Authors: Faridani, Siamak; Lee, Bryce; Glasscock, Selma; Rappole, John; Song, Dezhen; Goldberg, Ken

Abstract: The scientific field study of wildlife often requires vigilant observation of detailed animal behavior over extended periods. In remote and inhospitable locations, observation can be an arduous, expensive, and dangerous experience for field scientists. We are developing a new class of networked teleoperated robotic "observatories" that allows "citizen scientists" and professional scientists to remotely observe, record, and index animal activity and behaviors via the internet. This paper describes CONE-Welder, installed at the Rob & Bessie Welder Wildlife Foundation in Texas to gather photographic and quantitative data for a biological study of avian activity and hypothesized range change for selected subtropical bird species. Since the system was deployed on 12 May 2008, over 600 users ("players") have participated online. Players have requested over 2.2 million camera frames and captured over 29,000 photographs. Within these photos, citizen scientists have classified 74 unique species, including eight avian species previously unknown to have breeding populations within the region. The collected dataset quantifies seasonal presence of birds of particular interest, e.g., the Green Jay (Cyanocorax incas). This paper describes the system architecture, the game interface that provides incentives for player participation, and initial data collected. CONE-Welder is available online at: http://cone.berkeley.edu/

Keywords: Networked robots; Tele-robotics, tele-presence

Identifier: 10.3182/20091006-3-US-4006.00010

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Sun, Wei; Chen, YangQuan

Abstract: Scale-free network and consensus among multiple agents have both drawn quite much attention. To investigate the consensus speed over scale-free networks is the main topic in this paper. Given a set of different values for the power-law distribution parameter $gamma$, and a set of different values for the minimum degree ($d_{min}$) for the nodes, the algebraic connectivity ($lambda_2$) of the network topology is studied, as well as the time ($t_c$) (or iteration ($k_c$), for discrete algorithm) taken to reach consensus. The results exhibit that $lambda_2$ decreases while $gamma$ increases. The $lambda_2$ increases monotonically as $d_{min}$ grows, and they fit very well in a linear relationship. $t_c$ (or $k_c$) decreases as $gamma$ reduces and $d_{min}$ increases. Via observing the behavior of the largest eigenvalue ($lambda_n$) of the Laplacian of the network topology, we draw the conclusion that the robustness over time delays declines while the robustness over node-failures and edge-failures increases.

Keywords: Networked robots; Mobile sensor networks; Mobile ad hoc networks

Identifier: 10.3182/20091006-3-US-4006.00013

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Frew, Eric W.; Dixon, Cory; Elston, Jack; Stachura, Maciej

Abstract: This paper describes an information-theoretic framework for active sensing by unmanned aircraft systems in realistic communication environments. The position dependency of wireless networked communication is modeled using the standard empirical radio model in combination with Shannon capacity or a packet erasure channel. The covariance of the extended information filter is used to model sensed information content. The two information-theoretic concepts are then combined into a single optimization metric. Decentralized control laws are developed for simplified network scenarios. Stochastic approximation and extremum seeking control techniques are used to estimate the gradient of the sampled objective function. Experimental flight results demonstrate the capabilities of the active sensing framework.

Keywords: Networked UAVs; Mobile sensor networks; Mobile ad hoc networks

Identifier: 10.3182/20091006-3-US-4006.00011

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: None

Abstract:

Keywords:

Identifier: 10.3182/20091006-3-US-4006.90003

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Weiss, Manoja; Moore, Kevin L.

Abstract: An autonomous Mobile Radio (AMR) in a wireless network is a mobile robot with wireless communication capability whose mission is to achieve a network communications goal through control of its position. Wireless tethering is an AMR behavior for ensuring the quality of wireless links between an AMR and other nodes. We discuss the particular problem of autonomously penetrating a tunnel environment using wirelessly tethered AMRs. Using a realistic, experimentally-derived radio signal propagation model in an underground environment, we present a method of implementing tethering using a consensus variable protocol for motion control as well as a method of estimating the coverage range.

