CN113532956B - Unmanned aerial vehicle-based water quality sampling method for pump suction type tidal bore tidal head - Google Patents
Unmanned aerial vehicle-based water quality sampling method for pump suction type tidal bore tidal head Download PDFInfo
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Abstract
A pumping tidal bore tide head water quality sampling method based on an unmanned aerial vehicle is characterized in that a tidal bore tide head line identification and propulsion speed analysis module, an unmanned aerial vehicle synchronous tracking tidal bore module and a pumping water quality sampling module are innovatively integrated. Through keeping the relative static flight of unmanned aerial vehicle and tidal bore tide head, reduced the two because of the power destructive action and the influence of speed difference and leading to the water quality sampling action. The hardware of the system comprises a multi-rotor unmanned aerial vehicle flight platform, a flight control module, a ground station module, a holder camera module, a board-mounted computer module and a water quality sampling module. In order to adapt to the severe tidal bore water quality sampling environment, the device adopts a pumping type sampling mode with smaller resistance, and only the water suction pipe probe is placed to different depths of the tidal head, so that the tidal head depth-fixed sampling is realized. The method solves the problem that the traditional sampling mode cannot meet the water quality sampling requirement under the condition of high flow rate, and realizes the water quality sampling under the conditions of high flow rate and severe environment.
Description
Technical Field
The invention relates to the field of intelligent water conservancy, in particular to a water quality sampling method of a pump suction type tidal bore tidal head based on an unmanned aerial vehicle.
The tidal bore of the river mouth of the Qiantang river is known as first line tide, cross tide, head tide and other types, the maximum tidal bore height exceeds 3m, and the Qiantang river mouth has ornamental value. The tidal bore is used as a scarce natural heritage, brings huge tourism benefits in the tidal observation section every year, and powerfully promotes the economic development of the Qiantang river at both sides. The analysis of the change rule of the tidal bore of the estuary of the Qiantang river is beneficial to water resource management and urban development. When the tide comes, can bring a large amount of dissolved oxygen and curl up a large amount of nutrients, the tidal bore can produce very big change to local hydrology and ecological environment, but tidal bore monitoring often concerns about hydrology parameters such as water level, velocity of flow, silt too much, is limited to abominable sampling environment, and the quality of water sampling and the relevant work of monitoring of tidal bore tide head quality of water develop less. Therefore, the research on the safe, reliable and intelligent tidal bore tide head water sample collection method has very important practical significance for developing scientific work such as tidal bore water quality mutation law, local ecological environment and the like.
When the tidal bore arrives, the water level rises by 2-3 m suddenly, the water flow is rapidly converted from a falling tide state to a rising tide state and rapidly reaches an extreme value, the flow rate of the extreme value reaches 6-10 m/s and can reach 12m/s at most, the power is strong, the destructive power is extremely large, and the water quality sampling behavior cannot be implemented. At present, the ecological sampling and monitoring method of tidal heads is not mature enough, and after a period of time elapses and the flow rate becomes slow, relevant personnel use tools such as a water sampler to sample the water quality. Along with scientific and technological development, unmanned, intelligent formation is the research focus, can be applied to each field, and unmanned aerial vehicle flexibility is high, and is strong to adverse circumstances adaptability to have certain load-carrying capacity, use unmanned aerial vehicle to carry out water sampling and help overcoming these difficulties, reduce sampling time and cost, improve sample research reliability.
By consulting relevant documents and patents, no tidal bore tide head water quality sampling device and method aiming at high flow rate are found. In order to realize the water quality sampling of the tidal head by the unmanned aerial vehicle, the moving speed of the tidal head needs to be known, and related patents only provide a tidal head monitoring method based on machine vision (patent application people: university of river and sea, publication No. CN 111914695A), but the tidal head monitoring method based on machine vision is provided in the patent, but the edge position detected in the edge detection by the adopted method has a certain range of errors, so that the accuracy of extracting the tidal head line is influenced, and compared with the edge detection method provided by the patent application, more details can be detected, so that the detection of the edge position is more accurate, and the extraction of the tidal head line is more accurate. Compared with the fixed observation point observation method used in the patent, by means of the tidal bore observation method of unmanned aerial vehicle photogrammetry, morphological change in the tidal bore propagation process can be continuously tracked and observed in a large scale range, and the morphological change process of the river tidal bore of the Qiantangjiang can be better researched. Meanwhile, the method is not used for sampling the water quality of tidal bore tide.
