LU500577B1

LU500577B1 - Acoustic Doppler Current Profiler Calibration Device and Method Based on Unmanned Ship

Info

Publication number: LU500577B1
Application number: LU500577A
Authority: LU
Inventors: Huaqing Zhang; Yicheng Liu; Yufen Cao; Yunyue Chen; Shaohui Li; Chunhui Dou; Mingmin Zhang; Xu Zhang; Song Ye; Hongsheng Han
Original assignee: Tianjin Research Inst Water Transp Engineering Mot; Univ Tianjin; National Univ Of Defense Technology
Priority date: 2021-08-25
Filing date: 2021-08-25
Publication date: 2022-02-25

Abstract

An acoustic Doppler current profiler calibration device and method based on an unmanned ship. An adapter bracket of the device is fixed on the unmanned ship, the upper part of the adapter bracket is connected with a GPS measuring instrument, the lower part of the adapter bracket is connected with a precise angle turntable, the precise angle turntable is connected with a to-be-detected acoustic Doppler current profiler through an adapter flange plate, and a connecting line of two high-speed cameras is parallel to the long side of a test pool and is far away from the test pool. The device has the beneficial effects that the unmanned ship drives an Acoustic Doppler Current Profiler (ADCP) to sail back and forth along a track line to measure channel flow velocity, the high-speed cameras and total station equipment with a traceable magnitude measure average velocity of the ADCP in a measurement section.

Description

DESCRIPTION LUS00577 Acoustic Doppler Current Profiler Calibration Device and Method Based on Unmanned Ship

TECHNICAL FIELD The present invention belongs to the technical field of hydrological measurement instrument metering, and particularly relates to an acoustic Doppler current profiler calibration device and method based on an unmanned ship in the field of water transport engineering.

BACKGROUND An acoustic Doppler current measurement technique is a major breakthrough in a current measurement technique in the 1980s. An Acoustic Doppler Current Profiler (ADCP) is a new instrument that uses this principle to observe ocean current. Compared with a flow sensor based on mechanical power, the ADCP does not need to start a flow rate, and can quickly measure three-dimensional flow velocity in a large range with high precision on the premise of not disturbing flow fields. At present, it is widely used in water transport engineering construction, hydrological environment monitoring, ocean and estuary flow field structure investigation, port and channel flow velocity and flow test, etc., with measurement results and related techniques approved by relevant workers. However, long-term changes in the operating environment will cause changes in the performance of the instrument itself, resulting in large deviations in the measurement results of the instrument. Therefore, it is particularly important to calibrate/test the flow rate and flow direction metering performance of the instrument regularly.

At present, there is no large-scale calibration test device for the ADCP. The calibration of the ADCP is mainly divided into indoor flow velocity pool calibration and outdoor navigation calibration. Due to the expansion of the frequency range of LUS00577 ADCP and the inspection requirements of the stratified flow velocity, the indoor calibration of the ADCP has higher requirements for a linear static pool: the length of the pool being not smaller than 100 m, the width of the pool being not smaller than 3 m, the depth of the pool being not smaller than 3 m, a flow velocity trailer system with a speed not less than 5m/s needing to be equipped, and a water body needing to contain suspended particles or gas bubbles and the like. The above many restrictions bring huge expenses and construction cost to the indoor ADCP calibration test. Outdoor navigation calibration is generally carried out in natural environments such as oceans, rivers or lakes by means of self-calibration or comparison. Due to the influences of the comprehensive environment such as waves, tides, current and sand in the field, large uncertainty is introduced into the calibration.

SUMMARY To solve the problems, the present invention provides an acoustic Doppler current profiler calibration device and method based on an unmanned ship, where calibration parameters include flow velocity and a flow direction. Through a ship gate channel that can be opened/closed at an outdoor entrance to the sea, the unmanned ship drives an Acoustic Doppler Current Profiler (ADCP) to sail back and forth along a center line of the short side of a pool to measure channel flow velocity, high-speed cameras and total station equipment with a traceable magnitude (electronic total station) measure average velocity of the ADCP in a measurement section, the average velocity serves as a reference standard value to be compared with a flow velocity indication value of the ADCP, and flow velocity parameter calibration is conducted; through a precise angle turntable with a traceable processing magnitude, an included angle between an indication direction of the ADCP and a navigation direction is adjusted, a movement track and yaw errors of the unmanned ship are plotted, a flow LUS00577 direction reference standard value is calculated and compared with a flow direction indication value of the ADCP, and flow direction parameter calibration 1s carried out.

According to the technical scheme adopted by the present invention, an acoustic Doppler current profiler calibration device based on an unmanned ship includes a test pool, the unmanned ship, an adapter bracket, a GPS measurement instrument, a first high-speed camera, a second high-speed camera, a total station instrument and a precise angle turntable, where the adapter bracket is fixedly arranged on the unmanned ship; the upper part of the adapter bracket is connected with the GPS measurement instrument; the precise angle turntable is connected with a to-be- detected acoustic Doppler current profiler through an adapter flange plate, and a connecting line of optical centers of the first high-speed camera and the second high- speed camera is parallel to the long side of a test pool and is far away from the test pool; the total station instrument is positioned at one side, away from the test pool, of the connecting line of optical centers of the first high-speed camera and the second high-speed camera. Further, axes of the optical centers of the first high-speed camera and the second high-speed camera are perpendicular to the long side of the test pool, and the total station instrument is positioned on a perpendicular bisector of the first high-speed camera and the second high-speed camera.

Further, axes of the GPS measurement instrument, the precise angle turntable, the adapter flange plate and the to-be-detected acoustic Doppler current profiler are superposed.

Preferably, the dimension of the unmanned ship is that length 1.5 m x width 0.4 m x height 0.3 m, and the highest operation speed of the unmanned ship is 5 m/s.

Further, the test pool is divided into an acceleration section, a measurement LU500577 section and a deceleration section according to an operation state of the unmanned ship; the length of the acceleration section is not smaller than a distance that the unmanned ship travels while accelerating to the highest speed from a static state; the length of the deceleration section is not smaller than a distance that the unmanned ship travels while decelerating to the static state from the highest speed; the measurement section serves as a detection area for flow velocity parameter calibration of the to-be-detected acoustic Doppler current profiler, and the length of the measurement section is not smaller than a distance that the unmanned ship uniformly travels for 30 s with the highest operation speed.

The test pool is a regular semi-sealed rectangular ship gate with a length of 180 m, a width of 25 m and a depth of 10 m; and the test pool is a stable test site with suspended matters and stratified flow fields.

Further, a connecting line of midpoints of two short-side walls of the test pool is taken as a track line that the unmanned ship travels, and the track line is parallel to the long side walls of the test pool.

Further, the first high-speed camera and the second high-speed camera are of the same-model high-speed camera, a frame rate of the first high-speed camera and the second high-speed camera is 30 fps or more; a trigger line for allowing the unmanned ship to travel in and out is arranged in each field range of the first high-speed camera and the second high-speed camera, the travel-in trigger line within the field range of the first high-speed camera is superposed with a selected boundary line entering the measurement section of the unmanned ship in the test pool, the travel-out trigger line within the field range of the second high-speed camera is superposed with the selected boundary line leaving the measurement section of the unmanned ship in the test pool;

and the sizes of the view fields of the first high-speed camera and the second high- LUS00577 speed camera should guarantee that the unmanned ship can uniformly operate for 30 s for more with the highest operation speed in the trigger area of each high-speed camera.

An acoustic Doppler current profiler calibration method based on an unmanned ship includes a flow velocity calibration method and a flow direction calibration method. The flow velocity calibration method is as follows: the unmanned ship drives a to-be-detected Acoustic Doppler Current Profiler (ADCP) to sail back and forth along a center line, namely a track line, of the short side of a pool to measure channel flow velocity, a first high-speed camera, a second high-speed camera and total station equipment with a traceable magnitude measure average velocity of the ADCP in a measurement section, the average velocity serves as a reference standard value to be compared with a flow velocity indication value of the ADCP, and flow velocity parameter calibration is conducted.

