An indoor flume sediment transport feature acquisition system and method

Abstract

The application discloses an indoor water tank sediment pushover feature collection system and method, and the system mainly comprises a water tank main body, a buffer unit, a drainage adjusting unit, a sediment feeding device, an imaging unit, an adjustable support and a data processing unit. The method realizes automatic identification, parameter extraction and migration speed calculation of sand wave and other geomorphic forms through non-contact data collection of a high-definition camera and a three-dimensional terrain measuring instrument, does not touch the sediment bed surface in the whole process, eliminates the damage of the traditional contact type measurement to the bed surface form, and ensures the authenticity and reliability of the data. Meanwhile, the buffer design of the slow flow plate combined with the multi-stage water retaining plate effectively dissipates the kinetic energy of the water flow through the hierarchical water outlet structure, greatly reduces the impact force of the injected water flow, avoids the scouring of the bed surface in the initial water injection stage, and effectively protects the stability of the test starting condition.

Description

Technical Field

[0001] This invention relates to the field of sediment detection technology, specifically to an indoor water tank sediment transport characteristic acquisition system and method. Background Technology

[0002] In studies of riverbed evolution and sediment transport, characteristic parameters of riverbed morphology (such as sand waves, sand ripples, and dunes), including wave height, wavelength, steepness, and migration velocity, are crucial research objects. Traditional methods largely rely on manual measurements, which are inefficient, subjective, difficult to monitor continuously, and susceptible to operational errors and instrument precision limitations. While some recent studies have attempted to incorporate image processing techniques, problems remain, such as inaccurate boundary identification, high noise levels, and low automation.

[0003] Traditionally, measurements are taken by directly contacting the bed surface with mechanical probes such as styluses and elevation gauges. While this method is simple and direct, it has significant drawbacks: the probe inevitably disturbs or even destroys the precise sand wave morphology during the measurement process, especially affecting fine-grained mud and sand beds in a critical starting state, leading to data distortion.

[0004] Therefore, there is an urgent need for a method and system for extracting bed surface features that can achieve automated, high-precision, continuous, and non-contact measurement in order to improve the reliability and efficiency of experimental data. Summary of the Invention

[0005] The purpose of this invention is to provide an indoor water tank sediment transport feature acquisition system and method, which enables automatic identification, parameter extraction, and migration velocity calculation of landforms such as sand waves, solving the problems of low efficiency, large errors, and poor continuity of traditional methods. This addresses the issues raised in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for collecting sediment transport characteristics in an indoor water tank, comprising:

[0007] Step 1: Setting up the indoor water tank sediment displacement test. Sand for the model test is laid in a transparent water tank. Flowing water is supplied into the transparent water tank. The water flow rate is adjusted to the target working condition through a water pump and buffer unit. A high-definition camera is set on one side of the transparent water tank and a three-dimensional topographic measuring instrument is set above it. The shooting and measurement positions are adjusted.

[0008] Step 2: Data collection of water flow bed surface. After the water flow has been running for a certain period of time and the sand wave movement has stabilized, the evolution of the bed surface morphology is continuously captured by a high-definition camera. The elevation data of the bed surface inside the transparent water tank is scanned using a three-dimensional topographic surveying instrument. After the water recedes, the morphological parameters are manually measured for verification.

[0009] Step three, data processing, the video taken by the camera is exported as an image sequence at intervals, and semantic segmentation is performed to identify the water-sand interface; the original bed elevation data obtained by the three-dimensional terrain measuring instrument is preprocessed to generate a smooth bed elevation curve, and key morphological parameters are calculated;

[0010] Step four, migration speed calculation, the sand wave migration speed is calculated through time series correlation analysis , construct comprehensive correlation coefficient , take the maximum value corresponding to the displacement , ;

[0011] Step five, precision comparison and error control, the morphological parameter results obtained by analyzing the collected data are compared and verified with the morphological parameter results measured by artificial measurement.

[0012] Preferably, in step two, the video taken by the camera is exported as an image sequence at intervals , the shooting time interval of the high-definition camera is =1min, and the total duration is ≥2h.

[0013] Preferably, in step three, the bed elevation data is filtered and denoised, a dynamic window smoothing method is used, the optimal window length is selected based on the Bayesian information criterion (BIC), and a smooth bed curve is generated.

[0014] Preferably, in step five, the segmentation results are artificially sampled, and are considered valid; the terrain instrument data and the artificial measurement results are cross-compared, and if the difference is >2mm, retesting is required.

