Semi-automatic live fish culture PIV shooting integrated device and method

Abstract

The invention provides a semi-automatic live fish culture PIV shooting integrated device and method, and belongs to the technical field of flow field visualization tests.In a live fish culture system, a filtering device and a heating device are arranged to provide a suitable living environment for shot live fish objects, and in the shooting preparation process, the filtering device and the heating device are arranged in the live fish culture system; the ROS control system is used for controlling the range control device to adjust the position of the calibration plate through a computer, calibration work is completed in the living environment of a shot object, particles are scattered through a hole-shaped structure above the device, and after preparation is completed, calibration is completed. Continuously controlling the range control device through the computer to accurately adjust the limiting plate according to scales on the range adjusting groove so as to control the shooting range, and synchronously controlling the laser and the high-speed camera to complete the shooting process by using the computer. The moving range of live fishes is limited by controlling the limiting plate and the movable top plate, camera calibration and particle scattering work of PIV shooting are completed at the same time, and the PIV shooting process is achieved on the premise that the living environment of a shot object is not changed.

Description

Technical Field

[0001] This invention belongs to the field of flow field visualization testing technology, specifically relating to a semi-automatic integrated device and method for PIV imaging of live fish farming. Background Technology

[0002] Over hundreds of millions of years, fish have evolved highly efficient and maneuverable streamlined bodies, enabling them to flexibly cope with complex underwater environments. Their unique locomotion methods have always been a hot topic in fluid mechanics research, offering significant guidance and application value for the propulsion of underwater vehicles. Therefore, numerous scholars have conducted research in this field using methods such as theoretical analysis, flow visualization, particle image velocimetry (PIV) experiments, and numerical simulations.

[0003] Application number 202010253746.9, entitled "A Method for Automatic Monitoring of the Surface Swimming Status of Fish in Marine Cages by Unmanned Aerial Vehicles," belongs to the field of fish farming. It integrates PIV (Positive Air Volume) technology from fluid tracer measurement into fish movement analysis, using fish as tracer particles in the water surface flow to obtain the swimming trajectory of the farmed fish. Patent publication number CN116222957 A discloses a 3D-printed fish model flow field measurement device and method, relating to the field of hydraulic experimental measurement technology. The fish model is formed using a 3D-printed mold. A PIV data processing computer is used to calculate the surface velocity data and the surrounding flow field distribution data of the fish model based on photographs, realizing the flow field measurement of the fish's stable posture under artificially given inflow conditions.

[0004] Based on the above patent search and in conjunction with the current state of fish farming, the following shortcomings were found in current fish farming tanks:

[0005] First, regarding the patent with application number 202010253746.9, which belongs to the field of fish farming, although it uses the PIV method to capture the movement trajectory of fish, its method treats fish as tracer particles and cannot obtain detailed flow field information when fish are moving.

[0006] Secondly, since the swimming and propulsion mechanisms of live fish are of great significance for underwater biomimetic propulsion research, the device and method of the patent with publication number CN116222957 A are for measuring the flow field of 3D printed fish models rather than live fish, and the device and method cannot obtain the detailed flow field data of live fish.

[0007] In early studies of fish swimming flow field testing, researchers typically fixed the fish to mechanical devices and used external force to drive the fish to form wave-like motion, thus studying the wave propulsion mechanism of fish. The limitation of this method is that it does not consider the mutual influence between the fluids surrounding different segments of the body. With the advent of Particle Image Velocimetry (PIV) technology, biological experiments have gradually evolved from traditional qualitative observations of live fish to more in-depth quantitative measurements of fish motion parameters and flow field characteristics. PIV technology, as a full-field, undisturbed, instantaneous velocity measurement technique, has become an important tool in fluid mechanics research. Using PIV technology to study fish motion morphology and hydrodynamic mechanisms is of great significance to the development of underwater biomimetic propulsion devices, marking a shift in biological experiments from traditional qualitative observations of live fish to more in-depth quantitative measurements of fish motion parameters and flow field characteristics.

