HDTenEightyP/NetNews huggingface dataset:
From: gerry@cmu.edu (Gerry Roston)
Subject: Re: Dead reckoning
Date: Sun, 12 Apr 92 00:08:12 GMT
Organization: Field Robotics Center, CMU
Reply-To: gerry@cmu.edu (Gerry Roston)
Distribution: comp.robotics

In article <1992Apr10.164126.25875@elroy.jpl.nasa.gov> gat@forsight.jpl.nasa.gov (Erann Gat) writes:
   In article <GERRY.92Apr10110253@onion.cmu.edu> gerry@cmu.edu (Gerry Roston) writes:
   >  I suspect that when
   >we repeat these tests as the Ambler walks around outdors, that the
   >error will be less.  [Why?  Because I suspect that the error in my
   >ground truth measurements were high due to the confined conditions of
   >the building in which the earlier tests were done.]

   Why whould confined conditions increase ded reckoning errors?  Is the 
   robot bumping into the walls?

Let me explain the measuring technique used:  We mounted a number of
retro-reflectors on the Ambler.  These devices are nifty little prism
do-hickeys that take a beam of light within some range and reflect it
back to its origin.  These devices are used by surveying instruments
and the intention is that the angle of incidence is small (although
they have an included angle of 45 degrees).  Anyway, by measuring the
position of three of these (rigidly mounted to the Ambler), we can
calculate the position of any point on the body.

The device used to measure these points was a surveying instrument, a
device typically used to measure distances of up to miles, not less
than 15 meters.  So, within the building, the Ambler was too close to
properly focus the sighting telescope, the angle of incidence became
quite large as the Ambler approached the measuring station, the
position of the measuring station was such that is was akward to use,
etc.  While I can sympathoze with Erann in that my original statement
runs against ordinary intuition about measuring, because of the
circumstances in this instance, I stand by my earlier statement.

--
Gerry Roston (gerry@cmu.edu)    | The most foolish mistake we could possibly
Field Robotics Center,          | make would be to allow the subjected people
Carnegie Mellon University      | to carry arms, history shows that all
Pittsburgh, PA, 15213           | conquerors who have allowed their subjected
(412) 268-3856                  | peoples to carry arms have prepared their own
                                | fall. Adolph Hitler
The opinions expressed are mine | 
and do not reflect the official | 
position of CMU, FRC, RedZone,  | 
or any other organization.      |
Newsgroups: comp.robotics
Subject: XY table with stepping motors wanted 
From: cohen@cmu.unige.ch
Date: 7 Apr 92 17:59:39 +0200
Organization: University of Geneva, Switzerland

We are desesperatly looking for a XY mouvement table with stepping motors,
eventually already featuring a PC-compatible interface (or RS-232/parallel),
covering an averaged 15x20cm ( 6x8 inches) surface.

Many thanks for any help !

E Cohen-Laroque
University of Geneva, Switzerland
COHEN@CMU.UNIGE.CH
From: pricejoh@CS.ColoState.EDU (john russel price)
Newsgroups: comp.robotics
Subject: Comp interface A-D D-A cards schematics
Date: 8 Apr 92 19:01:12 GMT
Organization: Colorado State University Computer Science, Industrial Technology


  Hello everyone,
        This may be a long shot request but what the heck. I recently built
   a "Universal Computer Interface" from a book by Bruce Chubb, I thought some
   of you might have seen this and posibly built one too. In the book an  
   appendix supplied copys of the necessary circuit boards for people with the
   resource to produce themselves. This appendix didn't include the A to D
   or D to A card layouts, although it gives a source if you would like to buy
   them. I was wondering if anyone had the circuit board layouts that would
   be willing to part with a copy. This would greatly be appreciated if someone
   has any info please e-mail.

                                        Thanks 
                                               John
-- 
John Price    email: pricejoh@handel.CS.Colostate.Edu
Newsgroups: comp.robotics
From: smith@sctc.com (Rick Smith)
Subject: Re: Dead reckoning
Organization: SCTC
Distribution: comp.robotics
Date: Fri, 10 Apr 1992 14:24:55 GMT

hollombe@polymath.tti.com (The Polymath) writes:

> The term usually refers to navigation by reference to known
>landmarks, ...

Well, yes, you start from a known landmark, but the "ded" for "deduced"
refers to the fact that when you need to know your location you don't
have any landmarks available. You *start* from a known landmark but
then you deduce your position based on direction and amount of motion.

My original statement was that you can't just rely on ded reckoning
("dead" reckoning). You need some kind of position sensor to close
the position control loop or the errors will accumulate.

