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 (20-Jul-94)
Message-ID: <1994Jul31.080641.27786@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 08:06:41 GMT
Lines: 131

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 (20-Jul-1994)

The final field test of Dante continued today, after a relatively
uneventful night.  Four members of the deployment team camped out at
the test site to protect the robot and support equipment from damage
while in its deployed configuration in the gravel pit.  At about 1:00
am, a local teenager riding an all-terrain vehicle through the gravel
pit nearly ran into the extended tether, but was (fortunately)
intercepted just a few feet short of impacting the cable.  After his
departure, the rest of the night passed without incident.

In the morning the test resumed.  From its position at the bottom of
the gravel pit, Dante ascended the slope back to the shipping pallet,
a distance of 80 meters, in a little over two hours.  At noon, the
local press was invited to the test site for a photo opportunity of
Dante completing the field test activity.

Note: up until this point in the field test, we had cordoned off the
test area and asked that no visitors or press visit the site.  This
was due to a safety concern associated with the laser scanner and
other communications gear used by the robot during nominal operations.
The laser scanner, which was used over 25 times during the field test,
is not eye-safe within 100 feet.  The satellite communication dish,
which is elevated only three feet off the ground, was radiating
constantly during the field test.  In addition, the wireless video
link between Dante and the rim camera uses a relatively high power
microwave transmission which could be hazardous.  This combination of
hazards forced us to define a 400-foot wide exclusion area, which
basically encompassed most of the gravel pit.  The local press was
very considerate, and respected the request to avoid the area during
the test.  In return, we granted them full access to the area and the
deployment team once the laser and microwave had been turned off (we
still kept folks away from the satellite dish, as it was constantly
active to maintain communications with the command center).

During the test, Dante walked about 200 meters, or about half of the
total distance expected for the traverse inside the crater of
Mt. Spurr.  The test traverse included 30-degree slopes (about half
the slope angle expected in Mt.  Spurr, although Dante has been tested
on slopes up to 90 degrees) with uneven and vegitation-obscured
terrain, crossing four different slope angle transitions, and
exploring the bottom of the pit.  The laser scanner resolution was
good enough to resolve erosion marks and tire tracks in the dried mud
at the bottom of the gravel pit.  The dead reckoning software has been
fine-tuned to the point that the scanner and footfall force data
correspond exactly in VEVI.

Each critical element required for the volcano deployment was tested
and validated during the test, including the GCI satellite link, the
ACTS satellite link, and the remote power station (it was impossible
to test these components of the full system prior to arrival in
Anchorage, due to limited or nonexistent access to the components from
Pittsburgh).  Of major significance, the video link from Anchorage to
Ames Research Center and the National Air & Space Museum was finally
established and stabilized.  After sending a complete software
configuration from the rim station video codec to the remote codec
sites, the problem experienced during the past week with the remote
sites not receiving the digitized video was tracked down.  The short
version of the story is that the codecs must be initialized on the
communications network in a specific sequence to enable connection to
the transmitting codec in the rim station.  If the initialization is
performed in the right sequence, then the remote sites are able to
operate receive only for as long as the communications channel remains
open.  The video link is now up and running, although its' stability
is based on the quality fo the communications network via the
satellite connections from Anchorage to the two remote sites (via ACTS
and GCI).

As a result, both ARC and NASM were able to receive video of the
entire second day of the field test (special recognition goes to Terry
Fong for heading up the effort to isolate and correct the problem!).
In addition to just observing the video and computer graphics
information, ARC was also able to remotely operate the rim camera
through the UI2D interface.  The combination of the digitized video
imagery from the cameras onboard Dante and the virtual reality
interface provided by VEVI provided sufficient visual and contextual
information that the controllers at NASM expressed the opinion that
they truly understood the environment being explored by Dante,
including the form, content and texture of the gravel pit and the
relationship of the robot to its surroundings, even though they were
almost 4000 miles away.  Even before entering the volcano, this is a
very significant statement to support of the ability of remote
telepresence- and virtual reality-supporting robotic explorers (such
as Dante) to provide sufficient information to permit understanding of
remote environments which are either too distant or too dangerous for
direct human observation and exploration.

Very late in the day, as the field test tear down was beginning, we
received an opportunity to use available space on a Chugach Power
Association barge to move Dante to the Beluga airstrip on the other
side of Cook Inlet (approximately 60 miles from Anchorage, and only 30
miles from Mt. Spurr).  After a panic-pace tear down, completed in
only 45 minutes, Dante was trucked to the Anchorage docks and placed
on the barge for the overnight sail to Beluga, while the remainder of
the support equipment was returned to the staging area for repacking
and preparation for the volcano deployment, which could happen as
early as Friday evening (weather permitting).

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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
