CN-122018515-A - Underwater robot control method and system for cable centering and underwater robot

CN122018515ACN 122018515 ACN122018515 ACN 122018515ACN-122018515-A

Abstract

The application discloses a cable-centering-oriented underwater robot control method, a cable-centering-oriented underwater robot control system and an underwater robot, and relates to the technical field of robots. And calculating the relative pose and the relative distance between the underwater robot and the target cable according to the pixel point coordinates of the plurality of cable feature points in the target image frame and the operation data of the underwater robot. And adjusting the rotating speeds of the plurality of propellers by combining the relative pose and the relative distance, and controlling the operation of the underwater robot according to the adjusted rotating speeds of the plurality of propellers. Wherein the adjusted rotational speeds of the plurality of thrusters are used to position the target cable in a preset intermediate region of the acquisition field of view of the camera sensor. According to the embodiment of the application, the accurate positioning of the submarine cable can be realized, so that the stability of the operation of the underwater robot is ensured.

Inventors

QIAO JIANAN
YU JIANCHENG
JU XIAOLONG
ZHAO BAODE
ZHAO YANLING
CHEN KEYU
LIU RUNNAN
WANG ZHENYU
LI TIANGUANG

Assignees

中国科学院沈阳自动化研究所

Dates

Publication Date: 20260512
Application Date: 20260415

Claims (10)

1. A cable-centering-oriented underwater robot control method, characterized by being applied to an underwater robot including a camera sensor and a plurality of thrusters, the method comprising: Acquiring a target image frame by using the camera sensor, and determining pixel point coordinates of a plurality of cable characteristic points in the target image frame, wherein the plurality of cable characteristic points are determined based on an initial image frame, and the initial image frame and the target image frame comprise a target cable; Calculating the relative pose and the relative distance between the underwater robot and the target cable according to the pixel point coordinates of the plurality of cable feature points in the target image frame and the operation data of the underwater robot; And adjusting the rotating speeds of the plurality of propellers according to the relative pose and the relative distance, and controlling the operation of the underwater robot according to the adjusted rotating speeds of the plurality of propellers, wherein the adjusted rotating speeds of the plurality of propellers are used for enabling the target cable to be located in a preset middle area of an acquisition view field of the camera sensor.
2. The method of claim 1, wherein the plurality of thrusters comprises a horizontal thruster and a stern thruster, the adjusting the rotational speed of the plurality of thrusters in combination with the relative pose and the relative distance comprising: calculating running direction errors, transverse errors and heading errors of the underwater robot according to the relative pose and the relative distance, wherein the transverse errors are errors which are perpendicular to the running direction of the underwater robot and correspond to the directions which are positioned on the same horizontal plane; determining an expected thrust, an expected transverse thrust and an expected heading moment of the underwater robot according to the running direction error, the transverse error and the heading error; Determining a target thrust of the horizontal propeller and a target thrust of the stern propeller according to the running direction expected thrust, the transverse expected thrust and the bow expected moment; and adjusting the rotating speed of the horizontal propeller according to the target thrust of the horizontal propeller, and adjusting the rotating speed of the stern-directional propeller according to the target thrust of the stern-directional propeller.
3. The method of claim 2, wherein the determining the desired thrust, the desired lateral thrust, and the desired moment of heading for the underwater robot based on the travel direction error, the lateral error, and the heading error comprises: Calculating a target ocean current resistance according to the running speed of the underwater robot and the rotating speeds of the plurality of propellers; Determining thrust compensation amounts of the plurality of propellers according to the target ocean current resistance; and determining the expected thrust in the running direction, the expected transverse thrust and the expected heading moment according to the thrust compensation amounts of the plurality of propellers, the running direction error, the transverse error and the heading error.
4. A method according to claim 3, wherein said determining the target thrust of the horizontal propeller and the target thrust of the stern propeller from the running direction desired thrust, the lateral desired thrust and the bow desired torque comprises: mapping the current thrust of the plurality of propellers to a geodetic coordinate system to obtain a target mapping matrix; And determining the target thrust of the horizontal propeller and the target thrust of the stern-direction propeller according to the pseudo-inverse matrix of the target mapping matrix, the running direction expected thrust, the transverse expected thrust and the bow expected moment.
5. The method of any of claims 1-4, wherein the calculating the relative pose and relative distance between the underwater robot and the target cable based on pixel point coordinates of the plurality of cable feature points in the target image frame and operational data of the underwater robot comprises: Determining a projection length change rate according to the projection length of the target cable in a historical image frame and the projection length of the target cable in the target image frame, wherein the historical image frame is an adjacent image frame positioned in front of the target image frame; Calculating the relative distance between the underwater robot and the target cable according to the projection length change rate, the horizontal displacement of the underwater robot in a target period and the pitch angle change, wherein the target period is a time interval from the acquisition time of the historical image frames to the acquisition time of the target image frames; Calculating body coordinates of the plurality of cable feature points under a body coordinate system according to pixel point coordinates of the plurality of cable feature points in the target image frame and the relative distance; Calculating a relative yaw angle between the underwater robot and the target cable according to an inclination angle of the target cable relative to a fore-aft direction and a yaw angle of the underwater robot; and obtaining the relative pose between the underwater robot and the target cable according to the body coordinates of the cable characteristic points in the body coordinate system and the relative deflection angle.
6. The method of any of claims 1-4, wherein the determining pixel point coordinates of a plurality of cable feature points in the target image frame comprises: Preprocessing the target image frame, and forming a cable pixel point set from all pixel points belonging to the target cable in the preprocessed target image frame according to an edge detection algorithm; determining an axis pixel point set of the target cable from the cable pixel point set according to a straight line fitting algorithm; And for each cable characteristic point, determining pixel point coordinates corresponding to the cable characteristic point from the axis pixel point set according to a characteristic point tracking algorithm.
7. The method of claim 6, wherein the preprocessing the target image frame comprises: Performing enhancement processing on the contrast of the target image frame according to an image enhancement algorithm; And denoising the target image frame subjected to enhancement processing according to an image filtering algorithm, wherein the denoising processing is used for retaining edge details of a target cable in the target image frame.
8. The method of claim 1, wherein in the case where the underwater robot further comprises a doppler velocimeter and the plurality of thrusters further comprises vertical thrusters, the method further comprises: determining the height from the bottom of the underwater robot through the Doppler velocimeter; taking the difference value between the bottom height and the target height as a vertical error; And determining the target thrust of the vertical propeller according to the vertical error, and adjusting the rotating speed of the vertical propeller according to the target thrust of the vertical propeller.
9. An underwater robot control system is characterized by comprising a cable identification module, an information calculation module and a rotation speed adjustment module; The cable identification module is used for receiving a target image frame acquired by a camera sensor and determining pixel point coordinates of a plurality of cable characteristic points in the target image frame, wherein the plurality of cable characteristic points are determined based on an initial image frame, and the initial image frame and the target image frame comprise a target cable; the information calculation module is used for calculating the relative pose and the relative distance between the underwater robot and the target cable according to the pixel point coordinates of the plurality of cable characteristic points in the target image frame and the operation data of the underwater robot; the rotating speed adjusting module is used for adjusting the rotating speeds of the plurality of propellers by combining the relative pose and the relative distance, wherein the adjusted rotating speeds of the plurality of propellers are used for controlling the running of the underwater robot, so that the target cable is positioned in a preset middle area of an acquisition view field of the camera sensor.
10. An underwater robot comprising a camera sensor, a plurality of thrusters, and the underwater robot control system of claim 9.

