Fabio M. Marchese

Omni-directional catadioptric vision for soccer robots

Abstract This paper describes the design of a multi-part mirror catadioptric vision system and its use for self-localization and detection of relevant objects in soccer robots. The mirror and associated algorithms have been used in robots participating in the middle-size league of RoboCup — The World Cup of Soccer Robots.

Mapping Cold-Water Coral Habitats at Different Scales within the Northern Ionian Sea (Central Mediterranean): An Assessment of Coral Coverage and Associated Vulnerability

In this study, we mapped the distribution of Cold-Water Coral (CWC) habitats on the northern Ionian Margin (Mediterranean Sea), with an emphasis on assessing coral coverage at various spatial scales over an area of 2,000 km2 between 120 and 1,400 m of water depth. Our work made use of a set of data obtained from ship-based research surveys. Multi-scale seafloor mapping data, video inspections, and previous results from sediment samples were integrated and analyzed using Geographic Information System (GIS)-based tools. Results obtained from the application of spatial and textural analytical techniques to acoustic meso-scale maps (i.e. a Digital Terrain Model (DTM) of the seafloor at a 40 m grid cell size and associated terrain parameters) and large-scale maps (i.e. Side-Scan Sonar (SSS) mosaics of 1 m in resolution ground-truthed using underwater video observations) were integrated and revealed that, at the meso-scale level, the main morphological pattern (i.e. the aggregation of mound-like features) associated with CWC habitat occurrences was widespread over a total area of 600 km2. Single coral mounds were isolated from the DTM and represented the geomorphic proxies used to model coral distributions within the investigated area. Coral mounds spanned a total area of 68 km2 where different coral facies (characterized using video analyses and mapped on SSS mosaics) represent the dominant macro-habitat. We also mapped and classified anthropogenic threats that were identifiable within the examined videos, and, here, discuss their relationship to the mapped distribution of coral habitats and mounds. The combined results (from multi-scale habitat mapping and observations of the distribution of anthropogenic threats) provide the first quantitative assessment of CWC coverage for a Mediterranean province and document the relevant role of seafloor geomorphology in influencing habitat vulnerability to different types of human pressures.

Omni-Directional Vision with a Multi-part Mirror

This paper presents an omni-directional sensor based on a camera and a mirror generated with a surface of revolution. The requirements the device must fulfill result from its use as the main perception system for the autonomous mobile robots used in F2000 RoboCup competitions. The more relevant requirements which have been pursued are: 1) range sensing in a quite wide region centered around the robot, with good accuracy; 2) sensing around the robot in a given vertical sector, in order to recognize team-mates and adversaries (all robots have a colored marker above a given height); 3) range sensing in a region very close around the robot, with the highest accuracy, to locate and kick the ball. Such requirements have been fulfilled by the design of a mirror built up of three different parts. Each part is devoted to the fulfillment of one requirement. Concerning the first requirement the approach developed is based on the design of a mirrors profile capable to optically compensate the image distortion provided by the mirror profiles commonly used in previous literature. This approach resulted to be similar to a previous work by Hicks and Bajcsy, although independently developed by the authors.

A directional diffusion algorithm on cellular automata for robot path-planning

Cellular automata (CA) model is a powerful instrument used in many applications. In this paper we present a reactive path-planning algorithm for a non-holonomic mobile robot on multilayered cellular automata. The robot considered has a preferential motion direction and has to move using smoothed trajectories, without stopping and turning in place, and with a minimum steering radius. We have implemented a new algorithm based on a directional (anisotropic) propagation of repulsive and attracting potential values in a multilayered cellular automata model. The algorithm finds all the optimal collision-free trajectories following the minimum valley of a potential hypersurface embedded in a 4D space, built respecting the imposed constraints. Our approach turns out to be distributed and incremental: whenever changing the initial or the final pose, or the obstacles distribution, the automata start evolving towards a new global steady state, looking for a new set of solutions. Because it reacts to obstacles distribution changes, it can be also used in unknown or dynamical environments in combination with a world modeler. The path-planning algorithm is applicable on a wide class of vehicles kinematics, selected changing a set of weights.

Multiple Mobile Robots Path-Planning with MCA

In this paper is described a fast path-planner for multi-robot composed by mobile robots having generic shapes and sizes (user defined) and different kinematics. We have developed an algorithm that computes the shortest collision-free path for each robot, from the starting pose to the goal pose, while considering their real shapes, avoiding the collisions with the static obstacles and the other robots. It is based on a directional (anisotropic) propagation of attracting potential values in a 4D space-time, using a multilayered cellular automata (MCA) architecture. This algorithm makes a search for all the optimal collision-free trajectories following the minimum valley of a potential hypersurface embedded in a 5D space

MUREA: A MUlti-Resolution Evidence Accumulation Method for Robot Localization in Known Environments

We present MUREA (MUlti-Resolution Evidence Accumulation): a mobile robot localization method for known 2D environments. It is an evidence accumulation method where the complexity is reduced by means of a multi-resolution scheme. The added value of the contribution, in the authors opinion, are 1) the method per se; 2) the capability of the system to accept both raw sensor data as well as independently generated localization estimates; 3) the capability of the system to give out a (less) accurate estimate whenever asked to do so (e.g. before its regular completion), which could be called any-time localization.

