A ring-shaped underwater robot and its control method

Abstract

The present invention discloses a ring-shaped underwater robot and a control method thereof. The ring-shaped underwater robot comprises a ring-shaped robot body, the hollow portion of which serves as a water channel, and a plurality of propellers and a plurality of servos disposed within the water channel. Different control strategies are employed for different operating modes. The ring-shaped underwater robot of the present invention improves stealth, maneuverability, and endurance.

Description

Technical Field

[0001] The present invention belongs to the technical field of underwater equipment, and in particular relates to a ring-shaped underwater robot and an identification method. Background Art

[0002] Underwater vehicles originated in the 1950s and include three categories: manned underwater vehicles, remote-controlled underwater vehicles, and unmanned underwater vehicles. Manned underwater vehicles are operated by humans inside the underwater vehicle to complete driving and operations. Remote-controlled underwater vehicles are underwater vehicles connected to a dispatching platform via cables or acoustic transmission systems and are mainly used for commercial activities. Unmanned underwater vehicles are equipped with battery packs and sonar systems and have no operator. Due to their unmanned and autonomous operation, their diving depth and safety limits offer significant advantages, and they have gradually become the focus of research and development in academia and industry. Underwater robots are a type of underwater vehicle and are key equipment in oceanographic research, offshore waterway surveys, mineral resource exploration, seabed infrastructure construction, maritime search and rescue, and salvage.

[0003] Currently common underwater robots, on the one hand, their propellers are usually arranged at the stern, affecting the overall stealth; on the other hand, they usually adopt a single propeller and single rudder structure, which affects the overall maneuverability and endurance. Summary of the Invention

[0004] In view of this, an object of the present invention is to provide a ring-shaped underwater robot and an identification method so as to improve stealth, maneuverability and endurance.

[0005] The present invention solves the above problems through the following technical means:

[0006] A ring-shaped underwater robot comprises a ring-shaped robot body, wherein the hollow portion of the robot body is a water channel, and a plurality of propellers and a plurality of steering gears are arranged in the water channel.

[0007] Furthermore, the propeller includes a first propeller and a second propeller.

[0008] Furthermore, the steering gear includes a main rudder and an auxiliary rudder.

[0009] Furthermore, the auxiliary rudder is arranged at the center of gravity of the robot body.

[0010] Furthermore, the main rudder is arranged at the stern of the robot body.

[0011] In a control method of the above-mentioned ring-shaped underwater robot, when the underwater robot is performing straight-line movement or small-amplitude movement, only the auxiliary rudder works; when the underwater robot is performing large-amplitude horizontal or vertical maneuvers, the main rudder works, or the auxiliary rudder and the main rudder work together.

[0012] Furthermore, the underwater robot uses the main rudder and auxiliary rudder to correct the depth error and pitch angle error caused by the disturbance; when there is only a depth error, it is necessary to judge the size of the depth error. When the error is less than the threshold, the depth adjustment is only performed through the auxiliary rudder. When the error is greater than the threshold, the error is reduced by the main rudder. The definition of the threshold is related to the size of the underwater robot and the rudder effect; when the pitch angle has an error due to the disturbance, on the one hand, the pitch angle is adjusted by the main rudder, and on the other hand, the depth error caused by the pitch angle is corrected by the auxiliary rudder.

[0013] Furthermore, the dual-thruster working logic of the underwater robot has a normal mode and a stealth mode. When the working mode is the stealth mode, the rotation speeds of the two thrusters remain the same, and the propeller rotation speed is controlled to the lowest to reduce underwater noise; when the working mode is the normal mode, one of the thrusters is started first until the propeller rotation speed reaches the most efficient point or reaches the set speed; when the propeller rotation speed reaches the best efficient speed point and the underwater robot has not reached the target speed, the first thruster is kept working at the most efficient speed, and the second thruster rotation speed is gradually increased until the underwater robot reaches the target speed. If the two thrusters are at the most efficient speed point and the underwater robot speed still has not reached the target speed, the two thrusters continue to increase the rotation speed synchronously until the target speed is reached.