Keywords: Communication algorithms; Networked robots; Tele-operations, tele-maintenance

Identifier: 10.3182/20091006-3-US-4006.00006

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Broberg, Jacob Honoré; Hede, Søren Thorhauge; Mikkelsen, Simon; Pedersen, Jesper; Sørensen, Christian Bräuner; Madsen, Per Printz; Ole Elenius Meilvang Borch, Ole Borch

Abstract: In many applications multiple robots in Mobile Ad-hoc Networks are required to collaborate in order to solve a task. This paper shows by proof of concept that a Collaboration Layer can be modelled and designed to handle the collaborative communication, which enables robots in small to medium size networks to solve tasks collaboratively. In this proposal the Collaboration Layer is modelled to handle service and position discovery, group management, and synchronisation among robots, but the layer is also designed to be extendable. Based on this model of the Collaboration Layer, generic services are provided to the application running on the robot. The services are generic because they can be used by many different applications, independent of the task to be solved. Likewise, specific services are requested from the underlying Virtual Machine, such as broadcast, multicast, and reliable unicast. A prototype of the Collaboration Layer has been developed to run in a simulated environment and tested in an evaluation scenario. In the scenario five robots solve the tasks of vacuum cleaning and entrance guarding, which involves the ability to discover potential co-workers, form groups, shift from one group to another, and communicate among group members. The successful outcome of the evaluation scenario indicates that a generic Collaboration Layer may be realisable.

Keywords: Communication algorithms; Networked robots; Mobile ad hoc networks

Identifier: 10.3182/20091006-3-US-4006.00018

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Lee, Taekyung; Ahn, Hyo-Sung

Abstract: In this paper, control method for mobile manipulator subjected to kinematic constraint is proposed. It makes difficult to control mobile manipulator that nonholonomic constraints on the mobile platform and the dynamic interaction. The neural network is used to estimate mobile manipulator dynamics with the dynamic interaction by on-line learning rule. The stability of the closed-loop system, the convergence of the neural network weightupdating process and boundeness of the neural network weight estimation error are guaranteed by Lyapunov theory.

Keywords: Robotics; Autonomous decision-making and control

Identifier: 10.3182/20091006-3-US-4006.00007

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Schioeler, Henrik; Ngo, Trung Dung; Nielsen, Jens Dalsgaard

Abstract: Clock synchronization in swarms of networked mobile robots is studied in a probabilistic, epidemic framework. In this setting communication and synchonization is considered to be a randomized process, taking place at unplanned instants of geographical rendezvous between robots. In combination with a Markovian mobility model the synchronization process yields overall evolutionary dynamics for first and second conditional moments of synchronization error given geographical position. The established dynamics assume the shape of partial integro-differential equations and the swarm is subsequently studied as an infinite-dimensional optimal control problem. Illustrative numerical examples are given and commented.

Keywords: Networked robots; Mobile ad hoc networks; Robotics

Identifier: 10.3182/20091006-3-US-4006.00008

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Ahn, Hyo-Sung; Ryu, Jeha

Abstract: This paper addresses a synchronization scheme of multi-input and multi-output (MIMO) teleoperation systems when there exists a time delay during signal transfer between the master and slave devices. Without any passivity assumption, exponentially convergence will be ensured. Through a numerical simulation, the validity of the proposed methods will be illustrated.

Keywords: Tele-operations, tele-maintenance; Tele-robotics, tele-presence

Identifier: 10.3182/20091006-3-US-4006.00015

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Adams, Joshua; Sun, Wei; Chen, YangQuan

Abstract: Centroidal Voronoi tessellations (CVTs) have recently attracted attention as a method for generating emergent behavior and swarm intelligence, for instance efficiently locating a source and creating evenly distributed formations. Previous research has focused on a centralized algorithm which depends on a base station computer to perform calculations and give the robotic agents direct movement commands. This research attempts to create an adaptive decentralized procedure for autonomous agents to create formations using CVTs. This decentralized approach will allow swarm systems a greater level of autonomy by removing the dependence on a centralized base station for calculating common agent tasks.

Keywords: Mobile sensor networks; Networked robots; Mobile sensor-actuator networks (MAS-NET)

Identifier: 10.3182/20091006-3-US-4006.00003

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Zeiger, Florian; Sauer, Markus; Stolz, Lothar; Schilling, Klaus

Abstract: Modern applications of mobile robot teams or robot teleoperation often demand wireless any-to-any communication in combination with highly dynamical network topologies to accomplish more and more complex tasks. These communication systems should also not rely on any pre-existing infrastructure, have low costs, and should allow for a seamless integration into existing communication networks. The well tested technology IEEE 802.11 wireless LAN offers all these possibilities. Especially the capability of realizing ad-hoc networks offers a high potential for WLAN to be used in the area of networked robots. Mesh networks and mobile ad-hoc networks are able to provide mechanisms for realizing stable communication links for networked robots. This work gives a brief overview on mesh networks and ad-hoc networks and further shows the behavior of different ad-hoc routing protocols (AODV, OLSR, DSR, BATMAN) in typical scenarios for remote operation of mobile robots. Also the differences between the application scenarios of mobile robot teams and in pure telecommunication environments are explained. The presented results are not only based on simulations. The ad-hoc routing protocols are compared in test scenarios with real mobile robot hardware experiments and the analysis is done according to well established methods and valid metrics well known from literature. Hints for the setup and parameter tuning of selected ad-hoc routing protocols are given to enable a better teleoperation of mobile robots and to improve the communication inside teams of mobile robots and humans. Finally a first approach is presented how to increase the system performance also on the application layer.