The invention provides a water quality sampling method of a pump suction type tidal bore tidal head based on an unmanned aerial vehicle. The tidal head propulsion speed analysis module, the unmanned aerial vehicle and tidal bore synchronous tracking module and the pump suction type water quality sampling module based on tidal bore image processing are innovatively integrated in the sampling mode. Through keeping the relative static flight of unmanned aerial vehicle and tidal bore tide head, reduced the two because of the power destructive action and the influence of speed difference and leading to the water quality sampling action. In order to adapt to the severe tidal bore water quality sampling environment, a pumping type sampling mode with smaller resistance is adopted, and only the water suction pipe probe is placed to different depths of the tidal head, so that the tidal head depth-fixed sampling is realized. The method solves the problem that the traditional sampling mode cannot meet the water quality sampling under the high flow rate condition, and realizes the water quality sampling under the high flow rate and severe environment conditions.
Disclosure of Invention
The invention aims to solve the problem of water quality sampling under the condition of high flow rate at the present stage, and provides a water quality sampling method of a pump suction type tidal bore tide head based on an unmanned aerial vehicle.
A pumping tidal bore tide head water quality sampling method based on an unmanned aerial vehicle is characterized in that hardware comprises a multi-rotor unmanned aerial vehicle flight platform (1), a flight control module, a ground station module, a cloud deck camera module (3), a board-mounted computer module (12) and a water quality sampling module (2).
Further, the holder camera module (3) transmits the tidal bore photos (videos) shot in real time to the board-mounted computer module (12), and the board-mounted computer module (12) runs a tidal bore tracking algorithm to calculate the current travelling speed of the tidal bore; then the speed is sent to a flight control module, and the unmanned aerial vehicle is controlled to realize synchronous tidal bore tracking after being processed by a flight control algorithm; in the process that the unmanned aerial vehicle and the tidal bore advance synchronously, the sampling manual control end controls the water quality sampling module (2) to realize the pumping type water quality sampling of the tidal head; in the process that the unmanned aerial vehicle and the tidal bore advance synchronously, a photographing instruction is sent to the holder camera module at a fixed distance; the ground station monitors various state data of the unmanned aerial vehicle in the flight process in real time, and is used for guaranteeing flight safety and sending control commands.
A water quality sampling method of a pump suction type tidal bore tidal head based on an unmanned aerial vehicle comprises the following steps:
step 1: firstly, checking and calibrating each module, and confirming that each component and each module are normal;
and 2, step: the unmanned aerial vehicle carries a cloud deck camera (20) to shoot the tidal bore video sequence image;
and step 3: carrying out graying processing and filtering denoising processing on the collected video sequence image;
and 4, step 4: correcting the ashed image, eliminating the influence of factors such as the attitude, the height, the speed and the earth rotation of the unmanned aerial vehicle, and correcting the geometric distortion of the shot tidal bore image;
and 5: detecting the corrected image by using an LOG edge detection algorithm, and detecting a tide line generated by the instant rise of the water level when the tidal bore comes in the image;
step 6: extracting a tide line from the image subjected to edge detection by adopting a circular traversal method;
and 7: calculating the tidal bore advancing speed by analyzing the position change of the front and back frames of tidal head lines;
and 8: the board-mounted computer module runs the algorithm to calculate the current advancing speed of the tidal bore, then the speed is sent to the flight control module, and the unmanned aerial vehicle is controlled to realize tidal head synchronous tracking after the processing of the flight control algorithm;
and step 9: in the process that the unmanned aerial vehicle and the tidal head advance synchronously, the sampling manual control end controls the water quality sampling module, and the pumping type water quality sampling of the tidal head is achieved.