[0015] An indoor flume sediment transport feature acquisition system for implementing an indoor flume sediment transport feature acquisition method, comprising:

[0016] A flume body for simulating a water flow environment is made of transparent material, the bottom of which can be paved with test sand, and the two ends are respectively provided with a water pump with adjustable flow and a drainage adjusting unit for controlling the water level in the flume body. The flow parameters can be adjusted according to the test requirements to ensure the stability of the flow field; one side of the flume body is in communication with the output end of the water pump through the water inlet provided thereon, the input end of the water pump is in communication with the water storage tank, and the water storage tank is in communication with the other side of the flume body through the water pipe, so that the flume body, the water pump and the water storage tank form a circulation;

[0017] An imaging unit including a camera, the camera is installed on the side of the flume body and can clearly shoot the bed evolution video;

[0018] A scanning unit including a three-dimensional terrain measuring instrument, the three-dimensional terrain measuring instrument is installed above the flume body and can scan the bed elevation data of the flume body;

[0019] The silt feeding device comprises a silt bin for uniformly feeding test silt into the water tank body.

[0020] The adjustable support is provided with a first track wheel, which is in contact with the first sliding rail at the upper end of the water tank body. The imaging unit, the scanning unit and the silt bin are placed on the adjustable support. The adjustable support can adjust the spatial position of the imaging unit and the scanning unit relative to the water tank body to adapt to different measurement ranges. The adjustable support can adjust the feeding position of the silt bin.

[0021] The data processing unit is connected with the camera and the three-dimensional terrain measuring instrument. The data processing unit is provided with image segmentation, filtering and feature extraction algorithms.

[0022] Preferably, the adjustable support further comprises:

[0023] The adjustable support comprises a sliding frame slidingly arranged on the water tank body, a device mounting portion and a first mounting portion fixed on the sliding frame. The silt bin for feeding silt is fixed on the first mounting portion. The three-dimensional terrain measuring instrument for acquiring three-dimensional terrain data of the silt bed surface is fixed on the device mounting portion. The U-shaped frame on which the camera is slidingly arranged is fixed on one side of the device mounting portion.

[0024] The buffer unit comprises a slow flow plate slidingly arranged on the water inlet side of the water tank body. The slow flow plate is fixed with a plurality of water baffle plates for reducing the impact force of water flow and a water outlet for releasing water flow.

[0025] The drainage adjusting unit comprises a through hole plate fixed on the drainage side of the water tank body. A plurality of through holes for draining water are formed on the through hole plate. A plurality of rotating rods are rotatably installed in the through hole plate. A plurality of flaps for opening and closing corresponding through holes are fixed on the rotating rods. One end of each rotating rod is fixed with a driven gear. Adjacent driven gears are connected through transmission gears to realize synchronous rotation of the flaps and adjust the drainage amount.

[0026] Preferably, the upper end of the water tank body is fixed with first sliding rails on both sides. The sliding frame is provided with a first track wheel. The sliding frame is slidingly installed on the first sliding rails through the first track wheel. The sliding frame is provided with screw holes. The water tank body is provided with a plurality of screw holes. The two screw holes can realize locking of the sliding frame after moving a certain distance.

[0027] The first sliding rail is provided with a flow retarder, the cross section of the flow retarder is arc-shaped, the upper end of the flow retarder is fixedly provided with two sliding plates which are slidably installed on the first sliding rail of the sink body, the sliding plates are provided with screw holes, the upper end of the sink body is provided with screw holes corresponding to the screw holes of the flow retarder, the surface of the flow retarder is fixedly provided with three water baffle plates at equal intervals along the extension direction of the flow retarder, the cross section of the water baffle plate is arc-shaped, one end of the water baffle plate is fixedly connected with the surface of the flow retarder, and the lower end of each water baffle plate is on the same horizontal line with the upper end of the water baffle plate below.

[0028] Preferably, a sediment bin is fixedly arranged on the first mounting portion, a strip-shaped gap is arranged on the surface of the first mounting portion, the sediment outlet of the sediment bin is communicated with the strip-shaped gap, the strip-shaped gap is used for releasing the sediment in the sediment bin, a sliding groove is arranged on the first mounting portion, a first baffle is slidably arranged in the sliding groove, and the first baffle blocks the strip-shaped gap when being in the initial position.

[0029] Preferably, a U-shaped frame is fixedly arranged on the equipment mounting portion, two tracks are fixedly arranged on the inner side of the U-shaped frame, a moving frame is arranged on the tracks, four second track wheels are rotatably arranged on the moving frame, the four second track wheels are divided into two groups and are in contact with the tracks, and a camera is fixedly arranged on the moving frame.

