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
    A Bounded Uncertainty Approach to Multi-Robot Localization
    (2003-10-27) Spletzer, John R; Taylor, Camillo J
    We offer a new approach to the multi-robot localization problem. Using an unknown-but-bounded model for sensor error, we are able to define convex polytopes in the configuration space of the robot team that represent the set of configurations consistent with all sensor measurements. Estimates for the uncertainty in various parameters of the team's configuration such as the absolute position of a single robot, or the relative positions of two or more nodes can be obtained by projecting this polytope onto appropriately chosen subspaces of the configuration space. We propose a novel approach to approximating these projections using linear programming techniques. The approach can handle both bearing and range measurements with a computational complexity scaling polynomially in the number of robots. Finally, the workload is readily distributed - requiring only the communication of sensor measurements between robots. We provide simulation results for this approach implemented on a multi-robot team.
  • Publication
    Graph Cuts via l1 Norm Minimization
    (2008-10-01) Bhusnurmath, Arvind; Taylor, Camillo J
    Graph cuts have become an increasingly important tool for solving a number of energy minimization problems in computer vision and other fields. In this paper, the graph cut problem is reformulated as an unconstrained l1 norm minimization that can be solved effectively using interior point methods. This reformulation exposes connections between graph cuts and other related continuous optimization problems. Eventually, the problem is reduced to solving a sequence of sparse linear systems involving the Laplacian of the underlying graph. The proposed procedure exploits the structure of these linear systems in a manner that is easily amenable to parallel implementations. Experimental results obtained by applying the procedure to graphs derived from image processing problems are provided.
  • 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.
  • Publication
    Reconstruction of Linearly Parameterized Models from Single Images with a Camera of Unknown Focal Length
    (2001-07-01) Jelinek, David; Taylor, Camillo J
    This paper deals with the problem of recovering the dimensions of an object and its pose from a single image acquired with a camera of unknown focal length. It is assumed that the object in question can be modeled as a polyhedron where the coordinates of the vertices can be expressed as a linear function of a dimension vector, λ. The reconstruction program takes as input, a set of correspondences between features in the model and features in the image. From this information, the program determines an appropriate projection model for the camera (scaled orthographic or perspective), the dimensions of the object, its pose relative to the camera and, in the case of perspective projection, the focal length of the camera. This paper describes how the reconstruction problem can be framed as an optimization over a compact set with low dimension - no more than four. This optimization problem can be solved efficiently by coupling standard nonlinear optimization techniques with a multistart method which generates multiple starting points for the optimizer by sampling the parameter space uniformly. The result is an efficient, reliable solution system that does not require initial estimates for any of the parameters being estimated.
  • Publication
    Semi-autonomous exploration of multi-floor buildings with a legged robot
    (2015-05-01) Wenger, Garrett; Johnson, Aaron; Taylor, Camilo Jose; Koditschek, Daniel E
    This paper presents preliminary results of a semi-autonomous building exploration behavior using the hexapedal robot RHex. Stairwells are used in virtually all multi-floor buildings, and so in order for a mobile robot to effectively explore, map, clear, monitor, or patrol such buildings it must be able to ascend and descend stairwells. However most conventional mobile robots based on a wheeled platform are unable to traverse stairwells, motivating use of the more mobile legged machine. This semi-autonomous behavior uses a human driver to provide steering input to the robot, as would be the case in, e.g., a tele-operated building exploration mission. The gait selection and transitions between the walking and stair climbing gaits are entirely autonomous. This implementation uses an RGBD camera for stair acquisition, which offers several advantages over a previously documented detector based on a laser range finder, including significantly reduced acquisition time. The sensor package used here also allows for considerable expansion of this behavior. For example, complete automation of the building exploration task driven by a mapping algorithm and higher level planner is presently under development. For more information: Kod*lab
  • Publication
    Solving the Graph Cut Problem via l1 Norm Minimization
    (2007-01-01) Bhusnurmath, Arvind; Taylor, Camillo J
    Graph cuts have become an increasingly important tool for solving a number of energy minimization problems in computer vision and other fields. In this paper, the graph cut problem is reformulated as an unconstrained l1 norm minimization. This l1 norm minimization can then be tackled by solving a sequence of sparse linear systems involving the Laplacian of the underlying graph. The proposed procedure exploits the structure of these linear systems and can be implemented effectively on modern parallel architectures. The paper describes an implementation of the algorithm on a GPU and discusses experimental results obtained by applying the procedure to graphs derived from image processing problems.
  • 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
    ROCI: A Distributed Framework for Multi-Robot Perception and Control
    (2003-10-27) Chaimowicz, Luiz; Cowley, Anthony; Sabella, Vito; Taylor, Camillo J
    This paper presents ROCI, a framework for developing applications for multi-robot teams. In ROCI, each robot is considered a node which contains several modules and may export different types of services and capabilities to other nodes. Each node runs a kernel that mediates the interactions of the robots in a team. This kernel keeps an updated database of all nodes and the functionalities that they export. Multi-robot applications can he built dynamically by connecting modules that may be running on different nodes over the network. As an example, we present an obstacle avoidance task implemented using our framework and also discuss the use of ROCI in a multi-robot scenario.
  • Publication
    Reconstruction of Articulated Objects from Point Correspondences in a Single Uncalibrated Image
    (2000-12-01) Taylor, Camillo J
    This paper investigates the problem of recovering information about the configuration of an articulated object, such as a human figure, from point correspondences in a single image. Unlike previous approaches, the proposed reconstruction method does not assume that the imagery was acquired with a calibrated camera. An analysis is presented which demonstrates that there are a family of solutions to this reconstruction problem parameterized by a single variable. A simple and effective algorithm is proposed for recovering the entire set of solutions by considering the foreshortening of the segments of the model in the image. Results obtained by applying this algorithm to real images are presented.
  • Publication
    Camera Trajectory Estimation using Inertial Sensor Measurements and Structure fom Motion Results
    (2001-12-08) Jung, Sang-Hack; Taylor, Camillo J
    This paper describes an approach to estimating the trajectory of a moving camera based on the measurements acquired with an inertial sensor and estimates obtained by applying a structure from motion algorithm to a small set of keyframes in the video sequence. The problem is formulated as an offline trajectory fitting task rather than an online integration problem. This approach avoids many of the issues usually associated with inertial estimation schemes. One of the main advantages of the proposed technique is that it can be applied in situations where approaches based on feature tracking would have significant difficulties. Results obtained by applying the procedure to extended sequences acquired with both conventional and omnidirectional cameras are presented.