I interpreted the original question as a search for low cost position
sensing, and I don't think that ded reconing is good enough for "low
cost" position sensing except on toys.  If you have to go to esoteric
drive systems or inertial nav, then I don't see ded reconing as a low
cost alternative to sensing external features.

You can't really ever get away from "some" ded reconing; that's
essentially what a moving device is doing as it moves between
position/feature sensor readings.

Rick.
smith@sctc.com         arden hills, minnesota


Newsgroups: comp.robotics
From: jak@cs.brown.edu (Jak Kirman)
Subject: De[a]d reckoning and robot navigation
Reply-To: jak@cs.brown.edu
Organization: Dept. of Computer Science, Brown University
Date: Sun, 12 Apr 1992 03:03:13 GMT

In article <34409@ttidca.TTI.COM> hollombe@polymath.tti.com (The Polymath) writes:
>   Just a nit:  The correct spelling is "ded reckoning". "Ded" is short for
>   "deductive." The term usually refers to navigation by reference to known
>   landmarks, so, yes, it's still a feasible option, but I don't think that
>   was the question you were asking.

Well, I love nits, and this one has aroused my curiosity.  My OED gives:

   Dead reckoning. Naut. [DEAD a. V.]  The estimation of a ship's
   position from the distance run by the log and the courses steered by
   the compass, with corrections for current, leeway, etc., but without
   astronomical observations.

There follow a number of quotations using the term, dating back to 1613.
[DEAD a. V.] specifies that DEAD is being used as an adjective in sense
V, which is:

   Unrelieved, unbroken; absolute; complete; utmost.

What sources do you have that give "ded reckoning"?

According to the definition above, navigation using landmarks is not
dead reckoning.  I think the common usage agrees with the definition
above. 

Finally, to give my opinion on the original question, if you only use it
for short periods of time, on surfaces that are not too slippery, and
your robot's wheels don't get out of alignment much, and the surfaces
are level, and you don't need measurements that are too accurate, it
works wonderfully.

We have a couple of Real World Interface 12 inch bases.  We use them in
an office environment -- carpets on which the wheels don't slip too
much, and fairly level floors.  The principal problem is alignment: the
robot has three wheels, and over time they get further and further from
being parallel.  So when the robot thinks it is going straight, it is in
fact describing a broad arc.  Such angular errors quickly produce large
positional inaccuracies.  There is also something of a problem with
uneven floors: if there is a bump positioned such that one side of the
robot goes over it but the other one does not, then the robot ends up
turned through a small amount, without realizing it.  There are a few
places where this has caused problems for us.

Basically, we rely on dead reckoning only for the coarsest of
measurements: we use a simple PID controller to drive the robot down the
middle of a corridor to a junction, and dead reckoning to see whether we
somehow missed a junction because a door was closed or people were
blocking off a passage, etc.  When it is a matter of knowing whether you
have traveled 4 meters since the last junction or 5, dead reckoning is
fine for the most part.

                         Jak Kirman                        jak@cs.brown.edu
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Any clod can have the facts, but having opinions is an art.
                                   --Charles McCabe, San Francisco Chronicle
Newsgroups: comp.robotics
From: gat@forsight.jpl.nasa.gov (Erann Gat)
Subject: Re: Dead reckoning
Organization: Jet Propulsion Laboratory
Distribution: comp.robotics
Date: Fri, 10 Apr 1992 16:41:26 GMT

In article <GERRY.92Apr10110253@onion.cmu.edu> gerry@cmu.edu (Gerry Roston) writes:
>  I suspect that when
>we repeat these tests as the Ambler walks around outdors, that the
>error will be less.  [Why?  Because I suspect that the error in my
>ground truth measurements were high due to the confined conditions of
>the building in which the earlier tests were done.]

Why whould confined conditions increase ded reckoning errors?  Is the 
robot bumping into the walls?

Erann Gat
gat@robotics.jpl.nasa.gov
From: lasky@eecs.ucdavis.edu (Ty A. Lasky)
Newsgroups: comp.robotics
Subject: Kinematics for GMF 420-F
Date: 7 Apr 92 21:54:03 GMT
Organization: UC Davis  Robotics Research Lab
Originator: lasky@cedar.eecs.ucdavis.edu

Does anyone have the kinematic equations for the GMF 420-F robot. I
need the forward kinematics, and, if available, the inverse
kinematics. I would like the equations themselves, and if you have any
code, that would be nice also. The 420-F is the floor-mounted model,
but the kinematics for any of the GMF robots that are similar would
also be useful.

