Underwater robot positioning and surveying method based on multi-beam sonar

Abstract

The invention relates to an underwater robot positioning and surveying method based on a multi-beam sonar, and belongs to the technical field of underwater robots, and the method comprises the steps: building a sonar coordinate system after the underwater robot mounted with the multi-beam sonar enters a limited space; the underwater robot carries out scanning and distance measurement on the contour of the limited space through the multi-beam sonar, and the surveying contour of the limited space is expressed through coordinate values of a sonar coordinate system; performing real-time positioning on the underwater robot according to a sonar coordinate system coordinate value determined by the multi-beam sonar in real time in the limited space of the surveyed contour; when the underwater robot utilizes the shot image to carry out limited space end face survey, the image is calibrated through the real-time positioning coordinate value of the position of the shot image; and splicing the shot images of the same end face by using the calibration information to complete survey of the information of the whole end face. According to the invention, the position and attitude determination of the underwater robot in the limited space investigation process is realized, and the efficiency of limited space underwater investigation is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater robots and sonar positioning technology, and particularly relates to an underwater robot positioning and surveying method based on multi-beam sonar. Background Art

[0002] At present, underwater robots use positioning technology based on the principle of sonar ranging to locate in waters. By setting up multiple sonar transceivers underwater, a three-dimensional base station is established to receive the sonar sound waves emitted by the underwater robot. The position of the underwater robot relative to the base station is calculated by calculating the distance from the sonar transceiver to the underwater robot. The base station is connected to a ground communication satellite, and the actual position of the underwater robot is converted by the position of the base station located by the communication satellite.

[0003] It can be seen that this underwater positioning method is only applicable to the positioning of underwater robots in open waters that can be connected to satellite signals. However, when underwater robots conduct surveys in closed and limited spaces, sound waves are transmitted underwater and are interfered by echoes. The positioning signals of satellite communications are difficult to reach the waters in limited spaces, which makes it difficult for underwater robots to position themselves in limited waters and affects the survey of limited spaces. Summary of the invention

[0004] In view of the above analysis, the present invention aims to disclose an underwater robot positioning and surveying method based on multi-beam sonar to solve the problem of underwater robot positioning difficulty in surveying in confined water space.

[0005] The present invention discloses an underwater robot positioning and surveying method based on multi-beam sonar, comprising: Step S1, establishing a sonar coordinate system after the underwater robot with multi-beam sonar enters a limited space; the sonar coordinate system takes a certain ranging sonar end face of the multi-beam sonar as the origin, and marks the coordinate values ​​of each axis with the distance from each wall end face of the limited space measured by the ranging sonar in the same direction as each axis of the coordinate system; Step S2, the underwater robot scans and measures the contour of the limited space by using a multi-beam sonar, and uses the coordinate values ​​of the sonar coordinate system to represent the survey contour of the limited space; Step S3, in the limited space of the survey contour, based on the coordinate values ​​of the sonar coordinate system determined in real time by the multi-beam sonar and the contour size of the limited space, the underwater robot is positioned in real time to obtain the positioning position; Step S4: When the underwater robot uses the captured images to conduct the end face survey in a limited space, the images are calibrated by the real-time positioning coordinate values ​​of the captured image positions; the images captured on the same end face are spliced ​​using the calibration information to complete the survey of the entire end face information.

[0006] Furthermore, the multi-beam sonar is a six-beam ranging sonar mounted on the bottom of the underwater robot, which after mounting constitutes five horizontal component ranging sonars parallel to the robot body and one vertical component ranging sonar perpendicular to the robot body; Among them, the five horizontal component ranging sonars are the left front, right front, right, rear, and left ranging sonars; among them, The left front and right front ranging sonars are arranged on a plane parallel to the underwater robot body, facing the front side of the underwater robot. The ranging directions of the two sonars are symmetrical to both sides of the front-to-back central axis of the underwater robot, and are used to measure the distance from the robot to the boundary of the limited space at their respective ranging directions; The left, rear and right ranging sonars are arranged on a plane parallel to the underwater robot body, facing the left, rear and right sides of the underwater robot respectively, and the ranging directions differ by 90 degrees respectively; they are used to measure the distance from the robot to the boundary of the limited space at their respective ranging directions; The vertical component ranging sonar is perpendicular to the underwater robot body and faces the bottom of the limited space, and is used to measure the distance from the bottom of the underwater robot to the bottom of the limited space.