Keywords: Mobile ad hoc networks; Networked robots; Telematics methods

Identifier: 10.3182/20091006-3-US-4006.00019

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Pack, Daniel

Abstract: Unmanned aerial vehicles (UAVs) play an increasingly important role in a large number of military applications. Frequently deployed for intelligence collection (e.g., surveillance and reconnaissance), they are also useful for establishing long-range communication and providing tactical support. The focus of our research lies on the design and development of autonomous, cooperative UAVs using distributed control, sensing, and communication technologies. In this paper, we present several UAV technologies we developed that enable a team of UAVs to autonomously search, detect, and locate stationary ground targets using airborne sensors. These enabling technologies include: (1) distributed, cooperative control of UAVs, (2) a novel out-of-order sigma-point Kalman filtering method for local fusion of multiview sensor data collected by different UAVs from varying perspectives, (3) a dynamic air-to-air and air-to-ground communication network, and (4) a UAV operating system to manage control, sensing, and communication activities. We illustrate the capabilities of this cooperative UAV system with test data acquired in ight demonstrations.

Keywords: Networked UAVs; Autonomous decision-making and control; Mobile sensor networks

Identifier: 10.3182/20091006-3-US-4006.00012

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Sinha, Arpita; Tsourdos, Antonios; White, Brian A.

Abstract: In this paper, we develop a mechanism to detect, model and track the shape of a contaminant cloud boundary using air borne sensor swarms. The cloud consists of a transparent gas of nuclear, biological or chemical contaminants and is spreading slowly in an urban environment. A group of UAVs, having the required sensors, are made to fly through the cloud to detect the boundary of the cloud. The shape of the cloud is modeled using splinegon. An observer is designed to track the movement of the cloud. The output of the observer is used in the path planning of the UAVs. The path planning is online, decentralized and considers obstacle avoidance and connectivity maintenance among the UAVs. Simulated experiments are carried out to test the proposed cloud tracking algorithm.

Keywords: Mobile sensor networks; Autonomous decision-making and control; Networked UAVs

Identifier: 10.3182/20091006-3-US-4006.00002

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Seol, Jae-Young; Kim, Seong-Lyun

Abstract: The end-to-end throughput of stationary random wireless networks is scaled by £(p 1 n log n ). This throughput scale can be changed into £(1) by making the °ows to be local °ow patterns. By exploiting the controllable mobility of mobile nodes in order to reduce the path length, it is possible to achieve the constant scale end-to-end capacity regardless of the node density. Since the shortened path length contributes the decrease of the number of hop counts the number of relaying packets, this reduces the tra±c delay and improves the energy e±ciency at the same time. The mobility control for the constant throughput scale can be formulated as a optimization problem, and we propose a simple heuristic mobility control algorithm based on the analysis and the problem formulation. Extensive simulation results show that the proposed mobility control algorithm improve the end-to-end capacity.

Keywords: Mobile ad hoc networks; Communication algorithms; Networked robots

Identifier: 10.3182/20091006-3-US-4006.00017

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Hess, Martin; Schilling, Klaus

Abstract: This paper deals with the rendezvous for groups of car-like mobile robots. In the main part of this work we solve the rendezvous problem for bounded steering vehicles by applying discontinuous feedback control in combination with a specific switching logic. This logic commands certain vehicles to perform orientation adjusting maneuvers that drive the system out of undesired equilibria. The developed control system is demonstrated in several laboratory hardware experiments.

Keywords: Control of networks; Networked robots

Identifier: 10.3182/20091006-3-US-4006.00009

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Cardozo, Eleri; Guimarães, Eliane; Paolieri-Neto, Fernando; Pinto, Victor

Abstract: This paper presents the architecture and implementation of REALabs-BOT, a WebLab in mobile robotics. REALabs-BOT was designed to run over high speed networks. As such, mobile robotics experiments run on the user's computer and control the robots over the network and in real time. The proposal of the WebLab is to let the student to develop his/her robotic algorithm in Java or Javascript, to tune and evaluate the algorithm in a simulated environment, and finally to run exactly the same algorithm to drive the real robots. REALabs-BOT maintains a repository of robotic experiments for demonstration purposes and as starting point for new experiments. The WebLab also supports secure interaction from multiple users located at different sites.