Further, the formula of the step 4 for correcting geometric distortion error of the image is as follows:
let f (x ', y') be the distorted image to be corrected, g (x, y) be the corrected image, and the relationship between the two coordinate systems is h 1 ，h 2 To g forFinding out the corresponding point in f (x ', y') according to the formula, and expressing the value of each point in g (x, y) according to the gray level value of the corresponding point and a certain rule, wherein the specific steps are as follows: let (x) 0 ,y 0 ) For any point in g, the coordinates of the point (α, β) can be found from the above equation for the corresponding point (α, β) in f:
if the point (α, β) is exactly the point on the digitized mesh in f, it is set as point (x' 1 ,y' 1 ) Then point (x' 1 ,y' 1 ) Gray scale value f (x' 1 ,y' 1 ) To represent the midpoint of g (x) 0 ,y 0 ) Grey scale value, i.e. g (x) 0 ,y 0 )＝f(x' 1 ,y' 1 ) However, if (α, β) is not an integer, that is, not a digitized grid point, it is necessary to find a digitized grid point closest to (α, β) and set it to (x' 1 ,y' 1 ) Is then from (x' 1 ,y' 1 ) Expressing (x) in g by dot gray scale value 0 ,y 0 ) Point values, i.e. g (x) 0 ,y 0 )＝f(x' 1 ,y' 1 )。
Further, the method for detecting the LOG edge of the image in step 5 includes:
the first step is as follows: the input image is subjected to one-time Gaussian smoothing processing, the high-frequency signal noise in the image is removed, and the calculation formula is as follows:
g (x, y, sigma) is a symmetric function, a key parameter sigma needs to be set for obtaining a relatively smooth image, after the parameter sigma is set, G (x, y, sigma) and f (x, y) are convoluted, and the relatively smooth image can be obtained after convolution, wherein a convolution expression calculation formula is as follows:
g(x,y)＝f(x,y)*G(x,y,σ)
the second step is that: enhancing the image, wherein the image is enhanced by adopting Laplace operation, and the calculation formula is as follows:
O(x,y)＝▽ 2 (f(x,y)*g(x,y))
the enhanced image G (x, y) is equivalent to G (x, y, σ), which is the associativity of the convolution kernel, so the above equation can be converted into:
O(x,y)＝f(x,y)*▽ 2 g(x,y)
v in formula 2 G (x, y, σ) is the filter of the LOG operator, whose expansion is:
the third step: and detecting the image, namely judging a point of a second derivative O (x, y) =0, namely an intersection point of connecting lines of a zero gray axis and an extreme value of the second derivative, and determining whether the point is the boundary of the image or not by judging whether the first derivative of the point reaches a peak value or not.
Further, the calculation method of the tidal bore advancing speed in the step 7 is as follows: calculating the tidal bore advancing speed through the position change of the extracted front and back frame tide head lines, wherein the relationship between the aerial survey flight height of the unmanned aerial vehicle and the image ground resolution is shown as the following formula:
GSD represents ground resolution, f represents aerial survey camera focal length, H represents flight height, R is static comprehensive resolution, and any point (x) in the tide line is extracted 1 ,y 1 ) As a starting point, after n frames have passed, where the frame rate of the camera is fps and the time of each frame is t, the point proceeds to a point (x) 2 ,y 1 ) Thus, the velocity of this point is:
further, the method for controlling the unmanned aerial vehicle in step 8 is as follows: the board-mounted computer module runs the algorithm to calculate the current travelling speed of the tidal bore, then sends the speed to the flight control module, and controls the unmanned aerial vehicle to realize synchronous tracking of the tidal bore after being processed by the flight control algorithm.
Further, the water quality sampling module: the device comprises a rotary drum (4), a hose (5), a rotary joint (6), a rotary joint fixing support (7), a peristaltic pump (8), a battery (9), a sampling bottle (10), a metal filter screen (11), a single chip microcomputer (13), a direct current motor (14), a direct current motor fixing support (15) and a direct current motor fixing support (16). Unmanned aerial vehicle and the in-process that gos forward in step of gushing out the tide, singlechip (13) control direct current motor (14) start, direct current motor (14) drive rotatory cylinder (4) when rotating and rotate, realize transferring of hose (5) on rotatory cylinder (4), arrive appointed degree of depth after, singlechip (13) control peristaltic pump (8) start, water sampling begins, after sampling bottle (10) reach the requirement capacity, singlechip (13) control peristaltic pump (8) are closed, water sampling finishes, singlechip (13) control direct current motor (14) antiport withdraws hose (5), wherein rotary joint (6) can finely solve hose winding problem. The water quality sampling module can realize the pumping type water quality sampling of the tidal head.
