CN118753476A - Underwater robot and control method for autonomously monitoring aquatic product status and growth environment - Google Patents

Abstract

The present invention belongs to the technical field of underwater robots, and provides an underwater robot and control method for autonomously monitoring the state and growth environment of aquatic products, including: an underwater robot structure, a propeller, a waterproof sealed compartment for equipment, a waterproof sealed compartment for power supply, and a central control module; the underwater robot structure is used to fix the propeller, the waterproof sealed compartment for equipment, and the waterproof sealed compartment for power supply; the propeller is used to control the underwater robot structure to move; the waterproof sealed compartment for equipment is used to provide a waterproof space for information collection equipment; the waterproof sealed compartment for power supply is used to provide power for the propeller and the waterproof sealed compartment for equipment; the central control module is used to collect environmental information and send movement instructions to the propeller according to the environmental information. The present invention can continuously monitor the growth environment and growth status of aquatic products, and provide the state and environmental information of the product itself for the fishing of aquatic products and the cold chain transportation after fishing, so as to maintain its optimal vitality after fishing and reduce storage and transportation losses.

Description

Underwater robot and control method for autonomously monitoring aquatic product status and growth environment

Technical Field

The present invention relates to the technical field of underwater robots, and in particular to an underwater robot and a control method for autonomously monitoring the state and growth environment of aquatic products.

Background Art

The ocean is rich in resources. Although the development and utilization of these resources are relatively limited, they have great potential to significantly improve human food security and well-being. In particular, underwater inspection operations in oyster farms are essential to maintaining the health and productivity of aquaculture, despite the threat to personnel safety and the high maintenance costs and complexity. With the development of artificial intelligence, more and more underwater machines are being invented for underwater operations to replace manual underwater operations.

However, existing underwater robots have design limitations, such as cable connections, limited range of motion, insufficient maneuverability, and cable entanglement, which result in low efficiency and poor working results of underwater robots.

Summary of the invention

In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide an underwater robot and a control method for autonomously monitoring the status of aquatic products and the growth environment. Environmental information is collected through a central control module, and the underwater robot is controlled to move according to the environmental information to avoid cable entanglement, increase the underwater activity range and mobility of the underwater robot, and improve the work efficiency of the underwater robot.

To achieve the above object, the present invention provides the following solutions:

An underwater robot for autonomously monitoring the state and growth environment of aquatic products comprises: an underwater robot structure, and a propeller, an equipment waterproof sealed compartment and a power supply waterproof sealed compartment arranged in the underwater robot structure; a central control module is arranged in the equipment waterproof sealed compartment;

The underwater robot structure is used to fix the propeller, the equipment waterproof sealed compartment and the power waterproof sealed compartment; the propeller is used to control the movement of the underwater robot structure; the equipment waterproof sealed compartment is used to provide a waterproof space for the information collection equipment; the power waterproof sealed compartment is used to provide power for the propeller and the equipment waterproof sealed compartment; the central control module is used to collect environmental information and send movement instructions to the propeller according to the environmental information.

Preferably, the underwater robot structure comprises: a base, a sealing chamber support structure, a side plate, a sealing chamber fixing ring and a floating block chamber;

The side plates are fixed on both sides of the base; the sealed bin support structure is arranged on the base; the floating block bin is arranged between the side plates and the sealed bin support structure; the sealed bin fixing ring is arranged on the sealed bin support structure;

The base is used to fix the side panel and the sealed chamber support structure; the sealed chamber support structure and the sealed chamber fixing ring are both used to fix the equipment waterproof sealed chamber and the power supply waterproof sealed chamber; the side panel is used to fix the floating block chamber; the floating block chamber is used to adjust the buoyancy and the center of gravity of the underwater robot structure.

Preferably, the propeller comprises: a front fairing, a propeller blade, a blade protection housing and a rear fairing connected in sequence;

The front fairing and the rear fairing are both used to reduce turbulence and vortices; the propeller blades are used to provide movement power for the underwater robot structure; and the blade protective shell is used to protect the propeller blades.

Preferably, four of the propellers are arranged on the base; two of the propellers are respectively arranged on the side plates on both sides of the base; the distribution state of the four propellers arranged on the base is horizontal diagonal distribution;

The four propellers arranged on the base are used to control the underwater robot structure to move forward, turn, retreat and horizontally rotate; the two propellers arranged on the side panels are used to control the underwater robot structure to float, dive and roll; the control formulas of the four propellers arranged on the base and the two propellers arranged on the side panels are: t is the thrust reduction ratio when the deflection angle is 0; T is the forward thrust; T ₀ is the downward thrust; x is the distance between the two thrusts; D is the thruster diameter; is the installation angle; The deflection angle for push down is Thrust reduction ratio.

Preferably, the equipment waterproof sealed compartment comprises: a transparent spherical sealing cover, a first rubber sealing ring, an equipment sealed compartment cylindrical shell, a second rubber sealing ring, a rear end sealing cover of the equipment compartment and a first waterproof sealing bolt connected in sequence;

The transparent spherical sealing cover, the cylindrical shell of the equipment sealing bin, the rear end sealing cover of the equipment bin, and the first waterproof sealing bolt are all used to construct the waterproof space; the first rubber sealing ring and the second rubber sealing ring are both used to improve the waterproofness of the waterproof space.