Please contact me by e-mail if you have any information on this.

Thanks,

Ty A. Lasky
UC Davis Robotics Research Lab
lasky@cedar.eecs.ucdavis.edu
Xref: sparky comp.robotics:938 sci.electronics:8073
From: jjwwjj@mixcom.com (Robotic Systems)
Newsgroups: comp.robotics,sci.electronics
Subject: ISAAC ASIMOV IS DEAD
Date: 6 Apr 92 15:45:47 GMT
Article-I.D.: mixcom.1992Apr06.154547.16998
Followup-To: poster
Organization: Milwaukee Internet Xchange BBS, Milwaukee, WI U.S.A.

I just read that Isaac Asimov died today. This is a sad day for robotics.

Isaac wrote many books about robotics, including the famous "I, ROBOT."

This book contained the three laws of robotics.

Can anyone confirm this report?



-- 
===============================================================================
ROBOTIC SYSTEMS, INC.                                           CLINT LASKOWSKI
P. O. Box 552                                                    (414) 778-7675
Cudahy, Wisconsin  53110-0552                                 robots@mixcom.com
===============================================================================
From: nivek@frc.ri.cmu.edu (Kevin Dowling)
Newsgroups: comp.robotics
Subject: Dead reckoning
Date: 9 Apr 92 22:05:42 GMT
Article-I.D.: scythe.NIVEK.92Apr9170542
Reply-To: nivek@ri.cmu.edu (Kevin Dowling)
Distribution: comp.robotics
Organization: Field Robotics Center, CMU


We've used several INS systems in our work. They do tend to be the
expensive military systems (we don`t pay for them!)
but more recently available inexpensive heading gyros can
provide fairly accurate heading information.

Skid-steer devices like that mentioned are pretty bad for open-loop
dead-reckoning. For small moves in the direction of the tracks
they can be pretty accurate but additional sensing with INS`s
or heading sensors you can do ok. If you pickup up on external
features once in a while you can recalibrate your drift errors.

Dead-reckoning need not be very bad though. With accurate all-wheel
systems like synchronous or independent steer you can get 1-2% 
accuracies in building or warehouse environments. With some
roller wheels (Mecanum or La) you can do even better because
contact is nearly pure rolling and not skidding.

Some of this navigation technology is being driven by truck and
automotive needs and several car companies have invested resources
into heading devices.


			nivek
--

aka: Kevin Dowling			Carnegie Mellon University
tel: (412) 268-8830			The Robotics Institute
adr: nivek@rover.ri.cmu.edu		Pittsburgh, PA 15213
From: levas@romulus.rutgers.edu (robert levas)
Newsgroups: comp.robotics
Subject: HERO2000 disk drive needed!
Date: 8 Apr 92 00:20:06 GMT
Organization: Rutgers Univ., New Brunswick, N.J.

I have a Hero2000 and I am looking to buy a disk drive for it.  If you
know of anyone that will sell one to me, please let me know.

Robert Levas                            levas@remus.rutgers.edu
RPO 430                                 (908) 878-2058
PO BOX 5063
New Brunswick, NJ 08903
-- 



=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
 _  _  _                           |school:                 |aka:             
|_|| ||_)_ Robert Levas            |(908)878-2058           |"super stud comp.
| \|_||_)  levas@remus.rutgers.edu |RPO 0430 PO BOX 5063    |   sci. major"    
                                   |New Brunsiwck, NJ 08903 | -morale@rpi.edu
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Newsgroups: comp.robotics
From: kfieldin@gollum (Kenneth H. Fielding)
Subject: wanted: Computer Vision by Ballard and Brown
Date: Wed, 08 Apr 92 14:00:57 GMT
Organization: Air Force Institute of Technology


I am looking for a used copy of the book
Computer Vision by Ballard and Brown

If you have a copy to sell please contact
me at

kfieldin@galaxy.afit.af.mil
or
kfieldin@frodo.afit.af.mil
From: krn@waikato.ac.nz
Newsgroups: comp.robotics
Subject: robot controller
Date: 13 Apr 92 11:57:23 +1200
Organization: University of Waikato, Hamilton, New Zealand


	I am currently involoved in a project using transputers to
control a simple robot arm. The project involves designing an building a
control system which uses a a transputer per motor on the robot (the motors
are driven using pulse width modulation). I have already designed and partly
constructed a circuit to control one motor and once this is has been tested
I will expand the system to control the entire robot (I am using the IMST212
as it is cheap for prototyping).
	I know that there are people out there who will say why are you
using transputers instead of a micro-controller but this is firstly a
project with transputers and then a project in robotics.
	What I am interested in knowing is if there is anyone else out
there who is trying/has tried a similar project. All of the previously
documented research I have seen have used transputers to only do position
calculations etc, and have not used them to actually provide input to motors,
process interrupts etc.
	(This is for my fourth year project at University).