[0007] Further, in step S1, the sonar coordinate system established is a four-axis coordinate system, in which the measuring end surface of the rear ranging sonar is the origin of the coordinate system, and the distance measurement axes of the left, rear, and right ranging sonars and the vertical component ranging sonar are the coordinate axes of the coordinate system; Among them, the distance measurement axis of the ranging sonar is the x-axis, and the distance measurement value is the coordinate ; The distance measurement axes of the left and right ranging sonars are the positive and negative y axes, and the distance measurement values ​​are the coordinates , ; The distance measurement axis of the vertical component ranging sonar is the z axis, and the distance measurement value is the coordinate ; The sonar coordinate system coordinates of the underwater robot marked by the distance measurement values ​​of the rear, left, right ranging sonar and vertical component ranging sonar are ( , , , ).

[0008] Furthermore, the process of establishing the sonar coordinate system includes: 1) After the underwater robot enters the confined space, adjust the pitch attitude of the underwater robot so that the pitch angle of the underwater robot is the same as the pitch angle of the confined space including the cable well; ensure that the rear, left, and right ranging sonars and the vertical component ranging sonar used for coordinate value marking are perpendicular to the sound wave reflection wall of the confined space in the pitch direction; 2) Use the distance measurement values ​​of the left front and right front ranging sonars to the front wall of the limited space facing the underwater robot to adjust the orientation and posture of the underwater robot; when the distance measurement values ​​of the left front and right front ranging sonars are , When the dimensions are equal, the underwater robot is perpendicular to the front wall end face of the limited space that the front end faces in the dimension direction; 3) According to , When they are equal, the data sent back by the underwater robot's attitude sensor marks the underwater robot's orientation attitude at this time as the zero-point attitude; 4) Keep the zero-point posture unchanged, move left and right, and float up and down until the distance measurement data of the front, back, left and right are stable, avoiding the obstruction of other objects in the limited space during the distance measurement process; 5) The sonar coordinate system coordinates of the underwater robot marked by the distance measurement values ​​of the stable rear, left, right ranging sonar and vertical component ranging sonar are ( , , , ).

[0009] Furthermore, in step S2, contour survey is performed, and the process includes: 1) Determine the starting point of the contour survey; after establishing the sonar coordinate system, maintain the zero-point posture and translate the underwater robot to the first end face of the limited space, so that the rear ranging sonar is close to the first end face as the starting position of the contour survey, and record the distance measurement values ​​of the rear, left, and right ranging sonars, where the distance measurement value of the rear ranging sonar is the x-coordinate of the starting position of the contour survey The distance measurements of the left and right ranging sonars are the positive and negative y coordinates of the starting position of the profile survey. , ; 2) Conduct contour survey; maintain zero-point posture, control the underwater robot to move forward along the positive x-axis of the sonar coordinate system, and record the distance measurement values ​​of the rear, left, and right ranging sonars until the underwater robot is translated to the second end face opposite to the first end face in the limited space; 3) Establishing a contour curve; establishing a plane rectangular coordinate system, wherein the origin is the starting position of the contour survey, the horizontal axis is the x-axis of the sonar coordinate system, and the positive and negative semi-axes of the vertical axis are the positive and negative y-axes of the sonar coordinate system; marking the distance measurement values ​​of the left and right ranging sonars in the plane rectangular coordinate system to form a boundary curve of the left and right side contours of the finite space from the first end face to the second end face formed by the distance measurement values ​​of the left and right ranging sonars; on this basis, superimposing the first and second end faces to establish the survey of the finite space contour.

[0010] Furthermore, step S3 includes: 1) In the limited space of the survey contour, based on the ranging results of the multi-beam sonar, the coordinates of the underwater robot in the sonar coordinate system are determined in real time ( , , , ); 2) Measure the deflection angle B of the underwater robot in the azimuth posture relative to the zero-point posture during operation; 3) Determine the position of the robot in a limited space based on the deflection angle B and the four-axis sonar coordinate position; The robot's position in a limited space: Distance to rear wall: ; Distance to left wall: ; Distance to right wall: ; Distance from bottom: .

[0011] according to( ) Real-time positioning of underwater robots.

[0012] Furthermore, the deflection angle B is based on the distance measurement value of the left front and right front ranging sonars to the front wall of the limited space, combined with the distance measurement azimuth of the left front or right front ranging sonar and the angle between the front and rear central axis. , calculated by trigonometric function; Among them, the trigonometric function that deflects to the right is: ; ; Among them, the trigonometric function of left deflection is: ; .

[0013] Furthermore, step S4 includes: 1) When surveying the end face in a limited space, calibrate the robot’s shooting position for each image taken; The shooting position is the position of the robot in a limited space obtained based on the sonar coordinates of the shooting position and the deflection angle of the shooting position ( ); 2) Use the calibration coordinates of each image taken from the same end face ( ) for image stitching; The serial number of each image taken from the same end face; In the stitching process, each image is Determine the field of view of the image by Determine the left-right relationship and the left-right overlapping relationship of the image, through Determine the up-down relationship of the image; 3) The images taken at the same end face are stitched together to form a complete end face image, which is used to survey the entire end face information.

