Giacomo Marani

A real-time approach for singularity avoidance in resolved motion rate control of robotic manipulators

In autonomous system, it is important to establish a control scheme that works with stability even near singularity configurations. We describe an online trajectory control scheme that uses the manipulability measure as a distance criteria to avoid manipulator singularities. The proposed approach consists in a method for limiting the minimum value of the distance criteria. The performance is simply affected by the choice of the lower limit. Based on a real-time evaluation of the measure of manipulability, this method does not require a preliminary knowledge of the singular configurations. The proposed algorithm is validated by experimental results.

Future Trends in Marine Robotics [TC Spotlight]

The IEEE Robotics and Automation Society (RAS) Marine Robotics Technical Committee (MRTC) was first established in 2008 following the dismissal of the Underwater Robotics Technical Committee in spring 2008. The goal of the MRTC is to foster research on robots and intelligent systems that extend the human capabilities in marine environments and to promote maritime robotic applications important to science, industry, and defense. The TC organizes conferences, workshops, and special issues that bring marine robotics research to the forefront of the broader robotics community. The TC also introduces its members to the latest development of marine robotics through Web sites and online social media.

Underwater Target Localization

This contribution focuses on the problem, intrinsic to autonomous underwater manipulation, of medium-range target localization for guiding the vehicle toward the target area. Based on the use of the dual-frequency identification sonar (DIDSON) sonar, the goal is to acquire the Earth-referenced Cartesian coordinates of a known target, with the necessary accuracy required for positioning the vehicle, so that the target falls within the manipulator workspace.

Real-Time 3D Sonar Image Recognition for Underwater Vehicles

The recognition of objects and environment are one of keys to automate underwater tasks. This paper presents a predictor based image recognition method using high-resolution sonar images. They are very sensitive to sonars view point changes. The proposed predictor predicts an object images depending on the view point. Using the object model, it modifies a template for optimal recognition. To estimate the accuracy and reliability of the proposed method, indoor tank tests were carried out using various shapes of objects.

Algorithmic singularities avoidance in task-priority based controller for redundant manipulators

In this paper we describe an online solution for avoiding the occurrence of both algorithmic and kinematic singularities in task-priority based kinematic controllers of robotic manipulators. The proposed approach uses a secondary task correction and a successive task projection in order to maintain the measure of manipulability of the correspondent space augmentation approach over a minimum value. It shows a gain in performance and a better task error especially when working in proximity of singular configurations. It is particularly suitable for autonomous systems where an offline trajectory control scheme is often not applicable.

Marine Robotic Systems [From the Guest Editors]

The marine environment is an exciting and challenging context for the robotics community. Autonomous surface vehicles (ASVs) or autonomous underwater vehicles (AUVs) face a demanding environment with poor perception and actuation capabilities in comparison with most ground-based robotics. In the case of the underwater scenario, for example, communications are complicated by the limited bandwidth, and the position measurement of the vehicles is not obvious. Both underwater and surface vehicles, moreover, suffer from the presence of current and wind disturbances that enhance the complexity of the dynamic control task.

Editorial: special issue on marine robotics

The marine environment is an exciting and challenging context for the robotics community. Autonomous underwater and surface vehicles face a demanding environment with poor perception and actuation capabilities with respect to the ground-based robotics. In case of the underwater scenario, for example, communications are complicated by the limited bandwidth, and the position measurement of the vehicles is not obvious. Moreover, the presence of current and wind disturbances enhances the complexity of the dynamic control tasks. With the above difficulties, a successful mission must be supported by themost advanced robot technologies,with particular attention to autonomy. Themarked progress of the last decade in marine technologies and robotics has led to massive improvements ofmarine robotics. The state of the art and some achievements in this area are particularly innovative. The ocean covers about two-thirds of the earth and has a great effect on the future existence of all human beings. In the near future,marine robotswill be used for homeland security, for rise inspection or intelligent sampling, and researchers will be able to deploy numerous networked robotic ocean observatories, expanding the quantity and quality of data