CN-115857518-B - Water surface buoy system and tracking method for assisting communication and positioning of underwater robot

CN115857518BCN 115857518 BCN115857518 BCN 115857518BCN-115857518-B

Abstract

A water surface buoy system and a tracking method for assisting in communication and positioning of an underwater robot belong to the technical field of the underwater robot. In order to solve the problem that the positioning accuracy of the existing underwater robot is affected by the static characteristics of the existing buoy, the distance between the buoy and the underwater robot becomes long and the positioning accuracy of the existing underwater robot becomes poor, the designed water surface buoy system is used as a communication relay to realize the bidirectional communication between the shore-based control end and the underwater robot by means of data information between the shore-based control end and the underwater robot, and on the other hand, the buoy obtains the relative position of the underwater robot through sonar positioning of the underwater robot and autonomously moves to correct the position deviation, so that the buoy and the underwater robot are guaranteed to be on the same line vertical to the horizontal plane. Because the buoy and the underwater robot are positioned on the same line vertical to the horizontal plane, the longitude and latitude of the buoy is the longitude and latitude of the underwater robot, and the position of the underwater robot can be accurately positioned by combining the depth position of the underwater robot.

Inventors

LI YUHAN
Ruan Ruizhi
ZHANG ZHONGTENG
YE SHIQING

Assignees

桂林电子科技大学

Dates

Publication Date: 20260505
Application Date: 20221208

Claims (8)