[0030] Compared with the prior art, the device has the following beneficial effects:

[0031] The device realizes non-contact data acquisition through the high-definition camera and the three-dimensional terrain measuring instrument, does not touch the sediment bed surface in the whole process, eliminates the damage to the bed surface form caused by the traditional contact measurement, avoids the interference to the bed surface, and ensures the authenticity and reliability of the data.

[0032] The device constructs an integrated test system, can realize automatic, continuous and non-contact measurement of the bed surface form, significantly improves the data acquisition efficiency, improves the boundary recognition and reduces the noise and parameter extraction accuracy through the combination of image segmentation and dynamic filtering algorithm, introduces the comprehensive correlation coefficient calculation migration speed, avoids the subjectivity of manual interpretation, has a multiple verification mechanism, ensures the data reliability, is suitable for various sediment motion research scenes, has good universality and expansibility, and through the setting of the movable sliding frame, the sediment laying, imaging unit and scanning unit acquisition functions are integrated, the test area can be quickly positioned and switched, the flow retarder reduces the flow impact force, the water inlet and the drainage adjusting unit work cooperatively, the drainage adjusting unit can flexibly adjust the water outlet, so that the water inlet flow can be quickly matched, and the stability of the flow field in the sink can be effectively maintained. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 A flow chart of a method for collecting sediment transport characteristics of an indoor flume according to the present application;

[0034] Figure 2 A camera position diagram of a method for collecting sediment transport characteristics of an indoor flume according to the present application;

[0035] Figure 3 An elevation curve acquisition process diagram of a method for collecting sediment transport characteristics of an indoor flume according to the present application;

[0036] Figure 4 A main structure diagram of a sediment transport characteristics collection system of an indoor flume according to the present application;

[0037] Figure 5 A zoomed-in diagram of A in the figure; Figure 4

[0038] Figure 6 A structure diagram of a sliding frame, a sediment bin and a three-dimensional terrain measuring instrument of a sediment transport characteristics collection system of an indoor flume according to the present application;

[0039] Figure 7 A structure diagram of a U-shaped frame, a track and a camera of a sediment transport characteristics collection system of an indoor flume according to the present application;

[0040] Figure 8 A structure diagram of a through-hole plate of a sediment transport characteristics collection system of an indoor flume according to the present application.

[0041] In the figure: 1, flume main body, 101, water inlet, 102, water pump, 103, water storage tank, 201, slow flow plate, 202, sliding plate, 203, first sliding rail, 204, water baffle, 206, water outlet, 301, sliding frame, 302, first track wheel, 304, equipment mounting part, 305, first mounting part, 307, three-dimensional terrain measuring instrument, 309, U-shaped frame, 310, track, 311, camera, 312, moving frame, 313, second track wheel, 315, contact wheel, 316, second sliding groove, 317, incandescent lamp, 318, mounting plate, 401, sediment bin, 402, strip-shaped notch, 403, first baffle, 601, through-hole plate, 602, through-hole, 603, rotating rod, 604, baffle, 605, water outlet tank, 606, driven gear, 607, transmission gear, 609, rocker, 701, sediment outlet. DETAILED DESCRIPTION

[0042] ​With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of the present application.

[0043] Please refer to Figures 4-8 The present embodiment proposes an indoor flume sediment transport characteristics collection system: the flume main body 1 is in the form of a hollow cuboid as a whole, the flume main body 1 is made of transparent tempered glass, the flow of the sediment in the flume main body 1 can be observed through the transparent glass, the side wall is smooth and transparent, the flume main body 1 is 20 m long, 1 m wide and 0.65 m high, the inner surface bottom is flat for laying the detected sediment, a water inlet 101 is fixedly arranged on one side of the flume main body 1, the water inlet 101 is fixedly connected and communicated with the output end of a water pump 102, the water inlet 101 of the water pump 102 is connected with a water storage tank 103, the water pump 102 is an existing type, and the water pump 102 is arranged to inject the water in the water storage tank 103 into the flume main body 1 through the water inlet 101.

[0044] An electromagnetic flowmeter is fixedly connected to the output end of the water pump 102, the electromagnetic flowmeter is an existing technical component, the water output of the water pump 102 can be counted through the arrangement of the technical component, the water pump 102 is an existing variable frequency water pump capable of adjusting the water output, and the variable frequency water pump can control the water injection amount and the water injection speed into the flume main body 1.