				Kevin Niederberger.

Newsgroups: comp.robotics
From: tilden@casbah.acns.nwu.edu (Robert Tilden)
Subject: Re: Questions about Tracked Robot Vehicles
Keywords: robot accuracy
Organization: Northwestern University, Evanston, Illinois
Date: Mon, 13 Apr 1992 15:48:16 GMT

Hi,
	I've been following the thread on robot navigation with some
interest. I'll be the first to admit that I know very little about the
subject, but I was under the impression that 'idler' wheels were fairly
accurate measures of location. For example, a 'tricycle' type robot
platform with one drive/steering wheel and two idler wheels can, with an
encoder on each of the idler wheels, keep fairly close track of its
location over a range of maneuvers and surfaces. Is this true? What are
situations in which this method fails?

-Bob
From: r0s7997@zeus.tamu.edu (SREEKANTAPPA, RAVISHANKAR)
Newsgroups: comp.robotics
Subject: Issac Asimov dead
Date: 6 Apr 92 18:11:00 GMT
Organization: Texas A&M University, Academic Computing Services
News-Software: VAX/VMS VNEWS 1.41

Yes Asimov is dead, and I heard the news on CNN Headline News at about 12 noon
CST. I beleive this is a great loss to the robotic community. Hopefully this
will motivate the robotic community to implement all the fiction he had 
conceived into reality and offer tributes to this great man


Newsgroups: comp.robotics,sci.electronics
From: andnick@milton.u.washington.edu (Nick Anderson)
Subject: stepper motor questions
Reply-To: andnick@u.washington.edu
Organization: University of Washington, Seattle
Date: Sat, 11 Apr 1992 01:47:40 GMT


A small group of CSc students are busy putting together some basic robot 
pieces which will hopefully merge into a moving robot by mid May.

However, there are a few things that are causeing us a little confusion,
namely where and how to interface gears to our stepper motors. Does 
anyone know of any low tech method of either hooking up a differential or
locating some semi-assembled gears (from the smooth, frictionless shaft 
all the way to the nice traction giving tires) for students on a extremely
limited budget ?
 
thanks in advance.
.
BTW: I would like to recommend a book that has been a great help as of late
 called >The Robot Builders Bonanza: 99 inexpensive robotics projects<
by Gordon Mccomb, Tab books, 1987. Extremly well written.

andnick@milton.u.washington.edu

Newsgroups: comp.robotics
From: nagle@netcom.com (John Nagle)
Subject: Re: XY table with stepping motors wanted 
Date: Wed, 08 Apr 92 04:03:02 GMT
Organization: Netcom - Online Communication Services  (408 241-9760 guest) 

cohen@cmu.unige.ch writes:

>We are desesperatly looking for a XY mouvement table with stepping motors,
>eventually already featuring a PC-compatible interface (or RS-232/parallel),
>covering an averaged 15x20cm ( 6x8 inches) surface.

       Try Silicon Valley Surplus, 1273 Industrial Parkway West,
Building 460, Hayward, CA 94544-7025 USA. [Telephone 510-582-6602].
They have a low-cost XY positioner with a travel of 5 inches by 6 inches
for $59 US.  This uses gearmotors and linear pots, and requires
external drive circuitry (not supplied).  They also sell stepping motor
sets that can be driven from a PC's parallel port, for under $50, so
you might be able to substitute stepping motors.  

       Other sources of XY tables are available, but they usually cost
more.  You need to specify how heavy a load is to be carried and how
much precision is required.  XY tables for a milling machine are very
different from XY tables for a visual inspection system.

					John Nagle
Newsgroups: comp.robotics
From: zha@iitb.fhg.de (Zhang)
Subject: E-Mail Address of Dr. Bavarian or Dr. Mortezale
Organization: Institut fuer Informations- und Datenverarbeitung
Date: Mon, 13 Apr 1992 09:25:55 GMT

Hi, friends,

I am looking the e-mail address of Dr. Behnam Bavarian oder 
Dr. Faramarz Mortezale. I think they both are with the Department
Eleectrical Engineering, University of Califonia at Irvine. 
I want to contact them because of one of their articles. 