1. The water surface buoy system for assisting the communication and positioning of the underwater robot is characterized by comprising a buoy, a buoyancy block, a propeller, a radio frequency antenna, a positioning system, a communication cable, a telescopic rod and a sonar; The buoyancy block, the propeller, the radio frequency antenna, the positioning system and the communication cable are all arranged on the buoy, and the buoyancy block is used for providing buoyancy for the buoy; The positioning system is used for realizing positioning of the buoy; the sonar is arranged on the buoy through the telescopic rod, 3 sonar are arranged, the distances between the 3 sonar and the center O of the buoy on the water surface are recorded as OA, OB and OC, OA=OB=OC=R, and the included angles between the OA, OB and OC are 120 degrees; The buoy is internally provided with an onboard computer, and the onboard computer acquires attitude data, sensor data and image data of the underwater robot in a network mode and forwards the attitude data, sensor data and image data to a shore-based control end; the radio frequency antenna is used for realizing wireless communication between the buoy system and the shore-based control end, forwarding the gesture and image data of the underwater robot to the shore-based control end, and receiving a control instruction of the shore-based control end and forwarding the control instruction to the underwater robot.
2. The water surface buoy system for assisting communication and positioning of an underwater robot according to claim 1, wherein the onboard computer acquires attitude data, sensor data and image data of the underwater robot in an Ethernet mode and transmits the attitude data, sensor data and image data to a shore-based control end, the attitude information and the control instruction are transmitted through a TCP protocol, and the image information is transmitted through a UDP protocol.
3. A surface buoy system for assisting in the communication and positioning of an underwater robot according to claim 2, characterized in that the radio frequency antenna is adapted to communicate wirelessly by means of a wireless network bridge.
4. A surface buoy system for assisting communication and positioning of an underwater robot according to any one of claims 1 to 3, characterized in that 3 sonars are used for obtaining the respective straight line distance from the underwater robot as follows: The three sonars on the buoy are designated as sonar A, B, C, and the sonar arranged on the underwater robot is designated as sonar D; firstly, starting an internal timer by a buoy system, starting measurement of a group of data, and recording the timer for timing when the sonar A sends out the character' a The timer is recorded to count when the sonar B sends the character 'B' outwards The timer is recorded to count when the sonar C sends the character 'C' outwards ; When the sonar D receives the character 'a', the character 'A' is immediately sent, the character 'B' is immediately sent, the character 'C' is immediately sent, and when the sonar A receives the character 'A', the timer is recorded to count Recording the timer to count when the sonar B receives the character' B Recording the timer to count when sonar C receives character' C Completing measurement of a group of data; repeating the above process to realize the acquisition of the next group of data; Calculating the distance: ; Where c is the propagation velocity of the sound wave in the water.
5. A method of tracking a surface buoy system based on assistance in underwater robot communication and positioning, comprising the steps of: S1, based on the water surface buoy system for assisting the communication and positioning of the underwater robot according to any one of claims 1 to 4, a three-dimensional geometric model is built according to the spatial position relation between the buoy and the underwater robot, a geometric model corresponding to the spatial position relation between the buoy and the underwater robot is provided, a mark O point is the central position of the water surface buoy, A, B, C points are the positions of three sonar on the buoy respectively, a D 'point is the position of the underwater robot, and a D point is the vertical projection of the underwater robot D' on the water surface; 、、 The linear distances between the three sonar A, B, C on the buoy and the underwater robot D' are respectively, 、、 Respectively is 、、 Vertical projection on the water surface, line segment oa=ob=oc=r, the included angles of OA, OB and OC are 120 degrees, R is the distance between the center of the buoy and three sonar, and H is the depth of the underwater robot; s2, converting the three-dimensional geometric model into a two-dimensional geometric model representation 、、 : ; S3, the geometric model based on the spatial position relation between the buoy and the underwater robot comprises: ; Then equivalent to ; S4, tracking based on a buoy system operation process, wherein the specific process comprises the following steps of: s41, data acquisition, including depth information H of the underwater robot and distances between three sonars on the buoy and the underwater robot 、、 ; 、、 The device is obtained by three sonar communication on the buoy and sonar communication on the underwater robot; S42, filtering the data, if the measured data meets the following conditions, judging that the data is correct by the system, otherwise, judging that the data is wrong, and discarding the group of data; ; s43, filtering according to the data and outputting the filtered data The capturing of the target direction is realized by combining the following conditions; ; the successful capturing effect is that the head direction of the buoy faces to the vertical projection D of the underwater robot on the water surface; s44, target tracking: after the target is captured, namely the direction of the target is locked, the underwater robot enters a tracking link; Firstly, judging whether the tracking is successful or not, and judging the condition Whether or not the initial tracking is successful is judged, if yes, the initial tracking is successful, wherein, Tracking allowable errors preset for the system; if the preliminary tracking fails, continuing the tracking, wherein the tracking process is that the buoy moves forwards, and the data acquisition, the data filtering and the target capturing links are sequentially executed while the buoy moves forwards, so that the buoy is ensured to be in a tracking state; s45, target synchronization: After successfully tracking the underwater robot, the buoy enters a real-time position synchronization state, and the target synchronization link has two tasks, namely, when the underwater robot moves, the buoy tracks the movement of the underwater robot in real time, and the process is the same as the target tracking link, and the target synchronization link needs to be used for moving the underwater robot Secondly, the buoy sends longitude and latitude information to the ground station in real time, and then the three-dimensional space positioning can be carried out on the underwater robot by combining the depth information acquired by the depth sensor on the lower robot.
6. The method of claim 5, wherein the depth information H of the underwater robot in S41 is directly measured by a depth sensor of the underwater robot and then transmitted to the buoy system by means of cable communication on the underwater robot.
7. A method of tracking a surface buoy system based on assistance in underwater robot communication and localization as claimed in claim 5 or 6, wherein S43 effects the capture of the target direction as follows: Coarse orientation if The buoy spins 180 DEG if The buoy spins 60 ° clockwise if The float spins 60 counter-clockwise; fine tuning orientation, judging after coarse tuning orientation is completed Whether or not it is true, i.e. judge And (3) with If the difference of the two is small enough, if so, the first acquisition is successful, otherwise the first acquisition fails, if the acquisition fails, the first acquisition is compared with the second acquisition And If the size of (a) The float slowly rotates anticlockwise until The establishment is that the re-acquisition is successful; Wherein, the The capture tolerance is preset for the system.
8. The method of claim 7, wherein the forward motion of the buoy during the continuing tracking in S44 is performed at a speed determined by The difference from H determines that the greater the difference, the greater the speed of forward motion and vice versa.

