An underwater robot target docking system and method based on acousto-optic guidance

Abstract

The application mainly relates to an underwater robot target docking system and method based on sound-light guidance, and aims to solve the problems of laying and recovering of in-situ calibration of a sensor of an existing ocean observation network. The application patent comprises a sound-light guidance system, a self-contained standard device, an ROV and the like. After the ROV lays the self-contained standard device, the ROV leaves, the interference of the ROV on the self-contained standard device is reduced, and then the ROV is recovered through the sound-light guidance system, so that the in-situ calibration of the ocean observation network is realized.

Description

Technical Field

[0001] This invention mainly relates to the field of underwater target positioning and recovery, and in particular to an underwater robot target docking system and method based on acoustic-optical guidance. Background Technology

[0002] The ocean observation network integrates disciplines such as physical oceanography, marine chemistry, and marine geophysics to address the need for high-resolution and real-time acquisition of ocean observation data in deep-sea and extreme environments. Since the network's sensors are permanently stationary in the deep sea, making periodic calibration difficult, an underwater robot (ROV) is required to carry a self-contained standard to calibrate the sensors. In practical applications, to prevent the ROV from interfering with the measurements of the self-contained standard, the ROV must move a distance away after deploying the standard and retrieve it only after data acquisition.

[0003] In existing technologies, the retrieval of standard devices is generally carried out by using ROVs equipped with robotic arms for capture and retrieval. However, most ROVs use acoustic devices for searching, direction finding, and distance measurement. At close range, the acoustic signal data update frequency is low, resulting in poor stability and accuracy during docking, and the position of the standard device cannot be obtained in real time.

[0004] To date, there is no complete in-situ calibration device for marine observation network sensors in China, which seriously affects the accuracy of marine observation network sensors. To address this, we propose an underwater robot target docking system and method based on acoustic-optical guidance. Summary of the Invention

[0005] To address the shortcomings of the existing technology, this invention provides an underwater robot target docking system and method based on acoustic-optical guidance, thereby enabling the deployment and recovery of targets by ROVs in multiple scenarios using acoustic-optical guidance and acoustic communication.

[0006] The technical solution adopted in this invention is as follows:

[0007] An underwater robot target docking system based on acoustic-optical guidance includes an ROV (Remotely Operated Vehicle), a self-contained standard, and an acoustic-optical guidance device. The ROV has full attitude control and is equipped with a mechanical gripper and a light source for grasping the self-contained standard and for illumination. The self-contained standard includes multiple standard hydrophones, standard thermometers, standard magnetic sensors, a non-magnetic electronic chamber, and internal electronic systems. The acoustic-optical guidance device includes an ultra-short baseline sonar, an acoustic interrogator, a blue-green light beacon, and an underwater camera. The ultra-short baseline sonar, acoustic interrogator, and blue-green light beacon are mounted on the self-contained standard; another set of acoustic interrogators is positioned above the ROV, and the underwater camera is positioned directly in front of the ROV.

[0008] This invention also discloses an underwater robot target docking method based on acoustic-optical guidance, comprising the following steps:

[0009] Step 1: Deploy the entire system in shallow water. The ROV and the self-contained standard establish a handshake communication link. The power of the transceiver is automatically configured based on the received signal amplitude. Then, by transmitting and receiving commands through the first and second transceiver transceivers and the USMR sonar, direction finding and ranging are performed according to the entire acoustic-optical guidance process. If the ranging result is less than the distance threshold three consecutive times, the blue-green light beacon is activated, entering a parallel acoustic and optical guidance state. If the tank test results are normal, a command is sent via the acoustic interrogator to disable the acoustic-optical guidance function of the USMR sonar, entering underwater acoustic communication mode.

[0010] Step 2: After the ROV sinks to the bottom, due to the large change in hydrostatic pressure, the acoustic and optical guidance system needs to be tested as described above before deploying the self-contained standard.

[0011] Step 3: After placing the self-capacitive standard near the sensor to be calibrated, the ROV moves away from the area.

[0012] Step 4: During the in-situ calibration process, or after the calibration data collection is completed, the first transceiver and the second transceiver perform handshake communication to establish a deep-sea acoustic communication link, and automatically configure the power level of the power amplifier and the amplification factor of the receiver end according to the amplitude of the received signal.

[0013] Step 5: If the self-contained standard needs to be retrieved, the second transceiver analyzer sends an acoustic guidance command. After receiving the command, the first transceiver analyzer enters the acoustic guidance state.