Keywords: Tele-robotics, tele-presence; Networked robots; Tele-operations, tele-maintenance

Identifier: 10.3182/20091006-3-US-4006.00014

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Maxim, Paul M.; Spears, William; Spears, Diana

Abstract: One important task in cooperative robotics is the self-organization of robotic chain formations in unknown environments. Surveillance and reconnaissance in sewers, ducts, tunnels, caves or narrow passageways, in general, are some of the applications for this type of formation. Previously we have provided simulation results for a novel chain formation algorithm that addresses this task. This paper presents the results of the chain formation algorithm implementation on five robots.

Keywords: Communication algorithms; Remote sensor data acquisition; Networked robots

Identifier: 10.3182/20091006-3-US-4006.00004

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Kim, Jonghoek; Zhang, Fumin; Egerstedt, Magnus

Abstract: We develop a strategy that enables multiple intelligent vehicles to cooperatively explore complex territories. Every vehicle deploys communication devices and expands an information network while constructing a topological map based on Voronoi diagrams. As the information network weaved by each vehicle grows, intersections eventually happen so that the topological maps are shared. This allows for distributed vehicles to share information with other vehicles that have also deployed communication devices. Our exploration algorithms are provably complete under mild technical assumptions. A performance analysis of the algorithms shows that in a bounded workspace, the time spent to complete the exploration decreases as the number of vehicles increases. We further provide an analytical formula for this relationship. Time e±ciency of the algorithms is demonstrated in MATLAB simulation.

Keywords: Control through networks; Robot path planning; Communication algorithms

Identifier: 10.3182/20091006-3-US-4006.00001

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Ducatelle, Frederick; Förster, Alexander; Di Caro, Gianni; Gambardella, Luca Maria

Abstract: In this paper we study a problem of navigation in networked multi-robot systems. The robots are deployed in a confined area, where they move around and solve tasks. They communicate with each other through an infrared communication device, so that an ad hoc network is formed among them. Due to the limited range and line of sight nature of the infrared communication, this network has intermittent connectivity. The question we address is how a particular robot can use this network to find a target location that is indicated by another robot (e.g., the other robot has identified a task to be serviced by the searching robot). All other robots are involved in tasks of their own, and do not change their movements to help the searching robot find its destination. However, they do offer support by forwarding messages over the network. We propose a new algorithm based on routing in ad hoc and delay tolerant networks that can run on the network formed between the robots and provide navigation information to the searching robot. We evaluate the validity of our approach both in simulation and through an implementation on a group of 16 e-puck robots.

Keywords: Networked robots; Robot path planning; Mobile ad hoc networks

Identifier: 10.3182/20091006-3-US-4006.00005

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: None

Abstract:

Keywords:

Identifier: 10.3182/20091006-3-US-4006.90002

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: Sauer, Markus; Hess, Martin; Schilling, Klaus

Abstract: Lack of situation awareness significantly decreases the performance in missions where a mobile robot is operated by a human from remote. The user interface is a key influencing element for situation awareness of the human operator. The information from the remote site is limited to what the robot’s sensors can provide. In addition, this information is in general only delivered with a certain - maybe varying - communication delay. Predictive displays provide a promising approach to cope with these problems. In order to increase the situation awareness for the human operator in teleoperation scenarios predictive user interfaces can be used to achieve an artificial excoentric view. This work presents an approach how a predictive mixed reality user interface can be realized with the help of motion control theory. The human operator commands a virtual robot projected into the camera image delivered to the human operator from the physical robot. Hereby a trajectory for the real physical robot is generated, which is executed by the physical robot after a certain time. Combined with mixed reality technologies an artificial, exocentric view of the mobile robot is achieved which leads to a short time predictive user interface for mobile-robot teleoperation.

Keywords: Tele-operations, tele-maintenance; Tele-robotics, tele-presence; Remote control

Identifier: 10.3182/20091006-3-US-4006.00016

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009

Authors: None

Abstract:

Keywords:

Identifier: 10.3182/20091006-3-US-4006.90001

Conference: 2009 IFAC Workshop on Networked Robotics

Location: Colorado School of Mines, United States of America

Start Date: Tue Oct 06 2009 - End Date: Thu Oct 08 2009