The flow direction calibration method is as follows: through the precise angle turntable with the traceable processing magnitude, an included angle between an indication direction of the ADCP and a navigation direction 1s adjusted, a movement track and yaw errors of the unmanned ship are plotted, a flow direction reference standard value is calculated and compared with a flow direction indication value of the ADCP, and flow direction parameter calibration is carried out.

Further, the flow velocity calibration method specifically includes the following steps: step 1, mounting the to-be-detected ADCP to the bottom of the unmanned ship through the adapter flange plate, adjusting a zero-indication sign of the to-be-detected ADCP to be superposed with that of the precise angle turntable, accessing a communication cable connected with a transducer of the to-be-detected ADCP into an LUS00577 electronic watertight compartment of the unmanned ship, and stably hoisting the unmanned ship to the test pool; step 2, normally starting the unmanned ship, the to-be-detected ADCP, the first high-speed camera and the second high-speed camera, and establishing time synchronizing datum among the unmanned ship, the transducer of the to-be-detected ADCP, the first high-speed camera and the second high-speed camera based on second pulse of the GPS measurement instrument; step 3, sampling two parallel virtual straight lines which are equal in length of 180 m by the total station instrument, where one straight line is parallel to the long sides of the test pool and passes through midpoints of the short sides of the test pool to serve as a set track line that the unmanned ship travels, and the other straight line is positioned at one side of the first high-speed camera and one side of the second high- speed camera to serve as a metering standard line.

step 4, dividing the long sides of the test pool into an acceleration section, a measurement section and a deceleration section according to the length of the test pool and the highest traveling speed of the unmanned ship, determining the metering standard line sampled by the total station instrument for absolute coordinates of partition points of each section, recording absolute coordinate values of a start point and an end point of the measurement section on a set track line corresponding to the metering standard line, and inputting the absolute coordinate values into control software of a platform system of the unmanned ship for route instruction edition; step 5, separately mounting the first high-speed camera and the second high- speed camera on a start position and an end position of the measurement section, where axes of optical centers of the first high-speed camera and the second high-

speed camera are perpendicular to the long sides of the test pool, a connecting line of LUS00577 the first high-speed camera and the second high-speed camera is parallel to the long sides of the test pool, a travel-in trigger line within the field range of the first high- speed camera is superposed with a selected travel-in boundary line entering the measurement section of the unmanned ship in the test pool, a travel-out trigger line within the field range of the second high-speed camera is superposed with a selected travel-out boundary line that the unmanned ship leaves the measurement section in the test pool;

step 6, making the unmanned ship autonomously navigate along the track line in the test pool according to a task instruction, emitting an ultrasonic wave beam into the underwater in a process of moving the transducer of the to-be-detected ADCP along with the unmanned ship, generating irregular scatter on sound waves by suspended matters or silt in a water body, receiving scatter etches by a receiving transducer, enabling the transducer of the to-be-detected ADCP to uniformly pass through the measurement section after the transducer of the to-be-detected ADCP is accelerated to a set speed, and performing real-time monitoring, analysis and storage of navigation speed on a ground measurement base station of the GPS measurement instrument through a wireless bridge;

step 7, monitoring a view field area in real time through the first high-speed camera, extracting a pool surface profile line within the field range of the first high- speed camera of the test pool through characteristic difference in color and texture of a pool surface of the test pool and other background objects in the view field, and discriminating a dynamic object in the profile line through a method of making difference frame by frame to compare, thereby reducing wrong discrimination on a moving object outside the pool surface within the field range of the first high-speed LUS00577 camera,

step 8, recording a time point through the first high-speed camera in real time when the moving object passes through the travel-in trigger line of the first high- speed camera, adopting a particle filter algorithm to dynamically track the moving object in real time, obtaining profile characteristics of the moving object through algorithms of mean filtering, edge detection and the like, comparing the profile characteristics with pre-stored profile characteristics of the unmanned ship to judge whether the detected moving object is the travel-in unmanned ship, transferring to step 9 if yes, if no, stopping tracking and recording on the object, and repeating step 8;

step 9, tracing back an image that the unmanned ship reaches the travel-in trigger line recorded by the first high-speed camera, determining precise time that the unmanned ship firstly enters the travel-in trigger line of the first high-speed camera to serve as starting time t as that the unmanned ship enters the measurement section, and recording the time point as t ae in real time by the first high-speed camera while the tail of the unmanned ship passes through the travel-out trigger line of the first high- speed camera,

step 10, monitoring a view field area in real time through the second high-speed camera, extracting a pool surface profile line within the field range of the second high-speed camera of the test pool through characteristic difference in color and texture of a pool surface of the test pool and other background objects in the view field, and discriminating a dynamic object in the profile line through a method of making difference frame by frame to compare, thereby reducing wrong discrimination on a moving object outside the pool surface within the field range of the second high- speed camera,

step 11, recording a time point through the second high-speed camera in real LUS00577 time when the moving object passes through the travel-in trigger line of the second high-speed camera, adopting a particle filter algorithm to dynamically track the moving object in real time, obtaining profile characteristics of the moving object through algorithms of mean filtering, edge detection and the like, comparing the profile characteristics with pre-stored profile characteristics of the unmanned ship to judge whether the detected moving object is the travel-in unmanned ship, transferring to step 12 if yes, if no, stopping tracking and recording on the object, and repeating step 11;

step 12, tracing back an image that the unmanned ship reaches the travel-in trigger line recorded by the second high-speed camera, determining precise time t bs that the unmanned ship firstly enters the travel-in trigger line of the second high-speed camera again, and recording the time point in real time by the first high-speed camera as end time t be that the unmanned ship travels out of the measurement section while the tail of the unmanned ship passes through the travel-out trigger line of the first high-speed camera;

step 13, precisely metering the length L of the measurement section by the total station instrument, precisely metering a distance between the travel-in trigger line and the travel-out trigger line of the first high-speed camera by the total station instrument, precisely metering a distance between the travel-in trigger line and the travel-out trigger line of the second high-speed camera by the total station instrument, and calculating the speed of passing through the measurement section, the distance L1 between the two trigger lines of the first high-speed camera and the distance L2 between the two trigger lines of the high-speed camera 9 of the unmanned ship through formulas 1 to 3;

I LU500577 VS ee (13: foo = Fu 07 a 0 fe Tin step 14, uniformly selecting m flow velocity values from the original data of the transducer of the to-be-detected ADCP to calculate an arithmetical mean as a flow velocity measurement value to be compared with the standard flow velocity value calculated in step 13 to realize calibration on flow velocity parameters, where m is greater than or equal to 30; step 15, repeating step 6 to step 14 to repeatedly measure for 10 times, thereby realizing calibration on the flow velocity parameters of the to-be-detected ADCP.

Further, if v is greater than or equal to vi and smaller than or equal to v2 in step 13, v serves as the standard flow velocity value; if v is smaller than or equal to vi or v is greater than or equal to vs, |v-vı | is compared with [v-v> |; if |v-vı | is smaller than |v-v2 |, v=vı serves as the standard flow velocity value; and if |v-v1 | is greater than |v-v2 |, v=v2 serves as the standard flow velocity value.

Further, the flow direction calibration method specifically includes the following steps: step 1, adjusting an included angle between the indication direction of the to-be- detected ADCP and the central axis of the unmanned ship to a selected angle value by the precise angle turntable; step 2, enabling the unmanned ship to uniformly travel along the track line, setting the GPS measurement instrument to acquire position information of the unmanned ship in real time with a sampling rate of 1 Hz, comparing the position information with coordinate information of the track line to calculate navigation LUS00577 direction deviation errors at different moments, and synthesizing the set direction value of the precise angle turntable with the navigation direction deviation value vector to serve as a standard flow direction value at the moment; step 3, acquiring 10 flow direction indication values, at the measurement section, of the to-be-detected ADCP, and selecting the flow direction indication value at the same moment to compare and analyze the flow direction standard value, and calculating flow direction indication value errors; step 4, within the range of 0° to 180°, uniformly selecting 7 angle values of 0°, 30°, 60°, 90°, 120°, 150° and 180°, repeating step 1 to 3 to calibrate the flow direction parameters of the transducer of the to-be-detected ADCP.