[0014] Furthermore, it also includes: Step S5: According to the positioning position of the underwater robot, the underwater robot is controlled to perform directional cruising along a set cruising track to survey the internal state of the entire limited space.

[0015] Furthermore, during the directional cruising process, the following steps are included: 1) Plan the cruise trajectory; The cruise trajectory is planned according to the limited space contour surveyed in step S2 and the layout of the equipment in the limited space including the cables arranged on both sides of the cable well; 2) Position the underwater robot according to the positioning process in step S3, control the positioning coordinates of the underwater robot to be consistent with the planned cruising trajectory, control the underwater robot to cruise in a directional manner, and complete the survey of the internal state of the limited space.

[0016] The present invention can achieve one of the following beneficial effects: 1. When an underwater robot moves in a confined space, the multi-beam sonar mounted on the robot measures the distance between the robot and the boundary of the confined space in real time. Combined with the survey outline of the confined space, the position of the underwater robot in the confined space is located; the position and posture of the underwater robot are determined during the confined space survey, thereby improving the efficiency of underwater survey in confined spaces.

[0017] 2. During the underwater robot survey of the end face of a limited space (such as cable well pipe hole resources), the shooting position (the position of the underwater robot) is calibrated for each image taken, and the images of the same end face are spliced ​​according to the image shooting position to complete the survey of the entire end face information.

[0018] 3. According to the contour of the surveyed limited space and the layout of the equipment in the limited space (such as cables arranged on both sides of the cable well, etc.), the cruising trajectory of the underwater robot is planned, and automatic cruising is achieved by controlling the positioning coordinates of the underwater robot to be consistent with the cruising trajectory, thereby completing the survey of the internal state of the limited space. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are only used for the purpose of illustrating specific embodiments and are not to be considered as limiting the present invention. In the entire drawings, the same reference symbols represent the same components; Figure 1 This is a flow chart of an underwater robot positioning and surveying method based on multi-beam sonar in an embodiment of the present invention; Figure 2 is a schematic diagram of a sonar coordinate system in an embodiment of the present invention; Figure 3 This is a schematic diagram of an underwater robot surveying in a cable well in an embodiment of the present invention; Figure 4 It is a schematic diagram of the survey result of the cable well contour with two ear chambers in an embodiment of the present invention; Figure 5 Schematic diagram of the relationship between the robot sonar coordinate system and the position of the robot in a limited space at a deflection angle B in an embodiment of the present invention; Figure 6 It is a schematic diagram of the image stitching process of the cable well pipe hole resource survey process in an embodiment of the present invention; Figure 7 is a schematic diagram of directional cruising in an embodiment of the present invention; Figure 8 Schematic diagram of the internal structure of a six-beam ranging sonar in an embodiment of the present invention; Fig. 9 Schematic diagram of the positional relationship between the left front ranging sonar and the right front ranging sonar in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used to illustrate the principles of the present invention together with the embodiments of the present invention.

[0021] Embodiment 1 One embodiment of the present invention discloses a method for positioning and surveying an underwater robot based on multi-beam sonar, such as Figure 1 As shown, including: Step S1, establishing a sonar coordinate system after the underwater robot with multi-beam sonar enters a limited space; the sonar coordinate system takes a certain ranging sonar end face of the multi-beam sonar as the origin, and marks the coordinate values ​​of each axis with the distance from each wall end face of the limited space measured by the ranging sonar in the same direction as each axis of the coordinate system; Step S2, the underwater robot scans and measures the contour of the limited space by using a multi-beam sonar, and uses the coordinate values ​​of the sonar coordinate system to represent the survey contour of the limited space; Step S3, in the limited space of the survey contour, based on the coordinate values ​​of the sonar coordinate system determined in real time by the multi-beam sonar and the contour size of the limited space, the underwater robot is positioned in real time to obtain the positioning position; Step S4: When the underwater robot uses the captured images to conduct the end face survey in a limited space, the images are calibrated by the real-time positioning coordinate values ​​of the captured image positions; the images captured on the same end face are spliced ​​using the calibration information to complete the survey of the entire end face information.