[0008] Existing live fish PIV (Picture-in-Video) experimental devices restrict the movement of test subjects by placing them from their original living environment into a fixed filming device. External stimuli are used to induce movement in the test subjects and film this process. Since the test subjects are living animals, they are more sensitive to external stimuli and environmental changes. In traditional experiments, they are prone to fatigue and injury, which increases the experimental time, reduces the controllability of the experiment, and has an adverse effect on the experimental results. Summary of the Invention

[0009] The purpose of this invention is to provide a semi-automatic integrated device and method for live fish farming PIV imaging, which can complete the flow field test of live fish without affecting the living environment of the test subjects.

[0010] The objective of this invention is achieved through the following technical solution:

[0011] A semi-automatic live fish farming PIV (Picture Imager) integrated device includes: a range adjustment system, a live fish farming system, and a shooting system;

[0012] The movable top plate of the range adjustment system is installed in the track groove on the side plate of the live fish farming system via a range limiting block. The range limiting block slides freely longitudinally on the track groove to adjust the upper and lower ranges at different water levels.

[0013] The range adjustment system is equipped with a range control device on the range adjustment slot. The range control device is connected to a calibration plate or a limit plate and is connected to a computer. The computer uses the ROS control system to control the range control device to move the calibration plate back and forth in the range adjustment slot.

[0014] The shooting system includes a laser, a high-speed camera, and a synchronizer installed outside the live fish farming system. The synchronizer is connected to the computer, and the computer controls the laser and the high-speed camera to operate at the same frequency.

[0015] Furthermore, the live fish farming system includes a base plate, which is connected to two support plates, and two side plates are installed between the two support plates.

[0016] Furthermore, the base plate has drainage holes.

[0017] Furthermore, the live fish farming system includes a filtration device and a heating device.

[0018] Furthermore, the range control device is connected to the calibration plate or the limit plate via limit plate connecting bolts and limit plate connectors.

[0019] Furthermore, the range adjustment system includes a movable top plate, which has a lifting handle, a range adjustment groove, a perforated structure, and a range limiting block. The range adjustment groove is marked with a scale and surrounded by the perforated structure. The range control device quantitatively adjusts the position of the calibration plate or the limiting plate according to the scale on the range adjustment groove.

[0020] Furthermore, the power supply lines for the filtration device and the heating device pass through the perforated structure for power supply.

[0021] The present invention may also include:

[0022] A semi-automatic method for integrating PIV (Picture Imager) photography in live fish farming, using the aforementioned device, includes the following steps:

[0023] In the live fish farming system, a suitable living environment is provided for the live fish to be photographed by filtration and heating devices. During the preparation for shooting, the ROS control system is used by computer to control the range control device to adjust the position of the calibration plate and complete the calibration work in the living environment of the subject. Particles are sprinkled through the perforated structure above the device. After preparation, the computer continues to control the range control device to precisely adjust the limit plate according to the scale on the range adjustment groove to control the shooting range. At the same time, the computer synchronously controls the laser and high-speed camera to complete the shooting process.

[0024] Furthermore, the live fish farming system controls the water level by draining water through a drainage hole or by introducing water through a water inlet, and the range adjustment system adjusts the longitudinal shooting range by moving the range limiting block longitudinally on the track groove according to the water level.

[0025] Furthermore, the ROS control system builds a simulation map based on the range adjustment slot, then calls the move_base package and configures the parameters in the ROS control system, sets the coordinate point positions according to different calibration needs, and finally calls the map and control device model respectively.

[0026] The beneficial effects of this invention are as follows:

[0027] This invention completely eliminates the severe stress response caused by transferring fish from their aquaculture environment to specific imaging equipment using traditional methods. The fish remain in their familiar, stable living environment (water temperature, water quality, light), and the observed swimming behaviors (such as cruising, turning, and starting) are natural or quasi-natural. Therefore, the acquired flow field data more accurately reflects the normal physiological activities of the fish, avoiding distortions in movement patterns caused by stress, and greatly improving the reliability and ecological value of the research data.

[0028] This invention improves the success rate and efficiency of PIV (Picture-in-Video) imaging. Through a precisely controlled limit plate via a ROS (Responsive Operating System) mechanism, it guides the fish's movement to a pre-defined imaging area with optimal optical measurement conditions. This avoids repeatedly and blindly waiting for the fish to swim into a specific small area, transforming passive waiting into active guidance. Combined with automated imaging triggering, a large number of effective data samples can be obtained in a single experiment, significantly shortening the experimental cycle and improving research efficiency.