The present invention has the beneficial effects that: the test pool is a regular semi-sealed rectangular ship gate with a length of 180 m, a width of 25 m and a depth of 10 m; while sealed, the gate is free of influences factors such as tides, wind waves and water flow, and the water body is provided with suspended matters and stratified flow fields, so that the test pool is an excellent calibration site of the ADCP; the rectangular ship gate is positioned at an entrance for connecting the river to the seat, the stratified flow fields can be generated by adjusting the opening amplitude of the gate, so that flow velocity calibration environment can be provided for the ADCP; back scatters such as silt and floating microorganisms needed for acoustic Doppler shift measurement principle are contained in a water body in the test pool. The 150 m measurement section can guarantee that the ADCP continuously acquires data for at least 30 s, a 25 m-wide water area can avoid boundary reverberation interference of an ADCP beam opening angle, a 10m water depth can guarantee that the ADCP performs stratified flow velocity acquisition outside the measurement blind zone,

which provides the possibility for the present invention of the calibration method. The LUS00577 novel unmanned ship has the advantages of being light, high instability, and super- strong in carrying compatibility, and is used for driving the to-be-detected ADCP to move in the test pool according to the set direction and the set speed; the adapter bracket is used for fixing the GPS measurement instrument and the precise angle turntable onto the unmanned ship; the GPS measurement instrument is used for receiving a GPS signal to realize absolute coordinate positioning of the unmanned ship; the precise angle turntable is used for adjusting an angle between the transducer of the to-be-detected ADCP and the front-end central axis of the unmanned ship, so that calibration on the flow direction parameters of the transducer of the ADCP is realized; the adapter flange plate is used for fixedly connecting the precise angle turntable to the transducer of the ADCP; the first high-speed camera and the second high-speed camera are used for monitoring whether the unmanned ship enters the detected area in real time; a trigger line is set in respective view field range to record the time that the unmanned ship enters and exits the detected area; average velocity, in the detected area, of the unmanned ship is calculated as the standard flow velocity value to compare with flow velocity measured results of the transducer of the ADCP ; and the total station instrument is used for sampling the track line that the unmanned ship travels, and measuring the distance between the two trigger lines of the first high- speed camera, the distance between the two trigger lines of the second high-speed camera and the length of the measurement section.

The unmanned ship drives the ADCP to sail back and forth along the track line to measure channel flow velocity, the high-speed cameras and total station equipment with a traceable magnitude measure average velocity of the ADCP in the measurement section, the average velocity of the ADCP serves as a reference standard value to be compared with an flow velocity indication value of the ADCP, and flow LUS00577 velocity parameter calibration 1s conducted; through the precise angle turntable, an included angle between an indication direction of the ADCP and a navigation direction is adjusted, a movement track and yaw errors of the unmanned ship are plotted, a flow direction reference standard value is calculated and compared with a flow direction indication value of the ADCP, and flow direction parameter calibration is carried out.

The calibration method can meet flow velocity and flow direction calibration requirements of the ADCP in shallow-water areas such as ports and channels, marine traffic engineering, and offshore coast, solves various problems in the metering performance calibration process of the ADCP, establishes a value traceability chain between a metering instrument and metering standards, and guarantees the values of the flow velocity and the flow direction of the ADCP to be unified, accurate and reliable.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a schematic diagram showing the principle of a calibration method of the present invention; FIG. 2 is a schematic diagram showing a structure of a calibration device in Embodiment 1 of the present invention; FIG. 3 1s a schematic diagram showing installation of a precision angle turntable, an adapter flange plate, and a to-be-detected acoustic Doppler flow profiler in Embodiment 1 of the present invention; FIG. 4 is a schematic diagram showing a structure of a calibration device in Embodiment 2 of the present invention;

FIG. 5 is a schematic diagram showing a structure of a liquid filling bag in LUS00577 Embodiment 2 of the present invention.

In the figures: 1, test pool; 2, unmanned ship; 3, adapter bracket; 4, GPS measurement instrument; 5, precise angle turntable; 6, adapter flange plate; 7, to-be- detected acoustic Doppler flow profiler; 8, first high-speed camera; 9, second high- speed camera; 10, total station instrument; 11, long-side walls of test pool; 12, short- side walls of test pool; 13, track line; 14, travel-in trigger line of first high-speed camera; 15, travel-out trigger line of first high-speed camera; 16, travel-in trigger line of second high-speed camera 17; travel-out trigger line of second high-speed camera; 18, zero indication sign; 19, acceleration section; 20, measurement section; 21, deceleration section; 22, counterweight adjusting bin; 23, liquid filling bag; 24, liquid charging and discharging hole; and 25, protective cap.

DESCRIPTION OF THE INVENTION The specific embodiments of the present invention will be described below in conjunction with the drawings.

An acoustic Doppler current profiler calibration device based on an unmanned ship includes a test pool 1, the unmanned ship 2, an adapter bracket 3, a GPS measurement instrument 4, a precise angle turntable 5, a first high-speed camera 8, a second high-speed camera 9 and a total station instrument 10; where the adapter bracket 3 1s fixedly arranged on the unmanned ship 2; the upper part of the adapter bracket 3 is connected with the GPS measurement instrument 4; the precise angle turntable 5 is connected with a to-be-detected acoustic Doppler current profiler 7 through an adapter flange plate 6, and a connecting line of the first high-speed camera 8 and the second high-speed camera 9 is parallel to the long side of a test pool and is far away from the test pool 1; the total station instrument 10 is positioned at one side,

away from the test pool 1, of the connecting line of optical centers of the first high- LUS00577 speed camera 8 and the second high-speed camera 9.

Axes of the optical centers of the first high-speed camera 8 and the second high- speed camera 9 are perpendicular to the long side of the test pool, and the total station instrument is positioned on a perpendicular bisector of the first high-speed camera and the second high-speed camera.

Axes of the GPS measurement instrument 4, the precise angle turntable 5, the adapter flange plate 6 and the to-be-detected acoustic Doppler current profiler 7 are superposed.

The dimension of the unmanned ship is that length 1.5 m x width 0.4 m x height

0.3 m, and the highest operation speed of the unmanned ship is 5 m/s.

The test pool 1 is divided into an acceleration section, a measurement section and a deceleration section according to an operation state of the unmanned ship; the length of the acceleration section is not smaller than a distance that the unmanned ship travels while accelerating to the highest speed from a static state; the length of the deceleration section is not smaller than a distance that the unmanned ship travels while decelerating to the static state from the highest speed; the measurement section serves as a detection area for flow velocity parameter calibration of the to-be-detected acoustic Doppler current profiler, and the length of the measurement section is not smaller than a distance that the unmanned ship uniformly travels for 30 s with the highest operation speed.

A connecting line of midpoints of two short-side walls of the test pool 1 is taken LUS00577 as a track line 13 that the unmanned ship travels, and the track line 13 1s parallel to the long side walls of the test pool 1. Midpoints of two short-side walls of the test pool 1 are precisely positioned through the total station instrument 10; a connecting line of midpoints of two short-side walls of the test pool 1 is taken as a track line 13 that the unmanned ship travels, and the track line is parallel to the long-side walls of the test pool 1; and when the unmanned ship 2 travels, absolute coordinate positions thereof are received and corrected in real time through the GPS measurement instrument, so that displacement of deviating away from the track line does not exceed 20 mm throughout the whole travelling process.