[0022] Specifically, the multi-beam sonar is a six-beam ranging sonar mounted on the bottom of the underwater robot, which after mounting constitutes five horizontal component ranging sonars parallel to the robot body and one vertical component ranging sonar perpendicular to the robot body; Among them, the five horizontal component ranging sonars are the left front, right front, right, rear, and left ranging sonars; among them, The left front and right front ranging sonars are arranged on a plane parallel to the underwater robot body, facing the front side of the underwater robot. The ranging directions of the two sonars are symmetrical to both sides of the front-to-back central axis of the underwater robot, and are used to measure the distance from the robot to the boundary of the limited space at their respective ranging directions; When the limited space boundary on the front side of the underwater robot is defined as the front wall, the left front and right front ranging sonars respectively measure the distance to the front wall of the limited space at their respective ranging directions; The left, rear and right ranging sonars are arranged on a plane parallel to the underwater robot body, facing the left, rear and right sides of the underwater robot respectively, and the ranging directions differ by 90 degrees respectively; they are used to measure the distance from the robot to the boundary of the limited space at their respective ranging directions; When the limited space boundary on the front side of the underwater robot is defined as the front wall, the left, rear and right ranging sonars respectively measure the distances to the left, rear and right walls of the limited space; The vertical component ranging sonar is perpendicular to the underwater robot body and faces the bottom of the limited space, and is used to measure the distance from the bottom of the underwater robot to the bottom of the limited space.

[0023] Specifically, in step S1, the sonar coordinate system established is a four-axis coordinate system, in which the measuring end surface of the rear ranging sonar is the origin of the coordinate system, and the distance measurement axes of the left, rear, and right ranging sonars and the vertical component ranging sonar are the coordinate axes of the coordinate system; Among them, the distance measurement axis of the ranging sonar is the x-axis, and the distance measurement value is the coordinate ; The distance measurement axes of the left and right ranging sonars are the positive and negative y axes, and the distance measurement values ​​are the coordinates , ; The distance measurement axis of the vertical component ranging sonar is the z axis, and the distance measurement value is the coordinate ; The sonar coordinate system coordinates of the underwater robot marked by the distance measurement values ​​of the rear, left, right ranging sonar and vertical component ranging sonar are ( , , , ).

[0024] like Figure 2 As shown in the figure, the sonar coordinate system diagram is as follows: The four-axis sonar coordinate system of this embodiment is specially designed for measuring the distance in a limited space using a multi-beam sonar, and is particularly suitable for positioning an underwater robot for surveying a regularly shaped cable well.

[0025] Figure 3 Schematic diagram of underwater robot surveying in a cable well; the cable well is usually a structure with a rectangular or similar horizontal cross-section. When the underwater robot with the six-beam ranging sonar of this embodiment mounted on the bottom is placed inside the cable well and the body is parallel to the horizontal cross-section of the cable well, the rear, left, and right ranging sonars and the vertical component ranging sonar of the six-beam ranging sonar are used to measure the distance of the rear, left, and right walls and the bottom of the cable well respectively, and the sonar coordinate system coordinates ( , , , ), thereby realizing the position marking of the underwater robot inside the cable well.

[0026] Since the ranging axis of the multi-beam sonar must be kept perpendicular to the walls of the cable well when the sonar coordinate system is used for position marking, the process of establishing the sonar coordinate system for an underwater robot surveying in a cable well that is usually set horizontally includes: 1) After the underwater robot enters the confined space, adjust the pitch attitude of the underwater robot so that the pitch angle of the underwater robot is the same as the pitch angle of the confined space including the cable well; ensure that the rear, left, and right ranging sonars and the vertical component ranging sonar used for coordinate value marking are perpendicular to the sound wave reflection wall of the confined space in the pitch direction; 2) Use the distance measurement values ​​of the left front and right front ranging sonars to the front wall of the limited space facing the underwater robot to adjust the orientation and posture of the underwater robot; when the distance measurement values ​​of the left front and right front ranging sonars are , When the dimensions are equal, the underwater robot is perpendicular to the front wall end face of the limited space that the front end faces in the dimension direction; 3) According to , When they are equal, the data sent back by the underwater robot's attitude sensor marks the underwater robot's orientation attitude at this time as the zero-point attitude; 4) Keep the zero-point posture unchanged, move left and right, and float up and down until the distance measurement data of the front, back, left and right are stable, avoiding the obstruction of other objects in the limited space during the distance measurement process; 5) The sonar coordinate system coordinates of the underwater robot marked by the distance measurement values ​​of the stable rear, left, right ranging sonar and vertical component ranging sonar are ( , , , ).

[0027] Specifically, in step S2, contour survey is performed, and the process includes: 1) Determine the starting point of the contour survey; after establishing the sonar coordinate system, maintain the zero-point posture and translate the underwater robot to the first end face of the limited space, so that the rear ranging sonar is close to the first end face as the starting position of the contour survey, and record the distance measurement values ​​of the rear, left, and right ranging sonars, where the distance measurement value of the rear ranging sonar is the x-coordinate of the starting position of the contour survey The distance measurements of the left and right ranging sonars are the positive and negative y coordinates of the starting position of the profile survey. , ; 2) Conduct contour survey; maintain zero-point posture, control the underwater robot to move forward along the positive x-axis of the sonar coordinate system, and record the distance measurement values ​​of the rear, left, and right ranging sonars until the underwater robot is translated to the second end face opposite to the first end face in the limited space; 3) Establishing a contour curve; establishing a plane rectangular coordinate system, wherein the origin is the starting position of the contour survey, the horizontal axis is the x-axis of the sonar coordinate system, and the positive and negative semi-axes of the vertical axis are the positive and negative y-axes of the sonar coordinate system; marking the distance measurement values ​​of the left and right ranging sonars in the plane rectangular coordinate system to form a boundary curve of the left and right side contours of the finite space formed by the distance measurement values ​​of the left and right ranging sonars from the first end face to the second end face; superimposing the first and second end faces on the basis to establish the survey of the finite space contour.

