An underwater helicopter with an attitude regulator and an attitude control method thereof

Abstract

The present invention relates to an underwater helicopter with an attitude regulator and its attitude control method. The underwater helicopter comprises a waterproof electronics compartment, a support member, an attitude regulation system, a propulsion system, an upper shell, and a lower shell. The upper shell and lower shell are fixed to the upper and lower ends of the support member to form a main body shell. The propulsion system includes two horizontal thrusters and four vertical thrusters, as well as a motor speed regulator for controlling the thruster speeds. The waterproof electronics compartment is fixed to the exact center of the support member. The present invention's efficient attitude regulation mechanism possesses exceptional capabilities, enabling precise and flexible adjustment of any complex attitude, ensuring the long-term stability and high reliability of the mechanism's operation.

Description

Technical Field

[0001] The present invention relates to the field of underwater robots, in particular to an underwater helicopter with a posture regulator and a posture control method thereof. Background Art

[0002] As the development and utilization of marine resources encompass ever-broader technological fields, the operational scope of untethered autonomous underwater vehicles (AUVs) continues to expand. These challenges are compounded by fluctuating weather conditions, diverse operating areas, and increasingly complex mission requirements. Attitude adjustment plays a crucial role in the operation and missions of autonomous underwater vehicles (AUVs). In underwater environments, external factors such as currents and waves can disrupt the AUV, causing its attitude to fluctuate. These factors can cause the robot to lose balance or even cease operation. In contrast, if an AUV could self-adjust through an attitude balancing mechanism, it would offer advantages such as long range, low loss, and high efficiency.

[0003] When an AUV encounters wave or surge disturbances, it can experience unstable attitudes, such as roll and pitch. Without a control mechanism, it's difficult to accurately and efficiently complete missions. To date, several main methods have been used to achieve attitude control, such as counterweights, buoyancy blocks, changes in cabin water volume, and movable masses. AUVs equipped with these attitude controllers can flexibly adapt to various mission requirements, thereby improving mission efficiency and versatility. To date, the basic principles of attitude controllers have revolved around repositioning the center of gravity and center of buoyancy.

[0004] However, most attitude adjustments typically occur within a limited range, typically less than 50 degrees, and exhibit a certain amount of hysteresis due to the need to adjust the position of the moving payload. Untethered autonomous underwater vehicles (AUVs) typically require continuous thruster propulsion during attitude changes. This attitude control mode not only consumes a large amount of energy but also lacks precision and stability. Therefore, the present invention proposes an underwater helicopter with an attitude adjuster and an attitude control method thereof. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the existing untethered autonomous underwater vehicle (AUV) in attitude adjustment. An underwater helicopter with an attitude adjuster and an attitude control method thereof are proposed to achieve the balance of pitch and roll as well as the ascent and descent functions of the underwater helicopter. The invention has the characteristics of simple structure and convenient control.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An underwater helicopter with an attitude regulator, comprising: a waterproof electronic cabin, a support, an attitude regulation system, a propulsion system, an upper shell and a lower shell:

[0008] The upper shell, the lower shell and the aluminum ring are fixed to the upper and lower ends of the support by bolts to form a main shell. The main shell is a flat disc-shaped structure. The propulsion system includes two horizontal thrusters and four vertical thrusters and a motor speed regulator for controlling the thruster speed. The two horizontal thrusters are respectively located on the left and right sides of the underwater helicopter, and the four vertical thrusters are fixed on the support; the waterproof electronic cabin is fixed at the center of the support.

[0009] As a further technical solution of the present invention, the posture adjustment system includes a buoyancy center adjustment structure and a gravity center adjustment structure.

[0010] As a further technical solution of the present invention, the buoyancy center adjustment structure includes an upper ball bearing, a lower ball bearing, two waterproof servo motors, two encoders, an upper floating block and a lower floating block;

[0011] Among them, the outer rings of the upper and lower ball bearings, the waterproof servo motor and the encoder are all fixed on the support frame, and the upper and lower floating blocks are respectively fixed on the inner rings of the upper and lower ball bearings; the inner rings of the ball bearings are driven by two waterproof servo motors through gears, so that the floating blocks installed on the inner rings rotate with the inner rings; the two encoders respectively measure the rotation angles of the inner rings of the upper and lower ball bearings.