The first high-speed camera 8 and the second high-speed camera 9 are of the same-model high-speed camera, a frame rate of the first high-speed camera 8 and the second high-speed camera 9 is 30 fps or more; a trigger line for allowing the unmanned ship to travel in and out is arranged in each field range of the first high- speed camera 8 and the second high-speed camera 9, the trigger line entering the field range of the first high-speed camera is superposed with a selected boundary line entering the measurement section of the unmanned ship in the test pool, the trigger line leaving the field range of the second high-speed camera is superposed with the selected boundary line leaving the measurement section of the unmanned ship in the test pool; and the sizes of the view fields of the first high-speed camera 8 and the second high-speed camera 9 should guarantee that the unmanned ship 2 can uniformly operate for 30 s for more with the highest operation speed in the trigger area of each high-speed camera.

An acoustic Doppler current profiler calibration method based on an unmanned ship includes a flow velocity calibration method and a flow direction calibration method. The flow velocity calibration method is as follows: the unmanned ship drives LUS00577 a to-be-detected Acoustic Doppler Current Profiler (ADCP) to sail back and forth along a center line, namely a track line, of the short side of a pool to measure channel flow velocity, a first high-speed camera, a second high-speed camera and total station equipment with a traceable magnitude measure average velocity of the ADCP in a measurement section, the average velocity serves as a reference standard value to be compared with a flow velocity indication value of the ADCP, and flow velocity parameter calibration is conducted.

The flow velocity calibration method specifically includes the following steps: step 1, mounting the to-be-detected ADCP to the bottom of the unmanned ship through the adapter flange plate, adjusting a zero-indication sign of the to-be-detected ADCP to be superposed with that of the precise angle turntable, accessing a communication cable connected with a transducer of the to-be-detected ADCP into an electronic watertight compartment of the unmanned ship, and stably hoisting the unmanned ship to the test pool, step 2, normally starting the unmanned ship, the to-be-detected ADCP, the first high-speed camera and the second high-speed camera, and establishing time synchronizing datum among the unmanned ship, the transducer of the to-be-detected

ADCP, the first high-speed camera and the second high-speed camera based on LUS00577 second pulse of the GPS measurement instrument; step 3, sampling two parallel virtual straight lines which are equal in length of 180 m by the total station instrument, where one straight line is parallel to the long sides of the test pool and passes through midpoints of the short sides of the test pool to serve as a set track line that the unmanned ship travels, and the other straight line is positioned at one side of the first high-speed camera and one side of the second high- speed camera to serve as a metering standard line.

step 4, dividing the long sides of the test pool into an acceleration section, a measurement section and a deceleration section according to the length of the test pool and the highest traveling speed of the unmanned ship, determining the metering standard line sampled by the total station instrument for absolute coordinates of partition points of each section, recording absolute coordinate values of a start point and an end point of the measurement section on a set track line corresponding to the metering standard line, and inputting the absolute coordinate values into control software of a platform system of the unmanned ship for route instruction edition; step 5, separately mounting the first high-speed camera and the second high- speed camera on a start position and an end position of the measurement section, where axes of optical centers of the first high-speed camera and the second high- speed camera are perpendicular to the long sides of the test pool, a connecting line of the first high-speed camera and the second high-speed camera is parallel to the long sides of the test pool, a travel-in trigger line within the field range of the first high- speed camera is superposed with a selected travel-in boundary line entering the measurement section of the unmanned ship in the test pool, a travel-out trigger line within the field range of the second high-speed camera is superposed with a selected travel-out boundary line that the unmanned ship leaves the measurement section in the LUS00577 test pool;

step 7, monitoring a view field area in real time through the first high-speed camera, extracting a pool surface profile line within the field range of the first high- speed camera of the test pool through characteristic difference in color and texture of a pool surface of the test pool and other background objects in the view field, and discriminating a dynamic object in the profile line through a method of making difference frame by frame to compare, thereby reducing wrong discrimination on a moving object outside the pool surface within the field range of the first high-speed camera,

step 8, recording a time point through the first high-speed camera in real time when the moving object passes through the travel-in trigger line of the first high- speed camera, adopting a particle filter algorithm to dynamically track the moving object in real time, obtaining profile characteristics of the moving object through algorithms of mean filtering, edge detection and the like, comparing the profile characteristics with pre-stored profile characteristics of the unmanned ship to judge LUS00577 whether the detected moving object is the travel-in unmanned ship, transferring to step 9 if yes, if no, stopping tracking and recording on the object, and repeating step 8;

step 9, tracing back an image that the unmanned ship reaches the travel-in trigger line recorded by the first high-speed camera, determining precise time that the unmanned ship firstly enters the travel-in trigger line of the first high-speed camera to serve as starting time t as that the unmanned ship enters the measurement section, and recording the time point as t ae in real time by the first high-speed camera while the tail of the unmanned ship passes through the travel-out trigger line of the first high- speed camera;

step 10, monitoring a view field area in real time through the second high-speed camera, extracting a pool surface profile line within the field range of the second high-speed camera of the test pool through characteristic difference in color and texture of a pool surface of the test pool and other background objects in the view field, and discriminating a dynamic object in the profile line through a method of making difference frame by frame to compare, thereby reducing wrong discrimination on a moving object outside the pool surface within the field range of the second high- speed camera;

step 11, recording a time point through the second high-speed camera in real time when the moving object passes through the travel-in trigger line of the second high-speed camera, adopting a particle filter algorithm to dynamically track the moving object in real time, obtaining profile characteristics of the moving object through algorithms of mean filtering, edge detection and the like, comparing the profile characteristics with pre-stored profile characteristics of the unmanned ship to judge whether the detected moving object is the travel-in unmanned ship, transferring to step 12 if yes, if no, stopping tracking and recording on the object, and repeating LUS00577 step 11; step 12, determining precise time t bs that the unmanned ship firstly enters the travel-in trigger line of the second high-speed camera by tracking back the image that the unmanned ship reaches the travel-in trigger line through the second high-speed camera, and recording the time point in real time by the first high-speed camera as end time t be that the unmanned ship travels out of the measurement section while the tail of the unmanned ship passes through the travel-out trigger line of the first high- speed camera; step 13, precisely metering the length L of the measurement section by the total station instrument, precisely metering a distance between the travel-in trigger line and the travel-out trigger line of the first high-speed camera by the total station instrument, precisely metering a distance between the travel-in trigger line and the travel-out trigger line of the second high-speed camera by the total station instrument, and calculating the speed of passing through the measurement section, the distance L1 between the two trigger lines of the first high-speed camera and the distance L2 between the two trigger lines of the high-speed camera 9 of the unmanned ship through formulas 1 to 3; y= wk (13

SN Pr 2 nen (3) Chel step 14, uniformly selecting m flow velocity values from the original data of the transducer of the to-be-detected ADCP to calculate an arithmetical mean as a flow velocity measurement value to be compared with the standard flow velocity value LUS00577 calculated in step 13 to realize calibration on flow velocity parameters, where m is greater than or equal to 30; step 15, repeating the step 6 to step 14 to repeatedly measure for 10 times, thereby realizing calibration on flow velocity parameters of the ADCP.

Further, if v is greater than or equal to vi and smaller than or equal to v2 in step 13, v serves as the standard flow velocity value; if v is smaller than or equal to vi or v is greater than or equal to vs, |v-vı | is compared with |v-v> |; if |v-vı | is smaller than |v-v2 |, v=vı serves as the standard flow velocity value; and if |v-v1 | is greater than |v-v2 |, v=v2 serves as the standard flow velocity value.

