Author name cluster

Mark W. Maimone

Possible papers associated with this exact author name in Arrow. This page groups case-insensitive exact name matches and is not a full identity disambiguation profile.

5 papers

1 author row

ICRA Conference 2001 Conference Paper

Stereo Ego-motion Improvements for Robust Rover Navigation

Clark F. Olson
Larry H. Matthies
Marcel Schoppers
Mark W. Maimone

Robust navigation for mobile robots over long distances requires an accurate method for tracking the robot position in the environment. Techniques for position estimation by determining the camera ego-motion from monocular or stereo sequences have been previously described. However, long-distance navigation requires a very high level of robustness and a very low rate of error growth. In this paper, we describe a methodology for long-distance rover navigation that meets these goals using robust estimation. We show that a system based on only camera ego-motion estimates will accumulate errors with super-linear growth in the distance travelled, owing to increasing orientation errors. When an absolute orientation sensor is incorporated, the error growth can be reduced to a linear function of the distance travelled. We tested these techniques using both extensive simulation and hundreds of real rover images and achieved a low, linear rate of error growth.

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ICRA Conference 2000 Conference Paper

Rover Maneuvering for Autonomous Vision-Based Dexterous Manipulation

Issa A. D. Nesnas
Mark W. Maimone
Hari Das Nayar

Manipulators mounted on-board rovers have limited dexterity due to power and weight constraints imposed by rover designs. However, to perform science operations, it is necessary to be able to position and orient these manipulators on science targets in order to carry out in-situ measurements. This article describes how we enhance manipulator dexterity using the rover mobility system. The lack of omni-directional driving capability and the constraints imposed by the mobility mechanism requires vehicle maneuvering to supplement the manipulators' motions. Target tracking using stereo vision is integrated with rover maneuvering to perform two types of operations: rock sample acquisition for return to earth and instrument placement for in-situ science measurements. We describe the computational architecture, tools, and algorithms that we developed for this task. We have successfully demonstrated these operations on a self-contained Mars Rover prototype, Rocky 7. We have demonstrated grasping a small rock sample from a distance of more than one meter away and placing an instrument on a boulder from a distance of more than five meters away.

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IROS Conference 1998 Conference Paper

A photo-realistic 3-D mapping system for extreme nuclear environments: Chernobyl

Mark W. Maimone
Larry H. Matthies
James Osborn
Eric Rollins
James P. Teza
Scott Thayer

We present a stereoscopic mapping system for use in post-nuclear accident operations by the Pioneer robot. First we discuss a radiation shielded sensor array designed to tolerate extended cumulative dose using 4/spl times/ shielding. Next, we outline procedures to ensure timely, accurate range estimation using trinocular stereo. Finally, we review the implementation of a system for the integration of range information into a 3-D, textured, metrically accurate surface mesh.

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ICRA Conference 1998 Conference Paper

The Atacama Desert Trek: Outcomes

Deepak Bapna
Eric Rollins
John Murphy 0003
Mark W. Maimone
William Whittaker
David Wettergreen

In June and July 1997, Nomad, a planetary-relevant mobile robot, traversed more than 220 kilometers across the barren Atacama Desert in Chile, exploring a landscape analogous to the surfaces of the Moon and Mars. In this unprecedented demonstration, Nomad operated both autonomously and under the control of operators thousands of kilometers away, addressing issues of robot configuration, communication, position estimation, and navigation in rugged, natural terrain. The field experiment also served to test technologies for remote geological investigation, paving the way for new exploration strategies on Earth and beyond. Finally, by combining safeguarded teleoperation with panoramic visualization and a novel user interface, the Atacama Desert Trek provided the general public a compelling interactive experience an opportunity to remotely drive an exploratory robot. Nomad's performance in the Atacama Desert Trek set new benchmark in high performance robotics operations relevant to terrestrial and planetary exploration. This paper presents an overview of the experiment, describes technologies key to Nomad's success, and discusses outcomes and implications.

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IROS Conference 1995 Conference Paper

Modeling foreshortening in stereo vision using local spatial frequency

Mark W. Maimone
Steven A. Shafer

Many aspects of the real world continue to plague stereo matching systems. One of these is perspective foreshortening, an effect that occurs when a surface is viewed at a sharp angle. Because each stereo camera has a slightly different view, the image of the surface is more compressed and occupies a smaller area in one view. These effects cause problems because most stereo methods compare similarly sized regions (using the same-sized windows in both images), tacitly assuming that objects occupy the same extents in both images. Clearly this condition is violated by perspective foreshortening. We show how to overcome this problem using a local spatial frequency representation. A simple geometric analysis leads to an elegant solution in the frequency domain which, when applied to a Gabor filter-based stereo system, increases the system's maximum matchable surface angle from 30 degrees to over 75 degrees.

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