Preferably, the power supply waterproof sealed compartment comprises: a power supply compartment front sealing end cover, a power supply fixing groove, a third rubber sealing ring, a waterproof sealed compartment cylindrical shell, a fourth rubber sealing ring, a power supply compartment rear sealing end cover and a second waterproof sealing bolt connected in sequence;

The front sealing end cover of the power supply compartment, the power supply fixing groove, the third rubber sealing ring, the waterproof sealing compartment cylindrical shell, the fourth rubber sealing ring and the rear sealing end cover of the power supply compartment are all used to provide a dry environment for the target battery; the second waterproof sealing bolt is used to provide a power supply reserved hole for the waterproof sealing compartment of the equipment.

Preferably, the central control module is embedded with an inertial measurement unit, a Beidou satellite navigation unit, an abnormal condition processing unit, a relative rope navigation unit, a speed recorder, a camera, a seafloor geomorphometer and an environmental sensor element;

The inertial measurement unit is used to measure the three-axis attitude angle and acceleration of the underwater robot structure, and calculate the attitude of the underwater robot structure according to the three-axis attitude angle and the acceleration; the Beidou satellite navigation unit is used to collect the position information of the underwater robot structure; the abnormal condition processing unit is used to collect buoyancy data, energy data, attitude data, power data and water leakage data, and when the buoyancy data, the energy data, the attitude data, the power data and the water leakage data are abnormal, execute the emergency response plan; the emergency response plan includes: sending the underwater robot to the target base; The relative rope navigation unit is used to emit sonar microwaves, collect oyster farming rope information by measuring echoes, formulate an inspection path according to the oyster farming rope information, and estimate the oyster size density by measuring echoes, and obtain oyster growth information by comparing the oyster size density with the historical oyster size; the speed recorder is used to measure the speed of the underwater robot structure; the camera is used to collect oyster status information; the seabed topography instrument is used to generate a relative position map according to the measuring echoes; the environmental sensing element is used to collect farm environmental data.

Preferably, a method for controlling an underwater robot for autonomously monitoring the state and growth environment of aquatic products comprises:

Obtaining the location information of the target underwater robot;

Controlling the target underwater robot to reach a target breeding farm according to the position information;

Using side scan sonar and a preset ground station system to construct a relative position map of the target farm;

Using the ground station system to determine the validity of the relative position map; the validity includes: map validity and map invalidity;

When the validity is that the map is valid, controlling the underwater robot to move to the starting position of the suspension line of the target breeding farm;

According to the relative position map, using an interval sliding segmentation algorithm to identify the oyster farming rope information of the target farm;

developing an inspection route using the oyster farming rope information;

Using the inspection path to control the target underwater robot to conduct inspection;

When the target underwater robot completes its inspection, the target underwater robot is controlled to return to the target base.

Preferably, according to the relative position map, identifying the oyster farming rope information of the target farm using an interval sliding segmentation algorithm includes:

Collecting side scan signals;

dividing the side scan signal into a plurality of intermediate intervals;

calculating the interval mean least squares deviation for each of the intermediate intervals;

Calculate the difference of the least square deviation of the interval mean values of adjacent intermediate intervals;

The middle interval corresponding to the largest difference is output as the oyster farming rope information.

The present invention discloses the following technical effects:

The present invention provides an underwater robot and a control method for autonomously monitoring the status and growth environment of aquatic products. Through a central control module, the problems of cable entanglement, small range of activity, poor maneuverability and low work efficiency are solved, and the underwater robot can conduct autonomous underwater inspection of oysters; through a power waterproof sealed compartment, the energy source problem is solved, and cable-free power supply is realized; through a thruster, the problem of poor maneuverability of the underwater robot is solved, and the movement and rotation functions of the underwater robot are realized.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

FIG1 is a schematic diagram of the structure of an underwater robot provided by an embodiment of the present invention;

FIG2 is a schematic diagram of the structure of an underwater robot provided by an embodiment of the present invention;

FIG3 is a schematic diagram of the structure of a propeller provided in an embodiment of the present invention;

FIG4 is a schematic diagram of thruster distribution provided in an embodiment of the present invention;

FIG5 is a schematic diagram of the structure of a waterproof sealed cabin for equipment provided in an embodiment of the present invention;

FIG6 is a schematic diagram of the structure of a power supply waterproof sealed cabin provided in an embodiment of the present invention;

FIG7 is a control flow chart of an underwater robot provided by an embodiment of the present invention;

FIG8 is a schematic diagram of a water leakage sensor circuit according to an embodiment of the present invention;

FIG9 is a schematic diagram of path planning provided by an embodiment of the present invention;

Description of reference numerals:

1- underwater robot structure, 11- side plate, 12- floating block compartment, 13- sealed compartment fixing ring, 14- sealed compartment support structure, 15- base, 2- thruster, 21- front fairing, 22- propeller blade, 23- blade protection shell, 24- rear fairing, 3- equipment waterproof sealed compartment, 31- transparent spherical sealing cover, 32- first rubber sealing ring, 33- equipment sealed compartment cylindrical shell, 34- second rubber sealing ring, 35- equipment compartment rear end sealing cover, 36- first waterproof sealing bolt, 4- power supply waterproof sealed compartment, 41- power supply compartment front sealing end cover, 42- power supply fixing groove, 43- third rubber sealing ring, 44- waterproof sealed compartment cylindrical shell, 45- fourth rubber sealing ring, 46- power supply compartment rear sealing end cover, 47- second waterproof sealing bolt.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

The purpose of the present invention is to provide an underwater robot and a control method for autonomously monitoring the status of aquatic products and the growth environment. Environmental information is collected through a central control module, and the underwater robot is controlled to move according to the environmental information to avoid cable entanglement, increase the underwater activity range and mobility of the underwater robot, and improve the working efficiency of the underwater robot.