Further, the pan-tilt camera module: three-axis cloud platform and control system based on unmanned aerial vehicle include from steady cloud platform, three-axis cloud platform mechanical structure, three-axis cloud platform control system and three-axis cloud platform algorithm, the cloud platform is stabilized by the unmanned aerial vehicle triaxial is by the complicated system that rotational degree of freedom a (17), rotational degree of freedom b (18), rotational degree of freedom c (19) and move base (21) and constitute, be used for avoiding the change and organism vibrations of unmanned aerial vehicle gesture, disturbance influences such as wind resistance moment, the stability of shooting in keeping unmanned aerial vehicle flight.
Drawings
FIG. 1 shows a water quality sampling method of a pump suction tidal bore tidal head based on an unmanned aerial vehicle. The system comprises an unmanned aerial vehicle flying platform, a water quality sampling module, a tripod head camera module, a 4-rotary drum, a 5-hose, a 6-rotary joint, a 7-rotary joint fixing support, an 8-peristaltic pump, a 9-battery, a 10-sampling bottle, a 11-metal filter screen cover, a 12-board-mounted computer module, a 13-single chip microcomputer, a 14-direct current motor, a 15-direct current motor fixing support, a 16-direct current motor fixing support, a 17-rotational freedom degree a, an 18-rotational freedom degree b, a 19-rotational freedom degree c, a 20-tripod head camera and a 21-movable base.
FIG. 2 is a diagram of a water sampling apparatus.
FIG. 3 is a flow chart of the present invention.
Fig. 4 is a block diagram of the overall system structure of the present invention.
Fig. 5 is a graph showing the gradation and filtering processing.
Fig. 6, geometric distortion error correction map.
FIG. 7, LOG edge detection map.
Fig. 8, tidal head line extraction.
FIG. 9 is a diagram of pixel point locations in a previous frame.
FIG. 10 is a diagram of the pixel location of the next frame.
Detailed Description
The embodiments of the present invention are explained in detail below with reference to the accompanying drawings, and the detailed embodiments and the specific operation procedures are given. The described examples are preferred, but not all, examples of the invention.
In the embodiment, the method is applied by taking the water quality sampling of the tidal bore of qiantangjiang river in the Yanguan section of Hainine as an example, and the specific process is as follows:
the steps are developed according to a flow chart, as shown in fig. 3.
Step 1: a pumping tidal bore tide head water quality sampling method based on an unmanned aerial vehicle is characterized in that hardware comprises a multi-rotor unmanned aerial vehicle flight platform (1), a flight control module, a ground station module, a holder camera module (3), a board-mounted computer module and a water quality sampling module (2), and the modules are firstly checked and calibrated to confirm that components and modules are normal.
And 2, step: the unmanned aerial vehicle carries a holder camera (20) to shoot the tidal bore video sequence images.
And step 3: the collected video sequence image is subjected to graying processing and filtering denoising processing, and the processing result is shown in fig. 5.
And 4, step 4: and (3) correcting the image subjected to ashing processing, eliminating the influence of factors such as the attitude, the height, the speed and the earth rotation of the unmanned aerial vehicle, and correcting the geometric distortion of the shot tidal bore image, wherein the processing result is shown in fig. 6.
And 5: and detecting the corrected image by using an LOG edge detection algorithm, and detecting a tide line generated by the instant rise of the water level when the tide comes in the image.
