scholarly journals WAVE module for hybrid oceanographic Autonomous Underwater Vehicle–prototype experimental validation and characterisation

Author(s):  
A Caiti ◽  
R Costanzi ◽  
D Fenucci ◽  
V Manzari ◽  
A Caffaz ◽  
...  

WAVE (Wave-powered Autonomous Vehicle for marine Exploration) is an Italian National Research Projects of Military interest (PNRM) concluded in October 2017. The final goal of the project was the enhancement of the endurance of a typical marine mission with Autonomous Underwater Vehicles (AUVs). To this aim, a system to provide a generic carrier AUV for both energy harvesting from the wave motion and low energy propulsion capabilities was developed. A first prototype of the WAVE module was realised and installed on a commercial AUVplatform. After a preliminary assessment of the integrated system at sea, a systematic experimental characterisation of the module capabilities was carried out in a controlled environment at the CNR-INSEAN test tank facility in Rome, Italy. During the three days experimentation, a considerable quantity of data related to different recreated sea conditions and WAVE module configurations was collected. This work details the energetic characterisation of the proposed system, presenting a comparison of the performance of the different WAVE module layouts in terms of average generated power. The main result emerged from the previous analysis is the identification of the most effective configuration of the WAVE module for the battery charging. A deeper processing of data will allow to critically tune the available dynamical model of the system. This way, it will be possible to evaluate, through simulations, the expected performance of the WAVE AUV under typical wave profiles of the Mediterranean sea. 

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4551
Author(s):  
Giulia Massaglia ◽  
Adriano Sacco ◽  
Alain Favetto ◽  
Luciano Scaltrito ◽  
Sergio Ferrero ◽  
...  

In the present work, sedimentary microbial fuel cells (s-MFC) have been proposed as effective tools to power remote sensors in different aquatic environments, thanks to their ability to produce renewable and sustainable energy continuously and autonomously. The present work proposes the optimization of cylindrical sedimentary microbial fuel cells (s-MFC) as a compact and cost-effective system suitable to be integrated as a payload in an Autonomous Underwater Vehicle (AUV). To this purpose, a new AUV payload, named MFC-payload, is designed to host the cylindrical s-MFC and a data acquisition system to collect and store information on the voltage produced by the cell. Its overall performance was evaluated during two field measurement campaigns carried out in the Mediterranean Sea. This investigation demonstrates the power production by s-MFC during operation of the AUV in seawater and analyzes the actual influence of environmental conditions on the output power. This study demonstrates that energy production by s-MFCs integrated in AUV systems is decoupled by the navigation of the autonomous vehicle itself, showing the effectiveness of the application of MFC-based technology as a power payload for environmental analysis. All these latter results demonstrate and confirm the ability of the devices to continuously produce electricity during different AUV operation modes (i.e., depth and speed), while changing environmental conditions (i.e., pressure, temperature and oxygen content) demonstrate that cylindrical s-MFC devices are robust system that can be successfully used in underwater applications.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2468
Author(s):  
Ri Lin ◽  
Feng Zhang ◽  
Dejun Li ◽  
Mingwei Lin ◽  
Gengli Zhou ◽  
...  

Docking technology for autonomous underwater vehicles (AUVs) involves energy supply, data exchange and navigation, and plays an important role to extend the endurance of the AUVs. The navigation method used in the transition between AUV homing and docking influences subsequent tasks. How to improve the accuracy of the navigation in this stage is important. However, when using ultra-short baseline (USBL), outliers and slow localization updating rates could possibly cause localization errors. Optical navigation methods using underwater lights and cameras are easily affected by the ambient light. All these may reduce the rate of successful docking. In this paper, research on an improved localization method based on multi-sensor information fusion is carried out. To improve the localization performance of AUVs under motion mutation and light variation conditions, an improved underwater simultaneous localization and mapping algorithm based on ORB features (IU-ORBSALM) is proposed. A nonlinear optimization method is proposed to optimize the scale of monocular visual odometry in IU-ORBSLAM and the AUV pose. Localization tests and five docking missions are executed in a swimming pool. The localization results indicate that the localization accuracy and update rate are both improved. The 100% successful docking rate achieved verifies the feasibility of the proposed localization method.