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

FIG1 is a schematic diagram of the structure of an underwater robot provided by an embodiment of the present invention. As shown in FIG1 , the present invention provides an underwater robot for autonomously monitoring the state and growth environment of aquatic products, comprising: an underwater robot structure 1, and a propeller 2, a device waterproof sealed compartment 3, and a power supply waterproof sealed compartment 4 arranged in the underwater robot structure 1; a central control module is arranged in the device waterproof sealed compartment 3;

The underwater robot structure 1 is used to fix the propeller 2, the equipment waterproof sealed compartment 3 and the power waterproof sealed compartment 4; the propeller 2 is used to control the movement of the underwater robot structure 1; the equipment waterproof sealed compartment 3 is used to provide a waterproof space for the information collection equipment; the power waterproof sealed compartment 4 is used to provide power for the propeller 2 and the equipment waterproof sealed compartment 3; the central control module is used to collect environmental information and send movement instructions to the propeller 2 according to the environmental information.

2 , the underwater robot structure 1 includes: a base 15 , a sealing chamber support structure 14 , a side plate 11 , a sealing chamber fixing ring 13 and a floating block chamber 12 ;

The side plates 11 are fixed on both sides of the base 15; the sealed chamber support structure 14 is arranged on the base 15; the floating block chamber 12 is arranged between the side plates 11 and the sealed chamber support structure 14; the sealed chamber fixing ring 13 is arranged on the sealed chamber support structure 14;

The base 15 is used to fix the side panel 11 and the sealed chamber support structure 14; the sealed chamber support structure 14 and the sealed chamber fixing ring 13 are both used to fix the equipment waterproof sealed chamber 3 and the power supply waterproof sealed chamber 4; the side panel 11 is used to fix the floating block chamber 12; the floating block chamber 12 is used to adjust the buoyancy and the center of gravity of the underwater robot structure 1.

Referring to FIG3 , the propeller 2 comprises: a front fairing 21, a propeller blade 22, a blade protection housing 23 and a rear fairing 24 connected in sequence;

The front fairing 21 and the rear fairing 24 are both used to reduce turbulence and vortexes; the propeller blades 22 are used to provide movement power for the underwater robot structure 1; and the blade protection housing 23 is used to protect the propeller blades 22.

Referring to FIG. 4 , four propellers 2 are arranged on the base 15 ; two propellers 2 are respectively arranged on the side plates 11 on both sides of the base 15 ; the distribution state of the four propellers 2 arranged on the base 15 is horizontal diagonal distribution;

The four propellers 2 arranged on the base 15 are used to control the underwater robot structure 1 to move forward, turn, retreat and horizontally rotate; the two propellers 2 arranged on the side plate 11 are used to control the underwater robot structure 1 to float, dive and roll; the control formulas of the four propellers 2 arranged on the base 15 and the two propellers 2 arranged on the side plate 11 are: t is the thrust reduction ratio when the deflection angle is 0; T is the forward thrust; T ₀ is the downward thrust; x is the distance between the two thrusts; D is the thruster diameter; is the installation angle; The deflection angle for push down is Thrust reduction ratio.

5, the equipment waterproof sealed chamber 3 comprises: a transparent spherical sealing cover 31, a first rubber sealing ring 32, an equipment sealed chamber cylindrical shell 33, a second rubber sealing ring 34, an equipment chamber rear end sealing cover 35 and a first waterproof sealing bolt 36 connected in sequence;

The transparent spherical sealing cover 31, the equipment sealing chamber cylindrical shell 33, the equipment chamber rear end sealing cover 35, and the first waterproof sealing bolt 36 are all used to construct the waterproof space; the first rubber sealing ring 32 and the second rubber sealing ring 34 are both used to improve the waterproofness of the waterproof space.

6 , the power supply waterproof sealed compartment 4 comprises: a power supply compartment front sealing end cover 41, a power supply fixing groove 42, a third rubber sealing ring 43, a waterproof sealed compartment cylindrical shell 44, a fourth rubber sealing ring 45, a power supply compartment rear sealing end cover 46 and a second waterproof sealing bolt 47 connected in sequence;

The front sealing end cover 41 of the power supply compartment, the power supply fixing groove 42, the third rubber sealing ring 43, the waterproof sealing compartment cylindrical shell 44, the fourth rubber sealing ring 45 and the rear sealing end cover 46 of the power supply compartment are all used to provide a dry environment for the target battery; the second waterproof sealing bolt 47 is used to provide a power supply reserved hole for the waterproof sealing compartment 3 of the equipment.

