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Receiver needn't get to current navigation data and only need to synchronize satellites' signal. So it need achieve the satellite navigation data from special server. The reference moment have bias when receiver captures satellites' signal. It was found though analysis there is a connection between positioning bias and reference moment bias. There is a very large positioning bias when the reference...
Generally, underwater hull inspection have been conducted by human divers. It is an extremely dangerous task, and hence, can be a potential application for unmanned underwater vehicles. The operational safety and performance of in-water inspection can be significantly improved by introducing unmanned vehicle systems. This study addresses the development of an hover-capable autonomous underwater vehicle...
An automated docking system is presented for an autonomous underwater vehicle utilizing light-field imaging for navigation guidance. This article focuses on three major components of the system: docking position acquisition with light-field imaging, optimal docking trajectory planning, and nonlinear trajectory tracking control. With the camera sensor data of each photographic exposure, depth maps...
Development of an autonomous unmanned surface vehicle (USV) that may serve as a mother ship for a small unmanned aerial vehicle (UAV) and a small autonomous underwater vehicle (AUV), in support of surface autonomy in sensing and surveillance missions, is described. The USV development includes implementation of low-level controls, stereovision perception, and a task-oriented high-level planner, which...
In autonomous mapping surveys the autonomous underwater vehicle (AUV) cannot rely on receiving position aiding from a surface vehicle or any other external infrastructure. The AUV can however use any payload sensor to restrict the position error drift in the navigation system. In this paper we consider how to use the terrain in a pre-surveyed baseline to bound the drift in the estimated AUV position...
This paper proposes and implements a convolutional neural network (CNN) that maps images from a camera to an error signal to guide and control an autonomous underwater vehicle into the entrance of a docking station. The paper proposes to use an external positioning system synchronized with the vehicle to obtain a dataset of images matched with the position and orientation of the vehicle. By using...
This paper reports what to our best knowledge is the first commercially delivered under-ice survey carried out by an autonomous underwater vehicle (AUV). The campaign was completed as a collaboration between Kongsberg Maritime (KM) and Ballard Marine Construction in January 2017. The surveys took place beneath a frozen lake in North America using a rental KM MUNIN AUV, with launch and recovery through...
The tide in the eastern Yellow Sea is well-known for its large tidal range and thus, the seasonal variation of tide is an important concern for sea level rise and coastal disaster prevention. In order to understand the seasonal variation of tides in the west and south coasts of Korea, a yearlong sea level data at sixteen stations are analyzed. Results show that the M2 tide in the south coast have...
Augmented reality (AR) is an emerging technology that superimposes digital information directly on top of a user's real world view. AR may have great potential for aiding safe marine navigation, however the devices currently available have significant limitations that prevent them from being practical for marine usage. While suitable devices are still a few years away from the market, we propose that...
It is known that there are seafloor mineral deposits around Japan islands. Gravity survey is one of powerful methods to obtain density structure in crust, especially for exploration of underground deposits. We have developed an underwater gravity measurement system for exploration below a seafloor using an Autonomous Underwater Vehicle. In 2014 and 2015, mapping of seafloor gravity anomalies by the...
A set of Matlab tools were developed to create seafloor mosaics from AUV photosurveys. The resulting mosaic products are used to guide instrument placement, ground-truth acoustic backscatter targets, and inspect sensor packages or other targets. Because of the positional sensitivity of these tasks, effort has been made to preserve the geographic distribution of the image content. After initial image...
Autonomous underwater vehicles (AUVs) used to locate multiple acoustic-tagged fish have previously been unable to alter their pre-programmed search paths to obtain precise position estimates. This problem is solved by the development of payload control software (Synthetic Aperture Override, SAOVR) that initiates maneuvers with trajectories favorable for estimating the tag's location from a synthetic...
A tunable high-Q resonator sound source with exceptional demonstrated performance has been developed by Teledyne Marine. The sound source is efficient, powerful, and has unlimited operational depth, as well as a minimum level of high frequency harmonic content. The projector transmits a digitally synthesized frequency swept signal and the mechanical actuator tunes a high-Q organ pipe to match the...
Autonomous Surface Vehicles (ASVs) rely on two layers of guidance for effective path planning: global and local methods. Global methods require a macroscopic view of the mission's goals in order to efficiently navigate an environment. For this research, different global path planner algorithms are explored both in simulation and in field tests to observe path planner qualities for modularity, practicality,...
This paper presents an autonomous approach of 3-D reconstruction of underwater terrain using multi-level coverage trees. An autonomous underwater vehicle (AUV) equipped with multi-beam sonar sensors, Doppler velocity log (DVL) and inertial measurement unit (IMU) sensors is used to achieve this goal. The underwater 3-D search space is represented by a multi-level coverage tree which is generated online...
It is usual for a consumer to search a product based on its category and go to related kind of shop to buy a product, e.g. food in supermarket, a pencil from a stationary shop and etc. While it is not uncommon nowadays for a shop to sell various categories of goods at the same time, like a newspaper stand do sell toys, an accessory shop has stationary. However, consumer may not easily notice and purchase...
There has been a lot of work on finding safest path from source to destination. However, all these works mainly rely on the crime data available through government sources. The works are missing many important factor that affect safety of a route. In this work, we first propose safety measurement score and then show how it can be used for safe navigation. We proposed a comprehensive safety measure...
The rapidly increasing volume of videos recorded in the course of endoscopic screenings and surgeries poses demanding challenges to video retrieval and browsing systems. Surgeons typically have to use standard video players to retrospectively review their procedures, which is an extremely cumbersome and time-consuming process. We present an HTML5-based video explorer that is specially tailored to...
The article describes the hardware architecture of computational units for the construction of GLONASS / GPS navigation user equipment. The described possible route to improve of some architectures based on field programmable gate arrays (FPGAs).
With the rapid development of mobile apps, the availability of a large number of mobile apps in application stores brings challenges to locate appropriate apps for users. Providing accurate mobile app recommendation for users becomes an imperative task. Conventional approaches mainly focus on learning users' preferences and app features to predict the user-app ratings. However, most of them did not...
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