[0014] Step Six: Using the US.S. sonar as a reference, measure the bearing of the second transceiver omnidirectional transducer relative to the US.S. sonar. Acoustic positioning can be decomposed into two sub-modules: direction finding and range finding. Direction finding is achieved by the US.S. sonar, and the direction finding results are sent to the second transceiver omnidirectional transducer via the first transceiver omnidirectional transducer. Range finding is achieved by the first transceiver omnidirectional transducer, using the acoustic propagation time of the interrogation signal and the response signal, and a fixed time delay to estimate the slant range. After receiving the direction, slant range, and US.S. sonar heading information, the mother ship's ship-based display and control console calculates the ROV's bearing relative to the self-contained standard. ROV operators adjust the ROV's heading, speed, and depth based on the acoustic positioning results, gradually approaching the self-contained standard.

[0015] Step 7: If the distance between the second transceiver rectifier and the first transceiver rectifier on the ROV is less than the distance threshold for three consecutive times, turn on the blue-green light beacon on the self-contained standard and enter the acoustic and optical parallel guidance state.

[0016] Step 8: When the ROV approaches the self-contained standard, it sends a command through the second transceiver phasor to turn off the acoustic-optical guidance function of the self-contained standard and enter the underwater acoustic communication state. At the same time, the robot arm on the ROV retrieves the self-contained standard.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. The system has the function of self-testing and adjusting the gain of the signal in communication, which can make the signal-to-noise ratio of the received signal at a good level.

[0019] 2. Through the acoustic interrogator, the ROV and the self-contained standard communicate with each other, and the position information of the ROV relative to the self-contained standard can be fed back to the operator in real time.

[0020] 3. Acoustic guidance is used at long distances, leveraging the high precision of ultra-short baseline sonar to enable the ROV to quickly locate the self-contained standard. At close range, combined acoustic and optical guidance facilitates precise grasping and retrieval by the ROV's robotic arm. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the ROV deployment of the self-contained standard device of the present invention.

[0022] Figure 2 This is a schematic diagram of the self-contained standard of the present invention.

[0023] Figure 3 for Figure 2 The main view.

[0024] Figure 4 This is a schematic diagram of the ROV of the present invention.

[0025] Figure 5 This is a schematic diagram of the acoustic-optical guidance system of the present invention.

[0026] The components include: 1. Main control station; 2. Watertight cable; 3. Observation network junction box; 4. Observation network sensor; 401. Sensor cable; 5. Self-contained standard; 501. Standard thermometer; 502. Fixed crossbeam; 503. Standard hydrophone; 504. Standard magnetic sensor; 505. Grasping bracket; 506. Non-magnetic electronic compartment and internal electronic system; 507. Base; 6. Acoustic-optical guidance system; 601. First transceiver phasor; 602. Ultra-short baseline sonar; 603. Acoustic-optical guidance device mounting plate; 604. Blue-green light beacon; 605. Underwater camera; 606. Second transceiver phasor; 7. Mother ship; 8. ROV; 801. ROV cable; 802. Manipulator; 803. Searchlight; 804. Attitude controller. Detailed Implementation

[0027] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0028] like Figures 1-5 As shown, the marine observation network includes a main control station 1, watertight cables 2, an observation network junction box 3, and observation network sensors 4 for collecting seabed data. This invention is an underwater robot target docking system based on acoustic-optical guidance, including a mother ship 6 and an ROV 8, used for deploying and recovering self-contained standard devices 5. An underwater camera 605 and a robotic arm 802 are mounted at the front of the ROV 8, and searchlights 803 are installed on both sides; the ROV cable 801 connects it to the mother ship 6 from above.

[0029] like Figures 2-3 As shown, the self-contained standard 5 includes a standard thermometer 501, a fixed crossbar 502, a standard hydrophone 503, a standard magnetic sensor 504, a gripping bracket 505, a non-magnetic electronic chamber and internal electronic system 506, and a base 507. The non-magnetic electronic chamber and internal electronic system 506 are located below the self-contained standard 5 and connected to the base 507. The gripping bracket 505 and the fixed crossbar 502 are arranged around the non-magnetic electronic chamber and internal electronic system 506. The standard thermometer 501, the standard hydrophone 503, and the standard magnetic sensor 504 are arranged above the non-magnetic electronic chamber and internal electronic system 506.

