The movement parameters of yellow fin tuna schools were analyzed by means of scanning sonar in tuna purse seine capture situations in the Oman Sea in June 2010. There was significant difference in swimming speed and radial swimming direction between the escaped and captured schools. In escaped cases, the fish schools swam faster with mostly horizontal avoidance behavior to the sound stimuli fro...

In this paper, different techniques/methodologies/strategies that are used in the field of mobile robot navigation have been reviewed forunknown environment is an important task for the new generation of several mobile robots. We consider the wheeled mobile robotsfor Path Planning, an autonomous robot and an obstacle and collision avoidance to be used in sensor based robots. We propose that dri...

Underwater environments are extremely challenging to perform localization. Autonomous Underwater Vehicles (AUV) are usually endowed with acoustic devices such as a Mechanically Scanned Imaging Sonar (MSIS). This sensor scans the environment by emitting ultrasonic pulses and it provides echo intensity profiles of the scanned area. Our goal is to provide self-localization capabilities to an AUV e...

In this paper, we focus on the construction of a full 3D model of a canal tunnel by combining terrestrial laser (for its above-water part) and sonar (for its underwater part) scans collected from static acquisitions. The modeling of such a structure is challenging because the sonar device is used in a narrow environment that induces many artifacts. Moreover, the location and the orientation of ...

This paper presents a novel approach to localize an underwater mobile robot based on scan matching using a Mechanically Scanned Imaging Sonar (MSIS). When used to perform scan matching, this sensor presents some problems such as significant uncertainty in the measurements or large scan times, which lead to a motion induced distortion. This paper presents the uspIC, which deals with these proble...

This study proposes an alternative effective sonar image enhancement algorithm. The method basically composes of two steps, including noise reduction and image sharpening. The sonar image is first de-noised using Wiener and median filters, and then it is enhanced using unsharp masking and histogram equalization. The proposed algorithm has been verified on many sonar images of different underwat...

We present a complete characterization of shortest paths to a goal position for a vehicle with unicycle kinematics and a limited range sensor, constantly keeping a given landmark in sight. Previous work on this subject studied the optimal paths in case of a frontal, symmetrically limited Field–Of–View (FOV). In this paper we provide a generalization to the case of arbitrary FOVs, including the ...

This paper describes a new highly accurate fast selfcontained sonar sensor. Transmission and echo analysis are performed at repetition rates exceeding 27 Hz for ranges to 5.4 metres. The sensor contains low noise variable gain preamplifiers, two 1 MHz 12 bit ADC receivers and a DSP echo processor. Optimal arrival time estimation is performed by the DSP using matched filtering of echoes with sho...

We present a feature-based probabilistic map building algorithm which directly utilizes time and amplitude information of sonar in indoor environments. Utilizing additional amplitude-of-signal (AOS) obtained concurrently with time-of-flight (TOF), the amount of inclination of target can be directly calculated from a single echo, and the number of measurements can be greatly reduced with result ...

Glider class autonomous underwater vehicles operate and collect water column data for long periods of time, even weeks, before the need for recovery. However, they possess only rudimentary navigation and localization capabilities. Gliders are under-actuated vehicles and prone to water currents disturbances hence their localization error increase significantly while dead-reckoning underwater. In...