Newsgroups: comp.robotics
Path: brunix!cat.cis.Brown.EDU!agate!ames!kronos.arc.nasa.gov!doctor
From: doctor@kronos.arc.nasa.gov (Terry Fong)
Subject: Dante II - Mt. Spurr Expedition Status (15-Jul-94)
Message-ID: <1994Jul31.075735.27299@ptolemy-ethernet.arc.nasa.gov>
Summary: status information on CMU/NASA volcano robot explorer
Keywords: Dante, teleoperations, volcano, Alaska
Sender: usenet@ptolemy-ethernet.arc.nasa.gov (usenet@ptolemy.arc.nasa.gov)
Nntp-Posting-Host: tardis.arc.nasa.gov
Organization: NASA Ames Intelligent Mechanisms Group
Date: Sun, 31 Jul 1994 07:57:35 GMT
Lines: 114

The following is a status update on the Dante II project. Dante II is
an eight-legged robot (developed by the CMU Robotics Institute with
sponsorship from NASA) which is currently descending into the active
crater of Mt. Spurr, an Alaskan volcano 80 miles west of Anchorage,
Alaska. The primary objective of the Dante II project is to develop and
evaluate new techniques and technologies which can be applied to space
and planetary exploration. 

Throughout the Mt. Spurr expedition, Dante II is being remotely
operated from a base station in Anchorage using control station
software developed at CMU and NASA Ames. Live video coverage is
periodically available via NASA Select. Full mission details including
current status, real-time images/video, and technical data is available
via a WorldWideWeb server provided by the NASA Ames Intelligent
Mechanisms Group. This site can be accessed on the Internet using
information browsers such as NCSA Mosaic and the URL:

	http://maas-neotek.arc.nasa.gov/dante

Questions regarding the Dante II project may be addressed to me via email 
(terry@ptolemy.arc.nasa.gov). Reponse time may be slow.

Terry Fong
NASA Ames Research Center

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Daily Report (15-Jul-1994)

Preparation for the final dry-run test continued today, with several
elements of the software, hardware and logistics "punch lists"
completed.

The power generation station which will be located at the rim of the
Mt. Spurr crater was placed in the final deployment configuration and
validated.  During the recon mission to the crater rim yesterday
locations for the power station, rim station and rim cameras were
identified and the sites were marked.  It was found that the power
station would be located approximately 230 feet from the rim station
and rim cameras, which is considerably farther than originally
anticipated, and there was some concern about additional voltage drop
across the longer distance.  New cables were constructed during the
day, and tested with the power station in full deployment
configuration late in the evening.  While the drop is noticeable, it
is within acceptable boundaries and no additional changes to the power
station or cabling configuration were deemed necessary.

Based on discussions with the recon team, a revised design for the
anchor system was developed which is better suited to the deep snow
where the anchor will be placed.  This involved modification to the
initial "deadman" and pallet anchors, which were originally intended
for use in soil or soil-and-rock conditions and not for deep snow.
These modifications involved the addition of large snow flukes mounted
to posts buried six feet deep in the snow to reinforce the deadman and
pallet anchors.  The snow anchors were designed and fabrication was
approximately 70% complete by the end of the day (and special
recognition goes to the University of Alaska - Anchorage for allowing
the use of their facilities for the fabrication of the anchors!).  The
remainder of the fabrication will be completed by noon tomorrow.

Moving on from logistics and support activities to the robot itself,
the terrain maps generated by the Virtual Environment Vehicle
Interface (VEVI - the virtual reality simulation of Dante and the
environment immediately surrounding the robot) have been calibrated
with respect to the actual robot position within the VEVI model.  This
means that the position and orientation of the model of Dante
displayed in the virtual reality interface (and which will be seen on
the remote workstations at Ames Research Center and in the National
Air & Space Museum during the crater descent) more accurately reflect
the real position of the robot in the modeled terrain.  Also, the
terrain information generated by the placement of Dante's feet as it
descends into the crater has been calibrated to match the position of
the terrain information retrieved from the laser scanner and displayed
by VEVI.

Final calibration of Dante's laser scanner was completed, including
recalculation of the software model of the scanner positioning,
validation of the software model of the scanner used by VEVI, and a
final cleaning of the laser optics.  These efforts resulted in
significantly improved accuracy in the data received from the scanner,
and in the terrain maps generated by VEVI from the scanner input.  As
a result, the scanner was able to clearly image obstacles such as
chairs, boxes, cargo pallets and grates in the floor of the staging
area around the robot, and accurately determine their position
relative to the robot.  Each of these elements could easily be
identified in the resulting terrain model displayed by VEVI.

Based on the improved accuracy and quality of the scanner data, the
final activity of the day was to have Dante walk around the UAA
staging area based only on laser scanner information.  In this walking
mode, the robot would take a scan of the area with the laser scanner,
build a terrain model of the environment based only on the laser data,
then based on Dante's interpretation of the constructed terrain model
it would walk forward and place it's legs in areas of minimal
potential obstruction, all without human operator intervention.  This
capability is one of the significant technology demonstration
objectives planned for Dante's activities within the crater of
Mt. Spurr, and achieving the level of scanner data accuracy to allow
this type of independent walking was a major milestone in the
preparation for the deployment to the crater.

Plans for tomorrow include finalizing the software calibration of the
robot and sensors, moving the control station to from the staging area
at UAA to it's final location at the Frontier Building in downtown
Anchorage, remotely operating Dante from the relocated control
station, and validating the satellite and fiber data links from
Anchorage to Ames Research Center.

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-- 
_______________________________________________________________________________
 "Every once in a while declare        Terry Fong <terry@ptolemy.arc.nasa.gov>
  peace. It confuses the hell out      NASA Ames, M/S 269-3, Moffett Field, CA
  of your enemies" -- Rule of Acq. #76      (415) 604-6063, (415) 604-6081 lab
