image of the fourth position calibration plate 304; The host computer software analyzes the distance deviations of the sound source 202 in the Y-axis direction and the Z-axis direction in the pool body 100 according to the laser light spot image of the fifth position calibration plate 305.

[0071] Adjust the positions of the underwater target 203 in the X-axis direction and the Y-axis direction through the planar guide rail of the second turntable mechanism 622, and adjust the telescopic length through the Z-axis direction fixed slide rail of the second turntable mechanism 622 until the distance deviation is within the preset error range.

[0072] The host computer software checks whether the distance deviation is within the preset error range according to the laser light spot image of the sixth position calibration plate 306.

[0073] In some embodiments of the present invention, as Figure 8 shown, the position calibration plate 300 includes a reference point. The host computer software analyzes the distance deviations of the device to be calibrated 200 in the X-axis direction, the Y-axis direction, and the Z-axis direction respectively according to the position deviation between the laser point of the laser light spot image and the reference point.

[0074] Specifically, as Figure 8 shown, set a plane rectangular coordinate system according to the reference point in the position calibration plate 300 and draw precise scales. Analyze the accurate values of the distance deviations of the device to be calibrated 200 in the three-dimensional direction according to the scale position of the laser point in the laser light spot image on the position calibration plate 300 and the position deviation between the laser point and the reference point.

[0075] 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.

[0076] 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: 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; 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; 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; 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] Replace the next underwater target onto the second turntable mechanism, repeat the image acquisition step S2 and the position adjustment step S3 to recalibrate the position of the underwater target, and continue to repeat the target sound reflection coefficient calculation step S4 to measure the target sound reflection coefficient of the next target to be measured until the measurement of the target sound reflection coefficients of all targets to be measured is completed.

[0081] It should be noted that the sound source and the hydrophone need to be calibrated regularly, and the immersion time in the pool body each time should not exceed 15 days.

[0082] Through the above calibration method, the calibration process is standardized into a four-step cycle of hoisting, image acquisition, position adjustment, and acoustic measurement, forming a reusable operation method. The 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 influence of mechanical errors on the sound reflection coefficient. When replacing different sound sources or underwater targets, the calibration process is automatically repeated to ensure that the data at each frequency point is collected under the same spatial conditions. This improves the experimental efficiency and also reduces the uncertainty introduced by human operation through automation.

[0083] 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.

[0084] The embodiment of the present invention realizes high-precision spatial positioning and dynamic correction of the device to be calibrated. The light spot projected by the laser emitter forms a spatial mapping relationship with the preset projection position of the position calibration plate. After the imaging device captures the light spot image in real time, the host computer software quantifies the position deviation through image analysis, and then drives the hoisting device to adjust the position of the device to be calibrated, solving the technical problem in the prior art that when changing the sound source frequency band or adjusting the azimuth of the target, the device needs to be repeatedly lifted and re-hoisted, resulting in a shift in the relative positions of the three. In the underwater acoustic measurement field, position calibration usually uses a mechanical positioning device or an underwater rangefinder, which only performs a head-on calibration for the sound source and the hydrophone and cannot solve the problem of dynamic calibration of the target, and does not consider the special requirements of the laboratory pool environment.

[0085] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, and the key points of each embodiment are the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other. The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: still can modify the specific implementation manners of the present invention or perform equivalent replacements for some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. A calibration system in a pool environment, characterized in that Comprising: A pool body, the internal space of which defines a three-dimensional rectangular coordinate system. The origin of the three-dimensional rectangular coordinate system is the geometric center of the bottom surface of the pool body. The X-axis is parallel to the length direction of the pool body, the Y-axis is parallel to the width direction of the pool body, and the Z-axis is in the vertically upward direction; A device to be calibrated, which is detachably and movably suspended inside the pool body through a hoisting device; A position calibration sign, arranged at a preset point. The preset point is based on the projection position of the device to be calibrated on the inner wall of the pool body in the X-axis direction or the Y-axis direction when it is in the desired position; A laser emitter, which is installed above the device to be calibrated and is used to project laser light spots; A camera device, which is installed above the device to be calibrated and is used to capture images of the laser light spots; A remote controller, communicatively connected to the laser emitter and the camera device, and is used to control the hoisting device to drive the device to be calibrated to move towards the desired position. During the movement, the camera device collects the images of the laser light spots projected by the laser emitter and sends them to an upper computer software; The upper computer software is configured to: based on the analysis and judgment of the laser light spot images, determine the distance deviation of the device to be calibrated relative to the desired position, and send the distance deviation to the remote controller. The remote controller corrects the position by controlling the hoisting device.

