Search results for "working"

Fundamentals of Paleoimaging Techniques: Bridging the Gap Between Physicists and Paleopathologists

2011

Design and control of a novel 3D casting manipulator

2010

This paper focuses on casting manipulation and presents an innovative mechanism that allows objects placed in a three-dimensional space to be reached with a relatively small robot. Casting manipulation is a technique by which a robotic end-effector is thrown and its ballistic flight is controlled through a tether cable so as to reach a target object. Previous work presented a solution that is viable only when the position of the target object is perfectly known or aligned with the throwing plane. Our work extends the technique by use of a novel mechanical design of the arm, and a suitable control scheme for the flight of the end-effector, which makes it applicable for objects placed at gene…

Visual-based Feedback Control of Casting Manipulation

2006

In this paper, we present a method to control casting manipulation by means of real-time visual feedback. Casting manipulation is a technique to deploy a robotic end-effector at large distances from the robot’s base, by throwing the end-effector and controlling its ballistic flight using forces transmitted through a light tether connected to the end-effector itself. The tether cable can also be used to retrieve the end-effector and exert forces on the robot’s environment. Previous work has shown that casting manipulation is able to catch objects at a large distance, proving it viable for applications such as sample acquisition and return, rescue, etc. In previous experiments, the position o…

Energy Efficient Resource Allocation for OFDMA Two-Way Relay Networks with Channel Estimation Error

2015

In this work, we consider the practical issues of resource allocation problem in OFDMA two-way relay networks: the inaccuracy of channel-state information (CSI) available to the transmitters. Instead, only the estimated channel status is known by the transmitters. In this context, a joint optimization of subcarrier pairing and allocation, relay selection and transmit power allocation is formulated in the OFDMA two-way amplify-and-forward relay networks. Moreover, to ensure the Quality of Service (QoS) requirement, the energy consumption must be minimized without compromising the QoS. Therefore, by applying convex optimization techniques, energy efficient algorithms are developed with the ob…

A Novel Wideband MIMO Car-to-Car Channel Model Based on a Geometrical Semi-Circular Tunnel Scattering Model

2016

In this paper, we present a wideband multiple-input multiple-output (MIMO) car-to-car (C2C) channel model based on a geometrical semi-circular tunnel (SCT) scattering model. From the geometrical SCT scattering model, a reference channel model is derived under the assumption of single-bounce scattering in line-of-sight (LOS) and non-LOS (NLOS) propagation environments. In the proposed reference channel model, it is assumed that an infinite number of scatterers are randomly distributed on the tunnel wall. Starting from the geometrical scattering model, the time-variant transfer function (TVTF) is derived, and its correlation properties in time, frequency, and space are studied. Expressions ar…

Scalable and Privacy-Preserving Admission Control for Smart Grids

2015

International audience; Energy demand and production need to be constantly matched in the power grid. The traditional paradigm to continuously adapt the production to the demand is challenged by the increasing penetration of more variable and less predictable energy sources, like solar photovoltaics and wind power. An alternative approach is the so called direct control of some inherently flexible electric loads to shape the demand. Direct control of deferrable loads presents analogies with flow admission control in telecommunication networks: a request for network resources (bandwidth or energy) can be delayed on the basis of the current network status in order to guarantee some performanc…

Dynamic characterization for the dielectric electroactive polymer fundamental sheet

2012

Published version of an article published in the journal: International Journal of Advanced Manufacturing Technology. Also available from the publisher at: http://dx.doi.org/10.1007/s00170-012-4423-6 A study into the appropriateness of characterizing the dynamics of the dielectric electroactive polymer (DEAP) fundamental sheet has been performed. Whereby a model describing the dynamics of the DEAP fundamental sheet is developed, parameters of the models are determined using experimental/simulation results, and verification has been conducted to determine the precision of the dynamic model. The precision for the DEAP sheet-obtained dynamic model could not be verified unless some parameters c…

RF-based node system for blind navigation in running activities

2008

The system presented is oriented for use by blind adults or children in running activities at a stadium or an analogical large space. The system dynamically provides a blind person with navigation related information. Radio signal strength measurements are used in localization task. The system makes a blind person more independent in sport, eliminating the need in explicit human assistance.

OLSR Mesh Networks for Broadband Access: Enhancements, Implementation and Deployment

2008

In the context of an EU FP6 project, ADHOCSYS, we have developed a reliable and cost-effective solution for broadband Internet access in rural and mountainous areas. This solution is built based on multi-hop wireless mesh networking technologies and covers many aspects such as routing, reliability, QoS, security, self-configuration, self-healing, remote network monitoring, power management etc. In this paper, we present solely the routing aspect of the developed mesh network, focusing on new routing features that have been designed, implemented, and deployed in a real-life operational network. These new features are developed based on an extended version of the OLSR protocol. The test resul…

Secondary substation power line communications for medium voltage smart grids

2012

In this paper a performance analysis is carried out, in order to evaluate the possibility to employ power line communication (PLC) between secondary substations of a medium voltage (MV) distribution networks in a smart grid. The study is focused on the analysis of PLC technologies and the evaluation of the influence quantities on the communication performance in the most common case of by-pass connection at MV bus-bars of secondary substations. Different quantities have been analyzed as modulation techniques, requested bandwidth and bitrate, coupling device and system attenuation versus frequency in order to find the best solution for a reliable communication system. A complete model of a r…