The first step is as follows: carrying out one-time Gaussian smoothing processing on an input image, removing high-frequency signal noise in the image, and calculating the formula as follows:
g (x, y, sigma) is a symmetric function, a key parameter sigma needs to be set for obtaining a relatively smooth image, the value of sigma in the experiment is 1, G (x, y, sigma) and f (x, y) are convoluted, and a relatively smooth image can be obtained after convolution, wherein the calculation formula of the convolution expression is as follows:
g(x,y)＝f(x,y)*G(x,y,σ)
the second step is that: image enhancement, wherein Laplace operation is adopted for image enhancement, and the calculation formula is as follows:
O(x,y)＝▽ 2 (f(x,y)*g(x,y))
the enhanced image G (x, y) is equivalent to G (x, y, σ), which is the associativity of the convolution kernel, so the above equation can be converted into:
O(x,y)＝f(x,y)*▽ 2 g(x,y)
v in formula 2 G (x, y, σ) is the filter of the LOG operator, whose expansion is:
the third step: image detection, namely, determining a point of the second derivative O (x, y) =0, that is, an intersection of connecting lines of the zero grayscale axis and the extreme value of the second derivative, determining whether the point is a boundary of an image by determining whether the first derivative of the point reaches a peak value, and finally processing the result as shown in fig. 7.
Step 6: the method comprises the steps of extracting a tidal head line from an image after edge detection by adopting a circular traversal method, circularly traversing pixel points in each line, finding a first point with a pixel point of 255, using the first point as a starting point of the tidal head line, sequentially traversing pixel points in each next line, finding a pixel point with a pixel value of 255 and a distance from the previous line within a specified range, and thus finding a continuous point meeting requirements, namely the required tidal head line.
And 7: and calculating the tidal bore advancing speed by analyzing the position change of the front and back frames of tidal head lines.
The relationship between the aerial survey flight height of the unmanned aerial vehicle and the ground resolution of the image is shown as follows:
GSD represents ground resolution, f represents aerial survey camera focal length, H represents flying height, and R is static comprehensive resolution.
Extracting any point (x) in the tide line 1 ,y 1 ) As a starting point, after n frames have passed, where the frame rate of the camera is fps and the time of each frame is t, the point proceeds to a point (x) 2 ,y 1 ) Thus, the velocity of this point is:
in this experiment, the focal length of the camera is 16mm, the flying height is 10m, the static integrated resolution is 72ppi, the video frame rate of the camera is 30fps, the inter-frame time interval is 33.33ms, fig. 9 and fig. 10 show the advancing process diagram of the selected pixel points of the tidal bore of two adjacent frames (i.e. n = 2), wherein (x = 2) is selected 1 ,y 1 )，(x 2 ,y 1 ) Respectively (627, 620) and (665, 627), then it can be calculated:
thus, the instantaneous moving speed of the tide line was calculated to be 4.94m/s.
And step 8: the board-mounted computer module runs the algorithm to calculate the current advancing speed of the tidal bore, then the speed is 4.94m/s and is sent to the flight control module, and the unmanned aerial vehicle is controlled to realize tidal bore synchronous tracking after the processing of the flight control algorithm.
And step 9: unmanned aerial vehicle and the in-process that gos forward in step of gushing out the tide, singlechip (13) control direct current motor (14) start, direct current motor (14) drive rotatory cylinder (4) when rotating and rotate, hose (5) begin to transfer on rotatory cylinder (4), reach behind the appointed degree of depth, direct current motor (14) stall, singlechip (13) control peristaltic pump (8) start, the water sampling begins, sampling bottle (10) reach the requirement capacity after, singlechip (13) control peristaltic pump (8) are closed, the water sampling finishes, singlechip (13) control direct current motor (14) antiport withdraws hose (5), accomplish the depthkeeping water sampling of tide head.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, and any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (6)
1. A water quality sampling method of a pump suction type tidal bore tidal head based on an unmanned aerial vehicle is characterized by comprising the following steps:
step 1, firstly, self-checking and calibrating a flight control module, a ground station module, a holder camera module, a board-mounted computer module and a water quality sampling module, and confirming that the working states of all components and modules are normal;
step 2, carrying a tripod head camera on the unmanned aerial vehicle to shoot a tidal bore video sequence image;
step 3, carrying out graying processing and Gaussian filtering denoising processing on the collected video sequence image to remove river surface ripples and brightness;
step 4, correcting the image subjected to ashing treatment, eliminating the influence of factors such as the attitude, the height, the speed and the earth rotation of the unmanned aerial vehicle, and correcting the geometric distortion of the shot tidal bore image;
step 5, detecting the corrected tidal bore image by adopting an LOG edge detection algorithm, and detecting a tidal head line with large image gray level change caused by the instantaneous rise of the tidal bore water level;