[0029] This invention ensures the repeatability of experiments and animal safety. Because the entire experimental process involves no grasping, physical restraint, or strong stimulation of the fish, they suffer almost no injury or severe physiological stress. This allows for multiple, repeated experimental observations of the same fish, meeting the stringent requirements for experimental repeatability in scientific research.

[0030] This invention uses a computer to control a limit plate and a movable top plate using a ROS (Robot Operating System) to restrict the activity range of live fish, while simultaneously completing camera calibration and particle distribution for PIV (Picture-in-Video) shooting. The shooting range can be flexibly adjusted according to the needs of different subjects, achieving the PIV shooting process without changing the living environment of the subjects. Attached Figure Description

[0031] Appendix Figure 1 This is a schematic diagram of the structure of the present invention;

[0032] Appendix Figure 2 This is a schematic diagram of the installation of the range control device of the present invention;

[0033] Appendix Figure 3 This is a schematic diagram of the range adjustment system of the present invention;

[0034] Appendix Figure 4 This is a schematic diagram of the structure of the base plate of the present invention;

[0035] Appendix Figure 5 This is a schematic diagram of the side plate of the present invention;

[0036] Appendix Figure 6 This is the control flowchart of the ROS control system of the present invention.

[0037] In the attached diagram: 1. Range adjustment system; 101. Lifting handle; 102. Range adjustment groove; 103. Hole structure; 104. Range limiting block; 2. Range control device; 3. Support plate; 4. Calibration plate; 5. Limiting plate; 6. Side plate; 601. Track groove; 7. Base plate; 801. Filter device; 802. Heating device; 9. Laser; 10. High-speed camera; 11. Synchronizer. Detailed Implementation

[0038] The present invention will now be further described with reference to the accompanying drawings.

[0039] Example 1:

[0040] This invention provides a semi-automatic integrated PIV (Picture Imager) device for live fish farming, as shown in the attached document. Figure 1 As shown, it includes: a range adjustment system 1, a live fish farming system, and a shooting system;

[0041] The movable top plate of the range adjustment system 1 is installed in the track groove 601 on the side plate 6 of the live fish breeding system through the range limiting block 104. The range limiting block 104 slides freely in the longitudinal direction on the track groove 601 to adjust the upper and lower ranges at different water levels.

[0042] The range adjustment system 1 has a range control device 2 installed on the range adjustment slot 102. The range control device 2 is connected to the calibration plate 4 or the limit plate 5. The range control device 2 is connected to the computer 12. The computer 12 uses the ROS control system to control the range control device 2 to drive the calibration plate 4 to move back and forth in the range adjustment slot 102.

[0043] The shooting system includes a laser 9, a high-speed camera 10, and a synchronizer 11 installed outside the live fish farming system. The synchronizer 11 is connected to the computer 12, and the computer 12 controls the laser 9 and the high-speed camera 10 to work at the same frequency.

[0044] The live fish farming system includes a base plate 7, which is connected to two support plates 3. Two side plates 6 are installed between the two support plates 3, as shown in the attached figure. Figure 5 As shown.

[0045] The live fish farming system includes a filtration device 801 and a heating device 802.

[0046] As attached Figure 4 As shown, the base plate 7 has drainage holes 701.

[0047] As attached Figure 2 As shown, the range control device 2 is connected to the calibration plate 4 or the limit plate 5 via the limit plate connecting bolt 201 and the limit plate connecting piece 202.

[0048] As attached Figure 3 As shown, the range adjustment system 1 includes a movable top plate, which has a lifting handle 101, a range adjustment groove 102, a perforated structure 103, and a range limiting block 104. The range adjustment groove 102 is marked with a scale and surrounded by the perforated structure 103. The range control device 2 quantitatively adjusts the position of the calibration plate 4 or the limiting plate 5 according to the scale on the range adjustment groove 102.

[0049] In this embodiment, the power supply lines of the filter device 801 and the heating device 802 pass through the perforated structure 103 to connect and supply power.

