수중 원통형 쉘 구조물의 고주파 진동 전달특성에 대한 실험적 연구

In this chapter, the receding horizon Kalman filter is applied to underwater navigation systems. The ocean covers about two-thirds of the earth and has a great effect on human beings. However, the ocean is overlooked while we focus our attention on land and atmospheric issues; we have not been able to explore the full depths of the ocean, its abundant livings and non-living resources. For example, only recently we have discovered, by using manned submersibles, that a large amount of methane and carbon dioxide comes from the seafloor and extraordinary groups of organisms live in hydrothermal vent areas. However, a number of complex issues due to the unstructured and hazardous undersea environment make it difficult to survey in the ocean even though today’s technologies have allowed humans to land on the moon and robots to travel to Mars. Unmanned underwater vehicles (UUVs) can help us better understand marine and other environmental issues, protect the ocean resources of the earth from pollution, and efficiently utilize them for human welfare. The UUV is a platform for a variety of sensors: acoustic, magnetic, gravimetric and chemical ones. Most commercial UUVs are tethered and remotely operated, referred to as remotely operated vehicles (ROVs). Extensive use of manned submersibles and ROVs are currently limited to a few applications because of very high operational costs, operator fatigue and safety issues. The demand for advanced underwater vehicle technologies is growing and will eventually lead to fully autonomous and reliable underwater vehicles. Autonomous underwater vehicles (AUVs) were initially developed to perform missions that were not easy for ROVs and manned underwater vehicles. Since the autonomy allows AUVs to be used for risky missions such as a mine countermeasure (MCM) or under-ice operations, AUVs are replacing ROVs towed vehicles as well as manned underwater vehicles (Whitcomb, 2000). For detailed ocean surveys, an AUV acts as a more stable platform for precision sensors than ROVs or towed vehicles because an AUV is not subject to physical disturbances transmitted along the cable to the surface vessel. This absence of physical attachment also allows AUVs to measure ocean characteristics at specific depths and perform bottom-following missions as owing to its autonomy. In short, An AUV provides marine researchers with a new form of access to deeper ocean. For an AUV to successfully complete a typical survey mission, it must follow a path specified by the operator as closely as possible and arrive at a precise location for collecting data. When an AUV is not able to follow the path accurately during the mission, critical Source: Kalman Filter, Book edited by: Vedran Kordic, ISBN 978-953-307-094-0, pp. 390, May 2010, INTECH, Croatia, downloaded from SCIYO.COM

As the continuity of Unmanned Underwater Vehicle (UUV) research, we have been developing the small size of underwater vehicle [1]. Commercially this vehicle was known with Remotely operated vehicle (ROV). This vehicle have dimension (LxWxH) 490mmx410mmx320mm with weight on air around 7 kg. Total buoyancy of this vehicle construction around 8 kg. So we still have spare 1 kg buoyancy for payload. The maximum operating depth of this vehicle designed at maximum 30 meters of Salt water. Main construction of this vehicle is from Composite that’s have strength enough to hold all external load and forces. This mini ROV categorized as small observation ROV that’s just have camera and underwater lamp to observe underwater site and also as main navigation tools for pilot to operate this vehicle. In order to propelled this vehicle, we have attached three brushless DC Electric underwater thruster with capacity 200 Watt. This vehicle controlled by pilot on surface station via umbilical cable. The communication between vehicle and surface station used RS-485 standard communication. Remotely operated underwater vehicles are progressively more used for routine inspection and maintenance tasks. The most application that we have designed before was for ship hull inspection. Marine growth and cathodic protection anode inspection is the main task for this ROV on ship hull Maintenance. But with the additional payload like small manipulator can increased the task that’s it can handle, likes collecting sample and cutting rope. Step by step design process until preliminary testing maneuver on pool will be described in this paper.

The advantages of using unmanned underwater vehicles in coastal ocean studies are emphasized. Two types of representative vehicles, remotely operated vehicle (ROV) and autonomous underwater vehicle (AUV) from University of South Florida, are discussed. Two individual modular sensor packages designed and tested for these platforms and field measurement results are also presented. The bottom classification and albedo package, BCAP, provides fast and accurate estimates of bottom albedos, along with other parameters such as in-water remotes sensing reflectance. The real-time ocean bottom optical topographer, ROBOT, reveals high-resolution 3-dimentional bottom topography for target identification. Field data and results from recent Coastal Benthic Optical Properties field campaign, 1999 and 2000, are presented. Advantages and limitations of these vehicles and applications of modular sensor packages are compared and discussed.