[0028] When conducting a contour survey of a cable well, the first end face and the second end face are the entry and exit end faces of the cable in the cable well, both of which are planes. During the survey, the boundary curves of the left and right side contours are superimposed on the straight lines of the first and second end faces to form the contour line of the cable well.

[0029] like Figure 4 Shown is the result of the cable well profile survey with two auricle chambers.

[0030] Specifically, step S3 includes: 1) In the limited space of the survey contour, based on the ranging results of the multi-beam sonar, the coordinates of the underwater robot in the sonar coordinate system are determined in real time ( , , , ); 2) Measure the deflection angle B of the underwater robot in the azimuth posture relative to the zero-point posture during operation; The deflection angle B is based on the distance measurement value of the left front and right front ranging sonars to the front wall of the limited space, combined with the distance measurement azimuth of the left front or right front ranging sonar and the angle between the front and rear central axis. , calculated by trigonometric function; Among them, the trigonometric function that deflects to the right is: ; ; Among them, the trigonometric function of left deflection is: ; .

[0031] 3) Determine the position of the robot in a limited space based on the deflection angle B and the four-axis sonar coordinate position; The robot's position in a limited space: Distance to rear wall: ; Distance to left wall: ; Distance to right wall: ; Distance from bottom: .

[0032] according to( ) Real-time positioning of underwater robots.

[0033] like Figure 5 The figure shows the relationship between the robot sonar coordinate system and the robot's position in a limited space at a deflection angle B.

[0034] Specifically, step S4 includes: 1) When surveying the end face in a limited space, calibrate the robot’s shooting position for each image taken; The shooting position is the position of the robot in a limited space obtained based on the sonar coordinates of the shooting position and the deflection angle of the shooting position ( ); 2) Based on the calibration coordinates of each image taken from the same end face ( ) for image stitching; is the serial number of each image taken at the same end face, ranging from 1 to the number of images taken at the same end face; In the stitching process, each image is Determine the field of view of the image by Determine the left-right relationship and the left-right overlapping relationship of the image, through Determine the up-down relationship of the image; 3) The images taken at the same end face are stitched together to form a complete end face image, which is used to survey the entire end face information.

[0035] like Figure 6 The figure shows a schematic diagram of the image stitching process for the cable well pipe hole resource survey process.

[0036] In order to determine the size of the wellbore hole in the image during the survey, in the preferred solution of this embodiment, a laser dot method is used to calibrate the size of the object in the image, specifically: Two parallel laser beams are emitted in parallel in the camera field of view, so that the lasers irradiate the photographed object and then reflect into the camera for imaging. The distance between the two parallel laser beams is known; then there are two laser spots in the photographed image; since the distance between the two laser spots in the image is known, the size of the object including the wellbore in the photographed image can be inferred by comparing the distance between the laser spots.

[0037] The survey solution of this embodiment also includes: Step S5: According to the positioning position of the underwater robot, the underwater robot is controlled to perform directional cruising along a set cruising track to survey the internal state of the entire limited space.

[0038] During the directional cruise, including: 1) Plan the cruise trajectory; According to the limited space outline surveyed in step S2, and the layout of the equipment in the limited space including the cables arranged on both sides of the cable well, a cruise trajectory is planned; the planned cruise trajectory includes the position to be surveyed in the limited space; 2) Position the underwater robot according to the positioning process in step S3, control the positioning coordinates of the underwater robot to be consistent with the planned cruising trajectory, control the underwater robot to cruise in a directional manner, and complete the survey of the internal state of the limited space.

[0039] like Figure 7 Shown is a schematic diagram of directional cruise.

[0040] In summary, the embodiments of the present invention can achieve the following effects: 1. When the underwater robot moves in a limited space, the multi-beam sonar mounted on the robot measures the distance between the robot and the boundary of the limited space in real time, and combines the survey contour of the limited space to locate the position of the underwater robot in the limited space; 2. During the underwater robot survey of the end face of a limited space (such as cable well pipe hole resources), the shooting position (the position of the underwater robot) is calibrated for each image taken, and the images of the same end face are spliced ​​according to the image shooting position to complete the survey of the entire end face information; 3. According to the contour of the surveyed limited space and the layout of the equipment in the limited space (such as cables arranged on both sides of the cable well, etc.), the cruising trajectory of the underwater robot is planned, and automatic cruising is achieved by controlling the positioning coordinates of the underwater robot to be consistent with the cruising trajectory, thereby completing the survey of the internal state of the limited space.