[0045] In the test, in order to realize the position adjustment of the components above the flume main body 1, first sliding rails 203 are fixedly arranged on the upper ends of both sides of the flume main body 1 (shown in Figure 5 A sliding frame 301 is slidingly installed on the first sliding rails 203, four first track wheels 302 (shown in Figure 6 The inner concave surface of the first track wheels 302 is embedded in the first sliding rails 203, the first track wheels 302 can roll along the first sliding rails 203, when the sliding frame 301 moves along the first sliding rails 203, the first track wheels 302 roll along the first sliding rails 203, screw holes are arranged on the sliding frame 301, corresponding screw holes are arranged on the flume main body 1, when the sliding frame 301 moves to the observation position of the high-speed camera 311, the position of the sliding frame 301 can be fixed by screwing bolts into the screw holes of the sliding frame 301 and the flume main body 1.

[0046] The equipment mounting portion 304 is provided on the sliding frame 301, is flat and parallel to the bottom surface of the water tank, one side of the equipment mounting portion 304 is fixed with a mounting plate 318 perpendicular to the equipment mounting portion 304, one mounting plate 318 is fixedly connected with the first mounting portion 305, and the height of the first mounting portion 305 is lower than that of the equipment mounting portion 304.

[0047] To realize the feeding of the sediment into the water tank main body 1, the first mounting portion 305 is fixedly provided with a sediment bin 401 for storing the sediment required for the test, a strip-shaped gap 402 is formed in the first mounting portion 305, and the sediment bin 401 is provided with a sediment outlet communicating with the strip-shaped gap 402, the sediment outlet and the strip-shaped gap 402 are used to release the sediment in the sediment bin 401, a chute is provided on the first mounting portion 305, a first baffle 403 is slidingly installed in the chute, the first baffle 403 can block and close the strip-shaped gap 402 when being in an initial position, the first baffle 403 no longer closes the strip-shaped gap 402 when being pulled away from the strip-shaped gap 402, at this time, the sediment in the sediment bin 401 flows down through the sediment outlet and the strip-shaped gap 402 and can be fed into the water tank main body 1, and the laying thickness of the sediment in the water tank main body 1 needs to be 10 cm-20 cm, after the sediment is fed into the water tank main body 1, the sediment bed surface is leveled by artificial scraping to ensure the flatness of the initial bed surface.

[0048] In the experimental water tank, it is crucial to simulate the natural water flow condition. In the prior art, the water flow of the water inlet directly impacts the bed surface with large kinetic energy, which causes serious scouring to the carefully laid flat bed surface in the initial stage of the experiment, destroys the initial conditions of the test and affects the accuracy and reliability of the data. To slow down the impact force of the water flow pumped by the water pump 102 into the water tank main body 1 on the sediment, a slow flow plate 201 (such as Figure 5 ) is arranged on the side of the water inlet 101 of the water tank main body 1, the slow flow plate 201 is arc-shaped, two sliding plates 202 are fixedly arranged at the upper end of the slow flow plate 201, the two sliding plates 202 are slidingly installed on two first sliding rails 203 of the water tank main body 1, the first sliding rails 203 are two and are fixedly arranged on the two sides of the upper end of the water tank main body 1, when the sliding plate 202 is slidingly arranged on the first sliding rail 203, the slow flow plate 201 can slide relative to the water tank main body 1, when the water pump 102 injects water with different volumes into the water tank main body 1, the injection distance and the landing point of the water are different, so the sliding plate 202 needs to be manually slid along the first sliding rail 203, the sliding plate 202 drives the slow flow plate 201 to move synchronously, and then the position of the slow flow plate 201 is adjusted to adapt to the landing point of the injected water.

[0049] The sliding plate 202 is provided with a threaded hole, and the upper end of the sink body 1 is provided with a threaded hole corresponding to the threaded hole of the sliding plate 202. By screwing a bolt into the threaded holes of the sliding plate 202 and the sink body 1, the position of the sliding plate 202 can be locked, thereby limiting the position of the slow-flow plate 201. The lower end of the slow-flow plate 201 is located above the inner bottom surface of the sink body 1.

[0050] Three water baffle plates 204 are fixedly arranged on the surface of the slow-flow plate 201 at equal intervals along the extension direction of the slow-flow plate 201. The water baffle plates 204 are used to resist the impact of water flow and slow down the impact force of water flow. The water baffle plates 204 are also arc-shaped, with one end of the side surface fixedly connected to the surface of the slow-flow plate 201. The lower end of each water baffle plate 204 is on the same horizontal plane as the upper end of the water baffle plate 204 below it. The three water baffle plates 204 completely cover the arc surface of the slow-flow plate 201. Through the above arrangement, it can be ensured that the water flow first contacts and impacts the water baffle plate 204 when injected into the sink body 1. The surface of the slow-flow plate 201 is provided with three water outlets 206. The installation position of the water outlet 206 corresponds to the installation position of the water baffle plate 204. The water outlet 206 is located on one side of the water baffle plate 204. The lowermost water outlet 206 is located at the bottom of the slow-flow plate 201.