Further, the flow direction calibration method specifically includes the following steps: step 1, adjusting an included angle between the indication direction of the to-be- detected ADCP and the central axis of the unmanned ship to a selected angle value by the precise angle turntable; step 2, enabling the unmanned ship to uniformly travel along the track line, setting the GPS measurement instrument to acquire position information of the unmanned ship in real time with a sampling rate of 1Hz, comparing the position information with coordinate information of the track line to calculate navigation direction deviation errors at different moments, and synthesizing the set direction value of the precise angle turntable with the navigation direction deviation value vector to serve as a standard flow direction value at the moment; step 3, acquiring 10 flow direction indication values, at the measurement section, of the to-be-detected ADCP, and selecting the flow direction indication value at the same moment to compare and analyze the flow direction standard value, and LUS00577 calculating flow direction indication value errors; and step 4, within the range of 0° to 180°, uniformly selecting 7 angle values of 0°, 30°, 60°, 90°, 120°, 150° and 180°, repeating step 1 to 3 to calibrate the flow direction parameters of the transducer of the to-be-detected ADCP.

Embodiment 1 As shown in FIG. 1 to FIG. 3, an acoustic Doppler current profiler calibration device and method based on an unmanned ship includes a flow velocity calibration device, a flow direction calibration device and a test pool 1. The flow velocity calibration device includes an unmanned ship 2, an adapter bracket 3, a GPS measurement instrument 4, a first high-speed camera 8, a second high-speed camera 9 and a total station instrument 1, the adapter bracket 3 is fixedly arranged on the unmanned ship 2, the adapter bracket adopts lifting and 360-degree rotating functions to adjust underwater depth and a rotation angle of the to-be-detected ADCP, the upper part of the adapter bracket 3 is connected to the GPS measurement instrument 4, and the lower part of the adapter bracket 3 1s connected to the precise angle turntable 5; the precise angle turntable 5 is connected to a transducer of the to-be-detected ADCP 7 through an adapter flange plate 6; the axes of the GPS measurement instrument 4, the precise angle turntable 5, the flange plate 6 and the ADCP 7 are superposed; the first high-speed camera 8 and the second high-speed camera 9 are placed on the long sides 11 of the test pool 1; the axes of optical centers of the first high-speed camera 8 and the second high-speed camera 9 are perpendicular to the long sides 11 of the test pool 1; a connecting line of optical centers of the first high-speed camera 8 and the second high-speed camera 9 is parallel to the long sides 11 of the test pol 1; and the total station instrument 1 is positioned at sides, way from the test pool 1, of the optical LUS00577 centers of the first high-speed camera 8 and the second high-speed camera 9.

The test pool 1 1s used for providing a stable test site with suspended matters and stratified flow fields for calibration test of the transducer of the to-be-detected ADCP. The unmanned ship 2 has a dimension of 1.5m (length) x 0.4m (width) x 0.3m (depth), has highest operation speed of 5 m/s, takes a high-polymer polyester carbon fiber as a ship body material, and has the characteristics of being compact in structure, small in travelling resistance, firm and durable, and the like while having enough carrying load ability; as a carrier of the to-be-detected ADCP 7, the unmanned ship is used for driving the to-be-detected ADCP 7 to move according to a set direction and set speed in the test pool 1; the adapter bracket 3 is used for fixing the GPS measurement instrument 4 and the precise angle turntable 5 onto the unmanned ship 2; the GPS measurement instrument 4 is used for receiving a GPS signal to realize absolute coordinate positioning of the unmanned ship 2; the precise angle turntable 5 is used for adjusting an angle between the transducer of the to-be-detected ADCP 7 and the front-end central axis of the unmanned ship 2, so that calibration on flow direction parameters of the to-be-detected ADCP is realized; the adapter flange plate 6 is used for fixedly connecting the precise angle turntable 5 to the to-be-detected ADCP; the first high-speed camera 8 and the second high-speed camera 9 are used for monitoring whether the unmanned ship 2 enters the detected area in real time, recording the time that the unmanned ship 2 enters and exists the detected area by setting trigger lines in respective view field ranges, calculating average velocity in the detected area of the unmanned ship 2 as a standard flow velocity value to be compared with flow velocity measured results of the to-be-detected ADCP; the total station instrument 1 is used for sampling the track line that the unmanned ship 2 travels, and midpoints of two short-side walls of the test pool 1 are precisely LUS00577 positioned through the total station instrument 1; the connecting line of midpoints of two short-side walls 12 of the test pool 1 is taken as the track line that the unmanned ship 2 travels, and the track line is parallel to the long-side walls 11 of the test pool 1; when the unmanned ship 2 travels, the absolute coordinate positions thereof are received and corrected in real time through the GPS measurement instrument 4, and the displacement of deviating away from the track line 13 does not exceed 20 mm throughout the whole travelling process; and meanwhile, the total station instrument is used for measuring a distance between two trigger lines of the first high-speed camera, a distance between two trigger lines of the second high-speed camera 9 and the length of the measurement section 20.

The test pool 1 is divided into an acceleration section, a measurement section and a deceleration section according to an operation state of the unmanned ship 2; the length of the acceleration section 19 is not smaller than a distance that the unmanned ship 2 travels while accelerating to the highest speed from a static state; the length of the deceleration section 13 is not smaller than a distance that the unmanned ship 2 travels while decelerating to the static state from the highest speed; the measurement section 20 serves as a detection area for flow velocity parameter calibration of the to- be-detected ADCP 7, the length of the measurement section is not smaller than a distance that the unmanned ship 2 uniformly travels for 30 s with the highest operation speed, and the length is precisely measured through the total station instrument 1.

The first high-speed camera 8 and the second high-speed camera 9 are of the same-model high-speed camera, a frame rate of the first high-speed camera and the second high-speed camera is 30 fps or more; a trigger line for allowing the unmanned ship to travel in and out is arranged in each field range of the two cameras, the travel- LUS00577 in trigger line 14 within the field range of the first high-speed camera 8 is superposed with a selected boundary line entering the measurement section 20 of the unmanned ship 2 in the test pool 1, the travel-out trigger line 17 within the field range of the second high-speed camera 1s superposed with the selected boundary line leaving the measurement section 20 of the unmanned ship 2 in the test pool 1; and the sizes of the view fields of the first high-speed camera 8 and the second high-speed camera 9 should guarantee that the unmanned ship 2 can uniformly operate for 30 s for more with the highest operation speed in the trigger area of each high-speed camera.

An acoustic Doppler current profiler calibration device and method based on an unmanned ship includes a flow velocity calibration method and a flow direction calibration method, where the flow velocity calibration method specifically includes the following steps: step 1, mounting the to-be-detected ADCP 7 to the bottom of the unmanned ship 2 through the adapter flange plate 6, adjusting a zero-indication sign of the to-be- detected ADCP 7 to be superposed with a zero-indication sign 18 of the precise angle turntable 5, accessing a communication cable connected with a transducer of the to- be-detected ADCP 7 into an electronic watertight compartment of the unmanned ship 2, and stably hoisting the unmanned ship 2 to the test pool 1; step 2, normally starting the unmanned ship 2, the to-be-detected ADCP 7, the first high-speed camera 8 and the second high-speed camera 9, and establishing time synchronizing datum among the unmanned ship, 2 the transducer of the to-be-detected ADCP 7, the first high-speed camera 8 and the second high-speed camera 9 based on second pulse (1pps) of the GPS measurement instrument 4;

step 3, sampling two parallel virtual straight lines which are equal in length of LUS00577 180 m by the total station instrument 1, where one straight line 1s parallel to the long sides of the test pool 1 and passes through midpoints of the short sides of the test pool 1 to serve as a set track line 13 that the unmanned ship 2 travels, and the other straight line is positioned at one side of the first high-speed camera 8 and one side of the second high-speed camera 9 to serve as a metering standard line.