Design of new unmanned underwater vehicles (UUVs) is a continuous process since decades, where finding an optimal design for a specific application is still a challenging subject. New inspection class category remotely operated vehicle (ROV) is developed to overcome some disadvantages of existing ROVs of the same category. It has been taken into consideration in the new design to be small, capable of maneuvering freely in 6 DOF, closed-hull body of minimum water resistive forces, low-cost components which work with high integration, one-duct tether (at low cost) and software program to be used with any PC instead of special control station. Detailed design of the internal network that combines sensors, thrusters’ controllers, and camera of the ROV is shown and smart communication architecture between the ROV and the control station is also introduced. Finally, in the computer layer, many aspects are discussed including communication protocol between the control station and the ROV, high-precision orientation angles calculation using inertial measurement unit (IMU), heading calculation of the ROV, and GUI of the control station.

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.

The Amazon basin is one of the largest hydrographic systems in the world, possessing a great diversity of natural resources in need of more sustainable water and environmental management. However, as much of what lies beneath the surface of Amazonian waters is still unexplored, underwater exploration technologies are seen as a means of research and monitoring. The present work therefore aims to answer two research questions: What are the current technologies that could be implemented for unmanned underwater research in the Amazon waters? What are the main limitations and existing alternatives for using unmanned underwater vehicles in the rivers of this region to provide more sustainable water and environment management? Our results demonstrate that remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs) are possible options in the short and long terms, respectively. The main challenges in implementing these technologies are related to the variations in hydraulic geometry, current velocities and turbidity of the rivers, as well as the preservation of the region's biodiversity. This research can be taken as a starting point for planners and decision makers seeking more sustainable underwater and environmental exploration of the Amazon river system.

Autonomous underwater vehicles (AUVs), unmanned underwater vehicles, are cheaper to operate than remotely operated vehicles (ROVs), since an AUV does not require a trained human operator to control. As a result, in this paper, we propose the pipeline tracking algorithm using sequences of the forward-looking sonar (FLS) images installed on a preprogram AUV. The FLS is more suitable to be used in the subsurface environment than an optical camera due to the limited visibility and floating particles in the sub-sea surface environment. In our work we first employed the speckle noise reduction to the FLS images. Then, we applied the level-set method (LSM) to extract a pipeline boundary in each frame. Lastly, the post-processing step was designed to link the unconnected segments together to from a complete pipeline. Our algorithm can perform the segmentation and tracking with more than 85% accuracy.

Unmanned, underwater vehicles have been developed considerably in recent years. Remotely operated vehicles (ROVs) are increasingly used for routine inspection and maintenance tasks but have a range that is limited by the umbilical cable. For long range operations, such as oceanographic exploration and surveying, autonomous underwater vehicles (AUVs) are emerging which haveon-board power and are equipped with advanced control capabilities to carry out tasks with the minimum of human intervention. AUVs typically resemble torpedoes in that mosthave control surfaces and a single propulsion unit, and must move forwards to manoeuvre. Such vehicles are called flight vehicles. This paper describes techniques which are candidates for control of a flight AUV and identifies controllers used on some existing vehicles. Since underwater vehicle dynamics are nonlinear, fuzzy logic and sliding mode control were felt to have promise for autopilot application due to their potential robustness. Following development using a comprehensive simulation programme, the controllers were tested using the experimental vehicle, Subzero II, and their performance compared with that of a classical linear controller. The relative merits of the methods for practical implementation are discussed.