Furthermore, the central control module is embedded with an inertial measurement unit, a Beidou satellite navigation unit, an abnormal condition processing unit, a relative rope navigation unit, a speed recorder, a camera, a seafloor geomorphometer and an environmental sensor element;

The inertial measurement unit is used to measure the three-axis attitude angle and acceleration of the underwater robot structure 1, and calculate the attitude of the underwater robot structure 1 according to the three-axis attitude angle and acceleration; the Beidou satellite navigation unit is used to collect the position information of the underwater robot structure 1; the abnormal condition processing unit is used to collect buoyancy data, energy data, attitude data, power data and water leakage data, and when the buoyancy data, energy data, attitude data, power data and water leakage data are abnormal, execute the emergency response plan; the emergency response plan includes: sending the position information of the underwater robot structure 1 to the target base and controlling the underwater robot structure 1 to float up; the relative rope navigation unit is used to emit sonar microwaves, collect oyster farming rope information by measuring echoes, formulate an inspection path according to the oyster farming rope information, and estimate the oyster size density by measuring echoes, and obtain oyster growth information by comparing the oyster size density with the historical oyster size; the speed recorder is used to measure the speed of the underwater robot structure 1; the camera is used to collect oyster condition information; the seabed topography instrument is used to generate a relative position map according to the measuring echo; the environmental sensor element is used to collect farm environmental data.

Referring to FIG. 7 , a method for controlling an underwater robot for autonomously monitoring the state and growth environment of aquatic products includes:

Obtaining the location information of the target underwater robot;

Controlling the target underwater robot to reach a target breeding farm according to the position information;

Using side scan sonar and a preset ground station system to construct a relative position map of the target farm;

Using the ground station system to determine the validity of the relative position map; the validity includes: map validity and map invalidity;

When the validity is that the map is valid, controlling the underwater robot to move to the starting position of the suspension line of the target breeding farm;

According to the relative position map, using an interval sliding segmentation algorithm to identify the oyster farming rope information of the target farm;

developing an inspection route using the oyster farming rope information;

Using the inspection path to control the target underwater robot to conduct inspection;

When the target underwater robot completes its inspection, the target underwater robot is controlled to return to the target base.

Further, according to the relative position map, the interval sliding segmentation algorithm is used to identify the oyster farming rope information of the target farm, including:

Collecting side scan signals;

dividing the side scan signal into a plurality of intermediate intervals;

calculating the interval mean least squares deviation for each of the intermediate intervals;

Calculate the difference of the least square deviation of the interval mean values of adjacent intermediate intervals;

The middle interval corresponding to the largest difference is output as the oyster farming rope information.

Specifically, the underwater robot structure 1 is composed of a base 15 fixedly connected to two side plates 11, and a sealed chamber support structure 14 fixedly connected to the base 15. A floating block chamber 12 is fixedly installed on the upper part of the sealed chamber support structure 14 for installing floating blocks to adjust the buoyancy and center of gravity. When the floating block chamber 12 is installed on the upper part, the center of gravity of the underwater robot moves upward as a whole, which is conducive to stabilizing the posture of the underwater robot in the water and can be less affected by underwater undercurrents. A sealed chamber fixing ring 13 is fixedly installed on the sealed chamber support structure 14 to fix the waterproof sealed chamber 3 of the equipment to prevent the sealed chamber from sliding or falling off during the movement of the machine and affecting the operation of the underwater robot.

Optionally, the propeller blade 22 may be mounted on a waterproof brushless motor and powered by the waterproof brushless motor, and the waterproof brushless motor is fixed inside a protective housing of the propeller blade 22 .

Furthermore, due to the complex and changeable underwater environment, the underwater robot needs to be highly flexible in order to complete the corresponding work. Therefore, the two thrusters 2 are vertically fixed on the two side panels 11 for vertical motion control, such as floating, diving, and rolling; when diving, the two thrusters 22 rotate forward at the same time, giving the underwater robot a vertical downward force, so that the underwater robot can dive to the specified position; when rising, the thruster 2 reverses. The four thrusters 2 are arranged in a horizontal diagonal vector on the base 15, and are used for horizontal motion control, such as moving forward, turning, retreating, and horizontal rotation (see Figure 6). In this way, the six thrusters 2 can cooperate to realize the six-degree-of-freedom movement function, and can flexibly complete the corresponding actions. Its control formula:

Where t is the thrust reduction ratio at 0 deflection angle, T is the forward thrust, _T0 is the downward thrust, x is the distance between the two thrusts, D is the thruster diameter, is the installation angle, Push-down deflection angle In this way, it can be calculated that when the installation angle is 45°, each propeller 2 is not affected by the tail water flow generated when any propeller 2 is working. In addition, the resultant forces of the three axes XYZ of the propeller 2 are arranged in this way to converge at one point, which is close to the center of gravity of the body, and the additional movement caused by the torque can be avoided.

