Use Of Unmanned Underwater Vehicles Research Articles

Research on Multi-Target Path Planning for UUV Based on Estimated Path Cost

The precision and efficiency of multi-target path planning are crucial factors influencing the performance of anti-mine operations using unmanned underwater vehicles (UUVs). Addressing the inadequacies in computation time and solution quality present in existing path planning algorithms, this study proposes a novel path cost estimation strategy based on neural networks. This strategy swiftly generates an accurate cost matrix, ensuring the attainment of high-quality traversal orders when utilized as input for the traveling salesman problem, thereby yielding a globally optimal path. Simulation experiments demonstrate that while maintaining high-quality solutions, the proposed strategy significantly enhances the computational efficiency of the algorithm. Furthermore, the practical application and effectiveness of the proposed algorithm have been demonstrated through an actual UUV prototype experiment in a lake environment.

THE IMPLEMENTATION OF SOVEREIGN IMMUNITY OF WARSHIPS TO UNMANNED UNDERWATER VEHICLES (UUV) UNDER LAW OF THE SEA

Along with the times, there have been advances in marine technology which includes Unmanned Underwater Vehicles (UUV). Some countries have started using UUVs for both commercial and military marine activities since UUVs have several advantages that ordinary ships do not have. However, the development and application of UUVs for marine purposes raises numerous problems since there isn’t clear regulation regarding UUV. Current legal instruments only explain the meaning of ship without classifying the type of ship itself. It raises a problem since it led to different interpretations between countries and the determination of legal rules for UUV. One incident related to UUV technology can be seen from the Bowditch incident where from this incident there are differences in interpretation on the classification of UUV between America and Tiongkok. Other incidents can also be seen from the entry of foreign UUVs into Indonesia waters for research purposes. From several incidents, there are main issues to the classification of UUVs which are connected to warships and their military activities. The classification of UUVs as merchant ships or warships is necessary considering that the rights of immunity owned by warships will affect the legal status of UUVs and their activities. Regulations that are still ambiguous will affect the Coastal State’s actions if there are foreign UUVs entering their sea areas, especially if the UUVs are used for military activities. Therefore, it is necessary to have clear regulations regarding UUVs including their classification and determine marine activities that allowed for the use of UUVs.

Analytical Approach to Sampling Estimation of Underwater Tunnels Using Mechanical Profiling Sonars.

Hydroelectric power plants often make use of tunnels to redirect the flow of water to the plant power house. Such tunnels are often flooded and can span considerable distances. Periodical inspections of such tunnels are highly desirable since a tunnel collapse will be catastrophic, disrupting the power plant operation. In many cases, the use of Unmanned Underwater Vehicles (UUVs) equipped with mechanical profiling sonars is a suitable and affordable way to gather data to generate 3D mapping of flooded tunnels. In this paper, we study the resolution of 3D tunnel maps generated by one or more mechanical profiling sonars working in tandem, considering synchronization and occlusion problems. The article derives the analytical equations to estimate the sampling of the underwater tunnels using mechanical profiling sonars (scanning sonars). Experiments in a simulated environment using up to four sensors simultaneously are presented. We also report experimental results obtained by a UUV inside a large power plant tunnel, together with a first map of this environment using a single sonar sensor.

2D Optimal Trajectory Planning Problem in Threat Environment for UUV with Non-Uniform Radiation Pattern.

Path planning is necessary in many applications using unmanned underwater vehicles (UUVs). The main class of tasks is the planning of safe routes with minimal energy costs and/or minimal levels of emitted physical and information signals. Since the action planner is on board the UUV, the main focus is on methods and algorithms that allow it to build reference trajectories while minimizing the number of calculations. The study is devoted to the problem of the optimal route planning for a UUV with a non-uniform radiation pattern. The problem is stated in the form of two point variational problem for which necessary and sufficient optimality conditions are proved. Particular attention is paid to cases where optimality conditions are not met. These cases are directly related to found specific forms of a radiation pattern. Sufficient optimality conditions are extended on the class of two-link and multi-link motion paths. Software tools have been developed and computer simulations have been performed for various types of radiation patterns.

Path Following, Obstacle Detection and Obstacle Avoidance for Thrusted Underwater Snake Robots

The use of unmanned underwater vehicles is steadily increasing for a variety of applications such as mapping, monitoring, inspection and intervention within several research fields and industries, e.g., oceanography, marine biology, military, and oil and gas. Particularly interesting types of unmanned underwater vehicles are bio-inspired robots such as underwater snake robots (USRs). Due to their flexible and slender body, these versatile robots are highly maneuverable and have better access capabilities than more conventional remotely operated vehicles (ROVs). Moreover, the long and slender body allows for energy-efficient transit over long distances similar to torpedo-shaped autonomous underwater vehicles (AUVs). In addition, USRs are capable of performing light intervention tasks, thereby providing intervention capabilities which exceed those of AUVs and inspection class ROVs. USRs may also propel themselves using energy-efficient motion patterns inspired by their biological counterparts. They can thereby increase the propulsion efficiency during transit and maneuvering, which is among the great challenges for autonomous underwater vehicles. In this paper, a control system for path following, and algorithms for obstacle detection and avoidance, are presented for a USR with thrusters attached at the tail module. The position of the obstacles is detected using a single camera in the head module of the USR and a developed computer vision algorithm. For the proposed control concept the robot joints are used for directional control while the thrusters are used for forward propulsion. The USR circumvents obstacles by following a circular path around them before converging back to the main straight line path when this is safe. Experimental results that validate the proposed methods are also presented.