[0041] Embodiment 2 This embodiment discloses a method for positioning and surveying an underwater robot used in a cable well; wherein the cable well is a rectangular or square limited space; and the underwater robot is placed in the accumulated water in the cable well.

[0042] Specifically, the underwater robot can adopt a vector distributed multi-thruster underwater robot. By controlling the multi-thrusters of the underwater robot, the robot can have the ability to move in full space with six degrees of freedom, including forward and backward, ascending and descending, left and right translation, left and right turning, front and back pitching, and left and right flipping. It can also achieve smooth directional navigation and constant depth navigation.

[0043] Furthermore, the underwater robot is also equipped with a gyroscope, an accelerometer, a 9-axis attitude sensor, a magnetometer, a depth gauge, a water leakage gauge, an internal barometer or other functional sensors for measuring information such as the attitude, depth position and sealing state of the underwater robot.

[0044] Furthermore, the underwater robot is also equipped with a camera system and a lighting assistance system required for underwater survey; The camera system includes four sets of cameras located at the bow, left and right sides of the midship and the bottom of the underwater robot; it conducts optical surveys of the pipe hole resources, cable layout and layout status of other equipment in the cable well; The lighting assistance system includes lights corresponding to the four cameras, which are used to provide auxiliary lighting for the optical survey of the cameras. The brightness of the lights can be automatically adjusted according to the brightness of the environment to obtain clearer and more effective optical survey images.

[0045] Furthermore, the underwater robot is also fixedly mounted with a six-beam ranging sonar; The six-beam ranging sonar is fixed on the bottom of the underwater robot, and its overall shape is cylindrical; Figure 8 As shown, it includes a sonar housing 8111, a mounting plate 8112, a left front ranging sonar 8113, a right front ranging sonar 8114, a rear ranging sonar 8115, a left ranging sonar 8116, a right ranging sonar 8117 and a bottom ranging sonar 8118; the coordinate system in the figure is the body coordinate system of the underwater robot; in the body coordinate system, the length direction of the underwater robot body is the X-axis direction, the width direction is the Y-axis direction, and the height direction is the Z-axis direction; The sonar housing 8111 is a sealed housing, the mounting plate 8112 is fixed in the sonar housing 8111 and is parallel to the XY plane of the body coordinate system, the left front ranging sonar 8113, the right front ranging sonar 8114, the rear ranging sonar 8115, the left ranging sonar 8116 and the right ranging sonar 8117 are all fixed on the mounting plate 8112, and the sound axes are all located on the XY plane; The left front ranging sonar 8113 and the right front ranging sonar 8114 are fixed to the front end of the mounting plate 8112 and are symmetrically arranged on both sides of the XZ plane of the body coordinate system. The angles between the acoustic axis (the axial direction of the ranging azimuth) and the X axis are both .

[0046] The left ranging sonar 8116 and the right ranging sonar 8117 are symmetrically fixed on both sides of the mounting plate 8112, and the acoustic axes of the left ranging sonar 8116 and the right ranging sonar 8117 are perpendicular to the XZ plane of the body coordinate system; The rear ranging sonar 8115 is fixed to the rear end of the mounting plate 8112 and is located on the XZ plane of the body coordinate system; The bottom ranging sonar 8118 is fixed in the sonar housing 8111 through a mounting plate 8112 or other components, and the bottom ranging sonar 8118 is arranged perpendicular to the mounting plate 8112 .

[0047] Preferably, to avoid possible signal interference between the left front ranging sonar 8113 and the right front ranging sonar 8114. Fig. 9 As shown, the angle A is greater than or equal to the horizontal beam angles of the left front ranging sonar 3113 and the right front ranging sonar 3114. Therefore, when A is the minimum angle, it is equal to the horizontal beam angle of the sonar, which can also satisfy the requirement that the two opposite beam edges of the left front ranging sonar 3113 and the right front ranging sonar 3114 are parallel, thereby effectively avoiding signal interference and improving the reliability of measurement data.

[0048] Preferably, a calibration laser is also installed on the underwater robot; it is used to calibrate the size of the wellbore hole in the image; the calibration laser is fixed to the bow of the underwater robot, and includes two laser transmitters, and the light beam directions of the two laser transmitters are consistent with the refraction direction of the camera located at the bow.