Furthermore, because the axes of the diagonal thrusters 2 on the base 15 are collinear, the turning radius is smaller, the maneuverability is better, and the endurance is improved compared to the arrangement in which the two axes of the diagonal thrusters 2 are parallel. When moving forward, the four thrusters 2 on the base 15 rotate forward at the same time; when moving backward, they reverse. When turning or rotating horizontally, the two diagonal thrusters 2 rotate in opposite directions to generate a torque, which enables the underwater robot to complete the turning or horizontal rotation. The mathematical model of AUV motion is also described using two coordinate systems: the earth-fixed A coordinate system and the body-fixed B coordinate system, and its dynamic equation can be expressed as:

M _η (n)=J ^-T (n)MJ ^-1 (n),

g _η (η) = J ^{- T} g (η),

τ _η (η)＝J ^-T (η)τ.

where η = [xyz φ θ] ^T , is the second-order derivative of the transformation matrix, is the first-order derivative of the transformation matrix, where T is the position and direction vector in the B coordinate system; v = [uvwpqr] ^T , where T is the overall linear velocity and angular velocity, τ = [XYZKMN] ^T , where T is the force and torque vector in the B coordinate system, J (η) is the transformation matrix between the A coordinate system and the B coordinate system; M is the inertia matrix containing the additional mass; C (v) is the matrix of Coriolis, centripetal and velocity related terms due to the increase in mass; D (v) is the damping matrix, which contains the resistance term; g (η) is gravity and buoyancy; τ is the control input. The underwater robot six-axis motion parameters refer to Table 1:

Table 1

Specifically, the transparent spherical sealing cover 31 of the equipment waterproof sealed compartment 3 is fixedly connected to the equipment sealed compartment cylindrical shell 33, and a rubber sealing ring is installed between the transparent spherical sealing cover 31 and the equipment sealed compartment cylindrical shell 33 for waterproof sealing. The equipment compartment rear end sealing cover 35 is fixedly waterproof and sealed with the equipment sealed compartment cylindrical shell 33 by installing a rubber sealing ring in the middle. The equipment compartment rear end sealing cover 35 on the equipment waterproof sealed compartment 3 is equipped with seven waterproof sealing bolts for subsequent circuit connection. The number of these waterproof sealing bolts is determined according to the maximum working water depth pressure that the equipment compartment rear end sealing cover 35 can withstand after the waterproof sealing bolts are installed.

Furthermore, the abnormal condition processing unit uses a single rule and multiple indicators to monitor the working state of the robot, mainly including: buoyancy monitoring, energy monitoring, attitude monitoring, power monitoring and sealed chamber leakage monitoring. Use a pressure sensor or a buoyancy sensor to monitor the buoyancy changes of the underwater robot to ensure normal operation; when an abnormality is found, adjust the center of gravity of the robot to enable it to maintain balanced buoyancy. Monitor the battery status, energy consumption and charging status of the underwater robot through a battery management unit or an energy monitoring device; when an abnormality is found, replace or repair the damaged energy equipment in time. Use sensors such as gyroscopes, accelerometers and magnetometers to monitor the attitude changes of the underwater robot to ensure that it can maintain a stable attitude; when an abnormality is found, recalibrate the attitude sensor or replace the damaged sensor. Use a thruster 2 monitoring device or a steering gear monitoring device to monitor the working state of the power unit of the underwater robot (including propulsion and direction control, etc.); when an abnormality is found, repair or replace the damaged power equipment. Underwater pressure sensors or water leakage detectors are used to monitor whether the sealed compartment of the underwater robot is leaking, as well as the location and extent of the leakage. When abnormalities are found, the seals at the leaking parts are repaired or replaced to ensure the integrity of the sealed compartment.

Furthermore, when an abnormality occurs when the machine performs the inspection task, an emergency alarm is sent to the ground workstation, and the coordinates of the machine position are sent. In addition, if two or more abnormal situations occur, it will first be determined whether there is a power abnormality. If there is no power abnormality in multiple abnormal situations, it will urgently float to the surface while sending the position. If the power is abnormal, the last coordinate position is sent, and after receiving the coordinate position, it will be salvaged and recovered manually at the corresponding location. The weight of the power abnormality in the machine performing the inspection task is greater than any abnormal situation. After the machine is recovered, the machine is repaired according to the abnormal situation of the machine alarm. In addition, the water leakage sensor (refer to Figure 8) is installed at the edge of the door of the waterproof sealed warehouse 3 of the underwater robot equipment, which is prone to water leakage. In addition, the head, middle and tail of the warehouse body of the underwater robot are equipped with water leakage sensors for detecting humidity, so as to achieve the purpose of multi-directional monitoring of the water leakage of the sealed warehouse.

Specifically, a rubber sealing ring is installed between the power supply compartment front sealing end cover 41 and the waterproof sealing compartment cylindrical shell 44 of the power supply waterproof sealing compartment 4, and a rubber sealing ring is installed between the power supply compartment rear sealing end cover 46 and the waterproof sealing compartment cylindrical shell 44. A waterproof sealing bolt is installed on the power supply compartment rear sealing end cover 46 to connect the power supply line.

Specifically, the central control unit includes: inertial measurement unit (IMU), Beidou satellite navigation unit (BDS), abnormal condition processing unit, relative rope navigation unit, speed recorder, camera, seabed topography instrument and environmental sensor element. The camera provides actual inspection data of the oyster condition, while the environmental sensor can collect some basic environmental data of the farm. The inertial measurement unit measures the three-axis attitude angle (or angular rate) and acceleration of the underwater robot, and uses this to calculate the attitude of the underwater robot.