Description

Underwater robot control method and system for cable centering and underwater robot Technical Field The application relates to the technical field of robots, in particular to a cable-centering-oriented underwater robot control method and system and an underwater robot. Background With the continuous development of submarine network construction, the underwater robot needs to carry out the handling operations such as inspection, laying, maintenance and the like on submarine cables. In order for the underwater robot to operate properly, the underwater robot needs to position the subsea cable to ensure that the underwater robot is able to align and act on the subsea cable. Therefore, how to realize the accurate positioning of the submarine cable, thereby guaranteeing the stability of the operation of the underwater robot, becomes a problem to be solved urgently. Disclosure of Invention In view of the above, the embodiment of the application provides a cable centering-oriented underwater robot control method and system and an underwater robot, which can realize accurate positioning of a submarine cable, ensure the stability of the operation of the underwater robot and further improve the operation efficiency of the underwater robot. In a first aspect, the present application provides a cable-centering-oriented underwater robot control method, including: Acquiring a target image frame by using a camera sensor, and determining pixel point coordinates of a plurality of cable characteristic points in the target image frame, wherein the plurality of cable characteristic points are determined based on an initial image frame, and the initial image frame and the target image frame comprise a target cable; Calculating the relative pose and the relative distance between the underwater robot and the target cable according to the pixel point coordinates of the plurality of cable feature points in the target image frame and the operation data of the underwater robot; And adjusting the rotating speeds of the plurality of propellers according to the relative pose and the relative distance, and controlling the operation of the underwater robot according to the adjusted rotating speeds of the plurality of propellers, wherein the adjusted rotating speeds of the plurality of propellers are used for enabling the target cable to be located in a preset middle area of an acquisition view field of the camera sensor. In a second aspect, the application provides an underwater robot control system, which comprises a cable identification module, an information calculation module and a rotation speed adjustment module; The cable identification module is used for receiving target image frames acquired by the camera sensor and determining pixel point coordinates of a plurality of cable characteristic points in the target image frames, wherein the cable characteristic points are determined based on initial image frames, and the initial image frames and the target image frames comprise target cables; The information calculation module is used for calculating the relative pose and the relative distance between the underwater robot and the target cable according to the pixel point coordinates of the plurality of cable characteristic points in the target image frame and the operation data of the underwater robot; The rotating speed adjusting module is used for adjusting the rotating speeds of the plurality of propellers by combining the relative pose and the relative distance, wherein the adjusted rotating speeds of the plurality of propellers are used for controlling the operation of the underwater robot, so that the target cable is positioned in a preset middle area of the acquisition view field of the camera sensor. In a third aspect, the present application provides an underwater robot comprising a camera sensor, a plurality of thrusters and an underwater robot control system as described above. By means of the technical scheme, the underwater robot control method and system for cable centering and the underwater robot provided by the embodiment of the application are used for extracting pixel point coordinates corresponding to a plurality of cable characteristic points through the target image frames acquired by the camera sensor, and accurately calculating the relative pose and the relative distance of the cable to be tested by combining the operation data of the underwater robot. And then dynamically adjusting the rotation speed of the multiple propellers through the relative pose and the relative distance to control the robot to run, so as to ensure that the target cable is kept centered in the acquisition view of the camera sensor. Therefore, stable gesture and position compensation can be provided for the underwater robot through accurate regulation and control of the rotating speed of the propeller, sufficient visual adjustment allowance is reserved, the condition that the target cable moves out of the visual field range due to small d