[0050] This embodiment provides a semi-automatic PIV (Picture-in-Video) imaging method for live fish farming using the above-mentioned device, including the following steps:

[0051] In the live fish farming system, a suitable living environment is provided for the live fish to be photographed by arranging a filter device 801 and a heating device 802. During the preparation for shooting, the ROS control system of the computer 12 controls the range control device 2 to adjust the position of the calibration plate 4 and completes the calibration work in the living environment of the subject. Particles are sprinkled through the perforated structure 103 above the device. After preparation, the computer 12 continues to control the range control device 2 to precisely adjust the limit plate 5 according to the scale on the range adjustment groove 102 to control the shooting range. At the same time, the computer 12 synchronously controls the laser 9 and the high-speed camera 10 to complete the shooting process.

[0052] Specifically, the process includes the following steps: assembling all components; setting test conditions according to different test requirements; controlling the water level by draining or filling the drain hole 701; adjusting the longitudinal shooting range by moving the range limiting block 104 longitudinally on the track groove 601 according to the water level; connecting the range control device 2 and the calibration plate 401; using ROS control via computer 12 to move the calibration plate 401 back and forth in the range adjustment groove 102; and using a synchronizer 11 connected to computer 12 to control the high-speed camera 10 to photograph the calibration plate 401. 1. Thus, calibration information is obtained, calibration work is completed, calibration plate 401 is disassembled, tracer particles are scattered through perforated structure 103, range controller 2 and limit plate 5 are connected, and the ROS control device 2 is used by computer 12 to drive the limit plate 5 to move back and forth in the range adjustment groove 102 to limit the depth range of the object being photographed. The computer 12 is connected to synchronizer 11 to control high-speed camera 10 and laser 9 to work synchronously. When the object being photographed enters the shooting range, its movement is photographed. The experimental device is reset, and the fluid in the device is replaced through drainage hole 701 to complete the experiment.

[0053] In this embodiment, the ROS control system builds a simulation map based on the range adjustment slot, then calls the move_base package and configures the parameters in the ROS control system, sets the coordinate point positions according to different calibration needs, and finally calls the map and control device models respectively.

[0054] Example 2:

[0055] According to the semi-automatic live fish farming PIV imaging integrated device described in Example 1, the method for performing semi-automatic live fish farming PIV imaging in this embodiment includes:

[0056] (1) System initialization and establishment of live fish environment:

[0057] Device assembly: as shown in the attached document Figure 1 As shown, place the water tank (live fish farming system) on a stable platform. Install the side panel 6, ensuring the track groove 601 on it is vertical. Install the movable top plate with the range adjustment groove 102 and the perforated structure 103 into place.

[0058] Water Injection and Environmental Control: Clean water is injected into the water tank through the drain hole 701. The filter device 801 and the heating device 802 are activated, with their power lines connected through the perforated structure 103 on the top plate. The water temperature and quality are adjusted and stabilized within the optimal survival range for the target fish species (such as zebrafish and koi fry), providing a long-term stable and low-stress living environment for the subjects being filmed.

[0059] (2) Integrated semi-automatic calibration

[0060] Install the calibration plate: Connect the calibration plate 4 to the range control device 2 via the limit plate connecting bolt 201 and the connector 202. This control device can be driven by a stepper motor or a linear module and is connected to the computer 12 running the ROS system via a data cable.

[0061] ROS control calibration: On the computer, the ROS environment calls function packages such as move_base to send commands to control the range control device 2, driving the calibration plate 4 to move precisely along the range adjustment groove 102 to the preset position in the water tank.

[0062] Image acquisition: Under computer control, the high-speed camera 10 captures images of the calibration plate at different locations to complete camera calibration.

[0063] (3) Particle dispensing and shooting range preset

[0064] Distributing tracer particles: After calibration, remove the calibration plate. Using a dedicated syringe or particle distributor, evenly distribute tracer particles (such as hollow glass microspheres) of an appropriate concentration into the water body through the perforated structure 103 on the top plate.

[0065] Preset shooting area: The ROS system controls the range control device 2 to move the limiting plate 5. A narrow "shooting corridor" can be precisely set according to the top plate scale 102 and research needs. The range limiting block 104 adjusts its depth along the side plate track groove 601, thereby defining a non-closed but effective guiding area in three-dimensional space.

[0066] (4) Non-invasive PIV imaging:

[0067] System ready: Laser 9 and high-speed camera 10 are synchronized with the computer via synchronizer 11. After all equipment is in place, allow the fish to stand still for a period of time to adapt to the presence of the limiting plate.