[0051] When the water pump 102 injects water flow into the sink body 1 through the water inlet 101, the water flow first impacts the slow-flow plate 201 and the water baffle plate 204 arranged thereon. Under the blocking and guiding action of the water baffle plate 204, the kinetic energy of the water flow is effectively dissipated, and then falls into the water storage part formed between the slow-flow plate 201 and the side wall of the sink body 1 under the action of gravity. As the water injection continues, the water level in the water storage part gradually rises. When the water level reaches the height of the lowest water outlet 206, the water flow begins to flow smoothly into the interior of the sink body 1 through the water outlet 206. As the water level rises further, the middle and upper water outlets 206 begin to discharge water in turn, and finally realize synchronous overflow of the three water outlets 206. This multi-stage water outlet structure can adapt to the smooth release of the water body in the water storage part under different water injection intensities. Through this buffering process, the kinetic energy of the water flow flowing out of the water outlet 206 has been significantly reduced, and the impact force on the sediment bed surface at the bottom of the sink is greatly weakened compared to the initial jet flow at the water inlet 101, thereby effectively protecting the integrity of the initial bed surface of the test.

[0052] The flow control of the water outlet of the sink body 1 is difficult to quickly and accurately match the dynamic of the water inlet flow, and cannot maintain a stable flow field in the sink under various flow rate conditions, limiting the range and repeatability of the experimental conditions. To realize the regulation and control of the water flow discharged from the sink body 1 and ensure that a stable dynamic balance can be established between it and the water inlet flow, the side opposite to the water inlet 101 of the sink body 1 is fixedly communicated with the water outlet box 605. The side is detachably mounted with a through-hole plate 601 through a bolt.

[0053] The through-hole plate 601 is vertically equidistantly arranged with three rows of through-holes 602, each row having four through-holes 602, a total of twelve through-holes 602, forming four columns of longitudinal channels, each column containing three through-holes 602. Corresponding to the four columns of through-holes 602, four rotating rods 603 are rotatably mounted inside the through-hole plate 601, each rotating rod 603 being arranged along the longitudinal center line of a column of through-holes 602. Each rotating rod 603 is fixedly mounted with three disc-shaped baffles 604, the position of each baffle 604 corresponding to one of the three through-holes 602 in the column, and the rotating rod 603 and the baffle 604 are concentrically fixed. In the initial state, each baffle 604 completely blocks the corresponding through-hole 602, preventing water flow through.

[0054] The upper end of each rotating rod 603 extends out of the through-hole plate 601 and is fixed with a driven gear 606. Each driven gear 606 is in meshing engagement with a transmission gear 607 rotatably arranged on the through-hole plate 601, and adjacent driven gears 606 are linked through a transmission gear 607, thereby forming a gear transmission system that can synchronously rotate the four rotating rods 603 in the same direction.

[0055] A rocker 609 is arranged outside the through-hole plate 601 and is coaxially fixed with the driven gear 606 located at the side. By rotating the rocker 609, the driven gear 606 can be driven to rotate, and then the remaining driven gears 606 can be synchronously rotated through the transmission gears 607, ultimately causing all rotating rods 603 and their baffles 604 to rotate uniformly. When the baffle 604 rotates by a certain angle from the initial fully blocked position, the through-holes 602 in the corresponding column are gradually opened, and water flow can flow into the water tank 605 through the through-holes 602. The maximum rotation angle of the baffle 604 is 90 degrees, at which position the baffle 604 is parallel to the water flow direction, the through-flow area is maximum, and the water discharge reaches the peak value; as the rotation angle of the baffle 604 decreases, the blocked area of the baffle 604 on the through-hole 602 increases, and the water discharge correspondingly decreases. When the water inflow at the water inlet 101 is large, the rotation angle of the baffle 604 is increased to increase the water outflow, and when the water inflow at the water inlet 101 is small, the rotation angle of the baffle 604 is decreased to decrease the water outflow.

[0056] The structure realizes unified control of all drainage channels through the corresponding arrangement of the four rotating rods 603 and the four columns of through-holes 602, in combination with the linkage gear system. The total water outflow can be flexibly adjusted through simple operation of the rocker 609, thereby quickly matching the water inflow and effectively maintaining the stability of the flow field inside the water tank, providing reliable hydraulic conditions for the sediment start-up experiment.

[0057] In order to realize the acquisition of three-dimensional data of sediment, a three-dimensional terrain measuring instrument 307 is fixedly arranged on the equipment mounting portion 304, the scanning end of the three-dimensional terrain measuring instrument 307 is opposite to the upper surface of the sediment in the water tank main body 1, the scanning track of the three-dimensional terrain measuring instrument 307 covers the entire target test section, and the three-dimensional coordinate information of the surface layer of the sediment can be acquired in real time by arranging the three-dimensional terrain measuring instrument 307.