Author(s):  
Ryan P. Shaw ◽  
David M. Bevly

This paper presents a new approach for the guidance and control of a UGV (Unmanned Ground Vehicle). An obstacle avoidance algorithm was developed using an integrated system involving proportional navigation (PN) and a nonlinear model predictive controller (NMPC). An obstacle avoidance variant of the classical proportional navigation law generates command lateral accelerations to avoid obstacles, while the NMPC is used to track the reference trajectory given by the PN. The NMPC utilizes a lateral vehicle dynamic model. Obstacle avoidance has become a popular area of research for both unmanned aerial vehicles and unmanned ground vehicles. In this application an obstacle avoidance algorithm can take over the control of a vehicle until the obstacle is no longer a threat. The performance of the obstacle avoidance algorithm is evaluated through simulation. Simulation results show a promising approach to conditionally implemented obstacle avoidance.


Author(s):  
Mohammad Saghafi ◽  
Roham Lavimi

In this research, the flow around the autonomous underwater vehicles with symmetrical bodies is numerically investigated. Increasing the drag force in autonomous underwater vehicles increases the energy consumption and decreases the duration of underwater exploration and operations. Therefore, the main objective of this research is to decrease drag force with the change in geometry to reduce energy consumption. In this study, the decreasing or increasing trends of the drag force of axisymmetric bare hulls have been studied by making alterations in the curve equations and creating the optimal geometric shapes in terms of hydrodynamics for the noses and tails of autonomous underwater vehicles. The incompressible, three-dimensional, and steady Navier–Stokes equations have been used to simulate the flow. Also, k-ε Realizable with enhanced wall treatment was used for turbulence modeling. Validation results were acceptable with respect to the 3.6% and 1.4% difference with numerical and experimental results. The results showed that all the autonomous underwater vehicle hulls designed in this study, at an attack angle of 0°, had a lower drag force than the autonomous underwater vehicle hull used for validation except geometry no. 1. In addition, nose no. 3 has been selected as the best nose according to the lowest value of stagnation pressure, and also tail no. 3 has been chosen as the best tail due to the production of the lowest vortex. Therefore, geometry no. 5 has been designed using nose and tail no. 3. The comparison made here showed that the maximum drag reduction in geometry no. 5 was equal to 26%, and therefore, it has been selected as the best bare hull in terms of hydrodynamics.


2018 ◽  
Vol 212 (1) ◽  
pp. 105-123
Author(s):  
Tomasz Praczyk ◽  
Piotr Szymak ◽  
Krzysztof Naus ◽  
Leszek Pietrukaniec ◽  
Stanisław Hożyń

Abstract The paper presents the first part of the final report on all the experiments with biomimetic autono-mous underwater vehicle (BAUV) performed within the confines of the project entitled ‘Autonomous underwater vehicles with silent undulating propulsion for underwater ISR’, financed by Polish National Center of Research and Development. The report includes experiments in the swimming pool as well as in real conditions, that is, both in a lake and in the sea. The tests presented in this part of the final report were focused on low-level control.


2018 ◽  
Vol 213 (2) ◽  
pp. 53-67 ◽  
Author(s):  
Tomasz Praczyk ◽  
Piotr Szymak ◽  
Krzysztof Naus ◽  
Leszek Pietrukaniec ◽  
Stanisław Hożyń

Abstract The paper presents the second part of the final report on all the experiments with biomimetic autonomous underwater vehicle (BAUV) performed within the confines of the project entitled ‘Autonomous underwater vehicles with silent undulating propulsion for underwater ISR’, financed by Polish National Center of Research and Development. The report includes experiments on the swimming pool as well as in real conditions, that is, both in a lake and in the sea. The tests presented in this part of the final report were focused on navigation and autonomous operation.