2. The calibration system in the pool environment according to claim 1, characterized in that, The device to be calibrated includes a hydrophone; The hoisting device for hoisting the hydrophone includes a transverse load rod and a telescopically longitudinal load rod; The transverse load rod is parallel to the Y-axis direction of the pool body and is mounted on the wall surface of the pool body in the X-axis direction, and is used to adjust the position of the hydrophone in the X-axis coordinate and the Y-axis coordinate; The bottom of the telescopically longitudinal load rod is installed with the hydrophone, the laser emitter and the camera device, and is used to adjust the position of the hydrophone in the Z-axis coordinate.

3. The calibration system in the pool environment according to claim 2, wherein, The specific preset point where the position calibration sign is arranged is: The position calibration sign is arranged in the Y-axis direction on any side of the inner wall of the pool body, and is arranged at the projection position of the hydrophone on the inner wall of the pool body in the X-axis direction when it is in the desired position.

4. The calibration system in the pool environment according to claim 3, wherein, The upper computer software is further configured to: After the laser emitter projects laser light spots onto the position calibration sign arranged at the projection position of the hydrophone on the inner wall of the pool body in the X-axis direction when it is in the desired position, obtain the laser light spot images sent by the remote controller; Analyze the distance deviations of the hydrophone in the Y-axis direction and the Z-axis direction in the pool body according to the laser light spot images.

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

6. The calibration system in the pool environment according to claim 5, wherein, The turntable mechanism includes: A rotating platform, which is a table surface set to rotate around the Z-axis. The rotating platform is installed with the sound source or the underwater target, the laser emitter and the camera device, and is used to drive the sound source or the underwater target to rotate; A planar guide rail, which includes an X-direction slide rail and a Y-direction slide rail. The X-direction slide rail is fixedly installed along the X-axis direction of the pool body. The Y-direction slide rail is connected to the X-direction slide rail. 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 Z-axis direction fixed slide rail, one end of which is fixedly connected to the Y-direction slide rail, and the other end is connected to the rotary platform. The Z-axis direction fixed slide rail 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, wherein The preset points where the position calibration signs are arranged also include: The position calibration signs are arranged in the X-axis direction on one side of the inner wall of the pool body, and are arranged at the projection position of the sound source or the underwater target on the inner wall of the pool body in the Y-axis direction when in the desired position. The position calibration signs are also arranged at the projection position of the sound source or the underwater target on the inner wall of the pool body in the X-axis direction when in the desired position. Among them, the projection positions in the X-axis direction on the inner wall of the pool body are respectively located in the Y-axis direction of the inner wall of the pool body close to the sound source or the underwater target side.

8. The calibration system in the pool environment according to claim 7, wherein, The host computer software is further configured to: After the laser emitter projects a laser light spot onto the position calibration sign at the projection position of the sound source or the underwater target on the inner wall of the pool body in the Y-axis direction when in the desired position, obtain the laser light spot image sent by the remote controller. Analyze the distance deviations of the sound source or the underwater target in the X-axis direction and the Z-axis direction in the pool body according to the laser light spot image. After the laser emitter projects a laser light spot onto the position calibration sign at the projection position of the sound source or the underwater target on the inner wall of the pool body in the X-axis direction when in the desired position, obtain the laser light spot image sent by the remote controller. Analyze the distance deviations of the sound source or the underwater target in the X-axis direction and the Z-axis direction in the pool body according to the laser light spot image.

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

10. A calibration method in a pool environment, characterized in that, It includes the following steps: Hoisting step: Removably and movably hoist the device to be calibrated inside the pool body through a hoisting device, and arrange the position calibration signs at preset points based on the projection position of the device to be calibrated on the inner wall of the pool body in the X-axis direction or the Y-axis direction when in the desired position. Image acquisition step: Control the hoisting device to drive the device to be calibrated to move towards the desired position through the remote controller, collect the laser light spot image projected by the laser emitter installed on the hoisting device through the imaging device installed on the hoisting device, and send it 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.

Images