Taylor, Camillo J

Email Address
ORCID
Disciplines
Research Projects
Organizational Units
Position
Introduction
Research Interests

Filters

35
2393
Reset filters

Settings

Search Results

Now showing 1 - 10 of 35
  • Publication
    On the Optimal Assignment of Conference Papers to Reviewers
    (2008-01-01) Taylor, Camillo J
  • Publication
    Target Tracking With Distributed Sensors: The Focus of Attention Problem
    (2003-01-01) Isler, Volkan; Khanna, Sanjeev; Spletzer, John; Taylor, Camillo J
    In this paper, we investigate data fusion techniques for target tracking using distributed sensors. Specifically, we are interested in how pairs of bearing or range sensors can be best assigned to targets in order to minimize the expected error in the estimates. We refer to this as the focus of attention (FOA) problem. In its general form, FOA is NP-hard and not well approximable. However, for specific geometries we obtain significant approximation results: a 2-approximation algorithm for stereo cameras on a line, a PTAS for when the cameras are equidistant, and a 1.42 approximation for equally spaced range sensors on a circle. In addition to constrained geometries, we further investigate the problem for general sensor placement. By reposing as a maximization problem -- where the goal is to maximize the number of tracks with bounded error -- we are able to leverage results from maximum set-packing to render the problem approximable. We demonstrate these in simulation for a target tracking task, and for localizing a team of mobile agents in a sensor network. These results provide insights into sensor/target assignment strategies, as well as sensor placement in a distributed network.
  • Publication
    Target Tracking with Distributed Sensors: The Focus of Attention Problem
    (2003-10-27) Isler, Volkan; Khanna, Sanjeev; Spletzer, John R.; Taylor, Camillo J
    In this paper, we investigate data fusion techniques for target tracking using distributed sensors. Specifically, we are interested in how pairs of bearing or range sensors can be best assigned to targets in order to minimize the expected error in the estimates. We refer to this as the focus of attention (FOA) problem. In its general form, FOA is NP-hard and not well approximable. However, for specific geometries we obtain significant approximation results: a 2-approximation algorithm for stereo cameras on a line, a PTAS for when the cameras are equidistant, and a 1.42 approximation for equally spaced range sensors on a circle. By reposing as a maximization problem - where the goal is to maximize the number of tracks with bounded error - we are able to leverage results from maximum set-packing to render the problem approximable. We demonstrate the results in simulation for a target tracking task, and for localizing a team of mobile agents in a sensor network. These results provide insights into sensor/target assignment strategies, as well as sensor placement in a distributed network.
  • Publication
    The Cyclops Vision System
    (1989-04-01) Buhler, Martin; Taylor, Camillo J; Vlamis, N.; Ganz, A.
    Cyclops is a distributed real-time vision system. It is "real-time" as for most vision tasks, it can be configured with enough processing nodes as to allow an update rate of 60 Hz with a maximum latency of 1/30s. This allows the system to be used directly as a feedback sensor for motion control. Even though Cyclops was built originally for tracking objects in 3D at 60Hz, it offers great flexibility. It can be configured to attack many vision tasks at much higher rates than was previously possible with systems that are up to an order of magnitude more expensive. For more information: Kod*lab
  • Publication
    A Vision-Based Formation Control Framework
    (2002-10-01) Das, Aveek K.; Kumar, Vijay; Fierro, Rafael; Ostrowski, James P.; Taylor, Camillo J.; Spletzer, John
    We describe a framework for cooperative control of a group of nonholonomic mobile robots that allows us to build complex systems from simple controllers and estimators. The resultant modular approach is attractive because of the potential for reusability. Our approach to composition also guarantees stability and convergence in a wide range of tasks. There are two key features in our approach: 1) a paradigm for switching between simple decentralized controllers that allows for changes in formation; 2) the use of information from a single type of sensor, an omnidirectional camera, for all our controllers. We describe estimators that abstract the sensory information at different levels, enabling both decentralized and centralized cooperative control. Our results include numerical simulations and experiments using a testbed consisting of three nonholonomic robots.
