Underwater omnidirectional motion AUV design and control method

Abstract

The invention relates to the technical field of AUV (Autonomous Underwater Vehicle) control, in particular to an underwater omnidirectional motion AUV design and control method, which is characterized in that power units such as an actuator in an AUV are specially designed, a system is controlled and decoupled to a certain extent, and underwater omnidirectional motion of the AUV is realized by combining a hybrid control technology. According to the method, the design advantages of the original low-resistance streamline torpedo-shaped structure of the AUV are reserved, the underwater omnidirectional motion capability of the AUV is given, the underwater maneuverability of the AUV is greatly improved, and the actual application scene of the AUV is expanded.

Description

Technical Field

[0001] The present invention relates to the technical field of AUV control, and specifically to a design and control method for an underwater omnidirectional motion AUV. Background Art

[0002] As an underwater detection device, the AUV underwater vehicle is widely used in fields such as ocean exploration, environmental monitoring, and military reconnaissance. However, the current underwater vehicle cannot meet the requirements in special environments in terms of flexibility control. Summary of the Invention

[0003] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a design and control method for an underwater omnidirectional motion AUV.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A design and control method for an underwater omnidirectional motion AUV, and its steps are as follows:

[0005] (1) Conduct the fuselage design for the underwater omnidirectional motion AUV, including setting an independent power cabin section at the bow section of the AUV, setting an independent power cabin section at the stern section of the AUV, setting an independent power cabin section at the center of gravity position of the AUV, and setting an independent power cabin section near the center of gravity position of the AUV;

[0006] (2) The AUV obtains the target input from the upper computer, including the target position [x r , y r , z r , the target attitude [φ r , θ r , ψ r , the AUV obtains the current position [x0, y0, z0] from the sensing system, and the current attitude [φ0, θ0, ψ0];

[0007] (3) According to the current depth z0 and the target depth z r , use the buoyancy device to cooperate with the fuzzy algorithm or other equivalent control algorithms to achieve depth regulation;

[0008] (4) According to the current pitch angle θ0 and the target pitch angle θ r , use the center of gravity adjustment device to cooperate with the PID control algorithm or other equivalent control algorithms to achieve pitch regulation;

[0009] (5) According to the current roll angle φ0 and the target roll angle φ r , use the rudder surface to cooperate with the PID control algorithm or other equivalent control algorithms to achieve roll regulation (generally not involved, the AUV ensures that the roll angle is 0 through structural design);

[0010] (6) According to the current position and the target position, obtain the position error [e x , ey , e z , and perform coordinate transformation to the position error in the AUV body coordinate system [e xb , e yb , e zb ;

[0011] (7) According to the position error [e xb , e yb , e zb in the body coordinate system, realize yaw and horizontal displacement control through the AUV omnidirectional hybrid control algorithm and the bow and stern thrusters.

[0012] In some embodiments, according to step (1), the specific structure of its fuselage power cabin is as follows:

[0013] (1) Set an independent power cabin section at the bow of the AUV. This power cabin section contains an underwater thruster placed horizontally, which is used for forward and reverse thrust delivery and is called the bow thruster;

[0014] (2) Set an independent power cabin section at the stern of the AUV. This power cabin section contains an underwater thruster placed horizontally, which is used for forward and reverse thrust delivery and is called the stern thruster;

[0015] (3) Set an independent power cabin section at the center of gravity position of the AUV. This power cabin section contains a center of gravity adjustment device, which is used for the center of gravity of the AUV to move back and forth along the body;

[0016] (4) Set an independent power cabin section near the center of gravity position of the AUV. This power cabin section contains a buoyancy device, which is used for increasing or decreasing buoyancy.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] 1. The present invention realizes the underwater omnidirectional movement of the AUV, greatly improves the underwater maneuverability of the AUV, and expands the application scenarios of the AUV.

[0019] 2. While realizing the ability of underwater omnidirectional movement, the present invention still retains the advantages of the original low-drag streamline torpedo-shaped structure design of the AUV, so that the AUV does not lose its original motion mode.

[0020] The details of one or more embodiments of this application are presented in the following drawings and descriptions, so that other features, purposes, and advantages of this application are more concise and understandable. The present application is described in detail and understood through the embodiments of this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the omnidirectional AUV structure design of the present invention;

[0022] Figure 2 is the omnidirectional hybrid control schematic diagram of the present invention;

[0023] Figure 3 is the schematic diagram of the omnidirectional hybrid control algorithm framework of the present invention. Specific embodiments

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0025] Please refer to Figures 1-3 , the present invention provides a technical solution: a design and control method for an underwater omnidirectional motion AUV. This AUV adopts a modular cabin section design. As Figure 1 shown, its fuselage power cabin section is specifically:

[0026] (1) An independent power cabin section is provided at the bow section of the AUV. This power cabin section includes an underwater thruster placed horizontally, which is used for forward and reverse thrust transmission and is called the bow thruster;

[0027] (2) An independent power cabin section is provided at the stern section of the AUV. This power cabin section includes an underwater thruster placed horizontally, which is used for forward and reverse thrust transmission and is called the stern thruster;

[0028] (3) An independent power cabin section is provided at the center of gravity position of the AUV. This power cabin section includes a center of gravity adjustment device, which is used for the center of gravity of the AUV to move forward and backward along the body;

[0029] (4) An independent power cabin section is provided near the center of gravity position of the AUV. This power cabin section includes a buoyancy device, which is used for increasing or decreasing buoyancy.

