scholarly journals Active Fault Localization of Actuators on Torpedo-Shaped Autonomous Underwater Vehicles

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 476
Author(s):  
Fuqiang Liu ◽  
Yan Long ◽  
Jun Luo ◽  
Huayan Pu ◽  
Chaoqun Duan ◽  
...  
Keyword(s):  
Attitude Control ◽  
Fault Location ◽  
Control Strategies ◽  
Autonomous Underwater Vehicles ◽  
Fault Localization ◽  
Underwater Vehicles ◽  
Element Analysis ◽  
Fault Features ◽  
Fault Parameters ◽  
Actuator Control

To ensure the mission implementation of Autonomous Underwater Vehicles (AUVs), faults occurring on actuators should be detected and located promptly; therefore, reliable control strategies and inputs can be effectively provided. In this paper, faults occurring on the propulsion and attitude control systems of a torpedo-shaped AUV are analyzed and located while fault features may induce confusions for conventional fault localization (FL). Selective features of defined fault parameters are assorted as necessary conditions against different faulty actuators and synthesized in a fault tree subsequently to state the sufficiency towards possible abnormal parts. By matching fault features with those of estimated fault parameters, suspected faulty sections are located. Thereafter, active FL strategies that analyze the related fault parameters after executing purposive actuator control are proposed to provide precise fault location. Moreover, the generality of the proposed methods is analyzed to support extensive implementations. Simulations based on finite element analysis against a torpedo-shaped AUV with actuator faults are carried out to illustrate the effectiveness of the proposed methods.

scholarly journals Advanced Autonomous Underwater Vehicles Attitude Control with L 1 Backstepping Adaptive Control Strategy

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4848
Author(s):  
Yuqian Liu ◽  
Jiaxing Che ◽  
Chengyu Cao
Keyword(s):  
Adaptive Control ◽  
Control Strategy ◽  
Attitude Control ◽  
Autonomous Underwater Vehicles ◽  
Euler Angle ◽  
Underwater Vehicles ◽  
Linearization Method ◽  
Backstepping Control ◽  
Feedback Form ◽  
Adaptive Control Strategy

This paper presents a novel attitude control design, which combines L 1 adaptive control and backstepping control together, for Autonomous Underwater Vehicles (AUVs) in a highly dynamic and uncertain environment. The Euler angle representation is adopted in this paper to represent the attitude propagation. Kinematics and dynamics of the attitude are in the strict feedback form, which leads the backstepping control strategy serving as the baseline controller. Moreover, by bringing fast and robust adaptation into the backstepping control architecture, our controller is capable of dealing with time-varying uncertainties from modeling and external disturbances in dynamics. This attitude controller is proposed for coupled pitch-yaw channels. For inevitable roll excursions, a Lyapunov function-based optimum linearization method is presented to analyze the stability of the roll angle in the operation region. Theoretical analysis and simulation results are given to demonstrate the feasibility of the developed control strategy.

scholarly journals Application of Shielding Coils in Underwater Wireless Power Transfer Systems

2019 ◽  
Vol 7 (8) ◽  
pp. 267
Author(s):  
Wang ◽  
Song ◽  
Mao
Keyword(s):  
Autonomous Underwater Vehicles ◽  
Wireless Power Transfer ◽  
Underwater Vehicles ◽  
Transfer Efficiency ◽  
Maximum Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Power Transfer Efficiency

Underwater wireless power transfer (WPT) technology can enhance the endurance of the autonomous underwater vehicles (AUV). WPT that based on electromagnetic theory will generate eddy current loss (ECL) in seawater. In this paper, we make use of shielding coils to weaken the electromagnetic field (EMF) in seawater, which can reduce ECL and improve the transfer efficiency. Simplified circuit models were proposed to provide an intuitive and comprehensive analysis of the transfer efficiency and the finite element analysis (FEA) was used to simulate the distribution of EMF. We learn that the system with shielding coils performs better when the operating frequency is relatively high by comparing the power transfer efficiency of the underwater WPT systems with and without the shielding, and its maximum efficiency is higher than the system without shielding. The effect of the shielding coils has the similar influence when compared with the metallic plate. While considering the efficiency and weight of coils, the results show that the shielding coils can be used in the underwater WPT system to improve the power transfer efficiency.

Thruster Interactions on Autonomous Underwater Vehicles

2009 ◽  
Author(s):  
Alistair R. Palmer ◽  
Grant E. Hearn ◽  
Peter Stevenson
Keyword(s):  
Hydrodynamic Interaction ◽  
Control Strategies ◽  
Dynamic Performance ◽  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Interaction Effects ◽  
Dynamic Positioning ◽  
Surface Vessels ◽  
Control Devices ◽  
And Control

Autonomous underwater vehicles are a developing technology capable of undertaking a wide variety of different tasks. The development of these vehicles is aided by the use of simulations of their performance. These simulations require accurate modelling of the propulsion and control devices employed to calculate the response of a vehicle to different situations and control strategies. Simulations of underwater vehicles tend to include models of the dynamic performance of the thrusters employed, however, the simulations neglect some of the hydrodynamic interaction effects. These interaction effects include thruster–hull and thruster–thruster interactions similar to those encountered on dynamic positioning surface vessels. This paper assesses these effects for autonomous underwater vehicles and, where appropriate, suggests models for use in simulations.

Model-Based Control and Stability Analysis of Underactuated Autonomous Underwater Vehicles Via Singular Perturbations

2020 ◽  
Vol 15 (6) ◽  
Author(s):  
Ming Lei ◽  
Ye Li
Keyword(s):  
Stability Analysis ◽  
Time Scale ◽  
Control Strategies ◽  
Autonomous Underwater Vehicles ◽  
Path Following ◽  
Underwater Vehicles ◽  
Time Scale Separation ◽  
Independent Analysis ◽  
Effective Performance ◽  
Analysis Of Dynamics

Abstract This paper presents the control design and stability analysis for path-following of underactuated autonomous underwater vehicles (AUVs), with dynamics restricted to the horizontal plane. As illustration, the time-scale separation caused by different rates of numerous variables is exploited via a singular perturbation model formulation. On the basis of that, a time-scale decomposition method is used to decompose the full system into three-time scale subsystems. The three-time scale structure allows independent analysis of dynamics in each time scale. Therefore, control strategies are designed in each subsystem separately, leading to a reduction of control complexity and a relatively simple control law. This paper also demonstrates the asymptotic stability of the closed-loop system with a composite Lyapunov function candidate and provides alternative, simple but generic mathematical bounds on the singularly perturbed parameters. Finally, the simulation results are presented to illustrate the effective performance of proposed controller.

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