Author name cluster

Pifu Zhang

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.

3 papers

1 author row

IROS Conference 2005 Conference Paper

A visually guided swimming robot

Gregory Dudek
Michael Jenkin
Chris Prahacs
Andrew Hogue
Junaed Sattar
Philippe Giguère
Andrew German
Hui Liu

We describe recent results obtained with AQUA, a mobile robot capable of swimming, walking and amphibious operation. Designed to rely primarily on visual sensors, the AQUA robot uses vision to navigate underwater using servo-based guidance, and also to obtain high-resolution range scans of its local environment. This paper describes some of the pragmatic and logistic obstacles encountered, and provides an overview of some of the basic capabilities of the vehicle and its associated sensors. Moreover, this paper presents the first ever amphibious transition from walking to swimming.

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IROS Conference 2005 Conference Paper

Vision data registration for robot self-localization in 3D

Pifu Zhang
Evangelos E. Milios
Jason Jianjun Gu

We address the problem of globally consistent estimation of the trajectory of a robot arm moving in three dimensional space based on a sequence of binocular stereo images from a stereo camera mounted on the tip of the arm. Correspondence between 3D points from successive stereo camera positions is established through matching of 2D SIFT features in the images. We compare three different methods for solving this estimation problem, based on three distance measures between 3D points, Euclidean distance, Mahalanobis distance and a distance measure defined by a maximum likelihood formulation. Theoretical analysis and experimental results demonstrate that the maximum likelihood formulation is the most accurate. If the measurement error is guaranteed to be small, then Euclidean distance is the fastest, without significantly compromising accuracy, and therefore it is best for on-line robot navigation.

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IROS Conference 2004 Conference Paper

AQUA: an aquatic walking robot

Christina Georgiades
Andrew German
Andrew Hogue
Hui Liu
Chris Prahacs
Arlene Ripsman
Robert Sim
Luz Abril Torres-Méndez

This paper describes an underwater walking robotic system being developed under the name AQUA, the goals of the AQUA project, the overall hardware and software design, the basic hardware and sensor packages that have been developed, and some initial experiments. The robot is based on the RHex hexapod robot and uses a suite of sensing technologies, primarily based on computer vision and INS, to allow it to navigate and map clear shallow-water environments. The sensor-based navigation and mapping algorithms are based on the use of both artificial floating visual and acoustic landmarks as well as on naturally occurring underwater landmarks and trinocular stereo.

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