[0058] Further, in order to realize that the camera 311 can continuously record the dynamic evolution process of the bed surface morphology, the observation area of the camera 311 is set to be 0.8 m in the downstream direction and 0.4 m in the vertical direction. The position adjusting mechanism of the camera 311 is designed as follows:

[0059] The equipment mounting portion 304 is fixedly provided with a U-shaped frame 309, the concave direction of the U-shaped frame 309 is opposite to the side surface of the water tank main body 1, the inner side of the U-shaped frame 309 is fixedly provided with two tracks 310, the tracks 310 are provided with a moving frame 312, four second track wheels 313 are rotatably arranged on the moving frame 312, the four second track wheels 313 are divided into two groups and are in contact with the tracks 310, the second track wheels 313 can realize the movement of the moving frame 312 along the extension direction of the tracks 310, and the movement track of the moving frame 312 is ensured to move along the extension direction of the tracks 310 by arranging the second track wheels 313.

[0060] The end of the U-shaped frame 309 away from the equipment mounting portion 304 is rotatably provided with a contact wheel 315, and the contact wheel 315 is in contact with a second sliding groove 316 on the side surface of the water tank main body 1.

[0061] The camera 311 is fixedly arranged on the moving frame 312, the camera 311 is a high-definition camera, and can continuously record the dynamic evolution process of the bed surface morphology in the observation area.

[0062] The lower surface of the equipment mounting portion 304 is fixedly connected with an incandescent lamp 317, the incandescent lamp 317 is used for illuminating the surface layer of the sediment, and provides environmental brightness for data acquisition of the three-dimensional terrain measuring instrument 307 and the camera 311.

[0063] The water tank main body 1 is provided with a sediment outlet 701 on one side, the sediment outlet 701 is located below the through-hole plate 601, and the sediment in the water tank main body 1 can be discharged by opening the sediment outlet 701.

[0064] A water level measuring needle and an acoustic Doppler velocimeter (ADV) are arranged in the water tank, which are respectively used for accurately measuring the water depth and the flow velocity.

[0065] Please refer to Figures 1-3The application provides an indoor flume sediment transport characteristic acquisition method, and the method is realized by the indoor flume sediment transport characteristic acquisition system.

[0066] Step one, indoor flume sediment transport test arrangement: natural sand or light model sand is laid in a transparent flume for model test, flowing water is supplied into the transparent flume, the water flow rate is adjusted to a target working condition through a water pump and a buffer unit, a high-definition camera is arranged on one side of the transparent flume, a three-dimensional terrain measuring instrument is arranged above, and the shooting and measuring positions are adjusted; specifically, first, a sediment layer with a thickness of 10cm-20cm is laid in the flume main body 1. In specific operation, the first baffle 403 is pulled away from the strip-shaped gap 402 so that the strip-shaped gap 402 is no longer closed, and the sediment in the sediment bin 401 falls into the flume main body 1 through the sediment outlet and the strip-shaped gap 402. At this time, the sliding frame 301 is reciprocally moved along the extension direction of the first sliding rail 203 by one stroke through manual pushing, the sliding frame 301 drives the first mounting part 305 and the sediment bin 401 fixed thereon to move synchronously, so that the sediment is uniformly put along the length direction of the flume. After the sediment is laid, the first baffle 403 is pushed in the reverse direction to make it close the strip-shaped gap 402 again, so as to prevent the sediment from continuing to fall, and finally the sediment surface is flattened by the scraper.

[0067] The water flow is adjusted to the target working condition, water injection is performed into the flume main body 1, the water pump 102 is started, when the water pump 102 injects the water flow into the flume main body 1 through the water inlet 101, the water flow first impacts the slow flow plate 201 and the water baffle 204 arranged thereon. Under the blocking and guiding action of the water baffle 204, the kinetic energy of the water flow is effectively dissipated, and then falls into the water storage part formed between the slow flow plate 201 and the side wall of the flume main body 1 under the action of gravity. With the continuous water injection, the water level in the water storage part gradually rises, when the water level reaches the height of the lowest water outlet 206, the water flow starts to flow into the flume main body 1 through the water outlet 206. With the further rising of the water level, the water outlets 206 in the middle and upper parts start to flow water in sequence, and finally realize the synchronous overflow of the three water outlets 206. This multi-stage water outlet structure can adapt to the smooth release of the water body in the water storage part under different water injection intensities. After the buffering process, the water flow flowing out of the water outlet 206 has a significantly reduced kinetic energy, and the impact force on the sediment bed surface of the flume bottom is greatly reduced compared with the initial jet flow of the water inlet 101, thereby effectively protecting the integrity of the initial bed surface.

