Newsgroups: comp.robotics
Path: brunix!news.Brown.EDU!noc.near.net!howland.reston.ans.net!ira.uka.de!rz.uni-karlsruhe.de!stepsun.uni-kl.de!uklirb!bambam.informatik.uni-kl.de!uzimmer
From: Uwe R. Zimmer <uzimmer@informatik.uni-kl.de>
Subject: Autonomous mobile robots (papers available)
Message-ID: <1993Apr28.160951.16618@uklirb.informatik.uni-kl.de>
X-Xxmessage-Id: <A80478E35703C008@bambam.informatik.uni-kl.de>
X-Xxdate: Wed, 28 Apr 93 17:09:39 GMT
Sender: news@uklirb.informatik.uni-kl.de (Unix-News-System)
Nntp-Posting-Host: bambam.informatik.uni-kl.de
Organization: University of Kaiserslautern
X-Useragent: Nuntius v1.1.1d17
Date: Wed, 28 Apr 1993 16:09:51 GMT
Lines: 182


A couple of papers about autonomous mobile robots are now
available via FTP:

------------
--- 1993 ---
------------

SPIN - Learning and Forgetting Surface Classifications
       with Dynamic Neural Networks

Herman Keuchel, Ewald von Puttkamer & Uwe R. Zimmer

This paper refers to the problem of adaptability over an infinite
period of time, regarding dynamic networks. A never ending flow of
examples have to be clustered, based on a distance-measure. The
developed model is based on the self-organizing feature maps of
Kohonen [6], [7] and some adaptations by Fritzke [3]. The problem
of dynamic surface classification is embedded in the SPIN project,
where sub-symbolic abstractions, based on a 3-d scanned environment
is being done.

(Zimmer.learning_surfaces.ps.Z)

------------
--- 1992 ---
------------

ALBATROSS - The Communication Scheme as a Key
            to Fulfil Hard Real-Time Constraints

Ewald von Puttkamer, Christopher Wetzler & Uwe R. Zimmer

Based on experiences from an autonomous mobile robot project called
MOBOT-III, we found hard realtime-constraints for the
operating-system-design. ALBATROSS is "A flexible multi-tasking and
realtime network-operating-system-kernel", not limited to
mobile-robot-projects only, but which might be useful also wherever
you have to guarantee a high reliability of a realtime-system. The
focus in this article is on a communication-scheme fulfilling the 
demanded (hard realtime-) assurances although not implying time-
delays or jitters on the critical information-channels.
The central chapters discuss a locking-free shared buffer management,
without the need for interrupts and a way to arrange the
communication architecture in order to produce minimal protocol-
overhead and short cycle-times. Most of the remaining communication-
capacity (if there is any) is used for redundant transfers,
increasing the reliability of the whole system.
ALBATROSS is actually implemented on a multi-processor VMEbus-system.

(Zimmer.rt_communication.ps.Z)

------------
--- 1991 ---
------------

Accurate Position Estimation for an Autonomous Mobile Robot
   Fusing Shaft Encoder Values and Laser Range Data

Thomas Edlinger, Rainer Trieb and Ewald von Puttkamer

This paper describes the real!time position estimation method
developed for MOBOT!III, an autonomous mobile robot for
indoor!applications. MOBOT!III is designed to operate in an
unknown or partially known environment and uses a laser!radar as
the main sensor for environment perception. For environment
modelling and task execution it is essential to determine the
exact position of the vehicle within the operating environment. A
method is presented, which extracts an invariant property of the
local environment by a statistical interpretation of the raw
sensor data. This feature is stored in a global map and is used
for position verification as long as the vehicle moves within
this local environment or whenever it reenters it.

Keywords
   position estimation, correlation, histogram

(Edlinger.Pos_Estimation.ps.Z)

------------

An Efficient Navigation Strategy for an Autonomous Mobile Robot

Thomas Edlinger, Ewald von Puttkamer and Thomas Strauch

This paper describes the navigation component of MOBOT!III, a
laser!radar based autonomous mobile robot for
indoor!applications. MOBOT!III has no preloaded world!model, but
builds up an internal map, while exploring the environment. Based
on a continuously updated part of the world!model, consisting of
obstacle lines, the navigation module constructs a free space
graph to find a way from the startposition to the desired
destination. A method is presented to find a suboptimal way
without creating the complete graph.

Keywords
navigation, world model

(Edlinger.Eff_Navigation.ps.Z)

------------

Extracting Lines, Circular Segments and Clusters from Radar Pictures
   in Real-Time for an Autonomous Mobile Robot

Thomas Knieriemen, Ewald von Puttkamer, Joerg Roth

Autonomous mobile systems have to convert their sensor data in
real time into meaningful data structures to navigate with their
help through their environment.
Here a way is shown to extract a description of the environment
from a radar picture in real time with help of a curvature
function.
The mobile systems has as its environment a bureau like indoor
environment and obstacles detected by a laser radar are described
as lines, circle segments and clusters as building blocks of
maps.
The line extracting algorithm is compared to other line fitting
algorithms and the time needed measured from a number of
different scenes. The algorithm allows to process laser radar
data with 250 ms/picture.

(Knieriemen.euromicro_91.ps.Z)

------------

ALBATROSS - An Operating-System under hard Realtime-Constraints

Ewald von Puttkamer & Uwe R. Zimmer

Based on the experiences from an autonomous mobile robot project
called MOBOT-III, we found hard realtime-constraints for the
operating-system-design. ALBATROSS is "A flexible multi-tasking and
realtime network-operating-system-kernel". The focus in this article
is on a communication-scheme fulfilling the previous demanded
assurances. The central chapters discuss the shared buffer management
and the way to design the communication architecture. Some further
aspects beside the strict realtime-requirements like the possibilities
to control and watch a running system, are mentioned.

(Zimmer.albatross.ps.Z)

------------------------------------------------------------------

FTP-information (anonymous login):

   University of Kaiserslautern FTP-Server is : ftp.uni-kl.de
   Mode is      : binary
   Directory is : reports_uni-kl/computer_science/mobile_robots/...

   Subdirectory is : 1993/papers
   File name is    : Zimmer.learning_surfaces.ps.Z

   Subdirectory is : 1992/papers
   File name is    : Zimmer.rt_communication.ps.Z

   Subdirectory is : 1991/papers
   File names are  : Edlinger.Pos_Estimation.ps.Z
                     Edlinger.Eff_Navigation.ps.Z
                     Knieriemen.euromicro_91.ps.Z
                     Zimmer.albatross.ps.Z
 
Sorry - no hardcopys available

------------------------------------------------------------------

e-mail addresses of the authors:

   edlinger@informatik.uni-kl.de
   trieb@informatik.uni-kl.de
   puttkam@informatik.uni-kl.de
   wetzler@informatik.uni-kl.de
   zimmer@informatik.uni-kl.de

-----------------------------------------------------
                                                       ----- 
   Uwe R. Zimmer                                              ---
     University of Kaiserslautern - Computer Science Department  |
     Research Group Prof. v. Puttkamer                           |
   6750 Kaiserslautern - Germany                                 |
  -------------------------------------------------------------- |
    P.O.Box:3049 | Phone:+49 631 205 2624 | Fax:+49 631 205 2803 |