[0014] Beneficial effects of the present invention:

[0015] The annular underwater robot and identification method of this application, on the one hand, adopts an annular hollow design for the underwater robot body, with the hollow portion serving as a water channel and the annular portion serving as the robot body. The annular portion has a relatively small flow area, resulting in lower navigation resistance. On the other hand, the propeller and rudder system are arranged inside the water channel, thereby reducing the operating noise of the propeller and rudder system, reducing the reflection area, and improving the stealth performance of the underwater robot. In addition, the arrangement of multiple propellers can reduce the size and speed of a single propeller, thereby reducing the operating noise of the propeller. Multiple rudder systems are arranged at different locations, with the auxiliary rudder at the center of gravity and the main rudder at the stern. Different rudder systems are used under different operating conditions. The arrangement of the main and auxiliary rudders improves the robot's track stability and endurance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings and examples.

[0017] Figure 1 A schematic structural diagram of a preferred embodiment of the present invention;

[0018] Figure 2 Flow chart of main and auxiliary rudder operations;

[0019] Figure 3This is the working flow diagram of the dual thruster.

[0020] Numbers in the figure: 1-first thruster; 2-second thruster; 3-auxiliary rudder; 4-main rudder; 5-robot body. DETAILED DESCRIPTION

[0021] The present invention will be described in detail below with reference to the accompanying drawings.

[0022] like Figure 1 As shown, this embodiment provides, on one hand, an annular underwater robot, comprising an annular robot body 5. The hollow portion of the robot body serves as a water channel, within which are disposed multiple thrusters and multiple steering gears. The thrusters include a first thruster 1 and a second thruster 2. The steering gear includes a main rudder 4 and an auxiliary rudder 3. The auxiliary rudder is positioned at the center of gravity of the robot body. The main rudder is positioned at the stern of the robot body.

[0023] The underwater robot body adopts a hollow annular design, with the hollow part being the water guide channel and the annular part being the robot body. The flow area of the annular part is relatively small, and the navigation resistance is lower.

[0024] The propeller and rudder system are arranged inside the water channel, thereby reducing the operating noise of the propeller and rudder system, reducing the reflection area, and improving the stealth performance of the underwater robot.

[0025] Multiple propeller and rudder systems are used. The arrangement of multiple propellers can reduce the size and speed of a single propeller, thereby reducing the operating noise of the propeller. Multiple rudder systems are arranged in different locations, with the auxiliary rudder at the center of gravity and the main rudder at the stern. Different rudder systems are used under different working conditions. The arrangement of main and auxiliary rudders improves the robot's track stability and endurance.

[0026] The working process of the main rudder and auxiliary rudder is as follows: when the underwater robot is performing straight-line movement or small-amplitude movement, only the auxiliary rudder works; when the underwater robot is performing large-amplitude horizontal or vertical maneuvers, the main rudder works or the auxiliary rudder and the main rudder work together.

[0027] When the underwater robot is moving straight ahead or in small movements, only the auxiliary rudder is active. Because the auxiliary rudder is located near the robot's center of gravity, the hydrodynamic force generated by the auxiliary rudder's deflection coincides with the robot's center of gravity. This hydrodynamic force directly causes the robot to move laterally or vertically, correcting for positional deviations.

[0028] When the underwater robot performs large horizontal or vertical maneuvers, the main rudder or the auxiliary rudder and the main rudder work together. During large maneuvers, the main rudder is farther away from the robot's center of gravity. While the main rudder generates less hydrodynamic force, the robot generates a larger deflection torque.

[0029] On the other hand, this embodiment provides a method for controlling the above-mentioned annular underwater robot. When the underwater robot is performing straight-line movement or small-amplitude movement, only the auxiliary rudder works; when the underwater robot is performing large-amplitude horizontal or vertical maneuvers, the main rudder works, or the auxiliary rudder and the main rudder work together.