Description

Water surface buoy system and tracking method for assisting communication and positioning of underwater robot Technical field: The invention belongs to the technical field of underwater robots, and particularly relates to a water surface buoy system for assisting in communication and positioning of an underwater robot and a tracking method of the underwater robot. The background technology is as follows: with the development of the marine industry, the underwater robot has very wide prospect, but the problems of communication and positioning of the underwater robot always plagues scientific researchers in the field, and the existence of the two main problems limits the wider development and application of the underwater robot. For the two problems described above, many researchers have given solutions and have been validated. Aiming at the problem of communication between the underwater robot and the land base station, the current main scheme is cable communication, shallow water wireless communication and towed buoy relay communication, and the scheme can meet the communication between the underwater robot and the land base station, but has very prominent defects. The manner in which the cables communicate is such that the range of motion of the underwater robot is limited due to the length of the cables and the underwater robot is easily entangled by the cables. The mode of shallow water wireless communication limits that the underwater robot can only move in shallow water and can not work in deep water. The towing buoy relay communication mode combines the advantages of cable communication and wireless communication, the buoy and the underwater robot are in cable communication, then the buoy serves as a relay station to realize communication between the buoy and the ground station through radio, but the cable is easily damaged in towing due to passive movement of the buoy, so that the communication scheme is temporarily stopped in an experimental stage and is not applied to industrial production. Aiming at the positioning problem of the underwater robot, as the navigation positioning system such as a GPS or Beidou and the like has no signal under water, the positioning mode of the underwater robot currently mainstream has the schemes of static buoy positioning, inertial navigation IMU positioning, visual positioning and the like, wherein the static buoy positioning is realized by using a sonar, the underwater robot can be positioned for a long time, but because the buoy is static during the detection of the sonar, the positioning precision is poor along with the distance of the buoy and the underwater robot, and the underwater robot cannot be positioned after exceeding the detection range of the sonar. The inertial navigation IMU has larger and larger error along with the increase of the positioning time, and the positioning of the inertial navigation IMU is seriously disturbed by factors such as underwater ocean currents. Visual positioning has a good effect in a clear water area, but in practical application, the acquired image is atomized due to the characteristic of seawater color, the viewing range is severely limited, and positioning cannot be realized at this time. The invention comprises the following steps: The invention aims to solve the problems that the positioning accuracy of the existing underwater robot is influenced by the static characteristics of the existing buoy, the distance between the existing underwater robot and the existing buoy is far and the existing underwater robot is poor, and the positioning of the existing underwater robot in other modes is easily limited by factors such as serious interference of ocean currents and the like or the apparent distance range. The buoy system comprises a buoy, a buoyancy block, a propeller, a radio frequency antenna, a positioning system, a communication cable, a telescopic rod and a sonar; The buoyancy block, the propeller, the radio frequency antenna, the positioning system and the communication cable are all arranged on the buoy, and the buoyancy block is used for providing buoyancy for the buoy; The positioning system is used for realizing positioning of the buoy; the sonar is arranged on the buoy through the telescopic rod, 3 sonar are arranged, the distances between the 3 sonar and the center O of the buoy on the water surface are recorded as OA, OB and OC, OA=OB=OC=R, and the included angles between the OA, OB and OC are 120 degrees; The buoy is internally provided with an onboard computer, and the onboard computer acquires attitude data, sensor data and image data of the underwater robot in a network mode and forwards the attitude data, sensor data and image data to a shore-based control end; the radio frequency antenna is used for realizing wireless communication between the buoy system and the shore-based control end, forwarding the gesture and image data of the underwater robot to the shore-based control end, and receiving a contro