[0049] Preferably, the line connecting the two laser emitters is perpendicular to the XZ plane of the body coordinate system. The image captured by the camera at the bow includes light spots reflected by the two laser emitters irradiating the object. Since the distance between the two laser light spots in the image is known, the size of the object including the wellbore in the captured image can be inferred by comparing the distance between the laser light spots.

[0050] In a preferred solution, the underwater robot can also be equipped with a multi-beam imaging sonar; the multi-beam imaging sonar is fixed to the bow of the underwater robot, and can achieve three-dimensional imaging of the internal state of the cable well by utilizing multiple beams, thereby further acquiring richer and more comprehensive survey information.

[0051] The multi-beam sonar-based positioning and surveying method and the effects that can be achieved by using the underwater robot described in this embodiment to perform tasks in a cable well are the same as those in Example 1. Please refer to them for details and will not be described in detail here.

[0052] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for positioning and surveying an underwater robot based on multi-beam sonar, characterized in that: include: Step S1, establishing a sonar coordinate system after the underwater robot with multi-beam sonar enters a limited space; the sonar coordinate system takes a certain ranging sonar end face of the multi-beam sonar as the origin, and marks the coordinate values ​​of each axis with the distance from each wall end face of the limited space measured by the ranging sonar in the same direction as each axis of the coordinate system; Step S2, the underwater robot scans and measures the contour of the limited space by using a multi-beam sonar, and uses the coordinate values ​​of the sonar coordinate system to represent the survey contour of the limited space; Step S3, in the limited space of the survey contour, based on the coordinate values ​​of the sonar coordinate system determined in real time by the multi-beam sonar and the contour size of the limited space, the underwater robot is positioned in real time to obtain the positioning position; Step S4: When the underwater robot uses the captured images to conduct the end face survey in a limited space, the images are calibrated by the real-time positioning coordinate values ​​of the captured image positions; the images captured on the same end face are spliced ​​using the calibration information to complete the survey of the entire end face information.

2. The underwater robot positioning and surveying method based on multi-beam sonar according to claim 1 is characterized in that: The multi-beam sonar is a six-beam ranging sonar mounted on the bottom of the underwater robot. After mounting, it forms five horizontal component ranging sonars parallel to the robot body and one vertical component ranging sonar perpendicular to the robot body; Among them, the five horizontal component ranging sonars are the left front, right front, right, rear, and left ranging sonars; among them, The left front and right front ranging sonars are arranged on a plane parallel to the underwater robot body, facing the front side of the underwater robot. The ranging directions of the two sonars are symmetrical to both sides of the front-to-back central axis of the underwater robot, and are used to measure the distance from the robot to the boundary of the limited space at their respective ranging directions; The left, rear and right ranging sonars are arranged on a plane parallel to the underwater robot body, facing the left, rear and right sides of the underwater robot respectively, and the ranging directions differ by 90 degrees respectively; they are used to measure the distance from the robot to the boundary of the limited space at their respective ranging directions; The vertical component ranging sonar is perpendicular to the underwater robot body and faces the bottom of the limited space, and is used to measure the distance from the bottom of the underwater robot to the bottom of the limited space.

3. The underwater robot positioning and surveying method based on multi-beam sonar according to claim 2 is characterized in that: In step S1, the sonar coordinate system established is a four-axis coordinate system, in which the measuring end surface of the rear ranging sonar is the origin of the coordinate system, and the distance measurement axes of the left, rear, and right ranging sonars and the vertical component ranging sonar are the coordinate axes of the coordinate system; Among them, the distance measurement axis of the ranging sonar is the x-axis, and the distance measurement value is the coordinate ; The distance measurement axes of the left and right ranging sonars are the positive and negative y axes, and the distance measurement values ​​are the coordinates , ; The distance measurement axis of the vertical component ranging sonar is the z axis, and the distance measurement value is the coordinate ; The sonar coordinate system coordinates of the underwater robot marked by the distance measurement values ​​of the rear, left, right ranging sonar and vertical component ranging sonar are ( , , , ).

4. The underwater robot positioning and surveying method based on multi-beam sonar according to claim 3 is characterized in that: The process of establishing a sonar coordinate system includes: 1) After the underwater robot enters the confined space, adjust the pitch attitude of the underwater robot so that the pitch angle of the underwater robot is the same as the pitch angle of the confined space including the cable well; ensure that the rear, left, and right ranging sonars and the vertical component ranging sonar used for coordinate value marking are perpendicular to the sound wave reflection wall of the confined space in the pitch direction; 2) Use the distance measurement values ​​of the left front and right front ranging sonars to the front wall of the limited space facing the underwater robot to adjust the orientation and posture of the underwater robot; when the distance measurement values ​​of the left front and right front ranging sonars are , When the dimensions are equal, the underwater robot is perpendicular to the front wall end face of the limited space that the front end faces in the dimension direction; 3) According to , When they are equal, the data sent back by the underwater robot's attitude sensor marks the underwater robot's orientation attitude at this time as the zero-point attitude; 4) Keep the zero-point posture unchanged, move left and right, and float up and down until the distance measurement data of the front, back, left and right are stable, avoiding the obstruction of other objects in the limited space during the distance measurement process; 5) The sonar coordinate system coordinates of the underwater robot marked by the distance measurement values ​​of the stable rear, left, right ranging sonar and vertical component ranging sonar are ( , , , ).