[0030] The underwater robot uses the main rudder and auxiliary rudder to correct the depth error and pitch angle error caused by disturbance. The working logic of the main and auxiliary rudders is as follows: Figure 2 As shown in the figure, when only a depth error exists, the magnitude of the depth error needs to be determined. When the error is less than a threshold, depth adjustment can be performed using only the auxiliary rudder. When the error exceeds the threshold, the main rudder is used to reduce the error. The definition of the threshold depends on the size of the underwater robot, the rudder efficiency, and other factors. When the pitch angle error is caused by a disturbance, the main rudder is used to adjust the pitch angle, while the auxiliary rudder is used to correct the depth error caused by the pitch angle. The combined operation of the main and auxiliary rudders can improve the underwater robot's maneuverability and reduce the impact of the underactuated characteristics of the rotating underwater robot.

[0031] The dual-thruster working logic of the underwater robot has two modes. The normal mode is characterized by low energy consumption and high propulsion efficiency; the stealth mode is characterized by low underwater noise and small water disturbance. Figure 3 As shown in the figure, when the operating mode is stealth mode, the speed of the two propellers remains the same, and the propeller speed is controlled to the lowest possible level to reduce underwater noise. When the operating mode is normal mode, one of the propellers is started first until the propeller speed reaches the most efficient point or the set speed. When the propeller speed reaches the optimal efficient point and the underwater robot has not reached the target speed, the first propeller is maintained at the most efficient speed and the speed of the second propeller is gradually increased until the underwater robot reaches the target speed. If the underwater robot speed still does not reach the target speed when both propellers are at the most efficient point, the two propellers continue to increase their speed synchronously until the target speed is reached.

[0032] It is necessary to point out that in the description of the present invention, the orientation or position relationship indicated by the terms "upper end", "upper part", "upper section", "lower section", "axial" and the like is based on the orientation or position relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for controlling a ring-shaped underwater robot, characterized in that: The annular underwater robot comprises an annular robot body, the hollow portion of the robot body being a water channel, wherein a plurality of propellers and a plurality of steering gears are arranged in the water channel; the propellers comprising a first propeller and a second propeller; the steering gears comprising a main rudder and an auxiliary rudder; the auxiliary rudder being arranged at the center of gravity of the robot body; and the main rudder being arranged at the stern of the robot body; When the underwater robot is performing straight-line movement or small-amplitude movement, only the auxiliary rudder works; when the underwater robot is performing large-amplitude horizontal or vertical maneuvers, the main rudder works, or the auxiliary rudder and the main rudder work together; The underwater robot uses the main rudder and auxiliary rudder to correct the depth error and pitch angle error caused by disturbances. When there is only a depth error, the size of the depth error needs to be judged. When the error is less than the threshold, the depth adjustment is only performed through the auxiliary rudder. When the error is greater than the threshold, the error is reduced by the main rudder. The definition of the threshold is related to the size of the underwater robot and the rudder effect. When the pitch angle has an error due to disturbance, the pitch angle is adjusted by the main rudder on the one hand, and the depth error caused by the pitch angle is corrected by the auxiliary rudder on the other hand.

2. The method for controlling a ring-shaped underwater robot according to claim 1, wherein: The dual-thruster operating logic of the underwater robot has a normal mode and a stealth mode. When the working mode is stealth mode, the speed of the two thrusters remains the same, and the speed of the thrusters is controlled to the lowest to reduce underwater noise; When the working mode is normal mode, start one of the propellers first until the propeller speed reaches the most efficient point speed or reaches the set speed; when the propeller speed reaches the best efficient speed point and the underwater robot has not reached the target speed, keep the first propeller working at the most efficient speed, and gradually increase the speed of the second propeller until the underwater robot reaches the target speed. If the two propellers are at the most efficient speed point and the speed of the underwater robot still has not reached the target speed, the two propellers continue to increase the speed synchronously until the target speed is reached.

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