This letter studies the problem of autonomous navigation for unmanned underwater vehicles, using computer vision for localization. Parallel tracking and mapping is employed to localize the vehicle with respect to a visual map, using a single camera, whereas an extended Kalman filter (EKF) is used to fuse the visual information with data from an inertial measurement unit, in order to recover the scale of the map and improve the pose estimation. A proportional integral derivative controller controller with compensation of the restoring forces is proposed to accomplish trajectory tracking, where a pressure sensor and a magnetometer provide feedback for depth control and yaw, respectively, while the remaining states are provided by the EKF. Real-time experiments are presented to validate the navigation strategy, using a commercial remotely operated vehicle (ROV), the BlueROV2, which was adapted to perform as an autonomous underwater vehicle with the help of the robot operative system.

Autonomous Navigation for Unmanned Underwater Vehicles: Real-Time Experiments Using Computer Vision

The structure design of an autonomous/remote underwater vehicle, Intelligence Ocean $\mathbf {I}$ (IO- $\mathbf {I}$ ), capable of operating in ROV or AUV mode and acquiring marine environment information and its own status data are outlined first in this paper. The dynamics equations of underwater vehicles in horizontal and vertical are given to describe the movement of an underwater vehicle, taking the gravity, buoyancy, thrust and hydrodynamic force into account. Furthermore, in order to realize high precision automatic control of robot, the fuzzy control algorithm which belongs to the intelligent control is combined with the cascade PID control algorithm to realize an modified underwater vehicle control algorithm, which improves the applicability of the control algorithm and reduces the difficulty and workload of parameter adjustment. The proposed control algorithm is recognized in numerical simulations as well as in experimental tests which confirm the good performance of the controller and the prototype.

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Dynamics Modeling and Motion Control of an New Unmanned Underwater Vehicle

This paper presents an adaptive nonlinear controller for diving control of an autonomous underwater vehicle (AUV). So far, diving dynamics of an AUV has often been derived under various assumptions on the motion of the vehicle. Typically, the pitch angle of AUV has been assumed to be small in the diving plane. However, these kinds of assumptions may induce large modeling errors and further may cause severe problems in many practical applications. In this paper, through a certain simple modification, we break the above restricting condition on the vehicle's pitch angle in diving motion so that the vehicle could take free pitch motion. Proposed adaptive nonlinear controller is designed by using a traditional backstepping method. Finally, certain numerical studies are presented to illustrate the effectiveness of proposed control scheme, and some practical features of the control law are also discussed.

Design of an adaptive nonlinear controller for depth control of an utonomous underwater vehicle

Abstract This paper employs computational tools to investigate the diffraction effects in regular head waves on the added resistance and wake on the propeller plane. The objective ships are a 66,000 DWT bulk carrier and a 3,600 TEU container ship. Fixed and free to heave and pitch conditions at design speed have been taken into account. Two-phase unsteady Reynolds averaged Navier-Stokes equations have been solved using the finite volume method; and a realizable k-e model has been applied for the turbulent closure. The free surface is obtained by solving a VOF equation. The computations are carried out at the same scale of the model tests. Grid and numerical wave damping zones are applied to remove unwanted wave reflection at the boundaries. The computational results are analyzed using the Fourier series. The added resistances in waves at the free condition are higher than those at the fixed condition, which are nearly constant for all wavelengths. The wake velocity in waves is higher than that in calm water, and is accelerated where the wave crest locates on the propeller plane. When the vertical motion at the stern goes upward, the wake velocity also accelerated.

Effects of Diffraction in Regular Head Waves on Added Resistance and Wake Using CFD

Modeling, characterization and control of a piston-driven buoyancy system for a hybrid aerial underwater vehicle

This paper outlines the conception, modeling and control of a rover type modular mini submarine. The development and implementation of the mechanical structure as well as the embedded electronics is described. The onboard instrumentation and sensors required to collect data on the environment and on its own position and orientation are also described. The mathematical representation to describe the movement of an underwater vehicle is analyzed considering the characteristics and limitations of the underwater robot. Furthermore, a control algorithm is implemented based on Lyapunov theory and Backstepping Integral Adaptive (BIA). This control strategy stabilizes the vehicle in position and orientation. The proposed control algorithm is validated in numerical simulations as well as in experimental tests which confirm the good performance of the prototype and the controller.

Design and Control of an Autonomous Underwater Vehicle (AUV-UMI)

A novel underwater vehicle configuration with an operating principle as the Sepiida animal is presented and developed in this paper. The mathematical equations describing the movements of the vehicle are obtained using the Newton–Euler approach. An analysis of the dynamic model is done for control purposes. A prototype and its embedded system are developed for validating analytically and experimentally the proposed mathematical representation. A real-time characterization of one mass is done to relate the pitch angle with the radio of displacement of the mass. In addition, first validation of the closed-loop system is done using a linear controller.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/D038CD609426767E36B60F34033B2271/S0263574720000739a.pdf/div-class-title-design-construction-and-control-for-an-underwater-vehicle-type-sepiida-div.pdf

Miguel Angel Garcia

Papers

Design and Control of an Autonomous Underwater Vehicle (AUV-UMI)

Design, Construction, and Control for an Underwater Vehicle Type Sepiida