2021 ◽  
Vol 2129 (1) ◽  
pp. 012080
Author(s):  
Chinonso Okereke ◽  
Nur Haliza Abdul Wahab ◽  
Mohd Murtadha Mohamad ◽  
S H Zaleha

Abstract Water, mostly oceans, covers over two-third of the earth. About 95% of these oceans are yet to be explored which includes 99% of the sea-beds. The introduction of the Internet of Underwater Things (IoUT) underwater has become a powerful technology necessary to the quest to develop a SMART Ocean. Autonomous Underwater Vehicles (AUVs) play a crucial role in this technology because of their mobility and longer energy storage. In order for AUV technologies to be effective, the challenges of AUVs must be adequately solved. This paper provides an overview of the challenges of IoUT, the contributions of AUVs in IoUT as well as the current challenges and opening in AUV. A summary and suggestion for future work was discussed.


2005 ◽  
Vol 39 (3) ◽  
pp. 56-64 ◽  
Author(s):  
Satoshi Tsukioka ◽  
Taro Aoki ◽  
Ikuo Yamamoto ◽  
Hiroshi Yoshida ◽  
Tadahiro Hyakudome ◽  
...  

An ocean-going autonomous underwater vehicle powered by a polymer electrode membrane fuel cell system was completed by The Japan Agency for Marine-Earth Science and Technology. The fuel cell system generates 4kW of electric power for the control electronics and propulsion system. Hydrogen gas is stored under low pressure in the metal hydride. Heat generated by the fuel cell is used to discharge hydrogen gas into the metal hydride. This paper presents the test results of the fuel cell, storage system and the 317km sea test.


2021 ◽  
Vol 29 (1) ◽  
pp. 97-110
Author(s):  
V.S. Bykova ◽  
◽  
A.I. Mashoshin ◽  
I.V. Pashkevich ◽  
◽  
...  

Two safe navigation algorithms for autonomous underwater vehicles are described: algorithm for avoidance of point obstacles including all the moving underwater and surface objects, and limited size bottom objects, and algorithm for bypassing extended obstacles such as bottom elevations, rough lower ice edge, garbage patches. These algorithms are developed for a control system of a heavyweight autonomous underwater vehicle.


Author(s):  
Xi-wen Ma ◽  
Yan-li Chen ◽  
Gui-qiang Bai ◽  
Yong-bai Sha ◽  
Jun Liu

We present a bionic neural wave network that uses multiple autonomous underwater vehicles to search and acquire intelligent targets in an unknown underwater environment. The neuron pheromone content is arranged according to neural wave diffusion and layer-by-layer energy attenuation, when underwater mesh space based on neural wave diffusion theory was established that the neuron nodes in the neural network structure correspond to obstacles, autonomous underwater vehicles, and targets in the environment. In order to solve the problems of over-allocation and under-allocation of the multi-autonomous underwater vehicles system during the cooperative capture of targets, a redistribution mechanism based on the improved self-organizing map algorithm is implemented and directed to rationalize task distribution. Two different taboo search methods are employed to update the autonomous underwater vehicle path in real time, and the polynomial coefficient solution method is used to fit partial path data. So that the autonomous underwater vehicle trajectory can be obtained and an interceptor position coordinate can be predicted. An auxiliary autonomous underwater vehicle is aimed to replace the intercepted autonomous underwater vehicle and the matching capture points are tracked to ensure the completion of the task so that the full range of hunting targets is identified. In order to simulate an unknown complex underwater environment, obstacles are randomly arranged around the target, the location information of the obstacle, and the target is unknown and unpredictable. Four simulation experiments were performed to verify the accuracy and efficiency of the algorithm under unknown environment. The results show that this algorithm can improve the path update average efficiency by 66% compared with other algorithms. Obviously, this algorithm is reasonable and effective.


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