step 4, dividing the long sides of the test pool into an acceleration section 19, a measurement section 20 and a deceleration section 21 according to the length of the test pool 1 and the highest traveling speed of the unmanned ship 2, determining the metering standard line sampled by the total station instrument 1 for absolute coordinates of partition points of each section, recording absolute coordinate values of a start point and an end point of the measurement section 20 on a set track line corresponding to the metering standard line, and inputting the absolute coordinate values into control software of a platform system of the unmanned ship 20 for route instruction edition; step 5, separately mounting the first high-speed camera 8 and the second high- speed camera 9 on a start position and an end position of the measurement section 20, where axes of optical centers of the first high-speed camera 8 and the second high- speed camera 9 are perpendicular to the long sides of the test pool 1, a connecting line of optical centers of the first high-speed camera 8 and the second high-speed camera 9 is parallel to the long sides of the test pool 1, a travel-in trigger line 14 within the field range of the first high-speed camera 8 is superposed with a selected travel-in boundary line entering the measurement section 20 of the unmanned ship 2 in the test pool 1, a travel-out trigger line 17 within the field range of the second high-speed camera 9 is superposed with a selected travel-out boundary line that the unmanned LUS00577 ship 2 leaves the measurement section 20 in the test pool 1;

step 6, making the unmanned ship 2 autonomously navigate along the track line in the test pool 1 according to a task instruction, emitting an ultrasonic wave beam into the underwater in a process of moving the transducer of the to-be-detected ADCP 7 along with the unmanned ship 2, generating irregular scatter on sound waves by suspended matters or silt in a water body, receiving scatter etches by a receiving transducer, enabling the transducer of the to-be-detected ADCP 7 to uniformly pass through the measurement section 20 after the transducer of the to-be-detected ADCP 7 is accelerated to a set speed, and performing real-time monitoring, analysis and storage of navigation speed on a ground measurement base station of the GPS 4 through a wireless bridge;

step 7, monitoring a view field area in real time through the first high-speed camera 8, extracting a pool surface profile line within the field range of the first high- speed camera 8 of the test pool 1 through characteristic difference in color and texture of a pool surface of the test pool 1 and other background objects in the view field, and discriminating a dynamic object in the profile line through a method of making difference frame by frame to compare, thereby reducing wrong discrimination on a moving object outside the pool surface within the field range of the first high-speed camera 8;

step 8, recording a time point through the first high-speed camera 8 in real time when the moving object passes through the travel-in trigger line 14 of the first high- speed camera 8, adopting a particle filter algorithm to dynamically track the moving object in real time, obtaining profile characteristics of the moving object through algorithms of mean filtering, edge detection and the like, comparing the profile characteristics with pre-stored profile characteristics of the unmanned ship 2 to judge LUS00577 whether the detected moving object 1s the travel-in unmanned ship 2, transferring to step 9 if yes, if no, stopping tracking and recording on the object, and repeating step 8;

step 9, tracing back an image that the unmanned ship 2 reaches the travel-in trigger line 14 recorded by the first high-speed camera 8, determining precise time that the unmanned ship 2 firstly enters the travel-in trigger line of the first high-speed camera 8 to serve as starting time tas that the unmanned ship 2 enters the measurement section 20, and recording the time point as t ae in real time by the first high-speed camera 8 while the tail of the unmanned ship 2 passes through the travel- out trigger line 15 of the first high-speed camera 8;

step 10, monitoring a view field area in real time through the second high-speed camera 9, extracting a pool surface profile line within the field range of the second high-speed camera 9 of the test pool 1 through characteristic difference in color and texture of a pool surface of the test pool 1 and other background objects in the view field, and discriminating a dynamic object in the profile line through a method of making difference frame by frame to compare, thereby reducing wrong discrimination on a moving object outside the pool surface within the field range of second high- speed camera 9;

step 11, recording a time point through the second high-speed camera 9 in real time when the moving object passes through the travel-in trigger line of the second high-speed camera 9, adopting a particle filter algorithm to dynamically track the moving object in real time, obtaining profile characteristics of the moving object through algorithms of mean filtering, edge detection and the like, comparing the profile characteristics with pre-stored profile characteristics of the unmanned ship 2 to judge whether the detected moving object is the travel-in unmanned ship 2,

transferring to step 12 if yes, if no, stopping tracking and recording on the object, and LUS00577 repeating step 11; step 12, tracing back an image that the unmanned ship 2 reaches the travel-in trigger line 16 recorded by the second high-speed camera 9, determining precise time t bs that the unmanned ship 2 firstly enters the travel-in trigger line of the second high-speed camera 2 again, and recording the time point in real time by the first high- speed camera 8 as end time t be that the unmanned ship 2 travels out of the measurement section 20 while the tail of the unmanned ship 2 passes through the travel-out trigger line 17 of the first high-speed camera 8; step 13, precisely metering the length L of the measurement section 20 by the total station instrument 10, precisely metering a distance between the travel-in trigger line 14 and the travel-out trigger line 15 of the first high-speed camera by the total station instrument, precisely metering a distance between the travel-in trigger line 16 and the travel-out trigger line 17 of the second high-speed camera by the total station instrument, and calculating the speed of passing through the measurement section 20, the distance L1 between the two trigger lines of the first high-speed camera 8 and the distance L2 between the two trigger lines of the high-speed camera 9 of the unmanned ship 2 through formulas 1 to 3; ps ee GP Di as = ae {2 Fe Ua bye Bar step 14, uniformly selecting m flow velocity values from the original data of the transducer of the to-be-detected ADCP to calculate an arithmetical mean as a flow velocity measurement value to be compared with the standard flow velocity value LUS00577 calculated in step 13 to realize calibration on flow velocity parameters, where m is determined according to the dimension of the test pool 1 and the velocity of the unmanned ship 2, and is generally greater than or equal to 30; step 15, repeating step 6 to step 14 to repeatedly measure for 10 times, thereby realizing calibration on the flow velocity parameters of the to-be-detected ADCP 7.

The flow direction calibration method specifically includes the following steps: step 1, making preparation and test conditions of flow direction calibration as well as installation and setting of the ADCP to be consistent with those of the flow velocity calibration method; step 2, adjusting an included angle between the indication direction of the to-be- detected ADCP 7 and the central axis of the unmanned ship 2 to a selected angle value by the precise angle turntable 5; step 3, enabling the unmanned ship 2 to uniformly travel at 3 m/s along the track line, setting the GPS measurement instrument 4 to acquire position information of the unmanned ship 2 in real time with a sampling rate of 1Hz, comparing the position information with coordinate information of the track line to calculate navigation direction deviation errors at different moments, and synthesizing the set direction value of the precise angle turntable 5 with the navigation direction deviation value vector to serve as a standard flow direction value at the moment;

step 4, acquiring 10 flow direction indication values, at the measurement section LUS00577 20, of the to-be-detected ADCP, and selecting the flow direction indication value at the same moment to compare and analyze the flow direction standard value, and calculating flow direction indication value errors; step 5, within the range of 0° to 180°, uniformly selecting 7 angle values of 0°, 30°, 60°, 90°, 120°, 150° and 180°, repeating step 2 to 4 to calibrate the flow direction parameters of the transducer of the to-be-detected ADCP.

During work, the flow velocity calibration method and the flow direction calibration method are adopted to dynamically calibration flow speed and flow direction measured data output from the transducer of the ADPC, and measured data are as shown in Table 1 and Table 2.

Table 1 Flow Velocity Parameter Calibration of ADCP Serial | ADCP flow velocity indication value V Flow veloaity Indication value number (m/s) standard value errors V(m/s m/s

2.942 2.936 0.006

2.969 2.954 0.015

3.015 3.001 0.014

2.977 2.945 0.032

2.984 2.968 0.016 | 6 | 2.925 2.898 0.027

2.932 2.915 0.017 | 8 | 2.986 2.967 0.019 | 9 | 3.031 3.010 0.021

2.996 2.984 0.012

Table 2 Flow Direction Parameter Calibration of ADCP LUS00577 RE RE Indication value Time moment ADCP flow direction Flow direction errors indication value (0) standard value (0) 0) 10:05:00 L.. 12 | 04 | 08 | 10:05:10 | 97 | 09 | 16 | 10:05:20 |. 06 | 12 | 96 | 10:05:30 10:05:40 10:05:50 10:06:00 10:06:10 |. 08 | 10 | A8 | 10:0620 | 15 | 07 | 08 | 10:06:30 |. 09 | 03 | 12 | In an engineering application process, the maximum allowable errors of the flow velocity are required to be vx1%+0.005m/s, and the maximum allowable errors of the flow direction are required to be +5°; it can be seen from the measured results of Table 1 and Table 2 that the acoustic Doppler current profiler calibration device and method based on the unmanned ship in the present invention have indication value errors far smaller than the maximum allowable errors in engineering application, has the advantages of high measuring precision, high speed, good flexibility and easy implementation, and have important significance in improving accuracy, stability and reliability of the measured data of the acoustic Doppler current profiler, and normalizing use and management of the acoustic Doppler current profiler.