step 6, extracting a tide line from the image subjected to edge detection by adopting a circular traversal method so as to effectively avoid interference generated by river surface random factors;
step 7, calculating the tidal bore propulsion speed by analyzing the position changes of the front and back frames of tidal head lines;
step 8, the onboard computer module runs the algorithm to calculate the current advancing speed of the tidal bore, then the speed is sent to the flight control module, and the unmanned aerial vehicle is controlled to realize synchronous tracking with the tidal head after the processing of the flight control algorithm;
step 9, in the process that the unmanned aerial vehicle keeps synchronous tracking with the tidal head, the water quality sampling module is controlled through the manual control end, and pumping type water quality sampling of the tidal head is achieved;
the LOG edge detection algorithm in the step 5 specifically comprises the following steps:
step 5.1, aiming at the problem of identification of the tidal bore river surface ripple and brightness on the subsequent tide head line, carrying out Gaussian smoothing processing on the input image once to remove the interference of independent and high-brightness noise, wherein the calculation formula is as follows:
wherein, G (x, y, σ) is a symmetric function, in order to obtain a relatively smooth image, a key parameter σ needs to be set, after the parameter σ is set, G (x, y, σ) and f (x, y) are convoluted, after convolution, an image after relative smoothing can be obtained, and a convolution expression calculation formula is as follows:
g(x,y)＝f(x,y)*G(x,y,σ)
step 5.2, when the tidal bore comes, the visual effect of the tidal bore tide head is very obvious relative to the river surfaces before and after the tidal bore tide head, and the gray level change at the joint of the tidal bore tide line and the river surfaces is severe, so that the image is enhanced by adopting Laplace operation, and the calculation formula is as follows:
the enhanced image G (x, y) is equivalent to G (x, y, σ), which is the associativity of the convolution kernel, so the above equation can be converted into:
in the formula
A filter that is a LOG operator whose expansion is:
step 5.3, identifying a point with a second derivative O (x, y) =0, namely a zero crossing point, and judging whether the point is a junction point of a tidal bore head line and a river surface by analyzing whether a first derivative value of the point reaches a peak value;
the calculation method of the tidal bore advancing speed in the step 7 comprises the following steps: calculating the tidal bore advancing speed through the position change of the extracted front and back frame tidal head lines, innovatively mapping the position change of the extracted front and back frame tidal head lines to the size of the ground resolution through image resolution, accurately calculating the actual propagation speed of the tidal bore in real time, and completing the automatic following function of the unmanned aerial vehicle, wherein the relationship between the aerial survey flight height of the unmanned aerial vehicle and the image ground resolution is shown as the following formula:
in the formulaGSD represents ground resolution, f represents aerial survey camera focal length, H represents flight altitude, R represents static comprehensive resolution, and any point (x) in the tide line is extracted 1 ,y 1 ) As a starting point, after n frames have passed, where the frame rate of the camera is fps and the time of each frame is t, the point proceeds to a point (x) 2 ,y 1 ) Thus, the velocity of this point is:
2. the unmanned aerial vehicle-based water quality sampling method for the pump suction tidal bore tidal head, according to claim 1, wherein the formula for correcting the geometric distortion error of the image in the step 4 is as follows:
let f (x ', y') be the distorted image to be corrected, g (x, y) be the corrected image, and the relationship between the two coordinate systems is h 1 ，h 2 For each point in g (x, y), finding out the corresponding point in f (x ', y') according to the above formula, and expressing the value of each point in g (x, y) according to the gray level value of the corresponding point and a certain rule, the specific steps are as follows: let (x) 0 ,y 0 ) For any point in g, the coordinates of the point (α, β) can be found from the above equation for the corresponding point (α, β) in f:
if the point (α, β) is exactly the point on the digitized mesh in f, it is set as point (x' 1 ,y' 1 ) Then the point (x' 1 ,y' 1 ) Gray scale value f (x' 1 ,y' 1 ) To represent the midpoint of g (x) 0 ,y 0 ) Grey scale value, i.e. g (x) 0 ,y 0 )＝f(x' 1 ,y' 1 ) Since (α, β) is not necessarilyInteger numbers, that is, not necessarily digitized grid points, and in this case, it is necessary to find the digitized grid point closest to (α, β) and set it to (x' 1 ,y' 1 ) Is then from (x' 1 ,y' 1 ) Expressing (x) in g by dot gray scale value 0 ,y 0 ) Point value, i.e. g (x) 0 ,y 0 )＝f(x' 1 ,y' 1 )。
3. The unmanned aerial vehicle-based water quality sampling method for the pumping tidal bore tidal head, according to claim 1, is characterized in that the flight control algorithm in step 8 specifically comprises the following steps: the onboard computer module calculates the current travelling speed of the tidal bore, and then sends the speed to the flight control module to control the unmanned aerial vehicle to realize synchronous tracking with the tidal bore.