[0030] Figures 2-4 As shown, the acoustic-optical guidance device 6 includes a first transceiver 601, an ultra-short baseline sonar 602, an acoustic-optical guidance device mounting plate 603, blue-green light beacons 604, an underwater camera 605, and a second transceiver 606. The first transceiver 601 and the ultra-short baseline sonar 602 are mounted on top of the self-contained standard device 5 via the acoustic-optical guidance device mounting plate 603. The ultra-short baseline sonar 602 are evenly distributed in a cross shape. The blue-green light beacons 604 are located below the acoustic-optical guidance device mounting plate 603, and there are 15 blue-green light beacons 604 in total, arranged in a triangular pattern, with 5 on each side. The underwater camera 605 and the second transceiver 606 are mounted directly in front of the ROV8. The first transceiver 601, the ultra-short baseline sonar 602, the acoustic-optical guidance device mounting plate 603, and the second transceiver 606 constitute the acoustic guidance system; the blue-green light beacon 604 and the underwater camera 605 constitute the optical guidance system.

[0031] A target docking method for underwater robots based on acoustic-optical guidance, such as Figure 5 As shown, it includes the following steps:

[0032] Step 1: The entire system is first placed in shallow water. ROV8 and self-contained standard device 5 establish a handshake communication link. The power of the transceiver phasor is automatically configured based on the received signal amplitude. Then, commands are transmitted and received through the first transceiver phasor 601, the second transceiver phasor 606, and the ultra-short baseline sonar 602. Direction finding and ranging are performed according to the entire acoustic-optical guidance process. If the ranging result is less than the distance threshold three times consecutively, the blue-green light beacon 604 is activated, entering the acoustic and optical parallel guidance state. If the shallow water test results are normal, a command is sent through the second transceiver phasor 606 to disable the acoustic-optical guidance function on the self-contained standard device 5, entering the underwater acoustic communication state.

[0033] Step 2: After the ROV8 sinks to the bottom, due to the large change in hydrostatic pressure, the acoustic and optical guidance system needs to be tested as described above before deploying the self-contained standard 5.

[0034] Step 3: After placing the self-capacitive standard 5 near the sensor to be calibrated, the ROV8 moves away from the area.

[0035] Step 4: During the in-situ calibration process, or after the calibration data collection is completed, the first transceiver 601 and the second transceiver 606 perform handshake communication to establish a deep-sea acoustic communication link, and automatically configure the power level of the power amplifier and the amplification factor of the receiver end according to the amplitude of the received signal.

[0036] Step 5: If the self-contained standard 5 needs to be retrieved, the second transceiver 606 sends an acoustic guidance command. After receiving the command, the first transceiver 601 enters the acoustic guidance state.

[0037] Step Six: Using the US. short baseline sonar 602 as a reference, measure the bearing of the second transceiver 606 relative to the US. short baseline sonar 602. Acoustic positioning can be decomposed into two sub-modules: direction finding and range finding. Direction finding is achieved by the US. short baseline sonar 602, and the direction finding result is sent to the second transceiver 606 through the first transceiver 601. Range finding is achieved by the first transceiver 601, and the slant range is estimated using the acoustic propagation time and fixed time delay of the interrogation signal and the response signal. After receiving the direction, slant range, and US. short baseline sonar 602 heading information, the ship-based display and control console of the mother ship 7 calculates the bearing of the ROV8 relative to the self-contained standard 5. The ROV8 operator adjusts the ROV8's heading, speed, and depth according to the acoustic positioning results, gradually approaching the self-contained standard.

[0038] Step 7: If the distance between the second transceiver 606 and the first transceiver 601 on ROV8 is less than the distance threshold for three consecutive times, turn on the blue-green light beacon 604 on the self-contained standard 5 and enter the acoustic and optical parallel guidance state.

[0039] Step 8: When the ROV8 approaches the self-contained standard 5, it sends a command through the second transceiver 606 to turn off the acoustic and optical guidance function of the self-contained standard and enter the underwater acoustic communication state. At the same time, the robot arm 802 on the ROV8 retrieves the self-contained standard 5.

[0040] The system combines acoustic and optical guidance with underwater acoustic communication to enable ROV deployment and retrieval in multiple scenarios. The system is simple, easy to operate, has a high success rate of docking, and facilitates rapid ROV deployment and retrieval.