Furthermore, the relative rope navigation unit can be used for long-distance observation via side-scan sonar. In addition to providing high-resolution observation of ropes and buoys, side-scan sonar can also provide useful signals for oyster growth rate, making it an ideal sensor for monitoring oyster farms. Because underwater vehicles are subject to significant current drift when submerged, and the layout of farms evolves over time; therefore, an effective monitoring solution requires not only locating the farm itself, but also being able to accurately control the path of the vehicle along the buoy, and this embodiment uses a relative rope navigation unit to achieve the above functions.

Specifically, this embodiment uses the interval sliding segmentation algorithm to identify the ropes and buoys in the oyster farm by identifying the change points in the sonar signal. The specific process is as follows: a maximum interval is cut out in the one-dimensional sonar signal. The interval size is dynamic and can be calculated by RTT (round trip delay). The maximum interval is input into the interval sliding segmentation algorithm model. If congestion occurs, the interval is reduced; the above work is repeated until the interval size without congestion is reached, and then the mean value and variance of the signal are calculated in the interval, and the variance difference between two adjacent intervals is compared. This difference is recorded in the form of a score, and the higher the score, the more significant the change in signal strength. The above method has a relatively low computational difficulty and is only proportional to the length of the sonar return vector, so it is more efficient and more practical. Through this technology, underwater navigation can be performed more accurately, thereby improving the management efficiency and productivity of oyster farms. The following is a theoretical calculation description: s represents a 1D side scan signal with a total length of T, and s _i:i+t represents an interval of a signal with a length of t starting from index i. For each interval, the least squares deviation from the interval mean is calculated as follows:

Where s _i:i+t represents the interval of the signal with length t starting from index i, and m(s _i:i+t ) represents the least square deviation value of the interval mean. is the average signal strength within the interval, that is y _n represents the signal strength within the interval

The calculation formula for the difference between two adjacent intervals is:

k(s _i:i+t ,s _i+t:i+2t )=m(s _i:i+2t )-m(s _i:i+t )-m(s _i+t:i+2t )

k(s _i:i+t ,s _i+t:i+2t ) represents the difference in cost of splitting the sub-signal S _(i:i+2t) at index (i+t). To detect a change point in the signal, an interval of size t is slid across the signal and the index with the largest difference is selected as the change point. Furthermore, the lowest point is the first acoustic echo received by the side scan that hits the bottom. By definition, the change in signal strength can be large. To avoid misdetecting the lowest point as an object, the detection algorithm runs two interval sliding calculations, first identifying the lowest point and then identifying the object in the water column. Similarly, ropes can be detected by changing the sliding interval size and the signal change rate.

Specifically, the index does not refer to anything. This is a function statement in the algorithm. The python index() method detects whether the string contains the string str. If the beg (i in the beginning text) and end (t in the end text) range are specified, it checks whether the string str is contained in the specified range. If the string is contained, the starting index value is returned, otherwise an exception is thrown. In short, the index() method finds the given element in the list and returns its position. If the same element appears multiple times, the method returns the index of the first occurrence of the element.

Referring to Figure 9, the relative rope navigation unit can control the autonomous underwater robot (AUV) to maintain a suitable visual inspection distance position. The core of the method is to use the oyster farming rope data detected in the last few times to construct a predetermined straight line path. Specifically, the method projects an ideal straight line trajectory by analyzing the position of the rope; the control unit calculates and sets the path offset of the underwater robot to ensure that it moves along this straight line. In order to effectively follow this straight line path, the unit adopts a line of sight guidance law based on forward steering. This guidance law can provide the robot with an accurate set point to ensure that the AUV is in the correct direction and position when performing tasks. The set point calculation formula is: ψ _d ＝ψ _p +ψ _r ; where ψ _p is the angle at which the X-axis is tangent to the straight line path, and ψ _r is the relative angle of the velocity path. The path tangent angle can be calculated by the intercept, and its calculation formula is: The speed-path relative angle is calculated as: The key to the line-of-sight guidance law is to use the cross-track error e between the current AUV position and the desired path to adjust the AUV's heading so that it is as close to the desired path as possible. By continuously monitoring and updating the heading angle, the AUV can effectively follow the pre-planned waypoint sequence while maintaining a certain forward-looking distance d.

Specifically, the speed recorder uses the Doppler effect to measure the speed. The speed recorder is fixedly installed on the bottom of the underwater robot. When installing, the three axes of the Doppler speed recorder coordinate system are adjusted to be parallel to the three axes of the carrier coordinate system. Since the navigation speed V of the underwater robot is much smaller than the propagation speed V1 of the sound wave in water, the change of the emission inclination angle caused by the change of the position of the underwater robot during the time period from the sound wave being emitted to the sound wave being received is ignored. V can be calculated by the Doppler effect as follows: Among them, _f0 is the natural frequency of the sound wave signal emitted by the speed recorder, _fd is the frequency difference between the sound wave signals emitted and received by the Doppler speed recorder, and α is the angle between the navigation direction of the underwater robot and the direction of the sound wave emitted by the Doppler recorder.

