scholarly journals Underwater Docking Approach and Homing to Enable Persistent Operation

2021 ◽  
Vol 8 ◽  
Author(s):  
Brian R. Page ◽  
Reeve Lambert ◽  
Jalil Chavez‐Galaviz ◽  
Nina Mahmoudian
Keyword(s):  
Experimental Testing ◽  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Limiting Factors ◽  
Underwater Communication ◽  
Energy Sustainability ◽  
Underwater Docking ◽  
Docking Approach ◽  
Vehicle Position ◽  
Ocean Environment

One of the main limiting factors in deployment of marine robots is the issue of energy sustainability. This is particularly challenging for traditional propeller-driven autonomous underwater vehicles which operate using energy intensive thrusters. One emerging technology to enable persistent performance is the use of autonomous recharging and retasking through underwater docking stations. This paper presents an integrated navigational algorithm to facilitate reliable underwater docking of autonomous underwater vehicles. Specifically, the algorithm dynamically re-plans Dubins paths to create an efficient trajectory from the current vehicle position through approach into terminal homing. The path is followed using integral line of sight control until handoff to the terminal homing method. A light tracking algorithm drives the vehicle from the handoff location into the dock. In experimental testing using an Oceanserver Iver3 and Bluefin SandShark, the approach phase reached the target handoff within 2 m in 48 of 48 tests. The terminal homing phase was capable of handling up to 5 m offsets with approximately 70% accuracy (12 of 17 tests). In the event of failed docking, a Dubins path is generated to efficiently drive the vehicle to re-attempt docking. The vehicle should be able to successfully dock in the majority of foreseeable scenarios when re-attempts are considered. This method, when combined with recent work on docking station design, intelligent cooperative path planning, underwater communication, and underwater power transfer, will enable true persistent undersea operation in the extremely dynamic ocean environment.

scholarly journals Sensors to Increase the Security of Underwater Communication Cables: A Review of Underwater Monitoring Sensors

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 737 ◽  
Author(s):  
Dimitrios Eleftherakis ◽  
Raul Vicen-Bueno
Keyword(s):  
Operational Research ◽  
Research Study ◽  
Critical Infrastructure ◽  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Decision Makers ◽  
Sensitive Information ◽  
Underwater Communication ◽  
Unmanned Surface Vehicles ◽  
Water Depths

Underwater communication cables transport large amounts of sensitive information between countries. This fact converts these cables into a critical infrastructure that must be protected. Monitoring the underwater cable environment is rare and any intervention is usually driven by cable faults. In the last few years, several reports raised issues about possible future malicious attacks on such cables. The main objective of this operational research and analysis (ORA) paper is to present an overview of different commercial and already available marine sensor technologies (acoustic, optic, magnetic and oceanographic) that could be used for autonomous monitoring of the underwater cable environment. These sensors could be mounted on different autonomous platforms, such as unmanned surface vehicles (USVs) or autonomous underwater vehicles (AUVs). This paper analyses a multi-threat sabotage scenario where surveying a transatlantic cable of 13,000 km, (reaching water depths up to 4000 m) is necessary. The potential underwater threats identified for such a scenario are: divers, anchors, fishing trawls, submarines, remotely operated vehicles (ROVs) and AUVs. The paper discusses the capabilities of the identified sensors to detect such identified threats for the scenario under study. It also presents ideas on the construction of periodic and permanent surveillance networks. Research study and results are focused on providing useful information to decision-makers in charge of designing surveillance capabilities to secure underwater communication cables.

scholarly journals Wireless Remote Control for Underwater Vehicles

2020 ◽  
Vol 8 (10) ◽  
pp. 736
Author(s):  
Filippo Campagnaro ◽  
Alberto Signori ◽  
Michele Zorzi
Keyword(s):  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Communication Link ◽  
Strong Impact ◽  
Underwater Sensor Networks ◽  
Navigation Systems ◽  
Underwater Communication ◽  
Commercial Off The Shelf ◽  
The Stability ◽  
New Applications

Nowadays, the increasing availability of commercial off-the-shelf underwater acoustic and non-acoustic (e.g., optical and electromagnetic) modems that can be employed for both short-range broadband and long-range low-rate communication, the increasing level of autonomy of underwater vehicles, and the refinement of their underwater navigation systems pave the way for several new applications, such as data muling from underwater sensor networks and the transmission of real-time video streams underwater. In addition, these new developments inspired many companies to start designing hybrid wireless-driven underwater vehicles specifically tailored for off-shore operations and that are able to behave either as remotely operated vehicles (ROVs) or as autonomous underwater vehicles (AUVs), depending on both the type of mission they are required to perform and the limitations imposed by underwater communication channels. In this paper, we evaluate the actual quality of service (QoS) achievable with an underwater wireless-piloted vehicle, addressing the realistic aspects found in the underwater domain, first reviewing the current state-of-the-art of communication technologies and then proposing the list of application streams needed for control of the underwater vehicle, grouping them in different working modes according to the level of autonomy required by the off-shore mission. The proposed system is finally evaluated by employing the DESERT Underwater simulation framework by specifically analyzing the QoS that can be provided to each application stream when using a multimodal underwater communication system specifically designed to support different traffic-based QoSs. Both the analysis and the results show that changes in the underwater environment have a strong impact on the range and on the stability of the communication link.