Who know them or the e-mail address of them, please send me a 
mail under the following address:

zha@iitb.fhg.de

Thanks in advance,

Jinyou Zhang

======================================================================
--
Jinyou Zhang                                       email: zha@iitb.fhg.de 
Fraunhofer-Institut fuer Informations- und         phone: (0721) 6091-438
           Datenverarbeitung - IITB                fax:   (0721) 6091-413
Fraunhoferstrasse 1,  D-7500 Karlsruhe 1, Germany
Newsgroups: comp.robotics
From: alan@pluto.jpl.nasa.gov (Alan Quan)
Subject: SpaceOps 92 Demonstrations
Reply-To: alan@pluto.JPL.NASA.GOV
Organization: Jet Propulsion Laboratory, Pasadena CA
Date: Fri, 10 Apr 1992 20:57:12 GMT


*************************************************************

    Call for Participation - SpaceOps 1992 Demonstrations

    		    November 17-20, 1992
    	         Jet Propulsion Laboratory
    	    	    Pasadena, CA, U.S.A.

*************************************************************



As space missions have become increasingly diverse, complex, and
expensive, mission operations and ground systems have emerged as
critical factors in the success of those missions.  Future success in
space will depend upon the people and systems that control spacecraft
from the ground.

SpaceOps 92, the Second International Symposium on Ground Data Systems
for Space Mission Operations, will provide a unique opportunity for the
people who perform space mission activities to exchange information,
discoveries, and plans for the future.  SpaceOps 92 will focus on a
number of key activities:

	o  Mission control and data management
	o  Space mission navigation
	o  Space vehicle health and trend analysis
	o  Data acquisition systems
	o  Science planning and data analysis
	o  Operations system architectures and concepts
	o  Automation and emerging technologies
	o  Mission and science activity planning, programming, and sequencing


DEMONSTRATIONS
--------------
In addition to formal papers, SpaceOps 92 will feature demonstrations.
Demonstrations show how an organization has approached a particular
problem related to the symposium theme.  Demonstrations may take the
form of "show and tell" at workstations or consoles, videotapes,
multimedia presentations, or live demonstrations.  Demonstrations
should showcase recently developed applications, not commercial tools.

If you would like to perform a demonstration of your space mission
operations related software or hardware, please submit a 250-word
description of the proposed demonstration via EMAIL or FAX,
by April 17, 1992 to:

    Ursula Schwuttke
    Jet Propulsion Laboratory
    phone:  (818) 354-0914

    email:  ursula@nereid.jpl.nasa.gov
    FAX:  (818) 393-4089

Please do not reply on USENET.  Please include your phone number, FAX
number (if available), and email address.
Newsgroups: comp.robotics
From: kfieldin@bilbo (Kenneth H. Fielding)
Subject: wanted:Computer Vision by Ballard and Brown
Date: Tue, 07 Apr 92 13:01:18 GMT
Organization: Air Force Institute of Technology


I am looking for a used copy of Computer Vision
by Ballard and Brown

If you have a copy to sell please contact me
at 

kfieldin@galaxy.afit.af.mil
From: smith@sctc.com (Rick Smith)
Newsgroups: comp.robotics
Subject: Re: Questions about Tracked Robot Vehicles
Date: 9 Apr 92 20:16:52 GMT
Article-I.D.: sctc.1992Apr9.201652.16189
Organization: SCTC

Re: "dead" reckoning and inertial navigation.

The original post was referring to dead reckoning based on measurements
of how much a robot's wheels spun. This made me think more of counting
knots trailing out the back of a sailing ship than of intertial nav.
So it sounds like my oceangoing analogy is out of date.

On the other hand, isn't inertial nav the wrong sort of scale for
controlling the movement of a small vehicle? Even if you have a map
of the environment, how close do you dare approach an obstacle without
risking a collision?

Rick.
smith@sctc.com       arden hills, minnesota
Newsgroups: comp.robotics
From: zha@iitb.fhg.de (Zhang)
Subject: E-Mail Address Wanted
Organization: Institut fuer Informations- und Datenverarbeitung
Date: Thu, 9 Apr 1992 14:18:34 GMT

Hi, friends,

I am looking for the e-mail address of Dr. Bavarian at 
Department of Electrical Engineering, Uni. of CA at Irvine.

Thanks in advance.

Jinyou Zhang

========================================================================= 
--
Jinyou Zhang                                       email: zha@iitb.fhg.de 
Fraunhofer-Institut fuer Informations- und         phone: (0721) 6091-438
           Datenverarbeitung - IITB                fax:   (0721) 6091-413
Fraunhoferstrasse 1,  D-7500 Karlsruhe 1, Germany