Furthermore, the prior art usually uses INS (inertial navigation) and DVL (Doppler velocimeter) combined navigation for positioning, because this combined navigation has the characteristics of high autonomy, high positioning accuracy, and strong stability, but as the range increases, the positioning error will also increase. After a long period of underwater operation, the AUV will automatically surface to receive GNSS information through the Beidou navigation system and the receiver to calibrate the position and eliminate the accumulated error. At the same time, the GNSS information can be input into the Kalman filter as an observation, and the characteristics of the unit and the actual application requirements are combined when selecting the Kalman filter algorithm. The standard Kalman filter algorithm is suitable for linear units, but it can also be used for combined navigation, and the nonlinear errors of nonlinear units are separated by designing the input parameters of the filter. When the state variable of the combined navigation unit adopts the error amount of the navigation output parameter, the high-order coupling terms between the error amounts are ignored, and the combined navigation unit is simplified to a linear unit. In this case of underwater machine automatic inspection of oyster farms, the standard Kalman filter algorithm is applicable. The Kalman filter is used to estimate and eliminate the accumulated velocity and attitude angle errors to complete the calibration. After completing the calibration, the AUV went into the water again and continued to perform underwater operations using INS and DVL combined navigation.

Preferably, the specific workflow of the AUV machine for autonomously inspecting the oyster farm (see Figure 7) mainly includes: the AUV is started and GPS positioning is obtained; the AUV arrives near the farm as planned; the AUV hovers around the farm, and the machine status monitoring module monitors in real time through monitoring indicators such as cabin leakage, water monitoring, power monitoring, attitude monitoring, energy monitoring, and buoyancy monitoring to ensure that the machine is in good operating condition and any abnormalities are discovered in time. If any abnormality occurs, the system will surface urgently and send the location coordinates. Use side scan sonar to detect the pillars of the oyster farm and build a map of the farm relative to the AUV; determine whether a valid map is built; use the built map to move to the starting point of the oyster farm hanging line; at the same time, the machine's environmental monitoring module is equipped with environmental sensors for real-time monitoring, detecting parameters such as algae organic matter content, pH value, temperature, dissolved oxygen concentration, salinity, color, etc. in the water body of the oyster farm, and monitoring the shell shape, integrity, and hanging rope of the oysters. Each monitoring line will store data in real time to ensure continuous monitoring and recording of the oyster farming environment, so that necessary measures can be taken in time to ensure the growth and health of oysters. Start surveying the line according to the previously drawn map; after detecting some lines using the side scan sonar, switch to line patrol; perform a 180-degree turn at the end of the line to position the AUV on the other side of the line (now between two lines); the machine surfaces at the turn, obtains BDS position information to calibrate the position and eliminate accumulated errors, and uses the previous detection of the first line seen from the first side and the known previous line spacing to track the line until sufficient detection of the next line is found. Combine the ground station and side scan sonar to track the line using the previous detection of the first line seen from the first side and the known previous line spacing until sufficient detection of the next line is found; Combine the ground station and side scan sonar to determine whether all lines have been surveyed; complete the planned task and return to the base; analyze and organize the real-time transmitted data through the ground station, compare the downloaded data to confirm consistency, and formulate a corresponding breeding plan. After completing the planned task, the data is fed back to the base, providing the status and environmental information of the product itself for the fishing of aquatic products and the cold chain transportation after fishing, so as to maintain its optimal vitality after fishing and reduce storage and transportation losses. This process ensures the smooth operation of the farm and subsequent survival transportation, improves production efficiency, and provides effective support for farm management and survival transportation.

The beneficial effects of the present invention are as follows:

The present invention solves the problems of cable entanglement, small range of activity, poor maneuverability and low work efficiency through a central control module, thereby realizing autonomous underwater inspection of oysters by an underwater robot; solves the problem of energy source through a waterproof and sealed power supply compartment, thereby realizing cable-free power supply; and solves the problem of poor maneuverability of the underwater robot through a thruster, thereby realizing the movement and rotation functions of the underwater robot.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

Those skilled in the art will appreciate that other similar connection methods may also be used to implement the present invention, such as welding, bonding or screwing.

This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims (9)