4. The unmanned aerial vehicle-based water quality sampling method for the pumping tidal bore head, according to claim 1, is characterized in that the holder camera module specifically comprises a self-stabilizing holder, a three-axis holder mechanical structure, a three-axis holder control system and a three-axis holder algorithm, and the three-axis stabilizing holder of the unmanned aerial vehicle is a complex system composed of a rotational degree of freedom a (17), a rotational degree of freedom b (18), a rotational degree of freedom c (19) and a movable base (21), and is used for avoiding the change of the attitude of the unmanned aerial vehicle and the disturbance influences of the body vibration, wind resistance moment and the like, and keeping the shooting stability of the unmanned aerial vehicle in flight.
5. The unmanned aerial vehicle-based pumping tidal bore head water quality sampling method is characterized in that the water quality sampling module comprises a rotary roller (4), a hose (5), a rotary joint (6), a rotary joint fixing support (7), a peristaltic pump (8), a battery (9), a sampling bottle (10), a metal filter screen (11), a single chip microcomputer (13), a direct current motor (14), a direct current motor fixing support (15) and a direct current motor fixing support (16), the single chip microcomputer (13) controls the direct current motor (14) to start in the process that the unmanned aerial vehicle and the tidal bore synchronously advance, the direct current motor (14) is driven to rotate when the direct current motor (14) rotates, the rotary roller (4) is driven to rotate, the hose (5) on the rotary roller (4) starts to be placed down, the direct current motor (14) stops rotating after a specified depth is reached, the single chip microcomputer (13) controls the peristaltic pump (8) to start, water quality sampling starts, the sampling bottle (10) reaches a required capacity, the single chip microcomputer (13) controls the direct current motor (14) to reversely rotate to withdraw the peristaltic pump (8), the water quality sampling module can recover the water quality sampling module, and the tidal bore can well achieve the purpose of winding of the tidal bore of the rotary sampling module.
6. The unmanned aerial vehicle-based pumping tidal bore water quality sampling method according to claim 1, wherein a hardware system for realizing the unmanned aerial vehicle-based pumping tidal bore water quality sampling method comprises a multi-rotor unmanned aerial vehicle flight platform (1), a flight control module, a ground station module, a pan-tilt camera module (3), a board-mounted computer module (12) and a water quality sampling module (2); the flight platform (1) of the multi-rotor unmanned aerial vehicle is used as a carrying platform of other modules, and the ground station module is responsible for monitoring the flight state of the unmanned aerial vehicle; the cloud deck camera module (3) acquires tidal bore tide head images, the on-board computer module (12) carries out image recognition processing on the acquired tidal bore tide images, the advancing speed of the tidal bore tide head is analyzed, the information is transmitted to the flight control module, the unmanned aerial vehicle is controlled by the flight control module to keep flying synchronously with the tidal bore tide, and the water quality sampling module (2) is started while the synchronous flying and relative stillness are kept; compared with the traditional sampling mode of lowering the water sampler, the invention adopts a pumping type sampling mode with smaller resistance, and only lowers the water suction pipe probe to different depths of the tidal head, thereby finally realizing the pumping type water quality sampling of the tidal head at different depths.
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