Event-based device-behavior switching in surgical human-robot interaction

In present days, the number of application in which robots and users share the same workspace is increasing, as long as the need of cooperation between them. To achieve a smooth cooperation, in particular in surgical applications, the robot needs to timely change its behavior to adapt to the needs of the user. In this work, a simplified scenario for neurosurgery was defined in which the user interacts with the robot through a Graphical User Interface (GUI) and by touching the robot links and, based to those events and on the current status, different control modes are enabled in the high level controller we developed, such as autonomous, cooperative and teleoperation. Experiments were performed to measure the performances and safety of the developed high level controller in handling the transitions between two states by checking the continuity of data from the robot and from an external measurement system. Results proved that the trajectories of the end effector and links during the switching phase are continuous and thus the modular high level controller developed switches control safely without undesired deviation from desired course

Range-only SLAM with a mobile robot and a Wireless Sensor Networks

This paper presents the localization of a mobile robot while simultaneously mapping the position of the nodes of a Wireless Sensor Network using only range measurements. The robot can estimate the distance to nearby nodes of the Wireless Sensor Network by measuring the Received Signal Strength Indicator (RSSI) of the received radio messages. The RSSI measure is very noisy, especially in an indoor environment due to interference and reflections of the radio signals. We adopted an Extended Kalman Filter SLAM algorithm to integrate RSSI measurements from the different nodes over time, while the robot moves in the environment. A simple pre-processing filter helps in reducing the RSSI variations due to interference and reflections. Successful experiments are reported in which an average localization error less than 1 m is obtained when the SLAM algorithm has no a priori knowledge on the wireless node positions, while a localization error less than 0.5 m can be achieved when the position of the node is initialized close to the their actual position. These results are obtained using a generic path loss model for the transmission channel. Moreover, no internode communication is necessary in the WSN. This can save energy and enables to apply the proposed system also to fully disconnected networks

Distributed Control Architecture

This document describes the development and testing of a novel Distributed Control Architecture (DCA). The DCA developed during the study is an attempt to turn the components used to construct unmanned vehicles into a network of intelligent devices, connected using standard networking protocols. The architecture exists at both a hardware and software level and provides a communication channel between control modules, actuators and sensors. A single unified mechanism for connecting sensors and actuators to the control software will reduce the technical knowledge required by platform integrators and allow control systems to be rapidly constructed in a Plug and Play manner. DCA uses standard networking hardware to connect components, removing the need for custom communication channels between individual sensors and actuators. The use of a common architecture for the communication between components should make it easier for software to dynamically determine the vehicle s current capabilities and increase the range of processing platforms that can be utilised. Implementations of the architecture currently exist for Microsoft Windows, Windows Mobile 5, Linux and Microchip dsPIC30 microcontrollers. Conceptually, DCA exposes the functionality of each networked device as objects with interfaces and associated methods. Allowing each object to expose multiple interfaces allows for future upgrades without breaking existing code. In addition, the use of common interfaces should help facilitate component reuse, unit testing and make it easier to write generic reusable software

XML and Web Services for Astronomers

This tutorial will be a conceptual introduction to XML technologies and their use in Web services, with examples and applications taken from astronomy. It will be assumed that the audience is familiar with HTML as well as concepts of object-oriented programming. The programming examples will use Java, although this will be a small part of the total material. Upon completing this tutorial, the student should be able to read and write XML documents, create XML Schemas and XSL Transformations, programmatically consume and create XML documents, and build a simple Web service