A regressor-free robust adaptive controller for autonomous underwater vehicles

2016 ◽  
Vol 231 (2) ◽  
pp. 569-582 ◽  
Author(s):  
Reza Dehghani ◽  
Heshmatallah Mohammad Khanlo
Keyword(s):  
Dynamic Model ◽  
Autonomous Underwater Vehicle ◽  
Autonomous Underwater Vehicles ◽  
External Disturbance ◽  
Adaptive Controller ◽  
Underwater Vehicles ◽  
Inverse Dynamic ◽  
Robust Adaptive ◽  
Ocean Environment ◽  
Robust Adaptive Controller

This article focuses on the motion control of autonomous underwater vehicles in the ocean environment by a robust adaptive controller in which there is no regressor matrix. Due to the different atmospheric conditions in the ocean environment, the hydrodynamic coefficients of autonomous underwater vehicles cannot be exactly available and there are many uncertainties in the dynamic model. This prevents the traditional controllers to overcome these difficulties immediately. Hence, developing the adaptive controllers for the autonomous underwater vehicles encountered with uncertainties is required to provide appropriate performance. In the conventional adaptive control system, it is assumed that the autonomous underwater vehicle dynamic model can be linearly written into regressor form. Since the dynamics of the underwater vehicles is very complex, the derivation of the regressor matrix is very tedious. To overcome these problems, a regressor-free adaptive controller is proposed for the autonomous underwater vehicles in the general form of the equations of motion. In this approach, the controller is derived by the inverse dynamic method. Also, by utilizing known basis functions weighted by constant unknown coefficients, the uncertainties of the control law are estimated. The adaptation laws are derived based on Lyapunov stability theorem. The validity of the proposed method is verified by some simulation experiments. The simulation results show that the proposed approach can improve the robustness of adaptive controller to the dynamic model uncertainties and the external disturbance.

scholarly journals Cooperative path planning of multiple autonomous underwater vehicles operating in dynamic ocean environment

2019 ◽  
Vol 94 ◽  
pp. 174-186 ◽  
Author(s):  
Yufei Zhuang ◽  
Haibin Huang ◽  
Sanjay Sharma ◽  
Dianguo Xu ◽  
Qiang Zhang
Keyword(s):  
Path Planning ◽  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Ocean Environment

Hybrid Underwater Glider for Underwater Docking: Modeling and Performance Evaluation

2014 ◽  
Vol 48 (6) ◽  
pp. 112-124 ◽  
Author(s):  
Shilin Peng ◽  
Canjun Yang ◽  
Shuangshuang Fan ◽  
Shaoyong Zhang ◽  
Pinfu Wang ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Autonomous Underwater Vehicles ◽  
Experimental Tests ◽  
Underwater Vehicles ◽  
Open Loop ◽  
Hydrodynamic Coefficients ◽  
Underwater Glider ◽  
Underwater Docking ◽  
Motion Performance ◽  
And Performance

AbstractThe development of a novel type of hybrid underwater glider that combines the advantages of buoyancy-driven gliders and propeller-driven autonomous underwater vehicles has recently received considerable interest. However, few studies have considered a hybrid glider with docking capability, which would expand the glider's applications. This study presents a hybrid glider with a rotatable thruster for realizing underwater docking. A tailored dynamic model of the hybrid glider is derived, and the motion performance is evaluated by simulations and experimental tests. A comparison between the experiments and simulations shows that results are in agreement, thus indicating the feasibility of the dynamic model and the accuracy of the hydrodynamic coefficients. In addition, the hybrid glider open-loop docking tests validate the feasibility of the mechanical docking system. Moreover, the experimental tests also validate the glider's different functions and indicate that the hybrid glider with rotatable thruster has high maneuverability even at low speeds. Thus, this type of hybrid glider can be used for underwater docking.

scholarly journals Simulation model for energy consumption and acoustic underwater communication of autonomous underwater vehicles

2021 ◽  
Author(s):  
Peter Danielis ◽  
Helge Parzyjegla ◽  
Mostafa Assem Mohamed Ali ◽  
Frank Sill Torres
Keyword(s):  
Energy Consumption ◽  
Simulation Model ◽  
Acoustic Communication ◽  
Acoustic Waves ◽  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Underwater Acoustic Communication ◽  
Network Simulator ◽  
Underwater Communication ◽  
Underwater Acoustic

AbstractRecently, cooperative autonomous underwater vehicles (AUVs) have been deployed in application areas such as surveillance and protection of maritime infrastructures for inspection and monitoring purposes. These cooperative methodologies require wireless transmission of data between the different AUVs operating in the underwater environment. Communication over ranges exceeding 100 m exclusively relies on underwater acoustic communication. However, the propagating acoustic waves suffer from several challenges due to the presence of path loss, multi-path propagation, the slow and variant propagation speed, background noise, and Doppler distortion. Since the power supply of the AUVs is limited, communication must be very energy efficient and energy constraints have to be known to be able to plan the mission of AUVs. Due to the difficulties of real experiments, the modeling and simulation of the energy consumption and underwater acoustic communication play an essential role in studying and developing these systems. We provide a modular simulation model for the energy consumption and acoustic underwater communication of AUVs implemented in the network simulator OMNeT++ using the INET framework. More specifically, we extend several INET modules in such a way as to reflect the characteristics of AUVs and underwater communication. We study and analyze the AUVs’ energy consumption and dependence of the message quality on different properties such as those mentioned above.

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