On a method for supporting visual identification of underwater objects

Abstract The search and detection of objects under water is carried out by groups of specialised divers. However, their time underwater and their ability to penetrate the depths are limited. For these reasons, the use of unmanned underwater vehicles equipped with technical observation equipment, including TV cameras, is becoming increasingly popular for these tasks. Video images from cameras installed on vehicles are used to identify and classify underwater objects. The process of recognition and identification of objects is tedious and difficult and requires the analysis of numerous sequences of images, and so it is desirable to automate this process. In response to these needs, this article presents the concept of identification of underwater objects based on visual images from an underwater body of water sent from an unmanned underwater vehicle to a base vessel. The methods of initial processing of the observed images from an underwater area as well as the method of searching for selected objects in these images and their identification with the use of the Hough transform will be described. Furthermore, the paper presents the results of the preliminary processing and identification of the observed images following a deconvolution operation.

UUV's in Maritime Spill Response Exercise Cathach

Exercise Cathach was a large training exercise which utilised and evaluated the use of Unmanned Underwater Vehicles (UUV's) and sensors in a maritime spill Incident involving oil and harmful and noxious substances (HNS). The exercise was a first in terms of the level of robotic systems deployed to assist in survey, surveillance and inspection roles, assessing the scene in real-time before committing first responders for respond and recover operations. The evaluation showed the effectiveness of these technologies to operate in harsh conditions and the efficiency and usability of the real-time data from operations in the field.

A simplified concept for recovering a UUV to a submarine

The use of unmanned underwater vehicles (UUVs) to enhance the military capabilities of submarines and to reduce their operational risk is being considered by navies around the world. However, a major difficulty with the operations of UUVs is their recovery back to the submarine at the end of the mission. Various schemes have been proposed by a number of organisations working in this field; however, they all have major drawbacks. A simple concept is proposed based on a warp from the submarine to a low aspect ratio wing, similar to an otter board used by fishing trawlers. This approach allows the submarine to recover the UUV by slowly overtaking it. This is done at a sufficiently large transverse distance between the vessels where hydrodynamic interaction between the two is minimal, with the submarine travelling at a speed at which it can be safely controlled.

Underwater optical wireless communication network

The growing need for underwater observation and subsea monitoring systems has stimulated considerable interest in advancing the enabling technologies of underwater wireless communication and underwater sensor networks. This communication technology is expected to play an important role in investigating climate change, in monitoring biological, biogeochemical, evolutionary, and ecological changes in the sea, ocean, and lake environments, and in helping to control and maintain oil production facilities and harbors using unmanned underwater vehicles (UUVs), submarines, ships, buoys, and divers. However, the present technology of underwater acoustic communication cannot provide the high data rate required to investigate and monitor these environments and facilities. Optical wireless communication has been proposed as the best alternative to meet this challenge. Models are presented for three kinds of optical wireless communication links: (a) a line-of-sight link, (b) a modulating retroreflector link, and (c) a reflective link, all of which can provide the required data rate. We analyze the link performance based on these models. From the analysis, it is clear that as the water absorption increases, the communication performance decreases dramatically for the three link types. However, by using the scattered light it was possible to mitigate this decrease in some cases. It is concluded from the analysis that a high-data-rate underwater optical wireless network is a feasible solution for emerging applications such as UUV-to-UUV links and networks of sensors, and extended ranges in these applications could be achieved by applying a multi-hop concept.

Graphical Mission Specification and Partitioning for Unmanned Underwater Vehicles

The use of Unmanned Underwater Vehicles (UUVs) has been proposed for several different types of applications including hydrographic surveys (e.g., mapping the ocean floor and exploring sunken wreckage), mine detection and identification, law enforcement (e.g., enforcing certain fishing regulations), environmental and pollution monitoring, and even performing surveys to find potential drilling locations on the ocean floor for the oil industry. Recently the idea of using multiple, cooperating UUVs to execute these missions has also been proposed. There are two main factors that dictate a particular mission’s success. The first factor regards creating a mission that is free from errors, in terms of both syntax and semantics. The second factor deals with properly splitting a mission into a set of sub-missions and assigning each sub-mission to a group of UUVs. Even though tools have been developed to help reduce these potential problems such as high level mission programming languages, compilers for these languages and utilities to automatically split an operator specified mission, the potential still exists for errors when creating a mission (e.g. semantic errors introduced from programming and maintaining the code for existing missions). The goal of this article is to present a programming-free, parallel mission generation utility that uses a series of tools we developed along with a commercially available graphical package. Our utility allows an operator to graphically specify a mission for a group of UUVs and automatically split the mission among the group based on an objective provided by the operator. The main contribution of this tool is twofold. First, it relieves the operator from low-level mission programming including the manual partitioning of the mission across a group of available UUVs. Second, it allows the operator to review the resulting set of generated sub-missions using the graphical interface. Thus, no matter what the particular UUV application is, this tool is another step towards successfully creating missions for UUVs.