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 (19-Jul-94)
Message-ID: <1994Jul31.080351.27649@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 08:03:51 GMT
Lines: 113

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 (19-Jul-1994)

The majority of today's activities focused on moving Dante and the rim support 
equipment from the staging area at UAA to the field test site, located in a 
gravel pit in south Anchorage, and then initiating the field test.

This effort consisted of packing all the equipment which will
eventually be deployed on the rim of the Mt. Spurr crater onto the
shipping pallets, lifting the pallets onto a flatbed truck and
trucking to the test site.  Once there, the system (consisting of
Dante, the power generator, the rim station computers, and the
satellite communications station) were placed in relative locations
approximating the Mt. Spurr deployment.  From there, a full "dress
rehearsal" of the deployment was conducted, with the assigned members
of the crater rim team conducting the test site deployment using the
same procedures and equipment that will be flown to the volcano.  The
other members of the mechanism team monitored the deployment test,
taking note of possible efficiency improvements, tool reassignments,
and procedural changes which will be implemented for the trip to the
volcano.

The time required for the four-member deployment team to bring Dante
to the point where it was ready for the controllers located at the
command center to take control of the robot was one hour and 45
minutes.  This involved removing all hold-down straps, placing and
connecting all cabling between the various stations, assembling and
aiming the satellite dish, placing the tether anchor, checking and
starting the power generator, powering and verifying the rim station
computers, testing the satellite modem, installing the rim pan and
tilt camera, raising Dante's sensor mast, and installing the laser
scanner, pan & tilt camera unit and garbage-can-lid "rain hat" on the
mast.  From there, the controllers required approximately one hour to
conduct the software checks and validate the status of the robot
before it was able to start walking off the shipping pallet and into
the gravel pit.  Overall, the test deployment went very smoothly, and
much faster than originally expected.  While the actual deployment
time on the volcano crater will be longer (due to the increased
distances between the stations and the need to fill 60 sandbags for
ballast to hold down the satellite dish), the team felt comfortable
with the deployment procedures and the likely time lines.

The controllers in the command center then used the next several hours
to test all the systems on board the robot and exercise the hardware.
During the course of this first part of the dry run, Dante walked 80
meters from the deployment site down a 30-degree slope to the bottom
of the gravel pit.  While walking, the laser scanner was activated 13
times to obtain high resolution terrain maps of the area surrounding
the robot.  In several cases, the resolution of the scans was
sufficient to resolve small shrubs in the vicinity of the robot.  They
were also used to overcome concerns by the controllers about some
terrain features which appeared to be severe slope hazards when just
looking at the stereo video, but the laser scans revealed that the
slope angle was being exaggerated by the video and descending the
slope would really be well within the performance capabilities of
Dante.  Performance information on Dante was also recorded, including
all actuator positions and force sensor readings for each movement of
the robot, along with recordings of the video images received from the
seven onboard cameras and the rim camera.

All the information from the UI2D "dashboard" and the VEVI virtual
reality display was echoed to the remote workstations at Ames Research
Center and the National Air and Space Museum, where they were able to
monitor the operations in the gravel pit in real time.  However,this
monitoring was limited to the computer displays only, as the video
link to ARC and NASM is still incomplete and proving to be
problematic.  It has been determined that the video codecs supplied by
VTEL, located at ARC and NASM, will not operate in receive-only mode,
and will thus be unable to receive the video signal from Anchorage
(this is despite assurances from VTEL three weeks ago that the codecs
would be able to operate in this manner with no problem).  The
communications controllers at the command center and ARC worked
several hours with the configurations of the codecs in an attempt to
circumvent the limitations of the devices.  For a brief period (about
20 minutes) they were able to pass video to ARC, however the
configuration of the codecs was not stable and the video link could
not be maintained or recovered.  The team is investigating options to
either prepare entirely new software configuration loads for the
remote codecs, or to have the codecs replaced with different models as
quickly as they can be obtained.

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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