[0041] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. An underwater robot target docking system based on acoustic-optical guidance, characterized in that: Mother ship (7); ROV (8), used to deploy and retrieve self-contained standard (5), with an underwater camera (605) and a manipulator (802) at the front of the ROV (8) and searchlights (803) on both sides; ROV cable (801) connected to the mother ship (7); sound and light guidance device (6), used to guide the ROV (8) to approach the self-contained standard; The self-contained standard (5) includes a standard thermometer (501), a fixed crossbar (502), a standard hydrophone (503), a standard magnetic sensor (504), a gripping bracket (505), a non-magnetic electronic chamber and internal electronic system (506), and a base (507). The non-magnetic electronic chamber and internal electronic system (506) are located below the self-contained standard (5) and connected to the base (507). The gripping bracket (505) and the fixed crossbar (502) are arranged around the non-magnetic electronic chamber and internal electronic system (506). The standard thermometer (501), the standard hydrophone (503), and the standard magnetic sensor (504) are arranged above the non-magnetic electronic chamber and internal electronic system (506). The aforementioned acoustic-optical guidance device (6) includes a first transceiver phasor (601), an ultra-short baseline sonar (602), an acoustic-optical guidance device mounting plate (603), a blue-green light beacon (604), an underwater camera (605), and a second transceiver phasor (606). The first transceiver phasor (601) and the ultra-short baseline sonar (602) are mounted on top of the self-contained standard (5) via the acoustic-optical guidance device mounting plate (603). The ultra-short baseline sonar (602) is evenly distributed in a cross shape. The blue-green light beacon (604) is located below the acoustic-optical guidance device mounting plate (603). There are 15 blue-green light beacons (604) in total, arranged in a triangular pattern, with 5 on each side. The underwater camera (605) and the second transceiver phasor (606) are mounted directly in front of the ROV (8).

2. The underwater robot target docking system based on acoustic-optical guidance as described in claim 1, characterized in that: The first transceiver phasor (601), the ultra-short baseline sonar (602), the acoustic-optical guidance device mounting plate (603), and the second transceiver phasor (606) constitute the acoustic guidance system; the blue-green light beacon (604) and the underwater camera (605) constitute the optical guidance system.

3. A method for underwater robot target docking based on acoustic-optical guidance, employing the underwater robot target docking system described in claim 1, characterized in that, Includes the following steps: Step 1: The entire system is first placed in shallow water. The ROV (8) and the self-contained standard (5) establish an underwater acoustic communication link by handshaking with each other. The power of the transceiver is automatically configured according to the amplitude of the received signal. Then, commands are sent and received through the first transceiver (601), the second transceiver (606), and the ultra-short baseline sonar (602). Direction finding and ranging are performed according to the entire process of acoustic-optical guidance. If the ranging result is less than the distance threshold for three consecutive times, the blue-green light beacon (604) is turned on, and the acoustic and optical parallel guidance state is entered. If the shallow water test result is normal, the second transceiver (606) sends a command to turn off the acoustic-optical guidance function on the self-contained standard (5) and enter the underwater acoustic communication state. Step 2: After the ROV (8) sinks to the bottom, due to the large change in hydrostatic pressure, the status of the acoustic and optical guidance system needs to be tested as above before the ROV (8) is deployed with the self-contained standard (5). Step 3: After placing the self-capacitive standard (5) near the sensor to be calibrated, the ROV (8) moves away from the area; Step 4: During the in-situ calibration process, or after the calibration data collection is completed, the first transceiver jacking transducer (601) and the second transceiver jacking transducer (606) perform handshake communication to establish a deep-sea acoustic communication link, and automatically configure the power level of the power amplifier and the amplification factor of the receiving end according to the amplitude of the received signal. Step 5: If the self-contained standard (5) is to be retrieved, the second transceiver phasor (606) sends an acoustic guidance command. After receiving the command, the first transceiver phasor (601) enters the acoustic guidance state. Step 6: Using the ultra-short baseline sonar (602) as a reference, measure the bearing of the second transceiver phasor (606) relative to the ultra-short baseline sonar (602). Acoustic positioning is decomposed into two sub-modules: direction finding and range finding. Direction finding is achieved by the ultra-short baseline sonar (602), and the direction finding result is sent to the second transceiver phasor (606) through the first transceiver phasor (601). Range finding is achieved by the first transceiver phasor (601), and the slant range is estimated by using the acoustic propagation time and fixed time delay of the interrogation signal and the response signal. After receiving the direction, slant range, and heading information, the ship-based display and control console of the mother ship (7) calculates the bearing of the ROV (8) relative to the self-contained standard (5). The ROV operator adjusts the heading, speed, and depth of the ROV (8) according to the acoustic positioning result, and gradually approaches the self-contained standard. Step 7: If the distance between the second transceiver phasor (606) and the first transceiver phasor (601) on the ROV (8) is less than the distance threshold for three consecutive times, turn on the blue-green light beacon (604) on the self-contained standard (5) and enter the acoustic and optical parallel guidance state; Step 8: When the ROV (8) approaches the self-contained standard (5), it sends a command through the second transceiver phasor (606) to turn off the acoustic and optical guidance function of the self-contained standard and enter the underwater acoustic communication state. At the same time, the manipulator (802) on the ROV (8) retrieves the self-contained standard (5).

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