1. An underwater robot for autonomously monitoring the status and growth environment of aquatic products, characterized in that it comprises: an underwater robot structure, and a propeller, an equipment waterproof sealed compartment and a power waterproof sealed compartment arranged in the underwater robot structure; a central control module is arranged in the equipment waterproof sealed compartment; The underwater robot structure is used to fix the propeller, the equipment waterproof sealed compartment and the power waterproof sealed compartment; the propeller is used to control the movement of the underwater robot structure; the equipment waterproof sealed compartment is used to provide a waterproof space for the information collection equipment; the power waterproof sealed compartment is used to provide power for the propeller and the equipment waterproof sealed compartment; the central control module is used to collect environmental information and send movement instructions to the propeller according to the environmental information. 2. An underwater robot for autonomously monitoring the status and growth environment of aquatic products according to claim 1, characterized in that the underwater robot structure comprises: a base, a sealing chamber support structure, a side plate, a sealing chamber fixing ring and a floating block chamber; The side plates are fixed on both sides of the base; the sealed bin support structure is arranged on the base; the floating block bin is arranged between the side plates and the sealed bin support structure; the sealed bin fixing ring is arranged on the sealed bin support structure; The base is used to fix the side panel and the sealed chamber support structure; the sealed chamber support structure and the sealed chamber fixing ring are both used to fix the equipment waterproof sealed chamber and the power supply waterproof sealed chamber; the side panel is used to fix the floating block chamber; the floating block chamber is used to adjust the buoyancy and the center of gravity of the underwater robot structure. 3. An underwater robot for autonomously monitoring the status and growth environment of aquatic products according to claim 1, characterized in that the propeller comprises: a front fairing, a propeller blade, a blade protection housing and a rear fairing connected in sequence; The front fairing and the rear fairing are both used to reduce turbulence and vortices; the propeller blades are used to provide movement power for the underwater robot structure; and the blade protective shell is used to protect the propeller blades. 4. The underwater robot for autonomously monitoring the status and growth environment of aquatic products according to claim 2, characterized in that four of the propellers are arranged on the base; two of the propellers are respectively arranged on the side panels on both sides of the base; the distribution state of the four propellers arranged on the base is horizontal diagonal distribution; The four propellers arranged on the base are used to control the underwater robot structure to move forward, turn, retreat and horizontally rotate; the two propellers arranged on the side panels are used to control the underwater robot structure to float, dive and roll; the control formulas of the four propellers arranged on the base and the two propellers arranged on the side panels are: t is the thrust reduction ratio when the deflection angle is 0; T is the forward thrust; T ₀ is the downward thrust; x is the distance between the two thrusts; D is the thruster diameter; is the installation angle; The deflection angle for push down is Thrust reduction ratio. 5. According to claim 1, an underwater robot for autonomously monitoring the status and growth environment of aquatic products is characterized in that the equipment waterproof sealing chamber comprises: a transparent spherical sealing cover, a first rubber sealing ring, a cylindrical shell of the equipment sealing chamber, a second rubber sealing ring, a sealing cover at the rear end of the equipment chamber, and a first waterproof sealing bolt connected in sequence; The transparent spherical sealing cover, the cylindrical shell of the equipment sealing bin, the rear end sealing cover of the equipment bin, and the first waterproof sealing bolt are all used to construct the waterproof space; the first rubber sealing ring and the second rubber sealing ring are both used to improve the waterproofness of the waterproof space. 6. An underwater robot for autonomously monitoring the status and growth environment of aquatic products according to claim 1, characterized in that the power supply waterproof sealed compartment comprises: a power supply compartment front sealing end cover, a power supply fixing groove, a third rubber sealing ring, a waterproof sealed compartment cylindrical shell, a fourth rubber sealing ring, a power supply compartment rear sealing end cover and a second waterproof sealing bolt connected in sequence; The front sealing end cover of the power supply compartment, the power supply fixing groove, the third rubber sealing ring, the waterproof sealing compartment cylindrical shell, the fourth rubber sealing ring and the rear sealing end cover of the power supply compartment are all used to provide a dry environment for the target battery; the second waterproof sealing bolt is used to provide a power supply reserved hole for the waterproof sealing compartment of the equipment. 7. An underwater robot for autonomously monitoring the status and growth environment of aquatic products according to claim 1, characterized in that the central control module is embedded with an inertial measurement unit, a Beidou satellite navigation unit, an abnormal condition processing unit, a relative rope navigation unit, a speed recorder, a camera, a seafloor topography instrument and an environmental sensor element; The inertial measurement unit is used to measure the three-axis attitude angle and acceleration of the underwater robot structure, and calculate the attitude of the underwater robot structure according to the three-axis attitude angle and the acceleration; the Beidou satellite navigation unit is used to collect the position information of the underwater robot structure; the abnormal condition processing unit is used to collect buoyancy data, energy data, attitude data, power data and water leakage data, and when the buoyancy data, the energy data, the attitude data, the power data and the water leakage data are abnormal, execute the emergency response plan; the emergency response plan includes: sending the underwater robot to the target base; The relative rope navigation unit is used to emit sonar microwaves, collect oyster farming rope information by measuring echoes, formulate an inspection path according to the oyster farming rope information, and estimate the oyster size density by measuring echoes, and obtain oyster growth information by comparing the oyster size density with the historical oyster size; the speed recorder is used to measure the speed of the underwater robot structure; the camera is used to collect oyster status information; the seabed topography instrument is used to generate a relative position map according to the measuring echoes; the environmental sensing element is used to collect farm environmental data. 8. A method for controlling an underwater robot for autonomously monitoring the state and growth environment of aquatic products, characterized by comprising: Obtaining the location information of the target underwater robot; Controlling the target underwater robot to reach a target breeding farm according to the position information; Using side scan sonar and a preset ground station system to construct a relative position map of the target farm; Using the ground station system to determine the validity of the relative position map; the validity includes: map validity and map invalidity; When the validity is that the map is valid, controlling the underwater robot to move to the starting position of the suspension line of the target breeding farm; According to the relative position map, using an interval sliding segmentation algorithm to identify the oyster farming rope information of the target farm; developing an inspection route using the oyster farming rope information; Using the inspection path to control the target underwater robot to conduct inspection; When the target underwater robot completes its inspection, the target underwater robot is controlled to return to the target base. 9. The method for controlling an underwater robot for autonomously monitoring the status and growth environment of aquatic products according to claim 8, characterized in that, according to the relative position map, an interval sliding segmentation algorithm is used to identify the oyster farming rope information of the target farm, including: Collecting side scan signals; dividing the side scan signal into a plurality of intermediate intervals; calculating the interval mean least squares deviation for each of the intermediate intervals; Calculate the difference of the least square deviation of the interval mean values of adjacent intermediate intervals; The middle interval corresponding to the largest difference is output as the oyster farming rope information.