Coralligenous habitat in the Mediterranean Sea: a geomorphological description from remote data

Sea floor mapping along the Apulia continental shelf (Italy) verified the abundance of autochthonous red algae build-ups, mapped as coralligenous habitats (CHs), in a water depth range of 5-100 m. In general, CHs were found to develop three dimensional structures, with a rigid framework and to represent an important geomorphological and sedimentological element on the Mediterranean shelf.Here, we provide the first geomorphological description of CHs (thus poorly categorized) using acoustic data obtained from Side Scan Sonar (SSS) and MultiBeam (MB) echosounder surveys, ground-truthed using a ROV and underwater camera. In SSS mosaics, CHs generally yielded intermediate to high backscatter in response to a rigid cavernous framework. According to the various shapes and the lateral continuity that coralligenous build-ups displayed in explored locations, two distinct textures were determined to be present. Various geomorphological expressions of CHs were noted within our dataset and in images obtained from MB bathymetry. We determined that coralligenous build-ups are typically represented by positive-relief structures that vary from isolated blocks (randomly scattered on a generally flat mobile soft bottom) to a field of blocks (adjacent or even coalescent), and/to ridge with several metres of lateral continuity. In most cases, CHs occurred on flat mobile soft bottom, thus representing an example of coralligenous de plateau.Our results characterize for the first time the CHs through seafloor mapping techniques, which demonstrated to represent an instrumental tool for their geomorphological characterization.

Path-Planning for multiple generic-shaped mobile robots with MCA

In this paper is described a fast Path-Planner for Multi-robot composed by mobile robots having generic shapes and sizes (user defined) and different kinematics. We have developed an algorithm that computes the shortest collision-free path for each robot, from the starting pose to the goal pose, while considering their real shapes, avoiding the collisions with the static obstacles and the other robots. It is based on a directional (anisotropic) propagation of attracting potential values in a 4D Space-Time, using a Multilayered Cellular Automata (MCA) architecture. This algorithm searches for all the optimal collision-free trajectories following the minimum valley of a potential hypersurface embedded in a 5D Time-Space.

Submarine Slide Topography and the Distribution of Vulnerable Marine Ecosystems: A Case Study in the Ionian Sea (Eastern Mediterranean)

In this work, we sought to document how submarine mass-movements influence the submarine landscape and associated habitat distributions on the upper portion of the northern Ionian Margin (eastern Mediterranean Sea) between 200 m to greater than 1,000 m in water depth (w.d.). In this area, mass-wasting processes have created unique morphological forms that, in turn, have generated high diversity for edaphic and hydrogeologic conditions; and these areas are marked by the patchy occurrence of varying natural benthic habitats. Surficial or sub-surficial Mass-Transport Deposits (MTDs) were documented by seismic and high-resolution morpho-bathymetric data and displayed dense aggregation for detached blocks spread over 1,200 km2 between 400 and 1,000 m in w.d.. Living Cold-Water Coral (CWC) communities populate the blocky region and form coral topped mounds. These habitats are important Vulnerable Marine Ecosystems (VMEs) that are exposed to human pressure in the deep sea. Through production of a detailed geomorphological map and an examination of published data on the extent and distribution of CWC communities in the area, we sought to document how comprehensive research into submarine slide topography should also take into account the peculiar characteristics of their biotopes.

Geology of Mar Piccolo, Taranto (southern Italy): the physical basis for remediation of a polluted marine area

Four 1:15,000 maps for the coastal area of Mar Piccolo (Taranto, southern Italy) are presented. The study area is a small, sheltered shallow marine basin of about 20 km2, located north of Taranto town. It contains some submarine, karstic freshwater springs (citri) that have determined the development of intensive aquaculture in the past. Now, the Mar Piccolo is a highly polluted area due to the presence of both military and industrial navy docks and various heavy industries located in proximal areas: (i) the ILVA steel plant in Taranto, the largest in Europe; (ii) the ENI oil refinery and (iii) the CEMENTIR, the largest cement and concrete plant in southern Italy. Many studies show that water and sediments are contaminated (heavy metals, isopropyl alcohol, polychlorinated biphenyl [PCB], etc.), and various remediation projects are now in preparation. In this study, we analyze the physical characteristics of the Mar Piccolo environment by producing several maps: a geological map; a geomorphological map; a bathy-morphological map and a map of the thickness of surficial sediment. All these maps are original products focused on the realization of a reliable geological picture for the Mar Piccolo area. They represent the first steps toward the detailed knowledge of the Mar Piccolo physical environment, which we consider to be a fundamental requirement for developing the most appropriate remediation techniques.