The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Seawater chlorophyll-a (Chla) represents algal biomass in ocean and is a major index of eutrophication. In this paper, bootstrapped artificial neural network (BANN) model is developed for predicting the seawater Chla concentration around the north Pacific Rim. Three-layer ANN structure is applied and the modeling is based on comprehensive five-minute interval datasets of water temperature, depth,...
Precise and efficient numerical simulation of tracer transport processes in the marine environment is critical for environmental problems. Particle tracking method has the advantages over Eulerian method by overcome the problem of numerical diffusion but the concentration from typical particle tracking methods is affected by the number of particles used and the size of the volume cell. DREAM model...
Hybrid underwater glider (HUG) combines behaviors of autonomous underwater gliders and those of traditional autonomous underwater vehicles. HUG can dive along a saw-tooth trajectory in the gliding mode and autonomously cruise in the level-flight mode. In the study of HUG dynamics, the mathematical model and the physical parameters of the vehicle are assumed to be deterministic. The simulation results...
Matched-field processing (MFP) is an underwater acoustic signal processing method for passive source localization. It works by matching the measured field with the full-field solution for sound wave propagation in an oceanic waveguide. The popular Minimum Variance Distortionless Response (MV-DR) algorithm is known to be highly sensitive to environmental mismatch, which is one of the main obstacles...
In this paper, we propose an Error Tolerant Dual-Hydrophone Localization method, i.e., ET-DHL, in underwater sensor networks (USNs). To reduce the impact of the node uncertainty, measurement uncertainty, poor link quality and long latency for underwater localization problem, ET-DHL adds bit-level probability to process the binary sequence. Different from our previous work PCM, each dual-hydrophone...
Formation control of autonomous underwater vehicle (AUV) team based on adaptive high order sliding mode is studied in the paper. First, the kinematics control law is given based on the guidance function. Then, as sliding mode controller (SMC) is widely used in motion control of underwater vehicles, a robust and continuous controller using high order sliding mode method is proposed to achieve leader-follower...
In shallow water, loud surface ships can mask the weak signal of the underwater target. In this case, the localization of the target is difficult due to side-lobes of the interferers. By incorporating the prior knowledge of the uncertain parameters, we have proposed a robust localization method [Liu, et al. Robust source localization using predictable mode subspace in uncertain shallow ocean environment...
This paper focuses on coverage sampling over a given region by a fleet of underwater gliders. The coverage performance is evaluated by the observing uncertainty performed by Objective Analysis (OA). Deployed gliders are commonly restricted to move through transects along which the data collected are convenient for data assimilation. We optimize the initial location and the initial heading of each...
For UUV fault detection, we propose a multi-sensor information fusion diagnosis method based on D-S evidence theory. We use the feature information which is extracted by fuzzy membership function to construct the basic probability functions. Then use the weighted distribution method for basic probability functions to avoid the evidence conflict. Finally we use the combining method which was proposed...
For the terminal phase of AUV impact the non-stationary targets, the terminal guidance problem is studied. Based on backstepping sliding mode control method and linear extended state observer, a nonlinear guidance law with impact angle constraints is proposed. Regarding the target acceleration and external disturbance as unknown disturbance, and using the linear extended state observer to estimate...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.