[0030] Through this technical solution, in order to ensure that a large enough yaw moment can be generated, the bow thruster and the stern section should be placed as far away from the center of gravity as possible. The bow and stern thrusters do not have to be strictly symmetric about the center of gravity;

[0031] The buoyancy device is placed near the center of gravity position to ensure that the pitch moment generated by the buoyancy change is as small as possible and can be balanced by the center of gravity adjustment device;

[0032] It is required that the design of the buoyancy / center of gravity device ensures that the center of buoyancy is always above the center of gravity, so that the roll angle is 0;

[0033] Target position [x r , y r , z rWith the target attitude [φ r , θ r , ψ r input by the user on the host computer, the current position [x0, y0, z0] and the current attitude [φ0, θ0, ψ0] are obtained by the sensor and filtered.

[0034] Due to the special structural design of this AUV, partial motion control decoupling has been achieved. The motion variables can be directly associated and mapped between actuators, and PID or other equivalent closed-loop control algorithms are used for control.

[0035] As Figure 2 shown, the omnidirectional hybrid control of the AUV is the hybrid control of yaw and lateral movement, and the actuators are the bow and stern thrusters. The specific method is to realize the motion control along the y-axis direction of the body through the coordinated movement of the two thrusters, and realize the yaw angle control through differential movement. Finally, the two groups of signals are superimposed and output, and compensated and sent to the actuator to realize the synchronous movement of the AUV's yaw and lateral movement. When there is a pitch angle, the depth disturbance caused by the tail thruster actuation can be automatically compensated and adjusted by the depth control loop of the buoyancy device.

[0036] As Figure 3 shown is the algorithm block diagram of the AUV's omnidirectional hybrid control.

[0037] (1) Obtain the current position, attitude and the target position, attitude from the sensor and the host computer respectively, calculate the position error [e x , e y , e z and the attitude error [e φ , e θ , e ψ , and perform coordinate transformation to the position error [e xb , e yb , e zb in the AUV body coordinate system.

[0038] (2) Obtain the control outputs

[0039] respectively through the angle controller and the lateral position controller in the hybrid control framework.

[0040] The above embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several variations and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

[0041] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A design and control method for an underwater omnidirectional AUV, characterized by: The steps are: (1) Designing the fuselage of the underwater omnidirectional AUV, including setting an independent power compartment at the bow section of the AUV, setting an independent power compartment at the stern section of the AUV, setting an independent power compartment at the center of gravity of the AUV, and setting an independent power compartment near the center of gravity of the AUV; (2) The AUV obtains target input from the host computer, including the target position [x r ,y r ,z r ], target posture [φ r ,θ r ,ψ r ], the AUV obtains the current position [x0, y0, z0] and the current attitude [φ0, θ0, ψ0] by the sensor system; (3) According to the current depth z0 and the target depth z r , use buoyancy device with fuzzy algorithm or other equivalent control algorithm to achieve depth control; (4) According to the current pitch angle θ0 and the target pitch angle θ r , use the center of gravity adjustment device in conjunction with the PID control algorithm or other equivalent control algorithms to achieve pitch control; (5) According to the current roll angle φ0 and the target roll angle φ r , use the rudder with PID control algorithm or other equivalent control algorithm to achieve roll control; (6) According to the current position and the target position, the position error [e x ,e y ,e z ], and transform the coordinates to the position error [e xb ,e yb ,e zb ]; (7) According to the position error of the machine system [e xb ,e yb ,e zb ], yaw and horizontal displacement control is achieved through the AUV omnidirectional hybrid control algorithm and bow and stern thrusters.

2. The design and control method of an underwater omnidirectional AUV according to claim 1, characterized in that: According to step (1), the fuselage power compartment section is specifically: (1) An independent power compartment is set at the bow section of the AUV. The power compartment includes a horizontally placed underwater thruster, which is used for forward and reverse thrust transmission and is called bow thruster. (2) An independent power compartment is set at the stern of the AUV. The power compartment includes a horizontally placed underwater thruster, which is used for forward and reverse thrust transmission, called stern thruster; (3) An independent power compartment is provided at the center of gravity of the AUV, and the power compartment includes a center of gravity adjustment device, and the center of gravity adjustment device is used for the AUV center of gravity to move forward and backward along the body; (4) An independent power compartment is arranged near the center of gravity of the AUV, and the power compartment includes a buoyancy device, which is used to increase or decrease the buoyancy.

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