Remotely Operated Vehicle (ROV) merupakan sebuah wahana atau robot bawah air yang dirancang untuk mampu bergerak di dalam air. Permintaan ROV diprediksi akan semakin meningkat dimasa yang akan datang, karenanya perlu direspons dengan penyediaan suatu ROV yang mudah untuk dibangun dan dioperasikan. Penelitian ini bertujuan untuk mendesain dan membangun suatu ROV yang mudah untuk diikuti proses pembuatannya dan mudah untuk dioperasikan sehingga ke depannya dapat dimanfaatkan untuk keperluan observasi. Remotely Operated Vehicle dirancang dengan dimensi panjang 311,89 mm, lebar 240 mm dan tinggi 180 mm. Remotely Operated Vehicle memiliki tiga motor penggerak dengan Pulse Width Modulation (PWM) Speed Cotroller Module sebagai sistem kendali. Pengujian ROV dilakukan meliputi uji pergerakan dan uji manuver, dengan hasil menunjukkan bahwa ROV memiliki rata-rata kecepatan maju 0,26 m/s dengan waktu berputar 180° menuju portside selama 6,7 s dan berputar 180° menuju starboard selama 6,3 s, serta gerakan melingkar selama 8,2 s. Uji pergerakan dan manuver ROV menunjukkan hasil yang baik, sehingga rencana pengembangan lebih lanjut dari ROV ini dapat terus dilakukan.

Review of EMC standards for Underwater Vehicles

This paper demonstrates the design and development of a novel system which comprises of a command boat and Unmanned Underwater Vehicle (UUV) with which, one is able to extend the range of operation of the Remotely Operated underwater Vehicle (ROV) which is limited by the length of tether. The UUV proposed in our system can be utilized along with features and functionality of existing designs, along with an added advantage of incorporating additional accessories depending upon the application. The system comprises of three components: a control unit, command boat and an UUV. The control unit is situated in any physical planar surface. The operator controls the command boat–UUV system wirelessly, which are linked using a tether. The UUV can assist in exploration, research, search and recovery etc. In the case of search and recovery, the command boat is guided to the required location, then the system identifies the retrievable using camera and appropriate sensors, then the UUV is deployed which is further guided towards the retrievable, and a pair of robotic arms with tangible gripper recovers the retrievable (weighing atmost 2kg). The UUV and the retrievable is docked to the command boat and the system is acquired, hence completing the operation.

Morphing hull concept for underwater vehicles

This paper presents a method for wide bandwidth stiff position control of unmanned underwater and space vehicles. We start by arguing that the use of feedback alone may not provide an underwater or a space vehicle sufficient bandwidth with large stiffness. In other words with feedback alone the vehicle may not behave like a stiff platform in the presence of a wide frequency range of disturbances. Given this limitation, we suggest that the vehicle must be connected to environmental structures by means of cables or grabbers. These connecting cables will develop dynamic and kinematic constraints on the vehicle motion. This problem led us to develop a method that allows for control of the motion of constrained underwater or space vehicles. This method is called Impedance Control [1],[2],[3]. The frequency domain essentials of Impedance Control and a robust controller design method are given in reference [3]. We explain how, with the help of this method, a vehicle connected to a structure by means of cables can be positioned with high stiffness while at the same time the cable tensions are also under control.

Abstract. Unmanned underwater vehicle (UUV) is a key technology for marine resource exploration and ecological monitoring. How to use vision-based active positioning and three-dimensional perception to realize UUV underwater autonomous navigation and positioning is the basis for UUV's underwater operations. The complexity and unstructured characteristics of seawater bring new challenges to vision-based underwater high-precision positioning. Traditional visual localization algorithms mainly include geometric-based visual localization algorithms (such as ORB-SLAM2) and deep learning-based visual localization algorithms (such as DXSLAM). In this paper, based on the typical marine environment (low brightness, dynamic fish interference, underwater light spot, high turbidity), the experimental analysis and comparison of different visual positioning methods of UUV is carried out, which provides a reference for realizing the real-time localization of UUV, and further provides a better solution for UUV underwater measurement and monitoring operations.

This paper describes the effectiveness of observer-based output feedback for Unmanned Underwater Vehicle (UUV) with Linear Quadratic Regulation (LQR) performance. Tuning of observer parameters is crucial for tracking purpose. Prior to tuning facility, the ranges of observer and LQR parameters are obtained via system output cum error. The validation of this technique using unmanned underwater vehicles called Remotely Operated Vehicle (ROV) modelling helps to improve steady state performance of system response. The ROV modeling is focused for depth control using ROV 1 developed by the Underwater Technology Research Group (UTeRG). The results are showing that this technique improves steady state performances in term of overshoot and settling time of the system response.