Embodiment 2 In addition to the technical scheme, the prevent invention further adopts the following technical scheme: A counterweight adjusting bin 22 in which a liquid filling bag 23 made of an elastic material and having certain strength is arranged in the unmanned ship 2; a liquid charging and discharging hole 24 with a protective cap 25 thereon is formed in the liquid filling bag; the liquid charging and discharging hole 24 is connected to the LUS00577 protective cap 25 through a detachable connecting structure which is threaded connection. Counterweight is adjusted by adjusting liquid filling amount of the liquid filling bag 23 in the counterweight adjusting bin 22, so that the gravity center of the unmanned ship 2 is kept stable to prevent the unmanned ship from overturn, and the adapter bracket of the unmanned ship 2 is perpendicular to a still water surface; the lower end of the adapter bracket is connected to the to-be-detected ADCP, so that measured flow velocity and flow direction data of the to-be-detected ADCP are prevented from generating errors.

Compared with the prior art, the design is reasonable; the test pool is a regular semi-sealed rectangular ship gate with a length of 180 m, a width of 25 m and a depth of 10 m; while the gate is closed, the pool is free of influence factors such as tides, wind waves and water flow, and the water body is provided with suspended matters and stratified flow fields, and therefore, the pool is an excellent calibration site of the ADCP; the rectangular ship gate is positioned at an entrance for connecting the river to the seat, the stratified flow fields can be generated by adjusting the opening amplitude of the gate, so that flow velocity calibration environment can be provided for the ADCP; back scatters such as silt and floating microorganisms needed for acoustic Doppler shift measurement principle are contained in a water body in the test pool. The 150 m measurement section can guarantee that the ADCP continuously acquires data for at least 30 s, a 25 m-wide water area can avoid boundary reverberation interference of an ADCP beam opening angle, a 10m water depth can guarantee that the ADCP performs stratified flow velocity acquisition outside the measurement blind zone, which provides the possibility for the present invention of the calibration method. The unmanned ship 2 has the advantages of being light, high instability, and super-strong in carrying compatibility, and is used for driving the to- LUS00577 be-detected ADCP to move in the test pool according to the set direction and the set speed as a carrier of the ADCP; the adapter bracket 1s used for fixing the GPS measurement instrument and the precise angle turntable onto the unmanned ship; the GPS measurement instrument is used for receiving a GPS signal to realize absolute coordinate positioning of the unmanned ship; the precise angle turntable 1s used for adjusting an angle between the transducer of the to-be-detected ADCP and the front- end central axis of the unmanned ship, so that calibration on the flow direction parameters of the transducer of the ADCP is realized; the adapter flange plate is used for fixedly connecting the precise angle turntable 5 to the transducer of the ADCP; the first high-speed camera and the second high-speed camera are used for monitoring whether the unmanned ship enters the detected area in real time; a trigger line is set in respective view field range to record the time that the unmanned ship enters and exits the detected area; average velocity, in the detected area, of the unmanned ship is calculated as the standard flow velocity value to compare with flow velocity measured results of the transducer of the ADCP; and the total station instrument is used for sampling the track line that the unmanned ship travels, and measuring the distance between the two trigger lines of the first high-speed camera, the distance between the two trigger lines of the second high-speed camera and the length of the measurement section 20.

The unmanned ship drives the ADCP to sail back and forth along the track line to measure channel flow velocity, the high-speed cameras and total station equipment with a traceable magnitude measure average velocity of the ADCP in the measurement section, the average velocity of the ADCP serves as a reference standard value to be compared with an flow velocity indication value of the ADCP, and flow velocity parameter calibration is conducted; through the precise angle turntable, an LUS00577 included angle between an indication direction of the ADCP and a navigation direction is adjusted, a movement track and yaw errors of the unmanned ship are plotted, a flow direction reference standard value is calculated and compared with a flow direction indication value of the ADCP, and flow direction parameter calibration is carried out.

The embodiments of the present invention have been described in detail above, but the content is only the preferred embodiments of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equal changes and improvements made in accordance with the scope of the application of the present invention should still fall within the scope of the patent of the present invention.

Claims

CLAIMS LU500577

1. An acoustic Doppler current profiler calibration device based on an unmanned ship, comprising a test pool, the unmanned ship, an adapter bracket, a GPS measurement instrument, a first high-speed camera, a second high-speed camera, a total station instrument and a precise angle turntable, wherein the adapter bracket 1s fixedly arranged on the unmanned ship; the upper part of the adapter bracket is connected with the GPS measurement instrument; the precise angle turntable is connected with a to-be-detected acoustic Doppler current profiler through an adapter flange plate, and a connecting line of optical centers of the first high-speed camera and the second high-speed camera is parallel to the long side of a test pool and is far away from the test pool; the total station instrument is positioned at one side, away from the test pool, of the connecting line of optical centers of the first high-speed camera and the second high-speed camera.

2. The acoustic Doppler current profiler calibration device based on the unmanned ship according to claim 1, wherein axes of the optical centers of the first high-speed camera and the second high-speed camera are perpendicular to the long side of the test pool.

3. The acoustic Doppler current profiler calibration device based on the unmanned ship according to claim 2, wherein axes of the GPS measurement instrument, the precise angle turntable, the adapter flange plate and the to-be-detected acoustic Doppler current profiler are superposed, preferably, the dimension of the unmanned ship is that length 1.5 m x width 0.4 m x height 0.3 m, and the highest operation speed of the unmanned ship is 5 m/s.

4. The acoustic Doppler current profiler calibration device based on the unmanned ship according to claim 1, 2 or 3, wherein the test pool is divided into an acceleration section, a measurement section and a deceleration section according to an LUS00577 operation state of the unmanned ship; the length of the acceleration section is not smaller than a distance that the unmanned ship travels while accelerating to the highest speed from a static state; the length of the deceleration section is not smaller than a distance that the unmanned ship travels while decelerating to the static state from the highest speed; the measurement section serves as a detection area for flow velocity parameter calibration of the to-be-detected acoustic Doppler current profiler, and the length of the measurement section is not smaller than a distance that the unmanned ship uniformly travels for 30 s with the highest operation speed, the test pool 1s a regular semi-sealed rectangular ship gate with a length of 180 m, a width of 25 m and a depth of 10 m; and the test pool is a stable test site with suspended matters and stratified flow fields.

5. The acoustic Doppler current profiler calibration device based on the unmanned ship according to claim 1, 2 or 3, wherein a connecting line of midpoints of two short-side walls of the test pool is taken as a track line that the unmanned ship travels, and the track line is parallel to the long side walls of the test pool.

6. The acoustic Doppler current profiler calibration device based on the unmanned ship according to claim 1, 2 or 3, wherein the first high-speed camera and the second high-speed camera are of the same-model high-speed camera, a frame rate of the first high-speed camera and the second high-speed camera is 30 fps or more; a trigger line for allowing the unmanned ship to travel in and out is arranged in each field range of the first high-speed camera and the second high-speed camera, the travel-in trigger line within the field range of the first high-speed camera is superposed with a selected boundary line entering the measurement section of the unmanned ship in the test pool, the travel-out trigger line within the field range of the second high-speed camera is superposed with the selected boundary line leaving the LUS00577 measurement section of the unmanned ship in the test pool; and the sizes of the view fields of the first high-speed camera and the second high-speed camera should guarantee that the unmanned ship can uniformly operate for 30 s for more with the highest operation speed in the trigger area of each high-speed camera.