[0012] As a further technical solution of the present invention, the center of gravity adjustment structure includes a skeleton, an angle sensor, a movable load, a screw, a ball screw, a linear bearing, a servo motor and a posture sensor;

[0013] The frame is fixed to the aluminum ring, and the angle sensor, lead screw and servo motor are all fixed to the frame;

[0014] The moving load and the linear bearing are fixed together and move vertically up and down following the lead screw; the servo motor drives the ball screw through the gear set to move the moving load vertically up and down, and the angle sensor measures the rotation angle of the ball screw.

[0015] As a further technical solution of the present invention, a depth sensor is provided at the center of the upper shell of the main body.

[0016] Another object of the present invention is to provide a method for controlling the attitude of an underwater helicopter with an attitude regulator. The method is implemented based on the above-mentioned underwater helicopter with an attitude regulator. The method comprises the following steps:

[0017] Using Position Vectors Describes the positions of the upper floating block, lower floating block, and moving load in the body coordinate system, where: Represents the buoyancy block and Radius of rotation;

[0018] ;

[0019] Indicates a floating block. The volume of the lower floating block, upper floating block and lower floating block is and , the mass is negligible and is used for horizontal buoyancy adjustment; represents the moving load, with a mass of , used for vertical center of gravity adjustment, they are represented as mobile mass particles, , Represents blocks along the axis ox axis, oy Axis and oz Position in the axial direction;

[0020] Position vector of the center of gravity and the position vector of the center of buoyancy It is determined by the positions of the upper floating block, lower floating block and moving load and is expressed as:

[0021] ;

[0022] ;

[0023] in, m rb , V rb， r rb Represent the mass, inertia and position vector of the rigid body respectively;

[0024] and The masses of are negligible and their volumes are the same: ,but and Simplified to;

[0025] ;

[0026] ;

[0027] Where B is approximately equal to W. When the underwater helicopter is at rest, the applied torque is zero, and the static state can be obtained. and The formula for the angle is:

[0028] ;

[0029] Finding the inverse function yields:

[0030] ;

[0031] The posture adjustment strategy is divided into two stages;

[0032] Phase 1: Avoiding Adjustments , but move and ;Keep At rest in the lowest position, ensuring that the horizontal thrusters and the center of gravity are aligned in the same plane, we obtain:

[0033] ;

[0034] in , ;when hour, and does not produce a solution, so in the first stage, and has a maximum solution; subsequently, it transitions to the second stage, where the attitude is adjusted by manipulating the center of gravity position;

[0035] Phase 2: Adjustment 、 and location, while ensuring equal ,get:

[0036] .

[0037] Through the first and second stages, the attitude regulator enables ARAUH to achieve pitch and roll angles from -90 degrees to 90 degrees; the servo motors adjust the pitch and roll angles according to the required angles. and , and adjust the position of the moving block according to the feedback from the encoder.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1. The highly efficient posture adjustment mechanism has excellent capabilities and is designed to achieve precise and flexible adjustment of any complex posture, ensuring the long-term stability and high reliability of the mechanism's operation.

[0040] 2. Adopting a leading autonomous control system with higher autonomy and intelligent adaptability, it can adjust in real time according to the changing environment to ensure efficient operation and good adaptability of the organization.

[0041] 3. It has excellent stability and reliability, and can cope with various complex underwater environmental challenges, ensuring that the organization maintains stable operation under extreme conditions and ensuring the smooth execution of missions.

[0042] 4. Through effective energy management and system optimization design, energy consumption can be reduced, the efficiency and versatility of the organization's mission execution can be improved, and it can have excellent performance and long-term performance in various underwater missions. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 An exploded view of an underwater helicopter with an attitude adjuster provided in an embodiment of the present invention.

[0044] Figure 2 A schematic diagram of a buoyancy center adjustment structure of an underwater helicopter with an attitude adjuster provided in an embodiment of the present invention.

[0045] Figure 3 A schematic diagram of a center of gravity adjustment structure of an underwater helicopter with an attitude adjuster provided in an embodiment of the present invention.

[0046] Figure 4 This is a schematic diagram of the attitude adjuster provided in an embodiment of the present invention.

