Most autonomous underwater vehicles (AUVs) are propelled by a single thruster, use elevators and rudders as control surfaces, and are torpedo-shaped. Furthermore, they are positively buoyant to facilitate recovery during an emergency. For this class of nonhovering AUVs, there is a minimum speed at which the AUV must travel for stable depth control. Otherwise, the extra buoyancy will bring the A...

This paper describes the experimental implementation of an online algorithm for cooperative localization of submerged autonomous underwater vehicles (AUVs) supported by an autonomous surface craft. Maintaining accurate localization of an AUV is difficult because electronic signals, such as GPS, are highly attenuated by water. The usual solution to the problem is to utilize expensive navigation ...

Twenty years ago, autonomous underwater vehicles (AUVs) were an infant technology, and there was an absence of evolution to guide designers in deciding the fundamental shape and size of their craft. Since this period, researchers have tried a wide variety of AUV shapes and sizes, including torpedo shapes, like the National Oceanography Centre's (NOC) Autosub and Hydroid's (Pocasset, Massachuset...

The present study assesses light-induced variations in phenolic compounds in leaves of saplings of two co-occurring temperate species (Acer platanoides L., and Fraxinus excelsior L.) along a light gradient using a new non-invasive optical method (Dualex). The Dualex-derived UV absorbance of leaf epidermis (the sum of the adaxial and abaxial faces, AUV) increased significantly with increasing li...

We investigate the observability problem of the Simultaneous Localization and Mapping (SLAM) process of an Autonomous Underwater Vehicle (AUV) equipped with inertial sensors, a depth sensor, and an acoustic ranging device that provides relative range measurements to stationary beacons. For trimming trajectories (that is, when the motion of the AUV is in steady-state with constant linear and ang...

The paper addresses the problem of Autonomous Underwater Vehicles which is an under actuated system that traverses autonomously without any external interference and findsextensive applications in defence organizations for underwater mine detection and region surveillance. The system is modelled using INFANTE AUV hydrodynamic parameters that are controlled by path following control using MATLAB...

In this research, a stochastic simulation based design tool that facilitates design in a dynamic environment is developed. The simulation includes a full dynamic model of an Autonomous Underwater Vehicle (AUV) that was developed to evaluate the effectiveness of such a craft given a set of physical attributes. These attributes include but are not limited to: speed, mass, moments of inertia, cont...

In this work a design for self-tuning non-linear Fuzzy Proportional Integral Derivative (FPID) controller is presented to control position and speed of Multiple Input Multiple Output (MIMO) fully-actuated Autonomous Underwater Vehicles (AUV) to follow desired trajectories. Non-linearity that results from the hydrodynamics and the coupled AUV dynamics makes the design of a stable controller a ve...

Most applications of underwater wireless sensor networks (UWSNs) demand reliable data delivery over a longer period in an efficient and timely manner. However, the harsh and unpredictable underwater environment makes routing more challenging as compared to terrestrial WSNs. Most of the existing schemes deploy mobile sensors or a mobile sink (MS) to maximize data gathering. However, the relative...

Memory is thought to be sparsely encoded throughout multiple brain regions forming unique memory trace. Although evidence has established that the amygdala is a key brain site for memory storage and retrieval of auditory conditioned fear memory, it remains elusive whether the auditory brain regions may be involved in fear memory storage or retrieval. To investigate this possibility, we systemat...