7. An acoustic Doppler current profiler calibration method based on an unmanned ship, comprising a flow velocity calibration method and a flow direction calibration method, wherein the flow velocity calibration method is as follows: the unmanned ship drives a to-be-detected Acoustic Doppler Current Profiler (ADCP) to sail back and forth along a center line, namely a track line, of the short side of a pool to measure channel flow velocity, a first high-speed camera, a second high-speed camera and total station equipment with a traceable magnitude measure average velocity of the ADCP in a measurement section, the average velocity serves as a reference standard value to be compared with a flow velocity indication value of the ADCP, and flow velocity parameter calibration is conducted; the flow direction calibration method is as follows: through the precise angle turntable with the traceable processing magnitude, an included angle between an indication direction of the ADCP and a navigation direction is adjusted, a movement track and yaw errors of the unmanned ship are plotted, a flow direction reference standard value is calculated and compared with a flow direction indication value of the ADCP, and flow direction parameter calibration is carried out.

8. The acoustic Doppler current profiler calibration device based on the unmanned ship according to claim 7, wherein the flow velocity calibration method specifically comprises the following steps:

step 1, mounting the to-be-detected ADCP to the bottom of the unmanned ship LUS00577 through the adapter flange plate, adjusting a zero-indication sign of the to-be-detected ADCP to be superposed with that of the precise angle turntable, accessing a communication cable connected with a transducer of the to-be-detected ADCP into an electronic watertight compartment of the unmanned ship, and stably hoisting the unmanned ship to the test pool;

step 2, normally starting the unmanned ship, the to-be-detected ADCP, the first high-speed camera and the second high-speed camera, and establishing time synchronizing datum among the unmanned ship, the transducer of the to-be-detected ADCP, the first high-speed camera and the second high-speed camera based on second pulse of the GPS measurement instrument;

step 3, sampling two parallel virtual straight lines which are equal in length of 180 m by the total station instrument, where one straight line is parallel to the long sides of the test pool and passes through midpoints of the short sides of the test pool to serve as a set track line that the unmanned ship travels, and the other straight line is positioned at one side of the first high-speed camera and one side of the second high- speed camera to serve as a metering standard line;

step 4, dividing the long sides of the test pool into an acceleration section, a measurement section and a deceleration section according to the length of the test pool and the highest traveling speed of the unmanned ship, determining the metering standard line sampled by the total station instrument for absolute coordinates of partition points of each section, recording absolute coordinate values of a start point and an end point of the measurement section on a set track line corresponding to the metering standard line, and inputting the absolute coordinate values into control software of a platform system of the unmanned ship for route instruction edition;

step 5, separately mounting the first high-speed camera and the second high- LUS00577 speed camera on a start position and an end position of the measurement section, where axes of optical centers of the first high-speed camera and the second high- speed camera are perpendicular to the long sides of the test pools, a connecting line of the first high-speed camera and the second high-speed camera is parallel to the long sides of the test pool, a travel-in trigger line within the field range of the first high- speed camera is superposed with a selected travel-in boundary line entering the measurement section of the unmanned ship in the test pool, a travel-out trigger line within the field range of the second high-speed camera is superposed with a selected travel-out boundary line that the unmanned ship leaves the measurement section in the test pool;

step 7, monitoring a view field area in real time through the first high-speed camera, extracting a pool surface profile line within the field range of the first high- speed camera of the test pool through characteristic difference in color and texture of a pool surface of the test pool and other background objects in the view field, and discriminating a dynamic object in the profile line through a method of making LUS00577 difference frame by frame to compare, thereby reducing wrong discrimination on a moving object outside the pool surface within the field range of the first high-speed camera;

step 9, tracing back an image that the unmanned ship reaches the travel-in trigger line recorded by the first high-speed camera, determining precise time t as that the unmanned ship firstly enters the travel-in trigger line of the first high-speed camera to serve as starting time that the unmanned ship enters the measurement section, and recording the time point as t ae in real time by the first high-speed camera while the tail of the unmanned ship passes through the travel-out trigger line of the first high- speed camera,

step 10, monitoring a view field area in real time through the first high-speed camera, extracting a pool surface profile line within the field range of the first high- speed camera of the test pool through characteristic difference in color and texture of a pool surface of the test pool and other background objects in the view field, and discriminating a dynamic object in the profile line through a method of making difference frame by frame to compare, thereby reducing wrong discrimination on a moving object outside the pool surface within the field range of the first high-speed LUS00577 camera,

step 11, recording a time point through the second high-speed camera in real time when the moving object passes through the travel-in trigger line of the second high-speed camera, adopting a particle filter algorithm to dynamically track the moving object in real time, obtaining profile characteristics of the moving object through algorithms of mean filtering, edge detection and the like, comparing the profile characteristics with pre-stored profile characteristics of the unmanned ship to judge whether the detected moving object is the travel-in unmanned ship, transferring to step 12 if yes, if no, stopping tracking and recording on the object, and repeating step 11;

step 13, precisely metering the length L of the measurement section by the total station instrument, precisely metering a distance between the travel-in trigger line and the travel-out trigger line of the first high-speed camera by the total station instrument, precisely metering a distance between the travel-in trigger line and the travel-out trigger line of the second high-speed camera by the total station instrument, and calculating the speed of passing through the measurement section, the distance L1 between the two trigger lines of the first high-speed camera and the distance L2 between the two trigger lines of the high-speed camera 9 of the unmanned ship LUS00577 through formulas 1 to 3; va ——— CD Loe T7 Le ¥, re (23 yy = La (3) 0 be i step 14, uniformly selecting m flow velocity values from the original data of the transducer of the to-be-detected ADCP to calculate an arithmetical mean as a flow velocity measurement value to be compared with the standard flow velocity value calculated in step 13 to realize calibration on flow velocity parameters, where m is greater than or equal to 30; step 15, repeating step 6 to step 14 to repeatedly measure for 10 times, thereby realizing calibration on the flow velocity parameters of the to-be-detected ADCP.

9. The acoustic Doppler current profiler calibration device based on the unmanned ship according to claim 8, wherein in step 13, if v is greater than or equal to vi and smaller than or equal to v» in step 13, v serves as the standard flow velocity value; if v is smaller than or equal to vi or v is greater than or equal to va, |v-v1 | is compared with |v-v2|; if |v-v1| is smaller than [v-v2|, v=v1 serves as the standard flow velocity value; and if [v-v1| is greater than |v-v2 |, v=v2 serves as the standard flow velocity value.

10. The acoustic Doppler current profiler calibration device based on the unmanned ship according to claim 7, 8 or 9, wherein the flow direction calibration method specifically comprises the following steps:

step 1, adjusting an included angle between the indication direction of the to-be- LUS00577 detected ADCP and the central axis of the unmanned ship to a selected angle value by the precise angle turntable;

step 2, enabling the unmanned ship to uniformly travel along the track line, setting the GPS measurement instrument to acquire position information of the unmanned ship in real time with a sampling rate of 1Hz, comparing the position information with coordinate information of the track line to calculate navigation direction deviation errors at different moments, and synthesizing the set direction value of the precise angle turntable with the navigation direction deviation value vector to serve as a standard flow direction value at the moment;

step 3, acquiring 10 flow direction indication values, at the measurement section, of the to-be-detected ADCP, and selecting the flow direction indication value at the same moment to compare and analyze the flow direction standard value, and calculating flow direction indication value errors; and step 4, within the range of 0° to 180°, uniformly selecting 7 angle values of 0°, 30°, 60°, 90°, 120°, 150° and 180°, repeating step 1 to 3 to calibrate the flow direction parameters of the transducer of the to-be-detected ADCP.