[0068] While the water injection is being carried out, the slow rotation of the rocker 609 sets the angle of the baffle 604 and the through hole 602. The rocker 609 drives the rotation of the driven gear 606, and through the meshing transmission of the transmission gear 607, the synchronous and same direction rotation of the four driven gears 606 is realized. The driven gear 606 drives the rotation of the rotating rod 603 and the baffle 604 thereon, so that the baffle 604 no longer covers the through hole 602, and the water in the water tank main body 1 flows into the water tank 605 through the through hole 602. Through the water injection of the water pump 102 and the release of the through hole 602, the flow and water depth in the water tank main body 1 gradually reach the preset target working condition. After the water flow is stable (the water surface fluctuation is slight, and the water depth and flow rate measurement values are basically constant), the observation of the bed surface sediment starts to move and gradually forms sand waves.

[0069] Step two, water flow bed surface data acquisition, after the sand wave motion is stable, the high-definition camera continuously shoots the bed surface morphology evolution video, the three-dimensional terrain measuring instrument scans the bed surface elevation data in the transparent water tank, and the morphology parameters are measured manually after the water is drained for verification; specifically:

[0070] After the sand wave motion enters a relatively stable state (the morphology and migration present a periodic law), the moving frame 312 is moved to the side of the water tank main body 1, and the camera 311 is turned on. The camera 311 is set to shoot at an interval of Δt=1min, and the total shooting time is ≥2 hours, and the dynamic evolution process of the bed surface morphology is continuously recorded.

[0071] After the sand wave is stable, the sliding frame 301 is moved, the three-dimensional terrain measuring instrument 307 on the equipment mounting part 304 of the sliding frame 301 is synchronously moved, the three-dimensional terrain measuring instrument 307 is turned on, and the three-dimensional terrain measuring instrument 307 scans the bed surface of the test section to obtain high-precision bed surface elevation point cloud data. In the whole test process, the time sequence data of hydrological parameters such as flow, water level and flow rate are recorded synchronously and automatically or manually.

[0072] After the test is completed, the rocker 609 is reversely rotated, so that the included angle between the baffle 604 and the through hole 602 is reduced. At this time, the water amount released by the through hole 602 is reduced, so that the water in the water tank main body 1 is discharged at a very slow speed to reduce the water level in the water tank main body 1, so as to avoid the backwater scouring and damaging the formed bed surface morphology. After the water is completely drained, the probe, ruler and other tools are used to manually measure the wave height, wavelength and other parameters of at least three typical sand waves in the scanning area of the three-dimensional terrain measuring instrument, and take photos for record, which are used for subsequent verification of the precision of the SAM algorithm.

[0073] Step three, data processing, the video shot by the camera is exported as an image sequence at intervals, and the semantic segmentation is performed to identify the water-sediment boundary; the original bed surface elevation data obtained by the three-dimensional terrain measuring instrument is preprocessed to generate a smooth bed surface elevation curve, and key morphology parameters are calculated; specifically:

[0074] Image segmentation and bed surface line extraction: The video taken by the camera 311 is divided into intervals Exported as an image sequence.

[0075] The sequence images obtained by shooting are imported into a preset Python script, and a pre-trained SAM model (Segment Anything Model) under the PyTorch framework is called to perform semantic segmentation processing on each frame of image. Through this model, the boundary between "water body" and "bed sand" in the image is automatically and accurately identified, thereby determining the position of the bed surface line at each time.

[0076] Elevation data filtering and denoising: For the original bed surface elevation data collected by the three-dimensional terrain measuring instrument, the following preprocessing procedures are performed to eliminate noise interference and retain effective terrain features:

[0077] Dynamic window smoothing method: Set a group of candidate window lengths (such as from 0.05 meters to 0.5 meters, step 0.05 meters), calculate the BIC value corresponding to each window length based on the Bayesian Information Criterion (BIC), and select the window length that minimizes the BIC value as the optimal smoothing window;

[0078] Use algorithms such as Savitzky-Golay filter to smooth the data based on Generate smooth bed surface elevation curve , so as to accurately identify the wave peaks and troughs.

[0079] Automatic extraction of morphological feature parameters: Based on the smoothed elevation curve, identify the wave peaks and troughs, and calculate the key morphological parameters such as wavelength, wave height, steepness, upflow surface angle, and backflow surface angle (upflow surface angle and backflow surface angle are the slope angles ) in the following.