[0068] Triggered Shooting: When the target live fish spontaneously swims into the preset "shooting corridor," the PIV shooting system is manually triggered by a computer or automatically triggered by a set area sensor. Laser light illuminates the flow field, and a high-speed camera continuously captures two or more frames of images with tracer particles.

[0069] Data acquisition: The computing software processes the image sequence through a cross-correlation algorithm to obtain refined flow field data such as the instantaneous velocity vector field and vorticity field of the flow field around the fish when it swims.

[0070] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A semi-automatic live fish farming PIV (Picture-in-Video) integrated device, characterized in that, include: Range adjustment system (1), live fish farming system, and shooting system; The movable top plate of the range adjustment system (1) is installed in the track groove (601) on the side plate (6) of the live fish breeding system through the range limiting block (104). The range limiting block (104) slides freely in the longitudinal direction on the track groove (601) to adjust the upper and lower ranges at different water levels. The range adjustment system (1) has a range control device (2) installed on the range adjustment slot (102). The range control device (2) is connected to the calibration plate (4) or the limit plate (5). The range control device (2) is connected to the computer (12). The computer (12) uses the ROS control system to control the range control device (2) to drive the calibration plate (4) to move back and forth in the range adjustment slot (102). The shooting system includes a laser (9), a high-speed camera (10) and a synchronizer (11) installed outside the live fish farming system. The synchronizer (11) is connected to the computer (12), and the computer (12) controls the laser (9) and the high-speed camera (10) to work at the same frequency.

2. The semi-automatic live fish farming PIV imaging integrated device according to claim 1, characterized in that, The live fish farming system includes a base plate (7), which is connected to two support plates (3), and two side plates (6) are installed between the two support plates (3).

3. The semi-automatic live fish farming PIV imaging integrated device according to claim 2, characterized in that, The base plate (7) has drainage holes (701).

4. The semi-automatic live fish farming PIV imaging integrated device according to claim 3, characterized in that, The live fish farming system includes a filtration device (801) and a heating device (802).

5. The semi-automatic live fish farming PIV imaging integrated device according to claim 4, characterized in that, The range control device (2) is connected to the calibration plate (4) or the limit plate (5) via the limit plate connecting bolt (201) and the limit plate connector (202).

6. The semi-automatic live fish farming PIV imaging integrated device according to claim 5, characterized in that, The range adjustment system (1) includes a movable top plate, which has a lifting handle (101), a range adjustment groove (102), a perforated structure (103), and a range limiting block (104). The range adjustment groove (102) is marked with a scale and surrounded by the perforated structure (103). The range control device (2) quantitatively adjusts the position of the calibration plate (4) or the limiting plate (5) according to the scale on the range adjustment groove (102).

7. The semi-automatic live fish farming PIV imaging integrated device according to claim 6, characterized in that, The power supply lines of the filter device (801) and the heating device (802) pass through the perforated structure (103) and are connected for power supply.

8. A semi-automatic live fish farming PIV (Picture-in-Video) integrated method, characterized in that, The apparatus according to any one of claims 1-7 comprises the following steps: In the live fish farming system, a suitable living environment is provided for the live fish to be photographed by arranging a filter device (801) and a heating device (802). During the preparation for shooting, the ROS control system of the computer (12) controls the range control device (2) to adjust the position of the calibration plate (4) and complete the calibration work in the living environment of the subject. Particles are sprinkled through the perforated structure (103) above the device. After the preparation is completed, the computer (12) continues to control the range control device (2) to precisely adjust the limit plate (5) according to the scale on the range adjustment groove (102) to control the shooting range. At the same time, the computer (12) synchronously controls the laser (9) and the high-speed camera (10) to complete the shooting process.

9. The semi-automatic live fish farming PIV shooting integrated method according to claim 8, characterized in that, The live fish farming system controls the water level by draining or filling water through the drain hole (701). The range adjustment system (1) adjusts the longitudinal shooting range by moving the range limiting block (104) longitudinally on the track groove (601) according to the water level.

10. The semi-automatic live fish farming PIV shooting integrated method according to claim 9, characterized in that, The ROS control system builds a simulation map based on the range adjustment slot, then calls the move_base package and configures the parameters in the ROS control system, sets the coordinate point positions according to different calibration needs, and finally calls the map and control device models respectively.

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