  • Publication
    Distributed Sensor Databases for Multi-Robot Teams
    (2004-04-26) Cowley, Anthony; Hsu, Hwa-Chow; Taylor, Camillo J
    In this paper we describe our implementation of a distributed sensor database that was designed to support the activities of teams of mobile robots as they explore an environment. Importantly, this approach effectively separates the process of acquiring sensor data from that of exploiting it. This allows us to develop applications where robots and human users can automatically discover and utilize sensor measurements acquired by other robots in the team. We also explain our approach to implementing distributed queries, an important capability that allows us to perform queries in a way that makes best use of the limited available communication bandwidth. Finally, we briefly describe how we have used this system to support situational awareness tasks.
  • Publication
    Synergies in Feature Localization by Air-Ground Robot Teams
    (2004-06-18) Kumar, R. Vijay; Grocholsky, Ben; Taylor, Camillo J; Bayraktar, Selcuk; Pappas, George J
    This paper describes the implementation of a decentralized architecture for autonomous teams of aerial and ground vehicles engaged in active perception. We provide a theoretical framework based on an established approach to the underlying sensor fusion problem [3]. This provides transparent integration of information from heterogeneous sources. The approach is extended to include an information-theoretic utility measure that captures the task objective and robot inter-dependencies. A distributed solution mechanism is employed to determine information maximizing trajectories and assignments subject to the constraints of individual vehicle and sensor sub-systems. This architecture enables the benefit of the complementary aerial and ground based vehicle and sensor capabilities to be realized. The approach is applied to missions involving searching for and tracking multiple ground targets. Experimental results for vehicles equipped with cameras are presented. These illustrate the impact of the team configuration on overall system performance.
  • Publication
    Solving Image Registration Problems Using Interior Point Methods
    (2008-10-12) Taylor, Camillo J; Bhusnurmath, Arvind
    This paper describes a novel approach to recovering a parametric deformation that optimally registers one image to another. The method proceeds by constructing a global convex approximation to the match function which can be optimized using interior point methods. The paper also describes how one can exploit the structure of the resulting optimization problem to develop efficient and effective matching algorithms. Results obtained by applying the proposed scheme to a variety of images are presented.
  • Publication
    Experiments in Multirobot Air-Ground Coordination
    (2004-04-26) Chaimowicz, Luiz; Grocholsky, Ben; Keller, James F; Kumar, R. Vijay; Taylor, Camillo J
    This paper addresses the problem of coordinating aerial and ground vehicles in tasks that involve exploration, identification of targets and maintaining a connected communication network. We focus on the problem of localizing vehicles in urban environments where GPS signals are often unreliable or unavailable. We first describe our multi-robot tesbed and control software used to coordinate ground and aerial vehicles. We present the results of experiments in air-ground localization analyzing three complementary approaches to determining the positions of vehicles on the ground. We show that the coordination of aerial vehicles with ground vehicles is necessary to get accurate estimates of the state of the system.
  • Publication
    Human Robot Interaction and Usability Studies for a Smart Wheelchair
    (2003-10-27) Parikh, Sarangi P.; Rao, Rahul; Kumar, R. Vijay; Jung, Sang-Hack; Taylor, Camillo J; Ostrowski, James P.
    We build on previous work [12], [14] on the development of a computer controlled wheelchair equipped with a suite of sensors and a novel interface for human-robot interaction. In this paper, we present experimental results and usability studies for the wheelchair. The architecture for human-robot interaction is hierarchical, with the lowest level corresponding to trajectory control, the intermediate level being behavioral and the highest level involving the composition of behaviors and navigation. Our experimental results illustrate the benefits of a shared-control paradigm where the human operator selects the appropriate hehavior(s) or goals while the software is responsible for executing behaviors and generating safe trajectories. Experiments with human users highlight advantages of augmentation in wheelchairs.