[0080] Reference line determination: Calculate the moving average line of as the global reference line.

[0081] Wave peak and trough identification: Identify the points where the curve intersects the reference line, and find all local maximum points (wave peaks) and local minimum points (troughs).

[0082] Parameter calculation:

[0083] Wavelength ( ): Calculate the horizontal distance between adjacent troughs and take the average.

[0084] Wave height ( ): Calculate the average of the vertical distance between each wave peak and its adjacent two troughs, and then take the average of all wave heights.

[0085] steepness (S): defined as the ratio of wave height to wave length, calculated as . .

[0086] slope angle (SA): calculated as the slope angle of the line connecting the wave crest to the point at a certain proportion of wave height upstream and downstream (e.g. 1 / 6). .

[0087] Step four, migration velocity calculation: calculate the migration velocity of sand waves through time series correlation analysis , construct the comprehensive correlation coefficient , take the maximum value corresponding to the displacement , . The calculation method is as follows:

[0088] Select the continuous two frames of bed elevation data and with a time interval of .

[0089] Within the preset reasonable migration distance search range (e.g. to to ), calculate the comprehensive correlation coefficient of the two sequences in the overlapping interval.

[0090] The displacement amount corresponding to the maximum value is , which is the average migration distance in this time interval.

[0091] Calculate the migration velocity: .

[0092] Step five, precision comparison and error control: compare and verify the morphological parameter results analyzed from the collected data with the morphological parameter results measured manually. Specifically as follows:

[0093] Image segmentation verification: randomly select no less than 3 frames of images, compare the boundaries segmented by SAM automatically with the boundaries marked manually, calculate the average error, and require the error to be less than 2mm.

[0094] Parameter extraction verification: compare the manual measurement value with the automatic extraction value (such as wave height, wave length), calculate the relative error, and require the error to be less than 5%.

[0095] Migration velocity verification: adopt the calculation result of the comprehensive correlation coefficient to ensure the matching reliability.

[0096] Finally, output the test working condition parameters, bed surface morphological parameters, migration velocity data set, and attach the equipment parameters and model scale table.

[0097] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A method for collecting sediment transport characteristics in an indoor water tank, characterized in that, Comprise: Step one, indoor water tank sediment pushover test arrangement, laying model test sand in the transparent water tank, supplying flowing water into the transparent water tank, adjusting the water flow velocity to the target working condition through the water pump and the buffer unit, setting high-definition camera on one side of the transparent water tank and three-dimensional terrain measuring instrument on the top, and adjusting the shooting and measuring positions; Step two, water flow bed surface data acquisition, after the sand wave motion is stable after flowing for a certain time, continuously shooting the bed surface morphology evolution video through the high-definition camera, scanning the bed surface elevation data in the transparent water tank by the three-dimensional terrain measuring instrument, and manually measuring the morphology parameters after water withdrawal for verification; Step three, data processing, the video shot by the camera is exported as image sequence at intervals, and the water body bed sand boundary is identified by semantic segmentation; The original bed surface elevation data obtained by the three-dimensional terrain measuring instrument is pretreated to generate smooth bed surface elevation curve, and the key morphology parameters are calculated; Step four, migration velocity calculation, calculate sand wave migration velocity through time series correlation analysis , build comprehensive correlation coefficient , take the maximum value corresponding displacement , ; Step five, precision comparison and error control, comparing and verifying the morphology parameter results analyzed by the collected data with the morphology parameter results measured manually; In step three, the pre-trained SAM model under PyTorch framework is called for semantic segmentation; the bed surface elevation data is filtered and denoised, the dynamic window smoothing method is adopted, the optimal window length is selected based on the Bayesian information criterion, the Savitzky-Golay filter algorithm is used, and the smooth bed surface elevation curve is generated; based on the smoothed elevation curve, the wave peak and wave trough are identified, and the key morphology parameters including wavelength, wave height, steepness, upflow surface angle and backflow surface angle are calculated; In step four, the migration velocity is calculated as follows: select the time interval as the continuous two frames of bed elevation data and ; In a preset reasonable migration distance search range, a comprehensive correlation coefficient of the two sequences in the overlapping interval is calculated ; the displacement amount corresponding to the maximum value is the average migration distance in the time interval; The migration velocity is calculated as: .

2. The method of claim 1, wherein: In step two, the video taken by the camera is divided into intervals The interval of the high-definition camera is derived as the image sequence = 1 min, total duration ≥ 2 h.

3. A method of collecting fluvial sediment push features from an indoor flume according to claim 2, characterized in that: In step five, the segmentation results are manually sampled, Considered valid; topography data cross compared with manual measurements, differences > 2mm require retesting.

Images