[0047] Notes on the figure numbers: 1-upper shell, 2-electronic cabin, 3-thruster, 4-lower shell, 501-lower floating block, 502-upper floating block, 503-lower ball bearing, 504-upper ball bearing, 505-waterproof servo motor, 506-encoder, 6-support, 7-aluminum ring, 801-skeleton, 802-angle sensor, 803-moving load, 804-screw, 805-ball screw, 806-linear bearing, 807-servo motor, 808-posture sensor, 9-depth sensor. DETAILED DESCRIPTION

[0048] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0049] See also Figures 1 to 3 As an embodiment of the present invention, an underwater helicopter with an attitude regulator includes: a waterproof electronic cabin 2, a support 6, an attitude regulation system, a propulsion system, an upper shell 1 and a lower shell 4:

[0050] The upper shell 1, the lower shell 4 and the aluminum ring 7 are fixed to the upper and lower ends of the support 6 by bolts to form a main shell. The main shell is a flat disc-shaped structure. The main shell is disc-shaped, and has low damping motion when moving horizontally, high damping motion when moving vertically, and approximately zero damping motion when rotating around the axis. The propulsion system includes two horizontal thrusters 3 and four vertical thrusters 3 and a motor speed regulator for controlling the thruster speed. The two horizontal thrusters 3 are respectively located on the left and right sides of the underwater helicopter, and the four vertical thrusters 3 are fixed on the support 6; the waterproof electronic cabin 2 is fixed at the center of the support 6.

[0051] In this embodiment, the posture adjustment system includes a buoyancy center adjustment structure and a gravity center adjustment structure.

[0052] In this embodiment, the buoyancy center adjustment structure includes an upper ball bearing 504, a lower ball bearing 503, two waterproof servo motors 505, two encoders 506, an upper floating block 502 and a lower floating block 501;

[0053] Among them, the outer rings of the upper ball bearing 504 and the lower ball bearing 503, the waterproof servo motor 505 and the encoder 506 are all fixed on the support frame 6, and the upper and lower floating blocks are respectively fixed on the inner rings of the upper ball bearing 504 and the lower ball bearing 503; the inner rings of the ball bearings are driven by two waterproof servo motors 505 through gears, so that the floating blocks installed on the inner rings rotate with the inner rings; the two encoders 506 respectively measure the rotation angles of the inner rings of the upper and lower ball bearings, thereby forming a closed-loop control of the horizontal position of the center of buoyancy of the underwater helicopter.

[0054] In this embodiment, the center of gravity adjustment structure includes a skeleton 801, an angle sensor 802, a movable load 803, a screw 804, a ball screw 805, a linear bearing 806, a servo motor 807 and a posture sensor 808;

[0055] The frame 801 is fixed to the aluminum ring 7, and the angle sensor 802, the screw rod 804 and the servo motor 807 are all fixed to the frame 801;

[0056] The movable load 803 and the linear bearing 806 are fixed together and move vertically up and down following the screw 804; the servo motor 807 drives the ball screw 805 through the gear set to move the movable load 803 vertically up and down, and the angle sensor 802 measures the rotation angle of the ball screw 805, thereby controlling the center of gravity in a closed loop in the vertical direction.

[0057] In this embodiment, a depth sensor 9 is provided at the center of the upper shell 1 of the main body, so as to measure the depth of the underwater helicopter in real time.

[0058] Another object of an embodiment of the present invention is to provide a method for controlling the attitude of an underwater helicopter with an attitude regulator. The method is implemented based on the above-mentioned underwater helicopter with an attitude regulator, and the method comprises the following steps:

[0059] The principle of the attitude regulator can be Figure 4 Represented using the position vector Describes the positions of the upper floating block, lower floating block, and moving load in the body coordinate system, where: Represents the buoyancy block and Radius of rotation;

[0060] ;

[0061] Indicates a floating block. The volume of the lower floating block, upper floating block and lower floating block is and , the mass is negligible and is used for horizontal buoyancy adjustment; represents the moving load, with a mass of , used for vertical center of gravity adjustment, they are represented as mobile mass particles, , Represents blocks along the axis ox axis, oy Axis and oz Position in the axial direction;

[0062] Position vector of the center of gravity and the position vector of the center of buoyancy It is determined by the positions of the upper floating block, lower floating block and moving load and is expressed as:

[0063] ;

[0064] ;

[0065] in, m rb , V rb， r rb Represent the mass, inertia and position vector of the rigid body respectively;

[0066] and The masses of are negligible and their volumes are the same: ,but and Simplified to;

[0067] ;

[0068] ;

[0069] Where B is approximately equal to W. When the underwater helicopter is at rest, the applied torque is zero, and the static state can be obtained. and The formula for the angle is:

[0070] ;

[0071] Finding the inverse function yields:

[0072] ;

[0073] The posture adjustment strategy is divided into two stages;

[0074] Phase 1: Avoiding Adjustments , but move and ;Keep At rest in the lowest position, ensuring that the horizontal thrusters and the center of gravity are aligned in the same plane, we obtain:

[0075] ;

[0076] in , ;when hour, and does not produce a solution, so in the first stage, and has a maximum solution; subsequently, it transitions to the second stage, where the attitude is adjusted by manipulating the center of gravity position;

[0077] Phase 2: Adjustment 、 and location, while ensuring equal ,get:

[0078] .