5. The underwater robot positioning and surveying method based on multi-beam sonar according to claim 4 is characterized in that: In step S2, contour survey is performed, and the process includes: 1) Determine the starting point of the contour survey; after establishing the sonar coordinate system, maintain the zero-point posture and translate the underwater robot to the first end face of the limited space, so that the rear ranging sonar is close to the first end face as the starting position of the contour survey, and record the distance measurement values ​​of the rear, left, and right ranging sonars, where the distance measurement value of the rear ranging sonar is the x-coordinate of the starting position of the contour survey The distance measurements of the left and right ranging sonars are the positive and negative y coordinates of the starting position of the profile survey. , ; 2) Conduct contour survey; maintain zero-point posture, control the underwater robot to move forward along the positive x-axis of the sonar coordinate system, and record the distance measurement values ​​of the rear, left, and right ranging sonars until the underwater robot is translated to the second end face opposite to the first end face in the limited space; 3) Establishing a contour curve; establishing a plane rectangular coordinate system, wherein the origin is the starting position of the contour survey, the horizontal axis is the x-axis of the sonar coordinate system, and the positive and negative semi-axes of the vertical axis are the positive and negative y-axes of the sonar coordinate system; marking the distance measurement values ​​of the left and right ranging sonars in the plane rectangular coordinate system to form a boundary curve of the left and right side contours of the finite space from the first end face to the second end face formed by the distance measurement values ​​of the left and right ranging sonars; on this basis, superimposing the first and second end faces to establish the survey of the finite space contour.

6. The underwater robot positioning and surveying method based on multi-beam sonar according to claim 5 is characterized in that: Step S3 includes: 1) In the limited space of the survey contour, the coordinates of the underwater robot in the sonar coordinate system are determined in real time based on the ranging results of the multi-beam sonar ( , , , ); 2) Measure the deflection angle B of the underwater robot in the azimuth posture relative to the zero-point posture during operation; 3) Determine the position of the robot in a limited space based on the deflection angle B and the four-axis sonar coordinate position; The robot's position in a limited space: Distance to rear wall: ; Distance to left wall: ; Distance to right wall: ; Distance from bottom: ; according to( ) Real-time positioning of underwater robots.

7. The underwater robot positioning and surveying method based on multi-beam sonar according to claim 6 is characterized in that: The deflection angle B is based on the distance measurement value of the left front and right front ranging sonars to the front wall of the limited space, combined with the distance measurement azimuth of the left front or right front ranging sonar and the angle between the front and rear central axis. , calculated by trigonometric function; Among them, the trigonometric function that deflects to the right is: ； ； Among them, the trigonometric function of left deflection is: ； 。 8. The underwater robot positioning and surveying method based on multi-beam sonar according to claim 6, characterized in that: Step S4 includes: 1) When surveying the end face in a limited space, calibrate the robot’s shooting position for each image taken; The shooting position is the position of the robot in a limited space obtained based on the sonar coordinates of the shooting position and the deflection angle of the shooting position ( ); 2) Use the calibration coordinates of each image taken from the same end face ( ) for image stitching; The serial number of each image taken from the same end face; In the stitching process, each image is Determine the field of view of the image by Determine the left-right relationship and the left-right overlapping relationship of the image, through Determine the up-down relationship of the image; 3) The images taken at the same end face are stitched together to form a complete end face image, which is used to survey the entire end face information.

9. The underwater robot positioning and surveying method based on multi-beam sonar according to claim 6, characterized in that: Also includes: Step S5: According to the positioning position of the underwater robot, the underwater robot is controlled to perform directional cruising along a set cruising track to survey the internal state of the entire limited space.

10. The underwater robot positioning and surveying method based on multi-beam sonar according to claim 9, characterized in that: During the directional cruise, including: 1) Plan the cruise trajectory; The cruise trajectory is planned according to the limited space contour surveyed in step S2 and the layout of the equipment in the limited space including the cables arranged on both sides of the cable well; 2) Position the underwater robot according to the positioning process in step S3, control the positioning coordinates of the underwater robot to be consistent with the planned cruising trajectory, control the underwater robot to cruise in a directional manner, and complete the survey of the internal state of the limited space.

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