Person:

Howard, Ayanna M.

Permanent Link

https://hdl.handle.net/1853/72195

Associated Organization(s)

Organizational Unit

School of Interactive Computing

Organizational Unit

School of Electrical and Computer Engineering

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Publication Search Results

Now showing 1 - 8 of 8

Automatic Generation of Persistent Formations for Multi-Agent Networks Under Range Constraints

(Georgia Institute of Technology, 2009-06) Smith, Brian Stephen ; Egerstedt, Magnus B. ; Howard, Ayanna M.

In this paper we present a collection of graph-based methods for determining if a team of mobile robots, subjected to sensor and communication range constraints, can persistently achieve a specified formation. What we mean by this is that the formation, once achieved, will be preserved by the direct maintenance of the smallest subset of all possible pairwise inter-agent distances. In this context, formations are defined by sets of points separated by distances corresponding to desired inter-agent distances. Further, we provide graph operations to describe agent interactions that implement a given formation, as well as an algorithm that, given a persistent formation, automatically generates a sequence of such operations. Experimental results are presented that illustrate the operation of the proposed methods on real robot platforms.
Automatic Formation Deployment of Decentralized Heterogeneous Multiple-Robot Networks with Limited Sensing Capabilities

(Georgia Institute of Technology, 2009-05) Smith, Brian Stephen ; Wang, Jiuguang ; Egerstedt, Magnus B. ; Howard, Ayanna M.

Heterogeneous multi-robot networks require novel tools for applications that require achieving and maintaining formations. This is the case for distributing sensing devices with heterogeneous mobile sensor networks. Here, we consider a heterogeneous multi-robot network of mobile robots. The robots have a limited range in which they can estimate the relative position of other network members. The network is also heterogeneous in that only a subset of robots have localization ability. We develop a method for automatically configuring the heterogeneous network to deploy a desired formation at a desired location. This method guarantees that network members without localization are deployed to the correct location in the environment for the sensor placement.
Automatic Deployment and Formation Control of Decentralized Multi-Agent Networks

(Georgia Institute of Technology, 2008-05) Smith, Brian Stephen ; Egerstedt, Magnus B. ; Howard, Ayanna M.

Novel tools are needed to deploy multi-agent networks in applications that require a high degree of accuracy in the achievement and maintenance of geometric formations. This is the case when deploying distributed sensing devices across large spatial domains. Through so-called Embedded Graph Grammars (EGGs), this paper develops a method for automatically generating control programs that ensure that a multi-robot network is deployed according to the desired configuration. This paper presents a communication protocol needed for implementing and executing the control programs in an accurate and deadlock-free manner.
Automatic Deployment and Formation Control of Decentralized Multi-Agent Networks

(Georgia Institute of Technology, 2008-05) Smith, Brian Stephen ; Howard, Ayanna M. ; Egerstedt, Magnus B.

Novel tools are needed to deploy multi-agent networks in applications that require a high degree of accuracy in the achievement and maintenance of geometric formations. This is the case when deploying distributed sensing devices across large spatial domains. Through so-called embedded graph grammars (EGGs), this paper develops a method for automatically generating control programs that ensure that a multi-robot network is deployed according to the desired configuration. This paper presents a communication protocol needed for implementing and executing the control programs in an accurate and deadlock-free manner.
A Single Camera Terrain Slope Estimation Technique for Natural Arctic Environments

(Georgia Institute of Technology, 2008-05) Smith, Brian Stephen ; Howard, Ayanna M.

Arctic regions present one of the harshest environments on earth for people or mobile robots, yet many important scientific studies, particularly those involving climate change, require measurements from these areas. For the successful deployment of mobile sensors in the arctic, a reliable, fault tolerant, low-cost method of navigating must be developed. One aspect of an autonomous navigation system must be an assessment of the local terrain, including the slope of nearby regions. Presented here is a method of estimating the slope of the terrain in the robot's coordinate frame using only a single camera, which has been applied to both simulated arctic terrain and real images. The slope estimates are then converted into the global coordinate frame using information from a roll sensor, used as an input to a fuzzy logic navigation scheme, and tested in a simulated arctic environment.
Automatic Generation of Persistent Formations for Multi-Agent Networks Under Range Constraints

(Georgia Institute of Technology, 2007-10) Smith, Brian Stephen ; Egerstedt, Magnus B. ; Howard, Ayanna M.

We present graph-based methods for determining if a mobile robot network with a defined sensor and communication range can persistently achieve a specified formation, which implies that the formation, once achieved, will be preserved by the direct maintenance of a subset of inter-agent distances. Here, formations are defined by a set of points whose inter-point distances correspond to desired inter-agent distances. Further, we provide graph operations to describe agent interactions that implement a given formation, as well as an algorithm that, given a persistent formation, automatically generates a sequence of such operations.
Realization of the Sensor Web Concept for Earth Science Using Mobile Robotic Platforms

(Georgia Institute of Technology, 2007-03) Howard, Ayanna M. ; Smith, Brian Stephen ; Egerstedt, Magnus B.

In this paper, we discuss the realization of a robotic mobile sensor network that allows for controlled reconfiguration of sensor assets in a decentralized manner. The motivation is to allow the construction of a new system of in-situ science observations that requires higher spatial and temporal resolution models that are needed for expanding our understanding of Earth system change. These observations could enable recording of spatial and temporal variations in environmental parameters required for such activities as monitoring of seismic activity, monitoring of civil and engineering infrastructures, and detection of toxic agents throughout a region of interest. The difficulty in establishing these science observations are that global formation properties must be achieved based on the local interactions between individual sensors. As such, we present a novel approach that allows for the sensor network to function in a decentralized manner and is thus able to achieve global formations despite individual sensor failure, limitations in communication range, and changing scientific objectives. Details on the sensing and control algorithms for controlled reconfiguration will be discussed and results of field deployment will be presented.
Realization of the Sensor Web Concept for Earth Science Using Mobile Robotic Platforms

(Georgia Institute of Technology, 2007-03) Howard, Ayanna M. ; Smith, Brian Stephen ; Egerstedt, Magnus B.

In this paper, we discuss the realization of a robotic mobile sensor network that allows for controlled reconfiguration of sensor assets in a decentralized manner. The motivation is to allow the construction of a new system of in-situ science observations that requires higher spatial and temporal resolution models that are needed for expanding our understanding of Earth system change. These observations could enable recording of spatial and temporal variations in environmental parameters required for such activities as monitoring of seismic activity, monitoring of civil and engineering infrastructures, and detection of toxic agents throughout a region of interest. The difficulty in establishing these science observations are that global formation properties must be achieved based on the local interactions between individual sensors. As such, we present a novel approach that allows for the sensor network to function in a decentralized manner and is thus able to achieve global formations despite individual sensor failure, limitations in communication range, and changing scientific objectives. Details on the sensing and control algorithms for controlled reconfiguration will be discussed and results of field deployment will be presented.