[0079] Through the first and second stages, the attitude regulator enables ARAUH to achieve pitch and roll angles from -90 degrees to 90 degrees; the servo motors adjust the pitch and roll angles according to the required angles. and , and adjust the position of the moving block according to the feedback from the encoder.

[0080] It should be understood that for ordinary technicians in this field, they can improve or transform the principles of the present invention and the above description, or apply the method provided by the present invention to similar underwater robot posture control tasks, and all these improvements and transformations should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for controlling the attitude of an underwater helicopter with an attitude regulator, characterized in that: The attitude control method is implemented based on an underwater helicopter with an attitude regulator, and the attitude control method includes the following steps: Use the position vector r p1 、r p2 and r p3 Describes the positions of the upper and lower floating blocks and the moving load in the body coordinate system, where l represents the rotation radius of p1 and p2 of the upper and lower floating blocks; p1 represents the upper floating block, p2 represents the lower floating block, the volumes of the upper and lower floating blocks are V1 and V2, and their masses are negligible, which are used to adjust the horizontal buoyancy center; p3 represents the moving load, and the mass of the moving load is m3, which is used to adjust the vertical center of gravity, x i ,y i , z i Represent the positions of p1, p2 and p3 along the ox axis, oy axis and oz axis respectively; The position vector r of the center of gravity CG and the position vector r of the center of buoyancy CB It is determined by the positions of the upper floating block, lower floating block and moving load and is expressed as: Among them, m rb , V rb， r rb Represent the mass, volume and position vector of the rigid body respectively; The masses of p1 and p2 are negligible, and their volumes are the same: V1 = V2 = V c , then r CG and r CB Simplified to; The buoyancy B is approximately equal to the gravity W. When the underwater helicopter is at rest, the applied torque is zero, and the roll angle in the static state can be obtained as and pitch angle θ s The formula is expressed as: Finding the inverse function yields: The posture adjustment strategy is divided into two stages; Phase 1: Avoid adjusting p3 and instead move p1 and p2; keep p3 stationary at the bottom, ensuring that the horizontal thrusters and the center of gravity are aligned in the same plane, resulting in: in when-a 2 -b 2 When +4<0, α1 and α2 do not produce solutions, so in the first stage, and θ s has a maximum solution; subsequently, it transitions to the second stage, where the attitude is adjusted by manipulating the center of gravity position; Phase 2: Adjust the positions of p1, p2, and p3 while ensuring that α1 is equal to α2, obtaining: The underwater helicopter includes: waterproof electronic cabin, support parts, attitude adjustment system, propulsion system, upper shell and lower shell: The upper and lower shells and the aluminum ring are fixed to the upper and lower ends of the support by bolts to form the main body shell. The propulsion system includes two horizontal thrusters and four vertical thrusters and a motor speed regulator for controlling the thruster speed. The two horizontal thrusters are respectively located on the left and right sides of the underwater helicopter, and the four vertical thrusters are fixed to the support. The waterproof electronic cabin is fixed to the center of the support. The posture adjustment system includes a buoyancy center adjustment structure and a gravity center adjustment structure; The buoyancy center adjustment structure includes an upper ball bearing, a lower ball bearing, two waterproof servo motors, two encoders, an upper floating block and a lower floating block; The outer rings of the upper and lower ball bearings, the waterproof servo motor, and the encoder are all fixed to the support frame. The upper and lower floats are respectively fixed to the inner rings of the upper and lower ball bearings. The inner rings of the ball bearings are driven by two waterproof servo motors through gears, so that the floats installed on the inner rings rotate with the inner rings. The two encoders respectively measure the rotation angles of the inner rings of the upper and lower ball bearings. The center of gravity adjustment structure includes a skeleton, an angle sensor, a movable load, a screw, a ball screw, a linear bearing, a servo motor and a posture sensor; The frame is fixed to the aluminum ring, and the angle sensor, lead screw and servo motor are all fixed to the frame; The moving load and the linear bearing are fixed together and move vertically up and down with the screw. The servo motor drives the ball screw through the gear set to move the moving load vertically up and down, and the angle sensor measures the rotation angle of the ball screw. A depth sensor is provided at the center of the upper shell of the main body; The main body shell is a flat dish-shaped structure.

Images